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Sample records for pulse duplicator system

  1. Development of a flow feedback pulse duplicator system with rhesus monkey arterial input impedance characteristics.

    PubMed

    Schaub, J D; Koenig, S C; Schroeder, M J; Ewert, D L; Drew, G A; Swope, R D

    1999-01-01

    An in vitro pulsatile pump flow system that is capable of producing physiologic pressures and flows in a mock circulatory system tuned to reproduce the first nine harmonics of the input impedance of a rhesus monkey was developed and tested. The system was created as a research tool for evaluating cardiovascular function and for the design, testing, and evaluation of electrical-mechanical cardiovascular models and chronically implanted sensors. The system possesses a computerized user interface for controlling a linear displacement pulsatile pump in a controlled flow loop format to emulate in vivo cardiovascular characteristics. Evaluation of the pump system consisted of comparing its aortic pressure and flow profiles with in vivo rhesus hemodynamic waveforms in the time and frequency domains. Comparison of aortic pressure and flow data between the pump system and in vivo data showed good agreement in the time and frequency domains, however, the pump system produced a larger pulse pressure. The pump system can be used for comparing cardiovascular parameters with predicted cardiovascular model values and for evaluating such items as vascular grafts, heart valves, biomaterials, and sensors. This article describes the development and evaluation of this feedback controlled cardiovascular dynamics simulation modeling system.

  2. Development of a flow feedback pulse duplicator system with rhesus monkey arterial input impedance characteristics

    NASA Technical Reports Server (NTRS)

    Schaub, J. D.; Koenig, S. C.; Schroeder, M. J.; Ewert, D. L.; Drew, G. A.; Swope, R. D.; Convertino, V. A. (Principal Investigator)

    1999-01-01

    An in vitro pulsatile pump flow system that is capable of producing physiologic pressures and flows in a mock circulatory system tuned to reproduce the first nine harmonics of the input impedance of a rhesus monkey was developed and tested. The system was created as a research tool for evaluating cardiovascular function and for the design, testing, and evaluation of electrical-mechanical cardiovascular models and chronically implanted sensors. The system possesses a computerized user interface for controlling a linear displacement pulsatile pump in a controlled flow loop format to emulate in vivo cardiovascular characteristics. Evaluation of the pump system consisted of comparing its aortic pressure and flow profiles with in vivo rhesus hemodynamic waveforms in the time and frequency domains. Comparison of aortic pressure and flow data between the pump system and in vivo data showed good agreement in the time and frequency domains, however, the pump system produced a larger pulse pressure. The pump system can be used for comparing cardiovascular parameters with predicted cardiovascular model values and for evaluating such items as vascular grafts, heart valves, biomaterials, and sensors. This article describes the development and evaluation of this feedback controlled cardiovascular dynamics simulation modeling system.

  3. Pulse Duplicator Hydrodynamic Testing of Bioengineered Biological Heart Valves.

    PubMed

    Buse, Eric E; Hilbert, Stephen L; Hopkins, Richard A; Converse, Gabriel L

    2016-12-01

    There are many heart valve replacements currently available on the market; however, these devices are not ideal for pediatric patients with congenital heart valve defects. Decellularized valve substitutes offer potential for improved clinical outcomes and require pre-clinical testing guidelines and testing systems suitable for non-crosslinked, biological heart valves. The objective of this study was to assess the hydrodynamic performance of intact, bioengineered pulmonary valves using a custom pulse duplicator capable of testing intact biological valved conduits. The mechanical behavior of valve associated sinus and arterial tissue was also evaluated under biaxial loading. Cryopreserved, decellularized, extracellular matrix (ECM) conditioned and glutaraldehyde fixed valves showed reduced pressure gradients and increased effective orifice area for decellularized and ECM conditioned valves. ECM conditioning resulted in increased elastic modulus but decreased stretch in circumferential and longitudinal directions under biaxial loading. Overall, decellularization and ECM conditioning did not compromise the scaffolds, which exhibited satisfactory bench top performance.

  4. A computerized physiologic pulse duplicator for in-vitro hydrodynamic and ultrasonic studies of prosthetic heart valves.

    PubMed

    Arabia, F A; Talbot, T L; Stewart, S F; Nast, E P; Clark, R E

    1989-01-01

    A physiologic pulse duplicator for the simultaneous in-vitro hydrodynamic and ultrasonic evaluation of aortic prosthetic heart valves is described. The system is interfaced to a personal computer, which provides greater efficiency over manual techniques in system calibration, data acquisition, and analysis. The data analysis program aids selection of start and end systole and calculates pressure difference across the valve, the closing and regurgitant volumes, flow rates, and the Gabbay and Swanson performance indices. The pulse duplicator is designed to accommodate the ultrasonic measurement of fluid velocities, including pressure difference via the Bernoulli equation, and color-flow imaging. In tests of 19-mm, 23-mm, and 27-mm Bjork-Shiley spherical occluder valves, continuous-wave Doppler ultrasound was found to overestimate by about 50% the pressure difference measured directly by pressure transducers, a finding that is clinically important.

  5. Methods, apparatus and system for selective duplication of subtasks

    DOEpatents

    Andrade Costa, Carlos H.; Cher, Chen-Yong; Park, Yoonho; Rosenburg, Bryan S.; Ryu, Kyung D.

    2016-03-29

    A method for selective duplication of subtasks in a high-performance computing system includes: monitoring a health status of one or more nodes in a high-performance computing system, where one or more subtasks of a parallel task execute on the one or more nodes; identifying one or more nodes as having a likelihood of failure which exceeds a first prescribed threshold; selectively duplicating the one or more subtasks that execute on the one or more nodes having a likelihood of failure which exceeds the first prescribed threshold; and notifying a messaging library that one or more subtasks were duplicated.

  6. PULSE SCALING SYSTEM

    DOEpatents

    Kandiah, K.

    1954-06-01

    Pulse scaling systems embodying multi-electrode gaseous-discharge tubes of the type having a plurality of stable discharge paths are described. The novelty of this particular system lies in the simplification of the stepping arrangement between successive tubes. In one form the invention provides a multistage scaler comprising a pulse generator, a first multi-electrode scaling tube of the type set forth coupled to said generator to receive transfer pulses therefrom and one or more succeeding multi-electrode scaling tubes each deriving its transfer pulses from preceding scaling tubes.

  7. Pulsed hall thruster system

    NASA Technical Reports Server (NTRS)

    Hruby, Vladimir J. (Inventor); Pote, Bruce M. (Inventor); Gamero-Castano, Manuel (Inventor)

    2004-01-01

    A pulsed Hall thruster system includes a Hall thruster having an electron source, a magnetic circuit, and a discharge chamber; a power processing unit for firing the Hall thruster to generate a discharge; a propellant storage and delivery system for providing propellant to the discharge chamber and a control unit for defining a pulse duration .tau.<0.1d.sup.3.rho./m, where d is the characteristic size of the thruster, .rho. is the propellant density at standard conditions, and m is the propellant mass flow rate for operating either the power processing unit to provide to the Hall thruster a power pulse of a pre-selected duration, .tau., or operating the propellant storage and delivery system to provide a propellant flow pulse of duration, .tau., or providing both as pulses, synchronized to arrive coincidentally at the discharge chamber to enable the Hall thruster to produce a discreet output impulse.

  8. Pulse to pulse klystron diagnosis system

    SciTech Connect

    Nowak, J.; Davidson, V.; Genova, L.; Johnson, R.; Reagan, D.

    1981-03-01

    This report describes a system used to study the behavior of SLAC high powered klystrons operating with a twice normal pulse width of 5 ..mu..s. At present, up to eight of the klystrons installed along the accelerator can be operated with long pulses and monitored by this system. The report will also discuss some of the recent findings and investigations.

  9. Hybrid chirped pulse amplification system

    DOEpatents

    Barty, Christopher P.; Jovanovic, Igor

    2005-03-29

    A hybrid chirped pulse amplification system wherein a short-pulse oscillator generates an oscillator pulse. The oscillator pulse is stretched to produce a stretched oscillator seed pulse. A pump laser generates a pump laser pulse. The stretched oscillator seed pulse and the pump laser pulse are directed into an optical parametric amplifier producing an optical parametric amplifier output amplified signal pulse and an optical parametric amplifier output unconverted pump pulse. The optical parametric amplifier output amplified signal pulse and the optical parametric amplifier output laser pulse are directed into a laser amplifier producing a laser amplifier output pulse. The laser amplifier output pulse is compressed to produce a recompressed hybrid chirped pulse amplification pulse.

  10. The Duplicate-Replacement System: An Alternative Method of Handling Book Duplicates.

    ERIC Educational Resources Information Center

    Clement, Russell T.

    This report studied the alternative method of using book duplicates as replacement copies for worn or missing stack items. The simple operational procedure which is proposed and evaluated could be adapted to virtually any library setting. When tested in Brigham Young University's Lee Library, it was found that such a procedure cost an estimated…

  11. Pulsed-field electrophoresis screening for immunoglobulin heavy-chain constant-region (IGHC) multigene deletions and duplications.

    PubMed Central

    Bottaro, A; Cariota, U; DeMarchi, M; Carbonara, A O

    1991-01-01

    Genome regions containing multiple copies of homologous genes, such as the immunoglobulin (Ig) heavy-chain constant-region (IGHC) locus, are often unstable and give rise to duplicated and deleted haplotypes. Analysis of such processes is fundamental to understanding the mechanisms of evolution of multigene families. In the IGHC region, a number of single and multiple gene deletions, derived from either unequal crossing-over or looping-out excision, have been described. To study these haplotypes at the population level, a simple and efficient method for preparing large numbers of DNA samples suitable for pulsed-field gel electrophoresis (PFGE) analysis was set up, and a sample of 110 blood donors was screened. Deletions were found to be frequent, as expected on the basis of previous serological surveys for homozygotes. Furthermore, a number of multigene duplications, never identified before, were detected. The total frequency of individuals bearing rearranged IGHC haplotypes was 10%. The genes involved in these deletions and duplications were assessed by densitometric analysis of standard Southern blots hybridized with several IGHC probes; two types of deletion and two types of duplication could thus be characterized. These data provide further evidence of the instability of the IGHC locus and demonstrate that unequal crossing-over is the most likely origin of rearranged IGHC haplotypes; they also suggest that such recombination events may be relatively frequent. Moreover, the simplicity and effectiveness of the large-scale PFGE screening approach will be of great help in the study of multigene families and of other loci involved in aberrant recombinations. Images p[750]-a Figure 2 Figure 3 Figure 5 Figure 6 PMID:1901690

  12. Switching power pulse system

    DOEpatents

    Aaland, K.

    1983-08-09

    A switching system for delivering pulses of power from a source to a load using a storage capacitor charged through a rectifier, and maintained charged to a reference voltage level by a transistor switch and voltage comparator. A thyristor is triggered to discharge the storage capacitor through a saturable reactor and fractional turn saturable transformer having a secondary to primary turn ratio N of n:l/n = n[sup 2]. The saturable reactor functions as a soaker'' while the thyristor reaches saturation, and then switches to a low impedance state. The saturable transformer functions as a switching transformer with high impedance while a load coupling capacitor charges, and then switches to a low impedance state to dump the charge of the storage capacitor into the load through the coupling capacitor. The transformer is comprised of a multilayer core having two secondary windings tightly wound and connected in parallel to add their output voltage and reduce output inductance, and a number of single turn windings connected in parallel at nodes for the primary winding, each single turn winding linking a different one of the layers of the multilayer core. The load may be comprised of a resistive beampipe for a linear particle accelerator and capacitance of a pulse forming network. To hold off discharge of the capacitance until it is fully charged, a saturable core is provided around the resistive beampipe to isolate the beampipe from the capacitance until it is fully charged. 5 figs.

  13. Switching power pulse system

    DOEpatents

    Aaland, Kristian

    1983-01-01

    A switching system for delivering pulses of power from a source (10) to a load (20) using a storage capacitor (C3) charged through a rectifier (D1, D2), and maintained charged to a reference voltage level by a transistor switch (Q1) and voltage comparator (12). A thyristor (22) is triggered to discharge the storage capacitor through a saturable reactor (18) and fractional turn saturable transformer (16) having a secondary to primary turn ratio N of n:l/n=n.sup.2. The saturable reactor (18) functions as a "soaker" while the thyristor reaches saturation, and then switches to a low impedance state. The saturable transformer functions as a switching transformer with high impedance while a load coupling capacitor (C4) charges, and then switches to a low impedance state to dump the charge of the storage capacitor (C3) into the load through the coupling capacitor (C4). The transformer is comprised of a multilayer core (26) having two secondary windings (28, 30) tightly wound and connected in parallel to add their output voltage and reduce output inductance, and a number of single turn windings connected in parallel at nodes (32, 34) for the primary winding, each single turn winding linking a different one of the layers of the multilayer core. The load may be comprised of a resistive beampipe (40) for a linear particle accelerator and capacitance of a pulse forming network (42). To hold off discharge of the capacitance until it is fully charged, a saturable core (44) is provided around the resistive beampipe (40) to isolate the beampipe from the capacitance (42) until it is fully charged.

  14. Evolution of vertebrate central nervous system is accompanied by novel expression changes of duplicate genes.

    PubMed

    Chen, Yuan; Ding, Yun; Zhang, Zuming; Wang, Wen; Chen, Jun-Yuan; Ueno, Naoto; Mao, Bingyu

    2011-12-20

    The evolution of the central nervous system (CNS) is one of the most striking changes during the transition from invertebrates to vertebrates. As a major source of genetic novelties, gene duplication might play an important role in the functional innovation of vertebrate CNS. In this study, we focused on a group of CNS-biased genes that duplicated during early vertebrate evolution. We investigated the tempo-spatial expression patterns of 33 duplicate gene families and their orthologs during the embryonic development of the vertebrate Xenopus laevis and the cephalochordate Brachiostoma belcheri. Almost all the identified duplicate genes are differentially expressed in the CNS in Xenopus embryos, and more than 50% and 30% duplicate genes are expressed in the telencephalon and mid-hindbrain boundary, respectively, which are mostly considered as two innovations in the vertebrate CNS. Interestingly, more than 50% of the amphioxus orthologs do not show apparent expression in the CNS in amphioxus embryos as detected by in situ hybridization, indicating that some of the vertebrate CNS-biased duplicate genes might arise from non-CNS genes in invertebrates. Our data accentuate the functional contribution of gene duplication in the CNS evolution of vertebrate and uncover an invertebrate non-CNS history for some vertebrate CNS-biased duplicate genes. Copyright © 2011. Published by Elsevier Ltd.

  15. Pulsed helium ionization detection system

    DOEpatents

    Ramsey, R.S.; Todd, R.A.

    1985-04-09

    A helium ionization detection system is provided which produces stable operation of a conventional helium ionization detector while providing improved sensitivity and linearity. Stability is improved by applying pulsed dc supply voltage across the ionization detector, thereby modifying the sampling of the detectors output current. A unique pulse generator is used to supply pulsed dc to the detector which has variable width and interval adjust features that allows up to 500 V to be applied in pulse widths ranging from about 150 nsec to about dc conditions.

  16. Pulsed helium ionization detection system

    DOEpatents

    Ramsey, Roswitha S.; Todd, Richard A.

    1987-01-01

    A helium ionization detection system is provided which produces stable operation of a conventional helium ionization detector while providing improved sensitivity and linearity. Stability is improved by applying pulsed dc supply voltage across the ionization detector, thereby modifying the sampling of the detectors output current. A unique pulse generator is used to supply pulsed dc to the detector which has variable width and interval adjust features that allows up to 500 V to be applied in pulse widths ranging from about 150 nsec to about dc conditions.

  17. Pulse shaping system

    DOEpatents

    Skeldon, M.D.; Letzring, S.A.

    1999-03-23

    Temporally shaped electrical waveform generation provides electrical waveforms suitable for driving an electro-optic modulator (EOM) which produces temporally shaped optical laser pulses for inertial confinement fusion (ICF) research. The temporally shaped electrical waveform generation is carried out with aperture coupled transmission lines having an input transmission line and an aperture coupled output transmission line, along which input and output pulses propagate in opposite directions. The output electrical waveforms are shaped principally due to the selection of coupling aperture width, in a direction transverse to the lines, which varies along the length of the line. Specific electrical waveforms, which may be high voltage (up to kilovolt range), are produced and applied to the EOM to produce specifically shaped optical laser pulses. 8 figs.

  18. Pulse shaping system

    DOEpatents

    Skeldon, Mark D.; Letzring, Samuel A.

    1999-03-23

    Temporally shaped electrical waveform generation provides electrical waveforms suitable for driving an electro-optic modulator (EOM) which produces temporally shaped optical laser pulses for inertial confinement fusion (ICF) research. The temporally shaped electrical waveform generation is carried out with aperture coupled transmission lines having an input transmission line and an aperture coupled output transmission line, along which input and output pulses propagate in opposite directions. The output electrical waveforms are shaped principally due to the selection of coupling aperture width, in a direction transverse to the lines, which varies along the length of the line. Specific electrical waveforms, which may be high voltage (up to kilovolt range), are produced and applied to the EOM to produce specifically shaped optical laser pulses.

  19. Nested radiations and the pulse of angiosperm diversification: increased diversification rates often follow whole genome duplications.

    PubMed

    Tank, David C; Eastman, Jonathan M; Pennell, Matthew W; Soltis, Pamela S; Soltis, Douglas E; Hinchliff, Cody E; Brown, Joseph W; Sessa, Emily B; Harmon, Luke J

    2015-07-01

    Our growing understanding of the plant tree of life provides a novel opportunity to uncover the major drivers of angiosperm diversity. Using a time-calibrated phylogeny, we characterized hot and cold spots of lineage diversification across the angiosperm tree of life by modeling evolutionary diversification using stepwise AIC (MEDUSA). We also tested the whole-genome duplication (WGD) radiation lag-time model, which postulates that increases in diversification tend to lag behind established WGD events. Diversification rates have been incredibly heterogeneous throughout the evolutionary history of angiosperms and reveal a pattern of 'nested radiations' - increases in net diversification nested within other radiations. This pattern in turn generates a negative relationship between clade age and diversity across both families and orders. We suggest that stochastically changing diversification rates across the phylogeny explain these patterns. Finally, we demonstrate significant statistical support for the WGD radiation lag-time model. Across angiosperms, nested shifts in diversification led to an overall increasing rate of net diversification and declining relative extinction rates through time. These diversification shifts are only rarely perfectly associated with WGD events, but commonly follow them after a lag period. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  20. Pulse-width tunable multi-channel NRZ-to-RZ conversion with duplicate output

    NASA Astrophysics Data System (ADS)

    Yu, Yu; Zhang, Xinliang; Huang, Dexiu

    2012-01-01

    We demonstrate multi-channel non-return-to-zero (NRZ) to return-to-zero (RZ) conversions with tunable output pulse-width and single-to-dual function, using a phase modulator and an array waveguide grating (AWG), which acts both detuned multi-channel filter and demultiplexer. Four-channel NRZ signals after transmission can be converted to eight-channel RZ signals with timing jitter and extinction ratio improvement. Further transmission and bit error ratio (BER) measurements for the converted RZ signal show a good performance compared with conventional one.

  1. NASAwide electronic publishing system: Electronic printing and duplicating, stage-2 evaluation report (GSFC)

    NASA Technical Reports Server (NTRS)

    Tuey, Richard C.; Lane, Robert; Hart, Susan V.

    1995-01-01

    The NASA Scientific and Technical Information Office was assigned the responsibility to continue with the expansion of the NASAwide networked electronic duplicating effort by including the Goddard Space Flight Center (GSFC) as an additional node to the existing configuration of networked electronic duplicating systems within NASA. The subject of this report is the evaluation of a networked electronic duplicating system which meets the duplicating requirements and expands electronic publishing capabilities without increasing current operating costs. This report continues the evaluation reported in 'NASA Electronic Publishing System - Electronic Printing and Duplicating Evaluation Report' (NASA TM-106242) and 'NASA Electronic Publishing System - Stage 1 Evaluation Report' (NASA TM-106510). This report differs from the previous reports through the inclusion of an external networked desktop editing, archival, and publishing functionality which did not exist with the previous networked electronic duplicating system. Additionally, a two-phase approach to the evaluation was undertaken; the first was a paper study justifying a 90-day, on-site evaluation, and the second phase was to validate, during the 90-day evaluation, the cost benefits and productivity increases that could be achieved in an operational mode. A benchmark of the functionality of the networked electronic publishing system and external networked desktop editing, archival, and publishing system was performed under a simulated daily production environment. This report can be used to guide others in determining the most cost effective duplicating/publishing alternative through the use of cost/benefit analysis and return on investment techniques. A treatise on the use of these techniques can be found by referring to 'NASA Electronic Publishing System -Cost/Benefit Methodology' (NASA TM-106662).

  2. Pulsed ultrasonic stir welding system

    NASA Technical Reports Server (NTRS)

    Ding, R. Jeffrey (Inventor)

    2013-01-01

    An ultrasonic stir welding system includes a welding head assembly having a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. During a welding operation, ultrasonic pulses are applied to the rod as it rotates about its longitudinal axis. The ultrasonic pulses are applied in such a way that they propagate parallel to the longitudinal axis of the rod.

  3. Generation of Duplicated Off-Line Signature Images for Verification Systems.

    PubMed

    Diaz, Moises; Ferrer, Miguel A; Eskander, George S; Sabourin, Robert

    2017-05-01

    Biometric researchers have historically seen signature duplication as a procedure relevant to improving the performance of automatic signature verifiers. Different approaches have been proposed to duplicate dynamic signatures based on the heuristic affine transformation, nonlinear distortion and the kinematic model of the motor system. The literature on static signature duplication is limited and as far as we know based on heuristic affine transforms and does not seem to consider the recent advances in human behavior modeling of neuroscience. This paper tries to fill this gap by proposing a cognitive inspired algorithm to duplicate off-line signatures. The algorithm is based on a set of nonlinear and linear transformations which simulate the human spatial cognitive map and motor system intra-personal variability during the signing process. The duplicator is evaluated by increasing artificially a training sequence and verifying that the performance of four state-of-the-art off-line signature classifiers using two publicly databases have been improved on average as if we had collected three more real signatures.

  4. NASA wide electronic publishing system: Electronic printing and duplicating. Stage 3 evaluation report

    NASA Technical Reports Server (NTRS)

    Tuey, Richard C.; Moore, Fred W.; Ryan, Christine A.

    1995-01-01

    The report is presented in four sections: The Introduction describes the duplicating configuration under evaluation and the Background contains a chronological description of the evaluation segmented by phases 1 and 2. This section includes the evaluation schedule, printing and duplicating requirements, storage and communication requirements, electronic publishing system configuration, existing processes and proposed processes, billing rates, costs and productivity analysis, and the return on investment based upon the data gathered to date. The third section contains the phase 1 comparative cost and productivity analysis. This analysis demonstrated that LaRC should proceed with a 90-day evaluation of the DocuTech and follow with a phase 2 cycle to actually demonstrate that the proposed system would meet the needs of LaRC's printing and duplicating requirements, benchmark results, cost comparisons, benchmark observations, and recommendations. These are documented after the recommendations.

  5. Pulse-Flow Microencapsulation System

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R.

    2006-01-01

    The pulse-flow microencapsulation system (PFMS) is an automated system that continuously produces a stream of liquid-filled microcapsules for delivery of therapeutic agents to target tissues. Prior microencapsulation systems have relied on batch processes that involve transfer of batches between different apparatuses for different stages of production followed by sampling for acquisition of quality-control data, including measurements of size. In contrast, the PFMS is a single, microprocessor-controlled system that performs all processing steps, including acquisition of quality-control data. The quality-control data can be used as real-time feedback to ensure the production of large quantities of uniform microcapsules.

  6. Magnetic resonance urography in evaluation of duplicated renal collecting systems.

    PubMed

    Adeb, Melkamu; Darge, Kassa; Dillman, Jonathan R; Carr, Michael; Epelman, Monica

    2013-11-01

    Duplex renal collecting systems are common congenital anomalies of the upper urinary tract. In most cases they are incidental findings and not associated with additional pathologies. They demonstrate, however, higher incidences of hydroureteronephrosis, ureteroceles, and ectopic ureters. The most comprehensive morphologic and functional evaluation of duplex systems can be achieved using magnetic resonance urography. Functional magnetic resonance urography allows better separation of the renal poles, thus more accurate calculation of the differential renal functions compared with renal scintigraphy. Magnetic resonance urography is the study of choice when upper urinary tract anatomy is complex or when functional evaluation is needed.

  7. Efficient optical pulse stacker system

    DOEpatents

    Seppala, Lynn G.; Haas, Roger A.

    1982-01-01

    Method and apparatus for spreading and angle-encoding each pulse of a multiplicity of small area, short pulses into several temporally staggered pulses by use of appropriate beam splitters, with the optical elements being arranged so that each staggered pulse is contiguous with one or two other such pulses, and the entire sequence of stacked pulses comprising a single, continuous long pulse. The single long pulse is expanded in area, and then doubly passed through a nonstorage laser amplifier such as KrF. After amplification, the physically separated, angle-encoded and temporally staggered pulses are recombined into a single pulse of short duration. This high intensity output beam is well collimated and may be propagated over long distance, or used for irradiating inertial confinement fusion targets.

  8. Pulse shaping on the Nova laser system

    SciTech Connect

    Lawson, J.K.; Speck, D.R.; Bibeau, C.; Weiland, T.L.

    1989-02-06

    Inertial confinement fusion requires temporally shaped pulses to achieve high gain efficiency. Recently, we demonstrated the ability to produce complex temporal pulse shapes at high power at 0.35 microns on the Nova laser system. 2 refs., 2 figs.

  9. Dispersion compensation in chirped pulse amplification systems

    DOEpatents

    Bayramian, Andrew James; Molander, William A.

    2014-07-15

    A chirped pulse amplification system includes a laser source providing an input laser pulse along an optical path. The input laser pulse is characterized by a first temporal duration. The system also includes a multi-pass pulse stretcher disposed along the optical path. The multi-pass pulse stretcher includes a first set of mirrors operable to receive input light in a first plane and output light in a second plane parallel to the first plane and a first diffraction grating. The pulse stretcher also includes a second set of mirrors operable to receive light diffracted from the first diffraction grating and a second diffraction grating. The pulse stretcher further includes a reflective element operable to reflect light diffracted from the second diffraction grating. The system further includes an amplifier, a pulse compressor, and a passive dispersion compensator disposed along the optical path.

  10. Recurrent urinary tract infections in an adult with a duplicated renal collecting system.

    PubMed

    Raja, Junaid; Mohareb, Amir M; Bilori, Bilori

    2016-12-01

    Because of advancements in fetal imaging, anatomic variants of the genitourinary tract are most often discovered in the antenatal period. As such, general internists are less likely to encounter adult patients with previously undiagnosed anatomic abnormalities of the renal collecting system, such as duplicated kidneys. These abnormalities put patients at risk for urinary obstruction and recurrent infections of the urinary tract. We report the case of a 40-year-old diabetic patient with a previously undiagnosed duplex kidney who had recurrent episodes of diabetic ketoacidosis triggered by urinary tract infections. She was ultimately found to have abscess formation in the duplicated renal moiety. We reviewed the epidemiology, diagnosis, and management of duplex kidneys. We also reviewed the indications for renal imaging in adult patients with similar clinical presentations.

  11. A study of new pulse auscultation system.

    PubMed

    Chen, Ying-Yun; Chang, Rong-Seng

    2015-04-14

    This study presents a new type of pulse auscultation system, which uses a condenser microphone to measure pulse sound waves on the wrist, captures the microphone signal for filtering, amplifies the useful signal and outputs it to an oscilloscope in analog form for waveform display and storage and delivers it to a computer to perform a Fast Fourier Transform (FFT) and convert the pulse sound waveform into a heartbeat frequency. Furthermore, it also uses an audio signal amplifier to deliver the pulse sound by speaker. The study observed the principles of Traditional Chinese Medicine's pulsing techniques, where pulse signals at places called "cun", "guan" and "chi" of the left hand were measured during lifting (100 g), searching (125 g) and pressing (150 g) actions. Because the system collects the vibration sound caused by the pulse, the sensor itself is not affected by the applied pressure, unlike current pulse piezoelectric sensing instruments, therefore, under any kind of pulsing pressure, it displays pulse changes and waveforms with the same accuracy. We provide an acquired pulse and waveform signal suitable for Chinese Medicine practitioners' objective pulse diagnosis, thus providing a scientific basis for this Traditional Chinese Medicine practice. This study also presents a novel circuit design using an active filtering method. An operational amplifier with its differential features eliminates the interference from external signals, including the instant high-frequency noise. In addition, the system has the advantages of simple circuitry, cheap cost and high precision.

  12. Nova pulse power system description and status

    SciTech Connect

    Holloway, R.W.; Whitham, K.; Merritt, B.T.; Gritton, D.G.; Oicles, J.A.

    1981-06-01

    The Nova laser system is designed to produce critical data in the nation's inertial confinement fusion effort. It is the world's largest peak power laser and presents various unique pulse power problems. In this paper, pulse power systems for this laser are described, the evolutionary points from prior systems are pointed out, and the current status of the hardware is given.

  13. Beamlet pulsed-power system

    SciTech Connect

    Larson, D.

    1996-06-01

    The 13-MJ Beamlet pulsed-power system provides power to the 512 flash lamps in the cavity and booster amplifiers. Since the flash lamps pump all of the apertures in the 2 x 2 amplifier array, the capacitor bank provides roughly four times the energy required to pump the single active beam line. During the 40 s prior to the shot, the capacitors are charged by constant-current power supplies. Ignitron switches transfer the capacitor energy to the flash lamps via coaxial cables. A preionization system triggers the flash lamps and delivers roughly 1 % of the capacitor energy 200 {mu}s prior to the main discharge. This is the first time flash-lamp preionization has been used in a large facility. Preionization improves the amplifier efficiency by roughly 5% and increases the lifetime of the flash lamps. LabVIEW control panels provide an operator interface with the modular controls and diagnostics. To improve the reliability of the system, high-energy-density, self-healing, metallized dielectric capacitors are used. High-frequency, voltage-regulated switching power supplies are integrated into each module on Beamlet, allowing greater independence among the modules and improved charge voltage accuracy, flexibility, and repeatability.

  14. Effects of Shared Electronic Health Record Systems on Drug-Drug Interaction and Duplication Warning Detection

    PubMed Central

    Rinner, Christoph; Grossmann, Wilfried; Sauter, Simone Katja; Wolzt, Michael; Gall, Walter

    2015-01-01

    Shared electronic health records (EHRs) systems can offer a complete medication overview of the prescriptions of different health care providers. We use health claims data of more than 1 million Austrians in 2006 and 2007 with 27 million prescriptions to estimate the effect of shared EHR systems on drug-drug interaction (DDI) and duplication warnings detection and prevention. The Austria Codex and the ATC/DDD information were used as a knowledge base to detect possible DDIs. DDIs are categorized as severe, moderate, and minor interactions. In comparison to the current situation where only DDIs between drugs issued by a single health care provider can be checked, the number of warnings increases significantly if all drugs of a patient are checked: severe DDI warnings would be detected for 20% more persons, and the number of severe DDI warnings and duplication warnings would increase by 17%. We show that not only do shared EHR systems help to detect more patients with warnings but DDIs are also detected more frequently. Patient safety can be increased using shared EHR systems. PMID:26682218

  15. Effects of Shared Electronic Health Record Systems on Drug-Drug Interaction and Duplication Warning Detection.

    PubMed

    Rinner, Christoph; Grossmann, Wilfried; Sauter, Simone Katja; Wolzt, Michael; Gall, Walter

    2015-01-01

    Shared electronic health records (EHRs) systems can offer a complete medication overview of the prescriptions of different health care providers. We use health claims data of more than 1 million Austrians in 2006 and 2007 with 27 million prescriptions to estimate the effect of shared EHR systems on drug-drug interaction (DDI) and duplication warnings detection and prevention. The Austria Codex and the ATC/DDD information were used as a knowledge base to detect possible DDIs. DDIs are categorized as severe, moderate, and minor interactions. In comparison to the current situation where only DDIs between drugs issued by a single health care provider can be checked, the number of warnings increases significantly if all drugs of a patient are checked: severe DDI warnings would be detected for 20% more persons, and the number of severe DDI warnings and duplication warnings would increase by 17%. We show that not only do shared EHR systems help to detect more patients with warnings but DDIs are also detected more frequently. Patient safety can be increased using shared EHR systems.

  16. Active pulse synchronization for OPCPA systems

    NASA Astrophysics Data System (ADS)

    Ueffing, Moritz; Metzger, Thomas; Deng, Yunpei; Schwarz, Alexander; Krausz, Ferenc; Kienberger, Reinhard

    2011-05-01

    The parametric amplification in nonlinear crystals requires both spacial and temporal stability of pump and seed pulses to attain stability of the amplified pulse. Especially the development of thin disk pump sources with pulse lengths down to 2 ps requires a temporal stability well beyond 100 fs . To reduce the timing shifts between pump and seed pulses in OPCPA systems we introduce a novel, active pulse synchronization system combining a high precision translation stage and a piezo-electric driven mirror. The timing jitter reduction of OPCPAs with kHz repetition rate demands a fast detection system allowing nearly shot to shot correction. Therefore the spectrum of a cross-correlation between the 1030 nm , 1 nm bandwidth pump and a broad bandwidth Ti:Sa seed pulse stretched to 10 ps in a BBO crystal is directly and in real time measured using a position sensitive detector. This method can easily be adopted to other OPA/OPCPA systems giving the chance to correct not only for slow drifts but also for fluctuations up to 300 Hz .

  17. Laser system using ultra-short laser pulses

    DOEpatents

    Dantus, Marcos; Lozovoy, Vadim V.; Comstock, Matthew

    2009-10-27

    A laser system using ultrashort laser pulses is provided. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and a SHG crystal.

  18. Stimulation of unidirectional pulses in excitable systems

    NASA Astrophysics Data System (ADS)

    Friedman, M.; Ovsyshcher, I. E.; Fleidervish, I.; Crystal, E.; Rabinovitch, A.

    2004-10-01

    Using a judicious spatial shape of input current pulses (and electrodes), responses of an excitable system (FitzHugh-Nagumo) appear as unidirectional pulses (UDP’s) instead of bidirectional ones (in one dimension) or circular ones (in two dimensions). The importance of the UDP’s for a possible mechanism for pinpointing the reentry cycle position and for a possible use in tachycardia suppression is discussed.

  19. Pulsed Energy Systems for Generating Plasmas

    NASA Technical Reports Server (NTRS)

    Rose, M. Franklin; Shotts, Z.

    2005-01-01

    This paper will describe the techniques needed to electrically generate highly ionized dense plasmas for a variety of applications. The components needed in pulsed circuits are described in terms of general performance parameters currently available from commercial vendors. Examples of pulsed systems using these components are described and technical data from laboratory experiments presented. Experimental data are given for point designs, capable of multi-megawatt power levels.

  20. Artist's concept of Pulse Detonation Propulsion System

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Pictured is an artist's concept of an advanced chemical propulsion system called Pulse Detonation. Long term technology research in this advanced propulsion system has the potential to dramatically change the way we think about space propulsion systems. This research is expected to significantly reduce the cost of space travel within the next 25 years.

  1. Single ectopic ureteral orifice with bilateral duplicated renal collecting systems in an adult girl: Diagnosis by magnetic resonance urography.

    PubMed

    Tang, Min; Wang, Quanrongzi; Liu, Bianjiang; Li, Jie; Lu, Qiang; Song, Ninghong; Wang, Zengjun; Zhang, Wei

    2015-01-01

    Renal duplication accompanied by ureteral ectopia is an uncommon urinary congenital abnormality. We report the case of a 21-year-old girl who suffered from lifelong continuous urinary leakage. She was finally diagnosed with bilateral duplicated collecting systems complicated with right ectopic ureteral orifice - an extremely rare case. The patient underwent ureteric re-implantation for the ectopic side, and her urinary incontinence ceased soon thereafter. In this case, traditional imaging failed to show the exact insertion of an ectopic ureter. However, magnetic resonance urography combined with retrograde intubation radiography successfully depicted the point of ureteric insertion, which may make the diagnostic process accurate and efficient.

  2. Chaotic carrier pulse position modulation communication system and method

    DOEpatents

    Abarbanel, Henry D. I.; Larson, Lawrence E.; Rulkov, Nikolai F.; Sushchik, Mikhail M.; Tsimring, Lev S.; Volkovskii, Alexander R.

    2001-01-01

    A chaotic carrier pulse position modulation communication system and method is disclosed. The system includes a transmitter and receiver having matched chaotic pulse regenerators. The chaotic pulse regenerator in the receiver produces a synchronized replica of a chaotic pulse train generated by the regenerator in the transmitter. The pulse train from the transmitter can therefore act as a carrier signal. Data is encoded by the transmitter through selectively altering the interpulse timing between pulses in the chaotic pulse train. The altered pulse train is transmitted as a pulse signal. The receiver can detect whether a particular interpulse interval in the pulse signal has been altered by reference to the synchronized replica it generates, and can therefore detect the data transmitted by the receiver. Preferably, the receiver predicts the earliest moment in time it can expect a next pulse after observation of at least two consecutive pulses. It then decodes the pulse signal beginning at a short time before expected arrival of a pulse.

  3. Pulse thermal energy transport/storage system

    DOEpatents

    Weislogel, Mark M.

    1992-07-07

    A pulse-thermal pump having a novel fluid flow wherein heat admitted to a closed system raises the pressure in a closed evaporator chamber while another interconnected evaporator chamber remains open. This creates a large pressure differential, and at a predetermined pressure the closed evaporator is opened and the opened evaporator is closed. This difference in pressure initiates fluid flow in the system.

  4. Compact inductive energy storage pulse power system.

    PubMed

    K, Senthil; Mitra, S; Roy, Amitava; Sharma, Archana; Chakravarthy, D P

    2012-05-01

    An inductive energy storage pulse power system is being developed in BARC, India. Simple, compact, and robust opening switches, capable of generating hundreds of kV, are key elements in the development of inductive energy storage pulsed power sources. It employs an inductive energy storage and opening switch power conditioning techniques with high energy density capacitors as the primary energy store. The energy stored in the capacitor bank is transferred to an air cored storage inductor in 5.5 μs through wire fuses. By optimizing the exploding wire parameters, a compact, robust, high voltage pulse power system, capable of generating reproducibly 240 kV, is developed. This paper presents the full details of the system along with the experimental data.

  5. Testing Mendelian inheritance from field-collected parasites: Revealing duplicated loci enables correct inference of reproductive mode and mating system.

    PubMed

    Detwiler, Jillian T; Criscione, Charles D

    2011-09-01

    Cryptic aspects of parasite population biology, e.g., mating systems, are increasingly being inferred from polymorphic and co-dominant genetic markers such as microsatellite loci. Underlying the use of such co-dominant markers is the assumption of Mendelian inheritance. The failure to meet this assumption can lead to artifactual statistics and erroneous population inferences. Here, we illustrate the importance of testing the Mendelian segregation and assortment of genetic markers and demonstrate how field-collected samples can be utilised for this purpose. To examine the reproductive mode and mating system of hermaphroditic parasites, we developed microsatellites for the cestode, Oochoristica javaensis. Among loci, we found a bimodal distribution of F(IS) (a fixation index that quantifies the deviation from Hardy-Weinberg equilibrium within subpopulations) values where loci were either highly negative (close to -1) or highly positive (∼0.8). By conducting tests of Mendelian segregation from natural crosses, we determined that loci with negative F(IS) values were in fact duplicated loci that were amplified by a single primer pair. Genetic crosses also provided linkage data and indicated that the duplicated loci most likely arose via tandem duplications rather than whole genome/chromosome duplications. By correcting for the duplicated loci, we were able to correctly infer that O. javaensis has sexual reproduction, but the mating system is highly inbred. To assist others in testing Mendelian segregation and independent assortment from natural samples, we discuss the benefits and limitations, and provide guidelines for particular parasite systems amenable to the methods employed here.

  6. Development of a pulsed-microwiggler system

    NASA Astrophysics Data System (ADS)

    Warren, Roger W.; Fortgang, Clifford M.

    1993-07-01

    Pulsed microwigglers can develop unusually high magnetic fields with short periods. They find potential applications in compact system that use low energy accelerators that can generate very bright electron beams, and in systems that lase on high harmonics of the fundamental frequency. In the past many of the unique properties of pulsed wigglers have been addressed. In this paper we will concentrate on our solutions to the practical problems that must be solved to make such a device work. Among other topics we will discuss the following: achieving adequate precision in fabrication; controlling quadrupole fields; "trimming" the field after fabrication; providing structural support, cooling, and vacuum; and coupling to the pulsed power supply. Completed microwigglers of our design will be installed in an FEL this summer to lase on the fundamental in the red part of the spectrum and on the third harmonic in the ultraviolet.

  7. Development of a pulsed microwiggler system

    SciTech Connect

    Warren, R.W.; Fortgang, C.M.

    1992-01-01

    Pulsed microwigglers can develop unusually high magnetic fields with short periods. They find potential applications in compact systems that use low energy accelerators that can generate very bright electron beams, and in systems that lase on high harmonics of the fundamental frequency. In the past, many of the unique properties of pulsed wigglers have been addressed. In this paper, we will concentrate on our solutions to the practical problems that must be solved to make such a device work. Among other topics, we will discuss the following: achieving adequate precision in fabrication; controlling quadrupole fields; trimming'' the field after fabrication; providing structural support, cooling, and vacuum; and coupling to the pulsed power supply. Completed microwigglers of our design will be installed in an FEL this summer to lase on the fundamental in the red part of the spectrum and on the third harmonic in the ultraviolet.

  8. Development of a pulsed microwiggler system

    SciTech Connect

    Warren, R.W.; Fortgang, C.M.

    1992-09-01

    Pulsed microwigglers can develop unusually high magnetic fields with short periods. They find potential applications in compact systems that use low energy accelerators that can generate very bright electron beams, and in systems that lase on high harmonics of the fundamental frequency. In the past, many of the unique properties of pulsed wigglers have been addressed. In this paper, we will concentrate on our solutions to the practical problems that must be solved to make such a device work. Among other topics, we will discuss the following: achieving adequate precision in fabrication; controlling quadrupole fields; ``trimming`` the field after fabrication; providing structural support, cooling, and vacuum; and coupling to the pulsed power supply. Completed microwigglers of our design will be installed in an FEL this summer to lase on the fundamental in the red part of the spectrum and on the third harmonic in the ultraviolet.

  9. Controlling laser beam irradiation area using an optical duplicate system to improve satellite-ground laser communications

    NASA Astrophysics Data System (ADS)

    Nakayama, Tomoko; Takayama, Yoshihisa; Fujikawa, Chiemi; Kodate, Kashiko

    2016-08-01

    To improve the quality of ground to satellite laser communications, we propose an optical duplicate system of the optical ground station. Our proposed approach can be used to control the beam irradiation area for a satellite position without changing the total power of the output beam and the mechanical drive unit; this is performed by controlling the input pattern of a liquid crystal filter inserted in the input plane of the optical duplicate system. Most of the power of the diffracted laser beam emitted from the ground is focused on the optical axis. By distributing the power to side lobes, it is possible to extend the coverage area for a satellite position. This system allows the laser beam irradiation area to be controlled by a sufficient degree by adjusting the threshold of the satellite reception level. We verify the efficacy of the system using wave optics numerical calculations.

  10. SITE TECHNOLOGY CAPSULE: SONOTECH PULSE COMBUSTION SYSTEM

    EPA Science Inventory

    Sonotech has targeted waste incineration as a potential application for this technology. Based on bench-scale rotary-kiln simulator tests, Sonotech proposed a demonstration under the SITE program to evaluate the Sonotech pulse combustion system on a larger scale at EPA's IRF in J...

  11. SITE TECHNOLOGY CAPSULE: SONOTECH PULSE COMBUSTION SYSTEM

    EPA Science Inventory

    Sonotech has targeted waste incineration as a potential application for this technology. Based on bench-scale rotary-kiln simulator tests, Sonotech proposed a demonstration under the SITE program to evaluate the Sonotech pulse combustion system on a larger scale at EPA's IRF in J...

  12. Double pulse Thomson scattering system at RTP

    SciTech Connect

    Beurskens, M.N.; Barth, C.J.; Chu, C.C.; Donne, A.J.; Herranz, J.A.; Lopes Cardozo, N.J.; van der Meiden, H.J.; Pijper, F.J.

    1997-01-01

    In this article a double pulse multiposition Thomson scattering diagnostic, under construction at RTP, is discussed. Light from a double pulsed ruby laser (pulse separation: 10{endash}800 {mu}s, max. 2{times}12.5 J) is scattered by the free electrons of the tokamak plasma and relayed to a Littrow polychromator for spectral analysis. The spectrally resolved light is recorded by two ICCD detectors. Simulations show that the system sensitivity will be such that electron temperatures in the range of 100 eV{endash}7 keV can be determined with an accuracy as good as 2{percent}{endash}3{percent} for electron densities of 10{sup 20} m{sup {minus}3}, with a spatial resolution down to 2.6 mm. With this diagnostic the dynamics of small scale structures in the electron temperature profile will be studied. {copyright} {ital 1997 American Institute of Physics.}

  13. Three-Phase Scheme for Supporting Time-Constrained Data with Duplication in Wireless Broadcast Systems

    NASA Astrophysics Data System (ADS)

    Chen, Chao-Chun; Lin, Lien-Fa; Wang, Shih-Chia

    The wireless data broadcast techniques raised in 1990s. Since the wireless data dissemination techniques are emerged, more and more data services are proposed based on the wireless data broadcast techniques in these years. Among the new services, the time-constraint data broadcast service is critical for many real-time related applications, and has been studied in the recent years. However, the related works did not consider the duplicate pages of requests on data scheduling. Hence, in this paper, we consider the duplicate pages in the multi-page time-constraint data broadcast service. We first proposed a duplication page-optimized architecture for supporting the multi-page time-constraint data broadcast service. We then proposed a three-phase scheme for the time-slot sharing optimizer to improve the bandwidth utility of the TDA-based program. The experiments reveal that our proposed indeed significantly reduce the number of used channels for a data broadcast server.

  14. Hyper dispersion pulse compressor for chirped pulse amplification systems

    DOEpatents

    Barty, Christopher P. J.

    2011-11-29

    A grating pulse compressor configuration is introduced for increasing the optical dispersion for a given footprint and to make practical the application for chirped pulse amplification (CPA) to quasi-narrow bandwidth materials, such as Nd:YAG. The grating configurations often use cascaded pairs of gratings to increase angular dispersion an order of magnitude or more. Increased angular dispersion allows for decreased grating separation and a smaller compressor footprint.

  15. Acoustooptic pulse-echo transducer system

    NASA Technical Reports Server (NTRS)

    Claus, R. O.; Wade, J. C.

    1983-01-01

    A pulse-echo transducer system which uses an ultrasonic generating element and an optical detection technique is described. The transmitting transducer consists of a concentric ring electrode pattern deposited on a circular, X-cut quartz substrate with a circular hole in the center. The rings are independently pulsed with a sequence high voltage signals phased in such a way that the ultrasonic waves generated by the separate rings superimpose to produce a composite field which is focused at a controllable distance below the surface of the specimen. The amplitude of the field reflected from this focus position is determined by the local reflection coefficient of the medium at the effective focal point. By processing the signals received for a range of ultrasonic transducer array focal lengths, the system can be used to locate and size anomalies within solids and liquids. Applications in both nondestructive evaluation and biomedical scanning are suggested.

  16. Performance of the LAGUNA pulsed power system

    SciTech Connect

    Goforth, J.H.; Caird, R.S.; Fowler, C.M.; Greene, A.E.; Kruse, H.W.; Lindemuth, I.R.; Oona, H.; Reinovsky, R.E.

    1987-01-01

    The goal of the LAGUNA experimental series of the Los Alamos National Laboratory TRAILMASTER program is to accelerate an annular aluminum plasma z-pinch to greater than one hundred kilojoules of implosion kinetic energy. To accomplish this, an electrical pulse >5.5 MA must be delivered to a 20 nH load in approx.1 ..mu..s. The pulsed power system for these experiments consists of a capacitor bank for initial energy storage, a helical explosive-driven magnetic-flux compression generator for the prime power supply and opening and closing switches for power conditioning. While we have not yet achieved our design goal of 15 MA delivered to the inductive store of the system, all major components have functioned successfully at the 10 MA level. Significant successes and some difficulties experienced in these experiments are described.

  17. [Evidence of the public-private mix in healthcare systems in countries with duplicated coverage: greater inequities and segmentation in National Health Systems].

    PubMed

    Santos, Isabela Soares

    2011-06-01

    This paper seeks to identify the potential negative effects of private health insurance on the universality of National Health Systems. It systematizes the operational concepts of the public-private mix model and presents the results from international research into duplicated and supplementary coverage that shows that universality is negatively affected by inequities derived from duplicated coverage though not from supplementary coverage. It demystifies the supplementary nature of private health insurance as the villain in the Brazilian healthcare system and recommends that public policies should be fully oriented to improving the public health system instead of private health insurance.

  18. EMR management system for patient pulse data.

    PubMed

    Lee, Junyoung

    2012-10-01

    The purpose of this study is to build an integrated medical information system for effective database management of clinical information and to improve the existing Electronic Medical Record (EMR)-based system that is currently being used in hospitals. The integrated medical information system of hospitals consists of an Order Communication System (OCS), Picture Archiving Communication System (PACS), and Laboratory Information System (LIS), as well as Electronic Medical Record (EMR). It is designed so that remote health screening and patient data search can be accessed through a high speed network-even in remote areas-in order to effectively manage data on medical treatment that patients received at their respective hospitals. The existing oriental treatment system is one in which the doctor requires the patient to visit the hospital in person, so as to be able to check the patient's pulse and measure it with his hand for proper diagnosis and treatment. However, due to the recent development of digitalized medical measurement equipment, not only can doctors now check a patient's pulse without touching it directly, but the measured data are computerized and stored into the database as the electronic obligation record. Thus, even if a patient cannot visit the hospital, proper medical treatment is available by analyzing the patient's medical history and diagnosis process in the remote area. Furthermore, when a comprehensive medical testing center system including the people medical examination and diverse physical examination is established, the quality of medical service is expected to be improved than now.

  19. Injection locked oscillator system for pulsed metal vapor lasers

    DOEpatents

    Warner, Bruce E.; Ault, Earl R.

    1988-01-01

    An injection locked oscillator system for pulsed metal vapor lasers is disclosed. The invention includes the combination of a seeding oscillator with an injection locked oscillator (ILO) for improving the quality, particularly the intensity, of an output laser beam pulse. The present invention includes means for matching the first seeder laser pulses from the seeding oscillator to second laser pulses of a metal vapor laser to improve the quality, and particularly the intensity, of the output laser beam pulse.

  20. Pulsed photoneutron interrogation: The GNT demonstration system

    SciTech Connect

    Jones, J.L.; Harker, Y.D.; Yoon, W.Y.; Hoggan, J.M.; McManus, G.J.

    1994-10-01

    The Idaho National Engineering Laboratory (INEL) has developed and tested an active photon interrogation technique to support the Department of Energy`s (DOE) Office of National Security and Nonproliferation (NN) mission related to verification technologies development. The INEL concept, referred to as the Gamma-Neutron Threshold (GNT) technology, uses a transportable, field-deployable, selective-energy (2 to 10 MeV), pulsed, electron accelerator to produce energetic X-rays having a bremsstrahlung spectrum. The energetic X-rays induce neutrons in many proliferation-limited items via direct photoneutron/photofission interactions. The time-dependent neutron response, as a function of the electron beam energy, is measured with a tripod-mounted, detector assembly and a portable data acquisition system. The portable detector assembly has been specifically designed to operate in very intense, pulsed X-ray environments. The GNT technique measures both the prompt and delayed neutron emission after each accelerator pulse. This report fully describes each component of this system and presents various signature results based on these emissions.

  1. Investigation of a Pulsed 1550 nm Fiber Laser System

    DTIC Science & Technology

    2015-12-15

    14. ABSTRACT There is a strong need for a pulsed laser system at eye safe wavelengths for illuminator applications . High power pulsed 1550 nm fiber...system at eye safe wavelengths for illuminator applications . High power pulsed 1550 nm fiber lasers systems are able to generate, shaped, pulses at...for illuminator applications . Considerations which impact the wavelength to be used are the transmissivity of the atmosphere and the responsivity of

  2. Investigation of a pulsed electrothermal thruster system

    NASA Technical Reports Server (NTRS)

    Burton, R. L.; Goldstein, S. A.; Hilko, B. K.; Tidman, D. A.; Winsor, N. K.

    1984-01-01

    The performance of an ablative wall Pulsed Electrothermal (PET) thruster is accurately characterized on a calibrated thrust stand, using polyethylene propellant. The thruster is tested for four configurations of capillary length and pulse length. The exhaust velocity is determined with twin time-of-flight photodiode stagnation probes, and the ablated mass is measured from the loss over ten shots. Based on the measured thrust impulse and the ablated mass, the specific impulse varies from 1000 to 1750 seconds. The thrust to power varies from .05 N/kW (quasi-steady mode) to .10 N/kW (unsteady mode). The thruster efficiency varies from .56 at 1000 seconds to .42 at 1750 seconds. A conceptual design is presented for a 40 kW PET propulsion system. The point design system performance is .62 system efficiency at 1000 seconds specific impulse. The system's reliability is enhanced by incorporating 20, 20 kW thruster modules which are fired in pairs. The thruster design is non-ablative, and uses water propellant, from a central storage tank, injected through the cathode.

  3. An Optimal Pulse System Design by Multichannel Sensors Fusion.

    PubMed

    Wang, Dimin; Zhang, David; Lu, Guangming

    2016-03-01

    Pulse diagnosis, recognized as an important branch of traditional Chinese medicine (TCM), has a long history for health diagnosis. Certain features in the pulse are known to be related with the physiological status, which have been identified as biomarkers. In recent years, an electronic equipment is designed to obtain the valuable information inside pulse. Single-point pulse acquisition platform has the benefit of low cost and flexibility, but is time consuming in operation and not standardized in pulse location. The pulse system with a single-type sensor is easy to implement, but is limited in extracting sufficient pulse information. This paper proposes a novel system with optimal design that is special for pulse diagnosis. We combine a pressure sensor with a photoelectric sensor array to make a multichannel sensor fusion structure. Then, the optimal pulse signal processing methods and sensor fusion strategy are introduced for the feature extraction. Finally, the developed optimal pulse system and methods are tested on pulse database acquired from the healthy subjects and the patients known to be afflicted with diabetes. The experimental results indicate that the classification accuracy is increased significantly under the optimal design and also demonstrate that the developed pulse system with multichannel sensors fusion is more effective than the previous pulse acquisition platforms.

  4. High energy ultrashort pulses via hollow fiber compression of a fiber chirped pulse amplification system.

    PubMed

    Hädrich, Steffen; Rothhardt, Jan; Eidam, Tino; Limpert, Jens; Tünnermann, Andreas

    2009-03-02

    A simple, robust and compact pulse compressor for a high-repetition rate high-peak power fiber chirped pulse amplification system is presented. We use noble-gas-filled hollow fibers for spectral broadening of the optical pulses via self-phase modulation. Subsequent compression with chirped mirrors shortens the pulses by more than a factor of 10. Pulses shorter than 70 fs with pulse energies of the order of 100 mu J have been obtained resulting in a peak power up to 1 GW at 30.3kHz. Additionally, nonlinear polarization rotation has been used for temporal pulse cleaning during the nonlinear compression at 30.3 kHz and 100 kHz, respectively.

  5. Duplicated leptin receptors in two species of eel bring new insights into the evolution of the leptin system in vertebrates.

    PubMed

    Morini, Marina; Pasquier, Jérémy; Dirks, Ron; van den Thillart, Guido; Tomkiewicz, Jonna; Rousseau, Karine; Dufour, Sylvie; Lafont, Anne-Gaëlle

    2015-01-01

    Since its discovery in mammals as a key-hormone in reproduction and metabolism, leptin has been identified in an increasing number of tetrapods and teleosts. Tetrapods possess only one leptin gene, while most teleosts possess two leptin genes, as a result of the teleost third whole genome duplication event (3R). Leptin acts through a specific receptor (LEPR). In the European and Japanese eels, we identified two leptin genes, and for the first time in vertebrates, two LEPR genes. Synteny analyses indicated that eel LEPRa and LEPRb result from teleost 3R. LEPRb seems to have been lost in the teleost lineage shortly after the elopomorph divergence. Quantitative PCRs revealed a wide distribution of leptins and LEPRs in the European eel, including tissues involved in metabolism and reproduction. Noticeably, leptin1 was expressed in fat tissue, while leptin2 in the liver, reflecting subfunctionalization. Four-month fasting had no impact on the expression of leptins and LEPRs in control European eels. This might be related to the remarkable adaptation of silver eel metabolism to long-term fasting throughout the reproductive oceanic migration. In contrast, sexual maturation induced differential increases in the expression of leptins and LEPRs in the BPG-liver axis. Leptin2 was strikingly upregulated in the liver, the central organ of the reproductive metabolic challenge in teleosts. LEPRs were differentially regulated during sexual maturation, which may have contributed to the conservation of the duplicated LEPRs in this species. This suggests an ancient and positive role of the leptin system in the vertebrate reproductive function. This study brings new insights on the evolutionary history of the leptin system in vertebrates. Among extant vertebrates, the eel represents a unique case of duplicated leptins and leptin receptors as a result of 3R.

  6. Duplicated Leptin Receptors in Two Species of Eel Bring New Insights into the Evolution of the Leptin System in Vertebrates

    PubMed Central

    Morini, Marina; Pasquier, Jérémy; Dirks, Ron; van den Thillart, Guido; Tomkiewicz, Jonna; Rousseau, Karine; Dufour, Sylvie; Lafont, Anne-Gaëlle

    2015-01-01

    Since its discovery in mammals as a key-hormone in reproduction and metabolism, leptin has been identified in an increasing number of tetrapods and teleosts. Tetrapods possess only one leptin gene, while most teleosts possess two leptin genes, as a result of the teleost third whole genome duplication event (3R). Leptin acts through a specific receptor (LEPR). In the European and Japanese eels, we identified two leptin genes, and for the first time in vertebrates, two LEPR genes. Synteny analyses indicated that eel LEPRa and LEPRb result from teleost 3R. LEPRb seems to have been lost in the teleost lineage shortly after the elopomorph divergence. Quantitative PCRs revealed a wide distribution of leptins and LEPRs in the European eel, including tissues involved in metabolism and reproduction. Noticeably, leptin1 was expressed in fat tissue, while leptin2 in the liver, reflecting subfunctionalization. Four-month fasting had no impact on the expression of leptins and LEPRs in control European eels. This might be related to the remarkable adaptation of silver eel metabolism to long-term fasting throughout the reproductive oceanic migration. In contrast, sexual maturation induced differential increases in the expression of leptins and LEPRs in the BPG-liver axis. Leptin2 was strikingly upregulated in the liver, the central organ of the reproductive metabolic challenge in teleosts. LEPRs were differentially regulated during sexual maturation, which may have contributed to the conservation of the duplicated LEPRs in this species. This suggests an ancient and positive role of the leptin system in the vertebrate reproductive function. This study brings new insights on the evolutionary history of the leptin system in vertebrates. Among extant vertebrates, the eel represents a unique case of duplicated leptins and leptin receptors as a result of 3R. PMID:25946034

  7. Pulse-burst laser systems for fast Thomson scattering (invited)

    SciTech Connect

    Den Hartog, D. J.; Ambuel, J. R.; Holly, D. J.; Robl, P. E.; Borchardt, M. T.; Falkowski, A. F.; Harris, W. S.; Parke, E.; Reusch, J. A.; Stephens, H. D.; Yang, Y. M.

    2010-10-15

    Two standard commercial flashlamp-pumped Nd:YAG (YAG denotes yttrium aluminum garnet) lasers have been upgraded to ''pulse-burst'' capability. Each laser produces a burst of up to 15 2 J Q-switched pulses (1064 nm) at repetition rates of 1-12.5 kHz. Variable pulse-width drive (0.15-0.39 ms) of the flashlamps is accomplished by insulated gate bipolar transistor (IGBT) switching of electrolytic capacitor banks. Direct control of the laser Pockels cell drive enables optimal pulse energy extraction, and up to four 2 J laser pulses during one flashlamp pulse. These lasers are used in the Thomson scattering plasma diagnostic system on the MST reversed-field pinch to record the dynamic evolution of the electron temperature profile and temperature fluctuations. To further these investigations, a custom pulse-burst laser system with a maximum pulse repetition rate of 250 kHz is now being commissioned.

  8. Pulse-burst laser systems for fast Thomson scattering (invited).

    PubMed

    Den Hartog, D J; Ambuel, J R; Borchardt, M T; Falkowski, A F; Harris, W S; Holly, D J; Parke, E; Reusch, J A; Robl, P E; Stephens, H D; Yang, Y M

    2010-10-01

    Two standard commercial flashlamp-pumped Nd:YAG (YAG denotes yttrium aluminum garnet) lasers have been upgraded to "pulse-burst" capability. Each laser produces a burst of up to 15 2 J Q-switched pulses (1064 nm) at repetition rates of 1-12.5 kHz. Variable pulse-width drive (0.15-0.39 ms) of the flashlamps is accomplished by insulated gate bipolar transistor (IGBT) switching of electrolytic capacitor banks. Direct control of the laser Pockels cell drive enables optimal pulse energy extraction, and up to four 2 J laser pulses during one flashlamp pulse. These lasers are used in the Thomson scattering plasma diagnostic system on the MST reversed-field pinch to record the dynamic evolution of the electron temperature profile and temperature fluctuations. To further these investigations, a custom pulse-burst laser system with a maximum pulse repetition rate of 250 kHz is now being commissioned.

  9. System for generating shaped optical pulses and measuring optical pulses using spectral beam deflection (SBD)

    DOEpatents

    Skupsky, S.; Kessler, T.J.; Letzring, S.A.

    1993-11-16

    A temporally shaped or modified optical output pulse is generated from a bandwidth-encoded optical input pulse in a system in which the input pulse is in the form of a beam which is spectrally spread into components contained within the bandwidth, followed by deflection of the spectrally spread beam (SBD) thereby spatially mapping the components in correspondence with the temporal input pulse profile in the focal plane of a lens, and by spatially selective attenuation of selected components in that focal plane. The shaped or modified optical output pulse is then reconstructed from the attenuated spectral components. The pulse-shaping system is particularly useful for generating optical pulses of selected temporal shape over a wide range of pulse duration, such pulses finding application in the fields of optical communication, optical recording and data storage, atomic and molecular spectroscopy and laser fusion. An optical streak camera is also provided which uses SBD to display the beam intensity in the focal plane as a function of time during the input pulse. 10 figures.

  10. System for generating shaped optical pulses and measuring optical pulses using spectral beam deflection (SBD)

    DOEpatents

    Skupsky, Stanley; Kessler, Terrance J.; Letzring, Samuel A.

    1993-01-01

    A temporally shaped or modified optical output pulse is generated from a bandwidth-encoded optical input pulse in a system in which the input pulse is in the form of a beam which is spectrally spread into components contained within the bandwidth, followed by deflection of the spectrally spread beam (SBD) thereby spatially mapping the components in correspondence with the temporal input pulse profile in the focal plane of a lens, and by spatially selective attenuation of selected components in that focal plane. The shaped or modified optical output pulse is then reconstructed from the attenuated spectral components. The pulse-shaping system is particularly useful for generating optical pulses of selected temporal shape over a wide range of pulse duration, such pulses finding application in the fields of optical communication, optical recording and data storage, atomic and molecular spectroscopy and laser fusion. An optical streak camera is also provided which uses SBD to display the beam intensity in the focal plane as a function of time during the input pulse.

  11. Pulse compression techniques to improve modulated pulsed laser line scan systems

    NASA Astrophysics Data System (ADS)

    Lee, Robert W.; Nash, Justin K.; Cochenour, Brandon M.; Mullen, Linda J.

    2015-05-01

    A modulated pulse laser imaging system has been developed which utilizes coded/chirped RF modulation to mitigate the adverse effects of optical scattering in degraded visual underwater environments. Current laser imaging techniques employ either short pulses or single frequency modulated pulses to obtain both intensity and range images. Systems using short pulses have high range resolution but are susceptible to scattering due to the wide bandwidth nature of the pulse. Range gating can be used to limit the effects of backscatter, but this can lead to blind spots in the range image. Modulated pulse systems can help suppress the contribution from scattered light in generated imagery without gating the receiver. However, the use of narrowband, single tone modulation results in limited range resolution where small targets are camouflaged within the background. This drives the need for systems which have high range resolution while still suppressing the effects of scattering caused by the environment. Coded/chirped modulated pulses enable the use of radar pulse compression techniques to substantially increase range resolution while also providing a way to discriminate the object of interest from the light scattered from the environment. Linearly frequency chirped waveforms and phase shift keyed barker codes were experimentally investigated to determine the effects that pulse compression would have on intensity/range data. The effect of modulation frequency on the data produced with both wideband and narrowband modulation was also investigated. The results from laboratory experiments will be presented and compared to model predictions.

  12. Adaptive control system for pulsed megawatt klystrons

    DOEpatents

    Bolie, Victor W.

    1992-01-01

    The invention provides an arrangement for reducing waveform errors such as errors in phase or amplitude in output pulses produced by pulsed power output devices such as klystrons by generating an error voltage representing the extent of error still present in the trailing edge of the previous output pulse, using the error voltage to provide a stored control voltage, and applying the stored control voltage to the pulsed power output device to limit the extent of error in the leading edge of the next output pulse.

  13. Note: Fast double pulse system using transmission line characteristic of the pulse forming line

    NASA Astrophysics Data System (ADS)

    Sharma, Surender Kumar; Deb, P.; Sharma, Archana; Shyam, A.

    2012-11-01

    A fast double pulse system is designed and developed using the transmission line characteristic of the pulse forming line to generate two flat top rectangular pulses with extremely short interpulse repetition interval. The helical pulse forming line (HPFL) is used to generate longer duration rectangular pulses in smaller length. The HPFL inner conductor is made up of 13 turns of SS-304 strip, 39.5 mm wide and 0.5 mm thick wounded on the 168 mm delrin cylinder. The impedance of the HPFL is 22 Ω. The 2 turns at the input side of the HPFL are wounded with ethylene propylene rubber tape on the strip. The HPFL is charged to 180 kV in 4 μs and discharges into a matched load through a spark switch. It generates two flat top rectangular pulses of 90 kV, 100 ns duration with the 30 ns interval between the pulses. The system can be used as fast double pulse source for repetitive pulsed power loads.

  14. Note: fast double pulse system using transmission line characteristic of the pulse forming line.

    PubMed

    Sharma, Surender Kumar; Deb, P; Sharma, Archana; Shyam, A

    2012-11-01

    A fast double pulse system is designed and developed using the transmission line characteristic of the pulse forming line to generate two flat top rectangular pulses with extremely short interpulse repetition interval. The helical pulse forming line (HPFL) is used to generate longer duration rectangular pulses in smaller length. The HPFL inner conductor is made up of 13 turns of SS-304 strip, 39.5 mm wide and 0.5 mm thick wounded on the 168 mm delrin cylinder. The impedance of the HPFL is 22 Ω. The 2 turns at the input side of the HPFL are wounded with ethylene propylene rubber tape on the strip. The HPFL is charged to 180 kV in 4 μs and discharges into a matched load through a spark switch. It generates two flat top rectangular pulses of 90 kV, 100 ns duration with the 30 ns interval between the pulses. The system can be used as fast double pulse source for repetitive pulsed power loads.

  15. The Ranchero explosive pulsed power system

    SciTech Connect

    Goforth, J.H.; Atchison, W.L.; Bartram, D.E.

    1997-09-01

    The authors are currently developing a high explosive pulsed power system concept that they call Ranchero. Ranchero systems consist of series-parallel combinations of simultaneously initiated coaxial magnetic flux compression generators, and are intended to operate in the range from 50 MA to a few hundred MA currents. One example of a Ranchero system is shown here. The coaxial modules lend themselves to extracting the current output either from one end or along the generator midplane. They have previously published design considerations related to the different module configurations, and in this paper they concentrate on the system that they will use for their first imploding liner tests. A single module with end output. The module is 1.4-m long and expands the armature by a factor of two to reach the 30-cm OD stator. The first heavy liner implosion experiments will be conducted in the range of 40--50 MA currents. Electrical tests, to date, have employed high explosive (HE) charges 43-cm long. They have performed tests and related 1D MHD calculations at the 45-MA current level with small loads. From these results, they determine that they can deliver currents of approximately 50 MA to loads of 8 nH.

  16. A compact, high-voltage pulsed charging system based on an air-core pulse transformer.

    PubMed

    Zhang, Tianyang; Chen, Dongqun; Liu, Jinliang; Liu, Chebo; Yin, Yi

    2015-09-01

    Charging systems of pulsed power generators on mobile platforms are expected to be compact and provide high pulsed power, high voltage output, and high repetition rate. In this paper, a high-voltage pulsed charging system with the aforementioned characteristics is introduced, which can be applied to charge a high-voltage load capacitor. The operating principle of the system and the technical details of the components in the system are described in this paper. The experimental results show that a 600 nF load capacitor can be charged to 60 kV at 10 Hz by the high-voltage pulsed charging system for a burst of 0.5 s. The weight and volume of the system are 60 kg and 600 × 500 × 380 mm(3), respectively.

  17. A compact, high-voltage pulsed charging system based on an air-core pulse transformer

    NASA Astrophysics Data System (ADS)

    Zhang, Tianyang; Chen, Dongqun; Liu, Jinliang; Liu, Chebo; Yin, Yi

    2015-09-01

    Charging systems of pulsed power generators on mobile platforms are expected to be compact and provide high pulsed power, high voltage output, and high repetition rate. In this paper, a high-voltage pulsed charging system with the aforementioned characteristics is introduced, which can be applied to charge a high-voltage load capacitor. The operating principle of the system and the technical details of the components in the system are described in this paper. The experimental results show that a 600 nF load capacitor can be charged to 60 kV at 10 Hz by the high-voltage pulsed charging system for a burst of 0.5 s. The weight and volume of the system are 60 kg and 600 × 500 × 380 mm3, respectively.

  18. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ultrasonic pulsed doppler imaging system. 892.1550 Section 892.1550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... system. (a) Identification. An ultrasonic pulsed doppler imaging system is a device that combines...

  19. 21 CFR 892.1560 - Ultrasonic pulsed echo imaging system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ultrasonic pulsed echo imaging system. 892.1560 Section 892.1560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... system. (a) Identification. An ultrasonic pulsed echo imaging system is a device intended to project...

  20. 21 CFR 892.1560 - Ultrasonic pulsed echo imaging system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ultrasonic pulsed echo imaging system. 892.1560 Section 892.1560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... system. (a) Identification. An ultrasonic pulsed echo imaging system is a device intended to project...

  1. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ultrasonic pulsed doppler imaging system. 892.1550 Section 892.1550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... system. (a) Identification. An ultrasonic pulsed doppler imaging system is a device that combines...

  2. Ultrashort-pulse laser system for hard dental tissue procedures

    NASA Astrophysics Data System (ADS)

    Neev, Joseph; Da Silva, Luiz B.; Feit, Michael D.; Perry, Michael D.; Rubenchik, Alexander M.; Stuart, Brent C.

    1996-04-01

    In spite of intensive research, lasers have not replaced conventional tools in many hard tissue applications. Ultrashort pulse lasers offer several advantages in their highly per-pulse-efficient operation, negligible thermal and mechanical damage and low noise operation. Possible development of optimal laser systems to replace the high-speed dental drill is discussed. Applications of ultrashort pulse systems for dental procedures are outlined. Selection criteria and critical parameters are considered, and are compared to the conventional air-turbine drill and to long and short pulsed systems.

  3. Optical pulse generation system for the National Ignition Facility (NIF)

    SciTech Connect

    Penko, F; Braucht,; Browning, D; Crane, J K; Dane, B; Deadrick, F; Dreifuerst, G; Henesian, M; Jones, B A; Kot, L; Laumann, C; Martinez, M; Moran, B; Rothenberg, J E; Skulina, K; Wilcox, R B

    1998-06-18

    We describe the Optical Pulse Generation (OPG) system for the National Ignition Facility ( NIF ). The OPG system begins with the Master Oscillator Room ( MOR ) where the initial, seed pulse for the entire laser system is produced and properly formatted to enhance ignition in the target. The formatting consists of temporally shaping the pulse and adding additional bandwidth to increase the coupling of the laser generated x-rays to the high density target plasma. The pulse produced in the MOR fans out to 48 identical preamplifier modules where it is amplified by a factor of ten billion and spatially shaped for injection into the 192 main amplifier chai

  4. Effect of Pulse Width on Ozone Yield using Inductive Energy Storage System Pulsed Power Generator

    NASA Astrophysics Data System (ADS)

    Yagi, Ippei; Mukaigawa, Seiji; Takaki, Koichi; Fujiwara, Tamiya; Go, Tomio

    Nanosecond pulse voltages of several pulse widths were applied to a cylindrical plasma reactor for ozone synthesis with high energy yield. Nanoseconds pulse voltages were produced by inductive energy storage system pulsed power generators using semiconductor opening switch (SOS) diodes. First recovery diodes were used as SOS diodes in the inductive energy storage system to produce short-pulsed high voltage with high-repetition rate. The short pulse voltage of 9.5 ns width and 33 kV peak voltage was produced at charging voltage of 15 kV and was applied to a 1 mm diameter center wire electrode in the plasma reactor. The copper cylinder of 19 mm inner diameter was used as outer electrode and was connected to a ground. The ozone yield of 271 g/kWh was obtained using the 9.5 ns width pulse voltage at synthesized 412 ppm of ozone concentration. The yield 271 g/kWh was more than twice as much as the yield 114 g/kWh at 401 ppm using a 60 ns pulse voltage.

  5. Pulse Detonation Engine Air Induction System Analysis

    NASA Technical Reports Server (NTRS)

    Pegg, R. J.; Hunter, L. G.; Couch, B. D.

    1996-01-01

    A preliminary mixed-compression inlet design concept for potential pulse-detonation engine (PDE) powered supersonic aircraft was defined and analyzed. The objectives of this research were to conceptually design and integrate an inlet/PDE propulsion system into a supersonic aircraft, perform time-dependent CFD analysis of the inlet flowfield, and to estimate the installed PDE cycle performance. The study was baselined to a NASA Mach 5 Waverider study vehicle in which the baseline over/under turboramjet engines were replaced with a single flowpath PDE propulsion system. As much commonality as possible was maintained with the baseline configuration, including the engine location and forebody lines. Modifications were made to the inlet system's external ramp angles and a rotating cowl lip was incorporated to improve off-design inlet operability and performance. Engines were sized to match the baseline vehicle study's ascent trajectory thrust requirement at Mach 1.2. The majority of this study was focused on a flight Mach number of 3.0. The time-dependent Navier Stokes CFD analyses of a two-dimensional approximation of the inlet was conducted for the Mach 3.0 condition. The Lockheed Martin Tactical Aircraft Systems-developed FALCON CFD code with a two equation 'k-1' turbulence model was used. The downstream PDE was simulated by an array of four sonic nozzles in which the flow areas were rapidly varied in various opening/closing combinations. Results of the CFD study indicated that the inlet design concept operated successfully at the Mach 3.0 condition, satisfying mass capture, total pressure recovery, and operability requirements. Time-dependent analysis indicated that pressure and expansion waves from the simulated valve perturbations did not effect the inlet's operability or performance.

  6. Successful management of lower-pole moiety ureteropelvic junction obstruction in a partially duplicated collecting system using minimally invasive retrograde endoscopic techniques.

    PubMed

    Bruno, D; Delvecchio, F C; Preminger, G M

    2000-11-01

    Although the true incidence of ureteropelvic junction (UPJ) obstruction in the lower-pole moiety of an incompletely duplicated renal collecting system remains elusive, the description of this entity in the published literature is exceedingly rare. To our knowledge, we report the first case of this entity managed successfully by ureteroscopic holmium laser incision of the stenotic UPJ segment. This case underscores the utility of minimally invasive techniques in the management of selected cases of UPJ obstruction associated with a partially duplicated collecting system.

  7. Control System for the LLNL Kicker Pulse Generator

    SciTech Connect

    Watson, J A; Anaya, R M; Cook, E G; Lee, B S; Hawkins, S A

    2002-06-18

    A solid-state high voltage pulse generator with multi-pulse burst capability, very fast rise and fall times, pulse width agility, and amplitude modulation capability for use with high speed electron beam kickers has been designed and tested at LLNL. A control system calculates a desired waveform to be applied to the kicker based on measured electron beam displacement then adjusts the pulse generators to provide the desired waveform. This paper presents the design of the control system and measure performance data from operation on the ETA-11 accelerator at LLNL.

  8. Spatial and spectral effects in subcritical system pulsed experiments

    SciTech Connect

    Dulla, S.; Nervo, M.; Ravetto, P.; Carta, M.

    2013-07-01

    Accurate neutronic models are needed for the interpretation of pulsed experiments in subcritical systems. In this work, the extent of spatial and spectral effects in the pulse propagation phenomena is investigated and the analysis is applied to the GUINEVERE experiment. The multigroup cross section data is generated by the Monte Carlo SERPENT code and the neutronic evolution following the source pulse is simulated by a kinetic diffusion code. The results presented show that important spatial and spectral aspects need to be properly accounted for and that a detailed energy approach may be needed to adequately capture the physical features of the system to the pulse injection. (authors)

  9. Spatial and temporal pulse propagation for dispersive paraxial optical systems

    SciTech Connect

    Marcus, G.

    2016-04-01

    The formalism for pulse propagation through dispersive paraxial optical systems first presented by Kostenbauder (IEEE J. Quant. Elec. 261148–1157 (1990)) using 4 × 4 ray-pulse matrices is extended to 6 × 6 matrices and includes non-separable spatial-temporal couplings in both transverse dimensions as well as temporal dispersive effects up to a quadratic phase. The eikonal in a modified Huygens integral in the Fresnell approximation is derived and can be used to propagate pulses through complicated dispersive optical systems within the paraxial approximation. Additionally, a simple formula for the propagation of ultrashort pulses having a Gaussian profile both spatially and temporally is presented.

  10. Nox reduction system utilizing pulsed hydrocarbon injection

    DOEpatents

    Brusasco, Raymond M.; Penetrante, Bernardino M.; Vogtlin, George E.; Merritt, Bernard T.

    2001-01-01

    Hydrocarbon co-reductants, such as diesel fuel, are added by pulsed injection to internal combustion engine exhaust to reduce exhaust NO.sub.x to N.sub.2 in the presence of a catalyst. Exhaust NO.sub.x reduction of at least 50% in the emissions is achieved with the addition of less than 5% fuel as a source of the hydrocarbon co-reductants. By means of pulsing the hydrocarbon flow, the amount of pulsed hydrocarbon vapor (itself a pollutant) can be minimized relative to the amount of NO.sub.x species removed.

  11. Some perspectives on pulse detonation propulsion systems

    NASA Astrophysics Data System (ADS)

    Lu, F. K.; Wilson, D. R.

    Pulse detonation engines and rockets (PDE/Rs) can potentially revolutionize air breathing and rocket propulsion [1-6]. While the PDE concept is over five decades old, it has recently enjoyed renewed interest, due mostly to theoretical and computational studies indicating high cycle efficiencies. When modeled by a constant volume, Humphrey cycle, the detonation engine is found to be superior to that of existing constant pressure, Brayton cycles, with claims of as much as 10-40% improvement in specific impulse [4,7-9]. The constant volume process is derived from the Zeldovich-von Neumann-Döring (ZND) model of the detonation wave as a high strength shock wave, followed by a region of chemical reaction and a subsequent isentropic rarefaction. Amongst other advantages of the PDE is simplicity, where the PDE is easy to manufacture and requires few moving parts, with the possibility of eliminating high-pressure pumps in rocket applications, or reducing turbomachinery stages in air-breathing propulsion systems.

  12. A pulse system for spectrum analysis of magnetoelastic biosensors

    NASA Astrophysics Data System (ADS)

    Shen, Wen; Mathison, Leslie C.; Petrenko, Valery A.; Chin, Bryan A.

    2010-04-01

    In this paper, a pulse system is reported whereby it is possible to detect concentrations of bacteria using small magnetoelastic biosensors. The system also allows detection using multiple sensors, where a control sensor can be used to compensate for environmental variables. This system removes the bias magnetic field and thus eliminates an error source. An equation is derived to describe the mechanical vibration of a sensor in a pulse system. Both frequency domain and time domain signals were studied to determine the optimum pulse power. The system was verified with a control sensor and a detection sensor to detect bacteria.

  13. Phase Noise Comparision of Short Pulse Laser Systems

    SciTech Connect

    S. Zhang; S. V. Benson; J. Hansknecht; D. Hardy; G. Neil; Michelle D. Shinn

    2006-12-01

    This paper describes the phase noise measurement on several different mode-locked laser systems that have completely different gain media and configurations including a multi-kW free-electron laser. We will focus on the state of the art short pulse lasers, especially the drive lasers for photocathode injectors. A comparison between the phase noise of the drive laser pulses, electron bunches and FEL pulses will also be presented.

  14. System and process for pulsed multiple reaction monitoring

    DOEpatents

    Belov, Mikhail E

    2013-05-17

    A new pulsed multiple reaction monitoring process and system are disclosed that uses a pulsed ion injection mode for use in conjunction with triple-quadrupole instruments. The pulsed injection mode approach reduces background ion noise at the detector, increases amplitude of the ion signal, and includes a unity duty cycle that provides a significant sensitivity increase for reliable quantitation of proteins/peptides present at attomole levels in highly complex biological mixtures.

  15. Compact pulsed electron beam system for microwave generation

    NASA Astrophysics Data System (ADS)

    Sharma, S. K.; Deb, P.; Shukla, R.; Banerjee, P.; Prabaharan, T.; Adhikary, B.; Verma, R.; Sharma, A.; Shyam, A.

    2012-11-01

    A compact 180 kV electron beam system is designed for high power microwave generation. The electron beam system is consists of a secondary energy storage device, which can deliver energy to the load at faster rate than usual primary energy storage system such as tesla transformers or marx generator. The short duration, high voltage pulse with fast rise time and good flattop is applied to vacuum diode for high power microwave generation. The compact electron beam system is made up of single turn primary tesla transformer which charges a helical pulse forming line and transfers its energy to vacuum diode through a high voltage pressurized spark gap switch. We have used helical pulse forming line which has higher inductance as compared to coaxial pulse forming line, which in turns increases, the pulse width and reduce the length of the pulse forming line. Water dielectric medium is used because of its high dielectric constant, high dielectric strength and efficient energy storage capability. The time dependent breakdown property and high relative permittivity of water makes it an ideal choice for this system. The high voltage flat-top pulse of 90 kV, 260 ns is measured across the matched load. In this article we have reported the design details, simulation and initial experimental results of 180 kV pulsed electron beam system for high power microwave generation.

  16. Enhancement of beam pulse controllability for a single-pulse formation system of a cyclotron

    SciTech Connect

    Kurashima, Satoshi Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Okumura, Susumu; Taguchi, Mitsumasa; Fukuda, Mitsuhiro

    2015-07-15

    The single-pulse formation technique using a beam chopping system consisting of two types of high-voltage beam kickers was improved to enhance the quality and intensity of the single-pulse beam with a pulse interval over 1 μs at the Japan Atomic Energy Agency cyclotron facility. A contamination rate of neighboring beam bunches in the single-pulse beam was reduced to less than 0.1%. Long-term purification of the single pulse beam was guaranteed by the well-controlled magnetic field stabilization system for the cyclotron magnet. Reduction of the multi-turn extraction number for suppressing the neighboring beam bunch contamination was achieved by restriction of a beam phase width and precise optimization of a particle acceleration phase. In addition, the single-pulse beam intensity was increased by a factor of two or more by a combination of two types of beam bunchers using sinusoidal and saw-tooth voltage waveforms. Provision of the high quality intense single-pulse beam contributed to improve the accuracy of experiments for investigation of scintillation light time-profile and for neutron energy measurement by a time-of-flight method.

  17. 48 CFR 1331.205-70 - Duplication of effort.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Duplication of effort....205-70 Duplication of effort. The Department will not pay any costs for work that is duplicative of..., Duplication of Effort, in all cost-reimbursement, time and materials, and labor hour solicitations...

  18. Traveling pulse on a periodic background in parametrically driven systems.

    PubMed

    León, Alejandro O; Clerc, Marcel G; Coulibaly, Saliya

    2015-05-01

    Macroscopic systems with dissipation and time-modulated injection of energy, parametrically driven systems, can self-organize into localized states and/or patterns. We investigate a pulse that travels over a one-dimensional pattern in parametrically driven systems. Based on a minimal prototype model, we show that the pulses emerge through a subcritical Andronov-Hopf bifurcation of the underlying pattern. We describe a simple physical system, a magnetic wire forced with a transverse oscillatory magnetic field, which displays these traveling pulses.

  19. Synchronous pulse generation in a multicavity fiber laser system

    NASA Astrophysics Data System (ADS)

    Gómez-Pavón, L. C.; Martí-Panameño, E.; Gómez-de la Fuente, O.; Luis-Ramos, A.

    2006-09-01

    We report the experimental synchronous pulse generation in a multicavity fiber laser system with two Erbium-doped fiber laser cavities. We have demonstrated that through the evanescent fields interaction between one cavity with active modulation and other one in continuous wave it is possible to generate more intense pulses in both cavities. Moreover, the synchronous pulse generation between cavities is achieved with an appropriate selection of pump intensity, modulation frequency and coupling ratio. We found that the pulse intensity is 2.5 times greater and the pulse duration lowers than a single Erbium-doper fiber laser. Furthermore, by means of the synchronous diagram we determined the synchronization strength in temporal pulse emission between cavities.

  20. Synchronization using pulsed edge tracking in optical PPM communication system

    NASA Technical Reports Server (NTRS)

    Gagliardi, R.

    1972-01-01

    A pulse position modulated (PPM) optical communication system using narrow pulses of light for data transmission requires accurate time synchronization between transmitter and receiver. The presence of signal energy in the form of optical pulses suggests the use of a pulse edge tracking method of maintaining the necessary timing. The edge tracking operation in a binary PPM system is examined, taking into account the quantum nature of the optical transmissions. Consideration is given first to pure synchronization using a periodic pulsed intensity, then extended to the case where position modulation is present and auxiliary bit decisioning is needed to aid the tracking operation. Performance analysis is made in terms of timing error and its associated statistics. Timing error variances are shown as a function of system signal to noise ratio.

  1. 21 CFR 892.1560 - Ultrasonic pulsed echo imaging system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ultrasonic pulsed echo imaging system. 892.1560 Section 892.1560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1560 Ultrasonic pulsed echo...

  2. 21 CFR 892.1560 - Ultrasonic pulsed echo imaging system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ultrasonic pulsed echo imaging system. 892.1560 Section 892.1560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1560 Ultrasonic pulsed echo...

  3. 21 CFR 892.1560 - Ultrasonic pulsed echo imaging system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultrasonic pulsed echo imaging system. 892.1560 Section 892.1560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1560 Ultrasonic pulsed echo...

  4. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ultrasonic pulsed doppler imaging system. 892.1550 Section 892.1550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1550 Ultrasonic pulsed doppler...

  5. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ultrasonic pulsed doppler imaging system. 892.1550 Section 892.1550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1550 Ultrasonic pulsed doppler imaging...

  6. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultrasonic pulsed doppler imaging system. 892.1550 Section 892.1550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1550 Ultrasonic pulsed doppler imaging...

  7. Experimental investigation of an explosive-driven pulse power system

    SciTech Connect

    Tucker, T.J.; Hanson, D.L.; Cnare, E.C.

    1983-01-01

    The results obtained in the test of a pulse-power system composed of an explosively driven compressed magnetic-field current generator driving an explosive opening switch and a 20 nH inductive load are presented. It is shown that microsecond risetime, multimegampere current pulses can be produced by this technique.

  8. Power limitations and pulse distortions in an Yb : KGW chirped-pulse amplification laser system

    SciTech Connect

    Kim, G H; Yang, J; Kulik, A V; Sall, E G; Chizhov, S A; Kang, U; Yashin, V E

    2013-08-31

    We have studied self-action effects (self-focusing and self-phase modulation) and stimulated Raman scattering in an Yb : KGW chirped-pulse amplification laser system. The results demonstrate that self-focusing in combination with thermal lensing may significantly limit the chirped pulse energy in this system (down to 200 μJ) even at a relatively long pulse duration (50 ps). Nonlinear lenses in the laser crystals in combination with thermal lenses bring the regenerative amplifier cavity in the laser system to the instability zone and limit the average output power at pulse repetition rates under 50 kHz. Self-phase modulation, a manifestation of self-action, may significantly distort a recompressed femtosecond pulse at energies near the self-focusing threshold. Stimulated Raman scattering in such a laser has a weaker effect on output parameters than do self-focusing and thermal lensing, and Raman spectra are only observed in the case of pulse energy instability. (nonlinear optical phenomena)

  9. Short pulse generation and high speed communication system

    NASA Astrophysics Data System (ADS)

    Fan, Honglei

    Ultrahigh-speed optical time-division-multiplexing (TDM) transmission technologies are essential to construct ultrahigh-speed all-optical networks needed in the multimedia era. In order to realize high-speed optical TDM systems, ultra-short pulses should be generated. In this dissertation, the gain switching and mode locking techniques have been analyzed and used to produce ultra- short pulses. Gain-switched pulses with a width of ~18ps have been obtained. The theoretical analysis on gain-switching phenomena has been carried out. A new approach for the simulation of the spectrum of a gain- switched laser has been developed. The principle of mode locking has been discussed. ~6.5ps, pulses have been obtained from a monolithic mode-locked distributed Bragg reflector (DBR) laser, which are the shortest pulses from the actively mode- locked DBR lasers as we know. ~1.1ps pulses have been achieved from a colliding-pulse mode-locked (CPM) laser. The operation principle of CPM lasers has been discussed. Pulse compression using dispersion-compensating fiber has been applied in order to get shorter pulses. The semiconductor optical amplifier (SOA) plays a very important role in TDM systems. The cross gain modulation (XGM) measurements on a 2-section SOA, using both cw and pulsed pump and probe beams, have been performed. A theoretical analysis has been carried out. Wavelength conversion and fiber transmission experiments have been achieved at different bit rates. The basic idea of TDM system has been discussed. Multiplexing has been achieved using fibers. Demulitplexing has been demonstrated using XGM in SOA, four-wave mixing (FWM) in SOA, and cascaded modulators. The operation principles have been discussed in detail. The FWM experiments between two optical pulses have been performed.

  10. Plant Genome Duplication Database.

    PubMed

    Lee, Tae-Ho; Kim, Junah; Robertson, Jon S; Paterson, Andrew H

    2017-01-01

    Genome duplication, widespread in flowering plants, is a driving force in evolution. Genome alignments between/within genomes facilitate identification of homologous regions and individual genes to investigate evolutionary consequences of genome duplication. PGDD (the Plant Genome Duplication Database), a public web service database, provides intra- or interplant genome alignment information. At present, PGDD contains information for 47 plants whose genome sequences have been released. Here, we describe methods for identification and estimation of dates of genome duplication and speciation by functions of PGDD.The database is freely available at http://chibba.agtec.uga.edu/duplication/.

  11. Optimized pulse sequences for suppressing unwanted transitions in quantum systems

    SciTech Connect

    Schroeder, C. A.; Agarwal, G. S.

    2011-01-15

    We investigate the nature of the pulse sequence so that unwanted transitions in quantum systems can be inhibited optimally. For this purpose we show that the sequence of pulses proposed by Uhrig [Phys. Rev. Lett. 98, 100504 (2007)] in the context of inhibition of environmental dephasing effects is optimal. We derive exact results for inhibiting the transitions and confirm the results numerically. We posit a very significant improvement by usage of the Uhrig sequence over an equidistant sequence in decoupling a quantum system from unwanted transitions. The physics of inhibition is the destructive interference between transition amplitudes before and after each pulse.

  12. Megahertz pulse-burst alexandrite laser diagnostic systems

    NASA Astrophysics Data System (ADS)

    Luff, Jon David

    Megahertz pulse-burst laser systems coupled with megahertz-rate framing cameras have proven (over the last ten years) to be very robust in imaging of high-speed reacting and nonreacting supersonic flows. These Nd:YAG systems produce 20--30 pulses (at variable rates from 500 kHz to 1 MHz) with 50--100 mJ/pulse (lambda = 1064nm) and have been used with narrow, spectral-linewidth, iodine, atomic filters to image turbulence in supersonic boundary layers with great success (when operating at lambda = 532nm). To extend this pulse-burst capability at other wavelengths (wavelengths outside of the 5--30 GHz tuning range of Nd:YAG: lambda = 1064 nm fundamental, and lambda = 532 nm second harmonic), two unique, tunable, megahertz-rate alexandrite laser systems were designed and built. This dissertation documents these two systems and discusses the potential for tunable, megahertz, pulse-burst systems that have more tuning range than Nd:YAG. These tunable alexandrite systems substantially extend the wavelength range of pulse-burst laser technology, but, to date, have pulse-energy limitations. Tunable from 710 nm to 800 nm (in the fundamental), these lasers provide researchers one laser to reach multiple molecular or atomic resonances with variable pulse-burst pulse separations. The molecular and atomic species of interest in reacting and nonreacting flows are presented in Chapter 1, providing a road-map for the development of these tunable lasers. This dissertation presents the design and development of these systems, including mode control, Herriott cell design for pulse separation, and the megahertz-tuning ringmaster-oscillator. Chapter 2 covers the physics of alexandrite as a solid-state, lamp-pumped, tunable medium and compares it to the tunability of Ti:sapphire. Chapter 3 and 4 present the pulse-burst alexandrite systems. The first system, built in Princeton's Applied Physics group (PAPG) (Chapter 3), produced 1-5 mJ total pulse-packet energy of 20--30 pulses, or

  13. Effective specific impulse of external nuclear pulse propulsion systems

    NASA Technical Reports Server (NTRS)

    Reynolds, T. W.

    1972-01-01

    An investigation of a simple self-similar flow model for an external nuclear pulse propulsion system indicates that to achieve the high effective specific impulse of such a system three principal factors are required. The are (1) attaining pulses of optimum energy, (2) attaining good propellant collimation, and (3) using an ablative material for the pusher surface which has high absorptivity for radiant energy at the propellant stagnation temperature.

  14. Ship To Ship Pulse Recognition System

    DTIC Science & Technology

    1941-10-24

    co. !. icting Mnd A to non-com+uctin;. It is, of coure, necessary that the tripping pulse have a pulse width less t!an the time constant of t1e...in Grich otaie. b’r n-ws a !wuýLlo-throw switcEl, th cleio~.ut -ivc! anism rnAY be coiriccto: to t..e a; ,rn: riate elt ’-irt !%C’ oit.’-r t--* in r...of the ’:vrer-r-co,-rir-.r wt.Lý te;: ve-s e.-o elt *.or to an incorr.,c: #-.ýr.v-ittod co~ant or to ;-r~-atirv, actIIIL. of #,f 11-etronie Wnitchen cr

  15. Viewing zone duplication of multi-projection 3D display system using uniaxial crystal.

    PubMed

    Lee, Chang-Kun; Park, Soon-Gi; Moon, Seokil; Lee, Byoungho

    2016-04-18

    We propose a novel multiplexing technique for increasing the viewing zone of a multi-view based multi-projection 3D display system by employing double refraction in uniaxial crystal. When linearly polarized images from projector pass through the uniaxial crystal, two possible optical paths exist according to the polarization states of image. Therefore, the optical paths of the image could be changed, and the viewing zone is shifted in a lateral direction. The polarization modulation of the image from a single projection unit enables us to generate two viewing zones at different positions. For realizing full-color images at each viewing zone, a polarization-based temporal multiplexing technique is adopted with a conventional polarization switching device of liquid crystal (LC) display. Through experiments, a prototype of a ten-view multi-projection 3D display system presenting full-colored view images is implemented by combining five laser scanning projectors, an optically clear calcite (CaCO3) crystal, and an LC polarization rotator. For each time sequence of temporal multiplexing, the luminance distribution of the proposed system is measured and analyzed.

  16. High Average Power, High Energy Short Pulse Fiber Laser System

    SciTech Connect

    Messerly, M J

    2007-11-13

    Recently continuous wave fiber laser systems with output powers in excess of 500W with good beam quality have been demonstrated [1]. High energy, ultrafast, chirped pulsed fiber laser systems have achieved record output energies of 1mJ [2]. However, these high-energy systems have not been scaled beyond a few watts of average output power. Fiber laser systems are attractive for many applications because they offer the promise of high efficiency, compact, robust systems that are turn key. Applications such as cutting, drilling and materials processing, front end systems for high energy pulsed lasers (such as petawatts) and laser based sources of high spatial coherence, high flux x-rays all require high energy short pulses and two of the three of these applications also require high average power. The challenge in creating a high energy chirped pulse fiber laser system is to find a way to scale the output energy while avoiding nonlinear effects and maintaining good beam quality in the amplifier fiber. To this end, our 3-year LDRD program sought to demonstrate a high energy, high average power fiber laser system. This work included exploring designs of large mode area optical fiber amplifiers for high energy systems as well as understanding the issues associated chirped pulse amplification in optical fiber amplifier systems.

  17. [Dynamic Pulse Signal Processing and Analyzing in Mobile System].

    PubMed

    Chou, Yongxin; Zhang, Aihua; Ou, Jiqing; Qi, Yusheng

    2015-09-01

    In order to derive dynamic pulse rate variability (DPRV) signal from dynamic pulse signal in real time, a method for extracting DPRV signal was proposed and a portable mobile monitoring system was designed. The system consists of a front end for collecting and wireless sending pulse signal and a mobile terminal. The proposed method is employed to extract DPRV from dynamic pulse signal in mobile terminal, and the DPRV signal is analyzed both in the time domain and the frequency domain and also with non-linear method in real time. The results show that the proposed method can accurately derive DPRV signal in real time, the system can be used for processing and analyzing DPRV signal in real time.

  18. Diversifying crop rotations with pulses enhances system productivity

    PubMed Central

    Gan, Yantai; Hamel, Chantal; O’Donovan, John T.; Cutforth, Herb; Zentner, Robert P.; Campbell, Con A.; Niu, Yining; Poppy, Lee

    2015-01-01

    Agriculture in rainfed dry areas is often challenged by inadequate water and nutrient supplies. Summerfallowing has been used to conserve rainwater and promote the release of nitrogen via the N mineralization of soil organic matter. However, summerfallowing leaves land without any crops planted for one entire growing season, creating lost production opportunity. Additionally, summerfallowing has serious environmental consequences. It is unknown whether alternative systems can be developed to retain the beneficial features of summerfallowing with little or no environmental impact. Here, we show that diversifying cropping systems with pulse crops can enhance soil water conservation, improve soil N availability, and increase system productivity. A 3-yr cropping sequence study, repeated for five cycles in Saskatchewan from 2005 to 2011, shows that both pulse- and summerfallow-based systems enhances soil N availability, but the pulse system employs biological fixation of atmospheric N2, whereas the summerfallow-system relies on ‘mining’ soil N with depleting soil organic matter. In a 3-yr cropping cycle, the pulse system increased total grain production by 35.5%, improved protein yield by 50.9%, and enhanced fertilizer-N use efficiency by 33.0% over the summerfallow system. Diversifying cropping systems with pulses can serve as an effective alternative to summerfallowing in rainfed dry areas. PMID:26424172

  19. Microscopic Faraday rotation measurement system using pulsed magnetic fields.

    PubMed

    Egami, Shigeki; Watarai, Hitoshi

    2009-09-01

    Microscopic Faraday rotation measurement system using a pulsed magnetic field has been constructed, which can be applied to micron sized diamagnetic and paramagnetic materials. A pulsed magnetic coil could generate a maximum magnetic flux density of about 12 T. The performance of the microscopic Faraday rotation apparatus was demonstrated by the measurement of the Verdet constant V of a polystyrene particle, after the calibration of the pulsed magnetic flux density using a glass plate as a standard material. Also, the magneto-optical rotation dispersion of some diamagnetic substances have been measured and analyzed with V=alambda(-2)+b. The values of a and b were compared to their magnetic susceptibilities.

  20. Pulse

    MedlinePlus

    ... the underside of the opposite wrist, below the base of the thumb. Press with flat fingers until ... determine if the patient's heart is pumping. Pulse measurement has other uses as well. During or immediately ...

  1. Low power pulsed MPD thruster system analysis and applications

    NASA Technical Reports Server (NTRS)

    Myers, Roger M.; Domonkos, Matthew; Gilland, James H.

    1993-01-01

    Pulsed magnetoplasmadynamic (MPD) thruster systems were analyzed for application to solar-electric orbit transfer vehicles at power levels ranging from 10 to 40 kW. Potential system level benefits of pulsed propulsion technology include ease of power scaling without thruster performance changes, improved transportability from low power flight experiments to operational systems, and reduced ground qualification costs. Required pulsed propulsion system components include a pulsed applied-field MPD thruster, a pulse-forming network, a charge control unit, a cathode heater supply, and high speed valves. Mass estimates were obtained for each propulsion subsystem and spacecraft component using off-the-shelf technology whenever possible. Results indicate that for payloads of 1000 and 2000 kg pulsed MPD thrusters can reduce launch mass by between 1000 and 2500 kg over those achievable with hydrogen arcjets, which can be used to reduce launch vehicle class and the associated launch cost. While the achievable mass savings depends on the trip time allowed for the mission, cases are shown in which the launch vehicle required for a mission is decreased from an Atlas IIAS to an Atlas I or Delta 7920.

  2. Programmable Pulse Generator for Aditya Gas Puffing System

    NASA Astrophysics Data System (ADS)

    Patel, Narendra; Chavda, Chhaya; Bhatt, S. B.; Chattopadhyay, Prabal; Saxena, Y. C.

    2012-11-01

    In the Aditya Tokamak, one of primary requirement for plasma generation is to feed the required quantity of the fuel gas prior to plasma shot. Gas feed system mainly consists of piezoelectric gas leak valve and gas reservoir. The Hydrogen gas is prior to 300ms loop voltage for the duration of 4 msec to 7 msec. Gas is puffed during the shot for required plasma parameters and to increase plasma density using the same system. The valve is controlled by either continuous voltage or pulses of different width, amplitude and delay with respect to loop voltage. These voltage pulses are normally applied through standard pulse generator. The standard pulse generator is replaced by micro controller based in housed developed programmable pulse generator system consists of in built power supply, BNC input for external trigger, BNC output and serial interface. This programmable pulse generator is successfully tested and is in operation for gas puffing during ADITYA Tokamak experiments. The paper discusses the design and development aspect of the system.

  3. Low power pulsed MPD thruster system analysis and applications

    NASA Technical Reports Server (NTRS)

    Myers, Roger M.; Domonkos, Matthew; Gilland, James H.

    1993-01-01

    Pulsed MPD thruster systems were analyzed for application to solar-electric orbit transfer vehicles at power levels ranging from 10 to 40 kW. Potential system level benefits of pulsed propulsion technology include ease of power scaling without thruster performance changes, improved transportability from low power flight experiments to operational systems, and reduced ground qualification costs. Required pulsed propulsion system components include a pulsed applied-field MPD thruster, a pulse-forming network, a charge control unit, a cathode heater supply, and high speed valves. Mass estimates were obtained for each propulsion subsystem and spacecraft component. Results indicate that for payloads of 1000 and 2000 kg, pulsed MPD thrusters can reduce launch mass by between 1000 and 2500 kg relative to hydrogen arcjets, reducing launch vehicle class and launch cost. While the achievable mass savings depends on the trip time allowed for the mission, cases are shown in which the launch vehicle required for a mission is decreased from an Atlas IIAS to an Atlas I or Delta 7920.

  4. Spatial and temporal pulse propagation for dispersive paraxial optical systems

    DOE PAGES

    Marcus, G.

    2016-04-01

    The formalism for pulse propagation through dispersive paraxial optical systems first presented by Kostenbauder (IEEE J. Quant. Elec. 261148–1157 (1990)) using 4 × 4 ray-pulse matrices is extended to 6 × 6 matrices and includes non-separable spatial-temporal couplings in both transverse dimensions as well as temporal dispersive effects up to a quadratic phase. The eikonal in a modified Huygens integral in the Fresnell approximation is derived and can be used to propagate pulses through complicated dispersive optical systems within the paraxial approximation. Additionally, a simple formula for the propagation of ultrashort pulses having a Gaussian profile both spatially and temporallymore » is presented.« less

  5. Decrease of pulse-contrast in nonlinear chirped-pulse amplification systems due to high-frequency spectral phase ripples.

    PubMed

    Schimpf, Damian; Seise, Enrico; Limpert, Jens; Tünnermann, Andreas

    2008-06-09

    It is analytically shown that weak initial spectral phase modulations cause a pulse-contrast degradation at the output of nonlinear chirped-pulse amplification systems. The Kerr-nonlinearity causes an energy-transfer from the main pulse to side-pulses during nonlinear amplification. The relative intensities of these side-pulses can be described in terms of Bessel-functions. It is shown that the intensities of the pulses are dependent on the magnitude of the accumulated nonlinear phase-shift (i.e., the B-integral), the depth and period of the initial spectral phase-modulation and the slope of the linear stretching chirp. The results are applicable to any type of laser amplifier that is based on the technique of chirped-pulse amplification. The analytical results presented in this paper are of particular importance for high peak-power laser applications requiring high pulse-contrasts, e.g. high field physics.

  6. Arterial pulse system: modern methods for traditional Indian medicine.

    PubMed

    Joshi, Aniruddha; Chandran, Sharat; Jayaraman, V K; Kulkarni, B D

    2007-01-01

    Ayurveda is one of the most comprehensive healing systems in the world and has classified the body system according to the theory of Tridosha to overcome ailments. Diagnosis similar to the traditional pulse-based method requires a system of clean input signals, and extensive experiments for obtaining classification features. In this paper we briefly describe our system of generating pulse waveforms and use various feature detecting methods to show that an arterial pulse contains typical physiological properties. The beat-to-beat variability is captured using a complex B-spline mother wavelet based peak detection algorithm. We also capture--to our knowledge for the first time--the self-similarity in the physiological signal, and quantifiable chaotic behavior using recurrence plot structures.

  7. Chromosomal duplications in bacteria, fruit flies, and humans

    SciTech Connect

    Lupski, J.R.; Weinstock, G.M.; Roth, J.R.

    1996-01-01

    Tandem duplication of chromosomal segments has been recognized as a frequent mutational mechanism in several genetic model systems. In bacteria, fruit flies, and humans, duplications form by similar molecular mechanisms and appear to be important in genome evolution. 80 refs.

  8. The role of pulses in sustainable and healthy food systems.

    PubMed

    McDermott, John; Wyatt, Amanda J

    2017-03-01

    Improving nutrition is a development priority, particularly in low- and middle-income countries (LMICs) in Africa and South Asia, in which there is a persistent burden of undernutrition and increasing obesity. Healthy food systems can play a necessary role, aligned with other multisectoral actions, in addressing this challenge. Contributing to improved nutrition and health outcomes through food-based solutions is complex. In considering the role that pulses can play in addressing this challenge, there are useful conceptual frameworks and emerging lessons. National food systems in LMICs provide limited diet quality. Foods for a healthy diet may be produced locally, but they increasingly rely on improved markets and trade. What might be done to transform food systems for healthier diets, and what role can pulses play? Food systems innovations will require a convergence of technical innovation with smarter institutional arrangements and more effective policies and regulations. In many countries in Africa and South Asia, pulses can make important contributions to healthier diets. Options for supporting pulses to make a greater contribution to healthier diets include increasing the efficiency of pulse supply chains, creating more effective public-private institutional arrangements for innovation, and establishing policies, regulations, and investments that are nutrition sensitive.

  9. Duplication in DNA Sequences

    NASA Astrophysics Data System (ADS)

    Ito, Masami; Kari, Lila; Kincaid, Zachary; Seki, Shinnosuke

    The duplication and repeat-deletion operations are the basis of a formal language theoretic model of errors that can occur during DNA replication. During DNA replication, subsequences of a strand of DNA may be copied several times (resulting in duplications) or skipped (resulting in repeat-deletions). As formal language operations, iterated duplication and repeat-deletion of words and languages have been well studied in the literature. However, little is known about single-step duplications and repeat-deletions. In this paper, we investigate several properties of these operations, including closure properties of language families in the Chomsky hierarchy and equations involving these operations. We also make progress toward a characterization of regular languages that are generated by duplicating a regular language.

  10. DEMONSTRATION BULLETIN: CELLO PULSE COMBUSTION BURNER SYSTEM/SONOTECH INC.

    EPA Science Inventory

    Sonotech, Inc. (Sonotech), of Atlanta, GA, the developer of the Cello® pulse combustion burner, claims that its burner system can be beneficial to a variety of combustion processes. The system incorporates a combustor that can be tuned to induce large amplitude sonic pulsation...

  11. Pulsed Laser Shearography System for Defence Research and Education

    DTIC Science & Technology

    2017-09-15

    RESEARCH AND EDUCATION PRINCIPAL INVESTIGATOR: V. ARANCHUK SECURITY CLASSIFICATION: UNCLASSIFIED 2 Table of Contents LONG-TERM GOALS...Defense Research and Education LONG-TERM GOALS The University of Mississippi purchased a pulsed digital shearography system for research...and education involving vibration analysis under the Defense University Research Instrumentation Program (DURIP). This system will be used to

  12. DEMONSTRATION BULLETIN: CELLO PULSE COMBUSTION BURNER SYSTEM/SONOTECH INC.

    EPA Science Inventory

    Sonotech, Inc. (Sonotech), of Atlanta, GA, the developer of the Cello® pulse combustion burner, claims that its burner system can be beneficial to a variety of combustion processes. The system incorporates a combustor that can be tuned to induce large amplitude sonic pulsation...

  13. Tunable pulse width and multi-megawatt peak-power pulses from a nonlinearly compressed monolithic fiber MOPA system

    NASA Astrophysics Data System (ADS)

    Yamashita, Ryutarou; Maeda, Kazuo; Watanabe, Goro; Tei, Kazuyoku; Yamaguchi, Shigeru; Enokidani, Jun; Sumida, Shin

    2016-03-01

    We report on tunable pulse width and high peak power pulse generation from a nonlinearly compressed monolithic fiber MOPA system. The master seed source employs a Mach-Zehnder intensity modulator (MZIM). This seed source has operational flexibility with respect to pulse width, 90 ps to 2 ns and repetition rate, 200 kHz to 2 MHz. The seed pulses are amplified by a monolithic three-stage amplifier system based on polarization maintain Yb-doped fibers. The maximum output power was 32 W at the shortest pulse condition, the pulse width of 90 ps and the repetition rate of 750 kHz. A spectral width after amplification was broadened to 0.73 nm at RMS width. Both of ASE and SRS are not observed in the spectrum. After amplification, we also demonstrated pulse compression with a small piece of chirped volume Bragg-grating (CVBG) which has the dispersion rate of 81 ps/nm. As a result of pulse compression, the shortest pulse width was reduced from 90 ps to 3.5 ps, which brought an increase of the peak power up to 3.2 MW. The compressed pulses are clean with little structure in their wings. We can expand the operation range of the monolithic fiber MOPA system in pulse width, 3.5 ps to 2 ns.

  14. 48 CFR 1352.231-71 - Duplication of effort.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Duplication of effort. 1352.231-71 Section 1352.231-71 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE CLAUSES... Duplication of effort. As prescribed in 48 CFR 1331.205-70, insert the following clause: Duplication of...

  15. A 16 MJ compact pulsed power system for electromagnetic launch

    NASA Astrophysics Data System (ADS)

    Dai, Ling; Zhang, Qin; Zhong, Heqing; Lin, Fuchang; Li, Hua; Wang, Yan; Su, Cheng; Huang, Qinghua; Chen, Xu

    2015-07-01

    This paper has established a compact pulsed power system (PPS) of 16 MJ for electromagnetic rail gun. The PPS consists of pulsed forming network (PFN), chargers, monitoring system, and current junction. The PFN is composed of 156 pulse forming units (PFUs). Every PFU can be triggered simultaneously or sequentially in order to obtain different total current waveforms. The whole device except general control table is divided into two frameworks with size of 7.5 m × 2.2 m × 2.3 m. It is important to estimate the discharge current of PFU accurately for the design of the whole electromagnetic launch system. In this paper, the on-state characteristics of pulse thyristor have been researched to improve the estimation accuracy. The on-state characteristics of pulse thyristor are expressed as a logarithmic function based on experimental data. The circuit current waveform of the single PFU agrees with the simulating one. On the other hand, the coaxial discharge cable is a quick wear part in PFU because the discharge current will be up to dozens of kA even hundreds of kA. In this article, the electromagnetic field existing in the coaxial cable is calculated by finite element method. On basis of the calculation results, the structure of cable is optimized in order to improve the limit current value of the cable. At the end of the paper, the experiment current wave of the PPS with the load of rail gun is provided.

  16. A 16 MJ compact pulsed power system for electromagnetic launch.

    PubMed

    Dai, Ling; Zhang, Qin; Zhong, Heqing; Lin, Fuchang; Li, Hua; Wang, Yan; Su, Cheng; Huang, Qinghua; Chen, Xu

    2015-07-01

    This paper has established a compact pulsed power system (PPS) of 16 MJ for electromagnetic rail gun. The PPS consists of pulsed forming network (PFN), chargers, monitoring system, and current junction. The PFN is composed of 156 pulse forming units (PFUs). Every PFU can be triggered simultaneously or sequentially in order to obtain different total current waveforms. The whole device except general control table is divided into two frameworks with size of 7.5 m × 2.2 m × 2.3 m. It is important to estimate the discharge current of PFU accurately for the design of the whole electromagnetic launch system. In this paper, the on-state characteristics of pulse thyristor have been researched to improve the estimation accuracy. The on-state characteristics of pulse thyristor are expressed as a logarithmic function based on experimental data. The circuit current waveform of the single PFU agrees with the simulating one. On the other hand, the coaxial discharge cable is a quick wear part in PFU because the discharge current will be up to dozens of kA even hundreds of kA. In this article, the electromagnetic field existing in the coaxial cable is calculated by finite element method. On basis of the calculation results, the structure of cable is optimized in order to improve the limit current value of the cable. At the end of the paper, the experiment current wave of the PPS with the load of rail gun is provided.

  17. The Advanced Photon Source pulsed deflecting cavity RF system.

    SciTech Connect

    Cours, A.; DiMonte, N. P.; Smith, T. L.; Waldschmidt, G.

    2008-01-01

    The Advanced Photon Source Deflecting Cavity System for producing short X-ray pulses uses two multi-cell, S-band cavities to apply a deflecting voltage to the stored electron beam ahead of an undulator that supports a beamline utilizing picosecond X-rays. Two additional multi-cell cavities are then used to cancel out the perturbation and restore the electron beam to its nominal orbit. The pulsed rf system driving the deflecting cavities is described. Design tradeoffs are discussed with emphasis on topology considerations and digital control loops making use of sampling technology in a manner consistent with the present state of the art.

  18. System for rapidly tuning a low pressure pulsed laser

    SciTech Connect

    Fox, J.A.; Ahl, J.L.

    1989-09-19

    This patent describes a system for rapidly tuning a low pressure pulsed laser over multiple wavelengths. The system comprising: a low pressure one electrode pair discharge region in a laser cavity having a laser trigger means connected to the electrode pair for initiating low pressure discharge within the discharge region; a quarterwave plate and a Q-switch in optical alignment with the one electrode pair discharge region along the laser optical axis; a fixed laser output coupler at the discharge region end of the laser cavity; and a rotatable grating means for wavelength switching the at least two high gain Q-switched pulses.

  19. Numerical analysis of single pulse and differential pulse-width pair BOTDA systems in the high spatial resolution regime.

    PubMed

    Minardo, Aldo; Bernini, Romeo; Zeni, Luigi

    2011-09-26

    A numerical analysis of conventional and differential pulse-width pair Brillouin optical time domain analysis systems is reported. The tests are focused on determining the performance of these systems especially in terms of spatial resolution, as a function of the pulse characteristics. A new definition of spatial resolution is given, based on analysis of the shape of the Brillouin gain spectrum. The influence of the rise/fall time of the pulse light to the spatial resolution is also studied.

  20. Magnetically insulated electron flows in pulsed power systems

    NASA Astrophysics Data System (ADS)

    Lawconnell, Robert I.

    1989-08-01

    Magnetic insulation is crucial in the operation of large pulsed power systems. Particular attention will be paid to describing magnetic insulation in realistic pulsed power systems. A theoretical model is developed that allows the production of self consistent magnetically insulated laminar flows in perturbed cylindrical systems given only the electron density profile. The theory is checked and justified by detailed comparisons with results from a 2-dimensional electromagnetic code, MASK. The procedure followed in the theoretical development is to use the relativistic Vlasov equation, Ampere's law and Gauss' law, to obtain a relation between the density profile and the velocity profile for insulated flows. Given the density profile and the corresponding derived velocity profile, a self consistent flow solution is obtained by means of Maxwell's equations. It is checked by taking a special case (corresponding to no perturbations) which results in the well known Brillouin flow theory. Emphasis is placed on determining the magnetic insulation threshold of a pulsed power system employing a plasma erosion opening switch. The procedure employed in the computational study is to vary critical aspects of the pulsed power system and then note whether magnetic insulation breaks down. The point at which magnetic insulation breaks down (as a function of geometry, load impedance, and applied voltage) is the magnetic insulation threshold for the system.

  1. Optimized control of multistate quantum systems by composite pulse sequences

    SciTech Connect

    Genov, G. T.; Vitanov, N. V.; Torosov, B. T.

    2011-12-15

    We introduce a technique for derivation of high-fidelity composite pulse sequences for two types of multistate quantum systems: systems with the SU(2) and Morris-Shore dynamic symmetries. For the former type, we use the Majorana decomposition to reduce the dynamics to an effective two-state system, which allows us to find the propagator analytically and use the pool of available composite pulses for two-state systems. For the latter type of multistate systems, we use the Morris-Shore decomposition, which reduces the multistate dynamics to a set of two-state systems. We present examples which demonstrate that the multistate composite sequences open a variety of possibilities for coherent control of quantum systems with multiple states.

  2. Optimized pulse sequences for suppressing unwanted transitions in quantum systems

    NASA Astrophysics Data System (ADS)

    Schroeder, C. A.; Agarwal, G. S.

    2011-01-01

    We investigate the nature of the pulse sequence so that unwanted transitions in quantum systems can be inhibited optimally. For this purpose we show that the sequence of pulses proposed by Uhrig [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.98.100504 98, 100504 (2007)] in the context of inhibition of environmental dephasing effects is optimal. We derive exact results for inhibiting the transitions and confirm the results numerically. We posit a very significant improvement by usage of the Uhrig sequence over an equidistant sequence in decoupling a quantum system from unwanted transitions. The physics of inhibition is the destructive interference between transition amplitudes before and after each pulse.

  3. Combined pulse-oximeter-NIRS system for biotissue diagnostics

    NASA Astrophysics Data System (ADS)

    Hovhannisyan, Vladimir A.

    2005-08-01

    Multi-wavelength (670, 805, 848 and 905 nm), multi-detector device for non-invasive measurement of biochemical components concentration in human or animal tissues, combining the methods of conventional pulse-oximetry and near infrared spectroscopy, is developed. The portable and clinically applicable system allows to measure heart pulse rate, oxygen saturation of arterial hemoglobin (pulse-oximetry method) and local absolute concentration of oxyhemoglobin, deoxyhemoglobin and oxidized cytochrome aa3 or other IR absorbed compounds (NIRS method). The system can be applied in monitoring of oxygen availability and utilization by the brain in neonatal and adults, neuro- traumatology, intensive care medicine, transplantation and plastic surgery, in sport, high-altitude and aviation medicine.

  4. Pulsed power systems for environmental and industrial applications

    NASA Astrophysics Data System (ADS)

    Neau, E. L.

    1994-10-01

    The development of high peak power simulators, laser drivers, free electron lasers, and Inertial Confinement Fusion drivers is being extended to high average power short-pulse machines with the capabilities of performing new roles in environmental cleanup and industrial manufacturing processes. We discuss a new class of short-pulse, high average power accelerator that achieves megavolt electron and ion beams with 10's of kiloamperes of current and average power levels in excess of 100 kW. Large treatment areas are possible with these systems because kilojoules of energy are available in each output pulse. These systems can use large area x-ray converters for applications requiring grater depth of penetration such as food pasteurization and waste treatment. The combined development of this class of accelerators and applications, and Sandia National Laboratories, is called Quantum Manufacturing.

  5. Pulsed power systems for environmental and industrial applications

    SciTech Connect

    Neau, E.L.

    1993-12-31

    The development of high peak power simulators, laser drivers, free electron lasers, and Inertial Confinement Fusion drivers is being extended to high average power short-pulse machines with the capabilities of performing new roles in environmental cleanup and industrial manufacturing processes. We discuss a new class of short-pulse, high average power accelerator that achieves megavolt electron and ion beams with 10`s of kiloamperes of current and average power levels in excess of 100 KW. Large treatment areas are possible with these systems because kilojoules of energy are available in each output pulse. These systems can use large area x-ray converters for applications requiring greater depth of penetration such as food pasteurization and waste treatment. The combined development of this class of accelerators and applications, at Sandia National Laboratories, is called Quantum Manufacturing.

  6. Duplicate Federal Payments for Dual Enrollees in Medicare Advantage Plans and the Veterans Affairs Health Care System

    PubMed Central

    Trivedi, Amal N.; Grebla, Regina C.; Jiang, Lan; Yoon, Jean; Mor, Vincent; Kizer, Kenneth W.

    2013-01-01

    Context Some veterans are eligible to enroll simultaneously in a Medicare Advantage (MA) plan and the Veterans Affairs health care system (VA). This scenario produces the potential for redundant federal spending because MA plans would receive payments to insure veterans who receive care from the VA, another taxpayer-funded health plan. Objective To quantify the prevalence of dual enrollment in VA and MA, the concurrent use of health services in each setting, and the estimated costs of VA care provided to MA enrollees. Design Retrospective analysis of 1 245 657 veterans simultaneously enrolled in the VA and an MA plan between 2004–2009. Main Outcome Measures Use of health services and inflation-adjusted estimated VA health care costs. Results Among individuals who were eligible to enroll in the VA and in an MA plan, the number of persons dually enrolled increased from 485 651 in 2004 to 924 792 in 2009. In 2009, 8.3% of the MA population was enrolled in the VA and 5.0% of MA beneficiaries were VA users. The estimated VA health care costs for MA enrollees totaled $13.0 billion over 6 years, increasing from $1.3 billion in 2004 to $3.2 billion in 2009. Among dual enrollees, 10% exclusively used the VA for outpatient and acute inpatient services, 35% exclusively used the MA plan, 50% used both the VA and MA, and 4% received no services during the calendar year. The VA financed 44% of all outpatient visits (n=21 353 841), 15% of all acute medical and surgical admissions (n=177 663), and 18% of all acute medical and surgical inpatient days (n=1 106 284) for this dually enrolled population. In 2009, the VA billed private insurers $52.3 million to reimburse care provided to MA enrollees and collected $9.4 million (18% of the billed amount; 0.3% of the total cost of care). Conclusions The federal government spends a substantial and increasing amount of potentially duplicative funds in 2 separate managed care programs for the care of same individuals. PMID:22735360

  7. Flight validation of a pulsed smoke flow visualization system

    NASA Technical Reports Server (NTRS)

    Ward, Donald T.; Dorsett, Kenneth M.

    1993-01-01

    A flow visualization scheme, designed to measure vortex fluid dynamics on research aircraft, was validated in flight. Strake vortex trajectories and axial core velocities were determined using pulsed smoke, high-speed video images, and semiautomated image edge detection hardware and software. Smoke was pulsed by using a fast-acting three-way valve. After being redesigned because of repeatedly jamming in flight, the valve shuttle operated flawlessly during the last two tests. A 25-percent scale, Gothic strake was used to generate vortex over the wing of a GA-7 Cougar and was operated at a local angle of attack of 22 degrees and Reynolds number of approximately 7.8 x 10(exp 5)/ft. Maximum axial velocities measured in the vortex core were between 1.75 and 1.95 times the freestream velocity. Analysis of the pulsed smoke system's affect on forebody vortices indicates that the system may reorient the forebody vortex system; however, blowing momentum coefficients normally used will have no appreciable affect on the leading-edge extension vortex system. It is recommended that a similar pulsed smoke system be installed on the F/A-18 High Angle Research Vehicle and that this approach be used to analyze vortex core dynamics during the remainder of its high-angle-of-attack research flights.

  8. MHD-Stabilization of Axisymmetric Mirror Systems Using Pulsed ECRH

    SciTech Connect

    Post, R F

    2009-11-20

    This paper, part of a continuing study of means for the stabilization of MHD interchange modes in axisymmertric mirror-based plasma confinement systems, is aimed at a preliminary look at a technique that would employ a train of plasma pressure pulses produced by ECRH to accomplish the stabilization. The purpose of using sequentially pulsed ECRH rather than continuous-wave ECRH is to facilitate the localization of the heated-electron plasma pulses in regions of the magnetic field with a strong positive field-line curvature, e. g. in the 'expander' region of the mirror magnetic field, outside the outermost mirror, or in other regions of the field with positive field-line curvature. The technique proposed, of the class known as 'dynamic stabilization,' relies on the time-averaged effect of plasma pressure pulses generated in regions of positive field-line curvature to overcome the destabilizing effect of plasma pressure in regions of negative field-line curvature within the confinement region. As will also be discussed in the paper, the plasma pulses, when produced in regions of the confining having a negative gradient, create transient electric potentials of ambipolar origin, an effect that was studied in 1964 in The PLEIDE experiment in France. These electric fields preserve the localization of the hot-electron plasma pulses for a time determined by ion inertia. It is suggested that it may be possible to use this result of pulsed ECRH not only to help to stabilize the plasma but also to help plug mirror losses in a manner similar to that employed in the Tandem Mirror.

  9. Beamlet pulse-generation and wavefront-control system

    SciTech Connect

    Van Wonterghem, B.M.; Salmon, J.T.; Wilcox, R.W.

    1996-06-01

    The Beamlet pulse-generation system (or {open_quotes}front end{close_quotes}) refers to the laser hardware that generates the spatially and temporally shaped pulse that is injected into the main laser cavity. All large ICF lasers have pulse-generation systems that typically consist of a narrow-band oscillator, elector-optic modulators for temporal and bandwidth shaping, and one or more preamplifiers. Temporal shaping is used to provide the desired laser output pulse shape and also to compensate for gain saturation effects in the large-aperture amplifiers. Bandwidth is applied to fulfill specific target irradiation requirements and to avoid stimulated Brillouin scattering (SBS) in large-aperture laser components. Usually the sharp edge of the beam`s spatial intensity profile is apodized before injection in the main amplifier beam line. This prevents large-amplitude ripples on the intensity profile. Here the authors briefly review the front-end design and discuss improvements to the oscillator and modulator systems. Their main focus, however, is to describe Beamlet`s novel beam-shaping and wavefront-control systems that have recently been fully activated and tested.

  10. Remote Pulsed-Laser Raman Spectroscopy System for Mineral Analysis

    NASA Technical Reports Server (NTRS)

    Sharma, S. K.; Angel, S. M.; Ghosh, M.; Hubble, H. W.; Lucey, P. G.

    2001-01-01

    We have measured Raman spectra of carbonate, silicate, and hydrous silicate and sulfate minerals, our new remote-pulsed Raman system, indicating that it can be used to analyze the minerals on planetary surfaces to a distance of 10 to 66 meters. Additional information is contained in the original extended abstract.

  11. Nuclear electromagnetic pulse and the electric power system

    SciTech Connect

    Legro, J.R.; Reed, T.J.

    1985-01-01

    A single, high-altitude nuclear detonation over the continental United States can expose large geographic areas to transient, electromagnetic pulse (EMP). The initial electromagnetic fields produced by this event have been defined as high-altitude electromagnetic pulse (HEMP). Later-time, low frequency fields have been defined as magnetohydrodynamic-electromagnetic pulse (MHD-EMP). Nuclear detonations at, or near the surface of the earth can also produce transient EMP. These electromagnetic phenomena have been defined as source region electromagnetic pulse (SREMP). The Division of Electric Energy Systems (EES) of the United States Department of Energy (DOE) has formulated and implemented a Program Plan to assess the possible effects of the above nuclear EMP on civilian electric power systems. This unclassified research effort is under the technical leadership of the Oak Ridge National Laboratory. This paper presents a brief perspective of EMP phenomenology and important interaction issues for power systems based on research performed by Westinghouse Advanced Systems Technology as a principal subcontractor in the research effort.

  12. Remote Pulsed-Laser Raman Spectroscopy System for Mineral Analysis

    NASA Technical Reports Server (NTRS)

    Sharma, S. K.; Angel, S. M.; Ghosh, M.; Hubble, H. W.; Lucey, P. G.

    2001-01-01

    We have measured Raman spectra of carbonate, silicate, and hydrous silicate and sulfate minerals, our new remote-pulsed Raman system, indicating that it can be used to analyze the minerals on planetary surfaces to a distance of 10 to 66 meters. Additional information is contained in the original extended abstract.

  13. EML pulse ionization chamber systems for /sup 222/Rn measurements

    SciTech Connect

    Fisenne, I M; Keller, H W

    1985-03-01

    Radon measurements have been performed with pulse ionization chambers at the Environmental Measurements Laboratory (EML) for over 35 years. This report describes the evolution of radon measurement systems, with emphasis on the continuous quality control efforts at EML. 38 refs., 3 figs., 3 tabs.

  14. 47 CFR 76.1508 - Network non-duplication.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Network non-duplication. 76.1508 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Open Video Systems § 76.1508 Network non-duplication. (a... regarding the exercise of network non-duplication rights immediately available to all appropriate video...

  15. 47 CFR 76.1508 - Network non-duplication.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Network non-duplication. 76.1508 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Open Video Systems § 76.1508 Network non-duplication. (a... regarding the exercise of network non-duplication rights immediately available to all appropriate video...

  16. 47 CFR 76.1508 - Network non-duplication.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Network non-duplication. 76.1508 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Open Video Systems § 76.1508 Network non-duplication. (a... regarding the exercise of network non-duplication rights immediately available to all appropriate video...

  17. 47 CFR 76.1508 - Network non-duplication.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Network non-duplication. 76.1508 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Open Video Systems § 76.1508 Network non-duplication. (a... regarding the exercise of network non-duplication rights immediately available to all appropriate video...

  18. 47 CFR 76.1508 - Network non-duplication.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Network non-duplication. 76.1508 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Open Video Systems § 76.1508 Network non-duplication. (a... regarding the exercise of network non-duplication rights immediately available to all appropriate video...

  19. Review of the Procyon explosive pulsed power system

    NASA Astrophysics Data System (ADS)

    Goforth, J. H.; Oona, H.; Greene, A. E.

    1993-06-01

    #he Procyon explosive pulsed power system is designed for powering plasma z-pinch experiments. It begins with a helical explosive-driven magnetic flux compression generator (MCG) for amplifying seed current from a capacitor bank into a storage inductor. One conductor element of the storage inductor is an explosively formed fuse (EFF) opening switch tailored to divert current to a plasma flow switch (PFS) in less than 3 microseconds. The PFS, in turn, delivers current to a z-pinch load. Experiments to date have concentrated on the explosive pulsed power components and PFS. This paper focuses on the results of a recent full energy MCG/EFF/PFS test.

  20. A design approach for systems based on magnetic pulse compression.

    PubMed

    Kumar, D Durga Praveen; Mitra, S; Senthil, K; Sharma, D K; Rajan, Rehim N; Sharma, Archana; Nagesh, K V; Chakravarthy, D P

    2008-04-01

    A design approach giving the optimum number of stages in a magnetic pulse compression circuit and gain per stage is given. The limitation on the maximum gain per stage is discussed. The total system volume minimization is done by considering the energy storage capacitor volume and magnetic core volume at each stage. At the end of this paper, the design of a magnetic pulse compression based linear induction accelerator of 200 kV, 5 kA, and 100 ns with a repetition rate of 100 Hz is discussed with its experimental results.

  1. A very wide frequency band pulsed/IF radar system

    NASA Technical Reports Server (NTRS)

    Jones, D. N.; Burnside, W. D.

    1988-01-01

    A pulsed/IF radar for compact range radar cross section measurements has been developed which converts RF returns to a fixed IF, so that amplification and grating may be performed at one frequency. This permits the use of components which have optimal performance at this frequency which results in a corresponding improvement in performance. Sensitivity and dynamic range are calculated for this system and compared with our old radar, and the effect of pulse width on clutter level is also studied. Sensitivity and accuracy tests are included to verify the performance of the radar.

  2. Progress in developing repetitive pulse systems utilizing inductive energy storage

    SciTech Connect

    Honig, E.M.

    1983-01-01

    High-power, fast-recovery vacuum switches were used in a new repetitive counterpulse and transfer circuit to deliver a 5-kHz pulse train with a peak power of 75 MW (at 8.6 kA) to a 1-..cap omega.. load, resulting in the first demonstration of fully controlled, high-power, high-repetition-rate operation of an inductive energy-storage and transfer system with nondestructive switches. New circuits, analytical and experimental results, and feasibility of 100-kV repetitive pulse generation are discussed. A new switching concept for railgun loads is presented.

  3. An integrated CMOS detection system for optical short-pulse

    NASA Astrophysics Data System (ADS)

    Kim, Chang-Gun; Hong, Nam-Pyo; Choi, Young-Wan

    2014-03-01

    We present design of a front-end readout system consisting of charge sensitive amplifier (CSA) and pulse shaper for detection of stochastic and ultra-small semiconductor scintillator signal. The semiconductor scintillator is double sided silicon detector (DSSD) or avalanche photo detector (APD) for high resolution and peak signal reliability of γ-ray or X-ray spectroscopy. Such system commonly uses low noise multichannel CSA. Each CSA in multichannel includes continuous reset system based on tens of MΩ and charge-integrating capacitor in feedback loop. The high value feedback resistor requires large area and huge power consumption for integrated circuits. In this paper, we analyze these problems and propose a CMOS short pulse detection system with a novel CSA. The novel CSA is composed of continuous reset system with combination of diode connected PMOS and 100 fF. This structure has linearity with increased input charge quantity from tens of femto-coulomb to pico-coulomb. Also, the front-end readout system includes both slow and fast shapers for detecting CSA output and preventing pile-up distortion. Shaping times of fast and slow shapers are 150 ns and 1.4 μs, respectively. Simulation results of the CMOS detection system for optical short-pulse implemented in 0.18 μm CMOS technology are presented.

  4. Two Serial Data to Pulse Code Modulation System Interfaces

    NASA Technical Reports Server (NTRS)

    Hamory, Phil

    2006-01-01

    Two pulse code modulation (PCM) system interfaces for asynchronous serial data are described. One interface is for global positioning system (GPS) data on the NASA Dryden Flight Research Center (DFRC) F-15B (McDonnell Douglas Corporation, St. Louis, Missouri) airplane, tail number 836 (F-15B/836). The other is for flight control computer data on the duPont Aerospace (La Jolla, California) DP-1, a 53-percent scale model of the duPont Aerospace DP-2.

  5. Pulse laser high speed schlieren photographic system and its application

    NASA Astrophysics Data System (ADS)

    Lin, Yuju; Li, Shicheng; Wang, Qingyou; Ni, Wenjun; Xiang, Yong

    1989-06-01

    Two models of a pulsed Q-switched ruby laser high speed schlieren photographic system are introduced. The models are described and results are presented from tests using each model. One model is used to record the armor-piercing process of the terminal trajectory and the chamber shooting process of the midway trajectory. The other model is used to study the detonating mechanism of high energy dynamite. Also, possibilities for future development of the system are considered.

  6. Thermal management in high average power pulsed compression systems

    SciTech Connect

    Wavrik, R.W.; Reed, K.W.; Harjes, H.C.; Weber, G.J.; Butler, M.; Penn, K.J.; Neau, E.L.

    1992-08-01

    High average power repetitively pulsed compression systems offer a potential source of electron beams which may be applied to sterilization of wastes, treatment of food products, and other environmental and consumer applications. At Sandia National Laboratory, the Repetitive High Energy Pulsed Power (RHEPP) program is developing a 7 stage magnetic pulse compressor driving a linear induction voltage adder with an electron beam diode load. The RHEPP machine is being design to deliver 350 kW of average power to the diode in 60 ns FWHM, 2.5 MV, 3 kJ pulses at a repetition rate of 120 Hz. In addition to the electrical design considerations, the repetition rate requires thermal management of the electrical losses. Steady state temperatures must be kept below the material degradation temperatures to maximize reliability and component life. The optimum design is a trade off between thermal management, maximizing overall electrical performance of the system, reliability, and cost effectiveness. Cooling requirements and configurations were developed for each of the subsystems of RHEPP. Finite element models that combine fluid flow and heat transfer were used to screen design concepts. The analysis includes one, two, and three dimensional heat transfer using surface heat transfer coefficients and boundary layer models. Experiments were conducted to verify the models as well as to evaluate cooling channel fabrication materials and techniques in Metglas wound cores. 10 refs.

  7. Instrumentation of dynamic gas pulse loading system

    SciTech Connect

    Mohaupt, H.

    1992-04-14

    The overall goal of this work is to further develop and field test a system of stimulating oil and gas wells, which increases the effective radius of the well bore so that more oil can flow into it, by recording pressure during the gas generation phase in real time so that fractures can be induced more predictably in the producing formation. Task 1: Complete the laboratory studies currently underway with the prototype model of the instrumentation currently being studied. Task 2: Perform field tests of the model in the Taft/Bakersfield area, utilizing operations closest to the engineers working on the project, and optimize the unit for various conditions encountered there. Task 3: Perform field test of the model in DGPL jobs which are scheduled in the mid-continent area, and optimize the unit for downhole conditions encountered there. Task 4: Analyze and summarize the results achieved during the complete test series, documenting the steps for usage of downhole instrumentation in the field, and compile data specifying use of the technology by others. Task 5: Prepare final report for DOE, and include also a report on the field tests completed. Describe and estimate the probability of the technology being commercialized and in what time span. The project has made substantial technical progress, though we are running about a month behind schedule. Expenditures are in line with the schedule. Increased widespread interest in the use of DGPL stimulation has kept us very busy. The computer modeling and test instrumentation developed under this program is already being applied to commercial operations.

  8. Water depth measurement using an airborne pulsed neon laser system

    NASA Technical Reports Server (NTRS)

    Hoge, F. E.; Swift, R. N.; Frederick, E. B.

    1980-01-01

    The paper presents the water depth measurement using an airborne pulsed neon laser system. The results of initial base-line field test results of NASA airborne oceanographic lidar in the bathymetry mode are given, with water-truth measurements of depth and beam attenuation coefficients by boat taken at the same time as overflights to aid in determining the system's operational performance. The nadir-angle tests and field-of-view data are presented; this laser bathymetry system is an improvement over prior models in that (1) the surface-to-bottom pulse waveform is digitally recorded on magnetic tape, and (2) wide-swath mapping data may be routinely acquired using a 30 deg full-angle conical scanner.

  9. Pulse-noise approach for classical spin systems.

    PubMed

    Garanin, D A

    2017-01-01

    For systems of classical spins interacting with the bath via damping and thermal noise, an approach is suggested to replace the white noise by a pulse noise acting at regular time intervals Δt, within which the system evolves conservatively. The method is working well in the typical case of a small dimensionless damping constant λ and allows a considerable speedup of computations by using high-order numerical integrators with a large time step δt (up to a fraction of the precession period), while keeping δt≪Δt to reduce the relative contribution of noise-related operations. In cases when precession can be discarded, δt can be increased up to a fraction of the relaxation time ∝1/λ that leads to a further speedup. This makes equilibration speed comparable with that of the Metropolis Monte Carlo method. The pulse-noise approach is tested on single-spin and multispin models.

  10. Pulse-noise approach for classical spin systems

    NASA Astrophysics Data System (ADS)

    Garanin, D. A.

    2017-01-01

    For systems of classical spins interacting with the bath via damping and thermal noise, an approach is suggested to replace the white noise by a pulse noise acting at regular time intervals Δ t , within which the system evolves conservatively. The method is working well in the typical case of a small dimensionless damping constant λ and allows a considerable speedup of computations by using high-order numerical integrators with a large time step δ t (up to a fraction of the precession period), while keeping δ t ≪Δ t to reduce the relative contribution of noise-related operations. In cases when precession can be discarded, δ t can be increased up to a fraction of the relaxation time ∝1 /λ that leads to a further speedup. This makes equilibration speed comparable with that of the Metropolis Monte Carlo method. The pulse-noise approach is tested on single-spin and multispin models.

  11. High Pulsed Power, Self Excited Magnetohydrodynamic Power Generation Systems

    DTIC Science & Technology

    1985-12-27

    Degree of Ionization of Cesium on Performance 72 3.5.7. Effect of Channel Area Ratio on Performance 73 3.5.8. Comparison of Helium vs Argon Generator...EXPLOSIVE PULSED SYSTEM WEIGHTS,REF.2 32 TABLE 5: POWER DENSITY & ENTHALPY EXTRACTION OF CLOSED CYCLE GENERATORS 35 TABLE 6: ENTHALPY EXTRACTION VS PRESSURE...OF ALUMINUM PARTICLES 50 TABLE 11. ALUMINUM PARTICLE BURNING TIMES vs OPERATING CONDITIONS 52 TABLE 12. TOTAL COMBUSTION TIME OF Al. PARTICLES vs

  12. Ultrashort Laser Pulse Induced Electromagnetic Stress on Biological Macromolecular Systems.

    DTIC Science & Technology

    1979-11-01

    ULTRASHORT LASER PULSE INDUCED ~~~~~ ELECTROMAGNET IC STRESS ON BIOLOGICAL MACROMOLECULAR SYSTEMS Adam P. Bruckner , Ph.D. ( i~iiCJ. Michael ...AFSC, Brooks Air Force Base, Texas. Dr. John Taboada (RZL) was the Laboratory Project Scientjst..in...Charge When U.S. Goverrijie~t drawings...available to the general public , including foreignnations. Thi s technical report has been reviewed and is approved for publ i-cation. OHN TABOADA , Ph.D

  13. PHASE NOISE COMPARISON OF SHORT PULSE LASER SYSTEMS

    SciTech Connect

    Shukui Zhang; Stephen Benson; John Hansknecht; David Hardy; George Neil; Michelle D. Shinn

    2006-08-27

    This paper describes phase noise measurements of several different laser systems that have completely different gain media and configurations including a multi-kW free-electron laser. We will focus on state-of-the-art short pulse lasers, especially drive lasers for photocathode injectors. Phase noise comparison of the FEL drive laser, electron beam and FEL laser output also will be presented.

  14. Numerical control system of battery welding with pulsed YAG laser

    NASA Astrophysics Data System (ADS)

    Zhang, Guoshun; Yang, Zhaoxia; Zhang, Taishi; Wei, Zhigang; Li, Chaoyang

    1999-09-01

    This article briefly introduces the pulse YAG laser welding system, a new research achievement of my section. This system can weld the electric pole, the holly board and other aluminum parts of lithium battery, and the process of loading, unloading, compressing and welding can be completed automatically. Moreover, the software proprietary of the system is very good, and its interface is friendly too. In order to achieve optimum welding effect, we have designed special laser discharging waveform. Its rise delay time, fall delay time, and width are all designed specially. With this special technology, the welding spot we get is smooth like mirror, and the welding intensity can be controlled conveniently.

  15. Active high-power RF switch and pulse compression system

    DOEpatents

    Tantawi, Sami G.; Ruth, Ronald D.; Zolotorev, Max

    1998-01-01

    A high-power RF switching device employs a semiconductor wafer positioned in the third port of a three-port RF device. A controllable source of directed energy, such as a suitable laser or electron beam, is aimed at the semiconductor material. When the source is turned on, the energy incident on the wafer induces an electron-hole plasma layer on the wafer, changing the wafer's dielectric constant, turning the third port into a termination for incident RF signals, and. causing all incident RF signals to be reflected from the surface of the wafer. The propagation constant of RF signals through port 3, therefore, can be changed by controlling the beam. By making the RF coupling to the third port as small as necessary, one can reduce the peak electric field on the unexcited silicon surface for any level of input power from port 1, thereby reducing risk of damaging the wafer by RF with high peak power. The switch is useful to the construction of an improved pulse compression system to boost the peak power of microwave tubes driving linear accelerators. In this application, the high-power RF switch is placed at the coupling iris between the charging waveguide and the resonant storage line of a pulse compression system. This optically controlled high power RF pulse compression system can handle hundreds of Megawatts of power at X-band.

  16. Interstitial duplication 19p

    SciTech Connect

    Stratton, R.F.; DuPont, B.R.; Moore, C.M.

    1995-07-17

    We report on a 9-month-old girl with an interstitial duplication of 19p, developmental delay, and multiple anomalies including bifrontal prominence, obtuse frontonasal angle, short columella, additional midline philtral pillar, midline ridge on the tongue, vertical midline ridge at the mental symphysis, and a complex congenital heart defect including severe branch pulmonary artery stenosis, secundum atrial septal defect (ASD), and several ventricular septal defects (VSDs). Use of fluorescent in situ hybridization (FISH) with chromosome 19- specific probes showed a direct duplication of bands 19p13.13 and 19p13.2. 6 refs., 1 fig.

  17. Brain evolution by brain pathway duplication

    PubMed Central

    Chakraborty, Mukta; Jarvis, Erich D.

    2015-01-01

    Understanding the mechanisms of evolution of brain pathways for complex behaviours is still in its infancy. Making further advances requires a deeper understanding of brain homologies, novelties and analogies. It also requires an understanding of how adaptive genetic modifications lead to restructuring of the brain. Recent advances in genomic and molecular biology techniques applied to brain research have provided exciting insights into how complex behaviours are shaped by selection of novel brain pathways and functions of the nervous system. Here, we review and further develop some insights to a new hypothesis on one mechanism that may contribute to nervous system evolution, in particular by brain pathway duplication. Like gene duplication, we propose that whole brain pathways can duplicate and the duplicated pathway diverge to take on new functions. We suggest that one mechanism of brain pathway duplication could be through gene duplication, although other mechanisms are possible. We focus on brain pathways for vocal learning and spoken language in song-learning birds and humans as example systems. This view presents a new framework for future research in our understanding of brain evolution and novel behavioural traits. PMID:26554045

  18. Brain evolution by brain pathway duplication.

    PubMed

    Chakraborty, Mukta; Jarvis, Erich D

    2015-12-19

    Understanding the mechanisms of evolution of brain pathways for complex behaviours is still in its infancy. Making further advances requires a deeper understanding of brain homologies, novelties and analogies. It also requires an understanding of how adaptive genetic modifications lead to restructuring of the brain. Recent advances in genomic and molecular biology techniques applied to brain research have provided exciting insights into how complex behaviours are shaped by selection of novel brain pathways and functions of the nervous system. Here, we review and further develop some insights to a new hypothesis on one mechanism that may contribute to nervous system evolution, in particular by brain pathway duplication. Like gene duplication, we propose that whole brain pathways can duplicate and the duplicated pathway diverge to take on new functions. We suggest that one mechanism of brain pathway duplication could be through gene duplication, although other mechanisms are possible. We focus on brain pathways for vocal learning and spoken language in song-learning birds and humans as example systems. This view presents a new framework for future research in our understanding of brain evolution and novel behavioural traits. © 2015 The Authors.

  19. An explosively driven high-power microwave pulsed power system

    NASA Astrophysics Data System (ADS)

    Elsayed, M. A.; Neuber, A. A.; Dickens, J. C.; Walter, J. W.; Kristiansen, M.; Altgilbers, L. L.

    2012-02-01

    The increased popularity of high power microwave systems and the various sources to drive them is the motivation behind the work to be presented. A stand-alone, self-contained explosively driven high power microwave pulsed power system has been designed, built, and tested at Texas Tech University's Center for Pulsed Power and Power Electronics. The system integrates four different sub-units that are composed of a battery driven prime power source utilizing capacitive energy storage, a dual stage helical flux compression generator as the main energy amplification device, an integrated power conditioning system with inductive energy storage including a fast opening electro-explosive switch, and a triode reflex geometry virtual cathode oscillator as the microwave radiating source. This system has displayed a measured electrical source power level of over 5 GW and peak radiated microwaves of about 200 MW. It is contained within a 15 cm diameter housing and measures 2 m in length, giving a housing volume of slightly less than 39 l. The system and its sub-components have been extensively studied, both as integrated and individual units, to further expand on components behavior and operation physics. This report will serve as a detailed design overview of each of the four subcomponents and provide detailed analysis of the overall system performance and benchmarks.

  20. Correction of Arbitrary Field Errors in Population Inversion of Quantum Systems by Universal Composite Pulses

    NASA Astrophysics Data System (ADS)

    Genov, Genko T.; Schraft, Daniel; Halfmann, Thomas; Vitanov, Nikolay V.

    2014-07-01

    We introduce universal broadband composite pulse sequences for robust high-fidelity population inversion in two-state quantum systems, which compensate deviations in any parameter of the driving field (e.g., pulse amplitude, pulse duration, detuning from resonance, Stark shifts, unwanted frequency chirp, etc.) and are applicable with any pulse shape. We demonstrate the efficiency and universality of these composite pulses by experimental data on rephasing of atomic coherences in a Pr3+:Y2SiO5 crystal.

  1. Spontaneous pulsing states in an active particle system

    NASA Astrophysics Data System (ADS)

    Klein, Sarah; Appert-Rolland, Cécile; Evans, Martin R.

    2016-09-01

    We study a two-lane two-species exclusion process inspired by Lin et al (2011 J. Stat. Mech. P09027) that exhibits a non-equilibrium pulsing phase. Particles move on two parallel one-dimensional tracks, with one open and one reflecting boundary. The particle type defines the hopping direction. When only particles hopping towards the open end are allowed to change lane, the system exhibits a phase transition from a low density phase to a pulsing phase depending on the ratio between particle injection and type-changing rate. This phase transition can be observed in the stochastic model as well as in a mean-field description. In the low density phase, the density profile can be predicted analytically. The pulsing phase is characterised by a fast filling of the system and—once filled—by a slowly backwards moving front separating a decreasing dense region and an expanding low density region. The hopping of the front on the discrete lattice is found to create density oscillations, both, in time and space. By means of a stability analysis we can predict the structure of the dense region during the emptying process, characterised by exponentially damped perturbations, both at the open end and near the moving front.

  2. Plasma Discharge Process in a Pulsed Diaphragm Discharge System

    NASA Astrophysics Data System (ADS)

    Duan, Jianjin; Hu, Jue; Zhang, Chao; Wen, Yuanbin; Meng, Yuedong; Zhang, Chengxu

    2014-12-01

    As one of the most important steps in wastewater treatment, limited study on plasma discharge process is a key challenge in the development of plasma applications. In this study, we focus on the plasma discharge process of a pulsed diaphragm discharge system. According to the analysis, the pulsed diaphragm discharge proceeds in seven stages: (1) Joule heating and heat exchange stage; (2) nucleated site formation; (3) plasma generation (initiation of the breakdown stage); (4) avalanche growth and plasma expansion; (5) plasma contraction; (6) termination of the plasma discharge; and (7) heat exchange stage. From this analysis, a critical voltage criterion for breakdown is obtained. We anticipate this finding will provide guidance for a better application of plasma discharges, especially diaphragm plasma discharges.

  3. Damped Rabi oscillations produced by adiabatic pulses in atomic systems

    NASA Astrophysics Data System (ADS)

    Brandão, P. A.

    2017-08-01

    Propagation of optical pulses in adiabatic conditions in two-level systems was reported to induce Rabi oscillations if the initial state has atomic coherence. This is a surprising result since in ordinary conditions the population dynamics follows the temporal field profile. In this paper we construct a simple two-level atom model and examine the role of Rabi oscillations in the presence of a damping γ term (decoherence). We have found that, depending on the time scale between 1 / γ and the pulse, Rabi oscillations are still present. However, if the atom decays faster than when the interaction takes place, Rabi oscillations are suppressed. Analytical solutions are also provided for this general case.

  4. Nonresonant interaction of ultrashort electromagnetic pulses with multilevel quantum systems

    NASA Technical Reports Server (NTRS)

    Belenov, E.; Isakov, V.; Nazarkin, A.

    1994-01-01

    Some features of the excitation of multilevel quantum systems under the action of electromagnetic pulses which are shorter than the inverse frequency of interlevel transitions are considered. It is shown that the interaction is characterized by a specific type of selectivity which is not connected with the resonant absorption of radiation. The simplest three-level model displays the inverse population of upper levels. The effect of an ultrashort laser pulse on a multilevel molecule was regarded as an instant reception of the oscillation velocity by the oscillator and this approach showed an effective excitation and dissociation of the molecule. The estimations testify to the fact that these effects can be observed using modern femtosecond lasers.

  5. Current Duplicating Processes

    ERIC Educational Resources Information Center

    Groneman, Nancy

    1978-01-01

    While business instructors are still teaching spirit and stencil duplicating processes, most businesses now use copiers or offset printing processes. The article discusses offset and copier skills needed by office workers, pointing out that the processes being taught should be compatible with those used in business. (MF)

  6. Duplication Is Ubiquitous

    ERIC Educational Resources Information Center

    Tenopir, Carol

    2005-01-01

    This article discusses how Phil Davis, Life Sciences Bibliographer at Cornell University, found duplicate articles in Emerald/MCB University Press journals. According to Davis, he has found hundreds of examples of the same article published in more than one journal in at least 73 Emerald/MCB journals over 30 years. This article gives the details…

  7. Perspectives on Program Duplication

    ERIC Educational Resources Information Center

    Morrison, Gail M.

    2010-01-01

    Concerns about program duplication in higher education are often reminiscent of Supreme Court Justice Potter Stewart's now famous remark about pornography: "I know it when I see it." The problem with that reaction is that, at least on its surface, this response seems intuitive and emotional, to say nothing of subjective and personal. The…

  8. Duplication Is Ubiquitous

    ERIC Educational Resources Information Center

    Tenopir, Carol

    2005-01-01

    This article discusses how Phil Davis, Life Sciences Bibliographer at Cornell University, found duplicate articles in Emerald/MCB University Press journals. According to Davis, he has found hundreds of examples of the same article published in more than one journal in at least 73 Emerald/MCB journals over 30 years. This article gives the details…

  9. A Duplicate Construction Experiment.

    ERIC Educational Resources Information Center

    Bridgeman, Brent

    This experiment was designed to assess the ability of item writers to construct truly parallel tests based on a "duplicate-construction experiment" in which Cronbach argues that if the universe description and sampling are ideally refined, the two independently constructed tests will be entirely equivalent, and that within the limits of item…

  10. Pulse Laser High Speed Schlieren Photographic System And Its Application

    NASA Astrophysics Data System (ADS)

    Yuju, Lin; Shicheng, Li; Qingyou, Wang; Wenjun, Ni; Yong, Xiang; Jingliang, Shi

    1989-06-01

    The sequential pulsed, Q-switched ruby laser is used for the light source. Liodel 640 schilieren apparatus is used for the display optical system of image and flow field. The access type rotating mirror scanning high speed camera is used for recording unit. They are assembled into a complete set of Pulsed Laser High Speed Schlieren Photographic System. So far, we have designed and trial-manufactured two types. The Model I system is used for recording the armor-piercing process of the terminal trajectory and the chamber-shooting process of the midway trajectory. The better results have been obtained. The Eodel II system is used for studying the detonating mechanism of high energy dynamite. The framing pictures of the bullet flying attitude before bullet collides the target and the compressive deformation after it collides the target as well as the detonating process have been taken. These photos have provided the basis for research work. The future development of the system has also been discussed in this paper.

  11. Pulse Analyzing System Using Optical Coherence Tomography for Oriental Medical Application

    NASA Astrophysics Data System (ADS)

    Jung, Unsang; Jeon, Mansik; Lee, Changho; Cho, Namhyun; Jeong, Hyosang; Na, Changsu; Kim, Jeehyun

    2011-05-01

    In oriental medicine, the pulse wave of a radial artery is a critical diagnosis factor. An oriental doctor puts a finger on the radial artery to sense the pulse wave of a radial artery. The pulse wave plays an important role because its shape, pressure, and duration determine the pathological status of a patient. Chongumaekbeop, which is a traditional technique for measuring the pulse by using a finger, is sometimes believed to be not reproducible due to the subjective judgment of the measurement location and pulse signal, so we performed a clinical experiment with a developed diagnosis equipment to produce quantitative and reproducible results. In this study, we measured the pulse wave of the radial artery and quantified the speed, intensity, and power of the pulse wave using optical coherence tomography (OCT). We confirmed the applicability of the developed system through an analysis of the pulse wave. We used two OCT systems whose measurement parameters are different because of the measurement limitation and analysis of vector components of pulse movement. We gathered 25 volunteers, compared and analyzed the experiment results with four oriental medicine doctors' diagnosis. The results showed an agreement of 88% in pulse speed, 64% in pulse intensity, and 72% in pulse power when comparing traditional measurements with the system using OCT. We confirmed the dynamical motion detection through the two-dimensional image to ensure the reproducibility of the developed system. Thus, if the OCT system is applied to pulse measurement systems in oriental medicine, it may partially substitute for traditional measurement methods.

  12. Image enhancement for underwater pulsed laser line scan imaging system

    NASA Astrophysics Data System (ADS)

    Ouyang, B.; Dalgleish, F. R.; Caimi, F. M.; Vuorenkoski, A. K.; Giddings, T. E.; Shirron, J. J.

    2012-06-01

    Recent progress in system hardware such as laser, photon detectors and other electronic and optical components resulted in significant improvement for the underwater serial laser imaging system. Nevertheless, during normal system operation, system issues such as laser instability, electronic noise, and environmental conditions such as imaging in highly turbid water can still put constraint on the performance of imager. In this work, post-processing to take advantage of the improvement hardware to further reduce image noise and enhance the image quality as a critical aspect of the overall system design is studied. A novel realization of the bilateral principle based image/pulse noise reduction and image deconvolution using point spread function (PSF) predicted with EODES radiative transfer model is used to implement the processing chain. The concept is further extended to a multichannel deconvolution to exploit the benefit offered by the new multi element PMT configuration developed in HBOI. Two datasets were used to test the developed techniques respectively.

  13. Pulsed plasma propulsion system for North-South stationkeeping

    NASA Technical Reports Server (NTRS)

    Guman, W. J.; Palumbo, D. J.

    1976-01-01

    A completely integrated pulsed plasma propulsion system for North-South stationkeeping has been developed. System testing on a thrust balance has provided following new results: (1) A simple, helically coiled, spring-fed propellant subsystem for 38,284 lb-s (166,000 N-S) total impulse is feasible; (2) The propulsive performance level is compatible with North-South stationkeeping requirements; (3) Power conditioning is as simple as that of the space flight proven microthruster system; (4) Vacuum compatible, high energy density capacitors (40 joules/lb) capacitors have been developed and tested as part of the system; (5) 10,000 lb-sec of total impulse has been generated. Future improvements will include reducing electrode erosion, improving the structural rigidity of the assembly and continuously operating the system until 37,000 lb-sec of total impulse have been generated.

  14. Compact rf polarizer and its application to pulse compression systems

    DOE PAGES

    Franzi, Matthew; Wang, Juwen; Dolgashev, Valery; ...

    2016-06-01

    We present a novel method of reducing the footprint and increasing the efficiency of the modern multi-MW rf pulse compressor. This system utilizes a high power rf polarizer to couple two circular waveguide modes in quadrature to a single resonant cavity in order to replicate the response of a traditional two cavity configuration using a 4-port hybrid. The 11.424 GHz, high-Q, spherical cavity has a 5.875 cm radius and is fed by the circularly polarized signal to simultaneously excite the degenerate TE114 modes. The overcoupled spherical cavity has a Q0 of 9.4×104 and coupling factor (β) of 7.69 thus providingmore » a loaded quality factor QL of 1.06×104 with a fill time of 150 ns. Cold tests of the polarizer demonstrated good agreement with the numerical design, showing transmission of -0.05 dB and reflection back to the input rectangular WR 90 waveguide less than -40 dB over a 100 MHz bandwidth. This novel rf pulse compressor was tested at SLAC using XL-4 Klystron that provided rf power up to 32 MW and generated peak output power of 205 MW and an average of 135 MW over the discharged signal. A general network analysis of the polarizer is discussed as well as the design and high power test of the rf pulse compressor.« less

  15. Evaluation of pulse power devices in electric vehicle propulsion systems

    NASA Astrophysics Data System (ADS)

    Burke, A. F.; Dowgiallo, E. J.

    The application of pulse power devices in electric vehicle propulsion systems to load level the main energy storage battery has been studied. Both high energy density capacitors (ultracapacitors) and high power density, bipolar batteries are considered. Computer simulations of vehicle operation with hybrid (two power source) powertrains indicated the energy storage capacities of the pulse power devices required to load level the main battery are 300 to 500 Wh for the capacitors and 5 to 10 Ah for the bipolar batteries can be reduced from 79 W/kg to about 40 W/kg depending on the vehicle gradeability (speed, percent grade, and length of grade) desired. Evaluation of the status of the technology for the pulse power devices indicated that for both devices, improvements in technology are needed before the devices can be used in EV applications. In the case of the ultracapacitor, the energy density of present devices are 1 to 2 Wh/kg. A minimum energy density of about 5 Wh/kg is needed for electric vehicle applications. Progress in increasing the energy density of ultracapacitors has been rapid in recent years and the prospects for meeting the 5 Wh/kg requirement for EVs appear to be good. For bipolar batteries, a minimum power density of 500 W/kg is needed and the internal resistance must be reduced by about a factor of ten from that found in present designs.

  16. Compact rf polarizer and its application to pulse compression systems

    NASA Astrophysics Data System (ADS)

    Franzi, Matthew; Wang, Juwen; Dolgashev, Valery; Tantawi, Sami

    2016-06-01

    We present a novel method of reducing the footprint and increasing the efficiency of the modern multi-MW rf pulse compressor. This system utilizes a high power rf polarizer to couple two circular waveguide modes in quadrature to a single resonant cavity in order to replicate the response of a traditional two cavity configuration using a 4-port hybrid. The 11.424 GHz, high-Q, spherical cavity has a 5.875 cm radius and is fed by the circularly polarized signal to simultaneously excite the degenerate T E114 modes. The overcoupled spherical cavity has a Q0 of 9.4 ×104 and coupling factor (β ) of 7.69 thus providing a loaded quality factor QL of 1.06 ×104 with a fill time of 150 ns. Cold tests of the polarizer demonstrated good agreement with the numerical design, showing transmission of -0.05 dB and reflection back to the input rectangular WR 90 waveguide less than -40 dB over a 100 MHz bandwidth. This novel rf pulse compressor was tested at SLAC using XL-4 Klystron that provided rf power up to 32 MW and generated peak output power of 205 MW and an average of 135 MW over the discharged signal. A general network analysis of the polarizer is discussed as well as the design and high power test of the rf pulse compressor.

  17. Voltage control in pulsed system by predict-ahead control

    DOEpatents

    Payne, A.N.; Watson, J.A.; Sampayan, S.E.

    1994-09-13

    A method and apparatus for predict-ahead pulse-to-pulse voltage control in a pulsed power supply system is disclosed. A DC power supply network is coupled to a resonant charging network via a first switch. The resonant charging network is coupled at a node to a storage capacitor. An output load is coupled to the storage capacitor via a second switch. A de-Q-ing network is coupled to the resonant charging network via a third switch. The trigger for the third switch is a derived function of the initial voltage of the power supply network, the initial voltage of the storage capacitor, and the present voltage of the storage capacitor. A first trigger closes the first switch and charges the capacitor. The third trigger is asserted according to the derived function to close the third switch. When the third switch is closed, the first switch opens and voltage on the node is regulated. The second trigger may be thereafter asserted to discharge the capacitor into the output load. 4 figs.

  18. Voltage control in pulsed system by predict-ahead control

    DOEpatents

    Payne, Anthony N.; Watson, James A.; Sampayan, Stephen E.

    1994-01-01

    A method and apparatus for predict-ahead pulse-to-pulse voltage control in a pulsed power supply system is disclosed. A DC power supply network is coupled to a resonant charging network via a first switch. The resonant charging network is coupled at a node to a storage capacitor. An output load is coupled to the storage capacitor via a second switch. A de-Q-ing network is coupled to the resonant charging network via a third switch. The trigger for the third switch is a derived function of the initial voltage of the power supply network, the initial voltage of the storage capacitor, and the present voltage of the storage capacitor. A first trigger closes the first switch and charges the capacitor. The third trigger is asserted according to the derived function to close the third switch. When the third switch is closed, the first switch opens and voltage on the node is regulated. The second trigger may be thereafter asserted to discharge the capacitor into the output load.

  19. Robotic system for remote maintenance of a pulsed nuclear reactor

    SciTech Connect

    Thunborg, S.

    1986-01-01

    Guidelines recently established for occupational radiation exposure specify that exposure should be as low as reasonably achievable. In conformance with these guidelines, SNL has developed a remote maintenance robot (RMR) system for use in the Sandia Pulse Reactor III (SPR III) facility. The RMR should reduce occupational radiation exposure by a factor of 4 and decrease reactor downtime. Other goals include developing a technology base for a more advanced pulse reactor and for the nuclear fuel cycle programs of the US Department of Energy and US Nuclear Regulatory Commission. The RMR has five major subsystems: (a) a chain-driven cart to bring the system into the reactor room; (b) a Puma 560 robot to perform dextrous operations; (c) a programmable turntable to orient the robot to any of the reactor's four sides; (d) a programmable overhead hoist for lifting components weighing up to 400 lb onto or off of the reactor; and (e) a supervisory control console for the system operator. Figure 1 is a schematic diagram of the turntable, hoist, and robot system in position around the SPR III reactor.

  20. Pulsed field magnetization in rare-earth kagome systems.

    PubMed

    Hoch, M J R; Zhou, H D; Mun, E; Harrison, N

    2016-02-03

    The rare-earth kagome systems R 3Ga5SiO14 (R  =  Nd or Pr) exhibit cooperative paramagnetism at low temperatures. Evidence for correlated spin clusters in these weakly frustrated systems has previously been obtained from neutron scattering and from ESR and NMR results. The present pulsed field (0-60 T, 25 ms) magnetization measurements made on single crystals of Nd3Ga5SiO14 (NGS) and Pr3Ga5SiO14 (PGS) at temperatures down to 450 mK have revealed striking differences in the magnetic responses of the two materials. For NGS the magnetization shows a low field plateau, saturation in high transient fields, and significant hysteresis while the PGS magnetization does not saturate in transient fields up to 60 T and shows no hysteresis or plateaus. Nd(3+) is a Kramers ion while Pr(3+) is a non-Kramers ion and the crystal field effects are quite different in the two systems. For the conditions used in the experiments the magnetization behavior is not in agreement with Heisenberg model predictions for kagome systems in which easy-axis anisotropy is much larger than the exchange coupling. The extremely slow spin dynamics found below 4 K in NGS is, however, consistent with the model for Kramers ions and provides a basis for explaining the pulsed field magnetization features.

  1. Portable radiation detection system for pulsed high energy photon sources

    SciTech Connect

    Harker, Y.D.; Lawrence, R.S.; Yoon, W.Y.

    1994-12-31

    Portable, battery-operated, radiation detection systems for measuring the intensity and energy characteristics of intense, pulsed photon sources (either high energy X-ray or gamma) have been developed at the Idaho National Engineering Laboratory. These field-deployable, suitcase-sized detection units are designed to measure and record the characteristics of a single radiation burst or multiple bursts from a pulsed ionizing radiation source. The recorded information can then be analyzed on a simple laptop computer at a location remote from the detection system and completely independent of the ongoing data acquisition process. Two detection unit designs are described. The first, called the MARK-1, has eight bismuth germanate (BGO) radiation detectors. Four of which are unshielded and have different thicknesses (diameters). The remaining four are the same size as the largest unshielded detector but have different thicknesses of lead shielding surrounding each detector. The second unit design, called the MARK-1 A, utilizes the same detection methodology as the MARK-1 but has ten BGO detectors instead of eight and utilizes a different method of amplifying detector signals enabling reduced overall size and weight of the detection unit. Both the detection system designs have sensitivity ranges from 3 x 10{sup {minus}9} cGy to 9 x 10{sup {minus}5} cGy per radiation burst. Experimental detection results will be presented and discussed along the systems` potential for commercial applications.

  2. A new 40 MA ranchero explosive pulsed power system

    SciTech Connect

    Goforth, James; Herrera, Dennis; Oona, Hank; Torres, David; Atchison, W L; Colgate, S A; Griego, J R; Guzik, J; Holtkamp, D B; Idzorek, G; Kaul, A; Kirkpatrick, R C; Menikoff, R; Reardon, P T; Reinovsky, R E; Rousculp, C L; Sgro, A G; Tabaka, L J; Tierney, T E; Watt, R G

    2009-01-01

    We are developing a new high explosive pulsed power (HEPP) system based on the 1.4 m long Ranchero generator which was developed in 1999 for driving solid density z-pinch loads. The new application requires approximately 40 MA to implode similar liners, but the liners cannot tolerate the 65 {micro}s, 3 MA current pulse associated with delivering the initial magnetic flux to the 200 nH generator. To circumvent this problem, we have designed a system with an internal start switch and four explosively formed fuse (EFF) opening switches. The integral start switch is installed between the output glide plane and the armature. It functions in the same manner as a standard input crowbar switch when armature motion begins, but initially isolates the load. The circuit is completed during the flux loading phase using post hole convolutes. Each convolute attaches the inner (coaxial) output transmission line to the outside of the outer coax through a penetration of the outer coaxial line. The attachment is made with the conductor of an EFF at each location. The EFFs conduct 0.75 MA each, and are actuated just after the internal start switch connects to the load. EFFs operating at these parameters have been tested in the past. The post hole convolutes must withstand as much as 80 kV at peak dl/dt during the Ranchero load current pulse. We describe the design of this new HEPP system in detail, and give the experimental results available at conference time. In addition, we discuss the work we are doing to test the upper current limits of a single standard size Ranchero module. Calculations have suggested that the generator could function at up to {approx}120 MA, the rule of thumb we follow (1 MA/cm) suggests 90 MA, and simple flux compression calculations, along with the {approx}4 MA seed current available from our capacitor bank, suggests 118 MA is the currently available upper limit.

  3. Control of pulse format in high energy per pulse all-fiber erbium/ytterbium laser systems

    NASA Astrophysics Data System (ADS)

    Klopfer, Michael; Block, Matthew K.; Deffenbaugh, James; Fitzpatrick, Zak G.; Urioste, Michael T.; Henry, Leanne J.; Jain, Ravinder

    2017-02-01

    A multi-stage linearly polarized (PM) (15 dB) pulsed fiber laser system at 1550 nm capable of operating at repetition rates between 3 and 20 kHz was investigated. A narrow linewidth seed source was linewidth broadened to approximately 20 GHz and pulses were created and shaped via an electro-optic modulator (EOM) in conjunction with a home built arbitrary waveform generator. As expected, a high repetition rate pulse train with a near diffraction limited beam quality (M2 1.12) was achieved. However, the ability to store energy was limited by the number of active ions within the erbium/ytterbium doped gain fiber within the various stages. As a result, the maximum energy per pulse achievable from the system was approximately 0.3 and 0.38 mJ for 300 ns and 1 μs pulses, respectively, at 3 kHz. Because the system was operated at high inversion, the erbium/ytterbium doped optical fiber preferred to lase at 1535 nm versus 1550 nm resulting in amplified spontaneous emission (ASE) both intra- and inter-pulse. For the lower power stages, the ASE was controllable via a EOM whose function was to block the energy between pulses as well as ASE filters whose purpose was to block spectral components outside of the 1550 nm passband. For the higher power stages, the pump diodes were pulsed to enable strategic placement of an inversion resulting in higher intrapulse energies as well as an improved spectrum of the signal. When optimized, this system will be used to seed higher power solid state amplifier stages.

  4. Integrated pulse stretchers for high-energy CPA and OPCPA systems

    NASA Astrophysics Data System (ADS)

    Shah, Lawrence; Bodnar, Nathan; Roumayah, Patrick; Webb, Benjamin; Bradford, Joshua; Richardson, Martin

    2016-03-01

    Pulse stretchers are critical components in chirped pulse amplification (CPA) and optical parametric CPA (OPCPA) laser systems. In CPA systems, pulse stretching and compression is typical accomplished using bulk diffraction gratings; however integrated devices such volume or fiber Bragg gratings can provide similar optical performance with significantly smaller footprint and simplified alignment. In this work, we discuss the use of such integrated devices to stretch a 100 fs pulse to 400 ps with customized third order dispersion for use in a multi-TW Ti:Sapphire system as well as integrated optics to control the pulse duration in pump lasers for OPCPA systems.

  5. Feedback stabilization system for pulsed single longitudinal mode tunable lasers

    DOEpatents

    Esherick, Peter; Raymond, Thomas D.

    1991-10-01

    A feedback stabilization system for pulse single longitudinal mode tunable lasers having an excited laser medium contained within an adjustable length cavity and producing a laser beam through the use of an internal dispersive element, including detection of angular deviation in the output laser beam resulting from detuning between the cavity mode frequency and the passband of the internal dispersive element, and generating an error signal based thereon. The error signal can be integrated and amplified and then applied as a correcting signal to a piezoelectric transducer mounted on a mirror of the laser cavity for controlling the cavity length.

  6. Dynamic pressure transducer system for pulsed plasma flow diagnosis.

    NASA Technical Reports Server (NTRS)

    York, T. M.; Mckenna, K. F.; Michels, C. J.

    1973-01-01

    The response characteristics of high sensitivity piezoelectric pressure transducers suitable for use in the plasma flow induced by megawatt-level electric discharges in low density (less than 1 Torr) gases are described. The uniquely designed probe records the initial impingement of a large magnitude total pressure pulse, followed by the flow of primary interest with order-of-magnitude smaller signals. Effects relating to probe and support accelerations, blast shielding and probe heating are evaluated and accounted for in a probe system with a sensitivity of 40 V/atm.

  7. Flow Characteristics of Pulse Cleaning System in Ceramic Filter

    SciTech Connect

    Zhongli, J.; Peng, S.; Chen, H.; Shi, M.

    2002-09-19

    The rigid ceramic filters have been recognized to be a most promising kind of equipment for the gas-solid separation and the cleaning of hot gases due to their unique properties and higher separation efficiency for larger than 5 {micro}m particles, which will well meet downstream system component protection and environmental standards. They have potential for increased efficiency in advanced coal-fired power generation systems like pressurized fluidized bed combustion (PFBC) and integrated gasification combined cycle (IGCC) process, and petrochemical process such as fluid catalyst cracking (FCC) Process. In the commercial utilization of rigid ceramic filters, the performance of pulse cleaning systems has crucial effects on the long-term structural durability and reliability of the entire design. In order to get a clear insight into the nature of this cleaning process and provide a solid basis for the industrial applications, the transient flow characteristics of the rigid ceramic candle filter during the whole pulse cleaning process should be completely analyzed.

  8. Pulsed laser linescanner for a backscatter absorption gas imaging system

    DOEpatents

    Kulp, Thomas J.; Reichardt, Thomas A.; Schmitt, Randal L.; Bambha, Ray P.

    2004-02-10

    An active (laser-illuminated) imaging system is described that is suitable for use in backscatter absorption gas imaging (BAGI). A BAGI imager operates by imaging a scene as it is illuminated with radiation that is absorbed by the gas to be detected. Gases become "visible" in the image when they attenuate the illumination creating a shadow in the image. This disclosure describes a BAGI imager that operates in a linescanned manner using a high repetition rate pulsed laser as its illumination source. The format of this system allows differential imaging, in which the scene is illuminated with light at least 2 wavelengths--one or more absorbed by the gas and one or more not absorbed. The system is designed to accomplish imaging in a manner that is insensitive to motion of the camera, so that it can be held in the hand of an operator or operated from a moving vehicle.

  9. Multi-channel, fiber-based seed pulse distribution system for femtosecond-level synchronized chirped pulse amplifiers

    NASA Astrophysics Data System (ADS)

    Horáček, Martin; Indra, Lukáš; Green, Jonathan T.; Naylon, Jack A.; Tykalewicz, Boguslaw; Novák, Jakub; Batysta, František; Mazanec, Tomáš; Horáček, Jakub; Antipenkov, Roman; Hubka, Zbyněk; Boge, Robert; Bakule, Pavel; Rus, Bedřich

    2017-01-01

    We report on the design and performance of a fiber-based, multi-channel laser amplifier seed pulse distribution system. The device is designed to condition and distribute low energy laser pulses from a mode-locked oscillator to multiple, highly synchronized, high energy amplifiers integrated into a laser beamline. Critical functions such as temporal pulse stretching well beyond 100 ps/nm, pulse picking, and fine control over the pulse delay up to 300 ps are all performed in fiber eliminating the need for bulky and expensive grating stretchers, Pockels cells, and delay lines. These functions are characterized and the system as a whole is demonstrated by seeding two high energy amplifiers in the laser beamline. The design of this system allows for complete computer control of all functions, including tuning of dispersion, and is entirely hands-free. The performance of this device and its subsystems will be relevant to those developing lasers where reliability, size, and cost are key concerns in addition to performance; this includes those developing large-scale laser systems similar to ours and also those developing table-top experiments and commercial systems.

  10. Multi-channel, fiber-based seed pulse distribution system for femtosecond-level synchronized chirped pulse amplifiers.

    PubMed

    Horáček, Martin; Indra, Lukáš; Green, Jonathan T; Naylon, Jack A; Tykalewicz, Boguslaw; Novák, Jakub; Batysta, František; Mazanec, Tomáš; Horáček, Jakub; Antipenkov, Roman; Hubka, Zbyněk; Boge, Robert; Bakule, Pavel; Rus, Bedřich

    2017-01-01

    We report on the design and performance of a fiber-based, multi-channel laser amplifier seed pulse distribution system. The device is designed to condition and distribute low energy laser pulses from a mode-locked oscillator to multiple, highly synchronized, high energy amplifiers integrated into a laser beamline. Critical functions such as temporal pulse stretching well beyond 100 ps/nm, pulse picking, and fine control over the pulse delay up to 300 ps are all performed in fiber eliminating the need for bulky and expensive grating stretchers, Pockels cells, and delay lines. These functions are characterized and the system as a whole is demonstrated by seeding two high energy amplifiers in the laser beamline. The design of this system allows for complete computer control of all functions, including tuning of dispersion, and is entirely hands-free. The performance of this device and its subsystems will be relevant to those developing lasers where reliability, size, and cost are key concerns in addition to performance; this includes those developing large-scale laser systems similar to ours and also those developing table-top experiments and commercial systems.

  11. Green and ultraviolet pulse generation with a compact, fiber laser, chirped-pulse amplification system for aerosol fluorescence measurements.

    PubMed

    Lou, Janet W; Currie, Marc; Sivaprakasam, Vasanthi; Eversole, Jay D

    2010-10-01

    We use a compact chirped-pulse amplified system to harmonically generate ultrashort pulses for aerosol fluorescence measurements. The seed laser is a compact, all-normal dispersion, mode-locked Yb-doped fiber laser with a 1050 nm center wavelength operating at 41 MHz. Average powers of more than 1.2 W at 525 nm and 350 mW at 262 nm are generated with <500 fs pulse durations. The pulses are time-stretched with high-dispersion fiber, amplified by a high-power, large-mode-area fiber amplifier, and recompressed using a chirped volume holographic Bragg grating. The resulting high-peak-power pulses allow for highly efficient harmonic generation. We also demonstrate for the first time to our knowledge, the use of a mode-locked ultraviolet source to excite individual biological particles and other calibration particles in an inlet air flow as they pass through an optical chamber. The repetition rate is ideal for biofluorescence measurements as it allows faster sampling rates as well as the higher peak powers as compared to previously demonstrated Q-switched systems while maintaining a pulse period that is longer than the typical fluorescence lifetimes. Thus, the fluorescence excitation can be considered to be quasicontinuous and requires no external synchronization and triggering.

  12. Green and ultraviolet pulse generation with a compact, fiber laser, chirped-pulse amplification system for aerosol fluorescence measurements

    NASA Astrophysics Data System (ADS)

    Lou, Janet W.; Currie, Marc; Sivaprakasam, Vasanthi; Eversole, Jay D.

    2010-10-01

    We use a compact chirped-pulse amplified system to harmonically generate ultrashort pulses for aerosol fluorescence measurements. The seed laser is a compact, all-normal dispersion, mode-locked Yb-doped fiber laser with a 1050 nm center wavelength operating at 41 MHz. Average powers of more than 1.2 W at 525 nm and 350 mW at 262 nm are generated with <500 fs pulse durations. The pulses are time-stretched with high-dispersion fiber, amplified by a high-power, large-mode-area fiber amplifier, and recompressed using a chirped volume holographic Bragg grating. The resulting high-peak-power pulses allow for highly efficient harmonic generation. We also demonstrate for the first time to our knowledge, the use of a mode-locked ultraviolet source to excite individual biological particles and other calibration particles in an inlet air flow as they pass through an optical chamber. The repetition rate is ideal for biofluorescence measurements as it allows faster sampling rates as well as the higher peak powers as compared to previously demonstrated Q-switched systems while maintaining a pulse period that is longer than the typical fluorescence lifetimes. Thus, the fluorescence excitation can be considered to be quasicontinuous and requires no external synchronization and triggering.

  13. Large-format automated pulsed holography camera system

    NASA Astrophysics Data System (ADS)

    Rodin, Alexey M.; Ratcliffe, David B.; Rus, Roman

    2001-04-01

    An automated pulsed holography camera system for ultra-large format display holography has been created. This camera produces reflection and rainbow copies of up to 110 X 150 cm size as well as master holograms of up to 80 X 100 cm size. In addition, the system is capable of generating digital full color transmission rainbow holograms from masters produced by a digital mastering machine. Camera utilizes the single longitudinal mode-phase conjugated laser delivering the pulses of 35 ns duration with maximum energy of 8 J at 526.5 nm wavelength. High output energy have conditioned the use of non-spherical spatial beam filtering in each beam pass. Camera incorporates instant switch-over from copying to mastering modes, permits digital electronic setting of all beam ratios and allows manual tuning of scene illuminating diffusers. Some of the most important applications of this camera are printing of AO format 3D-drawings for advanced virtual prototyping of machines & devices, large format scientific & artistic holography, 3D-posters printing industry of near future.

  14. Computer controlled MHD power consolidation and pulse generation system

    SciTech Connect

    Johnson, R.; Marcotte, K.; Donnelly, M.

    1990-01-01

    The major goal of this research project is to establish the feasibility of a power conversion technology which will permit the direct synthesis of computer programmable pulse power. Feasibility has been established in this project by demonstration of direct synthesis of commercial frequency power by means of computer control. The power input to the conversion system is assumed to be a Faraday connected MHD generator which may be viewed as a multi-terminal dc source and is simulated for the purpose of this demonstration by a set of dc power supplies. This consolidation/inversion (CI), process will be referred to subsequently as Pulse Amplitude Synthesis and Control (PASC). A secondary goal is to deliver a controller subsystem consisting of a computer, software, and computer interface board which can serve as one of the building blocks for a possible phase II prototype system. This report period work summarizes the accomplishments and covers the high points of the two year project. 6 refs., 41 figs.

  15. Coherent pulsed excitation of degenerate multistate systems: Exact analytic solutions

    SciTech Connect

    Kyoseva, E. S.; Vitanov, N. V.

    2006-02-15

    We show that the solution of a multistate system composed of N degenerate lower (ground) states and one upper (excited) state can be reduced by using the Morris-Shore transformation to the solution of a two-state system involving only the excited state and a (bright) superposition of ground states. In addition, there are N-1 dark states composed of ground states. We use this decomposition to derive analytical solutions for degenerate extensions of the most popular exactly soluble models: the resonance solution, the Rabi, Landau-Zener, Rosen-Zener, Allen-Eberly, and Demkov-Kunike models. We suggest various applications of the multistate solutions, for example, as tools for creating multistate coherent superpositions by generalized resonant {pi} pulses. We show that such generalized {pi} pulses can occur even when the upper state is far off resonance, at specific detunings, which makes it possible to operate in the degenerate ground-state manifold without populating the (possibly lossy) upper state, even transiently.

  16. Pulse-burst laser systems for fast Thomson scattering (invited)a)

    NASA Astrophysics Data System (ADS)

    Den Hartog, D. J.; Ambuel, J. R.; Borchardt, M. T.; Falkowski, A. F.; Harris, W. S.; Holly, D. J.; Parke, E.; Reusch, J. A.; Robl, P. E.; Stephens, H. D.; Yang, Y. M.

    2010-10-01

    Two standard commercial flashlamp-pumped Nd:YAG (YAG denotes yttrium aluminum garnet) lasers have been upgraded to "pulse-burst" capability. Each laser produces a burst of up to 15 2 J Q-switched pulses (1064 nm) at repetition rates of 1-12.5 kHz. Variable pulse-width drive (0.15-0.39 ms) of the flashlamps is accomplished by insulated gate bipolar transistor (IGBT) switching of electrolytic capacitor banks. Direct control of the laser Pockels cell drive enables optimal pulse energy extraction, and up to four 2 J laser pulses during one flashlamp pulse. These lasers are used in the Thomson scattering plasma diagnostic system on the MST reversed-field pinch to record the dynamic evolution of the electron temperature profile and temperature fluctuations. To further these investigations, a custom pulse-burst laser system with a maximum pulse repetition rate of 250 kHz is now being commissioned.

  17. A modularized pulse programmer for NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Mao, Wenping; Bao, Qingjia; Yang, Liang; Chen, Yiqun; Liu, Chaoyang; Qiu, Jianqing; Ye, Chaohui

    2011-02-01

    A modularized pulse programmer for a NMR spectrometer is described. It consists of a networked PCI-104 single-board computer and a field programmable gate array (FPGA). The PCI-104 is dedicated to translate the pulse sequence elements from the host computer into 48-bit binary words and download these words to the FPGA, while the FPGA functions as a sequencer to execute these binary words. High-resolution NMR spectra obtained on a home-built spectrometer with four pulse programmers working concurrently demonstrate the effectiveness of the pulse programmer. Advantages of the module include (1) once designed it can be duplicated and used to construct a scalable NMR/MRI system with multiple transmitter and receiver channels, (2) it is a totally programmable system in which all specific applications are determined by software, and (3) it provides enough reserve for possible new pulse sequences.

  18. Application of Yb:YAG short pulse laser system

    DOEpatents

    Erbert, Gaylen V.; Biswal, Subrat; Bartolick, Joseph M.; Stuart, Brent C.; Crane, John K.; Telford, Steve; Perry, Michael D.

    2004-07-06

    A diode pumped, high power (at least 20W), short pulse (up to 2 ps), chirped pulse amplified laser using Yb:YAG as the gain material is employed for material processing. Yb:YAG is used as the gain medium for both a regenerative amplifier and a high power 4-pass amplifier. A single common reflective grating optical device is used to both stretch pulses for amplification purposes and to recompress amplified pulses before being directed to a workpiece.

  19. Mach-Zehnder Recording Systems for Pulsed Power Diagnostics

    SciTech Connect

    Miller, E K; McKenna, I; Macrum, G; Baker, D; Tran, V; Rodriguez, E; Kaufman, M I; Tibbits, A; Silbernagel, C T; Waltman, T B; Herrmann, H W; Kim, Y H; Mack, J M; Young, C S; Caldwell, S E; Evans, S C; Sedillo, T J; Stoeffl, W; Grafil, E; Liebman, J; Beeman, B; Watts, P; Carpenter, A; Horsfied, C J; Rubery, M S; Chandler, G A; Torres, J A; Smelser, R M

    2012-10-01

    Fiber-optic transmission and recording systems, based on Mach-Zehnder modulators, have been developed and installed at the National Ignition Facility (NIF), and are being developed for other pulsed-power facilities such as Z-R at Sandia, with different requirements. We present the design and performance characteristics for the mature analog links, based on the system developed for the Gamma Reaction History (GRH) diagnostic at OMEGA and NIF. For a single detector channel, two Mach-Zehnders are used to provide high dynamic range at the full recording bandwidth with no gaps in the coverage. We present laboratory and shot data to estimate upper limits on the radiation effects as they impact recorded data quality. Finally, we will assess the technology readiness level for mature and developing implementations of Mach-Zehnder links for these environments.

  20. Mach-Zehnder recording systems for pulsed power diagnostics.

    PubMed

    Miller, E K; Abbott, R Q; McKenna, I; Macrum, G; Baker, D; Tran, V; Rodriguez, E; Kaufman, M I; Tibbits, A; Silbernagel, C T; Waltman, T B; Herrmann, H W; Kim, Y H; Mack, J M; Young, C S; Caldwell, S E; Evans, S C; Sedillo, T J; Stoeffl, W; Grafil, E; Liebman, J; Beeman, B; Watts, P; Carpenter, A; Horsfied, C J; Rubery, M S; Chandler, G A; Torres, J A; Smelser, R M

    2012-10-01

    Fiber-optic transmission and recording systems, based on Mach-Zehnder modulators, have been developed and installed at the National Ignition Facility (NIF), and are being developed for other pulsed-power facilities such as the Z accelerator at Sandia, with different requirements. We present the design and performance characteristics for the mature analog links, based on the system developed for the Gamma Reaction History diagnostic at the OMEGA laser and at NIF. For a single detector channel, two Mach-Zehnders are used to provide high dynamic range at the full recording bandwidth with no gaps in the coverage. We present laboratory and shot data to estimate upper limits on the radiation effects as they impact recorded data quality. Finally, we will assess the technology readiness level for mature and developing implementations of Mach-Zehnder links for these environments.

  1. Discrete pulse modulation strategies for high-frequency inverter systems

    NASA Astrophysics Data System (ADS)

    Venkataramanan, Giri; Divan, Deepakraj M.; Jahns, Thomas M.

    1993-07-01

    High-performance, high-frequency inverter systems for UPS (uninterruptible power system) applications cannot be easily realized using conventional hard-switched PWM inverter topologies. Adoption of typical soft-switched inverters such as the resonant dc link inverter require the use of discrete pulse modulation strategies. New controller structures are necessary to cope with stringent voltage regulation and distortion constraints in the presence of unbalanced and nonlinear loads. A controller that utilizes a load current feedforward strategy with a cost function current regulator to achieve excellent transient performance characteristics is presented. Voltage regulation is ensured using a synchronous frame regulator. Detailed simulation and experimental results verifying the concepts are presented. Although this work focuses on soft-switching inverters, the control concepts can be applied to conventional hard-switching inverters as well.

  2. Compact optical system for pulse-to-pulse laser beam quality measurement and applications in laser machining.

    PubMed

    Lambert, Robert W; Cortés-Martínez, Rodolpho; Waddle, Andrew J; Shephard, Jonathan D; Taghizadeh, Mohammad R; Greenaway, Alan H; Hand, Duncan P

    2004-09-10

    Fluctuations in beam quality (M2) have been observed on a pulse-to-pulse basis from an industrial Nd:YAG laser. This was achieved with a compact multiplane imaging method incorporating quadratically distorted diffraction gratings, which enabled simultaneous imaging of nine planes on a single CCD array. With this system, we measured across a range of beam qualities with an associated error (in M2 variation) of the order of 0.7%. Application of the system to fiber-optic beam delivery and laser drilling is demonstrated.

  3. A very high sensitivity RF pulse profile measurement system.

    SciTech Connect

    Christodoulou, Christos George; Lai, Jesse B.

    2009-06-01

    A technique for characterizing the pulse profile of a radio-frequency (RF) amplifier over a very wide power range under fast-pulsing conditions is presented. A pulse-modulated transmitter is used to drive a device under test (DUT) with a phase-coded signal that allows for an increased measurement range beyond standard techniques. A measurement receiver that samples points on the output pulse power profile and performs the necessary signal processing and coherent pulse integration, improving the detectability of low-power signals, is described. The measurement technique is applied to two sample amplifiers under fast-pulsing conditions with a pulsewidth of 250 ns at 3-GHz carrier frequency. A full measurement range of greater than 160 dB is achieved, extending the current state of the art in pulse-profiling techniques.

  4. Coherent transient phenomena in quantum systems by spatially shaping femtosecond optical pulses

    SciTech Connect

    El Gawhary, Omar; Pereira, Silvania F.; Urbach, H. Paul

    2011-03-15

    Providing a femtosecond optical pulse with a proper transverse spatial profile represents a fast and relatively simple method to force a quantum system to follow a prescribed temporal evolution. In the present work, we show that the quantum system presents a surprisingly high sensitivity with respect to the spatial shape of the pulse. We discuss an explicit example where differences on the order of a few nanometers in the initial pulse's spot size induce completely different responses in the system under study.

  5. Discrete pulse modulation strategies for high-frequency inverter systems

    SciTech Connect

    Venkataramanan, G. . Dept. of Electrical Engineering); Divan, D.M. . Dept. of Electrical and Computer Engineering); Jahns, T.M. )

    1993-07-01

    High-performance high-frequency inverter systems for UPS applications represent a demanding application that cannot be easily realized using conventional hard-switched PWM inverter topologies. Adoption of typical soft-switched inverters such as the resonant dc link inverter require the use of discrete pulse modulation strategies. New controller structures are necessary to cope with stringent voltage regulation and distortion constraints in the presence of unbalanced and nonlinear loads. This paper presents a controller that utilizes load current feed-forward strategy with a cost function current regulator to achieve excellent transient performance characteristics. Voltage regulation is ensured using a synchronous frame regulator. Detailed simulation and experimental results verifying the concepts are presented. Although this paper focuses on soft-switching inverters, the control concepts can be applied to conventional hard-switching inverters as well.

  6. Integrated systems for pulsed-power driven inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Cuneo, M. E.; Slutz, S. A.; Stygar, W. A.; Herrmann, M. C.; Sinars, D. B.; McBride, R. D.; Vesey, R. A.; Sefkow, A. B.; Mazarakis, M. G.; Vandevender, J. P.; Waisman, E. M.; Hansen, D. L.; Owen, A. C.; Jones, J. F.; Romero, J. A.; McKenney, J.

    2011-10-01

    Pulsed power fusion concepts integrate: (i) directly-magnetically-driven fusion targets that absorb large energies (10 MJ), (ii) efficient, rep-rated driver modules, (iii) compact, scalable, integrated driver architectures, (iv) driver-to-target coupling techniques with standoff and driver protection, and (v) long lifetime fusion chambers shielded by vaporizing blankets and thick liquid walls. Large fusion yields (3-30 GJ) and low rep-rates (0.1-1 Hz) may be an attractive path for IFE. Experiments on the ZR facility are validating physics issues for magnetically driven targets. Scientific breakeven (fusion energy = fuel energy) may be possible in the next few years. Plans for system development and integration will be discussed. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  7. EAP hydrogels for pulse-actuated cell system (PACS) architectures

    NASA Astrophysics Data System (ADS)

    Plata, R. Erik; Rogers, Hallena R.; Banister, Mark; Vohnout, Sonia; McGrath, Dominic V.

    2007-04-01

    Electroactuated polymer (EAP) hydrogels based on JEFFAMINE® T-403 and ethylene glycol glycidyl ether (EGDGE) are used in an infusion pump based on the proprietary Pulse Actuated Cell System (PACS) architecture in development at Medipacs LLC. We report here significant progress in optimizing the formulation of the EAP hydrogels to dramatically increase hydrolytic stability and reproducibility of actuation response. By adjusting the mole fraction of reactive components of the formulation and substituting higher molecular weight monomers, we eliminated a large degree of the hydrolytic instability of the hydrogels, decreased the brittleness of the gel, and increased the equilibrium swelling ratio. The combination of these two modifications to the formulation resulted in hydrogels that exhibited reproducible swelling and deswelling in response to pH for a total period of 10-15 hours.

  8. JET x-ray pulse-height analysis system

    SciTech Connect

    Pasini, D.; Gill, R.D.; Holm, J.; van der Goot, E.; Weller, A.

    1988-05-01

    The pulse-height-analysis (PHA) system installed on the Joint European Torus (JET) measures the plasma soft x-ray emission (2--30 keV) with an energy resolution of 450 eV and a time resolution of 200 ms. This diagnostic includes three Si(Li) detectors, equipped with sets of remotely controlled apertures and filters, which view the plasma in the midhorizontal plane of the torus along a single tangential line of sight. Automatic analysis of the spectra yields the central electron temperature, the central concentrations of chlorine, chromium, and nickel, and Z/sub eff/. Simulations of the measured spectra using a radiation code provides the basis to construct a consistent picture of the soft x-ray emission in the central region of JET plasmas.

  9. Water depth measurement using an airborne pulsed neon laser system

    SciTech Connect

    Hoge, F.E.; Swift, R.N.; Frederick, E.B.

    1980-03-15

    Initial base-line field test performance results of the National Aeronautics and Space Administration's airborne oceanographic lidar (AOL) in the bathymetry mode are presented. Flight tests over the Atlantic Ocean yielded water depth measurements to 10 m. Water depths to 4.6 m were measured in the more turbid Chesapeake Bay. Water-truth measurements of depth and beam attenuation coefficients by boat were taken at the same time as the air craft overflights to aid in determining the system's operational performance. Beam attenuation coefficient and depth d product d was established early in the program as the performance criterion index. A performance product of 6 was determined to be the goal. This performance goal was successfully met or exceeded in the large number of field tests executed. Included are selected data from nadir-angle tests conducted at 0, 5, 10, and 15. Field-of-view data chosen from the 2-, 5-, 10-, and 20-mrad tests are also presented. Depth measurements obtained to altitudes of 456 m are given for additional comparison. This laser bathymetry system represents a significant improvement over prior models in that (1) the complete surface-to-bottom pulse waveform is digitally recorded on magnetic tape at a rate of 400 pulse waveforms/sec, and (2) wide-swath mapping data may be routinely acquired using the 30 full-angle conical scanner. Space does not allow all the 5,000,000 laser soundings to be included. Qualified interested users may obtain complete data sets for their own in-depth analysis. 15 references, 9 figures, 1 table.

  10. Quantum dynamics of a two-state system induced by a chirped zero-area pulse

    NASA Astrophysics Data System (ADS)

    Lee, Han-gyeol; Song, Yunheung; Kim, Hyosub; Jo, Hanlae; Ahn, Jaewook

    2016-02-01

    It is well known that area pulses make Rabi oscillation and chirped pulses in the adiabatic interaction regime induce complete population inversion of a two-state system. Here we show that chirped zero-area pulses could engineer an interplay between the adiabatic evolution and Rabi-like rotations. In a proof-of-principle experiment utilizing spectral chirping of femtosecond laser pulses with a resonant spectral hole, we demonstrate that the chirped zero-area pulses could induce, for example, complete population inversion and return of the cold rubidium atom two-state system. Experimental result agrees well with the theoretically considered overall dynamics, which could be approximately modeled to a Ramsey-like three-pulse interaction, where the x and z rotations are driven by the hole and the main pulse, respectively.

  11. Taking the Pulse of a Black Hole System

    NASA Astrophysics Data System (ADS)

    2011-01-01

    Using two NASA X-ray satellites, astronomers have discovered what drives the "heartbeats" seen in the light from an unusual black hole system. These results give new insight into the ways that black holes can regulate their intake and severely curtail their growth. This study examined GRS 1915+105 (GRS 1915 for short), a binary system in the Milky Way galaxy containing a black hole about 14 times more massive than the Sun that is feeding off material from a companion star. As this material falls towards the black hole, it forms a swirling disk that emits X-rays. The black hole in GRS 1915 has been estimated to rotate at the maximum possible rate, allowing material in the inner disk to orbit very close to the black hole, at a radius only 20% larger than the event horizon, where the material travels at 50% the speed of light. Using the Chandra X-ray Observatory and the Rossi X-ray Timing Explorer (RXTE), researchers monitored this black hole system over a period of eight hours. As they watched, GRS 1915 gave off a short, bright pulse of X-ray light approximately every 50 seconds, varying in brightness by a factor of about three. This type of rhythmic cycle closely resembles an electrocardiogram of a human heart -- though at a slower pace. "Trying to understand the physics of this 'heartbeat state' is a little like trying to understand how a person's heart beats by watching changes in the blood flow through their veins," said Joey Neilsen, a graduate student at Harvard University, who presented these results from his dissertation at the American Astronomical Society (AAS) meeting in Seattle, Wash. It was previously known that GRS 1915 can develop such heartbeats when its mass consumption rate is very high. After monitoring it with the special combination of Chandra and RXTE, Neilsen and his collaborators realized that they could use the pulses to figure out what controls how much material the black hole consumes. "With each beat, the black hole pumps an enormous

  12. Interaction of a finite train of short pulses with an atomic ladder system

    SciTech Connect

    Jang, H. U.; Lomsadze, B.; Trachy, M. L.; Veshapidze, G.; Fehrenbach, C. W.; DePaola, B. D.

    2010-10-15

    When a train of optical pulses interacts with a medium, the time between pulses and the pulse-to-pulse phase jump have a profound effect on the outcome of the interaction. For a near-infinite train of regularly separated pulses having a constant pulse-to-pulse phase jump, as in the output of a frequency comb laser interacting with a ladder system, excitation of that system has been previously calculated and compared with experiment. In that case, the number of pulses in the train is very large, and the energy per pulse is very small. In the present work, the other extreme is experimentally examined: A small number of regularly spaced optical pulses are made to interact with a three-level ladder system in atomic rubidium. The pulses have been amplified, possibly placing the interactions into a nonperturbative regime. The experimental results are compared to a simple intuitive model and found to be in good general agreement. However, some aspects of the experimental results seem to be at odds with the simple model.

  13. Modular Pulsed Plasma Electric Propulsion System for Cubesats

    NASA Technical Reports Server (NTRS)

    Perez, Andres Dono; Gazulla, Oriol Tintore; Teel, George Lewis; Mai, Nghia; Lukas, Joseph; Haque, Sumadra; Uribe, Eddie; Keidar, Michael; Agasid, Elwood

    2014-01-01

    Current capabilities of CubeSats must be improved in order to perform more ambitious missions. Electric propulsion systems will play a key role due to their large specific impulse. Compared to other propulsion alternatives, their simplicity allows an easier miniaturization and manufacturing of autonomous modules into the nano and pico-satellite platform. Pulsed Plasma Thrusters (PPTs) appear as one of the most promising technologies for the near term. The utilization of solid and non-volatile propellants, their low power requirements and their proven reliability in the large scale make them great candidates for rapid implementation. The main challenges are the integration and miniaturization of all the electronic circuitry into a printed circuit board (PCB) that can satisfy the strict requirements that CubeSats present. NASA Ames and the George Washington University have demonstrated functionality and control of three discrete Micro-Cathode Arc Thrusters (CAT) using a bench top configuration that was compatible with the ARC PhoneSat Bus. This demonstration was successfully conducted in a vaccum chamber at the ARC Environmental Test Laboratory. A new effort will integrate a low power Plasma Processing Unit and two plasma thrusters onto a single printed circuit board that will utilize less than 13 U of Bus volume. The target design will be optimized for the accommodation into the PhoneSatEDISON Demonstration of SmallSatellite Networks (EDSN) bus as it uses the same software interface application, which was demonstrated in the previous task. This paper describes the design, integration and architecture of the proposed propulsion subsystem for a planned Technology Demonstration Mission. In addition, a general review of the Pulsed Plasma technology available for CubeSats is presented in order to assess the necessary challenges to overcome further development.

  14. Pulsed photoacoustic flow imaging with a handheld system.

    PubMed

    van den Berg, Pim J; Daoudi, Khalid; Steenbergen, Wiendelt

    2016-02-01

    Flow imaging is an important technique in a range of disease areas, but estimating low flow speeds, especially near the walls of blood vessels, remains challenging. Pulsed photoacoustic flow imaging can be an alternative since there is little signal contamination from background tissue with photoacoustic imaging. We propose flow imaging using a clinical photoacoustic system that is both handheld and portable. The system integrates a linear array with 7.5 MHz central frequency in combination with a high-repetition-rate diode laser to allow high-speed photoacoustic imaging--ideal for this application. This work shows the flow imaging performance of the system in vitro using microparticles. Both two-dimensional (2-D) flow images and quantitative flow velocities from 12 to 75  mm/s were obtained. In a transparent bulk medium, flow estimation showed standard errors of ∼7% the estimated speed; in the presence of tissue-realistic optical scattering, the error increased to 40% due to limited signal-to-noise ratio. In the future, photoacoustic flow imaging can potentially be performed in vivo using fluorophore-filled vesicles or with an improved setup on whole blood.

  15. High-Power Multimode X-Band RF Pulse Compression System for Future Linear Colliders

    SciTech Connect

    Tantawi, S.G.; Nantista, C.D.; Dolgashev, V.A.; Pearson, C.; Nelson, J.; Jobe, K.; Chan, J.; Fant, K.; Frisch, J.; Atkinson, D.; /LLNL, Livermore

    2005-08-10

    We present a multimode X-band rf pulse compression system suitable for a TeV-scale electron-positron linear collider such as the Next Linear Collider (NLC). The NLC main linac operating frequency is 11.424 GHz. A single NLC rf unit is required to produce 400 ns pulses with 475 MW of peak power. Each rf unit should power approximately 5 m of accelerator structures. The rf unit design consists of two 75 MW klystrons and a dual-moded resonant-delay-line pulse compression system that produces a flat output pulse. The pulse compression system components are all overmoded, and most components are designed to operate with two modes. This approach allows high-power-handling capability while maintaining a compact, inexpensive system. We detail the design of this system and present experimental cold test results. We describe the design and performance of various components. The high-power testing of the system is verified using four 50 MW solenoid-focused klystrons run off a common 400 kV solid-state modulator. The system has produced 400 ns rf pulses of greater than 500 MW. We present the layout of our system, which includes a dual-moded transmission waveguide system and a dual-moded resonant line (SLED-II) pulse compression system. We also present data on the processing and operation of this system, which has set high-power records in coherent and phase controlled pulsed rf.

  16. Nanosecond double-pulse fiber laser with arbitrary sub-pulse combined based on a spectral beam combining system

    NASA Astrophysics Data System (ADS)

    Hu, Man; Zheng, Ye; Yang, Yifeng; Chen, Xiaolong; Liu, Kai; Zhao, Chun; Wang, Jianhua; Qi, Yunfeng; He, Bing; Zhou, Jun

    2017-05-01

    In order to improve the processing efficiency and quality of nanosecond pulse laser drilling, a new double-pulse technique is put forward. Two single pulse lasers with different pulse duration or different repetition rate are spectrally combined by a home-made polarization-independent multilayer dielectric reflective diffraction grating. The pulse energy of single lasers and the inter-pulse separation can both be set at one's option. Then, double-pulse lasers represent two closely conjoint pulses with tunable pulse duration and tunable repetition rate and tunable pulse energy and tunable inter-pulse separation are obtained.

  17. Coherent excitation of a two-state system by a train of short pulses

    NASA Astrophysics Data System (ADS)

    Vitanov, Nikolay V.; Knight, Peter L.

    1995-09-01

    A theoretical nonperturbative study of the coherent excitation of a two-state system by N consecutive equally spaced identical pulses is presented. General relations between the evolution matrix elements in the cases of one and N pulses are obtained in a closed form. For pulse envelopes allowing analytical solutions, these relations enable analytical treatment of pulse-train excitation; for pulses that can only be treated numerically, they shorten the computations by a factor of N. The relations show that the multiple-pulse excitation of a two-state system can be considered as a quantum analog of the diffraction grating. The interaction dynamics substantially depends on the way the train is produced because the phase shift that is accumulated by the probability amplitudes due to the free evolution of the system during and between the pulses differs. In the limit of weak excitation, the results recover earlier conclusions based on perturbative treatments. Simple formulas are derived for the conditions for complete population inversion (CPI) and complete population return (CPR), which differ from the single-pulse ones. These general results are applied to four particular cases that allow analytical solutions: resonant, rectangular, Rosen-Zener, and Allen-Eberly pulses. A common feature in all these cases is that the number and the amplitude of oscillations in the state populations increase with the number of pulses, while their width decreases. For rectangular pulses, CPI is possible below a given value of the ratio between the detuning and the pulse area; this value increases nearly linearly with the number of pulses. For the Rosen-Zener model, CPI is found to be possible for two and more pulses, while it is impossible for a single non-resonant pulse. It is shown that for a given number of pulses there is an upper limit on the detuning for which CPI can be observed; this limit increases logarithmically with the number of pulses. For the Allen-Eberly model, CPR is

  18. A Hydrocarbon Fuel Flash Vaporization System for a Pulsed Detonation Engine

    DTIC Science & Technology

    2006-12-01

    Experiments were performed in the Air Force Research Laboratory (AFRL) Pulsed Detonation Research Facility at Wright Patterson AFB, Ohio. The PDE ...AFRL-MN-EG-TP-2006-7420 A HYDROCARBON FUEL FLASH VAPORIZATION SYSTEM FOR A PULSED DETONATION ENGINE (PREPRINT) K. Colin Tucker...85,7<&/$66,),&$7,212) E7(/(3+21(180%(5 ,QFOXGHDUHDFRGH A Hydrocarbon Fuel Flash Vaporization System for a Pulsed Detonation Engine K

  19. SONOTECH, INC. FREQUENCY-TUNABLE PULSE COMBUSTION SYSTEM (CELLO PULSE BURNER) - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    EPA Science Inventory

    Sonotech, Inc. (Sonotech) of Atlanta, Georgia, has developed a pulse combustion burner technology that claims to offer benefits when applied in a variety of combustion processes. The technology incorporates a combustor that can be tuned to induce large-amplitude acoustic or soni...

  20. SONOTECH, INC. FREQUENCY-TUNABLE PULSE COMBUSTION SYSTEM (CELLO PULSE BURNER) - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    EPA Science Inventory

    Sonotech, Inc. (Sonotech) of Atlanta, Georgia, has developed a pulse combustion burner technology that claims to offer benefits when applied in a variety of combustion processes. The technology incorporates a combustor that can be tuned to induce large-amplitude acoustic or soni...

  1. Duplicated middle cerebral artery.

    PubMed

    Perez, Jesus; Machado, Calixto; Scherle, Claudio; Hierro, Daniel

    2009-01-01

    Duplicated middle cerebral artery (DMCA) is an anomalous vessel arising from the internal carotid artery. The incidence DMCA is relatively law, and an association between this anomaly and cerebral aneurysms has been documented. There is a controversy whether DMCA may have perforating arteries. This is an important fact to consider in aneurysm surgery. We report the case of a 34-year-old black woman who suffered a subarachnoid hemorrhage and the angiography a left DMCA, and an aneurysm in an inferior branch of the main MCA. The DMCA and the MCA had perforating arteries. The aneurysm was clipped without complications. The observation of perforating arteries in our patient confirms that the DMCA may have perforating arteries. This is very important to be considered in cerebral aneurysms surgery. Moreover, the DMCA may potentially serve as a collateral blood supply to the MCA territory in cases of MCA occlusion.

  2. High precision laser direct microstructuring system based on bursts of picosecond pulses

    NASA Astrophysics Data System (ADS)

    Mur, Jaka; Petelin, Jaka; Osterman, Natan; Petkovšek, Rok

    2017-08-01

    We have developed an efficient, high precision system for direct laser microstructuring using fiber laser generated bursts of picosecond pulses. An advanced opto-mechanical system for beam deflection and sample movement, precise pulse energy control, and a custom built fiber laser with the pulse duration of 65 ps have been combined in a compact setup. The setup allows structuring of single-micrometer sized objects with a nanometer resolution of the laser beam positioning due to a combination of acousto-optical laser beam deflection and tight focusing. The precise synchronization of the fiber laser with the pulse burst repetition frequency of up to 100 kHz allowed a wide range of working parameters, including a tuneable number of pulses in each burst with the intra-burst repetition frequency of 40 MHz and delivering exactly one burst of pulses to every chosen position. We have demonstrated that tightly focused bursts of pulses significantly increase the ablation efficiency during the microstructuring of a copper layer and shorten the typical processing time compared to the single pulse per spot regime. We have used a simple short-pulse ablation model to describe our single pulse ablation data and developed an upgrade to the model to describe the ablation with bursts. Bursts of pulses also contribute to a high quality definition of structure edges and sides. The increased ablation efficiency at lower pulse energies compared to the single pulse per spot regime opens a window to utilize compact fiber lasers designed to operate at lower pulse energies, reducing the overall system complexity and size.

  3. Application and opportunities of pulses in food system: a review.

    PubMed

    Asif, Muhammad; Rooney, Lloyd W; Ali, Rashida; Riaz, Mian N

    2013-01-01

    Pulses are highly nutritious seeds of pod-bearing leguminous plants, specifically dry peas, lentils, and chickpeas. US farmers harvest about 2.6 million pounds of pulses every year but 75% of this is being exported internationally because of its increased consumption in the developing countries. In the current scenario, increasing costs of production, bad economy, and fluctuating food commodity prices have made a strong case for US producers to seek opportunities to increase domestic consumption of pulses through value-added products. Pulses are the richest sources of plant proteins and provide approximately 10% of the total dietary requirements of the proteins world over. Pulses are also high in dietary fibers and complex carbohydrates leading to low GI (glycemic index) foods. Pulses help to lower cholesterol and triglycerides as leguminous fibers are hypoglycosuria because of consisting more amylose than amylopectin. Pulses provide tremendous opportunities to be utilized in the processed foods such as bakery products, bread, pasta, snack foods, soups, cereal bar filing, tortillas, meat, etc. These show excellent opportunities in frozen dough foods either as added flour or as fillings. Pulses in view of their nutrient profile, seem to be ideal for inclusion in designing snack foods, baby, and sports foods.

  4. Miniature pulsed magnet system for synchrotron x-ray measurements

    SciTech Connect

    Linden, Peter J. E. M. van der; Mathon, Olivier; Strohm, Cornelius; Sikora, Marcin

    2008-07-15

    We have developed a versatile experimental apparatus for synchrotron x-ray measurements in pulsed high magnetic fields. The apparatus consists of a double cryostat incorporating a liquid nitrogen bath to cool the miniature pulsed coil and an independent helium flow cryostat allowing sample temperatures from 4 up to 250 K. The high duty cycle miniature pulsed coils can generate up to 38 T. During experiments at 30 T a repetition rate of 6 pulses/min was routinely reached. Using a 4 kJ power supply, the pulse duration was between 500 {mu}s and 1 ms. The setup was used for nuclear forward scattering measurements on {sup 57}Fe up to 25 T on the ESRF beamline ID18. In another experiment, x-ray magnetic circular dichroism was measured up to 30 T on the ESRF energy dispersive beamline ID24.

  5. Tunable CO2 laser system with subnanosecond-pulse-train output

    NASA Astrophysics Data System (ADS)

    Kimura, W. D.

    2017-02-01

    A CO2 laser system has been demonstrated that generates a train of subnanosecond pulses tunable over the P and R branches of the CO2 laser spectrum at 9-11 μm. It utilizes optical free induction decay to generate a single 100-ps laser pulse from a tunable transverse-excited-atmospheric CO2 laser. This laser pulse is injection-seeded into a high-pressure CO2 oscillator whose output consists of a train of amplified 100-ps pulses with maximum pulse energy of 30 mJ, corresponding to a peak power of 300 MW. The 100-ps, tunable, infrared laser pulses are needed for a new technique to remotely detect atmospheric gaseous molecules, which relies on the train of CO2 laser pulses selectively exciting the target molecules whose presence is then revealed using a separate terahertz probe beam.

  6. Instrumentation of Dynamic Gas Pulse Loading system. Final technical report

    SciTech Connect

    Mohaupt, H.

    1993-07-31

    The Dynamic Gas Pulse Loading (DGPL) process is an hydraulic fracturing method which uses CO{sub 2} and CO gas as a working fluid instead of a liquid. The DGPL system can be used to generate fractures for horizontal and vertical oil and gas well completions in both open hole and perforated casing. The DGPL system provides a cost effective tool for repairing near well bore permeability damage caused by inappropriate chemical treatment, migrating fines and paraffins, or slotted liners blocked by sand. Because the gas is generated from a solid propellant material by chemical reaction, no heavy equipment is required. Tremendous pump rates can be obtained. Peak pressures are naturally localized at the tool position by the tamping effect of well fluids. Thus many of the leakage and sealing problems which plague static hydrofrac processes ore completely avoided. DGPL may be effectively used before acid treatment to provide fresh pathways for the acid to reach the formation. The smaller tools may be positioned by wireline, though most Stressfrac tools are tubing conveyed.

  7. Selective RF pulses in NMR and their effect on coupled and uncoupled spin systems

    NASA Astrophysics Data System (ADS)

    Slotboom, J.

    1993-10-01

    This thesis describes various aspects of the usage of shaped RF-pulses for volume selection and spectral editing. Contents: Introduction--The History of Magnetic Resonance in a Nutshell, and The Usage of RF Pulses in Contemporary MRS and MRI; Theoretical and Practical Aspects of Localized NMR Spectroscopy; The Effects of RF Pulse Shape Discretization on the Spatially Selective Performance; Design of Frequency-Selective RF Pulses by Optimizing a Small Number of Pulse Parameters; A Single-Shot Localization Pulse Sequence Suited for Coils with Inhomogeneous RF Fields Using Adiabatic Slice-Selective RF Pulses; The Bloch Equations for an AB System and the Design of Spin State Selective RF Pulses for Coupled Spin Systems; The Effects of Frequency Selective RF Pulses on J Coupled Spin-1/2 Systems; A Quantitative (1)H MRS in vivo Study of the Effects of L-Ornithine-L-Aspartate on the Development of Mild Encephalopathy Using a Single Shot Localization Technique Based on SAR Reduced Adiabatic 2(pi) Pulses.

  8. Duplicated laboratory tests: evaluation of a computerized alert intervention abstract.

    PubMed

    Bridges, Sharon A; Papa, Linda; Norris, Anne E; Chase, Susan K

    2014-01-01

    Redundant testing contributes to reductions in healthcare system efficiency. The purpose of this study was to: (1) determine if the use of a computerized alert would reduce the number and cost of duplicated Acute Hepatitis Profile (AHP) laboratory tests and (2) assess what patient, test, and system factors were associated with duplication. This study used a quasi-experimental pre- and post-test design to determine the proportion of duplication of the AHP test before and after implementation of a computerized alert intervention. The AHP test was duplicated if the test was requested again within 15 days of the initial test being performed and the result present in the medical record. The intervention consisted of a computerized alert (pop-up window) that indicated to the clinician that the test had recently been ordered. A total of 674 AHP tests were performed in the pre-intervention period and 692 in the postintervention group. In the pre-intervention period, 53 (7.9%) were duplicated and in postintervention, 18 (2.6%) were duplicated (p<.001). The implementation of the alert was shown to significantly reduce associated costs of duplicated AHP tests (p≤.001). Implementation of computerized alerts may be useful in reducing duplicate laboratory tests and improving healthcare system efficiency. © 2012 National Association for Healthcare Quality.

  9. Genome-wide identification, phylogeny, duplication, and expression analyses of two-component system genes in Chinese cabbage (Brassica rapa ssp. pekinensis).

    PubMed

    Liu, Zhenning; Zhang, Mei; Kong, Lijun; Lv, Yanxia; Zou, Minghua; Lu, Gang; Cao, Jiashu; Yu, Xiaolin

    2014-08-01

    In plants, a two component system (TCS) composed of sensor histidine kinases (HKs), histidine phosphotransfer proteins (HPs), and response regulators (RRs) has been employed in cytokinin signal transduction. A TCS exhibits important functions in diverse biological processes, including plant growth, development, and response to environmental stimuli. Conducting an exhaustive search of the Chinese cabbage genome, a total of 20 HK(L) (11 HKs and 9 HKLs), 8 HP (7 authentic and 1 pseudo), and 57 RR (21 Type-A, 17 Type-B, 4 Type-C, and 15 pseudo) proteins were identified. The structures, conserved domains, and phylogenetic relationships of these protein-coding genes were analysed in detail. The duplications, evolutionary patterns, and divergence of the TCS genes were investigated. The transcription levels of TCS genes in various tissues, organs, and developmental stages were further analysed to obtain information of the functions of these genes. Cytokinin-related binding elements were found in the putative promoter regions of Type-A BrRR genes. Furthermore, gene expression patterns to adverse environmental stresses (drought and high salinity) and exogenous phytohormones (tZ and ABA) were investigated. Numerous stress-responsive candidate genes were obtained. Our systematic analyses provided insights into the characterization of the TCS genes in Chinese cabbage and basis for further functional studies of such genes.

  10. Genome-Wide Identification, Phylogeny, Duplication, and Expression Analyses of Two-Component System Genes in Chinese Cabbage (Brassica rapa ssp. pekinensis)

    PubMed Central

    Liu, Zhenning; Zhang, Mei; Kong, Lijun; Lv, Yanxia; Zou, Minghua; Lu, Gang; Cao, Jiashu; Yu, Xiaolin

    2014-01-01

    In plants, a two component system (TCS) composed of sensor histidine kinases (HKs), histidine phosphotransfer proteins (HPs), and response regulators (RRs) has been employed in cytokinin signal transduction. A TCS exhibits important functions in diverse biological processes, including plant growth, development, and response to environmental stimuli. Conducting an exhaustive search of the Chinese cabbage genome, a total of 20 HK(L) (11 HKs and 9 HKLs), 8 HP (7 authentic and 1 pseudo), and 57 RR (21 Type-A, 17 Type-B, 4 Type-C, and 15 pseudo) proteins were identified. The structures, conserved domains, and phylogenetic relationships of these protein-coding genes were analysed in detail. The duplications, evolutionary patterns, and divergence of the TCS genes were investigated. The transcription levels of TCS genes in various tissues, organs, and developmental stages were further analysed to obtain information of the functions of these genes. Cytokinin-related binding elements were found in the putative promoter regions of Type-A BrRR genes. Furthermore, gene expression patterns to adverse environmental stresses (drought and high salinity) and exogenous phytohormones (tZ and ABA) were investigated. Numerous stress-responsive candidate genes were obtained. Our systematic analyses provided insights into the characterization of the TCS genes in Chinese cabbage and basis for further functional studies of such genes. PMID:24585003

  11. Duplicate sfrp1 genes in zebrafish: sfrp1a is dynamically expressed in the developing central nervous system, gut and lateral line.

    PubMed

    Pézeron, Guillaume; Anselme, Isabelle; Laplante, Mary; Ellingsen, Staale; Becker, Thomas S; Rosa, Frédéric M; Charnay, Patrick; Schneider-Maunoury, Sylvie; Mourrain, Philippe; Ghislain, Julien

    2006-10-01

    The secreted frizzled-related proteins (Sfrp) are a family of soluble proteins with diverse biological functions having the capacity to bind Wnt ligands, to modulate Wnt signalling, and to signal directly via the Wnt receptor, Frizzled. In an enhancer trap screen for embryonic expression in zebrafish we identified an sfrp1 gene. Previous studies suggest an important role for sfrp1 in eye development, however, no data have been reported using the zebrafish model. In this paper, we describe duplicate sfrp1 genes in zebrafish and present a detailed analysis of the expression profile of both genes. Whole mount in situ hybridisation analyses of sfrp1a during embryonic and larval development revealed a dynamic expression profile, including: the central nervous system, where sfrp1a was regionally expressed throughout the brain and developing eye; the posterior gut, from the time of endodermal cell condensation; the lateral line, where sfrp1a was expressed in the migrating primordia and interneuromast cells that give rise to the sensory organs. Other sites included the blastoderm, segmenting mesoderm, olfactory placode, developing ear, pronephros and fin-bud. We have also analysed sfrp1b expression during embryonic development. Surprisingly this gene exhibited a divergent expression profile being limited to the yolk syncytium under the elongating tail-bud, which later covered the distal yolk extension, and transiently in the tail-bud mesenchyme. Overall, our studies provide a basis for future analyses of these developmentally important factors using the zebrafish model.

  12. [Intestinal cystic duplication. Case report].

    PubMed

    Herranz Barbero, Ana; Prat Ortells, Jordi; Muñoz Fernández, M Elena; Castañón García-Alix, Montserrat; Figueras Aloy, Josep

    2017-08-01

    Intestinal cystic duplications are rare congenital anomalies, with an estimated incidence of approximately 1:4500 autopsies. The etiopathogenesis is uncertain. These duplications are cystic, tubular or diverticular structures lined with gastrointestinal mucosa. They share a common smooth muscle wall with the gastrointestinal tract but usually their lumens do not communicate with each other. Gastric duplication cysts represent 7-9% of the gastrointestinal tract duplication. They can be diagnosed prenatally by fetal ultrasound; magnetic resonance imaging characterizes the cyst and excludes other malformations. Postnatal ultrasound shows a characteristic double walled cyst. Newborns are usually asymptomatic, although nonspecific gastrointestinal symptoms, intestinal obstruction due to mass effect, volvulus or infection are described. In asymptomatic patients, clinical follow-up and periodic image controls are recommended. Elective surgical resection is the treatment of choice, using minimally invasive technique whenever possible. A case of prenatally suspected intestinal cystic duplication is presented. Sociedad Argentina de Pediatría.

  13. 46 CFR 58.25-60 - Non-duplicated hydraulic rudder actuators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Non-duplicated hydraulic rudder actuators. 58.25-60... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-60 Non-duplicated hydraulic rudder actuators. Non-duplicated hydraulic rudder actuators may be installed in the steering-gear control systems...

  14. 46 CFR 58.25-60 - Non-duplicated hydraulic rudder actuators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Non-duplicated hydraulic rudder actuators. 58.25-60... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-60 Non-duplicated hydraulic rudder actuators. Non-duplicated hydraulic rudder actuators may be installed in the steering-gear control systems...

  15. Endourological treatment of bilateral ureteral stones in bilateral ureteral duplication with right ureterocele

    PubMed Central

    Sen, Volkan; Aydogdu, Ozgu; Yonguc, Tarık; Bozkurt, Ibrahim Halil; Polat, Salih; Basmaci, Ismail

    2015-01-01

    Bilateral collecting system duplication is a very rare abnormality, including the splitting of the ureteric bud. Complete ureteral duplication with two separate openings in the urinary bladder is also extremely rare. To the best of our knowledge, we present the first case of bilateral ureteral stones in bilateral duplicated collecting system. PMID:26279727

  16. Four Pulse Drive System for the Beam Induction Cells for DARHT Axis 2

    SciTech Connect

    Downing, J.; Carlson, R.; Melton, J.; Fockler, J.

    1999-06-28

    The proposed drive system allows for the generation of up to four (4) high-quality radiographic pulses along one line-of-sight, having arbitrary pulse spacing ({approximately}500 ns), using demonstrated technologies. This concept uses a four-pulse drive system to drive both a 16-MeV ensemble of 250-kV, 4-kA induction cells and a four-pulse, 4-MeV injector. The key to this approach lies in the method used to combine four pulses from different generators in a manner that does not compromise the voltage flatness requirement of {+-} 1%. The induction cells use core material for only a single pulse. A simple reverse bias circuit is used to reset the cores between pulses, and the insulator has been redesigned to withstand the reverse reset voltage. This approach can be installed in stages so that the facility can be used for dual axis radiography while implementing the multi-pulsing capability. A dual double-pulse format has been identified which provides a sequence of two pulses along one line-of-sight within a 2-{micro}sec window. The 2-{micro}sec windows can be separated by arbitrary time intervals of 2- to 10-{micro}sec.

  17. Status of the Prototype Pulsed Photonuclear Assessment (PPA) Inspection System

    SciTech Connect

    Prototype Photonuclear Inspection Technoloby - An

    2007-08-01

    Prototype Photonuclear Inspection Technology – An Integrated Systems Approach* James L. Jonesa, Daren R. Normana, Kevin J. Haskella, James W. Sterbentza, Woo Y. Yoona, Scott M. Watsona, James T. Johnsona, John M. Zabriskiea, Calvin E. Mossb, Frank Harmonc a – Idaho National Laboratory, P.O. Box 1625-2802, Idaho Falls, Idaho 83415-2802 b – Los Alamos National Laboratory, P.O. Box 1663, MS B228, Los Alamos, New Mexico, 87585 c – Idaho State University, 1500 Alvin Ricken Dr., Pocatello, Idaho 83201 Active interrogation technologies are being pursued in order to address many of today’s challenging inspection requirements related to both nuclear and non-nuclear material detection. The Idaho National Laboratory, along with the Los Alamos National Laboratory and the Idaho State University’s Idaho Accelerator Center, continue to develop electron accelerator-based, photonuclear inspection technologies for the detection of shielded nuclear material within air-, rail-, and especially, maritime-cargo containers. This paper presents an overview and status of the prototype Pulsed Photonuclear Assessment (PPA) inspection system and its ability to detect shielded nuclear material by focusing on the integration of three major detection system components: delayed neutron measurement, delayed gamma-ray measurements, and a transmission, gray-scale mapping for shield material detection. Areas of future development and advancement within each detection component will be presented. *Supported in part by the Department of Homeland Security under DOE-ID Contract Number DE-AC07-99ID13727. POC: James L. Jones, 208-526-1730

  18. Effects of pulse shape on strongly driven two-level systems

    SciTech Connect

    Conover, C. W. S.

    2011-12-15

    We present an experimental study of the dynamics of a two-level system driven by strong nonresonant electromagnetic pulses as a function of pulse intensity and detuning. We have explored the qualitative and quantitative behavior of the transition probability as a function of pulse area for five different temporal profiles: Lorentzian, Lorentzian squared, hyperbolic secant, hyperbolic secant squared, and Gaussian. The two-level system consists of a fine-structure doublet in sodium Rydberg states coupled by Raman transitions driven through far-off-resonance intermediate states. The pulses are in the microwave regime and have high fidelity and uniform intensity. Experiments show that, despite the similarity in the pulse shapes, the behavior of the population transfer versus intensity depends dramatically on the temporal shape and that the spectral properties and area of the pulse do not adequately describe the response.

  19. Damage assessment of long-range rocket system by electromagnetic pulse weapon

    NASA Astrophysics Data System (ADS)

    Cao, Lingyu; Liu, Guoqing; Li, Jinming

    2017-08-01

    This paper analyzes the damage mechanism and characteristics of electromagnetic pulse weapon, establishes the index system of survivability of long-range rocket launcher system, and uses AHP method to establish the combat effectiveness model of long-range rocket missile system. According to the damage mechanism and characteristics of electromagnetic pulse weapon, the damage effect of the remote rocket system is established by using the exponential method to realize the damage efficiency of the remote rocket system.

  20. Multifunctional pulse generator for high-intensity focused ultrasound system

    NASA Astrophysics Data System (ADS)

    Tamano, Satoshi; Yoshizawa, Shin; Umemura, Shin-Ichiro

    2017-07-01

    High-intensity focused ultrasound (HIFU) can achieve high spatial resolution for the treatment of diseases. A major technical challenge in implementing a HIFU therapeutic system is to generate high-voltage high-current signals for effectively exciting a multichannel HIFU transducer at high efficiencies. In this paper, we present the development of a multifunctional multichannel generator/driver. The generator can produce a long burst as well as an extremely high-voltage short pulse of pseudosinusoidal waves (trigger HIFU) and second-harmonic superimposed waves for HIFU transmission. The transmission timing, waveform, and frequency can be controlled using a field-programmable gate array (FPGA) via a universal serial bus (USB) microcontroller. The hardware is implemented in a compact printed circuit board. The test results of trigger HIFU reveal that the power consumption and the temperature rise of metal-oxide semiconductor field-effect transistors were reduced by 19.9% and 38.2 °C, respectively, from the previous design. The highly flexible performance of the novel generator/driver is demonstrated in the generation of second-harmonic superimposed waves, which is useful for cavitation-enhanced HIFU treatment, although the previous design exhibited difficulty in generating it.

  1. Supervised Learning for Detection of Duplicates in Genomic Sequence Databases.

    PubMed

    Chen, Qingyu; Zobel, Justin; Zhang, Xiuzhen; Verspoor, Karin

    2016-01-01

    First identified as an issue in 1996, duplication in biological databases introduces redundancy and even leads to inconsistency when contradictory information appears. The amount of data makes purely manual de-duplication impractical, and existing automatic systems cannot detect duplicates as precisely as can experts. Supervised learning has the potential to address such problems by building automatic systems that learn from expert curation to detect duplicates precisely and efficiently. While machine learning is a mature approach in other duplicate detection contexts, it has seen only preliminary application in genomic sequence databases. We developed and evaluated a supervised duplicate detection method based on an expert curated dataset of duplicates, containing over one million pairs across five organisms derived from genomic sequence databases. We selected 22 features to represent distinct attributes of the database records, and developed a binary model and a multi-class model. Both models achieve promising performance; under cross-validation, the binary model had over 90% accuracy in each of the five organisms, while the multi-class model maintains high accuracy and is more robust in generalisation. We performed an ablation study to quantify the impact of different sequence record features, finding that features derived from meta-data, sequence identity, and alignment quality impact performance most strongly. The study demonstrates machine learning can be an effective additional tool for de-duplication of genomic sequence databases. All Data are available as described in the supplementary material.

  2. Supervised Learning for Detection of Duplicates in Genomic Sequence Databases

    PubMed Central

    Zobel, Justin; Zhang, Xiuzhen; Verspoor, Karin

    2016-01-01

    Motivation First identified as an issue in 1996, duplication in biological databases introduces redundancy and even leads to inconsistency when contradictory information appears. The amount of data makes purely manual de-duplication impractical, and existing automatic systems cannot detect duplicates as precisely as can experts. Supervised learning has the potential to address such problems by building automatic systems that learn from expert curation to detect duplicates precisely and efficiently. While machine learning is a mature approach in other duplicate detection contexts, it has seen only preliminary application in genomic sequence databases. Results We developed and evaluated a supervised duplicate detection method based on an expert curated dataset of duplicates, containing over one million pairs across five organisms derived from genomic sequence databases. We selected 22 features to represent distinct attributes of the database records, and developed a binary model and a multi-class model. Both models achieve promising performance; under cross-validation, the binary model had over 90% accuracy in each of the five organisms, while the multi-class model maintains high accuracy and is more robust in generalisation. We performed an ablation study to quantify the impact of different sequence record features, finding that features derived from meta-data, sequence identity, and alignment quality impact performance most strongly. The study demonstrates machine learning can be an effective additional tool for de-duplication of genomic sequence databases. All Data are available as described in the supplementary material. PMID:27489953

  3. NIF-type iron-sulfur cluster assembly system is duplicated and distributed in the mitochondria and cytosol of Mastigamoeba balamuthi

    PubMed Central

    Nývltová, Eva; Šuták, Robert; Harant, Karel; Šedinová, Miroslava; Hrdý, Ivan; Pačes, Jan; Vlček, Čestmír; Tachezy, Jan

    2013-01-01

    In most eukaryotes, the mitochondrion is the main organelle for the formation of iron-sulfur (FeS) clusters. This function is mediated through the iron-sulfur cluster assembly machinery, which was inherited from the α-proteobacterial ancestor of mitochondria. In Archamoebae, including pathogenic Entamoeba histolytica and free-living Mastigamoeba balamuthi, the complex iron-sulfur cluster machinery has been replaced by an ε-proteobacterial nitrogen fixation (NIF) system consisting of two components: NifS (cysteine desulfurase) and NifU (scaffold protein). However, the cellular localization of the NIF system and the involvement of mitochondria in archamoebal FeS assembly are controversial. Here, we show that the genes for both NIF components are duplicated within the M. balamuthi genome. One paralog of each protein contains an amino-terminal extension that targets proteins to mitochondria (NifS-M and NifU-M), and the second paralog lacks a targeting signal, thereby reflecting the cytosolic form of the NIF machinery (NifS-C and NifU-C). The dual localization of the NIF system corresponds to the presence of FeS proteins in both cellular compartments, including detectable hydrogenase activity in Mastigamoeba cytosol and mitochondria. In contrast, E. histolytica possesses only single genes encoding NifS and NifU, respectively, and there is no evidence for the presence of the NIF machinery in its reduced mitochondria. Thus, M. balamuthi is unique among eukaryotes in that its FeS cluster formation is mediated through two most likely independent NIF machineries present in two cellular compartments. PMID:23589868

  4. NIF-type iron-sulfur cluster assembly system is duplicated and distributed in the mitochondria and cytosol of Mastigamoeba balamuthi.

    PubMed

    Nývltová, Eva; Šuták, Robert; Harant, Karel; Šedinová, Miroslava; Hrdy, Ivan; Paces, Jan; Vlček, Čestmír; Tachezy, Jan

    2013-04-30

    In most eukaryotes, the mitochondrion is the main organelle for the formation of iron-sulfur (FeS) clusters. This function is mediated through the iron-sulfur cluster assembly machinery, which was inherited from the α-proteobacterial ancestor of mitochondria. In Archamoebae, including pathogenic Entamoeba histolytica and free-living Mastigamoeba balamuthi, the complex iron-sulfur cluster machinery has been replaced by an ε-proteobacterial nitrogen fixation (NIF) system consisting of two components: NifS (cysteine desulfurase) and NifU (scaffold protein). However, the cellular localization of the NIF system and the involvement of mitochondria in archamoebal FeS assembly are controversial. Here, we show that the genes for both NIF components are duplicated within the M. balamuthi genome. One paralog of each protein contains an amino-terminal extension that targets proteins to mitochondria (NifS-M and NifU-M), and the second paralog lacks a targeting signal, thereby reflecting the cytosolic form of the NIF machinery (NifS-C and NifU-C). The dual localization of the NIF system corresponds to the presence of FeS proteins in both cellular compartments, including detectable hydrogenase activity in Mastigamoeba cytosol and mitochondria. In contrast, E. histolytica possesses only single genes encoding NifS and NifU, respectively, and there is no evidence for the presence of the NIF machinery in its reduced mitochondria. Thus, M. balamuthi is unique among eukaryotes in that its FeS cluster formation is mediated through two most likely independent NIF machineries present in two cellular compartments.

  5. Miniature pulsed magnet system for synchrotron x-ray measurements.

    PubMed

    van der Linden, Peter J E M; Mathon, Olivier; Strohm, Cornelius; Sikora, Marcin

    2008-07-01

    We have developed a versatile experimental apparatus for synchrotron x-ray measurements in pulsed high magnetic fields. The apparatus consists of a double cryostat incorporating a liquid nitrogen bath to cool the miniature pulsed coil and an independent helium flow cryostat allowing sample temperatures from 4 up to 250 K. The high duty cycle miniature pulsed coils can generate up to 38 T. During experiments at 30 T a repetition rate of 6 pulsesmin was routinely reached. Using a 4 kJ power supply, the pulse duration was between 500 mus and 1 ms. The setup was used for nuclear forward scattering measurements on 57Fe up to 25 T on the ESRF beamline ID18. In another experiment, x-ray magnetic circular dichroism was measured up to 30 T on the ESRF energy dispersive beamline ID24.

  6. Evolution of Gene Duplication in Plants.

    PubMed

    Panchy, Nicholas; Lehti-Shiu, Melissa; Shiu, Shin-Han

    2016-08-01

    Ancient duplication events and a high rate of retention of extant pairs of duplicate genes have contributed to an abundance of duplicate genes in plant genomes. These duplicates have contributed to the evolution of novel functions, such as the production of floral structures, induction of disease resistance, and adaptation to stress. Additionally, recent whole-genome duplications that have occurred in the lineages of several domesticated crop species, including wheat (Triticum aestivum), cotton (Gossypium hirsutum), and soybean (Glycine max), have contributed to important agronomic traits, such as grain quality, fruit shape, and flowering time. Therefore, understanding the mechanisms and impacts of gene duplication will be important to future studies of plants in general and of agronomically important crops in particular. In this review, we survey the current knowledge about gene duplication, including gene duplication mechanisms, the potential fates of duplicate genes, models explaining duplicate gene retention, the properties that distinguish duplicate from singleton genes, and the evolutionary impact of gene duplication.

  7. Chirped-Pulse Fourier-Transform Microwave/pulsed Uniform Flow Spectrometer: the Low-Temperature Pulsed Uniform Supersonic Flow System

    NASA Astrophysics Data System (ADS)

    Abeysekera, Chamara; Prozument, Kirill; Oldham, James; Joalland, Baptiste; Zack, Lindsay; Park, Barratt; Field, Robert W.; Sims, Ian; Suits, Arthur

    2014-06-01

    Traditional techniques (e.g. REMPI, imaging, etc.) that are used to study reaction dynamics are able to provide a great deal of fundamental information about systems containing atoms and smaller molecules. However, as larger molecules and more complex systems are targeted, it becomes more of a challenge to determine isomer- and vibrational level-specific information and accurate branching ratios. In order to complement existing methods and obtain information about larger systems, a Ka-band (26-40 GHz) chirped-pulse Fourier transform microwave (CP-FTMW) spectrometer has been has been constructed. The system integrates a pulsed uniform supersonic flow (PUSF) source to ensure that experimental conditions, such as temperature and density, are well-known and constant. This PUSF system is based around a high-throughput piezoelectric stack valve, a Laval nozzle, and simple pumping scheme. This system is able to produce cold, uniform flows with densities on the order of 1016 cm-3 that persist for up to 20 cm from the nozzle exit. A description of this system and its characterization will be presented.

  8. Evolution after whole-genome duplication: a network perspective.

    PubMed

    Zhu, Yun; Lin, Zhenguo; Nakhleh, Luay

    2013-11-06

    Gene duplication plays an important role in the evolution of genomes and interactomes. Elucidating how evolution after gene duplication interplays at the sequence and network level is of great interest. In this work, we analyze a data set of gene pairs that arose through whole-genome duplication (WGD) in yeast. All these pairs have the same duplication time, making them ideal for evolutionary investigation. We investigated the interplay between evolution after WGD at the sequence and network levels and correlated these two levels of divergence with gene expression and fitness data. We find that molecular interactions involving WGD genes evolve at rates that are three orders of magnitude slower than the rates of evolution of the corresponding sequences. Furthermore, we find that divergence of WGD pairs correlates strongly with gene expression and fitness data. Because of the role of gene duplication in determining redundancy in biological systems and particularly at the network level, we investigated the role of interaction networks in elucidating the evolutionary fate of duplicated genes. We find that gene neighborhoods in interaction networks provide a mechanism for inferring these fates, and we developed an algorithm for achieving this task. Further epistasis analysis of WGD pairs categorized by their inferred evolutionary fates demonstrated the utility of these techniques. Finally, we find that WGD pairs and other pairs of paralogous genes of small-scale duplication origin share similar properties, giving good support for generalizing our results from WGD pairs to evolution after gene duplication in general.

  9. Thulium-doped fiber chirped-pulse amplification system with 2 GW of peak power.

    PubMed

    Gaida, C; Gebhardt, M; Stutzki, F; Jauregui, C; Limpert, J; Tünnermann, A

    2016-09-01

    Thulium-doped fibers with ultra large mode-field areas offer new opportunities for the power scaling of mid-IR ultrashort-pulse laser sources. Here, we present a laser system delivering a pulse-peak power of 2 GW and a nearly transform-limited pulse duration of 200 fs in combination with 28.7 W of average power. This performance level has been achieved by optimizing the pulse shape, reducing the overlap with atmospheric absorption lines, and incorporating a climate chamber to reduce the humidity of the atmospheric environment.

  10. Computer-controlled pulsed magnetic field gradient NMR system for electrophoretic mobility measurements

    NASA Astrophysics Data System (ADS)

    Saarinen, Timothy R.; Woodward, W. Stephen

    1988-05-01

    A computer-controlled pulsed magnetic field gradient NMR (PFGNMR) system for making electrophoretic mobility and diffusion measurements is described. Emphasis is placed on the design and capabilities of the gradient and electrophoretic pulse generators. Various pulse sequences can be applied by the programmable gradient generator that can produce 0- to 10-A current pulses for 0 to 13 ms and continuous currents from 0 to 50 mA. The pulse areas are reproducible to within approximately 1 ppm. A pair of opposed Helmholtz coils in the probe create linear magnetic field gradients during the current pulses. Electric fields are applied across a U-tube electrophoretic cell by a 550-V constant current generator.

  11. Method and apparatus for providing pulse pile-up correction in charge quantizing radiation detection systems

    DOEpatents

    Britton, Jr., Charles L.; Wintenberg, Alan L.

    1993-01-01

    A radiation detection method and system for continuously correcting the quantization of detected charge during pulse pile-up conditions. Charge pulses from a radiation detector responsive to the energy of detected radiation events are converted to voltage pulses of predetermined shape whose peak amplitudes are proportional to the quantity of charge of each corresponding detected event by means of a charge-sensitive preamplifier. These peak amplitudes are sampled and stored sequentially in accordance with their respective times of occurrence. Based on the stored peak amplitudes and times of occurrence, a correction factor is generated which represents the fraction of a previous pulses influence on a preceding pulse peak amplitude. This correction factor is subtracted from the following pulse amplitude in a summing amplifier whose output then represents the corrected charge quantity measurement.

  12. Development and characterization of a high yield transportable pulsed neutron source with efficient and compact pulsed power system

    NASA Astrophysics Data System (ADS)

    Verma, Rishi; Mishra, Ekansh; Dhang, Prosenjit; Sagar, Karuna; Meena, Manraj; Shyam, Anurag

    2016-09-01

    The results of characterization experiments carried out on a newly developed dense plasma focus device based intense pulsed neutron source with efficient and compact pulsed power system are reported. Its high current sealed pseudospark switch based low inductance capacitor bank with maximum stored energy of ˜10 kJ is segregated into four modules of ˜2.5 kJ each and it cumulatively delivers peak current in the range of 400 kA-600 kA (corresponding to charging voltage range of 14 kV-18 kV) in a quarter time period of ˜2 μs. The neutron yield performance of this device has been optimized by discretely varying deuterium filling gas pressure in the range of 6 mbar-11 mbar at ˜17 kV/550 kA discharge. At ˜7 kJ/8.5 mbar operation, the average neutron yield has been measured to be in the order of ˜4 × 109 neutrons/pulse which is the highest ever reported neutron yield from a plasma focus device with the same stored energy. The average forward to radial anisotropy in neutron yield is found to be ˜2. The entire system is contained on a moveable trolley having dimensions 1.5 m × 1 m × 0.7 m and its operation and control (up to the distance of 25 m) are facilitated through optically isolated handheld remote console. The overall compactness of this system provides minimum proximity to small as well as large samples for irradiation. The major intended application objective of this high neutron yield dense plasma focus device development is to explore the feasibility of active neutron interrogation experiments by utilization of intense pulsed neutron sources.

  13. Development and characterization of a high yield transportable pulsed neutron source with efficient and compact pulsed power system.

    PubMed

    Verma, Rishi; Mishra, Ekansh; Dhang, Prosenjit; Sagar, Karuna; Meena, Manraj; Shyam, Anurag

    2016-09-01

    The results of characterization experiments carried out on a newly developed dense plasma focus device based intense pulsed neutron source with efficient and compact pulsed power system are reported. Its high current sealed pseudospark switch based low inductance capacitor bank with maximum stored energy of ∼10 kJ is segregated into four modules of ∼2.5 kJ each and it cumulatively delivers peak current in the range of 400 kA-600 kA (corresponding to charging voltage range of 14 kV-18 kV) in a quarter time period of ∼2 μs. The neutron yield performance of this device has been optimized by discretely varying deuterium filling gas pressure in the range of 6 mbar-11 mbar at ∼17 kV/550 kA discharge. At ∼7 kJ/8.5 mbar operation, the average neutron yield has been measured to be in the order of ∼4 × 10(9) neutrons/pulse which is the highest ever reported neutron yield from a plasma focus device with the same stored energy. The average forward to radial anisotropy in neutron yield is found to be ∼2. The entire system is contained on a moveable trolley having dimensions 1.5 m × 1 m × 0.7 m and its operation and control (up to the distance of 25 m) are facilitated through optically isolated handheld remote console. The overall compactness of this system provides minimum proximity to small as well as large samples for irradiation. The major intended application objective of this high neutron yield dense plasma focus device development is to explore the feasibility of active neutron interrogation experiments by utilization of intense pulsed neutron sources.

  14. Development and characterization of a high yield transportable pulsed neutron source with efficient and compact pulsed power system

    SciTech Connect

    Verma, Rishi E-mail: rishiv@barc.gov.in; Mishra, Ekansh; Dhang, Prosenjit; Sagar, Karuna; Meena, Manraj; Shyam, Anurag

    2016-09-15

    The results of characterization experiments carried out on a newly developed dense plasma focus device based intense pulsed neutron source with efficient and compact pulsed power system are reported. Its high current sealed pseudospark switch based low inductance capacitor bank with maximum stored energy of ∼10 kJ is segregated into four modules of ∼2.5 kJ each and it cumulatively delivers peak current in the range of 400 kA–600 kA (corresponding to charging voltage range of 14 kV–18 kV) in a quarter time period of ∼2 μs. The neutron yield performance of this device has been optimized by discretely varying deuterium filling gas pressure in the range of 6 mbar–11 mbar at ∼17 kV/550 kA discharge. At ∼7 kJ/8.5 mbar operation, the average neutron yield has been measured to be in the order of ∼4 × 10{sup 9} neutrons/pulse which is the highest ever reported neutron yield from a plasma focus device with the same stored energy. The average forward to radial anisotropy in neutron yield is found to be ∼2. The entire system is contained on a moveable trolley having dimensions 1.5 m × 1 m × 0.7 m and its operation and control (up to the distance of 25 m) are facilitated through optically isolated handheld remote console. The overall compactness of this system provides minimum proximity to small as well as large samples for irradiation. The major intended application objective of this high neutron yield dense plasma focus device development is to explore the feasibility of active neutron interrogation experiments by utilization of intense pulsed neutron sources.

  15. Development of Multi-pulse Compact Toroid Injector System for C-2U

    NASA Astrophysics Data System (ADS)

    Allfrey, I.; Garate, E.; Morehouse, M.; Roche, T.; Gota, H.; Valentine, T.; Waggoner, W.; Putvinski, S.; Cordero, M.; Asai, T.; Matsumoto, T.; Sekiguchi, J.; the TAE Team

    2015-11-01

    The C-2U experiment aims at sustaining a dynamically formed field reversed configuration (FRC) for 5 + ms via injection of 10 +MW of neutral beams. One of the systems currently used to refuel the C-2U plasma is a single pulse compact toroid injector (CTI). The CTI is a magnetized co-axial plasma gun, which generates a spheromak-like plasma that is injected into the core of the advanced beam-driven FRC of C-2U. In order to refuel the recent long-lived plasmas in C-2U, a multi-pulse CTI system, whose modular design allows for expandable burst numbers, is being designed. Details of the pulsed power systems used to energize the single pulse and the upgraded multi-pulse CTI will be discussed. Results of injector performance carried out on a dedicated test stand as well as some refueling data on C-2U will also be presented.

  16. Pasteurization of strawberry puree using a pilot plant pulsed electric fields (PEF) system

    USDA-ARS?s Scientific Manuscript database

    The processing of strawberry puree by pulsed electric fields (PEF) in a pilot plant system has never been evaluated. In addition, a method does not exist to validate the exact number and shape of the pulses applied during PEF processing. Both buffered peptone water (BPW) and fresh strawberry puree (...

  17. Formation of long nanosecond rectangular pulses in the active RF pulse compression system with a compact resonant cavity

    NASA Astrophysics Data System (ADS)

    Artemenko, S. N.; Gorev, S. A.; Igumnov, V. S.; Yushkov, Yu G.

    2017-05-01

    This work presents the results of the study of an active microwave pulse compression system capable of forming the rectangular pulses with duration ∼10-100 ns, while its dimensions are several times smaller than the radiated wave train. Such compression system is based on the compact planar-voluminal resonant cavity constructed in the shape of a meander from waveguide sections and H-plane tees. The resonant cavity sections are parallel and are in the same plane with tees. The energy input element is located in the input end of the first section. The output device designed as an H-plane tee interference switch is connected to the output end of the last section. Each end of remaining sections is connected through a straight arm to an H-tee with a short-circuited quarter-wave second straight arm. The side arm of each tee is connected with the side arm of the tee in the next section, thus coupling the sections. The short-circuited arm provides the “open” mode and transmission of the wave from tee to tee. We determined the expressions for wave amplitudes in the components of the meander resonant cavity made of three sections and analyzed the expressions as the functions of the parameters determining the oscillation range and energy distribution in the resonant cavity. Experiments demonstrated that under certain conditions the compressors with such resonant cavity could generate nearly rectangular pulses with duration equal to the time of wave two-way traveling along the resonant cavity, and with the power compatible with that of the wave in the resonant cavity, and the length of the radiated wave train several-fold exceeding the size of the compressor. At pulse duration equal to 25 ns, the gain coefficient was 13 dB and pulse power was 40 MW. The work demonstrates the possibility to change the geometry of the resonant cavity by rearranging its components without changing the output pulse parameters.

  18. Pulse bursts with a controllable number of pulses from a mode-locked Yb-doped all fiber laser system.

    PubMed

    Li, Xingliang; Zhang, Shumin; Hao, Yanping; Yang, Zhenjun

    2014-03-24

    Pulse bursts with a controllable number of pulses per burst have been produced directly from a mode-locked Yb-doped fiber laser for the first time. Each output burst contained numerous pulses with a high pulse repetition rate of 29.4 MHz. The duration of a single pulse was 680 ps. The pulse burst had a repetition rate of 251.6 kHz. The pulse burst could easily be further amplified to a total pulse burst energy of ~795 nJ, corresponding to a total average power of 200 mW.

  19. Evolution of ancient functions in the vertebrate insulin-like growth factor system uncovered by study of duplicated salmonid fish genomes.

    PubMed

    Macqueen, Daniel J; Garcia de la Serrana, Daniel; Johnston, Ian A

    2013-05-01

    Whole-genome duplication (WGD) was experienced twice by the vertebrate ancestor (2 rounds; 2R), again by the teleost fish ancestor (3R) and most recently in certain teleost lineages (4R). Consequently, vertebrate gene families are often expanded in 3R and 4R genomes. Arguably, many types of "functional divergence" present across 2R gene families will exceed that between 3R/4R paralogs of genes comprising 2R families. Accordingly, 4R offers a form of replication of 2R. Examining whether this concept has implications for molecular evolutionary research, we studied insulin-like growth factor (IGF) binding proteins (IGFBPs), whose six 2R family members carry IGF hormones and regulate interactions between IGFs and IGF1-receptors (IGF1Rs). Using phylogenomic approaches, we resolved the complete IGFBP repertoire of 4R-derived salmonid fishes (19 genes; 13 more than human) and established evolutionary relationships/nomenclature with respect to WGDs. Traits central to IGFBP action were determined for all genes, including atomic interactions in IGFBP-IGF1/IGF2 complexes regulating IGF-IGF1R binding. Using statistical methods, we demonstrate that attributes of these protein interfaces are overwhelming a product of 2R IGFBP family membership, explain 49-68% of variation in IGFBP mRNA concentration in several different tissues, and strongly predict the strength and direction of IGFBP transcriptional regulation under differing nutritional states. The results support a model where vertebrate IGFBP family members evolved divergent structural attributes to provide distinct competition for IGFs with IGF1Rs, predisposing different functions in the regulation of IGF signaling. Evolution of gene expression then acted to ensure the appropriate physiological production of IGFBPs according to their structural specializations, leading to optimal IGF-signaling according to nutritional-status and the endocrine/local mode of action. This study demonstrates that relatively recent gene family

  20. Evolution of Ancient Functions in the Vertebrate Insulin-Like Growth Factor System Uncovered by Study of Duplicated Salmonid Fish Genomes

    PubMed Central

    Macqueen, Daniel J.; Garcia de la serrana, Daniel; Johnston, Ian A.

    2013-01-01

    Whole-genome duplication (WGD) was experienced twice by the vertebrate ancestor (2 rounds; 2R), again by the teleost fish ancestor (3R) and most recently in certain teleost lineages (4R). Consequently, vertebrate gene families are often expanded in 3R and 4R genomes. Arguably, many types of “functional divergence” present across 2R gene families will exceed that between 3R/4R paralogs of genes comprising 2R families. Accordingly, 4R offers a form of replication of 2R. Examining whether this concept has implications for molecular evolutionary research, we studied insulin-like growth factor (IGF) binding proteins (IGFBPs), whose six 2R family members carry IGF hormones and regulate interactions between IGFs and IGF1-receptors (IGF1Rs). Using phylogenomic approaches, we resolved the complete IGFBP repertoire of 4R-derived salmonid fishes (19 genes; 13 more than human) and established evolutionary relationships/nomenclature with respect to WGDs. Traits central to IGFBP action were determined for all genes, including atomic interactions in IGFBP–IGF1/IGF2 complexes regulating IGF–IGF1R binding. Using statistical methods, we demonstrate that attributes of these protein interfaces are overwhelming a product of 2R IGFBP family membership, explain 49–68% of variation in IGFBP mRNA concentration in several different tissues, and strongly predict the strength and direction of IGFBP transcriptional regulation under differing nutritional states. The results support a model where vertebrate IGFBP family members evolved divergent structural attributes to provide distinct competition for IGFs with IGF1Rs, predisposing different functions in the regulation of IGF signaling. Evolution of gene expression then acted to ensure the appropriate physiological production of IGFBPs according to their structural specializations, leading to optimal IGF-signaling according to nutritional-status and the endocrine/local mode of action. This study demonstrates that relatively recent

  1. 46 CFR 58.25-60 - Non-duplicated hydraulic rudder actuators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Non-duplicated hydraulic rudder actuators. 58.25-60... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-60 Non-duplicated hydraulic rudder actuators. Non-duplicated hydraulic rudder actuators may be installed in the steering-gear control...

  2. 46 CFR 58.25-60 - Non-duplicated hydraulic rudder actuators.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Non-duplicated hydraulic rudder actuators. 58.25-60... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-60 Non-duplicated hydraulic rudder actuators. Non-duplicated hydraulic rudder actuators may be installed in the steering-gear control...

  3. 46 CFR 58.25-60 - Non-duplicated hydraulic rudder actuators.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Non-duplicated hydraulic rudder actuators. 58.25-60... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-60 Non-duplicated hydraulic rudder actuators. Non-duplicated hydraulic rudder actuators may be installed in the steering-gear control...

  4. Quadratic System Identification: a statistical framework for the paired-pulse paradigm.

    PubMed

    Arunajadai, Srikesh G

    2010-03-01

    System Identification refers to the problem of identifying a model or description of a system based on a stretch of input and the corresponding output from the system. The paired-pulse paradigm or the conditioning test pulse paradigm is often used in neurophysiology experiments. In this work we provide a statistical framework for the conditioning test pulse paradigm which also serves as a system identification tool for quadratic or second order Volterra systems. A nonparametric spectral domain based methodology is proposed for the quadratic system identification. It is shown that by carrying out the analysis in the spectral domain one needs to perform only a single set of double pulse experiments as opposed to multiple sets of experiments in the time domain. Simulation studies are performed to assess the performance of the methodology and to study the conditions under which the methods are expected to perform well.

  5. Advances on Genome Duplication Distances

    NASA Astrophysics Data System (ADS)

    Gagnon, Yves; Savard, Olivier Tremblay; Bertrand, Denis; El-Mabrouk, Nadia

    Given a phylogenetic tree involving Whole Genome Duplication events, we contribute to the problem of computing the rearrangement distance on a branch of a tree linking a duplication node d to a speciation node or a leaf s. In the case of a genome G at s containing exactly two copies of each gene, the genome halving problem is to find a perfectly duplicated genome D at d minimizing the rearrangement distance with G. We generalize the existing exact linear-time algorithm for genome halving to the case of a genome G with missing gene copies. In the case of a known ancestral duplicated genome D, we develop a greedy approach for computing the distance between G and D that is shown time-efficient and very accurate for both the rearrangement and DCJ distances.

  6. Fast Anomaly Discovery Given Duplicates

    DTIC Science & Technology

    2012-12-01

    skipping the computations for duplicate points in SN(ui) that have ci larger than k, the runtime complexity is enhanced significantly. That is, in...Fast anomaly discovery given duplicates Jay-Yoon Lee, U Kang, Danai Koutra, Christos Faloutsos Dec 2012 CMU-CS-12-146 School of Computer Science...ES) Carnegie Mellon University,School of Computer Science,Pittsburgh,PA,15213 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING

  7. Repeating pulsed magnet system for axion-like particle searches and vacuum birefringence experiments

    NASA Astrophysics Data System (ADS)

    Yamazaki, T.; Inada, T.; Namba, T.; Asai, S.; Kobayashi, T.; Matsuo, A.; Kindo, K.; Nojiri, H.

    2016-10-01

    We have developed a repeating pulsed magnet system which generates magnetic fields of about 10 T in a direction transverse to an incident beam over a length of 0.8 m with a repetition rate of 0.2 Hz. Its repetition rate is by two orders of magnitude higher than usual pulsed magnets. It is composed of four low resistance racetrack coils and a 30 kJ transportable capacitor bank as a power supply. The system aims at axion-like particle searches with a pulsed light source and vacuum birefringence measurements. We report on the details of the system and its performances.

  8. Low-cost laser scanning photoacoustic microscopy system with a pulsed laser diode excitation source

    NASA Astrophysics Data System (ADS)

    Erfanzadeh, Mohsen; Zhu, Quing

    2017-03-01

    We present a low-cost laser scanning photoacoustic microscopy system with a pulsed laser diode as the excitation source. The system utilizes a 905 nm pulsed laser diode with 120 ns pulse width and 1 KHz repetition rate. No averaging is performed in data acquisition, resulting in a short image acquisition time. The maximum field of view is 4.6 mm × 3.7 mm and the lateral resolution is 71 μm. Images of human hairs and mouse ear are presented to demonstrate the feasibility of the system in imaging biological tissue.

  9. High average and peak power few-cycle laser pulses delivered by fiber pumped OPCPA system.

    PubMed

    Rothhardt, J; Hädrich, S; Seise, E; Krebs, M; Tavella, F; Willner, A; Düsterer, S; Schlarb, H; Feldhaus, J; Limpert, J; Rossbach, J; Tünnermann, A

    2010-06-07

    We report on a high power optical parametric amplifier delivering 8 fs pulses with 6 GW peak power. The system is pumped by a fiber amplifier and operated at 96 kHz repetition rate. The average output power is as high as 6.7 W, which is the highest average power few-cycle pulse laser reported so far. When stabilizing the seed oscillator, the system delivered carrier-envelop phase stable laser pulses. Furthermore, high harmonic generation up to the 33(th) order (21.8 nm) is demonstrated in a Krypton gas jet. In addition, the scalability of the presented laser system is discussed.

  10. Design of the coolant system for the Large Coil Test Facility pulse coils

    SciTech Connect

    Bridgman, C.; Ryan, T.L.

    1983-01-01

    The pulse coils will be a part of the Large Coil Test Facility in Oak Ridge, Tennessee, which is designed to test six large tokamak-type superconducting coils. The pulse coil set consists of two resistive coaxial solenoid coils, mounted so that their magnetic axis is perpendicular to the toroidal field lines of the test coil. The pulse coils provide transient vertical fields at test coil locations to simulate the pulsed vertical fields present in tokamak devices. The pulse coils are designed to be pulsed for 30 s every 150 s, which results in a Joule heating of 116 kW per coil. In order to provide this capability, the pulse coil coolant system is required to deliver 6.3 L/s (100 gpm) of subcooled liquid nitrogen at 10-atm absolute pressure. The coolant system can also cool down each pulse coil from room temperature to liquid nitrogen temperature. This paper provides details of the pumping and heat exchange equipment designed for the coolant system and of the associated instrumentation and controls.

  11. KAPTURE-2. A picosecond sampling system for individual THz pulses with high repetition rate

    NASA Astrophysics Data System (ADS)

    Müller, A.-S.

    2017-01-01

    This paper presents a novel data acquisition system for continuous sampling of ultra-short pulses generated by terahertz (THz) detectors. Karlsruhe Pulse Taking Ultra-fast Readout Electronics (KAPTURE) is able to digitize pulse shapes with a sampling time down to 3 ps and pulse repetition rates up to 500 MHz. KAPTURE has been integrated as a permanent diagnostic device at ANKA and is used for investigating the emitted coherent synchrotron radiation in the THz range. A second version of KAPTURE has been developed to improve the performance and flexibility. The new version offers a better sampling accuracy for a pulse repetition rate up to 2 GHz. The higher data rate produced by the sampling system is processed in real-time by a heterogeneous FPGA and GPU architecture operating up to 6.5 GB/s continuously. Results in accelerator physics will be reported and the new design of KAPTURE be discussed.

  12. Nonequilibrium dynamics of a system with two kinds of fermions after a pulse

    NASA Astrophysics Data System (ADS)

    Zvyagin, A. A.

    2017-02-01

    The nonequilibrium evolution of the system of two kinds of fermions under the action of a pulse of the external field has been studied. The number of fermions of each kind oscillates (with beats and decaying) as a function of the duration of the pulse about the value determined by the magnitude of the pulse, and as a function of the magnitude of the pulse. For low-dimensional systems those oscillations can serve as a non-zero-temperature manifestation of dynamical quantum phase transitions. The response of a Fermi gas or liquid in a tilted magnetic field, an edge state of a topological insulator, a quantum wire with spin-orbit coupling, and a dimerized spin-1/2 chain to the pulse can manifest such dynamical oscillations, which can be observed in experiments.

  13. High intensity heat-pulse source operates without cooling system

    NASA Technical Reports Server (NTRS)

    Russell, L. D.

    1970-01-01

    Tungsten-iodine quartz lamp with on-off control is mounted at focus of ellipsoidal reflector and shutter is mounted at conjugate focus. Flux sensor monitors lamp and actuates shutter which emits a heat pulse when the radiant flux builds up to requisite level.

  14. Ultrashort pulse laser microsurgery system with plasma luminescence feedback control

    SciTech Connect

    Kim, B.M.; Feit, M.D.; Rubenchik, A.M.; Gold, D.M.; Darrow, C.B.; Da Silva, L.B.

    1997-11-10

    Plasma luminescence spectroscopy was used for precise ablation of bone tissue during ultrashort pulse laser (USPL) micro-spinal surgery. Strong contrast of the luminescence spectra between bone marrow and spinal cord provided the real time feedback control so that only bone tissue can be selectively ablated while preserving the spinal cord.

  15. Energy consumption of electrooxidation systems with boron-doped diamond electrodes in the pulse current mode

    NASA Astrophysics Data System (ADS)

    Wei, Jun-jun; Gao, Xu-hui; Hei, Li-fu; Askari, Jawaid; Li, Cheng-ming

    2013-01-01

    A pulse current technique was conducted in a boron-doped diamond (BDD) anode system for electrochemical wastewater treatment. Due to the strong generation and weak absorption of hydroxyl radicals on the diamond surface, the BDD electrode possesses a powerful capability of electrochemical oxidation of organic compounds, especially in the pulse current mode. The influences of pulse current parameters such as current density, pulse duty cycle, and frequency were investigated in terms of chemical oxygen demand (COD) removal, average current efficiency, and specific energy consumption. The results demonstrated that the relatively high COD removal and low specific energy consumption were obtained simultaneously only if the current density or pulse duty cycle was adjusted to a reasonable value. Increasing the frequency slightly enhanced the COD removal and average current efficiency. A pulse-BDD anode system showed a stronger energy saving ability than a constant-BDD anode system when the electrochemical oxidation of phenol of the two systems was compared. The results prove that the pulse current technique is more cost-effective and more suitable for a BDD anode system for real wastewater treatment. A kinetic analysis was presented to explain the above results.

  16. A nonlinearity-tolerant frequency domain root M-shaped pulse for coherent optical communication systems.

    PubMed

    Xu, Xian; Zhuge, Qunbi; Châtelain, Benoît; Morsy-Osman, Mohamed; Chagnon, Mathieu; Qiu, Meng; Plant, David V

    2013-12-30

    A new intersymbol interference (ISI)-free nonlinearity-tolerant frequency domain root M-shaped pulse (RMP) is derived for dispersion unmanaged coherent optical transmission systems. Beginning with the relationship between pulse shaping and intra-channel nonlinearity effects, we derive closed-form expressions for the proposed pulse. Experimental demonstrations reveal that by employing the proposed pulse at a roll-off factor of 1, the maximum transmission reach of a single-channel 56 Gb/s polarization-division-multiplexed quadrature phase-shift keying (PDM-QPSK) system can be extended by 33% and 17%, when compared to systems using a root raised cosine (RRC) pulse and a root optimized pulse (ROP), respectively. For a single-channel 128 Gb/s polarization-division-multiplexed 16-quadrature amplitude modulation (PDM-16QAM) system, the reach can be extended by 44% and 18%, respectively. Reach increases of 30% and 13% are also observed for a dense wavelength-division multiplexing (DWDM) 504 Gb/s PDM-QPSK transmission system. The tolerance to narrow filtering effect for the three pulses is experimentally studied as well.

  17. Ideal photon number amplifier and duplicator

    NASA Technical Reports Server (NTRS)

    Dariano, G. M.

    1992-01-01

    The photon number-amplification and number-duplication mechanism are analyzed in the ideal case. The search for unitary evolutions leads to consider also a number-deamplification mechanism, the symmetry between amplification and deamplification being broken by the integer-value nature of the number operator. Both transformations, amplification and duplication, need an auxiliary field which, in the case of amplification, turns out to be amplified in the inverse way. Input-output energy conservation is accounted for using a classical pump or through frequency-conversion of the fields. Ignoring one of the fields is equivalent to considering the amplifier as an open system involving entropy production. The Hamiltonians of the ideal devices are given and compared with those of realistic systems.

  18. A system for measuring the pulse height distribution of ultrafast photomultipliers

    NASA Technical Reports Server (NTRS)

    Abshire, J. B.

    1977-01-01

    A system for measuring the pulse height distribution of gigahertz bandwidth photomultipliers was developed. This system uses a sampling oscilloscope as a sample-hold circuit and has a bandwidth of 12 gigahertz. Test results are given for a static crossed-filed photomultiplier tested with a demonstration system. Calculations on system amplitude resolution capabilities are included for currently available system components.

  19. PULSE SORTER

    DOEpatents

    Wade, E.J.

    1958-07-29

    An apparatus is described for counting and recording the number of electrical pulses occurring in each of a timed sequence of groups of pulses. The particular feature of the invention resides in a novel timing circuit of the univibrator type which provides very accurately timed pulses for opening each of a series of coincidence channels in sequence. The univibrator is shown incorporated in a pulse analyzing system wherein a series of pulse counting channels are periodically opened in order, one at a time, for a predetermtned open time interval, so that only one channel will be open at the time of occurrence of any of the electrical pulses to be sorted.

  20. Effect of pulse chirp parameter on the soliton high-speed transmission systems

    NASA Astrophysics Data System (ADS)

    Ladanyi, L.; Scholtz, L.; Solanska, M.; Mullerova, J.

    2016-12-01

    The word soliton refers to a special kind of wave packets that can propagate undistorted over long distances. As a source for generating soliton pulses in 1990 erbium doped lasers were used. Soliton transmission systems have been the subject of interest for years. It is known that interaction and the balance between the dispersion and nonlinear effects in optical fibers can lead to a special pulse behavior. Soliton pulses can propagate without any changes of the amplitude and the shape via long transmission systems. Due to this advantage they are of interest in long haul communication systems. Here we describe how the random change of input pulse chirp in optical fibers can affect the soliton propagation and interaction between two or more solitons. We have focused on describing some numerical approaches to solve the coupled nonlinear Schrödinger equations, which are useful by solving this kind of problem. Most of laser sources can be approximated by Gaussian distribution or in special cases the second hyperbolic pulses are generated to produce a soliton shaped pulse. The effect of pulse chirp can generate new frequencies due to the frequency chirp. In high bitratetransmission systems this chirp is very important to reduce, because of this new frequency can influence the neighbor channels and lead to BER increasing.

  1. The Next Linear Collider Test Accelerator's RF Pulse Compression and Transmission Systems

    SciTech Connect

    Tantawi, Sami

    1999-02-24

    The overmoded rf transmission and pulsed power compression system for SLAC's Next Linear Collider (NLC) program requires a high degree of transmission efficiency and mode purity to be economically feasible. To this end, a number of new, high power components and systems have been developed at X-band, which transmit rf power in the low loss, circular TE01 mode with negligible mode conversion. In addition, a highly efficient SLED-II* pulse compressor has been developed and successfully tested at high power. The system produced a 200 MW, 250 ns wide pulse with a near-perfect flat-top. In this paper we describe the design and test results of the high power pulse compression system using SLED-II.

  2. Can pulsed xenon ultraviolet light systems disinfect aerobic bacteria in the absence of manual disinfection?

    PubMed

    Jinadatha, Chetan; Villamaria, Frank C; Ganachari-Mallappa, Nagaraja; Brown, Donna S; Liao, I-Chia; Stock, Eileen M; Copeland, Laurel A; Zeber, John E

    2015-04-01

    Whereas pulsed xenon-based ultraviolet light no-touch disinfection systems are being increasingly used for room disinfection after patient discharge with manual cleaning, their effectiveness in the absence of manual disinfection has not been previously evaluated. Our study indicates that pulsed xenon-based ultraviolet light systems effectively reduce aerobic bacteria in the absence of manual disinfection. These data are important for hospitals planning to adopt this technology as adjunct to routine manual disinfection. Published by Elsevier Inc.

  3. Environmental and industrial applications of pulsed power systems

    SciTech Connect

    Neau, E.L.

    1993-10-01

    The technology base formed by the development of high peak power simulators, laser drivers, free electron lasers (FEL`s), and Inertial Confinement Fusion (ICF) drivers from the early 60`s through the late 80`s is being extended to high average power short-pulse machines with the capabilities of performing new roles in environmental cleanup applications and in supporting new types of industrial manufacturing processes. Some of these processes will require very high average beam power levels of hundreds of kilowatts to perhaps megawatts. In this paper we briefly discuss new technology capabilities and then concentrate on specific application areas that may benefit from the high specific energies and high average powers attainable with short-pulse machines.

  4. Electromagnetic pulse research on electric power systems: Program summary and recommendations. Power Systems Technology Program

    SciTech Connect

    Barnes, P.R.; McConnell, B.W.; Van Dyke, J.W.; Tesche, F.M.; Vance, E.F.

    1993-01-01

    A single nuclear detonation several hundred kilometers above the central United States will subject much of the nation to a high-altitude electromagnetic pulse (BENT). This pulse consists of an intense steep-front, short-duration transient electromagnetic field, followed by a geomagnetic disturbance with tens of seconds duration. This latter environment is referred to as the magnetohydrodynamic electromagnetic pulse (NMENT). Both the early-time transient and the geomagnetic disturbance could impact the operation of the nation`s power systems. Since 1983, the US Department of Energy has been actively pursuing a research program to assess the potential impacts of one or more BENT events on the nation`s electric energy supply. This report summarizes the results of that program and provides recommendations for enhancing power system reliability under HENT conditions. A nominal HENP environment suitable for assessing geographically large systems was developed during the program and is briefly described in this report. This environment was used to provide a realistic indication of BEMP impacts on electric power systems. It was found that a single high-altitude burst, which could significantly disturb the geomagnetic field, may cause the interconnected power network to break up into utility islands with massive power failures in some areas. However, permanent damage would be isolated, and restoration should be possible within a few hours. Multiple bursts would likely increase the blackout areas, component failures, and restoration time. However, a long-term blackout of many months is unlikely because major power system components, such as transformers, are not likely to be damaged by the nominal HEND environment. Moreover, power system reliability, under both HENT and normal operating conditions, can be enhanced by simple, and often low cost, modifications to current utility practices.

  5. Optimum transformer design for a pulsed power system

    SciTech Connect

    Broverman, A.Y.

    1987-11-01

    Electromagnetic forces resulting from peak pulsed current require special design consideration to prevent failure of the coils of the transformer. Procedures for interleaving transformer windings to reduce both electromagnetic short-circuit forces and reactive voltage drop while reducing procurement costs are described. The basics of transformer design principles and cost trade-offs are included to enhance understanding of the interleaving procedures. 3 refs., 3 figs.

  6. Multiple-Frequency Ultrasonic Pulse-Echo Display System.

    DTIC Science & Technology

    1982-09-28

    provides oscilloscope sync . The DELAY pulse’s rising edge coincides with the first waveform sample; the falling edge comes at a time approximately...TRIGGER output as sync for oscilloscope, monitor DELAY output. Set time/div. of scope to 0.5 us/dIv. Using an insulated adjustment tool, set the Venier...must be adjusted out sap - INPUTS rately from the sample hold. This is most easily done by using the Input Voltage Range ...... ... y=0 min gain

  7. Advances in pulsed-power-driven radiography system design.

    SciTech Connect

    Portillo, Salvador; Hinshelwood, David D.; Rovang, Dean Curtis; Cordova, Steve Ray; Oliver, Bryan Velten; Weber, Bruce V.; Welch, Dale Robert; Shelton, Bradley Allen; Sceiford, Matthew E.; Cooperstein, Gerald; Gignac, Raymond Edward; Puetz, Elizabeth A.; Rose, David Vincent; Barker, Dennis L.; Van De Valde, David M.; Droemer, Darryl W.; Wilkins, Frank Lee; Molina, Isidro; Jaramillo, Deanna M.; Swanekamp, Stephen Brian; Commisso, Robert J.; Bailey, Vernon Leslie; Maenchen, John Eric; Johnson, David Lee; Griffin, Fawn A.; Hahn, Kelly Denise; Smith, Ian

    2004-07-01

    Flash x-ray radiography has undergone a transformation in recent years with the resurgence of interest in compact, high intensity pulsed-power-driven electron beam sources. The radiographic requirements and the choice of a consistent x-ray source determine the accelerator parameters, which can be met by demonstrated Induction Voltage Adder technologies. This paper reviews the state of the art and the recent advances which have improved performance by over an order of magnitude in beam brightness and radiographic utility.

  8. Ultrashort-pulse laser machining system employing a parametric amplifier

    DOEpatents

    Perry, Michael D.

    2004-04-27

    A method and apparatus are provided for increasing the energy of chirped laser pulses to an output in the range 0.001 to over 10 millijoules at a repetition rate 0.010 to 100 kHz by using a two stage optical parametric amplifier utilizing a bulk nonlinear crystal wherein the pump and signal beam size can be independently adjusted in each stage.

  9. Scaling and Systems Considerations in Pulsed Inductive Thrusters

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.

    2007-01-01

    Performance scaling in pulsed inductive thrusters is discussed in the context of previous experimental studies and modeling results. Two processes, propellant ionization and acceleration, are interconnected where overall thruster performance and operation are concerned, but they are separated here to gain physical insight into each process and arrive at quantitative criteria that should be met to address or mitigate inherent inductive thruster difficulties. The effects of preionization in lowering the discharge energy requirements relative to a case where no preionization is employed, and in influencing the location of the initial current sheet, are described. The relevant performance scaling parameters for the acceleration stage are reviewed, emphasizing their physical importance and the numerical values required for efficient acceleration. The scaling parameters are then related to the design of the pulsed power train providing current to the acceleration stage. The impact of various choices in pulsed power train and circuit topology selection are reviewed, paying special attention to how these choices mitigate or exacerbate switching, lifetime, and power consumption issues.

  10. Spatiotemporal noise characterization for chirped-pulse amplification systems

    PubMed Central

    Ma, Jingui; Yuan, Peng; Wang, Jing; Wang, Yongzhi; Xie, Guoqiang; Zhu, Heyuan; Qian, Liejia

    2015-01-01

    Optical noise, the core of the pulse-contrast challenge for ultra-high peak power femtosecond lasers, exhibits spatiotemporal (ST) coupling induced by angular dispersion. Full characterization of such ST noise requires two-dimensional measurements in the ST domain. Thus far, all noise measurements have been made only in the temporal domain. Here we report the experimental characterization of the ST noise, which is made feasible by extending cross-correlation from the temporal domain to the ST domain. We experimentally demonstrate that the ST noise originates from the optical surface imperfections in the pulse stretcher/compressor and exhibits a linear ST coupling in the far-field plane. The contrast on the far-field axis, underestimated in the conventional measurements, is further improved by avoiding the far-field optics in the stretcher. These results enhance our understanding of the pulse contrast with respect to its ST-coupling nature and pave the way toward the design of high-contrast ultra-high peak power lasers. PMID:25648187

  11. Ultrasound generation through a fiber optic delivery system using pulsed laser energy

    SciTech Connect

    Carlson, N.M.; Johnson, J.A.

    1990-01-01

    Short duration laser pulses can generate high frequency, broadband ultrasound in a material without contacting the surface. For these noncontacting techniques to be useful on the shop floor, in remote applications, and in harsh environments, a dependable delivery system must be developed. Fiber optic techniques have been used to deliver either moderate laser energy for a large number of pulses or a large laser energy for a few pulses for the purpose of generating acoustic waves. However, transmitting high energy pulses continuously through a fiber is required for practical sensing systems. Fiber optics systems are currently used for a long duration pulses (of the order of milliseconds) in laser welding applications; e.g. a welding systems developed for manufacture of headlamps uses a fiber optic delivery system. The key to the success of this welding systems is the coupling technique used to deliver laser power to the fiber. Because the pulse duration is on the order of several milliseconds, the power density in the fiber is several orders of magnitude below the power densities required for ultrasonic applications. 17 refs., 2 figs.

  12. Numerical and behavioral effects within a pulse-driven system: consequences for shared prey.

    PubMed

    Schmidt, Kenneth A; Ostfeld, Richard S

    2008-03-01

    Some of the clearest examples of the ramifying effects of resource pulses exist in deciduous forests dominated by mast-producing trees, such as oaks, beech, and hornbeam. Seed production in these forests represents only the first of several pulsed events. Secondary pulses emerge as mast-consuming small rodents numerically respond to seed production and tertiary pulses emerge as generalist predators numerically respond to rodents. Raptors may also respond behaviorally (i.e., diet shifts) to subsequent crashes in small rodents following the crash phase in seed production. In oak-dominated forest in the Hudson Valley, New York, these various pulse and crash phases act synergistically, although not simultaneously, to influence thrush population dynamics through predation on nests, juveniles, and adults. As a consequence, factors limiting population growth rate and their age-specific action vary as a function of past acorn production. We highlight these interactions based on our eight-year study of thrush demography, acorn production, and small mammal abundance coupled with information on regional adult thrush population trends from the Breeding Bird Survey. We use these data sets to demonstrate the sequence of primary to tertiary pulses and how they influence breeding thrush populations. To extend our discussion beyond masting phenomena in the eastern United States, we briefly review the literature of alternative avian prey within pulsed systems to show (1) numerical and behavioral responses by generalist predators are ubiquitous in pulsed systems, and this contributes to (2) variability in reproduction and survivorship of avian prey linked to the underlying dynamics of the pulse. We conclude by exploring the broad consequences of cascading resource pulses for alternative prey based upon the indirect interaction of apparent competition among shared prey and the nature of temporal variability on populations.

  13. Duplication of coding segments in genetic programming

    SciTech Connect

    Haynes, T.

    1996-12-31

    Research into the utility of non-coding segments, or introns, in genetic-based encodings has shown that they expedite the evolution of solutions in domains by protecting building blocks against destructive crossover. We consider a genetic programming system where non-coding segments can be removed, and the resultant chromosomes returned into the population. This parsimonious repair leads to premature convergence, since as we remove the naturally occurring non-coding segments, we strip away their protective backup feature. We then duplicate the coding segments in the repaired chromosomes, and place the modified chromosomes into the population. The duplication method significantly improves the learning rate in the domain we have considered. We also show that this method can be applied to other domains.

  14. Design description of the Large Coil Test Facility pulse-coil support and transport system

    SciTech Connect

    Queen, C.C.

    1981-01-01

    In order to simulate the transient fields which would be imposed on superconducting toroidal field coils in an operating tokamak reactor, the Large Coil Test Facility (LCTF) test stand includes a set of pulse coils. This set of pulse coils is designed to be moved from one test location to another within the LCTF vacuum vessel while the vessel is operating under vacuum and the test stand and test coils are at an operating temperature of 4.2K. This operating environment and the extremely high magnetic loads have necessitated some unique design features for the pulse coil support and transport system. The support structure for the pulse coil must react high overturning moments and axial loads induced on the pulse coil by the interaction of the pulse field with the field generated by the large test coils. These loads are reacted into the test stand support structure or spider frame by an arrangement of six pedestals and a support beam. In order to move the pulse coil set from one test location to another, the support beam containing the pulse coils must be driven across rollers mounted on the pedestals, then clamped securely to react the loads. Because these operations must be performed in a vacuum environment at cryogenic tmperature, special consideration was given to component design.

  15. Congenital duplication of the larynx.

    PubMed

    Simpson, A I; Khanna, A; Stanton, A

    2014-06-01

    The larynx is an intricate structure serving three important functions in humans: it protects the lower respiratory airway, facilitates respiration and helps produce sound through a key role in phonation. We report the first published finding of congenital duplication of the larynx in a patient with previously cleared squamous cell carcinoma of the neck and a new diagnosis of squamous cell carcinoma of the lung. We describe the incidental finding of duplication of the larynx in a 62-year-old man with previously completely cleared squamous cell carcinoma of the neck, who presented with worsening dyspnoea. We also provide a brief overview of other published cases in which duplication of the vocal folds and epiglottis has been reported. Our patient experienced no symptoms related to this incidental finding of congenital duplication of the larynx. The first case of congenital duplication of the larynx is currently of academic interest only; however, the possible association with squamous cell carcinoma is postulated to raise awareness in clinicians who may observe further cases in the future.

  16. Autonomic Nervous System Responses to Concussion: Arterial Pulse Contour Analysis

    PubMed Central

    La Fountaine, Michael F.; Toda, Michita; Testa, Anthony J.; Hill-Lombardi, Vicci

    2016-01-01

    The arterial pulse wave (APW) has a distinct morphology whose contours reflect dynamics in cardiac function and peripheral vascular tone as a result of sympathetic nervous system (SNS) control. With a transition from rest to increased metabolic demand, the expected augmentation of SNS outflow will not only affect arterial blood pressure and heart rate but it will also induce changes to the contours of the APW. Following a sports concussion, a transient state cardiovascular autonomic dysfunction is present. How this state affects the APW has yet to be described. A prospective, parallel-group study on cardiovascular autonomic control (i.e., digital electrocardiogram and continuous beat-to-beat blood pressure) was performed in the seated upright position in 10 athletes with concussion and 7 non-injured control athletes. Changes in APW were compared at rest and during the first 60 s (F60) of an isometric handgrip test (IHGT) in concussed athletes and non-injured controls within 48 h and 1 week of injury. The concussion group was further separated by the length of time until they were permitted to return to play (RTP > 1week; RTP ≤ 1week). SysSlope, an indirect measurement of stroke volume, was significantly lower in the concussion group at rest and during F60 at 48 h and 1week; a paradoxical decline in SysSlope occurred at each visit during the transition from rest to IHGT F60. The RTP > 1week group had lower SysSlope (405 ± 200; 420 ± 88; 454 ± 236 mmHg/s, respectively) at rest 48 h compared to the RTP ≤ 1week and controls. Similarly at 48 h rest, several measurements of arterial stiffness were abnormal in RTP > 1week compared to RTP ≤ 1week and controls: peak-to-notch latency (0.12 ± 0.04; 0.16 ± 0.02; 0.17 ± 0.05, respectively), notch relative amplitude (0.70 ± 0.03; 0.71 ± 0.04; 0.66 ± 0.14, respectively), and stiffness index (6.4 ± 0.2; 5.7 ± 0.4; 5.8 ± 0

  17. Compensation of high-order phase distortions in chirped-pulse amplification system

    NASA Astrophysics Data System (ADS)

    Zhou, Bing; Jiang, Yong-Liang; Leng, Yu-xin; Chen, Xiao-Wei; Li, Ru-Xin; Xu, Zhi-Zhan

    2007-01-01

    Chirped-pulse amplification (CPA) technique has been widely used to generate ultra-intense femto-second pulses. In this scheme the seed pulses from an oscillator are stretched before amplification. The stretched pulses can support more energy extraction and effectively decrease the nonlinear effects in the gain media. The subsequent amplification in a CPA chain will result in a broadening of the output compressed pulses in temporal domain due to the gain narrowing and uncompensated phase distortions. In our experiment, using spectral modulation and phase pre-compensation system (Acoustic-Optics Programmable Dispersive Filter) between the oscillator and the stretcher, the effects of gain narrowing and high-order dispersions on the pulse duration in kHz chirped-pulse amplification system have been pre-compensated, and the spectral FWHM is expanded from 30nm to 50nm. The effects of GDD, TOD and FOD were investigated by scanning the four dispersion parameters respectively. By pre-compensating the high-order phase distortions with the phase measured by SPIDER, we successfully optimize the output duration from 51fs to 30fs, which is 1.07 times Fourier-transform-limitation.

  18. A three-pulse model of d. c. side harmonic flow in HVDC systems

    SciTech Connect

    Shore, N.L.; Andersson, G.; Canelhas, A.P.; Asplund, G.

    1989-07-01

    A new model for analysis of d.c. side harmonics in HVDC systems is proposed. The model includes the stray capacitances of converter transformers and bushings and represents the 12-pulse converter as four three-pulse harmonic voltage sources. The appearance of ground mode triplen harmonics of troublesome magnitude in pole and electrode lines, as noted in recent site measurements, is explained, as is the increase in magnitude of the characteristic 12-pulse harmonics. The consequences for d.c. filter design and the specification of telephone interference criteria are also discussed.

  19. [The design of all solid-state tunable pulsed Ti:sapphire laser system].

    PubMed

    Chen, Zhe; Ku, Geng; Wan, Junchao; Wang, Wei; Zhou, Chuanqing

    2013-05-01

    This paper presented a design of broadly all solid-state tunable pulsed Ti:sapphire laser with high power and stable performance. The laser was pumped by custom-made Nd:YAG laser which had water cooling system and amplified by two stage amplifier. The method accomplished tunable output of all solid-state tunable pulsed Ti:sapphire laser by modifying the reflection angle of the back mirror. We investigated the relationship between the power of the pumping laser and the all solid-state tunable pulsed Ti: sapphire laser by changing the power of the pumping source.

  20. Amplification of sub-nanosecond pulse in THL-100 laser system

    NASA Astrophysics Data System (ADS)

    Losev, V. F.; Alekseev, S. V.; Ivanov, M. V.; Ivanov, N. G.; Mesyats, G. A.; Mikheev, L. D.; Panchenko, Yu. N.; Ratakhin, N. A.; Yastremsky, A. G.

    2017-01-01

    The results of the formation and amplification of positive chirped 0.1 ns laser pulse at a central wavelength of 470 nm in the laser system THL-100 are presented. It is shown that a front-end allows forming a radiation pulse with a Gaussian intensity profile and the energy up to 7 mJ. At amplification in XeF(C-A) amplifier of the pulse with 2-5 mJ energy a saturated mode is realized and 3.2 J output laser beam energy is reached.

  1. A unique control system simulator for the evaluation of pulsed plasma thrusters

    NASA Technical Reports Server (NTRS)

    Dahlgren, J. B.

    1973-01-01

    Because of the low thrust characteristics of solid-propellant pulsed plasma thrusters and their operational requirement to operate in a vacuum environment, unique and sensitive test techniques are required. A technique evolved for testing and evaluating pulsed plasma thrusters in an open- or closed-loop system mode employs a unique air bearing platform as a single-axis simulator on which the thruster is mounted. The simulator described was developed to evaluate pulsed plasma thrusters in the low micropound range; however, the simulator can be extended to cover the operational range of currently developed millipound thrusters.

  2. Duplication. Units of Instruction. Office Duplication Practices. Teacher's Guide.

    ERIC Educational Resources Information Center

    Powell, Theressa

    This teacher's guide is designed for use in helping secondary and postsecondary students in office occupations education programs to become familiar with duplication procedures and machines. Addressed in the individual units of the guide are the following topics: measurement, paper characteristics and classifications, copy preparation for pasteup…

  3. Characterization of liquid scintillation detector (BC-501A) and digital pulse shape discrimination (DPSD) system

    SciTech Connect

    Lombigit, L. Yussup, N. Ibrahim, Maslina Mohd; Rahman, Nur Aira Abd; Rawi, M. Z. M.

    2015-04-29

    A digital n/γ pulse shape discrimination (PSD) system is currently under development at Instrumentation and Automation Centre, Malaysian Nuclear Agency. This system aims at simultaneous detection of fast neutron and gamma ray in mixed radiations environment. This work reports the system characterization performed on the liquid scintillation detector (BC-501A) and digital pulse shape discrimination (DPSD) system. The characterization involves measurement of electron light output from the BC-501A detector and energy channels calibration of the pulse height spectra acquired with DPSD system using set of photon reference sources. The main goal of this experiment is to calibrate the ADC channel of our DPSD system, characterized the BC-501 detector and find the position of Compton edge which later could be used as threshold for the n/γ PSD experiment. The detector resolution however is worse as compared to other published data but it is expected as our detector has a smaller active volume.

  4. A non-contact pulse automatic positioning measurement system for traditional Chinese medicine.

    PubMed

    Chen, Ying-Yun; Chang, Rong-Seng; Jwo, Ko-Wen; Hsu, Chung-Chi; Tsao, Chu-Pang

    2015-04-27

    This study is to construct a non-contact pulse automatic positioning measurement system for Traditional Chinese Medicine (TCM) using optical triangulation measurements. The system consists of a linear laser, a CMOS image sensor and image analysis software. The linear laser is projected on the pulse beat location on the wrists; the CMOS image sensor records the process and the software analyzes the images. The program mainly uses the optical centroid and fast Fourier transform (FFT) principles to calculate centroid changes (pulse amplitude changes) from the images taken by the CMOS image sensor. It returns the positions of cun, guan and chi pulses automatically in terms of the amplitudes and the signals are then transformed from the time domain (time-amplitude) into the frequency domain (frequency-amplitude) via FFT to obtain the waveforms and frequencies of the cun, guan and chi pulses. It successfully extracts the data from the TCM pulse reading and can be a medical aid system for TCM. Combining the advantages of optical measurement and computer automation, this system provides a non-contact, easy to operate, fast in detection and low-cost equipment design.

  5. A Non-Contact Pulse Automatic Positioning Measurement System for Traditional Chinese Medicine

    PubMed Central

    Chen, Ying-Yun; Chang, Rong-Seng; Jwo, Ko-Wen; Hsu, Chung-Chi; Tsao, Chu-Pang

    2015-01-01

    This study is to construct a non-contact pulse automatic positioning measurement system for Traditional Chinese Medicine (TCM) using optical triangulation measurements. The system consists of a linear laser, a CMOS image sensor and image analysis software. The linear laser is projected on the pulse beat location on the wrists; the CMOS image sensor records the process and the software analyzes the images. The program mainly uses the optical centroid and fast Fourier transform (FFT) principles to calculate centroid changes (pulse amplitude changes) from the images taken by the CMOS image sensor. It returns the positions of cun, guan and chi pulses automatically in terms of the amplitudes and the signals are then transformed from the time domain (time-amplitude) into the frequency domain (frequency-amplitude) via FFT to obtain the waveforms and frequencies of the cun, guan and chi pulses. It successfully extracts the data from the TCM pulse reading and can be a medical aid system for TCM. Combining the advantages of optical measurement and computer automation, this system provides a non-contact, easy to operate, fast in detection and low-cost equipment design. PMID:25923936

  6. Measuring alpha eigenvalue of a subcritical system by a intense pulsed neutron source

    SciTech Connect

    Hu, Meng-chun; Gong, Jian; Peng, Tai-ping; Li, Zhong-bao; Zhang, Jian-hua; Tang, Deng-pan; Bai, Yun; Peng, Xian-jue; Zeng, Qing

    2015-07-01

    Intense-Pulsed-Neutron-Source (IPNS) technique is a new approach to measure the subcriticality of a reactor system, which has been theoretically analyzed by us while not been verified in experiment in other reference. In INPS technique the reactivity is derived via the system response to a prompt pulsed neutron source. The method utilizes very intense neutron pulses (about 1010 neutrons/pulse) with the duration ranging from 10 ns to 100 ns, which are generated by the dense plasma focus (DPF) device filled with pure DT mixture as the working gas. The neutron pulse in high intensity provides the opportunity to measure the signal using a scintillator and a photo-multiplier tube (PMT) (the intense pulse radiation measure method) with the flight distance of only twenty centimeters. The attenuation of the dense plasma focus device must be faster than the subcritical system so that the attenuation of the system can be researched. In this paper, after a neutron pulse is injected into the subcritical reactor, the subcriticality is determined by measuring the instantaneous characteristics of the leaking reactor neutron. The Monte Carlo analysis shows that, with the linear arrangement of the dense plasma focus, the subcritical system and the detector, the signal-to-noise ratio at the measure point meets the investigate requirement, in which the 14 MeV neutrons are attenuated by the subcritical system. The detector is close with the subcritical system to reduce the influence of the outer background and the spread of time-of-flight of the neutrons. The measure system utilizing gated detection technology is characterized with fast attenuation time and large linear current, the a value obtained with this method is 2.05 μs{sup -1} while the measurements using the {sup 252}Cf stochastic pulsed source method and the Rossi-a method were 2.18μs{sup -1} and 2.16μs{sup -1}.It showed that the measured result obtained with dense plasma focus instantaneous pulsed source is consistent

  7. Development of ultra-short pulse VUV laser system for nanoscale processing

    NASA Astrophysics Data System (ADS)

    Katto, Masahito; Zushi, Hironari; Nagaya, Wataru; Harano, Shinya; Matsumoto, Ryota; Yokotani, Atushi; Kaku, Masanori; Kubodera, Shoichi; Miyanaga, Noriaki

    2010-11-01

    We have developed intense vacuum ultraviolet (VUV) radiation sources for advanced material processing, such as photochemical surface reactions and precise processing on a nanometer scale. We have constructed a new VUV laser system to generate sub-picosecond pulses at the wavelength of 126 nm. A seed VUV pulse was generated in Xe as the 7th harmonic of a 882-nm Ti:sapphire laser. The optimum conversion was achieved at the pressure of 1.2 Torr. The seed pulse will be amplified by the Ar2^{*} media generated by an optical-field-induced ionization Ar plasma produced by the Ti:sapphire laser. We have obtained a gain coefficient of g=0.16 cm-1. Our developing system will provide VUV ultra-short pulses with sub-μJ energy at a repetition rate of 1 kHz.

  8. System for adjusting frequency of electrical output pulses derived from an oscillator

    DOEpatents

    Bartholomew, David B.

    2006-11-14

    A system for setting and adjusting a frequency of electrical output pulses derived from an oscillator in a network is disclosed. The system comprises an accumulator module configured to receive pulses from an oscillator and to output an accumulated value. An adjustor module is configured to store an adjustor value used to correct local oscillator drift. A digital adder adds values from the accumulator module to values stored in the adjustor module and outputs their sums to the accumulator module, where they are stored. The digital adder also outputs an electrical pulse to a logic module. The logic module is in electrical communication with the adjustor module and the network. The logic module may change the value stored in the adjustor module to compensate for local oscillator drift or change the frequency of output pulses. The logic module may also keep time and calculate drift.

  9. Design of a pulsed positron system at Trombay

    NASA Astrophysics Data System (ADS)

    Mukherjee, S.; Sharma, S. K.; Maheshwari, Priya; Gupta, S. K.; Pujari, P. K.

    2015-06-01

    We present here the design of a pulsed beam setup to deliver narrow time width positron pulses. The major constituents of the setup include- 22Na radioactive source and moderator assembly, ExB deflector for filtering out high energy positron and gamma rays, chopper-prebuncher-buncher assembly for time bunching of the slow positrons. In the ExB section, crossed electric and magnetic fields guide the slow positrons through an off-centered hole in a tungsten block. The initial beam will then be time bunched by using a reflection type chopper and a double gap prebuncher. The main buncheris designed as a quarter wave resonator with base frequency of 150 MHz.To prevent the sagging of the cantilevered inner tube of the resonator, we will support the inner conductor using an alumina post. There will be provision of tuning the frequency by using a tuner made of conducting material. The incident beam energy will be varied by biasing the sample.

  10. Pulsed power

    NASA Astrophysics Data System (ADS)

    Stone, David H.

    Pulsed power systems are critical elements for such prospective weapons technologies as high-power microwaves, electrothermal and electromagnetic projectile launchers, neutral particle beams, space-based FELs, ground-based lasers, and charged particle beams. Pulsed power will also be essential for the development of nonweapon military systems such as lidars and ultrawideband radars, and could serve as the bases for nuclear weapon effect simulators. The pulsed power generation requirements for each of these systems is considered.

  11. Using an active temporal compensating system to achieve the super-Gaussian pulses in high-power lasers

    NASA Astrophysics Data System (ADS)

    Wang, Yulei; Liu, Rui; Yuan, Hang; Li, Sensen; Liu, Zhaohong; Zhu, Xuehua; He, Weiming; Lv, Zhiwei

    2015-08-01

    In high-power solid-state laser, initiative pulse shaping can help improve the output laser's performance. The evaluation for output laser pulse is also incomplete. In this paper, we propose a method of initiative pulse shaping by using arbitrary waveform generator (AWG), and establish a relatively complete evaluation system for the output pulses shape simultaneously. It achieves the super-Gaussian pulse output with high SNR (signal-to-noise ratio). As a consequence, a square laser pulse with pulse adjustable width ~5ns, rising time 197ps is obtained. The power imbalance of the output square pulse is 3.72%. The similarity between the eight-order super-Gaussian pulse and the one we get from experiment reached 99%.

  12. Pulsed multiwavelength laser ranging system. Ph.D. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Abshire, J. B.

    1982-01-01

    A pulsed multiwavelength laser ranging system for measuring atmospheric delay was built and tested, and its theoretical performance limits were calculated. The system uses a dye modelocked ND:YAG laser, which transmits 70 psec wide pulses simultaneously at 1064, 532, and 355 nm. The differential delay of the 1064 and 355 nm pulses is measured by a specially calibrated waveform digitizer to estimate the dry atmospheric delay. The delay time of the 532 nm pulse is used to measure the target distance. Static crossed field photomultipliers are used as detectors for all wavelengths. Theoretical analysis shows that path curvature and atmospheric turbulence are fundamental limits to the ranging accuracy of both single and multicolor systems operating over horizontal paths. For two color systems, an additional error is caused by the uncertainty in the path averaged water vapor. The standard deviation of the multicolor instrument's timing measurements is directly proportional to the laser pulse width plus photomultiplier jitter divided by the square root of the received photoelectron number. The prototype system's maximum range is km, which is limited by atmospheric and system transmission losses at 355 nm. System signal detection and false alarm calculations are also presented.

  13. Dosage, duplication, and diploidization: clarifying the interplay of multiple models for duplicate gene evolution over time.

    PubMed

    Conant, Gavin C; Birchler, James A; Pires, J Chris

    2014-06-01

    Requirements to maintain dosage balance shape many genome-scale patterns in organisms, including the resolution of whole genome duplications (WGD), as well as the varied effects of aneuploidy, segmental duplications, tandem duplications, gene copy number variations (CNV), and epigenetic marks. Like neofunctionalization and subfunctionalization, the impact of absolute and relative dosage varies over time. These variations are of particular importance in understanding the role of dosage in the evolution of polyploid organisms. Numerous investigations have found the consequences of polyploidy remain distinct from small-scale duplications (SSD). This observation is significant as all flowering plants have experienced at least two ancient polyploid events, and many angiosperm lineages have undergone additional rounds of polyploidy. Intriguingly, recent studies indicate a link between how epigenetic marks in recent allopolyploids may induce immediate changes in gene expression and the longer-term patterns of biased fractionation and chromosomal evolution. We argue that dosage effects represent one aspect of an emerging pluralistic framework, a framework that will use biophysics, genomic technologies, and systems-level models of cells to broaden our view of how genomes evolve. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Determination of continuous system transfer functions from sampled pulse response data

    NASA Astrophysics Data System (ADS)

    Jordan, Jay B.

    1993-09-01

    A method for determining the transfer function of a continuous system from sampled responses to single and multiple pulse excitation is presented. The method is an extension of the sampled edge response method pioneered by the theoretical work of A. Papoulis in 1962 and the application of the theory to optical systems by B. Tatian in 1965. Occasions arise when pulse rather than step function stimuli are available for system excitations. In such cases, the method presented is practical for determining the system transfer function. The use of anti- aliasing filters and estimation of non-bandwidth limited transfer functions are also discussed.

  15. A nanosecond pulsed laser heating system for studying liquid and supercooled liquid films in ultrahigh vacuum

    SciTech Connect

    Xu, Yuntao; Dibble, Collin J.; Petrik, Nikolay G.; Smith, R. Scott; Joly, Alan G.; Tonkyn, Russell G.; Kay, Bruce D.; Kimmel, Greg A.

    2016-04-26

    A pulsed laser heating system has been developed that enables investigations of the dynamics and kinetics of nanoscale liquid films and liquid/solid interfaces on the nanosecond timescale in ultrahigh vacuum (UHV). Details of the design, implementation and characterization of a nanosecond pulsed laser system for transiently heating nanoscale films are described. Nanosecond pulses from a Nd:YAG laser are used to rapidly heat thin films of adsorbed water or other volatile materials on a clean, well-characterized Pt(111) crystal in UHV. Heating rates of ~1010 K/s for temperature increases of ~100 – 200 K are obtained. Subsequent rapid cooling (~5 × 109 K/s) quenches the film, permitting in-situ, post-mortem analysis using a variety of surface science techniques. Lateral variations in the laser pulse energy are ~ ± 3% leading to a temperature uncertainty of ~ ± 5 K for a temperature jump of 200 K. Initial experiments with the apparatus demonstrate that crystalline ice films initially held at 90 K can be rapidly transformed into liquid water films with T > 273 K. No discernable recrystallization occurs during the rapid cooling back to cryogenic temperatures. In contrast, amorphous solid water films heated below the melting point rapidly crystallize. The nanosecond pulsed laser heating system can prepare nanoscale liquid and supercooled liquid films that persist for nanoseconds per heat pulse in an UHV environment, enabling experimental studies of a wide range of phenomena in liquids and at liquid/solid interfaces.

  16. A compact field-portable double-pulse laser system to enhance laser induced breakdown spectroscopy.

    PubMed

    Li, Shuo; Liu, Lei; Yan, Aidong; Huang, Sheng; Huang, Xi; Chen, Rongzhang; Lu, Yongfeng; Chen, Kevin

    2017-02-01

    This paper reports the development of a compact double-pulse laser system to enhance laser induced breakdown spectroscopy (LIBS) for field applications. Pumped by high-power vertical-surface emitting lasers, the laser system that produces 16 ns pulse at 12 mJ/pulse with total weight less than 10 kg is developed. The inter-pulse delay can be adjusted from 0μs with 0.5μs increment. Several LIBS experiments were carried out on NIST standard aluminum alloy samples. Comparing with the single-pulse LIBS, up to 9 times enhancement in atomic emission line was achieved with continuum background emission reduced by 70%. This has led to up to 10 times improvement in the limit of detection. Signal stability was also improved by 128% indicating that a more robust and accurate LIBS measurement can be achieved using a compact double-pulse laser system. This paper presents a viable and field deployable laser tool to dramatically improve the sensitivity and applicability of LIBS for a wide array of applications.

  17. A compact field-portable double-pulse laser system to enhance laser induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Shuo; Liu, Lei; Yan, Aidong; Huang, Sheng; Huang, Xi; Chen, Rongzhang; Lu, Yongfeng; Chen, Kevin

    2017-02-01

    This paper reports the development of a compact double-pulse laser system to enhance laser induced breakdown spectroscopy (LIBS) for field applications. Pumped by high-power vertical-surface emitting lasers, the laser system that produces 16 ns pulse at 12 mJ/pulse with total weight less than 10 kg is developed. The inter-pulse delay can be adjusted from 0 μ s with 0.5 μ s increment. Several LIBS experiments were carried out on NIST standard aluminum alloy samples. Comparing with the single-pulse LIBS, up to 9 times enhancement in atomic emission line was achieved with continuum background emission reduced by 70%. This has led to up to 10 times improvement in the limit of detection. Signal stability was also improved by 128% indicating that a more robust and accurate LIBS measurement can be achieved using a compact double-pulse laser system. This paper presents a viable and field deployable laser tool to dramatically improve the sensitivity and applicability of LIBS for a wide array of applications.

  18. The design and construction of a pulsed beam generation system based on high intensity cyclotron

    NASA Astrophysics Data System (ADS)

    An, ShiZhong; Yin, ZhiGuo; Li, PengZhan; Song, GuoFang; Wu, LongCheng; Guan, FengPing; Xie, HuaiDong; Jia, XianLu; Lu, YinLong; Zhang, TianJue

    2011-12-01

    In order to perform the studies on a pulsed beam generation system based on a high intensity cyclotron, a test beam line with a pulsed beam generation for a 10 MeV compact cyclotron (CYCIAE-10) has been designed and constructed at China Institute of Atomic Energy (CIAE). A 70 MHz continuous H-beam can be pulsed to the pulse length of less than 10 ns with a repetition rate of 4.4 MHz. The sine waveform with a frequency of 2.2 MHz is adopted for the chopper and a mesh structure with single drift and dual gaps is used for the 70 MHz buncher. A helical resonator is designed and constructed based on simulations and experiments on the RF matching for the chopper. A helical inductance loop that is exceptionally large of its kind and equipped with water cooling for the resonator has been successfully wound and a 500 W solid RF amplifier has been manufactured. A special measuring device has been designed, which can be used to measure both the DC beam and the pulsed beam. The required pulsed beam was obtained after pulsed beam tuning.

  19. Generation of multiple analog pulses with different duty cycles within VME control system for ICRH Aditya system

    NASA Astrophysics Data System (ADS)

    Joshi, Ramesh; Singh, Manoj; Jadav, H. M.; Misra, Kishor; Kulkarni, S. V.; ICRH-RF Group

    2010-02-01

    Ion Cyclotron Resonance Heating (ICRH) is a promising heating method for a fusion device due to its localized power deposition profile, a direct ion heating at high density, and established technology for high RF power generation and transmission at low cost. Multiple analog pulse with different duty cycle in master of digital pulse for Data acquisition and Control system for steady state RF ICRH System(RF ICRH DAC) to be used for operating of RF Generator in Aditya to produce pre ionization and second analog pulse will produce heating. The control system software is based upon single digital pulse operation for RF source. It is planned to integrate multiple analog pulses with different duty cycle in master of digital pulse for Data acquisition and Control system for RF ICRH System(RF ICRH DAC) to be used for operating of RF Generator in Aditya tokamak. The task of RF ICRH DAC is to control and acquisition of all ICRH system operation with all control loop and acquisition for post analysis of data with java based tool. For pre ionization startup as well as heating experiments using multiple RF Power of different powers and duration. The experiment based upon the idea of using single RF generator to energize antenna inside the tokamak to radiate power twise, out of which first analog pulse will produce pre ionization and second analog pulse will produce heating. The whole system is based on standard client server technology using tcp/ip protocol. DAC Software is based on linux operating system for highly reliable, secure and stable system operation in failsafe manner. Client system is based on tcl/tk like toolkit for user interface with c/c++ like environment which is reliable programming languages widely used on stand alone system operation with server as vxWorks real time operating system like environment. The paper is focused on the Data acquisition and monitoring system software on Aditya RF ICRH System with analog pulses in slave mode with digital pulse in

  20. ALTERNATIVES TO DUPLICATE DIET METHODOLOGY

    EPA Science Inventory

    Duplicate Diet (DD) methodology has been used to collect information about the dietary exposure component in the context of total exposure studies. DD methods have been used to characterize the dietary exposure component in the NHEXAS pilot studies. NERL desired to evaluate it...

  1. Office Duplication Practices Curriculum Guide.

    ERIC Educational Resources Information Center

    East Texas State Univ., Commerce. Occupational Curriculum Lab.

    As one of a series of curriculum guides for office education programs in Texas, this guide contains 24 units of instruction in office duplication practices. Each of the units contains a unit outline that lists unit objective, specific objectives, teacher and student activities, estimated completion time, re-teach activities, and resources; and a…

  2. Duplicated Information Acquired by Libraries.

    ERIC Educational Resources Information Center

    White, Carl M.

    The object of this study is to make a start toward determining the extent of duplicated information that is being acquired in spite of customary precautions to avoid it. Referring to a specific case, the percentages in Table II show the frequency of appearance in five other works of 19 items in Mitchell's "Encyclopedia of American Politics." While…

  3. ALTERNATIVES TO DUPLICATE DIET METHODOLOGY

    EPA Science Inventory

    Duplicate Diet (DD) methodology has been used to collect information about the dietary exposure component in the context of total exposure studies. DD methods have been used to characterize the dietary exposure component in the NHEXAS pilot studies. NERL desired to evaluate it...

  4. Origination of new immunological functions in the costimulatory molecule B7-H3: the role of exon duplication in evolution of the immune system.

    PubMed

    Sun, Jing; Fu, Fengqing; Gu, Wenchao; Yan, Ruhong; Zhang, Guangbo; Shen, Zhiyong; Zhou, Yinghui; Wang, Han; Shen, Bairong; Zhang, Xueguang

    2011-01-01

    B7-H3, a recently identified B7 family member, has different isoforms in human and mouse. Mouse B7-H3 gene has only one isoform (2IgB7-H3) with two Ig-like domains, whereas human B7-H3 has two isoforms (2IgB7-H3 and 4IgB7-H3). In this study a systematic genomic survey across various species from teleost fishes to mammals revealed that 4IgB7-H3 isoform also appeared in pigs, guinea pigs, cows, dogs, African elephants, pandas, megabats and higher primate animals, which resulted from tandem exon duplication. Further sequence analysis indicated that this duplication generated a new conserved region in the first IgC domain, which might disable 4IgB7-H3 from releasing soluble form, while 2IgB7-H3 presented both membrane and soluble forms. Through three-dimensional (3D) structure modeling and fusion-protein binding assays, we discovered that the duplicated isoform had a different structure and might bind to another potential receptor on activated T cells. In T cell proliferation assay, human 2IgB7-H3 (h2IgB7-H3) and mouse B7-H3 (mB7-H3) both increased T cell proliferation and IL-2, IFN-γ production, whereas human 4IgB7-H3 (h4IgB7-H3) reduced cytokine production and T cell proliferation compared to control. Furthermore, both h2IgB7-H3 and mB7-H3 upregulated the function of lipopolysacharide (LPS)-activated monocyte in vitro. Taken together, our data implied that during the evolution of vertebrates, B7-H3 exon duplication contributed to the generation of a new 4IgB7-H3 isoform in many mammalian species, which have carried out distinct functions in the immune responses.

  5. NDCX-II PULSED POWER SYSTEM AND INDUCTION CELLS

    SciTech Connect

    Waldron, W.L.; Reginato, L.L.; Leitner, M.

    2009-06-01

    The Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL) is currently finalizing the design of NDCX-II, the second phase of the Neutralized Drift Compression Experiment, which will use an ion beam to explore Warm Dense Matter (WDM) and Inertial Fusion Energy (IFE) target hydrodynamics. The ion induction accelerator will include induction cells and Blumleins from the decommissioned Advanced Test Accelerator (ATA) at Lawrence Livermore National Laboratory (LLNL). A test stand has been built at Lawrence Berkeley National Laboratory (LBNL) to test refurbished ATA induction cells and pulsed power hardware for voltage holding and ability to produce various compression and acceleration waveforms. The performance requirements, design modifications, and test results will be presented.

  6. In vivo manipulation of biological systems with femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Nishimura, Nozomi; Schaffer, Chris B.; Kleinfeld, David

    2006-05-01

    Femtosecond laser pulses have the unique ability to deposit energy into a microscopic volume in the bulk of a material that is transparent to the laser wavelength without affecting the surface of the material. Here we review the use of this capability to disrupt specifically targeted structures in live cells and animals with the goal of elucidating function and modeling disease states. Particular attention will be paid to recent work that uses femtosecond laser disruption to injure cerebral blood vessels that lie below the brain surface in a live, anesthetized rat. By varying the degree of injury, the vessel can be made to leak blood plasma, to rupture, or to clot. This technique thus provides a versatile model of cerebrovascular disorders such as small-scale stroke.

  7. Electromagnetic pulse (EMP) interaction with electric power systems. Power Systems Technology Program. Final report

    SciTech Connect

    Zaininger, H.W.

    1984-08-01

    A high altitude nuclear burst, detonated at a height of 50 km or more, causes two types of electromagnetic pulses (EMP) - high altitude EMP (HEMP) and magnetohydrodynamic EMP (MHD-EMP). This high altitude EMP scenario is of principal concern when assessing the effects of EMP on electric power systems, because the total United States can be simultaneously illuminated by HEMP and MHD-EMP can cover a large area of up to several hundred kilometers in diameter. The purpose of this project was first to define typical electrical power system characteristics for EMP analysis, and second, to determine reasonable worst case EMP induced surges on overhead electric power system transmission and distribution lines for reasonable assumptions, using unclassified HEMP and MHD-EMP electric field waveforms.

  8. Design and application of pulse information acquisition and analysis system with dynamic recognition in traditional Chinese medicine.

    PubMed

    Zhang, Jian; Niu, Xin; Yang, Xue-zhi; Zhu, Qing-wen; Li, Hai-yan; Wang, Xuan; Zhang, Zhi-guo; Sha, Hong

    2014-09-01

    To design the pulse information which includes the parameter of pulse-position, pulse-number, pulse-shape and pulse-force acquisition and analysis system with function of dynamic recognition, and research the digitalization and visualization of some common cardiovascular mechanism of single pulse. To use some flexible sensors to catch the radial artery pressure pulse wave and utilize the high frequency B mode ultrasound scanning technology to synchronously obtain the information of radial extension and axial movement, by the way of dynamic images, then the gathered information was analyzed and processed together with ECG. Finally, the pulse information acquisition and analysis system was established which has the features of visualization and dynamic recognition, and it was applied to serve for ten healthy adults. The new system overcome the disadvantage of one-dimensional pulse information acquisition and process method which was common used in current research area of pulse diagnosis in traditional Chinese Medicine, initiated a new way of pulse diagnosis which has the new features of dynamic recognition, two-dimensional information acquisition, multiplex signals combination and deep data mining. The newly developed system could translate the pulse signals into digital, visual and measurable motion information of vessel.

  9. Analysis and Design of Ultra Wide-Band and High-Power Microwave Pulse Interactions With Electronic Circuits and Systems

    DTIC Science & Technology

    2007-02-28

    SUBJECT TERMS Electromagnetic interference. Ultrawide- band pulses . High-power microwave pulses . Interactions with electronic circuits and systems. 16...Eric Michielssen Prof. V. V. Liepa Report Period: June 15, 2001 to August 31, 2006 20070516067 PROJECT SUMMARY Ultra wide- band ( UWB ) environments and...or UWB pulses from large targets (aircraft, vehicles, boxes, etc.) with penetrating wires, apertures, cracks, doors, and antennas. (2). Digital

  10. Analysis of the cryogenic system behavior for pulsed heat load in EAST

    NASA Astrophysics Data System (ADS)

    Hu, L. B.; Zhuang, M.; Zhou, Z. W.; Xia, G. H.

    2014-01-01

    EAST is the first full superconducting fusion device. The plasma is confined by the magnetic fields generated from a large set of superconducting magnets which are made of cable in-conduit conductor (CICC). In operation, these magnets suffer heat loads from thermal and nuclear radiation from the surrounding components and plasma as well as the eddy currents and the AC losses generated within the magnets, together with the heat conduction through supports and the resistive heat generated at the current lead transiting to room temperature. The cryogenic system of our EAST consists of a 2kW/4K helium refrigerator and a distribution system for the cooling of poloidal field (PF) and toroidal field (TF) coils, structures, thermal shields, buslines and current leads. Pulsed heat load is the main difference between the cryogenic system of a full superconducting Tokamak system and other large scale cryogenic systems. The cryogenic system operates in a pulsed heat loads mode requiring the helium refrigerator to remove periodically large heat loads in time. At the same time, the cryogenic system parameters such as helium cooling superconducting magnets, helium refrigerator and helium distribution system are changing. In this paper, the variation range of the parameters of superconducting magnets and refrigerator has been analyzed in the typical plasma discharge mode. The control scheme for the pulsed loads characteristics of the cryogenic system has been proposed, the implementation of which helps to smooth the pulse loads and to improve the stability of the operation of the cryogenic system.

  11. Analysis of the cryogenic system behavior for pulsed heat load in EAST

    SciTech Connect

    Hu, L. B.; Zhuang, M.; Zhou, Z. W.; Xia, G. H.

    2014-01-29

    EAST is the first full superconducting fusion device. The plasma is confined by the magnetic fields generated from a large set of superconducting magnets which are made of cable in-conduit conductor (CICC). In operation, these magnets suffer heat loads from thermal and nuclear radiation from the surrounding components and plasma as well as the eddy currents and the AC losses generated within the magnets, together with the heat conduction through supports and the resistive heat generated at the current lead transiting to room temperature. The cryogenic system of our EAST consists of a 2kW/4K helium refrigerator and a distribution system for the cooling of poloidal field (PF) and toroidal field (TF) coils, structures, thermal shields, buslines and current leads. Pulsed heat load is the main difference between the cryogenic system of a full superconducting Tokamak system and other large scale cryogenic systems. The cryogenic system operates in a pulsed heat loads mode requiring the helium refrigerator to remove periodically large heat loads in time. At the same time, the cryogenic system parameters such as helium cooling superconducting magnets, helium refrigerator and helium distribution system are changing. In this paper, the variation range of the parameters of superconducting magnets and refrigerator has been analyzed in the typical plasma discharge mode. The control scheme for the pulsed loads characteristics of the cryogenic system has been proposed, the implementation of which helps to smooth the pulse loads and to improve the stability of the operation of the cryogenic system.

  12. Research of pulse signal processing based on sleep-monitoring alarm system

    NASA Astrophysics Data System (ADS)

    Zhang, Kaisheng; Zeng, Yuan

    2009-07-01

    From pulse diagnosis of Chinese herbalist doctor to the research of cardiovascular system by modem iatrology,they all have showed and proved that human pulse has a good affinity with diseases,especially cardiovascular diseases. Human pulse contains much physical information, and it will be propitious to know the human healthy state early so as to get therapy and recovery early when pulse signal is often detected and analyzed. study how to use the embedded microcontroller to transmit physiological signal from human to personal computer by infrared communication, and the normal sphygmic parameter in one's sleeping is compared with the one measured in order to judge whether one's sleeping condition is normal, finally ascertain the best control plan.

  13. Computational model for time development of the EM field in pulsed laser systems

    NASA Astrophysics Data System (ADS)

    Skrabelj, D.; Marincek, M.; Drevensek-Olenik, I.; Leskovar, M.; Copic, M.

    2007-05-01

    A computational model, which describes EM field formation in a pulsed laser from a randomly generated initial spontaneous field inside the laser cavity has been developed. The model is based on a two-dimensional fast Fourier transform and describes a real laser system taking into account a lensing and a diaphragm effect of the laser rod. The laser cavity is described by five effective planes, which represent different laser cavity elements-the back and the front mirror, the Q-switch element and the laser rod. At each plane the EM field is calculated in real space and propagation between the planes is achieved in Fourier space by multiplication with an appropriate phase factor. The computational time needed for simulation of a realistic pulse formation is in order of minutes. The model can predict the shape and the integral energy of the pulse, its transverse profile at different distances from the front mirror (including near and far field) and beam divergence. The results of the model were found to be in good agreement with measured parameters for a Q-switched ruby laser system running in stable as well as unstable cavity configurations. The temporal shape of a laser pulse was measured and calculated not only for the ruby laser, but also for a Nd:YAG laser. It was found that FWHM of a pulse produced by ruby laser is three times longer than FWHM of a pulse produced by Nd:YAG laser.

  14. The System of Nanosecond 280-KeV He+ Pulsed Beam

    SciTech Connect

    Junphong, P.; Ano, V.; Lekprasert, B.; Suwannakachorn, D.; Thongnopparat, N.; Vilaithong, T.; Wiedemann, H.; /SLAC /SLAC, SSRL

    2006-05-01

    At Fast Neutron Research Facility, the 150 kV-pulses neutron generator is being upgraded to a 280-kV-pulsed-He beam for time-of-flight Rutherford backscattering spectrometry. It involves replacing the existing beam line elements by a multicusp ion source, a 400-kV accelerating tube, 45{sup o}-double focusing dipole magnet and quadrupole lens. The multicusp ion source is a compact filament-driven of 2.6 cm in diameter and 8 cm in length. The current extracted is 20.4 {micro}A with 13 kV of extraction voltage and 8.8 kV of Einzel lens voltage. The beam emittance has found to vary between 6-12 mm mrad. The beam transport system has to be redesigned based on the new elements. The important part of a good pulsed beam depends on the pulsing system. The two main parts are the chopper and buncher. An optimized geometry for the 280 keV pulsed helium ion beam will be presented and discussed. The PARMELA code has been used to optimize the space charge effect, resulting in pulse width of less than 2 ns at a target. The calculated distance from a buncher to the target is 4.6 m. Effects of energy spread and phase angle between chopper and buncher have been included in the optimization of the bunch length.

  15. 54  J pulses with 18  nm bandwidth from a diode-pumped chirped-pulse amplification laser system.

    PubMed

    Hornung, Marco; Liebetrau, Hartmut; Keppler, Sebastian; Kessler, Alexander; Hellwing, Marco; Schorcht, Frank; Becker, Georg A; Reuter, Maria; Polz, Jens; Körner, Jörg; Hein, Joachim; Kaluza, Malte C

    2016-11-15

    We report on results from the fully diode-pumped chirped-pulse amplification laser system Polaris. Pulses were amplified to a maximum energy of 54.2 J before compression. These pulses have a full width at half-maximum spectral bandwidth of 18 nm centered at 1033 nm and are generated at a repetition rate of 0.02 Hz. To the best of our knowledge, these are the most energetic broadband laser pulses generated by a diode-pumped laser system so far. Due to the limited size of our vacuum compressor, only attenuated pulses could be compressed to a duration of 98 fs containing an energy of 16.7 J, which leads to a peak power of 170 TW. These pulses could be focused to a peak intensity of 1.3×1021  W/cm2. Having an ultra-high temporal contrast of 1012 with respect to amplified spontaneous emission these laser pulses are well suited for high-intensity laser-matter experiments.

  16. Technical specifications manual for the MARK-1 pulsed ionizing radiation detection system. Volume 1

    SciTech Connect

    Lawrence, R.S.; Harker, Y.D.; Jones, J.L.; Hoggan, J.M.

    1993-03-01

    The MARK-1 detection system was developed by the Idaho National Engineering Laboratory for the US Department of Energy Office of Arms Control and Nonproliferation. The completely portable system was designed for the detection and analysis of intense photon emissions from pulsed ionizing radiation sources. This manual presents the technical design specifications for the MARK-1 detection system and was written primarily to assist the support or service technician in the service, calibration, and repair of the system. The manual presents the general detection system theory, the MARK-1 component design specifications, the acquisition and control software, the data processing sequence, and the system calibration procedure. A second manual entitled: Volume 2: Operations Manual for the MARK-1 Pulsed Ionizing Radiation Detection System (USDOE Report WINCO-1108, September 1992) provides a general operational description of the MARK-1 detection system. The Operations Manual was written primarily to assist the field operator in system operations and analysis of the data.

  17. Autopolyploidy genome duplication preserves other ancient genome duplications in Atlantic salmon (Salmo salar)

    PubMed Central

    Davidson, William S.

    2017-01-01

    Salmonids (e.g. Atlantic salmon, Pacific salmon, and trouts) have a long legacy of genome duplication. In addition to three ancient genome duplications that all teleosts are thought to share, salmonids have had one additional genome duplication. We explored a methodology for untangling these duplications from each other to better understand them in Atlantic salmon. In this methodology, homeologous regions (paralogous/duplicated genomic regions originating from a whole genome duplication) from the most recent genome duplication were assumed to have duplicated genes at greater density and have greater sequence similarity. This assumption was used to differentiate duplicated gene pairs in Atlantic salmon that are either from the most recent genome duplication or from earlier duplications. From a comparison with multiple vertebrate species, it is clear that Atlantic salmon have retained more duplicated genes from ancient genome duplications than other vertebrates--often at higher density in the genome and containing fewer synonymous mutations. It may be that polysomic inheritance is the mechanism responsible for maintaining ancient gene duplicates in salmonids. Polysomic inheritance (when multiple chromosomes pair during meiosis) is thought to be relatively common in salmonids compared to other vertebrate species. These findings illuminate how genome duplications may not only increase the number of duplicated genes, but may also be involved in the maintenance of them from previous genome duplications as well. PMID:28241055

  18. Autopolyploidy genome duplication preserves other ancient genome duplications in Atlantic salmon (Salmo salar).

    PubMed

    Christensen, Kris A; Davidson, William S

    2017-01-01

    Salmonids (e.g. Atlantic salmon, Pacific salmon, and trouts) have a long legacy of genome duplication. In addition to three ancient genome duplications that all teleosts are thought to share, salmonids have had one additional genome duplication. We explored a methodology for untangling these duplications from each other to better understand them in Atlantic salmon. In this methodology, homeologous regions (paralogous/duplicated genomic regions originating from a whole genome duplication) from the most recent genome duplication were assumed to have duplicated genes at greater density and have greater sequence similarity. This assumption was used to differentiate duplicated gene pairs in Atlantic salmon that are either from the most recent genome duplication or from earlier duplications. From a comparison with multiple vertebrate species, it is clear that Atlantic salmon have retained more duplicated genes from ancient genome duplications than other vertebrates--often at higher density in the genome and containing fewer synonymous mutations. It may be that polysomic inheritance is the mechanism responsible for maintaining ancient gene duplicates in salmonids. Polysomic inheritance (when multiple chromosomes pair during meiosis) is thought to be relatively common in salmonids compared to other vertebrate species. These findings illuminate how genome duplications may not only increase the number of duplicated genes, but may also be involved in the maintenance of them from previous genome duplications as well.

  19. Effect of removal of duplicate isolates on cumulative susceptibility reports.

    PubMed

    White, R L; Friedrich, L V; Burgess, D S; Brown, E W; Scott, L E

    2001-04-01

    The objective of our study is to assess the impact of different methods of duplicate isolate removal on cumulative susceptibility reports. Over a 1-year period, we studied the effect of 3 methods of duplicate isolate removal on the cumulative percentage susceptibility of 9 Gram-negative bacilli to 15 antimicrobials. Raw data from which no duplicate isolates were removed (NR) were generated by the Sensititre breakpoint susceptibility testing system. D3 and D7 were methods of duplicate isolate removal defined as follows: same patient, bacterial species, irrespective of susceptibility within either three (D3) or seven (D7) calendar days of the date of the previous culture. The third method evaluated was an algorithm utilized by Cerner, a laboratory management program that defines duplicate isolates as follows: same patient, bacterial species, and NCCLS susceptibility category to an individual antimicrobial. Differences in percentage susceptibility between the three methods of duplicate isolate removal and NR were assessed. The number of isolates studied ranged from 80 (E. aerogenes) to 681 (P. aeruginosa). Of the methods of duplicate isolate removal, the highest percentage susceptibility occurred most frequently with Cerner followed by D7 and D3. Differences in percentage susceptibility between methods of removal and NR ranged from -11 to 25%, -5 to 8%, and -3 to 10%, with Cerner, D3, and D7, respectively. The percentage susceptibility was at least 5% higher than NR with a method of removal for 15 individual organism/antimicrobial combinations in which susceptibility was > or = 70% by at least one of the methods. These occurred most frequently with Enterobacter species and Cerner. Although there is no consensus on the ideal method of duplicate isolate removal, one should be cognizant that these manipulations may produce different cumulative susceptibility reports.

  20. Synchronized femtosecond laser pulse switching system based nano-patterning technology

    NASA Astrophysics Data System (ADS)

    Sohn, Ik-Bu; Choi, Hun-Kook; Yoo, Dongyoon; Noh, Young-Chul; Sung, Jae-Hee; Lee, Seong-Ku; Ahsan, Md. Shamim; Lee, Ho

    2017-07-01

    This paper demonstrates the design and development of a synchronized femtosecond laser pulse switching system and its applications in nano-patterning of transparent materials. Due to synchronization, we are able to control the location of each irradiated laser pulse in any kind of substrate. The control over the scanning speed and scanning step of the laser beam enables us to pattern periodic micro/nano-metric holes, voids, and/or lines in various materials. Using the synchronized laser system, we pattern synchronized nano-holes on the surface of and inside various transparent materials including fused silica glass and polymethyl methacrylate to replicate any image or pattern on the surface of or inside (transparent) materials. We also investigate the application areas of the proposed synchronized femtosecond laser pulse switching system in a diverse field of science and technology, especially in optical memory, color marking, and synchronized micro/nano-scale patterning of materials.

  1. Thickness determination of polymeric multilayer surface protection systems for concrete by means of pulse thermography

    NASA Astrophysics Data System (ADS)

    Altenburg, S. J.; Krankenhagen, R.; Bavendiek, F.

    2017-02-01

    For thickness determination of polymer based surface protection systems for concrete surfaces, so far only destructive measurement techniques are available. Pulse thermography appears to be well suited for non-destructive thickness evaluation in these systems. Here, we present first results of the development of a respective measurement and analysis procedure. Since surface protection systems consist of a number of layers, a model for the calculation of the surface temperature of a multi-layer structure on a semi-infinite (concrete) substrate in pulse thermography setup was developed. It considers semitransparency of the upmost layer and thermal losses at the surface. It also supports the use of an arbitrary temporal shape of the heating pulse to properly describe the measurement conditions for different heat sources. Simulations for one and three layers on the substrate are presented and first results from fitting the model to experimental data for thickness determination and verification of the model are presented.

  2. Oscillatory pulses and wave trains in a bistable reaction-diffusion system with cross diffusion

    NASA Astrophysics Data System (ADS)

    Zemskov, Evgeny P.; Tsyganov, Mikhail A.; Horsthemke, Werner

    2017-01-01

    We study waves with exponentially decaying oscillatory tails in a reaction-diffusion system with linear cross diffusion. To be specific, we consider a piecewise linear approximation of the FitzHugh-Nagumo model, also known as the Bonhoeffer-van der Pol model. We focus on two types of traveling waves, namely solitary pulses that correspond to a homoclinic solution, and sequences of pulses or wave trains, i.e., a periodic solution. The effect of cross diffusion on wave profiles and speed of propagation is analyzed. We find the intriguing result that both pulses and wave trains occur in the bistable cross-diffusive FitzHugh-Nagumo system, whereas only fronts exist in the standard bistable system without cross diffusion.

  3. Short pulse acquisition by low sampling rate with phase-coded sequence in lidar system

    NASA Astrophysics Data System (ADS)

    Wu, Long; Xu, Jiajia; Lv, Wentao; Yang, Xiaocheng

    2016-11-01

    The requirement of high range resolution results in impractical collection of every returned laser pulse due to the limited response speed of imaging detectors. This paper proposes a phase coded sequence acquisition method for signal preprocessing. The system employs an m-sequence with N bits for demonstration with the detector controlled to accumulate N+1 bits of the echo signals to deduce one single returned laser pulse. An indoor experiment achieved 2 μs resolution with the sampling period of 28 μs by employing a 15-bit m-sequence. This method shows the potential to improve the detection capabilities of narrow laser pulses with the detectors at a low frame rate, especially for the imaging lidar systems. Meanwhile, the lidar system is able to improve the range resolution with available detectors of restricted performance.

  4. Oscillatory pulses and wave trains in a bistable reaction-diffusion system with cross diffusion.

    PubMed

    Zemskov, Evgeny P; Tsyganov, Mikhail A; Horsthemke, Werner

    2017-01-01

    We study waves with exponentially decaying oscillatory tails in a reaction-diffusion system with linear cross diffusion. To be specific, we consider a piecewise linear approximation of the FitzHugh-Nagumo model, also known as the Bonhoeffer-van der Pol model. We focus on two types of traveling waves, namely solitary pulses that correspond to a homoclinic solution, and sequences of pulses or wave trains, i.e., a periodic solution. The effect of cross diffusion on wave profiles and speed of propagation is analyzed. We find the intriguing result that both pulses and wave trains occur in the bistable cross-diffusive FitzHugh-Nagumo system, whereas only fronts exist in the standard bistable system without cross diffusion.

  5. Stellar duplicity and nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Izzard, Rob

    2014-09-01

    Half or more of all stars more massive than our Sun are orbited by one (or more) companion stars. Many companions are close enough that the evolution of both stars is greatly altered by the transfer of mass and angular momentum from one star to the other. Such mass transfer is highly likely during the late stages of evolution, such as on the giant branches, which are quite coincidentally also when stars undergo interesting nucleosynthesis. Direct mass transfer truncates the (A)GB prematurely compared to single stars and the ensuing stellar envelope is ejected perhaps to form a (chemically peculiar?) planetary nebula. In wider binaries, where one star has captured material from a long-dead companion, we can probe the nucleosynthesis that happened in ancient stars as well as fundamental astrophysical phenomena like wind accretion and circumbinary disc formation. I will focus on recent quantitative work on nucleosynthesis in mass-transfer systems, such as carbon-enhanced metal-poor and barium stars, and highlight some of the key open questions - and opportunities - that will dominate the next decade of duplicitous nucleosynthesis.

  6. Absorption spectrum of a two-level system subjected to a periodic pulse sequence

    DOE PAGES

    Fotso, H. F.; Dobrovitski, V. V.

    2017-06-01

    We investigate how the quantum control of a two-level system (TLS) coupled to photons can modify and tune the TLS’s photon absorption spectrum. Tuning and controlling the emission and the absorption is of much interest e.g. for the development of efficient interfaces between stationary and flying qubits in modern architectures for quantum computation and quantum communication. We consider the periodic pulse control, where the TLS is subjected to a periodic sequence of the near-resonant Rabi driving pulses, each pulse implementing a 180° rotation. For small inter-pulse delays, the absorption spectrum features a pronounced peak of stimulated emission at the pulsemore » frequency, as well as equidistant satellite peaks with smaller spectral weights. As long as the detuning between the carrier frequency of the driving and the TLS transition frequency remains moderate, this spectral shape shows little change. Therefore, the quantum control allows shifting the absorption peak to a desired position, and locks the absorption peak to the carrier frequency of the driving pulses. Detailed description of the spectrum, and its evolution as a function time, the inter-pulse spacing and the detuning, is presented.« less

  7. Pulse-excited, auto-zeroing multiple channel data transmission system

    DOEpatents

    Fasching, G.E.

    1985-02-22

    A multiple channel data transmission system is provided in which signals from a plurality of pulse operated transducers and a corresponding plurality of pulse operated signal processor channels are multiplexed for single channel FM transmission to a receiving station. The transducers and corresponding channel amplifiers are powered by pulsing the dc battery power to these devices to conserve energy and battery size for long-term data transmission from remote or inaccessible locations. Auto zeroing of the signal channel amplifiers to compensate for drift associated with temperature changes, battery decay, component aging, etc., in each channel is accomplished by means of a unique auto zero feature which between signal pulses holds a zero correction voltage on an integrating capacitor coupled to the corresponding channel amplifier output. Pseudo-continuous outputs for each channel are achieved by pulsed sample-and-hold circuits which are updated at the pulsed operation rate. The sample-and-hold outputs are multiplexed into an FM/FM transmitter for transmission to an FM receiver station for demultiplexing and storage in separate channel recorders.

  8. Pulse-excited, auto-zeroing multiple channel data transmission system

    DOEpatents

    Fasching, George E.

    1987-01-01

    A multiple channel data transmission system is provided in which signals from a plurality of pulse operated transducers and a corresponding plurality of pulse operated signal processor channels are multiplexed for single channel FM transmission to a receiving station. The transducers and corresponding channel amplifiers are powered by pulsing the dc battery power to these devices to conserve energy and battery size for long-term data transmission from remote or inaccessible locations. Auto zeroing of the signal channel amplifiers to compensate for drift associated with temperature changes, battery decay, component aging, etc., in each channel is accomplished by means of a unique auto zero feature which between signal pulses holds a zero correction voltage on an integrating capacitor coupled to the corresponding channel amplifier output. Pseudo-continuous outputs for each channel are achieved by pulsed sample-and-hold circuits which are updated at the pulsed operation rate. The sample-and-hold outputs are multiplexed into an FM/FM transmitter for transmission to an FM receiver station for demultiplexing and storage in separate channel recorders.

  9. Ultrashort pulse high repetition rate laser system for biological tissue processing

    DOEpatents

    Neev, J.; Da Silva, L.B.; Matthews, D.L.; Glinsky, M.E.; Stuart, B.C.; Perry, M.D.; Feit, M.D.; Rubenchik, A.M.

    1998-02-24

    A method and apparatus are disclosed for fast, efficient, precise and damage-free biological tissue removal using an ultrashort pulse duration laser system operating at high pulse repetition rates. The duration of each laser pulse is on the order of about 1 fs to less than 50 ps such that energy deposition is localized in a small depth and occurs before significant hydrodynamic motion and thermal conduction, leading to collateral damage, can take place. The depth of material removed per pulse is on the order of about 1 micrometer, and the minimal thermal and mechanical effects associated with this ablation method allows for high repetition rate operation, in the region 10 to over 1000 Hertz, which, in turn, achieves high material removal rates. The input laser energy per ablated volume of tissue is small, and the energy density required to ablate material decreases with decreasing pulse width. The ablation threshold and ablation rate are only weakly dependent on tissue type and condition, allowing for maximum flexibility of use in various biological tissue removal applications. The use of a chirped-pulse amplified Titanium-doped sapphire laser is disclosed as the source in one embodiment. 8 figs.

  10. Absorption spectrum of a two-level system subjected to a periodic pulse sequence

    NASA Astrophysics Data System (ADS)

    Fotso, H. F.; Dobrovitski, V. V.

    2017-06-01

    We investigate how the quantum control of a two-level system (TLS) coupled to photons can modify and tune the TLS's photon absorption spectrum. Tuning and controlling the emission and the absorption are of great interest, e.g., for the development of efficient interfaces between stationary and flying qubits in modern architectures for quantum computation and quantum communication. We consider periodic pulse control, where the TLS is subjected to a periodic sequence of the near-resonant Rabi driving pulses, each pulse implementing a 180∘ rotation. For small interpulse delays, the absorption spectrum features a pronounced peak of stimulated emission at the pulse frequency, similar satellite peaks with smaller spectral weights, and the net absorption peaks on the sides. As long as the detuning between the carrier frequency of the driving and the TLS transition frequency remains moderate, this spectral shape shows little change. Therefore, the pulse control allows shifting the absorption peak to a desired position and locks the overall absorption spectrum to the carrier frequency of the driving pulses. A detailed description of the spectrum and its evolution as a function time, the interpulse spacing, and the detuning is presented.

  11. Ultrashort pulse high repetition rate laser system for biological tissue processing

    DOEpatents

    Neev, Joseph; Da Silva, Luiz B.; Matthews, Dennis L.; Glinsky, Michael E.; Stuart, Brent C.; Perry, Michael D.; Feit, Michael D.; Rubenchik, Alexander M.

    1998-01-01

    A method and apparatus is disclosed for fast, efficient, precise and damage-free biological tissue removal using an ultrashort pulse duration laser system operating at high pulse repetition rates. The duration of each laser pulse is on the order of about 1 fs to less than 50 ps such that energy deposition is localized in a small depth and occurs before significant hydrodynamic motion and thermal conduction, leading to collateral damage, can take place. The depth of material removed per pulse is on the order of about 1 micrometer, and the minimal thermal and mechanical effects associated with this ablation method allows for high repetition rate operation, in the region 10 to over 1000 Hertz, which, in turn, achieves high material removal rates. The input laser energy per ablated volume of tissue is small, and the energy density required to ablate material decreases with decreasing pulse width. The ablation threshold and ablation rate are only weakly dependent on tissue type and condition, allowing for maximum flexibility of use in various biological tissue removal applications. The use of a chirped-pulse amplified Titanium-doped sapphire laser is disclosed as the source in one embodiment.

  12. Relativistic laser pulse focusing and self-compression in stratified plasma-vacuum systems

    SciTech Connect

    Karle, Ch.; Spatschek, K. H.

    2008-12-15

    Laser pulse compression in plasma-vacuum systems is investigated in the weakly relativistic regime. First, within one-dimensional hydrodynamic models, the basic features of propagation in plasmas, like width and amplitude changes, are demonstrated. The numerical findings can be interpreted, in part, a by simplified model based on the variation of action method. Since transverse effects like filamentation do play a significant role, the numerical evaluations are then generalized to two-dimensional situations. An approximate analytical criterion for the dominating transverse wave number during laser propagation in plasmas is presented. Finite plasma-vacuum systems show in addition to the filamentation instability the so-called plasma lens effect. The latter is first demonstrated for a single plasma layer. It is then discussed how (i) longitudinal and transversal self-compression in plasmas, (ii) focusing by a plasma layer, and (iii) cleaning of unstable modes compete with each other in layered plasma-vacuum systems. Depending on the available parameters, optimized plasma-vacuum systems are proposed for pulse compression. Such systems can be used as a substitute for hollow fibers which are in use to shorten a pulse. Pulse lengths of one or two cycles can be reached by optimized plasma-vacuum systems, while attaining ultrarelativistic intensities in the focal spot behind the system of layers.

  13. Intelligent pulse light source in the performance calibration system of two-dimensional neutron detector

    NASA Astrophysics Data System (ADS)

    Yang, Lei; Zhao, Xiao-Fang

    2017-07-01

    Chinese Spallation Neutron Source (CSNS) project will use numerous two-dimensional (2D) neutron detectors whose ZnS (Ag) scintillator is doped with 6Li. To ensure the consistency of all neutron detectors, a calibration system for the performance of 2D neutron detectors is designed. For radiation protection, the state control of the radiation source gets more and more strict. It is impossible to directly carry out experiments with massive radioactive particles. Thus, the following scheme has been designed. The controlled pulsed laser light source on a 2D mobile platform is used to replace the neutron bombardment to generate the photon. The pulse signal drives the laser diode to generate pulse light. The pulse light source located on the 2D platform is controlled by the core controller, and goes to the wavelength shift fiber through the optical fiber. The host computer (PC) receives the signal from the electronics system, processes data, and automatically calibrates the performance parameters. As shown by the experimental results, the pulse light source can perfectly meet all requirements of 2D neutron detector calibration system.

  14. Demonstration and Optimization of BNFL's Pulsed Jet Mixing and RFD Sampling Systems Using NCAW Simulant

    SciTech Connect

    JR Bontha; GR Golcar; N Hannigan

    2000-08-29

    The BNFL Inc. flowsheet for the pretreatment and vitrification of the Hanford High Level Tank waste includes the use of several hundred Reverse Flow Diverters (RFDs) for sampling and transferring the radioactive slurries and Pulsed Jet mixers to homogenize or suspend the tank contents. The Pulsed Jet mixing and the RFD sampling devices represent very simple and efficient methods to mix and sample slurries, respectively, using compressed air to achieve the desired operation. The equipment has no moving parts, which makes them very suitable for mixing and sampling highly radioactive wastes. However, the effectiveness of the mixing and sampling systems are yet to be demonstrated when dealing with Hanford slurries, which exhibit a wide range of physical and theological properties. This report describes the results of the testing of BNFL's Pulsed Jet mixing and RFD sampling systems in a 13-ft ID and 15-ft height dish-bottomed tank at Battelle's 336 building high-bay facility using AZ-101/102 simulants containing up to 36-wt% insoluble solids. The specific objectives of the work were to: Demonstrate the effectiveness of the Pulsed Jet mixing system to thoroughly homogenize Hanford-type slurries over a range of solids loading; Minimize/optimize air usage by changing sequencing of the Pulsed Jet mixers or by altering cycle times; and Demonstrate that the RFD sampler can obtain representative samples of the slurry up to the maximum RPP-WTP baseline concentration of 25-wt%.

  15. Using random proportional pulse feedback of system variables to control chaos and hyperchaos

    NASA Astrophysics Data System (ADS)

    Luo, Xiao-shu; Wang, Bing-hong; Jiang, Feng; Gao, Yuan

    2001-01-01

    A method that allows one to control chaotic and hyperchaotic systems by a random proportional pulse feedback of system variables is proposed. This method is illustrated with the Rossler chaotic and the complex Lorenz-Harken hyperchaotic systems and a better control result is obtained. The advantage of this method is that just one perturbed system variable is enough to obtain a stabilized periodic orbit.

  16. Pulse Code Modulation (PCM) encoder handbook for Aydin Vector MMP-900 series system

    NASA Astrophysics Data System (ADS)

    Raphael, David

    1995-06-01

    This handbook explicates the hardware and software properties of a time division multiplex system. This system is used to sample analog and digital data. The data is then merged with frame synchronization information to produce a serial pulse coded modulation (PCM) bit stream. Information in this handbook is required by users to design congruous interface and attest effective utilization of this encoder system. Aydin Vector provides all of the components for these systems to Goddard Space Flight Center/Wallops Flight Facility.

  17. Pulse Code Modulation (PCM) encoder handbook for Aydin Vector MMP-900 series system

    NASA Technical Reports Server (NTRS)

    Raphael, David

    1995-01-01

    This handbook explicates the hardware and software properties of a time division multiplex system. This system is used to sample analog and digital data. The data is then merged with frame synchronization information to produce a serial pulse coded modulation (PCM) bit stream. Information in this handbook is required by users to design congruous interface and attest effective utilization of this encoder system. Aydin Vector provides all of the components for these systems to Goddard Space Flight Center/Wallops Flight Facility.

  18. Measurement of lake ice thickness with a short-pulse radar system

    NASA Technical Reports Server (NTRS)

    Cooper, D. W.; Mueller, R. A.; Schertler, R. J.

    1976-01-01

    Measurements of lake ice thickness were made during March 1975 at the Straits of Mackinac by using a short-pulse radar system aboard an all-terrain vehicle. These measurements were compared with ice thicknesses determined with an auger. Over 25 sites were explored which had ice thicknesses in the range 29 to 60 cm. The maximum difference between radar and auger measurements was less than 9.8 percent. The magnitude of the error was less than + or - 3.5 cm. The NASA operating short-pulse radar system used in monitoring lake ice thickness from an aircraft is also described.

  19. Pulsed fluorescent x-ray system with on-line digitizer and data processor

    SciTech Connect

    Berzins, G.J.; Valencia, J.E.; Gutierrez, J.W.; McGirt, F.; Moore, K.R.

    1984-12-01

    A pulsed source of monoenergetic x rays has been constructed for applications in which a narrow energy band and a short burst are both important. The radiation source is a high-purity, selectable foil that emits fluorescent x rays upon excitation by a bremsstrahlung pulse. A digitizer and a microcomputer are integrated into the system to aid operation and data processing. A general description, the more important system characteristics, and a few examples of applications are given. 7 references, 10 figures, 6 tables.

  20. Sequence alignment with tandem duplication

    SciTech Connect

    Benson, G.

    1997-12-01

    Algorithm development for comparing and aligning biological sequences has, until recently, been based on the SI model of mutational events which assumes that modification of sequences proceeds through any of the operations of substitution, insertion or deletion (the latter two collectively termed indels). While this model has worked farily well, it has long been apparent that other mutational events occur. In this paper, we introduce a new model, the DSI model which includes another common mutational event, tandem duplication. Tandem duplication produces tandem repeats which are common in DNA, making up perhaps 10% of the human genome. They are responsible for some human diseases and may serve a multitude of functions in DNA regulation and evolution. Using the DSI model, we develop new exact and heuristic algorithms for comparing and aligning DNA sequences when they contain tandem repeats. 30 refs., 3 figs.

  1. Generation of intense femtosecond optical vortex pulses with blazed-phase grating in chirped-pulse amplification system of Ti:sapphire laser

    NASA Astrophysics Data System (ADS)

    Lin, Yu-Chieh; Nabekawa, Yasuo; Midorikawa, Katsumi

    2016-11-01

    We demonstrate the generation of an intense femtosecond optical vortex (OV) pulse by employing an OV converter set between two laser amplifiers in a chirped-pulse amplification (CPA) system of a Ti:sapphire laser. The OV converter is composed of a liquid-crystal spatial light modulator (LC-SLM) exhibiting a blazed-phase computer-generated hologram, a concave mirror, and a flat mirror in the 4f setup. Owing to the intrinsic nature of the 4f setup, the OV converter is free from chromatic and topological-charge dispersions, which are always induced in a spiral phase plate conventionally used to convert an intense Gaussian laser pulse to an OV pulse, while we can avoid damage to the LC-SLM by the irradiation of a low-energy pulse before the second amplifier. We have increased the throughput of the OV converter to 42% by systematically investigating the diffraction efficiency of the blazed-phase hologram on the LC-SLM, which relaxes the gain condition required for the second amplifier. The combination of the high-throughput OV converter and the two-stage amplification enables us to generate OV pulses with an energy of 1.63 mJ and a pulse duration of 60 fs at a wavelength of 720 nm, at which the gain of the Ti:sapphire laser is only 60% of the peak gain around 800 nm.

  2. High speed photoacoustic tomography system with low cost portable pulsed diode laser

    NASA Astrophysics Data System (ADS)

    Upputuri, Paul Kumar; Sivasubramanian, Kathyayini; Pramanik, Manojit

    2015-07-01

    Photoacoustic tomography (PAT) is a potential hybrid imaging modality that has attracted great attention in the fields of medical imaging. In order to generate photoacoustic signal efficiently Q-switched Nd:YAG pump lasers capable of generating tens of millijoules of nanosecond laser pulses have been widely used. However, PAT systems using such lasers have limitations in clinical applications because of their high cost, large size, and cooling requirements. Furthermore, the low pulse repetition rate (PRR) of tens of hertz is not suitable for real-time PAT. So, there is a need for inexpensive, compact, simple, fast imaging system for clinical applications. Nanosecond pulsed laser diodes could meet these requirements. In this work, we present a high-speed photoacoustic tomography imaging system that uses a compact and yet relatively powerful near-infrared pulsed laser diode. The PAT system was tested on phantoms to verify its potential imaging speed. Photoacoustic reconstructed images at different scanning speeds are presented. With single ultrasound detector scanning, the system could provide PA image ~10 times faster than the Nd:YAG laser based systems.

  3. Characterization and optimization of an eight-channel time-multiplexed pulse-shaping system

    SciTech Connect

    Dorrer, Christophe; Bittle, Wade A.; Cuffney, Robert; Spilatro, Michael; Hill, Elizabeth M.; Kosc, Tanya Z.; Kelly, John H.; Zuegel, Jonathan D.

    2016-12-06

    High-performance optical pulse shaping is paramount to photonics and lasers applications for which high-resolution optical waveforms must be generated. We investigate the design and performance of a time-multiplexed pulse shaping (TMPS) system in which optical waveforms from a single pulse-shaping unit are demultiplexed and retimed before being sent to different optical systems. This architecture has the advantages of low cost and low relative jitter between optical waveforms because a single pulse-shaping system, e.g., a high-performance arbitrary waveform generator driving a Mach-Zehnder modulator, generates all the waveforms. We demonstrate an eight-channel TMPS system based on a 1 × 8 LiNbO3 demultiplexer composed of four stages of 1 × 2 Δβ phase-reversal switches that allow for demultiplexing and extinction enhancement via application of a control voltage modifying the propagation constant difference between adjacent waveguides. It is shown that optimal demultiplexing, i.e. low insertion loss and high extinction ratio between channels, requires optimization in dynamic operation because of the slow component of the switches’ response. Lastly, we demonstrate losses lower than 5 dB, extinction ratios of the order of 70 dB for a four-channel system and 50 dB for an eight-channel system, and jitter added by the demultiplexer smaller than 0.1 ps.

  4. Characterization and optimization of an eight-channel time-multiplexed pulse-shaping system

    DOE PAGES

    Dorrer, Christophe; Bittle, Wade A.; Cuffney, Robert; ...

    2016-12-06

    High-performance optical pulse shaping is paramount to photonics and lasers applications for which high-resolution optical waveforms must be generated. We investigate the design and performance of a time-multiplexed pulse shaping (TMPS) system in which optical waveforms from a single pulse-shaping unit are demultiplexed and retimed before being sent to different optical systems. This architecture has the advantages of low cost and low relative jitter between optical waveforms because a single pulse-shaping system, e.g., a high-performance arbitrary waveform generator driving a Mach-Zehnder modulator, generates all the waveforms. We demonstrate an eight-channel TMPS system based on a 1 × 8 LiNbO3 demultiplexermore » composed of four stages of 1 × 2 Δβ phase-reversal switches that allow for demultiplexing and extinction enhancement via application of a control voltage modifying the propagation constant difference between adjacent waveguides. It is shown that optimal demultiplexing, i.e. low insertion loss and high extinction ratio between channels, requires optimization in dynamic operation because of the slow component of the switches’ response. Lastly, we demonstrate losses lower than 5 dB, extinction ratios of the order of 70 dB for a four-channel system and 50 dB for an eight-channel system, and jitter added by the demultiplexer smaller than 0.1 ps.« less

  5. Enzyme evolution beyond gene duplication

    PubMed Central

    Noda-García, Lianet; Barona-Gómez, Francisco

    2013-01-01

    Understanding the evolution of enzyme function after gene duplication has been a major goal of molecular biologists, biochemists and evolutionary biologists alike, for almost half a century. In contrast, the impact that horizontal gene transfer (HGT) has had on the evolution of enzyme specialization and the assembly of metabolic networks has just started to being investigated. Traditionally, evolutionary studies of enzymes have been limited to either the function of enzymes in vitro, or to sequence variability at the population level, where in almost all cases the starting conceptual framework embraces gene duplication as the mechanism responsible for the appearance of genetic redundancy. Very recently, we merged comparative phylogenomics, detection of selection signals, enzyme kinetics, X-ray crystallography and computational molecular dynamics, to characterize the sub-functionalization process of an amino acid biosynthetic enzyme prompted by an episode of HGT in bacteria. Some of the evolutionary implications of these functional studies, including a proposed model of enzyme specialization independent of gene duplication, are developed in this commentary. PMID:24251070

  6. Thumb Duplication: Concepts and Techniques

    PubMed Central

    2012-01-01

    Within the Oberg, Manske, Tonkin (OMT) classification, thumb duplications are a failure of formation and/or differentiation affecting the radial-ulnar axis of the hand plate. The Wassel description of seven types of thumb duplication provides a good structure from which an approach to management is based. The aim of surgical reconstruction is to obtain a stable, mobile thumb of adequate size and appropriate shape. The most common form of reconstruction is removal of the lesser digit and reconstruction of the dominant digit. Surgical techniques address the problems of deviation, instability and lack of size. The disadvantages of the Bilhaut-Cloquet procedure, these being joint stiffness and a nail ridge, may be lesser concerns when reconstruction of one digit will not create a satisfactory thumb of adequate mobility, stability, alignment and size. Complicated problems of triphalangism, triplication, ulnar dimelia and the rare circumstance in which neither of the duplicated thumbs may be adequately reconstructed present specific challenges which demand alternative techniques. PMID:22379552

  7. Application of P4 Polyphase codes pulse compression method to air-coupled ultrasonic testing systems.

    PubMed

    Li, Honggang; Zhou, Zhenggan

    2017-07-01

    Air-coupled ultrasonic testing systems are usually restricted by low signal-to-noise ratios (SNR). The use of pulse compression techniques based on P4 Polyphase codes can improve the ultrasound SNR. This type of codes can generate higher Peak Side Lobe (PSL) ratio and lower noise of compressed signal. This paper proposes the use of P4 Polyphase sequences to code ultrasound with a NDT system based on air-coupled piezoelectric transducer. Furthermore, the principle of selecting parameters of P4 Polyphase sequence for obtaining optimal pulse compression effect is also studied. Successful results are presented in molded composite material. A hybrid signal processing method for improvement in SNR up to 12.11dB and in time domain resolution about 35% are achieved when compared with conventional pulse compression technique. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. ELI-Beamlines: development of next generation short-pulse laser systems

    NASA Astrophysics Data System (ADS)

    Rus, B.; Bakule, P.; Kramer, D.; Naylon, J.; Thoma, J.; Green, J. T.; Antipenkov, R.; Fibrich, M.; Novák, J.; Batysta, F.; Mazanec, T.; Drouin, M. A.; Kasl, K.; Baše, R.; Peceli, D.; Koubíková, L.; Trojek, P.; Boge, R.; Lagron, J. C.; Vyhlídka, Å.; Weiss, J.; Cupal, J.,; Hřebíček, J.; Hříbek, P.; Durák, M.; Polan, J.; Košelja, M.; Korn, G.; Horáček, M.; Horáček, J.; Himmel, B.; Havlíček, T.; Honsa, A.; Korouš, P.; Laub, M.; Haefner, C.; Bayramian, A.; Spinka, T.; Marshall, C.; Johnson, G.; Telford, S.; Horner, J.; Deri, B.; Metzger, T.; Schultze, M.; Mason, P.; Ertel, K.; Lintern, A.; Greenhalgh, J.; Edwards, C.; Hernandez-Gomez, C.; Collier, J.; Ditmire, T.,; Gaul, E.; Martinez, M.; Frederickson, C.; Hammond, D.; Malato, C.; White, W.; Houžvička, J.

    2015-05-01

    Overview of the laser systems being built for ELI-Beamlines is presented. The facility will make available high-brightness multi-TW ultrashort laser pulses at kHz repetition rate, PW 10 Hz repetition rate pulses, and kilojoule nanosecond pulses for generation of 10 PW peak power. The lasers will extensively employ the emerging technology of diode-pumped solid-state lasers (DPSSL) to pump OPCPA and Ti:sapphire broadband amplifiers. These systems will provide the user community with cutting-edge laser resources for programmatic research in generation and applications of high-intensity X-ray sources, in particle acceleration, and in dense-plasma and high-field physics.

  9. Pulse radiolysis system of OPU-LINAC in RIAST, Osaka Prefecture University

    NASA Astrophysics Data System (ADS)

    Kojima, Takao; Taniguchi, Ryoichi; Furuta, Masakazu; Okuda, Shuichi; Hara, Masayuki; Fujita, Shin'ichi

    2004-09-01

    Micro- to milli-second pulse radiolysis apparatus using short electron pulse form 18 MeV linear accelerator (Linac) is in-service at the Research institute for advanced science and technology (RIAST), Osaka Prefecture University. This apparatus is an effective tool, not only for investigation of primary process on radiation chemistry, but also for research of electron transfer mechanism playing an important role in chemistry and bioscience. This apparatus is composed of an 18 MeV electron linear accelerator (electron pulse duration: about 4 μs) and a transient light absorption measurement system. We introduce the outline of this system, transient absorption spectrum of thiocyanate aqueous solution as an example of measured data and future plan.

  10. A Pulse Power Modulator System for Commercial High Power Ion Beam Surface Treatment Applications

    SciTech Connect

    Barrett, D.M.; Cockreham, B.D.; Dragt, A.J.; Ives, H.C.; Neau, E.L.; Reed, K.W.; White, F.E.

    1999-05-24

    The Ion Beam Surface Treatment (lBESTrM) process utilizes high energy pulsed ion beams to deposit energy onto the surface of a material allowing near instantaneous melting of the surface layer. The melted layer typically re-solidifies at a very rapid rate which forms a homogeneous, fine- grained structure on the surface of the material resulting in significantly improved surface characteristics. In order to commercialize the IBESTTM process, a reliable and easy-to-operate modulator system has been developed. The QM-I modulator is a thyratron-switched five-stage magnetic pulse compression network which drives a two-stage linear induction adder. The adder provides 400 kV, 150 ns FWHM pulses at a maximum repetition rate of 10 pps for the acceleration of the ion beam. Special emphasis has been placed upon developing the modulator system to be consistent with long-life commercial service.

  11. Limitations of power conversion systems under transient loads and impact on the pulsed tokamak power reactor

    NASA Astrophysics Data System (ADS)

    Sager, G. T.; Wong, C. P. C.; Kapich, D. D.; McDonald, C. F.; Schleicher, R. W.

    1993-11-01

    The impact of cyclic loading of the power conversion system of a helium-cooled, pulsed tokamak power plant is assessed. Design limits of key components of heat transport systems employing Rankine and Brayton thermodynamic cycles are quantified based on experience in gas-cooled fission reactor design and operation. Cyclic loads due to pulsed tokamak operation are estimated. Expected performance of the steam generator is shown to be incompatible with pulsed tokamak operation without load leveling thermal energy storage. The close cycle gas turbine is evaluated qualitatively based on performance of existing industrial and aeroderivative gas turbines. Advances in key technologies which significantly improve prospects for operation with tokamak fusion plants are reviewed.

  12. A low-power high-speed ultra-wideband pulse radio transmission system.

    PubMed

    Wei Tang; Culurciello, E

    2009-10-01

    We present a low-power high-speed ultra-wideband (UWB) transmitter with a wireless transmission test platform. The system is specifically designed for low-power high-speed wireless implantable biosensors. The integrated transmitter consists of a compact pulse generator and a modulator. The circuit is fabricated in the 0.5-mum silicon-on-sapphire process and occupies 420 mum times 420 mum silicon area. The transmitter is capable of generating pulses with 1-ns width and the pulse rate can be controlled between 90 MHz and 270 MHz. We built a demonstration/testing system for the transmitter. The transmitter achieves a 14-Mb/s data rate. With 50% duty cycle data, the power consumption of the chip is between 10 mW and 21 mW when the transmission distance is from 3.2 to 4 m. The core circuit size is 70 mum times 130 mum.

  13. Limitations of power conversion systems under transient loads and impact on the pulsed tokamak power reactor

    SciTech Connect

    Sager, G.T.; Wong, C.P.C.; Kapich, D.D.; McDonald, C.F.; Schleicher, R.W.

    1993-11-01

    The impact of cyclic loading of the power conversion system of a helium-cooled, pulsed tokamak power plant is assessed. Design limits of key components of heat transport systems employing Rankie and Brayton thermodynamic cycles are quantified based on experience in gas-cooled fission reactor design and operation. Cyclic loads due to pulsed tokamak operation are estimated. Expected performance of the steam generator is shown to be incompatible with pulsed tokamak operation without load leveling thermal energy storage. The close cycle gas turbine is evaluated qualitatively based on performance of existing industrial and aeroderivative gas turbines. Advances in key technologies which significantly improve prospects for operation with tokamak fusion plants are reviewed.

  14. Initial operation of high power ICRF system for long pulse in EAST

    SciTech Connect

    Qin, C. M. Zhao, Y. P.; Zhang, X. J.; Wan, B. N.; Gong, X. Z.; Mao, Y. Z.; Yuan, S.; Chen, G.

    2015-12-10

    The ICRF heating system on EAST upgraded by active cooling aims for long pulse operation. In this paper, the main technical features of the ICRF system are described. One of a major challenges for long pulse operation is RF-edge interactions induced impurity production and heat loading. In EAST, ICRF antenna protections and Faraday screen bars damaged due to LH electron beam are found. Preliminary results for the analysis of the interaction between LHCD and ICRF antenna are discussed. Increase of metal impurities in the plasma during RF pulse and in a larger core radiation are also shown. These RF-edge interactions at EAST and some preliminary results for the optimizing RF performance will be presented.

  15. Initial operation of high power ICRF system for long pulse in EAST

    NASA Astrophysics Data System (ADS)

    Qin, C. M.; Zhao, Y. P.; Zhang, X. J.; Wan, B. N.; Gong, X. Z.; Mao, Y. Z.; Yuan, S.; Chen, G.

    2015-12-01

    The ICRF heating system on EAST upgraded by active cooling aims for long pulse operation. In this paper, the main technical features of the ICRF system are described. One of a major challenges for long pulse operation is RF-edge interactions induced impurity production and heat loading. In EAST, ICRF antenna protections and Faraday screen bars damaged due to LH electron beam are found. Preliminary results for the analysis of the interaction between LHCD and ICRF antenna are discussed. Increase of metal impurities in the plasma during RF pulse and in a larger core radiation are also shown. These RF-edge interactions at EAST and some preliminary results for the optimizing RF performance will be presented.

  16. Yb:YAG Innoslab amplifier: efficient high repetition rate subpicosecond pumping system for optical parametric chirped pulse amplification.

    PubMed

    Schulz, M; Riedel, R; Willner, A; Mans, T; Schnitzler, C; Russbueldt, P; Dolkemeyer, J; Seise, E; Gottschall, T; Hädrich, S; Duesterer, S; Schlarb, H; Feldhaus, J; Limpert, J; Faatz, B; Tünnermann, A; Rossbach, J; Drescher, M; Tavella, F

    2011-07-01

    We report on a Yb:YAG Innoslab laser amplifier system for generation of subpicsecond high energy pump pulses for optical parametric chirped pulse amplification (OPCPA) at high repetition rates. Pulse energies of up to 20 mJ (at 12.5 kHz) and repetition rates of up to 100 kHz were attained with pulse durations of 830 fs and average power in excess of 200 W. We further investigate the possibility to use subpicosecond pulses to derive a stable continuum in a YAG crystal for OPCPA seeding.

  17. Steady-State Indicator of Intracranial Pressure Dynamic System using Geodesic Distance of ICP Pulse Waveform

    PubMed Central

    Hu, Xiao; Gonzalez, Nestor; Bergsneider, Marvin

    2013-01-01

    Normal functioning of the brain depends on the homeostasis (~ steady state) of its various physiological sub-systems, one of which is the intracranial pressure (ICP) dynamic system. ICP dynamic system of an injured brain is susceptible to various acute changes that should ideally be detected by ICP monitoring even for comatose patients. However, the status quo of ICP monitoring solely targets mean ICP. We aimed to demonstrate a novel approach to detect acute deviation from steady state of an ICP dynamic system in an absence of significant mean ICP changes. We hypothesized that steady state of ICP dynamic systems is reflected as ICP pulses of similar mean ICP levels resembling each other. A general framework was used to derive such a steady-state indicator that can accommodate different metrics of inter-pulse distance and different statistics of the distance histograms. In addition to conventional Euclidean distance and Pearson correlation, geodesic distance between pulses was introduced as a novel metric. These different ways of calculating steady-state indicators under the proposed framework were evaluated on three types of continuous ICP recordings: 1) those between two consecutive brain imaging studies that demonstrated acute ventricular enlargement for slit ventricle syndrome (SVS) patients undergoing a trial of shunt externalization and clamping (SVS+); 2) those between consecutive brain imaging studies from the SVS patients under the same trial but without ventricular enlargement (SVS−); 3) overnight recordings from patients with suspected normal pressure hydrocephalus (NPH). It was observed that only the standard deviation of geodesic distance correctly differentiated between SVS+ and SVS− and between SVS+ and NPH while avoiding discriminating between SVS− and NPH. It was also found that 45% SVS+ cases had a multimodal geodesic distance histogram while none of SVS− and 3.8% of NPH cases had such a multimodal histogram. Pulses with a large number of

  18. Pulsed Yb:fiber system capable of >250kW peak power with tunable pulses in the 50ps to 1.5ns range

    NASA Astrophysics Data System (ADS)

    McComb, Timothy S.; Lowder, Tyson L.; Leadbetter, Vickie; Reynolds, Mitch; Saracco, Matthieu J.; Hutchinson, Joel; Green, Jared; McCal, Dennis; Burkholder, Gary; Kutscha, Tim; Dittli, Adam; Hamilton, Chuck; Kliner, Dahv A. V.; Randall, Matthew; Fanning, Geoff; Bell, Jake

    2013-03-01

    We have demonstrated a pulsed 1064 nm PM Yb:fiber laser system incorporating a seed source with a tunable pulse repetition rate and pulse duration and a multistage fiber amplifier, ending in a large core (>650 μm2 mode field area), tapered fiber amplifier. The amplifier chain is all-fiber, with the exception of the final amplifier's pump combiner, allowing robust, compact packaging. The air-cooled laser system is rated for >60 W of average power and beam quality of M2 < 1.3 at repetition rates below 100 kHz to 10's of MHz, with pulses discretely tunable over a range spanning 50 ps to greater than 1.5 ns. Maximum pulse energies, limited by the onset of self phase modulation and stimulated Raman scattering, are greater than 12.5 μJ at 50 ps and 375 μJ at 1.5 ns , corresponding to >250 kW peak power across the pulse tuning range. We present frequency conversion to 532 nm with efficiency greater than 70% and conversion to UV via frequency tripling, with initial feasibility experiments showing >30% UV conversion efficiency. Application results of the laser in scribing, thin film removal and micro-machining will be discussed.

  19. Various methods of optimizing control pulses for quantum systems with decoherence

    NASA Astrophysics Data System (ADS)

    Pawela, Łukasz; Sadowski, Przemysław

    2016-05-01

    We design control setting that allows the implementation of an approximation of an unitary operation of a quantum system under decoherence using various quantum system layouts and numerical algorithms. We focus our attention on the possibility of adding ancillary qubits which help to achieve a desired quantum map on the initial system. Furthermore, we use three methods of optimizing the control pulses: genetic optimization, approximate evolution method and approximate gradient method. To model the noise in the system we use the Lindblad equation. We obtain results showing that applying the control pulses to the ancilla allows one to successfully implement unitary operation on a target system in the presence of noise, which is not possible which control field applied to the system qubits.

  20. Optimization of hybrid power system composed of SMES and flywheel MG for large pulsed load

    NASA Astrophysics Data System (ADS)

    Niiyama, K.; Yagai, T.; Tsuda, M.; Hamajima, T.

    2008-09-01

    A superconducting magnetic storage system (SMES) has some advantages such as rapid large power response and high storage efficiency which are superior to other energy storage systems. A flywheel motor generator (FWMG) has large scaled capacity and high reliability, and hence is broadly utilized for a large pulsed load, while it has comparatively low storage efficiency due to high mechanical loss compared with SMES. A fusion power plant such as International Thermo-Nuclear Experimental Reactor (ITER) requires a large and long pulsed load which causes a frequency deviation in a utility power system. In order to keep the frequency within an allowable deviation, we propose a hybrid power system for the pulsed load, which equips the SMES and the FWMG with the utility power system. We evaluate installation cost and frequency control performance of three power systems combined with energy storage devices; (i) SMES with the utility power, (ii) FWMG with the utility power, (iii) both SMES and FWMG with the utility power. The first power system has excellent frequency power control performance but its installation cost is high. The second system has inferior frequency control performance but its installation cost is the lowest. The third system has good frequency control performance and its installation cost is attained lower than the first power system by adjusting the ratio between SMES and FWMG.

  1. Chromosome I Duplications in Caenorhabditis Elegans

    PubMed Central

    McKim, K. S.; Rose, A. M.

    1990-01-01

    We have isolated and characterized 76 duplications of chromosome I in the genome of Caenorhabditis elegans. The region studied is the 20 map unit left half of the chromosome. Sixty-two duplications were induced with gamma radiation and 14 arose spontaneously. The latter class was apparently the result of spontaneous breaks within the parental duplication. The majority of duplications behave as if they are free. Three duplications are attached to identifiable sequences from other chromosomes. The duplication breakpoints have been mapped by complementation analysis relative to genes on chromosome I. Nineteen duplication breakpoints and seven deficiency breakpoints divide the left half of the chromosome into 24 regions. We have studied the relationship between duplication size and segregational stability. While size is an important determinant of mitotic stability, it is not the only one. We observed clear exceptions to a size-stability correlation. In addition to size, duplication stability may be influenced by specific sequences or chromosome structure. The majority of the duplications were stable enough to be powerful tools for gene mapping. Therefore the duplications described here will be useful in the genetic characterization of chromosome I and the techniques we have developed can be adapted to other regions of the genome. PMID:2307351

  2. Detecting long tandem duplications in genomic sequences

    PubMed Central

    2012-01-01

    Background Detecting duplication segments within completely sequenced genomes provides valuable information to address genome evolution and in particular the important question of the emergence of novel functions. The usual approach to gene duplication detection, based on all-pairs protein gene comparisons, provides only a restricted view of duplication. Results In this paper, we introduce ReD Tandem, a software using a flow based chaining algorithm targeted at detecting tandem duplication arrays of moderate to longer length regions, with possibly locally weak similarities, directly at the DNA level. On the A. thaliana genome, using a reference set of tandem duplicated genes built using TAIR,a we show that ReD Tandem is able to predict a large fraction of recently duplicated genes (dS < 1) and that it is also able to predict tandem duplications involving non coding elements such as pseudo-genes or RNA genes. Conclusions ReD Tandem allows to identify large tandem duplications without any annotation, leading to agnostic identification of tandem duplications. This approach nicely complements the usual protein gene based which ignores duplications involving non coding regions. It is however inherently restricted to relatively recent duplications. By recovering otherwise ignored events, ReD Tandem gives a more comprehensive view of existing evolutionary processes and may also allow to improve existing annotations. PMID:22568762

  3. Genomic evidence for adaptation by gene duplication.

    PubMed

    Qian, Wenfeng; Zhang, Jianzhi

    2014-08-01

    Gene duplication is widely believed to facilitate adaptation, but unambiguous evidence for this hypothesis has been found in only a small number of cases. Although gene duplication may increase the fitness of the involved organisms by doubling gene dosage or neofunctionalization, it may also result in a simple division of ancestral functions into daughter genes, which need not promote adaptation. Hence, the general validity of the adaptation by gene duplication hypothesis remains uncertain. Indeed, a genome-scale experiment found similar fitness effects of deleting pairs of duplicate genes and deleting individual singleton genes from the yeast genome, leading to the conclusion that duplication rarely results in adaptation. Here we contend that the above comparison is unfair because of a known duplication bias among genes with different fitness contributions. To rectify this problem, we compare homologous genes from the budding yeast Saccharomyces cerevisiae and the fission yeast Schizosaccharomyces pombe. We discover that simultaneously deleting a duplicate gene pair in S. cerevisiae reduces fitness significantly more than deleting their singleton counterpart in S. pombe, revealing post-duplication adaptation. The duplicates-singleton difference in fitness effect is not attributable to a potential increase in gene dose after duplication, suggesting that the adaptation is owing to neofunctionalization, which we find to be explicable by acquisitions of binary protein-protein interactions rather than gene expression changes. These results provide genomic evidence for the role of gene duplication in organismal adaptation and are important for understanding the genetic mechanisms of evolutionary innovation.

  4. JPL self pulsed laser surface measurement system development. [large space deployed antenna structures

    NASA Technical Reports Server (NTRS)

    Berdahl, M.

    1980-01-01

    The use of a self pulsed laser system for accurately describing the surface shape of large space deployed antenna structures was evaluated. Tests with a breadboard system verified functional operation with short time resolution on the order of .2 mm, nonambiguous ranging, and a maximum range capability on the order of 150 m. The projected capability of the system is resolution of less than .1 mm over a reasonable time period and a range extension to over 300 m.

  5. Methodology to assess the effects of magnetohydrodynamic electromagnetic pulse (MHD-EMP) on power systems

    SciTech Connect

    Legro, J.R.; Abi-Samra, N.C.; Crouse, J.C.; Tesche, F.M.

    1985-01-01

    This paper summarizes a method to evaluate the possible effects of magnetohydrodynamic-electromagnetic pulse (MHD-EMP) on power systems. This method is based on the approach adapted to study the impact of geomagnetic storms on power systems. The paper highlights the similarities and differences between the two phenomena. Also presented are areas of concern which are anticipated from MHD-EMP on the overall system operation. 12 refs., 1 fig.

  6. Tubular Colonic Duplication Presenting as Rectovestibular Fistula.

    PubMed

    Karkera, Parag J; Bendre, Pradnya; D'souza, Flavia; Ramchandra, Mukunda; Nage, Amol; Palse, Nitin

    2015-09-01

    Complete colonic duplication is a very rare congenital anomaly that may have different presentations according to its location and size. Complete colonic duplication can occur in about 15% of all gastrointestinal duplications. Double termination of tubular colonic duplication in the perineum is even more uncommon. We present a case of a Y-shaped tubular colonic duplication which presented with a rectovestibular fistula and a normal anus. Radiological evaluation and initial exploration for sigmoidostomy revealed duplicated colons with a common vascular supply. Endorectal mucosal resection of theduplicated distal segment till the colostomy site with division of the septum of the proximal segment and colostomy closure proved curative without compromise of the continence mechanism. Tubular colonic duplication should always be ruled out when a diagnosis of perineal canal is considered in cases of vestibular fistula alongwith a normal anus.

  7. Tubular Colonic Duplication Presenting as Rectovestibular Fistula

    PubMed Central

    Bendre, Pradnya; D'souza, Flavia; Ramchandra, Mukunda; Nage, Amol; Palse, Nitin

    2015-01-01

    Complete colonic duplication is a very rare congenital anomaly that may have different presentations according to its location and size. Complete colonic duplication can occur in about 15% of all gastrointestinal duplications. Double termination of tubular colonic duplication in the perineum is even more uncommon. We present a case of a Y-shaped tubular colonic duplication which presented with a rectovestibular fistula and a normal anus. Radiological evaluation and initial exploration for sigmoidostomy revealed duplicated colons with a common vascular supply. Endorectal mucosal resection of theduplicated distal segment till the colostomy site with division of the septum of the proximal segment and colostomy closure proved curative without compromise of the continence mechanism. Tubular colonic duplication should always be ruled out when a diagnosis of perineal canal is considered in cases of vestibular fistula alongwith a normal anus. PMID:26473141

  8. A nanosecond pulsed laser heating system for studying liquid and supercooled liquid films in ultrahigh vacuum

    NASA Astrophysics Data System (ADS)

    Xu, Yuntao; Dibble, Collin J.; Petrik, Nikolay G.; Smith, R. Scott; Joly, Alan G.; Tonkyn, Russell G.; Kay, Bruce D.; Kimmel, Greg A.

    2016-04-01

    A pulsed laser heating system has been developed that enables investigations of the dynamics and kinetics of nanoscale liquid films and liquid/solid interfaces on the nanosecond time scale in ultrahigh vacuum (UHV). Details of the design, implementation, and characterization of a nanosecond pulsed laser system for transiently heating nanoscale films are described. Nanosecond pulses from a Nd:YAG laser are used to rapidly heat thin films of adsorbed water or other volatile materials on a clean, well-characterized Pt(111) crystal in UHV. Heating rates of ˜1010 K/s for temperature increases of ˜100-200 K are obtained. Subsequent rapid cooling (˜5 × 109 K/s) quenches the film, permitting in-situ, post-heating analysis using a variety of surface science techniques. Lateral variations in the laser pulse energy are ˜±2.7% leading to a temperature uncertainty of ˜±4.4 K for a temperature jump of 200 K. Initial experiments with the apparatus demonstrate that crystalline ice films initially held at 90 K can be rapidly transformed into liquid water films with T > 273 K. No discernable recrystallization occurs during the rapid cooling back to cryogenic temperatures. In contrast, amorphous solid water films heated below the melting point rapidly crystallize. The nanosecond pulsed laser heating system can prepare nanoscale liquid and supercooled liquid films that persist for nanoseconds per heat pulse in an UHV environment, enabling experimental studies of a wide range of phenomena in liquids and at liquid/solid interfaces.

  9. Taking the pulse of a river system: first 20 years

    USGS Publications Warehouse

    Leake, Linda; Johnson, Barry

    2006-01-01

    Your doctor would not base decisions for your health care today on one physical examination when you were age three! You would reasonably expect decisions to be based on records from over your lifetime. Likewise, those responsible for monitoring the health of the Upper Mississippi River System want a more comprehensive way to diagnose problems and find treatment options. To begin developing a comprehensive view of the river, the five neighboring states of the Upper Mississippi River System and several Federal agencies formed a partnership in 1986 to monitor river conditions and long-term trends in the Upper Mississippi and Illinois Rivers.

  10. Acquisition System and Detector Interface for Power Pulsed Detectors

    NASA Astrophysics Data System (ADS)

    Cornat, Rémi; CALICE Colaboration

    A common DAQ system is being developed within the CALICE collaboration. It provides a flexible and scalable architecture based on giga-ethernet and 8b/10b serial links in order to transmit either slow control data, fast signals or read out data. A detector interface (DIF) is used to connect detectors to the DAQ system based on a single firmware shared among the collaboration but targeted on various physical implementations. The DIF allows to build, store and queue packets of data as well as to control the detectors providing USB and serial link connectivity. The overall architecture is foreseen to manage several hundreds of thousands channels.

  11. Femtosecond Yb-fiber chirped-pulse-amplification system based on chirped-volume Bragg gratings.

    PubMed

    Chang, Guoqing; Rever, Matthew; Smirnov, Vadim; Glebov, Leonid; Galvanauskas, Almantas

    2009-10-01

    A 100 W amplified (75 W compressed) femtosecond (650 fs) Yb-fiber chirped-pulse-amplification system is demonstrated using broadband chirped-volume Bragg gratings (CVBGs) for the stretcher and compressor. With a 75% compression efficiency, the CVBG-based compressor exhibits an excellent average power handling capability and indicates the potential for further power scaling with this compact and robust technology.

  12. Laboratory Model of the Cardiovascular System for Experimental Demonstration of Pulse Wave Propagation

    ERIC Educational Resources Information Center

    Stojadinovic, Bojana; Nestorovic, Zorica; Djuric, Biljana; Tenne, Tamar; Zikich, Dragoslav; Žikic, Dejan

    2017-01-01

    The velocity by which a disturbance moves through the medium is the wave velocity. Pulse wave velocity is among the key parameters in hemodynamics. Investigation of wave propagation through the fluid-filled elastic tube has a great importance for the proper biophysical understanding of the nature of blood flow through the cardiovascular system.…

  13. CONTROLLING THE CHARACTERISTICS OF LASER LIGHT: Stimulated-Raman pulse peaker for terawatt femtosecond laser systems

    NASA Astrophysics Data System (ADS)

    Losev, Leonid L.; Lutsenko, Andrei P.

    1993-04-01

    An optical layout for shortening the rise time of femtosecond light pulses is proposed. A stimulated-Raman converter operating on rotational levels of orthohydrogen is placed between amplifier stages of a wide-band, terawatt, femtosecond titanium-sapphire laser system. Light in the first Stokes component is extracted by a polarization technique and then amplified.

  14. Passive system with tunable group velocity for propagating electrical pulses from sub- to superluminal velocities.

    PubMed

    Haché, Alain; Essiambre, Sophie

    2004-05-01

    We report an observation of tunable group velocity from sub-luminal to superluminal in a completely passive system. Electric pulses are sent along a spatially periodic conducting medium containing a punctual nonlinearity, and the resulting amplitude-dependent phase shift allows us to control dispersion and the propagation velocity at the stop band frequency.

  15. Design of wireless triggering pulse generation for x-ray medical system

    NASA Astrophysics Data System (ADS)

    Ko, Dae-Sik; Lee, Jae-Cheol

    2007-12-01

    Digital x-ray imaging system is composed of an x-ray generator and a digital image acquisition system. In this paper, we designed a wireless trigger pulse generation circuit, detection trigger board, to capture the image accurately by established the synchronization between x-ray generator and digital image acquisition system and we analyzed its performance and compared to conventional method. There are two pulses generated by this study, the ACQ_START pulse, which indicates the detection of x-ray radiation from x-ray generator, and the ACQ_END pulse, which indicates the x-ray disappearance from x-ray generator. These trigger the image acquisition system of digital x-ray imaging system, to start the image capturing or to stop. Geiger tube were used to detect x-ray radiation from the air. Image acquisition is activated only this time between ACQ_START and ACQ_END signal. By detecting the x-ray radiation signal from the air and generate the trigger pulses, we can get more accurate timing for capturing the x-ray image. Also, owing to omitting the installation wire between x-ray generator and digital image acquisition system, Installation will be very easy. In addition to that, any type of x-ray generator can be installed without incompatibility. With this experiment, we tried to capture images of the resolution chart to compare the experimental result. We got 3.5 line pair / mm resolution at 20 mAs of x-ray level with resolution chart. This is same or better image comparing to conventional way.

  16. Mission management, planning, and cost: PULSE Attitude And Control Systems (AACS)

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The Pluto unmanned long-range scientific explorer (PULSE) is a probe that will do a flyby of Pluto. It is a low weight, relatively low costing vehicle which utilizes mostly off-the-shelf hardware, but not materials or techniques that will be available after 1999. A design, fabrication, and cost analysis is presented. PULSE will be launched within the first decade of the twenty-first century. The topics include: (1) scientific instrumentation; (2) mission management, planning, and costing; (3) power and propulsion systems; (4) structural subsystem; (5) command, control, and communication; and (6) attitude and articulation control.

  17. Recent advances in the applications of pulsed lasers in the hydrosphere. [considering airborne bathymetry system

    NASA Technical Reports Server (NTRS)

    Hickman, G. D.

    1975-01-01

    Laboratory and field measurements have been performed on the transmission/scattering characteristics of a pulsed neon laser as a function of water turbidity. These results have been used to establish the criteria for an airborne laser bathymetry system. Extensive measurements have been made of laser induced fluorescence using a pulsed tunable dye laser. Feasibility has been demonstrated for remote detection and possible identification of various types of algae and oils. Similar measurements made on a wide variety of organic dyes have shown this technique to have applications in remote measurements of subsurface currents, temperature and salinity.

  18. Determination of continuous system transfer functions from sampled pulse response data

    NASA Astrophysics Data System (ADS)

    Jordan, Jay B.; Watkins, Wendell R.; Palacios, Fernando R.; Billingsley, Daniel R.

    1994-12-01

    A method for determining the transfer function of a continuous system from sampled responses to single- and multiple-pulse excitation is presented. The method is an extension of the sampled-edge-response method pioneered by the theoretical work of A. Papoulis in 1962 and the application of the theory to optical systems by B. Tatian in 1965. Occasions arise when pulse rather than step-function stimuli are available for system excitations. In such cases, the method presented is useful for determining the system transfer function. The use of antialiasing filters and estimation of non-bandwidth-limited transfer functions are discussed. Practical application of the method to characterizing the system transfer function of a commercial 8- to 12-micrometers infrared imager is also presented.

  19. Improving the power efficiency of SOA-based UWB over fiber systems via pulse shape randomization

    NASA Astrophysics Data System (ADS)

    Taki, H.; Azou, S.; Hamie, A.; Al Housseini, A.; Alaeddine, A.; Sharaiha, A.

    2016-09-01

    A simple pulse shape randomization scheme is considered in this paper for improving the performance of ultra wide band (UWB) communication systems using On Off Keying (OOK) or pulse position modulation (PPM) formats. The advantage of the proposed scheme, which can be either employed for impulse radio (IR) or for carrier-based systems, is first theoretically studied based on closed-form derivations of power spectral densities. Then, we investigate an application to an IR-UWB over optical fiber system, by utilizing the 4th and 5th orders of Gaussian derivatives. Our approach proves to be effective for 1 Gbps-PPM and 2 Gbps-OOK transmissions, with an advantage in terms of power efficiency for short distances. We also examine the performance for a system employing an in-line Semiconductor Optical Amplifier (SOA) with the view to achieve a reach extension, while limiting the cost and system complexity.

  20. High fidelity femtosecond pulses from an ultrafast fiber laser system via adaptive amplitude and phase pre-shaping.

    PubMed

    Prawiharjo, Jerry; Daga, Nikita K; Geng, Rui; Price, Jonathan H; Hanna, David C; Richardson, David J; Shepherd, David P

    2008-09-15

    The generation of high-fidelity femtosecond pulses is experimentally demonstrated in a fiber based chirped-pulse amplification (CPA) system through an adaptive amplitude and phase pre-shaping technique. A pulse shaper, based on a dual-layer liquid crystal spatial light modulator (LC-SLM), was implemented in the fiber CPA system for amplitude and phase shaping prior to amplification. The LC-SLM was controlled using a differential evolution algorithm, to maximize a two-photon absorption detector signal from the compressed fiber CPA output pulses. It is shown that this approach compensates for both accumulated phase from material dispersion and nonlinear phase modulation. A train of pulses was produced with an average power of 12.6W at a 50MHz repetition rate from our fiber CPA system, which were compressible to high fidelity pulses with a duration of 170 fs.

  1. Optical generation of millimeter-wave pulses using a fiber Bragg grating in a fiber-optics system.

    PubMed

    Ye, Qing; Qu, Ronghui; Fang, Zujie

    2007-04-10

    A scheme is proposed to transform an optical pulse into a millimeter-wave frequency modulation pulse by using a weak fiber Bragg grating (FBG) in a fiber-optics system. The Fourier transformation method is used to obtain the required spectrum response function of the FBG for the Gaussian pulse, soliton pulse, and Lorenz shape pulse. On the condition of the first-order Born approximation of the weak fiber grating, the relation of the refractive index distribution and the spectrum response function of the FBG satisfies the Fourier transformation, and the corresponding refractive index distribution forms are obtained for single-frequency modulation and linear-frequency modulation millimeter-wave pulse generation. The performances of the designed fiber gratings are also studied by a numerical simulation method for a supershort pulse transmission.

  2. Signatures of two-photon pulses from a quantum two-level system

    NASA Astrophysics Data System (ADS)

    Fischer, Kevin A.; Hanschke, Lukas; Wierzbowski, Jakob; Simmet, Tobias; Dory, Constantin; Finley, Jonathan J.; Vučković, Jelena; Müller, Kai

    2017-07-01

    A two-level atom can generate a strong many-body interaction with light under pulsed excitation. The best known effect is single-photon generation, where a short Gaussian laser pulse is converted into a Lorentzian single-photon wavepacket. However, recent studies suggested that scattering of intense laser fields off a two-level atom may generate oscillations in two-photon emission that come out of phase with the Rabi oscillations, as the power of the pulse increases. Here, we provide an intuitive explanation for these oscillations using a quantum trajectory approach and show how they may preferentially result in emission of two-photon pulses. Experimentally, we observe the signatures of these oscillations by measuring the bunching of photon pulses scattered off a two-level quantum system. Our theory and measurements provide insight into the re-excitation process that plagues on-demand single-photon sources while suggesting the possibility of producing new multi-photon states.

  3. Recovery of a CVD diamond detection system from strong pulses of laser produced x-rays

    SciTech Connect

    Dauffy, L S; Koch, J A; Izumi, N; Tommasini, R; Lerche, R A

    2006-04-25

    We are studying the response of a CVD diamond detector to a strong x-ray pulse followed by a second weaker pulse arriving 50 to 300 ns later, with a contrast in amplitude of about 1000. These tests, performed at the LLNL Jupiter laser facility, are intended to produce charge carrier densities similar to those expected during a DT implosion at NIF, where a large 14.1 MeV neutron pulse is followed by a weak downscattered neutron signal produced by slower 6-10 MeV neutrons. The number of downscattered neutrons must be carefully measured in order to obtain an accurate value for the areal density, which is proportional to the ratio of downscattered to primary neutrons. The effects of the first strong pulse may include saturation of the diamond wafer, saturation of the oscilloscope, or saturation of the associated power and data acquisition electronics. We are presenting a double pulse experiment that will use a system of several polycrystalline CVD diamond detectors irradiated by 8.6 keV x-rays emitted from a zinc target. We will discuss implication for a NIF areal density measurement.

  4. Pulsed field probe of real time magnetization dynamics in magnetic nanoparticle systems

    NASA Astrophysics Data System (ADS)

    Foulkes, T.; Syed, M.; Taplin, T.

    2015-05-01

    Magnetic nanoparticles (MNPs) are extensively used in biotechnology. These applications rely on magnetic properties that are a keen function of MNP size, distribution, and shape. Various magneto-optical techniques, including Faraday Rotation (FR), Cotton-Mouton Effect, etc., have been employed to characterize magnetic properties of MNPs. Generally, these measurements employ AC or DC fields. In this work, we describe the results from a FR setup that uses pulsed magnetic fields and an analysis technique that makes use of the entire pulse shape to investigate size distribution and shape anisotropy. The setup employs a light source, polarizing components, and a detector that are used to measure the rotation of light from a sample that is subjected to a pulsed magnetic field. This magnetic field "snapshot" is recorded alongside the intensity pulse of the sample's response. This side by side comparison yields useful information about the real time magnetization dynamics of the system being probed. The setup is highly flexible with variable control of pulse length and peak magnitude. Examining the raw data for the response of bare Fe3O4 and hybrid Au and Fe3O4 nanorods reveals interesting information about Brownian relaxation and the hydrodynamic size of these nanorods. This analysis exploits the self-referencing nature of this measurement to highlight the impact of an applied field on creating a field induced transparency for a longitudinal measurement. Possible sources for this behavior include shape anisotropy and field assisted aggregate formation.

  5. Dependence of Initial Oxygen Concentration on Ozone Yield Using Inductive Energy Storage System Pulsed Power Generator

    NASA Astrophysics Data System (ADS)

    Go, Tomio; Tanaka, Yasushi; Yamazaki, Nobuyuki; Mukaigawa, Seiji; Takaki, Koichi; Fujiwara, Tamiya

    Dependence of initial oxygen concentration on ozone yield using streamer discharge reactor driven by an inductive energy storage system pulsed power generator is described in this paper. Fast recovery type diodes were employed as semiconductor opening switch to interrupt a circuit current within 100 ns. This rapid current change produced high-voltage short pulse between a secondary energy storage inductor. The repetitive high-voltage short pulse was applied to a 1 mm diameter center wire electrode placed in a cylindrical pulse corona reactor. The streamer discharge successfully occurred between the center wire electrode and an outer cylinder ground electrode of 2 cm inner diameter. The ozone was produced with the streamer discharge and increased with increasing pulse repetition rate. The ozone yield changed in proportion to initial oxygen concentration contained in the injected gas mixture at 800 ns forward pumping time of the current. However, the decrease of the ozone yield by decreasing oxygen concentration in the gas mixture at 180 ns forward pumping time of the current was lower than the decrease at 800 ns forward pumping time of the current. This dependence of the initial oxygen concentration on ozone yield at 180 ns forward pumping time is similar to that of dielectric barrier discharge reactor.

  6. FPGA based hardware optimized implementation of signal processing system for LFM pulsed radar

    NASA Astrophysics Data System (ADS)

    Azim, Noor ul; Jun, Wang

    2016-11-01

    Signal processing is one of the main parts of any radar system. Different signal processing algorithms are used to extract information about different parameters like range, speed, direction etc, of a target in the field of radar communication. This paper presents LFM (Linear Frequency Modulation) pulsed radar signal processing algorithms which are used to improve target detection, range resolution and to estimate the speed of a target. Firstly, these algorithms are simulated in MATLAB to verify the concept and theory. After the conceptual verification in MATLAB, the simulation is converted into implementation on hardware using Xilinx FPGA. Chosen FPGA is Xilinx Virtex-6 (XC6LVX75T). For hardware implementation pipeline optimization is adopted and also other factors are considered for resources optimization in the process of implementation. Focusing algorithms in this work for improving target detection, range resolution and speed estimation are hardware optimized fast convolution processing based pulse compression and pulse Doppler processing.

  7. Transient analysis of a pulsed detonation combustor using the numerical propulsion system simulation

    NASA Astrophysics Data System (ADS)

    Hasler, Anthony Scott

    The performance of a hybrid mixed flow turbofan (with detonation tubes installed in the bypass duct) is investigated in this study and compared with a baseline model of a mixed flow turbofan with a standard combustion chamber as a duct burner. Previous studies have shown that pulsed detonation combustors have the potential to be more efficient than standard combustors, but they also present new challenges that must be overcome before they can be utilized. The Numerical Propulsion System Simulation (NPSS) will be used to perform the analysis with a pulsed detonation combustor model based on a numerical simulation done by Endo, Fujiwara, et. al. Three different cases will be run using both models representing a take-off situation, a subsonic cruise and a supersonic cruise situation. Since this study investigates a transient analysis, the pulse detonation combustor is run in a rig setup first and then its pressure and temperature are averaged for the cycle to obtain quasi-steady results.

  8. All-reflective, highly accurate polarization rotator for high-power short-pulse laser systems.

    PubMed

    Keppler, S; Hornung, M; Bödefeld, R; Kahle, M; Hein, J; Kaluza, M C

    2012-08-27

    We present the setup of a polarization rotating device and its adaption for high-power short-pulse laser systems. Compared to conventional halfwave plates, the all-reflective principle using three zero-phase shift mirrors provides a higher accuracy and a higher damage threshold. Since plan-parallel plates, e.g. these halfwave plates, generate postpulses, which could lead to the generation of prepulses during the subsequent laser chain, the presented device avoids parasitic pulses and is therefore the preferable alternative for high-contrast applications. Moreover the device is easily scalable for large beam diameters and its spectral reflectivity can be adjusted by an appropriate mirror coating to be well suited for ultra-short laser pulses.

  9. Optimization of a grating pulse stretcher suitable for kJ class 10PW laser system

    NASA Astrophysics Data System (ADS)

    Vyhlídka, Štěpán; Kramer, Daniel; Kepler, Matt; Gaul, Erhard; Rus, Bedřich

    2017-05-01

    A comparison of various pulse stretcher designs accommodating material dispersion for a < 150 fs 10 PW Nd:glass laser system using low dispersion diffraction gratings is presented. Since the pulse amplification demands a high stretch ratio of the stretcher to suppress non-linear effects and a high temporal contrast of the pulse is required to avoid ionization of the experimental targets, the design of the stretcher is a critical part for dispersion management. Here, we compare several designs using only one diffraction grating based on either a Perry-Banks or an Offner stretcher types, mostly at the Littrow angle. The target spectral phase profile is achieved through the tuning of the grating position, the angle of incidence on the grating, the radii of curvature of curved mirrors and the line density of the grating.

  10. MEMPHIS 2000; A modular experiment multiparameter pulse height instrumentation system

    SciTech Connect

    Kayser, F.J.; Stevens, W.; Stoff, H.; Watzlawik, K.; Karnadi, M.; Gast, W. )

    1992-04-01

    This paper reports that for the data acquisition in nuclear physics experiments with multi detector arrays like OSIRIS (Compton Suppression Array for High Resolution in Beam Spectroscopy) and MEMPHIS 2000 System has been developed. The important features are the compact mechanics, the galvanic decoupling of the sensitive analog part from the host computer power supplies and the simple interfacing to existing computer hardware and ADCs. The use of Bit-Slice processors provides software control of the setup and the configuration of the whole system. The present realized one Crate version consists of 28 high resolution (16 bit) input channels for NIM-ADCs (Silena Type 7420/G, 7411), two Bit-Slice processors for ADC control and three microprocessors for software download, data transfer and setup. On-line acquisition, recording and analysis of experiment data as well as experiment control are implemented on the VAX-Station.

  11. Effects of Electromagnetic Pulses on a Multilayered System

    DTIC Science & Technology

    2014-07-01

    University at Buffalo, 230 Davis Hall, Buffalo, NY 14260 H. L. Moore, P. Haney US Army ARDEC, AMSRD-AAR-MEM, Building 65 S, Picatinny Arsenal, NJ...types of EMPs that are of concern regarding electronics and system infrastructures; they are high-altitude EMP ( HEMP ) generated from nuclear...is for 3-D full-wave electromagnetic field simulation and high frequency and high speed components [2]. The model used was designed and imported

  12. Lightning First Pulses Used in the "Last" (Time-of-Arrival) and "Atlas" (Single Station) Total Lightning Mapping Systems

    NASA Technical Reports Server (NTRS)

    Markson, Ralph; Ruhnke, Lothar

    1999-01-01

    The first RF pulse from "total lightning' discharges (cloud and ground flashes) has been used in different ways to locate the origin of flashes in two new types of lightning detection systems. The multisensor LASI time-of-arrival (TOA) system uses GPS timing of the first pulse. The ATLAS single sensor system uses the amplitude of the first pulse, which is invariant in magnitude and polarization for all lightning discharges, to determine distance from the sensor. It is significantly more accurate than past single sensor lightning mapping systems. The polarity of the first pulse generally identifies lightning type (IC or CG). Both systems utilize only the first pulse which makes signal processing much simpler than with previous lightning locating systems. Knowing the position where lightning begins (maximum electric fields, mixed phase hydrometeors and updrafts) is valuable for identifying convective cells producing the hazardous meteorological conditions caused by thunderstorms. It is also important for research studying thunderstorm electrification and associated microphysical problems.

  13. Application of magnetic pulse compression to the grid system of the ETA/ATA accelerator

    SciTech Connect

    Birx, D.L.; Cook, E.G.; Reginato, L.L.; Schmidt, J.A.; Smith, M.W.

    1982-11-02

    During the past year, several magnetic pulse compression systems have been built and applied to the ETA accelerator. In view of their excellent performance, a non-linear magnetic system has been adopted for the ATA grid drive in place of the spark gap driven Blumlein. The magnetic system will give us a much higher reliability and greater flexibility by being independent of the high pressure gas blown system. A further advantage of this system will be the capability of achieving higher rep-rates in case of a future upgrade. System design and performance under burst mode will be described.

  14. The development of an underwater pulsed compressive line sensing imaging system

    NASA Astrophysics Data System (ADS)

    Ouyang, Bing; Gong, Sue; Hou, Weilin; Dalgleish, Fraser R.; Caimi, Frank M.; Vuorenkoski, Anni K.

    2017-05-01

    Compressive Line Sensing (CLS) imaging system is a compressive sensing (CS) based imaging system with the goal of developing a compact and resource efficient imaging system for the degraded visual environment. In the CLS system, each line segment is sensed independently; however, the correlation among the adjacent lines (sources) is exploited via the joint sparsity in the distributed compressing sensing model during signal reconstruction. Several different CLS prototypes have been developed. This paper discusses the development of a pulsed CLS system. Initial experimental results using this system in a turbid water environment are presented.

  15. High-rate dead-time corrections in a general purpose digital pulse processing system.

    PubMed

    Abbene, Leonardo; Gerardi, Gaetano

    2015-09-01

    Dead-time losses are well recognized and studied drawbacks in counting and spectroscopic systems. In this work the abilities on dead-time correction of a real-time digital pulse processing (DPP) system for high-rate high-resolution radiation measurements are presented. The DPP system, through a fast and slow analysis of the output waveform from radiation detectors, is able to perform multi-parameter analysis (arrival time, pulse width, pulse height, pulse shape, etc.) at high input counting rates (ICRs), allowing accurate counting loss corrections even for variable or transient radiations. The fast analysis is used to obtain both the ICR and energy spectra with high throughput, while the slow analysis is used to obtain high-resolution energy spectra. A complete characterization of the counting capabilities, through both theoretical and experimental approaches, was performed. The dead-time modeling, the throughput curves, the experimental time-interval distributions (TIDs) and the counting uncertainty of the recorded events of both the fast and the slow channels, measured with a planar CdTe (cadmium telluride) detector, will be presented. The throughput formula of a series of two types of dead-times is also derived. The results of dead-time corrections, performed through different methods, will be reported and discussed, pointing out the error on ICR estimation and the simplicity of the procedure. Accurate ICR estimations (nonlinearity < 0.5%) were performed by using the time widths and the TIDs (using 10 ns time bin width) of the detected pulses up to 2.2 Mcps. The digital system allows, after a simple parameter setting, different and sophisticated procedures for dead-time correction, traditionally implemented in complex/dedicated systems and time-consuming set-ups.

  16. High-rate dead-time corrections in a general purpose digital pulse processing system

    PubMed Central

    Abbene, Leonardo; Gerardi, Gaetano

    2015-01-01

    Dead-time losses are well recognized and studied drawbacks in counting and spectroscopic systems. In this work the abilities on dead-time correction of a real-time digital pulse processing (DPP) system for high-rate high-resolution radiation measurements are presented. The DPP system, through a fast and slow analysis of the output waveform from radiation detectors, is able to perform multi-parameter analysis (arrival time, pulse width, pulse height, pulse shape, etc.) at high input counting rates (ICRs), allowing accurate counting loss corrections even for variable or transient radiations. The fast analysis is used to obtain both the ICR and energy spectra with high throughput, while the slow analysis is used to obtain high-resolution energy spectra. A complete characterization of the counting capabilities, through both theoretical and experimental approaches, was performed. The dead-time modeling, the throughput curves, the experimental time-interval distributions (TIDs) and the counting uncertainty of the recorded events of both the fast and the slow channels, measured with a planar CdTe (cadmium telluride) detector, will be presented. The throughput formula of a series of two types of dead-times is also derived. The results of dead-time corrections, performed through different methods, will be reported and discussed, pointing out the error on ICR estimation and the simplicity of the procedure. Accurate ICR estimations (nonlinearity < 0.5%) were performed by using the time widths and the TIDs (using 10 ns time bin width) of the detected pulses up to 2.2 Mcps. The digital system allows, after a simple parameter setting, different and sophisticated procedures for dead-time correction, traditionally implemented in complex/dedicated systems and time-consuming set-ups. PMID:26289270

  17. A chirped-pulse Fourier-transform microwave/pulsed uniform flow spectrometer. I. The low-temperature flow system.

    PubMed

    Oldham, James M; Abeysekera, Chamara; Joalland, Baptiste; Zack, Lindsay N; Prozument, Kirill; Sims, Ian R; Park, G Barratt; Field, Robert W; Suits, Arthur G

    2014-10-21

    We report the development of a new instrument that combines chirped-pulse microwave spectroscopy with a pulsed uniform supersonic flow. This combination promises a nearly universal detection method that can deliver isomer and conformer specific, quantitative detection and spectroscopic characterization of unstable reaction products and intermediates, product vibrational distributions, and molecular excited states. This first paper in a series of two presents a new pulsed-flow design, at the heart of which is a fast, high-throughput pulsed valve driven by a piezoelectric stack actuator. Uniform flows at temperatures as low as 20 K were readily achieved with only modest pumping requirements, as demonstrated by impact pressure measurements and pure rotational spectroscopy. The proposed technique will be suitable for application in diverse fields including fundamental studies in spectroscopy, kinetics, and reaction dynamics.

  18. A chirped-pulse Fourier-transform microwave/pulsed uniform flow spectrometer. I. The low-temperature flow system

    NASA Astrophysics Data System (ADS)

    Oldham, James M.; Abeysekera, Chamara; Joalland, Baptiste; Zack, Lindsay N.; Prozument, Kirill; Sims, Ian R.; Park, G. Barratt; Field, Robert W.; Suits, Arthur G.

    2014-10-01

    We report the development of a new instrument that combines chirped-pulse microwave spectroscopy with a pulsed uniform supersonic flow. This combination promises a nearly universal detection method that can deliver isomer and conformer specific, quantitative detection and spectroscopic characterization of unstable reaction products and intermediates, product vibrational distributions, and molecular excited states. This first paper in a series of two presents a new pulsed-flow design, at the heart of which is a fast, high-throughput pulsed valve driven by a piezoelectric stack actuator. Uniform flows at temperatures as low as 20 K were readily achieved with only modest pumping requirements, as demonstrated by impact pressure measurements and pure rotational spectroscopy. The proposed technique will be suitable for application in diverse fields including fundamental studies in spectroscopy, kinetics, and reaction dynamics.

  19. Investigation of Constant Temperature Hot-wire System Response using Laser Pulse

    NASA Astrophysics Data System (ADS)

    Jaffa, Nicholas; Morris, Scott; Cameron, Joshua

    2016-11-01

    Constant temperature hot-wire systems use a Wheatstone bridge and feedback amplifier circuit to maintain a constant average temperature across the wire yielding frequency responses of order 100 kHz. This high frequency response allows hot-wires to be used extensively for aerodynamic measurements in high speed flows and uncertainty at these high frequencies can be difficult to diagnose. The standard frequency response check for constant temperature hot-wires uses an electronic pulse across the circuit to check the electronic feedback circuit response time, but does not account for the impact of the heat transfer along the wire. In order to investigate the frequency response of the entire constant temperature hot-wire system, including the heat transfer along the wire, a novel method was developed using a pulsed PIV laser focused to illuminate only the hot-wire. The laser pulse duration was effectively an instantaneous change in wire surface temperature through radiation. A hot-wire was placed in a uniform open calibration jet for a range of flow conditions. The response of the entire hot-wire system was observed across a range of conditions including changes in flow, wire temperature, and thermal boundary conditions and compared with the electronic pulse test.

  20. Optimizing the performance of modulated pulse laser systems for imaging and ranging applications

    NASA Astrophysics Data System (ADS)

    Mullen, L.; Lee, R.; Illig, D.

    2017-05-01

    Blue-green laser systems are being developed for optical imaging and ranging in the underwater environment. The imaging application requires high range resolution to distinguish between multiple targets in the scene or between multiple target features, while the ranging application benefits from measurements with high range accuracy. The group at the Naval Air Warfare Center Aircraft Division (NAWCAD) in Patuxent River, MD has been investigating the merging of wideband radar modulation schemes with a pulsed laser system for underwater imaging and ranging applications. For the imaging application, the narrow peak produced by pulse compression at the receiver offers enhanced range resolution relative to traditional short pulse approaches. For ranging, the selection of modulation frequency bands approaching 1GHz provides backscatter and forward scatter suppression and enhanced range accuracy. Both passband and baseband digital processing have been applied to data collected in laboratory water tank experiments. The results have shown that the choice of processing scheme has a significant impact on optimizing the performance of modulated pulse laser systems for either imaging or ranging applications. These different processing schemes will be discussed, and results showing the effect of the processing schemes for imaging and ranging will be presented.

  1. Computer Controlled MHD Power Consolidation and Pulse Generation System

    DTIC Science & Technology

    1990-08-01

    applying the PASC technology to the diagonal generator connection. 3.2.1 Modeling the PASC Process Using EMTP 15 3.2.2 Discussion of Results 15...Controller 32 3.5.8 The Digital Controller 33 3.5.9 The Continuous Fourier Transform 34 3.5.10 Hardware Interface With The Existing System 35 3.5.11...Basic Assumptions Used In The Power-to weight 42 Ratio Calculation 3.6.2 Design of the PASC Transformer 43 3.6.3 Final Design Transformer Loss

  2. Upgrade of the SLAC SLED II Pulse Compression System Based on Recent High Power Tests

    SciTech Connect

    Vlieks, A.E.; Fowkes, W.R.; Loewen, R.J.; Tantawi, S.G.; /SLAC

    2011-09-06

    In the Next Linear Collider (NLC) it is expected that the high power rf components be able to handle peak power levels in excess of 400 MW. We present recent results of high power tests designed to investigate the RF breakdown limits of the X-band pulse compression system used at SLAC. (SLED-II). Results of these tests show that both the TE{sub 01}-TE{sub 10} mode converter and the 4-port hybrid have a maximum useful power limit of 220-250 MW. Based on these tests, modifications of these components have been undertaken to improve their peak field handling capability. Results of these modifications will be presented. As part of an international effort to develop a new 0.5-1.5 TeV electron-positron linear collider for the 21st century, SLAC has been working towards a design, referred to as 'The Next Linear Collider' (NLC), which will operate at 11.424 GHz and utilize 50-75 MW klystrons as rf power sources. One of the major challenges in this design, or any other design, is how to generate and efficiently transport extremely high rf power from a source to an accelerator structure. SLAC has been investigating various methods of 'pulse compressing' a relatively wide rf pulse ({ge} 1 {mu}s) from a klystron into a narrower, but more intense, pulse. Currently a SLED-II pulse compression scheme is being used at SLAC in the NLC Test Accelerator (NLCTA) and in the Accelerator Structures Test Area (ASTA) to provide high rf power for accelerator and component testing. In ASTA, a 1.05 {mu}s pulse from a 50 MW klystron was successfully pulse compressed to 205 MW with a pulse width of 150 ns. Since operation in NLC will require generating and transporting rf power in excess of 400 MW it was decided to test the breakdown limits of the SLED-II rf components in ASTA with rf power up to the maximum available of 400 MW. This required the combining of power from two 50 MW klystrons and feeding the summed power into the SLED-II pulse compressor. Results from this experiment demonstrated

  3. Direct estimation of aberrating delays in pulse-echo imaging systems.

    PubMed

    Rachlin, D

    1990-07-01

    Nearfield fluctuations in wave propagation velocity and system timing errors are among the sources of focusing aberrations in pulse-echo imaging systems. For situations in which the source of these errors can be modeled by a stationary phase aberrator placed in front of the transmitter and receiver aperture, appropriate electronic delays might be applied to the signals associated with each array element in order to restore the system to focus. A method is described and evaluated for estimating the set of aberrating delays in a linear array utilizing data from a single two-dimensional scan. The underlying principle is analogous to that of phase closure used for one-way passive interferometry and readily generalizes to two-dimensional arrays. Although the following theory is developed in the context of acoustic imaging, the general approach is applicable to other pulse-echo systems, such as radar.

  4. An 802.11 Wireless Blood Pulse-Oximetry System for Medical Response to Disasters

    PubMed Central

    Palmer, Douglas A.; Rao, Ramesh; Lenert, Leslie A.

    2005-01-01

    In a mass casualty situation, medical personnel at the disaster site and other field treatment settings may need to monitor the vital signs of hundreds of seriously injured patients with minimal staffing. The conditions may be primitive and personnel may have to improvise infrastructure. As part of our research to enhance medical response to disasters with Internet-enabled systems, we have developed a prototype Wireless Blood Pulse Oximeter system for mass casualty events designed to operate in WiFi hotspots. Pulse ox units were designed using low-cost embedded system technologies to operate in integrated or stand alone environments. Units can report data to a command post on the scene or any remote location with Internet access. The entire system is potentially capable of tracking and monitoring several hundred patients. PMID:16779359

  5. Pulse ESR of triplet states of large molecular π systems

    NASA Astrophysics Data System (ADS)

    Knorr, S.; Grupp, A.; Mehring, M.; Wehmeier, M.; Herwig, P.; Iyer, V. S.; Müllen, K.

    1998-08-01

    We report on the electronic properties of flat, disc-type molecules with extended π systems, which are designed as well-defined graphite subunit molecules by a new synthetic route. In our contribution, we have investigated the excited states of three benzenoid hydrocarbons—namely hexa-peri-hexabenzocoronene and two higher homologues—with time-resolved electron spin resonance (ESR) and optical techniques. After applying a laser flash to shock-frozen solutions of these molecules, we find excited states with lifetimes in the range of seconds. We have examined the fine-structure parameters of the triplet states in two molecules and furthermore observed the luminescence in the third one.

  6. Ytterbium fiber-based, 270 fs, 100 W chirped pulse amplification laser system with 1 MHz repetition rate

    NASA Astrophysics Data System (ADS)

    Zhao, Zhigang; Kobayashi, Yohei

    2016-01-01

    A 100 W Yb-doped, fiber-based, femtosecond, chirped pulse amplification laser system was developed with a repetition rate of 1 MHz, corresponding to a pulse energy of 100 µJ. Large-scale, fused-silica transmission gratings were used for both the pulse stretcher and compressor, with a compression throughput efficiency of ∼85%. A pulse duration of 270 fs was measured by second harmonic generation frequency-resolved optical gating (SHG-FROG). To the best of our knowledge, this is the shortest pulse duration ever achieved by a 100-W-level fiber chirped pulse amplification laser system at a repetition rate of few megahertz, without any special post-compression manipulation.

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

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  8. Pulse Code Modulation (PCM) encoder handbook for Aydin Vector MMP-600 series system

    NASA Astrophysics Data System (ADS)

    Currier, S. F.; Powell, W. R.

    1986-08-01

    The hardware and software characteristics of a time division multiplex system are described. The system is used to sample analog and digital data. The data is merged with synchronization information to produce a serial pulse coded modulation (PCM) bit stream. Information presented herein is required by users to design compatible interfaces and assure effective utilization of this encoder system. GSFC/Wallops Flight Facility has flown approximately 50 of these systems through 1984 on sounding rockets with no inflight failures. Aydin Vector manufactures all of the components for these systems.

  9. Pulse Code Modulation (PCM) encoder handbook for Aydin Vector MMP-600 series system

    NASA Technical Reports Server (NTRS)

    Currier, S. F.; Powell, W. R.

    1986-01-01

    The hardware and software characteristics of a time division multiplex system are described. The system is used to sample analog and digital data. The data is merged with synchronization information to produce a serial pulse coded modulation (PCM) bit stream. Information presented herein is required by users to design compatible interfaces and assure effective utilization of this encoder system. GSFC/Wallops Flight Facility has flown approximately 50 of these systems through 1984 on sounding rockets with no inflight failures. Aydin Vector manufactures all of the components for these systems.

  10. Development of a novel pulse wave velocity measurement system: using dual piezoelectric elements.

    PubMed

    Kitamura, Kei-ichiro; Takeuchi, Ryuya; Ogai, Kazuhiro; Xin, Zhu; Chen, Wenxi; Nemoto, Tetsu

    2014-07-01

    The aim of this study is to develop a painless system of measuring the brachial-ankle arterial pulse wave velocity (baPWV) without compression cuffs. The PWV reflects the compliance of the artery and is measured for the early diagnosis of arteriosclerotic vascular diseases. However, the conventional baPWV system, which measures four cuff pressures simultaneously, easily causes circulation block and tightening pain at the extremities. In addition, approximately 15 min are required to stabilise the blood pressure for re-examination. Therefore, we developed a novel baPWV measurement system using dual piezoelectric sensor elements. The principle of this high-sensitivity pressure pulse detection system is based on adding the two in-phase outputs from the coaxially arranged dual piezoelectric sensor. As our system facilitates the measurement of the baPWV by detecting the pulsation of an artery using sensors fixed on the skin where the pulse is palpable, it does not cause pain and reduces examination time. The coefficients of correlation between the baPWV values obtained from the conventional and present methods were 0.93 (right side) and 0.90 (left side). The results suggest that our system can be used to measure the baPWV without pressure cuffs as accurately as the conventional method. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

  11. Mucinous cystadenoma arising in a completely isolated infected ileal duplication cyst.

    PubMed

    Collaud, Stéphane; Bayerl, Christian; Wille, Georg; Zehnder, Adrian; Grieder, Felix; Meili, Severin; Decurtins, Marco

    2012-03-29

    Gastrointestinal duplications are uncommon congenital lesions that can occur anywhere along the alimentary tract, and the symptoms of which generally develop during infancy or childhood. Completely isolated duplication cysts are an extremely rare variant of duplication, where no communication between the cyst and the adjacent bowel segment is present. We report the unique case of an adult who presented with right lower abdominal pain and systemic signs of inflammation caused by infection of a completely isolated ileal duplication cyst. Histological examination of the cyst additionally revealed a low-grade mucinous cystadenoma. We discuss the clinical presentations, diagnosis and treatment of this rare entity.

  12. The MECP2 Duplication Syndrome

    PubMed Central

    Ramocki, Melissa B.; Tavyev, Y. Jane; Peters, Sarika U.

    2009-01-01

    In this review, we detail the history, molecular diagnosis, epidemiology, and clinical features of the MECP2 duplication syndrome, including considerations for the care of patients with this X-linked neurodevelopmental disorder. MECP2 duplication syndrome is 100% penetrant in affected males and is associated with infantile hypotonia, severe to profound mental retardation, autism or autistic features, poor speech development, recurrent infections, epilepsy, progressive spasticity, and, in some cases, developmental regression. Most of the reported cases are inherited, however, de novo cases have been documented. While carrier females have been reported to be unaffected, more recent research demonstrates that despite normal intelligence, female carriers display a range of neuropsychiatric phenotypes that pre-date the birth of an affected son. Given what we know of the syndrome to date, we propose that genetic testing is warranted in cases of males with infantile hypotonia and in cases of boys with mental retardation and autistic features with or without recurrent infections, progressive spasticity, epilepsy, or developmental regression. We discuss recommendations for clinical management and surveillance as well as the need for further clinical, genotype-phenotype, and molecular studies to assist the patients and their families who are affected by this syndrome. PMID:20425814

  13. Control of inertial acoustic cavitation in pulsed sonication using a real-time feedback loop system.

    PubMed

    Desjouy, Cyril; Poizat, Adrien; Gilles, Bruno; Inserra, Claude; Bera, Jean-Christophe

    2013-08-01

    Owing to the complex behavior of ultrasound-induced bubble clouds (nucleation, linear and nonlinear oscillations, collapse), acoustic cavitation remains a hardly controllable phenomenon, leading to poorly reproducible ultrasound-based therapies. A better control of the various aspects of cavitation phenomena for in vivo applications is a key requirement to improve emerging ultrasound therapies. Previous publications have reported on systems performing regulation of acoustic cavitation in continuous sonication when applied in vitro, but the main challenge today is to achieve real-time control of cavitation activity in pulsed sonication when used in vivo. The present work aims at developing a system to control acoustic cavitation in a pulsed wave condition using a real-time feedback loop. The experimental setup consists of a water bath in which is submerged a focused transducer (pulsed waves, frequency 550 kHz) used for sonication and a hydrophone used to listen to inertial cavitation. The designed regulation process allows the cavitation activity to be controlled through a 300 μs feedback loop. Without regulation, cavitation exhibits numerous bursts of intense activity and large variations of inertial cavitation level over time. In a regulated regime, the control of inertial cavitation activity within a pulse leads to consistent cavitation levels over time with an enhancement of the reproducibility.

  14. A pulse-burst laser system for a high-repetition-rate Thomson scattering diagnostic.

    PubMed

    Den Hartog, D J; Jiang, N; Lempert, W R

    2008-10-01

    A "pulse-burst" laser system is being constructed for addition to the Thomson scattering diagnostic on the Madison Symmetric Torus (MST) reversed-field pinch. This laser is designed to produce a burst of up to 200 approximately 1 J Q-switched pulses at repetition frequencies 5-250 kHz. This laser system will operate at 1064 nm and is a master oscillator, power amplifier. The master oscillator is a compact diode-pumped Nd:YVO(4) laser, intermediate amplifier stages are flashlamp-pumped Nd:YAG, and final stages will be flashlamp-pumped Nd:glass (silicate). Variable pulse width drive (0.3-20 ms) of the flashlamps is accomplished by insulated-gate bipolar transistor switching of large electrolytic capacitor banks. The burst train of laser pulses will enable the study of electron temperature (T(e)) and electron density (n(e)) dynamics in a single MST shot, and with ensembling, will enable correlation of T(e) and n(e) fluctuations with other fluctuating quantities.

  15. A pulse-burst laser system for a high-repetition-rate Thomson scattering diagnostic

    SciTech Connect

    Den Hartog, D. J.; Jiang, N.; Lempert, W. R.

    2008-10-15

    A ''pulse-burst'' laser system is being constructed for addition to the Thomson scattering diagnostic on the Madison Symmetric Torus (MST) reversed-field pinch. This laser is designed to produce a burst of up to 200 approximately 1 J Q-switched pulses at repetition frequencies 5-250 kHz. This laser system will operate at 1064 nm and is a master oscillator, power amplifier. The master oscillator is a compact diode-pumped Nd:YVO{sub 4} laser, intermediate amplifier stages are flashlamp-pumped Nd:YAG, and final stages will be flashlamp-pumped Nd:glass (silicate). Variable pulse width drive (0.3-20 ms) of the flashlamps is accomplished by insulated-gate bipolar transistor switching of large electrolytic capacitor banks. The burst train of laser pulses will enable the study of electron temperature (T{sub e}) and electron density (n{sub e}) dynamics in a single MST shot, and with ensembling, will enable correlation of T{sub e} and n{sub e} fluctuations with other fluctuating quantities.

  16. Validation of noninvasive MOEMS-assisted measurement system based on CCD sensor for radial pulse analysis.

    PubMed

    Malinauskas, Karolis; Palevicius, Paulius; Ragulskis, Minvydas; Ostasevicius, Vytautas; Dauksevicius, Rolanas

    2013-04-22

    Examination of wrist radial pulse is a noninvasive diagnostic method, which occupies a very important position in Traditional Chinese Medicine. It is based on manual palpation and therefore relies largely on the practitioner's subjective technical skills and judgment. Consequently, it lacks reliability and consistency, which limits practical applications in clinical medicine. Thus, quantifiable characterization of the wrist pulse diagnosis method is a prerequisite for its further development and widespread use. This paper reports application of a noninvasive CCD sensor-based hybrid measurement system for radial pulse signal analysis. First, artery wall deformations caused by the blood flow are calibrated with a laser triangulation displacement sensor, following by the measurement of the deformations with projection moiré method. Different input pressures and fluids of various viscosities are used in the assembled artificial blood flow system in order to test the performance of laser triangulation technique with detection sensitivity enhancement through microfabricated retroreflective optical element placed on a synthetic vascular graft. Subsequently, the applicability of double-exposure whole-field projection moiré technique for registration of blood flow pulses is considered: a computational model and representative example are provided, followed by in vitro experiment performed on a vascular graft with artificial skin atop, which validates the suitability of the technique for characterization of skin surface deformations caused by the radial pulsation.

  17. Study on mitigation of pulsed heat load for ITER cryogenic system

    NASA Astrophysics Data System (ADS)

    Peng, N.; Xiong, L. Y.; Jiang, Y. C.; Tang, J. C.; Liu, L. Q.

    2015-03-01

    One of the key requirements for ITER cryogenic system is the mitigation of the pulsed heat load deposited in the magnet system due to magnetic field variation and pulsed DT neutron production. As one of the control strategies, bypass valves of Toroidal Field (TF) case helium loop would be adjusted to mitigate the pulsed heat load to the LHe plant. A quasi-3D time-dependent thermal-hydraulic analysis of the TF winding packs and TF case has been performed to study the behaviors of TF magnets during the reference plasma scenario with the pulses of 400 s burn and repetition time of 1800 s. The model is based on a 1D helium flow and quasi-3D solid heat conduction model. The whole TF magnet is simulated taking into account thermal conduction between winding pack and case which are cooled separately. The heat loads are given as input information, which include AC losses in the conductor, eddy current losses in the structure, thermal radiation, thermal conduction and nuclear heating. The simulation results indicate that the temperature variation of TF magnet stays within the allowable range when the smooth control strategy is active.

  18. A 200 kV fast rise time, low jitter, trigger system with magnetic pulse sharpener

    SciTech Connect

    Jaitly, N.C.; Coleman, M.D.; Ramrus, A.; Earley, L.M.; Downing, J.N.; Reisch, H.H.; Caudill, L.D.; Eversol, S.A.

    1992-09-01

    The DARHT Facility is being designed at Los Alamos national Laboratory to produce high resolution flash radiographs of hydrodynamic experiments. Two linear induction accelerators (LIA), each in the range of 16 to 20 MeV, will be used to produce intense bremsstrahlung X-ray pulses of short duration (60 ns flat top). Each LIA will produce a 3 kA, high brightness, electron beam using a 4 MeV injector and a series of 250 kV induction cells. Technology demonstration of key accelerator subsystems is under progress at the DARHT Integrated Test Stand (ITS). The eight inductions cells present in the ITS are driven by a Maxwell prototype Induction Cell Pulsed Power supply (ICPPS) which provides 250 kV, 70 ns pulses via four Blumieins. Each Blumiein drives two cells and is triggered using independently controlled trigger units. This turnkey DARHT Trigger System, consisting of four separate trigger units, provides 200 kV trigger pulses with low jitter and fast rise time to each of the four Blumiein coaxial spark gaps. Details of the trigger system design and results obtained during extensive testing at Maxwell are described.

  19. Validation of Noninvasive MOEMS-Assisted Measurement System Based on CCD Sensor for Radial Pulse Analysis

    PubMed Central

    Malinauskas, Karolis; Palevicius, Paulius; Ragulskis, Minvydas; Ostasevicius, Vytautas; Dauksevicius, Rolanas

    2013-01-01

    Examination of wrist radial pulse is a noninvasive diagnostic method, which occupies a very important position in Traditional Chinese Medicine. It is based on manual palpation and therefore relies largely on the practitioner′s subjective technical skills and judgment. Consequently, it lacks reliability and consistency, which limits practical applications in clinical medicine. Thus, quantifiable characterization of the wrist pulse diagnosis method is a prerequisite for its further development and widespread use. This paper reports application of a noninvasive CCD sensor-based hybrid measurement system for radial pulse signal analysis. First, artery wall deformations caused by the blood flow are calibrated with a laser triangulation displacement sensor, following by the measurement of the deformations with projection moiré method. Different input pressures and fluids of various viscosities are used in the assembled artificial blood flow system in order to test the performance of laser triangulation technique with detection sensitivity enhancement through microfabricated retroreflective optical element placed on a synthetic vascular graft. Subsequently, the applicability of double-exposure whole-field projection moiré technique for registration of blood flow pulses is considered: a computational model and representative example are provided, followed by in vitro experiment performed on a vascular graft with artificial skin atop, which validates the suitability of the technique for characterization of skin surface deformations caused by the radial pulsation. PMID:23609803

  20. Fibre laser system providing generation of frequency-modulated pulses with a spectral width exceeding the gain linewidth

    NASA Astrophysics Data System (ADS)

    Zolotovskii, I. O.; Korobko, D. A.; Stoliarov, D. A.

    2016-12-01

    We propose an improved scheme of an amplifier similariton laser with a spectral width of the output significantly exceeding the gain linewidth. In the system, an additional dispersion element is inserted into the cavity to provide a local increase in the peak pulse power. The proposed scheme allows a reduction of pulse duration and an increase in peak power of the output pulse after compression.

  1. Ultrashort-pulse Ti:sapphire laser system pumped by frequency-doubled Nd:glass lasers

    NASA Astrophysics Data System (ADS)

    Bonlie, James D.; Price, Dwight F.; Sullivan, Alan; White, William E.

    1996-05-01

    We report on the development of a Chirped Pulse Amplification system in which the final amplifier is a large Ti:Sapphire disk pumped by a frequency doubled Nd:Glass laser. Using this amplifier we have produced near diffraction limited 120 fs pulses with energies in excess of 1 J. Focusing of these pulses results in peak irradiances exceeding 5 X 1019 W/cm2. The scalability of this amplifier to the 10 - 20 J level is also discussed.

  2. High-Average-Power Diffraction Pulse-Compression Gratings Enabling Next-Generation Ultrafast Laser Systems

    SciTech Connect

    Alessi, D.

    2016-11-01

    Pulse compressors for ultrafast lasers have been identified as a technology gap in the push towards high peak power systems with high average powers for industrial and scientific applications. Gratings for ultrashort (sub-150fs) pulse compressors are metallic and can absorb a significant percentage of laser energy resulting in up to 40% loss as well as thermal issues which degrade on-target performance. We have developed a next generation gold grating technology which we have scaled to the petawatt-size. This resulted in improvements in efficiency, uniformity and processing as compared to previous substrate etched gratings for high average power. This new design has a deposited dielectric material for the grating ridge rather than etching directly into the glass substrate. It has been observed that average powers as low as 1W in a compressor can cause distortions in the on-target beam. We have developed and tested a method of actively cooling diffraction gratings which, in the case of gold gratings, can support a petawatt peak power laser with up to 600W average power. We demonstrated thermo-mechanical modeling of a grating in its use environment and benchmarked with experimental measurement. Multilayer dielectric (MLD) gratings are not yet used for these high peak power, ultrashort pulse durations due to their design challenges. We have designed and fabricated broad bandwidth, low dispersion MLD gratings suitable for delivering 30 fs pulses at high average power. This new grating design requires the use of a novel Out Of Plane (OOP) compressor, which we have modeled, designed, built and tested. This prototype compressor yielded a transmission of 90% for a pulse with 45 nm bandwidth, and free of spatial and angular chirp. In order to evaluate gratings and compressors built in this project we have commissioned a joule-class ultrafast Ti:Sapphire laser system. Combining the grating cooling and MLD technologies developed here could enable petawatt laser systems to

  3. Mechanisms of Gene Duplication and Amplification

    PubMed Central

    Reams, Andrew B.; Roth, John R.

    2015-01-01

    Changes in gene copy number are among the most frequent mutational events in all genomes and were among the mutations for which a physical basis was first known. Yet mechanisms of gene duplication remain uncertain because formation rates are difficult to measure and mechanisms may vary with position in a genome. Duplications are compared here to deletions, which seem formally similar but can arise at very different rates by distinct mechanisms. Methods of assessing duplication rates and dependencies are described with several proposed formation mechanisms. Emphasis is placed on duplications formed in extensively studied experimental situations. Duplications studied in microbes are compared with those observed in metazoan cells, specifically those in genomes of cancer cells. Duplications, and especially their derived amplifications, are suggested to form by multistep processes often under positive selection for increased copy number. PMID:25646380

  4. Pulse tube cryocooler SQUID cooling system involving an infrared temperature controller cooled by a cryocooler

    NASA Astrophysics Data System (ADS)

    Tanaka, S.; Iwao, S.; Hatsukade, Y.

    2005-10-01

    We propose a pulse tube cryocooler SQUID cooling system, which temperature was controlled by an infrared source. A high-Tc SQUID magnetometer was mounted and cooled by a coaxial pulse tube cryocooler. A light from a halogen lamp was guided by a quartz flexible bundle fiber and was introduced to the cold head. The output power of the lamp was controlled by a temperature controller in accordance with the cold stage temperature. As a result, the flux noise of the SQUID output was not changed in the range of 1-1000 Hz regardless of the lamp power. The temperature could be controlled at 77 K with accuracy of ±0.03 K for long time duration more than 2 h. This demonstrated that the system can be applied to any applications such as NDE systems.

  5. Composite NDE using full-field pulse-echo ultrasonic propagation imaging system

    NASA Astrophysics Data System (ADS)

    Hong, Seung-Chan; Lee, Jung-Ryul; Park, Jongwoon

    2016-04-01

    In this paper, a novel ultrasonic propagation imaging system, called a full-field pulse-echo ultrasonic propagation imaging (FF PE UPI) system is presented. The coincided laser beams for ultrasonic sensing and generation are scanned and pulse-echo mode laser ultrasounds are captured. This procedure makes it possible to generate full-field ultrasound in through-the-thickness direction as large as the scan area. The system nondestructively inspected targets with two-axis translation stages. Various structural inspection results in the form of full-field ultrasonic wave propagation videos are introduced, which are an aluminum honeycomb sandwich, ailerons and carbon fiber reinforced plastic (CFRP) honeycomb sandwich structures including various defects.

  6. Complement C1r and C1s genes are duplicated in the mouse: differential expression generates alternative isomorphs in the liver and in the male reproductive system.

    PubMed Central

    Garnier, Gérard; Circolo, Antonella; Xu, Yuanyuan; Volanakis, John E

    2003-01-01

    C1r and C1s are the serine proteases that form the catalytic unit of the C1 complex, the first component of complement. In the present study, we found that the genes encoding murine C1r and C1s are duplicated. One set of these genes, referred to as c1rA and c1sA, are primarily expressed in the liver and are therefore the homologues of the human C1r and C1s genes. The other two genes, termed c1rB and c1sB, are expressed exclusively in male reproductive tissues, specifically the coagulating gland and the prostate. The predicted C1rB and C1sB proteins share 96 and 93% amino acid identity with C1rA and C1sA respectively. Most of the substitutions are clustered in the serine protease domains, suggesting differences in catalytic efficiencies and/or substrate specificities or alternatively adaptation to different physiological environments. The high homology of C1rB and C1sB with C1rA and C1sA in the non-catalytic regions indicates that they are probably capable of assembling the C1 complex. The expression of alternative genes encoding isomorphs of activating components of complement in male reproductive tissues raises the possibility of new mechanisms of complement activation in the male genital tract or of novel functions for complement proteases in reproduction. PMID:12513694

  7. Data acquisition system for the neutron scattering instruments at the intense pulsed neutron source

    SciTech Connect

    Crawford, R.K.; Daly, R.T.; Haumann, J.R.; Hitterman, R.L.; Morgan, C.B.; Ostrowski, G.E.; Worlton, T.G.

    1981-01-01

    The Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory is a major new user-oriented facility which is now coming on line for basic research in neutron scattering and neutron radiation damage. This paper describes the data-acquisition system which will handle data acquisition and instrument control for the time-of-flight neutron-scattering instruments at IPNS. This discussion covers the scientific and operational requirements for this system, and the system architecture that was chosen to satisfy these requirements. It also provides an overview of the current system implementation including brief descriptions of the hardware and software which have been developed.

  8. High Pulse Repetition Rate, Eye Safe, Visible Wavelength Lidar Systems: Design, Results and Potential

    NASA Technical Reports Server (NTRS)

    Spinhirne, James; Berkoff, Timothy; Welton, Elsworth; Campbell, James; OCStarr, David (Technical Monitor)

    2002-01-01

    In 1993 the first of the eye safe visible wavelength lidar systems known now as Micro Pulse Lidar (MPL) became operational. Since that time there have been several dozen of these systems produced and applied for full time profiling of atmospheric cloud and aerosol structure. There is currently an observational network of MPL sites to support global climate research. In the course of application of these instruments there have been significant improvements in understanding, design and performance of the systems. There are addition potential and applications beyond current practice for the high repetition rate, eye safe designs. The MPL network and the current capability, design and future potential of MPL systems are described.

  9. High Pulse Repetition Rate, Eye Safe, Visible Wavelength Lidar Systems: Design, Results and Potential

    NASA Technical Reports Server (NTRS)

    Spinhirne, James; Berkoff, Timothy; Welton, Elsworth; Campbell, James; OCStarr, David (Technical Monitor)

    2002-01-01

    In 1993 the first of the eye safe visible wavelength lidar systems known now as Micro Pulse Lidar (MPL) became operational. Since that time there have been several dozen of these systems produced and applied for full time profiling of atmospheric cloud and aerosol structure. There is currently an observational network of MPL sites to support global climate research. In the course of application of these instruments there have been significant improvements in understanding, design and performance of the systems. There are addition potential and applications beyond current practice for the high repetition rate, eye safe designs. The MPL network and the current capability, design and future potential of MPL systems are described.

  10. Study to investigate and evaluate means of optimizing the radar function. [systems engineering of pulse radar for the space shuttle

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The investigations for a rendezvous radar system design and an integrated radar/communication system design are presented. Based on these investigations, system block diagrams are given and system parameters are optimized for the noncoherent pulse and coherent pulse Doppler radar modulation types. Both cooperative (transponder) and passive radar operation are examined including the optimization of the corresponding transponder design for the cooperative mode of operation.

  11. Spectrally Tailored Pulsed Thulium Fiber Laser System for Broadband Lidar CO2 Sensing

    NASA Technical Reports Server (NTRS)

    Heaps, William S.; Georgieva, Elena M.; McComb, Timothy S.; Cheung, Eric C.; Hassell, Frank R.; Baldauf, Brian K.

    2011-01-01

    Thulium doped pulsed fiber lasers are capable of meeting the spectral, temporal, efficiency, size and weight demands of defense and civil applications for pulsed lasers in the eye-safe spectral regime due to inherent mechanical stability, compact "all-fiber" master oscillator power amplifier (MOPA) architectures, high beam quality and efficiency. Thulium fiber's longer operating wavelength allows use of larger fiber cores without compromising beam quality, increasing potential single aperture pulse energies. Applications of these lasers include eye-safe laser ranging, frequency conversion to longer or shorter wavelengths for IR countermeasures and sensing applications with otherwise tough to achieve wavelengths and detection of atmospheric species including CO2 and water vapor. Performance of a portable thulium fiber laser system developed for CO2 sensing via a broadband lidar technique with an etalon based sensor will be discussed. The fielded laser operates with approximately 280 J pulse energy in 90-150ns pulses over a tunable 110nm spectral range and has a uniquely tailored broadband spectral output allowing the sensing of multiple CO2 lines simultaneously, simplifying future potentially space based CO2 sensing instruments by reducing the number and complexity of lasers required to carry out high precision sensing missions. Power scaling and future "all fiber" system configurations for a number of ranging, sensing, countermeasures and other yet to be defined applications by use of flexible spectral and temporal performance master oscillators will be discussed. The compact, low mass, robust, efficient and readily power scalable nature of "all-fiber" thulium lasers makes them ideal candidates for use in future space based sensing applications.

  12. Pulse Data.

    ERIC Educational Resources Information Center

    Hands On!, 1998

    1998-01-01

    Presents an activity using computer software to investigate the role of the heart and blood, how the blood system responds to exercise, and how pulse rate is a good measure of physical condition. (ASK)

  13. Pulsed magnetic field measurement system based on colossal magnetoresistance-B-scalar sensors for railgun investigation.

    PubMed

    Stankevič, T; Medišauskas, L; Stankevič, V; Balevičius, S; Żurauskienė, N; Liebfried, O; Schneider, M

    2014-04-01

    A high pulsed magnetic field measurement system based on the use of CMR-B-scalar sensors was developed for the investigations of the electrodynamic processes in electromagnetic launchers. The system consists of four independent modules (channels) which are controlled by a personal computer. Each channel is equipped with a CMR-B-scalar sensor connected to the measurement device-B-scalar meter. The system is able to measure the magnitude of pulsed magnetic fields from 0.3 T to 20 T in the range from DC up to 20 kHz independently of the magnetic field direction. The measurement equipment circuit is electrically separated from the ground and shielded against low and high frequency electromagnetic noise. The B-scalar meters can be operated in the presence of ambient pulsed magnetic fields with amplitudes up to 0.2 T and frequencies higher than 1 kHz. The recorded signals can be transmitted to a personal computer in a distance of 25 m by means of a fiber optic link. The system was tested using the electromagnetic railgun RAFIRA installed at the French-German Research Institute of Saint-Louis, France.

  14. Long-pulse power-supply system for EAST neutral-beam injectors

    NASA Astrophysics Data System (ADS)

    Liu, Zhimin; Jiang, Caichao; Pan, Junjun; Liu, Sheng; Xu, Yongjian; Chen, Shiyong; Hu, Chundong; NBI Team

    2017-05-01

    The long-pulse power-supply system equipped for the 4 MW beam-power ion source is comprised of three units at ASIPP (Institute of Plasma Physics, Chinese Academy of Sciences): one for the neutral-beam test stand and two for the EAST neutral-beam injectors (NBI-1 and NBI-2, respectively). Each power supply system consists of two low voltage and high current DC power supplies for plasma generation of the ion source, and two high voltage and high current DC power supplies for the accelerator grid system. The operation range of the NB power supply is about 80 percent of the design value, which is the safe and stable operation range. At the neutral-beam test stand, a hydrogen ion beam with a beam pulse of 150 s, beam power of 1.5 MW and beam energy of 50 keV was achieved during the long-pulse testing experiments. The result shows that the power-supply system meets the requirements of the EAST-NBIs fully and lays a basis for achieving plasma heating.

  15. Probability characteristics of nonlinear dynamical systems driven by δ-pulse noise.

    PubMed

    Dubkov, Alexander A; Rudenko, Oleg V; Gurbatov, Sergey N

    2016-06-01

    For a nonlinear dynamical system described by the first-order differential equation with Poisson white noise having exponentially distributed amplitudes of δ pulses, some exact results for the stationary probability density function are derived from the Kolmogorov-Feller equation using the inverse differential operator. Specifically, we examine the "effect of normalization" of non-Gaussian noise by a linear system and the steady-state probability density function of particle velocity in the medium with Coulomb friction. Next, the general formulas for the probability distribution of the system perturbed by a non-Poisson δ-pulse train are derived using an analysis of system trajectories between stimuli. As an example, overdamped particle motion in the bistable quadratic-cubic potential under the action of the periodic δ-pulse train is analyzed in detail. The probability density function and the mean value of the particle position together with average characteristics of the first switching time from one stable state to another are found in the framework of the fast relaxation approximation.

  16. Probability characteristics of nonlinear dynamical systems driven by δ -pulse noise

    NASA Astrophysics Data System (ADS)

    Dubkov, Alexander A.; Rudenko, Oleg V.; Gurbatov, Sergey N.

    2016-06-01

    For a nonlinear dynamical system described by the first-order differential equation with Poisson white noise having exponentially distributed amplitudes of δ pulses, some exact results for the stationary probability density function are derived from the Kolmogorov-Feller equation using the inverse differential operator. Specifically, we examine the "effect of normalization" of non-Gaussian noise by a linear system and the steady-state probability density function of particle velocity in the medium with Coulomb friction. Next, the general formulas for the probability distribution of the system perturbed by a non-Poisson δ -pulse train are derived using an analysis of system trajectories between stimuli. As an example, overdamped particle motion in the bistable quadratic-cubic potential under the action of the periodic δ -pulse train is analyzed in detail. The probability density function and the mean value of the particle position together with average characteristics of the first switching time from one stable state to another are found in the framework of the fast relaxation approximation.

  17. Discharge formation systems for generating atomic iodine in a pulse-periodic oxygen–iodine laser

    SciTech Connect

    Aksinin, V I; Kazantsev, S Yu; Kononov, I G; Podlesnykh, S V; Firsov, K N; Antsiferov, S A; Velikanov, S D; Gerasimov, A Yu; Gostev, I V; Kalinovskii, V V; Konovalov, V V; Mikhalkin, V N; Sevryugin, I V

    2014-01-31

    Generation characteristics of a pulse-periodic oxygen–iodine laser with the electro-discharge production of atomic iodine were compared with inductively stabilised edged or anisotropic- resistive cathodes used for ignition of the volume discharge. The discharge was initiated by the radiation of a barrier discharge from the side of a grid anode. It was found that at equal specific electrical energy depositions to the gas-discharge plasma, the system with the anisotropic-resistive cathode provides a more stable and uniform volume discharge with the possibility of varying the composition and pressure of working mixtures over a wide range and a greater specific extraction of laser energy is observed (up to 2.4 J L{sup -1}). At a high pulse repetition rate of laser pulses (50 – 100 Hz) and long duration of the pulse trains (longer than a minute) the surface of anisotropic-resistive cathode became eroded. (laser applications and other topics in quantum electronics)

  18. Threshold determinations for selective retinal pigment epithelium damage with repetitive pulsed microsecond laser systems in rabbits.

    PubMed

    Framme, Carsten; Schuele, Georg; Roider, Johann; Kracht, Dietmar; Birngruber, Reginald; Brinkmann, Ralf

    2002-01-01

    In both clinical and animal studies, it has been shown that repetitive short laser pulses can cause selective retinal pigment epithelium damage (RPE) with sparing of photoreceptors. Our purpose was to determine the ophthalmoscopic and angiographic damage thresholds as a function of pulse durations by using different pulsed laser systems to optimize treatment modalities. Chinchilla-breed rabbits were narcotized and placed in a special holding system. Laser lesions were applied using a commercial laser slit lamp, contact lens, and irradiation with a frequency-doubled Nd:YLF laser (wave-length: 527 nm; repetition rate: 500 Hz; number of pulses: 100; pulse duration: 5 micros, 1.7 micros, 200 ns) and an argon-ion laser (514 nm, 500 Hz, 100 pulses, 5 micros and 200 ms). In all eyes, spots with different energies were placed into the regio macularis with a diameter of 102 microm (tophat profile). After treatment, fundus photography and fluorescein angiography were performed and radiant exposure for ED50 damage determined. Speckle measurements at the fiber tips were performed to determine intensity peaks in the beam profile. Using the Nd:YLF laser system, the ophthalmoscopic ED50 threshold energies were 25.4 microJ (5 micros), 32 microJ (1.7 micros), and 30 microJ (200 ns). The angiographic ED50 thresholds were 13.4 microJ (5 micros), 9.2 microJ (1.7 micros), and 6.7 microJ (200 ns). With the argon laser, the angiographic threshold for 5 micros pulses was 5.5 microJ. The ophthalmoscopic threshold could not be determined because of a lack of power; however, it was > 12 microJ. For 200 ms, the ED50 radiant exposures were 20.4 mW ophthalmoscopically and 19.2 mW angiographically. Speckle factors were found to be 1.225 for the Nd:YLF and 3.180 for the argon laser. Thus, the maximal ED50 -threshold radiant exposures for the Nd:YLF were calculated to be 362 mJ/cM2 (5 micros), 478 mJ/cm2 (1.7 micros), and 438 mJ/cm2 (200 ns) ophthalmoscopically. Angiographically, the thresholds

  19. Multi-soliton solutions and the Cauchy problem for a two-component short pulse system

    NASA Astrophysics Data System (ADS)

    Zhaqilao, Z.; Hu, Qiaoyi; Qiao, Zhijun

    2017-10-01

    In this paper, we study multi-soliton solutions and the Cauchy problem for a two-component short pulse system. For the multi-soliton solutions, we first derive an N-fold Darboux transformation from the Lax pair of the two-component short pulse system, which is expressed in terms of the quasideterminant. Then by virtue of the N-fold Darboux transformation we obtain multi-loop and breather soliton solutions. In particular, one-, two-, three-loop soliton, and breather soliton solutions are discussed in detail with interesting dynamical interactions and shown through figures. For the Cauchy problem, we first prove the existence and uniqueness of a solution with an estimate of the analytic lifespan, and then investigate the continuity of the data-to-solution map in the space of an analytic function.

  20. Interference effects during the reradiation of ultrashort electromagnetic pulses by polyatomic systems

    SciTech Connect

    Makarov, D. N.; Matveev, V. I.

    2013-11-15

    A theory of the reradiation of ultrashort electromagnetic pulses by arbitrary polyatomic systems of isolated complex atoms has been developed. The technique used allows the spatial inhomogeneity of the field of an ultrashort pulse and photon momenta in reradiation processes to be accurately taken into account. The angular distributions of the reradiation spectra have been obtained for an arbitrary number of atoms in the system. The processes of interference between the photon emission amplitudes are shown to give rise to characteristic “diffraction” maxima. We consider one-dimensional, two-dimensional, and three-dimensional rectangular lattices as examples as well as planar and cylindrical structures as models of planar nanosystems and nanotubes.

  1. Monte Carlo Simulation of Magnetization Recovery in Two-Dimensional Ferromagnetic System after Ultrafast Pump Pulses

    NASA Astrophysics Data System (ADS)

    Fang, WenXiao; En, YunFei; Zhou, Bin; Huang, QinWen; Liu, Xin; Chen, YiQiang

    2012-12-01

    The magnetization recovery of a two-dimensional ferromagnetic system after excitation by intensive ultrafast pump pulses is investigated by a Monte Carlo method with a focus on the evolution of domain structure and the magnetization in the equilibrium state. Our simulations can explain the effect of the pumping fluence on the recovery process. In particular, they reveal the importance of domain formation in the recently reported accumulation effect already found by the pump-probe magnetization hysteresis loop measurement of a metallic ferromagnetic film. In the framework of the model, it is predicted that by repeating pump pulses a sufficient number of times, the magnetization of the two-dimensional ferromagnetic system can be eliminated when the pump fluence is above a critical value.

  2. Entanglement creation in a quantum-dot-nanocavity system by Fourier-synthesized acoustic pulses

    NASA Astrophysics Data System (ADS)

    Blattmann, Ralf; Krenner, Hubert J.; Kohler, Sigmund; Hänggi, Peter

    2014-01-01

    We explore the possibility of entangling an excitonic two-level system in a semiconductor quantum dot with a cavity defined on a photonic crystal by sweeping the cavity frequency across its resonance with the exciton transition. The dynamic cavity detuning is established by a radio frequency surface acoustic wave (SAW). It induces Landau-Zener transitions between the excitonic and the photonic degrees of freedom and thereby creates a superposition state. We optimize this scheme by using tailored Fourier-synthesized SAW pulses with up to five harmonics. The theoretical study is performed with a master equation approach for present state-of-the-art setups. Assuming experimentally demonstrated system parameters, we show that the composed pulses increase both the maximum entanglement and its persistence. The latter is only limited by the dominant dephasing mechanism, i.e., the photon loss from the cavity.

  3. Counter-facing plasma focus system as an efficient and long-pulse EUV light source

    NASA Astrophysics Data System (ADS)

    Kuwabara, H.; Hayashi, K.; Kuroda, Y.; Nose, H.; Hotozuka, K.; Nakajima, M.; Horioka, K.

    2011-04-01

    A plasma focus system composed of a pair of counter-facing coaxial plasma guns is proposed as a long-pulse and efficient EUV light source. A proof-of-concept experiment demonstrated that with an assist of breakdown and outer electrode connections, current sheets evolved into a configuration for stable plasma confinement at the center of the electrode. The current sheets could successively compress and confine the high energy density plasma every half period of the discharge current, enabling highly repetitive light emissions in extreme ultraviolet region with time duration in at least ten microseconds for Xe plasma. Also, we confirmed operations of our system for Li plasma. We estimated the highest EUV energy in Li plasma operation at 93mJ/4π sr per 2% bandwidth per pulse.

  4. A portable high-field pulsed magnet system for x-ray scattering studies.

    SciTech Connect

    Islam, Z.; Ruff, J.P.C.; Nojiri, H.; Matsuda, Y. H.; Ross, K. A.; Gaulin, B. D.; Qu, Z.; Lang, J. C.

    2009-01-01

    We present a portable pulsed-magnet system for x-ray studies of materials in high magnetic fields (up to 30 T). The apparatus consists of a split-pair of minicoils cooled on a closed-cycle cryostat, which is used for x-ray diffraction studies with applied field normal to the scattering plane. A second independent closed-cycle cryostat is used for cooling the sample to near liquid helium temperatures. Pulsed magnetic fields (- 1 ms in total duration) are generated by discharging a configurable capacitor bank into the magnet coils. Time-resolved scattering data are collected using a combination of a fast single-photon counting detector, a multichannel scaler, and a high-resolution digital storage oscilloscope. The capabilities of this instrument are used to study a geometrically frustrated system revealing strong magnetostrictive effects in the spin-liquid state.

  5. [An integral chip for the multiphase pulse-duration modulation used for voltage changer in biomedical microprocessor systems].

    PubMed

    Balashov, A M; Selishchev, S V

    2004-01-01

    An integral chip (IC) was designed for controlling the step-down pulse voltage converter, which is based on the multiphase pulse-duration modulation, for use in biomedical microprocessor systems. The CMOS technology was an optimal basis for the IC designing. An additional feedback circuit diminishes the output voltage dispersion at dynamically changing loads.

  6. 48 CFR 1852.208-81 - Restrictions on Printing and Duplicating.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Restrictions on Printing... Provisions and Clauses 1852.208-81 Restrictions on Printing and Duplicating. As prescribed in 1808.870, insert the following clause: Restrictions on Printing and Duplicating (NOV 2004) (a) The Contractor may...

  7. 48 CFR 1852.208-81 - Restrictions on Printing and Duplicating.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Restrictions on Printing... Provisions and Clauses 1852.208-81 Restrictions on Printing and Duplicating. As prescribed in 1808.870, insert the following clause: Restrictions on Printing and Duplicating (NOV 2004) (a) The Contractor may...

  8. 48 CFR 1852.208-81 - Restrictions on Printing and Duplicating.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Restrictions on Printing... Provisions and Clauses 1852.208-81 Restrictions on Printing and Duplicating. As prescribed in 1808.870, insert the following clause: Restrictions on Printing and Duplicating (NOV 2004) (a) The Contractor may...

  9. Zero-derivative boundary condition for pulsed distributed systems. [column chromatography example

    NASA Technical Reports Server (NTRS)

    Lashmet, P. K.; Woodrow, P. T.

    1975-01-01

    To permit use of experimentally determined Peclet numbers in numerical simulations of pulsed distributed flow systems such as chromatograph columns, substitution of the zero-derivative boundary condition for the infinite boundary condition used in treating data is examined. Moment analysis shows that application of the zero-derivative condition external to the column will yield equivalent numerical results for the two boundary conditions. Criteria for locating this position are provided as a function of the Peclet number.

  10. A Pulsed Power System Design Using Lithium-ion Batteries and One Charger per Battery

    DTIC Science & Technology

    2009-12-01

    LITHIUM - ION BATTERIES AND ONE CHARGER PER BATTERY by Frank E. Filler December 2009 Thesis Advisor: Alexander L. Julian...Master’s Thesis 4. TITLE AND SUBTITLE A Pulsed Power System Design Using Lithium - ion Batteries and One Charger per Battery 6. AUTHOR(S) Frank E...The BMS design uses lithium - ion batteries as the energy storage medium and uses one charger per battery for maximum

  11. Laser fusion pulse shape controller

    DOEpatents

    Siebert, Larry D.

    1977-01-01

    An apparatus for controlling the pulse shape, i.e., the pulse duration and intensity pattern, of a pulsed laser system, and which is particularly well adapted for controlling the pellet ignition pulse in a laser-driven fusion reaction system. The apparatus comprises a laser generator for providing an optical control pulse of the shape desired, a pulsed laser triggered by the control pulse, and a plurality of optical Kerr-effect gates serially disposed at the output of the pulsed laser and selectively triggered by the control pulse to pass only a portion of the pulsed laser output generally corresponding in shape to the control pulse.

  12. Laboratory model of the cardiovascular system for experimental demonstration of pulse wave propagation

    NASA Astrophysics Data System (ADS)

    Stojadinović, Bojana; Nestorović, Zorica; Djurić, Biljana; Tenne, Tamar; Zikich, Dragoslav; Žikić, Dejan

    2017-03-01

    The velocity by which a disturbance moves through the medium is the wave velocity. Pulse wave velocity is among the key parameters in hemodynamics. Investigation of wave propagation through the fluid-filled elastic tube has a great importance for the proper biophysical understanding of the nature of blood flow through the cardiovascular system. Here, we present a laboratory model of the cardiovascular system. We have designed an experimental setup which can help medical and nursing students to properly learn and understand basic fluid hemodynamic principles, pulse wave and the phenomenon of wave propagation in blood vessels. Demonstration of wave propagation allowed a real time observation of the formation of compression and expansion waves by students, thus enabling them to better understand the difference between the two waves, and also to measure the pulse wave velocity for different fluid viscosities. The laboratory model of the cardiovascular system could be useful as an active learning methodology and a complementary tool for understanding basic principles of hemodynamics.

  13. Development of glucose measurement system based on pulsed laser-induced ultrasonic method

    NASA Astrophysics Data System (ADS)

    Ren, Zhong; Wan, Bin; Liu, Guodong; Xiong, Zhihua

    2016-09-01

    In this study, a kind of glucose measurement system based on pulsed-induced ultrasonic technique was established. In this system, the lateral detection mode was used, the Nd: YAG pumped optical parametric oscillator (OPO) pulsed laser was used as the excitation source, the high sensitivity ultrasonic transducer was used as the signal detector to capture the photoacoustic signals of the glucose. In the experiments, the real-time photoacoustic signals of glucose aqueous solutions with different concentrations were captured by ultrasonic transducer and digital oscilloscope. Moreover, the photoacoustic peak-to-peak values were gotten in the wavelength range from 1300nm to 2300nm. The characteristic absorption wavelengths of glucose were determined via the difference spectral method and second derivative method. In addition, the prediction models of predicting glucose concentrations were established via the multivariable linear regression algorithm and the optimal prediction model of corresponding optimal wavelengths. Results showed that the performance of the glucose system based on the pulsed-induced ultrasonic detection method was feasible. Therefore, the measurement scheme and prediction model have some potential value in the fields of non-invasive monitoring the concentration of the glucose gradient, especially in the food safety and biomedical fields.

  14. Analysis of nitrogen plasma generated by a pulsed plasma system near atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Hayakawa, R.; Yoshimura, T.; Ashida, A.; Fujimura, N.; Kitahata, H.; Yuasa, M.

    2004-12-01

    Stable discharging of pure nitrogen can be maintained even at atmospheric pressure when alternative pulsed voltage is applied between two parallel plate electrodes. We evaluated the nitrogen plasma generated by an alternative pulsed voltage system. The excited nitrogen species in a pure nitrogen plasma was evaluated using optical emission spectroscopy. In the discharging space, the largest peak detected corresponded to the N2 second positive system. Additionally, the emission peaks from the excited nitrogen atom were detected at a pressure of as high as 45Torr. In the downstream space, we detected emission peaks from the N2 Herman's infrared system as well as the N2 second positive system. The N2 (AΣu+3) state is considered to be the origin of the N2 Herman's infrared system. The emission intensities from the N2 second positive system and the N2 Herman's infrared system increase with increasing nitrogen gas pressure, whereas the emission intensity from the N2+ first negative system decreases.

  15. Spectral broadening and compression of high-intensity laser pulses in quasi-periodic systems with Kerr nonlinearity

    SciTech Connect

    Vlasov, Sergei N; Koposova, E V; Yashin, V E

    2012-11-30

    We report the results of theoretical studies and numerical simulations of optical high-power pulse compression systems based on the spectral broadening in a Kerr nonlinear medium with subsequent pulse compression in a dispersive delay line. It is shown that the effective spectral broadening requires suppressing a smallscale instability arising due to self-focusing, which is possible in quasi-periodic systems consisting of a nonlinear medium and optical relay telescopes transmitting images of the laser beam through the system. The numerical calculations have shown the possibility of broadening the spectrum, followed by 15-fold pulse compression until the instability is excited. (control of laser radiation parameters)

  16. 10 CFR 9.35 - Duplication fees.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Duplication fees. 9.35 Section 9.35 Energy NUCLEAR REGULATORY COMMISSION PUBLIC RECORDS Freedom of Information Act Regulations § 9.35 Duplication fees. (a)(1...″ reduced). Pages 11″ × 17″ are $0.30 per page. Pages larger than 11″ × 17″, including engineering...

  17. Some asymptotic properties of duplication graphs

    NASA Astrophysics Data System (ADS)

    Raval, Alpan

    2003-12-01

    Duplication graphs are graphs that grow by duplication of existing vertices, and are important models of biological networks, including protein-protein interaction networks and gene regulatory networks. Three models of graph growth are studied: pure duplication growth, and two two-parameter models in which duplication forms one element of the growth dynamics. A power-law degree distribution is found to emerge in all three models. However, the parameter space of the latter two models is characterized by a range of parameter values for which duplication is the predominant mechanism of graph growth. For parameter values that lie in this “duplication-dominated” regime, it is shown that the degree distribution either approaches zero asymptotically, or approaches a nonzero power-law degree distribution very slowly. In either case, the approach to the true asymptotic degree distribution is characterized by a dependence of the scaling exponent on properties of the initial degree distribution. It is therefore conjectured that duplication-dominated, scale-free networks may contain identifiable remnants of their early structure. This feature is inherited from the idealized model of pure duplication growth, for which the exact finite-size degree distribution is found and its asymptotic properties studied.

  18. 40 CFR 710.35 - Duplicative reporting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Duplicative reporting. 710.35 Section 710.35 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT TSCA CHEMICAL INVENTORY REGULATIONS 2002 Inventory Update Reporting § 710.35 Duplicative...

  19. 40 CFR 710.35 - Duplicative reporting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Duplicative reporting. 710.35 Section 710.35 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT TSCA CHEMICAL INVENTORY REGULATIONS 2002 Inventory Update Reporting § 710.35 Duplicative...

  20. 40 CFR 711.22 - Duplicative reporting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Duplicative reporting. 711.22 Section 711.22 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT TSCA CHEMICAL DATA REPORTING REQUIREMENTS § 711.22 Duplicative reporting. (a) With regard to TSCA...