Science.gov

Sample records for active source experiments

  1. Preliminary Results from the iMUSH Active Source Seismic Experiment

    NASA Astrophysics Data System (ADS)

    Levander, Alan; Kiser, Eric; Palomeras, Imma; Zelt, Colin; Schmandt, Brandon; Hansen, Steve; Harder, Steven; Creagar, Kenneth; Vidale, John; Abers, Geoffrey

    2015-04-01

    iMUSH (imaging Magma Under Saint Helens) is a US NSF sponsored multi-disciplinary investigation of Mount Saint Helens (MSH), currently the most active volcano in the Cascades arc in the northwestern United States. The project consists of active and passive seismic experiments, extensive magnetotelluric sounding, and geological/geochemical studies involving scientists at 7 institutions in the U.S. and Europe. The long-term goal of the seismic project is to combine analysis of the active source data with that of data from the 70 element broadband seismograph operating from summer 2014 until 2016. Combining seismic and MT analyses with other data, we hope to image the MSH volcanic plumbing system from the surface to the subducting Juan de Fuca slab. Here we describe preliminary results of the iMUSH active source seismic experiment, conducted in July and August 2014. The active source experiment consisted of twenty-three 454 or 908 kg weight shots recorded by ~3500 seismographs deployed at ~6,000 locations. Of these instruments, ~900 Nodal Seismic instruments were deployed continuously for two weeks in an areal array within 10 km of the MSH summit. 2,500 PASSCAL Texan instruments were deployed twice for five days in 3 areal arrays and 2 dense orthogonal linear arrays that extended from MSH to distances > 80 km. Overall the data quality from the shots is excellent. The seismograph arrays also recorded dozens of micro-earthquakes beneath the MSH summit and along the MSH seismic zone, and numerous other local and regional earthquakes. In addition, at least one low frequency event beneath MSH was recorded during the experiment. At this point we have begun various types of analysis of the data set: We have determined an average 1D Vp structure from stacking short-term/long-term average ratios, we have determined the 2-D Vp structure from ray-trace inversions along the two orthogonal profiles (in the NW-SE and NE-SW directions), and we have made low-fold CMP stacks of the

  2. Field Report on the iMUSH Active Source Seismic Experiment

    NASA Astrophysics Data System (ADS)

    Kiser, E.; Levander, A.; Schmandt, B.; Palomeras, I.; Harder, S. H.; Creager, K. C.; Vidale, J. E.; Malone, S. D.

    2014-12-01

    In the second half of July we completed the iMUSH active source seismic experiment, one component of the Imaging Magma Under Saint Helens project. A team of ~75 volunteers deployed 3500 seismographs to ~5920 locations on and around Mount St. Helens over the course of 3 weeks. This instrument deployment was accompanied by 23 shots distributed around the volcano. Instrumentation consisted of ~2550 Reftek 125A (Texan) seismographs with 4.5 Hz geophones, and 920 Nodal Seismic recorders with 10 Hz geophones. The shots were also recorded by the permanent stations of the Pacific Northwest Seismograph Network and 70 iMUSH broadband seismographs. Fifteen of the shots, 424 kg each, formed two rings around Mount Saint Helens at 15 km and 30 km radius from the summit. Eight of the shots, 828 kg each, were fired at distances of 50 to 80 km from MSH on NW-SE and NE-SW azimuths. The deployment geometry consisted of two lines oriented NW/SE and NE/SW, and three arrays. The offset of the lines ranged from 150 km to 190 km with an average spacing of 200 m. The first array was centered on the volcano with a radius of 30 km, and required both driving and hiking to deploy. Arrays two and three were set out with, and centered on, the NW/SE line. These arrays had a distance range from MSH of 30-75 km and an azimuth range of about 100 degrees. In addition to this large-scale deployment, we set out 7 beamforming arrays approximately collocated with iMUSH broadband seismographs, and above clusters of seismicity in the region. The aperture of these arrays was about 1 km with an instrument spacing of 100 m. The final deployment ended only days before the AGU abstract deadline, so we have not yet examined all of the data. However, the preliminary indications are that signal to noise is excellent: The shots, several of which registered on PNSN as ML>2.1, carried across the entire array, and were recorded as far away as Seattle and Corvallis on permanent stations. The array also recorded a

  3. Calorimetric system for high-precision determination of activity of the 51Cr neutrino source in the BEST experiment

    NASA Astrophysics Data System (ADS)

    Veretenkin, E. P.; Gavrin, V. N.; Danshin, S. N.; Ibragimova, T. V.; Kalashnikova, A. A.; Kozlova, J. P.; Martynov, A. A.

    2017-01-01

    The calorimetric system based on mass-flow calorimeter for high-precision determination of neutrino flux from 51Cr source with activity 3MCi and higher is created for experiment BEST. The achieved heat release uncertainties are less than 0.25% in the whole range of the heat power and less than 0.1% in the range of 250-500 W. Total value the uncertainty considering the uncertainty of the energy release in the 51Cr decay (0.23%) shows that the activity of 3MCi 51Cr neutrino source can be determined with accuracy better than 0.5%.

  4. Theoretical and practical considerations for the design of the iMUSH active-source seismic experiment

    NASA Astrophysics Data System (ADS)

    Kiser, E.; Levander, A.; Harder, S. H.; Abers, G. A.; Creager, K. C.; Vidale, J. E.; Moran, S. C.; Malone, S. D.

    2013-12-01

    The multi-disciplinary imaging of Magma Under St. Helens (iMUSH) experiment seeks to understand the details of the magmatic system that feeds Mount St. Helens using active- and passive-source seismic, magnetotelluric, and petrologic data. The active-source seismic component of this experiment will take place in the summer of 2014 utilizing all of the 2600 PASSCAL 'Texan' Reftek instruments which will record twenty-four 1000-2000 lb shots distributed around the Mount St. Helens region. The instruments will be deployed as two consecutive refraction profiles centered on the volcano, and a series of areal arrays. The actual number of areal arrays, as well as their locations, will depend strongly on the length of the experiment (3-4 weeks), the number of instrument deployers (50-60), and the time it will take per deployment given the available road network. The current work shows how we are balancing these practical considerations against theoretical experiment designs in order to achieve the proposed scientific goals with the available resources. One of the main goals of the active-source seismic experiment is to image the magmatic system down to the Moho (35-40 km). Calculating sensitivity kernels for multiple shot/receiver offsets shows that direct P waves should be sensitive to Moho depths at offsets of 150 km, and therefore this will likely be the length of the refraction profiles. Another primary objective of the experiment is to estimate the locations and volumes of different magma accumulation zones beneath the volcano using the areal arrays. With this in mind, the optimal locations of these arrays, as well as their associated shots, are estimated using an eigenvalue analysis of the approximate Hessian for each possible experiment design. This analysis seeks to minimize the number of small eigenvalues of the approximate Hessian that would amplify the propagation of data noise into regions of interest in the model space, such as the likely locations of magma

  5. Active seismic experiment

    NASA Technical Reports Server (NTRS)

    Kovach, R. L.; Watkins, J. S.; Talwani, P.

    1972-01-01

    The Apollo 16 active seismic experiment (ASE) was designed to generate and monitor seismic waves for the study of the lunar near-surface structure. Several seismic energy sources are used: an astronaut-activated thumper device, a mortar package that contains rocket-launched grenades, and the impulse produced by the lunar module ascent. Analysis of some seismic signals recorded by the ASE has provided data concerning the near-surface structure at the Descartes landing site. Two compressional seismic velocities have so far been recognized in the seismic data. The deployment of the ASE is described, and the significant results obtained are discussed.

  6. SOURCE PHENOMENOLOGY EXPERIMENTS IN ARIZONA

    SciTech Connect

    Jessie L. Bonner; Brian Stump; Mark Leidig; Heather Hooper; Xiaoning Yang; Rongmao Zhou; Tae Sung Kim; William R. Walter; Aaron Velasco; Chris Hayward; Diane Baker; C. L. Edwards; Steven Harder; Travis Glenn; Cleat Zeiler; James Britton; James F. Lewkowicz

    2005-09-30

    The Arizona Source Phenomenology Experiments (SPE) have resulted in an important dataset for the nuclear monitoring community. The 19 dedicated single-fired explosions and multiple delay-fired mining explosions were recorded by one of the most densely instrumented accelerometer and seismometer arrays ever fielded, and the data have already proven useful in quantifying confinement and excitation effects for the sources. It is very interesting to note that we have observed differences in the phenomenology of these two series of explosions resulting from the differences between the relatively slow (limestone) and fast (granodiorite) media. We observed differences at the two SPE sites in the way the rock failed during the explosions, how the S-waves were generated, and the amplitude behavior as a function of confinement. Our consortium's goal is to use the synergy of the multiple datasets collected during this experiment to unravel the phenomenological differences between the two emplacement media. The data suggest that the main difference between single-fired chemical and delay-fired mining explosion seismograms at regional distances is the increased surface wave energy for the latter source type. The effect of the delay-firing is to decrease the high-frequency P-wave amplitudes while increasing the surface wave energy because of the longer source duration and spall components. The results suggest that the single-fired explosions are surrogates for nuclear explosions in higher frequency bands (e.g., 6-8 Hz Pg/Lg discriminants). We have shown that the SPE shots, together with the mining explosions, are efficient sources of S-wave energy, and our next research stage is to postulate the possible sources contributing to the shear-wave energy.

  7. Activation Experiments for Nuclear Astrophysics

    SciTech Connect

    Sonnabend, K.; Mueller, S.; Pietralla, N.; Savran, D.; Schnorrenberger, L.; Hasper, J.; Zilges, A.

    2009-01-28

    The study of ({gamma},n) reactions can be used to constrain the theoretical predictions of the neutron capture cross sections of short-lived branching points in the s process. The usability of the activation technique to study these ({gamma},n) reactions is discussed as one example of an activation experiment in nuclear astrophysics. Two photon sources using bremsstrahlung and laser-Compton backscattered photons where such experiments were carried out are compared.

  8. Infrasound Generation from the Source Physics Experiments

    NASA Astrophysics Data System (ADS)

    Preston, L. A.; Schramm, K. A.; Jones, K. R.

    2015-12-01

    Understanding the acoustic and infrasound source generation mechanisms from underground explosions is of great importance for usage of this unique data type in non-proliferation activities. One of the purposes of the Source Physics Experiments (SPE), a series of underground explosive shots at the Nevada National Security Site (NNSS), is to gain an improved understanding of the generation and propagation of physical signals, such as seismic and infrasound, from the near to far field. Two of the SPE shots (SPE-1 and SPE-4') were designed to be small "Green's Function" sources with minimal spall or permanent surface deformation. We analyze infrasound data collected from these two shots at distances from ~300 m to ~1 km and frequencies up to 20 Hz. Using weather models based upon actual observations at the times of these sources, including 3-D variations in topography, temperatures, pressures, and winds, we synthesized full waveforms using Sandia's moving media acoustic propagation simulation suite. Several source mechanisms were simulated and compared and contrasted with observed waveforms using full waveform source inversion. We will discuss results of these source inversions including the relative roll of spall from these small explosions. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  9. Characterization of the Source Physics Experiment Site

    NASA Astrophysics Data System (ADS)

    Sussman, A. J.; Schultz-Fellenz, E. S.; Broome, S. T.; Townsend, M.; Abbott, R. E.; Snelson, C. M.; Cogbill, A. H.; Conklin, G.; Mitra, G.; Sabbeth, L.

    2012-12-01

    Designed to improve long-range treaty monitoring capabilities, the Source Physics Experiments, conducted at the Nevada National Security Site, also provide an opportunity to advance near-field monitoring and field-based investigations of suspected underground test locations. In particular, features associated with underground testing can be evaluated using Source Physics Experiment activities as analogs, linking on-site inspections with remote sensing technologies. Following a calibration shot (SPE 1), SPE 2 (10/2011) and SPE 3 (07/2012) were performed in the same emplacement hole with 1.0 ton of explosives at 150 ft depth. Because one of the goals of the Source Physics Experiments is to determine damage effects on seismic wave propagation and improve modeling capabilities, a key component in the predictive component and ultimate validation of the models is a full understanding of the intervening geology between the source and instrumented bore holes. Ground-based LIDAR and fracture mapping, mechanical properties determined via laboratory testing of rock core, discontinuity analysis and optical microscopy of the core rocks were performed prior to and following each experiment. In addition, gravity and magnetic data were collected between SPE 2 and 3. The source region of the explosions was also characterized using cross-borehole seismic tomography and vertical seismic profiling utilizing two sets of two boreholes within 40 meters of ground zero. The two sets of boreholes are co-linear with the explosives hole in two directions. Results of the LIDAR collects from both SPE 2 and 3 indicate a permanent ground displacement of up to several centimeters aligning along the projected surface traces of two faults observed in the core and fractures mapped at the surface. Laboratory testing and optical work show a difference in the characteristics of the rocks below and above 40 feet and within the fault zones.The estimated near-surface densities from the gravity survey show

  10. Extravehicular activity welding experiment

    NASA Technical Reports Server (NTRS)

    Watson, J. Kevin

    1989-01-01

    The In-Space Technology Experiments Program (INSTEP) provides an opportunity to explore the many critical questions which can only be answered by experimentation in space. The objective of the Extravehicular Activity Welding Experiment definition project was to define the requirements for a spaceflight experiment to evaluate the feasibility of performing manual welding tasks during EVA. Consideration was given to experiment design, work station design, welding hardware design, payload integration requirements, and human factors (including safety). The results of this effort are presented. Included are the specific objectives of the flight test, details of the tasks which will generate the required data, and a description of the equipment which will be needed to support the tasks. Work station requirements are addressed as are human factors, STS integration procedures and, most importantly, safety considerations. A preliminary estimate of the cost and the schedule for completion of the experiment through flight and postflight analysis are given.

  11. Compact Photon Source for Polarized Target Experiments

    NASA Astrophysics Data System (ADS)

    Niculescu, Gabriel; Wojtsekhowski, Bogdan

    2017-01-01

    High energy photon beams are one of the tools of choice in nuclear and particle physics. However, most of the current techniques used for producing such beams have substantial drawbacks that limit their usefulness (low intensity, large beam size, mixed electron-photon beams). In this presentation we will outline the design of a Compact Photon Source (CPS) capable of providing narrow ( 1 mm) untagged photon beams of an intensity suitable for carrying out polarized target experiments. Compared with existing technology the CPS will provide a substantial (10-100) increase in the figure-of-merit. While optimized for a Wide Angle Compton Scattering experiment proposed at JLab, the source described here can be used in a variety of photon-induced physics experiments as well as for industrial applications.

  12. Juan de Fuca Plate Ridge-to-Trench Experiment: initial results from active source seismic imaging of the Juan de Fuca plate and Cascadia fore-arc (Invited)

    NASA Astrophysics Data System (ADS)

    Carbotte, S. M.; Canales, J.; Carton, H. D.; Han, S.; Gibson, J. C.; Janiszewski, H. A.; Horning, G.; Nedimovic, M. R.; Abers, G. A.; Trehu, A. M.

    2013-12-01

    Active source seismic data were acquired during the Juan de Fuca Ridge-to-Trench experiment (June-July 2012) to characterize the evolution and structure of the Juan de Fuca plate from formation at the ridge, through evolution in the plate interior, to subduction at the Cascadia trench. The survey provides plate-scale images of the sediments, crust, and shallowest mantle along two ridge-perpendicular transects, one extending from Axial seamount to the Oregon margin near Hydrate Ridge and the other from near Endeavour segment to Grays Harbor offshore Washington. In addition, a 450 km long trench-parallel line ~10 km seaward of the Cascadia deformation front was acquired to characterize variations in plate structure along the margin. Coincident long-streamer (8 km) multi-channel seismic (MCS) and wide-angle ocean bottom seismometer (OBS) data were collected along each transect. Using these data, our current investigations focus on the properties of the thick sediment blanket covering the Juan de Fuca plate and evidence for fluid flow at the deformation front, crustal structure within the plate interior and near the deformation front, and tracking the downgoing plate beneath the margin. Highlights include the discovery of numerous pockmarks on the seafloor providing evidence of active fluid flow up to 60 km west of the deformation front. Along the Oregon transect, a bright decollement horizon is imaged at ~1sec twtt above basement whereas at the Washington margin, protothrusts of the deformation front reach to the top of the oceanic crust. Variations in sediment properties are documented within the margin-parallel transect with changes in the stratigraphic level of decollement. While crustal thickness is quite uniform along the margin (~ 6 km), variations in crustal reflectivity and in shallowest mantle velocities are observed over ~30-50 km length scales that could be related to structural variations in the Cascadia subduction zone. Further landward, the top of the

  13. Polarized Electron Source for the MOLLER Experiment

    NASA Astrophysics Data System (ADS)

    Palatchi, Caryn

    2017-01-01

    The MOLLER experiment at Jefferson Laboratory will be part of a new generation of ultra high precision electroweak experiments. It will measure the Moller (electron-electron scattering) parity-violating asymmetry, providing an unprecedented precision on the electroweak mixing angle. To achieve such small uncertainties, innovative techniques in the electron source are required to switch the beam helicity more quickly than previously achievable. The key technology is the Pockels cell in the laser optics of the polarized electron source. RTP crystals, which do not suffer from piezo-electric ringing, have been demonstrated to achieve almost an order of magnitude faster transition times than commonly used KD*P crystal cells. This talk will detail the design modifications made to the RTP cell in order to achieve beam quality which is comparable to traditional KD*P controlled accelerator beams. The specific challenges for this use of the RTP system, including laser and crystal constraints, will be discussed.

  14. SPALLATION NEUTRON SOURCE OPERATIONAL EXPERIENCE AT 1 MW

    SciTech Connect

    Galambos, John D

    2011-01-01

    The Spallation Neutron Source (SNS) has been operating at the MW level for about one year. Experience in beam loss control and machine activation at this power level is presented. Also experience with machine protection systems is reviewed, which is critical at this power level. One of the most challenging operational aspects of high power operation has been attaining high availability, which is also discussed

  15. A Mine Explosion Source Phenomenology Experiment

    DTIC Science & Technology

    2000-09-01

    Alternatively, if controlled mine blast experiments could be performed, in close collaboration with the mining industry , significant knowledge could be...gleaned to reduce the chance of false alarms from such mining activities and, hopefully, provide the mining industry with useful information to conduct...including both hard and soft rock environments. One of the goals of this effort is to engage the mining industry in a variety of collaborative

  16. Vehicular sources in acoustic propagation experiments

    NASA Technical Reports Server (NTRS)

    Prado, Gervasio; Fitzgerald, James; Arruda, Anthony; Parides, George

    1990-01-01

    One of the most important uses of acoustic propagation models lies in the area of detection and tracking of vehicles. Propagation models are used to compute transmission losses in performance prediction models and to analyze the results of past experiments. Vehicles can also provide the means for cost effective experiments to measure acoustic propagation conditions over significant ranges. In order to properly correlate the information provided by the experimental data and the propagation models, the following issues must be taken into consideration: the phenomenology of the vehicle noise sources must be understood and characterized; the vehicle's location or 'ground truth' must be accurately reproduced and synchronized with the acoustic data; and sufficient meteorological data must be collected to support the requirements of the propagation models. The experimental procedures and instrumentation needed to carry out propagation experiments are discussed. Illustrative results are presented for two cases. First, a helicopter was used to measure propagation losses at a range of 1 to 10 Km. Second, a heavy diesel-powered vehicle was used to measure propagation losses in the 300 to 2200 m range.

  17. CMBACT: CMB from ACTive sources

    NASA Astrophysics Data System (ADS)

    Pogosian, Levon; Vachaspati, Tanmay

    2011-06-01

    This code is based on the cosmic string model described in this paper by Pogosian and Vachaspati, as well as on the CMBFAST code created by Uros Seljak and Matias Zaldarriaga. It contains an integrator for the vector contribution to the CMB temperature and polarization. The code is reconfigured to make it easier to use with or without active sources. To produce inflationary CMB spectra one simply sets the string tension to zero (gmu=0.0d0). For a non-zero value of tension only the string contribution is calculated. An option is added to randomize the directions of velocities of consolidated segments as they evolve in time. In the original segment model, which is still the default version (irandomv=0), each segment is given a random velocity initially, but then continues to move in a straight line for the rest of its life. The new option (irandomv=1) allows to additionally randomize velocities of each segment at roughly each Hubble time. However, the merits of this new option are still under investigation. The default version (irandomv=0) is strongly recommended, since it actually gives reasonable unequal time correlators. For each Fourier mode, k, the string stress-energy components are now evaluated on a time grid sufficiently fine for that k.

  18. Crystal activation experiment MA-151

    NASA Technical Reports Server (NTRS)

    Trombka, J. I.; Eller, E. L.; Schmadebeck, R. L.; Dyer, C. S.; Reedy, R. C.; Barr, D. W.; Gilmore, J. S.; Prestwood, R. J.; Bayhurst, B. P.; Perry, D. G.

    1976-01-01

    The crystal activation experiment consisted of two sample packages that were flown in the command module and returned to earth for analysis of the radioactivity induced in them during the flight. The objective of the experiment was to define the background caused by detector activation that interferes when gamma radiation is measured in the 0.02- to 10-megaelectronvolt range from earth orbit. Preliminary results show that the activation of the NaI(Tl) crystal was a factor of 3 below that from a similar measurement on Apollo 17. The identification of certain species and the level of activation observed show an important contribution from the interactions of thermal and energetic neutrons produced as secondaries in the spacecraft. That the activation was reduced by only a factor of 3 compared with the Apollo 17 experiment, despite the geomagnetically shielded orbit, possibly indicates more efficient secondary neutron production by the more energetic cosmic rays.

  19. Alternative Energy Sources. Experiments You Can Do...from Edison.

    ERIC Educational Resources Information Center

    Benrey, Ronald M.; Schultz, Robert F.

    Eight experiments dealing with alternative energy sources are presented. Each experiment includes an introductory section which provides background information and discusses the promises and problems of the particular energy source, a list of materials needed to complete the experiment, and the procedures to be used. The experiments involve:…

  20. IRIS Controlled Source Seismic Experiments: Continental Structure, Instrumentation, and Education

    NASA Astrophysics Data System (ADS)

    Mooney, W. D.; Keller, G. R.

    2004-12-01

    The controlled-source seismology program of IRIS/PASSCAL has made major contributions to the study of continental structure and evolution. It has also undergone major developments in seismic instrumentation. The first PASSCAL experiments (1984/85) targeted the Basin and Range Province and the Ouachita orogenic belt. The Basin and Range study provided remarkably clear images of this thin, highly-extended crust, while the Ouachita experiment tested competing hypotheses for the deep structure of this Paleozoic orogen. However, both of these projects were limited by a lack of seismic instruments. The situation improved in the late 1980's with the benefit of a mixed array of 600 seismic recorders from the USGS, Stanford, and the Geological Survey of Canada. The resolution achieved with these instruments was revolutionary. Results include the imaging of such remarkable features as crustal-scale duplexes in the Brooks Range compressional orogen of northern Alaska, and of crustal "core complexes" in the extended crust of southwest Arizona. The 3-channel PASSCAL Jr. instrument was developed, leading to experiments in which ˜1000 instruments were deployed, including three-component recording. This complex mix of instruments served the community well for several years, but required large, complex instrument centers and lots of technical support. With input from PASSCAL and the international community, a newly designed, compact instrument (the Texan) was finalized in the spring of 1998, and the first 200 instruments was delivered to the Univ. of Texas-El Paso in late 1998. The present instrument pool of Texans exceeds 1,400 and these have been used on such projects as the high-resolution imaging of the Los Angeles and San Fernando basins (LARSE I and II experiments), where active thrust faults have been imaged. Controlled-source seismic experiments are now very numerous. During calendar year 2004 alone, portable Texan instruments have traveled from Venezuela to Denmark

  1. Gamma source for active interrogation

    DOEpatents

    Leung, Ka-Ngo; Lou, Tak Pui; Barletta, William A.

    2009-09-29

    A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.

  2. Gamma source for active interrogation

    SciTech Connect

    Leung, Ka-Ngo; Lou, Tak Pui; Barletta, William A.

    2012-10-02

    A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.

  3. Romanian Experience in The Conditioning of Radium Sources

    SciTech Connect

    Dogaru, Gh.; Dragolici, F.; Rotarescu, Gh.; Nicu, M.

    2008-07-01

    Ra{sup 226} first radionuclide separated from pitchblende in 1898 by Pierre and Marie Curie was successfully used in medicine, industry as in other fields being the only one available radionuclide till 1940 when were produced other radionuclides in accelerators. On long term the use of Ra{sup 226} sealed sources are not any more safe due to: the high specific activity, long half live, decays in Rn{sup 226} gas which increases the internal pressure of capsule leading in time to the leakage, the salts as raw materials from which the sealed sources are manufactured are soluble, there is a leak of information and records on the manufacture and operation. Based on this consideration in Romania regulatory authority did not authorized any more the use of these sealed sources [1]. The paper presents some aspects from Romanian experience related to the collection and conditioning of radium sealed sources. Data relating the radium inventory as well as the arrangements made in order to create a workshop for the conditioning of radium sources are presented. (authors)

  4. Apollo experience report: Safety activities

    NASA Technical Reports Server (NTRS)

    Rice, C. N.

    1975-01-01

    A description is given of the flight safety experiences gained during the Apollo Program and safety, from the viewpoint of program management, engineering, mission planning, and ground test operations was discussed. Emphasis is placed on the methods used to identify the risks involved in flight and in certain ground test operations. In addition, there are discussions on the management and engineering activities used to eliminate or reduce these risks.

  5. Source physics experiments at the Nevada Test Site.

    SciTech Connect

    Lee, Ping; Snelson, Catherine; Abbott, Robert; Coblentz, David D.; Corbell, Robert; Bowyer, Theodore W.; Sussman, Aviva J.; Carrigan, Charles R.; Bradley, Christopher R.; Patton, Howard J.; Seifert, Carolyn E.; Sweeney, Jerry J.; Brunish, Wendee M.; Hawkins, Ward L.; Antoun,Tarabay H.; Wohletz, Kenneth H.; Zucca, John Jay

    2010-10-01

    The U. S. capability to monitor foreign underground nuclear test activities relies heavily on measurement of explosion phenomena, including characteristic seismic, infrasound, radionuclide, and acoustic signals. Despite recent advances in each of these fields, empirical, rather than physics-based, approaches are used to predict and explain observations. Seismologists rely on prior knowledge of the variations of teleseismic and regional seismic parameters such as p- and s-wave arrivals from simple one-dimensional models for the teleseismic case to somewhat more complicated enhanced two-dimensional models for the regional case. Likewise, radionuclide experts rely on empirical results from a handful of limited experiments to determine the radiological source terms present at the surface after an underground test. To make the next step in the advancement of the science of monitoring we need to transform these fields to enable predictive, physics-based modeling and analysis. The Nevada Test Site Source Physics Experiments (N-SPE) provide a unique opportunity to gather precise data from well-designed experiments to improve physics-based modeling capability. In the seismic experiments, data collection will include time domain reflectometry to measure explosive performance and yield, free-field accelerometers, extensive seismic arrays, and infrasound and acoustic measurements. The improved modeling capability that we will develop using this data should enable important advances in our ability to monitor worldwide for nuclear testing. The first of a series of source physics experiments will be conducted in the granite of Climax Stock at the NTS, near the locations of the HARD HAT and PILE DRIVER nuclear tests. This site not only provides a fairly homogeneous and well-documented geology, but also an opportunity to improve our understanding of how fractures, joints, and faults affect seismic wave generation and propagation. The Climax Stock experiments will consist of a 220

  6. Experiments with radioactive samples at the Advanced Photon Source.

    SciTech Connect

    Veluri, V. R.; Justus, A.; Glagola, B.; Rauchas, A.; Vacca, J.

    2000-11-01

    The Advanced Photon Source (APS) at Argonne National Laboratory is a national synchrotron-radiation light source research facility. The 7 GeV electron Storage Ring is currently delivering intense high brilliance x-ray beams to a total of 34 beamlines with over 120 experiment stations to members of the international scientific community to carry out forefront basic and applied research in several scientific disciplines. Researchers come to the APS either as members of Collaborative Access Teams (CATs) or as Independent Investigators (IIs). Collaborative Access Teams comprise large number of investigators from universities, industry, and research laboratories with common research objectives. These teams are responsible for the design, construction, finding, and operation of beamlines. They are the owners of their experimental enclosures (''hutches'') designed and built to meet their specific research needs. Fig. 1 gives a plan view of the location of the Collaborative Access Teams by Sector and Discipline. In the past two years, over 2000 individual experiments were conducted at the APS facility. Of these, about 60 experiments involved the use of radioactive samples, which is less than 3% of the total. However, there is an increase in demand for experiment stations to accommodate the use of radioactive samples in different physical forms embedded in various matrices with activity levels ranging from trace amounts of naturally occurring radionuclides to MBq (mCi) quantities including transuranics. This paper discusses in some detail the steps in the safety review process for experiments involving radioactive samples and how ALARA philosophy is invoked at each step and implemented.

  7. Laser ion source for isobaric heavy ion collider experiment

    SciTech Connect

    Kanesue, T. Okamura, M.; Kumaki, M.; Ikeda, S.

    2016-02-15

    Heavy-ion collider experiment in isobaric system is under investigation at Relativistic Heavy Ion Collider. For this experiment, ion source is required to maximize the abundance of the intended isotope. The candidate of the experiment is {sup 96}Ru + {sup 96}Zr. Since the natural abundance of particular isotope is low and composition of isotope from ion source depends on the composites of the target, an isotope enriched material may be needed as a target. We studied the performance of the laser ion source required for the experiment for Zr ions.

  8. Laser ion source for isobaric heavy ion collider experiment.

    PubMed

    Kanesue, T; Kumaki, M; Ikeda, S; Okamura, M

    2016-02-01

    Heavy-ion collider experiment in isobaric system is under investigation at Relativistic Heavy Ion Collider. For this experiment, ion source is required to maximize the abundance of the intended isotope. The candidate of the experiment is (96)Ru + (96)Zr. Since the natural abundance of particular isotope is low and composition of isotope from ion source depends on the composites of the target, an isotope enriched material may be needed as a target. We studied the performance of the laser ion source required for the experiment for Zr ions.

  9. Advanced Light Source Activity Report 2000

    SciTech Connect

    Greiner, A.; Moxon, L.; Robinson, A.; Tamura, L.

    2001-04-01

    This is an annual report, detailing activities at the Advanced Light Source for the year 2000. It includes highlights of scientific research by users of the facility as well as information about the development of the facility itself.

  10. Investigation on RGB laser source applied to dynamic photoelastic experiment

    NASA Astrophysics Data System (ADS)

    Li, Songgang; Yang, Guobiao; Zeng, Weiming

    2014-06-01

    When the elastomer sustains the shock load or the blast load, its internal stress state of every point will change rapidly over time. Dynamic photoelasticity method is an experimental stress analysis method, which researches the dynamic stress and the stress wave propagation. Light source is one of very important device in dynamic photoelastic experiment system, and the RGB laser light source applied in dynamic photoelastic experiment system is innovative and evolutive to the system. RGB laser is synthesized by red laser, green laser and blue laser, either as a single wavelength laser light source, also as synthesized white laser light source. RGB laser as a light source for dynamic photoelastic experiment system, the colored isochromatic can be captured in dynamic photoelastic experiment, and even the black zero-level stripe can be collected, and the isoclinics can also be collected, which conducively analysis and study of transient stress and stress wave propagation. RGB laser is highly stable and continuous output, and its power can be adjusted. The three wavelengths laser can be synthesized by different power ratio. RGB laser light source used in dynamic photoelastic experiment has overcome a number of deficiencies and shortcomings of other light sources, and simplifies dynamic photoelastic experiment, which has achieved good results.

  11. Initial experiments of RF gas plasma source for heavy ionfusion

    SciTech Connect

    Ahle, L.; Hall, R.; Molvik, A.W.; Chacon-Golcher, E.; Kwan, J.W.; Leung, K.N.; Reijonen, J.

    2002-05-22

    The Source Injector Program for the US Heavy Ion Fusion Virtual National Laboratory is currently exploring the feasibility of using RF gas plasma sources for a HIF driver. This source technology is presently the leading candidate for the multiple aperture concept, in which bright millimeter size beamlets are extracted and accelerated electrostatically up to 1 MeV before the beamlets are allowed to merge and form 1 A beams. Initial experiments have successfully demonstrated simultaneously high current density, {approx} 100 mA/cm{sup 2} and fast turn on, {approx} 1 {micro}s. These experiments were also used to explore operating ranges for pressure and RF power. Results from these experiments are presented as well as progress and plans for the next set of experiments for these sources.

  12. Neutron calibration sources in the Daya Bay experiment

    DOE PAGES

    Liu, J.; Carr, R.; Dwyer, D. A.; ...

    2015-07-09

    We describe the design and construction of the low rate neutron calibration sources used in the Daya Bay Reactor Anti-neutrino Experiment. Such sources are free of correlated gamma-neutron emission, which is essential in minimizing induced background in the anti-neutrino detector. Thus, the design characteristics have been validated in the Daya Bay anti-neutrino detector.

  13. Preliminary results from the {sup 51}Cr neutrino source experiment in GALLEX

    SciTech Connect

    Hampel, W.; Heusser, G.; Kiko, J.

    1996-09-01

    The GALLEX collaboration performed a second {sup 51}Cr neutrino source experiment during fall 1995. The full results from this second source experiment will not be available before the end of 1996. Meanwhile, we present a short description and preliminary results in this informal note. The (preliminary) value of the activity obtained form direct measurements has been found equal to (68.7 {+-}0.7) PBq (with 1-sigma error). This value, which is about 10% higher than the activity of the first source, was achieved by optimizing the irradiation conditions in the Silo{acute e} reactor and doing a longer irradiation of the enriched chromium. Preliminary results show that the ratio, R, of the radiochemically determined activity from {sup 71}Ge counting (57.1 {+-} PBq) to the directly measured activity is (0.83 {+-} 0.10). The combined value of R for the two source experiments is (0.92 {+-} 0.08).

  14. The Burst and Transient Source Experiment (BATSE) Earth Occultation Catalog

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, Colleen A.

    2004-01-01

    The hard X-ray sky was continuously monitored with the BATSE experiment on the Compton Gamma Ray observatory using the Earth Occultation method. Known sources were monitored twice every orbit and transients could be detected at about the approx. 50 mCrab level on a daily basis. I will summarize the results from our catalog of 179 monitored sources, highlighting observations of black holes and energy spectra for the 83 firmly detected sources and FITS files for all 179 sources. This web database can serve as a guide and comparison tool for future observations with EXIST.

  15. Fundamental-mode sources in approach-to-critical experiments

    SciTech Connect

    Goda, J.; Busch, R.

    2000-05-01

    The 1/M method is commonly used in approach-to-critical experiments to ensure criticality safety. Ideally, a plot of 1/M versus amount of nuclear material or separation distance will be linear. However, the result is usually a curve. If the curve is concave up it is said to be conservative, since the critical mass is underestimated. However, it is possible for the curve to be non-conservative and overestimate the critical mass. This paper discusses one of the factors contributing to the shape of the 1/M curve and how it can be predicted and measured. Two source distributions, producing the same number of spontaneous fission neutrons, will not necessarily contribute equally towards the multiplication of a given system. For this reason equally sized units added during an approach-to-critical will have different effects on the multiplication of the system. A method of denoting the relative importance of source distributions is needed. One method is to compare any given source distribution to its equivalent fundamental-mode source distribution. An equivalent fundamental-mode source is an imaginary source distributed identically in space, energy, and angle to the fundamental-mode fission source that would produce the same neutron multiplication as the given source distribution. A factor, denoted as g* and defined as the ratio of the fixed-source multiplication to the fundamental-mode multiplication, is used to relate a given source strength to its equivalent fundamental-mode source strength (Spriggs, et al., 1999).

  16. Optimal Experience of Web Activities.

    ERIC Educational Resources Information Center

    Chen, Hsiang; Wigand, R. T.; Nilan, M. S.

    1999-01-01

    Reports on Web users' optimal flow experiences to examine positive aspects of Web experiences that could be linked to theory applied to other media and then incorporated into Web design. Discusses the use of content-analytic procedures to analyze open-ended questionnaires that examined Web users' perceived flow experiences. (Author/LRW)

  17. Methodology for a bounding estimate of activation source-term.

    PubMed

    Culp, Todd

    2013-02-01

    Sandia National Laboratories' Z-Machine is the world's most powerful electrical device, and experiments have been conducted that make it the world's most powerful radiation source. Because Z-Machine is used for research, an assortment of materials can be placed into the machine; these materials can be subjected to a range of nuclear reactions, producing an assortment of activation products. A methodology was developed to provide a systematic approach to evaluate different materials to be introduced into the machine as wire arrays. This methodology is based on experiment specific characteristics, physical characteristics of specific radionuclides, and experience with Z-Machine. This provides a starting point for bounding calculations of radionuclide source-term that can be used for work planning, development of work controls, and evaluating materials for introduction into the machine.

  18. NATIONAL SYNCHROTRON LIGHT SOURCE ACTIVITY REPORT 1998.

    SciTech Connect

    ROTHMAN,E.

    1999-05-01

    In FY 1998, following the 50th Anniversary Year of Brookhaven National Laboratory, Brookhaven Science Associates became the new Managers of BNL. The new start is an appropriate time to take stock of past achievements and to renew or confirm future goals. During the 1998 NSLS Annual Users Meeting (described in Part 3 of this Activity Report), the DOE Laboratory Operations Board, Chaired by the Under Secretary for Energy, Ernest Moniz met at BNL. By chance all the NSLS Chairmen except Martin Blume (acting NSLS Chair 84-85) were present as recorded in the picture. Under their leadership the NSLS has improved dramatically: (1) The VUV Ring current has increased from 100 mA in October 1982 to nearly 1 A today. For the following few years 10 Ahrs of current were delivered most weeks - NSLS now exceeds that every day. (2) When the first experiments were performed on the X-ray ring during FY1985 the electron energy was 2 GeV and the current up to 100 mA - the X-Ray Ring now runs routinely at 2.5 GeV and at 2.8 GeV with up to 350 mA of current, with a very much longer beam half-life and improved reliability. (3) Starting in FY 1984 the proposal for the Phase II upgrade, mainly for a building extension and a suite of insertion devices and their associated beamlines, was pursued - the promises were delivered in full so that for some years now the NSLS has been running with two undulators in the VUV Ring and three wigglers and an undulator in the X-Ray Ring. In addition two novel insertion devices have been commissioned in the X13 straight. (4) At the start of FY 1998 the NSLS welcomed its 7000th user - attracted by the opportunity for pursuing research with high quality beams, guaranteed not to be interrupted by 'delivery failures', and welcomed by an efficient and caring user office and first class teams of PRT and NSLS staff. R & D have lead to the possibility of running the X-Ray Ring at the higher energy of 2.8 GeV. Figure 1 shows the first user beam, which was provided

  19. Environmental Pollution, Teacher's Manual (Experiences/Experiments/Activities).

    ERIC Educational Resources Information Center

    Weaver, Elbert C.

    Described in this teacher's guide are numerous experiments teachers may use to guide students in learning about community environmental problems. Experiments are relatively simple and useful in the junior high school grades. Activities allow the student to become acquainted with the methods for the detection and removal of undesirable materials…

  20. Environmental Pollution, Student's Book (Experiences/Experiments/Activities).

    ERIC Educational Resources Information Center

    Weaver, Elbert C.

    Described in this student's manual are numerous experiments to acquaint the learner with community environmental problems. Experiments are relatively simple and useful in the junior high school grades. Activities are provided which emphasize some of the materials involved in pollution problems, such as carbon dioxide, sulfur compounds, and others,…

  1. Experience of disused source management in Latin America

    SciTech Connect

    Pimenta Mourao, R.

    2008-07-01

    The Centro de Desenvolvimento da Tecnologia Nuclear (Center for the Development of Nuclear Technology) - CDTN - has been actively engaged in cooperation programs for disused source management throughout the Latin American and the Caribbean region since 1996. The CDTN source conditioning team participated in the preparation of the technical procedures established for the different tasks involved in the radium sources conditioning operations, like preparation of the packaging for conditioning; sources conditioning; capsule welding; leak test in radium-containing capsule; and radiation protection planning for the conditioning of disused radium sources. The team also carried out twelve radium sources conditioning operation in the region, besides in-house operations, which resulted in a total conditioned activity of approximately 525 GBq, or 14,200 mg of radium. Additionally, one operation was carried out in Nicaragua to safely condition three Cobalt teletherapy heads stored under very precarious conditions in the premises of an old hospital. More recently, the team started its participation in an IAEA- and US State Department-sponsored program for the repatriation of disused or excess transuranic sources presently stored at users' premises or under regulatory control in different countries in the region. In September 2007 the team attended a theoretical and practical training in transuranic sources management, including the participation in the conditioning of different neutron sources in certified packages. It is expected that the trained team will carry out similar operations in other Latin American countries. Finally, the team is expected be involved in the near future in the repatriation of US-origin teletherapy heads and industrial gauges. (authors)

  2. Ion source issues for the DAEδALUS neutrino experiment

    SciTech Connect

    Alonso, Jose R. Barletta, William A.; Toups, Matthew H.; Conrad, Janet; Liu, Y.; Bannister, Mark E.; Havener, C. C.; Vane, Randy

    2014-02-15

    The DAEδALUS experiment calls for 10 mA of protons at 800 MeV on a neutrino-producing target. To achieve this record-setting current from a cyclotron system, H{sub 2}{sup +} ions will be accelerated. Loosely bound vibrationally excited H{sub 2}{sup +} ions inevitably produced in conventional ion sources will be Lorentz stripped at the highest energies. Presence of these states was confirmed at the Oak Ridge National Laboratory and strategies were investigated to quench them, leading to a proposed R and D effort towards a suitable ion source for these high-power cyclotrons.

  3. Ion source issues for the DAEδALUS neutrino experiment.

    PubMed

    Alonso, Jose R; Barletta, William A; Toups, Matthew H; Conrad, Janet; Liu, Y; Bannister, Mark E; Havener, C C; Vane, Randy

    2014-02-01

    The DAEδALUS experiment calls for 10 mA of protons at 800 MeV on a neutrino-producing target. To achieve this record-setting current from a cyclotron system, H2 (+) ions will be accelerated. Loosely bound vibrationally excited H2 (+) ions inevitably produced in conventional ion sources will be Lorentz stripped at the highest energies. Presence of these states was confirmed at the Oak Ridge National Laboratory and strategies were investigated to quench them, leading to a proposed R&D effort towards a suitable ion source for these high-power cyclotrons.

  4. Lunar seismic profiling experiment natural activity study

    NASA Technical Reports Server (NTRS)

    Duennebier, F. K.

    1976-01-01

    The Lunar Seismic Experiment Natural Activity Study has provided a unique opportunity to study the high frequency (4-20 Hz) portion to the seismic spectrum on the moon. The data obtained from the LSPE was studied to evaluate the origin and importance of the process that generates thermal moonquakes and the characteristics of the seismic scattering zone at the lunar surface. The detection of thermal moonquakes by the LSPE array made it possible to locate the sources of many events and determine that they are definitely not generated by astronaut activities but are the result of a natural process on the moon. The propagation of seismic waves in the near-surface layers was studied in a qualitative manner. In the absence of an adequate theoretical model for the propagation of seismic waves in the moon, it is not possible to assign a depth for the scattering layer. The LSPE data does define several parameters which must be satisfied by any model developed in the future.

  5. An experiment on the color rendering of different light sources

    NASA Astrophysics Data System (ADS)

    Fumagalli, Simonetta; Bonanomi, Cristian; Rizzi, Alessandro

    2013-02-01

    The color rendering index (CRI) of a light source attempts to measure how much the color appearance of objects is preserved when they are illuminated by the given light source. This problem is of great importance for various industrial and scientific fields, such as lighting architecture, design, ergonomics, etc. Usually a light source is specified through the Correlated Color Temperature or CCT. However two (or more) light sources with the same CCT but different spectral power distribution can exist. Therefore color samples viewed under two light sources with equal CCTs can appear different. Hence, the need for a method to assess the quality of a given illuminant in relation to color. Recently CRI has had a renewed interest because of the new LED-based lighting systems. They usually have a color rendering index rather low, but good preservation of color appearance and a pleasant visual appearance (visual appeal). Various attempts to develop a new color rendering index have been done so far, but still research is working for a better one. This article describes an experiment performed by human observers concerning the appearance preservation of color under some light sources, comparing it with a range of available color rendering indices.

  6. FAME: freeform active mirror experiment

    NASA Astrophysics Data System (ADS)

    Aitink-Kroes, Gabby; Agócs, Tibor; Miller, Chris; Black, Martin; Farkas, Szigfrid; Lemared, Sabri; Bettonvil, Felix; Montgomery, David; Marcos, Michel; Jaskó, Attila; van Duffelen, Farian; Challita, Zalpha; Fok, Sandy; Kiaeerad, Fatemeh; Hugot, Emmanuel; Schnetler, Hermine; Venema, Lars

    2016-07-01

    FAME is a four-year project and part of the OPTICON/FP7 program that is aimed at providing a breakthrough component for future compact, wide field, high resolution imagers or spectrographs, based on both Freeform technology, and the flexibility and versatility of active systems. Due to the opening of a new parameter space in optical design, Freeform Optics are a revolution in imaging systems for a broad range of applications from high tech cameras to astronomy, via earth observation systems, drones and defense. Freeform mirrors are defined by a non-rotational symmetry of the surface shape, and the fact that the surface shape cannot be simply described by conicoids extensions, or off-axis conicoids. An extreme freeform surface is a significantly challenging optical surface, especially for UV/VIS/NIR diffraction limited instruments. The aim of the FAME effort is to use an extreme freeform mirror with standard optics in order to propose an integrated system solution for use in future instruments. The work done so far concentrated on identification of compact, fast, widefield optical designs working in the visible, with diffraction limited performance; optimization of the number of required actuators and their layout; the design of an active array to manipulate the face sheet, as well as the actuator design. In this paper we present the status of the demonstrator development, with focus on the different building blocks: an extreme freeform thin face sheet, the active array, a highly controllable thermal actuator array, and the metrology and control system.

  7. Angular response calibration of the burst and transient source experiment

    NASA Technical Reports Server (NTRS)

    Lestrade, John Patrick

    1988-01-01

    The Gamma Ray Observatory includes four experiments designed to observe the gamma-ray universe. Laboratory measurements to test the response the Burst and Transient Source Experiment (BATSE) modules to gamma-ray sources that are non-axial were recently completed. The results of these observations are necessary for the correct interpretation of BATSE data obtained after it is put in Earth orbit. The launch is planned for March, 1900. Preliminary analyses of these test data show the presence of a radial dependence to the detector's light collection efficiency. It is proposed to evaluate the importance of this radial response, analyze future experimental data to derive the actual functional dependence on radius, and calculate the net effect on the output spectrum as a function of the angle of incidence.

  8. Target Operational Experience at the Spallation Neutron Source

    SciTech Connect

    Riemer, Bernie; Janney, Jim G; Kaminskas, Saulius; McClintock, David A; Rosenblad, Peter M

    2013-01-01

    The Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory (ORNL) has operated at unprecedented power levels for a short-pulse spallation source. Target operations have been successful but not without difficulties. Three targets out of the eight used to date have ended life unexpectedly causing interruptions to the neutron science users. The first of a kind mercury target design experiences beam-pulse induced cavitation damage that is suspected in one of the target leaks. The two other targets suffered early failures due to defective welds. Diagnosing the causes of target leaks and understanding of the progression of cavitation erosion and radiation damage effects has made use of post-irradiation examination (PIE) capabilities. As a result of PIE, review of quality assurance practices and related investigations, design changes are being implemented and manufacturing oversight improved. This paper describes SNS target operating experience, including the more important observations and lessons learned.

  9. Management of Spent and Disused Radiation Sources - The Zambian Experience

    SciTech Connect

    Chabala, F.

    2002-02-26

    Zambia like all other countries in the world is faced with environmental problems brought about by a variety of human activities. In Zambia the major environmental issues as identified by Nation Environmental Action Plan (NEAP) of 1994 are water pollution, poor sanitation, land degradation, air pollution, poor waste management, misuse of chemicals, wildlife depletion and deforestation. Zambian has been using a lot of radioactive materials in its various industries. The country has taken several projects with help of external partners. These partners however left these projects in the hands of the Zambians without developing their capacities to manage these radioactive sources. The Government recognized the need to manage these sources and passed legislation governing the management of radioactive materials. The first act of Parliament on Radiation Protection work was passed in 1975 to legislate the use of ionizing radiation. However, because of financial constraints the Country is facing, these regulations have remained unimplemented. Fortunately the international Community has been working in partnership with the Zambian Government in the Management of Radioactive Material. Therefore this paper will present the following aspects of radioactive waste management in Zambia: review Existing Legislation in Zambia regarding management of spent/radioactive sources; capacity building in the field of management of radioactive waste; management of spent and disused radiation sources; existing disposal systems in Zambia regarding spent/orphaned sources; existing stocks of radioactive sources in the Zambian industries.

  10. The Burst and Transient Source Experiment Earth Occultation Technique

    NASA Technical Reports Server (NTRS)

    Harmon, B. A.; Fishman, G. J.; Wilson, C. A.; Paciesas, W. S.; Zhang, S. N.; Finger, M. H.; Koshut, T. M.; McCollough, M. L.; Robinson, C. R.; Rubin, B. C.

    2002-01-01

    An Earth orbiting detector sensitive to gamma-ray photons will see step-like occultation features in its count rate when a gamma-ray point source crosses the Earth's limb. This is due to the change in atmospheric attenuation of the gamma rays along the line of sight. In an uncollimated detector, these occultation features can be used to locate and monitor astrophysical sources provided their signals can be individually separated from the detector background. We show that the Earth occultation technique applied to the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory (CGRO) is a viable and flexible all-sky monitor in the low-energy gamma-ray and hard X-ray energy range (20 keV-1 MeV). The method is an alternative to more sophisticated photon imaging devices for astronomy and can serve well as a cost-effective science capability for monitoring the high energy sky. Here we describe the Earth occultation technique for locating new sources and for measuring source intensity and spectra without the use of complex background models. Examples of transform imaging, step searches, spectra, and light curves are presented. Systematic uncertainties due to source confusion, detector response, and contamination from rapid background fluctuations are discussed and analyzed for their effect on intensity measurements. A sky location-dependent average systematic error is derived as a function of Galactic coordinates. The sensitivity of the technique is derived as a function of incident photon energy and also as a function of angle between the source and the normal to the detector entrance window. Occultations of the Crab Nebula by the Moon are used to calibrate Earth occultation flux measurements independent of possible atmospheric scattering effects.

  11. Reanalysis of the GALLEX solar neutrino flux and source experiments

    NASA Astrophysics Data System (ADS)

    Kaether, F.; Hampel, W.; Heusser, G.; Kiko, J.; Kirsten, T.

    2010-02-01

    After the completion of the gallium solar neutrino experiments at the Laboratori Nazionali del Gran Sasso (GALLEX: 1991-1997; GNO: 1998-2003) we have retrospectively updated the GALLEX results with the help of new technical data that were impossible to acquire for principle reasons before the completion of the low rate measurement phase (that is, before the end of the GNO solar runs). Subsequent high rate experiments have allowed the calibration of absolute internal counter efficiencies and of an advanced pulse shape analysis for counter background discrimination. The updated overall result for GALLEX (only) is 73.4-7.3+7.1 SNU. This is 5.3% below the old value of 77.5-7.8+7.5 SNU (GALLEX Collaboration, W. Hampel et al., 1999 [1]), with a substantially reduced error. A similar reduction is obtained from the reanalysis of the 51Cr neutrino source experiments of 1994/1995.

  12. The Burst and Transient Source Experiment (BATSE) Earth Occultation Catalog of Low-Energy Gamma-Ray Sources

    NASA Technical Reports Server (NTRS)

    Harmon, B. A.; Wilson, C. A.; Fishman, G. J.; Connaughton, V.; Henze, W.; Paciesas, W. S.; Finger, M. H.; McCollough, M. L.; Sahi, M.; Peterson, B.

    2004-01-01

    The Burst and Transient Source Experiment (BATSE), aboard the Compton Gamma Ray Observatory (CGRO), provided a record of the low-energy gamma-ray sky (approx. 20-1000 keV) between 1991 April and 2000 May (9.1 yr). BATSE monitored the high-energy sky using the Earth occultation technique (EOT) for point sources whose emission extended for times on the order of the CGRO orbital period (approx. 92 min) or greater. Using the EOT to extract flux information, a catalog of sources using data from the BATSE Large Area Detectors has been prepared. The first part of the catalog consists of results from the all-sky monitoring of 58 sources, mostly Galactic, with intrinsic variability on timescales of hours to years. For these sources, we have included tables of flux and spectral data, and outburst times for transients. Light curves (or flux histories) have been placed on the World Wide Web. We then performed a deep sampling of these 58 objects, plus a selection of 121 more objects, combining data from the entire 9.1 yr BATSE data set. Source types considered were primarily accreting binaries, but a small number of representative active galaxies, X-ray-emitting stars, and supernova remnants were also included. The sample represents a compilation of sources monitored and/or discovered with BATSE and other high-energy instruments between 1991 and 2000, known sources taken from the HEAO 1 A-4 and Macomb & Gehrels catalogs. The deep sample results include definite detections of 83 objects and possible detections of 36 additional objects. The definite detections spanned three classes of sources: accreting black hole and neutron star binaries, active galaxies, and Supernova remnants. The average fluxes measured for the fourth class, the X-ray emitting stars, were below the confidence limit for definite detection.

  13. Patient experience of source isolation: lessons for clinical practice.

    PubMed

    Barratt, Ruth Linda; Shaban, Ramon; Moyle, Wendy

    2011-10-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is now the leading antimicrobial-resistant organism of concern to clinicians worldwide. Preventing and controlling the increase and spread of MRSA within the health-care environment is therefore an important function of the infection control team. The prevention and control of MRSA requires strict use of both Standard and Additional Precautions, which include good hand hygiene practices, judicious antimicrobial prescribing, and source isolation. While few would dispute the need for these precautions for preventing the spread of MRSA and other infections, their use may result in adverse physical and psychological effects for the patient. In an age of quality and safety of health care, ensuring infection control practice such as source isolation and contact precautions adhere to fundamental human rights is paramount. This paper presents a review of the literature on the patient experience of source isolation for MRSA or other infectious diseases. The review yielded five major interconnected themes: (1) psychological effects of isolation; (2) coping with isolation; (3) social isolation; (4) communication and information provision; and (5) physical environment and quality of care. It found that the experience of isolation by patients has both negative and positive elements. Isolation may result in detrimental psychological effects including anxiety, stress and depression, but may also result in the patient receiving less or substandard care. However, patients may also benefit from the quietness and privacy of single rooms. Nurses and other healthcare workers must look for ways to improve the experience of isolation and contact precautions of patients in source isolation. Opportunities exist in particular in improving the environment and the patient's self-control of the situation and in providing adequate information.

  14. Advanced light source. Activity report 1995

    SciTech Connect

    1996-07-01

    The ALS Activity Report is designed to share the breadth, variety, and interest of the scientific program and ongoing R&D efforts in a form that is accessible to a broad audience. Recent research results are presented in six sections, each representing an important theme in ALS science. These results are designed to demonstrate the capabilities of the ALS, rather than to give a comprehensive review of 1995 experiments. Although the scientific program and facilities report are separate sections, in practice the achievements and accomplishments of users and ALS staff are interdependent. This user-staff collaboration is essential to help us direct our efforts toward meeting the needs of the user community, and to ensure the continued success of the ALS as a premier facility.

  15. A Multipurpose LED Light Source for Optics Experiments

    NASA Astrophysics Data System (ADS)

    Mak, Se-yuen

    2004-12-01

    The traditional light source for studying lenses and mirrors is either a bare white light bulb, or one encased inside a lamphouse.2, 3 A simple pattern like an arrow, mounted on an optical bench or printed on the window of a lamphouse, serves as the object. Ironically, the image captured on a translucent screen is often the shadow of the pattern with no light falling on it. Although LEDs have been used in commercial display boards for decades, the advantage of using LEDs as a multipurpose light source in the physics laboratory has been overlooked by many physics teachers. In this paper, we remind readers of a few examples of how LEDs can be used to replace the incandescent lamp for geometrical optics, physical optics, and fiber optics experiments.

  16. Techniques for Source-Region EMP Experiments at AURORA

    DTIC Science & Technology

    1983-02-01

    field is uni- For a typicAl A1IRUPA sensor, V 0nsr LA u 3 p l ThCA 1 ore in.ý - 7777W,.t---7 -77 - " Also, if interference in the output cable is...HDL-CR-83-072-1 SFebruary 1983 - Techniques for Source-Region EMP Experiments at AURORA by V. A . J. van Lint Prepared by Mission Research...NUMSERPe) HDL Contact: V. A . J. van Lint William Scharf DMAK21-80-R-9072 9. P~ERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT, PROJECT. TASK

  17. Development of the Burst and Transient Source Experiment (BATSE)

    NASA Technical Reports Server (NTRS)

    Horack, J. M.

    1991-01-01

    The Burst and Transient Source Experiment (BATSE), one of four instruments on the Gamma Ray Observatory, consists of eight identical detector modules mounted on the corners of the spacecraft. Developed at MSFC, BATSE is the most sensitive gamma ray burst detector flown to date. Details of the assembly and test phase of the flight hardware development are presented. Results and descriptions of calibrations performed at MSFC, TRW, and KSC are documented extensively. With the presentation of each calibration results, the reader is provided with the means to access raw calibration data for further review or analysis.

  18. Characteristics of releases from TREAT source term experiment STEP-3

    SciTech Connect

    Fink, J.K.; Schlenger, B.J.; Baker, L. Jr.; Ritzman, R.L.

    1987-01-01

    Four in-pile experiments designed to characterize the radiological source term associated with postulated severe light water reactor accidents were performed at the Transient Reactor Test Facility. STEP-3 simulated a high-pressure TMLB' pressurized water reactor accident sequence that includes the extended loss of all ac power and leads to the loss of long-term decay heat removal. In STEP-3, four fuel elements from the Belgonucleaire BR3 reactor were subjected to temperature and pressures approaching those of a TMLB' accident. A description of the experiment and thermal-hydraulic analysis is reported elsewhere. The aerosols released into the flow stream were collected on coupons, settling plates, and wire impactors. Examination of the collected aerosol deposits was performed using scanning electron microscopy, electron microprobe microanalysis, and secondary ion mass spectroscopy (SIMS), to provide information about the chemical composition and morphology of the release. This paper describes the aerosol deposits and elemental composition of the release.

  19. Open-source products for a lighting experiment device.

    PubMed

    Gildea, Kevin M; Milburn, Nelda

    2014-12-01

    The capabilities of open-source software and microcontrollers were used to construct a device for controlled lighting experiments. The device was designed to ascertain whether individuals with certain color vision deficiencies were able to discriminate between the red and white lights in fielded systems on the basis of luminous intensity. The device provided the ability to control the timing and duration of light-emitting diode (LED) and incandescent light stimulus presentations, to present the experimental sequence and verbal instructions automatically, to adjust LED and incandescent luminous intensity, and to display LED and incandescent lights with various spectral emissions. The lighting device could easily be adapted for experiments involving flashing or timed presentations of colored lights, or the components could be expanded to study areas such as threshold light perception and visual alerting systems.

  20. The catalog of sources for geodetic VLBI from experiments which Kashima station participated in.

    NASA Astrophysics Data System (ADS)

    Takahashi, Y.

    Kashima station participated in many VLBI experiments such as CDP network experiments, JPL network experiments, Japan-Australia-Hawaii experiments and domestic experiments in Japan. Many sources have been observed in these experiments. The correlation amplitude both on a long (several thousand km) and short baseline (several 10 km), source positions and the resolution of the source structure have been obtained. The source positions define a celestial reference frame for the astrometry.

  1. Metabolic Activity - Skylab Experiment M171

    NASA Technical Reports Server (NTRS)

    1972-01-01

    This chart details Skylab's Metabolic Activity experiment (M171), a medical evaluation facility designed to measure astronauts' metabolic changes while on long-term space missions. The experiment obtained information on astronauts' physiological capabilities and limitations and provided data useful in the design of future spacecraft and work programs. Physiological responses to physical activity was deduced by analyzing inhaled and exhaled air, pulse rate, blood pressure, and other selected variables of the crew while they performed controlled amounts of physical work with a bicycle ergometer. The Marshall Space Flight Center had program responsibility for the development of Skylab hardware and experiments.

  2. A numerical experiment on light pollution from distant sources

    NASA Astrophysics Data System (ADS)

    Kocifaj, M.

    2011-08-01

    To predict the light pollution of the night-time sky realistically over any location or measuring point on the ground presents quite a difficult calculation task. Light pollution of the local atmosphere is caused by stray light, light loss or reflection of artificially illuminated ground objects or surfaces such as streets, advertisement boards or building interiors. Thus it depends on the size, shape, spatial distribution, radiative pattern and spectral characteristics of many neighbouring light sources. The actual state of the atmospheric environment and the orography of the surrounding terrain are also relevant. All of these factors together influence the spectral sky radiance/luminance in a complex manner. Knowledge of the directional behaviour of light pollution is especially important for the correct interpretation of astronomical observations. From a mathematical point of view, the light noise or veil luminance of a specific sky element is given by a superposition of scattered light beams. Theoretical models that simulate light pollution typically take into account all ground-based light sources, thus imposing great requirements on CPU and MEM. As shown in this paper, a contribution of distant sources to the light pollution might be essential under specific conditions of low turbidity and/or Garstang-like radiative patterns. To evaluate the convergence of the theoretical model, numerical experiments are made for different light sources, spectral bands and atmospheric conditions. It is shown that in the worst case the integration limit is approximately 100 km, but it can be significantly shortened for light sources with cosine-like radiative patterns.

  3. Characterizing source confusion in HI spectral line stacking experiments

    NASA Astrophysics Data System (ADS)

    Baker, Andrew J.; Elson, Edward C.; Blyth, Sarah

    2017-01-01

    Forthcoming studies like the Looking At the Distant Universe with the MeerKAT Array (LADUMA) deep HI survey will rely in part on stacking experiments to detect the mean level of HI emission from populations of galaxies that are too faint to be detected individually. Preparations for such experiments benefit from the use of synthetic data cubes built from mock galaxy catalogs and containing model galaxies with realistic spatial and spectral HI distributions over large cosmological volumes. I will present a new set of such synthetic data cubes and show the results of stacking experiments with them. Because the stacked spectra can be accurately decomposed into contributions from target and non-target galaxies, it is possible to characterize the large fractions of contaminant mass that are included in stacked totals due to source confusion. Consistent with estimates extrapolated from z = 0 observational data, we find that the amount of confused mass in a stacked spectrum grows almost linearly with the size of the observational beam, suggesting potential overestimates of the cosmic neutral gas density by some recent HI stacking experiments.

  4. Enzyme Activity Experiments Using a Simple Spectrophotometer

    ERIC Educational Resources Information Center

    Hurlbut, Jeffrey A.; And Others

    1977-01-01

    Experimental procedures for studying enzyme activity using a Spectronic 20 spectrophotometer are described. The experiments demonstrate the effect of pH, temperature, and inhibitors on enzyme activity and allow the determination of Km, Vmax, and Kcat. These procedures are designed for teaching large lower-level biochemistry classes. (MR)

  5. Radial response of the burst and transient source experiment

    NASA Technical Reports Server (NTRS)

    Lestrade, John Patrick

    1989-01-01

    The Gamma Ray Observatory (GRO) includes four experiments designed for observe the gamma-ray universe, one of which is the Burst And Transient Source Experiment (BATSE). During the first summer with the BATSE team in 1988, laboratory measurements were completed which test the response of the BATSE modules to gamma-ray sources that are non-axial. The results of these observations are necessary for the correct interpretation of BATSE data obtained after it is put in earth orbit. Subsequent analysis of the data revealed a shift in the centroids of the full-energy photopeaks for angles of incidence between about 70 and 110 degrees. This effect was diagnosed as being due to a radial dependence of the light collecting efficiency of the large-area detector (LAD). Energy-depositing events that occur near the perimeter of the 10-inch radius NaI disc are not as efficiently collected as those events that occur near the disc's center. This radial response is analyzed and in so doing the non-Gaussian shape of the photopeaks seen in the spectra taken at all angles is explained.

  6. National Synchrotron Light Source 2008 Activity Report

    SciTech Connect

    Nasta,K.

    2009-05-01

    Funded by the U.S. Department of Energy's Office of Basic Energy Sciences, the National Synchrotron Light Source (NSLS) is a national user facility that operates two electron storage rings: X-Ray (2.8 GeV, 300 mA) and Vacuum Ultraviolet (VUV) (800 mev, 1.0A). These two rings provide intense light spanning the electromagnetic spectrum -- from very long infrared rays to ultraviolet light and super-short x-rays -- to analyze very small or highly dilute samples. The properties of this light, and the specially designed experimental stations, called beamlines, allow scientists in many diverse disciplines of research to perform experiments not possible at their own laboratories. Each year, about 2,200 scientists from more than 400 universities and companies use the NSLS for research in such diverse fields as biology, physics, chemistry, geology, medicine, and environmental and materials sciences. For example, researchers have used the NSLS to examine the minute details of computer chips, decipher the structures of viruses, probe the density of bone, determine the chemical composition of moon rocks, and reveal countless other mysteries of science. The facility has 65 operating beamlines, with 51 beamlines on the X-Ray Ring and 14 beamlines on the VUV-Infrared Ring. It runs seven days a week, 24 hours a day throughout the year, except during periods of maintenance and studies. Researchers are not charged for beam time, provided that the research results are published in open literature. Proprietary research is conducted on a full-cost-recovery basis. With close to 1,000 publications per year, the NSLS is one of the most prolific scientific facilities in the world. Among the many accolades given to its users and staff, the NSLS has won nine R&D 100 Awards for innovations ranging from a closed orbit feedback system to the first device able to focus a large spread of high-energy x-rays. In addition, a visiting NSLS researcher shared the 2003 Nobel Prize in Chemistry for work

  7. Insertion device operating experience at the Advanced Photon Source

    NASA Astrophysics Data System (ADS)

    Grimmer, John; Ramanathan, Mohan; Smith, Martin; Merritt, Michael

    2002-03-01

    The Advanced Photon Source has 29 insertion devices (IDs) installed in the 7 GeV electron storage ring; 28 of these devices, most of which are 3.3 cm period undulators, use two horizontal permanent magnet structures positioned over a straight vacuum chamber. A support and drive mechanism allows the vertical gap between the magnet structures to be varied, thus changing the x-ray energy produced by the ID [J. Viccaro, Proc. SPIE 1345, 28 (1990); E. Gluskin, J. Synchrotron Radiat. 5, 189 (1998)]. Most of these IDs use a drive scheme with two stepper motors, one driving each end through a mechanism synchronizing the upper and lower magnet structures. Our experience in almost 5 yr of operating this system will be discussed. All of the IDs are in continuous operation for approximately 10 weeks at a time. Reliability of operation is of paramount importance, as access to the storage ring for servicing of a single ID inhibits operation for all users. Our experience in achieving highly reliable ID operation is reviewed. Accuracy of operation and repeatability over time are also vital. To this end, these devices use absolute optical linear encoders with submicron resolution for primary position feedback. Absolute rotary encoders are used as a backup to the linear encoders. The benefits and limitations of each type of encoder, and our experience dealing with radiation and electrical noise are reviewed. The insertion devices operate down to gaps as small as 8.5 mm, with clearance over the vacuum chamber as small as 200 μm. The vacuum chamber has a minimum wall thickness of only 1 mm. A number of levels of safeguards are used to prevent contact between the magnet structure and the vacuum chamber. These safeguards and their evolution after gaining operational experience are presented.

  8. Source-term evaluations from recent core-melt experiments

    SciTech Connect

    Parker, G.W.; Creek, G.E.; Sutton, A.L. Jr.

    1985-01-01

    Predicted consequences of hypothetical severe reactor accidents resulting in core meltdown appear to be too conservatively projected because of the simplistic concepts often assumed for the intricate and highly variable phenomena involved. Recent demonstration work on a modest scale (1-kg) has already revealed significant variations in the mode and temperature for clad failure, in the rates of formation of zirconium alloys, in the nature of the UO/sub 2/-ZrO/sub 2/ eutectic mixtures, and in aerosol generation rates. The current series of core-melt demonstration experiments (at the 10-kg scale) seem to confirm that an increase in size of the meltdown mass will lead to an even further reduction in the amount of vaporized components. Source terms that are based on older release evaluations could be up to an order of magnitude too large. 6 refs., 6 figs., 2 tabs.

  9. Aluminum as a source of background in low background experiments

    NASA Astrophysics Data System (ADS)

    Majorovits, B.; Abt, I.; Laubenstein, M.; Volynets, O.

    2011-08-01

    Neutrinoless double beta decay would be a key to understanding the nature of neutrino masses. The next generation of High Purity Germanium experiments will have to be operated with a background rate of better than 10 -5 counts/(kg y keV) in the region of interest around the Q-value of the decay. Therefore, so far irrelevant sources of background have to be considered. The metalization of the surface of germanium detectors is in general done with aluminum. The background from the decays of 22Na, 26Al, 226Ra and 228Th introduced by this metalization is discussed. It is shown that only a special selection of aluminum can keep these background contributions acceptable.

  10. Advanced Light Source Activity Report 2002

    SciTech Connect

    Duque, Theresa; Greiner, Annette; Moxon, Elizabeth; Robinson, Arthur; Tamura, Lori

    2003-06-12

    This annual report of the Advanced Light Source details science highlights and facility improvements during the year. It also offers information on events sponsored by the facility, technical specifications, and staff and publication information.

  11. First experiments with gasdynamic ion source in CW mode

    SciTech Connect

    Skalyga, V. Vodopyanov, A.; Izotov, I.; Golubev, S.; Tarvainen, O.

    2016-02-15

    A new type of ECR ion source—a gasdynamic ECR ion source—has been recently developed at the Institute of Applied Physics. The main advantages of such device are extremely high ion beam current with a current density up to 600–700 emA/cm{sup 2} in combination with low emittance, i.e., normalized RMS emittance below 0.1 π mm mrad. Previous investigations were carried out in pulsed operation with 37.5 or 75 GHz gyrotron radiation with power up to 100 kW at SMIS 37 experimental facility. The present work demonstrates the first experience of operating the gasdynamic ECR ion source in CW mode. A test bench of SMIS 24 facility has been developed at IAP RAS. 24 GHz radiation of CW gyrotron was used for plasma heating in a magnetic trap with simple mirror configuration. Initial studies of plasma parameters were performed. Ion beams with pulsed and CW high voltage were successfully extracted from the CW discharge. Obtained experimental results demonstrate that all advantages of the gasdynamic source can be realized also in CW operation.

  12. Experiments with rf ovens in ECR ion sources

    SciTech Connect

    Cavenago, M.; Kulevoy, T.; Petrenko, S.

    2004-11-01

    A 34 mm diameter radio frequency (rf) oven system previously developed on bench was inserted and tested into the Electron Cyclotron Resonance (ECR) Ion Source Alice, producing beams from natural copper and silver samples; charge range was typically i=10-13 for copper and i=10-19 for silver, which well compares to previous source yield for xenon (charges 11-20). Some issues of oven design, including wire section effects, and circuit matching, are discussed; taps on the coupling transformer improved the flexibility of rf matching to different crucible materials (tantalum or steel). Details of operating experience (cleaning the oven and replacing sample) are reported; sample duration was more than 100 h and temperature T{sub s} in excess of 1750 K were demonstrated. The ion source operation depends on both the oven distance L{sub oe} from ECR plasma and the bias voltage V{sub b} of the sample. Best conditions were found for close (L{sub oe} congruent with 70 mm) or preferably intermediate positions (L{sub oe} congruent with 106 mm) and for sample negative respect to ECR chamber V{sub b}<-400 V. Final results of current for silver [for example I({sup 107}Ag{sup 17+}) about 1000 nA] are well comparable to xenon case [for example I({sup 129}Xe{sup 18+}) about 500 nA] after correcting for isotopic abundance. Memory effect of metal ion generation was also important and is discussed as well as other time dependent effects and an empirical fit for the aggregate results of silver mass flow. New oven prototypes reached T{sub s} congruent with 2250 K in development tests.

  13. Calorimetric method for determination of 51Cr neutrino source activity

    NASA Astrophysics Data System (ADS)

    Veretenkin, E. P.; Gavrin, V. N.; Danshin, S. N.; Ibragimova, T. V.; Kozlova, Yu. P.; Mirmov, I. N.

    2015-12-01

    Experimental study of nonstandard neutrino properties using high-intensity artificial neutrino sources requires the activity of the sources to be determined with high accuracy. In the BEST project, a calorimetric system for measurement of the activity of high-intensity (a few MCi) neutrino sources based on 51Cr with an accuracy of 0.5-1% is created. In the paper, the main factors affecting the accuracy of determining the neutrino source activity are discussed. The calorimetric system design and the calibration results using a thermal simulator of the source are presented.

  14. National Synchrotron Light Source 2010 Activity Report

    SciTech Connect

    Rowe, M.; Snyder, K. J.

    2010-12-29

    This is a very exciting period for photon sciences at Brookhaven National Laboratory. It is also a time of unprecedented growth for the Photon Sciences Directorate, which operates the National Synchrotron Light Source (NSLS) and is constructing NSLS-II, both funded by the Department of Energy's Office of Science. Reflecting the quick pace of our activities, we chose the theme 'Discovery at Light Speed' for the directorate's 2010 annual report, a fiscal year bookended by October 2009 and September 2010. The year began with the news that NSLS users Venki Ramakrishnan of Cambridge University (also a former employee in Brookhaven's biology department) and Thomas A. Steitz of Yale University were sharing the 2009 Nobel Prize in Chemistry with Ada E. Yonath of the Weizmann Institute of Science. Every research project has the potential for accolades. In 2010, NSLS users and staff published close to 900 papers, with about 170 appearing in premiere journals. Those are impressive stats for a facility nearly three decades old, testament to the highly dedicated team keeping NSLS at peak performance and the high quality of its user community. Our NSLS users come from a worldwide community of scientists using photons, or light, to carry out research in energy and environmental sciences, physics, materials science, chemistry, biology and medicine. All are looking forward to the new capabilities enabled by NSLS-II, which will offer unprecedented resolution at the nanoscale. The new facility will produce x-rays more than 10,000 times brighter than the current NSLS and host a suite of sophisticated instruments for cutting-edge science. Some of the scientific discoveries we anticipate at NSLS-II will lead to major advances in alternative energy technologies, such as hydrogen and solar. These discoveries could pave the way to: (1) catalysts that split water with sunlight for hydrogen production; (2) materials that can reversibly store large quantities of electricity or hydrogen; (3

  15. The Thermal Ion Dynamics Experiment and Plasma Source Instrument

    NASA Technical Reports Server (NTRS)

    Moore, T. E.; Chappell, C. R.; Chandler, M. O.; Fields, S. A.; Pollock, C. J.; Reasoner, D. L.; Young, D. T.; Burch, J. L.; Eaker, N.; Waite, J. H., Jr.; McComas, D. J.; Nordholdt, J. E.; Thomsen, M. F.; Berthelier, J. J.; Robson, R.

    1995-01-01

    The Thermal Ion Dynamics Experiment (TIDE) and the Plasma Source Instrument (PSI) have been developed in response to the requirements of the ISTP Program for three-dimensional (3D) plasma composition measurements capable of tracking the circulation of low-energy (0-500 eV) plasma through the polar magnetosphere. This plasma is composed of penetrating magnetosheath and escaping ionospheric components. It is in part lost to the downstream solar wind and in part recirculated within the magnetosphere, participating in the formation of the diamagnetic hot plasma sheet and ring current plasma populations. Significant obstacles which have previously made this task impossible include the low density and energy of the outflowing ionospheric plasma plume and the positive spacecraft floating potentials which exclude the lowest-energy plasma from detection on ordinary spacecraft. Based on a unique combination of focusing electrostatic ion optics and time of flight detection and mass analysis, TIDE provides the sensitivity (seven apertures of about 1 cm squared effective area each) and angular resolution (6 x 18 degrees) required for this purpose. PSI produces a low energy plasma locally at the POLAR spacecraft that provides the ion current required to balance the photoelectron current, along with a low temperature electron population, regulating the spacecraft potential slightly positive relative to the space plasma. TIDE/PSI will: (a) measure the density and flow fields of the solar and terrestrial plasmas within the high polar cap and magnetospheric lobes; (b) quantify the extent to which ionospheric and solar ions are recirculated within the distant magnetotail neutral sheet or lost to the distant tail and solar wind; (c) investigate the mass-dependent degree energization of these plasmas by measuring their thermodynamic properties; (d) investigate the relative roles of ionosphere and solar wind as sources of plasma to the plasma sheet and ring current.

  16. Structure Modeling and Validation applied to Source Physics Experiments (SPEs)

    NASA Astrophysics Data System (ADS)

    Larmat, C. S.; Rowe, C. A.; Patton, H. J.

    2012-12-01

    The U. S. Department of Energy's Source Physics Experiments (SPEs) comprise a series of small chemical explosions used to develop a better understanding of seismic energy generation and wave propagation for low-yield explosions. In particular, we anticipate improved understanding of the processes through which shear waves are generated by the explosion source. Three tests, 100, 1000 and 1000 kg yields respectively, were detonated in the same emplacement hole and recorded on the same networks of ground motion sensors in the granites of Climax Stock at the Nevada National Security Site. We present results for the analysis and modeling of seismic waveforms recorded close-in on five linear geophone lines extending radially from ground zero, having offsets from 100 to 2000 m and station spacing of 100 m. These records exhibit azimuthal variations of P-wave arrival times, and phase velocity, spreading and attenuation properties of high-frequency Rg waves. We construct a 1D seismic body-wave model starting from a refraction analysis of P-waves and adjusting to address time-domain and frequency-domain dispersion measurements of Rg waves between 2 and 9 Hz. The shallowest part of the structure we address using the arrival times recorded by near-field accelerometers residing within 200 m of the shot hole. We additionally perform a 2D modeling study with the Spectral Element Method (SEM) to investigate which structural features are most responsible for the observed variations, in particular anomalously weak amplitude decay in some directions of this topographically complicated locality. We find that a near-surface, thin, weathered layer of varying thickness and low wave speeds plays a major role on the observed waveforms. We anticipate performing full 3D modeling of the seismic near-field through analysis and validation of waveforms on the 5 radial receiver arrays.

  17. Status of Japanese Experiment Module (JEM) activities

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The current status of the JEM activities are presented in graphic form. The JEM spacecraft configuration is presented. The JEM configuration consist of the Pressurized Module, the Exposed Facility, the Experiment Logistics Module which consist of a pressurized section and an exposed section; and the Remote Manipulator System. The master schedule of the space station is given. Also the development tests of the structure and mechanism, the electrical power system, the data management system, the thermal control system, the environment control system, the experiment support system, and the remote manipulator system are listed.

  18. LDEF active optical system components experiment

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1991-01-01

    A preliminary report on the Active Optical System Components Experiment is presented. This experiment contained 136 components in a six-inch deep tray including lasers, infrared detectors and arrays, ultraviolet light detectors, light-emitting diodes, a light modulator, flash lamps, optical filters, glasses, and samples of surface finishes. The experimental results for those component characteristics appear as much related to the passage of time as to the effects of the space environment, but organic materials and extreme-infrared reflectivity of black paints show unexpected changes.

  19. LDEF active optical system components experiment

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1992-01-01

    A preliminary report on the Active Optical System Components Experiment is presented. This experiment contained 136 components in a six inch deep tray including lasers, infrared detectors and arrays, ultraviolet light detectors, light-emitting diodes, a light modulator, flash lamps, optical filters, glasses, and samples of surface finishes. Thermal, mechanical, and structural considerations leading to the design of the tray hardware are discussed. In general, changes in the retested component characteristics appear as much related to the passage of time as to the effects of the space environment, but organic materials, multilayer optical interference filters, and extreme-infrared reflectivity of black paints show unexpected changes.

  20. Active plasma source formation in the MAP diode

    SciTech Connect

    Lamppa, K.P.; Stinnett, R.W.; Renk, T.J.

    1995-07-01

    The Ion Beam Surface Treatment (IBEST) program is exploring using ion beams to treat the surface of a wide variety of materials. These experiments have shown that improved corrosion resistance, surface hardening, grain size modification, polishing and surface cleaning can all be achieved using a pulsed 0.4-0.8 MeV ion beam delivering 1-10 J/cm{sup 2}. The Magnetically-confined Anode Plasma (MAP) diode, developed at Cornell University, produces an active plasma which can be used to treat the surfaces of materials. The diode consists of a fast puff valve as the source of gas to produce the desired ions and two capacitively driven B-fields. A slow magnetic field is used for electron insulation and a fast field is used to both ionize the puffed gas and to position the plasma in the proper spatial location in the anode prior to the accelerator pulse. The relative timing between subsystems is an important factor in the effective production of the active plasma source for the MAP diode system. The MAP diode has been characterized using a Langmuir probe to measure plasma arrival times at the anode annulus for hydrogen gas. This data was then used to determine the optimum operating point for the MAP diode on RHEPP-1 accelerator shots. Operation of the MAP diode system to produce an ion beam of 500 kV, 12 kA with 40% efficiency (measured at the diode) has been demonstrated.

  1. Active Targets for Experiments with Rare Isotopes

    NASA Astrophysics Data System (ADS)

    Wiedenhoever, Ingo

    2014-09-01

    Experimental studies of un-bound nuclear states and nuclear reaction rates relevant for astrophysical processes are an important area of research with rare isotope beams. Both topics require the development of specialized experimental methods to study resonant reactions. The so-called active target approach, where the target material becomes part of the detection process, promises to combine high yields from thicker targets and low background with high resolution. This presentation will describe the implementation of the active-target technique in the ANASEN detector, which was developed by researchers from Louisiana State University and Florida State University. ANASEN was used in a number of stable and rare iosotope experiments in α- and proton scattering, as well as (α , p) and (d , p) reactions at FSU's in-flight radioactive beam facility RESOLUT. ANASEN also was used to perform the first experiment, proton scattering off a 37K beam at the ReA3 facility. Another active-target detector with a very different approach is found in the Active Target Time-Projection Chamber, which was developed by a collaboration between researchers from MSU, the University of Notre Dame, Western Michigan University, LLNL, LBNL, and St. Mary's University (Canada). First experiments with an AT-TPC prototype have been reported. The talk will summarize the results from the first experiments with these systems, describe further development and future research projects. Experimental studies of un-bound nuclear states and nuclear reaction rates relevant for astrophysical processes are an important area of research with rare isotope beams. Both topics require the development of specialized experimental methods to study resonant reactions. The so-called active target approach, where the target material becomes part of the detection process, promises to combine high yields from thicker targets and low background with high resolution. This presentation will describe the implementation of the

  2. Active Control of Aerodynamic Noise Sources

    NASA Technical Reports Server (NTRS)

    Reynolds, Gregory A.

    2001-01-01

    Aerodynamic noise sources become important when propulsion noise is relatively low, as during aircraft landing. Under these conditions, aerodynamic noise from high-lift systems can be significant. The research program and accomplishments described here are directed toward reduction of this aerodynamic noise. Progress toward this objective include correction of flow quality in the Low Turbulence Water Channel flow facility, development of a test model and traversing mechanism, and improvement of the data acquisition and flow visualization capabilities in the Aero. & Fluid Dynamics Laboratory. These developments are described in this report.

  3. Advanced Light Source: Activity report 1993

    SciTech Connect

    Not Available

    1994-11-01

    The Advanced Light Source (ALS) produces the world`s brightest light in the ultraviolet and soft x-ray regions of the spectrum. The first low-energy third-generation synchrotron source in the world, the ALS provides unprecedented opportunities for research in science and technology not possible anywhere else. This year marked the beginning of operations and the start of the user research program at the ALS, which has already produced numerous high quality results. A national user facility located at Lawrence Berkeley Laboratory of the University of California, the ALS is available to researchers from academia, industry, and government laboratories. This report contains the following: (1) director`s message; (2) operations overview; (3) user program; (4) users` executive committee; (5) industrial outreach; (6) accelerator operations; (7) beamline control system; (8) insertion devices; (9) experimental systems; (10) beamline engineering; (11) first results from user beamlines; (12) beamlines for 1994--1995; (13) special events; (14) publications; (15) advisory panels; and (16) ALS staff.

  4. A 220Rn source for the calibration of low-background experiments

    NASA Astrophysics Data System (ADS)

    Lang, R. F.; Brown, A.; Brown, E.; Cervantes, M.; Macmullin, S.; Masson, D.; Schreiner, J.; Simgen, H.

    2016-04-01

    We characterize two 40 kBq sources of electrodeposited 228Th for use in low-background experiments. The sources efficiently emanate 220Rn, a noble gas that can diffuse in a detector volume. 220Rn and its daughter isotopes produce α-, β-, and γ-radiation, which may used to calibrate a variety of detector responses and features, before decaying completely in only a few days. We perform various tests to place limits on the release of other long-lived isotopes. In particular, we find an emanation of < 0.008 atoms/min/kBq (90% CL) for 228Th and (1.53 ± 0.04) atoms/min/kBq for 224Ra. The sources lend themselves in particular to the calibration of detectors employing liquid noble elements such as argon and xenon. With the source mounted in a noble gas system, we demonstrate that filters are highly efficient in reducing the activity of these longer-lived isotopes further. We thus confirm the suitability of these sources even for use in next-generation experiments, such as XENON1T/XENONnT, LZ, and nEXO.

  5. An experiment to measure the electron neutrino mass using a cryogenic tritium source

    SciTech Connect

    Fackler, O.; Jeziorski, B.; Kolos, W.; Monkhorst, H.; Mugge, M.; Sticker, H.; Szalewicz, K.; White, R.M.; Woerner, R.

    1985-06-25

    An experiment has been performed to determine the electron neutrino mass with the precision of a few eV by measuring the tritium beta decay energy distribution near the endpoint. Key features of the experiment are a 2 eV resolution electrostatic spectrometer and a high-activity frozen tritium source. It is important that the source have electronic wavefunctions which can be accurately calculated. These calculations have been made for tritium and the HeT/sup +/ daughter ion and allow determination of branching fractions to 0.1% and energy of the excited states to 0.1 eV. The excited final molecular state calculations and the experimental apparatus are discussed. 4 refs., 5 figs.

  6. Experiment to measure the electron neutrino mass using a frozen tritium source

    SciTech Connect

    Fackler, O.; Mugge, M.; Sticker, H.; White, R.M.; Woerner, R.

    1985-03-01

    We are performing an experiment to determine the electron neutrino mass with the precision of a few eV by measuring the tritium beta decay energy distribution near the endpoint. Key features of the experiment are a 2 eV resolution electrostatic spectrometer and a high-activity frozen tritium source. It is important that the source have electronic wavefunctions which can be accurately calculated. These calculations can be precisely made for tritium and the HeT/sup +/ daughter ion and allow determination of branching fractions to 0.1% and energy of the excited states to 0.1 eV. We discuss the excited final molecular state calculations and describe the experimental apparatus. 2 references, 6 figures.

  7. The central power source in active galaxies

    NASA Technical Reports Server (NTRS)

    Ptak, Roger; Stoner, Ronald

    1987-01-01

    Potential sources for the central power in AGN are examined. The continuum, emission line profiles, and time variability and broad emission line region for AGN are analyzed. The supermassive black hole hypothesis, the supermassive magnetized core model of Kundt (1978), and the model of Stoner and Ptak (1984) in which the supermassive stars maintain a kind of long-term quasi-stability, but accretion is balanced by mass loss and spherical bursts rather than in jets are considered. It is argued that the hypothesis that the supermassive blackholes are the central engines for AGN is based on theoretical principles; however, AGN emission line profiles and variability suggest a spherical geometry for the observed components of these engines. Also the supermassive black hole models do not account for all the AGN observations.

  8. The Enlightenment Revisited: Sources & Interpretations. Learning Activities.

    ERIC Educational Resources Information Center

    Donato, Clorinda; And Others

    This resource book provides 26 learning activities with background materials for teaching about the Enlightenment. Topics include: (1) "What Was the Enlightenment?"; (2) "An Introduction to the Philosophes"; (3) "Was the Enlightenment a Revolt Against Rationalism?"; (4) "Were the Philosophes Democrats? A…

  9. Preliminary results from the Russian-American gallium experiment Cr-neutrino source measurement

    SciTech Connect

    Elliott, S.R.; Abdurashitov, J.N.; Bowles, T.J.

    1995-12-31

    The Russian-American Gallium Experiment has been collecting solar neutrino data since early 1990. The flux measurement of solar neutrinos is well below that expected from solar models. We discuss the initial results of a measurement of experimental efficiencies by exposing the gallium target to neutrinos from an artificial source. The capture rate of neutrinos from this source is very close to that which is expected. The result can be expressed as a ratio of the measured capture rate to the anticipated rate from the source activity. This ratio is 0.93 + 0.15, {minus}0.17 where the systematic and statistical errors have been combined. To first order the experimental efficiencies are in agreement with those determined during solar neutrino measurements and in previous auxiliary measurements. One must conclude that the discrepancy between the measured solar neutrino flux and that predicted by the solar models can not arise from an experimental artifact. 17 refs., 3 figs., 1 tab.

  10. Monitoring seismic wave speed by an active seismic source

    NASA Astrophysics Data System (ADS)

    Yokoyama, K.; Kawakata, H.; Doi, I.; Okubo, M.; Saiga, A.

    2012-12-01

    Decreases in elastic wave speed around cracked zones prior to faulting in rock fracture experiments have been reported (e.g., Yukutake, 1989; Yoshimitsu et al., 2009). These decreases in wave speed have been considered to be associated with crack and fault growth based on non-destructive observation using X-ray CT scan (Kawakata et al., 1999). Meanwhile, there were some reports on the decreases in seismic wave speed along paths that cross the hypocentral area in periods including some large earthquakes. Uchida et al. (2002) analyzed seismic waveform with explosive sources before and after the 1998 northern Iwate prefecture earthquake, and they showed that the decrease in seismic wave speed approximately 0.1-0.9 % by the earthquake occurrence. Justin et al. (2007) reported the reduction in seismic wave speed accompanied with the 2003 Tokachi oki earthquake around the rupture area by using the four repeating earthquakes that occurred before and after the 2003 Tokachi oki earthquake. However, seismograms of explosive sources or repeating earthquakes are hard to be frequently recorded, which makes the time intervals of estimated seismic wave speed be too long to distinguish preseismic changes from coseismic and post seismic changes. In order to monitor crustal structures and detecting the variation of rock properties in the crust, a kind of active seismic source systems ACROSS (Accurately Controlled Routinely Operated Signal System) has been developed(e.g., Kunitomo and Kumazawa, 2004). We used the controlled seismic source ACROSS, which installed at the Tono mine, Gifu prefecture, central Japan and has been routinely operated by Tono Geoscience center of JAEA (Japan Atomic Energy Agency), automatically. Frequency modulated seismic waves are continuously radiated from approximately 10-20 Hz by eccentric rotation of the source. In order to investigate the stability of ACROSS signals, we used seismograms recorded at the 110m depth of Shobasama observing site, which is

  11. Characterization of the Southern Nevada Region for Source Physics Experiments

    NASA Astrophysics Data System (ADS)

    Pyle, M. L.; Walter, W. R.; Myers, S. C.; Pasyanos, M.; Hauk, T. F.; Ruhl, C. J.; Smith, K. D.

    2013-12-01

    The Source Physics Experiment (SPE) includes an ongoing series of chemical explosions designed to advance seismic monitoring through better understanding of explosion physics and associated simulation codes. A candidate for a future SPE would result in direct comparison of seismic signals from well constrained and co-located earthquake and explosion sources at a common set of receivers. This possibility arises from an area of unusually shallow seismicity in southern Nevada. In May of 1993 a series of events with depths of 1-2 km were recorded at regional seismic stations as well as local stations that were temporarily deployed by the University of Nevada-Reno (UNR). The main shock had a magnitude of approximately 3.7 and 11 more events in the sequence had magnitudes over 2. As part of a feasibility study for a future SPE, LLNL, UNR and NSTec are working to improve our understanding of the region and the propagation of energy from sources in the area to local and regional stations in the western U.S. Six new telemetered seismic stations located at both original 1993 sites and additional sites have been installed and operating in and around the area since early 2011. Using both historic and current data we seek to ensure that we have the best possible locations for the 1993 sequence and current ongoing microseismicity in the region. For this purpose we use the Bayesloc multiple-event location algorithm (Myers et al., 2007; 2009) to improve hypocentral locations. Bayesloc formulates the location problem as a hierarchy of the travel-time model with travel-time corrections, an arrival time model including picking errors, and a prior model for each parameter. Using known locations of nearby previous nuclear tests we have the ability to test the accuracy and robustness of our relocation parameters and results. In our preliminary analysis, we use a mixture of local and regional nuclear test data with the algorithm for the first time, and initial tests show significant

  12. Permafrost Active Layer Seismic Interferometry Experiment (PALSIE).

    SciTech Connect

    Abbott, Robert; Knox, Hunter Anne; James, Stephanie; Lee, Rebekah; Cole, Chris

    2016-01-01

    We present findings from a novel field experiment conducted at Poker Flat Research Range in Fairbanks, Alaska that was designed to monitor changes in active layer thickness in real time. Results are derived primarily from seismic data streaming from seven Nanometric Trillium Posthole seismometers directly buried in the upper section of the permafrost. The data were evaluated using two analysis methods: Horizontal to Vertical Spectral Ratio (HVSR) and ambient noise seismic interferometry. Results from the HVSR conclusively illustrated the method's effectiveness at determining the active layer's thickness with a single station. Investigations with the multi-station method (ambient noise seismic interferometry) are continuing at the University of Florida and have not yet conclusively determined active layer thickness changes. Further work continues with the Bureau of Land Management (BLM) to determine if the ground based measurements can constrain satellite imagery, which provide measurements on a much larger spatial scale.

  13. Sources of Stress, Coping Strategies, Emotional Experience: Effects of the Level of Experience in Primary School Teachers in France

    ERIC Educational Resources Information Center

    Carton, Annie; Fruchart, Eric

    2014-01-01

    This study attempted to determine whether the level of experience affected sources of stress, coping responses and emotional experience in primary school teachers. The first aim was to identify sources of stress and to evaluate coping strategies using the questionnaire of Graziani et al. ("Journal de Thérapie Comportementale et…

  14. New and highly active microbial phosphotriesterase sources.

    PubMed

    Santillan, Julia Y; Dettorre, Lucas A; Lewkowicz, Elizabeth S; Iribarren, Adolfo M

    2016-12-01

    Many toxic insecticides used worldwide as well as some chemical warfare agents are phosphotriester derivatives. Therefore, detoxification of organophosphorus compounds has become the subject of many studies and in particular bioremediation, based on the phosphotriesterase catalysed hydrolysis of these compounds, has shown to be an effective and ecological methodology. In order to identify new bacterial phosphotriesterases, a simple and sensitive fluorimetric screening method on solid media was employed that allowed the selection of six strains with phosphotriesterase activity. Since pH and temperature are important parameters for bioremediation of contaminated soils and waters, the influence of these variables on the rate of the enzymatic hydrolysis was assessed. This study afforded notable results, being the most remarkable one the increased activity exhibited by Nocardia asteroides and Streptomyces setonii strains at 50°C, 7 and 30 times higher than at 30°C, respectively. Compared with the results obtained with Brevundimonas diminuta, whose activity is usually considered as reference, an increase of 26 and 75 times is observed, respectively.

  15. Active commuting to school: an overlooked source of childrens' physical activity?

    PubMed

    Tudor-Locke, C; Ainsworth, B E; Popkin, B M

    2001-01-01

    The assessment and promotion of childrens' healthful physical activity is important: (i) to combat the international obesity epidemic that extends to childhood; and (ii) to establish an early habit of lifestyle physical activity that can be sustained into adolescence and adulthood. The primary focus of both assessment and promotion efforts has been on in-school physical education classes and, to a lesser extent, out-of-school structured exercise, sport and play. A potential source of continuous moderate activity, active commuting to school by means of walking or by bicycle, has been largely ignored in surveys of physical activity. Suggestive evidence of steep declines in the amount of childrens' destination walking can be gleaned from national transportation surveys. At the same time, there has been a dramatic increase in the reported use of motorised vehicles, including the use for chauffeuring children. There is very little evidence to support or refute active commuting to school as an important source of childrens' physical activity; however, this is largely because it has been overlooked in the stampede to assess time in more vigorous activities. The promotion of active commuting to school must be considered in the context of parents' real and perceived concerns for their children's personal and pedestrian safety. We certainly do not have a full understanding at this time of all the factors related to decisions about transportation mode, whether by child, parent, community, or school. Such information is necessary if successful and sustainable interventions can be implemented, important transport policy decisions can be made, and community and school designs can be modified. Practice rarely waits for research, however, and there are numerous examples of innovative programming, policies and environmental designs occurring internationally that can serve as natural experiments for enterprising researchers willing to push the envelope of our understanding of active

  16. Tanshinones: Sources, Pharmacokinetics and Anti-Cancer Activities

    PubMed Central

    Zhang, Yong; Jiang, Peixin; Ye, Min; Kim, Sung-Hoon; Jiang, Cheng; Lü, Junxuan

    2012-01-01

    Tanshinones are a class of abietane diterpene compound isolated from Salvia miltiorrhiza (Danshen or Tanshen in Chinese), a well-known herb in Traditional Chinese Medicine (TCM). Since they were first identified in the 1930s, more than 40 lipophilic tanshinones and structurally related compounds have been isolated from Danshen. In recent decades, numerous studies have been conducted to investigate the isolation, identification, synthesis and pharmacology of tanshinones. In addition to the well-studied cardiovascular activities, tanshinones have been investigated more recently for their anti-cancer activities in vitro and in vivo. In this review, we update the herbal and alternative sources of tanshinones, and the pharmacokinetics of selected tanshinones. We discuss anti-cancer properties and identify critical issues for future research. Whereas previous studies have suggested anti-cancer potential of tanshinones affecting multiple cellular processes and molecular targets in cell culture models, data from in vivo potency assessment experiments in preclinical models vary greatly due to lack of uniformity of solvent vehicles and routes of administration. Chemical modifications and novel formulations had been made to address the poor oral bioavailability of tanshinones. So far, human clinical trials have been far from ideal in their design and execution for the purpose of supporting an anti-cancer indication of tanshinones. PMID:23202971

  17. Middeck Active Control Experiment (MACE), phase A

    NASA Technical Reports Server (NTRS)

    Crawley, Edward F.; Deluis, Javier; Miller, David W.

    1989-01-01

    A rationale to determine which structural experiments are sufficient to verify the design of structures employing Controlled Structures Technology was derived. A survey of proposed NASA missions was undertaken to identify candidate test articles for use in the Middeck Active Control Experiment (MACE). The survey revealed that potential test articles could be classified into one of three roles: development, demonstration, and qualification, depending on the maturity of the technology and the mission the structure must fulfill. A set of criteria was derived that allowed determination of which role a potential test article must fulfill. A review of the capabilities and limitations of the STS middeck was conducted. A reference design for the MACE test article was presented. Computing requirements for running typical closed-loop controllers was determined, and various computer configurations were studied. The various components required to manufacture the structure were identified. A management plan was established for the remainder of the program experiment development, flight and ground systems development, and integration to the carrier. Procedures for configuration control, fiscal control, and safety, reliabilty, and quality assurance were developed.

  18. Large-N Over the Source Physics Experiment (SPE) Phase I and Phase II Test Beds

    NASA Astrophysics Data System (ADS)

    Snelson, C. M.; Carmichael, J. D.; Mellors, R. J.; Abbott, R. E.

    2014-12-01

    One of the current challenges in the field of monitoring and verification is source discrimination of low-yield nuclear explosions from background seismicity, both natural and anthropogenic. Work is underway at the Nevada National Security Site to conduct a series of chemical explosion experiments using a multi-institutional, multi-disciplinary approach. The goal of this series of experiments, called the Source Physics Experiments (SPE), is to refine the understanding of the effect of earth structures on source phenomenology and energy partitioning in the source region, the transition of seismic energy from the near field to the far field, and the development of S waves observed in the far field. To fully explore these problems, the SPE series includes tests in both hard and soft rock geologic environments. The project comprises a number of activities, which range from characterizing the shallow subsurface to acquiring new explosion data from both the near field (<100 m) and the far field (>100 m). SPE includes a series of planned explosions (with different yields and depths of burials), which are conducted in the same hole and monitored by a diverse set of sensors recording characteristics of the explosions, ground-shock, seismo-acoustic energy propagation. This presentation focuses on imaging the full 3D wavefield over hard rock and soft rock test beds using a large number of seismic sensors. This overview presents statistical analyses of optimal sensor layout required to estimate wavefield discriminants and the planned deployment for the upcoming experiments. This work was conducted under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  19. Post-Shot Surface Damage Detected with LIDAR at the Source Physics Experiment Site (Invited)

    NASA Astrophysics Data System (ADS)

    Schultz-Fellenz, E. S.; Sussman, A. J.; Kelley, R. E.; Cooper, D. I.

    2013-12-01

    Designed to improve long-range treaty monitoring capabilities, the Source Physics Experiment series is being conducted at a location in Nevada and provides an opportunity to advance near-field monitoring and field-based investigations of suspected underground test locations. In particular, features associated with underground testing can be evaluated using Source Physics Experiment activities as analogs, linking on-site inspections with remote sensing technologies. Following a calibration shot (SPE 1), SPE 2 (10/2011) and SPE 3 (07/2012) were performed in the same emplacement hole with 1.0 ton of explosives at 150 ft depth. A fourth shot (SPE 4) is planned for August 2013 as a 220 lb (100 kg) TNT equivalent shot at a depth of 315 ft (96 m). Because one of the goals of the Source Physics Experiments is to determine damage effects on seismic wave propagation and improve modeling capabilities, a key component in the predictive component and ultimate validation of the models is a full understanding of the intervening geology between the source and instrumented bore holes. Ground-based LIDAR and fracture mapping, mechanical properties determined via laboratory testing of rock core, discontinuity analysis and optical microscopy of the core rocks were performed prior to and following each experiment. Results of the LIDAR collects from both SPE 2 and 3 indicate a permanent ground displacement of up to several centimeters aligning along the projected surface traces of two faults observed in the core and fractures mapped at the surface. Work by Los Alamos National Laboratory was sponsored by the National Nuclear Security Administration Award No. DE-AC52-06NA25946.

  20. Experiments on Active Cloaking and Illusion for Laplace Equation

    NASA Astrophysics Data System (ADS)

    Ma, Qian; Mei, Zhong Lei; Zhu, Shou Kui; Jin, Tian Yu; Cui, Tie Jun

    2013-10-01

    In recent years, invisibility cloaks have received a lot of attention and interest. These devices are generally classified into two types: passive and active. The design and realization of passive cloaks have been intensively studied using transformation optics and plasmonic approaches. However, active cloaks are still limited to theory and numerical simulations. Here, we present the first experiment on active cloaking and propose an active illusion for the Laplace equation. We make use of a resistor network to simulate a conducting medium. Then, we surround the central region with controlled sources to protect it from outside detection. We show that by dynamically changing the controlled sources, the protected region can be cloaked or disguised as different objects (illusion). Our measurement results agree very well with numerical simulations. Compared with the passive counterparts, the active cloaking and illusion devices do not need complicated metamaterials. They are flexible, in-line controllable, and adaptable to the environment. In addition to dc electricity, the proposed method can also be used for thermodynamics and other problems governed by the Laplace equation.

  1. Angular dependence of source-target-detector in active mode standoff infrared detection

    NASA Astrophysics Data System (ADS)

    Pacheco-Londoño, Leonardo C.; Castro-Suarez, John R.; Aparicio-Bolaños, Joaquín. A.; Hernández-Rivera, Samuel P.

    2013-06-01

    Active mode standoff measurement using infrared spectroscopy were carried out in which the angle between target and the source was varied from 0-70° with respect to the surface normal of substrates containing traces of highly energetic materials (explosives). The experiments were made using three infrared sources: a modulated source (Mod-FTIR), an unmodulated source (UnMod-FTIR) and a scanning quantum cascade laser (QCL), part of a dispersive mid infrared (MIR) spectrometer. The targets consisted of PENT 200 μg/cm2 deposited on aluminum plates placed at 1 m from the sources. The evaluation of the three modalities was aimed at verifying the influence of the highly collimated laser beam in the detection in comparison with the other sources. The Mod-FTIR performed better than QCL source in terms of the MIR signal intensity decrease with increasing angle.

  2. Characterization of an atomic hydrogen source for charge exchange experiments

    NASA Astrophysics Data System (ADS)

    Leutenegger, M. A.; Beiersdorfer, P.; Betancourt-Martinez, G. L.; Brown, G. V.; Hell, N.; Kelley, R. L.; Kilbourne, C. A.; Magee, E. W.; Porter, F. S.

    2016-11-01

    We characterized the dissociation fraction of a thermal dissociation atomic hydrogen source by injecting the mixed atomic and molecular output of the source into an electron beam ion trap containing highly charged ions and recording the x-ray spectrum generated by charge exchange using a high-resolution x-ray calorimeter spectrometer. We exploit the fact that the charge exchange state-selective capture cross sections are very different for atomic and molecular hydrogen incident on the same ions, enabling a clear spectroscopic diagnostic of the neutral species.

  3. The Middeck Active Control Experiment (MACE)

    NASA Technical Reports Server (NTRS)

    Miller, David W.; Sepe, Raymond B.; Rey, Daniel; Saarmaa, Erik; Crawley, Edward F.

    1993-01-01

    The Middeck Active Control Experiment (MACE) is a NASA In-Step and Control Structure Interaction (CSI) Office funded Shuttle middeck experiment. The objective is to investigate the extent to which closed-loop behavior of flexible spacecraft in zero-gravity (0-g) can be predicted. This prediction becomes particularly difficult when dynamic behavior during ground testing exhibits extensive suspension and direct gravity coupling. On-orbit system identification and control reconfiguration is investigated to improve performance which would otherwise be limited due to errors in prediction. The program is presently in its preliminary design phase with launch expected in the summer of 1994. The MACE test article consists of three attitude control torque wheels, a two axis gimballing payload, inertial sensors and a flexible support structure. With the acquisition of a second payload, this will represent a multiple payload platform with significant structural flexibility. This paper presents on-going work in the areas of modelling and control of the MACE test article in the zero and one-gravity environments. Finite element models, which include suspension and gravity effects, and measurement models, derived from experimental data, are used as the basis for Linear Quadratic Gaussian controller designs. Finite element based controllers are analytically used to study the differences in closed-loop performance as the test article transitions between the 0-g and 1-g environments. Measurement based controllers are experimentally applied to the MACE test article in the 1-g environment and achieve over an order of magnitude improvement in payload pointing accuracy when disturbed by a broadband torque disturbance. The various aspects of the flight portion of the experiment are also discussed.

  4. Source Physics Experiment: Research in Support of Verification and Nonproliferation

    DTIC Science & Technology

    2011-09-01

    and predictive capabilities. A number of material test are presented on the granodiorite for both intact and weathered/damaged rock samples. These were... granodiorite for both intact and weathered/damaged rock samples. These were used to improve our material model for the near-source environment. Additionally...and 105 feet depth. Another unexpected curiosity was that U15n intercepted a perched water table at 70 feet which meant the granodiorite was

  5. Performance of the New Los Alamos UCN Source and Implications for Future Experiments

    NASA Astrophysics Data System (ADS)

    Makela, Mark; LANL UCN Team

    2017-01-01

    The Los Alamos Ultracold Neutron (UCN) source was replaced during this past summer and has been commissioned during the last few months. The new source is the result of lessons learned during the 10 year operation of the first UCN source and extensive Monte Carlo analysis. The new source is a spallation driven source based on a solid deuterium UCN moderator similar the previous one. This talk will present an overview of the new source design and the results of commissioning tests. The talk will conclude with a brief overview of the implications of source performance on the neutron lifetime and LANL nEDM experiments. This work was funded by LANL LDRD.

  6. Optical pumping experiments on next-generation light sources

    NASA Astrophysics Data System (ADS)

    Moon, Stephen J.; Fournier, Kevin B.; Scott, H.; Chung, H.-K.; Lee, R. W.

    2004-11-01

    Laser-based plasma spectroscopic techniques have been used with great success to determine the line shapes of atomic transitions in plasmas, study the population kinetics of atomic systems embedded in plasmas, and look at the redistribution of radiation. However, the possibilities for optical lasers end for plasmas with ne > 1022 cm-3 as light propagation is severely altered by the plasma. The construction of the Tesla Test Facility (TTF) at DESY (Deutsche Elektronen-Synchrotron), a short pulse tunable free electron laser in the vacuum-ultraviolet and soft X-ray regime (VUV FEL), based on the SASE (self amplified spontaneous emission) process, will provide a major advance in the capability for dense plasma-related research. This source will provide 1013 photons in a 200 fs duration pulse that is tunable from ~6 nm to 100 nm. Since an VUV FEL will not have the limitation associated with optical lasers the entire field of high density plasmas kinetics in laser produced plasma will then be available to study with the tunable source. Thus, one will be able to use this and other FEL x-ray sources to pump individual transitions creating enhanced population in the excited states that can be easily monitored. We show two case studies illuminating different aspects of plasma spectroscopy.

  7. Optical Pumping Experiments on Next Generation Light Sources

    SciTech Connect

    Moon, S J; Fournier, K B; Scott, H; Chung, H K; Lee, R W

    2004-07-29

    Laser-based plasma spectroscopic techniques have been used with great success to determine the line shapes of atomic transitions in plasmas, study the population kinetics of atomic systems embedded in plasmas, and look at the redistribution of radiation. However, the possibilities for optical lasers end for plasmas with n{sub e}>10{sup 22}cm{sup -3} as light propagation is severely altered by the plasma. The construction of the Tesla Test Facility(TTF) at DESY(Deutsche Elektronen-Synchrotron), a short pulse tunable free electron laser in the vacuum-ultraviolet and soft X-ray regime (VUV FEL), based on the SASE(self amplified spontaneous emission) process, will provide a major advance in the capability for dense plasma-related research. This source will provide 10{sup 13} photons in a 200 fs duration pulse that is tunable from {approx} 6nm to 100nm. Since an VUV FEL will not have the limitation associated with optical lasers the entire field of high density plasmas kinetics in laser produced plasma will then be available to study with tunable source. Thus, one will be able to use this and other FEL x-ray sources to pump individual transitions creating enhanced population in the excited states that can easily be monitored. We show two case studies illuminating different aspects of plasma spectroscopy.

  8. Dynamic Initiator Experiments using IMPULSE (Impact system for Ultrafast Synchrotron Experiments) at the Advanced Photon Source

    NASA Astrophysics Data System (ADS)

    Sanchez, Nathaniel; Jensen, Brian; Ramos, Kyle; Iverson, Adam; Martinez, Michael; Liechty, Gary; Fezzaa, Kamel; Clarke, Steven

    2015-06-01

    We have successfully imaged, for the first time, the operation of copper slapper initiators that are used to initiate high explosive detonators. These data will aid in model development and calibration in order to provide a robust predictive capability and as a design tool in future applications. The initiation system consists of a copper bridge fixed to a parylene flyer. The copper bridge functions when a capacitor is discharged causing current to flow through the narrow bridge. As this happens, a plasma forms due to the high current densities and ohmic heating, which launches the parylene flyer that impacts a high explosive pellet producing detonation. Unlike traditional measurements, x-ray phase contrast imaging can see ``inside'' the process providing unique information with nanosecond time resolution and micrometer spatial resolution. The team performed experiments on the IMPULSE system at the Advanced Photon Source to obtain high resolution, in situ images of this process in real-time. From these images, researchers can examine the formation of the plasma instabilities and their interaction with the flyer, determine the flyer velocity, and obtain crucial information on the spatial distribution of mass and density gradients in the plasma and flyer.

  9. The Sources and Experience of Anxiety in Practice Teaching.

    ERIC Educational Resources Information Center

    Sinclair, Ken; Nicoll, Vivienne

    For most student teachers, practice teaching is a difficult and anxiety-provoking experience. Anxiety arises when feelings of self-adequacy and security are threatened. A survey of 84 teacher education majors shows that anxiety levels are often high immediately prior to the internship; however, the anxiety level gradually declines by the middle of…

  10. Microwave Oven Experiments with Metals and Light Sources

    ERIC Educational Resources Information Center

    Vollmer, Michael; Mollmann, Klaus-Peter; Karstadt, Detlef

    2004-01-01

    "Don't put metal objects in the microwave" is common safety advice. But why? Here we describe demonstration experiments involving placing household metallic objects in a microwave oven. These allow a better understanding of the interaction of microwaves with materials. Light bulbs and discharge lamps can also be used in instructive demonstrations.

  11. Sources of Bias in Performance Evaluation: Two Experiments

    ERIC Educational Resources Information Center

    Feldman, Jack M.; Hilterman, Robert J.

    1977-01-01

    Reports two experiments designed to determine if (1) low-performing blacks would be evaluated lower than comparable whites while high-performing blacks would be rated higher than white counterparts, and (2) perceived social class, not race, would be the relevant variable in the operation of the stereotype confirmation - contrast process. Available…

  12. 1994 Activity Report, National Synchrotron Light Source. Annual report, October 1, 1993-September 30, 1994

    SciTech Connect

    Rothman, E.Z.

    1995-05-01

    This report is a summary of activities carried out at the National Synchrotron Light Source during 1994. It consists of sections which summarize the work carried out in differing scientific disciplines, meetings and workshops, operations experience of the facility, projects undertaken for upgrades, administrative reports, and collections of abstracts and publications generated from work done at the facility.

  13. Modeling active memory: Experiment, theory and simulation

    NASA Astrophysics Data System (ADS)

    Amit, Daniel J.

    2001-06-01

    Neuro-physiological experiments on cognitively performing primates are described to argue that strong evidence exists for localized, non-ergodic (stimulus specific) attractor dynamics in the cortex. The specific phenomena are delay activity distributions-enhanced spike-rate distributions resulting from training, which we associate with working memory. The anatomy of the relevant cortex region and the physiological characteristics of the participating elements (neural cells) are reviewed to provide a substrate for modeling the observed phenomena. Modeling is based on the properties of the integrate-and-fire neural element in presence of an input current of Gaussian distribution. Theory of stochastic processes provides an expression for the spike emission rate as a function of the mean and the variance of the current distribution. Mean-field theory is then based on the assumption that spike emission processes in different neurons in the network are independent, and hence the input current to a neuron is Gaussian. Consequently, the dynamics of the interacting network is reduced to the computation of the mean and the variance of the current received by a cell of a given population in terms of the constitutive parameters of the network and the emission rates of the neurons in the different populations. Within this logic we analyze the stationary states of an unstructured network, corresponding to spontaneous activity, and show that it can be stable only if locally the net input current of a neuron is inhibitory. This is then tested against simulations and it is found that agreement is excellent down to great detail. A confirmation of the independence hypothesis. On top of stable spontaneous activity, keeping all parameters fixed, training is described by (Hebbian) modification of synapses between neurons responsive to a stimulus and other neurons in the module-synapses are potentiated between two excited neurons and depressed between an excited and a quiescent neuron

  14. Advanced photon source experience with vacuum chambers for insertion devices

    SciTech Connect

    Hartog, P.D.; Grimmer, J.; Xu, S.; Trakhtenberg, E.; Wiemerslage, G.

    1997-08-01

    During the last five years, a new approach to the design and fabrication of extruded aluminum vacuum chambers for insertion devices was developed at the Advanced Photon Source (APS). With this approach, three different versions of the vacuum chamber, with vertical apertures of 12 mm, 8 mm, and 5 mm, were manufactured and tested. Twenty chambers were installed into the APS vacuum system. All have operated with beam, and 16 have been coupled with insertion devices. Two different vacuum chambers with vertical apertures of 16 mm and 11 mm were developed for the BESSY-II storage ring and 3 of 16 mm chambers were manufactured.

  15. Pulse-modulated light source for psychometric and vision experiments.

    PubMed

    Scholfield, C N; Murdock, M

    1987-03-01

    Light-emitting diodes (LED) of various colours were used to produce accurately controllable light sources. Variable light intensity was obtained by applying 800-ns current pulses to the LEDs at frequencies 1-1000 kHz using a single potentiometer. These current pulses were generated from an oscillator which was voltage-controlled from a potentiometer and an antilogarithmic amplifier. Its output was gated to produce an optional flicker of 1-100 Hz. The light intensity was indicated by a frequency meter connected to the oscillator. The reading of this was found to linearly indicate light intensity.

  16. Design of a laboratory for experiments with a pulsed neutron source.

    PubMed

    Memoli, G; Trusler, J P M; Ziver, A K

    2009-06-01

    We present the results of a neutron shielding design and optimisation study performed to reduce the exposure to radiological doses arising from a 14 MeV pulsed neutron generator (PNG) having a maximum emission strength of 2.0 x 10(8) neutrons s(-1). The source was intended to be used in a new irradiation facility for the realisation of an experiment on acoustical cavitation in liquids. This paper describes in detail how the facility was designed to reduce both neutron and gamma-ray dose rates to acceptable levels, taking into account the ALARP principle in following the steps of optimisation. In particular, this work compares two different methods of optimisation to assess neutron dose rates: the use of analytical methods and the use of Monte Carlo simulations (MCNPX 2.4). The activation of the surrounding materials during operation was estimated using the neutron spectra as input to the FISPACT 3.0 code. The limitations of a first-order analytical model to determine the neutron activation levels are highlighted. The impact that activation has on the choice of the materials to be used inside the laboratory and on the waiting time before anyone can safely enter the room after the neutron source is switched off is also discussed.

  17. Versatile cold atom source for multi-species experiments

    SciTech Connect

    Paris-Mandoki, A.; Jones, M. D.; Nute, J.; Warriar, S.; Hackermüller, L.; Wu, J.

    2014-11-15

    We present a dual-species oven and Zeeman slower setup capable of producing slow, high-flux atomic beams for loading magneto-optical traps. Our compact and versatile system is based on electronic switching between different magnetic field profiles and is applicable to a wide range of multi-species experiments. We give details of the vacuum setup, coils, and simple electronic circuitry. In addition, we demonstrate the performance of our system by optimized, sequential loading of magneto-optical traps of lithium-6 and cesium-133.

  18. The COHERENT Experiment at the Spallation Neutron Source

    SciTech Connect

    Elliott, Steven Ray

    2015-09-30

    The COHERENT collaboration's primary objective is to measure coherent elastic neutrino- nucleus scattering (CEvNS) using the unique, high-quality source of tens-of-MeV neutrinos provided by the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). In spite of its large cross section, the CEvNS process has never been observed, due to tiny energies of the resulting nuclear recoils which are out of reach for standard neutrino detectors. The measurement of CEvNS has now become feasible, thanks to the development of ultra-sensitive technology for rare decay and weakly-interacting massive particle (dark matter) searches. The CEvNS cross section is cleanly predicted in the standard model; hence its measurement provides a standard model test. It is relevant for supernova physics and supernova-neutrino detection, and enables validation of dark-matter detector background and detector-response models. In the long term, precision measurement of CEvNS will address questions of nuclear structure. COHERENT will deploy multiple detector technologies in a phased approach: a 14-kg CsI[Na] scintillating crystal, 15 kg of p-type point-contact germanium detectors, and 100 kg of liquid xenon in a two-phase time projection chamber. Following an extensive background measurement campaign, a location in the SNS basement has proven to be neutron-quiet and suitable for deployment of the COHERENT detector suite. The simultaneous deployment of the three COHERENT detector subsystems will test the N=2 dependence of the cross section and ensure an unambiguous discovery of CEvNS. This document describes concisely the COHERENT physics motivations, sensitivity and plans for measurements at the SNS to be accomplished on a four-year timescale.

  19. Preface: GRBs and other transient sources: Twenty years of Konus-Wind Experiment

    NASA Astrophysics Data System (ADS)

    Bochkarev, N.

    This special issue of Astronomical and Astrophysical Transactions comprises some of the papers presented at the Ioffe Workshop on Gamma-Ray Bursts and Other Transient Sources: Twenty Years of the Konus-Wind Experiment, which was held at the Ioffe Physico-Technical Institute, St. Petersburg, Russia in September 2014. The issue is dedicated to the memory of Professor Evgenii Pavlovich Mazets (1929-2013) in recognition of his outstanding and significant contribution, as Principal Investigator, of the Russian-American Konus-Wind experiment. The Konus instrument is a gamma-ray burst monitor and it was designed and manufactured at the Ioffe Physico-Technical Institute and was first used in the Venera 11-14 deep space missions in 1978-1983. The next important stage and application of the equipment was in association with the Konus-Wind experiment and the Konus instrument was mounted on board the American spacecraft Wind which was launched in November 1994. Wind's orbit in interplanetary space has proved very effective for the study of flares and other tran-and soft gamma repeaters and also solar sients. The Konus instrument consists of two high sensitivity gamma ray detectors which are positioned and located on the top and bottom of the spacecraft, aligned with the spin axis; the Konus equipment has enabled more than 20 years of constant and uninterrupted surveillance and has produced a very large database pertaining to GRBs. In fact, the Konus-Wind experiment continues to play a significant role in the study of GRBs and is an important source of information and data, as part of the InterPlanetary Network (IPN), together and in synchrony with other active missions/spacecraft (equipped with GRB detectors) including FERMI, SWIFT, AGILE, INTEGRAL.

  20. Advanced Light Source Activity Report 1997/1998

    SciTech Connect

    Greiner, Annette

    1999-03-01

    This Lawrence Berkeley National Laboratory, Advanced Light Source (ALS) activity report for 1997/98 discusses the following topics: Introduction and Overview; Science Highlights; Facility Report; Special Events; ALS Advisory Panels 1997/98; ALS Staff 1997/98 and Facts and Figures for the year.

  1. Memory sources of dreams: the incorporation of autobiographical rather than episodic experiences.

    PubMed

    Malinowski, Josie E; Horton, Caroline L

    2014-08-01

    The present study aimed to explore autobiographical memories (long-lasting memories about the self) and episodic memories (memories about discrete episodes or events) within dream content. We adapted earlier episodic memory study paradigms and reinvestigated the incorporation of episodic memory sources into dreams, operationalizing episodic memory as featuring autonoetic consciousness, which is the feeling of truly re-experiencing or reliving a past event. Participants (n = 32) recorded daily diaries and dream diaries, and reported on wake-dream relations for 2 weeks. Using a new scale, dreams were rated for their episodic richness, which categorized memory sources of dreams as being truly episodic (featuring autonoetic consciousness), autobiographical (containing segregated features of experiences that pertained to waking life) or otherwise. Only one dream (0.5%) was found to contain an episodic memory. However, the majority of dreams (>80%) were found to contain low to moderate incorporations of autobiographical memory features. These findings demonstrate the inactivity of intact episodic memories, and emphasize the activity of autobiographical memory and processing within dreams. Taken together, this suggests that memories for personal experiences are experienced fragmentarily and selectively during dreaming, perhaps in order to assimilate these memories into the autobiographical memory schema.

  2. Inducing in situ, nonlinear soil response applying an active source

    USGS Publications Warehouse

    Johnson, P.A.; Bodin, P.; Gomberg, J.; Pearce, F.; Lawrence, Z.; Menq, F.-Y.

    2009-01-01

    [1] It is well known that soil sites have a profound effect on ground motion during large earthquakes. The complex structure of soil deposits and the highly nonlinear constitutive behavior of soils largely control nonlinear site response at soil sites. Measurements of nonlinear soil response under natural conditions are critical to advancing our understanding of soil behavior during earthquakes. Many factors limit the use of earthquake observations to estimate nonlinear site response such that quantitative characterization of nonlinear behavior relies almost exclusively on laboratory experiments and modeling of wave propagation. Here we introduce a new method for in situ characterization of the nonlinear behavior of a natural soil formation using measurements obtained immediately adjacent to a large vibrator source. To our knowledge, we are the first group to propose and test such an approach. Employing a large, surface vibrator as a source, we measure the nonlinear behavior of the soil by incrementally increasing the source amplitude over a range of frequencies and monitoring changes in the output spectra. We apply a homodyne algorithm for measuring spectral amplitudes, which provides robust signal-to-noise ratios at the frequencies of interest. Spectral ratios are computed between the receivers and the source as well as receiver pairs located in an array adjacent to the source, providing the means to separate source and near-source nonlinearity from pervasive nonlinearity in the soil column. We find clear evidence of nonlinearity in significant decreases in the frequency of peak spectral ratios, corresponding to material softening with amplitude, observed across the array as the source amplitude is increased. The observed peak shifts are consistent with laboratory measurements of soil nonlinearity. Our results provide constraints for future numerical modeling studies of strong ground motion during earthquakes.

  3. Public health genetic counselors: activities, skills, and sources of learning.

    PubMed

    McWalter, Kirsty M; Sdano, Mallory R; Dave, Gaurav; Powell, Karen P; Callanan, Nancy

    2015-06-01

    Specialization within genetic counseling is apparent, with 29 primary specialties listed in the National Society of Genetic Counselors' 2012 Professional Status Survey (PSS). PSS results show a steady proportion of genetic counselors primarily involved in public health, yet do not identify all those performing public health activities. Little is known about the skills needed to perform activities outside of "traditional" genetic counselor roles and the expertise needed to execute those skills. This study aimed to identify genetic counselors engaging in public health activities, the skills used, and the most influential sources of learning for those skills. Participants (N = 155) reported involvement in several public health categories: (a) Education of Public and/or Health Care Providers (n = 80, 52 %), (b) Population-Based Screening Programs (n = 70, 45 %), (c) Lobbying/Public Policy (n = 62, 40 %), (d) Public Health Related Research (n = 47, 30 %), and (e) State Chronic Disease Programs (n = 12, 8 %). Regardless of category, "on the job" was the most common primary source of learning. Genetic counseling training program was the most common secondary source of learning. Results indicate that the number of genetic counselors performing public health activities is likely higher than PSS reports, and that those who may not consider themselves "public health genetic counselors" do participate in public health activities. Genetic counselors learn a diverse skill set in their training programs; some skills are directly applicable to public health genetics, while other public health skills require additional training and/or knowledge.

  4. Source analysis of MEG activities during sleep (abstract)

    NASA Astrophysics Data System (ADS)

    Ueno, S.; Iramina, K.

    1991-04-01

    The present study focuses on magnetic fields of the brain activities during sleep, in particular on K-complexes, vertex waves, and sleep spindles in human subjects. We analyzed these waveforms based on both topographic EEG (electroencephalographic) maps and magnetic fields measurements, called MEGs (magnetoencephalograms). The components of magnetic fields perpendicular to the surface of the head were measured using a dc SQUID magnetometer with a second derivative gradiometer. In our computer simulation, the head is assumed to be a homogeneous spherical volume conductor, with electric sources of brain activity modeled as current dipoles. Comparison of computer simulations with the measured data, particularly the MEG, suggests that the source of K-complexes can be modeled by two current dipoles. A source for the vertex wave is modeled by a single current dipole which orients along the body axis out of the head. By again measuring the simultaneous MEG and EEG signals, it is possible to uniquely determine the orientation of this dipole, particularly when it is tilted slightly off-axis. In sleep stage 2, fast waves of magnetic fields consistently appeared, but EEG spindles appeared intermittently. The results suggest that there exist sources which are undetectable by electrical measurement but are detectable by magnetic-field measurement. Such source can be described by a pair of opposing dipoles of which directions are oppositely oriented.

  5. Numerical simulation of the geographical sources of water for Continental Scale Experiments (CSEs) Precipitation

    NASA Technical Reports Server (NTRS)

    Bosilovich, Michael G.; Sud, Yogesh; Schubert, Siegfried D.; Walker, Gregory K.

    2003-01-01

    There are several important research questions that the Global Energy and Water Cycle Experiment (GEWEX) is actively pursuing, namely: What is the intensity of the water cycle and how does it change? And what is the sustainability of water resources? Much of the research to address these questions is directed at understanding the atmospheric water cycle. In this paper, we have used a new diagnostic tool, called Water Vapor Tracers (WVTs), to quantify the how much precipitation originated as continental or oceanic evaporation. This shows how long water can remain in the atmosphere and how far it can travel. The model-simulated data are analyzed over regions of interest to the GEWEX community, specifically, their Continental Scale Experiments (CSEs) that are in place in the United States, Europe, Asia, Brazil, Africa and Canada. The paper presents quantitative data on how much each continent and ocean on Earth supplies water for each CSE. Furthermore, the analysis also shows the seasonal variation of the water sources. For example, in the United States, summertime precipitation is dominated by continental (land surface) sources of water, while wintertime precipitation is dominated by the Pacific Ocean sources of water. We also analyze the residence time of water in the atmosphere. The new diagnostic shows a longer residence time for water (9.2 days) than more traditional estimates (7.5 days). We emphasize that the results are based on model simulations and they depend on the model s veracity. However, there are many potential uses for the new diagnostic tool in understanding weather processes and large and small scales.

  6. ANS hard X-ray experiment development program. [emission from X-ray sources

    NASA Technical Reports Server (NTRS)

    Parsignault, D.; Gursky, H.; Frank, R.; Kubierschky, K.; Austin, G.; Paganetti, R.; Bawdekar, V.

    1974-01-01

    The hard X-ray (HXX) experiment is one of three experiments included in the Dutch Astronomical Netherlands Satellite, which was launched into orbit on 30 August 1974. The overall objective of the HXX experiment is the detailed study of the emission from known X-ray sources over the energy range 1.5-30keV. The instrument is capable of the following measurements: (1) spectral content over the full energy range with an energy resolution of approximately 20% and time resolution down to 4 seconds; (2) source time variability down to 4 milliseconds; (3) silicon emission lines at 1.86 and 2.00keV; (4) source location to a limit of one arc minute in ecliptic latitude; and (5) spatial structure with angular resolution of the arc minutes. Scientific aspects of experiment, engineering design and implementation of the experiment, and program history are included.

  7. Celebrating the Earth: Stories, Experiences, and Activities.

    ERIC Educational Resources Information Center

    Livo, Norma J.

    Young learners are invited to learn about the natural world through engaging activities that encourage the observation, exploration, and appreciation of nature. Weaving together a stimulating tapestry of folktales, personal narratives, and hands-on activities, this book teaches children about the earth and all of its creatures--birds, plants,…

  8. Talker identification across source mechanisms: Experiments with laryngeal and electrolarynx speech

    PubMed Central

    Perrachione, Tyler K.; Stepp, Cara E.; Hillman, Robert E.; Wong, Patrick C.M.

    2015-01-01

    Purpose To determine listeners' ability to learn talker identity from speech produced with an electrolarynx, explore source and filter differentiation in talker identification, and describe acoustic-phonetic changes associated with electrolarynx use. Method Healthy adult control listeners learned to identify talkers from speech recordings produced using talkers' normal laryngeal vocal source or an electrolarynx. Listeners' abilities to identify talkers from the trained vocal source (Experiment 1) and generalize this knowledge to the untrained source (Experiment 2) were assessed. Acoustic-phonetic measurements of spectral differences between source mechanisms were performed. Additional listeners attempted to match recordings from different source mechanisms to a single talker (Experiment 3). Results Listeners successfully learned talker identity from electrolarynx speech, but less accurately than from laryngeal speech. Listeners were unable to generalize talker identity to the untrained source mechanism. Electrolarynx use resulted in vowels with higher F1 frequencies compared to laryngeal speech. Listeners matched recordings from different sources to a single talker better than chance. Conclusions Electrolarynx speech, though lacking individual differences in voice quality, nevertheless conveys sufficient indexical information related to the vocal filter and articulation for listeners to identify individual talkers. Psychologically, perception of talker identity arises from a “gestalt” of the vocal source and filter. PMID:24801962

  9. Sources of solar wind over the solar activity cycle

    PubMed Central

    Poletto, Giannina

    2012-01-01

    Fast solar wind has been recognized, about 40 years ago, to originate in polar coronal holes (CHs), that, since then, have been identified with sources of recurrent high speed wind streams. As of today, however, there is no general consensus about whether there are, within CHs, preferential locations where the solar wind is accelerated. Knowledge of slow wind sources is far from complete as well. Slow wind observed in situ can be traced back to its solar source by backward extrapolation of magnetic fields whose field lines are streamlines of the outflowing plasma. However, this technique often has not the necessary precision for an indisputable identification of the region where wind originates. As the Sun progresses through its activity cycle, different wind sources prevail and contribute to filling the heliosphere. Our present knowledge of different wind sources is here summarized. Also, a Section addresses the problem of wind acceleration in the low corona, as inferred from an analysis of UV data, and illustrates changes between fast and slow wind profiles and possible signatures of changes along the solar cycle. A brief reference to recent work about the deep roots of solar wind and their changes over different solar cycles concludes the review. PMID:25685421

  10. Sources of solar wind over the solar activity cycle.

    PubMed

    Poletto, Giannina

    2013-05-01

    Fast solar wind has been recognized, about 40 years ago, to originate in polar coronal holes (CHs), that, since then, have been identified with sources of recurrent high speed wind streams. As of today, however, there is no general consensus about whether there are, within CHs, preferential locations where the solar wind is accelerated. Knowledge of slow wind sources is far from complete as well. Slow wind observed in situ can be traced back to its solar source by backward extrapolation of magnetic fields whose field lines are streamlines of the outflowing plasma. However, this technique often has not the necessary precision for an indisputable identification of the region where wind originates. As the Sun progresses through its activity cycle, different wind sources prevail and contribute to filling the heliosphere. Our present knowledge of different wind sources is here summarized. Also, a Section addresses the problem of wind acceleration in the low corona, as inferred from an analysis of UV data, and illustrates changes between fast and slow wind profiles and possible signatures of changes along the solar cycle. A brief reference to recent work about the deep roots of solar wind and their changes over different solar cycles concludes the review.

  11. A computerized system for localizing sources of cardiac activation.

    PubMed

    Salu, Y; Mehrotra, P

    1984-06-01

    A noninvasive method for locating a source of cardiac electrical activity is described. The data acquisition and its preliminary processing is done with the aid of a microcomputer, while lengthier calculations are done on a large computer. The method was tested on 18 patients, and the results indicate that it is reliable, and with further technical refinements it could be used in research and clinical settings.

  12. Obsidian sources characterized by neutron-activation analysis.

    PubMed

    Gordus, A A; Wright, G A; Griffin, J B

    1968-07-26

    Concentrations of elements such as manganese, scandium, lanthanum, rubidium, samarium, barium, and zirconium in obsidian samples from different flows show ranges of 1000 percent or more, whereas the variation in element content in obsidian samples from a single flow appears to be less than 40 percent. Neutron-activation analysis of these elements, as well as of sodium and iron, provides a means of identifying the geologic source of an archeological artifact of obsidian.

  13. The effect of light-activation sources on tooth bleaching

    PubMed Central

    Baroudi, Kusai; Hassan, Nadia Aly

    2014-01-01

    Vital bleaching is one of the most requested cosmetic dental procedures asked by patients who seek a more pleasing smile. This procedure consists of carbamide or hydrogen peroxide gel applications that can be applied in-office or by the patient (at-home/overnight bleaching system). Some in-office treatments utilise whitening light with the objective of speeding up the whitening process. The objective of this article is to review and summarise the current literature with regard to the effect of light-activation sources on in-office tooth bleaching. A literature search was conducted using Medline, accessed via the National Library of Medicine Pub Med from 2003 to 2013 searching for articles relating to effectiveness of light activation sources on in-office tooth bleaching. This study found conflicting evidence on whether light truly improve tooth whitening. Other factors such as, type of stain, initial tooth colour and subject age which can influence tooth bleaching outcome were discussed. Conclusions: The use of light activator sources with in-office bleaching treatment of vital teeth did not increase the efficacy of bleaching or accelerate the bleaching. PMID:25298598

  14. Source altitude for experiments to simulate space-to-earth laser propagation.

    NASA Technical Reports Server (NTRS)

    Minott, P. O.

    1973-01-01

    The bias in scintillation measurements caused by the proximity of a spherical-wave source to the turbulence region of the atmosphere is predicted, and the laser-source altitude required for meaningful experiments simulating space-to-earth laser propagation is estimated. It is concluded that the source should be located at two or more times the maximum altitude of the tropopause to ensure that all measurements are not biased by more than 25%. Thus the vehicle used for experiments of this type should be capable of reaching a minimum altitude of 32 km.

  15. The Effects of Primary Sources and Field Trip Experience on the Knowledge Retention of Multicultural Content

    ERIC Educational Resources Information Center

    Farmer, James; Knapp, Doug; Benton, Gregory M.

    2007-01-01

    Although small in scope, this study attempted to analyze the impacts of primary sources and field trip experiences on multicultural education through first-hand narrative interviews, one year after the experience. In particular, it assessed the recollections of students who participated in a one-half-day field trip to George Washington Carver…

  16. Biochemical assays on plasminogen activators and hormones from kidney sources

    NASA Technical Reports Server (NTRS)

    Barlow, Grant H.; Lewis, Marian L.; Morrison, Dennis R.

    1988-01-01

    Investigations were established for the purpose of analyzing the conditioned media from human embryonic kidney cell subpopulations separated in space by electrophoresis. This data is based on the experiments performed on STS-8 on the continuous flow electrophoresis system. The primary biological activity that was analyzed was plasminogen activator activity, but some assays for erythropoeitin and human granulocyte colony stimulating activity were also performed. It is concluded that a battery of assays are required to completely define the plasminogen activator profile of a conditioned media from cell culture. Each type of assay measures different parts of the mixture and are influenced by different parameters. The functional role of each assay is given along with an indication of which combination of assays are required to answer specific questions. With this type of information it is possible by combinations of assays with mathematical analysis to pinpoint a specific component of the system.

  17. psiTurk: An open-source framework for conducting replicable behavioral experiments online.

    PubMed

    Gureckis, Todd M; Martin, Jay; McDonnell, John; Rich, Alexander S; Markant, Doug; Coenen, Anna; Halpern, David; Hamrick, Jessica B; Chan, Patricia

    2016-09-01

    Online data collection has begun to revolutionize the behavioral sciences. However, conducting carefully controlled behavioral experiments online introduces a number of new of technical and scientific challenges. The project described in this paper, psiTurk, is an open-source platform which helps researchers develop experiment designs which can be conducted over the Internet. The tool primarily interfaces with Amazon's Mechanical Turk, a popular crowd-sourcing labor market. This paper describes the basic architecture of the system and introduces new users to the overall goals. psiTurk aims to reduce the technical hurdles for researchers developing online experiments while improving the transparency and collaborative nature of the behavioral sciences.

  18. Note: A versatile radio-frequency source for cold atom experiments.

    PubMed

    Li, Na; Wu, Yu-Ping; Min, Hao; Yang, Tao; Jiang, Xiao

    2016-08-01

    A radio-frequency (RF) source designed for cold atom experiments is presented. The source uses AD9858, a direct digital synthesizer, to generate the sine wave directly, up to 400 MHz, with sub-Hz resolution. An amplitude control circuit consisting of wideband variable gain amplifier and high speed digital to analog converter is integrated into the source, capable of 70 dB off isolation and 4 ns on-off keying. A field programmable gate array is used to implement a versatile frequency and amplitude co-sweep logic. Owing to modular design, the RF sources have been used on many cold atom experiments to generate various complicated RF sequences, enriching the operation schemes of cold atoms, which cannot be done by standard RF source instruments.

  19. Note: A versatile radio-frequency source for cold atom experiments

    NASA Astrophysics Data System (ADS)

    Li, Na; Wu, Yu-Ping; Min, Hao; Yang, Tao; Jiang, Xiao

    2016-08-01

    A radio-frequency (RF) source designed for cold atom experiments is presented. The source uses AD9858, a direct digital synthesizer, to generate the sine wave directly, up to 400 MHz, with sub-Hz resolution. An amplitude control circuit consisting of wideband variable gain amplifier and high speed digital to analog converter is integrated into the source, capable of 70 dB off isolation and 4 ns on-off keying. A field programmable gate array is used to implement a versatile frequency and amplitude co-sweep logic. Owing to modular design, the RF sources have been used on many cold atom experiments to generate various complicated RF sequences, enriching the operation schemes of cold atoms, which cannot be done by standard RF source instruments.

  20. Pore-space alteration in source rock (shales) during hydrocarbons generation: laboratory experiment

    NASA Astrophysics Data System (ADS)

    Giliazetdinova, D. R.; Korost, D. V.; Nadezhkin, D. V.

    2013-12-01

    Hydrocarbons (HC) are generated from solid organic matter (kerogen) due to thermocatalytic reactions. The rate of such reactions shows direct correlation with temperature and depends on the depth of source rock burial. Burial of sedimentary rock is also inevitably accompanied by its structural alteration owing to compaction, dehydration and re-crystallization. Processes of HC generation, primary migration and structural changes are inaccessible for direct observation in nature, but they can be studied in laboratory experiments. Experiment was carried out with a clayey-carbonate rock sample of the Domanik Horizon taken from boreholes drilled in the northeastern part of the south Tatar arch. The rock chosen fits the very essential requirements - high organic matter content and its low metamorphic grade. Our work aimed at laboratory modeling of HC generation in an undisturbed rock sample by its heating in nitrogen atmosphere based on a specified temperature regime and monitoring alterations in the pore space structure. Observations were carried out with a SkyScan-1172 X-ray microtomography scanner (resulting scan resolution of 1 μm). A cylinder, 44 mm in diameter, was prepared from the rock sample for the pyrolitic and microtomographic analyses. Scanning procedures were carried out in 5 runs. Temperature interval for each run had to match the most important stage of HC generation in the source rock, namely: (1) original structure; (2) 100-300°C - discharge of free and adsorbed HC and water; (3) 300-400°C - initial stage of HC formation owing to high-temperature pyrolysis of the solid organic matter and discharge of the chemically bound water; (4) 400-470°C - temperature interval fitting the most intense stage of HC formation; (5) 470-510°C - final stage of HC formation. Maximum sample heating in the experiment was determined as temperature of the onset of active decomposition of carbonates, i.e., in essence, irreversible metamorphism of the rock. Additional

  1. The effect of alternating influent carbon source composition on activated sludge bioflocculation.

    PubMed

    Van Dierdonck, J; Van den Broeck, R; Vervoort, E; Van Impe, J; Smets, I

    2013-09-10

    The impact of alternating influent carbon sources, i.e., glucose and starch, on activated sludge bioflocculation was investigated. To this end, four lab-scale reactors were operated during a long-term experiment. During this period the influent carbon source ratio (glucose/starch) was alternated every 7 or 35 days (i.e., a fast and slow switching frequency). Bioflocculation was monitored throughout the entire experiment using an extensive set of parameters, including macroscopic and microscopic activated sludge characteristics. Sludge hydrophobicity remained high (>80%) throughout the experiment indicating good bioflocculation. However, sludge settleability decreased for all four reactors after a 60 day adaptation period to the applied alternation in influent carbon source. During this adaptation period, floc size decreased due to the release of microcolonies. The subsequent period was characterized by a decrease in settleability, coinciding with a release of primary particles and an increase in floc size. The observed phenomena could be linked with the protein concentration near the floc surface. This fraction mainly consists of hydrolytic enzymes necessary for the degradation of starch and is responsible for a progressive deterioration of the EPS matrix. The results of this specific study indicate to be independent of the influent carbon source ratio or switching frequency.

  2. Advisory Committee on human radiation experiments. Final report, Supplemental Volume 2. Sources and documentation

    SciTech Connect

    1995-01-01

    This volume and its appendixes supplement the Advisory Committee`s final report by reporting how we went about looking for information concerning human radiation experiments and intentional releases, a description of what we found and where we found it, and a finding aid for the information that we collected. This volume begins with an overview of federal records, including general descriptions of the types of records that have been useful and how the federal government handles these records. This is followed by an agency-by-agency account of the discovery process and descriptions of the records reviewed, together with instructions on how to obtain further information from those agencies. There is also a description of other sources of information that have been important, including institutional records, print resources, and nonprint media and interviews. The third part contains brief accounts of ACHRE`s two major contemporary survey projects (these are described in greater detail in the final report and another supplemental volume) and other research activities. The final section describes how the ACHRE information-nation collections were managed and the records that ACHRE created in the course of its work; this constitutes a general finding aid for the materials deposited with the National Archives. The appendices provide brief references to federal records reviewed, descriptions of the accessions that comprise the ACHRE Research Document Collection, and descriptions of the documents selected for individual treatment. Also included are an account of the documentation available for ACHRE meetings, brief abstracts of the almost 4,000 experiments individually described by ACHRE staff, a full bibliography of secondary sources used, and other information.

  3. A visiting scientist program for the burst and transient source experiment

    NASA Technical Reports Server (NTRS)

    Kerr, Frank J.

    1995-01-01

    During this project, Universities Space Research Association provided program management and the administration for overseeing the performance of the total contractual effort. The program director and administrative staff provided the expertise and experience needed to efficiently manage the program.USRA provided a program coordinator and v visiting scientists to perform scientific research with Burst and Transient Source Experiment (BATSE) data. This research was associated with the primary scientific objectives of BATSE and with the various BATSE collaborations which were formed in response to the Compton Gamma Ray Observatory Guest Investigator Program. USRA provided administration for workshops, colloquia, the preparation of scientific documentation, etc. and also provided flexible program support in order to meet the on-going needs of MSFC's BATSE program. USRA performed tasks associated with the recovery, archiving, and processing of scientific data from BATSE. A bibliography of research in the astrophysics discipline is attached as Appendix 1. Visiting Scientists and Research Associates performed activities on this project, and their technical reports are attached as Appendix 2.

  4. Prevalent flucocorticoid and androgen activity in US water sources

    USGS Publications Warehouse

    Stavreva, Diana A.; George, Anuja A.; Klausmeyer, Paul; Varticovski, Lyuba; Sack, Daniel; Voss, Ty C.; Schiltz, R. Louis; Blazer, Vicki; Iwanowiczl, Luke R.; Hager, Gordon L.

    2012-01-01

    Contamination of the environment with endocrine disrupting chemicals (EDCs) is a major health concern. The presence of estrogenic compounds in water and their deleterious effect are well documented. However, detection and monitoring of other classes of EDCs is limited. Here we utilize a high-throughput live cell assay based on sub-cellular relocalization of GFP-tagged glucocorticoid and androgen receptors (GFP-GR and GFP-AR), in combination with gene transcription analysis, to screen for glucocorticoid and androgen activity in water samples. We report previously unrecognized glucocorticoid activity in 27%, and androgen activity in 35% of tested water sources from 14 states in the US. Steroids of both classes impact body development, metabolism, and interfere with reproductive, endocrine, and immune systems. This prevalent contamination could negatively affect wildlife and human populations.

  5. 5.0. Depletion, activation, and spent fuel source terms

    SciTech Connect

    Wieselquist, William A.

    2016-04-01

    SCALE’s general depletion, activation, and spent fuel source terms analysis capabilities are enabled through a family of modules related to the main ORIGEN depletion/irradiation/decay solver. The nuclide tracking in ORIGEN is based on the principle of explicitly modeling all available nuclides and transitions in the current fundamental nuclear data for decay and neutron-induced transmutation and relies on fundamental cross section and decay data in ENDF/B VII. Cross section data for materials and reaction processes not available in ENDF/B-VII are obtained from the JEFF-3.0/A special purpose European activation library containing 774 materials and 23 reaction channels with 12,617 neutron-induced reactions below 20 MeV. Resonance cross section corrections in the resolved and unresolved range are performed using a continuous-energy treatment by data modules in SCALE. All nuclear decay data, fission product yields, and gamma-ray emission data are developed from ENDF/B-VII.1 evaluations. Decay data include all ground and metastable state nuclides with half-lives greater than 1 millisecond. Using these data sources, ORIGEN currently tracks 174 actinides, 1149 fission products, and 974 activation products. The purpose of this chapter is to describe the stand-alone capabilities and underlying methodology of ORIGEN—as opposed to the integrated depletion capability it provides in all coupled neutron transport/depletion sequences in SCALE, as described in other chapters.

  6. Sms1: Seismic Wave Velocities Variations With Tectonic Stress From Controlled Source Experiment.

    NASA Astrophysics Data System (ADS)

    Chastin, Sebastien; Crampin, Stuart; Shear-Wave Analysis Group

    We present clear observations of seismic velocity variations following comparatively distant seismic activity and a consequently change in tectonic stress. The Stress- Monitoring Site SMSITES at Húsavík in Northern Iceland, described in paper SMS2 at this meeting, was used to monitor short-term variations in absolute seismic velocity. The survey took place between the 10th and 23rd of August 2001. The signal from the controlled source, a DOV (Downhole Orbital Vibrator), was transmitted repeatedly between two boreholes at 315m-offset along a single sub- horizontal direct ray path ray path at ~500m depth. The azimuthal direction between the wells is almost parallel to the strike of the Húsavík-Flatey Transform Fault (HFF) of the Mid-Atlantic Ridge, and is about 200m from the surface break. Source and receivers are in a 200m-thick layer of sandstone sandwiched between fractured layers. The DOV source was swept every 12s and the three-component recordings summed every 100 sweeps. This routine was repeated 24hours a day for 13days. Statistical analysis of the source signal stability indicates the source is coherent at 20µs and that velocity variations can be resolved at close to 1 part in 10-5. Variations in relative velocities of 2% to 5%, are observed peak to peak for Vp, Vsh, and Vsv. The behaviour of P-wave and S-wave velocities is strikingly different and correlates with a swarm of ~110 activity on the 11th of August marks the start of a damped oscillation in S-waves velocities and a sudden 4% decrease of Vp. Following the swarm, Vp increases linearly, whereas Vs follows a typical "S"-shaped relaxation-curve increase to higher (presumably equilibrium) values. This is believed to be the first time that such well

  7. Active and retired public employees' health insurance: potential data sources.

    PubMed

    Morrill, Melinda Sandler

    2014-12-01

    Employer-provided health insurance for public sector workers is a significant public policy issue. Underfunding and the growing costs of benefits may hinder the fiscal solvency of state and local governments. Findings from the private sector may not be applicable because many public sector workers are covered by union contracts or salary schedules and often benefit modifications require changes in legislation. Research has been limited by the difficulty in obtaining sufficiently large and representative data on public sector employees. This article highlights data sources researchers might utilize to investigate topics concerning health insurance for active and retired public sector employees.

  8. Source spectra of the first four Source Physics Experiments (SPE) explosions from the frequency-domain moment-tensor inversion

    SciTech Connect

    Yang, Xiaoning

    2016-08-01

    In this study, I used seismic waveforms recorded within 2 km from the epicenter of the first four Source Physics Experiments (SPE) explosions to invert for the moment-tensor spectra of these explosions. I employed a one-dimensional (1D) Earth model for Green's function calculations. The model was developed from P- and Rg-wave travel times and amplitudes. I selected data for the inversion based on the criterion that they had consistent travel times and amplitude behavior as those predicted by the 1D model. Due to limited azimuthal coverage of the sources and the mostly vertical-component-only nature of the dataset, only long-period, volumetric components of the moment-tensor spectra were well constrained.

  9. Source spectra of the first four Source Physics Experiments (SPE) explosions from the frequency-domain moment-tensor inversion

    DOE PAGES

    Yang, Xiaoning

    2016-08-01

    In this study, I used seismic waveforms recorded within 2 km from the epicenter of the first four Source Physics Experiments (SPE) explosions to invert for the moment-tensor spectra of these explosions. I employed a one-dimensional (1D) Earth model for Green's function calculations. The model was developed from P- and Rg-wave travel times and amplitudes. I selected data for the inversion based on the criterion that they had consistent travel times and amplitude behavior as those predicted by the 1D model. Due to limited azimuthal coverage of the sources and the mostly vertical-component-only nature of the dataset, only long-period, volumetricmore » components of the moment-tensor spectra were well constrained.« less

  10. Efficient localization of synchronous EEG source activities using a modified RAP-MUSIC algorithm.

    PubMed

    Liu, Hesheng; Schimpf, Paul H

    2006-04-01

    Synchronization across different brain regions is suggested to be a possible mechanism for functional integration. Noninvasive analysis of the synchronization among cortical areas is possible if the electrical sources can be estimated by solving the electroencephalography inverse problem. Among various inverse algorithms, spatio-temporal dipole fitting methods such as RAP-MUSIC and R-MUSIC have demonstrated superior ability in the localization of a restricted number of independent sources, and also have the ability to reliably reproduce temporal waveforms. However, these algorithms experience difficulty in reconstructing multiple correlated sources. Accurate reconstruction of correlated brain activities is critical in synchronization analysis. In this study, we modified the well-known inverse algorithm RAP-MUSIC to a multistage process which analyzes the correlation of candidate sources and searches for independent topographies (ITs) among precorrelated groups. Comparative studies were carried out on both simulated data and clinical seizure data. The results demonstrated superior performance with the modified algorithm compared to the original RAP-MUSIC in recovering synchronous sources and localizing the epileptiform activity. The modified RAP-MUSIC algorithm, thus, has potential in neurological applications involving significant synchronous brain activities.

  11. Li{sup +} alumino-silicate ion source development for the neutralized drift compression experiment

    SciTech Connect

    Roy, Prabir K.; Greenway, Wayne G.; Kwan, Joe W.; Seidl, Peter A.; Waldron, William L.; Wu, James K.

    2011-01-15

    We report results on lithium alumino-silicate ion source development in preparation for warm dense matter heating experiments on the new neutralized drift compression experiment II. The practical limit to the current density for a lithium alumino-silicate source is determined by the maximum operating temperature that the ion source can withstand before running into problems of heat transfer, melting of the alumino-silicate material, and emission lifetime. Using small prototype emitters, at a temperature of {approx_equal}1275 deg. C, a space-charge limited Li{sup +} beam current density of J {approx_equal}1 mA/cm{sup 2} was obtained. The lifetime of the ion source was {approx_equal}50 h while pulsing at a rate of 0.033 Hz with a pulse duration of 5-6 {mu}s.

  12. Li+ alumino-silicate ion source development for the Neutralized Drift Compression Experiment (NDCX)

    SciTech Connect

    Roy, Prabir K.; Greenway, Wayne G.; Kwan, Joe W.; Seidl, Peter A.; Waldron, William L.; Wu, James K.

    2010-10-01

    We report results on lithium alumino-silicate ion source development in preparation for warmdense-matter heating experiments on the new Neutralized Drift Compression Experiment (NDCXII). The practical limit to the current density for a lithium alumino-silicate source is determined by the maximum operating temperature that the ion source can withstand before running into problems of heat transfer, melting of the alumino-silicate material, and emission lifetime. Using small prototype emitters, at a temperature of ~;;1275 oC, a space-charge-limited Li+ beam current density of J ~;;1 mA/cm2 was obtained. The lifetime of the ion source was ~;;50 hours while pulsing at a rate of 0.033 Hz with a pulse duration of 5-6 mu s.

  13. Investigation of acoustic gravity waves created by anomalous heat sources: experiments and theoretical analysis

    NASA Astrophysics Data System (ADS)

    Pradipta, R.; Lee, M. C.

    2013-07-01

    We have been investigating high-power radio wave-induced acoustic gravity waves (AGWs) at Gakona, Alaska, using the High-frequency Active Aurora Research Program (HAARP) heating facility (i.e. HF heater) and extensive diagnostic instruments. This work was aimed at performing a controlled study of the space plasma turbulence triggered by the AGWs originating from anomalous heat sources, as observed in our earlier experiments at Arecibo, Puerto Rico (Pradipta 2007 MS Thesis MIT Press, Cambridge, MA). The HF heater operated in continuous wave (CW) O-mode can heat ionospheric plasmas effectively to yield a depleted magnetic flux tube as rising plasma bubbles (Lee et al 1998 Geophys. Res. Lett. 25 579). Two processes are responsible for the depletion of the magnetic flux tube: (i) thermal expansion and (ii) chemical reactions caused by heated ions. The depleted plasmas create large density gradients that can augment spread F processes via generalized Rayleigh-Taylor instabilities (Lee et al 1999 Geophys. Res. Lett. 26 37). It is thus expected that the temperature of neutral particles in the heated ionospheric region can be increased. Such a heat source in the neutral atmosphere may potentially generate AGWs in the form of traveling ionospheric plasma disturbances (TIPDs). We should point out that these TIPDs have features distinctively different from electric and magnetic field (ExB) drifts of HF wave-induced large-scale non-propagating plasma structures. Moreover, it was noted in our recent study of naturally occurring AGW-induced TIDs that only large-scale AGWs can propagate upward to reach higher altitudes. Thus, in our Gakona experiments we select optimum heating schemes for HF wave-induced AGWs that can be distinguished from the naturally occurring ones. The generation and propagation of AGWs are monitored by MUIR (Modular Ultra high-frequency Ionospheric Radar), Digisonde and GPS/low-earth-orbit satellites. Our theoretical and experimental studies have shown that

  14. Quantitation of Lipase Activity from a Bee: An Introductory Enzyme Experiment.

    ERIC Educational Resources Information Center

    Farley, Kathleen A.; Jones, Marjorie A.

    1989-01-01

    This four-hour experiment uses a bee as a source of the enzyme which is reacted with a radioactive substrate to determine the specific activity of the enzyme. Uses thin layer chromatography, visible spectrophotometry, and liquid scintillation spectrometry (if not available a Geiger-Muller counter can be substituted). (MVL)

  15. Verification of Minimum Detectable Activity for Radiological Threat Source Search

    NASA Astrophysics Data System (ADS)

    Gardiner, Hannah; Myjak, Mitchell; Baciak, James; Detwiler, Rebecca; Seifert, Carolyn

    2015-10-01

    The Department of Homeland Security's Domestic Nuclear Detection Office is working to develop advanced technologies that will improve the ability to detect, localize, and identify radiological and nuclear sources from airborne platforms. The Airborne Radiological Enhanced-sensor System (ARES) program is developing advanced data fusion algorithms for analyzing data from a helicopter-mounted radiation detector. This detector platform provides a rapid, wide-area assessment of radiological conditions at ground level. The NSCRAD (Nuisance-rejection Spectral Comparison Ratios for Anomaly Detection) algorithm was developed to distinguish low-count sources of interest from benign naturally occurring radiation and irrelevant nuisance sources. It uses a number of broad, overlapping regions of interest to statistically compare each newly measured spectrum with the current estimate for the background to identify anomalies. We recently developed a method to estimate the minimum detectable activity (MDA) of NSCRAD in real time. We present this method here and report on the MDA verification using both laboratory measurements and simulated injects on measured backgrounds at or near the detection limits. This work is supported by the US Department of Homeland Security, Domestic Nuclear Detection Office, under competitively awarded contract/IAA HSHQDC-12-X-00376. This support does not constitute an express or implied endorsement on the part of the Gov't.

  16. Washer-Gun Plasma Source for Magnetic Reconnection Experiments on VTF

    NASA Astrophysics Data System (ADS)

    Vrublevskis, A.; Egedal, J.; Fox, W.; Katz, N.; Le, A.; Porkolab, M.

    2009-11-01

    We present a recently built electrostatic washer-gun plasma source for the Versatile Toroidal Facility (VTF). The source produces plasmas with estimated densities of ˜10^19 m^- 3 and electron temperatures of ˜5-20 eV. The present plasma source for VTF is microwave-induced electron cyclotron resonant breakdown and requires a strong toroidal magnetic field, which acts as a guide field in reconnection experiments. The gun will allow reconnection experiments with no guide field. The source is based on the design developed by Sterling Scientific [1, 2]. To operate, gas is injected into a channel formed by a stack of alternating molybdenum and boron nitride washers with a molybdenum electrode washer at each end. A capacitor bank is discharged through these electrodes and the gas. The resulting plasma escapes the channel into the main chamber of the experiment. If available, we will present data on argon plasma produced by the gun inside the VTF. [1ex] [1] G. Fiksel, et al., Plasma Sources Sci. Technol., 5, 78 (1996)[0ex] [2] D. Hartog et al., Plasma Sources Sci. Technol., 6, 492 (1997)

  17. Determining minimum alarm activities of orphan sources in scrap loads; Monte Carlo simulations, validated with measurements

    NASA Astrophysics Data System (ADS)

    Takoudis, G.; Xanthos, S.; Clouvas, A.; Potiriadis, C.

    2010-02-01

    Portal monitoring radiation detectors are commonly used by steel industries in the probing and detection of radioactivity contamination in scrap metal. These portal monitors typically consist of polystyrene or polyvinyltoluene (PVT) plastic scintillating detectors, one or more photomultiplier tubes (PMT), an electronic circuit, a controller that handles data output and manipulation linking the system to a display or a computer with appropriate software and usually, a light guide. Such a portal used by the steel industry was opened and all principal materials were simulated using a Monte Carlo simulation tool (MCNP4C2). Various source-detector configurations were simulated and validated by comparison with corresponding measurements. Subsequently an experiment with a uniform cargo along with two sets of experiments with different scrap loads and radioactive sources ( 137Cs, 152Eu) were performed and simulated. Simulated and measured results suggested that the nature of scrap is crucial when simulating scrap load-detector experiments. Using the same simulating configuration, a series of runs were performed in order to estimate minimum alarm activities for 137Cs, 60Co and 192Ir sources for various simulated scrap densities. The minimum alarm activities as well as the positions in which they were recorded are presented and discussed.

  18. Linking Aerosol Source Activities to Present and Future Climate Effects

    NASA Astrophysics Data System (ADS)

    Koch, D.; Bond, T. C.; Streets, D.; Menon, S.; Unger, N.

    2007-05-01

    Aerosol source sectors (transport, power, industry, residential, biomass burning) generate distinct mixtures of aerosol species. These mixtures in turn have different effects on climate. As sectoral emissions change in coming decades, whether by regulation or not, it is helpful to link pollution from source types to climate consequences. We do so, using our global (GISS GCM) aerosol model for present and future IPCC SRES scenarios. According to our model, residential and transport sectors have net positive 1995 aerosol forcings (0.04 and 0.03 W m-2) due to their large black carbon contents. However, the sulfate-dominated power and industry sectors have net negative 1995 forcings (-0.10 and -0.09 W m-2). Due to the near-balance of absorbing and scattering components, biomass burning forcing is small. For the 2050 SRES A1B scenario, the net (negative) aerosol forcing is double 1995 due primarily to increased sulfur emissions in the industry and power sectors. For 2050 B1 the net (negative) forcing decreases relative to 1995, as sulfur emissions are reduced. Both future scenarios project decreasing residential emissions. Yet transport emissions are expected to remain significant and thus become the dominant source of warming aerosols in the future. Aerosol pollution is projected to shift southward relative to the present, as the current industrialized regions generally reduce emissions and tropical and southern hemispheric regions continue to develop. Similar to these SRES scenarios, IIASA scenarios project a decline in residential emissions; however IIASA is more optimistic about transport sector emissions reductions. We will conduct present-day climate experiments, including aerosol direct and indirect effects, to study impacts of power and transport sectors on climate features such as air temperature and hydrologic cycle.

  19. OpenSesame: an open-source, graphical experiment builder for the social sciences.

    PubMed

    Mathôt, Sebastiaan; Schreij, Daniel; Theeuwes, Jan

    2012-06-01

    In the present article, we introduce OpenSesame, a graphical experiment builder for the social sciences. OpenSesame is free, open-source, and cross-platform. It features a comprehensive and intuitive graphical user interface and supports Python scripting for complex tasks. Additional functionality, such as support for eyetrackers, input devices, and video playback, is available through plug-ins. OpenSesame can be used in combination with existing software for creating experiments.

  20. Groundwater seepage landscapes from distant and local sources in experiments and on Mars

    NASA Astrophysics Data System (ADS)

    Marra, W. A.; McLelland, S. J.; Parsons, D. R.; Murphy, B. J.; Hauber, E.; Kleinhans, M. G.

    2015-08-01

    Valleys with theater-shaped heads can form due to the seepage of groundwater and as a result of knickpoint (waterfall) erosion generated by overland flow. This ambiguity in the mechanism of formation hampers the interpretation of such valleys on Mars, particularly since there is limited knowledge of material properties. Moreover, the hydrological implications of a groundwater or surface water origin are important for our understanding of the evolution of surface features on Mars, and a quantification of valley morphologies at the landscape scale may provide diagnostic insights on the formative hydrological conditions. However, flow patterns and the resulting landscapes produced by different sources of groundwater are poorly understood. We aim to improve the understanding of the formation of entire valley landscapes through seepage processes from different groundwater sources that will provide a framework of landscape metrics for the interpretation of such systems. We study groundwater seepage from a distant source of groundwater and from infiltration of local precipitation in a series of sandbox experiments and combine our results with previous experiments and observations of the Martian surface. Key results are that groundwater flow piracy acts on valleys fed by a distant groundwater source and results in a sparsely dissected landscape of many small and a few large valleys. In contrast, valleys fed by a local groundwater source, i.e., nearby infiltration, result in a densely dissected landscape. In addition, valleys fed by a distant groundwater source grow towards that source, while valleys with a local source grow in a broad range of directions and have a strong tendency to bifurcate, particularly on flatter surfaces. We consider these results with respect to two Martian cases: Louros Valles shows properties of seepage by a local source of groundwater and Nirgal Vallis shows evidence of a distant source, which we interpret as groundwater flow from Tharsis.

  1. Measurement of the argon-38(n,2n)argon-37 and calcium- 40(n,alpha)argon-37 cross sections, and National Ignition Facility concrete activation using the rotating target neutron source. The design of an experiment to measure the beryllium-9(n,gamma)beryllium-10 cross section at 14 MeV

    NASA Astrophysics Data System (ADS)

    Belian, Anthony Paul

    The Rotating Target Neutron Source (RTNS) was used in experiments to measure neutron induced cross sections at 14 MeV, and the activation properties of a specific mix of concrete. The RTNS is an accelerator based DT fusion neutron source located at the University of California, Berkeley. Two of the experiments performed for this thesis were specifically of interest for the construction and operation of the National Ignition Facility (NIF), they were the 38Ar(n,2n)37Ar cross section measurement, and the concrete activation measurement. The NIF is a large multi-beam laser facility that will study the effects of age on the nation's stockpile of nuclear weapons. The NIF, when fully operational, will focus the energy of 192 Neodymium glass lasers onto a 1 mm diameter pellet filled with deuterium and tritium fuel. This pellet is compressed by the laser energy giving some of the individual atoms of deuterium and tritium enough kinetic energy to overcome the coulomb barrier and fuse. The energy output from these pellet implosions will be in the range of tens of mega-joules (MJ). The 38Ar(n,2n)37Ar reaction will be useful to NIF scientists to measure important parameters such as target energy yield and areal density. In order to make these measurements precise, an accurate 38Ar(n,2n)37Ar cross section was necessary. The cross sections measured were: 74.9 +/- 3.8 millibarns (mb) at 13.3 +/- 0.01 MeV, 89.2 +/- 4.0 mb at 14.0 +/- 0.03 MeV, and 123.57 +/- 6.4 mb at 15.0 +/- 0.06 MeV. With anticipated energy yields in the tens of mega-joules per pellet implosion, the number of neutrons released is in the range of 1019 to 1020 neutrons per implosion. With such a large number of neutrons, minimizing the activation of the surrounding structure is very much of interest for the sake of personnel radiation safety. To benchmark the computer codes used to calculate the anticipated neutron activation of target bay concrete, samples were irradiated at the RTNS. Dose rates from each sample

  2. Prefrontal cortex activity associated with source monitoring in a working memory task.

    PubMed

    Mitchell, Karen J; Johnson, Marcia K; Raye, Carol L; Greene, Erich J

    2004-01-01

    Using functional magnetic resonance imaging (fMRI), we investigated prefrontal cortex (PFC) activity during remembering specific source information (format, location judgments) versus remembering that could be based on undifferentiated information, such as familiarity (old/new recognition [ON], recency judgments). A working memory (WM) paradigm with an immediate test yielded greater activation in the lateral PFC for format and location source memory (SM) tasks than ON recognition; this SM-related activity was left lateralized. The same regions of PFC were recruited in Experiment 2 when information was tested immediately and after a filled delay. Substituting recency for location judgments (Experiment 3) resulted in an overall shift in task context that produced greater right PFC activity associated with ON and recency tasks compared to the format task, in addition to left SM-related activity. These data extend to WM previous findings from long-term memory (LTM) indicating that the left and right PFC may be differentially involved in memory attributions depending on the specificity of information evaluated. The findings also provide evidence for the continuity of evaluative processes recruited in WM and LTM.

  3. Advancing Explosion Source Theory through Experimentation: Results from Seismic Experiments Since the Moratorium on Nuclear Testing

    NASA Astrophysics Data System (ADS)

    Bonner, J. L.; Stump, B. W.

    2011-12-01

    On 23 September 1992, the United States conducted the nuclear explosion DIVIDER at the Nevada Test Site (NTS). It would become the last US nuclear test when a moratorium ended testing the following month. Many of the theoretical explosion seismic models used today were developed from observations of hundreds of nuclear tests at NTS and around the world. Since the moratorium, researchers have turned to chemical explosions as a possible surrogate for continued nuclear explosion research. This talk reviews experiments since the moratorium that have used chemical explosions to advance explosion source models. The 1993 Non-Proliferation Experiment examined single-point, fully contained chemical-nuclear equivalence by detonating over a kiloton of chemical explosive at NTS in close proximity to previous nuclear explosion tests. When compared with data from these nearby nuclear explosions, the regional and near-source seismic data were found to be essentially identical after accounting for different yield scaling factors for chemical and nuclear explosions. The relationship between contained chemical explosions and large production mining shots was studied at the Black Thunder coal mine in Wyoming in 1995. The research led to an improved source model for delay-fired mining explosions and a better understanding of mining explosion detection by the International Monitoring System (IMS). The effect of depth was examined in a 1997 Kazakhstan Depth of Burial experiment. Researchers used local and regional seismic observations to conclude that the dominant mechanism for enhanced regional shear waves was local Rg scattering. Travel-time calibration for the IMS was the focus of the 1999 Dead Sea Experiment where a 10-ton shot was recorded as far away as 5000 km. The Arizona Source Phenomenology Experiments provided a comparison of fully- and partially-contained chemical shots with mining explosions, thus quantifying the reduction in seismic amplitudes associated with partial

  4. Using Microcomputers in the Physical Chemistry Laboratory: Activation Energy Experiment.

    ERIC Educational Resources Information Center

    Touvelle, Michele; Venugopalan, Mundiyath

    1986-01-01

    Describes a computer program, "Activation Energy," which is designed for use in physical chemistry classes and can be modified for kinetic experiments. Provides suggestions for instruction, sample program listings, and information on the availability of the program package. (ML)

  5. Adolescents' Accounts of Growth Experiences in Youth Activities.

    ERIC Educational Resources Information Center

    Dworkin, Jodi B.; Larson, Reed; Hansen, David

    2003-01-01

    Conducted 10 focus groups in which adolescents discussed their "growth experiences" in extracurricular and community-based activities. The 55 participants reported personal and interpersonal processes and generally described themselves as agents of their own development and change. (SLD)

  6. Crosswell CASSM(Continuous Active-Source Seismic Monitoring): Recent Developments (Invited)

    NASA Astrophysics Data System (ADS)

    Daley, T. M.; Niu, F.; Ajo Franklin, J. B.; Solbau, R.; Silver, P. G.

    2009-12-01

    Continuous active-source monitoring using borehole sources and sensors in a crosswell configuration has proven to be a useful tool for monitoring subsurface processes (Silver, et al, 2007; Daley, et al, 2007; Niu, et al, 2008). This recent work has focused on two applications: monitoring stress changes related to seismicity and monitoring changes in fluid distribution related to geologic storage of CO2. Field tests have demonstrated precision in travel time measurement of up to 1.1 x 10-7 s, and in velocity perturbation measurement of up to 1.1 x 10-5 (Niu, et al 2008). In this talk I will summarize our preceding work and discuss current developments. Current efforts address both hardware and design challenges to improving the methodology. Hardware issues include deployment of multiple piezoelectric sources in shallow and deep boreholes, source and sensor deployment on tubing inside casing, and deployment with other monitoring instrumentation. Design issues are focused on use of multiple sources and/or sensors to obtain optimal spatial resolution for monitoring processes in the interwell region. This design issue can be investigated with optimal experiment design theory. New field experiments for monitoring seismicity (at SAFOD) and CO2 injection (at a US Dept of Energy pilot) are in the design/deployment stage. Current status of these projects will be discussed. References: Silver, P.G., Daley, T.M., Niu, F., Majer, E.L., 2007, Active source monitoring of crosswell seismic travel time for stress induced changes, Bulletin of Seismological Society of America, v97, n1B, p281-293. Daley, T.M., R.D. Solbau, J.B. Ajo-Franklin, S.M. Benson, 2007, Continuous active-source monitoring of CO2 injection in a brine aquifer, Geophysics, v72, n5, pA57-A61, DOI:10.1190/1.2754716. Niu, F., Silver, P.G., Daley, T.M., Cheng, X., Majer, E.L., 2008, Preseismic velocity changes observed from active source monitoring at the Parkfield SAFOD drill site, Nature, 454, 204-208, DOI:10

  7. Educative Experiences of Rural Junior High History Fair Participants Seeking and Evaluating Online Primary Sources

    ERIC Educational Resources Information Center

    Johnson, Riley Todd

    2012-01-01

    This phenomenological ethnographic multi-case study's purpose was to gain insight into experiences of rural junior high History Fair participants as they searched for and evaluated online primary sources. Drawing on the theories of Dewey and Kuhlthau, the study examined how the participants searched the Internet, what strategies they used to…

  8. Practicum Experiences as Sources of Pre-Service Teachers' Self-Efficacy

    ERIC Educational Resources Information Center

    Martins, Maria; Costa, João; Onofre, Marcos

    2015-01-01

    This study examines physical education pre-service teachers' (PTs) self-efficacy and practicum experiences as self-efficacy sources through a mixed-method approach. For the quantitative phase, a self-efficacy questionnaire was applied to 141 PTs. Results showed a stronger self-efficacy in the relationship with students and discipline promotion.…

  9. Report on Active and Planned Spacecraft and Experiments

    NASA Technical Reports Server (NTRS)

    Vostreys, R. W. (Editor); Maitson, H. H. (Editor)

    1981-01-01

    Active and planned spacecraft activity and experiments between June 1, 1980 and May 31, 1981 known to the National Space Science Data Center are described. The information covers a wide range of disciplines: astronomy, Earth sciences, meteorology, planetary sciences, aeronomy, particles and fields, solar physics, life sciences, and material sciences. Each spacecraft and experiment is described and its current status presented. Descriptions of navigational and communications satellites and of spacecraft that contain only continuous radio beacons used for ionospheric studies are specifically excluded.

  10. THE Q/U IMAGING EXPERIMENT: POLARIZATION MEASUREMENTS OF RADIO SOURCES AT 43 AND 95 GHz

    SciTech Connect

    Huffenberger, K. M.; Araujo, D.; Zwart, J. T. L.; Bischoff, C.; Buder, I.; Chinone, Y.; Hasegawa, M.; Cleary, K.; Monsalve, R.; Næss, S. K.; Newburgh, L. B.; Reeves, R.; Ruud, T. M.; Eriksen, H. K.; Wehus, I. K.; Gaier, T.; Dickinson, C.; Gundersen, J. O.; Collaboration: QUIET Collaboration; and others

    2015-06-10

    We present polarization measurements of extragalactic radio sources observed during the cosmic microwave background polarization survey of the Q/U Imaging Experiment (QUIET), operating at 43 GHz (Q-band) and 95 GHz (W-band). We examine sources selected at 20 GHz from the public, >40 mJy catalog of the Australia Telescope (AT20G) survey. There are ∼480 such sources within QUIET’s four low-foreground survey patches, including the nearby radio galaxies Centaurus A and Pictor A. The median error on our polarized flux density measurements is 30–40 mJy per Stokes parameter. At signal-to-noise ratio > 3 significance, we detect linear polarization for seven sources in Q-band and six in W-band; only 1.3 ± 1.1 detections per frequency band are expected by chance. For sources without a detection of polarized emission, we find that half of the sources have polarization amplitudes below 90 mJy (Q-band) and 106 mJy (W-band), at 95% confidence. Finally, we compare our polarization measurements to intensity and polarization measurements of the same sources from the literature. For the four sources with WMAP and Planck intensity measurements >1 Jy, the polarization fractions are above 1% in both QUIET bands. At high significance, we compute polarization fractions as much as 10%–20% for some sources, but the effects of source variability may cut that level in half for contemporaneous comparisons. Our results indicate that simple models—ones that scale a fixed polarization fraction with frequency—are inadequate to model the behavior of these sources and their contributions to polarization maps.

  11. The Q/U Imaging Experiment: Polarization Measurements of Radio Sources at 43 and 95 GHz

    NASA Astrophysics Data System (ADS)

    Huffenberger, K. M.; Araujo, D.; Bischoff, C.; Buder, I.; Chinone, Y.; Cleary, K.; Kusaka, A.; Monsalve, R.; Næss, S. K.; Newburgh, L. B.; Reeves, R.; Ruud, T. M.; Wehus, I. K.; Zwart, J. T. L.; Dickinson, C.; Eriksen, H. K.; Gaier, T.; Gundersen, J. O.; Hasegawa, M.; Hazumi, M.; Miller, A. D.; Radford, S. J. E.; Readhead, A. C. S.; Staggs, S. T.; Tajima, O.; Thompson, K. L.; QUIET Collaboration

    2015-06-01

    We present polarization measurements of extragalactic radio sources observed during the cosmic microwave background polarization survey of the Q/U Imaging Experiment (QUIET), operating at 43 GHz (Q-band) and 95 GHz (W-band). We examine sources selected at 20 GHz from the public, >40 mJy catalog of the Australia Telescope (AT20G) survey. There are ˜480 such sources within QUIET’s four low-foreground survey patches, including the nearby radio galaxies Centaurus A and Pictor A. The median error on our polarized flux density measurements is 30-40 mJy per Stokes parameter. At signal-to-noise ratio > 3 significance, we detect linear polarization for seven sources in Q-band and six in W-band; only 1.3 ± 1.1 detections per frequency band are expected by chance. For sources without a detection of polarized emission, we find that half of the sources have polarization amplitudes below 90 mJy (Q-band) and 106 mJy (W-band), at 95% confidence. Finally, we compare our polarization measurements to intensity and polarization measurements of the same sources from the literature. For the four sources with WMAP and Planck intensity measurements >1 Jy, the polarization fractions are above 1% in both QUIET bands. At high significance, we compute polarization fractions as much as 10%-20% for some sources, but the effects of source variability may cut that level in half for contemporaneous comparisons. Our results indicate that simple models—ones that scale a fixed polarization fraction with frequency—are inadequate to model the behavior of these sources and their contributions to polarization maps.

  12. Calculation of the neutron source distribution in the VENUS PWR Mockup Experiment

    SciTech Connect

    Williams, M.L.; Morakinyo, P.; Kam, F.B.K.; Leenders, L.; Minsart, G.; Fabry, A.

    1984-01-01

    The VENUS PWR Mockup Experiment is an important component of the Nuclear Regulatory Commission's program goal of benchmarking reactor pressure vessel (RPV) fluence calculations in order to determine the accuracy to which RPV fluence can be computed. Of particular concern in this experiment is the accuracy of the source calculation near the core-baffle interface, which is the important region for contributing to RPV fluence. Results indicate that the calculated neutron source distribution within the VENUS core agrees with the experimental measured values with an average error of less than 3%, except at the baffle corner, where the error is about 6%. Better agreement with the measured fission distribution was obtained with a detailed space-dependent cross-section weighting procedure for thermal cross sections near the core-baffle interface region. The maximum error introduced into the predicted RPV fluence due to source errors should be on the order of 5%.

  13. Antiglycation Activity of Iridoids and Their Food Sources.

    PubMed

    West, Brett J; Uwaya, Akemi; Isami, Fumiyuki; Deng, Shixin; Nakajima, Sanae; Jensen, C Jarakae

    2014-01-01

    Iridoids are dietary phytochemicals that may have the ability to inhibit the formation of advanced glycation end products (AGEs). Three studies were conducted to investigate this anti-AGE potential. First, the inhibition of fluorescence intensity by food-derived iridoids, after 4 days of incubation with bovine serum albumin, glucose, and fructose, was used to evaluate in vitro antiglycation activity. Next, an 8-week open-label pilot study used the AGE Reader to measure changes in the skin autofluorescence of 34 overweight adults who consumed daily a beverage containing food sources of iridoids. Finally, a cross-sectional population study with 3913 people analyzed the relationship between daily iridoid intake and AGE accumulation, as measured by skin autofluorescence with the TruAge scanner. In the in vitro test, deacetylasperulosidic acid and loganic acid both inhibited glycation in a concentration-dependent manner, with respective IC50 values of 3.55 and 2.69 mM. In the pilot study, average skin autofluorescence measurements decreased by 0.12 units (P < 0.05). The cross-sectional population survey revealed that, for every mg of iridoids consumed, there is a corresponding decline in AGE associated age of 0.017 years (P < 0.0001). These results suggest that consumption of dietary sources of iridoids may be a useful antiaging strategy.

  14. Source localization of brain activity using helium-free interferometer

    NASA Astrophysics Data System (ADS)

    Dammers, Jürgen; Chocholacs, Harald; Eich, Eberhard; Boers, Frank; Faley, Michael; Dunin-Borkowski, Rafal E.; Jon Shah, N.

    2014-05-01

    To detect extremely small magnetic fields generated by the human brain, currently all commercial magnetoencephalography (MEG) systems are equipped with low-temperature (low-Tc) superconducting quantum interference device (SQUID) sensors that use liquid helium for cooling. The limited and increasingly expensive supply of helium, which has seen dramatic price increases recently, has become a real problem for such systems and the situation shows no signs of abating. MEG research in the long run is now endangered. In this study, we report a MEG source localization utilizing a single, highly sensitive SQUID cooled with liquid nitrogen only. Our findings confirm that localization of neuromagnetic activity is indeed possible using high-Tc SQUIDs. We believe that our findings secure the future of this exquisitely sensitive technique and have major implications for brain research and the developments of cost-effective multi-channel, high-Tc SQUID-based MEG systems.

  15. Source localization of brain activity using helium-free interferometer

    SciTech Connect

    Dammers, Jürgen Chocholacs, Harald; Eich, Eberhard; Boers, Frank; Faley, Michael; Dunin-Borkowski, Rafal E.; Jon Shah, N.

    2014-05-26

    To detect extremely small magnetic fields generated by the human brain, currently all commercial magnetoencephalography (MEG) systems are equipped with low-temperature (low-T{sub c}) superconducting quantum interference device (SQUID) sensors that use liquid helium for cooling. The limited and increasingly expensive supply of helium, which has seen dramatic price increases recently, has become a real problem for such systems and the situation shows no signs of abating. MEG research in the long run is now endangered. In this study, we report a MEG source localization utilizing a single, highly sensitive SQUID cooled with liquid nitrogen only. Our findings confirm that localization of neuromagnetic activity is indeed possible using high-T{sub c} SQUIDs. We believe that our findings secure the future of this exquisitely sensitive technique and have major implications for brain research and the developments of cost-effective multi-channel, high-T{sub c} SQUID-based MEG systems.

  16. Neutron activation analysis detection limits using {sup 252}Cf sources

    SciTech Connect

    DiPrete, D.P.; Sigg, R.A.

    2000-07-01

    The Savannah River Technology Center (SRTC) developed a neutron activation analysis (NAA) facility several decades ago using low-flux {sup 252}Cf neutron sources. Through this time, the facility has addressed areas of applied interest in managing the Savannah River Site (SRS). Some applications are unique because of the site's operating history and its chemical-processing facilities. Because sensitivity needs for many applications are not severe, they can be accomplished using an {approximately}6-mg {sup 252}Cf NAA facility. The SRTC {sup 252}Cf facility continues to support applied research programs at SRTC as well as other SRS programs for environmental and waste management customers. Samples analyzed by NAA include organic compounds, metal alloys, sediments, site process solutions, and many other materials. Numerous radiochemical analyses also rely on the facility for production of short-lived tracers, yielding by activation of carriers and small-scale isotope production for separation methods testing. These applications are more fully reviewed in Ref. 1. Although the flux [{approximately}2 x 10{sup 7} n/cm{sup 2}{center_dot}s] is low relative to reactor facilities, more than 40 elements can be detected at low and sub-part-per-million levels. Detection limits provided by the facility are adequate for many analytical projects. Other multielement analysis methods, particularly inductively coupled plasma atomic emission and inductively coupled plasma mass spectrometry, can now provide sensitivities on dissolved samples that are often better than those available by NAA using low-flux isotopic sources. Because NAA allows analysis of bulk samples, (a) it is a more cost-effective choice when its sensitivity is adequate than methods that require digestion and (b) it eliminates uncertainties that can be introduced by digestion processes.

  17. Simulations towards optimization of a neutron/anti-neutron oscillation experiment at the European Spallation Source

    NASA Astrophysics Data System (ADS)

    Frost, Matthew; Kamyshkov, Yuri; Castellanos, Luis; Klinkby, Esben; US NNbar Collaboration

    2015-04-01

    The observation of Neutron/Anti-neutron oscillation would prove the existence of Baryon Number Violation (BNV), and thus an explanation for the dominance of matter over anti-matter in the universe. The latest experiments have shown the oscillation time to be greater than 8.6 x 107 seconds, whereas current theoretical predictions suggest times on the order of 108 to 109 seconds. A neutron oscillation experiment proposed at the European Spallation Source (ESS) would provide sensitivity of more than 1000 times previous experiments performed, thus providing a result well-suited to confirm or deny current theory. A conceptual design of the proposed experiment will be presented, as well as the optimization of key experiment components using Monte-Carlo simulation methods, including the McStas neutron ray-trace simulation package. This work is supported by the Organized Research Units Program funded by The University of Tennessee, Knoxville Office of Research and Engagement.

  18. Possibility of weather and climate change by active experiments

    NASA Astrophysics Data System (ADS)

    Avakyan, Sergey; Voronin, Nikolai; Troitsky, Arkadil; Chernouss, Sergey

    ). Application of the optical recording channel in active experiments (i.e., at a fixed space-time artificial ionospheric disturbances) allow: - to confirm experimentally the Rydberg channel of generating microwave fluxes from the ionosphere at its perturbations; - to offer remote monitoring as international control of sources of artificial influence on weather and climatic characteristics.

  19. Beam experiments with the Grenoble test electron cyclotron resonance ion source at iThemba LABS

    SciTech Connect

    Thomae, R. Conradie, J.; Fourie, D.; Mira, J.; Nemulodi, F.; Kuechler, D.; Toivanen, V.

    2016-02-15

    At iThemba Laboratory for Accelerator Based Sciences (iThemba LABS) an electron cyclotron ion source was installed and commissioned. This source is a copy of the Grenoble Test Source (GTS) for the production of highly charged ions. The source is similar to the GTS-LHC at CERN and named GTS2. A collaboration between the Accelerators and Beam Physics Group of CERN and the Accelerator and Engineering Department of iThemba LABS was proposed in which the development of high intensity argon and xenon beams is envisaged. In this paper, we present beam experiments with the GTS2 at iThemba LABS, in which the results of continuous wave and afterglow operation of xenon ion beams with oxygen as supporting gases are presented.

  20. An impulsive source with variable output and stable bandwidth for underwater acoustic experiments.

    PubMed

    McNeese, Andrew R; Wilson, Preston S; Sagers, Jason D; Knobles, David P

    2014-07-01

    The Combustive Sound Source (CSS) is being developed as an environmentally friendly source to be used in ocean acoustics research and surveys. It has the ability to maintain the same wide bandwidth signal over a 20 dB drop in source level. The CSS consists of a submersible combustion chamber filled with a fuel/oxidizer mixture. The mixture is ignited and the ensuing combustion and bubble activity radiates an impulsive, thus broadband, acoustic pulse. The ability to control pulse amplitude while maintaining bandwidth is demonstrated.

  1. Experiences with moving to open source standards for building and packaging

    NASA Astrophysics Data System (ADS)

    van Dok, D. H.; Sallé, M.; Koeroo, O. A.

    2014-06-01

    The LCMAPS family of grid security middleware was developed during a series of European grid projects from 2001 until 2013. Since 2009 we actively started to move away from ETICS, the project-specific build system, to common open-source tools for building and packaging, such as the GNU Autotools and the Fedora and Debian tool set. By following the guidelines of these mainstream distributions, and improving the source code to fit in with the commonly available open source tools, we have established low-cost, long term sustainability of the code base.

  2. Studies of HT and HTO Behavior in the Vicinity of Long-Term Emission Source: Model - Experiment Intercomparison

    SciTech Connect

    Golubev, A. V.; Aleinikov, A. Y.; Golubeva, V. N.; Khabibulin, M. M.; Glagolev, M. V.; Misatyuk, S. E.; Mavrin, S. V.; Belot, Y. A.; Raskob, W.; Tate, P. J.

    2003-02-24

    There are presented in the research results of HT and HTO deposition and the model of HT (HTO) atmosphere concentration in the vicinity of a long-term HT and HTO emission source. Scavenging of HTO by precipitations was studied in 6 field experiments. The site of the scavenging experiments was around a 30 m emission source. The sampling arcs were chosen at 150-300 m from the base of the source to minimize dry deposition on the precipitation collectors. Data of the scavenging experiments are presented. Kinetics of HT deposition to soil through its oxidation has been studied in laboratory conditions. The activity of HTO converted in the soil sample during a certain period of time was used to determine the oxidation rate. This rate varies, depending on the catalytic and/or biological activity of the soil material. Theoretical considerations have shown that the deposition rate can be expressed by the effective rate of oxidation, which formally corresponds to the first-order HT oxidation. HT deposition rates are reported. The model, used for assessments, takes into account atmospheric dispersion, deposition and reemission. The model of HTO wet deposition is taken into account kinetics of HTO exchange between vapor and liquid phase with parameters such as rain drop spectra, rain intensity, condensation-evaporation on drop's interface. Gauss type formulae for continuous emission source is used to calculate HTO atmospheric concentration. Meteorological data are used as input parameters for modeling. The data presented on HT deposition to soil and HTO washout by precipitation is required for assessment of consequences of HT (HTO) release into the atmosphere.

  3. Experience API: Flexible, Decentralized and Activity-Centric Data Collection

    ERIC Educational Resources Information Center

    Kevan, Jonathan M.; Ryan, Paul R.

    2016-01-01

    This emerging technology report describes the Experience API (xAPI), a new e-learning specification designed to support the learning community in standardizing and collecting both formal and informal distributed learning activities. Informed by Activity Theory, a framework aligned with constructivism, data is collected in the form of activity…

  4. Long Duration Multi-hohlraum X-ray Sources for Eagle Nebula Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Kane, Jave; Heeter, Robert; Martinez, David; Casner, Alexis; Villette, Bruno; Mancini, Roberto; Pound, Marc

    2013-10-01

    A novel foam-filled multi-hohlraum long-duration x-ray source has been demonstrated at the Omega EP laser and used to obtain L-band spectra of photoionized Ti. A larger scale version of the source will be used in the Science on NIF Eagle Nebula experiments studying dynamic evolution of distinctive pillar and cometary structures in star-forming clouds, where the long duration and directionality of photoionizing radiation from nearby stars generates new classes of flows and instabilities. At NIF, a target representing an astrophysical molecular cloud will be placed several mm from an x-ray source lasting 40-100 ns. At EP, three hohlraums were illuminated in sequence with 3.3 kJ pulses lasting 6 ns, or 4.3 kJ pulses lasting 10 ns, generating 18 or 30 ns of x-ray output at 90-100 eV color temperature. Performance of the source was validated using the μ DMX and VSG spectrometers, ASBO VISAR, and x-ray pinhole imagery. The HYDRA code suggests the EP-scale source can also be shot at NIF with at least 10 kJ per hohlraum. The multi-hohlraum source concept has potential further application to hard x-ray sources, soft x-ray backlighters, and nonlinear ablative hydrodynamics. Prepared by LLNL under Contract DE-AC52-07NA27344. J. Kane supported by DOE OFES grant HEDLP LAB 11-583.

  5. Fruit cuticular waxes as a source of biologically active triterpenoids.

    PubMed

    Szakiel, Anna; Pączkowski, Cezary; Pensec, Flora; Bertsch, Christophe

    2012-06-01

    The health benefits associated with a diet rich in fruit and vegetables include reduction of the risk of chronic diseases such as cardiovascular disease, diabetes and cancer, that are becoming prevalent in the aging human population. Triterpenoids, polycyclic compounds derived from the linear hydrocarbon squalene, are widely distributed in edible and medicinal plants and are an integral part of the human diet. As an important group of phytochemicals that exert numerous biological effects and display various pharmacological activities, triterpenoids are being evaluated for use in new functional foods, drugs, cosmetics and healthcare products. Screening plant material in the search for triterpenoid-rich plant tissues has identified fruit peel and especially fruit cuticular waxes as promising and highly available sources. The chemical composition, abundance and biological activities of triterpenoids occurring in cuticular waxes of some economically important fruits, like apple, grape berry, olive, tomato and others, are described in this review. The need for environmentally valuable and potentially profitable technologies for the recovery, recycling and upgrading of residues from fruit processing is also discussed.

  6. A novel method for the activity measurement of large-area beta reference sources.

    PubMed

    Stanga, D; De Felice, P; Keightley, J; Capogni, M; Ioan, M R

    2016-03-01

    A novel method has been developed for the activity measurement of large-area beta reference sources. It makes use of two emission rate measurements and is based on the weak dependence between the source activity and the activity distribution for a given value of transmission coefficient. The method was checked experimentally by measuring the activity of two ((60)Co and (137)Cs) large-area reference sources constructed from anodized aluminum foils. Measurement results were compared with the activity values measured by gamma spectrometry. For each source, they agree within one standard uncertainty and also agree within the same limits with the certified values of the source activity.

  7. Design of laboratory experiments to study photoionization fronts driven by thermal sources

    SciTech Connect

    Drake, R. P.; Hazak, G.; Keiter, P. A.; Davis, J. S.; Patterson, C. R.; Frank, A.; Blackman, E. G.; Busquet, Michel

    2016-12-20

    This study analyzes the requirements of a photoionization-front experiment that could be driven in the laboratory, using thermal sources to produce the necessary flux of ionizing photons. It reports several associated conclusions. Such experiments will need to employ the largest available facilities, capable of delivering many kJ to MJ of energy to an x-ray source. They will use this source to irradiate a volume of neutral gas, likely of N, on a scale of a few mm to a few cm, increasing with source energy. For a gas pressure of several to ten atmospheres at room temperature, and a source temperature near 100 eV, one will be able to drive a photoionization front through a system of tens to hundreds of photon mean free paths. The front should make the familiar transition from the so-called R-Type to D-Type as the radiation flux diminishes with distance. The N is likely to reach the He-like state. Preheating from the energetic photons appears unlikely to become large enough to alter the essential dynamics of the front beyond some layer near the surface. For well-chosen experimental conditions, competing energy transport mechanisms are small.

  8. Source characterization and modeling development for monoenergetic-proton radiography experiments on OMEGA

    SciTech Connect

    Manuel, M. J.-E.; Zylstra, A. B.; Rinderknecht, H. G.; Casey, D. T.; Rosenberg, M. J.; Sinenian, N.; Li, C. K.; Frenje, J. A.; Seguin, F. H.; Petrasso, R. D.

    2012-06-15

    A monoenergetic proton source has been characterized and a modeling tool developed for proton radiography experiments at the OMEGA [T. R. Boehly et al., Opt. Comm. 133, 495 (1997)] laser facility. Multiple diagnostics were fielded to measure global isotropy levels in proton fluence and images of the proton source itself provided information on local uniformity relevant to proton radiography experiments. Global fluence uniformity was assessed by multiple yield diagnostics and deviations were calculated to be {approx}16% and {approx}26% of the mean for DD and D{sup 3}He fusion protons, respectively. From individual fluence images, it was found that the angular frequencies of Greater-Than-Or-Equivalent-To 50 rad{sup -1} contributed less than a few percent to local nonuniformity levels. A model was constructed using the Geant4 [S. Agostinelli et al., Nuc. Inst. Meth. A 506, 250 (2003)] framework to simulate proton radiography experiments. The simulation implements realistic source parameters and various target geometries. The model was benchmarked with the radiographs of cold-matter targets to within experimental accuracy. To validate the use of this code, the cold-matter approximation for the scattering of fusion protons in plasma is discussed using a typical laser-foil experiment as an example case. It is shown that an analytic cold-matter approximation is accurate to within Less-Than-Or-Equivalent-To 10% of the analytic plasma model in the example scenario.

  9. Source characterization and modeling development for monoenergetic-proton radiography experiments on OMEGA

    NASA Astrophysics Data System (ADS)

    Manuel, M. J.-E.; Zylstra, A. B.; Rinderknecht, H. G.; Casey, D. T.; Rosenberg, M. J.; Sinenian, N.; Li, C. K.; Frenje, J. A.; Séguin, F. H.; Petrasso, R. D.

    2012-06-01

    A monoenergetic proton source has been characterized and a modeling tool developed for proton radiography experiments at the OMEGA [T. R. Boehly et al., Opt. Comm. 133, 495 (1997)], 10.1016/S0030-4018(96)00325-2 laser facility. Multiple diagnostics were fielded to measure global isotropy levels in proton fluence and images of the proton source itself provided information on local uniformity relevant to proton radiography experiments. Global fluence uniformity was assessed by multiple yield diagnostics and deviations were calculated to be ˜16% and ˜26% of the mean for DD and D3He fusion protons, respectively. From individual fluence images, it was found that the angular frequencies of ≳50 rad-1 contributed less than a few percent to local nonuniformity levels. A model was constructed using the Geant4 [S. Agostinelli et al., Nuc. Inst. Meth. A 506, 250 (2003)], 10.1016/S0168-9002(03)01368-8 framework to simulate proton radiography experiments. The simulation implements realistic source parameters and various target geometries. The model was benchmarked with the radiographs of cold-matter targets to within experimental accuracy. To validate the use of this code, the cold-matter approximation for the scattering of fusion protons in plasma is discussed using a typical laser-foil experiment as an example case. It is shown that an analytic cold-matter approximation is accurate to within ≲10% of the analytic plasma model in the example scenario.

  10. Source characterization and modeling development for monoenergetic-proton radiography experiments on OMEGA.

    PubMed

    Manuel, M J-E; Zylstra, A B; Rinderknecht, H G; Casey, D T; Rosenberg, M J; Sinenian, N; Li, C K; Frenje, J A; Séguin, F H; Petrasso, R D

    2012-06-01

    A monoenergetic proton source has been characterized and a modeling tool developed for proton radiography experiments at the OMEGA [T. R. Boehly et al., Opt. Comm. 133, 495 (1997)] laser facility. Multiple diagnostics were fielded to measure global isotropy levels in proton fluence and images of the proton source itself provided information on local uniformity relevant to proton radiography experiments. Global fluence uniformity was assessed by multiple yield diagnostics and deviations were calculated to be ∼16% and ∼26% of the mean for DD and D(3)He fusion protons, respectively. From individual fluence images, it was found that the angular frequencies of ≳50 rad(-1) contributed less than a few percent to local nonuniformity levels. A model was constructed using the Geant4 [S. Agostinelli et al., Nuc. Inst. Meth. A 506, 250 (2003)] framework to simulate proton radiography experiments. The simulation implements realistic source parameters and various target geometries. The model was benchmarked with the radiographs of cold-matter targets to within experimental accuracy. To validate the use of this code, the cold-matter approximation for the scattering of fusion protons in plasma is discussed using a typical laser-foil experiment as an example case. It is shown that an analytic cold-matter approximation is accurate to within ≲10% of the analytic plasma model in the example scenario.

  11. Point source moving above a finite impedance reflecting plane - Experiment and theory

    NASA Technical Reports Server (NTRS)

    Norum, T. D.; Liu, C. H.

    1978-01-01

    A widely used experimental version of the acoustic monopole consists of an acoustic driver of restricted opening forced by a discrete frequency oscillator. To investigate the effects of forward motion on this source, it was mounted above an automobile and driven over an asphalt surface at constant speed past a microphone array. The shapes of the received signal were compared to results computed from an analysis of a fluctuating-mass-type point source moving above a finite impedance reflecting plane. Good agreement was found between experiment and theory when a complex normal impedance representative of a fairly hard acoustic surface was used in the analysis.

  12. Sources and evolution of cloud-active aerosol in California's Sierra Nevada Mountains

    NASA Astrophysics Data System (ADS)

    Roberts, G. C.; Corrigan, C.; Noblitt, S.; Creamean, J.; Collins, D. B.; Cahill, J. F.; Prather, K. A.; Collett, J. L.; Henry, C.

    2011-12-01

    To assess the sources of cloud-active aerosol and their influence on the hydrological cycle in California, the CalWater Experiment took place in winter 2011 in the foothills of the Sierra Nevada Mountains. During this experiment, we coupled the capabilities of demonstrated miniaturized instrumentation - cloud condensation nuclei (CCN), water condensation nuclei (WCN) and microchip capillary electrophoresis (MCE) - to provide direct chemical measurements of cloud active aerosols. Ion concentrations of CCN droplets attribute the anthropogenic, marine and secondary organic contributions to cloud-active aerosols. Detailed spectra from an Aerosol-Time-of-Flight Mass Spectrometer provide additional information on the sources of aerosol. Storm fronts and changes in atmospheric boundary layer brought aerosol and anions associated with Central Valley pollution to the field site with CCN concentrations reaching several thousand cm-3. Hygroscopicity parameters indicate aging of the organic fraction during aerosol transport from the Central Valley to the mountains. Otherwise, CCN concentrations were low when high pressure systems prevented boundary layer development and intrusion of the Central Valley pollution to the site. MCE results show that nitrates and sulfates comprise most of the fraction of the aerosol anion mass (PM1). During the passage of storm fronts, which transported pollution from the Central Valley upslope, nitrate concentrations peaked at several μ g m-3. Low supersaturation CCN concentrations coincide with increases in aerosol nitrate, which suggests that nitrate has a role in cloud formation of giant CCN and, furthermore, in precipitation processes in the Sierra Nevada. CCN spectra show large variations depending on the aerosol sources and sometimes exhibit bi-modal distributions with minima at 0.3% Sc -- similar to the so-called 'Hoppel minima' associated to number size distributions. During these bi-modal events, sulfate also increases supporting the

  13. Design of an intense ion source and LEBT for Jinping Underground Nuclear Astrophysics experiments

    NASA Astrophysics Data System (ADS)

    Wu, Q.; Sun, L. T.; Cui, B. Q.; Lian, G.; Yang, Y.; Ma, H. Y.; Tang, X. D.; Zhang, X. Z.; Zhang, Z. M.; Liu, W. P.

    2016-09-01

    The ongoing Jinping Underground Nuclear Astrophysics experiment (JUNA) will take the advantage of the ultralow background in China Jinping Underground Laboratory (CJPL), high current accelerator driven by on an ECR source and highly sensitive detector to study directly a number of important reactions for the first time within their relevant stellar energy range. A 2.45 GHz ECR ion source is one of its key components to provide 10 emA H+, 10 emA He+ and 2.0 emA He2+ beams for the study of (p,γ), (p,α), (α,p) and (α,γ) reactions in the first phase of the JUNA project. Ion beam is extracted from the source with energies up to 50 kV/q. The following low energy beam transport (LEBT) system transports and matches the ion beam from the exit of ion source to the acceleration tube (AT). The design status of the ECR ion source and LEBT system for the JUNA project are presented. The potential risks of the ion source are also discussed and analysed.

  14. 2001 NSLS ACTIVITY REPORT (NATIONAL SYNCHROTRON LIGHT SOURCE).

    SciTech Connect

    CORWIN, M.A.

    2002-05-01

    The year 2001 has been another highly productive year at the NSLS, with over 2500 users, including 720 first time users, conducting nearly 1200 experiments in fields ranging from the life, materials, chemical, and environmental sciences to applied science and technology. An impressive array of highlights from this scientific activity is included in this Activity Report. They include the first demonstration of a direct structural probe of the superconducting ground state in the cuprates by utilizing anomalous soft x-ray resonance effects to selectively enhance the scattering from doped holes. Another highly significant result was the determination of the structure of the potassium channel membrane protein. This is especially significant as it provides insight into how the channel functions and how it selects a particular kind of ion. In the nanoscience area, small angle x-ray scattering measurements played an essential role in determining that preferential sequestering of tailored metal nanocrystals into a self-assembled lamellar diblock copolymer can produce high quality metallodielectric photonic bandgap structures, demonstrating the potential of these nanocomposites for photonic crystal engineering. The infrared microscopy program continued to yield noteworthy results, including an important study that characterized the types and abundances of organic materials in contaminated and uncontaminated sediments from the New York/New Jersey Harbor. These results will be useful in devising improved methods for the destruction or removal of these environmental contaminants.

  15. Advanced Light Source activity report 1996/97

    SciTech Connect

    1997-09-01

    Ten years ago, the Advanced Light Source (ALS) existed as a set of drawings, calculations, and ideas. Four years ago, it stored an electron beam for the first time. Today, the ALS has moved from those ideas and beginnings to a robust, third-generation synchrotron user facility, with eighteen beam lines in use, many more in planning or construction phases, and hundreds of users from around the world. Progress from concepts to realities is continuous as the scientific program, already strong in many diverse areas, moves in new directions to meet the needs of researchers into the next century. ALS staff members who develop and maintain the infrastructure for this research are similarly unwilling to rest on their laurels. As a result, the quality of the photon beams the authors deliver, as well as the support they provide to users, continues to improve. The ALS Activity Report is designed to share the results of these efforts in an accessible form for a broad audience. The Scientific Program section, while not comprehensive, shares the breadth, variety, and interest of recent research at the ALS. (The Compendium of User Abstracts and Technical Reports provides a more comprehensive and more technical view.) The Facility Report highlights progress in operations, ongoing accelerator research and development, and beamline instrumentation efforts. Although these Activity Report sections are separate, in practice the achievements of staff and users at the ALS are inseparable. User-staff collaboration is essential as they strive to meet the needs of the user community and to continue the ALS's success as a premier research facility.

  16. Background evaluation for the neutron sources in the Daya Bay experiment

    NASA Astrophysics Data System (ADS)

    Gu, W. Q.; Cao, G. F.; Chen, X. H.; Ji, X. P.; Li, G. S.; Ling, J. J.; Liu, J.; Qian, X.; Wang, W.

    2016-10-01

    We present an evaluation of the background induced by 241Am-13C neutron calibration sources in the Daya Bay reactor neutrino experiment. As a significant background for electron-antineutrino detection at 0.26 ± 0.12 per detector per day on average, it has been estimated by a Monte Carlo simulation that was benchmarked by a special calibration data set. This dedicated data set also provides the energy spectrum of the background.

  17. Background evaluation for the neutron sources in the Daya Bay experiment

    DOE PAGES

    Gu, W. Q.; Cao, G. F.; Chen, X. H.; ...

    2016-07-06

    Here, we present an evaluation of the background induced by 241Am–13C neutron calibration sources in the Daya Bay reactor neutrino experiment. Furthermore, as a significant background for electron-antineutrino detection at 0.26 ± 0.12 detector per day on average, it has been estimated by a Monte Carlo simulation that was benchmarked by a special calibration data set. This dedicated data set also provides the energy spectrum of the background.

  18. Array Receivers and Sound Sources for Three Dimensional Shallow Water Acoustic Field Experiments

    DTIC Science & Technology

    2016-12-06

    Water Acoustic Field Experiments NOOO 14-15-1-2893 Sc. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Sd. PROJECT NUMBER Ying Tsong-Lin 132893SP Se. TASK...testing. 1S. SUBJECT TERMS acoustics, shallow water , Arctic Ocean , 3-D acoustic propagation, shelfbreak 16. SECURITY CLASSIFICATION OF: R b...Approved f or public release; distribution is unlimited. Array Receivers and Sound Sources for Three-Dimensional Shallow- Water Acoustic Field

  19. Field and synthetic experiments for virtual source crosswell tomography in vertical wells: Perth Basin, Western Australia

    NASA Astrophysics Data System (ADS)

    Almalki, Majed; Harris, Brett; Dupuis, J. Christian

    2013-11-01

    It is common for at least one monitoring well to be located proximally to a production well. This presents the possibility of applying crosswell technologies to resolve a range of earth properties between the wells. We present both field and synthetic examples of dual well walk-away vertical seismic profiling in vertical wells and show how the direct arrivals from a virtual source may be used to create velocity images between the wells. The synthetic experiments highlight the potential of virtual source crosswell tomography where large numbers of closely spaced receivers can be deployed in multiple wells. The field experiment is completed in two monitoring wells at an aquifer storage and recovery site near Perth, Western Australia. For this site, the crosswell velocity distribution recovered from inversion of travel times between in-hole virtual sources and receivers is highly consistent with what is expected from sonic logging and detailed zero-offset vertical seismic profiling. When compared to conventional walkaway vertical seismic profiling, the only additional effort required to complete dual-well walkaway vertical seismic profiling is the deployment of seismic sensors in the second well. The significant advantage of virtual source crosswell tomography is realised where strong near surface heterogeneity results in large travel time statics.

  20. Design of laboratory experiments to study photoionization fronts driven by thermal sources

    DOE PAGES

    Drake, R. P.; Hazak, G.; Keiter, P. A.; ...

    2016-12-20

    This study analyzes the requirements of a photoionization-front experiment that could be driven in the laboratory, using thermal sources to produce the necessary flux of ionizing photons. It reports several associated conclusions. Such experiments will need to employ the largest available facilities, capable of delivering many kJ to MJ of energy to an x-ray source. They will use this source to irradiate a volume of neutral gas, likely of N, on a scale of a few mm to a few cm, increasing with source energy. For a gas pressure of several to ten atmospheres at room temperature, and a sourcemore » temperature near 100 eV, one will be able to drive a photoionization front through a system of tens to hundreds of photon mean free paths. The front should make the familiar transition from the so-called R-Type to D-Type as the radiation flux diminishes with distance. The N is likely to reach the He-like state. Preheating from the energetic photons appears unlikely to become large enough to alter the essential dynamics of the front beyond some layer near the surface. For well-chosen experimental conditions, competing energy transport mechanisms are small.« less

  1. Operational experience of SST1 NBI control system with prototype Ion source

    NASA Astrophysics Data System (ADS)

    Patel, V. B.; Patel, P. J.; Singh, N. P.; Patel, G. B.; Onali, Raja; Tripathi, V.; Thakkar, D.; Gupta, L. N.; Prahlad, V.; Sharma, S. K.; Bandyopadyay, M.; Chakraborty, A. K.; Baruah, U. K.; Mattoo, S. K.; Nbi Team

    2010-02-01

    This paper presents operational experience of integrated control of the arc-filament and High-voltage power supply of Steady State Tokamak (SST)-1 NBI system using Versa Module Europa (VME) system on prototype Ion source. The control algorithm is implemented on the VxWorks operating system using 'C' language. This paper also describes the operating sequence and controls on power supply system. Discharge and Filament power supplies are controlled in such a way so that necessary discharge current can be available in Ion Source. The discharge current is controlled by manipulating the filament current. Close loop control is implemented on each filament power supply with feedback from Discharge Current to control the overall discharge inside the ion source. Necessary actions for shut OFF and subsequent Turn ON are also taken during breakdowns between the Grids of the ion source. Total numbers of breakdowns are also monitored. Shot is terminated, if the breakdown count is higher than the set value. This control system can be programmed to restart High-voltage power supply within 5mS after breakdown occurs. This control system is capable to handle the all types of dynamics in the system. This paper also presents results of experiment.

  2. Groundwater seepage landscapes from local or distal sources in experiments and on Mars

    NASA Astrophysics Data System (ADS)

    Marra, W. A.; McLelland, S. J.; Parsons, D. R.; Murphy, B. J.; Hauber, E.; Kleinhans, M. G.

    2015-02-01

    Theater-headed valleys can form due to groundwater sapping, but these valleys could also be the result of knick-point (waterfall) erosion generated by overland flow. This morphological ambiguity hampers the interpretation of such valleys on Mars, especially due to insufficient knowledge of material properties, but the climate implications are quite different. Instead of single-valley morphology, metrics of the entire landscape may provide diagnostic insight in the formative hydrological conditions. However, flow patterns and the resulting landscapes are different for different sources of groundwater and poorly understood. We aim to increase our understanding of the formation of the entire landscapes by sapping from different sources of groundwater and to provide a framework of landscape metrics of such systems to aid interpretation of such landscapes. We study sapping from local and distal sources of groundwater in sandbox experiments and combine our results with previous experiments. Key results are that groundwater piracy acts on distally-fed valleys, which results in a sparsely dissected landscape of many small and a few large valleys while locally-fed valleys result in a densely dissected landscape. In addition, distally-fed valleys grow into the direction of the groundwater source while locally-fed channels grow in a broad range of directions and have a strong tendency to bifurcate, particularly on flat horizontal surfaces. As an example, we apply these results to two Martian cases. The valleys of Louros Valles show properties of sapping by a local source and Nirgal Vallis shows evidence of a distal source, which is likely groundwater from Tharsis.

  3. Energy Spectra of Abundant Cosmic-ray Nuclei in Sources, According to the ATIC Experiment

    NASA Astrophysics Data System (ADS)

    Panov, A. D.; Sokolskaya, N. V.; Zatsepin, V. I.

    2017-03-01

    One of the main results of the ATIC (Advanced Thin Ionization Calorimeter) experiment is a collection of energy spectra of abundant cosmic-ray nuclei: protons, He, C, O, Ne, Mg, Si, and Fe measured in terms of energy per particle in the energy range from 50 GeV to tens of teraelectronvolts. In this paper, the ATIC energy spectra of abundant primary nuclei are back-propagated to the spectra in sources in terms of magnetic rigidity using a leaky-box approximation of three different GALPROP-based diffusion models of propagation that fit the latest B/C data of the AMS-02 experiment. It is shown that the results of a comparison of the slopes of the spectra in sources are weakly model dependent; therefore the differences of spectral indices are reliable data. A regular growth of the steepness of spectra in sources in the range of magnetic rigidity of 50–1350 GV is found for a charge range from helium to iron. This conclusion is statistically reliable with significance better than 3.2 standard deviations. The results are discussed and compared to the data of other modern experiments.

  4. Large-N Seismic Deployment at the Source Physics Experiment (SPE) Site

    NASA Astrophysics Data System (ADS)

    Chen, T.; Snelson, C. M.; Mellors, R. J.; Pitarka, A.

    2015-12-01

    The Source Physics Experiment (SPE) is multi-institutional and multi-disciplinary project that consists of a series of chemical explosion experiments at the Nevada National Security Site. The goal of SPE is to understand the complicated effect of earth structures on source energy partitioning and seismic wave propagation, develop and validate physics-based monitoring, and ultimately better discriminate low-yield nuclear explosions from background seismicity. Deployment of a large number of seismic sensors is planned for SPE to image the full 3-D wavefield with about 500 three-component sensors and 500 vertical component sensors. This large-N seismic deployment will operate near the site of SPE-5 shot for about one month, recording the SPE-5 shot, ambient noise, and additional controlled-sources. This presentation focuses on the design of the large-N seismic deployment. We show how we optimized the sensor layout based on the geological structure and experiment goals with a limited number of sensors. In addition, we will also show some preliminary record sections from deployment. This work was conducted under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy.

  5. Experiments on liquid-metal fast breeder reactor aerosol source terms after severe accidents

    SciTech Connect

    Berthoud, G.; Longest, A.W.; Wright, A.L.; Schutz, W.P.

    1988-05-01

    In the extremely unlikely event of a liquid-metal fast breeder reactor core disruptive accident, expanding core material or sodium vapor inside the sodium pool may cause leaks in the vessel head and transport of radioactive material, mostly aerosols, in one large bubble or several smaller bubbles under energetic conditions to the cover gas and through leaks to the inner containment (''instantaneous source term''). Out-of-pile experiments on bubble expansion from a pressurized source inside a liquid (water or sodium) and related phenomena like heat transfer, condensation, entrainment, rise, and aerosol transport were carried out in France and the United States and are continuing in the Federal Republic of Germany. Parameters and results of these experiments are described and discussed, mainly concerning the aerosol problem. It appears that several mechanisms exist for a very efficient removal of particles from the bubble. Retention factors larger than 10,000 were found in most cases. In addition, a short survey is given of French and German experiments on fuel and fission product release from evaporating or burning sodium pools (delayed source term).

  6. College Student Environmental Activism: How Experiences and Identities Influence Environmental Activism Approaches

    ERIC Educational Resources Information Center

    King, Laura A. H.

    2016-01-01

    College student environmental activism is one way students civically engage in addressing social issues. This study explores the environmental activism of twelve college students and how their experiences outside of college and in college influenced their activism. In addition, how students' identities influenced their approach to activism was…

  7. Decision-Making in Flight with Different Convective Weather Information Sources: Preliminary Results from the Langley CoWS Experiment (COnvective Weather Sources)

    NASA Technical Reports Server (NTRS)

    Chamberlain, Jim; Latorella, Kara

    2003-01-01

    This viewgraph presentation provides information on an airborne experiment designed to test the decision making of pilots receiving different sources of meteorological data. The presentation covers the equipment used in the COnvective Weather Sources (CoWS) Experiment), including the information system and display devices available to some of the subjects. It also describes the experiment, which featured teams of general aviation pilots, who were onboard but did not actually fly the aircraft used in the experiment. The presentation includes the results of a survey of the subjects' confidence.

  8. Dual diagnosis, as described by those who experience the disorder: using the Internet as a source of data.

    PubMed

    Edward, Karen-Leigh; Robins, Alan

    2012-12-01

    The complexity of providing treatment for people with dual diagnosis is well recognized. For the purpose of this paper, the World Health Organization definition of dual diagnosis was used; that is, a person diagnosed with an alcohol or drug use problem in addition to mental illness. This research explored the personal narratives of those who experience dual diagnosis using the Internet as a data source. An important consideration in using the Internet as a data source was that Web forums can offer a sense of anonymity, allowing people to share very detailed and personal information, and providing a rich source of qualitative data. The results produced five emergent themes: spiralling out of control - again!, getting help and giving support, treating both the addiction and mental illness, having meaning and being active, and being honest with self and others. The results indicate that individuals who experience dual diagnosis are often left to navigate their personal treatment requirements across two diverse systems, and were generally not satisfied with the conflictual advice received across these two systems (i.e. alcohol and other drug and mental health services). This study has produced valuable insights related to consumer-perceived service barriers and enablers.

  9. High harmonics from solid surfaces as a source of ultra-bright XUV radiation for experiments

    NASA Astrophysics Data System (ADS)

    Hörlein, R.; Nomura, Y.; Osterhoff, J.; Major, Zs; Karsch, S.; Krausz, F.; Tsakiris, G. D.

    2008-12-01

    The coherent high-order harmonic generation from the interaction of ultra-intense femtosecond laser pulses with solid density plasmas holds promise for tabletop sources of extreme ultraviolet (XUV) and soft x-ray radiation with attosecond duration and unprecedented intensities. Together with the generation of mono-energetic electron beams from gas jets and capillaries and the generation of mono-energetic ions from thin foils, this offers a unique tool box of tabletop-laser-generated radiation sources for a wide range of applications previously only accessible with large-scale accelerator and synchrotron-radiation facilities. Especially, the generation of high harmonics from laser plasmas has the potential of being applied to a wide range of experiments from plasma physics to molecular dynamics. So far the studies addressing the generation of high harmonics from laser-generated overcritical plasma surfaces have concentrated mainly on the characterization of the harmonic beams themselves not considering how, in a next step, these beams could be applied to experiments. In this paper we discuss the generation of surface harmonics with the ATLAS (800 mJ, 40 fs) laser system with the emphasis on the transport, spectral shaping refocusing of the harmonic beams, all of these being absolute prerequisites for multi-shot experiments. We also present considerations for future improvements and possible future experiments exploiting the full potential of high harmonic radiation from solid targets.

  10. Experience and Lessons Learned from Conditioning of Spent Sealed Sources in Singapore - 13107

    SciTech Connect

    Hong, Dae-Seok; Kang, Il-Sik; Jang, Kyung-Duk; Jang, Won-Hyuk; Hoo, Wee-Teck

    2013-07-01

    In 2010, IAEA requested KAERI (Korea Atomic Energy Research Institute) to support Singapore for conditioning spent sealed sources. Those that had been used for a lightning conductor, check source, or smoke detector, various sealed sources had been collected and stored by the NEA (National Environment Agency) in Singapore. Based on experiences for the conditioning of Ra-226 sources in some Asian countries since 2000, KAERI sent an expert team to Singapore for the safe management of spent sealed sources in 2011. As a result of the conditioning, about 575.21 mCi of Am-241, Ra-226, Co-60, and Sr-90 were safely conditioned in 3 concrete lining drums with the cooperation of the KAERI expert team, the IAEA supervisor, the NEA staff and local laborers in Singapore. Some lessons were learned during the operation: (1) preparations by a local authority are very helpful for an efficient operation, (2) a preliminary inspection by an expert team is helpful for the operation, (3) brief reports before and after daily operation are useful for communication, and (4) a training opportunity is required for the sustainability of the expert team. (authors)

  11. Development of a compact laser-produced plasma soft X-ray source for radiobiology experiments

    NASA Astrophysics Data System (ADS)

    Adjei, Daniel; Ayele, Mesfin Getachew; Wachulak, Przemyslaw; Bartnik, Andrzej; Wegrzynski, Łukasz; Fiedorowicz, Henryk; Vyšín, Luděk; Wiechec, Anna; Lekki, Janusz; Kwiatek, Wojciech M.; Pina, Ladislav; Davídková, Marie; Juha, Libor

    2015-12-01

    A desk-top laser-produced plasma (LPP) source of soft X-rays (SXR) has been developed for radiobiology research. The source is based on a double-stream gas puff target, irradiated with the focused beam of a commercial Nd:YAG laser. The source has been optimized to get a maximum photon emission from LPP in the X-ray "water window" spectral wavelength range from 2.3 nm (i.e., an absorption edge of oxygen) to 4.4 nm (i.e., an absorption edge of carbon) (280-540 eV in photon energy units) by using argon gas-puff target and spectral filtering by free-standing thin foils. The present source delivers nanosecond pulses of soft X-rays at a fluence of about 4.2 × 103 photons/μm2/pulse on a sample placed inside the vacuum chamber. In this paper, the source design, radiation output characterization measurements and initial irradiation experiments are described. The source can be useful in addressing observations related to biomolecular, cellular and organisms' sensitivity to pulsed radiation in the "water window", where carbon atoms absorb X-rays more strongly than the oxygen, mostly present in water. The combination of the SXR source and the radiobiology irradiation layout, reported in this article, make possible a systematic investigation of relationships between direct and indirect action of ionizing radiation, an increase of a local dose in carbon-rich compartments of the cell (e.g., lipid membranes), an experimental estimation of a particular role of the Auger effect (in particular in carbon atoms) in the damage to biological systems, and the study of ionization/excitation-density (LET - Linear Energy Transfer) and dose-rate effects in radiobiology.

  12. ArrayNinja: An Open Source Platform for Unified Planning and Analysis of Microarray Experiments

    PubMed Central

    Dickson, B.M.; Cornett, E.M.; Ramjan, Z.; Rothbart, S.B.

    2017-01-01

    Microarray-based proteomic platforms have emerged as valuable tools for studying various aspects of protein function, particularly in the field of chromatin biochemistry. Microarray technology itself is largely unrestricted in regard to printable material and platform design, and efficient multidimensional optimization of assay parameters requires fluidity in the design and analysis of custom print layouts. This motivates the need for streamlined software infrastructure that facilitates the combined planning and analysis of custom microarray experiments. To this end, we have developed ArrayNinja as a portable, open source, and interactive application that unifies the planning and visualization of microarray experiments and provides maximum flexibility to end users. Array experiments can be planned, stored to a private database, and merged with the imaged results for a level of data interaction and centralization that is not currently attainable with available microarray informatics tools. PMID:27423857

  13. EEG alpha activity and hallucinatory experience during sensory deprivation.

    PubMed

    Hayashi, M; Morikawa, T; Hori, T

    1992-10-01

    The relationship between hallucinatory experiences under sensory deprivation and EEG alpha activities was studied. Each of seven male students lived alone in an air conditioned, soundproof dark room for 72 hours. When hallucinatory experiences occurred, the students pressed a button at once. If they could not press the button during the experience, they were required to press it two times when the hallucinatory experience was finished. Spectral analysis was performed on the consecutive EEG samples from just before button-presses to 10 min. before them, and the average alpha band amplitudes were obtained for the four epochs (0-.5, .5-2, 2-5, 5-10 min.). For the single button-presses, the amplitude of alpha band increased 2 min. before the button-presses. Right-hemisphere EEG activation was observed in the occipital area for the double button-presses. The results suggest an association between the hallucinatory experiences under sensory deprivation and the amount of EEG alpha activity.

  14. Imaging magnetic sources in the presence of superconducting surfaces : model&experiment

    SciTech Connect

    Matlachov, A. N.; Espy, M. A.; Volegov, P.; Flynn, E. R.; Maharajh, K.; Kraus, Robert H., Jr.

    2001-01-01

    The forward physics model describing the effect of a superconducting surface on the magnetic field distribution resulting from specific magnetic sources has numerous applications ranging from basic physics experiments to large superconducting magnets used in energy storage and magnetic resonance imaging. In this paper, we describe the novel application of a superconducting imaging surface (SIS) to enhance the performance of systems designed to directly observe and localize human brain function. Magnetoencephalography (MEG) measures the weak magnetic fields emanating from the brain as a direct consequence of the neuronal currents resulting from brain function[1]. The extraordinarily weak magnetic fields are measured by an array of SQUID (Superconducting QUantum Interference Device) sensors. The position and vector characteristics of these neuronal sources can be estimated from the inverse solution of the field distribution at the surface of the head. In addition, MEG temporal resolution is unsurpassed by any other method currently used for brain imaging. Although MEG source reconstruction is limited by solutions of the electromagnetic inverse problem, constraints used for source localization produce reliable results. A novel MEG system incorporating a SIS has been designed and built at Los Alamos with the goal of dramatically improving source localization accuracy while mitigating limitations of current systems (e.g. low signal-to-noise, cost, bulk). We incorporate shielding and source field measurement into an integrated design and combine the latest SQUID and data acquisition technology. The Los Alamos MEG system is based on the principal that fields from nearby sources measured by a SQUID sensor array while the SIS simultaneously shields the sensor array from distant noise fields. In general, Meissner currents flow in the surface of superconductors, preventing any significant penetration of magnetic fields. A hemispherical SIS with a brim, or helmet, surrounds

  15. Specification of High Activity Gamma-Ray Sources.

    ERIC Educational Resources Information Center

    International Commission on Radiation Units and Measurements, Washington, DC.

    The report is concerned with making recommendations for the specifications of gamma ray sources, which relate to the quantity of radioactive material and the radiation emitted. Primary consideration is given to sources in teletherapy and to a lesser extent those used in industrial radiography and in irradiation units used in industry and research.…

  16. High Resolution Regional Attenuation for the Source Physics Experiment Using Multiphase Inversion

    NASA Astrophysics Data System (ADS)

    Pyle, M. L.; Walter, W. R.; Pasyanos, M.

    2015-12-01

    Seismic event amplitude measurement plays a critical role in the discrimination between earthquakes and explosions. An accurate 2D model of the attenuation experienced by seismic waves traveling through the earth is especially important for reasonable amplitude estimation at small event-to-station distances. In this study, we investigate the detailed attenuation structure in the region around southern Nevada as part of the Source Physics Experiment (SPE). The SPE consists of a series of chemical explosions at the Nevada National Security Site (NNSS) designed to improve our understanding of explosion physics and enable better modeling of explosion sources. Phase I of the SPE is currently being conducted in the Climax Stock Granite and Phase II will move to a contrasting dry alluvium geology. A high-resolution attenuation model will aid in the modeling efforts of these experiments. To improve our understanding of the propagation of energy from sources in the area to local and regional stations in the western U.S., we invert regional phases Pn, Pg, and Lg to examine the crust and upper mantle attenuation structure of southern Nevada and the surrounding region. We consider observed amplitudes as the frequency-domain product of a source term, a site term, a geometrical spreading term, and an attenuation (Q) term (e.g. Walter and Taylor, 2001). Initially we take a staged approach to first determine the best 1D Q values; next we calculate source terms using the 1D model, and finally we solve for the best 2D Q parameters and site terms considering all frequencies simultaneously. Our preliminary results agree generally with those from the continent-wide study by Pasyanos (2013). With additional data we are working to develop a more detailed and higher frequency model of the region as well as move toward a fully non-linear inversion.

  17. Report on active and planned spacecraft and experiments

    NASA Technical Reports Server (NTRS)

    Brecht, J. J. (Editor)

    1974-01-01

    Information dealing with active and planned spacecraft and experiments known to the National Space Science Data Center (NSSDC) is presented. Included is information concerning a wide range of disciplines: astronomy, earth sciences, meteorology, planetary sciences, aeronomy, particles and fields, solar physics, life sciences, and material sciences. These spacecraft represent the efforts and funding of individual countries, as well as cooperative arrangements among different countries.

  18. Physical Activity Experiences of Boys with and without ADHD

    ERIC Educational Resources Information Center

    Harvey, William J.; Reid, Greg; Bloom, Gordon A.; Staples, Kerri; Grizenko, Natalie; Mbekou, Valentin; Ter-Stepanian, Marina; Joober, Ridha

    2009-01-01

    Physical activity experiences of 12 age-matched boys with and without attention-deficit hyperactivity disorder (ADHD) were explored by converging information from Test of Gross Motor Development-2 assessments and semistructured interviews. The knowledge-based approach and the inhibitory model of executive functions, a combined theoretical lens,…

  19. Young Asian Women Experiences of the Summer Activities Initiative.

    ERIC Educational Resources Information Center

    Kirby, Laura

    2002-01-01

    Interviews and observations focused on experiences of 15 young Asian women at a 5-day summer adventure program in southern England. Participants seemed bored with presentations about future career options, activities lost their challenge through repetition, and debriefing was weak. However, the women connected with the transferable skills of trust…

  20. Report on active and planned spacecraft and experiments

    NASA Technical Reports Server (NTRS)

    Vette, J. I. (Editor); Vostreys, R. W. (Editor)

    1977-01-01

    Information concerning active and planned spacecraft and experiments is reported. The information includes a wide range of disciplines: astronomy, earth sciences, meteorology, planetary sciences, aeronomy, particles and fields, solar physics, life sciences, and material sciences. These spacecraft projects represent the efforts and funding of individual countries as well as cooperative arrangements among different countries.

  1. Chemistry: Experiments, Demonstrations and Other Activities Suggested for Chemistry.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    This publication is a handbook used in conjunction with the course of study in chemistry developed through the New York State Education Department and The University of the State of New York. It contains experiments, demonstrations, and other activities for a chemistry course. Areas covered include the science of chemistry, the atomic structure of…

  2. Report on active and planned spacecraft and experiments

    NASA Technical Reports Server (NTRS)

    Littlefield, R. G. (Editor)

    1983-01-01

    Information concerning active and planned spacecraft and experiments is included. The information covers a wide range of scientific disciplines: astronomy, earth sciences, meteorology, planetary sciences, aeronomy, particles and fields, solar physics, life sciences, and material sciences. These spacecraft projects represent the efforts and fundng of individual countries as well as cooperative arrangements among different countries.

  3. Report on active and planned spacecraft and experiments

    NASA Technical Reports Server (NTRS)

    Vette, J. I. (Editor); Vostreys, R. W. (Editor); Horowitz, R. (Editor)

    1978-01-01

    Information is presented, concerning active and planned spacecraft and experiments known to the National Space Science Data Center. The information included a wide range of disciplines: astronomy, earth sciences, meteorology, planetary sciences, aeronomy, particles and fields, solar physics, life sciences, and material sciences. These spacecraft projects represented the efforts and funding of individual countries as well as cooperative arrangements among different countries.

  4. Active radiometric calorimeter for absolute calibration of radioactive sources

    SciTech Connect

    Stump, K.E.; DeWerd, L.A.; Rudman, D.A.; Schima, S.A.

    2005-03-01

    This report describes the design and initial noise floor measurements of a radiometric calorimeter designed to measure therapeutic medical radioactive sources. The instrument demonstrates a noise floor of approximately 2 nW. This low noise floor is achieved by using high temperature superconducting (HTS) transition edge sensor (TES) thermometers in a temperature-control feedback loop. This feedback loop will be used to provide absolute source calibrations based upon the electrical substitution method. Other unique features of the calorimeter are (a) its ability to change sources for calibration without disrupting the vacuum of the instrument, and (b) the ability to measure the emitted power of a source in addition to the total contained source power.

  5. Nonpoint sources as external threats to coastal water quality: lessons from Park Service experience

    USGS Publications Warehouse

    Burroughs, R.H.

    1993-01-01

    Program design for nonpoint source control was considered through an analogous problem, external threats to national parks. Nonpoint sources are diffuse land activities that degrade water quality, and recent federal legislation seeks to limit them in coastal areas. External threats occur outside a park boundary but affect the purposes for, or resources within, a park. They have been subject to federal management for many decades. Nonpoint sources are a class of external threat. Therefore, programs to limit them should consider techniques used in part protection. These park techniques include 'hard approaches', which rely on power, usually through legal devices, and 'soft approaches', which utilize shared values and objectives. A linked approach, as exemplified at the Cape Cod National Seashore, appears most promising. In a linked approach, if a soft approach fails, the manager of the protected unit is empowered to take an alternative hard action to protect the resource.

  6. Skyline: an open source document editor for creating and analyzing targeted proteomics experiments

    PubMed Central

    MacLean, Brendan; Tomazela, Daniela M.; Shulman, Nicholas; Chambers, Matthew; Finney, Gregory L.; Frewen, Barbara; Kern, Randall; Tabb, David L.; Liebler, Daniel C.; MacCoss, Michael J.

    2010-01-01

    Summary: Skyline is a Windows client application for targeted proteomics method creation and quantitative data analysis. It is open source and freely available for academic and commercial use. The Skyline user interface simplifies the development of mass spectrometer methods and the analysis of data from targeted proteomics experiments performed using selected reaction monitoring (SRM). Skyline supports using and creating MS/MS spectral libraries from a wide variety of sources to choose SRM filters and verify results based on previously observed ion trap data. Skyline exports transition lists to and imports the native output files from Agilent, Applied Biosystems, Thermo Fisher Scientific and Waters triple quadrupole instruments, seamlessly connecting mass spectrometer output back to the experimental design document. The fast and compact Skyline file format is easily shared, even for experiments requiring many sample injections. A rich array of graphs displays results and provides powerful tools for inspecting data integrity as data are acquired, helping instrument operators to identify problems early. The Skyline dynamic report designer exports tabular data from the Skyline document model for in-depth analysis with common statistical tools. Availability: Single-click, self-updating web installation is available at http://proteome.gs.washington.edu/software/skyline. This web site also provides access to instructional videos, a support board, an issues list and a link to the source code project. Contact: brendanx@u.washington.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:20147306

  7. Data Release Report for Source Physics Experiment 1 (SPE-1), Nevada National Security Site

    SciTech Connect

    Townsend, Margaret; Mercadente, Jennifer

    2014-04-28

    The first Source Physics Experiment shot (SPE-1) was conducted in May 2011. The explosive source was a ~100-kilogram TNT-equivalent chemical set at a depth of 60 meters. It was recorded by an extensive set of instrumentation that includes sensors both at near-field (less than 100 meters) and far-field (more than 100 meters) distances. The near-field instruments consisted of three-component accelerometers deployed in boreholes around the shot and a set of singlecomponent vertical accelerometers on the surface. The far-field network comprised a variety of seismic and acoustic sensors, including short-period geophones, broadband seismometers, three-component accelerometers, and rotational seismometers at distances of 100 meters to 25 kilometers. This report coincides with the release of these data for analysts and organizations that are not participants in this program. This report describes the first Source Physics Experiment and the various types of near-field and far-field data that are available.

  8. NSLS 2007 Activity Report (National Synchrotron Light Source Activity Report 2007)

    SciTech Connect

    Miller ,L.; Nasta, K.

    2008-05-01

    The National Synchrotron Light Source is one of the world's most productive and cost-effective user facilities. With 2,219 individual users, about 100 more than last year, and a record-high 985 publications, 2007 was no exception. In addition to producing an impressive array of science highlights, which are included in this Activity Report, many NSLS users were honored this year for their scientific accomplishments. Throughout the year, there were major strides in the development of the scientific programs by strengthening strategic partnerships with major research resources and with the Center for Functional Nanomaterials (CFN). Of particular note, the Consortium for Materials Properties Research in Earth Sciences (COMPRES) received renewed funding for the next five years through the National Science Foundation. COMPRES operates four high-pressure NSLS beamlines--X17B2, X17B3, X17C, and U2A--and serves the earth science community as well as the rapidly expanding segment of researchers using high-pressure techniques in materials, chemical, and energy-related sciences. A joint appointment was made between the NSLS and Stony Brook University to further enhance interactions with COMPRES. There was major progress on two key beamline projects outlined in the Five-Year Strategic Plan: the X25 beamline upgrade and the construction of the X9 small angle scattering (SAXS) beamline. The X25 overhaul, which began with the installation of the in-vacuum mini-gap undulator (MGU) in January 2006, is now complete. X25 is once again the brightest beamline for macromolecular crystallography at the NSLS, and in tandem with the X29 undulator beamline, it will keep the NSLS at the cutting edge in this important area of research. Upgrade work associated with the new MGU and the front end for the X9 SAXS beamline--jointly developed by the NSLS and the CFN--also was completed. Beamline X9 will host the SAXS program that currently exists at beamline X21 and will provide new microbeam SAXS

  9. Can Inner Experience Be Apprehended in High Fidelity? Examining Brain Activation and Experience from Multiple Perspectives

    PubMed Central

    Hurlburt, Russell T.; Alderson-Day, Ben; Fernyhough, Charles; Kühn, Simone

    2017-01-01

    We discuss the historical context for explorations of “pristine inner experience,” attempts to apprehend and describe the inner experiences that directly present themselves in natural environments. There is no generally accepted method for determining whether such apprehensions/descriptions should be considered high fidelity. By analogy from musical recording, we present and discuss one strategy for establishing experiential fidelity: the examining of brain activation associated with a variety of experiential perspectives that had not been specified at the time of data collection. We beeped participants in an fMRI scanner at randomly-determined times and recorded time-locked brain activations. We used Descriptive Experience Sampling (DES) to apprehend and describe the participant's experience that was ongoing at each beep. These apprehensions/descriptions were obtained with no specific theoretical perspective or experimental intention when originally collected. If these apprehensions/descriptions were of high fidelity, then these pairings of moments of experience and brain activations should be able to be productively examined and re-examined in multiple ways and from multiple theoretical perspectives. We discuss a small set of such re-examinations and conclude that this strategy is worthy of further examination. PMID:28191000

  10. Preseismic Velocity Changes Observed from Active Source Monitoringat the Parkfield SAFOD Drill Site

    SciTech Connect

    Daley, Thomas; Niu, Fenglin; Silver, Paul G.; Daley, Thomas M.; Cheng, Xin; Majer, Ernest L.

    2008-06-10

    Measuring stress changes within seismically active fault zones has been a long-sought goal of seismology. Here we show that such stress changes are measurable by exploiting the stress dependence of seismic wave speed from an active source cross-well experiment conducted at the SAFOD drill site. Over a two-month period we observed an excellent anti-correlation between changes in the time required for an S wave to travel through the rock along a fixed pathway--a few microseconds--and variations in barometric pressure. We also observed two large excursions in the traveltime data that are coincident with two earthquakes that are among those predicted to produce the largest coseismic stress changes at SAFOD. Interestingly, the two excursions started approximately 10 and 2 hours before the events, respectively, suggesting that they may be related to pre-rupture stress induced changes in crack properties, as observed in early laboratory studies.

  11. Toward a Mechanistic Source Term in Advanced Reactors: A Review of Past Incidents, Experiments, and Analyses

    SciTech Connect

    Bucknor, Matthew; Brunett, Acacia J.; Grabaskas, David

    2016-04-17

    In 2015, as part of a Regulatory Technology Development Plan (RTDP) effort for sodium-cooled fast reactors (SFRs), Argonne National Laboratory investigated the current state of knowledge of source term development for a metal-fueled, pool-type SFR. This paper provides a summary of past domestic metal-fueled SFR incidents and experiments and highlights information relevant to source term estimations that were gathered as part of the RTDP effort. The incidents described in this paper include fuel pin failures at the Sodium Reactor Experiment (SRE) facility in July of 1959, the Fermi I meltdown that occurred in October of 1966, and the repeated melting of a fuel element within an experimental capsule at the Experimental Breeder Reactor II (EBR-II) from November 1967 to May 1968. The experiments described in this paper include the Run-Beyond-Cladding-Breach tests that were performed at EBR-II in 1985 and a series of severe transient overpower tests conducted at the Transient Reactor Test Facility (TREAT) in the mid-1980s.

  12. Perceiving active listening activates the reward system and improves the impression of relevant experiences.

    PubMed

    Kawamichi, Hiroaki; Yoshihara, Kazufumi; Sasaki, Akihiro T; Sugawara, Sho K; Tanabe, Hiroki C; Shinohara, Ryoji; Sugisawa, Yuka; Tokutake, Kentaro; Mochizuki, Yukiko; Anme, Tokie; Sadato, Norihiro

    2015-01-01

    Although active listening is an influential behavior, which can affect the social responses of others, the neural correlates underlying its perception have remained unclear. Sensing active listening in social interactions is accompanied by an improvement in the recollected impressions of relevant experiences and is thought to arouse positive feelings. We therefore hypothesized that the recognition of active listening activates the reward system, and that the emotional appraisal of experiences that had been subject to active listening would be improved. To test these hypotheses, we conducted functional magnetic resonance imaging (fMRI) on participants viewing assessments of their own personal experiences made by evaluators with or without active listening attitude. Subjects rated evaluators who showed active listening more positively. Furthermore, they rated episodes more positively when they were evaluated by individuals showing active listening. Neural activation in the ventral striatum was enhanced by perceiving active listening, suggesting that this was processed as rewarding. It also activated the right anterior insula, representing positive emotional reappraisal processes. Furthermore, the mentalizing network was activated when participants were being evaluated, irrespective of active listening behavior. Therefore, perceiving active listening appeared to result in positive emotional appraisal and to invoke mental state attribution to the active listener.

  13. Performance of active vibration control technology: the ACTEX flight experiments

    NASA Astrophysics Data System (ADS)

    Nye, T. W.; Manning, R. A.; Qassim, K.

    1999-12-01

    This paper discusses the development and results of two intelligent structures space-flight experiments, each of which could affect architecture designs of future spacecraft. The first, the advanced controls technology experiment I (ACTEX I), is a variable stiffness tripod structure riding as a secondary payload on a classified spacecraft. It has been operating well past its expected life since becoming operational in 1996. Over 60 on-orbit experiments have been run on the ACTEX I flight experiment. These experiments form the basis for in-space controller design problems and for concluding lifetime/reliability data on the active control components. Transfer functions taken during the life of ACTEX I have shown consistent predictability and stability in structural behavior, including consistency with those measurements taken on the ground prior to a three year storage period and the launch event. ACTEX I can change its modal characteristics by employing its dynamic change mechanism that varies preloads in portions of its structure. Active control experiments have demonstrated maximum vibration reductions of 29 dB and 16 dB in the first two variable modes of the system, while operating over a remarkable on-orbit temperature range of -80 °C to 129 °C. The second experiment, ACTEX II, was successfully designed, ground-tested, and integrated on an experimental Department of Defense satellite prior to its loss during a launch vehicle failure in 1995. ACTEX II also had variable modal behavior by virtue of a two-axis gimbal and added challenges of structural flexibility by being a large deployable appendage. Although the loss of ACTEX II did not provide space environment experience, ground testing resulted in space qualifying the hardware and demonstrated 21 dB, 14 dB, and 8 dB reductions in amplitude of the first three primary structural modes. ACTEX II could use either active and/or passive techniques to affect vibration suppression. Both experiments trailblazed

  14. A study of outflow activity around EGO sources

    NASA Astrophysics Data System (ADS)

    Farina, C.; Paron, S.; Ortega, M.; Astort, A.; Rubio, M.

    2013-06-01

    Extended green objects (EGOs) were identified in Spitzer-IRAC images as they present a particular extended "green" emission at 4.5 μm, hence their name. An EGO is probably a massive young stellar object driving outflows, with the extended emission at 4.5 μm likely due to H2 lines and CO band-heads excited by the shock of the outflow propagating in the interstellar medium. Therefore, the dedicated observation and study of EGOs and their close environments can provide additional insight into our understanding of massive-star formation processes. In this context, based on previous studies we have selected a set of particularly interesting EGOs with the aim of analysing and characterising their outflow activity and its impact on the interstellar medium around them. This is a work in progress in which new observations at molecular and near-infrared wavelengths have recently been carried out towards some of the selected EGOs and more observations will be done in the following semesters. Here we report the results obtained so far from the data analysis of the images towards EGO, G45.47+0.05 and EGO, G35.04-0.47. For these two targets the molecular line observations were acquired using the Atacama Submillimiter Telescope Experiment (ASTE) and the near-infrared images for EGO, G45.47+0.05 were taken with Gemini-NIRI. The near future plans of this project include new images from WHT-LIRIS for EGO, G035.20-0.74 and EGO, G035.03+0.35.

  15. Modeling the Infrasound Acoustic Signal Generation of Underground Explosions at the Source Physics Experiment

    NASA Astrophysics Data System (ADS)

    Whitaker, R. W.; Jones, K. R.; Arrowsmith, S.

    2013-12-01

    One of the primary goals of the Source Physics Experiment is to improve upon and develop new physics based models for underground nuclear explosions using scaled, underground chemical explosions as proxies. Jones et. al, (AGU 2012) previously presented results describing the use of the Rayleigh integral (RI) to model the source region of the SPE explosions. While these results showed that the source region could be modeled using the RI, there were some complexities in the produced, synthetic waveforms that were unaccounted for when compared to the observed data. To gain insight into these complexities and to verify the results of the RI method, we used CAVEAT, a two-dimensional computational fluid dynamics, time-domain finite-difference code developed at Los Alamos National Labs (LANL). CAVEAT has been used in the solution of high speed and low speed fluid problems. While the RI uses the observed acceleration records from the 12 vertical surface accelerometers installed above ground zero, CAVEAT employs a synthetic source-time function, based on the acceleration records, that varies with range and time. This model provides a velocity boundary condition at the bottom boundary of the CAVEAT computation mesh that drives the atmospheric pressure wave into the atmosphere.

  16. A tunable, linac based, intense, broad-band THz source forpump-probe experiments

    SciTech Connect

    Schmerge, J.; Adolphsen, C.; Corbett, J.; Dolgashev, V.; Durr, H.; Fazio, M.; Fisher, A.; Frisch, J.; Gaffney, K.; Guehr, M.; Hastings, J.; Hettel, B.; Hoffmann, M.; Hogan, M.; Holtkamp, N.; Huang, X.; Huang, Z.; Kirchmann, P.; LaRue, J.; Limborg, C.; Lindenberg, A.; Loos, H.; Maxwell, T.; Nilsson, A.; Raubenheimer, T.; Reis, D.; Ross, M.; Shen, Z. -X.; Stupakov, G.; Tantawi, S.; Tian, K.; Wu, Z.; Xiang, D.; Yakimenko, V.

    2015-02-02

    We propose an intense THz source with tunable frequency and bandwidth that can directly interact with the degrees of freedom that determine the properties of materials and thus provides a new tool for controlling and directing these ultrafast processes as well as aiding synthesis of new materials with new functional properties. This THz source will broadly impact our understanding of dynamical processes in matter at the atomic-scale and in real time. Established optical pumping schemes using femtosecond visible frequency laser pulses for excitation are extended into the THz frequency regime thereby enabling resonant excitation of bonds in correlated solid state materials (phonon pumping), to drive low energy electronic excitations, to trigger surface chemistry reactions, and to all-optically bias a material with ultrashort electric fields or magnetic fields. A linac-based THz source can supply stand-alone experiments with peak intensities two orders of magnitude stronger than existing laser-based sources, but when coupled with atomic-scale sensitive femtosecond x-ray probes it opens a new frontier in ultrafast science with broad applications to correlated materials, interfacial and liquid phase chemistry, and materials in extreme conditions.

  17. Proposed neutron activation analysis facilities in the Advanced Neutron Source

    SciTech Connect

    Robinson, L.; Dyer, F.F.; Emery, J.F.

    1990-01-01

    A number of analytical chemistry experimental facilities are being proposed for the Advanced Neutron Source. Experimental capabilities will include gamma-ray analysis and neutron depth profiling. This paper describes the various systems proposed and some of their important characteristics.

  18. Volcanic eruption source parameters from active and passive microwave sensors

    NASA Astrophysics Data System (ADS)

    Montopoli, Mario; Marzano, Frank S.; Cimini, Domenico; Mereu, Luigi

    2016-04-01

    It is well known, in the volcanology community, that precise information of the source parameters characterising an eruption are of predominant interest for the initialization of the Volcanic Transport and Dispersion Models (VTDM). Source parameters of main interest would be the top altitude of the volcanic plume, the flux of the mass ejected at the emission source, which is strictly related to the cloud top altitude, the distribution of volcanic mass concentration along the vertical column as well as the duration of the eruption and the erupted volume. Usually, the combination of a-posteriori field and numerical studies allow constraining the eruption source parameters for a given volcanic event thus making possible the forecast of ash dispersion and deposition from future volcanic eruptions. So far, remote sensors working at visible and infrared channels (cameras and radiometers) have been mainly used to detect, track and provide estimates of the concentration content and the prevailing size of the particles propagating within the ash clouds up to several thousand of kilometres far from the source as well as track back, a-posteriori, the accuracy of the VATDM outputs thus testing the initial choice made for the source parameters. Acoustic wave (infrasound) and microwave fixed scan radar (voldorad) were also used to infer source parameters. In this work we want to put our attention on the role of sensors operating at microwave wavelengths as complementary tools for the real time estimations of source parameters. Microwaves can benefit of the operability during night and day and a relatively negligible sensitivity to the presence of clouds (non precipitating weather clouds) at the cost of a limited coverage and larger spatial resolution when compared with infrared sensors. Thanks to the aforementioned advantages, the products from microwaves sensors are expected to be sensible mostly to the whole path traversed along the tephra cloud making microwaves particularly

  19. Laboratory experiments designed to provide limits on the radionuclide source term for the NNWSI Project

    SciTech Connect

    Oversby, V.M.; McCright, R.D.

    1984-11-01

    The Nevada Nuclear Waste Storage Investigations Project is investigating the suitability of the tuffaceous rocks at Yucca Mountain Nevada for potential use as a high-level nuclear waste repository. The horizon under investigation lies above the water table, and therefore offers a setting that differs substantially from other potential repository sites. The unsaturated zone environment allows a simple, but effective, waste package design. The source term for radionuclide release from the waste package will be based on laboratory experiments that determine the corrosion rates and mechanisms for the metal container and the dissolution rate of the waste form under expected long term conditions. This paper describes the present status of laboratory results and outlines the approach to be used in combining the data to develop a realistic source term for release of radionuclides from the waste package. 16 refs., 3 figs., 1 tab.

  20. Applications of an 88Y/Be photoneutron calibration source to dark matter and neutrino experiments.

    PubMed

    Collar, J I

    2013-05-24

    The low-energy monochromatic neutron emission from an (88)Y/Be source can be exploited to mimic the few keV(nr) nuclear recoils expected from low-mass weakly interacting massive particles and coherent scattering of neutrinos off nuclei. Using this source, a experiment, resulting in a marked increase of its tension with other searches, under the standard set of phenomenological assumptions. The method is illustrated for other target materials (superheated and noble liquids).

  1. Matter under extreme conditions experiments at the Linac Coherent Light Source

    NASA Astrophysics Data System (ADS)

    Glenzer, S. H.; Fletcher, L. B.; Galtier, E.; Nagler, B.; Alonso-Mori, R.; Barbrel, B.; Brown, S. B.; Chapman, D. A.; Chen, Z.; Curry, C. B.; Fiuza, F.; Gamboa, E.; Gauthier, M.; Gericke, D. O.; Gleason, A.; Goede, S.; Granados, E.; Heimann, P.; Kim, J.; Kraus, D.; MacDonald, M. J.; Mackinnon, A. J.; Mishra, R.; Ravasio, A.; Roedel, C.; Sperling, P.; Schumaker, W.; Tsui, Y. Y.; Vorberger, J.; Zastrau, U.; Fry, A.; White, W. E.; Hasting, J. B.; Lee, H. J.

    2016-05-01

    The matter in extreme conditions end station at the Linac Coherent Light Source (LCLS) is a new tool enabling accurate pump-probe measurements for studying the physical properties of matter in the high-energy density (HED) physics regime. This instrument combines the world’s brightest x-ray source, the LCLS x-ray beam, with high-power lasers consisting of two nanosecond Nd:glass laser beams and one short-pulse Ti:sapphire laser. These lasers produce short-lived states of matter with high pressures, high temperatures or high densities with properties that are important for applications in nuclear fusion research, laboratory astrophysics and the development of intense radiation sources. In the first experiments, we have performed highly accurate x-ray diffraction and x-ray Thomson scattering measurements on shock-compressed matter resolving the transition from compressed solid matter to a co-existence regime and into the warm dense matter state. These complex charged-particle systems are dominated by strong correlations and quantum effects. They exist in planetary interiors and laboratory experiments, e.g., during high-power laser interactions with solids or the compression phase of inertial confinement fusion implosions. Applying record peak brightness x-rays resolves the ionic interactions at atomic (Ångstrom) scale lengths and measure the static structure factor, which is a key quantity for determining equation of state data and important transport coefficients. Simultaneously, spectrally resolved measurements of plasmon features provide dynamic structure factor information that yield temperature and density with unprecedented precision at micron-scale resolution in dynamic compression experiments. These studies have demonstrated our ability to measure fundamental thermodynamic properties that determine the state of matter in the HED physics regime.

  2. An active thermal control surfaces experiment. [spacecraft temperature determination

    NASA Technical Reports Server (NTRS)

    Wilkes, D. R.; Brown, M. J.

    1979-01-01

    An active flight experiment is described that has the objectives to determine the effects of the low earth natural environment and the Shuttle induced environment on selected thermal control and optical surfaces. The optical and thermal properties of test samples will be measured in-situ using an integrating sphere reflectrometer and using calorimetric methods. This experiment has been selected for the Long Duration Exposure Facility (LDEF) flight which will be carried to orbit by the NASA Space Shuttle. The LDEF will remain in orbit to be picked up by a later Shuttle mission and returned for postflight evaluation.

  3. Analysis and Simulations of Near-Field Ground Motion from Source Physics Experiments (spe)

    NASA Astrophysics Data System (ADS)

    Vorobiev, O.; Xu, H.; Lomov, I.; Herbold, E. B.; Glenn, L. A.; Antoun, T.

    2012-12-01

    This work is focused on analysis of near-field measurements (up to 50-70 m from the source) recorded during Source Physics Experiments SPE1, SPE2 and SPE3 in a granitic formation (the Climax Stock) at the Nevada National Security Site (NNSS). The explosive source used in these experiments is a sensitized heavy ANFO (SHANFO) with a well characterized equation of state. The first event, SPE1, had a yield of 0.1 ton, and was detonated at a 55 m depth of burial in a spherical cavity of about 0.3 m radius. SPE2 and SPE3 had an explosive yield of 1 ton, and they were both detonated in the same cavity at a depth of burial of 45 meters. One of the main goals of these experiments was to investigate the possible mechanisms of shear wave generation in the nonlinear source region. Another objective, relating specifically to the SPE2-SPE3 sequence, was to investigate the effect of damage from one explosion on the response of the medium to a second explosion of the same yield and at the same location as the first explosion. Comparison of the results from SPE2 and SPE3 show some interesting trends. . At the shot level, and at deeper locations, the data from SPE3 seem to agree quite well with SPE2 data, indicating that damage from SPE2 had little to no effect on the response of the medium at these locations. On the other hand, SPE3 data consistently show delay in arrival times as well as reduced wave amplitudes both at 50 ft (16 m) depth and at the ground surface, indicating that above the shot horizon damage from SPE2 had a perceptible effect on the SPE3 near field motions. The quality of the near field data at some gages from the SPE1 and SPE2 events is somewhat questionable, with orientation uncertainties making it difficult to ascertain with confidence the extent to which shear wave generation in the source region affected near field motions. New gages were strategically added to the SPE3 test bed to provide the data needed to address this issue and verify previous

  4. An investigation into active vibration isolation based on predictive control: Part I: Energy source control

    NASA Astrophysics Data System (ADS)

    Fei, H. Z.; Zheng, G. T.; Liu, Z. G.

    2006-09-01

    We report the results of a recent study for the active vibration isolation with whole-spacecraft vibration isolation as an application background into which three parts are divided: (i) energy source control, (ii) nonlinearity and time delay, (iii) implementation and experiment. This paper is the first in this three-part series report, which presents theoretical and experimental investigations into pressure tracking system for energy source control of the isolator. Considering the special environment of the rocket and expected characteristics of actuators, where the isolator will be arranged between the rocket and the spacecraft, pneumatic actuator is proposed to realize the active isolation control. In order to improve the dynamic characteristics of the pneumatic isolator, a cascade control algorithm with double loop structure and predictive control algorithm for pressure tracking control of the inner loop are proposed. In the current paper, a pressure tracking control system using model predictive control (MPC) is studied first. A pneumatic model around pressure work point is built firstly by simplifying the flow equation of valve's orifices and pressure differential equation of the chambers. With this model, an MPC algorithm in the state space is developed, and problems including control parameter choice and command horizon generator are discussed in detail. In addition, by adding model error correction loop and velocity compensation feedback, effects of model uncertainty and volume variation of chambers are reduced greatly. Thus with this design, the real-time pressure tracking can be guaranteed, and so that the active control system can work at higher frequency range.

  5. Calorimetric method for determination of {sup 51}Cr neutrino source activity

    SciTech Connect

    Veretenkin, E. P. Gavrin, V. N.; Danshin, S. N.; Ibragimova, T. V.; Kozlova, Yu. P.; Mirmov, I. N.

    2015-12-15

    Experimental study of nonstandard neutrino properties using high-intensity artificial neutrino sources requires the activity of the sources to be determined with high accuracy. In the BEST project, a calorimetric system for measurement of the activity of high-intensity (a few MCi) neutrino sources based on {sup 51}Cr with an accuracy of 0.5–1% is created. In the paper, the main factors affecting the accuracy of determining the neutrino source activity are discussed. The calorimetric system design and the calibration results using a thermal simulator of the source are presented.

  6. NEAR FIELD MODELING OF SPE1 EXPERIMENT AND PREDICTION OF THE SECOND SOURCE PHYSICS EXPERIMENTS (SPE2)

    SciTech Connect

    Antoun, T; Xu, H; Vorobiev, O; Lomov, I

    2011-10-20

    Motion along joints and fractures in the rock has been proposed as one of the sources of near-source shear wave generation, and demonstrating the validity of this hypothesis is a focal scientific objective of the source physics experimental campaign in the Climax Stock granitic outcrop. A modeling effort has been undertaken by LLNL to complement the experimental campaign, and over the long term provide a validated computation capability for the nuclear explosion monitoring community. The approach involves performing the near-field nonlinear modeling with hydrodynamic codes (e.g., GEODYN, GEODYN-L), and the far-field seismic propagation with an elastic wave propagation code (e.g., WPP). the codes will be coupled together to provide a comprehensive source-to-sensor modeling capability. The technical approach involves pre-test predictions of each of the SPE experiments using their state of the art modeling capabilities, followed by code improvements to alleviate deficiencies identified in the pre-test predictions. This spiral development cycle wherein simulations are used to guide experimental design and the data from the experiment used to improve the models is the most effective approach to enable a transition from the descriptive phenomenological models in current use to the predictive, hybrid physics models needed for a science-based modeling capability for nuclear explosion monitoring. The objective of this report is to describe initial results of non-linear motion predictions of the first two SPE shots in the Climax Stock: a 220-lb shot at a depth of 180 ft (SPE No.1), and a 2570-lb shot at a depth of 150 ft (SPE No.2). The simulations were performed using the LLNL ensemble granite model, a model developed to match velocity and displacement attenuation from HARDHAT, PILE DRIVER, and SHOAL, as well as Russian and French nuclear test data in granitic rocks. This model represents the state of the art modeling capabilities as they existed when the SPE campaign was

  7. Experience with low-alpha lattices at the Diamond Light Source

    NASA Astrophysics Data System (ADS)

    Martin, I. P. S.; Rehm, G.; Thomas, C.; Bartolini, R.

    2011-04-01

    In this paper we present the experience at Diamond Light Source in the design, implementation, and operation of low momentum compaction factor lattices for the generation of short x-ray pulses and coherent THz radiation. The effects of higher-order terms in the expansion of the momentum compaction factor on beam dynamics are reviewed from a theoretical point of view, and the details of both high- and low-emittance solutions at Diamond are discussed. Measurements taken to characterize the lattices under a variety of machine conditions are presented, along with the practical limitations that exist as the momentum compaction factor is made to approach zero.

  8. Development and operating experience of a short-period superconducting undulator at the Advanced Photon Source

    NASA Astrophysics Data System (ADS)

    Ivanyushenkov, Y.; Harkay, K.; Abliz, M.; Boon, L.; Borland, M.; Capatina, D.; Collins, J.; Decker, G.; Dejus, R.; Dooling, J.; Doose, C.; Emery, L.; Fuerst, J.; Gagliano, J.; Hasse, Q.; Jaski, M.; Kasa, M.; Kim, S. H.; Kustom, R.; Lang, J. C.; Liu, J.; Moog, E.; Robinson, D.; Sajaev, V.; Schroeder, K.; Sereno, N.; Shiroyanagi, Y.; Skiadopoulos, D.; Smith, M.; Sun, X.; Trakhtenberg, E.; Vasserman, I.; Vella, A.; Xiao, A.; Xu, J.; Zholents, A.; Gluskin, E.; Lev, V.; Mezentsev, N.; Syrovatin, V.; Tsukanov, V.; Makarov, A.; Pfotenhauer, J.; Potratz, D.

    2015-04-01

    A decade-long effort at the Advanced Photon Source (APS) of Argonne National Laboratory (ANL) on development of superconducting undulators culminated in December 2012 with the installation of the first superconducting undulator "SCU0" into Sector 6 of the APS storage ring. The device was commissioned in January 2013 and has been in user operation since. This paper presents the magnetic and cryogenic design of the SCU0 together with the results of stand-alone cold tests. The initial commissioning and characterization of SCU0 as well as its operating experience in the APS storage ring are described.

  9. Optical Microscopy Characterization for Borehole U-15n#12 in Support of NCNS Source Physics Experiment

    SciTech Connect

    Wilson, Jennifer E.; Sussman, Aviva Joy

    2015-05-22

    Optical microscopy characterization of thin sections from corehole U-15n#12 is part of a larger material characterization effort for the Source Physics Experiment (SPE). The SPE program was conducted in Nevada with a series of explosive tests designed to study the generation and propagation of seismic waves inside Stock quartz monzonite. Optical microscopy analysis includes the following: 1) imaging of full thin sections (scans and mosaic maps); 2) high magnification imaging of petrographic texture (grain size, foliations, fractures, etc.); and 3) measurement of microfracture density.

  10. Takin: An open-source software for experiment planning, visualisation, and data analysis

    NASA Astrophysics Data System (ADS)

    Weber, Tobias; Georgii, Robert; Böni, Peter

    Due to their non-trivial resolution function, measurements on triple-axis spectrometers require extra care from the experimentalist in order to obtain optimal results and to avoid unwanted spurious artefacts. We present a free and open-source software system that aims to ease many of the tasks encountered during the planning phase, in the execution and in data treatment of experiments performed on neutron triple-axis spectrometers. The software is currently in use and has been successfully tested at the MLZ, but can be configured to work with other triple-axis instruments and instrument control systems.

  11. An Analysis of Gamma-ray Burst Time Profiles from the Burst and Transient Source Experiment

    NASA Technical Reports Server (NTRS)

    Lestrade, John Patrick

    1996-01-01

    This proposal requested funding to measure the durations of gamma-ray bursts (GRB) in the 4B catalog as well as to study the structure of GRB time profiles returned by the Burst And Transient Source Experiment (BATSE) on board the Compton Gamma-Ray Observatory. The duration (T90) was to be measured using the same techniques and algorithms developed by the principal investigator for the 3B data. The profile structure studies fall into the two categories of variability and fractal analyses.

  12. Groundwater seepage landscapes with local or distal sources in experiments and on Mars

    NASA Astrophysics Data System (ADS)

    Kleinhans, Maarten; Marra, Wouter A.; Hauber, Ernst; McLelland, Stuart; Murphy, Brendan; Parsons, Daniel

    2015-04-01

    Groundwater has probably played an important role in shaping the surface of Mars. However, the hydrological origin of many typical Martian groundwater features is hampered by the lack of coupling between subsurface processes and surface morphology. Here we focus on the formation of theater-headed valleys. The basic morphology of such valleys can form by erosion through groundwater seepage (sapping), but similar valley morphology can also be the result of overland flow with waterfall-enhanced erosion. This morphological ambiguity complicates the interpretation of such valleys on Mars, but their climatic implications are quite different. Instead of the ambiguous single-valley morphology, metrics of the entire landscape may provide a diagnostic insight into the formative hydrological conditions. We aim to increase our understanding of the formation of entire landscapes by sapping processes and their hydrological implications by providing a framework for morphological metrics of different types of sapping systems. We study sapping from different groundwater sources using large-scale sandbox experiments in the Total Environmental Simulator at the University of Hull and combine our results with previous experiments. Importantly, flow patterns and the resulting landscapes are significantly different for the different sources of groundwater. The main differences are between sapping that results from either local or distal sources. Key results of our study are that groundwater piracy acts on distally-fed valleys, which results in a sparsely dissected landscape of many small and a few large valleys, while locally-fed valleys result in a densely dissected landscape. In addition, distally-fed valleys grow towards the direction of the groundwater source while locally-fed channels grow in a broad range of directions and have strong tendency to bifurcate, particularly on flat horizontal surfaces. To exemplify these differences, we apply the results to aid the interpretation of

  13. Mixing of a point-source indoor pollutant: Numerical predictions and comparison with experiments

    SciTech Connect

    Lobscheid, C.; Gadgil, A.J.

    2002-01-01

    In most practical estimates of indoor pollutant exposures, it is common to assume that the pollutant is uniformly and instantaneously mixed in the indoor space. It is also commonly known that this assumption is simplistic, particularly for point sources, and for short-term or localized indoor exposures. We report computational fluid dynamics (CFD) predictions of mixing time of a point-pulse release of a pollutant in an unventilated mechanically mixed isothermal room. We aimed to determine the adequacy of the standard RANS two-equation ({kappa}-{var_epsilon}) turbulence model to predict the mixing times under these conditions. The predictions were made for the twelve mixing time experiments performed by Drescher et al. (1995). We paid attention to adequate grid resolution, suppression of numerical diffusion, and careful simulation of the mechanical blowers used in the experiments. We found that the predictions are in good agreement with experimental measurements.

  14. An open source/real-time atomic force microscope architecture to perform customizable force spectroscopy experiments.

    PubMed

    Materassi, Donatello; Baschieri, Paolo; Tiribilli, Bruno; Zuccheri, Giampaolo; Samorì, Bruno

    2009-08-01

    We describe the realization of an atomic force microscope architecture designed to perform customizable experiments in a flexible and automatic way. Novel technological contributions are given by the software implementation platform (RTAI-LINUX), which is free and open source, and from a functional point of view, by the implementation of hard real-time control algorithms. Some other technical solutions such as a new way to estimate the optical lever constant are described as well. The adoption of this architecture provides many degrees of freedom in the device behavior and, furthermore, allows one to obtain a flexible experimental instrument at a relatively low cost. In particular, we show how such a system has been employed to obtain measures in sophisticated single-molecule force spectroscopy experiments [Fernandez and Li, Science 303, 1674 (2004)]. Experimental results on proteins already studied using the same methodologies are provided in order to show the reliability of the measure system.

  15. Solar neutrino experiments and a test for neutrino oscillations with radioactive sources

    SciTech Connect

    Cleveland, B.T.; Davis, R. Jr.; Rowley, J.K.

    1980-01-01

    The results of the Brookhaven solar neutrino experiment are given and compared to the most recent standard solar model calculations. The observations are about a factor of 4 below theoretical expectations. In view of the uncertainties involved in the theoretical models of the sun, the discrepancy is not considered to be evidence for neutrino oscillations. The status of the development of a gallium solar neutrino detector is described. Radiochemical neutrino detectors can be used to search for ..nu../sub e/ oscillations by using megacurie sources of monoenergetic neutrinos like /sup 65/Zn. A quantitative evaluation of possible experiments using the Brookhaven chlorine solar neutrino detector and a gallium detector is given. 6 figures, 3 tables.

  16. Fuel plate stability experiments and analysis for the Advanced Neutron Source

    SciTech Connect

    Swinson, W.F.; Battiste, R.L.; Luttrell, C.R.; Yahr, G.T.

    1993-05-01

    The planned reactor for the Advanced Neutron Source (ANS) will use closely spaced arrays of involute-shaped fuel plates that will be cooled by water flowing through the channels between the plates. There is concern that at certain coolant flow velocities, adjacent plates may deflect and touch, with resulting failure of the plates. Experiments have been conducted at the Oak Ridge National Laboratory to examine this potential phenomenon. Results of the experiments and comparison with analytical predictions are reported. The tests were conducted using full-scale epoxy plate models of the aluminum/uranium silicide ANS involute-shaped fuel plates. Use of epoxy plates and model theory allowed lower flow velocities and pressures to explore the potential failure mechanism. Plate deflections and channel pressures as functions of the flow velocity are examined. Comparisons with mathematical models are noted.

  17. Advisory Committee on human radiation experiments. Supplemental Volume 2a, Sources and documentation appendices. Final report

    SciTech Connect

    1995-01-01

    This large document provides a catalog of the location of large numbers of reports pertaining to the charge of the Presidential Advisory Committee on Human Radiation Research and is arranged as a series of appendices. Titles of the appendices are Appendix A- Records at the Washington National Records Center Reviewed in Whole or Part by DoD Personnel or Advisory Committee Staff; Appendix B- Brief Descriptions of Records Accessions in the Advisory Committee on Human Radiation Experiments (ACHRE) Research Document Collection; Appendix C- Bibliography of Secondary Sources Used by ACHRE; Appendix D- Brief Descriptions of Human Radiation Experiments Identified by ACHRE, and Indexes; Appendix E- Documents Cited in the ACHRE Final Report and other Separately Described Materials from the ACHRE Document Collection; Appendix F- Schedule of Advisory Committee Meetings and Meeting Documentation; and Appendix G- Technology Note.

  18. Information-Driven Active Audio-Visual Source Localization.

    PubMed

    Schult, Niclas; Reineking, Thomas; Kluss, Thorsten; Zetzsche, Christoph

    2015-01-01

    We present a system for sensorimotor audio-visual source localization on a mobile robot. We utilize a particle filter for the combination of audio-visual information and for the temporal integration of consecutive measurements. Although the system only measures the current direction of the source, the position of the source can be estimated because the robot is able to move and can therefore obtain measurements from different directions. These actions by the robot successively reduce uncertainty about the source's position. An information gain mechanism is used for selecting the most informative actions in order to minimize the number of actions required to achieve accurate and precise position estimates in azimuth and distance. We show that this mechanism is an efficient solution to the action selection problem for source localization, and that it is able to produce precise position estimates despite simplified unisensory preprocessing. Because of the robot's mobility, this approach is suitable for use in complex and cluttered environments. We present qualitative and quantitative results of the system's performance and discuss possible areas of application.

  19. Factors affecting the pore space transformation during hydrocarbon generation in source rock (shales): laboratory experiment

    NASA Astrophysics Data System (ADS)

    Giliazetdinova, D. R.; Korost, D. V.

    2014-12-01

    Oil and gas generation is a set of processes which taking place in the interior, the processes can't be observable in nature. In the process of dumping the source rock, organic matter is transformed into a complex of high-molecular compounds - precursors of oil and gas (kerogen). Entering of a source column for specific thermobaric conditions, triggers the formation of low molecular weight hydrocarbon compounds. Generation of sufficient quantities of hydrocarbons leads to the primary fluid migration within the source rock. For the experiment were selected mainly siliceous-carbonate composition rocks from Domanic horizon South-Tatar arch. The main aim of experiment was heating the rocks in the pyrolyzer to temperatures which correspond katagenes stages. For monitoring changes in the morphology of the pore space X-ray microtomography method was used. As a result, when was made a study of the composition of mineral and organic content of the rocks, as well as textural and structural features, have been identified that the majority of the rock samples within the selected collection are identical. However, characteristics such as organic content and texture of rocks are different. Thus, the experiment was divided into two parts: 1) the study of the influence of organic matter content on the morphology of the rock in the process of thermal effects; 2) study the effect of texture on the primary migration processes for the same values of organic matter. Also, an additional experiment was conducted to study the dynamics of changes in the structure of the pore space. At each stage of the experiment morphology of altered rocks characterized by the formation of new pores and channels connecting the primary voids. However, it was noted that the samples with a relatively low content of the organic matter had less changes in pore space morphology, in contrast to rocks with a high organic content. At the second stage of the research also revealed that the conversion of the pore

  20. The space experiment CERASP: Definition of a space-suited radiation source and growth conditions for human cells

    NASA Astrophysics Data System (ADS)

    Hellweg, Christine E.; Baumstark-Khan, Christa; Spitta, Luis; Thelen, Melanie; Arenz, Andrea; Franz, Markus; Schulze-Varnholt, Dirk; Berger, Thomas; Reitz, Günther

    The combined action of ionizing radiation and microgravity will continue to influence future space missions, with special risks for astronauts on the Moon surface or for long duration missions to Mars. It has been estimated that on a 3-year mission to Mars about 3% of the bodies' cell nuclei would have been hit by one iron ion with the consequence that nuclear DNA will be heavily damaged. There is increasing evidence that basic cellular functions are sensitive not only to radiation but also to microgravity. DNA repair studies in space on bacteria, yeast cells and human fibroblasts, which were irradiated before, flight, gave contradictory results: from inhibition of repair by microgravity to enhancement, whereas others did not detect any influence of microgravity on repair. The space experiment CERASP (CEllular Responses to RAdiation in SPace) to be performed at the International Space Station (ISS) is aimed to supply basic information on the cellular response in microgravity to radiation applied during flight. It makes use of a recombinant human cell line as reporter for cellular signal transduction modulation by genotoxic environmental conditions. The main biological endpoints under investigation will be gene activation based on enhanced green fluorescent protein (EGFP, originally isolated from the bioluminescent jellyfish Aequorea victoria) expression controlled by a DNA damage-dependent promoter element which reflects the activity of the nuclear factor kappa B (NF- κB) pathway. The NF- κB family of proteins plays a major role in the inflammatory and immune response, cell proliferation and differentiation, anti-apoptosis and tumorgenesis. For radiation exposure during space flight a radiation source has been constructed as damage accumulation by cosmic radiation will certainly be insufficient for analysis. The space experiment specific hardware consists of a specially designed radiation source made up of the β-emitter promethium-147, combined with a

  1. Preliminary experiments on active control of fan noise from a turbofan engine

    NASA Technical Reports Server (NTRS)

    Thomas, R. H.; Burdisso, R. A.; Fuller, C. R.; O'Brien, W. F.

    1993-01-01

    In the preliminary experiments reported here, active acoustic sources positioned around the circumference of a turbofan engine were used to control the fan noise radiated forward through the inlet. The main objective was to demonstrate the potential of active techniques to alleviate the noise pollution that will be produced by the next generation of larger engines. A reduction of up to 19 dB in the radiation directivity was demonstrated in a zone that encompasses a 30-deg angle, near the error sensor, while spillover effects were observed toward the lateral direction. The simultaneous control of two tones was also demonstrated using two identical controllers in a parallel control configuration.

  2. Experiments on the abiotic amplification of optical activity

    NASA Technical Reports Server (NTRS)

    Bonner, W. A.; Blair, N. E.; Dirbas, F. M.

    1981-01-01

    Experiments concerning the physical mechanisms for the abiotic generation and chemical mechanisms for the amplification of optical activity in biological compounds are reviewed. Attention is given to experiments involving the determination of the differential adsorption of racemic amino acids on d- and l-quartz, the asymmetric photolysis of racemic amino acids by circularly polarized light, and the asymmetric radiolysis of solid amino acids by longitudinally polarized electrons, and the enantiomeric enrichments thus obtained are noted. Further experiments on the amplification of the chirality in the polymerization of D, L-amino acid mixtures and the hydrolysis of D-, L-, and D, L-polypeptides are discussed. It is suggested that a repetitive cycle of partial polymerization-hydrolyses may account for the abiotic genesis of optically enriched polypeptides on the primitive earth.

  3. Report on Active and Planned Spacecraft and Experiments. [bibliographies

    NASA Technical Reports Server (NTRS)

    Vostreys, R. W. (Editor); Horwitz, R. (Editor)

    1979-01-01

    Information concerning concerning active and planned spacecraft and experiments known to the National Space Science Data Center are included. The information contains a wide range of disciplines: astronomy, earth sciences, meteorology, planetary sciences, aeronomy, particles and fields, solar physics, life sciences, and material sciences. These spacecraft projects represent the efforts and funding of individual countries as well as cooperative arrangements among different countries. Approximately 850 articles are included.

  4. Active aerodynamic control of wake-airfoil interaction noise - Experiment

    NASA Astrophysics Data System (ADS)

    Simonich, J. C.; Lavrich, P. L.; Sofrin, T. G.; Topol, D. A.

    A proof of concept experiment is conducted that shows the potential for active aerodynamic control of rotor wake/stator interaction noise in a simplified manner. A single airfoil model representing the stator was fitted with a moveable trailing edge flap controlled by a servo motor. The control system moves the motor driven flap in the correct angular displacement phase and rate to reduce the unsteady load on the airfoil during the wake interaction.

  5. Nature experience reduces rumination and subgenual prefrontal cortex activation

    PubMed Central

    Bratman, Gregory N.; Hamilton, J. Paul; Hahn, Kevin S.; Daily, Gretchen C.; Gross, James J.

    2015-01-01

    Urbanization has many benefits, but it also is associated with increased levels of mental illness, including depression. It has been suggested that decreased nature experience may help to explain the link between urbanization and mental illness. This suggestion is supported by a growing body of correlational and experimental evidence, which raises a further question: what mechanism(s) link decreased nature experience to the development of mental illness? One such mechanism might be the impact of nature exposure on rumination, a maladaptive pattern of self-referential thought that is associated with heightened risk for depression and other mental illnesses. We show in healthy participants that a brief nature experience, a 90-min walk in a natural setting, decreases both self-reported rumination and neural activity in the subgenual prefrontal cortex (sgPFC), whereas a 90-min walk in an urban setting has no such effects on self-reported rumination or neural activity. In other studies, the sgPFC has been associated with a self-focused behavioral withdrawal linked to rumination in both depressed and healthy individuals. This study reveals a pathway by which nature experience may improve mental well-being and suggests that accessible natural areas within urban contexts may be a critical resource for mental health in our rapidly urbanizing world. PMID:26124129

  6. Elucidating GPR Response to Biological Activity: Field and Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Tsoflias, G. P.; Schillig, P. C.; McGlashan, M. A.; Roberts, J. A.; Devlin, J. F.

    2010-12-01

    Recent studies of the geophysical signatures of biological processes in earth environments have resulted in the emergent field of “biogeophysics”. The ability to monitor remotely and to quantify active biological processes in the subsurface can have transformative implications to a wide range of investigations, including the bioremediation of contaminated sites. Previous studies have demonstrated that ground-penetrating radar (GPR) can be used to detect the products of microbial activity in the subsurface, such as changes in bulk electrical conductivity, mineral dissolution and precipitation, and the formation of biogenic gas. We present field and laboratory experiments that offer insights to the response of GPR signals to microbial activity. In the field, time-lapse borehole radar tomography was used to monitor biodegradation of a hydrocarbon plume over a period of two years. A dense grid of fourteen borehole pairs monitoring the bioactive region showed radar wave velocity changes of +/-4% and signal attenuation changes of +/-25%. These GPR observations correlated spatially and temporally to independent measurements of groundwater velocity and geochemical variations that occurred in response to microbial activity. The greatest relative changes in radar wave velocity of propagation and attenuation were observed in the region of enhanced bacterial stimulation where biomass growth was the greatest. Radar wave velocity and attenuation decreased during periods of enhanced biostimulation. Two laboratory experiments were conducted to further assess radar response to biomass growth. The first experiment monitored GPR wave transmission through a water-saturated quartz-sand reactor during the course of enhanced biostimulation. Radar wave velocity initially decreased as a result of bacterial activity and subsequently increased rapidly as biogenic gas formed in the pore space. Radar signal attenuation increased during the course of the experiment as a result of an

  7. Assessment of In Situ Time Resolved Shock Experiments at Synchrotron Light Sources*

    NASA Astrophysics Data System (ADS)

    Belak, J.; Ilavsky, J.; Hessler, J. P.

    2005-07-01

    Prior to fielding in situ time resolved experiments of shock wave loading at the Advanced Photon Source, we have performed feasibility experiments assessing a single photon bunch. Using single and poly-crystal Al, Ti, V and Cu shock to incipient spallation on the gas gun, samples were prepared from slices normal to the spall plane of thickness 100-500 microns. In addition, single crystal Al of thickness 500 microns was shocked to incipient spallation and soft recovered using the LLNL e-gun mini-flyer system. The e-gun mini-flyer impacts the sample target producing a 10's ns flat-top shock transient. Here, we present results for imaging, small-angle scattering (SAS), and diffraction. In particular, there is little SAS away from the spall plane and significant SAS at the spall plane, demonstrating the presence of sub-micron voids. * Use of the Advanced Photon Source was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. W-31-109-Eng-38 and work performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

  8. Experiment study of an electron cyclotron resonant ion source based on a tapered resonance cavity

    SciTech Connect

    Yang, Juan; Shi, Feng; Jin, Yizhou; Wang, Yunmin; Komurasaki, Kimiya

    2013-12-15

    Electron cyclotron resonant plasma is one type of magnetised plasma generated by continuous microwave energy. It has the property of high degree of ionization and large volume at low gas pressure, which makes it useful for space propulsion and material processing. This article presents the experiment study of the plasma properties and ion beam extraction from an electron cyclotron resonant ion source based on a tapered resonance cavity. Optical emission spectroscopy based on a simple collisional radiation model was used for plasma diagnosis. Experiment results show that, at microwave power setting ranging from 7.06 to 17.40 W and mass flow rate ranging from 1 to 10 sccm, argon gas can be ionized. Ion beam of 109.1 mA from the ion source can be extracted at microwave power of 30 W, mass flow rate of 10 sccm, and accel voltage of 800 V. The diagnosed plasma temperature and density are 2.4–5.2 eV and 2 × 10{sup 16}–4.8 × 10{sup 17} m{sup −3}, respectively.

  9. Issues in Humanoid Audition and Sound Source Localization by Active Audition

    NASA Astrophysics Data System (ADS)

    Nakadai, Kazuhiro; Okuno, Hiroshi G.; Kitano, Hiroaki

    In this paper, we present an active audition system which is implemented on the humanoid robot "SIG the humanoid". The audition system for highly intelligent humanoids localizes sound sources and recognizes auditory events in the auditory scene. Active audition reported in this paper enables SIG to track sources by integrating audition, vision, and motor movements. Given the multiple sound sources in the auditory scene, SIG actively moves its head to improve localization by aligning microphones orthogonal to the sound source and by capturing the possible sound sources by vision. However, such an active head movement inevitably creates motor noises.The system adaptively cancels motor noises using motor control signals and the cover acoustics. The experimental result demonstrates that active audition by integration of audition, vision, and motor control attains sound source tracking in variety of conditions.onditions.

  10. New activity in the Dorado gamma-ray burst source

    SciTech Connect

    Golenetskii, S.V.; Mazets, E.P.; Aptekar, R.L.

    1982-11-01

    On 1981 December 1 and 1982 January 2 the Cone detectors aboard the Venera 13 and Venera 14 probes recorded ..gamma..-ray transients generated by the same source in Dorado as the notable sequence of events observed 1979 March 5, 6 and April 4, 24.

  11. Washer-Gun Plasma Source for Magnetic Reconnection Experiments on VTF

    NASA Astrophysics Data System (ADS)

    Vrublevskis, A.; Egedal, J.; Fox, W.; Katz, N.; Le, A.; Porkolab, M.

    2008-11-01

    We present an electrostatic washer-gun plasma source for the Versatile Toroidal Facility (VTF). The gun will produce plasmas with densities on the order of 10^18 m-3 and electron temperatures on the order of 10-20 eV. It will extend the range of configurations achievable on VTF since the present plasma production method is limited to configurations with strong toroidal magnetic fields, which are required for microwave-induced electron cyclotron resonant breakdown. The gun is based on the design developed by Sterling Scientific [1] with detailed operation described in [1, 2]. During the gun's operation gas is injected into a channel formed by a stack of alternating molybdenum and boron nitride washers with a molybdenum electrode washer at each end. A voltage from a capacitor bank is applied to these electrodes and breaks down the gas in the channel. The resulting plasma escapes the channel into the main chamber of the experiment. If available we will present data characterizing the argon plasma produced by the device.[1ex] [1] Fiksel G et al. Plasma Sources Sci. Technol. 5 (1996) 78[1ex] [2] Den Hartog D et al. Plasma Sources Sci. Technol. 6 (1997) 492

  12. Residents’ Preferences for Household Kitchen Waste Source Separation Services in Beijing: A Choice Experiment Approach

    PubMed Central

    Yuan, Yalin; Yabe, Mitsuyasu

    2014-01-01

    A source separation program for household kitchen waste has been in place in Beijing since 2010. However, the participation rate of residents is far from satisfactory. This study was carried out to identify residents’ preferences based on an improved management strategy for household kitchen waste source separation. We determine the preferences of residents in an ad hoc sample, according to their age level, for source separation services and their marginal willingness to accept compensation for the service attributes. We used a multinomial logit model to analyze the data, collected from 394 residents in Haidian and Dongcheng districts of Beijing City through a choice experiment. The results show there are differences of preferences on the services attributes between young, middle, and old age residents. Low compensation is not a major factor to promote young and middle age residents accept the proposed separation services. However, on average, most of them prefer services with frequent, evening, plastic bag attributes and without instructor. This study indicates that there is a potential for local government to improve the current separation services accordingly. PMID:25546279

  13. Oscillatory Hydraulic Tomography for NAPL Source Zone Characterization: Sandbox Experiment Demonstration

    NASA Astrophysics Data System (ADS)

    Cardiff, M. A.; Zhou, Y.

    2015-12-01

    Characterizing the distribution and extent of NAPL contamination is an important step in determining appropriate remedial actions. NAPL has a complex mode of transportation in the heterogeneous subsurface domain, which results in difficulties for cleaning up contaminated sites. Here, we use sandbox experiments to demonstrate the effectiveness of Oscillatory Hydraulic Tomography (OHT) for NAPL source zone characterization. In a saturated soil fluid system, the effective hydraulic conductivity (K) is dependent on the soil properties, fluid density, and fluid viscosity. By taking advantage of the differences of fluid properties before and after NAPL intrusion, we can estimate the NAPL source zone migration throughout time by imaging changes in effective K. Using OHT testing, we can derive the K heterogeneities before, during and after NAPL intrusion. NAPL source zone can be located by subtracting the background K from the K tomogram after NAPL intrusion. This approach can avoid mass extraction and injection that occurs in traditional hydraulic tomography approaches while obtain a good estimation of subsurface K heterogeneity and NAPL migration. We believe this method is more cost effective and efficient for field remediation applications.

  14. Characterization and modeling of tungsten source during DIII-D tungsten ring experiments

    NASA Astrophysics Data System (ADS)

    Guterl, J.; Abrams, T.; Elder, D.; Guo, H. Y.

    2016-10-01

    Two tungsten toroidal rings in the DIII-D divertor region were recently exposed to H-mode plasmas. During these experiments, the gross erosion rate of tungsten was spectroscopically monitored for various ELMy H-mode conditions to characterize the tungsten source in the divertor region (see e.g.). However, only a small fraction of tungsten eroded particles eventually exits the divertor region because of the large tungsten local redeposition. Tungsten local redeposition and migration in the vicinity of the tungsten tiles are simulated using the ERO-OEDGE code package to link the effective tungsten source to the measured gross erosion rates between and during ELMs. It is shown that the energy and angular distributions of sputtered tungsten particles strongly affect the ratio of locally redeposited particles and thus the effective tungsten source. Effects of carbon deposition on tungsten tiles between ELMs on the tungsten erosion rate are also discussed. Preliminary studies of divertor screening on long-range tungsten transport in the SOL between ELMs are also presented. Work supported in part by the US Department of Energy under DE-AC05-06OR23100 and DE-FC02-04ER54698.

  15. Undergraduate research experiences support science career decisions and active learning.

    PubMed

    Lopatto, David

    2007-01-01

    The present study examined the reliability of student evaluations of summer undergraduate research experiences using the SURE (Survey of Undergraduate Research Experiences) and a follow-up survey disseminated 9 mo later. The survey further examines the hypothesis that undergraduate research enhances the educational experience of science undergraduates, attracts and retains talented students to careers in science, and acts as a pathway for minority students into science careers. Undergraduates participated in an online survey on the benefits of undergraduate research experiences. Participants indicated gains on 20 potential benefits and reported on career plans. Most of the participants began or continued to plan for postgraduate education in the sciences. A small group of students who discontinued their plans for postgraduate science education reported significantly lower gains than continuing students. Women and men reported similar levels of benefits and similar patterns of career plans. Undergraduate researchers from underrepresented groups reported higher learning gains than comparison students. The results replicated previously reported data from this survey. The follow-up survey indicated that students reported gains in independence, intrinsic motivation to learn, and active participation in courses taken after the summer undergraduate research experience.

  16. Undergraduate Research Experiences Support Science Career Decisions and Active Learning

    PubMed Central

    2007-01-01

    The present study examined the reliability of student evaluations of summer undergraduate research experiences using the SURE (Survey of Undergraduate Research Experiences) and a follow-up survey disseminated 9 mo later. The survey further examines the hypothesis that undergraduate research enhances the educational experience of science undergraduates, attracts and retains talented students to careers in science, and acts as a pathway for minority students into science careers. Undergraduates participated in an online survey on the benefits of undergraduate research experiences. Participants indicated gains on 20 potential benefits and reported on career plans. Most of the participants began or continued to plan for postgraduate education in the sciences. A small group of students who discontinued their plans for postgraduate science education reported significantly lower gains than continuing students. Women and men reported similar levels of benefits and similar patterns of career plans. Undergraduate researchers from underrepresented groups reported higher learning gains than comparison students. The results replicated previously reported data from this survey. The follow-up survey indicated that students reported gains in independence, intrinsic motivation to learn, and active participation in courses taken after the summer undergraduate research experience. PMID:18056301

  17. Heat Transfer by Thermo-capillary Convection -Sounding Rocket COMPERE Experiment SOURCE

    NASA Astrophysics Data System (ADS)

    Dreyer, Michael; Fuhrmann, Eckart

    The sounding rocket COMPERE experiment SOURCE was successfully flown on MASER 11, launched in Kiruna (ESRANGE), May 15th, 2008. SOURCE has been intended to partly ful-fill the scientific objectives of the European Space Agency (ESA) Microgravity Applications Program (MAP) project AO-2004-111 (Convective boiling and condensation). Three parties of principle investigators have been involved to design the experiment set-up: ZARM for thermo-capillary flows, IMFT (Toulouse, France) for boiling studies, EADS Astrium (Bremen, Ger-many) for depressurization. The topic of this paper is to study the effect of wall heat flux on the contact line of the free liquid surface and to obtain a correlation for a convective heat trans-fer coefficient. The experiment has been conducted along a predefined time line. A preheating sequence at ground was the first operation to achieve a well defined temperature evolution within the test cell and its environment inside the rocket. Nearly one minute after launch, the pressurized test cell was filled with the test liquid HFE-7000 until a certain fill level was reached. Then the free surface could be observed for 120 s without distortion. Afterwards, the first depressurization was started to induce subcooled boiling, the second one to start saturated boiling. The data from the flight consists of video images and temperature measurements in the liquid, the solid, and the gaseous phase. Data analysis provides the surface shape versus time and the corresponding apparent contact angle. Computational analysis provides information for the determination of the heat transfer coefficient in a compensated gravity environment where a flow is caused by the temperature difference between the hot wall and the cold liquid. The paper will deliver correlations for the effective contact angle and the heat transfer coefficient as a function of the relevant dimensionsless parameters as well as physical explanations for the observed behavior. The data will be used

  18. Caffeine as an indicator of estrogenic activity in source water.

    PubMed

    Montagner, C C; Umbuzeiro, G A; Pasquini, C; Jardim, W F

    2014-08-01

    Caffeine has already been used as an indicator of anthropogenic impacts, especially the ones related to the disposal of sewage in water bodies. In this work, the presence of caffeine has been correlated with the estrogenic activity of water samples measured using the BLYES assay. After testing 96 surface water samples, it was concluded that caffeine can be used to prioritize samples to be tested for estrogenic activity in water quality programs evaluating emerging contaminants with endocrine disruptor activity.

  19. Surface Deformation by Thermo-capillary Convection -Sounding Rocket COMPERE Experiment SOURCE

    NASA Astrophysics Data System (ADS)

    Fuhrmann, Eckart; Dreyer, Michael E.

    The sounding rocket COMPERE experiment SOURCE was successfully flown on MASER 11, launched in Kiruna (ESRANGE), May 15th, 2008. SOURCE has been intended to partly ful-fill the scientific objectives of the European Space Agency (ESA) Microgravity Applications Program (MAP) project AO-2004-111 (Convective boiling and condensation). Three parties of principle investigators have been involved to design the experiment set-up: ZARM for thermo-capillary flows, IMFT (Toulouse, France) for boiling studies, EADS Astrium (Bremen, Ger-many) for depressurization. The scientific aims are to study the effect of wall heat flux on the contact line of the free liquid surface and to obtain a correlation for a convective heat transfer coefficient. The experiment has been conducted along a predefined time line. A preheating sequence at ground was the first operation to achieve a well defined temperature evolution within the test cell and its environment inside the rocket. Nearly one minute after launch, the pressurized test cell was filled with the test liquid HFE-7000 until a certain fill level was reached. Then the free surface could be observed for 120 s without distortion. Afterwards, the first depressurization was started to induce subcooled boiling, the second one to start saturated boiling. The data from the flight consists of video images and temperature measurements in the liquid, the solid, and the gaseous phase. Data analysis provides the surface shape versus time and the corresponding apparent contact angle. Computational analysis provides information for the determination of the heat transfer coefficient in a compensated gravity environment where a flow is caused by the temperature difference between the hot wall and the cold liquid. Correlations for the effective contact angle and the heat transfer coefficient shall be delivered as a function of the relevant dimensionsless parameters. The data will be used for benchmarking of commercial CFD codes and the tank design

  20. Characterization of DNAPL Source Zone Architecture and Associated Plume Response in 2-D Aquifer Cell Experiments

    NASA Astrophysics Data System (ADS)

    Granbery, E. K.; Cápiro, N.; Christ, J.; Pennell, K.

    2008-12-01

    A series of two-dimensional (2-D) aquifer cell experiments was conducted to evaluate the effects of DNAPL source zone architecture on down-gradient plume and flux-averaged effluent concentrations. The aquifer cells (1.0 m length x 48 cm height x 1.4 cm internal thickness) were packed with different size fractions of quartz sands and low permeability lens configurations to achieve a range of source zone saturation distributions. A mixed DNAPL, consisting of 1:1 trichloroethene (TCE) and tetrachloroethene (PCE), was released into the source zone region of the aquifer cell at a flow rate of 2.0 ml/min and allowed to redistribute for a period of 48 hours. The DNAPL saturation distribution was quantified using a light transmission system and characterized by the ganglia-to-pool ratio (GTP, 0 to infinity) and ganglia fraction (GF, 0-100%), where saturations less than 0.13 represent discrete ganglia and saturations equal to or greater than 0.13 are considered to represent "pools". Effluent dissolved-phase TCE and PCE concentrations were monitored continuously, while down-gradient plume concentrations were collected periodically from 25 side-port samples. To accelerate mass removal, the aquifer cells were flushed with 1.5 pore volumes of 4% Tween 80, a nonionic, food-grade surfactant that has been shown to facilitate microbial reductive dechlorination. Experimental data are used to evaluate interrelationships between the initial source zone architecture, mass removal, reductions in mass flux, and plume evolution.

  1. The MODE family of on-orbit experiments: The Middeck Active Control Experiment (MACE)

    NASA Technical Reports Server (NTRS)

    Crawley, Edward F.; Miller, David W.; Deluis, Javier; Waldman, Mel; Bicos, Andy

    1990-01-01

    A flight experiment entitled the Middeck Active Control Experiment (MACE), proposed by the Space Engineering Research Center (SERC) at the Massachusetts Institute of Technology, is described. This is the second in a family of flight experiments being developed at MIT. The first is the Middeck 0-Gravity Dynamics Experiment (MODE) which investigates the nonlinear behavior of contained fluids and truss structures in zero gravity. The objective of the MACE program is to investigate and validate the modeling of the dynamics of an actively controlled flexible, articulating, multibody platform free floating in zero gravity. A rationale and experimental approach for the program are presented. The rationale shows that on-orbit testing, coupled with ground testing and a strong analytical program, is necessary in order to fully understand both how flexibility of the platform affects the pointing problem, as well as how gravity perturbs this structural flexibility causing deviations between 1- and 0-gravity behavior. The experimental approach captures the essential physics of multibody platforms, by identifying the appropriate attributes, tests, and performance metrics of the test article and defines the tests required to successfully validate the analytical framework.

  2. The MODE family of on-orbit experiments: The Middeck Active Control Experiment (MACE)

    NASA Astrophysics Data System (ADS)

    Crawley, Edward F.; Miller, David W.; Deluis, Javier; Waldman, Mel; Bicos, Andy

    1990-12-01

    A flight experiment entitled the Middeck Active Control Experiment (MACE), proposed by the Space Engineering Research Center (SERC) at the Massachusetts Institute of Technology, is described. This is the second in a family of flight experiments being developed at MIT. The first is the Middeck 0-Gravity Dynamics Experiment (MODE) which investigates the nonlinear behavior of contained fluids and truss structures in zero gravity. The objective of the MACE program is to investigate and validate the modeling of the dynamics of an actively controlled flexible, articulating, multibody platform free floating in zero gravity. A rationale and experimental approach for the program are presented. The rationale shows that on-orbit testing, coupled with ground testing and a strong analytical program, is necessary in order to fully understand both how flexibility of the platform affects the pointing problem, as well as how gravity perturbs this structural flexibility causing deviations between 1- and 0-gravity behavior. The experimental approach captures the essential physics of multibody platforms, by identifying the appropriate attributes, tests, and performance metrics of the test article and defines the tests required to successfully validate the analytical framework.

  3. EPA (Environmental Protection Agency) activities related to sources of ground-water contamination

    SciTech Connect

    Black-Coleman, W.

    1987-02-01

    The report contains a listing of EPA programs and activities, as of October 1986, that address 33 sources of potential ground-water contamination. The information on each activity is presented in a matrix format that is organized by type of contamination source. The following information is presented for each program and activity listed: title, lead office, contact person, type of activity (study, regulation, guidance, strategy, etc.) status, and a summary of the activity. The 33 sources of ground-water contamination are discussed in the 1984 EPA Office of Technology report: Protecting the Nations Ground Water from Contamination.

  4. [Health promotion through physical activity: territorial models and experiences].

    PubMed

    Romano-Spica, V; Parlato, A; Palumbo, D; Lorenzo, E; Frangella, C; Montuori, E; Anastasi, D; Visciano, A; Liguori, G

    2008-01-01

    Scientific evidences support the preventive role of physical activity in relation to different multifactorial pathologies. Health's promotion through the spreading of lifestyles that encourage movement, does not represent just an action in contrast with "sedentary life" risk-factor, but also a priority for "quality" of life, with relevant economical and social benefits. WHO indicates physical activity as one of the priorities for an effective prevention. Besides, the EU supports the realization and the diffusion of some prevention-programs. Main pilot experiences developed in Italy and other countries are summarized. Attention is focused on the role of the competences and structures involved in an integrated approach based on availability of medical support, social services and local structures, considering recent developments in health prevention and promotion. In Italy and Europe, new opportunities to implement health promotion through physical activity are offered by the development of higher education in movement and sport sciences.

  5. Modulated spectral activity (MSA) - Implications for planetary radio sources

    NASA Astrophysics Data System (ADS)

    Thieman, James R.; Alexander, Joseph K.; Staelin, David H.

    The properties of the Jovian and Saturnian MSA, modulation patterns within the normally diffuse nonthermal radio emission that are characterized by distinctive banded structures of enhanced intensity fluctuations in frequency over time scales of minutes to tens of minutes, are discussed. Although Jovian and Saturnian MSA are both normally observed in the 0.2-1.3-MHz frequency range, similar pattern have been noted in Jovian decametric emission above 30 MHz. The MSA properties are used to constrain the possible source mechanism.

  6. Modulated spectral activity (MSA) - Implications for planetary radio sources

    NASA Technical Reports Server (NTRS)

    Thieman, James R.; Alexander, Joseph K.; Staelin, David H.

    1988-01-01

    The properties of the Jovian and Saturnian MSA, modulation patterns within the normally diffuse nonthermal radio emission that are characterized by distinctive banded structures of enhanced intensity fluctuations in frequency over time scales of minutes to tens of minutes, are discussed. Although Jovian and Saturnian MSA are both normally observed in the 0.2-1.3-MHz frequency range, similar pattern have been noted in Jovian decametric emission above 30 MHz. The MSA properties are used to constrain the possible source mechanism.

  7. Simulations as Active Assessment?: Typologizing by Purpose and Source

    ERIC Educational Resources Information Center

    Kollars, Nina A.; Rosen, Amanda M.

    2013-01-01

    Assessment through simulation is something that political science pedagogy has yet to explore in a robust manner. This article advances analysis of social science simulation and assessment by laying out a typology of active-learning activities that isolates and examines their potential for assessment. In short, we argue that there are essentially…

  8. Artifacts as Sources for Problem-Posing Activities

    ERIC Educational Resources Information Center

    Bonotto, Cinzia

    2013-01-01

    The problem-posing process represents one of the forms of authentic mathematical inquiry which, if suitably implemented in classroom activities, could move well beyond the limitations of word problems, at least as they are typically utilized. The two exploratory studies presented sought to investigate the impact of "problem-posing" activities when…

  9. Excitation of whistler waves from inductive sources: Experiment and computer modeling

    NASA Astrophysics Data System (ADS)

    Rousculp, Christopher Lee

    1997-09-01

    Low frequency whistler waves are studied in the context of electron-magnetohydro-dynamics (EMHD) with experiments and computer modeling. Experiments show that an oblique whistler wave packet is excited from a single current pulse applied to a magnetic loop antenna. The magnetic field is mapped in three dimensions and time. The angle of dominant radiation is determined by the antenna dimensions, not by the constraints of the resonance cone. Topological properties of the inductive and space charge electric fields and space charge density confirm EMHD physics. Transverse currents are dominated by Hall currents, while no net current flows in the parallel direction. Electron-ion collisions damp both the energy and the helicity of the wave packet. Landau damping is negligible. The radiation resistance of the loop is a few tenths of an Ohm for the observed frequency range. The loop injects zero net helicity. Rather, oppositely traveling wave packets carry equal amounts of opposite signed helicity. Modeling confirms the experimental results for a single turn antenna. Linked or knotted antennas are shown to be directional whistler sources that inject helicity into an EMHD plasma. Electron inertial effects are included in the modeling and an antenna radiating predominantly at Gendrin's constant velocity mode is designed. Experiments currently underway show preliminary results that support the conclusions of the modeling.

  10. Rotatable spin-polarized electron source for inverse-photoemission experiments

    SciTech Connect

    Stolwijk, S. D. Wortelen, H.; Schmidt, A. B.; Donath, M.

    2014-01-15

    We present a ROtatable Spin-polarized Electron source (ROSE) for the use in spin- and angle-resolved inverse-photoemission (SR-IPE) experiments. A key feature of the ROSE is a variable direction of the transversal electron beam polarization. As a result, the inverse-photoemission experiment becomes sensitive to two orthogonal in-plane polarization directions, and, for nonnormal electron incidence, to the out-of-plane polarization component. We characterize the ROSE and test its performance on the basis of SR-IPE experiments. Measurements on magnetized Ni films on W(110) serve as a reference to demonstrate the variable spin sensitivity. Moreover, investigations of the unoccupied spin-dependent surface electronic structure of Tl/Si(111) highlight the capability to analyze complex phenomena like spin rotations in momentum space. Essentially, the ROSE opens the way to further studies on complex spin-dependent effects in the field of surface magnetism and spin-orbit interaction at surfaces.

  11. Sources of tropical Atlantic coupled model biases derived from initialised hindcasts and partially coupled sensitivity experiments

    NASA Astrophysics Data System (ADS)

    Deppenmeier, Anna-Lena; Hazeleger, Wilco; Haarsma, Rein; Prodhomme, Chloé; Exarchou, Eleftheria; Doblas-Reyes, Francisco J.

    2016-04-01

    State-of-the-art coupled general circulation models (CGCMs) still fail to simulate the mean state and variability of the tropical Atlantic (TA) climate correctly. We investigate the importance of air-sea interaction at different regions in the TA by means of performing partially coupled sensitivity experiments with the state-of-the-art CGCM EC-Earth3.1. All simulations are intialised from the observed climate state. By studying the initial drift in sensitivity experiments we obtain insight into the tropical dynamics and sources of model bias. We test the influence of realistic wind stress forcing over different regions of the TA on the development of SST as well as other oceanic biases. A series of hindcasts fully initialised in May and run until the end of August are performed with prescribed ERA-Interim zonal and meridional wind stresses over three different regions: firstly, we force the entire TA from 15N - 30S. Secondly, we force the equatorial band only between 5N - 5S, and finally we force the coastal area of the Angola Benguela upwelling region between 0W and the coast and between 5S - 30N. Our setup only affects the oceanic forcing and leaves the atmosphere free to adapt, such that we can identify the air-sea interaction processes in the different regions and their effect on the SST bias in the fully coupled system. The differences between forcing the entire TA and the equatorial region only are very small, which hints to the great importance of the relatively narrow equatorial region. The coastal upwelling area does not strongly affect the equatorial region in our model. We identify the equatorial band as most susceptible to errors in the wind stress forcing and, due to the strong atmosphere-ocean coupling, as source of the main biases in our model. The partially coupled experiments with initialised seasonal hindcasts appear to be a powerful tool to identify the sources of model biases and to identify relevant air-sea interaction processes in the TA.

  12. Predicting Activation of Experiments Inside the Annular Core Research Reactor

    SciTech Connect

    Greenberg, Joseph Isaac

    2015-11-01

    The objective of this thesis is to create a program to quickly estimate the radioactivity and decay of experiments conducted inside of the Annular Core Research Reactor at Sandia National Laboratories and eliminate the need for users to write code. This is achieved by model the neutron fluxes in the reactor’s central cavity where experiments are conducted for 4 different neutron spectra using MCNP. The desired neutron spectrum, experiment material composition, and reactor power level are then input into CINDER2008 burnup code to obtain activation and decay information for every isotope generated. DREAD creates all of the files required for CINDER2008 through user selected inputs in a graphical user interface and executes the program for the user and displays the resulting estimation for dose rate at various distances. The DREAD program was validated by weighing and measuring various experiments in the different spectra and then collecting dose rate information after they were irradiated and comparing it to the dose rates that DREAD predicted. The program provides results with an average of 17% higher estimates than the actual values and takes seconds to execute.

  13. Individuals with low working memory spans show greater interference from irrelevant information because of poor source monitoring, not greater activation.

    PubMed

    Lilienthal, Lindsey; Rose, Nathan S; Tamez, Elaine; Myerson, Joel; Hale, Sandra

    2015-04-01

    Although individuals with high and low working memory (WM) span appear to differ in the extent to which irrelevant information interferes with their performance on WM tasks, the locus of this interference is not clear. The present study investigated whether, when performing a WM task, high- and low-span individuals differ in the activation of formerly relevant, but now irrelevant items, and/or in their ability to correctly identify such irrelevant items. This was done in two experiments, both of which used modified complex WM span tasks. In Experiment 1, the span task included an embedded lexical decision task designed to obtain an implicit measure of the activation of both currently and formerly relevant items. In Experiment 2, the span task included an embedded recognition judgment task designed to obtain an explicit measure of both item and source recognition ability. The results of these experiments indicate that low-span individuals do not hold irrelevant information in a more active state in memory than high-span individuals, but rather that low-span individuals are significantly poorer at identifying such information as irrelevant at the time of retrieval. These results suggest that differences in the ability to monitor the source of information, rather than differences in the activation of irrelevant information, are the more important determinant of performance on WM tasks.

  14. ECH by FEL and gyrotron sources on the Microwave Tokamak Experiment (MTX) tokamak

    SciTech Connect

    Stallard, B.W.; Turner, W.C.; Allen, S.L.; Byers, J.A.; Felker, B.; Fenstermacher, M.E.; Ferguson, S.W.; Hooper, E.G.; Thomassen, K.I.; Throop, A.L. ); Makowski, M.A. )

    1990-08-09

    The Microwave Tokamak Experiment (MTX) at LLNL is studying the physics of intense pulse ECH is a high-density tokamak plasma using a microwave FEL. Related technology development includes the FEL, a windowless quasi-optical transmission system, and other microwave components. Initial plasma experiments have been carried out at 140 GHz with single rf pulses generated using the ETA-II accelerator and the ELF wiggler. Peak power levels up to 0.2 GW and pulse durations up to 10 ns were achieved for injection into the plasma using as untapered wiggler. FEL pulses were transmitted over 33 m from the FEL to MTX using six mirrors mounted in a 50-cm-diam evacuated pipe. Measurements of the microwave beam and transmission through the plasma were carried out. For future rapid pulse experiments at high average power (4 GW peak power, 5kHz pulse rate, and {bar P} > 0.5 MW) using the IMP wiggler with tapered magnetic field, a gyrotron (140 GHz, 400 kW cw or up to 1 MW short pulse) is being installed to drive the FEL input or to directly heat the tokamak plasma at full gyrotron power. Quasi-optic techniques will be used to couple the gyrotron power. For direct plasma heating, the gyrotron will couple into the existing mirror transport system. Using both sources of rf generation, experiments are planned to investigate intense pulse absorption and tokamak physics, such as the ECH of a pellet-fueled plasma and plasma control using localized heating. 12 refs., 9 figs.

  15. ECH by FEL and gyrotron sources on the Microwave Tokamak Experiment (MTX) tokamak

    NASA Astrophysics Data System (ADS)

    Stallard, B. W.; Turner, W. C.; Allen, S. L.; Byers, J. A.; Felker, B.; Fenstermacher, M. E.; Ferguson, S. W.; Hooper, E. G.; Thomassen, K. I.; Throop, A. L.

    1990-08-01

    The Microwave Tokamak Experiment (MTX) at LLNL is studying the physics of intense pulse ECH is a high-density tokamak plasma using a microwave FEL. Related technology development includes the FEL, a windowless quasi-optical transmission system, and other microwave components. Initial plasma experiments have been carried out at 140 GHz with single RF pulses generated using the ETA-2 accelerator and the ELF wiggler. Peak power levels up to 0.2 GW and pulse durations up to 10 ns were achieved for injection into the plasma using as untapered wiggler. FEL pulses were transmitted over 33 m from the FEL to MTX using six mirrors mounted in a 50 cm diam evacuated pipe. Measurements of the microwave beam and transmission through the plasma were carried out. For future rapid pulse experiments at high average power (4 GW peak power, 5 kHz pulse rate, and bar P is greater than 0.5 MW) using the IMP wiggler with tapered magnetic field, a gyrotron (140 GHz, 400 kW CW or up to 1 MW short pulse) is being installed to drive the FEL input or to directly heat the tokamak plasma at full gyrotron power. Quasi-optic techniques will be used to couple the gyrotron power. For direct plasma heating, the gyrotron will couple into the existing mirror transport system. Using both sources of RF generation, experiments are planned to investigate intense pulse absorption and tokamak physics, such as the ECH of a pellet-fueled plasma and plasma control using localized heating.

  16. Seeing mathematics: perceptual experience and brain activity in acquired synesthesia.

    PubMed

    Brogaard, Berit; Vanni, Simo; Silvanto, Juha

    2013-01-01

    We studied the patient JP who has exceptional abilities to draw complex geometrical images by hand and a form of acquired synesthesia for mathematical formulas and objects, which he perceives as geometrical figures. JP sees all smooth curvatures as discrete lines, similarly regardless of scale. We carried out two preliminary investigations to establish the perceptual nature of synesthetic experience and to investigate the neural basis of this phenomenon. In a functional magnetic resonance imaging (fMRI) study, image-inducing formulas produced larger fMRI responses than non-image inducing formulas in the left temporal, parietal and frontal lobes. Thus our main finding is that the activation associated with his experience of complex geometrical images emerging from mathematical formulas is restricted to the left hemisphere.

  17. X-RAY ACTIVE MATRIX PIXEL SENSORS BASEDON J-FET TECHNOLOGY DEVELOPED FOR THE LINAC COHERENT LIGHT SOURCE.

    SciTech Connect

    CARINI,G.A.; CHEN, W.; LI, Z.; REHAK, P.; SIDDONS, D.P.

    2007-10-29

    An X-ray Active Matrix Pixel Sensor (XAMPS) is being developed for recording data for the X-ray Pump Probe experiment at the Linac Coherent Light Source (LCLS). Special attention has to be paid to some technological challenges that this design presents. New processes were developed and refined to address problems encountered during previous productions of XAMPS. The development of these critical steps and corresponding tests results are reported here.

  18. Plasma Jet Motion Across the Geomagnetic Field in the ``North Star'' Active Geophysical Experiment

    NASA Astrophysics Data System (ADS)

    Gavrilov, B. G.; Zetzer, J. I.; Podgorny, I. M.; Sobyanin, D. B.; Meng, C.-I.; Erlandson, R. E.; Stenbaek-Nielsen, H. C.; Pfaff, R. F.; Lynch, K. A.

    2003-01-01

    The active geophysical rocket experiment ``North Star'' was carried out in the auroral ionosphere on January 22, 1999, at the Poker Flat Research Range (Alaska, USA) using the American research rocket Black Brant XII with explosive plasma generators on board. Separable modules with scientific equipment were located at distances of from 170 to 1595 m from the plasma source. The experiment continued the series of the Russian-American joint experiments started by the ``Fluxus'' experiment in 1997. Two injections of aluminum plasma across the magnetic field were conducted in the ``North Star'' experiment. They were different, since in the first injection a neutral gas cloud was formed in order to increase the plasma ionization due to the interaction of neutrals of the jet and cloud. The first and second injections were conducted at heights of 360 and 280 km, respectively. The measurements have shown that the charged particle density was two orders of magnitude higher in the experiment with the gas release. The magnetic field in the first injection was completely expelled by the dense plasma of the jet. The displacement of the magnetic field in the second injection was negligible. The plasma jet velocity in both injections decreased gradually due to its interaction with the geomagnetic field. One of the most interesting results of the experiment was the conservation of high plasma density during the propagation of the divergent jet to considerable distances. This fact can be explained by the action of the critical ionization velocity mechanism.

  19. EXPERIENCE WITH COLLABORATIVE DEVELOPMENT FOR THE SPALLATION NEUTRON SOURCE FROM A PARTNER LAB PERSPECTIVE.

    SciTech Connect

    HOFF, L.T.

    2005-10-10

    Collaborative development and operation of large physics experiments is fairly common. Less common is the collaborative development or operation of accelerators. A current example of the latter is the Spallation Neutron Source (SNS). The SNS project was conceived as a collaborative effort between six DOE facilities. In the SNS case, the control system was also developed collaboratively. The SNS project has now moved beyond the collaborative development phase and into the phase where Oak Ridge National Lab (ORNL) is integrating contributions from collaborating ''partner labs'' and is beginning accelerator operations. In this paper, the author reflects on the benefits and drawbacks of the collaborative development of an accelerator control system as implemented for the SNS project from the perspective of a partner lab.

  20. Demonstration of simultaneous experiments using thin crystal multiplexing at the Linac Coherent Light Source.

    PubMed

    Feng, Y; Alonso-Mori, R; Barends, T R M; Blank, V D; Botha, S; Chollet, M; Damiani, D S; Doak, R B; Glownia, J M; Koglin, J M; Lemke, H T; Messerschmidt, M; Nass, K; Nelson, S; Schlichting, I; Shoeman, R L; Shvyd'ko, Yu V; Sikorski, M; Song, S; Stoupin, S; Terentyev, S; Williams, G J; Zhu, D; Robert, A; Boutet, S

    2015-05-01

    Multiplexing of the Linac Coherent Light Source beam was demonstrated for hard X-rays by spectral division using a near-perfect diamond thin-crystal monochromator operating in the Bragg geometry. The wavefront and coherence properties of both the reflected and transmitted beams were well preserved, thus allowing simultaneous measurements at two separate instruments. In this report, the structure determination of a prototypical protein was performed using serial femtosecond crystallography simultaneously with a femtosecond time-resolved XANES studies of photoexcited spin transition dynamics in an iron spin-crossover system. The results of both experiments using the multiplexed beams are similar to those obtained separately, using a dedicated beam, with no significant differences in quality.

  1. Construction of a Visible Diode Laser Source for Free Radical Photochemistry and Spectroscopy Experiments

    NASA Technical Reports Server (NTRS)

    Newman, Bronjelyn; Halpern, Joshua B.

    1997-01-01

    Tunable diode lasers are reliable sources of narrow-band light and comparatively cheap. Optical feedback simplifies frequency tuning of the laser diodes. We are building an inexpensive diode laser system incorporating optical feedback from a diffraction grating. The external optical cavity can be used with lasers that emit between 2 and 100 mW, and will also work if they are pulsed, although this will significantly degrade the bandwidth. The diode laser output power and bandwidth are comparable to CW dye lasers used in kinetics and dynamics experiments. However, their cost and maintenance will be much less as will alignment time. We intend to use the diode lasers to investigate CN and C2 kinetics as well as to study dissociation dynamics of atmospherically important molecules.

  2. Constraining the source of chlorinated hydrocarbons detected on Mars with the SAM experiment onboard Curiosity

    NASA Astrophysics Data System (ADS)

    Belmahdi, I.; Buch, A.; Szopa, C.; Freissinet, C.; Glavin, D.; François, P.; Coll, P.; Eigenbrode, J.; Navarro-Gonzalez, A. R.; Dequaire, T.; Millan, M.; Tenturier, S.; Bonnet, J. Y.; Mahaffy, P.; Cabane, M.

    2015-10-01

    Organic molecules have been at the origin of the prebiotic chemistry that led to the emergence of life on Earth. Therefore, they are one of the key ingredients required to assess the habitability in environments of the solar system. On Mars, no endogenous organics were found until very recently (1) whereas they are expected to be present in the soil, either because they were kept safe in rocks since the early history of the planet, or because they are still brought to the Mars surface by exogenous sources. Because of their importance for astrobiology, efforts are still ongoing to search for these species in the Gale crater by the Curiosity rover, and especially the SAM experiment on its board.

  3. Cancer-Related Pain and Pain Management: Sources, Prevalence, and the Experiences of Children and Parents.

    PubMed

    Twycross, Alison; Parker, Roslyn; Williams, Anna; Gibson, Faith

    2015-01-01

    Advances in treatment mean children are increasingly cared for by their parents at home, leading to a shift in responsibility from health care professionals to parents. Little is known about parents' pain management experiences and the etiology of pain experienced by children with cancer especially when at home. A rapid review of the literature was undertaken investigating children's cancer-related pain, with emphasis on the management of pain outside the health care setting. Electronic databases were searched and a quality assessment was conducted. Forty-two articles were included. Despite advances in pain management techniques, children with cancer regularly cite pain as the most prevalent symptom throughout the cancer trajectory. The source of pain is usually treatment side effects or painful procedures. Parents find dealing with their child's pain distressing and demanding and may hold misconceptions about pain management. Findings indicate a need for more robust research into parental pain management leading to the development of effective pain management resources for parents.

  4. Site Characterization of the Source Physics Experiment Phase II Location Using Seismic Reflection Data

    SciTech Connect

    Sexton, Emily; Snelson, Catherine M; Chipman, Veraun D; Emer, Dudley; White, Bob; Emmit, Ryan; Wright, Al; Drellack, Sigmund; Huckins-Gang, Heather; Mercadante, Jennifer; Floyd, Michael; McGowin, Chris; Cothrun, Chris; Bonal, Nedra

    2013-12-05

    An objective of the Source Physics Experiment (SPE) is to identify low-yield nuclear explosions from a regional distance. Low-yield nuclear explosions can often be difficult to discriminate among the clutter of natural and man-made explosive events (e.g., earthquakes and mine blasts). The SPE is broken into three phases. Phase I has provided the first of the physics-based data to test the empirical models that have been used to discriminate nuclear events. The Phase I series of tests were placed within a highly fractured granite body. The evolution of the project has led to development of Phase II, to be placed within the opposite end member of geology, an alluvium environment, thereby increasing the database of waveforms to build upon in the discrimination models. Both the granite and alluvium sites have hosted nearby nuclear tests, which provide comparisons for the chemical test data. Phase III of the SPE is yet to be determined.

  5. Dr. Fishman Reviewing Data From the Burst and Transient Source Experiment (BATSE)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    In this photograph, Dr. Gerald Fishman of the Marshall Space Flight Center (MSFC), a principal investigator of the Compton Gamma-Ray Observatory's (GRO's) instrument, the Burst and Transient Source Experiment (BATSE), and Dr. Chryssa Kouveliotou of Universities Space Research Associates review data from the BATSE. For nearly 9 years, GRO's Burst and Transient Source Experiment (BATSE), designed and built by the Marshall Space Flight Center, kept a blinking watch on the universe to alert scientist to the invisible, mysterious gamma-ray bursts. By studying gamma-rays from objects like black holes, pulsars, quasars, neutron stars, and other exotic objects, scientists could discover clues to the birth, evolution, and death of stars, galaxies, and the universe. The gamma-ray instrument was one of four major science instruments aboard the Compton. It consisted of eight detectors, or modules, located at each corner of the rectangular satellite to simultaneously scan the entire universe for bursts of gamma-rays ranging in duration from fractions of a second to minutes. Because gamma-rays are so powerful, they pass through conventional telescope mirrors. Instead of a mirror, the heart of each BATSE module was a large, flat, transparent crystal that generated a tiny flash of light when struck by a gamma-ray. With an impressive list of discoveries and diverse accomplishments, BATSE could claim to have rewritten astronomy textbooks. Launched aboard the Space Shuttle Orbiter Atlantis during the STS-35 mission in April 1991, the GRO reentered the Earth's atmosphere and ended its successful 9-year mission in June 2000.

  6. Active experiments in the ionosphere and geomagnetic field variations

    NASA Astrophysics Data System (ADS)

    Sivokon, V. P.; Cherneva, N. V.; Khomutov, S. Y.; Serovetnikov, A. S.

    2014-11-01

    Variations of ionospheric-magnetospheric relation energy, as one of the possible outer climatology factors, may be traced on the basis of analysis of natural geophysical phenomena such as ionosphere artificial radio radiation and magnetic storms. Experiments on active impact on the ionosphere have been carried out for quite a long time in Russia as well. The most modern heating stand is located in Alaska; it has been used within the HAARP Program. The possibility of this stand to affect geophysical fields, in particular, the geomagnetic field is of interest.

  7. Pt +-mediated activation of methane: theory and experiment

    NASA Astrophysics Data System (ADS)

    Heinemann, Christoph; Wesendrup, Ralf; Schwarz, Helmut

    1995-06-01

    A combined theoretical and experimental study on the Pt +-mediated activation of methane is presented. Dehydrogenation of CH 4 by thermalized Pt + cations (Pt + + CH 4 ← PtCH 2+ + H 2) proceeds along a doublet ground state potential energy surface and is found to be reversible under the conditions of Fourier transform ion-cyclotron resonance mass spectrometry. The recently reported oxidation of the cationic platinum carbene PtCH 2+ by O 2 produces electronically excited Pt + cations, which are detected in the 4F9/2 state by means of charge-transfer bracketing experiments.

  8. Study of the Helicon Source Operation in the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) Experiment

    NASA Technical Reports Server (NTRS)

    Molvig, Kim; Batishchev, Oleg

    2003-01-01

    During this research period the following models of the VASIMR helicon discharge have been further developed and applied to analyze the on-going VX- 10 ASPL experiment: A) 1D semi-analytical model for a mixed-collisional propellant flow B) OD power and balance model for the whole helicon discharge In this particular research period we have concentrated on the MW-level performance of the VASIMR helicon source. Favorable high-power scaling and reduced ionization costs were obtained, and presented at the VASIMR NASA review in the Fall '02. This Grant is continuation of the previous NAG9-1224 award. The research results are summarized in 14 publications; they were presented as 20+ talks at the major International Conferences and scientific seminars at the leading Academic and Research Institutions. The reported results allowed helicon discharge characterization, understanding of the several experimental observations, and helped to make predictions and propose structural modifications for the advanced VASIMR helicon source operation.

  9. A Laser-Cooled Ion Source to Sympathetically Cool Positrons in the ALPHA Experiment

    NASA Astrophysics Data System (ADS)

    Sameed, Muhammed; Maxwell, Daniel; Madsen, Niels

    2016-10-01

    The ALPHA experiment at CERN studies the properties of antimatter by making precision measurements on antihydrogen. Antihydrogen atoms are produced by mixing a cloud of cold antiprotons with a dense positron plasma inside a magnetic trap. The formation of antihydrogen, of which only the coldest atoms remain trapped, depends principally on the kinetic energy of the constituent plasmas. Presently, the trapping rate is approximately two atoms in a seven minute cycle. During mixing, the antiprotons thermalize in the positron plasma prior to antihydrogen production. Colder positron temperatures would therefore result in an increased fraction of trapped antihydrogen atoms in the ALPHA mixing trap. At present, the positrons used for antihydrogen production in ALPHA reach energies of about 50 K. Much colder positron plasmas may be achieved by sympathetically cooling the positrons using laser-cooled beryllium ions. Preliminary results in the development of a low flux and low energy beryllium ion source using a pulsed ablation laser are presented. Precision ablation techniques coupled with laser-cooling can subsequently be used to effectively cool positrons. A provisional design of an ablation source is also presented for installation in the ALPHA apparatus in 2017. The authors would like to thank EPSRC for supporting this research.

  10. Experiments with biased side electrodes in electron cyclotron resonance ion sources.

    PubMed

    Drentje, A G; Kitagawa, A; Uchida, T; Rácz, R; Biri, S

    2014-02-01

    The output of highly charged ions from an electron cyclotron resonance ion source (ECRIS) consists of ionic losses from a highly confined plasma. Therefore, an increase of the output of the ions of interest always is a compromise between an increase in the confinement and an increase of the losses. One route towards a solution consists of attacking the losses in directions - i.e., radial directions - that do not contribute to the required output. This was demonstrated in an experiment (using the Kei ECRIS at NIRS, Japan) where radial losses were electrostatically reduced by positively biasing one set of six "side" electrodes surrounding the plasma in side-ward directions attached (insulated) to the cylindrical wall of the plasma chamber. Recently new studies were performed in two laboratories using two essentially different ion sources. At the BioNano ECRIS (Toyo University, Japan) various sets of electrodes were used; each of the electrodes could be biased individually. At the Atomki ECRIS (Hungary), one movable, off-axis side electrode was applied in technically two versions. The measurements show indeed a decrease of ionic losses but different effectivities as compared to the biased disk.

  11. Experiments with biased side electrodes in electron cyclotron resonance ion sources

    SciTech Connect

    Drentje, A. G. Kitagawa, A.; Uchida, T.; Rácz, R.; Biri, S.

    2014-02-15

    The output of highly charged ions from an electron cyclotron resonance ion source (ECRIS) consists of ionic losses from a highly confined plasma. Therefore, an increase of the output of the ions of interest always is a compromise between an increase in the confinement and an increase of the losses. One route towards a solution consists of attacking the losses in directions – i.e., radial directions – that do not contribute to the required output. This was demonstrated in an experiment (using the Kei ECRIS at NIRS, Japan) where radial losses were electrostatically reduced by positively biasing one set of six “side” electrodes surrounding the plasma in side-ward directions attached (insulated) to the cylindrical wall of the plasma chamber. Recently new studies were performed in two laboratories using two essentially different ion sources. At the BioNano ECRIS (Toyo University, Japan) various sets of electrodes were used; each of the electrodes could be biased individually. At the Atomki ECRIS (Hungary), one movable, off-axis side electrode was applied in technically two versions. The measurements show indeed a decrease of ionic losses but different effectivities as compared to the biased disk.

  12. Advanced light source vacuum policy and vacuum guidelines for beamlines and experiment endstations

    SciTech Connect

    Hussain, Z.

    1995-08-01

    The purpose of this document is to: (1) Explain the ALS vacuum policy and specifications for beamlines and experiment endstations. (2) Provide guidelines related to ALS vacuum policy to assist in designing beamlines which are in accordance with ALS vacuum policy. This document supersedes LSBL-116. The Advanced Light Source is a third generation synchrotron radiation source whose beam lifetime depends on the quality of the vacuum in the storage ring and the connecting beamlines. The storage ring and most of the beamlines share a common vacuum and are operated under ultra-high-vacuum (UHV) conditions. All endstations and beamline equipment must be operated so as to avoid contamination of beamline components, and must include proper safeguards to protect the storage ring vacuum from an accidental break in the beamline or endstation vacuum systems. The primary gas load during operation is due to thermal desorption and electron/photon induced desorption of contaminants from the interior of the vacuum vessel and its components. The desorption rates are considerably higher for hydrocarbon contamination, thus considerable emphasis is placed on eliminating these sources of contaminants. All vacuum components in a beamline and endstation must meet the ALS vacuum specifications. The vacuum design of both beamlines and endstations must be approved by the ALS Beamline Review Committee (BRC) before vacuum connections to the storage ring are made. The vacuum design is first checked during the Beamline Design Review (BDR) held before construction of the beamline equipment begins. Any deviation from the ALS vacuum specifications must be approved by the BRC prior to installation of the equipment on the ALS floor. Any modification that is incorporated into a vacuum assembly without the written approval of the BRC is done at the user`s risk and may lead to rejection of the whole assembly.

  13. Papaya seed represents a rich source of biologically active isothiocyanate.

    PubMed

    Nakamura, Yoshimasa; Yoshimoto, Motoko; Murata, Yoshiyuki; Shimoishi, Yasuaki; Asai, Yumi; Park, Eun Young; Sato, Kenji; Nakamura, Yasushi

    2007-05-30

    In the present study, papaya (Carica papaya) seed and edible pulp were carefully separated and then the contents of benzyl isothiocyanate and the corresponding glucosinolate (benzyl glucosinolate, glucotropaeolin) quantified in each part. The papaya seed with myrosinase inactivation contained >1 mmol of benzyl glucosinolate in 100 g of fresh seed. This content is equivalent to that of Karami daikon (the hottest Japanese white radish) or that of cress. The papaya seed extract also showed a very high activity of myrosinase and, without myrosinase inactivation, produced 460 micromol of benzyl isothiocyanate in 100 g of seed. In contrast, papaya pulp contained an undetectable amount of benzyl glucosinolate and showed no significant myrosinase activity. The n-hexane extract of the papaya seed homogenate was highly effective in inhibiting superoxide generation and apoptosis induction in HL-60 cells, the activities of which are comparable to those of authentic benzyl isothiocyanate.

  14. Geology of the Tremor Source: What are the Active Processes?

    NASA Astrophysics Data System (ADS)

    Fagereng, A.; Hartnady, M. I. H.; Diener, J. F. A.

    2015-12-01

    Tectonic tremor is a low frequency seismic signal lacking impulsive body wave arrivals, but including low and very-low frequency earthquakes. The seismic signal is interpreted to be associated with shear failure at the tremor source, and has been detected on well-instrumented subduction and transform plate boundary interfaces. Tectonic tremor has now been detected at a wide range of depths, but appears to predominantly occur in regions of transitional frictional behavior. To create the low and very-low frequency earthquakes within the tremor signal, frictional failure with a low stress drop is required at the tremor source. A common inference is therefore that tremor involves shear failure at low effective normal stress. Incrementally formed slickenfibre veins are commonly observed in exhumed fault zones. Based on the angle between shear surfaces and tensile veins, slickenfibres can in some locations be shown to have formed incrementally at low effective stress, comparable to tectonic tremor. The veins show slip increments of 10 - 100 micrometers, and along-strike lengths of tens to hundreds of meters, in agreement with values predicted from low frequency earthquake signals. Although slickenfibre veins are a candidate for the geological fingerprint of tectonic tremor, the tremor source occurs over a depth and temperature range that involves several grain scale deformation mechanisms, and both pro- and retrograde metamorphic conditions. The mechanism may therefore be more fundamental, and relate to shear failure in a mixed rheology rock assemblage where ambient stress levels are low. This includes shear failure on weak, frictional discontinuities within bulk viscous rheologies, as can be expected within the frictional transition zones where tremor is observed, independently of metamorphic grade. Slickenfibre veins represent one type of preserved shear discontinuity, on which it is easy to determine past slip increments. We show a number of other examples of

  15. Multi-level continuous active source seismic monitoring (ML-CASSM): Application to shallow hydrofracture monitoring

    NASA Astrophysics Data System (ADS)

    Ajo Franklin, J. B.; Daley, T. M.; Butler-Veytia, B.; Peterson, J.; Gasperikova, E.; Hubbard, S. S.

    2010-12-01

    Induced subsurface processes occur over a wide variety of time scales ranging from seconds (e.g. fracture initiation) to days (e.g. unsteady multiphase flow) and weeks (e.g. induced mineral precipitation). Active source seismic monitoring has the potential to dynamically characterize such alterations and allow estimation of spatially localized rates. However, even optimal timelapse seismic surveys have limited temporal resolution due to both the time required to acquire a survey and the cost of continuous field deployment of instruments and personnel. Traditional timelapse surveys are also limited by experimental repeatability due to a variety of factors including geometry replication and near-surface conditions. Recent research has demonstrated the value of semi-permanently deployed seismic systems with fixed sources and receivers for use in monitoring a variety of processes including near-surface stress changes (Silver et.al. 2007), subsurface movement of supercritical CO2 (Daley et.al. 2007), and preseismic velocity changes in fault regions (Niu et. al. 2008). This strategy, referred to as continuous active source seismic monitoring (CASSM), allows both precise quantification of traveltime changes on the order of 1.1 x 10-7 s and temporal sampling on the order of minutes. However, as previously deployed, CASSM often sacrifices spatial resolution for temporal resolution with previous experiments including only a single source level. We present results from the first deployment of CASSM with a large number of source levels under automated control. Our system is capable of autonomously acquiring full tomographic datasets (10 sources, 72 receivers) in 3 minutes without human intervention, thus allowing active source seismic imaging (rather than monitoring) of processes with short durations. Because no sources or receivers are moved in the acquisition process, signal repeatability is excellent and subtle waveform changes can be interpreted with increased confidence

  16. Conditioned activity and the interaction of amphetamine experience with morphine's activity effects.

    PubMed

    Krank, M D; Bennett, D

    1987-11-01

    This experiment assessed the transfer effect of Pavlovian conditioning with d-amphetamine sulfate (1 mg/kg) on morphine's activity effects. Prior experience with amphetamine resulted in higher levels of activity when challenged with morphine (10 and 20 mg/kg). This interactive effect of amphetamine, however, was present only in those animals who had experienced amphetamine paired with the activity test situation. Animals who had received equivalent doses of amphetamine unpaired with the testing environment did not differ from drug-naive control animals. Analysis of predrug activity levels revealed a conditioned activity response in paired animals compared to the controls. These findings suggest that the response interaction between drug conditioned responses and drug unconditioned responses is an important determinant of cross-drug effects between drugs of different pharmacological classes.

  17. Experiences from tsunami relief activity: implications for medical education

    PubMed Central

    Balasubramaniam, Sudharsanam Manni; Mohan, Yogesh; Roy, Gautam

    2012-01-01

    A tsunami struck the coast of Tamilnadu and Pondicherry on 26 December 2004. Jawaharlal Institute of Postgraduate Medical Education & Research, (JIPMER) in Pondicherry played a vital role in providing medical relief. The experiences from the relief activities revealed areas of deficiency in medical education in regards to disaster preparedness. A qualitative study using focus group discussion was employed to find the lacunae in skills in managing medical relief measures. Many skills were identified; the most important of which was addressing the psychological impact of the tsunami on the victims. Limited coordination and leadership skills were also identified. It is recommended that activity-based learning can be included in the curriculum to improve these skills. PMID:26451183

  18. Laser ion source activities at Brookhaven National Laboratory

    DOE PAGES

    Kanesue, Takeshi; Okamura, Masahiro

    2015-07-31

    In Brookhaven National Laboratory (BNL), we have been developing laser ion sources for diverse accelerators. Tabletop Nd:YAG lasers with up to several Joules of energy are mainly used to create ablation plasmas for stable operations. The obtained charge states depend on laser power density and target species. Two types of ion extraction schemes, Direct Plasma Injection Scheme (DPIS) and conventional static extraction, are used depending on application. We optimized and select a suitable laser irradiation condition and a beam extraction scheme to meet the requirement of the following accelerator system. We have demonstrated to accelerate more than 5 x 1010more » of C6+ ions using the DPIS. We successfully commissioned low charge ion beam provider to the user facilities in BNL. As a result, to achieve higher current, higher charge state and lower emittance, further studies will continue.« less

  19. Laser ion source activities at Brookhaven National Laboratory

    SciTech Connect

    Kanesue, Takeshi; Okamura, Masahiro

    2015-07-31

    In Brookhaven National Laboratory (BNL), we have been developing laser ion sources for diverse accelerators. Tabletop Nd:YAG lasers with up to several Joules of energy are mainly used to create ablation plasmas for stable operations. The obtained charge states depend on laser power density and target species. Two types of ion extraction schemes, Direct Plasma Injection Scheme (DPIS) and conventional static extraction, are used depending on application. We optimized and select a suitable laser irradiation condition and a beam extraction scheme to meet the requirement of the following accelerator system. We have demonstrated to accelerate more than 5 x 1010 of C6+ ions using the DPIS. We successfully commissioned low charge ion beam provider to the user facilities in BNL. As a result, to achieve higher current, higher charge state and lower emittance, further studies will continue.

  20. Background and Source Term Identification in Active Neutron Interrogation Methods

    DTIC Science & Technology

    2011-03-24

    low MeV neutron energy range, the increased numbers of neutrons from scattering ...reactions for low neutron energy . For U-235, low energy neutrons (thermal neutrons ) are more likely to cause fission than inelastic scattering or...manner. Active neutron interrogation is a sought after method for this since the resulting high energy gamma rays produced by inelastic scattering

  1. A 12 years brazilian space education activity experience

    NASA Astrophysics Data System (ADS)

    Stancato, Fernando; Gustavo Catalani Racca, João; Ballarotti, MaurícioG.

    2001-03-01

    A multidisciplinary group of students from the university and latter also from the high school was formed in 1988 with the objective to make them put in practice their knowledge in physics, chemistry and mathematics and engineering fields in experimental rocketry. The group was called "Grupo de Foguetes Experimentais", GFE. Since that time more than 150 students passed throw the group and now many of them are in the space arena. The benefits for students in a space hands-on project are many: More interest in their school subjects is gotten as they see an application for them; Interrelation attitudes are learned as space projects is a team activity; Responsibility is gained as each is responsible for a part of a critical mission project; Multidisciplinary and international experience is gotten as these are space project characteristics; Learn how to work in a high stress environment as use to be a project launch. This paper will cover the educational experiences gotten during these years and how some structured groups work. It is explained the objectives and how the group was formed. The group structure and the different phases that at each year the new team passes are described. It is shown the different activities that the group uses to do from scientific seminars, scientific club and international meetings to technical tours and assistance to rocket activities in regional schools. It is also explained the group outreach activities as some launches were covered by the media in more then 6 articles in newspaper and 7 television news. In 1999 as formed an official group called NATA, Núcleo de Atividades Aerospaciais within the Universidade Estadual de Londrina, UEL, by some GFE members and teachers from university. It is explained the first group project results.

  2. Numerical investigation of the seismo-acoustic responses of the Source Physics Experiment underground explosions

    NASA Astrophysics Data System (ADS)

    Antoun, T.; Ezzedine, S. M.; Vorobiev, O.; Glenn, L. A.

    2015-12-01

    We have performed three-dimensional high resolution simulations of underground explosions conducted recently in jointed rock outcrop as part of the Source Physics Experiment (SPE) being conducted at the Nevada National Security Site (NNSS). The main goal of the current study is to investigate the effects of the structural and geomechanical properties on the spall phenomena due to underground explosions and its subsequent effect on the seismo-acoustic signature at far distances. Two parametric studies have been undertaken to assess the impact of different 1) conceptual geological models including a single layer and two layers model, with and without joints and with and without varying geomechanical properties, and 2) depth of bursts of the explosions and explosion yields. Through these investigations we have explored not only the near-field response of the explosions but also the far-field responses of the seismic and the acoustic signatures. The near-field simulations were conducted using the Eulerian and Lagrangian codes, GEODYN and GEODYN -L, respectively, while the far-field seismic simulations were conducted using the elastic wave propagation code, WPP, and the acoustic response using the Kirchhoff-Helmholtz-Rayleigh time-dependent approximation code, KHR. Though a series of simulations, we have recorded the velocity field histories a) at the ground surface on an acoustic-source-patch for the acoustic simulations, and 2) on a seismic-source-box for the seismic simulations. We first analyzed the SPE3 and SPE4-prime experimental data and simulated results, and then simulated SPE5, SPE6/7 to anticipate their seismo-acoustic responses given conditions of uncertainties. SPE experiments were conducted in a granitic formation; we have extended the parametric study to include other geological settings such dolomite and alluvial formations. These parametric studies enabled us 1) investigating the geotechnical and geophysical key parameters that impact the seismo

  3. Measurement cells of the Spallation Neutron Source neutron Electric Dipole Moment experiment

    NASA Astrophysics Data System (ADS)

    Leung, Kent; SNS nEDM Collaboration

    2016-09-01

    The Spallation Neutron Source (SNS) neutron Electric Dipole Moment (nEDM) experiment will use 3 L rectangular measurement cells filled with superfluid helium at 0.3 - 0.5 K with a 10-10 fraction of polarized 3He. These cells are made from 0.5 in thick PMMA plates, coated with a mixture of deuterated polystyrene and deuterated tetraphenyl butadiene and then glued together with deuterated acrylic cement. The experiment requires the cells to be: non-magnetic, non-conducting, fluorescent at the inner surface for VUV photons, optically transparent, cryogenic-friendly, polarized 3He friendly, and have long ultracold neutron (UCN) storage times. The successful production of full-sized cells and how these cells address each of the above requirements, will be presented. Focus will be given on recent UCN storage tests of several cells measured between 90 K to 20 K. These results demonstrate the cryogenic robustness of these cells and UCN loss f-factors of 2 ×10-5 , better than beryllium at low temperatures. A previous problem of gaps or uncovered patches exposed on the inside of the cell has been resolved. Exploratory work on new polymer coatings that could improve our cells further will also be presented. DE-FG02-97ER41042.

  4. Column Experiments of Smouldering Combustion as a Remediation Technology for NAPL Source Zones

    NASA Astrophysics Data System (ADS)

    Pironi, P.; Switzer, C.; Rein, G.; Torero, J. L.; Gerhard, J. I.

    2008-12-01

    Smouldering combustion is an innovative approach that has significant potential for the remediation of industrial sites contaminated by non-aqueous phase liquids (NAPLs). Many common liquid contaminants, including coal tar, solvents, oils and petrochemicals are combustible and release significant amounts of heat when burned. Smouldering combustion is the flameless burning of a condensed fuel that derives heat from surface oxidation reactions. Gerhard et al., 2006 (Eos Trans., 87(52), Fall Meeting Suppl. H24A) presented proof-of-concept experiments demonstrating that NAPLs embedded in a porous medium may be effectively destroyed via smouldering. Based upon that work, it was hypothesized that the process can be self- sustaining, such that, a short duration energy input (i.e., ignition) at a single location is sufficient to generate a reaction that propagates itself through the NAPL source zone until the NAPL is eliminated, provided that enough air is injected into the soil. In this work, this hypothesis is proven via column experiments at the intermediate bench scale (~ 30 cm) utilizing coal tar-contaminated quartz sands. Over 30 such experiments examine the sensitivity of NAPL smouldering to a series of fluid-media system variables and engineering control parameters, including contaminant type, NAPL saturation, water saturation, porous media type and air injection rate. Diagnostic techniques employed to characterize the results include temperature mapping, off-gas analysis (via FTIR), heat front mapping via digital imaging, and pre- and post-treatment soil analysis. The derived relationships between the manipulated system variables and experimental results are providing understanding of the mechanisms controlling the ignition and propagation of liquid smouldering. Such insight is necessary for the ongoing design of both ex situ and in situ pilot applications.

  5. Report on active and planned spacecraft and experiments

    NASA Technical Reports Server (NTRS)

    Schofield, N. J., Jr.; Littlefield, R. G.; Elsen, M. F.

    1985-01-01

    This report provides the professional community with information on current and planned spacecraft activity (including both free-flying spacecraft and Shuttle-attached payloads) for a broad range of scientific disciplines. By providing a brief description of each spacecraft and experiment as well as its current status, it is hoped that this document will be useful to many people interested in the scientific, applied, and operational uses of the data collected. Furthermore, for those investigators who are planning or coordinating future observational programs employing a number of different techniques such as rockets, balloons, aircraft, ships, and buoys, this document can provide some insight into the contributions that may be provided by orbiting instruments. The document includes information concerning active and planned spacecraft and experiments. The information covers a wide range of scientific disciplines: astronomy, earth sciences, meteorology, planetary sciences, aeronomy, particles and fields, solar physics, life sciences, and material sciences. These spacecraft projects represent the efforts and funding of individual countries, as well as cooperative arrangements among different countries.

  6. On the altitude of the ELF/VLF source region generated during “beat-wave” HF heating experiments

    NASA Astrophysics Data System (ADS)

    Moore, R. C.; Fujimaru, S.; Cohen, M.; Gołkowski, M.; McCarrick, M. J.

    2012-09-01

    Modulated high frequency (HF, 3-10 MHz) heating of the ionosphere in the presence of the auroral electrojet currents is an effective method for generating extremely low frequency (ELF, 3-3000 Hz) and very low frequency (VLF, 3-30 kHz) radio waves. The amplitudes of ELF/VLF waves generated in this manner depend sensitively on the auroral electrojet current strength, which varies with time. In an effort to improve the reliability of ELF/VLF wave generation by ionospheric heating, recent experiments at the High-frequency Active Auroral Research Program (HAARP) facility in Gakona, Alaska, have focused on methods that are independent of the strength of the auroral electrojet currents. One such potential method is so-called “beat-wave” ELF/VLF generation. Recent experimental observations have been presented to suggest that in the absence of a significant D-region ionosphere (˜60-100 km altitude), an ELF/VLF source region can be created within the F-region ionosphere (˜150-250 km altitude). In this paper, we use a time-of-arrival analysis technique to provide direct experimental evidence that the beat-wave source region is located in the D-region ionosphere, and possibly the lower E-region ionosphere (˜100-120 km altitude), even when ionospheric diagnostics indicate a very weak D-layer. These results have a tremendous impact on the interpretation of recent experimental observations.

  7. Active Neutron-Based Interrogation System with D-D Neutron Source for Detection of Special Nuclear Materials

    NASA Astrophysics Data System (ADS)

    Takahashi, Y.; Misawa, T.; Yagi, T.; Pyeon, C. H.; Kimura, M.; Masuda, K.; Ohgaki, H.

    2015-10-01

    The detection of special nuclear materials (SNM) is an important issue for nuclear security. The interrogation systems used in a sea port and an airport are developed in the world. The active neutron-based interrogation system is the one of the candidates. We are developing the active neutron-based interrogation system with a D-D fusion neutron source for the nuclear security application. The D-D neutron source is a compact discharge-type fusion neutron source called IEC (Inertial-Electrostatic Confinement fusion) device which provides 2.45 MeV neutrons. The nuclear materials emit the highenergy neutrons by fission reaction. High-energy neutrons with energies over 2.45 MeV amount to 30% of all the fission neutrons. By using the D-D neutron source, the detection of SNMs is considered to be possible with the attention of fast neutrons if there is over 2.45 MeV. Ideally, neutrons at En>2.45 MeV do not exist if there is no nuclear materials. The detection of fission neutrons over 2.45 MeV are hopeful prospect for the detection of SNM with a high S/N ratio. In the future, the experiments combined with nuclear materials and a D-D neutron source will be conducted. Furthermore, the interrogation system will be numerically investigated by using nuclear materials, a D-D neutron source, and a steel container.

  8. Quantifying the sources of error in measurements of urine activity

    SciTech Connect

    Mozley, P.D.; Kim, H.J.; McElgin, W.

    1994-05-01

    Accurate scintigraphic measurements of radioactivity in the bladder and voided urine specimens can be limited by scatter, attenuation, and variations in the volume of urine that a given dose is distributed in. The purpose of this study was to quantify some of the errors that these problems can introduce. Transmission scans and 41 conjugate images of the bladder were sequentially acquired on a dual headed camera over 24 hours in 6 subjects after the intravenous administration of 100-150 MBq (2.7-3.6 mCi) of a novel I-123 labeled benzamide. Renal excretion fractions were calculated by measuring the counts in conjugate images of 41 sequentially voided urine samples. A correction for scatter was estimated by comparing the count rates in images that were acquired with the photopeak centered an 159 keV and images that were made simultaneously with the photopeak centered on 126 keV. The decay and attenuation corrected, geometric mean activities were compared to images of the net dose injected. Checks of the results were performed by measuring the total volume of each voided urine specimen and determining the activity in a 20 ml aliquot of it with a dose calibrator. Modeling verified the experimental results which showed that 34% of the counts were attenuated when the bladder had been expanded to a volume of 300 ml. Corrections for attenuation that were based solely on the transmission scans were limited by the volume of non-radioactive urine in the bladder before the activity was administered. The attenuation of activity in images of the voided wine samples was dependent on the geometry of the specimen container. The images of urine in standard, 300 ml laboratory specimen cups had 39{plus_minus}5% fewer counts than images of the same samples laid out in 3 liter bedpans. Scatter through the carbon fiber table substantially increased the number of counts in the images by an average of 14%.

  9. Experiment on search for neutron–antineutron oscillations using a projected UCN source at the WWR-M reactor

    NASA Astrophysics Data System (ADS)

    Fomin, A. K.; Serebrov, A. P.; Zherebtsov, O. M.; Leonova, E. N.; Chaikovskii, M. E.

    2017-01-01

    We propose an experiment on search for neutron–antineutron oscillations based on the storage of ultracold neutrons (UCN) in a material trap. The sensitivity of the experiment mostly depends on the trap size and the amount of UCN in it. In Petersburg Nuclear Physics Institute (PNPI) a high-intensity UCN source is projected at the WWR-M reactor, which must provide UCN density 2-3 orders of magnitude higher than existing sources. The results of simulations of the designed experimental scheme show that the sensitivity can be increased by ∼ 10–40 times compared to sensitivity of previous experiment depending on the model of neutron reflection from walls.

  10. DrSPINE - New approach to data reduction and analysis for neutron spin echo experiments from pulsed and reactor sources

    SciTech Connect

    Monkenbusch, Michael; Holderer, Olaf; Ohl, Michael

    2015-01-01

    Neutron spin echo (NSE) method at a pulsed neutron source presents new challenges to the data reduction and analysis as compared to the instruments installed at reactor sources. The main advantage of the pulsed source NSE is the ability to resolve the neutron wavelength and collect neutrons over a wider bandwidth. This allows us to more precisely determine the symmetry phase and measure the data for several Q-values at the same time. Based on the experience gained at the SNS NSE - the first, and to date the only one, NSE instrument installed at a pulsed spallation source, we propose a novel and unified approach to the NSE data processing.

  11. Energy cost and energy sources during a simulated firefighting activity.

    PubMed

    Perroni, Fabrizio; Tessitore, Antonio; Cortis, Cristina; Lupo, Corrado; D'artibale, Emanuele; Cignitti, Lamberto; Capranica, Laura

    2010-12-01

    This study aimed to 1) analyze the energy requirement (VO2eq) and the contribution of the aerobic (VO2ex), anaerobic alactic (VO2al), and anaerobic lactic (VO2la-) energy sources of a simulated intervention; 2) ascertain differences in mean VO2 and heart rate (HR) during firefighting tasks; and 3) verify the relationship between time of job completion and the fitness level of firefighters. Twenty Italian firefighters (age = 32 ± 6 yr, VO2peak = 43.1 ± 4.9 mL·kg·min) performed 4 consecutive tasks (i.e., child rescue; 250-m run; find an exit; 250-m run) that required a VO2eq of 406.26 ± 73.91 mL·kg (VO2ex = 86 ± 5%; VO2al = 9 ± 3%; VO2la- = 5 ± 3%). After 30 minutes, the recovery HR (108 ± 15 beats·min) and VO2 (8.86±2.67mL·kg·min) were higher (p < 0.0001) than basal values (HR = 66 ± 8 beats·min; VO2 = 4.57 ± 1.07 mL·kg·min), indicating that passive recovery is insufficient in reducing the cardiovascular and thermoregulatory strain of the previous workload. Differences (p < 0.001) between tasks emerged for mean VO2 and HR, with a lack of significant correlation between the time of job completion and the firefighters' aerobic fitness. These findings indicate that unpredictable working conditions highly challenge expert firefighters who need adequate fitness levels to meet the requirements of their work. Practically, to enhance the fitness level of firefighters, specific interval training programs should include a wide variety of tasks requiring different intensities and decision-making strategies.

  12. The solar activity measurements experiments (SAMEX) for improved scientific understanding of solar activity

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The Solar Activity Measurements Experiments (SAMEX) mission is described. It is designed to provide a look at the interactions of magnetic fields and plasmas that create flares and other explosive events on the sun in an effort to understand solar activity and the nature of the solar magnetic field. The need for this mission, the instruments to be used, and the expected benefits of SAMEX are discussed.

  13. Generation of Acoustic-Gravity Waves in Ionospheric HF Heating Experiments: Simulating Large-Scale Natural Heat Sources

    NASA Astrophysics Data System (ADS)

    Pradipta, Rezy

    In this thesis, we investigate the potential role played by large-scale anomalous heat sources (e.g. prolonged heat wave events) in generating acoustic-gravity waves (AGWs) that might trigger widespread plasma turbulence in the ionospheric layer. The main hypothesis is that, the thermal gradients associated with the heat wave fronts could act as a source of powerful AGW capable of triggering ionospheric plasma turbulence over extensive areas. In our investigations, first we are going to examine a case study of the summer 2006 North American heat wave event. Our examination of GPS-derived total electron content (TEC) data over the North American sector reveals a quite noticeable increase in the level of daily plasma density fluctuations during the summer 2006 heat wave period. Comparison with the summer 2005 and summer 2007 data further confirms that the observed increase of traveling ionospheric disturbances (TIDs) during the summer 2006 heat wave period was not simply a regular seasonal phenomenon. Furthermore, a series of field experiments had been carried out at the High-frequency Active Auroral Research Program (HAARP) facility in order to physically simulate the process of AGW/TID generation by large-scale thermal gradients in the ionosphere. In these ionospheric HF heating experiments, we create some time-varying artificial thermal gradients at an altitude of 200--300 km above the Earth's surface using vertically-transmitted amplitude-modulated 0-mode HF heater waves. For our experiments, a number of radio diagnostic instruments had been utilized to detect the characteristic signatures of heater-generated AGW/TID. So far, we have been able to obtain several affirmative indications that some artificial AGW/TID are indeed being radiated out from the heated plasma volume during the HAARP-AGW experiments. Based on the experimental evidence, we may conclude that it is certainly quite plausible for large-scale thermal gradients associated with severe heat wave

  14. When seeing the same physician, highly activated patients have better care experiences than less activated patients.

    PubMed

    Greene, Jessica; Hibbard, Judith H; Sacks, Rebecca; Overton, Valerie

    2013-07-01

    Measures of the patient care experience are now routinely used in public reports and increasingly influence health provider payment. We examined data from 5,002 patients of forty-nine primary care providers to explore the relationship between patient activation-a term referring to the knowledge, skills, and confidence a patient has for managing his or her health care-and the patient care experience. We found that patients at higher levels of activation had more positive experiences than patients at lower levels seeing the same clinician. The observed differential was maintained when we controlled for demographic characteristics and health status. We did not find evidence that patients at higher levels of activation selected providers who were more patient-centric. The findings suggest that the care experience is transactional, shaped by both providers and patients. Strategies to improve the patient experience, therefore, should focus not only on providers but also on improving patients' ability to elicit what they need from their providers.

  15. Rock Valley Source Physics Experiment Preparation: Earthquake Relocation and Attenuation Structure Characterization

    NASA Astrophysics Data System (ADS)

    Pyle, M. L.; Walter, W. R.; Myers, S.; Pasyanos, M. E.; Smith, K. D.

    2012-12-01

    The science of nuclear test monitoring relies on seismic methods to distinguish explosion from earthquakes sources. Unfortunately, the physics behind how an explosion generates seismic waves, particularly shear waves, remains incompletely understood. The Source Physics Experiments (SPE) are an ongoing series of chemical explosions designed to address this problem and advance explosion monitoring physics and associated simulation codes. The current series of explosions are located in the Climax Stock granite on the Nevada National Security Site (NNSS). A future candidate for the SPEs would allow us to make a direct comparison of earthquake and explosion sources by detonating an explosion at a well constrained earthquake hypocenter and recording the resulting signals from each source at common receivers. This possibility arises from an area of unusually shallow seismicity in the Rock Valley area of the southern NNSS. While most tectonic earthquakes occur at depths greater than 5 km, a sequence of unusually shallow earthquakes with depths of 1-2 km occurred in Rock Valley in May of 1993. The main shock had a magnitude of approximately 3.7 and 11 more events in the sequence had magnitudes over 2. The shallow depths of these events were well constrained by temporary stations deployed at the time by the University of Nevada-Reno (UNR). As part of a feasibility study for a future Rock Valley SPE, LLNL, UNR and NSTec are working to re-instrument and improve our understanding of the Rock Valley region. Rock Valley is a complex set of left oblique-slip segmented fault blocks; it is a regular source region for small magnitude shallow earthquakes. A dense seismic network was operated in the southern NNSS through the Yucca Mountain project (1992-2010). Although much of the older network has been removed, six new Rock Valley telemetered seismic stations located at both original 1993 sites and additional sites, have been installed and operating since early 2011. In order to

  16. Active experiments and single ion motion in the magnetotail

    NASA Astrophysics Data System (ADS)

    Rothwell, P. L.; Yates, G. K.

    1983-07-01

    Analytic solutions to the Lorentz equation which indicate that the magnetic field in the plasma sheet focuses selected ions from the plasma sheet boundaries on the neutral sheet are obtained. The kinetic energy of these ions usually exceeds the threshold energy required for the ion tearing mode instability. Two active experiments based on this effect are proposed. Heavy ions injected towards dusk on the plasma sheet boundary would become focused on the neutral sheet and perhaps trigger the ion tearing mode. A boundary perturbation, such as a thermal chemical release, that locally enhances the boundary turbulence level could be introduced, causing sufficient ksq = 1 ions to be focused on the neutral sheet to trigger the ion tearing mode.

  17. Effect of Anisotropic Velocity Structure on Acoustic Emission Source Location during True-Triaxial Deformation Experiments

    NASA Astrophysics Data System (ADS)

    Ghofrani Tabari, Mehdi; Goodfellow, Sebastian; Young, R. Paul

    2016-04-01

    Although true-triaxial testing (TTT) of rocks is now more extensive worldwide, stress-induced heterogeneity due to the existence of several loading boundary effects is not usually accounted for and simplified anisotropic models are used. This study focuses on the enhanced anisotropic velocity structure to improve acoustic emission (AE) analysis for an enhanced interpretation of induced fracturing. Data from a TTT on a cubic sample of Fontainebleau sandstone is used in this study to evaluate the methodology. At different stages of the experiment the True-Triaxial Geophysical Imaging Cell (TTGIC), armed with an ultrasonic and AE monitoring system, performed several velocity surveys to image velocity structure of the sample. Going beyond a hydrostatic stress state (poro-elastic phase), the rock sample went through a non-dilatational elastic phase, a dilatational non-damaging elasto-plastic phase containing initial AE activity and finally a dilatational and damaging elasto-plastic phase up to the failure point. The experiment was divided into these phases based on the information obtained from strain, velocity and AE streaming data. Analysis of the ultrasonic velocity survey data discovered that a homogeneous anisotropic core in the center of the sample is formed with ellipsoidal symmetry under the standard polyaxial setup. Location of the transducer shots were improved by implementation of different velocity models for the sample starting from isotropic and homogeneous models going toward anisotropic and heterogeneous models. The transducer shot locations showed a major improvement after the velocity model corrections had been applied especially at the final phase of the experiment. This location improvement validated our velocity model at the final phase of the experiment consisting lower-velocity zones bearing partially saturated fractures. The ellipsoidal anisotropic velocity model was also verified at the core of the cubic rock specimen by AE event location of

  18. Activation processes on GaAs photocathode by different currents of oxygen source

    NASA Astrophysics Data System (ADS)

    Miao, Zhuang; Shi, Feng; Cheng, Hongchang; Wang, Shufei; Zhang, Xiaohui; Yuan, Yuan; Chen, Chang

    2015-04-01

    In order to know the influence of activation processes on GaAs photocathodes, three GaAs samples were activated by a fixed current of cesium source and different currents of oxygen source. The current of caesium source is same during activation to ensure initial adsorption of caesium quantum is similar, which is the base to show the difference during alternation activation of caesium and oxygen. Analysed with the activation data, it is indicated that Cs-to-O current ratio of 1.07 is the optimum ratio to obtain higher sensitivity and better stability. According to double dipole model, stable and uniform double dipole layers of GaAs-O-Cs:Cs-O-Cs are formed and negative electron affinity is achieved on GaAs surface by activation with cesium and oxygen. The analytical result is just coincident with the model. Thus there is an efficient technological method to improve sensitivity and stability of GaAs photocathode.

  19. Dr. Gerald Fishman Working on the Burst and Transient Source Experiment (BATSE)

    NASA Technical Reports Server (NTRS)

    1991-01-01

    In this photograph, Dr. Gerald Fishman of the Marshall Space Flight Center (MSFC), a principal investigator of the Compton Gamma-Ray Observatory's (GRO's) instrument, the Burst and Transient Source Experiment (BATSE), works on the BATSE detector module. For nearly 9 years, GRO's BATSE, designed and built by MSFC, kept an unblinking watch on the universe to alert scientist to the invisible, mysterious gamma-ray bursts. By studying gamma-rays from objects like black holes, pulsars, quasars, neutron stars, and other exotic objects, scientists could discover clues to the birth, evolution, and death of star, galaxies, and the universe. The gamma-ray instrument was one of four major science instruments aboard the Compton. It consisted of eight detectors, or modules, located at each corner of the rectangular satellite to simultaneously scan the entire universe for bursts of gamma-rays ranging in duration from fractions of a second to minutes. Because gamma-rays are so powerful, they pass through conventional telescope mirrors. Instead of a mirror, the heart of each BATSE module was a large, flat, transparent crystal that generated a tiny flash of light when struck by a gamma-ray. With an impressive list of discoveries and diverse accomplishments, BATSE could claim to have rewritten astronomy textbooks. Launched aboard the Space Shuttle Orbiter Atlantis during the STS-35 mission in April 1991, the GRO reentered the Earth's atmosphere and ended its successful 9-year mission in June 2000.

  20. Development of plasma sources for ICRF heating experiment in KMAX mirror device

    NASA Astrophysics Data System (ADS)

    Sun, Xuan; Liu, Ming; Yi, Hongshen; Lin, Munan; Shi, Peiyun

    2016-10-01

    KMAX, Keda Mirror with AXisymmeticity, is a tandem mirror machine with a length of 10 meters and diameters of 1.2 meters in the central cell and 0.3 meters in the mirror throat. In the past experiments, the plasma was generated by helicon wave launched from the west end. We obtained the blue core mode in argon discharge, however, it cannot provide sufficient plasma for hydrogen discharge, which is at least 1012 cm-3 required for effective ICRF heating. Several attempts have thus been tried or under design to increase the central cell's plasma density: (1) a washer gun with aperture of 1cm has been successfully tested, and a plasma density of 1013 cm-3 was achieved in the west cell near the gun, however, the plasma is only 1011 cm-3 in the central cell possible due to the mirror trapping and/or neutral quenching effect (2) a larger washer gun with aperture of 2.5 cm and a higher power capacitor bank are being assembled in order to generate more plasmas. In addition, how to mitigate the neutrals is under consideration (3) A hot cathode is been designed and will be tested in combination with plasma gun or alone. Preliminary results from those plasma sources will be presented and discussed.

  1. Background Studies at the Spallation Neutron Source for the COHERENT Experiment

    NASA Astrophysics Data System (ADS)

    Heath, Matthew; Coherent Collaboration

    2016-09-01

    The COHERENT experiment is attempting a first measurement of coherent elastic neutrino-nucleus scattering (CEvNS) at the Spallation Neutron Source (SNS) at Oak Ridge National Lab. CEvNS is a standard model process that is important in understanding supernova neutrinos, the structure of the weak interaction, and as a background for dark matter searches. COHERENT is placing a suite of four detector technologies in a basement location at the SNS: point contact germanium detectors, CsI[Na] crystals, NaI[Tl] crystals, and single phase liquid argon. Previous attempts to measure the CEvNS process have grappled with very high rates of backgrounds due to the low energy thresholds required. Accelerator-correlated neutrons are the most troublesome background for COHERENT because a simple accelerator on/off background subtraction procedure fails to remove them. To understand these backgrounds, COHERENT features measurements from the SciBath detector and the Sandia Neutron Scatter Camera (NSC). Important neutron measurements from both SciBath and the NSC, as well as gamma measurements from the SNS basement location where the four detector technologies for COHERENT will be placed will be discussed. COHERENT collaborators are supported by the U. S. Department of Energy Office of Science, the National Science Foundation, NASA, and the Sloan Foundation.

  2. The MYTHEN detector for X-ray powder diffraction experiments at the Swiss Light Source

    PubMed Central

    Bergamaschi, Anna; Cervellino, Antonio; Dinapoli, Roberto; Gozzo, Fabia; Henrich, Beat; Johnson, Ian; Kraft, Philipp; Mozzanica, Aldo; Schmitt, Bernd; Shi, Xintian

    2010-01-01

    The MYTHEN single-photon-counting silicon microstrip detector has been developed at the Swiss Light Source for time-resolved powder diffraction experiments. An upgraded version of the detector has been installed at the SLS powder diffraction station allowing the acquisition of diffraction patterns over 120° in 2θ in fractions of seconds. Thanks to the outstanding performance of the detector and to the calibration procedures developed, the quality of the data obtained is now comparable with that of traditional high-resolution point detectors in terms of FWHM resolution and peak profile shape, with the additional advantage of fast and simultaneous acquisition of the full diffraction pattern. MYTHEN is therefore optimal for time-resolved or dose-critical measurements. The characteristics of the MYTHEN detector together with the calibration procedures implemented for the optimization of the data are described in detail. The refinements of two known standard powders are discussed together with a remarkable application of MYTHEN to organic compounds in relation to the problem of radiation damage. PMID:20724787

  3. Flame Experiments at the Advanced Light Source: New Insights into Soot Formation Processes

    PubMed Central

    Hansen, Nils; Skeen, Scott A.; Michelsen, Hope A.; Wilson, Kevin R.; Kohse-Höinghaus, Katharina

    2014-01-01

    The following experimental protocols and the accompanying video are concerned with the flame experiments that are performed at the Chemical Dynamics Beamline of the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory1-4. This video demonstrates how the complex chemical structures of laboratory-based model flames are analyzed using flame-sampling mass spectrometry with tunable synchrotron-generated vacuum-ultraviolet (VUV) radiation. This experimental approach combines isomer-resolving capabilities with high sensitivity and a large dynamic range5,6. The first part of the video describes experiments involving burner-stabilized, reduced-pressure (20-80 mbar) laminar premixed flames. A small hydrocarbon fuel was used for the selected flame to demonstrate the general experimental approach. It is shown how species’ profiles are acquired as a function of distance from the burner surface and how the tunability of the VUV photon energy is used advantageously to identify many combustion intermediates based on their ionization energies. For example, this technique has been used to study gas-phase aspects of the soot-formation processes, and the video shows how the resonance-stabilized radicals, such as C3H3, C3H5, and i-C4H5, are identified as important intermediates7. The work has been focused on soot formation processes, and, from the chemical point of view, this process is very intriguing because chemical structures containing millions of carbon atoms are assembled from a fuel molecule possessing only a few carbon atoms in just milliseconds. The second part of the video highlights a new experiment, in which an opposed-flow diffusion flame and synchrotron-based aerosol mass spectrometry are used to study the chemical composition of the combustion-generated soot particles4. The experimental results indicate that the widely accepted H-abstraction-C2H2-addition (HACA) mechanism is not the sole molecular growth process responsible for the formation of the

  4. Flame experiments at the advanced light source: new insights into soot formation processes.

    PubMed

    Hansen, Nils; Skeen, Scott A; Michelsen, Hope A; Wilson, Kevin R; Kohse-Höinghaus, Katharina

    2014-05-26

    The following experimental protocols and the accompanying video are concerned with the flame experiments that are performed at the Chemical Dynamics Beamline of the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory(1-4). This video demonstrates how the complex chemical structures of laboratory-based model flames are analyzed using flame-sampling mass spectrometry with tunable synchrotron-generated vacuum-ultraviolet (VUV) radiation. This experimental approach combines isomer-resolving capabilities with high sensitivity and a large dynamic range(5,6). The first part of the video describes experiments involving burner-stabilized, reduced-pressure (20-80 mbar) laminar premixed flames. A small hydrocarbon fuel was used for the selected flame to demonstrate the general experimental approach. It is shown how species' profiles are acquired as a function of distance from the burner surface and how the tunability of the VUV photon energy is used advantageously to identify many combustion intermediates based on their ionization energies. For example, this technique has been used to study gas-phase aspects of the soot-formation processes, and the video shows how the resonance-stabilized radicals, such as C3H3, C3H5, and i-C4H5, are identified as important intermediates(7). The work has been focused on soot formation processes, and, from the chemical point of view, this process is very intriguing because chemical structures containing millions of carbon atoms are assembled from a fuel molecule possessing only a few carbon atoms in just milliseconds. The second part of the video highlights a new experiment, in which an opposed-flow diffusion flame and synchrotron-based aerosol mass spectrometry are used to study the chemical composition of the combustion-generated soot particles(4). The experimental results indicate that the widely accepted H-abstraction-C2H2-addition (HACA) mechanism is not the sole molecular growth process responsible for the formation

  5. Active source cancellation of the blade tone fundamental and harmonics in centrifugal fans

    NASA Astrophysics Data System (ADS)

    Koopmann, G. H.; Fox, D. J.; Neise, W.

    1988-10-01

    An active source method is shown to effectively cancel the blade tone fundamental and harmonics in centrifugal fans for a variety of fan loading conditions and duct terminations. The special case is considered where the frequency of the blade tone harmonics lies just above the cut-on frequency of the first higher order mode of the fan ducting. The results suggest that the present active control mechanism involves a local alteration of the aerodynamic source pressures.

  6. A diamond active target for the PADME experiment

    NASA Astrophysics Data System (ADS)

    Chiodini, G.

    2017-02-01

    The PADME (Positron Annihilation into Dark Mediator Experiment) collaboration searches for dark photons produced in the annihilation e++e-→γ+A' of accelerated positrons with atomic electrons of a fixed target at the Beam Test Facility of Laboratori Nazionali di Frascati. The apparatus can detect dark photons decaying into visible A'→e+e- and invisible A'→χχ channels, where χ's are particles of a secluded sector weakly interacting and therefore undetected. In order to improve the missing mass resolution and to measure the beam flux, PADME has an active target able to reconstruct the beam spot position and the bunch multiplicity. In this work the active target is described, which is made of a detector grade polycrystalline synthetic diamond with strip electrodes on both surfaces. The electrodes segmentation allows to measure the beam profile along X and Y and evaluate the average beam position bunch per bunch. The results of beam tests for the first two diamond detector prototypes are shown. One of them holds innovative graphitic electrodes built with a custom process developed in the laboratory, and the other one with commercially available traditional Cr-Au electrodes. The front-end electronics used in the test beam is discussed and the performance observed is presented. Finally, the final design of the target to be realized at the beginning of 2017 to be ready for data taking in 2018 is illustrated.

  7. An Overview of the Source Physics Experiments (SPE) at the Nevada National Security Site (NNSS)

    NASA Astrophysics Data System (ADS)

    Snelson, C. M.; Barker, D. L.; White, R. L.; Emmitt, R. F.; Townsend, M. J.; Graves, T. E.; Becker, S. A.; Teel, M. G.; Lee, P.; Antoun, T. H.; Rodgers, A.; Walter, W. R.; Mellors, R. J.; Brunish, W. M.; Bradley, C. R.; Patton, H. J.; Hawkins, W. L.; Corbell, B. H.; Abbott, R. E.; SPE Working Group

    2011-12-01

    Modeling of explosion phenomenology has been primarily empirically based when looking at the seismic, infrasound, and acoustic signals. In order to detect low-yield nuclear explosions under the Comprehensive Nuclear Test-Ban Treaty (CTBT), we must be able to understand and model the explosive source in settings beyond where we have empirical data. The Source Physics Experiments (SPE) at the Nevada National Security Site are the first step in this endeavor to link the empirically based with the physics-based modeling to develop this predictive capability. The current series of tests is being conducted in a granite body called the Climax Stock. This location was chosen for several reasons, including the site's expected "simple geology"-the granite is a fairly homogeneous body. In addition, data are available from underground nuclear tests that were conducted in the same rock body, and the nature of the geology has been well-documented. Among the project goals for the SPE is to provide fully coupled seismic energy to the seismic and acoustic seismic arrays so that the transition between the near and far-field data can be modeled and our scientists can begin to understand how non-linear effects and anisotropy control seismic energy transmission and partitioning. The first shot for the SPE was conducted in May 2011 as a calibration shot (SPE1) with 220 lb (100 kg) of chemical explosives set at a depth of 180 ft (55 m). An array of sensors and diagnostics recorded the shot data, including accelerometers, geophones, rotational sensors, short-period and broadband seismic sensors, Continuous Reflectometry for Radius vs. Time Experiment (CORRTEX), Time of Arrival (TOA), Velocity of Detonation (VOD) as well as infrasound sensors. The three-component accelerometer packages were set at depths of 180 ft (55 m), 150 ft (46 m), and 50 ft (15 m) in two rings around ground zero (GZ); the inner ring was at 10 m and the outer ring was 20 m from GZ. Six sets of surface accelerometers

  8. Geologic Assessment of the Damage Zone from Two Explosions at the Source Physics Experiment

    NASA Astrophysics Data System (ADS)

    Townsend, M.; Prothro, L.; Huckins-Gang, H.; Obi, C.; Reed, D.; Snelson, C. M.

    2013-12-01

    Explosive tests are being conducted in fractured granite in Nevada to increase the understanding of certain basic physical phenomena associated with underground explosions. These tests, collectively known as the Source Physics Experiment (SPE), are designed to study the generation and propagation of seismic waves. The results will help advance the seismic monitoring capability of the United States by improving the predictive capability of physics-based modeling of explosive phenomena. Three of seven planned tests have been conducted to date. All the tests have been conducted in the same source hole. The first SPE shot (SPE-1) was a Green's function test conducted at the depth of 54.9 m, with an explosive yield of 88 kg (TNT equivalent). This study addresses the second and third shots (SPE 2 and SPE-3), which were conducted at the same depth, shallower than SPE-1 and with a larger explosive yield, to explore the influence of explosion-induced damage on seismic wave propagation. SPE-2 was conducted at the depth of 45.7 m in October 2011, with a yield of 997 kg, after which an angled core hole (U-15n#10) was drilled from the surface to the shot point to characterize the damage zone. After the source hole was cleaned out, SPE-3 was conducted at 45.8 m in July 2012, with a yield of 905 kg. Following SPE-3, a second angled core hole (U-15n#12) was drilled sub-parallel to U 15n#10 to provide a comparison of explosion-induced damage between the two shots. Geophysical logs were run in both holes, core samples were provided to Sandia National Laboratories for measurement of physical and mechanical properties, and down-hole videos were made in the source hole following both tests. The presence of natural faulting near the shot point complicates the comparison of the damage from the SPE-2 and SPE-3 shots, using only information from the two similarly positioned angled core holes. Characteristics of natural fractures allow them to be distinguished from shock-induced breaks

  9. A Bridge to Active Learning: A Summer Bridge Program Helps Students Maximize Their Active-Learning Experiences and the Active-Learning Experiences of Others

    PubMed Central

    Cooper, Katelyn M.; Ashley, Michael; Brownell, Sara E.

    2017-01-01

    National calls to improve student academic success in college have sparked the development of bridge programs designed to help students transition from high school to college. We designed a 2-week Summer Bridge program that taught introductory biology content in an active-learning way. Through a set of exploratory interviews, we unexpectedly identified that Bridge students had developed sophisticated views of active learning, even though this was not an explicit goal of the program. We conducted an additional set of semistructured interviews that focused on active learning and compared the interviews of Bridge students with those from non-Bridge students who had been eligible for but did not participate in the program. We used the constant comparative method to identify themes from the interviews. We found that Bridge students perceived that, because they knew how to approach active learning and viewed it as important, they benefited more from active learning in introductory biology than non-Bridge students. Specifically, Bridge students seemed to be more aware of their own learning gains from participating in active learning. Compared with the majority of non-Bridge students, the majority of Bridge students described using a greater variety of strategies to maximize their experiences in active learning. Finally, in contrast to non-Bridge students, Bridge students indicated that they take an equitable approach to group work. These findings suggest that we may be able to prime students to maximize their own and other’s experiences in active learning. PMID:28232588

  10. A Bridge to Active Learning: A Summer Bridge Program Helps Students Maximize Their Active-Learning Experiences and the Active-Learning Experiences of Others.

    PubMed

    Cooper, Katelyn M; Ashley, Michael; Brownell, Sara E

    2017-01-01

    National calls to improve student academic success in college have sparked the development of bridge programs designed to help students transition from high school to college. We designed a 2-week Summer Bridge program that taught introductory biology content in an active-learning way. Through a set of exploratory interviews, we unexpectedly identified that Bridge students had developed sophisticated views of active learning, even though this was not an explicit goal of the program. We conducted an additional set of semistructured interviews that focused on active learning and compared the interviews of Bridge students with those from non-Bridge students who had been eligible for but did not participate in the program. We used the constant comparative method to identify themes from the interviews. We found that Bridge students perceived that, because they knew how to approach active learning and viewed it as important, they benefited more from active learning in introductory biology than non-Bridge students. Specifically, Bridge students seemed to be more aware of their own learning gains from participating in active learning. Compared with the majority of non-Bridge students, the majority of Bridge students described using a greater variety of strategies to maximize their experiences in active learning. Finally, in contrast to non-Bridge students, Bridge students indicated that they take an equitable approach to group work. These findings suggest that we may be able to prime students to maximize their own and other's experiences in active learning.

  11. Lab experiments are a major source of knowledge in the social sciences.

    PubMed

    Falk, Armin; Heckman, James J

    2009-10-23

    Laboratory experiments are a widely used methodology for advancing causal knowledge in the physical and life sciences. With the exception of psychology, the adoption of laboratory experiments has been much slower in the social sciences, although during the past two decades the use of lab experiments has accelerated. Nonetheless, there remains considerable resistance among social scientists who argue that lab experiments lack "realism" and generalizability. In this article, we discuss the advantages and limitations of laboratory social science experiments by comparing them to research based on nonexperimental data and to field experiments. We argue that many recent objections against lab experiments are misguided and that even more lab experiments should be conducted.

  12. Implementing Open Source Platform for Education Quality Enhancement in Primary Education: Indonesia Experience

    ERIC Educational Resources Information Center

    Kisworo, Marsudi Wahyu

    2016-01-01

    Information and Communication Technology (ICT)-supported learning using free and open source platform draws little attention as open source initiatives were focused in secondary or tertiary educations. This study investigates possibilities of ICT-supported learning using open source platform for primary educations. The data of this study is taken…

  13. Experience-based Auditory Predictions Modulate Brain Activity to Silence as do Real Sounds.

    PubMed

    Chouiter, Leila; Tzovara, Athina; Dieguez, Sebastian; Annoni, Jean-Marie; Magezi, David; De Lucia, Marzia; Spierer, Lucas

    2015-10-01

    Interactions between stimuli's acoustic features and experience-based internal models of the environment enable listeners to compensate for the disruptions in auditory streams that are regularly encountered in noisy environments. However, whether auditory gaps are filled in predictively or restored a posteriori remains unclear. The current lack of positive statistical evidence that internal models can actually shape brain activity as would real sounds precludes accepting predictive accounts of filling-in phenomenon. We investigated the neurophysiological effects of internal models by testing whether single-trial electrophysiological responses to omitted sounds in a rule-based sequence of tones with varying pitch could be decoded from the responses to real sounds and by analyzing the ERPs to the omissions with data-driven electrical neuroimaging methods. The decoding of the brain responses to different expected, but omitted, tones in both passive and active listening conditions was above chance based on the responses to the real sound in active listening conditions. Topographic ERP analyses and electrical source estimations revealed that, in the absence of any stimulation, experience-based internal models elicit an electrophysiological activity different from noise and that the temporal dynamics of this activity depend on attention. We further found that the expected change in pitch direction of omitted tones modulated the activity of left posterior temporal areas 140-200 msec after the onset of omissions. Collectively, our results indicate that, even in the absence of any stimulation, internal models modulate brain activity as do real sounds, indicating that auditory filling in can be accounted for by predictive activity.

  14. The fast neutron fluence and the activation detector activity calculations using the effective source method and the adjoint function

    SciTech Connect

    Hep, J.; Konecna, A.; Krysl, V.; Smutny, V.

    2011-07-01

    This paper describes the application of effective source in forward calculations and the adjoint method to the solution of fast neutron fluence and activation detector activities in the reactor pressure vessel (RPV) and RPV cavity of a VVER-440 reactor. Its objective is the demonstration of both methods on a practical task. The effective source method applies the Boltzmann transport operator to time integrated source data in order to obtain neutron fluence and detector activities. By weighting the source data by time dependent decay of the detector activity, the result of the calculation is the detector activity. Alternatively, if the weighting is uniform with respect to time, the result is the fluence. The approach works because of the inherent linearity of radiation transport in non-multiplying time-invariant media. Integrated in this way, the source data are referred to as the effective source. The effective source in the forward calculations method thereby enables the analyst to replace numerous intensive transport calculations with a single transport calculation in which the time dependence and magnitude of the source are correctly represented. In this work, the effective source method has been expanded slightly in the following way: neutron source data were performed with few group method calculation using the active core calculation code MOBY-DICK. The follow-up neutron transport calculation was performed using the neutron transport code TORT to perform multigroup calculations. For comparison, an alternative method of calculation has been used based upon adjoint functions of the Boltzmann transport equation. Calculation of the three-dimensional (3-D) adjoint function for each required computational outcome has been obtained using the deterministic code TORT and the cross section library BGL440. Adjoint functions appropriate to the required fast neutron flux density and neutron reaction rates have been calculated for several significant points within the RPV

  15. HerMES: disentangling active galactic nuclei and star formation in the radio source population

    NASA Astrophysics Data System (ADS)

    Rawlings, J. I.; Page, M. J.; Symeonidis, M.; Bock, J.; Cooray, A.; Farrah, D.; Guo, K.; Hatziminaoglou, E.; Ibar, E.; Oliver, S. J.; Roseboom, I. G.; Scott, Douglas; Seymour, N.; Vaccari, M.; Wardlow, J. L.

    2015-10-01

    We separate the extragalactic radio source population above ˜50 μJy into active galactic nuclei (AGN) and star-forming sources. The primary method of our approach is to fit the infrared spectral energy distributions (SEDs), constructed using Spitzer/IRAC (Infrared Array Camera) and Multiband Imaging Photometer for Spitzer (MIPS) and Herschel/SPIRE photometry, of 380 radio sources in the Extended Chandra Deep Field-South. From the fitted SEDs, we determine the relative AGN and star-forming contributions to their infrared emission. With the inclusion of other AGN diagnostics such as X-ray luminosity, Spitzer/IRAC colours, radio spectral index and the ratio of star-forming total infrared flux to k-corrected 1.4 GHz flux density, qIR, we determine whether the radio emission in these sources is powered by star formation or by an AGN. The majority of these radio sources (60 per cent) show the signature of an AGN at some wavelength. Of the sources with AGN signatures, 58 per cent are hybrid systems for which the radio emission is being powered by star formation. This implies that radio sources which have likely been selected on their star formation have a high AGN fraction. Below a 1.4 GHz flux density of 1 mJy, along with finding a strong contribution to the source counts from pure star-forming sources, we find that hybrid sources constitute 20-65 per cent of the sources. This result suggests that hybrid sources have a significant contribution, along with sources that do not host a detectable AGN, to the observed flattening of the source counts at ˜1 mJy for the extragalactic radio source population.

  16. Active extragalactic sources - Nearly simultaneous observations from 20 centimeters to 1400 A

    NASA Technical Reports Server (NTRS)

    Landau, R.; Golisch, B.; Jones, T. J.; Jones, T. W.; Pedelty, J.; Rudnick, L.; Sitko, M. L.; Kenney, J.; Roellig, T.; Salonen, E.

    1986-01-01

    IRAS, IUE, and ground-based optical, NIR, mm and submm, and radio observations obtained mainly on Apr. 9-23, 1983, are reported for 19 active extragalactic sources and eight control sources. The overall spectra of the compact active sources are shown to be well represented by continuous-curvature functions such as parabolas. The spectra are found to be consistent with models involving continuous particle injection (with synchrotron losses) or first-order Fermi acceleration (with escape and synchrotron losses), but not with models using relativistic Maxwellian electron distributions.

  17. An Active Global Attack Model for Sensor Source Location Privacy: Analysis and Countermeasures

    NASA Astrophysics Data System (ADS)

    Yang, Yi; Zhu, Sencun; Cao, Guohong; Laporta, Thomas

    Source locations of events are sensitive contextual information that needs to be protected in sensor networks. Previous work focuses on either an active local attacker that traces back to a real source in a hop-by-hop fashion, or a passive global attacker that eavesdrops/analyzes all network traffic to discover real sources. An active global attack model, which is more realistic and powerful than current ones, has not been studied yet. In this paper, we not only formalize this strong attack model, but also propose countermeasures against it.

  18. Active sand dunes are largest dust source in the Sahara Desert

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Atreyee

    2012-09-01

    Dried up lakebeds and playas in the Sahara Desert of North Africa are large sources of dust in the atmosphere. The Bodélé Depression at the southern edge of the Sahara Desert, for example, is the single largest source of dust in the world; on average, 100 dust storms a year originate from the Bodélé Depression. A new study by Crouvi et al., however, finds that active sand dunes could be even bigger sources of desert dust in the atmosphere. Atmospheric dust plays active roles in climate and biological processes in the ocean: It regulates heating at the surface of the Earth; modifies cloud properties that affect rainfall; and acts as the only source of iron, a critical nutrient for microorganisms in the ocean. Little is known about types of dust sources in the Sahara Desert, which alone accounts for more than 50% of the dust in the atmosphere.

  19. A novel source-drain follower for monolithic active pixel sensors

    NASA Astrophysics Data System (ADS)

    Gao, C.; Aglieri, G.; Hillemanns, H.; Huang, G.; Junique, A.; Keil, M.; Kim, D.; Kofarago, M.; Kugathasan, T.; Mager, M.; Marin Tobon, C. A.; Martinengo, P.; Mugnier, H.; Musa, L.; Lee, S.; Reidt, F.; Riedler, P.; Rousset, J.; Sielewicz, K. M.; Snoeys, W.; Sun, X.; Van Hoorne, J. W.; Yang, P.

    2016-09-01

    Monolithic active pixel sensors (MAPS) receive interest in tracking applications in high energy physics as they integrate sensor and readout electronics in one silicon die with potential for lower material budget and cost, and better performance. Source followers (SFs) are widely used for MAPS readout: they increase charge conversion gain 1/Ceff or decrease the effective sensing node capacitance Ceff because the follower action compensates part of the input capacitance. Charge conversion gain is critical for analog power consumption and therefore for material budget in tracking applications, and also has direct system impact. This paper presents a novel source-drain follower (SDF), where both source and drain follow the gate potential improving charge conversion gain. For the inner tracking system (ITS) upgrade of the ALICE experiment at CERN, low material budget is a primary requirement. The SDF circuit was studied as part of the effort to optimize the effective capacitance of the sensing node. The collection electrode, input transistor and routing metal all contribute to Ceff. Reverse sensor bias reduces the collection electrode capacitance. The novel SDF circuit eliminates the contribution of the input transistor to Ceff, reduces the routing contribution if additional shielding is introduced, provides a way to estimate the capacitance of the sensor itself, and has a voltage gain closer to unity than the standard SF. The SDF circuit has a somewhat larger area with a somewhat smaller bandwidth, but this is acceptable in most cases. A test chip, manufactured in a 180 nm CMOS image sensor process, implements small prototype pixel matrices in different flavors to compare the standard SF to the novel SF and to the novel SF with additional shielding. The effective sensing node capacitance was measured using a 55Fe source. Increasing reverse substrate bias from -1 V to -6 V reduces Ceff by 38% and the equivalent noise charge (ENC) by 22% for the standard SF. The SDF

  20. Gemvid, an open source, modular, automated activity recording system for rats using digital video

    PubMed Central

    Poirrier, Jean-Etienne; Poirrier, Laurent; Leprince, Pierre; Maquet, Pierre

    2006-01-01

    Background Measurement of locomotor activity is a valuable tool for analysing factors influencing behaviour and for investigating brain function. Several methods have been described in the literature for measuring the amount of animal movement but most are flawed or expensive. Here, we describe an open source, modular, low-cost, user-friendly, highly sensitive, non-invasive system that records all the movements of a rat in its cage. Methods Our activity monitoring system quantifies overall free movements of rodents without any markers, using a commercially available CCTV and a newly designed motion detection software developed on a GNU/Linux-operating computer. The operating principle is that the amount of overall movement of an object can be expressed by the difference in total area occupied by the object in two consecutive picture frames. The application is based on software modules that allow the system to be used in a high-throughput workflow. Documentation, example files, source code and binary files can be freely downloaded from the project website at . Results In a series of experiments with objects of pre-defined oscillation frequencies and movements, we documented the sensitivity, reproducibility and stability of our system. We also compared data obtained with our system and data obtained with an Actiwatch device. Finally, to validate the system, results obtained from the automated observation of 6 rats during 7 days in a regular light cycle are presented and are accompanied by a stability test. The validity of this system is further demonstrated through the observation of 2 rats in constant dark conditions that displayed the expected free running of their circadian rhythm. Conclusion The present study describes a system that relies on video frame differences to automatically quantify overall free movements of a rodent without any markers. It allows the monitoring of rats in their own environment for an extended period of time. By using a low-cost, open

  1. EEG and MEG: sensitivity to epileptic spike activity as function of source orientation and depth.

    PubMed

    Hunold, A; Funke, M E; Eichardt, R; Stenroos, M; Haueisen, J

    2016-07-01

    Simultaneous electroencephalography (EEG) and magnetoencephalography (MEG) recordings of neuronal activity from epileptic patients reveal situations in which either EEG or MEG or both modalities show visible interictal spikes. While different signal-to-noise ratios (SNRs) of the spikes in EEG and MEG have been reported, a quantitative relation of spike source orientation and depth as well as the background brain activity to the SNR has not been established. We investigated this quantitative relationship for both dipole and patch sources in an anatomically realistic cortex model. Altogether, 5600 dipole and 3300 patch sources were distributed on the segmented cortical surfaces of two volunteers. The sources were classified according to their quantified depths and orientations, ranging from 20 mm to 60 mm below the skin surface and radial and tangential, respectively. The source time-courses mimicked an interictal spike, and the simulated background activity emulated resting activity. Simulations were conducted with individual three-compartment boundary element models. The SNR was evaluated for 128 EEG, 102 MEG magnetometer, and 204 MEG gradiometer channels. For superficial dipole and superficial patch sources, EEG showed higher SNRs for dominantly radial orientations, and MEG showed higher values for dominantly tangential orientations. Gradiometers provided higher SNR than magnetometers for superficial sources, particularly for those with dominantly tangential orientations. The orientation dependent difference in SNR in EEG and MEG gradually changed as the sources were located deeper, where the interictal spikes generated higher SNRs in EEG compared to those in MEG for all source orientations. With deep sources, the SNRs in gradiometers and magnetometers were of the same order. To better detect spikes, both EEG and MEG should be used.

  2. The Source Physics Experiments (SPE): A Physics-Based Approach to Discriminate Low-Yield Nuclear Events (Invited)

    NASA Astrophysics Data System (ADS)

    Snelson, C. M.; Chipman, V.; White, R. L.; Emmitt, R.; Townsend, M.

    2013-12-01

    Discriminating low-yield nuclear explosions is one of the current challenges in the field of monitoring and verification. Work is currently underway in Nevada to address this challenge by conducting a series of experiments using a physics-based approach. This has been accomplished by using a multifaceted, multi-disciplinary approach that includes a range of activities, from characterizing the shallow subsurface to acquiring new explosion data both in the near field (< 100 m from the source) to the far field (> 100 m to 10 s km from the source). The Source Physics Experiment (SPE) is a collaborative project between National Security Technologies, LLC, Lawrence Livermore National Laboratory, Los Alamos National Laboratory, Sandia National Laboratories, the Defense Threat Reduction Agency, and the Air Force Technical Applications Center. The goal of the SPE is to understand the transition of seismic energy from the near field to the far field; to understand the development of S-waves in explosives sources; and to understand how anisotropy controls seismic energy transmission and partitioning. To fully explore these problems, the SPE test series includes tests in both simple and complex geology cases. The current series is being conducted in a highly fractured granite body. This location was chosen, in part, because it was the location of previous nuclear tests in the same rock body and because generally the geology has been well characterized. In addition to historic data, high-resolution seismic reflection, cross-hole tomography, core samples, LIDAR, hyperspectral, and fracture mapping data have been acquired to further characterize and detect changes after each of the shot across the test bed. The complex geology series includes 7 planned shots using conventional explosives in the same shot hole surrounded by Continuous Reflectometry for Radius vs. Time Experiment (CORRTEX), Time of Arrival, Velocity of Detonation, down-hole accelerometers, surface accelerometers

  3. Agent-based power sharing scheme for active hybrid power sources

    NASA Astrophysics Data System (ADS)

    Jiang, Zhenhua

    The active hybridization technique provides an effective approach to combining the best properties of a heterogeneous set of power sources to achieve higher energy density, power density and fuel efficiency. Active hybrid power sources can be used to power hybrid electric vehicles with selected combinations of internal combustion engines, fuel cells, batteries, and/or supercapacitors. They can be deployed in all-electric ships to build a distributed electric power system. They can also be used in a bulk power system to construct an autonomous distributed energy system. An important aspect in designing an active hybrid power source is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. This paper presents an agent-based power sharing scheme for active hybrid power sources. To demonstrate the effectiveness of the proposed agent-based power sharing scheme, simulation studies are performed for a hybrid power source that can be used in a solar car as the main propulsion power module. Simulation results clearly indicate that the agent-based control framework is effective to coordinate the various energy sources and manage the power/voltage profiles.

  4. An Overview of the Source Physics Experiment at the Nevada National Security Site (SPE-N)

    SciTech Connect

    Snelson, C. M., Chipman, V. D., White, R. L., Emmitt, R. F., Townsend, M. J., Barker, D., Lee, P.

    2012-07-11

    Understanding the changes in seismic energy as it travels from the near field to the far field is the ultimate goal in monitoring for explosive events of interest. This requires a clear understanding of explosion phenomenology as it relates to seismic, infrasound, and acoustic signals. Although there has been much progress in modeling these phenomena, this has been primarily based in the empirical realm. As a result, the logical next step in advancing the seismic monitoring capability of the United States is to conduct field tests that can expand the predictive capability of the physics-based modeling currently under development. The Source Physics Experiment at the Nevada National Security Site (SPE-N) is the first step in this endeavor to link the empirically based with the physics-based modeling. This is a collaborative project between National Security Technologies (NSTec), Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), the Defense Threat Reduction Agency (DTRA), and the Air Force Technical Applications Center (AFTAC). The test series require both the simple and complex cases to fully characterize the problem, which is to understand the transition of seismic energy from the near field to the far field; to understand the development of S-waves in explosives sources; and how anisotropy controls seismic energy transmission and partitioning. The current series is being conducted in a granite body called the Climax Stock. This location was chosen for several reasons, including the fairly homogenous granite; the location of previous nuclear tests in the same rock body; and generally the geology has been well characterized. The simple geology series is planned for 7 shots using conventional explosives in the same shot hole surrounded by Continuous Reflectometry for Radius vs. Time Experiment (CORRTEX), Time of Arrival (TOA), Velocity of Detonation (VOD), down-hole accelerometers, surface

  5. The Source Physics Experiments (SPE) at the Nevada National Security Site (NNSS): An Overview

    NASA Astrophysics Data System (ADS)

    Snelson, C. M.; Chipman, V.; White, R. L.; Emmitt, R.; Townsend, M.; Barker, D.; Lee, P.

    2012-12-01

    Understanding the changes in seismic energy as it travels from the near field to the far field is the ultimate goal in monitoring for explosive events of interest. This requires a clear understanding of explosion phenomenology as it relates to seismic, infrasound, and acoustic signals. Although there has been much progress in modeling these phenomena, this has been primarily based in the empirical realm. As a result, the logical next step in advancing the seismic monitoring capability of the United States is to conduct field tests that can expand the predictive capability of the physics-based modeling currently under development. The Source Physics Experiment at the Nevada National Security Site (SPE) is the first step in this endeavor to link the empirically based with the physics-based modeling. This is a collaborative project between National Security Technologies (NSTec), Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), the Defense Threat Reduction Agency (DTRA), and the Air Force Technical Applications Center (AFTAC). The test series require both the simple and complex cases to fully characterize the problem, which is to understand the transition of seismic energy from the near field to the far field; to understand the development of S-waves in explosives sources; and how anisotropy controls seismic energy transmission and partitioning. The current series is being conducted in a granite body called the Climax Stock. This location was chosen for several reasons, including the fairly homogenous granite; the location of previous nuclear tests in the same rock body; and generally the geology has been well characterized. The simple geology series is planned for 7 shots using conventional explosives in the same shot hole surrounded by Continuous Reflectometry for Radius vs. Time Experiment (CORRTEX), Time of Arrival (TOA), Velocity of Detonation (VOD), down-hole accelerometers, surface

  6. Sustaining an Online, Shared Community Resource for Models, Robust Open source Software Tools and Data for Volcanology - the Vhub Experience

    NASA Astrophysics Data System (ADS)

    Patra, A. K.; Valentine, G. A.; Bursik, M. I.; Connor, C.; Connor, L.; Jones, M.; Simakov, N.; Aghakhani, H.; Jones-Ivey, R.; Kosar, T.; Zhang, B.

    2015-12-01

    Over the last 5 years we have created a community collaboratory Vhub.org [Palma et al, J. App. Volc. 3:2 doi:10.1186/2191-5040-3-2] as a place to find volcanology-related resources, and a venue for users to disseminate tools, teaching resources, data, and an online platform to support collaborative efforts. As the community (current active users > 6000 from an estimated community of comparable size) embeds the tools in the collaboratory into educational and research workflows it became imperative to: a) redesign tools into robust, open source reusable software for online and offline usage/enhancement; b) share large datasets with remote collaborators and other users seamlessly with security; c) support complex workflows for uncertainty analysis, validation and verification and data assimilation with large data. The focus on tool development/redevelopment has been twofold - firstly to use best practices in software engineering and new hardware like multi-core and graphic processing units. Secondly we wish to enhance capabilities to support inverse modeling, uncertainty quantification using large ensembles and design of experiments, calibration, validation. Among software engineering practices we practice are open source facilitating community contributions, modularity and reusability. Our initial targets are four popular tools on Vhub - TITAN2D, TEPHRA2, PUFF and LAVA. Use of tools like these requires many observation driven data sets e.g. digital elevation models of topography, satellite imagery, field observations on deposits etc. These data are often maintained in private repositories that are privately shared by "sneaker-net". As a partial solution to this we tested mechanisms using irods software for online sharing of private data with public metadata and access limits. Finally, we adapted use of workflow engines (e.g. Pegasus) to support the complex data and computing workflows needed for usage like uncertainty quantification for hazard analysis using physical

  7. Eliciting Metacognitive Experiences and Reflection in a Year 11 Chemistry Classroom: An Activity Theory Perspective

    NASA Astrophysics Data System (ADS)

    Thomas, Gregory P.; McRobbie, Campbell J.

    2013-06-01

    Concerns regarding students' learning and reasoning in chemistry classrooms are well documented. Students' reasoning in chemistry should be characterized by conscious consideration of chemical phenomenon from laboratory work at macroscopic, molecular/sub-micro and symbolic levels. Further, students should develop metacognition in relation to such ways of reasoning about chemistry phenomena. Classroom change eliciting metacognitive experiences and metacognitive reflection is necessary to shift entrenched views of teaching and learning in students. In this study, Activity Theory is used as the framework for interpreting changes to the rules/customs and tools of the activity systems of two different classes of students taught by the same teacher, Frances, who was teaching chemical equilibrium to those classes in consecutive years. An interpretive methodology involving multiple data sources was employed. Frances explicitly changed her pedagogy in the second year to direct students attention to increasingly consider chemical phenomena at the molecular/sub-micro level. Additionally, she asked students not to use the textbook until toward the end of the equilibrium unit and sought to engage them in using their prior knowledge of chemistry to understand their observations from experiments. Frances' changed pedagogy elicited metacognitive experiences and reflection in students and challenged them to reconsider their metacognitive beliefs about learning chemistry and how it might be achieved. While teacher change is essential for science education reform, students are not passive players in change efforts and they need to be convinced of the viability of teacher pedagogical change in the context of their goals, intentions, and beliefs.

  8. Geology of the Source Physics Experiment Site, Climax Stock, Nevada National Security Site

    SciTech Connect

    Townsend, M., Prothro, L. B., Obi, C.

    2012-03-15

    A test bed for a series of chemical explosives tests known as Source Physics Experiments (SPE) was constructed in granitic rock of the Climax stock, in northern Yucca Flat at the Nevada National Security Site in 2010-2011. These tests are sponsored by the U.S. Department of Energy, National Nuclear Security Administration's National Center for Nuclear Security. The test series is designed to study the generation and propagation of seismic waves, and will provide data that will improve the predictive capability of calculational models for detecting and characterizing underground explosions. Abundant geologic data are available for the area, primarily as a result of studies performed in conjunction with the three underground nuclear tests conducted in the Climax granite in the 1960s and a few later studies of various types. The SPE test bed was constructed at an elevation of approximately 1,524 meters (m), and consists of a 91.4-centimeter (cm) diameter source hole at its center, surrounded by two rings of three 20.3-cm diameter instrument holes. The inner ring of holes is positioned 10 m away from the source hole, and the outer ring of holes is positioned 20 m from the source hole. An initial 160-m deep core hole was drilled at the location of the source hole that provided information on the geology of the site and rock samples for later laboratory testing. A suite of geophysical logs was run in the core hole and all six instruments holes to obtain matrix and fracture properties. Detailed information on the character and density of fractures encountered was obtained from the borehole image logs run in the holes. A total of 2,488 fractures were identified in the seven boreholes, and these were ranked into six categories (0 through 5) on the basis of their degree of openness and continuity. The analysis presented here considered only the higher-ranked fractures (ranks 2 through 5), of which there were 1,215 (approximately 49 percent of all fractures identified from

  9. Mixed carbon sources for nitrate reduction in activated sludge-identification of bacteria and process activity studies.

    PubMed

    Hagman, M; Nielsen, J L; Nielsen, P H; Jansen, J la C

    2008-03-01

    Mixtures of methanol and acetate as carbon source were investigated in order to determine their capacity to enhance denitrification and for analysis of the microbial composition and carbon degradation activity in activated sludge from wastewater treatment plants. Laboratory batch reactors at 20 degrees C were used for nitrate uptake rate (NUR) measurements in order to investigate the anoxic activity, while single and mixed carbon substrates were added to activated sludge. Microautoradiography (MAR) in combination with fluorescence in situ hybridisation (FISH) were applied for microbial analysis during exposure to different carbon sources. The NUR increased with additions of a mixture of acetate and methanol compared with additions of a single carbon source. MAR-FISH measurements demonstrated that the probe-defined group of Azoarcus was the main group of bacteria utilising acetate and the only active group utilising methanol under anoxic conditions. The present study indicated an improved denitrification potential by additions of a mixed carbon source compared with commonly used single-carbon additions. It is also established that Azoarcus bacteria are involved in the degradation of both acetate and methanol in the anoxic activated sludge.

  10. Edge effect modeling and experiments on active lap processing.

    PubMed

    Liu, Haitao; Wu, Fan; Zeng, Zhige; Fan, Bin; Wan, Yongjian

    2014-05-05

    Edge effect is regarded as one of the most difficult technical issues for fabricating large primary mirrors, especially for large polishing tools. Computer controlled active lap (CCAL) uses a large size pad (e.g., 1/3 to 1/5 workpiece diameters) to grind and polish the primary mirror. Edge effect also exists in the CCAL process in our previous fabrication. In this paper the material removal rules when edge effects happen (i.e. edge tool influence functions (TIFs)) are obtained through experiments, which are carried out on a Φ1090-mm circular flat mirror with a 375-mm-diameter lap. Two methods are proposed to model the edge TIFs for CCAL. One is adopting the pressure distribution which is calculated based on the finite element analysis method. The other is building up a parametric equivalent pressure model to fit the removed material curve directly. Experimental results show that these two methods both effectively model the edge TIF of CCAL.

  11. Active Reading Experience Questionnaire: Development and Validation of an Instrument for Studying Active Reading Activities

    ERIC Educational Resources Information Center

    Palilonis, Jennifer; Butler, Darrell

    2015-01-01

    The increasing adoption of mobile platforms and digital textbooks in university classrooms continues to have a profound impact on higher education. Advocates believe that providing students digital textbooks with built-in annotation features and interactive study tools will improve learning by facilitating active reading, a task essential to…

  12. Ion source for tests of ion behavior in the Karlsruhe tritium neutrino experiment beam line

    SciTech Connect

    Lukic, S.; Bornschein, B.; Drexlin, G.; Glueck, F.; Kazachenko, O.; Zoll, M. C. R.; Schoeppner, M.; Weinheimer, Ch.

    2011-01-15

    An electron-impact ion source based on photoelectron emission was developed for ionization of gases at pressures below 10{sup -4} mbar in an axial magnetic field in the order of 5 T. The ion source applies only dc fields, which makes it suitable for use in the presence of equipment sensitive to radio-frequency (RF) fields. The ion source was successfully tested under varying conditions regarding pressure, magnetic field, and magnetic-field gradient, and the results were studied with the help of simulations. The processes in the ion source are well understood, and possibilities for further optimization of generated ion currents are clarified.

  13. Simulation and beamline experiments for the superconducting electron cyclotron resonance ion source VENUS

    SciTech Connect

    Todd, Damon S.; Leitner, Daniela; Lyneis, Claude M.; Grote, David P.

    2008-02-15

    The particle-in-cell code WARP has been enhanced to incorporate both two- and three-dimensional sheath extraction models giving WARP the capability of simulating entire ion beam transport systems including the extraction of beams from plasma sources. In this article, we describe a method of producing initial ion distributions for plasma extraction simulations in electron cyclotron resonance (ECR) ion sources based on experimentally measured sputtering on the source biased disk. Using this initialization method, we present preliminary results for extraction and transport simulations of an oxygen beam and compare them with experimental beam imaging on a quartz viewing plate for the superconducting ECR ion source VENUS.

  14. Data Release Report for Source Physics Experiments 2 and 3 (SPE-2 and SPE-3) Nevada National Security Site

    SciTech Connect

    Townsend, Margaret; Obi, Curtis

    2015-01-26

    The second Source Physics Experiment shot (SPE-2) was conducted in Nevada on October 25, 2011, at 1900:00.011623 Greenwich Mean Time (GMT). The explosive source was 997 kilograms (kg) trinitrotoluene (TNT) equivalent of sensitized heavy ammonium fuel oil (SHANFO) detonated at a depth of 45.7 meters (m). The third Source Physics Experiment shot (SPE-3) was conducted in Nevada on July 24, 2012, at 1800:00.44835 GMT. The explosive source was 905 kg TNT equivalent of SHANFO detonated at a depth of 45.8 m. Both shots were recorded by an extensive set of instrumentation that includes sensors both at near-field (less than 100 m) and far-field (100 m or greater) distances. The near-field instruments consisted of three-component accelerometers deployed in boreholes at 15, 46, and 55 m depths around the shot and a set of single-component vertical accelerometers on the surface. The far-field network was composed of a variety of seismic and acoustic sensors, including short-period geophones, broadband seismometers, three-component accelerometers, and rotational seismometers at distances of 100 m to 25 kilometers. This report coincides with the release of these data for analysts and organizations that are not participants in this program. This report describes the second and third Source Physics Experiment shots and the various types of near-field and far-field data that are available.

  15. Multiphase transport simulation and venting experiments to identify NAPL source in vadose zone at a site contaminated with chlorinated solvents

    NASA Astrophysics Data System (ADS)

    Joun, W.; Lee, K.

    2013-12-01

    In many countries, groundwater is threatened by contamination from Non-Aqueous Phase Liquids such as chlorinated solvents (e.g. TCE). Existing as a residual or trapped source in the unsaturated zone, NAPLs remain in a continuous contamination source to groundwater even after groundwater itself was remediated because the residual NAPL source could be dissolved into the groundwater intermittently. In this study, 1-D and 2-D experiments were conducted. For 1-D experiment, a column (1 m) packed with well-sorted sand was used for developing the hydraulic properties in VOC transport. In 2-D experiment, hydraulic and contaminant properties in unsaturated condition were investigated including gas-phase concentration of a volatile organic compound (trichloroethylene, TCE) originated from residual or trapped NAPLs with different distances between an extraction well and source point, with different extraction rates and with different extraction intervals. While extracting air from the sand-tank (50 x 30 x 5 cm), temperature, humidity and pressure data were compiled with logging sensors. One and two-dimensional STOMP (Subsurface Transport Over Multiple Phases) simulator were used to simulate the experimental conditions. The experimental and simulation results can be used to estimate distances from extraction wells to source locations of residual NAPLs.

  16. Exterior optical cloaking and illusions by using active sources: A boundary element perspective

    NASA Astrophysics Data System (ADS)

    Zheng, H. H.; Xiao, J. J.; Lai, Y.; Chan, C. T.

    2010-05-01

    Recently, it was demonstrated that active sources can be used to cloak any objects that lie outside the cloaking devices [F. Guevara Vasquez, G. W. Milton, and D. Onofrei, Phys. Rev. Lett. 103, 073901 (2009)]. Here, we propose that active sources can create illusion effects so that an object outside the cloaking device can be made to look like another object. Invisibility is a special case in which the concealed object is transformed to a volume of air. From a boundary element perspective, we show that active sources can create a nearly “silent” domain which can conceal any objects inside and at the same time make the whole system look like an illusion of our choice outside a virtual boundary. The boundary element method gives the fields and field gradients, which can be related to monopoles and dipoles, on continuous curves which define the boundary of the active devices. Both the cloaking and illusion effects are confirmed by numerical simulations.

  17. Auditory Selective Attention Reveals Preparatory Activity in Different Cortical Regions for Selection Based on Source Location and Source Pitch

    PubMed Central

    Lee, Adrian K. C.; Rajaram, Siddharth; Xia, Jing; Bharadwaj, Hari; Larson, Eric; Hämäläinen, Matti S.; Shinn-Cunningham, Barbara G.

    2012-01-01

    In order to extract information in a rich environment, we focus on different features that allow us to direct attention to whatever source is of interest. The cortical network deployed during spatial attention, especially in vision, is well characterized. For example, visuospatial attention engages a frontoparietal network including the frontal eye fields (FEFs), which modulate activity in visual sensory areas to enhance the representation of an attended visual object. However, relatively little is known about the neural circuitry controlling attention directed to non-spatial features, or to auditory objects or features (either spatial or non-spatial). Here, using combined magnetoencephalography (MEG) and anatomical information obtained from MRI, we contrasted cortical activity when observers attended to different auditory features given the same acoustic mixture of two simultaneous spoken digits. Leveraging the fine temporal resolution of MEG, we establish that activity in left FEF is enhanced both prior to and throughout the auditory stimulus when listeners direct auditory attention to target location compared to when they focus on target pitch. In contrast, activity in the left posterior superior temporal sulcus (STS), a region previously associated with auditory pitch categorization, is greater when listeners direct attention to target pitch rather than target location. This differential enhancement is only significant after observers are instructed which cue to attend, but before the acoustic stimuli begin. We therefore argue that left FEF participates more strongly in directing auditory spatial attention, while the left STS aids auditory object selection based on the non-spatial acoustic feature of pitch. PMID:23335874

  18. How Students Describe the Sources of Their Emotional and Motivational Experiences during the Learning Process: A Qualitative Approach

    ERIC Educational Resources Information Center

    Jarvenoja, Hanna; Jarvela, Sanna

    2005-01-01

    The aim of the study reported in this paper was to consider the sources of emotional and motivational experiences of secondary school students (N=18), 12-15 years old, during computer-supported collaborative learning projects. We chose the concept of volition to frame the analysis of the various kinds of descriptions the students give of their…

  19. Are cells from a snowman realistic? Cryopreserved tissues as a source for single-cell RNA-sequencing experiments.

    PubMed

    Vieira Braga, Felipe A; Teichmann, Sarah A; Stubbington, Michael J T

    2017-03-24

    A recently published study in Genome Biology shows that cells isolated from cryopreserved tissues are a reliable source of genetic material for single-cell RNA-sequencing experiments.Please see related Method article: http://genomebiology.biomedcentral.com/articles/10.1186/s13059-017-1171-9.

  20. Disposal Process for High Activity Sources by a University through the U.S. Dept. of Energy's Off-Site Source Recovery Project - 12076

    SciTech Connect

    Abraham, James P.; Brandl, Alexander

    2012-07-01

    Sealed radioactive sources are used in a wide variety of applications by a large number of license holders in the Unites States. Applications range from low-activity calibration sources to high-activity irradiators for engineering, research, or medical purposes. This paper describes and evaluates the safety and security measures in place for disused sealed sources, in particular of high activity sealed sources at the end of their operational life-time. The technical, radiation protection, and financial challenges for licensees and the Competent Authorities are reviewed from the point of view of the license holder. As an example, the waste management processes and the chain of custody for disused research irradiator sources are followed from extraction from the irradiator facility to the source disposal or recycling contractor. Possible safety and security concern in the waste disposal process are investigated in order to identify improvement potential for radiation protection or source security. Two shipments of disused sealed sources from Colorado State University (CSU) have been conducted through the CSU Radiation Control Office (RCO) in the last two years, with a third shipment expected to be completed by the end of November 2011. Two of the sources shipped are considered 'high' activity and exceed the U.S. NRC limits requiring increased controls for security purposes. Three sources were shipped in 2009 and ten more are expected in 2011. A total activity of 117.3 GBq was shipped in 2009. Nine sources were recently shipped in October 2011 through a third party waste broker where the total activity was 96.34 GBq. The last source is scheduled for shipment no later than 30 November 2011 and contains an activity of 399.96 GBq. Radiation waste disposal of high activity sources in large shields with unknown manufacturers, serial numbers, or model numbers is an arduous process requiring multiple contacts with various state and federal agencies. DOE's OSRP has made it

  1. Experimental evidence that microbial activity lowers the albedo of glacier surfaces: the cryoconite casserole experiment.

    NASA Astrophysics Data System (ADS)

    Musilova, M.; Tranter, M.; Takeuchi, N.; Anesio, A. M.

    2014-12-01

    Darkened glacier and ice sheet surfaces have lower albedos, absorb more solar radiation and consequently melt more rapidly. The increase in glacier surface darkening is an important positive feedback to warming global temperatures, leading to ever growing world-wide ice mass loss. Most studies focus primarily on glacial albedo darkening caused by the physical properties of snow and ice surfaces, and the deposition of dark impurities on glaciers. To date, however, the important effects of biological activity have not been included in most albedo reduction models. This study provides the first experimental evidence that microbial activity can significantly decrease the albedo of glacier surfaces. An original laboratory experiment, the cryoconite casserole, was designed to test the microbial darkening of glacier surface debris (cryoconite) under simulated Greenlandic summer conditions. It was found that minor fertilisation of the cryoconite (at nutrient concentrations typical of glacial ice melt) stimulated extensive microbial activity. Microbes intensified their organic carbon fixation and even mined phosphorous out of the glacier surface sediment. Furthermore, the microbial organic carbon production, accumulation and transformation caused the glacial debris to darken further by 17.3% reflectivity (albedo analogue). These experiments are consistent with the hypothesis that enhanced fertilisation by anthropogenic inputs results in substantial amounts of organic carbon fixation, debris darkening and ultimately to a considerable decrease in the ice albedo of glacier surfaces on global scales. The sizeable amounts of microbially produced glacier surface organic matter and nutrients can thus be a vital source of bioavailable nutrients for subglacial and downstream environments.

  2. Modeling the Effect of External Carbon Source Addition under Different Electron Acceptor Conditions in Biological Nutrient Removal Activated Sludge Systems.

    PubMed

    Hu, Xiang; Wisniewski, Kamil; Czerwionka, Krzysztof; Zhou, Qi; Xie, Li; Makinia, Jacek

    2016-02-16

    The aim of this study was to expand the International Water Association Activated Sludge Model No. 2d (ASM2d) to predict the aerobic/anoxic behavior of polyphosphate accumulating organisms (PAOs) and "ordinary" heterotrophs in the presence of different external carbon sources and electron acceptors. The following new aspects were considered: (1) a new type of the readily biodegradable substrate, not available for the anaerobic activity of PAOs, (2) nitrite as an electron acceptor, and (3) acclimation of "ordinary" heterotrophs to the new external substrate via enzyme synthesis. The expanded model incorporated 30 new or modified process rate equations. The model was evaluated against data from several, especially designed laboratory experiments which focused on the combined effects of different types of external carbon sources (acetate, ethanol and fusel oil) and electron acceptors (dissolved oxygen, nitrate and nitrite) on the behavior of PAOs and "ordinary" heterotrophs. With the proposed expansions, it was possible to improve some deficiencies of the ASM2d in predicting the behavior of biological nutrient removal (BNR) systems with the addition of external carbon sources, including the effect of acclimation to the new carbon source.

  3. Non-Traditional Sources of Revenue for High Schools: South Dakota's Experience in the Private Sector.

    ERIC Educational Resources Information Center

    Garnos, Michael L.

    A survey of superintendents and principals in 91 percent of South Dakota school districts examined the extent and nature of nontraditional funding acquired by high schools, and administrator attitudes toward this funding. Sources of funding were categorized as donor sources (cash or other donations from individuals or organizations); enterprise…

  4. Contextualized perceptions of movement as a source of expanded insight: People with multiple sclerosis' experience with physiotherapy.

    PubMed

    Normann, Britt; Sørgaard, Knut W; Salvesen, Rolf; Moe, Siri

    2013-01-01

    The hospitals' outpatient clinics for people with multiple sclerosis (PwMS) are important in the health care. Research regarding physiotherapy in such clinics is limited. The purpose was to investigate how PwMS perceive movement during single sessions of physiotherapy in a hospital's outpatient clinic, and what do these experiences mean for the patient's insight into their movement disturbances? Qualitative research interviews were performed with a purposive sample of 12 PwMS and supplemented with seven videotaped sessions. Content analysis was performed. The results indicate that contextualized perceptions of movement appear to be an essential source for PwMS to gain expanded insight with regard to their individual movement disturbances regardless of their ambulatory status. The contextualization implies that perceptions of movement are integrated with the physiotherapist's explanations regarding optimizing gait and balance or other activities of daily life. Perceptions of improvement in body part movement and/or functional activities are vital to enhancing their understanding of their individual movement disorders, and they may provide expanded insight regarding future possibilities and limitations involving everyday tasks. The implementation of movements, which transforms the perceived improvement into self-assisted exercises, appeared to be meaningful. Contextualized perceptions of improvements in movement may strengthen the person's sense of ownership and sense of agency and thus promote autonomy and self-encouragement. The findings underpin the importance of contextualized perceptions of movement based on exploration of potential for change, as an integrated part of information and communication in the health care for PwMS. Further investigations are necessary to deepen our knowledge.

  5. Undergraduate Laboratory Experiment Facilitating Active Learning of Concepts in Transport Phenomena: Experiment with a Subliming Solid

    ERIC Educational Resources Information Center

    Utgikar, Vivek P.

    2015-01-01

    An experiment based on the sublimation of a solid was introduced in the undergraduate Transport Phenomena course. The experiment required the students to devise their own apparatus and measurement techniques. The theoretical basis, assignment of the experiment, experimental results, and student/instructor observations are described in this paper.…

  6. Aerosol Composition, Chemistry, and Source Characterization during the 2008 VOCALS Experiment

    NASA Astrophysics Data System (ADS)

    Lee, Y.; Springston, S.; Jayne, J. T.; Wang, J.; Senum, G.; Hubbe, J.; Alexander, L.; Brioude, J.; Spak, S.; Mena-Carrasco, M.; Kleinman, L. I.; Daum, P. H.

    2009-12-01

    Chemical composition of fine aerosol particles over the northern Chilean coastal waters was determined on board the US DOE G-1 aircraft during the VOCALS (VAMOS Ocean-Cloud-Atmosphere-Land Study) field experiment between October 16 and November 15, 2008. Chemical species determined included SO42-, NO3-, NH4+, and total organics (Org) using an Aerodyne Aerosol Mass Spectrometer, and SO42-, NO3-, NH4+, Na+, Cl-, CH3SO3-, Mg2+, Ca2+, and K+ using a particle-into-liquid sampler-ion chromatography technique. The results show the marine boundary layer (MBL) aerosol mass was dominated by non-sea-salt SO42- followed by Na+, Cl-, Org, NO3-, and NH4+, in decreasing importance; CH3SO3-, Ca2+, and K+ rarely exceeded their respective limits of detection. The SO42- aerosols were strongly acidic as the equivalent NH4+ to SO42- ratio was only ~0.25 on average. NaCl particles, presumably of sea-salt origin, showed chloride deficits but retained Cl- typically more than half the equivalency of Na+, and are believed to be externally mixed with the acidic sulfate aerosols. Nitrate was observed only on sea-salt particles, consistent with adsorption of HNO3 on non-acidic sea-salt aerosols, responsible partly for the Cl- deficit. Dust particles appeared to play a minor role judging from the small volume differences between that derived from the observed mass concentrations and that calculated based on particle size distributions. Because SO42- concentrations in the study domain were substantial (~0.5 - ~3 μg/m3) with a strong gradient (highest near the shore decreasing with distance from land), and the ocean-emitted dimethylsulfide and its unique oxidation product, CH3SO3-, were very low (i.e., ≤ 40 parts per trillion and <0.05 μg/m3, respectively), the observed SO42- aerosols are believed to be primarily of terrestrial origin. Back trajectory calculations indicate sulfur emissions from smelters and power plants along coastal regions of Peru and Chile are the main sources of these SO4

  7. The VSOP 5 GHz Active Galactic Nucleus Survey. V. Imaging Results for the Remaining 140 Sources

    NASA Astrophysics Data System (ADS)

    Dodson, R.; Fomalont, E. B.; Wiik, K.; Horiuchi, S.; Hirabayashi, H.; Edwards, P. G.; Murata, Y.; Asaki, Y.; Moellenbrock, G. A.; Scott, W. K.; Taylor, A. R.; Gurvits, L. I.; Paragi, Z.; Frey, S.; Shen, Z.-Q.; Lovell, J. E. J.; Tingay, S. J.; Rioja, M. J.; Fodor, S.; Lister, M. L.; Mosoni, L.; Coldwell, G.; Piner, B. G.; Yang, J.

    2008-04-01

    In 1997 February, the Japanese radio astronomy satellite HALCA was launched to provide the space-bourne element for the VLBI Space Observatory Program (VSOP) mission. Approximately 25% of the mission time was dedicated to the VSOP survey of bright compact active galactic nuclei (AGNs) at 5 GHz. This paper, the fifth in the series, presents images and models for the remaining 140 sources not included in the third paper in the series, which contained 102 sources. For most sources, the plots of the (u,v) coverage, the visibility amplitude versus (u,v) distance, and the high-resolution image are presented. Model fit parameters to the major radio components are determined, and the brightness temperature of the core component for each source is calculated. The brightness temperature distributions for all of the sources in the VSOP AGN survey are discussed.

  8. Difficulties in Estimating the Physical Parameters of Compact Radio Sources in Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Artyukh, V. S.

    2016-12-01

    The various factors influencing estimates of the physical parameters of compact radio sources in active galactic nuclei (AGN) using a methods based on uniform models of synchrotron radiation sources are analyzed. It is found that the form of the relativistic electron energy density distribution as a function of magnetic energy density (Ee-EH) in the radio sources is determined by the shape of the electron energy spectrum. It is shown that the very large observed deviations of the estimated energies of the field and relativistic particles from equipartition are mainly caused by nonuniformity of the radio sources. In order to obtain correct estimates of the physical parameters of nonuniform radio sources, it is necessary to know their angular sizes at low frequencies (in the opaque region) and their Doppler factors.

  9. Evidence for Infrared-faint Radio Sources as z > 1 Radio-loud Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Huynh, Minh T.; Norris, Ray P.; Siana, Brian; Middelberg, Enno

    2010-02-01

    Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey which have no observable mid-infrared counterpart in the Spitzer Wide-area Infrared Extragalactic (SWIRE) survey. The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6-70 μm) from a number of Legacy surveys. We report the detections of two IFRS sources in IRAC images. The non-detection of two other IFRSs allows us to constrain the source type. Detailed modeling of the spectral energy distribution of these objects shows that they are consistent with high-redshift (z >~ 1) active galactic nuclei.

  10. Simulation and beam line experiments for the superconducting ECRion source VENUS

    SciTech Connect

    Todd, Damon S.; Leitner, Daniela; Grote, David P.; Lyneis, ClaudeM.

    2007-09-10

    The particle-in-cell code Warp has been enhanced toincorporate both two- and three-dimensional sheath extraction modelsgiving Warp the capability of simulating entire ion beam transportsystems including the extraction of beams from plasma sources. In thisarticle we describe a method of producing initial ion distributions forplasma extraction simulations in electron cyclotron resonance (ECR) ionsources based on experimentally measured sputtering on the source biaseddisc. Using this initialization method, we present preliminary resultsfor extraction and transport simulations of an oxygen beam and comparethem with experimental beam imaging on a quartz viewing plate for thesuperconducting ECR ion source VENUS.

  11. A laser-induced repetitive fast neutron source applied for gold activation analysis

    SciTech Connect

    Lee, Sungman; Park, Sangsoon; Lee, Kitae; Cha, Hyungki

    2012-12-15

    A laser-induced repetitively operated fast neutron source was developed for applications in laser-driven nuclear physics research. The developed neutron source, which has a neutron yield of approximately 4 Multiplication-Sign 10{sup 5} n/pulse and can be operated up to a pulse repetition rate of 10 Hz, was applied for a gold activation analysis. Relatively strong delayed gamma spectra of the activated gold were measured at 333 keV and 355 keV, and proved the possibility of the neutron source for activation analyses. In addition, the nuclear reactions responsible for the measured gamma spectra of gold were elucidated by the 14 MeV fast neutrons resulting from the D(t,n)He{sup 4} nuclear reaction, for which the required tritium originated from the primary fusion reaction, D(d,p)T{sup 3}.

  12. Geologic Assessment of the Damage Zone from the Second Test at Source Physics Experiment-Nevada (SPE-N)

    SciTech Connect

    Townsend, M. J.; Huckins-Gang, H. E.; Prothro, L. B.; Reed, D. N.

    2012-12-01

    The National Center for Nuclear Security, established by the U.S. Department of Energy, National Nuclear Security Administration (NNSA), is conducting a series of explosive tests at the Nevada National Security Site that are designed to increase the understanding of certain basic physical phenomena associated with underground explosions. These tests will aid in developing technologies that might be used to detect underground nuclear explosions in support of verification activities for the Comprehensive Nuclear-Test-Ban Treaty. The initial project is a series of explosive tests, known collectively as the Source Physics Experiment-Nevada (SPE-N), being conducted in granitic rocks. The SPE-N test series is designed to study the generation and propagation of seismic waves. The results will help advance the seismic monitoring capability of the United States by improving the predictive capability of physics-based modeling of explosive phenomena. The first SPE N (SPE-N-1) test was conducted in May 2011, using 100 kg of explosives at the depth of 54.9 m in the U 15n source hole. SPE-N-2 was conducted in October 2011, using 1,000 kg of explosives at the depth of 45.7 m in the same source hole. The SPE-N-3 test was conducted in the same source hole in July 2012, using the same amount and type of explosive as for SPE-N-2, and at the same depth as SPE-N-2, within the damage zone created by the SPE-N-2 explosion to investigate damage effects on seismic wave propagation. Following the SPE-N-2 shot and prior to the SPE-N-3 shot, the core hole U-15n#10 was drilled at an angle from the surface to intercept the SPE-N-2 shot point location to obtain information necessary to characterize the damage zone. The objective was to determine the position of the damage zone near the shot point, at least on the northeast, where the core hole penetrated it, and obtain information on the properties of the damaged medium. Geologic characterization of the post-SPE-N-2 core hole included

  13. Reflection processing of the large-N seismic data from the Source Physics Experiment (SPE)

    SciTech Connect

    Paschall, Olivia C.

    2016-07-18

    The purpose of the SPE is to develop a more physics-based model for nuclear explosion identification to understand the development of S-waves from explosion sources in order to enhance nuclear test ban treaty monitoring.

  14. Soaps and Suspicious Activity: Dramatic Experiences in British Classrooms.

    ERIC Educational Resources Information Center

    Ferree, Angela M.

    2001-01-01

    Offers examples of dramatic experiences (student produced soap operas) in two classrooms in British comprehensive secondary schools. Concludes that students in other countries would find such experiences as meaningful and enjoyable as their British counterparts. Notes that the two teachers managed to be flexible, appropriating effective…

  15. Experiments with planar inductive ion source meant for creation ofH+ Beams

    SciTech Connect

    Vainionpaa, J.H.; Kalvas, T.; Hahto, S.K.; Reijonen, J.

    2007-02-07

    In this article the effect of different engineering parameters of an rf-driven ion sources with external spiral antenna and quartz disk rf-window are studied. Paper consists of three main topics: The effect of source geometry on the operation gas pressure, the effect of source materials and magnetic confinement on extracted current density and ion species and the effect of different antenna geometries on the extracted current density. The operation gas pressure as a function of the plasma chamber diameter, was studied. This was done with three cylindrical plasma chambers with different inner diameters. The chamber materials were studied using two materials, aluminum and alumina (AlO{sub 2}). The removable 14 magnet multicusp confinement arrangement enabled us to compare the effects of the two wall materials with and without the magnetic confinement. Highest proton fraction of {approx} 8% at 2000 W of rf-power and at pressure of 1.3 Pa was measured using AlO{sub 2} plasma chamber and no multicusp confinement. For all the compared ion sources at 1000W of rf-power, source with multicusp confinement and AlO2 plasma chamber yields highest current density of 82.7 mA/cm{sup 2} at operation pressure of 4 Pa. From the same source highest measured current density of 143 mA/cm{sup 2} at 1.3 Pa and 2200W of rf-power was achieved. Multicusp confinement increased the maximum extracted current up to factor of two. Plasma production with different antenna geometries was also studied. Antenna tests were performed using same source geometry as in source material study with AlO{sub 2} plasma chamber and multicusp confinement. The highest current density was achieved with 4.5 loop solenoid antenna with 6 cm diameter. Slightly lower current density with lower pressure was achieved using tightly wound 3 loop spiral antenna with 3.3 cm ID and 6 cm OD.

  16. Mechanochemical activation and synthesis of nanomaterials for hydrogen storage and conversion in electrochemical power sources.

    PubMed

    Wronski, Zbigniew S; Varin, Robert A; Czujko, Tom

    2009-07-01

    In this study we discuss a process of mechanical activation employed in place of chemical or thermal activation to improve the mobility and reactivity of hydrogen atoms and ions in nanomaterials for energy applications: rechargeable batteries and hydrogen storage for fuel cell systems. Two materials are discussed. Both are used or intended for use in power sources. One is nickel hydroxide, Ni(OH)2, which converts to oxyhydroxide in the positive Ni electrode of rechargeable metal hydride batteries. The other is a complex hydride, Mg(AIH4)2, intended for use in reversible, solid-state hydrogen storage for fuel cells. The feature shared by these unlikely materials (hydroxide and hydride) is a sheet-like hexagonal crystal structure. The mechanical activation was conducted in high-energy ball mills. We discuss and demonstrate that the mechanical excitation of atoms and ions imparted on these powders stems from the same class of phenomena. These are (i) proliferation of structural defects, in particular stacking faults in a sheet-like structure of hexagonal crystals, and (ii) possible fragmentation of a faulted structure into a mosaic of layered nanocrystals. The hydrogen atoms bonded in such nanocrystals may be inserted and abstracted more easily from OH- hydroxyl group in Ni(OH)2 and AlH4- hydride complex in Mg(AlH4)2 during hydrogen charge and discharge reactions. However, the effects of mechanical excitation imparted on these powders are different. While the Ni(OH)2 powder is greatly activated for cycling in batteries, the Mg(AlH4)2 complex hydride phase is greatly destabilized for use in reversible hydrogen storage. Such a "synchronic" view of the structure-property relationship in respect to materials involved in hydrogen energy storage and conversion is supported in experiments employing X-ray diffraction (XRD), differential scanning calorimetry (DSC) and direct imaging of the structure with a high-resolution transmission-electron microscope (HREM), as well as in

  17. Experiments with planar inductive ion source meant for creation of H{sup +} beams

    SciTech Connect

    Vainionpaa, J. H.; Kalvas, T.; Hahto, S. K.; Reijonen, J.

    2007-06-15

    In this article the effects of different engineering parameters of rf-driven ion sources with an external spiral antenna and a quartz rf window are studied. This article consists of three main topics: the effect of source geometry on the operation gas pressure, the effect of source materials and magnetic confinement on extracted current density and ion species, and the effect of different antenna geometries on the extracted current density. The effect of source geometry was studied using three cylindrical plasma chambers with different inner diameters. The chamber materials were studied using two materials, aluminum (Al) and alumina (Al{sub 2}O{sub 3}). The removable 14 magnet multicusp confinement arrangement enabled us to compare the effects of the two wall materials with and without the magnetic confinement. The highest measured proton fractions were measured using Al{sub 2}O{sub 3} plasma chamber and no multicusp confinement. For the compared ion sources the source with multicusp confinement and Al{sub 2}O{sub 3} plasma chamber yields the highest current densities. Multicusp confinement increased the maximum extracted current by up to a factor of 2. Plasma production with different antenna geometries were also studied. The highest current density was achieved using 4.5 loop solenoid antenna with 6.0 cm diameter. A slightly lower current density with lower pressure was achieved using a tightly wound 3 loop spiral antenna with 3.3 cm inner diameter and 6 cm outer diameter.

  18. Experiments with planar inductive ion source meant for creation of H+ beams.

    PubMed

    Vainionpaa, J H; Kalvas, T; Hahto, S K; Reijonen, J

    2007-06-01

    In this article the effects of different engineering parameters of rf-driven ion sources with an external spiral antenna and a quartz rf window are studied. This article consists of three main topics: the effect of source geometry on the operation gas pressure, the effect of source materials and magnetic confinement on extracted current density and ion species, and the effect of different antenna geometries on the extracted current density. The effect of source geometry was studied using three cylindrical plasma chambers with different inner diameters. The chamber materials were studied using two materials, aluminum (Al) and alumina (Al(2)O(3)). The removable 14 magnet multicusp confinement arrangement enabled us to compare the effects of the two wall materials with and without the magnetic confinement. The highest measured proton fractions were measured using Al(2)O(3) plasma chamber and no multicusp confinement. For the compared ion sources the source with multicusp confinement and Al(2)O(3) plasma chamber yields the highest current densities. Multicusp confinement increased the maximum extracted current by up to a factor of 2. Plasma production with different antenna geometries were also studied. The highest current density was achieved using 4.5 loop solenoid antenna with 6.0 cm diameter. A slightly lower current density with lower pressure was achieved using a tightly wound 3 loop spiral antenna with 3.3 cm inner diameter and 6 cm outer diameter.

  19. Compact sources of suprathermal microwave emission detected in quiescent active regions during lunar occultations

    NASA Astrophysics Data System (ADS)

    Correia, E.; Kaufmann, P.; Strauss, F. M.

    1992-04-01

    Solar quiescent active regions are known to exhibit radio emission from discrete structures. The knowledge of their dimensions and brightness temperatures is essential for understanding the physics of quiescent, confined plasma regions. Solar eclipses of 10 August, 1980 and 26 January, 1990, observed with high sensitivity and high time resolution at 22 GHz, allowed an unprecedented opportunity to identify Fresnel diffraction effects during lunar occultations of active regions. The results indicate the presence of quiescent discrete sources smaller than one arcsec in one dimension. Assuming symmetrical sources, their brightness temperatures were larger than 2 x 10 exp 7 K and 8 x 10 exp 7 K, for the 1980 and 1990 observations, respectively.

  20. Development of a Measure to Assess Youth Self-Reported Experiences of Activity Settings (SEAS)

    ERIC Educational Resources Information Center

    King, Gillian; Batorowicz, Beata; Rigby, Patty; McMain-Klein, Margot; Thompson, Laura; Pinto, Madhu

    2014-01-01

    There is a need for psychometrically sound measures of youth experiences of community/home leisure activity settings. The 22-item Self-Reported Experiences of Activity Settings (SEAS) captures the following experiences of youth with a Grade 3 level of language comprehension or more: Personal Growth, Psychological Engagement, Social Belonging,…

  1. Active Control of a Moving Noise SOURCE—EFFECT of Off-Axis Source Position

    NASA Astrophysics Data System (ADS)

    GUO, J.; PAN, J.; HODGSON, M.

    2002-03-01

    An optimally arranged multiple-channel active-control system is known to be able to create a large quiet zone in free space for a stationary primary noise source. When the primary noise source moves, the active control of the noise becomes much more difficult, as the primary noise field changes with time in space. In this case, the controller of the control system must respond fast enough to compensate for the change; much research has been focused on this issue. In this paper, it is shown that a moving source also causes difficulties from an acoustical perspective. A moving source not only changes continuously the strengths and phases of the sound field in the space, but also changes the wavefront of the primary sound field continuously. It is known that the efficiency of active noise control is determined mainly by the wavefront matching between the primary and control fields. To keep the control system effective in the case of a moving source, the wavefront of the control field needs to change, in order to continuously match the primary-wavefront change. This paper shows that there are limitations to the control-wavefront change. An optimally pre-arranged, multiple-channel control system is not able to construct a matching wavefront when the primary source moves outside a certain range. In other words, the control system is still able to create a large quiet zone only when the primary source moves within a range around the central axis of the control system. Both the location and the size of the quiet zone change with the location of the primary source.

  2. Infrasound Observations from the Source Physics Experiment (Tests 1 and 2) at the Nevada National Security Site

    DTIC Science & Technology

    2012-09-01

    INFRASOUND OBSERVATIONS FROM THE SOURCE PHYSICS EXPERIMENT ( TESTS 1 AND 2) AT THE NEVADA NATIONAL SECURITY SITE Kyle R. Jones1, Rod W. Whitaker2...series of explosions, we have the unique and rare opportunity to study infrasound generated by a well-characterized source from the same borehole ...two explosive tests (SPE-N-1 and SPE-N-2) were successfully conducted on May 3 and October 25, 2011, respectively. SPE-N-1 had a yield of 0.1 tons at

  3. Studies of neutron cross-sections important for spallation experiments using the activation method

    NASA Astrophysics Data System (ADS)

    Vrzalová, J.; Chudoba, P.; Krása, A.; Majerle, M.; Suchopár, M.; Svoboda, O.; Wagner, V.

    2014-09-01

    A series of experiments devoted to studies of neutron cross-sections by activation method was carried out. The cross-sections of various threshold reactions were studied by means of different quasi-monoenergetic neutron sources with energies from 14 MeV up to 100 MeV. Threshold reactions in various materials are among other used to measure fast neutron fields produced during accelerator driven system studies. For this reason our measurements of neutron cross-sections are crucial. At present, neither experimental nor evaluated data above 30 MeV are available for neutron threshold reactions in Au, I and In published in this proceedings. We studied materials in the form of thin foils and compared our data with the calculations preformed using the deterministic code TALYS 1.4.

  4. Localization of short-range acoustic and seismic wideband sources: Algorithms and experiments

    NASA Astrophysics Data System (ADS)

    Stafsudd, J. Z.; Asgari, S.; Hudson, R.; Yao, K.; Taciroglu, E.

    2008-04-01

    We consider the determination of the location (source localization) of a disturbance source which emits acoustic and/or seismic signals. We devise an enhanced approximate maximum-likelihood (AML) algorithm to process data collected at acoustic sensors (microphones) belonging to an array of, non-collocated but otherwise identical, sensors. The approximate maximum-likelihood algorithm exploits the time-delay-of-arrival of acoustic signals at different sensors, and yields the source location. For processing the seismic signals, we investigate two distinct algorithms, both of which process data collected at a single measurement station comprising a triaxial accelerometer, to determine direction-of-arrival. The direction-of-arrivals determined at each sensor station are then combined using a weighted least-squares approach for source localization. The first of the direction-of-arrival estimation algorithms is based on the spectral decomposition of the covariance matrix, while the second is based on surface wave analysis. Both of the seismic source localization algorithms have their roots in seismology; and covariance matrix analysis had been successfully employed in applications where the source and the sensors (array) are typically separated by planetary distances (i.e., hundreds to thousands of kilometers). Here, we focus on very-short distances (e.g., less than one hundred meters) instead, with an outlook to applications in multi-modal surveillance, including target detection, tracking, and zone intrusion. We demonstrate the utility of the aforementioned algorithms through a series of open-field tests wherein we successfully localize wideband acoustic and/or seismic sources. We also investigate a basic strategy for fusion of results yielded by acoustic and seismic arrays.

  5. In and Out 101 Activities to Enrich the Learning Experience.

    ERIC Educational Resources Information Center

    Johnson, Patricia; And Others

    Activities developed and used with children and adults participating in the program offerings of the Edwin Gould Outdoor Education Centers are presented. Information describing most activities includes name, description of the activity, objectives, supervision or help required, procedures, time involved, size of area required, materials,…

  6. An Activity Group Experience for Disengaged Elderly Persons.

    ERIC Educational Resources Information Center

    Harris, John Ewing; Bodden, Jack L.

    1978-01-01

    Tested the activity theory (which proposes that elderly persons remain in active contact with their environment) and disengagement theory (which suggests adjustment comes through reduction of activity and social contact). Disengaged elderly were identified. Subjects demonstrated significant improvement over the untreated control subjects. Results…

  7. Computational modeling study of the radial line slot antenna microwave plasma source with comparisons to experiments

    SciTech Connect

    Raja, Laxminarayan L.; Mahadevan, Shankar; Ventzek, Peter L. G.; Yoshikawa, Jun

    2013-05-15

    The radial line slot antenna plasma source is a high-density microwave plasma source comprising a high electron temperature source region within the plasma skin depth from a coupling window and low electron temperature diffusion region far from the window. The plasma is typically comprised of inert gases like argon and mixtures of halogen or fluorocarbon gases for etching. Following the experimental study of Tian et al.[J. Vac. Sci. Technol. A 24, 1421 (2006)], a two-dimensional computational model is used to describe the essential features of the source. A high density argon plasma is described using the quasi-neutral approximation and coupled to a frequency-domain electromagnetic wave solver to describe the plasma-microwave interactions in the source. The plasma is described using a multispecies plasma chemistry mechanism developed specifically for microwave excitation conditions. The plasma is nonlocal by nature with locations of peak power deposition and peak plasma density being very different. The spatial distribution of microwave power coupling depends on whether the plasma is under- or over-dense and is described well by the model. The model predicts the experimentally observed low-order diffusion mode radial plasma profiles. The trends of spatial profiles of electron density and electron temperature over a wide range of power and pressure conditions compare well with experimental results.

  8. VizieR Online Data Catalog: submm point sources from the Archeops experiment (Desert+, 2008)

    NASA Astrophysics Data System (ADS)

    Desert, F.-X.; Macias-Perez, J. F.; Mayet, F.; Giardino, G.; Renault, C.; Aumont, J.; Benoit, A.; Bernard, J.-P.; Ponthieu, N.; Tristram, M.

    2008-02-01

    Table 3 gives coordinates and basic photometric properties. The name of the source gives the galactic coordinates in degrees. Fluxes and 1-sigma errors are in Jy, assuming a Rayleigh-Jeans color and for the 4 frequencies of 143, 217, 353 and 545GHz. No available measurements are quoted as (sigma=-1). Upper limits are quoted at the 2-sigma level. The bright sources with an asterisk have positional uncertainties larger than the nominal 4arcmin (1-sigma). Table 4 gives the model fit parameters and associations. For each point source, the emissivity exponent beta and temperature T are given along with the reduced chi^2 value. When the fit is unsatisfactory, beta11 (assuming a fixed temperature of 11K), or T2 (assuming a fixed exponent index of 2) are provided instead. The associated Iras source is given along with the far infrared fluxes. A star by the name of the Iras counterpart indicates that the Iras source has the Iras colors of an ultra-compact HII region. Then associations with a commonly used name are given with Lynds Dark Nebulae, Bright Nebulae, Sharpless and other common catalogs. Associations with HII regions (with angular size le 10arcmin) from the catalogue by Paladini et al. (2003, Cat. ) are also given. (2 data files).

  9. Measuring Spatial Variability of Vapor Flux to Characterize Vadose-zone VOC Sources: Flow-cell Experiments

    SciTech Connect

    Mainhagu, Jon; Morrison, C.; Truex, Michael J.; Oostrom, Martinus; Brusseau, Mark

    2014-08-05

    A method termed vapor-phase tomography has recently been proposed to characterize the distribution of volatile organic contaminant mass in vadose-zone source areas, and to measure associated three-dimensional distributions of local contaminant mass discharge. The method is based on measuring the spatial variability of vapor flux, and thus inherent to its effectiveness is the premise that the magnitudes and temporal variability of vapor concentrations measured at different monitoring points within the interrogated area will be a function of the geospatial positions of the points relative to the source location. A series of flow-cell experiments was conducted to evaluate this premise. A well-defined source zone was created by injection and extraction of a non-reactive gas (SF6). Spatial and temporal concentration distributions obtained from the tests were compared to simulations produced with a mathematical model describing advective and diffusive transport. Tests were conducted to characterize both areal and vertical components of the application. Decreases in concentration over time were observed for monitoring points located on the opposite side of the source zone from the local–extraction point, whereas increases were observed for monitoring points located between the local–extraction point and the source zone. We found that the results illustrate that comparison of temporal concentration profiles obtained at various monitoring points gives a general indication of the source location with respect to the extraction and monitoring points.

  10. Measuring Spatial Variability of Vapor Flux to Characterize Vadose-zone VOC Sources: Flow-cell Experiments

    DOE PAGES

    Mainhagu, Jon; Morrison, C.; Truex, Michael J.; ...

    2014-08-05

    A method termed vapor-phase tomography has recently been proposed to characterize the distribution of volatile organic contaminant mass in vadose-zone source areas, and to measure associated three-dimensional distributions of local contaminant mass discharge. The method is based on measuring the spatial variability of vapor flux, and thus inherent to its effectiveness is the premise that the magnitudes and temporal variability of vapor concentrations measured at different monitoring points within the interrogated area will be a function of the geospatial positions of the points relative to the source location. A series of flow-cell experiments was conducted to evaluate this premise. Amore » well-defined source zone was created by injection and extraction of a non-reactive gas (SF6). Spatial and temporal concentration distributions obtained from the tests were compared to simulations produced with a mathematical model describing advective and diffusive transport. Tests were conducted to characterize both areal and vertical components of the application. Decreases in concentration over time were observed for monitoring points located on the opposite side of the source zone from the local–extraction point, whereas increases were observed for monitoring points located between the local–extraction point and the source zone. We found that the results illustrate that comparison of temporal concentration profiles obtained at various monitoring points gives a general indication of the source location with respect to the extraction and monitoring points.« less

  11. Sources and magnitude of variability in pedometer-determined physical activity levels of youth

    PubMed Central

    Kim, So-Yeun; Park, Hye-Sang

    2015-01-01

    This study examined sources of variability in habitual physical activity of children, and the minimum number of days required for estimating children’s habitual physical activity levels using pedometers. A total of 31 children wore two pedometers during five weekdays and four weekend days. A two random facet completely crossed design was conducted with two-way analysis of variances across weekdays, weekends, and weekdays and weekend days combined. Moderate/high generalizability coefficients were estimated across all days. Primary sources of variability were variance components of the person and person by day interaction. Minimum numbers of days required for estimating habitual physical activity levels using a pedometer were five during weekdays. However, estimating habitual physical activity levels during weekends, and weekdays and weekend days combined was impractical. PMID:26730388

  12. Content of plasmatic glycerol and activity of hepatic glycerol kinase in broiler chickens fed diets containing different sources and concentrations of glycerine.

    PubMed

    Bernardino, V M P; Rodrigues, P B; de Paula Naves, L; Rosa, P V; Zangerônimo, M G; Gomide, E M; Saldanha, M M; Alvarenga, R R

    2014-04-01

    The objective of this study was to evaluate the effect of three sources of glycerine (crude glycerine from soya bean oil - CGSO, mixed crude glycerine from frying oil and lard--MCG, and a semipurified glycerine from soya bean oil--SPGSO) in four concentrations in the diet (17.5, 35.0, 52.5 and 70.0 g of each type of glycerine per kg of feed) on the levels of plasmatic glycerol and the activity of the hepatic enzyme glycerol kinase in broilers of 22-35 days old (experiment I) and 33-42 days old (experiment II). The highest (p < 0.05) plasmatic glycerol level was detected in broilers fed diet containing CGSO. Independent of the source, increasing the concentration of glycerine led to a linear increase (p < 0.05) in the plasmatic glycerol concentration. In experiment I, all the diets containing glycerine resulted in increased concentrations of plasmatic glycerol, in relation to the control diet without glycerine. However, in experiment II, only the diet containing 17.5 g of CGSO per kg of feed and the diets formulated with any of the three types of glycerine in the inclusion concentrations of 35, 52.5 and 70 g/kg of feed resulted in higher plasmatic glycerol levels than those observed in the control broilers. The source of glycerine influenced the glycerol kinase activity only in experiment II, where the use of CGSO in the diet increased the enzyme activity. For both experiments, the glycerol kinase activity increased with the inclusion of glycerine in the diet. In conclusion, based on the absence of saturation of the glycerol kinase activity for the three glycerine sources and for both rearing periods evaluated, the broilers can metabolize the glycerol (at the level of the phosphorylation of the glycerol to glycerol-3-phosphate in the liver) present in the glycerine when the diet is supplemented with up to 70 g of glycerine per kg of feed.

  13. Occurrence and potential causes of androgenic activities in source and drinking water in China.

    PubMed

    Hu, Xinxin; Shi, Wei; Wei, Si; Zhang, Xiaowei; Feng, Jianfang; Hu, Guanjiu; Chen, Sulan; Giesy, John P; Yu, Hongxia

    2013-09-17

    The increased incidences of disorders of male reproductive tract as well as testicular and prostate cancers have been attributed to androgenic pollutants in the environment. Drinking water is one pathway of exposure through which humans can be exposed. In this study, both potencies of androgen receptor (AR) agonists and antagonists were determined in organic extracts of raw source water as well as finished water from waterworks, tap water, boiled water, and poured boiled water in eastern China. Ten of 13 samples of source water exhibited detectable AR antagonistic potencies with AR antagonist equivalents (Ant-AR-EQs) ranging from <15.3 (detection limit) to 140 μg flutamide/L. However, no AR agonistic activity was detected in any source water. All finished water from waterworks, tap water, boiled water, and poured boiled water exhibited neither AR agonistic nor antagonistic activity. Although potential risks are posed by source water, water treatment processes effectively removed AR antagonists. Boiling and pouring of water further removed these pollutants. Phthalate esters (PAEs) including diisobutyl phthalate (DIBP) and dibutyl phthalate (DBP) were identified as major contributors to AR antagonistic potencies in source waters. Metabolites of PAEs exhibited no AR antagonistic activity and did not increase potencies of PAEs when they coexist.

  14. Characterization of spatially resolved high resolution x-ray spectrometers for high energy density physics and light source experiments

    SciTech Connect

    Hill, K. W. Bitter, M.; Delgado-Aparacio, L.; Efthimion, P.; Pablant, N. A.; Lu, J.; Beiersdorfer, P.; Chen, H.; Magee, E.

    2014-11-15

    A high resolution 1D imaging x-ray spectrometer concept comprising a spherically bent crystal and a 2D pixelated detector is being optimized for diagnostics of small sources such as high energy density physics (HEDP) and synchrotron radiation or x-ray free electron laser experiments. This instrument is used on tokamak experiments for Doppler measurements of ion temperature and plasma flow velocity profiles. Laboratory measurements demonstrate a resolving power, E/ΔE of order 10 000 and spatial resolution better than 10 μm. Initial tests of the high resolution instrument on HEDP plasmas are being performed.

  15. High Velocity Jet Noise Source Location and Reduction. Task 2. Theoretical Developments and Basic Experiments.

    DTIC Science & Technology

    1978-05-01

    BASIC DOCUMENT IDENTIFICATION EXPERIMENTS . FINAL REPT 9 May 78 REPT. NO. R78AEG323 Contract DOT-OS-30034 FAARD76.79.2 DISTRIBUTioN STATEMENT A... EXPERIMENTS TECHNICAL CONTRIBUTORS: T.F. Balsa R. Mani P.R. Gliebe E.J. Stringas R.A. Kantola J.C.F. Wang GENERAL ELECTRIC COMPANY AIRCRAFT ENGINE GROUP...Task 2 - Theoretical Developments and Basic Experiments 6. IormtnlOrgenizatlonCod. 7. Author(s) T.F. Balsa, P.R. Gliebe, R.A. Kantola, J.C.F

  16. Time-Dependent Moment Tensors of the First Four Source Physics Experiments (SPE) Explosions

    NASA Astrophysics Data System (ADS)

    Yang, X.

    2015-12-01

    We use mainly vertical-component geophone data within 2 km from the epicenter to invert for time-dependent moment tensors of the first four SPE explosions: SPE-1, SPE-2, SPE-3 and SPE-4Prime. We employ a one-dimensional (1D) velocity model developed from P- and Rg-wave travel times for Green's function calculations. The attenuation structure of the model is developed from P- and Rg-wave amplitudes. We select data for the inversion based on the criterion that they show consistent travel times and amplitude behavior as those predicted by the 1D model. Due to limited azimuthal coverage of the sources and the mostly vertical-component-only nature of the dataset, only long-period, diagonal components of the moment tensors are well constrained. Nevertheless, the moment tensors, particularly their isotropic components, provide reasonable estimates of the long-period source amplitudes as well as estimates of corner frequencies, albeit with larger uncertainties. The estimated corner frequencies, however, are consistent with estimates from ratios of seismogram spectra from different explosions. These long-period source amplitudes and corner frequencies cannot be fit by classical P-wave explosion source models. The results motivate the development of new P-wave source models suitable for these chemical explosions. To that end, we fit inverted moment-tensor spectra by modifying the classical explosion model using regressions of estimated source parameters. Although the number of data points used in the regression is small, the approach suggests a way for the new-model development when more data are collected.

  17. Social competence and collaborative guided inquiry science activities: Experiences of students with learning disabilities

    NASA Astrophysics Data System (ADS)

    Taylor, Jennifer Anne

    This thesis presents a qualitative investigation of the effects of social competence on the participation of students with learning disabilities (LD) in the science learning processes associated with collaborative, guided inquiry learning. An inclusive Grade 2 classroom provided the setting for the study. Detailed classroom observations were the primary source of data. In addition, the researcher conducted two interviews with the teacher, and collected samples of students' written work. The purpose of the research was to investigate: (a) How do teachers and peers mediate the participation of students with LD in collaborative, guided inquiry science activities, (b) What learning processes do students with LD participate in during collaborative, guided inquiry science activities, and (c) What components of social competence support and constrain the participation of students with LD during collaborative, guided inquiry science activities? The findings of the study suggest five key ideas for research and teaching in collaborative, guided inquiry science in inclusive classrooms. First, using a variety of collaborative learning formats (whole-class, small-group, and pairs) creates more opportunities for the successful participation of diverse students with LD. Second, creating an inclusive community where students feel accepted and valued may enhance the academic and social success of students with LD. Third, careful selection of partners for students with LD is important for a positive learning experience. Students with LD should be partnered with academically successful, socially competent peers; also, this study suggested that students with LD experience more success working collaboratively in pairs rather than in small groups. Fourth, a variety of strategies are needed to promote active participation and positive social interactions for students with and without LD during collaborative, guided inquiry learning. Fifth, adopting a general approach to teaching

  18. Generation of ultrashort coherent vacuum ultraviolet pulses using electron storage rings: a new bright light source for experiments.

    PubMed

    De Ninno, G; Allaria, E; Coreno, M; Curbis, F; Danailov, M B; Karantzoulis, E; Locatelli, A; Menteş, T O; Nino, M A; Spezzani, C; Trovò, M

    2008-08-01

    We demonstrate for the first time that seeded harmonic generation on electron storage rings can produce coherent optical pulses in the vacuum ultraviolet spectral range. The experiment is performed at Elettra, where coherent pulses are generated at 132 nm, with a duration of about 100 fs. The light source has a repetition rate of 1 kHz and adjustable polarization; it is very bright, with a peak power several orders of magnitude above that of spontaneous synchrotron radiation. Owing to high stability, the source is used in a test photoemission electron microscopy experiment. We anticipate that seeded harmonic generation on storage rings can lead to unprecedented developments in time-resolved femtosecond spectroscopy and microscopy.

  19. Simultaneous usage of pinhole and penumbral apertures for imaging small scale neutron sources from inertial confinement fusion experiments.

    PubMed

    Guler, N; Volegov, P; Danly, C R; Grim, G P; Merrill, F E; Wilde, C H

    2012-10-01

    Inertial confinement fusion experiments at the National Ignition Facility are designed to understand the basic principles of creating self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT) filled cryogenic plastic capsules. The neutron imaging diagnostic provides information on the distribution of the central fusion reaction region and the surrounding DT fuel by observing neutron images in two different energy bands for primary (13-17 MeV) and down-scattered (6-12 MeV) neutrons. From this, the final shape and size of the compressed capsule can be estimated and the symmetry of the compression can be inferred. These experiments provide small sources with high yield neutron flux. An aperture design that includes an array of pinholes and penumbral apertures has provided the opportunity to image the same source with two different techniques. This allows for an evaluation of these different aperture designs and reconstruction algorithms.

  20. Development of high-activity {sup 252}Cf sources for neutron brachytherapy

    SciTech Connect

    Martin, R.C.; Laxson, R.R.; Miller, J.H.; Wierzbicki, J.G.; Rivard, M.J.; Marsh, D.L.

    1996-10-01

    The Gershenson Radiation Oncology Center of Wayne State University (WSU), Detroit, Michigan, is using {sup 252}Cf medical sources for neutron brachytherapy. These sources are based on a 20-year-old design containing {le} 30 {micro}g {sup 252}Cf in the form of a cermet wire of Cf{sub 2}O{sub 3} in a palladium matrix. The Radiochemical Engineering Development Center (REDC) of Oak Ridge National Laboratory has been asked to develop tiny high-activity {sup 252}Cf neutron sources for use with remote afterloading equipment to reduce treatment times and dose to clinical personnel and to expedite treatment of brain and other tumors. To date, the REDC has demonstrated that {sup 252}Cf loadings can be greatly increased in cermet wires much smaller than before. Equipment designed for hot cell fabrication of these wires is being tested. A parallel program is under way to relicense the existing source design for fabrication at the REDC.

  1. The cold adaptability of microorganisms with different carbon source in activated sludge treating synthetical wastewater.

    PubMed

    Niu, Chuan; Geng, Jinju; Ren, Hongqiang; Ding, Lili; Xu, Ke

    2012-11-01

    The cold adaptability of microorganisms with different carbon source under 5°C was studied in activated sludge for treating synthetical wastewater. Phospholipid fatty acid (PLFA) analysis indicated contents of unsaturated fatty acids in cell membrane at 5°C were 13.66% and 24.96% higher for glucose and sodium acetate source than that at 25°C. PLFA biomarkers showed more Gram-negative bacteria enriched than Gram-positive bacteria in low-temperature activated sludge. The Shannon-Wiener diversity analysis demonstrated glucose fed reactor in low temperature had lower PLFA diversity index (1.21-1.30) than that at 25°C and sodium acetate source was reverse (1.08-0.69). The 16S rRNA analysis manifested certain microbes were considerably suitable for existence under cold environment, most of which belong to Gram-negative bacteria.

  2. Data Release Report for Source Physics Experiments 2 and 3 (SPE-2 and SPE-3) Nevada National Security Site

    SciTech Connect

    Townsend, Margaret; Obi, Curtis

    2015-04-30

    The second Source Physics Experiment shot (SPE-2) was conducted in Nevada on October 25, 2011, at 1900:00.011623 Greenwich Mean Time (GMT). The explosive source was 997 kilograms (kg) trinitrotoluene (TNT) equivalent of sensitized heavy ammonium fuel oil (SHANFO) detonated at a depth of 45.7 meters (m). The third Source Physics Experiment shot (SPE-3) was conducted in Nevada on July 24, 2012, at 1800:00.44835 GMT. The explosive source was 905 kg TNT equivalent of SHANFO detonated at a depth of 45.8 m. Both shots were recorded by an extensive set of instrumentation that includes sensors both at near-field (less than 100 m) and far-field (100 m or greater) distances. The near-field instruments consisted of three-component accelerometers deployed in boreholes at 15, 46, and 55 m depths around the shot and a set of single-component vertical accelerometers on the surface. The far-field network was composed of a variety of seismic and acoustic sensors, including short-period geophones, broadband seismometers, three-component accelerometers, and rotational seismometers at distances of 100 m to 25 kilometers. This report coincides with the release of these data for analysts and organizations that are not participants in this program. This report describes the second and third Source Physics Experiment shots and the various types of near-field and farfield data that are available.This revised document includes reports on baseline shift corrections for the SPE-2 and SPE-3 shots that were missing from the original January 2015 version.

  3. First application of the Laser Ion Source and Trap (LIST) for on-line experiments at ISOLDE

    NASA Astrophysics Data System (ADS)

    Fink, D. A.; Richter, S. D.; Bastin, B.; Blaum, K.; Catherall, R.; Cocolios, T. E.; Fedorov, D. V.; Fedosseev, V. N.; Flanagan, K. T.; Ghys, L.; Gottberg, A.; Imai, N.; Kron, T.; Lecesne, N.; Lynch, K. M.; Marsh, B. A.; Mendonca, T. M.; Pauwels, D.; Rapisarda, E.; Ramos, J. P.; Rossel, R. E.; Rothe, S.; Seliverstov, M. D.; Sjödin, M.; Stora, T.; Van Beveren, C.; Wendt, K. D. A.

    2013-12-01

    The Laser Ion Source and Trap (LIST) provides a new mode of operation for the resonance ionization laser ion source (RILIS) at ISOLDE/CERN, reducing the amount of surface-ionized isobaric contaminants by up to four orders of magnitude. After the first successful on-line test at ISOLDE in 2011 the LIST was further improved in terms of efficiency, selectivity, and reliability through several off-line tests at Mainz University and at ISOLDE. In September 2012, the first on-line physics experiments to use the LIST took place at ISOLDE. The measurements of the improved LIST indicate more than a twofold increase in efficiency compared to the LIST of the 2011 run. The suppression of surface-ionized francium contaminants has enabled the first in-source laser spectroscopy of 217Po and 219Po.

  4. Design of interferometer system for Keda Torus eXperiment using terahertz solid-state diode sources

    SciTech Connect

    Xie, Jinlin Wang, Haibo; Li, Hong; Lan, Tao; Liu, Adi; Liu, Wandong; Yu, Changxuan; Ding, Weixing

    2014-11-15

    A solid-state source based terahertz (THz) interferometer diagnostic system has been designed and characterized for the Keda Torus eXperiment (KTX). The THz interferometer utilizes the planar diodes based frequency multiplier (X48) to provide the probing beam at fixed frequency 0.650 THz, and local oscillator is provided by an independent solid-state diode source with tunable frequency (0.650 THz +/− 10 MHz). Both solid-state sources have approximately 1 mW power. The planar-diode mixers optimized for high sensitivity, ∼750 mV/mW, are used in the heterodyne detection system, which permits multichannel interferometer on KTX with a low phase noise. A sensitivity of {sub min} = 4.5 × 10{sup 16} m{sup −2} and a temporal resolution of 0.2 μs have been achieved during the initial bench test.

  5. The E166 experiment: Development of an Undulator-Based Polarized Positron Source for the International Linear Collider

    SciTech Connect

    Kovermann, J.; Stahl, A.; Mikhailichenko, A.A.; Scott, D.; Moortgat-Pick, G.A.; Gharibyan, V.; Pahl, P.; Poschl, R.; Schuler, K.P.; Laihem, K.; Riemann, S.; Schalicke, A.; Dollan, R.; Kolanoski, H.; Lohse, T.; Schweizer, T.; McDonald, K.T.; Batygin, Y.; Bharadwaj, V.; Bower, G.; Decker, F.J.; /SLAC /Tel Aviv U. /Tennessee U.

    2011-11-14

    A longitudinal polarized positron beam is foreseen for the international linear collider (ILC). A proof-of-principle experiment has been performed in the final focus test beam at SLAC to demonstrate the production of polarized positrons for implementation at the ILC. The E166 experiment uses a 1 m long helical undulator in a 46.6 GeV electron beam to produce a few MeV photons with a high degree of circular polarization. These photons are then converted in a thin target to generate longitudinally polarized e{sup +} and e{sup -}. The positron polarization is measured using a Compton transmission polarimeter. The data analysis has shown asymmetries in the expected vicinity of 3.4% and {approx}1% for photons and positrons respectively and the expected positron longitudinal polarization is covering a range from 50% to 90%. The full exploitation of the physics potential of an international linear collider (ILC) will require the development of polarized positron beams. Having both e{sup +} and e{sup -} beams polarized will provide new insight into structures of couplings and thus give access to physics beyond the standard model [1]. The concept for a polarized positron source is based on circularly polarized photon sources. These photons are then converted to longitudinally polarized e{sup +} and e{sup -} pairs. While in an experiment at KEK [1a], Compton backscattering is used [2], the E166 experiment uses a helical undulator to produce polarized photons. An undulator-based positron source for the ILC has been proposed in [3,4]. The proposed scheme for an ILC positron source is illustrated in figure 1. In this scheme, a 150 GeV electron beam passes through a 120 m long helical undulator to produce an intense photon beam with a high degree of circular polarization. These photons are converted in a thin target to e{sup +} e{sup -} pairs. The polarized positrons are then collected, pre-accelerated to the damping ring and injected to the main linac. The E166 experiment is

  6. Accumulated source imaging of brain activity with both low and high-frequency neuromagnetic signals

    PubMed Central

    Xiang, Jing; Luo, Qian; Kotecha, Rupesh; Korman, Abraham; Zhang, Fawen; Luo, Huan; Fujiwara, Hisako; Hemasilpin, Nat; Rose, Douglas F.

    2014-01-01

    Recent studies have revealed the importance of high-frequency brain signals (>70 Hz). One challenge of high-frequency signal analysis is that the size of time-frequency representation of high-frequency brain signals could be larger than 1 terabytes (TB), which is beyond the upper limits of a typical computer workstation's memory (<196 GB). The aim of the present study is to develop a new method to provide greater sensitivity in detecting high-frequency magnetoencephalography (MEG) signals in a single automated and versatile interface, rather than the more traditional, time-intensive visual inspection methods, which may take up to several days. To address the aim, we developed a new method, accumulated source imaging, defined as the volumetric summation of source activity over a period of time. This method analyzes signals in both low- (1~70 Hz) and high-frequency (70~200 Hz) ranges at source levels. To extract meaningful information from MEG signals at sensor space, the signals were decomposed to channel-cross-channel matrix (CxC) representing the spatiotemporal patterns of every possible sensor-pair. A new algorithm was developed and tested by calculating the optimal CxC and source location-orientation weights for volumetric source imaging, thereby minimizing multi-source interference and reducing computational cost. The new method was implemented in C/C++ and tested with MEG data recorded from clinical epilepsy patients. The results of experimental data demonstrated that accumulated source imaging could effectively summarize and visualize MEG recordings within 12.7 h by using approximately 10 GB of computer memory. In contrast to the conventional method of visually identifying multi-frequency epileptic activities that traditionally took 2–3 days and used 1–2 TB storage, the new approach can quantify epileptic abnormalities in both low- and high-frequency ranges at source levels, using much less time and computer memory. PMID:24904402

  7. Saharan dust from source to sink; first results from a transatlantic monitoring experiment

    NASA Astrophysics Data System (ADS)

    Stuut, J. B. W.; Munday, C.; Korte, L.; Van der Does, M.

    2014-12-01

    New results of a transatlantic monitoring experiment are presented. In the experiment we study the potential marine environmental effects of Saharan-dust deposition, focussing on the physical, chemical, and mineralogical properties of Saharan dust collected along a transatlantic transect at 12degN. The material is collected both at the ocean surface with floating dust collectors as well as while settling through the water column.

  8. Measuring the activity of a 51Cr neutrino source based on the gamma-radiation spectrum

    NASA Astrophysics Data System (ADS)

    Gorbachev, V. V.; Gavrin, V. N.; Ibragimova, T. V.; Kalikhov, A. V.; Malyshkin, Yu. M.; Shikhin, A. A.

    2015-12-01

    A technique for the measurement of activities of intense β sources by measuring the continuous gamma-radiation (internal bremsstrahlung) spectra is developed. A method for reconstructing the spectrum recorded by a germanium semiconductor detector is described. A method for the absolute measurement of the internal bremsstrahlung spectrum of 51Cr is presented.

  9. The Main Sources of Intersubject Variability in Neuronal Activation for Reading Aloud

    ERIC Educational Resources Information Center

    Kherif, Ferath; Josse, Goulven; Seghier, Mohamed L.; Price, Cathy J.

    2009-01-01

    The aim of this study was to find the most prominent source of intersubject variability in neuronal activation for reading familiar words aloud. To this end, we collected functional imaging data from a large sample of subjects (n = 76) with different demographic characteristics such as handedness, sex, and age, while reading. The…

  10. Promoting Conceptual Change through Active Learning Using Open Source Software for Physics Simulations

    ERIC Educational Resources Information Center

    Baser, Mustafa

    2006-01-01

    This paper reports upon an active learning approach that promotes conceptual change when studying direct current electricity circuits, using free open source software, "Qucs". The study involved a total of 102 prospective mathematics teacher students. Prior to instruction, students' understanding of direct current electricity was…

  11. [Harvest of the carbon source in wastewater by the adsorption and desorption of activated sludge].

    PubMed

    Liu, Hong-Bo; Wen, Xiang-Hua; Zhao, Fang; Mei, Yi-Jun

    2011-04-01

    The carbon source in municipal wastewater was adsorbed by activated sludge and then harvested through the hydrolysis of activated sludge. Results indicated that activated sludge had high absorbing ability towards organic carbon and phosphorus under continuous operation mode, and the average COD and TP absorption rate reached as high as 63% and 76%, respectively. Moreover, about 50% of the soluble carbon source was outside of the sludge cell and could be released under mild hydrolysis condition. Whereas the absorbed amount of nitrogen was relatively low, and the removal rate of ammonia was only 13% . Furthermore, the releases of organic carbon, nitrogen and phosphorus from the sludge absorbing pollutants in the wastewater were studied. By comparing different hydrolysis conditions of normal (pH 7.5, 20 degrees C), heating (pH 7.5, 60 degrees C) and the alkaline heating (pH 11, 60 degrees C), the last one presented the optimum hydrolysis efficiency. Under which, the release rate of COD could reach 320 mg/g after 24 hours, whereas nitrogen and phosphorus just obtained low release rates of 18 mg/g and 2 mg/g, respectively. Results indicate that the carbon source in wastewater could be harvested by the adsorption and desorption of activated sludge, and the concentrations of nitrogen and phosphorus are low and would not influence the reuse of the harvested carbon source.

  12. Active ion tracer experiments attempted in conjunction with the ion composition experiment on GEOS-2

    NASA Astrophysics Data System (ADS)

    Young, D. T.

    It is pointed out that to date six ion injection/tracer experiments have been attempted in conjunction with the GEOS-2 Ion Composition Experiment: three rocket borne Ba shaped-charge releases (Porcupine 3 and 4 and Ba-GEOS), one Li release, and two periods of operation of the Xe(+) accelerator on the SCATHA satellite. The characteristics of each of these six releases are outlined, and upper limits are placed on possible ion fluxes reaching GEOS-2. The order of magnitude of ion fluxes to be expected from each release is estimated, and it is shown that three of the experiments had no real chance of succeeding in the first place.

  13. Linac-based positron source and generation of a high density positronium cloud for the GBAR experiment

    NASA Astrophysics Data System (ADS)

    Liszkay, L.; Comini, P.; Corbel, C.; Debu, P.; Dupré, P.; Grandemange, P.; Pérez, P.; Rey, J.-M.; Ruiz, N.; Sacquin, Y.

    2013-06-01

    The aim of the recently approved GBAR (Gravitational Behaviour of Antihydrogen at Rest) experiment is to measure the acceleration of neutral antihydrogen atoms in the gravitational field of the Earth. The experimental scheme requires a high density positronium cloud as a target for antiprotons, provided by the Antiproton Decelerator (AD) - Extra Low Energy Antiproton Ring (ELENA) facility at CERN. We introduce briefly the experimental scheme and present the ongoing efforts at IRFU CEA Saclay to develop the positron source and the positron-positronium converter, which are key parts of the experiment. We have constructed a slow positron source in Saclay, based on a low energy (4.3 MeV) linear electron accelerator (linac). By using an electron target made of tungsten and a stack of thin W meshes as positron moderator, we reached a slow positron intensity that is comparable with that of 22Na-based sources using a solid neon moderator. The source feeds positrons into a high field (5 T) Penning-Malmberg trap. Intense positron pulses from the trap will be converted to slow ortho-positronium (o-Ps) by a converter structure. Mesoporous silica films appear to date to be the best candidates as converter material. We discuss our studies to find the optimal pore configuration for the positron-positronium converter.

  14. A low phase noise microwave source for atomic spin squeezing experiments in 87Rb

    NASA Astrophysics Data System (ADS)

    Chen, Zilong; Bohnet, Justin G.; Weiner, Joshua M.; Thompson, James K.

    2012-04-01

    We describe and characterize a simple, low cost, low phase noise microwave source that operates near 6.800 GHz for agile, coherent manipulation of ensembles of 87Rb. Low phase noise is achieved by directly multiplying a low phase noise 100 MHz crystal to 6.8 GHz using a nonlinear transmission line and filtering the output with custom band-pass filters. The fixed frequency signal is single sideband modulated with a direct digital synthesis frequency source to provide the desired phase, amplitude, and frequency control. Before modulation, the source has a single sideband phase noise near -140 dBc/Hz in the range of 10 kHz-1 MHz offset from the carrier frequency and -130 dBc/Hz after modulation. The resulting source is estimated to contribute added spin-noise variance 16 dB below the quantum projection noise level during quantum nondemolition measurements of the clock transition in an ensemble 7 × 105 87Rb atoms.

  15. Experiment with a crystal-assisted positron source using 6 and 10 GeV electrons

    NASA Astrophysics Data System (ADS)

    Artru, X.; Baier, V.; Beloborodov, K.; Bochek, G.; Bogdanov, A.; Bozhenok, A.; Bukin, A.; Burdin, S.; Chehab, R.; Chevallier, M.; Cizeron, R.; Dauvergne, D.; Dimova, T.; Drozdetsky, A.; Druzhinin, V.; Dubrovin, M.; Gatignon, L.; Golubev, V.; Jejcic, A.; Keppler, P.; Kirsch, R.; Kulibaba, V.; Lautesse, Ph.; Major, J.; Maslov, N.; Poizat, J.-C.; Potylitsin, A.; Remillieux, J.; Serednyakov, S.; Shary, V.; Strakhovenko, V.; Sylvia, C.; Vnukov, I.

    2003-01-01

    Axially oriented crystals, penetrated by high-energy electrons, are powerful photon sources and, hence, intense positron sources. Such kinds of positron sources have been studied experimentally at CERN, with the tertiary electron beam of the SPS having an energy of 6 and 10 GeV. Four and eight millimeters thick tungsten crystals and a compound target made of a 4 mm crystal followed by a 4 mm amorphous disk were used with an orientation along the <1 1 1> axis. The positrons were detected by a drift chamber, partially immersed in a magnetic field. The reconstructed trajectories allowed the determination of their energy and angular spectra. Significant enhancements were observed for the crystal source when compared to the amorphous one. The gain was about 3 for the 4 mm target and about 2 for the 8 mm and the compound targets. These preliminary results are described after short presentations of the experimental set-up and of the method of track reconstruction.

  16. Source apportionment of fine organic aerosol in Mexico City during the MILAGRO Experiment 2006

    NASA Astrophysics Data System (ADS)

    Stone, E. A.; Snyder, D. C.; Sheesley, R. J.; Sullivan, A. P.; Weber, R. J.; Schauer, J. J.

    2007-07-01

    Organic carbon (OC) comprises a large fraction of fine particulate matter (PM2.5) in Mexico City. Daily and select 12-h PM2.5 samples were collected in urban and peripheral sites in Mexico City from 17-30 March 2006. Samples were analyzed for OC and elemental carbon (EC) using thermal-optical filter-based methods. Real-time water-soluble organic carbon (WSOC) was collected at the peripheral site. Organic compounds, particularly molecular markers, were quantified by soxhlet extraction with methanol and dichloromethane, derivitization, and gas chromatography with mass spectrometric detection (GCMS). A chemical mass balance model (CMB) based on molecular marker species was used to determine the relative contribution of major sources to ambient OC. Motor vehicles, including diesel and gasoline, consistently accounted for 47% of OC in the urban area and 31% on the periphery. The daily contribution of biomass burning to OC was highly variable, and ranged from 5-30% at the urban site and 11-50% at the peripheral site. The remaining OC unapportioned to primary sources showed a strong correlation with WSOC and was considered to be secondary in nature. Comparison of temporally resolved OC showed that contributions from primary aerosol sources during daylight hours were not significantly different from nighttime. This study provides quantitative understanding of the important sources of OC during the MILAGRO 2006 field campaign.

  17. Source apportionment of fine organic aerosol in Mexico City during the MILAGRO experiment 2006

    NASA Astrophysics Data System (ADS)

    Stone, E. A.; Snyder, D. C.; Sheesley, R. J.; Sullivan, A. P.; Weber, R. J.; Schauer, J. J.

    2008-03-01

    Organic carbon (OC) comprises a large fraction of fine particulate matter (PM2.5) in Mexico City. Daily and select 12-h PM2.5 samples were collected in urban and peripheral sites in Mexico City from 17-30 March 2006. Samples were analyzed for OC and elemental carbon (EC) using thermal-optical filter-based methods. Real-time water-soluble organic carbon (WSOC) was collected at the peripheral site. Organic compounds, particularly molecular markers, were quantified by soxhlet extraction with methanol and dichloromethane, derivitization, and gas chromatography with mass spectrometric detection (GCMS). A chemical mass balance model (CMB) based on molecular marker species was used to determine the relative contribution of major sources to ambient OC. Motor vehicles, including diesel and gasoline, consistently accounted for 49% of OC in the urban area and 32% on the periphery. The daily contribution of biomass burning to OC was highly variable, and ranged from 5-26% at the urban site and 7-39% at the peripheral site. The remaining OC unapportioned to primary sources showed a strong correlation with WSOC and was considered to be secondary in nature. Comparison of temporally resolved OC showed that contributions from primary aerosol sources during daylight hours were not significantly different from nighttime. This study provides quantitative understanding of the important sources of OC during the MILAGRO 2006 field campaign.

  18. A low phase noise microwave source for atomic spin squeezing experiments in {sup 87}Rb

    SciTech Connect

    Chen Zilong; Bohnet, Justin G.; Weiner, Joshua M.; Thompson, James K.

    2012-04-15

    We describe and characterize a simple, low cost, low phase noise microwave source that operates near 6.800 GHz for agile, coherent manipulation of ensembles of {sup 87}Rb. Low phase noise is achieved by directly multiplying a low phase noise 100 MHz crystal to 6.8 GHz using a nonlinear transmission line and filtering the output with custom band-pass filters. The fixed frequency signal is single sideband modulated with a direct digital synthesis frequency source to provide the desired phase, amplitude, and frequency control. Before modulation, the source has a single sideband phase noise near -140 dBc/Hz in the range of 10 kHz-1 MHz offset from the carrier frequency and -130 dBc/Hz after modulation. The resulting source is estimated to contribute added spin-noise variance 16 dB below the quantum projection noise level during quantum nondemolition measurements of the clock transition in an ensemble 7 x 10{sup 5} {sup 87}Rb atoms.

  19. A low phase noise microwave source for atomic spin squeezing experiments in 87Rb.

    PubMed

    Chen, Zilong; Bohnet, Justin G; Weiner, Joshua M; Thompson, James K

    2012-04-01

    We describe and characterize a simple, low cost, low phase noise microwave source that operates near 6.800 GHz for agile, coherent manipulation of ensembles of (87)Rb. Low phase noise is achieved by directly multiplying a low phase noise 100 MHz crystal to 6.8 GHz using a nonlinear transmission line and filtering the output with custom band-pass filters. The fixed frequency signal is single sideband modulated with a direct digital synthesis frequency source to provide the desired phase, amplitude, and frequency control. Before modulation, the source has a single sideband phase noise near -140 dBc/Hz in the range of 10 kHz-1 MHz offset from the carrier frequency and -130 dBc/Hz after modulation. The resulting source is estimated to contribute added spin-noise variance 16 dB below the quantum projection noise level during quantum nondemolition measurements of the clock transition in an ensemble 7 × 10(5) (87)Rb atoms.

  20. Talker Identification across Source Mechanisms: Experiments with Laryngeal and Electrolarynx Speech

    ERIC Educational Resources Information Center

    Perrachione, Tyler K.; Stepp, Cara E.; Hillman, Robert E.; Wong, Patrick C. M.

    2014-01-01

    Purpose: The purpose of this study was to determine listeners' ability to learn talker identity from speech produced with an electrolarynx, explore source and filter differentiation in talker identification, and describe acoustic-phonetic changes associated with electrolarynx use. Method: Healthy adult control listeners learned to identify…

  1. Involving Software Engineering Students in Open Source Software Projects: Experiences from a Pilot Study

    ERIC Educational Resources Information Center

    Sowe, Sulayman K.; Stamelos, Ioannis G.

    2007-01-01

    Anecdotal and research evidences show that the Free and Open Source Software (F/OSS) development model has produced a paradigm shift in the way we develop, support, and distribute software. This shift is not only redefining the software industry but also the way we teach and learn in our software engineering (SE) courses. But for many universities…

  2. Nanotube-based source of charges for experiments with solid helium at low temperatures

    NASA Astrophysics Data System (ADS)

    Borisenko, D. N.; Walmsley, P. M.; Golov, A. I.; Kolesnikov, N. N.; Kotov, Yu. V.; Levchenko, A. A.; Mezhov-Deglin, L. P.; Fear, M. J.

    2015-07-01

    Methods of preparation of the field-emission sources of charges from carbon nanotubes suitable for study of injected charges in solid helium at low temperatures T < 1 K are presented. The sources have been prepared by arc discharge deposition of nanotubes onto a flat copper substrate or by mechanical rubbing of nanotubes into porous metal surface. The test study of the voltage-current characteristics of a diode cell with the nanotube source in superfluid He II have shown that at voltages above 120 V one can observe a relatively large current I ≥ 10-13 A of negative charges in liquid helium. The field and temperature dependences of positive and negative currents in solid 4He were studied in samples grown by the blocked capillary technique. Usage of the nanotube based source of injected charges had permitted us for the first time to observe motion of the positive charges in solid helium at temperatures below 0.1 K. The current-voltage dependence could be described by a power law I ˜Uα , with the value of the exponent α ≫ 2, much higher than what one would expect for the regime of space charge limited currents.

  3. Assessing Acoustic Sound Levels Associated with Active Source Seismic Surveys in Shallow Marine Environments

    NASA Astrophysics Data System (ADS)

    Bohnenstiehl, D. R.; Tolstoy, M.; Thode, A.; Diebold, J. B.; Webb, S. C.

    2004-12-01

    The potential effect of active source seismic research on marine mammal populations is a topic of increasing concern, and controversy surrounding such operations has begun to impact the planning and permitting of academic surveys [e.g., Malakoff, 2002 Science]. Although no causal relationship between marine mammal strandings and seismic exploration has been proven, any circumstantial evidence must be thoroughly investigated. A 2002 stranding of two beaked whales in the Gulf of California within 50 km of a R/V Ewing seismic survey has been a subject of concern for both marine seismologists and environmentalists. In order to better understand possible received levels for whales in the vicinity of these operations, modeling is combined with ground-truth calibration measurements. A wide-angle parabolic equation model, which is capable of including shear within the sediment and basement layers, is used to generate predictive models of low-frequency transmission loss within the Gulf of California. This work incorporates range-dependent bathymetry, sediment thickness, sound velocity structure and sub-bottom properties. Oceanic sounds speed profiles are derived from the U.S. Navy's seasonal GDEM model and sediment thicknesses are taken from NOAA's worldwide database. The spectral content of the Ewing's 20-airgun seismic array is constrained by field calibration in the spring of 2003 [Tolstoy et al., 2004 GRL], indicating peak energies at frequencies below a few hundred Hz, with energy spectral density showing an approximate power-law decrease at higher frequencies (being ~40 dB below peak at 1 kHz). Transmission loss is estimated along a series of radials extending from multiple positions along the ship's track, with the directivity of the array accounted for by phase-shifting point sources that are scaled by the cube root of the individual airgun volumes. This allows the time-space history of low-frequency received levels to be reconstructed within the Gulf of California

  4. Timeframe Dependent Fragment Ions Observed in In-Source Decay Experiments with β-Casein Using MALDI MS.

    PubMed

    Sekiya, Sadanori; Nagoshi, Keishiro; Iwamoto, Shinichi; Tanaka, Koichi; Takayama, Mitsuo

    2015-09-01

    The fragment ions observed with time-of-flight (TOF) and quadrupole ion trap (QIT) TOF mass spectrometers (MS) combined with matrix-assisted laser desorption/ionization in-source decay (MALDI-ISD) experiments of phosphorylated analytes β-casein and its model peptide were compared from the standpoint of the residence timeframe of analyte and fragment ions in the MALDI ion source and QIT cell. The QIT-TOF MS gave fragment c-, z'-, z-ANL, y-, and b-ions, and further degraded fragments originating from the loss of neutrals such as H(2)O, NH(3), CH(2)O (from serine), C2H4O (from threonine), and H(3)PO(4), whereas the TOF MS merely showed MALDI source-generated fragment c-, z'-, z-ANL, y-, and w-ions. The fragment ions observed in the QIT-TOF MS could be explained by the injection of the source-generated ions into the QIT cell or a cooperative effect of a little internal energy deposition, a long residence timeframe (140 ms) in the QIT cell, and specific amino acid effects on low-energy CID, whereas the source-generated fragments (c-, z'-, z-ANL, y-, and w-ions) could be a result of prompt radical-initiated fragmentation of hydrogen-abundant radical ions [M + H + H](+) and [M + H - H](-) within the 53 ns timeframe, which corresponds to the delayed extraction time. The further degraded fragment b/y-ions produced in the QIT cell were confirmed by positive- and negative-ion low-energy CID experiments performed on the source-generated ions (c-, z'-, and y-ions). The loss of phosphoric acid (98 u) from analyte and fragment ions can be explained by a slow ergodic fragmentation independent of positive and negative charges.

  5. Timeframe Dependent Fragment Ions Observed in In-Source Decay Experiments with β-Casein Using MALDI MS

    NASA Astrophysics Data System (ADS)

    Sekiya, Sadanori; Nagoshi, Keishiro; Iwamoto, Shinichi; Tanaka, Koichi; Takayama, Mitsuo

    2015-09-01

    The fragment ions observed with time-of-flight (TOF) and quadrupole ion trap (QIT) TOF mass spectrometers (MS) combined with matrix-assisted laser desorption/ionization in-source decay (MALDI-ISD) experiments of phosphorylated analytes β-casein and its model peptide were compared from the standpoint of the residence timeframe of analyte and fragment ions in the MALDI ion source and QIT cell. The QIT-TOF MS gave fragment c-, z'-, z-ANL, y-, and b-ions, and further degraded fragments originating from the loss of neutrals such as H2O, NH3, CH2O (from serine), C2H4O (from threonine), and H3PO4, whereas the TOF MS merely showed MALDI source-generated fragment c-, z'-, z-ANL, y-, and w-ions. The fragment ions observed in the QIT-TOF MS could be explained by the injection of the source-generated ions into the QIT cell or a cooperative effect of a little internal energy deposition, a long residence timeframe (140 ms) in the QIT cell, and specific amino acid effects on low-energy CID, whereas the source-generated fragments (c-, z'-, z-ANL, y-, and w-ions) could be a result of prompt radical-initiated fragmentation of hydrogen-abundant radical ions [M + H + H]+ and [M + H - H]- within the 53 ns timeframe, which corresponds to the delayed extraction time. The further degraded fragment b/y-ions produced in the QIT cell were confirmed by positive- and negative-ion low-energy CID experiments performed on the source-generated ions (c-, z'-, and y-ions). The loss of phosphoric acid (98 u) from analyte and fragment ions can be explained by a slow ergodic fragmentation independent of positive and negative charges.

  6. Battery-powered pulsed high density inductively coupled plasma source for pre-ionization in laboratory astrophysics experiments

    NASA Astrophysics Data System (ADS)

    Chaplin, Vernon H.; Bellan, Paul M.

    2015-07-01

    An electrically floating radiofrequency (RF) pre-ionization plasma source has been developed to enable neutral gas breakdown at lower pressures and to access new experimental regimes in the Caltech laboratory astrophysics experiments. The source uses a customized 13.56 MHz class D RF power amplifier that is powered by AA batteries, allowing it to safely float at 3-6 kV with the electrodes of the high voltage pulsed power experiments. The amplifier, which is capable of 3 kW output power in pulsed (<1 ms) operation, couples electrical energy to the plasma through an antenna external to the 1.1 cm radius discharge tube. By comparing the predictions of a global equilibrium discharge model with the measured scalings of plasma density with RF power input and axial magnetic field strength, we demonstrate that inductive coupling (rather than capacitive coupling or wave damping) is the dominant energy transfer mechanism. Peak ion densities exceeding 5 × 1019 m-3 in argon gas at 30 mTorr have been achieved with and without a background field. Installation of the pre-ionization source on a magnetohydrodynamically driven jet experiment reduced the breakdown time and jitter and allowed for the creation of hotter, faster argon plasma jets than was previously possible.

  7. Battery-powered pulsed high density inductively coupled plasma source for pre-ionization in laboratory astrophysics experiments.

    PubMed

    Chaplin, Vernon H; Bellan, Paul M

    2015-07-01

    An electrically floating radiofrequency (RF) pre-ionization plasma source has been developed to enable neutral gas breakdown at lower pressures and to access new experimental regimes in the Caltech laboratory astrophysics experiments. The source uses a customized 13.56 MHz class D RF power amplifier that is powered by AA batteries, allowing it to safely float at 3-6 kV with the electrodes of the high voltage pulsed power experiments. The amplifier, which is capable of 3 kW output power in pulsed (<1 ms) operation, couples electrical energy to the plasma through an antenna external to the 1.1 cm radius discharge tube. By comparing the predictions of a global equilibrium discharge model with the measured scalings of plasma density with RF power input and axial magnetic field strength, we demonstrate that inductive coupling (rather than capacitive coupling or wave damping) is the dominant energy transfer mechanism. Peak ion densities exceeding 5 × 10(19) m(-3) in argon gas at 30 mTorr have been achieved with and without a background field. Installation of the pre-ionization source on a magnetohydrodynamically driven jet experiment reduced the breakdown time and jitter and allowed for the creation of hotter, faster argon plasma jets than was previously possible.

  8. Inexpensive Audio Activities: Earbud-based Sound Experiments

    NASA Astrophysics Data System (ADS)

    Allen, Joshua; Boucher, Alex; Meggison, Dean; Hruby, Kate; Vesenka, James

    2016-11-01

    Inexpensive alternatives to a number of classic introductory physics sound laboratories are presented including interference phenomena, resonance conditions, and frequency shifts. These can be created using earbuds, economical supplies such as Giant Pixie Stix® wrappers, and free software available for PCs and mobile devices. We describe two interference laboratories (beat frequency and two-speaker interference) and two resonance laboratories (quarter- and half-wavelength). Lastly, a Doppler laboratory using rotating earbuds is explained. The audio signal captured by all experiments is analyzed on free spectral analysis software and many of the experiments incorporate the unifying theme of measuring the speed of sound in air.

  9. Oscillatory behavior of US -galactosidase enzyme activity in Escherichia coli during perturbed batch experiments

    SciTech Connect

    Pih, N.P.; Dhurjat, P.

    1987-02-05

    The behaviour of a wild-type and mutant strain of Escherichia coli under batch aerobic conditions were studied. In these experiments the bacteria were initially grown with lactose as the sole carbon source. When exponential growth on lactose was achieved, the batch was perturbed with D-glucose. Periodic off-line samples were taken from the fermentor and analyzed for US -galactosidase enzyme activity, D-glucose, and lactose. Continuous on-line measurements of optical density of fermentation media were also made. Oscillations in the measured enzyme activity were observed. Oscillatory behavior of US -galactosidase enzyme in E. coli was previously reported by Knorre. In his study cells were grown in D-glucose, washed, and then grown on lactose. Oscillations were attributed to the varying enzyme synthesis rate. In the present study the cells were grown initally on lactose, thus assuring high synthesis rates of US -galactosidase from the start. The oscillations observed after perturbation with glucose are pronounced and appear to be the result of combined changes in the substrate transport system and enzyme activity in addition to possible changes in enzyme synthesis rate. 10 references.

  10. Graduate Student Perceptions and Experiences of Professional Development Activities

    ERIC Educational Resources Information Center

    Rizzolo, Sonja; DeForest, Aubreena R.; DeCino, Daniel A.; Strear, Molly; Landram, Suzanne

    2016-01-01

    Graduate higher education has done little to assess and understand graduate students' needs and experiences beyond the classroom. Therefore, we conducted a phenomenological study using multiple data collection tools, including survey and focus groups from two different time periods to implement a multiphase needs assessment. The goal of the…

  11. Bioanalytical and instrumental analysis of estrogenic activities in drinking water sources from Yangtze River Delta.

    PubMed

    Hu, Xinxin; Shi, Wei; Cao, Fu; Hu, Guanjiu; Hao, Yingqun; Wei, Si; Wang, Xinru; Yu, Hongxia

    2013-02-01

    The estrogenic activities of source water from Yangtze River, Huaihe River, Taihu Lake and groundwater in Yangtze River Delta in the dry and wet season were determined by use of reporter gene assays based on African green monkey kidney (CV-1) cell lines. Higher estrogenic activities were observed in the dry season, and the estrogenic potentials in water samples from Taihu Lake were greater than other river basins. None of the samples from groundwater showed estrogen receptor (ER) agonist activity. The 17β-Estradiol (E2) equivalents (EEQs) of water samples in the dry season ranged from 9.41×10(-1) to 1.20×10(1) ng E2 L(-1). In the wet season, EEQs of all the water samples were below the detection limit as 9.00×10(-1) ng E2 L(-1) except for one sample from Huaihe River. The highest contribution of E2 was detected in Yangtze River as 99% of estrogenic activity. Nonylphenol (NP, 100% detection rate) and octylphenol (OP, 100% detection rate) might also be responsible for the estrogenic activities in water sources. Potential health risk induced by the estrogenic chemicals in source water may be posed to the residents through water drinking.

  12. Antimicrobial activity of bacterial isolates from different floral sources of honey.

    PubMed

    Lee, Hyungjae; Churey, John J; Worobo, Randy W

    2008-08-15

    More than two thousand bacterial strains isolated from six US domestic honeys and two manuka honeys from New Zealand were screened for production of antimicrobial compounds. A high incidence of antimicrobial inhibition determined by deferred inhibition assays was observed with the bacterial isolates from all eight honey samples. In total, 2217 isolates out of 2398 strains (92.5% of total isolates) exhibited antimicrobial activity against at least one of the tested microorganisms. Antifungal activity by bacterial isolates originating from the eight honeys ranged from 44.4% to 98.0%. Bacterial isolates from manuka honey (MH1) exhibited antimicrobial activity against Bacillus subtilis ATCC 6633 and Bacillus cereus F4552, at 51.5% and 53.3% of the isolates, respectively. However, less than 30% of the bacterial isolates from the other manuka honey (MH2) and six domestic honey sources exhibited anti-Bacillus activity. Listeria monocytogenes F2-586 1053 showed higher overall rates of sensitivity to between 11 and 66% of the bacterial isolates. The high rate of antimicrobial activity exhibited by the bacterial strains isolated from different honey sources could provide potential sources of novel antimicrobial compounds.

  13. Actively cooled plasma electrode for long pulse operations in a cesium-seeded negative ion source

    NASA Astrophysics Data System (ADS)

    Fujiwara, Yukio; Watanabe, Kazuhiro; Okumura, Yoshikazu; Trainham, Rusty; Jacquot, Claude

    2005-01-01

    An actively cooled plasma electrode has been developed for long pulse operation in a cesium-seeded negative ion source. To keep the electrode temperature at about 300°C, which is the optimum range of temperature to enhance cesium effects, the electrode cooling structure has been designed using three-dimensional numerical simulation assuming that the heat flux from the source plasma was 15W/cm2. Water cooling tubes were brazed to the plasma electrode substrate with spacers made of stainless steel, which acts as a thermal resistance. The fabricated plasma electrode has been tested in a cesium-seeded volume negative ion source called Kamaboko source. The temperature of the electrode reached 280°C for the arc power of 41kW, which is the operating condition required for producing D- beams with current densities exceeding 20mA/cm2. It was demonstrated that the actively cooled plasma electrode is applicable to long pulse operations, meeting the temperature requirement for optimizing the surface-production process of negative ions in the cesium-seeded ion source.

  14. A review on biological sources, chemistry and pharmacological activities of pinostrobin.

    PubMed

    Patel, Neeraj K; Jaiswal, Gaurav; Bhutani, Kamlesh K

    2016-09-01

    Pinostrobin, a dietary bioflavonoid discovered more than 6 decades ago in the heart-wood of pine (Pinus strobus), has depicted many pharmacological activities including anti-viral, anti-oxidant, anti-leukaemic, anti-inflammatory and anti-aromatase activities. It is an inhibitor of sodium channel and Ca(2+) signalling pathways and also inhibits intestinal smooth muscle contractions. In spite of the fact that pinostrobin has an application as functional foods, till-to-date no comprehensive review on pinostrobin has been carried out. Hence, the present review deals with the biological sources, chemistry and pharmacological activities of pinostrobin.

  15. Source term experiment STEP-3 simulating a PWR severe station blackout

    SciTech Connect

    Simms, R.; Baker, L. Jr.; Ritzman, R.L.

    1987-05-21

    For a severe PWR accident that leads to a loss of feedwater to the steam generators, such as might occur in a station blackout, fission product decay heating will cause a water boiloff. Without effective cooling of the core, steam will begin to oxidize the Zircaloy cladding. The noble gases and volatile fission products, such as Cs and I, that are major contributors to the radiological source term, will be released from the damaged fuel shortly after cladding failure. The accident environment when these volatile fission products escape was simulated in STEP-3 using four fuel elements from the Belgonucleaire BR3 reactor. The primary objective was to examine the releases in samples collected as close to the test zone as possible. In this paper, an analysis of the temperatures and hydrogen generation is compared with the measurements. The analysis is needed to estimate releases and characterize conditions at the source for studies of fission product transport.

  16. Experiment Automation with a Robot Arm using the Liquids Reflectometer Instrument at the Spallation Neutron Source

    SciTech Connect

    Zolnierczuk, Piotr A; Vacaliuc, Bogdan; Sundaram, Madhan; Parizzi, Andre A; Halbert, Candice E; Hoffmann, Michael C; Greene, Gayle C; Browning, Jim; Ankner, John Francis

    2013-01-01

    The Liquids Reflectometer instrument installed at the Spallation Neutron Source (SNS) enables observations of chemical kinetics, solid-state reactions and phase-transitions of thin film materials at both solid and liquid surfaces. Effective measurement of these behaviors requires each sample to be calibrated dynamically using the neutron beam and the data acquisition system in a feedback loop. Since the SNS is an intense neutron source, the time needed to perform the measurement can be the same as the alignment process, leading to a labor-intensive operation that is exhausting to users. An update to the instrument control system, completed in March 2013, implemented the key features of automated sample alignment and robot-driven sample management, allowing for unattended operation over extended periods, lasting as long as 20 hours. We present a case study of the effort, detailing the mechanical, electrical and software modifications that were made as well as the lessons learned during the integration, verification and testing process.

  17. Experiences from nonevaporable getter-coated vacuum chambers at the MAX II synchrotron light source

    SciTech Connect

    Hansson, A.; Wallen, E.; Berglund, M.; Kersevan, R.; Hahn, M.

    2010-03-15

    Vacuum chambers coated with nonevaporable getter (NEG) materials have been used in straight sections of synchrotron light sources for the past 10 years. The MAX II storage ring, where four NEG-coated insertion device vacuum chambers and three NEG-coated dipole vacuum chambers have been installed, is the first synchrotron light source to also use NEG-coated dipole vacuum chambers. In connection with the installation of the latest two NEG-coated dipole chambers in April 2009, the evolution of the pressure and lifetime-limiting effects in MAX II has been determined from measurements with movable scrapers. The results have been compared with results from scraper measurements done in 2003, before any NEG-coated vacuum chambers were installed in the storage ring. Less than three months after the installation of the latest dipole chambers the vacuum system in MAX II was performing well with a pressure already lower than the pressure measured in 2003.

  18. High Energy Laboratory Astrophysics Experiments using electron beam ion traps and advanced light sources

    NASA Astrophysics Data System (ADS)

    Brown, Gregory V.; Beiersdorfer, Peter; Bernitt, Sven; Eberle, Sita; Hell, Natalie; Kilbourne, Caroline; Kelley, Rich; Leutenegger, Maurice; Porter, F. Scott; Rudolph, Jan; Steinbrugge, Rene; Traebert, Elmar; Crespo-Lopez-Urritia, Jose R.

    2015-08-01

    We have used the Lawrence Livermore National Laboratory's EBIT-I electron beam ion trap coupled with a NASA/GSFC microcalorimeter spectrometer instrument to systematically address problems found in the analysis of high resolution X-ray spectra from celestial sources, and to benchmark atomic physics codes employed by high resolution spectral modeling packages. Our results include laboratory measurements of transition energies, absolute and relative electron impact excitation cross sections, charge exchange cross sections, and dielectronic recombination resonance strengths. More recently, we have coupled to the Max-Plank Institute for Nuclear Physics-Heidelberg's FLASH-EBIT electron beam ion trap to third and fourth generation advanced light sources to measure photoexcitation and photoionization cross sections, as well as, natural line widths of X-ray transitions in highly charged iron ions. Selected results will be presented.

  19. Development of a Supersonic Atomic Oxygen Nozzle Beam Source for Crossed Beam Scattering Experiments

    DOE R&D Accomplishments Database

    Sibener, S. J.; Buss, R. J.; Lee, Y. T.

    1978-05-01

    A high pressure, supersonic, radio frequency discharge nozzle beam source was developed for the production of intense beams of ground state oxygen atoms. An efficient impedance matching scheme was devised for coupling the radio frequency power to the plasma as a function of both gas pressure and composition. Techniques for localizing the discharge directly behind the orifice of a water-cooled quartz nozzle were also developed. The above combine to yield an atomic oxygen beam source which produces high molecular dissociation in oxygen seeded rare gas mixtures at total pressures up to 200 torr: 80 to 90% dissociation for oxygen/argon mixtures and 60 to 70% for oxygen/helium mixtures. Atomic oxygen intensities are found to be greater than 10{sup 17} atom sr{sup -1} sec{sup -1}. A brief discussion of the reaction dynamics of 0 + IC1 ..-->.. I0 + C1 is also presented.

  20. Prospects for the Simultaneous Operation of the Tevatron Collider and pp Experiments in the Antiproton Source Accumulator

    SciTech Connect

    Werkema, Steven J.; /Fermilab

    2001-06-07

    This document is a slightly expanded version of a portion of the Proton Driver design report. The Proton Driver group gets the credit for the original idea of running an Accumulator experiment in the BTeV era. The work presented here is a study of the feasibility of this idea. The addition of the Recycler Ring to the Fermilab accelerator complex provides an opportunity to continue the program of {bar p}p physics in the Antiproton Source Accumulator that was started by Fermilab experiments E760 and E835. The operational scenario presented here utilizes the Recycler Ring as an antiproton bank from which the colliders makes 'withdrawals' as needed to maintain the required luminosity in the Tevatron. The Accumulator is only needed to re-supply the bank in between withdrawals. When the {anti p} stacking rate is sufficiently high, and the luminosity requirements of the Collider experiments are sufficiently low, there will be time between Collider fills and subsequent refilling of the recycler to deliver beam to an experiment in the Accumulator. In the scenario envisioned here, the impact of the Accumulator experiment on the luminosity delivered to the Collider experiments is very small. If the Run II antiproton stacking rate goals are met, the operational conditions required for running Accumulator based experiments will be met during the BTeV era. A simple model of the operation of the Fermilab accelerator complex for BTeV and an experiment in the Accumulator has been developed. The model makes predictions of the rate at which luminosity is delivered to BTeV and an Accumulator experiment. This model was used to examine the impact of the proton driver on this experimental program.

  1. A liquid jet setup for x-ray scattering experiments on complex liquids at free-electron laser sources

    NASA Astrophysics Data System (ADS)

    Steinke, I.; Walther, M.; Lehmkühler, F.; Wochner, P.; Valerio, J.; Mager, R.; Schroer, M. A.; Lee, S.; Roseker, W.; Jain, A.; Sikorski, M.; Song, S.; Hartmann, R.; Huth, M.; Strüder, L.; Sprung, M.; Robert, A.; Fuoss, P. H.; Stephenson, G. B.; Grübel, G.

    2016-06-01

    In this paper we describe a setup for x-ray scattering experiments on complex fluids using a liquid jet. The setup supports Small and Wide Angle X-ray Scattering (SAXS/WAXS) geometries. The jet is formed by a gas-dynamic virtual nozzle (GDVN) allowing for diameters ranging between 1 μm and 20 μm at a jet length of several hundred μm. To control jet properties such as jet length, diameter, or flow rate, the instrument is equipped with several diagnostic tools. Three microscopes are installed to quantify jet dimensions and stability in situ. The setup has been used at several beamlines performing both SAXS and WAXS experiments. As a typical example we show an experiment on a colloidal dispersion in a liquid jet at the X-ray Correlation Spectroscopy instrument at the Linac Coherent Light Source free-electron laser.

  2. A liquid jet setup for x-ray scattering experiments on complex liquids at free-electron laser sources.

    PubMed

    Steinke, I; Walther, M; Lehmkühler, F; Wochner, P; Valerio, J; Mager, R; Schroer, M A; Lee, S; Roseker, W; Jain, A; Sikorski, M; Song, S; Hartmann, R; Huth, M; Strüder, L; Sprung, M; Robert, A; Fuoss, P H; Stephenson, G B; Grübel, G

    2016-06-01

    In this paper we describe a setup for x-ray scattering experiments on complex fluids using a liquid jet. The setup supports Small and Wide Angle X-ray Scattering (SAXS/WAXS) geometries. The jet is formed by a gas-dynamic virtual nozzle (GDVN) allowing for diameters ranging between 1 μm and 20 μm at a jet length of several hundred μm. To control jet properties such as jet length, diameter, or flow rate, the instrument is equipped with several diagnostic tools. Three microscopes are installed to quantify jet dimensions and stability in situ. The setup has been used at several beamlines performing both SAXS and WAXS experiments. As a typical example we show an experiment on a colloidal dispersion in a liquid jet at the X-ray Correlation Spectroscopy instrument at the Linac Coherent Light Source free-electron laser.

  3. Active Drumming Experience Increases Infants’ Sensitivity to Audiovisual Synchrony during Observed Drumming Actions

    PubMed Central

    Timmers, Renee; Hunnius, Sabine

    2015-01-01

    In the current study, we examined the role of active experience on sensitivity to multisensory synchrony in six-month-old infants in a musical context. In the first of two experiments, we trained infants to produce a novel multimodal effect (i.e., a drum beat) and assessed the effects of this training, relative to no training, on their later perception of the synchrony between audio and visual presentation of the drumming action. In a second experiment, we then contrasted this active experience with the observation of drumming in order to test whether observation of the audiovisual effect was as effective for sensitivity to multimodal synchrony as active experience. Our results indicated that active experience provided a unique benefit above and beyond observational experience, providing insights on the embodied roots of (early) music perception and cognition. PMID:26111226

  4. Active Drumming Experience Increases Infants' Sensitivity to Audiovisual Synchrony during Observed Drumming Actions.

    PubMed

    Gerson, Sarah A; Schiavio, Andrea; Timmers, Renee; Hunnius, Sabine

    2015-01-01

    In the current study, we examined the role of active experience on sensitivity to multisensory synchrony in six-month-old infants in a musical context. In the first of two experiments, we trained infants to produce a novel multimodal effect (i.e., a drum beat) and assessed the effects of this training, relative to no training, on their later perception of the synchrony between audio and visual presentation of the drumming action. In a second experiment, we then contrasted this active experience with the observation of drumming in order to test whether observation of the audiovisual effect was as effective for sensitivity to multimodal synchrony as active experience. Our results indicated that active experience provided a unique benefit above and beyond observational experience, providing insights on the embodied roots of (early) music perception and cognition.

  5. Real-time analysis, visualization, and steering of microtomography experiments at photon sources

    SciTech Connect

    von Laszeski, G.; Insley, J. A.; Foster, I.; Bresnahan, J.; Kesselman, C.; Su, M.; Thiebaux, M.; Rivers, M. L.; Wang, S.; Tieman, B., McNulty, I.

    2000-02-29

    A new generation of specialized scientific instruments called synchrotron light sources allow the imaging of materials at very fine scales. However, in contrast to a traditional microscope, interactive use has not previously been possible because of the large amounts of data generated and the considerable computation required translating this data into a useful image. The authors describe a new software architecture that uses high-speed networks and supercomputers to enable quasi-real-time and hence interactive analysis of synchrotron light source data. This architecture uses technologies provided by the Globus computational grid toolkit to allow dynamic creation of a reconstruction pipeline that transfers data from a synchrotron source beamline to a preprocessing station, next to a parallel reconstruction system, and then to multiple visualization stations. Collaborative analysis tools allow multiple users to control data visualization. As a result, local and remote scientists can see and discuss preliminary results just minutes after data collection starts. The implications for more efficient use of this scarce resource and for more effective science appear tremendous.

  6. Parallax diagnostics of radiation source geometric dilution for iron opacity experiments

    SciTech Connect

    Nagayama, T.; Bailey, J. E.; Loisel, G.; Rochau, G. A.; Falcon, R. E.

    2014-11-15

    Experimental tests are in progress to evaluate the accuracy of the modeled iron opacity at solar interior conditions [J. E. Bailey et al., Phys. Plasmas 16, 058101 (2009)]. The iron sample is placed on top of the Sandia National Laboratories z-pinch dynamic hohlraum (ZPDH) radiation source. The samples are heated to 150–200 eV electron temperatures and 7× 10{sup 21}–4× 10{sup 22} cm{sup −3} electron densities by the ZPDH radiation and backlit at its stagnation [T. Nagayama et al., Phys. Plasmas 21, 056502 (2014)]. The backlighter attenuated by the heated sample plasma is measured by four spectrometers along ±9° with respect to the z-pinch axis to infer the sample iron opacity. Here, we describe measurements of the source-to-sample distance that exploit the parallax of spectrometers that view the half-moon-shaped sample from ±9°. The measured sample temperature decreases with increased source-to-sample distance. This distance must be taken into account for understanding the sample heating.

  7. Parallax diagnostics of radiation source geometric dilution for iron opacity experiments.

    PubMed

    Nagayama, T; Bailey, J E; Loisel, G; Rochau, G A; Falcon, R E

    2014-11-01

    Experimental tests are in progress to evaluate the accuracy of the modeled iron opacity at solar interior conditions [J. E. Bailey et al., Phys. Plasmas 16, 058101 (2009)]. The iron sample is placed on top of the Sandia National Laboratories z-pinch dynamic hohlraum (ZPDH) radiation source. The samples are heated to 150-200 eV electron temperatures and 7× 10(21)-4× 10(22) cm(-3) electron densities by the ZPDH radiation and backlit at its stagnation [T. Nagayama et al., Phys. Plasmas 21, 056502 (2014)]. The backlighter attenuated by the heated sample plasma is measured by four spectrometers along ±9° with respect to the z-pinch axis to infer the sample iron opacity. Here, we describe measurements of the source-to-sample distance that exploit the parallax of spectrometers that view the half-moon-shaped sample from ±9°. The measured sample temperature decreases with increased source-to-sample distance. This distance must be taken into account for understanding the sample heating.

  8. Insights into the Galactic Cosmic-ray Source from the TIGER Experiment

    NASA Technical Reports Server (NTRS)

    Link, Jason T.; Barbier, L. M.; Binns, W. R.; Christian, E. R.; Cummings, J. R.; Geier, S.; Israel, M. H.; Lodders, K.; Mewaldt,R. A.; Mitchell, J. W.; deNolfo, G. A.; Rauch, B. F.; Schindler, S. M.; Scott, L. M.; Streitmatter, R. E.; Stone, E. C.; Waddington, C. J.; Wiedenbeck, M. E.

    2009-01-01

    We report results from 50 days of data accumulated in two Antarctic flights of the Trans-Iron Galactic Element Recorder (TIGER). With a detector system composed of scintillators, Cherenkov detectors, and scintillating optical fibers, TIGER has a geometrical acceptance of 1.7 sq m sr and a charge resolution of 0.23 cu at Iron. TIGER has obtained abundance measurements of some of the rare galactic cosmic rays heavier than iron, including Zn, Ga, Ge, Se, and Sr, as well as the more abundant lighter elements (down to Si). The heavy elements have long been recognized as important probes of the nature of the galactic cosmic-ray source and accelerator. After accounting for fragmentation of cosmic-ray nuclei as they propagate through the Galaxy and the atmosphere above the detector system, the TIGER source abundances are consistent with a source that is a mixture of about 20% ejecta from massive stars and 80% interstellar medium with solar system composition. This result supports a model of cosmic-ray origin in OB associations previously inferred from ACE-CRIS data of more abundant lighter elements. These TIGER data also support a cosmic-ray acceleration model in which elements present in interstellar grains are accelerated preferentially compared with those found in interstellar gas.

  9. Nitrogen Source Activates TOR (Target of Rapamycin) Complex 1 via Glutamine and Independently of Gtr/Rag Proteins*

    PubMed Central

    Stracka, Daniele; Jozefczuk, Szymon; Rudroff, Florian; Sauer, Uwe; Hall, Michael N.

    2014-01-01

    The evolutionary conserved TOR complex 1 (TORC1) activates cell growth in response to nutrients. In yeast, TORC1 responds to the nitrogen source via a poorly understood mechanism. Leucine, and perhaps other amino acids, activates TORC1 via the small GTPases Gtr1 and Gtr2, orthologs of the mammalian Rag GTPases. Here we investigate the activation of TORC1 by the nitrogen source and how this might be related to TORC1 activation by Gtr/Rag. The quality of the nitrogen source, as defined by its ability to promote growth and glutamine accumulation, directly correlates with its ability to activate TORC1 as measured by Sch9 phosphorylation. Preferred nitrogen sources stimulate rapid, sustained Sch9 phosphorylation and glutamine accumulation. Inhibition of glutamine synthesis reduces TORC1 activity and growth. Poor nitrogen sources stimulate rapid but transient Sch9 phosphorylation. A Gtr1 deficiency prevents the transient stimulation of TORC1 but does not affect the sustained TORC1 activity in response to good nitrogen sources. These findings suggest that the nitrogen source must be converted to glutamine, the preferred nitrogen source in yeast, to sustain TORC1 activity. Furthermore, sustained TORC1 activity is independent of Gtr/Rag. Thus, the nitrogen source and Gtr/Rag activate TORC1 via different mechanisms. PMID:25063813

  10. Renewable energy and rural development activities experience in Bangladesh

    SciTech Connect

    Barua, D.C.

    1997-12-01

    The per capita per year fuel consumption in Bangladesh is only 56 kg oil equivalent. The supply of electricity by Bangladesh power development board (BPDB) and Dhaka electricity supply authority (DESA) is mainly confined to cities and towns. Rural Electrification Board (REB) distributes electricity to the rural people through cooperatives. The rural cooperatives cover only 10% of the total population. Only about 15% of the total population is directly connected to the electricity. In order to meet the increasing energy demand for development of agriculture and industry and for the generation of better employment opportunities, it will be necessary to harness all the available alternative sources of energy immediately.

  11. Source-apportionment and model evaluation: experiences with the EMEP SOA model

    NASA Astrophysics Data System (ADS)

    Simpson, D.; Yttri, K. E.

    2009-04-01

    The EMEP MSC-W chemical transport model (Simpson et al., 2003) has been successfully used for the prediction of photochemical oxidants and various inorganic aerosol components (sulphate, nitrate, ammonium) for many years. The model generally performs well for such species, as should be expected for compounds whose emission sources and chemistry are fairly well know. For carbonaceous particulate matter (PCM) however the model has been found to give very different results in different parts of Europe, with typically poor performance in southern Europe, but rather good results in Northern Europe (Simpson et al., 2007). Earlier comparison with the results of source-apportionment studies from the CARBOSOL project (Gelencser et al., 2007, Simpson et al., 2007) has shown that the poor performance in southern Europe can partly be ascribed to difficulties with emissions from residential wood-burning, and partly due to an underestimate of the secondary organic aerosol (SOA) component. Such difficulties are expected for organic aerosols, a subject where the basic science is only partially understood, and where new experimental results continually lead to revisions in existing ideas concerning sources and formation mechanisms (e.g. Hallquist et al., 2009). In such a situation, it is essential that model results are evaluated as thoroughly as possible, and that where possible the various components of organic aerosol can be evaluated separately. A number of source-apportionment (SA) studies have recently become available in Europe, in which data on elemental carbon (EC), organic carbon (OC), 14C, levoglucosan, and various markers of primary organic carbon (cellulose, sugars/sugar-alcohols) have allowed estimates of various sources of carbonaceous particulate matter (PCM). As well as CARBOSOL, these studies include various sites in Switzerland (e.g. Lanz et al., 2008, Szidat et al., 2006), data are available from Gothenburg in Sweden (Szidat et al., 2008) and from southern

  12. Paraxial SGM beamlines for coherence experiments at the Advanced Light Source

    SciTech Connect

    Warwick, Anthony I; Warwick, Anthony I; Howells, Malcolm

    2008-07-24

    Beamlines have been designed for coherence experiments at the ALS based on brightness preserving spherical grating monochromators. The operation is almost paraxial so that a very simple scheme can deliver the modest spectral resolution required, with just two focusing optics, one of which is the spherical grating.

  13. Custom E-Learning Experiences: Working with Profiles for Multiple Content Sources Access and Adaptation

    ERIC Educational Resources Information Center

    Ferretti, Stefano; Roccetti, Marco; Salomoni, Paola; Mirri, Silvia

    2009-01-01

    It is a common belief that the problem of extracting learners' profiles to be used for delivering custom learning experiences is a closed case. Yet, practical solutions do not completely cope with the complex issue of capturing all the features of users, especially those of heterogeneous learners, who may have special needs or characteristics…

  14. Geologic Assessment of the Damage Zone from the Second Test at Source Physics Experiment-Nevada (SPE-N)

    SciTech Connect

    ,

    2012-09-18

    The National Center for Nuclear Security (NCNS), established by the U.S. Department of Energy, National Nuclear Security Administration, is conducting a series of explosive tests at the Nevada National Security Site (NNSS; formerly the Nevada Test Site) that are designed to increase the understanding of certain basic physical phenomena associated with underground explosions. These tests will aid in developing technologies that might be used to detect underground nuclear explosions in support of verification activities for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The initial NCNS project is a series of explosive tests, known collectively as the Source Physics Experiment at the NNSS (SPE-N), being conducted in granitic rocks at the Climax stock in northern Yucca Flat. The SPE-N test series is designed to study the generation and propagation of seismic waves. The data will be used to improve the predictive capability of calculational models for detecting and characterizing underground explosions. The first SPE-N test (SPE-N-1) was a “calibration” shot conducted in May 2011, using 100 kilograms (kg) of explosives at the depth of 54.9 meters (m) (180 feet [ft]) in the U-15n source hole. SPE-N-2 was conducted in October 2011, using 1,000 kg of explosives at the depth of 45.7 m (150 ft) in the same source hole. Following the SPE-N-2 test, the core hole U-15n#10 was drilled at an angle from the surface to intercept the SPE-N-2 shot point location to obtain information necessary to characterize the damage zone. The desire was to determine the position of the damage zone near the shot point, at least on the northeast side, where the core hole penetrated it. The three-dimensional shape and symmetry of the damage zone are unknown at this time. Rather than spherical in shape, the dimensions of the damage zone could be influenced by the natural fracture sets in the vicinity. Geologic characterization of the borehole included geophysical logging, a directional survey

  15. Synergy Between Experiments and Simulations in Laser and Beam-Driven Plasma Acceleration and Light Sources

    NASA Astrophysics Data System (ADS)

    Mori, Warren B.

    2015-11-01

    Computer simulations have been an integral part of plasma physics research since the early 1960s. Initially, they provided the ability to confirm and test linear and nonlinear theories in one-dimension. As simulation capabilities and computational power improved, then simulations were also used to test new ideas and applications of plasmas in multi-dimensions. As progress continued, simulations were also used to model experiments. Today computer simulations of plasmas are ubiquitously used to test new theories, understand complicated nonlinear phenomenon, model the full temporal and spatial scale of experiments, simulate parameters beyond the reach of current experiments, and test the performance of new devices before large capital expenditures are made to build them. In this talk I review the progress in simulations in a particular area of plasma physics: plasma based acceleration (PBA). In PBA a short laser pulse or particle beam propagates through long regions of plasma creating plasma wave wakefields on which electrons or positrons surf to high energies. In some cases the wakefields are highly nonlinear, involve three-dimensional effects, and the trajectories of plasma particles cross making it essential that fully kinetic and three-dimensional models are used. I will show how particle-in-cell (PIC) simulations were initially used to propose the basic idea of PBA in one dimension. I will review some of the dramatic progress in the experimental demonstration of PBA and show how this progress was dramatically helped by a synergy between experiments and full-scale multi-dimensional PIC simulations. This will include a review of how the capability of PIC simulation tools has improved. I will also touch on some recent progress on improvements to PIC simulations of PBA and discuss how these improvements may push the synergy further towards real time steering of experiments and start to end modeling of key components of a future linear collider or XFEL based on PBA

  16. Cord blood banking activity in Iran National Cord Blood Bank: a two years experience.

    PubMed

    Jamali, Mostafa; Atarodi, Kamran; Nakhlestani, Mozhdeh; Abolghasemi, Hasan; Sadegh, Hosein; Faranoosh, Mohammad; Golzade, Khadije; Fadai, Razieh; Niknam, Fereshte; Zarif, Mahin Nikougoftar

    2014-02-01

    Today umbilical cord blood (UCB) has known as a commonly used source of hematopoietic stem cells for allogeneic transplantation and many cord blood banks have been established around the world for collection and cryopreservation of cord blood units. Herein, we describe our experience at Iran National Cord Blood Bank (INCBB) during 2 years of activity. From November 2010 to 2012, UCBs were collected from 5 hospitals in Tehran. All the collection, processing, testing, cryopreservation and storage procedures were done according to standard operation procedures. Total nucleated cells (TNC) count, viability test, CD34+ cell count, colony forming unit (CFU) assay, screening tests and HLA typing were done on all banked units. Within 3770 collected units, only 32.9% fulfilled banking criteria. The mean volume of units was 105.2 ml and after volume reduction the mean of TNC, viability, CD34+ cells and CFUs was 10.76×10(8), 95.2%, 2.99×10(6) and 7.1×10(5), respectively. One unit was transplanted at Dec 2012 to a 5-year old patient with five of six HLA compatibilities. In our country banking of UCB is new and high rate of hematopoietic stem cell transplants needs expanding CB banks capacity to find more matching units, optimization of methods and sharing experiences to improve biological characterization of units.

  17. Experiences with active damping and impedance-matching compensators

    NASA Astrophysics Data System (ADS)

    Betros, Robert S.; Alvarez, Oscar S.; Bronowicki, Allen J.

    1993-09-01

    TRW has been implementing active damping compensators on smart structures for the past five years. Since that time there have been numerous publications on the use of impedance matching techniques for structural damping augmentation. The idea of impedance matching compensators came about by considering the flow of power in a structure undergoing vibration. The goal of these compensators is to electronically dissipate as much of this flowing power as possible. This paper shows the performance of impedance matching compensators used in smart structures to be comparable to that of active damping compensators. Theoretical comparisons between active damping and impedance matching methods are made using PZT actuators and sensors. The effects of these collocated and non-collocated PZT sensors and actuators on the types of signals they sense and actuate are investigated. A method for automatically synthesizing impedance matching compensators is presented. Problems with implementing broad band active damping and impedance matching compensators on standard Digital Signal Processing (DSP) chips are discussed. Simulations and measurements that compare the performance of active damping and impedance matching techniques for a lightly damped cantilevered beam are shown.

  18. fMRI activation patterns in an analytic reasoning task: consistency with EEG source localization

    NASA Astrophysics Data System (ADS)

    Li, Bian; Vasanta, Kalyana C.; O'Boyle, Michael; Baker, Mary C.; Nutter, Brian; Mitra, Sunanda

    2010-03-01

    Functional magnetic resonance imaging (fMRI) is used to model brain activation patterns associated with various perceptual and cognitive processes as reflected by the hemodynamic (BOLD) response. While many sensory and motor tasks are associated with relatively simple activation patterns in localized regions, higher-order cognitive tasks may produce activity in many different brain areas involving complex neural circuitry. We applied a recently proposed probabilistic independent component analysis technique (PICA) to determine the true dimensionality of the fMRI data and used EEG localization to identify the common activated patterns (mapped as Brodmann areas) associated with a complex cognitive task like analytic reasoning. Our preliminary study suggests that a hybrid GLM/PICA analysis may reveal additional regions of activation (beyond simple GLM) that are consistent with electroencephalography (EEG) source localization patterns.

  19. Chemical Explosion Experiments to Improve Nuclear Test Monitoring [Developing a New Paradigm for Nuclear Test Monitoring with the Source Physics Experiments (SPE)

    SciTech Connect

    Snelson, Catherine M.; Abbott, Robert E.; Broome, Scott T.; Mellors, Robert J.; Patton, Howard J.; Sussman, Aviva J.; Townsend, Margaret J.; Walter, William R.

    2013-07-02

    A series of chemical explosions, called the Source Physics Experiments (SPE), is being conducted under the auspices of the U.S. Department of Energy’s National Nuclear Security Administration (NNSA) to develop a new more physics-based paradigm for nuclear test monitoring. Currently, monitoring relies on semi-empirical models to discriminate explosions from earthquakes and to estimate key parameters such as yield. While these models have been highly successful monitoring established test sites, there is concern that future tests could occur in media and at scale depths of burial outside of our empirical experience. This is highlighted by North Korean tests, which exhibit poor performance of a reliable discriminant, mb:Ms (Selby et al., 2012), possibly due to source emplacement and differences in seismic responses for nascent and established test sites. The goal of SPE is to replace these semi-empirical relationships with numerical techniques grounded in a physical basis and thus applicable to any geologic setting or depth.

  20. Chemical Explosion Experiments to Improve Nuclear Test Monitoring [Developing a New Paradigm for Nuclear Test Monitoring with the Source Physics Experiments (SPE)

    DOE PAGES

    Snelson, Catherine M.; Abbott, Robert E.; Broome, Scott T.; ...

    2013-07-02

    A series of chemical explosions, called the Source Physics Experiments (SPE), is being conducted under the auspices of the U.S. Department of Energy’s National Nuclear Security Administration (NNSA) to develop a new more physics-based paradigm for nuclear test monitoring. Currently, monitoring relies on semi-empirical models to discriminate explosions from earthquakes and to estimate key parameters such as yield. While these models have been highly successful monitoring established test sites, there is concern that future tests could occur in media and at scale depths of burial outside of our empirical experience. This is highlighted by North Korean tests, which exhibit poormore » performance of a reliable discriminant, mb:Ms (Selby et al., 2012), possibly due to source emplacement and differences in seismic responses for nascent and established test sites. The goal of SPE is to replace these semi-empirical relationships with numerical techniques grounded in a physical basis and thus applicable to any geologic setting or depth.« less

  1. Intracerebral propagation of interictal activity in partial epilepsy: implications for source localisation.

    PubMed Central

    Alarcon, G; Guy, C N; Binnie, C D; Walker, S R; Elwes, R D; Polkey, C E

    1994-01-01

    than the ictal onset zone and their interictal propagation to the surface is independent of their capacity to trigger seizures. It is concluded that: (1) the deep-to-surface ratios of electromagnetic fields from deep sources are extremely low on the scalp; (2) single dipoles or a limited number of dipoles are not adequate for surgical assessment; (3) the correct localisation of the onset of interictal activity does not necessarily imply the onset of seizures in the region or in the same hemisphere. It is suggested that, until volume conduction and neurophysiological propagation can be distinguished, semiempirical correlations between symptomatology, surgical outcome, and detailed presurgical modeling of the neocortical projection patterns by combined MEG, EEG, and MRI could be more fruitful than source localization with unrealistic source models. PMID:8163992

  2. Carbon and Nitrogen Sources Influence Tricalcium Phosphate Solubilization and Extracellular Phosphatase Activity by Talaromyces flavus.

    PubMed

    Stefanoni Rubio, P J; Godoy, M S; Della Mónica, I F; Pettinari, M J; Godeas, A M; Scervino, J M

    2016-01-01

    The aim of this work was to study phosphate (P) solubilization (and the processes involved in this event) by Talaromyces flavus (BAFC 3125) as a function of carbon and/or nitrogen sources. P solubilization was evaluated in NBRIP media supplemented with different carbon (glucose, sorbitol, sucrose, and fructose) and nitrogen (L-asparagine, urea, ammonium sulfate (AS), and ammonium nitrate (AN) combinations. The highest P solubilization was related to the highest organic acid production (especially gluconic acid) and pH drop for those treatments where glucose was present. Also P solubilization was higher when an inorganic nitrogen source was supplemented to the media when compared to an organic one. Although not being present an organic P source, phosphatase activity was observed. This shows that P mineralization and P solubilization can occur simultaneously, and that P mineralization is not induced by the enzyme substrate. The combination that showed highest P solubilization was for AN-glucose. The highest acid phosphatase activity was for AS-fructose, while for alkaline phosphatase were for AS-fructose and AN-fructose. Acid phosphatase activity was higher than alkaline. P solubilization and phosphatase activity (acid and alkaline) were influenced by the different carbon-nitrogen combinations. A better understanding of phosphate-solubilizing fungi could bring a better use of soil P.

  3. An innovative Yb-based ultrafast deep ultraviolet source for time-resolved photoemission experiments

    SciTech Connect

    Boschini, F.; Hedayat, H.; Dallera, C.; Cerullo, G.; Farinello, P.; Manzoni, C.; Carpene, E.; Magrez, A.; Berger, H.

    2014-12-15

    Time- and angle-resolved photoemission spectroscopy is a powerful technique to study ultrafast electronic dynamics in solids. Here, an innovative optical setup based on a 100-kHz Yb laser source is presented. Exploiting non-collinear optical parametric amplification and sum-frequency generation, ultrashort pump (hν = 1.82 eV) and ultraviolet probe (hν = 6.05 eV) pulses are generated. Overall temporal and instrumental energy resolutions of, respectively, 85 fs and 50 meV are obtained. Time- and angle-resolved measurements on BiTeI semiconductor are presented to show the capabilities of the setup.

  4. X-ray holographic microscopy experiments at the Brookhaven synchrotron light source

    SciTech Connect

    Howells, M.R.; Iarocci, M.; Kenney, J.; Kirz, J.; Rarback, H.

    1983-01-01

    Soft x-ray holographic microscopy is discussed from an experimental point of view. Three series of measurements have been carried out using the Brookhaven 750 MeV storage ring as an x-ray source. Young slits fringes, Gabor (in line) holograms and various data pertaining to the soft x-ray performance of photographic plates are reported. The measurements are discussed in terms of the technique for recording them and the experimental limitations in effect. Some discussion is also given of the issues involved in reconstruction using visible light.

  5. An innovative Yb-based ultrafast deep ultraviolet source for time-resolved photoemission experiments.

    PubMed

    Boschini, F; Hedayat, H; Dallera, C; Farinello, P; Manzoni, C; Magrez, A; Berger, H; Cerullo, G; Carpene, E

    2014-12-01

    Time- and angle-resolved photoemission spectroscopy is a powerful technique to study ultrafast electronic dynamics in solids. Here, an innovative optical setup based on a 100-kHz Yb laser source is presented. Exploiting non-collinear optical parametric amplification and sum-frequency generation, ultrashort pump (hν = 1.82 eV) and ultraviolet probe (hν = 6.05 eV) pulses are generated. Overall temporal and instrumental energy resolutions of, respectively, 85 fs and 50 meV are obtained. Time- and angle-resolved measurements on BiTeI semiconductor are presented to show the capabilities of the setup.

  6. Follow-up fuel plate stability experiments and analyses for the Advanced Neutron Source

    SciTech Connect

    Swinson, W.F.; Battiste, R.L.; Luttrell, C.R.; Yahr, G.T.

    1993-11-01

    The reactor for the planned Advanced Neutron Source uses closely spaced plates cooled by heavy water flowing through narrow channels. Two sets of tests were performed on the upper and lower fuel plates for the structural response of the fuel plates to the required high coolant flow velocities. This report contains the data from the second round of tests. Results and conclusions from all of the tests are also included in this report. The tests were done using light water on full-scale epoxy models, and through model theory, the results were related to the prototype plates, which are aluminum-clad aluminum/uranium silicide involute-shaped plates.

  7. EXPERIENCES FROM THE SOURCE-TERM ANALYSIS OF A LOW AND INTERMEDIATE LEVEL RADWASTE DISPOSAL FACILITY

    SciTech Connect

    Park,Jin Beak; Park, Joo-Wan; Lee, Eun-Young; Kim, Chang-Lak

    2003-02-27

    Enhancement of a computer code SAGE for evaluation of the Korean concept for a LILW waste disposal facility is discussed. Several features of source term analysis are embedded into SAGE to analyze: (1) effects of degradation mode of an engineered barrier, (2) effects of dispersion phenomena in the unsaturated zone and (3) effects of time dependent sorption coefficient in the unsaturated zone. IAEA's Vault Safety Case (VSC) approach is used to demonstrate the ability of this assessment code. Results of MASCOT are used for comparison purposes. These enhancements of the safety assessment code, SAGE, can contribute to realistic evaluation of the Korean concept of the LILW disposal project in the near future.

  8. Developmental changes in infant brain activity during naturalistic social experiences.

    PubMed

    Jones, Emily J H; Venema, Kaitlin; Lowy, Rachel; Earl, Rachel K; Webb, Sara Jane

    2015-11-01

    Between 6 and 12 months, typically developing infants undergo a socio-cognitive "revolution." The Interactive Specialization (IS) theory of brain development predicts that these behavioral changes will be underpinned by developmental increases in the power and topographic extent of socially selective cortical responses. To test this hypothesis, we used EEG to examine developmental changes in cortical selectivity for ecologically valid dynamic social versus non-social stimuli in a large cohort of 6- and 12-month-old infants. Consistent with the Interactive Specialization model, results showed that differences in EEG Θ activity between social and non-social stimuli became more pronounced and widespread with age. Differences in EEG activity were most clearly elicited by a live naturalistic interaction, suggesting that measuring brain activity in ecologically valid contexts is central to mapping social brain development in infancy.

  9. Active Noise Control Experiments using Sound Energy Flu

    NASA Astrophysics Data System (ADS)

    Krause, Uli

    2015-03-01

    This paper reports on the latest results concerning the active noise control approach using net flow of acoustic energy. The test set-up consists of two loudspeakers simulating the engine noise and two smaller loudspeakers which belong to the active noise system. The system is completed by two acceleration sensors and one microphone per loudspeaker. The microphones are located in the near sound field of the loudspeakers. The control algorithm including the update equation of the feed-forward controller is introduced. Numerical simulations are performed with a comparison to a state of the art method minimising the radiated sound power. The proposed approach is experimentally validated.

  10. Apollo experience report: Assessment of metabolic expenditures. [extravehicular activity

    NASA Technical Reports Server (NTRS)

    Waligora, J. M.; Hawkins, W. R.; Humbert, G. F.; Nelson, L. J.; Vogel, S. J.; Kuznetz, L. H.

    1975-01-01

    A significant effort was made to assess the metabolic expenditure for extravehicular activity on the lunar surface. After evaluation of the real-time data available to the flight controller during extravehicular activity, three independent methods of metabolic assessment were chosen based on the relationship between heart rate and metabolic production, between oxygen consumption and metabolic production, and between the thermodynamics of the liquid-cooled garment and metabolic production. The metabolic assessment procedure is analyzed and discussed. Real-time use of this information by the Apollo flight surgeon is discussed. Results and analyses of the Apollo missions and comments concerning future applications are included.

  11. Measurement of Organic and Inorganic Chemical Tracers for Source Apportionment of Tropospheric Aerosols Collected During the ACE-Asia Experiment

    NASA Astrophysics Data System (ADS)

    Schauer, J. J.; Park, J.; Duvall, R.; Bae, M.; Shafer, M. M.; Chuang, P.; Chuang, P.; Kim, Y. J.

    2001-12-01

    Naturally occurring dust and anthropogenic air pollutants are important contributors to tropospheric aerosols and impact air quality and the radiative balance of the Earth's atmosphere. In order to better understand the relationship between the origin, chemical composition and ultimate impact of Asian aerosols on climate forcing, aerosol samples were collected as part of the ACE-Asia experiment for detailed chemical analysis. Atmospheric particulate matter samples were collected from March 27, 2001 through May 6, 2001 at the ACE-Asia ground station located on Cheju Island, Korea. During this period, this region is impacted by anthropogenic air pollution emissions from highly urbanized region of Asia and by desert dust originating from northeastern Asia. As part of the experiment, atmospheric particulate matter samplers were also collected in urban and desert locations in Asia that represent regional sources of particulate matter in Asia. Size resolved aerosol samples were analyzed for trace metals by using microwave assisted-acid digestion and ICP-MS analysis, speciated organic compounds using solvent extraction and GC-MS analysis, as well as soluble ions and elemental and organic carbon (ECOC). These measurements provide fingerprints for source apportionment of the atmospheric particulate matter samples collected at the Cheju Island sampling site. The use of these chemical tracers for apportionment of wind-driven long range transported desert dust, local crustal derived dust, biogenically and anthropogenically derived sulfate, specific urban combustion source, and fossil fuel combustion will be presented.

  12. Influences of influent carbon source on extracellular polymeric substances (EPS) and physicochemical properties of activated sludge.

    PubMed

    Ye, Fenxia; Peng, Ge; Li, Ying

    2011-08-01

    It is necessary to understand the bioflocculation, settling and dewatering characteristics in the activated sludge process in order to establish more efficient operational strategies. The influences of carbon source on the extracellular polymeric substances (EPS) and flocculation, settling and dewatering properties of the activated sludge were investigated. Laboratory-scale completely mixed activated sludge processes were used to grow the activated sludge with different carbon sources of starch, glucose and sodium acetate. The sludge fed with acetate had highest loosely bound EPS (LB-EPS) and that fed with starch lowest. The amount of tightly bound EPS (TB-EPS), protein content in LB-EPS, polysaccharide content and protein contents in TB-EPS, were independent of the influent carbon source. The polysaccharide content in LB-EPS of the activated sludge fed with sodium acetate was lower slightly than those of starch and glucose. The sludge also had a nearly consistent flocs size and the sludge volume index (SVI) value. ESS content of the sludge fed with sodium acetate was higher initially, although it was similar to those fed with glucose and starch finally. However, the specific resistance to filtration and normalized capillary suction time fluctuated first, but finally were stable at around 5.0×10(8)mkg(-1) and 3.5 s Lg(-1) SS, respectively. Only the protein content in LB-EPS weakly correlated with the flocs size and SVI of the activated sludge. But there was no correlation between any other EPS contents or components and the physicochemical properties of the activated sludge.

  13. Transient desorption of water vapor - A potential source of error in upper atmosphere rocket experiments

    NASA Technical Reports Server (NTRS)

    Kendall, B. R. F.; Weeks, J. O.

    1974-01-01

    Results of measurements of the outgassing rates of samples of materials and surface finishes used on the outer skins of rocket-borne experiment packages in simulated rocket ascents. The results showed outgassing rates for anodized aluminum in the second minute of flight which are two to three orders of magnitude higher than those given in typical tables of outgassing rates. The measured rates for aluminum with chromate conversion surface coatings were also abnormally high. These abnormally high initial rates fell quickly after about five to ten minutes to values comparable with those in the published literature. It is concluded that anodized and chromate conversion coatings on the aluminum outer surfaces of a sounding rocket experiment package will cause gross distortion of the true water vapor environment.

  14. A new activated primary tank developed for recovering carbon source and its application.

    PubMed

    Jin, Pengkang; Wang, Xianbao; Zhang, Qionghua; Wang, Xiaochang; Ngo, Huu Hao; Yang, Lei

    2016-01-01

    A novel activated primary tank process (APT) was developed for recovering carbon source by fermentation and elutriation of primary sludge. The effects of solids retention time (SRT), elutriation intensity (G) and return sludge ratio (RSR) on this recovery were evaluated in a pilot scale reactor. Results indicated that SRT significantly influenced carbon source recovery, and mechanical elutriation could promote soluble COD (SCOD) and VFA yields. The optimal conditions of APT were SRT=5d, G=152s(-1) and RSR=10%, SCOD and VFA production were 57.0mg/L and 21.7mg/L. Particulate organic matter in sludge was converted into SCOD and VFAs as fermentative bacteria were significantly enriched in APT. Moreover, the APT process was applied in a wastewater treatment plant to solve the problem of insufficient carbon source. The outcomes demonstrated that influent SCOD of biological tank increased by 31.1%, which improved the efficiency of removing nitrogen and phosphorus.

  15. EVIDENCE FOR INFRARED-FAINT RADIO SOURCES AS z > 1 RADIO-LOUD ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Huynh, Minh T.; Norris, Ray P.; Siana, Brian; Middelberg, Enno

    2010-02-10

    Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey which have no observable mid-infrared counterpart in the Spitzer Wide-area Infrared Extragalactic (SWIRE) survey. The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6-70 {mu}m) from a number of Legacy surveys. We report the detections of two IFRS sources in IRAC images. The non-detection of two other IFRSs allows us to constrain the source type. Detailed modeling of the spectral energy distribution of these objects shows that they are consistent with high-redshift (z {approx}> 1) active galactic nuclei.

  16. Carbon Rod Radiant Source for Blast/Fire Interaction Experiments: Proof of Concept and Design.

    DTIC Science & Technology

    1980-08-30

    Evaluation of the alternate candidates provided direction for a DD ’,rAN7, 1473 E=-ITION OF f NOv*53 is OINSOLETIE N\\/ 1I - proof of concept experiment...34 ....... .................... ... 54 B Bibliography .......... ...................... 73 List of Figures Figure Page I Comparison of Alternative Thermal... alternatives for further study. The alternatives selected were (1) gaseous flames seeded with metal powder oxidants or inert particulate radiators, (2

  17. Integrated Verification Experiment data collected as part of the Los Alamos National Laboratory's Source Region Program

    SciTech Connect

    Fitzgerald, T.J.; Carlos, R.C.; Argo, P.E.

    1993-01-21

    As part of the integrated verification experiment (IVE), we deployed a network of hf ionospheric sounders to detect the effects of acoustic waves generated by surface ground motion following underground nuclear tests at the Nevada Test Site. The network sampled up to four geographic locations in the ionosphere from almost directly overhead of the surface ground zero out to a horizontal range of 60 km. We present sample results for four of the IVEs: Misty Echo, Texarkana, Mineral Quarry, and Bexar.

  18. Effect of source-separated urine storage on estrogenic activity detected using bioluminescent yeast Saccharomyces cerevisiae.

    PubMed

    Jaatinen, Sanna; Kivistö, Anniina; Palmroth, Marja R T; Karp, Matti

    2016-09-01

    The objective was to demonstrate that a microbial whole cell biosensor, bioluminescent yeast, Saccharomyces cerevisiae (BMAEREluc/ERα) can be applied to detect overall estrogenic activity from fresh and stored human urine. The use of source-separated urine in agriculture removes a human originated estrogen source from wastewater influents, subsequently enabling nutrient recycling. Estrogenic activity in urine should be diminished prior to urine usage in agriculture in order to prevent its migration to soil. A storage period of 6 months is required for hygienic reasons; therefore, estrogenic activity monitoring is of interest. The method measured cumulative female hormone-like activity. Calibration curves were prepared for estrone, 17β-estradiol, 17α- ethinylestradiol and estriol. Estrogen concentrations of 0.29-29,640 μg L(-1) were detectable while limit of detection corresponded to 0.28-35 μg L(-1) of estrogens. The yeast sensor responded well to fresh and stored urine and gave high signals corresponding to 0.38-3,804 μg L(-1) of estrogens in different urine samples. Estrogenic activity decreased during storage, but was still higher than in fresh urine implying insufficient storage length. The biosensor was suitable for monitoring hormonal activity in urine and can be used in screening anthropogenic estrogen-like compounds interacting with the receptor.

  19. Investigating effectiveness of activated carbons of natural sources on various supercapacitors

    NASA Astrophysics Data System (ADS)

    Faisal, Md. Shahnewaz Sabit; Rahman, Muhammad M.; Asmatulu, Ramazan

    2016-04-01

    Activated carbon can be produced from natural sources, such as pistachio and acorn shells, which can be an inexpensive and sustainable sources of natural wastes for the energy storage devices, such as supercapacitors. The carbonaceous materials used in this study were carbonized at the temperatures of 700°C and 900°C after the stabilization process at 240°C for two hours. These shells showed approximately 60% carbon yield. Carbonized nutshells were chemically activated using1wt% potassium hydroxide (KOH). Activated carbon powders with polyvinylidene fluoride (PVdF) were used to construct carbon electrodes. A 1M of tetraethylammonium tetrafluoroborate (TEABF4) and propylene carbonate (PC) were used as electrolytes. Electrochemical techniques, such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used for the characterization of the supercapacitors. Scanning electron microscopy (SEM) was used to inspect the surface texture of the activated carbons. Activated pistachio shells carbonized at 700°C showed more porous surface texture than those carbonized at 900°C. Effects of the carbonization temperatures were studied for their electrochemical characteristics. The shells carbonized at 700°C showed better electrochemical characteristics compared to those carbonized at 900°C. The test results provided about 27,083 μF/g specific capacitance at a scan rate of 10mV/s. This study showed promising results for using these activated carbons produced from the natural wastes for supercapacitor applications.

  20. Source-term experiment STEP-3 simulating a PWR severe station blackout

    SciTech Connect

    Simms, R.; Baker, L. Jr.; Ritzman, R.L.

    1987-01-01

    For a severe pressurized water reactor accident that leads to a loss of feedwater to the stream generators, such as might occur in a station blackout, fission product decay heating causes a water boil-off. Without effective decay heat removal, the fuel elements will be uncovered. Eventually, steam will oxidize the overheated cladding. The noble gases and volatile fission products, such as cesium and iodine, that are major contributors to the radiological source term will be released from the damaged fuel shortly after cladding failure. The accident environment when these volatile fission products escape was simulated in STEP-3 using four fuel elements from the Belgonucleaire BR3 reactor. The primary objective was to examine the releases in samples collected as close to the test zone as possible. In this paper, an analysis of the temperatures and hydrogen generation is compared with the measurements. The analysis is needed to estimate releases and characterize conditions at the source for studies of fission product transport.