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Sample records for 3c clamped downhole

  1. DEVELOPMENT OF A 400 LEVEL 3C CLAMPED DOWNHOLE SEISMIC RECEIVER ARRAY FOR 3D BOREHOLE SEISMIC IMAGING OF GAS RESERVOIRS

    SciTech Connect

    Bjorn N.P. Paulsson

    2004-05-01

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently frustrated by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. 3D VSP and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver array will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of the rock and the

  2. DEVELOPMENT OF A 400 LEVEL 3C CLAMPED DOWNHOLE SEISMIC RECEIVER ARRAY FOR 3D BOREHOLE SEISMIC IMAGING OF GAS RESERVOIRS

    SciTech Connect

    Bjorn N.P. Paulsson

    2004-05-31

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently frustrated by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. 3D VSP and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver array will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of the rock and the

  3. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    SciTech Connect

    Bjorn N.P. Paulsson

    2005-08-21

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently hampered by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver arrays will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of

  4. DEVELOPMENT OF A 400 LEVEL 3C CLAMPED DOWNHOLE SEISMIC RECEIVER ARRAY FOR 3D BOREHOLE SEISMIC IMAGING OF GAS RESERVOIRS

    SciTech Connect

    Bjorn N.P. Paulsson

    2003-12-01

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently frustrated by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. 3D VSP and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver array will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of the rock and the

  5. DEVELOPMENT OF A 400 LEVEL 3C CLAMPED DOWNHOLE SEISMIC RECEIVER ARRAY FOR 3D BOREHOLE SEISMIC IMAGING OF GAS RESERVOIRS

    SciTech Connect

    Bjorn N.P. Paulsson

    2004-09-30

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently frustrated by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver arrays will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of

  6. DEVELOPMENT OF A 400 LEVEL 3C CLAMPED DOWNHOLE SEISMIC RECEIVER ARRAY FOR 3D BOREHOLE SEISMIC IMAGING OF GAS RESERVOIRS

    SciTech Connect

    Bjorn N.P. Paulsson

    2004-06-30

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently frustrated by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. 3D VSP and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver array will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of the rock and the

  7. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    SciTech Connect

    Bjorn N.P Paulsson

    2006-05-05

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently hampered by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver arrays will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of

  8. DEVELOPMENT OF A 400 LEVEL 3C CLAMPED DOWNHOLE SEISMIC RECEIVER ARRAY FOR 3D BOREHOLE SEISMIC IMAGING OF GAS RESERVOIRS

    SciTech Connect

    Bjorn N.P. Paulsson

    2005-03-31

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently hampered by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver arrays will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of

  9. DEVELOPMENT OF A 400 LEVEL 3C CLAMPED DOWNHOLE SEISMIC RECEIVER ARRAY FOR 3D BOREHOLE SEISMIC IMAGING OF GAS RESERVOIRS

    SciTech Connect

    Bjorn N.P. Paulsson

    2004-12-31

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently frustrated by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver arrays will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of

  10. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    SciTech Connect

    Bjorn N. P. Paulsson

    2005-09-30

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently hampered by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver arrays will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of

  11. DEVELOPMENT OF A 400 LEVEL 3C CLAMPED DOWNHOLE SEISMIC RECEIVER ARRAY FOR 3D BOREHOLE SEISMIC IMAGING OF GAS RESERVOIRS

    SciTech Connect

    Bjorn N.P Paulsson

    2003-09-01

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently frustrated by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. 3D VSP and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver array will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of the rock and the

  12. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    SciTech Connect

    Bjorn N. P. Paulsson

    2006-09-30

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to perform high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology has been hampered by the lack of acquisition technology necessary to record large volumes of high frequency, high signal-to-noise-ratio borehole seismic data. This project took aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array has removed the technical acquisition barrier for recording the data volumes necessary to do high resolution 3D VSP and 3D cross-well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that promise to take the gas industry to the next level in their quest for higher resolution images of deep and complex oil and gas reservoirs. Today only a fraction of the oil or gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of detailed compartmentalization of oil and gas reservoirs. In this project, we developed a 400 level 3C borehole seismic receiver array that allows for economic use of 3D borehole seismic imaging for reservoir characterization and monitoring. This new array has significantly increased the efficiency of recording large data volumes at sufficiently dense spatial sampling to resolve reservoir complexities. The receiver pods have been fabricated and tested to withstand high temperature (200 C/400 F) and high pressure (25,000 psi), so that they can operate in wells up to 7,620 meters (25,000 feet) deep. The receiver array is deployed on standard production or drill tubing. In combination with 3C surface seismic or 3C borehole seismic sources, the 400

  13. Development of a 300°C 3C Fiber Optic Downhole Seismic Receiver Array for Surveying and Monitoring of Geothermal Reservoirs

    SciTech Connect

    Paulsson, Bjorn N.P.

    2016-06-29

    To address the critical site characterization and monitoring needs for Enhance Geothermal Systems (EGS) programs, US Department of Energy (DOE) awarded Paulsson, Inc. in 2011 a contract to design, build and test a high temperature fiber optic based ultra-large bandwidth clamped borehole seismic vector array capable of deploying a large number of 3C sensor pods suitable for deployment into high temperature and high pressure boreholes. Paulsson, Inc. has completed a design or a unique borehole seismic system consisting of a novel drill pipe based deployment system that includes a hydraulic clamping mechanism for the sensor pods, a new sensor pod design and most important – a unique fiber optic seismic vector sensor with technical specifications and capabilities that far exceed the state of the art seismic sensor technologies. These novel technologies were all applied to the new borehole seismic system. In combination these technologies will allow for the deployment of up to 1,000 3C sensor pods in vertical, deviated or horizontal wells. Laboratory tests of the fiber optic seismic vector sensors developed during this project have shown that the new borehole seismic sensor technology is capable of generating outstanding high vector fidelity data with extremely large bandwidth: 0.01 – 6,000 Hz. Field tests have shown that the system can record events at magnitudes much smaller than M-4.0 at frequencies over 2,000 Hz. The sensors have also proved to be about 100 times more sensitive than the regular coil geophones that are used in borehole seismic systems today. The fiber optic seismic sensors have furthermore been qualified to operate at temperatures over 300°C (572°F). The data telemetry fibers used for the seismic vector sensors in the system are also used to simultaneously record Distributed Temperature Sensor (DTS) and Distributed Acoustic Sensor (DAS) data allowing additional value added data to be recorded simultaneously with the seismic vector sensor data.

  14. Advanced downhole periodic seismic generator

    DOEpatents

    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.

  15. Downhole hydraulic seismic generator

    DOEpatents

    Gregory, Danny L.; Hardee, Harry C.; Smallwood, David O.

    1992-01-01

    A downhole hydraulic seismic generator system for transmitting energy wave vibrations into earth strata surrounding a borehole. The system contains an elongated, unitary housing operably connected to a well head aboveground 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 hydraulic oscillator containing a double-actuating piston whose movement is controlled by an electro-servovalve regulating a high pressure hydraulic fluid flow into and out of upper and lower chambers surrounding the piston. The spent hydraulic fluid from the hydraulic oscillator is stored and pumped back into the system to provide high pressure fluid for conducting another run at the same, or a different location within the borehole.

  16. Downhole tool adapted for telemetry

    DOEpatents

    Hall, David R.; Fox, Joe

    2010-12-14

    A cycleable downhole tool such as a Jar, a hydraulic hammer, and a shock absorber adapted for telemetry. This invention applies to other tools where the active components of the tool are displaced when the tool is rotationally or translationally cycled. The invention consists of inductive or contact transmission rings that are connected by an extensible conductor. The extensible conductor permits the transmission of the signal before, after, and during the cycling of the tool. The signal may be continuous or intermittent during cycling. The invention also applies to downhole tools that do not cycle, but in operation are under such stress that an extensible conductor is beneficial. The extensible conductor may also consist of an extensible portion and a fixed portion. The extensible conductor also features clamps that maintain the conductor under stresses greater than that seen by the tool, and seals that are capable of protecting against downhole pressure and contamination.

  17. Downhole tool

    DOEpatents

    Hall, David R.; Muradov, Andrei; Pixton, David S.; Dahlgren, Scott Steven; Briscoe, Michael A.

    2007-03-20

    A double shouldered downhole tool connection comprises box and pin connections having mating threads intermediate mating primary and secondary shoulders. The connection further comprises a secondary shoulder component retained in the box connection intermediate a floating component and the primary shoulders. The secondary shoulder component and the pin connection cooperate to transfer a portion of makeup load to the box connection. The downhole tool may be selected from the group consisting of drill pipe, drill collars, production pipe, and reamers. The floating component may be selected from the group consisting of electronics modules, generators, gyroscopes, power sources, and stators. The secondary shoulder component may comprises an interface to the box connection selected from the group consisting of radial grooves, axial grooves, tapered grooves, radial protrusions, axial protrusions, tapered protrusions, shoulders, and threads.

  18. Subsea downhole optical sensing

    NASA Astrophysics Data System (ADS)

    McStay, D.; Shiach, G.; McAvoy, S.

    2009-07-01

    The potential for subsea downhole optical fibre sensing to optimize hydrocarbon production and hence contribute to enhanced oil recovery is described. The components of susbea downhole optical sensing systems are reviewed and the performance of a new subsea optical fibre feed-through for downhole optical fibre sensing reported.

  19. Post clamp

    NASA Technical Reports Server (NTRS)

    Ramsey, John K. (Inventor); Meyn, Erwin H. (Inventor)

    1990-01-01

    A pair of spaced collars are mounted at right angles on a clamp body by retaining rings which enable the collars to rotate with respect to the clamp body. Mounting posts extend through aligned holes in the collars and clamp body. Each collar can be clamped onto the inserted post while the clamp body remains free to rotate about the post and collar. The clamp body is selectively clamped onto each post.

  20. Downhole telemetry system

    DOEpatents

    Normann, Randy A.; Kadlec, Emil R.

    1994-01-01

    A downhole telemetry system is described for optically communicating to the surface operating parameters of a drill bit during ongoing drilling operations. The downhole telemetry system includes sensors mounted with a drill bit for monitoring at least one operating parameter of the drill bit and generating a signal representative thereof. The downhole telemetry system includes means for transforming and optically communicating the signal to the surface as well as means at the surface for producing a visual display of the optically communicated operating parameters of the drill bit.

  1. Downhole telemetry system

    DOEpatents

    Normann, R.A.; Kadlec, E.R.

    1994-11-08

    A downhole telemetry system is described for optically communicating to the surface operating parameters of a drill bit during ongoing drilling operations. The downhole telemetry system includes sensors mounted with a drill bit for monitoring at least one operating parameter of the drill bit and generating a signal representative thereof. The downhole telemetry system includes means for transforming and optically communicating the signal to the surface as well as means at the surface for producing a visual display of the optically communicated operating parameters of the drill bit. 7 figs.

  2. Downhole Data Transmission System

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David; Dahlgren, Scott; Fox, Joe

    2004-04-06

    A system for transmitting data through a string of down-hole components. In accordance with one aspect, the system includes a plurality of downhole components, such as sections of pipe in a drill string. Each downhole component includes a pin end and a box end, with the pin end of one downhole component being adapted to be connected to the box end of another. Each pin end includes external threads and an internal pin face distal to the external threads. Each box end includes an internal shoulder face with internal threads distal to the internal shoulder face. The internal pin face and the internal shoulder face are aligned with and proximate each other when the pin end of the one component is threaded into a box end of the other component.

  3. Downhole steam quality measurement

    DOEpatents

    Lee, David O.; Montoya, Paul C.; Muir, James F.; Wayland, Jr., J. Robert

    1987-01-01

    An empirical method for the remote sensing of steam quality that can be easily adapted to downhole steam quality measurements by measuring the electrical properties of two-phase flow across electrode grids at low frequencies.

  4. Rigid clamp

    DOEpatents

    Benavides, Gilbert L.; Burt, Jack D.

    1994-01-01

    The invention relates to a clamp mechanism that can be used to attach or temporarily support objects inside of tubular goods. The clamp mechanism can also be modified so that it grips objects. The clamp has a self-centering feature to accommodate out-of-roundness or other internal defections in tubular objects such as pipe. A plurality of clamping shoes are expanded by a linkage which is preferably powered by a motor to contact the inside of a pipe. The motion can be reversed and jaw elements can be connected to the linkage so as to bring the jaws together to grab an object.

  5. Rigid clamp

    DOEpatents

    Benavides, G.L.; Burt, J.D.

    1994-07-12

    The invention relates to a clamp mechanism that can be used to attach or temporarily support objects inside of tubular goods. The clamp mechanism can also be modified so that it grips objects. The clamp has a self-centering feature to accommodate out-of-roundness or other internal defections in tubular objects such as pipe. A plurality of clamping shoes are expanded by a linkage which is preferably powered by a motor to contact the inside of a pipe. The motion can be reversed and jaw elements can be connected to the linkage so as to bring the jaws together to grab an object. 12 figs.

  6. Downhole transmission system

    DOEpatents

    Hall, David R [Provo, UT; Fox, Joe [Spanish Fork, UT

    2008-01-15

    A transmission system in a downhole component comprises a data transmission element in both ends of the downhole component. Each data transmission element houses an electrically conducting coil in a MCEI circular trough. An electrical conductor connects both the transmission elements. The electrical conductor comprises at least three electrically conductive elements insulated from each other. In the preferred embodiment the electrical conductor comprises an electrically conducting outer shield, an electrically conducting inner shield and an electrical conducting core. In some embodiments of the present invention, the electrical conductor comprises an electrically insulating jacket. In other embodiments, the electrical conductor comprises a pair of twisted wires. In some embodiments, the electrical conductor comprises semi-conductive material.

  7. Distributed downhole drilling network

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Fox, Joe; Pixton, David S.

    2006-11-21

    A high-speed downhole network providing real-time data from downhole components of a drilling strings includes a bottom-hole node interfacing to a bottom-hole assembly located proximate the bottom end of a drill string. A top-hole node is connected proximate the top end of the drill string. One or several intermediate nodes are located along the drill string between the bottom-hole node and the top-hole node. The intermediate nodes are configured to receive and transmit data packets transmitted between the bottom-hole node and the top-hole node. A communications link, integrated into the drill string, is used to operably connect the bottom-hole node, the intermediate nodes, and the top-hole node. In selected embodiments, a personal or other computer may be connected to the top-hole node, to analyze data received from the intermediate and bottom-hole nodes.

  8. Downhole Fluid Analyzer Development

    SciTech Connect

    Bill Turner

    2006-11-28

    A novel fiber optic downhole fluid analyzer has been developed for operation in production wells. This device will allow real-time determination of the oil, gas and water fractions of fluids from different zones in a multizone or multilateral completion environment. The device uses near infrared spectroscopy and induced fluorescence measurement to unambiguously determine the oil, water and gas concentrations at all but the highest water cuts. The only downhole components of the system are the fiber optic cable and windows. All of the active components--light sources, sensors, detection electronics and software--will be located at the surface, and will be able to operate multiple downhole probes. Laboratory testing has demonstrated that the sensor can accurately determine oil, water and gas fractions with a less than 5 percent standard error. Once installed in an intelligent completion, this sensor will give the operating company timely information about the fluids arising from various zones or multilaterals in a complex completion pattern, allowing informed decisions to be made on controlling production. The research and development tasks are discussed along with a market analysis.

  9. Downhole steam injector

    DOEpatents

    Donaldson, A. Burl; Hoke, Donald E.

    1983-01-01

    An improved downhole steam injector has an angled water orifice to swirl the water through the device for improved heat transfer before it is converted to steam. The injector also has a sloped diameter reduction in the steam chamber to throw water that collects along the side of the chamber during slant drilling into the flame for conversion to steam. In addition, the output of the flame chamber is beveled to reduce hot spots and increase efficiency, and the fuel-oxidant inputs are arranged to minimize coking.

  10. Method and system for downhole clock synchronization

    DOEpatents

    Hall, David R.; Bartholomew, David B.; Johnson, Monte; Moon, Justin; Koehler, Roger O.

    2006-11-28

    A method and system for use in synchronizing at least two clocks in a downhole network are disclosed. The method comprises determining a total signal latency between a controlling processing element and at least one downhole processing element in a downhole network and sending a synchronizing time over the downhole network to the at least one downhole processing element adjusted for the signal latency. Electronic time stamps may be used to measure latency between processing elements. A system for electrically synchronizing at least two clocks connected to a downhole network comprises a controlling processing element connected to a synchronizing clock in communication over a downhole network with at least one downhole processing element comprising at least one downhole clock. Preferably, the downhole network is integrated into a downhole tool string.

  11. Downhole pulse tube refrigerators

    SciTech Connect

    Swift, G.; Gardner, D.

    1997-12-01

    This report summarizes a preliminary design study to explore the plausibility of using pulse tube refrigeration to cool instruments in a hot down-hole environment. The original motivation was to maintain Dave Reagor`s high-temperature superconducting electronics at 75 K, but the study has evolved to include three target design criteria: cooling at 30 C in a 300 C environment, cooling at 75 K in a 50 C environment, cooling at both 75 K and 30 C in a 250 C environment. These specific temperatures were chosen arbitrarily, as representative of what is possible. The primary goals are low cost, reliability, and small package diameter. Pulse-tube refrigeration is a rapidly growing sub-field of cryogenic refrigeration. The pulse tube refrigerator has recently become the simplest, cheapest, most rugged and reliable low-power cryocooler. The authors expect this technology will be applicable downhole because of the ratio of hot to cold temperatures (in absolute units, such as Kelvin) of interest in deep drilling is comparable to the ratios routinely achieved with cryogenic pulse-tube refrigerators.

  12. Charlie's Clamp.

    ERIC Educational Resources Information Center

    Tarino, Janet Z.

    1998-01-01

    Presents a version of the crush-the-can demonstration which is a hands-on activity in which students use an inexpensive, easily made holder for the can called Charlie's clamp. Includes some suggestions for the follow-up discussion. (DDR)

  13. Downhole thermoacoustic device

    SciTech Connect

    Kuznetsov, O. L.; Malchenok, V. O.; Maxutov, R. A.; Mordukhaev, K. M.; Ostrovsky, A. P.

    1985-12-17

    A downhole thermoacoustic device comprises a heater with a terminal chamber, connected to a source or radiator of acoustic oscillation, including a hollow housing having mounted therein a longitudinal shaft carrying coils with cores in the form of a plurality of flat rings of a magnetostrictive material, operable as the active elements adapted to generate acoustic oscillation. Accommodated intermediate the coils is a member for focusing the acoustic field, in the form of a sleeve, while the longitudinal shaft carries a tube-shaped reflector of acoustic oscillation internally of the core of each coil. The top and bottom portions of the hollow housing of the radiator of acoustic oscillation have mounted therein damping elements including sleeves of a resilient material, while a heat-insulating member including a sleeve with a fluted surface is provided intermediate the terminal chamber of the heater and the hollow housing of the radiator.

  14. Downhole Data Transmission System

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David; Dahlgren, Scott; Fox, Joe

    2003-12-30

    A system for transmitting data through a string of downhole components. In one aspect, the system includes first and second magnetically conductive, electrically insulating elements at both ends of the component. Each element includes a first U-shaped trough with a bottom, first and second sides and an opening between the two sides. Electrically conducting coils are located in each trough. An electrical conductor connects the coils in each component. In operation, a varying current applied to a first coil in one component generates a varying magnetic field in the first magnetically conductive, electrically insulating element, which varying magnetic field is conducted to and thereby produces a varying magnetic field in the second magnetically conductive, electrically insulating element of a connected component, which magnetic field thereby generates a varying electrical current in the second coil in the connected component.

  15. Downhole data transmission system

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S; Dahlgren, Scott; Fox, Joe

    2006-06-20

    A system for transmitting data through a string of downhole components. In one aspect, the system includes first and second magnetically conductive, electrically insulating elements at both ends of the component. Each element includes a first U-shaped trough with a bottom, first and second sides and an opening between the two sides. Electrically conducting coils are located in each trough. An electrical conductor connects the coils in each component. In operation, a varying current applied to a first coil in one component generates a varying magnetic field in the first magnetically conductive, electrically insulating element, which varying magnetic field is conducted to and thereby produces a varying magnetic field in the second magnetically conductive, electrically insulating element of a connected component, which magnetic field thereby generates a varying electrical current in the second coil in the connected component.

  16. Downhole steam quality measurement

    DOEpatents

    Lee, D.O.; Montoya, P.C.; Muir, J.F.; Wayland, J.R. Jr.

    1985-06-19

    The present invention relates to an empirical electrical method for remote sensing of steam quality utilizing flow-through grids which allow measurement of the electrical properties of a flowing two-phase mixture. The measurement of steam quality in the oil field is important to the efficient application of steam assisted recovery of oil. Because of the increased energy content in higher quality steam it is important to maintain the highest possible steam quality at the injection sandface. The effectiveness of a steaming operation without a measure of steam quality downhole close to the point of injection would be difficult to determine. Therefore, a need exists for the remote sensing of steam quality.

  17. Drilling jar for use in a downhole network

    DOEpatents

    Hall, David R.; Fox, Joe; McPherson, James; Pixton, David S.; Briscoe, Michael

    2006-01-31

    Apparatus and methods for integrating transmission cable into the body of selected downhole tools, such as drilling jars, having variable or changing lengths. A wired downhole-drilling tool is disclosed in one embodiment of the invention as including a housing and a mandrel insertable into the housing. A coiled cable is enclosed within the housing and has a first end connected to the housing and a second end connected to the mandrel. The coiled cable is configured to stretch and shorten in accordance with axial movement between the housing and the mandrel. A clamp is used to fix the coiled cable with respect to the housing, the mandrel, or both, to accommodate a change of tension in the coiled cable.

  18. Downhole hydraulic actuated pump

    SciTech Connect

    Roeder, G.K.

    1988-09-06

    This patent describes a downhole hydraulically actuated pump assembly of the type having a main housing within which an engine and pump is enclosed; a connecting rod, an engine piston, a pump plunger, means by which the engine and connecting rod reciprocate the pump plunger and thereby produces fluid; the main housing has a lower end having a formation fluid inlet; and upper end having a power fluid inlet; and, a produced fluid outlet; the plunger divides one marginal end of the housing into upper and lower production chambers; the lower end of the connecting rod is hollow and extends through the plunger into fluid communication with the formation fluid inlet to provide a source of formation fluid for the upper and lower production chambers; a traveling value assembly contained within the plunger and arranged to transfer formation fluid from the hollow rod, through the plunger, and into the upper and lower production chambers, respectively, as the plunger upstrokes and downstrokes; produced fluid valve means by which fluid flows from the upper and lower production chambers and through the produced fluid outlet.

  19. Transducer for downhole drilling components

    DOEpatents

    Hall, David R; Fox, Joe R

    2006-05-30

    A robust transmission element for transmitting information between downhole tools, such as sections of drill pipe, in the presence of hostile environmental conditions, such as heat, dirt, rocks, mud, fluids, lubricants, and the like. The transmission element maintains reliable connectivity between transmission elements, thereby providing an uninterrupted flow of information between drill string components. A transmission element is mounted within a recess proximate a mating surface of a downhole drilling component, such as a section of drill pipe. The transmission element may include an annular housing forming a trough, an electrical conductor disposed within the trough, and an MCEI material disposed between the annular housing and the electrical conductor.

  20. Battery switch for downhole tools

    DOEpatents

    Boling, Brian E.

    2010-02-23

    An electrical circuit for a downhole tool may include a battery, a load electrically connected to the battery, and at least one switch electrically connected in series with the battery and to the load. The at least one switch may be configured to close when a tool temperature exceeds a selected temperature.

  1. Downhole steam generation: material studies

    SciTech Connect

    Beauchamp, E.K.; Weirick, L.J.; Muir, J.F.

    1982-01-01

    One enhanced oil recovery technique for extracting heavy crude from deep reservoirs by steam at the bottom of an injection well. Development of a downhole steam generator that will produce steam and inject it into formations at depths greater than 2500 feet is one objective of a Department of Energy/Sandia National Laboratories development effort - Project DEEP STEAM. Extensive material studies have been performed in support of Project DEEP STEAM; current efforts are devoted primarily to the selection and evaluation of materials for use in downhole steam generators. This paper presents observations of the performance of candidate metals and refractory ceramics (combustor liners) during tests of two prototypic, high pressure, diesel/air combustion, direct contact, downhole steam generators. The first downhole test of such a generator provides data on the performance of various metals (304L, 310 and 316S stainless steels and plain carbon steel) exposed for several weeks to a warm, aerated saltwater environment. A number of corrosion mechanisms acted to cause severely degraded perforance of some of the metals. Several refractory liner designs were evaluated during ground level tests of a generator having a ceramic-lined combustion chamber. Of the two refractories employed, alumina and silicon carbide, the alumina liners exhibited more serious surface degradation and corrosion.

  2. West Flank Downhole Temperature Data

    DOE Data Explorer

    Doug Blankenship

    2008-03-01

    Downhole temperature data for the three wells inside the West Flank FORGE footprint; 83-11, TCH 74-2 and TCH 48-11. TCH 74-2 and TCH 48-11 were both collected before 1990 and 83-11 was collected in 2009. The are compiled into one spreadsheet for ease of visualization.

  3. Downhole steam generator having a downhole oxidant compressor

    DOEpatents

    Fox, R.L.

    1981-01-07

    Am improved apparatus is described for the downhole injection of steam into boreholes, for tertiary oil recovery. It includes an oxidant supply, a fuel supply, an igniter, a water supply, an oxidant compressor, and a combustor assembly. The apparatus is designed for efficiency, preheating of the water, and cooling of the combustion chamber walls. The steam outlet to the borehole is provided with pressure-responsive doors for closing the outlet in response to flameout. (DLC)

  4. Clamp usable as jig and lifting clamp

    DOEpatents

    Tsuyama, Yoshizo

    1976-01-01

    There is provided a clamp which is well suited for use as a lifting clamp for lifting and moving materials of assembly in a shipyard, etc. and as a pulling jig in welding and other operations. The clamp comprises a clamp body including a shackle for engagement with a pulling device and a slot for receiving an article, and a pair of jaws provided on the leg portions of the clamp body on the opposite sides of the slot to grip the article in the slot, one of said jaws consisting of a screw rod and the other jaw consisting of a swivel jaw with a spherical surface, whereby when the article clamped in the slot by the pair of jaws tends to slide in any direction with respect to the clamp body, the article is more positively gripped by the pair of jaws.

  5. Downhole pump with pressure limiter

    SciTech Connect

    Brandell, J.T.

    1982-02-02

    A well testing assembly includes a pressure limiter located between a down-hole pump and an inflatable packer. The pressure limiter includes a housing having first and second housing parts and having an inflation passage disposed therein for communicating a discharge of the down-hole pump with the inflatable packer. A clutch is connected between the first and second housing parts. A biasing spring biases the clutch toward an engaged position. A piston spring biases the clutch toward an engaged position. A piston is associated operatively with the clutch and communicated with the inflation passage for overcoming the biasing spring and moving the clutch to a disengaged position at a predetermined fluid pressure level within the inflation passage. 50 claims.

  6. Mechanically actuated downhole locking sub

    SciTech Connect

    Menard, M.

    1986-09-30

    A mechanically actuated locking sub is described for setting and releasing a downhole tool from an oilwell borehole, having landing nipples, without interrupting a production flow therethrough, comprising: an inner tubular member, having a central conduit and a lower end provided with means for attachment to the downhole tool to be set in or released from the oilwell bore; an outer sleeve member circumferentially encompassing at least a part of the inner tubular member, the sleeve having a plurality of apertures therein; locking dog members intermediate the inner tubular member and the outer sleeve member, having an engaging portion extending outwardly through the apertures of the outer sleeve member; slidable sleeve means intermediate the outer sleeve member and the inner tubular member, movable between a first, extended and a second, retracted position with respect to the inner tubular member; and a double acting spring means engaging the locking dogs; adapted to bias the locking dogs towards the inner tubular member.

  7. Downhole component with a pressure equalization passageway

    DOEpatents

    Hall, David R.; Pixton, David S.; Dahlgren, Scott; Reynolds, Jay T.; Breihan, James W.; Briscoe, Michael A.

    2006-08-22

    The present invention includes a downhole component adapted for transmitting downhole data. The downhole component includes a threaded end on a downhole component. The threaded end furthermore includes an interior region, and exterior region, and a mating surface wherein a cavity is formed. A data transmission element is disposed in the cavity and displaces a volume of the cavity. At least one passageway is formed in the threaded region between interior and exterior regions. The passageway is in fluid communication with both the interior and exterior regions and thereby relieves pressure build up of thread lubricant upon tool joint make up.

  8. Corrosion reference for geothermal downhole materials selection

    SciTech Connect

    Ellis, P.F. II, Smith, C.C.; Keeney, R.C.; Kirk, D.K.; Conover, M.F.

    1983-03-01

    Geothermal downhole conditions that may affect the performance and reliability of selected materials and components used in the drilling, completion, logging, and production of geothermal wells are reviewed. The results of specific research and development efforts aimed at improvement of materials and components for downhole contact with the hostile physicochemical conditions of the geothermal reservoir are discussed. Materials and components covered are tubular goods, stainless steels and non-ferrous metals for high-temperature downhole service, cements for high-temperature geothermal wells, high-temperature elastomers, drilling and completion tools, logging tools, and downhole pumps. (MHR)

  9. Downhole steam generator having a downhole oxidant compressor

    DOEpatents

    Fox, Ronald L.

    1983-01-01

    Apparatus and method for generation of steam in a borehole for penetration into an earth formation wherein a downhole oxidant compressor is used to compress relatively low pressure (atmospheric) oxidant, such as air, to a relatively high pressure prior to mixing with fuel for combustion. The multi-stage compressor receives motive power through a shaft driven by a gas turbine powered by the hot expanding combustion gases. The main flow of compressed oxidant passes through a velocity increasing nozzle formed by a reduced central section of the compressor housing. An oxidant bypass feedpipe leading to peripheral oxidant injection nozzles of the combustion chamber are also provided. The downhole compressor allows effective steam generation in deep wells without need for high pressure surface compressors. Feedback preheater means are provided for preheating fuel in a preheat chamber. Preheating of the water occurs in both a water feed line running from aboveground and in a countercurrent water flow channel surrounding the combustor assembly. The countercurrent water flow channels advantageously serve to cool the combustion chamber wall. The water is injected through slotted inlets along the combustion chamber wall to provide an unstable boundary layer and stripping of the water from the wall for efficient steam generation. Pressure responsive doors are provided at the steam outlet for closing and sealing the combustion chamber from entry of reservoir fluids in the event of a flameout.

  10. Downhole steam generator having a downhole oxidant compressor

    SciTech Connect

    Fox, R.L.

    1983-04-19

    Apparatus and method for generation of steam in a borehole for penetration into an earth formation wherein a downhole oxidant compressor is used to compress relatively low pressure (Atmospheric) oxidant, such as air, to a relatively high pressure prior to mixing with fuel for combustion. The multi-stage compressor receives motive power through a shaft driven by a gas turbine powered by the hot expanding combustion gases. The main flow of compressed oxidant passes through a velocity increasing nozzle formed by a reduced central section of the compressor housing. An oxidant bypass feedpipe leading to peripheral oxidant injection nozzles of the combustion chamber are also provided. The downhole compressor allows effective steam generation in deep wells without need for high pressure surface compressors. Feedback preheater means are provided for preheating fuel in a preheat chamber. Preheating of the water occurs in both a water feed line running from aboveground and in a countercurrent water flow channel surrounding the combustor assembly. The countercurrent water flow channels advantageously serve to cool the combustion chamber wall. The water is injected through slotted inlets along the combustion chamber wall to provide an unstable boundary layer and stripping of the water from the wall for efficient steam generation. Pressure responsive doors are provided at the steam outlet for closing and sealing the combustion chamber from entry of reservoir fluids in the event of a flameout.

  11. Downhole steam injector. [Patent application

    SciTech Connect

    Donaldson, A.B.; Hoke, E.

    1981-06-03

    An improved downhole steam injector has an angled water orifice to swirl the water through the device for improved heat transfer before it is converted to steam. The injector also has a sloped diameter reduction in the steam chamber to throw water that collects along the side of the chamber during slant drilling into the flame for conversion to steam. In addition, the output of the flame chamber is beveled to reduce hot spots and increase efficiency, and the fuel-oxidant inputs are arranged to minimize coking.

  12. Harsh environments electronics : downhole applications.

    SciTech Connect

    Vianco, Paul Thomas

    2011-03-01

    The development and operational sustainment of renewable (geothermal) and non-renewable (fossil fuel) energy resources will be accompanied by increasingly higher costs factors: exploration and site preparation, operational maintenance and repair. Increased government oversight in the wake of the Gulf oil spill will only add to the cost burden. It is important to understand that downhole conditions are not just about elevated temperatures. It is often construed that military electronics are exposed to the upper limit in terms of extreme service environments. Probably the harshest of all service conditions for electronics and electrical equipment are those in oil, gas, and geothermal wells. From the technology perspective, advanced materials, sensors, and microelectronics devices are benefificial to the exploration and sustainment of energy resources, especially in terms of lower costs. Besides the need for the science that creates these breakthroughs - there is also a need for sustained engineering development and testing. Downhole oil, gas, and geothermal well applications can have a wide range of environments and reliability requirements: Temperature, Pressure, Vibration, Corrosion, and Service duration. All too frequently, these conditions are not well-defifined because the application is labeled as 'high temperature'. This ambiguity is problematic when the investigation turns to new approaches for electronic packaging solutions. The objective is to develop harsh environment, electronic packaging that meets customer requirements of cost, performance, and reliability. There are a number of challenges: (1) Materials sets - solder alloys, substrate materials; (2) Manufacturing process - low to middle volumes, low defect counts, new equipment technologies; and (3) Reliability testing - requirements documents, test methods and modeling, relevant standards documents. The cost to develop and sustain renewable and non-renewable energy resources will continue to escalate

  13. Downhole material injector for lost circulation control

    DOEpatents

    Glowka, David A.

    1994-01-01

    Apparatus and method for simultaneously and separately emplacing two streams of different materials through a drillstring in a borehole to a downhole location for lost circulation control. The two streams are mixed outside the drillstring at the desired downhole location and harden only after mixing for control of a lost circulation zone.

  14. Downhole material injector for lost circulation control

    DOEpatents

    Glowka, D.A.

    1991-01-01

    This invention is comprised of an apparatus and method for simultaneously and separately emplacing two streams of different materials through a drillstring in a borehole to a downhole location for lost circulation control. The two streams are mixed outside the drillstring at the desired downhole location and harden only after mixing for control of a lost circulation zone.

  15. Downhole material injector for lost circulation control

    DOEpatents

    Glowka, D.A.

    1994-09-06

    Apparatus and method are disclosed for simultaneously and separately emplacing two streams of different materials through a drill string in a borehole to a downhole location for lost circulation control. The two streams are mixed outside the drill string at the desired downhole location and harden only after mixing for control of a lost circulation zone. 6 figs.

  16. Force-Measuring Clamps

    NASA Technical Reports Server (NTRS)

    Nunnelee, Mark

    2003-01-01

    Force-measuring clamps have been invented to facilitate and simplify the task of measuring the forces or pressures applied to clamped parts. There is a critical need to measure clamping forces or pressures in some applications for example, while bonding sensors to substrates or while clamping any sensitive or delicate parts. Many manufacturers of adhesives and sensors recommend clamping at specific pressures while bonding sensors or during adhesive bonding between parts in general. In the absence of a force-measuring clamp, measurement of clamping force can be cumbersome at best because of the need for additional load sensors and load-indicating equipment. One prior method of measuring clamping force involved the use of load washers or miniature load cells in combination with external power sources and load-indicating equipment. Calibrated spring clamps have also been used. Load washers and miniature load cells constitute additional clamped parts in load paths and can add to the destabilizing effects of loading mechanisms. Spring clamps can lose calibration quickly through weakening of the springs and are limited to the maximum forces that the springs can apply. The basic principle of a force-measuring clamp can be implemented on a clamp of almost any size and can enable measurement of a force of almost any magnitude. No external equipment is needed because the component(s) for transducing the clamping force and the circuitry for supplying power, conditioning the output of the transducers, and displaying the measurement value are all housed on the clamp. In other words, a force-measuring clamp is a complete force-application and force-measurement system all in one package. The advantage of unitary packaging of such a system is that it becomes possible to apply the desired clamping force or pressure with precision and ease.

  17. Force-Measuring Clamp

    NASA Technical Reports Server (NTRS)

    Nunnelee, Mark (Inventor)

    2004-01-01

    A precision clamp that accurately measures force over a wide range of conditions is described. Using a full bridge or other strain gage configuration. the elastic deformation of the clamp is measured or detected by the strain gages. Thc strain gages transmit a signal that corresponds to the degree of stress upon the clamp. Thc strain gage signal is converted to a numeric display. Calibration is achieved by ero and span potentiometers which enable accurate measurements by the force-measuring clamp.

  18. Force-Measuring Clamp

    NASA Technical Reports Server (NTRS)

    Nunnelee, Mark (Inventor)

    2004-01-01

    A precision clamp that accurately measures force over a wide range of conditions is described. Using a full bridge or other strain gage configuration. the elastic deformation of the clamp is measured or detected by the strain gages. Thc strain gages transmit a signal that corresponds to the degree of stress upon the clamp. Thc strain gage signal is converted to a numeric display. Calibration is achieved by ero and span potentiometers which enable accurate measurements by the force-measuring clamp.

  19. Insights from the downhole dynamometer database

    SciTech Connect

    Waggoner, J.R.

    1997-03-01

    The Downhole Dynamometer Database is a compilation of test data collected with a set of five downhole tools built by Albert Engineering under contract to Sandia National Laboratories. The downhole dynamometer tools are memory tools deployed in the sucker rod string with sensors to measure pressure, temperature, load, and acceleration. The acceleration data is processed to yield position, so that a load vs. position dynagraph can be generated using data collected downhole. With five tools in the hole at one time, all measured data and computed dynagraphs from five different positions in the rod string are available. The purpose of the Database is to provide industry with a complete and high quality measurement of downhole sucker rod pumping dynamics. To facilitate use of the database, Sandia has developed a Microsoft Windows-based interface that functions as a visualizer and browser to the more than 40 MBytes of data. The interface also includes a data export feature to allow users to extract data from the database for use in their own programs. Following a brief description of the downhole dynamometer tools, data collection program, and database content, this paper will illustrate a few of the interesting and unique insights gained from the downhole data.

  20. Photovoltaic panel clamp

    SciTech Connect

    Mittan, Margaret Birmingham; Miros, Robert H. J.; Brown, Malcolm P; Stancel, Robert

    2012-06-05

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  1. Photovoltaic panel clamp

    SciTech Connect

    Brown, Malcolm P.; Mittan, Margaret Birmingham; Miros, Robert H. J.; Stancel, Robert

    2013-03-19

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  2. Clamping in Boltzmann machines.

    PubMed

    Livesey, M

    1991-01-01

    A certain assumption that appears in the proof of correctness of the standard Boltzmann machine learning procedure is investigated. The assumption, called the clamping assumption, concerns the behavior of a Boltzmann machine when some of its units are clamped to a fixed state. It is argued that the clamping assumption is essentially an assertion of the time reversibility of a certain Markov chain underlying the behavior of the Boltzmann machine. As such, the clamping assumption is generally false, though it is certainly true of the Boltzmann machines themselves. The author also considers how the concept of the Boltzmann machine may be generalized while retaining the validity of the clamping assumption.

  3. Downhole tool inflatable packer assembly

    SciTech Connect

    Brandell, J.T.

    1984-07-10

    A downhole tool inflatable packer assembly includes an upper packer shoe having a bypass mandrel connected thereto. A packer mandrel adapter has an upper end connected to a lower end of the bypass mandrel. A mandrel cover tube extends downwardly from the packer mandrel adapter. A packer mandrel has an upper portion connected to the packer mandrel adapter. A flow connector and a lower packer adapter are connected in that order below the packer mandrel. A packer flow tube has an upper end received in the bypass mandrel and a lower end received in the flow connector. An inflatable bladder has an upper end connected to the upper packer shoe and a lower end connected to a floating packer shoe which slidably engages the mandrel cover tube. A central flow passage, a packer bypass passage, and an inflation passage are disposed in the packer assembly.

  4. Differential actuating system for downhole tools

    SciTech Connect

    Schultz, R.L.; Manke, K.R.; Skinner, N.G.

    1993-08-24

    A downhole tool apparatus is described, comprising: a housing having a power chamber defined therein, and having power passage means defined in said housing for providing fluid pressure communication between said power chamber and first and second zones of a well; and pressure transfer control means for selectively applying a pressure differential between said first and second zones of said well across said power chamber to operate said downhole tool apparatus.

  5. Radial wedge flange clamp

    DOEpatents

    Smith, Karl H.

    2002-01-01

    A radial wedge flange clamp comprising a pair of flanges each comprising a plurality of peripheral flat wedge facets having flat wedge surfaces and opposed and mating flat surfaces attached to or otherwise engaged with two elements to be joined and including a series of generally U-shaped wedge clamps each having flat wedge interior surfaces and engaging one pair of said peripheral flat wedge facets. Each of said generally U-shaped wedge clamps has in its opposing extremities apertures for the tangential insertion of bolts to apply uniform radial force to said wedge clamps when assembled about said wedge segments.

  6. Quick action clamp

    NASA Technical Reports Server (NTRS)

    Calco, Frank S. (Inventor)

    1991-01-01

    A quick release toggle clamp that utilizes a spring that requires a deliberate positive action for disengagement is presented. The clamp has a sliding bolt that provides a latching mechanism. The bolt is moved by a handle that tends to remain in an engaged position while under tension.

  7. Downhole operations from a dry wellhead

    SciTech Connect

    Engelberg, A.; Suchy, L.

    1983-11-01

    This paper discusses the conditions, limitations, and requirements for conducting downhole operations on a live well from within a dry, 1-atm (100-kPa) production chamber. The paper begins with a description of Can Ocean Resources Ltd.'s subsea wellhead cellars (WHC's). The offshore service system and diving capsule are also described. Various kinds of downhole work are discussed together with the impact of four main operating factors: available space, mission time, safety, and payload. To illustrate better the advantages and limitations of conducting downhole work subsea, downhole operations conducted in the Garoupa field offshore Brazil are recounted. This experience included 5 hot tap operations, 26 polished rod lubricator operations, and 26 wirelining operations-all conducted from dry, 1-atm (100-kPa) WHC's on live wells. Despite the limitations imposed by space, payload, and mission time, the dry, 1-atm (100-kPa) system allows a significant number of downhole operations to be performed safely subsea. The CanOcean dry, 1-atm (100-kPa) diving system equipped with an umbilical provides operators with all necessary support for safe downhole operations. The hydrocarbon gases accumulated in the subsea chamber can be purged and a breathable atmosphere maintained during an operation. Warning and inerting systems can also be employed to prevent flammable mixture buildup. The dry, 1-atm (100-kPa) subsea completion system allows easy and convenient access for routine checkups and more complex downhole operations. The new, medium-duty wireline winch installed outside the diving system allows the service capsule to demate for crew change without cutting the wire. This winch can be used for pulling dummy valves, setting and retrieving gas-lift valves, opening and closing sliding sleeves, swaging out tubing, mechanical perforating, and other operations that require higher line speeds and stronger pulls.

  8. DHE (downhole heat exchangers). [Downhole Heat Exchangers (DHE)

    SciTech Connect

    Culver, G.

    1990-11-01

    The use of downhole heat exchangers (DHE) for residential or commercial space and domestic water heating and other applications has several desirable features. Systems are nearly or completely passive -- that is, no or very little geothermal water or steam is produced from the well either reducing or completely eliminating surface environmental concerns and the need for disposal systems or injection wells. Initial cost of pumps and installation are eliminated or reduced along with pumping power costs and maintenance costs associated with pumping often corrosive geothermal fluids. Many residential and small commercial systems do not require circulating pumps because the density difference in the incoming and outgoing sides of the loop are sufficient to overcome circulating friction losses in the entire system. The major disadvantage of DHEs is their dependence on natural heat flow. In areas where geological conditions provide high permeability and a natural hydraulic gradient, DHEs can provide a substantial quantity of heat. A single 500-ft (152 m) well in Klamath Falls, Oregon, supplies over one megawatt thermal and output is apparently limited by the surface area of pipe that can be installed in the well bore. In contrast, DHEs used in conjunction with heat pumps may supply less than 8 KW from a well of similar depth. Here output is limited by conductive heat flow with perhaps a small contribution from convection near the well bore. The highest capacity DHE reported to date, in Turkey, supplies 6 MW thermal from an 820-ft (250 m) well. There were two main goals for this project. The first was to gather, disseminate and exchange internationally information on DHES. The second was to perform experiments that would provide insight into well bore/aquifer interaction and thereby provide more information on which to base DHE designs. 27 refs., 31 figs., 3 tabs.

  9. 275 C Downhole Microcomputer System

    SciTech Connect

    Chris Hutchens; Hooi Miin Soo

    2008-08-31

    An HC11 controller IC and along with serial SRAM and ROM support ICs chip set were developed to support a data acquisition and control for extreme temperature/harsh environment conditions greater than 275 C. The 68HC11 microprocessor is widely used in well logging tools for control, data acquisition, and signal processing applications and was the logical choice for a downhole controller. This extreme temperature version of the 68HC11 enables new high temperature designs and additionally allows 68HC11-based well logging tools and MWD tools to be upgraded for high temperature operation in deep gas reservoirs, The microcomputer chip consists of the microprocessor ALU, a small boot ROM, 4 kbyte data RAM, counter/timer unit, serial peripheral interface (SPI), asynchronous serial interface (SCI), and the A, B, C, and D parallel ports. The chip is code compatible with the single chip mode commercial 68HC11 except for the absence of the analog to digital converter system. To avoid mask programmed internal ROM, a boot program is used to load the microcomputer program from an external mask SPI ROM. A SPI RAM IC completes the chip set and allows data RAM to be added in 4 kbyte increments. The HC11 controller IC chip set is implemented in the Peregrine Semiconductor 0.5 micron Silicon-on-Sapphire (SOS) process using a custom high temperature cell library developed at Oklahoma State University. Yield data is presented for all, the HC11, SPI-RAM and ROM. The lessons learned in this project were extended to the successful development of two high temperature versions of the LEON3 and a companion 8 Kbyte SRAM, a 200 C version for the Navy and a 275 C version for the gas industry.

  10. Loaded transducer for downhole drilling components

    DOEpatents

    Hall, David R.; Fox, Joe; Daly, Jeffery E.

    2009-05-05

    A system for transmitting information between downhole components has a first downhole component with a first mating surface and a second downhole component having a second mating surface configured to substantially mate with the first mating surface. The system also has a first transmission element with a first communicating surface and is mounted within a recess in the first mating surface. The first transmission element also has an angled surface. The recess has a side with multiple slopes for interacting with the angled surface, each slope exerting a different spring force on the first transmission element. A second transmission element has a second communicating surface mounted proximate the second mating surface and adapted to communicate with the first communicating surface.

  11. Dual-cone double-helical downhole logging device

    DOEpatents

    Yu, Jiunn S.

    1984-01-01

    A broadband downhole logging device includes a double-helix coil wrapped over a dielectric support and surrounded by a dielectric shield. The device may also include a second coil longitudinally aligned with a first coil and enclosed within the same shield for measuring magnetic permeability of downhole formations and six additional coils for accurately determining downhole parameters.

  12. Loaded Transducer Fpr Downhole Drilling Component

    DOEpatents

    Hall, David R.; Hall, H. Tracy; Pixton, David; Dahlgren, Scott; Sneddon, Cameron; Briscoe, Michael; Fox, Joe

    2005-07-05

    A robust transmission element for transmitting information between downhole tools, such as sections of drill pipe, in the presence of hostile environmental conditions, such as heat, dirt, rocks, mud, fluids, lubricants, and the like. The transmission element maintains reliable connectivity between transmission elements, thereby providing an uninterrupted flow of information between drill string components. A transmission element is mounted within a recess proximate a mating surface of a downhole drilling component, such as a section of drill pipe. To close gaps present between transmission elements, transmission elements may be biased with a "spring force," urging them closer together.

  13. Loaded transducer for downhole drilling components

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Briscoe, Michael A.; Dahlgren, Scott Steven; Fox, Joe; Sneddon, Cameron

    2006-02-21

    A robust transmission element for transmitting information between downhole tools, such as sections of drill pipe, in the presence of hostile environmental conditions, such as heat, dirt, rocks, mud, fluids, lubricants, and the like. The transmission element maintains reliable connectivity between transmission elements, thereby providing an uninterrupted flow of information between drill string components. A transmission element is mounted within a recess proximate a mating surface of a downhole drilling component, such as a section of drill pipe. To close gaps present between transmission elements, transmission elements may be biased with a "spring force, urging them closer together."

  14. A monogenean without clamps

    USDA-ARS?s Scientific Manuscript database

    Ectoparasites face a daily challenge: to remain attached to their host. Polyopisthocotylean monogeneans attach to the surface of fish gills by highly specialized structures, the sclerotized clamps. In the original description of the protomicrocotylid species Lethacotyle fijiensis, described 50 years...

  15. Laser beam guard clamps

    DOEpatents

    Dickson, Richard K.

    2010-09-07

    A quick insert and release laser beam guard panel clamping apparatus having a base plate mountable on an optical table, a first jaw affixed to the base plate, and a spring-loaded second jaw slidably carried by the base plate to exert a clamping force. The first and second jaws each having a face acutely angled relative to the other face to form a V-shaped, open channel mouth, which enables wedge-action jaw separation by and subsequent clamping of a laser beam guard panel inserted through the open channel mouth. Preferably, the clamping apparatus also includes a support structure having an open slot aperture which is positioned over and parallel with the open channel mouth.

  16. Downhole Elemental Analysis with LIBS

    NASA Technical Reports Server (NTRS)

    Moreschini, Paolo; Zacny, Kris; Rickman, Doug

    2011-01-01

    vertical stage; a second actuator at the top of the downhole probe allows radial scanning of the borehole. Analysis of iron and titanium in lunar simulant with LIBS was performed in air using the method of standard addition. The results for lunar simulant NU-LHT-2M show a value for the concentration of iron ranging between 2.29% and 3.05% depending on the atomic line selected. The accepted value for the sample analyzed is 2.83%, showing the capability for the system in development to provide qualitative and semi-quantitative analysis in real-time.

  17. Downhole elemental analysis with LIBS

    NASA Astrophysics Data System (ADS)

    Moreschini, P.; Zacny, K.; Rickman, D.

    2011-12-01

    top of the downhole probe allows radial scanning of the borehole. Analysis of iron and titanium in lunar simulant with LIBS was performed in air using the method of standard addition. The results for lunar simulant NU-LHT-2M show a value for the concentration of iron ranging between 2.29% and 3.05% depending on the atomic line selected. The accepted value for the sample analyzed is 2.83%, showing the capability for the system in development to provide qualitative and semi-quantitative analysis in real-time.

  18. Sperm Patch-Clamp

    PubMed Central

    Lishko, Polina; Clapham, David E.; Navarro, Betsy; Kirichok, Yuriy

    2014-01-01

    Sperm intracellular pH and calcium concentration ([Ca2+]i) are two central factors that control sperm activity within the female reproductive tract. As such, the ion channels of the sperm plasma membrane that alter intracellular sperm [Ca2+] and pH play important roles in sperm physiology and the process of fertilization. Indeed, sperm ion channels regulate sperm motility, control sperm chemotaxis toward the egg in some species, and may trigger the acrosome reaction. Until recently, our understanding of these important molecules was rudimentary due to the inability to patch-clamp spermatozoa and directly record the activity of these ion channels under voltage clamp. Recently, we overcame this technical barrier and developed a method for reproducible application of the patch-clamp technique to mouse and human spermatozoa. This chapter covers important aspects of application of the patch-clamp technique to spermatozoa, such as selection of the electrophysiological equipment, isolation of spermatozoa for patch-clamp experiments, formation of the gigaohm seal with spermatozoa, and transition into the whole-cell mode of recording. We also discuss potential pitfalls in application of the patch-clamp technique to flagellar ion channels. PMID:23522465

  19. Development of PDC Bits for Downhole Motors

    SciTech Connect

    Karasawa, H.; Ohno, T.

    1995-01-01

    To develop polycrystalline hamond compact (PDC) bits of the full-face type which can be applied to downhole motor drilling, drilling tests for granite and two types of andesite were conducted using bits with 98.43 and 142.88 mm diameters. The bits successfully drilled these types of rock at rotary speeds from 300 to 400 rpm.

  20. Remote down-hole well telemetry

    DOEpatents

    Briles, Scott D.; Neagley, Daniel L.; Coates, Don M.; Freund, Samuel M.

    2004-07-20

    The present invention includes an apparatus and method for telemetry communication with oil-well monitoring and recording instruments located in the vicinity of the bottom of gas or oil recovery pipes. Such instruments are currently monitored using electrical cabling that is inserted into the pipes; cabling has a short life in this environment, and requires periodic replacement with the concomitant, costly shutdown of the well. Modulated reflectance, a wireless communication method that does not require signal transmission power from the telemetry package will provide a long-lived and reliable way to monitor down-hole conditions. Normal wireless technology is not practical since batteries and capacitors have to frequently be replaced or recharged, again with the well being removed from service. RF energy generated above ground can also be received, converted and stored down-hole without the use of wires, for actuating down-hole valves, as one example. Although modulated reflectance reduces or eliminates the loss of energy at the sensor package because energy is not consumed, during the transmission process, additional stored extra energy down-hole is needed.

  1. Expandable Metal Liner For Downhole Components

    DOEpatents

    Hall, David R.; Fox, Joe R.

    2004-10-05

    A liner for an annular downhole component is comprised of an expandable metal tube having indentations along its surface. The indentations are formed in the wall of the tube either by drawing the tube through a die, by hydroforming, by stamping, or roll forming and may extend axially, radially, or spirally along its wall. The indentations accommodate radial and axial expansion of the tube within the downhole component. The tube is inserted into the annular component and deformed to match an inside surface of the component. The tube may be expanded using a hydroforming process or by drawing a mandrel through the tube. The tube may be expanded in such a manner so as to place it in compression against the inside wall of the component. The tube is useful for improving component hydraulics, shielding components from contamination, inhibiting corrosion, and preventing wear to the downhole component during use. It may also be useful for positioning conduit and insulated conductors within the component. An insulating material may be disposed between the tube and the component in order to prevent galvanic corrosion of the downhole component.

  2. Clamping characteristics study on different types of clamping unit

    SciTech Connect

    Jiao, Zhiwei; Liu, Haichao; Xie, Pengcheng; Yang, Weimin

    2015-05-22

    Plastic products are becoming more and more widely used in aerospace, IT, digital electronics and many other fields. With the development of technology, the requirement of product precision is getting higher and higher. However, type and working performance of clamping unit play a decisive role in product precision. Clamping characteristics of different types of clamping unit are discussed in this article, which use finite element numerical analysis method through the software ABAQUS to study the clamping uniformity, and detect the clamping force repeatability precision. The result shows that compared with toggled three-platen clamping unit, clamping characteristics of internal circulation two-platen clamping unit are better, for instance, its mold cavity deformation and force that bars and mold parting surface suffered are more uniform, and its clamping uniformity and repeatability precision is also better.

  3. Clamp for detonating fuze

    NASA Technical Reports Server (NTRS)

    Holderman, E. J.

    1968-01-01

    Quick acting clamp provides physical support for a closely confined detonating fuse in an application requiring removal and replacement at frequent intervals during test. It can be designed with a base of any required strength and configuration to permit the insertion of an object.

  4. New downhole tool designed for well servicing

    SciTech Connect

    Schempf, F.J.

    1982-02-01

    Miracle Tool, Inc. is finding quite a large market for its single product line - the miracle tool. Basically, the tool is designed to perform numerous downhole operations in shallow or deep completion and workover drilling. Unlike most other tools used for cleaning out cased or open holes, the miracle tool operates in a low fluid level environment. The tool uses a method for circulating fluid downhole, without the added expense of loading the hole with pumped-down fluid. The all-stainless steel tool is designed to remove frac and, retrieve bridge plugs, drill out caved-in holes, drill out cement and hydromite plugs, and fish for small junk, including drill bit cones. The application of the miracle tool to drilling and fishing are discussed.

  5. Polished Downhole Transducer Having Improved Signal Coupling

    DOEpatents

    Hall, David R.; Fox, Joe

    2006-03-28

    Apparatus and methods to improve signal coupling in downhole inductive transmission elements to reduce the dispersion of magnetic energy at the tool joints and to provide consistent impedance and contact between transmission elements located along the drill string. A transmission element for transmitting information between downhole tools is disclosed in one embodiment of the invention as including an annular core constructed of a magnetically conductive material. The annular core forms an open channel around its circumference and is configured to form a closed channel by mating with a corresponding annular core along an annular mating surface. The mating surface is polished to provide improved magnetic coupling with the corresponding annular core. An annular conductor is disposed within the open channel.

  6. Downhole transmission system comprising a coaxial capacitor

    SciTech Connect

    Hall, David R; Pixton, David S; Johnson, Monte L; Bartholomew, David B; Hall, Jr., H. Tracy; Rawle, Michael

    2011-05-24

    A transmission system in a downhole component comprises a plurality of data transmission elements. A coaxial cable having an inner conductor and an outer conductor is disposed within a passage in the downhole component such that at least one capacitor is disposed in the passage and having a first terminal coupled to the inner conductor and a second terminal coupled to the outer conductor. Preferably the transmission element comprises an electrically conducting coil. Preferably, within the passage a connector is adapted to electrically connect the inner conductor of the coaxial cable and the lead wire. The coaxial capacitor may be disposed between and in electrically communication with the connector and the passage. In another embodiment a connector is adapted to electrical connect a first and a second portion of the inner conductor of the coaxial cable and a coaxial capacitor is in electrical communication with the connector and the passage.

  7. Data transmission element for downhole drilling components

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Dahlgren, Scott; Fox, Joe; Sneddon, Cameron; Briscoe, Michael

    2006-01-31

    A robust data transmission element for transmitting information between downhole components, such as sections of drill pipe, in the presence of hostile environmental conditions, such as heat, dirt, rocks, mud, fluids, lubricants, and the like. The data transmission element components include a generally U-shaped annular housing, a generally U-shaped magnetically conductive, electrically insulating element such as ferrite, and an insulated conductor. Features on the magnetically conducting, electrically insulating element and the annular housing create a pocket when assembled. The data transmission element is filled with a polymer to retain the components within the annular housing by filling the pocket with the polymer. The polymer can bond with the annular housing and the insulated conductor but preferably not the magnetically conductive, electrically insulating element. A data transmission element is mounted within a recess proximate a mating surface of a downhole drilling component, such as a section of drill pipe.

  8. Downhole pipe selection for acoustic telemetry

    DOEpatents

    Drumheller, Douglas S.

    1995-01-01

    A system for transmitting signals along a downhole string including a plurality of serially connected tubular pipes such as drill or production pipes, a transmitter for transmitting a signal along the string and a receiver for receiving the signal placed along the string at a location spaced from said transmitting means, wherein the pipes between the transmitter and the receiver are ordered according to length of tube to minimize loss of signal from said transmitter to said receiver.

  9. Downhole pipe selection for acoustic telemetry

    DOEpatents

    Drumheller, D.S.

    1995-12-19

    A system is described for transmitting signals along a downhole string including a plurality of serially connected tubular pipes such as drill or production pipes, a transmitter for transmitting a signal along the string and a receiver for receiving the signal placed along the string at a location spaced from said transmitting means, wherein the pipes between the transmitter and the receiver are ordered according to length of tube to minimize loss of signal from said transmitter to said receiver. 7 figs.

  10. Downhole drilling network using burst modulation techniques

    DOEpatents

    Hall; David R. , Fox; Joe

    2007-04-03

    A downhole drilling system is disclosed in one aspect of the present invention as including a drill string and a transmission line integrated into the drill string. Multiple network nodes are installed at selected intervals along the drill string and are adapted to communicate with one another through the transmission line. In order to efficiently allocate the available bandwidth, the network nodes are configured to use any of numerous burst modulation techniques to transmit data.

  11. Downhole Seismic Monitoring at the Geysers

    SciTech Connect

    Rutledge, J.T.; Anderson, T.D.; Fairbanks, T.D.; Albright, J.N.

    1999-10-17

    A 500-ft length, 6-level, 3-component, vertical geophone array was permanently deployed within the upper 800 ft of Unocal's well GDCF 63-29 during a plug and abandonment operation on April 7, 1998. The downhole array remains operational after a period of 1 year, at a temperature of about 150 C. Continuous monitoring and analysis of shallow seismicity (<4000 ft deep) has been conducted over that same 1-year period. The downhole array was supplemented with 4 surface stations in late-1998 and early-1999 to help constrain locations of shallow seismicity. Locations occurring within about 1 km ({approximately}3000 ft) of the array have been determined for a subset of high-frequency events detected on the downhole and surface stations for the 10-week period January 6 to March 16, 1999. These events are distinct from surface-monitored seismicity at The Geysers in that they occur predominantly above the producing reservoir, at depths ranging from about 1200 to 4000 ft depth (1450 to -1350 ft elevation). The shallow seismicity shows a northeast striking trend, similar to seismicity trends mapped deeper within the reservoir and the strike of the predominant surface lineament observed over the productive field.

  12. Method and apparatus of assessing down-hole drilling conditions

    DOEpatents

    Hall, David R.; Pixton, David S.; Johnson, Monte L.; Bartholomew, David B.; Fox, Joe

    2007-04-24

    A method and apparatus for use in assessing down-hole drilling conditions are disclosed. The apparatus includes a drill string, a plurality of sensors, a computing device, and a down-hole network. The sensors are distributed along the length of the drill string and are capable of sensing localized down-hole conditions while drilling. The computing device is coupled to at least one sensor of the plurality of sensors. The data is transmitted from the sensors to the computing device over the down-hole network. The computing device analyzes data output by the sensors and representative of the sensed localized conditions to assess the down-hole drilling conditions. The method includes sensing localized drilling conditions at a plurality of points distributed along the length of a drill string during drilling operations; transmitting data representative of the sensed localized conditions to a predetermined location; and analyzing the transmitted data to assess the down-hole drilling conditions.

  13. Design and Analysis of an Active Helical Drive Downhole Tractor

    NASA Astrophysics Data System (ADS)

    LI, Yujia; LIU, Qingyou; CHEN, Yonghua; REN, Tao

    2017-03-01

    During oil-gas well drilling and completion, downhole tools and apparatus should be conveyed to the destination to complete a series of downhole works. Downhole tractors have been used to convey tools in complex wellbores, however a very large tractive force is needed to carry more downhole tools to accomplish works with high efficiency. A novel serial active helical drive downhole tractor which has significantly improved performance compared with previous work is proposed. All previously reported helical drive downhole tractors need stators to balance the torque generated by the rotator. By contrast, the proposed serial downhole tractor does not need a stator; several rotator-driven units should only be connected to one another to achieve a tractive force multifold higher than that was previously reported. As a result, the length of a single unit is shortened, and the motion flexibility of the downhole tractor is increased. The major performance indicators, namely, gear ratio, velocity, and tractive force, are analyzed. Experimental results show that the maximum tractive force of a single-unit prototype with a length of 900 mm is 165.3 kg or 1620 N. The analysis and experimental results show that the proposed design has considerable potential for downhole works.

  14. Design and Analysis of an Active Helical Drive Downhole Tractor

    NASA Astrophysics Data System (ADS)

    LI, Yujia; LIU, Qingyou; CHEN, Yonghua; REN, Tao

    2017-03-01

    During oil-gas well drilling and completion, downhole tools and apparatus should be conveyed to the destination to complete a series of downhole works. Downhole tractors have been used to convey tools in complex wellbores, however a very large tractive force is needed to carry more downhole tools to accomplish works with high efficiency. A novel serial active helical drive downhole tractor which has significantly improved performance compared with previous work is proposed. All previously reported helical drive downhole tractors need stators to balance the torque generated by the rotator. By contrast, the proposed serial downhole tractor does not need a stator; several rotator-driven units should only be connected to one another to achieve a tractive force multifold higher than that was previously reported. As a result, the length of a single unit is shortened, and the motion flexibility of the downhole tractor is increased. The major performance indicators, namely, gear ratio, velocity, and tractive force, are analyzed. Experimental results show that the maximum tractive force of a single-unit prototype with a length of 900 mm is 165.3 kg or 1620 N. The analysis and experimental results show that the proposed design has considerable potential for downhole works.

  15. Downhole seismic logging for high-resolution reflection surveying in unconsolidated overburden

    SciTech Connect

    Hunter, J.A.; Pullan, S.E.; Burns, R.A.; Good, R.L.; Harris, J.B.; Pugin, A.; Skvortsov, A.; Goriainov, N.N.

    1998-07-01

    Downhole seismic velocity logging techniques have been developed and applied in support of high-resolution reflection seismic surveys. Data obtained from downhole seismic logging can provide accurate velocity-depth functions and directly correlate seismic reflections to depth. The methodologies described in this paper are designed for slimhole applications in plastic-cased boreholes (minimum ID of 50 mm) and with source and detector arrays that yield similar frequency ranges and vertical depth resolutions as the surface reflection surveys. Compressional- (P-) wave logging uses a multichannel hydrophone array with 0.5-m detector spacings in a fluid-filled borehole and a high-frequency, in-hole shotgun source at the surface. Overlapping array positions downhole results in redundant first-arrival data which can be processed to provide accurate interval velocities. The data also can be displayed as a record suite, showing reflections and directly correlating reflection events with depths. Example applications include identification of gas zones, lithological boundaries within unconsolidated sediments, and the overburden-bedrock interface. Shear- (S-) wave logging uses a slimhole, well-locked, three-component (3-C) geophone pod and a horizontally polarized, hammer-and-loaded-plate source at ground surface. In unconsolidated sediments, shear-wave velocity contrasts can be associated with changes in material density or dynamic shear modulus, which in turn can be related to consolidation. Example applications include identification of a lithological boundary for earthquake hazard applications and mapping massive ice within permafrost materials.

  16. Evaluation of alternatives in downhole steam generation

    SciTech Connect

    Not Available

    1981-09-01

    The objective is to evaluate two alternative approaches, taken by Sandia and World Energy Systems in their development of downhole steam generators, in terms of the requirements for commercialization and the technical and economic goals which each one must reach in order to satisfy those requirements. The conclusions are as follows: (1) The high-pressure downhole steam generator being developed by Sandia has potential for commercialization for production of heavy oil in the next few years. (2) The critical performance parameter is oil yield and can be expressed in terms of bbl oil/million Btu of steam generated; the yield which is required for clear economic attractiveness of the high-pressure generator is 1.2 bbl/10/sup 6/ Btu which corresponds to 5.3 bbl steam/bbl oil. (3) The downhole hydrogen/oxygen burner being developed by World Energy Systems has potential for commercialization for production of resources which are now unproducible or uneconomical. (4) The critical performance provided in nearly 1100 pre- and post-training forms returned by the solarr and 201 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Ground water data indicate that high uranium values occur almost exclusively in the western portion of the quadrangle along the eastern portion of the Williston Basin. These high uranium values occur primarily in Pleistocene delta deposits and in glacial outwash and till. Groundwater in this area is geographically associated with high values of calcium, magnesium, manganese, potassium, selenium, strontium, sulfate, and total alkalinity. Stream sediment data indicate high uranium value the relative concentration of Sm/sup 2 +/ and Sm/sup 3 +/ ions changes with the change of composition.

  17. Sullair low pressure downhole steam generator system

    SciTech Connect

    Klingler, R.P.

    1982-01-01

    Scientists and engineers are continually searching for techniques to release more oil from known reservoirs to improve productivity and lessen dependence on new finds. Based on a record of success dating to the early 1960s, thermal methods, and in particular methodology for steam treating deep reservoirs, have become an area of intense activity. In the U.S. alone, it has been reported that ca 300,000 bopd was produced in 1981 by traditional surface steam methods. Of the thermal techniques emerging, downhole steam generation is of particular interest in this discussion. 11 references.

  18. High pressure combustor for generating steam downhole

    SciTech Connect

    Retallick, W.B.

    1983-08-09

    A catalytic combustor for generating a mixture of steam and combustion gas is located downhole in oil well, so that the gas mixture can be injected directly into the oil reservoir to displace heavy oils from the reservoir. There can be a single stage of catalytic combustion, or there can be a stage of thermal combustion followed by a catalytic stage. In either case the purpose of the catalyst is drive the combustion to completion so that the gas mixture contains no soot that would plug the reservoir.

  19. Immediate or early cord clamping vs delayed clamping.

    PubMed

    Hutchon, D J R

    2012-11-01

    Over the past 40 years, there have been a number of review articles attempting to rationalise cord clamping practice. Early cord clamping was originally thought to be important in active management of the third stage of labour, but this was never evidence based. Without an evidence base to justify it, early cord clamping in clinical practice has remained very variable. There is good evidence that early cord clamping leads to hypovolaemia, anaemia and low iron stores in the neonate. We review all the evidence and discuss possible reasons why some obstetricians and midwives persevere with early clamping. We explain how a variable definition, defective education, deferred responsibility between obstetrician and paediatrician, variable guidelines and a lack of appreciation for the potential harm of the intervention, have all contributed. This study describes how the need for early cord clamping can be avoided in practically all clinical complications of birth.

  20. Apparatus for responding to an anomalous change in downhole pressure

    DOEpatents

    Hall, David R.; Fox, Joe; Wilde, Tyson; Barlow, Jonathan S.

    2010-04-13

    A method of responding to an anomalous change in downhole pressure in a bore hole comprises detecting the anomalous change in downhole pressure, sending a signal along the segmented electromagnetic transmission path, receiving the signal, and performing a automated response. The anomalous change in downhole pressure is detected at a first location along a segmented electromagnetic transmission path, and the segmented electromagnetic transmission path is integrated into the tool string. The signal is received by at least one receiver in communication with the segmented electromagnetic transmission path. The automated response is performed along the tool string. Disclosed is an apparatus for responding to an anomalous change in downhole pressure in a downhole tool string, comprising a segmented electromagnetic transmission path connecting one or more receivers and at least one pressure sensor.

  1. Downhole delay assembly for blasting with series delay

    DOEpatents

    Ricketts, Thomas E.

    1982-01-01

    A downhole delay assembly is provided which can be placed into a blasthole for initiation of explosive in the blasthole. The downhole delay assembly includes at least two detonating time delay devices in series in order to effect a time delay of longer than about 200 milliseconds in a round of explosions. The downhole delay assembly provides a protective housing to prevent detonation of explosive in the blasthole in response to the detonation of the first detonating time delay device. There is further provided a connection between the first and second time delay devices. The connection is responsive to the detonation of the first detonating time delay device and initiates the second detonating time delay device. A plurality of such downhole delay assemblies are placed downhole in unfragmented formation and are initiated simultaneously for providing a round of explosive expansions. The explosive expansions can be used to form an in situ oil shale retort containing a fragmented permeable mass of formation particles.

  2. Method for bonding a transmission line to a downhole tool

    DOEpatents

    Hall, David R.; Fox, Joe

    2007-11-06

    An apparatus for bonding a transmission line to the central bore of a downhole tool includes a pre-formed interface for bonding a transmission line to the inside diameter of a downhole tool. The pre-formed interface includes a first surface that substantially conforms to the outside contour of a transmission line and a second surface that substantially conforms to the inside diameter of a downhole tool. In another aspect of the invention, a method for bonding a transmission line to the inside diameter of a downhole tool includes positioning a transmission line near the inside wall of a downhole tool and placing a mold near the transmission line and the inside wall. The method further includes injecting a bonding material into the mold and curing the bonding material such that the bonding material bonds the transmission line to the inside wall.

  3. Cantilever clamp fitting

    NASA Technical Reports Server (NTRS)

    Melton, Patrick B. (Inventor)

    1989-01-01

    A device is disclosed for sealing and clamping a cylindrical element which is to be attached to an object such as a wall, a pressurized vessel or another cylindrical element. The device includes a gland having an inner cylindrical wall, which is threaded at one end and is attached at a bendable end to a deformable portion, which in turn is attached to one end of a conical cantilever structure. The other end of the cantilever structure connects at a bendable area to one end of an outer cylindrical wall. The opposite end of cylindrical wall terminates in a thickened portion, the radially outer surface of which is adapted to accommodate a tool for rotating the gland. The terminal end of cylindrical wall also includes an abutment surface, which is adapted to engage a seal, which in turn engages a surface of a receiver. The receiver further includes a threaded portion for engagement with the threaded portion of gland whereby a tightening rotation of gland relative to receiver will cause relative movement between cylindrical walls and of gland. This movement causes a rotation of the conical structure and thus a bending action at bending area and at the bending end of the upper end of inner cylindrical wall. These rotational and bending actions result in a forcing of the deformable portion radially inwardly so as to contact and deform a pipe. This forcible contact creates a seal between gland and pipe, and simultaneously clamps the pipe in position.

  4. Data Transmission System For A Downhole Component

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David; Dahlgren, Scott; Sneddon, Cameron; Fox, Joe; Briscoe, Michael

    2005-01-18

    The invention is a system for transmitting data through a string of downhole components. In accordance with one aspect of the invention, the system includes a plurality of downhole components, such as sections of pipe in a drill string. Each component has a first and second end, with a first communication element located at the first end and a second communication element located at the second end. Each communication element includes a first contact and a second contact. The system also includes a coaxial cable running between the first and second communication elements, the coaxial cable having a conductive tube and a conductive core within it. The system also includes a first and second connector for connecting the first and second communication elements respectively to the coaxial cable. Each connector includes a conductive sleeve, lying concentrically within the conductive tube, which fits around and makes electrical contact with the conductive core. The conductive sleeve is electrically isolated from the conductive tube. The conductive sleeve of the first connector is in electrical contact with the first contact of the first communication element, the conductive sleeve of the second connector is in electrical contact with the first contact of the second communication element, and the conductive tube is in electrical contact with both the second contact of the first communication element and the second contact of the second communication element.

  5. Data transmission system for a downhole component

    DOEpatents

    Hall, David R.; Hall, Jr., Tracy H.; Pixton, David S.; Dahlgren, Scott Steven; Fox, Joe; Sneddon, Cameron; Briscoe, Michael A.

    2006-05-09

    The invention is a system for transmitting data through a string of downhole components. In accordance with one aspect of the invention, the system includes a plurality of downhole components, such as sections of pipe in a drill string. Each component has a first and second end, with a first communication element located at the first end and a second communication element located at the second end. Each communication element includes a first contact and a second contact. The system also includes a coaxial cable running between the first and second communication elements, the coaxial cable having a conductive tube and a conductive core within it. The system also includes a first and second connector for connecting the first and second communication elements respectively to the coaxial cable. Each connector includes a conductive sleeve, lying concentrically within the conductive tube, which fits around and makes electrical contact with the conductive core. The conductive sleeve is electrically isolated from the conductive tube. The conductive sleeve of the first connector is in electrical contact with the first contact of the first communication element, the conductive sleeve of the second connector is in electrical contact with the first contact of the second communication element, and the conductive tube is in electrical contact with both the second contact of the first communication element and the second contact of the second communication element.

  6. An Overview of Downhole Imaging Tools

    NASA Astrophysics Data System (ADS)

    Luthi, S. M.

    In this presentation we give an overview of downhole imaging tools that can be used to image the borehole wall and its vicinity with a variety of physical methods. Among these are ultrasonic scans with a rotating transducer that performs a pulse-echo mea- surement in rapid succession. This gives a transit time and a reflected amplitude image of the borehole wall. Electrical imaging is done with a whole family of measurements that operate mostly in the low AC range. All of them feature a number of electrodes that is inversely proportional to the desired resolution and depth of investigation. They image layering, fracturing and other heterogeneities in the rocks traversed by the bore- hole. Some of these images can be recorded and transmitted to the surface in real-time while the well is being drilled. Imaging using nuclear methods is also possible, for ex- ample for the natural radioactivity, density, or neutron porosity of the rock. However, these devices have generally low spatial resolutions. Finally, optical imaging is pos- sible in translucent and slightly opaque muds with a downhole video camera. Recent developments have resulted in a device that can withstand high pressures and temper- atures and that transmits live video images to the surface in real-time. This method has the highest resolution but is of limited applicability in the oil industry where gener- ally opaque muds are used. These images can be successfully used to determined the structural and intrinsic properties of rock traversed by a borehole.

  7. Better downhole gas separation optimizes production

    SciTech Connect

    Ryan, J. )

    1994-03-01

    Pumping efficiency, impaired by gas produced through a downhole pump, can be improved with subsurface separators and gas anchors. The result is longer equipment life and enhanced well productivity. The physical mechanism that separates free or solution gas from fluids in a well is a gas separator, which operates by virtue of gas and fluid velocities in the well bore and downhole production equipment. When oil containing solution gas crosses the perforations or slots in a mud anchor, a pressure drop occurs, resulting in the evolution of free gas bubbles. Agitation, direction changes and sudden velocity increases also aid the evolution of free gas. Depending upon bubble size and shape and fluid viscosity and velocity, the free gas bubbles will attempt to migrate upward while the fluid moves down. If the downward fluid velocity exceeds the critical velocity required for upward gas bubble migration, free gas will be forced through the production equipment. For wells producing a water cut greater than 20%, the critical downward fluid velocity is 0.5 ft/sec. For wells producing water cuts less than 20%, the critical fluid velocity is 0.5 ft/sec divided by the fluid viscosity (in centipoise). Therefore, successful gas separation may be achieved by employing gas separators that ensure downward fluid velocities that do not exceed the above critical velocities.

  8. Downhole seismic monitoring with Virtual Sources

    NASA Astrophysics Data System (ADS)

    Bakulin, A.; Calvert, R.

    2005-12-01

    Huge quantities of remaining oil and gas reserves are located in very challenging geological environments covered by salt, basalt or other complex overburdens. Conventional surface seismology struggles to deliver images necessary to economically explore them. Even if those reserves are found by drilling successful production critically depends on our ability to ``see" in real time where fluids are drawn from and how pressure changes throughout the reservoirs. For relatively simple overburdens surface time-lapse (4D) seismic monitoring became industry choice for aerial reservoir surveillance. For complex overburdens, 4D seismic does not have enough resolution and repeatability to answer the questions of reservoir engineers. For instance, often reservoir changes are too small to be detected from surface or these changes occur in such pace that all wells will be placed before we can detect them which greatly reduces the economical impact. Two additional challenges are present in real life that further complicate active monitoring: first, near-surface condition do change between the surveys (water level movement, freezing/thawing, tide variations etc) and second, repeating exact same acquisition geometry at the surface is difficult in practice. Both of these things may lead to false 4D response unrelated to reservoir changes. Virtual Source method (VSM) has been recently proposed as a way to eliminate overburden distortions for imaging and monitoring. VSM acknowledges upfront that our data inversion techniques are unable to unravel the details of the complex overburdens to the extent necessary to remove the distortions caused by them. Therefore VSM advocates placing permanent downhole geophones below that most complex overburden while still exciting signals with a surface sources. For instance, first applications include drilling instrumented wells below complicated near-surface, basalt or salt layer. Of course, in an ideal world we would prefer to have both downhole

  9. Inner Voltage Clamping

    PubMed Central

    Feldberg, Stephen W.; Delgado, Alicia B.

    1978-01-01

    Ketterer, et al. (1971) have suggested that a combination of electrostatic and chemical interactions may cause hydrophobic ions absorbed within a bilayer lipid membrane to reside in two potential wells, each close to a membrane surface. The resulting two planes of charges would define three regions of membrane dielectric: two identical outer regions each between a plane of absorbed charges and the plane of closest approach of ions in the aqueous phase; and the inner region between the two planes of adsorbed charges. The theory describing charge translocation across the inner region is based on a simple three-capacitor model. A significant theoretical conclusion is that the difference between the voltage across the inner region, Vi, and the voltage across the entire membrane, Vm, is directly proportional to the amount of charge that has flowed in a voltage clamp experiment. We demonstrate that we can construct an “inner voltage clamp” that can maintain, with positive feedback, a constant inner voltage, Vi. The manifestation of proper feedback is that the clamp current (after a voltage step) will exhibit pure (i.e., single time-constant) exponential decay, because the voltage dependent rate constants governing translocation will be independent of time. The “pureness” of the exponential is maximized when the standard deviation of the least-square fit of the appropriate exponential equation to the experimental data is minimized. The concomitant feedback is directly related to the capacitances of the inner and outer membrane regions, Ci and Co. Experimental results with tetraphenylborate ion adsorbed in bacterial phosphatidylethanolamine/n-decane bilayers indicate Ci ∼ 5 · 10-7F/cm2 and Co ≈ 5 · 10-5F/cm2. PMID:620078

  10. Down-hole periodic seismic generator

    DOEpatents

    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.

  11. Multipurpose Acoustic Sensor for Downhole Fluid Monitoring

    SciTech Connect

    Pantea, Cristian

    2012-05-04

    The projects objectives and purpose are to: (1) development a multipurpose acoustic sensor for downhole fluid monitoring in Enhanced Geothermal Systems (EGS) reservoirs over typical ranges of pressures and temperatures and demonstrate its capabilities and performance for different EGS systems; (2) determine in real-time and in a single sensor package several parameters - temperature, pressure, fluid flow and fluid properties; (3) needed in nearly every phase of an EGS project, including Testing of Injection and Production Wells, Reservoir Validation, Inter-well Connectivity, Reservoir Scale Up and Reservoir Sustainability. (4) Current sensors are limited to operating at lower temperatures, but the need is for logging at high temperatures. The present project deals with the development of a novel acoustic-based sensor that can work at temperatures up to 374 C, in inhospitable environments.

  12. Development of an Innovative Downhole Seismic Source

    NASA Astrophysics Data System (ADS)

    Reichhardt, D.

    2005-05-01

    MSE Technology Applications, Inc. (MSE) previously designed, built, and tested an innovative downhole seismic source. The design criteria included a size limitation (the source needed to fit into a 2-inch diameter well casing), the source would use .22 caliber power loads as the energy source, it would have the ability to fire at least 12 times before reloading, it would be able to function under water (depth is limited by internal pressure from the .22 caliber power loads, which must be greater than pressure exerted by water column), and it would use no more than 24-volt dc current. MSE developed the design criteria from a need for a downhole seismic source suitable for high-resolution seismic tomography applications. Tomographic methods may provide detailed information at waste sites for both characterization and monitoring. Since borehole diameters are kept to a minimum (i.e., 2-inches or less) to reduce waste volumes from drill cuttings, or the borehole may be installed using a direct push technology such as a GeoprobeT or cone penetrometer, a small diameter source is desirable. Additionally, the use of .22 caliber power loads reduces the amount of supporting equipment required to operate the source as compared to other downhole seismic sources (e.g., air guns and piezoelectric sources). MSE tested and evaluated the completed seismic source to assess the effectiveness of the .22 caliber power loads as energy sources and to assess the operational ease of using the source. Results of the testing indicated that the power loads provided energy suitable for high-resolution cross-well seismic tomography applications. Operation of the source required significantly less supporting equipment than other downhole sources tested. However, the testing suggested the system could be improved if the number of mechanical components were reduced. Subsequent research suggested that the power loads could be fired using an electric current. As a result, MSE believes that the entire

  13. Signal connection for a downhole tool string

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Bradford, Kline; Fox, Joe; Briscoe, Michael

    2006-08-29

    A signal transmission connection for a tool string used in exploration and production of natural resources, namely: oil, gas, and geothermal energy resources. The connection comprises first and second annular elements deployed in cooperative association with each other. The respective elements comprise inductive transducers that are capable of two-way signal transmission between each other, with downhole components of the tool string, and with ground-level equipment. The respective inductive transducers comprise one or more conductive loops housed within ferrite troughs, or within ferrite trough segments. When energized, the conductive loops produce a magnetic field suitable for transmitting the signal. The second element may be rotational in drilling applications. The respective elements may be fitted with electronic equipment to aid and manipulate the transmission of the signal. The first element may also be in communication with the World Wide Web.

  14. Reciprocating down-hole sand pump

    SciTech Connect

    Ruhle, J.L.

    1987-04-28

    This patent describes the invention of a continuously-operated reciprocating down-hole sand pump comprising: a steel polished plunger pipe that strokes back and forth within a steel honed pump barrel, and is equipped with a self-lubricating fluorocarbon V-ring system that is pressure-actuated during compression strokes; the self-lubricating fluorocarbon V-ring system also is self-actuated by means of coil springs to provide wiping action to the polished plunger pipe during suction strokes; the self-lubricating fluorocarbons V-ring system also self-adjusts by means of coil springs located adjacent the fluorocarbon V-ring so as to automatically compensate for V-ring wear; and the self-lubricating fluorocarbon V-ring system also is designed in such a manner so as to eliminate voids and discourage the extrusion of V-rings in high temperature and high-pressure applications.

  15. Saddle Clamp With Captive Components

    NASA Technical Reports Server (NTRS)

    Belrose, Charles R.

    1993-01-01

    Saddle clamp modified to prevent parts from falling off when installed or removed. Allows easy access for tightening or loosening bolts, and retains alignment with tube mounted in it when opened. All parts are held captive - bolts by retaining washers, floating nuts by pressing and swaging, and upper clamp band by tether. Upper and lower bolt flanges offset from each other to ensure access.

  16. Description of a high temperature downhole fluid sampler

    SciTech Connect

    Solbau, R.; Weres, O.; Hansen, L.; Dudak, B.

    1986-05-01

    Downhole fluid samplers have been used for years with limited success in high temperature geothermal wells. This paper discusses the development and operating principles of a high temperature downhole fluid sampler, reliable at obtaining samples at temperatures of up to 350/sup 0/C. The sampler was used successfully for recovering a brine sample from a depth of 10,200 ft in the Salton Sea Scientific Drilling Project well.

  17. Timing of cord clamping revisited.

    PubMed

    Levy, Tali; Blickstein, Isaac

    2006-01-01

    Although cord cutting has been performed since the beginning of mankind, the timing and advantages of early versus delayed cord clamping are still controversial. Early cord clamping (within the first 30 s after birth) is usually justified for potential prevention of postpartum hemorrhage and for immediate treatment of the newborn, but at the same time, may increase Rh-sensitization. Delayed cord clamping is performed after a period of 30 s during which 'placental transfusion' of approximately 80 mL of blood occurs. This amount seems to protect the baby from childhood anemia without increasing hypervolemia-related risks. In preterm infants, delayed clamping appears to reduce the risk of intraventricular hemorrhage and the need for neonatal transfusion. Obtaining cord blood for future autologous transplantation of stem cells needs early clamping and seems to conflict with the infant's best interest. Although a tailored approach is required in the case of cord clamping, the balance of available data suggests that delayed cord clamping should be the method of choice.

  18. Internal V-Band Clamp

    DOEpatents

    Vaughn, Mark R.; Hafenrichter, Everett S.; Chapa, Agapito C.; Harris, Steven M.; Martinez, Marcus J.; Baty, Roy S.

    2006-02-28

    A system for clamping two tubular members together in an end-to-end relationship uses a split ring with a V-shaped outer rim that can engage a clamping surface on each member. The split ring has a relaxed closed state where the ends of the ring are adjacent and the outside diameter of the split ring is less than the minimum inside diameter of the members at their ends. The members are clamped when the split ring is spread into an elastically stretched position where the ring rim is pressed tightly against the interior surfaces of the members. Mechanisms are provided for removing the spreader so the split ring will return to the relaxed state, releasing the clamped members.

  19. Management of umbilical cord clamping.

    PubMed

    Webbon, Lucy

    2013-02-01

    The Royal College of Midwives (RCM) has updated its third stage of labour guidelines (RCM 2012) to be clearly supportive of a delay in umbilical cord clamping, although specific guidance on timing is yet to be announced. It is therefore imperative that both midwives and student midwives understand and are able to integrate delaying into their practice, as well as communicating to women the benefits; only in this way can we give women fully informed choices on this aspect of care. The main benefit of delayed cord clamping is the protection it can provide in reducing childhood anaemia, which is a major issue, especially in poorer countries. A review of the evidence found no risks linked to delayed clamping, and no evidence that it cannot be used in combination with the administration of uterotonic drugs. Delayed cord clamping can be especially beneficial for pre term and compromised babies.

  20. Sound speed in downhole flow measurement.

    PubMed

    Ünalmis, Ö Haldun

    2016-07-01

    This paper describes the use of sound speed in flow measurement applications in the high-pressure/high-temperature downhole environment. The propagation speed of a sound wave is a powerful tool to extract useful information from a flowing fluid medium in pipe whether the medium consists of a single-phase or multiphase flow. Considering the complex nature of the flow patterns and changing phase fractions from reservoir to surface, utilizing the propagation speed of sound of a fluid mixture is not a trivial task, especially if the interest is real-time flow measurement. The demanding applications span a wide spectrum from noisy medium originating from fast-moving gas/liquid flows to quiet medium originating from slow-moving liquid/liquid flows. In the current work, multiple flow loop tests are conducted in different facilities to evaluate the direct use of sound speed in flow rate measurement and the results are associated with real-life field examples. A tool analysis map is developed that addresses the use of sound speed for flow measurement under different scenarios. Although most examples are based on strain-based local sensing of the flow, the use of sound speed is independent of the methodology and can be implemented by other methods such as acoustic-based distributed sensing.

  1. Hydraulically operated downhole oil well pump

    SciTech Connect

    Becker, J.A.

    1983-06-07

    A hydraulically operated downhole pump that is connected to or disposed in a string of tubing, and when operated by pressurized oil from the ground surface, is capable of discharging production fluid, gas, and pressurized oil from the well either separately or in desired combinations thereof. The pump includes an elongate housing preferably of such transverse cross section as to be longitudinally movable through a tubing string, with the pump including universal joint connected upper and lower helical screws that rotate in slidable sealing contact with upper and lower double threaded resilient stator blocks secured to the interior of the housing. As pressurized oil is discharged into the upper end of the housing the upper helical screw and associated stator act as a motor to drive the lower helical screw relative to the lower stator block. As the lower helical screw rotates relative to the lower stator block, the lower helical screw acts as a pump to discharge production fluid from the well upwardly therein either separately or in combination with the pressurized oil depending on the components associated with the pump.

  2. Continuous chain bit with downhole cycling capability

    DOEpatents

    Ritter, Don F.; St. Clair, Jack A.; Togami, Henry K.

    1983-01-01

    A continuous chain bit for hard rock drilling is capable of downhole cycling. A drill head assembly moves axially relative to a support body while the chain on the head assembly is held in position so that the bodily movement of the chain cycles the chain to present new composite links for drilling. A pair of spring fingers on opposite sides of the chain hold the chain against movement. The chain is held in tension by a spring-biased tensioning bar. A head at the working end of the chain supports the working links. The chain is centered by a reversing pawl and piston actuated by the pressure of the drilling mud. Detent pins lock the head assembly with respect to the support body and are also operated by the drilling mud pressure. A restricted nozzle with a divergent outlet sprays drilling mud into the cavity to remove debris. Indication of the centered position of the chain is provided by noting a low pressure reading indicating proper alignment of drilling mud slots on the links with the corresponding feed branches.

  3. Downhole oil/water separators - What's new?

    SciTech Connect

    Veil, J. A.

    2000-01-12

    The US Department of Energy's (DOE's) National Petroleum Technology Office is interested in new technologies that can bring oil to the surface at a lower cost or with less environment impact. DOE is particularly interested in technologies that can accomplish both of these goals, and downhole oil/water separators (DOWS) seem to achieve that. They have the potential to reduce operating costs while providing a greater degree of environmental protection. DOE learned of the innovative DOWS technology and funded a team from Argonne National Laboratory, CH2M Hill (a private-sector consulting firm), and the Nebraska Oil and Gas Conservation Commission (a state agency) to conduct an independent evaluation of the technical feasibility, economic viability, and regulatory applicability of the DOWS technology. The results of that investigation were published in January 1999 and represent the most complete publicly available reference material on DOWs technology (the full text of the report can be downloaded from Argonne's website at www.ead.anl.gov). Other abbreviated versions of this information have been published during the past year. Last January, in the 1999 Produced Water Seminar, the author provided an overview of the DOWS technology. For the 2000 Produced Water Seminar, the author is providing updated information on DOWS and related technologies. To set the stage for the new information, the next few sections provided a review of previously reported information.

  4. Engine end for a downhole hydraulically actuated pump assembly

    SciTech Connect

    Roeder, G.K.

    1992-04-14

    This patent describes a hydraulically actuated downhole pump assembly for producing a well when power fluid is pumped thereto whereupon produced fluid admixed with spent power fluid is returned therefrom. It comprises: the engine end has an engine piston connected to actuate the pump end; the engine end has an annular outer housing, the annular valve element moves axially between an uphole position and a downhole position respective to the annular housing ; the engine piston moves axially within the annular valve element between an uphole position and a downhole position respective to the engine barrel; flow passageway means connecting the valve element for conducting flow of power fluid to the engine end to provide a force against the engine piston to move the engine piston in an uphole and downhole direction, whereupon the annular valve element is moved between an uphole and downhole position in response to the movement of the engine piston and conducts flow of power fluid to alternate sides of the engine piston to provide a force against the engine piston to reciprocate the engine piston.

  5. Magnetostratigraphy from downhole measurements in ODP holes

    NASA Astrophysics Data System (ADS)

    Williams, T.

    2003-04-01

    Magnetic field strength and magnetic susceptibility were logged with the Geological High-resolution Magnetic Tool (GHMT) on 17 ODP Legs, starting in 1990. The GHMT, consisting of a proton precession magnetometer and a susceptibility tool, is lowered down the open borehole on a wireline cable and takes measurements of the formation in situ. The primary use of the tool is to obtain magnetic polarity stratigraphies. Polarity is determined in the following way. First, the susceptibility log is used to determine the induced magnetization of the sediment. Then, the background field, the field of the metal drill pipe, and the field anomaly of the sediment’s induced magnetization are removed from the measured total field to leave the downhole anomaly of the sediment’s remanent magnetization. If the sediment is magnetized strongly enough to give a clear remanent anomaly, its sign (positive or negative) gives the polarity of the remanent magnetization. A further polarity analysis can be applied, based on the fact that in an interval of normal polarity sediment, the remanent anomaly will correlate with the induced anomaly, whereas in reversed polarity sediment they will anti-correlate. Generally, there is good agreement between the magnetostratigraphy obtained from cores and that obtained from the GHMT: the drill-string overprint that affects the cores does not affect the sediments surrounding the borehole to a significant extent. The absence of an overprint allows the ratio of remanent to induced magnetization (the Koenigsberger ratio) to be calculated for different sediment types. This ratio represents the efficiency of the depositional remanence acquisition process. Averaged over time, fine-grained silty clays have ratios of between 1 and 2, and coarser-grained silts and sands have a ratio of less than 0.5. Reliable GHMT magnetostratigraphies can usually be obtained from reasonably well-magnetized fine-grained sediments.

  6. Downhole Vibration Monitoring and Control System

    SciTech Connect

    Martin E. Cobern

    2007-09-30

    The objective of this program is to develop a system to both monitor the vibration of a bottomhole assembly, and to adjust the properties of an active damper in response to these measured vibrations. The key feature of this system is its use of a magnetorheological fluid (MRF) to allow the damping coefficient to be changed extensively, rapidly and reversibly without the use of mechanical valves, but only by the application of a current. Phase I of this program, which entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype, was completed on May 31, 2004. Much of the effort was devoted to the design and testing of the MRF damper, itself. The principal objectives of Phase II were: more extensive laboratory testing, including the evaluation of different feedback algorithms for control of the damper; design and manufacture of a field prototype system; and, testing of the field prototype in a drilling laboratory. Phase II concluded on January 31, 2006, and a final report was issued. Work on Phase III of the project began during the first quarter, 2006, with the objectives of building precommercial prototypes, testing them in a drilling laboratory and the field; developing and implementing a commercialization plan. All of these have been accomplished. The Downhole Vibration Monitoring & Control System (DVMCS) prototypes have been successfully proven in testing at the TerraTek drilling facility and at the Rocky Mountain Oilfield Test Center (RMOTC.) Based on the results of these tests, we have signed a definitive development and distribution agreement with Smith, and commercial deployment is underway. This current version of the DVMCS monitors and controls axial vibrations. Due to time and budget constraints of this program, it was not possible to complete a system that would also deal with lateral and torsional (stick-slip) vibrations as originally planned; however, this effort is continuing without DOE

  7. INTEGRATED POLARIZATION PROPERTIES OF 3C48, 3C138, 3C147, AND 3C286

    SciTech Connect

    Perley, R. A.; Butler, B. J. E-mail: BButler@nrao.edu

    2013-06-01

    We present the integrated polarization properties of the four compact radio sources 3C48, 3C138, 3C147, and 3C286, from 1 to 50 GHz, over a 30 yr time frame spanning 1982-2012. Using the polarized emission of Mars, we have determined that the position angle of the linearly polarized emission of 3C286 rises from 33 Degree-Sign at 8 GHz to 36 Degree-Sign at 45 GHz. There is no evidence for a change in the position angle over time. Using these values, the position angles of the integrated polarized emission from the other three sources are determined as a function of frequency and time. The fractional polarization of 3C286 is found to be slowly rising, at all frequencies, at a rate of {approx}0.015% yr{sup -1}. The fractional polarizations of 3C48, 3C138, and 3C147 are all slowly variable, with the variations correlated with changes in the total flux densities of these sources.

  8. Split-tapered joint clamping device

    DOEpatents

    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.

  9. Micromachined patch-clamp apparatus

    SciTech Connect

    Okandan, Murat

    2012-12-04

    A micromachined patch-clamp apparatus is disclosed for holding one or more cells and providing electrical, chemical, or mechanical stimulation to the cells during analysis with the patch-clamp technique for studying ion channels in cell membranes. The apparatus formed on a silicon substrate utilizes a lower chamber formed from silicon nitride using surface micromachining and an upper chamber formed from a molded polymer material. An opening in a common wall between the chambers is used to trap and hold a cell for analysis using the patch-clamp technique with sensing electrodes on each side of the cell. Some embodiments of the present invention utilize one or more electrostatic actuators formed on the substrate to provide mechanical stimulation to the cell being analyzed, or to provide information about mechanical movement of the cell in response to electrical or chemical stimulation.

  10. Downhole vacuum cleans up tough fishing, milling jobs

    SciTech Connect

    LaLande, P.; Flanders, B.

    1996-02-01

    A unique tool developed to effect reverse circulation downhole is being used successfully in problem milling and fishing operations where conventional techniques fail to recover junk in the hole. Jointly developed by several major operators in conjunction with Baker Oil Tools, the patented Reverse Circulating Tool (RCT) acts as a downhole vacuum cleaner, catching and retaining debris circulated from the wellbore while allowing fishing, milling and washover operations to continue uninterrupted. As described in several case histories overviewed, the unique vacuuming action efficiently cleans up junk and debris in even the most difficult fishing and milling applications. Downhole operations proceed normally, but without threat of damage from milled debris. Developers hold both mechanical and method patents on the RCT.

  11. RUBBER BEARINGS FOR DOWN-HOLE PUMPS

    SciTech Connect

    Bob Sullivan Mammoth Pacific, L.P.

    2005-09-07

    Synopsis of project activity: 1998--Awarded cost share grant from DOE. 1st Qtr 1999--Developed fail safe lubricating system. 2nd Qtr 1999--Performed first large scale test with nitrile based bearings. It failed due to material swelling. Failure was blamed on improper tolerance. 3rd Qtr 1999--Material tests were performed with autoclaves and exposure tests to Casa Diablo fluids. Testing of Viton materials began. Alternate bearing designs were developed to limit risk of improper tolerances. 4th Qtr 1999--Site testing indicated a chemical attack on the bearing material caused the test failure and not improper bearing tolerance. 1st Qtr 2000--The assistance of Brookhaven National Laboratory was obtained in evaluating the chemical attack. The National Laboratory also began more elaborate laboratory testing on bearing materials. 2nd Qtr 2000--Testing indicated Viton was an inappropriate material due to degradation in Casa Diablo fluid. Testing of EPDM began. 3rd Qtr 2001--EPDM bearings were installed for another large scale test. Bearings failed again due to swelling. Further testing indicated that larger then expected oil concentrations existed in lubricating water geothermal fluid causing bearing failure. 2002-2003--Searched for and tested several materials that would survive in hot salt and oil solutions. Kalrez{reg_sign}, Viton{reg_sign}ETP 500 and Viton{reg_sign}GF were identified as possible candidates. 2003-2005--Kalrez{reg_sign}has shown superior resistance to downhole conditions at Casa Diablo from among the various materials tested. Viton ETP-500 indicated a life expectancy of 13 years and because it is significantly less expensive then Kalrez{reg_sign}, it was selected as the bearing material for future testing. Unfortunately during the laboratory testing period Dupont Chemical chose to stop manufacturing this specific formulation and replaced it with Viton ETP 600S. The material is available with six different fillers; three based on zinc oxide and three

  12. Downhole receiver function: A case study

    USGS Publications Warehouse

    Mehta, K.; Snieder, R.; Graizer, V.

    2007-01-01

    Receiver function is defined as the spectral ratio of the radial component and the vertical component of the ground motion. It is used to characterize converted waves. We extend the use of the receiver function to downhole data using waves recorded in a borehole, excited by an earthquake of magnitude 4.0 near San Francisco, California, on 26 June 1994. The focal depth of the event was 6.6 km and the epicenter was located at a distance of 12.6 km from the borehole array. Six three-component sensors were located at different depths in a borehole. To extract a coherent response of the near-surface from the incoherent earthquake waves, we deconvolve the waves recorded by the sensors at different depths with the waves recorded by the sensor on the surface. Deconvolution applied to the waves in the S-time window recorded by the radial component result in an upgoing and a downgoing wave propagating with S-wave velocity. For the waves in the P-time window recorded by the radial component, deconvolution also gives an upgoing and a down-going wave propagating with S-wave velocity. This interesting result suggests a P-to-S conversion at a depth below the deepest sensor. To diagnose this we compute the receiver function for the borehole recording of the earthquake waves. The receiver function shows an upgoing wave with an arrival close to time t = 0 for the deepest sensor. The agreement of the upgoing wave in the receiver function with the travel-time curve for the P-to-S converted wave, calculated using the P- and the S-wave velocity profile, supports the hypothesis of a pronounced P-to-S conversion. We present a synthetic example to illustrate that the first arrival of the receiver function applied to borehole data gives the upward-propagating P-to-S converted wave. To corroborate the observation of the mode conversion, we apply receiver function to a different earthquake data recorded by the same borehole array in 1998. The focal depth of the event was 6.9 km and the

  13. Limit analysis of pipe clamps

    SciTech Connect

    Flanders, H.E. Jr.

    1990-01-01

    The Service Level D (faulted) load capacity of a conventional three-bolt pipe-clamp based upon the limit analysis method is presented. The load distribution, plastic hinge locations, and collapse load are developed for the lower bound limit load method. The results of the limit analysis are compared with the manufacturer's rated loads. 3 refs.

  14. Complement component 3 (C3)

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003539.htm Complement component 3 (C3) To use the sharing features on ... and C4 are the most commonly measured complement components. A complement test may be used to monitor ...

  15. Distributed Temperature Sensing as a downhole tool in hydrogeology

    NASA Astrophysics Data System (ADS)

    Bense, V. F.; Read, T.; Bour, O.; Le Borgne, T.; Coleman, T.; Krause, S.; Chalari, A.; Mondanos, M.; Ciocca, F.; Selker, J. S.

    2016-12-01

    Distributed Temperature Sensing (DTS) technology enables downhole temperature monitoring to study hydrogeological processes at unprecedentedly high frequency and spatial resolution. DTS has been widely applied in passive mode in site investigations of groundwater flow, in-well flow, and subsurface thermal property estimation. However, recent years have seen the further development of the use of DTS in an active mode (A-DTS) for which heat sources are deployed. A suite of recent studies using A-DTS downhole in hydrogeological investigations illustrate the wide range of different approaches and creativity in designing methodologies. The purpose of this review is to outline and discuss the various applications and limitations of DTS in downhole investigations for hydrogeological conditions and aquifer geological properties. To this end, we first review examples where passive DTS has been used to study hydrogeology via downhole applications. Secondly, we discuss and categorize current A-DTS borehole methods into three types. These are thermal advection tests, hybrid cable flow logging, and heat pulse tests. We explore the various options with regards to cable installation, heating approach, duration, and spatial extent in order to improve their applicability in a range of settings. These determine the extent to which each method is sensitive to thermal properties, vertical in-well flow, or natural gradient flow. Our review confirms that the application of DTS has significant advantages over discrete point temperature measurements, particularly in deep wells, and highlights the potential for further method developments in conjunction with other emerging hydrogeophysical tools.

  16. The application and design of downhole heat exchanger

    SciTech Connect

    Freeston, D.H.; Pan, H.

    1985-01-01

    The direct use of low temperature geothermal fluids is finding increased usage around the world for space heating, air conditioning, etc. For non-artesian wells the conventional means of circulating the hot fluids is by a downhole turbine pump, with the geofluid being either returned to the reservoir or rejected to waste. The latter is the more common, with results, in some cases, of excessive drawdown of the reservoir and consequent environmental problems. The downhole heat exchanger, utilising a single or multiple ''U'' tube, can alleviate the above problems. Experience at Klamath Falls in Oregon, U.S.A., and at Rotorua and Taupo, New Zealand, shows that these devices are capable, given a good permeable reservoir with temperatures around 100C, of delivering up to 1 MW of thermal energy from a conventional shallow well (50 to 200 m). This paper discusses the application of the downhole heat exchanger for space heating using examples from New Zealand and Klamath Falls systems, and reports a recent study on the parameters necessary to achieve an optimum design. The discussion is based on a laboratory model, a computer simulation an full-scale tests on operational downhole heat exchangers in New Zealand.

  17. Fallon FORGE GIS and Downhole Well Lithology Data

    SciTech Connect

    Doug Blankenship

    2015-12-23

    ArcGIS Map Package with MT Station Locations, 2D Seismic Lines, Well data, Known Regional Hydrothermal Systems, Regional Historic Earthquake Seismicity, Regional Temperature Gradient Data, Regional Heat Flow Data, Regional Radiogenic Heat Production, Local Geology, Land Status, Cultural Data, 2m Temperature Probe Data, and Gravity Data. Also a detailed down-hole lithology notes are provided.

  18. Corrosion reference for geothermal downhole materials selection: Overview

    SciTech Connect

    Ellis, Peter F.

    1982-10-08

    A consolidated reference of materials for downhole equipment used in geothermal energy exploitation is nearing completion. The reference is a summary of recent developments in the areas of tubular goods materials, highly alloyed metals, high temperature cements, high temperature elastomers, drilling and completion tools, logging tools, and downwell pumps. A brief overview is presented in this paper.

  19. Method and apparatus for detecting orientation of downhole geophones

    SciTech Connect

    Hill, B.; Khalil, H.; Albers, R.

    1992-07-07

    This patent describes a downhole geophone assembly. It comprises at least one geophone; a casing enclosing at least one geophone; means for securing a high frequency electro-magnetic radiation radiating source to the geophone assembly; tubing having an internal surface and an exterior surface; and means for securing the geophone to the exterior surface of the tubing.

  20. Downhole steam generator with improved preheating, combustion, and protection features

    DOEpatents

    Fox, R.L.

    1981-01-07

    For tertiary oil recovery, a downhole steam generator is designed which provides for efficient counterflow cooling of the combustion chamber walls and preheating of the fuel and water. Pressure-responsive doors are provided for closing and opening the outlet in response to flameout, thereby preventing flooding of the combustion chamber. (DLC)

  1. Comparative evaluation of surface and downhole steam-generation techniques

    SciTech Connect

    Hart, C.

    1982-01-01

    It has long been recognized that the application of heat to reservoirs containing high API gravity oils can substantially improve recovery. Although steam injection is currently the principal thermal recovery method, heat transmission losses associated with delivery of the steam from the surface generators to the oil-bearing formation has limited conventional steam injection to shallow reservoirs. The objective of the Department of Energy's Project DEEP STEAM is to develop the technology required to economically produce heavy oil from deep reservoirs. The tasks included in this effort are the development and evaluation of thermally efficient delivery systems and downhole steam generation systems. This paper compares the technical and economic performance of conventional surface steam drives, which are strongly influenced by heat losses, with (a) thermally efficient delivery (through insulated strings) of surface generated steam, (b) low pressure combustion downhole steam generation, (c) high pressure combustion downhole steam generation using air as the oxygen source, and (d) high pressure combustion downhole steam generation substituting pure oxygen for air. The selection of a preferred technology based upon either total efficiency or cost is found to be strongly influenced by reservoir depth, steam mass flow rate, and sandface steam quality. Therefore, a parametric analysis has been performed which examines varying depths, injection rates and steam qualities. Results indicate that the technologies are not readily distinguishable for low injectivity reservoirs in which conventional steam drives are feasible. However, high injection rates produce a notable cost difference between high pressure combustion systems and the other technologies. Issues that must be addressed before gaining further insight into the economic viability of downhole steam generation are discussed.

  2. Is early cord clamping, delayed cord clamping or cord milking best?

    PubMed

    Vatansever, Binay; Demirel, Gamze; Ciler Eren, Elif; Erel, Ozcan; Neselioglu, Salim; Karavar, Hande Nur; Gundogdu, Semra; Ulfer, Gozde; Bahadir, Selcen; Tastekin, Ayhan

    2017-03-20

    To compare the antioxidant status of three cord clamping procedures (early clamping, delayed clamping and milking) by analyzing the thiol-disulfide balance. This randomized controlled study enrolled 189 term infants who were divided into three groups according to the cord clamping procedure: early clamping, delayed clamping and milking. Blood samples were collected from the umbilical arteries immediately after clamping, and the thiol/disulfide homeostasis was analyzed. The native and total thiol levels were significantly (p < .05) lower in the early cord clamping group compared with the other two groups. The disulfide/total thiol ratio was significantly (p = .026) lower in the delayed cord clamping and milking groups compared with the early clamping groups. Early cord clamping causes the production of more disulfide bonds and lower thiol levels, indicating that oxidation reactions are increased in the early cord clamping procedure compared with the delayed cord clamping and milking procedures. The oxidant capacity is greater with early cord clamping than with delayed clamping or cord milking. Delayed cord clamping or milking are beneficial in neonatal care, and we suggest that they be performed routinely in all deliveries.

  3. Delayed umbilical cord clamping in premature neonates.

    PubMed

    Kaempf, Joseph W; Tomlinson, Mark W; Kaempf, Andrew J; Wu, YingXing; Wang, Lian; Tipping, Nicole; Grunkemeier, Gary

    2012-08-01

    Delayed umbilical cord clamping is reported to increase neonatal blood volume. We estimated the clinical outcomes in premature neonates who had delayed umbilical cord clamping compared with a similar group who had early umbilical cord clamping. This was a before-after investigation comparing early umbilical cord clamping with delayed umbilical cord clamping (45 seconds) in two groups of singleton neonates, very low birth weight (VLBW) (401-1,500 g) and low birth weight (LBW) (greater than 1,500 g but less than 35 weeks gestation). Neonates were excluded from delayed umbilical cord clamping if they needed immediate major resuscitation. Primary outcomes were provision of delivery room resuscitation, hematocrit, red cell transfusions, and the principle Vermont Oxford Network outcomes. In VLBW neonates (77 delayed umbilical cord clamping, birth weight [mean±standard deviation] 1,099±266 g; 77 early umbilical cord clamping 1,058±289 g), delayed umbilical cord clamping was associated with less delivery room resuscitation, higher Apgar scores at 1 minute, and higher hematocrit. Delayed umbilical cord clamping was not associated with significant differences in the overall transfusion rate, peak bilirubin, any of the principle Vermont Oxford Network outcomes, or mortality. In LBW neonates (172 delayed umbilical cord clamping, birth weight [mean±standard deviation] 2,159±384 g; 172 early umbilical cord clamping 2,203±447 g), delayed umbilical cord clamping was associated with higher hematocrit and was not associated with a change in delivery room resuscitation or Apgar scores or with changes in the transfusion rate or peak bilirubin. Regression analysis showed increasing gestational age and birth weight and delayed umbilical cord clamping were the best predictors of higher hematocrit and less delivery room resuscitation. Delayed umbilical cord clamping can safely be performed in singleton premature neonates and is associated with a higher hematocrit, less delivery room

  4. The RFC clamp loader: structure and function.

    PubMed

    Yao, Nina Y; O'Donnell, Mike

    2012-01-01

    The eukaryotic RFC clamp loader couples the energy of ATP hydrolysis to open and close the circular PCNA sliding clamp onto primed sites for use by DNA polymerases and repair factors. Structural studies reveal clamp loaders to be heteropentamers. Each subunit contains a region of homology to AAA+ proteins that defines two domains. The AAA+ domains form a right-handed spiral upon binding ATP. This spiral arrangement generates a DNA binding site within the center of RFC. DNA enters the central chamber through a gap between the AAA+ domains of two subunits. Specificity for a primed template junction is achieved by a third domain that blocks DNA, forcing it to bend sharply. Thus only DNA with a flexible joint can bind the central chamber. DNA entry also requires a slot in the PCNA clamp, which is opened upon binding the AAA+ domains of the clamp loader. ATP hydrolysis enables clamp closing and ejection of RFC, completing the clamp loading reaction.

  5. Active cooling for downhole instrumentation: Preliminary analysis and system selection

    SciTech Connect

    Bennett, G.A.

    1988-03-01

    A feasibility study and a series of preliminary designs and analyses were done to identify candidate processes or cycles for use in active cooling systems for downhole electronic instruments. A matrix of energy types and their possible combinations was developed and the energy conversion process for each pari was identified. The feasibility study revealed conventional as well as unconventional processes and possible refrigerants and identified parameters needing further clarifications. A conceptual design or series od oesigns for each system was formulated and a preliminary analysis of each design was completed. The resulting coefficient of performance for each system was compared with the Carnot COP and all systems were ranked by decreasing COP. The system showing the best combination of COP, exchangeability to other operating conditions, failure mode, and system serviceability is chosen for use as a downhole refrigerator. 85 refs., 48 figs., 33 tabs.

  6. From overshoot to voltage clamp.

    PubMed

    Huxley, Andrew

    2002-11-01

    In 1939, A.L. Hodgkin and I found that the nerve action potential shows an "overshoot"--that is, the interior of the fibre becomes electrically positive during an action potential. In 1948, we did our first experiments with a voltage clamp to investigate the current-voltage relations of the nerve membrane. Between those dates, we spent much time speculating about the mechanism by which ions cross the membrane and how the action potential is generated. This article summarizes these speculations, none of which has been previously published.

  7. Apparatus and method for downhole injection of radioactive tracer

    DOEpatents

    Potter, Robert M.; Archuleta, Jacobo R.; Fink, Conrad F.

    1983-01-01

    The disclosure relates to downhole injection of radioactive .sup.82 Br and monitoring its progress through fractured structure to determine the nature thereof. An ampule containing granular .sup.82 Br is remotely crushed and water is repeatedly flushed through it to cleanse the instrument as well as inject the .sup.82 Br into surrounding fractured strata. A sensor in a remote borehole reads progress of the radioactive material through fractured structure.

  8. Apparatus and method for downhole injection of radioactive tracer

    DOEpatents

    Potter, R.M.; Archuleta, J.; Fink, C.F.

    The disclosure relates to downhole injection of radioactive /sup 82/Br and monitoring its progress through fractured structure to determine the nature thereof. An ampule containing granular /sup 82/Br is remotely crushed and water is repeatedly flushed through it to cleanse the instrument as well as inject the /sup 82/Br into surrounding fractured strata. A sensor in a remote horehole reads progress of the radioactive material through fractured structure.

  9. High power laser downhole cutting tools and systems

    DOEpatents

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2015-01-20

    Downhole cutting systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser cutting operations within a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform cutting operations in such boreholes deep within the earth.

  10. Fate of hydraulic fracturing chemicals under down-hole conditions

    NASA Astrophysics Data System (ADS)

    Blotevogel, J.; Kahrilas, G.; Corrin, E. R.; Borch, T.

    2013-12-01

    Hydraulic fracturing is a method to increase the yield of oil and natural gas extraction from unconventional rock formations. The process of hydrofracturing occurs via injecting water, sand, and chemicals into the production well and subjecting this mixture to high pressures to crack the rock shale, allowing increased amounts of gas and oil to seep out of the target formation. Typical constituents of the chemical mixtures are biocides, which are applied to inhibit growth of sulfate reducing bacteria in order to prevent pipe corrosion and production of hazardous gases. However, very little is known about the persistence, fate, and activity of biocides when subjected to the high temperatures and pressures of down-hole conditions. Thus, the objective of this talk is to present data from ongoing experiments focused on determining the fate of biocides commonly used for hydraulic fracturing under conditions simulating down-hole environments. Using stainless steel reactors, the high pressures and temperatures of down-hole conditions in the Marcellus shale are simulated, while concentration, speciation, and degradation of priority biocides are observed as a function of time, using primarily LC/MS techniques. The impact of water quality, shale, temperature, and pressure on the transformation kinetics and pathways of biocides will be discussed. Finally, field samples (both sediments and flowback brine) from the Marcellus shale are analyzed to verify that our lab simulations mirror real-life conditions and results.

  11. Prediction of the combustion characteristics in a downhole steam generator

    SciTech Connect

    Naugler, David G.; Mohtadi, M. F.

    1984-02-01

    Downhole steam generation is an attractive alternative to conventional surface steam generation for recovery of heavy oils from deep reservoirs. Downhole steam generation technique has been under development in the past five years in the United States, Canada and the United Kingdom. The main advantages of this method are very high thermal efficiency, flexibility of operation and lower environmental pollution load. In conjunction with experimental work on the development of a downhole steam generator at the University of Calgary, two computer models for prediction of the combustion characteristics in such generators have been developed. The first model is based on the assumption of a balanced reaction and complete combustion of the fuel. It determines the reaction temperature and the enthalpy of the product gases at different pressures, air/fuel ratios and water injection rates. The second model uses a modified version of the Dixon Lewis method to determine equilibrium for all species of the reaction system, including nitrogen oxides. A non-Jacobian numerical method is used for the solution of the resulting system of non-linear equations. The results show that to a fairly good approximation, the reaction temperature and the composition of product gases may be correlated with the main operating variables by simple logarithmic plots. This facilitates extrapolation of the experimental data by the use of allocation transformations.

  12. System for loading executable code into volatile memory in a downhole tool

    DOEpatents

    Hall, David R.; Bartholomew, David B.; Johnson, Monte L.

    2007-09-25

    A system for loading an executable code into volatile memory in a downhole tool string component comprises a surface control unit comprising executable code. An integrated downhole network comprises data transmission elements in communication with the surface control unit and the volatile memory. The executable code, stored in the surface control unit, is not permanently stored in the downhole tool string component. In a preferred embodiment of the present invention, the downhole tool string component comprises boot memory. In another embodiment, the executable code is an operating system executable code. Preferably, the volatile memory comprises random access memory (RAM). A method for loading executable code to volatile memory in a downhole tool string component comprises sending the code from the surface control unit to a processor in the downhole tool string component over the network. A central processing unit writes the executable code in the volatile memory.

  13. High-speed pressure clamp.

    PubMed

    Besch, Stephen R; Suchyna, Thomas; Sachs, Frederick

    2002-10-01

    We built a high-speed, pneumatic pressure clamp to stimulate patch-clamped membranes mechanically. The key control element is a newly designed differential valve that uses a single, nickel-plated piezoelectric bending element to control both pressure and vacuum. To minimize response time, the valve body was designed with minimum dead volume. The result is improved response time and stability with a threefold decrease in actuation latency. Tight valve clearances minimize the steady-state air flow, permitting us to use small resonant-piston pumps to supply pressure and vacuum. To protect the valve from water contamination in the event of a broken pipette, an optical sensor detects water entering the valve and increases pressure rapidly to clear the system. The open-loop time constant for pressure is 2.5 ms for a 100-mmHg step, and the closed-loop settling time is 500-600 micros. Valve actuation latency is 120 micros. The system performance is illustrated for mechanically induced changes in patch capacitance.

  14. Comparative analysis of steam delivery cost for surface and downhole steam drive technologies

    SciTech Connect

    Hart, C.M.

    1981-10-01

    A basis is established for evaluating the economic performances of the technologies for enhanced recovery of heavy crude being investigated through the Department of Energy's Project DEEP STEAM. Conventional surface steam drive is compared with: (1) thermally efficient delivery (through insulated strings) of surface generated steam; (2) low pressure combustion downhole steam generation; (3) high pressure combustion downhole steam generation; (4) high pressure combustion downhole steam generation using air as the oxygen source; and (5) high pressure combustion downhole steam generation substituting pure oxygen for air. A parametric analysis is performed for varying depths, injection rates, and steam qualities.

  15. [A clamp for suturing of duodenal stump].

    PubMed

    Komarov, I A

    1991-03-01

    An original clamp was used in suturing a duodenal stump after gastric resection in 77 patients. The complex relief of the blades of the clamp holds the duodenum reliably during application of the sutures and ensures their air-tightness. The trauma inflicted to the duodenum in this case is minimal. During resection of the stomach in 37 patients the author used the clamp in closure of the lesser curvature. Incompetence of the duodenal stump was not encountered.

  16. Advanced motor driven clamped borehole seismic receiver

    DOEpatents

    Engler, Bruce P.; Sleefe, Gerard E.; Striker, Richard P.

    1993-01-01

    A borehole seismic tool including a borehole clamp which only moves perpendicular to the borehole. The clamp is driven by an electric motor, via a right angle drive. When used as a seismic receiver, the tool has a three part housing, two of which are hermetically sealed. Accelerometers or geophones are mounted in one hermetically sealed part, the electric meter in the other hermetically sealed part, and the clamp and right angle drive in the third part. Preferably the tool includes cable connectors at both ends. Optionally a shear plate can be added to the clamp to extend the range of the tool.

  17. Advanced motor driven clamped borehole seismic receiver

    DOEpatents

    Engler, B.P.; Sleefe, G.E.; Striker, R.P.

    1993-02-23

    A borehole seismic tool is described including a borehole clamp which only moves perpendicular to the borehole. The clamp is driven by an electric motor, via a right angle drive. When used as a seismic receiver, the tool has a three part housing, two of which are hermetically sealed. Accelerometers or geophones are mounted in one hermetically sealed part, the electric motor in the other hermetically sealed part, and the clamp and right angle drive in the third part. Preferably the tool includes cable connectors at both ends. Optionally a shear plate can be added to the clamp to extend the range of the tool.

  18. 21 CFR 870.4450 - Vascular clamp.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vascular clamp. 870.4450 Section 870.4450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Surgical Devices § 870.4450 Vascular clamp. (a) Identification. A vascular...

  19. Working member of a helical downhole motor for drilling wells

    SciTech Connect

    Kochnev, A.M.; Vshivkov, A.N.; Goldobin, V.B.

    1993-06-22

    A working member of a helical downhole motor is described for drilling wells comprising: separate tubular sections having helical teeth arranged in succession and interconnected by connecting elements, each connecting element having the form of a ring, rigidly secured at the tubular sections and having helical teeth of a pitch and a direction equal to a pitch and a direction, respectively, of the helical teeth of the tubular sections, whereas a profile of the helical teeth of the ring is equidistant to a profile of the helical teeth of the sections.

  20. Steam drive recovery method utilizing a downhole steam generator

    SciTech Connect

    Snavely, E. S.; Hopkins, D. N.

    1984-09-18

    Viscous oil is recovered from a subterranean, viscous oil-containing formation by a steam flooding technique wherein steam is generated in a downhole steam generator located in an injection well by spontaneous combustion of a pressurized mixture of a water-soluble fuel such as sugars and alcohols dissolved in water and substantially pure oxygen. The generated mixture of steam and combustion gases pass through the formation, displacing oil and reducing the oil's viscosity and the mobilized oil is produced from the formation via a spaced-apart production well.

  1. Steam drive oil recovery method utilizing a downhole steam generator

    SciTech Connect

    Nopkins, D. N.; Snavely, E. S.

    1984-10-23

    Viscous oil is recovered from a subterranean, viscous oil-containing formation by a steam flooding technique wherein steam is generated in a downhole steam generator located in an injection well by spontaneous combustion of a pressurized mixture of a water-soluble fuel such as sugars and alcohols dissolved in water or a stable hydrocarbon fuel-in-water emulsion and substantially pure oxygen. The generated mixture of steam and combustion gases pass through the formation, displacing oil and reducing the oil's viscosity and the mobilized oil is produced from the formation via a spaced-apart production well.

  2. Downhole tools can increase deep drilling rig productivity

    SciTech Connect

    Thiessen, D.A.; Doiron, H.H.

    1983-01-01

    Explains how there is much to be gained by better utilization of current drilling equipment, particularly for the much more expensive deep drilling. Optimized mud weight, better hydraulics, and higher rpm offer the best opportunities with increased bit weight as a fourth possibility. Current RandD in such areas as shock absorbers, downhole motors, new materials and designs for bits, and improved instrumentation will decrease drilling costs. Concludes that a reasonable projection is that drilling time for deep wells can be halved within the next decade.

  3. A mathematical model for the downhole orbital vibrator source

    SciTech Connect

    Dong, W.

    1994-12-31

    An analytical expression for the downhole orbital vibrator source is proposed by approximating the source as rotating radial forces applied to the borehole wall. Decomposition of this expression indicates that the source is equivalent to the sum of four imaginary non-rotational sources. These imaginary sources, in conjunction with Green`s functions, provide a direct way of generating synthetic seismograms. They are used in this paper to obtain the displacement in homogeneous isotropic and transversely isotropic (TI) media. Evaluation of the displacement suggests that the source would be useful in detecting shear wave anisotropy by crosshole experiments.

  4. Inductive coupler for downhole components and method for making same

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Dahlgren, Scott; Sneddon, Cameron; Fox, Joe; Briscoe, Michael A.

    2006-10-03

    An inductive coupler for downhole components. The inductive coupler includes an annular housing having a recess defined by a bottom portion and two opposing side wall portions. At least one side wall portion includes a lip extending toward but not reaching the other side wall portion. A plurality of generally U-shaped MCEI segments, preferably comprised of ferrite, are disposed in the recess and aligned so as to form a circular trough. The coupler further includes a conductor disposed within the circular trough and a polymer filling spaces between the segments, the annular housing and the conductor.

  5. Time to implement delayed cord clamping.

    PubMed

    McAdams, Ryan M

    2014-03-01

    Immediate umbilical cord clamping after delivery is routine in the United States despite little evidence to support this practice. Numerous trials in both term and preterm neonates have demonstrated the safety and benefit of delayed cord clamping. In premature neonates, delayed cord clamping has been shown to stabilize transitional circulation, lessening needs for inotropic medications and reducing blood transfusions, necrotizing enterocolitis, and intraventricular hemorrhage. In term neonates, delayed cord clamping has been associated with decreased iron-deficient anemia and increased iron stores with potential valuable effects that extend beyond the newborn period, including improvements in long-term neurodevelopment. The failure to more broadly implement delayed cord clamping in neonates ignores published benefits of increased placental blood transfusion at birth and may represent an unnecessary harm for vulnerable neonates.

  6. Combat ready clamp medic technique.

    PubMed

    Tovmassian, Robert V; Kragh, John F; Dubick, Michael A; Baer, David G; Blackbourne, Lorne H

    2012-01-01

    Junctional hemorrhage control device use on the battlefield might be lifesaving, but little experience is reported. The purpose of the present case report is to detail prehospital use of the Combat Ready Clamp (called the CRoC by its users, Combat Medical Systems, Fayetteville, NC; Instructions for Use, 2010) in casualty care in order to increase awareness of junctional hemorrhage control. The CRoC was used to control difficult inguinal bleeding on the battlefield for an Afghani man with a hindquarter traumatic amputation. The device promptly controlled exsanguination from a critical injury when placed during rotary-wing casualty evacuation. The flight medic applied the device in 90 seconds. The device performed well without complications to control bleeding. The CRoC, a new junctional hemorrhage control device, was used as indicated on the battlefield with mechanical and physiologic success and without device problems. By controlling difficult inguinal bleeding resulting from battlefield trauma, the device facilitated casualty stabilization and delivery to a surgical facility. The device facilitated the ability of a new flight medic to focus his expertise on a critically injured battlefield casualty with demonstrable success. 2012.

  7. Interest revives in downhole oil-water separators.

    SciTech Connect

    Veil, J. A.; Environmental Assessment

    2001-02-26

    As oil prices have increased, interest in downhole oil-water separators (DOWS) has returned after a 2-year lull caused by a low oil price and the nervousness of operators to install relatively unproven technology, which in many trials had proven uneconomical. DOWS technology aims to reduce produced water at the surface by separating it from oil downhole and simultaneously injecting it underground. The technology holds great promise for reducing produced-water disposal costs and protecting potable-water aquifers. It has, in some instances, increased oil production from wells in which it has been installed. During the last 2 years, some DOWS vendors have ceased actively marketing their DOWS technology for the time being. On the other hand, oil companies around the world are again seriously considering ordering or testing DOWS technology in 2001. The first offshore installation of a DOWS took place off China during 2000. Other offshore trials may follow this year. Several new variations on DOWS and remote separation systems offer potential for different market segments, and 2001 should be a more promising year for DOWS.

  8. DOWNHOLE POWER GENERATION AND WIRELESS COMMUNICATIONS FOR INTELLIGENT COMPLETIONS APPLICATIONS

    SciTech Connect

    Paul Tubel

    2003-07-05

    The third quarter of the project was dedicated to creating the detailed design for the manufacturing of the mechanical system for wireless communications and the power generation module. Another emphasis for the quarter was the development of the surface system and acoustic detector for the downhole tool for 2 way communications. The tasks accomplished during this report period were: (1) All detailed drawings for manufacturing of the wireless communications gauge and power generator were completed and the drawings were forward to a machine shop for manufacturing. (2) The power generator was incorporated to the mandrel of the wireless gauge reducing the length of the tool by 25% and manufacturing cost by about 35%. (3) The new piezoelectric acoustic generator was manufactured successfully and it was delivered during this quarter. The assembly provides a new technique to manufacture large diameter piezoelectric based acoustic generators. (4) The acoustic two-way communications development progressed significantly. The real time firmware for the surface system was developed and the processor was able to detect and process the data frame transmitted from downhole. The analog section of the tool was also developed and it is being tested for filtering capabilities and signal detection and amplification. (5) The new transformer to drive the piezoelectric wafer assembly was designed and manufactured. The transformer has been received and it will go through testing and evaluation during the next quarter.

  9. DOWNHOLE POWER GENERATION AND WIRELESS COMMUNICATIONS FOR INTELLIGENT COMPLETIONS APPLICATIONS

    SciTech Connect

    Paul Tubel

    2003-03-24

    The first quarter of the Downhole Power Generation and Wireless Communications for Intelligent Completions Applications was characterized by the evaluation and determination of the specifications required for the development of the system for permanent applications in wellbores to the optimization of hydrocarbon production. The system will monitor and transmit in real time pressure and temperature information from downhole using the production tubing as the medium for the transmission of the acoustic waves carrying digital information. The most common casing and tubing sizes were determined by interfacing with the major oil companies to obtain information related to their wells. The conceptual design was created for both the wireless gauge section of the tool as well as the power generation module. All hardware for the wireless gauge will be placed in an atmospheric pressure chamber located on the outside of a production tubing with 11.4 centimeter (4-1/2 inch) diameter. This mounting technique will reduce cost as well as the diameter and length of the tool and increase the reliability of the system. The power generator will use piezoelectric wafers to generate electricity based on the flow of hydrocarbons through an area in the wellbore where the tool will be deployed. The goal of the project is to create 1 Watt of power continuously.

  10. An optical study of 3C 31, 3C 66B, 3C 120, and their jets

    SciTech Connect

    Fraix-burnet, D.; Golombek, D.; Macchetto, F.D. Space Telescope Science Institute, Baltimore, MD )

    1991-08-01

    The paper presents the results of BVRI CCD photometry of the radio galaxies 3C 31, 3C 66B, and 3C 120, and V polarimetry of 3C 120. The photometry of the jet of 3C 66B definitively establishes the synchrotron nature of the optical emission. No optical counterpart of the radio counterjet in 3C 66B and of the radio jets in 3C 31 and 3C 120 is found. A rotating ring and an ionized region are present, respectively, in 3C 31 (NGC 383) and its companion galaxy NGC 382, but no isophotal distortions are found which could have revealed a gravitational interaction between the two galaxies as is the case in 3C 66B. The elliptical isophotes of 3C 120 show a slight off-centering, roughly in the direction of the radio jet, very much like 3C 66B. An upper limit of 20 percent is found for the polarization level of the condensations in 3C 120. 50 refs.

  11. The monogenean which lost its clamps.

    PubMed

    Justine, Jean-Lou; Rahmouni, Chahrazed; Gey, Delphine; Schoelinck, Charlotte; Hoberg, Eric P

    2013-01-01

    Ectoparasites face a daily challenge: to remain attached to their hosts. Polyopisthocotylean monogeneans usually attach to the surface of fish gills using highly specialized structures, the sclerotized clamps. In the original description of the protomicrocotylid species Lethacotyle fijiensis, described 60 years ago, the clamps were considered to be absent but few specimens were available and this observation was later questioned. In addition, genera within the family Protomicrocotylidae have either clamps of the "gastrocotylid" or the "microcotylid" types; this puzzled systematists because these clamp types are characteristic of distinct, major groups. Discovery of another, new, species of the genus Lethacotyle, has allowed us to explore the nature of the attachment structures in protomicrocotylids. Lethacotyle vera n. sp. is described from the gills of the carangid Caranx papuensis off New Caledonia. It is distinguished from Lethacotyle fijiensis, the only other species of the genus, by the length of the male copulatory spines. Sequences of 28S rDNA were used to build a tree, in which Lethacotyle vera grouped with other protomicrocotylids. The identity of the host fish was confirmed with COI barcodes. We observed that protomicrocotylids have specialized structures associated with their attachment organ, such as lateral flaps and transverse striations, which are not known in other monogeneans. We thus hypothesized that the clamps in protomicrocotylids were sequentially lost during evolution, coinciding with the development of other attachment structures. To test the hypothesis, we calculated the surfaces of clamps and body in 120 species of gastrocotylinean monogeneans, based on published descriptions. The ratio of clamp surface: body surface was the lowest in protomicrocotylids. We conclude that clamps in protomicrocotylids are vestigial organs, and that occurrence of "gastrocotylid" and simpler "microcotylid" clamps within the same family are steps in an

  12. The Monogenean Which Lost Its Clamps

    PubMed Central

    Justine, Jean-Lou; Rahmouni, Chahrazed; Gey, Delphine; Schoelinck, Charlotte; Hoberg, Eric P.

    2013-01-01

    Ectoparasites face a daily challenge: to remain attached to their hosts. Polyopisthocotylean monogeneans usually attach to the surface of fish gills using highly specialized structures, the sclerotized clamps. In the original description of the protomicrocotylid species Lethacotyle fijiensis, described 60 years ago, the clamps were considered to be absent but few specimens were available and this observation was later questioned. In addition, genera within the family Protomicrocotylidae have either clamps of the “gastrocotylid” or the “microcotylid” types; this puzzled systematists because these clamp types are characteristic of distinct, major groups. Discovery of another, new, species of the genus Lethacotyle, has allowed us to explore the nature of the attachment structures in protomicrocotylids. Lethacotyle vera n. sp. is described from the gills of the carangid Caranx papuensis off New Caledonia. It is distinguished from Lethacotyle fijiensis, the only other species of the genus, by the length of the male copulatory spines. Sequences of 28S rDNA were used to build a tree, in which Lethacotyle vera grouped with other protomicrocotylids. The identity of the host fish was confirmed with COI barcodes. We observed that protomicrocotylids have specialized structures associated with their attachment organ, such as lateral flaps and transverse striations, which are not known in other monogeneans. We thus hypothesized that the clamps in protomicrocotylids were sequentially lost during evolution, coinciding with the development of other attachment structures. To test the hypothesis, we calculated the surfaces of clamps and body in 120 species of gastrocotylinean monogeneans, based on published descriptions. The ratio of clamp surface: body surface was the lowest in protomicrocotylids. We conclude that clamps in protomicrocotylids are vestigial organs, and that occurrence of “gastrocotylid” and simpler “microcotylid” clamps within the same family are

  13. Surface characterization of selected LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Cromer, T. F.; Grammer, H. L.; Wightman, J. P.; Young, Philip R.; Slemp, Wayne S.

    1993-01-01

    The surface characterization of chromic acid anodized 6061-T6 aluminum alloy tray clamps has shown differences in surface chemistry depending upon the position on the Long Duration Exposure Facility (LDEF). Water contact angle results showed no changes in wettability of the tray clamps. The overall surface topography of the control, trailing edge(E3) and leading edge(D9) samples was similar. The thickness of the aluminum oxide layer for all samples determined by Auger depth profiling was less than one micron. X-ray photoelectron spectroscopy (XPS) analysis of the tray clamps showed significant differences in the surface composition. Carbon and silicon containing compounds were the primary contaminants detected.

  14. Dynamic clamp with StdpC software.

    PubMed

    Kemenes, Ildikó; Marra, Vincenzo; Crossley, Michael; Samu, Dávid; Staras, Kevin; Kemenes, György; Nowotny, Thomas

    2011-03-01

    Dynamic clamp is a powerful method that allows the introduction of artificial electrical components into target cells to simulate ionic conductances and synaptic inputs. This method is based on a fast cycle of measuring the membrane potential of a cell, calculating the current of a desired simulated component using an appropriate model and injecting this current into the cell. Here we present a dynamic clamp protocol using free, fully integrated, open-source software (StdpC, for spike timing-dependent plasticity clamp). Use of this protocol does not require specialist hardware, costly commercial software, experience in real-time operating systems or a strong programming background. The software enables the configuration and operation of a wide range of complex and fully automated dynamic clamp experiments through an intuitive and powerful interface with a minimal initial lead time of a few hours. After initial configuration, experimental results can be generated within minutes of establishing cell recording.

  15. Molecular Mechanisms of DNA Polymerase Clamp Loaders

    NASA Astrophysics Data System (ADS)

    Kelch, Brian; Makino, Debora; Simonetta, Kyle; O'Donnell, Mike; Kuriyan, John

    Clamp loaders are ATP-driven multiprotein machines that couple ATP hydrolysis to the opening and closing of a circular protein ring around DNA. This ring-shaped clamp slides along DNA, and interacts with numerous proteins involved in DNA replication, DNA repair and cell cycle control. Recently determined structures of clamp loader complexes from prokaryotic and eukaryotic DNA polymerases have revealed exciting new details of how these complex AAA+ machines perform this essential clamp loading function. This review serves as background to John Kuriyan's lecture at the 2010 Erice School, and is not meant as a comprehensive review of the contributions of the many scientists who have advanced this field. These lecture notes are derived from recent reviews and research papers from our groups.

  16. Clamp force and alignment checking device

    DOEpatents

    Spicer, John Patrick; Cai, Wayne W.; Chakraborty, Debejyo; Mink, Keith

    2017-04-11

    A check fixture measures a total clamp force applied by a welder device. The welder device includes a welding horn having a plurality of weld pads and welding anvil having a plurality of weld pads. The check fixture includes a base member operatively supporting a plurality of force sensors. The base member and the force sensors are received between the weld pads of the welding horn and the anvil pads of the welding anvil. Each force sensor is configured to measure an individual clamp force applied thereto by corresponding weld and anvil pads when the base member is received between the welding horn and the welding anvil and the welder device is in the clamped position. The individual clamp forces are used to determine whether the weld and/or anvil pads are worn or misaligned.

  17. Gas Hydrate Research Coring and Downhole Logging Operational Protocol

    NASA Astrophysics Data System (ADS)

    Collett, T. S.; Riedel, M.; Malone, M.

    2006-12-01

    Recent gas hydrate deep coring and downhole logging projects, including ODP Leg 204, IODP Expedition 311, and the India NGHP-01 effort have contributed greatly to our understanding of the geologic controls on the occurrence of gas hydrate. These projects have also built on the relatively sparse history of gas hydrate drilling experience to collectively develop a unique operational protocol to examine and sample gas hydrate in nature. The ideal gas hydrate research drill site in recent history, consists of at least three drill holes, with the first hole dedicated to LWD/MWD downhole logging in order to identify intervals to be pressurized cored and to collect critical petrophysical data. The second hole is usually dedicated for continuous coring operations. The third hole is used for special downhole tool measurements such as pressure coring and wire line logging. There is a strong scientific need to obtain LWD/MWD data prior to coring. The coring operations are complemented by frequent deployment of the PCS/HYACINTH pressure core systems. It is essential to know what the gas hydrate concentrations and vertical distribution are before deploying the available pressure core systems in order to choose the optimum depths for pressure coring operations. The coring operations are also complemented by frequent sampling for interstitial water, headspace gas, and microbiological analyses. Although those samples will be taken at relatively regular depths, the sampling frequency can be adjusted if gas hydrate concentrations and distribution can be forward predicted through the analysis of the LWD/MWD pre-core logging surveys. After completing the LWD/MWD logging program, usually as a dedicated drilling leg, field efforts will switch to conventional and pressure-controlled coring operations at each of the sites drilled during the LWD/MWD campaign. The standard continuous core hole will usually include APC coring to an expected refusal depth of ~100 mbsf; each hole is usually

  18. Improved Algorithm for Automated Glucose Clamps.

    PubMed

    Kuhlenkötter, Mareike; Heise, Tim; Benesch, Carsten

    2017-02-01

    In glucose clamp experiments, blood glucose concentrations (BGs) are kept as close as possible to a predefined target level using variable glucose infusion rates (GIRs). In automated clamps, GIRs are calculated by algorithms implemented in the device (e.g., the Biostator). Low BG- and GIR-variability is needed for high clamp quality. We therefore tried to reduce oscillations in both BG and GIR with an improved algorithm implemented in ClampArt, a modern clamp device. The Biostator algorithm was first improved by numerical simulations of glucose clamps (in silico). With the results of the simulations, we started in vitro experiments using the ClampArt device and a container with water and glucose as "test subject." After a small pilot in vivo study, a larger clinical study was performed to compare the original with the optimized algorithm. With the improved algorithm, in silico, in vitro, and in vivo experiments showed reduced oscillations in both BG and GIR. In the clinical study, the coefficient of variation (CV) of BG values was lowered from 6.0% (4.6%-7.8%) [median (interquartile range)] to 4.2% (3.6%-5.0%), P < 0.0001 and the CV of GIR from 60.7% (49.6%-82.0%) to 43.5% (32.8%-57.2%), P < 0.0001. Other clamp quality parameters did not change substantially, median deviation from target slightly increased from 0.6% (0.2%-1.0%) to 1.1% (0.7%-1.5%), P = 0.0005, whereas utility did not change [97.0% (93.4%-100.0%) vs. 97.0% (94.0%-98.8%), P = 0.57]. With the improved algorithm, all experiments confirmed a reduction in BG- and GIR-oscillations without a major impact on other glucose clamp parameters. The optimized algorithm has been implemented in ClampArt for all future glucose clamp studies.

  19. Curtiss XSO3C-1 Seagull

    NASA Technical Reports Server (NTRS)

    1940-01-01

    Curtiss XSO3C-1 Seagull: Although drag reduction was very important to radial engined aircraft, it was no less important to aircraft such as this inline Ranger powered Curtiss XSO3C-1 Seagull. Here the Seagull is shown in the 30 x 60 Full Scale Tunnel in October of 1940. The XSO3C-1 was also undergoing study to improve engine cooling. Published in Aircraft; FST; Curtiss XSO3C-1 Seagull; Full Scale Tunnel; Nicklas

  20. Structural analysis of a eukaryotic sliding DNA clamp-clamp loadercomplex.

    SciTech Connect

    Bowman, Gregory D.; O'Donnell, Mike; Kuriyan, John

    2006-06-17

    Sliding clamps are ring-shaped proteins that encircle DNA and confer high processivity on DNA polymerases. Here we report the crystal structure of the five-protein clamp loader complex (replication factor-C, RFC) of the yeast Saccharomyces cerevisiae, bound to the sliding clamp (proliferating cell nuclear antigen, PCNA). Tight interfacial coordination of the ATP analogue ATP-?-S by RFC results in a spiral arrangement of the ATPase domains of the clamp loader above the PCNA ring. Placement of a model for primed DNA within the central hole of PCNA reveals a striking correspondence between the RFC spiral and the grooves of the DNA double helix. This model, in which the clamp loader complex locks onto primed DNA in a screw-cap-like arrangement, provides a simple explanation for the process by which the engagement of primer-template junctions by the RFC:PCNA complex results in ATP hydrolysis and release of the sliding clamp on DNA.

  1. Diverless pipeline repair clamp: Phase 1

    SciTech Connect

    Miller, J.E.; Knott, B. )

    1991-12-01

    Offshore oil and gas developments are underway for water depths beyond which divers can function. The economic lifelines of these projects are the pipelines which will transport the products to shore. In preparation for the day when one of these pipelines will require repair because of a leak, the Pipeline Research Committee of the American Gas Association is funding research directed at developing diverless pipeline repair capabilities. Several types of damage are possible, ranging from latent weld defects on one end of the spectrum to damage resulting in parting of the pipe at the other end. This study is specifically directed toward laying the groundwork for development of a diverless pipeline repair clamp for use in repair of leaks resulting from minor pipe defects. The incentive for a clamp type repair is costs. When compared to replacing a section of pipe, either by welding or by mechanical means, the clamp type repair requires much less disturbance of the pipe, less time, fewer operations and less equipment. This report summarizes (1) capabilities of remotely operated vehicles (ROV's) and associated systems, (2) highlights areas for further research and development, (3) describes the required capabilities of the diverless repairclamp, (4) investigates some alternatives to the diverless clamp, (5) overviews the state of the art in leak repair clamps, and (6) critiques several possible generic clamp concepts.

  2. Sound absorption by clamped poroelastic plates.

    PubMed

    Aygun, H; Attenborough, K

    2008-09-01

    Measurements and predictions have been made of the absorption coefficient and the surface acoustic impedance of poroelastic plates clamped in a large impedance tube and separated from the rigid termination by an air gap. The measured and predicted absorption coefficient and surface impedance spectra exhibit low frequency peaks. The peak frequencies observed in the absorption coefficient are close to those predicted and measured in the deflection spectra of the clamped poroelastic plates. The influences of the rigidity of the clamping conditions and the width of the air gap have been investigated. Both influences are found to be important. Increasing the rigidity of clamping reduces the low frequency absorption peaks compared with those measured for simply supported plates or plates in an intermediate clamping condition. Results for a closed cell foam plate and for two open cell foam plates made from recycled materials are presented. For identical clamping conditions and width of air gap, the results for the different materials differ as a consequence mainly of their different elasticity, thickness, and cell structure.

  3. 18 CFR 3c.2 - Nonpublic information.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Nonpublic information. 3c.2 Section 3c.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES STANDARDS OF CONDUCT § 3c.2 Nonpublic information. (a) Section 1264(d) (42...

  4. 18 CFR 3c.2 - Nonpublic information.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Nonpublic information. 3c.2 Section 3c.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES STANDARDS OF CONDUCT § 3c.2 Nonpublic information. (a) Section 1264(d) (42...

  5. 18 CFR 3c.2 - Nonpublic information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Nonpublic information. 3c.2 Section 3c.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES STANDARDS OF CONDUCT § 3c.2 Nonpublic information. (a) Section 1264(d) (42...

  6. 18 CFR 3c.2 - Nonpublic information.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Nonpublic information. 3c.2 Section 3c.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES STANDARDS OF CONDUCT § 3c.2 Nonpublic information. (a) Section 1264(d) (42...

  7. 18 CFR 3c.2 - Nonpublic information.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Nonpublic information. 3c.2 Section 3c.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES STANDARDS OF CONDUCT § 3c.2 Nonpublic information. (a) Section 1264(d) (42...

  8. Program for the improvement of downhole drilling motors

    SciTech Connect

    Finger, J.T.

    1983-11-01

    This report describes the work done under contract to Sandia National Labs and to the Department of Energy for improvement of downhole drilling motors. The focus of this program was the development of a better bearing-and-seal assembly that could be used in different kinds of drilling motors in a geothermal environment. Major tasks were: (1) design and construction of seal testing devices, (2) screening and evaluation of candidate seals in a simulated bearing/seal package, (3) tests of the most promising candidates in a full-scale bearing/seal package, and (4) analysis of failed seals after testing. The key results from this program were: (1) identification of seal/shaft/lubricant systems that performed well at high pressure and temperature, (2) identification of other seal designs that should be avoided for similar applications, and (3) evaluation of the test machines' design.

  9. Element for use in an inductive coupler for downhole components

    DOEpatents

    Hall, David R [Provo, UT; Fox, Joe [Spanish Fork, UT

    2009-03-31

    An element for use in an inductive coupler for downhole components comprises an annular housing having a generally circular recess. The element further comprises a plurality of generally linear, magnetically conductive segments. Each segment includes a bottom portion, an inner wall portion, and an outer wall portion. The portions together define a generally linear trough from a first end to a second end of each segment. The segments are arranged adjacent to each other within the housing recess to form a generally circular trough. The ends of at least half of the segments are shaped such that the first end of one of the segments is complementary in form to the second end of an adjacent segment. In one embodiment, all of the ends are angled. Preferably, the first ends are angled with the same angle and the second ends are angled with the complementary angle.

  10. 275 C Downhole Switched-Mode Power Supply

    SciTech Connect

    Chris Hutchens; Vijay Madhuravasal

    2008-08-31

    A vee-square (V2) control based controller IC is developed for a switch mode power supply capable of operating at extreme temperature/harsh environment conditions. A buck type regulator with silicon carbide power junction field effect transistors (JFET) as power devices is used to analyze the performance of controller. Special emphases are made on the analog sub-blocks--voltage reference, operational transconductance amplifier and comparator as individual building blocks. Transformer coupled gate drives and high temperature operable magnetic cores and capacitors are identified and tested for use in the design. Conventional ceramic chip packaging of ICs combined with lead carrier type mounting of passive filter components is introduced for hybrid packaging of the complete product. The developed SMPS is anticipated to support the operation of down-hole microcontrollers and other electronics devices that require low/medium power filtered dc inputs over an operating temperature of 275 C.

  11. Comparative evaluation of surface and downhole steam-generation techniques

    NASA Astrophysics Data System (ADS)

    Hart, C.

    The application of heat to reservoirs containing high API gravity oils can substantially improve recovery. Although steam injection is currently the principal thermal recovery method, heat transmission losses associated with delivery of the steam from the surface generators to the oil bearing formation has limited conventional steam injection to shallow reservoirs. The objective of the Department of Energy's Project DEEP STEAM is to develop the technology required to economically produce heavy oil from deep reservoirs. The tasks included in this effort are the development and evaluation of thermally efficient delivery systems and downhole steam generation systems. The technical and economic performance of conventional surface steam drives, which are strongly influenced by heat losses are compared. The selection of a preferred technology based upon either total efficiency or cost is found to be strongly influenced by reservoir depth, steam mass flow rate, and sandface steam quality.

  12. Development of seals for a geothermal downhole intensifier. Progress report

    SciTech Connect

    Captain, K.M.; Harvey, A.C.; Caskey, B.C.

    1985-08-01

    A system using high-velocity fluid jets in conjunction with a rotary diamond bit is currently considered as the best candidate for reducing the cost of drilling geothermal wells. Technical, safety and cost considerations indicate that the required jet supply pressure can best be established by a downhole pressure intensifier. Key intensifier components are the check valve and plunger seals, which must prevent leakage of the high-pressure, high-temperature abrasive fluid (drilling mud). To achieve the required performance, novel ceramic seals are currently being developed. The check valve seal includes a tapered polymeric plug and ceramic stop acting against a ceramic seat. The ceramic plunger seal is a variant of the ''stepped-joint'' piston ring and is designed to minimize contact pressure and abrasive wear. Initial testing of these seals in the laboratory shows encouraging results; design refinement and further testing is in progress. 2 refs., 6 figs., 3 tabs.

  13. Passive Downhole Pressure Sensor Based on Surface Acoustic Wave Technology.

    PubMed

    Quintero, Sully M M; Figueiredo, Sávio W O; Takahashi, Victor L; Llerena, Roberth A W; Braga, Arthur M B

    2017-07-15

    A passive surface acoustic wave (SAW) pressure sensor was developed for real-time pressure monitoring in downhole application. The passive pressure sensor consists of a SAW resonator, which is attached to a circular metal diaphragm used as a pressure transducer. While the membrane deflects as a function of pressure applied, the frequency response changes due to the variation of the SAW propagation parameters. The sensitivity and linearity of the SAW pressure sensor were measured to be 8.3 kHz/bar and 0.999, respectively. The experimental results were validated with a hybrid analytical-numerical analysis. The good results combined with the robust design and packaging for harsh environment demonstrated it to be a promising sensor for industrial applications.

  14. The how and why of downhole safety valves

    SciTech Connect

    Bleakley, W.B.

    1986-01-01

    Downhole safety valves are designed to prevent the uncontrolled production of oil or gas from a well, in the event of damage to the Christmas tree or flow lines, or failure of surface control equipment. The first downhole safety valves were fairly simple devices invented primarily to protect caisson-type completions offshore from blowing out as a result of a collision on the surface. Caisson completions were vulnerable to damage because the wellhead was protected only by some pilings-frequently wood-driven into the ocean floow in shallow waters. The wells were drilled from submersible barges, usually, in near shore or inland waters. There was justified concern collisions could occur, with workboats or sports-fishing boats, to the extent that well control would be lost. Another concern was severe weather which could damage caisson-type completions-and platforms-to allow uncontrolled flow from wells. One of the manufacturers registered the name Storm Choke for its product, a name that has almost become generic, although still under legal protection. Early models of subsurface safety valves worked on the velocity principle. If flow through the tubing exceeded a fixed maximum, the valve would close. At that time, the maximum was established at something higher than the well's allowable producing rate. Since allowables are no longer effective, the maximum is fixed by the well's characteristics relative to reservoir damage, sand production, or water coning. The reasons subsurface safety valves are used remain the same, but today's designs are high-tech, many can be controlled from the surface, testing is fairly simple, and platform wells can be shut in individually or all at one time.

  15. DOWNHOLE POWER GENERATION AND WIRELESS COMMUNICATIONS FOR INTELLIGENT COMPLETIONS APPLICATIONS

    SciTech Connect

    Paul Tubel

    2003-10-14

    The fourth quarter of the project was dedicated to the manufacturing of the mechanical system for wireless communications and the power generation module and inspection pre assembly of the mechanical components. Another emphasis for the quarter was the development of filter control and signal detection software. The tasks accomplished during this report period were: (1) Dimensional issues were resolved and revised drawings for manufacturing of the wireless communications gauge and power generator were completed and sent to a machine shop for manufacturing. (2) Finalized the requirements and fittings and connections for testing the tool in the Halliburton flow loop. (3) The new acoustic generator was manufactured successfully and it was delivered during this quarter. The assembly will be outsourced for plastic coating in preparation for hostile environment use. (4) The acoustic two-way communications development continued to progress. The real time firmware for the surface system was developed and the processor was able to detect and process the data frame transmitted from downhole. The analog section of the tool was also developed and it is being tested for filtering capabilities and signal detection and amplification. (5) The new transformer to drive the acoustic generator assembly was manufactured and was successfully tested. Spring mandrel design showed increased acoustic output on the pipe and was implemented. (6) PCBA board carrier with board set was tested for function and fit and is 100% complete. (7) Filter control software is complete and software to allow modification of communication parameters dynamically is 50% complete. (8) All mechanical parts to assemble the wireless gauge and power generator have been received and verified to be within specification. (9) Acoustic generator has been assembled in the tool mandrel and tested successfully. (10) The circuit required to harvest the power generated downhole has been designed and the power generator

  16. Lithostratigraphy from downhole logs in Hole AND-1B, Antarctica

    USGS Publications Warehouse

    Williams, Trevor; Morin, Roger H.; Jarrard, Richard D.; Jackolski, Chris L.; Henrys, Stuart A.; Niessen, Frank; Magens, Diana; Kuhn, Gerhard; Monien, Donata; Powell, Ross D.

    2012-01-01

    The ANDRILL (Antarctic Drilling Project) McMurdo Ice Shelf (MIS) project drilled 1285 m of sediment in Hole AND–1B, representing the past 12 m.y. of glacial history. Downhole geophysical logs were acquired to a depth of 1018 mbsf (meters below seafloor), and are complementary to data acquired from the core. The natural gamma radiation (NGR) and magnetic susceptibility logs are particularly useful for understanding lithological and paleoenvironmental change at ANDRILL McMurdo Ice Shelf Hole AND–1B. NGR logs cover the entire interval from the seafloor to 1018 mbsf, and magnetic susceptibility and other logs covered the open hole intervals between 692 and 1018 and 237–342 mbsf. In the upper part of AND–1B, clear alternations between low and high NGR values distinguish between diatomite (lacking minerals containing naturally radioactive K, U, and Th) and diamictite (containing K-bearing clays, K-feldspar, mica, and heavy minerals). In the lower open hole logged section, NGR and magnetic susceptibility can also distinguish claystones (rich in K-bearing clay minerals, relatively low in magnetite) and diamictites (relatively high in magnetite). Sandstones can be distinguished by their high resistivity values in AND–1B. On the basis of these three downhole logs, diamictite, claystones, and sandstones can be predicted correctly for 74% of the 692–1018 mbsf interval. The logs were then used to predict facies for the 6% of this interval that was unrecovered by coring. Given the understanding of the physical property characteristics of different facies, it is also possible to identify subtle changes in lithology from the physical properties and help refine parts of the lithostratigraphy, for example, the varying terrigenous content of diatomites and the transitions from subice diamictite to open-water diatomite.

  17. Method and apparatus for transmitting and receiving data to and from a downhole tool

    DOEpatents

    Hall, David R.; Fox, Joe

    2007-03-13

    A transmission line network system for transmitting and/or receiving data from a downhole tool. The invention is achieved by providing one or more transceiving elements, preferably rings, at either end of a downhole tool. A conduit containing a coaxial cable capable of communicating an electrical signal is attached to the transceiving element and extends through a central bore of the downhole tool and through the central bore of any tool intermediate the first transceiving element and a second transceiving element. Upon receiving an electrical signal from the cable, the second transceiving element may convert such signal to a magnetic field. The magnetic field may be detected by a third transceiving element in close proximity to the second transceiving element. In this manner, many different tools may be included in a downhole transmission network without requiring substantial modification, if any, of any particular tool.

  18. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Cable clamps and grips. 18.40 Section 18.40... Requirements § 18.40 Cable clamps and grips. Insulated clamps shall be provided for all portable (trailing) cables to prevent strain on the cable terminals of a machine. Also insulated clamps shall be provided to...

  19. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Cable clamps and grips. 18.40 Section 18.40... Requirements § 18.40 Cable clamps and grips. Insulated clamps shall be provided for all portable (trailing) cables to prevent strain on the cable terminals of a machine. Also insulated clamps shall be provided to...

  20. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Cable clamps and grips. 18.40 Section 18.40... Requirements § 18.40 Cable clamps and grips. Insulated clamps shall be provided for all portable (trailing) cables to prevent strain on the cable terminals of a machine. Also insulated clamps shall be provided to...

  1. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures....

  2. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures....

  3. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures....

  4. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures....

  5. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures....

  6. Piezoresistive cantilever force-clamp system

    SciTech Connect

    Park, Sung-Jin; Petzold, Bryan C.; Pruitt, Beth L.; Goodman, Miriam B.

    2011-04-15

    We present a microelectromechanical device-based tool, namely, a force-clamp system that sets or ''clamps'' the scaled force and can apply designed loading profiles (e.g., constant, sinusoidal) of a desired magnitude. The system implements a piezoresistive cantilever as a force sensor and the built-in capacitive sensor of a piezoelectric actuator as a displacement sensor, such that sample indentation depth can be directly calculated from the force and displacement signals. A programmable real-time controller operating at 100 kHz feedback calculates the driving voltage of the actuator. The system has two distinct modes: a force-clamp mode that controls the force applied to a sample and a displacement-clamp mode that controls the moving distance of the actuator. We demonstrate that the system has a large dynamic range (sub-nN up to tens of {mu}N force and nm up to tens of {mu}m displacement) in both air and water, and excellent dynamic response (fast response time, <2 ms and large bandwidth, 1 Hz up to 1 kHz). In addition, the system has been specifically designed to be integrated with other instruments such as a microscope with patch-clamp electronics. We demonstrate the capabilities of the system by using it to calibrate the stiffness and sensitivity of an electrostatic actuator and to measure the mechanics of a living, freely moving Caenorhabditis elegans nematode.

  7. An Ultrasonic Clamp for Bloodless Partial Nephrectomy

    NASA Astrophysics Data System (ADS)

    Lafon, Cyril; Bouchoux, Guillaume; Murat, François Joseph; Birer, Alain; Theillère, Yves; Chapelon, Jean Yves; Cathignol, Dominique

    2007-05-01

    Maximum conservation of the kidney is preferable through partial nephrectomy for patients at risk of disease recurrence of renal cancers. Haemostatic tools are needed in order to achieve bloodless surgery and reduce post surgery morbidity. Two piezo-ceramic transducers operating at a frequency of 4 MHz were mounted on each arm of a clamp. When used for coagulation purposes, two transducers situated on opposite arms of the clamp were driven simultaneously. Heat delivery was optimized as each transducers mirrored back to targeted tissues the wave generated by the opposite transducer. Real-time treatment monitoring with an echo-based technique was also envisaged with this clamp. Therapy was periodically interrupted so one transducer could generate a pulse. The echo returning from the opposite transducer was treated. Coagulation necroses were obtained in vitro on substantial thicknesses (23-38mm) of pig liver over exposure durations ranging from 30s to 130s, and with acoustic intensities of less than 15W/cm2 per transducer. Both kidneys of two pigs were treated in vivo with the clamp (14.5W/cm2 for 90s), and the partial nephrectomies performed proved to be bloodless. In vitro and in vivo, wide transfixing lesions corresponded to an echo energy decrease superior to -10dB and parabolic form of the time of flight versus treatment time. In conclusion, this ultrasound clamp has proven to be an excellent mean for achieving monitored haemostasis in kidney.

  8. Report covering examination of parts from downhole steam generators. [Combustor head and sleeve parts

    SciTech Connect

    Pettit, F. S.; Meier, G. H.

    1983-08-01

    Combustor head and sleeve parts were examined by using optical and scanning electron metallography after use in oxygen/diesel and air/diesel downhole steam generators. The degradation of the different alloy components is described in terms of reactions with oxygen, sulfur and carbon in the presence of cyclic stresses, all generated by the combustion process. Recommendations are presented for component materials (alloys and coatings) to extend component lives in the downhole steam generators. 9 references, 22 figures, 3 tables.

  9. Apparatus for downhole drilling communications and method for making and using the same

    DOEpatents

    Normann, R.A.; Lockwood, G.J.; Gonzales, M.

    1998-03-03

    An apparatus for downhole drilling communications is presented. The apparatus includes a spool and end pieces for maintaining the spool at the bottom of a drill string near a drill bit during drilling operations. The apparatus provides a cable for communicating signals between a downhole electronics package and a surface receiver in order to perform measurements while drilling. A method of forming the apparatus is also set forth wherein the apparatus is formed about a central spindle and lathe. 6 figs.

  10. Apparatus for downhole drilling communications and method for making and using the same

    DOEpatents

    Normann, Randy A.; Lockwood, Grant J.; Gonzales, Meliton

    1998-01-01

    An apparatus for downhole drilling communications is presented. The apparatus includes a spool and end pieces for maintaining the spool at the bottom of a drill string near a drill bit during drilling operations. The apparatus provides a cable for communicating signals between a downhole electronics package and a surface receiver in order to perform measurements while drilling. A method of forming the apparatus is also set forth wherein the apparatus is formed about a central spindle and lathe.

  11. Compact, Stiff, Remotely-Actuable Quick-Release Clamp

    NASA Technical Reports Server (NTRS)

    Tsai, Ted W. (Inventor)

    2000-01-01

    The present invention provides a clamp that is compact and lightweight, yet provides high holding strength and stiffness or rigidity. The clamp uses a unique double slant interface design which provides mechanical advantages to resist forces applied to the clamp member as the load increases. The clamp allows for rapid and remote-activated release of the clamp jaws by applying only a small operating force to an over-center lock/release mechanism, such as by pulling a manual tether.

  12. History of electrophysiology and the patch clamp.

    PubMed

    Verkhratsky, Alexei; Parpura, Vladimir

    2014-01-01

    We provide a historic outlook on the development of the concept of bioelectricity, with emphasis on the neuromuscular junction as a model that revolutionized our thinking of the nerve, nervous, and muscle tissue excitability. We abridge some crucial experiments in defining the electrical excitability of biological cells. We also provide an insight into developments of tools and methods, which gradually yielded a contemporary "palette" of electrophysiology approaches, including the patch clamp. Pioneering steps in this journey, ranging from Galvani's experiments using the Leyden jar to those of Neher and Sakmann using a gigaseal patch-clamp approach, are pictorially illustrated. This chapter is meant to be a perspective to the following sections in this volume dedicated to patch-clamp methods and protocols.

  13. The pathophysiology of aortic cross-clamping.

    PubMed

    Zammert, Martin; Gelman, Simon

    2016-09-01

    During open aortic surgery, interrupting the blood flow through the aorta by applying a cross-clamp is often a key step to allow for surgical repair. As a consequence, ischemia is induced in parts of the body distal to the clamp site. This significant alteration in the blood flow is almost always associated with hemodynamic changes. Upon release of the cross-clamp, the blood flow is restored, triggering an ischemia-reperfusion response, leading to many pathophysiological processes such as inflammation, humoral changes, and metabolite circulation that could lead to injury in many organ systems and may significantly influence the postoperative outcome. It is therefore important to understand these processes and how they can be treated in order to allow for safe surgical aortic repairs while ensuring the best possible outcomes.

  14. Perspectives on implementing delayed cord clamping.

    PubMed

    Leslie, Mayri Sagady

    2015-01-01

    Expanding evidence supports delayed cord clamping (DCC) for both term and preterm infants. This article explores issues that may be keeping early cord clamping (ECC) in place as usual practice. Professional organizations almost universally recommend DCC for preterm infants, but some reserve recommending it for term infants only in resource-poor settings. Concerns about polycythemia and jaundice persist in the literature, while years of published randomized controlled trials do not support the assumptions behind the concerns. New data suggest that DCC may improve resuscitative efforts in compromised infants. Multiple perspectives are offered for consideration when thinking about incorporating DCC into practice. © 2015 AWHONN.

  15. Surface-Source Downhole Seismic Analysis in R

    USGS Publications Warehouse

    Thompson, Eric M.

    2007-01-01

    This report discusses a method for interpreting a layered slowness or velocity model from surface-source downhole seismic data originally presented by Boore (2003). I have implemented this method in the statistical computing language R (R Development Core Team, 2007), so that it is freely and easily available to researchers and practitioners that may find it useful. I originally applied an early version of these routines to seismic cone penetration test data (SCPT) to analyze the horizontal variability of shear-wave velocity within the sediments in the San Francisco Bay area (Thompson et al., 2006). A more recent version of these codes was used to analyze the influence of interface-selection and model assumptions on velocity/slowness estimates and the resulting differences in site amplification (Boore and Thompson, 2007). The R environment has many benefits for scientific and statistical computation; I have chosen R to disseminate these routines because it is versatile enough to program specialized routines, is highly interactive which aids in the analysis of data, and is freely and conveniently available to install on a wide variety of computer platforms. These scripts are useful for the interpretation of layered velocity models from surface-source downhole seismic data such as deep boreholes and SCPT data. The inputs are the travel-time data and the offset of the source at the surface. The travel-time arrivals for the P- and S-waves must already be picked from the original data. An option in the inversion is to include estimates of the standard deviation of the travel-time picks for a weighted inversion of the velocity profile. The standard deviation of each travel-time pick is defined relative to the standard deviation of the best pick in a profile and is based on the accuracy with which the travel-time measurement could be determined from the seismogram. The analysis of the travel-time data consists of two parts: the identification of layer-interfaces, and the

  16. The high energy source 3C 273

    NASA Technical Reports Server (NTRS)

    Vonmontigny, Corinna

    1990-01-01

    The properties of 3C 273 are reviewed and an attempt is made to find an answer to the question why 3C 273 is the only extragalactic source so far, which was detected at energies greater than or equal to 50 MeV.

  17. Kinetic analysis of PCNA clamp binding and release in the clamp loading reaction catalyzed by Saccharomyces cerevisiae replication factor C

    PubMed Central

    Marzahn, Melissa R.; Hayner, Jaclyn N.; Meyer, Jennifer A.; Bloom, Linda B.

    2014-01-01

    DNA polymerases require a sliding clamp to achieve processive DNA synthesis. The toroidal clamps are loaded onto DNA by clamp loaders, members of the AAA+ family of ATPases. These enzymes utilize the energy of ATP binding and hydrolysis to perform a variety of cellular functions. In this study, a clamp loader-clamp binding assay was developed to measure the rates of ATP-dependent clamp binding and ATP-hydrolysis-dependent clamp release for the S. cerevisiae clamp loader (RFC) and clamp (PCNA). Pre-steady-state kinetics of PCNA binding showed that although ATP binding to RFC increases affinity for PCNA, ATP binding rates and ATP-dependent conformational changes in RFC are fast relative to PCNA binding rates. Interestingly, RFC binds PCNA faster than the Escherichia coli γ complex clamp loader binds the β-clamp. In the process of loading clamps on DNA, RFC maintains contact with PCNA while PCNA closes, as the observed rate of PCNA closing is faster than the rate of PCNA release, precluding the possibility of an open clamp dissociating from DNA. Rates of clamp closing and release are not dependent on the rate of the DNA binding step and are also slower than reported rates of ATP hydrolysis, showing that these rates reflect unique intramolecular reaction steps in the clamp loading pathway. PMID:25450506

  18. Kinetic analysis of PCNA clamp binding and release in the clamp loading reaction catalyzed by Saccharomyces cerevisiae replication factor C.

    PubMed

    Marzahn, Melissa R; Hayner, Jaclyn N; Meyer, Jennifer A; Bloom, Linda B

    2015-01-01

    DNA polymerases require a sliding clamp to achieve processive DNA synthesis. The toroidal clamps are loaded onto DNA by clamp loaders, members of the AAA+family of ATPases. These enzymes utilize the energy of ATP binding and hydrolysis to perform a variety of cellular functions. In this study, a clamp loader-clamp binding assay was developed to measure the rates of ATP-dependent clamp binding and ATP-hydrolysis-dependent clamp release for the Saccharomyces cerevisiae clamp loader (RFC) and clamp (PCNA). Pre-steady-state kinetics of PCNA binding showed that although ATP binding to RFC increases affinity for PCNA, ATP binding rates and ATP-dependent conformational changes in RFC are fast relative to PCNA binding rates. Interestingly, RFC binds PCNA faster than the Escherichia coli γ complex clamp loader binds the β-clamp. In the process of loading clamps on DNA, RFC maintains contact with PCNA while PCNA closes, as the observed rate of PCNA closing is faster than the rate of PCNA release, precluding the possibility of an open clamp dissociating from DNA. Rates of clamp closing and release are not dependent on the rate of the DNA binding step and are also slower than reported rates of ATP hydrolysis, showing that these rates reflect unique intramolecular reaction steps in the clamp loading pathway.

  19. Downhole temperature tool accurately measures well bore profile

    SciTech Connect

    Cloud, W.B. )

    1992-07-20

    This paper reports that an inexpensive temperature tool provides accurate temperatures measurements during drilling operations for better design of cement jobs, workovers, well stimulation, and well bore hydraulics. Valid temperature data during specific wellbore operations can improve initial job design, fluid testing, and slurry placement, ultimately enhancing well bore performance. This improvement applies to cement slurries, breaker activation for slurries, breaker activation for stimulation and profile control, and fluid rheological properties for all downhole operations. The temperature tool has been run standalone mounted inside drill pipe, on slick wire line and braided cable, and as a free-falltool. It has also been run piggyback on both directional surveys (slick line and free-fall) and standard logging runs. This temperature measuring system has been used extensively in field well bores to depths of 20,000 ft. The temperature tool is completely reusable in the field, ever similar to the standard directional survey tools used on may drilling rigs. The system includes a small, rugged, programmable temperature sensor, a standard body housing, various adapters for specific applications, and a personal computer (PC) interface.

  20. Downhole steam generator with improved preheating/cooling features

    DOEpatents

    Donaldson, A. Burl; Hoke, Donald E.; Mulac, Anthony J.

    1983-01-01

    An apparatus for downhole steam generation employing dual-stage preheaters for liquid fuel and for the water. A first heat exchange jacket for the fuel surrounds the fuel/oxidant mixing section of the combustor assembly downstream of the fuel nozzle and contacts the top of the combustor unit of the combustor assembly, thereby receiving heat directly from the combustion of the fuel/oxidant. A second stage heat exchange jacket surrounds an upper portion of the oxidant supply line adjacent the fuel nozzle receiving further heat from the compression heat which results from pressurization of the oxidant. The combustor unit includes an inner combustor sleeve whose inner wall defines the combustion zone. The inner combustor sleeve is surrounded by two concentric water channels, one defined by the space between the inner combustor sleeve and an intermediate sleeve, and the second defined by the space between the intermediate sleeve and an outer cylindrical housing. The channels are connected by an annular passage adjacent the top of the combustor assembly and the countercurrent nature of the water flow provides efficient cooling of the inner combustor sleeve. An annular water ejector with a plurality of nozzles is provided to direct water downwardly into the combustor unit at the boundary of the combustion zone and along the lower section of the intermediate sleeve.

  1. Drilling Optimization Utilizing Surface Instrumentaton for Downhole Event Recognition

    SciTech Connect

    John H. Cohen; Greg Deskins

    2006-02-01

    This DOE project was undertaken to develop and test an instrumented data-acquisition sub that is mounted in a drill string below the top drive and used to detect downhole events. Data recorded at the surface during drilling operations would then be processed and presented to the driller to discern undesirable drilling conditions and help optimize drilling rates and maximize the life of components in the BHA. This instrumented sub was originally conceived and developed solely as a single-point collection center for rig data that would be used in a number of Noble's products. The sub was designed to collect hook load, rotary torque, rotary speed, rotary position, drill pipe pressure, mud temperature, triaxial vibration, and triaxial magnetometer data. The original design and fabrication was by Sandia National Labs under Noble's direction, which was then tested with Sandia's diagnostics-while-drilling downhole package. After initial results were analyzed, the team surmised that important information describing performance and condition of the bottom-hole assembly (BHA) was embedded in the data recorded by the instrumented sub, and began investigating the potential of using surface measurements from the sub to highlight problems occurring downhole before they could be discerned by the driller. Later, a proposal was submitted to DOE for funding to more broadly investigate use of the system for detecting downhole problems while drilling. Soon after DOE awarded this contract, the Noble team responsible for the previous developments was disbanded and their work terminated (due to factors unrelated to the sub development). This change halted the complementary work that Noble had planned to conduct during the DOE project, and necessitated that all the development work be completed by the DOE project. More effort was expended on the project to develop a field-ready prototype than was originally foreseen. The sub's design had to be significantly modified during the project

  2. Evolution of the Snorre Field downhole completion systems

    SciTech Connect

    Gunnarsson, B.; Toennessen, S.H.; Stensland, J.F.; Haut, R.C.

    1994-12-31

    This paper discusses the development and evolution of cost-effective downhole completion systems for the Snorre Field Tension Leg Platform (TLP) and Subsea Production System (SPS). Included is a discussion of operational experiences that influenced the evolution. Also included in the paper are specific examples of how the completion times were reduced. The completion design for the subsea wells includes some new features compared to previous through flow line (TFL) completions. During the design process cost, safety and simplicity have been the driving forces for selecting equipment. Previous TFL completions have normally included a H-member, dual packers, sliding sleeves and nipples in each tail pipe. This design required plugs and standing valves to be an integral part of the completion string, requiring high reliability of the TFL retrievable components. The completion design used for the Snorre SPS wells uses a minimum amount of tubular components. The design does not require any TFL retrievable components to be installed during production or injection. This minimizes the number of flow restrictions and thereby reduces the tendency for scaling, erosion and corrosion on the TFL retrievable components. All tubing retrievable components, including the Y-block, are qualified and are considered standard today.

  3. Advances in downhole sampling of high temperature solutions

    SciTech Connect

    Bayhurst, G.K.; Janecky, D.R.

    1991-01-01

    A fluid sampler capable of sampling hot and/or deep wells has been developed at Los Alamos National Laboratory. In collaboration with Leutert Instruments, an off-the-shelf sampler design was modified to meet gas-tight and minimal chemical reactivity/contamination specifications for use in geothermal wells and deep ocean drillholes. This downhole sampler has been routinely used at temperatures up to 300{degrees}C and hole depths of greater than 5 km. We have tested this sampler in various continental wells, including Valles Caldera VC-2a and VC-2b, German KTB, Cajon Pass, and Yellowstone Y-10. Both the standard commercial and enhanced samplers have also been used to obtain samples from a range of depths in the Ocean Drilling Project's hole 504B and during recent mid-ocean ridge drilling efforts. The sampler has made it possible to collect samples at temperatures and conditions beyond the limits of other tools with the added advantage of chemical corrosion resistance.

  4. Inductive coupler for downhole components and method for making same

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Dahlgren, Scott; Briscoe, Michael A.; Sneddon, Cameron; Fox, Joe

    2006-05-09

    The present invention includes a method of making an inductive coupler for downhole components. The method includes providing an annular housing, preferably made of steel, the housing having a recess. A conductor, preferably an insulated wire, is also provided along with a plurality of generally U-shaped magnetically conducting, electrically insulating (MCEI) segments. Preferably, the MCEI segments comprise ferrite. An assembly is formed by placing the plurality of MCEI segments within the recess in the annular housing. The segments are aligned to form a generally circular trough. A first portion of the conductor is placed within the circular trough. This assembly is consolidated with a meltable polymer which fills spaces between the segments, annular housing and the first portion of the conductor. The invention also includes an inductive coupler including an annular housing having a recess defined by a bottom portion and two opposing side wall portions. At least one side wall portion includes a lip extending toward but not reaching the other side wall portion. A plurality of generally U-shaped MCEI segments, preferably comprised of ferrite, are disposed in the recess and aligned so as to form a circular trough. The coupler further includes a conductor disposed within the circular trough and a polymer filling spaces between the segments, the annular housing and the conductor.

  5. Patch-clamping Drosophila sensory neurons.

    PubMed

    Kucher, Volodymyr; Eaton, Benjamin A; Stockand, James D; Boiko, Nina

    2013-01-01

    Electrophysiological studies provide essential clues about the regulation and physiological function of ion channel proteins. Probing ion channel activity in vivo, though, often is challenging. This can limit the usefulness of such model organisms as Drosophila for electrophysiological studies. This is unfortunate because these genetically tractable organisms represent powerful research tools that facilitate elaboration of complex questions of physiology. Here, we describe a recently developed method for recording ion channel activity in Drosophila sensory neurons. This approach is based on patch-clamping primary neuron cultures from Drosophila embryos. Such cultures allow the study of ion channels in different genetic backgrounds. In addition to describing how to prepare a primary neuronal cell culture from Drosophila embryos, we discuss, as an example of utility, analysis of Na(+) currents in cultured class IV multidendritic (md) sensory neurons with the patch clamp technique. Excitability of md sensory neurons, manifested as action potential firing, is revealed with whole-cell current-clamping. Voltage-clamping class IV md neurons revealed the activity of the voltage-gated Na(+) channel, paralytic. Moreover, challenging class IV md neurons with acidic pH activates acid-sensing inward Na(+) currents. Genetic manipulation of Drosophila combined with this electrophysiological readout of activity identifies pickpocket1 (Ppk1), a member of the Deg/ENaC channel family, as responsible for conducting an acid-sensing Na(+) current in class IV md sensory neurons.

  6. Limit analysis of pipe clamps. Revision 1

    SciTech Connect

    Flanders, H.E. Jr.

    1990-12-31

    The Service Level D (faulted) load capacity of a conventional three-bolt pipe-clamp based upon the limit analysis method is presented. The load distribution, plastic hinge locations, and collapse load are developed for the lower bound limit load method. The results of the limit analysis are compared with the manufacturer`s rated loads. 3 refs.

  7. Patch-clamp amplifiers on a chip.

    PubMed

    Weerakoon, Pujitha; Culurciello, Eugenio; Yang, Youshan; Santos-Sacchi, Joseph; Kindlmann, Peter J; Sigworth, Fred J

    2010-10-15

    We present the first, fully integrated, two-channel implementation of a patch-clamp measurement system. With this "PatchChip" two simultaneous whole-cell recordings can be obtained with rms noise of 8pA in a 10kHz bandwidth. The capacitance and series-resistance of the electrode can be compensated up to 10pF and 100MΩ respectively under computer control. Recordings of hERG and Na(v) 1.7 currents demonstrate the system's capabilities, which are on par with large, commercial patch-clamp instrumentation. By reducing patch-clamp amplifiers to a millimeter size micro-chip, this work paves the way to the realization of massively parallel, high-throughput patch-clamp systems for drug screening and ion-channel research. The PatchChip is implemented in a 0.5μm silicon-on-sapphire process; its size is 3×3mm(2) and the power consumption is 5mW per channel with a 3.3V power supply.

  8. Π-Clamp-mediated cysteine conjugation.

    PubMed

    Zhang, Chi; Welborn, Matthew; Zhu, Tianyu; Yang, Nicole J; Santos, Michael S; Van Voorhis, Troy; Pentelute, Bradley L

    2016-02-01

    Site-selective functionalization of complex molecules is one of the most significant challenges in chemistry. Typically, protecting groups or catalysts must be used to enable the selective modification of one site among many that are similarly reactive, and general strategies that selectively tune the local chemical environment around a target site are rare. Here, we show a four-amino-acid sequence (Phe-Cys-Pro-Phe), which we call the 'π-clamp', that tunes the reactivity of its cysteine thiol for site-selective conjugation with perfluoroaromatic reagents. We use the π-clamp to selectively modify one cysteine site in proteins containing multiple endogenous cysteine residues. These examples include antibodies and cysteine-based enzymes that would be difficult to modify selectively using standard cysteine-based methods. Antibodies modified using the π-clamp retained binding affinity to their targets, enabling the synthesis of site-specific antibody-drug conjugates for selective killing of HER2-positive breast cancer cells. The π-clamp is an unexpected approach to mediate site-selective chemistry and provides new avenues to modify biomolecules for research and therapeutics.

  9. Patch-clamp amplifiers on a chip

    PubMed Central

    Weerakoon, Pujitha; Culurciello, Eugenio; Yang, Youshan; Santos-Sacchi, Joseph; Kindlmann, Peter J.; Sigworth, Fred J.

    2010-01-01

    We present the first, fully-integrated, two-channel implementation of a patch-clamp measurement system. With this “PatchChip” two simultaneous whole-cell recordings can be obtained with rms noise of 8 pA in a 10 kHz bandwidth. The capacitance and series-resistance of the electrode can be compensated up to 10 pF and 100 MΩ respectively under computer control. Recordings of hERG and Nav 1.7 currents demonstrate the system's capabilities, which are on par with large, commercial patch-clamp instrumentation. By reducing patch-clamp amplifiers to a millimeter size micro-chip, this work paves the way to the realization of massively-parallel, high-throughput patch-clamp systems for drug screening and ion-channel research. The PatchChip is implemented in a 0.5 μm silicon-on-sapphire process; its size is 3 × 3 mm2 and the power consumption is 5 mW per channel with a 3.3 V power supply. PMID:20637803

  10. Clamp and Gas Nozzle for TIG Welding

    NASA Technical Reports Server (NTRS)

    Gue, G. B.; Goller, H. L.

    1982-01-01

    Tool that combines clamp with gas nozzle is aid to tungsten/inert-gas (TIG) welding in hard-to-reach spots. Tool holds work to be welded while directing a stream of argon gas at weld joint, providing an oxygen-free environment for tungsten-arc welding.

  11. Flaring Quasar 3C454.3

    NASA Astrophysics Data System (ADS)

    Wehrle, Ann; Ogle, Patrick

    2005-06-01

    The quasar 3C454.3 is currently undergoing the largest optical flare in its recorded history: during the past three weeks it has exceeded even 3C273 in optical brightness. We propose to observe 3C454.3 with Spitzer IPAC, MIPS and IRS during each of their normally scheduled blocks in June, July and August 2005, and repeat observations daily. Supporting ground based data will be obtained from Palomar Mountain (approved observations on the 60" robotic telescope; A. Wehrle, PI), Colgate University, and other observatories of the international blazar monitoring teams. The Rossi X-ray Timing Explorer has already started observing as a Target of Opportunity.

  12. Dynamics and Stability of Pinned-Clamped and Clamped-Pinned Cylindrical Shells Conveying Fluid

    NASA Astrophysics Data System (ADS)

    Misra, A. K.; Wong, S. S. T.; Païdoussis, M. P.

    2001-11-01

    The paper examines the dynamics and stability of fluid-conveying cylindrical shells having pinned-clamped or clamped-pinned boundary conditions, where ``pinned'' is an abbreviation for ``simply supported''. Flügge's equations are used to describe the shell motion, while the fluid-dynamic perturbation pressure is obtained utilizing the linearized potential flow theory. The solution is obtained using two methods - the travelling wave method and the Fourier-transform approach. The results obtained by both methods suggest that the negative damping of the clamped-pinned systems and positive damping of the pinned-clamped systems, observed by previous investigators for any arbitrarily small flow velocity, are simply numerical artefacts; this is reinforced by energy considerations, in which the work done by the fluid on the shell is shown to be zero. Hence, it is concluded that both systems are conservative.

  13. COMPTEL observations of the Virgo blazars 3C 273 and 3C 279

    NASA Astrophysics Data System (ADS)

    Collmar, W.; Schönfelder, V.; Zhang, S.; Bloemen, H.; Hermsen, W.; McConnell, M.; Bennett, K.; Williams, O. R.

    2001-10-01

    We report the main MeV properties (detections, light curves, spectra) of the Virgo blazars 3C 273 and 3C 279 which were derived from a consistent analysis of all COMPTEL Virgo observations between 1991 and 1997. .

  14. Downhole geophysical observatories: best installation practices and a case history from Turkey

    NASA Astrophysics Data System (ADS)

    Prevedel, Bernhard; Bulut, Fatih; Bohnhoff, Marco; Raub, Christina; Kartal, Recai F.; Alver, Fatih; Malin, Peter E.

    2015-09-01

    Downhole sensors of different types and in various environments provide substantial benefit to signal quality. They also add the depth dimension to measurements performed at the Earths' surface. Sensor types that particularly benefit from downhole installation due to the absence of near-surface noise include piezometers, seismometers, strainmeters, thermometers, and tiltmeters. Likewise, geochemical and environmental measurements in a borehole help eliminate near-surface weathering and cultural effects. Installations from a few hundred meter deep to a few kilometer deep dramatically reduce surface noise levels—the latter noticeably also reduces the hypocentral distance for shallow microearthquakes. The laying out of a borehole network is always a compromise of local boundary conditions and the involved drilling costs. The installation depth and procedure for a long-term downhole observatory can range from time limited installations, with a retrieval option, to permanently cemented sensors. Permanently cemented sensors have proven to be long-term stable with non-deteriorating coupling and borehole integrity. However, each type needs to be carefully selected and planned according to the research aims. A convenient case study is provided by a new installation of downhole seismometers along the shoreline of the eastern Marmara Sea in Turkey. These stations are being integrated into the regional net for monitoring the North Anatolian Fault Zone. Here we discuss its design, installation, and first results. We conclude that, despite the logistical challenges and installation costs, the superior quality of downhole data puts this technique at the forefront of applied and fundamental research.

  15. Feasibility evaluation of downhole oil/water separator (DOWS) technology.

    SciTech Connect

    Veil, J. A.; Langhus, B. G.; Belieu, S.

    1999-01-31

    The largest volume waste stream associated with oil and gas production is produced water. A survey conducted by the American Petroleum Institute estimated that 20.9 billion barrels of produced water were disposed of in 1985 (Wakim 1987). Of this total, 91% was disposed of through disposal wells or was injected for enhanced oil recovery projects. Treatment and disposal of produced water represents a significant cost for operators. A relatively new technology, downhole oil/water separators (DOWS), has been developed to reduce the cost of handling produced water. DOWS separate oil and gas from produced water at the bottom of the well and reinject some of the produced water into another formation or another horizon within the same formation, while the oil and gas are pumped to the surface. Since much of the produced water is not pumped to the surface, treated, and pumped from the surface back into a deep formation, the cost of handling produced water is greatly reduced. When DOWS are used, additional oil may be recovered as well. In cases where surface processing or disposal capacity is a limiting factor for further production within a field, the use of DOWS to dispose of some of the produced water can allow additional production within that field. Simultaneous injection using DOWS minimizes the opportunity for contamination of underground sources of drinking water (USDWs) through leaks in tubing and casing during the injection process. This report uses the acronym 'DOWS' although the technology may also be referred to as DHOWS or as dual injection and lifting systems (DIALS). Simultaneous injection using DOWS has the potential to profoundly influence the domestic oil industry. The technology has been shown to work in limited oil field applications in the United States and Canada. Several technical papers describing DOWS have been presented at oil and gas industry conferences, but for the most part, the information on the DOWS technology has not been widely transferred

  16. Imaging hydraulic fractures by microseismic migration for downhole monitoring system

    NASA Astrophysics Data System (ADS)

    Lin, Ye; Zhang, Haijiang

    2016-12-01

    It has been a challenge to accurately characterize fracture zones created by hydraulic fracturing from microseismic event locations. This is because generally detected events are not complete due to the associated low signal to noise ratio and some fracturing stages may not produce microseismic events even if fractures are well developed. As a result, spatial distribution of microseismic events may not well represent fractured zones by hydraulic fracturing. Here, we propose a new way to characterize the fractured zones by reverse time migration (RTM) of microseismic waveforms from some events. This is based on the fact that fractures filled with proppants and other fluids can act as strong scatterers for seismic waves. Therefore, for multi-stage hydraulic fracturing, recorded waveforms from microseismic events induced in a more recent stage may be scattered by fractured zones from previous stages. Through RTM of microseismic waveforms in the current stage, we can determine fractured zones created in previous stages by imaging area of strong scattering. We test the feasibility of this method using synthetic models with different configurations of microseismic event locations and borehole sensor positions for a 2D downhole microseismic monitoring system. Synthetic tests show that with a few events fractured zones can be directly imaged and thus the stimulated reservoir volume (SRV) can be estimated. Compared to the conventional location-based SRV estimation method, the proposed new method does not depend on the completeness of detected events and only a limited number of detected and located events are necessary for characterizing fracture distribution. For simplicity, the 2D model is used for illustrating the concept of microseismic RTM for imaging the fracture zone but the method can be adapted to real cases in the future.

  17. Downhole fluid analysis and asphaltene science for petroleum reservoir evaluation.

    PubMed

    Mullins, Oliver C; Pomerantz, Andrew E; Zuo, Julian Y; Dong, Chengli

    2014-01-01

    Petroleum reservoirs are enshrouded in mysteries associated with all manner of geologic and fluid complexities that Mother Nature can inspire. Efficient exploitation of petroleum reservoirs mandates elucidation of these complexities; downhole fluid analysis (DFA) has proven to be indispensable for understanding both fluids and reservoir architecture. Crude oil consists of dissolved gases, liquids, and dissolved solids, known as the asphaltenes. These different fluid components exhibit fluid gradients vertically and laterally, which are best revealed by DFA, with its excellent precision and accuracy. Compositional gradient analysis falls within the purview of thermodynamics. Gas-liquid equilibria can be treated with a cubic equation of state (EoS), such as the Peng-Robinson EoS, a modified van der Waals EoS. In contrast, the first EoS for asphaltene gradients, the Flory-Huggins-Zuo (FHZ) EoS, was developed only recently. The resolution of the asphaltene molecular and nanocolloidal species in crude oil, which is codified in the Yen-Mullins model of asphaltenes, enabled the development of this EoS. The combination of DFA characterization of gradients of reservoir crude oil with the cubic EoS and FHZ EoS analyses brings into view wide-ranging reservoir concerns, such as reservoir connectivity, fault-block migration, heavy oil gradients, tar mat formation, huge disequilibrium fluid gradients, and even stochastic variations of reservoir fluids. New petroleum science and DFA technology are helping to offset the increasing costs and technical difficulties of exploiting ever-more-remote petroleum reservoirs.

  18. Mechanical properties of a lap joint under uniform clamping pressure

    NASA Technical Reports Server (NTRS)

    Diller, S. V.; Metherell, A. F.

    1969-01-01

    Equations were derived for the load deflection relations, the energy dissipation per cycle, and the instantaneous rate of dissipation for a lap joint idealized as two overlapping plates clamped together under a uniform clamping pressure.

  19. Clamp on ultrasonic instruments in subsea applications

    SciTech Connect

    Haugen, S.; Hodgson, S.; Upchurch, J.; McMahan, J.; Hazelrigg, K.; Mundorff, J.

    1995-12-01

    Monitoring of solids flow in pipelines has until recently required pipework intervention in order to insert probes and switches. Both sand particles and cleaning pigs are by nature destructive to these directly exposed detectors due to erosion and inertia. The instruments presented in this paper provide a superior alternative in ultrasonic clamp-on technology requiring only superficial pipework installation. Wells can now be operated efficiently in a way that minimizes the risk of erosion and collapse. Pigging operations can be monitored both by on-line pig detection and debris monitoring thereby allowing a safe and optimized survey to take place. The non-intrusive clamp-on concept raises standards in instrument reliability, durability and measurement performance.

  20. Towards a Dynamic Clamp for Neurochemical Modalities

    PubMed Central

    Rivera, Catalina Maria; Kwon, Hyuck-Jin; Hashmi, Ali; Yu, Gan; Zhao, Jiheng; Gao, Jianlong; Xu, Jie; Xue, Wei; Dimitrov, Alexander G.

    2015-01-01

    The classic dynamic clamp technique uses a real-time electrical interface between living cells and neural simulations in order to investigate hypotheses about neural function and structure. One of the acknowledged drawbacks of that technique is the limited control of the cells' chemical microenvironment. In this manuscript, we use a novel combination of nanosensor and microfluidic technology and microfluidic and neural simulations to add sensing and control of chemical concentrations to the dynamic clamp technique. Specifically, we use a microfluidic lab-on-a-chip to generate distinct chemical concentration gradients (ions or neuromodulators), to register the concentrations with embedded nanosensors and use the processed signals as an input to simulations of a neural cell. The ultimate goal of this project is to close the loop and provide sensor signals to the microfluidic lab-on-a-chip to mimic the interaction of the simulated cell with other cells in its chemical environment. PMID:25946635

  1. Mechanical and metallurgical properties of carotid artery clamps.

    PubMed

    Dujovny, M; Kossovsky, N; Kossowsky, R; Segal, R; Diaz, F G; Kaufman, H; Perlin, A; Cook, E E

    1985-11-01

    The mechanical and metallurgical properties of carotid artery clamps were evaluated. The pressure plate retreat propensity, metallurgical composition, surface morphology, magnetic properties, and corrosion resistance of the Crutchfield, Selverstone, Salibi, and Kindt clamps were tested. None of the clamps showed evidence of pressure plate retreat. The clamps differed significantly in their composition, surface cleanliness, magnetic properties, and corrosion resistance. The Crutchfield clamp was the only one manufactured from an ASTM-ANSI-approved implantable stainless steel (AISI 316) and the only clamp in which the surfaces were clean and free of debris. The Selverstone clamp was made principally from AISI 304 stainless steel, as was one Salibi clamp. The pressure plate on another Salibi clamp was made from a 1% chromium and 1% manganese steel. Machining and surface debris consisting principally of aluminum, silicon, and sulfur was abundant on the Selverstone and Salibi clamps. The Kindt clamp was manufactured from AISI 301 stainless steel with a silicate-aluminized outer coating. The Crutchfield and Selverstone clamps were essentially nonferromagnetic, whereas the Salibi and Kindt clamps were sensitive to magnetic flux. In the pitting potential corrosion test, the Crutchfield clamp demonstrated good corrosion resistance with a pitting potential of 310 mV and no surface corrosion or pitting by scanning electron microscopy examination. The Selverstone clamp had lower pitting potentials and showed various degrees of corrosion and surface pitting by scanning electron microscopy. The Salibi pressure plate had a very low pitting potential of -525 mV and showed severe corrosion. By metallurgical criteria, only the Crutchfield clamp is suitable for long term implantation.

  2. π-Clamp-mediated cysteine conjugation

    NASA Astrophysics Data System (ADS)

    Zhang, Chi; Welborn, Matthew; Zhu, Tianyu; Yang, Nicole J.; Santos, Michael S.; van Voorhis, Troy; Pentelute, Bradley L.

    2016-02-01

    Site-selective functionalization of complex molecules is one of the most significant challenges in chemistry. Typically, protecting groups or catalysts must be used to enable the selective modification of one site among many that are similarly reactive, and general strategies that selectively tune the local chemical environment around a target site are rare. Here, we show a four-amino-acid sequence (Phe-Cys-Pro-Phe), which we call the ‘π-clamp’, that tunes the reactivity of its cysteine thiol for site-selective conjugation with perfluoroaromatic reagents. We use the π-clamp to selectively modify one cysteine site in proteins containing multiple endogenous cysteine residues. These examples include antibodies and cysteine-based enzymes that would be difficult to modify selectively using standard cysteine-based methods. Antibodies modified using the π-clamp retained binding affinity to their targets, enabling the synthesis of site-specific antibody-drug conjugates for selective killing of HER2-positive breast cancer cells. The π-clamp is an unexpected approach to mediate site-selective chemistry and provides new avenues to modify biomolecules for research and therapeutics.

  3. Temperature-Controlled Clamping and Releasing Mechanism

    NASA Technical Reports Server (NTRS)

    Rosing, David; Ford, Virginia

    2005-01-01

    A report describes the development of a mechanism that automatically clamps upon warming and releases upon cooling between temperature limits of approx. =180 K and approx. =293 K. The mechanism satisfied a need specific to a program that involved repeated excursions of a spectrometer between a room-temperature atmospheric environment and a cryogenic vacuum testing environment. The mechanism was also to be utilized in the intended application of the spectrometer, in which the spectrometer would be clamped for protection during launch of a spacecraft and released in the cold of outer space to allow it to assume its nominal configuration for scientific observations. The mechanism is passive in the sense that its operation does not depend on a control system and does not require any power other than that incidental to heating and cooling. The clamping and releasing action is effected by bolt-preloaded stacks of shape-memory-alloy (SMA) cylinders. In designing this mechanism, as in designing other, similar SMA mechanisms, it was necessary to account for the complex interplay among thermal expansion, elastic and inelastic deformation under load, and SMA thermomechanical properties.

  4. Carbon nanotube-clamped metal atomic chain

    PubMed Central

    Tang, Dai-Ming; Yin, Li-Chang; Li, Feng; Liu, Chang; Yu, Wan-Jing; Hou, Peng-Xiang; Wu, Bo; Lee, Young-Hee; Ma, Xiu-Liang; Cheng, Hui-Ming

    2010-01-01

    Metal atomic chain (MAC) is an ultimate one-dimensional structure with unique physical properties, such as quantized conductance, colossal magnetic anisotropy, and quantized magnetoresistance. Therefore, MACs show great potential as possible components of nanoscale electronic and spintronic devices. However, MACs are usually suspended between two macroscale metallic electrodes; hence obvious technical barriers exist in the interconnection and integration of MACs. Here we report a carbon nanotube (CNT)-clamped MAC, where CNTs play the roles of both nanoconnector and electrodes. This nanostructure is prepared by in situ machining a metal-filled CNT, including peeling off carbon shells by spatially and elementally selective electron beam irradiation and further elongating the exposed metal nanorod. The microstructure and formation process of this CNT-clamped MAC are explored by both transmission electron microscopy observations and theoretical simulations. First-principles calculations indicate that strong covalent bonds are formed between the CNT and MAC. The electrical transport property of the CNT-clamped MAC was experimentally measured, and quantized conductance was observed. PMID:20427743

  5. π-Clamp Mediated Cysteine Conjugation

    PubMed Central

    Zhang, Chi; Welborn, Matthew; Zhu, Tianyu; Yang, Nicole J.; Santos, Michael S.; Van Voorhis, Troy; Pentelute, Bradley L.

    2016-01-01

    Site-selective functionalization of complex molecules is a grand challenge in chemistry. Protecting groups or catalysts must be used to selectively modify one site among many that are similarly reactive. General strategies are rare such the local chemical environment around the target site is tuned for selective transformation. Here we show a four amino acid sequence (Phe-Cys-Pro-Phe), which we call the “π-clamp”, tunes the reactivity of its cysteine thiol for the site-selective conjugation with perfluoroaromatic reagents. We used the π-clamp to selectively modify one cysteine site in proteins containing multiple endogenous cysteine residues (e.g. antibodies and cysteine-based enzymes), which was impossible with prior cysteine modification methods. The modified π-clamp antibodies retained binding affinity to their targets, enabling the synthesis of site-specific antibody-drug conjugates (ADCs) for selective killing of HER2-positive breast cancer cells. The π-clamp is an unexpected approach for site-selective chemistry and provides opportunities to modify biomolecules for research and therapeutics. PMID:26791894

  6. Design Enhancement and Performance Examination of External Rotor Switched Flux Permanent Magnet Machine for Downhole Application

    NASA Astrophysics Data System (ADS)

    Kumar, R.; Sulaiman, E.; Soomro, H. A.; Jusoh, L. I.; Bahrim, F. S.; Omar, M. F.

    2017-08-01

    The recent change in innovation and employments of high-temperature magnets, permanent magnet flux switching machine (PMFSM) has turned out to be one of the suitable contenders for seaward boring, however, less intended for downhole because of high atmospheric temperature. Subsequently, this extensive review manages the design enhancement and performance examination of external rotor PMFSM for the downhole application. Preparatory, the essential design parameters required for machine configuration are computed numerically. At that point, the design enhancement strategy is actualized through deterministic technique. At last, preliminary and refined execution of the machine is contrasted and as a consequence, the yield torque is raised from 16.39Nm to 33.57Nm while depreciating the cogging torque and PM weight up to 1.77Nm and 0.79kg, individually. In this manner, it is inferred that purposed enhanced design of 12slot-22pole with external rotor is convenient for the downhole application.

  7. An improved finite-difference calculation of downhole dynamometer cards for sucker-rod pumps

    SciTech Connect

    Everitt, T.A. )

    1992-02-01

    Sucker-rod pumping is the most widely used means of artificial lift. About 85% to 90% of all producing wells in the U.S. are rod-pumped. Thus, a reliable method of analyzing these pumping system is a necessity. For many years, the surface dynamometer has been used to analyze sucker-rod systems. Interpretation of actual pump conditions from surface dynamometer cards is often difficult, if not impossible. Results obtained from surface cards are strictly qualitative and are dependent on the analyzer's expertise. The ideal analysis procedure would be to measure the actual pump conditions with a downhole dynamometer. However, this situation is not economically feasible. Therefore, an accurate method of calculating downhole pump cards form measured surface cards is needed. This paper presents a method for calculating these downhole cards that uses a finite-difference representation of the wave equation. First, a brief description of previous calculation techniques is given.

  8. Operating manual for the R200 downhole recorder with Tandy 102 retriever

    USGS Publications Warehouse

    Johnson, Roy A.; Rorabaugh, James I.

    1988-01-01

    The R200 Downhole Recorder is a battery-powered device that, when placed in a well casing, monitors water levels for a period of up to 1 year. This instrument measures a 1- to 70-ft range of water levels. These water level data can be retrieved through use of a commercially available portable microcomputer. The R200 Downhole Recorder was developed at the U. S. Geological Survey 's Hydrologic Instrumentation Facility, Stennis Space Center, Mississippi. This operating manual describes the R200 Downhole Recorder, provides initial set-up instructions, and gives directions for on-site operation. Design specifications and routine maintenance steps are included. The R200 data-retriever program is a user-friendly, menu-driven program. The manual guides the user through the procedures required to perform specific operations. Numerous screens are reproduced in the text with a discussion of user input for desired responses. Help is provided for specific problems. (USGS)

  9. Operating manual for the R200 downhole recorder with husky hunter retriever

    USGS Publications Warehouse

    Johnson, Roy A.; Rorabaugh, James I.

    1988-01-01

    The R200 Downhole Recorder is a battery-powered device that, when placed in a well casing, monitors water levels for a period of up to 1 year. This instrument measures a 1- to 70-foot range of water levels. These water-level data can be retrieved through use of a commercially available portable microcomputer. The R200 Downhole Recorder was developed at the U.S. Geological Survey 's Hydrologic Instrumentation Facility, Stennis Space Center, Mississippi. This operating manual describes the R200 Downhole Recorder, provides initial set-up instructions, and gives directions for on-site operation. Design specifications and routine maintenance steps are included. The R200 data-retriever program is a user-friendly, menu-driven program. The manual guides the user through the procedures required to perform specific operations. Numerous screens are reproduced in the text with a discussion of user input for desired responses. Help is provided for specific problems. (USGS)

  10. Development of a High-Pressure/High-Temperature Downhole Turbine Generator

    SciTech Connect

    Timothy F. Price

    2007-02-01

    The objective of this project as originally outlined has been to achieve a viable downhole direct current (DC) power source for extreme high pressure, high temperature (HPHT) environments of >25,000 psi and >250 C. The Phase I investigation posed and answered specific questions about the power requirements, mode of delivery and form factor the industry would like to see for downhole turbine generator tool for the HPHT environment, and noted specific components, materials and design features of that commercial system that will require upgrading to meet the HPHT project goals. During the course of Phase I investigation the scope of the project was HPHT downhole DC power. Phase I also investigated the viability of modifying a commercial expanded, without additional cost expected to the project, to include the addition of HT batteries to the power supply platform.

  11. Apparatus and method for compensating for clock drift in downhole drilling components

    DOEpatents

    Hall, David R.; Pixton, David S.; Johnson, Monte L.; Bartholomew, David B.; Hall, Jr., H. Tracy

    2007-08-07

    A precise downhole clock that compensates for drift includes a prescaler configured to receive electrical pulses from an oscillator. The prescaler is configured to output a series of clock pulses. The prescaler outputs each clock pulse after counting a preloaded number of electrical pulses from the oscillator. The prescaler is operably connected to a compensator module for adjusting the number loaded into the prescaler. By adjusting the number that is loaded into the prescaler, the timing may be advanced or retarded to more accurately synchronize the clock pulses with a reference time source. The compensator module is controlled by a counter-based trigger module configured to trigger the compensator module to load a value into the prescaler. Finally, a time-base logic module is configured to calculate the drift of the downhole clock by comparing the time of the downhole clock with a reference time source.

  12. Single molecule study of a processivity clamp sliding on DNA

    SciTech Connect

    Laurence, T A; Kwon, Y; Johnson, A; Hollars, C; O?Donnell, M; Camarero, J A; Barsky, D

    2007-07-05

    Using solution based single molecule spectroscopy, we study the motion of the polIII {beta}-subunit DNA sliding clamp ('{beta}-clamp') on DNA. Present in all cellular (and some viral) forms of life, DNA sliding clamps attach to polymerases and allow rapid, processive replication of DNA. In the absence of other proteins, the DNA sliding clamps are thought to 'freely slide' along the DNA; however, the abundance of positively charged residues along the inner surface may create favorable electrostatic contact with the highly negatively charged DNA. We have performed single-molecule measurements on a fluorescently labeled {beta}-clamp loaded onto freely diffusing plasmids annealed with fluorescently labeled primers of up to 90 bases. We find that the diffusion constant for 1D diffusion of the {beta}-clamp on DNA satisfies D {le} 10{sup -14} cm{sup 2}/s, much slower than the frictionless limit of D = 10{sup -10} cm{sup 2}/s. We find that the {beta} clamp remains at the 3-foot end in the presence of E. coli single-stranded binding protein (SSB), which would allow for a sliding clamp to wait for binding of the DNA polymerase. Replacement of SSB with Human RP-A eliminates this interaction; free movement of sliding clamp and poor binding of clamp loader to the junction allows sliding clamp to accumulate on DNA. This result implies that the clamp not only acts as a tether, but also a placeholder.

  13. 33 CFR 183.532 - Clips, straps, and hose clamps.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Clips, straps, and hose clamps... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.532 Clips, straps, and hose clamps. (a) Each clip, strap, and hose clamp must: (1) Be made from a...

  14. 33 CFR 183.532 - Clips, straps, and hose clamps.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Clips, straps, and hose clamps... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.532 Clips, straps, and hose clamps. (a) Each clip, strap, and hose clamp must: (1) Be made from a...

  15. Pulse communication technology enables remote actuation and manipulation of downhole completion equipment in extended reach and deepwater applications

    SciTech Connect

    Hopmann, M.; Smith, M.

    1996-12-31

    Pulse frequency communication techniques have been employed to remotely actuate electronically enhanced downhole completion tools. In extended-reach and deepwater applications, remote actuation systems based on pulse technology reduce rig time and costs required to actuate downhole completion tools, and eliminate the risks associated with conventionally actuated completions which require invasive well intervention.

  16. Damping mechanisms of single-clamped and prestressed double-clamped resonant polymer microbeams

    NASA Astrophysics Data System (ADS)

    Schmid, S.; Hierold, C.

    2008-11-01

    In this article, an investigation of the damping mechanisms of resonant single- and double-clamped polymer microbeams for a frequency range from 10 kHz to 5 MHz is presented. The suspended structures are made of SU-8, an epoxy-type photoresist, by means of a sacrificial layer technique. The vibration was measured with a laser-Doppler vibrometer in high vacuum at different temperatures and at atmospheric pressure. The influence of air damping in rarefied air was investigated and the intrinsic damping mechanisms were determined in high vacuum (p <0.05 Pa). After excluding a variety of possible damping factors, the dominant intrinsic dissipation mechanism of the single-clamped microbeams was understood to be the material damping with maximum quality factors (Q) of around 70 at 20 °C. Quality factors of up to 720 at 20 °C were measured for stringlike double-clamped microbeams, which suggest a different intrinsic damping mechanism than material loss. It is shown that internal damping mechanisms due to flexure and elongation have a small impact on the damping of stretched strings. Modeling the clamping loss based on the wave transmission into the suspended anchor plates indicates that it is the dominant intrinsic dissipation in the prestressed double-clamped microresonators. At atmospheric pressure it was shown that at low frequencies the quality factors of single-clamped and stringlike double-clamped microbeams are limited by the squeeze-film air damping. At high frequencies the quality factors are limited by the specific intrinsic damping. In between the two particular regions with a specific dominant damping mechanism the quality factors show a maximum.

  17. Development of a High Pressure/High Temperature Down-hole Turbine Generator

    SciTech Connect

    Ben Plamp

    2008-06-30

    As oil & natural gas deposits become more difficult to obtain by conventional means, wells must extend to deeper more heat-intensive environments. The technology of the drilling equipment required to reach these depths has exceeded the availability of electrical power sources needed to operate these tools. Historically, logging while drilling (LWD) and measure while drilling (MWD) devices utilized a wireline to supply power and communication from the operator to the tool. Lithium ion batteries were used in scenarios where a wireline was not an option, as it complicated operations. In current downhole applications, lithium ion battery (LIB) packs are the primary source for electrical power. LIB technology has been proven to supply reliable downhole power at temperatures up to 175 °C. Many of the deeper well s reach ambient temperatures above 200 °C, creating an environment too harsh for current LIB technology. Other downfalls of LIB technology are cost, limitations on charge cycles, disposal issues and possible safety hazards including explosions and fires. Downhole power generation can also be achieved by utilizing drilling fluid flow and converting it to rotational motion. This rotational motion can be harnessed to spin magnets around a series of windings to produce power proportional to the rpm experienced by the driven assembly. These generators are, in most instances, driven by turbine blades or moyno-based drilling fluid pumps. To date, no commercially available downhole power generators are capable of operating at ambient temperatures of 250 °C. A downhole power g enerator capable of operation in a 250 °C and 20,000 psi ambient environment will be an absolute necessity in the future. Dexter Magnetic Technologies’ High-Pressure High-Temperature (HPHT) Downhole Turbine Generator is capable of operating at 250 °C and 20, 000 psi, but has not been tested in an actual drilling application. The technology exists, but to date no company has been willing to

  18. NATO-3C/Delta launch

    NASA Technical Reports Server (NTRS)

    1978-01-01

    NATO-3C, the third in a series of NATO defense-related communication satellites, is scheduled to be launched on a delta vehicle from the Eastern Test Range no earlier than November 15, 1978. NATO-3A and -3B were successfully launched by Delta vehicles in April 1976 and January 1977, respectively. The NATO-3C spacecraft will be capable of transmitting voice, data, facsimile, and telex messages among military ground stations. The launch vehicle for the NATO-3C mission will be the Delta 2914 configuration. The launch vehicle is to place the spacecraft in a synchronous transfer orbit. The spacecraft Apogee Kick motor is to be fired at fifth transfer orbit apogee to circularize its orbit at geosynchronous altitude of 35,900 km(22,260 miles) above the equator over the Atlantic Ocean somewhere between 45 and 50 degrees W longitude.

  19. Downhole pressure, temperature and flowrate measurements in steam wells at the Geysers field

    SciTech Connect

    Enedy, Kathleen L.

    1988-01-01

    Recently developed pressure-temperature-spinner (PTS) tools are used to collect reliable downhole measurements in geothermal systems, such as at The Geysers. PTS surveys in several flowing Geysers steam wells were used to quantify steam entry location and magnitude, wellbore heat loss, pressure drop due to friction, thermodynamic properties of the steam, and maximum rock temperature. Interwell cross flow/interference was identified in one well. Finally, a single-phase saturated steam wellbore model used to compare calculated to measured downhole values, was found to adequately predict the flowing pressure versus depth curves in vapor filled holes.

  20. EGRET observations of 3C 273

    NASA Technical Reports Server (NTRS)

    Von Montigny, C.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mattox, J. R.

    1993-01-01

    The quasar 3C 273 was detected by COS-B in the 1970's. EGRET observations of this sky region in June and October 1991 revealed a flux from 3C 273 lower than that measured by COS-B. The flux observed by EGRET in the June period is approximately 3 x 10 exp -7/sq cm s for energies greater than 100 MeV. During the October observation it appears to be even lower. For the first observation a preliminary spectrum which has a photon index of 2.4 has been derived.

  1. EGRET observations of 3 C 273

    NASA Technical Reports Server (NTRS)

    Vonmontigny, C.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mattox, J. R.

    1992-01-01

    The quasar 3C 273 was detected by the Compton Observatory Satellite (COS-B) in the 1970's. Energetic Gamma Ray Experiment Telescope (EGRET) observations of this sky region in Jun. and Oct. 1991 revealed a flux from 3C 273 lower than that measured by COS-B. The flux observed by EGRET in the June period is approximately 0.0000003/sq cm(exp -2) sec(exp -1) for energies greater than 100 MeV. During the Oct. observation it appears to be even lower. For the first observation a preliminary spectrum was derived which was a photon index of 2.4.

  2. EGRET observations of 3C 273

    NASA Technical Reports Server (NTRS)

    Von Montigny, C.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mattox, J. R.

    1993-01-01

    The quasar 3C 273 was detected by COS-B in the 1970's. EGRET observations of this sky region in June and October 1991 revealed a flux from 3C 273 lower than that measured by COS-B. The flux observed by EGRET in the June period is approximately 3 x 10 exp -7/sq cm s for energies greater than 100 MeV. During the October observation it appears to be even lower. For the first observation a preliminary spectrum which has a photon index of 2.4 has been derived.

  3. Timing of umbilical cord clamping of term infants.

    PubMed

    Ceriani Cernadas, José María

    2017-04-01

    For at least over 200 years, multiple controversies have arisen around the timing of umbilical cord clamping. In the past decades, early cord clamping (within the first 15 seconds) had markedly prevailed. Only in the 21st century, randomized controlled trials have demonstrated the benefits of delayed cord clamping (at 2-3 minutes). Delayed cord clamping has been practiced in obstetrics based on the recommendations made by scientific societies and in systematic reviews, which have provided solid evidence to support this practice in term infants. This review describes the most relevant factors supporting the use of delayed cord clamping in term infants. It points out the essential role played by physiological mechanisms which, undoubtedly, allow us to understand the benefits of delayed cord clamping and advise us to wait for what nature has established. Other relevant aspects supporting delayed cord clamping are also described here. Sociedad Argentina de Pediatría.

  4. Testing and evaluation of stretching strain in clamped-clamped beams for energy harvesting

    NASA Astrophysics Data System (ADS)

    Emad, Ahmed; Mahmoud, Mohamed A. E.; Ghoneima, Maged; Dessouky, Mohamed

    2016-11-01

    In this paper, evaluation of stretching strain capabilities to harvest energy from a piezoelectric clamped-clamped beam is theoretically modeled and experimentally tested. The utilization of stretching strain has many advantages as: elimination of any substrate material, and the simple electrode configuration. The doubly clamped structure exhibits a highly nonlinear frequency response (Hardening Duffing) that widens the bandwidth during the frequency up-ward sweep. The wide bandwidth makes it suitable for practical applications. A design of 53.5 {{mm}}3 (29.7 {{mm}}3 piezoelectric material + 23.8 {{mm}}3 proof mass) energy harvester was tested using PVDF (polyvinylidene fluoride) that can generate up to 15 μW from vibrations of 0.5{g} at 128 {Hz} and 2 MΩ load. The design can also generate up to 41 μ {{W}} from vibrations of 1{g} at 140 {Hz} and 2 MΩ load.

  5. Whole-GUV patch-clamping.

    PubMed

    Garten, Matthias; Mosgaard, Lars D; Bornschlögl, Thomas; Dieudonné, Stéphane; Bassereau, Patricia; Toombes, Gilman E S

    2017-01-10

    Studying how the membrane modulates ion channel and transporter activity is challenging because cells actively regulate membrane properties, whereas existing in vitro systems have limitations, such as residual solvent and unphysiologically high membrane tension. Cell-sized giant unilamellar vesicles (GUVs) would be ideal for in vitro electrophysiology, but efforts to measure the membrane current of intact GUVs have been unsuccessful. In this work, two challenges for obtaining the "whole-GUV" patch-clamp configuration were identified and resolved. First, unless the patch pipette and GUV pressures are precisely matched in the GUV-attached configuration, breaking the patch membrane also ruptures the GUV. Second, GUVs shrink irreversibly because the membrane/glass adhesion creating the high-resistance seal (>1 GΩ) continuously pulls membrane into the pipette. In contrast, for cell-derived giant plasma membrane vesicles (GPMVs), breaking the patch membrane allows the GPMV contents to passivate the pipette surface, thereby dynamically blocking membrane spreading in the whole-GMPV mode. To mimic this dynamic passivation mechanism, beta-casein was encapsulated into GUVs, yielding a stable, high-resistance, whole-GUV configuration for a range of membrane compositions. Specific membrane capacitance measurements confirmed that the membranes were truly solvent-free and that membrane tension could be controlled over a physiological range. Finally, the potential for ion transport studies was tested using the model ion channel, gramicidin, and voltage-clamp fluorometry measurements were performed with a voltage-dependent fluorophore/quencher pair. Whole-GUV patch-clamping allows ion transport and other voltage-dependent processes to be studied while controlling membrane composition, tension, and shape.

  6. Patch Clamping Protoplasts from Vascular Plants 1

    PubMed Central

    Elzenga, J. Theo M.; Keller, Christopher P.; Van Volkenburgh, Elizabeth

    1991-01-01

    A method is described for the isolation of protoplasts (Pisum sativum, Phaseolus vulgaris, Avena sativa, Arabidopsis thaliana) in preparation for ion flux studies using patch clamp electrophysiology. Protoplasts that have been exposed to hydrolytic, cell wall degrading, enzymes for as little as 5 minutes form gigaseals (seal resistance higher than 10 giga Ohm) with the patch pipette with success rates greater than 40%. Sealing of these protoplasts is fast, averaging less than 2 minutes. This method yields high rates of gigaseal formation in a variety of tissues from both monocots and dicots and will enhance data collection in ion flux studies of plasma membranes of vascular plants. PMID:16668586

  7. The Clamp Loader Assembles the β Clamp onto Either a 3′ or 5′ Primer Terminus

    PubMed Central

    Park, Mee Sook; O'Donnell, Mike

    2009-01-01

    Clamp loaders assemble sliding clamps onto 3′ primed sites for DNA polymerases. Clamp loaders are thought to be specific for a 3′ primed site, and unable to bind a 5′ site. We demonstrate here that the Escherichia coli γ complex clamp loader can load the β clamp onto a 5′ primed site, although with at least 20-fold reduced efficiency relative to loading at a 3′ primed site. Preferential clamp loading at a 3′ site does not appear to be due to DNA binding, as the clamp loader forms an avid complex with β at a 5′ site. Preferential loading at a 3′ versus a 5′ site occurs at the ATP hydrolysis step, needed to close the ring around DNA. We also address DNA structural features that are recognized for preferential loading at a 3′ site. Although the single-stranded template strand extends in opposite directions from 3′ and 5′ primed sites, thus making it a favorite candidate for distinguishing between 3′ and 5′ sites, the single-strand polarity at a primed template junction does not determine 3′ site selection for clamp loading. Instead, we find that clamp loader recognition of a 3′ site lies in the duplex portion of the primed site, not the single-strand portion. We present evidence that the β clamp facilitates its own loading specificity for a 3′ primed site. Implications to eukaryotic clamp loader complexes are proposed. PMID:19759020

  8. Downhole geothermal well sensors comprising a hydrogen-resistant optical fiber

    DOEpatents

    Weiss, Jonathan D.

    2005-02-08

    A new class of optical fiber based thermal sensors has been invented. The new sensors comprise hydrogen-resistant optical fibers which are able to withstand a hot, hydrogen-containing environment as is often found in the downhole well environment.

  9. Update of comparative analysis of steam delivery costs for surface and downhole steam drive technologies

    SciTech Connect

    Hart, C.M.; Muir, J.F.

    1984-04-01

    A review and update is presented of a previous analysis which compared the economic performance of the surface and downhole steam delivery technologies investigated in the Department of Energy's Project DEEP STEAM for the enhanced recovery of heavy oil from deep reservoirs. Emphasis is placed on an examination and revision of the compression and wellbore heat loss assumptions and their effects on sandface steam delivery costs. Multistage compression with intercooling and aftercooling, increased overall compression efficiency, and waste heat scavenging all serve to decrease the cost of steam generated downhole and reduce differences among the various surface and downhole delivery system costs. Wellbore heat loss increases dramatically when water is present in the annulus, causing a reduction in the depth to which surface steaming is effective and an increase in steam delivery costs. Other concerns potentially impacting the cost comparisons are discussed. These include: crude versus diesel generator fuel, reliability of both surface and downhole hardware, capital equipment costs, surface transmission losses, and the assumption of hydrostatic reservoir pressure. 16 references, 19 figures, 1 table.

  10. Applications of optical fiber sensors in subsea and downhole oil well environments

    NASA Astrophysics Data System (ADS)

    Mendez, Alexis; Dalziel, Rob; Douglas, Neil

    1999-12-01

    In this paper, an overview on the use of optical fiber sensor in subsea and downhole oil well and related applications is presented, along with the impact of this technology in the oil industry. Focus will be placed on identifying the needs and requirements for various sensing applications.

  11. 30 CFR 250.1158 - How do I receive approval to downhole commingle hydrocarbons?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... hydrocarbons? 250.1158 Section 250.1158 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND... approval to downhole commingle hydrocarbons? (a) Before you perforate a well, you must request and receive approval from the Regional Supervisor to commingle hydrocarbons produced from multiple reservoirs within a...

  12. 30 CFR 250.1158 - How do I receive approval to downhole commingle hydrocarbons?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... hydrocarbons? 250.1158 Section 250.1158 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT... downhole commingle hydrocarbons? (a) Before you perforate a well, you must request and receive approval from the Regional Supervisor to commingle hydrocarbons produced from multiple reservoirs within a...

  13. 30 CFR 250.1158 - How do I receive approval to downhole commingle hydrocarbons?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... hydrocarbons? 250.1158 Section 250.1158 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT... downhole commingle hydrocarbons? (a) Before you perforate a well, you must request and receive approval from the Regional Supervisor to commingle hydrocarbons produced from multiple reservoirs within a...

  14. 30 CFR 250.1158 - How do I receive approval to downhole commingle hydrocarbons?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... hydrocarbons? 250.1158 Section 250.1158 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT... downhole commingle hydrocarbons? (a) Before you perforate a well, you must request and receive approval from the Regional Supervisor to commingle hydrocarbons produced from multiple reservoirs within a...

  15. A downhole passive sampling system to avoid bias and error from groundwater sample handling.

    PubMed

    Britt, Sanford L; Parker, Beth L; Cherry, John A

    2010-07-01

    A new downhole groundwater sampler reduces bias and error due to sample handling and exposure while introducing minimal disturbance to natural flow conditions in the formation and well. This "In Situ Sealed", "ISS", or "Snap" sampling device includes removable/lab-ready sample bottles, a sampler device to hold double end-opening sample bottles in an open position, and a line for lowering the sampler system and triggering closure of the bottles downhole. Before deployment, each bottle is set open at both ends to allow flow-through during installation and equilibration downhole. Bottles are triggered to close downhole without well purging; the method is therefore "passive" or "nonpurge". The sample is retrieved in a sealed condition and remains unexposed until analysis. Data from six field studies comparing ISS sampling with traditional methods indicate ISS samples typically yield higher volatile organic compound (VOC) concentrations; in one case, significant chemical-specific differentials between sampling methods were discernible. For arsenic, filtered and unfiltered purge results were negatively and positively biased, respectively, compared to ISS results. Inorganic constituents showed parity with traditional methods. Overall, the ISS is versatile, avoids low VOC recovery bias, and enhances reproducibility while avoiding sampling complexity and purge water disposal.

  16. Development of wireless downhole pressure and temperature telemetry tool. Annual report, April 1992-April 1993

    SciTech Connect

    Guest, R.; Esfahani, F.; Dennis, J.

    1993-05-01

    The objective is to develop a wireless downhole telemetry system capable of gathering and transmitting pressure and temperature data from the bottom of a borehole to the surface. The specific objective is to determine the technical feasibility and to develop an electromagnetic telemetry system.

  17. Downhole tool apparatus with non-metallic components and methods of drilling thereof

    SciTech Connect

    Streich, S.G.; Hushbeck, D.F.; Berscheidt, K.T.; Jacobi, R.D.

    1993-07-06

    A downhole apparatus is described for use in a well bore, said apparatus comprising: a center mandrel; and slip means disposed on said mandrel for grippingly engaging said well bore when in a set position, said slip means being at least partially made of a non-metallic material.

  18. Enhanced Oil Recovery with Downhole Vibration Stimulation in Osage County Oklahoma

    SciTech Connect

    J. Ford Brett; Robert V. Westermark

    2001-03-31

    The objective of this project is to demonstrate the impact of downhole vibration stimulation on oil production rates in a mature waterflood field. Oil & Gas Consultants International, Inc. (OGCI) will manage the project in close cooperation with the Osage Tribe as the tests will be conducted in Osage County, Oklahoma, the mineral estate of the Osage Tribe. The field is owned and operated by Calumet Oil Company. Phillips Petroleum Company will contribute their proprietary vibration core analysis of cores recovered from the pilot test area. To achieve the project objectives, the work has been divided into nine tasks, some are concurrent, while other tasks rely on completion of previous steps. The operator, Calumet Oil Company operates several field in Osage County Oklahoma. The North Burbank Unit will be the site of the test. The team will then determine where within the field to optimally locate the vibration test well. With the location determined, the test well will be drilled, cored, logged and 7-inch production casing run and cemented. In a parallel effort, OGCI will be designing, building, and testing a new version of the downhole vibration tool based on their patented and field proven whirling orbital vibrator. With the field test tool built to run in 7-inch casing. Reliability testing of the downhole tool and surface power source will be conducted in nearby field operated by Calumet Oil Company. After the core is recovered, Phillips Petroleum Company will be conducting laboratory tests utilizing their proprietary sonic core apparatus to determine fluid flow response to a range of vibration frequencies. These results, in turn, will allow final adjustments to the frequency generation mechanisms of the downhole vibration tool. One or more offset wells, near to the vibration test well, will be equipped with downhole geophones and or hydro-phones to determine the strength of signal and if the producing formation has a characteristic resonant frequency response

  19. Laser-assisted patch clamping: a methodology

    NASA Technical Reports Server (NTRS)

    Henriksen, G. H.; Assmann, S. M.; Evans, M. L. (Principal Investigator)

    1997-01-01

    Laser microsurgery can be used to perform both cell biological manipulations, such as targeted cell ablation, and molecular genetic manipulations, such as genetic transformation and chromosome dissection. In this report, we describe a laser microsurgical method that can be used either to ablate single cells or to ablate a small area (1-3 microns diameter) of the extracellular matrix. In plants and microorganisms, the extracellular matrix consists of the cell wall. While conventional patch clamping of these cells, as well as of many animal cells, requires enzymatic digestion of the extracellular matrix, we illustrate that laser microsurgery of a portion of the wall enables patch clamp access to the plasma membrane of higher plant cells remaining situated in their tissue environment. What follows is a detailed description of the construction and use of an economical laser microsurgery system, including procedures for single cell and targeted cell wall ablation. This methodology will be of interest to scientists wishing to perform cellular or subcellular ablation with a high degree of accuracy, or wishing to study how the extracellular matrix affects ion channel function.

  20. Laser-assisted patch clamping: a methodology

    NASA Technical Reports Server (NTRS)

    Henriksen, G. H.; Assmann, S. M.; Evans, M. L. (Principal Investigator)

    1997-01-01

    Laser microsurgery can be used to perform both cell biological manipulations, such as targeted cell ablation, and molecular genetic manipulations, such as genetic transformation and chromosome dissection. In this report, we describe a laser microsurgical method that can be used either to ablate single cells or to ablate a small area (1-3 microns diameter) of the extracellular matrix. In plants and microorganisms, the extracellular matrix consists of the cell wall. While conventional patch clamping of these cells, as well as of many animal cells, requires enzymatic digestion of the extracellular matrix, we illustrate that laser microsurgery of a portion of the wall enables patch clamp access to the plasma membrane of higher plant cells remaining situated in their tissue environment. What follows is a detailed description of the construction and use of an economical laser microsurgery system, including procedures for single cell and targeted cell wall ablation. This methodology will be of interest to scientists wishing to perform cellular or subcellular ablation with a high degree of accuracy, or wishing to study how the extracellular matrix affects ion channel function.

  1. Multifrequency observations of extended radio galaxies V - 3C 31, 3C 33.1, 3C 35, 3C 66B, 3C 129, 3C 130, 3C 223, 3C 310, 3C 390.3 and 4C 48.29

    NASA Astrophysics Data System (ADS)

    van Breugel, W.; Jagers, W.

    1982-08-01

    A sample of 3C radio sources of large angular size has been observed in total and polarized intensity at several wavelengths with the Westerbork Synthesis Radio Telescope. The sources were selected such that their largest angular size was greater than about 200 arcsec and their declination greater than about 25 degrees. Some additional sources with radio jets or peculiar morphology were also included. The name of each source, its structural type classification, wavelength of observation, and data references are given.

  2. Spectral infrared hemispherical reflectance measurements for LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Cromwell, B. K.; Shepherd, S. D.; Pender, C. W.; Wood, B. E.

    1993-01-01

    Infrared hemispherical reflectance measurements that were made on 58 chromic acid anodized tray clamps from LDEF are described. The measurements were made using a hemiellipsoidal mirror reflectometer with interferometer for wavelengths between 2-15 microns. The tray clamps investigated were from locations about the entire spacecraft and provided the opportunity for comparing the effects of atomic oxygen at each location. Results indicate there was essentially no dependence on atomic oxygen fluence for the surfaces studied, but there did appear to be a slight dependence on solar radiation exposure. The reflectances of the front sides of the tray clamps consistently were slightly higher than for the protected rear tray clamp surfaces.

  3. An Optimal Cell Detection Technique for Automated Patch Clamping

    NASA Technical Reports Server (NTRS)

    McDowell, Mark; Gray, Elizabeth

    2004-01-01

    While there are several hardware techniques for the automated patch clamping of cells that describe the equipment apparatus used for patch clamping, very few explain the science behind the actual technique of locating the ideal cell for a patch clamping procedure. We present a machine vision approach to patch clamping cell selection by developing an intelligent algorithm technique that gives the user the ability to determine the good cell to patch clamp in an image within one second. This technique will aid the user in determining the best candidates for patch clamping and will ultimately save time, increase efficiency and reduce cost. The ultimate goal is to combine intelligent processing with instrumentation and controls in order to produce a complete turnkey automated patch clamping system capable of accurately and reliably patch clamping cells with a minimum amount of human intervention. We present a unique technique that identifies good patch clamping cell candidates based on feature metrics of a cell's (x, y) position, major axis length, minor axis length, area, elongation, roundness, smoothness, angle of orientation, thinness and whether or not the cell is only particularly in the field of view. A patent is pending for this research.

  4. Delayed cord clamping and cord gas analysis at birth.

    PubMed

    Xodo, Serena; Xodo, Luigi; Berghella, Vincenzo

    2017-09-16

    Delayed cord clamping for at least 60 seconds in both term and preterm babies is a major recent change in clinical care. Delayed cord clamping has several effects on other possible interventions. One of these is the effect of delayed cord clamping on umbilical artery gas analysis. When indicated, umbilical artery gas analysis can safely be done either with early cord clamping, or, probably most of the times it is necessary, during delayed cord clamping with the cord still unclamped. Paired blood samples (one from the umbilical artery and one from the umbilical vein) can be taken from the pulsating and unclamped cord, immediately after birth, during delayed cord clamping, without any effect on either the accuracy of umbilical artery gas analysis or on the transfusion of blood through delayed cord clamping. Umbilical artery gas analysis should instead not be done after delayed cord clamping, since delayed cord clamping alters several acid-based parameters and lactate values. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  5. Obstetricians' attitudes and beliefs regarding umbilical cord clamping.

    PubMed

    Jelin, Angie C; Kuppermann, Miriam; Erickson, Kristine; Clyman, Ronald; Schulkin, Jay

    2014-09-01

    Although delayed umbilical cord clamping has been demonstrated to reduce the incidence of intraventricular hemorrhage and neonatal sepsis, and decrease the need for neonatal transfusions (without affecting cord pH, Apgar scores or the need for phototherapy), the extent to which this practice is being employed is unknown. We conducted a survey of US obstetricians to assess their attitudes and beliefs about cord clamping. Questionnaires were randomly mailed to members of the American College of Obstetricians and Gynecologists (ACOG), and the Collaborative Ambulatory Research Network (CARN). The data were analyzed using Chi-square and Student t tests. The response rates for the CARN and other ACOG members were 47% and 21%, respectively. Most (88%) responders reported their hospital had no umbilical cord clamping policy. The most frequent response for optimal timing of umbilical cord clamping, regardless of gestational age, was "don't know". Potential for neonatal red blood cell transfusion was the only concern cited as a reason for being somewhat or very inclined to delay umbilical cord clamping (51%). Delayed neonatal resuscitation (76%) was listed as a reason to clamp the cord immediately, despite the paucity of literature to support immediate cord clamping in this cohort. Despite substantial evidence supporting the practice of delayed cord clamping, few institutions have policies regarding this practice. Moreover, obstetricians' beliefs about the appropriate timing for umbilical cord clamping are not consistent with the evidence that demonstrates its beneficial impact on neonatal outcomes.

  6. Re-visiting the trans insertion model for complexin clamping

    PubMed Central

    Krishnakumar, Shyam S; Li, Feng; Coleman, Jeff; Schauder, Curtis M; Kümmel, Daniel; Pincet, Frederic; Rothman, James E; Reinisch, Karin M

    2015-01-01

    We have previously proposed that complexin cross-links multiple pre-fusion SNARE complexes via a trans interaction to function as a clamp on SNARE-mediated neurotransmitter release. A recent NMR study was unable to detect the trans clamping interaction of complexin and therefore questioned the previous interpretation of the fluorescence resonance energy transfer and isothermal titration calorimetry data on which the trans clamping model was originally based. Here we present new biochemical data that underscore the validity of our previous interpretation and the continued relevancy of the trans insertion model for complexin clamping. DOI: http://dx.doi.org/10.7554/eLife.04463.001 PMID:25831964

  7. Long term variability of 3C279

    NASA Technical Reports Server (NTRS)

    Grandi, P.; Maraschi, L.; Urry, C. M.; Wehrle, A. E.; Aller, M. F.; Aller, H. D.; Balonek, T. J.; Jason, J.; Mchardy, I. M.; Hartman, R. C.

    1995-01-01

    Radio, mm, optical, UV and X-ray light curves of 3C 279 as well as the gamma-ray light curve available since 1991 June are considered. Strong flux correlations are found between the X-ray and the radio-optical region. Variations at 100 MeV are well correlated to the optical and X-ray bands. The variability amplitude, as measured by an average logarithmic dispersion of the available measurements is small in the radio and increases systematically with increasing frequency up to the gamma-ray band, with the possible exception of the X-ray amplitude.

  8. ALMA Polarization Science Verification: 3C 286

    NASA Astrophysics Data System (ADS)

    Nagai, H.; Nakanishi, K.; Paladino, R.; Moellenbrock, G.; Fomalont, E.; Amigano, A.; Vlahakis, C.; Remijan, A.; ALMA Polarization Team

    2015-12-01

    The ALMA polarization science verification results on 3C 286 are presented. The measured polarization percentage and polarization position angle of the continuum emission at 1.3 mm are about 16% and 39 degrees, respectively. They are quite similar to those at longer wavelength, but seem to increase slightly. Similar trends were also found in the previous measurement using the IRAM 30-m telescope (Agudo et al. 2012). The final image rms on the polarization image is better than 0.1% of the total intensity, demonstrating the very high polarization sensitivity of ALMA.

  9. Thermal stiffening of clamped elastic ribbons

    NASA Astrophysics Data System (ADS)

    Wan, Duanduan; Nelson, David R.; Bowick, Mark J.

    2017-07-01

    We use molecular dynamics to study the vibrations of a thermally fluctuating two-dimensional elastic membrane clamped at both ends. We directly extract the eigenmodes from resonant peaks in the frequency domain of the time-dependent height and measure the dependence of the corresponding eigenfrequencies on the microscopic bending rigidity of the membrane, taking care also of the subtle role of thermal contraction in generating a tension when the projected area is fixed. At finite temperatures we show that the effective (macroscopic) bending rigidity tends to a constant as the bare bending rigidity vanishes, consistent with theoretical arguments that the large-scale bending rigidity of the membrane arises from a strong thermal renormalization of the microscopic bending rigidity. Experimental realizations include covalently bonded two-dimensional atomically thin membranes such as graphene and molybdenum disulfide or soft matter systems such as the spectrin skeleton of red blood cells or diblock copolymers.

  10. Nanoindentation characteristics of clamped freestanding Cu membranes.

    PubMed

    Wang, Tong Hong; Fang, Te-Hua; Kang, Shao-Hui; Lin, Yu-Cheng

    2007-04-04

    This research employed instrumented nanoindentation to address the issue of bending to stretching-induced deformation of clamped freestanding Cu membranes. The experimental results show that indentation-induced plastic deformation only comes into effect at the centre and the indented edge of the Cu membrane when the indenter is applied, while the other locations remain undamaged. A step-by-step evolution was presumed for the time histories of the bending to stretching-induced deformation and for the timing of the significant change in slope of the load-deflection curve. Deformation was deliberately introduced at the transition from the single-point bending indentation to the surface stretching indentation at the impact location touched with the indenter. Good elastic recovery was found at locations away from the indenter. A similar finding can be arrived at by means of finite element analysis.

  11. Pipe lifting hook having clamp assembly

    SciTech Connect

    Codner, J.A.

    1984-06-12

    A pipe lifting hook is provided having a generally ''C'' shaped hook member having an elongated lower portion being insertable within the end of a joint of pipe and having an upper portion positionable above the pipe and provided with lifting connection means. The hook member is frictionally clamped to the pipe by grip shoe means that is movably supported by the upper portion of the hook member and is selectably movable from a released position out of contact with said pipe to a locked position in frictional locking engagement with the outer surface of the pipe. A ratchet mechanism couples said grip shoe means to the upper portion of the hook member and is manually positionable to lock said grip shoe means at said locked position or release said grip shoe means for movement toward said released position thereof.

  12. Structure of the radio sources 3C 196 and 3C 280

    SciTech Connect

    Bovkun, V.; Zhuk, I.; Men', A.

    1981-05-01

    The structure of the quasar 3C 196 and the radio galaxy 3C 280 at 20- and 25-MHz frequency has been surveyed by the scintillation technique with the URAN-1 interferometer. Angular sizes are estimated for the scintillating components and the extended portions of each source. In 3C 196 these components have effective angular sizes of 2'' +- 1''.5 and 18'' x 25'', with the compact feature contributing 0.46 +- 0.20 of the total flux. Spectra of the various structural components of the source are compiled for the range 20--5000 MHz. In 3C 280 the effective angular size of the scintillating component is 1''.5 +- 1''.2; the extended region measures >10'' across. The compact feature contributes 0.35 +- 0.20 of the total flux.

  13. CHANDRA Observations OF The Shock Heated Gas Around 3c 288 And 3c 449

    NASA Astrophysics Data System (ADS)

    Lal, Dharam V.; Kraft, R. P.; Evans, D. A.; Hardcastle, M. J.; Nulsen, P. E. J.; Croston, J. H.; Forman, W. R.; Jones, C.; Lee, J. C.

    2010-03-01

    The inflation of radio bubbles in the hot gas atmospheres of clusters of galaxies plays an important role in the overall energy budget of the ICM. Regular gentle (i.e. subsonic) nuclear outbursts may be able to provide sufficient energy to the gas in the cool cores of clusters to offset radiative losses and regulate large cooling flows; and one method to supplement the total energy input into the gas is for the lobes to initially drive strong shocks into the gas. We present results from Chandra/ACIS-S observations of the hot gas atmospheres of two powerful, nearby radio galaxies in poor clusters: 3C 288 and 3C 449. We measure the total energy of the current outburst to be a few times 10^{59} ergs for 3C 288 (T = 2.8 keV, L_X = 1.4 × 10^{44} ergs) and ˜10^{58} ergs for 3C 449 (T = 1.5 keV, L_X = 2.0 × 10^{42} ergs). We find multiple surface brightness discontinuities in the gas, which are probably shocks and are indicative of supersonic heating by the inflation of the radio lobe. We do not find X-ray cavity in 3C 288, whereas cavities are associated with both the radio lobes in 3C 449.

  14. The kinetically dominated quasar 3C 418

    NASA Astrophysics Data System (ADS)

    Punsly, Brian; Kharb, Preeti

    2017-06-01

    The existence of quasars that are kinetically dominated, where the jet kinetic luminosity, Q, is larger than the total (infrared to X-ray) thermal luminosity of the accretion flow, Lbol, provides a strong constraint on the fundamental physics of relativistic jet formation. Since quasars have high values of Lbol by definition, only ˜10 kinetically dominated quasars (with \\overline{Q}/L_{bol}>1) have been found, where \\overline{Q} is the long-term time-averaged jet power. We use low-frequency (151 MHz-1.66 GHz) observations of the quasar 3C 418 to determine \\overline{Q}≈ 5.5 ± 1.3 × 10^{46} {erg s^{-1}}. Analysis of the rest-frame ultraviolet spectrum indicates that this equates to 0.57 ± 0.28 times the Eddington luminosity of the central supermassive black hole and \\overline{Q}/L_{bol} ≈ 4.8 ± 3.1, making 3C 418 one of the most kinetically dominated quasars found to date. It is shown that this maximal \\overline{Q}/L_{bol} is consistent with models of magnetically arrested accretion of jet production in which the jet production reproduces the observed trend of a decrement in the extreme ultraviolet continuum as the jet power increases. This maximal condition corresponds to an almost complete saturation of the inner accretion flow with vertical large-scale magnetic flux (maximum saturation).

  15. Downhole well log and core montages from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    USGS Publications Warehouse

    Collett, T.S.; Lewis, R.E.; Winters, W.J.; Lee, M.W.; Rose, K.K.; Boswell, R.M.

    2011-01-01

    The BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well was an integral part of an ongoing project to determine the future energy resource potential of gas hydrates on the Alaska North Slope. As part of this effort, the Mount Elbert well included an advanced downhole geophysical logging program. Because gas hydrate is unstable at ground surface pressure and temperature conditions, a major emphasis was placed on the downhole-logging program to determine the occurrence of gas hydrates and the in-situ physical properties of the sediments. In support of this effort, well-log and core data montages have been compiled which include downhole log and core-data obtained from the gas-hydrate-bearing sedimentary section in the Mount Elbert well. Also shown are numerous reservoir parameters, including gas-hydrate saturation and sediment porosity log traces calculated from available downhole well log and core data. ?? 2010.

  16. Clinical results of minimally invasive mitral valve surgery: endoaortic clamp versus external aortic clamp techniques.

    PubMed

    Ius, Fabio; Mazzaro, Enzo; Tursi, Vincenzo; Guzzi, Giorgio; Spagna, Enrico; Vetrugno, Luigi; Bassi, Flavio; Livi, Ugolino

    2009-11-01

    : This study was carried out with the aim of presenting our experience with minimally invasive mitral surgery and compare the endoaortic clamp with the external aortic clamp (EAC) techniques. : Between December 2002 and May 2009, 139 patients (75 men, aged 63 ± 11 years) underwent video-assisted mitral valve surgery through right thoracotomy. Twelve (9%) patients were operated without clamping the aorta, 32 (23%) patients (group A) were operated on by using the endoaortic clamp, and 95 (68%) patients were operated on by using the EAC (group B). There was no significant difference between groups A and B regarding preoperative variables. : Intraoperative procedure-associated problems were experienced in three group A patients (9.3%, two aortic dissections with conversion to sternotomy; one conversion due to bad exposure) and in two group B patients (2%, one conversion to sternotomy for bleeding and one for ascending aorta hematoma). At a mean follow-up of 32 months, 121 patients (97%) were in New York Heart Association class I-II, with satisfactory echocardiographic results. There was one in-hospital and six late deaths (three noncardiac, two cardiac, and one valve related). Five-year actuarial survival was 88% ± 8%. There were three reoperations, one early (<30 days) after complex mitral valve repair, with a 5-year freedom from reoperation of 97% ± 2%. Postoperative levels of myocardial cytonecrosis enzymes as well as the extracorporeal circulation time were significantly lower in group B patients (P < 0.05). : Intraoperative procedure-associated complications with endoclamping combined with an apparently better myocardial protection forced us to change our practice to the more simple and economic EAC technique.

  17. The PCNA-RFC families of DNA clamps and clamp loaders.

    PubMed

    Majka, Jerzy; Burgers, Peter M J

    2004-01-01

    The proliferating cell nuclear antigen PCNA functions at multiple levels in directing DNA metabolic pathways. Unbound to DNA, PCNA promotes localization of replication factors with a consensus PCNA-binding domain to replication factories. When bound to DNA, PCNA organizes various proteins involved in DNA replication, DNA repair, DNA modification, and chromatin modeling. Its modification by ubiquitin directs the cellular response to DNA damage. The ring-like PCNA homotrimer encircles double-stranded DNA and slides spontaneously across it. Loading of PCNA onto DNA at template-primer junctions is performed in an ATP-dependent process by replication factor C (RFC), a heteropentameric AAA+ protein complex consisting of the Rfc1, Rfc2, Rfc3, Rfc4, and Rfc5 subunits. Loading of yeast PCNA (POL30) is mechanistically distinct from analogous processes in E. coli (beta subunit by the gamma complex) and bacteriophage T4 (gp45 by gp44/62). Multiple stepwise ATP-binding events to RFC are required to load PCNA onto primed DNA. This stepwise mechanism should permit editing of this process at individual steps and allow for divergence of the default process into more specialized modes. Indeed, alternative RFC complexes consisting of the small RFC subunits together with an alternative Rfc1-like subunit have been identified. A complex required for the DNA damage checkpoint contains the Rad24 subunit, a complex required for sister chromatid cohesion contains the Ctf18 subunit, and a complex that aids in genome stability contains the Elg1 subunit. Only the RFC-Rad24 complex has a known associated clamp, a heterotrimeric complex consisting of Rad17, Mec3, and Ddc1. The other putative clamp loaders could either act on clamps yet to be identified or act on the two known clamps.

  18. FULL POLARIZATION SPECTRA OF 3C 279

    SciTech Connect

    Homan, D. C.; Lister, M. L.; Aller, H. D.; Aller, M. F.; Wardle, J. F. C. E-mail: mlister@physics.purdue.edu E-mail: mfa@umich.edu

    2009-05-01

    We report the results of parsec-scale, multifrequency Very Long Baseline Array observations of the core region of 3C 279 in Stokes I, linear polarization, and circular polarization. These full polarization spectra are modeled by radiative transfer simulations to constrain the magnetic field and particle properties of the parsec-scale jet in 3C 279. We find that the polarization properties of the core region, including the amount of linear polarization, the amount and sign of Faraday rotation, and the amount and sign of circular polarization can be explained by a consistent physical picture. The base of the jet, component D, is modeled as an inhomogeneous Blandford-Koenigl style conical jet dominated by a vector-ordered poloidal magnetic field along the jet axis, and we estimate its net magnetic flux. This poloidal field is responsible for the linear and circular polarization from this inhomogeneous component. Farther down the jet, the magnetic field in two homogeneous features is dominated by local shocks and a smaller fraction of vector-ordered poloidal field remains along the jet axis. This remaining poloidal field provides internal Faraday rotation which drives Faraday conversion of linear polarization into circular polarization from these components. In this picture, we find the jet to be kinetically dominated by protons with the radiating particles being dominated by electrons at an approximate fraction of {approx}>75%, still allowing the potential for a significant admixture of positrons. Based on the amounts of Faraday conversion deduced for the homogeneous components, we find a plausible range for the lower cutoff in the relativistic particle energy spectrum to be 5 {approx}< {gamma} {sub l} {approx}< 35. The physical picture described here is not unique if the observed Faraday rotation and depolarization occur in screens external to the jet; however, we find the joint explanation of linear and circular polarization observations from a single set of

  19. Photometric reverberation mapping of 3C 120

    NASA Astrophysics Data System (ADS)

    Pozo Nuñez, F.; Ramolla, M.; Westhues, C.; Bruckmann, C.; Haas, M.; Chini, R.; Steenbrugge, K.; Murphy, M.

    2012-09-01

    We present the results of a five month monitoring campaign of the local active galactic nuclei (AGN) 3C 120. Observations with a median sampling of two days were conducted with the robotic 15 cm telescope VYSOS-6 located near Cerro Armazones in Chile. Broad band (B, V) and narrow band (NB) filters were used in order to measure fluxes of the AGN and the Hβ broad line region (BLR) emission line. The NB flux is constituted by about 50% continuum and 50% Hβ emission line. To disentangle line and continuum flux, a synthetic Hβ light curve was created by subtracting a scaled V-band light curve from the NB light curve. Here we show that the Hβ emission line responds to continuum variations with a rest frame lag of 23.6 ± 1.69 days. We estimate a virial mass of the central black hole MBH = 57 ± 27 × 106 M⊙, by combining the obtained lag with the velocity dispersion of a single contemporaneous spectrum. Using the flux variation gradient method, we determined the host galaxy subtracted rest frame 5100 Å luminosity at the time of our monitoring campaign with an uncertainty of 10% (LAGN = (6.94 ± 0.71) × 1043 erg s-1). Compared with recent spectroscopic reverberation results, 3C 120 shifts in the RBLR - LAGN diagram remarkably close to the theoretically expected relation of R ∝ L0.5. Our results demonstrate the performance of photometric AGN reverberation mapping, in particular for efficiently determining the BLR size and the AGN luminosity. Table 5 is available in electronic form at http://www.aanda.org

  20. Combination Space Station Handrail Clamp and Pointing Device

    NASA Technical Reports Server (NTRS)

    Hughes, Stephen J. (Inventor)

    1999-01-01

    A device for attaching an experiment carrier to a space station handrail is provided. The device has two major components, a clamping mechanism for attachment to a space station handrail, and a pointing carrier on which an experiment package can be mounted and oriented. The handrail clamp uses an overcenter mechanism and the carrier mechanism uses an adjustable preload ball and socket for carrier positioning. The handrail clamp uses a stack of disk springs to provide a spring loaded button. This configuration provides consistent clamping force over a range of possible handrail thicknesses. Three load points are incorporated in the clamping mechanism thereby spreading the clamping load onto three separate points on the handrail. A four bar linkage is used to provide for a single actuation lever for all three load points. For additional safety, a secondary lock consisting of a capture plate and push lock keeps the clamp attached to the handrail in the event of main clamp failure. For the carrier positioning mechanism, a ball in a spring loaded socket uses friction to provide locking torque; however. the ball and socket are torque limited so that the ball ran slip under kick loads (125 pounds or greater). A lead screw attached to disk spring stacks is used to provide an adjustable spring force on the socket. A locking knob is attached to the lead screw to allow for hand manipulation of the lead screw.

  1. OPTIMAL TIMING FOR CLAMPING THE UMBILICAL CORD AFTER BIRTH

    PubMed Central

    Raju, Tonse N. K.; Singal, Nalini

    2013-01-01

    Synopsis This paper provides a brief overview of pros and cons of clamping the cord too early (within seconds) after birth. It also highlights evolving data that suggests that delaying cord clamping for 30–60 seconds after birth is beneficial to the baby and the mother, with no measurable negative effects. PMID:23164185

  2. Nuclear Patch-Clamp Electrophysiology of Ca2+ Channels

    PubMed Central

    Mak, Don-On Daniel; Vais, Horia; Cheung, King-Ho; Foskett, J. Kevin

    2014-01-01

    Patch-clamping the outer or inner nuclear membrane of isolated nuclei is very similar to patch-clamping the plasma membrane of isolated cells. This protocol describes in detail all the steps required to successfully obtain nuclear membrane patches, in various configurations, from both the outer and inner nuclear membranes of isolated nuclei. PMID:24003194

  3. 21 CFR 876.5160 - Urological clamp for males.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Urological clamp for males. 876.5160 Section 876.5160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5160 Urological clamp for males...

  4. 21 CFR 876.5160 - Urological clamp for males.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urological clamp for males. 876.5160 Section 876.5160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5160 Urological clamp for males...

  5. High-Temperature Motor Windings for Downhole Pumps Used in Geothermal Energy Production

    SciTech Connect

    Hooker, Matthew; Hazelton, Craig; Kano, Kimi

    2010-12-31

    The development of highly reliable downhole equipment is an essential element in enabling the widespread utilization of Enhanced Geothermal Systems (EGS). The downhole equipment used in these systems will be required to operate at high voltages and temperatures on the order of 200 to 250°C (and eventually to 300°C). These conditions exceed the practical operating ranges of currently available thermoplastic wire insulations, and thus limit the operating lifetime of tools such as Electric Submersible Pumps (ESPs). In this work, high-temperature insulations based on composite materials were developed and demonstrated. The products of this work were found to exhibit electrical resistivities and dielectric breakdown strengths that PEEK at temperatures above 250C. In addition, sub-scale motor windings were fabricated and tested to validate the performance of this technology

  6. An Internal Coaxial Cable Electrical Connector For Use In Downhole Tools

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Dahlgren, Scott; Fox, Joe; Sneddon, Cameron; Briscoe, Michael

    2005-11-29

    A coaxial cable electrical connector more specifically an internal coaxial cable connector placed within a coaxial cable and its constituent components. A coaxial cable connector is in electrical communcation with an inductive transformer and a coaxial cable. The connector is in electrical communication with the outer housing of the inductive transfonner. A generally coaxial center conductor, a portion of which could be the coil in the inductive transformer, passes through the connector, is electrically insulated from the connector, and is in electrical communication with the conductive care of the coaxial cable. A plurality of bulbous pliant tabs on the coaxial cable connector mechanically engage the inside diameter of the coaxial cable thus grounding the transformer to the coaxial cable. The coaxial cable and inductive transformer are disposed within downhole tools to transmit electrical signals between downhole tools within a drill string.

  7. Tracking CO2 Geosequestration Using Downhole Gravity Gradiometry, Otway Basin, Victoria, Australia.

    NASA Astrophysics Data System (ADS)

    Matthews, S.; O'Neill, C.

    2015-12-01

    Carbon dioxide sequestration is a vital technique for the mitigation of greenhouse gas emissions and anthropogenic global warming. The viability of CO2 geosequestration, and the ability to prevent any leakage or migration depends on the capacity to monitor, and model, the CO2 reservoir. Downhole gravity gradiometry offers an additional capability to CO2 monitoring, and here we demonstrate the downhole gradient effect of CO2 injection at the Otway Basin, Victoria, by the CO2CRC corporation. Data from reservoir modelling has been simulated to calculate gravity gradients to gain an understanding of the behaviour of CO2 once injected into geological storage. Monte Carlo simulations were utilised to determine the uncertainties inherent in the deep subsurface. Presently; models have been created to demonstrate the response caused by the injection of CO2, and we present a statistical analysis to constrain the uncertainties posed by the results.

  8. Biased insert for installing data transmission components in downhole drilling pipe

    DOEpatents

    Hall, David R.; Briscoe, Michael A.; Garner, Kory K.; Wilde, Tyson J.

    2007-04-10

    An apparatus for installing data transmission hardware in downhole tools includes an insert insertable into the box end or pin end of drill tool, such as a section of drill pipe. The insert typically includes a mount portion and a slide portion. A data transmission element is mounted in the slide portion of the insert. A biasing element is installed between the mount portion and the slide portion and is configured to create a bias between the slide portion and the mount portion. This biasing element is configured to compensate for varying tolerances encountered in different types of downhole tools. In selected embodiments, the biasing element is an elastomeric material, a spring, compressed gas, or a combination thereof.

  9. Linear and radial flow targets for characterizing downhole flow in perforations

    SciTech Connect

    Deo, M. ); Tariq, S.M. ); Halleck, P.M. )

    1989-08-01

    Two types of sandstone targets are commonly used to test flow efficiency of shaped-charge jet perforations: linear targets, in which flow enters only the unperforated end of the cylindrical sample, and radial targets, in which flow enters through the end and sides of the sample. To determine which of these targets best represents downhole conditions, the flow distribution along the length of a perforation has been studied by three-dimensional (3D) finite-element analyses. Linear and radial laboratory targets have been compared with downhole perforations under varying conditions. For ideal perforations, the low-shot-density (LSD) case is adequately represented by the radial target, while the high-shot-density (HSD) case falls between the two targets. With realistic crushed and damaged zones, the HSD closely matches the linear target, and the LSD case falls between the two targets.

  10. Fluid flow monitoring in oilfields using downhole measurements of electrokinetic potential

    NASA Astrophysics Data System (ADS)

    Jackson, M. D.; Saunders, J. H.; Pain, C. C.

    2006-12-01

    Permanently installed downhole sensors are increasingly being deployed to provide `real-time' reservoir data during hydrocarbon production, which helps to reduce uncertainty in the reservoir description and contributes to reservoir management decisions. Where wells are equipped with inflow control valves (so called `intelligent' wells), it is possible to develop a feedback loop between measurement and control to optimize production. We suggest that measurements of electrokinetic potential during production, using permanently installed downhole electrodes, could be used to detect water encroachment towards an intelligent oil well. Downhole electrodes mounted at the production well on the outside of insulated casing, have been successfully applied in subsurface resistivity surveys during oil production. Similar technology could be used to measure electrokinetic potential. Moreover, recent and ongoing work has changed our understanding of electrokinetic coupling under two-phase conditions. We present the results of numerical simulations of fluid movement during hydrocarbon production, using a new formulation which captures both the changing fluid distributions and the resulting electrical potentials. We suggest that encroaching water causes changes in electrokinetic potential at the production well which could be resolved above background electrical noise; indeed, changes in water saturation could be detected several 10's to 100's of metres away from the well. This contrasts with most other downhole monitoring techniques, which sample only the region immediately adjacent to the wellbore. Signal resolution is improved if the water has a relatively low salinity, and the pressure gradient into the well is large. However, significant uncertainties remain concerning the nature of electrokinetic coupling during the flow of oil and water, particularly in mixed and oil-wet reservoirs.

  11. A Monte Carlo approach to constraining uncertainties in modelled downhole gravity gradiometry applications

    NASA Astrophysics Data System (ADS)

    Matthews, Samuel J.; O'Neill, Craig; Lackie, Mark A.

    2017-06-01

    Gravity gradiometry has a long legacy, with airborne/marine applications as well as surface applications receiving renewed recent interest. Recent instrumental advances has led to the emergence of downhole gravity gradiometry applications that have the potential for greater resolving power than borehole gravity alone. This has promise in both the petroleum and geosequestration industries; however, the effect of inherent uncertainties in the ability of downhole gravity gradiometry to resolve a subsurface signal is unknown. Here, we utilise the open source modelling package, Fatiando a Terra, to model both the gravity and gravity gradiometry responses of a subsurface body. We use a Monte Carlo approach to vary the geological structure and reference densities of the model within preset distributions. We then perform 100 000 simulations to constrain the mean response of the buried body as well as uncertainties in these results. We varied our modelled borehole to be either centred on the anomaly, adjacent to the anomaly (in the x-direction), and 2500 m distant to the anomaly (also in the x-direction). We demonstrate that gravity gradiometry is able to resolve a reservoir-scale modelled subsurface density variation up to 2500 m away, and that certain gravity gradient components (Gzz, Gxz, and Gxx) are particularly sensitive to this variation in gravity/gradiometry above the level of uncertainty in the model. The responses provided by downhole gravity gradiometry modelling clearly demonstrate a technique that can be utilised in determining a buried density contrast, which will be of particular use in the emerging industry of CO2 geosequestration. The results also provide a strong benchmark for the development of newly emerging prototype downhole gravity gradiometers.

  12. Downhole steam generator using low-pressure fuel and air supply

    DOEpatents

    Fox, R.L.

    1981-01-07

    For tertiary oil recovery, an apparatus for downhole steam generation is designed in which water is not injected directly onto the flame in the combustor, the combustion process is isolated from the reservoir pressure, the fuel and oxidant are supplied to the combustor at relatively low pressures, and the hot exhaust gases is prevented from entering the earth formation but is used to preheat the fuel and oxidant and water. The combustion process is isolated from the steam generation process. (DLC)

  13. Echo State Networks for data-driven downhole pressure estimation in gas-lift oil wells.

    PubMed

    Antonelo, Eric A; Camponogara, Eduardo; Foss, Bjarne

    2017-01-01

    Process measurements are of vital importance for monitoring and control of industrial plants. When we consider offshore oil production platforms, wells that require gas-lift technology to yield oil production from low pressure oil reservoirs can become unstable under some conditions. This undesirable phenomenon is usually called slugging flow, and can be identified by an oscillatory behavior of the downhole pressure measurement. Given the importance of this measurement and the unreliability of the related sensor, this work aims at designing data-driven soft-sensors for downhole pressure estimation in two contexts: one for speeding up first-principle model simulation of a vertical riser model; and another for estimating the downhole pressure using real-world data from an oil well from Petrobras based only on topside platform measurements. Both tasks are tackled by employing Echo State Networks (ESN) as an efficient technique for training Recurrent Neural Networks. We show that a single ESN is capable of robustly modeling both the slugging flow behavior and a steady state based only on a square wave input signal representing the production choke opening in the vertical riser. Besides, we compare the performance of a standard network to the performance of a multiple timescale hierarchical architecture in the second task and show that the latter architecture performs better in modeling both large irregular transients and more commonly occurring small oscillations.

  14. An Internal Coaxial Cable Electrical Connector For Use In Downhole Tools

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Dahlgren, Scott; Fox, Joe; Sneddon, Cameron; Briscoe, Michael

    2005-09-20

    A seal for a coaxial cable electrical connector more specifically an internal seal for a coaxial cable connector placed within a coaxial cable and its constituent components. A coaxial cable connector is in electrical communcation with an inductive transformer and a coaxial cable. The connector is in electrical communication with the outer housing of the inductive transformer. A generally coaxial center conductor, a portion of which could be the coil in the inductive transformer, passes through the connector, is electrically insulated from the connector, and is in electrical communication with the conductive core of the coaxial cable. The electrically insulating material also doubles as a seal to safegaurd against penetration of fluid, thus protecting against shorting out of the electrical connection. The seal is a multi-component seal, which is pre-compressed to a desired pressure rating. The coaxial cable and inductive transformer are disposed within downhole tools to transmit electrical signals between downhole tools within a drill string. The internal coaxial cable connector and its attendant seal can be used in a plurality of downhole tools, such as sections of pipe in a drill string, drill collars, heavy weight drill pipe, and jars.

  15. Back azimuth constrained double-difference seismic location and tomography for downhole microseismic monitoring

    NASA Astrophysics Data System (ADS)

    Chen, Yukuan; Zhang, Haijiang; Miao, Yuanyuan; Zhang, Yinsheng; Liu, Qiang

    2017-03-01

    We have developed a new seismic tomography method, back azimuth constrained double-difference (DD) seismic tomography, which is suitable for downhole microseismic monitoring of hydraulic fracturing. The new method simultaneously locates microseismic events and determines three-dimensional (3D) Vp and Vs models for the fracturing zone using differential arrival times from pairs of events and event back azimuths in addition to absolute arrival times. Compared to the existing DD location and tomography method, our method incorporates back azimuth information to better constrain microseismic event locations in the case of poor spatial station coverage such as the linear downhole seismic array generally used for microseismic monitoring. By incorporating the relative arrival time and back azimuth information of events, the extended DD method can provide better relative event locations, and thus can better characterize the fracture distribution. In addition to microseismic locations, seismic velocity anomalies determined around the fracturing zone may also provide valuable information for fracture development. Due to the existence of fractures and fluids, the seismic velocity is expected to be lower in the fractured zone compared to the surrounding regions. Therefore the area of low seismic velocity anomaly may be used as a proxy for the stimulated reservoir volume. We have applied the new method to a downhole microseismic dataset from shale gas hydraulic fracturing. The microseismic events are more accurately relocated than the conventional grid search location method, and they are generally associated with low velocity anomalies.

  16. Downhole Transformation of the Hydraulic Fracturing Fluid Biocide Glutaraldehyde: Implications for Flowback and Produced Water Quality.

    PubMed

    Kahrilas, Genevieve A; Blotevogel, Jens; Corrin, Edward R; Borch, Thomas

    2016-10-18

    Hydraulic fracturing fluid (HFF) additives are used to enhance oil and gas extraction from unconventional shale formations. Several kilometers downhole, these organic chemicals are exposed to temperatures up to 200 °C, pressures above 10 MPa, high salinities, and a pH range from 5-8. Despite this, very little is known about the fate of HFF additives under these extreme conditions. Here, stainless steel reactors are used to simulate the downhole chemistry of the commonly used HFF biocide glutaraldehyde (GA). The results show that GA rapidly (t1/2 < 1 h) autopolymerizes, forming water-soluble dimers and trimers, and eventually precipitates out at high temperatures (∼140 °C) and/or alkaline pH. Interestingly, salinity was found to significantly inhibit GA transformation. Pressure and shale did not affect GA transformation and/or removal from the bulk fluid. On the basis of experimental pseudo-second-order rate constants, a kinetic model for GA downhole half-life predictions for any combination of these conditions within the limits tested was developed. These findings illustrate that the biocidal GA monomer has limited time to control microbial activity in hot and/or alkaline shales, and may return along with its aqueous transformation products to the surface via flowback and produced water in cooler, more acidic, and saline shales.

  17. Multiwavelength observations of giant radio galaxy 3C 35 and 3C 284

    NASA Astrophysics Data System (ADS)

    Pal, Sabyasachi; Chakrabarti, Sandip Kumar; Patra, Dusmanta; Konar, Chiranjib

    2016-07-01

    We report multi wavelength observations of large radio galaxy 3C35 and 3C284. The low frequency observations were done with the Giant Metrewave Radio Telescope (GMRT) starting from 150 MHz. The high frequency observations were done with Jansky Very Large Array (JVLA). Our main motivation for these observations is to estimate the spectral ages of these galaxies and to examine any proof of extended emission at low radio frequencies due to an earlier cycle of activity. The spectral age is measured by fitting the spectra with different spectral ageing models e.g. Kardashev-Pacholczyk (KP), Jaffe-Perola (JP) and Continuous Injection (CI).

  18. THE SUZAKU VIEW OF 3C 382

    SciTech Connect

    Sambruna, R. M.; Gliozzi, M.; Tombesi, F.; Braito, V.; Ballo, L.; Reynolds, C. S.

    2011-06-20

    We present a long (116 ks) Suzaku observation of the broad-line radio galaxy (BLRG) 3C 382 acquired in 2007 April. A Swift BAT spectrum in 15-200 keV from the 58 month survey is also analyzed, together with an archival XMM-Newton EPIC exposure of 20 ks obtained one year after Suzaku. Our main result is the finding with Suzaku of a broad Fe K line with a relativistic profile consistent with emission from an accretion disk at tens of gravitational radii from the central black hole. The XIS data indicate emission from highly ionized iron and allow us to set tight, albeit model-dependent, constraints on the inner and outer radii of the disk reflecting region, r{sub in} {approx_equal} 10 r{sub g} and r{sub out} {approx_equal} 20 r{sub g} , respectively, and on the disk inclination, i {approx_equal} 30{sup 0}. Two ionized reflection components are possibly observed, with similar contributions of {approx}10% to the total continuum-a highly ionized one, with log{xi} {approx_equal} 3 erg s{sup -1} cm, which successfully models the relativistic line, and a mildly ionized one, with log{xi} {approx_equal} 1.5 erg s{sup -1} cm, which models the narrow Fe K{alpha} and high energy hump. When both these components are included, there is no further requirement for an additional blackbody soft excess below 2 keV. The Suzaku data confirm the presence of a warm absorber previously known from grating studies. After accounting for all the spectral features, the intrinsic photon index of the X-ray continuum is {Gamma}{sub x} {approx_equal} 1.8 with a cutoff energy at {approx}200 keV, consistent with Comptonization models and excluding jet-related emission up to these energies. Comparison of the X-ray properties of 3C 382 and other BLRGs to Seyferts recently observed with Suzaku and BAT confirms the idea that the distinction between radio-loud and radio-quiet active galactic nucleus at X-rays is blurred. The two classes form a continuum distribution in terms of X-ray photon index

  19. Cell-Detection Technique for Automated Patch Clamping

    NASA Technical Reports Server (NTRS)

    McDowell, Mark; Gray, Elizabeth

    2008-01-01

    A unique and customizable machinevision and image-data-processing technique has been developed for use in automated identification of cells that are optimal for patch clamping. [Patch clamping (in which patch electrodes are pressed against cell membranes) is an electrophysiological technique widely applied for the study of ion channels, and of membrane proteins that regulate the flow of ions across the membranes. Patch clamping is used in many biological research fields such as neurobiology, pharmacology, and molecular biology.] While there exist several hardware techniques for automated patch clamping of cells, very few of those techniques incorporate machine vision for locating cells that are ideal subjects for patch clamping. In contrast, the present technique is embodied in a machine-vision algorithm that, in practical application, enables the user to identify good and bad cells for patch clamping in an image captured by a charge-coupled-device (CCD) camera attached to a microscope, within a processing time of one second. Hence, the present technique can save time, thereby increasing efficiency and reducing cost. The present technique involves the utilization of cell-feature metrics to accurately make decisions on the degree to which individual cells are "good" or "bad" candidates for patch clamping. These metrics include position coordinates (x,y) in the image plane, major-axis length, minor-axis length, area, elongation, roundness, smoothness, angle of orientation, and degree of inclusion in the field of view. The present technique does not require any special hardware beyond commercially available, off-the-shelf patch-clamping hardware: A standard patchclamping microscope system with an attached CCD camera, a personal computer with an imagedata- processing board, and some experience in utilizing imagedata- processing software are all that are needed. A cell image is first captured by the microscope CCD camera and image-data-processing board, then the image

  20. OSSE observations of 3C 273

    NASA Technical Reports Server (NTRS)

    Johnson, W. N.; Dermer, C. D.; Kinzer, R. L.; Kurfess, J. D.; Strickman, M. S.; Mcnaron-Brown, K.; Jourdain, E.; Jung, G. V.; Grabelsky, D. A.; Purcell, W. R.

    1995-01-01

    We report results of multiple observations of the quasar 3C 273 with the Oriented Scintillation Spectrometer Experiment (OSSE) instrument on the Compton Gamma Ray Observatory. These observations span the period from 1991 June through 1993 January and represent the most sensitive observations to date in low-energy gamma rays. The source was detected at historically weak 100 keV fluxes compared with previous measurements. Variability by factors of approximately 3 on timescales of approximately equal 2 months was observed in the energy band 50-150 keV. The data are well described by a single power law with a proton number index Gamma = 1.7 +/- 0.1. No significant change of Gamma was observed during changes in intensity. Thermal models do not provide acceptable fits to the data. When the OSSE data are combined with contemporaneous measurements by COMPTEL and EGRET, the spectrum is seen to break at an energy of 1.0(+0.9, -0.4) MeV to a softer power law with Delta Gamma = 0.7(+0.06, -0.11), forming a power law with Gamma = 2.4 between approximately 1 MeV and several GeV.

  1. The resolved outflow from 3C 48

    SciTech Connect

    Shih, Hsin-Yi; Stockton, Alan E-mail: stockton@ifa.hawaii.edu

    2014-10-20

    We investigate the properties of the high-velocity outflow driven by the young radio jet of 3C 48, a compact-steep-spectrum source. We use the Space Telescope Imaging Spectrograph on board the Hubble Space Telecope to obtain (1) low-resolution UV and optical spectra and (2) multi-slit medium-resolution spectra of the ionized outflow. With supporting data from ground-based spectrographs, we are able to accurately measure the ratios of diagnostic emission lines such as [O III] λ5007, [O III] λ3727, [N II] λ6548, Hα, Hβ, [Ne V] λ3425, and [Ne III] λ3869. We fit the observed emission-line ratios using a range of ionization models, powered by active galactic nucleus (AGN) radiation and shocks, produced by the MAPPINGS code. We have determined that AGN radiation is likely the dominant ionization source. The outflow's density is estimated to be in the range n = 10{sup 3}-10{sup 4} cm{sup –3}, the mass is ∼6 × 10{sup 6} M {sub ☉}, and the metallicity is likely equal to or higher than solar. Compared with the typical outflows associated with more evolved radio jets, this young outflow is denser, less massive, and more metal rich. Multi-slit observations allow us to construct a two-dimensional velocity map of the outflow that shows a wide range of velocities with distinct velocity components, suggesting a wide-angle clumpy outflow.

  2. 3C 236: Radio Source, Interrupted?

    NASA Astrophysics Data System (ADS)

    O'Dea, Christopher P.; Koekemoer, Anton M.; Baum, Stefi A.; Sparks, William B.; Martel, André R.; Allen, Mark G.; Macchetto, Ferdinando D.; Miley, George K.

    2001-04-01

    We present new Hubble Space Telescope Space Telescope Imaging Spectrograph MAMA near-UV images and archival Wide Field Planetary Camera 2 (WFPC2) V- and R-band images that reveal the presence of four star-forming regions in an arc along the edge of the dust lane in the giant (4 Mpc) radio galaxy 3C 236. Two of the star-forming regions are relatively young, with ages of order ~107 yr, while the other two are older, with ages of order ~108-109 yr, which is comparable to the estimated age of the giant radio source. Based on dynamical and spectral aging arguments, we suggest that the fuel supply to the active galactic nucleus (AGN) was interrupted for ~107 yr and has now been restored, resulting in the formation of the inner 2 kpc-scale radio source. This timescale is similar to that of the age of the youngest of the star-forming regions. We suggest that the transport of gas in the disk is nonsteady and that this produces the multiple episodes of star formation in the disk, as well as the multiple epochs of radio source activity. If the inner radio source and the youngest star-forming region are related by the same event of gas transport, the gas must be transported from the hundreds of parsec scale to the subparsec scale on a timescale of ~107 yr, which is similar to the dynamical timescale of the gas on the hundreds of parsec scale.

  3. 3C236: Radio Source, Interrupted?

    NASA Astrophysics Data System (ADS)

    O'Dea, C. P.; Koekemoer, A. M.; Baum, S. A.; Sparks, W. B.

    We present highlights of the results of new HST STIS/MAMA near-UV images and archival WFPC2 V- and R-band images which reveal the presence of four apparently star forming regions in an arc along the edge of the dust lane in the giant (4 Mpc) radio galaxy 3C236. Two of the star forming regions are relatively young with ages of order ~107 yr, while the other two are older with ages of order ~108 -- 109 yr, which is comparable to the estimated age of the giant radio source. Based on dynamical and spectral aging arguments, we suggest that the fuel supply to the AGN was interrupted for ~107 yr and has now been restored, resulting in the formation of the inner 2 kpc scale radio source. This time scale is similar to that of the age of the youngest of the star forming regions. We suggest that the transport of gas in the disk is non-steady and that this produces both the multiple episodes of star formation in the disk as well as the multiple epochs of radio source activity. If the inner radio source and the youngest star forming region are related by the same event of gas transport, the gas must be transported from the hundreds of pc scale to the sub-parsec scale on a time scale of ~107 yr, which is similar to the dynamical timescale of the gas on the hundreds of pc scales.

  4. Multifrequency Monitoring of 3C 120, 3C 279, and PKS 1510--089

    NASA Technical Reports Server (NTRS)

    Jorstad, S. G.; Marscher, A. P.; Aller, M. F.; Balonek, T. J.; Gomez, J.-L.; McHardy, I. M.; Terasranta, H.; Raiteri, C.; Tosti, G.

    2001-01-01

    We analyze contemporaneous X-ray, optical, and radio light curves of 3C 120, ABC 279, and PKS 1510-089 on timescales from a few to hundreds of days over a 3-5 year period. The results show the diverse connections between variability properties at different frequencies for different blazers.

  5. HST And VLA Polarimetry Of 3C 264 And 3C 66B

    NASA Astrophysics Data System (ADS)

    Padgett, C. Alexander; Perlman, E. S.; Georganopoulos, M.; O'Dea, C. P.; Baum, S. A.; Sparks, W. B.; Biretta, J. A.

    2006-09-01

    We present new VLA A- and B-array radio polarimetry at 22.5 GHz, and images at 8.4GHz of 3C 264, a low luminosity FR I in Abell 1367. We also present high resolution VLA A-array polarimetry of the jet of 3C 66B, both at 22.5 GHz and 43 GHz. This is the latest addition to an ongoing study of these objects, which includes optical polarimetry in several bands and multiband imaging with HST, and X-ray observations with Chandra. We find further evidence for the hypothesis that 3C 264 falls into the category of low luminosity BL Lac objects (Rector, Stocke & Perlman, 1999) in significant variability of the polarization position angle in the core of this object in only 4 years (Lara et al, 2003). This variability, together with our measured value of its optical spectral index of alpha = 0.77, and a previously derived viewing angle of < 50 degrees (Baum et al, 1997; Lara et al, 2003), puts a fairly strong constraint on the classification of 3C 264 as a low luminosity BL Lac. We also present matched resolution HST and VLA data for both of these objects, allowing for direct morphological comparisons to be made, as well as full resolution radio to optical spectral index maps.

  6. Low-frequency study of two giant radio galaxies: 3C 35 and 3C 223

    NASA Astrophysics Data System (ADS)

    Orrù, E.; Murgia, M.; Feretti, L.; Govoni, F.; Giovannini, G.; Lane, W.; Kassim, N.; Paladino, R.

    2010-06-01

    Aims: Radio galaxies with a projected linear size ⪆1 Mpc are classified as giant radio sources. According to the current interpretation these are old sources which have evolved in a low-density ambient medium. Because radiative losses are negligible at low frequency, extending spectral aging studies in this frequency range will allow us to determine the zero-age electron spectrum injected and then to improve the estimate of the synchrotron age of the source. Methods: We present Very Large Array images at 74 MHz and 327 MHz of two giant radio sources: 3C 35 and 3C 223. We performed a spectral study using 74, 327, 608 and 1400 GHz images. The spectral shape is estimated in different positions along the source. Results: The radio spectrum follows a power-law in the hotspots, while in the inner region of the lobe the shape of the spectrum shows a curvature at high frequencies. This steepening agrees with synchrotron aging of the emitting relativistic electrons. In order to estimate the synchrotron age of the sources, the spectra were fitted with a synchrotron model of emission. They show that 3C 35 is an old source of 143 ± 20 Myr, while 3C 223 is a younger source of 72 ± 4 Myr.

  7. Trends in Aortic Clamp Use During Coronary Artery Bypass Surgery: The Effect of Aortic Clamping Strategies on Neurologic Outcomes

    PubMed Central

    Daniel, William T.; Kilgo, Patrick; Puskas, John D.; Thourani, Vinod H.; Lattouf, Omar M.; Guyton, Robert A.; Halkos, Michael E.

    2013-01-01

    Objective The purpose of this study was to determine the impact of different clamping strategies during CABG on the incidence of postoperative stroke. Methods In this case-control study, all patients at Emory hospitals from 2002–2009 with postoperative stroke after isolated CABG (N=141) were matched 1:4 to a contemporaneous cohort of patients without postoperative stroke (N=565). Patients were matched according to the Society of Thoracic Surgeons (STS) Predicted Risk of Postoperative Stroke (PROPS), which is based on 26 variables. On- (ONCAB) and off-pump (OPCAB) patients were matched separately. Multiple logistic regression analysis with adjusted odds ratios (OR) was performed to identify operative variables associated with postoperative stroke. Results Among the ONCAB cohort, the single cross-clamp technique was associated with a decreased risk of stroke compared to the double clamp (cross clamp + partial clamp) technique (OR=0.385, p=0.044). Within the OPCAB cohort, there was no significant difference in stroke according to clamp use. Epiaortic ultrasound of the ascending aorta increased from 45.3% in 2002 to 89.4% in 2009. From 2002–2009, clamp use decreased from 97.7% of cases to 72.7%. Conclusions During ONCAB, the use of a single cross-clamp compared to the double clamp technique decreases the risk of postoperative stroke. The use of any aortic clamp has decreased and epiaortic ultrasound use has increased from 2002–2009, indicating a change in operative technique and surgeon awareness of the potential complications associated with manipulation of the aorta. PMID:23477689

  8. Single electrode dynamic clamp with StdpC.

    PubMed

    Samu, David; Marra, Vincenzo; Kemenes, Ildiko; Crossley, Michael; Kemenes, György; Staras, Kevin; Nowotny, Thomas

    2012-10-15

    Dynamic clamp is a powerful approach for electrophysiological investigations allowing researchers to introduce artificial electrical components into target neurons to simulate ionic conductances, chemical or electrotonic inputs or connections to other cells. Due to the rapidly changing and potentially large current injections during dynamic clamp, problematic voltage artifacts appear on the electrode used to inject dynamic clamp currents into a target neuron. Dynamic clamp experiments, therefore, typically use two separate electrodes in the same cell, one for recording membrane potential and one for injecting currents. The requirement for two independent electrodes has been a limiting factor for the use of dynamic clamp in applications where dual recordings of this kind are difficult or impossible to achieve. The recent development of an active electrode compensation (AEC) method has overcome some of these prior limitations, permitting artifact-free dynamic clamp experimentation with a single electrode. Here we describe an AEC method for the free dynamic clamp software StdpC. The AEC component of StdpC is the first such system implemented for the use of non-expert users and comes with a set of semi-automated configuration and calibration procedures that facilitate its use. We briefly introduce the AEC method and its implementation in StdpC and then validate it with an electronic model cell and in two different biological preparations.

  9. Single electrode dynamic clamp with StdpC

    PubMed Central

    Samu, David; Marra, Vincenzo; Kemenes, Ildiko; Crossley, Michael; Kemenes, György; Staras, Kevin; Nowotny, Thomas

    2012-01-01

    Dynamic clamp is a powerful approach for electrophysiological investigations allowing researchers to introduce artificial electrical components into target neurons to simulate ionic conductances, chemical or electrotonic inputs or connections to other cells. Due to the rapidly changing and potentially large current injections during dynamic clamp, problematic voltage artifacts appear on the electrode used to inject dynamic clamp currents into a target neuron. Dynamic clamp experiments, therefore, typically use two separate electrodes in the same cell, one for recording membrane potential and one for injecting currents. The requirement for two independent electrodes has been a limiting factor for the use of dynamic clamp in applications where dual recordings of this kind are difficult or impossible to achieve. The recent development of an active electrode compensation (AEC) method has overcome some of these prior limitations, permitting artifact-free dynamic clamp experimentation with a single electrode. Here we describe an AEC method for the free dynamic clamp software StdpC. The AEC component of StdpC is the first such system implemented for the use of non-expert users and comes with a set of semi-automated configuration and calibration procedures that facilitate its use. We briefly introduce the AEC method and its implementation in StdpC and then validate it with an electronic model cell and in two different biological preparations. PMID:22898473

  10. Effect of delayed umbilical cord clamping on blood gas analysis.

    PubMed

    Valero, Javier; Desantes, Domingo; Perales-Puchalt, Alfredo; Rubio, Juan; Diago Almela, Vicente J; Perales, Alfredo

    2012-05-01

    To ascertain if there are differences in umbilical cord blood gas analysis between immediate and delayed cord clamping. In a prospective observational study on 60 vaginally delivered healthy term newborns, we sampled umbilical cord blood immediately after delivery and at the time umbilical cord pulsation spontaneously ceased. There were significant decreases in pH, oxygen saturation (sO(2)), glycemia, oxygen content (ctO(2)), bicarbonate (HCO(3)(-)) and base excess (BE). Lactate and [Formula: see text] increased. Delayed cord clamping pH correlated with immediate cord clamping pH, [Formula: see text] , ctHb, sO(2) and time (r(2)=0.77, p<0.000). Delayed cord clamping lactate was associated with immediate cord clamping lactate and time (r(2)=0.83, p<0.000). Delayed BE was associated with previous pH, lactate, glycemia, ctHb and time (r(2)=0.83, p<0.000). Delayed cord clamping alters acid-base parameters and lactate values compared to immediate cord clamping. Those variations depend mainly on time, prior pH and lactate. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  11. Committee Opinion No. 684: Delayed Umbilical Cord Clamping After Birth.

    PubMed

    2017-01-01

    Delayed umbilical cord clamping appears to be beneficial for term and preterm infants. In term infants, delayed umbilical cord clamping increases hemoglobin levels at birth and improves iron stores in the first several months of life, which may have a favorable effect on developmental outcomes. There is a small increase in jaundice that requires phototherapy in this group of infants. Consequently, health care providers adopting delayed umbilical cord clamping in term infants should ensure that mechanisms are in place to monitor for and treat neonatal jaundice. In preterm infants, delayed umbilical cord clamping is associated with significant neonatal benefits, including improved transitional circulation, better establishment of red blood cell volume, decreased need for blood transfusion, and lower incidence of necrotizing enterocolitis and intraventricular hemorrhage. Delayed umbilical cord clamping was not associated with an increased risk of postpartum hemorrhage or increased blood loss at delivery, nor was it associated with a difference in postpartum hemoglobin levels or the need for blood transfusion. Given the benefits to most newborns and concordant with other professional organizations, the American College of Obstetricians and Gynecologists now recommends a delay in umbilical cord clamping in vigorous term and preterm infants for at least 30-60 seconds after birth. The ability to provide delayed umbilical cord clamping may vary among institutions and settings; decisions in those circumstances are best made by the team caring for the mother-infant dyad.

  12. Avoiding aortic clamping during CABG reduces postoperative stroke

    PubMed Central

    Moss, Emmanuel; Puskas, John D; Thourani, Vinod H; Kilgo, Patrick; Chen, Edward P; Leshnower, Bradley G; Lattouf, Omar M; Guyton, Robert A.; Glas, Kathryn E; Halkos, Michael E.

    2014-01-01

    Objective The purpose of this study was to determine whether the incidence of postoperative stroke (PS) could be reduced by eliminating aortic clamping during CABG. Methods From 2002–2013, 12,079 patients underwent primary, isolated CABG at a single US academic institution. Aortic manipulation was completely avoided by using in-situ internal mammary arteries for inflow in 1,552 (12.9%) patients (no-touch), a clampless facilitating device (CFD) was used for proximal anastomoses in 1,548 (12.8%) patients, and aortic clamping was used in 8,979 (74.3%) patients. These strategies were assessed in a logistic regression model controlling for relevant variables. Results The overall incidence of PS was 1.4% (n=165), with an unadjusted incidence of 0.6% (n=10) in the no-touch group, 1.2% (n=18) in the CFD group, and 1.5% (n=137) in the clamp group (p<0.01 for no-touch vs clamp). The ratio of observed to expected stroke rate increased as the degree of aortic manipulation increased, from 0.48 in the no-touch group, to 0.61 in the CFD group, and 0.95 in the clamp group. Aortic clamping was independently associated with an increase in PS compared to a no-touch technique (AOR 2.50, p<0.01). When separated by CPB utilization, both the off-pump partial clamp and on-pump cross-clamp techniques increased the risk of PS compared to no-touch (AOR 2.52, p<0.01 and AOR 4.25, p<0.001, respectively). Conclusion A no-aortic touch technique has the lowest risk for postoperative stroke for patients undergoing CABG. Clamping the aorta during CABG increases the risk of PS, regardless of the severity of aortic disease. PMID:25293356

  13. The Accelerating Jet of 3C 279

    NASA Astrophysics Data System (ADS)

    Bloom, S. D.; Fromm, C. M.; Ros, E.

    2013-01-01

    Analysis of the proper motions of the subparsec scale jet of the quasar 3C 279 at 15 GHz with the Very Long Baseline Array shows significant accelerations in four of nine superluminal features. Analysis of these motions is combined with the analysis of flux density light curves to constrain values of Lorentz factor and viewing angle (and their derivatives) for each component. The data for each of these components are consistent with significant changes to the Lorentz factor, viewing angle, and azimuthal angle, suggesting jet bending with changes in speed. We see that for these observed components Lorentz factors are in the range Γ = 10-41, viewing angles are in the range thetav = 0.°1-5.°0, and intrinsic (source frame) flux density is in the range, F ν, int = 1.5 × 10-9-1.5 × 10-5 Jy. Considering individual components, the Lorentz factors vary from Γ = 11-16 for C1, Γ = 31-41 for C5, Γ = 29-41 for C6, and Γ = 9-12 for C8, indicating that there is no single underlying flow speed to the jet and likely we are seeing pattern speeds from shocks in the jet. The viewing angles vary in time from 0.°6 to 1.°5 in the case of C1 (the least extreme example), from 0.°5 to 5.°0 in the case of C8, and from 0.°1 to 0.°9 for C5 (the last two being the most extreme examples). The intrinsic flux density varies by factors from 1.4 for C8 and 430 for C5. Theoretical analysis of the accelerations also indicates potential jet bending. In addition, for one component, C5, polarization measurements also set limits to the trajectory of the jet.

  14. Reciprocating clamp apparatus for thermoforming plastic containers

    SciTech Connect

    Beck, M.H.; Harry, I.L.; Krishnakumar, S.M.

    1984-03-06

    This relates to the forming of containers and like hollow articles from sheets or webs of thermoplastic material. Two webs or sheets are simultaneously acted upon by way of a forming apparatus which includes a reciprocating clamp first cooperable with one outer platen and then the other in sequence wherein, while a first web or sheet is being formed within a plurality of mold cavities to define a plurality of hollow articles such as containers, the other sheet or web may be stripped from its respective mold set and a new sheet or a new portion of a sheet or web may be advanced into position for molding. The forming apparatus may be constructed in a manner wherein the web portions which are to be formed may be billowed away from the mold cavities as an initial step in the stretching and orientation of the thermoplastic material. The thermoplastic material may be heated to the desired forming temperature using separate sets of rf electrodes so that only those portions of the thermoplastic material which are to be formed need be heated. Two sets of containers of different sizes may be formed from the webs or sheets, and then internested to form double wall containers wherein the walls may be formed of different materials and wherein the outer material may be a barrier material, or wherein the walls of the containers are spaced apart to form an insulated container. This abstract forms no part of the specification of this application and is not to be construed as limiting the claims of the application.

  15. Photosynthesis of C3, C3-C4, and C4 grasses at glacial CO2.

    PubMed

    Pinto, Harshini; Sharwood, Robert E; Tissue, David T; Ghannoum, Oula

    2014-07-01

    Most physiology comparisons of C3 and C4 plants are made under current or elevated concentrations of atmospheric CO2 which do not reflect the low CO2 environment under which C4 photosynthesis has evolved. Accordingly, photosynthetic nitrogen (PNUE) and water (PWUE) use efficiency, and the activity of the photosynthetic carboxylases [Rubisco and phosphoenolpyruvate carboxylase (PEPC)] and decarboxylases [NADP-malic enzyme (NADP-ME) and phosphoenolpyruvate carboxykinase (PEP-CK)] were compared in eight C4 grasses with NAD-ME, PCK, and NADP-ME subtypes, one C3 grass, and one C3-C4 grass grown under ambient (400 μl l(-1)) and glacial (180 μl l(-1)) CO2. Glacial CO2 caused a smaller reduction of photosynthesis and a greater increase of stomatal conductance in C4 relative to C3 and C3-C4 species. Panicum bisulcatum (C3) acclimated to glacial [CO2] by doubling Rubisco activity, while Rubisco was unchanged in Panicum milioides (C3-C4), possibly due to its high leaf N and Rubisco contents. Glacial CO2 up-regulated Rubisco and PEPC activities in concert for several C4 grasses, while NADP-ME and PEP-CK activities were unchanged, reflecting the high control exerted by the carboxylases relative to the decarboxylases on the efficiency of C4 metabolism. Despite having larger stomatal conductance at glacial CO2, C4 species maintained greater PWUE and PNUE relative to C3-C4 and C3 species due to higher photosynthetic rates. Relative to other C4 subtypes, NAD-ME and PEP-CK grasses had the highest PWUE and PNUE, respectively; relative to C3, the C3-C4 grass had higher PWUE and similar PNUE at glacial CO2. Biomass accumulation was reduced by glacial CO2 in the C3 grass relative to the C3-C4 grass, while biomass was less reduced in NAD-ME grasses compared with NADP-ME and PCK grasses. Under glacial CO2, high resource use efficiency offers a key evolutionary advantage for the transition from C3 to C4 photosynthesis in water- and nutrient-limited environments. © The Author 2014

  16. The Resolved Outflow from 3C 48

    NASA Astrophysics Data System (ADS)

    Shih, Hsin-Yi; Stockton, Alan

    2014-10-01

    We investigate the properties of the high-velocity outflow driven by the young radio jet of 3C 48, a compact-steep-spectrum source. We use the Space Telescope Imaging Spectrograph on board the Hubble Space Telecope to obtain (1) low-resolution UV and optical spectra and (2) multi-slit medium-resolution spectra of the ionized outflow. With supporting data from ground-based spectrographs, we are able to accurately measure the ratios of diagnostic emission lines such as [O III] λ5007, [O III] λ3727, [N II] λ6548, Hα, Hβ, [Ne V] λ3425, and [Ne III] λ3869. We fit the observed emission-line ratios using a range of ionization models, powered by active galactic nucleus (AGN) radiation and shocks, produced by the MAPPINGS code. We have determined that AGN radiation is likely the dominant ionization source. The outflow's density is estimated to be in the range n = 103-104 cm-3, the mass is ~6 × 106 M ⊙, and the metallicity is likely equal to or higher than solar. Compared with the typical outflows associated with more evolved radio jets, this young outflow is denser, less massive, and more metal rich. Multi-slit observations allow us to construct a two-dimensional velocity map of the outflow that shows a wide range of velocities with distinct velocity components, suggesting a wide-angle clumpy outflow. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO-11574. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Some of the

  17. THE ACCELERATING JET OF 3C 279

    SciTech Connect

    Bloom, S. D.; Fromm, C. M.; Ros, E.

    2013-01-01

    Analysis of the proper motions of the subparsec scale jet of the quasar 3C 279 at 15 GHz with the Very Long Baseline Array shows significant accelerations in four of nine superluminal features. Analysis of these motions is combined with the analysis of flux density light curves to constrain values of Lorentz factor and viewing angle (and their derivatives) for each component. The data for each of these components are consistent with significant changes to the Lorentz factor, viewing angle, and azimuthal angle, suggesting jet bending with changes in speed. We see that for these observed components Lorentz factors are in the range {Gamma} = 10-41, viewing angles are in the range thetav = 0. Degree-Sign 1-5. Degree-Sign 0, and intrinsic (source frame) flux density is in the range, F{sub {nu},int} 1.5 Multiplication-Sign 10{sup -9}-1.5 Multiplication-Sign 10{sup -5} Jy. Considering individual components, the Lorentz factors vary from {Gamma} = 11-16 for C1, {Gamma} = 31-41 for C5, {Gamma} = 29-41 for C6, and {Gamma} = 9-12 for C8, indicating that there is no single underlying flow speed to the jet and likely we are seeing pattern speeds from shocks in the jet. The viewing angles vary in time from 0. Degree-Sign 6 to 1. Degree-Sign 5 in the case of C1 (the least extreme example), from 0. Degree-Sign 5 to 5. Degree-Sign 0 in the case of C8, and from 0. Degree-Sign 1 to 0. Degree-Sign 9 for C5 (the last two being the most extreme examples). The intrinsic flux density varies by factors from 1.4 for C8 and 430 for C5. Theoretical analysis of the accelerations also indicates potential jet bending. In addition, for one component, C5, polarization measurements also set limits to the trajectory of the jet.

  18. Jet precession and its observational evidence: The cases of 3C 345 and 3C 120

    NASA Astrophysics Data System (ADS)

    Caproni, Anderson; Abraham, Zulema

    2004-11-01

    Several radio-loud objects exhibit a complex structure when observed at radio wavelengths: a stationary core, which is thought to harbour the central engine that powers the AGN phenomena, and a relativistic jet, formed by several superluminal components. In some cases, jet components are ejected with different apparent proper motions and directions on the plane of the sky. Moreover, these sources can also show signatures of long-term periodic variability in their historical optical light curve. In this work, we selected the objects 3C 120 and 3C 345, which exhibit both characteristics mentioned above, and interpret them in the framework of jet inlet precession. A brief discussion about what kind of mechanism could be responsible for jet precession is also presented.

  19. The Application of Mechanical Clamps to Portsmouth Connectors.

    DTIC Science & Technology

    1981-11-23

    Resistance Readings ..... .............. .64 TABLE 12 - ALT SUMM!ARY - POLYURETHANE CONNECTORS Resis- ance Readings ..... .............. .65 v7 ft...34 FIGURE 17 Pressure Tank Pressure Fittings . ........ . 37 vi I THE APPLICATION OF MECHANICAL CLAMPS TO PORTSMOUTH CONNECTORS BACKGROUN )D This

  20. Studying mechanosensitive ion channels with an automated patch clamp.

    PubMed

    Barthmes, Maria; Jose, Mac Donald F; Birkner, Jan Peter; Brüggemann, Andrea; Wahl-Schott, Christian; Koçer, Armağan

    2014-03-01

    Patch clamp electrophysiology is the main technique to study mechanosensitive ion channels (MSCs), however, conventional patch clamping is laborious and success and output depends on the skills of the operator. Even though automated patch systems solve these problems for other ion channels, they could not be applied to MSCs. Here, we report on activation and single channel analysis of a bacterial mechanosensitive ion channel using an automated patch clamp system. With the automated system, we could patch not only giant unilamellar liposomes but also giant Escherichia coli (E. coli) spheroplasts. The tension sensitivity and channel kinetics data obtained in the automated system were in good agreement with that obtained from the conventional patch clamp. The findings will pave the way to high throughput fundamental and drug screening studies on mechanosensitive ion channels.

  1. A clamp-like biohybrid catalyst for DNA oxidation

    NASA Astrophysics Data System (ADS)

    van Dongen, Stijn F. M.; Clerx, Joost; Nørgaard, Kasper; Bloemberg, Tom G.; Cornelissen, Jeroen J. L. M.; Trakselis, Michael A.; Nelson, Scott W.; Benkovic, Stephen J.; Rowan, Alan E.; Nolte, Roeland J. M.

    2013-11-01

    In processive catalysis, a catalyst binds to a substrate and remains bound as it performs several consecutive reactions, as exemplified by DNA polymerases. Processivity is essential in nature and is often mediated by a clamp-like structure that physically tethers the catalyst to its (polymeric) template. In the case of the bacteriophage T4 replisome, a dedicated clamp protein acts as a processivity mediator by encircling DNA and subsequently recruiting its polymerase. Here we use this DNA-binding protein to construct a biohybrid catalyst. Conjugation of the clamp protein to a chemical catalyst with sequence-specific oxidation behaviour formed a catalytic clamp that can be loaded onto a DNA plasmid. The catalytic activity of the biohybrid catalyst was visualized using a procedure based on an atomic force microscopy method that detects and spatially locates oxidized sites in DNA. Varying the experimental conditions enabled switching between processive and distributive catalysis and influencing the sliding direction of this rotaxane-like catalyst.

  2. Spatial dynamics, thermalization, and gain clamping in a photon condensate

    NASA Astrophysics Data System (ADS)

    Keeling, Jonathan; Kirton, Peter

    2016-01-01

    We study theoretically the effects of pump-spot size and location on photon condensates. By exploring the inhomogeneous molecular excitation fraction, we make clear the relation between spatial equilibration, gain clamping, and thermalization in a photon condensate. This provides a simple understanding of several recent experimental results. We find that as thermalization breaks down, gain clamping is imperfect, leading to "transverse spatial hole burning" and multimode condensation. This opens the possibility of engineering the gain profile to control the condensate structure.

  3. Lotus birth, a holistic approach on physiological cord clamping.

    PubMed

    Zinsser, Laura A

    2017-09-04

    The positive effects of delayed cord clamping (DCC) has been extensively researched. DCC means: waiting at least one minute after birth before clamping and cutting the cord or till the pulsation has stopped. With physiological clamping and cutting (PCC) the clamping and cutting can happen at the earliest after the pulsation has stopped. With a Lotus birth, no clamping and cutting of the cord is done. A woman called Clair Lotus Day imitated the holistic approach of PCC from an anthropoid ape in 1974. The chimpanzee did not separate the placenta from the newborn. The aim of this case report is to discuss and learn a different approach in the third stage of labour. Three cases of Lotus birth by human beings were observed. All three women gave birth in an out-of-hospital setting and had ambulant postnatal care. The placenta was washed, salted and herbs were put on 2-3h post partum. The placenta was wrapped in something that absorbs the moisture. The salting was repeated with a degreasing frequency depending on moistness of the placenta. On life day six all three Lotus babies experiences a natural separation of the cord. All three Lotus birth cases were unproblematic, no special incidence occurred. One should differentiate between early cord clamping (ECC), delayed cord clamping (DCC) and physiological cord clamping (PCC). Lotus birth might lead to an optimisation of the bonding and attachment. Research is needed in the areas of both PCC and Lotus birth. Copyright © 2017 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

  4. Effects of Injected Fluids on Pre-existing Faults observed from Surface and Downhole Seismic Arrays

    NASA Astrophysics Data System (ADS)

    Tang, Y.; Niu, F.; Chen, H.; Zuo, Q.

    2016-12-01

    Hydraulic fracturing is the key stimulation technology to improve unconventional hydrocarbon recovery. It involves pumping high-pressure fluid into reservoir rocks to force the opening of cracks, which could allow oil and gas to flow freely. The effects of injected fluids and associated stress changes on pre-existing faults must be monitored carefully to avoid undesirable ruptures. We deployed a small-scale seismic array consisting of 22 broadband seismographs at the surface and 20 downhole seismographs to study the dynamic processes involved in hydraulic fracturing. The simultaneous monitoring of surface and downhole seismic array could increase the detectability of microseismic events and enhance location accuracy. The downhole seismic array detected a total of 7270 microseismic events and 961 events were recorded by surface seismic array with high signal-to-noise ratios (SNRs). We found that induced seismicity occurred during and after the fluid injection with large spatial variations. This is also true to the inverted focal mechanisms. We noticed that several clusters of events are located >1 km away from the perforation shots such that their occurrence seems to have no direct involvement of the inject fluid. More likely they seem to be triggered slips on pre-existing faults. The pre-existing faults were reactivated by the injection of the early stages, and the triggered seismicity continued during the later operation regardless whether there is inflow of the fluid injected by the later stages. Overall, the "dry" triggered remote seismicity seems to have a higher average magnitude and a lower b-value in comparison with the "wet" inducted seismicity around the perforation shots.

  5. ENHANCED OIL RECOVERY WITH DOWNHOLE VIBRATION STIMULATION IN OSAGE COUNTY OKLAHOMA

    SciTech Connect

    Robert Westermark; J. Ford Brett

    2003-11-01

    This Final Report covers the entire project from July 13, 2000 to June 30, 2003. The report summarizes the details of the work done on the project entitled ''Enhanced Oil Recovery with Downhole Vibration Stimulation in Osage County Oklahoma'' under DOE Contract Number DE-FG26-00BC15191. The project was divided into nine separate tasks. This report is written in an effort to document the lessons learned during the completion of each task. Therefore each task will be discussed as the work evolved for that task throughout the duration of the project. Most of the tasks are being worked on simultaneously, but certain tasks were dependent on earlier tasks being completed. During the three years of project activities, twelve quarterly technical reports were submitted for the project. Many individual topic and task specific reports were included as appendices in the quarterly reports. Ten of these reports have been included as appendices to this final report. Two technical papers, which were written and accepted by the Society of Petroleum Engineers, have also been included as appendices. The three primary goals of the project were to build a downhole vibration tool (DHVT) to be installed in seven inch casing, conduct a field test of vibration stimulation in a mature waterflooded field and evaluate the effects of the vibration on both the produced fluid characteristics and injection well performance. The field test results are as follows: In Phase I of the field test the DHVT performed exceeding well, generating strong clean signals on command and as designed. During this phase Lawrence Berkeley National Laboratory had installed downhole geophones and hydrophones to monitor the signal generated by the downhole vibrator. The signals recorded were strong and clear. Phase II was planned to be ninety-day reservoir stimulation field test. This portion of the field tests was abruptly ended after one week of operations, when the DHVT became stuck in the well during a routine

  6. Program for the improvement of downhole drilling motor bearings and seals. Phase V. Final report

    SciTech Connect

    DeLafosse, P.H.; Tibbitts, G.A.; Black, A.D.; DiBona, B.G.

    1983-08-01

    The work done during the fifth and final phase of a program to improve downhole drilling motor bearing and seals is described. The principal activities in this phase were: (a) testing seals with abrasive-laden mud on the low-pressure side; (b) test second and third generation designs of both elastomeric chevron seals and Teflon U-seals; and (c) testing a full-scale bearing/seal package. Several operating parameters which have a radical effect on seal life were identified, and some promising designs and materials were tested.

  7. Enhanced Oil Recovery with Downhole Vibrations Stimulation in Osage County, Oklahoma

    SciTech Connect

    J. Ford Brett; Robert V. Westermark

    2001-09-30

    This Technical Quarterly Report is for the reporting period July 1, 2001 to September 30, 2001. The report provides details of the work done on the project entitled ''Enhanced Oil Recovery with Downhole Vibration Stimulation in Osage County Oklahoma''. The project is divided into nine separate tasks. Several of the tasks are being worked on simultaneously, while other tasks are dependent on earlier tasks being completed. The vibration stimulation well is permitted as Well 111-W-27, section 8 T26N R6E Osage County Oklahoma. It was spud July 28, 2001 with Goober Drilling Rig No. 3. The well was drilled to 3090-feet cored, logged, cased and cemented. The Rig No.3 moved off August 6, 2001. Phillips Petroleum Co. has begun analyzing the cores recovered from the test well. Standard porosity, permeability and saturation measurements will be conducted. They will then begin the sonic stimulation core tests Calumet Oil Company, the operator of the NBU, has begun to collect both production and injection wells information to establish a baseline for the project in the pilot field test area. Green Country Submersible Pump Company, a subsidiary of Calumet Oil Company, will provide both the surface equipment and downhole tools to allow the Downhole Vibration Tool to be operated by a surface rod rotating system. The 7-inch Downhole Vibration Tool (DHVT) has been built and is ready for initial shallow testing. The shallow testing will be done in a temporarily abandoned well operated by Calumet Oil Co. in the Wynona waterflood unit. The data acquisition doghouse and rod rotating equipment have been placed on location in anticipation of the shallow test in Well No.20-12 Wynona Waterflood Unit. A notice of invention disclosure was submitted to the DOE Chicago Operations Office. DOE Case No.S-98,124 has been assigned to follow the documentation following the invention disclosure. A paper covering the material presented to the Oklahoma Geologic Survey (OGS)/DOE Annual Workshop in

  8. Downhole tool for use with a ball and seat traveling valve for a fluid pump

    SciTech Connect

    Spears, H.L.

    1989-07-18

    This paper describes a downhole tool for use with a ball and seat travelling valve associated with a movable plunger, having upper and lower ends, for pumping well fluids. It comprises: an upper housing; a lower housing adapted to be associated with the upper end of the plunger; and means for causing relative movement between the upper and lower housings and abutment of the upper housing against the lower housing to impart a bumping force to the plunger during the downward movement of the plunger, whereby the ball is moved from its seat to permit the passage of well fluids through the travelling valve.

  9. Analysis of Data from a Downhole Oil/Water Separator Field Trial in East Texas

    SciTech Connect

    Veil, John A.; Layne, Arthur Langhus

    2001-04-19

    Downhole oil/water separator (DOWS) technology is available to separate oil from produced water at the bottom of an oil well. Produced water can be injected directly to a disposal formation rather than lifting it to the surface, treating it there, and reinjecting it. Because of a lack of detailed performance data on DOWS systems, the U.S. Department of Energy (DOE) provided funding to secure DOWS performance data. A large U.S. oil and gas operator offered to share its data with Argonne National Laboratory. This report summarizes data from the DOWS installation in eastern Texas.

  10. Downhole steam-generator study. Volume 1: Conception and feasibilty evaluation

    NASA Astrophysics Data System (ADS)

    1982-06-01

    A feasibility evaluation of a downhill steam generator was performed by the Rocketdyne Division of Rockwell International, under contract to Sandia National Laboratories, from September 1978 to September 1980. The study was conducted in four phases: (1) selection of a preliminary system design, (2) parametric analysis of the selected system, (3) experimental studies to demonstrate feasibility and develop design data, and (4) development of a final system design based on the parametric and experimental results. The feasibility of a low pressure combustion, indirect contact, downhole steam generator system was demonstrated. Key results from all phases of the study are presented herein.

  11. Active cooling for downhole instrumentation: design criteria and conceptual design summary

    SciTech Connect

    Bennett, G.A.

    1986-05-01

    This report summarizes the results of a literature survey that describes successful tests of geophysical instruments and their thermal protection systems. The conditions to which an instrument is subjected are formulated into relevant thermal and mechanical design criteria that have proved useful for improving passive thermal protection systems and selecting the preliminary feasibility of active refrigeration systems. A brief summary of the results of a series of conceptual designs on seven different active refrigeration systems is given. The systems are ranked according to feasibility for use in downhole active cooling applications.

  12. Ventilation Onset Prior to Umbilical Cord Clamping (Physiological-Based Cord Clamping) Improves Systemic and Cerebral Oxygenation in Preterm Lambs

    PubMed Central

    Polglase, Graeme R.; Dawson, Jennifer A.; Kluckow, Martin; Gill, Andrew W.; Davis, Peter G.; te Pas, Arjan B.; Crossley, Kelly J.; McDougall, Annie; Wallace, Euan M.; Hooper, Stuart B.

    2015-01-01

    Background As measurement of arterial oxygen saturation (SpO2) is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known. Aim We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs. Methods Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2) were measured continuously in apnoeic preterm lambs (126±1 day gestation). Positive pressure ventilation was initiated either 1) prior to umbilical cord clamping, or 2) after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping. Results Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5–6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping. Conclusion The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room. PMID:25689406

  13. Ventilation onset prior to umbilical cord clamping (physiological-based cord clamping) improves systemic and cerebral oxygenation in preterm lambs.

    PubMed

    Polglase, Graeme R; Dawson, Jennifer A; Kluckow, Martin; Gill, Andrew W; Davis, Peter G; Te Pas, Arjan B; Crossley, Kelly J; McDougall, Annie; Wallace, Euan M; Hooper, Stuart B

    2015-01-01

    As measurement of arterial oxygen saturation (SpO2) is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known. We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs. Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2) were measured continuously in apnoeic preterm lambs (126±1 day gestation). Positive pressure ventilation was initiated either 1) prior to umbilical cord clamping, or 2) after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping. Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5-6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping. The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room.

  14. Nonlinear response of a clamped-clamped beam with internal resonance under sinusoidal excitation

    NASA Astrophysics Data System (ADS)

    Afaneh, Abdul-Hafiz Ahmed

    1992-01-01

    The nonlinear response characteristics of a clamped-clamped beam is investigated analytically, numerically, and experimentally. The beam is under an initial static axial load and subjected to a harmonic excitation of its support. Two ranges of the axial load are considered. These are below (the beam is initially straight) and above Euler buckling load (the beam is initially buckled). Hamilton's principle is used to derive a fourth order partial differential equation of motion which is descritized and reduced to a set of second order ordinary differential equations by applying Galerkin's method. Under certain values of the static load, the normal modes are nonlinearly coupled and this coupling results in a fourth order internal resonance condition between the first three modes when the beam is initially straight. Second and third order internal resonance conditions occur between the first two modes for the case of initially buckled beam. The multiple scales method showed the significant effects of these internal resonance conditions on the system behavior. In the straight beam case, the third mode which is externally excited transfers energy to the first two modes within a small range of internal detuning. Outside this region, the response is governed by a unimodal response of the third mode. In the neighborhood of 1:1 internal resonance, it is found that within the region of two mode interaction, the solution is either stationary or nonstationary depending on the excitation level and system parameters. Saturation and jump phenomena are found to take place in the case of two mode interaction with 2:1 internal resonance. Numerical simulation and experimental testing confirmed these predictions and revealed the occurrence of multifurcation, snap-through (escaping from one well to the other in an irregular manner), and chaotic motion.

  15. Overproduction and purification of RFC-related clamp loaders and PCNA-related clamps from Saccharomyces cerevisiae.

    PubMed

    Bylund, Göran O; Majka, Jerzy; Burgers, Peter M J

    2006-01-01

    The replication clamp PCNA and its loader RFC (Replication Factor C) are central factors required for processive replication and coordinated DNA repair. Recently, several additional related clamp loaders have been identified. These alternative clamp loaders contain the small Rfc2-5 subunits of RFC, but replace the large Rfc1 subunit by a pathway-specific alternative large subunit, Rad24 for the DNA damage checkpoint, Ctf18 for the establishment of sister chromatid cohesion, and Elg1 for a general function in chromosome stability. In order to define biochemical functions for these loaders, the loaders were overproduced in yeast and purified at a milligram scale. To aid in purification, the large subunit of each clamp loader was fused to a GST-tag that, after purification could be easily removed by a rhinoviral protease. This methodology yielded all clamp loaders in high yield and with high enzymatic activity. The yeast 9-1-1 checkpoint clamp, consisting of Rad17, Mec3, and Ddc1, was overproduced and purified in a similar manner.

  16. VLBA Monitoring of 3C 273 and 3C 279 During INTEGRAL Campaigns

    NASA Astrophysics Data System (ADS)

    Savolainen, T.; Wiik, K.; Valtaoja, E.

    2004-10-01

    The gamma-ray blazars 3C 273 and 3C 279 were ob- served with the Very Long Baseline Array (VLBA) over seven epochs during the year 2003 as a part of support- ing observations for two INTEGRAL campaigns targeted on these sources. The VLBA observations were carried out in a full multi-wavelength polarimetric mode yield- ing total and polarized intensity maps at six frequencies ranging from 5 to 86 GHz. The VLBA maps probe the emission of the parsec scale jets in the angular scales of 0.1 - 50 mas, providing information about the dynam- ical state of the jets close to the central engine. As the gamma-ray emission above 100 keV is likely to be jet related, the co-ordinated VLBA observations give a pos- sibility to correlate the gamma-ray flux variations with the structural changes in the jet and, furthermore, with the flux and spectral variations of the individual syn- chrotron emitting components. Possible correlations can help to pinpoint the region where the gamma-ray emis- sion originates, and also establish the source of seed pho- tons for the inverse Compton process. We describe here the VLBA observations and present the first fully cali- brated maps together with a preliminary analysis.

  17. Spectral infrared hemispherical reflectance measurements for LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Wood, Bobby E.; Cromwell, Brian K.; Pender, Charles W.; Shepherd, Seth D.

    1992-01-01

    This paper describes infrared hemispherical reflectance measurements (2-15 microns) that were made on 58 chromic acid anodized tray clamps retrieved from the LDEF spacecraft. These clamps were used for maintaining the experiments in place and were located at various locations about the spacecraft. Changes in reflectance of the tray clamps at these locations were compared with atomic oxygen fluxes at the same locations. A decrease in absorption band depth was seen for the surfaces exposed to space indicating that there was some surface layer erosion. In all of the surfaces measured, little evidence of contamination was observed and none of the samples showed evidence of the brown nicotine stain that was so prominent in other experiments. Total emissivity values were calculated for both exposed and unexposed tray clamp surfaces. Only small differences, usually less than 1 percent, were observed. The spectral reflectances were measured using a hemi-ellipsoidal mirror reflectometer matched with an interferometer spectrometer. The rapid scanning capability of the interferometer allowed the reflectance measurements to be made in a timely fashion. The ellipsoidal mirror has its two foci separated by 2 inches and located on the major axis. A blackbody source was located at one focus while the tray clamp samples were located at the conjugate focus. The blackbody radiation was modulated and then focused by the ellipsoid onto the tray clamps. Radiation reflected from the tray clamp was sampled by the interferometer by viewing through a hole in the ellipsoid. A gold mirror (reflectance approximately 98 percent) was used as the reference surface.

  18. Spectral infrared hemispherical reflectance measurements for LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Wood, Bobby E.; Cromwell, Brian K.; Pender, Charles W.; Shepherd, Seth D.

    1992-01-01

    This paper describes infrared hemispherical reflectance measurements (2-15 microns) that were made on 58 chromic acid anodized tray clamps retrieved from the LDEF spacecraft. These clamps were used for maintaining the experiments in place and were located at various locations about the spacecraft. Changes in reflectance of the tray clamps at these locations were compared with atomic oxygen fluxes at the same locations. A decrease in absorption band depth was seen for the surfaces exposed to space indicating that there was some surface layer erosion. In all of the surfaces measured, little evidence of contamination was observed and none of the samples showed evidence of the brown nicotine stain that was so prominent in other experiments. Total emissivity values were calculated for both exposed and unexposed tray clamp surfaces. Only small differences, usually less than 1 percent, were observed. The spectral reflectances were measured using a hemi-ellipsoidal mirror reflectometer matched with an interferometer spectrometer. The rapid scanning capability of the interferometer allowed the reflectance measurements to be made in a timely fashion. The ellipsoidal mirror has its two foci separated by 2 inches and located on the major axis. A blackbody source was located at one focus while the tray clamp samples were located at the conjugate focus. The blackbody radiation was modulated and then focused by the ellipsoid onto the tray clamps. Radiation reflected from the tray clamp was sampled by the interferometer by viewing through a hole in the ellipsoid. A gold mirror (reflectance approximately 98 percent) was used as the reference surface.

  19. Measuring beta-cell function relative to insulin sensitivity in youth: Does the hyperglycemic clamp suffice?

    USDA-ARS?s Scientific Manuscript database

    To compare beta-cell function relative to insulin sensitivity, disposition index (DI), calculated from two clamps (2cDI, insulin sensitivity from the hyperinsulinemic-euglycemic clamp and first-phase insulin from the hyperglycemic clamp) with the DI calculated from the hyperglycemic clamp alone (hcD...

  20. Downhole measurements in the AND-1B borehole, ANDRILL McMurdo Ice Shelf Project, Antarctica

    USGS Publications Warehouse

    Morin, R.; Williams, T.; Henrys, S.; Crosby, T.; Hansaraj, D.

    2007-01-01

    A comprehensive set of downhole measurements was collected in the AND-1B drillhole as part of the on-ice scientific programme defined for the McMurdo Ice Shelf (MIS) Project. Geophysical logs were recorded over two operation phases and consisted of calliper, temperature, fluid conductivity, induction resistivity, magnetic susceptibility, natural gamma activity, acoustic televiewer, borehole deviation, and dipmeter. In addition, two standard vertical seismic profiles (VSP) and one walk-away VSP were obtained. Radioactive logs (porosity and density) were not run because of unstable borehole conditions. Although the total depth of the hole is 1285 metres below seafloor (mbsf), the depth range for in situ measurements was limited by the length of the wireline (1018 mbsf) and by the nullification of some geophysical logs due to the presence of steel casing. A depth correction was derived to account for systematic discrepancies in depth between downhole measurements and cores; consequently, log responses can be directly compared to core properties. The resulting data are amenable to studies of cyclicity and climate, heat flux and fluid flow, and stricture and stress. When integrated with physical properties and fractures measured on the core, this information should play a significant role in addressing many of the scientific objectives of the ANDRILL programme.

  1. Large-diameter waveguide Bragg grating components and their application in downhole oil and gas sensing

    NASA Astrophysics Data System (ADS)

    MacDougall, Trevor W.; Sanders, Paul E.

    2004-12-01

    A new class of Bragg grating components based on large diameter cylindrical waveguides has been commercially released. Unique properties of the waveguide including grating fabrication, low loss splicing to optical fibers, and specialized machining for optimization in sensor applications are reported. The waveguide structure enables packaging of Bragg gratings that overcomes attachment, mechanical creep, and hermeticity problems commonly associated with fiber Bragg gratings. This enables exceptionally robust Bragg grating sensor transducers well suited for the high temperature, corrosive downhole environment of oil and gas. Sensor transducers have been demonstrated showing no measurable drift or error after over 4-year aging tests at 150°C. More than 50 pressure/temperature installations have been successfully completed and are operational, delivering real-time data cumulatively over 500,000 operation hours. These systems integrate a range of support components specific to in-well oil and gas applications, such as downhole cables, interconnects, and platform instruments. This optical sensing platform, coupled with other optical techniques, has been extended beyond optical pressure/temperature measurements to distributed temperature measurements, multiphase flow, and in-well seismic sensing. These systems have been successfully deployed in multi-zonal, multi-parameter system architectures. This sensing technology is integrated with in-well controls, data acquisition and interpretation, and reservoir modeling. This systems approach is required to close the value loop of intelligent completions in oil and gas production.

  2. Downhole microseismic monitoring for low signal-to-noise ratio events

    NASA Astrophysics Data System (ADS)

    Zhou, Hang; Zhang, Wei; Zhang, Jie

    2016-10-01

    Microseismic monitoring plays an important role in the process of hydraulic fracturing for shale gas/oil production. The accuracy of event location is an essential issue in microseismic monitoring. The data obtained from downhole monitoring system usually show a higher signal-to-noise ratio (SNR) than the recorded data from the surface. For small microseismic events, however, P waves recorded in a downhole array may be very weak, while S waves are generally dominant and strong. Numerical experiments suggest that inverting S-wave arrival times alone is not sufficient to constrain event locations. In this study, we perform extensive location tests with various noise effects using a grid search method that matches the travel time data of the S wave across a recording array. We conclude that fitting S-wave travel time data along with at least one P-wave travel time of the same event can significantly improve location accuracy. In practice, picking S-wave arrival time data and at least one P-wave pick is possible for many small events. We demonstrate that fitting the combination of the travel time data is a robust approach, which can help increase the number of microseismic events to be located accurately during hydraulic fracturing.

  3. Discovery of the Eureka volcanogenic massive sulphide lens using downhole electromagnetics

    NASA Astrophysics Data System (ADS)

    Paggi, Jacob; Macklin, Daniel

    2016-05-01

    The Eureka volcanogenic massive sulphide (VMS) lens forms part of the Stockman Project in north-east Victoria. Eureka was discovered in early 2013, heralding the first new VMS mineralised zone to be discovered at the project since 1979. Key drivers to the detection of Eureka included the combination of downhole electromagnetics (EM) and a robust geological model. The lens is located 350 m to the north-east of the Currawong deposit, at a vertical depth of 360 m. Surface EM methods played a significant role in the discovery of the nearby Currawong and Wilga deposits during the late 1970s. Despite this, modern day airborne and fixed-loop transient EM (FLTEM) surveys failed to detect Eureka, most likely due to its depth, moderate conductance and loop-edge effects masking anomalies. The key component in discovering the lens was the interpretation of two subtle downhole transient electromagnetics (DHTEM) responses from 2012 exploration drillholes. These responses were further strengthened by structural and short wave infrared modelling, presenting a compelling multi-component drill target. The lens was discovered soon thereafter, with a discovery intercept of 22.65 m at 1.2% Cu, 0.7% Pb, 3.9% Zn, 43 g/t Ag and 1.3 g/t Au.

  4. Fabrication, assembly, bench and drilling tests of two prototype downhole pneumatic turbine motors: Final technical report

    SciTech Connect

    Bookwalter, R.; Duettra, P.D.; Johnson, P.; Lyons, W.C.; Miska, S.

    1987-04-01

    The first and second prototype downhole pneumatic turbine motors have been fabricated, assembled and tested. All bench tests showed that the motor will produce horsepower and bit speeds approximating the predicted values. Specifically, the downhole pneumatic turbine motor produced approximately 50 horsepower at 100 rpm, while being supplied with about 3600 SCFM of compressed air. The first prototype was used in a drilling test from a depth of 389 feet to a depth of 789 feet in the Kirtland formation. This first prototype motor drilled at a rate exceeding 180 ft/hr, utilizing only 3000 SCFM of compressed air. High temperature tests (at approximately 460/sup 0/F) were carried out on the thrust assembly and the gearboxes for the two prototypes. These components operated successfully at these temperatures. Although the bench and drilling tests were successful, the tests revealed design changes that should be made before drilling tests are carried out in geothermal boreholes at the Geysers area, near Santa Rosa, California.

  5. Reservoir characterization of marine and permafrost associated gas hydrate accumulations with downhole well logs

    USGS Publications Warehouse

    Collett, T.S.; Lee, M.W.

    2000-01-01

    Gas volumes that may be attributed to a gas hydrate accumulation depend on a number of reservoir parameters, one of which, gas-hydrate saturation, can be assessed with data obtained from downhole well-logging devices. This study demonstrates that electrical resistivity and acoustic transit-time downhole log data can be used to quantify the amount of gas hydrate in a sedimentary section. Two unique forms of the Archie relation (standard and quick look relations) have been used in this study to calculate water saturations (S(w)) [gas-hydrate saturation (S(h)) is equal to (1.0 - S(w))] from the electrical resistivity log data in four gas hydrate accumulations. These accumulations are located on (1) the Blake Ridge along the Southeastern continental margin of the United States, (2) the Cascadia continental margin off the pacific coast of Canada, (3) the North Slope of Alaska, and (4) the Mackenzie River Delta of Canada. Compressional wave acoustic log data have also been used in conjunction with the Timur, modified Wood, and the Lee weighted average acoustic equations to calculate gas-hydrate saturations in all four areas assessed.

  6. Geothermal well cements: current status of R and D and downhole testing

    SciTech Connect

    Kukacka, L.E.

    1981-11-01

    The status as of October 1981 of the program to develop and test geothermal well cementing materials. The program represents the most comprehensive and thorough examination of the geothermal cementing problem undertaken thus far. To date, 27 cements identified in an R and D phase of the program or supplied by industry have been evaluated in laboratory tests. Sixteen of these materials were selected for downhole investigations currently in progress in Mexico at Cerro Prieto. Data for 3 months exposures to flowing brine at 210{sup 0}C are available. Most of the cements continue to meet the strength and permeability acceptance criteria. These results should be reassuring to operators who are using such slurries. Further evaluations are planned after 6 and 12 months exposures. Contingent upon these results, tests will be initiated at 350{sup 0}C. Since many of the cements were formulated specifically for use at temperatures above 300/sup 0/C, it is expected that significant property improvements may be observed as the downhole temperature is increased.

  7. Enhanced Oil Recovery with Downhole Vibration Stimulation in Osage County Oklahoma

    SciTech Connect

    J. Ford Brett; Robert V. Westermark

    2000-09-30

    This Technical Quarterly Report is for the reporting period July 1, 2000 to September 30, 2000. The report provides details of the work done on the project entitled ''Enhanced Oil Recovery with Downhole Vibration Stimulation in Osage County Oklahoma''. The project is divided into nine separate tasks. Since this is the first Quarterly report, much of the work done is of a preliminary nature. Several of the tasks are being worked on simultaneously, while other tasks are dependent on earlier tasks being completed. The selection of the pilot test area has been completed. The drilling of the test well is waiting on rig availability. Phillips has begun sonic core testing of offset cores, waiting on the core from the well to be drilled. Design work is progressing for the tool, which will be built to fit the test well. Installation of monitoring equipment and the downhole vibration tool will occur after the well is drilled. Technical transfer efforts have begun with the submission of an abstract for a technical paper for the Oklahoma City Society of Petroleum Engineers meeting in March 2001.

  8. Subsurface exploration using bucket auger borings and down-hole geologic inspection

    SciTech Connect

    Scullin, C.M. )

    1994-03-01

    The down-hole geologic inspection of 24 in. bucket auger borings has been a hands-on technique for collecting valuable geologic structural and lithologic detail in southern California investigations for over 35 yr. Although it has been used for all types of investigations for hillside urban development, it is of particular benefit in landslide investigations and evaluations. The benefits of down-hole geologic inspection during detailed mapping of large landslide complexes with multiple slide planes are discussed in this paper. Many of the geotechnical investigations of these massive landslide complexes have been very limited in their determinations of accurate landslide parameters and very deficient in proper engineering analysis while based upon this limited data. This has resulted in many cases where the geotechnical consultant erroneously concludes that ancient landslides don't move and it is all right to build upon them, even though they have neither justified the landslide parameters, nor the slope stability or safety. Because this author and the many consultants contacted during the preparation of this paper were not aware of other publications regarding this method of collecting detailed geologic data, this author included the safety considerations, safety equipment, the cost and the Cal OSHA requirements for entering exploration shafts.

  9. Element for use in an inductive coupler for downhole drilling components

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Dahlgren, Scott; Fox, Joe; Sneddon, Cameron

    2006-08-29

    The present invention includes an element for use in an inductive coupler in a downhole component. The element includes a plurality of ductile, generally U-shaped leaves that are electrically conductive. The leaves are less than about 0.0625" thick and are separated by an electrically insulating material. These leaves are aligned so as to form a generally circular trough. The invention also includes an inductive coupler for use in downhole components, the inductive coupler including an annular housing having a recess with a magnetically conductive, electrically insulating (MCEI) element disposed in the recess. The MCEI element includes a plurality of segments where each segment further includes a plurality of ductile, generally U-shaped electrically conductive leaves. Each leaf is less than about 0.0625" thick and separated from the otherwise adjacent leaves by electrically insulating material. The segments and leaves are aligned so as to form a generally circular trough. The inductive coupler further includes an insulated conductor disposed within the generally circular trough. A polymer fills spaces between otherwise adjacent segments, the annular housing, insulated conductor, and further fills the circular trough.

  10. Downhole measurements and fluid chemistry of a castle rock steam well, the Geysers, Lake County, California

    USGS Publications Warehouse

    Truesdell, A.H.; Nathenson, M.; Frye, G.A.

    1981-01-01

    Wellbore and reservoir processes in a steam well in the Castle Rock field of The Geysers have been studied by means of down-hole pressure and temperature measurements and analyses of ejected water and steam produced under bleed and full flow. Down-hole measurements show that below a vapor zone there is liquid water in the well in pressure equilibrium with reservoir steam at a depth of 2290 m. The progressive decreases, from 1973 to 1977, of pressure and temperature in the vapor zone indicate that wellbore heat loss is high enough to condense a large fraction of the steam inflow. The chemical composition of water ejected from the well is consistent with an origin from wellbore condensation of steam. Calculations using the differences in gas and isotopic compositions between bleed and full-flow steam show that about half of the full-flow steam originated as liquid water in the reservoir and that about 30% of the steam entering the well under bleed was condensed in the wellbore and drained downward. Heat loss calculations are also consistent with this amount of condensation. ?? 1981.

  11. [Delayed cord clamping in the interest of the newborn child].

    PubMed

    Scherjon, S A; Smit, Y

    2008-06-21

    The importance of delayed cord clamping, both for the preterm and for the term newborn, for the prevention ofneonatal anaemia (during the neonatal period and/or at the age of3 months) and furthermore to reduce the need of blood transfusions, has recently been demonstrated in controlled clinical studies and meta-analyses. Physiological and pathophysiological factors also provide a rationale for delayed cord clamping: neonatal blood volume may increase by 32% if cord clamping is delayed until the umbilical cord has completely stopped pulsating. A slow transition, involving closure of the ductus arteriosus and the foramen ovale cordis and gradual filling of the neonatal systemic circulation, contributes to the opening of the alveoli due to perfusion of the alveolar capillaries. No disadvantages, such as polycythaemia or hyperbilirubinaemia, have been described with regard to preterm neonates, whereas the incidence of intracranial haemorrhages is reduced. Also for the mother, no disadvantages of late clamping have been determined. As a standard procedure, the baby's umbilical cord should not be clamped until at least 3 minutes have passed. One should wait at least 30 seconds during the birth of children for whom a more active approach is necessary. Of all people, these children will benefit from a good Hb level.

  12. Dynamic Clamp in Cardiac and Neuronal Systems Using RTXI

    PubMed Central

    Ortega, Francis A.; Butera, Robert J.; Christini, David J.; White, John A.; Dorval, Alan D.

    2016-01-01

    The injection of computer-simulated conductances through the dynamic clamp technique has allowed researchers to probe the intercellular and intracellular dynamics of cardiac and neuronal systems with great precision. By coupling computational models to biological systems, dynamic clamp has become a proven tool in electrophysiology with many applications, such as generating hybrid networks in neurons or simulating channelopathies in cardiomyocytes. While its applications are broad, the approach is straightforward: synthesizing traditional patch clamp, computational modeling, and closed-loop feedback control to simulate a cellular conductance. Here, we present two example applications: artificial blocking of the inward rectifier potassium current in a cardiomyocyte and coupling of a biological neuron to a virtual neuron through a virtual synapse. The design and implementation of the necessary software to administer these dynamic clamp experiments can be difficult. In this chapter, we provide an overview of designing and implementing a dynamic clamp experiment using the Real-Time eXperiment Interface (RTXI), an open- source software system tailored for real-time biological experiments. We present two ways to achieve this using RTXI’s modular format, through the creation of a custom user-made module and through existing modules found in RTXI’s online library. PMID:25023319

  13. Automated ion channel screening: patch clamping made easy.

    PubMed

    Farre, Cecilia; Stoelzle, Sonja; Haarmann, Claudia; George, Michael; Brüggemann, Andrea; Fertig, Niels

    2007-04-01

    Efficient high resolution techniques are required for screening efforts and research targeting ion channels. The conventional patch clamp technique, a high resolution but low efficiency technique, has been established for 25 years. Recent advances have opened up new possibilities for automated patch clamping. This new technology meets the need of drug developers for higher throughput and facilitates new experimental approaches in ion channel research. Specifically, Nanion's electrophysiology workstations, the Port-a-Patch and the Patchliner, have been successfully introduced as high-quality automated patch clamp platforms for industry as well as academic users. Both platforms give high quality patch clamp recordings, capable of true giga-seals and stable recordings, accessible to the user without the need for years of practical training. They also offer sophisticated experimental possibilities, such as accurate and fast ligand application, temperature control and internal solution exchange. This article describes the chip-based patch clamp technology and its usefulness in ion channel drug screening and academic research.

  14. Axon voltage-clamp simulations. I. Methods and tests.

    PubMed Central

    Moore, J W; Ramón, F; Joyner, R W

    1975-01-01

    This is the first in a series of four papers in which we present the numerical simulation of the application of the voltage clamp technique to excitable cells. In this paper we describe the application of the Crank-Nicolson (1947) method for the solution of the parabolic partial differential equations that describe a cylindrical cell in which the ionic conductances are functions of voltage and time (Hodgkin and Huxley, 1952). This method is compared with other methods in terms of accuracy and speed of solution for a propagated action potential. In addition, differential equations representing a simple voltage-clamp electronic circuit are presented. Using the voltage clamp circuit equations, we simulate the voltage clamp of a single isopotential membrane patch and show how the parameters of the circuit affect the transient response of the patch to a step change in the control potential.The stimulation methods presented in this series of papers allow the evaluation of voltage clamp control of an excitable cell or a syncytium of excitable cells. To the extent that membrane parameters and geometrical factors can be determined, the methods presented here provide solutions for the voltage profile as a function of time. PMID:1174640

  15. Linking downhole logging data with geology and drilling /coring operations - Example from Chicxulub Expedition 364.

    NASA Astrophysics Data System (ADS)

    Lofi, Johanna; Smith, Dave; Delahunty, Chris; Le Ber, Erwan; Mellet, Claire; Brun, Laurent; Henry, Gilles; Paris, Jehanne

    2017-04-01

    Expedition 364 was a joint IODP/ICDP mission specific platform expedition to explore the Chicxulub impact crater buried below the Yucatán continental shelf. In April and May 2016, our Expedition drilled a single borehole at Site M0077A into the crater's peak ring. It allowed recovering 303 excellent quality cores from 505.7 to 1334.7 meters below sea floor and acquiring more than 5.8 km of high resolution open hole logs. Downhole logs are rapidly collected, continuous with depth, and measured in situ; these data are classically interpreted in terms of stratigraphy, lithology, porosity, fluid content, geochemical composition and structure of the formation drilled. Downhole logs also allow assessing borehole quality (eg. shape and trajectory), and can provide assistance for decision support during drilling operations. In this work, Expedition 364 downhole logs are used to improve our understanding of the drilling/coring operation history. Differentiating between natural geological features and borehole artifacts are also critical for data quality assessment. The set of downhole geophysical tools used during Expedition 364 was constrained by the scientific objectives, drilling/coring technique, hole conditions and temperature at the drill site. Wireline logging data were acquired with slimline tools in three logging phases at intervals 0-503, 506-699 and 700-1334 mbsf. Logs were recorded either with standalone logging tools or, for the first time in IODP, with stackable slimline tools. Log data included total gamma radiation, sonic velocity, acoustic and optical borehole images, resistivity, conductivity, magnetic susceptibility, caliper and borehole fluid parameters. The majority of measurements were performed in open borehole conditions. During the drilling operations some problems were encountered directly linked to the geology of the drilled formation. For example, two zones of mud circulation losses correlate in depth with the presence of karst cavities or open

  16. Effect of sterilization on stiffness and dimensional stability of rubber-dam clamps.

    PubMed

    Giebink, D L; Mathieu, G P; Hondrum, S O

    1996-01-01

    Simulated clinical conditions were used to test the effect of sterilization on rubber-dam clamp stiffness and dimension. Sixty Hygienic and Ivory W7 clamps were either steam or dry heat sterilized and compared to controls. Stiffness and dimensional change between Ivory clamp groups was significant (p<.0001); the sterilized clamps showed less change than the controls. Hygienic groups showed a significant different between the control and dry heat groups (p<.05); the sterilized clamps showed less change than the controls. The change in stiffness and interjaw width for all Ivory clamps compared to all Hygienic clamps was significant (p<.0001). The Hygienic clamps changes less than the Ivory clamps. The results indicate that steam and dry heat sterilization do not affect retention of rubber-dam clamps.

  17. 3C-SiC microdisk mechanical resonators with multimode resonances at radio frequencies

    NASA Astrophysics Data System (ADS)

    Lee, Jaesung; Zamani, Hamidrera; Rajgopal, Srihari; Zorman, Christian A.; X-L Feng, Philip

    2017-07-01

    We report on the design, modeling, fabrication and measurement of single-crystal 3C-silicon carbide (SiC) microdisk mechanical resonators with multimode resonances operating at radio frequencies (RF). These microdisk resonators (center-clamped on a vertical stem pedestal) offer multiple flexural-mode resonances with frequencies dependent on both disk and anchor dimensions. The resonators are made using a novel fabrication method comprised of focused ion beam nanomachining and hydroflouic : nitric : acetic (HNA) acid etching. Resonance peaks (in the frequency spectrum) are detected through laser-interferometry measurements. Resonators with different dimensions are tested, and multimode resonances, mode splitting, energy dissipation (in the form of quality factor measurement) are investigated. Further, we demonstrate a feedback oscillator based on a passive 3C-SiC resonator. This investigation provides important guidelines for microdisk resonator development, ranging from an analytical prediction of frequency scaling law to fabrication, suggesting RF microdisk resonators can be good candidates for future sensing applications in harsh environments.

  18. Umbilical cord clamping. An analysis of a usual neonatological conduct.

    PubMed

    Papagno, L

    1998-01-01

    Here we described a critical analysis of the neonatological procedure of early cord clamping, meaning this, within 40 seconds after birth. Fifty three cases are here analysed, in which this practice was not performed, but instead a late umbilical cord clamping was done after birth or after the cord had stopped beating. Variations in hematocrito values within 24 to 36 hours after birth were studied. A transitory polycithemia, with a maximum peak 12 hours post-delivery was observed. These values returned to normal levels between 24 and 36 hours after birth. K vitamin was not administered to any of the newborns. No pathology appeared related to this transitory polycithemia. In can be concluded that the late umbilical cord clamping represents no risk to the new-born and that the pathological phenomena described under these circumstances may be attributed to the increase in K vitamin dependent coagulation factors that are induced by the routinary administration of phitonadione to all normal newborns.

  19. Using physiology to guide time to cord clamping.

    PubMed

    Kluckow, Martin; Hooper, Stuart B

    2015-08-01

    Immediate clamping and cutting of the umbilical cord at birth has been the accepted standard of care for decades. The physiologic rationale relating umbilical cord clamping (UCC) to the events of the circulatory transition is not considered in arbitrarily recommended cord clamping times. Systematic review of early versus deferred UCC shows significant hemodynamic benefits to the deferred group. Mechanisms for this protective effect are considered in this review. The original concept of a placental transfusion with a volume load and prevention of low cardiac output relies on the physiological end point of the amount of blood transfused. The newer concept of an ordered physiological transition is increasingly supported. This model places aeration of the lungs and an increase in pulmonary blood flow back at the centre of the circulatory transition with timing of UCC being related to establishment of respiration. The need for "physiologically based" UCC is discussed. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  20. [Advantage of delayed umbilical cord clamping in the newborn infant].

    PubMed

    Menget, A; Mougey, C; Thiriez, G; Riethmuller, D

    2013-09-01

    The timing of umbilical cord clamping remains controversial. Although most maternity wards use the early clamping (5-15s), randomized studies and meta-analyses have demonstrated the benefit of delayed clamping for term and preterm newborn infants over the past 10 years. Indeed, placentofetal transfusion of 20-30 ml/kg in 2-3 min improves the iron status of term infants and prevents infant hypochromic anemia. Infant anemia is a public health problem in many developing countries. For preterm newborns, placental transfusion for 45 s or milking the cord for 15 s improves cardiovascular adaptation, with better hemodynamic stability, as well as decreased intraventricular hemorrhages, need for transfusion, and late-onset sepsis. A new look at this symbolic act is needed and professionals need to be persuaded of the importance of the "wait a minute" policy for a better physiological delivery.

  1. New redshift determinations for three 3C radio sources.

    NASA Astrophysics Data System (ADS)

    Reynaldi, V.

    2017-01-01

    I report the new redshift determinations of three radio sources 3C 196.1, 3C 268.2 and 3C 303.1 by using GMOS/Gemini North long-slit optical spectroscopy. The details of the observations are summarized in the following table (the B600 grating was used for the three observations): Object | RA(J2000) | DEC(J2000) | Date of obs. | width-slit(arcsec) | PA(deg) | Exp.Time(sec) 3C 196.1 | 8:15:27.8 | -03:08:27 | Mar 2012 | 0.5 | 50 | 2560 3C 268.2| |12:00:59.1 | 31:33:28 | Feb 2011 | 0.5 | 165 | 2576 3C 303.1 | 14:43:14.5 | 77:07:28 | Feb 2012 | 1 | 145 | 2560 The three of the sources have extended regions of ionized gas that do not obey a spherical distribution.

  2. Poliovirus protease 3C(pro) kills cells by apoptosis.

    PubMed

    Barco, A; Feduchi, E; Carrasco, L

    2000-01-20

    The tetracycline-based Tet-Off expression system has been used to analyze the effects of poliovirus protease 3C(pro) on human cells. Stable HeLa cell clones that express this poliovirus protease under the control of an inducible, tightly regulated promoter were obtained. Tetracycline removal induces synthesis of 3C protease, followed by drastic morphological alterations and cellular death. Degradation of cellular DNA in nucleosomes and generation of apoptotic bodies are observed from the second day after 3C(pro) induction. The cleavage of poly(ADP-ribose) polymerase, an enzyme involved in DNA repair, occurs after induction of 3C(pro), indicating caspase activation by this poliovirus protease. The 3C(pro)-induced apoptosis is blocked by the caspase inhibitor z-VAD-fmk. Our findings suggest that the protease 3C is responsible for triggering apoptosis in poliovirus-infected cells by a mechanism that involves caspase activation. Copyright 2000 Academic Press.

  3. Extended Optical Flaring of the Blazar 3C 279

    NASA Astrophysics Data System (ADS)

    Turner, C. S.; Miller, H. R.

    2017-03-01

    The blazar, 3C 279, was previously reported to be undergoing a major optical outburst (ATEL#10121 and ATEL#10161). We report optical observations of 3C 279 on March 19 when it was observed with the 24-inch telescope at Georgia State University's Hard Labor Creek Observatory with R=13.46+/-0.01 mag. These observations indicate that 3C 279 continues to be in an extremely bright state.

  4. Plasma temperature clamping in filamentation laser induced breakdown spectroscopy

    SciTech Connect

    Harilal, Sivanandan S.; Yeak, J.; Phillips, Mark C.

    2015-10-19

    Ultrafast laser filament induced breakdown spectroscopy is a very promising method for remote material detection. We present characteristics of plasmas generated in a metal target by laser filaments in air. Our measurements show that the temperature of the ablation plasma is clamped along the filamentation channel due to intensity clamping in a filament. Nevertheless, significant changes in radiation intensity are noticeable, and this is essentially due to variation in the number density of emitting atoms. The present results also partly explains the reason for the occurrence of atomic plume during fs LIBS in air compared to long-pulse ns LIBS.

  5. DIHeDRAL: Downhole Regolith Interrogation with He-assisted Drill and Laser Induced Breakdown Spectroscopy System

    NASA Astrophysics Data System (ADS)

    Moreschini, P.; Rutberg, M.; Zacny, K.; Paulsen, G.

    2010-03-01

    We describe DIHeDRAL, a downhole LIBS system designed to be integrated into a 3m-class drill, currently under development at Honeybee Robotics. DiHeDRAL allows subsurface access providing information on the composition of lunar soil.

  6. Program for the Improvement of Downhole Drilling-Motor Bearings and Seals. Phase III, Part 2: final report

    SciTech Connect

    Not Available

    1980-03-01

    Six months of activity to improve downhole drilling-motor bearings and seals for geothermal applications are reported. The following are covered: seal testing and evaluation, bearing-seal package testing and evaluation, lubricant testing and evaluation, and program status, plans and schedule. (MHR)

  7. Improved analysis of transient temperature data from permanent down-hole gauges (PDGs)

    NASA Astrophysics Data System (ADS)

    Zhang, Yiqun; Zheng, Shiyi; Wang, Qi

    2017-08-01

    With the installation of permanent down-hole gauges (PDGs) during oil field development, large volumes of high resolution and continuous down-hole information are obtainable. The interpretation of these real-time temperature and pressure data can optimize well performance, provide information about the reservoir and continuously calibrate the reservoir model. Although the dynamic temperature data have been interpreted in practice to predict flow profiling and provide characteristic information of the reservoir, almost all of the approaches rely on established non-isothermal models which depend on thermodynamic parameters. Another problem comes from the temperature transient analysis (TTA), which is underutilized compared with pressure transient analysis (PTA). In this study, several model-independent methods of TTA were performed. The entire set of PDG data consists of many flow events. By utilizing the wavelet transform, the exact points of flow-rate changes can be located. The flow regime changes, for example, from early time linear flow to later time pseudo-radial flow, among every transient period with constant flow-rate. For the early time region (ETR) that is caused by flow-rate change operations, the TTA, along with the PTA can greatly reduce the uncertainties in flow regime diagnosis. Then, the temperature variations during ETR were examined to infer the true reservoir temperature history, and the relationships between the wavelet detailed coefficients and the flow-rate changes were analysed. For the scenarios with constant reservoir-well parameters, the detailed flow-rate history can be generated by calculating the coefficient of relationship in advance. For later times, the flow regime changes to pseudo-radial flow. An analytical solution was introduced to describe the sand-face temperature. The formation parameters, such as permeability and skin factor, were estimated with the previously calculated flow-rate. It is necessary to analyse temperature

  8. Enhanced Oil Recovery with Downhole Vibration Stimulation in Osage County, Oklahoma

    SciTech Connect

    J. Ford Brett; Robert V. Westermark

    2002-06-30

    This Technical Quarterly Report is for the reporting period March 31, 2002 to June 30, 2002. The report provides details of the work done on the project entitled ''Enhanced Oil Recovery with Downhole Vibration Stimulation in Osage County Oklahoma''. The project is divided into nine separate tasks. Several of the tasks are being worked on simultaneously, while other tasks are dependent on earlier tasks being completed. The vibration stimulation Well 111-W-27 is located in section 8 T26N R6E of the North Burbank Unit (NBU), Osage County Oklahoma. It was drilled to 3090-feet cored, logged, cased and cemented. The rig moved off August 6, 2001. Phillips Petroleum Co. has performed several core studies on the cores recovered from the test well. Standard porosity, permeability and saturation measurements have been conducted. In addition Phillips has prepared a Core Petrology Report, detailing the lithology, stratigraphy and sedimentology for Well 111-W27, NBU. Phillips has also conducted the sonic stimulation core tests, the final sonic stimulation report has not yet been released. Calumet Oil Company, the operator of the NBU, began collecting both production and injection wells information to establish a baseline for the project in the pilot field test area since May 2001. The original 7-inch Downhole Vibration Tool (DHVT) has been thoroughly tested and it has been concluded that it needs to be redesigned. An engineering firm from Fayetteville AR has been retained to assist in developing a new design for the DHVT. The project participants requested from the DOE, a no-cost extension for the project through December 31, 2002. The no-cost extension amendment to the contract was signed during this reporting period. A technical paper SPE 75254 ''Enhanced Oil Recovery with Downhole Vibration Stimulation, Osage County, Oklahoma'' was presented at the 2002 SPE/DOE Thirteenth Symposium on Improved Oil Recovery, in Tulsa OK, April 17, 2002. A one-day short course was conducted at

  9. Field test of two high-pressure, direct-contact downhole steam generators. Volume I. Air/diesel system

    SciTech Connect

    Marshall, B.W.

    1983-05-01

    As a part of the Project DEEP STEAM to develop technology to more efficiently utilize steam for the recovery of heavy oil from deep reservoirs, a field test of a downhole steam generator (DSG) was performed. The DSG burned No. 2 diesel fuel in air and was a direct-contact, high pressure device which mixed the steam with the combustion products and injected the resulting mixture directly into the oil reservoir. The objectives of the test program included demonstration of long-term operation of a DSG, development of operational methods, assessment of the effects of the steam/combustion gases on the reservoir and comparison of this air/diesel DSG with an adjacent oxygen/diesel direct contact generator. Downhole operation of the air/diesel DSG was started in June 1981 and was terminated in late February 1982. During this period two units were placed downhole with the first operating for about 20 days. It was removed, the support systems were slightly modified, and the second one was operated for 106 days. During this latter interval the generator operated for 70% of the time with surface air compressor problems the primary source of the down time. Thermal contact, as evidenced by a temperature increase in the production well casing gases, and an oil production increase were measured in one of the four wells in the air/diesel pattern. Reservoir scrubbing of carbon monoxide was observed, but no conclusive data on scrubbing of SO/sub x/ and NO/sub x/ were obtained. Corrosion of the DSG combustor walls and some other parts of the downhole package were noted. Metallurgical studies have been completed and recommendations made for other materials that are expected to better withstand the downhole combustion environment. 39 figures, 8 tables.

  10. Mex3c mutation reduces adiposity and increases energy expenditure.

    PubMed

    Jiao, Yan; George, Sunil K; Zhao, Qingguo; Hulver, Matthew W; Hutson, Susan M; Bishop, Colin E; Lu, Baisong

    2012-11-01

    The function of MEX3C, the mammalian homolog of Caenorhabditis elegans RNA-binding protein muscle excess 3 (MEX-3), was unknown until our recent report that MEX3C is necessary for normal postnatal growth and enhances the expression of local bone Igf1 expression. Here we report the pivotal role of Mex3c in energy balance regulation. Mex3c mutation caused leanness in both heterozygous and homozygous transgenic mice, as well as a more beneficial blood glucose and lipid profile in homozygous transgenic mice, in both sexes. Although transgenic mice showed normal food intake and fecal lipid excretion, they had increased energy expenditure independent of physical activity. Mutant mice had normal body temperature, Ucp1 expression in brown adipose tissue, and muscle and liver fatty acid oxidation. Mex3c is expressed in neurons and is detectable in the arcuate nucleus, the ventromedial nucleus, and the dorsomedial nucleus of the hypothalamus. Mex3c was not detected in NPY or POMC neurons but was detected in leptin-responsive neurons in the ventromedial nucleus. Mex3c and Leptin double mutant mice were growth retarded and obese and had blood profiles similar to those of ob/ob mice but showed none of the steatosis observed in ob/ob mice. Our data show that Mex3c is involved in energy balance regulation.

  11. 21 CFR 882.5175 - Carotid artery clamp.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carotid artery clamp. 882.5175 Section 882.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... (the principal artery in the neck that supplies blood to the brain) and has a removable...

  12. 21 CFR 882.5175 - Carotid artery clamp.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carotid artery clamp. 882.5175 Section 882.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... (the principal artery in the neck that supplies blood to the brain) and has a removable adjusting...

  13. 21 CFR 882.5175 - Carotid artery clamp.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carotid artery clamp. 882.5175 Section 882.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... (the principal artery in the neck that supplies blood to the brain) and has a removable adjusting...

  14. 21 CFR 882.5175 - Carotid artery clamp.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carotid artery clamp. 882.5175 Section 882.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... (the principal artery in the neck that supplies blood to the brain) and has a removable adjusting...

  15. 21 CFR 882.5175 - Carotid artery clamp.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carotid artery clamp. 882.5175 Section 882.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... (the principal artery in the neck that supplies blood to the brain) and has a removable adjusting...

  16. Clamp provides efficient connection for high-density currents

    NASA Technical Reports Server (NTRS)

    Mc Carthy, J. R.; Trebes, D. M.

    1967-01-01

    Electrical connector clamp /bus bar/ gives high contact-surface efficiency for providing a high current to thin wall stainless steel tubing containing hydrogen gas. It uses lead solder film to provide the electrical equivalent of a fusion bond without degrading the grain structure, permitting disassembly and reuse of the components.

  17. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Cable clamps and grips. 18.40 Section 18.40 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design...

  18. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Cable clamps and grips. 18.40 Section 18.40 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design...

  19. Do not overlook an umbilical cord hernia before clamping.

    PubMed

    Cizmeci, Mehmet Nevzat; Kanburoglu, Mehmet Kenan; Akelma, Ahmet Zulfikar; Tatli, Mustafa Mansur

    2013-08-01

    An umbilical cord hernia is a rare midline abdominal defect. These masses may be easily overlooked at birth, which may result in an intestinal injury due to careless proximal application of the cord clamp. Herein, we present a newborn infant with an umbilical cord hernia who was managed by primary closure of the lesion.

  20. Beyond the patch clamp: nanotechnologies for intracellular recording.

    PubMed

    Kruskal, Peter B; Jiang, Zhe; Gao, Teng; Lieber, Charles M

    2015-04-08

    The patch clamp is a fundamental tool for neuroscientists, offering insights that have shaped our understanding of the brain. Advances in nanotechnology suggest that the next generation of recording methods is now within reach. We discuss the complexity and future promise of applying nanoscience to neural recording. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Robotic partial nephrectomy with selective parenchymal compression (Simon clamp).

    PubMed

    Castillo, O A; Rodriguez-Carlin, A; Lopez-Fontana, G; Aleman, E

    2013-01-01

    To present our initial experience using selective renal parenchymal ischemia, without hilar clamping, in robotic-assisted partial nephrectomy. In four patients with T1a renal tumor we performed robotic-assisted partial nephrectomy, using the Simon's clamp (Aesculap). It provides selective parenchymal compression without the need of vascular clamping. All patients had exofitic renal tumors in polar location. Renal parenchymal reconstruction was done as the standard technique. The median age was 49.6 years (42-59), 3 male and 1 female patient. Median operative time was 71,6 minutes (40-120). Mean stimated bleeding was 250 ml (50-400). Average tumor size was 3,25 cm (1,5-5,3). There were no complications and the average hospital stay was 3,5 days (1-7). The pathology was informed as renal cell carcinoma in three patients and one hemorrhagic cyst. The surgical margins were negative. Our preliminary results shows that selective renal parenchymal compression, with the Simon's clamp, provides an alternative to vascular control in selected patients with polar renal tumors. Copyright © 2012 AEU. Published by Elsevier Espana. All rights reserved.

  2. A band clamp with a spring toggle lever

    NASA Technical Reports Server (NTRS)

    Simmonds, M.

    1974-01-01

    Clamp could have several applications, as it provides tolerance for both expansion and contraction. It might be useful with firemen's breathing apparatus and luggage racks and other freight-carrying equipment. Also, using same piece as handle and spring reduces production costs by reducing number of parts.

  3. Stem drive oil recovery method utilizing a downhole steam generator and anti clay-swelling agent

    SciTech Connect

    Hopkins, D. N.; Snavely, E. S.

    1985-06-11

    Viscous oil is recovered from a subterranean, viscous oil-containing formation by a steam flooding technique wherein steam is generated in a downhole steam generator located in an injection well by spontaneous combustion of a pressurized mixture of a water-soluble fuel such as sugars and alcohols dissolved in water or a stable hydrocarbon fuel-in-water emulsion containing an anti clay-swelling agent and substantially pure oxygen. The generated mixture of steam and combustion gases pass through the formation, displacing oil and reducing the oil's viscosity and the mobilized oil is produced from the formation via a spaced-apart production well. Suitable anti clay-swelling agents include metal halide salts and diammonium phosphate.

  4. DOE/GRI development and testing of a downhole pump for jet-assist drilling

    SciTech Connect

    1995-07-01

    The objective of this project is to accelerate development and commercialization of a high pressure downhole pump (DHP{trademark}) to be used for ultra-high pressure, jet-assisted drilling. The purpose of jet-assisted drilling is to increase the rate of penetration (ROP) in the drilling of deeper gas and oil wells where the rocks become harder and more difficult to drill. As a means to accomplishing this objective, a second generation commercial prototype of a DHP is to be designed, fabricated, tested in the laboratory, and eventually tested in the field. The design of the DOE commercial prototype DHP is current in progress. The layout of the complete DHP is expected to be completed by mid-April. Fabrication and laboratory experimentation is expected to be completed in September. Pending successful completion of the laboratory testing phase, the DOE commercial DHP should be ready for testing in the field by the end of the calendar year.

  5. Near-surface attenuation using traffic-induced seismic noise at a downhole array

    NASA Astrophysics Data System (ADS)

    Dikmen, S. Umit; Pinar, Ali; Edincliler, Ayse

    2016-01-01

    A novel approach is developed for estimating the near-surface attenuation using seismic noise recordings at a downhole array. The amplitude spectrum of the traffic-induced seismic noise at the engineering bedrock level exhibits a high-frequency decay between 10 and 40 Hz. Subsequently, it yields a Kappa value of 14 ± 3 ms and a quality factor of 45 ± 10 for the profile between the highway and the sensor. Likewise, using the earthquake recordings made at the surface and the engineering bedrock levels, the Kappa values are calculated as 60 and 45 ms, respectively. The difference was attributed to near-surface attenuation where the upgoing earthquake waves and the downgoing traffic-induced seismic waves traverse similar soil profiles resulting in similar Kappa values. Hence, the near-site geology attenuation properties can be derived using the seismic noise data induced by a known source at a close distance recorded at engineering bedrock level.

  6. Harsh-Environment Solid-State Gamma Detector for Down-hole Gas and Oil Exploration

    SciTech Connect

    Peter Sandvik; Stanislav Soloviev; Emad Andarawis; Ho-Young Cha; Jim Rose; Kevin Durocher; Robert Lyons; Bob Pieciuk; Jim Williams; David O'Connor

    2007-08-10

    The goal of this program was to develop a revolutionary solid-state gamma-ray detector suitable for use in down-hole gas and oil exploration. This advanced detector would employ wide-bandgap semiconductor technology to extend the gamma sensor's temperature capability up to 200 C as well as extended reliability, which significantly exceeds current designs based on photomultiplier tubes. In Phase II, project tasks were focused on optimization of the final APD design, growing and characterizing the full scintillator crystals of the selected composition, arranging the APD device packaging, developing the needed optical coupling between scintillator and APD, and characterizing the combined elements as a full detector system preparing for commercialization. What follows is a summary report from the second 18-month phase of this program.

  7. Downhole fiber optic sensing: the oilfield service provider's perspective: from the cradle to the grave

    NASA Astrophysics Data System (ADS)

    Skinner, Neal G.; Maida, John L.

    2014-06-01

    For almost three decades, interest has continued to increase with respect to the application of fiber-optic sensing techniques for the upstream oil and gas industry. This paper reviews optical sensing technologies that have been and are being adopted downhole, as well as their drivers. A brief description of the life of a well, from the cradle to the grave, and the roles fiber-optic sensing can play in optimizing production, safety, and protection of the environment are also presented. The performance expectations (accuracy, resolution, stability, and operational lifetime) that oil companies and oil service companies have for fiber-optic sensing systems is described. Additionally, the environmental conditions (high hydrostatic pressures, high temperatures, shock, vibration, crush, and chemical exposure) that these systems must tolerate to provide reliable and economically attractive oilfield monitoring solutions are described.

  8. Downhole fluid injection systems, CO2 sequestration methods, and hydrocarbon material recovery methods

    DOEpatents

    Schaef, Herbert T.; McGrail, B. Peter

    2015-07-28

    Downhole fluid injection systems are provided that can include a first well extending into a geological formation, and a fluid injector assembly located within the well. The fluid injector assembly can be configured to inject a liquid CO2/H2O-emulsion into the surrounding geological formation. CO2 sequestration methods are provided that can include exposing a geological formation to a liquid CO2/H2O-emulsion to sequester at least a portion of the CO2 from the emulsion within the formation. Hydrocarbon material recovery methods are provided that can include exposing a liquid CO2/H2O-emulsion to a geological formation having the hydrocarbon material therein. The methods can include recovering at least a portion of the hydrocarbon material from the formation.

  9. Solvent removes downhole NORM-contaminated BaSO{sub 4} scale

    SciTech Connect

    Ford, W.G.F.; Gadeken, L.L.; Callahan, T.J.; Jackson, D.

    1996-04-22

    A research project in Canada recently demonstrated that a solvent can remove barium sulfate (BaSO{sub 4}) scales, and all radioactive material is left downhole, eliminating costly NORM disposal. Each year, scale precipitation costs operators millions of dollars in maintenance, treatment, and lost production. Scale contaminated with naturally occurring radioactive material (NORM) creates further problems because NORM scales fall under strict and expensive disposal guidelines. Highly insoluble BaSO{sub 4} scales can be difficult to treat because radioactive materials often incorporate into the scale as it forms. BaSO{sub 4} scales have had to be removed by mechanical scraping or reaming, which is troublesome and costly. The strict regulations concerning disposal of NORM scale add to the costs of the treatment. This paper describes an innovative handling and disposal method for these NORM materials.

  10. Behavior of a hollow core photonic crystal fiber under high radial pressure for downhole application

    SciTech Connect

    Sadeghi, J. Chenari, Z.; Ziaee, F.; Latifi, H.; Santos, J. L.

    2014-02-17

    Pressure fiber sensors play an important role in downhole high pressure measurements to withstand long term operation. The purpose of this paper is to present an application of hollow core photonic crystal fiber (HC-PCF) as a high pressure sensor head for downhole application based on dispersion variation. We used a high pressure stainless steel unit to exert pressure on the sensor. The experimental results show that different wavelengths based on sagnac loop interferometer have additive sensitivities from 5 × 10{sup −5} nm/psi at 1480 nm to 1.3 × 10{sup −3} nm/psi at 1680 nm. We developed a simulation to understand the reason for difference in sensitivity of wavelengths and also the relationship between deformation of HC-PCF and dispersion variation under pressure. For this purpose, by using the finite element method, we investigated the effect of structural variation of HC-PCF on spectral transformation of two linear polarizations under 1000 psi pressure. The simulation and experimental results show exponential decay behavior of dispersion variation from −3.4 × 10{sup −6} 1/psi to −1.3 × 10{sup −6} 1/psi and from −5 × 10{sup −6} 1/psi to −1.8 × 10{sup −6} 1/psi, respectively, which were in a good accordance with each other.

  11. A conceptual model for kappa (κ) based on downhole earthquake records

    NASA Astrophysics Data System (ADS)

    Ktenidou, O. J.; Abrahamson, N. A.; Drouet, S.; Cotton, F.

    2015-12-01

    At high frequencies, the acceleration spectral amplitude decreases rapidly; this has been modeled with the spectral decay factor κ (Anderson and Hough, 1984). Its site-specific component, κ0, an index of site attenuation in the upper crust, is used widely today in ground motion prediction and simulation. Here we use accelerometric data from the EUROSEISTEST valley, a geologically complex and seismically active region in Greece. The strong motion array consists of 14 surface and 6 downhole stations. Site conditions across the stations vary greatly, ranging from soft sediments to hard rock (NEHRP class D to A). We use the results to improve our physical understanding of κ0 and propose a conceptual model of κ0 with Vs. This model comprises two new notions. On the one hand, and contrary to existing correlations, we observe that κ0 stabilizes for high Vs values. This may indicate the existence of regional κ0 values for hard rock. If so, we propose that borehole measurements (which have almost never been used up to now for κ0) may be useful in determining these values. On the other hand, we find that material damping in the soil column, as expressed through travel times, does not suffice to account for the total κ0 measured at the surface. We propose that, apart from material damping, additional site attenuation may be caused by scattering from small-scale variability in the profile. If this is so, then geotechnical damping measurements may not suffice to infer the overall attenuation underneath a site; but starting with a regional value (possibly measured from a downhole station) and adding damping, we might define a lower bound for site-specific κ0. More precise estimates would necessitate seismological site instrumentation.

  12. System to inject steam and produce oil from the same wellbore through downhole valve switching

    SciTech Connect

    Not Available

    1992-01-01

    Various Downhole Equipment systems have been designed for typical applications in three California Oilfields,based on well data gathered from three different Operating Companies. The first system, applicable to a 2,000 ft deep reservoir (Monarch) a highly underpressured, unconsolidated sand of 200 ft net pay, located in the Midway-Sunset field, is based on the use of a new well. The second well configuration considered was the re-entry into an existing well equipped with a 7 inches casing and penetrating into two separate sandstone reservoirs, at normal pressures in the North Antelope Hills field. Only the bottom layer is presently in production through a gravel-packed 5.5 inch linear, while the upper zone is behind the cemented casing. The third case studied was the re-entry into an existing well equipped with an 8 5/8 inch casing, presently unperforated, into a thin under-pressured sand reservoir (Weber) in the Midway-Sunset field. All three California fields contain Heavy Oils of different but relatively high viscosities. A new class of potential applications of our new technology has also been considered: the recovery of Light Oil (> 20 API) by steam injection in under-pressured Carbonate reservoirs which lay at depths beyond the economic limit for conventional steam injection technology. The possibility of including this application in a Field Test proposal to the DOE, under the Class II Oil Program, is now under review by various Operators. A drilling contractor experienced in drilling multiple horizontal wells in Carbonate reservoirs and a team of reservoir engineers experienced in the recovery of Light Oil by steam in fractured reservoirs have expressed their interest in participating in such a joint Field Project. Laboratory tests on specific prototypes of Downhole Sealing Elements are underway.

  13. Downhole Microseismic Monitoring at a Carbon Capture, Utilization, and Storage Site, Farnsworth Unit, Ochiltree County, Texas

    NASA Astrophysics Data System (ADS)

    Ziegler, A.; Balch, R. S.; van Wijk, J.

    2015-12-01

    Farnsworth Oil Field in North Texas hosts an ongoing carbon capture, utilization, and storage project. This study is focused on passive seismic monitoring at the carbon injection site to measure, locate, and catalog any induced seismic events. A Geometrics Geode system is being utilized for continuous recording of the passive seismic downhole bore array in a monitoring well. The array consists of 3-component dual Geospace OMNI-2400 15Hz geophones with a vertical spacing of 30.5m. Downhole temperature and pressure are also monitored. Seismic data is recorded continuously and is produced at a rate of over 900GB per month, which must be archived and reviewed. A Short Term Average/Long Term Average (STA/LTA) algorithm was evaluated for its ability to search for events, including identification and quantification of any false positive events. It was determined that the algorithm was not appropriate for event detection with the background level of noise at the field site and for the recording equipment as configured. Alternatives are being investigated. The final intended outcome of the passive seismic monitoring is to mine the continuous database and develop a catalog of microseismic events/locations and to determine if there is any relationship to CO2 injection in the field. Identifying the location of any microseismic events will allow for correlation with carbon injection locations and previously characterized geological and structural features such as faults and paleoslopes. Additionally, the borehole array has recorded over 1200 active sources with three sweeps at each source location that were acquired during a nearby 3D VSP. These data were evaluated for their usability and location within an effective radius of the array and were stacked to improve signal-noise ratio and are used to calibrate a full field velocity model to enhance event location accuracy. Funding for this project is provided by the U.S. Department of Energy under Award No. DE-FC26-05NT42591.

  14. Gauging the feasibility of a downhole energy harvesting system through a proof-of-concept study

    NASA Astrophysics Data System (ADS)

    Kjolsing, Eric; Todd, Michael

    2016-04-01

    Hydrocarbon well operators deploy downhole reservoir monitoring equipment in order to optimize the rate at which hydrocarbons are extracted. Alternative power sources are sought that could be deployed in these harsh environments to replace or supplement standard power sources currently in use. To this end, a three phase proof-of-concept study was performed to gauge the feasibility of such a device. In the first phase a parametric study was performed to understand how high uncertainty variables affect the natural frequency of a producing hydrocarbon well. In a follow up study, the relationship between boundary conditions and system damping was investigated. In the second phase a structural housing was designed to satisfy American Petroleum Institute load cases. Using finite element models and standard tube/casing geometries, design pressures were iterated until a permissible housing design was achieved. This preliminary design provided estimates of the radial width and volume in which energy harvesting and storage elements may be situated. In the last phase a software program was developed to estimate the energy that might be harvested from user specified harvester configurations. The program is dependent on user input production tube accelerations; this permits well operators to use well-specific vibrational data as inputs to generate well-specific energy output estimates. Results indicate that a downhole energy harvesting tool is structurally feasible under reasonable operating conditions but no conclusions can be made as to the sufficiency of generated power as no in-situ acceleration time histories are available. Future work is discussed. Approved for publication, LA-UR-16-21193.

  15. On baseline determination and gas saturation derivation from downhole electrical monitoring of shallow biogenic gas production

    NASA Astrophysics Data System (ADS)

    Pezard, P. A.; Celerier, B. P.

    2015-12-01

    Adequate hydrogeophysical monitoring of CO2 geological storage remains a challenge as different parameters might be modified during storage. That implies to compare real-time measurements to an adequate baseline. At the Maguelone shallow experimental site a representative baseline for electrical resistivity was built from a large number of downhole geophysical measurements recorded over time. At this coastal site this issue is particularly important due to the production of biogenic gas at shallow depth (< 200 m) from the subsurface sediments.For this, a modified petrophysical model based on the Waxman-Smits model is proposed to estimate gas saturation found to vary up to 7% within shallow sand layers, indicating that natural gas production within the sedimentary pile from biological activity cannot be neglected during gas injection experiments. In the two main reservoirs located at shallow depth (R1 and R2), a variable gas content of 7% and 4% was obtained over short periods of time in the TLL6 and DSO1 boreholes, respectively. The difference might be due to the gentle stratigraphic slope identified from cross hole log and core analyses, TLL6 being located upslope from DSO1. This study also revealed a rapid dynamic mechanism resulting in transfer of biogenic gas from the bottom reservoir (R1) to the top one (R2), possibly due to gas leaking along some of the monitoring boreholes. These sand-rich layers constitute buffer reservoirs for biogenic gases before being released to the atmosphere. Future studies at Maguelone will first focus on biogenic gas sampling from a downhole multi-packer completion in order to identify and quantify the different gas phases produced over time by the sedimentary pile.

  16. Seismic refraction and downhole velocity surveys for investigation of the Tinemaha Dam Inyo County, California

    SciTech Connect

    Olson, M.; Inel, S.; Prashar, Y.

    1997-10-01

    Seismic refraction and downhole velocity surveys were conducted as part of a geotechnical investigation of the Tinemaha Dam. Thirteen P and S-wave velocity surveys were conducted concurrently with cone penetration testing along the crest and downstream toe of this dam. One additional velocity survey was conducted from a borehole on the crest of the dam using a downhole geophone array. The shear wave velocities estimated for the dam and its underlying alluvium ranged from 345 to 2008 ft/sec. A depth profile of these velocities indicates areas within the dam and its foundation where the shear wave velocities are less than 600 ft/sec. These velocity estimates were used with other geotechnical data, to calculate the dynamic elastic moduli for the dam and its foundation, to evaluate the stability of the dam in the event of a local earthquake on the Owens Valley fault. To further investigate the location of this active strike-slip fault, seismic refraction surveys were conducted at two locations. The first refraction survey was positioned south of the dam across the expected trend of the Owens Valley fault. A velocity analysis of the upper refracting horizon was conducted using the generalized reciprocal method. This revealed changes in lateral velocity that were interpreted as due to a fault-transition from saturated alluvium to volcanic bedrock. The second survey was positioned along the dam`s crest at the west abutment to help locate a possible fault beneath this area. The interpreted depth section from this survey locates a point where the deeper bedrock unit appears to be truncated by faulting. This information will help locate additional boreholes to evaluate lithologic conditions.

  17. An improved vaseline gap voltage clamp for skeletal muscle fibers

    PubMed Central

    1976-01-01

    A Vaseline gap potentiometric recording and voltage clamp method is developed for frog skeletal muscle fibers. The method is based on the Frankenhaeuser-Dodge voltage clamp for myelinated nerve with modifications to improve the frequency response, to compensate for external series resistance, and to compensate for the complex impedance of the current-passing pathway. Fragments of single muscle fibers are plucked from the semitendinosus muscle and mounted while depolarized by a solution like CsF. After Vaseline seals are formed between fluid pools, the fiber ends are cut once again, the central region is rinsed with Ringer solution, and the feedback amplifiers are turned on. Errors in the potential and current records are assessed by direct measurements with microelectrodes. The passive properties of the preparation are simulated by the "disk" equivalent circuit for the transverse tubular system and the derived parameters are similar to previous measurements with microelectrodes. Action potentials at 5 degrees C are long because of the absence of delayed rectification. Their shape is approximately simulated by solving the disk model with sodium permeability in the surface and tubular membranes. Voltage clamp currents consist primarily of capacity currents and sodium currents. The peak inward sodium current density at 5 degrees C is 3.7 mA/cm2. At 5 degrees C the sodium currents are smoothly graded with increasing depolarization and free of notches suggesting good control of the surface membrane. At higher temperatures a small, late extra inward current appears for small depolarizations that has the properties expected for excitation in the transverse tubular system. Comparison of recorded currents with simulations shows that while the transverse tubular system has regenerative sodium currents, they are too small to make important errors in the total current recorded at the surface under voltage clamp at low temperature. The tubules are definitely not under voltage

  18. Rediscovering sperm ion channels with the patch-clamp technique

    PubMed Central

    Kirichok, Yuriy; Lishko, Polina V.

    2011-01-01

    Upon ejaculation, mammalian spermatozoa have to undergo a sequence of physiological transformations within the female reproductive tract that will allow them to reach and fertilize the egg. These include initiation of motility, hyperactivation of motility and perhaps chemotaxis toward the egg, and culminate in the acrosome reaction that permits sperm to penetrate the protective vestments of the egg. These physiological responses are triggered through the activation of sperm ion channels that cause elevations of sperm intracellular pH and Ca2+ in response to certain cues within the female reproductive tract. Despite their key role in sperm physiology and their absolute requirement for the process of fertilization, sperm ion channels remain poorly understood due to the extreme difficulty in application of the patch-clamp technique to spermatozoa. This review covers the topic of sperm ion channels in the following order: first, we discuss how the intracellular Ca2+ and pH signaling mediated by sperm ion channels controls sperm behavior during the process of fertilization. Then, we briefly cover the history of the methodology to study sperm ion channels, which culminated in the recent development of a reproducible whole-cell patch-clamp technique for mouse and human cells. We further discuss the main approaches used to patch-clamp mature mouse and human spermatozoa. Finally, we focus on the newly discovered sperm ion channels CatSper, KSper (Slo3) and HSper (Hv1), identified by the sperm patch-clamp technique. We conclude that the patch-clamp technique has markedly improved and shifted our understanding of the sperm ion channels, in addition to revealing significant species-specific differences in these channels. This method is critical for identification of the molecular mechanisms that control sperm behavior within the female reproductive tract and make fertilization possible. PMID:21642646

  19. Clamped-filament elongation model for actin-based motors.

    PubMed Central

    Dickinson, Richard B; Purich, Daniel L

    2002-01-01

    Although actin-based motility drives cell crawling and intracellular locomotion of organelles and certain pathogens, the underlying mechanism of force generation remains a mystery. Recent experiments demonstrated that Listeria exhibit episodes of 5.4-nm stepwise motion corresponding to the periodicity of the actin filament subunits, and extremely small positional fluctuations during the intermittent pauses [S. C. Kuo and J. L. McGrath. 2000. Nature. 407:1026-1029]. These findings suggest that motile bacteria remain firmly bound to actin filament ends as they elongate, a behavior that appears to rule out previous models for actin-based motility. We propose and analyze a new mechanochemical model (called the "Lock, Load & Fire" mechanism) for force generation by means of affinity-modulated, clamped-filament elongation. During the locking step, the filament's terminal ATP-containing subunit binds tightly to a clamp situated on the surface of a motile object; in the loading step, actin.ATP monomer(s) bind to the filament end, an event that triggers the firing step, wherein ATP hydrolysis on the clamped subunit attenuates the filament's affinity for the clamp. This last step initiates translocation of the new ATP-containing terminus to the clamp, whereupon another cycle begins anew. This model explains how surface-tethered filaments can grow while exerting flexural or tensile force on the motile surface. Moreover, stochastic simulations of the model reproduce the signature motions of Listeria. This elongation motor, which we term actoclampin, exploits actin's intrinsic ATPase activity to provide a simple, high-fidelity enzymatic reaction cycle for force production that does not require elongating filaments to dissociate from the motile surface. This mechanism may operate whenever actin polymerization is called upon to generate the forces that drive cell crawling or intracellular organelle motility. PMID:11806905

  20. Midwives in India: a delayed cord clamping intervention using simulation.

    PubMed

    Faucher, M A; Riley, C; Prater, L; Reddy, M P

    2016-09-01

    Iron deficiency is a prevalent health problem in India affecting women and newborns. Delayed umbilical cord clamping at birth is a safe and effective means for increasing serum iron levels in newborns up to 6 months of age. The study aim was to increase the utilization of delayed cord clamping in a group of midwives working in Hyderabad, India. A single group pre- and post-test design was used to evaluate knowledge, beliefs and practice before and after a delayed cord clamping intervention including follow-up at 10 months after the original intervention. The intervention included lectures and simulation. Results show significant increases in knowledge and positive beliefs about the practice of delayed cord clamping. Simulation was effective for eliciting important feedback related to learning. Results represent a small group of midwives working with a non-profit foundation in Southern India. Language discordancy and cultural norms in this group of midwives may have influenced results. Knowledge, beliefs and practice related to delayed cord clamping were all significantly improved after the intervention. The Knowledge to Action framework using simulation is an effective cross-cultural method for implementing education about evidence-based practice. Midwives are invested in learning practices that promote public health. Changing institutional policy may have limitations without first considering normative practice. Using simulation combined with institutional health policy appears to result in significant uptake of practice change. Qualitative studies exploring the interconnections between cultural norms and decision making may be informative about promoting practice change particularly in this setting. Upscaling midwifery has been recommended to improve maternal and child health in India. © 2016 International Council of Nurses.

  1. Polarization states and dielectric responses of elastically clamped ferroelectric nanocrystals

    NASA Astrophysics Data System (ADS)

    Azovtsev, A. V.; Pertsev, N. A.

    2016-12-01

    Polarization states and physical properties of ferroelectrics depend on the mechanical boundary conditions due to electrostrictive coupling between electric polarization and lattice strains. Here, we describe theoretically both equilibrium thermodynamic states and electric permittivities of ferroelectric nanocrystals subjected to the elastic three-dimensional (3D) clamping by a surrounding dielectric material. The problem is solved by the minimization of a special thermodynamic potential that describes the case of an ellipsoidal ferroelectric inclusion embedded into a linear elastic matrix. Numerical calculations are performed for BaTiO3, PbTiO3, and Pb(Zr0.5Ti0.5)O3 nanoparticles surrounded by silica glass. It is shown that, in the case of BaTiO3 and PbTiO3, elastic 3D clamping may change the order of a ferroelectric phase transition from first to second. Furthermore, the mechanical inclusion-matrix interaction shifts the temperatures of structural transitions between different ferroelectric states and even eliminates some ferroelectric phases existing in stress-free BaTiO3 and Pb(Zr0.5Ti0.5)O3 crystals. Another important effect of elastic clamping is the lowering of the symmetry of ferroelectric states in ellipsoidal inclusions, where orthorhombic and monoclinic phases may form instead of the tetragonal and rhombohedral bulk counterparts. Finally, our thermodynamic calculations show that the dielectric responses of studied perovskite ferroelectrics are sensitive to matrix-induced clamping as well. For instance, dielectric peaks occurring at structural transitions between different ferroelectric phases in BaTiO3 appear to be much higher in spherical inclusions than in the freestanding crystal. Predicted clamping-induced enhancement of certain dielectric responses at room temperature indicates that composite materials comprising nanocrystals of perovskite ferroelectrics are promising for device applications requiring the use of high-permittivity dielectrics.

  2. Why Are C3-C4 Intermediate Species Rare?

    NASA Astrophysics Data System (ADS)

    Johnson, J. E.; Field, C. B.; Berry, J. A.

    2014-12-01

    While C3-C4 intermediate photosynthesis is thought to represent the evolutionary bridge between C3 and C4 photosynthesis, C3-C4 intermediate species are ecologically rare in comparison to both C3 and C4 species. Here, we report results from a laboratory experiment, field observations, and model simulations that suggest a new explanation for the ecological rarity of C3-C4 intermediate species. In the laboratory experiment, we combined gas exchange and fluorescence to characterize the temperature response of photosynthesis in three closely-related species in the genus Flaveria that are representatives of the C3, C3-C4 intermediate, and C4 photosynthetic pathways. The leaf temperature that maximized the quantum yield for CO2 assimilation (Topt(ΦCO2)) was 24.9 ± 0.7°C in Flaveria robusta (C3), 29.8 ± 1.0°C in F. chloraefolia (C3-C4), and 35.7 ± 0.8°C in F. bidentis (C4), and was linearly related to the temperature sensitivity of the coupling between CO2 assimilation and electron transport (d(ΦCO2/ ΦPSII)/dT)). While F. chloraefolia does not simultaneously occur with F. robusta and F. bidentis in naturally-assembled communities, this C3-C4 intermediate species does occur with other C3 and C4 species. During the growing season in two of these mixed-photosynthetic-type communities, leaf temperatures for F. chloraefolia were similar to the Topt(ΦCO2) determined in the laboratory. A model of maximum potential carbon gain suggests that competitive coexistence of C3, C3-C4 intermediate, and C4 species could be dependent on a temperature regime that highlights the distinct relative advantages of the C3-C4 intermediate pathway. In combination, these results suggest that the relative temperature sensitivity of the C3, C3-C4 intermediate, and C4 photosynthetic pathways combined with environmental variation in temperature may help to explain why C3-C4 intermediate species are generally rare.

  3. Vibration control of a flexible clamped-clamped plate based on an improved FULMS algorithm and laser displacement measurement

    NASA Astrophysics Data System (ADS)

    Xie, Lingbo; Qiu, Zhi-cheng; Zhang, Xian-min

    2016-06-01

    This paper presents a novel active resonant vibration control experiment of a flexible clamped-clamped plate using an improved filtered-U least mean square (FULMS) algorithm and laser displacement measurement. Different from the widely used PZT sensors or acceleration transducers, the vibration of the flexible clamped-clamped plate is measured by a non-contact laser displacement measurement sensor with higher measurement accuracy and without additional load to the plate. The conventional FULMS algorithm often uses fixed step size and needs reference signal related to the external disturbance signal. However, the fixed step size method cannot obtain a fast convergence speed and it will result in a low residual error. Thus, a variable step size method is investigated. In addition, it is difficult to extract reference signal related to the vibration source directly in the practical application. Therefore, it is practically useful that a reference signal is constructed by both the controller parameters and the vibration residual signal. The experimental results demonstrate that the improved FULMS algorithm has better vibration control effect than the proportional derivative (PD) feedback control algorithm and the fixed step-size control algorithm.

  4. The CX(3)C-chemokine fractalkine in kidney diseases.

    PubMed

    Koziolek, M J; Vasko, R; Bramlage, C; Müller, G A; Strutz, F

    2009-09-01

    The chemokine CX(3)C-L/FKN is expressed in both soluble and transmembrane/mucin hybrid forms, thus combining chemoattractant functions together with receptor/adhesion molecule properties. In contrast to other chemokine receptors, CX(3)C-R is expressed not only on lymphoid cell populations, but also on several intrinsic cells including tubular epithelial cells and renal fibroblasts where it regulates various aspects of cell viability, matrix synthesis and degradation, migration, inflammation as well as oxidative stress. In the kidney, the chemokines/receptor pair has been shown to play a role in nephrogenesis as well as in the pathogenesis primary and secondary nephropathies. In several animal models and human specimens with acute and chronic renal failure including allograft nephropathy, CX(3)C-L/CX(3)C-R has been shown to exert immune and non-immune mediated renal damages. A blockade of this chemokine system ameliorated acute and chronic renal damages, though the latter to a more robust extent. There seems to a role of the CX(3)C-L/CX(3)C-R pair in mediating acute renal inflammation as well as in progressive chronic renal failure. However, functional studies are lacking for many aspects and further studies are necessary to better define the functional properties of CX(3)C-L/FKN and its receptor.

  5. Mechanical properties and biological interaction of aortic clamps: are these all minimally invasive?

    PubMed

    Bianchi, Giacomo; Pucci, Angela; Matteucci, Marco; Varone, Egidio; Romano, Simone Lorenzo; Lionetti, Vincenzo; Glauber, Mattia

    2013-01-01

    Although specifically designed aortic clamps are mainstay of minimally invasive cardiac surgery, so far, no comparative reports about their mechanical properties and interaction with the aortic wall have been reported. In this study, the generated force in the clamps' jaws and the biological response of the aorta after clamping are evaluated. The jaw force of five commercially available clamps [Geister, Cygnet, Cardiovision (CV) 195.10, CV 195.40, and CV 195.83] was assessed by clamping a 2.2-mm compression load cell with a dedicated computer universal serial bus interface at the proximal, the middle, and the distal site from the fulcrum. Biological response of the aortic wall was assessed in five minipigs (weight, 38-40 kg) that underwent thoracic aorta clamping and leakage point test. Immunohistochemistry and morphometric analysis were carried out for each aortic segment tested. Force generation pattern is peculiar of each clamp, being higher in the proximal and the middle portion and lower in the distal part. One clamp (Cygnet) exhibited homogeneous maximal force generation at all three sites. All clamps exhibited peculiar crushing artifacts. A variable degree of endothelial layer disruption occurred in all clamping tests; three clamps (CV 195.10, Cygnet, and Geister) had the lower amount of intact endothelium. The clamping force was not associated with the degree of endothelial disruption (P value was not significant). The choice of a clamp that is not only minimally invasive in design but also least traumatic will help avoid complications of aortic manipulation.

  6. FLASH_TISA_Terra+Aqua_Version3C

    Atmospheric Science Data Center

    2017-06-14

    ... CERES Discipline:  Clouds Radiation Budget Version:  Version 3C Level:  ... Path Cloud Top Pressure Cloud Particle Phase Cloud Infrared Emissivity Cloud Base Pressure Surface (Radiative) Flux TOA ...

  7. Towards Large Area Growth of 3C-SiC

    SciTech Connect

    Vasiliauskas, Remigijus; Liljedahl, Rickard; Syvaejaervi, Mikael; Yakimova, Rositza

    2010-11-01

    In this work we have analyzed the possibility of upscaling the growth of 3C-SiC. The growth was done at different temperatures to find limiting mechanisms of the growth rate and to examine the morphology of grown layers. Coverage by 3C-SiC increases when increasing temperature, however more twins appeared. Activation energy of the growth is 130 kcal/mol--showing that growth rate limiting mechanism is sublimation of the source. We discuss the influence of large area 6H-SiC wafers on the formation of 3C-SiC, in which the change in basal plane orientation could also influence the growth of 3C-SiC.

  8. Distinct roles for ATP binding and hydrolysis at individual subunits of an archaeal clamp loader

    PubMed Central

    Seybert, Anja; Wigley, Dale B

    2004-01-01

    Circular clamps are utilised by replicative polymerases to enhance processivity. The topological problem of loading a toroidal clamp onto DNA is overcome by ATP-dependent clamp loader complexes. Different organisms use related protein machines to load clamps, but the mechanisms by which they utilise ATP are surprisingly different. Using mutant clamp loaders that are deficient in either ATP binding or hydrolysis in different subunits, we show how the different subunits of an archaeal clamp loader use ATP binding and hydrolysis in distinct ways at different steps in the loading process. Binding of nucleotide by the large subunit and three of the four small subunits is sufficient for clamp loading. However, ATP hydrolysis by the small subunits is required for release of PCNA to allow formation of the complex between PCNA and the polymerase, while hydrolysis by the large subunit is required for catalytic clamp loading. PMID:15014449

  9. Timing of umbilical cord clamping: effect on iron endowment of the newborn and later iron status.

    PubMed

    Chaparro, Camila M

    2011-11-01

    The optimal timing of umbilical cord clamping has been debated in the scientific literature for at least the last century, when cord clamping practices shifted from delayed towards immediate clamping. Recent research provides evidence for the beneficial effect of delayed cord clamping on infant iron status. The present review describes the physiological basis for the impact of cord clamping time on total body iron at birth and the relationship between birth body iron, as affected by cord clamping time, and iron status later in infancy. This research is discussed in the context of current clamping practices, which tend towards early cord clamping in most settings, as well as the high levels of anemia present in young infants in many countries worldwide. © 2011 International Life Sciences Institute.

  10. Spatially Resolved Spectra of 3C Galaxy Nuclei

    NASA Technical Reports Server (NTRS)

    Hutchings, J. B.; Baum, S. A.; Weistrop, D.; Nelson, C.; Kaiser, M. E.; Gelderman, R. F.

    1998-01-01

    We present and discuss visible-wavelength long-slit spectra of four low-redshift 3C galaxies obtained with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope (HST). The slit was aligned with near-nuclear jet-like structure seen in HST images of the galaxies, to give unprecedented spatial resolution of their inner regions. In 3C 135 and 3C 171, the spectra reveal clumpy emission-line structures that indicate outward motions of a few hundred kilometers per second within a centrally illuminated and ionized biconical region. There may also be some low-ionization, high-velocity material associated with 3C 135. In 3C 264 and 3C 78, the jets have blue featureless spectra consistent with their proposed synchrotron origin. There is weak associated line emission in the innermost part of the jets with mild outflow velocity. These jets are bright and highly collimated only within a circumnuclear region of lower galaxy luminosity, which is not dusty. We discuss the origins of these central regions and their connection with relativistic jets.

  11. A High-Efficiency Diode-Clamped Linear Amplifier

    NASA Astrophysics Data System (ADS)

    Fujita, Hideaki

    This paper proposes a new power converter without any switching operation, which works as a linear amplifier. The main circuit of the proposed converter consists of series-connected MOSFETs, series-multi dc power supplies and clamping diodes. The circuit configuration is similar to a diode-clamped multi-level inverter, except for using complementary power devices, which are n- and p-channel MOSFETs. One of the series-connected MOSFETs operates in an active state just like a linear amplifier, while the other MOSFETs operate in on or off states like an inverter circuit. As a result, the proposed converter achieves an acceptable efficiency as high as 90% without any ripples nor harmonics caused by switching operation. Experimental results demonstrate that the proposed converter has capability of driving a 2.2-kW three-phase induction motor.

  12. Patch-clamp experiments under micro-gravity.

    PubMed

    Meissner, Klaus; Hanke, Wolfgang

    2002-07-01

    For human based space research it is of high importance to understand the influence of gravity on the properties of single ion channels in biological membranes, as these are involved in about all biological processes. The patch clamp technique is the best established method to investigate electrophysiological properties of single ion channels in detail. Consequently, a patch clamp set-up was designed for the drop tower in Bremen, Germany. Using this set-up among others, successfully leech neurons have been patched under micro-gravity, delivering data about ion channel behaviour, which were compared to results from bilayer experiments in the drop tower and to results from lab controls under 1 g and under higher gravity.

  13. Active energy recovery clamping circuit to improve the performance of power converters

    DOEpatents

    Whitaker, Bret; Barkley, Adam

    2017-05-09

    A regenerative clamping circuit for a power converter using clamping diodes to transfer charge to a clamping capacitor and a regenerative converter to transfer charge out of the clamping capacitor back to the power supply input connection. The regenerative converter uses a switch connected to the midpoint of a series connected inductor and capacitor. The ends of the inductor and capacitor series are connected across the terminals of the power supply to be in parallel with the power supply.

  14. Corrosion response of downhole steam generator assembly and instrumentation and supply line tubings at Long Beach field test

    SciTech Connect

    Weirick, L.J.

    1983-07-01

    Three families of metals were used to make the non-combustor components for Sandia's downhole steam generator assembly and supply and instrumentation lines. These three families were: first, plain carbon steel (API Grade J 55); second, austenitic stainless steels (316 and 310); and third, a nickel-base superalloy (Inconel 600). The metals in all three of these families were found to be deficient in their corrosion response. J 55 exhibited minimal to severe general corrosion (rusting). The austenitic stainless steels pitted and cracked. Inconel 600 showed both severe pitting and some intergranular attack. For the most part, these materials were found to be unsuitable for extended life in a downhole steam generator. It is recommended that Inconel 625 be used in future systems where a moderate strength material is specified and Inconel 718 be considered where a high strength material is necessary. 11 references, 45 figures, 5 tables.

  15. Cleaning patch-clamp pipettes for immediate reuse

    PubMed Central

    Kolb, I.; Stoy, W. A.; Rousseau, E. B.; Moody, O. A.; Jenkins, A.; Forest, C. R.

    2016-01-01

    Patch-clamp recording has enabled single-cell electrical, morphological and genetic studies at unparalleled resolution. Yet it remains a laborious and low-throughput technique, making it largely impractical for large-scale measurements such as cell type and connectivity characterization of neurons in the brain. Specifically, the technique is critically limited by the ubiquitous practice of manually replacing patch-clamp pipettes after each recording. To circumvent this limitation, we developed a simple, fast, and automated method for cleaning glass pipette electrodes that enables their reuse within one minute. By immersing pipette tips into Alconox, a commercially-available detergent, followed by rinsing, we were able to reuse pipettes 10 times with no degradation in signal fidelity, in experimental preparations ranging from human embryonic kidney cells to neurons in culture, slices, and in vivo. Undetectable trace amounts of Alconox remaining in the pipette after cleaning did not affect ion channel pharmacology. We demonstrate the utility of pipette cleaning by developing the first robot to perform sequential patch-clamp recordings in cell culture and in vivo without a human operator. PMID:27725751

  16. A mathematical model of the euglycemic hyperinsulinemic clamp

    PubMed Central

    Picchini, Umberto; De Gaetano, Andrea; Panunzi, Simona; Ditlevsen, Susanne; Mingrone, Geltrude

    2005-01-01

    Background The Euglycemic Hyperinsulinemic Clamp (EHC) is the most widely used experimental procedure for the determination of insulin sensitivity, and in its usual form the patient is followed under insulinization for two hours. In the present study, sixteen subjects with BMI between 18.5 and 63.6 kg/m2 were studied by long-duration (five hours) EHC. Results From the results of this series and from similar reports in the literature it is clear that, in obese subjects, glucose uptake rates continue to increase if the clamp procedure is prolonged beyond the customary 2 hours. A mathematical model of the EHC, incorporating delays, was fitted to the recorded data, and the insulin resistance behaviour of obese subjects was assessed analytically. Obese subjects had significantly less effective suppression of hepatic glucose output and higher pancreatic insulin secretion than lean subjects. Tissue insulin resistance appeared to be higher in the obese group, but this difference did not reach statistical significance. Conclusion The use of a mathematical model allows a greater amount of information to be recovered from clamp data, making it easier to understand the components of insulin resistance in obese vs. normal subjects. PMID:16269082

  17. Cleaning patch-clamp pipettes for immediate reuse.

    PubMed

    Kolb, I; Stoy, W A; Rousseau, E B; Moody, O A; Jenkins, A; Forest, C R

    2016-10-11

    Patch-clamp recording has enabled single-cell electrical, morphological and genetic studies at unparalleled resolution. Yet it remains a laborious and low-throughput technique, making it largely impractical for large-scale measurements such as cell type and connectivity characterization of neurons in the brain. Specifically, the technique is critically limited by the ubiquitous practice of manually replacing patch-clamp pipettes after each recording. To circumvent this limitation, we developed a simple, fast, and automated method for cleaning glass pipette electrodes that enables their reuse within one minute. By immersing pipette tips into Alconox, a commercially-available detergent, followed by rinsing, we were able to reuse pipettes 10 times with no degradation in signal fidelity, in experimental preparations ranging from human embryonic kidney cells to neurons in culture, slices, and in vivo. Undetectable trace amounts of Alconox remaining in the pipette after cleaning did not affect ion channel pharmacology. We demonstrate the utility of pipette cleaning by developing the first robot to perform sequential patch-clamp recordings in cell culture and in vivo without a human operator.

  18. Force-clamp laser trapping of rapidly interacting molecules

    NASA Astrophysics Data System (ADS)

    Capitanio, Marco; Monico, Carina; Vanzi, Francesco; Pavone, Francesco S.

    2013-06-01

    Forces play a fundamental role in a wide array of biological processes, regulating enzymatic activity, kinetics of molecular bonds, and molecular motors mechanics. Single molecule force spectroscopy techniques have enabled the investigation of such processes, but they are inadequate to probe short-lived (millisecond and sub-millisecond) molecular complexes. We developed an ultrafast force-clamp spectroscopy technique that uses a dual trap configuration to apply constant loads to a single intermittently interacting biological polymer and a binding protein. Our system displays a delay of only ˜10 μs between formation of the molecular bond and application of the force and is capable of detecting interactions as short as 100 μs. The force-clamp configuration in which our assay operates allows direct measurements of load-dependence of lifetimes of single molecular bonds. Moreover, conformational changes of single proteins and molecular motors can be recorded with sub-nanometer accuracy and few tens of microseconds of temporal resolution. We demonstrate our technique on molecular motors, using myosin II from fast skeletal muscle and on protein-DNA interaction, specifically on Lactose repressor (LacI). The apparatus is stabilized to less than 1 nm with both passive and active stabilization, allowing resolving specific binding regions along the actin filament and DNA molecule. Our technique extends single-molecule force-clamp spectroscopy to molecular complexes that have been inaccessible up to now, opening new perspectives for the investigation of the effects of forces on biological processes.

  19. DNA Sliding Clamps: Just the Right Twist to Load onto DNA

    SciTech Connect

    Barsky, D; Venclovas, C

    2005-10-24

    Two recent papers illuminate a long sought step in DNA sliding clamp loading. One paper reveals the structure of the PCNA clamp wrapped around DNA--still open from being loaded--while a second paper discovers that the clamp may assist this process by forming a right-handed helix upon opening.

  20. Pressure controlled clamp using shape memory alloy for minimal vessel invasion in blood flow occlusion.

    PubMed

    Zhang, Ye; Kanetaka, Hiroyasu; Sano, Yuya; Kano, Mitsuhiro; Kudo, Tadaaki; Sato, Takumi; Shimizu, Yoshinaka

    2013-01-01

    Vessel damage after clamping may affect the success of surgical operations. A new pressure controlled clamp (SMA clamp) was designed using super elastic property of shape memory alloy (SMA) to realize atraumatic vessel occlusion. The ability and biological effect of the SMA clamp to control pressure was investigated in vivo. The loading-displacement curves of the SMA clamps (experimental group) and conventional clamp (control group) by occlusion of pig carotid arteries were evaluated using a clamping-pressure analyzing system. To investigate macroscopically and histologically the vessel damage of the SMA and conventional clamps, pig carotid arteries were stained with Evan's blue and its histological sections were stained with Elastica Massion after clamping for fifteen minutes. Constant value was shown in the loading-displacement curve of SMA clamp. In the control group, damaged area stained with Evan's blue in the vessel wall showed enlargement with the pressure increasing. Less areas in experimental groups are observed than that in the control group. Histological section in the experimental group showed no obvious except a slight compressive damage in the tunica intima. In the control group, vessel wall showed irreversible damages. This experiment indicated that the SMA clamp, which has a unique mechanical property, can be used without vessels damage. This pressure controlled clamp can be a selection in clinical apparatus to improve surgical safety.

  1. System to inject steam and produce oil from the same wellbore through downhole valve switching. Final report

    SciTech Connect

    Not Available

    1994-10-01

    Through direct contacts with many California Operators, the potential market for this technology and hardware was more closely defined. The largest market might be for re-entry into existing but shut-in wells, equipped with 7{double_prime}OD cemented casings, for which a suitable configuration was designed. For field-testing any prototype Downhole equipment, however, Operators and Service Companies prefer to start with a new well, for better control of the well characteristics. In the relatively shallow reservoirs where Steam injection is currently used with success, the additional drilling cost, in soft formations, is sufficiently small that this became the main design case. Substantial savings were obtained by reducing the number of Downhole valves from two to one and by replacing the twin hydraulically-controlled ball or flapper-type valves with a single sliding sleeve valve, operated by wireline. Laboratory tests conducted at UC-Berkeley confirmed the satisfactory operation of this type of valve with wet steam over extended periods. Low reservoir pressures dictated the use of artificial lift methods, with rod pumps considered the most economical. The availability of live steam downhole at all times is, however, a major advantage which led to the selection of a combined method of artificial lift: (1) steam-lift of the produced fluids up to the kick-off point of the medium curvature drainholes, (2) dumping of the produced fluids into a vertical separator/sump below the kick-off points, (3) vertical rod pumping of the liquid phases from the downhole separator/sump to the surface through a dedicated production tubing.

  2. Fine Structure in 3C 120 and 3C 84. Ph.D. Thesis - Maryland Univ., 24 Aug. 1976

    NASA Technical Reports Server (NTRS)

    Hutton, L. K.

    1976-01-01

    Seven epochs of very long baseline radio interferometric observations of the Seyfert galaxies 3C 120 and 3C 84, at 3.8-cm wave length using stations at Westford, Massachusetts, Goldstone, California, Green Bank, West Virginia, and Onsala, Sweden, have been analyzed for source structure. An algorithm for reconstructing the brightness distribution of a spatially confined source from fringe amplitude and so called closure phase data has been developed and successfully applied to artificially generated test data and to data on the above mentioned sources. Over the two year time period of observation, 3C 120 was observed to consist of a double source showing apparent super relativistic expansion and separation velocities. The total flux changes comprising one outburst can be attributed to one of these components. 3C 84 showed much slower changes, evidently involving flux density changes in individual stationary components rather than relative motion.

  3. Summary evaluation of Yucca Mountain surface transects with implications for downhole sampling. Yucca Mountain Site Characterization Project

    SciTech Connect

    Mckenna, S.A.; Rautman, C.A.

    1995-06-01

    The results of previously completed vertical outcrop sampling transacts are summarized with respect to planning downhole sampling. The summary includes statistical descriptions and descriptions of the spatial variability of the sampled parameters. Descriptions are made on each individual transect, each thermal/mechanical unit and each previously defined geohydrologic unit. Correlations between parameters indicate that saturated hydraulic conductivity is not globally correlated to porosity. The correlation between porosity and saturated hydraulic conductivity is both spatially and lithologically dependent. Currently, there are not enough saturated hydraulic conductivity and sorptivity data to define relationships between these properties and porosity on a unit by unit basis. Also, the Prow Pass member of the Crater Flat Tuff and stratigraphically lower units have gone essentially unsampled in these outcrop transacts. The vertical correlation length for hydrologic properties is not constant across the area of the transacts. The average sample spacing within the transacts ranges from 1.25 to 2.1 meters. It appears that, with the exception of the Topopah Spring member units, a comparable sample spacing will give adequate results in the downhole sampling campaign even with the nonstationarity of the vertical correlation. The properties within the thermal/mechanical units and geohydrologic units of the Topopah Spring member appear to have a spatial correlation range less than or equal to the current sample spacing within these units. For the downhole sampling, a sample spacing of less than 1.0 meters may be necessary within these units.

  4. RXTE, VLBA, Optical, and Radio Monitoring of the Quasars 3C 279, PKS 1510--089, and 3C 273

    NASA Technical Reports Server (NTRS)

    Marscher, A. P.; Jorstad, S. G.; Aller, M. F.; McHardy, I. M.; Balonek, T. J.

    2001-01-01

    We are continuing our combined RXTE X-ray, VLBA imaging (at 43 GHz), optical (several observatories), and radio (University of Michigan Radio Astronomy Observatory) monitoring of the quasars 3C 279 and PKS 1510-089, and have started similar monitoring of 3C 273. X-ray flares in 3C 279 and PKS 1510-089 are associated with ejections of superluminal components. In addition, there is a close connection between the optical and X-ray variability of 3C 279. There is a strong correlation between the 14.5 GHz and X-ray variability of PKS 1510-089 in 1997 and 1998 (with the radio leading the X-ray) that becomes weaker in subsequent years. X-ray fluctuations occur on a variety of timescales in 3C 273, with a major prolonged outburst in mid-2001. The lead author will discuss the correlations in terms of inverse Compton models for the X-ray emission coupled with synchrotron models for the lower-frequency radiation. Synchrotron self-Compton models can explain the "reverse" time lag in PKS 1510-089 is well as the variable correlation between the X-ray variations and those at lower frequencies in this object and in 3C 279.

  5. Imaging Fracking Zones by Microseismic Reverse Time Migration for Downhole Microseismic Monitoring

    NASA Astrophysics Data System (ADS)

    Lin, Y.; Zhang, H.

    2015-12-01

    Hydraulic fracturing is an engineering tool to create fractures in order to better recover oil and gas from low permeability reservoirs. Because microseismic events are generally associated with fracturing development, microseismic monitoring has been used to evaluate the fracking process. Microseismic monitoring generally relies on locating microseismic events to understand the spatial distribution of fractures. For the multi-stage fracturing treatment, fractures created in former stages are strong scatterers in the medium and can induce strong scattering waves on the waveforms for microseismic events induced during later stages. In this study, we propose to take advantage of microseismic scattering waves to image fracking zones by using seismic reverse time migration method. For downhole microseismic monitoring that involves installing a string of seismic sensors in a borehole near the injection well, the observation geometry is actually similar to the VSP (vertical seismic profile) system. For this reason, we adapt the VSP migration method for the common shot gather to the common event gather. Microseismic reverse-time migration method involves solving wave equation both forward and backward in time for each microseismic event. At current stage, the microseismic RTM is based on 2D acoustic wave equation (Zhang and Sun, 2008), solved by the finite-difference method with PML absorbing boundary condition applied to suppress the reflections of artificial boundaries. Additionally, we use local wavefield decomposition instead of cross-correlation imaging condition to suppress the imaging noise. For testing the method, we create a synthetic dataset for a downhole microseismic monitoring system with multiple fracking stages. It shows that microseismic migration using individual event is able to clearly reveal the fracture zone. The shorter distance between fractures and the microseismic event the clearer the migration image is. By summing migration images for many

  6. Enhanced Oil Recovery with Downhole Vibration Stimulation in Osage County, Oklahoma

    SciTech Connect

    J. Ford Brett; Robert V. Westermark

    2001-12-31

    This Technical Quarterly Report is for the reporting period September 30, 2001 to December 31, 2001. The report provides details of the work done on the project entitled ''Enhanced Oil Recovery with Downhole Vibration Stimulation in Osage County Oklahoma''. The project is divided into nine separate tasks. Several of the tasks are being worked on simultaneously, while other tasks are dependent on earlier tasks being completed. The vibration stimulation well was permitted as Well 111-W-27, section 8 T26N R6E Osage County Oklahoma. It was spud July 28, 2001 with Goober Drilling Rig No. 3. The well was drilled to 3090-feet cored, logged, cased and cemented. The Rig No.3 moved off August 6, 2001. Phillips Petroleum Co. has performed standard core analysis on the cores recovered from the test well. Standard porosity, permeability and saturation measurements have been conducted. Phillips has begun the sonic stimulation core tests. Calumet Oil Company, the operator of the NBU, has been to collecting both production and injection wells information to establish a baseline for the project in the pilot field test area since May 2001. The 7-inch Downhole Vibration Tool (DHVT) has been built and has been run in a shallow well for initial power source testing. This testing was done in a temporarily abandoned well, Wynona Waterflood Unit, Well No.20-12 operated by Calumet Oil Co both in October and December 2001. The data acquisition system, and rod rotating equipment performed as designed. However, the DHVT experienced two internal failures during vibration operations. The DHVT has been repaired with modifications to improve its functionality. A proposed technical paper abstract has been accepted by the SPE to be presented at the 2002 SPE/DOE Thirteenth Symposium on Improved Oil Recovery, in Tulsa OK, 13-17 April 2002. A one-day SPE sponsored short course which is planned to cover seismic stimulation efforts around the world, will be offered at the SPE/DOE Thirteenth Symposium on

  7. Three-dimensional site response at KiK-net downhole arrays

    USGS Publications Warehouse

    Thompson, Eric M.; Tanaka, Yasuo; Baise, Laurie G.; Kayen, Robert E.

    2010-01-01

    Ground motions at two Kiban-Kyoshin Network (KiK-net) strong motion downhole array sites in Hokkaido, Japan (TKCH08 in Taiki and TKCH05 in Honbetsu) illustrate the importance of three-dimensional (3D) site effects. These sites recorded the M8.0 2003 Tokachi-Oki earthquake, with recorded accelerations above 0.4 g at both sites as well as numerous ground motions from smaller events. Weak ground motions indicate that site TKCH08 is well modeled with the assumption of plane SH waves traveling through a 1D medium (SH1D), while TKCH05 is characteristic of a poor fit to the SH1D theoretical response. We hypothesized that the misfit at TKCH05results from the heterogeneity of the subsurface. To test this hypothesis, we measured four S-wave velocity profiles in the vicinity (< 300 m) of each site with the spectral analysis of surface waves (SASW) method. This KiK-net site pair is ideal for assessing the relative importance of 3D site effects and nonlinear site effects. The linear ground motions at TKCH05 isolate the 3D site effects, as we hypothesized from the linear ground motions and confirmed with our subsequent SASW surveys. The Tokachi-Oki time history at TKCH08 isolates the effects of nonlinearity from spatial heterogeneity because the 3D effects are negligible. The Tokachi-Oki time history at TKCH05 includes both nonlinear and 3D site effects. Comparisons of the accuracy of the SH1D model predictions of these surface time histories from the downhole time histories indicates that the 3D site effects are at least as important as nonlinear effects in this case. The errors associated with the assumption of a 1D medium and 1D wave propagation will be carried into a nonlinear analysis that relies on these same assumptions. Thus, the presence of 3D effects should be ruled out prior to a 1D nonlinear analysis. The SH1D residuals show that 3D effects can be mistaken for nonlinear effects.

  8. Planar silicon patch-clamp electrodes integrated with polydimethylsiloxane microfluidics

    NASA Astrophysics Data System (ADS)

    Nagarah, John Michael

    The patch-clamp technique allows one to probe single ion channels and macroscopic ion channel activity in their native environment and resolve their activity as their physical and chemical surroundings are varied. The traditional method of patch-clamping cells involves bringing a clean, flame-polished glass pipette tip with a 1-2 mum diameter pore into contact with a cell membrane to form a high electrical resistance seal. This technique is the gold standard for cellular electrophysiology investigations because it allows the observation of single ion channel protein dynamics as well as activity from an ensemble ion channels from a single cell. Furthermore, any drug approved by federal drug agencies must be screened against particular ion channels with the patch-clamp technique. However, this technique by its nature is serial, time consuming, difficult when exchanging pipette solutions, and difficult to integrate with other technologies. These reasons have prompted several investigators to explore alternative approaches to traditional pipette patch-clamping to increase the throughput of measurements. Herein, I describe the development of a silicon-wafer based device platform that enables the measurement of ion channel activities. The electrical nature of the cell/wafer seal is characterized for several pore design variations. The majority of gigaohm seals obtained falls in the range of 10-20GO. The cell-attached and whole cell configurations are demonstrated. Whole cell ion channel activity originating from various cell fines is consistent with the more traditional micropipette patch-clamp recordings. The silicon fabrication methods developed, although novel, utilize established semiconductor technologies, making them amenable to batch fabrication techniques. I integrate these silicon devices with PDMS microfluidics with monolithic valves, allowing ultra-fast solution exchange as low as tens of milliseconds for the extracellular solution. Furthermore, I developed a

  9. Effect of Delayed Cord Clamping on Systemic Blood Flow: A Randomized Controlled Trial.

    PubMed

    Popat, Himanshu; Robledo, Kristy P; Sebastian, Lucille; Evans, Nicholas; Gill, Andrew; Kluckow, Martin; Sinhal, Sanjay; de Waal, Koert; Tarnow-Mordi, William; Osborn, David

    2016-11-01

    To determine whether delayed cord clamping improves systemic blood flow compared with immediate cord clamping in very preterm infants in the first 24 hours. Women delivering at <30 weeks' gestation at 5 tertiary centers were randomized to receive immediate cord clamping (<10 seconds) or delayed cord clamping (≥60 seconds). Echocardiography and cardiorespiratory data were collected at 3, 9, and 24 hours after birth. The primary outcome was mean lowest superior vena cava (SVC) flow. Of 266 infants enrolled, 133 were randomized to immediate cord clamping and 133 to delayed cord clamping. The 2 groups were similar at baseline, including mean gestation (immediate cord clamping 28 weeks vs delayed cord clamping 28 weeks) and birth weight (immediate cord clamping 1003 g vs delayed cord clamping 1044 g). There was no significant difference between groups in the primary outcome of mean lowest SVC flow (immediate cord clamping 71.4 mL/kg/min [SD 28.1] vs delayed cord clamping 70.2 mL/kg/min [SD 26.9]; P = .7). For secondary outcomes, hemoglobin increased by 0.9 g/dL at 6 hours in the group with delayed cord clamping (95% CI 3.9, 14.4; P = .0005, adjusted for baseline). The group with delayed cord clamping had lower right ventricular output (-21.9 mL/kg/min, 95% CI -39.0, -4.7; P = .01). Rates of treated hypotension, ductus arteriosus size and shunt direction, and treatment of the ductus arteriosus were similar. Delayed cord clamping had no effect on systemic blood flow measured as mean lowest SVC flow in the first 24 hours in infants <30 weeks' gestation. Australia New Zealand Clinical Trials Registry: ACTRN12610000633088. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Extracellular potassium accumulation in voltage-clamped frog ventricular muscle.

    PubMed Central

    Cleemann, L; Morad, M

    1979-01-01

    1. Application of voltage clamp pulses (1--10 sec) to frog ventricular strips causes temporary changes in the extracellular K concentration. 2. The changes in the extracellular K concentration can be estimated from (a) slowly decaying post-clamp after-potentials, (b) changes in the action potential duration, and (c) measurements with a K-selective micro-electrode. 3. The depolarization of the resting potential and the shortening of the action potential are present in approximately the same proportions during voltage-clamp induced extracellular K accumulation and during perfusion with a K-ricn Ringer solution but small consistent differences are noticed. 4. The measurements of the after-potential, the action potential shortening, and the K-electrode response were analysed as indicators of extracellular K+ activity and it was concluded that the after-potential provides the most convenient and reliable estimate of the absolute magnitude of the voltage-clamp induced extracellular K accumulation. 5. The depolarizing after-potentials decay more slowly than the hyperpolarizing after-potentials but it is found that this reflects the selectivity of the membrane to K+ concentrations as predicted by the Nernst or the Goldman equations. 6. Analysis of the redistribution of accumulated K+ from the decay of the after-potential suggests that the major part of the redistribution process can be described by a single time constant (2--4 sec). A much longer time constant is required for a smaller component of the 'tail' in order to bring [K]o to the normal resting state. 7. N-shaped relations similar to the 'steady state' current-voltage relation are obtained when the post-clamp after-potential, the action potential shortening, and the K-electrode response are plotted versus the clamped membrane potential. The maxima of these curves are located around -40 mV and the minima around -20 mV. 8. In spite of a significant outward membrane current (1--1.5 microamperemeter) in the minimum

  11. Peptide aldehyde inhibitors of hepatitis A virus 3C proteinase.

    PubMed

    Malcolm, B A; Lowe, C; Shechosky, S; McKay, R T; Yang, C C; Shah, V J; Simon, R J; Vederas, J C; Santi, D V

    1995-06-27

    Picornaviral 3C proteinases are a group of closely related thiol proteinases responsible for processing of the viral polyprotein into its component proteins. These proteinases adopt a chymotrypsin-like fold [Allaire et al. (1994) Nature 369, 72-77; Matthews et al. (1994) Cell 77, 761-771] and a display an active-site configuration like those of the serine proteinases. Peptide-aldehydes based on the preferred peptide substrates for hepatitis A virus (HAV) 3C proteinase were synthesized by reduction of a thioester precursor. Acetyl-Leu-Ala-Ala-(N,N'-dimethylglutaminal) was found to be a reversible, slow-binding inhibitor for HAV 3C with a Ki* of (4.2 +/- 0.8) x 10(-8) M. This inhibitor showed 50-fold less activity against the highly homologous human rhinovirus (strain 14) 3C proteinase, whose peptide substrate specificity is slightly different, suggesting a high degree of selectivity. NMR spectrometry of the adduct of the 13C-labeled inhibitor with the HAV-3C proteinase indicate that a thiohemiacetal is formed between the enzyme and the aldehyde carbon as previously noted for peptide-aldehyde inhibitors of papain [Lewis & Wolfenden (1977) Biochemistry 16,4890-4894; Gamcsik et al. (1983) J. Am. Chem. Soc. 105, 6324-6325]. The adduct can also be observed by electrospray mass spectrometry.

  12. The nature of the galaxy around 3C 48

    SciTech Connect

    Stockton, A.; Ridgway, S.E. )

    1991-08-01

    New images are presented of the QSO 3C 48 in line-free bands centered at 0.58, 0.77, and 2.1 microns and in a narrowband centered on the forbidden O III5007 line. Careful profile subtraction of the continuum images shows an apparent luminosity peak centered about 1 arcsec northeast of the QSO position, which is tentatively identified as the nucleus of a galaxy in the process of merging with the host galaxy of 3C 48. The arclike structure extending to the northwest appears to be a tidal tail associated with the companion galaxy. While the confirmation that the host galaxy of 3C 48 is interacting is consistent with the inference that 3C 48 and similar objects are transitional between ultraluminous starburst galaxies and classical QSOs, an apparent correlation between far-infrared spectral properties and optical morphology suggests that the supposed 'transitional' characteristics may persist for at least 10 to the 8th yr, so the place of objects like 3C 48 in an evolutionary scenario depends on the typical lifetime of QSO activity. 38 refs.

  13. Photosynthesis in C3-C4 intermediate Moricandia species.

    PubMed

    Schlüter, Urte; Bräutigam, Andrea; Gowik, Udo; Melzer, Michael; Christin, Pascal-Antoine; Kurz, Samantha; Mettler-Altmann, Tabea; Weber, Andreas Pm

    2017-01-01

    Evolution of C4 photosynthesis is not distributed evenly in the plant kingdom. Particularly interesting is the situation in the Brassicaceae, because the family contains no C4 species, but several C3-C4 intermediates, mainly in the genus Moricandia Investigation of leaf anatomy, gas exchange parameters, the metabolome, and the transcriptome of two C3-C4 intermediate Moricandia species, M. arvensis and M. suffruticosa, and their close C3 relative M. moricandioides enabled us to unravel the specific C3-C4 characteristics in these Moricandia lines. Reduced CO2 compensation points in these lines were accompanied by anatomical adjustments, such as centripetal concentration of organelles in the bundle sheath, and metabolic adjustments, such as the balancing of C and N metabolism between mesophyll and bundle sheath cells by multiple pathways. Evolution from C3 to C3-C4 intermediacy was probably facilitated first by loss of one copy of the glycine decarboxylase P-protein, followed by dominant activity of a bundle sheath-specific element in its promoter. In contrast to recent models, installation of the C3-C4 pathway was not accompanied by enhanced activity of the C4 cycle. Our results indicate that metabolic limitations connected to N metabolism or anatomical limitations connected to vein density could have constrained evolution of C4 in Moricandia. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  14. Cell-attached voltage-clamp and current-clamp recording and stimulation techniques in brain slices.

    PubMed

    Perkins, Katherine L

    2006-06-30

    Cell-attached recording provides a way to record the activity of - and to stimulate - neurons in brain slices without rupturing the cell membrane. This review uses theory and experimental data to address the proper application of this technique and the correct interpretation of the data. Voltage-clamp mode is best-suited for recording cell firing activity, and current-clamp mode is best-suited for recording resting membrane potential and synaptic potentials. The magnitude of the seal resistance determines what types of experiments can be accomplished with a cell-attached recording: a loose seal is adequate for recording action potential currents, and a tight seal is required for evoking action potentials in the attached cell and for recording resting and synaptic potentials. When recording action potential currents, if the researcher does not want to change the firing activity of the cell, then it is important that no current passes from the amplifier through the patch resistance. In order to accomplish this condition, the recording pipette should be held at the potential that gives a holding current of 0. An advantage of cell-attached current-clamp over whole-cell recording is that it accurately depicts whether a synaptic potential is hyperpolarizing or depolarizing without the risk of changing its polarity.

  15. A Sema3C Mutant Resistant to Cleavage by Furin (FR-Sema3C) Inhibits Choroidal Neovascularization

    PubMed Central

    Toledano, Shira; Lu, Huayi; Palacio, Agustina; Ziv, Keren; Kessler, Ofra; Schaal, Shlomit; Neufeld, Gera; Barak, Yoreh

    2016-01-01

    In age-related macular degeneration (AMD), abnormal sub retinal choroidal neovascularization (CNV) is a major cause of blindness. FR-sema3C is a point mutated form of semaphorin-3C that is resistant to cleavage by furin like pro-protein convertases (FPPC). We have found in previous work that FR-sema3C functions as an anti-angiogenic factor. In this study we investigated the possible use of FR-sema3C as an inhibitor of CNV. FR-sema3C inhibits VEGF as well as PDGF-BB signal transduction in endothelial cells and to less extent bFGF induced signal transduction using a mechanism that does not depend upon the binding of VEGF like the drugs that are currently the mainstay treatment for AMD. CNV was induced in eyes of C57 black mice by laser photocoagulation. Intravitreal injection of FR-Sema3C or aflibercept (VEGF-trap) was then used to inhibit CNV formation. Invading choroidal vessels were visualized a week later by injection of FITC-dextran into the circulation, followed by the measurement of the area of the invading blood vessels. Injection of 0.1 μg FR-Sema3C inhibited CNV by 55% (P<0.01) and was as effective as 5 μg aflibercept. FR-sema3C did not display any adverse effects on retinal function following its injection into eyes of healthy mice as assessed by optokinetic reflex (OKR) and Electro-retinogram (ERG) criteria. Furthermore, FR-sema3C did not induce apoptosis in the retina as determined by TUNEL nor was there any discernable structural damage to the retina as assessed by several immuno-histochemical criteria. Our results suggest that FR-sema3C could perhaps be used for the treatment of AMD, and that it may perhaps be of benefit to patients that do not respond well to current treatments relying on VEGF sequestering agents. PMID:28036336

  16. Timing of umbilical cord clamping: new thoughts on an old discussion.

    PubMed

    Arca, Gemma; Botet, Francesc; Palacio, Montse; Carbonell-Estrany, Xavier

    2010-11-01

    The optimal time to clamp the umbilical cord in preterm and full-term neonates after birth continues to be a matter of debate. A review of randomised controlled trials comparing the effects of early versus late cord clamping on maternal and infant outcomes was performed to assess data in favor of immediate or delayed clamping. Although there is no conclusive evidence, delayed cord clamping seems to be beneficial in preterm and full-term neonates without compromising the initial postpartum adaptation phase or affecting the mother in the short term. However, further randomised clinical studies are needed to confirm the benefits of delayed cord clamping.

  17. Graphene/3C-SiC Hybrid Nanolaminate.

    PubMed

    Zhuang, Hao; Yang, Bing; Heuser, Steffen; Huang, Nan; Fu, Haiyuan; Jiang, Xin

    2015-12-30

    In this work, we demonstrate a one-step approach to create graphene/3C-SiC nanolaminate structure using microwave plasma chemical vapor deposition technique. Layer-by-layer arrangement of thin 3C-SiC layers and graphene sheets is obtained with the thicknesses of the individual 3C-SiC layers and graphene sheets being 5-10 nm and 2-5 nm, respectively. An intimate contact between 3C-SiC and the graphene sheets is achieved and the nanolaminate film shows a high room temperature conductivity of 96.1 S/cm. A dedicated structural analysis of the nanolaminates by means of high-resolution transmission electron microscopy (HRTEM) reveals that the growth of the nanolaminates follows an iterative process: preferential graphene nucleation around the planar defects at the central region of the SiC layer, leading to the "splitting" of the SiC layer; and the thickening of the SiC layer after being "split". A growth mechanism based on both kinetics and thermodynamics is proposed. Following the proposed mechanism, it is possible to control the layer thickness of the graphene/3C-SiC hybrid nanolaminate by manipulating the carbon concentration in the gas phase, which is further experimentally verified. The high electrical conductivity, large surface area porous structure, feasible integration on different substrates (metal, Mo; semiconductor, Si and 2H-SiC; insulator, diamond) of the graphene/3C-SiC hybrid nanolaminate as well as other unprecedented advantages of the nanolaminate structure make it very promising for applications in mechanical, energy, and sensor-related areas.

  18. Clamping stiffness and its influence on load distribution between paired internal spinal fixation devices.

    PubMed

    Rohlmann, A; Calisse, J; Bergmann, G; Radvan, J; Mayer, H M

    1996-06-01

    The load distribution between two internal spinal fixation devices depends, besides other factors, on their stiffness. The stiffness ranges were determined experimentally for the clamps of the AO internal fixator with lateral nut and with posterior nut as well as for the clamps of the SOCON fixator. The stiffness of eight devices each differed by a factor of 3.1 for the clamp with lateral nut, by a factor of 1.5 for the clamp with posterior nut, and by a factor of 1.4 for the clamp of the SOCON fixator. For the AO clamp with lateral nut, the influence of the nut-tightening torque on the stiffness was determined. Using instrumented internal spinal fixation devices mounted to plastic vertebrae and simulating a corpectomy, the load distribution between the implants was measured for different tightening torques. It could be shown that, for the AO internal fixator whose clamps have a lateral nut, a nut-tightening torque > 5 Nm has only a negligible influence on load-sharing between the implants. Tooth damage occurs when the teeth of the clamp body and clamping jaw of the clamp with lateral nut do not gear together exactly, which leads to changes in the clamping stiffness and load-sharing between the two implants.

  19. Downhole steam generator with improved preheating/cooling features. [Patent application

    DOEpatents

    Donaldson, A.B.; Hoke, D.E.; Mulac, A.J.

    1980-10-10

    An apparatus is described for downhole steam generation employing dual-stage preheaters for liquid fuel and for the water. A first heat exchange jacket for the fuel surrounds the fuel/oxidant mixing section of the combustor assembly downstream of the fuel nozzle and contacts the top of the combustor unit of the combustor assembly, thereby receiving heat directly from the combustion of the fuel/oxidant. A second stage heat exchange jacket surrounds an upper portion of the oxidant supply line adjacent the fuel nozzle receiving further heat from the compression heat which results from pressurization of the oxidant. The combustor unit includes an inner combustor sleeve whose inner wall defines the combustion zone. The inner combustor sleeve is surrounded by two concentric water channels, one defined by the space between the inner combustor sleeve and an intermediate sleeve, and the second defined by the space between the intermediate sleeve and an outer cylindrical housing. The channels are connected by an annular passage adjacent the top of the combustor assembly and the countercurrent nature of the water flow provides efficient cooling of the inner combustor sleeve. An annular water ejector with a plurality of nozzles is provided to direct water downwardly into the combustor unit at the boundary of the combustion zone and along the lower section of the intermediate sleeve.

  20. Direct-fired downhole steam generator: from design to field test

    SciTech Connect

    Schirmer, R.M.; Eson, R.L.

    1982-01-01

    A direct-fired downhole steam generator (DFDSG) has been developed which shows considerable promise for production of heavy oil. Generation of steam by surface boilers is inefficient because of heat losses, and air pollution curtails crude production. The technology of DFDSG is very attractive because it deals with both of these problems directly, and there are additional benefits. By carrying out the combustion process at high pressure, and then adding water, a mixture of carbon dioxide, nitrogen, and steam is charged directly into the heavy oil reservoir. This eliminates the need for expensive, and inefficient, stack scrubbers to remove sulfur dioxide, as well as sophisticated NO/sub x/ control techniques. The carbon dioxide created during the fuel burning process is absorbed by the heavy oil and increases its mobility without expending additional energy. Even the nitrogen contributes a high-velocity drag which increases both crude production rate and efficiency. DFDSG offers the potential for placing into the production zone, regardless of its depth, any quality effluent desired, from wet to superheated steam.

  1. On using surface-source downhole-receiver logging to determine seismic slownesses

    USGS Publications Warehouse

    Boore, D.M.; Thompson, E.M.

    2007-01-01

    We present a method to solve for slowness models from surface-source downhole-receiver seismic travel-times. The method estimates the slownesses in a single inversion of the travel-times from all receiver depths and accounts for refractions at layer boundaries. The number and location of layer interfaces in the model can be selected based on lithologic changes or linear trends in the travel-time data. The interfaces based on linear trends in the data can be picked manually or by an automated algorithm. We illustrate the method with example sites for which geologic descriptions of the subsurface materials and independent slowness measurements are available. At each site we present slowness models that result from different interpretations of the data. The examples were carefully selected to address the reliability of interface-selection and the ability of the inversion to identify thin layers, large slowness contrasts, and slowness gradients. Additionally, we compare the models in terms of ground-motion amplification. These plots illustrate the sensitivity of site amplifications to the uncertainties in the slowness model. We show that one-dimensional site amplifications are insensitive to thin layers in the slowness models; although slowness is variable over short ranges of depth, this variability has little affect on ground-motion amplification at frequencies up to 5 Hz.

  2. Tracer dye transport from a well fitted with a downhole heat exchanger, Klamath Falls, Oregon

    SciTech Connect

    Dunstall, M.G.

    1990-02-01

    Low or medium temperature geothermal resources are often used for space and domestic hot water heating. If the resource is located at reasonably shallow depths and adjacent to a major population centre large amounts of relatively cheap, clean heat can be provided. Geothermal fluid is often brought to the surface, either under natural artesian pressure or by pumping, to be used in surface heat exchangers (SHEs). This method generally requires a second well for disposal of the cooled fluid and a substantial capital outlay for pumps and heat exchangers. Large amounts of heat can be extracted from just one or two wells using surface heat exchangers and the method can prove very cost effective in areas with a high density of energy intensive users. For smaller heat loads surface heat exchangers can become expensive and in many instances a downhole heat exchanger (DHE) installed directly in the well bore is capable of supplying cheap heat to a smaller number of users. This report first describes the methods used to carry out the series of dye tests, from well selection to injection of the dye samples. It then discusses the results of these tests in terms of how much dye was recovered, where it was recovered from and how long it took to arrive. The results of the concurrent temperature monitoring work and DHE heat output performance are also presented. Some recommendations are made for any future testing. 13 refs., 42 figs.

  3. Methods and computer executable instructions for marking a downhole elongate line and detecting same

    DOEpatents

    Watkins, Arthur D.

    2003-05-13

    Methods and computer executable instructions are provided for making an elongate line (22) with a plurality of marks (30) and detecting those marks (30) to determine a distance of the elongate line (22) in a downhole or a physical integrity thereof. In a preferred embodiment, each mark comprises a plurality of particles (44) having a substantially permanent magnetizing capability adhered to an exterior surface of the elongate line (22) at preselected intervals with an epoxy paint. The particles (44) are arranged at each interval as a plurality of bands (40). Thereafter, the particles are oriented into a magnetic signature for that interval by magnetizing the particles to create a magnetic field substantially normal to the exterior surface. This facilitates detection by a Hall effect probe. The magnetic signatures are stored in a computing configuration and, once a mark is detected, a correlation is made to a unique position on the elongate line by comparison with the stored magnetic signatures. Preferred particles include samarium-cobalt and neodymium-iron-boride.

  4. System to inject steam and product oil from the same wellbore through downhole valve switching

    SciTech Connect

    Gondouin, M.

    1993-06-11

    The detailed design of a sliding sleeve valve operated by wireline has been completed. This Downhole Valve is obtained by modifications of two 2 7/8 in. commercial wireline-retrievable sleeve assemblies,which will be used to connect one of the upper branches of the patented Dual Whipstock to the 2 3/8 in. steam tubing,through a thermal expansion joint. Detailed engineering drawings and materials specifications have been completed. The design of the 30 ft-long joint comprising an H joint at the top a dual whipstock at the bottom and flow control devices for up to three drainholes equipped with 1.75 in. liners has been completed for a 7 in. cased well. This combination may be used in multi-layered reservoirs as well as in single layered reservoirs. It is also compatible with rod pump locations either above the kick-off pointsor near the base of the curved part of the drainhole liners. This design provides sufficient flexibility for most potential applications in the California market.

  5. System to inject steam and produce oil from the same wellbore through downhole valve switching

    SciTech Connect

    Not Available

    1992-01-01

    A market analysis for the Downhole Valves and associated hardware in California has shown that the main effort should be concentrated on the second case studied in the First Quarter Report, namely that of re-entry into a thermal well equipped with a 7 in. casing. An improved design,based on the use of a combination of a sliding sleeve valve with two plugs (all of them operated by wireline) is the most flexible and lowest cost configuration,for entering the largest market in California,that of existing vertical wells penetrating a relatively thin ([le] 40 ft) reservoir. At present oil prices at the California refineries, these wells, operated under cyclic steam injection are barely economic. They could become much more productive with the addition of a pair of small-diameter horizontal drainholes. A low-cost work-over program with all drilling and completion operations done through the 2 7/8 in. production tubing has been designed. Laboratory tests have confirmed the operability of the modified sliding sleeve valve with steam at temperatures ranging up to 500 F. Calculations have also determined the steam quality improvements resulting from using a low-cost Silicate foam insulation on the 2 3/8 in. steam tubing, with the 7 in. casing/tubings annulus filled with low-pressure gas.

  6. The Eocene-Oligocene Boundary in the Ross Sea (Antarctica), Based on Downhole Measurements

    NASA Astrophysics Data System (ADS)

    Buecker, C.; Jarrard, R.; Ehrmann, W.; Niessen, F.; Wonik, T.

    2001-12-01

    Drillholes CRP-1 to 3 of the Cape Roberts Project in the Northern McMurdo Sound (Ross Sea, Antarctica) targeted the western margin of the Victoria Land Basin to investigate Neogene to Paleogene climatic and tectonic history. Drilling on fast sea ice resulted in coring a stratigraphic succession with a composite thickness of 1500 m and an age range of 17 - 34 Ma. Well logging of CRP-3 has provided a complete and comprehensive dataset of in situ geophysical measurements down to 939 meters below sea floor (mbsf). By cluster analysis of the downhole logging data, it was possible to divide the borehole into three main sections. The upper section down to 230 mbsf is dominated by mudstones with clearly different physical properties from the mudstones occurring below this depth. Beneath 230 mbsf sandstones are dominating the lithology. Two types of sandstones could be characterized, with the lower sandstone being dominant below 630 mbsf down to a brecciated shear zone at 790 mbsf. These two types of sandstones, which are differentiated mainly by their magnetic properties, can be correlated to the detrital mode provenance analysis. The boundary marks the Eocene/Oligocene boundary. Comparison of these results with the seismic stratigraphy shows that the major change in sediment source from Victoria to Taylor Group is not seen by seismic sequence analysis. This finding will have consequences for the entire Ross Sea seismic stratigraphy.

  7. Downhole measurements and their use for stratigraphic correlations in the Ross Sea (Antarctica)

    NASA Astrophysics Data System (ADS)

    Bücker, C.; Jarrard, R.; Ehrmann, W.; Niessen, F.; Wonik, T.

    2003-04-01

    Drillholes CRP-1 to 3 of the Cape Roberts Project in the Northern McMurdo Sound (Ross Sea, Antarctica) targeted the western margin of the Victoria Land Basin to investigate Neogene to Paleogene climatic and tectonic history. Drilling on fast sea ice resulted in coring a stratigraphic succession with a composite thickness of 1500 m and an age range of 17 - 34 Ma. Well logging of CRP-3 has provided a complete and comprehensive dataset of in situ geophysical measurements down to 939 meters below sea floor (mbsf). By cluster analysis of the downhole logging data, it was possible to divide the borehole into three main sections. The upper section down to 230 mbsf is dominated by mudstones with clearly different physical properties from the mudstones occurring below this depth. Beneath 230 mbsf sandstones are dominating the lithology. Two types of sandstones could be characterized, with the lower sandstone being dominant below 630 mbsf down to a brecciated shear zone at 790 mbsf. These two types of sandstones, which are differentiated mainly by their magnetic properties, can be correlated to the detrital mode provenance analysis. The boundary marks the Eocene/Oligocene boundary. Comparison of these results with the seismic stratigraphy shows that the major change in sediment source from Victoria to Taylor Group is not seen by seismic sequence analysis. This finding will have consequences for the entire Ross Sea seismic stratigraphy.

  8. A hybrid fiber-optic sensing system for down-hole pressure and distributed temperature measurements

    NASA Astrophysics Data System (ADS)

    Chen, Ke; Zhou, Xinlei; Yang, Bokai; Peng, Wei; Yu, Qingxu

    2015-10-01

    A hybrid fiber-optic sensing technique, combining the extrinsic Fabry-Perot interferometer (EFPI) based pressure sensor with the incoherent optical frequency domain reflectometry (IOFDR) based distributed temperature sensor (DTS), is presented for down-hole measurements. By using a laser diode as the common light source, a highly integrated hybrid EFPI/DTS sensing system has been developed with a single fiber. With the injection current of the laser diode below lasing threshold, the broadband spontaneous emission light is used for EFPI based pressure sensing; while with the injection current above the threshold, the stimulated emission light is used for Raman based distributed temperature sensing. There is no overlap between the spectral range of the reflected light from the EFPI sensor and the spectral range of the Raman scattered light. Pressure and distributed temperature can thus be measured by using wavelength-division multiplexing (WDM) technology. Experimental results show that both the pressure and the distributed temperature are measured with little interference. Furthermore, the pressure measurement can be compensated by the measured temperature values.

  9. Subsurface sediment contamination during borehole drilling with an air-actuated down-hole hammer.

    PubMed

    Malard, Florian; Datry, Thibault; Gibert, Janine

    2005-10-01

    Drilling methods can severely alter physical, chemical, and biological properties of aquifers, thereby influencing the reliability of water samples collected from groundwater monitoring wells. Because of their fast drilling rate, air-actuated hammers are increasingly used for the installation of groundwater monitoring wells in unconsolidated sediments. However, oil entrained in the air stream to lubricate the hammer-actuating device can contaminate subsurface sediments. Concentrations of total hydrocarbons, heavy metals (Cu, Ni, Cr, Zn, Pb, and Cd), and nutrients (particulate organic carbon, nitrogen, and phosphorus) were measured in continuous sediment cores recovered during the completion of a 26-m deep borehole drilled with a down-hole hammer in glaciofluvial deposits. Total hydrocarbons, Cu, Ni, Cr and particulate organic carbon (POC) were all measured at concentrations far exceeding background levels in most sediment cores. Hydrocarbon concentration averaged 124 +/- 118 mg kg(-1) dry sediment (n = 78 samples) with peaks at depths of 8, 14, and 20 m below the soil surface (maximum concentration: 606 mg kg(-1)). The concentrations of hydrocarbons, Cu, Ni, Cr, and POC were positively correlated and exhibited a highly irregular vertical pattern, that probably reflected variations in air loss within glaciofluvial deposits during drilling. Because the penetration of contaminated air into the formation is unpreventable, the representativeness of groundwater samples collected may be questioned. It is concluded that air percussion drilling has strong limitations for well installation in groundwater quality monitoring surveys.

  10. Downhole oil/water separators offer lower costs and greater environmental protection

    SciTech Connect

    Veil, J. A.

    1999-11-02

    Produced water management can be a significant expense for oil and gas operators. This paper summarizes a study of the technical, economic, and regulatory feasibility of a relatively new technology, downhole oil/water separators (DOWS), to reduce the volume of water pumped to the surface. The study was funded by the US Department of Energy and conducted by Argonne National Laboratory, CH2M Hill, and the Nebraska Oil and Gas Conservation Commission. DOWS are devices that separate oil and gas from produced water at the bottom of the well and reinject some of the produced water into another formation or another horizon within the same formation, while the oil and gas are pumped to the surface. Since much of the produced water is not pumped to the surface, treated, and pumped from the surface back into a deep formation, the cost of handling produced water is greatly reduced. The oil production rate has increased for more than half of the DOWS installations to date.

  11. Casingless down-hole for sealing an ablation volume and obtaining a sample for analysis

    DOEpatents

    Noble, D.T.; Braymen, S.D.; Anderson, M.S.

    1996-10-01

    A casing-less down hole sampling system for acquiring a subsurface sample for analysis using an inductively coupled plasma system is disclosed. The system includes a probe which is pushed into the formation to be analyzed using a hydraulic ram system. The probe includes a detachable tip member which has a soil point and a barb, with the soil point aiding the penetration of the earth, and the barb causing the tip member to disengage from the probe and remain in the formation when the probe is pulled up. The probe is forced into the formation to be tested, and then pulled up slightly, to disengage the tip member and expose a column of the subsurface formation to be tested. An instrumentation tube mounted in the probe is then extended outward from the probe to longitudinally extend into the exposed column. A balloon seal mounted on the end of the instrumentation tube allows the bottom of the column to be sealed. A source of laser radiation is emitted from the instrumentation tube to ablate a sample from the exposed column. The instrumentation tube can be rotated in the probe to sweep the laser source across the surface of the exposed column. An aerosol transport system carries the ablated sample from the probe to the surface for testing in an inductively coupled plasma system. By testing at various levels in the down-hole as the probe is extracted from the soil, a profile of the subsurface formation may be obtained. 9 figs.

  12. Casingless down-hole for sealing an ablation volume and obtaining a sample for analysis

    DOEpatents

    Noble, Donald T.; Braymen, Steven D.; Anderson, Marvin S.

    1996-10-01

    A casing-less down hole sampling system for acquiring a subsurface sample for analysis using an inductively coupled plasma system is disclosed. The system includes a probe which is pushed into the formation to be analyzed using a hydraulic ram system. The probe includes a detachable tip member which has a soil point mad a barb, with the soil point aiding the penetration of the earth, and the barb causing the tip member to disengage from the probe and remain in the formation when the probe is pulled up. The probe is forced into the formation to be tested, and then pulled up slightly, to disengage the tip member and expose a column of the subsurface formation to be tested. An instrumentation tube mounted in the probe is then extended outward from the probe to longitudinally extend into the exposed column. A balloon seal mounted on the end of the instrumentation tube allows the bottom of the column to be sealed. A source of laser radiation is emitted from the instrumentation tube to ablate a sample from the exposed column. The instrumentation tube can be rotated in the probe to sweep the laser source across the surface of the exposed column. An aerosol transport system carries the ablated sample from the probe to the surface for testing in an inductively coupled plasma system. By testing at various levels in the down-hole as the probe is extracted from the soil, a profile of the subsurface formation may be obtained.

  13. Measurement of Downhole Steam Quality and Total Energy by Optical Methods

    SciTech Connect

    A. B. Donaldson; Graham R. Allen

    1998-04-01

    Initial steps have been taken to measure the mass of water in vapor and liquid phases downhole in a steam injection heavy oil recovery system. A suitable portion of the electromagnetic spectrum has been identified over which the presence of liquid water and vapor can be separated. This is in the near infrared and extends from ~900 nm to 1.8 µm region. A high pressure and high temperature cell has been constructed and tested for stagnant transmissions. Pitting of the optical ports due to the presence of high-pressure (8.5 MPA) and high temperature (300C) water has lead to a redesign of the optical ports, these modifications will be incorporated in the next quarter. The actual determination of the mass of water, either in liquid or vapor, has not been reliably determined, due in part to the pitting problems being addressed in the modification. However, qualitative data has been recorded clearly showing an increase in absorption with increasing number of absorbing molecules, i.e. mass of water.

  14. Surface and downhole shear wave seismic methods for thick soil site investigations

    USGS Publications Warehouse

    Hunter, J.A.; Benjumea, B.; Harris, J.B.; Miller, R.D.; Pullan, S.E.; Burns, R.A.; Good, R.L.

    2002-01-01

    Shear wave velocity-depth information is required for predicting the ground motion response to earthquakes in areas where significant soil cover exists over firm bedrock. Rather than estimating this critical parameter, it can be reliably measured using a suite of surface (non-invasive) and downhole (invasive) seismic methods. Shear wave velocities from surface measurements can be obtained using SH refraction techniques. Array lengths as large as 1000 m and depth of penetration to 250 m have been achieved in some areas. High resolution shear wave reflection techniques utilizing the common midpoint method can delineate the overburden-bedrock surface as well as reflecting boundaries within the overburden. Reflection data can also be used to obtain direct estimates of fundamental site periods from shear wave reflections without the requirement of measuring average shear wave velocity and total thickness of unconsolidated overburden above the bedrock surface. Accurate measurements of vertical shear wave velocities can be obtained using a seismic cone penetrometer in soft sediments, or with a well-locked geophone array in a borehole. Examples from thick soil sites in Canada demonstrate the type of shear wave velocity information that can be obtained with these geophysical techniques, and show how these data can be used to provide a first look at predicted ground motion response for thick soil sites. ?? 2002 Published by Elsevier Science Ltd.

  15. Subsurface geophysics of the Phlegrean Fields: New insights from downhole measurements

    NASA Astrophysics Data System (ADS)

    Rabaute, Alain; Yven, BéAtrice; Chelini, Walter; Zamora, Maria

    2003-03-01

    The volcanic complex of Phlegrean Fields, located northwest of Naples (Italy), has been the site of deep geothermal exploration in the 1980s. Several wells were drilled by an Agip-Enel joint venture, with downhole continuous physical properties acquired in each well. The main purpose of this study is to map and describe the spatial variations of the volcanic deposits, in terms of their nature, thickness and in situ physical properties. We apply fuzzy k means classification of the well-logging data available in the wells cored in the San Vito area. Fuzzy set theory provides an approach that quantitatively assigns individuals to physically continuous classes. The optimal number of classes is found by minimization of three mathematical functions, thus reducing subjectivity. The resulting classifications are found (1) to reflect the main lithologies in the San Vito plain, (2) to provide more detail on the geological stratigraphy, allowing a more precise volcanic history, and (3) to differentiate between transition zones and interbedded well-defined deposits. In addition to discriminating between lithologies that have different physical properties, this study gives information on the degree of homogeneity of each lithologic unit, and the range of variation for the measured properties. Finally, using the physical classification of the deposits, we are able to propose a detailed two-dimensional compressional acoustic velocity structure of the studied area.

  16. Fast and objective detection and analysis of structures in downhole images

    NASA Astrophysics Data System (ADS)

    Wedge, Daniel; Holden, Eun-Jung; Dentith, Mike; Spadaccini, Nick

    2017-09-01

    Downhole acoustic and optical televiewer images, and formation microimager (FMI) logs are important datasets for structural and geotechnical analyses for the mineral and petroleum industries. Within these data, dipping planar structures appear as sinusoids, often in incomplete form and in abundance. Their detection is a labour intensive and hence expensive task and as such is a significant bottleneck in data processing as companies may have hundreds of kilometres of logs to process each year. We present an image analysis system that harnesses the power of automated image analysis and provides an interactive user interface to support the analysis of televiewer images by users with different objectives. Our algorithm rapidly produces repeatable, objective results. We have embedded it in an interactive workflow to complement geologists' intuition and experience in interpreting data to improve efficiency and assist, rather than replace the geologist. The main contributions include a new image quality assessment technique for highlighting image areas most suited to automated structure detection and for detecting boundaries of geological zones, and a novel sinusoid detection algorithm for detecting and selecting sinusoids with given confidence levels. Further tools are provided to perform rapid analysis of and further detection of structures e.g. as limited to specific orientations.

  17. The optical object identified with 3C 455.

    NASA Technical Reports Server (NTRS)

    Arp, H. C.; Burbidge, E. M.; Strittmatter, P. A.; Mackay, C. D.

    1972-01-01

    It is shown that the optical object identified with 3C 455 is a quasi-stellar object with a redshift z = 0.543. The QSO is situated 23 sec northeast of the S0 galaxy NGC 7413, which has a redshift of 0.0332. It is pointed out that the discovery of the present object in a position so close to a galaxy is further evidence in favor of the existence of a physical association between 3C QSOs and bright galaxies.

  18. The Radio Spectral Index and Expansion of 3C 58

    DTIC Science & Technology

    2001-10-20

    it has often been described as morphologically similar to the Crab Nebula , the Crab being the prototype for this class. 3C 58 is at a similar distance...the Ðla- ments. This last situation does seem to obtain in the Crab Nebula , where strong circumstantial evidence points to the existence of such a...the surrounding material. We are then brought to a crucial di†erence between 3C 58 and the Crab Nebula : in the case of the Crab, the synchro- tron

  19. Viability of Stored Rabbit Erythrocytes Carrying Number C3c.

    DTIC Science & Technology

    1984-05-31

    A-A165 440 VIABILITY OF STORED RABBIT ERYTHROCYTES CARRYING NUBR V no C3C(U) MASSACHUSETTS UNIV MEDICAL SCHOOL MORCESTER UNCLRSSIFI 0 SZYMANSKI 31...Carrying No C3c 0 Annual and Final Report Irma 0. Szymanski, M.D. Ln CD May 31, 1984 I Supported by U.S. ARMY MEDICAL RESEARCH AND DEVELOPMENT COMMAND...Fort Detrick, Frederick, Maryland 21701-5012 Contract No. DAMD17-82-C-2150 .TICD ET University of Massachusetts Medical Center .EC, Worcester

  20. M. tuberculosis Sliding β-Clamp Does Not Interact Directly with the NAD+ -Dependent DNA Ligase

    PubMed Central

    Kukshal, Vandna; Khanam, Taran; Chopra, Deepti; Singh, Nidhi; Sanyal, Sabyasachi; Ramachandran, Ravishankar

    2012-01-01

    The sliding β-clamp, an important component of the DNA replication and repair machinery, is drawing increasing attention as a therapeutic target. We report the crystal structure of the M. tuberculosis β-clamp (Mtbβ-clamp) to 3.0 Å resolution. The protein crystallized in the space group C2221 with cell-dimensions a = 72.7, b = 234.9 & c = 125.1 Å respectively. Mtbβ-clamp is a dimer, and exhibits head-to-tail association similar to other bacterial clamps. Each monomer folds into three domains with similar structures respectively and associates with its dimeric partner through 6 salt-bridges and about 21 polar interactions. Affinity experiments involving a blunt DNA duplex, primed-DNA and nicked DNA respectively show that Mtbβ-clamp binds specifically to primed DNA about 1.8 times stronger compared to the other two substrates and with an apparent Kd of 300 nM. In bacteria like E. coli, the β-clamp is known to interact with subunits of the clamp loader, NAD+ -dependent DNA ligase (LigA) and other partners. We tested the interactions of the Mtbβ-clamp with MtbLigA and the γ-clamp loader subunit through radioactive gel shift assays, size exclusion chromatography, yeast-two hybrid experiments and also functionally. Intriguingly while Mtbβ-clamp interacts in vitro with the γ-clamp loader, it does not interact with MtbLigA unlike in bacteria like E. coli where it does. Modeling studies involving earlier peptide complexes reveal that the peptide-binding site is largely conserved despite lower sequence identity between bacterial clamps. Overall the results suggest that other as-yet-unidentified factors may mediate interactions between the clamp, LigA and DNA in mycobacteria. PMID:22545130

  1. Umbilical cord clamping at birth--practice in Norwegian maternity wards.

    PubMed

    Lundberg, Camilla; Øian, Pål; Klingenberg, Claus

    2013-11-26

    The timing and practice used for umbilical cord clamping of neonates are controversial internationally as well as in Norway. We therefore wished to investigate routines and practices for umbilical cord clamping of neonates in Norway. A web-based questionnaire was sent to heads of departments of all maternity wards in Norway (n = 52). They were asked about their practice with regard to umbilical cord clamping of neonates and whether written routines had been prepared for this purpose. We defined early umbilical cord clamping as immediate or within 30 seconds and late clamping as ≥ 1 minute or not until pulsation in the umbilical cord had ceased. Fifty (96%) of the maternity institutions returned a completed questionnaire. Twelve institutions (24%) reported to clamp the umbilical cord of full-term neonates early, and 38 (76%) reported to practise late clamping. Nineteen maternity wards (38%) followed written routines for umbilical cord clamping of full-term neonates, and among these, early umbilical cord clamping was practised in nine (47%). In the 31 maternity wards that had no written routines, early umbilical cord clamping was practised in three (10%). Twenty-seven of the maternity wards reported that the child is placed on the maternal abdomen before clamping of the umbilical cord, 14 reported that the child commonly is held below the introitus before umbilical cord clamping, and the rest did not report any consistent practice. There is wide variation in the practice for umbilical cord clamping in Norwegian maternity wards, many of which have no written guidelines. We argue that national guidelines for umbilical cord clamping of neonates should be established.

  2. Analysis of motion during the breast clamping phase of mammography.

    PubMed

    Ma, Wang Kei; McEntee, Mark F; Mercer, Claire; Kelly, Judith; Millington, Sara; Hogg, Peter

    2016-01-01

    To measure paddle motion during the clamping phase of a breast phantom for a range of machine/paddle combinations. A deformable breast phantom was used to simulate a female breast. 12 mammography machines from three manufacturers with 22 flexible and 20 fixed paddles were evaluated. Vertical motion at the paddle was measured using two calibrated linear potentiometers. For each paddle, the motion in millimetres was recorded every 0.5 s for 40 s, while the phantom was compressed with 80 N. Independent t-tests were used to determine differences in paddle motion between flexible and fixed, small and large, GE Senographe Essential (General Electric Medical Systems, Milwaukee, WI) and Hologic Selenia Dimensions paddles (Hologic, Bedford, MA). Paddle tilt in the medial-lateral plane for each machine/paddle combination was calculated. All machine/paddle combinations demonstrate highest levels of motion during the first 10 s of the clamping phase. The least motion is 0.17 ± 0.05 mm/10 s (n = 20) and the most motion is 0.51 ± 0.15 mm/10 s (n = 80). There is a statistical difference in paddle motion between fixed and flexible (p < 0.001), GE Senographe Essential and Hologic Selenia Dimensions paddles (p < 0.001). Paddle tilt in the medial-lateral plane is independent of time and varied from 0.04 ° to 0.69 °. All machine/paddle combinations exhibited motion and tilting, and the extent varied with machine and paddle sizes and types. This research suggests that image blurring will likely be clinically insignificant 4 s or more after the clamping phase commences.

  3. Analysis of motion during the breast clamping phase of mammography

    PubMed Central

    McEntee, Mark F; Mercer, Claire; Kelly, Judith; Millington, Sara; Hogg, Peter

    2016-01-01

    Objective: To measure paddle motion during the clamping phase of a breast phantom for a range of machine/paddle combinations. Methods: A deformable breast phantom was used to simulate a female breast. 12 mammography machines from three manufacturers with 22 flexible and 20 fixed paddles were evaluated. Vertical motion at the paddle was measured using two calibrated linear potentiometers. For each paddle, the motion in millimetres was recorded every 0.5 s for 40 s, while the phantom was compressed with 80 N. Independent t-tests were used to determine differences in paddle motion between flexible and fixed, small and large, GE Senographe Essential (General Electric Medical Systems, Milwaukee, WI) and Hologic Selenia Dimensions paddles (Hologic, Bedford, MA). Paddle tilt in the medial–lateral plane for each machine/paddle combination was calculated. Results: All machine/paddle combinations demonstrate highest levels of motion during the first 10 s of the clamping phase. The least motion is 0.17 ± 0.05 mm/10 s (n = 20) and the most motion is 0.51 ± 0.15 mm/10 s (n = 80). There is a statistical difference in paddle motion between fixed and flexible (p < 0.001), GE Senographe Essential and Hologic Selenia Dimensions paddles (p < 0.001). Paddle tilt in the medial–lateral plane is independent of time and varied from 0.04 ° to 0.69 °. Conclusion: All machine/paddle combinations exhibited motion and tilting, and the extent varied with machine and paddle sizes and types. Advances in knowledge: This research suggests that image blurring will likely be clinically insignificant 4 s or more after the clamping phase commences. PMID:26739577

  4. Nonlinear vibrations of fluid-filled clamped circular cylindrical shells

    NASA Astrophysics Data System (ADS)

    Karagiozis, K. N.; Amabili, M.; Païdoussis, M. P.; Misra, A. K.

    2005-12-01

    In this study, the nonlinear vibrations are investigated of circular cylindrical shells, empty or fluid-filled, clamped at both ends and subjected to a radial harmonic force excitation. Two different theoretical models are developed. In the first model, the standard form of the Donnell's nonlinear shallow-shell equations is used; in the second, the equations of motion are derived by a variational approach which permits the inclusion of constraining springs at the shell extremities and taking in-plane inertial terms into account. In both cases, the solution includes both driven and companion modes, thus allowing for a travelling wave in the circumferential direction; they also include axisymmetric modes to capture the nonlinear inward shell contraction and the correct type (softening) nonlinear behaviour observed in experiments. In the first model, the clamped beam eigenfunctions are used to describe the axial variations of the shell deformation, automatically satisfying the boundary conditions, leading to a 7 degree-of-freedom (dof) expansion for the solution. In the second model, rotational springs are used at the ends of the shell, which when large enough reproduce a clamped end; the solution involves a sine series for axial variations of the shell deformation, leading to a 54 dof expansion for the solution. In both cases the modal expansions satisfy the boundary conditions and the circumferential continuity condition exactly. The Galerkin method is used to discretize the equations of motion, and AUTO to integrate the discretized equations numerically. When the shells are fluid-filled, the fluid is assumed to be incompressible and inviscid, and the fluid structure interaction is described by linear potential flow theory. The results from the two theoretical models are compared with existing experimental data, and in all cases good qualitative and quantitative agreement is observed.

  5. Clamped seismic metamaterials: ultra-low frequency stop bands

    NASA Astrophysics Data System (ADS)

    Achaoui, Y.; Antonakakis, T.; Brûlé, S.; Craster, R. V.; Enoch, S.; Guenneau, S.

    2017-06-01

    The regularity of earthquakes, their destructive power, and the nuisance of ground vibration in urban environments, all motivate designs of defence structures to lessen the impact of seismic and ground vibration waves on buildings. Low frequency waves, in the range 1-10 Hz for earthquakes and up to a few tens of Hz for vibrations generated by human activities, cause a large amount of damage, or inconvenience; depending on the geological conditions they can travel considerable distances and may match the resonant fundamental frequency of buildings. The ultimate aim of any seismic metamaterial, or any other seismic shield, is to protect over this entire range of frequencies; the long wavelengths involved, and low frequency, have meant this has been unachievable to date. Notably this is scalable and the effects also hold for smaller devices in ultrasonics. There are three approaches to obtaining shielding effects: bragg scattering, locally resonant sub-wavelength inclusions and zero-frequency stop-band media. The former two have been explored, but the latter has not and is examined here. Elastic flexural waves, applicable in the mechanical vibrations of thin elastic plates, can be designed to have a broad zero-frequency stop-band using a periodic array of very small clamped circles. Inspired by this experimental and theoretical observation, all be it in a situation far removed from seismic waves, we demonstrate that it is possible to achieve elastic surface (Rayleigh) wave reflectors at very large wavelengths in structured soils modelled as a fully elastic layer periodically clamped to bedrock. We identify zero frequency stop-bands that only exist in the limit of columns of concrete clamped at their base to the bedrock. In a realistic configuration of a sedimentary basin 15 m deep we observe a zero frequency stop-band covering a broad frequency range of 0-30 Hz.

  6. The linear polarization of 3C 345 in the ultraviolet

    NASA Technical Reports Server (NTRS)

    Dolan, Joseph F.; Boyd, Patricia T.; Wolinski, Karen G.; Smith, Paul S.; Impey, C. D.; Bless, Robert C.; Nelson, M. J.; Percival, J. W.; Taylor, M. J.; Elliot, J. L.

    1994-01-01

    The linear polarization of 3C 345, a superluminal radio source and OVV quasar, was observed in two bandpasses in the ultraviolet (centered at 2160 A and 2770 A) in 1993 April using the High Speed Photometer on the Hubble Space Telescope. The quasar is significantly polarized in the UV (p greater than 5%). Ground-based polarimetry was obtained 11 days later, but a difference in the position angle between the observations in the visible and those in the UV indicate that the magnitude of the polarization of 3C 345 may have changed over that time. If the two observation sets represent the same state of spectral polarization, then the large UV flux implies that either the polarization of the synchrotron continuum must stop decreasing in the UV, or that there is an additional source of polarized flux in the ultraviolet. Only if the UV observations represent a spectral polarization state with the same position angle in the visible seen previously in 3C 345 can the polarized flux be represented by a single power law consistent with the three-component model of Smith et al. This model consists of a polarized synchrotron component, an unpolarized component from the broad-line region, and an unpolarized component attributed to thermal radiation from an optically thick accretion disk. Additional simultaneous polarimetry in the UV and visible will be required to further constrain models of the continuum emission processes in 3C 345 and determine if the UV polarized flux is synchrotron in origin.

  7. Microwave Radiometer – 3 Channel (MWR3C) Handbook

    SciTech Connect

    Cadeddu, MP

    2012-05-04

    The microwave radiometer 3-channel (MWR3C) provides time-series measurements of brightness temperatures from three channels centered at 23.834, 30, and 89 GHz. These three channels are sensitive to the presence of liquid water and precipitable water vapor.

  8. 223 GHz VLBI observations of 3C 273

    NASA Astrophysics Data System (ADS)

    Padin, S.; Woody, D. P.; Hodges, M. W.; Rogers, A. E. E.; Emerson, D. T.; Jewell, P. R.; Lamb, J.; Perfetto, A.; Wright, M. C. H.

    1990-09-01

    In the first 1.4 mm wavelength VLBI test observations, fringes have been detected on the active nucleus of 3C 273 on a baseline from Owens Valley Radio Observatory to Kitt Peak. The observations are consistent with a source whose angular size is smaller than 0.5 mas.

  9. VLBI Observations of the Radio Jet in 3C273

    NASA Astrophysics Data System (ADS)

    Unwin, S. C.; Davis, R. J.

    The authors present a new high dynamic range map of the quasar 3C 273, made from observations with a VLBI network of 12 telescopes. This new map at 18 cm wavelength has one of the highest dynamic ranges yet achieved with VLBI, and it shows the 'jet' extending to at least 180 milliarcsec, or 330 pc from the nucleus of the quasar.

  10. Nanomechanics of PCNA: A protein-made DNA sliding clamp

    NASA Astrophysics Data System (ADS)

    Rydzewski, Jakub; Strzalka, Wojciech; Nowak, Wieslaw

    2015-08-01

    Proliferating Cell Nuclear Antigen (PCNA) is a homotrimeric DNA sliding clamp involved in DNA replication, repair and cell cycle control. Understanding determinants of mechanical stability of a PCNA monomer composed of two N- and C-terminal domains requires all-atom and coarse-grained steered molecular dynamics simulations. Three schemes of unfolding at a single molecule level indicate that the conserved curvature of the PCNA monomer is due to aggregation of side β-sheets. The force spectra suggest that rupturing an interface between the domains is less probable than opening an interface between the two monomers during PCNA loading onto DNA by Replication Factor C.

  11. Normal-Pressure Tests of Circular Plates with Clamped Edges

    NASA Technical Reports Server (NTRS)

    Mcpherson, Albert E; Ramberg, Walter; Levy, Samuel

    1942-01-01

    A fixture is described for making normal-pressure tests of flat plates 5 inches in diameter in which particular care was taken to obtain rigid clamping at the edges. Results are given for 19 plates, ranging in thickness form 0.015 to 0.072 inch. The center deflections and the extreme-fiber stresses at low pressures were found to agree with theoretical values; the center deflections at high pressures were 4 to 12 percent greater than the theoretical values. Empirical curves are derived of the pressure for the beginning of the permanent set as a function of the dimensions of the plate and the tensile properties of the material.

  12. [Time of cord clamping and neonatal complications, a prospective study].

    PubMed

    Rincón, D; Foguet, A; Rojas, M; Segarra, E; Sacristán, E; Teixidor, R; Ortega, A

    2014-09-01

    To assess the effects of early or late clamping of the umbilical cord in term newborns, assessing the levels of hemoglobin, hematocrit, and ferritin, and their correlation with some of the complications. A prospective study of healthy newborns at term or born by dystotic or eutocic delivery in our hospital between May 2009 until May 2010. Patients were assigned according to the time of clamping, group 1 (<60 seconds), group 2 (1 to<2 minutes), and group 3 (2 to 3 minutes). Laboratory tests were performed at birth and at 48 hours of life, assessing the levels of hemoglobin, hematocrit, ferritin, and bilirubin. The risk of polycythemia, respiratory distress syndrome, neonatal phototherapy or admission to the Intensive Care Unit and the hospital stay, were evaluated. A total of 242 patients were included: group 1 (g1=80), group 2 (g2=31) y group 3 (g3=131). The background maternal and neonatal characteristics were similar in all sets. The first test showed significant differences in ferritin levels in those infants with delayed clamping (g1: 111 mg/dl, g2: 125 mg/dl, g3: 173 mg/dl; p<0.01). In the second analysis the values of hemoglobin (g1: 17.3 g/dl, g2: 18.9 g/dl, g3: 19.2 g/dl; p<0.01), hematocrit (g1: 53.4%, g2: 58%, g3: 59%; p<0.01) and ferritin (g1: 254 mg/dl, g2: 254.7 mg/dl, g3: 313 mg/dl; p = 0.008) were statistically higher in this group. As regards complications, a significant increase was observed in the number of cases of polycythemia symptoms in group 3. The late cord clamping is associated with an increase in hematocrit, hemoglobin and ferritin at 48 hours of life, as well as an increased risk of polycythemia present with symptoms. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  13. Timing of umbilical cord clamping and neonatal haematological status.

    PubMed

    Jaleel, Riffat; Deeba, Farah; Khan, Ayesha

    2009-07-01

    To determine the effect of delayed umbilical cord clamping on Hb (haemoglobin) and bilirubin levels of neonates and to identify newborn babies with anaemia and refer them for treatment. This Randomized Controlled Trial was conducted in the Department of Obstetrics and Gynaecology, Unit V, Dow Medical College and Lyari General Hospital and Department of Pathology, Lyari General Hospital, between 1st November, 2006 and 15th July, 2007. Patients admitted to labour ward were selected according to inclusion criteria of the study. They were randomly allocated to 2 groups. Group A included women in whom umbilical cord was clamped immediately after birth. In Group B, clamping was delayed until cessation of pulsations in the cord. After cutting the cord, sample of blood was collected from the cut end of cord of the newborn for Hb and bilirubin. After 6 hours of birth, another sample of blood was drawn from antecubital vein for serum bilirubin. Samples were sent to laboratory for analysis. All data were entered and analyzed using SPSS version 11. Two hundred women were studied, 100 in each of the 2 groups. Mean maternal Hb was 9.75 g/dl in Group A and 9.95 g/dl in Group B. The average neonatal Hb was 14.1 g/dl in Group A and 15.2 g/dl in Group B (p = 0.008). In all 49% neonates in Group A and 37% in Group B had Hb < 14 g/dl. Serum bilirubin values at birth and at 6 hours of birth were 1.8 mg/dl and 2.5 mg/dl for Group A and 1.9 mg/dl and 2.7 mg/dl for Group B, respectively. The difference in bilirubin after 6 hours in the 2 groups was insignificant (p = 0.186). Delayed umbilical cord clamping at birth seems to be safe and can be expected to reduce the prevalence of anaemic newborn babies in our community.

  14. Potassium Chloride Versus Voltage Clamp Contractures in Ventricular Muscle

    NASA Astrophysics Data System (ADS)

    Morad, M.; Reeck, S.; Rao, M.

    1981-01-01

    In frog ventricle, developed tension was markedly larger in response to depolarization caused by a voltage clamp step than to depolarization induced by high concentrations of potassium chloride. Measurement of extracellular potassium activity at the surface and at the depth of muscle during the development of contractures showed that the diffusion of potassium is much slower than the spread of depolarization through the cross section of muscle. These two observations suggest that competition between the depolarizing and the negative inotropic effects of an increase in the extracellular potassium ion concentration may determine the time course and magnitude of contractile tension in heart muscle.

  15. Normal-pressure Tests of Circular Plates with Clamped Edges

    NASA Technical Reports Server (NTRS)

    Mcpherson, Albert E; Ramberg, Walter; Levy, Samuel

    1942-01-01

    A fixture is described for making normal-pressure tests of flat plates 5 inches in diameter in which particular care was taken to obtain rigid clamping at the edges. Results are given for 19 plates, ranging in thickness from 0.015 to 0.072 inch. The center deflections and the extreme-fiber stresses at low pressures were found to agree with theoretical values; the center deflections at high pressures were 4 to 12 percent greater than the theoretical values. Empirical curves are derived of the pressure for the beginning of permanent set as a function of the dimensions of the plate and the tensile properties of the material.

  16. From unwinding to clamping - the DEAD box RNA helicase family.

    PubMed

    Linder, Patrick; Jankowsky, Eckhard

    2011-07-22

    RNA helicases of the DEAD box family are present in all eukaryotic cells and in many bacteria and Archaea. These highly conserved enzymes are required for RNA metabolism from transcription to degradation and are therefore important players in gene expression. DEAD box proteins use ATP to unwind short duplex RNA in an unusual fashion and remodel RNA-protein complexes, but they can also function as ATP-dependent RNA clamps to provide nucleation centres that establish larger RNA-protein complexes. Structural, mechanistic and molecular biological studies have started to reveal how these conserved proteins can perform such diverse functions and how accessory proteins have a central role in their regulation.

  17. Connection Between X-Ray Emission and Relativistic Jets in the Radio Galaxies 3C 111 and 3C 120

    NASA Technical Reports Server (NTRS)

    Aller, Margo F.

    2005-01-01

    This work represents a part of a longterm study of the X-ray flux variability in radio galaxies and its relation to flux and structural changes in the associated radio jet. The work described here included: 1) continued study of the emission properties of the FR I radio galaxy 3C 120 known to exhibit a jet/disk connection from our past work; and 2) the commencement of monitoring of a second radio galaxy, the FR I1 object 3C 111 which was selected because of similar radio and X-ray properties to 3C 120, including the presence of Fe K a emission. The association between X-ray dips and new superluminal components, suggesting a picture in which the radio jet is fed by accretion events near the black hole, was identified in 3C 120 using combined RXTE and radio flux monitoring data and bi-monthly to monthly imaging data from the VLBA at 43 GHz. Such data were also obtained for both targets during the period described here. Specific goals were to more broadly investigate the X-ray dip/superluminal connection in 3C 120, thereby determining the epochs of X-ray minima and superluminal ejections more accurately (and hence more precisely determining the distance between the accretion disk and the core of the radio jet), and to determine whether a similar pattern is present in the data for a second radio galaxy. In 3C 111 a different time scale (longer time delays between X-ray dips and superluminal ejections) was expected due to the higher black hole mass implied by its higher radio luminosity: no black hole mass is published for this object but one can be determined from a PDS analysis of the RXTE data. The addition of the second source to the study would identify whether a similar connection was present in other sources and, if found, would provide important information on how time scale (and hence size scale) of accretion disk/jet systems depends on black hole mass. The grant included funding for the reduction and analysis of data obtained during the time period of Rossi

  18. Surface-downhole and crosshole geoelectrics for monitoring of brine injection at the Ketzin CO2 storage site

    NASA Astrophysics Data System (ADS)

    Rippe, Dennis; Bergmann, Peter; Labitzke, Tim; Wagner, Florian; Schmidt-Hattenberger, Cornelia

    2016-04-01

    The Ketzin pilot site in Germany is the longest operating on-shore CO2 storage site in Europe. From June 2008 till August 2013, a total of ˜67,000 tonnes of CO2 were safely stored in a saline aquifer at depths of 630 m to 650 m. The storage site has now entered the abandonment phase, and continuation of the multi-disciplinary monitoring as part of the national project "CO2 post-injection monitoring and post-closure phase at the Ketzin pilot site" (COMPLETE) provides the unique chance to participate in the conclusion of the complete life cycle of a CO2 storage site. As part of the continuous evaluation of the functionality and integrity of the CO2 storage in Ketzin, from October 12, 2015 till January 6, 2015 a total of ˜2,900 tonnes of brine were successfully injected into the CO2 reservoir, hereby simulating in time-lapse the natural backflow of brine and the associated displacement of CO2. The main objectives of this brine injection experiment include investigation of how much of the CO2 in the pore space can be displaced by brine and if this displacement of CO2 during the brine injection differs from the displacement of formation fluid during the initial CO2 injection. Geophysical monitoring of the brine injection included continuous geoelectric measurements accompanied by monitoring of pressure and temperature conditions in the injection well and two adjacent observation wells. During the previous CO2 injection, the geoelectrical monitoring concept at the Ketzin pilot site consisted of permanent crosshole measurements and non-permanent large-scale surveys (Kiessling et al., 2010). Time-lapse geoelectrical tomographies derived from the weekly crosshole data at near-wellbore scale complemented by six surface-downhole surveys at a scale of 1.5 km showed a noticeable resistivity signature within the target storage zone, which was attributed to the CO2 plume (Schmidt-Hattenberger et al., 2011) and interpreted in terms of relative CO2 and brine saturations (Bergmann

  19. Delayed Umbilical Cord Clamping in the 21st Century: Indications for Practice.

    PubMed

    Bayer, Kimberly

    2016-02-01

    Health care providers have debated the timing of umbilical cord clamping since the days of Aristotle. Delayed cord clamping was the mainstay of practice until about the 1950s when it was changed to immediate clamping on the basis of a series of blood volume studies combined with the introduction of active management of the third stage of labor. However, in recent years, several systematic reviews advise that delayed cord clamping should be used in all births for at least 30 to 60 seconds. The purpose of this article is to discuss the physiology of umbilical cord clamping, the potential benefits and adverse effects of delayed cord clamping, and how this affects the advanced practice nurse. A search of PubMed, Cochrane Reviews, and Clinical Key was used to find relevant research on the topic of umbilical cord clamping. Potential benefits of delayed cord clamping include decreased frequency of iron-deficiency anemia in the first year of life with improved neurodevelopmental outcomes in term infants, reduced need for blood transfusions, possible autologous transfusion of stem cells, and a decreased incidence of intraventricular hemorrhage. Apprehension exists regarding the feasibility of the practice as well as the potential hindrance of immediate resuscitation. There is a need to begin to look for populations for which delayed cord clamping can be implemented. Recommendations are inconsistent on the patient population and timing; therefore, further studies are needed to understand the multiple variables that affect timing of umbilical cord clamping.

  20. Randomised trial of cord clamping and initial stabilisation at very preterm birth.

    PubMed

    Duley, Lelia; Dorling, Jon; Pushpa-Rajah, Angela; Oddie, Sam J; Yoxall, Charles William; Schoonakker, Bernard; Bradshaw, Lucy; Mitchell, Eleanor J; Fawke, Joe Anthony

    2017-09-18

    For very preterm births, to compare alternative policies for umbilical cord clamping and immediate neonatal care. Parallel group randomised (1:1) trial, using sealed opaque numbered envelopes. Eight UK tertiary maternity units. 261 women expected to have a live birth before 32 weeks, and their 276 babies. Cord clamping after at least 2 min and immediate neonatal care with cord intact, or clamping within 20 s and immediate neonatal care after clamping. Intraventricular haemorrhage (IVH), death before discharge. 132 women (137 babies) were allocated clamping ≥2 min and neonatal care cord intact, and 129 (139) clamping ≤20 s and neonatal care after clamping; six mother-infant dyads were excluded (2, 4) as birth was after 35(+6) weeks, one withdrew (death data only available) (0, 1). Median gestation was 28.9 weeks for those allocated clamping ≥2 min, and 29.2 for those allocated clamping ≤20 s. Median time to clamping was 120 and 11 s, respectively. 7 of 135 infants (5.2%) allocated clamping ≥2 min died and 15 of 135 (11.1%) allocated clamping ≤20 s; risk difference (RD) -5.9% (95% CI -12.4% to 0.6%). Of live births, 43 of 134 (32%) had IVH vs 47 of 132 (36%), respectively; RD -3.5% (-14.9% to 7.8%). There were no clear differences in other outcomes for infants or mothers. This is promising evidence that clamping after at least 2 min and immediate neonatal care with cord intact at very preterm birth may improve outcome; a large trial is urgently needed. ISRCTN 21456601. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.