Science.gov

Sample records for resistance series seam

  1. "Feeling" Series and Parallel Resistances.

    ERIC Educational Resources Information Center

    Morse, Robert A.

    1993-01-01

    Equipped with drinking straws and stirring straws, a teacher can help students understand how resistances in electric circuits combine in series and in parallel. Follow-up suggestions are provided. (ZWH)

  2. "Feeling" Series and Parallel Resistances.

    ERIC Educational Resources Information Center

    Morse, Robert A.

    1993-01-01

    Equipped with drinking straws and stirring straws, a teacher can help students understand how resistances in electric circuits combine in series and in parallel. Follow-up suggestions are provided. (ZWH)

  3. Pressure increases, the formation of chromite seams, and the development of the ultramafic series in the Stillwater Complex, Montana

    USGS Publications Warehouse

    Lipin, B.R.

    1993-01-01

    This paper explores the hypothesis that chromate seams in the Stillwater Complex formed in response to periodic increases in total pressure in the chamber. Total pressure increased because of the positive ??V of nucleation of CO2 bubbles in the melt and their subsequent rise through the magma chamber, during which the bubbles increased in volume by a factor of 4-6. By analogy with the pressure changes in the summit chambers of Kilauea and Krafla volcanoes, the maximum variation was 0.2-0.25 kbar, or 5-10% of the total pressure in the Stillwater chamber. An evaluation of the likelihood of fountaining and mixing of a new, primitive liquid that entered the chamber with the somewhat more evolved liquid already in the chamber is based upon calculations using observed and inferred velocities and flow rates of basaltic magmas moving through volcanic fissures. The calculations indicate that hot, dense magma would have oozed, rather than fountained into the chamber, and early mixing of the new and residual magmas that could have resulted in chromite crystallizing alone did not take place. -from Author

  4. Capacitors with low equivalent series resistance

    NASA Technical Reports Server (NTRS)

    Fleig, Patrick Franz (Inventor); Lakeman, Charles D. E. (Inventor); Fuge, Mark (Inventor)

    2011-01-01

    An electric double layer capacitor (EDLC) in a coin or button cell configuration having low equivalent series resistance (ESR). The capacitor comprises mesh or other porous metal that is attached via conducting adhesive to one or both the current collectors. The mesh is embedded into the surface of the adjacent electrode, thereby reducing the interfacial resistance between the electrode and the current collector, thus reducing the ESR of the capacitor.

  5. Series resistance in polysilicon contacted solar cells

    SciTech Connect

    Castaner, L.; Silvestre, S.; Alcubilla, R.; Pons, J.; Carter, J.; Ashburn, P.; Markvart, T.; Luque, A.; Alonso, J.

    1994-12-31

    Series resistance values between 0.2 and 0.43 {Omega} cm{sup 2} have been obtained in solar cells contacted with polysilicon in 2.6% of the area. These values include the resistance of the polysilicon-single crystal silicon interface. Various size devices were fabricated in 4 inch wafers, and a VLSI polysilicon emitter technology was applied to fabricate polysilicon contacts to the emitter front surface. The polysilicon-silicon interface was produced using either an HF etch or RCA clean before polysilicon deposition and half of the wafers were implanted with Fluorine to assess the passivating effects on the polysilicon-silicon interface. The drive-in time of the impurities from the polysilicon into the silicon was also varied. The main results are that the series resistance is lower in all fluorinated samples, either HF or RCA. The series resistance decreased monotonically in the HF devices as the drive-in time increased from 20 feet to 80 feet whereas little change is seen in RCA devices.

  6. Pressure increases, the for­mation of chromite seams, and the development of the ultramafic series in the Stillwater Complex, Montana

    USGS Publications Warehouse

    Lipin, Bruce R.

    1993-01-01

    This paper explores the hypothesis that chromite seams in the Stillwater Complex formed in response to periodic increases in total pressure in the chamber. Total pressure increased because of the positive δV of nucleation of CO2 bubbles in the melt and their subsequent rise through the magma chamber, during which the bubbles increased in volume by a factor of 4–6. By analogy with the pressure changes in the summit chambers of Kilauea and Krafla volcanoes, the maximum variation was 0⋅2–0⋅25 kbar, or 5–10% of the total pressure in the Stillwater chamber. An evaluation of the likelihood of fountaining and mixing of a new, primitive liquid that entered the chamber with the somewhat more evolved liquid already in the chamber is based upon calculations using observed and inferred velocities and flow rates of basaltic magmas moving through volcanic fissures. The calculations indicate that hot, dense magma would have oozed, rather than fountained into the chamber, and early mixing of the new and residual magmas that could have resulted in chromite crystallizing alone did not take place.Mixing was an important process in the Stillwater magma chamber, however. After the new magma in the chamber underwent ˜5% fractional crystallization, its composition, temperature, and density approached those of the overlying liquid in the chamber and the liquids then mixed. If this process occurred many times over the course of the development of the Ultramafic series, a thick column of magma with orthopyroxene on its liquidus would have been the result. Thus, the sequence of multiple injections, fractionation, and mixing with previously fractionated magma could have been the mechanism that produced the thick bronzite cumulate layer (the Bronzitite zone) above the cyclic units.

  7. Determination of series resistance of indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Weinberg, Irving

    1991-01-01

    The series resistance of a solar cell is an important parameter, which must be minimized to achieve high cell efficiencies. The cell series resistance is affected by the starting material, its design, and processing. The theoretical approach proposed by Jia, et. al., is used to calculate the series resistance of indium phosphide solar cells. It is observed that the theoretical approach does not predict the series resistance correctly in all cases. The analysis was modified to include the use of effective junction ideality factor. The calculated results were compared with the available experimental results on indium phosphide solar cells processed by different techniques. It is found that the use of process dependent junction ideality factor leads to better estimation of series resistance. An accurate comprehensive series resistance model is warranted to give proper feedback for modifying the cell processing from the design state.

  8. Tracks Seam Like Airbags

    NASA Image and Video Library

    2004-01-28

    Bearing a striking resemblance to a cluster of paper lanterns, these inflated airbags show a pattern of seams exactly like those left in the martian soil by the Mars Exploration Rover Opportunity during landing at Meridiani Planum, Mars.

  9. Cryogenic Testing of Different Seam Concepts for Multilayer Insulation Systems

    NASA Technical Reports Server (NTRS)

    Johnson, Wesley L.; Fesmire, J. E.

    2009-01-01

    Recent testing in a cylindrical, comparative cryostat at the Cryogenics Test Laboratory has focused on various seam concepts for multilayer insulation systems. Three main types of seams were investigated: straight overlap, fold-over, and roll wrapped. Each blanket was comprised of 40 layer pairs of reflector and spacer materials. The total thickness was approximately 12.5-mm, giving an average layer density of 32 layers per centimeter. The blankets were tested at high vacuum, soft vacuum, and no vacuum using liquid nitrogen to maintain the cold boundary temperature at 77 K. Test results show that all three seam concepts are all close in thermal performance; however the fold-over method provides the lowest heat flux. For the first series of tests, seams were located 120 degrees around the circumference of the cryostat from the previous seam. This technique appears to have lessened the degradation of the blanket due to the seams. In a follow-on test, a 20 layer blanket was tested in a roll wrapped configuration and then cut down the side of the cylinder, taped together, and re-tested. This test result shows the thermal performance impact of having the seams all in one location versus having the seams clocked around the vessel. This experimental investigation indicates that the method of joining the seams in multilayer insulation systems is not as critical as the quality of the installation process.

  10. Induced polarization signature of coal seam fires

    NASA Astrophysics Data System (ADS)

    Shao, Zhenlu; Revil, André; Mao, Deqiang; Wang, Deming

    2017-03-01

    Coal seam fires are a worldwide disaster of both ecological and economic importance. Their remote detection from the ground surface or using airborne techniques is required for developing efficient strategies to extinguish them. We investigate here the use of time-domain-induced polarization to localize coal seam fires. For laboratory experiments, we first introduce a modified time-domain-induced polarization methodology to quickly acquire and invert the secondary voltage distribution mapped after the shutdown of the primary current. A set of sandbox experiments is conducted in which coal is embedded into humidified sand. Raw coal alone generates significant induced polarization anomalies, above those shown by the sand. Even higher induced polarization anomalies are detected in presence of a coal seam fire. We postulate that the higher chargeability is due to the pyrolysis, which may enhance electronic polarization or the polarization associated with the cation exchange capacity (CEC) of the material. The position of the coal seam fire is well recovered inside the tank by inverting the secondary voltages in term of a source current density distribution. We also collected field data over a recognized coal seam fire in Colorado, USA. A chargeability anomaly (∼800 mV V-1) and a resistivity anomaly (∼1 Ohm m) are observed at the position of the coal seam fire. We propose a normalized burning front index (a scaled normalized chargeability) to image and localize, without ambiguity, the position of the coal seam fire in the subsurface. The 3-D reconstructed target is located below a negative self-potential anomaly (similarly to what is observed in laboratory experiments) and a temperature anomaly recorded at a depth of 30 cm.

  11. Induced polarization signature of coal seam fires

    NASA Astrophysics Data System (ADS)

    Shao, Zhenlu; Revil, André; Mao, Deqiang; Wang, Deming

    2016-12-01

    Coal seam fires are a worldwide disaster of both ecological and economic importance. Their remote detection from the ground surface or using airborne techniques is required for developing efficient strategies to extinguish them. We investigate here the use of time-domain induced polarization to localize coal seam fires. For laboratory experiments, we first introduce a modified time-domain induced polarization methodology to quickly acquire and invert the secondary voltage distribution mapped after the shutdown of the primary current. A set of sandbox experiments is conducted in which coal is embedded into humidified sand. Raw coal alone generates significant induced polarization anomalies, significantly above those shown by the sand. Even higher induced polarization anomalies are detected in presence of a coal seam fire. We postulate that the higher chargeability is due to the pyrolysis, which may enhance electronic polarization or the polarization associated with the cation exchange capacity of the material. The position of the coal seam fire is well recovered inside the tank by inverting the secondary voltages in term of a source current density distribution. We also collected field data over a recognized coal seam fire in Colorado, USA. A chargeability anomaly (˜800 mV/V) and a resistivity anomaly (˜1 Ohm m) are observed at the position of the coal seam fire. We propose a normalized burning front index (a scaled normalized chargeability) to image and localize, without ambiguity, the position of the coal seam fire in the subsurface. The 3D reconstructed target is located below a negative self-potential anomaly (similarly to what is observed in laboratory experiments) and a temperature anomaly recorded at a depth of 30 cm.

  12. Airbag Seams Leave Trails

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image taken by the Mars Exploration Rover Opportunity's panoramic camera shows where the rover's airbag seams left impressions in the martian soil. The drag marks were made after the rover successfully landed at Meridiani Planum and its airbags were retracted. The rover can be seen in the foreground.

  13. Airbag Seams Leave Trails

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image taken by the Mars Exploration Rover Opportunity's panoramic camera shows where the rover's airbag seams left impressions in the martian soil. The drag marks were made after the rover successfully landed at Meridiani Planum and its airbags were retracted. The rover can be seen in the foreground.

  14. Tracks 'Seam' Like Airbags

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Bearing a striking resemblance to a cluster of paper lanterns, these inflated airbags show a pattern of seams exactly like those left in the martian soil by the Mars Exploration Rover Opportunity during landing at Meridiani Planum, Mars. This image was taken during airbag testing at NASA's Plum Brook Station, located about 50 miles west of Cleveland in Sandusky, Ohio and operated by NASA's Glenn Research Center.

  15. On the connectivity of seams of conical intersection: seam curvature.

    PubMed

    Yarkony, David R

    2005-11-22

    The seam of conical intersection of two electronic states is said to be curved when the span of the basis vectors describing the branching plane varies along the seam. In this work degenerate perturbation theory is used to determine an approximately diabatic Hamiltonian that can reliably reproduce the potential-energy surfaces in the vicinity of a point of conical intersection. This Hamiltonian provides a rigorous description of seam curvature, and a means for obtaining the full (N(int)-2)-dimensional seam of conical intersection connected to a point of conical intersection.

  16. Tracking Connections: An Exercise about Series and Parallel Resistances

    ERIC Educational Resources Information Center

    Jankovic, Srdjan

    2010-01-01

    Unlike many other topics in basic physics, series and parallel resistances are rarely noticed in the real life of an ordinary individual, making it difficult to design a laboratory activity that can simulate something familiar. The activities described here entail minimal costs and are based on a puzzle-like game of tracking wire connections. A…

  17. Tracking Connections: An Exercise about Series and Parallel Resistances

    ERIC Educational Resources Information Center

    Jankovic, Srdjan

    2010-01-01

    Unlike many other topics in basic physics, series and parallel resistances are rarely noticed in the real life of an ordinary individual, making it difficult to design a laboratory activity that can simulate something familiar. The activities described here entail minimal costs and are based on a puzzle-like game of tracking wire connections. A…

  18. New explosive seam welding concepts

    NASA Technical Reports Server (NTRS)

    Bement, L. J.

    1973-01-01

    Recently developed techniques provide totally-confined linear explosive seam welding and produce scarf joint with linear explosive seam welding. Linear ribbon explosives are utilized in making narrow, continuous, airtight joints in variety of aluminum alloys, titanium, copper, brass, and stainless steel.

  19. Practical small-scale explosive seam welding

    NASA Technical Reports Server (NTRS)

    Bement, L. J.

    1983-01-01

    A small-scale explosive seam welding process has been developed that can significantly contribute to remote metal joining operations under hazardous or inaccessible conditions, such as nuclear reactor repair and assembly of structure in space. This paper describes this explosive seam welding process in terms of joining principles, variables, types of joints created, capabilities, and applications. Very small quantities of explosive in a ribbon configuration are used to create narrow (less than 0.5 inch), long-length, uniform, hermetically sealed joints that exhibit parent metal properties in a wide variety of metals, alloys, and combinations. The practicality of this process has been demonstrated by its current acceptance, as well as its capabilities that are superior in many applications to the universally accepted joining processes, such as mechanical fasteners, fusion and resistance welding, and adhesives.

  20. Practical small-scale explosive seam welding

    NASA Technical Reports Server (NTRS)

    Bement, L. J.

    1983-01-01

    A small-scale explosive seam welding process has been developed that can significantly contribute to remote metal joining operations under hazardous or inaccessible conditions, such as nuclear reactor repair and assembly of structure in space. This paper describes this explosive seam welding process in terms of joining principles, variables, types of joints created, capabilities, and applications. Very small quantities of explosive in a ribbon configuration are used to create narrow (less than 0.5 inch), long-length, uniform, hermetically sealed joints that exhibit parent metal properties in a wide variety of metals, alloys, and combinations. The practicality of this process has been demonstrated by its current acceptance, as well as its capabilities that are superior in many applications to the universally accepted joining processes, such as mechanical fasteners, fusion and resistance welding, and adhesives. Previously announced in STAR as N83-24896

  1. Impact of series resistance on the operation of junctionless transistors

    NASA Astrophysics Data System (ADS)

    Jeon, Dae-Young; Park, So Jeong; Mouis, Mireille; Barraud, Sylvain; Kim, Gyu-Tae; Ghibaudo, Gérard

    2017-03-01

    Transconductance (gm) and its derivative (dgm/dVg) of junctionless transistors (JLTs), considered as a possible candidate for future CMOS technology, show their unique operation properties such as bulk neutral and surface accumulation conduction. However, source/drain series resistance (Rsd) causes significant degradation of intrinsic gm and dgm/dVg behavior in JLTs. In this letter, the Rsd effects on the operation of JLTs were investigated in detail and also verified with analytical modeling equations. This work provides helpful information for a better understanding of the operation mechanism of JLTs with de-embedded Rsd effects.

  2. Tracking Connections: An Exercise about Series and Parallel Resistances

    NASA Astrophysics Data System (ADS)

    Jankovic, Srdjan

    2010-09-01

    Unlike many other topics in basic physics, series and parallel resistances are rarely noticed in the real life of an ordinary individual, making it difficult to design a laboratory activity that can simulate something familiar. The activities described here entail minimal costs and are based on a puzzle-like game of tracking wire connections. A simple resistor-based device is built by students, which enables them to use a common multimeter to track down wire connections in a set of unmarked wires. A similar approach is sometimes used by electricians to identify wire connections.

  3. The Single Needle Lockstitch Machine. [Sewing Seams.] Module 4.

    ERIC Educational Resources Information Center

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on sewing seams, one in a series on the single needle lockstitch sewing machine for student self-study, contains three sections. Each section includes the following parts: an introduction, directions, an objective, learning activities, student information, student self-check, check-out activities, and an instructor's final checklist.…

  4. The Single Needle Lockstitch Machine. [Sewing Seams.] Module 4.

    ERIC Educational Resources Information Center

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on sewing seams, one in a series on the single needle lockstitch sewing machine for student self-study, contains three sections. Each section includes the following parts: an introduction, directions, an objective, learning activities, student information, student self-check, check-out activities, and an instructor's final checklist.…

  5. Bursting at the seams

    NASA Image and Video Library

    2016-06-27

    This NASA/ESA Hubble Space Telescope image reveals the iridescent interior of one of the most active galaxies in our local neighbourhood — NGC 1569, a small galaxy located about eleven million light-years away in the constellation of Camelopardalis (The Giraffe). This galaxy is currently a hotbed of vigorous star formation. NGC 1569 is a starburst galaxy, meaning that — as the name suggests — it is bursting at the seams with stars, and is currently producing them at a rate far higher than that observed in most other galaxies. For almost 100 million years, NGC 1569 has pumped out stars over 100 times faster than the Milky Way! As a result, this glittering galaxy is home to super star clusters, three of which are visible in this image — one of the two bright clusters is actually  the superposition of two massive clusters. Each containing more than a million stars, these brilliant blue clusters reside within a large cavity of gas carved out by multiple supernovae, the energetic remnants of massive stars. In 2008, Hubble observed the galaxy's cluttered core and sparsely populated outer fringes. By pinpointing individual red giant stars, Hubble’s Advanced Camera for Surveys enabled astronomers to calculate a new — and much more precise — estimate for NGC 1569’s distance. This revealed that the galaxy is actually one and a half times further away than previously thought, and a member of the IC 342 galaxy group. Astronomers suspect that the IC 342 cosmic congregation is responsible for the star-forming frenzy observed in NGC 1569. Gravitational interactions between this galactic group are believed to be compressing the gas within NGC 1569. As it is compressed, the gas collapses, heats up and forms new stars.

  6. Thin stillage fractionation using ultrafiltration: resistance in series model.

    PubMed

    Arora, Amit; Dien, Bruce S; Belyea, Ronald L; Wang, Ping; Singh, Vijay; Tumbleson, M E; Rausch, Kent D

    2009-02-01

    The corn based dry grind process is the most widely used method in the US for fuel ethanol production. Fermentation of corn to ethanol produces whole stillage after ethanol is removed by distillation. It is centrifuged to separate thin stillage from wet grains. Thin stillage contains 5-10% solids. To concentrate solids of thin stillage, it requires evaporation of large amounts of water and maintenance of evaporators. Evaporator maintenance requires excess evaporator capacity at the facility, increasing capital expenses, requiring plant slowdowns or shut downs and results in revenue losses. Membrane filtration is one method that could lead to improved value of thin stillage and may offer an alternative to evaporation. Fractionation of thin stillage using ultrafiltration was conducted to evaluate membranes as an alternative to evaporators in the ethanol industry. Two regenerated cellulose membranes with molecular weight cut offs of 10 and 100 kDa were evaluated. Total solids (suspended and soluble) contents recovered through membrane separation process were similar to those from commercial evaporators. Permeate flux decline of thin stillage using a resistance in series model was determined. Each of the four components of total resistance was evaluated experimentally. Effects of operating variables such as transmembrane pressure and temperature on permeate flux rate and resistances were determined and optimum conditions for maximum flux rates were evaluated. Model equations were developed to evaluate the resistance components that are responsible for fouling and to predict total flux decline with respect to time. Modeling results were in agreement with experimental results (R(2) > 0.98).

  7. Stereoscopic Video Weld-Seam Tracker

    NASA Technical Reports Server (NTRS)

    Kennedy, Larry Z.

    1991-01-01

    Stereoscopic video camera and laser illuminator operates in conjunction with image-data-processing computer to locate weld seam and to map surface features in vicinity of seam. Intended to track seams to guide placement of welding torch in automatic welding system and to yield information on qualities of welds. More sensitive than prior optical seam trackers and suitable for use in production environment. Tracks nearly invisible gap between butted machined edges of two plates.

  8. Behind the Seams.

    ERIC Educational Resources Information Center

    Watt, W. Bradford

    2000-01-01

    Discusses the use of seamless flooring in areas where cleanliness, waterproofing, and slip resistance is emphasized. Areas such as locker rooms, restrooms, kitchens and cafeterias, lobbies and hallways, multipurpose-rooms, and walkways are considered. (GR)

  9. Adult Education and Radical Habitus in an Environmental Campaign: Learning in the Coal Seam Gas Protests in Australia

    ERIC Educational Resources Information Center

    Ollis, Tracey; Hamel-Green, Michael

    2015-01-01

    This paper examines the adult learning dimensions of protestors as they participate in a campaign to stop coal seam gas exploration in Gippsland in Central Victoria, Australia. On a global level, the imposition of coal seam gas exploration by governments and mining companies has been the trigger for movements of resistance from environmental…

  10. On the determination of series resistance and diode quality factor of solar cells

    NASA Technical Reports Server (NTRS)

    Anderson, R. L.

    1976-01-01

    The series resistance and diode quality factor are used for evaluation of solar cell performance. These parameters are normally deduced from the terminal I-V characteristics under forward bias. The method produces a smaller series resistance and a larger value for diode quality factor than appropriate for the device when operating as a solar cell. It is suggested that the diode quality factor be determined from measured saturated photocurrent, open circuit voltage characteristics and the series resistance be measured with an r-f bridge or calculated from a measurement of the surface sheet resistance.

  11. On the determination of series resistance and diode quality factor of solar cells

    NASA Technical Reports Server (NTRS)

    Anderson, R. L.

    1976-01-01

    The series resistance and diode quality factor are used for evaluation of solar cell performance. These parameters are normally deduced from the terminal I-V characteristics under forward bias. The method produces a smaller series resistance and a larger value for diode quality factor than appropriate for the device when operating as a solar cell. It is suggested that the diode quality factor be determined from measured saturated photocurrent, open circuit voltage characteristics and the series resistance be measured with an r-f bridge or calculated from a measurement of the surface sheet resistance.

  12. Distributed Seams for Gigapixel Panoramas.

    PubMed

    Philip, Sujin; Summa, Brian; Tierny, Julien; Bremer, Peer-Timo; Pascucci, Valerio

    2015-03-01

    Gigapixel panoramas are an increasingly popular digital image application. They are often created as a mosaic of many smaller images. The mosaic acquisition can take many hours causing the individual images to differ in exposure and lighting conditions. A blending operation is often necessary to give the appearance of a seamless image. The blending quality depends on the magnitude of discontinuity along the image boundaries. Often, new boundaries, or seams, are first computed that minimize this transition. Current techniques based on multi-labeling Graph Cuts are too slow and memory intensive for gigapixel sized panoramas. In this paper, we present a parallel, out-of-core seam computing technique that is fast, has small memory footprint, and is capable of running efficiently on different types of parallel systems. Its maximum memory usage is configurable, in the form of a cache, which can improve performance by reducing redundant disk I/O and computations. It shows near-perfect scaling on symmetric multiprocessing systems and good scaling on clusters and distributed shared memory systems. Our technique improves the time required to compute seams for gigapixel imagery from many hours (or even days) to just a few minutes, while still producing boundaries with energy that is on-par with Graph Cuts.

  13. Determination of internal series resistance of PV devices: repeatability and uncertainty

    NASA Astrophysics Data System (ADS)

    Trentadue, Germana; Pavanello, Diego; Salis, Elena; Field, Mike; Müllejans, Harald

    2016-05-01

    The calibration of photovoltaic devices requires the measurement of their current-voltage characteristics at standard test conditions (STC). As the latter can only be reached approximately, a curve translation is necessary, requiring among others the internal series resistance of the photovoltaic device as an input parameter. Therefore accurate and reliable determination of the series resistance is important in measurement and test laboratories. This work follows standard IEC 60891 ed 2 (2009) for the determination of the internal series resistance and investigates repeatability and uncertainty of the result in three aspects for a number of typical photovoltaic technologies. Firstly the effect of varying device temperature on the determined series resistance is determined experimentally and compared to a theoretical derivation showing agreement. It is found that the series resistance can be determined with an uncertainty of better than 5% if the device temperature is stable within  ±0.1 °C, whereas the temperature range of  ±2 °C allowed by the standard leads to much larger variations. Secondly the repeatability of the series resistance determination with respect to noise in current-voltage measurement is examined yielding typical values of  ±5%. Thirdly the determination of the series resistance using three different experimental set-ups (solar simulators) shows agreement on the level of  ±5% for crystalline Silicon photovoltaic devices and deviations up to 15% for thin-film devices. It is concluded that the internal series resistance of photovoltaic devices could be determined with an uncertainty of better than 10%. The influence of this uncertainty in series resistance on the electrical performance parameters of photovoltaic devices was estimated and showed a contribution of 0.05% for open-circuit voltage and 0.1% for maximum power. Furthermore it is concluded that the range of device temperatures allowed during determination of series

  14. A Laboratory Exercise in Physics: Determining the Resistance of Single Resistors and Series and Parallel Combinations of Resistance.

    ERIC Educational Resources Information Center

    Schlenker, Richard M.

    Presented is a secondary level physics unit which introduces students to electrical resistance in series and parallel combinations, use of the voltmeter and ammeter, wiring simple circuits, and writing scientific reports. (SL)

  15. A Laboratory Exercise in Physics: Determining the Resistance of Single Resistors and Series and Parallel Combinations of Resistance.

    ERIC Educational Resources Information Center

    Schlenker, Richard M.

    Presented is a secondary level physics unit which introduces students to electrical resistance in series and parallel combinations, use of the voltmeter and ammeter, wiring simple circuits, and writing scientific reports. (SL)

  16. Exploring the Conical Intersection Seam: The Seam Space Nudged Elastic Band Method.

    PubMed

    Mori, Toshifumi; Martínez, Todd J

    2013-02-12

    Conical intersections (CIs) play a fundamental role in photoreactions. Although it is widely known that CIs are not isolated points but rather multidimensional seams, there is a dearth of techniques to explore and characterize these seams beyond the immediate vicinity of minimum energy points within the intersection space (minimum energy conical intersections or MECIs). Here, we develop a method that connects these MECIs by minimal energy paths within the space of geometries that maintain the electronic degeneracy (the "seam space") in order to obtain a more general picture of a CI seam. This method, the seam space nudged elastic band (SS-NEB) method, combines the nudged elastic band method with gradient projected MECI optimization. It provides a very efficient way of finding minimum energy seam paths in the conical intersection seam. The method is demonstrated by application to two molecules: ethylene and the green fluorescent protein (GFP) chromophore. The results show that previously known MECIs for these molecules are connected within a single seam, adding further support to previous conjectures that all MECIs are topologically connected in the seam space. Analysis of the nonadiabatic dynamics further suggests that a broad range of seam geometries, not only the vicinity of MECIs, is involved in the nonadiabatic transition events. The current method provides a tool to characterize CI seams in different environments and to explore the importance of the seam in the dynamics.

  17. Real-time Series Resistance Monitoring in PV Systems; NREL (National Renewable Energy Laboratory)

    SciTech Connect

    Deceglie, M. G.; Silverman, T. J.; Marion, B.; Kurtz, S. R.

    2015-06-14

    We apply the physical principles of a familiar method, suns-Voc, to a new application: the real-time detection of series resistance changes in modules and systems operating outside. The real-time series resistance (RTSR) method that we describe avoids the need for collecting IV curves or constructing full series-resistance-free IV curves. RTSR is most readily deployable at the module level on apply the physical principles of a familiar method, suns-Voc, to a new application: the real-time detection of series resistance changes in modules and systems operating outside. The real-time series resistance (RTSR) method that we describe avoids the need for collecting IV curves or constructing full series-resistance-free IV curves. RTSR is most readily deployable at the module level on micro-inverters or module-integrated electronics, but it can also be extended to full strings. Automated detection of series resistance increases can provide early warnings of some of the most common reliability issues, which also pose fire risks, including broken ribbons, broken solder bonds, and contact problems in the junction or combiner box. We describe the method in detail and describe a sample application to data collected from modules operating in the field.

  18. Longwall mining of thin seams

    SciTech Connect

    Curth, E A

    1981-01-01

    Thin seam operations pose a challenge to the ingenuity of mining engineers to overcome the factor of human inconvenience in the restricted environment and associated high cost production. Surprisingly, low seam longwalls in the Federal Republic of Germany in an average thickness of 35 in. and dipping less than 18/sup 0/ come close to achieving the average production rate of all German longwall operations. They are all plow faces, and a consistent production of 3300 tons per day and a productivity of 40 tons per man shift are reported from one of the thin seam longwalls. These results were attained by reliable high-capacity equipment and roof support by shields that can be collapsed to as low as 22 inches. Maximum mining height for plow operated faces lies at 31.5 inches. Technology for mechanized mining of flat lying coalbeds less than 31.5 inches in thickness without rock cutting is not available, and firmness of coal, undulation of the strata, coalbed thickness variation, and the necessity of cutting rock, particularly through faults, set limits to plow application. The in-web shearer can be used in firm coal to a minimum mining height of 40 inches, and a daily production of 1650 to 2200 tons is reported from a longwall in the Saar district of Germany equipped with such a shearer and shields. Numerous in-web shearers are employed in the United Kingdom; reports as to their success are contradictory. Also, experience in the United States, though limited, has been negative. The steady increase in output from single drum shearer faces in Pennsylvania is a remarkable achievement, and occasional record breaking peaks in production indicate the potential of such mining. Technology development for the future is discussed.

  19. Distributed series resistance effects in solar cells: Dark and illuminated cases

    SciTech Connect

    Araujo, G.L.; Cuevas, A.; Ruiz, J.M.

    1984-05-01

    A new approach to calculate the distributed series resistance of a solar cell is presented. Since we include the contribution of the substrate resistance, our approach is more general than previous ones. Analytical solutions for the variation of r /SUB s/ for dark, short and open-circuit operation conditions are given. The authors show that the series resistance depends on flowing current and can be different in the dark and under illumination conditions, due to current crowding effects in the emitter layer. But it is also shown that this crowding can be significantly attenuated by the presence of substrate resistivity.

  20. Research of the electrical anisotropic characteristics of water-conducting fractured zones in coal seams

    NASA Astrophysics Data System (ADS)

    Su, Ben-Yu; Yue, Jian-Hua

    2017-06-01

    Water flooding disasters are one of the five natural coal-mining disasters that threaten the lives of coal miners. The main causes of this flooding are water-conducting fractured zones within coal seams. However, when resistivity methods are used to detect water-conducting fractured zones in coal seams, incorrect conclusions can be drawn because of electrical anisotropy within the water-conducting fractured zones. We present, in this paper, a new geo-electrical model based on the geology of water-conducting fractured zones in coal seams. Factors that influence electrical anisotropy were analyzed, including formation water resistivity, porosity, fracture density, and fracture surface roughness, pressure, and dip angle. Numerical simulation was used to evaluate the proposed electrical method. The results demonstrate a closed relationship between the shape of apparent resistivity and the strike and dip of a fracture. Hence, the findings of this paper provide a practical resistivity method for coal-mining production.

  1. On the locus of points of conical intersection: seams near seams.

    PubMed

    Schuurman, Michael S; Yarkony, David R

    2007-01-28

    The existence of a seam of conical intersection, the reference seam, does not rule out the existence of additional disjoint seams of conical intersection. These disjoint seams intersect the g-h planes of the reference seam, a region usually assumed to be devoid of intersections, potentially leading to unexpected points of degeneracy in close proximity to the original conical intersection. Here the authors show how the locus of these disjoint seams can be predicted employing a Hamiltonian derived from second-order perturbation theory. Dramatic differences between the g-h planes of the reference and disjoint seams are found and are expected to have a profound impact on nuclear dynamics. Numerical studies of both high symmetry (D(3h), C(3)H(3)) and low symmetry (C(2v), C(2)H(2)N) species are presented.

  2. Depth-aware image seam carving.

    PubMed

    Shen, Jianbing; Wang, Dapeng; Li, Xuelong

    2013-10-01

    Image seam carving algorithm should preserve important and salient objects as much as possible when changing the image size, while not removing the secondary objects in the scene. However, it is still difficult to determine the important and salient objects that avoid the distortion of these objects after resizing the input image. In this paper, we develop a novel depth-aware single image seam carving approach by taking advantage of the modern depth cameras such as the Kinect sensor, which captures the RGB color image and its corresponding depth map simultaneously. By considering both the depth information and the just noticeable difference (JND) model, we develop an efficient JND-based significant computation approach using the multiscale graph cut based energy optimization. Our method achieves the better seam carving performance by cutting the near objects less seams while removing distant objects more seams. To the best of our knowledge, our algorithm is the first work to use the true depth map captured by Kinect depth camera for single image seam carving. The experimental results demonstrate that the proposed approach produces better seam carving results than previous content-aware seam carving methods.

  3. Arch mineral pursues multiple dipping seams

    SciTech Connect

    Sprouls, M.W.

    1981-07-01

    Arch Mineral's three Hanna Basin mines in Carbon County, WY, recover about eight million tpy from more than a dozen coal seams. Arch's experience has proven stripping techniques for dipping seams, and has revealed better methods for recontouring and revegetating mined land.

  4. 3D analysis of the performances degradation caused by series resistance in concentrator solar cells

    SciTech Connect

    Daliento, Santolo; Lancellotti, Laura

    2010-01-15

    This paper deals with the modeling of series resistance components in silicon concentrator solar cells. The main components of the macroscopic series resistance are analyzed by means of one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) numerical simulations. It is shown that the contribution of the lateral current flux, flowing along the emitter region, and of the transverse current flux, flowing along the metal grid, cannot be neglected and, hence, the operation of solar cells subjected to high current densities cannot be described by simple one-dimensional models. The percentage weight of 2D and 3D components on the total value of the series resistance is evaluated and rules for the proper design of the cell geometries are given. An analysis of the effectiveness of the most popular methods for the extraction of the series resistance from the I-V curves of solar cells is also proposed. (author)

  5. Real-Time Series Resistance Monitoring in PV Systems Without the Need for IV Curves

    SciTech Connect

    Deceglie, Michael G.; Silverman, Timothy J.; Marion, Bill; Kurtz, Sarah R.

    2015-06-14

    We apply the physical principles of a familiar method, suns-Voc, to a new application: the real-time detection of series resistance changes in modules and systems operating outside. The real-time series resistance (RTSR) method that we describe avoids the need for collecting IV curves or constructing full series-resistance-free IV curves. RTSR is most readily deployable at the module level on micro-inverters or module-integrated electronics, but it can also be extended to full strings. Automated detection of series resistance increases can provide early warnings of some of the most common reliability issues, which also pose fire risks, including broken ribbons, broken solder bonds, and contact problems in the junction or combiner box. We describe the method in detail and describe a sample application to data collected from modules operating in the field.

  6. Innovative technology summary report: Sealed-seam sack suits

    SciTech Connect

    1998-09-01

    Sealed-seam sack suits are an improved/innovative safety and industrial hygiene technology designed to protect workers from dermal exposure to contamination. Most of these disposable, synthetic-fabric suits are more protective than cotton suits, and are also water-resistant and gas permeable. Some fabrics provide a filter to aerosols, which is important to protection against contamination, while allowing air to pass, increasing comfort level of workers. It is easier to detect body-moisture breakthrough with the disposable suits than with cotton, which is also important to protecting workers from contamination. These suits present a safe and cost-effective (6% to 17% less expensive than the baseline) alternative to traditional protective clothing. This report covers the period from October 1996 to August 1997. During that time, sealed-seam sack suits were demonstrated during daily activities under normal working conditions at the C Reactor and under environmentally controlled conditions at the Los Alamos National Laboratory (LANL).

  7. Analytical relationship between arterial input impedance and the three-element Windkessel series resistance.

    PubMed

    Gnudi, G

    1998-07-01

    The recently proposed energy-balance method for estimating the series resistance of the three-element Windkessel model is reformulated in the frequency domain. New mathematical expressions are analytically derived, involving Fourier harmonics of pulsatile arterial pressure and flow. It is shown that the series resistance of the arterial three-element Windkessel model can be expressed as a weighted sum of the arterial input impedance moduli.

  8. Complete Method for E{sub bd} Correction by Series Resistance Characterization

    SciTech Connect

    Monroe, David K.; Swanson, Scot E.

    1998-10-09

    We have developed a semi-automated method for determining the series resistance profiles of dot capacitors and for obtaining corrected oxide fields at breakdown. This method is based upon a least-squares-fit of IV data obtained from a voltage-ramp test to the Fowler-Nordheim leakage model. The profiles provide insight into the general characteristics of series resistance. Certain features of the profiles can be associated with charge trapping and the onset of oxide breakdown.

  9. Module Twelve: Series AC Resistive-Reactive Circuits; Basic Electricity and Electronics Individualized Learning System.

    ERIC Educational Resources Information Center

    Bureau of Naval Personnel, Washington, DC.

    The module covers series circuits which contain both resistive and reactive components and methods of solving these circuits for current, voltage, impedance, and phase angle. The module is divided into six lessons: voltage and impedance in AC (alternating current) series circuits, vector computations, rectangular and polar notation, variational…

  10. A new method for experimental determination of the series resistance of a solar cell

    SciTech Connect

    Araujo, G.L.; Sanchez, E.

    1982-10-01

    A new method for determining the series resistance of a solar cell from illuminated I-V measurements is presented. This technique takes advantage of the special feature of integration as a procedure to smooth data errors. The R/SUB s/ obtained represents the resistive effects globally.

  11. Direct visualization of the microtubule lattice seam both in vitro and in vivo

    PubMed Central

    1994-01-01

    Microtubules are constructed from alpha- and beta-tubulin heterodimers that are arranged into protofilaments. Most commonly there are 13 or 14 protofilaments. A series of structural investigations using both electron microscopy and x-ray diffraction have indicated that there are two potential lattices (A and B) in which the tubulin subunits can be arranged. Electron microscopy has shown that kinesin heads, which bind only to beta-tubulin, follow a helical path with a 12-nm pitch in which subunits repeat every 8-nm axially, implying a primarily B-type lattice. However, these helical symmetry parameters are not consistent with a closed lattice and imply that there must be a discontinuity or "seam" along the microtubule. We have used quick-freeze deep-etch electron microscopy to obtain the first direct evidence for the presence of this seam in microtubules formed either in vivo or in vitro. In addition to a conventional single seam, we have also rarely found microtubules in which there is more than one seam. Overall our data indicates that microtubules have a predominantly B lattice, but that A lattice bonds between tubulin subunits are found at the seam. The cytoplasmic microtubules in mouse nerve cells also have predominantly B lattice structure and A lattice bonds at the seam. These observations have important implications for the interaction of microtubules with MAPs and with motor proteins, and for example, suggest that kinesin motors may follow a single protofilament track. PMID:7806574

  12. Geomorphology of coal seam fires

    NASA Astrophysics Data System (ADS)

    Kuenzer, Claudia; Stracher, Glenn B.

    2012-02-01

    Coal fires occur in underground natural coal seams, in exposed surface seams, and in coal storage or waste piles. The fires ignite through spontaneous combustion or natural or anthropogenic causes. They are reported from China, India, USA, South Africa, Australia, and Russia, as well as many other countries. Coal fires lead to loss of a valuable resource (coal), the emission of greenhouse-relevant and toxic gases, and vegetation deterioration. A dangerous aspect of the fires is the threat to local mines, industries, and settlements through the volume loss underground. Surface collapse in coal fire areas is common. Thus, coal fires are significantly affecting the evolution of the landscape. Based on more than a decade of experience with in situ mapping of coal fire areas worldwide, a general classification system for coal fires is presented. Furthermore, coal seam fire geomorphology is explained in detail. The major landforms associated with, and induced by, these fires are presented. The landforms include manifestations resulting from bedrock surface fracturing, such as fissures, cracks, funnels, vents, and sponges. Further manifestations resulting from surface bedrock subsidence include sinkholes, trenches, depressions, partial surface subsidence, large surface subsidence, and slides. Additional geomorphologic coal fire manifestations include exposed ash layers, pyrometamorphic rocks, and fumarolic minerals. The origin, evolution, and possible future development of these features are explained, and examples from in situ surveys, as well as from high-resolution satellite data analyses, are presented. The geomorphology of coal fires has not been presented in a systematic manner. Knowledge of coal fire geomorphology enables the detection of underground coal fires based on distinct surface manifestations. Furthermore, it allows judgments about the safety of coal fire-affected terrain. Additionally, geomorphologic features are indicators of the burning stage of fires

  13. Ectopic A-lattice seams destabilize microtubules.

    PubMed

    Katsuki, Miho; Drummond, Douglas R; Cross, Robert A

    2014-01-01

    Natural microtubules typically include one A-lattice seam within an otherwise helically symmetric B-lattice tube. It is currently unclear how A-lattice seams influence microtubule dynamic instability. Here we find that including extra A-lattice seams in GMPCPP microtubules, structural analogues of the GTP caps of dynamic microtubules, destabilizes them, enhancing their median shrinkage rate by >20-fold. Dynamic microtubules nucleated by seeds containing extra A-lattice seams have growth rates similar to microtubules nucleated by B-lattice seeds, yet have increased catastrophe frequencies at both ends. Furthermore, binding B-lattice GDP microtubules to a rigor kinesin surface stabilizes them against shrinkage, whereas microtubules with extra A-lattice seams are stabilized only slightly. Our data suggest that introducing extra A-lattice seams into dynamic microtubules destabilizes them by destabilizing their GTP caps. On this basis, we propose that the single A-lattice seam of natural B-lattice MTs may act as a trigger point, and potentially a regulation point, for catastrophe.

  14. Ectopic A-lattice seams destabilize microtubules

    PubMed Central

    Katsuki, Miho; Drummond, Douglas R.; Cross, Robert A.

    2014-01-01

    Natural microtubules typically include one A-lattice seam within an otherwise helically symmetric B-lattice tube. It is currently unclear how A-lattice seams influence microtubule dynamic instability. Here we find that including extra A-lattice seams in GMPCPP microtubules, structural analogues of the GTP caps of dynamic microtubules, destabilizes them, enhancing their median shrinkage rate by >20-fold. Dynamic microtubules nucleated by seeds containing extra A-lattice seams have growth rates similar to microtubules nucleated by B-lattice seeds, yet have increased catastrophe frequencies at both ends. Furthermore, binding B-lattice GDP microtubules to a rigor kinesin surface stabilizes them against shrinkage, whereas microtubules with extra A-lattice seams are stabilized only slightly. Our data suggest that introducing extra A-lattice seams into dynamic microtubules destabilizes them by destabilizing their GTP caps. On this basis, we propose that the single A-lattice seam of natural B-lattice MTs may act as a trigger point, and potentially a regulation point, for catastrophe. PMID:24463734

  15. Applying NASA's explosive seam welding

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.

    1991-01-01

    The status of an explosive seam welding process, which was developed and evaluated for a wide range of metal joining opportunities, is summarized. The process employs very small quantities of explosive in a ribbon configuration to accelerate a long-length, narrow area of sheet stock into a high-velocity, angular impact against a second sheet. At impact, the oxide films of both surface are broken up and ejected by the closing angle to allow atoms to bond through the sharing of valence electrons. This cold-working process produces joints having parent metal properties, allowing a variety of joints to be fabricated that achieve full strength of the metals employed. Successful joining was accomplished in all aluminum alloys, a wide variety of iron and steel alloys, copper, brass, titanium, tantalum, zirconium, niobium, telerium, and columbium. Safety issues were addressed and are as manageable as many currently accepted joining processes.

  16. Automated Solvent Seaming of Large Polyimide Membranes

    NASA Technical Reports Server (NTRS)

    Rood, Robert; Moore, James D.; Talley, Chris; Gierow, Paul A.

    2006-01-01

    A solvent-based welding process enables the joining of precise, cast polyimide membranes at their edges to form larger precise membranes. The process creates a homogeneous, optical-quality seam between abutting membranes, with no overlap and with only a very localized area of figure disturbance. The seam retains 90 percent of the strength of the parent material. The process was developed for original use in the fabrication of wide-aperture membrane optics, with areal densities of less than 1 kg/m2, for lightweight telescopes, solar concentrators, antennas, and the like to be deployed in outer space. The process is just as well applicable to the fabrication of large precise polyimide membranes for flat or inflatable solar concentrators and antenna reflectors for terrestrial applications. The process is applicable to cast membranes made of CP1 (or equivalent) polyimide. The process begins with the precise fitting together and fixturing of two membrane segments. The seam is formed by applying a metered amount of a doped solution of the same polyimide along the abutting edges of the membrane segments. After the solution has been applied, the fixtured films are allowed to dry and are then cured by convective heating. The weld material is the same as the parent material, so that what is formed is a homogeneous, strong joint that is almost indistinguishable from the parent material. The success of the process is highly dependent on formulation of the seaming solution from the correct proportion of the polyimide in a suitable solvent. In addition, the formation of reliable seams depends on the deposition of a precise amount of the seaming solution along the seam line. To ensure the required precision, deposition is performed by use of an automated apparatus comprising a modified commercially available, large-format, ink-jet print head on an automated positioning table. The printing head jets the seaming solution into the seam area at a rate controlled in coordination with

  17. Testing Seam Concepts for Advanced Multilayer Insulation

    NASA Technical Reports Server (NTRS)

    Chato, D. J.; Johnson, W. L.; Alberts, Samantha J.

    2017-01-01

    Multilayer insulation (MLI) is considered the state of the art insulation for cryogenic propellant tanks in the space environment. MLI traditionally consists of multiple layers of metalized films separated by low conductivity spacers. In order to better understand some of the details within MLI design and construction, GRC has been investigating the heat loads caused by multiple types of seams. To date testing has been completed with 20 layer and 50 layer blankets. Although a truly seamless blanket is not practical, a blanket lay-up where each individual layer was overlapped and tapped together was used as a baseline for the other seams tests. Other seams concepts tested included: an overlap where the complete blanket was overlapped on top of itself; a butt joint were the blankets were just trimmed and butted up against each other, and a staggered butt joint where the seam in the out layers is offset from the seam in the inner layers. Measured performance is based on a preliminary analysis of rod calibration tests conducted prior to the start of seams testing. Baseline performance for the 50 layer blanket showed a measured heat load of 0.46 Watts with a degradation to about 0.47 Watts in the seamed blankets. Baseline performance for the 20 layer blanket showed a measured heat load of 0.57 Watts. Heat loads for the seamed tests are still begin analyzed. So far analysis work has suggested the need for corrections due to heat loads from both the heater leads and the instrumentation wires. A careful re-examination of the calibration test results with these factors accounted for is also underway. This presentation will discuss the theory of seams in MLI, our test results to date, and the uncertainties in our measurements.

  18. Weld repair method for aluminum lithium seam

    NASA Technical Reports Server (NTRS)

    McGee, William Floyd (Inventor); Rybicki, Daniel John (Inventor)

    1998-01-01

    Aluminum-lithium plates are butt-welded by juxtaposing the plates and making a preliminary weld from the rear or root side of the seam. An initial weld is then made from the face side of the seam, which may cause a defect in the root portion. A full-size X-ray is made and overlain over the seam to identify the defects. The defect is removed from the root side, and rewelded. Material is then removed from the face side, and the cavity is rewelded. The procedure repeats, alternating from the root side to the face side, until the weld is sound.

  19. 3D Discrete element approach to the problem on abutment pressure in a gently dipping coal seam

    NASA Astrophysics Data System (ADS)

    Klishin, S. V.; Revuzhenko, A. F.

    2017-09-01

    Using the discrete element method, the authors have carried out 3D implementation of the problem on strength loss in surrounding rock mass in the vicinity of a production heading and on abutment pressure in a gently dripping coal seam. The calculation of forces at the contacts between particles accounts for friction, rolling resistance and viscosity. Between discrete particles modeling coal seam, surrounding rock mass and broken rocks, an elastic connecting element is introduced to allow simulating coherent materials. The paper presents the kinematic patterns of rock mass deformation, stresses in particles and the graph of the abutment pressure behavior in the coal seam.

  20. Finding a niche for seam cells?

    PubMed Central

    Brabin, Charles; Woollard, Alison

    2012-01-01

    The C. elegans neuroectodermal seam cells provide a tractable and well-established model for studying the stem cell mode of division, due to the reiterative asymmetric divisions occurring during larval development. They are, however, not generally considered to be ‘true’ stem cells, owing to their eventual terminal differentiation and the lack of a defined stem cell niche—a microenvironment that promotes the proliferation and prevents the differentiation of the stem cells that reside within. Here, we discuss the concept of the niche in relation to the seam, with reference to our recent findings suggesting that the stem-like properties of the seam cells are maintained at least in part through protection from differentiation signals emanating from the surrounding hypodermal syncytium. Determining the applicability of the niche concept will require definition of these signals and will have important implications for the status of seam cells in the context of stem cell biology. PMID:24058832

  1. Luminescence based series resistance mapping of III-V multijunction solar cells

    NASA Astrophysics Data System (ADS)

    Nesswetter, Helmut; Dyck, Wilhelm; Lugli, Paolo; Bett, Andreas W.; Zimmermann, Claus G.

    2013-11-01

    A method to measure the series resistance of Ga0.5In0.5P/Ga(In)As/Ge triple-junction solar cells spatially resolved is developed, based on luminescence imaging. With the help of network simulations, the dependence of the local series resistance on the external subcell illumination intensities and biasing voltage is predicted and the optimum measurement conditions are clarified. Experimentally, specially prepared test cells with partially irradiated areas are used to verify the capabilities of the method. It is shown that the method is not sensitive to variations of the dark I-V parameters of the subcells.

  2. Process for reducing series resistance of solar cell metal contact systems with a soldering flux etchant

    SciTech Connect

    Coyle, R.T.; Barrett, J.M.

    1984-10-09

    Disclosed is a process for substantially reducing the series resistance of a solar cell having a thick film metal contact assembly thereon while simultaneously removing oxide coatings from the surface of the assembly prior to applying solder therewith. The process includes applying a flux to the contact assembly and heating the cell for a period of time sufficient to substantially remove the series resistance associated with the assembly by etching the assembly with the flux while simultaneously removing metal oxides from said surface of said assembly.

  3. Luminescence based series resistance mapping of III-V multijunction solar cells

    SciTech Connect

    Nesswetter, Helmut; Dyck, Wilhelm; Lugli, Paolo; Bett, Andreas W.; Zimmermann, Claus G.

    2013-11-21

    A method to measure the series resistance of Ga{sub 0.5}In{sub 0.5}P/Ga(In)As/Ge triple-junction solar cells spatially resolved is developed, based on luminescence imaging. With the help of network simulations, the dependence of the local series resistance on the external subcell illumination intensities and biasing voltage is predicted and the optimum measurement conditions are clarified. Experimentally, specially prepared test cells with partially irradiated areas are used to verify the capabilities of the method. It is shown that the method is not sensitive to variations of the dark I–V parameters of the subcells.

  4. Process for reducing series resistance of solar cell metal contact systems with a soldering flux etchant

    DOEpatents

    Coyle, R. T.; Barrett, Joy M.

    1984-01-01

    Disclosed is a process for substantially reducing the series resistance of a solar cell having a thick film metal contact assembly thereon while simultaneously removing oxide coatings from the surface of the assembly prior to applying solder therewith. The process includes applying a flux to the contact assembly and heating the cell for a period of time sufficient to substantially remove the series resistance associated with the assembly by etching the assembly with the flux while simultaneously removing metal oxides from said surface of said assembly.

  5. Technology and means of a coal seam interval hydraulic fracturing for the seam degassing intensification

    NASA Astrophysics Data System (ADS)

    Klishin, VI; Opruk, GY; Tatsienko, AL

    2017-02-01

    Interval hydraulic fracturing use for the seam degassing intensification actuality is explained. The known methods of degassing are reviewed. Technological scheme of the interval coal seam hydraulic fracturing implementation is worked out. The equipment to fulfill degassing intensification measures is suggested.

  6. Aluminized film, seam sealing tests and observations. Final report

    SciTech Connect

    Not Available

    1994-06-16

    The purpose of this work was to investigate various seam sealing techniques, reinforcing methods, fitting installations, seam tolerances and geometric configurations pertinent to an aluminized plastic laminate. The program seeks a successful fabricating method for producing low-diffusion, cylindrical, spar liners to contain pressurized GH{sub 2} and GO{sub 2}. The test plan included: (1) seaming techniques on metallized Mylar film; (2) ``double patches`` for end fittings; (3) stainless steel bulkhead fitting assembly with seals; (4) minimum run tolerance on linear shear seam; (5) peel seam vs. inverted seal seam fabrication.

  7. Bi2Te3-xSex series studied by resistivity and thermopower

    NASA Astrophysics Data System (ADS)

    Akrap, Ana; Ubaldini, Alberto; Giannini, Enrico; Forró, László

    2014-09-01

    We study the detailed temperature and composition dependence of the resistivity, \\rho(T) , and thermopower, S(T), for a series of layered bismuth chalcogenides Bi2Te3-xSex, and report the stoichiometry dependence of the optical band gap. In the resistivity of the most compensated member, Bi2Te2.1Se0.9, we find a low-temperature plateau whose onset temperature correlates with the high-temperature activation energy. For the whole series S(T) can be described by a simple model for an extrinsic semiconductor. By substituting Se for Te, the Fermi level is tuned from the valence band into the conduction band. The maximum values of S(T), bulk band gap as well the activation energy in the resistivity are found for x \\approx 0.9 .

  8. Investigations about series resistance of MOVPE grown GaN laser structures

    NASA Astrophysics Data System (ADS)

    Scholz, F.; Moutchnik, G.; Dumitru, V.; Härle, R.; Schweizer, H.

    2003-02-01

    In order to reduce the total series resistance of an AlGaInN laser structure, we have exchanged the GaN:Mg contact layer normally covering a laser structure by GaInN:Mg and have investigated the influence of several growth conditions on its electrical properties. We found a significant decrease of the series resistance for a GaInN layer grown at 800°C with hydrogen as carrier gas which results, at lower current densities, in a voltage drop of at least 2 V compared to GaN contact layers. Our studies show that not only the changed growth conditions, but indeed the In content plays a major role for these improvements, although it is only about 2%. Laser structures grown on SiC wafers show minimum total differential resistivities below 1.5×10 -4 Ω cm 2.

  9. Seams near seams: the Jahn-Teller effect in the 1E" state of N3+.

    PubMed

    Dillon, Joseph J; Yarkony, David R

    2007-03-28

    The (1)E(") electronic state of cyclic N(3) (+) arising from the singly excited electron configuration e('3)e(") is studied using multireference configuration interaction wave functions and a quadratic Jahn-Teller Hamiltonian determined from those calculations. It is shown that these two states have both a symmetry-required seam of conical intersections at D(3h) geometries and three proximal symmetry equivalent C(2v) seams, located on a circle with radius rho(0) from the D(3h) intersection. rho(0), a function of Q(s), the breathing mode, is quite small but only attains a value of zero at Q(s) (crit)=1.252 A, resulting in a confluence or intersection node of the three C(2v) seams with the D(3h) seam. At this point only, g= parallelg(Q(s)) parallel, the norm of half the energy difference gradient, the linear Jahn-Teller term, vanishes and the intersection is of the Renner-Teller type. The close proximity of the previously unreported C(2v) seams to the D(3h) seam over the range of Q(s) considered is a consequence of the small values of g, compared to the quadratic Jahn-Teller term. The present analysis has important implications in the study of Jahn-Teller effects in ring systems and provides insight into a recent report that characterized this D(3h) seam as a Renner-Teller or glancing intersection.

  10. Algorithm For Simplified Robotic Tracking Of Weld Seams

    NASA Technical Reports Server (NTRS)

    Gutow, David A.; Paternoster, Vincent Y.

    1992-01-01

    Algorithm computes small cross-seam corrections to programmed path of welding robot. Intended for use with add-on vision system loosely coupled to robot, transmitting small amount of information about weld seam ahead of torch. Position of welding torch in reference frame of moving window estimated on basis of data on weld seam and speed of torch. Does not need data on position of torch, and does not transform data on seam to another reference frame.

  11. Initial experience of bedaquiline use in a series of drug-resistant tuberculosis patients from India.

    PubMed

    Udwadia, Z F; Amale, R A; Mullerpattan, J B

    2014-11-01

    Drug-resistant tuberculosis (DR-TB) is a major problem both in India and worldwide. Newer drugs such as TMC-207 (bedaquiline) may have an important role to play in making up an effective drug regimen in such cases. There have been a few reports of bedaquiline use in a non-trial setting from Europe. Our series of five patients is the first series of DR-TB patients from India to receive bedaquiline. All five patients showed striking improvement, with microbiological conversion and an absence of notable adverse effects (e.g., prolonged QTcF), indicating the potential impact of this drug in such a population.

  12. Testicular resistive index determined by Doppler ultrasonography in men with spinal cord injury - a case series.

    PubMed

    Krebs, J; Göcking, K; Pannek, J

    2015-09-01

    In this case series, the testicular resistive index was determined in men with spinal cord injury. In ten men participating in our fertility programme, the peak systolic and end-diastolic velocity of centripetal testicular arteries was measured in triplicates by Doppler ultrasonography to calculate the testicular resistive index. Furthermore, the right and left testicular volume was determined by ultrasonography, blood samples were obtained for hormonal evaluation, and sperm analysis was performed according to the WHO guidelines. The median testicular resistive index measured 0.69 and was significantly (P < 0.001) greater than the reported cut-off value of 0.6. The spermiograms were characterised by normal sperm count but decreased sperm motility and plasma membrane integrity. The median right and left testicular volume was significantly (P < 0.01) smaller compared to the volumes measured in able-bodied adult males without scrotal pathology and measured 8.4 ml and 7.2 ml respectively. There was a significant (P = 0.005) correlation (rs  = 0.81) between testicular resistive index and sperm concentration. However, no correlations were observed between testicular resistive index and other variables. The testicular resistive index in men with spinal cord injury was significantly greater than 0.6. Measuring the testicular resistive index may represent a useful additional parameter in the assessment of infertility in spinal cord-injured men.

  13. CO2 Sequestration in Unmineable Coal Seams: Potential Environmental Impacts

    SciTech Connect

    Hedges, S.W.; Soong, Yee; McCarthy Jones, J.R.; Harrison, D.K.; Irdi, G.A.; Frommell, E.A.; Dilmore, R.M.; Pique, P.J.; Brown, T.D

    2005-09-01

    An initial investigation into the potential environmental impacts of CO2 sequestration in unmineable coal seams has been conducted, focusing on changes in the produced water during enhanced coalbed methane (ECBM) production using a CO2 injection process (CO2-ECBM). Two coals have been used in this study, the medium volatile bituminous Upper Freeport coal (APCS 1) of the Argonne Premium Coal Samples series, and an as-mined Pittsburgh #8 coal, which is a high volatile bituminous coal. Coal samples were reacted with either synthetic produced water or field collected produced water and gaseous carbon dioxide at 40 οC and 50 bar to evaluate the potential for mobilizing toxic metals during CO2-ECBM/sequestration. Microscopic and x-ray diffraction analysis of the post-reaction coal samples clearly show evidence of chemical reaction, and chemical analysis of the produced water shows substantial changes in composition. These results suggest that changes to the produced water chemistry and the potential for mobilizing toxic trace elements from coalbeds are important factors to be considered when evaluating deep, unmineable coal seams for CO2 sequestration.

  14. Comparative study of NSB and UTB SOI MOSFETs characteristics by extraction of series resistance

    NASA Astrophysics Data System (ADS)

    Karsenty, A.; Chelly, A.

    2014-01-01

    The electrical characteristics of two kinds of n-type SOI-MOSFETs are analyzed and compared in order to build a consistent model. The first kind is an Ultra-Thin Body (UTB) device for which the channel thickness is equal to the initial SOI wafer thickness value (here 46 nm). The second kind is what we refer to Nano-Scale Body (NSB) device for which the initial SOI channel is thinned down to 1.6 nm using a recessed-gate process. The drain current values were found surprisingly different by three orders of magnitude. Such a huge contrast was not found coherent with the literature, reporting the decrease of the electron mobility with the channel thickness. We interpret our result by the probable influence of an extreme drain-to-source series resistance rather than by vanishing carrier mobility. The interpretation is sustained experimentally by the Rm-L and C-V methods. By integrating a gate-voltage dependence to the series resistance, the linear and saturation regions of the output characteristics of the NSB can be analytically derived from the UTB ones. This simple modeling approach may be useful to interpret anomalous electrical behavior of other nano-devices in which series resistance is of a great concern.

  15. Accurate expressions for solar cell fill factors including series and shunt resistances

    NASA Astrophysics Data System (ADS)

    Green, Martin A.

    2016-02-01

    Together with open-circuit voltage and short-circuit current, fill factor is a key solar cell parameter. In their classic paper on limiting efficiency, Shockley and Queisser first investigated this factor's analytical properties showing, for ideal cells, it could be expressed implicitly in terms of the maximum power point voltage. Subsequently, fill factors usually have been calculated iteratively from such implicit expressions or from analytical approximations. In the absence of detrimental series and shunt resistances, analytical fill factor expressions have recently been published in terms of the Lambert W function available in most mathematical computing software. Using a recently identified perturbative relationship, exact expressions in terms of this function are derived in technically interesting cases when both series and shunt resistances are present but have limited impact, allowing a better understanding of their effect individually and in combination. Approximate expressions for arbitrary shunt and series resistances are then deduced, which are significantly more accurate than any previously published. A method based on the insights developed is also reported for deducing one-diode fits to experimental data.

  16. Study on welded seam recognition using circular laser vision sensor

    NASA Astrophysics Data System (ADS)

    Xu, Peiquan; Tang, Xinhua; Na, Ri; Yao, Shun

    2007-06-01

    A novel visual robotic arc welding system based on circular laser vision sensor is developed. After image de-noising, image segmentation, and image thinning, the relation of depth value of workpiece and off-axis angle 'gamma', three-dimensional (3D) calculation, and seam tracking experiments are carried out. Finally, the error for seam tracking system is analyzed. The results show that 1) 3D information can be obtained using the proposed visual robotic arc welding system and the real-time seam tracking is realized; 2) the seam tracking error is small enough for gas tungsten arc welding (GTAW) process, and this system can be used for seam location and seam tracking or seam finder.

  17. Exemplary geophysical investigations on coal seam fires in Northern China

    NASA Astrophysics Data System (ADS)

    Lambrecht, A.; Meyer, U.; Rüter, H.; Gundelach, V.; Lindner, H.; Schaumann, G.; Schlömer, S.; Guangliang, L.; Bing, K.; Jianjun, W.

    2009-04-01

    and a 40 MHz antenna was used to get maximum penetration depth. The heat and fluid transport included in the burning process presumably changes the permittivity of the rock which affects the attenuation of the radar signal and reduces the conductivity of the rock. This enables GPR measurements to discriminate burning zones from intact zones. The border line of the fire zone in the southern and the northern part of the investigated fire zone could be found. At the burning areas it was possible to discriminate different layers in the subsurface. Anywhere else the soil was highly conductive and full of clefts. The clefts were visible in the radar data only close to the surface. Magnetic was measured area-wide with a QuickTracker (GSM-19T) console from GEM Systems over different fire zones and shows positive anomalies in the coal fire area. The stratigraphy in the area shows no magnetic rocks above the coal seam, which leads to the interpretation that the positive magnetic anomalies are caused through the thermal induced magnetism of the stones lying above the coal seam. Over 100 rock samples (Sandstone, Coal and clinkers) has been taken for in-situ determination of the magnetic susceptibility. The positive magnetic anomaly is distinguished by the high magnetisation of the clinkers and therefore important for the detection of coal fires. TEM measurements were performed along profile lines across the fire zone or at single localities selected in the actual area. The spacing of the TEM sites was adapted to the terrain. Profiles crossing the area where the hot burning zone can be found, the TEM curves change their shape clearly. The vertical resistivity section shows a highly conductive layer which seems to coincides with the thermally affected coal seam. Temperature variations are most extreme at the surface of the soil. The peak temperature below the surface occurs about 2 hours after the maximum ambient air temperatures are attained. Temperature measurements in the gas

  18. Real-Time Series Resistance Monitoring in PV Systems Without the Need for I-V Curves

    SciTech Connect

    Deceglie, Michael G.; Silverman, Timothy J.; Marion, Bill; Kurtz, Sarah R.

    2015-10-01

    We apply the physical principles of a familiar method, suns-Voc, to a new application: the real-time detection of series resistance changes in modules and systems operating outside. The real-time series resistance (RTSR) method that we describe avoids the need for collecting I-V curves or constructing full series resistance-free I-V curves. RTSR is most readily deployable at the module level on microinverters or module-integrated electronics, but it can also be extended to full strings. We found that automated detection of series resistance increases can provide early warnings of some of the most common reliability issues, which also pose fire risks, including broken ribbons, broken solder bonds, and contact problems in the junction or combiner box. We also describe the method in detail and describe a sample application to data collected from modules operating in the field.

  19. Automated IR-weld seam control

    NASA Astrophysics Data System (ADS)

    Balle, Michel

    1990-03-01

    In 1975 the concept of visualizing, measuring and studying the thermal condition of welded seams was investigated by a laboratory of the French ministry of defense (at the request of a metal constructor). Gilbert Gaussorgues, the founding father of the company HGH was at the time in charge of the infrared laboratory in question, a department of the general administration of Armament in Toulon, France. His idea was to apply military IR-Technology to above mentioned welding application. Having developed a prototype, tests readily confirmed the validity of using IR-emission from the weld seam close to the actual moment of welding as an indicator of the quality of the fmal assembly. Nearly ten years later, in 1984, HGH decided, due to an increasing demand, to develop above preliminary tests to a complete product/application package designed specifically for welding process-control. The inspection oftubing and of the integrity welds of barrels with hazardous content, were the first applications.

  20. A versatile new mineralized bone stain for simultaneous assessment of tetracycline and osteoid seams.

    PubMed

    Villanueva, A R; Lundin, K D

    1989-05-01

    A versatile mineralized bone stain (MIBS) for demonstrating osteoid seams and tetracycline fluorescence simultaneously in thin or thick undecalcified sections has been developed. Bone specimens are fixed in 70% ethanol, but 10% buffered formalin is permissible. Depending upon one's preference, these specimens can be left unstained or be prestained before plastic embedding. Osteoid seams are stained green to jade green, or light to dark purple. Mineralized bone matrix is unstained or green. Osteoblast and osteoclast nuclei are light to dark purple, cytoplasm varies from slightly gray to pink. The identification of osteoid seams by this method agrees closely with identification by in vivo tetracycline uptake using the same section from the same biopsy. The method demonstrates halo volumes, an abnormal, lacunar, low density bone around viable osteocytes in purple. This phenomenon is commonly seen in vitamin D-resistant rickets, fluorosis, renal osteodystrophy, hyperparathyroidism, and is sometimes seen in fluoride treated osteoporotic patients. In osteomalacic bone, most osteoid seams are irregularly stained as indicated by the presence of unmineralized osteoid between mineralized lamellae. The method has been used effectively in staining new bone formation in hydroxyapatite implants and bone grafts. Old, unstained, plastic embedded undecalcified sections are stained as well as fresh sections after removal of the coverslip. This stain also promises to be valuable in the study of different metabolic bone diseases from the point of view of remodeling, histomorphometry, and pathology.

  1. Methods and costs of thin-seam mining. Final report, 25 September 1977-24 January 1979. [Thin seam in association with a thick seam

    SciTech Connect

    Finch, T.E.; Fidler, E.L.

    1981-02-01

    This report defines the state of the art (circa 1978) in removing thin coal seams associated with vastly thicker seams found in the surface coal mines of the western United States. New techniques are evaluated and an innovative method and machine is proposed. Western states resource recovery regulations are addressed and representative mining operations are examined. Thin seam recovery is investigated through its effect on (1) overburden removal, (2) conventional seam extraction methods, and (3) innovative techniques. Equations and graphs are used to accommodate the variable stratigraphic positions in the mining sequence on which thin seams occur. Industrial concern and agency regulations provided the impetus for this study of total resource recovery. The results are a compendium of thin seam removal methods and costs. The work explains how the mining industry recovers thin coal seams in western surface mines where extremely thick seams naturally hold the most attention. It explains what new developments imply and where to look for new improvements and their probable adaptability.

  2. Investigation of subsidence event over multiple seam mining area

    SciTech Connect

    Kohli, K.K.

    1999-07-01

    An investigation was performed to determine the sequence of events which caused the 1987 surface subsidence and related damage to several homes in Walker County, Alabama, USA. Surface affects compared to mine maps indicated the subsidence to be mine related. However, two coal seams had been worked under this area. The upper seam, the American seam, ranged from 250 to 280 feet beneath the surface in the area in question. It was mined-out before 1955 by room-and-pillar method leaving in place narrow-long pillars to support the overburden strata, and abandoned in 1955. The lower seam, the Mary Lee seam, ranged from 650 to 700 feet beneath the surface. The Mary Lee seam had been abandoned in 1966 and subsequently became flooded. The dewatering of the Mary Lee seam workings in 1985 caused the submerged pillars to be exposed to the atmosphere. Due to multiple seam mining and the fact that workings had been inundated then dewatered, a subsurface investigation ensued to determine the sequence and ultimate cause of surface subsidence. Core sample tests with fracture analysis in conjunction with down-the-hole TV camera inspections provided necessary information to determine that the subsidence started in the lower seam and progressed through the upper coal seam to the surface. Evidence from the investigation program established that dewatering of the lower seam workings caused the marginally stable support pillars and the roof to collapse. This failure triggered additional subsidence in the upper seam which broadened the area of influence at the surface.

  3. On the dust-equivalent series resistance of a photovoltaic concentrator

    NASA Astrophysics Data System (ADS)

    Zakzouk, A. K. M.

    1984-02-01

    A new concept for treating the effects of dust on the electrical performance of photovoltaic concentrators is presented in the paper. The dust concentration in the atmospheric air around the concentrator is measured continuously during the test period. The rate of dust accumulation on the concentrator surface is determined. The concentrator performance degradation, as a result of dust accumulation, is related to the amount of dust accumulated per unit area of the collector surface (in g/sq m) rather than the exposure time. It has been shown that major reductions in the short-circuit current and the efficiency are observed for dust accumulations up to 5.4 g/sq m. The accumulation of dust on the photovoltaic concentrator causes a successively larger 'rounding' of the I/V characteristic at constant incident direct normal radiation intensity and constant cell temperature. This effect is equivalent to an increase in the internal series resistance of the concentrator. This dust-equivalent series resistance increases with increasing dust accumulation.

  4. Width Criterion For Weld-Seam-Tracking Data

    NASA Technical Reports Server (NTRS)

    Lincir, Mark R.

    1993-01-01

    Image-processing algorithm in "through-torch-vision" (T3V) system developed to guide gas/tungsten arc welding robot along weld seam modified, according to proposal, reducing incidence of inaccurate tracking of weld seam. Developmental system intended to provide closed-loop control of motion of welding robot along weld seam on basis of lines in T3V image identified by use of image-processing algorithm and assumed to coincide with edges of weld seam. Use of width criterion prevents tracking of many false pairs of lines, with consequent decrease in incidence of inaccurate tracking and increase in confidence in weld-tracking capability of robotic welding system.

  5. Beam/seam alignment control for electron beam welding

    DOEpatents

    Burkhardt, Jr., James H.; Henry, J. James; Davenport, Clyde M.

    1980-01-01

    This invention relates to a dynamic beam/seam alignment control system for electron beam welds utilizing video apparatus. The system includes automatic control of workpiece illumination, near infrared illumination of the workpiece to limit the range of illumination and camera sensitivity adjustment, curve fitting of seam position data to obtain an accurate measure of beam/seam alignment, and automatic beam detection and calculation of the threshold beam level from the peak beam level of the preceding video line to locate the beam or seam edges.

  6. Successful Rituximab Therapy in Steroid-Resistant, Cryptogenic Organizing Pneumonia: A Case Series.

    PubMed

    Shitenberg, Dorit; Fruchter, Oren; Fridel, Ludmila; Kramer, Mordechai R

    2015-01-01

    Cryptogenic organizing pneumonia (COP) is an interstitial lung disease that is usually responsive to corticosteroid treatment. The treatment of COP has not been studied in randomized controlled trials; thus, treatment decisions are based on practice guidelines. We herein present, for the first time, 4 cases of patients with biopsy-proven COP who did not respond to corticosteroids but benefited from rituximab therapy. This report consists of a retrospective case series of patients who experienced steroid-resistant, biopsy-proven COP. Patients included in this case series suffered from acute or chronic COP and did not respond to corticosteroid treatment for a few weeks to months but later responded to rituximab. In a series of 4 patients, 1 patient had a complete radiological and clinical response after rituximab therapy, and the steroids could be gradually tapered. Three patients had a chronic course but had been able to lower steroid dosage or even discontinue the drug after being treated with rituximab. Since 40% of the patients with COP do not respond to or stay dependent on steroids, we think that even the ability to lower the steroid dosage by using rituximab as a steroid-sparing agent with a good safety profile is worth the effort. However, further studies are warranted. © 2015 S. Karger AG, Basel.

  7. Practical small-scale explosive seam welding

    NASA Technical Reports Server (NTRS)

    Bement, L. J.

    1983-01-01

    Joining principles and variables, types of joints, capabilities, and current and potential applications are described for an explosive seam welding process developed at NASA Langley Research Center. Variable small quantities of RDX explosive in a ribbon configuration are used to create narrow (less than 0.5 inch), long length, uniform, hermetrically sealed joints that exhibit parent metal properties in a wide variety of metals, alloys, and combinations. The first major all application of the process is the repair of four nuclear reactors in Canada. Potential applications include pipelines, sealing of vessels, and assembly of large space structures.

  8. Seam bonding of graphite reinforced composite panels

    NASA Technical Reports Server (NTRS)

    Buckley, John D.; Fox, Robert L.; Tyeryar, James R.

    1986-01-01

    An account is given of the design features and operating characteristics of a method for the joining of composite parts, at a rate of 2 to 6 inches/min, in which the heating process responsible for adhesive flow at 800 F is focused upon the overlapped seam. The heating element is a self-tuning solid state power oscillator whose ferrite's toroid geometry generates a uniform, concentrated magnetic flux in the component to be bonded. Specimens cut from graphite/epoxy panels bonded with epoxy-phenolic adhesive by this process have exhibited average lap-shear strengths of the order of 3400 lbs/sq in.

  9. Investigation of Standing Seam Metal Roofing.

    DTIC Science & Technology

    1986-06-01

    I I 1 1.JI 25 111 .4 111. MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDAROS 1963 A US Army Corps TECHNICAL REPORT M-86/10 of Engineers June...Cont’d) Number Page 47 Ridge Cap With Profile Closures-Example 2 49 48 Ridge Cap With Profile Closures-Example 3 50 49 Circular Ridge Vent 51 50 EPDM ...Example 2 56 57 EPDM Flashing at Headwall 56 58 Metal Valley Flashing-Example 1 57 59 Metal Valley Flashing-Example 2 57 60 Exposed-Fastener Seam Detal

  10. Visco-resistive length scale in flux pile-up and series solutions for magnetic reconnection

    NASA Astrophysics Data System (ADS)

    McMahon, Liam C.

    2017-05-01

    Current sheets play a crucial role in determining the physics of magnetic reconnection in solar flares. We investigate the structure of a reconnecting visco-resistive (VR) current sheet in two dimensional steady incompressible MHD. We review a number of solutions that demonstrate that several distinct potential length scalings may emerge for VR reconnection. We find a criterion for the presence of a VR length scale in magnetic flux pile-up solutions and we utilise a series expansion technique in order to describe the inner solution of a VR current sheet. We posit that a VR length scale is the fundamental length scale of a VR current sheet and its absence is purely a feature of a limited class of particular solutions for the inflow velocity profile.

  11. The use of levomepromazine in Hyperemesis Gravidarum resistant to drug therapy--a case series.

    PubMed

    Heazell, Alexander E P; Langford, Nigel; Judge, Jatinder K; Heazell, Martin A; Downey, Gabrielle P

    2005-01-01

    Hyperemesis Gravidarum (HG) is a potentially serious complication of early pregnancy, which may rarely be severe enough to warrant termination of pregnancy. HG requires prompt treatment with intravenous fluids, thiamine supplementation and appropriate anti-emetic therapy. Anti-histamines such as promethazine are favoured as first-line agents, with prochlorperazine being used as a second-line drug. However, there is no clear data as to the most appropriate drug if these are ineffective. A case series of six women who presented with HG resistant to drug treatment is described. In these cases, levomepromazine 6.25mg tds was used to control HG. Five pregnancies progressed leading to live born infants with no evidence of congenital anomaly. One pregnancy resulted in an intra-uterine death with no external or ultrasound evidence of congenital anomaly. The role of phenothiazines in the pharmacological management of HG is discussed.

  12. Analytic expression for the Fowler-Nordheim V- I characteristic including the series resistance effect

    NASA Astrophysics Data System (ADS)

    Miranda, E.; Palumbo, F.

    2011-07-01

    It is shown in this communication that the Fowler-Nordheim (FN) tunneling expression for the current-voltage ( I- V) characteristic can be analytically inverted so that an exact expression for the voltage-current ( V- I) characteristic can be obtained. The solution of the resulting implicit equation is found using the Lambert W function, i.e. the solution of the transcendental equation we w = x. The reported expressions are supported by experimental I- V curves measured in thin (≈5 nm) SiO 2 films in MOS capacitors. The analysis includes the case of a tunneling oxide with a large series resistance. For practical purposes, a closed-form expression for W based on a Padé-type approximation is also provided.

  13. Effects of equivalent series resistance on the noise mitigation performance of piezoelectric shunt damping

    NASA Astrophysics Data System (ADS)

    Lai, Szu Cheng; Sharifzadeh Mirshekarloo, Meysam; Yao, Kui

    2017-05-01

    Piezoelectric shunt damping (PSD) utilizes an electrically-shunted piezoelectric damper attached on a panel structure to suppress the transmission of acoustic noise. The paper develops an understanding on the effects of equivalent series resistance (ESR) of the piezoelectric damper in a PSD system on noise mitigation performance, and demonstrates that an increased ESR leads to a significant rise in the noise transmissibility due to reduction in the system’s mechanical damping. It is further demonstrated with experimental results that ESR effects can be compensated in the shunt circuit to significantly improve the noise mitigation performance. A theoretical electrical equivalent model of the PSD incorporating the ESR is established for quantitative analysis of ESR effects on noise mitigation.

  14. Filter properties of seam material from paved urban soils

    NASA Astrophysics Data System (ADS)

    Nehls, T.; Jozefaciuk, G.; Sokolowska, Z.; Hajnos, M.; Wessolek, G.

    2007-08-01

    We studied pavement seam material. This is the soil substrate in joints of pervious pavements in urban areas. It is mostly 1 cm thick and develops from the original seam filling by depositions of all kinds of urban residues, including anthropogenic organic substances. It was investigated, how this unique form of organic matter influences the filter properties of seam material and how the seam material influences heavy metal transport through the pavement. The seam material is characterised by a darker munsell colour, higher organic carbon content, higher surface areas, higher cation exchange capacities, but a lower fraction of high adsorption energy sites compared to the original seam filling. The deposited anthropogenic organic matter itself could be characterised as particulate and non-polar. Compared to natural soils, it has a small surface area and a low surface charge density resulting in a small cation exchange capacity of only 75 cmol(+) kg-1C. The seam material shows stronger sorption of Pb and Cd compared to the original construction sand. The retardation capacity of seam material towards Pb is similar, towards Cd it is much smaller compared to natural soils. The simulated long term displacement scenarios for a street in Berlin do not indicate an acute contamination risk for Pb. For Cd the infiltration from ponds can lead to a displacement of Cd during only one decade.

  15. TECHNIQUES FOR THE FABRICATION OF GEOMEMBRANE FILLED SEAMS

    EPA Science Inventory

    Geomembranes employed to overlay the excavation for landfills must be seamed together on-site at the landfill. To ensure the integrity of the containment system of the landfill, these sheets or blankets must be carefully seamed. Present methods in common use are: extrusion fil...

  16. 49 CFR 230.30 - Lap-joint seam boilers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Lap-joint seam boilers. 230.30 Section 230.30..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal...

  17. 49 CFR 230.30 - Lap-joint seam boilers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Lap-joint seam boilers. 230.30 Section 230.30..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal...

  18. 49 CFR 230.30 - Lap-joint seam boilers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Lap-joint seam boilers. 230.30 Section 230.30..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal...

  19. TECHNIQUES FOR THE FABRICATION OF GEOMEMBRANE FILLED SEAMS

    EPA Science Inventory

    Geomembranes employed to overlay the excavation for landfills must be seamed together on-site at the landfill. To ensure the integrity of the containment system of the landfill, these sheets or blankets must be carefully seamed. Present methods in common use are: extrusion fil...

  20. In-situ coal seam and overburden permeability characterization combining downhole flow meter and temperature logs.

    NASA Astrophysics Data System (ADS)

    Busse, Julia; Scheuermann, Alexander; Bringemeier, Detlef; Hossack, Alex; Li, Ling

    2016-06-01

    The planning and design of any coal mine development requires among others a thorough investigation of the geological, geotechnical and hydrogeological subsurface conditions. As part of a coal mine exploration program we conducted heat pulse vertical flow meter testing. The flow data were combined with absolute and differential temperature logging data to gain information about the hydraulic characteristics of two different coal seams and their over- and interburden. For the strata that were localised based on geophysical logging data including density, gamma ray and resistivity hydraulic properties were quantified. We demonstrate that the temperature log response complements the flow meter log response. A coupling of both methods is therefore recommended to get an insight into the hydraulic conditions in a coal seam and its overburden.

  1. Optimizatin Of Pulsed Nd:YAG Laser Parameters For Titanium Seam-Welding

    NASA Astrophysics Data System (ADS)

    Akman, E.; Canel, T.; Demir, A.; Sinmazcelik, T.

    2007-04-01

    Titanium alloys are the most advantageous metals for the medical and aerospace industry because of their light weight and excellent corrosion resistance. Several techniques were investigated to achieve reliable welds with optimal distortion for the fabrication components used in industry. Laser welding is the most important joining technique because of its precision, rapid processing. For pulse mode Nd:YAG laser; pulse shape, energy, duration, repetition rate and peak power are the most important parameters effects the weld quality. And also the combinations of these parameters are very important for pulsed laser seam-welding. In this study, an experimental work has been done to determine the pulsed laser seam-welding parameters for 3mm thick titanium alloys using the Lumonics JK760TR Nd:YAG pulsed laser.

  2. Influences Determining European Coal Seam Gas Deliverability

    NASA Astrophysics Data System (ADS)

    Clark, G.

    2009-04-01

    Technically the coal basins of Europe have generated significant Gas In Place figures that has historically generated investor's interest in the development of this potential coal seam gas (CSG) resource. In the early 1980's, a wave of international, principally American, companies arrived, established themselves, drilled and then left with a poor record of success and disappointed investors. Recently a second wave of investment started after 2002, with the smaller companies leading the charge but have the lesson been learned from the past failures? To select a CSG investment project the common European approach has been to: 1. Find an old mining region; 2. Look to see if it had a coal mine methane gas problem; 3. Look for the non-mined coal seams; and 4. Peg the land. This method is perhaps the reason why the history of CSG exploration in Europe is such a disappointment as generally the coal mining regions of Europe do not have commercial CSG reservoir attributes. As a result, investors and governments have lost confidence that CSG will be a commercial success in Europe. New European specific principles for the determination of commercial CSG prospects have had to be delineated that allow for the selection of coal basins that have a strong technical case for deliverability. This will result in the return of investor confidence.

  3. Detection for processing history of seam insertion and contrast enhancement

    NASA Astrophysics Data System (ADS)

    Li, Jianwei; Zhao, Yao; Ni, Rongrong

    2014-11-01

    With the development of manipulations techniques of digital images, digital image forensic technology is becoming more and more necessary. However, the determination of processing history of multi-operation is still a challenge problem. In this paper, we improve the traditional seam insertion algorithm, and propose corresponding detection method. Then an algorithm that focuses on detecting the processing history of seam insertion and contrast enhancement is proposed, which can be widely used in practical image forgery. Based on comprehensive analysis, we have discovered the inherent relationship between seam insertion and contrast enhancement. Different orders of processing make different impacts on images. By using the newly proposed algorithm, both contrast enhancement followed by seam insertion and seam insertion followed by contrast enhancement can be detected correctly. Plenty of experiments have been implemented to prove the accuracy.

  4. Method for gasification of deep, thin coal seams

    DOEpatents

    Gregg, David W.

    1982-01-01

    A method of gasification of coal in deep, thin seams by using controlled bending subsidence to confine gas flow to a region close to the unconsumed coal face. The injection point is moved sequentially around the perimeter of a coal removal area from a production well to sweep out the area to cause the controlled bending subsidence. The injection holes are drilled vertically into the coal seam through the overburden or horizontally into the seam from an exposed coal face. The method is particularly applicable to deep, thin seams found in the eastern United States and at abandoned strip mines where thin seams were surface mined into a hillside or down a modest dip until the overburden became too thick for further mining.

  5. Method for gasification of deep, thin coal seams. [DOE patent

    DOEpatents

    Gregg, D.W.

    1980-08-29

    A method of gasification of coal in deep, thin seams by using controlled bending subsidence to confine gas flow to a region close to the unconsumed coal face is given. The injection point is moved sequentially around the perimeter of a coal removal area from a production well to sweep out the area to cause the controlled bending subsidence. The injection holes are drilled vertically into the coal seam through the overburden or horizontally into the seam from an exposed coal face. The method is particularly applicable to deep, thin seams found in the eastern United States and at abandoned strip mines where thin seams were surface mined into a hillside or down a modest dip until the overburden became too thick for further mining.

  6. Real-time seam tracking for rocket thrust chamber manufacturing

    SciTech Connect

    Schmitt, D.J.; Novak, J.L.; Starr, G.P.; Maslakowski, J.E.

    1993-11-01

    A sensor-based control approach for real-time seam tracking of rocket thrust chamber assemblies has been developed to enable automation of a braze paste dispensing process. This approach utilizes a non-contact Multi-Axis Seam Tracking (MAST) sensor to track the seams. Thee MAST sensor measures capacitance variations between the sensor and the workpiece and produces four varying voltages which are read directly into the robot controller. A PID control algorithm which runs at the application program level has been designed based upon a simple dynamic model of the combined robot and sensor plant. The control algorithm acts on the incoming sensor signals in real-time to guide the robot motion along the seam path. Experiments demonstrate that seams can be tracked at 100 mm/sec within the accuracy required for braze paste dispensing.

  7. Cognitive-behaviour therapy for medication-resistant positive symptoms in early psychosis: a case series.

    PubMed

    Erickson, David H

    2010-08-01

    Cognitive-behaviour therapy (CBT) for psychosis reduces the severity of medication-resistant positive symptoms in chronic schizophrenia, but its efficacy for early psychosis outpatients with a similar profile has not been established. This paper describes an uncontrolled evaluation of CBT, added to medication and comprehensive care in an early psychosis program, in a group of stable outpatients. The sample was drawn from 24 consecutive referrals. Fourteen were eligible, i.e. had positive symptom(s) and had been on the same medication regime for 3 months. Patients received an average of 16 individual sessions with a senior psychologist. Symptom severity was assessed both by an independent rater, and by patient self-report. Eleven of 14 patients completed treatment. Both clinician and self-report post-treatment ratings of positive symptoms were significantly reduced following CBT. For positive symptom totals, effect sizes ranged from d = 1.0 to 1.3. Clinically significant changes were apparent in at least eight of 11 patients. While case-series studies have significant limitations, the large effect sizes described here suggest that CBT shows promise for effectiveness with early psychosis patients. A randomized trial is needed to establish both the effect size over and above a control condition, and the durability of gains of CBT for medication-resistant symptoms in early psychosis.

  8. Influence of patterning the TCO layer on the series resistance of thin film HIT solar cells

    NASA Astrophysics Data System (ADS)

    Champory, Romain; Mandorlo, Fabien; Seassal, Christian; Fave, Alain

    2017-01-01

    Thin HIT solar cells combine efficient surface passivation and high open circuit voltage leading to high conversion efficiencies. They require a TCO layer in order to ease carriers transfer to the top surface fingers. This Transparent Conductive Oxide layer induces parasitic absorption in the low wavelength range of the solar spectrum that limits the maximum short circuit current. In case of thin film HIT solar cells, the front surface is patterned in order to increase the effective life time of photons in the active material, and the TCO layer is often deposited with a conformal way leading to additional material on the sidewalls of the patterns. In this article, we propose an alternative scheme with a local etching of both the TCO and the front a-Si:H layers in order to reduce the parasitic absorption. We study how the local resistivity of the TCO evolves as a function of the patterns, and demonstrate how the increase of the series resistance can be compensated in order to increase the conversion efficiency.

  9. Seam-weld quality of modern ERW/HFI line pipe

    SciTech Connect

    Groeneveld, T.P.; Barnes, C.R.

    1991-09-01

    This study was undertaken to determine whether the seam-weld quality of modern ERW (electric resistance-welded)/HFI (high-frequency induction) welded pipe has been improved and justifies more widespread use of this type of pipe in critical applications. Wider use of ERW/HFI line pipe in gas-transmission lines would be expected to reduce construction costs. Five recently produced, heavy wall pipes fabricated using high-frequency electric-resistance welding (ERW) processes to make the seam weld and one pipe fabricated using the high-frequency induction (HFI) welding process to make the seam weld were studied. Four of the pipes were Grade X-60, one was Grade X-65, and one was Grade X-70. All of the pipes were produced from microalloyed, controlled-rolled steels, and the weld zones were post-weld normalized. Ultrasonic inspection of the seam welds in the six pipe sections evaluated revealed no indications of defects. The tensile properties of all of the weld zones exceeded the minimum specified yield strengths for the respective grades of pipe and all of the pipes exhibited ductile failures either in the weld zone or in the base metal. Five of the six pipes exhibited ductile failures either in the weld zone or in the base metal. Five of the six pipes exhibited relatively low 85% shear area transition temperatures and relatively high upper-shelf energy absorptions as determined with Charpy V-notch specimens. In addition, for two of the three joints of pipe for which the properties were determined at both ends of the pipe, the tensile and impact properties showed little variation from end-to-end. However, for the other joint of pipe, the impact properties varied substantially from one end to the other.

  10. Process for reducing series resistance of solar-cell metal-contact systems with a soldering-flux etchant

    DOEpatents

    Coyle, R.T.; Barrett, J.M.

    1982-05-04

    Disclosed is a process for substantially reducing the series resistance of a solar cell having a thick film metal contact assembly thereon while simultaneously removing oxide coatings from the surface of the assembly prior to applying solder therewith. The process includes applying a flux to the contact assembly and heating the cell for a period of time sufficient to substantially remove the series resistance associated with the assembly by etching the assembly with the flux while simultaneously removing metal oxides from said surface of said assembly.

  11. Effect of parasitic series resistances and spurious currents on the extracted temperature of a bipolar junction transistor.

    PubMed

    Mimila-Arroyo, J

    2013-12-01

    Verster's proposition to directly extract the temperature of a bipolar junction transistor using its collector current is widely used. However, the resulting temperature is low accurate even when calibrated. Here, it is demonstrated that the misuse of the emitter current instead of the collector one, because of the presence of spurious currents other than the injection-diffusion one and transistor parasitic series resistances both contribute to the observed inaccuracy. Particularly parasitic series resistances increase the inaccuracy and introduce a strong dependence of the extracted temperature on the collector currents used to extract the temperature; the higher those resistances the higher the inaccuracy. A proposition is made to reduce the effect of those resistances on the inaccuracy of this thermometric element, which allows obtaining a more accurate value on a wider range of the collector probe currents.

  12. ENHANCED COAL BED METHANE PRODUCTION AND SEQUESTRATION OF CO2 IN UNMINEABLE COAL SEAMS

    SciTech Connect

    William A. Williams

    2004-03-01

    The availability of clean, affordable energy is essential for the prosperity and security of the United States and the world in the 21st century. Emissions of carbon dioxide (CO{sub 2}) into the atmosphere are an inherent part of electricity generation, transportation, and industrial processes that rely on fossil fuels. These energy-related activities are responsible for more than 80 percent of the U.S. greenhouse gas emissions, and most of these emissions are CO{sub 2}. Over the last few decades, an increased concentration of CO{sub 2} in the earth's atmosphere has been observed. Carbon sequestration technology offers an approach to redirect CO{sub 2} emissions into sinks (e.g., geologic formations, oceans, soils and vegetation) and potentially stabilize future atmospheric CO{sub 2} levels. Coal seams are attractive CO{sub 2} sequestration sinks, due to their abundance and proximity to electricity-generation facilities. The recovery of marketable coalbed methane (CBM) provides a value-added stream, potentially reducing the cost to sequester CO{sub 2} gas. Much research is needed to evaluate this technology in terms of CO{sub 2} storage capacity, sequestration stability, commercial feasibility and overall economics. CONSOL Energy Inc., Research & Development (CONSOL), with support from the US DOE, has embarked on a seven-year program to construct and operate a coal bed sequestration site composed of a series of horizontally drilled wells that originate at the surface and extend through two overlying coal seams. Once completed, all of the wells will be used initially to drain CBM from both the upper (mineable) and lower (unmineable) coal seams. After sufficient depletion of the reservoir, centrally located wells in the lower coal seam will be converted from CBM drainage wells to CO{sub 2} injection ports. CO{sub 2} will be measured and injected into the lower unmineable coal seam while CBM continues to drain from both seams. In addition to metering all injected CO

  13. Photochemistry and photophysics at extended seams of conical intersection.

    PubMed

    Blancafort, Lluís

    2014-10-20

    The role of extended seams of conical intersection in excited-state mechanisms is reviewed. Seams are crossings of the potential energy surface in many dimensions where the decay from the excited to the ground state can occur, and the extended seam is composed of different segments lying along a reaction coordinate. Every segment is associated with a different primary photoproduct, which gives rise to competing pathways. This idea is first illustrated for fulvene and ethylene, and then it is used to explain more complex cases such as the dependence of the isomerisation of retinal chromophore isomers on the protein environment, the dependence of the efficiency of the azobenzene photochemical switch on the wavelength of irradiation and the direction of the isomerisation, and the coexistence of different mechanisms in the photo-induced Wolff rearrangement of diazonaphthoquinone. The role of extended seams in the photophysics of the DNA nucleobases and the relationship between two-state seams and three-state crossings is also discussed. As an outlook, the design of optical control strategies based on the passage of the excited molecule through the seam is considered, and it is shown how the excited-state lifetime of fulvene can be modulated by shaping the energy of the seam.

  14. First North American longwall in pitching seams proven feasible. [Colorado

    SciTech Connect

    Reynolds, J.F.

    1983-12-01

    There are 1.4 Gt (1.5 billion st) of recoverable coal under less than 914 m (3,000 ft) of cover in Colorado in pitching seams. Snowmass Coal Co., in cooperation with the US Department of Energy, introduced the longwall mining method in pitching seams to North America. This venture is a coal mining research program directed toward the profitable production of coal under difficult mining conditions as found in pitching seams of the western US. Snowmass Coal classifies pitching seams into the following categories for longwall on the strike in seams 3 m (10 ft) or less thick: Flat = 0 to 10/sup 0/: Normal continuous mines and shuttle cars work efficiently. Slight = 10/sup 0/ to 22/sup 0/: The maximum pitch that rubber tired equipment will function. Moderate = 22/sup 0/ to 40/sup 0/: The angle of repose of mined coal. Steep = 40/sup 0/ to 60/sup 0/: The limit of safe use of this roof support. Vertical = over 60/sup 0/. The longwall roof support covered here will work in all pitches except vertical. The shearer and conveyor will work in flat through moderate conditions. Longwalling across strike with this equipment in seam pitch over 60/sup 0/ could be accomplished with an inclined face. Development of the first longwall panel began in 1979 and was completed in 1981. The longwall equipment was installed and mining began on Aug. 11, 1981. Snowmass' performance shows that the capacity of a longwall operating on moderate pitch, up to 45/sup 0/, should be the same as a flat seam longwall. With equipment now available, pitching seam longwall is not only feasible, but cost competitive. The actual roof support method of troika concept has excellent maneuverability, good support, and low maintenance. The shearer has proven power to operate on moderate pitching seams.

  15. Analysis of Tidal DC Resistivity Time Series for Periodic Saltwater Mixing Patterns and Determination of Hydraulic Ground Properties

    NASA Astrophysics Data System (ADS)

    Sutter, E. M.; Ingham, M.

    2016-12-01

    Saline intrusion research using geoelectrical time-lapse monitoring, is often directed towards imaging the saltwater-freshwater boundary and the amount of seawater mixing within a coastal aquifer. However, these time series can contain additional information about subsurface hydrologic properties like hydraulic conductivity and permeability which are crucial elements in coastal groundwater management. In this study, DC resistivity time series from tidal time-lapse monitoring surveys of a shallow coastal sand and gravel aquifer in New Zealand have been analysed for recurring patterns of percentage seawater mixing in different portions of the aquifer. The results show a distinctly different behaviour of percentage seawater change with time for several horizontal locations along two profile lines with varying depth. In addition, the geoelectric time series have been cross-correlated with tidal stage data approximated near the survey location in order to find portions of the aquifer that exhibit different time lags with respect to a diurnal tidal cycle. First results yield a remarkably similar picture to resistivity ratios obtained between high and low tide inversion models of the DC resistivity time series both at different locations and for different seasons. The two methods indicate a correlation between rising and falling tides and the resistivity changes observed from geoelectrical monitoring studies .This may be used to distinguish between more or less hydraulically conductive portions of a coastal aquifer.

  16. Optimization of an indazole series of selective estrogen receptor degraders: Tumor regression in a tamoxifen-resistant breast cancer xenograft.

    PubMed

    Govek, Steven P; Nagasawa, Johnny Y; Douglas, Karensa L; Lai, Andiliy G; Kahraman, Mehmet; Bonnefous, Celine; Aparicio, Anna M; Darimont, Beatrice D; Grillot, Katherine L; Joseph, James D; Kaufman, Joshua A; Lee, Kyoung-Jin; Lu, Nhin; Moon, Michael J; Prudente, Rene Y; Sensintaffar, John; Rix, Peter J; Hager, Jeffrey H; Smith, Nicholas D

    2015-11-15

    Selective estrogen receptor degraders (SERDs) have shown promise for the treatment of ER+ breast cancer. Disclosed herein is the continued optimization of our indazole series of SERDs. Exploration of ER degradation and antagonism in vitro followed by in vivo antagonism and oral exposure culminated in the discovery of indazoles 47 and 56, which induce tumor regression in a tamoxifen-resistant breast cancer xenograft.

  17. A Multi-Axis Seam Tracking sensor for joining applications

    SciTech Connect

    Novak, J.L.; Schmitt, D.J.; Maslakowski, J.

    1993-11-01

    This paper describes the development and use of the Multi-Axis Seam Tracking (MAST) sensor for tracking seams or other features in real-time. Four independent, spatially-distributed electric fields are used to sense changes in the relative position of the sensor and the workpiece. The MAST sensor is very inexpensive compared with commercially available seam tracking sensors. It can be used in systems to perform cost-effective small-lot manufacturing operations in a faster, more consistent manner. The MAST sensor is used in an automated system for dispensing braze paste during a rocket nozzle fabrication process.

  18. Multi-Axis Seam Tracking using a noncontact capacitive sensor

    SciTech Connect

    Novak, J.L.; Schmitt, D.J.; Maslakowski, J.

    1993-08-01

    This paper describes the development and use of the Multi-Axis Seam racking (MAST) sensor for tracking seams or other features in real-time. Four independent, spatially-distributed electric fields are used to sense changes in the relative position of the sensor and the workpiece. The MAST sensor is very inexpensive compared with commercially available seam tracking sensors. It can be used in systems to perform cost-effective small-lot manufacturing operations in a faster, more consistent manner. The MAST sensor is used in an automated system for dispensing braze paste during a rocket nozzle fabrication process.

  19. Modelling bulk surface resistance from MODIS time series data to estimate actual regional evapotranspiration

    NASA Astrophysics Data System (ADS)

    Autovino, Dario; Minacapilli, Mario; Provenzano, Giuseppe

    2015-04-01

    Estimation of actual evapotraspiration by means of Penman-Monteith (P-M) equation requires the knowledge of the so-called 'bulk surface resistance', rc,act, representing the vapour flow resistance through the transpiring crop and evaporating soil surface. The accurate parameterization of rc,act still represents an unexploited topic, especially in the case of heterogeneous land surface. In agro-hydrological applications, the P-M equation commonly used to evaluate reference evapotranspiration (ET0) of a well-watered 'standardized crop' (grass or alfalfa), generally assumes for the bulk surface resistance a value of 70 s m-1. Moreover, specific crop coefficients have to be used to estimate maximum and/or actual evapotranspiration based on ET0. In this paper, a simple procedure for the indirect estimation of rc,act as function of a vegetation index computed from remote acquisition of Land Surface Temperature (LST), is proposed. An application was carried out in an irrigation district located near Castelvetrano, in South-West of Sicily, mainly cultivated with olive groves, in which actual evapotranspiration fluxes were measured during two years (2010-2011) by an Eddy Covariance flux tower (EC). Evapotranspiration measurements allowed evaluating rc,actbased on the numerical inversion of the P-M equation. In the same study area, a large time series of MODIS LST data, characterized by a spatial resolution of 1x1 km and a time step of 8-days, was also acquired for the period from 2000 to 2014. A simple Vegetation Index Temperatures (VTI), with values ranging from 0 to 1, was computed using normalized LST values. Evapotranspiration fluxes measured in 2010 were used to calibrate the relationship between rc,act and VTI, whereas data from 2011 were used for its validation. The preliminary results evidenced that, for the considered crop, an almost constant value of rc,act, corresponding to about 250 s m-1, can be considered typical of periods in which the crop is well

  20. Vagus nerve stimulation for children with treatment-resistant epilepsy: a consecutive series of 141 cases.

    PubMed

    Elliott, Robert E; Rodgers, Shaun D; Bassani, Luigi; Morsi, Amr; Geller, Eric B; Carlson, Chad; Devinsky, Orrin; Doyle, Werner K

    2011-05-01

    The authors undertook this study to analyze the efficacy of vagus nerve stimulation (VNS) in a large consecutive series of children 18 years of age and younger with treatment-resistant epilepsy and compare the safety and efficacy in children under 12 years of age with the outcomes in older children. The authors retrospectively reviewed 141 consecutive cases involving children (75 girls and 66 boys) with treatment-resistant epilepsy in whom primary VNS implantation was performed by the senior author between November 1997 and April 2008 and who had at least 1 year of follow-up since implantation. The patients' mean age at vagus nerve stimulator insertion was 11.1 years (range 1-18 years). Eighty-six children (61.0%) were younger than 12 years at time of VNS insertion (which constitutes off-label usage of this device). Follow-up was complete for 91.8% of patients and the mean duration of VNS therapy in these patients was 5.2 years (range 25 days-11.4 years). Seizure frequency significantly improved with VNS therapy (mean reduction 58.9%, p < 0.0001) without a significant reduction in antiepileptic medication burden (median number of antiepileptic drugs taken 3, unchanged). Reduction in seizure frequency of at least 50% occurred in 64.8% of patients and 41.4% of patients experienced at least a 75% reduction. Major (3) and minor (6) complications occurred in 9 patients (6.4%) and included 1 deep infection requiring device removal, 1 pneumothorax, 2 superficial infections treated with antibiotics, 1 seroma/hematoma treated with aspiration, persistent cough in 1 patient, severe but transient neck pain in 1 patient, and hoarseness in 2 patients. There was no difference in efficacy or complications between children 12 years of age and older (FDA-approved indication) and those younger than 12 years of age (off-label usage). Linear regression analyses did not identify any demographic and clinical variables that predicted response to VNS. Vagus nerve stimulation is a safe and

  1. High-performance carbon nanotube-implanted mesoporous carbon spheres for supercapacitors with low series resistance

    SciTech Connect

    Yi, Bin; Chen, Xiaohua; Guo, Kaimin; Xu, Longshan; Chen, Chuansheng; Yan, Haimei; Chen, Jianghua

    2011-11-15

    Research highlights: {yields} CNTs-implanted porous carbon spheres are prepared by using gelatin as soft template. {yields} Homogeneously distributed CNTs form a well-develop network in carbon spheres. {yields} CNTs act as a reinforcing backbone assisting the formation of pore structure. {yields} CNTs improve electrical conductivity and specific capacitance of supercapacitor. -- Abstract: Carbon nanotube-implanted mesoporous carbon spheres were prepared by an easy polymerization-induced colloid aggregation method using gelatin as a soft template. Scanning electron microscopy, transmission electron microscopy and nitrogen adsorption-desorption measurements reveal that the materials are mesoporous carbon spheres, with a diameter of {approx}0.5-1.0 {mu}m, a specific surface area of 284 m{sup 2}/g and average pore size of 3.9 nm. Using the carbon nanotube-implanted mesoporous carbon spheres as electrode material for supercapacitors in an aqueous electrolyte solution, a low equivalent series resistance of 0.83 {Omega} cm{sup 2} and a maximum specific capacitance of 189 F/g with a measured power density of 8.7 kW/kg at energy density of 6.6 Wh/kg are obtained.

  2. Effects of temperature and series resistance on GaAs concentrator solar cell

    NASA Astrophysics Data System (ADS)

    Khelifi, S.; Ayat, L.; Belghachi, A.

    2008-02-01

    Concentrators use reflection or refraction of light, or a combination of both, but concentration of light leads to a crucial heating of the cell, which involves degradation of its performance. However, solar cells especially conceived for concentration can support very intense illuminations as far as an active cooling is assured. In this work, a GaAs solar cell with Al{x}Ga{1-x}As window layer, operating under low injection conditions, has been studied with temperature and solar concentration. The temperature corresponding to each concentration was calculated, and then used in the calculation of photovoltaic parameters. The study was carried out under free mode conditions (without heat sink) and then under forced conditions (with a cooling system) in order to demonstrate the importance of cooling in the concentrator solar cells. The effect of series resistance on solar cell characteristics has also been studied. The simulation was carried out using SCAPS-1D simulator. The results were compared with those obtained theoretically; a good agreement was found between the two models.

  3. A general and precise method to evaluate the series resistance of photovoltaic cells from I-V characteristics

    NASA Astrophysics Data System (ADS)

    Chibbaro, C.; Zimbone, M.; Litrico, G.; Baeri, P.; Lo Trovato, M. L.; Aleo, F.

    2011-08-01

    This paper presents a general method for extracting solar cell parameters from current- voltage characteristics obtained under illumination. In particular, it focuses on the problem of measuring very low values of series resistance with sufficient precision. The method makes use of two different sets of experimental data: a cell current-voltage characteristic measured at a fixed sun irradiance level and a set of short circuit current and open circuit voltage value pairs measured at various sun irradiance levels. The method involves an interplay of different fitting procedures iteratively performed to these two data sets. The method is tested on two single junction silicon cells with the same very low series resistance however, having two very different values of shunt resistance. It is shown that in both cases this method is much more precise and reproducible than other conventional methods.

  4. Time-series analysis in imatinib-resistant chronic myeloid leukemia K562-cells under different drug treatments.

    PubMed

    Zhao, Yan-Hong; Zhang, Xue-Fang; Zhao, Yan-Qiu; Bai, Fan; Qin, Fan; Sun, Jing; Dong, Ying

    2017-08-01

    Chronic myeloid leukemia (CML) is characterized by the accumulation of active BCR-ABL protein. Imatinib is the first-line treatment of CML; however, many patients are resistant to this drug. In this study, we aimed to compare the differences in expression patterns and functions of time-series genes in imatinib-resistant CML cells under different drug treatments. GSE24946 was downloaded from the GEO database, which included 17 samples of K562-r cells with (n=12) or without drug administration (n=5). Three drug treatment groups were considered for this study: arsenic trioxide (ATO), AMN107, and ATO+AMN107. Each group had one sample at each time point (3, 12, 24, and 48 h). Time-series genes with a ratio of standard deviation/average (coefficient of variation) >0.15 were screened, and their expression patterns were revealed based on Short Time-series Expression Miner (STEM). Then, the functional enrichment analysis of time-series genes in each group was performed using DAVID, and the genes enriched in the top ten functional categories were extracted to detect their expression patterns. Different time-series genes were identified in the three groups, and most of them were enriched in the ribosome and oxidative phosphorylation pathways. Time-series genes in the three treatment groups had different expression patterns and functions. Time-series genes in the ATO group (e.g. CCNA2 and DAB2) were significantly associated with cell adhesion, those in the AMN107 group were related to cellular carbohydrate metabolic process, while those in the ATO+AMN107 group (e.g. AP2M1) were significantly related to cell proliferation and antigen processing. In imatinib-resistant CML cells, ATO could influence genes related to cell adhesion, AMN107 might affect genes involved in cellular carbohydrate metabolism, and the combination therapy might regulate genes involved in cell proliferation.

  5. 10. DETAIL VIEW OF SIDEWALK RAILING, SHOWING WELDED SEAM, 'ILLINOISSUSA' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. DETAIL VIEW OF SIDEWALK RAILING, SHOWING WELDED SEAM, 'ILLINOIS-S-USA' ROLLER MARK, AND WELDER'S INITIALS ('C.K.'), LOOKING NORTH-NORTHWEST Harms - Benton Street Bridge, Spanning Iowa River at Benton Street, Iowa City, Johnson County, IA

  6. Shield support selection based on geometric characteristics of coal seam

    SciTech Connect

    K. Goshtasbi; K. Oraee; F. Khakpour-yeganeh

    2006-01-15

    The most initial investment in longwall face equipping is the cost of powered support. Selection of proper shields for powered supports is based on load, geometric characterization of coal seams and economical considerations.

  7. Seam tracking performance of a Coaxial Weld Vision System and pulsed welding

    NASA Technical Reports Server (NTRS)

    Gangl, K. J.; Weeks, J. L.; Todd, D.

    1986-01-01

    This report describes a continuation of a series of tests on the Coaxial Weld Vision System at MSFC. The ability of the system to compensate for transients associated with pulsed current welding is analyzed. Using the standard image processing approach for root pass seam tracking, the system is also tested for the ability to track the toe of a previous weld bead, for tracking multiple pass weld joints. This Coaxial Weld Vision System was developed by the Ohio State University (OSU) Center for Welding Research and is a part of the Space Shuttle Main Engine Robotic Welding Development System at MSFC.

  8. The behavior of series resistance of a p-n junction: the diode and the solar cell cases

    NASA Astrophysics Data System (ADS)

    Bueno, Poliana H.; Costa, Diogo F.; Eick, Alexander; Carvalho, André; Monteiro, Davies W. L.

    2016-03-01

    This paper presents a comparison of the impact of the internal parasitic series resistance of a p-n junction, as seen from the microelectronics and photovoltaic communities. The elusive thermal behavior of the aforementioned resistance gave this work its origin. Each community uses a different approach to interpret the operational current-voltage behavior of a p-n junction, which might lead to confusion, since scientists and engineers of these two realms seldom interact. An improvement in the understanding of the different approaches will help one to better model the performance of devices based on p-n junctions and therefore it will favor the performance predictions of photovoltaic cells. For diodes, series resistance is usually determined from a specific forward-bias region of the I-V curve on a semi-logarithmic scale. However, in Photovoltaics this region is not commonly reported and therefore other methods to determine Rs are employed. We mathematically modeled an experimentally obtained I-V curve with various pairs of the ideality factor and Rs and found that more than one pair accurately synthesizes the measured curve. We can conclude that the reported series resistance not only depends on physical parameters, e.g. temperature or irradiance, but also on fitting parameters, i.e. the ideality factor. Generally the behavior of a p-n junction depends on its operating conditions and electrical modeling.

  9. Technique development for field inspection of cracking in seam welded ducts

    SciTech Connect

    Shell, Eric B.; Benson, Craig; Liljestrom, Greg C.; Shanahan, Stephen

    2014-02-18

    The resistance seam weld interfaces between alloyed and pure titanium are an in service concern due to precipitation of titanium hydride and resulting embrittlement and cracking. Several inspection techniques were developed and evaluated for field use to characterize the damage in the fleet. Electromagnetic, ultrasonic, florescent penetrant, thermographic, and radiographic techniques were considered. The ultrasonic and electromagnetic approaches were both found suitable. However, the electromagnetic approach is more desirable for field inspections, due to consistency and ease of use. The electromagnetic inspection procedure is able to discriminate between precursor damage and through cracking with sufficient sensitivity to small cracks.

  10. Exact analytical solutions of the forward non-ideal diode equation with series and shunt parasitic resistances

    NASA Astrophysics Data System (ADS)

    Ortiz-Conde, Adelmo; García Sánchez, Francisco J.; Muci, Juan

    2000-10-01

    Exact closed form solutions based on the Lambert W-function are presented to express the forward current-voltage characteristics of non-ideal single-exponential diodes containing all possible combinations of series and shunt parasitic resistances. It is shown that these expressions could be useful for carrying out highly accurate computations at speeds almost as fast as those possible when using less precise approximate solutions based on common elementary functions.

  11. Study on gas permeability coefficient measurement of coal seam by radial flow method

    NASA Astrophysics Data System (ADS)

    Zhang, Shuchuan

    2017-08-01

    For the accurate measurement of the coal seam permeability coefficient, the application range of the coal seam permeability coefficient was studied under various gas flow conditions with the guidance of the coal seam gas flow theory. Adopting the radial flow method, the measurement and calculation of the permeability coefficient of the coal seam C13-1 in Xinji No.1 Coal Mine shows that the permeability coefficient of the original coal seam C13-1 is less than 0.1, and the coal seam is difficult to extract.

  12. Liquid-phase silylation characterization of Shipley SPR500A-series resists using PRIME top surface imaging process

    NASA Astrophysics Data System (ADS)

    Arshak, Khalil I.; Mihov, Miroslav; Arshak, Arousian; McDonagh, Declan; Sutton, David; Newcomb, Simon; Kinsella, Thomas J.

    2003-03-01

    Top Surface Imaging (TSI) is a well-established technique used to improve resolution for optical, ultraviolet and electron-beam lithography. The Positive Resist Image by Dry Etching (PRIME) is an advanced lithographic process incorporating electron beam exposure, near UV flood exposure, silylation and dry development. In this paper, the liquid-phase silylation process step in PRIME with Shipley SPR500A-series resists has been experimentally investigated as the most critical part of the process. FT-IR spectroscopy, UV spectroscopy, SIM spectrometry and cross-sectional SEM and TEM were used to characterise the silylation process. Electron-beam exposure with dose in the range of 25-100μC/cm2 at 30KeV was used to crosslinks the resist. Results show that an e-beam dose of 50³C/cm2 was sufficient to prevent silylation in the crosslinked areas. Two bifunctional silylating agents, the cyclic Hexamethylcyclotrisilazane (HMCTS) and the linear Bis[Dimethylamino] dimethylsilane (B[DMA]DMS), were examined and found that they silylate SPR505A much more efficiently than the previously reported Hexamethylcyclotrisiloxane (HMCTSx). The silylation contrast of the PRIME process using HMCTS silylating agent and SPR505A resist was found to be 11:1. The obtained silylated profiles of 1mm lines/spaces gratings for Shipley SPR510A resist have almost vertical sidewalls resulting in very high contrast between the silylated and unsilylated parts of the resist.

  13. ENHANCED COAL BED METHANE PRODUCTION AND SEQUESTRATION OF CO2 IN UNMINEABLE COAL SEAMS

    SciTech Connect

    Gary L. Cairns

    2002-10-01

    The availability of clean, affordable energy is essential for the prosperity and security of the United States and the world in the 21st century. Carbon dioxide (CO{sub 2}) emissions to the atmosphere are an inherent part of energy-related activities, such as electricity generation, transportation, and building systems. These energy-related activities are responsible for roughly 85% of the U.S. greenhouse gas emissions, and 95% of these emissions are dominated by CO{sub 2}. Over the last few decades, an increased concentration of CO{sub 2} in the earth's atmosphere has been observed. Many scientists believe greenhouse gases, particularly CO{sub 2}, trap heat in the earth's atmosphere. Carbon sequestration technology offers an approach to redirect CO{sub 2} emissions into sinks (e.g., geologic formations, oceans, soils, and vegetation) and potentially stabilize future atmospheric CO{sub 2} levels. Coal seams are attractive CO{sub 2} sequestration sinks, due to their abundance and proximity to electricity-generation facilities. The recovery of marketable coal bed methane (CBM) provides a value-added stream, reducing the cost to sequester CO{sub 2} gas. Much research is needed to evaluate this technology in terms of CO{sub 2} storage capacity, sequestration stability, commercial feasibility and overall economics. CONSOL Energy, with support from the U.S. DOE, is conducting a seven-year program to construct and operate a coal bed sequestration site composed of a series of horizontally drilled wells that originate at the surface and extend through overlying coal seams in the subsurface. Once completed, the wells will be used to initially drain CBM from both the upper (mineable) and lower (unmineable) coal seams. After sufficient depletion of the reservoir, centrally located wells in the lower coal seam will be converted from CBM drainage wells to CO{sub 2} injection ports. CO{sub 2} will be measured and injected into the lower unmineable coal seam while CBM continues to

  14. Flow in Coal Seams: An Unconventional Challenge

    NASA Astrophysics Data System (ADS)

    Armstrong, R. T.; Mostaghimi, P.; Jing, Y.; Gerami, A.

    2016-12-01

    A significant unconventional resource for energy is the methane gas stored in shallow coal beds, known as coal seam gas. An integrated imaging and modelling framework is developed for analysing petrophysical behaviour of coals. X-ray micro-computed tomography (micro-CT) is applied using a novel contrast agent method for visualising micrometer-sized fractures in coal. The technique allows for the visualisation of coal features not visible with conventional imaging methods. A Late Permian medium volatile bituminous coal from Moura Coal Mine (Queensland, Australia) is imaged and the resulting three-dimensional coal fracture system is extracted for fluid flow simulations. The results demonstrate a direct relationship between coal lithotype and permeability. Scanning electron microscope and energy dispersive spectrometry (SEM-EDS) together with X-ray diffraction (XRD) methods are used for identifying mineral matters at high resolution. SEM high-resolution images are also used to calibrate the micro-CT images and measure the exact aperture size of fractures. This leads to a more accurate estimation of permeability using micro-CT images. To study the significance of geometry and topology of the fracture system, a fracture reconstruction method based on statistical properties of coal is also developed. The network properties including the frequency, aperture size distribution, length, and spacing of the imaged coal fracture system. This allows for a sensitivity analysis on the effects that coal fracture topology and geometry has on coal petrophysical properties. Furthermore, we generate microfluidic chips based on coal fracture observations. The chip is used for flow experiments to visualise multi-fluid processes and measure recovery of gas. A combined numerical and experimental approach is applied to obtain relative permeability curves for different regions of interest. A number of challenges associated with coal samples are discussed and insights are provided for better

  15. Filter properties of seam material from paved urban soils

    NASA Astrophysics Data System (ADS)

    Nehls, T.; Jozefaciuk, G.; Sokolowska, Z.; Hajnos, M.; Wessolek, G.

    2008-04-01

    Depositions of all kinds of urban dirt and dust including anthropogenic organic substances like soot change the filter properties of the seam filling material of pervious pavements and lead to the formation of a new soil substrate called seam material. In this study, the impact of the particular urban form of organic matter (OM) on the seam materials CECpot, the specific surface area (As), the surface charge density (SCD), the adsorption energies (Ea) and the adsorption of Cd and Pb were assessed. The Cd and Pb displacement through the pavement system has been simulated in order to assess the risk of soil and groundwater contamination from infiltration of rainwater in paved urban soils. As, Ea and SCD derived from water vapor adsorption isotherms, CECpot, Pb and Cd adsorption isotherms where analyzed from adsorption experiments. The seam material is characterized by a darker munsell-color and a higher Corg (12 to 48g kg-1) compared to the original seam filling. Although, the increased Corg leads to higher As (16m2g-1) and higher CECpot (0.7 to 4.8cmolckg-1), with 78cmolckg-1C its specific CECpot is low compared to OM of non-urban soils. This can be explained by a low SCD of 1.2×10-6molc m-2 and a low fraction of high adsorption energy sites which is likely caused by the non-polar character of the accumulated urban OM in the seam material. The seam material shows stronger sorption of Pb and Cd compared to the original construction sand. The retardation capacity of seam material for Pb is similar, for Cd it is much smaller compared to natural sandy soils with similar Corg concentrations. The simulated long term displacement scenarios for a street in Berlin do not indicate an acute contamination risk for Pb . For Cd the infiltration from puddles can lead to a breakthrough of Cd through the pavement system during only one decade. Although they contain contaminations itself, the accumulated forms of urban OM lead to improved filter properties of the seam material and

  16. Front Side Metallization of n- and p-Type, High-Efficiency, Single-Crystalline Si Solar Cells: Assessing the Temperature-Dependent Series Resistance

    NASA Astrophysics Data System (ADS)

    Willsch, Benjamin; Kumar, Praveen; Eibl, Oliver

    2016-06-01

    The series resistance of high-quality, single crystalline p-type and n-type solar cells was measured in a temperature range between 80 K and room temperature. Among one cell type ( n or p), cells were processed identically. Only the processing of the front side metallization was varied by using different processing conditions and screen printing pastes. High-efficiency n- ( η = 20.0%) and p-type ( η = 18.0%) cells yielded similar contact and series resistance and common features of the microstructure of the front side contact, i.e. a glass layer containing Ag colloids with typical diameters of 5-200 nm. Temperature-dependent current voltage curves ( I- V curves) were acquired and evaluated with respect to the series resistance by using two different methods yielding different results. On average the series resistance follows the trends of the contact resistance of the front side metallization determined at room temperature. Optimally processed cells yielded series resistances of less than 25 mΩ cm2 (method #1) both for n- and p-type cells. It could be shown that the series resistance reflected the processing conditions and paste properties and yielded similar temperature dependence for p- and n-type cells with small contact resistance. Therefore, the relevant current paths of high-efficiency n- and p-type cells appear to be similar in the front side metallization and include the glass layer which contains a high density of Ag colloids.

  17. Conical intersection seams in polyenes derived from their chemical composition.

    PubMed

    Nenov, Artur; de Vivie-Riedle, Regina

    2012-08-21

    The knowledge of conical intersection seams is important to predict and explain the outcome of ultrafast reactions in photochemistry and photobiology. They define the energetic low-lying reachable regions that allow for the ultrafast non-radiative transitions. In complex molecules it is not straightforward to locate them. We present a systematic approach to predict conical intersection seams in multifunctionalized polyenes and their sensitivity to substituent effects. Included are seams that facilitate the photoreaction of interest as well as seams that open competing loss channels. The method is based on the extended two-electron two-orbital method [A. Nenov and R. de Vivie-Riedle, J. Chem. Phys. 135, 034304 (2011)]. It allows to extract the low-lying regions for non-radiative transitions, which are then divided into small linear segments. Rules of thumb are introduced to find the support points for these segments, which are then used in a linear interpolation scheme for a first estimation of the intersection seams. Quantum chemical optimization of the linear interpolated structures yields the final energetic position. We demonstrate our method for the example of the electrocyclic isomerization of trifluoromethyl-pyrrolylfulgide.

  18. Conical intersection seams in polyenes derived from their chemical composition

    NASA Astrophysics Data System (ADS)

    Nenov, Artur; de Vivie-Riedle, Regina

    2012-08-01

    The knowledge of conical intersection seams is important to predict and explain the outcome of ultrafast reactions in photochemistry and photobiology. They define the energetic low-lying reachable regions that allow for the ultrafast non-radiative transitions. In complex molecules it is not straightforward to locate them. We present a systematic approach to predict conical intersection seams in multifunctionalized polyenes and their sensitivity to substituent effects. Included are seams that facilitate the photoreaction of interest as well as seams that open competing loss channels. The method is based on the extended two-electron two-orbital method [A. Nenov and R. de Vivie-Riedle, J. Chem. Phys. 135, 034304 (2011)], 10.1063/1.3608924. It allows to extract the low-lying regions for non-radiative transitions, which are then divided into small linear segments. Rules of thumb are introduced to find the support points for these segments, which are then used in a linear interpolation scheme for a first estimation of the intersection seams. Quantum chemical optimization of the linear interpolated structures yields the final energetic position. We demonstrate our method for the example of the electrocyclic isomerization of trifluoromethyl-pyrrolylfulgide.

  19. Conical intersection seams in polyenes derived from their chemical composition

    SciTech Connect

    Nenov, Artur; Vivie-Riedle, Regina de

    2012-08-21

    The knowledge of conical intersection seams is important to predict and explain the outcome of ultrafast reactions in photochemistry and photobiology. They define the energetic low-lying reachable regions that allow for the ultrafast non-radiative transitions. In complex molecules it is not straightforward to locate them. We present a systematic approach to predict conical intersection seams in multifunctionalized polyenes and their sensitivity to substituent effects. Included are seams that facilitate the photoreaction of interest as well as seams that open competing loss channels. The method is based on the extended two-electron two-orbital method [A. Nenov and R. de Vivie-Riedle, J. Chem. Phys. 135, 034304 (2011)]. It allows to extract the low-lying regions for non-radiative transitions, which are then divided into small linear segments. Rules of thumb are introduced to find the support points for these segments, which are then used in a linear interpolation scheme for a first estimation of the intersection seams. Quantum chemical optimization of the linear interpolated structures yields the final energetic position. We demonstrate our method for the example of the electrocyclic isomerization of trifluoromethyl-pyrrolylfulgide.

  20. Theoretical basis and application of vertical Z-component in-seam wave exploration

    NASA Astrophysics Data System (ADS)

    He, Wenxin; Ji, Guangzhong; Dong, Shouhua; Li, Gang

    2017-03-01

    Love seam waves are generally applied to the current in-seam wave explorations. Rayleigh seam waves, however, are rarely used. The dispersion and amplitude features of Rayleigh seam waves are investigated using frequency dispersion analysis and numerical simulations in this study. Firstly, we elucidate the advantages of using the vertical Z-component. Secondly, the theoretical basis standing behind its application to in-seam wave explorations is demonstrated. Furthermore, in order to compare the relative performances of Rayleigh and Love seam wave explorations, three-dimensional geological models with anomalies are numerically simulated. Thus, the feasibilities and actual exploration effects of Z-component in-seam waves are demonstrated for both theoretical models and practical applications. Our studies show that normal modes of Rayleigh seam waves always exist. Furthermore, the energy of the fundamental mode in-seam wave is concentrated in its Z-component for the middle of a coal seam. A compressional wave source primarily generates first-order mode Rayleigh seam waves whereas a shear wave source primarily excites fundamental mode Rayleigh seam waves, whose energy is concentrated in the Airy phase with the lowest velocity. The fundamental mode Z-components at the center of a coal seam are ideal for in-seam wave applications. Actually, fundamental and first-order mode in-seam waves can be recorded in most coal seams. The Z-component receivers can be placed at the location between 1/4 and 1/2 of the thickness of coal seam, where both wave modes could be detected.

  1. Full-scale aircraft cabin flammability tests of improved fire-resistant materials, test series 2

    NASA Technical Reports Server (NTRS)

    Stuckey, R. N.; Bricker, R. W.; Kuminecz, J. F.; Supkis, D. E.

    1976-01-01

    Full-scale aircraft flammability tests in which the effectiveness of new fire-resistant materials was evaluated by comparing their burning characteristics with those of other fire-resistant aircraft materials were described. New-fire-resistant materials that are more economical and better suited for aircraft use than the previously tested fire-resistant materials were tested. The fuel ignition source for one test was JP-4; a smokeless fuel was used for the other test. Test objectives, methods, materials, and results are presented and discussed. The results indicate that, similar to the fire-resistant materials tested previously, the new materials decompose rather than ignite and do not support fire propagation. Furthermore, the new materials did not produce a flash fire.

  2. Construction of Skin Graft Seams in Burn Patients: A Prospective Randomized Double-Blinded Study.

    PubMed

    Isaac, Kathryn; Umraw, Nisha; Cartotto, Robert

    Prominent scars and contractures may form along the seams between adjacent skin grafts. Seams may be constructed either by approximating the graft edges (AP), or by slightly overlapping the graft edges (OV), but it is not known if one technique creates a less conspicuous seam scar. The purpose of this study was to compare seam scars between seams constructed using the AP and OV techniques. This was a prospective within-patient and within-seam controlled study in adult burn patients treated at an American Burn Association-verified burn center. At skin graft application and seam construction, study seams were divided in half. One half of the seam was made by approximating the graft edges (AP group), while the other half was made by overlapping graft edges (OV group), before identical staple or suture fixation of each half. The AP or OV technique was randomly assigned to the medial or lateral ends of transversely oriented seams or to the proximal and distal ends of longitudinally oriented seams. At 3, 6, and 12 months post surgery, a blinded rater compared the two halves of each study seam scar using the Vancouver Scar Score (VSS). Subjects were also blinded and rated each half of their study seam using a 0 (poor) to 10 (excellent) visual analogue scale. Values are shown as the median (Q1-Q3). There were 44 study seams among 19 subjects (age 51 [36-70] years, with % TBSA burn 10 [7-18], % BSA full-thickness burn 8 [6-15]). Study seams were constructed at 10 (4-15) days post burn. Study seam length was 14.5 (10.3-18.0) cm, with 25% transversely oriented and 75% longitudinally oriented, and with 35/44 seams (80%) between meshed grafts and 9/44 (20%) between sheet grafts. There were no significant differences in any of the individual domain VSS scores (height, pliability, vascularity, and pigmentation) or total VSS score between AP and OV seams at 3, 6, and 12 months. At 12 months, among the 30 study seams that were visible to the subjects, the visual analogue scale

  3. A reliable extraction method for source and drain series resistances in silicon nanowire metal-oxide-semiconductor field-effect-transistors (MOSFETs) based on radio-frequency analysis.

    PubMed

    Hwa, Jae Hwa; Yoon, Young Jun; Lee, Hwan Gi; Yoo, Gwan Min; Cho, Eou-Sik; Cho, Seongjae; Lee, Jung-Hee; Kang, In Man

    2014-11-01

    This paper presents a new extraction method for source and drain (S/D) series resistances of silicon nanowire (SNW) metal-oxide-semiconductor field-effect transistors (MOSFETs) based on small-signal radio-frequency (RF) analysis. The proposed method can be applied to the extraction of S/D series resistances for SNW MOSFETs with finite off-state channel resistance as well as gate bias-dependent on-state resistive components realized by 3-dimensional (3-D) device simulation. The series resistances as a function of frequency and gate voltage are presented and compared with the results obtained by an existing method with infinite off-state channel resistance model. The accuracy of the newly proposed parameter extraction method has been successfully verified by Z22- and Y-parameters up to 100 GHz operation frequency.

  4. Blonanserin Augmentation for Treatment-Resistant Somatic Symptom Disorder: A Case Series.

    PubMed

    Nagoshi, Yasuhide; Tominaga, Toshiyuki; Fukui, Kenji

    2016-01-01

    The augmentation of selective serotonin reuptake inhibitors with antipsychotics that have a high dopamine-receptor-D2 affinity may be effective in treatment-resistant obsessive-compulsive disorder and somatic symptom disorder, which is similar to illness anxiety disorder. Blonanserin, a novel antipsychotic developed in Japan, has a high affinity for the D2 receptor and weak or very little affinity for other receptors. This article presents two case studies that demonstrate the efficacy of blonanserin augmentation for treatment-resistant somatic symptom disorder. Two patients with treatment-resistant somatic symptom disorder were prescribed concomitant use of blonanserin. Augmentation with blonanserin resulted in the remarkable amelioration of all symptoms. Sedative adverse drug reactions produced by aripiprazole were improved after replacing it with blonanserin. Blonanserin is effective in treatment-resistant somatic symptom disorder. Furthermore, compared with aripiprazole, blonanserin is more likely to result in medication adherence in patients with somatic symptom disorder because it reduced adverse drug reactions.

  5. Electrical parameters and series resistance analysis of Au/Y/p-InP/Pt Schottky barrier diode at room temperature

    NASA Astrophysics Data System (ADS)

    Rao, L. Dasaradha; Reddy, V. Rajagopal

    2016-05-01

    The current-voltage (I-V) characteristics of Au/Y/p-InP/Pt Schottky barrier diode (SBD) are analyzed at room temperature. The Au/Y/p-InP/Pt SBD shows a good rectification behavior. The ideality factor (n), barrier height (Φb), series resistance (Rs) and shunt resistance (Rsh) are determined from the I-V measurements. The n and Φb values of Au/Y/p-InP/Pt SBD are found to be 1.32 and 0.62 eV respectively. The value of barrier height (BH) obtained from Norde function is compared with those calculated from Cheung's functions. The series resistance (Rs) is calculated from Cheung's and modified Norde functions. Additionally, it is found that n, Φb, Rs, and Rsh have strong correlation with the applied bias. Furthermore, at low and high voltage regions, ohmic and space-charge-limited conduction mechanisms are found to govern the current flow in the diode.

  6. Seam-Tracking for Friction Stir Welded Lap Joints

    NASA Astrophysics Data System (ADS)

    Fleming, Paul A.; Hendricks, Christopher E.; Cook, George E.; Wilkes, D. M.; Strauss, Alvin M.; Lammlein, David H.

    2010-11-01

    This article presents a method for automatic seam-tracking in friction stir welding (FSW) of lap joints. In this method, tracking is accomplished by weaving the FSW tool back-and-forth perpendicular to the direction of travel during welding and monitoring force and torque signals. Research demonstrates the ability of this method to automatically track weld seam positions. Additionally, tensile and S-bend test result comparisons demonstrate that weaving most likely does not reduce weld quality. Finally, benefits of this weave-based method to FSW of lap joints are discussed and methods for incorporating it into existing friction stir welding control algorithms (such as axial load control) are examined.

  7. Introducing defects into metal-seamed nanocapsules using mixed macrocycles.

    PubMed

    Fowler, Drew A; Rathnayake, Asanka S; Kennedy, Stuart; Kumari, Harshita; Beavers, Christine M; Teat, Simon J; Atwood, Jerry L

    2013-08-21

    The synthesis and single-crystal X-ray diffraction structure of a dimeric zinc-seamed nanocapsule using a mixed pyrogallol/resorcinol[4]arene are presented. The use of "mixed" macrocycles results in an incomplete seam of coordination bonds around the nanocapsule's typically octa-metalated belt. The self-assembly of the nanocapsule occurs such that the single resorcinol moiety of each macrocycle aligns transversely. This yields a hepta-metalated capsule where the defect occurs in such a way as to provide minimal disruption to the overall structure of the nanocapsule.

  8. Detecting nonuniformity in small welds and solder seams using optical correlation and electronic processing.

    PubMed

    Wagner, J W

    1981-10-15

    Using holographic matched filtering and electronic processing, small variations in surface displacement along the seam of a hermetic microcircuit package can be detected when the seam is stressed. Destructive analysis of a solder-sealed package reveals a strong correlation between optical signal variations and nonuniformity of solder adhesion and wetting along the seam. The technique promises potential application as a means of nondestructively inspecting for flaws in small welded or soldered seams.

  9. Integration of vertical and in-seam horizontal well production analyses with stochastic geostatistical algorithms to estimate pre-mining methane drainage efficiency from coal seams: Blue Creek seam, Alabama.

    PubMed

    Karacan, C Özgen

    2013-07-30

    Coal seam degasification and its efficiency are directly related to the safety of coal mining. Degasification activities in the Black Warrior basin started in the early 1980s by using vertical boreholes. Although the Blue Creek seam, which is part of the Mary Lee coal group, has been the main seam of interest for coal mining, vertical wellbores have also been completed in the Pratt, Mary Lee, and Black Creek coal groups of the Upper Pottsville formation to degasify multiple seams. Currently, the Blue Creek seam is further degasified 2-3 years in advance of mining using in-seam horizontal boreholes to ensure safe mining. The studied location in this work is located between Tuscaloosa and Jefferson counties in Alabama and was degasified using 81 vertical boreholes, some of which are still active. When the current long mine expanded its operation into this area in 2009, horizontal boreholes were also drilled in advance of mining for further degasification of only the Blue Creek seam to ensure a safe and a productive operation. This paper presents an integrated study and a methodology to combine history matching results from vertical boreholes with production modeling of horizontal boreholes using geostatistical simulation to evaluate spatial effectiveness of in-seam boreholes in reducing gas-in-place (GIP). Results in this study showed that in-seam wells' boreholes had an estimated effective drainage area of 2050 acres with cumulative production of 604 MMscf methane during ~2 years of operation. With horizontal borehole production, GIP in the Blue Creek seam decreased from an average of 1.52 MMscf to 1.23 MMscf per acre. It was also shown that effective gas flow capacity, which was independently modeled using vertical borehole data, affected horizontal borehole production. GIP and effective gas flow capacity of coal seam gas were also used to predict remaining gas potential for the Blue Creek seam.

  10. Integration of vertical and in-seam horizontal well production analyses with stochastic geostatistical algorithms to estimate pre-mining methane drainage efficiency from coal seams: Blue Creek seam, Alabama

    PubMed Central

    Karacan, C. Özgen

    2015-01-01

    Coal seam degasification and its efficiency are directly related to the safety of coal mining. Degasification activities in the Black Warrior basin started in the early 1980s by using vertical boreholes. Although the Blue Creek seam, which is part of the Mary Lee coal group, has been the main seam of interest for coal mining, vertical wellbores have also been completed in the Pratt, Mary Lee, and Black Creek coal groups of the Upper Pottsville formation to degasify multiple seams. Currently, the Blue Creek seam is further degasified 2–3 years in advance of mining using in-seam horizontal boreholes to ensure safe mining. The studied location in this work is located between Tuscaloosa and Jefferson counties in Alabama and was degasified using 81 vertical boreholes, some of which are still active. When the current long mine expanded its operation into this area in 2009, horizontal boreholes were also drilled in advance of mining for further degasification of only the Blue Creek seam to ensure a safe and a productive operation. This paper presents an integrated study and a methodology to combine history matching results from vertical boreholes with production modeling of horizontal boreholes using geostatistical simulation to evaluate spatial effectiveness of in-seam boreholes in reducing gas-in-place (GIP). Results in this study showed that in-seam wells' boreholes had an estimated effective drainage area of 2050 acres with cumulative production of 604 MMscf methane during ~2 years of operation. With horizontal borehole production, GIP in the Blue Creek seam decreased from an average of 1.52 MMscf to 1.23 MMscf per acre. It was also shown that effective gas flow capacity, which was independently modeled using vertical borehole data, affected horizontal borehole production. GIP and effective gas flow capacity of coal seam gas were also used to predict remaining gas potential for the Blue Creek seam. PMID:26435557

  11. Series resistance effect on time zero dielectrics breakdown characteristics of MOSCAP with ultra-thin EOT high-k/metal gate stacks

    NASA Astrophysics Data System (ADS)

    Hao, Xu; Hong, Yang; Yanrong, Wang; Wenwu, Wang; Guangxing, Wan; Shangqing, Ren; Weichun, Luo; Luwei, Qi; Chao, Zhao; Dapeng, Chen; Xinyu, Liu; Tianchun, Ye

    2016-05-01

    The time zero dielectric breakdown characteristics of MOSCAP with ultra-thin EOT high-k metal gate stacks are studied. The TZDB results show an abnormal area dependence due to the series resistance effect. The series resistance components extracted from the Fowler-Nordheim tunneling relation are attributed to the spreading resistance due to the asymmetry electrodes. Based on a series model to eliminate the series resistance effect, an area acceleration dependence is obtained by correcting the TZDB results. The area dependence follows Poisson area scaling rules, which indicates that the mechanism of TZDB is the same as TDDB and could be considered as a trap generation process. Project supported by the National High Technology Research and Development Program (863 Program) of China (No. SS2015AA010601), the National Natural Science Foundation of China (Nos. 61176091, 61306129), and the Opening Project of the Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences.

  12. LCR circuit: new simple methods for measuring the equivalent series resistance of a capacitor and inductance of a coil

    NASA Astrophysics Data System (ADS)

    Ivković, Saša S.; Marković, Marija Z.; Ivković, Dragica Ž.; Cvetanović, Nikola

    2017-09-01

    Equivalent series resistance (ESR) represents the measurement of total energy loss in a capacitor. In this paper a simple method for measuring the ESR of ceramic capacitors based on the analysis of the oscillations of an LCR circuit is proposed. It is shown that at frequencies under 3300 Hz, the ESR is directly proportional to the period of oscillations. Based on the determined dependence of the ESR on the period, a method is devised and tested for measuring coil inductance. All measurements were performed using the standard equipment found in student laboratories, which makes both methods very suitable for implementation at high school and university levels.

  13. Electrode with transparent series resistance for uniform switching of optical modulation devices

    DOEpatents

    Tench, D. Morgan; Cunningham, Michael A.; Kobrin, Paul H.

    2008-01-08

    Switching uniformity of an optical modulation device for controlling the propagation of electromagnetic radiation is improved by use of an electrode comprising an electrically resistive layer that is transparent to the radiation. The resistive layer is preferably an innerlayer of a wide-bandgap oxide sandwiched between layers of indium tin oxide or another transparent conductor, and may be of uniform thickness, or may be graded so as to provide further improvement in the switching uniformity. The electrode may be used with electrochromic and reversible electrochemical mirror (REM) smart window devices, as well as display devices based on various technologies.

  14. Late blight resistance linkages in a novel cross of the wild potato species Solanum paucissectum (series Piurana).

    PubMed

    Villamon, F G; Spooner, D M; Orrillo, M; Mihovilovich, E; Pérez, W; Bonierbale, M

    2005-10-01

    The cultivated potato, Solanum tuberosum, is affected by a variety of diseases with late blight, caused by Phytophthora infestans, being the most severe. Wild potato species have proven to be a continuing source of resistance, sometimes of an extreme type, to this disease. The present study constructs the first late blight linkage map of a member of series Piurana, S. paucissectum, a tuber-bearing relative of potato, using probes for conserved sequences from potato and tomato. Eight probes mapped to unexpected linkage groups, but syntenic differences with prior maps of potato were not supported by any blocks of rearranged chromosome segments. All 12 linkage groups were resolved and significant associations with late blight resistance were found on chromosomes 10, 11 and 12. A major quantitative trait locus (QTL) on chromosome 11 accounts for more than 25% of the phenotypic variance measured in a field trial. Crossing of S. paucissectum with cultivated potato resulted in very few seeds indicating partial reproductive barriers. Differential reactions of accessions of this potential donor species with simple and complex isolates of P. infestans suggest that it carries major resistance genes that are not those previously described from the Mexican species, S. demissum. However, the additivity of the QTL effects argues for the quantitative nature of resistance in this cross.

  15. Military Curricula for Vocational & Technical Education. Basic Electricity and Electronics Individualized Learning System. CANTRAC A-100-0010. Module Twelve: Series AC Resistive-Reactive Circuits. Study Booklet.

    ERIC Educational Resources Information Center

    Chief of Naval Education and Training Support, Pensacola, FL.

    This individualized learning module on series alternating current resistive-reactive circuits is one in a series of modules for a course in basic electricity and electronics. The course is one of a number of military-developed curriculum packages selected for adaptation to vocational instructional and curriculum development in a civilian setting.…

  16. High School Students' Understanding of Resistance in Simple Series Electric Circuits.

    ERIC Educational Resources Information Center

    Liegeois, Laurent; Mullet, Etienne

    2002-01-01

    Studies the understanding that 8-12 grade high school students were able to develop with regard to the interrelationships between resistance, potential difference, and current concepts (Ohm's law). Explores the immediate effects of exposure to electricity courses on the intuitive mastery of these relationships. (Contains 32 references.)…

  17. High School Students' Understanding of Resistance in Simple Series Electric Circuits.

    ERIC Educational Resources Information Center

    Liegeois, Laurent; Mullet, Etienne

    2002-01-01

    Studies the understanding that 8-12 grade high school students were able to develop with regard to the interrelationships between resistance, potential difference, and current concepts (Ohm's law). Explores the immediate effects of exposure to electricity courses on the intuitive mastery of these relationships. (Contains 32 references.)…

  18. Pore pressure propagation in a permeable thin-layer coal seam based on a dual porosity model: A case of risk prediction of water inrush in coalmines

    NASA Astrophysics Data System (ADS)

    Zhu, B.; Gao, F.; Yang, J. W.; Zhou, G. Q.

    2016-08-01

    Thin-layer coal seams, a type of filling coal rock body, are considered aquifer systems made up of dual porosity medium with immediate floor. A numerical simulation for the pore pressure propagation along a thin-layer coal seam was carried out for the case of the Zhaogezhuang coalmine in China. By valuing the permeability (Kf ) of the thin-layer coal seam, pore pressure variation with time was simulated and compared to the analytical solutions of a dual porosity model (DPM). The main conclusions were drawn as follow: (1) Seepage in the thin-layer coal seam was predominant in the whole process, and the distance of seepage was lengthened and the pore pressure decreased with increased Kf , (2) A series of simulated hydraulic graphs demonstrated that the pore pressure characteristics of peak-occurring and time-lag effects agreed with the analytical solutions of DPM; (3) By adjusting the parameters of DPM, two results of analytical solutions and numerical solutions fit well, particularly in the thin-layer coal seam, (4) The power law relationship between the peak-values and lag time of pore pressure were derived statistically under consideration of the Kf parameter in the range of 10-8 to 10-10 m2/pa-s orders, and it was reasonable that the Kf of the thin-layer coal seam was in the range of 10-8 m2/pa-s orders. The results were significantly helpful in decision-making for mining water prevention and prediction in practice.

  19. A new protocol to accurately determine microtubule lattice seam location

    SciTech Connect

    Zhang, Rui; Nogales, Eva

    2015-09-28

    Microtubules (MTs) are cylindrical polymers of αβ-tubulin that display pseudo-helical symmetry due to the presence of a lattice seam of heterologous lateral contacts. The structural similarity between α- and β-tubulin makes it difficult to computationally distinguish them in the noisy cryo-EM images, unless a marker protein for the tubulin dimer, such as kinesin motor domain, is present. We have developed a new data processing protocol that can accurately determine αβ-tubulin register and seam location for MT segments. Our strategy can handle difficult situations, where the marker protein is relatively small or the decoration of marker protein is sparse. Using this new seam-search protocol, combined with movie processing for data from a direct electron detection camera, we were able to determine the cryo-EM structures of MT at 3.5. Å resolution in different functional states. The successful distinction of α- and β-tubulin allowed us to visualize the nucleotide state at the E-site and the configuration of lateral contacts at the seam.

  20. A new protocol to accurately determine microtubule lattice seam location

    DOE PAGES

    Zhang, Rui; Nogales, Eva

    2015-09-28

    Microtubules (MTs) are cylindrical polymers of αβ-tubulin that display pseudo-helical symmetry due to the presence of a lattice seam of heterologous lateral contacts. The structural similarity between α- and β-tubulin makes it difficult to computationally distinguish them in the noisy cryo-EM images, unless a marker protein for the tubulin dimer, such as kinesin motor domain, is present. We have developed a new data processing protocol that can accurately determine αβ-tubulin register and seam location for MT segments. Our strategy can handle difficult situations, where the marker protein is relatively small or the decoration of marker protein is sparse. Using thismore » new seam-search protocol, combined with movie processing for data from a direct electron detection camera, we were able to determine the cryo-EM structures of MT at 3.5. Å resolution in different functional states. The successful distinction of α- and β-tubulin allowed us to visualize the nucleotide state at the E-site and the configuration of lateral contacts at the seam.« less

  1. Palaeoenvironmental reconstruction of Hüsamlar coal seam, SW Turkey

    NASA Astrophysics Data System (ADS)

    Büçkün, Zeynep; İnaner, Hülya; Oskay, Riza Görkem; Christanis, Kimon

    2015-06-01

    The Ören and Yatağan Basins in SW Turkey host several Miocene coal deposits currently under exploitation for power generation. The present study aims to provide insight into the palaeoenvironmental conditions, which controlled the formation of the Hüsamlar coal seam located in Ören Basin. The coal seam displays many sharp alternations of matrix lignite beds and inorganic, lacustrine sediment layers. The coal is a medium-to-high ash lignite (10.47-31.16 wt%, on dry basis) with high total sulphur content (up to 10 wt%, on dry, ash-free basis), which makes it prone to self-combustion. The maceral composition indicates that the peat-forming vegetation consisted of both arboreal and herbaceous plants, with the latter being predominant in the upper part of the seam. Mica and feldspars contribute to the low part of the seam; carbonates are dominant in the upper part, whereas quartz and pyrite are present along the entire coal profile. The sudden transitions of the telmatic to the lacustrine regime and reverse is attributed to tectonic movements that controlled water table levels in the palaeomire, which affected surface runoff and hence, clastic deposition.

  2. Automatic laser welding of metal bellows with precision seam tracker

    SciTech Connect

    Chang, D.U.

    1996-12-31

    Metal bellows were laser edge-welded satisfactorily with the aid of a precision seam tracking system. The welding speed was five to ten times faster than conventional arc welding. The weld quality was excellent and the cost savings are expected to be substantial.

  3. Spatial Variation of Selenium in Appalachian Coal Seams

    NASA Astrophysics Data System (ADS)

    Le, L.; Tyner, J. S.; Perfect, E.; Yoder, D. C.

    2013-12-01

    The potential environmental impacts from coal extraction have led to many investigations of the geochemistry of coal. Previous studies have shown that selenium (Se) is an environmental contaminant due to its mutagenic effects on sensitive macro-organisms as a result of bioaccumulation in affected waters. Some regulatory authorities have responded by requiring the sampling of coal seams and adjacent rock for Se prior to authorizing a given coal mining permit. In at least one case, a single continuous rock core was sampled for Se to determine the threshold of Se across a 2.2 square kilometer proposed surface coal mine. To examine the adequacy of such an approach, we investigated the spatial variability and correlation of a West Virginia Geological and Economic Survey (WVGES) dataset of Se concentrations from coal seams collected within Appalachia (1088 samples). We conducted semi-variogram and Kriging cross-validation analyses on six coal seams from the dataset. Our findings suggest no significant spatial correlation of Se within a given coal seam.

  4. Entrapment of elusive guests within metal-seamed nanocapsules.

    PubMed

    Kumari, Harshita; Jin, Ping; Teat, Simon J; Barnes, Charles L; Dalgarno, Scott J; Atwood, Jerry L

    2014-11-24

    Anions play a crucial role in locking alkali metals on the interior of metal-organic capsules that contain structural water gates. This role is further evidenced when stitching-up the capsule seam, resulting in either expulsion or trapping of cesium ions depending on the anion employed.

  5. 49 CFR 230.30 - Lap-joint seam boilers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Lap-joint seam boilers. 230.30 Section 230.30 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances...

  6. 49 CFR 230.30 - Lap-joint seam boilers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Lap-joint seam boilers. 230.30 Section 230.30 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances...

  7. Detail of masonry seam in southwest elevation, between original house ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of masonry seam in southwest elevation, between original house and Federal addition; also simulated ashlar finish of Federal addition underneath current stucco. Left window unaltered from original house. - Scheetz Farm, House, 7161 Camp Hill Road, Fort Washington, Montgomery County, PA

  8. Combined time-series resistivity and geochemical tracer techniques to examine submarine groundwater discharge at Dor Beach, Israel

    USGS Publications Warehouse

    Swarzenski, P.W.; Burnett, W.C.; Greenwood, W.J.; Herut, B.; Peterson, R.; Dimova, N.; Shalem, Y.; Yechieli, Y.; Weinstein, Y.

    2006-01-01

    A high-resolution, stationary geophysical and geochemical survey was conducted at Dor Beach, Israel, to examine the shallow coastal hydrogeology and its control on the exchange of submarine groundwater with the shallow Mediterranean Sea. Time-series resistivity profiles using a new 56 electrode (112-m long) marine cable produced detailed profiles of the fresh water/salt water interface and the subtle response of this interface to tidal excursions and other forcing factors. Such information, when ground-truthed with representative pore water salinities and formation resistivity values, can provide unique information of the extent and rates of submarine groundwater discharge (SGD). Time-series 222Rn measurements of the adjacent coastal water column complemented these geophysical techniques and were modeled to yield integrated advective flow rates across the sediment/water interface, which at Dor Beach ranged from about 0 to 30 cm day-1 (mean = 7.1 cm d-1), depending on the tidal range. Such results suggest that the underlying hydrogeologic framework at Dor is favorable for substantial SGD. Extrapolating these SGD estimates across a 100-m wide coastal zone implies that the Rn-derived SGD rate would equal ???7.1 m3 d-1 per m of shoreline, and that the source of this discharging groundwater is a complex mixture of fresh groundwater derived from the upland Kurkar deposits, as well as locally recycled seawater. Copyright 2006 by the American Geophysical Union.

  9. Subsidence resulting from multiple-seam longwall mining in the western United States

    SciTech Connect

    Dyni, R.C.

    1991-01-01

    This paper details the investigation of multiple-seam longwall subsidence conducted by the U.S. Bureau of Mines from 1978 to 1989. A field investigation monitored ground surface movements over four upper seam longwall panels and six lower seam panels. The characteristics of the subsidence occurring as a result of mining these panels are examined: in particular, the angle of draw, subsidence development, total magnitude and areal extent, and critical width are evaluated and discussed. comparisons are also made between the characteristics of multiple-seam longwall subsidence and single-seam longwall subsidence that occurred at the same site.

  10. Effects of fluoroquinolone restriction (from 2007 to 2012) on resistance in Enterobacteriaceae: interrupted time-series analysis.

    PubMed

    Sarma, J B; Marshall, B; Cleeve, V; Tate, D; Oswald, T; Woolfrey, S

    2015-09-01

    Antibiotic stewardship is a key component in the effort to reduce healthcare-associated infections. To describe the implementation and analyse the impact of fluoroquinolone restriction on resistance in Enterobacteriaceae, focusing on urinary isolates of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli, which were historically almost universally resistant to fluoroquinolones. ESBL-producing E. coli hospital and community isolates, obtained between April 2009 and March 2012 from consecutive non-duplicate urine samples, were included in an interrupted time-series analysis based on a Poisson distribution model. Periods before and after fluoroquinolone restriction were compared. The trend in fluoroquinolone resistance in all urinary isolates of Enterobacteriaceae (N ≈ 20,000 per year) and blood culture isolates of E. coli (N ≈ 350) between 2009 and 2013 were also analysed. A large decline in the percentage of ciprofloxacin-resistant ESBL-producing urinary E. coli isolates was observed in both hospital (risk ratio: 0.473; 95% confidence interval: 0.315-0.712) and community settings (0.098; 0.062-0.157). The decline was also marked in all urinary isolates of Enterobacteriaceae and E. coli isolates from blood cultures. We conclude that reducing fluoroquinolone usage to a level of ≤2 defined daily doses per 100 occupied bed-days in hospital sufficiently removed selection pressure to allow resistant Enterobacteriaceae – specifically, the UK endemic strains of ESBL-producing E. coli – to revert back to fluoroquinolone susceptibility within a short span of four months. This was accompanied with a concomitant reduction in overall ESBL burden. Copyright © 2015 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  11. In-mine geoelectric investigations for detecting tectonic disturbances in coal seam structures

    NASA Astrophysics Data System (ADS)

    Gyulai, Ákos; Dobróka, Mihály; Ormos, Tamás; Turai, Endre; Sasvári, Tibor

    2013-10-01

    The methods of in-mine seam-sounding and transillumination (geoelectric tomography) for the detection of tectonic disturbances of coal seams were developed by the Department of Geophysics of the University of Miskolc in the 1970-80's with the effective support of the former "Borsod" Coal Mines Ltd. The paper gives an overview about the theory of seam-sounding and a special geoelectric tomographic inversion, and introduces the in-mine geoelectric seam-sounding and transillumination measurement systems using vertical electrode dipoles. In the second part the paper, the results of an in-mine geoelectric measurement are presented, which was carried out in order to detect tectonic disturbances of the Miocene aged coal seams situated in Slovakia. As results of the geophysical investigation, the authors forecasted the tectonic features in the coal seam. The company confirmed the results by independent information about seam disturbances and tectonic features arising from the excavation of the investigated area.

  12. Experimental dynamical characterization of five autonomous chaotic oscillators with tunable series resistance

    SciTech Connect

    Minati, Ludovico E-mail: ludovico.minati@unitn.it

    2014-09-01

    In this paper, an experimental characterization of the dynamical properties of five autonomous chaotic oscillators, based on bipolar-junction transistors and obtained de-novo through a genetic algorithm in a previous study, is presented. In these circuits, a variable resistor connected in series to the DC voltage source acts as control parameter, for a range of which the largest Lyapunov exponent, correlation dimension, approximate entropy, and amplitude variance asymmetry are calculated, alongside bifurcation diagrams and spectrograms. Numerical simulations are compared to experimental measurements. The oscillators can generate a considerable variety of regular and chaotic sine-like and spike-like signals.

  13. An in vitro comparison of cyclic fatigue resistance of ProTaper universal and GT series x files

    PubMed Central

    Montenegro-Santillán, Ramiro; Alegre-Domingo, Teresa; Faus-Matoses, Vicente

    2013-01-01

    Objective: The aim of this study was to compare the cyclic fatigue resistance of two nickel-titanium (NiTi) endodontic instruments from ProTaper and GT series X files. Study Design: Cyclic fatigue test was realized with instruments from ProTaper: F1 and F3 (Denstply Maillefer, Ballaigues, Switzerland) and GT-X: 20.06 and 30.08 (Dentsply Tulsa Dental, Tulsa, Oklahoma, United States of America). A total of 320 instruments were rotated in 4 curved artificial canals with different angles and radius of curvature. The time and cycles to failure were calculated. The data was compared using a Mann-Whitney, Kruskall-Wallis, and Kolmogorov-Smirnov tests, with a significance level of p<0.05. Results: GT-X files rotated for a significantly longer period of time before separation occurred, thus GT-X files where more resistant to the cyclic fatigue compared with ProTaper. Conclusion: GT-X files have a greater resistance to cyclic fatigue, this fact can be caused by the use of the Ni-Ti alloy “M-Wire”. Key words:Endodontics, GT-X files, ProTaper files, cyclic fatigue. PMID:23385505

  14. Enhancing Fracture and Wear Resistance of Dentures/Overdentures Utilizing Digital Technology: A Case Series Report.

    PubMed

    Afify, Ahmed; Haney, Stephan

    2016-08-01

    Since it was first introduced into the dental world, computer-aided design/computer-aided manufacturing (CAD/CAM) technology has improved dramatically in regards to both data acquisition and fabrication abilities. CAD/CAM is capable of providing well-fitting intra- and extraoral prostheses when sound guidelines are followed. As CAD/CAM technology encompasses both surgical and prosthetic dental applications as well as fixed and removable aspects, it could improve the average quality of dental prostheses compared with the results obtained by conventional manufacturing methods. The purpose of this article is to provide an introduction into the methods in which this technology may be used to enhance the wear and fracture resistance of dentures and overdentures. This article will also showcase two clinical reports in which CAD/CAM technology has been implemented.

  15. Patients presenting with miliaria while wearing flame resistant clothing in high ambient temperatures: a case series

    PubMed Central

    2011-01-01

    Introduction Clothing can be a cause of occupational dermatitis. Frequent causes of clothing-related dermatological problems can be the fabric itself and/or chemical additives used in the laundering process, friction from certain fabrics excessively rubbing the skin, or heat retention from perspiration-soaked clothing in hot working environments. To the best of our knowledge, these are the first reported cases of miliaria rubra associated with prolonged use of flame resistant clothing in the medical literature. Case presentation We report 18 cases (14 men and 4 women, with an age range of 19 to 37 years) of moderate to severe skin irritation associated with wearing flame resistant clothing in hot arid environments (temperature range: 39 to 50°C, 5% to 25% relative humidity). We describe the medical history in detail of a 23-year-old Caucasian woman and a 31-year-old African-American man. A summary of the other 16 patients is also provided. Conclusions These cases illustrate the potential serious nature of miliaria with superimposed Staphylococcus infections. All 18 patients fully recovered with topical skin treatment and modifications to their dress ensemble. Clothing, in particular blend fabrics, must be thoroughly laundered to adequately remove detergent residue. While in hot environments, individuals with sensitive skin should take the necessary precautions such as regular changing of clothing and good personal hygiene to ensure that their skin remains as dry and clean as possible. It is also important that they report to their health care provider as soon as skin irritation or rash appears to initiate any necessary medical procedures. Miliaria rubra can take a week or longer to clear, so removal of exposure to certain fabric types may be necessary. PMID:21939537

  16. Delineation of Surface-Groundwater Interactions Using Statistical Analysis of Temperature Time-Series and Resistivity Methods

    NASA Astrophysics Data System (ADS)

    Scotch, C. G.; Murgulet, D.; Hay, R.

    2013-12-01

    Although surface-water and groundwater are often referred to as separate domains, they are intimately related as a change in one domain can ultimately affect the other domain. Since the two domains act as linked pathways for contaminant transport in the hydrologic cycle a comprehensive understanding of this relationship is essential for improved SW-GW management practices. The main objective of this study is to develop new statistical methods to better identify and characterize the advective component or water movement between SW-GW in a coastal area along the South Texas coast, adjacent to the Gulf of Mexico (GOM) margin, characterized by low gradients and low-conductivity stream beds. Identifying advection zones using temperature data in regions with low topographic relief and numerous small-scale flow paths is difficult. To overcome this challenge this study proposes the use of seasonal-trend decomposition (STL) of time series temperature data to analyze exchanges in this type of environment. Seasonal decomposition analysis was used to remove the daily and annual cyclic components leaving the random or non-cyclic component. It can be inferred that high variances of the random component indicate periods of advection. This statistically-derived advective component correlates well with advection periods identified from the conventional time-series temperature profile analysis. This correlation is a good validation of the statistical approach as means of identifying periods of advection and SW-GW interaction. Electrical resistivity imaging will be used for validation of the statistical model.

  17. Liver pathology in severe multidrug resistant 3 protein deficiency: a series of 10 pediatric cases.

    PubMed

    Vij, Mukul; Safwan, Mohamed; Shanmugam, Naresh P; Rela, Mohamed

    2015-10-01

    Multidrug resistance protein 3 (MDR3) is a hepatocyte canalicular membrane protein encoded by the ABCB4/MDR3 gene located on chromosome 7. Several liver diseases are known to be associated with MDR3 deficiency. The basic defect is reduced secretion of biliary phospholipid causing disturbance in the primary bile composition, leading to injury to biliary epithelium inducing cell death and inflammation. Severe MDR3 deficiency typically presents during the first year of life or early childhood, often progressing to chronic liver disease with cirrhosis and portal hypertension, requiring liver transplantation. Negative MDR3 immunostaining is suggestive of MDR3 deficiency. Herein, we report the clinical and histopathologic features of 10 cases (6 male/4 female) in infants and children with severe MDR3 deficiency (age range of 8 months to 7 years) diagnosed with negative MDR3 immunostaining in hepatic canaliculi. Three cases underwent liver transplantation. The cases showed periportal bridging fibrosis to micronodular cirrhosis, ductular proliferation with bile plugs, and lobular canalicular bile stasis with rosetting. All 3 explant livers demonstrated cystically dilated large ducts with crystallization of cholesterol. One case showed well-differentiated hepatocellular carcinoma. We conclude that MDR3 immunostaining on formalin-fixed and paraffin-embedded sections is a useful tool to diagnose severe MDR3 deficiency in pediatric liver cholestatic disease cases where genetic testing is not available. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Mathematical modeling of hydraulic fracturing in coal seams

    SciTech Connect

    Olovyanny, A.G.

    2005-02-01

    Hydraulic fracturing of coal seam is considered as a process of development of discontinuities in rock mass elements due to change in hydrogeomechanical situation on filtration of fluid under pressure. Failure is associated with excess of the effective stresses over the rock tension strength. The problem on filtration and failure of massif is solved by the finite-element method using the procedure of fictitious nodal forces.

  19. Numerical modeling of hydrofracturing in a multilayer coal seam

    SciTech Connect

    Nasedkina, A.A.; Trufanov, V.N.

    2006-01-15

    The mathematical model of the process for hydrodynamic fracturing in a multilayer coal seam is proposed. The model is based on the equation of continuity and Darcy's law. The filtration-temperature analogy allows solving the obtained non-linear, non-stationary problem in an axisymmetric statement for the pressure function as the heat-conductivity problem, by the finite-element method. The calculation results yield estimation of the radius of degassing borehole influence zone.

  20. An adaptive sliding mode control technology for weld seam tracking

    NASA Astrophysics Data System (ADS)

    Liu, Jie; Hu, Youmin; Wu, Bo; Zhou, Kaibo; Ge, Mingfeng

    2015-03-01

    A novel adaptive sliding mode control algorithm is derived to deal with seam tracking control problem of welding robotic manipulator, during the process of large-scale structure component welding. The proposed algorithm does not require the precise dynamic model, and is more practical. Its robustness is verified by the Lyapunov stability theory. The analytical results show that the proposed algorithm enables better high-precision tracking performance with chattering-free than traditional sliding mode control algorithm under various disturbances.

  1. Top coal caving longwall maximizes thick seam recovery

    SciTech Connect

    Duncan, G.; Sobey,. G.; Clarke, T.

    2007-07-15

    Austar's longwall system offers opportunities in coal seams thicker than 4.5 meters. The Longwall Top Coal Caving (LTCC) method was recently launched in Australia at Yancoal Australia's Austar mines in Hunter Valley, although 90 such longwalls already operate in China. The article describes the method and its installation at Austar. In September 2006 the LTCC face commenced production. The operation is described and measures to prevent spontaneous combustion are outlined. Future work on the longwall is mentioned. 11 figs.

  2. Series resistance effects in La0.5Ca0.5MnO3/SrTiO3:Nb(0 0 1) heterojunctions

    NASA Astrophysics Data System (ADS)

    Wang, J. F.; Cao, D.; Zhou, Y.; Wang, X. Y.; Jiao, Z. W.; Gao, J.

    2015-09-01

    The effects of series resistance in heterojunctions composed of La0.5Ca0.5MnO3 (LCMO) and Nb:SrTiO3 with 0.05 wt.% and 0.7 wt.% of Nb doping (0.05NbSTO and 0.7NbSTO) have been investigated in detail using current-voltage curves with and without light illumination. Two linear plots, namely, dV/dlnJ versus J and H(J)[≡V-(nk B T/q)ln(J/A**T 2)] versus J, have been used to extract the series resistance. These two plots give very close values. The extracted series resistance exhibits a monotonous increase with decreasing temperatures, which could explain the observed anomalous temperature dependence of short circuit current in LCMO/0.7NbSTO.

  3. Sulfate Reduction at a Lignite Seam: Microbial Abundance and Activity.

    PubMed

    Detmers, J.; Schulte, U.; Strauss, H.; Kuever, J.

    2001-10-01

    In a combined isotope geochemical and microbiological investigation, a setting of multiple aquifers was characterized. Biologically mediated redox processes were observed in the aquifers situated in marine sands of Tertiary age and overlying Quaternary gravel deposits. Intercalated lignite seams define the aquitards, which separate the aquifers. Bacterial oxidation of organic matter is evident from dissolved inorganic carbon characterized by average carbon isotope values between ?18.4 per thousand and ?15.7 per thousand (PDB). Strongly positive sulfur isotope values of up to +50 per thousand (CTD) for residual sulfate indicate sulfate reduction under closed system conditions with respect to sulfate availability. Both, hydrochemical and isotope data are thus consistent with the recent activity of sulfate-reducing bacteria (SRB). Microbiological investigations revealed the presence of an anaerobic food chain in the aquifers. Most-probable-number (MPN) determinations for SRB and fermenting microorganisms reached highest values at the interface between aquifer and lignite seam (1.5 x 103 cells/g sediment dry mass). Five strains of SRB were isolated from highest MPN dilutions. Spore-forming bacteria appeared to dominate the SRB population. Sulfate reduction rates were determined by the 35S-radiotracer method. A detailed assessment indicates an increase in the reduction rate in proximity to the lignite seam, with a maximum turnover of 8.4 mM sulfate/a, suggesting that lignite-drived compounds represent the substrate for sulfate reduction.

  4. Cleaning of Croweburg Seam coal to improve boiler performance

    SciTech Connect

    Dospoy, R.L.

    1991-01-01

    Recently an Oklahoma law was enacted that mandates that Oklahoma coal-fired utilities must burn a minimum of ten percent Oklahoma-mined coal. Public Service Company of Oklahoma (PSO), burning raw Croweburg Seam coal from Oklahoma as part of a blend, was interested in determining if cleaning the Croweburg Seam coal could reduce boiler slagging and fouling problems experienced at its Northeastern Station's Units 3 and 4. Studies of the Croweburg Seam coal performed at CQ Inc. in Homer City, Pennsylvania were used to determine the potential of physical cleaning for upgrading this coal. The test program involved commercial-scale cleaning tests with heavy-medium cyclones, two-stage water only cyclones, and froth flotation cells, well as extensive laboratory and pilot-scale tests. The coal evaluated during the test program responded well to cleaning. Results indicate the ash slagging and fouling can be significantly improved by cleaning. Significant reductions in ash, specific ash constituents, and trace element concentrations were also demonstrated along with increased heating value. Finally, although the raw coal tested can be classified as compliance'' prior to cleaning, the cleaning tests show that further reductions in SO{sub 2} emissions potential were possible, along with high energy recoveries and increased heating values and can be beneficial for improved plant performance.

  5. Selective agglomeration of a Pittsburgh Seam coal with isooctane

    SciTech Connect

    Lai, R.; Killmeyer, R.; Utz, B.; Richardson, A.; Sinha, K.

    1992-01-01

    The Pittsburgh Energy Technology Center initiated a research program in 1989 to investigate the fundamentals of selective agglomeration as applied to the cleaning of coals. The results of the initial study with Bruceton mine, Pittsburgh seam coal, using isooctane as an agglomerant, have been published. Subsequent to the successful reduction of the ash content of Bruceton coal to less than 0.9% after two cleaning stages, the study was extended to compare a coal from the same seam, but from Ohio. In the previous parameter optimization tests with Bruceton coal, particle size and slurry pH were found to be important parameters governing coal cleanability. Other researchers have obtained similar conclusions of the effects of particle size and coal slurry pH on the cleanability of various coals. In this study, the effects of these parameters on the cleanability of Powhatan coal were examined. Particle size reduction kinetics was examined first. Effects of size reduction (degree of mineral matter liberation), oil (isooctane)-to-coal ratio, and slurry pH on mineral matter rejection and combustible recovery were also examined. A petrographic comparison was conducted on the Powhatan and Bruceton coals to examine the degree of pyrite liberation as a function of particle size to elucidate why one coal from the same seam can be cleaned significantly better than another. (VC)

  6. Classification of coal seam outburst hazards and evaluation of the importance of influencing factors

    NASA Astrophysics Data System (ADS)

    Shi, Xianzhi; Song, Dazhao; Qian, Ziwei

    2017-07-01

    Coal and gas outbursts are the result of several geological factors related to coal seam gas (coal seam gas pressure P, coal seam sturdiness coefficient f and coal seam gas content W), and these parameters can be used to classify the outburst hazard level of a coal seam. To classify the outburst hazard level of a coal seam by means of statistical methods, this study considered the geological parameters of coal seam gas and statistical data on the amount of material involved in coal outbursts. Through multivariate regression analysis, a multivariate regression equation between the outburst coal quantity and P, f and W was established. Using a significance evaluation of the aforementioned factors, the relative contributions of the gas-related geological parameters to the outburst hazard level of a coal seam were found to follow the order P>f>W. This work provides a scientific basis for evaluating the outburst hazard level of a coal seam and adopting feasible and economical outburst-prevention measures.

  7. Definition of Locked-up Stresses around a Rectilinear Welding Seam

    NASA Astrophysics Data System (ADS)

    Velikanov, N. L.; Koryagin, S. I.; Sharkov, O. V.

    2016-04-01

    In article one of the ways of modelling of the locked-up stresses caused by imposing of a welding seam in a plate is described. These stresses are caused by residual deformations of welding seams. In the settlement scheme the welding seam is presented in the form of an element by the thickness equal to the thickness of a plate, inserted in it with a longitudinal and cross-section tightness. The field of locked-up stresses around the welding seam experiences longitudinal and cross-section shrinkage under cooling and it is defined in work with the use of complex potentials of the theory of elasticity.

  8. Predictions of fire behavior and resistance to control: for use with photo series for the sierra mixed conifer type and the sierra true fir type.

    Treesearch

    Franklin R. Ward; David V. Sandberg

    1981-01-01

    This publication presents tables on the behavior of fire and the resistance: of fuels to control. The information is to be used with the photos in the publication, "Photo Series for Quantifying Forest Residues in the Sierra Mixed Conifer Type, Sierra True Fir Type" (Maxwell, Wayne G.; Ward, Franklin R. 1979. Gen. Tech. Rep. PNW-GTR-095. Portland, OR: U.S....

  9. Predictions of fire behavior and resistance to control: for use with photo series for the ponderosa pine type, ponderosa pine and associated species type, and lodgepole pine type.

    Treesearch

    Franklin R. Ward; David V. Sandberg

    1981-01-01

    This publication presents tables on the behavior of fire and the resistance of fuels to control. The information is to be used with the publication, "Photo Series for Quantifying Forest Residues in the Ponderosa Pine Type, Ponderosa Pine and Associated Species Type, Lodgepole Pine Type" (Maxwell, Wayne G.; Ward, Franklin R. 1976. Gen. Tech. Rep. PNW-GTR-052....

  10. Chemistry and palynology of carbon seams and associated rocks from the Witwatersrand goldfields, South Africa

    USGS Publications Warehouse

    Ebert, L.B.; Robbins, E.I.; Rose, K.D.; Kastrup, R.V.; Scanlon, J.C.; Gebhard, L.A.; Garcia, A.R.

    1990-01-01

    Carbon seams in the Witwatersrand System of South Africa host some of the richest gold concentrations in the world. A study of the microscopic characteristics in thin sections and acid residues, and of the chemical and physical nature of the carbon-bearing phases, was undertaken to gain some understanding of the biological precursors and thermal changes that have occurred since the seams were buried. The HClHF acid-resistant organic tissues in this Early Proterozoic coal are filamentous and spherical, which are typical morphologies for microorganisms. The tissues are carbonized black as would be expected for metamorphic rocks, so usual palynological techniques were of limited use. Therefore, the chemical and physical nature of the organic remains was studied by H C ratios, X-ray diffraction (XRD), 13C nuclear magnetic resonance (NMR), reductive chemistry, crosspolarization/magic angle spinning NMR (CP/MAS), and electron spin resonance (ESR). The H C ratios of the samples examined are similar to those of semi-anthracite and petroleum cokes from delayed cokers. XRD shows graphite is not present and that the gold is in elemental form, not chemically bound or intercalated between carbon planes. NMR shows that both aromatic and paraffinic carbons are present. Integration of the carbon NMR spectra suggests that 80% of the carbon is sp2-hybridized and 20% is sp3-hybridized. Reductive chemistry shows that the benzenoid entities are larger than common polynuclear aromatic hydrocarbons such as perylene and decacyclene. Dipolar dephasing CP/MAS NMR suggests the presence of two types of paraffinic carbons, a rigid methylene group and a rotating methyl group. The narrowing of the ESR linewidth between room temperature and 300??C shows that the materials examined have not previously been subjected to temperatures as high as 300??C. ?? 1990.

  11. Deep coal seams as a greener energy source: a review

    NASA Astrophysics Data System (ADS)

    Ranathunga, A. S.; Perera, M. S. A.; Ranjith, P. G.

    2014-12-01

    Today, coal and oil are the main energy sources used in the world. However, these sources will last for only a few decades. Hence, the investigation of possible energy sources to meet this crisis has become a crucial task. Coal bed methane (CBM) is a potential energy source which can be used to fulfil the energy demand. Since the amount of carbon dioxide (CO2) emitted to the atmosphere from the use of CBM is comparatively very low compared to conventional energy sources, it is also a potential mitigation option for global warming. This paper reviews CBM recovery techniques with particular emphasis on CO2-enhanced coal bed methane (CO2-ECBM) recovery. The paper reviews (1) conventional CBM recovery techniques and problems associated with them, (2) CBM production-enhancement methods, including hydro-fracturing and enhanced CBM recovery techniques, such as N2-ECBM and CO2-ECBM, (3) the importance of the CO2-ECBM technique compared to other methods and problems with it, (4) the effect of CO2 injection during the CO2-ECBM process on coal seam permeability and strength and (5) current CO2-ECBM field projects and their progress. Although conventional CBM recovery methods are simple (basically related to the drawdown of the reservoir pressure to release methane from it), they are inefficient for the recovery of a commercially viable amount of methane from coal seams. Therefore, to enhance methane production, several methods are used, such as hydro-fracturing and ECBM (N2-ECBM and CO2-ECBM). The CO2-ECBM process has a number of advantages compared to other methane recovery techniques, as it contributes to the mitigation of the atmospheric CO2 level, is safer and more economical. However, as a result of CO2 injection into the coal seam during the CO2-ECBM process, coal mass permeability and strength may be crucially changed, due to the coal matrix swelling associated with CO2 adsorption into the coal matrix. Both injecting CO2 properties (gas type, CO2 phase and pressure

  12. Introducing dolomite seams: hybrid compaction-dissolution bands in dolomitic limestones

    NASA Astrophysics Data System (ADS)

    Tavani, Stefano; Vitale, Stefano; Grifa, Celestino; Iannace, Alessandro; Parente, Mariano; Mazzoli, Stefano

    2016-04-01

    Anastomosing dolomite seams occur at different stratigraphic levels of a clay-poor Mesozoic carbonate platform succession of the Apennines. Millimeter-thick seams, roughly parallel to bedding, are composed of a high concentration of dolomite crystals compared to the hosting dolomitic limestone micrite. Rare calcite veins emanating from the seams are observed in thin-section, while m-thick micro-stylolites frequently occur within the seams. Veins and micro-stylolites are perpendicular and parallel to the dolomite seams, respectively. Scanning electron microscope images and energy dispersive x-ray spectroscopy analysis document crushing and fragmentation of dolomite crystals, and accumulation of non-carbonate insoluble material along stylolites and around dolomite crystals of the seams. All these features suggest that the described seams are hybrid structures between pressure dissolution seams and compaction bands, and formed parallel to bedding during sedimentary burial. The dolomite crystals scattered in the micritic matrix represent the main body of the insoluble residue produced by the progressive dissolution of calcite. As calcite dissolution proceeds, the concentration of dolomite crystals increases, eventually resulting in a dolomite seam in which locally a dolomite crystal-supported texture is attained. At this stage, the dolomite crystals within the seam start to collide, crush and fragment, so that the dolomite seam behaves like a compaction band for high dolomite crystals concentrations. This new type of compaction structure is likely to be widespread in clay-poor dolomitic limestones, where it may have a significant role in controlling syn-burial porosity evolution and post-dolomitization calcite to dolomite ratio decrease.

  13. Aqueous Seams in the Small Moons of Saturn and Uranus

    NASA Astrophysics Data System (ADS)

    England, C.

    2002-12-01

    Eight small moons of Saturn and Uranus have a size and mass sufficient to have formed, and possibly maintained, an aqueous seam between a radiogenic rocky core and an insulating icy mantle. Analysis of thermal conduction in a composite sphere indicates that, at radiogenic rates typical of chondritic meteorites, four of these moons could maintain thin oceans even without tidal or other uncharacterized internal heating. If the radiogenic rate of rocky outer-planetary material is characteristic of the returned Lunar samples, which is about double the chondritic rate, aqueous seams may have formed in all eight moons as well as in Triton and Pluto, and could be maintained to the present day. Trans-Neptunian Objects with radii greater than 910 km are also candidates for thin oceans, the minimum radius reduced to 720 km if Lunar radiogenic rates are assumed. The assumption of differentiation of rock and ice in smaller bodies is supported by the high radiogenic rates during the formation of the Solar System. The melting point of icy materials was easily exceeded, leading to their outward flow and the corresponding concentration of radiogenic material in the core. Bodies with a density of about 1750 kg/m3 have the best proportion of ice and rock that balances the insulating value of the former with the heat production of the latter. Lower density bodies with higher water content such as Rhea may be more easily differentiated and therefore more likely to form and maintain an ocean. The presence of low-viscosity seams can be a major influence on the character and dissipation of tidal energy.

  14. Apparatus and process for ultrasonic seam welding stainless steel foils

    DOEpatents

    Leigh, Richard W.

    1992-01-01

    An ultrasonic seam welding apparatus having a head which is rotated to form contact, preferably rolling contact, between a metallurgically inert coated surface of the head and an outside foil of a plurality of layered foils or work materials. The head is vibrated at an ultrasonic frequency, preferably along a longitudinal axis of the head. The head is constructed to transmit vibration through a contacting surface of the head into each of the layered foils. The contacting surface of the head is preferably coated with aluminum oxide to prevent the head from becoming welded to layered stainless steel foils.

  15. Modeling of CO 2 sequestration in coal seams: Role of CO 2 -induced coal softening on injectivity, storage efficiency and caprock deformation: Original Research Article: Modeling of CO 2 sequestration in coal seams

    DOE PAGES

    Ma, Tianran; Rutqvist, Jonny; Liu, Weiqun; ...

    2017-01-30

    An effective and safe operation for sequestration of CO 2 in coal seams requires a clear understanding of injection-induced coupled hydromechanical processes such as the evolution of pore pressure, permeability, and induced caprock deformation. In this study, CO 2 injection into coal seams was studied using a coupled flow-deformation model with a new stress-dependent porosity and permeability model that considers CO 2 -induced coal softening. Based on triaxial compression tests of coal samples extracted from the site of the first series of enhanced coalbed methane field tests in China, a softening phenomenon that a substantial (one-order-of-magnitude) decrease of Young's modulusmore » and an increase of Poisson's ratio with adsorbed CO 2 content was observed. Such softening was considered in the numerical simulation through an exponential relation between elastic properties (Young's modulus and Poisson's ratio) and CO 2 pressure considering that CO 2 content is proportional to the CO 2 pressure. Our results of the numerical simulation show that the softening of the coal strongly affects the CO 2 sequestration performance, first by impeding injectivity and stored volume (cumulative injection) during the first week of injection, and thereafter by softening mediated rebound in permeability that tends to increase injectivity and storage over the longer term. A sensitivity study shows that stronger CO2 -induced coal softening and higher CO 2 injection pressure contribute synergistically to increase a significant increase of CO 2 injectivity and adsorption, but also result in larger caprock deformations and uplift. This study demonstrates the importance of considering the CO 2 -induced softening when analyzing the performance and environmental impact of CO 2 -sequestration operations in unminable coal seams.« less

  16. Five-Year Antimicrobial Resistance Patterns of Urinary Escherichia coli at an Australian Tertiary Hospital: Time Series Analyses of Prevalence Data

    PubMed Central

    Fasugba, Oyebola; Mitchell, Brett G.; Mnatzaganian, George; Das, Anindita; Collignon, Peter; Gardner, Anne

    2016-01-01

    This study describes the antimicrobial resistance temporal trends and seasonal variation of Escherichia coli (E. coli) urinary tract infections (UTIs) over five years, from 2009 to 2013, and compares prevalence of resistance in hospital- and community-acquired E. coli UTI. A cross sectional study of E. coli UTIs from patients attending a tertiary referral hospital in Canberra, Australia was undertaken. Time series analysis was performed to illustrate resistance trends. Only the first positive E. coli UTI per patient per year was included in the analysis. A total of 15,022 positive cultures from 8724 patients were identified. Results are based on 5333 first E. coli UTIs, from 4732 patients, of which 84.2% were community-acquired. Five-year hospital and community resistance rates were highest for ampicillin (41.9%) and trimethoprim (20.7%). Resistance was lowest for meropenem (0.0%), nitrofurantoin (2.7%), piperacillin-tazobactam (2.9%) and ciprofloxacin (6.5%). Resistance to amoxycillin-clavulanate, cefazolin, gentamicin and piperacillin-tazobactam were significantly higher in hospital- compared to community-acquired UTIs (9.3% versus 6.2%; 15.4% versus 9.7%; 5.2% versus 3.7% and 5.2% versus 2.5%, respectively). Trend analysis showed significant increases in resistance over five years for amoxycillin-clavulanate, trimethoprim, ciprofloxacin, nitrofurantoin, trimethoprim-sulphamethoxazole, cefazolin, ceftriaxone and gentamicin (P<0.05, for all) with seasonal pattern observed for trimethoprim resistance (augmented Dickey-Fuller statistic = 4.136; P = 0.006). An association between ciprofloxacin resistance, cefazolin resistance and ceftriaxone resistance with older age was noted. Given the relatively high resistance rates for ampicillin and trimethoprim, these antimicrobials should be reconsidered for empirical treatment of UTIs in this patient population. Our findings have important implications for UTI treatment based on setting of acquisition. PMID:27711250

  17. Role of unloading and filtration of gas in the development of main cracks in coal seams

    NASA Astrophysics Data System (ADS)

    Feldman, E. P.; Kalugina, N. A.; Meln'ik, T. N.

    2017-01-01

    The development of main cracks in coal seams due to rapid unloading is analyzed using the methods of theoretical physics. A fracture criterion and a criterion for the time to fracture of an area at the edge of a coal seam are obtained.

  18. Modelling limit stress of a seam roof ahead of a working face

    NASA Astrophysics Data System (ADS)

    Cherdantsev, N. V.

    2017-09-01

    Solving of boundary problem of geomechanic state of a roof working developed along the seam is introduced in the article. The rock mass works under the condition of a plane-strain deformation with marginal seam zones are in a limit stress state. The problem is solved by boundary element method using Coulomb – Mohr and Mohr – Kuznetsov strength indices.

  19. An overview of lithotype associations of Miocene lignite seams exploited in Poland

    NASA Astrophysics Data System (ADS)

    Widera, Marek

    2016-09-01

    Currently, three stratigraphically distinct lignite seams of Early to Middle Miocene age are exploited in Poland, namely the third Ścinawa lignite seam (ŚLS-3), the second Lusatian lignite seam (LLS-2) and the first Mid-Polish lignite seam (MPLS-1). All of these are composed of numerous macroscopically distinguishable layers defined as lignite lithotypes. In the present paper, the lithotypes of Polish lignites are grouped into seven major lithotype associations that originated in various types of mire. Therefore, an approximate reconstruction of mire type can be based on lignite lithotypes. Within the Polish lignite seams examined, the commonest in order of importance are: xylodetritic (XDL), detroxylitic (DXL), detritic (DL) and xylitic (XL) lithotype associations, mostly with a massive (m) or horizontal (h) structure. They are particularly dominant in lignite opencasts belonging to the Konin and Adamów mines. However, in the lowermost seams at the Turów and Bełchatów mines, a substantial part of the seams comprises the bitumen-rich (BL) lithotype association. These seams also lignite lithotypes that in large quantities have a gelified (g) and/or nodular (n) structure. In contrast, lignites from the Sieniawa mine are characterised by an admixture of the best-developed lithotype associations of both fusitic (FL) and weathered (WL) lignites. Moreover, the vast majority of these lignites have a folded (fo) and/or faulted (fa) structure, because they were completely deformed by glaciotectonics.

  20. A Comparison of the Performance of Seamed and Unseamed Inflatable Concentrators

    DTIC Science & Technology

    1995-01-01

    surface accuracy was minimal. Surface errors were generally slowly varying across the membrane, exhibiting a "W" or " M " shape. When the membrane included...seams, the result was a slight bumpiness in the error profile which retained the "W" or " M " shape at nearly the same level as without seams. Recent

  1. 30 CFR 75.501 - Permissible electric face equipment; coal seams above water table.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Permissible electric face equipment; coal seams..., DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General § 75.501 Permissible electric face equipment; coal seams above water table. On and...

  2. 30 CFR 75.501 - Permissible electric face equipment; coal seams above water table.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Permissible electric face equipment; coal seams..., DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General § 75.501 Permissible electric face equipment; coal seams above water table. On and...

  3. 30 CFR 75.501 - Permissible electric face equipment; coal seams above water table.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Permissible electric face equipment; coal seams..., DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General § 75.501 Permissible electric face equipment; coal seams above water table. On and...

  4. 30 CFR 75.501 - Permissible electric face equipment; coal seams above water table.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Permissible electric face equipment; coal seams..., DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General § 75.501 Permissible electric face equipment; coal seams above water table. On and...

  5. 30 CFR 75.501 - Permissible electric face equipment; coal seams above water table.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Permissible electric face equipment; coal seams... Equipment-General § 75.501 Permissible electric face equipment; coal seams above water table. On and after March 30, 1974, all electric face equipment, other than equipment referred to in paragraph (b) of § 75...

  6. Ganciclovir-Resistant Cytomegalovirus Infection in Abdominal Solid Organ Transplant Recipients: Case Series and Review of the Literature.

    PubMed

    Rolling, Katherine E; Jorgenson, Margaret R; Descourouez, Jillian L; Mandelbrot, Didier A; Redfield, Robert R; Smith, Jeannina A

    2017-07-12

    Ganciclovir-resistant cytomegalovirus (GR-CMV) is emerging as a significant infection in the abdominal transplant population. GR-CMV is difficult to manage, and treatment options are limited. We report a descriptive case series of 15 patients who had documented GR-CMV at our center and review the literature on treatment of GR-CMV. The first case in this series was detected in 2012; the majority of cases occurred after January 1, 2014, with approximately 50% occurring in 2015. UL97 and UL54 viral genome mutations were present in 100% and 40% of CMV-infected patients, respectively. GR-CMV infection occurred ≤ 1 year posttransplantation in 11 patients (73%). All patients experienced dose reduction of valganciclovir (the oral prodrug of ganciclovir) before the development of GR-CMV. Initial treatment for GR-CMV included a variety of regimens, all including reduction in maintenance immunosuppression. Of the 6 patients with detectable GR-CMV by polymerase chain reaction (PCR) who were discharged without GR-CMV treatment and had a length of stay (LOS) less than 14 days, 83% were subsequently readmitted for treatment of GR-CMV within 2 months (60% in < 20 days); none received leflunomide. Of six patients with a LOS ≥ 14 days, 80% had CMV PCR below quantification on hospital discharge, and only one patient was readmitted in less than 20 days; 83% received leflunomide. Following GR-CMV, there was a 50% rejection incidence, 27% graft loss, and 20% mortality. For patients with more than three admissions for GR-CMV treatment, 100% had a major complication: 60% rejection, 20% graft loss, and 40% mortality. Common clinical characteristics of patients with GR-CMV included high-risk serostatus, lymphocyte depletion, and history of valganciclovir dose reduction. Overall, outcomes were poor. It appears that hospital readmission rate was reduced when CMV was treated to negativity with an initial treatment regimen of reduced immunosuppression, foscarnet, intravenous immunoglobulins

  7. Inspection of laser-seam welds in automobile manufacturing

    NASA Astrophysics Data System (ADS)

    Spellenberg, Bernd; Zettner, Jurgen; Schreer, Oliver; Bassler, Michael; Haller, Manfred; Lenzi, Thomas; Hierl, Thomas

    2005-03-01

    Recent developments in infrared camera technology, testing methods and data processing algorithms have brought significant progress for high resolution spatial and temporal analysis of thermal radiation. Together with industry standard automation technology and specific infrared image data processing it became possible to non destructively inspect laser welded seams and other types of joints using heat flux analysis subsequent to active thermal excitation. High thermal diffusion coefficients of the usually metallic samples under test make the availability of high-speed infrared cameras as a key hardware component indispensable. Since high-speed infrared cameras with frame rates of at least 500 Hz have become available for commercial applications, non-destructive testing systems with a new class of performance were designed, manufactured, and implemented at industrial sites. Heat flux analysis as a new and robust method of non-destructive testing has been implemented for various types of equipment, ranging from off-line tools for laboratory use to automated robot based systems enabling fast and operator-free in-line inspection. Depending on environment, implementation surroundings, and geometry of objects to be inspected, different types of pulsed or continuous operating heat sources (e.g. flash light, laser, ...) are selected. Due to its outstanding industrial relevance some examples of non-destructive testing of laser welded seams in automobile manufacturing are shown.

  8. Morphological study on the 'seams' in the multiroot formation of rat molar teeth.

    PubMed

    Kuroiwa, M; Kodaka, T; Higashi, S

    1991-01-01

    'Seams' of the root furcation with multiroots in rat molar teeth, termed by Lester and Boyde, were investigated using transmitted light and scanning electron microscopy in the formation process. The seam was formed in the junctional line of Hertwig's epithelial root sheaths. The seam formation will be classified into three types in the initial stage based on the position of the epithelial root sheaths approaching each other: (1) the close junction or the very narrow slit or gap formed between them, (2) the clear gap containing mesenchymal cells and (3) the gap containing one blood vessel. When the roots were formed, the seam was formed as follows: (1) the slight ridge composed of the cellular cementum, (2) the proliferation or the depression in the dentine formation and (3) the accessory or lateral canal of the root. These structures were variously combined with each other into one seam, although the slight ridge was very common.

  9. 40 CFR Table 28 to Subpart G of... - Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Deck Seam Length Factors a (SD) for..., and Wastewater Pt. 63, Subpt. G, Table 28 Table 28 to Subpart G of Part 63—Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks Deck construction Typical deck seam length factor...

  10. 76 FR 30241 - Pipeline Safety: Notice of Public Meetings on Managing Challenges With Pipeline Seam Welds and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-24

    ... Managing Challenges With Pipeline Seam Welds and Improving Pipeline Risk Assessments and Recordkeeping... meetings. SUMMARY: Recent pipeline incidents involving seam weld anomalies and gaps in data and... provide an open forum for exchanging information on the challenges associated with pipeline seam welds...

  11. Comparing spatial series of soil bulk electrical conductivity as obtained by Time Domain Reflectometry and Electrical Resistivity Tomography

    NASA Astrophysics Data System (ADS)

    Saeed, Ali; Dragonetti, Giovanna; Comegna, Allessandro; Garre, Sarah; Lamaddalena, Nicola; Coppola, Antonio

    2016-04-01

    Conventional ground survey of soil root zone salinity by direct soil sampling are time consuming, costly and destructive. Alternatively, soil salinity can be evaluated by measuring the bulk electrical conductivity, σb, in the field. This approach is faster and cheaper, and allows a more intensive surveying. Measurements of σb can be made either in situ or with remote devices. Time domain reflectometry (TDR) sensors allow simultaneous measurements of water content, θ, and σb. They may be calibrated for estimating the electrical conductivity of the soil solution (σw). However, they have a relatively small observation window and thus they are thought to only provide local-scale measurements. The spatial range of the sensors is limited to tens of centimeters and extension of the information to a large area can be problematic. Also, information on the vertical distribution of the σb soil profile may only be obtained by installing sensors at different depths. In this sense, the TDR may be considered as an invasive technique. Compared to the TDR, other geophysical methods based for example on the Electrical Resistivity Tomography (ERT) techniques represent an alternative in respect to those traditional for soil salinity characterization. In order to deduce the actual distribution of the bulk electrical conductivity, σb, in the soil profile, one needs to invert the signal coming from ERT sensors. The latter, in turn, depends on the specific depth distribution of the σb, as well as on the electrical configuration of the sensor used. With these premises, the main aim of this study is to estimate the vertical σb distribution starting from resistivity data series measured using the ERT method under different salinity conditions and using TDR data as ground-truth data for calibration and validation of the ERT sensor. This way, limited measured TDR data may be used for translating extensive ERT apparent electrical conductivity, σa, measurements to estimate depth

  12. Predictions of fire behavior and resistance to control: for use with photo series for the Douglas fir-hemlock type and the coastal Douglas-fir-hardwood type.

    Treesearch

    David V. SANDBERG; Franklin R. Ward

    1981-01-01

    This publication presents tables on the behavior of fire and the resistance of fuels to control. The information is to be used with the photos in the publication, "Photo Series for Quantifying Forest Residues in the Coastal Douglas-fir—Hemlock Type, Coastal Douglas-fir—Hardwood Type" (Maxwell, Wayne G.; Ward, Franklin R. 1976. Gen. Tech. Rep. PNW-GTR-051....

  13. Glycosylation Genes Expressed in Seam Cells Determine Complex Surface Properties and Bacterial Adhesion to the Cuticle of Caenorhabditis elegans

    PubMed Central

    Gravato-Nobre, Maria J.; Stroud, Dave; O'Rourke, Delia; Darby, Creg; Hodgkin, Jonathan

    2011-01-01

    The surface of the nematode Caenorhabditis elegans is poorly understood but critical for its interactions with the environment and with pathogens. We show here that six genes (bus-2, bus-4, and bus-12, together with the previously cloned srf-3, bus-8, and bus-17) encode proteins predicted to act in surface glycosylation, thereby affecting disease susceptibility, locomotory competence, and sexual recognition. Mutations in all six genes cause resistance to the bacterial pathogen Microbacterium nematophilum, and most of these mutations also affect bacterial adhesion and biofilm formation by Yersinia species, demonstrating that both infection and biofilm formation depend on interaction with complex surface carbohydrates. A new bacterial interaction, involving locomotory inhibition by a strain of Bacillus pumilus, reveals diversity in the surface properties of these mutants. Another biological property—contact recognition of hermaphrodites by males during mating—was also found to be impaired in mutants of all six genes. An important common feature is that all are expressed most strongly in seam cells, rather than in the main hypodermal syncytium, indicating that seam cells play the major role in secreting surface coat and consequently in determining environmental interactions. To test for possible redundancies in gene action, the 15 double mutants for this set of genes were constructed and examined, but no synthetic phenotypes were observed. Comparison of the six genes shows that each has distinctive properties, suggesting that they do not act in a linear pathway. PMID:20980242

  14. Thermal effects of magmatic sills on coal seam metamorphism and gas occurrence

    NASA Astrophysics Data System (ADS)

    Wang, Liang; Cheng, Long-biao; Cheng, Yuan-ping; Yin, Guang-zhi; Cai, Chun-cheng; Xu, Chao; Jin, Kan

    2014-04-01

    Igneous intrusions in coal seams are found in 80 % of coal mines in the Huaibei coalfield, China, and coal and gas outburst accidents have occurred 11 times under a 120-m-thick sill in the Haizi mining field. The magma's heat had a significant controlling effect on coal seam gas occurrence. Based on theoretical analysis, experimental tests and site validation, we analyzed the temperature distribution following magma intrusion into coal measure strata and the variations in multiple physical parameters and adsorption/desorption characteristics between the underlying coal seams beneath the sill in the Haizi mining field and coal seams uninfluenced by magma intrusion in the adjacent Linhuan mining field. The research results show that the main factors controlling the temperature distribution of the magma and surrounding rocks in the cooling process include the cooling time and the thickness and initial temperature of the magmatic rock. As the distance from sill increases, the critical effective temperature and the duration of sustained high temperatures decrease. The sill in the Haizi mining field significantly promoted coal seam secondary hydrocarbon generation in the thermally affected area, which generated approximately 340 m3/t of hydrocarbon. In the magma-affected area, the metamorphic grade, micropore volume, amount of gas adsorption, initial speed of gas desorption, and amount of desorption all increase. Fluid entrapment by sills usually causes the gas pressure and gas content of the underlying coal seams to increase. As a result, the outburst risks from coal seams increases as well.

  15. In-Orbit Construction with a Helical Seam Pipe Mill

    NASA Astrophysics Data System (ADS)

    Gilhooley, N.

    The challenges of building large structures in space, and in particular a torus habitat, require novel processes. One potential method is to manufacture helical seam (also called spiral) pipe in orbit using a pipe mill. These machines turn rolls of steel or alloy into fully formed, welded and inspected pipe, pressure vessels and silos of various diameters. Pipe mills are highly automated and efficient in a factory environment and are increasingly being used for in-situ repair. By constructing in-orbit (on-orbit assembly) the launch vehicle can supply full payloads of compact, robust rolls of material; and the installation design is less restricted by fairing constraints and modular limitations. The use of a pipe mill is discussed as a possible construction method, for comparison an example design envelope is shown and further pipe mill products are considered.

  16. Structural Dependence of Source-and-Drain Series Resistance on Saturation Drain Current for Sub-20 nm Metal-Oxide-Semiconductor Field-Effect Transistors

    NASA Astrophysics Data System (ADS)

    Yoon, JongChul; Hiroki, Akira; Kobayashi, Kazutoshi

    2013-07-01

    The structural dependence of series-resistance effects on the saturation current is investigated in sub-20 nm metal-oxide-semiconductor field-effect transistors (MOSFETs). For planer bulk, silicon-on-insulator (SOI), and multi gate (MG) MOSFETs, the reduction rate of the saturation current is calculated using an analytical current model in high-performance (HP), low-operating-power (LOP), and low-standby-power (LSTP) technologies. In HP technology, the reduction rates are 29.0, 25.3, and 22.1% for bulk, SOI, and MG MOSFETs, respectively. In LOP technology, the reduction rates are 23.8, 21.5, and 20.7% for bulk, SOI, and MG MOSFETs, respectively. In LSTP technology, the reduction rates are about 17% for all devices. In HP technology, the ratio of the series resistance to the channel resistance is the dominant factor for the reduction rate. In LOP technology, the ratio of the over drive voltage to the supply voltage is the dominant factor. In LSTP technology, both the resistance and voltage ratios are the dominant factors.

  17. Structural evaluation of WIPP disposal room raised to Clay Seam G.

    SciTech Connect

    Park, Byoung Yoon; Holland, John F.

    2004-01-01

    This report summarizes a series of structural calculations that examine effects of raising the Waste Isolation Pilot Plant repository horizon from the original design level upward 2.43 meters. These calculations allow evaluation of various features incorporated in conceptual models used for performance assessment. Material presented in this report supports the regulatory compliance re-certification, and therefore begins by replicating the calculations used in the initial compliance certification application. Calculations are then repeated for grid changes appropriate for the new horizon raised to Clay Seam G. Results are presented in three main areas: 1. Disposal room porosity, 2. Disturbed rock zone characteristics, and 3. Anhydrite marker bed failure. No change to the porosity surface for the compliance re-certification application is necessary to account for raising the repository horizon, because the new porosity surface is essentially identical. The disturbed rock zone evolution and devolution are charted in terms of a stress invariant criterion over the regulatory period. This model shows that the damage zone does not extend upward to MB 138, but does reach MB 139 below the repository. Damaged salt would be expected to heal in nominally 100 years. The anhydrite marker beds sustain states of stress that promote failure and substantial marker bed deformation into the room assures fractured anhydrite will sustain in the proximity of the disposal rooms.

  18. Study on Mg/Al Weld Seam Based on Zn–Mg–Al Ternary Alloy

    PubMed Central

    Liu, Liming; Liu, Fei; Zhu, Meili

    2014-01-01

    Based on the idea of alloying welding seams, a series of Zn–xAl filler metals was calculated and designed for joining Mg/Al dissimilar metals by gas tungsten arc (GTA) welding. An infrared thermography system was used to measure the temperature of the welding pool during the welding process to investigate the solidification process. It was found that the mechanical properties of the welded joints were improved with the increasing of the Al content in the Zn–xAl filler metals, and when Zn–30Al was used as the filler metal, the ultimate tensile strength could reach a maximum of 120 MPa. The reason for the average tensile strength of the joint increasing was that the weak zone of the joint using Zn–30Al filler metal was generated primarily by α-Al instead of MgZn2. When Zn–40Al was used as the filler metal, a new transition zone, about 20 μm-wide, appeared in the edge of the fusion zone near the Mg base metal. Due to the transition zones consisting of MgZn2- and Al-based solid solution, the mechanical property of the joints was deteriorated. PMID:28788508

  19. Effects of series and parallel resistances on the C-V characteristics of silicon-based metal oxide semiconductor (MOS) devices

    NASA Astrophysics Data System (ADS)

    Omar, Rejaiba; Mohamed, Ben Amar; Adel, Matoussi

    2015-04-01

    This paper investigates the electrical behavior of the Al/SiO2/Si MOS structure. We have used the complex admittance method to develop an analytical model of total capacitance applied to our proposed equivalent circuit. The charge density, surface potential, semiconductor capacitance, flatband and threshold voltages have been determined by resolving the Poisson transport equations. This modeling is used to predict in particular the effects of frequency, parallel and series resistance on the capacitance-voltage characteristic. Results show that the variation of both frequency and parallel resistance causes strong dispersion of the C-V curves in the inversion regime. It also reveals that the series resistance influences the shape of C-V curves essentially in accumulation and inversion modes. A significant decrease of the accumulation capacitance is observed when R s increases in the range 200-50000 Ω. The degradation of the C-V magnitude is found to be more pronounced when the series resistance depends on the substrate doping density. When R s varies in the range 100 Ω-50 kΩ, it shows a decrease in the flatband voltage from -1.40 to -1.26 V and an increase in the threshold voltage negatively from -0.28 to -0.74 V, respectively. Good agreement has been observed between simulated and measured C-V curves obtained at high frequency. This study is necessary to control the adverse effects that disrupt the operation of the MOS structure in different regimes and optimizes the efficiency of such electronic device before manufacturing.

  20. Analysis and application of coal-seam seismic waves for detecting abandoned mines

    SciTech Connect

    Yancey, D.J.; Irnhof, M.G.; Feddock, J.E.; Gresham, T.

    2007-09-15

    Two in-seam reflection surveys and one transmission survey were acquired at an abandoned underground mine near Hurley, Virginia, to demonstrate the feasibility of detecting abandoned-mine voids utilizing coal-seam seismic waves. Standard, commonly available tools for seismic reflection processing were used. The mine was detected and located by using trapped coal-seam seismic waves observed in both the transmission and reflection data. Detecting the void, however, was not good enough to replace drilling entirely. We conclude that in-seam seismic methods can be used for detection; but if a potential void is detected, focused drilling should be applied for accurate mapping and to circumvent potentially hazardous areas.

  1. Interanal seam loss in Asian turtles of the Cuora flavomarginata complex (Testudines, Geoemydidae)

    USGS Publications Warehouse

    Ernst, Carl H.; Lovich, Jeffrey E.

    2015-01-01

    The taxonomy of Asian box turtles of the genus Cuora is complicated by the description of numerous valid and invalid taxa over the last several decades. However, some characteristics used to differentiate species are questionable. Members of the C. flavomarginata complex are defined by some, but not all, taxonomists as having reduced interanal seam lengths relative to other species. We examined the ratio of interanal scute seam length divided by midline anal scute length in C. flavomarginata and C. evelynae. Hatchlings show a seam that divides 100% of the anal scute along the midline. As individuals increase in carapace length, there is a tendency for the percentage to decrease, especially in females, although there is considerable overlap. We suggest that the decrease in interanal seam length is due to abrasion of the plastron on the substrate as turtles grow larger and older. Differences in habitat substrates across the range of the species may contribute to the wide variation we observed.

  2. Experience of successful treatment of patients with metronidazole-resistant Trichomonas vaginalis with zinc sulfate: A case series.

    PubMed

    Byun, Jung Mi; Jeong, Dae Hoon; Kim, Young Nam; Lee, Kyung Bok; Sung, Moon Su; Kim, Ki Tae

    2015-10-01

    There are no universally successful guidelines for the treatment of metronidazole-resistant vaginal trichomoniasis. This is distressing for patients and frustrating for physicians. We therefore decided to evaluate whether zinc sulfate douche is effective in treating vaginal trichomoniasis, because the compound is a natural antimicrobial chemical defense in humans. In our retrospective case review, eight cases of metronidazole-resistant trichomoniasis were treated with 1% zinc sulfate douche with or without tinidazole between 2005 and 2012. Except for one patient who was pregnant, seven patients were successfully treated and were negative for microscopic findings with no clinical symptoms at follow up. Although the exact role of zinc sulfate in metronidazole-resistant trichomoniasis is not clear, our patients experienced a therapeutic effect with zinc sulfate douche treatment. We therefore recommend zinc sulfate douche as an option for the treatment of metronidazole-resistant vaginal trichomoniasis. Copyright © 2015. Published by Elsevier B.V.

  3. Heatshield for Extreme Entry Environment Technology: Results from Acreage and Integrated Seams Arcjet Testing

    NASA Technical Reports Server (NTRS)

    Venkatapathy, Ethiraj

    2016-01-01

    This invited talk will give a brief overview of the integrated heat-shield system design that requires seams and the extreme environment conditions that HEEET should be demonstrated to be capable of thermal performance without fail. We have tested HEEET across many different facilities and at conditions that are extreme. The presentation will highlight the performance of both the acreage as well as integrated seam at these conditions. The Invite talks are 10 min and hence this presentation will be short.

  4. Epidemiology meets econometrics: using time-series analysis to observe the impact of bed occupancy rates on the spread of multidrug-resistant bacteria.

    PubMed

    Kaier, K; Meyer, E; Dettenkofer, M; Frank, U

    2010-10-01

    Two multivariate time-series analyses were carried out to identify the impact of bed occupancy rates, turnover intervals and the average length of hospital stay on the spread of multidrug-resistant bacteria in a teaching hospital. Epidemiological data on the incidences of meticillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase (ESBL)-producing bacteria were collected. Time-series of bed occupancy rates, turnover intervals and the average length of stay were tested for inclusion in the models as independent variables. Incidence was defined as nosocomial cases per 1000 patient-days. This included all patients infected or colonised with MRSA/ESBL more than 48h after admission. Between January 2003 and July 2008, a mean incidence of 0.15 nosocomial MRSA cases was identified. ESBL was not included in the surveillance until January 2005. Between January 2005 and July 2008 the mean incidence of nosocomial ESBL was also 0.15 cases per 1000 patient-days. The two multivariate models demonstrate a temporal relationship between bed occupancy rates in general wards and the incidence of nosocomial MRSA and ESBL. Similarly, the temporal relationship between the monthly average length of stay in intensive care units (ICUs) and the incidence of nosocomial MRSA and ESBL was demonstrated. Overcrowding in general wards and long periods of ICU stay were identified as factors influencing the spread of multidrug-resistant bacteria in hospital settings.

  5. Altered Antibiotic Transport in OmpC Mutants Isolated from a Series of Clinical Strains of Multi-Drug Resistant E. coli

    PubMed Central

    Ceccarelli, Matteo; Mach, Tivadar; Beis, Konstantinos; Low, Alison S.; Bamford, Victoria A.; Booth, Ian R.; Bayley, Hagan; Naismith, James H.

    2011-01-01

    Antibiotic-resistant bacteria, particularly Gram negative species, present significant health care challenges. The permeation of antibiotics through the outer membrane is largely effected by the porin superfamily, changes in which contribute to antibiotic resistance. A series of antibiotic resistant E. coli isolates were obtained from a patient during serial treatment with various antibiotics. The sequence of OmpC changed at three positions during treatment giving rise to a total of four OmpC variants (denoted OmpC20, OmpC26, OmpC28 and OmpC33, in which OmpC20 was derived from the first clinical isolate). We demonstrate that expression of the OmpC K12 porin in the clinical isolates lowers the MIC, consistent with modified porin function contributing to drug resistance. By a range of assays we have established that the three mutations that occur between OmpC20 and OmpC33 modify transport of both small molecules and antibiotics across the outer membrane. This results in the modulation of resistance to antibiotics, particularly cefotaxime. Small ion unitary conductance measurements of the isolated porins do not show significant differences between isolates. Thus, resistance does not appear to arise from major changes in pore size. Crystal structures of all four OmpC clinical mutants and molecular dynamics simulations also show that the pore size is essentially unchanged. Molecular dynamics simulations suggest that perturbation of the transverse electrostatic field at the constriction zone reduces cefotaxime passage through the pore, consistent with laboratory and clinical data. This subtle modification of the transverse electric field is a very different source of resistance than occlusion of the pore or wholesale destruction of the transverse field and points to a new mechanism by which porins may modulate antibiotic passage through the outer membrane. PMID:22053181

  6. Assessment of the Influence of Fractures on the Dynamics of Coal Seam Fires by Numerical Experiments

    NASA Astrophysics Data System (ADS)

    Wuttke, Manfred W.; Zeng, Qiang

    2016-04-01

    Uncontrolled burning coal seam fires still constitute major problems for the coal industry by destroying the resource, a serious hazard for the local people by severe environmental pollution, and a tremendous threat to the global environment by the emission of greenhouse gases and aerosols. In particular when the seams are lying shallow the alteration of the immediate surrounding of the coal seam fire feeds back on the dynamics of the fire. Thermal stress induced fracturing produces direct connections of the fire zone with the atmosphere. This influences the supply with oxygen, the venting of the exhaust gases, and the dissipation of heat. The first two processes are expected to enhance the fire propagation whereas the latter effect should slow it down. With our dedicated coal seam fire code ACME ("Amendable Coal-fire Modeling Exercise") we study these coupled effects of fractures in simulations of typical coal seam fire scenarios based on data from Xinjiang, China. Fractures are predefined as 1D/2D objects in a 2D/3D model geometry and are opened depending on the passage of the heat wave produced by the coal seam fire.

  7. A global picture of the S 1/S 0 conical intersection seam of benzene

    NASA Astrophysics Data System (ADS)

    Li, Quansong; Mendive-Tapia, David; Paterson, Martin J.; Migani, Annapaola; Bearpark, Michael J.; Robb, Michael A.; Blancafort, Lluís

    2010-11-01

    A global picture of the S 1/S 0 intersection seam of benzene is presented. Eleven new conical intersection critical points were located at the CASSCF level, the connectivity was mapped and the energies refined with CASPT 2. There are two seam branches related with pairs of degenerate A1g/ B2u and E g states at D6h symmetry, respectively, and the two branches are connected by a seam segment of C s symmetry. The global energy minimum of the seam is the half-boat shaped intersection that leads to a pre-fulvenic intermediate [I.J. Palmer, I.N. Ragazos, F. Bernardi, M. Olivucci, M.A. Robb, J. Am. Chem. Soc. 115 (1993) 673]. Several other intersections that can lead to the same intermediate or vibrationally hot benzene lie in a range of 3.7 eV above the global seam minimum. There is a recurrent connectivity pattern where permutationally isomeric seam segments are connected by intersections of a higher symmetry point group.

  8. Expression of key glycosphingolipid biosynthesis-globo series pathway genes in Escherichia coli F18-resistant and Escherichia coli F18-sensitive piglets.

    PubMed

    Dong, W H; Dai, C H; Sun, L; Wang, J; Sun, S Y; Zhu, G Q; Wu, S L; Bao, W B

    2016-08-01

    A pioneering study showed that the glycosphingolipid biosynthesis-globo series pathway genes (FUT1, FUT2, ST3GAL1, HEXA, HEXB, B3GALNT1 and NAGA) may play an important regulatory role in resistance to Escherichia coli F18 in piglets. Therefore, we analysed differential gene expression in 11 tissues of two populations of piglets sensitive and resistant respectively to E. coli F18 and the correlation of differential gene expression in duodenal and jejunal tissues. We found that the mRNA expression of the seven genes was relatively high in spleen, liver, lung, kidney, stomach and intestinal tract; the levels in thymus and lymph nodes were lower, with the lowest levels in heart and muscle. FUT2 gene expression in the duodenum and jejunum of the resistant population was significantly lower than that in the sensitive group (P < 0.01). ST3GAL1 gene expression was also significantly lower in the duodenum of the resistant population than in the sensitive group (P < 0.05). No significant differences were observed among the remaining genes. The expression level of FUT1 was extremely significantly positively correlated with FUT2 and B3GALNT1 expression (P < 0.01) and also had a significant positive correlation with NAGA expression (P < 0.05). The expression level of FUT2 had extremely significant positive correlations with FUT1, ST3GAL1 and B3GALNT1 (P < 0.01). These results suggest that FUT2 plays an important role in E. coli F18 resistance in piglets. FUT1, ST3GAL1, B3GALNT1 and NAGA may also participate in the mechanism of resistance to E. coli F18.

  9. Trends and correlation of antibacterial usage and bacterial resistance: time series analysis for antibacterial stewardship in a Chinese teaching hospital (2009-2013).

    PubMed

    Zou, Y M; Ma, Y; Liu, J H; Shi, J; Fan, T; Shan, Y Y; Yao, H P; Dong, Y L

    2015-04-01

    The purpose of this investigation was to describe the effect of antibacterial stewardship and evaluate the trends and correlation of antibacterial resistance and usage from 2009 to 2013 in a tertiary-care teaching hospital in northwest China. Antibacterial usage was expressed as defined daily doses per 100 patients per day (DDDs/100 PDs). Hospital-wide population-level data and time series analysis were used to evaluate the trends and determine associations between antibacterial exposure and acquisition of resistance. Yearly consumption of overall antibacterials significantly decreased from 66.54 to 28.08 DDDs/100 PDs (β = -10.504, p < 0.01). The resistant rates of the five most frequently isolated species (including Escherichia coli, Acinetobacter baumannii, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae) significantly decreased or remained stable, and none of them showed a statistically significant upward trend. The medical quality indicators got better or remained stable. Autoregressive integrated moving average (ARIMA) models demonstrated that the monthly resistance rate of P. aeruginosa to imipenem was strongly correlated with antipseudomonal carbapenems usage (β = 34.94, p < 0.001), as did the correlation of P. aeruginosa to meropenem with antipseudomonal third-generation cephalosporins usage (β = 32.76, p < 0.01) and K. pneumoniae to amikacin with aminoglycosides usage (β = 22.01, p < 0.001). The decreased antibacterial use paralleled the improved bacterial resistance without deteriorating medical quality indicators during antimicrobial stewardship. It also suggests that optimum antibiotic use is necessary to alleviate the threat posed by resistant microorganisms at the hospital level.

  10. Impact of antibiotic restriction on resistance levels of Escherichia coli: a controlled interrupted time series study of a hospital-wide antibiotic stewardship programme.

    PubMed

    Boel, Jonas; Andreasen, Viggo; Jarløv, Jens Otto; Østergaard, Christian; Gjørup, Ida; Bøggild, Nina; Arpi, Magnus

    2016-07-01

    We evaluated the effect of an antibiotic stewardship programme (ASP) on the use of antibiotics and resistance levels of Escherichia coli using a method that allowed direct comparison between an intervention hospital and a control hospital. The study was conducted as a retrospective controlled interrupted time series (ITS) at two university teaching hospitals, intervention and control, with 736 and 552 beds, respectively. The study period was between January 2008 and September 2014. We used ITS analysis to determine significant changes in antibiotic use and resistance levels of E. coli. Results were directly compared with data from the control hospital utilizing a subtracted time series (STS). Direct comparison with the control hospital showed that the ASP was associated with a significant change in the level of use of cephalosporins [-151 DDDs/1000 bed-days (95% CI -177, -126)] and fluoroquinolones [-44.5 DDDs/1000 bed-days (95% CI -58.9, -30.1)]. Resistance of E. coli showed a significant change in slope for cefuroxime [-0.13 percentage points/month (95% CI -0.21, -0.057)] and ciprofloxacin [-0.15 percentage points/month (95% CI -0.26, -0.038)]. The ASP significantly reduced the use of cephalosporins and fluoroquinolones, with concomitant decreasing levels of E. coli resistance to cefuroxime and ciprofloxacin. The same development was not observed at the control hospital. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  11. Quality of selected coal seams from Indiana: Implications for carbonization

    USGS Publications Warehouse

    Walker, R.; Mastalerz, Maria; Padgett, P.

    2001-01-01

    The chemical properties of two high-volatile bituminous coals, the Danville Coal Member of the Dugger Formation and the Lower Block Coal Member of the Brazil Formation from southern Indiana, were compared to understand the differences in their coking behavior. It was determined that of the two, the Lower Block has better characteristics for coking. Observed factors that contribute to the differences in the coking behavior of the coals include carbon content, organic sulfur content, and oxygen/carbon (O/C) ratios. The Lower Block coal has greater carbon content than the Danville coal, leading to a lower O/C ratio, which is more favorable for coking. Organic sulfur content is higher in the Lower Block coal, and a strong correlation was found between organic sulfur and plasticity. The majority of the data for both seams plot in the Type III zone on a van Krevelen diagram, and several samples from the Lower Block coal plot into the Type II zone, suggesting a perhydrous character for those samples. This divergence in properties between the Lower Block and Danville coals may account for the superior coking behavior of the Lower Block coal. ?? 2001 Elsevier Science B.V. All rights reserved.

  12. Capacitive sensor for high resolution weld seam tracking

    SciTech Connect

    Schmitt, D.J.; Novak, J.L.; Akins, J.L.

    1995-05-01

    A non-contact capacitive sensing system has been developed for guiding automated welding equipment along typical v-groove geometries. The Multi-Axis Seam Tracking (MAST) sensor has been designed to produce four electric fields for locating and measuring the v-groove geometry. In this system, the MAST sensor is coupled with a set of signal conditioning electronics making it possible to output four varying voltages proportional to the electric field perturbations. This output is used for motion control purposes by the automated welding platform to guide the weld torch directly over the center of the v-groove. This report discusses the development of this capacitive sensing system. A functional description of the system and MAST sensor response characteristics for typical weld v-groove geometries are provided. The effects of the harsh thermal and electrical noise environments of plasma arc welding on sensor performance are discussed. A comparison of MAST sensor fabrication from glass-epoxy and thick-film ceramic substrates is provided. Finally, results of v-groove tracking experiments on a robotic welding platform are described.

  13. Treatment of Hypertrophic and Resistant Port Wine Stains With a 755nm Laser: A Case Series of 20 Patients

    PubMed Central

    Izikson, Leonid; Nelson, J. Stuart; Anderson, R. Rox

    2009-01-01

    Background and Objective Port wine stains (PWS) are heterogeneous vascular malformations that can be treated with vascular-selective pulsed dye lasers (PDL). Hypertrophic PWS, especially inadults, are consistently less responsive to PDL. Furthermore, many PWS that respond well initially to PDL treatment may reach a response plateau, becoming unresponsive to further PDL treatments, a phenomenon termed “treatment resistance.” Based on the theory of selective photothermolysis, vessels in such lesions may also bespecifically targetedwitha 755 nm laserthat has selectivity for deoxyhemoglobin as well as oxyhemoglobin and increased depth of skin penetration. StudyDesign/PatientsandMethods Retrospective case review of 20 patients with either hypertrophic or PDL-resistant PWS treated with a 755 nm laser alone or in combination with other lasers, including PDL. Results Hypertrophic PWS showed significant lightening after treatment with a 755 nm laser in combination with PDL. Most PDL-resistant PWS showed moderate improvement after treatment with either a 755 nm laser alone or in combination with another laser, including PDL. Some lesions showed only mild improvement or did not respond. Serious side effects were infrequent. Most commonly encountered complications included pain, edema, bullae, crusting, and rare scarring. Conclusions Alexandrite 755 nm laser can be useful for the treatment of hypertrophic and treatment-resistant PWS in adult and pediatric patients. Complications are infrequent and predictable. Careful attention tousing a fluence at or near the threshold for clinical response with this deeply penetrating laser is essential to prevent serious sequelae. PMID:19588532

  14. Variation in chromosome constitution of the Xiaoyan series partial amphiploids and its relations to stripe rust and stem rust resistance

    USDA-ARS?s Scientific Manuscript database

    In the tertiary gene pool of wheat, tall wheatgrass Thinopyrum ponticum (2n = 10x = 70) is an excellent source of resistance genes against numerous wheat diseases. The creation of wheat-Th. ponticum partial amphiploids is an intermediate step for transferring the useful genes from Th. ponticum to w...

  15. ELT-5 and ELT-6 are required continuously to regulate epidermal seam cell differentiation and cell fusion in C. elegans.

    PubMed

    Koh, K; Rothman, J H

    2001-08-01

    The C. elegans epidermis is a simple epithelium comprised of three major cell types, the seam, syncytial and P cells. While specification of all major epidermal cells is known to require the ELT-1 GATA transcription factor, little is known about how the individual epidermal cell types are specified. We report that elt-5 and -6, adjacent genes encoding GATA factors, are essential for the development of the lateral epidermal cells, the seam cells. Inhibition of elt-5 and -6 function by RNA-mediated interference results in penetrant late embryonic and early larval lethality. Seam cells in affected animals do not differentiate properly: the alae, seam-specific cuticular structures, are generally absent and expression of several seam-specific markers is blocked. In addition, elt-3, which encodes another GATA factor normally expressed in non-seam epidermis, is often ectopically expressed in the seam cells of affected animals, demonstrating that ELT-5 and -6 repress elt-3 expression in wild-type seam cells. Seam cells in affected animals often undergo inappropriate fusion with the epidermal syncytia. Interference of elt-5 and -6 function during larval development can cause fusion of all seam cells with the surrounding syncytia and pronounced defects in molting. elt-5 and -6 are both expressed in seam cells and many other cells, and are apparently functionally interchangeable. Their expression is controlled by separable tissue-specific regulatory elements and the apportionment of monocistronic versus dicistronic transcription of both genes appears to be subject to cell-type-specific regulation. Collectively, these findings indicate that elt-5 and -6 function continuously throughout C. elegans development to regulate seam cell differentiation and cell fusion.

  16. Analysis of temperature-dependant current-voltage characteristics and extraction of series resistance in Pd/ZnO Schottky barrier diodes

    NASA Astrophysics Data System (ADS)

    Mayimele, M. A.; van Rensburg, J. P. Janse; Auret, F. D.; Diale, M.

    2016-01-01

    We report on the analysis of current voltage (I-V) measurements performed on Pd/ZnO Schottky barrier diodes (SBDs) in the 80-320 K temperature range. Assuming thermionic emission (TE) theory, the forward bias I-V characteristics were analysed to extract Pd/ZnO Schottky diode parameters. Comparing Cheung's method in the extraction of the series resistance with Ohm's law, it was observed that at lower temperatures (T<180 K) the series resistance decreased with increasing temperature, the absolute minimum was reached near 180 K and increases linearly with temperature at high temperatures (T>200 K). The barrier height and the ideality factor decreased and increased, respectively, with decrease in temperature, attributed to the existence of barrier height inhomogeneity. Such inhomogeneity was explained based on TE with the assumption of Gaussian distribution of barrier heights with a mean barrier height of 0.99 eV and a standard deviation of 0.02 eV. A mean barrier height of 0.11 eV and Richardson constant value of 37 A cm-2 K-2 were determined from the modified Richardson plot that considers the Gaussian distribution of barrier heights.

  17. Electromagnetic characteristics of a superconducting magnet for the 28 GHz ECR ion source according to the series resistance of the protection circuit

    NASA Astrophysics Data System (ADS)

    Lee, Hongseok; Mo, Young Kyu; Kang, Jong O.; Bang, Seungmin; Kim, Junil; Lee, Onyou; Kang, Hyoungku; Hong, Jonggi; Choi, Sukjin; Hong, In Seok; Nam, Seokho; Ahn, Min Chul

    2015-10-01

    A linear accelerator, called RAON, is being developed as a part of the Rare Isotope Science Project (RISP) at the Institute for Basic Science (IBS). The linear accelerator utilizes an electron cyclotron resonance (ECR) ion source for providing intense highly-charged ion beams to the linear accelerator. The 28-GHz ECR ion source can extract heavy-ion beams from protons to uranium. The superconducting magnet system for the 28-GHz ECR ion source is composed of hexapole coils and four solenoid coils made with low-Tc superconducting wires of NbTi. An electromagnetic force acts on the superconducting magnets due to the magnetic field and flowing current in the case of not only the normal state but also the quench state. In the case of quench on hexapole coils, an unbalanced flowing current among the hexapole coils is generated and causes an unbalanced electromagnetic force. Coil motions and coil strains in the quench state are larger than those in the normal state due to the unbalanced electromagnetic force among hexapole coils. Therefore, an analysis of the electromagnetic characteristics of the superconducting magnet for the 28-GHz ECR ion source on series resistance of the protection circuit in the case of quench should be conducted. In this paper, an analysis of electromagnetic characteristics of Superconducting hexapole coils for the 28-GHz ECR ion source according to the series resistance of the protection circuit in the case of quench performed by using finite-elements-method (FEM) simulations is reported.

  18. Combination of irinotecan and platinum for platinum-resistant or refractory recurrent ovarian cancers: A preliminary case series.

    PubMed

    Shibutani, Takashi; Takano, Masashi; Miyamoto, Morikazu; Yoshikawa, Tomoyuki; Aoyama, Tadashi; Soyama, Hiroaki; Hirata, Junko; Suzuki, Ayako; Sasa, Hidenori; Furuya, Kenichi

    2017-07-01

    Non-platinum single agents are usually used for patients with platinum-resistant recurrent ovarian cancers (ROC). However, the efficacy of these drugs is limited. The aim of the present study was to evaluate the efficacy and adverse events (AE) of combination therapy with irinotecan and platinum (CPT-Pt) for ROC. A total of 28 platinum-resistant or refractory patients with ROC treated with CPT-Pt at the National Defense Medical College Hospital institution between 2002 and 2012 were identified. All patients received taxane and carboplatin (TC) as a first-line treatment and relapsed within 6 months after completion of TC, or progressed during TC therapy. The median age was 59 years (range, 16-78), and median number of CPT-Pt therapy cycles was 5.5 (range, 2-16). The overall response rate was 14%, with a complete response (CR) in 2 patients and partial response (PR) in 2 patients. Stable disease (SD) for >3 months was observed in 15 patients (54%), resulting in a clinical benefit rate (CBR = CR + PR + SD) of 68%. The median progression-free survival and overall survival were 8 and 15 months, respectively. Fifteen cases (68%) developed grade 3/4 hematological AE and 3 cases (11%) developed non-hematological grade 3/4 AE, which were resolved by conservative management or dose reduction. Platinum re-treatment with irinotecan for platinum refractory or resistant ROC may be a candidate in such clinical settings.

  19. Synthesis and antibacterial evaluation of a novel series of synthetic phenylthiazole compounds against methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Mohammad, Haroon; Reddy, P V Narasimha; Monteleone, Dennis; Mayhoub, Abdelrahman S; Cushman, Mark; Seleem, Mohamed N

    2015-04-13

    Methicillin-resistant Staphylococcus aureus infections are a significant global health challenge in part due to the emergence of strains exhibiting resistance to nearly all classes of antibiotics. This underscores the urgent need for the rapid development of novel antimicrobials to circumvent this burgeoning problem. Previously, whole-cell screening of a library of 2,5-disubstituted thiazole compounds revealed a lead compound exhibiting potent antimicrobial activity against MRSA. The present study, conducting a more rigorous analysis of the structure-activity relationship of this compound, reveals a nonpolar, hydrophobic functional group is favored at thiazole-C2 and an ethylidenehydrazine-1-carboximidamide moiety is necessary at C5 for the compound to possess activity against MRSA. Furthermore, the MTS assay confirmed analogs 5, 22d, and 25 exhibited an improved toxicity profile (not toxic up to 40 μg/mL to mammalian cells) over the lead 1. Analysis with human liver microsomes revealed compound 5 was more metabolically stable compared to the lead compound (greater than eight-fold improvement in the half-life in human liver microsomes). Collectively the results presented demonstrate the novel thiazole derivatives synthesized warrant further exploration for potential use as future antimicrobial agents for the treatment of multidrug-resistant S. aureus infections. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  20. Monitoring groundwater-surface water interaction using time-series and time-frequency analysis of transient three-dimensional electrical resistivity changes

    NASA Astrophysics Data System (ADS)

    Johnson, T. C.; Slater, L. D.; Ntarlagiannis, D.; Day-Lewis, F. D.; Elwaseif, M.

    2012-07-01

    Time-lapse resistivity imaging is increasingly used to monitor hydrologic processes. Compared to conventional hydrologic measurements, surface time-lapse resistivity provides superior spatial coverage in two or three dimensions, potentially high-resolution information in time, and information in the absence of wells. However, interpretation of time-lapse electrical tomograms is complicated by the ever-increasing size and complexity of long-term, three-dimensional (3-D) time series conductivity data sets. Here we use 3-D surface time-lapse electrical imaging to monitor subsurface electrical conductivity variations associated with stage-driven groundwater-surface water interactions along a stretch of the Columbia River adjacent to the Hanford 300 near Richland, Washington, USA. We reduce the resulting 3-D conductivity time series using both time-series and time-frequency analyses to isolate a paleochannel causing enhanced groundwater-surface water interactions. Correlation analysis on the time-lapse imaging results concisely represents enhanced groundwater-surface water interactions within the paleochannel, and provides information concerning groundwater flow velocities. Time-frequency analysis using the Stockwell (S) transform provides additional information by identifying the stage periodicities driving groundwater-surface water interactions due to upstream dam operations, and identifying segments in time-frequency space when these interactions are most active. These results provide new insight into the distribution and timing of river water intrusion into the Hanford 300 Area, which has a governing influence on the behavior of a uranium plume left over from historical nuclear fuel processing operations.

  1. Monitoring groundwater-surface water interaction using time-series and time-frequency analysis of transient three-dimensional electrical resistivity changes

    USGS Publications Warehouse

    Johnson, Timothy C.; Slater, Lee D.; Ntarlagiannis, Dimitris; Day-Lewis, Frederick D.; Elwaseif, Mehrez

    2012-01-01

    Time-lapse resistivity imaging is increasingly used to monitor hydrologic processes. Compared to conventional hydrologic measurements, surface time-lapse resistivity provides superior spatial coverage in two or three dimensions, potentially high-resolution information in time, and information in the absence of wells. However, interpretation of time-lapse electrical tomograms is complicated by the ever-increasing size and complexity of long-term, three-dimensional (3-D) time series conductivity data sets. Here we use 3-D surface time-lapse electrical imaging to monitor subsurface electrical conductivity variations associated with stage-driven groundwater-surface water interactions along a stretch of the Columbia River adjacent to the Hanford 300 near Richland, Washington, USA. We reduce the resulting 3-D conductivity time series using both time-series and time-frequency analyses to isolate a paleochannel causing enhanced groundwater-surface water interactions. Correlation analysis on the time-lapse imaging results concisely represents enhanced groundwater-surface water interactions within the paleochannel, and provides information concerning groundwater flow velocities. Time-frequency analysis using the Stockwell (S) transform provides additional information by identifying the stage periodicities driving groundwater-surface water interactions due to upstream dam operations, and identifying segments in time-frequency space when these interactions are most active. These results provide new insight into the distribution and timing of river water intrusion into the Hanford 300 Area, which has a governing influence on the behavior of a uranium plume left over from historical nuclear fuel processing operations.

  2. Determination and compensation of series resistances during whole-cell patch-clamp recordings using an active bridge circuit and the phase-sensitive technique.

    PubMed

    Riedemann, Therese; Polder, Hans Reiner; Sutor, Bernd

    2016-10-01

    We present a technique which combines two methods in order to measure the series resistance (R S) during whole-cell patch-clamp recordings from excitable and non-excitable cells. R S is determined in the amplifier's current-clamp mode by means of an active bridge circuit. The correct neutralization of the electrode capacitance and the adjustment of the bridge circuit is achieved by the so-called phase-sensitive method: Short sine wave currents with frequencies between 3 and 7 kHz are injected into the cells. Complete capacitance neutralization is indicated by the disappearance of the phase lag between current and voltage, and correct bridge balance is indicated by a minimized voltage response to the sine wave current. The R S value determined in the current-clamp mode then provides the basis for R S compensation in the voltage-clamp recording mode. The accuracy of the procedure has been confirmed on single-compartment cell models where the error amounted to 2-3 %. Similar errors were observed during dual patch clamp recordings from single neocortical layer 5 pyramidal cells where one electrode was connected to the bridge amplifier and the other one to a time-sharing, single-electrode current- and voltage-clamp amplifier with negligible R S. The technique presented here allows R S compensation for up to 80-90 %, even in cells with low input resistances (e.g., astrocytes). In addition, the present study underlines the importance of correct R S compensation by showing that significant series resistances directly affect the determination of membrane conductances as well as the kinetic properties of spontaneous synaptic currents with small amplitudes.

  3. Determination of Parachute Joint Factors using Seam and Joint Testing

    NASA Technical Reports Server (NTRS)

    Mollmann, Catherine

    2015-01-01

    This paper details the methodology for determining the joint factor for all parachute components. This method has been successfully implemented on the Capsule Parachute Assembly System (CPAS) for the NASA Orion crew module for use in determining the margin of safety for each component under peak loads. Also discussed are concepts behind the joint factor and what drives the loss of material strength at joints. The joint factor is defined as a "loss in joint strength...relative to the basic material strength" that occurs when "textiles are connected to each other or to metals." During the CPAS engineering development phase, a conservative joint factor of 0.80 was assumed for each parachute component. In order to refine this factor and eliminate excess conservatism, a seam and joint testing program was implemented as part of the structural validation. This method split each of the parachute structural joints into discrete tensile tests designed to duplicate the loading of each joint. Breaking strength data collected from destructive pull testing was then used to calculate the joint factor in the form of an efficiency. Joint efficiency is the percentage of the base material strength that remains after degradation due to sewing or interaction with other components; it is used interchangeably with joint factor in this paper. Parachute materials vary in type-mainly cord, tape, webbing, and cloth -which require different test fixtures and joint sample construction methods. This paper defines guidelines for designing and testing samples based on materials and test goals. Using the test methodology and analysis approach detailed in this paper, the minimum joint factor for each parachute component can be formulated. The joint factors can then be used to calculate the design factor and margin of safety for that component, a critical part of the design verification process.

  4. Impacts of Coal Seam Gas (Coal Bed Methane) Extraction on Water Resources in Australia

    NASA Astrophysics Data System (ADS)

    Post, David

    2014-05-01

    While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States and potentially in Europe, extraction of methane from coal bed methane deposits (termed 'coal seam gas' in Australia) has been the focus in Australia. The two sources of methane share many of the same characteristics, with hydraulic fracturing generally (but not always) required to extract coal seam gas also. However, as coal seam gas deposits generally occur at shallower depths than shale gas, the potential impacts of extraction and hydraulic fracturing on surface and groundwater resources may be potentially of more concern for coal seam gas than for shale gas. To determine the potential for coal seam gas extraction (and coal mining more generally) to impact on water resources and water-related assets in Australia, the Commonwealth Government has recently established an Independent Expert Scientific Committee (the IESC) to provide advice to Commonwealth and State Government regulators on potential water-related impacts of coal seam gas and large coal mining developments. The IESC has in turn implemented a program of research termed 'bioregional assessments' to investigate these potential impacts. A bioregional assessment can be defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion, with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are now being carried out across large portions of eastern Australia which are underlain by coal reserves. Further details of the program can be found at http://www.environment.gov.au/coal-seam-gas-mining/bioregional-assessments.html. This presentation will provide an overview of the issues related to the impacts of coal seam gas extraction on surface and groundwater resources and water-related assets in Australia. The

  5. Structural evaluation of WIPP disposal room raised to Clay Seam G.

    SciTech Connect

    Park, Byoung Yoon (Sandia National Laboratories, Carlsbad, NM); Holland, John F. (Sandia National Laboratories, Albuquerque, NM)

    2007-09-01

    An error was discovered in the ALGEBBRA script used to calculate the disturbed rock zone around the disposal room and the shear failure zone in the anhydrite layers in the original version. To correct the error, a memorandum of correction was submitted according to the Waste Isolation Pilot Plant (WIPP) Quality Assurance program. The recommended course of action was to correct the error, to repeat the post-process, and to rewrite Section 7.4, 7.5, 8, and Appendix B in the original report. The sections and appendix revised by the post-process using the corrected ALGEBRA scripts are provided in this revision. The original report summarizes a series of structural calculations that examine effects of raising the WIPP repository horizon from the original design level upward 2.43 meters. Calculations were then repeated for grid changes appropriate for the new horizon raised to Clay Seam G. Results are presented in three main areas: (1) Disposal room porosity, (2) Disturbed rock zone characteristics, and (3) Anhydrite marker bed failure. No change to the porosity surface for the compliance re-certification application is necessary to account for raising the repository horizon, because the new porosity surface is essentially identical. The disturbed rock zone evolution and devolution are charted in terms of a stress invariant criterion over the regulatory period. This model shows that the propagation of the DRZ into the surrounding rock salt does not penetrate through MB 139 in the case of both the original horizon and the raised room. Damaged salt would be expected to heal in nominally 150 years. The shear failure does not occur in either the upper or lower anhydrite layers at the moment of excavation, but appears above and below the middle of the pillar one day after the excavation. The damaged anhydrite is not expected to heal as the salt in the DRZ is expected to.

  6. Evaluation of a series of 2-napthamide derivatives as inhibitors of the drug efflux pump AcrB for the reversal of antimicrobial resistance.

    PubMed

    Wang, Yinhu; Mowla, Rumana; Guo, Liwei; Ogunniyi, Abiodun D; Rahman, Taufiq; De Barros Lopes, Miguel A; Ma, Shutao; Venter, Henrietta

    2017-02-15

    Drug efflux pumps confer multidrug resistance to dangerous pathogens which makes these pumps important drug targets. We have synthesised a novel series of compounds based on a 2-naphthamide pharmacore aimed at inhibiting the efflux pumps from Gram-negative bacteria. The archeatypical transporter AcrB from Escherichia coli was used as model efflux pump as AcrB is widely conserved throughout Gram-negative organisms. The compounds were tested for their antibacterial action, ability to potentiate the action of antibiotics and for their ability to inhibit Nile Red efflux by AcrB. None of the compounds were antimicrobial against E. coli wild type cells. Most of the compounds were able to inhibit Nile Red efflux indicating that they are substrates of the AcrB efflux pump. Three compounds were able to synergise with antibiotics and reverse resistance in the resistant phenotype. Compound A3, 4-(isopentyloxy)-2-naphthamide, reduced the MICs of erythromycin and chloramphenicol to the MIC levels of the drug sensitive strain that lacks an efflux pump. A3 had no effect on the MIC of the non-substrate rifampicin indicating that this compound acts specifically through the AcrB efflux pump. A3 also does not act through non-specific mechanisms such as outer membrane or inner membrane permeabilisation and is not cytotoxic against mammalian cell lines. Therefore, we have designed and synthesised a novel chemical compound with great potential to further optimisation as inhibitor of drug efflux pumps.

  7. A Valence Bond Description of the Prefulvene Extended Conical Intersection Seam of Benzene.

    PubMed

    Blancafort, Lluís; Robb, Michael A

    2012-12-11

    The permutational isomers of the prefulvene-like minimum energy conical intersection lie on an extended conical intersection seam, where they are connected by higher symmetry structures. Here, we present a VB analysis of the electronic states involved along this extended seam. The VB method produces a spin-exchange density (ie. a bonding pattern) that provides the basis to assign resonance structures to the states. The results show that in the high symmetry region of the seam, the character of the states is dominated by the positive and negative combination of the Kekulé structures, (A+B) and (A-B). The low energy parts of the seam, comprised of lower symmetry conical intersection structures, are stabilized by mixing with the Dewar resonance structures. This feature is responsible for the stability of the benzvalene-like conical intersections. The validity of the VB model is confirmed by calculating the branching space vectors at this level of theory, which are in good agreement with the CASSCF calculated vectors. The VB analysis has also allowed us to complete our picture of the global seam, since it has provided the clue to locate a conical intersection saddle point that interconverts two minima of the prefulvene conical intersection where the carbon bent out of the plane is inverted and rotated by 60°. This saddle point has a benzvalene-like geometry, in agreement with the VB picture.

  8. Mercury emission from coal seam fire at Wuda, Inner Mongolia, China

    NASA Astrophysics Data System (ADS)

    Liang, Yanci; Liang, Handong; Zhu, Shuquan

    2014-02-01

    The underground coal seam fire in the Wuda, Inner Mongolia of china is one of the most serious coal fires in the world with a history over 50 years and endangers the neighboring downwind urban area. To investigate the potential mercury emission and migration from the coal seam fire, in situ real-time measurement of total gaseous mercury (TGM) concentration using Lumex RA-915 + mercury analyzer were implemented on the fire zone and the urban area. The results show an average TGM concentration of 464 ng m-3 in the fumes released from surface vents and cracks on the fire zone, which leads to an elevated TGM concentration of 257 ng m-3 (211-375 ng m-3) in the near-surface air at the fire zone and 89 ng m-3 (23-211 ng m-3) at the peripheral area. The average TGM concentration in the adjoining downwind urban area of Wuda is 33 ng m-3. This result suggests that the coal seam fire may not only contribute to the global mercury inventory but also be a novel source for mercury pollution in the urban areas. The scenario of urban areas being adjacent to coal seam fires is not limited to Wuda but relatively common in northern China and elsewhere. Whether there are other cities under influence of coal seam fires merits further investigation.

  9. Carbapenem-Resistant Enterobacteriaceae Infections: Results From a Retrospective Series and Implications for the Design of Prospective Clinical Trials.

    PubMed

    Alexander, Elizabeth L; Loutit, Jeffery; Tumbarello, Mario; Wunderink, Richard; Felton, Tim; Daikos, George; Fusaro, Karen; White, Dan; Zhang, Shu; Dudley, Michael N

    2017-01-01

    The increasing incidence of multidrug-resistant Gram negatives, such as carbapenem-resistant Enterobacteriaceae (CRE), has resulted in a critical need for new antimicrobials. Most studies of new antimicrobials have been performed in patients with nondrug-resistant pathogens. We performed a retrospective analysis of patients with CRE infections to inform the design of phase 3 clinical trials. This was a retrospective study at 22 centers in 4 countries. Baseline data, treatment, and outcomes were collected in patients with complicated urinary tract infection (cUTI)/acute pyelonephritis (AP), hospital-acquired bacterial pneumonia (HABP), ventilator-associated bacterial pneumonia (VABP), and bacteremia due to CRE. Two hundred fifty-six cases of CRE infection were identified: 75 cUTI/AP, 21 HABP, 20 VABP, and 140 bacteremia. The patient population had significant comorbidities: 32.8% had chronic renal insufficiency, and 26.2% were immunocompromised. Illness severity at presentation was high: 29.3% presented with septic shock. Treatment regimens varied widely; however, a majority of patients received combination therapy. Outcomes were universally poor (28-day mortality was 28.1%) across all sites of infection, particularly in dialysis patients and those with sepsis. The CRE infections occured in patients with substantial comorbidities and were associated with high mortality and low rates of clinical cure with available antibiotics. Patients with these comorbidities are often excluded from enrollment in clinical trials for registration of new drugs. These results led to changes in the inclusion/exclusion criteria of a phase 3 trial to better represent the patient population with CRE infections and enable enrollment. Observational studies may become increasingly important to guide clinical trial design, inform on the existing standard of care, and provide an external control for subsequent trials.

  10. Carbapenem-Resistant Enterobacteriaceae Infections: Results From a Retrospective Series and Implications for the Design of Prospective Clinical Trials

    PubMed Central

    Loutit, Jeffery; Tumbarello, Mario; Wunderink, Richard; Felton, Tim; Daikos, George; Fusaro, Karen; White, Dan; Zhang, Shu; Dudley, Michael N.

    2017-01-01

    Abstract Background. The increasing incidence of multidrug-resistant Gram negatives, such as carbapenem-resistant Enterobacteriaceae (CRE), has resulted in a critical need for new antimicrobials. Most studies of new antimicrobials have been performed in patients with nondrug-resistant pathogens. We performed a retrospective analysis of patients with CRE infections to inform the design of phase 3 clinical trials. Methods. This was a retrospective study at 22 centers in 4 countries. Baseline data, treatment, and outcomes were collected in patients with complicated urinary tract infection (cUTI)/acute pyelonephritis (AP), hospital-acquired bacterial pneumonia (HABP), ventilator-associated bacterial pneumonia (VABP), and bacteremia due to CRE. Results. Two hundred fifty-six cases of CRE infection were identified: 75 cUTI/AP, 21 HABP, 20 VABP, and 140 bacteremia. The patient population had significant comorbidities: 32.8% had chronic renal insufficiency, and 26.2% were immunocompromised. Illness severity at presentation was high: 29.3% presented with septic shock. Treatment regimens varied widely; however, a majority of patients received combination therapy. Outcomes were universally poor (28-day mortality was 28.1%) across all sites of infection, particularly in dialysis patients and those with sepsis. Conclusions. The CRE infections occured in patients with substantial comorbidities and were associated with high mortality and low rates of clinical cure with available antibiotics. Patients with these comorbidities are often excluded from enrollment in clinical trials for registration of new drugs. These results led to changes in the inclusion/exclusion criteria of a phase 3 trial to better represent the patient population with CRE infections and enable enrollment. Observational studies may become increasingly important to guide clinical trial design, inform on the existing standard of care, and provide an external control for subsequent trials. PMID:28584849

  11. The influence of an asymmetry in the sequence rock/coal/rock on the propagation of Rayleigh seam waves

    SciTech Connect

    Dresen, L.; Kerner, C.; Kubach, B.

    1985-06-01

    Small offsets in hard coal seams can be detected with the aid of seam (channel) waves. Transmission and reflection of seam waves depend, among other parameters, upon the symmetry properties of the sequence rock/coal/rock. Two typical unsymmetrical sequences are found in European coal deposits: coal seams with roof and floor of differing acoustic impedance and coal seams interlayered with rock and soil. Two-dimensional analog models with appropriate impedance contrasts are used to study the effect of the unsymmetrical layers upon the propagation of Rayleigh seam waves. Data analysis is based upon amplitude measurements both parallel and perpendicular to the layers and dispersion curves. The effect of unsymmetrical roof (rock 1) and floor (rock 2) was studied with models containing homogeneous coal seams. The influence of a dirt bed on wave propagation was studied in models where the roof and the floor have the same elastic properties. The maximum thickness of the dirt bed did not exceed 20% of the total seam thickness. The effect of the bed's location within the seam was also investigated. For all recorded normal-mode wave groups either the total seam or the coal layers could be regarded as wave guides. This was shown by the fact that the phases could be associated with the phase velocity dispersion curves calculated for the symmetrical sequence rock/coal/ rock. These curves are relevant under the condition that the thickness of the coal layer assumed under the calculation coincides with the thickness of the effective wave guide of the respective wave groups. Wave groups guided in the total seam are not influenced by either the thickness or the position of the dirt bed. On the other hand, for wave groups guided in the coal layers, the quotient of signal amplitudes in the coal layers is influenced by the position of the dirt bed.

  12. Stimulation of commercial coal seam methane production aimed at improving mining technology

    NASA Astrophysics Data System (ADS)

    Shubina, E. A.; Lukyanov, V. G.

    2016-09-01

    The relevance of the current research is due to the urgent need to revise the existing normative bases and procedures involved in intensive development of coal-methane deposits and commercial production of coal seam methane. The article presents the analysis of data on coal production volume and amount of methane emitted into the atmosphere in Kuzbass. There is a need to develop the exploration techniques that would allow implementing pre-mining gas drainage of coal seams and provide the companies with the guidance on coal seam methane drainage in very gassy coal mines. Commercial production of methane should become an integral part of economy and energy balance of the Russian Federation, which, in its turn, would enhance environmental protection due to reducing methane emissions, the largest source of greenhouse effect.

  13. [Percutaneous ablation of atrioventricular junction by radiofrequency current in resistant atrial arrhythmia. Results of a series of 24 patients].

    PubMed

    Sebag, C; Lavergne, T; Ollitrault, J; Cabanis, C; Le Heuzey, J Y; Slama, M; Motté, G; Guize, L

    1992-06-01

    Catheter ablation of the atrioventricular junction may be proposed for the treatment of certain atrial arrhythmias resistant to antiarrhythmic therapy. One of the methods currently being evaluated uses radio-frequency energy which has certain advantages compared with direct current ablation because of the progressive and limited lesions it produces. This technique was used in 24 patients with atrial arrhythmias resistant to antiarrhythmic therapy. The radio-frequency energy was delivered without general anaesthesia with HAT 100 and 200 (OSYPKA) generators in the unipolar mode (average 17.4 watts) for an average period of 22.3 +/- 8 seconds. The catheter (8F USCI suction catheter in the first 18 patients and a 7F Polaris Mansfield, deflectable catheter with a large distal electrode in the remainder) was positioned at the nodo-hisian junction at a point where the two distal electrodes recorded a large atrial deflection and the smallest possible hisian potential. The conduction defects induced during the acute phase generally remain stable in cases of complete atrioventricular block and tend to regress in cases of incomplete atrioventricular block despite initial control of atrioventricular conduction. During follow-up (21 +/- 16 months), 14 patients (58%) remained in complete atrioventricular block, 4 patients (17%) had controlled atrioventricular conduction with an acceptable ventricular rate with associated previously ineffective antiarrhythmic therapy. Radio-frequency ablation was a failure in 6 patients (25%). There were no haemodynamic, rhythmic or ischaemic complications during the acute phase or during follow-up. These results suggest radio-frequency energy is a seductive alternative to direct current ablation for percutaneous modification of atrioventricular conduction in patients with refractory atrial arrhythmias. However, simple modulation of atrioventricular conduction gives aleatory results due to the tendency to regression during follow-up. On the other

  14. Impacts of Coal Seam Gas (Coal Bed Methane) and Coal Mining on Water Resources in Australia

    NASA Astrophysics Data System (ADS)

    Post, D. A.

    2013-12-01

    Mining of coal bed methane deposits (termed ';coal seam gas' in Australia) is a rapidly growing source of natural gas in Australia. Indeed, expansion of the industry is occurring so quickly that in some cases, legislation is struggling to keep up with this expansion. Perhaps because of this, community concern about the impacts of coal seam gas development is very strong. Responding to these concerns, the Australian Government has recently established an Independent Expert Scientific Committee (IESC) to provide advice to the Commonwealth and state regulators on potential water-related impacts of coal seam gas and large coal mining developments. In order to provide the underlying science to the IESC, a program of ';bioregional assessments' has been implemented. One aim of these bioregional assessments is to improve our understanding of the connectivity between the impacts of coal seam gas extraction and groundwater aquifers, as well as their connection to surface water. A bioregional assessment can be defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion, with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are now being carried out across large portions of eastern Australia which are underlain by coal reserves. This presentation will provide an overview of the issues related to the impacts of coal seam gas and coal mining on water resources in Australia. The methodology of undertaking bioregional assessments will be described, and the application of this methodology to six priority bioregions in eastern Australia will be detailed. Preliminary results of the program of research to date will be assessed in light of the requirements of the IESC to provide independent advice to the Commonwealth and State governments. Finally, parallels between the expansion of the industry in Australia with that

  15. 49 CFR 178.61 - Specification 4BW welded steel cylinders with electric-arc welded longitudinal seam.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 4BW welded steel cylinders with... steel cylinders with electric-arc welded longitudinal seam. (a) Type, size and service pressure. A DOT 4BW cylinder is a welded type steel cylinder with a longitudinal electric-arc welded seam, a...

  16. 49 CFR 178.61 - Specification 4BW welded steel cylinders with electric-arc welded longitudinal seam.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 4BW welded steel cylinders with... steel cylinders with electric-arc welded longitudinal seam. (a) Type, size and service pressure. A DOT 4BW cylinder is a welded type steel cylinder with a longitudinal electric-arc welded seam, a...

  17. 49 CFR 178.61 - Specification 4BW welded steel cylinders with electric-arc welded longitudinal seam.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 4BW welded steel cylinders with... steel cylinders with electric-arc welded longitudinal seam. (a) Type, size and service pressure. A DOT 4BW cylinder is a welded type steel cylinder with a longitudinal electric-arc welded seam, a...

  18. 49 CFR 178.61 - Specification 4BW welded steel cylinders with electric-arc welded longitudinal seam.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification 4BW welded steel cylinders with... steel cylinders with electric-arc welded longitudinal seam. (a) Type, size and service pressure. A DOT 4BW cylinder is a welded type steel cylinder with a longitudinal electric-arc welded seam, a...

  19. Wnt signaling controls the stem cell-like asymmetric division of the epithelial seam cells during C. elegans larval development.

    PubMed

    Gleason, Julie E; Eisenmann, David M

    2010-12-01

    Metazoan stem cells repopulate tissues during adult life by dividing asymmetrically to generate another stem cell and a cell that terminally differentiates. Wnt signaling regulates the division pattern of stem cells in flies and vertebrates. While the short-lived nematode C. elegans has no adult somatic stem cells, the lateral epithelial seam cells divide in a stem cell-like manner in each larval stage, usually generating a posterior daughter that retains the seam cell fate and an anterior daughter that terminally differentiates. We show that while wild-type adult animals have 16 seam cells per side, animals with reduced function of the TCF homolog POP-1 have as many as 67 seam cells, and animals with reduced function of the β-catenins SYS-1 and WRM-1 have as few as three. Analysis of seam cell division patterns showed alterations in their stem cell-like divisions in the L2-L4 stages: reduced Wnt signaling caused both daughters to adopt non-seam fates, while activated Wnt signaling caused both daughters to adopt the seam fate. Therefore, our results indicate that Wnt signaling globally regulates the asymmetric, stem cell-like division of most or all somatic seam cells during C. elegans larval development, and that Wnt pathway regulation of stem cell-like behavior is conserved in nematodes.

  20. 40 CFR Table 28 to Subpart G of... - Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks 28 Table 28 to Subpart G of Part 63 Protection of Environment ENVIRONMENTAL..., and Wastewater Pt. 63, Subpt. G, Table 28 Table 28 to Subpart G of Part 63—Deck Seam Length Factors a...

  1. 40 CFR Table 28 to Subpart G of... - Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks 28 Table 28 to Subpart G of Part 63 Protection of Environment ENVIRONMENTAL..., and Wastewater Pt. 63, Subpt. G, Table 28 Table 28 to Subpart G of Part 63—Deck Seam Length Factors a...

  2. 40 CFR Table 28 to Subpart G of... - Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks 28 Table 28 to Subpart G of Part 63 Protection of Environment ENVIRONMENTAL..., and Wastewater Pt. 63, Subpt. G, Table 28 Table 28 to Subpart G of Part 63—Deck Seam Length Factors a...

  3. 40 CFR Table 28 to Subpart G of... - Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks 28 Table 28 to Subpart G of Part 63 Protection of Environment ENVIRONMENTAL..., and Wastewater Pt. 63, Subpt. G, Table 28 Table 28 to Subpart G of Part 63—Deck Seam Length Factors a...

  4. Colistin bladder instillation, an alternative way of treating multi-resistant Acinetobacter urinary tract infection: a case series and review of literature.

    PubMed

    Giua, R; Pedone, C; Cortese, L; Antonelli Incalzi, R

    2014-02-01

    The multiresistant Acinetobacter species bacteria are frequently involved in urinary or respiratory tract infections, and one of the most effective drugs, colistine, is associated with significant nephrotoxicity and neurotoxicity. Given that very high concentrations of colistine into biological fluids are safe for the human organism, attempts have been made at delivering the drug topically, by aerosol, or, occasionally, intratechally or intraventricularly for meningitis. These topical treatments could eradicate the Pseudomonas sp. from the lung of patients with cystic fibrosis or bronchiectasis and the Acinetobacter baumannii from lung and meninges. However, only one case of colistin topic treatment in urinary tract infection is described. We report a case series of three patients successfully undergone colistin bladder instillations for multi drug resistant Acinetobacter urinary tract infection, and we review the literature about colistin topic treatment.

  5. Laser-welded Dissimilar Steel-aluminum Seams for Automotive Lightweight Construction

    NASA Astrophysics Data System (ADS)

    Schimek, M.; Springer, A.; Kaierle, S.; Kracht, D.; Wesling, V.

    By reducing vehicle weight, a significant increase in fuel efficiency and consequently a reduction in CO 2 emissions can be achieved. Currently a high interest in the production of hybrid weld seams between steel and aluminum exists. Previous methods as laser brazing are possible only by using fluxes and additional materials. Laser welding can be used to join steel and aluminum without the use of additives. With a low penetration depth increases in tensile strength can be achieved. Recent results from laser welded overlap seams show that there is no compromise in strength by decreasing penetration depth in the aluminum.

  6. Rock Creek Methane from Multiple-Coal-Seams Completion Project. Semiannual report, July 1987-December 1987

    SciTech Connect

    Beavers, C.D.; Dobscha, F.X.; Green, C.D.; Lambert, S.W.; Boyer, C.M.

    1988-03-01

    Phase I of the Rock Creek Methane from Multiple Coal Seams Completion Project is a multiyear joint venture investigating the combination of drilling, completion, stimulation, and production parameters required for the viable economic production of methane from shallow, multiple coal seams. Project activities at the Rock Creek site in 1987 focused on well drilling and completion, with special emphasis on wellbore acess and hydraulic stimulation. Data on drawdown analysis of the Mary Lee coal group, and testing limited-entry applications to multiseam simulation are included.

  7. Controlled 2D Assembly of Nickel-Seamed Hexameric Pyrogallol[4]arene Nanocapsules.

    PubMed

    Zhang, Chen; Patil, Rahul S; Liu, Chong; Barnes, Charles L; Atwood, Jerry L

    2017-03-01

    The two-dimensional framework of nickel-seamed hexameric metal-organic nanocapsules has been synthesized by connecting the tailed hydroxyl groups of C-propan-3-ol pyrogallol[4]arene with adjacent hexameric capsules via nickel-hydroxyl coordination. In addition, functionalization of nanocapsules with multiple pyridine molecules at the capsule surface prevents them from assembling into hierarchical structures and leads to the formation of discrete nickel-seamed pyrogallol[4]arene nanocapsules. This work shows that surface functionalization of nanocapsules is an effective and innovative method of controlling the assembly of these nanometric building blocks.

  8. Development of signal processing algorithms for ultrasonic detection of coal seam interfaces

    NASA Technical Reports Server (NTRS)

    Purcell, D. D.; Ben-Bassat, M.

    1976-01-01

    A pattern recognition system is presented for determining the thickness of coal remaining on the roof and floor of a coal seam. The system was developed to recognize reflected pulse echo signals that are generated by an acoustical transducer and reflected from the coal seam interface. The flexibility of the system, however, should enable it to identify pulse-echo signals generated by radar or other techniques. The main difference being the specific features extracted from the recorded data as a basis for pattern recognition.

  9. Understanding the self-assembly process and behavior of metal-seamed pyrogallol[4]arene nanocapsules

    NASA Astrophysics Data System (ADS)

    Mossine, Andrew V.

    C-alkylpyrogallol[4]arenes (PgCs) are bowl-shaped compounds that are commonly used as supramolecular building blocks in the construction of larger entities such as capsules, nanotubes, and layered networks. Many of these assemblies are constructed using non-covalent means and, as such, are inherently unstable in polar media. Although metal coordination with the hydroxyl-rich PgC upper rim can be exploited to synthesize assemblies with enhanced stability, few reports of this can be found in the literature. Thus, a thorough investigation of these metal-seamed assemblies and their manipulation is of importance. Prior work in the Atwood lab has produced three examples of metal-organic nanocapsules (MONCs) based on PgCs. These include two hexameric MONCs (based on Cu2+ and Ga3+) as well as a single example of a dimeric MONC (based on Zn2+). As it was unknown whether other metal cations could lead to the formation of similar entities, PgC complexation experiments were conducted with other first series transition metal cations, notably Ni2+, Co2+ and Mn2+. All of these led to nanocapsular materials, which were identified and studied using single crystal X-ray diffraction (scXRD). Once the foundational studies were complete, syntheses were also performed under varied conditions, specifically with Ni2+ and Cu2+. This led to the characterization of both dimeric and hexameric MONCs with these two metals, as well as the characterization of many other capsular materials. The information collected from these experiments also led to an intriguing question: which specific conditions lead to the formation of dimeric vs. hexameric MONCs? To answer this question, solid-state analysis using scXRD was coupled to in situ analysis utilizing small angle neutron scattering (SANS). This work showed that the formation of the dimer is typically favored at higher temperatures while the formation of the hexamer is favored at lower temperatures for both of the metals tested. Studies that varied

  10. Monitoring groundwater-surface water interaction using time-series and time-frequency analysis of transient three-dimensional electrical resistivity changes

    SciTech Connect

    Johnson, Timothy C.; Slater, Lee; Ntarlagiannis, Dimitrios; Day-Lewis, Frederick D.; Elwaseif, Mehrez

    2012-08-22

    Time-lapse resistivity imaging is increasingly used to monitor hydrologic processes. Compared to conventional hydrologic measurements, surface time-lapse resistivity provides (1) superior spatial coverage in two or three dimensions, (2) potentially high-resolution information in time, and (3) information in the absence of wells. However, interpretation of time-lapse electrical tomograms is complicated by the ever increasing size and complexity of long-term, three-dimensional time-series conductivity datasets. Here, we use three-dimensional (3D) surface time-lapse electrical imaging to monitor subsurface electrical conductivity variations associated with stage-driven groundwater/surface-water interaction along a stretch of the Columbia River adjacent to the Hanford 300 Area, Hanford WA, USA. We reduce the resulting 3D conductivity time series using both correlation and time-frequency analysis to isolate a paleochannel causing enhanced groundwater/river-water interaction. Correlation analysis on the time-lapse imaging results concisely represents enhanced ground water/surface-water interaction within the paleochannel, and provides information concerning groundwater flow velocities. Time-frequency analysis using the Stockwell (S) Transform provides additional information by 1) identifying the stage periodicities driving ground water/river-water interaction due to upstream dam operations, 2) identifying segments in time-frequency space when these interactions are most active. These results provide new insight into the distribution and timing of river water intrusion into the Hanford 300 area, which has a governing influence on the behavior of a uranium plume left over from historical nuclear fuel processing operations.

  11. Interventions to reduce colonisation and transmission of antimicrobial-resistant bacteria in intensive care units: an interrupted time series study and cluster randomised trial.

    PubMed

    Derde, Lennie P G; Cooper, Ben S; Goossens, Herman; Malhotra-Kumar, Surbhi; Willems, Rob J L; Gniadkowski, Marek; Hryniewicz, Waleria; Empel, Joanna; Dautzenberg, Mirjam J D; Annane, Djillali; Aragão, Irene; Chalfine, Annie; Dumpis, Uga; Esteves, Francisco; Giamarellou, Helen; Muzlovic, Igor; Nardi, Giuseppe; Petrikkos, George L; Tomic, Viktorija; Martí, Antonio Torres; Stammet, Pascal; Brun-Buisson, Christian; Bonten, Marc J M

    2014-01-01

    Intensive care units (ICUs) are high-risk areas for transmission of antimicrobial-resistant bacteria, but no controlled study has tested the effect of rapid screening and isolation of carriers on transmission in settings with best-standard precautions. We assessed interventions to reduce colonisation and transmission of antimicrobial-resistant bacteria in European ICUs. We did this study in three phases at 13 ICUs. After a 6 month baseline period (phase 1), we did an interrupted time series study of universal chlorhexidine body-washing combined with hand hygiene improvement for 6 months (phase 2), followed by a 12-15 month cluster randomised trial (phase 3). ICUs were randomly assigned by computer generated randomisation schedule to either conventional screening (chromogenic screening for meticillin-resistant Staphylococcus aureus [MRSA] and vancomycin-resistant enterococci [VRE]) or rapid screening (PCR testing for MRSA and VRE and chromogenic screening for highly resistant Enterobacteriaceae [HRE]); with contact precautions for identified carriers. The primary outcome was acquisition of resistant bacteria per 100 patient-days at risk, for which we calculated step changes and changes in trends after the introduction of each intervention. We assessed acquisition by microbiological surveillance and analysed it with a multilevel Poisson segmented regression model. We compared screening groups with a likelihood ratio test that combined step changes and changes to trend. This study is registered with ClinicalTrials.gov, number NCT00976638. Seven ICUs were assigned to rapid screening and six to conventional screening. Mean hand hygiene compliance improved from 52% in phase 1 to 69% in phase 2, and 77% in phase 3. Median proportions of patients receiving chlorhexidine body-washing increased from 0% to 100% at the start of phase 2. For trends in acquisition of antimicrobial-resistant bacteria, weekly incidence rate ratio (IRR) was 0·976 (0·954-0·999) for phase 2 and 1

  12. Interventions to reduce colonisation and transmission of antimicrobial-resistant bacteria in intensive care units: an interrupted time series study and cluster randomised trial

    PubMed Central

    Derde, Lennie P G; Cooper, Ben S; Goossens, Herman; Malhotra-Kumar, Surbhi; Willems, Rob J L; Gniadkowski, Marek; Hryniewicz, Waleria; Empel, Joanna; Dautzenberg, Mirjam J D; Annane, Djillali; Aragão, Irene; Chalfine, Annie; Dumpis, Uga; Esteves, Francisco; Giamarellou, Helen; Muzlovic, Igor; Nardi, Giuseppe; Petrikkos, George L; Tomic, Viktorija; Martí, Antonio Torres; Stammet, Pascal; Brun-Buisson, Christian; Bonten, Marc J M

    2014-01-01

    Summary Background Intensive care units (ICUs) are high-risk areas for transmission of antimicrobial-resistant bacteria, but no controlled study has tested the effect of rapid screening and isolation of carriers on transmission in settings with best-standard precautions. We assessed interventions to reduce colonisation and transmission of antimicrobial-resistant bacteria in European ICUs. Methods We did this study in three phases at 13 ICUs. After a 6 month baseline period (phase 1), we did an interrupted time series study of universal chlorhexidine body-washing combined with hand hygiene improvement for 6 months (phase 2), followed by a 12–15 month cluster randomised trial (phase 3). ICUs were randomly assigned by computer generated randomisation schedule to either conventional screening (chromogenic screening for meticillin-resistant Staphylococcus aureus [MRSA] and vancomycin-resistant enterococci [VRE]) or rapid screening (PCR testing for MRSA and VRE and chromogenic screening for highly resistant Enterobacteriaceae [HRE]); with contact precautions for identified carriers. The primary outcome was acquisition of resistant bacteria per 100 patient-days at risk, for which we calculated step changes and changes in trends after the introduction of each intervention. We assessed acquisition by microbiological surveillance and analysed it with a multilevel Poisson segmented regression model. We compared screening groups with a likelihood ratio test that combined step changes and changes to trend. This study is registered with ClinicalTrials.gov, number NCT00976638. Findings Seven ICUs were assigned to rapid screening and six to conventional screening. Mean hand hygiene compliance improved from 52% in phase 1 to 69% in phase 2, and 77% in phase 3. Median proportions of patients receiving chlorhexidine body-washing increased from 0% to 100% at the start of phase 2. For trends in acquisition of antimicrobial-resistant bacteria, weekly incidence rate ratio (IRR) was 0

  13. The influence of seam height on lost-time injury and fatality rates at small underground bituminous coal mines.

    PubMed

    Peters, R H; Fotta, B; Mallett, L G

    2001-11-01

    Due to variations in the thickness of U.S. coal seams, there is great variability in the height of the roof where underground miners work. Restrictions imposed by low seam heights have important safety consequences. As the height of their workplace decreases, miners must stoop, duck walk, or crawl, and their vision, posture, and mobility become increasingly restricted. Low seam height also places important restrictions on the design of mobile equipment and other mining machinery. Using the employment and injury data reported to the Mine Safety and Health Administration (MSHA) from 1990 to 1996, small underground bituminous coal mines with less than 50 employees were stratified by average coal seam height according to the following categories: low (< or =42"), medium (43"-60"), and high (> or =61"). Injury rates for both nonfatal days lost and fatality cases were examined by seam height and leading type of injury incidents. The leading types of incidents associated with fatalities were roof falls and powered haulage equipment. In comparison to high-seam mines, miners working in low or medium seams are at higher risk of being killed by powered haulage equipment, roof bolting machines, and falls of unsupported roof. The leading types of incidents associated with nonfatal injuries were handling materials and powered haulage. As mining height decreases, miners are at increasingly higher risk of having a nonfatal injury from incidents involving roof bolting machines, load-haul-dump equipment, personnel carriers, and powered haulage conveyors. As mining height increases, miners are at increasingly higher risk of having a nonfatal injury from slips and falls and incidents involving shuttle cars and roof and rib falls. Knee injuries are a particularly severe problem in low-seam mines. The rate of injuries to miners while crawling or kneeling is 10 times higher in low seams than in high seams.

  14. Derivation of Permeability-Pore Relationship for Fractal Porous Reservoirs Using Series-Parallel Flow Resistance Model and Lattice Boltzmann Method

    NASA Astrophysics Data System (ADS)

    Wang, Baoyu; Jin, Yi; Chen, Qing; Zheng, Junling; Zhu, Yibo; Zhang, Xiaobing

    2014-09-01

    Permeability of porous reservoirs plays a significant role in engineering and scientific applications. In this study, we investigated the relationship between pore size fractal dimension (Df) and its porosity, as well as that between Df and the pore structure parameters, and consequentially developed an algorithm to generate pore spaces with arbitrary fractal dimension characterizing the pore size distribution. Using the series-parallel flow resistance model and lattice Boltzmann method (LBM) in combination, we then systematically analyzed the effects of physical properties on the fluid flows in two-dimensional (2D) context, and quantitatively derived a permeability-pore relationship for fractal porous media. The new relationship shows that: (i) the permeability of a fractal porous medium is proportional to the square of its maximum pore size λmax; (ii) the larger the fractal dimension Df of a pore space, the smaller the flow resistance of the porous medium; (iii) porosity φ to the power of (4 - Df)/(2 - Df) is proportional to the permeability of a porous medium; (iv) similar to the Kozeny-Carman (KC) equation, the tortuosity τ has its square inversely proportional to the permeability; more importantly, it is found to be a function of porosity approximately satisfying the relationship τ = φDf-2 in a fractal porous medium. Moreover, we demonstrated that the newly derived fractal permeability-pore relationship is equivalent to KC equation and Poiseuille's law respectively, at Df = 1 and Df = 2.

  15. Deep brain stimulation for severe treatment-resistant obsessive-compulsive disorder: An open-label case series.

    PubMed

    Farrand, Sarah; Evans, Andrew H; Mangelsdorf, Simone; Loi, Samantha M; Mocellin, Ramon; Borham, Adam; Bevilacqua, JoAnne; Blair-West, Scott; Walterfang, Mark A; Bittar, Richard G; Velakoulis, Dennis

    2017-09-01

    brain stimulation was an effective treatment for obsessive-compulsive disorder in these highly selected patients. The extent of the response to deep brain stimulation varied between patients, as well as during the course of treatment for each patient. The results of this series are comparable with the literature, as well as having similar efficacy to ablative psychosurgery techniques such as capsulotomy and cingulotomy. Deep brain stimulation provides advantages over lesional psychosurgery but is more expensive and requires significant multidisciplinary input at all stages, pre- and post-operatively, ideally within a specialised tertiary clinical and/or academic centre. Ongoing research is required to better understand the neurobiological basis for obsessive-compulsive disorder and how this can be manipulated with deep brain stimulation to further improve the efficacy of this emerging treatment.

  16. Bursting at the seams: managing the companion animal population.

    PubMed

    Honey, Laura

    2015-08-01

    Overproduction of companion animals in the UK was one of the topics considered at this year's Animal Welfare Foundation discussion forum. Other subjects discussed included antimicrobial resistance and the ethical dilemmas surrounding advanced treatment options for pets. Laura Honey reports.

  17. Seams of conical intersections relevant to the quenching of OH(A(2)Σ(+)) by collisions with H2.

    PubMed

    Dillon, Joseph; Yarkony, David R

    2013-08-15

    Using multireference configuration interaction wave functions composed of 17–52 million configuration state functions, 18 points on the 1(2)A–2(2)A seam and 162 points on the 2(2)A–3(2)A seam of conical intersections relevant to the collisional quenching of OH(A(2)Σ(+)) by H(2) are determined and analyzed. In the vicinity of planar nuclear configurations, the former seam corresponds to a 1(2)A′–1(2)A″ seam of intersection and the latter corresponds to a 1(2)A′–2(2)A′ seam. For the previously studied 2(2)A–3(2)A seam, two regions not previously examined are reported: (i) an out-of-plane region that connects smoothly to the 1(2)A′–2(2)A′ seam for planar structures and (ii) a Rydberg region that includes D(3h)/C(3v) structures where the 2(2)A–3(2)A seam is a 2(2)A′–3(2)A′ seam for D(3h) structures. Some of the nonplanar points on the 2(2)A–3(2)A seam of conical intersection are found to have OH and H(2) distances comparable to those of the reactant molecules and energies below that of the reactant asymptote. These nonplanar entrance channel conical intersections suggest new mechanisms for the quenching reaction. The Rydberg region introduces new connectivity and symmetry issues. For the 1(2)A–2(2)A [1(2)A′–1(2)A″] seam, which unlike the 2(2)A–3(2)A [1(2)A′–2(2)A′] seam cannot continuously deform from planar to nonplanar structures except through confluences, no evidence of nonplanar points on the conical intersection seam was found. The continuous conical parameters, g(I,J), h(I,J), s(x)(I,J), and s(y)(I,J) and the associated vectors g(I,J), h(I,J), and s(I,J), are determined and discussed. The conical parameters are made continuous by a prescribed rotation of the degenerate wave functions. The continuity of these conical parameters makes it possible to construct a quasi-diabatic representation of the coupled adiabatic potential energy surfaces.

  18. Investigation into the gas-dynamic state of a coal seam under degassing and moistening

    SciTech Connect

    Ruban, A.D.; Zaburdyaev, G.S.; Zaburdyaev, V.S.

    2005-04-01

    Statistics are cited for the violation of gas and dust conditions in mines of Russia and the material damage caused by gas and dust explosions. It is shown that degassing and moistening of a seam is the most efficiently conducted by the hydraulic pulse action.

  19. Blast-free mining of coal seams by excavators equipped with rotary dynamic buckets

    SciTech Connect

    Labutin, V.N.; Mattis, A.R.; Zaitseva, A.A.

    2005-04-01

    The necessity to equip cable excavators with rotary buckets is substantiated. The results of graphic-analytical analysis of the rotary bucket operation are presented, and its main advantages are determined in comparison with conventional buckets in mining coal seams of complex structure.

  20. Analysis of local fractures and crack growth in coal seams under compression

    SciTech Connect

    S.V. Kuznetsov; V.A. Trofimov

    2006-01-15

    An analysis is performed for the effect that a growing rock pressure in stress concentration zones has on development of local fractures of coal due to stratal water, and on closing-up of bedding joints, which confines this process. It is shown that all of unstable cracks in a seam grow dynamically until the related bedding crack closing-up.

  1. The mechanics of intersecting echelon veins and pressure solution seams in limestone

    NASA Astrophysics Data System (ADS)

    Seyum, Solomon; Pollard, David D.

    2016-08-01

    Many studies that describe the formation of echelon vein arrays relate the causative stresses implicitly to the deformation, reliant on simple shear kinematics, such that the vein-to-array angle and the array width are the primary physical quantities. In contrast, we identify twelve physical quantities to describe echelon veins in two dimensions, including coeval, vein-intersecting, pressure solution seams. A finite element method is used to reproduce vein shapes in linear elastic and elastic-perfectly plastic model limestone. Model vein geometries are designed using values within the range of geometries measured from echelon veins at Raplee Anticline and Comb Monocline, Utah. Four physical quantities are significant for describing echelon vein shapes: vein spacing, vein-array angle, limestone elastic stiffness, and closing of orthogonal pressure solution seams. Pressure solution seam closing influences the mechanical interaction between adjacent veins, and for a range of conditions, causes a nearly linear vein opening distribution (triangular shapes) and encourages straight vein propagation, both of which approximate field measurements. Model results show that small spacing of veins with seams and large vein-array angles promote straight vein traces in limestone with stiffness typical of laboratory measurements, given the physical geologic conditions inferred from the burial history of the limestone strata.

  2. 18 CFR 270.302 - Occluded natural gas produced from coal seams.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Occluded natural gas... DETERMINATION PROCEDURES Requirements for Filings With Jurisdictional Agencies § 270.302 Occluded natural gas produced from coal seams. A person seeking a determination that natural gas is occluded natural gas...

  3. 18 CFR 270.302 - Occluded natural gas produced from coal seams.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Occluded natural gas... DETERMINATION PROCEDURES Requirements for Filings With Jurisdictional Agencies § 270.302 Occluded natural gas produced from coal seams. A person seeking a determination that natural gas is occluded natural gas...

  4. 18 CFR 270.302 - Occluded natural gas produced from coal seams.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Occluded natural gas... DETERMINATION PROCEDURES Requirements for Filings With Jurisdictional Agencies § 270.302 Occluded natural gas produced from coal seams. A person seeking a determination that natural gas is occluded natural gas...

  5. 18 CFR 270.302 - Occluded natural gas produced from coal seams.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Occluded natural gas... DETERMINATION PROCEDURES Requirements for Filings With Jurisdictional Agencies § 270.302 Occluded natural gas produced from coal seams. A person seeking a determination that natural gas is occluded natural gas...

  6. 18 CFR 270.302 - Occluded natural gas produced from coal seams.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Occluded natural gas... DETERMINATION PROCEDURES Requirements for Filings With Jurisdictional Agencies § 270.302 Occluded natural gas produced from coal seams. A person seeking a determination that natural gas is occluded natural gas...

  7. Image resizing using saliency strength map and seam carving for white blood cell analysis.

    PubMed

    Ko, ByoungChul; Kim, SeongHoon; Nam, JaeYeal

    2010-09-20

    A new image-resizing method using seam carving and a Saliency Strength Map (SSM) is proposed to preserve important contents, such as white blood cells included in blood cell images. To apply seam carving to cell images, a SSM is initially generated using a visual attention model and the structural properties of white blood cells are then used to create an energy map for seam carving. As a result, the energy map maximizes the energies of the white blood cells, while minimizing the energies of the red blood cells and background. Thus, the use of a SSM allows the proposed method to reduce the image size efficiently, while preserving the important white blood cells. Experimental results using the PSNR (Peak Signal-to-Noise Ratio) and ROD (Ratio of Distortion) of blood cell images confirm that the proposed method is able to produce better resizing results than conventional methods, as the seam carving is performed based on an SSM and energy map. For further improvement, a faster medical image resizing method is currently being investigated to reduce the computation time, while maintaining the same image quality.

  8. In situ determination of sulphur in coal seams and overburden rock by PGNAA

    NASA Astrophysics Data System (ADS)

    Borsaru, M.; Berry, M.; Biggs, M.; Rojc, A.

    2004-01-01

    The prompt gamma neutron activation analysis technique was tested successfully for the determination of sulphur in coal seams and overburden rock. The logging tool employs a 3 μg 252Cf neutron source and a 50 mm dia × 100 mm BGO detector.

  9. FREEZE-THAW CYCLING AND COLD TEMPERATURE EFFECTS ON GEOMEMBRANE SHEETS AND SEAMS. Project summary

    EPA Science Inventory

    The effects of freeze-thaw cycling on the tensile strength of 19 geomembranes and 31 different seam types were investigated. The study was performed in three parts using different test conditions. Part I involved incubating unconfined specimens in freeze-thaw cycles and then per...

  10. Physical Simulation Method for the Investigation of Weld Seam Formation During the Extrusion of Aluminum Alloys

    NASA Astrophysics Data System (ADS)

    Fang, Gang; Nguyen, Duc-Thien; Zhou, Jie

    2016-12-01

    Extrusion through the porthole die is a predominant forming process used in the production of hollow aluminum alloy profiles across the aluminum extrusion industry. Longitudinal weld seams formed during the process may negatively influence the quality of extruded profiles. It is therefore of great importance to understand the formation of weld seams inside the welding chamber during extrusion, as affected by extrusion process variables and die design. Previously developed physical simulation methods could not fully reproduce the thermomechanical conditions inside the welding chamber of porthole die. In this research, a novel physical simulation method for the investigation of weld seam formation during extrusion was developed. With a tailor-designed tooling set mounted on a universal testing machine, the effects of temperature, speed, and strain on the weld seam quality of the 6063 alloy were investigated. The strains inside the welding chamber were found to be of paramount importance for the bonding of metal streams, accompanied by microstructural changes, i.e., recovery or recrystallization, depending on the local deformation condition. The method was shown to be able to provide guidelines for the design of porthole dies and choice of extrusion process variables, thereby reducing the scrap rate of aluminum extrusion operation.

  11. Coming apart at the seams: morphological evidence for pregnathal head capsule borders in adult Tribolium castaneum

    USDA-ARS?s Scientific Manuscript database

    Cephalization and seamless fusion of the anterior body segments during development obscure the segmental origins of the insect head. Most of the visible seams are thought to reflect infolding for structural reinforcement rather than a merger of segmental or cuticular plate borders. Incomplete fusion...

  12. A study on anti-light disturbance in laser position detecting to welding seam

    NASA Astrophysics Data System (ADS)

    Liu, Nan-sheng; Guo, Chang-rong; Liu, Ming-you

    2006-02-01

    Laser position detecting to weld seam is based on the principle of structured light measuring. The intense arc, combusting gas and spatters influence the acquisition of weld seam image in the process of welding. Therefore, the problem of anti-light disturbance is studied in four aspects. First, the forming factors of the light disturbance such as the arc and the melting cell radiation and so on is studied from the viewpoint of the distribution of spectrum energy. Matching the narrow-band filter with the wavelength of laser can obstruct the ultraviolet and infrared radiation. Secondly, the influence brought by the reflection on the surface of steel plate is studied and a neutral filter is used to absorb the light disturbance and then the signal-to-noise ratio of an image is improved. Thirdly, there are still some stripes of spatters on image after compound filtering. For calculating the position of weld seam, the technology of digital image processing is also adopted. And finally, obstructing the light disturbance by a mechanical part is also an important measure. A baffle installed between the welding torch and the laser sensor can effectively obstruct some of the spatters. After taking the above four aspects measures, the light disturbance is better eliminated and a clear image is acquired. It can be used to track the weld seam by crawling arc welding robot.

  13. FREEZE-THAW CYCLING AND COLD TEMPERATURE EFFECTS ON GEOMEMBRANE SHEETS AND SEAMS. Project summary

    EPA Science Inventory

    The effects of freeze-thaw cycling on the tensile strength of 19 geomembranes and 31 different seam types were investigated. The study was performed in three parts using different test conditions. Part I involved incubating unconfined specimens in freeze-thaw cycles and then per...

  14. Replacement of seam welded hot reheat pipe using narrow groove GTA machine welding

    SciTech Connect

    Richardson, R.R.; Yanes, J.; Bryant, R.; Fennig, J.D.

    1995-12-31

    Southern California Edison, recognizing a potential safety concern, scrutinized its existing seam welded hot reheat pipe manufactured by the same supplier as that which failed. Alternatives were narrowed to two in dealing with the installed seam welded pipe. The overriding consideration, however, was one of safety. With this in mind, the utility company evaluated replacement of the seam welded hot reheat pipe with seamless pipe or increasing the frequency of its inspection program. Although increased inspection was much costly, pipe replacement was chosen due to potential safety concerns with seam welded pipe even with more frequent inspection. The utility company then proceeded to determine the most effective method to complete this work. Analysis showed machine-made (automatic) gas tungsten arc welds (GTAW) as the method of choice due to cleanliness and superior mechanical properties. In conjunction with this method, the narrow groove (3{degree} bevel) weld joint as opposed to the traditional groove (37 1/2{degree} bevel) was shown to provide significant technical advantages.

  15. Evaluating the conditions of spread of endogenous fires in steep seams

    SciTech Connect

    Vylegzhanin, V.N.

    1987-09-01

    This article correlates the collapse behavior and rock mechanics of an inclined coal seam with its combustibility and the projected spread of a mine fire along the shaft or roadway in an extensive mathematical model which takes into account such variables as coal porosity, deformation, displacement, and gas composition and which can be used to forecast and prevent possible fire hazards.

  16. Physical Simulation Method for the Investigation of Weld Seam Formation During the Extrusion of Aluminum Alloys

    NASA Astrophysics Data System (ADS)

    Fang, Gang; Nguyen, Duc-Thien; Zhou, Jie

    2017-04-01

    Extrusion through the porthole die is a predominant forming process used in the production of hollow aluminum alloy profiles across the aluminum extrusion industry. Longitudinal weld seams formed during the process may negatively influence the quality of extruded profiles. It is therefore of great importance to understand the formation of weld seams inside the welding chamber during extrusion, as affected by extrusion process variables and die design. Previously developed physical simulation methods could not fully reproduce the thermomechanical conditions inside the welding chamber of porthole die. In this research, a novel physical simulation method for the investigation of weld seam formation during extrusion was developed. With a tailor-designed tooling set mounted on a universal testing machine, the effects of temperature, speed, and strain on the weld seam quality of the 6063 alloy were investigated. The strains inside the welding chamber were found to be of paramount importance for the bonding of metal streams, accompanied by microstructural changes, i.e., recovery or recrystallization, depending on the local deformation condition. The method was shown to be able to provide guidelines for the design of porthole dies and choice of extrusion process variables, thereby reducing the scrap rate of aluminum extrusion operation.

  17. Nitrogen Injection To Flush Coal Seam Gas Out Of Coal: An Experimental Study

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Aziz, Naj; Ren, Ting; Nemcik, Jan; Tu, Shihao

    2015-12-01

    Several mines operating in the Bulli seam of the Sydney Basin in NSW, Australia are experiencing difficulties in reducing gas content within the available drainage lead time in various sections of the coal deposit. Increased density of drainage boreholes has proven to be ineffective, particularly in sections of the coal seam rich in CO2. Plus with the increasing worldwide concern on green house gas reduction and clean energy utilisation, significant attention is paid to develop a more practical and economical method of enhancing the gas recovery from coal seams. A technology based on N2 injection was proposed to flush the Coal Seam Gas (CSG) out of coal and enhance the gas drainage process. In this study, laboratory tests on CO2 and CH4 gas recovery from coal by N2 injection are described and results show that N2 flushing has a significant impact on the CO2 and CH4 desorption and removal from coal. During the flushing stage, it was found that N2 flushing plays a more effective role in reducing adsorbed CH4 than CO2. Comparatively, during the desorption stage, the study shows gas desorption after N2 flushing plays a more effective role in reducing adsorbed CO2 than CH4.

  18. Lining seam elimination algorithm and surface crack detection in concrete tunnel lining

    NASA Astrophysics Data System (ADS)

    Qu, Zhong; Bai, Ling; An, Shi-Quan; Ju, Fang-Rong; Liu, Ling

    2016-11-01

    Due to the particularity of the surface of concrete tunnel lining and the diversity of detection environments such as uneven illumination, smudges, localized rock falls, water leakage, and the inherent seams of the lining structure, existing crack detection algorithms cannot detect real cracks accurately. This paper proposed an algorithm that combines lining seam elimination with the improved percolation detection algorithm based on grid cell analysis for surface crack detection in concrete tunnel lining. First, check the characteristics of pixels within the overlapping grid to remove the background noise and generate the percolation seed map (PSM). Second, cracks are detected based on the PSM by the accelerated percolation algorithm so that the fracture unit areas can be scanned and connected. Finally, the real surface cracks in concrete tunnel lining can be obtained by removing the lining seam and performing percolation denoising. Experimental results show that the proposed algorithm can accurately, quickly, and effectively detect the real surface cracks. Furthermore, it can fill the gap in the existing concrete tunnel lining surface crack detection by removing the lining seam.

  19. A poromechanical model for coal seams saturated with binary mixtures of CH4 and CO2

    NASA Astrophysics Data System (ADS)

    Nikoosokhan, Saeid; Vandamme, Matthieu; Dangla, Patrick

    2014-11-01

    Underground coal bed reservoirs naturally contain methane which can be produced. In parallel of the production of this methane, carbon dioxide can be injected, either to enhance the production of methane, or to have this carbon dioxide stored over geological periods of time. As a prerequisite to any simulation of an Enhanced Coal Bed Methane recovery process (ECBM), we need state equations to model the behavior of the seam when cleats are saturated with a miscible mixture of CH4 and CO2. This paper presents a poromechanical model of coal seams exposed to such binary mixtures filling both the cleats in the seam and the porosity of the coal matrix. This model is an extension of a previous work which dealt with pure fluid. Special care is dedicated to keep the model consistent thermodynamically. The model is fully calibrated with a mix of experimental data and numerical data from molecular simulations. Predicting variations of porosity or permeability requires only calibration based on swelling data. With the calibrated state equations, we predict numerically how porosity, permeability, and adsorbed amounts of fluid vary in a representative volume element of coal seam in isochoric or oedometric conditions, as a function of the pressure and of the composition of the fluid in the cleats.

  20. 30 CFR 75.501-1 - Coal seams above the water table.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Coal seams above the water table. 75.501-1 Section 75.501-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General §...

  1. 30 CFR 75.501-1 - Coal seams above the water table.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Coal seams above the water table. 75.501-1 Section 75.501-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General §...

  2. 30 CFR 75.501-1 - Coal seams above the water table.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Coal seams above the water table. 75.501-1 Section 75.501-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General §...

  3. 30 CFR 75.501-1 - Coal seams above the water table.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Coal seams above the water table. 75.501-1 Section 75.501-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General §...

  4. 30 CFR 75.501-1 - Coal seams above the water table.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Coal seams above the water table. 75.501-1 Section 75.501-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General §...

  5. Mechanism of Rock Burst Occurrence in Specially Thick Coal Seam with Rock Parting

    NASA Astrophysics Data System (ADS)

    Wang, Jian-chao; Jiang, Fu-xing; Meng, Xiang-jun; Wang, Xu-you; Zhu, Si-tao; Feng, Yu

    2016-05-01

    Specially thick coal seam with complex construction, such as rock parting and alternative soft and hard coal, is called specially thick coal seam with rock parting (STCSRP), which easily leads to rock burst during mining. Based on the stress distribution of rock parting zone, this study investigated the mechanism, engineering discriminant conditions, prevention methods, and risk evaluation method of rock burst occurrence in STCSRP through setting up a mechanical model. The main conclusions of this study are as follows. (1) When the mining face moves closer to the rock parting zone, the original non-uniform stress of the rock parting zone and the advancing stress of the mining face are combined to intensify gradually the shearing action of coal near the mining face. When the shearing action reaches a certain degree, rock burst easily occurs near the mining face. (2) Rock burst occurrence in STCSRP is positively associated with mining depth, advancing stress concentration factor of the mining face, thickness of rock parting, bursting liability of coal, thickness ratio of rock parting to coal seam, and difference of elastic modulus between rock parting and coal, whereas negatively associated with shear strength. (3) Technologies of large-diameter drilling, coal seam water injection, and deep hole blasting can reduce advancing stress concentration factor, thickness of rock parting, and difference of elastic modulus between rock parting and coal to lower the risk of rock burst in STCSRP. (4) The research result was applied to evaluate and control the risk of rock burst occurrence in STCSRP.

  6. Binding mode characterization of NBD series CD4-mimetic HIV-1 entry inhibitors by X-ray structure and resistance study.

    PubMed

    Curreli, Francesca; Kwon, Young Do; Zhang, Hongtao; Yang, Yongping; Scacalossi, Daniel; Kwong, Peter D; Debnath, Asim K

    2014-09-01

    We previously identified two small-molecule CD4 mimetics--NBD-556 and NBD-557--and synthesized a series of NBD compounds that resulted in improved neutralization activity in a single-cycle HIV-1 infectivity assay. For the current investigation, we selected several of the most active compounds and assessed their antiviral activity on a panel of 53 reference HIV-1 Env pseudoviruses representing diverse clades of clinical isolates. The selected compounds inhibited tested clades with low-micromolar potencies. Mechanism studies indicated that they act as CD4 agonists, a potentially unfavorable therapeutic trait, in that they can bind to the gp120 envelope glycoprotein and initiate a similar physiological response as CD4. However, one of the compounds, NBD-09027, exhibited reduced agonist properties, in both functional and biophysical studies. To understand the binding mode of these inhibitors, we first generated HIV-1-resistant mutants, assessed their behavior with NBD compounds, and determined the X-ray structures of two inhibitors, NBD-09027 and NBD-10007, in complex with the HIV-1 gp120 core at ∼2-Å resolution. Both studies confirmed that the NBD compounds bind similarly to NBD-556 and NBD-557 by inserting their hydrophobic groups into the Phe43 cavity of gp120. The basic nitrogen of the piperidine ring is located in close proximity to D368 of gp120 but it does not form any H-bond or salt bridge, a likely explanation for their nonoptimal antagonist properties. The results reveal the structural and biological character of the NBD series of CD4 mimetics and identify ways to reduce their agonist properties and convert them to antagonists. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  7. On the extent and connectivity of conical intersection seams and the effects of three-state intersections.

    PubMed

    Coe, Joshua D; Ong, Mitchell T; Levine, Benjamin G; Martínez, Todd J

    2008-12-11

    We discuss the connectivity of intersection spaces and the role of minimal energy points within these intersection spaces (minimal energy conical intersections or MECIs) in promoting nonadiabatic transitions. We focus on malonaldeyde as a specific example, where there is a low-lying three-state conical intersection. This three-state intersection is the global minimum on the bright excited electronic state, but it plays a limited role in population transfer in our ab initio multiple spawning (AIMS) simulations because the molecule must traverse a series of two-state conical intersections to reach the three-state intersection. Due to the differences in seam space dimensionality separating conventional (two-state) and three-state intersections, we suggest that dynamical effects arising directly from a three-state intersection may prove difficult to observe in general. We also use a newly developed method for intersection optimization with geometric constraints to demonstrate the connectivity of all the stationary points in the intersection spaces for malonaldehyde. This supports the conjecture that all intersection spaces are connected, and that three-state intersections play a key role in extending this connectivity to all pairs of states, e.g. the S1/S0 and S2/S1 intersection spaces.

  8. On the extent and connectivity of conical intersection seams and the effects of three-state intersections

    SciTech Connect

    Coe, Joshua D; Levine, B G; Ong, M T; Martinez, T J

    2008-01-01

    We discuss the connectivity of intersection spaces and the role of minimal energy points within these intersection spaces (minimal energy conical intersections or MECIs) in promoting nonadiabatic transitions. We focus on malonaldeyde as a specific example, where there is a low-lying three-state conical intersection. This three-state intersection is the global minimum on the bright excited electronic state, but it plays a limited role in population transfer in our ab initio multiple spawning (AIMS) simulations because the molecule must traverse a series of two-state conical intersections to reach the three-state intersection. Due to the differences in seam space dimensionality separating conventional (two-state) and three-state intersections, we suggest that dynamical effects arising directly from a three-state intersection may prove difficult to observe in general. We also use a newly developed method for intersection optimization with geometric constraints to demonstrate the connectivity of all the stationary points in the intersection spaces for malonaldehyde. This supports the conjecture that all intersection spaces are connected, and that three-state intersections play a key role in extending this connectivity to all pairs of states, e.g. the S{sub 1}/S{sub 0} and S{sub 2}/S{sub 1} intersection spaces.

  9. Design, Synthesis, Protein−Ligand X-ray Structure, and Biological Evaluation of a Series of Novel Macrocyclic Human Immunodeficiency Virus-1 Protease Inhibitors to Combat Drug Resistance

    SciTech Connect

    Ghosh, Arun K.; Kulkarni, Sarang; Anderson, David D.; Hong, Lin; Baldridge, Abigail; Wang, Yuan-Fang; Chumanevich, Alexander A.; Kovalevsky, Andrey Y.; Tojo, Yasushi; Amano, Masayuki; Koh, Yasuhiro; Tang, Jordan; Weber, Irene T.; Mitsuya, Hiroaki

    2010-04-05

    The structure-based design, synthesis, and biological evaluation of a series of nonpeptidic macrocyclic HIV protease inhibitors are described. The inhibitors are designed to effectively fill in the hydrophobic pocket in the S1'-S2' subsites and retain all major hydrogen bonding interactions with the protein backbone similar to darunavir (1) or inhibitor 2. The ring size, the effect of methyl substitution, and unsaturation within the macrocyclic ring structure were assessed. In general, cyclic inhibitors were significantly more potent than their acyclic homologues, saturated rings were less active than their unsaturated analogues and a preference for 10- and 13-membered macrocylic rings was revealed. The addition of methyl substituents resulted in a reduction of potency. Both inhibitors 14b and 14c exhibited marked enzyme inhibitory and antiviral activity, and they exerted potent activity against multidrug-resistant HIV-1 variants. Protein-ligand X-ray structures of inhibitors 2 and 14c provided critical molecular insights into the ligand-binding site interactions.

  10. Carrier transportation properties and series resistance of n-type β-FeSi2/p-type Si heterojunctions fabricated by RF magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Nopparuchikun, Adison; Promros, Nathaporn; Teakchaicum, Sakmongkon; Onsee, Peeradon; Duangrawa, Asanlaya; Sittimart, Phongsaphak

    2017-06-01

    Heterojunctions composed of n-type β-FeSi2 thin films and p-type Si(111) substrates were formed by radio frequency magnetron sputtering at an Ar pressure of 2.66 × 10-1 Pa at a substrate temperature of 560 °C. The current density-voltage (J-V) curves of the heterojunctions measured in the dark and under illumination at room temperature showed a large leakage current under reverse bias conditions and a weak response to near-infrared (NIR) light irradiation. From the results of the analysis of dark forward J-V curves, the dominant carrier transport mechanisms at V ≤ 0.15 V and V > 0.15 V were considered a recombination process and a space-charge-limited current process, respectively. Both capacitance-voltage and conductance-voltage characteristics at room temperature were measured and analyzed as a function of applied frequency (f) ranging from 20 kHz to 2 MHz in order to estimate the series resistance (R s) by the Nicollian-Brews method. R s was estimated as 77.79 Ω at 20 kHz. It decreased to 14.16 Ω at 2 MHz, which is expected because the charges at the interface states cannot follow the AC signal at high f values.

  11. Series resistance and gate leakage correction for improved border trap analysis of Al2O3/InGaAs gate stacks

    NASA Astrophysics Data System (ADS)

    Tang, K.; Scheuermann, A. G.; Zhang, L.; McIntyre, P. C.

    2017-09-01

    As the size of electronic devices scales down, series resistance (RS) and gate leakage effects are commonly observed in electrical measurement of metal-oxide-semiconductor gate stacks. As a result of their effects on device characteristics, these phenomena complicate the analysis of border trap density (Nbt) in the gate insulator using capacitance-voltage (C-V) and conductance-voltage (G-V) measurements. In this work, we develop methods to correct for the effects of RS and gate leakage in Al2O3/InGaAs gate stacks to enable reliable fitting of C-V and G-V data to determine Nbt. When tested using data from Pd/Al2O3/InGaAs gate stacks, the RS correction method successfully removes the RS-induced high frequency dispersion in the accumulation region of the C-V curves and provides an accurate extraction of RS and Nbt. The gate leakage correction method is tested on gate stacks with high gate leakage current of ˜25 μA at 2 V bias, and is found to effectively fit capacitance and conductance data, to achieve consistent Nbt extraction. The compatibility of these two methods is confirmed by analysis of data obtained from gate stacks with both substantial RS and gate leakage.

  12. Climatic factors and community - associated methicillin-resistant Staphylococcus aureus skin and soft-tissue infections - a time-series analysis study.

    PubMed

    Sahoo, Krushna Chandra; Sahoo, Soumyakanta; Marrone, Gaetano; Pathak, Ashish; Lundborg, Cecilia Stålsby; Tamhankar, Ashok J

    2014-08-29

    Skin and soft tissue infections caused by Staphylococcus aureus (SA-SSTIs) including methicillin-resistant Staphylococcus aureus (MRSA) have experienced a significant surge all over the world. Changing climatic factors are affecting the global burden of dermatological infections and there is a lack of information on the association between climatic factors and MRSA infections. Therefore, association of temperature and relative humidity (RH) with occurrence of SA-SSTIs (n = 387) and also MRSA (n = 251) was monitored for 18 months in the outpatient clinic at a tertiary care hospital located in Bhubaneswar, Odisha, India. The Kirby-Bauer disk diffusion method was used for antibiotic susceptibility testing. Time-series analysis was used to investigate the potential association of climatic factors (weekly averages of maximum temperature, minimum temperature and RH) with weekly incidence of SA-SSTIs and MRSA infections. The analysis showed that a combination of weekly average maximum temperature above 33 °C coinciding with weekly average RH ranging between 55% and 78%, is most favorable for the occurrence of SA-SSTIs and MRSA and within these parameters, each unit increase in occurrence of MRSA was associated with increase in weekly average maximum temperature of 1.7 °C (p = 0.044) and weekly average RH increase of 10% (p = 0.097).

  13. Impacts of Coal Seam Gas (Coal Bed Methane) Extraction on Water Resources in Australia

    NASA Astrophysics Data System (ADS)

    Post, David

    2017-04-01

    While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States, in Australia extraction of methane from coal bed methane deposits (termed 'coal seam gas' in Australia) has been the focus to date. The two sources of methane share many of the same characteristics including the potential requirement for hydraulic fracturing. However, as coal seam gas deposits generally occur at shallower depths than shale gas, the potential impacts of extraction on surface and groundwater resources may be of even greater concern. In Australia, an Independent Expert Scientific Committee (IESC) has been established to provide scientific advice to federal and state government regulators on the impact that coal seam gas and large coal mining developments may have on water resources. This advice is provided to enable decisions to be informed by the best available science about the potential water-related impacts associated with these developments. To support this advice, the Australian Government Department of the Environment has implemented a programme of research termed 'bioregional assessments' to investigate these potential impacts. A bioregional assessment is defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are currently being carried out across large portions of eastern Australia underlain by coal reserves. Further details of the programme and results to date can be found at http://www.bioregionalassessments.gov.au. The bioregional assessment programme has modelled the impacts of coal seam gas development on surface and groundwater resources in three regions of eastern Australia, namely the Clarence-Moreton, Gloucester, and Namoi regions. This presentation will discuss the

  14. Impacts of Coal Seam Gas (Coal Bed Methane) Extraction on Water Resources in Australia

    NASA Astrophysics Data System (ADS)

    Post, David

    2016-04-01

    While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States and Europe, in Australia extraction of methane from coal bed methane deposits (termed 'coal seam gas' in Australia) has been the focus to date. The two sources of methane share many of the same characteristics including the potential requirement for hydraulic fracturing. However, as coal seam gas deposits generally occur at shallower depths than shale gas, the potential impacts of extraction on surface and groundwater resources may be of even greater concern. In Australia, an Independent Expert Scientific Committee (IESC) has been established to provide scientific advice to federal and state government regulators on the impact that coal seam gas and large coal mining developments may have on water resources. This advice is provided to enable decisions to be informed by the best available science about the potential water-related impacts associated with these developments. To support this advice, the Australian Government Department of the Environment has implemented a programme of research termed 'bioregional assessments' to investigate these potential impacts. A bioregional assessment is defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are currently being carried out across large portions of eastern Australia underlain by coal reserves. Further details of the programme and results to date can be found at http://www.bioregionalassessments.gov.au. Surface water and groundwater modelling is now complete for two regions where coal seam gas development may proceed, namely the Clarence-Moreton and Gloucester regions in eastern New South Wales. This presentation will discuss how the results of these

  15. Simulation of Double-Seaming in a Two-piece Aluminum Can

    NASA Astrophysics Data System (ADS)

    Romanko, Anne; Berry, Dale; Fox, David

    2004-06-01

    The aluminum can industry in the United States and Canada manufactures over 100 billion cans per year. Two-piece aluminum cans are commonly used to seal and deliver foodstuffs such as soft drinks, beer, pet food, and other perishable items. In order to ensure product safety and performance, the double seam between the can body and lid is a critical component of the package. Double-seaming is a method by which the flange of the can body and the curl of the end are folded over together such that the final joint is composed of five metal thicknesses. There are a number of design challenges involved with the art of double seaming, especially with the push to lightweight. Although the requirements vary by product, the typical beer package must be able to hold pressures in excess of 90psi. In addition, in production, double seaming is a high-speed operation with speeds as high as 3000 cans/minute on an 18-spindle seamer. For this high volume, low cost industry, understanding and optimizing the seaming process can advance the industry as well as help prevent various manufacturing problems that produce a poor seal between the two pieces of the can. To aid in understanding the mechanics of the can parts during double-seaming, a simulation procedure was developed and carried out on a 202 diameter beverage can and lid. Simulations were run with the explicit dynamics solver ABAQUS/Explicit using the continuum shell element technology available in the ABAQUS general purpose FEA program. The continuum shell is a shear-deformable shell element with the topology of an eight node brick. The element's formulation allows continuously varying, solution-dependent shell thickness and through-thickness pinching stress. One important advantage of using the continuum shell as opposed to a traditional shell element is that true contact interactions at the top and bottom surfaces of the can body and lid can be accurately modeled. With a conventional shell element, contact is performed at the

  16. Assessment of uncertainty and degasification efficiency in coal seam gas drainage through stochastic reservoir simulation

    NASA Astrophysics Data System (ADS)

    Özgen Karacan, C.

    2016-04-01

    Coal seam degasification improves coal mine safety by reducing the gas content of coal seams and also by generating added value as an energy source. Coal bed reservoir simulation, as a reservoir management and forecasting tool, is one of the most effective ways to help with these two main objectives. However, as in all modeling and simulation studies, reservoir description and whether observed productions can be predicted are important considerations. Using geostatistical realizations as spatial maps of different coal reservoir properties is a more realistic approach than assuming uniform properties across the field. In fact, this approach can help with simultaneous history matching of multiple wellbores to enhance the confidence in spatial models of different coal properties that are pertinent to degasification. The problem that still remains, however, is the uncertainty in geostatistical, and thus reservoir, simulations originating from partial sampling of the seam that does not properly reflect the stochastic nature of coal property realizations. This study demonstrates the use of geostatistical realizations generated through sequential Gaussian simulation and co-simulation techniques and assesses the uncertainty in coal seam reservoir simulations with history matching errors. 100 individual realizations of 10 coal properties were generated using geostatistical techniques. These realizations were used to create 100 realization bundles (property datasets). Each of these bundles was then used in coal seam reservoir simulations for simultaneous history matching of degasification wells. History matching errors for each bundle were evaluated and the single set of realizations that would minimize the error for all wells was defined. Errors were compared with those of E-type and the average realization of the best matches. The study helped to determine the realization bundle that consisted of the spatial maps of coal properties, which resulted in minimum error. In

  17. Impacts of Coal Seam Gas (Coal Bed Methane) Extraction on Water Resources in Australia

    NASA Astrophysics Data System (ADS)

    Post, David

    2015-04-01

    While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States and Europe, in Australia extraction of methane from coal bed methane deposits (termed 'coal seam gas' in Australia) has been the focus to date. The two sources of methane share many of the same characteristics including the potential requirement for hydraulic fracturing. However as coal seam gas deposits generally occur at shallower depths than shale gas the potential impacts of extraction and hydraulic fracturing on surface and groundwater resources may be of even greater concern for coal seam gas than for shale gas. In Australia an Independent Expert Scientific Committee (IESC) has been established to provide scientific advice to federal and state government regulators on the impact that coal seam gas and large coal mining developments may have on water resources. This advice is provided to enable decisions to be informed by the best available science about the potential water-related impacts associated with these developments. To support this advice the Australian Government Department of the Environment has implemented a three-year programme of research termed 'bioregional assessments' to investigate these potential impacts. A bioregional assessment is defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are currently being carried out across large portions of eastern Australia underlain by coal reserves. Further details of the program and results to date can be found at http://www.bioregionalassessments.gov.au. In this presentation the methodology for undertaking bioregional assessments will be described and the application of this methodology to six priority bioregions in eastern Australia

  18. Numerical simulation of geomechanical state of coal massif in the vicinity of underground workings in the superimposed seams

    NASA Astrophysics Data System (ADS)

    Tsvetkov, A. B.; Pavlova, L. D.; Fryanov, V. N.

    2017-09-01

    The results of numerical modeling of stresses distribution in the formation of coal seams, mined successively in a descending order are presented. The variant is considered, in which the working of the upper seam is carried out in advance and the selvages of the mine workings in the tapped and overworked seam are located in zones of increased rock pressure and unloading, which creates dangerous conditions for mining operations. A mathematical model of stress-strain state of the geomassif in the form of a boundary-value problem, which was solved by the finite element method. Computational experiments were carried out to assess the mutual influence of excavations in the superimposed seams. The zones of increased rock pressure are determined within which the most dangerous geomechanical situation arises. The evaluation of the conformity of the numerical simulation results with the requirements of normative documents is performed. The proposed approach is recommended for the development of project documentation.

  19. Detecting voids in a 0.6 m coal seam, 7 m deep, using seismic reflection

    USGS Publications Warehouse

    Miller, R.D.; Steeples, D.W.

    1991-01-01

    Surface collapse over abandoned subsurface coal mines is a problem in many parts of the world. High-resolution P-wave reflection seismology was successfully used to evaluate the risk of an active sinkhole to a main north-south railroad line in an undermined area of southeastern Kansas, USA. Water-filled cavities responsible for sinkholes in this area are in a 0.6 m thick coal seam, 7 m deep. Dominant reflection frequencies in excess of 200 Hz enabled reflections from the coal seam to be discerned from the direct wave, refractions, air wave, and ground roll on unprocessed field files. Repetitive void sequences within competent coal on three seismic profiles are consistent with the "room and pillar" mining technique practiced in this area near the turn of the century. The seismic survey showed that the apparent active sinkhole was not the result of reactivated subsidence but probably erosion. ?? 1991.

  20. Exploratory study of some potential environmental impacts of CO2 sequestration in unmineable coal seams

    SciTech Connect

    Hedges, S.W.; Soong, Y.; Jones, R.J.; Harrison, D.K.; Irdi, G.A.; Frommell, E.A.; Dilmore, R.M.; White, C.M.

    2007-01-01

    An initial investigation into the potential environmental impacts of CO2 sequestration in unmineable coal seams has been conducted, focusing on changes in the produced water during enhanced coalbed methane (ECBM) production, using a CO2 injection process (CO2-ECBM). A high volatile bituminous coal, Pittsburgh No. 8, was reacted with synthetic produced water and gaseous carbon dioxide at 40°C and 50 bar to evaluate the potential for mobilisation of toxic metals during CO2-ECBM/sequestration. Microscopic and X-ray diffraction analysis of the post-reaction coal samples clearly show evidence of chemical reaction and chemical analysis of the synthetic produced water shows substantial changes in composition. These results suggest that changes to the produced water chemistry and the potential for mobilising toxic trace elements from coal beds are important factors to be considered when evaluating deep, unmineable coal seams for CO2 sequestration.

  1. Laser Ablation Cleaning of Self-Reacting Friction Stir Weld Seam Surfaces: A Preliminary Evaluation

    NASA Technical Reports Server (NTRS)

    Nunes, A. C., Jr.; Russell, C. K.; Brooke, S. A.; Parry, Q.; Lowrey, N. M.

    2014-01-01

    Anodized aluminum panels were cleaned by three lasers at three separate sites with a view to determining whether more economical laser cleaning might supplant current manual cleaning methods for preparation of surfaces to be welded by the self-reacting friction stir process. Uncleaned panels yielded welds exhibiting residual oxide defect (ROD) and failing at very low stresses along the trace of the weld seam. Manually cleaned panels yielded welds without ROD; these welds failed at nominal stress levels along an angled fracture surface not following the weld seam trace. Laser cleaned panels yielded welds failing at intermediate stress levels. The inadequacy of the laser cleaning processes leaves questions: Was the anodized aluminum test too stringent to represent actual cleaning requirements? Were the wrong laser cleaning techniques/parameters used for the study? Is the laser cleaning mechanism inadequate for effective preweld surface cleaning?

  2. Degradation of a Multilayer Insulation Due to a Seam and a Penetration

    NASA Technical Reports Server (NTRS)

    Sumner, I. E.

    1976-01-01

    The degradation of the thermal performance of a multilayer insulation due to the presence of a seam and a penetration was studied. The multilayer insulation had 30 aluminized Mylar radiation shields with silk net spacers. The seam, an offset butt joint, caused a heat input of 0.169 watt per meter in addition to the basic insulation thermal performance of 0.388 watt per square meter obtained before the installation of the butt joint. The penetration, a fiberglass tank support strut, provided a heat input (including the degradation of the insulation) of 0.543 watt in addition to the basic insulation thermal performance of 0.452 watt per square meter obtained before the penetration.

  3. Short-lasting accumulation in osteoid bone seams of radioactive iron injected as citrate into mice.

    PubMed

    Huser, H; Gerber, L; Eichenberger, P; Waelti, E; Cottier, H

    1988-05-01

    The possible role in vivo of osseous structures in binding radioactive iron injected as a low-molecular-weight complex was studied in mice, using combined autoradiography and histomorphometry on sections of undecalcified, plastic-embedded femur epiphyses/metaphyses. A single intraperitoneal injection of 10 microCi 59Fe (1.2 micrograms Fe) per animal as citrate within 3 hours led to a preferential accumulation of this metal in the osteoid mineralized tissue interphase (osteoid seams) of bone. Within the next 2 days the labeling intensity in this localization diminished markedly to approximate levels of the bone marrow and calcified bone. The bulk of the injected radioiron was utilized according to known erythrokinetics. Findings suggest a direct entry of "free," ie, not transferrin-bound, iron into osteoid seams and its consecutive rapid removal from this site.

  4. Megaspores from the Late Permian, Lower Whybrow coal seam, Sydney Basin, Australia.

    PubMed

    Glasspool

    2000-07-01

    More than 300 megaspore specimens have been recovered from samples from the Late Permian, Lower Whybrow coal seam of the Wittingham Coal Measures of the Sydney Basin. Only two species are recognised: Singhisporites surangei (Singh) Potonié, emend. and a new species of Singhisporites. Species distribution within the seam is controlled by a major fire event, as recognised by coal petrology and mesofossil content: Singhisporites surangei is dominant before the event, but following it, it is subordinate to the new species.The abundance of megaspores recovered has allowed recognition of the full range of morphologic variation of Singhisporites surangei, which encompasses specimens assigned previously to Singraulispora Pant & Mishra, 1986 and Mammilaespora Pant & Srivastava, 1961; both are regarded as junior synonyms of Singhisporites Potonié, emend. Ultrastructurally, the new species shows affinities with Mesozoic isoetalean megaspores.

  5. Demonstration of longwall mining in a steeply dipping coal seam. Research report, September 1977-May 1986

    SciTech Connect

    Kennedy, M.R.; Reschke, L.M.

    1987-01-01

    This report describes the demonstration of longwall mining in a seam dipping 27 deg to 34 deg. Equipment was selected on the basis of capability, compatibility, and cost. The longwall equipment operated very well on the steep pitch with an average equipment downtime of 21.9%. Coal handling out by the face was a problem that caused an additional downtime of 19.5%. Development for the panels proved to be the major problem in the economics of longwall mining on a steeply dipping seam. During the first 9 months of operation, the longwall averaged 71.9 tons per man-shift (TPMS) and development averaged 0.6 TPMS. for an overall average of 14.1 TPMS.

  6. A seam tracking modulated infrared optical sensor for use in welding

    NASA Astrophysics Data System (ADS)

    Wu, Minsheng; Chen, Wuzhu; He, Fangdian; Yan, Bingyi; Su, Yong

    1991-12-01

    This article describes a weld seam tracking sensor which has a type of pulse modulated infrared beam as its signal light source. Going through signal reception filters and 'adaptive elimination of noise' processing, it is possible to effectively overcome interference from electric arc light. Making use of the light source pulse driven characteristics, the instantaneous signal power is greatly added to, improving the adaptation of optical sensors to the surfaces of pieces of work. The sensors' structure is simple. Their volume is small. Their sensitivity is high. Additionally, they are capable of realizing, at the same time, automatic tracking of weld seams in the two horizontal and altitude directions. It is capable of precision tracking in both submerged arc and open arc automatic welding.

  7. Suppression of gradient across seam line using a smoothing filter in spatially compounded ultrasonic diagnostic images.

    PubMed

    Choi, Myoung Hwan

    2007-01-01

    A method to reduce seam line artifact in spatial compounding of ultrasonic images is presented. Spatial compounding is a speckle reducing imaging technique in which a number of ultrasound images of a given target that have been obtained from multiple view angles are combined into a single compounded image by combining the data received from each data point in the compounded image. Since different view angle results in different view area, and the images of different view areas are combined into an image, the compounded image consists of regions with different signal to noise ratio, and the boundary lines between these regions are visible in the compounded images. In this paper, we present an algorithm that effectively reduces the visibility of this seam line in the spatially compounded images. Design procedure for a smoothing filter is described and the results of applying the filter to in-vivo ultrasonic images are analyzed.

  8. Interaction of compaction near mine openings and drainage of pore fluids from coal seams

    SciTech Connect

    Smelser, R.E.

    1984-02-01

    The long range transport of gas and water through coal seams is generally thought to occur through the natural fracture network of cleats in the coal seam. During mining, the overburden load is transferred from the coal to the nearby pillars and abutments which yield, or deform plastically, close to the mine openings. Stresses acting to deform are also influenced by changes in the fluid pressure in the natural fracture network. In the present work, a model of the yield region is developed, taking account of changes in the pressure (drainage) of fluids in the normal fracture network. Changes in porosity and permeability resulting from additional microfracturing in the yield zone are calculated based on this model.

  9. Modeling and Simulation of Coal Loading by Cutting Drum in Flat Seams

    NASA Astrophysics Data System (ADS)

    Gospodarczyk, Piotr

    2016-06-01

    This paper presents a methodology for modeling work of a coal shearer work in low longwall coal seams where the wall height does not exceed 1.5 m. In such conditions, an important issue is the process of loading the ore from shearer cutting drum on an armored face conveyor and selection of appropriate kinematic parameters to avoid choking. Discrete element method was used to model coal seam. This method allows for efficient simulation of physical systems composed of many separate components. Methods and algorithms based on existing theoretical models were developed to imitate coal cutting process. Main focus of analysis was put on coal stream movement for different variants of the shearer construction and kinematic parameters.

  10. 3D real-time measurement system of seam with laser

    NASA Astrophysics Data System (ADS)

    Huang, Min-shuang; Huang, Jun-fen

    2014-02-01

    3-D Real-time Measurement System of seam outline based on Moiré Projection is proposed and designed. The system is composed of LD, grating, CCD, video A/D, FPGA, DSP and an output interface. The principle and hardware makeup of high-speed and real-time image processing circuit based on a Digital Signal Processor (DSP) and a Field Programmable Gate Array (FPGA) are introduced. Noise generation mechanism in poor welding field conditions is analyzed when Moiré stripes are projected on a welding workpiece surface. Median filter is adopted to smooth the acquired original laser image of seam, and then measurement results of a 3-D outline image of weld groove are provided.

  11. Ab Initio Trajectory Study on Triplet Ketene Photodissociation via Statistical Sampling of the Crossing Seam.

    PubMed

    Ogihara, Yusuke; Yamamoto, Takeshi; Kato, Shigeki

    2011-08-09

    Triplet ketene exhibits a steplike structure in the experimentally observed dissociation rate, but its mechanism is still unclear despite many theoretical efforts. A previous surface-hopping simulation at the CASSCF level suggests that nonadiabatic transition from the S0 to T1 states creates the T1 species in a highly nonstatistical manner, which raises the question of whether the use of statistical rate theory is valid in itself for the T1 state. Here, we study this problem by performing ab initio trajectory simulation at the multireference second-order Möller-Plesset perturbation (MRMP) level of theory. Since the MRMP theory is too expensive for such a trajectory calculation, we first construct dual-level potential energy surfaces (PESs) for the S0 and T1 states by calibrating the PESs at the B3LYP level with a limited set of MRMP energies. We then introduce the assumption of vibrational equilibrium on the S0 surface and characterize the S0 → T1 crossing points using the conditional microcanonical distribution on the S0/T1 seam surface. The latter distribution is obtained by running a constrained trajectory on the seam surface by use of an efficient SHAKE-like method. Subsequently, we propagate a number of T1 trajectories from the seam surface to obtain the dissociation rate. The result shows that (i) the S0 → T1 crossing points are localized mainly in the T1 reactant region; (ii) the lifetime on the T1 surface is about 30 ps at the MRMP level, which is 2 orders of magnitude greater than the previous estimate obtained from the surface-hopping simulation at the CASSCF level (∼100 fs); and (iii) the calculated T1 dissociation rate agrees reasonably well with classical transition state theory. These results suggest that the T1 dissociation is rather statistical, given that the T1 trajectories are initiated from the conditional microcanonical distribution on the seam surface.

  12. Dynamics of nonadiabatic reactions (theory). I. Branching ratios for early and late seams

    NASA Astrophysics Data System (ADS)

    Mayne, H. R.; Polanyi, J. C.; Tully, J. C.

    1985-01-01

    The 3D classical trajectory surface hopping (TSH) method has been applied in a ``model'' study of factors governing nonadiabatic reaction, A+BC→AB+C* and →AB+C. In the diabatic approximation the potential-energy surfaces (pes) were a LEPS surface for F+H2 (→AB+C*) and a repulsive pes Vrep (→AB+C). These intersected in the exit valley to give an early or a late seam (E or L, perpendicular to the exit valley). The splitting at the avoided crossing 2ɛ was adjusted to ɛ=1.26 or 5.02 kcal/mol. The ratio of reactive cross sections onto the upper and lower adiabatic pes ρ* was investigated for mass combinations H+HL, L+HL, L+HH, and H+LL with E and L seams, and for small and large ɛ. The effect on ρ* of reapportioning a constant total energy (ETOT=13.84 kcal/mol) between reagent translation T and vibration V was examined for these 16 cases. Since the velocity in the coordinate of separation increased with increased T (yielding increased product translation; ΔT→ΔT') ρ* also tended to increase with T. The extreme mass combinations H+HL and L+HH exhibited modified ρ* due to markedly differing widths in the entry and exit valley. The strongly skewed pes for H+LL led to multiple crossing of the seam which reduced ρ*. For other mass combinations ρ* was reduced by the inability of the low T' component of the product to hop across the 2ɛ gap. In all cases ρ* was an index of the local dynamics at the seam, and hence shed light on the intermediate motions en route to the asymptotic outcome V', R', T'.

  13. Sample preparation method for glass welding by ultrashort laser pulses yields higher seam strength

    SciTech Connect

    Cvecek, K.; Miyamoto, I.; Strauss, J.; Wolf, M.; Frick, T.; Schmidt, M.

    2011-05-01

    Glass welding by ultrashort laser pulses allows joining without the need of an absorber or a preheating and postheating process. However, cracks generated during the welding process substantially impair the joining strength of the welding seams. In this paper a sample preparation method is described that prevents the formation of cracks. The measured joining strength of samples prepared by this method is substantially higher than previously reported values.

  14. Permeability Prediction in Deep Coal Seam: A Case Study on the No. 3 Coal Seam of the Southern Qinshui Basin in China

    PubMed Central

    2013-01-01

    The coal permeability is an important parameter in mine methane control and coal bed methane (CBM) exploitation, which determines the practicability of methane extraction. Permeability prediction in deep coal seam plays a significant role in evaluating the practicability of CBM exploitation. The coal permeability depends on the coal fractures controlled by strata stress, gas pressure, and strata temperature which change with depth. The effect of the strata stress, gas pressure, and strata temperature on the coal (the coal matrix and fracture) under triaxial stress and strain conditions was studied. Then we got the change of coal porosity with strata stress, gas pressure, and strata temperature and established a coal permeability model under tri-axial stress and strain conditions. The permeability of the No. 3 coal seam of the Southern Qinshui Basin in China was predicted, which is consistent with that tested in the field. The effect of the sorption swelling on porosity (permeability) firstly increases rapidly and then slowly with the increase of depth. However, the effect of thermal expansion and effective stress compression on porosity (permeability) increases linearly with the increase of depth. The most effective way to improve the permeability in exploiting CBM or extracting methane is to reduce the effective stress. PMID:24396293

  15. Permeability prediction in deep coal seam: a case study on the No. 3 coal seam of the Southern Qinshui Basin in China.

    PubMed

    Guo, Pinkun; Cheng, Yuanping

    2013-01-01

    The coal permeability is an important parameter in mine methane control and coal bed methane (CBM) exploitation, which determines the practicability of methane extraction. Permeability prediction in deep coal seam plays a significant role in evaluating the practicability of CBM exploitation. The coal permeability depends on the coal fractures controlled by strata stress, gas pressure, and strata temperature which change with depth. The effect of the strata stress, gas pressure, and strata temperature on the coal (the coal matrix and fracture) under triaxial stress and strain conditions was studied. Then we got the change of coal porosity with strata stress, gas pressure, and strata temperature and established a coal permeability model under tri-axial stress and strain conditions. The permeability of the No. 3 coal seam of the Southern Qinshui Basin in China was predicted, which is consistent with that tested in the field. The effect of the sorption swelling on porosity (permeability) firstly increases rapidly and then slowly with the increase of depth. However, the effect of thermal expansion and effective stress compression on porosity (permeability) increases linearly with the increase of depth. The most effective way to improve the permeability in exploiting CBM or extracting methane is to reduce the effective stress.

  16. Laser welding process in PP moulding parts: Evaluation of seam performance

    NASA Astrophysics Data System (ADS)

    Oliveira, N.; Pontes, A. J.

    2015-12-01

    The Polypropylene is one of the most versatile polymer materials used in the industry. Due to this versatility, it is possible to use it in different products. This material can also be mixed with several additives namely glass fiber, carbon nanotubes, etc. This compatibility with different additives allows also obtaining products with characteristics that goes from an impact absorber to an electricity conductor. When is necessary to join components in PP they could be welded through hot plate, ultrasonic weld and also by laser. This study had the objective of study the influence of several variables, capable of influence the final quality of the seam. In this case were studied variables of the injection molding process as mold temperature and cooling time. Was also studied laser welding variables and different materials. The results showed that the variables that have the most influence were mould temperature, laser velocity and laser diameter. The seams were analyzed using Optical Microscopy technique. The seams showed perfect contact between the materials analyzed, despite the high standard variation presented in the mechanical testes.

  17. An analysis of injury claims from low-seam coal mines

    SciTech Connect

    Gallagher, S.; Moore, S.; Dempsey, P.G.

    2009-07-01

    The restricted workspace present in low-seam coal mines forces workers to adopt awkward working postures (kneeling and stooping), which place high physical demands on the knee and lower back. This article provides an analysis of injury claims for eight mining companies operating low-seam coal mines during calendar years 1996-2008. All cost data were normalized using data on the cost of medical care (MPI) as provided by the U.S. Bureau of Labor Statistics. Results of the analysis indicate that the knee was the body part that led in terms of claim cost ($4.2 million), followed by injuries to the lower back ($2.7 million). While the average cost per injury for these body parts was $13,100 and $14,400, respectively (close to the average cost of an injury overall), the high frequency of these injuries resulted in their pre-eminence in terms of cost. Analysis of data from individual mining companies suggest that knee and lower back injuries were a consistent problem across companies, as these injuries were each among the top five most costly part of body for seven out of eight companies studied. Results of this investigation suggest that efforts to reduce the frequency of knee and low back injuries in low-seam mines have the potential to create substantial cost savings.

  18. Type IIP supernovae as cosmological probes: A SEAM distance to SN1999em

    SciTech Connect

    Baron, E.; Nugent, Peter E.; Branch, David; Hauschildt, Peter H.

    2004-06-01

    Because of their intrinsic brightness, supernovae make excellent cosmological probes. We describe the spectral-fitting expanding atmosphere method (SEAM) for obtaining distances to Type IIP supernovae (SNe IIP) and present a distance to SN 1999em for which a Cepheid distance exists. Our models give results consistent with the Cepheid distance, even though we have not attempted to tune the underlying hydrodynamical model but have simply chosen the best fits. This is in contradistinction to the expanding photosphere method (EPM), which yields a distance to SN 1999em that is 50 percent smaller than the Cepheid distance. We emphasize the differences between the SEAM and the EPM. We show that the dilution factors used in the EPM analysis were systematically too small at later epochs. We also show that the EPM blackbody assumption is suspect. Since SNe IIP are visible to redshifts as high as z {approx}< 6, with the James Webb Space Telescope, the SEAM may be a valuable probe of the early universe.

  19. Laser ultrasound: a flexible tool for the inspection of complex CFK components and welded seams

    NASA Astrophysics Data System (ADS)

    von Kopylow, Christoph; Focke, Oliver; Kalms, Michael

    2007-06-01

    Modern production processes use more and more components made of new materials like carbon fiber reinforced plastics (CFRP). These components have different sizes, functionalities, high assembly complexity and high security requirements. In addition optimized joining processes, especially during welding are implemented in manufacturing processes. The increasing requirements during the manufacturing of complex products like cars and aircrafts demand new solutions for the quality assurance. The main focus is to find a measurement strategy that is cost effective, flexible and adaptive. The extension of the conventional ultrasound technique for non destructive testing with the laser ultrasound method brings new possibilities into the production processes for example for the inspection of small complex CFRP-parts like clips and the online observation during seam welding. In this paper we describe the principle of laser ultrasound, especially the adaptation of a laser ultrasound system to the requirements of non destructive testing of CFRP-components. An important point is the generation of the ultrasound wave in the surface of the component under investigation. We will show experimental results of different components with complex shape and different defects under the surface. In addition we will present our results for the detection of defects in metals. Because the online inspection of welded seams is of high interest experiments for the investigation of welded seams are demonstrated.

  20. Petrographic analyses of Knobloch coal seam (Paleocene), Powder River County, southeastern Montana

    SciTech Connect

    Daniel, J.A.

    1986-08-01

    A single core of Knobloch coal from Powder River County, southeast Montana, was drilled to obtain samples for coal quality studies. The coal occurs in the lower Tongue River Member of the Paleocene Fort Union Formation. The Knobloch coal core (63 ft long) was divided into 1-ft increments and analyzed using chemical and petrographic methods. Definite variations in maceral content were seen. Preliminary studies show relationship between ash, gelinite, inertinite, and humodetrinite contents. A zone of low gelinite, low humodetrinite, and high inertinite, located in the lower quarter of the seam, implies a period of severe oxidation occurred, possibly as swamp fires. Four zones of high inertinite and high humodetrinite (three in the upper half and one in the lower half of the seam) indicate fluctuations in the water table, allowing moderate oxidation and weathering of plant material and subsequent mechanical reworking of humic grains. Near the center of the seam, a zone of high inertinite, high humodetrinite, and high ash content suggests water levels were high enough to allow significant sediment influx as well as reworking of the humic materials. These conclusions suggest the Knobloch coal is autochthonous and hypautochthonous in origin, a result of several water-table fluctuations and/or climatic changes due to drought.

  1. Relations between coal petrology and gas content in the Upper Newlands Seam, Central Queensland, Australia

    USGS Publications Warehouse

    Walker, R.; Glikson, M.; Mastalerz, Maria

    2001-01-01

    The Upper Newlands Seam in the northern Bowen Basin, Queensland Australia consists of six benches (A-F) that have different petrographic assemblages. Benches C and E contain relatively abundant inertodetrinite and mineral matter, as well as anomalously high reflectance values; these characteristics support a largely allochthonous, detrital origin for the C and E benches. Fractures and cleats in the seam show a consistent orientation of northeast-southwest for face cleats, and a wide range of orientations for fractures. Cleat systems are well developed in bright bands, with poor continuity in the dull coal. Both maceral content and cleat character are suggested to influence gas drainage in the upper Newlands Seam. A pronounced positive correlation between vitrinite abundance and gas desorption data suggests more efficient drainage from benches with abundant vitrinite. Conversely, inertinite-rich benches are suggested to have less efficient drainage, and possibly retain gas within pore spaces, which could increase the outburst potential of the coal. ?? 2001 Elsevier Science B.V. All rights reserved.

  2. The influence of hydrogeological disturbance and mining on coal seam microbial communities.

    PubMed

    Raudsepp, M J; Gagen, E J; Evans, P; Tyson, G W; Golding, S D; Southam, G

    2016-03-01

    The microbial communities present in two underground coal mines in the Bowen Basin, Queensland, Australia, were investigated to deduce the effect of pumping and mining on subsurface methanogens and methanotrophs. The micro-organisms in pumped water from the actively mined areas, as well as, pre- and post-mining formation waters were analyzed using 16S rRNA gene amplicon sequencing. The methane stable isotope composition of Bowen Basin coal seam indicates that methanogenesis has occurred in the geological past. More recently at the mine site, changing groundwater flow dynamics and the introduction of oxygen in the subsurface has increased microbial biomass and diversity. Consistent with microbial communities found in other coal seam environments, pumped coal mine waters from the subsurface were dominated by bacteria belonging to the genera Pseudomonas and the family Rhodocyclaceae. These environments and bacterial communities supported a methanogen population, including Methanobacteriaceae, Methanococcaceae and Methanosaeta. However, one of the most ubiquitous micro-organisms in anoxic coal mine waters belonged to the family 'Candidatus Methanoperedenaceae'. As the Archaeal family 'Candidatus Methanoperedenaceae' has not been extensively defined, the one studied species in the family is capable of anaerobic methane oxidation coupled to nitrate reduction. This introduces the possibility that a methane cycle between archaeal methanogenesis and methanotrophy may exist in the anoxic waters of the coal seam after hydrogeological disturbance.

  3. Time-series analysis of the impact of bed occupancy rates on the incidence of methicillin-resistant Staphylococcus aureus infection in overcrowded general wards.

    PubMed

    Borg, Michael A; Suda, David; Scicluna, Elizabeth

    2008-06-01

    We investigated the impact of bed occupancy, particularly overcrowding, on the incidence of methicillin-resistant Staphylococcus aureus (MRSA) infection in general ward settings. We performed a time-series and mixed-model analysis of variance of monthly incidence of MRSA infection and corresponding bed occupancy rates, over 65 months, in the medicine and surgical wards within St. Luke's Hospital, a 900-bed tertiary care facility in Malta. In the medicine wards, significant periodic fluctuations in bed demand were evident during the study period, with peaks of occupancy greater than 120% during the winter months. Cross-correlation analysis between the rate of bed occupancy and the rate of MRSA infection displayed an oscillatory configuration, with a periodicity of 12, similar to the periodicity evident in the autocorrelation bed-occupancy pattern. Further statistical analysis by means of analysis of variance confirmed that the months with excessive overcrowding tended to coincide with a significant increase in the rate of MRSA infection, occurring after a lag of approximately 2 months. Identical analysis of equivalent data from the surgical wards also revealed significant fluctuation in the rate of bed occupancy; however, occupancy never exceeded 100%. No cross-correlational relationship with MRSA infection incidence was present. The study data suggest that, in our setting, simple fluctuations in the rate of bed occupancy did not have a direct impact on the incidence of MRSA infection as long as the rate of bed occupancy was within designated levels. Rather, it was episodes of significant overcrowding, with occupancy levels in excess of designated numbers, that triggered increases in infection incidence rates.

  4. Determination of the limit of oxidation in zones of sub-outcropping Chipanga Coal Seam, Moatize Coal Basin, Mozambique

    NASA Astrophysics Data System (ADS)

    Vasconcelos, Lopo; Chafy, Algy; Xerinda, Leonardo

    2014-11-01

    Moatize Coal Basin (MCB) in Mozambique is a graben with sediments of Karoo age with thick coal seams that are under exploration and exploitation by the Vale Moçambique company. Presently, the exploitation is as an open-pit mine and in the future the works will extend to the area where formerly underground mines were under exploitation. It is well known throughout the World that Moatize basin is a World class deposit for coking and thermal coal and therefore Vale Moçambique is developing studies to rationalize the coal resources of the area. Due to its geological and tectonic story, the general structure of the sedimentary (and coal) layers shows wide open synclines and anticlines, and, as a consequence, in many areas coal seams approach the surface or even outcrop. Therefore, the sub-outcropping/outcropping zones of the seams are subjected directly to the weathering agents, subjecting the coal to oxidation phenomena, which are considered as a factor altering negatively the coking properties of coals. The objective is to study down to which depth the oxidation zone goes, i.e., to trace the Line of Oxidation, also known as LOX. The study deals with Chipanga seam, which is the thickest of all seams and the one with a more wide representation throughout the graben. This seam also sub-outcrops/outcrops in many places, and therefore it is essential to define the LOX. A drilling and coal sampling campaign was then developed along profiles defined according to the seam dip to determine the depth at which the LOX is located. Samples were subjected to washability tests, and the crucible swelling index (CSI) of the Float 1.35 was determined. The study shows a direct relationship between the depth of the Chipanga seam and its degree of oxidation, shown by the sudden decrease of the CSI when the coal seam approaches the surface. The sudden change of CSI generally occurs at a depth of ca. 10 m, with small variations around this value. Therefore it can be said that the depth of

  5. Comparison between the lengths of individual osteoid seams and resorption cavities in human iliac crest cancellous bone.

    PubMed

    Yamaguchi, K; Croucher, P I; Compston, J E

    1993-10-01

    The current concept of bone remodelling is based on the belief that bone resorption and formation are coupled both in time and space; this implies that the surface extent of bone eroded in a bone remodelling unit would approximate to the surface extent of the osteoid seam formed subsequently. The greater total surface extent of osteoid as opposed to erosion is generally attributed to the longer life-span of bone formation, but no comparison of the length of eroded surface and osteoid seam within individual bone remodelling units has been reported. In this study we have compared the length of individual osteoid seams, resorption cavities and bone structural units in iliac crest trabecular bone obtained from normal subjects and from patients with renal osteodystrophy. Values for osteoid seam and bone packet length were significantly greater than resorption cavity length in both the normal and patient groups (P < 0.001), the ratio of osteoid seam and eroded length being similar in the two groups (1:0.44 and 1:0.40, respectively). These results indicate that the discrepancy between total osteoid and eroded surface extent cannot be wholly explained on the basis of a longer formation life-span. Possible additional explanations include underestimation of eroded surface by light microscopic techniques, initiation of bone formation within a cavity before the completion of resorption, the presence of arrested resorption cavities, non-random distribution of resorption cavities on the trabecular surface and bone formation on quiescent bone surfaces.

  6. Approach to In- Situ Producing Reinforcing Phase Within an Active-Transient Liquid Phase Bond Seam for Aluminum Matrix Composite

    NASA Astrophysics Data System (ADS)

    Zhang, Guifeng; Liao, Xianjin; Chen, Bo; Zhang, Linjie; Zhang, Jianxun

    2015-06-01

    To optimize the braze composition design route for aluminum matrix composite, the feasibility of in situ producing reinforcing phase within the transient liquid phase bond seam matrix, by adding active melting point increaser (MPI, e.g., Ti) together with general melting point depressant (MPD, e.g., Cu) into the interlayer, was demonstrated. For SiC p /A356 composite, by comparing the wettability, joint microstructure, joint shear strength, and fracture path for the developed Al-19Cu-1Ti, Al-19Cu, Al-33Cu-1Ti, Al-33Cu (wt pct), and commercial Cu foils as interlayer, the feasibility of in situ producing reinforcing phase within the bond seam by adding Ti was demonstrated. Especially for Al-19Cu-1Ti active braze, small and dispersed ternary aluminide of Al-Si-Ti phase was obtained within the bond seam as in situ reinforcement, leading to a favorable fracture path within SiC p /A356, not along the initial interface or within the bond seam. For the formation mechanism of the in situ reinforcing phase of MPI-containing intermetallic compound within the bond seam, a model of repeating concentration-precipitation-termination-engulfment during isothermal solidification is proposed.

  7. The migration law of overlay rock and coal in deeply inclined coal seam with fully mechanized top coal caving.

    PubMed

    Liu, Jian; Chen, Shan-Le; Wang, Hua-Jun; Li, Yu-Cheng; Geng, Xiaowei

    2015-07-01

    In a mine area, some environment geotechnics problems always occure, induced by mined-out region such as the subsidence and cracks at ground level, deformation and destruction of buildings, landslides destruction of water resources and the ecological environment. In order to research the migration of surrounding rock and coal in steeply inclined super high seams which used fully mechanized top coal caving, a working face of a certain mine was made as an example, analyzed the migration law of the overlay rock and coal under different caving ratio of fully mechanized top coal caving with numerical simulation analysis. The results suggest that the laws of overlay rock deformation caused by deeply inclined coal seam were different from horizontal coal seam. On the inclined direction, with an increase of dip angle and caving ratio, the vertical displacement of overlay rock and coal became greater, the asymmetric phenomenon of vertical displacement became obvious. On the trend direction, active region and transition region in goaf became smaller along with the increase of mining and caving ratio. On the contrary, the stable region area became greater. Therefore, there was an essential difference between the mechanism of surface movement deformation with deeply inclined coal seam and that with horizontal coal seam.

  8. C. elegans GATA factors EGL-18 and ELT-6 function downstream of Wnt signaling to maintain the progenitor fate during larval asymmetric divisions of the seam cells

    PubMed Central

    Gorrepati, Lakshmi; Thompson, Kenneth W.; Eisenmann, David M.

    2013-01-01

    The C. elegans seam cells are lateral epithelial cells arrayed in a single line from anterior to posterior that divide in an asymmetric, stem cell-like manner during larval development. These asymmetric divisions are regulated by Wnt signaling; in most divisions, the posterior daughter in which the Wnt pathway is activated maintains the progenitor seam fate, while the anterior daughter in which the Wnt pathway is not activated adopts a differentiated hypodermal fate. Using mRNA tagging and microarray analysis, we identified the functionally redundant GATA factor genes egl-18 and elt-6 as Wnt pathway targets in the larval seam cells. EGL-18 and ELT-6 have previously been shown to be required for initial seam cell specification in the embryo. We show that in larval seam cell asymmetric divisions, EGL-18 is expressed strongly in the posterior seam-fated daughter. egl-18 and elt-6 are necessary for larval seam cell specification, and for hypodermal to seam cell fate transformations induced by ectopic Wnt pathway overactivation. The TCF homolog POP-1 binds a site in the egl-18 promoter in vitro, and this site is necessary for robust seam cell expression in vivo. Finally, larval overexpression of EGL-18 is sufficient to drive expression of a seam marker in other hypodermal cells in wild-type animals, and in anterior hypodermal-fated daughters in a Wnt pathway-sensitized background. These data suggest that two GATA factors that are required for seam cell specification in the embryo independently of Wnt signaling are reused downstream of Wnt signaling to maintain the progenitor fate during stem cell-like divisions in larval development. PMID:23633508

  9. C. elegans GATA factors EGL-18 and ELT-6 function downstream of Wnt signaling to maintain the progenitor fate during larval asymmetric divisions of the seam cells.

    PubMed

    Gorrepati, Lakshmi; Thompson, Kenneth W; Eisenmann, David M

    2013-05-01

    The C. elegans seam cells are lateral epithelial cells arrayed in a single line from anterior to posterior that divide in an asymmetric, stem cell-like manner during larval development. These asymmetric divisions are regulated by Wnt signaling; in most divisions, the posterior daughter in which the Wnt pathway is activated maintains the progenitor seam fate, while the anterior daughter in which the Wnt pathway is not activated adopts a differentiated hypodermal fate. Using mRNA tagging and microarray analysis, we identified the functionally redundant GATA factor genes egl-18 and elt-6 as Wnt pathway targets in the larval seam cells. EGL-18 and ELT-6 have previously been shown to be required for initial seam cell specification in the embryo. We show that in larval seam cell asymmetric divisions, EGL-18 is expressed strongly in the posterior seam-fated daughter. egl-18 and elt-6 are necessary for larval seam cell specification, and for hypodermal to seam cell fate transformations induced by ectopic Wnt pathway overactivation. The TCF homolog POP-1 binds a site in the egl-18 promoter in vitro, and this site is necessary for robust seam cell expression in vivo. Finally, larval overexpression of EGL-18 is sufficient to drive expression of a seam marker in other hypodermal cells in wild-type animals, and in anterior hypodermal-fated daughters in a Wnt pathway-sensitized background. These data suggest that two GATA factors that are required for seam cell specification in the embryo independently of Wnt signaling are reused downstream of Wnt signaling to maintain the progenitor fate during stem cell-like divisions in larval development.

  10. CEH-20/Pbx and UNC-62/Meis function upstream of rnt-1/Runx to regulate asymmetric divisions of the C. elegans stem-like seam cells.

    PubMed

    Hughes, Samantha; Brabin, Charles; Appleford, Peter J; Woollard, Alison

    2013-07-15

    Caenorhabditis elegans seam cells divide in the stem-like mode throughout larval development, with the ability to both self-renew and produce daughters that differentiate. Seam cells typically divide asymmetrically, giving rise to an anterior daughter that fuses with the hypodermis and a posterior daughter that proliferates further. Previously we have identified rnt-1 (a homologue of the mammalian cancer-associated stem cell regulator Runx) as being an important regulator of seam development, acting to promote proliferation; rnt-1 mutants have fewer seam cells whereas overexpressing rnt-1 causes seam cell hyperplasia. We isolated the interacting CEH-20/Pbx and UNC-62/Meis TALE-class transcription factors during a genome-wide RNAi screen for novel regulators of seam cell number. Animals lacking wild type CEH-20 or UNC-62 display seam cell hyperplasia, largely restricted to the anterior of the worm, whereas double mutants have many additional seam cells along the length of the animal. The cellular basis of the hyperplasia involves the symmetrisation of normally asymmetric seam cell divisions towards the proliferative stem-like fate. The hyperplasia is completely suppressed in rnt-1 mutants, and rnt-1 is upregulated in ceh-20 and unc-62 mutants, suggesting that CEH-20 and UNC-62 function upstream of rnt-1 to limit proliferative potential to the appropriate daughter cell. In further support of this we find that CEH-20 is asymmetrically localised in seam daughters following an asymmetric division, being predominantly restricted to anterior nuclei whose fate is to differentiate. Thus, ceh-20 and unc-62 encode crucial regulators of seam cell division asymmetry, acting via rnt-1 to regulate the balance between proliferation and differentiation.

  11. A simple and effective method for portraying and quantifying the macropetrography of lignites: A new tool for coal seam facies analysis

    SciTech Connect

    Sykes, R. ); Pratt, K.C. )

    1994-07-01

    All coal seams contain internal successions of lithologically distinct layers, although the layering in many seams may not be obvious in exposed faces or cores. The layers represent seam facies, and their detailed analysis can provide useful insight into the autogenic and allogenic controls on peat and coal formation. Nevertheless, the facies concept has not been extensively applied to coal seams, and hence the development of coal seam facies models has been slow. A major reason for this has been the lack of established methods for portraying the macropetrographic composition and texture of coal. Accordingly, for the identification and analysis of lithofacies, graphical methods of logging coal seam profiles should portray the vitrain/xylite and fusain components, and enable quantification of their size and content. No existing methods satisfy these requirements because they use symbols to portray coal types (see Bustin et al. 1985, p. 49--61, for selected examples), so the authors have devised a new method for use with lignites, which has proved effective in identifying and characterizing seam lithofacies. The method has been applied to lignite seams in the Ravenscrag Formation (Paleocene) of southern Saskatchewan, Canada. A newly exposed face of one seam and fresh cores of 18 other seams showed only indistinct layering, but dry sawing of the lignites revealed much greater proportions of xylite and fusain and the layering became obvious. The clarity of detail revealed in the sawn faces enabled the xylite, fusain, and coal/clastic contacts to be readily traced, providing true-scale graphic representations of the macropetrography. The representations of individual samples are referred to as lith-graphs whereas those of seam profiles are termed lith-logs.

  12. Adaptability in linkage of soil carbon nutrient cycles - the SEAM model

    NASA Astrophysics Data System (ADS)

    Wutzler, Thomas; Zaehle, Sönke; Schrumpf, Marion; Ahrens, Bernhard; Reichstein, Markus

    2017-04-01

    In order to understand the coupling of carbon (C) and nitrogen (N) cycles, it is necessary to understand C and N-use efficiencies of microbial soil organic matter (SOM) decomposition. While important controls of those efficiencies by microbial community adaptations have been shown at the scale of a soil pore, an abstract simplified representation of community adaptations is needed at ecosystem scale. Therefore we developed the soil enzyme allocation model (SEAM), which takes a holistic, partly optimality based approach to describe C and N dynamics at the spatial scale of an ecosystem and time-scales of years and longer. We explicitly modelled community adaptation strategies of resource allocation to extracellular enzymes and enzyme limitations on SOM decomposition. Using SEAM, we explored whether alternative strategy-hypotheses can have strong effects on SOM and inorganic N cycling. Results from prototypical simulations and a calibration to observations of an intensive pasture site showed that the so-called revenue enzyme allocation strategy was most viable. This strategy accounts for microbial adaptations to both, stoichiometry and amount of different SOM resources, and supported the largest microbial biomass under a wide range of conditions. Predictions of the SEAM model were qualitatively similar to models explicitly representing competing microbial groups. With adaptive enzyme allocation under conditions of high C/N ratio of litter inputs, N in formerly locked in slowly degrading SOM pools was made accessible, whereas with high N inputs, N was sequestered in SOM and protected from leaching. The finding that adaptation in enzyme allocation changes C and N-use efficiencies of SOM decomposition implies that concepts of C-nutrient cycle interactions should take account for the effects of such adaptations. This can be done using a holistic optimality approach.

  13. Design of optimum coal-preparation systems for Missouri coal seams. Final report

    SciTech Connect

    Erten, M.H.; Evans, J.J.; Lounsbury, P.J.; Holloran, R.A.

    1982-08-01

    The objectives of this research were (1) with the use of washability curves and other data, to design suitable coal preparation systems that will provide marketable coals with maximum yield and minimum ash and sulfur contents for raw coals obtained from different Missouri coal seams, and (2) to test the performance of units comprising the systems (flowsheets) with the use of the equipment available at the Mineral and Coal Preparation Laboratories of the University of Missouri at Rolla. On each channel sample, proximate analysis, float and sink, tabling, flotation, hydrocyclone, and forms of sulfur tests were conducted. Because of the limited quantities of core samples, only such tests as proximate analysis, washability, and forms of sulfur could be performed. A survey of the mining operations in the state of Missouri showed that at least six companies worked more than one seam at any time of the year and that most of the coal mined was direct-shipped to power plants. Since there were no data available about the washability and other characteristics of these jointly mined coals, new samples were prepared according to their production ratios and all the tests performed on individual samples were also applied to these joint samples. Also, for these samples the most suitable coal preparation systems (flowsheets) were designed and tested in the laboratory. The actual test results obtained with the use of eight different circuits for the six sets of jointly mined seams were compared with the individual test results. It was concluded that for optimum yield and maximum ash and sulfur removal, a physical washing system containing dense medium and Deister Table is the most suitable coal preparation method for Missouri coals.

  14. Resistive Networks.

    ERIC Educational Resources Information Center

    Balabanian, Norman

    This programed text on resistive networks was developed under contract with the United States Office of Education as part of a series of materials for use in an electrical engineering sequence. It is to be used in conjunction with other materials and with other short texts in the series, this one being Number 3. (DH)

  15. Automated concept and relationship extraction for the semi-automated ontology management (SEAM) system.

    PubMed

    Doing-Harris, Kristina; Livnat, Yarden; Meystre, Stephane

    2015-01-01

    We develop medical-specialty specific ontologies that contain the settled science and common term usage. We leverage current practices in information and relationship extraction to streamline the ontology development process. Our system combines different text types with information and relationship extraction techniques in a low overhead modifiable system. Our SEmi-Automated ontology Maintenance (SEAM) system features a natural language processing pipeline for information extraction. Synonym and hierarchical groups are identified using corpus-based semantics and lexico-syntactic patterns. The semantic vectors we use are term frequency by inverse document frequency and context vectors. Clinical documents contain the terms we want in an ontology. They also contain idiosyncratic usage and are unlikely to contain the linguistic constructs associated with synonym and hierarchy identification. By including both clinical and biomedical texts, SEAM can recommend terms from those appearing in both document types. The set of recommended terms is then used to filter the synonyms and hierarchical relationships extracted from the biomedical corpus. We demonstrate the generality of the system across three use cases: ontologies for acute changes in mental status, Medically Unexplained Syndromes, and echocardiogram summary statements. Across the three uses cases, we held the number of recommended terms relatively constant by changing SEAM's parameters. Experts seem to find more than 300 recommended terms to be overwhelming. The approval rate of recommended terms increased as the number and specificity of clinical documents in the corpus increased. It was 60% when there were 199 clinical documents that were not specific to the ontology domain and 90% when there were 2879 documents very specific to the target domain. We found that fewer than 100 recommended synonym groups were also preferred. Approval rates for synonym recommendations remained low varying from 43% to 25% as the

  16. Hybrid Technology of Hard Coal Mining from Seams Located at Great Depths

    NASA Astrophysics Data System (ADS)

    Czaja, Piotr; Kamiński, Paweł; Klich, Jerzy; Tajduś, Antoni

    2014-10-01

    Learning to control fire changed the life of man considerably. Learning to convert the energy derived from combustion of coal or hydrocarbons into another type of energy, such as steam pressure or electricity, has put him on the path of scientific and technological revolution, stimulating dynamic development. Since the dawn of time, fossil fuels have been serving as the mankind's natural reservoir of energy in an increasingly great capacity. A completely incomprehensible refusal to use fossil fuels causes some local populations, who do not possess a comprehensive knowledge of the subject, to protest and even generate social conflicts as an expression of their dislike for the extraction of minerals. Our times are marked by the search for more efficient ways of utilizing fossil fuels by introducing non-conventional technologies of exploiting conventional energy sources. During apartheid, South Africa demonstrated that cheap coal can easily satisfy total demand for liquid and gaseous fuels. In consideration of current high prices of hydrocarbon media (oil and gas), gasification or liquefaction of coal seems to be the innovative technology convergent with contemporary expectations of both energy producers as well as environmentalists. Known mainly from literature reports, underground coal gasification technologies can be brought down to two basic methods: - shaftless method - drilling, in which the gasified seam is uncovered using boreholes drilled from the surface, - shaft method, in which the existing infrastructure of underground mines is used to uncover the seams. This paper presents a hybrid shaft-drilling approach to the acquisition of primary energy carriers (methane and syngas) from coal seams located at great depths. A major advantage of this method is the fact that the use of conventional coal mining technology requires the seams located at great depths to be placed on the off-balance sheet, while the hybrid method of underground

  17. Numerical study on 4-1 coal seam of Xiaoming mine in ascending mining.

    PubMed

    Lan, Tianwei; Zhang, Hongwei; Li, Sheng; Han, Jun; Song, Weihua; Batugin, A C; Tang, Guoshui

    2015-01-01

    Coal seams ascending mining technology is very significant, since it influences the safety production and the liberation of dull coal, speeds up the construction of energy, improves the stability of stope, and reduces or avoids deep hard rock mining induced mine disaster. Combined with the Xiaoming ascending mining mine 4-1, by numerical calculation, the paper analyses ascending mining 4-1 factors, determines the feasibility of ascending mining 4-1 coalbed, and proposes roadway layout program about working face, which has broad economic and social benefits.

  18. Numerical Study on 4-1 Coal Seam of Xiaoming Mine in Ascending Mining

    PubMed Central

    Tianwei, Lan; Hongwei, Zhang; Sheng, Li; Weihua, Song; Batugin, A. C.; Guoshui, Tang

    2015-01-01

    Coal seams ascending mining technology is very significant, since it influences the safety production and the liberation of dull coal, speeds up the construction of energy, improves the stability of stope, and reduces or avoids deep hard rock mining induced mine disaster. Combined with the Xiaoming ascending mining mine 4-1, by numerical calculation, the paper analyses ascending mining 4-1 factors, determines the feasibility of ascending mining 4-1 coalbed, and proposes roadway layout program about working face, which has broad economic and social benefits. PMID:25866840

  19. The Influence of Laser Welding Processes on the Weld Seam Quality of Thermoplastic Composites with High Moisture Content

    NASA Astrophysics Data System (ADS)

    Wippo, V.; Winter, Y.; Jaeschke, P.; Suttmann, O.; Overmeyer, L.

    Presently, fiber reinforced materials are used for many industrial applications. Laser transmission welding (LTW) is a suitable method to join these materials. For multiple thermoplastics, the weld seam quality is affected by the amount of moisture content in the joining members. For LTW, heat is applied to the welding members and water in the composite changes phase from liquid to gas. Increasing the gas content can lead to detrimental cavities in the weld seam. Therefore, experiments were performed to investigate the influence of the laser focal geometry on the generation of cavities. Different focal geometries lead to different levels of process heat generation which affects the amount of vaporization. The experiments were conducted with endless glass fiber reinforced polyetherimide and endless carbon fiber reinforced polyetherimide. These samples were tested for their weld seam strength and the results were correlated to the moisture content and laser beam geometry.

  20. Kinematic effects on gait of a newly designed ankle-foot orthosis with oil damper resistance: a case series of 2 patients with hemiplegia.

    PubMed

    Yokoyama, Osamu; Sashika, Hironobu; Hagiwara, Akiyoshi; Yamamoto, Sumiko; Yasui, Tadashi

    2005-01-01

    The ankle joint of ankle-foot orthoses (AFOs) should restrict plantarflexion to prevent foot drop during the swing phase. However, excessive plantarflexion resistance causes excessive knee flexion during the stance phase. Plantarflexion resistive moment should be easily adjustable according to the gait ability of patients with hemiplegia. Because it is difficult to adjust plantarflexion resistive moment exactly, we developed an AFO with an oil damper. It is a small shock absorber that utilizes hydraulic resistance. The oil damper generates a resistive moment to the plantarflexion rotation of the ankle joint at the initial stance phase. The magnitude of the plantarflexion resistive moment at the heel strike can be easily adjusted to accommodate each patient's condition by simply turning an adjustment screw. We used a gait analysis system to compare the gait of 2 hemiplegic patients while they were wearing either the AFO with the oil damper or the AFO with the plantarflexion stop. The AFO with the oil damper achieved sufficient plantarflexion of the ankle and mild flexion of the knee by adjusting a proper plantarflexion resistive moment during initial stance phase, and provided a more comfortable gait than did the AFOs with a plantarflexion stop.

  1. Dynamic mapping of conical intersection seams: A general method for incorporating the geometric phase in adiabatic dynamics in polyatomic systems

    NASA Astrophysics Data System (ADS)

    Xie, Changjian; Malbon, Christopher L.; Yarkony, David R.; Guo, Hua

    2017-07-01

    The incorporation of the geometric phase in single-state adiabatic dynamics near a conical intersection (CI) seam has so far been restricted to molecular systems with high symmetry or simple model Hamiltonians. This is due to the fact that the ab initio determined derivative coupling (DC) in a multi-dimensional space is not curl-free, thus making its line integral path dependent. In a recent work [C. L. Malbon et al., J. Chem. Phys. 145, 234111 (2016)], we proposed a new and general approach based on an ab initio determined diabatic representation consisting of only two electronic states, in which the DC is completely removable, so that its line integral is path independent in the simply connected domains that exclude the CI seam. Then with the CIs included, the line integral of the single-valued DC can be used to construct the complex geometry-dependent phase needed to exactly eliminate the double-valued character of the real-valued adiabatic electronic wavefunction. This geometry-dependent phase gives rise to a vector potential which, when included in the adiabatic representation, rigorously accounts for the geometric phase in a system with an arbitrary locus of the CI seam and an arbitrary number of internal coordinates. In this work, we demonstrate this approach in a three-dimensional treatment of the tunneling facilitated dissociation of the S1 state of phenol, which is affected by a Cs symmetry allowed but otherwise accidental seam of CI. Here, since the space is three-dimensional rather than two-dimensional, the seam is a curve rather than a point. The nodal structure of the ground state vibronic wavefunction is shown to map out the seam of CI.

  2. The C. elegans engrailed homolog ceh-16 regulates the self-renewal expansion division of stem cell-like seam cells.

    PubMed

    Huang, Xinxin; Tian, E; Xu, Yanhua; Zhang, Hong

    2009-09-15

    Stem cells undergo symmetric and asymmetric division to maintain the dynamic equilibrium of the stem cell pool and also to generate a variety of differentiated cells. The homeostatic mechanism controlling the choice between self-renewal and differentiation of stem cells is poorly understood. We show here that ceh-16, encoding the C. elegans ortholog of the transcription factor Engrailed, controls symmetric and asymmetric division of stem cell-like seam cells. Loss of function of ceh-16 causes certain seam cells, which normally undergo symmetric self-renewal expansion division with both daughters adopting the seam cell fate, to divide asymmetrically with only one daughter retaining the seam cell fate. The human engrailed homolog En2 functionally substitutes the role of ceh-16 in promoting self-renewal expansion division of seam cells. Loss of function of apr-1, encoding the C. elegans homolog of the Wnt signaling component APC, results in transformation of self-renewal maintenance seam cell division to self-renewal expansion division, leading to seam cell hyperplasia. The apr-1 mutation suppresses the seam cell division defect in ceh-16 mutants. Our study reveals that ceh-16 interacts with the Wnt signaling pathway to control the choice between self-renewal expansion and maintenance division and also demonstrates an evolutionarily conserved function of engrailed in promoting cell proliferation.

  3. "Knitting Nannas" and "Frackman": A Gender Analysis of Australian Anti-Coal Seam Gas Documentaries (CSG) and Implications for Environmental Adult Education

    ERIC Educational Resources Information Center

    Larri, Larraine J.; Newlands, Maxine

    2017-01-01

    "Frackman" ("FM") and "Knitting Nannas" ("KN") are two documentaries about the anti-coal seam gas movement in Australia. "Frackman" features a former construction worker turned eco-activist, Dayne Pratzky (DP), fighting coal seam gas extraction. "Knitting Nannas" follows a group of women…

  4. "Knitting Nannas" and "Frackman": A Gender Analysis of Australian Anti-Coal Seam Gas Documentaries (CSG) and Implications for Environmental Adult Education

    ERIC Educational Resources Information Center

    Larri, Larraine J.; Newlands, Maxine

    2017-01-01

    "Frackman" ("FM") and "Knitting Nannas" ("KN") are two documentaries about the anti-coal seam gas movement in Australia. "Frackman" features a former construction worker turned eco-activist, Dayne Pratzky (DP), fighting coal seam gas extraction. "Knitting Nannas" follows a group of women…

  5. Petrographic and geochemical contrasts and environmentally significant trace elements in marine-influenced coal seams, Yanzhou mining area, China

    USGS Publications Warehouse

    Liu, Gaisheng; Yang, P.; Peng, Z.; Chou, C.-L.

    2004-01-01

    The Yanzhou mining area in west Shandong Province, China contains coals of Permian and Carboniferous age. The 31 and 32 seams of the Permian Shanxi Formation and seams 6, 15-17 of the Carboniferous Taiyuan Formation were analyzed for coal petrology, mineralogy and geochemical parameters. The parameters indicate that the coal is high volatile bituminous in rank. The coal is characterized by high vitrinite and low to medium inertinite and liptinite contents. These properties may be related to evolution of the coal forming environment from more reducing conditions in a marine influenced lower delta plain environment for the early Taiyuan coals to more oxidizing paleoenvironments in an upper delta plain for the upper Shanxi coal seams. The major mineral phases present in the coal are quartz, kaolinite, pyrite and calcite. Sulfur is one of the hazardous elements in coal. The major forms of sulfur in coal are pyritic, organic and sulfate sulfur. Pyritic and organic sulfur generally account for the bulk of the sulfur in coal. Elemental sulfur also occurs in coal, but only in trace to minor amounts. In this paper, the distribution and concentration of sulfur in the Yanzhou mining district are analyzed, and the forms of sulfur are studied. The sulfur content of the Taiyuan coal seams is considerably higher than that of the Shanxi coals. Organic sulfur content is positively correlated to total and pyritic sulfur. The vertical variation of Cu, Zn, Pb, As, Th, U and sulfur contents in coal seam 3 of the Shanxi Formation in the Xinglongzhuang mine show that all these trace elements, with the exception of Th, are enriched in the top and bottom plies of the seam, and that their concentrations are also relatively high in the dirt bands within the seam. The pyritic sulfur is positively correlated with total sulfur, and both are enriched in the top, bottom and parting plies of the seam. The concentrations of the trace elements are closely related to sulfur and ash contents. Most of

  6. Strong cation···π interactions promote the capture of metal ions within metal-seamed nanocapsule.

    PubMed

    Kumari, Harshita; Jin, Ping; Teat, Simon J; Barnes, Charles L; Dalgarno, Scott J; Atwood, Jerry L

    2014-12-10

    Thallium ions are transported to the interior of gallium-seamed pyrogallol[4]arene nanocapsules. In comparison to the capture of Cs ions, the extent of which depends on the type and position of the anion employed in the cesium salt, the enhanced strength of Tl···π vs Cs···π interactions facilitates permanent entrapment of Tl(+) ions on the capsule interior. "Stitching-up" the capsule seam with a tertiary metal (Zn, Rb, or K) affords new trimetallic nanocapsules in solid state.

  7. Access to new drugs and the global drug-resistant TB crisis: a case series from KwaZulu-Natal, South Africa.

    PubMed

    Master, I; Furin, J

    2016-07-01

    New drugs offer options for patients with drug-resistant tuberculosis (DR-TB). We describe four individuals with DR-TB in KwaZulu-Natal, South Africa, with prior exposure to clofazimine who would benefit from access to delamanid (DLM). Without DLM, individual options are limited, and there is a risk of resistance amplification and both community and nosocomial spread of DR-TB.

  8. Organic geochemical study of sequences overlying coal seams; example from the Mansfield Formation (Lower Pennsylvanian), Indiana

    USGS Publications Warehouse

    Mastalerz, Maria; Stankiewicz, A.B.; Salmon, G.; Kvale, E.P.; Millard, C.L.

    1997-01-01

    Roof successions above two coal seams from the Mansfield Formation (Lower Pennsylvanian) in the Indiana portion of the Illinois Basin have been studied with regard to sedimentary structures, organic petrology and organic geochemistry. The succession above the Blue Creek Member of the Mansfield Formation is typical of the lithologies covering low-sulphur coals ( 2.%). The transgressive-regressive packages above both seams reflect the periodic inundation of coastal mires by tidal flats and creeks as inferred from bioturbation and sedimentary structures such as tidal rhythmites and clay-draped ripple bedforms. Geochemistry and petrology of organic facies above the Blue Creek coal suggest that tidal flats formed inland in fresh-water environments. These overlying fresh water sediments prevented saline waters from invading the peat, contributing to low-sulphur content in the coal. Above the unnamed coal, trace fossils and geochemical and petrological characteristics of organic facies suggest more unrestricted seaward depositional environment. The absence of saline or typically marine biomarkers above this coal is interpreted as evidence of very short periods of marine transgression, as there was not enough time for establishment of the precursor organisms for marine biomarkers. However, sufficient time passed to raise SO42- concentration in pore waters, resulting in the formation of authigenic pyrite and sulphur incorporation into organic matter.

  9. Seam-based variable-step Bresenham blending method for real-time video mosaicking

    NASA Astrophysics Data System (ADS)

    Zhang, Hongru; Shi, Zaifeng; Pang, Ke; Cao, Qingjie; Luo, Tao; Yao, Suying

    2016-09-01

    Image blending plays an important role in video mosaicking, which has a high demand for real-time performance and visual quality. This paper proposes a fast blending method based on Bresenham algorithm, which realizes blending by controlling the storing addresses of source pixels. The starting storing location is accurately computed based on the coordinates of the middle pixel of the seam instead of the first pixel's, reducing the accumulated error along the seam significantly. The other storing addresses are acquired using a variable-step Bresenham method, which takes advantage of burst mode operation of a dynamic memory and can achieve a good trade-off between the operation convenience and memory requirement. By the proposed method, complicated calculations of storing addresses are simplified into integer additions and subtractions, which is more suitable for hardware implementation. A hardware architecture based on field programmable gate array is presented to evaluate the proposed method with clock frequency analysis and resource assessment. The experimental results show that the proposed method achieves good performance of high image quality, low computational complexity, and low memory requirement.

  10. Interpretation of Coal-Seam Sequestration Data Using a New Swelling and Shrinkage Model

    SciTech Connect

    Siriwardane, H.J.; Smith, D.H.

    2006-10-01

    This paper deals with the influence of swelling and shrinkage of coal on the production of methane from, and sequestration of carbon dioxide in, a coalbed reservoir. A three-dimensional swelling and shrinkage model was developed. It is based on constitutive equations that account for coupled fluid pressure-deformation behavior of a porous medium that undergoes swelling and shrinkage. The swelling and shrinkage strains are computed on the basis of the amounts of different gases (e.g., CO2, CH4) sorbed or desorbed. The amounts of sorption and desorption are computed from measured isotherms with the aid of the Ideal Adsorbed Solution model for mixed gases. The permeability of the reservoir is modified according to the swelling-shrinkage model. The paper presents numerical results for the influence of swelling and shrinkage on reservoir performance during injection of carbon dioxide. The paper includes results from a number of examples, and analysis of a field injection into a coal seam at a site in the San Juan basin. Results show that with the incorporation of swelling and shrinkage into the analysis, it is possible to get a better history-match of production data. Results also show that coal swelling can reduce the injection volumes of carbon dioxide significantly. The interpretation of field data with the new swelling-shrinkage model shows that the coal swelling during carbon dioxide sequestration in coal-seams is an important factor that can influence field performance.

  11. Recycling of coal seam gas-associated water using vacuum membrane distillation.

    PubMed

    Heidarpour, Farideh; Shi, Jeffrey; Chae, So-Ryong

    2015-01-01

    Coal seam gas-associated water (CSGAW), which is a by-product of coal seam gas (CSG) production typically contains significant amounts of salts and has potential environmental issues. In this study, we optimized a bench-scale vacuum membrane distillation (VMD) process with flat-sheet hydrophobic polytetrafluoroethylene (PTFE) membranes for the treatment of synthetic CSGAW (conductivity = 15 mS/cm). To study performance of the VMD process, we explored the effects of feed temperature (T(f) = 60, 70, and 80°C), feed flow rate (V(f) = 60, 120, and 240 mL/min), and vacuum pressure (P(v) = 3, 6, and 9 kPa) on water permeability through the PTFE membrane in the VMD process. Under the optimum conditions (i.e. T(f) = 80°C, V(f) = 240 mL/min, P(v) = 3 kPa), water permeability and rejection efficiency of salts by the VMD process were found to be 5.5 L/m(2)/h (LMH) and 99.9%, respectively, after 2 h filtration. However, after 8 h operation, the water permeability decreased by 70% compared with the initial flux due to the formation of fouling layer of calcium, chloride, sodium, magnesium, and potassium on the membrane surface.

  12. A case study of multi-seam coal mine entry stability analysis with strength reduction method

    PubMed Central

    Tulu, Ihsan Berk; Esterhuizen, Gabriel S; Klemetti, Ted; Murphy, Michael M.; Sumner, James; Sloan, Michael

    2017-01-01

    In this paper, the advantage of using numerical models with the strength reduction method (SRM) to evaluate entry stability in complex multiple-seam conditions is demonstrated. A coal mine under variable topography from the Central Appalachian region is used as a case study. At this mine, unexpected roof conditions were encountered during development below previously mined panels. Stress mapping and observation of ground conditions were used to quantify the success of entry support systems in three room-and-pillar panels. Numerical model analyses were initially conducted to estimate the stresses induced by the multiple-seam mining at the locations of the affected entries. The SRM was used to quantify the stability factor of the supported roof of the entries at selected locations. The SRM-calculated stability factors were compared with observations made during the site visits, and the results demonstrate that the SRM adequately identifies the unexpected roof conditions in this complex case. It is concluded that the SRM can be used to effectively evaluate the likely success of roof supports and the stability condition of entries in coal mines. PMID:28239503

  13. Managing produced water from coal seam gas projects: implications for an emerging industry in Australia.

    PubMed

    Davies, Peter J; Gore, Damian B; Khan, Stuart J

    2015-07-01

    This paper reviews the environmental problems, impacts and risks associated with the generation and disposal of produced water by the emerging coal seam gas (CSG) industry and how it may be relevant to Australia and similar physical settings. With only limited independent research on the potential environmental impacts of produced water, is it necessary for industry and government policy makers and regulators to draw upon the experiences of related endeavours such as mining and groundwater extraction accepting that the conclusions may not always be directly transferrable. CSG is widely touted in Australia as having the potential to provide significant economic and energy security benefits, yet the environmental and health policies and the planning and regulatory setting are yet to mature and are continuing to evolve amidst ongoing social and environmental concerns and political indecision. In this review, produced water has been defined as water that is brought to the land surface during the process of recovering methane gas from coal seams and includes water sourced from CSG wells as well as flowback water associated with drilling, hydraulic fracturing and gas extraction. A brief overview of produced water generation, its characteristics and environmental issues is provided. A review of past lessons and identification of potential risks, including disposal options, is included to assist in planning and management of this industry.

  14. Structure instability forecasting and analysis of giant rock pillars in steeply dipping thick coal seams

    NASA Astrophysics Data System (ADS)

    Lai, Xing-ping; Sun, Huan; Shan, Peng-fei; Cai, Ming; Cao, Jian-tao; Cui, Feng

    2015-12-01

    Structure stability analysis of rock masses is essential for forecasting catastrophic structure failure in coal seam mining. Steeply dipping thick coal seams (SDTCS) are common in the Urumqi coalfield, and some dynamical hazards such as roof collapse and mining- induced seismicity occur frequently in the coal mines. The cause of these events is mainly structure instability in giant rock pillars sandwiched between SDTCS. Developing methods to predict these events is important for safe mining in such a complex environment. This study focuses on understanding the structural mechanics model of a giant rock pillar and presents a viewpoint of the stability of a trend sphenoid fractured beam (TSFB). Some stability index parameters such as failure surface dips were measured, and most dips were observed to be between 46° and 51°. We used a digital panoramic borehole monitoring system to measure the TSFB's height (Δ H), which varied from 56.37 to 60.50 m. Next, FLAC3D was used to model the distribution and evolution of vertical displacement in the giant rock pillars; the results confirmed the existence of a TSFB structure. Finally, we investigated the acoustic emission (AE) energy accumulation rate and observed that the rate commonly ranged from 20 to 40 kJ/min. The AE energy accumulation rate could be used to anticipate impeding seismic events related to structure failure. The results presented provide a useful approach for forecasting catastrophic events related to structure instability and for developing hazard prevention technology for mining in SDTCS.

  15. Using vector building maps to aid in generating seams for low-attitude aerial orthoimage mosaicking: Advantages in avoiding the crossing of buildings

    NASA Astrophysics Data System (ADS)

    Wang, Dongliang; Cao, Wei; Xin, Xiaoping; Shao, Quanqin; Brolly, Matthew; Xiao, Jianhua; Wan, Youchuan; Zhang, Yongjun

    2017-03-01

    A novel seam detection approach based on vector building maps is presented for low-attitude aerial orthoimage mosaicking. The approach tracks the centerlines between vector buildings to generate the candidate seams that avoid crossing buildings existing in maps. The candidate seams are then refined by considering their surrounding pixels to minimize the visual transition between the images to be mosaicked. After the refinement of the candidate seams, the final seams further bypass most of the buildings that are not updated into vector maps. Finally, three groups of aerial imagery from different urban densities are employed to test the proposed approach. The experimental results illustrate the advantages of the proposed approach in avoiding the crossing of buildings. The computational efficiency of the proposed approach is also significantly higher than that of Dijkstra's algorithm.

  16. Data base for the analysis of compositional characteristics of coal seams and macerals. Part 7. Petrographic variation due to depositional setting of the lower Kittanning seam, western Pennsylvania. Final report

    SciTech Connect

    Allshouse, S.D.; Davis, A.

    1984-01-01

    Detailed megascopic and microscopic petrographic analyses were conducted on samples of the Lower Kittanning seam from western Pennsylvania. Relationships were sought between the paleoenvironmental setting of the coal swamp and the vertical and lateral variability of lithotypes, maceral composition and vitrinite types. Megascopically, the four samples collected from the freshwater facies of the seam are similar in appearance and relative lithotype composition, and display no distinct vertical zonations. The sample from the marine-influenced central portion of the basin (PSOC-1340) possesses a marked vertical zonation into a bright lower zone and a dull upper zone. The lower zone is similar in appearance to the freswater samples. Detailed microscopic analyses revealed that the vertical zonation of PSOC-1340 is apparent in both the maceral and vitrinite type composition. No similar zonation is apparent in the microscopic analysis of the four freshwater facies samples. Similarities between the lower zone of PSOC-1340 and the whole seam of the freshwater samples are most apparent in the vitrinite-type analysis. The lower zone of PSOC-1340 and the whole seam from the freshwater facies are considered to be laterally equivalent coal types. The dull upper zone of PSOC-1340 is considered to have formed in response to a major change in the paleoenvironment of the swamp, probably a marine transgression. 49 references, 25 figures, 15 tables.

  17. Data base for analysis of compositional characteristics of coal seams and macerals. Quarterly technical progress report, November-January 1981

    SciTech Connect

    Davis, A; Suhr, N H; Spackman, W; Painter, P C; Walker, P L; Given, P H

    1981-04-01

    The basic objectives of this program are, first, to understand the systematic relationships between the properties of coals, and, second, to determine the nature of the lateral and vertical variability in the properties of a single seam. Multivariate statistical analyses applied to the Coal Data Base confirm a number of known trends for coal properties. In addition, nitrogen and some components of the ash analysis bear interesting relationships to rank. The macroscopic petrography of column samples of the Lower Kittanning seam reveals a significant difference between the sample from a marine-influenced environment and those from toward the margins of the basin where conditions were non-marine. The various methods of determining the amount and mineralogy of the inorganic fraction of coals are reviewed. General trends in seam thickness, ash, sulfur, volatile matter yield, and vitrinite reflectance of the Lower Kittanning seam of western Pennsylvania are presented. Controls of sedimentation are discussed in relation to the areal variability which has been observed. Differential subsidence and paleotopography appear to have played a major role during the deposition of the coal. The same controls may have maintained some influence upon the coalification process after deposition, especially along the eastern margin of the Lower Kittanning basin.

  18. Geochemistry of autochthonous and hypautochthonous siderite-dolomite coal-balls (Foord Seam, Bolsovian, Upper Carboniferous), Nova Scotia, Canada

    USGS Publications Warehouse

    Zodrow, E.L.; Lyons, P.C.; Millay, M.A.

    1996-01-01

    The 11-13 m thick Foord Seam in the fault-bounded Stellarton Basin, Nova Scotia, is the thickest seam from the Euramerican floral province known to contain coal-balls. In addition to the first discovery of autochthonous coal-balls in the Foord Seam, Nova Scotia, its shale parting also contains hypautochthonous coal-balls with histologically preserved plant structures. The coal-ball discovery helps fill a stratigraphic gap in coal-ball occurrences in the upper Carboniferous (Bolsovian) of Euramerica. The autochthonous and hypautochthonous coal-balls have a similar mineralogical composition and are composed of siderite (81-100%), dolomite-ankerite (0-19%), minor quartz and illite, and trace amounts of 'calcite'. Similar is also their permineralizing mineralogy, which consists of dolomite-ankerite and siderite. Their low pyrite content and carbonate mineralogy, and nonmarine origin, differentiates the Foord Seam coal-balls from other Euramerican coal-ball occurrences. A preliminary geochemical model, which is based on oxygen and carbon isotopic data, indicates that siderite in both the autochthonous and hypautochthonous coal-balls is of very early diagenetic (nonmarine) origin from 13C-enriched bicarbonate derived from bacterial methanogenesis of organic matter.

  19. The Influence of a Local Fault Zone on High Energy Tremor Occurrence During Longwall Mining of a Coal Seam

    NASA Astrophysics Data System (ADS)

    Wojtecki, Łukasz; Knopik, Małgorzata; Zuberek, Wacław Marian

    2016-08-01

    Underground mining of coal seams in the Upper Silesian Coal Basin in Poland is accompanied by seismic activity of varying magnitude. The investigations which have been performed for several years distinguished high energy mine tremors connected directly with mining or coupled with geological structures, such as large faults. In mined seams, local fault zones occur. Faults in these zones are usually small, with throws comparable with coal seams thicknesses. Local fault zone may be responsible for the occurrence of high energy tremors as well as large faults, as presented in this article. An analysis of source mechanism of high energy tremors generated during longwall mining of the coal seam No. 510, with presence of a local fault zone, in one of the Polish hard coal mines in the Upper Silesian Coal Basin was performed. For this purpose, the seismic moment tensor inversion method was used. In most of foci, the process of shear predominated. Determined nodal plane parameters were correlated with parameters of faults forming the local fault zone. High energy tremors were generated mostly by dislocations on faults of the local fault zone. Weakening of roof rocks in the neighborhood of local fault zone takes an important role too, and was responsible for share of implosion in the focal mechanism.

  20. Quaternary subrosion and transformation of Stassfurt potash seam (Zechstein 2) at top of Gorleben salt dome, Federal Republic of Germany

    SciTech Connect

    Bornemann, O.; Fischbeck, R.

    1989-03-01

    The Gorleben salt dome is located in the eastern part of Lower Saxony in northern Germany. The dome consists of salt layers of cycles 2, 3, and 4 (z2-z4) of the Zechstein. Above-ground studies have been conducted since 1979 to determine whether the Gorleben salt dome is suited for the permanent disposal of radioactive waste. During the Elster glacial stage, the Gorleben salt dome was covered by up to 1000 m-thick ice. The meltwater eroded up to 300-m deep runoff channels into the rock beneath the glacier. One of these Quaternary channels runs across the salt dome; locally, the channel cuts the cap rock down to the rock salt. The Stassfurt potash seam cuts across at the bottom of this channel under Quaternary sediments. Between 90 and 170 m below the top of the salt dome, the potash seam was encountered in different stages of transformation. The sequence from bottom to top was as follows: unchanged carnallitic rock, followed by a zone of kainitic rock, ending with a potash-free halitic rock containing clastic material from the overlying sediments. Diagenesis of the clastic Elsterian sediments interbedded in the rock salt blocked further migration of solutions into the potash seam. No evidence has been found for further subrosion of the potash seam since the Elsterian (i.e., the last 300,000 years).

  1. Finite element modeling of magnetoacoustic emission and of stress-induced magnetic effects at seam welds in steel pipes

    SciTech Connect

    Sablik, M. J.; Weidner, C.; Augustyniak, B.

    2001-06-01

    Prior finite element modeling (FEM) has shown how creep damage reduces the voltage signal in a secondary coil wrapped around a C-core electromagnet positioned above a seam weld in a steel pipe. Prior hysteresis modeling has also demonstrated the reduction of magnetoacoustic emission (MAE) due to uniform creep damage in a steel specimen. In this article, it is shown how to evaluate the MAE due to a nonuniform distribution of creep damage at a seam weld using FEM. Also, FEM is used to evaluate the C-core secondary emf due to a nonuniform stress distribution, which is developed at a seam weld due to the internal pressure of hot steam passing through the pipe. In this latter case, use is made of the stress distribution computed at the seam weld by Stevick. It is found that nonuniform creep damage also reduces the MAE signal, as is found experimentally. The stresses due to internal pressure in the pipe are shown by FEM to increase the C-core secondary emf, which is opposite to the effect of creep damage. A comparison is made between stressed and unstressed cases, with and without creep damage. {copyright} 2001 American Institute of Physics.

  2. The Human Side of School Change: Reform, Resistance, and the Real-Life Problems of Innovation. The Jossey-Bass Education Series.

    ERIC Educational Resources Information Center

    Evans, Robert

    The human side of school reform and the difficulties of implementing innovation are examined in this book. The book suggests that one of the main reason efforts to reform schools stall is that educators resist change because they feel burdened or conflicted by the process. The book, therefore, focuses on realistic expectations concerning the pace…

  3. Concomitant use of radiotherapy and two topoisomerase inhibitors to treat adult T-cell leukemia with a radiotherapy-resistant bulky disease: a case series.

    PubMed

    Obama, Kosuke

    2014-01-01

    Concomitant chemoradiotherapy is established as the standard treatment to improve the prognosis of several types of solid tumor, but has not been the general practice for hematological malignancies. Here, I report two cases of adult T-cell leukemia (ATL) with a radiotherapy-resistant bulky disease treated with concomitant radiotherapy and two topoisomerase inhibitors: etoposide (VP-16) and irinotecan (CPT-11). Patient 1 was a 78-year-old man with chemotherapy-resistant inguinal bulky mass. Radiotherapy (total 40 Gy) for this inguinal lesion was started; however, the bulky disease was found to be resistant to radiotherapy and progressed. VP-16 and CPT-11 were administered in addition to radiotherapy (after a total of 20 Gy of radiotherapy). Patient 2 was a 71-year-old man with a solitary bulky mass in left cervical lesion. Various previous chemotherapy and radiotherapy approaches had not been able to control the disease. Six months after first radiotherapy, the bulky disease rapidly progressed with the occurrence of pain. Second radiotherapy (30 Gy) was started with simultaneous administration of CPT-11 and VP-16. In both cases, the bulky disease gradually regressed and completely disappeared by the end of radiotherapy. Thus, flexible adaptation of concomitant chemoradiotherapy including two topoisomerase inhibitors may offer a potential therapeutic option for radiotherapy-resistant bulky diseases, even in hematological malignancies.

  4. Electrical Resistivity Tomography for coal fire mapping over Jharia coal field, India

    NASA Astrophysics Data System (ADS)

    Pal, S. K.; Kumar, S.; Bharti, A. K.; Pathak, V. K.; Kumar, R.

    2016-12-01

    Over the decades, coal fires are serious global concern posing grievous hazards to the valuable energy resources, local environments and human life. The coal seam and coal mine fires may be initiated due to improper mining activities, exothermic reactions, lighting, forest fire and other anthropic activities, which burn the coal and may continue underground for decades. The burning of concealed coal seams is a complex process involving numerous ill-defined parameters. Generally, the coal exhibits resistivity of 100 to 500Ωm at normal temperature conditions. During the pyrolysis process, at temperatures greater than 6500C coal became a good conductor with a resistivity of approximately 1 Ωm. The present study deals with the mapping of coal fire over Jharia coal field, India using Electrical Resistivity Tomography (ERT). A state-of-the-art 61-channel 64 electrode FlashRES-Universal ERT data acquisition system has been used for data acquisition in the field. The ERT data have been collected using Gradient array and processed in FlashRES Universal survey data checking program for removing noisy data. Then, filtered output data have been inverted using a 2.5D resistivity inversion program. Low resistivity anomalies over 80m-125m and 320m-390m along the profile are inferred to be active coal fire in seam- XVI at a depth of 25m -35m(Figure 1). High resistivity anomaly over 445m - 510m at a depth of 25m -35m has been delineated, due to void associated with complete combustion of seam- XVI coal, followed by char and ash formation resulting from the coal seam fire. Results prove the efficacy of the ERT study comprising Gradient array for coal fire mapping over, Jharia coal field, India.

  5. Small-scale explosive seam welding. [using ribbon explosive encased in lead sheath

    NASA Technical Reports Server (NTRS)

    Bement, L. J.

    1972-01-01

    A unique small scale explosive seam welding technique is reported that has successfully joined a variety of aluminum alloys and alloy combinations in thicknesses to 0.125 inch, as well as titanium in thicknesses to 0.056 inch. The explosively welded joints are less than one-half inch in width and apparently have no long length limitation. The ribbon explosive developed in this study contains very small quantities of explosive encased in a flexible thin lead sheath. The evaluation and demonstration of this welding technique was accomplished in three phases: evaluation and optimization of ten major explosive welding variables, the development of four weld joints, and an applicational analysis which included photomicrographs, pressure integrity tests, vacuum effects, and fabrication of some potentially useful structures in aluminum and titanium.

  6. Multifrequency eddy-current inspection of seam weld in steel sheath

    SciTech Connect

    Smith, J.H.; Dodd, C.V.; Chitwood, L.D.

    1985-04-01

    Multifrequency eddy-current techniques were used to perform a continuous on-line inspection of the seam weld in the steel jacket for a superconducting cable. The inspection was required to detect both surface and internal weld flaws in the presence of a large, highly conductive central conductor. Raw eddy-current data were recorded on magnetic tape, and test properties such as discontinuity size and weld penetration were determined by mathematically fitting these data to coefficients developed with representative standards. A sophisticated computer-controlled scanning technique was applied, and a unique scanning device was developed to provide full coverage of the weld and heat-affected zone. The techniques used to develop this multifrequency eddy-current examination are described in this report along with the test equipment, test procedures, and computer programs.

  7. Coal seam gas water: potential hazards and exposure pathways in Queensland.

    PubMed

    Navi, Maryam; Skelly, Chris; Taulis, Mauricio; Nasiri, Shahram

    2015-01-01

    The extraction of coal seam gas (CSG) produces large volumes of potentially contaminated water. It has raised concerns about the environmental health impacts of the co-produced CSG water. In this paper, we review CSG water contaminants and their potential health effects in the context of exposure pathways in Queensland's CSG basins. The hazardous substances associated with CSG water in Queensland include fluoride, boron, lead and benzene. The exposure pathways for CSG water are (1) water used for municipal purposes; (2) recreational water activities in rivers; (3) occupational exposures; (4) water extracted from contaminated aquifers; and (5) indirect exposure through the food chain. We recommend mapping of exposure pathways into communities in CSG regions to determine the potentially exposed populations in Queensland. Future efforts to monitor chemicals of concern and consolidate them into a central database will build the necessary capability to undertake a much needed environmental health impact assessment.

  8. Teleoperated continuous miner for thin-seam applications. Information circular/1994

    SciTech Connect

    Monaghan, W.D.; Kwitowski, A.J.; Brautigam, A.L.; Mayercheck, W.D.

    1993-09-29

    The U.S. Bureau of Mines evaluated a teleoperated continuous mining machine for deep mining in thin-seam applications as low as 1 m. Teleoperation increases the safety of mining machine operators because it removes the operator from the face, an area of immediate hazards, to safer locations. By using teleoperation, the miner can avoid many hazards, including unexpected roof falls that can maim or kill miners instantly, methane and coal dust explosions that can be ignited with just a small spark or flame, adverse long-term health effects from miners breathing coal and silica dust, long-term inner ear damage from loud noise pollution, and other hazards related to heavy mining equipment moving about in confined unerground roadways. The report presents the surface evaluation results of a teleoperated control system.

  9. Estimtion of the Energy Release of Coal Seam Fires and its Relevance for CDM

    NASA Astrophysics Data System (ADS)

    Rueter, Horst; Meyer, Uwe; Chen-Brauchler, Dai

    2010-05-01

    Spontaneous coal seam fires contribute significant to the CO2 emissions world wide. As the coal fires are complicated regarding structure and dynamics it is not trivial to fins out how much CO2 is released by an individual fire. This value is basic also for a possible certificate trading in connection with the extinction of those fires in the context of CDM. Three basic methods were proposed to estimate the amount of CO2 emitted. 1. Direct gas measurements (direct approach) 2. Estimation of the coal burned (volume approach) 3. Energy releases (energy approach) The energy approach turned out to be the only practical solution. The energy balance of the fire is a composition of the components 1. Radiation 2. Energy release from subsurface to air 3. Energy transported by hot exhaust gases 4. Energy transported by matrix diffusion Those components are explained and a field case from a fire zone in China is presented.

  10. Significance of the Resonance Condition for Controlling the Seam Position in Laser-assisted TIG Welding

    NASA Astrophysics Data System (ADS)

    Emde, B.; Huse, M.; Hermsdorf, J.; Kaierle, S.; Wesling, V.; Overmeyer, L.; Kozakov, R.; Uhrlandt, D.

    As an energy-preserving variant of laser hybrid welding, laser-assisted arc welding uses laser powers of less than 1 kW. Recent studies have shown that the electrical conductivity of a TIG welding arc changes within the arc in case of a resonant interaction between laser radiation and argon atoms. This paper presents investigations on how to control the position of the arc root on the workpiece by means of the resonant interaction. Furthermore, the influence on the welding result is demonstrated. The welding tests were carried out on a cooled copper plate and steel samples with resonant and non-resonant laser radiation. Moreover, an analysis of the weld seam is presented.

  11. Robotic complex for the development of thick steeply-inclined coal seams and ore deposits

    NASA Astrophysics Data System (ADS)

    Nikitenko, M. S.; Malakhov, Yu V.; Neogi, Biswarup; Chakraborty, Pritam; Banerjee, Dipesu

    2017-09-01

    Proposal for the formulation of robotic complexes for steeply inclined coal seams as a basis of the supportive-enclosing walking module and power support with a controlled outlet for mining industry has been represented in this literature. In mining industry, the available resource base reserves and mineral deposits are concentrated deep down the earth crust leading towards a complicated geological condition i.e. abrupt ore bedding and steeply inclined strata with the high gas content and fire hazard of thick coal stratum, heading against an unfavorable and sometimes human labor life risk during subversive mining. Prevailing towards the development of effective robotic complexes based on the means of “unmanned technologies” for extraction of minerals from hard-to-reach deposits and make sure the safety of underground staff during sublevel mining technology.

  12. The mechanics of echelon vein and solution seam formation in limestone: examples from the eastern Monument Upwarp, UT

    NASA Astrophysics Data System (ADS)

    Seyum, S.; Pollard, D. D.

    2013-12-01

    Two sets of bed-perpendicular, echelon vein arrays with complementary echelon pressure solution seams are observed in Pennsylvanian to Permian limestone strata across Raplee anticline and the neighboring portion of Comb monocline, Utah. The array sets sometimes appear as conjugate pairs. We demonstrate, using a 2D mechanical model, how the physical attributes of complementary model cracks and seams in an array influence the relative displacements of crack surfaces to form shapes similar to veins observed in the field. Using dimensional analysis we identify the five dimensionless variables necessary to represent this physical model and quantify their effect on the heterogeneous displacement and stress fields. Those five variables are coordinate position, crack spacing (s), crack-array angle (α), array-remote stress angle (γ), and model seam shortening (Δu). We use the commercial finite element software Abaqus to model arrays of cracks and shortening seams in a model limestone having material properties determined from experimental rock mechanics literature (E = 60 GPa; ν = 0.25). Ranges of geometric values for model cracks come from field measurements of veins (half-lengths, apertures, spacing, vein-array angles, angle between conjugate array pairs). Remote boundary conditions (σ1∞ = 65MPa; σ3∞ = 10MPa) and crack boundary conditions (P = 30MPa) are within the range of tectonic conditions inferred from field relationships and the published burial history profile of the stratigraphy. The boundary conditions allow the model cracks to open for all geometric configurations explored here. Magnitudes of model seam shortening are supported by calculations of pressure solution seam shortening from petrographic analyses of rock samples. We compare model crack surface displacements with vein shapes, and analyze crack tip stresses to predict propagation direction. Veins in the field have triangular shapes and have straight traces when viewed perpendicular to bedding

  13. Lower electrical membrane potential and altered pHi homeostasis in multidrug-resistant (MDR) cells: further characterization of a series of MDR cell lines expressing different levels of P-glycoprotein.

    PubMed

    Roepe, P D; Wei, L Y; Cruz, J; Carlson, D

    1993-10-19

    Recently [Roepe, P.D. (1992) Biochemistry 31, 12555-12564], increased steady-state levels of chemotherapeutic drug efflux from multidrug-resistant (MDR) myeloma cells were correlated with intracellular alkalinization. To better understand elevated pHi in MDR cells, Na(+)- and Cl-dependent recovery of pHi upon intracellular acid or alkaline shock has been examined for this same series of MDR cell lines. In agreement with another recent report [Boscoboinik, D., Gupta, R.S., & Epand, R.M. (1990) Br. J. Cancer 61, 568-572], we find that the rate of Na(+)-induced alkalinization after an intracellular acid shock is increased in the MDR cells, relative to the drug-sensitive parent. Interestingly, we also now find that mRNA encoding the human Na+/H+ exchanger (NHE) is overexpressed in these MDR cells, but the level of overexpression does not correlate with the relative drug resistance or steady-state pHi. It is also found that the efficiency of Cl(-)dependent reacidification of pHi, after an intracellular alkaline shock is reduced in the MDR cells. This effect appears to correlate with the relative expression of MDR protein, but not the relative expression of Cl-/HCO3- exchanger (AE), which we now find is also altered in the series of cells. Since elevated pHi will increase delta pH across the plasma membrane, we have also measured the electrical potential for these cells using three different methods. Most interestingly, the magnitude of the plasma membrane electrical potential (delta psi) decreases concomitant with increased expression of the MDR protein. Energy provided by increased delta pH compensates for the lowered delta psi, such that the total electrochemical membrane potential (delta mu H+) remains similar among the cells in this series (delta mu H+ = delta psi - Z delta pH). These data, along with other recent experiments that associated an increased Cl- conductance with the expression of MDR protein [Valverde, M., Diaz, M., Sepúlveda, F.V., Gill, D.R., Hyde, S

  14. Assiniboine Series.

    ERIC Educational Resources Information Center

    Allen, Minerva

    This series of illustrated booklets presents 13 Indian stories in a bilingual format of English and Assiniboine, an Indian tribal language. Written on the first grade level, the stories have the following titles: (1) "Orange Tree in Lodgepole"; (2) "Pretty Flower"; (3) Inktomi and the Rock"; (4) "Inktomi and the…

  15. Assiniboine Series.

    ERIC Educational Resources Information Center

    Allen, Minerva

    This series of illustrated booklets presents 13 Indian stories in a bilingual format of English and Assiniboine, an Indian tribal language. Written on the first grade level, the stories have the following titles: (1) "Orange Tree in Lodgepole"; (2) "Pretty Flower"; (3) Inktomi and the Rock"; (4) "Inktomi and the…

  16. SERI laser scanner system

    SciTech Connect

    Matson, R.J.; Cannon, T.W.

    1980-10-01

    A Laser Scanner System (LSS) produces a photoresponse map and can be used for the nondestructive detection of nonuniformities in the photoresponse of a semiconductor device. At SERI the photoresponse maps are used to identify solar cell faults including microcracks, metallization breaks, regions of poor contact between metallization and the underlying emitter surface, and variations in emitter sheet resistance. The SERI LSS is patterned after the LSS unit documented in the NBS Special Publication 400-24 A Laser Scanner for Semiconductor Devices by D.E. Sawyer and D.W. Berning. Assuming reader familiarity with the above publication, the modifications introduced by SERI are specified with the intention that the two reports can be used to reproduce the SERI LSS. The optical and electronic systems are reviewed, briefly discussing the significant items of each. The most notable difference between the two systems is the SERI substitution of commercially available state-of-the-art modular electronics for the discreet component circuitry used in the NBS LSS.

  17. Study results on geotechnological processes of mining flat thick coal seams with top-coal drawing in face 21-1-5 of “Olzherasskaya” mine

    NASA Astrophysics Data System (ADS)

    Senkus, V. V.; Ermakov, A. Yu

    2016-10-01

    In the paper the modes of hydraulic props of powered support are considered; the regularities of their loading are established that allows the powered support for thick flat seams mining with top-coal drawing to be chosen.

  18. Earthquake resistant construction of gas and liquid fuel pipeline systems serving, or regulated by, the Federal government. Earthquake hazard reduction series No. 67

    SciTech Connect

    Yokel, F.Y.; Mathey, R.G.

    1992-07-01

    The vulnerability of gas and liquid fuel pipeline systems to damage in past earthquakes, as well as available standards and technologies that can protect these facilities against earthquake damage are reviewed. An overview is presented of measures taken by various Federal Agencies to protect pipeline systems under their jurisdiction against earthquake hazards. It is concluded that the overall performance of pipeline systems in past earthquakes was relatively good, however, older pipelines and above-ground storage tanks were damaged in many earthquakes. Standards and regulations for liquid fuel pipelines contain only general references to seismic loads. Standards and regulations for above-ground fuel storage tanks and for liquefied natural gas facilities contain explicit seismic design provisions. It is recommended that a guideline for earthquake resistant design of gas and liquid fuel pipeline systems be prepared for Federal Agencies to ensure a uniform approach to the protection of these systems.

  19. Demonstration of Three Corrosion-Resistant Sustainable Roofing Systems

    DTIC Science & Technology

    2013-06-01

    sloped- roof conversion using standing-seam metal roofing system with heat-shedding coating, and (3) a fiber - glass -reinforced plastic (FRP) panel...the location to demonstrate (1) a heat-resistant metal shingle roofing sys- tem with above-sheathing ventilation (ASV), (2) a sloped- roof conversion...51 Appendix A: Roof Design Drawings for Buildings 8-3846 and 3-2631 (Stone- Coated Shingle System

  20. Factors involved in evaluating ground water impacts of deep coal mine drainage. [Pumping tests of wells drilled into the coal seam and development of mathematical models; detailed discussion

    SciTech Connect

    Davis, P.R.; Walton, W.C.

    1982-10-01

    The determination of probable ground water impacts of proposed deep coal mining is required as part of permit applications. Impact prediction generally involves well production test analysis and modeling of ground water systems associated with coal seams. Well production tests are often complicated due to the relatively low permeabilities of sandstones and shales of ground water systems. The effects of the release of water stored within finite diameter production wells must be considered. Well storage capacity appreciably affects early well production test time drawdown or time recovery data. Low pumping rates, limited cones of depression, and length of required pumping periods are important well production test design factors. Coal seam ground water system models are usually multilayered and leaky artesian. Mine shafts partially penetrate the ground water system. Simulation of coal mine drainage often involves the horizontal permeability and storage coefficient of the coal seam zone, vertical permeablities of sandstones and shales (aquifer) above and below the coal seam zone, and the hydrologic properties of the source bed above the aquifer overlying the coal seam zone. Ground water level declines in both the coal seam zone and source bed near land surface are necessary factors in impact analysis. An example of evaluation studies in southwest Indiana will illustrate factors involved in deep coal mine drainage modeling efforts.

  1. The Caenorhabditis elegans GATA factor ELT-1 works through the cell proliferation regulator BRO-1 and the Fusogen EFF-1 to maintain the seam stem-like fate.

    PubMed

    Brabin, Charles; Appleford, Peter J; Woollard, Alison

    2011-08-01

    Seam cells in Caenorhabditis elegans provide a paradigm for the stem cell mode of division, with the ability to both self-renew and produce daughters that differentiate. The transcription factor RNT-1 and its DNA binding partner BRO-1 (homologues of the mammalian cancer-associated stem cell regulators RUNX and CBFβ, respectively) are known rate-limiting regulators of seam cell proliferation. Here, we show, using a combination of comparative genomics and DNA binding assays, that bro-1 expression is directly regulated by the GATA factor ELT-1. elt-1(RNAi) animals display similar seam cell lineage defects to bro-1 mutants, but have an additional phenotype in which seam cells lose their stem cell-like properties and differentiate inappropriately by fusing with the hyp7 epidermal syncytium. This phenotype is dependent on the fusogen EFF-1, which we show is repressed by ELT-1 in seam cells. Overall, our data suggest that ELT-1 has dual roles in the stem-like seam cells, acting both to promote proliferation and prevent differentiation.

  2. The Caenorhabditis elegans GATA Factor ELT-1 Works through the Cell Proliferation Regulator BRO-1 and the Fusogen EFF-1 to Maintain the Seam Stem-Like Fate

    PubMed Central

    Brabin, Charles; Appleford, Peter J.; Woollard, Alison

    2011-01-01

    Seam cells in Caenorhabditis elegans provide a paradigm for the stem cell mode of division, with the ability to both self-renew and produce daughters that differentiate. The transcription factor RNT-1 and its DNA binding partner BRO-1 (homologues of the mammalian cancer-associated stem cell regulators RUNX and CBFβ, respectively) are known rate-limiting regulators of seam cell proliferation. Here, we show, using a combination of comparative genomics and DNA binding assays, that bro-1 expression is directly regulated by the GATA factor ELT-1. elt-1(RNAi) animals display similar seam cell lineage defects to bro-1 mutants, but have an additional phenotype in which seam cells lose their stem cell-like properties and differentiate inappropriately by fusing with the hyp7 epidermal syncytium. This phenotype is dependent on the fusogen EFF-1, which we show is repressed by ELT-1 in seam cells. Overall, our data suggest that ELT-1 has dual roles in the stem-like seam cells, acting both to promote proliferation and prevent differentiation. PMID:21829390

  3. Exploring the sloped-to-peaked S2/S1 seam of intersection of thymine with electronic structure and direct quantum dynamics calculations.

    PubMed

    Asturiol, David; Lasorne, Benjamin; Worth, Graham A; Robb, Michael A; Blancafort, Lluís

    2010-05-21

    The role of the seam of intersection between the lowest (pi,pi*) and (n,pi*) excited states in the decay of electronically excited singlet thymine has been investigated with ab initio complete active space self-consistent field (CASSCF) calculations and direct dynamics variational multiconfiguration Gaussian (DD-vMCG) quantum dynamics on the full-dimensional CASSCF surface, with 39 degrees of freedom. The seam has a sloped-to-peaked topography, and the dynamics at the different segments of the seam have been studied by varying the initial conditions of the propagation. When the wave packet is directed to the peaked segments, part of it traverses the seam, stays on the (pi,pi*) state and heads towards decay to the ground state. In contrast to this, when the wave packet is driven to sloped seam segments it bounces back to the minimum of the (pi,pi*) state. Significant population transfer to the (n,pi*) state is observed in both cases. The results suggest that a sloped-to-peaked topography can be used to control photochemical reactivity, by driving the wave packet to different regions of the seam where a different outcome of the propagation can be expected.

  4. Modeling and finite element analysis of the nonstationary action on a multi-layer poroelastic seam with nonlinear geomechanical properties

    SciTech Connect

    Nasedkina, A.A.; Nasedkin, A.V.; Iovane, G.

    2009-07-15

    The paper discusses modeling of a multi-layer coal seam under hydrodynamic action based on the coupled equations of poroelasticity and filtration with the nonlinear relationship of permeability and porous pressure. The calculations by the finite element method use correspondence between the poroelasticity and thermoelasticity equations. The influence of input data on the size of a degassing hole area is analyzed for the couple problem and pure filtration problem.

  5. Design and synthesis of a new series of modified CH-diarylpyrimidines as drug-resistant HIV non-nucleoside reverse transcriptase inhibitors.

    PubMed

    Meng, Ge; Liu, Yang; Zheng, Aqun; Chen, Fener; Chen, Wenxue; De Clercq, Erik; Pannecouque, Christophe; Balzarini, Jan

    2014-07-23

    This article reports the design, synthesis and antiviral evaluation of a new series of non-nucleoside reverse transcriptase inhibitors (NNRTIs). The basic skeleton of these target 18 molecules is diarylpyrimidine featuring a substituted amino group between the pyrimidine scaffold and the aryl wing. All of the new compounds have been characterized by spectra analysis. The entire target molecules were evaluated for their in vitro anti-HIV activity with controlling group of FDA approved drugs. Most of them showed good to potent activities against wild-type (WT) HIV-1 with IC50 values in the range of 0.0175-69.21 μM. 2-(4-Cyanophenylamino)-4-(2-cyanovinylphenylhydrazonomethyl)pyrimidine (1d) displayed potent anti-HIV-1 activity against WT HIV-1 with a selectivity index (SI) of 106367 and an IC50 value of 1.75 nM, which was 47 fold lower than that of AZT. Compound 1d also showed a broad-spectrum inhibitory activity, with an IC50 value of 5.33 μM and 5.05 μM against both HIV-1 double-mutated (K103N/Y181C) strain and HIV-2 strain, respectively. The preliminary structure-activity relationship (SAR) was also investigated. The binding modes with HIV-1 RT for both the wild type and mutant type have also been discussed.

  6. Conical intersection seam and bound resonances embedded in continuum observed in the photodissociation of thioanisole-d3.

    PubMed

    Han, Songhee; Lim, Jeong Sik; Yoon, Jun-Ho; Lee, Jeongmook; Kim, So-Yeon; Kim, Sang Kyu

    2014-02-07

    Herein, the multi-dimensional nature of the conical intersection seam has been experimentally revealed in the photodissociation reaction of thioanisole-d3 (C6H5SCD3) excited on S1, giving C6H5S·(Ã or X̃]) +·CD3 products. The translational energy distribution of the nascent·CD3 fragment, reflecting the relative yields of the C6H5S·(Ã) and C6H5S·(X̃) products, was measured at each S1 vibronic band using the velocity map ion imaging technique. Direct access of the reactant flux to the conical intersection seam leads to the increase of the nonadiabatic transition probability resulting in sharp resonances in the X̃/ÃC6H5S·product branching ratio at several distinct S1 vibronic bands. The nature of the S1 vibronic bands associated with such dynamic resonances was clarified by the mass-analyzed threshold ionization spectroscopy. The bound state embedded in continuum generated by the conical intersection is observed as a distinct dynamic resonance, revealing the nature of the nuclear motion responsible for the nonadiabatic coupling of two potential energy surfaces at the conical intersection. The multi-dimensional facets of the conical intersection seam in terms of its detailed structure and dynamic role are discussed with the aid of theoretical calculations.

  7. Geochemical Characteristics of the Bismuth and Antimony Occurrence in Some Coal Seams in the Lublin Coal Basin (LCB)

    NASA Astrophysics Data System (ADS)

    Parzentny, Henryk R.; Róg, Leokadia

    2017-06-01

    The study included 24 samples of coal with 7 cores, boreholes (7 coal seams), made by the Polish Geological Institute in Warsaw at the site of a Chelm field and 6 coal samples taken from 2 decks in the Lublin Coal mine "Bogdanka" S.A. in LCB. Based on performed tests found generally low levels of Sb and Bi in coal. In the vertical profile of the LCB contents of Bi and Sb in coal generally increases from coal seams younger to older age. Content of Bi in coal from roof part coal seams is usually higher, and ash content in the coal content of Sb are generally lower than in the carbon of the middle part decks. The content of Bi in the lateral coal deposits is unlikely to vary, and the gap in the coal content of Bi between the sampling regions coal do not exceed 1.7 g / Mg. In contrast gap Sb content in coal on the extent LCB is from 1.7 g / Mg of 5.8 g / Mg. The biggest influence on the content of Bi and Sb in coal from the LCB is probably organic matter in which these elements are scattered and do not form their own minerals.

  8. Mobile hydrocarbon microspheres from >2-billion-year-old carbon-bearing seams in the South African deep subsurface.

    PubMed

    Wanger, G; Moser, D; Hay, M; Myneni, S; Onstott, T C; Southam, G

    2012-11-01

    By ~2.9 Ga, the time of the deposition of the Witwatersrand Supergroup, life is believed to have been well established on Earth. Carbon remnants of the microbial biosphere from this time period are evident in sediments from around the world. In the Witwatersrand Supergroup, the carbonaceous material is often concentrated in seams, closely associated with the gold deposits and may have been a mobile phase 2 billion years ago. Whereas today the carbon in the Witwatersrand Supergroup is presumed to be immobile, hollow hydrocarbon spheres ranging in size from <1 μm to >50 μm were discovered emanating from a borehole drilled through the carbon-bearing seams suggesting that a portion of the carbon may still be mobile in the deep subsurface. ToF-SIMS and STXM analyses revealed that these spheres contain a suite of alkane, alkenes, and aromatic compounds consistent with the described organic-rich carbon seams within the Witwatersrand Supergroup's auriferous reef horizons. Analysis by electron microscopy and ToF-SIMS, however, revealed that these spheres, although most likely composed of biogenic carbon and resembling biological organisms, do not retain any true structural, that is, fossil, information and were formed by an abiogenic process. © 2012 Blackwell Publishing Ltd.

  9. An Efficient Seam Elimination Method for UAV Images Based on Wallis Dodging and Gaussian Distance Weight Enhancement

    PubMed Central

    Tian, Jinyan; Li, Xiaojuan; Duan, Fuzhou; Wang, Junqian; Ou, Yang

    2016-01-01

    The rapid development of Unmanned Aerial Vehicle (UAV) remote sensing conforms to the increasing demand for the low-altitude very high resolution (VHR) image data. However, high processing speed of massive UAV data has become an indispensable prerequisite for its applications in various industry sectors. In this paper, we developed an effective and efficient seam elimination approach for UAV images based on Wallis dodging and Gaussian distance weight enhancement (WD-GDWE). The method encompasses two major steps: first, Wallis dodging was introduced to adjust the difference of brightness between the two matched images, and the parameters in the algorithm were derived in this study. Second, a Gaussian distance weight distribution method was proposed to fuse the two matched images in the overlap region based on the theory of the First Law of Geography, which can share the partial dislocation in the seam to the whole overlap region with an effect of smooth transition. This method was validated at a study site located in Hanwang (Sichuan, China) which was a seriously damaged area in the 12 May 2008 enchuan Earthquake. Then, a performance comparison between WD-GDWE and the other five classical seam elimination algorithms in the aspect of efficiency and effectiveness was conducted. Results showed that WD-GDWE is not only efficient, but also has a satisfactory effectiveness. This method is promising in advancing the applications in UAV industry especially in emergency situations. PMID:27171091

  10. An Efficient Seam Elimination Method for UAV Images Based on Wallis Dodging and Gaussian Distance Weight Enhancement.

    PubMed

    Tian, Jinyan; Li, Xiaojuan; Duan, Fuzhou; Wang, Junqian; Ou, Yang

    2016-05-10

    The rapid development of Unmanned Aerial Vehicle (UAV) remote sensing conforms to the increasing demand for the low-altitude very high resolution (VHR) image data. However, high processing speed of massive UAV data has become an indispensable prerequisite for its applications in various industry sectors. In this paper, we developed an effective and efficient seam elimination approach for UAV images based on Wallis dodging and Gaussian distance weight enhancement (WD-GDWE). The method encompasses two major steps: first, Wallis dodging was introduced to adjust the difference of brightness between the two matched images, and the parameters in the algorithm were derived in this study. Second, a Gaussian distance weight distribution method was proposed to fuse the two matched images in the overlap region based on the theory of the First Law of Geography, which can share the partial dislocation in the seam to the whole overlap region with an effect of smooth transition. This method was validated at a study site located in Hanwang (Sichuan, China) which was a seriously damaged area in the 12 May 2008 enchuan Earthquake. Then, a performance comparison between WD-GDWE and the other five classical seam elimination algorithms in the aspect of efficiency and effectiveness was conducted. Results showed that WD-GDWE is not only efficient, but also has a satisfactory effectiveness. This method is promising in advancing the applications in UAV industry especially in emergency situations.

  11. Long-term resistance to fracture and/or corrosion of the nitinol wires of the talent stent-graft: observations from a series of explanted devices.

    PubMed

    Lin, Jing; Guidoin, Robert; Wang, Lu; Zhang, Ze; Paynter, Royston; How, Thien; Nutley, Mark; Wei, Dangheng; Douville, Yvan; Samis, Gregory; Dionne, Guy; Gilbert, Nathalie

    2013-01-01

    The biodurability of the Nitinol wires used in stent-grafts retrieved from reoperations and autopsy was analyzed to assess the possible causes of fracture and/or corrosion of the stents. The Nitinol wires of six explanted devices presented a corrosion-free surface after in vivo service. The drawing lines in the control wires were still present, but neither burrs nor flakes were observed. Pits and crevices were rare, but some shallow ones were present. Some abrasions of the surfaces of the Nitinol wires were also observed. The chemical composition of the explanted devices showed the presence of organic contamination that covered the thick layer of titanium oxide before reaching the Nitinol itself. The durability of the Nitinol employed in the manufacture of the Talent stent-grafts was confirmed; the results of this study show the Nitinol to be resistant to corrosion. We have also concluded that the fractures of the Nitinol wires in two devices were unique adverse incidents caused by compression and bending related to the sharp angle of the Nitinol wires.

  12. Long-term impact of an educational antimicrobial stewardship program on hospital-acquired candidemia and multidrug-resistant bloodstream infections: a quasi-experimental study of interrupted time-series analysis.

    PubMed

    Molina, José; Peñalva, Germán; Gil-Navarro, María V; Praena, Julia; Lepe, José A; Pérez-Moreno, María A; Ferrándiz, Carmen; Aldabó, Teresa; Aguilar, Manuela; Olbrich, Peter; Jiménez-Mejías, Manuel E; Gascón, María L; Amaya-Villar, Rosario; Neth, Olaf; Rodríguez-Hernández, María J; Gutiérrez-Pizarraya, Antonio; Garnacho-Montero, José; Montero, Cristina; Cano, Josefina; Palomino, Julián; Valencia, Raquel; Álvarez, Rocío; Cordero, Elisa; Herrero, Marta; Cisneros, José M

    2017-08-07

    The global crisis of bacterial resistance urges the scientific community to implement intervention programs in healthcare facilities to promote an appropriate use of antibiotics. However, the clinical benefits or the impact on resistance of these interventions has not been definitively proven. We designed a quasi-experimental intervention study with an interrupted time-series analysis. A multidisciplinary team conducted a multifaceted educational intervention in our tertiary-care hospital over a five-year period. The main activity of the program consisted of peer-to-peer educational interviews between counselors and prescribers from all departments to reinforce the principles of the proper use of antibiotics. We assessed antibiotic consumption, incidence density of Candida and multidrug-resistant bacteria bloodstream infections (MDR-BSI) and their crude death rate per 1000 occupied bed days (OBD). A quick and intense reduction in antibiotic consumption occurred 6 months after the implementation of the intervention (change in level -216.8 DDD per 1000 OBD, 95% CI -347.5 to -86.1), and was sustained during subsequent years (average reduction -19,9%). Additionally, the increasing trend observed in the pre-intervention period for the incidence density of candidemia and MDR-BSI (+0.018 cases per 1000 OBD per quarter, 95% CI -0.003 to 0.039) reverted towards a decreasing trend of -0.130 per quarter (change in slope of -0.029, 95% CI -0.051 to -0.008), and so did their mortality (change in slope -0.015, 95% CI -0.021 to -0.008). This education-based ASP was effective in decreasing the incidence and mortality of hospital acquired candidemia and MDR-BSI through a sustained reduction in antibiotic use.

  13. Effects of androgen deprivation therapy and bisphosphonate treatment on bone in patients with metastatic castration-resistant prostate cancer: results from the University of Washington Rapid Autopsy Series.

    PubMed

    Morrissey, Colm; Roudier, Martine P; Dowell, Alex; True, Lawrence D; Ketchanji, Melanie; Welty, Christopher; Corey, Eva; Lange, Paul H; Higano, Celestia S; Vessella, Robert L

    2013-02-01

    Qualitative and quantitative bone features were determined in nondecalcified and decalcified bone from 20 predetermined bone sites in each of 44 patients who died with castration-resistant prostate cancer (CRPC), some of which received bisphosphonate treatment (BP) in addition to androgen-deprivation therapy (ADT). Thirty-nine of the 44 patients (89%) had evidence of bone metastases. By histomorphometric analysis, these bone metastases were associated with a range of bone responses from osteoblastic to osteolytic with a wide spectrum of bone responses often seen within an individual patient. Overall, the average bone volume/tissue volume (BV/TV) was 25.7%, confirming the characteristic association of an osteoblastic response to prostate cancer bone metastasis when compared with the normal age-matched weighted mean BV/TV of 14.7%. The observed new bone formation was essentially woven bone, and this was a localized event. In comparing BV/TV at metastatic sites between patients who had received BP treatment and those who had not, there was a significant difference (28.6% versus 19.3%, respectively). At bone sites that were not invaded by tumor, the average BV/TV was 10.1%, indicating significant bone loss owing to ADT that was not improved (11%) in those patients who had received BPs. Surprisingly, there was no significant difference in the number of osteoclasts present at the metastatic sites between patients treated or not treated with BPs, but in bone sites where the patient had been treated with BPs, giant osteoclasts were observed. Overall, 873 paraffin-embedded specimens and 661 methylmethacrylate-embedded specimens were analyzed. Our results indicate that in CRPC patients, ADT induces serious bone loss even in patients treated with BP. Furthermore, in this cohort of patients, BP treatment increased BV and did not decrease the number of osteoclasts in prostate cancer bone metastases compared with bone metastases from patients who did not receive BP.

  14. Development and assessment of new and existing canopy technology to lower coal seams

    SciTech Connect

    Mantel, J.

    1985-01-01

    The goal of this investigation was to increase safety in low-seam underground coal mines through development and in-mine evaluation of a temporary roof support system for roof drills and floor-riding operator compartments for a loader and shuttle car. During phase I, state-of-the art canopy technology was investigated, and preliminary design a mock-up evaluations were performed for temporary roof supports, single- and dual-boom bolters, and for transverse-mounted floor-riding canopies for a shuttle car and load loading machine. The shuttle car and loader canopies were approved for further development, and the design, fabrication, testing, and certification were completed in phase II. In phase III, the Bureau of Mines furnished a shuttle car for use in the evaluation of the canopy for 45 shifts. The shuttle car canopy was evaluated at the Virginia Crews Coal Co. in West Virginia. Efforts to secure an evaluation site for the loader canopy were unsuccessful.

  15. Coming apart at the seams: morphological evidence for pregnathal head capsule borders in adult Tribolium castaneum.

    PubMed

    Haas, Merrilee Susan; Beeman, Richard W

    2012-04-01

    Cephalization and seamless fusion of the anterior body segments during development obscure the segmental boundaries of the insect head. Most of the visible seams are thought to reflect cuticular infolding for structural reinforcement rather than a merger of cuticular plate borders. Incomplete fusions and other modifications of the adult head found in eight Tribolium mutations indicate that the frontal and gular sutures likely are true sutures that mark borders between adjacent cuticular plates, and suggest that the anterior facial shelf is a composite of three independent cuticular surfaces: ocular, antennal, and clypeo-labral. Additionally, midline splits of the clypeo-labrum and gula, and membranous lesions on the lateral head capsule reveal probable borders of adjacent cuticular plates where visible sutures are normally absent. The anterior lateral lesions seen in the Lucifer mutation mark a border between ocular and antennal plates and appear to identify part of the postfrontal sutures. While revealing or clarifying possible intersegmental borders between ocular, antennal, and clypeo-labral plates, the various modified or unfused surfaces of the head neither reveal an additional acronal plate nor support the view that the clypeo-labrum is segmentally associated with ocular cuticle.

  16. Multi-Seam Well Completion Technology: Implications for Powder River Basin Coalbed Methane Production

    SciTech Connect

    Office of Fossil Energy; National Energy Technology Laboratory

    2003-09-01

    The purpose of this study is to evaluate the potential benefits of applying multiseam [well] completion (MSC) technology to the massive stack of low-rank coals in the Powder River Basin. As part of this, the study objectives are: Estimate how much additional CBM resource would become accessible and technically recoverable--compared to the current practice of drilling one well to drain a single coal seam; Determine whether there are economic benefits associated with MSC technology utilization (assuming its widespread, successful application) and if so, quantify the gains; Briefly examine why past attempts by Powder River Basin CBM operators to use MSC technology have been relatively unsuccessful; Provide the underpinnings to a decision whether a MSC technology development and/or demonstration effort is warranted by DOE. To a great extent, this assessment builds on the previously published study (DOE, 2002), which contains many of the key references that underlie this analysis. It is available on the U.S. Department of Energy, National Energy technology Laboratory, Strategic Center for Natural Gas website (www.netl.doe.gov/scng). It is suggested that readers obtain a copy of the original study to complement the current report.

  17. The peculiarities of structurizing enclosing rock massif while developing a coal seam

    NASA Astrophysics Data System (ADS)

    Kozyreva, E. N.; Shinkevich, M. V.

    2017-09-01

    Different concepts of the development of geo-mechanical processes during longwall mining of a seam which are fundamentally different from the conventional ones are introduced in the article. Fundamental principles of the model for structurizing enclosing rock mass while longwall mining along the strike are described. The model was developed on the bases of non-linear geomechanical laws. According to the model, rock mass in the area of mining operation is organized as rock geomechanical layers with shifting arches. And the formation period of shifting arches in disintegrated rock mass is divisible by the length of the stope. Undulate characteristic of a massif as a peculiarity of man-made structurization of a massif is defined. It is shown that structuring the broken massif causes the formation of block-structured system and it can be detected while monitoring the ground pressure in powered support props. The results of the research allow decreasing the negative influence of a ground pressure and can be applied to specify parameters for controlling the roof, defining geometrical dimensions of a mining section and positioning of holing chute (face entry).

  18. Linear Mathematical Model for Seam Tracking with an Arc Sensor in P-GMAW Processes

    PubMed Central

    Liu, Wenji; Li, Liangyu; Hong, Ying; Yue, Jianfeng

    2017-01-01

    Arc sensors have been used in seam tracking and widely studied since the 80s and commercial arc sensing products for T and V shaped grooves have been developed. However, it is difficult to use these arc sensors in narrow gap welding because the arc stability and sensing accuracy are not satisfactory. Pulse gas melting arc welding (P-GMAW) has been successfully applied in narrow gap welding and all position welding processes, so it is worthwhile to research P-GMAW arc sensing technology. In this paper, we derived a linear mathematical P-GMAW model for arc sensing, and the assumptions for the model are verified through experiments and finite element methods. Finally, the linear characteristics of the mathematical model were investigated. In torch height changing experiments, uphill experiments, and groove angle changing experiments the P-GMAW arc signals all satisfied the linear rules. In addition, the faster the welding speed, the higher the arc signal sensitivities; the smaller the groove angle, the greater the arc sensitivities. The arc signal variation rate needs to be modified according to the welding power, groove angles, and weaving or rotate speed. PMID:28335425

  19. Detection of weld line and automatic seam tracking by ultrasonic sensing robot for underwater wet welding

    SciTech Connect

    Suga, Yasuo; Machida, Akira

    1994-12-31

    An underwater wet welding robot with an ultrasonic sensor was developed to detect the weld line and to track the weld line automatically. The robot can move the welding torch toward X and Y directions and the ultrasonic sensor can oscillate along the X direction. As the ultrasonic sensor, an immersion type probe of 9.0 mm in diameter was used. The frequency of the ultrasonic wave is 5.0 MHz. The spot size of the ultrasonic beam is approximately 2 mm at a water distance of 50 mm. As the result of the detecting experiment of weld line by the ultrasonic method, there was no problem in the case of as-received steel plate. However, when the surface condition of the base metal is poor, the robot sometimes makes misjudgment. In the tracking test of the butt weld line of steel plates, which has the angle of 30{degree} to the Y-axis, the tracking error was about 0.5 mm. As the result of the experiments, it was made clear that the robot system is effective on the automatic seam tracking of underwater wet welding.

  20. Palynology of an Early Permian coal seam from the Karoo Supergroup of Botswana

    NASA Astrophysics Data System (ADS)

    Barbolini, N.; Bamford, M. K.

    2014-12-01

    Two borehole cores from the south-east area of the Mmamantswe coalfield (Mmamabula area), Botswana, provided 124 samples for palynological analysis. The assemblage is dominated by trilete and alete spores, indicating a parent flora of mostly lower order lycopods, sphenophytes and ferns. Distinctive taxa at Mmamantswe include Brevitriletes levis, Cannanoropollis densus, Gondisporites raniganjensis, Platysaccus radialis, Scheuringipollenites ovatus, and Verrucosisporites naumovae. Saccate pollen is less common, suggesting the assemblage reflects the local vegetation of the coal swamp. The Mmamantswe microflora has been sub-divided into two assemblage zones, with the lower Assemblage Zone 1 correlating with Assemblage Zone 1 of Anderson (northern Karoo Basin, South Africa), Biozone B of the Waterberg (South Africa) and the Milorgfjella assemblage (Dronning Maud Land, Antarctica). The upper Assemblage Zone 2 of Mmamantswe is correlated with Assemblage Zone 2 of Anderson (northern Karoo Basin, South Africa), Biozone C of the Waterberg (South Africa), and the No. 2 Seam assemblage (Witbank coalfield, South Africa). On the basis of these correlations the Mmamantswe microfloral assemblage is assigned to the Asselian, Sakmarian and Early Artinskian periods.

  1. Estimating groundwater extraction in a data-sparse coal seam gas region, Australia

    NASA Astrophysics Data System (ADS)

    Keir, Greg; Bulovic, Nevenka; McIntyre, Neil

    2017-04-01

    The semi-arid Surat and Bowen Basins in central Queensland, Australia, are groundwater resources of both national and regional significance. Regional towns, agricultural industries and communities are heavily dependent on the 30 000+ groundwater supply bores for their existence; however groundwater extraction measurements are rare in this area and primarily limited to small irrigation regions. Accordingly, regional groundwater extraction is not well understood, and this may have implications for regional numerical groundwater modelling and impact assessments associated with recent coal seam gas developments. Here we present a novel statistical approach to model regional groundwater extraction that merges flow measurements / estimates with other more commonly available spatial datasets that may be of value, such as climate data, pasture data, surface water availability, etc. A three step modelling approach, combining a property scale magnitude model, a bore scale occurrence model, and a proportional distribution model within properties, is used to estimate bore extraction. We describe the process of model development and selection, and present extraction results on an aquifer-by-aquifer basis suitable for numerical groundwater modelling. Lastly, we conclude with recommendations for future research, particularly related to improvement of attribution of property-scale water demand, and temporal variability in water usage.

  2. Fate-mapping of the epithelial seam during palatal fusion rules out epithelial-mesenchymal transformation.

    PubMed

    Vaziri Sani, Forugh; Hallberg, Kristina; Harfe, Brian D; McMahon, Andrew P; Linde, Anders; Gritli-Linde, Amel

    2005-09-15

    During palatogenesis, fusion of the palatine shelves is a crucial event, the failure of which results in the birth defect, cleft palate. The fate of the midline epithelial seam (MES), which develops transiently upon contact of the two palatine shelves, is still strongly debated. Three major mechanisms underlying the regression of the MES upon palatal fusion have been proposed: (1) apoptosis has been evidenced by morphological and molecular criteria; (2) epithelial-mesenchymal transformation has been suggested based on ultrastructural and lipophilic dye cell labeling observations; and (3) migration of MES cells toward the oral and nasal areas has been proposed following lipophilic dye cell labeling. To verify whether epithelial-mesenchymal transformation of MES cells takes place during murine palatal fusion, we used the Cre/lox system to genetically mark Sonic hedgehog- and Keratin-14-expressing palatal epithelial cells and to identify their fate in vivo. Our analyses provide conclusive evidence that rules out the occurrence of epithelial-mesenchymal transformation of MES cells.

  3. Detailed spectroscopic analysis of SN 1987A: The distance to the LMC using the SEAM method

    SciTech Connect

    Mitchell, Robert C.; Baron, E.; Branch, David; Hauschildt, Peter H.; Nugent, Peter E.; Lundqvist, Peter; Blinnikov, Sergei; Pun, Chun S.J.

    2002-05-21

    Supernova 1987A remains the most well-studied supernova to date. Observations produced excellent broad-band photometric and spectroscopic coverage over a wide wavelength range at all epochs. We model the observed spectra from Day 1 to Day 81 using a hydrodynamical model. We show that good agreement can be obtained at times up to about 60 days, if we allow for extended nickel mixing. Later than about 60 days the observed Balmer lines become stronger than our models can reproduce. We show that this is likely due to a more complicated distribution of gamma-rays than we allow for in our spherically symmetric calculations. We present synthetic light curves in UBVRIJHK and a synthetic bolometric light curve. Using this broad baseline of detailed spectroscopic models we find a distance modulus mu = 18.5 +/- 0.2 using the SEAM method of determining distances to supernovae. We find that the explosion time agrees with that of the neutrino burst and is constrained at 68 percent confidence to within +/- 0.9 days. We argue that the weak Balmer lines of our detailed model calculations casts doubt on the accuracy of the purely photometric EPM method. We also suggest that Type IIP supernovae will be most useful as distance indicators at early times due to a variety of effects.

  4. Reactor cooling water expansion joint bellows: The role of the seam weld in fatigue crack development

    SciTech Connect

    West, S.L.; Nelson, D.Z.; Louthan, M.R. Jr.

    1992-12-01

    The secondary cooling water system pressure boundary of Savannah River Site reactors includes expansion joints utilizing a thin-wall bellows. While successfully used for over thirty years, an occasional replacement has been required because of the development of small, circumferential fatigue cracks in a bellows convolute. One such crack was recently shown to have initiated from a weld heat-affected zone liquation microcrack. The crack, initially open to the outer surface of the rolled and seam welded cylindrical bellows section, was closed when cold forming of the convolutes placed the outer surface in residual compression. However, the bellows was placed in tension when installed, and the tensile stresses reopened the microcrack. This five to eight grain diameter microcrack was extended by ductile fatigue processes. Initial extension was by relatively rapid propagation through the large-grained weld metal, followed by slower extension through the fine-grained base metal. A significant through-wall crack was not developed until the crack extended into the base metal on both sides of the weld. Leakage of cooling water was subsequently detected and the bellows removed and a replacement installed.

  5. Design of multi-level thick seam extractions under major aquifiers and considering spontaneous combustion risk

    SciTech Connect

    Reddish, D.J.; Dunham, R.K.

    1996-12-01

    The paper presents an approach to design a multi level room and pillar layout in a 40m thick seam overlain by a major aquifer. The design was required to maximize extraction with due consideration of the general stability of the workings, the potential water hazards, and spontaneous combustion risks due to air leakage between horizons. The approach utilized was a combination of empirical pillar sizing for water hazard control with numerical modelling to assess potential interactions between horizons. The numerical modelling allowed the size of interleaves, and the appropriate staggers to be optimized in terms of stress distribution. The stress distribution allows both the general stability of the openings and more importantly the permeability changes around the openings to be determined. The permeability of coal is sensitive to stress, and an empirical stress to permeability relationship, and theoretical permeability to flow leakage relationship has been applied to interpreting the relative spontaneous combustion risk associated with each of the proposed layouts. The final proposed design is a compromise between maximum exploitation of reserves and consideration of water hazards and of spontaneous combustion risk. Further more detailed design will be required as more comprehensive data on the geotechnical properties of the coal and overburden become available.

  6. Methanolobus zinderi sp. nov., a methylotrophic methanogen isolated from a deep subsurface coal seam.

    PubMed

    Doerfert, Sebastian N; Reichlen, Matthew; Iyer, Prabha; Wang, Mingyu; Ferry, James G

    2009-05-01

    A methanogenic organism from the domain Archaea (SD1(T)) was isolated from saline water released from a coal seam located 926 m below the surface via a methane-producing well near Monroe, Louisiana, USA. Growth and methanogenesis were supported with methanol, monomethylamine, dimethylamine or trimethylamine, but not with dimethylsulfide, formate, acetate or H(2)/CO(2). Cells grew in high-salt minimal medium but growth was stimulated with yeast extract or tryptone. Cells were single, non-motile, irregular coccoids 0.5-1.0 microm in diameter and the cell wall contained protein. Conditions for the maximum rate of growth were 40-50 degrees C, 0.2-0.6 M NaCl, 100->or=200 mM MgCl(2), and pH 7.0-8.0. The G+C content of the genomic DNA was 42+/-1mol %. A comparison of 16S rRNA gene sequences indicated that strain SD1(T) was most closely related to Methanolobus oregonensis DSM 5435(T) with 96 % gene sequence similarity. It is proposed that strain SD1(T) represents a novel species, Methanolobus zinderi sp. nov. The type strain is SD1(T) (=ATCC BAA-1601(T)=DSM 21339(T)).

  7. The effect of zeolite treatment by acids on sodium adsorption ratio of coal seam gas water.

    PubMed

    Wang, Xiaoyu; Ozdemir, Orhan; Hampton, Marc A; Nguyen, Anh V; Do, Duong D

    2012-10-15

    Many coal seam gas (CSG) waters contain a sodium ion concentration which is too high relative to calcium and magnesium ions for environment acceptance. Natural zeolites can be used as a cheap and effective method to control sodium adsorption ratio (SAR, which is a measure of the relative preponderance of sodium to calcium and magnesium) due to its high cation exchange capacity. In this study, a natural zeolite from Queensland was examined for its potential to treat CSG water to remove sodium ions to lower SAR and reduce the pH value. The results demonstrate that acid activated zeolite at 30%wt solid ratio can reduce the sodium content from 563.0 to 182.7 ppm; the pH from 8.74 to 6.95; and SAR from 70.3 to 18.5. Based on the results of the batch experiments, the sodium adsorption capacity of the acid-treated zeolite is three times greater than that of the untreated zeolite. Both the untreated and acid-treated zeolite samples were characterized using zeta potential, surface characterization, DTA/TG and particle size distribution in order to explain their adsorption behaviours.

  8. Emergency assessment of potential debris-flow peak discharges, Coal Seam fire, Colorado

    USGS Publications Warehouse

    Cannon, Susan H.; Michael, John A.; Gartner, Joseph E.; Rea, Alan H.; Garcia, Steven P.

    2002-01-01

    These maps present the results of assessments of peak discharges that can potentially be generated by debris flows issuing from the basins burned by the Coal Seam fire of June and July 2002, near Glenwood Springs, Colorado. The maps are based on a regression model for debris-flow peak discharge normalized by average storm intensity as a function of basin gradient and burned extent, and limited field checking. A range of potential peak discharges that could potentially be produced from each of the burned basins between 1 ft3/s (0.03 m3/s) and greater than 5,000 ft3/s (>141 m3/s) is calculated for the 5-year, 1-hour storm of 0.80 inches (20 mm). The 25-year, 1-hour storm of 1.3 inches (33 mm). The 100- year, 1-hour storm of 1.8 inches (46 mm) produced peak discharges between 1 and greater than 8,000 ft3/s (>227 m3/s). These maps are intended for use by emergency personnel to aid in the preliminary design of mitigation measures, and the planning of evacuation timing and routes.

  9. The effect of a cellulose dressing and topical vancomycin on methicillin-resistant Staphylococcus aureus (MRSA) and Gram-positive organisms in chronic wounds: a case series.

    PubMed

    Albaugh, Karen W; Biely, Scott A; Cavorsi, Joseph P

    2013-05-01

    High levels of persistent bacteria may contribute to wound chronicity and delayed healing. A prospective study was conducted to: 1) evaluate the effect of applying vancomycin topically on appropriately cultured chronic lower leg wounds, specifically methicillin-resistant Staphylococcus aureus (MRSA) and Gram-positive bacteria, and 2) evaluate its effect in combination with a cellulose dressing on healing. Twenty-three (23) outpatients (11 men, 12 women, average age 65 years [range 39-89 years]) with lower extremity wounds (15 venous ulcers, six chronic open wounds with a history of diabetes, and two chronic open trauma wounds) averaging 43.58 weeks' (range 5-121 weeks) duration and swab-cultured positive for MRSA or Gram-positive bacteria were provided 1 g vancomycin delivered by a cellulose dressing and changed every 72 hours. Patients served as their own control, and all wounds were debrided once a week. Wound surface area and bacterial and exudate levels were recorded weekly during the 3-week pretreatment period and compared to 3-week treatment period levels. Patients were followed until healed. Mean change in wound surface area was +14.5% (SD 71.91) per week before and -24.6% (SD 13.59) during the vancomycin treatment period (P = 0.014), average exudate levels decreased from 2.75 (range 1-4) to 1.81 (range 0-3) (P = 0.016), and the number of patients with positive wound cultures for MRSA or Gram-positive bacteria decreased from 23 to four after the 3-week study period. All wounds healed after an average of 8.18 weeks (SD 4.76, range 2-17 weeks). The results of this study suggest topical vancomycin applied using a dressing that retains moisture reduces wound bacterial load and may facilitate healing. Randomized, controlled clinical studies to evaluate the effectiveness and efficacy of this treatment modality and explore the relationship between wound culture results and healing are warranted.

  10. Influence of the post-weld surface treatment on the corrosion resistance of the duplex stainless steel 1.4062

    NASA Astrophysics Data System (ADS)

    Rosemann, P.; Müller, C.; Baumann, O.; Modersohn, W.; Halle, T.

    2017-03-01

    The duplex stainless steel 1.4062 (X2CrNiN22-2) is used as alternative material to austenitic stainless steels in the construction industry. The corrosion resistance of welded seams is influenced by the base material, the weld filler material, the welding process and also by the final surface treatment. The scale layer next to the weld seam can be removed by grinding, pickling, electro-polished or blasting depending on the application and the requested corrosion resistance. Blasted surfaces are often used in industrial practice due to the easier and cheaper manufacturing process compared to pickled or electro-polished surfaces. Furthermore blasting with corundum-grain is more effective than blasting with glass-beads which also lower the process costs. In recent years, stainless steel surfaces showed an unusually high susceptibility to pitting corrosion after grinding with corundum. For this reason, it is now also questioned critically whether the corrosion resistance is influenced by the applied blasting agent. This question was specifically investigated by comparing grinded, pickled, corundum-grain- and glass-bead-blasted welding seams. Results of the SEM analyses of the blasting agents and the blasted surfaces will be presented and correlated with the different performed corrosion tests (potential measurement, KorroPad-test and pitting potential) on welding seams with different surface treatments.

  11. Mineralogical and microstructural investigations of fractures in Permian z2 potash seam and surrounding salt rocks

    NASA Astrophysics Data System (ADS)

    Mertineit, Michael; Grewe, Wiebke; Schramm, Michael; Hammer, Jörg; Blanke, Hartmut; Patzschke, Mario

    2017-04-01

    Fractures occur locally in the z2 potash seam (Kaliflöz Staßfurt). Most of them extend several centimeter to meter into the surrounding salt rocks. The fractures are distributed on all levels in an extremely deformed area of the Morsleben salt mine, Northern Germany. The sampling site is located within a NW-SE trending synclinal structure, which was reverse folded (Behlau & Mingerzahn 2001). The samples were taken between the -195 m and - 305 m level at the field of Marie shaft. In this area, more than 200 healed fractures were mapped. Most of them show opening widths of only a few millimeters to rarely 10 cm. The fractures in rock salt are filled with basically polyhalite, halite and carnallite. In the potash seam, the fractures are filled with kainite, halite and minor amounts of carnallite and polyhalite. In some cases the fracture infill changes depending on the type of surrounding rocks. There are two dominant orientations of the fractures, which can be interpreted as a conjugated system. The main orientation is NE-SW trending, the dip angles are steep (ca. 70°, dip direction NW and SE, respectively). Subsequent deformation of the filled fractures is documented by a strong grain shape fabric of kainite, undulatory extinction and subgrain formation in kainite, and several mineral transformations. Subgrain formation in halite occurred in both, the fracture infill and the surrounding salt rocks. The results correlate in parts with investigations which were carried out at the close-by rock salt mine Braunschweig-Lüneburg (Horn et al. 2016). The development of the fractures occurred during compression of clayey salt rocks. However, the results are only partly comparable due to different properties (composition, impurities) of the investigated stratigraphic units. Further investigations will focus on detailed microstructural and geochemical analyses of the fracture infill and surrounding salt rocks. Age dating of suitable minerals, e.g. polyhalite (Leitner et al

  12. CO2 sequestration in deep coal seams: experimental characterization of the fundamental underlying mechanisms

    NASA Astrophysics Data System (ADS)

    Pini, R.; Mazzotti, M.

    2012-04-01

    The process of injecting and storing carbon dioxide (CO2) into suitable deep geological formations, such as saline aquifers, (depleted) oil or gas reservoirs, and unmineable coal seams, is referred to as CO2 sequestration. In little more than a decade, this technology has emerged as one of the most important options for reducing CO2 emissions. Among the different options, unmineable coal seams are not as broadly distributed as saline aquifers or oil/gas reservoirs, but their peculiarity resides in the proven capacity of retaining significant amount of gas (mainly methane, CH4) for a very long time. Additionally, the injection of CO2 into the coal reservoir would enhance the recovery of this natural gas, a source of energy that will most likely play a key role in the power sector over the next 20 years from now. This process is called Enhanced Coal Bed Methane (ECBM) recovery and, as for enhanced oil recovery, it allows in principle offsetting the costs associated to the storage operation. A study was undertaken aimed at the experimental characterization of the fundamental mechanisms that take place during the process of injection and storage in coal reservoirs, namely adsorption and swelling (Pini et al 2010), and of their effects on the coal's permeability (Pini et al. 2009), the property that plays a dominant role in controlling fluid transport in a porous rock. An apparatus has been built that allows measuring the permeability of rock cores under typical reservoir conditions (high pressure and temperature) by the so-called transient step method. For this study, a coal core from the Sulcis coal mine in Sardinia (Italy) has been used. In the experiments, an inert gas (helium) was used to investigate the effects of the effective pressure on the permeability of the coal sample, whereas two adsorbing gases (CO2 and N2) to quantify those of adsorption and swelling. The experiments have been interpreted by a one-dimensional model that describes the fluid transport

  13. Impact of routine surgical ward and intensive care unit admission surveillance cultures on hospital-wide nosocomial methicillin-resistant Staphylococcus aureus infections in a university hospital: an interrupted time-series analysis.

    PubMed

    Chaberny, Iris F; Schwab, Frank; Ziesing, Stefan; Suerbaum, Sebastian; Gastmeier, Petra

    2008-12-01

    To determine whether a routine admission screening in surgical wards and intensive care units (ICUs) was effective in reducing methicillin-resistant Staphylococcus aureus (MRSA) infections-particularly nosocomial MRSA infections-for the whole hospital. The study used a single-centre prospective quasi-experimental design to evaluate the effect of the MRSA screening policy on the incidence density of MRSA-infected/nosocomial MRSA-infected patients/1000 patient-days (pd) in the whole hospital. The effect on incidence density was calculated by a segmented regression analysis of interrupted time series with 30 months prior to and 24 months after a 6 month implementation period. The MRSA screening policy had a highly significant hospital-wide effect on the incidence density of MRSA infections. It showed a significant change in both level [-0.163 MRSA-infected patients/1000 pd, 95% confidence interval (CI): -0.276 to -0.050] and slope (-0.01 MRSA-infected patients/1000 pd per month, 95% CI: -0.018 to -0.003) after the implementation of the MRSA screening policy. A decrease in the MRSA infections by 57% is a conservative estimate of the reduction between the last month before (0.417 MRSA-infected patients/1000 pd) and month 24 after the implementation of the MRSA screening policy (0.18 MRSA-infected patients/1000 pd). Equivalent results were found in the analysis of nosocomial MRSA-infected patients/1000 pd. This is the first hospital-wide study that investigates the impact of introducing admission screening in ICUs and non-ICUs as a single intervention to prevent MRSA infections performed with a time-series regression analysis. Admission screening is a potent tool in controlling the spread of MRSA infections in hospitals.

  14. Integrated stratigraphy of Paleocene lignite seams of the fluvial Tullock Formation, Montana (USA).

    NASA Astrophysics Data System (ADS)

    Noorbergen, Lars J.; Kuiper, Klaudia F.; Hilgen, Frederik J.; Krijgsman, Wout; Dekkers, Mark J.; Smit, Jan; Abels, Hemmo A.

    2015-04-01

    Coal-bearing fluvial sedimentation is generally thought to be dominated by autogenic processes that are processes intrinsic to the sedimentary system. Ongoing research however suggests that several fluvial processes such as floodplain inundation and avulsion, can also be controlled by external forcing such as orbital climate change. Still, the exact role of orbital climate forcing in fluvial sediments is difficult to decipher since riverine deposits are complicated by variable sedimentation rates including erosion of previously deposited material, by lateral heterogeneity of sedimentation, and by scarcity of independent dating methods. The early Paleocene lignite-bearing Tullock Formation of the Williston Basin in eastern Montana represents a record of fluvial sedimentation that is perfectly exposed and, displays a seemingly regular alternation of sandstones and lignite seams. These coal beds contain multiple volcanic ash layers. Here, we use an integrated stratigraphic approach (litho- and magnetostratigraphy, geochemical fingerprinting and radio-isotope dating of volcanic ash layers) to establish a high-resolution time frame for the early Paleocene fluvial sediments. First age estimations indicate that the Tullock Formation in Eastern Montana was deposited over a time span of ~ 1000 kyr subsequent to the Cretaceous - Paleogene boundary, dated at ~ 65.95 Ma [1]. Initial high-resolution magnetostratigraphy revealed the occurrence of the C29r/C29n polarity reversal which was stratigraphic consistent at different field locations. We investigate the regional significance of sedimentary change at multiple sites of the same age in order to provide improved insight on the role of orbital forcing in fluvial coal formation. References: [1] Kuiper, K.F., Deino, A., Hilgen, F.J., Krijgsman, W., Renne, P.R., Wijbrans, J.R. (2008). Synchronizing Rock Clocks of Earth History. Science 320, 500-504.

  15. Coal cleaning: Progress and potential. [Deep and moderate cleaning of coal from different seams

    SciTech Connect

    Livengood, C.D.; Doctor, R.D.

    1986-11-01

    Results from a detailed analysis of sulfur dioxide (SO/sub 2/) reductions achievable through ''deep'' physical coal cleaning (PCC) at 20 coal-fired power plants in the Ohio-Indiana-Illinois region are presented here. These plants all have capacities larger than 500 MWe, are currently without any flue-gas-desulfurization (FGD) systems, and burn coal of greater than 1% sulfur content (in 1980). Their aggregate emissions of 2.4 million tons of SO/sub 2/ per year represent 55% of the SO/sub 2/ inventory for these states. The principal coal supplies for each power plant were identified and characterized as to coal seam and county of origin, so that published coal-washability data could be matched to each supplier. The SO/sub 2/ reductions that would result from deep cleaning (Level 4) and moderate cleaning (Level 3) of each coal were calculated using a PCC computer model. For deep cleaning, percentage reductions in sulfur content ranged from zero to 52%, with a mean value of 29%, and costs ranged from a low of $364/ton SO/sub 2/ removed to over $2000/ton SO/sub 2/ removed. Because coal suppliers to these power plants employ some voluntary coal cleaning, the anticipated emissions reduction from current levels if deep cleaning were used should be near 20%. These emissions reductions were projected using conventional coal-cleaning-circuit designs. The basic elements of typical commercial PCC designs are briefly described, and current research and development activities in physical, chemical, and biological desulfurization of coal are reviewed. Possible governmental actions to either encourage or mandate coal cleaning are identified and evaluated.

  16. Data base for the analysis of compositional characteristics of coal seams and macerals. Quarterly technical progress report, August-October 1980

    SciTech Connect

    Davis, Alan; Suhr, N. H.; Spackman, W.; Painter, P. C.; Walker, P. L.; Given, P. H.

    1981-02-01

    A total of 69 samples have been obtained from the Lower Kittanning seam in western Pennyslvania and eastern Ohio. The samples were taken from 39 sample sites and consist of 39 channel samples and 30 hand-picked vitrinites. A complex statistical analysis of petrographic, physical and chemical properties of these samples was performed in order to study their relationship with thermoplastic and liquefaction behavior. The parameters of the thermoplastic properties were obtained using a Gieseler plastometer. The liquefaction conversion with tetralin was determined in tubing bomb reactors at 400/sup 0/C for 1 hour. Factor analysis on the whole sample population indicated that both liquefaction conversion and some of the measured thermoplastic properties are significantly related with rank. Temperature of softening and degree of fluidity, however, did not load on the rank component. /sup 13/C nmr spectra were obtained for six of our vitrinite concentrates by the University of Utah. The aromaticities determined for fairly wide rank range of these samples varied only from 0.66 to 0.72. However the series showed progression from highly functional aromatic structure at low rank to one with little functionality at high rank. The spectra show no indication of a consistent loss in aliphatic oxygen. The surface areas and micropore volumes of two fractions, -20 and -100 mesh, of five vitrinite concentrates have been measured from CO/sub 2/ uptake at 25/sup 0/C. An increase in these values is observed with decreasing particle size. Total open pore volumes were calculated from particle and helium densities.

  17. Is Increasing Coal Seam Gas Well Development Activity Associated with Increasing Hospitalisation Rates in Queensland, Australia? An Exploratory Analysis 1995–2011

    PubMed Central

    Werner, Angela K.; Cameron, Cate M.; Watt, Kerrianne; Vink, Sue; Jagals, Paul; Page, Andrew

    2017-01-01

    The majority of Australia’s coal seam gas (CSG) reserves are in Queensland, where the industry has expanded rapidly in recent years. Despite concerns, health data have not been examined alongside CSG development. This study examined hospitalisation rates as a function of CSG development activity in Queensland, during the period 1995–2011. Admissions data were examined with CSG well numbers, which served as a proxy for CSG development activity. Time series models were used to assess changes in hospitalisation rates for periods of “low”, “medium”, “high”, and “intense” activity compared to a period of “very low” activity, adjusting for covariates. “All-cause” hospitalisation rates increased monotonically with increasing gas well development activity in females (324.0 to 390.3 per 1000 persons) and males (294.2 to 335.4 per 1000 persons). Hospitalisation rates for “Blood/immune” conditions generally increased for both sexes. Female and male hospitalisation rates for “Circulatory” conditions decreased with increasing CSG activity. Hospitalisation rates were generally low for reproductive and birth outcomes; no clear associations were observed. This study showed some outcomes were associated with increasing CSG development activity. However, as a condition of data access, the population and outcomes were aggregated to a broad geographic study area rather than using higher geographic resolution data. Higher resolution data, as well as other data sources, should be explored. Further research should be conducted with an expanded time period to determine if these trends continue as the industry grows. PMID:28524113

  18. The Caenorhabditis elegans GATA factor elt-1 is essential for differentiation and maintenance of hypodermal seam cells and for normal locomotion.

    PubMed

    Smith, Judith A; McGarr, Pamela; Gilleard, John S

    2005-12-15

    The Caenorhabditis elegans GATA transcription factor elt-1 has previously been shown to have a central role in the specification of hypodermal (epidermal) cell fates and acts several cell divisions before the birth of hypodermal cells. Here we report that elt-1 also has essential functions during subsequent development. Reporter gene studies show that elt-1 expression is maintained in lateral seam cells throughout development and elt-1 RNA interference experiments support an essential role for elt-1 in the differentiation of lateral seam cells in the embryo. The maintenance of seam-cell fates in all larval stages including L2d and dauer also requires elt-1. The elt-1 RNAi phenotype shows that seam cells are essential for the structural integrity of adult hermaphrodites in the vulval region and for diametric shrinkage during dauer larval formation. By contrast, severe seam-cell loss in the larval stages has little effect on moulting, indicating that the presence of these cells is not essential for this process. The elt-1 reporter gene is also expressed in neurones of the locomotory circuit. Loss of elt-1 function during postembryonic development results in a hypermotility phenotype whereas overexpression of elt-1 leads to a reciprocal phenotype of reduced motility and paralysis. These results suggest that elt-1 is a key regulator of neuronal function in larvae and adult worms.

  19. A Combined Micro-CT Imaging/Microfluidic Approach for Understating Methane Recovery in Coal Seam Gas Reservoirs

    NASA Astrophysics Data System (ADS)

    Mostaghimi, P.; Armstrong, R. T.; Gerami, A.; Lamei Ramandi, H.; Ebrahimi Warkiani, M.

    2015-12-01

    Coal seam methane is a form of natural gas stored in coal beds and is one of the most important unconventional resources of energy. The flow and transport in coal beds occur in a well-developed system of natural fractures that are also known as cleats. We use micro-Computed Tomography (CT) imaging at both dry and wet conditions to resolve the cleats below the resolution of the image. Scanning Electron Microscopy (SEM) is used for calibration of micro-CT data. Using soft lithography technique, the cleat system is duplicated on a silicon mould. We fabricate a microfluidic chip using Polydimethylsiloxane (PDMS) to study both imbibition and drainage in generated coal structures for understating gas and water transport in coal seam reservoirs. First, we use simple patterns observed on coal images to analyse the effects of wettability, cleat size and distribution on flow behaviour. Then, we study transport in a coal by injecting both distilled water and decane with a rate of 1 microliter/ min into the fabricated cleat structure (Figure 1), initially saturated with air. We repeat the experiment for different contact angles by plasma treating the microfluidic chip, and results show significant effects of wettability on the displacement efficiency. The breakthrough time in the imbibition setup is significantly longer than in the drainage. Using rapid video capturing, and high resolution microscopy, we measure the saturation of displacing fluid with respect to time. By measuring gas and liquid recovery in the outlet at different saturation, we predict relative permeability of coal. This work has important applications for optimising gas recovery and our results can serve as a benchmark in the verification of multiphase numerical models used in coal seam gas industry.

  20. Volumetric strain associated with methane desorption and its impact on coalbed gas production from deep coal seams

    SciTech Connect

    Cui, X.J.; Bustin, R.M.

    2005-09-01

    For deep coal seams, significant reservoir pressure drawdown is required to promote gas desorption because of the Langmuir-type isotherm that typifies coals. Hence, a large permeability decline may occur because of pressure drawdown and the resulting increase in effective stress, depending on coal properties and the stress field during production. However, the permeability decline can potentially be offset by the permeability enhancement caused by the matrix shrinkage associated with methane desorption. The predictability of varying permeability is critical for coalbed gas exploration and production-well management. We have investigated quantitatively the effects of reservoir pressure and sorption-induced volumetric strain on coal-seam permeability with constraints from the adsorption isotherm and associated volumetric strain measured on a Cretaceous Mesaverde Group coal (Piceance basin) and derived a stress-dependent permeability model. Our results suggest that the favorable coal properties that can result in less permeability reduction during earlier production and an earlier strong permeability rebound (increase in permeability caused by coal shrinkage) with methane desorption include (1) large bulk or Young's modulus; (2) large adsorption or Langmuir volume; (3) high Langmuir pressure; (4) high initial permeability and dense cleat spacing; and (5) low initial reservoir pressure and high in-situ gas content. Permeability variation with gas production is further dependent on the orientation of the coal seam, the reservoir stress field, and the cleat structure. Well completion with injection of N2 and displacement of CH{sub 4} only results in short-term enhancement of permeability and does not promote the overall gas production for the coal studied.

  1. On the Frequency and Voltage-Dependent Profiles of the Surface States and Series Resistance of Au/ZnO/n-Si Structures in a Wide Range of Frequency and Voltage

    NASA Astrophysics Data System (ADS)

    Nikravan, Afsoun; Badali, Yosef; Altındal, Şemsettin; Uslu, İbrahim; Orak, İkram

    2017-06-01

    In order to interpret the electrical characteristics of fabricated Au/ZnO/n-Si structures as a function of frequency and voltage well, their capacitance-voltage (C-V) and conductance-voltage (G/ω-V) measurements were carried out in a wide range of frequencies (0.7 kHz-2 MHz) and voltages (± 6 V) by 50 mV steps at room temperature. Both the C-V and G/ω-V plots have reverse, depletion, and accumulation regions such as a metal-insulator/oxide semiconductor (MIS or MOS) structures. The values of doped-donor atoms (N D), Fermi energy level (E F), barrier height (ΦB), and series resistance (R s) of the structure were obtained as a function of frequency and voltage. While the value of N D decreases with increasing frequency almost as exponentially, the value of depletion width (W D) increases. The values of C and G/ω increase with decreasing frequency because the surface states (N ss) are able to follow the alternating current (AC) signal, resulting in excess capacitance (C ex) and conductance (G ex/ω), which depends on their relaxation time and the frequency of the AC signal. The voltage-dependent profiles of N ss were obtained from both the high-low frequency capacitance and Hill-Colleman methods. The other important parameter R s of the structure was also obtained from the Nicollian and Brews methods as a function of voltage.

  2. On the Frequency and Voltage-Dependent Profiles of the Surface States and Series Resistance of Au/ZnO/n-Si Structures in a Wide Range of Frequency and Voltage

    NASA Astrophysics Data System (ADS)

    Nikravan, Afsoun; Badali, Yosef; Altındal, Şemsettin; Uslu, İbrahim; Orak, İkram

    2017-10-01

    In order to interpret the electrical characteristics of fabricated Au/ZnO/n-Si structures as a function of frequency and voltage well, their capacitance-voltage ( C- V) and conductance-voltage ( G/ ω- V) measurements were carried out in a wide range of frequencies (0.7 kHz-2 MHz) and voltages (± 6 V) by 50 mV steps at room temperature. Both the C- V and G/ ω- V plots have reverse, depletion, and accumulation regions such as a metal-insulator/oxide semiconductor (MIS or MOS) structures. The values of doped-donor atoms ( N D), Fermi energy level ( E F), barrier height (ΦB), and series resistance ( R s) of the structure were obtained as a function of frequency and voltage. While the value of N D decreases with increasing frequency almost as exponentially, the value of depletion width ( W D) increases. The values of C and G/ ω increase with decreasing frequency because the surface states ( N ss) are able to follow the alternating current (AC) signal, resulting in excess capacitance ( C ex) and conductance ( G ex/ ω), which depends on their relaxation time and the frequency of the AC signal. The voltage-dependent profiles of N ss were obtained from both the high-low frequency capacitance and Hill-Colleman methods. The other important parameter R s of the structure was also obtained from the Nicollian and Brews methods as a function of voltage.

  3. Modelling of a coal seam of the deposit Đurđevik (BiH) by means of 2D reflection seismic imaging

    NASA Astrophysics Data System (ADS)

    Arsenović, Siniša; Urošević, Milovan; Sretenović, Branislav; Cvetkov, Vesna; Životić, Dragana

    2016-06-01

    A low cost 2D reflection seismic survey was used to map the continuity of the main seams as well as the numerous faults at the Đurđevik sub-bituminous coal deposit (BiH). A 24-channel seismic data acquisition system was available for this survey. The natural high reflectivity of the coal seams and a favourable geometry of seismic profiles enabled the identification and correlation of major faults across the area. Rugged terrain presented challenges to both data acquisition and processing. Stacks of acceptable quality were obtained only after the application of surface consistent statics and careful application of multi-channel filtering. A set of recorded 2D lines was interpreted in a 3D environment. Inferred structural elements disrupting the seam continuity were identified and were in agreement with available drilling results and mine workings. The result of this work was used to reduce mining hazards and also to help optimise mine planning.

  4. Automated global mapping of minimal energy points on seams of crossing by the anharmonic downward distortion following method: a case study of H2CO.

    PubMed

    Maeda, Satoshi; Ohno, Koichi; Morokuma, Keiji

    2009-03-05

    Automated global mapping of minimal energy points on seams of crossing (MSX structures) were performed by using the anharmonic downward distortion following (ADD-following) method, which has previously been applied to the single potential energy surfaces (PESs) to perform automated global reaction route mapping. In this study, the ADD-following is applied to a penalty function based on two PESs of different electronic states. The present approach is effective not only for crossing seams between states with different symmetry but also for conical intersections for states with the same symmetry. Many new MSX structures were discovered on the S(0)/T(1) and S(1)/T(1) crossing seams and the S(0)/S(1) conical intersections of H(2)CO by automated global mapping using the ADD-following method. A possible pathway for dissociation of formaldehyde excited to S(1) at low energy is discussed.

  5. Characteristics of Extra Narrow Gap Weld of HSLA Steel Welded by Single-Seam per Layer Pulse Current GMA Weld Deposition

    NASA Astrophysics Data System (ADS)

    Agrawal, B. P.; Ghosh, P. K.

    2017-03-01

    Butt weld joints are produced using pulse current gas metal arc welding process by employing the technique of centrally laid multi-pass single-seam per layer weld deposition in extra narrow groove of thick HSLA steel plates. The weld joints are prepared by using different combination of pulse parameters. The selection of parameter of pulse current gas metal arc welding is done considering a summarized influence of simultaneously interacting pulse parameters defined by a dimensionless hypothetical factor ϕ. The effect of diverse pulse parameters on the characteristics of weld has been studied. Weld joint is also prepared by using commonly used multi-pass multi-seam per layer weld deposition in conventional groove. The extra narrow gap weld joints have been found much superior to the weld joint prepared by multi-pass multi-seam per layer deposition in conventional groove with respect to its metallurgical characteristics and mechanical properties.

  6. Characteristics of Extra Narrow Gap Weld of HSLA Steel Welded by Single-Seam per Layer Pulse Current GMA Weld Deposition

    NASA Astrophysics Data System (ADS)

    Agrawal, B. P.; Ghosh, P. K.

    2017-02-01

    Butt weld joints are produced using pulse current gas metal arc welding process by employing the technique of centrally laid multi-pass single-seam per layer weld deposition in extra narrow groove of thick HSLA steel plates. The weld joints are prepared by using different combination of pulse parameters. The selection of parameter of pulse current gas metal arc welding is done considering a summarized influence of simultaneously interacting pulse parameters defined by a dimensionless hypothetical factor ϕ. The effect of diverse pulse parameters on the characteristics of weld has been studied. Weld joint is also prepared by using commonly used multi-pass multi-seam per layer weld deposition in conventional groove. The extra narrow gap weld joints have been found much superior to the weld joint prepared by multi-pass multi-seam per layer deposition in conventional groove with respect to its metallurgical characteristics and mechanical properties.

  7. Rock-magnetic properties of TRM carrying baked and molten rocks straddling burnt coal seams

    NASA Astrophysics Data System (ADS)

    de Boer, Cor B.; Dekkers, Mark J.; van Hoof, Ton A. M.

    2001-10-01

    The subsurface spontaneous combustion of coal seams in Xinjiang (NW China) during Pleistocene to recent times produced large areas of thermally altered sedimentary rocks with large magnetic moments. The natural remanent magnetization (NRM) and thermoremanent magnetization (TRM) intensities and low-field susceptibilities of such combustion-metamorphic rocks range from 0.1 to 10 A/m and 100×10 -4 to 1000×10 -4 SI, respectively, which is two to three orders of magnitude higher than values typical of their sedimentary protoliths. The dominant magnetic carriers in the burnt rocks appear to include relatively pure forms of magnetite, maghemite and hematite as well as more complex spinel phases. These magnetic phases mainly occur as fine pseudo-single-domain (PSD) particles. Conspicuous is the presence of pure metallic iron (αFe) in some samples. This highly magnetic phase is inferred to appear as more or less elongated super paramagnetic and single-domain (SD) inclusions in host silicate phases, which prevent them from oxidizing. The SD αFe particles can carry a highly stable remanence, having remanent coercivities ranging 70-140 mT. The ARM and IRM stability of all burnt rock samples to alternating fields is shown to be relatively high; median destructive fields, B(1/2)A and B(1/2)I, respectively, range of 25-46 and ˜20-30 mT for dominant spinel-bearing samples, 34-36 and 47-53 mT for maghemite-hematite-bearing samples, and 48-89 and 64-84 mT for metallic iron-bearing samples. Consequently, burnt rocks are high-quality geomagnetic field recorders. Their very nature makes them useful for paleointensity determinations, although age determination is a limiting factor. Furthermore, remanence intensities and susceptibilities of these magnetically enhanced rocks are sufficient to produce observable magnetic anomalies. This property illustrates the potential to delineate the areal extent and depth of (extinct) coal fires with magnetic exploration. Such information is

  8. All-age hospitalization rates in coal seam gas areas in Queensland, Australia, 1995-2011.

    PubMed

    Werner, Angela K; Watt, Kerrianne; Cameron, Cate M; Vink, Sue; Page, Andrew; Jagals, Paul

    2016-02-06

    Unconventional natural gas development (UNGD) is expanding globally, with Australia expanding development in the form of coal seam gas (CSG). Residents and other interest groups have voiced concerns about the potential environmental and health impacts related to CSG. This paper compares objective health outcomes from three study areas in Queensland, Australia to examine potential environmentally-related health impacts. Three study areas were selected in an ecologic study design: a CSG area, a coal mining area, and a rural/agricultural area. Admitted patient data, as well as population data and additional factors, were obtained for each calendar year from 1995 through 2011 to calculate all-age hospitalization rates and age-standardized rates in each of these areas. The three areas were compared using negative binomial regression analyses (unadjusted and adjusted models) to examine increases over time of hospitalization rates grouped by primary diagnosis (19 ICD chapters), with rate ratios serving to compare the within-area regression slopes between the areas. The CSG area did not have significant increases in all-cause hospitalization rates over time for all-ages compared to the coal and rural study areas in adjusted models (RR: 1.02, 95 % CI: 1.00-1.04 as compared to the coal mining area; RR: 1.01, 95 % CI: 0.99-1.04 as compared to the rural area). While the CSG area did not show significant increases in specific hospitalization rates compared to both the coal mining and rural areas for any ICD chapters in the adjusted models, the CSG area showed increases in hospitalization rates compared only to the rural area for neoplasms (RR: 1.09, 95 % CI: 1.02-1.16) and blood/immune diseases (RR: 1.14, 95 % CI: 1.02-1.27). This exploratory study of all-age hospitalization rates for three study areas in Queensland suggests that certain hospital admissions rates increased more quickly in the CSG study area than in other study areas, particularly the rural area, after adjusting

  9. Analysis of alternatives for using cable bolts as primary support at two low-seam coal mines.

    PubMed

    Esterhuizen, Gabriel S; Tulu, Ihsan B

    2016-01-01

    Cable bolts are sometimes used in low-seam coal mines to provide support in difficult ground conditions. This paper describes cable bolting solutions at two low-seam coal mines in similar ground conditions. Both mines used support systems incorporating cable bolts as part of the primary support system. Two original cable bolt based support systems as well as two modified systems are evaluated to estimate their ability to prevent large roof falls. One of the support systems incorporated passive cable bolts, while the other used pre-tensioned cable bolts. The results and experience at the mines showed that the modified systems provided improved stability over the original support systems. The presence of the cable bolts is the most important contribution to stability against large roof falls, rather than the details of the support pattern. It was also found that a heavy steel channel can improve the safety of the system because of the 'sling' action it provides. Additionally, the analysis showed that fully-grouted rebar bolts load much earlier than the cable bolts, and pre-tensioning of the cable bolts can result in a more uniform distribution of loading in the roof.

  10. Analysis of alternatives for using cable bolts as primary support at two low-seam coal mines

    PubMed Central

    Esterhuizen, Gabriel S.; Tulu, Ihsan B.

    2016-01-01

    Cable bolts are sometimes used in low-seam coal mines to provide support in difficult ground conditions. This paper describes cable bolting solutions at two low-seam coal mines in similar ground conditions. Both mines used support systems incorporating cable bolts as part of the primary support system. Two original cable bolt based support systems as well as two modified systems are evaluated to estimate their ability to prevent large roof falls. One of the support systems incorporated passive cable bolts, while the other used pre-tensioned cable bolts. The results and experience at the mines showed that the modified systems provided improved stability over the original support systems. The presence of the cable bolts is the most important contribution to stability against large roof falls, rather than the details of the support pattern. It was also found that a heavy steel channel can improve the safety of the system because of the ‘sling’ action it provides. Additionally, the analysis showed that fully-grouted rebar bolts load much earlier than the cable bolts, and pre-tensioning of the cable bolts can result in a more uniform distribution of loading in the roof. PMID:27722019

  11. Description and mineralogy of Tertiary volcanic ash partings and their relationship to coal seams, near Homer, Alaska

    SciTech Connect

    Reinink-Smith, L.M.

    1985-04-01

    Outcrops of Tertiary coal-bearing units in sea cliffs of the Kenai Peninsula provide an excellent study area for volcanic ash partings in coals. Twenty mid-to late-Miocene, 50-cm to 3-m thick coal seams exposed in the sea cliffs about 10 km west of Homer contain an average of 10 volcanic ash or lapilli tuff partings each. The bedding relationships of the coal with any one parting cannot be predicted, and the contacts of the partings with the coal range from very sharp to predominantly gradational. These bedding relationships provide clues about the surface on which the ashes fell and on which the coal was accumulating. For example, some ashes fell in standing water, others on irregular subaerial surfaces. The partings are in various stages of alteration to kaolinite and bentonite, and vary in thickness from a few millimeters to about 10 cm. The consistency and texture of the partings depend on the degree of alteration; the less altered partings display visible pumice fragments and euhedral feldspars, commonly within a finer grained matrix. Separate pumice fragments, excluding matrix, can also occur as partings in the coal. The more altered partings may be wet and plastic, or they may be well indurated claystones; the colors range from gray-yellow to dark brown. The indurated prints are more common in older part of the section. The coal seams may be capped by volcanic ash partings and are commonly underlain by a pencil shale of nonvolcanic origin.

  12. A reactive transport modelling approach to assess the leaching potential of hydraulic fracturing fluids associated with coal seam gas extraction

    NASA Astrophysics Data System (ADS)

    Mallants, Dirk; Simunek, Jirka; Gerke, Kirill

    2015-04-01

    Coal Seam Gas production generates large volumes of "produced" water that may contain compounds originating from the use of hydraulic fracturing fluids. Such produced water also contains elevated concentrations of naturally occurring inorganic and organic compounds, and usually has a high salinity. Leaching of produced water from storage ponds may occur as a result of flooding or containment failure. Some produced water is used for irrigation of specific crops tolerant to elevated salt levels. These chemicals may potentially contaminate soil, shallow groundwater, and groundwater, as well as receiving surface waters. This paper presents an application of scenario modelling using the reactive transport model for variably-saturated media HP1 (coupled HYDRUS-1D and PHREEQC). We evaluate the fate of hydraulic fracturing chemicals and naturally occurring chemicals in soil as a result of unintentional release from storage ponds or when produced water from Coal Seam Gas operations is used in irrigation practices. We present a review of exposure pathways and relevant hydro-bio-geo-chemical processes, a collation of physico-chemical properties of organic/inorganic contaminants as input to a set of generic simulations of transport and attenuation in variably saturated soil profiles. We demonstrate the ability to model the coupled processes of flow and transport in soil of contaminants associated with hydraulic fracturing fluids and naturally occurring contaminants.

  13. A research of some problems of the exploration and exploitation of gas-bearing coal seam in Shanxi Province

    SciTech Connect

    Zhang, H.Y.; Liu Kai

    1997-12-31

    In this paper the author explores the problems concerning the formation of the Shanxi gas-bearing coal bed, its long-range analyses and the exploration and exploitation of the gas-bearing coal bed there. In the section about the formation of Shanxi gas-bearing coal bed and its long-range analyses the authors explain the following problems: coal seam thickness, the permeability of the gas-bearing coal bed, overburden, the structure fracture, the seam mechanism of shear, the geological structure location, etc. The authors point out that the middle section of Hedong Coal Field (HCF), Qingsui Coal Field (QCF) and Xishan Coal Field (XCF) are the most favorable areas. In the section on the exploration and its exploitation the authors point out the chief works in each work stage and the application of the means of exploration and the layout method of the exploration project, thus providing a reliable foundation for the reference of the gas-bearing exploration.

  14. Adaptive welding of fillet welds using a fast seam-tracking sensor in combination with a standard industrial robot

    NASA Astrophysics Data System (ADS)

    Pischetsrieder, Alexandra

    1996-08-01

    In laser welding, problems often arise from the accuracy required by the laser process, particularly where joints have narrow tolerance limits, e.g. with a fillet weld at an overlap joint. In a number of applications seam-tracking sensors can improve this situation. They are able to detect and follow the joint geometry autonomously. In addition to the tolerances, a varying gap between the parts to weld can cause welding flaws. To solve the problems caused by the height of the gap a functionality for adaptive welding can be integrated into the tracking sensor, rendering possible a determined influence on process parameters. Functional dependencies between the height of the gap and the welding parameters are presented in this paper. To further enhance the accuracy of path tracking the dynamic behavior of the system is investigated. With the integration of these dependencies into the tracking sensor, an algorithm for adaptive welding has been obtained, which takes another step towards the raise of profitability of laser installations by a simplified weld seam preparation and an enhanced stability of the welding process.

  15. Effects of national antibiotic stewardship and infection control strategies on hospital-associated and community-associated meticillin-resistant Staphylococcus aureus infections across a region of Scotland: a non-linear time-series study.

    PubMed

    Lawes, Timothy; Lopez-Lozano, José-María; Nebot, Cesar A; Macartney, Gillian; Subbarao-Sharma, Rashmi; Dare, Ceri Rj; Wares, Karen D; Gould, Ian M

    2015-12-01

    Restriction of antibiotic consumption to below predefined total use thresholds might remove the selection pressure that maintains antimicrobial resistance within populations. We assessed the effect of national antibiotic stewardship and infection prevention and control programmes on prevalence density of meticillin-resistant Staphylococcus aureus (MRSA) infections across a region of Scotland. This non-linear time-series analysis and quasi-experimental study explored ecological determinants of MRSA epidemiology among 1,289,929 hospital admissions and 455,508 adults registered in primary care in northeast Scotland. Interventions included antibiotic stewardship to restrict use of so-called 4C (cephalosporins, co-amoxiclav, clindamycin, and fluoroquinolones) and macrolide antibiotics; a hand hygiene campaign; hospital environment inspections; and MRSA admission screening. Total effects were defined as the difference between scenarios with intervention (observed) and without intervention (predicted from time-series models). The primary outcomes were prevalence density of MRSA infections per 1000 occupied bed days (OBDs) in hospitals or per 10,000 inhabitants per day (IDs) in the community. During antibiotic stewardship, use of 4C and macrolide antibiotics fell by 47% (mean decrease 224 defined daily doses [DDDs] per 1000 OBDs, 95% CI 154-305, p=0·008) in hospitals and 27% (mean decrease 2·52 DDDs per 1000 IDs, 0·65-4·55, p=0·031) in the community. Hospital prevalence densities of MRSA were inversely related to intensified infection prevention and control, but positively associated with MRSA rates in neighbouring hospitals, importation pressures, bed occupancy, and use of fluoroquinolones, co-amoxiclav, and third-generation cephalosporins, or macrolide antibiotics that exceeded hospital-specific thresholds. Community prevalence density was predicted by hospital MRSA rates and above-threshold use of macrolides, fluoroquinolones, and clindamycin. MRSA prevalence

  16. Analyses of temperature-dependent interface states, series resistances, and AC electrical conductivities of Al/p—Si and Al/Bi4Ti3O12/p—Si structures by using the admittance spectroscopy method

    NASA Astrophysics Data System (ADS)

    Mert, Yıldırım; Perihan, Durmuş; Şemsettin, Altındal

    2013-10-01

    In this study, Al/p—Si and Al/Bi4Ti3O12/p—Si structures are fabricated and their interface states (Nss), the values of series resistance (Rs), and AC electrical conductivity (σac) are obtained each as a function of temperature using admittance spectroscopy method which includes capacitance—voltage (C—V) and conductance—voltage (G—V) measurements. In addition, the effect of interfacial Bi4Ti3O12 (BTO) layer on the performance of the structure is investigated. The voltage-dependent profiles of Nss and Rs are obtained from the high-low frequency capacitance method and the Nicollian method, respectively. Experimental results show that Nss and Rs, as strong functions of temperature and applied bias voltage, each exhibit a peak, whose position shifts towards the reverse bias region, in the depletion region. Such a peak behavior is attributed to the particular distribution of Nss and the reordering and restructuring of Nss under the effect of temperature. The values of activation energy (Ea), obtained from the slope of the Arrhenius plot, of both structures are obtained to be bias voltage-independent, and the Ea of the metal-ferroelectric-semiconductor (MFS) structure is found to be half that of the metal—semiconductor (MS) structure. Furthermore, other main electrical parameters, such as carrier concentration of acceptor atoms (NA), built-in potential (Vbi), Fermi energy (EF), image force barrier lowering (Δ Φb), and barrier height (Φb), are extracted using reverse bias C-2—V characteristics as a function of temperature.

  17. A SEmi-Adiabatic Matched-phase Spin echo (SEAMS) PINS Pulse-pair for B1-insensitive Simultaneous Multi-slice Imaging

    PubMed Central

    Feldman, Rebecca E; Islam, Haisam M; Xu, Junqian; Balchandani, Priti

    2016-01-01

    Purpose Simultaneous multi-slice (SMS) imaging is a powerful technique that can reduce image acquisition time for anatomical, functional, and diffusion weighted magnetic resonance imaging. At higher magnetic fields, such as 7 Tesla, increased radiofrequency (RF) field inhomogeneity, power deposition, and changes in relaxation parameters make SMS spin echo imaging challenging. We designed an adiabatic 180° Power Independent of Number of Slices (PINS) pulse and a matched-phase 90° PINS pulse to generate a SEmi-Adiabatic Matched-phase Spin echo (SEAMS) PINS sequence to address these issues. Methods We used the adiabatic Shinnar Le-Roux (SLR) algorithm to generate a 180° pulse. The SLR polynomials for the 180° pulse were then used to create a matched-phase 90° pulse. The pulses were sub-sampled to produce a SEAMS PINS pulse-pair and the performance of this pulse-pair was validated in phantoms and in vivo. Results Simulations as well as phantom and in vivo results, demonstrate multi-slice capability and improved B1-insensitivity of the SEAMS PINS pulse-pair when operating at RF amplitudes of up to 40% above adiabatic threshold. Conclusion The SEAMS PINS approach presented here achieves multi-slice spin echo profiles with improved B1-insensitivity when compared to a conventional spin echo. PMID:25753055

  18. The C. elegans CBFbeta homolog, BRO-1, regulates the proliferation, differentiation and specification of the stem cell-like seam cell lineages.

    PubMed

    Xia, Dan; Zhang, Yuxia; Huang, Xinxin; Sun, Yinyan; Zhang, Hong

    2007-09-15

    The RUNX/CBFbeta heterodimeric transcription factor plays an important role in regulating cell proliferation and differentiation in a variety of developmental contexts. Aberrant function of Runx and CBFbeta has been causally related to the development of various diseases, including acute myeloid leukemia, gastric cancer and cleidocranial dysplasia. The underlying mechanism of the RUNX/CBFbeta complex in regulation of cell proliferation is still poorly defined. In this study, we demonstrate that the Caenorhabditis elegans CBFbeta homolog, bro-1, is essential for the proliferation, differentiation and specification of a row of stem cell-like lineages, called seam cells. BRO-1 forms complex with the C. elegans RUNX homolog, RNT-1, and augments the DNA-binding activity of RNT-1. The RNT-1/BRO-1 complex directly interacts with the C. elegans Groucho homolog, UNC-37, whose loss of function mutations display similar defects in the proliferation of seam cells as those of bro-1 and rnt-1 mutants. Additionally, the defects in seam cell division in bro-1 mutants are substantially rescued by the inactivation of the negative regulators of the G1 to S phase cell cycle progression, including the lin-35 Rb, fzr-1 Cdh1 and cki-1 CIP homologs. Our studies indicate that the transcriptional repression activity of the RNT-1/BRO-1 complex regulates the G1 to S cell cycle progression during seam cell division.

  19. The nuclear receptor NHR-25 cooperates with the Wnt/β-catenin asymmetry pathway to control differentiation of the T seam cell in C. elegans

    PubMed Central

    Hajduskova, Martina; Jindra, Marek; Herman, Michael A.; Asahina, Masako

    2009-01-01

    Summary Asymmetric cell divisions produce new cell types during animal development. Studies in Caenorhabditis elegans have identified major signal-transduction pathways that determine the polarity of cell divisions. How these relatively few conserved pathways interact and what modulates them to ensure the diversity of multiple tissue types is an open question. The Wnt/β-catenin asymmetry pathway governs polarity of the epidermal T seam cell in the C. elegans tail. Here, we show that the asymmetry of T-seam-cell division and morphogenesis of the male sensory rays require NHR-25, an evolutionarily conserved nuclear receptor. NHR-25 ensures the neural fate of the T-seam-cell descendants in cooperation with the Wnt/β-catenin asymmetry pathway. Loss of NHR-25 enhances the impact of mutated nuclear effectors of this pathway, POP-1 (TCF) and SYS-1 (β-catenin), on T-seam-cell polarity, whereas it suppresses the effect of the same mutations on asymmetric division of the somatic gonad precursor cells. Therefore, NHR-25 can either synergize with or antagonize the Wnt/β-catenin asymmetry pathway depending on the tissue context. Our findings define NHR-25 as a versatile modulator of Wnt/β-catenin-dependent cell-fate decisions. PMID:19654209

  20. Mining geology of the Pond Creek seam, Pikeville Formation, Middle Pennsylvanian, in part of the Eastern Kentucky Coal Field, USA

    USGS Publications Warehouse

    Greb, S.F.; Popp, J.T.

    1999-01-01

    The Pond Creek seam is one of the leading producers of coal in the Eastern Kentucky Coal Field. The geologic factors that affect mining were investigated in several underground mines and categorized in terms of coal thickness, coal quality, and roof control. The limits of mining and thick coal are defined by splitting along the margin of the coal body. Within the coal body, local thickness variation occurs because of (1) leader coal benches filling narrow, elongated depressions, (2) rider coal benches coming near to or merging with the main bench, (3) overthrust coal benches being included along paleochannel margins, (4) cutouts occuring beneath paleochannels, and (5) very hard and unusual rock partings occuring along narrow, elongated trends. In the study area, the coal is mostly mined as a compliance product: sulfur contents are less than 1% and ash yields are less than 10%. Local increases in sulfur occur beneath sandstones, and are inferred to represent post-depositional migration of fluids through porous sands into the coal. Run-of-mine quality is also affected by several mine-roof conditions and trends of densely concentrated rock partings, which lead to increased in- and out-of-seam dilution and overall ash content of the mined coal. Roof control is largely a function of a heterolithic facies mosaic of coastal-estuarine origin, regional fracture trends, and unloading stress related to varying mine depth beneath the surface. Lateral variability of roof facies is the rule in most mines. The largest falls occur beneath modern valleys and parallel fractures, along paleochannel margins, within tidally affected 'stackrock,' and beneath rider coals. Shale spalling, kettlebottoms, and falls within other more isolated facies also occur. Many of the lithofacies, and falls related to bedding weaknesses within or between lithofacies, occur along northeast-southwest trends, which can be projected in advance of mining. Fracture-related falls occur independently of

  1. Data base for the analysis of compositional characteristics of coal seams and macerals. Quarterly technical progress report, May-July 1980

    SciTech Connect

    Davis, Alan; Suhr, N. H.; Spackman, W.; Painter, P. C.; Walker, P. L.; Given, P. H.

    1980-10-01

    The basic objectives of this new program are, firstly, to understand the systematic relationships between the properties of coals and macerals, and, secondly, to determine the lateral and vertical variability in the properties of a single seam imposed by varying environmental conditions at the time of coal formation. Thirty-four coal samples were collected during the quarter from Pennsylvania and Illinois. To date, 54 vitrinite concentrates have been hand picked and will be studied by a range of physical and chemical techniques. One hundred and forty coal samples and 53 printouts of coal data were provided on request to the coal research community. The Lower Kittanning seam has been selected for the study of the variability in chemical, petrographic, mineralogic, fluid, and conversion properties of a single seam. A description of the structural and stratigraphic settings of the important coal seam as they relate to this investigation is given. Bivariate plots of data from the Lower Kittanning seam are presented. The fluid temperature range as measured with the Gieseler plastometer reaches a maximum at a reflectance of 1.10 to 1.15% and carbon content of 87 to 88% dmmf. Liquefaction conversion in a tubing-bomb reactor with tetralin shows a linear decrease with rank (reflectance). The problems associated with the application Fourier Transform Infrared Spectroscopy to the characterization of coal structure are critically discussed. The micropore surface areas and micropore volumes of three selected coals and a vitrinite concentrate, as measured from uptake of CO/sub 2/ at 25/sup 0/C, increased with decreasing particle size. Work on measurements of apparent densities and uptake of methanol and water is in progress.

  2. Identification of Wnt Pathway Target Genes Regulating the Division and Differentiation of Larval Seam Cells and Vulval Precursor Cells in Caenorhabditis elegans

    PubMed Central

    Gorrepati, Lakshmi; Krause, Michael W.; Chen, Weiping; Brodigan, Thomas M.; Correa-Mendez, Margarita; Eisenmann, David M.

    2015-01-01

    The evolutionarily conserved Wnt/β-catenin signaling pathway plays a fundamental role during metazoan development, regulating numerous processes including cell fate specification, cell migration, and stem cell renewal. Wnt ligand binding leads to stabilization of the transcriptional effector β-catenin and upregulation of target gene expression to mediate a cellular response. During larval development of the nematode Caenorhabditis elegans, Wnt/β-catenin pathways act in fate specification of two hypodermal cell types, the ventral vulval precursor cells (VPCs) and the lateral seam cells. Because little is known about targets of the Wnt signaling pathways acting during larval VPC and seam cell differentiation, we sought to identify genes regulated by Wnt signaling in these two hypodermal cell types. We conditionally activated Wnt signaling in larval animals and performed cell type–specific "mRNA tagging" to enrich for VPC and seam cell–specific mRNAs, and then used microarray analysis to examine gene expression compared to control animals. Two hundred thirty-nine genes activated in response to Wnt signaling were identified, and we characterized 50 genes further. The majority of these genes are expressed in seam and/or vulval lineages during normal development, and reduction of function for nine genes caused defects in the proper division, fate specification, fate execution, or differentiation of seam cells and vulval cells. Therefore, the combination of these techniques was successful at identifying potential cell type–specific Wnt pathway target genes from a small number of cells and at increasing our knowledge of the specification and behavior of these C. elegans larval hypodermal cells. PMID:26048561

  3. Early events in the photochemistry of 5-diazo Meldrum's acid: formation of a product manifold in C-N bound and pre-dissociated intersection seam regions.

    PubMed

    Li, Huijing; Migani, Annapaola; Blancafort, Lluís; Li, Quansong; Li, Zesheng

    2016-11-09

    5-Diazo Meldrum's acid (DMA) undergoes a photo-induced Wolff rearrangement (WR). Recent gas-phase experiments have identified three photochemical products formed in a sub-ps scale after irradiation, a carbene formed after nitrogen loss, a ketene formed after WR and a second carbene formed after nitrogen and CO elimination (A. Steinbacher, et al. Phys. Chem. Chem. Phys., 2014, 16, 7290-7298). In this work, ground- and excited-state potential energy surfaces (PESs) have been investigated at the MS-CASPT2//CASSCF level. The key element of the PESs is an extended S0/S1 conical intersection seam along the C-N dissociation coordinate. The C-N predissociated region of the seam is accessed after excitation to the bright S2 state, and decay paths from the seam to the three primary products have been characterized. For the ketene and carbene II products, we show two possible formation pathways, a direct and a stepwise one, which suggests that these products may be formed in a bi-modal fashion. We have also characterized two possible mechanisms for triplet formation, one occurring before C-N dissociation involving a (S1/T2/T1) crossing region, and another one through the carbene. In contrast, excitation to S1 leads to a C-N bound region of the seam from where DMA regeneration or diazirine formation is possible, with a preference for the first case. The results are in good agreement with experimental data. Together with our previous work on diazonaphthoquinone, they show the importance of an extended seam in the photochemistry of α-diazoketones.

  4. Determining the hydraulic and fracture properties of the Coal Seam Gas well by numerical modelling and GLUE analysis

    NASA Astrophysics Data System (ADS)

    Askarimarnani, Sara; Willgoose, Garry; Fityus, Stephen

    2017-04-01

    Coal seam gas (CSG) is a form of natural gas that occurs in some coal seams. Coal seams have natural fractures with dual-porosity systems and low permeability. In the CSG industry, hydraulic fracturing is applied to increase the permeability and extract the gas more efficiently from the coal seam. The industry claims that it can design fracking patterns. Whether this is true or not, the public (and regulators) requires assurance that once a well has been fracked that the fracking has occurred according to plan and that the fracked well is safe. Thus defensible post-fracking testing methodologies for gas generating wells are required. In 2009 a fracked well HB02, owned by AGL, near Broke, NSW, Australia was subjected to "traditional" water pump-testing as part of this assurance process. Interpretation with well Type Curves and simple single phase (i.e. only water, no gas) highlighted deficiencies in traditional water well approaches with a systemic deviation from the qualitative characteristic of well drawdown curves (e.g. concavity versus convexity of drawdown with time). Accordingly a multiphase (i.e. water and methane) model of the well was developed and compared with the observed data. This paper will discuss the results of this multiphase testing using the TOUGH2 model and its EOS7C constitutive model. A key objective was to test a methodology, based on GLUE monte-carlo calibration technique, to calibrate the characteristics of the frack using the well test drawdown curve. GLUE involves a sensitivity analysis of how changes in the fracture properties change the well hydraulics through and analysis of the drawdown curve and changes in the cone of depression. This was undertaken by changing the native coal, fracture, and gas parameters to see how changing those parameters changed the match between simulations and the observed well drawdown. Results from the GLUE analysis show how much information is contained in the well drawdown curve for estimating field scale

  5. Location of Two Seams in the Proximity of the C2v ππ* Minimum Energy Path of Formaldehyde.

    PubMed

    De Vico, Luca; Lindh, Roland

    2009-01-13

    Photochemical reactions rationalization is a key aspect for the understanding and setup of novel experiment and novel photoinitiated pathways. In this respect, the relationship between minimum energy paths over an excited-state and the intersection to lower potential energy surfaces is fundamental. In order to help the understanding of this relationship, in this study we present a novel kind of constraint for geometry optimizations, namely, an "orthogonality" constraint. Its possible applications are described. A complete example on how to retrieve the direct relationship between a minimum energy path over an excited-state potential energy surface and a conical intersection seam is given for C2v symmetry constrained formaldehyde. The advantages of using the novel constraint when rationalizing a (photo)chemical reaction are presented.

  6. Western Cretaceous Coal Seam Project. Final project summary. Final topical report, 1 January 1988-31 August 1989 (research)

    SciTech Connect

    Mavor, M.J.; Close, J.C.

    1989-12-31

    A summary of the Western Cretaceous Coal Seam project conclusions and data collection efforts is presented in the report. The discussion includes a summary of the geologic, formation evaluation, and stimulation analyses of four major wells. The names operators and locations of these wells are: Hamilton No. 3, Mesa Operating Limited Partnership, San Juan Co. NM, Sec. 30, Twn. 32 N, Rng. 10 W; Northeast Blanco Unit No. 403, Blackwood Nichols Co., Ltd, Rio Arriba Co. NM, Sec. 9, Twn. 30 N, Rng. 7 W; Southern Ute - Mobil 36-1, McKenzie Methane Co., LaPlata Co. CO, Sec. 36, Twn 34 N, Rng. 10 W; and Colorado 32-7 No. 9, Mobil Oil Corp., LaPlata Co, CO, Sec. 4, Twn. 32 N, Rng. 7 W. The discussion includes a summary of 7 minor well efforts in addition to the above major efforts.

  7. Characterization of the organic structure of the Lower Kittanning coal seam using Fourier transform infrared spectroscopy and optical properties

    SciTech Connect

    Kuehn, D.W.

    1983-01-01

    Variations in organic structure of coal samples of the Lower Kittanning seam were determined with Fourier transform infared spectroscopy (FTIR) and reflectance at different wavelengths of visible light. FTIR is a relatively new method for obtaining quantitative data for the organic constituents of coal. The system not only provides spectra of greater quality than conventional infared spectroscopy, but it is coupled to an on-line minicomputer which allows the user to analyze data and perform a variety of manipulations. The data for vitrinite concentrates were compared with selected chemical data using bivariate and multivariate statistical techniques. Certain spectral bands showed high correlations with conventional rank parameters in bivariate analysis. Multivariate analysis revealed that some bands showed dependency on a given rank parameter while others were independent. Reflectance and refractive index showed dependency on each other whereas the absorption index appeared to be partially independent. Absorptive index also was independent of the data from FTIR analysis. Liquefaction data and Gieseler fluidity were included with FTIR data for the channel samples in bivariate and multivariate analyses. The analyses revealed that two infrared bands, aliphatic CH/sub 2/ at 2853 cm/sup -1/ and aromatic stretch between 3100 and 2990 cm/sup -1/ can best predict the liquefaction conversion and temperature of maximum fluidity of the Lower Kittanning seam samples. The areal variability in the distribution of FTIR and petrographic data was contoured, and revealed that environment of deposition was a primary control in the distribution of aliphatic groups and petrographic constituents, whereas rank determined the distribution of aromatic CH groups.

  8. Phagocytosis by Acanthamoeba castellanii: ionic strength dependence of the probability of cell attachment; ingestion and contact seam morphology.

    PubMed

    Obaray, N; Coakley, W T.

    2001-10-01

    The phagocytosis of glutaraldehyde-fixed horse erythrocytes by Acanthamoeba castellanii has been examined in iso-osmolal phosphate buffered saline/sucrose suspending phases of ionic strength, I, ranging from 0.17 to 0.0017. The erythrocytes were exposed, at a ratio of 15:1, to 5x10(6) amoeba in 0.2 ml volumes. The average number of erythrocytes forming a contact with an amoeba over 30 min (T(30)) was well described by T(30)=5.2 exp(-0.112xI(-0.5)). The index of the exponential 'probability of attachment' term may also be expressed in terms of either surface potential (psi(0)) or the Debye length (kappa(-1)). The probability term is formally similar to a Bolzmann factor. Electron microscopy showed that contact spreading of the amoeba over the erythrocyte took place by formation of discrete contacts and that the lateral separation distance between contacts was 0.66, 1.36 and 1.59 &mgr;m for ionic strengths 0.17, 0.052 and 0.0017, respectively. The direction of change in lateral contact separation distance was consistent with published changes in focal contact separation when amoeba move over glass or when human erythrocyte-erythrocyte adhesion occurs in different ionic strength media. The direction was also consistent with interfacial instability theory predictions for the dependence of localised membrane contact formation on interaction potential. The proportion of attached cells that were subsequently ingested correlated more strongly with the number of contacts formed along the cell-cell contact region (seam) than with the seam length at different ionic strengths.

  9. The Outburst Risk as a Function of the Methane Capacity and Firmness of a Coal Seam

    NASA Astrophysics Data System (ADS)

    Wierzbicki, Mirosław; Skoczylas, Norbert

    2014-12-01

    In most coal basins that are currently being exploited, gas and rock outbursts pose a considerable safety threat. The risk of their occurrence is frequently assessed by means of a parameter known as the methane capacity of coal. In a lot of countries, the evaluation of the mechanical properties of coal is conducted by means of another parameter: the firmness of coal. Due to the laboratory investigations and in situ observations carried out by the authors of this paper, it was possible to determine a function space in which the outburst risk can be described as a function of the methane capacity and firmness of a coal seam. This, in turn, made it possible to link the "gas factor" to the "mechanical factor", and thus provide a more comprehensive risk analysis. Wyrzuty gazów i skał stanowią duże zagrożenie w większości obecnie eksploatowanych zagłębi węglowych. Bardzo często wykorzystywanym parametrem oceny stanu zagrożenia wyrzutowego jest zawartość metanu w węglu. W wielu krajach do oceny mechanicznych parametrów węgla wykorzystuje się zwięzłość. Autorzy przeprowadzili badania laboratoryjne polegające na prowokacjach wyrzutów w skali laboratoryjnej. Jako materiał badawczy wykorzystane zostały brykiety węglowe. W trakcie badań wstępnych ustalona została zależność pomiędzy porowatością brykietów, a ich zwięzłością f oraz pomiędzy ciśnieniem nasycania metanem, a wskaźnikiem intensywności desorpcji dP. Pozwoliło to na przygotowywanie eksperymentów o kontrolowanych parametrach gazowych (wskaźnik intensywności desorpcji) oraz wytrzymałościowych (zwięzłość). Opracowana została metoda kontrolowania intensywności prowokacji wyrzutu poprzez określenie tempa spadku ciśnienia gazu przed czołem brykietu. Dzięki temu dla siatki parametrów f-dP możliwe było poszukiwanie minimalnej, skutecznej intensywności prowokacji wyrzutu. Znormalizowana wartość stałej czasowej spadku ciśnienia przed czołem brykietu powoduj

  10. Final Technical Report for CENTRIA's EnergyPeak Building Integrated Photovoltaics ( BIPV ) for Standing Seam Metal Roofing Project (DE-FG36-08GO88131)

    SciTech Connect

    Mowrey, Rick

    2010-07-31

    Architects have said they will adopt Solar Roofs when they are integrated into roofing systems, building design, plans and specifications, and bidding procedures . Standing Seam Metal Roof manufacturers will answer these architects needs if someone will establish standards, pre-design systems, write specifications, tests systems, meet codes, etc. Energypeak was developed to provide the above so Architects can specify BIPV Standing Seam Roof Systems and Manufacturers can brand, market, sell, manufacture and deliver these systems. EnergyPeak took on the challenge to design BIPV modules using current PV technology, design electrical components, develop wire management systems, test, meet codes, write cad drawings and specifications, commercialize and deliver complete standards to the Industry.

  11. Time-Lapse Analysis of Methane Quantity in the Mary Lee Group of Coal Seams Using Filter-Based Multiple-Point Geostatistical Simulation.

    PubMed

    Karacan, C Özgen; Olea, Ricardo A

    2013-08-01

    Coal seam degasification and its success are important for controlling methane, and thus for the health and safety of coal miners. During the course of degasification, properties of coal seams change. Thus, the changes in coal reservoir conditions and in-place gas content as well as methane emission potential into mines should be evaluated by examining time-dependent changes and the presence of major heterogeneities and geological discontinuities in the field. In this work, time-lapsed reservoir and fluid storage properties of the New Castle coal seam, Mary Lee/Blue Creek seam, and Jagger seam of Black Warrior Basin, Alabama, were determined from gas and water production history matching and production forecasting of vertical degasification wellbores. These properties were combined with isotherm and other important data to compute gas-in-place (GIP) and its change with time at borehole locations. Time-lapsed training images (TIs) of GIP and GIP difference corresponding to each coal and date were generated by using these point-wise data and Voronoi decomposition on the TI grid, which included faults as discontinuities for expansion of Voronoi regions. Filter-based multiple-point geostatistical simulations, which were preferred in this study due to anisotropies and discontinuities in the area, were used to predict time-lapsed GIP distributions within the study area. Performed simulations were used for mapping spatial time-lapsed methane quantities as well as their uncertainties within the study area. The systematic approach presented in this paper is the first time in literature that history matching, TIs of GIPs and filter simulations are used for degasification performance evaluation and for assessing GIP for mining safety. Results from this study showed that using production history matching of coalbed methane wells to determine time-lapsed reservoir data could be used to compute spatial GIP and representative GIP TIs generated through Voronoi decomposition

  12. An application of enhanced 3D-CAD methods with integrated geometry creation algorithms for PVC-seams in automotive body in white design

    NASA Astrophysics Data System (ADS)

    Frener, Gernot; Thum, Katharina; Hirz, Mario; Harrich, Alexander

    2012-06-01

    State of the art automotive development processes are based on virtual product models, which include a digital representation of complete vehicle geometry and structures. Increasing computation performance and continuously growing demands on virtual development processes lead to the application of precise product representation within common CAD software packages. A specific challenge represents the creation of PVC-seams, which are used for corrosion protection of sheet metal components in automotive body in white design. Besides the high requirements of accurate geometric modeling in digital representation, modern development processes call for an increasing level of design automation. To fit both, the present approach introduces a method for an automatic generation of PVC-seams using the functionalities of commercial CAD software. [Figure not available: see fulltext.

  13. Modeling and interpretation of two-phase flow and tracer studies from a subbituminous coal seam in the San Juan basin of New Mexico

    SciTech Connect

    Nuttall, H.E.; Travis, B.J.

    1980-01-01

    Field and modeling studies were performed to characterize two-phase flow within the natural cleat structure of an upper Cretaceous subbituminous coal seam. A two borehole pattern with open completion was used in a study of dewatering and tracer residence time distribution. Air was pumped into a five meter thick seam located about 170 meters below the surface. Krypton 85 was used as the airborne tracer. Air inflow and air and water production rates and tracer arrival times were monitored. The field tests were simulated with a two-phase, three component, porous flow code. Results showed that the air inflow and air and water outflow rates and breakthrough times could not be modeled assuming a uniform darcy-type permeability. The use of a pressure dependent permeability did provide, however, a much better match with the field data.

  14. JV Task 109 - Risk Assessment and Feasibility of Remedial Alternatives for Coal Seam at Garrison, North Dakota

    SciTech Connect

    Jarda Solc

    2008-01-01

    The Energy & Environmental Research Center (EERC) conducted an evaluation of alternative technologies for remediation of hydrocarbon-contaminated coal seam, including impacted soils and groundwater in Garrison, North Dakota. Geotechnical characteristics of the impacted fractured coal seam provide for rapid off-site contaminant transport, with the currently identified impacted zone covering an area of about 40 acres. Regardless of the exposure mechanism (free, dissolved, or vapor phase), results of laboratory tests confirmed secondary release of gasoline-based compounds from contaminated coal to water reaching concentrations documented from the impacted areas. Coal laboratory tests confirmed low risks associated with spontaneous ignition of gasoline-contaminated coal. High contaminant recovery efficiency for the vacuum-enhanced recovery pilot tests conducted at three selected locations confirmed its feasibility for full-scale remediation. A total of 3500 gallons (13.3 m{sup 3}) of contaminated groundwater and over 430,000 ft{sup 3} (12,200 m{sup 3}) of soil vapor were extracted during vacuum-enhanced recovery testing conducted July 17-24, 2007, resulting in the removal of about 1330 lb (603 kg) of hydrocarbons, an equivalent of about 213 gallons of product. The summary of project activities is as follows: (1) Groundwater and vapor monitoring for existing wells, including domestic wells, conducted on a monthly basis from December 12, 2006, to June 6, 2007. This monitoring activity conducted prior to initiation of the EERC field investigation was requested by NDDH in a letter dated December 1, 2006. (2) Drilling of 20 soil borings, including installation of extraction and monitoring wells conducted April 30-May 4 and May 14-18, 2007. (3) Groundwater sampling and water-table monitoring conducted June 11-13, 2007. (4) Evaluation of the feasibility of using a camera survey for delineation of mining voids conducted May 16 and September 10-11, 2007. (5) Survey of all wells

  15. Environmental impact of coal mining and coal seam gas production on surface water quality in the Sydney basin, Australia.

    PubMed

    Ali, A; Strezov, V; Davies, P; Wright, I

    2017-08-01

    The extraction of coal and coal seam gas (CSG) will generate produced water that, if not adequately treated, will pollute surface and groundwater systems. In Australia, the discharge of produced water from coal mining and related activities is regulated by the state environment agency through a pollution licence. This licence sets the discharge limits for a range of analytes to protect the environment into which the produced water is discharged. This study reports on the impact of produced water from coal mine activities located within or discharging into high conservation environments, such as National Parks, in the outer region of Sydney, Australia. The water samples upstream and downstream from the discharge points from six mines were taken, and 110 parameters were tested. The results were assessed against a water quality index (WQI) which accounts for pH, turbidity, dissolved oxygen, biochemical oxygen demand, total dissolved solids, total phosphorus, nitrate nitrogen and E .coli. The water quality assessment based on the trace metal contents against various national maximum admissible concentration (MAC) and their corresponding environmental impacts was also included in the study which also established a base value of water quality for further study. The study revealed that impacted water downstream of the mine discharge points contained higher metal content than the upstream reference locations. In many cases, the downstream water was above the Australia and New Zealand Environment Conservation Council and international water quality guidelines for freshwater stream. The major outliers to the guidelines were aluminium (Al), iron (Fe), manganese (Mn), nickel (Ni) and zinc (Zn). The WQI of surface water at and downstream of the discharge point was lower when compared to upstream or reference conditions in the majority of cases. Toxicology indices of metals present in industrial discharges were used as an additional tool to assess water quality, and the newly

  16. Novel pre-treatment of zeolite materials for the removal of sodium ions: potential materials for coal seam gas co-produced wastewater.

    PubMed

    Santiago, Oscar; Walsh, Kerry; Kele, Ben; Gardner, Edward; Chapman, James

    2016-01-01

    Coal seam gas (CSG) is the extraction of methane gas that is desorbed from the coal seam and brought to the surface using a dewatering and depressurisation process within the saturated coalbed. The extracted water is often referred to as co-produced CSG water. In this study, co-produced water from the coal seam of the Bowen Basin (QLD, Australia) was characterised by high concentration levels of Na(+) (1156 mg/L), low concentrations of Ca(2+) (28.3 mg/L) and Mg(2+) (5.6 mg/L), high levels of salinity, which are expected to cause various environmental problems if released to land or waters. The potential treatment of co-produced water using locally sourced natural ion exchange (zeolite) material was assessed. The zeolite material was characterized for elemental composition and crystal structure. Natural, untreated zeolite demonstrated a capacity to adsorb Na(+) ions of 16.16 mEq/100 g, while a treated zeolite using NH4 (+) using a 1.0 M ammonium acetate (NH4C2H3O2) solution demonstrated an improved 136 % Na(+) capacity value of 38.28 mEq/100 g after 720 min of adsorption time. The theoretical exchange capacity of the natural zeolite was found to be 154 mEq/100 g. Reaction kinetics and diffusion models were used to determine the kinetic and diffusion parameters. Treated zeolite using a NH4 (+) pre-treatment represents an effective treatment to reduce Na(+) concentration in coal seam gas co-produced waters, supported by the measured and modelled kinetic rates and capacity.

  17. Spindle assembly checkpoint genes reveal distinct as well as overlapping expression that implicates MDF-2/Mad2 in postembryonic seam cell proliferation in Caenorhabditis elegans.

    PubMed

    Tarailo-Graovac, Maja; Wang, Jun; Chu, Jeffrey S C; Tu, Domena; Baillie, David L; Chen, Nansheng

    2010-09-21

    The spindle assembly checkpoint (SAC) delays anaphase onset by inhibiting the activity of the anaphase promoting complex/cyclosome (APC/C) until all of the kinetochores have properly attached to the spindle. The importance of SAC genes for genome stability is well established; however, the roles these genes play, during postembryonic development of a multicellular organism, remain largely unexplored. We have used GFP fusions of 5' upstream intergenic regulatory sequences to assay spatiotemporal expression patterns of eight conserved genes implicated in the spindle assembly checkpoint function in Caenorhabditis elegans. We have shown that regulatory sequences for all of the SAC genes drive ubiquitous GFP expression during early embryonic development. However, postembryonic spatial analysis revealed distinct, tissue-specific expression of SAC genes with striking co-expression in seam cells, as well as in the gut. Additionally, we show that the absence of MDF-2/Mad2 (one of the checkpoint genes) leads to aberrant number and alignment of seam cell nuclei, defects mainly attributed to abnormal postembryonic cell proliferation. Furthermore, we show that these defects are completely rescued by fzy-1(h1983)/CDC20, suggesting that regulation of the APC/CCDC20 by the SAC component MDF-2 is important for proper postembryonic cell proliferation. Our results indicate that SAC genes display different tissue-specific expression patterns during postembryonic development in C. elegans with significant co-expression in hypodermal seam cells and gut cells, suggesting that these genes have distinct as well as overlapping roles in postembryonic development that may or may not be related to their established roles in mitosis. Furthermore, we provide evidence, by monitoring seam cell lineage, that one of the checkpoint genes is required for proper postembryonic cell proliferation. Importantly, our research provides the first evidence that postembryonic cell division is more sensitive to

  18. Spindle assembly checkpoint genes reveal distinct as well as overlapping expression that implicates MDF-2/Mad2 in postembryonic seam cell proliferation in Caenorhabditis elegans

    PubMed Central

    2010-01-01

    Background The spindle assembly checkpoint (SAC) delays anaphase onset by inhibiting the activity of the anaphase promoting complex/cyclosome (APC/C) until all of the kinetochores have properly attached to the spindle. The importance of SAC genes for genome stability is well established; however, the roles these genes play, during postembryonic development of a multicellular organism, remain largely unexplored. Results We have used GFP fusions of 5' upstream intergenic regulatory sequences to assay spatiotemporal expression patterns of eight conserved genes implicated in the spindle assembly checkpoint function in Caenorhabditis elegans. We have shown that regulatory sequences for all of the SAC genes drive ubiquitous GFP expression during early embryonic development. However, postembryonic spatial analysis revealed distinct, tissue-specific expression of SAC genes with striking co-expression in seam cells, as well as in the gut. Additionally, we show that the absence of MDF-2/Mad2 (one of the checkpoint genes) leads to aberrant number and alignment of seam cell nuclei, defects mainly attributed to abnormal postembryonic cell proliferation. Furthermore, we show that these defects are completely rescued by fzy-1(h1983)/CDC20, suggesting that regulation of the APC/CCDC20 by the SAC component MDF-2 is important for proper postembryonic cell proliferation. Conclusion Our results indicate that SAC genes display different tissue-specific expression patterns during postembryonic development in C. elegans with significant co-expression in hypodermal seam cells and gut cells, suggesting that these genes have distinct as well as overlapping roles in postembryonic development that may or may not be related to their established roles in mitosis. Furthermore, we provide evidence, by monitoring seam cell lineage, that one of the checkpoint genes is required for proper postembryonic cell proliferation. Importantly, our research provides the first evidence that postembryonic cell

  19. Draft Genome Sequence of Cellulosilyticum sp. I15G10I2, a Novel Bacterium Isolated from a Coal Seam Gas Water Treatment Pond

    PubMed Central

    Adelskov, Joseph

    2017-01-01

    ABSTRACT Cellulosilyticum sp. strain I15G10I2 was isolated from a coal seam gas water treatment pond at the Spring Gully water treatment facility, Roma, Queensland, Australia. Analysis of the genome of 4,489,861 bp and G+C content of 35.23% revealed that strain I15G10I2 shared limited similarity to members of the genus Cellulosilyticum, family Lachnospiraceae. PMID:28209824

  20. Development and psychometric evaluation of the Self-efficacy for Appropriate Medication Use Scale (SEAMS) in low-literacy patients with chronic disease.

    PubMed

    Risser, Jessica; Jacobson, Terry A; Kripalani, Sunil

    2007-01-01

    Medication nonadherence remains a significant obstacle to achieving improved health outcomes in patients with chronic disease. Self-efficacy, the confidence in one's ability to perform a given task such as taking one's medications, is an important determinant of medication adherence, indicating the need for reliable and valid tools for measuring this construct. This study sought to develop a self-efficacy scale for medication adherence in chronic disease management that can be used in patients with a broad range of literacy skills. The Self-efficacy for Appropriate Medication Use (SEAMS) was developed by a multidisciplinary team with expertise in medication adherence and health literacy. Its psychometric properties were evaluated among 436 patients with coronary heart disease and other comorbid conditions. Reliability was evaluated by measuring internal consistency and test-retest reliability. Principal component factor analysis was performed to evaluate the validity of the SEAMS. Reliability and validity analyses were also performed separately among patients with low and higher literacy levels. The final 13-item scale had good internal consistency reliability (Cronbach's alpha = 0.89). A two-factor solution was found, explaining 52.3% of the scale's variance. The scale performed similarly across literacy levels. The SEAMS is a reliable and valid instrument that may provide a valuable assessment of medication self-efficacy in chronic disease management, and appears appropriate for use in patients with low literacy skills.

  1. Time-lapse analysis of methane quantity in Mary Lee group of coal seams using filter-based multiple-point geostatistical simulation

    USGS Publications Warehouse

    Karacan, C. Özgen; Olea, Ricardo A.

    2013-01-01

    The systematic approach presented in this paper is the first time in literature that history matching, TIs of GIPs and filter simulations are used for degasification performance evaluation and for assessing GIP for mining safety. Results from this study showed that using production history matching of coalbed methane wells to determine time-lapsed reservoir data could be used to compute spatial GIP and representative GIP TIs generated through Voronoi decomposition. Furthermore, performing filter simulations using point-wise data and TIs could be used to predict methane quantity in coal seams subjected to degasification. During the course of the study, it was shown that the material balance of gas produced by wellbores and the GIP reductions in coal seams predicted using filter simulations compared very well, showing the success of filter simulations for continuous variables in this case study. Quantitative results from filter simulations of GIP within the studied area briefly showed that GIP was reduced from an initial ∼73 Bcf (median) to ∼46 Bcf (2011), representing a 37 % decrease and varying spatially through degasification. It is forecasted that there will be an additional ∼2 Bcf reduction in methane quantity between 2011 and 2015. This study and presented results showed that the applied methodology and utilized techniques can be used to map GIP and its change within coal seams after degasification, which can further be used for ventilation design for methane control in coal mines.

  2. Block Slides on Extremely Weak Tectonic Clay Seams in Openly Folded Tertiary Mud-Rocks at Auckland and the Rangitikei Valley, North Island, New Zealand

    NASA Astrophysics Data System (ADS)

    Prebble, Warwick M.; Williams, Ann L.

    2016-06-01

    Block slides have developed on extremely weak, thin clay seams of tectonic origin, parallel to bedding in gently dipping sandstones and mudstones of Tertiary age. Two areas of noted instability are investigated at Auckland and the Rangitikei valley. Dimensions range from 100 m across × 100 m long for short displacement block slides up to 4 km across × 3 km long for large landslide complexes in which block slides are a major component. Displacements of blocks range from incipient (cm) through short (30 m) to 2 or 3 km for large slides. Many of the Auckland slides are dormant but likely to move in a 2000 year return period earthquake or 100 year high intensity rain storm. At Rangitikei there are many active, younger slides. Sliding rates for active failures vary from a few cm/year to 50 m in 30 min. Host rocks are weak to very weak clayey sandstones and sandy mudstones. The seams are rich in smectite. They have polished and crushed walls, may have slickensides and some contain rounded rock fragments. Laboratory shear strength of the seams is 13 kPa cohesion and 13° friction, with a lower bound of 8° at zero cohesion. Strength is increased at the field scale by waviness, steps and splays. Continuity can be demonstrated over distances of hundreds of metres. Key investigation methods were mapping, shafts and trenches. Tectonic uplift, folding and faulting of the weak Tertiary strata and river down-cutting are perpetuating block slide development.

  3. Use Of Lasers In Seam Welding Of Engine Parts For Cars

    NASA Astrophysics Data System (ADS)

    Luttke, A.

    1986-11-01

    The decision in favour of active research into laser technology was taken in our company in 1978. In the following years we started with the setting-up of a laser laboratory charged with the task of performing basic manufacturing technology experiments in order to examine the ap-plications of laser technology for cutting, welding, hardening, remelting and secondary alloys. The first laboratory-laser - a 2,5 kW fast axial flow CO2 laser - is connected with a CNC-controlled workpiece manipulation unit, which is designed in such a way that workpieces from the smallest component of a car gearbox up to crankcases for commercial vehicles can be manipulated at speeds considered theoretically feasible for laser machining. The use of the laser beam for cutting, hardening and welding tasks has been under investigation in our company, in this laboratory for some 6 years. Laser cutting is now no longer a question of development, but is instead standard practice and is already used in various sec-tions of our production division for pilot-series manufacturing and for small batches. Laser hardening has, in our opinion, great possibilities for tasks which, for distortion and accessibility reasons, cannot be satisfactorily performed using present-day processes, for instance induction hardening. However, a great deal of development work is still necessary before economically reasonable and quality-assured production installation can be undertaken. Laser-welding is now used in series-production in our company for two engine components. More details are given below.

  4. Unification and Infinite Series

    ERIC Educational Resources Information Center

    Leyendekkers, J. V.; Shannon, A. G.

    2008-01-01

    Some infinite series are analysed on the basis of the hypergeometric function and integer structure and modular rings. The resulting generalized functions are compared with differentiation of the "mother" series. (Contains 1 table.)

  5. Gel retarder for fire prevention and extinguishing -- Its application for spontaneous combustion of coal seams

    SciTech Connect

    1998-12-31

    With its unique function, gel retarder has been successfully applied to extinguish fire at coal face, roadways and stop line of upper slice extraction, and a comparably perfect set of fire extinguishing techniques has been developed. The technique gathers together characteristics of water-fixation, leak-blocking, cooling, oxidation-retarding and heat-resisting. A new agglomerating agent without amine and corrosion has been developed to replace amine-salt and acid used in the past. Gel-injection technology cooperating with the grouting system on the ground solves previous problems in which gel-injection velocity was slow and materials transport was difficult. The technique has become the main measure to extinguish spontaneous combustion in coal mines in China. The use of gel retarder as an important means of underground fire prevention will be applied more widely to prevent and extinguish spontaneous fire in coal mines.

  6. Geometric Series via Probability

    ERIC Educational Resources Information Center

    Tesman, Barry

    2012-01-01

    Infinite series is a challenging topic in the undergraduate mathematics curriculum for many students. In fact, there is a vast literature in mathematics education research on convergence issues. One of the most important types of infinite series is the geometric series. Their beauty lies in the fact that they can be evaluated explicitly and that…

  7. Enrichment of Radon and Carbon Dioxide in the Open Atmosphere of an Australian Coal Seam Gas Field

    PubMed Central

    2013-01-01

    Atmospheric radon (222Rn) and carbon dioxide (CO2) concentrations were used to gain insight into fugitive emissions in an Australian coal seam gas (CSG) field (Surat Basin, Tara region, Queensland). 222Rn and CO2 concentrations were observed for 24 h within and outside the gas field. Both 222Rn and CO2 concentrations followed a diurnal cycle with night time concentrations higher than day time concentrations. Average CO2 concentrations over the 24-h period ranged from ∼390 ppm at the control site to ∼467 ppm near the center of the gas field. A ∼3 fold increase in maximum 222Rn concentration was observed inside the gas field compared to outside of it. There was a significant relationship between maximum and average 222Rn concentrations and the number of gas wells within a 3 km radius of the sampling sites (n = 5 stations; p < 0.05). A positive trend was observed between CO2 concentrations and the number of CSG wells, but the relationship was not statistically significant. We hypothesize that the radon relationship was a response to enhanced emissions within the gas field related to both point (well heads, pipelines, etc.) and diffuse soil sources. Radon may be useful in monitoring enhanced soil gas fluxes to the atmosphere due to changes in the geological structure associated with wells and hydraulic fracturing in CSG fields. PMID:23444905

  8. Analysis and mapping of post-fire hydrologic hazards for the 2002 Hayman, Coal Seam, and Missionary Ridge wildfires, Colorado

    USGS Publications Warehouse

    Elliott, J.G.; Smith, M.E.; Friedel, M.J.; Stevens, M.R.; Bossong, C.R.; Litke, D.W.; Parker, R.S.; Costello, C.; Wagner, J.; Char, S.J.; Bauer, M.A.; Wilds, S.R.

    2005-01-01

    Wildfires caused extreme changes in the hydrologic, hydraulic, and geomorphologic characteristics of many Colorado drainage basins in the summer of 2002. Detailed assessments were made of the short-term effects of three wildfires on burned and adjacent unburned parts of drainage basins. These were the Hayman, Coal Seam, and Missionary Ridge wildfires. Longer term runoff characteristics that reflect post-fire drainage basin recovery expected to develop over a period of several years also were analyzed for two affected stream reaches: the South Platte River between Deckers and Trumbull, and Mitchell Creek in Glenwood Springs. The 10-, 50-, 100-, and 500-year flood-plain boundaries and water-surface profiles were computed in a detailed hydraulic study of the Deckers-to-Trumbull reach. The Hayman wildfire burned approximately 138,000 acres (216 square miles) in granitic terrain near Denver, and the predominant potential hazard in this area is flooding by sediment-laden water along the large tributaries to and the main stem of the South Platte River. The Coal Seam wildfire burned approximately 12,200 acres (19.1 square miles) near Glenwood Springs, and the Missionary Ridge wildfire burned approximately 70,500 acres (110 square miles) near Durango, both in areas underlain by marine shales where the predominant potential hazard is debris-flow inundation of low-lying areas. Hydrographs and peak discharges for pre-burn and post-burn scenarios were computed for each drainage basin and tributary subbasin by using rainfall-runoff models because streamflow data for most tributary subbasins were not available. An objective rainfall-runoff model calibration method based on nonlinear regression and referred to as the ?objective calibration method? was developed and applied to rainfall-runoff models for three burned areas. The HEC-1 rainfall-runoff model was used to simulate the pre-burn rainfall-runoff processes in response to the 100-year storm, and HEC-HMS was used for runoff

  9. Assessing Connectivity Between an Overlying Aquifer and a Coal Seam Gas Resource Using Methane Isotopes, Dissolved Organic Carbon and Tritium

    NASA Astrophysics Data System (ADS)

    Iverach, Charlotte P.; Cendón, Dioni I.; Hankin, Stuart I.; Lowry, David; Fisher, Rebecca E.; France, James L.; Nisbet, Euan G.; Baker, Andy; Kelly, Bryce F. J.

    2015-11-01

    Coal seam gas (CSG) production can have an impact on groundwater quality and quantity in adjacent or overlying aquifers. To assess this impact we need to determine the background groundwater chemistry and to map geological pathways of hydraulic connectivity between aquifers. In south-east Queensland (Qld), Australia, a globally important CSG exploration and production province, we mapped hydraulic connectivity between the Walloon Coal Measures (WCM, the target formation for gas production) and the overlying Condamine River Alluvial Aquifer (CRAA), using groundwater methane (CH4) concentration and isotopic composition (δ13C-CH4), groundwater tritium (3H) and dissolved organic carbon (DOC) concentration. A continuous mobile CH4 survey adjacent to CSG developments was used to determine the source signature of CH4 derived from the WCM. Trends in groundwater δ13C-CH4 versus CH4 concentration, in association with DOC concentration and 3H analysis, identify locations where CH4 in the groundwater of the CRAA most likely originates from the WCM. The methodology is widely applicable in unconventional gas development regions worldwide for providing an early indicator of geological pathways of hydraulic connectivity.

  10. Assessing Connectivity Between an Overlying Aquifer and a Coal Seam Gas Resource Using Methane Isotopes, Dissolved Organic Carbon and Tritium

    PubMed Central

    Iverach, Charlotte P.; Cendón, Dioni I.; Hankin, Stuart I.; Lowry, David; Fisher, Rebecca E.; France, James L.; Nisbet, Euan G.; Baker, Andy; Kelly, Bryce F. J.

    2015-01-01

    Coal seam gas (CSG) production can have an impact on groundwater quality and quantity in adjacent or overlying aquifers. To assess this impact we need to determine the background groundwater chemistry and to map geological pathways of hydraulic connectivity between aquifers. In south-east Queensland (Qld), Australia, a globally important CSG exploration and production province, we mapped hydraulic connectivity between the Walloon Coal Measures (WCM, the target formation for gas production) and the overlying Condamine River Alluvial Aquifer (CRAA), using groundwater methane (CH4) concentration and isotopic composition (δ13C-CH4), groundwater tritium (3H) and dissolved organic carbon (DOC) concentration. A continuous mobile CH4 survey adjacent to CSG developments was used to determine the source signature of CH4 derived from the WCM. Trends in groundwater δ13C-CH4 versus CH4 concentration, in association with DOC concentration and 3H analysis, identify locations where CH4 in the groundwater of the CRAA most likely originates from the WCM. The methodology is widely applicable in unconventional gas development regions worldwide for providing an early indicator of geological pathways of hydraulic connectivity. PMID:26530701

  11. Assessment of potential debris-flow peak discharges from basins burned by the 2002 Coal Seam fire, Colorado

    USGS Publications Warehouse

    Cannon, Susan H.; Michael, John A.; Gartner, Joseph E.

    2003-01-01

    These maps present the results of assessments of peak discharges that can potentially be generated by debris flows issuing from the basins burned by the Coal Seam fire of June and July 2002, near Glenwood Springs, Colorado. The maps are based on a regression model for debris-flow peak discharge normalized by average storm intensity as a function of basin gradient and burned extent, and limited field checking. A range of potential peak discharges that could potentially be produced from each of the burned basins between 1 ft3/s (0.03 m3/s) and greater than 5,000 ft3/s (>141 m3/s) is calculated for the 5-year, 1-hour storm of 0.80 inches (20 mm). The 25-year, 1-hour storm of 1.3 inches (33 mm). The 100- year, 1-hour storm of 1.8 inches (46 mm) produced peak discharges between 1 and greater than 8,000 ft3/s (>227 m3/s). These maps are intended for use by emergency personnel to aid in the preliminary design of mitigation measures, and the planning of evacuation timing and routes.

  12. Rapid Qualitative Risk Assessment for Contaminant Leakage From Coal Seams During Underground Coal Gasification and CO2 Injection

    SciTech Connect

    Friedmann, S J

    2004-07-02

    One of the major risks associated with underground coal gasification is contamination of local aquifers with a variety of toxic compounds. It is likely that the rate, volume, extent, and concentrations of contaminant plumes will depend on the local permeability field near the point of gasification. This field depends heavily on the geological history of stratigraphic deposition and the specifics of stratigraphic succession. Some coals are thick and isolated, whereas others are thinner and more regionally expressed. Some coals are overlain by impermeable units, such as marine or lacustrine shales, whereas others are overlain by permeable zones associated with deltaic or fluvial successions. Rapid stratigraphic characterization of the succession provides first order information as to the general risk of contaminant escape, which provides a means of ranking coal contaminant risks by their depositional context. This risk categorization could also be used for ranking the relative risk of CO{sub 2} escape from injected coal seams. Further work is needed to verify accuracy and provide some quantification of risks.

  13. Enrichment of radon and carbon dioxide in the open atmosphere of an Australian coal seam gas field.

    PubMed

    Tait, Douglas R; Santos, Isaac R; Maher, Damien T; Cyronak, Tyler J; Davis, Rachael J

    2013-04-02

    Atmospheric radon ((222)Rn) and carbon dioxide (CO2) concentrations were used to gain insight into fugitive emissions in an Australian coal seam gas (CSG) field (Surat Basin, Tara region, Queensland). (222)Rn and CO2 concentrations were observed for 24 h within and outside the gas field. Both (222)Rn and CO2 concentrations followed a diurnal cycle with night time concentrations higher than day time concentrations. Average CO2 concentrations over the 24-h period ranged from ~390 ppm at the control site to ~467 ppm near the center of the gas field. A ~3 fold increase in maximum (222)Rn concentration was observed inside the gas field compared to outside of it. There was a significant relationship between maximum and average (222)Rn concentrations and the number of gas wells within a 3 km radius of the sampling sites (n = 5 stations; p < 0.05). A positive trend was observed between CO2 concentrations and the number of CSG wells, but the relationship was not statistically significant. We hypothesize that the radon relationship was a response to enhanced emissions within the gas field related to both point (well heads, pipelines, etc.) and diffuse soil sources. Radon may be useful in monitoring enhanced soil gas fluxes to the atmosphere due to changes in the geological structure associated with wells and hydraulic fracturing in CSG fields.

  14. Module Thirteen: Series AC RLC Circuits and Resonance; Basic Electricity and Electronics Individualized Learning System.

    ERIC Educational Resources Information Center

    Bureau of Naval Personnel, Washington, DC.

    In this module the student will combine RL (resistive-inductance) and RC (resistive-capacitive) circuits and learn some of the phenomena which result. The module is divided into four lessons: solving RLC (resistive-inductance-capacitive) circuits, resonant frequency in series circuits, conditions of series resonance, and experiments with series…

  15. Resistance-resistant antibiotics.

    PubMed

    Oldfield, Eric; Feng, Xinxin

    2014-12-01

    New antibiotics are needed because drug resistance is increasing while the introduction of new antibiotics is decreasing. We discuss here six possible approaches to develop 'resistance-resistant' antibiotics. First, multitarget inhibitors in which a single compound inhibits more than one target may be easier to develop than conventional combination therapies with two new drugs. Second, inhibiting multiple targets in the same metabolic pathway is expected to be an effective strategy owing to synergy. Third, discovering multiple-target inhibitors should be possible by using sequential virtual screening. Fourth, repurposing existing drugs can lead to combinations of multitarget therapeutics. Fifth, targets need not be proteins. Sixth, inhibiting virulence factor formation and boosting innate immunity may also lead to decreased susceptibility to resistance. Although it is not possible to eliminate resistance, the approaches reviewed here offer several possibilities for reducing the effects of mutations and, in some cases, suggest that sensitivity to existing antibiotics may be restored in otherwise drug-resistant organisms.

  16. Module Five: Relationships of Current, Voltage, and Resistance; Basic Electricity and Electronics Individualized Learning System.

    ERIC Educational Resources Information Center

    Bureau of Naval Personnel, Washington, DC.

    This module covers the relationships between current and voltage; resistance in a series circuit; how to determine the values of current, voltage, resistance, and power in resistive series circuits; the effects of source internal resistance; and an introduction to the troubleshooting of series circuits. This module is divided into five lessons:…

  17. Cell shunt resistance and photovoltaic module performance

    SciTech Connect

    McMahon, T.J.; Basso, T.S.; Rummel, S.R.

    1996-09-01

    Shunt resistance of cells in photovoltaic modules can affect module power output and could indicate flawed manufacturing processes and reliability problems. The authors describe a two-terminal diagnostic method to directly measure the shunt resistance of individual cells in a series-connected module non-intrusively, without deencapsulation. Peak power efficiency vs. light intensity was measured on a 12-cell, series-connected, single crystalline module having relatively high cell shunt resistances. The module was remeasured with 0.5-, 1-, and 2-ohm resistors attached across each cell to simulate shunt resistances of several emerging technologies. Peak power efficiencies decreased dramatically at lower light levels. Using the PSpice circuit simulator, they verified that cell shunt and series resistances can indeed be responsible for the observed peak power efficiency vs. intensity behavior. They discuss the effect of basic cell diode parameters, i.e., shunt resistance, series resistance, and recombination losses, on PV module performance as a function of light intensity.

  18. Series Transmission Line Transformer

    DOEpatents

    Buckles, Robert A.; Booth, Rex; Yen, Boris T.

    2004-06-29

    A series transmission line transformer is set forth which includes two or more of impedance matched sets of at least two transmissions lines such as shielded cables, connected in parallel at one end ans series at the other in a cascading fashion. The cables are wound about a magnetic core. The series transmission line transformer (STLT) which can provide for higher impedance ratios and bandwidths, which is scalable, and which is of simpler design and construction.

  19. Fourier Series Operating Package

    NASA Technical Reports Server (NTRS)

    Charnow, Milton L.

    1961-01-01

    This report presents a computer program for multiplying, adding, differentiating, integrating, "barring" and scalarly multiplying "literal" Fourier series as such, and for extracting the coefficients of specified terms.

  20. Antimicrobial Resistance

    MedlinePlus

    ... spread of antimicrobial resistance. Present situation Resistance in bacteria Antibiotic resistance is present in every country. Patients with infections caused by drug-resistant bacteria are at increased risk of worse clinical outcomes ...