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Sample records for cavernoso hepatico roto

  1. 3M heavy duty roto peen: Baseline report

    SciTech Connect

    1997-07-31

    The heavy-duty roto peen technology was being evaluated at Florida International University (FIU) as a baseline technology. It is a commercially available technology and has been used for various projects at locations throughout the country. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the human factors assessment for safety and health issues. The heavy-duty roto peen allows for the selective removal of concrete substrates. The peen is a tungsten carbide shot brazed to a hardened steel rivet that is supported by a heavy-duty flexible flap. The shot rivet is kept captive to the tool by mounting the roto peen in a slotted hub. The heavy-duty roto peen is designed to be used with several commercially available pieces of equipment. The equipment being used will determine the width of each pass. The equipment being used with the roto peen is then connected to a vacuum system for dust collection during scabbling. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  2. 3M heavy duty roto peen: Baseline report; Greenbook (chapter)

    SciTech Connect

    1997-07-31

    The heavy-duty roto peen technology is being evaluated at Florida International University (FIU) as a baseline technology. It is a commercially available technology and has been used for various projects at locations throughout the country. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the human factors assessment for safety and health issues. The heavy-duty roto peen allows for the selective removal of concrete substrates. The peen is a tungsten carbide shot brazed to a hardened steel rivet that is supported by a heavy-duty flexible flap. The shot rivet is kept captive to the tool by mounting the roto peen in a slotted hub. The heavy-duty roto peen is designed to be used with several commercially available pieces of equipment. The equipment being used will determine the width of each pass. The equipment being used with the roto peen is then connected to a vacuum system for dust collection during scabbling. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  3. [Manometric study of two Roux-en-Y hepatico-jejunostomy].

    PubMed

    Peillon, C; Ducrotte, P; Duhamel, C; Denis, P; Testart, J

    1990-01-01

    The aim of this study was to describe (during the fasting state in two patients the motor activity of the limb in Roux-en-Y hepatico-jejunostomy). In the two patients, the limb was created 15 years and 15 days prior to the study respectively. Recordings were performed with a low compliance pneumohydraulic system below the jejuno-jejunal anastomosis then in the limb. Motor studies in the limb were coupled with recordings carried out in the duodenum. In both patients, the regular occurrence of a typical phase III (PIII) activity was demonstrated in the limb whereas no retrograde or abnormal motor patterns were found. PIIIs in the limb were uncoordinated with duodenal PIIIs. Trimebutine, given intravenously, induced a typical PIII activity in the duodenum and the limb simultaneously. Spontaneous or trimebutine-induced PIIIs in the limb had a slower migration velocity (p less than 0.01) than duodenal PIIIs. Lastly, we were unable to record PIIIs in the distal jejunum below the jejuno-jejunal anastomosis despite the lack of associated abnormal motor patterns. This study demonstrates that a normally propagated PIII activity can be observed in the limb in Roux-en-Y hepatico-jejunostomy immediately or several years after the surgical procedure. PMID:2270917

  4. 3M heavy duty roto peen: Baseline report; Summary

    SciTech Connect

    1997-07-31

    The roto peen scaler allows for the selective removal of concrete substrates. The peen is a tungsten carbide shot brazed to a hardened steel rivet that is supported by a heavy duty flexible flap. The peens are coupled with a commercially available piece of equipment that is used to scabble or remove the concrete. The scabbled debris is then collected into 55 gallon drums by means of a vacuum system. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  5. Oddi sphincter preserved cholangioplasty with hepatico-subcutaneous stoma for hepatolithiasis

    PubMed Central

    Lian, Yu-Gui; Zhang, Wei-Tao; Xu, Zhi; Ling, Xiao-Feng; Wang, Li-Xin; Hou, Chun-Sheng; Wang, Gang; Cui, Long; Zhou, Xiao-Si

    2015-01-01

    AIM: To evaluate the long-term outcomes of Oddi sphincter preserved cholangioplasty with hepatico-subcutaneous stoma (OSPCHS) and risk factors for recurrence in hepatolithiasis. METHODS: From March 1993 to December 2012, 202 consecutive patients with hepatolithiasis underwent OSPCHS at our department. The Oddi sphincter preserved procedure consisted of common hepatic duct exploration, stone extraction, hilar bile duct plasty, establishment of subcutaneous stoma to the bile duct. Patients with recurrent stones can undergo stone extraction and/or biliary drainage via the subcutaneous stoma which can be incised under local anesthesia. The long-term results were reviewed. Cox regression model was employed to analyze the risk factors for stone recurrence. RESULTS: Ninety-seven (48.0%) OSPCHS patients underwent hepatic resection concomitantly. The rate of surgical complications was 10.4%. There was no perioperative death. The immediate stone clearance rate was 72.8%. Postoperative cholangioscopic lithotomy raised the clearance rate to 97.0%. With a median follow-up period of 78.5 mo (range: 2-233 mo), 24.8% of patients had recurrent stones, 2.5% had late development of cholangiocarcinoma, and the mortality rate was 5.4%. Removal of recurrent stones and/or drainage of inflammatory bile via subcutaneous stoma were conducted in 44 (21.8%) patients. The clearance rate of recurrent stones was 84.0% after subsequent choledochoscopic lithotripsy via subcutaneous stoma. Cox regression analysis showed that residual stone was an independent prognostic factor for stone recurrence. CONCLUSION: In selected patients with hepatolithiasis, OSPCHS achieves excellent long-term outcomes, and residual stone is an independent prognostic factor for stone recurrence. PMID:26668511

  6. ROTO PEEN Scalar and VAC-PAC{reg_sign} system

    SciTech Connect

    1998-02-01

    The Pentek, Inc., milling technology, comprising the ROTO PEEN Scaler and the VAC-PAC{reg_sign} waste collection system, is a fully developed and commercialized technology used to remove hazardous coatings from concrete and steel floors, walls, ceilings, and structural components. This report describes a demonstration of the Pentek, Inc., milling system to remove the paint coating from 650 ft{sup 2} of concrete flooring on the service floor of the Chicago Pile-5 (CP-5) Research Reactor. CP-5 is a heavy-water moderated and cooled, highly enriched, uranium-fueled thermal reactor designed to supply neutrons for research. The reactor had a thermal-power rating of 5 megawatts and was operated continuously for 25 years until its final shutdown in 1979. These 25 years of operation produced activation and contamination characteristics representative of other nuclear facilities within the Department of Energy (DOE) complex and the commercial nuclear sector. CP-5 contains many of the essential features of other DOE and commercial nuclear facilities and can be used safely as a demonstration facility for the evaluation of innovative technologies for the future D and D of much larger, more highly contaminated facilities.

  7. Roto-translational states of the interstitial molecular hydrogen in silicon: A theoretical study

    SciTech Connect

    Melnikov, Vladlen V.; Yurchenko, Sergei N.

    2015-10-28

    A theoretical study of the interstitial molecular hydrogen in the silicon single-crystal is reported. H{sub 2} and Si have been approximated as a rigid object and a static matrix, respectively. A five-dimensional numerical-analytical representation of an ab initio potential energy surface of the system has been constructed. This representation has been used to calculate rotational, translational, and roto-translational energy levels of the interstitial hydrogen, where three levels of theory, 2D, 3D, and 5D were considered. The potential energy surface, the band structure of energy levels, and the roto-translational states obtained are presented together with the symmetry analysis of the roto-translational wavefunctions.

  8. Guidance and Control Design for High-Speed Rollout and Turnoff (ROTO)

    NASA Technical Reports Server (NTRS)

    Goldthorpe, S. H.; Dangaran, R. D.; Dwyer, J. P.; McBee, L. S.; Norman, R. M.; Shannon, J. H.; Summers, L. G.

    1996-01-01

    A ROTO architecture, braking and steering control law and display designs for a research high speed Rollout and Turnoff (ROTO) system applicable to transport class aircraft are described herein. Minimum surface friction and FMS database requirements are also documented. The control law designs were developed with the aid of a non-real time simulation program incorporating airframe and gear dynamics as well as steering and braking guidance algorithms. An attainable objective of this ROTO system, as seen from the results of this study, is to assure that the studied aircraft can land with runway occupancy times less then 53 seconds. Runway occupancy time is measured from the time the aircraft crosses the runway threshold until its wing tip clears the near side of the runway. Turnoff ground speeds of 70 knots onto 30 degree exits are allowed with dry and wet surface conditions. Simulation time history and statistical data are documented herein. Parameters which were treated as variables in the simulation study include aircraft touchdown weight/speed/location, aircraft CG, runway friction, sensor noise and winds. After further design and development of the ROTO control system beyond the system developed earlier, aft CG MD-11 aircraft no longer require auto-asymmetric braking (steering) and fly-by-wire nose gear steering. However, the auto ROTO nose gear hysteresis must be less than 2 degrees. The 2 sigma dispersion certified for MD-11 CATIIIB is acceptable. Using this longitudinal dispersion, three ROTO exits are recommended at 3300, 4950 and 6750 feet past the runway threshold. The 3300 foot exit is required for MD-81 class aircraft. Designs documented in this report are valid for the assumptions/models used in this simulation. It is believed that the results will apply to the general class of transport aircraft; however further effort is required to validate this assumption for the general case.

  9. Guidance and control requirements for high-speed Rollout and Turnoff (ROTO)

    NASA Technical Reports Server (NTRS)

    Goldthorpe, Steve H.; Kernik, Alan C.; Mcbee, Larry S.; Preston, Orv W.

    1995-01-01

    This report defines the initial requirements for designing a research high-speed rollout and turnoff (ROTO) guidance and control system applicable to transport class aircraft whose purpose is to reduce the average runway occupancy time (ROT) for aircraft operations. The requirements will be used to develop a ROTO system for both automatic and manual piloted operation under normal and reduced visibility conditions. Requirements were determined for nose wheel/rudder steering, braking/reverse thrust, and the navigation system with the aid of a non-real time, three degree-of-freedom MD-11 simulation program incorporating airframe and gear dynamics. The requirements were developed for speeds up to 70 knots using 30 ft exit geometries under dry and wet surface conditions. The requirements were generated under the assumptions that the aircraft landing system meets the current Category III touchdown dispersion requirements and that aircraft interarrival spacing is 2 nautical miles. This effort determined that auto-asymmetric braking is needed to assist steering for aft center-of-gravity aircraft. This report shows various time-history plots of the aircraft performance for the ROTO operation. This effort also investigated the state-of-the-art in the measurement of the runway coefficient of friction for various runway conditions.

  10. Dielectric elastomer based active layer for macro-scaled industrial application in roto-flexographic printing

    NASA Astrophysics Data System (ADS)

    Pinto, F.; D'Oriano, G.; Meo, M.

    2014-03-01

    The use of dielectric elastomer (DE) for the realisation of new generation actuators has attracted the interest of many researchers in the last ten years due to their high efficiency, a very good electromechanical coupling and large achievable strains [1-3]. Although these properties constitute a very important advantage, the industrial exploitation of such systems is hindered by the high voltages required for the actuation [4] that could potentially constitute also a risk for the operators. In this work we present a DE based active layer that can be used in different macro-scaled parts of industrial equipment for roto-flexographic printing substituting traditional mechanical devices, reducing manufacturing costs and enhancing its reliability. Moreover, the specific configuration of the system requires the driving voltage to be applied only in the mounting/dismounting step thus lowering further the operative costs without posing any threat for the workers. Starting from the industrial requirements, a complete thermo-mechanical characterisation using DSC and DMA was undertaken on acrylic elastomer films in order to investigate their behaviour under the operative frequencies and solicitations. Validation of the active layer was experimentally evaluated by manufacturing a DE actuator controlling both prestrain and nature of the complaint electrodes, and measuring the electrically induced Maxwell's strain using a laser vibrometer to evaluate the relative displacement along the z-axis.

  11. Design and testing of a roto-translational shutter mechanism for planetary operation

    NASA Astrophysics Data System (ADS)

    Scaccabarozzi, Diego; Saggin, Bortolino; Alberti, Edoardo

    2014-01-01

    This work describes the design and testing of a shutter mechanism for a miniaturized infrared spectrometer developed for the ESA ExoMars Pasteur mission. Unlike most usual cover mechanisms, the conceived one provides a roto-translational motion. This feature allows the sealing of the interferometer main entrance window from dust contamination, in addition to the usual function of shuttering the instrument field of view. Although this characteristic is strongly desired because it avoids dust deposition and optics contamination while the instrument is not operating, it makes the mechanism design significantly more complex. Moreover, challenging design constraints were faced: the mass budget allowed for no more than 30 g allocation, the expected working thermal range extended down to -80 °C and high vibration levels with an acceleration peak of 670 m/s2 were predicted during Mars landing. To complete the picture, the mechanism cover was required to provide also a calibration target for the 2-25 μm spectral range of the spectrometer. The resulting system is made by a calibrating/shutter cover moved by a purposely designed out of plane cams system which provides the desired motion. A mechanism mockup was assembled and successfully tested in the predicted thermal and mechanical environments.

  12. Sensitivity of Runway Occupancy Time (ROT) to Various Rollout and Turnoff (ROTO) Factors. Volume 1

    NASA Technical Reports Server (NTRS)

    Goldthorpe, S. H.

    1997-01-01

    The Terminal Area Productivity (TAP) research program was initiated by NASA to increase the airport capacity for transport aircraft operations. One element of the research program is called Low Visibility Landing and Surface Operations (LVLASO). A goal of the LVLASO research is to develop transport aircraft technologies which reduce Runway Occupancy Time (ROT) so that it does not become the limiting factor in the terminal area operations that determine the capacity of a runway. Under LVLASO, the objective of this study was to determine the sensitivity of ROT to various factors associated with the Rollout and Turnoff (ROTO) operation for transport aircraft. The following operational factors were studied and are listed in the order of decreasing ROT sensitivity: ice/flood runway surface condition, exit entrance ground speed, number of exits, high-speed exit locations and spacing, aircraft type, touchdown ground speed standard deviation, reverse thrust and braking method, accurate exit prediction capability, maximum reverse thrust availability, spiral-arc vs. circle-arc exit geometry, dry/slush/wet/snow runway surface condition, maximum allowed deceleration, auto asymmetric braking on exit, do not stow reverse thrust before the exit, touchdown longitudinal location standard deviation, flap setting, anti-skid efficiency, crosswind conditions, stopping on the exit and touchdown lateral offset.

  13. Differential-drag-based roto-translational control for propellant-less spacecraft

    NASA Astrophysics Data System (ADS)

    Pastorelli, Mirko; Bevilacqua, Riccardo; Pastorelli, Stefano

    2015-09-01

    This paper proposes a novel technique to perform propellant-free chaser-target spacecraft relative maneuvers while simultaneously stabilizing the chaser's attitude with respect to the local vertical local horizontal coordinate system centered at its body center of mass. The control forces required for relative maneuvers at low Earth orbits can be generated by varying the relative aerodynamic drag via maneuverable sails placed in the back-end of the spacecraft. At the same time, aerodynamic torques resulting from the displacement of the centers of pressure of the sails can stabilize the orientation of the spacecraft. In this work, the target vehicle is assumed to maneuver an identical sail in a cooperative fashion and will be centered and attitude-stabilized in its local vertical local horizontal coordinate system. The proposed approach is based on the idea of virtual thrusters, emulating the sail's center of pressure offset in the controller. Several test cases are presented for various existing spacecraft, demonstrating successful propellant-less roto-translational control of the chaser spacecraft.

  14. Hydrogeology characterization of roto-translational slides in flysch rock masses

    NASA Astrophysics Data System (ADS)

    Ronchetti, F.; Borgatti, L.; Cervi, F.; Corsini, A.; Piccinini, L.; Vincenzi, V.; Truffelli, G.

    2009-04-01

    The hydrogeological characteristics of roto-traslational slides in flysch are complex, due to the inherent anisotropy and heterogeneity of such rock masses. The paper deals with the hydrogeological characterization of a reactivated roto-translational slide affecting Cretaceous flysch, located in the Northern Apennines of Italy. In situ permeability and pumping test, continuous monitoring of groundwater levels, hydrochemical and isotope analyses, and finally uranine tracers were the adopted prospecting methods. The landslide sector classified as rock slide extends for about 0.5 km2 and is characterized by a marked active sliding surface at 40 m depth. Borehole cores showed an upper 10-20 m landslide layer made of clayey debris, and a lower 20 m landslide layer made of highly fractured sandstone-rich flysch. Below sliding surface the flysch is much less fractured and it is overlying a clayey mélange. The hydraulic conductivity of both layers of the rock slide body was estimated with more than ten borehole permeability tests and by 5 slug-tests in open-pipe piezometers. Results highlighted a variability of permeability at different depths and locations, between 10-6 to 10-8 m/s, linked to fracturing of rock masses and to clay fraction. Groundwater levels were monitored for more than 3 years by means of transducers in 5 standpipe piezometers, fissured above or below the sliding surface. Results showed that two overlaying aquifers exist at the slope scale: an unconfined one, in the fractured flysch of the rock slide; a confined one, in the undisturbed flysch below sliding surface. Pore pressure in the unconfined aquifer is controlled by rainfall, with fluctuation of several meters occurring hours or days from onset of precipitation. On the contrary, pore pressure in the confined aquifer shows little response to precipitation events, has fluctuations of few meters related to seasonal trends, and maintains pressure head higher than that in the unconfined one. This makes

  15. Shaping ability of Mity Roto 360 degrees and Naviflex rotary nickel-titanium instruments in simulated root canals. Part 2.

    PubMed

    Thompson, S A; Dummer, P M

    1998-02-01

    The aim of this study was to determine the shaping ability of Mity Roto 360 degrees and Naviflex rotary nickel-titanium instruments in simulated canals. Forty simulated root canals made up of four different shapes in terms of angle and position of curvature were prepared by both sets of instruments using a stepdown approach. This study describes the efficacy of the instruments in terms of prevalence of canal aberrations, the amount and direction of canal transportation, and thus the overall postoperative shape. Pre- and postoperative images of the canals were taken using a videocamera attached to a computer with image analysis software. The pre- and postoperative views were superimposed to highlight the amount and position of material removed during preparation. Neither Mity Roto 360 degrees nor Naviflex instruments created any zips or elbows. Ledges were produced in 20 (50%) canals prepared with Mity instruments and in 29 (72%) canals prepared with Naviflex instruments. Statistically significant differences (p < 0.001) between canal shapes occurred in relation to the incidence of ledges with 40 degrees canals (35) associated with more aberrations than 20 degrees canals (14); the position of the beginning of the curve had no effect. The distance of ledges from the end point of preparation was also affected significantly (p < 0.01) by canal shape. Neither instrument created any perforations or danger zones. At specific positions along the canal length, canal shape had a significant influence on total width and the amount of material removed from the inner and outer aspects of the canal curve. The direction of canal transportation at the end point of preparation was most frequently toward the outer aspect of the curve in canals prepared with Naviflex instruments, whereas the Mity instruments produced a more balanced preparation. At the apex and beginning of the curve, transportation with both instruments was generally toward the outer aspect of the curve. Overall

  16. Sensitivity of Runway Occupancy Time (ROT) to Various Rollout and Turnoff (ROTO) Factors. Volume 2; Complete Set of Plotted Data

    NASA Technical Reports Server (NTRS)

    Goldthorpe, S. H.

    1997-01-01

    The Terminal Area Productivity (TAP) research program was initiated by NASA to increase the airport capacity for transport aircraft operations. One element of the research program is called Low Visibility Landing and Surface Operations (LVLASO). A goal of the LVLASO research is to develop transport aircraft technologies which reduce Runway Occupancy Time (ROT) so that it does not become the limiting factor in the terminal area operations that determine the capacity of a runway. Under LVLASO, the objective of this study was to determine the sensitivity of ROT to various factors associated with the Rollout and Turnoff (ROTO) operation for transport aircraft. The following operational factors were studied and are listed in the order of decreasing ROT sensitivity: ice/flood runway surface condition, exit entrance ground speed, number of exits, high-speed exit locations and spacing, aircraft type, touchdown ground speed standard deviation, reverse thrust and braking method, accurate exit prediction capability, maximum reverse thrust availability, spiral-arc vs. circle-arc exit geometry, dry/slush/wet/snow runway surface condition, maximum allowed deceleration, auto asymmetric braking on exit, do not stow reverse thrust before the exit, touchdown longitudinal location standard deviation, flap setting, anti-skid efficiency, crosswind conditions, stopping on the exit and touchdown lateral offset.

  17. Rollout and Turnoff (ROTO) Guidance and Information Displays: Effect on Runway Occupancy Time in Simulated Low-Visibility Landings

    NASA Technical Reports Server (NTRS)

    Hueschen, Richard M.; Hankins, Walter W., III; Barker, L. Keith

    2001-01-01

    This report examines a rollout and turnoff (ROTO) system for reducing the runway occupancy time for transport aircraft in low-visibility weather. Simulator runs were made to evaluate the system that includes a head-up display (HUD) to show the pilot a graphical overlay of the runway along with guidance and steering information to a chosen exit. Fourteen pilots (airline, corporate jet, and research pilots) collectively flew a total of 560 rollout and turnoff runs using all eight runways at Hartsfield Atlanta International Airport. The runs consisted of 280 runs for each of two runway visual ranges (RVRs) (300 and 1200 ft). For each visual range, half the runs were conducted with the HUD information and half without. For the runs conducted with the HUD information, the runway occupancy times were lower and more consistent. The effect was more pronounced as visibility decreased. For the 1200-ft visibility, the runway occupancy times were 13% lower with HUD information (46.1 versus 52.8 sec). Similarly, for the 300-ft visibility, the times were 28% lower (45.4 versus 63.0 sec). Also, for the runs with HUD information, 78% (RVR 1200) and 75% (RVR 300) had runway occupancy times less than 50 sec, versus 41 and 20%, respectively, without HUD information.

  18. Abnormal difference between the mobilities of left- and right-twisted conformations of C6H12N2 roto-symmetrical molecules at very low temperatures.

    PubMed

    Gabuda, S P; Kozlova, S G

    2015-06-21

    We report an abnormal difference of low-temperature mobility of left-twisted and right-twisted conformations of roto symmetric molecules C6H12N2 (dabco) located in the same positions in crystal Zn2(C8H4O4)2⋅C6H12N2. The difference between (1)H NMR (Nuclear Magnetic Resonance) spin-relaxation data for left-twisted and right-twisted molecules reaches ∼3 × 10(3) times at 8 K and tends to grow at lower temperatures. We argue that taking into account four-component relativistic Dirac wave functions in the vicinity of the nodal plane of dabco molecules and vacuum fluctuations due to virtual particle-antiparticle pairs can explain the changes which C6H12N2 conformations undergo at low temperatures. PMID:26093554

  19. On the roto-translatory internal motions of a three layer non-isobarycentric Earth model: a Lagrangian system approach

    NASA Astrophysics Data System (ADS)

    Escapa, Alberto; Fukushima, Toshio

    2010-05-01

    of this relative motion, three characteristic proper modes appear: one in the direction of the figure axis (polar mode) and two orthogonal to it (equatorial modes). These modes are usually referred as Slichter triplet. In the case of the polar mode, Busse (1974) determined analytically its expression in an implicit way; later other authors have obtained by numerical methods the values of all the modes (e.g Rieutord 2002). These expressions differ substantially from the single degenerate mode existing for a non-rotating model, the differences arising from the roto-traslatory coupling of the system. To construct an analytical description of the motion of this non-isobarycentric Earth model we have approximated it by a Lagrangian system, inspired in the successful of this variational approach to tackle the rotational dynamics of isobarycentric Earth models (e.g. Moritz 1982, Getino and Ferrándiz 2001). In this way, the fluid flow is represented as the sum of a rigid motion part plus a potential motion part. In this way, the resulting dynamical system is described by means of nine generalized co-ordinates. Once constructed the kinetic energy of each layer of the Earth model and the potential energy due to the gravitational interaction of the spherical rigid inner core with the fluid, we form the Euler-Lagrange equations of the system which turn out to be non-linear. By assuming a small departure with respect to the steady rotation configuration we linearice the differential equations of the motion, deriving from them the analytical expressions of the Slichter triplet. These expressions are compared with the existing numerical ones, appearing some discrepancies between both approaches. They might be caused by neglecting the non-linear terms in the resolution of the equations or by an incomplete description of the fluid flow. However, the numerical values of the modes derived with this treatment show a great improvement with respect to the values obtained from performing

  20. On the roto-translatory internal motions of a three layer non-isobarycentric Earth model: a Lagrangian system approach

    NASA Astrophysics Data System (ADS)

    Escapa, Alberto; Fukushima, Toshio

    2010-05-01

    of this relative motion, three characteristic proper modes appear: one in the direction of the figure axis (polar mode) and two orthogonal to it (equatorial modes). These modes are usually referred as Slichter triplet. In the case of the polar mode, Busse (1974) determined analytically its expression in an implicit way; later other authors have obtained by numerical methods the values of all the modes (e.g Rieutord 2002). These expressions differ substantially from the single degenerate mode existing for a non-rotating model, the differences arising from the roto-traslatory coupling of the system. To construct an analytical description of the motion of this non-isobarycentric Earth model we have approximated it by a Lagrangian system, inspired in the successful of this variational approach to tackle the rotational dynamics of isobarycentric Earth models (e.g. Moritz 1982, Getino and Ferrándiz 2001). In this way, the fluid flow is represented as the sum of a rigid motion part plus a potential motion part. In this way, the resulting dynamical system is described by means of nine generalized co-ordinates. Once constructed the kinetic energy of each layer of the Earth model and the potential energy due to the gravitational interaction of the spherical rigid inner core with the fluid, we form the Euler-Lagrange equations of the system which turn out to be non-linear. By assuming a small departure with respect to the steady rotation configuration we linearice the differential equations of the motion, deriving from them the analytical expressions of the Slichter triplet. These expressions are compared with the existing numerical ones, appearing some discrepancies between both approaches. They might be caused by neglecting the non-linear terms in the resolution of the equations or by an incomplete description of the fluid flow. However, the numerical values of the modes derived with this treatment show a great improvement with respect to the values obtained from performing

  1. Roto-Translational Collision-Induced Absorption of CO 2for the Atmosphere of Venus at Frequencies from 0 to 250 cm -1, at Temperatures from 200 to 800 K

    NASA Astrophysics Data System (ADS)

    Gruszka, Marcin; Borysow, Aleksandra

    1997-09-01

    The collision-induced absorption of gaseous CO2is the primary source of far-infrared opacity of the atmosphere of Venus. At the temperatures and densities of the venusian atmosphere, the absorption is due mainly to binary collisions of CO2molecules. Using a realistic anisotropic intermolecular potential and assuming the absorbing dipole to be due to the electrostatic induction and a quantum overlap, a series of molecular dynamics simulations were performed for the temperature range 200 to 800 K, and the roto-translational collision-induced absorption spectra at frequencies from 0 to 250 cm-1were derived. The absorption coefficient in the submillimeter region, used in constituency retrieval studies, decreases more than 10 times in the temperature range 200 to 800 K. On the other hand, the absorption coefficient at 800 K and at the frequency range above 150 cm-1was found to be almost 10 times higher than at 200 K. Earlier works relied on experimental RT CIA data at a fixed temperature of 300 K. The new, temperature-dependent absorption bands may, when included in the analysis of the atmospheric radiative transfer of the planet, help explain the observed high far-infrared opacity of the lower layers of the atmosphere. To make the results of the simulations readily available for atmospheric abundance and radiative transfer analysis, an analytic model of the roto-translational collision-induced absorption spectral profile, applicable from 200 to 800 K, is being proposed here. The FORTRAN computer code of this newly developed model is available from the authors on request.

  2. Roto-Translational Collision-Induced Absorption of CO2 for the Atmosphere of Venus at Frequencies from 0 to 250 cm(exp -1), at Temperatures from 200 to 800 K

    NASA Technical Reports Server (NTRS)

    Gruszka, Marcin; Borysow, Aleksandra

    1997-01-01

    The collision-induced absorption (CIA)of gaseous CO2 is the primary source of far-infrared opacity of the atmosphere of Venus. At the temperatures and densities of the venusian atmosphere, the absorption is due mainly to binary collisions of CO2 molecules. Using a realistic anisotropic intermolecular potential and assuming the absorbing dipole to be due to the electrostatic induction and a quantum overlap, a series of molecular dynamics simulations were performed for the temperature range 200 to 800 K, and the roto-translational (RT) collision-induced absorption spectra at frequencies from 0 to 250 cm(exp -1) were derived. The absorption coefficient in the submillimeter region, used in constituency retrieval studies, decreases more than 10 times in the temperature range 200 to 800 K. On the other hand, the absorption coefficient at 800 K and at the frequency range above 150 cm(exp -1) was found to be almost 10 times higher than at 200 K. Earlier works relied on experimental RT CIA data at a fixed temperature of 300 K. The new, temperature-dependent absorption bands may, when included in the analysis of the atmospheric radiative transfer of the planet, help explain the observed high far-infrared opacity of the lower layers of the atmosphere. To make the results of the simulations readily available for atmospheric abundance and radiative transfer analysis, an analytic model of the roto-translational collision-induced absorption spectral profile, applicable from 200 to 800 K, is being proposed here. The FORTRAN computer code of this newly developed model is available from the authors on request.

  3. Abnormal difference between the mobilities of left- and right-twisted conformations of C{sub 6}H{sub 12}N{sub 2} roto-symmetrical molecules at very low temperatures

    SciTech Connect

    Gabuda, S. P.; Kozlova, S. G.

    2015-06-21

    We report an abnormal difference of low-temperature mobility of left-twisted and right-twisted conformations of roto symmetric molecules C{sub 6}H{sub 12}N{sub 2} (dabco) located in the same positions in crystal Zn{sub 2}(C{sub 8}H{sub 4}O{sub 4}){sub 2}⋅C{sub 6}H{sub 12}N{sub 2}. The difference between {sup 1}H NMR (Nuclear Magnetic Resonance) spin-relaxation data for left-twisted and right-twisted molecules reaches ∼3 × 10{sup 3} times at 8 K and tends to grow at lower temperatures. We argue that taking into account four-component relativistic Dirac wave functions in the vicinity of the nodal plane of dabco molecules and vacuum fluctuations due to virtual particle-antiparticle pairs can explain the changes which C{sub 6}H{sub 12}N{sub 2} conformations undergo at low temperatures.

  4. Speed Profiles for Deceleration Guidance During Rollout and Turnoff (ROTO)

    NASA Technical Reports Server (NTRS)

    Barker, L. Keith; Hankins, Walter W., III; Hueschen, Richard M.

    1999-01-01

    Two NASA goals are to enhance airport safety and to improve capacity in all weather conditions. This paper contributes to these goals by examining speed guidance profiles to aid a pilot in decelerating along the runway to an exit. A speed profile essentially tells the pilot what the airplane's speed should be as a function of where the airplane is on the runway. While it is important to get off the runway as soon as possible (when striving to minimize runway occupancy time), the deceleration along a speed profile should be constrained by passenger comfort. Several speed profiles are examined with respect to their maximum decelerations and times to reach exit speed. One profile varies speed linearly with distance; another has constant deceleration; and two related nonlinear profiles delay maximum deceleration (braking) to reduce time spent on the runway.

  5. Optimizing the turbo-roto-compound (TRC) engine. Final report

    SciTech Connect

    Abraham, J.

    1994-08-15

    Results of multidimensional computations of sprays in a very high pressure constant volume chamber are presented in two parts. Comparisons of computed and measured penetrations of non-vaporizing and vaporizing sprays are presented. A broad range of density ratios (0.005 to 0.243) is covered. It is shown that, provided sufficient numerical resolution is used, the model can adequately reproduce the measurements. Scaling laws for time and distance derived in a previous publication are found to apply also to the sprays over the broad range of density ratios considered. A combustion sub-model that has been used in spark-ignition engines, stratified-charge engines and Diesel engines is included in the model. The combustion sub-model represents low-temperature autoignition and high temperature heat release. Comparisons of computed and measured penetrations of combusting sprays and computed and measured chamber pressures are being made. In this report, only preliminary indicative comparisons of computed and measured chamber pressures for three cases are presented. Agreement of pressures within 5% is shown. The work is ongoing and a detailed report will be presented later.

  6. Arterialised hepatic nodules in the Fontan circulation: hepatico-cardiac interactions.

    PubMed

    Bryant, Timothy; Ahmad, Zaheer; Millward-Sadler, Harry; Burney, Kashif; Stedman, Brian; Kendall, Tim; Vettukattil, Joseph; Haw, Marcus; Salmon, Anthony P; Cope, Richard; Hacking, Nigel; Breen, David; Sheron, Nick; Veldtman, Gruschen R

    2011-09-15

    Hypervascular nodules occur commonly when there is hepatic venous outlet obstruction. Their nature and determinants in the Fontan circulation is poorly understood. We reviewed the records of 27 consecutive Fontan patients who had computerized tomography scan (CT) over a 4 year period for arterialised nodules and alterations in hepatic flow patterns during contrast enhanced CT scans and related these findings to cardiac characteristics. Mean patient age was 24 ± 5.8 years, (range 16.7-39.8) and mean Fontan duration was 16.8 ± 4.8 years (range 7.3-28.7). Twenty-two patients demonstrated a reticular pattern of enhancement, 4 a zonal pattern and only 1 demonstrated normal enhancement pattern. Seven (26%) patients had a median of 4 (range 1-22) arterialised nodules, mean size 1.8 cm (range 0.5 to 3.2 cm). All nodules were located in the liver periphery, their outer aspect lying within 2 cm of the liver margin. Patients with nodules had higher mean RA pressures (18 mmHg ± 5.6 vs. 13 mmHg ± 4, p=0.025), whereas their mixed venous saturation and aortic saturation was not significantly different (70% ± 11 vs. 67% ± 9 and 92% ± 10 vs. 94% ± 4, p>0.05). Post-mortem histology suggests focal nodular hyperplasia is the underlying pathology. ConclusionsAbnormalities of hepatic blood flow and the presence of arterialised nodules are common in the failing Fontan circulation. They occur especially when central venous pressures are high, and very likely indicate arterialisation of hepatic blood flow and reciprocal portal venous deprivation. The underlying pathology is most likely focal nodular hyperplasia. PMID:20557964

  7. Postpriapism erectile dysfunction and shunt-related urethral stricture: long-term morbidity after proximal shunt for ischaemic priapism

    PubMed Central

    Bello, Jibril Oyekunle

    2014-01-01

    Recent guidelines have advocated for step-wise treatment of increasing invasiveness in the management of ischaemic priapism though with low-level evidences. In the past, proximal shunts were favoured as first-line treatment. We present an African man who had proximal shunt (cavernoso-spongiosal) three decades ago for ischaemic priapism and subsequently had long-term morbidity over the three decades with adverse effect on his quality of life. Recent guidelines appear to be sound despite their limitations and more invasive cavernoso-spongiosal shunts may be associated with significant long-term morbidities and poor quality of life. PMID:25709730

  8. POLYETHYLENE ENCAPSULATES FOR HAZARDOUS WASTE DRUMS

    EPA Science Inventory

    This capsule report summarizes studies of the use of polyethylene (P.E.) for encapsulating drums of hazardous wastes. Flat PE sheet is welded to roto moded PE containers which forms the encapsulates. Plastic pipe welding art was used, but the prototype welding apparatus required ...

  9. Pathogenesis and Management of Hepatolithiasis: A Report of Two Cases.

    PubMed

    Dey, Biswajit; Kaushal, Gourav; Jacob, Sajini Elizabeth; Barwad, Adarsh; Pottakkat, Biju

    2016-03-01

    Hepatolithiasis or primary intrahepatic stones are prevalent in the Far-East countries such as Korea, Japan and Taiwan. It has been associated with helminthiasis, bacterial infections, environmental and dietary factors. Despite high prevalence of helminthiasis like ascariasis, poor environmental condition and low protein diet, India and Middle-East countries have a low incidence of hepatolithiasis. We report two cases of hepatolithiasis associated with bacterial infections and were surgically managed. The first case is a 45-year-old female presenting with upper abdominal pain and fever. She had multiple calculi in intrahepatic biliary radicles, common bile duct, common hepatic duct and gall bladder. She was managed by cholecystectomy, left lateral liver sectionectomy, choledochoscopy assisted stone clearance of the residual liver and Roux-en-Y hepatico-jejunostomy. The second case is a 60-year-old female presenting with epigastric pain and fever and past history of cholecystectomy for cholelithiasis. She had multiple right and left intrahepatic calculi and managed by left lateral liver sectionectomy with excision of CBD and Roux-en-Y hepatico-jejunostomy. Both the cases showed growth of bacteria in the culture of the intraoperatively collected bile. PMID:27134934

  10. Pathogenesis and Management of Hepatolithiasis: A Report of Two Cases

    PubMed Central

    Kaushal, Gourav; Jacob, Sajini Elizabeth; Barwad, Adarsh; Pottakkat, Biju

    2016-01-01

    Hepatolithiasis or primary intrahepatic stones are prevalent in the Far-East countries such as Korea, Japan and Taiwan. It has been associated with helminthiasis, bacterial infections, environmental and dietary factors. Despite high prevalence of helminthiasis like ascariasis, poor environmental condition and low protein diet, India and Middle-East countries have a low incidence of hepatolithiasis. We report two cases of hepatolithiasis associated with bacterial infections and were surgically managed. The first case is a 45-year-old female presenting with upper abdominal pain and fever. She had multiple calculi in intrahepatic biliary radicles, common bile duct, common hepatic duct and gall bladder. She was managed by cholecystectomy, left lateral liver sectionectomy, choledochoscopy assisted stone clearance of the residual liver and Roux-en-Y hepatico-jejunostomy. The second case is a 60-year-old female presenting with epigastric pain and fever and past history of cholecystectomy for cholelithiasis. She had multiple right and left intrahepatic calculi and managed by left lateral liver sectionectomy with excision of CBD and Roux-en-Y hepatico-jejunostomy. Both the cases showed growth of bacteria in the culture of the intraoperatively collected bile. PMID:27134934

  11. The H + HeH(+) → He + H2(+) reaction from the ultra-cold regime to the three-body breakup: exact quantum mechanical integral cross sections and rate constants.

    PubMed

    De Fazio, Dario

    2014-06-21

    In this work, we present a quantum mechanical scattering study of the title reaction from 1 mK to 2000 K. Total integral cross sections and thermal rate constants are compared with previous theoretical and experimental data and with simpler theoretical models to understand the range of validity of the approximations used in the previous studies. The obtained quantum reactive observables have been found to be nearly insensitive to the roto-vibrational energy of the reactants at high temperatures. More sensitive to the reactant's roto-vibrational energy are the data in the cold and ultra-cold regimes. The implications of the new data presented here in the early universe scenario are also discussed and analyzed. PMID:24810283

  12. Simultaneous characterization of rotational and translational diffusion of optically anisotropic particles by optical microscopy

    NASA Astrophysics Data System (ADS)

    Giavazzi, Fabio; Haro-Pérez, Catalina; Cerbino, Roberto

    2016-05-01

    We probe the roto-translational Brownian motion of optically anisotropic particles suspended in water with a simple and straightforward optical microscopy experiment that does not require positional or rotational particle tracking. We acquire a movie of the suspension placed between two polarizing elements and we extract the translational diffusion coefficient D T and the rotational diffusion coefficient D R from the analysis of the temporal correlation properties of the spatial Fourier modes of the intensity fluctuations in the movie. Our method is successfully tested with a dilute suspension of birefringent spherical colloidal particles obtained by polymerizing an emulsion of droplets of liquid crystal in a nematic phase, whose roto-translational dynamics is found to be well described by theory. The simplicity of our approach makes our method a viable alternative to particle tracking and depolarized dynamic light scattering.

  13. Simultaneous characterization of rotational and translational diffusion of optically anisotropic particles by optical microscopy.

    PubMed

    Giavazzi, Fabio; Haro-Pérez, Catalina; Cerbino, Roberto

    2016-05-18

    We probe the roto-translational Brownian motion of optically anisotropic particles suspended in water with a simple and straightforward optical microscopy experiment that does not require positional or rotational particle tracking. We acquire a movie of the suspension placed between two polarizing elements and we extract the translational diffusion coefficient D T and the rotational diffusion coefficient D R from the analysis of the temporal correlation properties of the spatial Fourier modes of the intensity fluctuations in the movie. Our method is successfully tested with a dilute suspension of birefringent spherical colloidal particles obtained by polymerizing an emulsion of droplets of liquid crystal in a nematic phase, whose roto-translational dynamics is found to be well described by theory. The simplicity of our approach makes our method a viable alternative to particle tracking and depolarized dynamic light scattering. PMID:27093398

  14. Rotary peening with captive shot

    SciTech Connect

    1998-02-01

    Roto Peen with captive shot removes coatings and surface contamination from concrete floors. The objective of treating radioactively contaminated concrete floors during the Deactivation and Decommissioning (D and D) process is to reduce the surface contamination levels to meet regulatory criteria for unrestricted use. The US Department of Energy (DOE) Chicago Operations office and DOE`s Federal Energy Technology Center (FETC) jointly sponsored a Large-Scale Demonstration Project (LSDP) at the Chicago Pile-5 Research Reactor (CP-5) at Argonne National Laboratory-East (ANL). The objective of the LSDP is to demonstrate potentially beneficial D and D technologies in comparison with current baseline technologies. As part of the LSDP, roto Peen with captive shot was demonstrated March 17--20, 1997, to treat a 20 x 25 ft area of radioactively contaminated concrete floor on the service level of the CP-5 building.

  15. Subtotal gastrectomy for diffused hemorrhagic gastritis induced by radiation, following liver resection for hilar cholangiocarcinoma. A case report

    PubMed Central

    Vasileios, Tatsis; Evaggelia, Peponi; Georgios, Papadopoulos; Periklis, Tsekeris; Michael, Fatouros; Georgios, Glantzounis

    2015-01-01

    Introduction A rare case of hemorrhagic gastritis induced by radiation is presented, which was resistant to conservative treatment and required subtotal gastrectomy. Presentation of case A 56-year-old male was initially undergone right hepatectomy, resection of the extrahepatic biliary tree, hilar lymph node dissection and hepatico-jejunostomy due to advanced hilar cholangiocarcinoma. Because of the extent of the disease, chemo-radiotherapy was administered. The patient received a total radiotherapy dose of 57.6 Gy in 32 sessions. Unfortunately, diffused hemorrhagic gastritis induced by radiation was developed, which was resistant to conservative treatment (endoscopic hemostasis, transfusion). A subtotal gastrectomy was performed. The patient is in good condition 45 months after the liver resection, but with local recurrence. Conclusion In resistant situations to conservative treatment and recurred bleeding of diffused hemorrhagic gastritis induced by radiation, surgical management may have a role. PMID:26686486

  16. Anaesthesia for biliary atresia and hepatectomy in paediatrics

    PubMed Central

    Jacob, Rebecca

    2012-01-01

    The scope of this article precludes an ‘in depth’ description of all liver problems and I will limit this review to anaesthesia for biliary atresia — a common hepatic problem in the very young — and partial hepatectomy in older children. I will not be discussing the problems of anaesthetising children with hepatitis, cirrhosis, congenital storage diseases or liver failure. Extrahepatic biliary obstruction is an obliterative cholangiopathy of infancy which is fatal if untreated. Diagnosis involves exclusion of other causes of neonatal jaundice and treatment involves a hepatico portoenterostomy carried out at the earliest. This is a review of current concepts in anaesthesia and postoperative management of neonates with extrahepatic biliary atresia. Anaesthesia for hepatic resection has seen great changes in recent times with the improvement in surgical techniques, technology and a better understanding of the underlying physiology. These are reviewed along with the problems of postoperative pain management. PMID:23293387

  17. Analytic Model for the Rototranslational Torsion Pendulum

    NASA Astrophysics Data System (ADS)

    De Marchi, F.; Bassan, M.; Pucacco, G.; Marconi, L.; Stanga, R.; Visco, M.

    2013-01-01

    We develop an analytic model to describe the motion of the RotoTranslational Torsion Pendulum PETER in a wide range of frequencies (from 1mHz up to 10-15Hz). We also try to explain some unexpected features we found in the data with only 1 soft degree of freedom and we estimate values for the misalignment angles and other parameters of the model.

  18. Roll-Out and Turn-Off Display Software for Integrated Display System

    NASA Technical Reports Server (NTRS)

    Johnson, Edward J., Jr.; Hyer, Paul V.

    1999-01-01

    This report describes the software products, system architectures and operational procedures developed by Lockheed-Martin in support of the Roll-Out and Turn-Off (ROTO) sub-element of the Low Visibility Landing and Surface Operations (LVLASO) program at the NASA Langley Research Center. The ROTO portion of this program focuses on developing technologies that aid pilots in the task of managing the deceleration of an aircraft to a pre-selected exit taxiway. This report focuses on software that produces a system of redundant deceleration cues for a pilot during the landing roll-out, and presents these cues on a head up display (HUD). The software also produces symbology for aircraft operational phases involving cruise flight, approach, takeoff, and go-around. The algorithms and data sources used to compute the deceleration guidance and generate the displays are discussed. Examples of the display formats and symbology options are presented. Logic diagrams describing the design of the ROTO software module are also given.

  19. Energy patterns in twist-opening models of DNA with solvent interactions.

    PubMed

    Tabi, Conrad Bertrand; Bineli, Grégoire; Mohamadou, Alidou

    2015-09-01

    Energy localization, via modulation instability, is addressed in a modified twist-opening model of DNA with solvent interactions. The Fourier expansion method is used to reduce the complex roto-torsional equations of the system to a set of discrete coupled nonlinear Schrödinger equations, which are used to perform the analytical investigation of modulation instability. We find that the instability criterion is highly influenced by the solvent parameters. Direct numerical simulations, performed on the generic model, further confirm our analytical predictions, as solvent interactions bring about highly localized energy patterns. These patterns are also shown to be robust under thermal fluctuations. PMID:26051121

  20. Gangliosides, or sialic acid, antagonize ethanol intoxication

    SciTech Connect

    Klemm, W.R.; Boyles, R.; Matthew, J.; Cherian, L.

    1988-01-01

    Because ethanol elicits a dose-dependent hydrolysis of brain sialogangliosides, the authors tested the possibility that injected gangliosides might antagonize intoxicating doses of ethanol. Clear anti-intoxication effects were seen at 24 hr post-injection of mixed mouse-brain gangliosides at 125-130 mg/kg, but not at lower or higher doses. Sleep time was reduced on the order of 50%, and roto-rod agility was significantly enhanced. Sialic acid (SA) similarly antagonized ethanol; however, the precursor of SA, N-acetyl-D-mannosamine, as well as ceramide and asialoganglioside did not.

  1. A novel approach to motion correction for ASL images based on brain contours

    NASA Astrophysics Data System (ADS)

    Tarroni, Giacomo; Castellaro, Marco; Boffano, Carlo; Bruzzone, Maria Grazia; Bertoldo, Alessandra; Grisan, Enrico

    2015-03-01

    Motion correction in Arterial Spin Labeling (ASL) is essential to accurately assess brain perfusion. Motion correction techniques are usually based on intensity-related information, which might be unreliable in ASL due to local intensity differences between control and labeled acquisitions and to non-uniform volume magnetization caused by background-suppressed acquisition protocols. Accordingly, a novel motion correction technique based only on brain contour points is presented and tested against a widely used intensity-based technique (MCFLIRT). The proposed Contour-Based Motion Correction (CBCM) technique relies on image segmentation (to extract brain contour point clouds) and on Iterative Closest Point algorithm (to estimate the roto-translation required to align them). At variance with other approaches based on point clouds alignment, the local 3D curvature is also computed for each contour point and used as an additional coordinate to increase the accuracy of the alignment. The technique has been tested along with MCFLIRT on a database of randomly roto-translated brain volumes. Several error metrics have been computed and compared between the two techniques. The results show that the proposed technique is able to achieve a higher accuracy than MCFLIRT without any intensity-dependent information.

  2. Pentek metal coating removal system: Baseline report; Summary

    SciTech Connect

    1997-07-31

    The Pentek metal coating removal system consists of the ROTO-PEEN Scaler, CORNER-CUTTER(R), and VAC-PAC(R). The system is designed to remove coatings from steel, concrete, brick, and wood. The Scaler uses 3M ROTO-PEEN tungsten carbide cutters, while the CORNER-CUTTER(R) uses solid needles for descaling activities. These are used with the VAC-PAC(R) vacuum system to capture dust and debris as removal of the coating takes place. The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. Dust exposure was minimal, but noise exposure was significant. Further testing for each exposure is recommended, since the outdoor environment where the testing demonstration took place may skew the results. It is feasible that dust and noise levels will be higher in an enclosed operating environment. Other areas of concern found were arm-hand vibration, whole-body vibration, ergonomics, heat stress, tripping hazards, electrical hazards, machine guarding, and lockout/tagout.

  3. Pentek metal coating removal system: Baseline report

    SciTech Connect

    1997-07-31

    The Pentek coating removal technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The Pentek coating removal system consisted of the ROTO-PEEN Scaler, CORNER-CUTTER{reg_sign}, and VAC-PAC{reg_sign}. They are designed to remove coatings from steel, concrete, brick, and wood. The Scaler uses 3M Roto Peen tungsten carbide cutters while the CORNER-CUTTER{reg_sign} uses solid needles for descaling activities. These hand tools are used with the VAC-PAC{reg_sign} vacuum system to capture dust and debris as removal of the coating takes place. The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. Dust exposure minimal, but noise exposure was significant. Further testing for each exposure is recommended because of the environment where the testing demonstration took place. It is feasible that the dust and noise levels will be higher in an enclosed operating environment of different construction. In addition, other areas of concern found were arm-hand vibration, whole-body, ergonomics, heat stress, tripping hazards, electrical hazards, machine guarding, and lockout/tagout.

  4. Pentek metal coating removal system: Baseline report; Greenbook (chapter)

    SciTech Connect

    1997-07-31

    The Pentek coating removal technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The Pentek coating removal system consisted of the ROTO-PEEN Scaler, CORNER-CUTTER{reg_sign}, and VAC-PAC{reg_sign}. They are designed to remove coatings from steel, concrete, brick, and wood. The Scaler uses 3M Roto Peen tungsten carbide cutters while the CORNER-CUTTER{reg_sign} uses solid needles for descaling activities. These hand tools are used with the VAC-PAC{reg_sign} vacuum system to capture dust and debris as removal of the coating takes place. The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. Dust exposure minimal, but noise exposure was significant. Further testing for each exposure is recommended because of the environment where the testing demonstration took place. It is feasible that the dust and noise levels will be higher in an enclosed operating environment of different construction. In addition, other areas of concern found were arm-hand vibration, whole-body, ergonomics, heat stress, tripping hazards, electrical hazards, machine guarding, and lockout/tagout.

  5. [Surgical treatment of iatrogenic bile duct injuries following laparoscopic cholecystectomy: analysis of long-term results. Retrospective clinical study in 51 patients operated in the Campania region from 1991 to 2003].

    PubMed

    Conzo, Giovanni; Amato, Giuseppe; Angrisani, Luigi; Bardi, Ugo; Barone, Giovanni; Belli, Giulio; Brancaccio, Umberto; Calise, Fulvio; Caliendo, Angelo; Celsi, Salvatore; Corcione, Francesco; Cuccurullo, Diego; De Falco, Giuseppe; Delrio, Paolo; De Werra, Carlo; De Sena, Guido; Docimo, Giovanni; Esposito, Maria Grazia; Fantini, Corrado; Giardiello, Cristiano; Musella, Mario; Molino, Carlo; Muto, Crescenzo; Pennetti, Lucio; Puziello, Alessandro; Porcelli, Alberto; Rea, Roberto; Rendano, Franco; Palazzo, Antonietta; Santangelo, Michele; Santaniello, Walter; Santini, Luigi; Sperlongano, Pasquale; Stanzione, Francesco; Tartaglia, Alberto; Tricarico, Annunziato; Vincenti, Rodolfo; Lorenzo, Michele

    2005-01-01

    An higher incidence rate of iatrogenic bile duct injuries is reported in cholecystectomy performed with the laparoscopy than with the laparotomy approach. The aim of this study was to provide a multicentre report on surgical treatment and the outcome of biliary complications during and following laparoscopic cholecystectomy. A questionnaire was mailed to all surgeons with experience in laparoscopic cholecystectomy in the Campania region. Data were collected from January 1991 to December 2003. Each patient was requested to indicate age, gender, associated diseases, site and type of lesion, surgical experience, diagnosis, treatment and complications. Twenty-six surgeons answered the questionnaire. Fifty-one patients (36 F/15 M; mean age: 42.5 +/- 11.9, range 13-91 years) with bile duct injuries following laparoscopic cholecystectomy were reported. The most frequent lesions were main bile duct partial or total transection. The intraoperative mortality rate was 1/51 (1.9%) due to a complex biliary and vascular injury. The postoperative mortality rate of revision surgery was 5/50 (10%). T-tube positioning (n = 20) and Roux-en-Y hepato-jejunostomy (n = 20) were the procedures most frequently performed. The complication rate in patients treated with the T-tube was significantly higher than in those treated with hepatico-jejunostomy. Surgical treatment of biliary injuries following laparoscopic cholecystectomy was characterized by unusually high mortality and morbidity for a non-neoplastic disease. Roux-en-Y hepato-jejunostomy remains the procedure of choice for these injuries. PMID:16060179

  6. [Congenital dilatation of the biliary system in adult: about three clinical cases].

    PubMed

    Ungania, Silvio; Barletta, Nives

    2011-01-01

    The authors refer to three cases of congenital dilatation of the biliary system in an adult, an extremely rare pathology in the West, with no specific symptomatology, and therefore often discovered accidentally and unexpectedly The first patient had suffered from unexplained periods of fever since childhood, the second had only complained of vague abdominal pains a years before diagnosis; for the third, a Romanian woman, it was the first time she complained of a biliary colic. All the patients had an Ultrasound, a CT scan and a MRCP (magnetic resonance cholangiopancretography). Based on the Todani classification, the first and the third case belongs to type IV A, while the second is a type I. In all three patients the pathology was resolved due to an operation entailing disconnection of the biliary-pancreatic tract, with complete surgical removal of the dilated bile ducts followed by a Roux-en-Y hepatico-jejunostomy. Nevertheless the procedures undertaken are not immune to criticism: in the first and second case the diagnostic imagery had not immediately produced a clear interpretation, leading to a delay in the diagnosis and the execution in the first of a not anodyne ERCP; in the third case a colecistectomy was performed as it were as an intermediary measure; finally there was probably omitted a thorough explanation to the patient with regard to a pathology deserving of a careful follow-up for the possible recidivist of the infectious phenomena and above all the onset of the dangerous degeneration carcinomatosa. PMID:22229240

  7. [A case of primary neuroendocrine carcinoma of the bile duct].

    PubMed

    Hamanaka, Michiko; Nakahira, Shin; Takeda, Yutaka; Kawashima, Hiroshi; Mukai, Yosuke; Kanemura, Takeshi; Uchiyama, Chieko; Okishiro, Masatsugu; Takeno, Atsushi; Suzuki, Rei; Taniguchi, Hirokazu; Egawa, Chiyomi; Nakata, Ken; Miki, Hirofumi; Kato, Takeshi; Nagano, Teruaki; Nakatsuka, Shinichi; Tamura, Shigeyuki

    2012-11-01

    A 74-year-old man presented to a physician with a chief complaint of jaundice. He was diagnosed with bile duct carcinoma and admitted to our hospital. Laboratory data revealed abnormally elevated levels of total bilirubin, serum hepatic transaminase, and CA19-9. Endoscopic retrograde cholangiopancreatography revealed neoplastic stenosis from the hilus hepatis to the common bile duct. Abdominal computed tomography (CT) revealed an enhancing tumor in the hilus hepatis bile duct, and positron emission tomography-CT (PET-CT) revealed abnormal fluorodeoxyglucose accumulation in the tumor. Under a diagnosis of hilar cholangiocarcinoma, the patient underwent an extended right hepatectomy and left hepatico -jejunostomy. Immunohistochemically, the tumor cells were positive for neuroendocrine markers such as chromogranin A, synaptophysin, and CD56. The tumor was diagnosed as primary neuroendocrine carcinoma of the bile duct. The patient exhibited multiple liver metastasis 6 months after the operation. Transcatheter arterial chemoembolization (TACE) was performed for the liver metastasis. Although TACE exerted a cytoreductive effect temporarily, multiple liver abscesses developed. The patient died of liver failure 16 months after the operation. We report this rare case of primary neuroendocrine carcinoma of the bile duct. PMID:23267998

  8. Magnetoelastic coupling forbidden by time-reversal symmetry: Spin-direction-dependent magnetoelastic coupling on MnO, CoO, and NiO

    NASA Astrophysics Data System (ADS)

    Lee, Sanghyun; Ishikawa, Yoshihisa; Miao, Ping; Torii, Shuki; Ishigaki, Toru; Kamiyama, Takashi

    2016-02-01

    In the Landau free energy, which is a powerful tool for describing the physical properties and phase transitions in condensed-matter physics, it has been generally believed that time-reversal symmetry allows only even-power polynomials in the magnetic moment when magnetic transition happens. Although no experimental evidence supports it, this symmetry constraint is very strict in theory. On the other hand, MnO, CoO, and NiO have been extensively studied for several decades since these materials are used to test advance experimental and theoretical methods. However, their precise spin directions and phase-transition mechanism have remained as a long-standing problem until now. To resolve these issues, we used the cutting-edge time-of-flight neutron powder diffractometer (SuperHRPD) at the Japan Proton Accelerator Research Complex (J-PARC) to study the spin-direction-dependent magnetoelastic coupling in MnO, CoO, and NiO. We also constructed a group-subgroup structure relation from F m -3 m to C 2 /m with exchange striction and a type of magnetostriction (dipolar and roto magnetostriction). These unified viewpoints and the high-resolution neutron powder diffractometer enable us to construct an order-parameter vector diagram. The order-parameter vector diagram reveals distinguished order-parameter coupling and phase-transition characters by different Γ1+(Ag) and Γ2+(Bg) spin direction. Moreover, the experiment results show clearly that the CoO6 octahedral distortion and the Co magnetic moment couple through a magnetoelastic coupling ɛoct˜M3 , which is forbidden by time-reversal symmetry but allowed by the more general magnetic symmetry—the so-called rotation-time-reversal symmetry in the double antisymmetry space group. Rotation-time-reversal symmetry allows the coupling of odd-power polynomials in the spin vector and odd-power ones in the roto vector when both spin- and roto-axial vectors belong to the same irreducible representation in Landau free energy. Here

  9. Self-dynamics of hydrogen gas as probed by means of inelastic neutron scattering

    NASA Astrophysics Data System (ADS)

    Guarini, Eleonora; Orecchini, Andrea; Formisano, Ferdinando; Demmel, Franz; Petrillo, Caterina; Sacchetti, Francesco; Bafile, Ubaldo; Barocchi, Fabrizio

    2005-12-01

    The neutron double-differential cross-section of molecular hydrogen at low density has been measured at two rather low scattering angles and different final neutron energies by means of three-axis spectrometry. This first inelastic scattering determination of the single-particle roto-translational dynamics of room temperature H2 allows for a detailed test of the theoretical modelling of the spectral line-shapes of such a fundamental molecule, performed by referring both to a careful quantum-mechanical treatment and to a simpler semi-classical approximation. A comprehensive report on the neutron measurements and data analysis is presented, along with an overview of the theories used for comparison with the experimental results. An encouraging picture of the present capabilities in the calculation of the true dynamic response of hydrogen gas to slow and thermal neutrons is obtained, opening new perspectives for accurate data calibration in inelastic neutron spectroscopy, with special relevance for small-angle experiments.

  10. Evaluation of the film-coating properties of a hydroxyethyl cellulose/hydroxypropyl methylcellulose polymer system.

    PubMed

    Li, Shun Por; Martellucci, Stephen A; Bruce, Richard D; Kinyon, Adam C; Hay, Michael B; Higgins, John D

    2002-04-01

    The effect of different grades of hydroxyethyl cellulose (HEC) and hydroxypropyl methllcellulose (HPMC) on the film-formation and taste-masking ability for ibuprofen granules was evaluated. Three batches of coated ibuprofen granules were prepared using a roto-granulator, each with a different coating composition. Two grades of HEC [MW300,000 (H) and MW90,000 (L)] were combined with three different grades of HPMC [MW 11,000 (L), MW 25,000 (M) and MW 35,000 (H)] to prepare the coating solutions. Mechanical strength and physical properties of the polymer films were evaluated. Films made from HPMC (L)/HEC (H), HPMC (M)/HEC (H), and HPMC (H)/HEC (H) were stronger and more flexible than the HPMC (L) HEC (L) films. The assay, dissolution, particle size distribution, and environmental scanning electron microscopy (ESEM) data of the three batches of the coated ibuprofen granules were similar. PMID:12056532

  11. Credit PSR. The northwest and southwest facades appear as seen ...

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

    Credit PSR. The northwest and southwest facades appear as seen when looking northeast (460). Doors have been opened to show the interiors of the oxidizer dust receiver room at left; the building equipment room (air conditioning) is on the right. The dust receiver is a Roto-Clone Type N hydrostatic precipitator, which uses a 5 horsepower vacuum motor. Refrigeration units are mounted on pads immediately to the right of the building in this view. The grinder room is at the far end of the building; access to it is gained via double doors on the left where a hoist beam projects out from the top of the door opening. Building 4284/E85 (Oxidizer Dryer Blender) appears in the left background; 4283/E-84 (Oxidizer Grinder) appears in the right background - Jet Propulsion Laboratory Edwards Facility, Oxidizer Grinder Building, Edwards Air Force Base, Boron, Kern County, CA

  12. PTC-6 vacuum system: WallWalker{trademark} and Blastrac{reg_sign} shot blast cleaning system

    SciTech Connect

    1998-02-01

    The LTC Americas, Inc. wall decontamination technology consisted of two pneumatic hand-held tools: (1) a roto-peen scaler that used star cutters and (2) a 3-piston hammer with reciprocating bits. The hand-held tools were used in conjunction with the LTC PTC-6 vacuum system which captured dust and debris as the wall decontamination took place. Recommendations for improved worker safety and health during use of the PTC-6 vacuum system with hand-held tools include: (1) keeping all hoses and lines as orderly as possible in compliance with good housekeeping requirements; (2) ergonomic training to include techniques in lifting, bending, stooping, twisting, etc.; (3) use of a clamping system to hold hoses to the vacuum system; (4) a safety line on the air line connections; (5) use of a mechanical lifting system for waste drum removal; and (6) the use of ergonomically designed tools.

  13. Pattern formation in chemically interacting active rotors with self-propulsion.

    PubMed

    Liebchen, Benno; Cates, Michael E; Marenduzzo, Davide

    2016-09-21

    We demonstrate that active rotations in chemically signalling particles, such as autochemotactic E. coli close to walls, create a route for pattern formation based on a nonlinear yet deterministic instability mechanism. For slow rotations, we find a transient persistence of the uniform state, followed by a sudden formation of clusters contingent on locking of the average propulsion direction by chemotaxis. These clusters coarsen, which results in phase separation into a dense and a dilute region. Faster rotations arrest phase separation leading to a global travelling wave of rotors with synchronized roto-translational motion. Our results elucidate the physics resulting from the competition of two generic paradigms in active matter, chemotaxis and active rotations, and show that the latter provides a tool to design programmable self-assembly of active matter, for example to control coarsening. PMID:27526180

  14. Guest-host interactions in gas clathrate hydrates under pressure

    NASA Astrophysics Data System (ADS)

    Izquierdo-Ruiz, F.; Otero-de-la-Roza, A.; Contreras-García, J.; Menéndez, J. M.; Prieto-Ballesteros, O.; Recio, J. M.

    2015-01-01

    First-principles calculations were performed to determine equilibrium geometries, static equation of state parameters, the energetics and orientation of the guest molecule inside the 5? and 5?6? cages, and vibrational frequencies of methane clathrate hydrate. According to our results, the progressive inclusion of one ? molecule in each clathrate cavity is always a stabilizing process up to saturation. The released energy is very similar for both types of cages. In agreement with the experimental observation of roto-vibrational spectra in this hydrate, we calculate an energy barrier of less than 0.5 kcal/mol, indicating free rotation of methane inside the cages. The stabilizing effect of applied pressure leads to a red shift of the O-H stretching frequencies of the water molecules of around 80 cm? in average at 1 GPa. This paper was presented at the LIIth European High Pressure Research Group (EHPRG 52) Meeting in Lyon (France), 7-12 September 2014.

  15. Future Directions in Rotorcraft Technology at Ames Research Center

    NASA Technical Reports Server (NTRS)

    Aiken, Edwin W.; Ormiston, Robert A; Young, Larry A.

    2000-01-01

    Members of the NASA and Army rotorcraft research community at Ames Research Center have developed a vision for 'Vertical Flight 2025'. This paper describes the development of that vision and the steps being taken to implement it. In an effort to realize the vision, consistent with both NASA and Army Aviation strategic plans, two specific technology development projects have been identified: (1) one focused on a personal transportation system capable of vertical flight (the 'Roto-Mobile') and (2) the other on small autonomous rotorcraft (which is inclusive of vehicles which range in grams of gross weight for 'MicroRotorcraft' to thousands of kilograms for rotorcraft uninhabited aerial vehicles). The paper provides a status report on these projects as well as a summary of other revolutionary research thrusts being planned and executed at Ames Research Center.

  16. Spectroscopic and thermodynamic properties of molecular hydrogen dissolved in water at pressures up to 200 MPa

    SciTech Connect

    Borysow, Jacek Rosso, Leonardo del; Celli, Milva; Ulivi, Lorenzo; Moraldi, Massimo

    2014-04-28

    We have measured the Raman Q-branch of hydrogen in a solution with water at a temperature of about 280 K and at pressures from 20 to 200 MPa. From a least-mean-square fitting analysis of the broad Raman Q-branch, we isolated the contributions from the four lowest individual roto-vibrational lines. The vibrational lines were narrower than the pure rotational Raman lines of hydrogen dissolved in water measured previously, but significantly larger than in the gas. The separations between these lines were found to be significantly smaller than in gaseous hydrogen and their widths were slightly increasing with pressure. The lines were narrowing with increasing rotational quantum number. The Raman frequencies of all roto-vibrational lines were approaching the values of gas phase hydrogen with increasing pressure. Additionally, from the comparison of the integrated intensity signal of Q-branch of hydrogen to the integrated Raman signal of the water bending mode, we have obtained the concentration of hydrogen in a solution with water along the 280 K isotherm. Hydrogen solubility increases slowly with pressure, and no deviation from a smooth behaviour was observed, even reaching thermodynamic conditions very close to the transition to the stable hydrogen hydrate. The analysis of the relative hydrogen concentration in solution on the basis of a simple thermodynamic model has allowed us to obtain the molar volume for the hydrogen gas/water solution. Interestingly, the volume relative to one hydrogen molecule in solution does not decrease with pressure and, at high pressure, is larger than the volume pertinent to one molecule of water. This is in favour of the theory of hydrophobic solvation, for which a larger and more stable structure of the water molecules is expected around a solute molecule.

  17. Physics of Electrodeless UV Lamps and Applications of UV Radiation

    NASA Astrophysics Data System (ADS)

    Cekic, Miodrag; Ruckman, Mark

    2004-12-01

    Electrodeless discharge microwave powered ultraviolet limps are a special class of high power incoherent UV sources, conceptualized forty years ago for industrial processing applications. Because of the nonimaging character of the applications, the need for measuring averaged properties of the lamps' exceeds the motivation to obtain detailed space-resolved discharge parameters. This writing discusses measurements of the average plasma temperature of a 5.8kW high pressure mercury bulb and a XeCl* excimer bulb driven by the microwaves of the same power. First method is based on the black body radiance fit to the self-absorbed 185nm and 254nm mercury lines. The second method is essentially Boltzmann plot method applied to the roto-vibrational levels of B1/2 - X1/2 XeCl* molecular transition with a maximum at 308nm. We also present a procedure for evaluation of effectiveness of different bulb spectra to the given UV curing chemistry system independent from the Beer-Lambert law. Conversely, the procedure can be used for the optimization of the chemistry to the chosen UV lamp radiance spectrum.

  18. Measured Aerodynamic Interaction of Two Tiltrotors

    NASA Technical Reports Server (NTRS)

    Yamauchi, Gloria K.; Wadcock, Alan J.; Derby, Michael R.

    2003-01-01

    The aerodynamic interaction of two model tilrotors in helicopter-mode formation flight is investigated. Three cenarios representing tandem level flight, tandem operations near the ground, and a single tiltrotor operating above thc ground for varying winds are examined. The effect of aircraft separation distance on the thrust and rolling moment of the trailing aircraft with and without the presence of a ground plane are quantified. Without a ground plane, the downwind aircraft experiences a peak rolling moment when the right (left) roto- of the upwind aircraft is laterally aligned with the left (right) rotor of the downwind aircraft. The presence of the ground plane causes the peak rolling moment on the downwind aircraft to occur when the upwind aircraft is further outboard of the downwind aircraft. Ground plane surface flow visualization images obtained using rufts and oil are used to understand mutual interaction between the two aircraft. These data provide guidance in determining tiltrotor flight formations which minimize disturbance to the trailing aircraft.

  19. On the group-theoretical approach to the study of interpenetrating nets.

    PubMed

    Baburin, Igor A

    2016-05-01

    Using group-subgroup and group-supergroup relations, a general theoretical framework is developed to describe and derive interpenetrating 3-periodic nets. The generation of interpenetration patterns is readily accomplished by replicating a single net with a supergroup G of its space group H under the condition that site symmetries of vertices and edges are the same in both H and G. It is shown that interpenetrating nets cannot be mapped onto each other by mirror reflections because otherwise edge crossings would necessarily occur in the embedding. For the same reason any other rotation or roto-inversion axes from G \\ H are not allowed to intersect vertices or edges of the nets. This property significantly narrows the set of supergroups to be included in the derivation of interpenetrating nets. A procedure is described based on the automorphism group of a Hopf ring net [Alexandrov et al. (2012). Acta Cryst. A68, 484-493] to determine maximal symmetries compatible with interpenetration patterns. The proposed approach is illustrated by examples of twofold interpenetrated utp, dia and pcu nets, as well as multiple copies of enantiomorphic quartz (qtz) networks. Some applications to polycatenated 2-periodic layers are also discussed. PMID:27126113

  20. Effect of Intrinsic Twist on Length of Crystalline and Disordered Regions in Cellulose Microfibrils

    NASA Astrophysics Data System (ADS)

    Nili, Abdolmadjid; Shklyaev, Oleg; Zhao, Zhen; Zhong, Linghao; Crespi, Vincent

    2013-03-01

    Cellulose is the most abundant biological material in the world. It provides mechanical reinforcement for plant cell wall, and could potentially serve as renewable energy source for biofuel. Native cellulose forms a non-centrosymmetric chiral crystal due to lack of roto-inversion symmetry of constituent glucose chains. Chirality of cellulose crystal could result in an overall twist. Competition between unwinding torsional/extensional and twisting energy terms leads to twist induced frustration along fibril's axis. The accumulated frustration could be the origin of periodic disordered regions observed in cellulose microfibrils. These regions could play significant role in properties of cellulose bundles and ribbons as well as biological implications on plant cell walls. We propose a mechanical model based on Frenkel-Kontorova mechanism to investigate effects of radius dependent twist on crystalline size in cellulose microfibrils. Parameters of the model are adjusted according to all-atom molecular simulations. This work is supported by the US Department of Energy, Office of Basic Energy Sciences as part of The Center for LignoCellulose Structure and Formation, an Energy Frontier Research Center

  1. A High Spatial Resolution CT Scanner for Small Animal Imaging

    NASA Astrophysics Data System (ADS)

    Cicalini, E.; Baldazzi, G.; Belcari, N.; Del Guerra, A.; Gombia, M.; Motta, A.; Panetta, D.

    2006-01-01

    We have built a micro-CT system that will be integrated with a small animal PET scanner. The components are: an X-ray source with a peak voltage of up to 60 kV, a power of 10 W and a focal spot size of 30 μm; a CCD coupled to CsI(Tl) scintillator, subdivided into 128×3072 square pixels, each with a size of 48 μm; stepping motors for the sample roto-translation; a PCI acquisition board; electronic boards to control and read-out the CCD. A program in Lab VIEW controls the data acquisition. Reconstruction algorithms have been implemented for fan-beam and cone-beam configurations. Images of a bar pattern have been acquired to evaluate the detector performance: the CTF curve has been extracted from the data, obtaining a value of 10 % at 5 lp/mm and about 3 % at 10 lp/mm. Tomographic acquisitions have been performed with a test phantom consisting of a Plexiglas cylinder, 3 cm in diameter, with holes ranging from 3 mm down to 0.6 mm in diameter, filled with different materials. The contrast resolution has been extracted from the reconstructed images: a value of 6 % (in water) for a cubic voxel size of 80 μm has been obtained.

  2. Surface-hopping trajectories for OH(A{sup 2}Σ{sup +}) + Kr: Extension to the 1A″ state

    SciTech Connect

    Perkins, T.; McCrudden, G.; Brouard, M.; Herráez-Aguilar, D.; Aoiz, F.J.; Kłos, J.

    2015-04-14

    We present a new trajectory surface hopping study of the rotational energy transfer and collisional quenching of electronically excited OH(A) radicals by Kr. The trajectory surface hopping calculations include both electronic coupling between the excited 2{sup 2}A′ and ground 1{sup 2}A′ electronic states, as well as Renner-Teller and Coriolis roto-electronic couplings between the 1{sup 2}A′ and 1{sup 2}A″, and the 2{sup 2}A′ and 1{sup 2}A″ electronic states, respectively. The new calculations are shown to lead to a noticeable improvement in the agreement between theory and experiment in this system, particularly with respect to the OH(X) rotational and Λ-doublet quantum state populations, compared with a simpler two-state treatment, which only included the electronic coupling between the 2{sup 2}A′ and 1{sup 2}A′ states. Discrepancies between the predictions of theory and experiment do however remain, and could arise either due to errors in the potential energy surfaces and couplings employed, or due to the limitations in the classical treatment of non-adiabatic effects.

  3. Schoen manifold with line bundles as resolved magnetized orbifolds

    NASA Astrophysics Data System (ADS)

    Nibbelink, Stefan Groot; Vaudrevange, Patrick K. S.

    2013-03-01

    We give an alternative description of the Schoen manifold as the blow-up of a {{{Z}}_2}× {{{Z}}_2} orbifold in which one {{{Z}}_2} factor acts as a roto-translation. Since for this orbifold the fixed tori are only identified in pairs but not orbifolded, four-dimensional chirality can never be obtained in heterotic string compactifications using standard techniques alone. However, chirality is recovered when its tori become magnetized. To exemplify this, we construct an E8 × E8' heterotic SU(5) GUT on the Schoen manifold with Abelian gauge fluxes, which becomes an MSSM with three generations after an appropriate Wilson line is associated to its freely acting involution. We reproduce this model as a standard heterotic orbifold CFT of the (partially) blown down Schoen manifold with a magnetic flux. Finally, in analogy to a proposal for non-perturbative heterotic models by Aldazabal et al. we suggest modifications to the heterotic orbifold spectrum formulae in the presence of magnetized tori.

  4. The multi layered approach for AGM separators

    SciTech Connect

    Ferreira, A.L.

    1999-05-01

    The present absorbent glass mat separate is an offspring of the filtration medium and special paper industries. In these industries, the traditional method of manufacturing micro-glass mats, was to blend two or more types of fibers together in an aqueous acidic solution and deposit this blend onto a moving endless wire or onto a roto-former, another version of an endless wire. The sheet acquires consistency as the water is withdrawn, it is then pressed and dried against heated drums. The methods of fiber dispersion and deposition can be changed so that the different constituent fiber types of an AGM separator are processed separately in distinct and separate layers. This fiber segregation results in changes to some key characteristics of the separator and brings some very definite advantages to the VRLA battery performance. Various key characteristics of the battery are enhanced, such as its ability to deliver higher currents at the higher discharge rates. This paper sets out some basic principles for the manufacturer of wet laid microglass fiber mats. Also important AGM characteristics, such as wicking, porosity/pore size and stratification are analyzed in light of the multilayered AGM design. These characteristics are radically modified and as a consequence the VRLA battery high rate and cycling performances are equally affected.

  5. A multi-layered approach for absorptive glass-mat separators

    NASA Astrophysics Data System (ADS)

    Ferreira, A. L.

    The traditional method of manufacturing absorptive glass mats (AGMs) for valve-regulated lead-acid (VRLA) batteries is to blend two or more types of fibres together in an aqueous acidic solution and deposit this blend on to either a moving endless wire or a roto-former (another version of an endless wire). The sheet acquires consistency as the water is withdrawn; it is then pressed and dried against heated drums. The methods of fibre dispersion and deposition can be changed so that the different constituent fibre types of an AGM separator are processed separately in distinct and separate layers. This fibre segregation results in the enhancement of some key characteristics of the separator and thus brings some very definite advantages to the performance of VRLA batteries, e.g., the ability to deliver higher currents at higher discharge rates. Also, important AGM characteristics, such as wicking, porosity/pore-size and stratification, are radically modified by adoption of the multi-layered AGM design. As a consequence, the high-rate and cycling performances of VRLA batteries are equally affected.

  6. LTC vacuum blasting machine (metal): Baseline report; Summary

    SciTech Connect

    1997-07-31

    The LTC coating removal system consists of several hand tools such as a Roto Peen scaler and a needlegun. They are designed to remove coatings from steel, concrete, brick, and wood. These are used with the LTC PTC-6 vacuum system to capture dust and debris as removal of the coating takes place. The PTC-6 is a vacuum system designed to be used with surface decontamination equipment. Dust and debris are captured by a high efficiency particulate filter (HEPA) vacuum system that deposits the waste directly into an on-board 23-gallon waste drum. The PTC-6 utilizes compressed air delivered from a source via an air hose connected to the air inlet to drive the hand held power tools. The control panel regulated the air pressure delivered to the tool. A separate compressed air flow powers the vacuum generator. The vacuum hoses connect the power tools to the dust chamber, returning paint chips and dust from the surface. A third compressed air flow is used to clean filters by pulsing air through a pipe with slots. The blasts of air shake dust and debris from the filter fabric.

  7. Numerical simulation of 3D unsteady flow in a rotating pump by dynamic mesh technique

    NASA Astrophysics Data System (ADS)

    Huang, S.; Guo, J.; Yang, F. X.

    2013-12-01

    In this paper, the numerical simulation of unsteady flow for three kinds of typical rotating pumps, roots blower, roto-jet pump and centrifugal pump, were performed using the three-dimensional Dynamic Mesh technique. In the unsteady simulation, all the computational domains, as stationary, were set in one inertial reference frame. The motions of the solid boundaries were defined by the Profile file in FLUENT commercial code, in which the rotational orientation and speed of the rotors were specified. Three methods (Spring-based Smoothing, Dynamic Layering and Local Re-meshing) were used to achieve mesh deformation and re-meshing. The unsteady solutions of flow field and pressure distribution were solved. After a start-up stage, the flow parameters exhibit time-periodic behaviour corresponding to blade passing frequency of rotor. This work shows that Dynamic Mesh technique could achieve numerical simulation of three-dimensional unsteady flow field in various kinds of rotating pumps and have a strong versatility and broad application prospects.

  8. A molecular dynamics simulation of hydrogen atoms collisions on an H-preadsorbed silica surface

    NASA Astrophysics Data System (ADS)

    Rutigliano, M.; Gamallo, P.; Sayós, R.; Orlandini, S.; Cacciatore, M.

    2014-08-01

    The interaction of hydrogen atoms and molecules with a silica surface is relevant for many research and technological areas. Here, the dynamics of hydrogen atoms colliding with an H-preadsorbed β-cristobalite (0 0 1) surface has been studied using a semiclassical collisional method in conjunction with a recently developed analytical potential energy surface based on density functional theory (DFT) calculations. The atomic recombination probability via an Eley-Rideal (E-R) mechanism, as well as the probabilities for other competitive surface processes, have been determined in a broad range of collision energies (0.04-3.0 eV) for off-normal (θv = 45°) and normal (θv = 0°) incidence and for two different surface temperatures (TS = 300 and 1000 K). H2,gas molecules form in roto-vibrational excited levels while the energy transferred to the solid surface is below 10% for all simulated conditions. Finally, the global atomic recombination coefficient (γE-R) and vibrational state resolved recombination coefficients (γ(v)) were calculated and compared with the available experimental values. The calculated collisional data are of interest in chemical kinetics studies and fluid dynamics simulations of silica surface processes in H-based low-temperature, low-pressure plasmas.

  9. LTC America`s, Inc. PTC-6 vacuum system (metal): Baseline report

    SciTech Connect

    1997-07-31

    The LTC coating removal technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The LTC coating removal system consisted of several hand tools, a Roto Peen scaler, and a needlegun. They are designed to remove coatings from steel, concrete, brick, and wood. These hand tools are used with the LTC PTC-6 vacuum system to capture dust and debris as removal of the coating takes place. The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. The dust exposure was minimal but noise exposure was significant. Further testing for each exposure is recommended because of the environment where the testing demonstration took place. It is feasible that the dust and noise levels will be higher in an enclosed operating environment of different construction. In addition, other areas of concern found were arm-hand vibration, whole body vibration, ergonomics, heat stress, tripping hazards, electrical hazards, machine guarding, and lockout/tagout.

  10. Intermolecular polarizabilities in H{sub 2}-rare-gas mixtures (H{sub 2}–He, Ne, Ar, Kr, Xe): Insight from collisional isotropic spectral properties

    SciTech Connect

    Głaz, Waldemar Bancewicz, Tadeusz; Godet, Jean-Luc; Gustafsson, Magnus; Maroulis, George; Haskopoulos, Anastasios

    2014-08-21

    The report presents results of theoretical and numerical analysis of the electrical properties related to the isotropic part of the polarizability induced by interactions within compounds built up of a hydrogen H{sub 2} molecule and a set of noble gas atoms, Rg, ranging from the least massive helium up to the heaviest xenon perturber. The Cartesian components of the collisional polarizabilities of the H{sub 2}–Rg systems are found by means of the quantum chemistry methods and their dependence on the intermolecular distance is determined. On the basis of these data, the spherical, symmetry adapted components of the trace polarizability are derived in order to provide data sets that are convenient for evaluating collisional spectral profiles of the isotropic polarized part of light scattered by the H{sub 2}–Rg mixtures. Three independent methods of numerical computing of the spectral intensities are applied at room temperature (295 K). The properties of the roto-translational profiles obtained are discussed in order to determine the role played by contributions corresponding to each of the symmetry adapted parts of the trace polarizability. By spreading the analysis over the collection of the H{sub 2}–Rg systems, evolution of the spectral properties with the growing masses of the supermolecular compounds can be observed.

  11. LTC vacuum blasting machine (metal) baseline report: Greenbook (chapter)

    SciTech Connect

    1997-07-31

    The LTC coating removal technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The LTC coating removal system consisted of several hand tools, a Roto Peen scaler, and a needlegun. They are designed to remove coatings from steel, concrete, brick, and wood. These hand tools are used with the LTC PTC-6 vacuum system to capture dust and debris as removal of the coating takes place. The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. The dust exposure was minimal but noise exposure was significant. Further testing for each exposure is recommended because of the environment where the testing demonstration took place. It is feasible that the dust and noise levels will be higher in an enclosed operating environment of different construction. In addition, other areas of concern found were arm-hand vibration, whole-body vibration, ergonomics, heat stress, tripping hazards, electrical hazards, machine guarding, and lockout/tagout.

  12. LTC vacuum blasting machine (metal): Baseline report

    SciTech Connect

    1997-07-31

    The LTC coating removal technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The LTC coating removal system consisted of several hand tools, a Roto Peen scaler, and a needlegun. They are designed to remove coatings from steel, concrete, brick, and wood. These hand tools are used with the LTC PTC-6 vacuum system to capture dust and debris as removal of the coating takes place. The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. The dust exposure was minimal but noise exposure was significant. Further testing for each exposure is recommended because of the environment where the testing demonstration took place. It is feasible that the dust and noise levels will be higher in an enclosed operating environment of different construction. In addition, other areas of concern found were arm-hand vibration, whole-body vibration, ergonomics, heat stress, tripping hazards, electrical hazards, machine guarding, and lockout/tagout.

  13. Large landslides induced by fluvial incision in the Cenozoic Duero Basin (Spain)

    NASA Astrophysics Data System (ADS)

    Yenes, M.; Monterrubio, S.; Nespereira, J.; Santos, G.; Fernández-Macarro, B.

    2015-10-01

    The Pleistocene opening of the endorheic Duero River drainage basin (northwestern Spain and central Portugal) has led to river incision, creation of steep valley sides, and development of large (> 0.1 km2) and episodically active rotational and roto-translational landslides along river reaches where a weak geological lithology has been exposed by river erosion. These landslides occur in the central part of the Duero basin despite low precipitation, weak contemporary seismicity, and low regional relief. These landslides occurred as a result of the downcutting of the Duero River and its tributaries through a sequence of Miocene basin-fill sediments. In the last few thousand years the incision reached a series of high-plasticity, low-strength clay layers within the sedimentary sequence. Owing to this mechanism, these landslides occurred in a specific area at a specific period of time. All of the large landslides are located at the outside of meander bends, suggesting that river lateral erosion facilitated slip failures. Recent anthropogenic activities to control river flows and to stabilize river banks have decreased the possibility of future landslides in this area.

  14. Proton emission from a laser ion source

    SciTech Connect

    Torrisi, L.; Cavallaro, S.; Gammino, S.; Cutroneo, M.; Margarone, D.

    2012-02-15

    At intensities of the order of 10{sup 10} W/cm{sup 2}, ns pulsed lasers can be employed to ablate solid bulk targets in order to produce high emission of ions at different charge state and kinetic energy. A special interest is devoted to the production of protons with controllable energy and current from a roto-translating target irradiated in repetition rate at 1-10 Hz by a Nd:Yag pulsed laser beam. Different hydrogenated targets based on polymers and hydrates were irradiated in high vacuum. Special nanostrucutres can be embedded in the polymers in order to modify the laser absorption properties and the amount of protons to be accelerated in the plasma. For example, carbon nanotubes may increase the laser absorption and the hydrogen absorption to generate high proton yields from the plasma. Metallic nanostrucutres may increase the electron density of the plasma and the kinetic energy of the accelerated protons. Ion collectors, ion energy analyzer, and mass spectrometers, used in time-of-flight configuration, were employed to characterize the ion beam properties. A comparison with traditional proton ion source is presented and discussed.

  15. Fragment approach to constrained density functional theory calculations using Daubechies wavelets.

    PubMed

    Ratcliff, Laura E; Genovese, Luigi; Mohr, Stephan; Deutsch, Thierry

    2015-06-21

    In a recent paper, we presented a linear scaling Kohn-Sham density functional theory (DFT) code based on Daubechies wavelets, where a minimal set of localized support functions are optimized in situ and therefore adapted to the chemical properties of the molecular system. Thanks to the systematically controllable accuracy of the underlying basis set, this approach is able to provide an optimal contracted basis for a given system: accuracies for ground state energies and atomic forces are of the same quality as an uncontracted, cubic scaling approach. This basis set offers, by construction, a natural subset where the density matrix of the system can be projected. In this paper, we demonstrate the flexibility of this minimal basis formalism in providing a basis set that can be reused as-is, i.e., without reoptimization, for charge-constrained DFT calculations within a fragment approach. Support functions, represented in the underlying wavelet grid, of the template fragments are roto-translated with high numerical precision to the required positions and used as projectors for the charge weight function. We demonstrate the interest of this approach to express highly precise and efficient calculations for preparing diabatic states and for the computational setup of systems in complex environments. PMID:26093548

  16. Liquid-Vapor Equilibrium Isotopic Fractionation of Water. How well can classical water models predict it?

    SciTech Connect

    Chialvo, Ariel A; Horita, Juske

    2009-01-01

    The liquid-vapor equilibrium isotopic fractionation of water is determined by molecular-based simulation, via Gibbs Ensemble Monte Carlo and isothermal-isochoric molecular dynamics involving two radically different but realistic models, the extended simple point charge (SPC/E) and the Gaussian charge polarizable (GCP) models. The predicted temperature dependence of the liquid-vapor equilibrium isotopic fractionation factors for H 2 18O / H 2 16O, H 2 17O / H 2 16O, and 2H 1H 16O / 1H 2 16O are compared against the most accurate experimental datasets to assess the ability of these intermolecular potential models to describe quantum effects according to the Kirkwood-Wigner free energy perturbation ! 2 !expansion. Predictions of the vapor pressure isotopic effect for the H 2 18O / H 2 16O and H 2 17O / H 2 16O pairs are also presented in comparison with experimental data and two recently proposed thermodynamic modeling approaches. Finally, the simulation results are used to discuss some approximations behind the microscopic interpretation of isotopic fractionation based on the underlying roto-translational coupling.

  17. Fragment approach to constrained density functional theory calculations using Daubechies wavelets

    SciTech Connect

    Ratcliff, Laura E.; Genovese, Luigi; Mohr, Stephan; Deutsch, Thierry

    2015-06-21

    In a recent paper, we presented a linear scaling Kohn-Sham density functional theory (DFT) code based on Daubechies wavelets, where a minimal set of localized support functions are optimized in situ and therefore adapted to the chemical properties of the molecular system. Thanks to the systematically controllable accuracy of the underlying basis set, this approach is able to provide an optimal contracted basis for a given system: accuracies for ground state energies and atomic forces are of the same quality as an uncontracted, cubic scaling approach. This basis set offers, by construction, a natural subset where the density matrix of the system can be projected. In this paper, we demonstrate the flexibility of this minimal basis formalism in providing a basis set that can be reused as-is, i.e., without reoptimization, for charge-constrained DFT calculations within a fragment approach. Support functions, represented in the underlying wavelet grid, of the template fragments are roto-translated with high numerical precision to the required positions and used as projectors for the charge weight function. We demonstrate the interest of this approach to express highly precise and efficient calculations for preparing diabatic states and for the computational setup of systems in complex environments.

  18. Surface-hopping trajectories for OH(A(2)Σ(+)) + Kr: extension to the 1A″ state.

    PubMed

    Perkins, T; Herráez-Aguilar, D; McCrudden, G; Kłos, J; Aoiz, F J; Brouard, M

    2015-04-14

    We present a new trajectory surface hopping study of the rotational energy transfer and collisional quenching of electronically excited OH(A) radicals by Kr. The trajectory surface hopping calculations include both electronic coupling between the excited 2(2)A' and ground 1(2)A' electronic states, as well as Renner-Teller and Coriolis roto-electronic couplings between the 1(2)A' and 1(2)A″, and the 2(2)A' and 1(2)A″ electronic states, respectively. The new calculations are shown to lead to a noticeable improvement in the agreement between theory and experiment in this system, particularly with respect to the OH(X) rotational and Λ-doublet quantum state populations, compared with a simpler two-state treatment, which only included the electronic coupling between the 2(2)A' and 1(2)A' states. Discrepancies between the predictions of theory and experiment do however remain, and could arise either due to errors in the potential energy surfaces and couplings employed, or due to the limitations in the classical treatment of non-adiabatic effects. PMID:25877578

  19. Management of Bile Duct Injury at Various Stages of Presentation: Experience from a Tertiary Care Centre.

    PubMed

    Ibrarullah, Md; Sankar, S; Sreenivasan, K; Gavini, S R K

    2015-04-01

    The clinical presentation, management and outcome of all patients with bile duct injury who presented to our tertiary care centre at various stages after cholecystectomy were analyzed. The patients were categorized into three groups: group A-patients in whom the injury was detected during cholecystectomy, group B-patients who presented within 2 weeks of cholecystectomy and group C-patients who presented after 2 weeks of cholecystectomy. Our team acted as rescue surgeons and performed 'on-table' repair for injuries occurring in another unit or in another hospital. Strasberg classification of bile duct injury was followed. In group A, partial and complete transections were managed by repair over T-tube and high hepaticojejunostomy, respectively. Patients in group B underwent endoscopic retrograde cholangiogram and/or magnetic resonance cholangiogram to evaluate the biliary tree. Those with intact common bile duct underwent endoscopic papillotomy and stenting in addition to drainage of intra-abdominal collection when present. For those with complete transection, early repair was considered if there was no sepsis. In presence of intra-abdominal sepsis an attempt was made to create controlled external biliary fistula. This was followed by hepatico jejunostomy at least after 3 months. Group C patients underwent hepaticojejunostomy at least 6 weeks after the injury. The outcome was graded into three categories: grade A-no clinical symptoms, normal LFT; grade B-no clinical symptoms, mild derangement of LFT or occasional episodes of pain or fever; grade C-pain, cholangitis and abnormal LFT; grade D-surgical revision or dilatation required. Fifty nine patients were included in the study and the distribution was group A-six patients, group B-33 patients and group C-20 patients. In group A, one patient with complete transection of the right hepatic duct (type C) and partial injury to left hepatic duct (LHD) underwent right hepaticojejunostomy and repair of the LHD over

  20. Model-based estimation of adiabatic flame temperature during coal gasification

    NASA Astrophysics Data System (ADS)

    Sarigul, Ihsan Mert

    Coal gasification temperature distribution in the gasifier is one of the important issues. High temperature may increase the risk of corrosion of the gasifier wall or it may cause an increase in the amount of volatile compounds. At the same time, gasification temperature is a dominant factor for high conversion of products and completing the reactions during coal gasification in a short time. In the light of this information it can be said that temperature is one of key parameters of coal gasification to enhance the production of high heating value syngas and maximize refractory longevity. This study aims to predict the adiabatic flame temperatures of Australian bituminous coal and Indonesian roto coal in an entrained flow gasifier using different operating conditions with the ChemCAD simulation and design program. To achieve these objectives, two types of gasification parameters were carried out using simulation of a vertical entrained flow reactor: oxygen-to-coal feed ratio by kg/kg and pressure and steam-to-coal feed ratio by kg/kg and pressure. In the first part of study the adiabatic flame temperatures, coal gasification products and other coal characteristics of two types of coals were determined using ChemCAD software. During all simulations, coal feed rate, coal particle size, initial temperature of coal, water and oxygen were kept constant. The relationships between flame temperature, coal gasification products and operating parameters were fundamentally investigated. The second part of this study addresses the modeling of the flame temperature relation to methane production and other input parameters used previous chapter. The scope of this work was to establish a reasonable model in order to estimate flame temperature without any theoretical calculation. Finally, sensitivity analysis was performed after getting some basic correlations between temperature and input variables. According to the results, oxygen-to-coal feed ratio has the most influential

  1. A method to characterize the 3D geometry of complex landslides in clayey soils: the Valoria, Super-Sauze and La Valette case studies

    NASA Astrophysics Data System (ADS)

    Daehne, A.; Travelletti, J.; Malet, J.-P.; Corsini, A.; Ronchetti, F.

    2009-04-01

    Bedrock geometry drastically influences the kinematic deformation pattern of slow-moving landslides exhibiting some flow characteristics. The development of extension and compression zones within the landslide body is largely controlled by the geometry (crests, bumps, hollows) and roughness of the topography covered by the moving mass. A challenge to progress in the forecast of such type of landslides is to precisely define 3D geometrical and geomechanical models. The objective of this work is to present a methodology for 3D geometrical modelling of the landslide structure, and to discuss the main possible errors in integrating multi-source and multi-resolution data in the modelling. The methodology is presented through the analysis of three landslides with similar geomorphological features (e.g. flow-like geomorphology) and development patterns (retrogression of the crown, roto-translational failures of the upper part, and translational movements in the lower part), and for which an extensive dataset of geophysical, geotechnical and geomorphological information is available. The three cases studies are the complex Valoria earth-slide-flow located in the Northern Apennines, the Super-Sauze and La Valette mudslides in the French South Alps. All three landslides are predominantly developed in a clay-shale soil formation. First, interpretation of the multi-data information, their resolution and accuracy is presented for the landslides. Second, a procedure to construct 3D geometrical models of the landslides is proposed (by using the Rockware's Rockworks geological modeller) and the influence of the interpolation algorithms is discussed. It is demonstrated that the model uncertainty is strongly depending on the density and distribution of the input data which vary for the three landslides. The quality of several geometrical models is then compared; a best-fit is achieved by using available geological and geomorphological site interpretation.

  2. Synthesis, structure and magnetism in copper chalcochromite spinels

    NASA Astrophysics Data System (ADS)

    Neulinger, Janell Rebecca

    The copper chalcochromites (CuCr2X4 (X = S, Se, Te)) possess a rare combination of magnetic and electronic properties compared to other chalcogenide spinet materials. A precise structural and magnetic investigation of these materials was undertaken in order to facilitate technological exploitation of these unusual properties. CuCr2Se4, several halogenated derivatives of the form CuCr2Se4 -xXx (with X = Cl, Br, or I), and CuCr2S3Cl were prepared via powder methods and chemical vapor transport growth of single crystals. A variety of X-ray diffraction techniques were employed to determine the crystal structures of the synthesis products. The materials adopt a trigonal variation of the spinet structure type; the lower-symmetry structure includes a single threefold roto-inversion axis. Halogen doping introduces systematic changes in the properties of the chalcochromites, and the effects of halogen doping were monitored by magnetometry, soft X-ray spectroscopy, and magnetic microscopy techniques. Bulk magnetic properties were characterized by SQUID and vibrating sample magnetometry, at temperatures from 5 K to above the Curie temperatures. Soft X-ray spectroscopic measurements performed at the Advanced Light Source at Lawrence Berkeley National Laboratory included X-ray absorption (XAS) and X-ray magnetic circular dichroism (XMCD) experiments. Dichroic spectra at the Cr L2,3 and Cu L 2,3 absorption edges confirm a ferrimagnetic model of opposing magnetic sub-lattices localized on the Cr and Cu centers; increasing levels of halogen doping suppress the contribution from the copper sublattice and reduce T C. Magnetic domain imaging using the Photoelectron Electron Microscope (PEEM) at the Advanced Light Source indicates the presence of a variety of domain morphologies, including predominantly stripe domains reflecting the uniaxial symmetry of the trigonal spinel structure. The magnetic and structural features of the copper chalcochromites mark them as robust, tunable, and

  3. Acceptance test of a commercially available software for automatic image registration of computed tomography (CT), magnetic resonance imaging (MRI) and 99mTc-methoxyisobutylisonitrile (MIBI) single-photon emission computed tomography (SPECT) brain images.

    PubMed

    Loi, Gianfranco; Dominietto, Marco; Manfredda, Irene; Mones, Eleonora; Carriero, Alessandro; Inglese, Eugenio; Krengli, Marco; Brambilla, Marco

    2008-09-01

    This note describes a method to characterize the performances of image fusion software (Syntegra) with respect to accuracy and robustness. Computed tomography (CT), magnetic resonance imaging (MRI), and single-photon emission computed tomography (SPECT) studies were acquired from two phantoms and 10 patients. Image registration was performed independently by two couples composed of one radiotherapist and one physicist by means of superposition of anatomic landmarks. Each couple performed jointly and saved the registration. The two solutions were averaged to obtain the gold standard registration. A new set of estimators was defined to identify translation and rotation errors in the coordinate axes, independently from point position in image field of view (FOV). Algorithms evaluated were local correlation (LC) for CT-MRI, normalized mutual information (MI) for CT-MRI, and CT-SPECT registrations. To evaluate accuracy, estimator values were compared to limiting values for the algorithms employed, both in phantoms and in patients. To evaluate robustness, different alignments between images taken from a sample patient were produced and registration errors determined. LC algorithm resulted accurate in CT-MRI registrations in phantoms, but exceeded limiting values in 3 of 10 patients. MI algorithm resulted accurate in CT-MRI and CT-SPECT registrations in phantoms; limiting values were exceeded in one case in CT-MRI and never reached in CT-SPECT registrations. Thus, the evaluation of robustness was restricted to the algorithm of MI both for CT-MRI and CT-SPECT registrations. The algorithm of MI proved to be robust: limiting values were not exceeded with translation perturbations up to 2.5 cm, rotation perturbations up to 10 degrees and roto-translational perturbation up to 3 cm and 5 degrees. PMID:17549564

  4. Sustainable soil management practices and quality of potato grown on erodible lands.

    PubMed

    Antonious, G F; Lee, C M; Snyder, J C

    2001-07-01

    Land productivity can decline when top soil is lost. In Kentucky, limited resource farmers often produce vegetable crops on erodible lands. The objectives of this study were 1) to quantify the impact of three soil management practices (SMPs) on quantity of potato produced on erodible land, 2) to evaluate the impact of pyrethrin and azadirachtin insecticides on potato tuber quality, and 3) to assess the impact of yard waste compost on the chemical composition (ascorbic acid, free sugars, phenol contents) of potato tubers. Potatoes (Solanum tuberosum L. cv. Kennebec) were grown in a silty loam soil of 10% slope. Plots (n= 18) were 3.7 m wide and 22 m long (10% slope), with metal borders of 20 cm above ground level. Two botanical insecticides, Multi-Purpose Insecticide (containing pyrethrin 0.2%) and Neemix 4EC (containing 0.25% azadirachtin) were sprayed twice on potato foliage during each of two growing seasons (1997 and 1999) at the recommended rates of 6 lbs and 2 gallons.acre(-1), respectively. The SMPs were tall fescue strips (FS) intercropped between each two potato rows, soil mixed with yard waste compost (COM) and no-mulch (NM) treatment (roto-tilled bare soil). The experimental designwas a 2 x 3 x 3 factorial with main factors of two insecticides and three SMPs replicated three times. Average potato yield was lowest in NM and FS and highest in COM treatments. Yield obtained from the bottom of the plots was greater than that obtained from the top of plots. Tuber defects (rot, scab, sun green, hollow heart, necrosis, and vascular discoloration) were significantly different between the two growing seasons. The two insecticidal treatments did not have much influence on potato yield or tuber defects. Tubers obtained from tall fescue treatments had low levels of ascorbic acid and reducing sugars compared to compost treatments. PMID:11495021

  5. A simple thermodynamic model of diluted hydrogen gas/plasma for CFD applications

    NASA Astrophysics Data System (ADS)

    Quartapelle, L.; Muzzio, A.

    2015-06-01

    This work describes a simple thermodynamic model of the hydrogen gas at low densities and for temperatures going from those involving quantum rotations of ortho- and para-hydrogen up to the fully ionized state. The closed-form energy levels of Morse rotating oscillator given [D.C. Harris, M.D. Bertolucci, Symmetry and Spectroscopy (Dover, New York, 1989)] (but not those in Morse's original paper) are shown to provide an internal partition function of H2 that is a sufficiently accurate representation of that exploiting the state-of-the-art spectrum of roto-vibrational levels calculated by Pachucki and Komasa [K. Pachucki, J. Komasa, J. Chem. Phys. 130, 164113 (2009)]. A system of two coupled quadratic equations for molecular dissociation and atomic ionization at thermodynamical and chemical equilibrium is derived according to the statistical mechanics by assuming that the system is an ideal mixture containing molecules, neutral atoms and noninteracting protons and electrons. The system of two equations reduces to a single quartic equation for the ionization unknown, with the coefficients dependent on the temperature and the specific volume. Explicit relations for specific energy and entropy of the hydrogen ideal gas/plasma model are derived. These fully compatible equations of state provide a complete thermodynamic description of the system, uniformly valid from low temperatures up to a fully ionized state, with electrons and ions relaxed to one and the same temperature. The comparison with results of other models developed in the framework of the physical and chemical pictures shows that the proposed elementary model is adequate for computational fluid dynamics purposes, in applications with the hydrogen gas under diluted conditions and when the dissociation and ionization can be assumed at thermodynamical and chemical equilibrium.

  6. Evaluating landslide susceptibility in hillslopes of the Daunia Apennines (Apulia, Italy)

    NASA Astrophysics Data System (ADS)

    Andriani, G. F.; Parise, M.; Spagnoletta, A.; Walsh, N.

    2009-04-01

    Landslide susceptibility, defined as the probability of occurrence of slope movements in a given territory, is evaluated in this contribution by means of a computerized methodology in GIS environment, based upon geomorphological surveys, geotechnical characterization of involved materials, and hydrological analysis of time series of hourly rainfall. The Daunia Apennines are located at the north-western border of Apulia region (southern Italy), representing the outer front of the southern Italian Apenninic Range, and the transition to the Apulian foreland. They are characterized by hilly landscapes, rarely above 1,000 m a.s.l., and present outcropping rocks consisting of pre-Pliocene terrigenous sediments, and recent colluvial and alluvial deposits. The area is intensely affected by several types of slope movements, the most common being complex landslides (roto-translational slides evolving to debris- and/or earth-flows). Locally, rock failures in the more competent lithotypes, and mud flows in the prevailing clay deposits are also present. In most of the cases, slope movements are related to partial or total re-activation of dormant phenomena, triggered by prolonged, intense rainstorms. The sector between San Marco la Catola, Volturara Appula, Celenza Valfortore, Alberona and San Bartolomeo in Galdo, in the catchment of La Catola Torrent, a right tributary of the Fortore River, has been selected as sample area. With slope gradients around 20°, the area is highly affected by shallow instabilities, involving mostly clay terranes. The index parameters were determined on both fresh and remoulded samples of involved lithotypes, as well as the consolidated-drained (CD) and consolidated-undrained (CU) shear strength. Permeability was evaluated through determination of the hydraulic conductivity by means of aedometric tests and falling head permeability tests. The digital elevation model (DEM), from which using a class rating method the main environmental factors (slope

  7. Overcoming sustainability and energy challenges in polymer science via solid-state shear pulverization

    NASA Astrophysics Data System (ADS)

    Brunner, Philip

    Solid-state shear pulverization (SSSP) is an innovative, continuous, environmentally benign, and industrially scalable process used to make materials that cannot be made via conventional processing techniques, reduce material cost by eliminating processing steps, and/or produce materials with superior properties as a result of better break-up and dispersion of additives. The SSSP process employs a modified twin-screw extruder in which the barrels are cooled rather than heated. This allows for high shear and compressive forces on the material during operation, which results in repeated fragmentation and fusion steps in the solid state. Technologically, this thesis provides the first in-depth study of the concept of specific energy in SSSP and how this variable can be tailored to optimize the end-properties while lowering costs for processing homopolymer, blend, or polymer composite systems. Furthermore, this thesis demonstrates the successful injection molding of SSSP-processed materials. An 80/20 wt% polypropylene (PP) and microcrystalline cellulose composite was manufactured with SSSP and injection molded into a bottle cap. These caps showed major benefits over neat PP such as increased stiffness and reduction in oxygen permeability. Finally, a description is provided of how SSSP can be used as a one-step solid-state compounding process that can add color, UV stabilizers, anti-statics, and other processing aids to polymer and uniformly and effectively disperses them in the polymer while pulverizing to a fine powder for roto-molding. Scientifically, process-structure-property relationships are investigated in detail with several homopolymers. The SSSP process is used to disperse heterogeneous nucleation agents (naturally found in commercial pellets) in the polymer. This led to major structural changes such as an increase in crystallizability and crystallinity for poly(lactic acid) (PLA) and in rigid amorphous fraction (RAF) at constant crystallinity for Nylon 11

  8. Chemistry in Magnetohydrodynamic Shock Waves in Diffuse Molecular Clouds

    NASA Astrophysics Data System (ADS)

    Peimbert, Antonio

    1998-09-01

    Absorption observations of the CH+ molecule with column densities of up to 1014 cm-2 in diffuse molecular clouds in many lines of sight are reviewed, and compared to the reddening and to abundances and velocity shifts of molecules like CH. Special attention is placed on the observations of the line of sight towards ς Ophiuchi where high quality observations of many chemical species are available. The problem of the required CH+ is described, and many formation mechanisms from the literature are reviewed, finding that none of them is particularly apt at describing the observations towards ς-Oph. Two fluid J-type shock models are studied as an alternative. The necessary conditions for their formation are discussed, and it is shown how they are expected to be present widely in the interstellar medium. Plane parallel numerical integrations, for the particular case in which the magnetic field is perpendicular to the shock velocity, are employed to study the region of phase-space of initial conditions that will produce 2 fluid shocks. A chemical network is developed and formation of key molecules like CH+, CH and OH, along with the excited roto-vibrational levels of H2, are studied under the shock dynamics. These models are then compared to the observations of the different lines of sight, showing they are capable of reproducing the features of the observations towards most of those clouds. An attempt to model the line of sight towards ς-Oph is done, finding that a shock with a shock speed vs = 9.0km/s going through a cloud with a density of nH = 14cm-3 with a magnetic field of B = 4.7μG does a reasonable job at satisfying most of the observations with the exception of the highest rotational excited states of molecular hydrogen for which observations are available. There is a small family of solutions capable of explaining the observed results which make specific predictions for the velocity profiles of the H2 lines of various excited levels. New observations with

  9. Two Dimensional Spatially Resolved Two Photon Oxygen Atom Laser Induced Fluorescence Measurements in the Flow Field of the Arc Heated Facility L3K

    NASA Astrophysics Data System (ADS)

    Koch, U.; Gülhan, A.; Esser, B.

    2005-02-01

    The arc heated facility LBK in Cologne is designed to characterize thermal protection materials for re-entry vehicles in high enthalpy flow fields. Models with dimensions of 300 * 300 mm can be studied with stable flow conditions for 1800 s in the L3K. Typical model surface temperatures are 2000 K at pressure levels of up to 350 hPa and enthalpy levels up to 25 MJ/kg. Infrared thermography, pyrometry, emission spectroscopy, absorption and diode laser absorption spectroscopy, Coherent Anti Stokes Raman Spectroscopy ( CARS ) and 2 Dimensional Laser Induced Fluorescence of Nitrous Oxide ( 2D-NO-LIF ) have been used to study the flow conditions in the free stream and in shock layers at moderate enthalpy levels. At high enthalpy levels above 12 MJ/kg it will not be possible to apply the well established NO-LIF technique to characterise flow conditions, because the NO-density in these flow fields becomes too low and the NO formed in the shock regions near the models appears in rotational non equilibrium. Two photon O-atom-LIF-technique was applied to study the relative O-atom density in the flow field of the arc heated facility at high enthalpy levels. The free stream electronic temperature of O-atoms agrees with roto-translational temperature from CFD calculations. Different flow velocities could be detected in the free stream and in the shock region by scanning the excitation wavelength. Measured flow velocities perpendicular to the model surface are in good agreement with the results from CFD-calculations. It has been noticed that he accuracy of the velocity values can be improved by lowering the line width of the excitation laser light with an etalon. The shock standoff distances for the IMENS model were determined from the intensity profiles for different angles of attack and different flow conditions. The results have been compared with CFD-calculations. The shock standoff distances from the measurements and the calculation agree very well. The determination of the

  10. 2001 GPS and Classical Survey at Medicina Observatory: Local Tie and VLBI Antenna's Reference Point Determination

    NASA Astrophysics Data System (ADS)

    Vittuari, Luca; Sarti, Pierguido; Tomasi, Paolo

    2001-12-01

    During a 6 days campaign in June 2001, we have performed a local survey at Medicina Observatory using classical geodesy and GPS techniques in order to determine the effects of an undergone track repair. We have determined the position of the reference point P within a local and ITRF2000 (epoch 1997.0) reference frames using trilateration and triangulation: Pclas_{loc}^{2001}=(21.580pm0.001,45.536pm0.001,17.699pm0.001) Pclas_{loc}^{2001}=(21.580pm0.001,45.536pm0.001,17.699pm0.001) Pclas_{ITRF2000}^{1997.0}=(4461369.982pm0.001,919596.818pm0.001,4449559.207pm0.001) Kinematic GPS has also given interesting results:roto-translate the estimated coordinates from the local frame to ITRF2000, thus having the possibility to compare results of both measurement approaches, we have computed a 4+1 parametres transformation using a triangol surveyed with both methods. Comparing results given above with the values obtained making use of the position and velocities given by IERS for Medicina in ITRF2000 the agreement is striking especially for the classical technique. A complete tie between the 3-D forced centered local ground control network (materialised in May 2000) and the widely used older network (which is now experiencing some problems due to the disgregation of the concrete where bolts are situated) has also been realised. This will allow inter-comparison of results obtained by the different campaigns that have been carried out in the last decade. Finally, the position of the ASI-GPS permanent station has been estimated within the local ground control network. Thus, using classical methodology, a precise determination of the VLBI-GPS ex-centre vector has been possible.

  11. PSICHE: a new beamline dedicated to X-ray diffraction and tomography at high pressure at synchrotron SOLEIL

    NASA Astrophysics Data System (ADS)

    Guignot, N.; Itié, J.; Zerbino, P.; Delmotte, A.; Moreno, T.

    2013-12-01

    , making ADX measurements at the highest possible resolution on this beamline. This station will also be used for diffraction tomography experiments. The second focal point at 37.6 m is located behind KB mirrors on the third experimental station. 10x10 μm2 beam sizes (full width) are expected. This station will be used for DAC experiments, with or without our future laser heating setup. Finally, parallel beams can be produced with sizes up to 15x5 mm2 (HxV) for tomography experiments, in pink (filtered white) beam or monochromatic beam. We plan to use rotating anvils presses such as the rotoPEc (J. Philippe et al., 2013) to take full advantage of this beam mode, but it can be opened to other techniques. The PSICHE beamline is opened for users since July 2013. Some stations are not available yet, and will be opened through 2014 and 2015. References X. Dong et al., Ray tracing application in hard x-ray optical development: Soleil first wiggler beamline (PSICHÉ) case" (2011), Proc. SPIE 8141, 814113 Y. Wang et al., A new technique for angle-dispersive powder diffraction using an energy-dispersive setup and synchrotron radiation (2004), J. Appl. Cryst. 37, 947-956 J. Philippe, Y. Le Godec, F. Bergame et M. Morand, Patent INPI 11 62335 (2013)

  12. Woody debris transport modelling by a coupled DE-SW approach

    NASA Astrophysics Data System (ADS)

    Persi, Elisabetta; Petaccia, Gabriella; Sibilla, Stefano

    2016-04-01

    The presence of wood in rivers is gaining more and more attention: on one side, the inclusion of woody debris in streams is emphasized for its ecological benefits; on the other hand, particular attention must be paid to its management, not to affect hydraulic safety. Recent events have shown that wood can be mobilized during floodings (Comiti et al. 2008, Lange and Bezzola 2006), aggravating inundations, in particular near urban areas. For this reason, the inclusion of woody debris influence on the prediction of flooded areas is an important step toward the reduction of hydraulic risk. Numerical modelling plays an important role to this purpose. Ruiz-Villanueva et al. (2014) use a two-dimensional numerical model to calculate the kinetics of cylindrical woody debris transport, taking into account also the hydrodynamic effects of wood. The model here presented couples a Discrete Element approach (DE) for the calculation of motion of a cylindrical log with the solution of the Shallow Water Equations (SW), in order to simulate woody debris transport in a two-dimensional stream. In a first step, drag force, added mass force and side force are calculated from flow and log velocities, assuming a reference area and hydrodynamic coefficients taken from literature. Then, the equations of dynamics are solved to model the planar roto-translation of the wooden cylinder. Model results and its physical reliability are clearly affected by the values of the drag and side coefficients, which in turn depend upon log submergence and angle towards the flow direction. Experimental studies to evaluate drag and side coefficients can be found for a submerged cylinder, with various orientations (Gippel et al. 1996; Hoang et al. 2015). To extend such results to the case of a floating (non-totally submerged) cylinder, the authors performed a series of laboratory tests whose outcomes are implemented in the proposed DE-SW model, to assess the effects of these values on the dynamic of woody

  13. Study of the Martian Subsurface with a Fiber Optics Spectrometer: the Ma_Miss Experiment

    NASA Astrophysics Data System (ADS)

    Coradini, A.; de Sanctis, M. C.; Ammannito, E.; Boccaccini, A.; Battistelli, E.; Capanni, A.

    2009-04-01

    In this presentation is described the investigation that we intend to do with a small imaging spectrometer that will be inserted in the drill of the Exomars- Pasteur rover. This spectrometer is named Ma_miss (Mars Multispectral Imager for Subsurface Studies ). The Ma_Miss experiment is located in the drill ,that will be able to make a hole in the Mars soil and rock up to 2 m. Ma_Miss includes the optical head of the spectrometer, a lamp to illuminate the borehole walls, and the optical fiber that brings the signal to the spectrometer. The multispectral images are acquired by means of a sapphire window placed on the lateral wall of the drill tool, as close as possible to the drill head. The images are gathered by means of an optical fibre system and analyzed using the spectrometer. The Ma_Miss gathered light containing the scientific information is transferred to the array detector and electronics of the instrument by means of an optical rotary joint implemented in the roto-translation group of the drill, as shown in the next pictures In the figure is schematically represented the Ma_Miss- Dibs architecture. This experiment will be extremely valuable since it will allow, for the first time, to have an idea of the mineralogical composition of the Martian subsurface and to study freshly cut rocks. The study of surface and subsurface mineralogy of Martian soil and rocks is the key for understanding the chemico-physical processes that led to the formation and evolution of the Red Planet. The history of the water and other volatiles, as well as the signatures of weathering processes are important to understand present and past environmental conditions associated with the possibility of life. Surface samples are highly influenced by exogenous processes (weathering, erosion, sedimentation, impact) that alter their original properties. So, the analyses of uncontaminated samples by means of instrumented drills and in situ analytic stations are the key for unambiguous

  14. Modelling of Collision Induced Absorption Spectra Of H2-H2 Pairs for the Planetary Atmospheres Structure: The Second Overtone Band

    NASA Technical Reports Server (NTRS)

    Borysow, Aleksandra; Borysow, Jacek I.

    1998-01-01

    The main objective of the proposal was to model the collision induced, second overtone band of gaseous hydrogen at low temperatures. The aim of this work is to assist planetary scientists in their investigation of planetary atmospheres, mainly those of Uranus and Neptune. The recently completed extended database of collision induced dipole moments of hydrogen pairs allowed us, for the first time, to obtain dipole moment matrix elements responsible for the roto-vibrational collision induced absorption spectra of H2-H2 in the second overtone band. Despite our numerous attempts to publish those data, the enormous volume of the database did not allow us to do this. Instead, we deposited the data on a www site. The final part of this work has been partially supported by NASA, Division for Planetary Atmospheres. In order to use our new data for modelling purpose, we first needed to test how well we can reproduce the existing experimental data from theory, when using our new input data. Two papers resulted from this work. The obtained agreement between theoretical results and the measurements appeared to be within 10-30%. The obviously poorer agreement than observed for the first H2 overtone, the fundamental, and the rototranslational bands can be attributed to the fact that dipole moments responsible for the second overtone are much weaker, therefore susceptible to larger numerical uncertainties. At the same time, the intensity of the second overtone band is much weaker and therefore it is much harder to be measured accurately in the laboratory. We need to point out that until now, no dependable model of the 2nd overtone band was available for modelling of the planetary atmospheres. The only one, often referred to in previous works on Uranian and Neptune's atmospheres, uses only one lineshape, with one (or two) parameter(s) deduced at the effective temperature of Uranus (by fitting the planetary observation). After that, the parameter(s) was(were) made temperature

  15. Moléculas orgánicas no-rígidas

    NASA Astrophysics Data System (ADS)

    Senent Díez, M. L.

    Se destaca la importancia del estudio espectroscópico ab initio de una serie de moléculas no-rígidas detectadas en el medio interestelar (acetona, dimetil-eter, etanol, metanol, metilamina, ldots), así como los últimos avances del desarrollo de la metodología para el tratamiento teórico de estas especies. Se describe, a modo de ejemplo, el análisis del espectro roto-torsional de la molécula de glicoaldehido que ha sido recientemente detectada en el centro Galáctico Sagitario B2 (N) [1]. Esta especie presenta dos movimientos de gran amplitud que interaccionan, descansan en el Infrarrojo Lejano y le confiere propiedades no-rígidas. La molécula puede existir en posiciones cis y trans y presenta cinco confórmeros estables, tres de simetría Cs (I, II y IV) y un doble mínimo trans de simetría C1 (III) . La conformación favorita, I, presenta simetría Cs y se estabiliza por la formación de un puente de hidrógeno entre los grupos OH y C=O. Los mínimos secundarios II, III, y IV se han determinado a 1278.2 cm-1 (trans, Cs), 1298.8 cm-1 (trans, C1) y 1865.2 cm-1 (cis, Cs) con cálculos MP4/cc-pVQZ que incluyen sustituciones triples. Para determinar que vibraciones interaccionan con las torsiones, se ha realizado un análisis armónico en los mínimos. Las frecuencias fundamentales armónicas correspondientes al mínimo I se han calculado en 213.4 cm-1 (torsión C-C) y 425.7 cm-1 (torsión OH). Es de esperar que tan sólo dos vibraciones, la flexión del grupo C-C-O y el aleteo del hidrógeno del grupo aldehídico puedan desplazar el espectro torsional de la molécula aislada. Para determinar el espectro torsional, se ha determinado la superficie de potencial en dos dimensiones mediante el cálculo ab initio de las geometrías y energías de 74 conformaciones seleccionadas. Estas últimas se han ajustado a un doble serie de Fourier. A partir de la PES y de los parámetros cinéticos del Hamiltoniano vibracional se han obtenido frecuencias e intensidades

  16. Isotopic and Chemical Analysis of Nitrate Source and Cycling in the San Joaquin River, California

    NASA Astrophysics Data System (ADS)

    Silva, S. R.; Kendall, C.; Bemis, B.; Bergamaschi, B.; Kratzer, C.; Dileanis, P.; Erickson, D.; Avery, E.; Paxton, K.

    2001-12-01

    The sources and cycling of nitrate was investigated during a pilot study at four sites along the San Joaquin River using carbon and nitrogen isotopes of total dissolved and particulate organic matter along with hydrological measurements and various concentration data including chlorophyll-a. The nitrate source, its relationship to phytoplankton, and the effect of the nitrate source and cycling on the isotopic composition of dissolved and particulate organic matter were the primary concerns of the study. Samples were collected between July and October 2000 at (1) Crow's Landing, (2) Laird Park, (3) Vernalis, and (4) upstream of the Merced River. Particulate organic matter samples (POM) were collected on pre-combusted glass fiber filters. Combined dissolved organic and inorganic samples were prepared by roto-evaporating filtered waters (RV samples). Both the RV and the POM samples were acidified to eliminate inorganic carbon. Stable carbon and nitrogen isotopes and C:N ratios of POM in addition to chlorophyll-a concentrations were consistent with POM derived primarily from plankton at all sites and sampling times except in late October during a dam release event. The late October samples showed a shift toward isotopically heavier carbon and lighter nitrogen isotopes and higher C:N ratios reflecting a significant input from non-planktonic (probably terrestrial) sources. About 90 percent of the nitrogen in the RV samples was inorganic, 97 percent of which was in the form of nitrate. Assuming that the nitrogen isotopic composition of the minor organic fraction fell within the range of common organic samples (0 to 25 per mil), the delta 15N value of the RV samples was a close representation of the nitrogen isotopic composition of the nitrate. The POM and RV samples therefore appear to be reasonable proxies for the nitrogen isotopic compositions of plankton and nitrate, respectively. By comparison with other dissolved species, most of the variation in nitrate

  17. Principal Component Analysis and Target Transformation end-member recovery : application to last PFS MEX data.

    NASA Astrophysics Data System (ADS)

    D'Amore, M.; Palomba, E.; Zinzi, A.; Maturilli, A.; Helbert, J.

    2008-09-01

    Abstract The Martian surface is mainly composed by an altered particulate mineral regolith, ranging from micrometric to bulk rocks sizes. A central goal in planetary science is determination of soils composition, in order to reconstruct the planets' evolutionary story at local and global scale. This goal is nowadays carried out by the support of remote sensing data analysis, coming from spacecraft carrying instruments suite able to collect radiation coming from the planet in a wide spectral range. A very useful spectral range to investigate soils mineral composition and atmospherics components dynamics is the thermal infrared (broadly between 1-50 μm) because primary spectral signatures of targets' components fall in this spectral range (i.e. stretching and roto-vibrational band of Si-O, O-H-O, C-O). The Planetary Fourier Spectrometer (PFS), onboard ESA's Mars Express spacecraft, collects radiation in the 1-45 μm range. High spectral resolution observations cover almost the whole Martian surface with a very large temporal basis (about 2 Martian years). The current PFS dataset is composed of over 500.000 spectral observations, enough for application of statistical analysis methods, so this study is carried out by mean of the Factor Analysis (FA) technique [1] that is demonstrated to be able to extract independently variable components and to recover the spectral end-member present in a spectral dataset. These data offer the chance to study minor mineral components of atmospheric particulate as well of the surface [2]. Surface analysis form remote planetary data needs the correction for atmospheric signature [2], including all the components that contribute to observed radiaton, as carbon dioxide and water vapour or atmospheric particulates (dust water ice). Planetary apparent emissivity spectra can be accurately modelled [1] by linear combination of atmospherics spectral shapes, when observation are taken in a region of low to moderate atmospheric opacity and with

  18. Characterization and monitoring of the Séchilienne rock slope using 3D imaging methods (Isère, France)

    NASA Astrophysics Data System (ADS)

    Vulliez, Cindy; Guerin, Antoine; Abellán, Antonio; Derron, Marc-Henri; Jaboyedoff, Michel; Chanut, Marie-Aurélie; Dubois, Laurent; Duranthon, Jean-Paul

    2016-04-01

    detected, allowing us to estimate the susceptibility of the slope to three main failure mechanisms: planar sliding, wedge sliding and flexural toppling. Moreover, we carried out the 3D tracking of several homogenous rock compartments using the roto-translation matrix technique (Oppikofer et al., 2009) in order to quantify separately the translational and rotational components of displacements. Large-scale movements (from several dm to more than 10 m) were observed in the active area with a coupling between subsidence and toppling oriented towards the valley. Lateral structures that cut the rear active part also seem to be affected by a clockwise rotation around the topple axis. The acquisition of dense and accurate terrain information using LiDAR and SfM for studying the Séchilienne landslide has been useful for quantifying the 3D displacements and clarifying the failure mechanisms involved in the complex dynamic of the active part of the slope. Chanut, M-A., Dubois, L., Duranthon, J.P. (2014) Analyse de l'évolution du mouvement de terrain de Séchilienne à partir de données LiDAR. Journées Nationales de Géotechnique et de Géologie de l'Ingénieur JNGG2014 - Bauvais. Duranthon, J. P., & Effendiantz, L. (2004). Le versant instable des «Ruines» de Séchilienne. Bulletin des laboratoires des Ponts et Chaussées, 252, 253. Jaboyedoff, M., Metzger, R., Oppikofer, T., Couture, R., Derron, M. H., Locat, J., & Turmel, D. (2007). New insight techniques to analyze rock-slope relief using DEM and 3D-imaging cloud points: COLTOP-3D software, in: Rock mechanics: Meeting Society's Challenges and demands (Vol. 1, pp. 61-68). Kasperski, J., Potherat, P., & Duranthon, J. P. (2010). Le mouvement de versant de Séchilienne: point sur l'activité du phénomène, in: Rock Slope Stability (p. 13p). Oppikofer, T., Jaboyedoff, M., Blikra, L., Derron, M. H., & Metzger, R. (2009). Characterization and monitoring of the Åknes rockslide using terrestrial laser scanning, in: Natural Hazards