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1

Recent Beam Developments with the LBNL 14GHz AECR-U Ion Source  

Microsoft Academic Search

A radial sputter probe has been developed for the AECR-U as an additional method of producing metal ion beams. Negative voltage is applied to the probe to incite collisions with target atoms, thereby sputtering material into the plasma. The sputter probe is positioned through one of the 6 radial access slots between the permanent hexapole structure of the AECR-U. The

M. L. Galloway; D. Leitner; C. M. Lyneis; W. Cornelius

2

The LBL advanced light source  

SciTech Connect

The LBL Advanced Light Source (ALS) will be a third generation synchrotron radiation facility. It is based on a low emittance 1--2 GeV electron storage ring (natural radial emittance <10 nm-rad), optimized to produce extremely bright beams of electromagnetic radiation (in the energy range from a few eV to around one keV) from insertion devices known as undulators. The storage ring is fed from an injection system consisting of a 50 MeV linac and a 1.5 GeV, 1 Hz, booster synchrotron, which can fill the ring to its normal operating current (400 mA, multibunch, or 7.6 mA, single bunch) in a few minutes. As well as high brightness (which is a consequence of the very small electron beam emittance in the storage ring), the design emphasizes: picosecond timestructure, laserlike coherence properties, narrow bandwidth, and long beam lifetimes. The more familiar continuous synchrotron radiation spectrum will be available from bending magnets and from wiggler magnets. This paper gives a general description of the ALS and discusses some of the significant design issues associated with the low emittance storage ring that is required for this new facility. 7 refs., 6 figs., 2 tabs.

Jackson, A.; Chattopadhyay, S.; Keller, R.; Kim, C.; Nishimura, H.; Selph, F.; Zisman, M.

1988-06-01

3

Performance of the LBL ECR ion source  

SciTech Connect

The LBL Electron Cyclotron Resonance (ECR) ion source in test operation since January 1984 has produced a wide variety of high charge state ion beams suitable for injection into the 88-Inch Cyclotron. Two recent developments have dramatically improved the capability of the ECR source. The first development was the production of metallic ions. The intensities of aluminum ions produced were 36, 22, 10, and .065 e..mu..A for charge states 6, 7, 8, and 11, respectively. Calcium ion intensities were 36, 31, 4.6, and 0.20 e..mu..A for charge states 8, 9, 12, and 14, respectively. The second development was the replacement of the sextupole magnet used in of all other high charge state ECR sources with an octupole structure. This modification resulted in a dramatic improvement in the intensities of the high charge state beams and a significant upward shift in the charge state distribution (C.S.D.). The ECR-octupole or OCTIGUN has produced 89, 52, 9, and 2.5 e..mu..A of Ar/sup 8,9,11,12+/ and 21, 10, and 0.34 e..mu..A of Kr/sup 10,14,18+/, respectively. For the high charge states of argon and krypton the improvement gained by using the octupole is typically a factor of 5 to 10.

Lyneis, C.M.

1984-10-01

4

Vacuum system for the LBL Advanced Light Source (ALS)  

SciTech Connect

A 1.5 to 1.9 GeV synchrotron light source is being built at LBL. The vacuum system is designed to permit most synchrotron photons to escape the electron channel and be absorbed in an antechamber. The gas generated by the photons hitting the absorbers in the antechambers will be pumped by titanium sublimation pumps located directly under the absorbers. The electron channel and the antechamber are connected by a 10-mm-high slot that offers good electrodynamic isolation of the two chambers of frequencies affecting the store electron orbit. Twelve 10-meter-long vessels constitute the vacuum chambers for all the lattice magnets. Each chamber will be machined from two thick plates of 5083-H321 aluminum and welded at the perimeter. Machining both the inside and outside of the vacuum chamber permits the use of complex and accurate surfaces. The use of thick plates allows flanges to be machined directly into the wall of each chamber, thus avoiding much welding. 1 ref., 3 figs.

Kennedy, K.; Henderson, T.; Meneghetti, J. (Lawrence Berkeley Lab., CA (USA))

1989-03-01

5

Vacuum system for the LBL advanced light source (ALS)  

SciTech Connect

A 1.5 to 1.9 GeV synchrotron light source is being built at LBL. The vacuum system is designed to permit all synchrotron photons on the median plane to escape the electron channel and go into an antechamber through a 10 mm high slot. This slot offers effective RF isolation between the electron duct and the antechamber. All unused synchrotron photons within a few mrad of the median plane will be stopped by 96 nearly horizontal absorbers located in the antechamber. The gas, generated by the photons hitting the absorbers, will be directed down to reactive titanium surfaces. Twelve 10 meter long vessels constitute the vacuum chambers for all the lattice magnets. Each chamber will be machined from two thick plates of 5083-H321 aluminum and welded at the perimeter. The nominal wall thickness of the vacuum chamber is 40 mm, which makes it possible to machine a flange into the chamber without the use of welding. 5 refs., 5 figs.

Kennedy, K.

1988-05-01

6

Characterization of the plasma-switch interaction in the LBL HIF ion source  

SciTech Connect

A new way to characterize the performance of the LBL HIF ion source has been found. In the LBL source, ions are drawn from an arc-generated plasma reservoir in which the electrons are confined by a negative-biased switch'' mesh. Stagnation of the plasma is prevented by absorption of the excess ion flow on this mesh. The ion beam is generated by an external negative voltage that provides Child-Langmuir extraction of the ions through the switch mesh. We elucidate the physics requirements of the source and deduce switch mesh parameters needed for successful operation. 2 refs., 2 figs.

Hewett, D.W. (Lawrence Livermore National Lab., CA (USA)); Rutkowski, H.L. (Lawrence Berkeley Lab., CA (USA))

1990-12-10

7

Power Supply for the Lbl 40 Kev Neutral Beam Source.  

National Technical Information Service (NTIS)

A 20 keV, 50 Amp, 10 millisec pulse D exp 0 Neutral Beam Source at the Lawrence Berkeley Laboratory that serves as the prototype for 12 similar sources now in operation on the 2XIIB Mirror Machine at the Lawrence Livermore Laboratory has been recently upg...

W. R. Baker M. L. Fitzgerald V. J. Honey

1975-01-01

8

Scientific program of the Advanced Light Source at LBL  

SciTech Connect

Construction of the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory is nearing completion, with operation as a US Department of Energy national user facility scheduled to begin in the spring of 1993. Based on a low-emittance, 1.5-GeV electron storage ring with 10 long straight sections available for insertion devices and, initially, 24 bend-magnet ports, the ALS will be a third-generation source of soft x-ray and ultraviolet (collectively, the XUV) synchrotron radiation. Experimental facilities (insertion devices, beamlines, and end stations) will be developed and operated by participating research teams working with the ALS staff. The ability to exploit the high spectral brightness of the ALS was the main criterion for PRT selection. In the XUV spectral regions served by the ALS, a major benefit of high brightness will be the ability to achieve spatial resolution in the neighborhood of 200 angstroms in x-ray microscopy and holography and in spatially resolved spectroscopy. Other beneficiaries of high brightness include very-high-resolution spectroscopy, spectroscopy of dilute species, diffraction from very small samples, and time-resolved spectroscopy and diffraction.

Robinson, A.L.; Schlachter, A.S.

1991-10-01

9

H/sup -/ ion source scaling studies at LBL  

SciTech Connect

Four experiments are reported. Constant arc voltage operation was compared with constant arc current operation over a similar range of plasma density. The higher arc voltage required in the constant arc current operation produced more H/sup -/, but it was at the expense of an even larger increase in the accelerated electron current. A comparison of different magnetic filter locations showed the highest accelerated H/sup -/ and the lowest e/sup -/ content at the closest filter location. Beam-forming electrode aperture comparison for round apertures from 2mm to 10mm diameters and a 11 x 27 mm oval slot showed a decreasing H/sup -/ and e/sup -/ with increasing aperture area. Increasing accelerator voltage produced an increasing plasma potential and electron temperature and decreasing electron density in the exit chamber of the plasma source.

Lietzke, A.F.; Hauck, C.A.

1986-10-01

10

Ground motion measurements at the LBL Light Source site, the Bevatron and at SLAC  

SciTech Connect

This report describes the technique for measuring ground motion at the site of the 1.0 to 2.0 GeV Synchrotron Radiation Facility which was known as the Advanced Light Source (in 1983 when the measurements were taken). The results of ground motion measurements at the Light Source site at Building 6 at LBL are presented. As comparison, ground motion measurements were made at the Byerly Tunnel, the Bevatron, Blackberry Canyon, and SLAC at the Spear Ring. Ground Motion at the Light Source site was measured in a band from 4 to 100 Hz. The measured noise is primarily local in origin and is not easily transported through LBL soils. The background ground motion is for the most part less than 0.1 microns. Localized truck traffic near Building 6 and the operation of the cranes in the building can result in local ground motions of a micron or more for short periods of time. The background motion at Building 6 is between 1 and 2 orders of magnitude higher than ground motion in a quiet seismic tunnel, which is representative of quiet sites worldwide. The magnitude of the ground motions at SLAC and the Bevatron are comparable to ground motions measured at the Building 6 Light Source site. However, the frequency signature of each site is very different.

Green, M.A.; Majer, E.I.; More, V.D.; O'Connell, D.R.; Shilling, R.C.

1986-12-01

11

Radioactive Beams Using the AECR-U and the 88-Inch Cyclotron  

SciTech Connect

The high ionization efficiency of an Electron Cyclotron Resonance (ECR) ion source combined with the mass resolution of a cyclotron is ideal for the generation of some ISOL-type radioactive ion beams (RIBs). In two separate projects at the 88-Inch Cyclotron at LBNL - BEARS and the Recyclotron - we have developed techniques to efficiently ionize and accelerate beams of gaseous species of 11C (t1/2 = 20 min), 14,15O (t1/2 = 70 sec, 2 min) and 76,79Kr (t1/2 = 14,35 hours). Measurements of the ionization efficiency and hold-up times are discussed, along with issues of source contamination and poisoning encountered in running both RIBs and high-intensity stable beam experiments using the same ion source, the LBNL AECR-U. Methods used to tune clean RIBs through the Cyclotron with high efficiency are also discussed, including the use and limitations of analog beams.

McMahan, M.A.; Leitner, D.; Powell, J.; Silver, C. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

2005-03-15

12

First experimental results from IBM/TENN/TULANE/LLNL/LBL undulator beamline at the advanced light source  

SciTech Connect

The IBM/TENN/TULANE/LLNL/LBL Beamline 8.0 at the advanced light source combining a 5.0 cm, 89 period undulator with a high-throughput, high-resolution spherical grating monochromator, provides a powerful excitation source over a spectral range of 70--1200 eV for surface physics and material science research. The beamline progress and the first experimental results obtained with a fluorescence end station on graphite and titanium oxides are presented here. The dispersive features in K emission spectra of graphite excited near threshold, and found a clear relationship between them and graphite band structure are observed. The monochromator is operated at a resolving power of roughly 2000, while the spectrometer has a resolving power of 400 for these fluorescence experiments.

Jia, J.J.; Callcott, T.A. (Department of Physics, University of Tennessee, Knoxville, Tennessee 37996 (United States)); Yurkas, J.; Ellis, A.W.; Himpsel, F.J. (IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States)); Samant, M.G.; Stoehr, J. (IBM Almaden Research Center, San Jose, California 95120 (United States)); Ederer, D.L. (Department of Physics, Tulane University, New Orleans, Louisiana 70118 (United States)); Carlisle, J.A.; Hudson, E.A.; Terminello, L.J. (Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)); Shuh, D.K.; Perera, R.C.C. (Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States))

1995-02-01

13

Power supply for the LBL 40 keV neutral beam source  

SciTech Connect

A 20 keV, 50 Amp, 10 millisec pulse D$sup 0$ Neutral Beam Source at the Lawrence Berkeley Laboratory that serves as the prototype for 12 similar sources now in operation on the 2XIIB Mirror Machine at the Lawrence Livermore Laboratory has been recently upgraded to operate at 40 keV. The system of electronically regulated and controlled power supplies that drive the Source is described. (auth)

Baker, W.R.; Fitzgerald, M.L.; Honey, V.J.

1975-11-01

14

Low emittance 0.8A K{sup +} ion source for the LBL Induction Linac System Experiment (ILSE)  

SciTech Connect

A high current injector for heavy ion fusion presently under construction at Lawrence Berkeley Laboratory requires large sources of up to 17 an in diameter and total potassium ion current of 790 mA with a low normalized transverse emittance of less than 0.5 mm-mr. A 1 in. diameter hot alumina silicate (zeolite) source was fabricated and tested in the injector setup of SBTE, an existing facility at LBL. Initial measurements showed a maximum space charge limited ion current of 95 mA. The corresponding density of 19 mA/cm{sup 2} was limited by the source diode optics and not be the source emission. The density required for the high current injector is 4 mA/cm{sup 2}. The normalized emittance was measured to be 0.06 mm-mrad, corresponding to a transverse temperature of 0.2 eV. Non-destructive life tests showed that the source can be operated under continuous operating conditions of the high current injector for more than a month (twenty eight-hour days, with 1 {mu}s long pulses at 1 Hz). D.C. destructive life tests showed that {approximately}30% of the total stored K can be ionized and extracted, allowing, in principle, for years of operation for the high current injector. Furthermore, we shall describe the extension of the fabricating technique to large diameter sources (up to 17 cm) and report on measured ion emission performance, measured surface temperature uniformity and heating power considerations.

Eylon, S.; Henestroza, E.; Chupp, W.W.; Yu, S.

1993-05-01

15

Single particle dynamics in the LBL 1-2 GeV synchrotron radiation source in the presence of magnetic imperfections, magnet displacement errors and insertion devices  

SciTech Connect

The effects arising from sources of perturbing fields that can be predicted in advance of construction of the LBL 1 to 2 GeV Synchrotron Radiation Source are investigated. These include field errors (systematic and random) introduced through magnet design and finite construction tolerances; a random quadrupole component arising from a finite closed orbit distortion in the sextupoles; and the intrinsic focusing and nonlinear fields associated with the insertion devices (undulators and wigglers). (LEW)

Jackson, A.; Nishimura, H.

1987-03-01

16

The LBL 1-2 GeV synchrotron radiation source  

SciTech Connect

The design of the 1 to 2 GeV Synchrotron Radiation Source to be built at the Lawrence Berkeley Laboratory is described. The goal of this facility is to provide very high brightness photon beams in the ultraviolet and soft x-ray regions. The photon energy range to be served is from 0.5 eV to 10 keV, with the brightest beams available in the 1 eV to 1 keV interval. For time-resolved experiments, beam pulses of a few tens of picoseconds will be available. Emphasis will be on the use of undulators and wigglers to produce high quality, intense beams. Initially, four of the former and one of the latter devices will be installed, with six long straight sections left open for future installations. In addition, provision is being made for 48 beamlines from bending magnets. The storage ring is optimized for operation at 1.5 GeV, with a maximum energy of 1.9 GeV. The injection system includes a 1.5 GeV booster synchrotron for full energy injection at the nominal operating energy of the storage ring. Filling time for the maximum storage ring intensity of 400 mA is about 2 minutes, and beam lifetime will be about 6 hours. Attention has been given to the extraordinary requirements for beam stability, and to the need to independently control photon beam alignment. Typical rms beam size in insertion regions is 201 ..mu..m horizontal, and 38 ..mu..m vertical. The manner in which this design achieves very high spectral brightness from undulators and wigglers, while maintaining a modest value for the beam current, will be described. Primarily, this requires that the design of the lattice, the arrangement of bending magnets, focusing quadrupoles and straight sections, be done with this in mind.

Selph, F.B.

1987-06-01

17

75 FR 64691 - Information Collection; Land Between The Lakes (LBL) Communication Effectiveness Study  

Federal Register 2010, 2011, 2012, 2013

...and other information sources on...if LBL's communication efforts are...regional tourism industry...requested information from LBL...measuring the effectiveness of LBL's communication effort...information technology. All...

2010-10-20

18

LBL computing newsletter  

SciTech Connect

The LBL Computing Newsletter for July, 1985 summarizes information relating to the use of LBL computing facilities. Topics covered include 8600 VMS printers, electronic mail, CSA2, DECnet and several other systems. A section on personal computers is included which discusses discounts on computers and software.

Not Available

1985-07-01

19

Acute Exacerbation of Chronic Rhinosinusitis (AECRS) with Orbital Complications in an Atrophic Rhinitis Patient: A Mere Co-incidence?  

PubMed Central

Recurrent Acute Exacerbations of Chronic Rhinosinusitis (AECRS) in a setting of atrophic rhinitis are perplexing clinical situations. While either may act as the primary factor, repeated inflammation in a vessel-poor atrophied tissue is unusual. Progressive mucosal degeneration, vascularity and the effect of bacterial colonization are the factors suggested to play an important role for the pathobiogenesis of the co-existence of the two diseases. Through presentation of a case, a brief attempt has been made here to explore the temporal relationship between rhinosinusitis and atrophic rhinitis; in the process, other noteworthy features of the patient have also been highlighted.

Dutta, Mainak; Ghatak, Soumya

2013-01-01

20

Design, fabrication, and calibration of curved integral coils for measuring transfer function, uniformity, and effective length of LBL ALS (Lawrence Berkeley Laboratory Advanced Light Source) Booster Dipole Magnets  

SciTech Connect

A matched pair of curved integral coils has been designed, fabricated and calibrated at Lawrence Berkeley Laboratory for measuring Advanced Light Source (ALS) Booster Dipole Magnets. Distinctive fabrication and calibration techniques are described. The use of multifilar magnet wire in fabrication integral search coils is described. Procedures used and results of AC and DC measurements of transfer function, effective length and uniformity of the prototype booster dipole magnet are presented in companion papers. 8 refs.

Green, M.I.; Nelson, D.; Marks, S.; Gee, B.; Wong, W.; Meneghetti, J.

1989-03-01

21

Multi-beam injector development at LBL  

SciTech Connect

LBL is developing a multi-beam injector that will be used for scaled accelerator experiments related to Heavy Ion Fusion. The device will produce sixteen 0.5 Amp beams of C+ at 2 MeV energy. The carbon arc source has been developed to the point where the emittance is within a factor of four of the design target. Modelling of the source behavior to find ways to reduce the emittance is discussed. Source lifetime and reliability is also of paramount importance to us and data regarding the lifetime and failure modes of different source configurations is discussed. One half of the accelerating column has been constructed and tested at high voltage. One beam experiments in this half column are underway. The second half of the column is being built and the transition 2 MV experiments should begin soon. In addition to beam and source performance we also discuss the controls for the injector and the electronics associated with the source and current injection. 3 refs., 2 figs.

Rutkowski, H.L.; Faltens, A.; Brodzik, D.A.; Johnson, R.M.; Pike, C.D.; Vanecek, D.L. (Lawrence Berkeley Lab., CA (United States)); Humphries, S. Jr. (New Mexico Univ., Albuquerque, NM (United States)); Meyer, E.A. (Los Alamos National Lab., NM (United States)); Hewett, D.W. (Lawrence Livermore National Lab., CA (United States))

1990-06-01

22

Multiple beam induction linac research at LBL  

SciTech Connect

We present results of progress on the LBL multiple beam induction linac experiment (MBE-4). This machine models the accelerator physics of the electric-focused portion of a driver for heavy ion inertial confinement fusion. Four beams of cesium ions are accelerated in common through twenty four induction gaps while being separately focused in individual electrostatic AG focusing channels. Early experiments have demonstrated current amplification in the linac, from 10 mA to 90 mA per beam. This is achieved both by acceleration (from 200 keV to 1 MeV) and by carefully controlled bunch compression. Recent experiments have concentrated on studies of beams extracted from an ion source which produces 5 mA cesium beams at emittances near 0.03 {pi} mm-mrad (normalized). Experiments and theory show a growth of emittance (by about a factor of 2) as these beams are accelerated through the linac. Results of recent measurements of the transverse emittance behavior of these strongly space-charge-dominated ion beams are reviewed and compared with theory. 9 refs., 3 figs.

Garvey, T.; Eylon, S.; Fessenden, T.J.; Hahn, K.; Henestroza, E.; Keefe, D.

1990-06-01

23

Recent Developments in High Charge State Heavy Ion BEAMS at the LBL 88-Inch Cyclotron.  

National Technical Information Service (NTIS)

Recent advances in design and operation of the internal PIG sources at the LBL 88-Inch Cyclotron have led to the development of high charge state (0.4 < or approx. = to Q/A < or approx. = to 0.5) heavy ion beams between lithium and neon with energies 20 <...

R. A. Gough D. J. Clark L. R. Glasgow

1978-01-01

24

Guidelines for generators of hazardous chemical waste at LBL and Guidelines for generators of radioactive and mixed waste at LBL  

SciTech Connect

The purpose of this document is to provide the acceptance criteria for the transfer of hazardous chemical, radioactive, and mixed waste to Lawrence Berkeley Laboratory's (LBL) Hazardous Waste Handling Facility (HWHF). These guidelines describe how a generator of wastes can meet LBL's acceptance criteria for hazardous chemical, radioactive, and mixed waste. 9 figs.

Not Available

1991-07-01

25

SSC Quadrupole Magnet Performance at LBL  

SciTech Connect

Lawrence Berkeley Laboratory (LBL) contracted to design, construct, and test four short (1m) models and six full-size (5m) models of the Superconducting Super Collider (SSC) main-ring 5 meter focusing quadrupole magnet (211 Tesla/meter). The training performance of these magnets is summarized. Magnets were tested in a horizontal boiling helium (1 Atm) cryostat. The magnetic, strain-gage and training responses to two thermal cycles were measured. The quadrupole gradient, and relative multipole purity were determined from Fourier analysis of the rotating coil signals. Magnetic and strain-gage measurements were taken on-the-fly. The voltage-tap data was analyzed to determine quench-origin and propagation characteristics. Quench-training proceeded at 4.3K until a plateau was achieved or sub-cooling (2.5K) was used to accelerate the training process. The early short (1m) magnets were also trained at 1.8K (10kA) to help identify potential weak areas. The MIITs were calculated to compare various magnet protection methods. Except for modest training above the anticipated SSC operating point, the magnets performed very well and proved to be self-protecting. Some design flaws were identified and corrected. The last two 1 m models and all the 5m models have been reinstalled in cryostats at the SSC Laboratory, retested and used to achieve various milestones in their program.

Lietzke, A.F.; Barale, P.; Benjegerdes, r.; Caspi, S.; Cortella, J.; Dell'Orco, D.; Gilbert, W.; Green, M.I.; Mirk, K.; Peters, C.; Scalan, R.; Taylor, C.E.; Wandesforde, A.

1992-10-01

26

LAYER BY LAYER (LbL) SELF-ASSEMBLY STRATEGY AND ITS APPLICATIONS  

Microsoft Academic Search

This report reviews the technique of layer-by-layer (LbL) self-assembly, in particular cases involving electrostatic interactions between thin film monolayers. LbL self- assembly is used in a variety of different applications, two of which discussed in the report are LbL MEMS and LbL protein multilayers. In the fabrication of LbL MEMS, multilayers of polymer-clay-magnetite nanocrystal are deposited via photolithographic steps on

A. Z. Cheng; R. Swaminathan

27

Guidelines for generators of hazardous chemical waste at LBL and guidelines for generators of radioactive and mixed waste at LBL  

SciTech Connect

In part one of this document the Governing Documents and Definitions sections provide general guidelines and regulations applying to the handling of hazardous chemical wastes. The remaining sections provide details on how you can prepare your waste properly for transport and disposal. They are correlated with the steps you must take to properly prepare your waste for pickup. The purpose of the second part of this document is to provide the acceptance criteria for the transfer of radioactive and mixed waste to LBL's Hazardous Waste Handling Facility (HWHF). These guidelines describe how you, as a generator of radioactive or mixed waste, can meet LBL's acceptance criteria for radioactive and mixed waste.

Not Available

1991-09-01

28

The LBL 55-meter spherical grating monochromator at SSRL (Stanford Synchrotron Radiation Laboratory)  

SciTech Connect

The Lawrence Berkeley Laboratory 55-m spherical grating monochromator (SGM) beamline is located as a branch line of the 54-pole wiggler/undulator at the Stanford Synchrotron Radiation Laboratory (SSRL). It was designed and constructed by LBL's Center for X-Ray Optics and the engineering staff of LBL's Advanced Light Source with the cooperation and assistance of the research group of David Shirley at LBL and the staff of SSRL. The main goals of the project were to test the SGM concept and to develop a capability for designing and building a water-cooled mirror and grating capability in anticipation of the ALS. A water-cooled plane mirror deflects the beam horizontally, taking in general a small fraction of the flux from the 54-pole insertion device. This mirror is a brazed assembly of Glidcop (a proprietary alumina-dispersion-strengthened copper alloy) and OFHC copper. Its surface was finished in polished electroless nickel, then overcoated with gold as all optics in the beamline are overcoated. Next in the line is a fused silica toroid which focuses the SPEAR source vertically onto the entrance slit of the monochromator and horizontally onto the nominal position of the exit slit, in the manner of Rense and Violett. The magnification factors are 0.3x vertically and 0.7x horizontally. The monochromator is a Rowland-circle design; both slits move on large granite-based slides that maintain flatness of travel to {plus minus}2 {mu}m in peak-to-peak variation from straightness.

McKinney, W.R.; Howells, M.R.; Lauritzen, T.; Chin, J.; DiGennaro, R.; Fong, E.; Gath, W.; Guigli, J.; Hogrefe, H.; Meneghetti, J.; Plate, D.; Heimann, P.A.; Terminello, L.; Ji, Z.; Shirley, D. (Lawrence Berkeley Lab., CA (USA)); Senf, S. (Stanford Univ., CA (USA). Stanford Synchrotron Radiation Lab.)

1989-08-01

29

Guidelines for generators of hazardous chemical waste at LBL and guidelines for generators of radioactive and mixed waste at LBL. Revision 2  

SciTech Connect

The purpose of this document is to provide the acceptance criteria for the transfer of hazardous chemical waste to LBL`s Hazardous Waste Handling Facility (HWHF). Hazardous chemical waste is a necessary byproduct of LBL`s research and technical support activities. This waste must be handled properly if LBL is to operate safely and provide adequate protection to staff and the environment. These guidelines describe how you, as a generator of hazardous chemical waste, can meet LBL`s acceptance criteria for hazardous chemical waste.

Not Available

1993-10-01

30

LbL Films as Reservoirs for Bioactive Molecules  

Microsoft Academic Search

\\u000a This review presents recent progress in utilizing polymeric films made by the layer-by-layer (LbL) technique (so-called multilayered\\u000a films) as reservoirs for hosting and releasing bioactive molecules. This relatively new technique is distinguished by its\\u000a high modularity and structural control at the nanometer level, giving polymeric surface films with tuneable physicochemical\\u000a properties. A significant increase in research activities regarding the bioapplications

D. Volodkin; A. Skirtach; H. Möhwald

31

Design of the extraction system and beamline of the superconducting ECR ion source VENUS  

SciTech Connect

A new, very high magnetic field superconducting ECR ion source, VENUS, is under construction at the LBNL 88-Inch Cyclotron [1,2]. The paper describes the VENUS extraction system and discusses the ion beam formation in the strong axial magnetic field (3 T) of the ECR ion source. Emittance values as expected from theory, which assumes a uniform plasma density across the plasma outlet hole, are compared with actual measurements from the AECR-U ion source. Results indicate that highly charged heavier ions are concentrated on the source axis. They are extracted from an ''effective'' plasma outlet hole, whose smaller radius must be included in ion optics simulations.

Leitner, Matthaeus A.; Wutte, Daniela C.; Lyneis, Claude M.

2001-05-07

32

Initial operation of the LBL heavy ion RFQ  

SciTech Connect

The LBL heavy ion RFQ accelerator, a 200 MHz structure that accelerates an ion with q/A greater than or equal to 1/7 from 8.4 to 200 keV/n, has now passed all its acceptance tests. This machine is unique in several respects: it uses coupling rings between vanes to stablize the azimuthal field distribution, it incorporates a vane mounting system that simplifies vane alignment, it uses no end tuners or power distribution manifold, and it needs only one rf feed loop. The beam performance of this machine is reported in this paper.

Staples, J.; Gough, R.; Schneider, H.; Zajec, E.

1983-08-01

33

TPX Sb3SN Conductor Testing at LBL  

SciTech Connect

Two wire lengths (one from Supercon and one from IGC) were delivered for testing at the LBL Short-Sample Test Facility. Several samples of each wire-type were wound onto forms and reacted according to the requested prescriptions. Leads and voltage-tap wires were carefully attached after reaction according to standard LBL short-sample test procedures. Testing of some of the samples has been completed. Liquid helium immersion (4.2K) data was gathered over a limited range of magnetic fields (5-10T). Additional gas-cooled data was collected over a range of temperatures (1.8-14 K). Testing was interrupted when the test-magnet's persistent-switch-heater failed. Good sample-to-sample and retest repeatability was observed for the 4.2K data when it was checked. Temperature measruements on the Supercon samples used CGR's and revealed a disappointing, non-repeatable (pressure-dependent) temperature offset for the gas-cooled measurements. They also observed a systematic dependence upon magnetic-field strength. Changing to a second CGR did not help. The IGC sample used a Cernox-type resistor which showed negligible magnetic and pressure dependencies. Testing is expected to resume when the magnet is repaired.

Lietzke, A.F.; Scanlan, R.

1995-07-01

34

A fragment separator at LBL for beta-NMR experiment  

SciTech Connect

The Beam 44 fragment separator was built at the Bevalac of LBL for NMR studies of beta emitting nuclei. {sup 37}K, {sup 39}Ca, and {sup 43}Ti fragments originating from {sup 40}Ca and {sup 46}Ti primary beams were separated by the separator for NMR studies on these nuclei. Nuclear spin polarization was created in {sup 39}Ca and {sup 43}Ti using the tilted foil technique (TFT), and the magnetic moment of {sup 43}Ti was deduced. Fragment polarization was measured for {sup 37}K and {sup 39}Ca emitted to finite deflection angles. The Beam 44 fragment separator in combination with a proper polarization technique, such as TFT or fragment polarization, has been very effective for such NMR studies.

Matsuta, K.; Ozawa, A.; Nojiri, Y.; Minamisono, T.; Fukuda, M.; Kitagawa, A.; Ohtsubo, T.; Momota, S.; Fukuda, S.; Matsuo, Y.; Takechi, H.; Minami, I.; Sugimoto, K. [Osaka Univ., Toyonaka, Osaka, (Japan); Tanihata, I. [Riken, Inc., Wako, Saitama (Japan); Omata, K. [Tokyo Univ., Tanashi (Japan). Inst. for Nuclear Study; Shimoura, S. [Univ., of Tokyo, Bunkyo-ku, Tokyo, (Japan); Alonso, J.R.; Krebs, G.F.; Symons, T.J.M. [Lawrence Berkeley Lab., CA (United States)

1992-03-01

35

Scientific and statistical data management research at LBL  

SciTech Connect

This paper is a review of scientific and statistical data management research at LBL in recent years in the areas of: logical modeling and user interfaces, database operators, and physical organization and access methods. In the area of logical modeling and user interfaces we discuss: SUBJECT, a system for organizing multi-dimensional data, GUIDE, a graphical query system, and logical modeling of temporal data. In database operators we discuss sampling from relational databases, and transposition of compressed data. In the area of physical DB organization and access methods we discuss: header data compression, rearrangement of data arrays to enhance data compression, batched interpolation search, bit transposed file organization, techniques for controlling overflow from multi-dimensional data structures (e.g. grid files), and data structures for temporal data. 31 refs., 7 figs., 1 tab.

Olken, F.; Rotem, D.; Shoshani, A.; Wong, H.

1986-06-01

36

The 50 MeV Beam Test Facility at LBL  

SciTech Connect

A new beam line, expected to be built by September 1993, will transport the 50 MeV electron beam from the ALS LINAC into an experimental area to support various R&D activities in the Center for Beam Physics at LBL. A variety of experiments are planned involving the interaction of such a relativistic electron beam with plasmas (plasma focusing), laser beams (generation of femtosecond X-ray pulses) and electromagnetic cavities (Crab cavities etc....). The beam line is designed using the measured emittance and Twiss parameters of the ALS linac. It accommodates the different requirements of the various experiments on the electron beam properties (charge, energy, pulse length) and on the handling of the beam before and after the interaction point. Special attention has also been given to incorporate diagnostics for measuring the beam properties (such as the electron energy, bunch length and charge) needed in the interpretation of the experiments.

Leemans, W.; Behrsing, G.; Kim, K.J.; Krupnick, J.; Matuk, C.; Selph, F.; Chattopadhyay, S.

1993-05-01

37

Guidelines for Waste Accumulation Areas (WAAs) at LBL. Revision 1  

SciTech Connect

The purpose of this document is to set conditions for establishing and containing areas for the accumulation of hazardous waste at LBL. Areas designed for accumulation of these wastes for up to 90 days in quantities greater than 55 gallons (208 liters) of hazardous waste, one quart (0.946 liter) of extremely hazardous waste, or one quart (0.946 liter) of acutely hazardous waste are called Waste Accumulation Areas (WAAs). Areas designed for accumulation of wastes in smaller amounts are called Satellite Accumulation Areas (SAAs). This document provides guidelines for employee and organizational responsibilities for WAAs, constructing a WAA, storing waste in a WAA, operating and maintaining a WAA, and responding to spills in a WAA.

Not Available

1994-06-01

38

Comparison of measured and predicted infiltration using the LBL infiltration model  

Microsoft Academic Search

The LBL infiltration model was developed in 1980; since that time many simultaneous measurements of infiltration and weather have been made allowing comparison of predictions with measured infiltration. This report presents the LBL model as it currently exists and summarizes infiltration measurements and corresponding predictions. These measurements include both long-term and short-term data taken in houses with climates ranging from

M. H. Sherman; M. P. Modera

1984-01-01

39

Design overview of a highly stable infrared free electron laser at LBL  

SciTech Connect

An infrared free electron laser (IRFEL) is being designed for the Chemical Dynamics Research Laboratory (CDRL) at LBL. The FEL is based on a 50 MeV RF linac operating in synchronization to the Advanced Light Source (ALS), and will produce intense (100 {mu}J per micropulse), narrow bandwidth (narrower than 0.1%) radiation between 3 {mu} and 50 {mu}. In the design, we pay particular attention to the FEL stability issues and require that the fluctuations in electron beam energy and in timing be less then 0.05% and 0.1 ps respectively. The FEL spectrum can then be stabilized to about 10{sup {minus}3}, or if grating is used, to 10{sup {minus}4}. We discuss various sources of fluctuations in the gun, the bunchers and the accelerator sections, as well as the feedback and feedforward schemes to reduce these fluctuations. The accelerator structure is chosen to be of the side coupled, standing wave type for easier control. The beam transport is made isochronous to avoid the coupling between the energy and the timing fluctuations. 12 refs., 1 fig.

Kim, K.J.; Berz, M.; Chattopadhyay, S.; Gough, R.; Kim, C.; Kung, A.H.; Xie, M. (Lawrence Berkeley Lab., CA (USA)); Edighoffer, J. (Pulse Sciences, Inc., San Leandro, CA (USA)); Stein, W. (Industrial Radiation, Inc., Los Alamos, NM (USA))

1990-11-01

40

Detailed Examination of the LBL (Lawrence Berkeley Laboratory) Infiltration Model Using the Mobile Infiltration Test Unit.  

National Technical Information Service (NTIS)

The LBL infiltration model is a simplified method for combining weather information with air tightness to calculate residential air infiltration. In this report, we compare infiltration-model predictions with data collected by our Mobile Infiltration Test...

M. P. Modera M. H. Sherman P. A. Levin

1983-01-01

41

pH-indicators doped polysaccharide LbL coatings for hazardous gases optical sensing.  

PubMed

Sensitive layer-by-layer (LbL) coatings for optical detection of gaseous NH(3) and HCl were prepared by self-assembly of oppositely charged polysaccharides (chitosan and ?-carrageenan) followed by doping LbLs with pH-sensitive dyes - bromothymol blue (BTB) and Congo red (CR). It has been shown that CR, being an amphoteric dye, diffuses into LbL films regardless of the charge of the outermost polyelectrolyte layer, and the dye loading increases linearly with the LbL film thickness, whereas BTB diffuses into LbL films only when the outermost layer is positively charged, and linearity between dye loading and film thickness holds only up to 8-12 double layers (DLs) deposited. Formation of dye-doped LbL coatings at the surface of K(+)/Na(+) ion-exchanged glass has allowed fabrication of composite optical waveguide (OWG) gas sensor for detection of ammonia and hydrochloric acid vapors. The response time of BTB-doped composite OWG for ammonia detection was below 1s, and the detection limit was below 1 ppm. CR-doped OWG sensors have shown high sensitivity to HCl vapor but slow relaxation time (up to several hours for 12 DL LbL films). PMID:23218366

Mironenko, A Yu; Sergeev, A A; Voznesenskiy, S S; Marinin, D V; Bratskaya, S Yu

2013-01-30

42

Guidelines for generators of hazardous chemical waste at LBL and guidelines for generators of radioactive and mixed waste at LBL. Revision 1  

SciTech Connect

In part one of this document the Governing Documents and Definitions sections provide general guidelines and regulations applying to the handling of hazardous chemical wastes. The remaining sections provide details on how you can prepare your waste properly for transport and disposal. They are correlated with the steps you must take to properly prepare your waste for pickup. The purpose of the second part of this document is to provide the acceptance criteria for the transfer of radioactive and mixed waste to LBL`s Hazardous Waste Handling Facility (HWHF). These guidelines describe how you, as a generator of radioactive or mixed waste, can meet LBL`s acceptance criteria for radioactive and mixed waste.

Not Available

1991-09-01

43

LBL fabricated biopolymer-layered silicate based nanofibrous mats and their cell compatibility studies.  

PubMed

N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC) was synthesized from chitosan (CS). Organic rectorite (OREC) added into cellulose acetate (CA) was used to fabricate electrospun nanofibrous mats with improved thermal properties, as a result of depositing multilayers of the positively charged HTCC-OREC composites and the negatively charged sodium alginate (ALG) via layer-by-layer (LBL) technique. The morphology was affected by the number of deposition bilayers and the component of the outmost layer. Observed from the field emission scanning electron microscopy (FE-SEM) images, the LBL structured nanofibrous mats had much larger fiber sizes than CA-OREC nanofibrous mats. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) results further confirmed that HTCC-OREC was assembled on nanofibrous mats. Additionally, cell experiments and MTT results demonstrated that OREC had little effect on the cytotoxicity of LBL template, but obviously affected both the cytotoxicity and the cell compatibility of LBL structured mats when OREC was in the deposition films. PMID:22840026

Huang, Rong; Li, Yuejun; Zhou, Xue; Zhang, Qi; Jin, Huanguang; Zhao, Jiemin; Pan, Siyi; Deng, Hongbing

2012-10-01

44

The LBL (Lawrence Berkeley Laboratory) multiple beam experiments  

Microsoft Academic Search

The multiple-beam induction linac approach to a heavy ion driver for inertial confinement, fusion features continuous current amplification along the accelerator and a minimum of beam manipulations from source to pellet. Current amplification and bunch length control require careful shaping of the accelerating voltages. MBE-4 is designed as a four-beam induction linac that models much of the accelerator physics of

T. J. Fessenden; D. Keefe; C. Kim; H. Meuth; A. Warwick

1987-01-01

45

A new 14 GHz electron-cyclotron-resonance ion source (ECRIS) for the heavy ion accelerator facility ATLAS: a status report  

SciTech Connect

A new 14 GHz ECRIS has been designed and built over the last 2 years. The source, a modification of the Berkeley AECR, incorporates the latest results from ECR developments to produce intense beams of highly charged ions, i.e., an improved electron confinement with an axial magnetic mirror ratio of 3.5 and a radial magnetic field inside the plasma chamber of 1.0 T. The aluminium plasma chamber and extraction electrode as well as a biased disk on axis at the microwave injection side donate additional electrons to the plasma, making use of the large secondary electron yield from Al oxide. Slots in the plasma chamber allow for radial pumping which increases the AECR performance. The source will also be capable of additional ECR plasma heating using two frequencies simultaneously to increase the electron energy gain for producing high charge states. To be able to deliver usable intensities of the heaviest ion beams, the design will also allow for axial access for metal evaporation ovens and solid material samples using plasma sputtering. Main design goal is to produce several e{mu}A of U{sup 34+} in order to obtain Coulomb- barrier energies from ATLAS without further stripping.

Schlapp, M.; Vondrasek, R.C.; Szczech, J.; Billquist, P.J.; Pardo, R.C. [Argonne National Lab., IL (United States); Xie, Z.Q. [Lawrence Berkeley National Lab., CA (United States)

1996-11-01

46

Volume H/sup -/ ion production experiments at LBL  

SciTech Connect

H/sup -/ ions formed by volume processes have been extracted from a multicusp ion source. It is shown that a permanent magnet filter together with a small positive bias voltage on the plasma grid can produce a very significant reduction in electron drain as well as a sizable increase in H/sup -/ ions available for extraction. A further reduction in electron current is achieved by installing a pair of small magnets at the extraction aperture. An H/sup -/ ion current density of 38 mA/cm/sup 2/ was obtained with a discharge current of approximately 350 A. Different techniques to increase the H/sup -/ ion yield have also been investigated.

Leung, K.N.; Ehlers, K.W.

1983-11-01

47

Survey and Alighment for the ALS Project at LBL Berkeley  

SciTech Connect

The Advanced Light Source (ALS), now under construction at Lawrence Berkeley Laboratory, is a synchrotron radiation source of the third generation designed to produce extremely bright photon beams in the UV and soft X-ray regions. Its main accelerator components are a 1-1.9 GeV electron storage ring with 196.8 m circumference and 12 super-periods, a 1.5 GeV booster synchrotron with 75.0 m circumference and 4 super-periods, and a 50 MeV linac, as shown in Fig. 1. The storage ring has particularly tight positioning tolerances for lattice magnets and other components to assure the required operational characteristics. The general survey and alignment concept for the ALS is based on a network of fixed monuments installed in the building floor, to which all component positions are referred. Measurements include electronic distance measurements and separate sightings for horizontal and vertical directions, partially with automated electronic data capture. Most of the data processing is accomplished by running a customized version of PC-GEONET. It provides raw data storage, data reduction, and the calculation of adjusted coordinates, as well as an option for error analysis. PC-GEONET has also been used to establish an observation plan for the monuments and calculate their expected position accuracies, based on approximate coordinates. Additionally, for local survey tasks, the commercial software package ECDS is used. In this paper, the ALS survey and alignment strategy and techniques are presented and critically discussed. First experiences with the alignment of the linac and booster components are described.

Keller, R.; Lauritzen, T.; /LBL, Berkeley; Friedsam, H.; /SLAC

2005-08-12

48

The LBL (Lawrence Berkeley Laboratory) multiple beam experiments  

SciTech Connect

The multiple-beam induction linac approach to a heavy ion driver for inertial confinement, fusion features continuous current amplification along the accelerator and a minimum of beam manipulations from source to pellet. Current amplification and bunch length control require careful shaping of the accelerating voltages. MBE-4 is designed as a four-beam induction linac that models much of the accelerator physics of the electrostatically focused section of a significantly longer induction accelerator. Four space-charge-dominated Cs/sup +/ beams, initially about one meter in length at a current of 13 mA, are focused by electrostatic quadrupoles and accelerated in parallel from 200 to nearly 600 keV. The energy will reach approximately one MeV when the accelerator is complete. Experiments have proceeded in parallel with the construction of the apparatus which began in FY 85 and is now more than half complete. The results show a current amplification, so far, by a factor of 2.8 in good agreement with the longitudinal acceleration calculations.

Fessenden, T.J.; Keefe, D.; Kim, C.; Meuth, H.; Warwick, A.

1987-03-01

49

The Architecture and Biological Performance of Drug-Loaded LbL Nanoparticles  

PubMed Central

Layer-by-Layer (LbL) nanoparticles are an emerging class of therapeutic carriers that afford precise control over key design parameters that facilitate improved drug and carrier pharmacokinetics, and enhanced molecular-targeting capabilities. This paper advances the development of these systems by establishing them as drug carriers, with the means to control drug release in a systemic environment and retard particle clearance from circulation, promoting improved biodistribution of the drug-containing system. Using dual-fluorescent tracking in vivo, this work establishes a robust means of screening libraries of LbL systems generated, affording simultaneous resolution over persistence and biodistribution of both the drug and carrier following systemic administration of a single particle formulation. Employing a PLGA drug-containing core as a substrate for LbL deposition, a range of coated systems were fabricated to investigate the abilities of these films to stabilize drug for delivery as well as to improve the pharmacokinetics of both the drug and carrier. Significant reductions in liver accumulation were observed for different formulations of the layered architectures within the first 30 minutes of systemic circulation. LbL architectures diminished liver localization of the surrogate drug, cardiogreen, by 10–25% ID/g relative to native PLGA nanoparticles and modulated carrier accumulation in the liver >50% ID/g. Further, enhanced persistence of the drug was observed with the coated systems, significantly increasing the drug half-life from 2–3 minutes for free drug and 1.87h for the uncoated core to 4.17h and 4.54h for the coated systems. These systems provide an exciting, modular platform that improves the pharmacokinetic properties of the therapeutic, reduces bolus release of drug from nanoparticles, and enhances the safety and circulation half-life of the drug in vivo, proving them to be highly clinically-relevant and a promising approach for future development of molecularly-targeted and combination therapeutics.

Morton, Stephen; Poon, Zhiyong; Hammond, Paula

2014-01-01

50

Overview of the LBL\\/LLNL negative-ion-based neutral beam program  

Microsoft Academic Search

The LBL\\/LLNL negative-ion-based neutral beam development program and status are described. The emphasis has shifted in some details since the first symposium in 1977, but our overall objectives remain the same, namely, the development of megawatt d.c. injection systems. Previous emphasis was on a system in which the negative ions were produced by double charge exchange in sodium vapor. At

Pyle

1980-01-01

51

The LBL Advanced Light Source (ALS) transverse coupled-bunch feedback system: Recent commissioning results  

SciTech Connect

The ALS transverse coupled-bunch feedback system is described along with some recent commissioning results. Results presented include transfer function measurements, demonstrations of multi-bunch damping, and demonstrations of simultaneous transverse and longitudinal systems operation.

Barry, W.; Byrd, J.; Corlett, J.

1994-10-01

52

The effect of gas mixing and biased disc voltage on the preglow transient of electron cyclotron resonance ion source  

SciTech Connect

The effect of gas mixing and biased disc voltage on the preglow of electron cyclotron resonance ion source plasma has been studied with the AECR-U type 14 GHz ion source. It was found that gas mixing has a significant effect on the preglow. The extracted transient beam currents and efficiency of the heavier species increase, while the currents and efficiency of the lighter species decrease when gas mixing is applied. The effect of the biased disc was found to be pronounced in continuous operation mode in comparison to preglow. The data provide information on the time scales of the plasma processes explaining the effects of gas mixing and biased disc. The results also have implications on production of radioactive ion beams in preglow mode for the proposed Beta Beam neutrino factory.

Tarvainen, O.; Toivanen, V.; Komppula, J.; Kalvas, T.; Koivisto, H. [Department of Physics, University of Jyvaeskylae, Jyvaeskylae 40500 (Finland)

2012-02-15

53

Traversing Material Scales: Macroscale LBL-Assembled Nanocomposites with Microscale Inverted Colloidal Crystal Architecture.  

PubMed

The introduction of three-dimensional (3D) architecture to functional materials allows for the addition of unique characteristics such as special deformation patterns, negative Poison's ratio, negative thermal expansion, controlled biological interactions, and mass transport properties. It also aids in bridging the dimensional gap between layer-by-layer (LBL) assembled nanocomposites and macroscale applications while retaining the advantages of their nanoscale organization. Fabrication of 3D microscale features by traditional techniques are often restricted to a limited variety of materials and do not include hybrid organic-inorganic nanocomposites. This work describes a new method to synthesize macroscale materials with hierarchically controlled architecture by using LBL deposition in the voids of hexagonally packed arrays of uniform microspheres and can be potentially extended to a large variety of materials. Establishing systematic techniques to produce materials with hierarchical architecture involving nano-, micro-, and potentially millimeter scale features with fairly independent control at all levels, allows for the investigation of structural influences on material properties and for the development of new practical applications due to the unusual combinations of properties that can be achieved. PMID:22639491

Andres, Christine M; Fox, Mary L; Kotov, Nicholas A

2012-01-10

54

Direct-Write Maskless Lithography of LBL Nanocomposite Films and its Prospects for MEMS Technologies  

PubMed Central

Application of nanocomposites in MEMS, flexible electronics, and biomedical devices is likely to demonstrate new performance standards and resolve a number of difficult technical problems enabled by the unique combinations of electrical, optical, and mechanical properties. This study explores the possibility of making microscale nanocomposite patterns using the fusion of two highly versatile techniques: direct-write maskless UV patterning and layer-by-layer assembly (LBL). Together they can be applied to production of a wide variety of nanostructured coatings with complex patterns. Single-walled carbon nanotube (SWNT) and gold nanoparticle LBL nanocomposites assembled with chitosan (CH) were made into prototypical patterns such as concentric helices and bus-line-and-stimulation pads (BLASP) used in flexible antennas and neuroprosthetic devices. The spatial resolution of the technique was established with the standard line grids to be at least 1?m. Gold nanoparticle films revealed better accuracy and higher resolution in direct-write patterning than SWNT composites possibly due to the granular rather than fibrous nature of the composites. The conductivity of the patterned composites was 6.45×10?5 ?·m and 3.80×10?6 ?·m at 20°C for nanotube and nanoparticle composites, respectively; in both cases it exceeds electrical parameters of similar composites. Fundamental and technological prospects of nanocomposite MEMS devices in different areas including implantable biomedical, sensing, and optical devices are discussed.

Bai, Yongxiao; Ho, Szushen; Kotov, Nicholas A.

2012-01-01

55

Volume H{sup {minus}} ion source development at LAMPF  

SciTech Connect

One method of increasing the intensity of the LAMPF proton Storage Ring is to use a brighter H{sup {minus}} ion source. To develop such a source, the performance of the small LBL dipole filter and the BNL toroidal filter volume H{sup {minus}} sources are being investigated. Results of testing a new high-duty-factor design of the BNL toroidal filter volume source are discussed. Results of experiments to reduce the electron to H{sup {minus}} ratio and modulate the beam intensity in the small LBL source are presented.

York, R.L.; Tupa, D.; Swenson, D.R.; Damjanovich, R.

1993-06-01

56

LBL/UCSB /sup 76/Ge double beta decay experiment: first results  

SciTech Connect

A paper given at the IEEE Nuclear Science Symposium last year presented the scientific justification for this experiment and discussed the design of the detector system. At the present time two of the dual detector systems (i.e., four out of a final total of eight detectors) are operating in the complete active/passive shield in the low background laboratory at LBL. Early results (1620 h) of an experiment using two detectors yield a limit of 4 x 10/sup 22/ years (68% confidence) for the half life of the neutrinoless double beta decay (..beta beta../sub o nu/) of /sup 76/Ge. Although this experiment was carried out above ground, the result approaches those achieved by other groups in deep underground laboratories. Based on studies of the origins of background in our system, we hope to reach a limit of 3 x 10/sup 23/ years (or more) in a two month/four detector experiment to be carried out soon in an underground facility.

Goulding, F.S.; Cork, C.P.; Landis, D.A.; Luke, P.N.; Madden, N.W.; Malone, D.F.; Pehl, R.H.; Smith, A.R.; Caldwell, D.O.; Eisberg, R.M.

1984-10-01

57

Physics, Computer Science and Mathematics Division. Annual report, 1 January--31 December 1977. [LBL, 1977  

SciTech Connect

This annual report of the Physics, Computer Science and Mathematics Division describes the scientific research and other work carried out within the Division during 1977. The Division is concerned with work in experimental and theoretical physics, with computer science and applied mathematics, and with the operation of a computer center. The major physics research activity is in high-energy physics, although there is a relatively small program of medium-energy research. The High Energy Physics research program in the Physics Division is concerned with fundamental research which will enable man to comprehend the nature of the physical world. The major effort is now directed toward experiments with positron-electron colliding beam at PEP. The Medium Energy Physics program is concerned with research using mesons and nucleons to probe the properties of matter. This research is concerned with the study of nuclear structure, nuclear reactions, and the interactions between nuclei and electromagnetic radiation and mesons. The Computer Science and Applied Mathematics Department engages in research in a variety of computer science and mathematics disciplines. Work in computer science and applied mathematics includes construction of data bases, computer graphics, computational physics and data analysis, mathematical modeling, and mathematical analysis of differential and integral equations resulting from physical problems. The Computer Center provides large-scale computational support to LBL's scientific programs. Descriptions of the various activities are quite short; references to published results are given. 24 figures. (RWR)

Lepore, J.V. (ed.)

1977-01-01

58

Experimental reestablishment of red wolves (Canis rufus) on the Tennessee Valley Authority's Land Between the Lakes (LBL)  

SciTech Connect

For all practical purposes the red wolf (Canis rufus) is extirpated in its final range in southeast Texas and southwest Louisiana. Although the species can be preserved in captivity, the only means by which it can be preserved as a naturally occurring element of our national heritage is to reestablish viable populations within the wolf's historic range in the southeastern United States. This proposal outlines a suggested procedure for reestablishing red wolves at Land Between The Lakes (LBL) by initially releasing five adult mated pairs of animals on the area over a two-year period. Recommendations for additions, changes, and deletions to this proposal have been received from the Kentucky Department of Fish and Wildlife Resources, Tennessee Wildlife Resources Agency, other governmental agencies, and interested organizations and individuals in the surrounding area. This proposal includes information describing probable environmental impacts associated with the experimental reestablishment of red wolves at LBL. 39 references, 16 figures, 6 tables.

Carley, C.J.; Mechler, J.L.

1983-10-01

59

Effect of nano clay platelets and DNA on controlling the H-dimer of oxazine 4 perchlorate (OX4) in LbL film  

NASA Astrophysics Data System (ADS)

Oxazine 4 perchlorate (OX4) forms dimer even in aqueous solution. In layer-by-layer (LbL) film of OX4, dimeric sites predominate over monomeric sites. This results in the quenching of fluorescence intensity. This communication reports a study of the control of H-dimer of OX4 in LbL film by incorporating nano clay platelets. Influence of deoxyribonucleic acid molecules in controlling the H-dimeric sites of Ox4 in the LbL film has also been studied. UV-Vis absorption spectroscopic technique has been employed to study this effect. Atomic force microscopic image confirms the presence of nano clay platelets in the LbL film.

Bhattacharjee, J.; Hussain, S. A.; Bhattacharjee, D.

2014-02-01

60

Femtosecond X-ray generation through 90{sup o} Thomson scattering: Status of the LBL experiment  

SciTech Connect

Scattering of femotosecond laser pulses off a low energy relativistic electron beam at 90{sup o} offers the possibility to generate ultrashort X-ray pulses. Experiments are under preparation in the Beam Test Facility of the Center for Beam Physics at LBL to demonstrate the generation and detection of such pulses. The experiments involve a relativistic electron beam (tunable from 25-50 MeV) with a bunch length of 10 ps containing 1-2 nC, and an ultra short pulse (50-200 fs), high peak power (>2 TW) 0.8 {mu}m Ti:Al{sub 2}O{sub 3} laser system. The electron beam, focused down to about a 50 {mu}m waist size intersects the focused laser beam at 90{sup o}. The laser field acts as an electromagnetic undulator with strength K (quiver velocity of an electron normalized to the speed of light) for the relativistic electron beam, generating radiation up-shifted by 2{gamma}{sup 2}/(1+K{sup 2}/2) and a pulse length given by the overlapped interaction length in time of the laser beam and the electron beam. Here {gamma} is the usual Lorentz factor. Wavelength tuning will be accomplished in the experiment by generating wiggler strengths on the order of one as well as by electron beam energy tuning. For a 50 MeV electron beam and a laser beam focused to an intensity on the order of 10{sup 16} W/cm{sup 2}, the authors expect 10{sup 5} photons at 0.4 {angstrom} (10% bandwidth) in a cone angle of 6 mrad in a 170 fs pulse.

Leemans, W.; Schoenlein, R.; Chin, A.; Glover, E.; Conde, M.; Chattopadhyay, S.; Kim, K.J.; Shank, C.V.

1994-11-01

61

Proceedings of the 10th international workshop on ECR ion sources  

SciTech Connect

This report contains papers on the following topics: Recent Developments and Future Projects on ECR Ion Sources; Operation of the New KVI ECR Ion Source at 10 GHz; Operational Experience and Status of the INS SF-ECR Ion Source; Results of the New ECR4'' 14.5 GHz ECRIS; Preliminary Performance of the AECR; Experimental Study of the Parallel and Perpendicular Particle Losses from an ECRIS Plasma; Plasma Instability in Electron Cyclotron Resonance Heated Ion Sources; The Hyperbolic Energy Analyzer; Status of ECR Source Development; The New 10 GHz CAPRICE Source; First Operation of the Texas A M ECR Ion Source; Recent Developments of the RIKEN ECR Ion Sources; The 14 GHz CAPRICE Source; Characteristics and Potential Applications of an ORNL Microwave ECR Multicusp Plasma Ion Source; ECRIPAC: The Production and Acceleration of Multiply Charged Ions Using an ECR Plasma; ECR Source for the HHIRF Tandem Accelerator; Feasibility Studies for an ECR-Generated Plasma Stripper; Production of Ion Beams by using the ECR Plasmas Cathode; A Single Stage ECR Source for Efficient Production of Radioactive Ion Beams; The Single Staged ECR Source at the TRIUMF Isotope Separator TISOL; The Continuous Wave, Optically Pumped H{sup {minus}} Source; The H{sup +} ECR Source for the LAMPF Optically Pumped Polarized Ion Source; Present Status of the Warsaw CUSP ECR Ion Source; An ECR Source for Negative Ion Production; GYRAC-D: A Device for a 200 keV ECR Plasma Production and Accumulation; Status Report of the 14.4 GHZ ECR in Legnaro; Status of JYFL-ECRIS; Report on the Uppsala ECRIS Facility and Its Planned Use for Atomic Physics; A 10 GHz ECR Ion Source for Ion-Electron and Ion-Atom Collision Studies; and Status of the ORNL ECR Source Facility for Multicharged Ion Collision Research.

Meyer, F W; Kirkpatrick, M I [eds.

1991-01-01

62

Molecularly designed layer-by-layer (LbL) films to detect catechol using information visualization methods.  

PubMed

The control of molecular architectures has been exploited in layer-by-layer (LbL) films deposited on Au interdigitated electrodes, thus forming an electronic tongue (e-tongue) system that reached an unprecedented high sensitivity (down to 10(-12) M) in detecting catechol. Such high sensitivity was made possible upon using units containing the enzyme tyrosinase, which interacted specifically with catechol, and by processing impedance spectroscopy data with information visualization methods. These latter methods, including the parallel coordinates technique, were also useful for identifying the major contributors to the high distinguishing ability toward catechol. Among several film architectures tested, the most efficient had a tyrosinase layer deposited atop LbL films of alternating layers of dioctadecyldimethylammonium bromide (DODAB) and 1,2-dipalmitoyl-sn-3-glycero-fosfo-rac-(1-glycerol) (DPPG), viz., (DODAB/DPPG)5/DODAB/Tyr. The latter represents a more suitable medium for immobilizing tyrosinase when compared to conventional polyelectrolytes. Furthermore, the distinction was more effective at low frequencies where double-layer effects on the film/liquid sample dominate the electrical response. Because the optimization of film architectures based on information visualization is completely generic, the approach presented here may be extended to designing architectures for other types of applications in addition to sensing and biosensing. PMID:23356548

Aoki, Pedro H B; Alessio, Priscila; Furini, Leonardo N; Constantino, Carlos J L; Neves, Tácito T A T; Paulovich, Fernando V; de Oliveira, Maria Cristina F; Oliveira, Osvaldo N

2013-06-18

63

Development of ion beams for space effects testing using an ECR ion source  

NASA Astrophysics Data System (ADS)

At LBNL's 88-Inch Cyclotron and Berkeley Accelerator Space Effects (BASE) Facility, a range of ion beams at energies from 1 to 55 MeV/nucleon are used for radiation space effects testing. By bombarding a component with ion beams the radiation component of the space environment can be simulated and single event effects (SEEs) determined. The performance of electronic components used in space flight and high altitude aircraft can then be evaluated. The 88- Inch Cyclotron is coupled to the three electron cyclotron resonance ion sources (ECR, AECR-U, VENUS). These ion sources provide a variety of ion species, ranging from protons to heavy ions such as bismuth, for these tests. In particular the ion sources have been developed to provide "cocktails", a mixture of ions of similar mass-to-charge ratio, which can be simultaneously injected into the cyclotron, but selectively extracted from it. The ions differ in both their linear energy transfer (LET) deposited to the part and in their penetration depth into the tested part. The current heavy ion cocktails available are the 4.5, 10, 16, and 30 MeV per nucleon.

Benitez, Janilee; Hodgkinson, Adrian; Johnson, Mike; Loew, Tim; Lyneis, Claude; Phair, Larry

2013-04-01

64

Plasmodium falciparum synthetic LbL microparticle vaccine elicits protective neutralizing antibody and parasite-specific cellular immune responses  

PubMed Central

Epitopes of the circumsporozoite (CS) protein of Plasmodium falciparum, the most pathogenic species of the malaria parasite, have been shown to elicit protective immunity in experimental animals and human volunteers. The mechanisms of immunity include parasite-neutralizing antibodies that can inhibit parasite motility in the skin at the site of infection and in the bloodstream during transit to the hepatocyte host cell and also block interaction with host cell receptors on hepatocytes. In addition, specific CD4+ and CD8+ cellular mechanisms target the intracellular hepatic forms, thus preventing release of erythrocytic stage parasites from the infected hepatocyte and the ensuing blood stage cycle responsible for clinical disease. An innovative method for producing particle vaccines, layer-by-layer (LbL) fabrication of polypeptide films on solid CaCO3 cores, was used to produce synthetic malaria vaccines containing a tri-epitope CS peptide T1BT* comprising the antibody epitope of the CS repeat region (B) and two T-cell epitopes, the highly conserved T1 epitope and the universal epitope T*. Mice immunized with microparticles loaded with T1BT* peptide developed parasite-neutralizing antibodies and malaria-specific T-cell responses including cytotoxic effector T-cells. Protection from liver stage infection following challenge with live sporozoites from infected mosquitoes correlated with neutralizing antibody levels. Although some immunized mice with low or undetectable neutralizing antibodies were also protected, depletion of T-cells prior to challenge resulted in the majority of mice remaining resistant to challenge. In addition, mice immunized with microparticles bearing only T-cell epitopes were not protected, demonstrating that cellular immunity alone was not sufficient for protective immunity. Although the microparticles without adjuvant were immunogenic and protective, a simple modification with the lipopeptide TLR2 agonist Pam3Cys increased the potency and efficacy of the LbL vaccine candidate. This study demonstrates the potential of LbL particles as promising malaria vaccine candidates using the T1BT* epitopes from the P. falciparum CS protein.

Powell, Thomas J.; Tang, Jie; DeRome, Mary E.; Mitchell, Robert A.; Jacobs, Andrea; Deng, Yanhong; Palath, Naveen; Cardenas, Edwin; Boyd, James G.; Nardin, Elizabeth

2013-01-01

65

Influence of LbL surface modification on oxygen cross-over in self-assembled thin composite membranes  

NASA Astrophysics Data System (ADS)

The paper is concerned with the investigation of oxygen transport in layer-by-layer (LbL) self assembly of polystyrene sulfonic acid sodium salt (PSS) and polyallylamine hydrochloride (PAH) on Nafion membrane depending on the number of deposited bilayers, ion type within the multilayers and temperature. It is observed from SEM analysis that the polyelectrolyte layers growth on each side of Nafion membrane regularly. The oxygen permeability (P) of (PAH-PSS) 20 is 691 cm 3/(m 2 day bar) at 25 °C while P of pristine Nafion is 2329 cm 3/(m 2 day bar) at the same temperature. This significant reduction (70.3%) in gas permeability can be explained by the formation of LbL multilayers which both restrict the mobility of gas through the polymer matrix and adjust gas solubility properties in conjunction with ion-dipole interaction between the polar phase of Nafion and the secondary ammonium groups of PAH. (PAH/PSS) 20-Na + and (PAH/PSS) 20-H + exhibit 64.4% and 52.3% reduction in oxygen permittivity at 25 °C in comparison with the pristine Nafion ®117, respectively, while the proton conductivities of these membranes are 106.9 and 136.9 mS/cm. Promisingly, it is found that the membrane selectivity values ( ?) of all multilayered membranes in both H + and Na + form are much higher than that of perfluorosulfonated ionomer. The thickness of deposited bilayers dominates the diffusion and solubility properties of oxygen through the composite membrane while the major effect of surface hydrophilicity is not observed on oxygen permeability.

Y?lmaztürk, Serpil; Ercan, Nevra; Deligöz, Hüseyin

2012-01-01

66

The use of TOUGH2 for the LBL/USGS 3-dimensional site-scale model of Yucca Mountain, Nevada  

SciTech Connect

The three-dimensional site-scale numerical model o the unsaturated zone at Yucca Mountain is under continuous development and calibration through a collaborative effort between Lawrence Berkeley Laboratory (LBL) and the United States Geological Survey (USGS). The site-scale model covers an area of about 30 km{sup 2} and is bounded by major fault zones to the west (Solitario Canyon Fault), east (Bow Ridge Fault) and perhaps to the north by an unconfirmed fault (Yucca Wash Fault). The model consists of about 5,000 grid blocks (elements) with nearly 20,000 connections between them; the grid was designed to represent the most prevalent geological and hydro-geological features of the site including major faults, and layering and bedding of the hydro-geological units. Submodels are used to investigate specific hypotheses and their importance before incorporation into the three-dimensional site-scale model. The primary objectives of the three-dimensional site-scale model are to: (1) quantify moisture, gas and heat flows in the ambient conditions at Yucca Mountain, (2) help in guiding the site-characterization effort (primarily by USGS) in terms of additional data needs and to identify regions of the mountain where sufficient data have been collected, and (3) provide a reliable model of Yucca Mountain that is validated by repeated predictions of conditions in new boreboles and the ESF and has therefore the confidence of the public and scientific community. The computer code TOUGH2 developed by K. Pruess at LBL was used along with the three-dimensional site-scale model to generate these results. In this paper, we also describe the three-dimensional site-scale model emphasizing the numerical grid development, and then show some results in terms of moisture, gas and heat flow.

Bodvarsson, G.; Chen, G.; Haukwa, C.; Kwicklis, E.

1995-12-31

67

Surface immobilization of a tetra-ruthenium substituted polyoxometalate water oxidation catalyst through the employment of conducting polypyrrole and the layer-by-layer (LBL) technique.  

PubMed

A tetra Ru-substituted polyoxometalate Na10[{Ru4O4(OH)2(H2O)4}(?-SiW10O36)2] (Ru4POM) has been successfully immobilised onto glassy carbon electrodes and indium tin oxide (ITO) coated glass slides through the employment of a conducting polypyrrole matrix and the layer-by-layer (LBL) technique. The resulting Ru4POM doped polypyrrole films showed stable redox behavior associated with the Ru centres within the Ru4POM, whereas, the POM's tungsten-oxo redox centres were not accessible. The films showed pH dependent redox behavior within the pH range 2-5 whilst exhibiting excellent stability towards redox cycling. The layer-by-layer assembly was constructed onto poly(diallyldimethylammonium chloride) (PDDA) modified carbon electrodes by alternate depositions of Ru4POM and a Ru(II) metallodendrimer. The resulting Ru4POM assemblies showed stable redox behavior for the redox processes associated with Ru4POM in the pH range 2-5. The charge transfer resistance of the LBL films was calculated through AC-Impedance. Surface characterization of both the polymer and LBL Ru4POM films was carried out using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Initial investigations into the ability of the Ru4POM LBL films to electrocatalytically oxidise water at pH 7 have also been conducted. PMID:24758586

Anwar, Nargis; Sartorel, Andrea; Yaqub, Mustansara; Wearen, Kevin; Laffir, Fathima; Armstrong, Gordon; Dickinson, Calum; Bonchio, Marcella; McCormac, Timothy

2014-06-11

68

Design of the 3rd generation ECR ion source  

SciTech Connect

Development of the 3rd Generation ECR ion source has progressed from a concept described in the last ECR Ion Source Workshop to the fabrication of a full scale prototype superconducting magnet structure. The prototype consists of three solenoid coils and six race track coils with iron poles forming the sextupole. The design calls for mirror fields of 4 T at injection and 3 T at extraction and for a radial field strength at the wall of 2.4 T. The prototype magnet will be tested this spring in an existing vertical cryostat to determine its operating characteristics including maximum operating values, training characteristics and to study the interaction between the solenoid and sextupole coils. Design of the ECR plasma chamber includes aluminum walls to provide an enhanced source of cold electrons, up to three separate microwave feeds to allow simultaneous heating of the plasma electrons at 10, 14 and 18 GHz or at 6, 10 and 14 GHz. Water cooling of the plasma chamber walls and the injection and extraction plates is planned so that up to 10 kW of microwave power can be used without excessive heating of the chamber components. Experience with the AECR-U at LBNL shows that increasing the magnetic fields and using two frequency heating allows operation at lower neutral pressures and higher microwave power density. Both of these conditions are needed to produce very high charge states from elements with masses greater than xenon and the resulting higher energy, more intense heavy beams from the 88-Inch Cyclotron would provide new research opportunities.

Lyneis, C.M.; Xie, Z.Q.; Taylor, C.E.

1997-02-01

69

A new 14 GHz Electron-Cyclotron-Resonance Ion Source (ECRIS) for the Heavy Ion Accelerator Facility ATLAS  

SciTech Connect

A new 14 GHz Electron-Cyclotron-Resonance Ion Source (ECRIS) has been designed and built over the last two years. The source, which is a modification of the AECR at Berkeley, incorporates the latest results from ECR developments to produce intense beams of highly charged ions, i.e. an improved magnetic confinement of the plasma electrons. The aluminum plasma chamber and extraction electrode as well as a biased disk on axis at the microwave injection side donate additional electrons to the plasma, making use of the large secondary electron yield from aluminum oxide. The source will be capable of ECR plasma heating using two different frequencies simultaneously to increase the electron energy gain for the production of high charge states. To be able to deliver usable intensities of the heaviest ion beams, the design will also allow axial access for metal evaporation ovens and solid material samples using the plasma sputtering technique. The main design goal is to produce several e{mu}A of at least {sup 238}U{sup 34+} in order to accelerate the beam to coulomb-barrier energies without further stripping. First charge state distributions for {sup 16}0 and {sup 40}Ar have been measured.

Schlapp, M.; Vondrasek, R.C.; Szczech, J.; Billquist, P.J.; Pardo, R.C. [Argonne National Lab., IL (United States); Xie, Z.Q.; Lyneis, C.M. [Lawrence Berkeley National Lab., CA (United States); Harkewicz, R. [National Superconducting Cyclotron Lab., East Lansing, MI (United States)

1997-04-01

70

A new 14 GHz Electron-Cyclotron-Resonance Ion Source (ECRIS) for the heavy ion accelerator facility ATLAS  

SciTech Connect

A 14 GHz Electron-Cyclotron-Resonance Ion Source (ECRIS) has been designed and built at Argonne National Laboratory. The source is a modification of the AECR at Berkeley and incorporates the latest results from ECR developments to produce intense beams of highly charged ions, including an improved magnetic confinement of the plasma electrons with an axial mirror ratio of 3.5. The aluminum plasma chamber and extraction electrode as well as a biased disk on axis at the microwave injection side donates additional electrons to the plasma, making use of the large secondary electron yield from aluminum oxide. The source is capable of ECR plasma heating using two different frequencies simultaneously to increase the electron energy gain for the production of high charge states. The main design goal is to produce several e{mu}A of at least {sup 238}U{sup 35+} in order to accelerate the beam to coulomb-barrier energies without further stripping. First charge state distributions for gaseous elements have been measured and 210 e{mu}A {sup 16}O{sup 7+} has been achieved. A normalized 90% emittance from 0.1 to 0.2 {pi} mm{sm_bullet}mrad for krypton and oxygen beam has been found.

Schlapp, M.; Pardo, R.C.; Vondrasek, R.C.; Billquist, P.J.; Szczech, J. [and others

1997-11-01

71

Preliminary development of the LBL/USGS three-dimensional site-scale model of Yucca Mountain, Nevada  

SciTech Connect

A 3-D model of moisture flow within the unsaturated zone at Yucca Mountain is being developed at LBL in cooperation with USGS. This site-scale model covers an area of about 34 km{sup 2} and is bounded by major faults to the north, east, and west. The relatively coarse-grid model includes about 300 horizontal grid-blocks and 17 layers. Contour maps and isopach maps are presented defining different types of infiltration zones, and the spatial distribution of Tiva Canyon, Paintbrush, and Topopah Spring hydrogeological units. Matrix flow is approximated using the van Genuchten model, and the equivalent continuum approximation is used to account for fracture flow in the welded units. One-, two-, and three-dimensional simulations are conducted using the TOUGH2 computer program. Steady-state simulations are performed with various uniform and nonuniform infiltration rates; results are interpreted in terms of effect of fault characteristics on moisture flow distribution, and on the location and formation of preferential pathways.

Wittwer, C. [Bureau de Recherches Geologiques et Minieres (BRGM), 45 - Orleans (France). Dept. Geothermie et Hydroenergie; Chen, G.; Bodvarsson, G.S. [Lawrence Berkeley Lab., CA (United States); Chornack, M.; Flint, A.; Flint, L.; Kwicklis, E.; Spengler, R. [US Geologic Survey, Denver, CO (United States). Denver Federal Center

1995-06-01

72

An ion source upgrade for an axial injection based commercial cyclotron  

NASA Astrophysics Data System (ADS)

The TRIUMF H - volume-cusp ion source technology licensed by Dehnel Consulting Ltd ranges in output current from 1 to 15 mA with beam energies in the 22-30 keV range. For those Cyclone 30 cyclotrons installed with an early 1980's style Lawrence Berkeley Lab (LBL) volume-cusp ion source, an upgrade to a 5 mA TRIUMF H - volume-cusp ion source would pay dividends in terms of longer filament, filament post and ion source lens lifetime, as well as less eroded material build-up in the source. In addition, the 5 mA ion source would approximately double the beam current available to inject into the cyclotron while reducing the emittance by about a factor of four. The new system has the potential to significantly boost radioisotope production at Cyclone 30 facilities utilizing the older style LBL ion source.

Dehnel, M. P.; Stewart, T.; Roeder, M.; Le Du, K.

2005-12-01

73

Conductive Paper by LBL Assembly of PSS and ITO onto Wood Fibers and its Electrical Properties through Impedance Spectroscopy and I-AFM  

NASA Astrophysics Data System (ADS)

Conductive paper has been fabricated by layer-by-layer (LBL) assembly of polyelectrolytes and indium tin oxide (ITO) nanoparticles onto wood fibers, followed by traditional paper making method. The wood fibers were first coated with polyethyleneimine (PEI) and then LBL assembled with poly(sodium 4-styrenesulfonate) (PSS) and ITO for several bilayers. The AC electrical properties, measured for frequencies ranging from 0.01 Hz to 1 MHz, will be reported for the in-plane (IP) and through-the-thickness (TT) directions. With 10 bilayers of PSS/ITO assembly on wood fibers, the conductivity of as-prepared paper was improved by more than six orders of magnitude and reach to 5.2x10-6 S cm-1 in IP direction and 1.9x10-8 S cm-1 in TT direction. The percolation phenomenon of ITO nanoparticles through the handsheet in both directions was observed through current atomic force microscopy (I-AFM). By applying a bias voltage, either on one end of the paper stripes or on one side of the paper handsheet, the current can be detected on the other end of the paper stripes or on the other side of the paper handsheet. PEI can be used to modify the ITO suspension and significantly improve the LBL procedure. The mechanism of PEI modifying ITO colloidal suspension will be discussed.

Peng, Chunqing; Thio, Yonathan; Gerhardt, Rosario

2009-03-01

74

Synchrotron light source data book  

SciTech Connect

The ''Synchrotron Light Source Data Book'' is as its name implies a collection of data on existing and planned synchrotron light sources. The intention was to provide a compendium of tools for the design of electron storage rings as synchrotron radiation sources. The slant is toward the accelerator physicist as other booklets such as the X-ray Data Booklet, edited by D. Vaughan (LBL PUB-490), address the 'use' of synchrotron radiation. It is hoped that the booklet serves as a pocket sized reference to facilitate back of the envelope type calculations. It contains some useful formulae in 'practical units' and a brief description of many of the existing and planned light source lattices.

Murphy, J.

1989-01-01

75

Thermal and structural analysis of the LBL 10 x 40 cm long pulse accelerator and the 12 x 48 cm common long pulse accelerator for TFTR, doublet III-D, and MFTF-B  

SciTech Connect

Stress and deflection of the grid rails of the existing, Lawrence Berkeley Laboratory (LBL) designed, 10 x 40 cm Long Pulse (neutral beam) Accelerator (40LPA) and the expanded 12 x 48 cm version, Common Long Pulse Source (CLPS), have been computed for a series of assumed heat load distributions. The combined stress from self-constraint of thermal expansion and rail holder reaction forces has been calculated. A simplification of the gradient grid rail holder was analyzed and was found to work as well or better than the original 40LPA design under the most probable operating conditions. Heat flux non-uniformity over the rail surface for both accelerator designs was estimated from 40LPA grid calorimetry data for arc and beam extraction operation. The extrapolated total heat load per rail for the CLPS was less than the 1.2 kW value used in this analysis. Under worst case assumptions, the maximum equivalent stress in any of the molybdenum grid rails was less than 20% of yield. For the anticipated heat load distribution on the gradient grid, the predicted deflection of the grid rail meets the 0.0457 mm position tolerance except under extremely non-uniform heat loads.

Wells, R.P.

1985-11-01

76

Magnet power supplies for the Advanced Light Source  

SciTech Connect

The Lawrence Berkeley Laboratory (LBL) is building an Advanced Light Source (ALS) to produce synchrotron radiation. An electron linear accelerator, and a booster synchrotron are used to accelerate the electron beam to 1.5 GeV to fill the storage ring. This paper describes the power supplies used for the magnets in the booster and the storage ring and the interface requirements for computer control and monitoring the power supplies and magnet currents. 1 ref., 3 figs., 2 tabs.

Jackson, L.T.; Lutz, I.C.

1989-03-01

77

A high charge state multicusp ion source  

SciTech Connect

Attempts have been made to generate high charge state ion beams by employing a multicusp plasma source. Three experimental investigations have been performed at LBL and at GSI to study the charge state distributions and the emittance of the extracted beam. Results demonstrate that charge state as high as +7 can be obtained with argon or xenon plasmas. The brightness of a 11 mA xenon ion beam is found to be 26 A/({pi}-mm-mrad){sup 2}. 6 refs., 6 figs.

Leung, K.N.; Keller, R.

1989-06-01

78

Advances in metal ion sources  

SciTech Connect

Beams of metallic ion species can be produced by the ECR (electron cyclotron resonance) ion source and by the MEVVA (metal vapor vacuum arc) ion source. Although the ECR source is fundamentally a gaseous ion source, metal ion beams can be produced by introducing metallic feed material into the plasma discharge using a number of techniques. The ion charge states can be very high, which is a significant advantage to most applications. The MEVVA ion source, on the other hand, is specifically a metal ion source. It has produced metallic ion beams from virtually all the solid metallic elements at a current of typically hundreds of milliamperes; the ions produced are in general multiply ionized, but not as highly stripped as those generated in the ECR source. Although the MEVVA source at present operates in a pulsed mode with a low duty cycle (less than or equal to 1%), work is in progress to increase the duty cycle significantly. In this paper the operation and performance of the LBL ECR and MEVVA ion sources, with respect to metal ion generation, are described.

Brown, I.G.

1988-05-01

79

ZnO nanowire array-templated LbL self-assembled polyelectrolyte nanotube arrays and application for charged drug delivery.  

PubMed

Vertically oriented and robust polyelectrolyte nanotube arrays with high density, large area and high uniformity were successfully grown on substrates by a ZnO nanowire array-templated layer-by-layer (LbL) self-assembly approach for the first time, and were further used to deliver charged drugs, showing that they not only possess pH-responsive loading property, but also significantly enhance the loading capacity and sustained release time. This work could be extended to fabricate polyelectrolyte nanotube arrays with different polyelectrolyte combinations, including weak polyelectrolyte/weak polyelectrolyte, weak polyelectrolyte/strong polyelectrolyte and strong polyelectrolyte/strong polyelectrolyte. With the great versatility to use various substrates and building blocks, the polyelectrolyte nanotube arrays may have great potential for broad applications such as biosensor arrays, bioreactor arrays and optoelectronics. PMID:23299408

Yuan, Weiyong; Lu, Zhisong; Liu, Jinping; Wang, Huili; Li, Chang Ming

2013-02-01

80

ZnO nanowire array-templated LbL self-assembled polyelectrolyte nanotube arrays and application for charged drug delivery  

NASA Astrophysics Data System (ADS)

Vertically oriented and robust polyelectrolyte nanotube arrays with high density, large area and high uniformity were successfully grown on substrates by a ZnO nanowire array-templated layer-by-layer (LbL) self-assembly approach for the first time, and were further used to deliver charged drugs, showing that they not only possess pH-responsive loading property, but also significantly enhance the loading capacity and sustained release time. This work could be extended to fabricate polyelectrolyte nanotube arrays with different polyelectrolyte combinations, including weak polyelectrolyte/weak polyelectrolyte, weak polyelectrolyte/strong polyelectrolyte and strong polyelectrolyte/strong polyelectrolyte. With the great versatility to use various substrates and building blocks, the polyelectrolyte nanotube arrays may have great potential for broad applications such as biosensor arrays, bioreactor arrays and optoelectronics.

Yuan, Weiyong; Lu, Zhisong; Liu, Jinping; Wang, Huili; Li, Chang Ming

2013-02-01

81

WLS R&D for the detection of noble gas scintillation at LBL: seeing the light from neutrinos, to dark matter, to double beta decay  

NASA Astrophysics Data System (ADS)

Radiation detectors with noble gasses as the active medium are becoming increasingly common in experimental programs searching for physics beyond the standard model. Nearly all of these experiments rely to some degree on collecting scintillation light from noble gasses. The VUV wavelengths associated with noble gas scintillation mean that most of these experiments use a fluorescent material to shift the direct scintillation light into the visible or near UV band. We present an overview of the R&D program at LBL related to noble gas detectors for neutrino physics, double beta decay, and dark matter. This program ranges from precise measurements of the fluorescence behavior of wavelength shifting films, to the prototyping of large are VUV sensitive light guides for multi-kiloton detectors.

Gehman, V. M.

2013-09-01

82

Tuning nanostructure of graphene oxide/polyelectrolyte LbL assemblies by controlling pH of GO suspension to fabricate transparent and super gas barrier films  

NASA Astrophysics Data System (ADS)

A technique of layer-by-layer (LbL) self-assembly was used to prepare transparent multilayered gas barrier films consisting of graphene oxide (GO)/branched poly(ethylenimine) (BPEI) on a poly(ethylene terephthalate) substrate. The effect of the GO suspension pH on the nanostructure and oxygen barrier properties of the GO/BPEI film was investigated. The oxygen barrier properties of the assemblies were shown to be highly dependent on the pH. It was demonstrated that the film assemblies prepared using a GO suspension with a pH of 3.5 exhibited very dense and ordered structures and delivered very low oxygen transmission rates (the lowest was <0.05 cm3 m-2 day-1). The assemblies were characterized with ultraviolet-visible spectroscopy and ellipsometry to identify the film growth mechanism, and the result indicated a linear growth behavior. To analyze the nanostructure of the films, atomic force microscopy, transmission electronic microscopy, and grazing incidence wide-angle X-ray diffraction were used.A technique of layer-by-layer (LbL) self-assembly was used to prepare transparent multilayered gas barrier films consisting of graphene oxide (GO)/branched poly(ethylenimine) (BPEI) on a poly(ethylene terephthalate) substrate. The effect of the GO suspension pH on the nanostructure and oxygen barrier properties of the GO/BPEI film was investigated. The oxygen barrier properties of the assemblies were shown to be highly dependent on the pH. It was demonstrated that the film assemblies prepared using a GO suspension with a pH of 3.5 exhibited very dense and ordered structures and delivered very low oxygen transmission rates (the lowest was <0.05 cm3 m-2 day-1). The assemblies were characterized with ultraviolet-visible spectroscopy and ellipsometry to identify the film growth mechanism, and the result indicated a linear growth behavior. To analyze the nanostructure of the films, atomic force microscopy, transmission electronic microscopy, and grazing incidence wide-angle X-ray diffraction were used. Electronic supplementary information (ESI) available: See DOI: 10.1039/c3nr02845c

Chen, Jung-Tsai; Fu, Ywu-Jang; An, Quan-Fu; Lo, Shen-Chuan; Huang, Shu-Hsien; Hung, Wei-Song; Hu, Chien-Chieh; Lee, Kueir-Rarn; Lai, Juin-Yih

2013-09-01

83

Tuning nanostructure of graphene oxide/polyelectrolyte LbL assemblies by controlling pH of GO suspension to fabricate transparent and super gas barrier films.  

PubMed

A technique of layer-by-layer (LbL) self-assembly was used to prepare transparent multilayered gas barrier films consisting of graphene oxide (GO)/branched poly(ethylenimine) (BPEI) on a poly(ethylene terephthalate) substrate. The effect of the GO suspension pH on the nanostructure and oxygen barrier properties of the GO/BPEI film was investigated. The oxygen barrier properties of the assemblies were shown to be highly dependent on the pH. It was demonstrated that the film assemblies prepared using a GO suspension with a pH of 3.5 exhibited very dense and ordered structures and delivered very low oxygen transmission rates (the lowest was <0.05 cm(3) m(-2) day(-1)). The assemblies were characterized with ultraviolet-visible spectroscopy and ellipsometry to identify the film growth mechanism, and the result indicated a linear growth behavior. To analyze the nanostructure of the films, atomic force microscopy, transmission electronic microscopy, and grazing incidence wide-angle X-ray diffraction were used. PMID:23900571

Chen, Jung-Tsai; Fu, Ywu-Jang; An, Quan-Fu; Lo, Shen-Chuan; Huang, Shu-Hsien; Hung, Wei-Song; Hu, Chien-Chieh; Lee, Kueir-Rarn; Lai, Juin-Yih

2013-10-01

84

An improved layer-by-layer self-assembly technique to generate biointerfaces for platelet adhesion studies: Dynamic LbL  

NASA Astrophysics Data System (ADS)

Layer-by-layer self-assembly (LbL) is a technique that generates engineered nano-scale films, coatings, and particles. These nanoscale films have recently been used in multiple biomedical applications. Concurrently, microfabrication methods and advances in microfluidics are being developed and combined to create "Lab-on-a-Chip" technologies. The potential to perform complex biological assays in vitro as a first-line screening technique before moving on to animal models has made the concept of lab on a chip a valuable research tool. Prior studies in the Biofluids Laboratory at Louisiana Tech have used layer-by-layer and in vitro biological assays to study thrombogenesis in a controlled, repeatable, engineered environment. The reliability of these previously established techniques was unsatisfactory for more complex cases such as chemical and shear stress interactions. The work presented in this dissertation was performed to test the principal assumptions behind the established laboratory methodologies, suggest improvements where needed, and test the impact of these improvements on accuracy and repeatability. The assumptions to be tested were: (1) The fluorescence microscopy (FM) images of acridine orange-tagged platelets accurately provide a measure of percent area of surface covered by platelets; (2) fibrinogen coatings can be accurately controlled, interact with platelets, and do not interfere with the ability to quantify platelet adhesion; and (3) the dependence of platelet adhesion on chemical agents, as measured with the modified methods, generally agrees with results obtained from our previous methods and with known responses of platelets that have been documented in the literature. The distribution of fibrinogen on the final LbL surface generated with the standard, static process (s-LbL) was imaged by tagging the fibrinogen with an anti-fibrinogen antibody bound to fluorescein isothiocyanate (FITC). FITC FM images and acridine orange FM images were taken sequentially at selected surface locations to generate a composite overlap of presumed platelet adhesion as a function of fibrinogen distribution. The method was unable to distinguish the surface from the adhered cells. The surface inhomogeneity and porosity retained a large amount of acridine orange stain, even in the absence of platelets, and components in the platelet-rich plasma (PRP) were found to fix acridine orange in a mode that fluoresced in the FITC imaging FM. Both of these problems obfuscated the platelet adhesion FM results when using s-LbL surfaces and acridine orange staining of platelets. A dynamic process (d-LbL) was developed in which a solution of the molecule to be layered was constantly washed over the surface, and was constantly mixed to maintain a more homogeneous distribution of solute relative to the surface during the layering process. The d-LbL surfaces were tested as described above, and found to reduce the size and number of regions of anomalous acridine orange pooling trapped by the surface, providing a greater consistency and reliability in identifying platelets. The improved surface was then used in a series of platelet adhesion experiments under static and dynamic flow conditions, and with and without the chemical additive L-arginine. The complex microcharmel system used in prior studies was replaced with a simpler system involving fewer nuisance variables for these tests. The tests were performed on both collagen and fibrinogen surfaces. Collagen has been used as a thrombogenic surface in multiple studies in the literature, but produces additional variables in thrombogenesis control that are avoided when fibrinogen is used. In these tests, fibrinogen was found to be as thrombogenic as collagen, and platelet coverage of both biointerfaces was reduced by L-arginine in a manner similar to previously reported work. The simpler system differed from the previous microchannel system in important factors: (1) It exposed the platelets to much lower shear stresses; (2) It introduced an oscillatory flow, which introduced a higher de

Lopez, Juan Manuel

85

ECR (Electron Cyclotron Resonance) ion sources for cyclotrons  

SciTech Connect

In the last decade ECR (Electron Cyclotron Resonance) ion sources have evolved from a single large, power consuming, complex prototype into a variety of compact, simple, reliable, efficient, high performance sources of high charge state ions for accelerators and atomic physics. The coupling of ECR sources to cyclotrons has resulted in significant performance gains in energy, intensity, reliability, and variety of ion species. Seven ECR sources are in regular operation with cyclotrons and numerous other projects are under development or in the planning stag. At least four laboratories have ECR sources dedicated for atomic physics research and other atomic physics programs share ECR sources with cyclotrons. An ECR source is now installed on the injector for the CERN SPS synchrotron to accelerate O/sup 8 +/ to relativistic energies. A project is underway at Argonne to couple an ECR source to a superconducting heavy-ion linac. Although tremendous progress has been made, the field of ECR sources is still a relatively young technology and there is still the potential for further advances both in source development and understanding of the plasma physics. The development of ECR sources is reviewed. The important physics mechanisms which come into play in the operation of ECR Sources are discussed, along with various models for charge state distributions (CSD). The design and performance of several ECR sources are compared. The 88-Inch Cyclotron and the LBL ECR is used as an example of cyclotron+ECR operation. The future of ECR sources is considered.

Lyneis, C.M.

1986-10-01

86

Performance of the Advanced Light Source  

SciTech Connect

The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL) is the first of the lower energy (1--2 GeV) third-generation synchrotron radiation facilities to come into operation. Designed with very small electron beam emittances to operate with long insertion devices producing very high brightness beams of synchrotron radiation in the VUV and soft x-ray regions of the spectrum, these facilities are complementary to the higher energy (6--9 GeV) facilities designed for harder x-radiation. The ALS storage ring began operation in October 1993. In this paper, we will review the operational performance of the ALS, including the effects of the 4.5 m long undulators (period 5 cm), and discuss the overall performance of the facility.

Jackson, A.

1994-06-01

87

Advanced Light Source beam position monitor  

SciTech Connect

The Advanced Light Source (ALS) is a synchrotron radiation facility nearing completion at LBL. As a third-generation machine, the ALS is designed to produce intense light from bend magnets, wigglers, and undulators (insertion devices). The facility will include a 50 MeV electron linear accelerator, a 1.5 GeV booster synchrotron, beam transport lines, a 1--2 GeV storage ring, insertion devices, and photon beam lines. Currently, the beam injection systems are being commissioned, and the storage ring is being installed. Electron beam position monitors (BPM) are installed throughout the accelerator and constitute the major part of accelerator beam diagnostics. The design of the BPM instruments is complete, and 50 units have been constructed for use in the injector systems. We are currently fabricating 100 additional instruments for the storage ring. In this paper I discuss engineering fabrication, testing and performance of the beam pickup electrodes and the BPM electronics.

Hinkson, J.

1991-10-28

88

LBL neutralized beam focusing experiment  

SciTech Connect

An intense neutralized Cs/sup +1/ beam has been focused by an electrostatic polarization field induced by a solenoidal magnetic field of 10-25 gauss. This report describes the experiment and compares the results with the predictions of an analytic linearized fluid model and a particle-in-cell simulation which treats the motion of the warm electrons in detail.

Krafft, G.A.; Kim, C.H.; Smith, L.

1985-05-01

89

LBL EBIS test-strand  

SciTech Connect

An EBIS program was initiated at Lawrence Berkeley Laboratory in late 1979. This first stage, construction of an EBIS research and development test-stand is described, along with results of the bare beam experiments.

Feinberg, B.; Brown, I.G.

1981-05-01

90

LBL's Pollution Instrumentation Comparability Program.  

ERIC Educational Resources Information Center

Contained are condensed excerpts from the Lawrence Berkeley Laboratory Survey of Instrumentation for Environmental Monitoring. The survey describes instrumentation used to analyze air and water quality, radiation emissions, and biomedical impacts. (BB)

McLaughlin, R. D.; And Others

1979-01-01

91

Operation of a magnetically filtered multicusp volume source  

SciTech Connect

The results of experimental studies on an optimized version of the Lawrence Berkeley Laboratory (LBL) volume source are presented. Negative ion yields and emittance data were obtained for operation with both H/sup -/ and D/sup -/ beams. At high arc power, H/sup -/ beam currents up to 10 mA with rms normalized emittances of 0.0080 ..pi...cm.mrad were obtained from a 6.3-mm-dia emission aperture. The yields of D/sup -/ beams were approximately half those of H/sup -/ beams, and the normalized emittances were 1.7 times smaller at the same current density. The results of these studies indicate that the present operation is limited by the extraction system rather than the ion source.

Stevens, R.R. Jr.; York, R.L.; Leung, K.N.; Ehlers, K.W.

1986-01-01

92

Measurements of neutral beam species, impurities, spatial divergence, energy dispersion, pressure, and reionization for the TFTR (Tokamak Fusion Test Reactor) US Common Long Pulse Ion Source  

SciTech Connect

Physical characteristics of TFTR neutral beams were measured during the first tests and initial operating experience with production TFTR US Common Long Pulse Ion Sources on beamlines in the TFTR experimental environment under actual user conditions. These measurements were performed with different power supply systems, controls, diagnostics, and operating methods compared to those used at LBL during the development phase. The set of diagnostics included water calorimetry, thermocouples, vacuum ionization gauges, photodiodes, neutron, gamma-ray and charged particle backscatter spectroscopy, and implantation/secondary ion mass spectroscopy. These systems were used to perform complementary measurements of neutral beam species, measurements were performed either in the neutralizer region, where the beam contained both ions and neutrals, or in the region of the output neutral beam. In general, consistent with estimates made during the LBL development phase. They can provide guidance for the optimization of TFTR neutral beam heating operations and the understanding of auxilliary heated TFTR plasmas. 21 refs., 28 figs., 2 tabs.

Kugel, H.W.; Gammel, G.M.; Grisham, L.R.; Kaita, R.; Kamperschroer, J.H.; Langley, R.A.; Magee, C.W.; Medley, S.S.; Murphy, T.J.; Roquemore, A.L.; Williams, M.D.

1988-06-01

93

Engineering for high heat loads on ALS (Advanced Light Source) beamlines  

SciTech Connect

This paper discussed general thermal engineering problems and specific categories of thermal design issues for high photon flux beam lines at the LBL Advanced Light Source: thermal distortion of optical surfaces and elevated temperatures of thermal absorbers receiving synchrotron radiation. A generic design for water-cooled heat absorbers is described for use with ALS photon shutters, beam defining apertures, and heat absorbing masks. Also, results of in- situ measurements of thermal distortion of a water-cooled mirror in a synchrotron radiation beam line are compared with calculated performance estimates. 17 refs., 2 figs.

DiGennaro, R.; Swain, T.

1989-08-01

94

Transverse coupled-bunch feedback in the Advanced Light Source (ALS)  

SciTech Connect

In order to effectively control a large number of transverse coupled-bunch models in the LBL Advanced Light source (ALS) storage ring, a broad-band, bunch-by-bunch feedback system has been designed, and is beginning to undergo testing and commissioning. This paper addresses the major electronic components of the feedback system. In particular, the components described include: broad-band microwave position detection receivers, closed orbit offset signal rejection circuitry, and baseband quadrature processing circuitry. Initial commissioning results are also presented.

Barry, W.; Byrd, J.; Corlett, J.; Lambertson, G.R.; Lo, C.C.

1994-06-01

95

A directly cooled grating substrate for ALS (Advanced Light Source) undulator beam lines  

SciTech Connect

Design analyses using finite element methods are presented for thermal distortion of water-cooled diffraction grating substrates for a potential application at the LBL Advanced Light Source, demonstrating that refinements in cooling channel configuration and heat flux distribution can significantly reduce optical surface distortion with high heat loads. Using an existing grating substrate design, sensitivity of tangential slope errors due to thermal distortion is evaluated for a variety of thermal boundary conditions, including coolant flow rate and heat transfer film coefficients, surface illumination area and heat distribution profile, and location of the convection cooling surfaces adjacent to the heated region. 1 ref., 5 figs., 2 tabs.

DiGennaro, R.; Swain, T.

1989-08-01

96

Optimization of surface plasma sources for efficient production of negative ions with high emission current density  

NASA Astrophysics Data System (ADS)

The main mechanism of negative ion formation in a Surface Plasma Source (SPS) is secondary emission of sputtered and scattered particles accompanied by capture of electrons from the electrodes. In the first, pulsed, versions of the SPS, adding a small amount of cesium increased the emission current density for light ions up to 3.7 A/cm2 with a flat emitter and up to 8 A/cm2 after optimization of geometrical focusing. Since this power density was too high for DC operation, LBL developed a large volume SPS with a hot cathode discharge, a large emitter-emission aperture gap and low emission current density. The LBL type of SPS was used for some accelerators and for heavy negative ion production with emission current density of 10 mA/cm2. Researchers at Budker Institute of Nuclear Physics (BINP) developed a small SPS optimized for long time DC operation. In the BINP source, DC H- current up to 2.5 mA and heavy ion current up to 1 mA have been extracted from a 1 mm diameter aperture using an improved SPS that employs a hollow cathode discharge and spherical focusing of negative ions toward the emission aperture. This paper describes further optimization of this type source for production of negative ion beam with a high emission current density. .

Farrell, J. Paul; Dudnikov, V.; Dudnikova, G.

2001-12-01

97

Combustion Area Sources: Data Sources.  

National Technical Information Service (NTIS)

The report identifies, documents, and evaluates data sources for stationary area source emissions, including solid waste and agricultural burning. Area source emissions of particulate matter, sulfur dioxide, oxides of nitrogen, reactive volatile organic c...

D. Bowman S. Lowe J. Purple R. Randolph D. Winkler

1992-01-01

98

Design considerations for a negative ion source for dc operation of high-power, multi-megaelectron-volt neutral beams  

SciTech Connect

A dc negative hydrogen and/or deuterium ion source is needed to produce high-power, high-energy neutral beams for alpha diagnostics and current drive applications in fusion devices. The favorable beam particle energy for such applications extends to 1.5 MeV/amu. Continuous-wave (cw) radiofrequency quadrupole (RFQ) accelerators have been proposed to accelerate negative ions efficiently to this energy range. In this paper, the desired beam properties for ion beams injected into cw RFQ accelerators are summarized. A number of candidate ion sources being developed at Culham, JAERI, LBL, and ORNL may prove useful for these applications. The properties of the Volume Ionization with Transverse Extraction (VITEX) ion sources being developed at ORNL are presented. Scaling such a dc ion source to produce ampere beams is discussed. 53 refs., 4 figs., 2 tabs.

Tsai, C.C.; Stirling, W.L.; Akerman, M.A.; Becraft, W.R.; Dagenhart, W.K.; Haselton, H.H.; Ryan, P.M.; Schechter, D.E.; Whealton, J.H.

1987-01-01

99

Neutron dose equivalents at the Advanced Light Source: Calculation using the MORSE code vs estimated values  

SciTech Connect

The Advanced Light Source (ALS) complex at the Lawrence Berkeley Laboratory (LBL) is surrounded by a mezzanine and auxiliary buildings. An important radiological problem is the neutron dose equivalent in nearby occupied areas and at the LBL site boundary. Both the direct and air-scattered (skyshine) components of the neutron dose equivalents are evaluated using the neutron transport code MORSE. The shielding was designed using an empirical method based on data scaled from a 1977 SLAC experiment and on a compilation of experimental and theoretical material relevant to shielding of electron accelerators. From the MORSE calculation, the total occupational dose equivalent rate in the center of the ALS mezzanine was found to be less than 1 mSv (100 mrem) per shift year (2000-hr), and the total environmental dose equivalent rate at the ALS boundary, 125 m from the storage-ring center, was found to be about 302 {mu}Sv (30 mrem) per year. A comparison of the dose equivalents shows that the calculated MORSE-code values agree well with those estimated by the empirical method. That is, dose equivalents obtained by the empirical methods are of the same order of magnitude as the corresponding MORSE values. 7 refs., 7 figs., 2 tabs.

Sun, Rai-Ko S.

1991-02-01

100

Ion source  

DOEpatents

A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species.

Leung, Ka-Ngo (Hercules, CA); Ehlers, Kenneth W. (Alamo, CA)

1984-01-01

101

Energy Sources  

NSDL National Science Digital Library

Although California uses more renewable resources than many other states, much of the state's electricity still comes from nonrenewable sources. Find out how using renewable energy sources to create electricity helps reduce fossil fuel consumption and how it has the potential to have the largest impact on climate change.

Kqed

2012-03-27

102

Light Source  

Microsoft Academic Search

Bioelectromagnetics\\/resonance effect Using a Synchroton Light source to probe brain mechanism This paper suggests that photons or instantons from a Synchrotron light source, activates brain cells, which because of membrane polaribility can receive light. It explains how synchrotron radiation can pentrate and activate cells,and thus serve as an excellent probe of brain mechanisms. Wavelengths the broad range of synchrotron light

Jane Krakower

2000-01-01

103

Muon Sources.  

National Technical Information Service (NTIS)

A full high energy muon collider may take considerable time to realize. However, intermediate steps in its direction are possible and could help facilitate the process. Employing an intense muon source to carry out forefront low energy research, such as t...

Z. Parsa

2001-01-01

104

Food Sources  

Cancer.gov

Understanding what foods contribute to energy, nutrient, and food group intake enhances our ability to monitor diets relative to recommendations and gives context for dietary guidance. Examining the top sources of dietary constituents that should be reduced is especially helpful for identifying targets for changes in the marketplace and food environment.

105

Superluminal sources.  

PubMed

Predictions for the apparent velocity statistics under simple beaming models are presented and compared to the observations. The potential applications for tests of unification models and for cosmology (source counts, measurements of the Hubble constant H0 and the deceleration parameter q0) are discussed. First results from a large homogeneous survey are presented. The data do not show compelling evidence for the existence of intrinsically different populations of galaxies, BL Lacertae objects, or quasars. Apparent velocities betaapp in the range 1-5 h-1, where h = H0/100 km.s-1.Mpc-1 [1 megaparsec (Mpc) = 3.09 x 10(22) m], occur with roughly equal frequency; higher values, up to betaapp = 10 h-1, are rather more scarce than appeared to be the case from earlier work, which evidently concentrated on sources that are not representative of the general population. The betaapp distribution suggests that there might be a skewed distribution of Lorentz factors over the sample, with a peak at gammab approximately 2 h-1 and a tail up to at least gammab approximately 10 h-1. There appears to be a clearly rising upper envelope to the betaapp distribution when plotted as a function of observed 5-GHz luminosity; a combination of source counts and the apparent velocity statistics in a larger sample could provide much insight into the properties of radio jet sources. PMID:11607604

Vermeulen, R C

1995-12-01

106

Superluminal sources.  

PubMed Central

Predictions for the apparent velocity statistics under simple beaming models are presented and compared to the observations. The potential applications for tests of unification models and for cosmology (source counts, measurements of the Hubble constant H0 and the deceleration parameter q0) are discussed. First results from a large homogeneous survey are presented. The data do not show compelling evidence for the existence of intrinsically different populations of galaxies, BL Lacertae objects, or quasars. Apparent velocities betaapp in the range 1-5 h-1, where h = H0/100 km.s-1.Mpc-1 [1 megaparsec (Mpc) = 3.09 x 10(22) m], occur with roughly equal frequency; higher values, up to betaapp = 10 h-1, are rather more scarce than appeared to be the case from earlier work, which evidently concentrated on sources that are not representative of the general population. The betaapp distribution suggests that there might be a skewed distribution of Lorentz factors over the sample, with a peak at gammab approximately 2 h-1 and a tail up to at least gammab approximately 10 h-1. There appears to be a clearly rising upper envelope to the betaapp distribution when plotted as a function of observed 5-GHz luminosity; a combination of source counts and the apparent velocity statistics in a larger sample could provide much insight into the properties of radio jet sources.

Vermeulen, R C

1995-01-01

107

Energy Sources  

NSDL National Science Digital Library

This interactive website for students discusses both renewable and nonrenewable resources. It also discusses electricity and hyrdogen energy in depth. Furthermore, it provides a link to recent energy source statistics which can help students to identify the United States dependency on imports such as petroleum and natural gas.

2009-01-01

108

An RF driven H{sup {minus}} source and a low energy beam injection system for RFQ operation  

SciTech Connect

An RF driven H{sup {minus}} source has been developed at LBL for use in the Superconducting Super Collider (SSC). To date, an H{sup {minus}} current of {approx}40 mA can be obtained from a 5.6-cm-diam aperture with the source operated at a pressure of about 12 m Torr and 50 kW of RF power. In order to match the accelerated H{sup {minus}} beam into the SSC RFQ, a low-energy H{sup {minus}} injection system has been designed. This injector produces an outgoing H{sup {minus}} beam free of electron contamination, with small radius, large convergent angle and small projectional emittance.

Leung, K.N.; Bachman, D.A.; Chan, C.F.; McDonald, D.S.

1992-12-31

109

MUON SOURCES.  

SciTech Connect

A full high energy muon collider may take considerable time to realize. However, intermediate steps in its direction are possible and could help facilitate the process. Employing an intense muon source to carry out forefront low energy research, such as the search for muon-number non-conservation, represents one interesting possibility. For example, the MECO proposal at BNL aims for 2 x 10{sup {minus}17} sensitivity in their search for coherent muon-electron conversion in the field of a nucleus. To reach that goal requires the production, capture and stopping of muons at an unprecedented 10{sup 11} {mu}/sec. If successful, such an effort would significantly advance the state of muon technology. More ambitious ideas for utilizing high intensity muon sources are also being explored. Building a muon storage ring for the purpose of providing intense high energy neutrino beams is particularly exciting.We present an overview of muon sources and example of a muon storage ring based Neutrino Factory at BNL with various detector location possibilities.

PARSA,Z.

2001-02-16

110

Radiation source  

DOEpatents

A device and method for relativistic electron beam heating of a high-density plasma in a small localized region. A relativistic electron beam generator or accelerator produces a high-voltage electron beam which propagates along a vacuum drift tube and is modulated to initiate electron bunching within the beam. The beam is then directed through a low-density gas chamber which provides isolation between the vacuum modulator and the relativistic electron beam target. The relativistic beam is then applied to a high-density target plasma which typically comprises DT, DD, or similar thermonuclear gas at a density of 10.sup.17 to 10.sup.20 electrons per cubic centimeter. The target gas is ionized prior to application of the relativistic electron beam by means of a laser or other preionization source to form a plasma. Utilizing a relativistic electron beam with an individual particle energy exceeding 3 MeV, classical scattering by relativistic electrons passing through isolation foils is negligible. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy into a small localized region of the high-density plasma target.

Thode, Lester E. (Los Alamos, NM)

1981-01-01

111

Source Water Protection  

MedlinePLUS

... Drinking Water Source Water Source Water Protection Source Water Protection The drinking water we receive from our ... communities, resource managers and the public. My Source Water Basic Information Frequent Questions Source Water Pocket Guide ( ...

112

Primary and Secondary Sources  

NSDL National Science Digital Library

Use these links to learn more about primary and secondary sources. 1. Explore the links below to learn about primary and secondary sources. When you have finished, you should be able to: Tell the difference between primary and secondary sources. Give at least three examples of primary sources and three examples of secondary sources. Explain why primary sources are important in research. Examples of Primary Sources Examples of Primary and Secondary Sources on the Same Topic Genres/Formats of Primary Sources 2. ...

Bates, Albion M.

2010-01-23

113

Links Between Z Sources and Atoll Sources  

NASA Astrophysics Data System (ADS)

It is known that the Z and atoll sources are two typical types of neutron-star sources in low mass X-ray binaries (LMXBs), which present very different Q-? relations of lower kHz QPOs. We propose that the Z and atoll sources are two different phases in the evolutionary track of neutron star in LMXBs, instead of two types of distinct sources.

Wang, Joan Jing; Chang, Hsiang-Kuang

2013-02-01

114

Monitoring the source monitoring.  

PubMed

The hypothesis that the retrieval of correct source memory cues, those leading to a correct source attribution, increases confidence, whereas the retrieval of incorrect source memory cues, those leading to a source misattribution, decreases confidence was tested. Four predictions were derived from this hypothesis: (1) confidence should be higher for correct than incorrect source attribution except; (2) when no source cues are retrieved; (3) only the source misattributions inferred from the retrieval of incorrect source cues will be rated with low confidence; and (4) the number of source cues retrieved, either correct or incorrect, will affect the confidence in the source attributions. To test these predictions, participants read two narratives from two witnesses to a bank robbery, a customer and a teller. Then, participants completed a source monitoring test with four alternatives, customer, teller, both, or neither, and rated their confidence in their source attribution. Results supported the first three predictions, but they also suggested that the number of correct source monitoring cues retrieved did not play a role in the monitoring of the accuracy of the source attributions. Attributions made from the recovery of incorrect source cues could be tagged as dubious or uncertain, thus leading to lowered confidence irrespective of the number of incorrect source cues or whether another correct source cue was also recovered. This research has potential applications for eyewitness memory because it shows that confidence can be an indicator of the accuracy of a source attribution. PMID:23553316

Luna, Karlos; Martín-Luengo, Beatriz

2013-11-01

115

2003 Competitive Sourcing Report  

NSF Publications Database

2003 Competitive Sourcing Report Competitions to Date and Planned Competitions During FY 2003, NSF ... to NSF?s organizational structure and staff composition. NSF considers competitive sourcing an ...

116

2004 Competitive Sourcing Report  

NSF Publications Database

2004 Competitive Sourcing Report Competitions to Date and Planned Competitions During FY 2004, NSF ... announced during FY 2005. Alignment of Competitive Sourcing and Strategic Workforce Planning The ...

117

The marine seismic source  

SciTech Connect

The contents of this book are: Underlying physics and concepts; Source arrays and directivity; Interaction and wavefield determination; Practical aspects of wavefield stability; Source signature deconvolution; and Index.

Gregg, P.; Hatton, L.

1986-01-01

118

Querying Heterogeneous Information Sources Using Source Descriptions  

Microsoft Academic Search

We witness a rapid increase in the number of structured information sources that are available online, especially on the World-Wide Web. These sources store interrelated data on topics such as product information, stock market information,entertainment, etc. We would like to use the data stored in these databases to answer complex queries that go beyond keyword searches. We describe the Information

Alon Y. Levy; Anand Rajaraman; Joann J. Ordille

1996-01-01

119

Source apportionment with site specific source profiles  

SciTech Connect

A receptor modeling study was performed to identify and apportion the sources of PM{sub 10} mass in Granite City, Illinois, an area of histroic TSP nonattainment. Samples of the ambient aerosol were collected using a dichotomous sampler. Each sample was analyzed by x-ray fluorescence and instrumental neutron activation analysis. To begin the study, a factor analysis was performed. Two different chemical mass balance (CMB) analyses were then made. The first CMB analysis used only source profiles available from the literature while the second included twelve source profiles developed from dust samples collected in Granite City. Both CMB analyses used 20 of the 33 analyzed elements since many of the source profiles in the literature did not include the other thirteen elements. The results from both sets of CMB analyses were grouped by the predominate wind direction at the site during the time each sample was taken to identify the direction of each source relative to the sampler. It was found that regional sources were the primary contributors to the fine fraction while the coarse fraction was composed of material from local industries. These sources were generally the ones identified during the Regional Air Pollution Study previously conducted in the area. However, the emission profiles from these sources were observed to have changed between the studies. it was also found that the use of the locally generated profiles greatly improved the results of the CMB analysis.

Glover, D.M.; Hopke, P.K.; Landsberger, S. (Univ. of Illinois, Urbana (United States)); Vermette, S.J. (Illinois State Water Survey, Champaign (United States)); D'Auben, D.R. (Illinois Environmental Protection Agency, Springfield (United States))

1991-05-01

120

THE CHANDRA SOURCE CATALOG  

SciTech Connect

The Chandra Source Catalog (CSC) is a general purpose virtual X-ray astrophysics facility that provides access to a carefully selected set of generally useful quantities for individual X-ray sources, and is designed to satisfy the needs of a broad-based group of scientists, including those who may be less familiar with astronomical data analysis in the X-ray regime. The first release of the CSC includes information about 94,676 distinct X-ray sources detected in a subset of public Advanced CCD Imaging Spectrometer imaging observations from roughly the first eight years of the Chandra mission. This release of the catalog includes point and compact sources with observed spatial extents {approx}<30''. The catalog (1) provides access to the best estimates of the X-ray source properties for detected sources, with good scientific fidelity, and directly supports scientific analysis using the individual source data; (2) facilitates analysis of a wide range of statistical properties for classes of X-ray sources; and (3) provides efficient access to calibrated observational data and ancillary data products for individual X-ray sources, so that users can perform detailed further analysis using existing tools. The catalog includes real X-ray sources detected with flux estimates that are at least 3 times their estimated 1{sigma} uncertainties in at least one energy band, while maintaining the number of spurious sources at a level of {approx}<1 false source per field for a 100 ks observation. For each detected source, the CSC provides commonly tabulated quantities, including source position, extent, multi-band fluxes, hardness ratios, and variability statistics, derived from the observations in which the source is detected. In addition to these traditional catalog elements, for each X-ray source the CSC includes an extensive set of file-based data products that can be manipulated interactively, including source images, event lists, light curves, and spectra from each observation in which a source is detected.

Evans, Ian N.; Primini, Francis A.; Glotfelty, Kenny J.; Anderson, Craig S.; Bonaventura, Nina R.; Chen, Judy C.; Doe, Stephen M.; Evans, Janet D.; Fabbiano, Giuseppina; Galle, Elizabeth C.; Gibbs, Danny G.; Grier, John D.; Hain, Roger M.; Harbo, Peter N.; He Xiangqun; Karovska, Margarita; Kashyap, Vinay L. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Davis, John E.; Houck, John C. [MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Hall, Diane M., E-mail: ievans@cfa.harvard.ed [Northrop Grumman, 60 Garden Street, Cambridge, MA 02138 (United States)

2010-07-15

121

Program improvement by source to source transformation  

Microsoft Academic Search

We treat a program as an object of manipulation, determine items of program constancy, and simplify the program based on the constancy. Some motivation for program manipulation is presented, along with two examples of “higher level optimization” written in an Algol-like language. A collection of program transformations and a model of the compilation process in terms of source-to-source transformations are

David B. Loveman

1976-01-01

122

PENNING ION SOURCE  

Microsoft Academic Search

The design, construction, and operating characteristics of a Penning ; ion source which is used in the CERN synchrocyclotron are described. Other ; possible applications of a Penning ion source are discussed. (j.S.R.);

1958-01-01

123

Sealed Radioactive Sources  

MedlinePLUS

... replacement of sealed sources in devices with non-nuclear alternatives to reduce the number of sources in ... page Who else is working on this problem? Nuclear Regulatory Commission (NRC) NRC is increasing regulatory control ...

124

iSource  

NSDL National Science Digital Library

iSource, the Web presence of the magazine iSource, is dedicated to supply chain solutions. The site features short daily news stories written by the iSource.com editorial staff along with several in-depth articles. Also included are video archived presentations from the iSource 100 Summit. While the Website serves mainly as a teaser for the print version of the magazine, it does cover important supply chain information.

125

Familiarity in Source Memory  

PubMed Central

Familiarity and recollection are thought to be separate processes underlying recognition memory. Event-related potentials (ERPs) dissociate these processes, with an early (approximately 300–500 ms) frontal effect relating to familiarity (the FN400) and a later (500–800 ms) parietal old/new effect relating to recollection. It has been debated whether source information for a studied item (i.e., contextual associations from when the item was previously encountered) is only accessible through recollection, or whether familiarity can contribute to successful source recognition. It has been shown that familiarity can assist in perceptual source monitoring when the source attribute is an intrinsic property of the item (e.g., an object’s surface color), but few studies have examined its contribution to recognizing extrinsic source associations. Extrinsic source associations were examined in three experiments involving memory judgments for pictures of common objects. In Experiment 1, source information was spatial and results suggested that familiarity contributed to accurate source recognition: the FN400 ERP component showed a source accuracy effect, and source accuracy was above chance for items judged to only feel familiar. Source information in Experiment 2 was an extrinsic color association; source accuracy was at chance for familiar items and the FN400 did not differ between correct and incorrect source judgments. Experiment 3 replicated the results using a within-subjects manipulation of spatial vs. color source. Overall, the results suggest that familiarity’s contribution to extrinsic source monitoring depends on the type of source information being remembered.

Mollison, Matthew V.; Curran, Tim

2012-01-01

126

Stable Pulsed Light Source.  

National Technical Information Service (NTIS)

The patent describes a pulsed light source for use as a standard source of light for the calibration of photomultiplier tubes and the like. The source uses an inexpensive light-emitting diode and produces pulses whose height and length may be adjusted. Te...

J. H. Thorngate P. T. Perdue

1974-01-01

127

Neutron source progress report  

Microsoft Academic Search

This document is a de-classified June 1948 progress report on neutron source development at Monsanto Chemical`s Mound facility. Specific sources reviewed are: (1) Postum-beryllium, (2) Postum-Boron and Postum-Fluoborate, and (3) Postum-Lithium and Postum-Sodium. Preparation of each source is discussed, and some of their physical properties are given.

L. Bentz; J. Birden; R. Hertz

1948-01-01

128

Available Data Sources  

ERIC Educational Resources Information Center

Highlights new sources of socio-economic data from both governmental and non-governmental sources that can be used for planning and programming at the national, state, and local levels. Sources refer to the aged, health, persons of Spanish origin, minority doctorates, employment of minorities and women, and tax relief. (Author/AM)

Urban League Review, 1975

1975-01-01

129

Stationary quantum source coding  

NASA Astrophysics Data System (ADS)

In this article the quantum version of the source coding theorem is obtained for a completely ergodic source. This result extends Schumacher's quantum noiseless coding theorem for memoryless sources. The control of the memory effects requires some earlier results of Hiai and Petz on high probability subspaces. Our result is equivalently considered as a compression theorem for noiseless stationary channels.

Petz, Dénes; Mosonyi, Milán

2001-10-01

130

Extragalactic Radio Sources  

ERIC Educational Resources Information Center

Discusses new problems arising from the growing observational data through radio telescope arrays, involving the origin of radio sources, apparent superluminal velocities, conversion of radio sources to relativistic particles, and the nature of compact opaque and extended transparent sources. New physics may be needed to answer these cosmological…

Kellerman, Kenneth I.

1973-01-01

131

Investigating Primary Source Literacy  

ERIC Educational Resources Information Center

Primary source research requires students to acquire specialized research skills. This paper presents results from a user study testing the effectiveness of a Web guide designed to convey the concepts behind "primary source literacy". The study also evaluated students' strengths and weaknesses when conducting primary source research. (Contains 3…

Archer, Joanne; Hanlon, Ann M.; Levine, Jennie A.

2009-01-01

132

Single hydrophone source localization  

Microsoft Academic Search

The method presented in this paper assumes that the received signal is a linear combination of delayed and attenuated uncorrelated replicas of the source emitted waveform. The set of delays and attenuations, together with the channel environmental conditions, provide sufficient information for determining the source location. If the transmission channel is assumed known, the source location can be estimated by

Sérgio M. Jesus; Michael B. Porter; Yann Stéphan; Xavier Démoulin; Orlando C. Rodríguez; Emanuel M. M. Ferreira Coelho

2000-01-01

133

ENHANCED SOURCE CONTROL: CAIMITO  

Microsoft Academic Search

Source control systems enable collaboration between software developers by providing ways to manage projects and track source code revisions. Early source control systems were not effective at parallelizing software development. Concurrent Version System (CVS) was developed to address this major shortcoming and also to allow for remote software development, but it introduced the problem of merging conflicting changes from multiple

Danushka Abeysuriya

134

Comparison of H sup minus and D sup minus production in a magnetically filtered multicusp source  

SciTech Connect

A JAERI (Japan Atomic Energy Research Institute)negative ion source was tested at LBL (Lawrence Berkeley Laboratory) as part of the U.S.--Japan Fusion Cooperation Program. By varying the strength of the magnetic filter from 450 to 930 G cm, we compared production, transport, and extraction of the negative ions. The maximum current densities, which were obtained at the corresponding optimum filter strength for each gas species, were 10.4 mA/cm{sup 2} for H{sup {minus}} and 8.4 mA/cm{sup 2} for D{sup {minus}} at arc discharges of 40 kW. The ratio of the ion current densities ({ital J}{sub D{sup {minus}}}/{ital J}{sub H{sup {minus}}}) is about 0.8, which is higher than 1/(2){sup 1/2} . The electron to negative ion ratio was 13 for hydrogen and 38 for deuterium at the corresponding optimum filter strength. The higher ratio in deuterium is probably due to higher space potential of deuterium plasma by a few volts.

Inoue, T.; Ackerman, G.D.; Cooper, W.S.; Hanada, M.; Kwan, J.W.; Ohara, Y.; Okumura, Y.; Seki, M. (Japan Atomic Energy Research Institute, Naka-machi, Naka-gun, Ibaraki-ken 311-01, Japan (JP))

1990-01-01

135

Comparison of H sup minus and D sup minus production in a magnetically filtered multicusp source  

SciTech Connect

A JAERI negative ion source was tested at LBL as part of the US-Japan Fusion Cooperation Program. By varying the strength of magnetic filter from 450 to 930 Gauss-cm, we compared production, transport, and extraction of the negative ions. The maximum current densities, which obtained at the corresponding optimum filter strength for each gas species, were 10.4 mA/cm{sup 2} for H{sup {minus}} and 8.4 mA/cm{sup 2} for D{sup {minus}} at arc discharges of 40 kW. The ratio of the ion current densities (J{sub D}{minus}/J{sub H}{minus}) is about 0.8, which is higher than 1/{radical}2. The electron to negative ion ration was 13 for hydrogen and 38 for deuterium at the corresponding optimum filter strength. The higher ratio in deuterium is probably due to higher space potential of deuterium plasma by a few volts. 9 refs., 7 figs.

Inoue, T.; Ackerman, G.D.; Cooper, W.S.; Hanada, M.; Kwan, J.W.; Ohara, Y.; Okumura, Y.; Seki, M. (Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan))

1989-04-01

136

Brain protein deciphered at Advanced Light Source  

ScienceCinema

This computer-generated model of a rat glutamate receptor is the first complete portrait of this important link in the nervous system. At the top of the Y-shaped protein, a pair of molecules splay outward like diverging prongs. The bottom section, which is embedded in a neuronal membrane, houses the ion channel. The resolution of this image is 3.6 angstroms per pixel, or just under four ten-billionths of a meter per image unit. http://newscenter.lbl.gov/feature-stories/2010/01/21/glutamate-receptor/

137

Brain protein deciphered at Advanced Light Source  

SciTech Connect

This computer-generated model of a rat glutamate receptor is the first complete portrait of this important link in the nervous system. At the top of the Y-shaped protein, a pair of molecules splay outward like diverging prongs. The bottom section, which is embedded in a neuronal membrane, houses the ion channel. The resolution of this image is 3.6 angstroms per pixel, or just under four ten-billionths of a meter per image unit. http://newscenter.lbl.gov/feature-stories/2010/01/21/glutamate-receptor/

None

2010-01-01

138

Electric power source device  

SciTech Connect

An electric power source device is described for a motor vehicle having an ignition switch having an off position, comprising: a casing; a battery with electrolyte; a source of electricity; the battery and the source of electricity being included by the casing; means for conditioning the electrolyte of the battery in such a manner as to prevent a drop in capacity of the battery which might otherwise be caused by ambient temperature where the battery is disposed; connecting means for connecting the source of electricity to the battery to charge the battery, the connecting means including a change-over switch means having a charging mode position for connecting the source of electricity to the battery to charge the battery; and controlling means for controlling the change-over switch means in such a manner for disconnecting the source of electricity from the battery when the ignition switch is turned on.

Nakamura, M.; Takagi, Y.; Urakawa, H.

1987-03-17

139

Self-assembled films containing crude extract of avocado as a source of tyrosinase for monophenol detection.  

PubMed

This paper reports on the use of the crude extract of avocado (CEA) fruit (Persea americana) as a source of tyrosinase enzyme. CEA was immobilized via layer by layer (LbL) technique onto indium tin oxide (ITO) substrates and applied in the detection of monophenol using a potentiometric biosensor. Poly(propylene imine) dendrimer of generation 3 (PPI-G3) was used as a counter ion in the layer by layer process due to its highly porous structure and functional groups suitable for enzyme linkage. After the immobilization of the crude CEA as multilayered films, standard samples of monophenol were detected in the 0.25-4.00 mM linear range with approximately 28 mV mM(-1) of sensitivity. This sensitivity is 14 times higher than the values found in the literature for a similar system. The results show that it is possible to obtain efficient and low-cost biosensors for monophenol detection using potentiometric transducers and alternative sources of enzymes without purification. PMID:23910293

Vieira, Nirton C S; Ferreira, Reginaldo A; da Cruz Rodrigues, Valquiria; Guimarães, Francisco E G; de Queiroz, Alvaro A A

2013-10-01

140

Source and replica calculations  

SciTech Connect

The starting point of the Hiroshima-Nagasaki Dose Reevaluation Program is the energy and directional distributions of the prompt neutron and gamma-ray radiation emitted from the exploding bombs. A brief introduction to the neutron source calculations is presented. The development of our current understanding of the source problem is outlined. It is recommended that adjoint calculations be used to modify source spectra to resolve the neutron discrepancy problem.

Whalen, P.P.

1994-02-01

141

Rf power sources  

SciTech Connect

This paper covers RF power sources for accelerator applications. The approach has been with particular customers in mind. These customers are high energy physicists who use accelerators as experimental tools in the study of the nucleus of the atom, and synchrotron light sources derived from electron or positron storage rings. This paper is confined to electron-positron linear accelerators since the RF sources have always defined what is possible to achieve with these accelerators. 11 refs., 13 figs.

Allen, M.A.

1988-05-01

142

Pulsed spallation neutron sources  

SciTech Connect

This paper reviews the early history of pulsed spallation neutron source development ar Argonne and provides an overview of existing sources world wide. A number of proposals for machines more powerful than currently exist are under development, which are briefly described. The author reviews the status of the Intense Pulsed Neutron Source, its instrumentation, and its user program, and provide a few examples of applications in fundamental condensed matter physics, materials science and technology.

Carpenter, J.M. [Argonne National Lab., IL (United States). Intense Pulsed Neutron Source Div.

1996-05-01

143

Open Source Physics  

NSDL National Science Digital Library

The Open Source Physics Project creates and distributes curricular material for physics education and computational physics. Compiled programs, curricular materials, a modeling environment, Java code libraries, and data analysis tools are included. The learning resources include interactive explorations, conceptual and analytic exercises, and tutorials. Open Source Physics projects include curriculum for computational physics and statistical physics, video analysis software, and upper division physics courses. Open Source Physics is supported by the National Science Foundation.

2006-03-03

144

Dynamic radioactive particle source  

DOEpatents

A method and apparatus for providing a timed, synchronized dynamic alpha or beta particle source for testing the response of continuous air monitors (CAMs) for airborne alpha or beta emitters is provided. The method includes providing a radioactive source; placing the radioactive source inside the detection volume of a CAM; and introducing an alpha or beta-emitting isotope while the CAM is in a normal functioning mode.

Moore, Murray E.; Gauss, Adam Benjamin; Justus, Alan Lawrence

2012-06-26

145

Lithium ion sources  

NASA Astrophysics Data System (ADS)

A 10.9 cm diameter lithium alumino-silicate ion source has been chosen as a source of ˜100mA lithium ion current for the Neutralized Drift Compression Experiment (NDCX-II) at LBNL. Research and development was carried out on lithium alumino-silicate ion sources prior to NDCX-II source fabrication. Space-charge-limited emission with the current density exceeding 1 mA/cm2 was measured with 0.64 cm diameter lithium alumino-silicate ion sources at 1275 °C. The beam current density is less for the first 10.9 cm diameter NDCX-II source, and it may be due to an issue of surface coverage. The lifetime of a thin coated (on a tungsten substrate) source is varied, roughly 40-50 h, when pulsed at 0.05 Hz and with pulse length of 6?s each, i.e., a duty factor of 3×10-7, at an operating temperature of 1250-1275 °C. The 10.9 cm diameter source lifetime is likely the same as of a 0.64 cm source, but the lifetime of a source with a 2 mm diameter (without a tungsten substrate) is 10-15 h with a duty factor of 1 (DC extraction). The lifetime variation is dependent on the amount of deposition of ?-eucryptite mass, and the surface temperature. The amount of mass deposition does not significantly alter the current density. More ion source work is needed to improve the large source performance.

Roy, Prabir K.; Greenway, Wayne G.; Grote, Dave P.; Kwan, Joe W.; Lidia, Steven M.; Seidl, Peter A.; Waldron, William L.

2014-01-01

146

High current ion sources  

SciTech Connect

The concept of high current ion source is both relative and evolutionary. Within the domain of one particular kind of ion source technology a current of microamperers might be high', while in another area a current of 10 Amperes could low'. Even within the domain of a single ion source type, what is considered high current performance today is routinely eclipsed by better performance and higher current output within a short period of time. Within their fields of application, there is a large number of kinds of ion sources that can justifiably be called high current. Thus, as a very limited example only, PIGs, Freemen sources, ECR sources, duoplasmatrons, field emission sources, and a great many more all have their high current variants. High current ion beams of gaseous and metallic species can be generated in a number of different ways. Ion sources of the kind developed at various laboratories around the world for the production of intense neutral beams for controlled fusion experiments are used to form large area proton deuteron beams of may tens of Amperes, and this technology can be used for other applications also. There has been significant progress in recent years in the use of microwave ion sources for high current ion beam generation, and this method is likely to find wide application in various different field application. Finally, high current beams of metal ions can be produced using metal vapor vacuum arc ion source technology. After a brief consideration of high current ion source design concepts, these three particular methods are reviewed in this paper.

Brown, I.G.

1989-06-01

147

Future Synchrotron Radiation Sources  

Microsoft Academic Search

Sources of synchrotron radiation (also called synchrotron light) and their associated research facilities have experienced a spectacular growth in number, performance, and breadth of application in the past two to three decades. In 1978 there were eleven electron storage rings used as light sources. Three of these were small rings, all below 500 mega-electron volts (MeV), dedicated to this purpose;

Winick

2003-01-01

148

Equivariant adaptive source separation  

Microsoft Academic Search

Source separation consists of recovering a set of independent signals when only mixtures with unknown coefficients are observed. This paper introduces a class of adaptive algorithms for source separation that implements an adaptive version of equivariant estimation and is henceforth called equivariant adaptive separation via independence (EASI). The EASI algorithms are based on the idea of serial updating. This specific

Jean-françois Cardoso; Beate Hvam Laheld

1996-01-01

149

Using Primary Source Documents.  

ERIC Educational Resources Information Center

Explores the use of primary sources when teaching about U.S. slavery. Includes primary sources from the Gilder Lehrman Documents Collection (New York Historical Society) to teach about the role of slaves in the Revolutionary War, such as a proclamation from Lord Dunmore offering freedom to slaves who joined his army. (CMK)

Mintz, Steven

2003-01-01

150

Virtual real source  

Microsoft Academic Search

Estimation of the seismic source signature is an important problem in reflection seismology. Existing methods of source signature estimation (statistical meth- ods and well-log-based methods) suffer from several drawbacks. For example, assumptions of whiteness of the earth response, stationarity of the data, and the phase characteristics of the wavelet have no real theoretical justification and the extracted wavelets may not

Jyoti Behura

2007-01-01

151

Linear light source reflectometry  

Microsoft Academic Search

This paper presents a technique for estimating the spatially-varying reflectance properties of a surface based on its appearance during a single pass of a linear light source. By using a linear light rather than a point light source as the illuminant, we are able to reliably observe and estimate the diffuse color, specular color, and specular roughness of each point

Andrew Gardner; Chris Tchou; Tim Hawkins; Paul E. Debevec

2003-01-01

152

Energy Sources and Development.  

ERIC Educational Resources Information Center

This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with energy sources and development. Its objective is for the student to be able to discuss energy sources and development related to the historical perspective, biological development, current aspects, and future expectations…

Crank, Ron

153

Sources of Instructional Leadership.  

ERIC Educational Resources Information Center

This study assessed patterns of instructional leadership sources. The instrument, Sources of Instructional Leadership (SOIL), was based on instructional leadership and effective schools literature. It dealt with the management of instructional resources, and related to one of six leadership functions: organizing, coordinating, developing,…

Selim, Philip D.

154

Crystallography: Sources of inspiration  

NASA Astrophysics Data System (ADS)

Synchrotrons have long been the preferred X-ray sources for crystallography, but competition has arrived with the advent of X-ray free-electron lasers. A synchrotron expert and an advocate of free-electron lasers discuss the prospects of the respective source types for applications in structural biology.

McSweeney, Sean; Fromme, Petra

2014-01-01

155

Peristaltic ion source.  

National Technical Information Service (NTIS)

Conventional ion sources generate energetic ion beams by accelerating the plasma-produced ions through a voltage drop at the extractor, and since it is usual that the ion beam is to propagate in a space which is at ground potential, the plasma source is b...

I. G. Brown A. Anders S. Anders M. R. Dickinson R. A. MacGill

1995-01-01

156

Creating Open Source Conversation  

ERIC Educational Resources Information Center

Darien Library, where the author serves as head of knowledge and learning services, launched a new website on September 1, 2008. The website is built with Drupal, an open source content management system (CMS). In this article, the author describes how she and her colleagues overhauled the library's website to provide an open source content…

Sheehan, Kate

2009-01-01

157

Bayesian Radiation Source Localization  

Microsoft Academic Search

We present an approach to localizing radiological sources that uses numerical adjoints and a Bayesian formulation and demonstrate the approach on two simple example scenarios. Results indicate accurate estimates of source locations. We briefly study the effect of neglecting the contribution of all scattered radiation in the adjoints, as analytical transport approximations do, for a case with moderately attenuating material

Kenneth D. Jarman; Richard S. Wittman; Erin A. Miller; Christopher J. Gesh

2010-01-01

158

Semiconductor quantum light sources  

Microsoft Academic Search

Lasers and LEDs have a statistical distribution in the number of photons emitted within a given time interval. Applications exploiting the quantum properties of light require sources for which either individual photons, or pairs, are generated in a regulated stream. Here we review recent research on single-photon sources based on the emission of a single semiconductor quantum dot. In just

Andrew J. Shields

2007-01-01

159

Industrial ion source technology  

Microsoft Academic Search

Plasma probe surveys were conducted in a 30-cm source to verify that the uniformity in the ion beam is the result of a corresponding uniformity in the discharge-chamber plasma. A 15 cm permanent magnet multipole ion source was designed, fabricated, and demonstrated. Procedures were investigated for texturing a variety of seed and surface materials for controlling secondary electron emission, increasing

H. R. Kaufman

1977-01-01

160

Industrial Ion Source Technology.  

National Technical Information Service (NTIS)

Plasma probe surveys were conducted in a 30-cm source to verify that the uniformity in the ion beam is the result of a corresponding uniformity in the discharge-chamber plasma. A 15 cm permanent magnet multipole ion source was designed, fabricated, and de...

H. R. Kaufman

1977-01-01

161

Photonic crystal light source  

SciTech Connect

A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

Fleming, James G. (Albuquerque, NM); Lin, Shawn-Yu (Albuquerque, NM); Bur, James A. (Corrales, NM)

2004-07-27

162

Neutron sources and applications  

SciTech Connect

Review of Neutron Sources and Applications was held at Oak Brook, Illinois, during September 8--10, 1992. This review involved some 70 national and international experts in different areas of neutron research, sources, and applications. Separate working groups were asked to (1) review the current status of advanced research reactors and spallation sources; and (2) provide an update on scientific, technological, and medical applications, including neutron scattering research in a number of disciplines, isotope production, materials irradiation, and other important uses of neutron sources such as materials analysis and fundamental neutron physics. This report summarizes the findings and conclusions of the different working groups involved in the review, and contains some of the best current expertise on neutron sources and applications.

Price, D.L. [ed.] [Argonne National Lab., IL (United States); Rush, J.J. [ed.] [National Inst. of Standards and Technology, Gaithersburg, MD (United States)

1994-01-01

163

Pulsed plasma electron sources  

NASA Astrophysics Data System (ADS)

There is a continuous interest in research of electron sources which can be used for generation of uniform electron beams produced at E<=105 V/cm and duration <=10-5 s. In this review, several types of plasma electron sources will be considered, namely, passive (metal ceramic, velvet and carbon fiber with and without CsI coating, and multicapillary and multislot cathodes) and active (ferroelectric and hollow anodes) plasma sources. The operation of passive sources is governed by the formation of flashover plasma whose parameters depend on the amplitude and rise time of the accelerating electric field. In the case of ferroelectric and hollow-anode plasma sources the plasma parameters are controlled by the driving pulse and discharge current, respectively. Using different time- and space-resolved electrical, optical, spectroscopical, Thomson scattering and x-ray diagnostics, the parameters of the plasma and generated electron beam were characterized.

Krasik, Ya. E.; Yarmolich, D.; Gleizer, J. Z.; Vekselman, V.; Hadas, Y.; Gurovich, V. Tz.; Felsteiner, J.

2009-05-01

164

Pulsed ion beam source  

DOEpatents

An improved pulsed ion beam source having a new biasing circuit for the fast magnetic field. This circuit provides for an initial negative bias for the field created by the fast coils in the ion beam source which pre-ionize the gas in the source, ionize the gas and deliver the gas to the proper position in the accelerating gap between the anode and cathode assemblies in the ion beam source. The initial negative bias improves the interaction between the location of the nulls in the composite magnetic field in the ion beam source and the position of the gas for pre-ionization and ionization into the plasma as well as final positioning of the plasma in the accelerating gap. Improvements to the construction of the flux excluders in the anode assembly are also accomplished by fabricating them as layered structures with a high melting point, low conductivity material on the outsides with a high conductivity material in the center.

Greenly, John B. (Lansing, NY)

1997-01-01

165

Industrial ion source technology  

NASA Technical Reports Server (NTRS)

A 30 cm electron bombardment ion source was designed and fabricated for micromachining and sputtering applications. This source has a multipole magnetic field that employs permanent magnets between permeable pole pieces. An average ion current density of 1 ma/sq cm with 500 eV argon ions was selected as a design operating condition. The ion beam at this operating condition was uniform and well collimated, with an average variation of plus or minus 5 percent over the center 20 cm of the beam at distances up to 30 cm from the ion source. A variety of sputtering applications were undertaken with a small 10 cm ion source to better understand the ion source requirements in these applications. The results of these experimental studies are also included.

Kaufman, H. R.

1976-01-01

166

Pulsed plasma electron sources  

SciTech Connect

There is a continuous interest in research of electron sources which can be used for generation of uniform electron beams produced at E{<=}10{sup 5} V/cm and duration {<=}10{sup -5} s. In this review, several types of plasma electron sources will be considered, namely, passive (metal ceramic, velvet and carbon fiber with and without CsI coating, and multicapillary and multislot cathodes) and active (ferroelectric and hollow anodes) plasma sources. The operation of passive sources is governed by the formation of flashover plasma whose parameters depend on the amplitude and rise time of the accelerating electric field. In the case of ferroelectric and hollow-anode plasma sources the plasma parameters are controlled by the driving pulse and discharge current, respectively. Using different time- and space-resolved electrical, optical, spectroscopical, Thomson scattering and x-ray diagnostics, the parameters of the plasma and generated electron beam were characterized.

Krasik, Ya. E.; Yarmolich, D.; Gleizer, J. Z.; Vekselman, V.; Hadas, Y.; Gurovich, V. Tz.; Felsteiner, J. [Department of Physics, Technion, 32000 Haifa (Israel)

2009-05-15

167

A dynamic infrared source  

NASA Astrophysics Data System (ADS)

A system is described that can be used for testing infrared focal plane cameras in situations where conventional blackbody sources are deficient. The system uses readily available components, electronics, and software. It can provide either a wide area or a point source of infrared flux that can be programmed to follow a prescribed temporal profile at higher rates than available from commercial blackbody sources and with excellent repeatability. Additionally, the system provides flux without suffering from the temporal noise characteristic of commercial, wide area, flat sheet sources that results from turbulence in front of the blackbody. The system consists of commercially available, rapid rise time infrared radiators, either coupled to an integrating sphere for broad area flux, or used individually with a pinhole and collimator as a point source. A programmable voltage supply provides the power versus time profile at frequencies to several Hertz. Transfer from a standard blackbody calibrates the flux levels. This article provides a description, testing results, and application examples.

Persky, M. J.

2003-12-01

168

Timing Atoll Sources  

NASA Astrophysics Data System (ADS)

We studied the correlated X-ray spectral and timing behaviour of the atoll sources 4U 0614+09 and 4U 1728-34 and demonstrate that the frequencies of the variability components of these two sources follow a universal scheme of correlations relatively independent of source luminosity. Most frequencies, from 0.1 to 1200 Hz, vary in a strongly correlated fashion, but one is nearly constant near 150 Hz. The transient source 4U 1608-52, previously classified as an atoll source but recently reported to trace a Z track in the color diagram, is found by us to exactly conform to this same universal atoll frequency correlation scheme, suggesting a very similar accretion flow configuration. A similar study of the millisecond X-ray pulsar SAX J1808.4-3658 is currently in progress, which indicates that some discrepancies occur in that source, perhaps related to a stronger magnetic field or a different spin in the pulsar as compared to the other atoll sources.

van Straaten, S.; van der Klis, M.; Wijnands, R.

2003-03-01

169

Trans-Z-source inverters  

Microsoft Academic Search

This paper extends the impedance-source (Z-source) inverters concept to the transformer based Z-source (trans-Z-source) inverters. The original Z-source inverter (ZSI) employs an impedance network of two inductors and two capacitors connected in a special arrangement to interface the dc source and the inverter bridge. It has overcome the conceptual limitations of the traditional voltage-source inverter and the current-source inverter. In

Wei Qian; Fang Zheng Peng; Honnyong Cha

2010-01-01

170

MEG source detection revisited  

NASA Astrophysics Data System (ADS)

Magnetoencephalography (MEG) is a multi-channel imaging technique. It uses an array composed of a large number of Superconducting Quantum Interference Device (SQUID) to measure the magnetic fields produced by the primary electric currents inside the brain. The measured spatio-temporal magnetic fields are then used to estimate the locations and strengths of these electric currents, often known as MEG sources. The estimated quantities are finally superimposed with the images generated by magnetic resonance imaging (MRI). The combination of information from MEG and MRI forms the magnetic source image (MSI). A great variety of signal processing and modeling techniques such as Inverse problem, Subspace approach, Independent component analysis (ICA) method, and Beamforming (BF) are used to estimate these sources. The first three approaches require the number of sources be detected a priori. Several shortcomings exist in the currently used methods for detecting the source number. First, the source detection is completed only after - not before - MSI is generated. Secondly, the detection methods are somewhat subjective. In order to provide a solution to the problem of detecting MEG source number for all these approaches, a novel method is developed. The covariance matrix of MEG measurements over all channels is decomposed into the signal and the noise subspaces. The number of sources is shown to be equal to the dimension of the signal subspace. The selection of this dimension is translated into a problem of determining the order of the underlying statistics. This statistical identification is resolved by using Information theoretic criteria which are derived based on Kullback-Leibler divergence. Because the method utilizes originally acquired MEG measurements and implemented before magnetic source images are generated, it is an entirely data-driven approach, more efficient, and less likely to be subjective.

Lei, Tianhu; Roberts, Timothy P. L.

2010-03-01

171

LBL/Industry Heterogeneous Reservoir Performance Definition Project  

SciTech Connect

In this paper the investigator discusses hydrologic and seismic characterization of a fractured limestone and shale/sandstone formations based on a set of interference test data and vertical seismic profile (VSP)/tomographic imaging. Numerical inversions have been carried to build conceptual models for the Ft. Riley formation based on ``equivalent discontinuum`` and ``variable aperture continuum`` approaches. The analysis suggests the following conclusions: Stochastic inverse approaches were successful in reproducing the transient pressure behavior at the pumping and observation wells and appear to be viable means for characterizing fractured formation. The conceptual models for the Ft. Riley formation derived based on both continuum as well as discontinuum approaches indicate presence of a preferential pathway between wells GW-2 and GW-5 to the north of well GW-3. An attempt was made to verify the conceptual models by predicting the build data during the test Pump 58. The field data was affected by rainfall; however, the conceptual models appear to generate the expected trend. Multi-component VSP is useful for determining fracture orientation. High frequency (up to 5000 hz) imaging of the subsurface is possible at moderate scales (few hundred meters). P-wave imaging of fractured rocks using traveltime and amplitude studies give useful information on fracture density, location, and orientation.

Benson, S.M.; Majer, E.L.; Long, J.C.S.

1993-12-31

172

Pulsed ion beam source  

DOEpatents

An improved magnetically-confined anode plasma pulsed ion beam source. Beam rotation effects and power efficiency are improved by a magnetic design which places the separatrix between the fast field flux structure and the slow field structure near the anode of the ion beam source, by a gas port design which localizes the gas delivery into the gap between the fast coil and the anode, by a pre-ionizer ringing circuit connected to the fast coil, and by a bias field means which optimally adjusts the plasma formation position in the ion beam source.

Greenly, John B. (Lansing, NY)

1996-01-01

173

Nuclear electric power sources  

NASA Technical Reports Server (NTRS)

Measurements on radioactive commercial p-n junction silicon cells show that these units are capable of delivering several hundred microwatts per curie of Am-241 alpha source, indicating their usefulness in such electronic devices as hearing aids, heart pacemakers, electronic watches, delay timers and nuclear dosimeter chargers. It is concluded that the Am-241 sources are superior to the beta sources used previously, because of higher alpha specific ionization and simultaneous production of low energy photons which are easily converted into photoelectrons for additional power.

Singh, J. J.

1978-01-01

174

Microfabricated diffusion source  

DOEpatents

A microfabricated diffusion source to provide for a controlled diffusion rate of a vapor comprises a porous reservoir formed in a substrate that can be filled with a liquid, a headspace cavity for evaporation of the vapor therein, a diffusion channel to provide a controlled diffusion of the vapor, and an outlet to release the vapor into a gas stream. The microfabricated diffusion source can provide a calibration standard for a microanalytical system. The microanalytical system with an integral diffusion source can be fabricated with microelectromechanical systems technologies.

Oborny, Michael C. (Albuquerque, NM) [Albuquerque, NM; Frye-Mason, Gregory C. (Cedar Crest, NM) [Cedar Crest, NM; Manginell, Ronald P. (Albuquerque, NM) [Albuquerque, NM

2008-07-15

175

Darwin: Open Source  

NSDL National Science Digital Library

On March 16th, 1999, Apple computer made two announcements that indicate radical changes in the direction of its OS. One of these announcements was that Apple is releasing the source code to portions of Mac OS X server. The project, called Darwin, has not only released the foundation layers of the operating system, but established a system of user-contributed modifications to the source. Modeled after Linux and Apache, this new direction by Apple has been embraced by Eric Raymond, President of the Open Source Initiative.

176

Public Geospatial Data Sources  

NASA Astrophysics Data System (ADS)

In recent years there has been tremendous progress in the field of software for managing geographic information (GIS - Geographic Information System). Data processing capabilities expand with every new version of GIS applications. Similarly, the processing power of computers to process and manage geographic data. Once we have got such a powerful tool, the question arises: where to get the relevant data from? There are many sources of data (public, paid for), but after closer examination it turns out that they are mostly processed data from other sources. In this article I will present the primary source of data that can be used to suit one's needs. All of these data are publicly available

Nering, Konrad

2013-12-01

177

Biographical Sources for Astronomers  

NASA Astrophysics Data System (ADS)

This paper describes the different types of published sources for biographical data from the history of astronomy - well known ones like encyclopaedias, biographical dictionaries, and obituaries, as well as less known ones like membership directories of societies, annual reports, and lists of solar-system nomenclature. Also online sources such as web pages and databases are considered. Existing bio-bibliographies are discussed and a new "Biographical Index of Astronomy" (BIA) is introduced. It lists biographical and bio-bibliographical sources for more than 16,000 persons.

Dick, Wolfgang R.

2006-12-01

178

Thermovoltaic Power Source.  

National Technical Information Service (NTIS)

A thermophotovoltaic power source comprising a Cassegrain solar collector and concentrator, a thermal vessel including a containment vessel holding thermal storage material therein, the containment vessel having the shape of an annulus closed at one end a...

J. G. Severns

1982-01-01

179

Calcium source (image)  

MedlinePLUS

Getting enough calcium to keep bones from thinning throughout a person's life may be made more difficult if that person has ... as a tendency toward kidney stones, for avoiding calcium-rich food sources. Calcium deficiency also effects the ...

180

National Synchrotron Light Source  

SciTech Connect

A tour of Brookhaven's National Synchrotron Light Source (NSLS). The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviole

2009-03-10

181

Sources for Animal Biodiversity  

Microsoft Academic Search

As ecological and human pressures on animal populations increase, so does the discussion of the importance of animal biodiversity. This paper presents sources that can be used to research animal biodiversity and related topics.

Margaret A. Mellinger

2004-01-01

182

High Yield Neutron Source.  

National Technical Information Service (NTIS)

A high yield neutron source comprising a plasma focus device in combination with a structured target is described. The plasma focus device generates a plasma sheath which focuses on a structured target in a predetermined focal region. The structured targe...

H. L. Sahlin J. H. Brownell B. L. Freeman

1978-01-01

183

EXPLORING ALTERNATIVE ENERGY SOURCES  

NSDL National Science Digital Library

Students do research to determine the types of energy currently used in the U.S., study the economic effects of rising energy costs on average households, and come up with ideas for alternative energy sources.

Lisa Prososki (;)

2007-09-25

184

Alternative fuel information sources  

SciTech Connect

This short document contains a list of more than 200 US sources of information (Name, address, phone number, and sometimes contact) related to the use of alternative fuels in automobiles and trucks. Electric-powered cars are also included.

Not Available

1994-06-01

185

OLED Area Illumination Source.  

National Technical Information Service (NTIS)

The present invention relates to an area illumination light source comprising a plurality of individual OLED panels. The individual OLED panels are configured in a physically modular fashion. Each OLED panel comprising a plurality of OLED devices. Each OL...

A. R. Duggal D. F. Foust J. J. Shiang W. F. Nealon

2004-01-01

186

National Synchrotron Light Source  

ScienceCinema

A tour of Brookhaven's National Synchrotron Light Source (NSLS). The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviole

None

2010-01-08

187

Sources of Assistance.  

ERIC Educational Resources Information Center

Information about materials on environmental scanning is offered. Suggestions about sources of data for scanning are provided, organized into six facets of the environment: demographic, economic, political, organizational, technological, and social-cultural. (MLW)

Ahumada, Martin M.; Hefferlin, JB Lon

1986-01-01

188

Nonclassical Matter Wave Sources.  

National Technical Information Service (NTIS)

The general goal of our research is the generation, manipulation, and characterization of coherent and nonclassical matter-wave sources. The research has both a theoretical and an experimental component. Theoretical achievements include the use of nonline...

P. Meystre P. Jessen

2004-01-01

189

Galactic Superluminal Sources  

NASA Technical Reports Server (NTRS)

A new class of X-ray sources was clearly established with the discovery of highly relativistic radio jets from the galactic sources GRS 1915+105 and GRO J1655-40. Both of these objects have given us a broader view of black holes and the formation of jets, yet they also show the complexity of the accretion environment near relativistic objects. The fast apparent motion of the jets, their luminosity and variability, high energy spectrum, and approximate scaling to the behavior of active galactic nuclei, certainly warrant the description 'microquasar". I present a review of the observational data on these sources, and discuss where we stand on a physical picture of GRS 1915+105 and GRO J1655-40 as taken from multi-wavelength studies. I also point out other galactic sources which share some of the properties of the microquasars, and what to look for as a high energy "signature' in future observations.

Harmon, B. A.

1998-01-01

190

Galactic Superluminal Sources  

NASA Technical Reports Server (NTRS)

A new class of X-ray sources was clearly established with the discovery of highly relativistic radio jets from the two galactic sources GRS 1915+105 and GRO Jl655-40. Both of these objects have given us a broader view of black holes and the formation of jets, yet they also show the complexity of the accretion environment near relativistic objects. The fast apparent motion of the jets, their luminosity and variability, their high energy spectrum, and approximately scaling to the behavior of active galactic nuclei, certainly warrant the description "microquasar". A review of the observational data on these sources is presented, and where we stand on a physical picture of GRS 1915+105 and GRO J165540 as taken from multi-wavelength studies is also discussed. Other galactic sources which share some of the properties of the microquasars, and what to look for as a high energy "signature" in future observations is also discussed.

Harmon, B. Alan

1998-01-01

191

Bayesian Radiation Source Localization  

SciTech Connect

Locating illicit radiological sources using gamma ray or neutron detection is a key challenge for both homeland security and nuclear nonproliferation. Localization methods using an array of detectors or a sequence of observations in time and space must provide rapid results while accounting for a dynamic attenuating environment. In the presence of significant attenuation and scatter, more extensive numerical transport calculations in place of the standard analytical approximations may be required to achieve accurate results. Numerical adjoints based on deterministic transport codes provide relatively efficient detector response calculations needed to determine the most likely location of a true source. Probabilistic representations account for uncertainty in the source location resulting from uncertainties in detector responses, the approximations that are used, and the potential for nonunique solutions. A Bayesian approach improves on previous likelihood methods for source localization by allowing the incorporation of all available information to help constrain solutions.

Jarman, Kenneth D.; Miller, Erin A.; Wittman, Richard S.; Gesh, Christopher J.

2011-07-01

192

Permutation codes for sources.  

NASA Technical Reports Server (NTRS)

Source encoding techniques based on permutation codes are investigated. For a broad class of distortion measures it is shown that optimum encoding of a source permutation code is easy to instrument even for very long block lengths. Also, the nonparametric nature of permutation encoding is well suited to situations involving unknown source statistics. For the squared-error distortion measure a procedure for generating good permutation codes of a given rate and block length is described. The performance of such codes for a memoryless Gaussian source is compared both with the rate-distortion function bound and with the performance of various quantization schemes. The comparison reveals that permutation codes are asymptotically ideal for small rates and perform as well as the best entropy-coded quantizers presently known for intermediate rates. They can be made to compare favorably at high rates, too, provided the coding delay associated with extremely long block lengths is tolerable.

Berger, T.; Jelinek, F.; Wolf, J. K.

1972-01-01

193

Improved Negative Ion Source.  

National Technical Information Service (NTIS)

A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cyclo...

J. E. Delmore

1984-01-01

194

Air pollution source identification  

NASA Technical Reports Server (NTRS)

Techniques for air pollution source identification are reviewed, and some results obtained with them are evaluated. Described techniques include remote sensing from satellites and aircraft, on-site monitoring, and the use of injected tracers and pollutants themselves as tracers. The use of a large number of trace elements in ambient airborne particulate matter as a practical means of identifying sources is discussed in detail. Sampling and analysis techniques are described, and it is shown that elemental constituents can be related to specific source types such as those found in the earth's crust and those associated with specific industries. Source identification sytems are noted which utilize charged particle X-ray fluorescence analysis of original field data.

Fordyce, J. S.

1975-01-01

195

Air pollution source identification  

NASA Technical Reports Server (NTRS)

The techniques available for source identification are reviewed: remote sensing, injected tracers, and pollutants themselves as tracers. The use of the large number of trace elements in the ambient airborne particulate matter as a practical means of identifying sources is discussed. Trace constituents are determined by sensitive, inexpensive, nondestructive, multielement analytical methods such as instrumental neutron activation and charged particle X-ray fluorescence. The application to a large data set of pairwise correlation, the more advanced pattern recognition-cluster analysis approach with and without training sets, enrichment factors, and pollutant concentration rose displays for each element is described. It is shown that elemental constituents are related to specific source types: earth crustal, automotive, metallurgical, and more specific industries. A field-ready source identification system based on time and wind direction resolved sampling is described.

Fordyce, J. S.

1975-01-01

196

Casimir light: the source.  

PubMed Central

The release of Casimir energy in filling a dielectric hole is identified as the source of coherent sonoluminescence. Qualitative agreement with recently acquired data is found for the magnitude and shape of the spectrum.

Schwinger, J

1993-01-01

197

Polygonal Light Source Estimation  

Microsoft Academic Search

\\u000a This paper studies the problem of light estimation using a specular sphere. Most existing work on light estimation assumes\\u000a distant point light sources, while this work considers an area light source which is estimated in 3D space by reconstructing\\u000a its edges. An empirical analysis on existing methods for line estimation from a single view is carried out, and it is

Dirk Schnieders; Kwan-Yee Kenneth Wong; Zhenwen Dai

2009-01-01

198

Diversification of energy sources  

NASA Technical Reports Server (NTRS)

The concept of energy source diversification was introduced as a substitution conservation action. The current status and philosophy behind a diversification program is presented in the context of a national energy policy. Advantages, disadvantages (constraints), and methods of implementation for diversification are discussed. The energy source systems for diversification are listed and an example impact assessment is outlined which deals with the water requirements of the specific energy systems.

1975-01-01

199

National Synchrotron Light Source  

ScienceCinema

A tour of Brookhaven's National Synchrotron Light Source (NSLS), hosted by Associate Laboratory Director for Light Sources, Stephen Dierker. The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviolet, and x-ray light for basic and applied research in physics, chemistry, medicine, geophysics, environmental, and materials sciences.

200

Field emission electron source  

DOEpatents

A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

Zettl, Alexander Karlwalter (Kensington, CA); Cohen, Marvin Lou (Berkeley, CA)

2000-01-01

201

Magnetron sputtering source  

DOEpatents

A magnetron sputtering source for sputtering coating substrates includes a high thermal conductivity electrically insulating ceramic and magnetically attached sputter target which can eliminate vacuum sealing and direct fluid cooling of the cathode assembly. The magnetron sputtering source design results in greater compactness, improved operating characteristics, greater versatility, and low fabrication cost. The design easily retrofits most sputtering apparatuses and provides for safe, easy, and cost effective target replacement, installation, and removal.

Makowiecki, Daniel M. (Livermore, WA); McKernan, Mark A. (Livermore, CA); Grabner, R. Fred (Brentwood, CA); Ramsey, Philip B. (Livermore, CA)

1994-01-01

202

The 4X source  

Microsoft Academic Search

In connection with work conducted on the 4X source, it was found necessary to increase the size of the small-angle source (SAS) discharge chamber. The enlargement of the discharge chamber was necessary to accommodate the 5.4-mm-diam circular emitter needed to produce a 0.01 pi-cm-mrad emittance for the assumed H(-) ion temperature of 4 eV. Attention is given to a schematic

H. Vernon Smith; Paul Allison; J. D. Sherman

1985-01-01

203

National Synchrotron Light Source  

ScienceCinema

A tour of Brookhaven's National Synchrotron Light Source (NSLS), hosted by Associate Laboratory Director for Light Sources, Stephen Dierker. The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviolet, and x-ray light for basic and applied research in physics, chemistry, medicine, geophysics, environmental, and materials sciences.

BNL

2009-09-01

204

Plasma source of ions  

SciTech Connect

The plasma source is generated by a Penning discharge in a system with a hollow cathode and provides an ion current of up to 20 mA at an extracting voltage of 20 kV. A discharge current of 200 mA is produced. The ion source, as described by the author, is provided with a replaceable hollow cathode and an exchangeable torus-shaped insert in the emitter cathode.

Semenov, A.P.

1985-03-01

205

Tunable marine seismic source  

SciTech Connect

The disclosed device is a marine seismic source which emits a constantly varying FM signal in the 10 to 100 H /SUB z/ range. The seismic source utilizes an adjustable length cantilever spring rotatably attached to stiff acoustic radiators, which create a signal in the water. Varying the length of the cantilever spring as a function of the frequency will permit the device to be continuously tuned for maximum power output.

Mifsud, J. F.

1985-12-10

206

Lossy Source Coding  

Microsoft Academic Search

Lossy coding of speech, high-quality audio, stillimages, and video is commonplace today. However, in 1948, fewlossy compression systems were in service. Shannon introducedand developed the theory of source coding with a fidelity criterion,also called rate-distortion theory. For the first 25 years of itsexistence, rate-distortion theory had relatively little impact onthe methods and systems actually used to compress real sources.Today, however,

T. Berger; J. D. Gibson

1998-01-01

207

Magnetron sputtering source  

DOEpatents

A magnetron sputtering source for sputtering coating substrates includes a high thermal conductivity electrically insulating ceramic and magnetically attached sputter target which can eliminate vacuum sealing and direct fluid cooling of the cathode assembly. The magnetron sputtering source design results in greater compactness, improved operating characteristics, greater versatility, and low fabrication cost. The design easily retrofits most sputtering apparatuses and provides for safe, easy, and cost effective target replacement, installation, and removal. 12 figs.

Makowiecki, D.M.; McKernan, M.A.; Grabner, R.F.; Ramsey, P.B.

1994-08-02

208

Photoacoustic Point Source  

SciTech Connect

We investigate the photoacoustic effect generated by heat deposition at a point in space in an inviscid fluid. Delta-function and long Gaussian optical pulses are used as sources in the wave equation for the displacement potential to determine the fluid motion. The linear sound-generation mechanism gives bipolar photoacoustic waves, whereas the nonlinear mechanism produces asymmetric tripolar waves. The salient features of the photoacoustic point source are that rapid heat deposition and nonlinear thermal expansion dominate the production of ultrasound.

Calasso, Irio G.; Craig, Walter; Diebold, Gerald J.

2001-04-16

209

Microlensing of Large Sources  

NASA Astrophysics Data System (ADS)

We prove an approximate gravitational lensing theorem: the magnification of a source of uniform brightness by a foreground spherical lens is ?=1+?(2R2E-R2L)/A, where A is the area of the source and RE and RL are the Einstein radius and size of the lens projected into the source plane; this provides an accurate approximation to the exact magnification for R2L, R2E<source or position of the lens (except near the edges). We show that this formula can be generalized to include limb darkening of a circular source by simply inserting the surface brightness at the position of the foreground object (divided by the average surface brightness of the star). We also show that similar formulae apply for a point-mass lens contained in a shear field and mass sheet and for an ensemble of point masses, as long as the Einstein radii are much smaller than the source size. This theorem can be used to compute transit or microlensing light curves for which the foreground star or planet has a size and Einstein radius much smaller than the background star.

Agol, Eric

2003-09-01

210

Radiation source search toolkit  

NASA Astrophysics Data System (ADS)

The newly developed Radiation Source Search Toolkit (RSST) is a toolkit for generating gamma-ray spectroscopy data for use in the testing of source search algorithms. RSST is designed in a modular fashion to allow for ease of use while still maintaining accuracy in developing the output spectra. Users are allowed to define a real-world path for mobile radiation detectors to travel as well as radiation sources for possible detection. RSST can accept measured or simulated radiation spectrum data for generation into a source search simulation. RSST handles traversing the path, computing distance related attenuation, and generating the final output spectra. RSST also has the ability to simulate anisotropic shielding as well as traffic conditions that would impede a ground-based detection platform in a real-world scenario. RSST provides a novel fusion between spectral data and geospatial source search data generation. By utilizing the RSST, researchers can easily generate multiple datasets for testing detection algorithms without the need for actual radiation sources and mobile detector platforms.

Young, Jason S.

211

Internet Medieval Source Book  

NSDL National Science Digital Library

Paul Halsall, sources editor for the Online Reference Book for Medieval Studies, has recently created the Internet Medieval Source Book, a compendium of extracts and full text documents in Medieval History. Subjects covered include the end of the Classical World, Byzantium, Islam, formation and flowering of Latin Christendom, the Late Middle Ages, the Italian Renaissance, and the Early Reformation. Selected extracts are accompanied by short explanations, which help the reader to understand their context. The Source Book also contains links to a large number of medieval and religious sources, particularly strong with respect to Byzantine links. The purpose, scope and rationale behind the Source Book are explained clearly and concisely. The volume of texts and extracts, as well as the organization of the site, make this one of the premier Internet Medieval Studies sites. Note that all links of the Source Book and its links page are contained on two very large HTML pages, so users should be patient when navigating back and forth. http://www.fordham.edu/halsall/sbook.html Medieval Links: http://www.fordham.edu/halsall/med/medweb.html Online Reference Book to Medieval Studies: http://kuhttp.cc.ukans.edu/kansas/orb/mainpage.html

212

Workshop on detectors for third-generation synchrotron sources: Proceedings  

SciTech Connect

The aims of the workshop were (1) to acquaint APS users with current R and D being carried out on detectors, (2) to identify new detector systems possible during the next five years, (3) to identify new detectors theoretically possible in the future, (4) to stimulate interactions between user groups and detector developers, and (5) to obtain recommendations from expert panels on technical issues needing resolution. Development of detectors at ESRF, Spring-8, BNL, CERN and LBL are included.

NONE

1994-12-01

213

New circumstellar cyanoacetylene sources  

NASA Astrophysics Data System (ADS)

A search for the J = 10-9 transition of cyanoacetylene (HC3N) in circumstellar molecular envelopes has resulted in new detections of CIT 6 (definite) and GL 3068 (probable). The 17 sources surveyed included a mixture of carbon-rich, oxygen-rich, and S-type stars, and the previously known source IRC + 10216. Four circumstellar shells have now been identified as sources of HC3N emission. IRC + 10216, CIT 6, and GL 3068 are cool, carbon-rich giants; the remaining object, GL 2688, which is not included in this study, consists of a much hotter supergiant surrounded by a carbon-rich nebula. It was not possible to detect HC3N from any oxygen-rich shell, including W Hydrae, once reported as an HC3N source. The prospects for extending the list of molecules and host circumstellar sources and the potential of circumstellar HC3N as a tool for the study of circumstellar shells and the chemistry of long-chain carbon molecules are discussed.

Jewell, P. R.; Snyder, L. E.

1982-04-01

214

Terahertz Schottky Multiplier Sources  

NASA Technical Reports Server (NTRS)

This viewgraph presentation reviews the multiplier source technologies and the status/Performance of THz multiplier sources. An example of a THz application is imaging radar. The presentation reviews areas of requirements for THz sources: (1) Figures of merit, (i.e., Frequency Terahertz for high resolution Bandwidth of at least 15 GHz for high range resolution Efficiency (i.e., minimize power supply requirements) (2) Output power: (i.e., Milliwatts below 800 GHz, 10s of microwatts above 1 THz, 1-2 microwatts near 2 THz (3) Mechanical--stability, compact, low mass (4) Environmental -- radiation, vibration, thermal. Several sources for 0.3 - 2 THz are reviewed: FIR lasers, quantum cascade lasers (QCL), backward-wave oscillator (BWO), and Multiplier sources. The current state of the art (SoA) is shown as Substrateless Technology. It also shows where the SoA is for devices beyond 1 THz. The presentation concludes by reviewing the options for future development, and 2 technology roadmaps

Schlecht, Erich T.

2007-01-01

215

Sources of gravitational waves  

NASA Technical Reports Server (NTRS)

Sources of low frequency gravitational radiation are reviewed from an astrophysical point of view. Cosmological sources include the formation of massive black holes in galactic nuclei, the capture by such holes of neutron stars, the coalescence of orbiting pairs of giant black holes, and various means of producing a stochastic background of gravitational waves in the early universe. Sources local to our Galaxy include various kinds of close binaries and coalescing binaries. Gravitational wave astronomy can provide information that no other form of observing can supply; in particular, the positive identification of a cosmological background originating in the early universe would be an event as significant as was the detection of the cosmic microwave background.

Schutz, Bernard F.

1989-01-01

216

The Advanced Light Source  

NSDL National Science Digital Library

A division of the Berkeley Laboratory, the Advanced Light Source (ALS) "is a national user facility that generates intense light for scientific and technological research." Students and educators can learn how ALS, with the use of one of the world's brightest sources of ultraviolet and soft X-ray beams and the world's first third generation synchrotron light source in its energy range, studies the properties of materials, trace metals, and the structures of atoms and molecules. The website features scientific highlights from the facility including its study of why alcohol and water don't mix. Scientists can find the technical specification of the storage ring, photon, and beamline parameters for the many microscopes at the facility. Visiting the User's Guide, qualified researchers can also find out how to become an ALS user.

217

Dual source heat pump  

DOEpatents

What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.

Ecker, Amir L. (Dallas, TX); Pietsch, Joseph A. (Dallas, TX)

1982-01-01

218

Information sources in engineering  

SciTech Connect

This book was designed to serve as a guide to the wide range of sources of information used by engineers. The first part of this research tool describes the major primary and secondary sources for information (including online systems) that are relevant to all engineering disciplines. The second part provides the same information for each of the 19 specific engineering disciplines, with each chapter being written by an expert in the particular branch of engineering. This new edition of a work previously published under the title Use of Engineering Literature has been completely re-written with a new team of contributors. There is greater emphasis on disciplines basic to all engineering areas, e.g., fluid mechanics, thermodynamics, and materials science. Recent developments covered include robotics, CAD/CAM systems, renewable energy sources, and the use of online systems for information retrieval.

Anthony, L.J.

1985-01-01

219

INEEL Source Water Assessment  

SciTech Connect

The Idaho National Engineering and Environmental Laboratory (INEEL) covers approximately 890 mi2 and includes 12 public water systems that must be evaluated for Source water protection purposes under the Safe Drinking Water Act. Because of its size and location, six watersheds and five aquifers could potentially affect the INEEL’s drinking water sources. Based on a preliminary evaluation of the available information, it was determined that the Big Lost River, Birch Creek, and Little Lost River Watersheds and the eastern Snake River Plain Aquifer needed to be assessed. These watersheds were delineated using the United States Geologic Survey’s Hydrological Unit scheme. Well capture zones were originally estimated using the RESSQC module of the Environmental Protection Agency’s Well Head Protection Area model, and the initial modeling assumptions and results were checked by running several scenarios using Modflow modeling. After a technical review, the resulting capture zones were expanded to account for the uncertainties associated with changing groundwater flow directions, a thick vadose zone, and other data uncertainties. Finally, all well capture zones at a given facility were merged to a single wellhead protection area at each facility. A contaminant source inventory was conducted, and the results were integrated with the well capture zones, watershed and aquifer information, and facility information using geographic information system technology to complete the INEEL’s Source Water Assessment. Of the INEEL’s 12 public water systems, three systems rated as low susceptibility (EBR-I, Main Gate, and Gun Range), and the remainder rated as moderate susceptibility. No INEEL public water system rated as high susceptibility. We are using this information to develop a source water management plan from which we will subsequently implement an INEEL-wide source water management program. The results are a very robust set of wellhead protection areas that will protect the INEEL’s public water systems yet not too conservative to inhibit the INEEL from carrying out its missions.

Sehlke, Gerald

2003-03-01

220

Intense fusion neutron sources  

NASA Astrophysics Data System (ADS)

The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 1015-1021 neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 1020 neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

Kuteev, B. V.; Goncharov, P. R.; Sergeev, V. Yu.; Khripunov, V. I.

2010-04-01

221

Intense fusion neutron sources  

SciTech Connect

The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 10{sup 15}-10{sup 21} neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 10{sup 20} neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

Kuteev, B. V. [Russian Research Centre Kurchatov Institute (Russian Federation); Goncharov, P. R.; Sergeev, V. Yu. [St. Petersburg State Polytechnic University (Russian Federation); Khripunov, V. I. [Russian Research Centre Kurchatov Institute (Russian Federation)

2010-04-15

222

Trends in source gases  

NASA Technical Reports Server (NTRS)

Source gases are defined as those gases that, by their breakdown, introduce into the stratosphere halogen, hydrogen, and nitrogen compounds that are important in stratospheric ozone destruction. Given here is an update of the existing concentration time series for chlorocarbons, nitrous oxide, and methane. Also reviewed is information on halogen containing species and the use of these data for establishing trends. Also reviewed is evidence on trends in trace gases that influence tropospheric chemistry and thus the tropospheric lifetimes of source gases, such as carbon dioxide, carbon monoxide, or nitrogen oxides. Much of the information is given in tabular form.

Ehhalt, D. H.; Fraser, P. J.; Albritton, D.; Cicerone, R. J.; Khalil, M. A. K.; Legrand, M.; Makide, Y.; Rowland, F. S.; Steele, L. P.; Zander, R.

1989-01-01

223

Source Code Library  

NSDL National Science Digital Library

At the DevX Source Code Library and the newer Sourcebank, users can download source code, algorithms, and sample applications. The Library is culled from DevX services and magazines, and resources are grouped into browseable and searchable categories. The Sourcebank collects code and related tools from sites around the Web and also is searchable and browseable. Users can limit their browsing by type of resource as well (Perl code, Java code, research papers, etc.). Perhaps needless to say, file formats are too numerous to name here.

1969-12-31

224

Download Mozilla Source  

NSDL National Science Digital Library

Netscape offers its browser source code at its Mozilla.org (discussed in the Feburary 27, 1998 Scout Report) site. The compressed code is available for Macintosh, Unix, and Windows operating systems, and is between 8.8 and 11.9 Mb. Netscape strongly points out that this is source code, not executable programs, that it is of use to developers only, and that it "will be unstable." More information about the code, as well as selected build instructions, can be obtained at the site.

1998-01-01

225

Alternative Energy Sources  

NSDL National Science Digital Library

Created by Work-Ready Electronics, a project of the Advanced Technological Education program, this module introduces students to the most common alternative energy sources that they may encounter in electronic work including fuel cells, solar power, and ultracapacitors. The module includes course materials covering each of these alternative energy sources along with three "Knowledge Probes" which provide an opportunity for students to master the objectives of the module. By clicking on "Learning Resources" at the top of the page, users will also find supplemental learning activities and additional resources for practice and research. The module also includes a glossary of terms and a notebook function.

2008-09-09

226

SNS: Spallation Neutron Source  

NSDL National Science Digital Library

The Spallation Neutron Source (SNS) is an accelerator-based neutron source currently being built by the United States Department of Energy. Users can find out about upcoming workshops, conferences, and other events dealing with the accelerator, which is scheduled to be completed in 2006. By downloading a series of materials, users can learn about SNS's benefits and mechanisms. Researchers can discover SNS's mission, instrumentation, moderators, and detectors. The website provides live video of the construction site. Visitors can also learn about employment opportunities.

227

OLED area illumination source  

DOEpatents

The present invention relates to an area illumination light source comprising a plurality of individual OLED panels. The individual OLED panels are configured in a physically modular fashion. Each OLED panel comprising a plurality of OLED devices. Each OLED panel comprises a first electrode and a second electrode such that the power being supplied to each individual OLED panel may be varied independently. A power supply unit capable of delivering varying levels of voltage simultaneously to the first and second electrodes of each of the individual OLED panels is also provided. The area illumination light source also comprises a mount within which the OLED panels are arrayed.

Foust, Donald Franklin (Scotia, NY); Duggal, Anil Raj (Niskayuna, NY); Shiang, Joseph John (Niskayuna, NY); Nealon, William Francis (Gloversville, NY); Bortscheller, Jacob Charles (Clifton Park, NY)

2008-03-25

228

River Sources and Stories  

NSDL National Science Digital Library

In this lesson students learn about the differences in precipitation levels and elevation in the regions of the Nile and its source rivers (the White Nile and the Blue Nile) and will be able to explain the importance of the source rivers to civilization in Egypt. They use the MapMachine, an online atlas, and create elevation zones and precipitation maps of Africa. As they create each map, they compare it with their outline maps to answer some questions that will allow them to compare the physical characteristics of different regions and to understand the significance of one region to an adjoining area.

229

Pulsed Source Atomic Fluorescence Spectrometry.  

National Technical Information Service (NTIS)

This review deals with the recent application of pulsed excitation sources in atomic fluorescence spectrometry. Pulsed sources are compared with continuously operated, i.e., continuous-wave (cw), sources, both theoretically and experimentally. Included ar...

J. D. Winefordner L. M. Fraser N. Omenetto

1973-01-01

230

ATLAS OF SOURCE EMISSION PARTICLES  

EPA Science Inventory

An atlas of various source emission particles characterized by electron optical techniques has been compiled for use by air pollution investigators. The particles studied were emitted by mobile, stationary, and natural sources. Sources included automobiles, manufacturing operatio...

231

Incoherent Light Sources  

NASA Astrophysics Data System (ADS)

Since the invention and industrialization of incandescent lamps at the end radiation of the 19th century electrical lighting has become a commodity in our daily life. Today, incoherent light sources are used for numerous application areas. Major improvements have been achieved over the past decades with respect to lamp efficiency (Fig. 10.1), lifetime and color properties.

Bertram, Dietrich; Born, Matthias; Jüstel, Thomas

232

SOURCE ASSESSMENT: CRUSHED STONE  

EPA Science Inventory

This report describes a study of air emissions from crushed stone production. The potential environmental effect of the source is evaluated. Crushed stone production in 1972 was 1.07 x 10 to the 8th power metric tons (1.18 x 10 to the 8th power tons), 68% of which was traprock. C...

233

Calibrated Ultrasonic Sound Source.  

National Technical Information Service (NTIS)

To calibrate an ultrasonic microphone of new design a requirement arose for a sound intensity standard at frequencies above 40 kHz. This led to the development of a piezoelectric crystal source whose acoustic output matches that of an ideal piston radiato...

R. W. Hermsen W. R. Babcock

1970-01-01

234

Craft Information Sources.  

ERIC Educational Resources Information Center

Provides a brief history of the craft movement and the American Craft Council. Information available from the American Craft Information Center is described, including bibliographic sources, reference tools, periodicals and indices, exhibition catalogs, craft registry and database, clipping file, education, business, funding, and appraising…

Hujsak, Mary Dodge

1994-01-01

235

Negative Ion Sources.  

National Technical Information Service (NTIS)

The status of research on hydrogen negative ion and heavy element sources is examined in this survey. The ranges of application and methods of producing negative ions are examined. Data on the production and annihilation cross sections of negative ions as...

M. A. Abroyan V. P. Golubev V. L. Komarov G. V. Chemyakin

1974-01-01

236

Industrial ion source technology  

NASA Technical Reports Server (NTRS)

In reactive ion etching of Si, varying amounts of O2 were added to the CF4 background. The experimental results indicated an etch rate less than that for Ar up to an O2 partial pressure of about .00006 Torr. Above this O2 pressure, the etch rate with CF4 exceeded that with Ar alone. For comparison the random arrival rate of O2 was approximately equal to the ion arrival rate at a partial pressure of about .00002 Torr. There were also ion source and ion pressure gauge maintenance problems as a result of the use of CF4. Large scale (4 sq cm) texturing of Si was accomplished using both Cu and stainless steel seed. The most effective seeding method for this texturing was to surround the sample with large inclined planes. Designing, fabricating, and testing a 200 sq cm rectangular beam ion source was emphasized. The design current density was 6 mA/sq cm with 500 eV argon ions, although power supply limitations permitted operation to only 2 mA/sq cm. The use of multiple rectangular beam ion sources for continuous processing of wider areas than would be possible with a single source was also studied. In all cases investigated, the most uniform coverage was obtained with 0 to 2 cm beam overlay. The maximum departure from uniform processing at optimum beam overlap was found to be +15%.

Kaufman, H. R.; Robinson, R. S.

1979-01-01

237

BNL Sources Development Laboratory  

SciTech Connect

The NSLS has a long-standing interest in providing the best possible synchrotron radiation sources for its user community, and hence, has recently established the Source Development Laboratory (SDL) to pursue research into fourth generation synchrotron radiation sources. A major element of the program includes development of a high peak power FEL meant to operate in the vacuum ultraviolet. The objective of the program is to develop the source, and experimental technology together to provide the greatest impact on UV science. The accelerator under construction for the SDL consists of a high brightness RF photocathode electron gun followed by a 230 MeV short pulse linac incorporating a magnetic chicane for pulse compression. The gun drive laser is a wide bandwidth Ti: Sapphire regenerative amplifier capable of pulse shaping which will be used to study non- linear emittance compensation. Using the compressor, 1 nC bunches with a length as small as 50 {mu}m sigma (2 kA peak current) are available for experiments. In this paper we briefly describe the facility and detail our plans for utilizing the 10 m long NISUS wiggler to carry out single pass FEL experiments. These include a 1 {mu}m SASE demonstration, a seeded beam demonstration at 300 nm, and a High Gain Harmonic Generation experiment at 200 mn. The application of chirped pulse amplification to this type of FEL will also be discussed.

Ben-Zvi, I.; Graves, W.; Heese, R.; Johnson, E.D.; Krinsky, S.; Yu, L.H.

1997-01-01

238

Coaxial microwave plasma source  

SciTech Connect

Physical principles underlying the operation of a pulsed coaxial microwave plasma source (micro-wave plasmatron) are considered. The design and parameters of the device are described, and results of experimental studies of the characteristics of the generated plasma are presented. The possibility of application of this type of plasmatron in gas-discharge physics is discussed.

Gritsinin, S. I. [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation); Gushchin, P. A. [Gubkin State University of Oil and Gas (Russian Federation); Davydov, A. M.; Kossyi, I. A. [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation); Kotelev, M. S. [Gubkin State University of Oil and Gas (Russian Federation)

2011-11-15

239

Free open source software  

NSDL National Science Digital Library

This site offers open source software for the fields of civil and environmental engineering. Their mission statement is "to provide an online web directory for civil & environmental engineering." Nicely organized, the site is a valuable asset for anyone interested in this subject area.

2008-10-15

240

MICROBIAL SOURCE TRACKING  

EPA Science Inventory

Fecal contamination of waters used for recreation, drinking water, and aquaculture is an environmental problem and poses significant human health risks. The problem is often difficult to correct because the source of the contamination cannot be determined with certainty. Run-of...

241

Effects of acoustic sources  

Microsoft Academic Search

An experiment was conducted to determine the effect of acoustics on the laminar flow on the side of a nacelle. A flight test was designed to meet this goal and a brief review of the purpose is given. A nacelle with a significant length of laminar flow was mounted on the wing of NASA OV-1. Two noise sources are also

James A. Schoenster; Michael G. Jones

1987-01-01

242

Focused Pulsed Neutron Source.  

National Technical Information Service (NTIS)

A non-reactor neutron source is disclosed that allows for a pulse intense current of ions to generate neutrons that are epithermal neutrons and provide low-energy neutron energy particularly suited for Boron Neutron Capture Therapy (BNCT) treatment. The p...

M. Friedman A. Drobot N. C. Wyeth

1995-01-01

243

Tandem Terminal Ion Source  

SciTech Connect

OAK-B135 Tandem Terminal Ion Source. The terminal ion source (TIS) was used in several experiments during this reporting period, all for the {sup 7}Be({gamma}){sup 8}B experiment. Most of the runs used {sup 1}H{sup +} at terminal voltages from 0.3 MV to 1.5 MV. One of the runs used {sup 2}H{sup +} at terminal voltage of 1.4 MV. The other run used {sup 4}He{sup +} at a terminal voltage of 1.37 MV. The list of experiments run with the TIS to date is given in table 1 below. The tank was opened four times for unscheduled source repairs. On one occasion the tank was opened to replace the einzel lens power supply which had failed. The 10 kV unit was replaced with a 15 kV unit. The second time the tank was opened to repair the extractor supply which was damaged by a tank spark. On the next occasion the tank was opened to replace a source canal which had sputtered away. Finally, the tank was opened to replace the discharge bottle which had been coated with aluminum sputtered from the exit canal.

None

2000-10-23

244

Open Source in Education  

ERIC Educational Resources Information Center

Educational institutions have rushed to put their academic resources and services online, beginning the global community onto a common platform and awakening the interest of investors. Despite continuing technical challenges, online education shows great promise. Open source software offers one approach to addressing the technical problems in…

Lakhan, Shaheen E.; Jhunjhunwala, Kavita

2008-01-01

245

Open-Source Colorimeter  

PubMed Central

The high cost of what have historically been sophisticated research-related sensors and tools has limited their adoption to a relatively small group of well-funded researchers. This paper provides a methodology for applying an open-source approach to design and development of a colorimeter. A 3-D printable, open-source colorimeter utilizing only open-source hardware and software solutions and readily available discrete components is discussed and its performance compared to a commercial portable colorimeter. Performance is evaluated with commercial vials prepared for the closed reflux chemical oxygen demand (COD) method. This approach reduced the cost of reliable closed reflux COD by two orders of magnitude making it an economic alternative for the vast majority of potential users. The open-source colorimeter demonstrated good reproducibility and serves as a platform for further development and derivation of the design for other, similar purposes such as nephelometry. This approach promises unprecedented access to sophisticated instrumentation based on low-cost sensors by those most in need of it, under-developed and developing world laboratories.

Anzalone, Gerald C.; Glover, Alexandra G.; Pearce, Joshua M.

2013-01-01

246

Selective ion source  

DOEpatents

A ion source is described wherein selected ions maybe extracted to the exclusion of unwanted ion species of higher ionization potential. Also described is a method of producing selected ions from a compound, such as P.sup.+ from PH.sub.3. The invention comprises a plasma chamber, an electron source, a means for introducing a gas to be ionized by electrons from the electron source, means for limiting electron energy from the electron source to a value between the ionization energy of the selected ion species and the greater ionization energy of an unwanted ion specie, and means for extracting the target ion specie from the plasma chamber. In one embodiment, the electrons are generated in a plasma cathode chamber immediately adjacent to the plasma chamber. A small extractor draws the electrons from the plasma cathode chamber into the relatively positive plasma chamber. The energy of the electrons extracted in this manner is easily controlled. The invention is particularly useful for doping silicon with P.sup.+, AS.sup.+, and B.sup.+ without the problematic presence of hydrogen, helium, water, or carbon oxide ions. Doped silicon is important for manufacture of semiconductors and semiconductor devices.

Leung, Ka-Ngo (Hercules, CA)

1996-01-01

247

Evaluating Open Source Software.  

National Technical Information Service (NTIS)

There is an overwhelming amount of open source software (OSS) available today that can be used throughout the software development life cycle. Nowadays, it is generally not a matter of whether one should use OSS, but rather, where one should use it. If on...

M. Kennedy

2010-01-01

248

Deep Source Gas Project  

SciTech Connect

The objectives of the Deep Source Gas project are to establish the existence of natural gas arising from depths in excess of 30,000 feet, to relate these occurrences to conceptual models, to define the limits of target areas, to quantify the resource, and to determine the significance of the gas to the nation's reserves. An outline of the research plan to accomplish the above objectives is presented, focused to an earth science (geology, geochemistry, and geophysics) study of the Cordilleran Geologic Province of western North America. This area is considered prospective largely due to known and suspected plate tectonic structures and their youthful emplacement (i.e., during the last 180 million years), which increases the likelihood of a timely entrapment of deep source generated hydrocarbons. Significant project results include: (1) an estimate of the deep source gas generating capacity of the Aleutian Trench area of southern Alaska (up to 212 trillion cubic feet (Tcf) during the last 20 million years alone) based on detailed geochemical studies; and (2) deep geophysical study findings of apparent fossil subduction zones (predicted to occur in the Cordillera) in western Washington. Significantly, these zones appear to have very thick sedimentary rock units, the existence of which will be evaluated through a future, more detailed seismic study and possible drilling activities. A list of future activities is included, which presents the development of a critically needed detection and differentiation system to enable segregation of suspected deep subducted origin gas from other possible sources. 13 figures.

Not Available

1984-02-01

249

Piecewise linear source separation  

NASA Astrophysics Data System (ADS)

We propose a new framework, called piecewise linear separation, for blind source separation of possibly degenerate mixtures, including the extreme case of a single mixture of several sources. Its basic principle is to: 1/ decompose the observations into "components" using some sparse decomposition/nonlinear approximation technique; 2/ perform separation on each component using a "local" separation matrix. It covers many recently proposed techniques for degenerate BSS, as well as several new algorithms that we propose. We discuss two particular methods of multichannel decompositions based on the Best Basis and Matching Pursuit algorithms, as well as several methods to compute the local separation matrices (assuming the mixing matrix is known). Numerical experiments are used to compare the performance of various combinations of the decomposition and local separation methods. On the dataset used for the experiments, it seems that BB with either cosine packets of wavelet packets (Beylkin, Vaidyanathan, Battle3 or Battle 5 filter) are the best choices in terms of overall performance because they introduce a relatively low level of artefacts in the estimation of the sources; MP introduces slightly more artefacts, but can improve the rejection of the unwanted sources.

Gribonval, Remi

2003-11-01

250

Identifying EGRET Sources.  

National Technical Information Service (NTIS)

This project was awarded funding from the CGRO program to support ROSAT and ground-based observations of unidentified sources from data obtained by the EGRET instrument on the Compton Gamma-Ray Observatory. The critical items in the project are the indivi...

E. Schlegel

2002-01-01

251

Custom uniform source system  

NASA Technical Reports Server (NTRS)

The purpose and scope of this final report is to provide information on the Custom Uniform Source System (CSTM-USS-4000). The report includes documentation and summaries of the results for the work performed under the contract. The Annex contain laboratory test findings, photographs, and drawings of the sphere system.

Balcom, John L.

1994-01-01

252

Broadband seismic energy source  

SciTech Connect

A vibratory seismic energy source capable of generating significant energy over a broad frequency band is described. The vibrating baseplate and associated structure are designed to have minimum weight while still retaining sufficient structural integrity to permit the use of high actuator forces. This, coupled with a large reaction mass results in the generation of significant energy levels in the earth at high frequencies.

Bedenbender, J.W.; Weber, R.M.

1981-03-03

253

Robust Distributed Source Coding  

Microsoft Academic Search

We consider a distributed source coding system in which several observations are communicated to the decoder using limited transmission rate. The observations must be separately coded. We introduce a robust distributed coding scheme which flexibly trades off b etween system robustness and compression efficiency. The optimality of this coding scheme is proved fo r various special cases. Index Terms—CEO problem,

Jun Chen; Toby Berger

2006-01-01

254

Cobalt source calibration  

SciTech Connect

The data obtained from these tests determine the dose rate of the two cobalt sources in SRTC. Building 774-A houses one of these sources while the other resides in room C-067 of Building 773-A. The data from this experiment shows the following: (1) The dose rate of the No.2 cobalt source in Building 774-A measured 1.073 x 10{sup 5} rad/h (June 17, 1999). The dose rate of the Shepherd Model 109 Gamma cobalt source in Building 773-A measured 9.27 x 10{sup 5} rad/h (June 25, 1999). These rates come from placing the graduated cylinder containing the dosimeter solution in the center of the irradiation chamber. (2) Two calibration tests in the 774-A source placed the graduated cylinder with the dosimeter solution approximately 1.5 inches off center in the axial direction. This movement of the sample reduced the measured dose rate 0.92% from 1.083 x 10{sup 5} rad/h to 1.073 x 10{sup 5} rad/h. and (3) A similar test in the cobalt source in 773-A placed the graduated cylinder approximately 2.0 inches off center in the axial direction. This change in position reduced the measured dose rate by 10.34% from 1.036 x 10{sup 6} to 9.27 x 10{sup 5}. This testing used chemical dosimetry to measure the dose rate of a radioactive source. In this method, one determines the dose by the chemical change that takes place in the dosimeter. For this calibration experiment, the author used a Fricke (ferrous ammonium sulfate) dosimeter. This solution works well for dose rates to 10{sup 7} rad/h. During irradiation of the Fricke dosimeter solution the Fe{sup 2+} ions ionize to Fe{sup 3+}. When this occurs, the solution acquires a slightly darker tint (not visible to the human eye). To determine the magnitude of the change in Fe ions, one places the solution in an UV-VIS Spectrophotometer. The UV-VIS Spectrophotometer measures the absorbency of the solution. Dividing the absorbency by the total time (in minutes) of exposure yields the dose rate.

Rizvi, H.M.

1999-12-03

255

Opportunities for High Aspect Ratio Micro-Electro-Magnetic-Mechanical Systems (HAR-MEMMS) at Lawrence Berkeley Laboratory  

NASA Astrophysics Data System (ADS)

This report contains viewgraphs on the following topics: Opportunities for HAR-MEMMS at LBL; Industrial Needs and Opportunities; Deep Etch X-ray Lithography; MEMS Activities at BSAC; DNA Amplification with Microfabricated Reaction Chamber; Electrochemistry Research at LBL; MEMS Activities at LLNL; Space Microsensors and Microinstruments; The Advanced Light Source; Institute for Micromaching; IBM MEMS Interests; and Technology Transfer Opportunities at LBL.

Hunter, Steven

1993-10-01

256

Opportunities for high aspect ratio micro-electro-magnetic-mechanical systems (HAR-MEMMS) at Lawrence Berkeley Laboratory  

SciTech Connect

This report contains viewgraphs on the following topics: Opportunities for HAR-MEMMS at LBL; Industrial Needs and Opportunities; Deep Etch X-ray Lithography; MEMS Activities at BSAC; DNA Amplification with Microfabricated Reaction Chamber; Electrochemistry Research at LBL; MEMS Activities at LLNL; Space Microsensors and Microinstruments; The Advanced Light Source; Institute for Micromaching; IBM MEMS Interests; and Technology Transfer Opportunities at LBL.

Hunter, S. [ed.

1993-10-01

257

Analysis of magnetron ion sources and PIG ion sources  

Microsoft Academic Search

Magnetron ion sources and PIG ion sources are sources of intense negative ion beams and multiply-charged positive and negative ion beams. They are composed of two electrodes, a sheath and a plasma. The author has classified them into magnetron (MG), inverse magnetron (IM), planar magnetron and Penning ionization gauge (PIG) ion sources. The PIG includes usual PIG, duoPIGatron and ANIS.

Noboru Tanizuka

1989-01-01

258

Understanding Slat Noise Sources  

NASA Technical Reports Server (NTRS)

Model-scale aeroacoustic tests of large civil transports point to the leading-edge slat as a dominant high-lift noise source in the low- to mid-frequencies during aircraft approach and landing. Using generic multi-element high-lift models, complementary experimental and numerical tests were carefully planned and executed at NASA in order to isolate slat noise sources and the underlying noise generation mechanisms. In this paper, a brief overview of the supporting computational effort undertaken at NASA Langley Research Center, is provided. Both tonal and broadband aspects of slat noise are discussed. Recent gains in predicting a slat s far-field acoustic noise, current shortcomings of numerical simulations, and other remaining open issues, are presented. Finally, an example of the ever-expanding role of computational simulations in noise reduction studies also is given.

Khorrami, Medhi R.

2003-01-01

259

Alternative energy sources  

NASA Astrophysics Data System (ADS)

Renewable energy sources and their potential contribution for solving energy needs are presented. Centralized supply technologies include those alternative fuels derived from biomass using solar energy, (supplying 57% of the energy supply in some countries), and those using directly collected solar energy to manufacture a fuel. Fuel utilization effects can be doubled by using combined heat and power stations, and other major sources include wind, wave, tidal, and solar. In terms of local supply technology, wood burning appliances are becoming more popular, and methane is being used for heating and to fuel spark ignition engines. Geothermal low temperature heating exists worldwide at a capacity of 7.2 GW, supplying heat, particularly in Hungary, parts of the U.S.S.R., and Iceland, and a geothermal research program has been established in the United States. Sweden has a potential hydroelectric capacity of 600 MW, and the United States has a 100 GW capacity. Many of these technologies are already cost effective.

Todd, R. W.

1982-04-01

260

Calibrated vapor generator source  

DOEpatents

A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet.

Davies, John P. (Idaho Falls, ID); Larson, Ronald A. (Idaho Falls, ID); Goodrich, Lorenzo D. (Shelley, ID); Hall, Harold J. (Idaho Falls, ID); Stoddard, Billy D. (Idaho Falls, ID); Davis, Sean G. (Idaho Falls, ID); Kaser, Timothy G. (Idaho Falls, ID); Conrad, Frank J. (Albuquerque, NM)

1995-01-01

261

Calibrated vapor generator source  

DOEpatents

A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet. 10 figs.

Davies, J.P.; Larson, R.A.; Goodrich, L.D.; Hall, H.J.; Stoddard, B.D.; Davis, S.G.; Kaser, T.G.; Conrad, F.J.

1995-09-26

262

Evaluated teletherapy source library  

DOEpatents

The Evaluated Teletherapy Source Library (ETSL) is a system of hardware and software that provides for maintenance of a library of useful phase space descriptions (PSDs) of teletherapy sources used in radiation therapy for cancer treatment. The PSDs are designed to be used by PEREGRINE, the all-particle Monte Carlo dose calculation system. ETSL also stores other relevant information such as monitor unit factors (MUFs) for use with the PSDs, results of PEREGRINE calculations using the PSDs, clinical calibration measurements, and geometry descriptions sufficient for calculational purposes. Not all of this information is directly needed by PEREGRINE. It also is capable of acting as a repository for the Monte Carlo simulation history files from which the generic PSDs are derived.

Cox, Lawrence J. (Los Alamos, NM); Schach Von Wittenau, Alexis E. (Livermore, CA)

2000-01-01

263

Marine petroleum source rocks  

SciTech Connect

Marine petroleum source rocks are of interest not only to petroleum geologists and geochemists but also to sedimentologists, stratigraphers and many oceanographers. This book is a collection of papers which were presented at a meeting held at the Royal Society, London, which was organized by the Petroleum Geochemistry and Marine Studies Groups of the Geological Society of London, with support from the Petroleum Exploration Society of Great Britain and various oil companies. The aim of the meeting was to bring together acknowledged experts and active workers from all the various disciplines that study marine petroleum source rocks and organic-rich marine sediments. General principles, depositional environments, especially important geographical areas and critical periods of the geological record were considered.

Brooks, J.; Fleet, A.

1986-01-01

264

Filtered cathodic arc source  

DOEpatents

A continuous, cathodic arc ion source coupled to a macro-particle filter capable of separation or elimination of macro-particles from the ion flux produced by cathodic arc discharge is described. The ion source employs an axial magnetic field on a cathode (target) having tapered sides to confine the arc, thereby providing high target material utilization. A bent magnetic field is used to guide the metal ions from the target to the part to be coated. The macro-particle filter consists of two straight solenoids, end to end, but placed at 45[degree] to one another, which prevents line-of-sight from the arc spot on the target to the parts to be coated, yet provides a path for ions and electrons to flow, and includes a series of baffles for trapping the macro-particles. 3 figures.

Falabella, S.; Sanders, D.M.

1994-01-18

265

Intense fusion neutron sources  

Microsoft Academic Search

The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 1015-1021 neutrons\\/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion

B. V. Kuteev; P. R. Goncharov; V. Yu. Sergeev; V. I. Khripunov

2010-01-01

266

THz Sources for Space  

NASA Technical Reports Server (NTRS)

Terahertz is the primary frequency for line and continuum radiation from cool (5-100K) gas (atoms and molecules) and dust. This viewgraph presentation reviews the reasons for the interest in Terahertz Space Applications; the Terahertz Space Missions: in the past, present and planned for the future, Terahertz source requirements and examples of some JPL instruments; and a case study for a flight deliverable: THz Local Oscillators for ESA s Herschel Space Telescope

Siegel, Peter H.; Ward, John; Maiwald, Frank; Mehdi, Imran

2007-01-01

267

Spallation-neutron sources  

SciTech Connect

Of particular interest for neutron-physics studies are spallation-neutron sources (SNSs) using intense proton beams with energies in the GeV range. Some SNSs already provide average fluxes of thermal and cold neutrons comparable with those of high-flux reactors. Most SNSs are pulsed with high peak fluxes that can be used with the powerful time-of-flight (TOF) method. Also, SNSs could be developed to much higher performance.

Michaudon, A.

1997-09-01

268

Intense fusion neutron sources  

Microsoft Academic Search

The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects\\u000a of creating fission and fusion neutron sources with intensities of 1015–1021 neutrons\\/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes\\u000a and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of\\u000a fusion

B. V. Kuteev; P. R. Goncharov; V. Yu. Sergeev; V. I. Khripunov

2010-01-01

269

Nonambipolar electron source  

SciTech Connect

A radio frequency (rf) plasma-based electron source that does not rely on electron emission at a cathode surface has been constructed. All of the random electron flux incident on an exit aperture is extracted through an electron sheath resulting in total nonambipolar flow within the device when the ratio of the ion loss area to the electron loss area is approximately equal to the square root of the ratio of the ion mass to the electron mass, and the ion sheath potential drop at the chamber walls is much larger than T{sub e}/e. The nonambipolar electron source (NES) has an axisymmetric magnetic field of 100 G at the extraction aperture that results in a uniform plasma potential across the aperture, allowing the extraction of all the incident electron flux without the use of grids. A prototype NES has produced 15 A of continuous electron current, using 15 SCCM (SCCM denotes cubic centimeter per minute at STP) Ar, 1200 W rf power at 13.56 MHz, and 6 times gas utilization. Alternatively 8 A of electron current can be produced, using 3 SCCM Ar at 1200 W rf and 20 times gas utilization. NES could replace hollow cathode electron sources in a wide variety of applications.

Longmier, B.; Baalrud, S.; Hershkowitz, N. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2006-11-15

270

Calibration Sources for CRIRES  

NASA Astrophysics Data System (ADS)

We report on our efforts to provide high accuracy wavelength calibration to the scientific observations with the Cryogenic High-Resolution IR Echelle Spectrograph (CRIRES), ESO's new high resolution (R?100,000) infrared (IR) spectrograph at the VLT. In order to provide reliable and accurate wavelength standards for CRIRES the European Southern Observatory (ESO), in collaboration with the Space Telescope European Co-ordinating Facility (ST-ECF) and the National Institute of Standards and Technology (NIST), embarked on a project to establish Th-Ar wavelength standards in the 950nm to 5000nm operating range of CRIRES. Based on current findings we conclude that Th-Ar hollow cathode lamps hold the promise of becoming a standard source for wavelength calibration for near IR astronomy, providing a high density of sharp well-characterized emission lines with the ease and efficiency of operation of a commercial discharge lamp. In addition, and for use at wavelengths larger than 2200, we have established a gas cell filled with N2O as a calibration source based on existing data from NIST. Both sources were extensively tested during CRIRES commissioning runs and both are now being used for routine operations of the instrument.

Kerber, F.; Seifahrt, A.; Bristow, P.; Nave, G.; Käufl, H. U.; Rosa, M. R.; Sansonetti, C. J.; Siebenmorgen, R.; Smette, A.

271

Negative ion source  

DOEpatents

A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cycloidal path, the electron velocity is reduced below its initial value. The electron accelerates as it leaves the surface at a rate of only slightly less than if there were no magnetic field, thereby preventing a charge buildup at the surface of the emitter. As the electron traverses the cycloid, it is decelerated during the second, third, and fourth quadrants, then reeccelerated as it approaches the end of the fourth quadrant to regain its original velocity. The minimum velocity occurs during the fourth quadrant, and corresponds to an electron temperature of 200.degree. to 500.degree. for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers. An ion source using the above-described thermalized electrons is also disclosed.

Delmore, James E. (Idaho Falls, ID)

1987-01-01

272

Plasmatic ion source  

NASA Astrophysics Data System (ADS)

A plasmatic ion source was built in which the hollow cathode above the two discharge chamber cathodes is readily replaced upon depletion after 250 to 300 h. The emission outlet hole is restored to original size by replacement of the cathode insert, while gas is continuously admitted by means of a spring mechanism. The source operates in the Penning discharge mode, with argon as the working gas. The hollow cathode is 36 mm long and has an inside diameter of 4 mm. The other two cathodes serve as pole shoes of a toroidal ferrite magnet which produces a longitudinal magnet field of 0.1 T induction in the discharge chamber. All three cathodes are made of magnetic steel and are insulated from cylindrical copper anode by teflon spacers. Heat is dissipated by oil, which carries it away to a water cooled housing compartment. The source generates an ion emission current of 20 mA with a discharge current of 200 mA at a pull voltage of 20kV.

Semenov, A. P.

1986-02-01

273

A useful infrared source.  

PubMed

Reliable Inconel-sheathed cartridge heaters rated at hundreds or thousands of watts have been in use for many years. Miniature heaters have been manufactured, having axial leads, which when treated with an emissive coating meet or exceed Globar emissivities in the ir. Free-air temperatures approximating 800 degrees C have been obtained for power inputs of 10 W, while temperatures as high as 1150 degrees C are possible for short lifetimes, e.g., 10 h, at power dissipations of 24 W or more. Sources can be designed to operate from d or ac power with higher voltages and lower currents depending upon physical size limitations, resulting in simplified power supply problems. Although voltages from 12 V to 230 V are practical for larger units, the sources described below operated at 1060 degrees C from a nominal 1.07 A at 18.7 V d for apower consumption of 20 W variable continuously about this value. The small dimensions of these sources compare favorably to those of a 0.5-W electronic resistor. The present units are cylindrical, 1 cm long x 4 mm diam. The construction of smaller units is possible bt difficult under present state-of-the-art limitations. PMID:20057526

Carlon, H R

1966-08-01

274

Effects of acoustic sources  

NASA Astrophysics Data System (ADS)

An experiment was conducted to determine the effect of acoustics on the laminar flow on the side of a nacelle. A flight test was designed to meet this goal and a brief review of the purpose is given. A nacelle with a significant length of laminar flow was mounted on the wing of NASA OV-1. Two noise sources are also mounted on the wing: one in the center body of the nacelle; the second in a wing mounted pod outboard of the nacelle. These two noise sources allow for a limited study of the effect of source direction in addition to control of the acoustic level and frequency. To determine the range of Tollmien-Schlichting frequencies, a stability analysis using the pressure coefficient distribution along the side of the nacelle was performed. Then by applying these frequencies and varying the acoustic level, a study of the receptivity of the boundary layer to the acoustic signal, as determined by the shortening of the length of laminar flow, was conducted. Results are briefly discussed.

Schoenster, James A.; Jones, Michael G.

1987-12-01

275

Improved negative ion source  

DOEpatents

A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cycloidal path, the electron velocity is reduced below its initial value. The electron accelerates as it leaves the surface at a rate of only slightly less than if there were no magnetic field, thereby preventing a charge buildup at the surface of the emitter. As the electron traverses the cycloid, it is decelerated during the second, third, and fourth quadrants, then reaccelerated as it approaches the end of the fourth quadrant to regain its original velocity. The minimum velocity occurs during the fourth quadrant, and corresponds to an electron temperature of 200 to 500/sup 0/C for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers. An ion source using the above-described thermalized electrons is also disclosed.

Delmore, J.E.

1984-05-01

276

Seismic source parameters  

SciTech Connect

The use of information contained on seismograms to infer the properties of an explosion source presents an interesting challenge because the seismic waves recorded on the seismograms represent only small indirect, effects of the explosion. The essential physics of the problem includes the process by which these elastic waves are generated by the explosion and also the process involved in propagating the seismic waves from the source region to the sites where the seismic data are collected. Interpretation of the seismic data in terms of source properties requires that the effects of these generation and propagation processes be taken into account. The propagation process involves linear mechanics and a variety of standard seismological methods have been developed for handling this part of the problem. The generation process presents a more difficult problem, as it involves non-linear mechanics, but semi-empirical methods have been developed for handling this part of the problem which appear to yield reasonable results. These basic properties of the seismic method are illustrated with some of the results from the NPE.

Johnson, L.R.

1994-06-01

277

Source Monitoring in Alzheimer's Disease  

ERIC Educational Resources Information Center

Source monitoring is the process of making judgments about the origin of memories. There are three categories of source monitoring: reality monitoring (discrimination between self- versus other-generated sources), external monitoring (discrimination between several external sources), and internal monitoring (discrimination between two types of…

El Haj, Mohamad; Fasotti, Luciano; Allain, Philippe

2012-01-01

278

NON-POINT SOURCE POLLUTION  

EPA Science Inventory

Non-point source pollution is a diffuse source that is difficult to measure and is highly variable due to different rain patterns and other climatic conditions. In many areas, however, non-point source pollution is the greatest source of water quality degradation. Presently, stat...

279

Accurate positions of OH sources  

NASA Technical Reports Server (NTRS)

The Owens Valley interferometer was used at 1665, 1667, and 1720 MHz to measure the positions of eleven OH emission sources. The 1720-MHz OH source in W3 (continuum) was found to be 40 seconds away from the H2O maser source and was found not to coincide with any radio or infrared feature. Two OH emission sources were found in NGC 7538; one is identifiable with a very compact radio infrared source, while the other, 80 seconds to the south, is as yet unidentified. The OH sources 0739-14 and Sharpless 269 also coincide with infrared sources.

Wynn-Williams, C. G.; Werner, M. W.; Wilson, W. J.

1974-01-01

280

H sup minus ion sources  

SciTech Connect

A review is given of H{sup {minus}} ion sources, with the emphasis on sources of use for accelerator applications. A brief description is given of magnetron, multicusp/converter, Penning and volume H{sup {minus}} ion sources. Operating parameters for examples of the various type sources are presented, and then some comparisons among the sources are made. 37 refs., 1 fig., 3 tabs.

Alessi, J.G.

1991-01-01

281

Cryogenic blackbody radiation calibration source  

NASA Technical Reports Server (NTRS)

A cryogenic blackbody radiation source for providing target temperatures between room temperature and -100 C was designed, fabricated, and tested. This blackbody radiation source is intended for calibration of radiometric infrared imaging systems down to -100 C. The construction and operating principles of this apparatus are described. The long term and short term stability of the radiant source have been investigated. The emittance of the source and the source radiant uniformity have been addressed.

Burkett, Cecil G., Jr.; Daryabeigi, Kamran

1992-01-01

282

BERNAS ION SOURCE DISCHARGE SIMULATION  

SciTech Connect

The joint research and development program is continued to develop steady-state ion source of decaborane beam for ion implantation industry. Bemas ion source is the wide used ion source for ion implantation industry. The new simulation code was developed for the Bemas ion source discharge simulation. We present first results of the simulation for several materials interested in semiconductors. As well the comparison of results obtained with experimental data obtained at the ITEP ion source test-bench is presented.

RUDSKOY,I.; KULEVOY, T.V.; PETRENKO, S.V.; KUIBEDA, R.P.; SELEZNEV, D.N.; PERSHIN, V.I.; HERSHCOVITCH, A.; JOHNSON, B.M.; GUSHENETS, V.I.; OKS, E.M.; POOLE, H.J.

2007-08-26

283

The BEM for point heat source estimation: application to multiple static sources and moving sources  

Microsoft Academic Search

This paper deals with an inverse problem, which consists of the identification of point heat sources in a homogeneous solid in transient heat conduction. The location and strength of the line heat sources are both unknown. For a single source we examine the case of a source which moves in the system during the experiment. The two-dimensional and three-dimensional linear

Frédéric Lefèvre; Christophe Le Niliot

2002-01-01

284

The Combustive Sound Source  

NASA Astrophysics Data System (ADS)

This thesis describes a unique type of low frequency underwater sound source, the Combustive Sound Source (CSS). The fundamental operating principle of CSS is the following: Electrolysis of water produces hydrogen and oxygen gas, which is a combustible mixture. The gas mixture is captured in a combustion chamber and ignited with a spark. The ensuing combustion produces expanding gases which in turn produce high intensity, low frequency acoustic pulses. The thesis begins by discussing the background of the project and initial feasibility work. It continues by briefly discussing electrolysis and gas production. Fundamental combustion theory is discussed, along with two experiments that relate the acoustic output of CSS to theory. Additional experiments were conducted in order to compare the first bubble period in the CSS pressure signature with the predictions of the Rayleigh-Willis equation. The dependence of the radiated acoustic waveform on the volume and depth of the bubble was investigated. The first bubble period of the CSS pressure signature agrees with Rayleigh-Willis theory in trend, but not in absolute value. Empirical equations are presented which predict the first bubble period for three different situations, a depth of nine meters for various stoichiometric volumes, a stoichiometric volume of 0.5 STP liters for various depths, and a stoichiometric volume of 500 cubic centimeters for various depths. High speed filming of the CSS bubble is presented. The high speed films confirm that CSS produces a bubble of high temperature combustion products. The bubble oscillates and generates acoustic output. The motion of the bubble is shown to be related to the acoustic output in the classic manner, with pressure peaks associated with minimum bubble volumes. Finally, several other factors that affect the acoustic output of CSS are discussed. These include the shape of the CSS combustion chamber, the ignition source, the oxidizer, the presence of high pressure bubble collapses, and the presence of high frequency components.

Wilson, Preston S.

1994-04-01

285

Integrated Power Source Grant  

NASA Technical Reports Server (NTRS)

Traditional spacecraft power systems incorporate a solar array energy source, an energy storage element (battery), and battery charge control and bus voltage regulation electronics to provide continuous electrical power for spacecraft systems and instruments. Dedicated power conditioning components provide limited fault isolation between systems and instruments, while a centralized power-switching unit provides spacecraft load control. Battery undervoltage conditions are detected by the spacecraft processor, which removes fault conditions and non-critical loads before permanent battery damage can occur. Cost effective operation of a micro-sat constellation requires a fault tolerant spacecraft architecture that minimizes on-orbit operational costs by permitting autonomous reconfiguration in response to unexpected fault conditions. A new micro-sat power system architecture that enhances spacecraft fault tolerance and improves power system survivability by continuously managing the battery charge and discharge processes on a cell-by-cell basis has been developed. This architecture is based on the Integrated Power Source (US patent 5644207), which integrates dual junction solar cells, Lithium Ion battery cells, and processor based charge control electronics into a structural panel that can be deployed or used to form a portion of the outer shell of a micro-spacecraft. The first generation Integrated Power Source is configured as a one inch thick panel in which prismatic Lithium Ion battery cells are arranged in a 3x7 matrix (26VDC) and a 3x1 matrix (3.7VDC) to provide the required output voltages and load currents. A multi-layer structure holds the battery cells, as well as the thermal insulators that are necessary to protect the Lithium Ion battery cells from the extreme temperatures of the solar cell layer. Independent thermal radiators, located on the back of the panel, are dedicated to the solar cell array, the electronics, and the battery cell array. In deployed panel applications, these radiators maintain the battery cells in an appropriate operational temperature range.

2001-01-01

286

Sources of tritium  

SciTech Connect

A review of tritium sources is presented. The tritium production and release rates are discussed for light water reactors (LWRs), heavy water reactors (HWRs), high temperature gas cooled reactors (HTGRs), liquid metal fast breeder reactors (LMFBRs), and molten salt breeder reactors (MSBRs). In addition, release rates are discussed for tritium production facilities, fuel reprocessing plants, weapons detonations, and fusion reactors. A discussion of the chemical form of the release is included. The energy producing facilities are ranked in order of increasing tritium production and release. The ranking is: HTGRs, LWRs, LMFBRs, MSBRs, and HWRs. The majority of tritium has been released in the form of tritiated water.

Phillips, J.E.; Easterly, C.E.

1980-12-01

287

Sources Sought Notice  

Cancer.gov

This is an 8(a) Small Business Sources Sought (SBSS) Notice. This is NOT a solicitation for proposals, proposal abstracts, or quotations. The purpose of this notice is to obtain information regarding the availability and capability of qualified 8(a) small businesses under the size classification relative to the North American Industry Classification System (NAICS) code for the proposed acquisition. Your responses to the information requested will assist the Government in determining the appropriate acquisition method, including whether a set-aside is possible.

288

Ion beam source  

SciTech Connect

An ion beam source characterized in that a needle-like tip is comprised of a carbide, a nitride, or a diboride of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, and Ta, a hexaboride of at least one element of rare earth metal elements of atomic numbers 57-70, or carbon. Stable ion beam emission of high brightness and long life can be obtained by using the needle-like tip of the said material.

Futamoto, M.; Kawabe, U.; Yuito, I.

1984-08-21

289

Advanced Photon Source  

NSDL National Science Digital Library

Synchrotrons are used to study the atomic structure of materials. The second largest synchrotron is the Advanced Photon Source, located at the Argonne National Laboratory in Argonne, Illinois. The homepage provides information on the synchrotron and current research being conducted at the laboratory. This site covers one of the top ten scientific breakthroughs of 1997, compiled in the December 19, 1997 issue of Science. The top scientific breakthrough of 1997 was the cloning of a sheep, resulting in a lamb named Dolly. The nine runners up were: the Pathfinder mission to Mars, synchrotrons, biological clock genes, gamma ray bursts, Neandertal DNA, nanotubes, Europa's ocean, whole genome sequencing, and neurons.

1998-01-01

290

Point radiographic source characterization  

SciTech Connect

A study was undertaken to find the optimal conditions for generating x rays using a high-power frequency-doubled Nd laser pulse for x-ray backlighting application. More than 30 laser shots on the Lawrence Livermore National Laboratory JANUS Research Laser system have been studied. The following specific questions are addressed: (a) X-ray yield dependence on the laser parameters: (i) temporal pulse width and (ii) focusing conditions. (b) X-ray source size versus target dimensions by using a tungsten wire with various diameters. (c) Influence of background plasma on the x-ray yield from the wire using 25- m wires surrounded by plastic.

Zigler, A.; Lee, R.W.; Kilkenny, J.D.; Kolbe, G.; Nathel, H.

1987-09-01

291

LLSDC Legislative Source Book  

NSDL National Science Digital Library

The Law Librarians' Society of Washington, D.C. recently announced that they have placed online a series of unique informational documents and links of interest to law librarians and government researchers. Compiled by LLSDC's Legislative Research Special Interest Section, much of the material was previously available in print, but is gathered together online for the first time. Titles include Establishing Persistent Links to Thomas and GPO Access Documents, GPO Congressional Publication Releases (weekly listings), Internet and Online Sources of Legislative and Regulatory Information, Quick Links to House and Senate Committee Documents and Hearings, and the Union List of Legislative Documents, 1994, 3rd. edition.

292

New Developments with H- Sources  

SciTech Connect

Existing spallation neutron source upgrades, planned spallation neutron sources, and high-energy accelerators for particle physics place demanding requirements on the H- sources. These requirements ask for increased beam currents and duty factor (df) while generally maintaining state-of-the art H- source emittance. A variety of H- sources are being developed to address these challenges. These include volume sources with and without the addition of cesium for enhanced H- production, increased df cesiated H- Penning and magnetron sources, and cesiated surface converter H- sources. Research on surface films of tantalum metal for enhanced volume H- production is also being studied. Innovative plasma production techniques to address the longer df requirement without sacrificing H- source reliability and lifetime will be reviewed. The physical bases, the goals, and perceived challenges will be discussed.

Sherman, Joseph D.; Rouleau, Gary [Los Alamos National Laboratory, Los Alamos, NM87545 (United States)

2003-08-26

293

Modeling Magnetospheric Sources  

NASA Technical Reports Server (NTRS)

We have used global magnetohydrodynamic, simulations of the interaction between the solar wind and magnetosphere together with single particle trajectory calculations to investigate the sources of plasma entering the magnetosphere. In all of our calculations solar wind plasma primarily enters the magnetosphere when the field line on which it is convecting reconnects. When the interplanetary magnetic field has a northward component the reconnection is in the polar cusp region. In the simulations plasma in the low latitude boundary layer (LLBL) can be on either open or closed field lines. Open field lines occur when the high latitude reconnection occurs in only one cusp. In the MHD calculations the ionosphere does not contribute significantly to the LLBL for northward IMF. The particle trajectory calculations show that ions preferentially enter in the cusp region where they can be accelerated by non-adiabatic motion across the high latitude electric field. For southward IMF in the MHD simulations the plasma in the middle and inner magnetosphere comes from the inner (ionospheric) boundary of the simulation. Solar wind plasma on open field lines is confined to high latitudes and exits the tailward boundary of the simulation without reaching the plasma sheet. The LLBL is populated by both ionospheric and solar wind plasma. When the particle trajectories are included solar wind ions can enter the middle magnetosphere. We have used both the MHD simulations and the particle calculations to estimate source rates for the magnetosphere which are consistent with those inferred from observations.

Walker, Raymond J.; Ashour-Abdalla, Maha; Ogino, Tatsuki; Peroomian, Vahe; Richard, Robert L.

2001-01-01

294

Optimization of neutron source  

SciTech Connect

I consider here the optimization of the two component neutron source, allowing beam species and energy to vary. A simple model is developed, based on the earlier publications, that permits the optimum to be obtained simply. The two component plasma, with one species of hot ion (D{sup +} or T{sup +}) and the complementary species of cold ion, is easy to analyze in the case of a spatially uniform cold plasma, as to good approximation the total number of hot ions is important but not their spatial distribution. Consequently, the optimization can ignore spatial effects. The problem of a plasma with both types of hot ions and cold ions is rather more difficult, as the neutron production by hot-hot interactions is sensitive to their spatial distributions. Consequently, consideration of this problem will be delayed to a future memorandum. The basic model is that used in the published articles on the two-component, beam-plasma mirror source. I integrate the Fokker-Planck equation analytically, obtaining good agreement with previous numerical results. This simplifies the optimization, by providing a functional form for the neutron production. The primary result is expressed in terms of the power efficiency: watts of neutrons/watts of primary power. The latter includes the positive ion neutralization efficiency. At 150 keV, the present model obtains an efficiency of 0.66%, compared with 0.53% of the earlier calculation.

Hooper, E.B.

1993-11-09

295

DreiserWebSource  

NSDL National Science Digital Library

Designed and maintained by the Annenberg Rare Book and Manuscript Library Collection at the University of Pennsylvania, the DreiserWebSource website brings together a host of written ephemera, original essays, and electronic texts related to the life and writings of Theodore Dreiser, the prominent American author. While the site doesn't have a formal search engine, the material is divided into four primary sections: Correspondence & Texts, Scholarly Essays, Reference Sources, and Still and Moving images. The Correspondence & Texts section is a delight unto itself, as it contains a host of digitized correspondence between Dreiser and colleagues over several decades and a special section dedicated to his ground-breaking novel, Sister Carrie. Along with several editions of the complete novel there are several essays about the novel's composition and historical context, along with a virtual exhibition curated by Nancy M. Shawcross from the Rare Book & Manuscript Library at Penn. The site also includes a rare 3-minute silent film of Dreiser from 1938 at Mt. Kisco, New York, taken by Robert Elias.

296

Groklaw: Understanding Open Source Software  

NSDL National Science Digital Library

Mark Webbink, Red Hat's general counsel, wrote this article for attorneys wanting to know the basic issues regarding free and open source software. Aside from listing best practices for law offices, he provides a general overview of various open source licenses, explains US copyright law, defines derivative works, and touches on the indemnification issue and the difference between open source and shared source. Webbink also highlights some of the common myths and misconceptions about the General Public License (GPL) and open source and provides links to other sites with more information on open source software. Readers' comments and responses to the article are also posted in a threaded discussion format.

297

A Multimodal Approach to Blind Source Separation of Moving Sources  

Microsoft Academic Search

A novel multimodal approach is proposed to solve the problem of blind source separation (BSS) of moving sources. The challenge of BSS for moving sources is that the mixing filters are time varying; thus, the unmixing filters should also be time varying, which are difficult to calculate in real time. In the proposed approach, the visual modality is utilized to

Syed Mohsen Naqvi; Miao Yu; Jonathon A. Chambers

2010-01-01

298

AsiaSource  

NSDL National Science Digital Library

This site has been developed by the Asia Society (last discussed in the March 5, 1999 Scout Report) as a comprehensive source for news and resources on Asian culture, business, politics, and history. Researchers, students, and general users will find a wealth of useful information at this site, from breaking news stories to articles and speeches on a wide variety of topics (most are off site) to maps and statistics to special Asia Society features. Other resources include an event calendar, a glossary, related links, and a database of Asian specialists. Each segment of the major sections of the site also include a list of highlighted resources (event, book, view, and link) picked by Asia Society. Users can also subscribe for free email updates. Already a respected provider of authoritative information and analysis, the Asia Society establishes itself as one of the leading online resources for Asian Studies with this fine site.

299

Thulium-170 heat source  

DOEpatents

An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

Walter, Carl E. (Pleasanton, CA); Van Konynenburg, Richard (Livermore, CA); VanSant, James H. (Tracy, CA)

1992-01-01

300

Extragalactic radio sources  

NASA Technical Reports Server (NTRS)

The standard model for extragalactic variable radio sources comprises an isotropically expanding plasmoid with frozen magnetic flux and an electron distribution which evolves adiabatically. This model leads to the following relaton between the peak luminosity L (sub nu, m) and the relevant frequency nu(sub m) which are functions of time: L(sub nu,m) is proportional to nu(sub m)(n) where N = (7n + 5)/(4n + 5). In this expression, n is the spectral index in the optically thin part of the spectrum, where L (sub nu) is proportional to nu (-n). For n in the range 0.5 to 1.5, the standard model yields N in the range 1.2 to 1.4. By contrast, analysis of observational data yields estimates of N in a small range about the mean value 0.4, in clear contradiction with the standard model.

Sturrock, P. A.

1984-01-01

301

Arsenic pollution sources.  

PubMed

Arsenic is a widely dispersed element in the Earth's crust and exists at an average concentration of approximately 5 mg/kg. There are many possible routes of human exposure to arsenic from both natural and anthropogenic sources. Arsenic occurs as a constituent in more than 200 minerals, although it primarily exists as arsenopyrite and as a constituent in several other sulfide minerals. The introduction of arsenic into drinking water can occur as a result of its natural geological presence in local bedrock. Arsenic-containing bedrock formations of this sort are known in Bangladesh, West Bengal (India), and regions of China, and many cases of endemic contamination by arsenic with serious consequences to human health are known from these areas. Significant natural contamination of surface waters and soil can arise when arsenic-rich geothermal fluids come into contact with surface waters. When humans are implicated in causing or exacerbating arsenic pollution, the cause can almost always be traced to mining or mining-related activities. Arsenic exists in many oxidation states, with arsenic (III) and (V) being the most common forms. Similar to many metalloids, the prevalence of particular species of arsenic depends greatly on the pH and redox conditions of the matrix in which it exists. Speciation is also important in determining the toxicity of arsenic. Arsenic minerals exist in the environment principally as sulfides, oxides, and phosphates. In igneous rocks, only those of volcanic origin are implicated in high aqueous arsenic concentrations. Sedimentary rocks tend not to bear high arsenic loads, and common matrices such as sands and sandstones contain lower concentrations owing to the dominance of quartz and feldspars. Groundwater contamination by arsenic arises from sources of arsenopyrite, base metal sulfides, realgar and orpiment, arsenic-rich pyrite, and iron oxyhydroxide. Mechanisms by which arsenic is released from minerals are varied and are accounted for by many (bio)geochemical processes: oxidation of arsenic-bearing sulfides, desorption from oxides and hydroxides, reductive dissolution, evaporative concentration, leaching from sulfides by carbonate, and microbial mobilization. Arsenic enrichment also takes place in geothermally active areas; surface waters are more susceptible than groundwater to contamination in the vicinity of such geothermal systems, and evidence suggests that increased use of geothermal power may elevate risks of arsenic exposure in affected areas. Past and current mining activities continue to provide sources of environmental contamination by arsenic. Because gold- and arsenic-bearing minerals coexist, there is a hazard of mobilizing arsenic during gold mining activities. The Ashanti region of central Ghana currently faces this as a real risk. Historical arsenic contamination exists in Cornwall, UK; an example of a recent arsenic pollution event is that of Ron Phibun town in southern Thailand, where arsenic-related human health effects have been reported. Other important sources of arsenic exposure include coal burning in Slovakia, Turkey, and the Guizhou Province of China; use of arsenic as pesticides in Australia, New Zealand, and the US; and consumption of contaminated foodstuffs (China) and exposure to wood preserving arsenicals (Europe and North America). PMID:18982996

Garelick, Hemda; Jones, Huw; Dybowska, Agnieszka; Valsami-Jones, Eugenia

2008-01-01

302

Migration Information Source  

NSDL National Science Digital Library

As a publication of the Migration Policy Institute, the Migration Information Source "provides fresh thought, authoritative data from numerous global organizations and governments, and global analysis of international migration and refugee trends." Their well-organized homepage offers policy briefs, "Spotlight" features (including a recent one on Indian immigrants in the United States), and information about their ongoing projects. Policy makers and scholars will love the "Immigration Data Hub" area. Here they can get valuable data on state responses to immigrations, the top global destinations for Irish immigrants, as well as historical immigration data. Visitors can also use the "US in Focus" area to find out about specific immigration trends throughout the country, with a special focus on policy issues affecting states and urban areas. The site is rounded out by an RSS feed, a press room of recent news releases, and a glossary of terms.

303

Spark source infrared fluorometry  

NASA Astrophysics Data System (ADS)

The application of our development of 750 nm excitation from an argon-hydrogen filled spark source to time-resolved fluorescence probe studies of lipid membranes and inverse micelles is reported. The laser dye IR-140 was studied using the single-photon counting technique both in a lipid membrane of L-(alpha) dipalmitoylphosphatidylcholine (DPPC) and in sodium sulfosuccinic acid bis (2-ethylhexyl) ester (AOT) in iso-octane. In DPPC a dramatic change in the fluorescence behavior of IR-140 is observed between the gel and liquid crystalline phases. In inverse micelles of AOT an increase in the intensity of the peak fluorescence emission and a decrease in fluorescence lifetime is noticed on increasing the water content.

Hungerford, Graham; Birch, David J.; Imhof, Robert E.

1992-04-01

304

Semiconductor surface plasmon sources.  

PubMed

Surface-plasmon polaritons (SPPs) are propagating electromagnetic modes bound at a metal-dielectric interface. We report on electrical generation of SPPs by reproducing the analogue in the near field of the slit-doublet experiment, in a device which includes all the building blocks required for a fully integrated plasmonic active source: an electrical generator of SPPs, a coupler, and a passive metallic waveguide. SPPs are generated upon injection of electrical current, and they are then launched at the edges of a passive metallic strip. The interference fringes arising from the plasmonic standing wave on the surface of the metallic strip are unambiguously detected with apertureless near-field scanning optical microscopy. PMID:20867196

Babuty, A; Bousseksou, A; Tetienne, J-P; Doyen, I Moldovan; Sirtori, C; Beaudoin, G; Sagnes, I; De Wilde, Y; Colombelli, R

2010-06-01

305

Multiple source heat pump  

DOEpatents

A heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating a fluid in heat exchange relationship with a refrigerant fluid, at least three refrigerant heat exchangers, one for effecting heat exchange with the fluid, a second for effecting heat exchange with a heat exchange fluid, and a third for effecting heat exchange with ambient air; a compressor for compressing the refrigerant; at least one throttling valve connected at the inlet side of a heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circuit and pump for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and directional flow of refrigerant therethrough for selecting a particular mode of operation. Also disclosed are a variety of embodiments, modes of operation, and schematics therefor.

Ecker, Amir L. (Duncanville, TX)

1983-01-01

306

Large area plasma source  

NASA Technical Reports Server (NTRS)

An all permanent magnet Electron Cyclotron Resonance, large diameter (e.g., 40 cm) plasma source suitable for ion/plasma processing or electric propulsion, is capable of producing uniform ion current densities at its exit plane at very low power (e.g., below 200 W), and is electrodeless to avoid sputtering or contamination issues. Microwave input power is efficiently coupled with an ionizing gas without using a dielectric microwave window and without developing a throat plasma by providing a ferromagnetic cylindrical chamber wall with a conical end narrowing to an axial entrance hole for microwaves supplied on-axis from an open-ended waveguide. Permanent magnet rings are attached inside the wall with alternating polarities against the wall. An entrance magnet ring surrounding the entrance hole has a ferromagnetic pole piece that extends into the chamber from the entrance hole to a continuing second face that extends radially across an inner pole of the entrance magnet ring.

Foster, John (Inventor); Patterson, Michael (Inventor)

2008-01-01

307

High brightness electron sources  

SciTech Connect

High energy physics accelerators and free electron lasers put increased demands on the electron beam sources. This paper describes the present research on attaining intense bright electron beams using photoinjectors. Recent results from the experimental programs will be given. The performance advantages and difficulties presently faced by researchers will be discussed, and the following topics will be covered. Progress has been made in photocathode materials, both in lifetime and quantum efficiency. Cesium telluride has demonstrated significantly longer lifetimes than cesium antimonide at 10{sup {minus}8} torr. However, the laser system is more difficult because cesium telluride requires quadrupled YLF instead of the doubled YLF required for cesium antimonide. The difficulty in using photoinjectors is primarily the drive laser, in particular the amplitude stability. Finally, emittance measurements of photoinjector systems can be complicated by the non-thermal nature of the electron beam. An example of the difficulty in measuring beam emittance is given.

Sheffield, R.L.

1995-07-01

308

Medicaid Data Sources - General Information  

MedlinePLUS

... Datamart MAX Validation Reports Medicaid Data Sources - General Information The primary data sources for Medicaid statistical data are the Medicaid Statistical Information System (MSIS), the Medicaid Analytic eXtract (MAX) files, ...

309

Methane Emissions from Industrial Sources.  

National Technical Information Service (NTIS)

This chapter identifies and describes major industrial sources of methane (CH4) emissions. For each source type examined, CH4 release points are identified and a detailed discussion of the factors affecting emissions is provided. A summary and discussion ...

L. L. Beck S. D. Piccot D. A. Kirchgessner

1993-01-01

310

Optical Power Source Control System.  

National Technical Information Service (NTIS)

An optical power source control system having a four port optical coupler, an optical receiver and associated comparator circuits operably connected to the optical transmission line connecting the source to an output connector. When the output connector i...

C. R. Husbands

1981-01-01

311

EEG/MEG source localization using source deflated matching pursuit.  

PubMed

A matching pursuit (MP) based algorithm, called source deflated matching pursuit (SDMP), is proposed for locating sources of brain activity. By iteratively deflating the contribution of identified sources to multiple measurement vectors (MMVs), the SDMP algorithm transforms the original multi-basis-vector/matrix selection problem into a single-basis-vector/matrix selection problem, which not only mitigates the residual-source interference but also remedies the intrinsic bias when locating deep sources. The robustness of the proposed algorithm to two bias factors is verified through simulations. PMID:22255845

Wu, Shun Chi; Swindlehurst, A Lee

2011-01-01

312

Off line ion source terminal  

NASA Astrophysics Data System (ADS)

The off-line ion source (OLIS) terminal provides beams from stable isotopes to ISAC (see Fig. 1) experiments as well as for accelerator commissioning and for pilot beams for radioactive beam experiments. The OLIS terminal (see Fig. 2) is equipped with a microwave driven cusp source for single and double charge ions, a surface ion source for low energy spread alkali beams, and a multi-charge ion source.

Jayamanna, K.

2014-01-01

313

Ion source development at GSI  

Microsoft Academic Search

Different ion sources are used at GSI to match the requirements for specific tasks at the accelerator. At the standard injector a Penning ionization gauge ion source is used (design ion U10+, m\\/q<24, 1 emA). Further development of this source is mainly aiming at an increase of the extractable currents and an increase of the lifetime of the source. The

P. Spädtke; J. Bossler; H. Emig; K. D. Leible; C. Mühle; H. Reich; H. Schulte; K. Tinschert

1998-01-01

314

Bayesian source separation for cosmology  

Microsoft Academic Search

Recent satellite missions have provided and continue to provide us with vast amounts of data on radiation measurements that generally present themselves as superpositions of various cosmological sources, most importantly cosmic microwave background (CMB) radiation and other galactic and extragalactic sources. We would like to obtain the estimates of these sources separately since they carry vital information of cosmological significance

Ercan E. Kuruoglu

2010-01-01

315

Sourcing strategies of facilities management  

Microsoft Academic Search

In this study, four sourcing strategies are identified in the delivery of maintenance service in facilities management, namely in-sourcing, out-tasking, outsourcing for cost saving, and outsourcing for capability. Since each of these strategies has merits under specific circumstances, a framework for the selection of appropriate sourcing strategy in particular situations is presented. This framework, which takes into consideration both the

Encon Y. Y. Hui; Albert H. C. Tsang

2004-01-01

316

The SLC polarized electron source  

SciTech Connect

A polarized electron source consisting of a 3-electrode photocathode gun and a flashlamp-pumped dye laser has been designed and built for the SLC and is currently undergoing commissioning. The source is described, and the operating configuration is discussed. The present status of the source and future plans are briefly indicated. 7 refs., 4 figs.

Clendenin, J.E.

1990-10-01

317

How Is Open Source Special?  

ERIC Educational Resources Information Center

Open source software projects involve the production of goods, but in software projects, the "goods" consist of information. The open source model is an alternative to the conventional centralized, command-and-control way in which things are usually made. In contrast, open source projects are genuinely decentralized and transparent. Transparent…

Kapor, Mitchell

2005-01-01

318

Ion sources for cyclotron applications  

SciTech Connect

The use of a multicusp plasma generator as an ion source has many advantages. The development of both positive and negative ion beams based on the multicusp source geometry is presented. It is shown that these sources can be operated at steady state or cw mode. As a result they are very suitable for cyclotron operations.

Leung, K.N.; Bachman, D.A.; McDonald, D.S.; Young, A.T.

1992-07-01

319

On Multiterminal Source Code Design  

Microsoft Academic Search

Multiterminal (MT) source coding refers to separate lossy encoding and joint decod- ing of multiple correlated sources. This paper presents two practical MT coding schemes under the same general framework of Slepian-Wolf coded quantization (SWCQ) for both direct and indirect quadratic Gaussian MT source coding problems with two encoders. The first asymmetric SWCQ scheme relies on quantization and Wyner-Ziv coding,

Yang Yang; Vladimir Stankovic; Zixiang Xiong; Wei Zhao

2005-01-01

320

Runlength codes from source codes  

Microsoft Academic Search

A class of binary runlength codes, also known as (d,k) codes, is analyzed. These codes are developed by constructing a lossless source code that maps runlengths into unconstrained binary sequences. The source code is constructed for the maxentropic distribution on runlengths. The inverse of the source code, which outputs runlengths guided toward the ideal maxentropic distribution, is the (d,k) code.

Kenneth J. Kerpez

1991-01-01

321

Chandra Source Catalog: User Interfaces  

NASA Astrophysics Data System (ADS)

The CSCview data mining interface is available for browsing the Chandra Source Catalog (CSC) and downloading tables of quality-assured source properties and data products. Once the desired source properties and search criteria are entered into the CSCview query form, the resulting source matches are returned in a table along with the values of the requested source properties for each source. (The catalog can be searched on any source property, not just position.) At this point, the table of search results may be saved to a text file, and the available data products for each source may be downloaded. CSCview save files are output in RDB-like and VOTable format. The available CSC data products include event files, spectra, lightcurves, and images, all of which are processed with the CIAO software. CSC data may also be accessed non-interactively with Unix command-line tools such as cURL and Wget, using ADQL 2.0 query syntax. In fact, CSCview features a separate ADQL query form for those who wish to specify this type of query within the GUI. Several interfaces are available for learning if a source is included in the catalog (in addition to CSCview): 1) the CSC interface to Sky in Google Earth shows the footprint of each Chandra observation on the sky, along with the CSC footprint for comparison (CSC source properties are also accessible when a source within a Chandra field-of-view is clicked); 2) the CSC Limiting Sensitivity online tool indicates if a source at an input celestial location was too faint for detection; 3) an IVOA Simple Cone Search interface locates all CSC sources within a specified radius of an R.A. and Dec.; and 4) the CSC-SDSS cross-match service returns the list of sources common to the CSC and SDSS, either all such sources or a subset based on search criteria.

Bonaventura, Nina; Evans, I. N.; Harbo, P. N.; Rots, A. H.; Tibbetts, M. S.; Van Stone, D. W.; Zografou, P.; Anderson, C. S.; Chen, J. C.; Davis, J. E.; Doe, S. M.; Evans, J. D.; Fabbiano, G.; Galle, E.; Gibbs, D. G.; Glotfelty, K. J.; Grier, J. D.; Hain, R.; Hall, D. M.; He, X.; Houck, J. C.; Karovska, M.; Lauer, J.; McCollough, M. L.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Nichols, J. S.; Nowak, M. A.; Plummer, D. A.; Primini, F. A.; Refsdal, B. L.; Siemiginowska, A. L.; Sundheim, B. A.; Winkelman, S. L.

2010-02-01

322

Radioactive source recovery program responses to neutron source emergencies  

SciTech Connect

Recovery of neutron sources containing Pu{sup 239} and Be is currently taking place at Los Alamos National Laboratory. The program was initiated in 1979 by the Department of Energy (DOE) to dismantle and recover sources owned primarily by universities and the Department of Defense. Since the inception of this program, Los Alamos has dismantled and recovered more than 1000 sources. The dismantlement and recovery process involves the removal of source cladding and the chemical separation of the source materials to eliminate neutron emissions. While this program continues for the disposal of {sup 239}Pu/Be sources, there is currently no avenue for the disposition of any sources other than those containing Pu{sup 239}. Increasingly, there have been demands from agencies both inside and outside the Federal Government and from the public to dispose of unwanted sources containing {sup 238}Pu/Be and {sup 241}Am/Be. DOE is attempting to establish a formal program to recover these sources and is working closely with the Nuclear Regulatory Commission (NRC) on a proposed Memorandum of Understanding to formalize an Acceptance Program. In the absence of a formal program to handle {sup 238}Pu/Be and {sup 241}Am/Be neutron sources, Los Alamos has responded to several emergency requests to receive and recover sources that have been determined to be a threat to public health and safety. This presentation will: (1) review the established {sup 239}Pu neutron source recovery program at Los Alamos, (2) detail plans for a more extensive neutron source disposal program, and (3) focus on recent emergency responses.

Dinehart, S.M.; Hatler, V.A.; Gray, D.W.; Guillen, A.D. [and others

1997-04-01

323

Thermovoltaic power source  

SciTech Connect

A thermophotovoltaic power source comprises a Cassegrain solar collector and concentrator, a thermal vessel including a containment vessel holding thermal storage material therein, the containment vessel having the shape of an annulus closed at one end and disposed with its open end in registry with an aperture in the thermal vessel, with a selective band radiating layer coating the internal surface of the annulus cavity, and further including an external array of photovoltaic cells mounted on a cooled cylinder disposed for insertion by a positioning motor to a desired depth into the annulus cavity and thus into adjacency with the selective band radiating layer. Concentrated solar energy is applied by the solar collector through a second aperture into the thermal vessel to heat the thermal storage material in the containment vessel and thereby cause the selective radiating layer to radiate energy to excite a current in the photovoltaic array. Constant current control and/or load-matching are obtained by varying the degree of insertion of the photovoltaic array into the thermal storage annular cavity.

Severns, J.G.

1982-06-30

324

LISA and Capture Sources  

NASA Astrophysics Data System (ADS)

LISA is a joint ESA/NASA mission to detect and observe gravitational waves. It is designed to register the change in distance between free-falling reference points to picometer accuracy, allowing to measure the effect of gravitational waves created by the coalescence of massive black holes almost anywhere in the universe, stellar mass black holes and neutron stars spiraling into massive black holes in other galaxies at intermediate distances, and tightly orbiting binary stars in our galaxy. LISA will be able to detect gravitational waves from coalescing massive black holes to redshifts of z ˜ 10 and higher, allowing an unprecedented view into the early stages of galaxy formation. The signals from the many million binary stars in our galaxy yield information about the evolution and the morphology of our galaxy, giving a view of the population of binary stars unobstructed by dust. Among the most challenging, yet scientifically interesting sources are the captures of a small massive object by massive black holes where the mass ratio exceeds 1,000. Those events, named extreme mass ratio inspirals (EMRI), create very complex waveforms and allow to test general relativity to very high precision. LISA has been recently confirmed as a candidate for the L1 mission in ESA's Cosmic Vision program and is foreseen to be launched in the 2018 time frame.

Jennrich, Oliver

325

Migration Information Source  

NSDL National Science Digital Library

Recently introduced by the Migration Policy Institute, the Migration Information Source Web site offers visitors a fantastic opportunity to stay on top of trends and changes in global migration. Looking at migration from many levels and on many planes, the site considers migrations on both national and international fronts. With a dropdown menu of the countries for which data is available (currently western European countries, Australia, and the US), the database is fully searchable, with more options on the way. Perhaps most interesting to those directly working in statistical, sociological, or ethnographic analyses of migration, the resource is broadly accessible and offers compelling glimpses of migrant populations, their reasons for moving, and their rates of assimilation into host countries. For those unfamiliar with field-specific terms employed in the site's reports, there is a detailed glossary of common terms and phrases. Closer to home, the Migration Information site presents an elaborate array of reports and studies on US-Mexico relations, with an emphasis on the ever-broadening trend toward northward migration in the Americas.

2002-01-01

326

4X source  

SciTech Connect

Our Penning surface-plasma source (SPS) discharge chamber was enlarged 4X in two dimensions. To date, three pulsed discharge modes have been studied: two with noisy arc (greater than or equal to 20% H/sup -/ current fluctuations) and one with quiescent arc (less than or equal to 1% H/sup -/ current fluctuations). Lower arc magnetic field and higher H/sub 2/ gas flow allow switching from the noisy to the quiescent mode. The noisy modes yield up to 120 mA of 29-keV H/sup -/ beam; for 110 mA at 29 keV, the two-dimensional normalized rms emittance is 0.017 x 0.018 ..pi...cm.mrad. The quiescent mode yields 75 mA of 29-keV H/sup -/beam; for 67 mA at 24 keV, the emittance is 0.011 x 0.012 ..pi...cm.mrad.

Smith, H.V. Jr.; Allison, P.; Sherman, J.D.

1985-01-01

327

Plasma source nitriding  

NASA Astrophysics Data System (ADS)

A new method of surface nitriding, called "plasma source nitriding", has been developed. This method is different from "ion nitriding" in the following respects: (1) the function of nitrogen- and hydrogen-ion bombardment of a workpiece is independent of the function of plasma production, (2) a homogeneity of nitriding depth is obtainable even if the geometrical shape of the workpiece is complicated, (3) the cost of nitriding gases is reduced due to the lower operating gas pressure which is of the order of 10 -4 Torr in the vacuum vessel, and (4) there is no trouble of arcing between workpieces and plasma. On the basis of the experimental results, the activation energy for nitrogen diffusion in 316 stainless steel by this method was calculated to be about 3.9 kcal/mol. This value was remarkably small compared to the value of 17.3 kcal/mol in 304 stainless steel by ion nitriding. The nitriding time was about 3 h by the new method and 15 h by ion nitriding to get a hardened depth of 27 ?m in 316 stainless steel; the nitriding time was shortened to one-fifth.

Nunogaki, M.; Suezawa, H.; Hayasi, K.; Miyazaki, K.

1988-09-01

328

Radiation sources working group summary  

SciTech Connect

The Radiation Sources Working Group addressed advanced concepts for the generation of RF energy to power advanced accelerators. The focus of the working group included advanced sources and technologies above 17 GHz. The topics discussed included RF sources above 17 GHz, pulse compression techniques to achieve extreme peak power levels, components technology, technology limitations and physical limits, and other advanced concepts. RF sources included gyroklystrons, magnicons, free-electron masers, two beam accelerators, and gyroharmonic and traveling wave devices. Technology components discussed included advanced cathodes and electron guns, high temperature superconductors for producing magnetic fields, RF breakdown physics and mitigation, and phenomena that impact source design such as fatigue in resonant structures due to RF heating. New approaches for RF source diagnostics located internal to the source were discussed for detecting plasma and beam phenomena existing in high energy density electrodynamic systems in order to help elucidate the reasons for performance limitations.

Fazio, M.V.

1998-12-31

329

Multiterminal source coding of Bernoulli-Gaussian correlated sources  

Microsoft Academic Search

This paper presents a practical coding scheme for the direct symmetric multiterminal source coding problem with remote source, when the noise between the remote source and the observations is Gaussian-Bernoulli-Gaussian. The idea behind the design is to take advantage from the observed symbols being in the real field, i n order to perform low-dimensional compressed sensing. The coding scheme is

Francesca Bassi; Michel Kieffer; Çagatay Dikici

2009-01-01

330

Reull Vallis Source Region  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] (Released 1 July 2002) The jumbled, chaotic terrain in this THEMIS image may represent a source region for the Reull Vallis, one of the larger channel systems in the southern hemisphere of Mars. Such regions of chaos are thought to form by the catastrophic release of groundwater. If this was the case, then the water would have flowed down gradient to the south and may have contributed to the formation of the Reull Vallis. The top of the image shows two short segments of channels that are interrupted by the chaos, demonstrating that there was a channel system in place before the ground foundered to produce the chaos. One of the more intriguing features seen among the jumbled blocks are narrow ledges that vaguely resemble bath tub rings in the way they conform to the topography. Two good examples are seen running roughly left-right across the image about a fourth of the way down. At first they appear to be layers protruding from the cliff faces, but upon closer inspection a more ledge-like character is evident. Note how they appear different between the south-facing and north facing cliffs. The occurrence of one of these features on the south-facing interior rim of the largest crater in the image but nowhere else around the rim argues against the idea that the ledges are due to a layer of rock cropping out throughout the landscape. Instead, they appear more like the edges of a layer of sediment that drapes the topography. It is possible that the sediment is mixed with ice and is best preserved in the shadowed portions of the terrain. There is no easy explanation for these unusual features. They represent one more Martian enigma.

2002-01-01

331

Portable source identification device  

NASA Astrophysics Data System (ADS)

U.S. Customs and Border Protection (CBP) is the primary enforcement agency protecting the nation"s ports of entry. CBP is enhancing its capability to interdict the illicit import of nuclear and radiological materials and devices that may be used by terrorists. Pacific Northwest National Laboratory (PNNL) is providing scientific and technical support to CBP in their goal to enable rapid deployment of nuclear and radiation detection systems at U. S. ports of entry to monitor 100% of the incoming international traffic and cargo while not adversely impacting the operations or throughput of the ports. As the deployment of radiation detection systems proceeds, there is a need to adapt the baseline radiation portal monitor (RPM) system technology to operations at these diverse ports of entry. When screening produces an alarm in the primary inspection RPM, the alarming vehicle is removed from the flow of commerce and the alarm is typically confirmed in a secondary inspection RPM. The portable source identification device (PSID) is a radiation sensor panel (RSP), based on thallium-doped sodium iodide (NaI(Tl)) scintillation detector and gamma spectroscopic analysis hardware and software, mounted on a scissor lift on a small truck. The lift supports a box containing a commercial off-the-shelf (COTS) sodium iodide detector that provides real-time isotopic identification, including neutron detectors to interdict Weapons of Mass Destruction (WMD) and radiation dispersion devices (RDD). The scissor lift will lower the detectors to within a foot off the ground and raise them to approximately 24 feet (7.3 m) in the air, allowing a wide vertical scanning range.

Andersen, Eric S.; Samuel, Todd J.; Gervais, Kevin L.

2005-05-01

332

Sources of Terrestrial Volatiles  

NASA Technical Reports Server (NTRS)

Atmospheres are found enveloping those planets and satellites best able to hold them. The obvious conclusion is that volatile escape must have played nearly as great a role as volatile supply. A consequence of this view is that volatile supplies were probably much greater than the atmospheres that remain. The likeliest candidates are sources associated with the main events of planetary accretion itself such as volatile-rich planetesimals, or direct gravitational capture of nebular gases. Late asteroidal or cometary volatile-rich veneers are attractive, but they present quantitative difficulties. Comets in particular are inadequate, because the associated mass of stray comets that would have been scattered to the Oort Cloud or beyond is excessive. This difficulty applies to Uranus-Neptune planetesimals as well as to a putative massive early Kuiper Belt. Another potential problem with comets is that the D/H ratio in the three comets for which this has been measured is about twice that of Earth's oceans. Objects falling from a much augmented ancient asteroid belt remain a viable option, but timing is an issue: Can the depopulation of the asteroid belt be delayed long enough that it makes sense to talk of asteroids as a late veneer? Early accretion of asteroids as objects scattered into the maw of infant Earth makes more sense. Another appealing candidate population of volatile-rich objects for the inner solar system would be scattered planetesimals associated with the accretion of Jupiter, for two reasons: (1) Before there was Jupiter, there was no object in the solar system capable of expelling comets efficiently, and (2) the cross section of the inner solar system to stray objects was Greater when there were m many planetesimals.

Zahnle, K. J.; Dones, L.

1998-01-01

333

Galactic bulge sources - What are they /X-ray sources in globular clusters and burst sources/  

SciTech Connect

Approximately 25 X-ray burst sources among the galactic bulge sources that lie within 30 deg of the direction of the galactic center are discussed in terms of soft spectra, variability, high luminosity and the absence of periodic pulsations and eclipses. Attention is given to the rapid burster MXB 1730-335 in addition, a sky map of Type-I burst sources is given, and a series of bursts from various sources is graphed which illustrate that bursts from one and the same source generally look similar. Burst intervals can be regular or irregular on time scales of hours to days, and a correlation between these intervals and the persistent X-ray emission was found in two burst sources. On the basis of spectral information and the success of the thermonuclear flash model, it is concluded that it is very likely that X-ray burst sources are neutron stars in low-mass binary systems.

Lewin, W.H.G.; Clark, G.W.

1980-01-01

334

The SIAM Photon Source  

SciTech Connect

A short history of the SIAM Photon Source in Thailand is described. The facility is based on the 1 GeV storage ring obtained from the SORTEC consortium in Japan. After a redesign to include insertion straight sections it produced the first light in December 2001 and the first beam line became operational in early 2002. Special difficulties appear when a synchrotron light facility is obtained by donation, which have mostly to do with the absence of human resource development that elsewhere is commonly accomplished during design and construction. Additional problems arise by the distance of a developing country like Thailand from the origin of technical parts of the donation. A donation does not provide time to generate local capabilities or include in the technical design locally obtainable parts. This makes future developments, repairs and maintenance more time consuming, difficult and expensive than it should be. In other cases, parts of components are proprietary or obsolete or both which requires redesign and engineering at a time when the replacement part should be available to prevent stoppage of operation.The build-up of a user community is very difficult, especially when the radiation spectrum is confined to the VUV regime. Most of scientific interest these days is focused on the x-ray regime. Due to its low beam energy, the SIAM storage ring did not produce useful x-ray intensities and we are therefore in the midst of an upgrade to produce harder radiation. The first step has been achieved with a 20% increase of energy to 1.2 GeV. This step shifts the critical photon energy of bending magnet radiation from 800 eV to 1.4 keV providing useful radiation up to 7 keV. A XAS-beam line has been completed in 2005 and experimentation is very active by now. The next step is to install a 6.4 T wavelength shifter by the end of 2006 resulting in a critical photon energy of 6.15 keV. Further upgrades are planed for the comming years.

Pairsuwan, Weerapong [National Synchrotron Research Center (NSRC), 111 University Avenue, Muang District, Nakhon Ratchasima (Thailand)

2007-01-19

335

Constricted glow discharge plasma source  

DOEpatents

A constricted glow discharge chamber and method are disclosed. The polarity and geometry of the constricted glow discharge plasma source is set so that the contamination and energy of the ions discharged from the source are minimized. The several sources can be mounted in parallel and in series to provide a sustained ultra low source of ions in a plasma with contamination below practical detection limits. The source is suitable for applying films of nitrides such as gallium nitride and oxides such as tungsten oxide and for enriching other substances in material surfaces such as oxygen and water vapor, which are difficult process as plasma in any known devices and methods. The source can also be used to assist the deposition of films such as metal films by providing low-energy ions such as argon ions.

Anders, Andre (Albany, CA); Anders, Simone (Albany, CA); Dickinson, Michael (San Leandro, CA); Rubin, Michael (Berkeley, CA); Newman, Nathan (Winnetka, IL)

2000-01-01

336

Embedded EZ-Source Inverters  

Microsoft Academic Search

Z-source inverters are recent topological options proposed for buck-boost energy conversion with a number of possible voltage- and current-type circuitries already reported in the literature. Comparing them, a common feature noted is their inclusion of an LC impedance network, placed between the dc input source and inverter bridge. This impedance network allows the output end of a voltage-type Z-source inverter

Poh Chiang Loh; Feng Gao; Frede Blaabjerg

2010-01-01

337

Spherical tokamak volume neutron source  

Microsoft Academic Search

Details are discussed of a volume neutron source for testing assemblies such as blanket sections in a 14 MeV neutron environment. This neutron source is based on the spherical tokamak. The experimentally confirmed ability of the spherical tokamak to reach very high plasma pressures makes it ideally suited as the basis for a very compact neutron source (R?0.7 m, Ip?7–12

T. C. Hender; G. M. Voss; N. P. Taylor

1999-01-01

338

The Frankfurt PIG ion source  

NASA Astrophysics Data System (ADS)

A small sized, versatile PIG ion source with end extraction is described by which positive ion beams of most of the elements can be produced with intensities in the microampere range. The source operates either with gas or with a mixture of gas and metal vapor. In the latter case the supply of the metal atoms to the gas discharge is done by evaporation or sputtering depending on the kind of metal. A characteristic feature of the source is the small power consumption so that cooling of the source housing by air only is sufficient.

Baumann, H.; Bethge, K.

1981-10-01

339

Neutron imaging of radioactive sources  

NASA Astrophysics Data System (ADS)

Isotopic neutron sources have been available for more than six decades. At the Atomic Institute in Vienna, operating a 250 kW TRIGA reactor, different neutron sources are in use for instrument calibration and fast neutron applications but we have only little information about their construction and densities. The knowledge of source design is essential for a complete MCNP5 modeling of the experiments. Neutron radiography (NR) and neutron tomography (NT) are the best choices for the non-destructive inspection of the source geometry and homogeneity. From the transmission analysis we gain information about the shielding components and the densities of the radio-isotopes in the cores. Three neutron sources, based on (alpha, n) reaction, have been investigated, two 239PuBe sources and one 241AmBe source. In the NR images the internal structure was clearly revealed using high-resolving scintillation and imaging plate detectors. In one source tablet a crack was detected which causes asymmetric neutron emission. The tomography inspection of strong absorbing materials is more challenging due to the low beam intensity of 1.3x105 n/cm2s at our NT instrument, and due to the beam hardening effect which requires an extension of reconstruction software. The tomographic inspection of a PuBe neutron source and appropriate measures for background and beam hardening correction are presented.

Hameed, F.; Karimzadeh, S.; Zawisky, M.

2008-08-01

340

Enhancement of SPES source performances  

SciTech Connect

Installation of SPES source at LNL was finished in July 2006 and the first beam was extracted in September 2006. Commissioning results confirmed very good performance of the extracted current density. Conversely, source reliability was very poor due to glow-discharge phenomena, which were caused by the ion source axial magnetic field protruding in the high-voltage column. This problem was fixed by changing the stainless steel plasma electrode support with a ferromagnetic one. This new configuration required us to recalculate ion source solenoids positions and fields in order to recover the correct resonance pattern. Details on magnetic simulations and experimental results of high voltage column shielding are presented.

Fagotti, E.; Palmieri, A.; Ren, X. [Consorzio RFX, Corso Stati Uniti, 4 35129 Padova (Italy); INFN Laboratori Nazionali di Legnaro, Viale dell'Universita, 2 35020 Legnaro, Padova (Italy)

2008-02-15

341

INVERSE SOURCE STRENGTH RECONSTRUCTION TECHNIQUES FOR DUCTED ACOUSTIC SOURCES  

Microsoft Academic Search

The aeronautic, aerospace and automotive industries require improved noise reduction techniques to meet the current normative and increase the acoustic comfort at acceptable cost. The aim of this work is to investigate the capabilities of inverse methods for the noise source reconstruction of ducted acoustic sources in a laboratory acoustic facility installed in a semi anechoic chamber. Model-based inverse methods

Teresa Bravo; Cédric Maury

342

SOURCE PARTITIONING USING STABLE ISOTOPES: COPING WITH TOO MANY SOURCES  

EPA Science Inventory

Stable isotopes are increasingly being used as tracers in environmental studies. One application is to use isotopic ratios to quantitatively determine the proportional contribution of several sources to a mixture, such as the proportion of various pollution sources in a waste st...

343

The status of the spallation neutron source ion source  

NASA Astrophysics Data System (ADS)

The ion source for the spallation neutron source (SNS) is a radio-frequency, multicusp source designed to deliver 45 mA of H- to the SNS accelerator with a pulse length of 1 ms and repetition rate of 60 Hz. A total of three ion sources have been fabricated and commissioned at Lawrence Berkeley National Laboratory and subsequently delivered to the SNS at the Oak Ridge National Laboratory. The ion sources are currently being rotated between operation on the SNS accelerator, where they are involved in ongoing efforts to commission the SNS LINAC, and the hot spare stand (HSS), where high-current tests are in progress. Commissioning work involves operating the source in a low duty-factor mode (pulse width ~200 ?s and repetition rate ~5 Hz) for extended periods of time while the high-current tests involve source operation at full duty-factor of 6% (1 ms/60 Hz). This report discusses routine performance of the source employed in the commissioning role as well as the initial results of high-current tests performed on the HSS.

Welton, R. F.; Stockli, M. P.; Murray, S. N.; Keller, R.

2004-05-01

344

Thermal Management of Light Sources  

NASA Astrophysics Data System (ADS)

The primary task of light sources is illumination, i.e., the emission of visible radiation—light. However, depending on the generation principle, besides light, also heat will be dissipated to the surroundings. Traditional thermal light sources generate light by the electrical heating of a tungsten wire to temperatures of about 3000 K. Even at this high temperature, the majority of the emitted thermal radiation is within the long wavelength range of the spectrum, i.e., not in the visible range of the optical spectrum. Generation of light with discharge lamps is completely different and non-thermal; however, even in this case the electrodes are heated to temperatures well above 2000 K. Thus, discharge lamps also suffer from thermal problems. In the case of solid-state light sources, also non-thermal light sources, the driving electrical current causes heating of the device, for which the temperature is, or should usually be, below 420 K for proper operation. Contrary to thermal or discharge light sources, such relatively low temperatures of solid-state light sources prevent efficient cooling by thermal radiation, requiring convective or conductive cooling. However, for all mentioned light sources, the thermal management, i.e., the adjusting and maintaining of an optimum operation temperature are vital for the efficiency and lifetime of the light sources. This paper deals with the methods of generation and measurement of the thermal load in the respective light sources and discusses ways to optimize the efficiency and lifetime of such light sources. Also, some practical examples are given to emphasize the relevance of such thermal management for industry, pointing out the potential for future more energy-efficient light source concepts.

Hartmann, J.; Völker, Stephan

2011-01-01

345

Ion source choices - an h- source for the high intensity neutrino source  

SciTech Connect

The High Intensity Neutrino Source (HINS) program at Fermilab (formerly the Proton Driver) aims to develop a multi-mission linear accelerator (LINAC) capable of accelerate H{sup -} ions to 8 GeV. This paper touches on the ion source requirements for the HINS and discusses long pulse length testing of three ion sources which appear to have the capability of meeting these requirements.

Moehs, Douglas P.; /Fermilab; Welton, Robert F.; /SNS Project, Oak Ridge; Stockli, Martin P.; Peters, Jens; /DESY; Alessi, James; /Brookhaven

2006-08-01

346

Sources of human urinary epinephrine  

Microsoft Academic Search

Sources of human urinary epinephrine. The kidney is a likely source for some urinary epinephrine (E) since adrenalectomized animals and humans continue to excrete urinary E and the human kidney contains E synthesizing enzymes. We studied subjects during an intravenous infusion of 3H-E to determine the fraction of urinary E derived from the kidney. Eight normal subjects (CON) and 5

Michael G Ziegler; Myo Aung; Brian Kennedy

1997-01-01

347

Hollow electrode plasma excitation source  

DOEpatents

A plasma source incorporates a furnace as a hollow anode, while a coaxial cathode is disposed therewithin. The source is located in a housing provided with an ionizable gas such that a glow discharge is produced between anode and cathode. Radiation or ionic emission from the glow discharge characterizes a sample placed within the furnace and heated to elevated temperatures.

Ballou, Nathan E. (West Richland, WA)

1992-01-01

348

High Power Arc Light Sources.  

National Technical Information Service (NTIS)

Light or infrared sources in the 1 to 10 megawatt power range are usable for a variety of listed military and nonmilitary functions. The carbon arc source appears to be less limited physically, in terms of ultimate continuous power output, than the high p...

J. F. Holt R. B. Rivir

1971-01-01

349

SUS Source Level Committee Report.  

National Technical Information Service (NTIS)

This is the final report of the SUS Source Level Committee, which was established by the Manager, Long Range Acoustic Propagation Project to investigate the source levels of small explosive charges, principally SUS. The need for the study arose because of...

1975-01-01

350

Sources of the Medical Vocabulary.  

ERIC Educational Resources Information Center

In an attempt to determine as precisely as possible just how much of medical vocabulary is derived from every source, the vocabulary defined in the 24th edition of "Dorland's Illustrated Medical Dictionary" was analyzed. Results indicate that medical vocabulary is relying increasingly upon the Greek and Latin languages as the sources of its…

Butler, Roy F.

1980-01-01

351

Accelerator-based Neutron Sources  

Microsoft Academic Search

Since the earliest experiments defining the properties of the neutron, accelerators have played an important role in providing neutrons for research and applications. For many years, neutrons produced at accelerator facilities have complemented capabilities available from reactor-based sources. Now, with the declining availability of reactor facilities, upgrades of existing accelerator facilities and proposed new, more powerful accelerator-based sources will be

James B. Ball

1997-01-01

352

Ultra-wideband source research  

Microsoft Academic Search

Ultra-wideband (UWB) microwave sources and antennas are of interest for a variety of applications such as transient radar, mine detection and unexploded ordnance (UXO) location and identification. Much of the current research is being performed at the Air Force Research Laboratory (AFRL) at Kirtland AFB, NM, USA. The approach to high power source development has included high pressure gas switching,

William D. Prather; Carl E. Baum; Jane M. Lehr; J. P. O'Loughlin; S. Tyo; J. S. H. Schoenberg; R. J. Torres; T. C. Tran; D. W. Scholfield; J. W. Burger; J. Gaudet

1999-01-01

353

Parametric localization of distributed sources  

Microsoft Academic Search

Most array processing algorithms are based on the assumption that the signals are generated by point sources. This is a mathematical constraint that is not satisfied in many applications. In this paper, we consider situations where the sources are distributed in space with a parametric angular cross-correlation kernel. We propose an algorithm that estimates the parameters of this model using

Shahrokh Valaee; Benoit Champagne; Peter Kabal

1995-01-01

354

Developmental changes in source memory  

Microsoft Academic Search

Remembering how one learned a fact can be important in itself (e.g. for considering the value of information). However, source memory is also important, along with the temporal and perceptual information on which it is based, in giving memory an episodic or autobiographical quality. The present study investigated developmental changes in children's ability to monitor source, in a paradigm adapted

Anna B. Drummey; Nora S. Newcombe

2002-01-01

355

Scientists debate nuclear source terms  

Microsoft Academic Search

The nuclear source term, defined as the quantity, timing, and characteristic of the release of radioactive material to the environment following a core-melt accident, was thoroughly debated in 1985. This debate, summarized here, turns on the Nuclear Regulatory Commission's (NRC) source term for radioactive iodine, which is postulated as potentially the most life-threatening radionuclide that might escape in a nuclear

2009-01-01

356

Composing Mappings Among Data Sources  

Microsoft Academic Search

Semantic mappings between data sources play a key role in several data sharing architectures. Mappings provide the relationships between data stored in dif- ferent sources, and therefore enable answering queries that require data from other nodes in a data shar- ing network. Composing mappings is one of the core problems that lies at the heart of several optimization methods in

Jayant Madhavan; Alon Y. Halevy

2003-01-01

357

High current polarized proton sources  

SciTech Connect

Polarized proton sources are now being used more frequently on linacs. In pulsed operation up to 10 mA of /rvec H//sup +/ and 0.4 mA of /rvec H//sup /minus// have been produced. The present status of these sources, and developments to reach even higher intensities, are reviewed. 39 refs., 1 tab.

Alessi, J.G.

1988-01-01

358

The Chandra Source Catalog: Algorithms  

Microsoft Academic Search

Creation of the Chandra Source Catalog (CSC) required adjustment of existing pipeline processing, adaptation of existing interactive analysis software for automated use, and development of entirely new algorithms. Data calibration was based on the existing pipeline, but more rigorous data cleaning was applied and the latest calibration data products were used. For source detection, a local background map was created

Jonathan C. McDowell; I. N. Evans; F. A. Primini; K. J. Glotfelty; M. L. McCollough; J. C. Houck; M. A. Nowak; M. Karovska; J. E. Davis; A. H. Rots; A. L. Siemiginowska; R. Hain; J. D. Evans; C. S. Anderson; N. R. Bonaventura; J. C. Chen; S. M. Doe; G. Fabbiano; E. Galle; D. G. Gibbs; J. D. Grier; D. M. Hall; P. N. Harbo; X. He; J. Lauer; J. B. Miller; A. W. Mitschang; D. L. Morgan; J. S. Nichols; D. A. Plummer; B. L. Refsdal; B. A. Sundheim

2009-01-01

359

SULFUR DIOXIDE SOURCES IN AK  

EPA Science Inventory

This map shows industrial plants which emit 100 tons/year or more of sulfur dioxide (SO2) in Alaska. The SO2 sources are plotted on a background map of cities and county boundaries. Data Sources: SO2 Sites: U.S. EPA AIRS System, County Outlines: 1990 Census Tiger Line Files 1:1...

360

FORTRAN Static Source Code Analyzer  

NASA Technical Reports Server (NTRS)

FORTRAN Static Source Code Analyzer program (SAP) automatically gathers and reports statistics on occurrences of statements and structures within FORTRAN program. Provisions are made for weighting each statistic, providing user with overall figure of complexity. Statistics, as well as figures of complexity, are gathered on module-by-module basis. Overall summed statistics are accumulated for complete input source file.

Merwarth, P.

1982-01-01

361

Tokamak as a Neutron Source.  

National Technical Information Service (NTIS)

This paper describes the tokamak in its role as a neutron source, with emphasis on experimental results for D-D neutron production. The sections summarize tokamak operation, sources of fusion and non-fusion neutrons, principal neutron detection methods an...

H. W. Hendel D. L. Jassby

1989-01-01

362

Hollow electrode plasma excitation source  

DOEpatents

A plasma source incorporates a furnace as a hollow anode, while a coaxial cathode is disposed therewithin. The source is located in a housing provided with an ionizable gas such that a glow discharge is produced between anode and cathode. Radiation or ionic emission from the glow discharge characterizes a sample placed within the furnace and heated to elevated temperatures. 5 figs.

Ballou, N.E.

1992-04-14

363

Sound Source Localization by Fishes  

Microsoft Academic Search

General understanding of the sense of hearing in nonhuman species probably arises from human experiences, introspections, and experiments on human listeners. Whenever we hear a sound, a little attention to it usually reveals that its source exists somewhere in the space around us, and our ability to point toward the source is reasonably good in most simple environments. The locations

Richard R. Fay

364

METHANE EMISSIONS FROM INDUSTRIAL SOURCES  

EPA Science Inventory

The chapter identifies and describes major industrial sources of methane (CH4) emissions. or each source type examined, it identifies CH4 release points and discusses in detail the factors affecting emissions. t also summarizes and discusses available global and country-specific ...

365

Cretaceous source rocks in Pakistan  

SciTech Connect

Pakistan is located at the converging boundaries of the Indian, Arabian, and Eurasian plates. Evolution of this tectonic setting has provided an array of environmental habitats for deposition of petroleum source rocks and development of structural forms. The potential Cretaceous source rocks in Central and South Indus Basin are spread over an area of about 300,000 km[sup 2]. With 2% cutoff on Total Organic Carbon, the average source rock thickness is 30-50 m, which is estimated to have generated more than 200 billion bbl of oil equivalent. To date, production of more than 30,000 bbl of oil and about 1200 million ft[sup 3] of gas per day can be directly attributed to Cretaceous source. This basin was an area of extensional tectonics during the Lower to Middle Cretaceous associated with slightly restricted circulation of the sea waters at the north-western margin of Indian Plate. Lower Cretaceous source rocks (Sembar Formation) were deposited while the basin was opening up and anoxia was prevailing. Similarly Middle to Upper Cretaceous clastics were deposited in setting favorable for preservation of organic matter. The time and depth of burial of the Cretaceous source material and optimum thermal regime have provided the requisite maturation level for generation of hydrocarbons in the basin. Central Indus basin is characterized by Cretaceous source rocks mature for gas generation. However, in South Indus Basin Cretaceous source rocks lie within the oil window in some parts and have gone past it in others.

Kari, I.B. (Pakistan Petroleum Limited, Sindh (Pakistan))

1993-02-01

366

Community Open Source Strategic Plan.  

National Technical Information Service (NTIS)

The Strategic Plan describes the goals and objectives of the Community Open Source Program for the next seven years. It builds on the half-century-plus heritage of Open Source Information providers and users in the Intelligence Community. The Plan project...

1995-01-01

367

Idaho Source Water Assessment Plan.  

National Technical Information Service (NTIS)

The Idaho Source Water Assessment Plan was developed in response to requirements set forth by the Safe Drinking Water Act Amendments passed by Congress in 1996. The Safe Drinking Water Act Amendments require states to assess the water (called source water...

1999-01-01

368

Building the Advanced Photon Source  

SciTech Connect

This timelapse video shows the U.S. Department of Energy's Advanced Photon Source (APS) rising from an empty field at Argonne National Laboratory to become the source of the Western Hemisphere's brightest x-rays for research. The video was compiled from still photographs taken from 1990-1996.

None

2010-01-01

369

Sealed source peer review plan  

SciTech Connect

Sealed sources are known quantities of radioactive materials that have been encapsulated in quantities that produce known radiation fields. Sealed sources have multiple uses ranging from instrument calibration sources to sources that produce radiation fields for experimental applications. The Off-Site Source Recovery (OSR) Project at Los Alamos National Laboratory (LANL), created in 1999, under the direction of the Waste Management Division of the U.S. Department of Energy (DOE) Albuquerque has been assigned the responsibility to recover and manage excess and unwanted radioactive sealed sources from the public and private sector. LANL intends to ship drums containing qualified sealed sources to the Waste Isolation Pilot Plant (WIPP) for disposal. Prior to shipping, these drums must be characterized with respect to radiological content and other parameters. The U. S. Environmental Protection Agency (EPA) requires that ten radionulcides be quantified and reported for every container of waste to be disposed in the WIPP. The methods traditionally approved by the EPA include non-destructive assay (NDA) in accordance with Appendix A of the Contact-Handled Transuranic Waste Acceptance Criteria for the Waste Isolation Pilot Plant (DOE, 2002) (CH WAC). However, because of the nature and pedigree of historical records for sealed sources and the technical infeasibility of performing NDA on these sources, LANL proposes to characterize the content of these waste drums using qualified existing radiological data in lieu of direct measurement. This plan describes the process and documentation requirements for the use of the peer review process to qualify existing data for sealed radiological sources in lieu of perfonning radioassay. The peer review process will be performed in accordance with criteria provided in 40 CFR {section} 194.22 which specifies the use of the NUREG 1297 guidelines. The plan defines the management approach, resources, schedule, and technical requirements for the subject peer review.

Feldman, Alexander [Los Alamos National Laboratory; Leonard, Lee [RETIRED; Burns, Ron [CONTRACTOR

2009-01-01

370

Radio sources in the vicinity of source m 31.  

PubMed

The region alpha (right ascension) equal to 23(h) 50(m) to 01(h) 30(m), delta (declination) 39 degrees 20' to 40 degrees 40' has been observed at 195 and 430 megahertz with the 1000-foot (300 m) telescope of the Arecibo Ionospheric Observatory. Eighteen sources from the Ohio Catalogue and source 3C 13 are contained in this region. We conclude that the sources have straight-line spectra with indices between -0.4 and -0.9 and that they are probably not associated with M 31, except those within the optical limit of the nebula. PMID:17811618

Varsavsky, C M

1967-11-24

371

Major System Source Evaluation and Selection Procedures.  

National Technical Information Service (NTIS)

source evaluation and selection, contracting requirements and procedures,Planning for source selection, initiating an acquisition, organization for source selection, functions of the source selection organization, evaluation criteria and standards, scorin...

1987-01-01

372

Sources of Stem Cells for Transplant  

MedlinePLUS

... Donor matching for allogeneic transplant Sources of stem cells for transplant There are 3 possible sources of ... blood transplants are being actively studied. Which stem cell source is best? All 3 sources of stem ...

373

Reversal ion source - A new source of negative ion beams  

NASA Technical Reports Server (NTRS)

A new type of ion source utilizing beams of electrons and target molecules, rather than a diffuse, volume plasma, is described. The source utilizes an electrostatic electron 'mirror' which reverses trajectories in an electron beam, producing electrons at their turning point having a distribution of velocities centered at zero velocity. A gas which attaches zero-velocity electrons is introduced at this turning point. Negative ions are produced by an attachment or dissociative attachment process. For many of the thermal electron-attaching molecules the cross sections can be quite large, varying as the inverse square root of the electron energy or just the s-wave threshold law. The efficiency and current density of the ion source for production of Cl(-) through the large, thermal energy attachment process is estimated. It is argued that the source can be used for the production of negative ions through attachment resonances located at higher energies as well.

Orient, O. J.; Chutjian, A.; Alajajian, S. H.

1985-01-01

374

Source and Propagation Characteristics of Explosive and Other Seismic Sources  

SciTech Connect

Understanding of the source and propagation characteristics of seismic events of different types including earthquakes, explosions and mining-induced events is essential for successful discrimination of nuclear explosions. We are compiling a data set of mining related seismic events in east Eurasia. Natural earthquake data in the same region are also collected for comparison study between mining related events and earthquakes. The ground-truth data set will provide a unique and valuable resource for monitoring research. We will utilize the data set to investigate the source and propagation characteristics of seismic sources of different types including mine blasts, tremors, collapses and earthquakes. We will use various seismological techniques including spectral analysis, and waveform modeling to conduct the investigation. The research will improve our understanding of the S-wave excitation and propagation characteristics of chemical explosions and other source types.

Ni, X; Chan, W; Wagner, R; Walter, W R; Matzel, E M

2005-07-14

375

Source and Propagation Characteristics of Explosive and Other Seismic Sources.  

National Technical Information Service (NTIS)

Understanding of the source and propagation characteristics of seismic events of different types including earthquakes, explosions and mining-induced events is essential for successful discrimination of nuclear explosions. We are compiling a data set of m...

X. Ni W. Chan R. Wagner W. R. Walter E. M. Matzel

2005-01-01

376

Spallation source neutron target systems  

SciTech Connect

This is the final report for a two-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project sought to design a next-generation spallation source neutron target system for the Manuel Lujan, Jr., Neutron Scattering Center (LANSCE) at Los Alamos. It has been recognized for some time that new advanced neutron sources are needed in the US if the country is to maintain a competitive position in several important scientific and technological areas. A recent DOE panel concluded that the proposed Advanced Neutron Source (a nuclear reactor at Oak Ridge National Laboratory) and a high-power pulsed spallation source are both needed in the near future. One of the most technically challenging designs for a spallation source is the target station itself and, more specifically, the target-moderator-reflector arrangement. Los Alamos has demonstrated capabilities in designing, building, and operating high-power spallation-neutron-source target stations. Most of the new design ideas proposed worldwide for target system design for the next generation pulsed spallation source have either been conceived and implemented at LANSCE or proposed by LANSCE target system designers. These concepts include split targets, flux-trap moderators, back scattering and composite moderators, and composite reflectors.

Russell, G.; Brown, R.; Collier, M.; Donahue, J. [and others

1996-07-01

377

Major sources of benzene exposure.  

PubMed Central

Data from EPA's TEAM Study allow us to identify the major sources of exposure to benzene for much of the U.S. population. These sources turn out to be quite different from what had previously been considered the important sources. The most important source of exposure for 50 million smokers is the mainstream smoke from their cigarettes, which accounts for about half of the total population burden of exposure to benzene. Another 20% of nationwide exposure is contributed by various personal activities, such as driving and using attached garages. (Emissions from consumer products, building materials, paints, and adhesives may also be important, although data are largely lacking.) The traditional sources of atmospheric emissions (auto exhaust and industrial emissions) account for only about 20% of total exposure. Environmental tobacco smoke is an important source, accounting for about 5% of total nationwide exposure. A number of sources sometimes considered important, such as petroleum refining operations, petrochemical manufacturing, oil storage tanks, urban-industrial areas, service stations, certain foods, groundwater contamination, and underground gasoline leaks, appear to be unimportant on a nationwide basis.

Wallace, L A

1989-01-01

378

International Data on Radiological Sources  

SciTech Connect

ABSTRACT The mission of radiological dispersal device (RDD) nuclear forensics is to identify the provenance of nuclear and radiological materials used in RDDs and to aid law enforcement in tracking nuclear materials and routes. The application of databases to radiological forensics is to match RDD source material to a source model in the database, provide guidance regarding a possible second device, and aid the FBI by providing a short list of manufacturers and distributors, and ultimately to the last legal owner of the source. The Argonne/Idaho National Laboratory RDD attribution database is a powerful technical tool in radiological forensics. The database (1267 unique vendors) includes all sealed sources and a device registered in the U.S., is complemented by data from the IAEA Catalogue, and is supported by rigorous in-lab characterization of selected sealed sources regarding physical form, radiochemical composition, and age-dating profiles. Close working relationships with global partners in the commercial sealed sources industry provide invaluable technical information and expertise in the development of signature profiles. These profiles are critical to the down-selection of potential candidates in either pre- or post- event RDD attribution. The down-selection process includes a match between an interdicted (or detonated) source and a model in the database linked to one or more manufacturers and distributors.

Martha Finck; Margaret Goldberg

2010-07-01

379

A Source-to-Source OpenMP Compiler  

Microsoft Academic Search

In this paper we describe an implementation of the Fortran OpenMP standard for compiler-directed shared-memory parallel programming. The implementation is source-to- source, i.e., it takes as input a Fortran program with OpenMP directives and produces a Fortran program which explicitly creates and manages parallelism according to the specified directives. This makes the implementation portable, only requiring a standard POSIX thread

Mario Soukup; Tarek S. Abdelrahman

2001-01-01

380

Experiences in Using Cetus for Source-to-Source Transformations  

Microsoft Academic Search

Cetus is a compiler infrastructure for the source-to-source transformation of programs. Since its creation nearly three years ago, it has grown to over 12,000 lines of Java code, been made available pub- lically on the web, and become a basis for several research projects. We discuss our experience using Cetus for a selection of these research projects. The focus of

Troy A. Johnson; Sang-Ik Lee; Long Fei; Ayon Basumallik; Gautam Upadhyaya; Rudolf Eigenmann; Samuel P. Midkiff

2004-01-01

381

Spallation neutron source and other high intensity froton sources  

SciTech Connect

This lecture is an introduction to the design of a spallation neutron source and other high intensity proton sources. It discusses two different approaches: linac-based and synchrotron-based. The requirements and design concepts of each approach are presented. The advantages and disadvantages are compared. A brief review of existing machines and those under construction and proposed is also given. An R&D program is included in an appendix.

Weiren Chou

2003-02-06

382

The EUVE bright source list  

NASA Technical Reports Server (NTRS)

Initial results for bright extreme ultraviolet sources discovered during the EUVE all-sky and deep ecliptic surveys have been published as a Bright Source List (BSL) and released to the astronomical community with a recent NASA research announcement (NRA 93-OSS-02, Appendix F). This paper describes the data processing software, the EUVE survey data set, and the production of the BSL at the Center for EUV Astrophysics. The contents, format, and selection criteria for sources, the data processing strategy, some problems encountered, and a summary of the BSL results are presented.

Stroozas, B.; Mcdonald, K.; Antia, B.; Mcdonald, J.; Wiercigroch, A.

1993-01-01

383

Three chamber negative ion source  

DOEpatents

It is an object of this invention provide a negative ion source which efficiently provides a large flux of negatively ionized particles. This invention provides a volume source of negative ions which has a current density sufficient for magnetic fusion applications and has electrons suppressed from the output. It is still another object of this invention to provide a volume source of negative ions which can be electrostatically accelerated to high energies and subsequently neutralized to form a high energy neutral beam for use with a magnetically confined plasma.

Leung, K.N.; Ehlers, K.W.; Hiskes, J.R.

1983-11-10

384

Oceanic sources of continental precipitation  

NASA Astrophysics Data System (ADS)

this special section, the authors have tried to address some of the many unanswered questions related to the transport of moisture from oceanic sources to the continents, including among others that of whether or not the moisture source regions have remained stationary over time, how the many changes in the intensity and position of the sources have affected the distribution of continental precipitation, and also the question of the role of the main modes of climate variability in the variability of the moisture regions.

Gimeno, Luis

2014-05-01

385

An Open Source Simulation System  

NASA Technical Reports Server (NTRS)

An investigation into the current state of the art of open source real time programming practices. This document includes what technologies are available, how easy is it to obtain, configure, and use them, and some performance measures done on the different systems. A matrix of vendors and their products is included as part of this investigation, but this is not an exhaustive list, and represents only a snapshot of time in a field that is changing rapidly. Specifically, there are three approaches investigated: 1. Completely open source on generic hardware, downloaded from the net. 2. Open source packaged by a vender and provided as free evaluation copy. 3. Proprietary hardware with pre-loaded proprietary source available software provided by the vender as for our evaluation.

Slack, Thomas

2005-01-01

386

Current Controlled Voltage Source (CCVS)  

NSDL National Science Digital Library

This interactive website from professor James A. Svoboda of Clarkson University describes a circuit that contains a Current Controlled Voltage Source (CCVS). The gain of the CCVS can be changed using the scrollbar.

Svoboda, James A.

2012-12-17

387

Electrolyte salts for power sources  

DOEpatents

Electrolyte salts are disclosed for power sources comprising salts of phenyl polysulfonic acids and phenyl polyphosphonic acids. The preferred salts are alkali and alkaline earth metal salts, most preferably lithium salts. 2 figs.

Doddapaneni, N.; Ingersoll, D.

1995-11-28

388

Point sources of air pollution.  

PubMed

Many people live near point sources of air pollution such as industrial sites and waste disposal operations and there are often suggestions of clusters of disease around such activities. Such alleged clusters will generate significant public concern and media interest and in many cases will warrant detailed investigation. However, the ability of current epidemiological methods to investigate such clusters is limited, particularly with regard to obtaining reliable and accurate population exposure data. In many cases, the key question is whether releases from a point source result in a significant increase in exposure or whether other sources (background exposure) give rise to the dominant exposure. This review considers some of the issues around point sources including methods of estimating exposure and briefly discusses some of the epidemiological evidence linking respiratory disease and cancer with specific industries such as coking works and incinerators. PMID:16140835

Kibble, Andrew; Harrison, Roy

2005-09-01

389

Environmental sources of fecal bacteria  

USGS Publications Warehouse

This chapter provides a review of the research on environmental occurrences of faecal indicator bacteria in a variety of terrestrial and aquatic habitats under different geographic and climatic conditions, and discusses how these external sources may affect surface water quality.

Byappanahalli, Muruleedhara N.; Ishii, Satoshi

2011-01-01

390

Advanced Photon Source control system.  

National Technical Information Service (NTIS)

The Advanced Photon Source (APS), now under construction at Argonne National Laboratory (ANL), is a 7-GeV positron storage ring dedicated to research facilities using synchrotron radiation. This ring, along with its injection accelerators is to be control...

M. J. Knott W. P. McDowell F. R. Lenkszus M. R. Kraimer N. D. Arnold

1991-01-01

391

Microbial Source Tracking Guide Document.  

National Technical Information Service (NTIS)

The purpose of this guide is to provide scientists, engineers, and environmental managers with a comprehensive, interpretive analysis of the current and relevant information (based on both lab and field data) related to Microbial Source Tracking (MST). De...

2005-01-01

392

Orthotropic source of thermal atoms.  

National Technical Information Service (NTIS)

A source of thermal atoms that emits 100% of its atoms into a narrow beam with small angular divergence is described. It uses both surface ionization and surface neutralization in conjunction with electric fields to selectively emit a highly directional (...

T. Dinneen A. Ghiorso H. Gould

1995-01-01

393

New Sources of Fungal Dextranase.  

National Technical Information Service (NTIS)

Previously unreported dextranase activity was discovered in several species of Fusarium and in Penicillium roquefortii. One of the new sources of dextranase, Fusarium moniliforme, was selected for further study. The initial cultural pH affected both colon...

L. G. Simonson A. E. Liberta

1975-01-01

394

Source Identification and Location Techniques  

NASA Technical Reports Server (NTRS)

Mr. Weir presented source location results obtained from an engine test as part of the Engine Validation of Noise Reduction Concepts program. Two types of microphone arrays were used in this program to determine the jet noise source distribution for the exhaust from a 4.3 bypass ratio turbofan engine. One was a linear array of 16 microphones located on a 25 ft. sideline and the other was a 103 microphone 3-D "cage" array in the near field of the jet. Data were obtained from a baseline nozzle and from numerous nozzle configuration using chevrons and/or tabs to reduce the jet noise. Mr. Weir presented data from two configurations: the baseline nozzle and a nozzle configuration with chevrons on both the core and bypass nozzles. This chevron configuration had achieved a jet noise reduction of 4 EPNdB in small scale tests conducted at the Glenn Research Center. IR imaging showed that the chevrons produced significant improvements in mixing and greatly reduced the length of the jet potential core. Comparison of source location data from the 1-D phased array showed a shift of the noise sources towards the nozzle and clear reductions of the sources due to the noise reduction devices. Data from the 3-D array showed a single source at a frequency of 125 Hz. located several diameters downstream from the nozzle exit. At 250 and 400 Hz., multiple sources, periodically spaced, appeared to exist downstream of the nozzle. The trend of source location moving toward the nozzle exit with increasing frequency was also observed. The 3-D array data also showed a reduction in source strength with the addition of chevrons. The overall trend of source location with frequency was compared for the two arrays and with classical experience. Similar trends were observed. Although overall trends with frequency and addition of suppression devices were consistent between the data from the 1-D and the 3-D arrays, a comparison of the details of the inferred source locations did show differences. A flight test is planned to determine if the hardware tested statically will achieve similar reductions in flight.

Weir, Donald; Bridges, James; Agboola, Femi; Dougherty, Robert

2001-01-01

395

H- radio frequency source development at the Spallation Neutron Source.  

PubMed

The Spallation Neutron Source (SNS) now routinely operates nearly 1 MW of beam power on target with a highly persistent ?38 mA peak current in the linac and an availability of ?90%. H(-) beam pulses (?1 ms, 60 Hz) are produced by a Cs-enhanced, multicusp ion source closely coupled with an electrostatic low energy beam transport (LEBT), which focuses the 65 kV beam into a radio frequency quadrupole accelerator. The source plasma is generated by RF excitation (2 MHz, ?60 kW) of a copper antenna that has been encased with a thickness of ?0.7 mm of porcelain enamel and immersed into the plasma chamber. The ion source and LEBT normally have a combined availability of ?99%. Recent increases in duty-factor and RF power have made antenna failures a leading cause of downtime. This report first identifies the physical mechanism of antenna failure from a statistical inspection of ?75 antennas which ran at the SNS, scanning electron microscopy studies of antenna surface, and cross sectional cuts and analysis of calorimetric heating measurements. Failure mitigation efforts are then described which include modifying the antenna geometry and our acceptance?installation criteria. Progress and status of the development of the SNS external antenna source, a long-term solution to the internal antenna problem, are then discussed. Currently, this source is capable of delivering comparable beam currents to the baseline source to the SNS and, an earlier version, has briefly demonstrated unanalyzed currents up to ?100 mA (1 ms, 60 Hz) on the test stand. In particular, this paper discusses plasma ignition (dc and RF plasma guns), antenna reliability, magnet overheating, and insufficient beam persistence. PMID:22380234

Welton, R F; Dudnikov, V G; Gawne, K R; Han, B X; Murray, S N; Pennisi, T R; Roseberry, R T; Santana, M; Stockli, M P; Turvey, M W

2012-02-01

396

H- radio frequency source development at the Spallation Neutron Source  

SciTech Connect

The Spallation Neutron Source (SNS) now routinely operates nearly 1 MW of beam power on target with a highly persistent {approx}38 mA peak current in the linac and an availability of {approx}90%. H{sup -} beam pulses ({approx}1 ms, 60 Hz) are produced by a Cs-enhanced, multicusp ion source closely coupled with an electrostatic low energy beam transport (LEBT), which focuses the 65 kV beam into a radio frequency quadrupole accelerator. The source plasma is generated by RF excitation (2 MHz, {approx}60 kW) of a copper antenna that has been encased with a thickness of {approx}0.7 mm of porcelain enamel and immersed into the plasma chamber. The ion source and LEBT normally have a combined availability of {approx}99%. Recent increases in duty-factor and RF power have made antenna failures a leading cause of downtime. This report first identifies the physical mechanism of antenna failure from a statistical inspection of {approx}75 antennas which ran at the SNS, scanning electron microscopy studies of antenna surface, and cross sectional cuts and analysis of calorimetric heating measurements. Failure mitigation efforts are then described which include modifying the antenna geometry and our acceptance/installation criteria. Progress and status of the development of the SNS external antenna source, a long-term solution to the internal antenna problem, are then discussed. Currently, this source is capable of delivering comparable beam currents to the baseline source to the SNS and, an earlier version, has briefly demonstrated unanalyzed currents up to {approx}100 mA (1 ms, 60 Hz) on the test stand. In particular, this paper discusses plasma ignition (dc and RF plasma guns), antenna reliability, magnet overheating, and insufficient beam persistence.

Welton, Robert F [ORNL; Pennisi, Terry R [ORNL; Roseberry, Ron T [ORNL; Stockli, Martin P [ORNL

2012-01-01

397

Diffusion from a line source  

NASA Technical Reports Server (NTRS)

The problem with predicting pollutant diffusion from a line source of arbitrary geometry is treated. The concentration at the line source may be arbitrarily varied with time. Special attention is given to the meteorological inputs which act as boundary conditions for the problem, and a mixing layer of arbitrary depth is assumed. Numerical application of the derived theory indicates the combinations of meteorological parameters that may be expected to result in high pollution concentrations.

Burns, R. E.

1973-01-01

398

Tracking Sources of CAFO Pollution  

Microsoft Academic Search

Defining the source of pollution is sometimes a contentious affair. Pollution from human sources is readily characterized\\u000a by the presence of the synthetic estrogen, ethinylestradiol. Steroid and sterol profiles are characteristic of different CAFOs,\\u000a e.g. 17? estradiol is typical of cattle, a high ratio of androstenedione\\/testosterone is characteristic of aquaculture. This\\u000a can be combined with the new methods of bacterial

Laurence Shore

399

Radio sources with superluminal velocities  

Microsoft Academic Search

Observed variations concerning the brightness distributions in four extragalactic radio sources were so rapid that the apparent transverse velocity of expansion is greater than the velocity of light. The term superluminal is used to describe this phenomenon. A review is provided of the observations of superluminal expansions. Attention is given to four sources including three quasars (3C345, 3C273, and 3C279)

M. H. Cohen; R. P. Linfield; A. T. Moffet; G. A. Seielstad; K. I. Kellermann; D. B. Shaffer; I. I. K. Pauliny-Toth; E. Preuss; A. Witzel; J. D. Romney; R. T. Schilizzi; B. J. Geldzahler

1977-01-01

400

Special Issue on Light Sources  

Microsoft Academic Search

The papers in this Special Issue of Journal of Physics D: Applied Physics originate from the 11th International Symposium on the Science and Technology of Light Sources (LS:11) held at Fudan University, Shanghai, China, during 20–24 May 2007. Abstracts of all papers were published in the conference book Light Sources 2007 (Sheffield: FAST-LS) edited by Muqing Liu and R Devonshire.

D O Wharmby

2008-01-01

401

Radiation source for helium magnetometers  

NASA Technical Reports Server (NTRS)

A radiation source (12) for optical magnetometers (10) which use helium isotopes as the resonance element (30) includes an electronically pumped semiconductor laser (12) which produces a single narrow line of radiation which is frequency stabilized to the center frequency of the helium resonance line to be optically pumped. The frequency stabilization is accomplished using electronic feedback (34, 40, 42, 44) to control a current sources (20) thus eliminating the need for mechanical frequency tuning.

Slocum, Robert E. (Inventor)

1991-01-01

402

Search for dayside AKR sources  

NASA Astrophysics Data System (ADS)

ABSTRACT Reports concerning observations of dayside Auroral Kilometric Radiation (AKR) sources are very scarce. This contribution presents a search of dayside AKR sources based on analysis of data collected with Polrad swept frequency analyzer during almost 2.5 years of Interball-2 mission. It is based on previous work [1], taking into account the last findings concerning AKR directivity [2]. Arguments for dayside location of some AKR sources are presented and discussed. For a given spacecraft location visibility maps of the part of auroral oval that can host sources seen from that location are constructed in the geomagnetic dipole coordinates. Maps are based on spacecraft-source rectangular coordinates system as defined in [1] and are similar to maps constructed in [2] but do not constrain values of propagation and azimuthal angles to the narrow beams detected in the frame of CLUSTER mission. If such map with maximum propagation angle 90° (no refraction) is fully located on the dayside part of the hemisphere, then AKR source in question should be located on that side too. Delimiting map to regions corresponding to the AKR beams discussed in [2], and especially taking into account beaming in the direction parallel to the auroral oval means smaller potential AKR source region that further strengthens our conclusion. On the other hand fitting lines of constant propagation angle to the lower boundary of the AKR dynamic spectrum makes possible determination of MLT of the source. References [1] Schreiber, R. (2005), A simple model of the auroral kilometric radiation visibility, J.Geophys.Res., 110, A11222, doi:10.1029/2004JA010903. [2] Mutel, R. L., I. W. Christopher, and J. S. Pickett (2008), Cluster multispacecraft determination of AKR angular beaming, Geophys.Res.Lett., 35, L07104, doi:10.1029/2008GL033377.

Schreiber, R.

2008-09-01

403

rf improvements for Spallation Neutron Source H-ion source  

SciTech Connect

The Spallation Neutron Source at Oak Ridge National Laboratory is ramping up the accelerated proton beam power to 1.4 MW and just reached 1 MW. The rf-driven multicusp ion source that originates from the Lawrence Berkeley National Laboratory has been delivering 38 mA H beam in the linac at 60 Hz, 0.9 ms. To improve availability, a rf-driven external antenna multicusp ion source with a water-cooled ceramic aluminum nitride AlN plasma chamber is developed. Computer modeling and simulations have been made to analyze and optimize the rf performance of the new ion source. Operational statistics and test runs with up to 56 mA medium energy beam transport beam current identify the 2 MHz rf system as a limiting factor in the system availability and beam production. Plasma ignition system is under development by using a separate 13 MHz system. To improve the availability of the rf power system with easier maintenance, we tested a 70 kV isolation transformer for the 80 kW, 6% duty cycle 2 MHz amplifier to power the ion source from a grounded solid-state amplifier. 2010 American Institute of Physics.

Kang, Yoon W [ORNL; Fuja, Raymond E [ORNL; Goulding, Richard Howell [ORNL; Hardek, Thomas W [ORNL; Lee, Sung-Woo [ORNL; McCarthy, Mike [ORNL; Piller, Chip [ORNL; Shin, Ki [ORNL; Stockli, Martin P [ORNL; Welton, Robert F [ORNL

2010-01-01

404

Multilevel cascade voltage source inverter with separate DC sources  

DOEpatents

A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations. 15 figs.

Peng, F.Z.; Lai, J.S.

1997-06-24

405

Multilevel cascade voltage source inverter with seperate DC sources  

DOEpatents

A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

Peng, Fang Zheng (Oak Ridge, TN); Lai, Jih-Sheng (Knoxville, TN)

1997-01-01

406

Multilevel cascade voltage source inverter with seperate DC sources  

DOEpatents

A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

Peng, Fang Zheng (Knoxville, TN); Lai, Jih-Sheng (Blacksburg, VA)

2002-01-01

407

Estimating Seismic Source Parameters: Inversions for Source Time Functions  

NASA Astrophysics Data System (ADS)

Quantifying source parameters of earthquakes is fundamental to understanding the physics of earthquake rupture. Researchers commonly estimate parameters such as seismic moment, corner frequency, and stress drop, but variability in estimates is large due to the use of different methods and source models. Most source parameter estimates have been made using frequency-domain model-based methods, and efforts to use both time-domain and non-parametric methods have largely been neglected. We describe a new, non-parametric method for estimating earthquake source time-functions (STF). Our method uses empirical Green's functions and a non-negative least squares inversion in the time domain to compute the STF, and is not complicated by the effects of frequency-domain deconvolution and waterlevel approximations, which are often seen in STF estimates. We further extend our STF estimate to consider the effects of rupture directivity in the seismic source. We estimate the STFs and corresponding scalar parameters (pulse duration and pulse area) for several events recorded at a small aperture array in the San Jacinto Fault Zone (SJFZ) and compare the results obtained at the closely spaced stations to examine the similarity of the estimates. We also compute corner frequency and moment by fitting the spectra for each event to a seismic source model, and we determine how well the estimates match those obtained from the time domain. To test our ability to resolve rupture directivity using the STF estimate, we use records from M5 earthquakes in the SJFZ that have previously been shown to exhibit such directivity. We evaluate how well our estimate of directivity matches those of previous studies and compare the STFs obtained at azimuthally distributed stations.

Kane, D. L.; Prieto, G. A.; Vernon, F. L.; Shearer, P. M.

2008-12-01

408

Production of a radioactive ^76Kr beam using the re-cyclotron method  

NASA Astrophysics Data System (ADS)

Recent interest in g-factor measurements in neutron-deficient 76Kr has stimulated the development of this radioactive beam at the 88-Inch Cyclotron at the Lawrence Berkeley National Laboratory. The 14.8 hour half life allows the production of this beam in a two step-process (Berkeley re-cyclotron method). First, ^76Kr is produced via the reaction ^74Se(,2n) ^76Kr using a 7 particle microampere, 57 MeV alpha beam delivered by the Berkeley 88-Inch Cyclotron. After a production time of one day, approximately 10 ^14 ^76Kr atoms are produced. The activity is then transported via a gas transfer system to a cryogenic trap near the AECR-U ion source. Next, the radioactive atoms are slowly injected into the AECR-U ion source, ionized, and accelerated though the 88-Inch Cyclotron. For ^76Kr ^+15, beam currents as large as one electrical nanoampere, have been observed. The results of recent target and beam development experiments, as well as the integrated beam current, will be presented. This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48.

Cooper, J. R.; Ahle, L.; Bernstein, L.; Punyon, J.; Schiller, A.; Leitner, D.; McMahan, M. A.; Powell, J.; Silver, C.; Benczer-Koller, N.; Hiles, K.; Kumbartzki, G.; Taylor, M. J.; Mertzimekis, T. J.

2003-10-01

409

Infiltration from a strip source  

NASA Astrophysics Data System (ADS)

This study addresses infiltration from strip sources of water on the soil surface. The problem arises as the limiting case of furrow irrigation as well as for closely spaced surface drip emitters. Previously, the most common approach used for describing flow from strip sources was numerical modeling based on Richards' equation. This work investigates a third approach borrowed from previous applications for infiltration from disc sources. The assumption is that when the cumulative infiltration is expressed per unit area of the wetted strip, the difference of that value and one-dimensional infiltration is linear with time. We test the assumption directly by doing numerical experiments with six representative soils and using various strip widths, boundary, and initial water contents. The general conclusions are that the differences between the cumulative infiltration per unit source area for a strip and a planar source are linearly related to time but that a single value of the proportionality factor ? is generally inadequate. Values of ? are found between 0.64 and 1.16. An effort was made to relate ? to soil hydraulic parameters and strip width as well as to the boundary and initial conditions. Once ? is defined, the strip infiltration follows immediately if the corresponding one-dimensional solution is known without the necessity of performing a two-dimensional simulation.

Warrick, A. W.; Lazarovitch, N.

2007-03-01

410

Evaluation of cardiac emboli source  

PubMed Central

Background Evaluating the source of cardiac embolism is one of the most frequent reasons for cardiac consultation. Methods In 2003, 99 patients were referred for the evaluation of the source of cardiac emboli. Evaluation included history, physical examination, ECG, transoesophageal echocardiography (TOE) with contrast and 24-hour Holter electrocardiography. Results Altogether, 58 men and 41 women were studied. In 32 patients a possible source of the cardiac emboli was found. Two patients were in atrial fibrillation. Of the patients, 16 had a patent foramen ovale (PFO) and six patients a PFO and atrial septum aneurysm (ASA). Two patients had a thrombus in the left atrial appendage and 14 had severe atherosclerosis in the aortic arch. In eight patients we found two possible cardiac sources of embolism. 24-hour Holter recording did not detect any emboligenic arrhythmias. Conclusion A possible cardiac source of embolism was found in 32% of the patients referred. TOE is the ideal tool to visualise the interatrial septum, left atrial appendage and aortic arch. We advise performing a TOE with contrast in young stroke patients and in older patients with a stroke likely to be caused by an embolism of cardiac origin. 24-hour Holter recording did not detect any emboligenic arrhythmias and should only be done in selected cases. ImagesFigure 1Figure 2

Michels, M.; Meijboom, F.J.; ten Cate, F.J.

2005-01-01

411

Search for unassociated Fermi sources  

NASA Astrophysics Data System (ADS)

The Fermi Large Area Telescope catalogue 2FGL lists 1872 objects. More than half of them are Active Galatic Nuclei (AGNs) with strong parsec-scale radio emission detectable with VLBI. But 30% of Fermi sources do not have associations and their nature is a mystery. For solving this mystery we launched a project of observing the fields around unassociated sources first with the Australia Telescope Compact Array (ATCA) and the Jansky Very Large Array (VLA) and then following up detected objects with VLBI. This approach allows us to find those gamma-ray sources that are associated with AGNs brighter than 10-20 mJy. Analysis of the completeness of all-sky VLBI surveys shows that the number of bright radio sources with emission from parsec scales is small enough to make the probability of detection of an unrelated object within the Fermi localisation error ellipse negligible. We discuss the status of the program and preliminary results. Early results suggest there exists a population of radio quiet gamma-ray sources not associated with AGNs that show a greater concentration towards the galactic plane.

Petrov, Leonid; Schinzel, F.; Edwards, P.; Mahony, E.; Sadler, E.; McConnell, D.; Taylor, G. B.

2014-01-01

412

Research on fusion neutron sources  

NASA Astrophysics Data System (ADS)

The use of fusion devices as powerful neutron sources has been discussed for decades. Whereas the successful route to a commercial fusion power reactor demands steady state stable operation combined with the high efficiency required to make electricity production economic, the alternative approach to advancing the use of fusion is free of many of complications connected with the requirements for economic power generation and uses the already achieved knowledge of Fusion physics and developed Fusion technologies. ``Fusion for Neutrons'' (F4N), has now been re-visited, inspired by recent progress achieved on comparably compact fusion devices, based on the Spherical Tokamak (ST) concept. Freed from the requirement to produce much more electricity than used to drive it, a fusion neutron source could be efficiently used for many commercial applications, and also to support the goal of producing energy by nuclear power. The possibility to use a small or medium size ST as a powerful or intense steady-state fusion neutron source (FNS) is discussed in this paper in comparison with the use of traditional high aspect ratio tokamaks. An overview of various conceptual designs of compact fusion neutron sources based on the ST concept is given and they are compared with a recently proposed Super Compact Fusion Neutron Source (SCFNS), with major radius as low as 0.5 metres but still able to produce several MW of neutrons in a steady-state regime.

Gryaznevich, M. P.

2012-06-01

413

Research on fusion neutron sources  

SciTech Connect

The use of fusion devices as powerful neutron sources has been discussed for decades. Whereas the successful route to a commercial fusion power reactor demands steady state stable operation combined with the high efficiency required to make electricity production economic, the alternative approach to advancing the use of fusion is free of many of complications connected with the requirements for economic power generation and uses the already achieved knowledge of Fusion physics and developed Fusion technologies. 'Fusion for Neutrons' (F4N), has now been re-visited, inspired by recent progress achieved on comparably compact fusion devices, based on the Spherical Tokamak (ST) concept. Freed from the requirement to produce much more electricity than used to drive it, a fusion neutron source could be efficiently used for many commercial applications, and also to support the goal of producing energy by nuclear power. The possibility to use a small or medium size ST as a powerful or intense steady-state fusion neutron source (FNS) is discussed in this paper in comparison with the use of traditional high aspect ratio tokamaks. An overview of various conceptual designs of compact fusion neutron sources based on the ST concept is given and they are compared with a recently proposed Super Compact Fusion Neutron Source (SCFNS), with major radius as low as 0.5 metres but still able to produce several MW of neutrons in a steady-state regime.

Gryaznevich, M. P. [Tokamak Solutions UK, Culham Science Centre, Abingdon, OXON, OX133DB (United Kingdom)

2012-06-19

414

Low-pressure ion source  

DOEpatents

A low pressure ion source for a neutron source comprises a filament cathode and an anode ring. Approximately 150V is applied between the cathode and the anode. Other electrodes, including a heat shield, a reflector and an aperture plate with a focus electrode, are placed at intermediate potentials. Electrons from the filament drawn out by the plasma and eventually removed by the anode are contained in a magnetic field created by a magnet ring. Ions are formed by electron impact with deuterium or tritium and are extracted at the aperture in the focus electrode. The ion source will typically generate a 200 mA beam through a 1.25 cm/sup 2/ aperture for an arc current of 10A. For deuterium gas, the ion beam is over 50 percent D/sup +/ with less than 1% impurity. The current density profile across the aperture will typically be uniform to within 20%.

Bacon, F.M.; Brainard, J.P.; O'Hagan, J.B.; Walko, R.J.

1982-10-27

415

Miniature x-ray source  

DOEpatents

A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.

Trebes, James E. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA)

2000-01-01

416

Remote Underwater Laser Acoustic Source  

NASA Astrophysics Data System (ADS)

Through the use of nonlinear optical effects, an appropriately tailored laser pulse can propagate relatively long distances underwater at moderate intensity (up to distances on the order of the attenuation length, approximately 10 meters in sea water), then quickly converge to an intense focus within a few centimeters at a controlled location. Optical breakdown can then generate an acoustic pulse at this location. An array of laser-generated acoustic sources could comprise a large acoustic aperture sonar imaging system for locating mines, mapping sea floor topography, or identifying underwater structures. Previous experiments at NRL indicate that approx. 1 mJ of coupled laser energy will produce a 200 dB, microsecond-timescale acoustic pulse, a source level more than adequate for high resolution acoustic imaging applications. A combined experimental and theoretical research program at NRL aims to investigate intense underwater laser propagation and to develop techniques for a remote underwater laser acoustic source. Initial results will be presented.

Jones, T. G.; Ting, A.; Alexeev, I.; Briscoe, E.; Penano, J.; Sprangle, P.

2004-11-01

417

Miniature x-ray source  

DOEpatents

A miniature x-ray source capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature x-ray source comprises a compact vacuum tube assembly containing a cathode, an anode, a high voltage feedthru for delivering high voltage to the anode, a getter for maintaining high vacuum, a connection for an initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is highly x-ray transparent and made, for example, from boron nitride. The compact size and potential for remote operation allows the x-ray source, for example, to be placed adjacent to a material sample undergoing analysis or in proximity to the region to be treated for medical applications.

Trebes, James E. (Livermore, CA); Stone, Gary F. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA); Chornenky, Victor I. (Minnetonka, MN)

2002-01-01

418

High energy synchrotron radiation sources  

SciTech Connect

In the world there are now about 43 laboratories in 16 counties engaged in the operation, construction or planning of electron storage rings, from a few hundred MeV to above 10 GeV, as sources of synchrotron radiation for basic and applied research. In this report we describe the new 3rd generation high energy (i.e.; hard X-ray) sources. The first of these, the 6 GeV European Synchrotron Radiation Facility (ESRF) in Grenoble, France started operation in mid 1992. The 7 GeV Advanced Photon Source (APS) at Argonne, USA and the 8 GeV Super Photon Ring (SPring-8) in Nishi Harima, Japan are expected to start operation for users around 1996--98.

Winick, H.

1993-07-01

419

LIGHT SOURCE: Conceptual design of Hefei advanced light source  

NASA Astrophysics Data System (ADS)

The conceptual of Hefei Advanced Light Source, which is an advanced VUV and Soft X-ray source, was developed at NSRL of USTC. According to the synchrotron radiation user requirements and the trends of SR source development, some accelerator-based schemes were considered and compared; furthermore storage ring with ultra low emittance was adopted as the baseline scheme of HALS. To achieve ultra low emittance, some focusing structures were studied and optimized in the lattice design. Compromising of emittance, on-momentum and off-momentum dynamic aperture and ring scale, five bend acromat (FBA) was employed. In the preliminary design of HALS, the emittance was reduced to sub nm · rad, thus the radiation up to water window has full lateral coherence. The brilliance of undulator radiation covering several eVs to keVs range is higher than that of HLS by several orders. The HALS should be one of the most advanced synchrotron radiation light sources in the world.

Li, Wei-Min; Wang, Lin; Feng, Guang-Yao; Zhang, Shan-Cai; Wu, Cong-Feng; Xu, Hong-Liang; Liu, Zu-Ping

2009-06-01

420

High energy neutrino yields from astrophysical sources. II. Magnetized sources  

SciTech Connect

We calculate the yield of high energy neutrinos produced in astrophysical sources for arbitrary interaction depths {tau}{sub 0} and magnetic field strengths B. We take into account energy loss processes like synchrotron radiation and diffusion of charged particles in turbulent magnetic fields as well as the scattering of secondaries on background photons and the direct production of charm neutrinos. Meson-photon interactions are simulated with an extended version of the SOPHIA model. Diffusion leads to an increased path length before protons leave the source of size R{sub s} and therefore magnetized sources lose their transparency below the energy E{approx}10{sup 18} eV(R{sub s}/pc)(B/mG){tau}{sub 0}{sup 1/{alpha}}, with {alpha}=1/3 and 1 for Kolmogorov and Bohm diffusion, respectively. Moreover, the neutrino flux is suppressed above the energy where synchrotron energy losses become important for charged particles. As a consequence, the energy spectrum and the flavor composition of neutrinos are strongly modified both at low and high energies even for sources with {tau}{sub 0} < or approx. 1.

Kachelriess, M. [Institutt for fysikk, NTNU, N-7491 Trondheim (Norway); Ostapchenko, S. [Institut fuer Experimentelle Kernphysik, Universitaet Karlsruhe, 76021 Karlsruhe (Germany); D. V. Skobeltsyn Institute of Nuclear Physics, Moscow State University, 119992 Moscow (Russian Federation); Tomas, R. [AHEP Group, Institut de Fisica Corpuscular-C.S.I.C./Universitat de Valencia, Edifici Instituts d'Investigacio, Apartado 22085, E-46071 Valencia (Spain)

2008-01-15

421

SOURCE ASSESSMENT: PRIORITIZATION OF STATIONARY WATER POLLUTION SOURCES  

EPA Science Inventory

The report gives priority lists to aid in selecting specific sources of water effluents for detailed assessment. It describes the general water prioritization model, explains its implementation, and gives a detailed example of its use. It describes hazard factors that were develo...

422

The Chandra Source Catalog: Source Properties and Data Products  

Microsoft Academic Search

The Chandra Source Catalog (CSC) is breaking new ground in several areas. There are two aspects that are of particular interest to the users: its evolution and its contents. The CSC will be a living catalog that becomes richer, bigger, and better in time while still remembering its state at each point in time. This means that users will be

Arnold Rots; Ian N. Evans; Kenny J. Glotfelty; Francis A. Primini; Panagoula Zografou; Craig S. Anderson; Nina R. Bonaventura; Judy C. Chen; John E. Davis; Stephen M. Doe; Janet D. Evans; Giuseppina Fabbiano; Elizabeth C. Galle; Danny G. Gibbs II; John D. Grier; Roger Hain; Diane M. Hall; Peter N. Harbo; John C. Houck; Margarita Karovska; Vinay L. Kashyap; Jennifer Lauer; Michael L. McCollough; Jonathan C. McDowell; Joseph B. Miller; Arik W. Mitschang; Douglas L. Morgan; Amy E. Mossman; Joy S. Nichols; Michael A. Nowak; David A. Plummer; Brian L. Refsdal; Aneta L. Siemiginowska; Beth A. Sundheim; Michael S. Tibbetts; David W. van Stone; Sherry L. Winkelman

2009-01-01

423

Distributed Source Coding for Satellite Communications  

Microsoft Academic Search

Inspired by mobile satellite communications systems, we consider a source coding system which consists of multiple sources, multiple encoders, and multiple decoders. Each encoder has access to a certain subset of the sources, each decoder has access to certain subset of the encoders, and each decoder reconstructs a certain subset of the sources almost perfectly. The connectivity between the sources

Raymond W. Yeung; Zhen Zhang

1999-01-01

424

Microbial source tracking: a forensic technique for microbial source identification?  

PubMed

As the requirements of the Water Framework Directive (WFD) and the US Clean Water Act (USCWA) for the maintenance of microbiological water quality in 'protected areas' highlight, there is a growing recognition that integrated management of point and diffuse sources of microbial pollution is essential. New information on catchment microbial dynamics and, in particular, the sources of faecal indicator bacteria found in bathing and shellfish harvesting waters is a pre-requisite for the design of any 'programme of measures' at the drainage basin scale to secure and maintain compliance with existing and new health-based microbiological standards. This paper reports on a catchment-scale microbial source tracking (MST) study in the Leven Estuary drainage basin, northwest England, an area for which quantitative faecal indicator source apportionment empirical data and land use information were also collected. Since previous MST studies have been based on laboratory trials using 'manufactured' samples or analyses of spot environmental samples without the contextual microbial flux data (under high and low flow conditions) and source information, such background data are needed to evaluate the utility of MST in USCWA total maximum daily load (TMDL) assessments or WFD 'Programmes of Measures'. Thus, the operational utility of MST remains in some doubt. The results of this investigation, using genotyping of Bacteroidetes using polymerase chain reaction (PCR) and male-specific ribonucleic acid coliphage (F + RNA coliphage) using hybridisation, suggest some discrimination is possible between livestock- and human-derived faecal indicator concentrations but, in inter-grade areas, the degree to which the tracer picture reflected the land use pattern and probable faecal indicator loading were less distinct. Interestingly, the MST data was more reliable on high flow samples when much of the faecal indicator flux from catchment systems occurs. Whilst a useful supplementary tool, the MST information did not provide quantitative source apportionment for the study catchment. Thus, it could not replace detailed empirical measurement of microbial flux at key catchment outlets to underpin faecal indicator source apportionment. Therefore, the MST techniques reported herein currently may not meet the standards required to be a useful forensic tool, although continued development of the methods and further catchment scale studies could increase confidence in such methods for future application. PMID:17492088

Stapleton, Carl M; Wyer, Mark D; Kay, David; Crowther, John; McDonald, Adrian T; Walters, Martin; Gawler, Andrew; Hindle, Terry

2007-05-01

425

Source counting in MEG neuroimaging  

NASA Astrophysics Data System (ADS)

Magnetoencephalography (MEG) is a multi-channel, functional imaging technique. It measures the magnetic field produced by the primary electric currents inside the brain via a sensor array composed of a large number of superconducting quantum interference devices. The measurements are then used to estimate the locations, strengths, and orientations of these electric currents. This magnetic source imaging technique encompasses a great variety of signal processing and modeling techniques which include Inverse problem, MUltiple SIgnal Classification (MUSIC), Beamforming (BF), and Independent Component Analysis (ICA) method. A key problem with Inverse problem, MUSIC and ICA methods is that the number of sources must be detected a priori. Although BF method scans the source space on a point-to-point basis, the selection of peaks as sources, however, is finally made by subjective thresholding. In practice expert data analysts often select results based on physiological plausibility. This paper presents an eigenstructure approach for the source number detection in MEG neuroimaging. By sorting eigenvalues of the estimated covariance matrix of the acquired MEG data, the measured data space is partitioned into the signal and noise subspaces. The partition is implemented by utilizing information theoretic criteria. The order of the signal subspace gives an estimate of the number of sources. The approach does not refer to any model or hypothesis, hence, is an entirely data-led operation. It possesses clear physical interpretation and efficient computation procedure. The theoretical derivation of this method and the results obtained by using the real MEG data are included to demonstrates their agreement and the promise of the proposed approach.

Lei, Tianhu; Dell, John; Magee, Ralphy; Roberts, Timothy P. L.

2009-02-01

426

The UMLS Knowledge Source server.  

PubMed

The UMLS Knowledge Source server is an evolving tool for accessing information stored in the UMLS Knowledge Sources. The system architecture is based on the client-server paradigm wherein remote site users send their requests to a centrally managed server at the U.S. National Library of Medicine. The client programs can run on platforms supporting the TCP/IP communication protocol. Access to the system is provided through a command-line interface and through an Application Programming Interface. PMID:8591140

McCray, A T; Razi, A

1995-01-01

427

Planetary sources of heliospheric particles  

NASA Astrophysics Data System (ADS)

While the interstellar gas is the generally accepted source of pickup ions in the heliosphere, models suggest that the corotation-driven torus-derived neutral winds of Jupiter and Saturn described by Barbosa and Eviatar (1986) also contribute. These winds are especially important in the inner heliosphere at low latitudes for certain high first ionization potential constituents such as oxygen and nitrogen. Hydrogen from the Titan torus at Saturn and sulfur from the Io torus at Jupiter are also expected to be present. We show how these sources are expected to appear, and discuss how they might be detected in interplanetary spacecraft data.

Luhmann, J. G.

428

The Giessen atomic beam source  

NASA Astrophysics Data System (ADS)

The Giessen Lambshift Source will be converted into an Atomic Beam Source utilizing the existing vacuum system and the Wien Filter. One additional chamber with two turbopumps contains the dissociator, 30 K accommodator, and the first sixpole magnet. Radio frequency transitions are mounted before and after the second multipole magnet for different working modes (single or multiple hyperfinestate selection). Ionization in an ECR discharge and double charge exchange in Cs is used for negative ion production. The atomic beam unit has been optimized successfully in a separate test stand, the actual conversion is scheduled for summer 1993.

Clausnitzer, G.; Baumann, R.; Feuerstein, B.; Flierl, H. P.; Horoi, M.; Keil, G.; Mildner, M.; Ochs, D.; Pfaff, E.; Preiss, M.

1993-12-01

429

Online bibliographic sources in hydrology  

USGS Publications Warehouse

Traditional commercial bibliographic databases and indexes provide some access to hydrology materials produced by the government; however, these sources do not provide comprehensive coverage of relevant hydrologic publications. This paper discusses bibliographic information available from the federal government and state geological surveys, water resources agencies, and depositories. In addition to information in these databases, the paper describes the scope, styles of citing, subject terminology, and the ways these information sources are currently being searched, formally and informally, by hydrologists. Information available from the federal and state agencies and from the state depositories might be missed by limiting searches to commercially distributed databases. ?? 2001 by The Haworth Press, Inc. All rights reserved.].

Wild, E. C.; Michael, Havener, W.

2001-01-01

430

40 CFR Source - Management (Section 319(h))  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Management (Section 319(h)) Source Nonpoint Source Protection of Environment ENVIRONMENTAL PROTECTION...percent of the approved work plan costs. Nonpoint Source-Management (Section 319(h...

2010-07-01

431

Unified Theory for Aerosol Source Apportionment Models.  

National Technical Information Service (NTIS)

A stochastic source apportionment model has been developed with explicitly included random variables to account for the measurement errors in the source and ambient/receptor data, and to simulate the linear source-receptor relationship. Using this model, ...

M. D. Cheng

1986-01-01

432

SOURCE ASSESSMENT: CARBON BLACK MANUFACTURE  

EPA Science Inventory

The report summarizes the assessment of air emissions from the manufacture of carbon black, currently manufactured in the U.S. by two major processes: thermal and oil furnace. Sources of atmospheric emissions within oil furnace plants (about 90% of the 30 U.S. carbon black plants...

433

SUS Source Level Error Analysis.  

National Technical Information Service (NTIS)

The report provides an analysis of major terms which contribute to signal analysis error in a proposed experiment to calibrate source levels of SUS (Signal Underwater Sound). A unique model of the digital signal analysis process was used to verify and emp...

C. I. Holmer

1978-01-01

434

Six Regularities of Source Recognition  

ERIC Educational Resources Information Center

In recent work, researchers have shown that source-recognition memory can be incorporated in an extended signal detection model that covers both it and item-recognition memory (A. Hilford, M. Glanzer, K. Kim, & L. T. DeCarlo, 2002). In 5 experiments, using learning variables that have an established effect on item recognition, the authors tested…

Glanzer, Murray; Hilford, Andy; Kim, Kisok

2004-01-01

435

Latin American Resources, Reference Sources.  

ERIC Educational Resources Information Center

These Latin American reference sources are presented in three independent documents: (1) an annotated bibliography of business and law-related publications, organized by type and subject, including periodicals; (2) a partially annotated bibliography of reference materials in humanities and social sciences; (3) a directory of selected book dealers,…

Schaffer, Ellen G.; And Others

436

Spallation Neutron Source Materials Studies  

Microsoft Academic Search

Operation of accelerator facilities such as Los Alamos Neutron Science Center (LANSCE), ISIS at Rutherford Appleton Laboratory, the Swiss Institute Neutron Source (SINQ) at Paul Scherrer Institute, and others has provided valuable information on materials performance in high energy particle beams and high energy neutron environments. The Accelerator Production of Tritium (APT) project is sponsoring an extensive series of tests

W. F. Sommer

1998-01-01

437

Helicon Sources: Why they work  

Microsoft Academic Search

A helicon source is a cylindrical ceramic tube containing a gas in the milliTorr region immersed in an axial magnet field surrounded at some region by an antenna fed with rf around 10 MHz. As the power is increased it will show a variety of modes characterised by changes in the plasma density. Low power produces a spatially uniform capacitive

Rod Boswell

2007-01-01

438

National Synchrotron Light Source II  

ScienceCinema

The National Synchrotron Light Source II (NSLS-II) at the U.S. Department of Energy's Brookhaven National Laboratory is a proposed new state-of-the-art medium energy storage ring designed to deliver world-leading brightness and flux with top-off operation

439

Redshift Properties of MASIV Sources.  

National Technical Information Service (NTIS)

The MASIV 5 GHz VLA flat-spectrum radio source variability survey of the northern sky has discovered that more than half of its 475 targets exhibited interstellar scintillation (ISS) at one or more of the four survey epochs. We present the first results o...

B. J. Rickett D. L. Jauncey J. E. Lovell R. Ojha T. Pursimo

2010-01-01

440

National Synchrotron Light Source II  

SciTech Connect

The National Synchrotron Light Source II (NSLS-II) at the U.S. Department of Energy's Brookhaven National Laboratory is a proposed new state-of-the-art medium energy storage ring designed to deliver world-leading brightness and flux with top-off operation

Steve Dierker

2008-03-12

441

[Pollution and alternative energy sources].  

PubMed

In order to reach higher standards of living, man has always been interested in searching new energy sources. Natural energy from sun, wind and water has been overcame by more sophisticated resources such as coal, vapour, hydroelectricity, natural gas, petroleum, and, at least, nuclear energy. However all these resources present unwanted effects, namely various hazards to man and environment. On this matter society is quering the risk-benefit balance of some energy choices and optimum performance with new safety means to limit dangerousness are being pursued and developed. It is necessary to evaluate carefully every aspect of safety without under-estimating or over-evaluating problems. For each energy source a "real price" has to be paired, even more in the future, since more energy will be required to guarantee the necessary technological progress linked to a better quality of life. In the present review all risks related to different energy sources are described and discussed aiming at defining: 1) specific risks for different sources 2) benefit from their utilization 3) means of defence guaranteeing security for man and environment. Italy is strictly dependent for energy production, which comes for 80% from abroad. An appropriate balance is required considering economical and social factors and real availability of energy. This balance needs therefore to be clearly evaluated hoping in a better future for an alternative energy, less dangerous and more clear, such as that from nuclear fusion. PMID:2483087

Melino, C

1989-01-01

442

The Source for Asperger's Syndrome.  

ERIC Educational Resources Information Center

This book is intended as a comprehensive source of information on the diagnosis and treatment of Asperger syndrome. Chapter 1 discusses major classification of characteristics and chapter 2 describes prevalence, comorbidity, and causal factors of Asperger syndrome. Chapter 3 examines clinical diagnosis and misdiagnosis and the influence of…

Kowalski, Timothy P.

443

SOURCE MANAGEMENT AND CONTROL TECHNOLOGIES  

EPA Science Inventory

The options for pollution abatement in WWF can be implemented at the source by land management and pollution prevention techniques, in the collection system, offline by storage, or in a treatment plant. An integrated system that combines prevention, control, and treatment has of...

444

Focused X-ray source  

DOEpatents

An intense, relatively inexpensive X-ray source (as compared to a synchrotron emitter) for technological, scientific, and spectroscopic purposes. A conical radiation pattern produced by a single foil or stack of foils is focused by optics to increase the intensity of the radiation at a distance from the conical radiator.

Piestrup, Melvin A. (Woodside, CA); Boyers, David G. (Mountain View, CA); Pincus, Cary I. (Sunnyvale, CA); Maccagno, Pierre (Stanford, CA)

1990-01-01

445

Focused X-ray source  

DOEpatents

Disclosed is an intense, relatively inexpensive X-ray source (as compared to a synchrotron emitter) for technological, scientific, and spectroscopic purposes. A conical radiation pattern produced by a single foil or stack of foils is focused by optics to increase the intensity of the radiation at a distance from the conical radiator. 8 figs.

Piestrup, M.A.; Boyers, D.G.; Pincus, C.I.; Maccagno, P.

1990-08-21

446

Source Equations in Continuum Electromechanics.  

National Technical Information Service (NTIS)

It is shown that the non-conservative balance equation for the linear momentum admits, by a proper choice of the source function which is of single prototype form, all the field equations of continuum electromechanics. They are: the Poisson's equations of...

Z. Karni

1970-01-01

447

Plasma generation and plasma sources  

Microsoft Academic Search

This paper reviews the most commonly used methods for the generation of plasmas with special emphasis on non-thermal, low-temperature plasmas for technological applications. We also discuss various technical realizations of plasma sources for selected applications. This paper is further limited to the discussion of plasma generation methods that employ electric fields. The various plasmas described include dc glow discharges, either

H. Conrads; M. Schmidt

2000-01-01

448

Fast neutron source reactor, YAYOI  

Microsoft Academic Search

The characteristics of the fast neutron source reactor, YAYOI of the University of Tokyo are described. The results of major researches are summarized. Those are the studies of fast neutron shielding and neutron transport, development of standard neutron field, advanced neutron detection, measurement of decay heat, development of epithermal neutron columns for boron neutron capture therapy, on-line tritium recovery from

Y. Oka; S. Koshizuka; I. Saito; K. Okamura; N. Aizawa; N. Sasuga; T. Sukegawa; T. Terakado; Y. Mabuchi; T. Nakagawa; S. An

1998-01-01

449

IDENTIFYING SOURCES OF HUMAN EXPOSURE  

EPA Science Inventory

Air pollution from ambient sources continues to adversely impact human health in the United States. A fundamental goal for EPA is to implement air quality standards and regulations that reduce health risks associated with exposures to criteria pollutants and air toxics. However...

450

Guide to Library Placement Sources.  

ERIC Educational Resources Information Center

This guide updates the listing in the 1976 "Bowker Annual of Library and Book Trade Information" with information on new joblines, new services, and changes in contacts and groups listed. Sources listed primarily give assistance in obtaining professional positions; a few indicate assistance for paraprofessionals, although they are usually…

American Library Association, Chicago, IL.

451

Source Code Exploration with Google  

Microsoft Academic Search

The paper presents a new approach to source code exploration, which is the result of integrating the Google Desktop Search (GDS) engine into the Eclipse development environment. The resulting search engine, named Google Eclipse Search (GES), provides improved searching in Eclipse software projects. The paper advocates for a component-based approach that allows us to develop strong tools, which support various

Denys Poshyvanyk; Maksym Petrenko; Andrian Marcus; Xinrong Xie; Dapeng Liu

2006-01-01

452

Perspectives on Open Source Software.  

National Technical Information Service (NTIS)

Open source software (OSS) is emerging as the software community's next 'silver bullet' and appears to be playing a significant role in the acquisition and development plans of the Department of Defense (DoD) and industry. Yet, as with all previous silver...

S. Hissam C. B. Weinstock D. Plakosh J. Asundi

2001-01-01

453

History Sources on the Internet.  

ERIC Educational Resources Information Center

This paper provides descriptions of key online history resources useful to teachers, librarians, and other education professionals. Highlights include: primary sources on the Internet; archives; Online Public Access Catalogs (OPACs); the American Historical Association (AHA) Web site; state and federal government resources; business history…

Fink, Kenneth D.

454

Buildings As Secondary Seismic Sources  

Microsoft Academic Search

At the scale of a city, surface structures like buildings can modify the seismic free- field and behave as secondary seismic sources. At a local scale, some experimental evidences of the site-structure interaction were previously given (Guéguen, 2000). Thanks to the boundary element method, the global problem of site-city interaction is herein investigated in two dimensions at the scale of

J.-F. Semblat; M. Kham; P. Guéguen; P.-Y. Bard

2002-01-01

455

Alternate Energy Sources for Hawaii.  

National Technical Information Service (NTIS)

This is a report of the Committee on Alternate Energy Sources for Hawaii, which was established by the Governor's State Advisory Task Force on Energy Policy to help respond to problems created by the Arab oil embargo. Fourteen studies were undertaken -- t...

1975-01-01

456

MIT-Bates Polarized Source  

NASA Astrophysics Data System (ADS)

During the fall of 2001, the polarized source at MIT delivered over 140 Coulombs of high quality polarized beams to the SAMPLE-III 125 MeV parity violating experiment. Prior to the experiment, the source was reconfigured to deliver highly polarized beam using the new high power diode array laser system with large aperture beam optics, and a strained layer GaAsP photocathode from St. Petersburg. The results of these tests will be presented. The production run for SAMPLE-III was then carried out with a bulk GaAs and the Ar-Ti:Sapphire laser system. Since April of this year, the source has been delivering high polarization beams to the South Hall Ring for commissioning of the BLAST spectrometer. The stored current in the ring exceeds 100 mA. This is accomplished using the high power diode laser system and high-gradient-doped strained GaAsP photocathodes from Bandwidth Semiconductor Inc. tuned for 810 nm. The operational lifetime of the photocathode is excellent. A status report of the Bates polarized source and the operational experience of delivering high polarization beam to SHR will be presented.

Farkhondeh, M.; Franklin, W.; Tsentalovich, E.; Zwart, T.; Ihloff, E.

2003-07-01

457

FORTRAN Static Source Code Analyzer  

NASA Technical Reports Server (NTRS)

FORTRAN Static Source Code Analyzer program, SAP (DEC VAX version), automatically gathers statistics on occurrences of statements and structures within FORTRAN program and provides reports of those statistics. Provisions made for weighting each statistic and provide an overall figure of complexity.

Merwarth, P.

1984-01-01

458

Primary Sources and Inquiry Learning  

ERIC Educational Resources Information Center

In this article, the author discusses inquiry learning and primary sources. Inquiry learning puts students in the active role of investigators. Questioning, authentic and active learning, and interactivity are a few of the characteristics of inquiry learning that put the teacher and library media specialist in the role of coaches while students…

Pappas, Marjorie L.

2006-01-01

459

High Power Microwave Source Development.  

National Technical Information Service (NTIS)

The requirements of this project have been to: (1) improve and expand the sources available in the facility for testing purposes, and (2) perform specific tasks under direction of DNA about the applications of HPM. In the previous program many such tasks ...

J. N. Benford G. Miller S. Potter S. Ashby R. R. Smith

1995-01-01

460

SOURCE ASSESSMENT: ASPHALT HOT MIX  

EPA Science Inventory

This report summarizes data on air emissions from the asphalt hot mix industry. A representative asphalt hot mix plant was defined, based on the results of an industrial survey, to assess the severity of emissions from this industry. Source severity was defined as the ratio of th...

461

SPORE Award: Open Source Physics  

NSDL National Science Digital Library

Science essay describing the work of the Open Source Physics Project published in conjunction with the AAAS awarding the OSP Project a Science Prize for Online Resources in Education (SPORE) for its development of online tools that bring interactive computer-based modeling to students at many levels.

Christian, Wolfgang; Franciscouembre; Barbato, Lyle

2011-12-09

462

Information Sources on Rural Recycling.  

ERIC Educational Resources Information Center

Provides resources for rural recycling operations with the principle aim of assisting rural government officials, planners, residents, and educators to encourage recycling as an integral part of an individual's or community's solid waste management plan. Sources range from bibliographies, directories, and government documents to case studies. (49…

Notess, Greg; Kuske, Jodee

1992-01-01

463

Jewish Women's Studies: Selected Sources.  

ERIC Educational Resources Information Center

Included in this annotated bibliography are over 150 books, chapters in books, and journal articles dealing with Jewish women and Jewish feminism. Only English language sources have been cited, and the majority of titles focus on the experience of Jewish women in the United States. Most of the items included were published in the 1970's and…

Loeb, Catherine, Comp.

464

Nuclear-pumped flashlamp sources  

Microsoft Academic Search

Due to pump source restrictions, Nuclear-Pumped Lasers (NPLs) typically have relatively long (micro- to milli-second) pulse lengths with only modest peak powers but with very high total energy. These pump power restraints seriously limit the choice of laser media. One way to avoid this problem is to employ a Nuclear Driven Flashlamp (NDF) for the primary pumped element in the

George H. Miley; Mark A. Prelas

2000-01-01

465

National Synchrotron Light Source II  

ScienceCinema

The National Synchrotron Light Source II (NSLS-II) at the U.S. Department of Energy's Brookhaven National Laboratory is a proposed new state-of-the-art medium energy storage ring designed to deliver world-leading brightness and flux with top-off operation

Steve Dierker

2010-01-08

466

Sources of Consumer Education Resources  

ERIC Educational Resources Information Center

Lists publications issued by the federal government, universities, and commercial sources on consumer education with ordering information and prices. Subjects include foods, water conservation, money management, and auto defects, as well as general consumerism. Some of the materials contain lesson ideas and teaching activities. (MF)

Illinois Teacher of Home Economics, 1978

1978-01-01

467

Sources of Variation in Interlanguage.  

ERIC Educational Resources Information Center

Discusses variation in interlanguage and suggests two hypotheses to explain such variation as multiple internal representations of a form and processing errors. Suggests that second language learners can initially represent new forms as prototype schemas, and that such non-discrete representations are a third source of variation in interlanguage.…

Adamson, H. D.; Elliott, Otis Phillip, Jr.

1997-01-01

468

Ferromagnetic Enhanced Inductive Plasma Sources  

NASA Astrophysics Data System (ADS)

Inductively Coupled Plasma, ICP sources, or inductive discharges have been known for over a century. They have been used and studied in past decades mostly in two quite different regimes. At nearly atmospheric pressure, ICPs produce near equilibrium plasmas, while at low gas pressure, in the range of fraction and hundreds of mTorr, ICPs produce highly nonequilibrium plasmas. Low pressure ICPs have been used as ion sources for particle accelerators and thrusters for space propulsion. Recently, interest in low pressure ICPs has been revitalized due to their great advantages in plasma processing and lighting technology. The absence of electrodes, and the capability to provide large plasma densities, and high power transfer efficiency have made these discharges attractive for development of new technologies in various fields. The subject of this presentation is a review of ICP sources enhanced with a ferromagnetic core, FMICP, which found applications in plasma fusion, space propulsion, light sources, plasma chemistry and plasma processing of materials. Introduction of a ferromagnetic core to a magnetic rf circuit of ICP makes its operation close to that of an ideal transformer, thus enhancing its efficiency and power factor. The latter considerably simplifies ICP matching to a rf source. Application of a ferromagnetic core allows for considerable reduction of ICP driving frequency (up to 2-3 orders of magnitude) comparing to the standard in industry of 13.56 MHz. Reduction of the driving frequency allows for practical elimination of capacitive coupling and transmission line effects, inherent to ICP operating at 13.56 MHz. Utilization of lower frequencies also results in more efficient and less expensive rf power sources. However, the most valuable feature of FMICP for plasma processing is its ability for local rf power injection, which promises new possibilities in uniform processing over large substrate areas. The electrical and plasma characteristics of FMICPs, their matching to rf power sources, and their comparison with corresponding characteristics of conventional ICPs without a ferromagnetic core will be discussed in this review for various applications.

Godyak, Valery

2012-10-01

469

The Chandra Source Catalog: User Interface  

NASA Astrophysics Data System (ADS)

The Chandra Source Catalog (CSC) is the definitive catalog of all X-ray sources detected by Chandra. The CSC is presented to the user in two tables: the Master Chandra Source Table and the Table of Individual Source Observations. Each distinct X-ray source identified in the CSC is represented by a single master source entry and one or more individual source entries. If a source is unaffected by confusion and pile-up in multiple observations, the individual source observations are merged to produce a master source. In each table, a row represents a source, and each column a quantity that is officially part of the catalog. The CSC contains positions and multi-band fluxes for the sources, as well as derived spatial, spectral, and temporal source properties. The CSC also includes associated source region and full-field data products for each source, including images, photon event lists, light curves, and spectra. The master source properties represent the best estimates of the properties of a source, and are presented in the following categories: Position and Position Errors, Source Flags, Source Extent and Errors, Source Fluxes, Source Significance, Spectral Properties, and Source Variability. The CSC Data Access GUI provides direct access to the source properties and data products contained in the catalog. The user may query the catalog database via a web-style search or an SQL command-line query. Each query returns a table of source properties, along with the option to browse and download associated data products. The GUI is designed to run in a web browser with Java version 1.5 or higher, and may be accessed via a link on the CSC website homepage (http://cxc.harvard.edu/csc/). As an alternative to the GUI, the contents of the CSC may be accessed directly through a URL, using the command-line tool, cURL. Support: NASA contract NAS8-03060 (CXC).

Bonaventura, Nina; Evans, I. N.; Harbo, P. N.; Rots, A. H.; Tibbetts, M. S.; Van Stone, D. W.; Zografou, P.; Anderson, C. S.; Chen, J. C.; Davis, J. E.; Doe, S. M.; Evans, J. D.; Fabbiano, G.; Galle, E.; Gibbs, D. G.; Glotfelty, K. J.; Grier, J. D.; Hain, R.; Hall, D. M.; He, X.; Houck, J. C.; Karovska, M.; Lauer, J.; McCollough, M. L.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Nichols, J. S.; Nowak, M. A.; Plummer, D. A.; Primini, F. A.; Refsdal, B. L.; Siemiginowska, A. L.; Sundheim, B. A.; Winkelman, S. L.

2009-01-01

470

Z-source inverter for UPS application  

Microsoft Academic Search

This project proposes an impedance-source inverter and its control method for implementing dc-to-ac, ac-to-dc, ac-to-ac, and dc-to-dc power conversion. The Z-source converter employs a unique impedance network to couple the converter main circuit to the power source. The Z-source converter overcomes the conceptual and theoretical barriers and limitations of the traditional voltage-source converter and current-source converter and provides a novel

R. Senthilkumar; R. Bharanikumar; J. Jerom

2007-01-01

471

Implementation of transparent sources in FDTD simulations  

Microsoft Academic Search

Sources can be embedded in a finite-difference time-domain (FDTD) grid in any one of several ways. Depending on the particular implementation, the embedded source corresponds physically to a hard field source (applied field), a transparent current source (impressed current), a finite-impedance voltage source, or some other physical excitation. While the implementation of any of these sources is a straightforward procedure

John B. Schneider; Christopher L. Wagner; Omar M. Ramahi

1998-01-01

472

Source positions time series generation and analysis  

NASA Astrophysics Data System (ADS)

Time series for more than 600 sources were calculated with using QUASAR software from VLBI data processing. Source positions for every sources were obtained from single series analysis by two ways - with fixed coordinates of all another sources with and without EOP estimation.Time series analysis is performed with covariation analysis technique. The attempt was made to propose the parameter which can be used for selection of stable and unstable sources from analysis of source positions time series.

Kurdubov, S. L.; Skurikhina, E.

2008-04-01

473

CW 8X ion source development  

Microsoft Academic Search

Using the 4X source performance and the Penning SPS scaling laws, we predicted the performance of the 8X source. A pulsed 8X source was then built and tested. After verifying the pulsed 8X source operation, especially the H- beam current, emittance, and power efficiency, we designed and built the CW 8X source. We plan to operate the source arc at

H. Vernon Smith; Paul Allison; Carl Geisik; Stuart D. Orbesen; David R. Schmitt; J. David Schneider; James E. Stelzer; Bruce Abel; Irwin Birnbaum; Ron Heuer; Jim Porter; Joe Sredniawski

1992-01-01

474

Texas Intense Positron Source (TIPS)  

NASA Astrophysics Data System (ADS)

The Texas Intense Positron Source (TIPS) is a state of the art variable energy positron beam under construction at the Nuclear Engineering Teaching Laboratory (NETL). Projected intensities on the order of the order of 10^7 e+/second using ^64Cu as the positron source are expected. Owing to is short half-life (t1/2 12.8 hrs), plans are to produce the ^64Cu isotope on-site using beam port 1 of NETL TRIGA Mark II reactor. Following tungsten moderation, the positrons will be electrostatically focused and accelerated from few 10's of eV up to 30 keV. This intensity and energy range should allow routine performance of several analytical techniques of interest to surface scientists (PALS, PADB and perhaps PAES and LEPD.) The TIPS project is being developed in parallel phases. Phase I of the project entails construction of the vacuum system, source chamber, main beam line, electrostatic/magnetic focusing and transport system as well as moderator design. Initial construction, testing and characterization of moderator and beam transport elements are underway and will use a commercially available 10 mCi ^22Na radioisotope as a source of positrons. Phase II of the project is concerned primarily with the Cu source geometry and thermal properties as well as production and physical handling of the radioisotope. Additional instrument optimizing based upon experience gained during Phase I will be incorporated in the final design. Current progress of both phases will be presented along with motivations and future directions.

O'Kelly, D.

2003-03-01

475

Ion source antenna development for the Spallation Neutron Source  

Microsoft Academic Search

The operational lifetime of a radio-frequency (rf) ion source is generally governed by the length of time the insulating structure protecting the antenna survives during exposure to the plasma. Coating the antenna with a thin layer of insulating material is a common means of extending the life of such antennas. When low-power\\/low-duty factor rf excitation is employed, antenna lifetimes of

R. F. Welton; M. P. Stockli; Y. Kang; M. Janney; R. Keller; R. W. Thomae; T. Schenkel; S. Shukla

2002-01-01

476

A New Trellis Source Code for Memoryless Sources  

Microsoft Academic Search

The trellis-based scalar-vector quantizer (TB-SVQ) for memoryless sources combines the scalar-vector quantizer (SVQ) with trellis coded quantization (TCQ) to achieve both boundary gain and granular gain. The resulting quantizer outperforms all other reasonable complexity fixed-rate quantizers. Unfortunately, the resulting code is catastrophic-a single bit error within a block can propagate indefinitely into other blocks. This correspondence presents a new trellis

Liuyang Yang; Thomas R. Fischer

1998-01-01

477

PERSPECTIVE: Dust, fertilization and sources  

NASA Astrophysics Data System (ADS)

Aerosols, tiny suspended particles in the atmosphere, play an important role in modifying the Earth's energy balance and are essential for the formation of cloud droplets. Suspended dust particles lifted from the world's arid regions by strong winds contain essential minerals that can be transported great distances and deposited into the ocean or on other continents where productivity is limited by lack of usable minerals [1]. Dust can transport pathogens as well as minerals great distance, contributing to the spread of human and agricultural diseases, and a portion of dust can be attributed to human activity suggesting that dust radiative effects should be included in estimates of anthropogenic climate forcing. The greenish and brownish tints in figure 1 show the wide extent of monthly mean mineral dust transport, as viewed by the MODerate resolution Imaging Spectroradiometer (MODIS) satellite sensor. The monthly mean global aerosol system for February 2006 from the MODIS aboard the Terra satellite Figure 1. The monthly mean global aerosol system for February 2006 from the MODIS aboard the Terra satellite. The brighter the color, the greater the aerosol loading. Red and reddish tints indicate aerosol dominated by small particles created primarily from combustion processes. Green and brownish tints indicate larger particles created from wind-driven processes, usually transported desert dust. Note the bright green band at the southern edge of the Saharan desert, the reddish band it must cross if transported to the southwest and the long brownish transport path as it crosses the Atlantic to South America. Image courtesy of the NASA Earth Observatory (http://earthobservatory.nasa.gov). Even though qualitatively we recognize the extent and importance of dust transport and the role that it plays in fertilizing nutrient-limited regions, there is much that is still unknown. We are just now beginning to quantify the amount of dust that exits one continental region and the fraction that arrives at another continent [2]. At the deposition end of the chain, it is still unclear how the limited minerals in the dust such as iron are released for uptake by organisms either on land or in the ocean. Not all dust deposited into oceans results in a phytoplankton bloom. The process requires a chemical pathway that mobilizes a fraction of the iron into soluble form. Meskhidze et al [3] show that phytoplankton blooms following dust transport from the Gobi desert in Asia into the Pacific ocean result in a phytoplankton bloom only if the dust is accompanied by high initial SO2-to-dust ratios, suggesting that sulfuric acid coatings on the dust particle mobilize the embedded iron in the dust for phytoplankton uptake. Quantifying transport, deposition and nutrient availability are the latter ends of a puzzle that must begin by identifying and quantifying dust emission at the sources. The emission process is complex at the microscale requiring the right conditions for saltation and bombardment, which makes identification and inclusion of sources in global transport models very difficult. The result is that estimates of annual global dust emissions range from 1000 to 3000 Tg per year [4]. Even as global estimates of dust emissions are uncertain, localizing the sources brings even greater uncertainty. It has been recognized for several years that dust sources are not uniformly distributed over the arid regions of the Earth, but are regulated to topographic lows associated with dried lake deposits [5]. Using aerosol information from satellites, a comprehensive map of the world's source regions shows sources localized to specific areas of the Earth's arid regions [6]. Still these maps suggest broad emission sources covering several degrees of latitude and longitude. In the paper by Koren and co-authors [7] appearing in this issue, one particular dust source, the Bodélé depression in Chad, is analyzed in detail. They find that the specific topography of the depression combined with the prevailing wind direction in the winter provides perfect condition

Remer, Lorraine A.

2006-11-01

478

Sources on US Naval History  

NSDL National Science Digital Library

Hoping to facilitate more new research in its extensive holdings on American naval history, the Naval Historical Center has digitized its material, making more than two centuries of archival material readily available to interested parties. The Web site presents an alphabetic listing of every state in the nation, each of which link directly to primary source material on parties and organizations involved in American naval history in any way, whether it be in the form of production, administration, or active military service. Many of the states' listings link to historical societies and other archival resources, each of which call attention to notable maritime holdings in their collections. Beyond the above, Sources on US Naval History also links back to its creator, the Naval Historical Center, which is the historical branch of the Department of the Navy.

2002-01-01

479

High brightness sources for colliders  

SciTech Connect

Different possible sources are considered and the importance of the gun for linear colliders discussed. Low emittance electron guns suitable for SLC are available now and we discuss current work that could also provide high polarization. The relative merits of {rvec {gamma}}, {rvec e}{sup {plus minus}} and {rvec p}{sup {plus minus}} are discussed and how the next linear collider (NLC) naturally provides both {rvec e}{sup {plus minus}} and {rvec {gamma}}. Particular emphasis was placed on stability demands of LC's without sacrificing flexibility. A general purpose, versatile source is described that can collimate and/or tailor the bunch shape. Finally, some interesting experiments for SLC are discussed that could provide good physics while testing such ideas for the next generation machine. At 0.5--1.0 TeV such a machine would be complementary and competitive with LHC. 18 refs., 2 figs., 1 tab.

Spencer, J.E.

1991-05-01

480

An ion source research facility  

SciTech Connect

As an ion source developer, D-Pace frequently faces the issue of needing access to a research facility to be able to test equipment or to develop our existing technology further. The closest facility to perform such tasks is hundreds of kilometers away, at TRIUMF, and it is not always feasible to make use of it on a timely basis. With a growing demand and a desire to enhance our products, the idea to create an ion source research facility in our region evolved. In this paper, we will discuss the approach that was chosen to reach our goal, the status of the project, the principle layout of the facility, and the different ways this facility could be utilized.

Roeder, M.; Dehnel, M.; Jackle, P.; Stewart, T.; Theroux, J. [D-Pace, Inc., P.O. Box 201, Nelson, British Columbia V1L 5P9 (Canada)

2008-02-15

481

An ion source research facility.  

PubMed

As an ion source developer, D-Pace frequently faces the issue of needing access to a research facility to be able to test equipment or to develop our existing technology further. The closest facility to perform such tasks is hundreds of kilometers away, at TRIUMF, and it is not always feasible to make use of it on a timely basis. With a growing demand and a desire to enhance our products, the idea to create an ion source research facility in our region evolved. In this paper, we will discuss the approach that was chosen to reach our goal, the status of the project, the principle layout of the facility, and the different ways this facility could be utilized. PMID:18315134

Roeder, M; Dehnel, M; Jackle, P; Stewart, T; Theroux, J

2008-02-01

482

Waste pyrolysis - Alternative fuel source  

Microsoft Academic Search

Four means for producing alternative fuel sources via waste pyrolysis are considered. In the first, low-Btu gas is produced