Science.gov

Sample records for multiple pulse overlap

  1. Time-of-flight diffractometer with multiple pulse overlap - an example for the application of modern tools for instrument design

    SciTech Connect

    Stuhr, U.; Bauer, G.S.; Wagner, W.

    1997-09-01

    A Time-of-Flight Diffractometer with high pulse rates, allowing multiple frame overlap, is a completely novel design of an instrument dedicated for high resolution strain-field mapping. We elaborated a detailed concept of this instrument applying analytical calculations and Monte Carlo computer simulations. Having established the instrument concept, the computer simulations will now be extended to optimize the total performance of the instrument. To illustrate the necessity and possibilities of applying modem tools for instrument design, we describe, as an example, the different steps towards the development of the detailed design of this instrument, which we intend to build at the Swiss spallation. source SINQ in the near future.

  2. Multiple pulse laser

    SciTech Connect

    Hughes, R.S.; Jernigan, J.L.

    1981-02-10

    A multiple pulse laser from a single resonant cavity is disclosed. An acousto-optic cell is used to modulate coherent light from a lasing element. Either multiple chirp signals or a masked mirror are used to provide distinct pulses of light. Through proper choice of materials for the acousto-optic cell and use of divergent optics, a higher power level is obtained. Use of a multi-tapped delay line permits a shorter period between pulses due to the linear superposition principle. When the mask embodiment is used, the acousto-optic cell focuses light which scans across the mask. Whenever the focused light passes through the mask, lasing occurs which generates an output pulse.

  3. How multiple supernovae overlap to form superbubbles

    NASA Astrophysics Data System (ADS)

    Yadav, Naveen; Mukherjee, Dipanjan; Sharma, Prateek; Nath, Biman B.

    2016-10-01

    We explore the formation of superbubbles through energy deposition by multiple supernovae (SNe) in a uniform medium. We use total energy conserving, 3-D hydrodynamic simulations to study how SNe correlated in space and time create superbubbles. While isolated SNe fizzle out completely by ˜1 Myr due to radiative losses, for a realistic cluster size it is likely that subsequent SNe go off within the hot/dilute bubble and sustain the shock till the cluster lifetime. For realistic cluster sizes, we find that the bubble remains overpressured only if, for a given ng0, NOB is sufficiently large. While most of the input energy is still lost radiatively, superbubbles can retain up to ˜5 - 10% of the input energy in form of kinetic+thermal energy till 10 Myr for ISM density ng0 ≈ 1 cm-3. We find that the mechanical efficiency decreases for higher densities (η _mech ∝ n_{g0}^{-2/3}). We compare the radii and velocities of simulated supershells with observations and the classical adiabatic model. Our simulations show that the superbubbles retain only ≲ 10% of the injected energy, thereby explaining the observed smaller size and slower expansion of supershells. We also confirm that a sufficiently large (≳ 104) number of SNe is required to go off in order to create a steady wind with a stable termination shock within the superbubble. We show that the mechanical efficiency increases with increasing resolution, and that explicit diffusion is required to obtain converged results.

  4. Detection of multiple velocity components in partially overlapping emitting regions

    NASA Astrophysics Data System (ADS)

    Mertens, F.; Lobanov, A. P.

    2016-03-01

    Context. Velocity measurements made from multiple-epoch astronomical images of evolving objects with optically thin continuum emission (e.g. as relativistic jets or expanding supernova shells) may be confused as a result of the overlap of semi-transparent features moving at different speeds. Aims: Multi-scale wavelet decomposition can be effectively applied to identify and track such overlapping features, provided that their respective structural responses can be separated over the spatial scales used for the decomposition. Methods: We developed a new method that combines the stacked cross-correlation with the wavelet-based image segmentation and evaluation (WISE) technique of decomposition of two-dimensional structures, to separate and track dominant spatial responses of overlapping evolving features. Results: The method is tested on a set of simulated images of a stratified relativistic jet, demonstrating the robust detection of both the faster spine and the slower sheath speeds. The method is applied to mutliple-epoch images from the MOJAVE survey, revealing two different superluminal streams inside the jet in 3C 273 and the acceleration of the flow in 3C 120. Conclusions: The method can be applied to densely monitored objects with composite structural evolution such as the parsec-scale jet in M 87 or heavily resolved expanding supernova shells.

  5. Multiple overlapping resonance treatment in electron-cadmium ionization

    NASA Astrophysics Data System (ADS)

    Tabanli, M. M.; Peacher, J. L.; Madison, D. H.

    2001-05-01

    The effect of autoionizing resonances on ionization has been studied since the historic work of Fano. We have calculated triple differential cross sections for electron-cadmium scattering using a multiple overlapping resonance treatment. Our (DWBA) results are compared to the non-overlapping resonance treatment of Madison et al.(D. H. Madison, V. D. Kravtsov, J. B. Dent, and M. Wilson Phys. Rev. A) 56, 1983 (1997). and coincidence measurements made by Martin et al.(N. L. S. Martin, R. P. Bauman, and M. Wilson Phys. Rev. A) 57, 1827 (1998). at an incident electron energy of 150 eV. The ejected electron energy was near 3.5 eV and measurements were made for scattering angles between 2 and 15 degrees. Last year we presented preliminary results for the scattering angles of 2 and 3 degrees. We have now reformulated the phase of the mixing coefficients and the transition amplitude to include spin explicitly. The new treatment gives significantly better results for scattering angles larger than 6 degrees. This new approach also gives a sharp minimun and maximum near the third resonance.

  6. Can Multiple Hereditary Exostoses Overlap With Mesomelic Dysplasia?

    PubMed Central

    Al Kaissi, Ali; Ben Ghachem, Maher; Ben Chehida, Farid; Hofstaetter, Jochen G.; Grill, Franz; Ganger, Rudolf; Kircher, Susanne Gerit

    2016-01-01

    Background We studied an unusual combination of severe short stature, mesomelia (Leri-Weill dyschondrosteosis syndrome), and multiple exostosis in several family subjects over three generations. The pattern of inheritance was compatible with autosomal dominant. Methods Of 21 affected members over three generations, shortness of stature, associated with mesomelia resembling Leri-Weill dyschondrosteosis syndrome with no exostoses was evident in three family subjects. The rest of the family subjects manifested with normal height, and yet multiple exostoses. In this family, the skeletal manifestations were sufficiently variable for the presentation to be with either short stature or scoliosis, a Madelung’ deformity, or with severe hallux valgus associated with exostosis and with Leri-Weill dyschondrosteosis syndrome. Results Subjects with structural chromosomal aberrations of the proband IV-7, who manifested with normal height but with multiple exostoses were excluded via 20 CAG-banded mitoses (there were no microdeletions or microduplication after performing Array-CGH-analysis). In addition, DNA examination for subject IV-8 (male cousin of the proband showed short stature and Leri-Weill dyschondrosteosis syndrome) revealed no evidence of SHOX deletions. Conclusion We described a multigenerational non-consanguineous North African family , in which mesomelic dysplasia, whose clinical and radiological phenotypes resembled dyschondrosteosis, was a prominent feature in three family subjects. Multiple exostoses were evident in several other family subjects (most were with normal height). We would like to emphasize the variability in the phenotypic expression of multiple exostosis, especially the confusion that might arise when the condition appears both clinically and radiologically to be more complicated, and the overall picture might then be overlapped with one of the other bone dysplasias such as Leri-Weill dyschondrosteosis syndrome. PMID:27429682

  7. Advanced UXO discrimination: resolving multiple targets and overlapping EMI signals

    NASA Astrophysics Data System (ADS)

    Shubitidze, Fridon; Barrowes, Benjamin E.; Shamatava, Irma; Fernandez, Juan Pablo; Bijamov, Alex; O'Neill, Kevin

    2011-06-01

    In this paper we employ advanced electromagnetic induction models to resolve multiple targets with overlapping EMI signals-i.e. to discriminate objects of interest, such as unexploded ordnance (UXO), from innocuous items. The models include a) a joint diagonalization (JD) technique that takes data from next-generation EMI sensors and uses the eigenvalues of the multistatic response matrix to estimate the number of potential targets, and b) the orthonormalized volume magnetic source (ONVMS) model, a physically complete, fast, and accurate forward model whose representation of a target's intrinsic EMI response is used to extract classification parameters. In the given approach the overall EMI inversion and classification problem proceeds as follows: first, the JD is applied to the data and the number of targets is estimated; once this is known, the ONVMS is combined with an optimization technique to yield the location and orientation of each buried object, as well as the amplitude of its ONVMS. Finally, a total ONVMS is calculated for each object and used as a discriminant to distinguish between UXO and non-UXO items and between different kinds of UXO. We illustrate the applicability of our multi-target analysis technique by using it on several teststand and live-site datasets collected with the TEMTADS sensor array. We end by demonstrating the superior performance of the ONVMS by applying it to multi-target blind-test data compiled at the Aberdeen Proving Ground test-stand facility.

  8. Multiple overlapping homologies between two rheumatoid antigens and immunosuppressive viruses.

    PubMed Central

    Douvas, A; Sobelman, S

    1991-01-01

    Amino acid (aa) sequence homologies between viruses and autoimmune nuclear antigens are suggestive of viral involvement in disorders such as systemic lupus erythematosus (SLE) and scleroderma. We analyzed the frequency of exact homologies of greater than or equal to 5 aa between 61 viral proteins (19,827 aa), 8 nuclear antigens (3813 aa), and 41 control proteins (11,743 aa). Both pentamer and hexamer homologies between control proteins and viruses are unexpectedly abundant, with hexamer matches occurring in 1 of 3 control proteins (or once every 769 aa). However, 2 nuclear antigens, the SLE-associated 70-kDa antigen and the scleroderma-associated CENP-B protein, are highly unusual in containing multiple homologies to a group of synergizing immunosuppressive viruses. Two viruses, herpes simplex virus 1 (HSV-1) and human immunodeficiency virus 1 (HIV-1), contain sequences exactly duplicated at 15 sites in the 70-kDa antigen and at 10 sites in CENP-B protein. The immediate-early (IE) protein of HSV-1, which activates HIV-1 regulatory functions, contains three homologies to the 70-kDa antigen (two hexamers and a pentamer) and two to CENP-B (a hexamer and pentamer). There are four homologies (including a hexamer) common to the 70-kDa antigen and Epstein-Barr virus, and three homologies (including two hexamers) common to CENP-B and cytomegalovirus. The majority of homologies in both nuclear antigens are clustered in highly charged C-terminal domains containing epitopes for human autoantibodies. Furthermore, most homologies have a contiguous or overlapping distribution, thereby creating a high density of potential epitopes. In addition to the exact homologies tabulated, motifs of matching sequences are repeated frequently in these domains. Our analysis suggests that coexpression of heterologous viruses having common immunosuppressive functions may generate autoantibodies cross-reacting with certain nuclear proteins. PMID:1712488

  9. Multiple Access in Ultra-Wideband Communications Using Multiple Pulses

    SciTech Connect

    Nekoogar, F; Dowla, F

    2003-04-11

    Multiple access (MA) in UWB communication is an area of active research. To date several time-division or code-division pulse amplitude modulation (PAM) or pulse position modulation (PPM) schemes have been proposed to separate multiple users in UWB communications. Conventionally, all users employ the same pulse shape and modulate the transmit pulse based on changing amplitude or position. One concern with using the same pulse for all channels is that the multiple access interference (MAI) increases as the number of users increase. This is due to increased cross-correlation between similar pulses of the different channels, raising thus the noise floor in such systems. In this paper we introduce and study the performance of a new MA scheme in the context of multiple orthogonal transmitted-reference (T-R) short duration (nsec) chirp pulses in the presence of multipath and additive white Gaussian noise (AWGN).

  10. Management of Complicated Aortic Aneurysms Using Multiple Overlapping Uncovered Stents

    PubMed Central

    Zhang, Yongxue; Teng, Zhongzhao; Lu, Qingsheng; Zhao, Zhiqing; Bao, Junmin; Feng, Xiang; Feng, Rui; Chen, Zengsheng; Huang, Yuan; Sadat, Umar; Gillard, Jonathan H; Jing, Zaiping

    2014-01-01

    Abstract This study sought to report the mid-term outcome of a modified flow-diverting strategy in the treatment of complicated aortic aneurysms of different morphology. Historical data suggested aortic aneurysm expansion and rupture after endovascular treatment with current commercial flow-diverters, indicating the essentiality of further investigation of this technique prior to its large-scale clinical application. An alternative flow-diverting strategy using layer-by-layer assembled multiple overlapping uncovered stents was employed in this study. The treatment outcome in aneurysms of different morphology (saccular, fusiform, and dissecting) was assessed during a mid-term follow-up period. Of 42 patients enrolled in this study (30 male, mean age: 63.3 years), technical success was achieved in 40 cases. During an average follow-up period of 20.9 months, mean aneurysm diameter shrunk from 53.4 ± 13.6 mm to 48.8 ± 13.9 mm (P < 0.001), while stent-induced sac thrombosis ratio increased significantly (18.1 ± 14.9% to 93.6 ± 9.5%, P < 0.001). The majority of side branches (74/76 major visceral branches, 237/244 minor segmental arteries), covered by 3.3 stents on average, maintained their patency after stenting. Saccular aneurysms manifested the highest thrombus deposition speed (18/20 were totally thrombosed within 12 months) and most significant shrinkage (51.4 ± 13.3 mm pre-operatively vs 43.5 ± 10.2 mm during follow-up, P < 0.001) compared with fusiform and dissecting aneurysms. This modified flow-diverting strategy could be a feasible alternative in the management of complicated aortic aneurysms where vital branches need to be preserved. The treatment outcome may depend on the aneurysm type. Further studies with larger patient cohort and longer follow-up are required to substantiate these results. PMID:25501077

  11. A Laser Lock System using Multiple Overlapping Beams

    NASA Astrophysics Data System (ADS)

    Harper, Stuart; Francis, Ben; Erickson, Christopher; Durfee, Dallin

    2010-10-01

    We describe a system wherein the lock of trapping, ionizing, and ion resonance lasers for a Sr experiment are bootstrapped together in a single neutral atom vapor cell. This is done by overlapping beams to optically pump the atoms into the necessary states.

  12. Investigation of Overlap Correction Techniques for Application in the Micro-Pulse Lidar Network (MPLNET)

    NASA Technical Reports Server (NTRS)

    Berkoff, Timothy A.; Welton, Ellsworth J.; Campbell, James R.; Scott, Vibart S.; Spinhirne, James D.

    2003-01-01

    The Micro-Pulse Lidar NETwork (MPLNET) is comprised of micro-pulse lidars (MPL) stationed around the globe to provide measurements of aerosol and cloud vertical distribution on a continuous basis. MPLNET sites are co-located with sunphotometers in the AErosol Robotic NETwork (AERONET) to provide joint measurements of aerosol optical depth, size, and other inherent optical properties. The IPCC 2001 report discusses . the importance of obtaining routine measurements of aerosol vertical structure, especially for absorbing aerosols. MPLNET provides exactly this sort of measurement, including calculation of aerosol extinction profiles, in a near real-time basis for all sites in the network. In order to obtain aerosol profiles, near range signal returns (0-6 km) must be accurately measured by the MPL. This measurement is complicated by the instrument s overlap range: Le., the minimum distance at which returning signals are completely in the instrument s field-of-view (FOV). Typical MPL overlap distances are large, between 5 - 6 km, due to the narrow FOV of the MPL receiver. A function describing the MPL overlap must be determined and used to correct signals in this range. Currently, overlap functions for MPLNET are determined using horizontal MPL measurements along a path with 10-1 5 km clear line-of-sight and a homogenous atmosphere. These conditions limit the location and ease in which successful overlaps can be obtained. Furthermore, the current MPLNET process of correcting for overlap increases the uncertainty and bias error for the near range signals and the resulting aerosol extinction profiles. To address these issues, an alternative overlap correction method using a small-diameter, wide FOV receiver is being considered for potential use in MPLNET. The wide FOV receiver has a much shorter overlap distance and will be used to calculate the overlap function of the MPL receiver. This approach has a significant benefit in that overlap corrections could be obtained

  13. Design of Barker coded multiple pulse experiments

    NASA Astrophysics Data System (ADS)

    Zamlutti, C. J.

    1980-12-01

    The combination of Barker-coded pulse compression techniques with the multiple pulse technique in incoherent scatter studies of the lower ionosphere is discussed. The basic principles of both techniques are reviewed, and the combined technique is presented as consisting of the coding of each pulse of the multiple pulse scheme by a b-baud Barker code. Design considerations for measurements from which the autocorrelation function can be computed are examined for the case of the radar at Arecibo, and possible experiments for observations of sporadic E layers, man-made ionospheric modification and the nighttime E layer are proposed. It is noted that the advantage of the Barker-coded multiple pulse technique consists in the possibility of obtaining simultaneously height and frequency resolution, which is important in the observation of thin layers with narrow frequency spectra.

  14. Multiple-beam pulse shaping and preamplification

    SciTech Connect

    Wilcox, R.B.; VanWonterghem, B.W.; Burkhart, S.C.; Davin, J.M.

    1994-11-09

    Glass fusion laser systems typically use a master oscillator-power amplifier (MOPA) architecture, where control of the optical pulse temporal and spatial parameters is accomplished mainly in the master oscillator and low power optics. The pulses from this low power ``front end`` are amplified in the power amplifier, which modifies the pulse shape temporally and spatially. Nonlinear frequency conversion crystals following the amplifier further change the pulse before it reaches the target. To effectively control the optical pulse on target for different types of experiments, and compensate for nonlinearity in the preceding optics, the front end system must be versatile enough to easily control many pulse parameters over a large range. The front end pulse generation system described in this article represents a new approach to this problem. The proposed National Ignition Facility (NIF) has 192 beamlines, each of which requires an input pulse of up to 12 Joules in around 4 ns equivalent square pulse length. Considerations of laser architecture for supplying each of these beamlines from a central oscillator system were crucial in the design of the front end. Previous lasers have used bulk optics to split a single oscillator signal and report beams to multiple amplifier chains. A key idea in the current design is to replace bulk optic transport with fibers, eliminating large opto-mechanical subsystems. Another important concept is convenient pulse forming using low voltage integrated optic modulators. The integrated optic and fiber optic concepts resulted in the current pulse generation designs for NEF. An important advantage is that each of the beamlines can have an independently controlled temporal pulse shape, which provides for precise balance of instantaneous power on target.

  15. Experimental Results for Temporally Overlapping Pulses from Quantel EverGreen 200 Laser

    NASA Technical Reports Server (NTRS)

    Watkins, A. Neal

    2013-01-01

    This report will detail the experimental results and observations obtained while investigating the feasibility of temporally overlapping the two laser pulses from a Quantel EverGreen 200 Laser. This laser was specifically designed for Particle Imaging Velocimetry (PIV) applications and operate by emitting two 532 nm laser pulses that are seperated by an adjustable finite time (typically on the order of ten to hundreds of microseconds). However, the use of this model laser has found recent application for Pressure Sensitive Paint (PSP) testing, especially for rotorcraft research. For this testing, it is desired to only use one laser pulse. While this is easily done by only firing one of the laser heads, more excitation energy could conceivably be had if both laser heads are fired with zero pulse separation. In addition, recently large field-of-view PIV measurements have become possible and need ever increasing laser power to illuminate the larger areas. For this work, two different methods of timing the laser are investigated using both a traditional power meter to monitor laser power as well as a fast photodiode to determine pulse separation. The results are presented here as well as some simple implications for PIV experiments using these methods.

  16. On the Performance of Multiple Pulse Multiple Delay UWB Modulation

    SciTech Connect

    Nekoogar, F; Dowla, F U

    2003-05-23

    Multiple access (MA) in UWB communication is an area of active research. In this paper we introduce and study the performance of a new MA scheme in the context of multiple transmitted-reference short duration (nsec) chirp pulses in the presence of additive white Gaussian noise (AWGN). The transmitted-reference (T-R) receiver is extended using multiple orthogonal pulses. The proposed UWB receiver samples the receiver autocorrelation function (ACF) at both zero- and non-zero lags, thus sampling and matching the shape of ACFs rather than just the shape of the received pulses. Sampling of non-zero ACF lags is a significant new approach. The scheme proposed in this paper is a step towards combining the multi-pulse approach and T-R modulation in a multiple access ultra wideband (MA-UWB) communications system. Improved bit error rate performance over a conventional zero-lag receiver (i.e. energy detection receiver) is demonstrated by simulation. Analytical expressions for the system BER are also derived and confirmed through simulations for the system.

  17. Integrated defense system overlaps as a disease model: with examples for multiple chemical sensitivity.

    PubMed Central

    Rowat, S C

    1998-01-01

    The central nervous, immune, and endocrine systems communicate through multiple common messengers. Over evolutionary time, what may be termed integrated defense system(s) (IDS) have developed to coordinate these communications for specific contexts; these include the stress response, acute-phase response, nonspecific immune response, immune response to antigen, kindling, tolerance, time-dependent sensitization, neurogenic switching, and traumatic dissociation (TD). These IDSs are described and their overlap is examined. Three models of disease production are generated: damage, in which IDSs function incorrectly; inadequate/inappropriate, in which IDS response is outstripped by a changing context; and evolving/learning, in which the IDS learned response to a context is deemed pathologic. Mechanisms of multiple chemical sensitivity (MCS) are developed from several IDS disease models. Model 1A is pesticide damage to the central nervous system, overlapping with body chemical burdens, TD, and chronic zinc deficiency; model 1B is benzene disruption of interleukin-1, overlapping with childhood developmental windows and hapten-antigenic spreading; and model 1C is autoimmunity to immunoglobulin-G (IgG), overlapping with spreading to other IgG-inducers, sudden spreading of inciters, and food-contaminating chemicals. Model 2A is chemical and stress overload, including comparison with the susceptibility/sensitization/triggering/spreading model; model 2B is genetic mercury allergy, overlapping with: heavy metals/zinc displacement and childhood/gestational mercury exposures; and model 3 is MCS as evolution and learning. Remarks are offered on current MCS research. Problems with clinical measurement are suggested on the basis of IDS models. Large-sample patient self-report epidemiology is described as an alternative or addition to clinical biomarker and animal testing. Images Figure 1 Figure 2 Figure 3 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:9539008

  18. MELTING OF GLASS BATCH: MODEL FOR MULTIPLE OVERLAPPING GAS-EVOLVING REACTIONS

    SciTech Connect

    Pokorny, Richard; Pierce, David A.; Hrma, Pavel R.

    2012-08-10

    In this study, we present a model for the kinetics of multiple overlapping reactions. Mathematical representation of the kinetics of gas-evolving reactions is crucial for the modeling of the feed-to-glass conversion in a waste-glass melter. The model simulates multiple gas-evolving reactions that occur during heating of a high-alumina high-level waste melter feed. To obtain satisfactory kinetic parameters, we employed Kissinger's method combined with least-squares analysis. The power-law kinetics with variable reaction order sufficed for obtaining excellent agreement with measured thermogravimetric analysis data.

  19. MELTING OF GLASS BATCH - MODEL FOR MULTIPLE OVERLAPPING GAS-EVOLVING REACTIONS

    SciTech Connect

    KRUGER AA; PIERCE DA; POKORNY R; HRMA PR

    2012-02-07

    In this study, we present a model for the kinetics of multiple overlapping reactions. Mathematical representation of the kinetics of gas-evolving reactions is crucial for the modeling of the feed-to-glass conversion in a waste-glass melter. The model simulates multiple gas-evolving reactions that occur during heating of a high-alumina high-level waste melter feed. To obtain satisfactory kinetic parameters, we employed Kissinger's method combined with least-squares analysis. The power-law kinetics with variable reaction order sufficed for obtaining excellent agreement with measured thermogravimetric analysis data.

  20. Professional boundaries and the ethics of dual and multiple overlapping relationships in psychotherapy.

    PubMed

    Crowden, Andrew

    2008-10-01

    The moral status of professional boundaries and the ethical nature of dual and multiple overlapping human relationships in contemporary clinical practice remain enduring problems in all health care disciplines. In this paper I explore the ethics of dual or multiple overlapping relationship and apply a virtue ethics framework to the case of psychotherapy. After clarifying the context and meaning of commonly used terminology, and considering what some of the key Australian codes of ethics relevant to psychotherapy advise about dual relationships, I identify some commonly occurring situations where overlapping relationships are unavoidable. A case study from a rural context where size, isolation, and community expectations profoundly impact on the capacity of a psychotherapist to maintain clearly defined professional therapeutic relationship boundaries is analysed. The rural example is pertinent. A virtue ethics approach goes some way toward alleviating perceptions about the nature of dual relationships that contribute to an enduring reticence amongst psychotherapists (and other professionals) to practice in rural settings. Clearly, if a dual relationship involves exploitation then that relationship is a boundary crossing that should rightly be categorised as a boundary violation. Boundary violations are exploitative and unethical. However, some dual relationships may involve boundary crossings that are not necessarily boundary violations. Despite their general prohibition by Australian (and many other countries') codes of ethics relevant to psychotherapy, I argue that in certain situations, if a psychotherapist (who crosses a professional relationship boundary) acts with professional integrity from the distinct professional role-related virtues and/or regulative ideals that ensure the goals of psychotherapy (to increase autonomy and psychological wellbeing) are met, then a dual or multiple overlapping relationship in psychotherapy will be ethical.

  1. Ultrashort pulse propagation in multiple-grating fiber structures.

    PubMed

    Chen, L R; Benjamin, S D; Smith, P W; Sipe, J E; Juma, S

    1997-03-15

    We propose a multiple-grating fiber structure that decomposes an ultrashort broadband optical pulse simultaneously in both wavelength and time. As an initial demonstration, we used a transform-limited 1-ps Gaussian pulse centered at 1.55 mu;m as the ultrashort broadband input into a three-grating fiber structure and generated three output pulses separated in wavelength and time with good correlation between experimental results and simulations. This device structure can be used to generate a multiwavelength train of pulses for use in wavelength-division-multiplexed systems or to implement frequency-domain encoding of coherent pulses for optical code-division multiple access.

  2. Separating overlapping click trains originating from multiple individuals in echolocation recordings.

    PubMed

    Starkhammar, Josefin; Nilsson, Johan; Amundin, Mats; Kuczaj, Stan A; Almqvist, Monica; Persson, Hans W

    2011-01-01

    Recordings of the acoustic activity of free-swimming groups of echolocating dolphins increase the likelihood of collecting overlapping click trains, originating from multiple individuals, in the same set of data. In order to evaluate the click properties of each individual based on such recordings it is necessary to identify which clicks originate from which animal. This paper suggests a computationally efficient strategy to separate overlapping click trains originating from multiple free-swimming bottlenose dolphins, enabling echolocation analysis at an individual level on several animals. This technique is based on sequential matching of the frequency spectra of successive clicks. The clicks are grouped together as individual click trains if the correlation coefficients between clicks are higher than a pre-set threshold level. The robustness of the algorithm is tested by adding artificially generated white Gaussian noise and comparing the results with other comparable commonly used methods based on inter-click intervals, centroid frequencies, and amplitude levels. The described method is applicable to a variety of experimental and observational contexts, e.g., those regarding echolocation development of calves, the hypothesized acoustic "etiquette" among dolphins when investigating the same object, and the possible occurrence of eavesdropping in large dolphin pods. PMID:21303025

  3. Multiple pulse thresholds in live eyes for ultrashort laser pulses in the near infrared

    NASA Astrophysics Data System (ADS)

    Stolarski, David J.; Cain, Clarence P.; Toth, Cynthia A.; Noojin, Gary D.; Rockwell, Benjamin A.

    1999-06-01

    Damage thresholds using multiple laser pulses to produce minimum visible lesions (MVL) in rhesus monkey eyes are reported for near-infrared (800 nm) at 130 femtoseconds. Previous studies by our research group using single pulses in the near-infrared (1060 nm) have determined damage thresholds and retinal spot size dependence. We report the first multiple pulse damage thresholds using femtosecond pulses. MVL thresholds at 1 hour and 24 hours postexposure were determined for 1, 100 and 1,000 pulses and we compare these with other reported multiple pulse thresholds. These new data will be added to the databank for retinal MVL's as a function of pulse repetition rate for this pulsewidth and a comparison will be made with the ANSI standard for multiple pulse exposures. Our measurements show that the retinal ED50 threshold/pulse in the paramacula decreases for increasing number of pulses. The MVL-ED50 at the threshold/pulse decreased by a factor of 4 (0.55 (mu) J to 0.13 (mu) J/pulse) for an increase from 1 to 100 pulses.

  4. [A case of clinical overlap syndrome of rheumatoid arthritis and amyopathic dermatomyositis with multiple pulmonary injuries].

    PubMed

    Liu, Shuang; An, Yuan; Jia, Yuan; Li, Zhan-guo

    2014-10-18

    Autoimmune diseases can cause various kinds of lung injuries. Clinical features of a case of overlap syndrome with multiple pulmonary injuries were investigated, and the treatment experiences discussed. The patient suffered from rheumatoid arthritis (RA) at first, and then had a lobectomy surgery due to the rheumatoid nodules in her right lung. A year later her disease was diagnosed as amyopathic dermatomyositis (ADM) with typical Gottron's sign, craftsmen hands and rapid-progressive organizing pneumonia (OP). After a combined treatment with glucocorticoids (GCs) and cyclophosphamide (CTX), her OP became better but lung infections progressed. Her lung infections eventually were cured after we used antibiotics and antifungal treatment while we ceased to use CTX and reduced the dosage of GCs. The clinical feature of the patient was overlap syndrome with a variety of lung injuries, such as pulmonary rheumatoid nodules, OP, secondary bronchopleural fistula and lung infections. Its diagnosis and treatment experiences could improve our understanding of pulmonary manifestations of connective tissue disease and improve our diagnosis and treatment level.

  5. Fast ion profile stiffness due to the resonance overlap of multiple Alfvén eigenmodes

    NASA Astrophysics Data System (ADS)

    Todo, Y.; Van Zeeland, M. A.; Heidbrink, W. W.

    2016-11-01

    Fast ion pressure profiles flattened by multiple Alfvén eigenmodes (AEs) are investigated for various neutral beam deposition powers in a multi-phase simulation, which is a combination of classical simulation and hybrid simulation for energetic particles interacting with a magnetohydrodynamic fluid. Monotonic degradation of fast ion confinement and fast ion profile stiffness is found with increasing beam deposition power. The confinement degradation and profile stiffness are caused by a sudden increase in fast ion transport flux brought about by AEs for fast ion pressure gradients above a critical value. The critical pressure gradient and the corresponding beam deposition power depend on the radial location. The fast ion pressure gradient stays moderately above the critical value, and the profiles of the fast ion pressure and fast ion transport flux spread radially outward from the inner region, where the beam is injected. It is found that the square root of the MHD fluctuation energy is proportional to the beam deposition power. Analysis of the time evolutions of the fast ion energy flux profiles reveals that intermittent avalanches take place with contributions from the multiple eigenmodes. Surface of section plots demonstrate that the resonance overlap of multiple eigenmodes accounts for the sudden increase in fast ion transport with increasing beam power. The critical gradient and critical beam power for the profile stiffness are substantially higher than the marginal stability threshold.

  6. Multiple laser pulse ignition method and apparatus

    DOEpatents

    Early, James W.

    1998-01-01

    Two or more laser light pulses with certain differing temporal lengths and peak pulse powers can be employed sequentially to regulate the rate and duration of laser energy delivery to fuel mixtures, thereby improving fuel ignition performance over a wide range of fuel parameters such as fuel/oxidizer ratios, fuel droplet size, number density and velocity within a fuel aerosol, and initial fuel temperatures.

  7. Controlling Test Overlap Rate in Automated Assembly of Multiple Equivalent Test Forms

    ERIC Educational Resources Information Center

    Lin, Chuan-Ju

    2010-01-01

    Assembling equivalent test forms with minimal test overlap across forms is important in ensuring test security. Chen and Lei (2009) suggested a exposure control technique to control test overlap-ordered item pooling on the fly based on the essence that test overlap rate--ordered item pooling for the first t examinees is a function of test overlap…

  8. 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.

  9. Extrinsic self-calibration of multiple cameras with non-overlapping views in vehicles

    NASA Astrophysics Data System (ADS)

    Pagel, Frank

    2014-03-01

    Due to decreasing sensor prices and increasing processing performance, the use of multiple cameras in vehicles becomes an attractive possibility for environment perception. This contribution focuses on non-overlapping multi-camera configurations on a mobile platform and its purely vision-based self-calibration as well as its restrictions. The usage of corresponding features between the cameras is very difficult to realize and likely to fail due to different appearances in different views and motion-dependent time delays. Instead, the hand-eye calibration (HEC) technique based on visual odometry is considered to solve this problem by exploiting the cameras motions. For that purpose, this contribution presents an approach to continuously calibrate cameras by making use of the so-called motion adjustment (MA) and an IEKF. Visual odometry in driving vehicles often struggles in estimating the relative magnitudes of the translational motion, which is crucial for the HEC. So, MA simultaneously estimates the extrinsic parameters up to scale as well as the relative motion magnitudes. Furthermore, the estimation process is embedded into a global fusion framework to benefit from the redundant information resulting from multiple cameras in order to yield more robust results. This paper presents results with simulated and real data.

  10. Multiple pulse resonantly enhanced laser plasma wakefield acceleration

    SciTech Connect

    Corner, L.; Walczak, R.; Nevay, L. J.; Dann, S.; Hooker, S. M.; Bourgeois, N.; Cowley, J.

    2012-12-21

    We present an outline of experiments being conducted at Oxford University on multiple-pulse, resonantly-enhanced laser plasma wakefield acceleration. This method of laser plasma acceleration uses trains of optimally spaced low energy short pulses to drive plasma oscillations and may enable laser plasma accelerators to be driven by compact and efficient fibre laser sources operating at high repetition rates.

  11. Electric field in an AC dielectric barrier discharge overlapped with a nanosecond pulse discharge

    NASA Astrophysics Data System (ADS)

    Goldberg, Benjamin M.; Shkurenkov, Ivan; Adamovich, Igor V.; Lempert, Walter R.

    2016-08-01

    The effect of ns discharge pulses on the AC barrier discharge in hydrogen in plane-to-plane geometry is studied using time-resolved measurements of the electric field in the plasma. The AC discharge was operated at a pressure of 300 Torr at frequencies of 500 and 1750 Hz, with ns pulses generated when the AC voltage was near zero. The electric field vector is measured by ps four-wave mixing technique, which generates coherent IR signal proportional to the square of electric field. Absolute calibration was done using an electrostatic (sub-breakdown) field applied to the discharge electrodes, when no plasma was generated. The results are compared with one-dimensional kinetic modeling of the AC discharge and the nanosecond pulse discharge, predicting behavior of both individual micro-discharges and their cumulative effect on the electric field distribution in the electrode gap, using stochastic averaging based on the experimental micro-discharge temporal probability distribution during the AC period. Time evolution of the electric field in the AC discharge without ns pulses, controlled by a superposition of random micro-discharges, exhibits a nearly ‘flat top’ distribution with the maximum near breakdown threshold, reproduced quite well by kinetic modeling. Adding ns pulse discharges on top of the AC voltage waveform changes the AC discharge behavior in a dramatic way, inducing transition from random micro-discharges to a more regular, near-1D discharge. In this case, reproducible volumetric AC breakdown is produced at a well-defined moment after each ns pulse discharge. During the reproducible AC breakdown, the electric field in the plasma exhibits a sudden drop, which coincides in time with a well-defined current pulse. This trend is also predicted by the kinetic model. Analysis of kinetic modeling predictions shows that this effect is caused by large-volume ionization and neutralization of surface charges on the dielectrics by ns discharge pulses. The present

  12. The multiple-pulse driver line on the OMEGA laser

    NASA Astrophysics Data System (ADS)

    Kosc, T. Z.; Kelly, J. H.; Hill, E. M.; Dorrer, C.; Waxer, L. J.; Donaldson, W. R.

    2015-02-01

    The multiple-pulse driver line (MPD) provides on-shot co-propagation of two separate pulse shapes in all 60 OMEGA beams at the Laboratory for Laser Energetics (LLE). The two co-propagating pulse shapes would typically be (1) a series of 100-ps "picket" pulses followed by (2) a longer square or shaped "drive" pulse. Smoothing by spectral dispersion (SSD), which increases the laser bandwidth, can be applied to either one of the two pulse shapes. Therefore, MPD allows for dynamic bandwidth reduction, where the bandwidth is applied only to the picket portion of a pulse shape. Since the use of SSD decreases the efficiency of frequency conversion from the IR to the UV, dynamic bandwidth reduction provides an increase in the drive-pulse energy. The design of the MPD required careful consideration of beam combination as well as the minimum pulse separation for two pulses generated by two separate sources. A new combined-pulse-shape diagnostic needed to be designed and installed after the last grating used for SSD. This new driver-line flexibility is built into the OMEGA front end as one component of the initiative to mitigate cross-beam energy transfer on target and to demonstrate hydro-equivalent ignition on the OMEGA laser at LLE.

  13. Numerical analysis of laser ablation and damage in glass with multiple picosecond laser pulses.

    PubMed

    Sun, Mingying; Eppelt, Urs; Russ, Simone; Hartmann, Claudia; Siebert, Christof; Zhu, Jianqiang; Schulz, Wolfgang

    2013-04-01

    This study presents a novel numerical model for laser ablation and laser damage in glass including beam propagation and nonlinear absorption of multiple incident ultrashort laser pulses. The laser ablation and damage in the glass cutting process with a picosecond pulsed laser was studied. The numerical results were in good agreement with our experimental observations, thereby revealing the damage mechanism induced by laser ablation. Beam propagation effects such as interference, diffraction and refraction, play a major role in the evolution of the crater structure and the damage region. There are three different damage regions, a thin layer and two different kinds of spikes. Moreover, the electronic damage mechanism was verified and distinguished from heat modification using the experimental results with different pulse spatial overlaps.

  14. Optodynamic study of multiple pulses micro drilling.

    PubMed

    Petkovsek, Rok; Panjan, Igor; Babnik, Ales; Mozina, Janez

    2006-12-22

    This paper describes an analysis of pulsed lasers micro-drilling of different metals. Study focuses to an optodynamic phenomenon which appears as thermal effects induced by laser light pulses and leads to dynamic process manifested as ultrasonic shock waves propagating into the sample material. The shock waves are detected by a non-contact optical method by using arm compensated Michelson. Monitoring of the main parameters of the micro drilling such as material ablation rate and efficiency was realized by analysis of the optodynamic signals. The process is characterized by decreasing ablation rate that leads to the finite hole depth. The experimental part of study comprehends a comparison between various metals. In order to describe decreasing ablation rate a theoretical model based on the energy balance is proposed. It considers the energy/heat transfer from the laser beam to the material and predicts a decreasing drilling rate with an increasing number of successive laser pulses. According to the proposed model, the finite depth of the hole appears as a consequence of the increasing surface area through which the energy of the laser beam is conducted away to the material around the processed area. Decreasing ablation rate and the finite hole depth predicted by model were in good agreement with the experimental results. PMID:16793092

  15. Laser Pulse-Stretching Using Multiple Optical Ring-Cavities

    NASA Technical Reports Server (NTRS)

    Kojima, Jun; Nguyen, Quang-Viet; Lee, Chi-Ming (Technical Monitor)

    2002-01-01

    We describe a simple and passive nanosecond-long (ns-long) laser 'pulse-stretcher' using multiple optical ring-cavities. We present a model of the pulse-stretching process for an arbitrary number of optical ring-cavities. Using the model, we optimize the design of a pulse-stretcher for use in a spontaneous Raman scattering excitation system that avoids laser-induced plasma spark problems. From the optimized design, we then experimentally demonstrate and verify the model with a 3-cavity pulse-stretcher system that converts a 1000 mJ, 8.4 ns-long input laser pulse into an approximately 75 ns-long (FWHM) output laser pulse with a peak power reduction of 0.10X, and an 83% efficiency.

  16. A Novel 3D Building Damage Detection Method Using Multiple Overlapping UAV Images

    NASA Astrophysics Data System (ADS)

    Sui, H.; Tu, J.; Song, Z.; Chen, G.; Li, Q.

    2014-09-01

    In this paper, a novel approach is presented that applies multiple overlapping UAV imagesto building damage detection. Traditional building damage detection method focus on 2D changes detection (i.e., those only in image appearance), whereas the 2D information delivered by the images is often not sufficient and accurate when dealing with building damage detection. Therefore the detection of building damage in 3D feature of scenes is desired. The key idea of 3D building damage detection is the 3D Change Detection using 3D point cloud obtained from aerial images through Structure from motion (SFM) techniques. The approach of building damage detection discussed in this paper not only uses the height changes of 3D feature of scene but also utilizes the image's shape and texture feature. Therefore, this method fully combines the 2D and 3D information of the real world to detect the building damage. The results, tested through field study, demonstrate that this method is feasible and effective in building damage detection. It has also shown that the proposed method is easily applicable and suited well for rapid damage assessment after natural disasters.

  17. Performance of Multiple Pulse Multiple Delay Modulated UWB Signals in a Multiple Access Indoor Wireless Channel

    SciTech Connect

    Nekoogar, F

    2003-06-12

    In this paper, the performance of a two user UWB multiple access (UWB-MA) system based on multiple-pulse multiple-delay (MPMD) modulation scheme in an indoor wireless channel is evaluated by computer simulations. The indoor multipath propagation channel model used in this study is based on the modified statistical Saleh-Valenzuela model proposed by Foerester and Li from Intel. The simulation results indicate that the multipath performance of MPMD modulated signals in a multiple access system outperforms the nonmultipath case as the number of autocorrelation function (ACF) sampling points increases for each user. This is an unusual but important result, since MPMD receiver exploits multipath phenomenon in indoor wireless channels to increase the BER performance, hence the transmission rate in a UWB-MA system.

  18. Multiple Contingency Table Analyses of the Deviance Syndrome: How Much Overlap Is There?

    ERIC Educational Resources Information Center

    Corwyn, Robert Flynn; Benda, Brent B.

    1999-01-01

    Surveys adolescents (N=1,621) attending southern, metropolitan secondary schools to determine how much overlap there is in individuals who smoke, get drunk, use marijuana, and have sexual intercourse; and determine if overlap is according to age, gender, race, and family structure. Reports there are relationships between activities, although most…

  19. Microgenetic Patterns of Children's Multiplication Learning: Confirming the Overlapping Waves Model by Latent Growth Modeling

    ERIC Educational Resources Information Center

    van der Ven, Sanne H. G.; Boom, Jan; Kroesbergen, Evelyn H.; Leseman, Paul P. M.

    2012-01-01

    Variability in strategy selection is an important characteristic of learning new skills such as mathematical skills. Strategies gradually come and go during this development. In 1996, Siegler described this phenomenon as ''overlapping waves.'' In the current microgenetic study, we attempted to model these overlapping waves statistically. In…

  20. Multiple-Coil, Pulse-Induction Metal Detector

    NASA Technical Reports Server (NTRS)

    Lesky, Edward S.; Reid, Alan M.; Bushong, Wilton E.; Dickey, Duane P.

    1988-01-01

    Multiple-head, pulse-induction metal detector scans area of 72 feet squared with combination of eight detector heads, each 3 ft. square. Head includes large primary coil inducing current in smaller secondary coils. Array of eight heads enables searcher to cover large area quickly. Pulses applied to primary coil, induced in secondary coils measured to determine whether metal present within range of detector head. Detector designed for recovery of Space Shuttle debris.

  1. Super-Resolution Enhancement From Multiple Overlapping Images: A Fractional Area Technique

    NASA Astrophysics Data System (ADS)

    Michaels, Joshua A.

    With the availability of large quantities of relatively low-resolution data from several decades of space borne imaging, methods of creating an accurate, higher-resolution image from the multiple lower-resolution images (i.e. super-resolution), have been developed almost since such imagery has been around. The fractional-area super-resolution technique developed in this thesis has never before been documented. Satellite orbits, like Landsat, have a quantifiable variation, which means each image is not centered on the exact same spot more than once and the overlapping information from these multiple images may be used for super-resolution enhancement. By splitting a single initial pixel into many smaller, desired pixels, a relationship can be created between them using the ratio of the area within the initial pixel. The ideal goal for this technique is to obtain smaller pixels with exact values and no error, yielding a better potential result than those methods that yield interpolated pixel values with consequential loss of spatial resolution. A Fortran 95 program was developed to perform all calculations associated with the fractional-area super-resolution technique. The fractional areas are calculated using traditional trigonometry and coordinate geometry and Linear Algebra Package (LAPACK; Anderson et al., 1999) is used to solve for the higher-resolution pixel values. In order to demonstrate proof-of-concept, a synthetic dataset was created using the intrinsic Fortran random number generator and Adobe Illustrator CS4 (for geometry). To test the real-life application, digital pictures from a Sony DSC-S600 digital point-and-shoot camera with a tripod were taken of a large US geological map under fluorescent lighting. While the fractional-area super-resolution technique works in perfect synthetic conditions, it did not successfully produce a reasonable or consistent solution in the digital photograph enhancement test. The prohibitive amount of processing time (up to

  2. Multiple THz pulse generation with variable energy ratio and delay

    NASA Astrophysics Data System (ADS)

    Ungureanu, R. G.; Grigore, O. V.; Dinca, M. P.; Cojocaru, G. V.; Ursescu, D.; Dascalu, T.

    2015-04-01

    Two methods for multiple high energetic THz pulse generation by two-color filamentation in air with controllable energy ratio and delay ranging from one to hundreds of ps were investigated. In the first method the laser pulse is split into two inside the optical stretcher of a CPA laser system, the resulting consecutive filaments occur in the same region and allows the study of the influence of the first plasma filament on the THz emission of the delayed filament. Based on a polarization sensitive thin film beam splitter placed in front of a 45° mirror, the second method produces multiple parallel consecutive filaments. Above a certain total pump level the THz energy delivered by multiple pulses exceeds the value given by a single filament for the same pump energy, thereby overcoming the THz emission saturation of the single filament.

  3. NOTE: Modelling multiple laser pulses for port wine stain treatment

    NASA Astrophysics Data System (ADS)

    Verkruysse, Wim; van Gemert, Martin J. C.; Smithies, Derek J.; Nelson, J. Stuart

    2000-12-01

    Many port wine stains (PWS) are still resistant to pulsed dye laser treatment. However, anecdotal information suggests that multiple-pulse laser irradiation improves patient outcome. Our aims in this note are to explain the underlying mechanism and estimate the possible thermal effects of multiple pulses in vascular structures typical of PWS. Based on linear response theory, the linear combination of two thermal contributions is responsible for the total increase in temperature in laser irradiated blood vessels: direct light absorption by blood and direct bilateral thermal heat conduction from adjacent blood vessels. The latter contribution to the increase in temperature in the targeted vessel can be significant, particularly if some adjacent vessels are in close proximity, such as in cases of optical shielding of the targeted vessel, or if the vessels are relatively distant but many in number. We present evidence that multiple-pulse laser irradiation targets blood vessels that are optically shielded by other vessels. Therefore, it may be a means of enhancing PWS therapy for lesions that fail to respond to single-pulse dye laser treatment.

  4. Temporal laser pulse manipulation using multiple optical ring-cavities

    NASA Technical Reports Server (NTRS)

    Nguyen, Quang-Viet (Inventor); Kojima, Jun (Inventor)

    2010-01-01

    An optical pulse stretcher and a mathematical algorithm for the detailed calculation of its design and performance is disclosed. The optical pulse stretcher has a plurality of optical cavities, having multiple optical reflectors such that an optical path length in each of the optical cavities is different. The optical pulse stretcher also has a plurality of beam splitters, each of which intercepts a portion of an input optical beam and diverts the portion into one of the plurality of optical cavities. The input optical beam is stretched and a power of an output beam is reduced after passing through the optical pulse stretcher and the placement of the plurality of optical cavities and beam splitters is optimized through a model that takes into account optical beam divergence and alignment in the pluralities of the optical cavities. The optical pulse stretcher system can also function as a high-repetition-rate (MHz) laser pulse generator, making it suitable for use as a stroboscopic light source for high speed ballistic projectile imaging studies, or it can be used for high speed flow diagnostics using a laser light sheet with digital particle imaging velocimetry. The optical pulse stretcher system can also be implemented using fiber optic components to realize a rugged and compact optical system that is alignment free and easy to use.

  5. A Study on Marker Overlapping Control for M2M-Based Augmented Reality Multiple Object Loading Using Bresenham Algorithm

    NASA Astrophysics Data System (ADS)

    Jung, Sungmo; Song, Jae-Gu; Kim, Seoksoo

    The problem of one marker one object loading only available in marker-based augmented reality technology can be solved by PPHT-based augmented reality multiple objects loading technology which detects the same marker in the image and copies at a desirable location. However, since the distance between markers will not be measured in the process of detecting and copying markers, markers can be overlapped and thus the objects would not be augmented. To solve this problem, a circle having the longest radius needs to be created from a focal point of a marker to be copied, so that no object is copied within the confines of the circle. Therefore, a marker overlapping control for M2M-based augmented reality multiple object loading has been studied using Bresenham algorithm.

  6. Effect of the overlapping factor on the microstructure and mechanical properties of pulsed Nd:YAG laser welded Ti6Al4V sheets

    SciTech Connect

    Gao, Xiao-Long; Liu, Jing; Zhang, Lin-Jie Zhang, Jian-Xun

    2014-07-01

    The effect of the overlapping factor on the microstructures and mechanical properties of pulsed Nd:YAG laser welded Ti6Al4V alloy sheets was investigated by microstructural observations, microhardness tests, tensile tests and fatigue tests. A microstructural examination shows that by increasing the overlapping factor, the grains in the fusion zone become coarser, and the width of the heat affected zone increases. As overlapping factor increases, the width of region composed completely of martensite α′ and the secondary α phase in the heat affected zone increases, consequently the gradient of microstructure along the direction from the fusion zone to base metal decreases, so does the gradient of microhardness. The results of tensile and fatigue tests reveal that the joints made using medium overlapping factor exhibit better mechanical properties than those welded with low and high overlapping factors. Based on the experimental results, it can be stated that a sound weld of Ti6Al4V alloy can be obtained if an appropriate overlapping factor is used. - Highlights: • The weld quality of Ti6Al4V alloy under various overlapping factors was assessed. • Tensile and fatigue tests were conducted with as-welded specimen. • Localized strain across the weld was measured using DIC photogrammetry system. • A sound weld of Ti6Al4V alloy is obtained by using right overlapping factor.

  7. Multiple filamentation Ti:Sapphire-laser pulses in water

    NASA Astrophysics Data System (ADS)

    Apeksimov, D. V.; Bukin, O. A.; Golik, S. S.; Zemlyanov, A. A.; Kabanov, A. M.; Kuchinskaya, O. I.; Mayor, A. Yu.; Matvienko, G. G.; Petrov, A. V.; Sokolova, E. B.

    2015-11-01

    The results of experimental studies of the spatial characteristics of multiple filamentation terawatt femtosecond Ti:Salaser in water are presented. With an increase in initial power laser pulses increases the number of filaments, the length of the field is increased filamentation and reducing the length of the filaments have been shown. The distribution of the filaments in the longitudinal direction of the field of multiple filamentation has a maximum cross-sectional filament is shifted from the center to the periphery of the beam at the end region of filamentation. The minimum diameter of the beam on the track corresponds to the position of the maximum number of filaments. After the point of maximum impulse essentially loses energy in the initial direction of propagation. Upon reaching the pulse power 2 104 Pcr of multiple filamentation area is formed of a hollow cone, the apex directed to the radiation source.

  8. Automatic detection of multiple and overlapping EP catheters in fluoroscopic sequences.

    PubMed

    Milletari, Fausto; Navab, Nassir; Fallavollita, Pascal

    2013-01-01

    We propose a method to perform automatic detection of electrophysiology (EP) catheters in fluoroscopic sequences. Our approach does not need any initialization, is completely automatic, and can detect an arbitrary number of catheters at the same time. The method is based on the usage of blob detectors and clustering in order to detect all catheter electrodes, overlapping or not, within the X-ray images. The proposed technique is validated on 1422 fluoroscopic images yielding a tip detection rate of 99.3% and mean distance of 0.5mm from manually labeled ground truth centroids for all electrodes. PMID:24505783

  9. Dose rate effect on micronuclei induction in human blood lymphocytes exposed to single pulse and multiple pulses of electrons.

    PubMed

    Acharya, Santhosh; Bhat, N N; Joseph, Praveen; Sanjeev, Ganesh; Sreedevi, B; Narayana, Y

    2011-05-01

    The effects of single pulses and multiple pulses of 7 MV electrons on micronuclei (MN) induction in cytokinesis-blocked human peripheral blood lymphocytes (PBLs) were investigated over a wide range of dose rates per pulse (instantaneous dose rate). PBLs were exposed to graded doses of 2, 3, 4, 6, and 8 Gy of single electron pulses of varying pulse widths at different dose rates per pulse, ranging from 1 × 10(6) Gy s(-1) to 3.2 × 10(8) Gy s(-1). Different dose rates per pulse were achieved by changing the dose per electron pulse by adjusting the beam current and pulse width. MN yields per unit absorbed dose after irradiation with single electron pulses were compared with those of multiple pulses of electrons. A significant decrease in the MN yield with increasing dose rates per pulse was observed, when dose was delivered by a single electron pulse. However, no reduction in the MN yield was observed when dose was delivered by multiple pulses of electrons. The decrease in the yield at high dose rates per pulse suggests possible radical recombination, which leads to decreased biological damage. Cellular response to the presence of very large numbers of chromosomal breaks may also alter the damage.

  10. Extraction of quadrature phase information from multiple pulse NMR signals

    NASA Technical Reports Server (NTRS)

    Rhim, W.-K.; Burum, D. P.; Vaughan, R. W.

    1976-01-01

    A multiple pulse sequence (8-pulse sequence) used for high-resolution solid state NMR is analyzed with regard to the information available from each of the four wide sampling windows. It is demonstrated that full quadrature phase information can be obtained using only a single phase detector and that, for the commonly encountered situation where the spectral width is much less than the folding frequency, the signals from the various windows can be combined easily using standard complex Fourier transform software. An improvement in the signal-to-noise ratio equal to the square root of 3 is obtained over either standard single or quadrature phase detection schemes. Procedures for correcting spectral distortions are presented.

  11. Multiple Pulses from Plasma Jets onto Liquid Covered Tissue

    NASA Astrophysics Data System (ADS)

    Norberg, Seth; Tian, Wei; Johnsen, Eric; Kushner, Mark J.

    2014-10-01

    Atmospheric pressure plasma jets are being studied in the treatment of biological surfaces that are often covered by a thin layer of liquid. The plume of the plasma jet contains neutral radicals and charged species that solvate into the liquid and eventually form terminal species that reach the tissue below. The contribution of neutral and charged species to reactivity in the liquid is sensitive to whether the active plasma plume touches the liquid. In this paper, we discuss results from modeling the production of the aqueous species formed from the interaction of the plume of plasma jets over multiple pulses with the water layer, and the fluences of the species to the underlying tissue. The model used in this study, nonPDPSIM, solves transport equations for charged and neutral species and electron energy, Poisson's equation for the electric potential, and Navier-Stokes equations for the neutral gas flow. Radiation transport includes photoionization of O2 and H2O in the gas and liquid phases and photodissocation of H2Oaq in the liquid. Multiple pulses when the plasma plume touches and does not touch the liquid will be examined. Two regimes of hydrodynamics will be discussed - low repetition rates where the neutral radicals are blown away before the next discharge pulse, and high repetition rate when the plasma plume interacts with neutral radicals from previous pulses. The density of aqueous ions produced in the liquid layer is strongly dependent on whether the plasma effluent touches or does not touch the water surface. Work supported by DOE Office of Fusion Energy Science and NSF.

  12. The Twenty-First Century Multiple Generation Workforce: Overlaps and Differences but Also Challenges and Benefits

    ERIC Educational Resources Information Center

    Helyer, Ruth; Lee, Dionne

    2012-01-01

    Purpose: The purpose of this paper is to explore the issues around a multiple generational workforce and more specifically, the challenges and benefits for education providers and employers. Design/methodology/approach: Reviewing research papers, analysing academic texts, interrogating market intelligence and contextualising case studies, the…

  13. Unidirectional, dual-comb lasing under multiple pulse formation mechanisms in a passively mode-locked fiber ring laser

    NASA Astrophysics Data System (ADS)

    Liu, Ya; Zhao, Xin; Hu, Guoqing; Li, Cui; Zhao, Bofeng; Zheng, Zheng

    2016-09-01

    Dual-comb lasers from which asynchronous ultrashort pulses can be simultaneously generated have recently become an interesting research subject. They could be an intriguing alternative to the current dual-laser optical-frequency-comb source with highly sophisticated electronic control systems. If generated through a common light path traveled by all pulses, the common-mode noises between the spectral lines of different pulse trains could be significantly reduced. Therefore, coherent dual-comb generation from a completely common-path, unidirectional lasing cavity would be an interesting territory to explore. In this paper, we demonstrate such a dual-comb lasing scheme based on a nanomaterial saturable absorber with additional pulse narrowing and broadening mechanisms concurrently introduced into a mode-locked fiber laser. The interactions between multiple soliton formation mechanisms result in unusual bifurcation into two-pulse states with quite different characteristics. Simultaneous oscillation of pulses with four-fold difference in pulsewidths and tens of Hz repetition rate difference is observed. The coherence between these spectral-overlapped, picosecond and femtosecond pulses is further verified by the corresponding asynchronous cross-sampling and dual-comb spectroscopy measurements.

  14. Laser pulse induced multiple exciton kinetics in molecular ring structures

    NASA Astrophysics Data System (ADS)

    Hou, Xiao; Wang, Luxia

    2016-11-01

    Multiple excitons can be formed upon strong optical excitation of molecular aggregates and complexes. Based on a theoretical approach on exciton-exciton annihilation dynamics in supramolecular systems (May et al., 2014), exciton interaction kinetics in ring aggregates of two-level molecules are investigated. Excited by the sub-picosecond laser pulse, multiple excitons keep stable in the molecular ring shaped as a regular polygon. If the symmetry is destroyed by changing the dipole of a single molecule, the excitation of different molecules becomes not identical, and the changed dipole-dipole interaction initiates subsequent energy redistribution. Depending on the molecular distance and the dipole configuration, the kinetics undergo different types of processes, but all get stable within some hundreds of femtoseconds. The study of exciton kinetics will be helpful for further investigations of the efficiency of optical devices based on molecular aggregates.

  15. Oscillation-Driven Spike-Timing Dependent Plasticity Allows Multiple Overlapping Pattern Recognition in Inhibitory Interneuron Networks.

    PubMed

    Garrido, Jesús A; Luque, Niceto R; Tolu, Silvia; D'Angelo, Egidio

    2016-08-01

    The majority of operations carried out by the brain require learning complex signal patterns for future recognition, retrieval and reuse. Although learning is thought to depend on multiple forms of long-term synaptic plasticity, the way this latter contributes to pattern recognition is still poorly understood. Here, we have used a simple model of afferent excitatory neurons and interneurons with lateral inhibition, reproducing a network topology found in many brain areas from the cerebellum to cortical columns. When endowed with spike-timing dependent plasticity (STDP) at the excitatory input synapses and at the inhibitory interneuron-interneuron synapses, the interneurons rapidly learned complex input patterns. Interestingly, induction of plasticity required that the network be entrained into theta-frequency band oscillations, setting the internal phase-reference required to drive STDP. Inhibitory plasticity effectively distributed multiple patterns among available interneurons, thus allowing the simultaneous detection of multiple overlapping patterns. The addition of plasticity in intrinsic excitability made the system more robust allowing self-adjustment and rescaling in response to a broad range of input patterns. The combination of plasticity in lateral inhibitory connections and homeostatic mechanisms in the inhibitory interneurons optimized mutual information (MI) transfer. The storage of multiple complex patterns in plastic interneuron networks could be critical for the generation of sparse representations of information in excitatory neuron populations falling under their control. PMID:27079422

  16. Meta-analysis of genome-wide association studies reveals genetic overlap between Hodgkin lymphoma and multiple sclerosis

    PubMed Central

    Khankhanian, Pouya; Cozen, Wendy; Himmelstein, Daniel S; Madireddy, Lohith; Din, Lennox; van den Berg, Anke; Matsushita, Takuya; Glaser, Sally L; Moré, Jayaji M; Smedby, Karin E.; Baranzini, Sergio E; Mack, Thomas M; Lizée, Antoine; de Sanjosé, Silvia; Gourraud, Pierre-Antoine; Nieters, Alexandra; Hauser, Stephen L; Cocco, Pierluigi; Maynadié, Marc; Foretová, Lenka; Staines, Anthony; Delahaye-Sourdeix, Manon; Li, Dalin; Bhatia, Smita; Melbye, Mads; Onel, Kenan; Jarrett, Ruth; McKay, James D; Oksenberg, Jorge R; Hjalgrim, Henrik

    2016-01-01

    Background: Based on epidemiological commonalities, multiple sclerosis (MS) and Hodgkin lymphoma (HL), two clinically distinct conditions, have long been suspected to be aetiologically related. MS and HL occur in roughly the same age groups, both are associated with Epstein-Barr virus infection and ultraviolet (UV) light exposure, and they cluster mutually in families (though not in individuals). We speculated if in addition to sharing environmental risk factors, MS and HL were also genetically related. Using data from genome-wide association studies (GWAS) of 1816 HL patients, 9772 MS patients and 25 255 controls, we therefore investigated the genetic overlap between the two diseases. Methods: From among a common denominator of 404 K single nucleotide polymorphisms (SNPs) studied, we identified SNPs and human leukocyte antigen (HLA) alleles independently associated with both diseases. Next, we assessed the cumulative genome-wide effect of MS-associated SNPs on HL and of HL-associated SNPs on MS. To provide an interpretational frame of reference, we used data from published GWAS to create a genetic network of diseases within which we analysed proximity of HL and MS to autoimmune diseases and haematological and non-haematological malignancies. Results: SNP analyses revealed genome-wide overlap between HL and MS, most prominently in the HLA region. Polygenic HL risk scores explained 4.44% of HL risk (Nagelkerke R2), but also 2.36% of MS risk. Conversely, polygenic MS risk scores explained 8.08% of MS risk and 1.94% of HL risk. In the genetic disease network, HL was closer to autoimmune diseases than to solid cancers. Conclusions: HL displays considerable genetic overlap with MS and other autoimmune diseases. PMID:26971321

  17. Reconstructing surface wave profiles from reflected acoustic pulses using multiple receivers.

    PubMed

    Walstead, Sean P; Deane, Grant B

    2014-08-01

    Surface wave shapes are determined by analyzing underwater reflected acoustic signals collected at multiple receivers. The transmitted signals are of nominal frequency 300 kHz and are reflected off surface gravity waves that are paddle-generated in a wave tank. An inverse processing algorithm reconstructs 50 surface wave shapes over a length span of 2.10 m. The inverse scheme uses a broadband forward scattering model based on Kirchhoff's diffraction formula to determine wave shapes. The surface reconstruction algorithm is self-starting in that source and receiver geometry and initial estimates of wave shape are determined from the same acoustic signals used in the inverse processing. A high speed camera provides ground-truth measurements of the surface wave field for comparison with the acoustically derived surface waves. Within Fresnel zone regions the statistical confidence of the inversely optimized surface profile exceeds that of the camera profile. Reconstructed surfaces are accurate to a resolution of about a quarter-wavelength of the acoustic pulse only within Fresnel zones associated with each source and receiver pair. Multiple isolated Fresnel zones from multiple receivers extend the spatial extent of accurate surface reconstruction while overlapping Fresnel zones increase confidence in the optimized profiles there. PMID:25096095

  18. Dubowitz syndrome is a complex comprised of multiple, genetically distinct and phenotypically overlapping disorders.

    PubMed

    Stewart, Douglas R; Pemov, Alexander; Johnston, Jennifer J; Sapp, Julie C; Yeager, Meredith; He, Ji; Boland, Joseph F; Burdett, Laurie; Brown, Christina; Gatti, Richard A; Alter, Blanche P; Biesecker, Leslie G; Savage, Sharon A

    2014-01-01

    Dubowitz syndrome is a rare disorder characterized by multiple congenital anomalies, cognitive delay, growth failure, an immune defect, and an increased risk of blood dyscrasia and malignancy. There is considerable phenotypic variability, suggesting genetic heterogeneity. We clinically characterized and performed exome sequencing and high-density array SNP genotyping on three individuals with Dubowitz syndrome, including a pair of previously-described siblings (Patients 1 and 2, brother and sister) and an unpublished patient (Patient 3). Given the siblings' history of bone marrow abnormalities, we also evaluated telomere length and performed radiosensitivity assays. In the siblings, exome sequencing identified compound heterozygosity for a known rare nonsense substitution in the nuclear ligase gene LIG4 (rs104894419, NM_002312.3:c.2440C>T) that predicts p.Arg814X (MAF:0.0002) and an NM_002312.3:c.613delT variant that predicts a p.Ser205Leufs*29 frameshift. The frameshift mutation has not been reported in 1000 Genomes, ESP, or ClinSeq. These LIG4 mutations were previously reported in the sibling sister; her brother had not been previously tested. Western blotting showed an absence of a ligase IV band in both siblings. In the third patient, array SNP genotyping revealed a de novo ∼ 3.89 Mb interstitial deletion at chromosome 17q24.2 (chr 17:62,068,463-65,963,102, hg18), which spanned the known Carney complex gene PRKAR1A. In all three patients, a median lymphocyte telomere length of ≤ 1st centile was observed and radiosensitivity assays showed increased sensitivity to ionizing radiation. Our work suggests that, in addition to dyskeratosis congenita, LIG4 and 17q24.2 syndromes also feature shortened telomeres; to confirm this, telomere length testing should be considered in both disorders. Taken together, our work and other reports on Dubowitz syndrome, as currently recognized, suggest that it is not a unitary entity but instead a collection of phenotypically

  19. Dubowitz Syndrome Is a Complex Comprised of Multiple, Genetically Distinct and Phenotypically Overlapping Disorders

    PubMed Central

    Stewart, Douglas R.; Pemov, Alexander; Johnston, Jennifer J.; Sapp, Julie C.; Yeager, Meredith; He, Ji; Boland, Joseph F.; Burdett, Laurie; Brown, Christina; Gatti, Richard A.; Alter, Blanche P.; Biesecker, Leslie G.; Savage, Sharon A.

    2014-01-01

    Dubowitz syndrome is a rare disorder characterized by multiple congenital anomalies, cognitive delay, growth failure, an immune defect, and an increased risk of blood dyscrasia and malignancy. There is considerable phenotypic variability, suggesting genetic heterogeneity. We clinically characterized and performed exome sequencing and high-density array SNP genotyping on three individuals with Dubowitz syndrome, including a pair of previously-described siblings (Patients 1 and 2, brother and sister) and an unpublished patient (Patient 3). Given the siblings' history of bone marrow abnormalities, we also evaluated telomere length and performed radiosensitivity assays. In the siblings, exome sequencing identified compound heterozygosity for a known rare nonsense substitution in the nuclear ligase gene LIG4 (rs104894419, NM_002312.3:c.2440C>T) that predicts p.Arg814X (MAF:0.0002) and an NM_002312.3:c.613delT variant that predicts a p.Ser205Leufs*29 frameshift. The frameshift mutation has not been reported in 1000 Genomes, ESP, or ClinSeq. These LIG4 mutations were previously reported in the sibling sister; her brother had not been previously tested. Western blotting showed an absence of a ligase IV band in both siblings. In the third patient, array SNP genotyping revealed a de novo ∼3.89 Mb interstitial deletion at chromosome 17q24.2 (chr 17:62,068,463–65,963,102, hg18), which spanned the known Carney complex gene PRKAR1A. In all three patients, a median lymphocyte telomere length of ≤1st centile was observed and radiosensitivity assays showed increased sensitivity to ionizing radiation. Our work suggests that, in addition to dyskeratosis congenita, LIG4 and 17q24.2 syndromes also feature shortened telomeres; to confirm this, telomere length testing should be considered in both disorders. Taken together, our work and other reports on Dubowitz syndrome, as currently recognized, suggest that it is not a unitary entity but instead a collection of phenotypically

  20. Measurement of spatial gain profiles in multiple pulse driven Ne like Ge lasers

    SciTech Connect

    Nilsen, J.; Moreno, J.C.; Barbee, T.W.; Da Silva, L.B.

    1997-06-01

    We present the first direct spatial measurement of the two dimensional gain profiles for a Ne-like ion using a slab target illuminated by the multiple pulse technique. To understand the spatial dependence of the gain in Ne-like Ge on the 19.6 nm laser line for plasmas driven by a series of 100 ps pulses 400 ps apart we did a series of Nova experiments backlighting short Ge amplifiers. Two-dimensional, high-resolution, spatial images of the 19.6 nm laser emission from the output aperture of the amplifiers were measured to determine the spatial position of the gain. The amplifier lengths were chosen to be short enough to avoid significant refraction of the beam. In previous imaging experiments which measured the near field output of the Ge laser, the position of the laser output was dominated by refraction effects. To assure good temporal overlap, we used the traveling wave geometry to illuminate both the amplifier and backlighter. The amplifier design included a wire fiducial which provided an absolute spatial reference and avoided the usual difficulty of determining the location of the target surface. We compare the measured gain with simulations done using LASNEX, which calculates the hydrodynamic evolution of the plasma, and XRASER, which uses the temperature and densities from LASNEX to do the gain and kinetics calculations.

  1. Characterizations of double pulsing in neutron multiplicity and coincidence counting systems

    NASA Astrophysics Data System (ADS)

    Koehler, Katrina E.; Henzl, Vladimir; Croft, Stephen S.; Henzlova, Daniela; Santi, Peter A.

    2016-10-01

    Passive neutron coincidence/multiplicity counters are subject to non-ideal behavior, such as double pulsing and dead time. It has been shown in the past that double-pulsing exhibits a distinct signature in a Rossi-alpha distribution, which is not readily noticed using traditional Multiplicity Shift Register analysis. However, it has been assumed that the use of a pre-delay in shift register analysis removes any effects of double pulsing. In this work, we use high-fidelity simulations accompanied by experimental measurements to study the effects of double pulsing on multiplicity rates. By exploiting the information from the double pulsing signature peak observable in the Rossi-alpha distribution, the double pulsing fraction can be determined. Algebraic correction factors for the multiplicity rates in terms of the double pulsing fraction have been developed. We discuss the role of these corrections across a range of scenarios.

  2. The auditory and non-auditory brain areas involved in tinnitus. An emergent property of multiple parallel overlapping subnetworks.

    PubMed

    Vanneste, Sven; De Ridder, Dirk

    2012-01-01

    Tinnitus is the perception of a sound in the absence of an external sound source. It is characterized by sensory components such as the perceived loudness, the lateralization, the tinnitus type (pure tone, noise-like) and associated emotional components, such as distress and mood changes. Source localization of quantitative electroencephalography (qEEG) data demonstrate the involvement of auditory brain areas as well as several non-auditory brain areas such as the anterior cingulate cortex (dorsal and subgenual), auditory cortex (primary and secondary), dorsal lateral prefrontal cortex, insula, supplementary motor area, orbitofrontal cortex (including the inferior frontal gyrus), parahippocampus, posterior cingulate cortex and the precuneus, in different aspects of tinnitus. Explaining these non-auditory brain areas as constituents of separable subnetworks, each reflecting a specific aspect of the tinnitus percept increases the explanatory power of the non-auditory brain areas involvement in tinnitus. Thus, the unified percept of tinnitus can be considered an emergent property of multiple parallel dynamically changing and partially overlapping subnetworks, each with a specific spontaneous oscillatory pattern and functional connectivity signature. PMID:22586375

  3. CLAVATA1 dominant-negative alleles reveal functional overlap between multiple receptor kinases that regulate meristem and organ development.

    PubMed

    Diévart, Anne; Dalal, Monica; Tax, Frans E; Lacey, Alexzandria D; Huttly, Alison; Li, Jianming; Clark, Steven E

    2003-05-01

    The CLAVATA1 (CLV1) receptor kinase controls stem cell number and differentiation at the Arabidopsis shoot and flower meristems. Other components of the CLV1 signaling pathway include the secreted putative ligand CLV3 and the receptor-like protein CLV2. We report evidence indicating that all intermediate and strong clv1 alleles are dominant negative and likely interfere with the activity of unknown receptor kinase(s) that have functional overlap with CLV1. clv1 dominant-negative alleles show major differences from dominant-negative alleles characterized to date in animal receptor kinase signaling systems, including the lack of a dominant-negative effect of kinase domain truncation and the ability of missense mutations in the extracellular domain to act in a dominant-negative manner. We analyzed chimeric receptor kinases by fusing CLV1 and BRASSINOSTEROID INSENSITIVE1 (BRI1) coding sequences and expressing these in clv1 null backgrounds. Constructs containing the CLV1 extracellular domain and the BRI1 kinase domain were strongly dominant negative in the regulation of meristem development. Furthermore, we show that CLV1 expressed within the pedicel can partially replace the function of the ERECTA receptor kinase. We propose the presence of multiple receptors that regulate meristem development in a functionally related manner whose interactions are driven by the extracellular domains and whose activation requires the kinase domain.

  4. CLAVATA1 Dominant-Negative Alleles Reveal Functional Overlap between Multiple Receptor Kinases That Regulate Meristem and Organ Development

    PubMed Central

    Diévart, Anne; Dalal, Monica; Tax, Frans E.; Lacey, Alexzandria D.; Huttly, Alison; Li, Jianming; Clark, Steven E.

    2003-01-01

    The CLAVATA1 (CLV1) receptor kinase controls stem cell number and differentiation at the Arabidopsis shoot and flower meristems. Other components of the CLV1 signaling pathway include the secreted putative ligand CLV3 and the receptor-like protein CLV2. We report evidence indicating that all intermediate and strong clv1 alleles are dominant negative and likely interfere with the activity of unknown receptor kinase(s) that have functional overlap with CLV1. clv1 dominant-negative alleles show major differences from dominant-negative alleles characterized to date in animal receptor kinase signaling systems, including the lack of a dominant-negative effect of kinase domain truncation and the ability of missense mutations in the extracellular domain to act in a dominant-negative manner. We analyzed chimeric receptor kinases by fusing CLV1 and BRASSINOSTEROID INSENSITIVE1 (BRI1) coding sequences and expressing these in clv1 null backgrounds. Constructs containing the CLV1 extracellular domain and the BRI1 kinase domain were strongly dominant negative in the regulation of meristem development. Furthermore, we show that CLV1 expressed within the pedicel can partially replace the function of the ERECTA receptor kinase. We propose the presence of multiple receptors that regulate meristem development in a functionally related manner whose interactions are driven by the extracellular domains and whose activation requires the kinase domain. PMID:12724544

  5. Multiple Access in Ultra-Wideband Communications Using Multiple Pulses and the Use of Least Squares Filters

    SciTech Connect

    Nekoogar, F

    2003-06-19

    Multiple access (MA) in UWB communication has recently been studied in the context of multiple transmitted-reference short duration chirp pulses in the presence of additive white Gaussian noise (AWGN). The transmitted-reference (TR) receiver was extended in previous studies using multiple orthogonal pulses. Improved performance was observed in simulations by sampling the receiver autocorrelation function (ACF) at both zero- and non-zero lags. Sampling of non-zero ACF lags of orthogonal pulses is a novel approach. Method of using least squares filtering techniques for further tolerance against noise and interference for the TR method is proposed.

  6. Syntenic block overlap multiplicities with a panel of reference genomes provide a signature of ancient polyploidization events

    PubMed Central

    2015-01-01

    Background Following whole genome duplication (WGD), there is a compact distribution of gene similarities within the genome reflecting duplicate pairs of all the genes in the genome. With time, the distribution broadens and loses volume due to variable decay of duplicate gene similarity and to the process of duplicate gene loss. If there are two WGD, the older one becomes so reduced and broad that it merges with the tail of the distributions resulting from more recent events, and it becomes difficult to distinguish them. The goal of this paper is to advance statistical methods of identifying, or at least counting, the WGD events in the lineage of a given genome. Methods For a set of 15 angiosperm genomes, we analyze all 15 × 14 = 210 ordered pairs of target genome versus reference genome, using SynMap to find syntenic blocks. We consider all sets of B ≥ 2 syntenic blocks in the target genome that overlap in the reference genome as evidence of WGD activity in the target, whether it be one event or several. We hypothesize that in fitting an exponential function to the tail of the empirical distribution f (B) of block multiplicities, the size of the exponent will reflect the amount of WGD in the history of the target genome. Results By amalgamating the results from all reference genomes, a range of values of SynMap parameters, and alternative cutoff points for the tail, we find a clear pattern whereby multiple-WGD core eudicots have the smallest (negative) exponents, followed by core eudicots with only the single "γ" triplication in their history, followed by a non-core eudicot with a single WGD, followed by the monocots, with a basal angiosperm, the WGD-free Amborella having the largest exponent. Conclusion The hypothesis that the exponent of the fit to the tail of the multiplicity distribution is a signature of the amount of WGD is verified, but there is also a clear complicating factor in the monocot clade, where a history of multiple WGD is not reflected in a

  7. Multiple-circuit pulse generator for high repetition rate rare gas halide lasers.

    PubMed

    Wang, C P

    1978-10-01

    A multiple-circuit high pulse repetition frequency (PRF) pulse generator for the pumping of rare gas halide lasers is reported. With this multiple-circuit design, high PRF can be achieved by the use of existing low PRF thyratron switches and capacitors. A two-circuit pulse generator was constructed, and its performance is described. By means of this pulse generator and a blowdown-type fast transverse-flow system, high PRF laser action in XeF was obtained, typically, 6 mJ/pulse at 1 kHz or 6 W average power. High PRF laser action in N(2) was also observed.

  8. High pulse repetition frequency, multiple wavelength, pulsed CO2 lidar system for atmospheric transmission and target reflectance measurements

    NASA Astrophysics Data System (ADS)

    Ben-David, Avishai; Emery, Silvio L.; Gotoff, Steven W.; D'Amico, Francis M.

    1992-07-01

    A multiple wavelength, pulsed CO2 lidar system operating at a pulse repetition frequency of 200 Hz and permitting the random selection of CO2 laser wavelengths for each laser pulse is presented. This system was employed to measure target reflectance and atmospheric transmission by using laser pulse bursts consisting of groups with as many as 16 different wavelengths at a repetition rate of 12 Hz. The wavelength tuning mechanism of the transversely excited atmospheric laser consists of a stationary grating and a flat mirror controlled by a galvanometer. Multiple wavelength, differential absorption lidar (DIAL) measurements reduce the effects of differential target reflectance and molecular absorption interference. Examples of multiwavelength DIAL detection for ammonia and water vapor show the dynamic interaction between these two trace gases. Target reflectance measurements for maple trees in winter and autumn are presented.

  9. High pulse repetition frequency, multiple wavelength, pulsed CO(2) lidar system for atmospheric transmission and target reflectance measurements.

    PubMed

    Ben-David, A; Emery, S L; Gotoff, S W; D'Amico, F M

    1992-07-20

    A multiple wavelength, pulsed CO(2) lidar system operating at a pulse repetition frequency of 200 Hz and permitting the random selection of CO(2) laser wavelengths for each laser pulse is presented. This system was employed to measure target reflectance and atmospheric transmission by using laser pulse bursts consisting of groups with as many as 16 different wavelengths at a repetition rate of 12 Hz. The wavelength tuning mechanism of the transversely excited atmospheric laser consists of a stationary grating and a flat mirror controlled by a galvanometer. Multiple wavelength, differential absorption lidar (DIAL) measurements reduce the effects of differential target reflectance and molecular absorption interference. Examples of multiwavelength DIAL detection for ammonia and water vapor show the dynamic interaction between these two trace gases. Target reflectance measurements for maple trees in winter and autumn are presented. PMID:20725406

  10. Multiple noise-like pulsing of a figure-eight fibre laser

    NASA Astrophysics Data System (ADS)

    Pottiez, O.; Ibarra-Escamilla, B.; Kuzin, E. A.; Hernández-García, J. C.; González-García, A.; Durán-Sánchez, M.

    2014-01-01

    In this work we study multiple noise-like pulse generation in a 320 m long passively mode-locked erbium-doped figure-eight fibre laser in the normal net dispersion regime. The nonlinear optical loop mirror (NOLM) that is used as a mode locker operates through polarization asymmetry, which allows us to control its switching power by birefringence adjustments at the NOLM input, using a half-wave retarder (HWR). Over some range of the HWR orientation, a single noise-like pulse is observed in the cavity. Its peak power is adjustable as it remains clamped to the variable switching power, and its duration varies inversely between ˜5 and ˜22 ps. Beyond the HWR position, corresponding to the longest duration, the pulse splits into several noise-like pulses. These multiple pulses usually present a walkoff, however they can be synchronized through slight birefringence adjustments, although they are not evenly spaced in time. Up to 12 simultaneous noise-like pulses were observed experimentally, with a duration of ˜2 ns. Multiple pulsing and synchronization of the pulses are interpreted in terms of mechanisms of interaction between pulses. Multiple pulsing appears to be indirectly related to the peak power limiting effect of the NOLM.

  11. Transient thermal blooming of single and multiple short laser pulses.

    PubMed

    Buser, R G; Rohde, R S; Berger, P J; Gebhardt, F G; Smith, D C

    1975-11-01

    Energy transfer through absorbing media with pulses short compared to the acoustic transit time has been investigated experimentally and theoretically for collimated beams in a homogeneous wind field. Two experimental approaches were used: a low intensity cw CO(2) laser probe beam technique giving a continuous record of the lensing of the medium following the transmission of a coaxial high power TEA laser pulse and a direct determination of high power pulse train blooming using a thermofax covered drum. The experimental results support the predictions of a geometric optics perturbation solution as well as those of existing propagation codes. An interesting case, namely, enhancement resulting in a 20-30% increase of the original nonbloomed peak intensity is observed when the pulse separation time is approximately 1-2 times the wind flow time across the beam.

  12. Examining Estimates of Effect Using Non-Overlap of All Pairs in Multiple Baseline Studies of Academic Intervention

    ERIC Educational Resources Information Center

    Petersen-Brown, Shawna; Karich, Abbey C.; Symons, Frank J.

    2012-01-01

    The inclusion of single-case design (SCD) studies in meta-analytic research is an important consideration in identifying effective evidence-based practices. Various SCD effect sizes have been previously suggested; non-overlap of all pairs (NAP) is a recently introduced effect size. Preliminary field tests investigating the adequacy of NAP are…

  13. Coherent femtosecond pulse combining of multiple parallel chirped pulse fiber amplifiers.

    PubMed

    Siiman, Leo A; Chang, Wei-zung; Zhou, Tong; Galvanauskas, Almantas

    2012-07-30

    We report on femtosecond pulse combining with up to four parallel chirped-pulse fiber amplifier channels. Active phase locking is implemented using the LOCSET (Locking of Optical Coherence by Single-detector Electronic-frequency Tagging) single detector feedback technique, resulting in 96.4%, 94.0%, and 93.9% relative combining efficiency with two, three, and four channels respectively. Theoretical and experimental analysis of combining efficiency dependence on amplitude and phase noise shows convergence to a fixed value with increasing number of channels, indicating that multi-channel pulse combining with LOCSET feedback should be scalable to very large numbers of channels.

  14. Design and operation of the multiple-pulse driver line on the OMEGA laser

    NASA Astrophysics Data System (ADS)

    Kosc, T. Z.; Kelly, J. H.; Hill, E. M.; Waxer, L. J.

    2016-05-01

    The multiple-pulse driver line (MPD) provides on-shot co-propagation of two separately generated pulse shapes in all 60 OMEGA beams at the Laboratory for Laser Energetics. Smoothing by spectral dispersion (SSD), which increases the laser bandwidth, can be applied to either one of the two pulse shapes, thereby enabling dynamic bandwidth reduction. The design of the MPD required careful consideration of beam combination as well as the minimum pulse separation for two pulses generated by two separate seed sources. A new combined-pulse-shape diagnostic needed to be designed and installed after the last SSD grating. The capability of MPD to reduce dynamic bandwidth has been used on a series of campaigns on OMEGA and the performance data are presented.

  15. Pulse Jet Mixer Overblow Testing for Assessment of Loadings During Multiple Overblows

    SciTech Connect

    Pfund, David M.; Bontha, Jagannadha R.; Michener, Thomas E.; Nigl, Franz; Yokuda, Satoru T.; Leigh, Richard J.; Golovich, Elizabeth C.; Baumann, Aaron W.; Kurath, Dean E.; Hoza, Mark; Combs, William H.; Fort, James A.; Bredt, Ofelia P.

    2008-03-03

    The U.S. Department of Energy (DOE) Office of River Protection’s Waste Treatment Plant (WTP) is being designed and built to pretreat and then vitrify a large portion of the wastes in Hanford’s 177 underground waste storage tanks. The WTP consists of three primary facilities: pretreatment, low-activity waste (LAW) vitrification, and high-level waste (HLW) vitrification. The pretreatment facility will receive waste feed from the Hanford tank farms and separate it into 1) a high-volume, low-activity liquid stream stripped of most solids and radionuclides and 2) a much smaller volume of HLW slurry containing most of the solids and most of the radioactivity. Many of the vessels in the pretreatment facility will contain pulse jet mixers (PJMs) that will provide some or all of the mixing in the vessels. This technology was selected for use in so-called “black cell” regions of the WTP, where maintenance capability will not be available for the operating life of the WTP. PJM technology was selected for use in these regions because it has no moving mechanical parts that require maintenance. The vessels with the most concentrated slurries will also be mixed with air spargers and/or steady jets in addition to the mixing provided by the PJMs. This report contains the results of single and multiple PJM overblow tests conducted in a large, ~13 ft-diameter × 15-ft-tall tank located in the high bay of the Pacific Northwest National Laboratory (PNNL) 336 Building test facility. These single and multiple PJM overblow tests were conducted using water and a clay simulant to bound the lower and upper rheological properties of the waste streams anticipated to be processed in the WTP. Hydrodynamic pressures were measured at a number of locations in the test vessel using an array of nine pressure sensors and four hydrophones. These measurements were made under normal and limiting vessel operating conditions (i.e., maximum PJM fluid emptying velocity, maximum and minimum vessel

  16. Pulse Jet Mixer Overblow Testing for Assessment of Loadings During Multiple Overblows

    SciTech Connect

    Pfund, David M.; Bontha, Jagannadha R.; Michener, Thomas E.; Nigl, Franz; Yokuda, Satoru T.; Leigh, Richard J.; Golovich, Elizabeth C.; Baumann, Aaron W.; Kurath, Dean E.; Hoza, Mark; Combs, William H.; Fort, James A.; Bredt, Ofelia P.

    2009-07-20

    The U.S. Department of Energy (DOE) Office of River Protection’s Waste Treatment Plant (WTP) is being designed and built to pretreat and then vitrify a large portion of the wastes in Hanford’s 177 underground waste storage tanks. The WTP consists of three primary facilities: pretreatment, low-activity waste (LAW) vitrification, and high-level waste (HLW) vitrification. The pretreatment facility will receive waste feed from the Hanford tank farms and separate it into 1) a high-volume, low-activity liquid stream stripped of most solids and radionuclides and 2) a much smaller volume of HLW slurry containing most of the solids and most of the radioactivity. Many of the vessels in the pretreatment facility will contain pulse jet mixers (PJMs) that will provide some or all of the mixing in the vessels. This technology was selected for use in so-called “black cell” regions of the WTP, where maintenance capability will not be available for the operating life of the WTP. PJM technology was selected for use in these regions because it has no moving mechanical parts that require maintenance. The vessels with the most concentrated slurries will also be mixed with air spargers and/or steady jets in addition to the mixing provided by the PJMs. This report contains the results of single and multiple PJM overblow tests conducted in a large, ~13 ft-diameter × 15-ft-tall tank located in the high bay of the Pacific Northwest National Laboratory (PNNL) 336 Building test facility. These single and multiple PJM overblow tests were conducted using water and a clay simulant to bound the lower and upper rheological properties of the waste streams anticipated to be processed in the WTP. Hydrodynamic pressures were measured at a number of locations in the test vessel using an array of nine pressure sensors and four hydrophones. These measurements were made under normal and limiting vessel operating conditions (i.e., maximum PJM fluid emptying velocity, maximum and minimum vessel

  17. Versatile patterns of multiple rectangular noise-like pulses in a fiber laser.

    PubMed

    Huang, Yu-Qi; Qi, You-Li; Luo, Zhi-Chao; Luo, Ai-Ping; Xu, Wen-Cheng

    2016-04-01

    We report on the generation of versatile patterns of multiple rectangular noise-like pulses (NLPs) in a fiber laser mode-locked by nonlinear amplifying loop mirror (NALM). Benefiting from the strengthened nonlinear effect of a segment of highly nonlinear fiber (HNLF) in the loop, multiple rectangular NLPs with various patterns are formed depending on the cavity parameter settings. In particular, the multiple rectangular NLPs could possess unequal packet durations, which is different from the conventional multi-soliton patterns. The experimental results contribute to further understanding the characteristics of the rectangular NLP and the dynamics of multi-pulse patterns. PMID:27137025

  18. Alignment of asymetric-top molecules using multiple-pulse trains.

    SciTech Connect

    Pabst, S.; Santra, R.; X-Ray Science Division; Univ. Erlangen-Nuremberg; Univ. of Chicago

    2010-06-07

    We theoretically analyze the effectiveness of multiple-pulse laser alignment methods for asymmetric-top molecules. As an example, we choose SO2 and investigate the alignment dynamics induced by two different sequences, each consisting of four identical laser pulses. Each sequence differs only in the time delay between the pulses. Equally spaced pulses matching the alignment revival of the symmetrized SO2 rotor model are exploited in the first sequence. The pulse separations in the second sequence are short compared to the rotation dynamics of the molecule and monotonically increase the degree of alignment until the maximum alignment is reached. We point out the significant differences between the alignment dynamics of SO2 treated as an asymmetric-top and a symmetric-top rotor, respectively. We also explain why the fast sequence of laser pulses creates considerably stronger one-dimensional molecular alignment for asymmetric-top molecules. In addition, we show that multiple-pulse trains with elliptically polarized pulses do not enhance one-dimensional alignment or create three-dimensional alignment.

  19. Alignment of asymmetric-top molecules using multiple-pulse trains

    SciTech Connect

    Pabst, Stefan; Santra, Robin

    2010-06-15

    We theoretically analyze the effectiveness of multiple-pulse laser alignment methods for asymmetric-top molecules. As an example, we choose SO{sub 2} and investigate the alignment dynamics induced by two different sequences, each consisting of four identical laser pulses. Each sequence differs only in the time delay between the pulses. Equally spaced pulses matching the alignment revival of the symmetrized SO{sub 2} rotor model are exploited in the first sequence. The pulse separations in the second sequence are short compared to the rotation dynamics of the molecule and monotonically increase the degree of alignment until the maximum alignment is reached. We point out the significant differences between the alignment dynamics of SO{sub 2} treated as an asymmetric-top and a symmetric-top rotor, respectively. We also explain why the fast sequence of laser pulses creates considerably stronger one-dimensional molecular alignment for asymmetric-top molecules. In addition, we show that multiple-pulse trains with elliptically polarized pulses do not enhance one-dimensional alignment or create three-dimensional alignment.

  20. Hydra viridissima (green Hydra) rapidly recovers from multiple magnesium pulse exposures.

    PubMed

    Prouse, Andrea E; Hogan, Alicia C; Harford, Andrew J; van Dam, Rick A; Nugegoda, Dayanthi

    2015-08-01

    The time taken for organisms to recover from a pulsed toxicant exposure is an important consideration when water quality guidelines are applied to intermittent events in the environment. Organisms may appear to have recovered by standard toxicity testing methods but could carry residual toxicant or damage that may make them more sensitive to subsequent pulses. Such cumulative effects may render guidelines underprotective. The present study evaluated recovery of the freshwater cnidarian Hydra viridissima following multiple pulse exposure to magnesium (Mg). The H. viridissima were exposed to 4-h pulses of 790 mg/L and 1100 mg/L separated by 2-h, 10-h, 18-h, 24-h, 48-h, and 72-h recovery periods. Twenty-four-hour pulses of 570 mg/L, 910 mg/L, and 940 mg/L were separated by 24-h, 96-h, and 168-h recovery periods. All treatments showed similar or reduced sensitivity to the second pulse when compared with the single pulse, indicating that full recovery occurred prior to a second pulse-exposure. Five variations of equivalent time-weighted average concentrations were used to compare sensitivity of Hydra with various pulse scenarios. The sensitivity of the organisms to the multiple pulses was significantly lower than the time-weighted average continuous exposure response in 3 of the 4 scenarios tested, indicating that the Hydra benefited from interpulse recovery periods. The findings will be utilized alongside those from other species to inform the use of a site-specific, duration-based water quality guideline for Mg, and they provide an example of the use of empirical data in the regulation of toxicant pulses in the environment.

  1. [Research on the Method of Blood Pressure Monitoring Based on Multiple Parameters of Pulse Wave].

    PubMed

    Miao, Changyun; Mu, Dianwei; Zhang, Cheng; Miao, Chunjiao; Li, Hongqiang

    2015-10-01

    In order to improve the accuracy of blood pressure measurement in wearable devices, this paper presents a method for detecting blood pressure based on multiple parameters of pulse wave. Based on regression analysis between blood pressure and the characteristic parameters of pulse wave, such as the pulse wave transit time (PWTT), cardiac output, coefficient of pulse wave, the average slope of the ascending branch, heart rate, etc. we established a model to calculate blood pressure. For overcoming the application deficiencies caused by measuring ECG in wearable device, such as replacing electrodes and ECG lead sets which are not convenient, we calculated the PWTT with heart sound as reference (PWTT(PCG)). We experimentally verified the detection of blood pressure based on PWTT(PCG) and based on multiple parameters of pulse wave. The experiment results showed that it was feasible to calculate the PWTT from PWTT(PCG). The mean measurement error of the systolic and diastolic blood pressure calculated by the model based on multiple parameters of pulse wave is 1.62 mm Hg and 1.12 mm Hg, increased by 57% and 53% compared to those of the model based on simple parameter. This method has more measurement accuracy. PMID:26964321

  2. Pulsed squeezed light: Simultaneous squeezing of multiple modes

    SciTech Connect

    Wasilewski, Wojciech; Lvovsky, A. I.; Banaszek, Konrad; Radzewicz, Czeslaw

    2006-06-15

    We analyze the spectral properties of squeezed light produced by means of pulsed, single-pass degenerate parametric down-conversion. The multimode output of this process can be decomposed into characteristic modes undergoing independent squeezing evolution akin to the Schmidt decomposition of the biphoton spectrum. The main features of this decomposition can be understood using a simple analytical model developed in the perturbative regime. In the strong pumping regime, for which the perturbative approach is not valid, we present a numerical analysis, specializing to the case of one-dimensional propagation in a beta-barium borate waveguide. Characterization of the squeezing modes provides us with an insight necessary for optimizing homodyne detection of squeezing. For a weak parametric process, efficient squeezing is found in a broad range of local oscillator modes, whereas the intense generation regime places much more stringent conditions on the local oscillator. We point out that without meeting these conditions, the detected squeezing can actually diminish with the increasing pumping strength, and we expose physical reasons behind this inefficiency.

  3. Multiple-cycle Simulation of a Pulse Detonation Engine Ejector

    NASA Technical Reports Server (NTRS)

    Yungster, S.; Perkins, H. D.

    2002-01-01

    This paper presents the results of a study involving single and multiple-cycle numerical simulations of various PDE-ejector configurations utilizing hydrogen-oxygen mixtures. The objective was to investigate the thrust, impulse and mass flow rate characteristics of these devices. The results indicate that ejector systems can utilize the energy stored in the strong shock wave exiting the detonation tube to augment the impulse obtained from the detonation tube alone. Impulse augmentation ratios of up to 1.9 were achieved. The axial location of the converging-diverging ejectors relative to the end of the detonation tube were shown to affect the performance of the system.

  4. Fiber-Optic Distribution Of Pulsed Power To Multiple Sensors

    NASA Technical Reports Server (NTRS)

    Kirkham, Harold

    1996-01-01

    Optoelectronic systems designed according to time-sharing scheme distribute optical power to multiple integrated-circuit-based sensors in fiber-optic networks. Networks combine flexibility of electronic sensing circuits with advantage of electrical isolation afforded by use of optical fibers instead of electrical conductors to transmit both signals and power. Fiber optics resist corrosion and immune to electromagnetic interference. Sensor networks of this type useful in variety of applications; for example, in monitoring strains in aircraft, buildings, and bridges, and in monitoring and controlling shapes of flexible structures.

  5. Single- and multiple-pulse noncoherent detection statistics associated with partially developed speckle.

    PubMed

    Osche, G R

    2000-08-20

    Single- and multiple-pulse detection statistics are presented for aperture-averaged direct detection optical receivers operating against partially developed speckle fields. A partially developed speckle field arises when the probability density function of the received intensity does not follow negative exponential statistics. The case of interest here is the target surface that exhibits diffuse as well as specular components in the scattered radiation. An approximate expression is derived for the integrated intensity at the aperture, which leads to single- and multiple-pulse discrete probability density functions for the case of a Poisson signal in Poisson noise with an additive coherent component. In the absence of noise, the single-pulse discrete density function is shown to reduce to a generalized negative binomial distribution. The radar concept of integration loss is discussed in the context of direct detection optical systems where it is shown that, given an appropriate set of system parameters, multiple-pulse processing can be more efficient than single-pulse processing over a finite range of the integration parameter n. PMID:18350006

  6. Multiple quasi-monoenergetic electron beams from laser-wakefield acceleration with spatially structured laser pulse

    SciTech Connect

    Ma, Y.; Li, M. H.; Li, Y. F.; Wang, J. G.; Tao, M. Z.; Han, Y. J.; Zhao, J. R.; Huang, K.; Yan, W. C.; Ma, J. L.; Li, Y. T.; Chen, L. M.; Li, D. Z.; Chen, Z. Y.; Sheng, Z. M.; Zhang, J.

    2015-08-15

    By adjusting the focus geometry of a spatially structured laser pulse, single, double, and treble quasi-monoenergetic electron beams were generated, respectively, in laser-wakefield acceleration. Single electron beam was produced as focusing the laser pulse to a single spot. While focusing the laser pulse to two spots that are approximately equal in energy and size and intense enough to form their own filaments, two electron beams were produced. Moreover, with a proper distance between those two focal spots, three electron beams emerged with a certain probability owing to the superposition of the diffractions of those two spots. The energy spectra of the multiple electron beams are quasi-monoenergetic, which are different from that of the large energy spread beams produced due to the longitudinal multiple-injection in the single bubble.

  7. Statistical study of single and multiple pulse laser-induced damage in glasses

    NASA Astrophysics Data System (ADS)

    Gallais, L.; Natoli, J. Y.; Amra, C.

    2002-12-01

    Single and multiple pulse laser damage studies are performed in Suprasil silica and BK-7 borosilicate glasses. Experiments are made in the bulk of materials at 1.064µm with nanosecond pulses, using an accurate and reliable measurement system. By means of a statistical study on laser damage probabilities, we demonstrate that the same nano-precursors could be involved in the multiple shot and single shot damage process. A damage mechanism with two stages is then proposed to explain the results. Firstly, a pre-damage process, corresponding to material changes at a microscopic level, leads the precursor to a state that can induce a one-pulse damage. And secondly a final damage occurs, with a mechanism identical to the single shot case. For each material, a law is found to predict the precursor life-time. We can then deduce the long term life of optical elements in high-power laser systems submitted to multipulse irradiation.

  8. Properties of defect-induced multiple pulse laser damage of transmission components.

    PubMed

    Ma, Bin; Zhang, Li; Lu, Menglei; Wang, Ke; Jiao, Hongfei; Zhang, Jinlong; Cheng, Xinbin; Yang, Liming; Wang, Zhanshan

    2016-09-01

    When the number of laser pulses increases, the laser-induced damage threshold of the optical components gradually declines. The magnitude and tendency of this reduced threshold are associated with various factors. Furthermore, this reduced threshold is conclusively determined by the limiting factors or defect characteristics that trigger damage to optical components. Then, fully understanding the damage properties of different kinds of defects will contribute to the optimization of the performance and lifetime of the optical components. In this study, the statistical and deterministic characterizations of the fatigue effect are used to evaluate the properties of the multiple pulse laser damage of transmission components. First, the influence of spot sizes and polishing materials on the properties of the multiple pulse laser damage of optical components is discussed. Then, the structural, absorptive, and mixed artificial defects are fabricated, and the damage characteristics are evaluated and analyzed. Finally, the damage mechanism of different factors has been clarified. PMID:27607284

  9. 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.

  10. 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.

  11. The FePt L10 phase transformation in thin films using multiple laser pulsing

    NASA Astrophysics Data System (ADS)

    Inaba, Yuki; Thompson, Gregory B.; Harrell, J. W.; Klemmer, Tim; Kubota, Yukiko

    2010-03-01

    A series of ≈12 nm thick FePt thin films deposited onto glass substrates have been annealed with multiple 1064 nm wavelength laser pulses. The fluence was varied using pulse widths of 10.0, 5.0, and 2.5 ms. The peak temperature for each individual pulse was kept near 700 °C. The A1 to L10 phase transformation was confirmed by x-ray diffraction. A single pulse was not sufficient to obtain a fully ordered state. A maximum order parameter of 0.89 and coercivity of 10.6 kOe was obtained after 5×10 ms pulses. This particular annealed film showed the greatest amount of grain growth with a mean size of 55.1 nm. This grain size is 20% smaller than that of a furnace annealed sample which was annealed for 60 s and yielded an approximately equivalent order parameter. Similar order parameters, grain sizes, and coercivity values were observed for films that had equivalent total annealing times regardless of pulse widths.

  12. Experimental study on double-pulse laser ablation of steel upon multiple parallel-polarized ultrashort-pulse irradiations

    NASA Astrophysics Data System (ADS)

    Schille, Joerg; Schneider, Lutz; Kraft, Sebastian; Hartwig, Lars; Loeschner, Udo

    2016-07-01

    In this paper, double-pulse laser processing is experimentally studied with the aim to explore the influence of ultrashort pulses with very short time intervals on ablation efficiency and quality. For this, sequences of 50 double pulses of varied energy and inter-pulse delay, as adjusted between 400 fs and 18 ns by splitting the laser beam into two optical paths of different length, were irradiated to technical-grade stainless steel. The depth and the volume of the craters produced were measured in order to evaluate the efficiency of the ablation process; the crater quality was analyzed by SEM micrographs. The results obtained were compared with craters produced with sequences of 50 single pulses and energies equal to the double pulse. It is demonstrated that double-pulse processing cannot exceed the ablation efficiency of single pulses of optimal fluence, but the ablation crater surface formed smoother if inter-pulse delay was in the range between 10 ns and 18 ns. In addition, the influence of pulse duration and energy distribution between the individual pulses of the double pulse on ablation was studied. For very short inter-pulse delay, no significant effect of energy variation within the double pulse on removal rate was found, indicating that the double pulse acts as a big single pulse of equal energy. Further, the higher removal efficiency was achieved when double-pulse processing using femtosecond pulses instead of picosecond pulses.

  13. Illusion induced overlapped optics.

    PubMed

    Zang, XiaoFei; Shi, Cheng; Li, Zhou; Chen, Lin; Cai, Bin; Zhu, YiMing; Zhu, HaiBin

    2014-01-13

    The traditional transformation-based cloak seems like it can only hide objects by bending the incident electromagnetic waves around the hidden region. In this paper, we prove that invisible cloaks can be applied to realize the overlapped optics. No matter how many in-phase point sources are located in the hidden region, all of them can overlap each other (this can be considered as illusion effect), leading to the perfect optical interference effect. In addition, a singular parameter-independent cloak is also designed to obtain quasi-overlapped optics. Even more amazing of overlapped optics is that if N identical separated in-phase point sources covered with the illusion media, the total power outside the transformation region is N2I0 (not NI0) (I0 is the power of just one point source, and N is the number point sources), which seems violating the law of conservation of energy. A theoretical model based on interference effect is proposed to interpret the total power of these two kinds of overlapped optics effects. Our investigation may have wide applications in high power coherent laser beams, and multiple laser diodes, and so on.

  14. Illusion induced overlapped optics.

    PubMed

    Zang, XiaoFei; Shi, Cheng; Li, Zhou; Chen, Lin; Cai, Bin; Zhu, YiMing; Zhu, HaiBin

    2014-01-13

    The traditional transformation-based cloak seems like it can only hide objects by bending the incident electromagnetic waves around the hidden region. In this paper, we prove that invisible cloaks can be applied to realize the overlapped optics. No matter how many in-phase point sources are located in the hidden region, all of them can overlap each other (this can be considered as illusion effect), leading to the perfect optical interference effect. In addition, a singular parameter-independent cloak is also designed to obtain quasi-overlapped optics. Even more amazing of overlapped optics is that if N identical separated in-phase point sources covered with the illusion media, the total power outside the transformation region is N2I0 (not NI0) (I0 is the power of just one point source, and N is the number point sources), which seems violating the law of conservation of energy. A theoretical model based on interference effect is proposed to interpret the total power of these two kinds of overlapped optics effects. Our investigation may have wide applications in high power coherent laser beams, and multiple laser diodes, and so on. PMID:24515019

  15. Rotational resonance with multiple-pulse scaling in solid-state nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Spencer, Richard G. S.; Fishbein, Kenneth W.; Levitt, Malcolm H.; Griffin, Robert G.

    1994-04-01

    Multiple-pulse techniques are applied to rotational resonance experiments in solid-state nuclear magnetic resonance. The usual rotational resonance condition is satisfied when an integral multiple of the magic-angle spinning speed equals the difference in isotropic chemical shifts of the two members of a homonuclear spin-1/2 pair. We show that sequences of rapid periodic radio-frequency pulses scale and rotate both the Zeeman and dipole-dipole Hamiltonians, leading to a modification of the resonance condition and to the introduction of new, single- and double-quantum, rotational resonances. Experimental results are presented which demonstrate these effects in the spectra of doubly 13C-labeled solids.

  16. Low temperature probe for dynamic nuclear polarization and multiple-pulse solid-state NMR.

    PubMed

    Cho, HyungJoon; Baugh, Jonathan; Ryan, Colm A; Cory, David G; Ramanathan, Chandrasekhar

    2007-08-01

    Here, we describe the design and performance characteristics of a low temperature probe for dynamic nuclear polarization (DNP) experiments, which is compatible with demanding multiple-pulse experiments. The competing goals of a high-Q microwave cavity to achieve large DNP enhancements and a high efficiency NMR circuit for multiple-pulse control lead to inevitable engineering tradeoffs. We have designed two probes-one with a single-resonance RF circuit and a horn-mirror cavity configuration for the microwaves and a second with a double-resonance RF circuit and a double-horn cavity configuration. The advantage of the design is that the sample is in vacuum, the RF circuits are locally tuned, and the microwave resonator has a large internal volume that is compatible with the use of RF and gradient coils.

  17. Role of multiple shots of femtosecond laser pulses in periodic surface nanoablation

    SciTech Connect

    Miyaji, Godai; Miyazaki, Kenzo

    2013-08-12

    Using a pump and probe technique, we observed time-dependent change in reflectivity of crystalline silicon surface to study the dynamic process of periodic surface nanostructure formation in femtosecond (fs) laser ablation. The results have shown that multiple shots of low-fluence fs laser pulses play the crucial role in the non-thermal process for nanostructuring through the increasing bonding structure change to amorphous silicon and resulting decrease in the ablation threshold.

  18. Synchronous precessional motion of multiple domain walls in a ferromagnetic nanowire by perpendicular field pulses

    PubMed Central

    Kim, June-Seo; Mawass, Mohamad-Assaad; Bisig, André; Krüger, Benjamin; Reeve, Robert M.; Schulz, Tomek; Büttner, Felix; Yoon, Jungbum; You, Chun-Yeol; Weigand, Markus; Stoll, Hermann; Schütz, Gisela; Swagten, Henk J. M.; Koopmans, Bert; Eisebitt, Stefan; Kläui, Mathias

    2014-01-01

    Magnetic storage and logic devices based on magnetic domain wall motion rely on the precise and synchronous displacement of multiple domain walls. The conventional approach using magnetic fields does not allow for the synchronous motion of multiple domains. As an alternative method, synchronous current-induced domain wall motion was studied, but the required high-current densities prevent widespread use in devices. Here we demonstrate a radically different approach: we use out-of-plane magnetic field pulses to move in-plane domains, thus combining field-induced magnetization dynamics with the ability to move neighbouring domain walls in the same direction. Micromagnetic simulations suggest that synchronous permanent displacement of multiple magnetic walls can be achieved by using transverse domain walls with identical chirality combined with regular pinning sites and an asymmetric pulse. By performing scanning transmission X-ray microscopy, we are able to experimentally demonstrate in-plane magnetized domain wall motion due to out-of-plane magnetic field pulses. PMID:24663150

  19. Stable radiation pressure acceleration of ions by suppressing transverse Rayleigh-Taylor instability with multiple Gaussian pulses

    NASA Astrophysics Data System (ADS)

    Zhou, M. L.; Liu, B.; Hu, R. H.; Shou, Y. R.; Lin, C.; Lu, H. Y.; Lu, Y. R.; Gu, Y. Q.; Ma, W. J.; Yan, X. Q.

    2016-08-01

    In the case of a thin plasma slab accelerated by the radiation pressure of an ultra-intense laser pulse, the development of Rayleigh-Taylor instability (RTI) will destroy the acceleration structure and terminate the acceleration process much sooner than theoretical limit. In this paper, a new scheme using multiple Gaussian pulses for ion acceleration in a radiation pressure acceleration regime is investigated with particle-in-cell simulation. We found that with multiple Gaussian pulses, the instability could be efficiently suppressed and the divergence of the ion bunch is greatly reduced, resulting in a longer acceleration time and much more collimated ion bunch with higher energy than using a single Gaussian pulse. An analytical model is developed to describe the suppression of RTI at the laser-plasma interface. The model shows that the suppression of RTI is due to the introduction of the long wavelength mode RTI by the multiple Gaussian pulses.

  20. Multiple pulse thermal damage thresholds of materials for x-ray free electron laser optics investigated with an ultraviolet laser

    SciTech Connect

    Hau-Riege, Stefan P.; London, Richard A.; Bionta, Richard M.; Soufli, Regina; Ryutov, Dmitri; Shirk, Michael; Baker, Sherry L.; Smith, Patrick M.; Nataraj, Pradeep

    2008-11-17

    Optical elements to be used for x-ray free electron lasers (XFELs) must withstand multiple high-fluence pulses. We have used an ultraviolet laser to study the damage of two candidate materials, crystalline Si and B{sub 4}C-coated Si, emulating the temperature profile expected to occur in optics exposed to XFEL pulses. We found that the damage threshold for 10{sup 5} pulses is {approx}20% to 70% lower than the melting threshold.

  1. High Dynamic Velocity Range Particle Image Velocimetry Using Multiple Pulse Separation Imaging

    PubMed Central

    Persoons, Tim; O’Donovan, Tadhg S.

    2011-01-01

    The dynamic velocity range of particle image velocimetry (PIV) is determined by the maximum and minimum resolvable particle displacement. Various techniques have extended the dynamic range, however flows with a wide velocity range (e.g., impinging jets) still challenge PIV algorithms. A new technique is presented to increase the dynamic velocity range by over an order of magnitude. The multiple pulse separation (MPS) technique (i) records series of double-frame exposures with different pulse separations, (ii) processes the fields using conventional multi-grid algorithms, and (iii) yields a composite velocity field with a locally optimized pulse separation. A robust criterion determines the local optimum pulse separation, accounting for correlation strength and measurement uncertainty. Validation experiments are performed in an impinging jet flow, using laser-Doppler velocimetry as reference measurement. The precision of mean flow and turbulence quantities is significantly improved compared to conventional PIV, due to the increase in dynamic range. In a wide range of applications, MPS PIV is a robust approach to increase the dynamic velocity range without restricting the vector evaluation methods. PMID:22346564

  2. Bone growth in zebrafish fins occurs via multiple pulses of cell proliferation.

    PubMed

    Jain, Isha; Stroka, Christine; Yan, Jianying; Huang, Wei-Min; Iovine, M Kathryn

    2007-09-01

    Fin length in the zebrafish is achieved by the distal addition of bony segments of the correct length. Genetic and molecular data provided evidence that segment growth uses a single pulse of growth, followed by a period of stasis. Examination of cell proliferation during segment growth was predicted to expose a graphical model consistent with a single burst of cell division (e.g., constant, parabolic, or exponential decay) during the lengthening of the distal-most segment. Cell proliferation was detected either by labeling animals with bromodeoxyuridine (during S-phase) or monitoring histone3-phosphate (mitosis). Results from both methods revealed that the number of proliferating cells fluctuates in apparent pulses as a segment grows (i.e., during the growth phase). Thus, rather than segment size being the result of a single burst of proliferation, it appears that segment growth is the result of several pulses of cell division that occur approximately every 60 microns (average segment length approximately 250 microns). These results indicate that segment lengthening requires multiple pulses of cell proliferation. PMID:17676636

  3. Magnetically-Driven Bremsstralung Targets for Multiple-Pulse X-Ray Radiography

    NASA Astrophysics Data System (ADS)

    Kwan, T. J. T.; Cochran, F. L.; Snell, C. M.; Benage, J. F.; Wolkerstorfer, D. C.

    2001-10-01

    In high-dose multiple-pulse x-ray radiography, the energy density deposited by an electron beam pulse in the target is high enough to cause vaporization of the target material and thus the creation of a plasma channel. The outward expansion of the target plasma causes the line density of the target material to drop rapidly. As a result, the efficiency of bremsstrahlung production by subsequent electron pulses can decrease significantly due to the lack of converter material along the electron beam path. We propose a novel converter target concept which makes use of a magnetically-driven, radially imploding liner to either dynamically replenish the converter material in the plasma channel or to move new target material into the line of sight of the electron beam. Pulsed-power technology is natural for this application because its dynamic time scale (microseconds) is well matched with radiographic parameters. Hydrodynamic simulations of the liner-target implosion and the associated x-ray dose calculations will be presented.

  4. Multiple Employment Training Programs. Overlapping Programs Can Add Unnecessary Administrative Costs. Report to the Ranking Minority Member, Committee on Appropriations, U.S. Senate.

    ERIC Educational Resources Information Center

    General Accounting Office, Washington, DC. Health, Education, and Human Services Div.

    A study explored the extent to which 154 federal programs that provide employment training assistance overlap in the populations targeted and services provided and whether such overlap has any potentially adverse effects. The research was conducted in the following ways: categorizing the 154 programs by the primary target populations served;…

  5. Magnetic resonance imaging of multiple sclerosis: a study of pulse-technique efficacy

    SciTech Connect

    Runge, V.M.; Price, A.C.; Kirshner, H.S.; Allen, J.H.; Partain, C.L.; James, A.E. Jr.

    1984-11-01

    Forty-two patients with the clinical diagnosis of multiple sclerosis were examined by proton magnetic resonance imaging (MRI) at 0.5 T. An extensive protocol was used to facilitate a comparison of the efficacy of different pulse techniques. Results were also compared in 39 cases with high-resolution x-ray computed tomography (CT). MRI revealed characteristic abnormalities in each case, whereas CT was positive in only 15 of 33 patients. Cerebral abnormalities were best shown with the T2-weighted spin-echo sequence: brainstem lesions were best defined on the inversion-recovery sequence.

  6. Few-Photon Multiple Ionization of Ne and Ar by Strong Free-Electron-Laser Pulses

    SciTech Connect

    Moshammer, R.; Jiang, Y. H.; Rudenko, A.; Ergler, Th.; Schroeter, C. D.; Luedemann, S.; Zrost, K.; Dorn, A.; Ferger, T.; Kuehnel, K. U.; Ullrich, J.; Foucar, L.; Titze, J.; Jahnke, T.; Schoeffler, M.; Doerner, R.; Fischer, D.; Weber, T.; Zouros, T. J. M.; Duesterer, S.

    2007-05-18

    Few-photon multiple ionization of Ne and Ar atoms by strong vacuum ultraviolet laser pulses from the free-electron laser at Hamburg was investigated differentially with the Heidelberg reaction microscope. The light-intensity dependence of Ne{sup 2+} production reveals the dominance of nonsequential two-photon double ionization at intensities of I<6x10{sup 12} W/cm{sup 2} and significant contributions of three-photon ionization as I increases. Ne{sup 2+} recoil-ion-momentum distributions suggest that two electrons absorbing ''instantaneously'' two photons are ejected most likely into opposite hemispheres with similar energies.

  7. Multiple folded resonator for LD pulse end pumped Q-switched Yb:YAG slab laser.

    PubMed

    Jun, Liu; Jianguo, Xin; Ye, Lang; Jiabin, Chen

    2014-09-01

    In this paper, a multiple folded resonator is presented which consists of a multiple optical folding setup, a flat total reflector, a flat output coupler, a Q-switch crystal and a polarizer. By this technique, the output energy of 32.6mJ and pulse width of 13.4ns with a repetition rate of 5Hz was obtained, which is three times higher than that reported in the past publications by the use of the currently existing technique of the Q-switched slab gain lasers with the unstable resonator. The output beam with a quality of M² = 1.55 in the slow axis and M² = 1.40 in the fast axis was also obtained. PMID:25321590

  8. Boosting the electron spin coherence in binuclear Mn complexes by multiple microwave pulses

    NASA Astrophysics Data System (ADS)

    Zaripov, R.; Vavilova, E.; Miluykov, V.; Bezkishko, I.; Sinyashin, O.; Salikhov, K.; Kataev, V.; Büchner, B.

    2013-09-01

    We investigate a possibility to enhance the coherence time of electron spins in magnetic molecular complexes by application of the Carr-Purcell-Meiboom-Gill (CPMG) multiple microwave pulse sequence. Our theoretical analysis shows that the CPMG sequence can efficiently suppress the spin decoherence channel arising due to spectral diffusion induced by a random modulation of the hyperfine interaction which is an important source of the spin dephasing in molecular magnets. We confirm this by employing the CPMG protocol in pulse electron spin resonance experiments on model binuclear 1,2-diphosphacyclopentadienyl manganese complexes. We show that, compared to the standardly used two-pulse primary spin-echo technique, the CPMG experiment can boost the phase memory time up to one order of magnitude, bringing it to above 10 μs at low temperatures. This finding may be important for the implementation of quantum computation protocols on molecular magnets. We discuss a possible interesting analogy with the Zeno's paradox in quantum theory (the Zeno quantum effect), which could be implicit in the CPMG experiment.

  9. Unidirectional, dual-comb lasing under multiple pulse formation mechanisms in a passively mode-locked fiber ring laser.

    PubMed

    Liu, Ya; Zhao, Xin; Hu, Guoqing; Li, Cui; Zhao, Bofeng; Zheng, Zheng

    2016-09-19

    Dual-comb lasers simultaneously generating asynchronous ultrashort pulses could be an intriguing alternative to the current dual-laser comb source. When generated through a common light path, the low common-mode noises and good coherence between the pulse trains could be realized. Here we demonstrate the completely common-path, unidirectional dual-comb lasing using a carbon nanotube saturable absorber with additional pulse narrowing and broadening mechanisms. The interactions between multiple soliton formation mechanisms result in bifurcation into unusual two-pulse states with pulses of four-fold bandwidth difference and tens-of-Hz repetition rate difference. Coherence between the pulses is verified by the asynchronous cross-sampling and dual-comb spectroscopy measurements. PMID:27661880

  10. Polarizabilities of Impurity Doped Quantum Dots Under Pulsed Field: Role of Multiplicative White Noise

    NASA Astrophysics Data System (ADS)

    Saha, Surajit; Ghosh, Manas

    2016-02-01

    We perform a rigorous analysis of the profiles of a few diagonal and off-diagonal components of linear ( α xx , α yy , α xy , and α yx ), first nonlinear ( β xxx , β yyy , β xyy , and β yxx ), and second nonlinear ( γ xxxx , γ yyyy , γ xxyy , and γ yyxx ) polarizabilities of quantum dots exposed to an external pulsed field. Simultaneous presence of multiplicative white noise has also been taken into account. The quantum dot contains a dopant represented by a Gaussian potential. The number of pulse and the dopant location have been found to fabricate the said profiles through their interplay. Moreover, a variation in the noise strength also contributes evidently in designing the profiles of above polarizability components. In general, the off-diagonal components have been found to be somewhat more responsive to a variation of noise strength. However, we have found some exception to the above fact for the off-diagonal β yxx component. The study projects some pathways of achieving stable, enhanced, and often maximized output of linear and nonlinear polarizabilities of doped quantum dots driven by multiplicative noise.

  11. Effects of frame rate and image resolution on pulse rate measured using multiple camera imaging photoplethysmography

    NASA Astrophysics Data System (ADS)

    Blackford, Ethan B.; Estepp, Justin R.

    2015-03-01

    Non-contact, imaging photoplethysmography uses cameras to facilitate measurements including pulse rate, pulse rate variability, respiration rate, and blood perfusion by measuring characteristic changes in light absorption at the skin's surface resulting from changes in blood volume in the superficial microvasculature. Several factors may affect the accuracy of the physiological measurement including imager frame rate, resolution, compression, lighting conditions, image background, participant skin tone, and participant motion. Before this method can gain wider use outside basic research settings, its constraints and capabilities must be well understood. Recently, we presented a novel approach utilizing a synchronized, nine-camera, semicircular array backed by measurement of an electrocardiogram and fingertip reflectance photoplethysmogram. Twenty-five individuals participated in six, five-minute, controlled head motion artifact trials in front of a black and dynamic color backdrop. Increasing the input channel space for blind source separation using the camera array was effective in mitigating error from head motion artifact. Herein we present the effects of lower frame rates at 60 and 30 (reduced from 120) frames per second and reduced image resolution at 329x246 pixels (one-quarter of the original 658x492 pixel resolution) using bilinear and zero-order downsampling. This is the first time these factors have been examined for a multiple imager array and align well with previous findings utilizing a single imager. Examining windowed pulse rates, there is little observable difference in mean absolute error or error distributions resulting from reduced frame rates or image resolution, thus lowering requirements for systems measuring pulse rate over sufficient length time windows.

  12. Pulse

    MedlinePlus

    ... resting for at least 10 minutes. Take the exercise heart rate while you are exercising. ... pulse rate can help determine if the patient's heart is pumping. ... rate gives information about your fitness level and health.

  13. Compression, spectral broadening, and collimation in multiple, femtosecond pulse filamentation in atmosphere

    NASA Astrophysics Data System (ADS)

    Palastro, J. P.; Antonsen, T. M., Jr.; Milchberg, H. M.

    2012-09-01

    A sequence of femtosecond laser pulses propagating through atmosphere and delayed near the rotational recurrence period of N2 can resonantly drive molecular alignment. Through the polarization density, the molecular alignment provides an index of refraction contribution that acts as a lens copropagating with each laser pulse. Each pulse enhances this contribution to the index, modifying the propagation of subsequent pulses. Here we present propagation simulations of femtosecond pulse sequences in which we have implemented a self-consistent calculation of the rotational polarization density using linearized density matrix theory. We find that a femtosecond pulse sequence can enhance pulse compression or collimation in atmosphere. In particular, when the pulses are delayed by exactly the rotational recurrence period, each subsequent pulse is increasingly compressed due to a combination of spectral broadening and negative dispersion. Alternatively, when the intensity peak of each pulse is centered on the maximum index generated by the preceding pulses, each pulse is increasingly collimated.

  14. Gamma-ray pulse height spectrum analysis on systems with multiple Ge detectors using spectrum summing

    SciTech Connect

    Killian, E.W.

    1997-11-01

    A technique has been developed at the Idaho National Engineering Laboratory to sum high resolution gamma-ray pulse spectra from systems with multiple Ge detectors. Lockheed Martin Idaho Technologies Company operates a multi-detector spectrometer configuration at the Stored Waste Examination Pilot Plant facility which is used to characterize the radionuclide contents in waste drums destined for shipment to Waste Isolation Pilot Plant. This summing technique was developed to increase the sensitivity of the system, reduce the count times required to properly quantify the radio-nuclides and provide a more consistent methodology for combining data collected from multiple detectors. In spectrometer systems with multiple detectors looking at non homogeneous waste forms it is often difficult to combine individual spectrum analysis results from each detector to obtain a meaningful result for the total waste container. This is particularly true when the counting statistics in each individual spectrum are poor. The spectrum summing technique adds the spectra collected by each detector into a single spectrum which has better counting statistics than each individual spectrum. A normal spectral analysis program can then be used to analyze the sum spectrum to obtain radio-nuclide values which have smaller errors and do not have to be further manipulated to obtain results for the total waste container. 2 refs., 2 figs.

  15. Overlap in Bibliographic Databases.

    ERIC Educational Resources Information Center

    Hood, William W.; Wilson, Concepcion S.

    2003-01-01

    Examines the topic of Fuzzy Set Theory to determine the overlap of coverage in bibliographic databases. Highlights include examples of comparisons of database coverage; frequency distribution of the degree of overlap; records with maximum overlap; records unique to one database; intra-database duplicates; and overlap in the top ten databases.…

  16. Manipulating antiferromagnets with magnetic fields: Ratchet motion of multiple domain walls induced by asymmetric field pulses

    NASA Astrophysics Data System (ADS)

    Gomonay, O.; Kläui, M.; Sinova, J.

    2016-10-01

    Future applications of antiferromagnets (AFs) in many spintronics devices rely on the precise manipulation of domain walls. The conventional approach using static magnetic fields is inefficient due to the low susceptibility of AFs. Recently proposed electrical manipulation with spin-orbit torques is restricted to metals with a specific crystal structure. Here, we propose an alternative, broadly applicable approach: using asymmetric magnetic field pulses to induce controlled ratchet motion of AF domain walls. The efficiency of this approach is based on three peculiarities of AF dynamics. First, a time-dependent magnetic field couples with an AF order parameter stronger than a static magnetic field, which leads to higher mobility of the domain walls. Second, the rate of change of the magnetic field couples with the spatial variation of the AF order parameter inside the domain, and this enables a synchronous motion of multiple domain walls with the same structure. Third, tailored asymmetric field pulses in combination with static friction can prevent backward motion of domain walls and thus lead to the desired controlled ratchet effect. The proposed use of an external field, rather than internal spin-orbit torques, avoids any restrictions on size, conductivity, and crystal structure of the AF material. We believe that our approach paves a way for the development of AF-based devices based on the controlled motion of AF domain walls.

  17. Analysis on the damage threshold of MgO:LiNbO3 crystals under multiple femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Su, Zhuolin; Meng, Qinglong; Zhang, Bin

    2016-10-01

    An improved theoretical model of the interaction between multiple femtosecond laser pulses and MgO:LiNbO3 crystals with different doping concentrations has been established based on the classical two-temperature model. The evolutions of electron and lattice temperature with the duration, the repetition frequency and the numbers of multiple femtosecond laser pulses in MgO:LiNbO3 crystals have been simulated numerically by the Crank-Nicholson implicit finite-difference method. Furthermore, the variations of the damage threshold of MgO:LiNbO3 crystals with the parameters of multiple femtosecond laser pulses at different doping concentrations, as well as the influence of doping concentration on damage threshold have also been analyzed. The results show that, the damage threshold of MgO:LiNbO3 crystals increases with the increasing of the duration of the femtosecond laser pulse. The damage threshold of MgO:LiNbO3 crystals first decreases with the increasing of the numbers and the pulse repetition frequency of the laser pulses and then tends to be a constant. The damage threshold of a small amount of MgO-doped LiNbO3 crystals is higher than that of undoped LiNbO3 crystals. Consequently, the resist damage capability of LiNbO3 crystals can be enhanced by doping appropriate MgO in many practical applications.

  18. A preliminary comparison of the transient effects of single versus multiple q-switched doubled-neodymium laser pulses

    NASA Astrophysics Data System (ADS)

    Previc, Fred H.

    1987-09-01

    A comparison between the effects of single and multiple laser pulse-trains of equivalent energy was performed. Visual evoked potentials (VEPS) recorded bipolarly from the visual cortex of two rhesus monkeys in response to a counterphasing grating were used to assess the magnitude of the visual loss following four types of exposures: single and multiple pulses with total energies equal to 50 and 500 percent of the maximum permissible exposure (MPE) standard for humans. The results showed that the effects of a series of laser flashes presented within 200 ms are similar to those of a single laser flash whose energy is equivalent to the cumulative energy of the multiple-pulse exposure.

  19. Differential pulse amplitude modulation for multiple-input single-output OWVLC

    NASA Astrophysics Data System (ADS)

    Yang, S. H.; Kwon, D. H.; Kim, S. J.; Son, Y. H.; Han, S. K.

    2015-01-01

    White light-emitting diodes (LEDs) are widely used for lighting due to their energy efficiency, eco-friendly, and small size than previously light sources such as incandescent, fluorescent bulbs and so on. Optical wireless visible light communication (OWVLC) based on LED merges lighting and communications in applications such as indoor lighting, traffic signals, vehicles, and underwater communications because LED can be easily modulated. However, physical bandwidth of LED is limited about several MHz by slow time constant of the phosphor and characteristics of device. Therefore, using the simplest modulation format which is non-return-zero on-off-keying (NRZ-OOK), the data rate reaches only to dozens Mbit/s. Thus, to improve the transmission capacity, optical filtering and pre-, post-equalizer are adapted. Also, high-speed wireless connectivity is implemented using spectrally efficient modulation methods: orthogonal frequency division multiplexing (OFDM) or discrete multi-tone (DMT). However, these modulation methods need additional digital signal processing such as FFT and IFFT, thus complexity of transmitter and receiver is increasing. To reduce the complexity of transmitter and receiver, we proposed a novel modulation scheme which is named differential pulse amplitude modulation. The proposed modulation scheme transmits different NRZ-OOK signals with same amplitude and unit time delay using each LED chip, respectively. The `N' parallel signals from LEDs are overlapped and directly detected at optical receiver. Received signal is demodulated by power difference between unit time slots. The proposed scheme can overcome the bandwidth limitation of LEDs and data rate can be improved according to number of LEDs without complex digital signal processing.

  20. Multi-pulse frequency shifted (MPFS) multiple access modulation for ultra wideband

    DOEpatents

    Nekoogar, Faranak; Dowla, Farid U.

    2012-01-24

    The multi-pulse frequency shifted technique uses mutually orthogonal short duration pulses o transmit and receive information in a UWB multiuser communication system. The multiuser system uses the same pulse shape with different frequencies for the reference and data for each user. Different users have a different pulse shape (mutually orthogonal to each other) and different transmit and reference frequencies. At the receiver, the reference pulse is frequency shifted to match the data pulse and a correlation scheme followed by a hard decision block detects the data.

  1. Supporting Uavs in Low Visibility Conditions by Multiple-Pulse Laser Scanning Devices

    NASA Astrophysics Data System (ADS)

    Djuricic, A.; Jutzi, B.

    2013-04-01

    Unmanned Aerial Vehicles (UAVs) are nowadays promising platforms for capturing spatial information, because they are low cost solutions, which are easy to bring to the surveying field and can operate automatically. Usually these devices are equipped with visual sensors to support the navigation of the platform or to transmit observations of the environment to the operator. By collecting the data and processing the captured images even an estimation of the observed environment in form of 3D information is available. Therefore Simultaneous Localization and Mapping (SLAM) algorithms are well known for processing data which is captured in the visible domain. However, situations can occur where gathering visual information is difficult due to given limitations in form of low visibility. For example if soft obstacles in form of translucent materials are given in disaster scenarios with smoke and operating has still to be ensured, active optical sensors (e.g. laser scanners) are gaining interest because they can penetrate the soft obstacle and allow to acquire information behind it. A new lightweight (210 g), simplified and minimized scanning unit is now available which allows to capture multiple reflections for each transmitted laser pulse, namely the Hokuyo UTM-30LX-EW. With such a device, it is possible to overcome the above mentioned restrictions or limitations of low visibility by soft obstacles and even measure under critical circumstances. A multi-pulse system can provide accurate measurements on, within, and behind the soft obstacle. This research focuses on investigating the ability and performance of a laser scanner to penetrate the soft obstacle. Thus, investigations on a system that overcomes these limitations and provides a solution will be given. First promising experimental results considering soft obstacle are described.

  2. 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

  3. Multiple current peaks in room-temperature atmospheric pressure homogenous dielectric barrier discharge plasma excited by high-voltage tunable nanosecond pulse in air

    SciTech Connect

    Yang, De-Zheng; Wang, Wen-Chun; Zhang, Shuai; Tang, Kai; Liu, Zhi-jie; Wang, Sen

    2013-05-13

    Room temperature homogenous dielectric barrier discharge plasma with high instantaneous energy efficiency is acquired by using nanosecond pulse voltage with 20-200 ns tunable pulse width. Increasing the voltage pulse width can lead to the generation of regular and stable multiple current peaks in each discharge sequence. When the voltage pulse width is 200 ns, more than 5 organized current peaks can be observed under 26 kV peak voltage. Investigation also shows that the organized multiple current peaks only appear in homogenous discharge mode. When the discharge is filament mode, organized multiple current peaks are replaced by chaotic filament current peaks.

  4. Seeding for pervasively overlapping communities

    NASA Astrophysics Data System (ADS)

    Lee, Conrad; Reid, Fergal; McDaid, Aaron; Hurley, Neil

    2011-06-01

    In some social and biological networks, the majority of nodes belong to multiple communities. It has recently been shown that a number of the algorithms specifically designed to detect overlapping communities do not perform well in such highly overlapping settings. Here, we consider one class of these algorithms, those which optimize a local fitness measure, typically by using a greedy heuristic to expand a seed into a community. We perform synthetic benchmarks which indicate that an appropriate seeding strategy becomes more important as the extent of community overlap increases. We find that distinct cliques provide the best seeds. We find further support for this seeding strategy with benchmarks on a Facebook network and the yeast interactome.

  5. Hemodynamics in coronary arteries with overlapping stents.

    PubMed

    Rikhtegar, Farhad; Wyss, Christophe; Stok, Kathryn S; Poulikakos, Dimos; Müller, Ralph; Kurtcuoglu, Vartan

    2014-01-22

    Coronary artery stenosis is commonly treated by stent placement via percutaneous intervention, at times requiring multiple stents that may overlap. Stent overlap is associated with increased risk of adverse clinical outcome. While changes in local blood flow are suspected to play a role therein, hemodynamics in arteries with overlapping stents remain poorly understood. In this study we analyzed six cases of partially overlapping stents, placed ex vivo in porcine left coronary arteries and compared them to five cases with two non-overlapping stents. The stented vessel geometries were obtained by micro-computed tomography of corrosion casts. Flow and shear stress distribution were calculated using computational fluid dynamics. We observed a significant increase in the relative area exposed to low wall shear stress (WSS<0.5 Pa) in the overlapping stent segments compared both to areas without overlap in the same samples, as well as to non-overlapping stents. We further observed that the configuration of the overlapping stent struts relative to each other influenced the size of the low WSS area: positioning of the struts in the same axial location led to larger areas of low WSS compared to alternating struts. Our results indicate that the overlap geometry is by itself sufficient to cause unfavorable flow conditions that may worsen clinical outcome. While stent overlap cannot always be avoided, improved deployment strategies or stent designs could reduce the low WSS burden.

  6. Experimental study of multiple-intermittent cryogen spurts and laser pulses for the treatment of port wine stain birthmarks

    NASA Astrophysics Data System (ADS)

    Aguilar, Guillermo; Choi, Bernard; Viator, John A.; Andersen, Dan; Nelson, J. Stuart

    2003-06-01

    Cryogen spray cooling (CSC) is used to minimize the risk of epidermal damage during pulsed laser treatment of port wine stain (PWS) birthmarks. Unfortunately, the current approach to CSC does not provide the necessary epidermal protection for all patients, particularly those with darker skin types. Therefore, alternative approaches need to be sought to improve PWS laser therapy. On a previous numerical study we showed that using multiple-intermittent CSC spurts and laser pulses could permit, under certain conditions, the use of higher laser doses while providing sufficient epidermal protection. In this study we show some results of ongoing experimental to study the feasibility of implementing clinically such an approach.

  7. Substitution Structures of Multiple Silicon-Containing Species by Chirped Pulse Ftmw Spectroscopy

    NASA Astrophysics Data System (ADS)

    Seifert, Nathan A.; Lobsiger, Simon; Pate, Brooks H.; Guirgis, Gamil A.; Overby, Jason S.; Durig, James R.

    2013-06-01

    The structures of CH_{3}SiHF-NCO, 1-X-silacyclopropane (X = cyano, isocyanato), 1,1,3,3-tetrafluoro-1,3-disilacyclopentane and its hydrogen analogue (1,3-disilacyclopentane), and 1-isocyanato-silacyclohexane have been studied by chirped pulse FTMW spectroscopy in the 6-18 GHz band. Multiple conformers for some of the species were also detected: anti and gauche for both silacyclopropyl species, and axial and equatorial for the silacyclohexane. Heavy atom substitution structures were determined, with all possible single ^{13}C, ^{29}Si/^{30}Si and most ^{15}N isotopologues assigned in natural abundance. Nitrogen hyperfine and distortion parameters for all species have been determined, and the barrier for methyl internal rotation for CH_{3}SiHF-NCO has been determined as 481(20) cm^{-1}, close to the B3LYP/6-311++g(d,p) barrier of 450 cm^{-1}. A summary of the microwave and structural results for the aforementioned molecules will be presented. In addition, emphasis will be placed on the use of previously discussed automated fitting techniques as a means of efficient and fast assignment of isotopologues in spectra with increasingly large line densities. A. L. Steber, J. L. Neill, M. T. Muckle, B. H. Pate, D. F. Plusquellic, V. Lattanzi, S. Spezzano, M. C. McCarthy. 65th OSU Int. Symp. On Mol. Spectrosc., Columbus, OH, 2010, TC10. E. B. Kent, M. N. McCabe, M. A. Phillips, B. P. Gordon, S. T. Shipman. 66th OSU Int. Symp. On Mol. Spectrosc., Columbus, OH, 2011, RH01.

  8. Experimental study of resolution of proton chemical shifts in solids: Combined multiple pulse NMR and magic-angle spinning

    SciTech Connect

    Ryan, L.M.; Taylor, R.E.; Paff, A.J.; Gerstein, B.C.

    1980-01-01

    High-resolution nuclear magnetic resonance spectra of protons in rigid, randomly oriented solids have been measured using combined homonuclear dipolar decoupling (via multiple pulse techniques) and attenuation of chemical shift anisotropies (via magic-angle sample spinning). Under those conditions, isotropic proton chemical shifts were recorded for a variety of chemical species, with individual linewidths varying from about 55 to 110 Hz (1--2 ppm). Residual line broadening was due predominately to (i) magnetic-field instability and inhomogeneity, (ii) unresolved proton--proton spin couplings, (iii) chemical shift dispersion, (iv) residual dipolar broadening, and (v) lifetime broadening under the multiple pulse sequences used. The magnitudes of those effects and the current limits of resolution for this experiment in our spectrometer have been investigated. The compounds studied included organic solids (4, 4'-dimethylbenzophenone, 2, 6-dimethylbenzoic acid, and aspirin), polymers (polystyrene and polymethylmethacrylate), and the vitrain portion of a bituminous coal.

  9. Varied magnetic field, multiple-pulse, and magic-angle spinning proton nuclear magnetic resonance study of muscle water

    SciTech Connect

    Fung, B.M.; Ryan, L.M.; Gerstein, B.C.

    1980-02-01

    The nuclear magnetic resonance linewidth of /sup 1/H in water of frog muscle was studied as a function of magnetic field strength and angle of orientation. The results suggest that the observed spectra are dominated by demagnetization field anisotropy and dispersion, but a small static dipolar interaction of the order of a few hertz may be present. Data from line-narrowing, multiple-pulse experiments also indicate the presence of a small dipolar broadening.

  10. Effects of electron relaxation on multiple harmonic generation from metal surfaces with femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Karatzas, N. E.; Georges, A. T.

    2006-11-01

    Calculations are presented for the first four (odd and even) harmonics of an 800 nm laser from a gold surface, with pulse widths ranging from 100 down to 14 fs. For peak laser intensities above 1 GW/cm 2 the harmonics are enhanced because of a partial depletion of the initial electron states. At 10 11 W/cm 2 of peak laser intensity the calculated conversion efficiency for 2nd-harmonic generation is 3 × 10 -9, while for the 5th-harmonic it is 10 -10. The generated harmonic pulses are broadened and delayed relative to the laser pulse because of the finite relaxation times of the excited electronic states. The finite electron relaxation times cause also the broadening of the autocorrelations of the laser pulses obtained from surface harmonic generation by two time-delayed identical pulses. Comparison with recent experimental results shows that the response time of an autocorrelator using nonlinear optical processes in a gold surface is shorter than the electron relaxation times. This seems to indicate that for laser pulses shorter than ˜30 fs, the fast nonresonant channel for multiphoton excitation via continuum-continuum transitions in metals becomes important as the resonant channel becomes slow (relative to the laser pulse) and less efficient.

  11. Alignment enhancement of molecules embedded in helium nanodroplets by multiple laser pulses

    NASA Astrophysics Data System (ADS)

    Christiansen, Lars; Nielsen, Jens H.; Pentlehner, Dominik; Underwood, Jonathan G.; Stapelfeldt, Henrik

    2015-11-01

    We show experimentally that field-free one-dimensional (1D) alignment of 1,4-diiodobenzene molecules embedded in helium nanodroplets, induced by a single, linearly polarized 200-fs laser pulse, can be significantly enhanced by using two or four optimally synchronized laser pulses. The strongest degree of 1D alignment is obtained with four pulses and gives >0.60 . Besides the immediate implications for molecular frame studies, our results pave the way for more general manipulation of rotational motion of molecules in He droplets.

  12. Experimental demonstration of noncontact pulse wave velocity monitoring using multiple Doppler radar sensors.

    PubMed

    Lu, Li; Li, Changzhi; Lie, Donald Y C

    2010-01-01

    In this paper, two Doppler radars are used to monitor the pulse movements at the heart and the calf in order to measure the pulse wave velocity (PWV) wirelessly. Both simulation and experiment have been performed to demonstrate the feasibility of the proposed noncontact PWV monitoring. A three-stage calibration procedure, including DC offset calibration, circuit delay calibration and antenna radiation pattern calibration, has been developed for reliable long-term PWV monitoring. The measurement results have been verified by wired contact measurement with pulse transducers.

  13. Multiple continuous-wave and pulsed modes of a figure-of-eight fibre laser

    NASA Astrophysics Data System (ADS)

    Pottiez, O.; Martinez-Rios, A.; Monzon-Hernandez, D.; Salceda-Delgado, G.; Hernandez-Garcia, J. C.; Ibarra-Escamilla, B.; Kuzin, E. A.

    2013-03-01

    We study experimentally a figure-of-eight fibre laser including a polarization-imbalanced nonlinear optical loop mirror and a Mach-Zehnder optical filter formed by two fibre tapers placed in series. Depending on the adjustments of two wave retarders included in the setup, different modes of operation of the laser are found. In continuous-wave mode, tunable single-wavelength operation as well as multiwavelength lasing are observed. For some adjustments, self-pulsing also takes place, although the pulses are very unstable. Finally, for some adjustments a mechanical stimulation (a kick) leads to the onset of passive mode locking. Measurements reveal that the mode-locked pulses actually are noise-like pulses. Both stable fundamental mode locking and second-harmonic mode locking with particular dynamics were obtained. In this work, we analyse how simple wave plate adjustments can lead to such a variety of operational modes of the fibre laser.

  14. Comparison of time of arrival vs. multiple parameter based radar pulse train deinterleavers

    NASA Astrophysics Data System (ADS)

    Lin, Samuel; Thompson, Michael; Davezac, Stephen; Sciortino, John C., Jr.

    2006-05-01

    This paper provides a comparison of the two main techniques currently in use to solve the problem of radar pulse train deinterleaving. Pulse train deinterleaving separates radar pulse trains into the tracks or bins associated with the detected emitters. The two techniques are simple time of arrival (TOA) histogramming and multi-parametric analysis. TOA analysis uses only the time of arrival (TOA) parameter of each pulse to deinterleave radar pulse trains. Such algorithms include Cumulative difference (CDIF) histogramming and Sequential difference (SDIF) histogramming. Multiparametric analysis utilizes any combination of the following parameters: TOA, radio frequency (RF), pulse width (PW), and angle of arrival (AOA). These techniques use a variety of algorithms, such as Fuzzy Adaptive Resonance Theory (Fuzzy-ART), Fuzzy Min-Max Clustering (FMMC), Integrated Adaptive Fuzzy Clustering (IAFC) and Fuzzy Adaptive Resonance Theory Map (Fuzzy-ARTMAP) to compare the pulses to determine if they are from the same emitter. Good deinterleaving is critical since inaccurate deinterleaving can lead to misidentification of emitters. The deinterleaving techniques evaluated in this paper are a sizeable and representative sample of both US and international efforts developed in the UK, Canada, Australia and Yugoslavia. Mardia [1989] and Milojevic and Popovich [1992] shows some of the early work in TOA-based deinterleaving. Ray [1997] demonstrates some of the more recent work in this area. Multi-parametric techniques are exemplified by Granger, et al [1998] and Thompson and Sciortino [2004]. This paper will provide an analysis of the algorithms and discuss the results obtained from the referenced articles. The algorithms will be evaluated for usefulness in deinterleaving pulse trains from agile radars.

  15. Separation of overlapping linear frequency modulated (LFM) signals using the fractional fourier transform.

    PubMed

    Cowell, David M J; Freear, Steven

    2010-10-01

    Linear frequency modulated (LFM) excitation combined with pulse compression provides an increase in SNR at the receiver. LFM signals are of longer duration than pulsed signals of the same bandwidth; consequently, in many practical situations, maintaining temporal separation between echoes is not possible. Where analysis is performed on individual LFM signals, a separation technique is required. Time windowing is unable to separate signals overlapping in time. Frequency domain filtering is unable to separate signals with overlapping spectra. This paper describes a method to separate time-overlapping LFM signals through the application of the fractional Fourier transform (FrFT), a transform operating in both time and frequency domains. A short introduction to the FrFT and its operation and calculation are presented. The proposed signal separation method is illustrated by application to a simulated ultrasound signal, created by the summation of multiple time-overlapping LFM signals and the component signals recovered with ±0.6% spectral error. The results of an experimental investigation are presented in which the proposed separation method is applied to time-overlapping LFM signals created by the transmission of a LFM signal through a stainless steel plate and water-filled pipe.

  16. A lower bound on PET timing estimation with pulse pileup

    SciTech Connect

    Hero, A.O. . Dept. of Electrical Engineering and Computer Science); Clinthorne, N.H.; Rogers, W.L. . Div. of Nuclear Medicine)

    1991-04-01

    Pulse pileup is an important limiting factor on coincidence detection and timing estimation performance in conventional and time of flight (TOF) PET. In this paper the authors derive a Cramer-Rao (CR) lower found on timing estimator mean-square-error (MSE) when there are multiple overlapping single photon response (SPR) pulses within the photo-detector coincidence window. This bound is then used to study the loss in achievable timing resolution due to varying amounts of pulse overlap. The case of a bi-exponential BGO/Burle 8850 SPR is then considered. The authors show that in this case timing resolution need not degrade significantly even when pulse overlap is quite severe: up to approximately 20% overlap of the leading edges of the overlapping pulses can be tolerated with less than a 25% degradation in achievable timing resolution. This suggests that multiple event separation and improved coincidence resolving time can be attained well beyond the photon saturation limit of current scintillation detectors.

  17. Parametric study of the damage ring pattern in fused silica induced by multiple longitudinal modes laser pulses

    SciTech Connect

    Chambonneau, M. Grua, P.; Rullier, J.-L.; Lamaignère, L.; Natoli, J.-Y.

    2015-03-14

    With the use of multiple longitudinal modes nanosecond laser pulses at 1064 nm, laser damage sites at the exit surface of fused silica clearly and systematically exhibit ring patterns. It has been shown in our previous works that the apparent chronology of rings was closely related to the temporal shape of the laser pulses. This particular correspondence had suggested an explanation of the ring morphology formation based on the displacement of an ionization front in the surrounding air. To provide a former basis for this hypothesis and deeper understanding of ring pattern formation, additional experiments have been performed. First, the impact of fluence has been investigated, revealing that a wide variety of damage sites are produced within a very narrow fluence range; this fact involves the chronology of appearance of a surface plasma during the laser pulse. The sizes of the damage sites are proportional to the fluence of their expansion occurring between the beginning of the plasma and the end of the laser pulse. Second, specific experiments have been carried out at different angles of incidence, resulting in egg-shaped patterns rather than circular ones. This behavior can be explained by our previous hypothesis of creation of a plasma in air, its expansion being tightly conditioned by the illumination angle. This series of experiments, in which the angle of incidence is varied up to 80°, permits us to link quantitatively the working hypothesis of ionization front propagation with theoretical hydrodynamics modeling.

  18. Controlling the fast electron divergence in a solid target with multiple laser pulses.

    PubMed

    Volpe, L; Feugeas, J-L; Nicolai, Ph; Santos, J J; Touati, M; Breil, J; Batani, D; Tikhonchuk, V

    2014-12-01

    Controlling the divergence of laser-driven fast electrons is compulsory to meet the ignition requirements in the fast ignition inertial fusion scheme. It was shown recently that using two consecutive laser pulses one can improve the electron-beam collimation. In this paper we propose an extension of this method by using a sequence of several laser pulses with a gradually increasing intensity. Profiling the laser-pulse intensity opens a possibility to transfer to the electron beam a larger energy while keeping its divergence under control. We present numerical simulations performed with a radiation hydrodynamic code coupled to a reduced kinetic module. Simulation with a sequence of three laser pulses shows that the proposed method allows one to improve the efficiency of the double pulse scheme at least by a factor of 2. This promises to provide an efficient energy transport in a dense matter by a collimated beam of fast electrons, which is relevant for many applications such as ion-beam sources and could present also an interest for fast ignition inertial fusion. PMID:25615206

  19. Multiple-beam, pulse-burst, passively Q-switched ceramic Nd:YAG laser under micro-lens array pumping.

    PubMed

    Ma, Yufei; He, Ying; Yu, Xin; Li, Xudong; Li, Jiang; Yan, Renpeng; Peng, Jiangbo; Zhang, Xinlu; Sun, Rui; Pan, Yubai; Chen, Deying

    2015-09-21

    A novel four-beam (named laserI, laser II, laser III and laser IV, respectively), passively Q-switched, pulse-burst ceramic Nd:YAG laser under 2 × 2 micro-lens array pumping was demonstrated for the purpose of laser-induced plasma ignition (LIPI). Multiple-beam output together with pulse-burst mode in which both high repetition rate and high pulse energy can be realized simultaneously were obtained to greatly improve the performance of LIPI. The pulse-burst contained a maximum of 5 pulses, 3 pulses, 2 pulses and 3 pulses for laserI, laser II, laser III and laser IV, respectively, and the corresponding repetition rate of laser pulses in pulse-burst was 10.8 kHz, 7.2 kHz, 6.8 kHz and 5.2 kHz, respectively. The output energy for single laser pulse in pulse-burst was in the range of 0.12 mJ to 0.22 mJ. PMID:26406695

  20. Simultaneous SU(2) rotations on multiple quantum dot exciton qubits using a single shaped pulse

    NASA Astrophysics Data System (ADS)

    Mathew, Reuble; Yang, Hong Yi Shi; Hall, Kimberley C.

    2015-10-01

    Recent experimental demonstration of a parallel (π ,2 π ) single qubit rotation on excitons in two distant quantum dots [Nano Lett. 13, 4666 (2013), 10.1021/nl4018176] is extended in numerical simulations to the design of pulses for more general quantum state control, demonstrating the feasibility of full SU(2) rotations of each exciton qubit. Our results show that simultaneous high-fidelity quantum control is achievable within the experimentally accessible parameter space for commercial Fourier-domain pulse shaping systems. The identification of a threshold of distinguishability for the two quantum dots (QDs) for achieving high-fidelity parallel rotations, corresponding to a difference in transition energies of ˜0.25 meV , points to the possibility of controlling more than 10 QDs with a single shaped optical pulse.

  1. Modification of narrow ablating capillaries under the influence of multiple femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Gubin, K. V.; Lotov, K. V.; Trunov, V. I.; Pestryakov, E. V.

    2016-09-01

    Powerful femtosecond laser pulses that propagate through narrow ablating capillaries cause modification of capillary walls, which is studied experimentally and theoretically. At low intensities, the laser-induced periodic surface structures and porous coating composed of sub-micron particles appear on the walls. At higher intensities, the surface is covered by deposited droplets of the size up to 10 μm. In both cases, the ablated material forms a solid plug that completely blocks the capillary after several hundreds or thousands of pulses. The suggested theoretical model indicates that the plug formation is a universal effect. It must take place in any narrow tube subject to ablation under the action of short laser pulses.

  2. Multiple-frequency injection-seeded nanosecond pulsed laser without parasitic intensity modulation.

    PubMed

    Penninckx, D; Luce, J; Diaz, R; Bonville, O; Courchinoux, R; Lamaignère, L

    2016-07-15

    Thanks to a phase-modulated injection seeder, we report the operation of a nanosecond Nd:YAG Q-switched laser with pulses having both a large spectral bandwidth and a smooth temporal waveform. Because of the smooth temporal waveform, such pulses allow, for instance, reducing the impact of the Kerr effect and, because of the large spectral bandwidth, suppressing stimulated Brillouin scattering. We conducted a parametric study of the features of the generated pulses versus the injection conditions. We show that, as opposed to the central frequency (wavelength) of the seeder, the phase modulation frequency has to be carefully chosen, but it is not a critical parameter and does not require any particular feedback. PMID:27420504

  3. Multiple DNA-binding factors interact with overlapping specificities at the aryl hydrocarbon response element of the cytochrome P450IA1 gene.

    PubMed Central

    Saatcioglu, F; Perry, D J; Pasco, D S; Fagan, J B

    1990-01-01

    to lack nuclear Ah receptor, expressed normal levels of XF1 and XF2, suggesting that the former factor is genetically distinct from the latter two; and (v) a divalent metal ion, probably Zn2+, is known to be an essential cofactor for the Ah receptor but was not required for the DNA-binding activities of XF1 and XF2. Together, these findings indicate that the Ah receptor is distinct from XF1 and XF2, while the latter two activities may be related. Because the DNA-binding domains of these three factors overlap substantially, their binding to XREs is probably mutually exclusive, which suggests that the interplay of these factors at Ah response elements may be important to the regulation of CYP1A1 gene transcription. The results of preliminary transfection experiments with constructs harboring XREs upstream of the chloramphenicol acetyltransferase gene driven by a minimal simian virus 40 promoter are presented that are consistent with this hypothesis. Images PMID:2174107

  4. Analysis of laser return pulse from multilayered objects

    NASA Astrophysics Data System (ADS)

    Hollinger, Jim; Vessey, Alyssa; Close, Ryan; Middleton, Seth; Williams, Kathryn; Rupp, Ronald; Nguyen, Son

    2016-05-01

    Commercial Lidar often focus on reporting the range associated with the strongest laser return pulse, first return pulse, or last return pulse. This technique works well when observing discrete objects separated by a distance greater than the laser pulse length. However, multiple reflections due to more closely layered objects produce overlapping laser return pulses. Resolving the multi-layered object ranges in the resulting complex waveforms is the subject of this paper. A laboratory setup designed to investigate the laser return pulse produced by multi-layered objects is described along with a comparison of a simulated laser return pulse and the corresponding digitized laser return pulse. Variations in the laboratory setup are used to assess different strategies for resolving multi-layered object ranges and how this additional information can be applied to detecting objects partially obscured in vegetation.

  5. Multiple diagnosis based on photoplethysmography: hematocrit, SpO2, pulse, and respiration

    NASA Astrophysics Data System (ADS)

    Yoon, Gilwon; Lee, Jong Y.; Jeon, Kye Jin; Park, Kun-Kook; Yeo, Hyung S.; Hwang, Hyun T.; Kim, Hong S.; Hwang, In-Duk

    2002-09-01

    Photo-plethysmography measures pulsatile blood flow in real-time and non-invasively. One of widely known applications of PPG is the measurement of saturated oxygen in arterial blood(SpO2). In our work, using several wavelengths more than those used in a pulse oximeter, an algorithm and instrument have been developed to measure hematocrit, saturated oxygen, pulse and respiratory rates simultaneously. To predict hematocrit, a dedicated algorithm is developed based on scattering of RBC and a protocol for detecting outlier signals is used to increase accuracy and reliability. Digital filtering techniques are used to extract respiratory rate signals. Utilization of wavelengths under 1000nm and a multi-wavelength LED array chip and digital-oriented electronics enable us to make a compact device. Our preliminary clinical trials show that the achieved percent errors are +/-8.2% for hematocrit when tested with 594 persons, R2 for SpO2 fitting is 0.99985 when tested with a Bi-Tek pulse oximeter simulator and the SpO2 error for in vivo test is +/-2.5% over the range of 75~100%. The error of pulse rates is less than +/-5%. We obtained a positive predictive value of 96% for respiratory rates in qualitative analysis.

  6. Parameters of radio pulses of cloud-to-ground multiple-stroke lightning discharges in Northeast Asia

    NASA Astrophysics Data System (ADS)

    Tarabukina, L. D.; Kozlov, V. I.

    2016-05-01

    Parameters of radio pulses from multiple-stroke lightning discharges arising on the territory of Yakutia and in Transbaikalia are estimated. The number of cloud-to-ground return strokes per lightning reaches 11, on average, 4.2 (without allowance for the cases of single lightnings) for Yakutia and up to 15 for Transbaikalia. The time interval between the subsequent strokes was on average 43 ms. A peak value of signals of subsequent strokes averages 0.5 of the value for the first stroke.

  7. Reliable source of conditional states from single-mode pulsed thermal fields by multiple-photon subtraction

    SciTech Connect

    Allevi, A.; Andreoni, A.; Bondani, M.; Genoni, M. G.; Olivares, S.

    2010-07-15

    We demonstrate the effect of multiple-photon subtraction on the generation of conditional states in the pulsed regime. Our experimental scheme relies on a beam splitter (BS) and a pair of linear photodetectors that are able to resolve up to tens of photons. We use a single-mode thermal field at the input port of the BS to test the reliability of our scheme, and we show good agreement with the theory by fully characterizing the conditional outgoing states in terms of photon-number statistics and non-Gaussianity.

  8. Refractive index modulation of Sb70Te30 phase-change thin films by multiple femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Lei, Kai; Wang, Yang; Jiang, Minghui; Wu, Yiqun

    2016-05-01

    In this study, the controllable effective refractive index modulation of Sb70Te30 phase-change thin films between amorphous and crystalline states was achieved experimentally by multiple femtosecond laser pulses. The modulation mechanism was analyzed comprehensively by a spectral ellipsometer measurement, surface morphology observation, and two-temperature model calculations. We numerically demonstrate the application of the optically modulated refractive index of the phase-change thin films in a precisely adjustable color display. These results may provide further insights into ultrafast phase-transition mechanics and are useful in the design of programmable photonic and opto-electrical devices based on phase-change memory materials.

  9. A multiple pulse zero crossing NMR technique, and its application to F-19 chemical shift measurements in solids

    NASA Technical Reports Server (NTRS)

    Burum, D. P.; Elleman, D. D.; Rhim, W.-K.

    1978-01-01

    A simple multiple-pulse 'zero crossing technique' for accurately determining the first moment of a solid-state NMR spectrum is introduced. This technique was applied to obtain the F-19 chemical shift versus pressure curves up to 5 kbar for single crystals of CaF2 (0.29 + or - 0.02 ppm/kbar) and BaF2 (0.62 + or - 0.05 ppm/kbar). Results at ambient temperature and pressure are also reported for a number of other fluorine compounds. Because of its high data rate, this technique is potentially several orders of magnitude more sensitive than similar CW methods.

  10. Correlated edge overlaps in multiplex networks

    NASA Astrophysics Data System (ADS)

    Baxter, Gareth J.; Bianconi, Ginestra; da Costa, Rui A.; Dorogovtsev, Sergey N.; Mendes, José F. F.

    2016-07-01

    We develop the theory of sparse multiplex networks with partially overlapping links based on their local treelikeness. This theory enables us to find the giant mutually connected component in a two-layer multiplex network with arbitrary correlations between connections of different types. We find that correlations between the overlapping and nonoverlapping links markedly change the phase diagram of the system, leading to multiple hybrid phase transitions. For assortative correlations we observe recurrent hybrid phase transitions.

  11. Formation of laser-induced periodic surface structures on fused silica upon multiple cross-polarized double-femtosecond-laser-pulse irradiation sequences

    SciTech Connect

    Rohloff, M.; Das, S. K.; Hoehm, S.; Grunwald, R.; Rosenfeld, A.; Krueger, J.; Bonse, J.

    2011-07-01

    The formation of laser-induced periodic surface structures (LIPSS) upon irradiation of fused silica with multiple irradiation sequences consisting of five Ti:sapphire femtosecond (fs) laser pulse pairs (150 fs, 800 nm) is studied experimentally. A Michelson interferometer is used to generate near-equal-energy double-pulse sequences with a temporal pulse delay from -20 to +20 ps between the cross-polarized individual fs-laser pulses ({approx}0.2 ps resolution). The results of multiple double-pulse irradiation sequences are characterized by means of Scanning Electron and Scanning Force Microscopy. Specifically in the sub-ps delay domain striking differences in the surface morphologies can be observed, indicating the importance of the laser-induced free-electron plasma in the conduction band of the solids for the formation of LIPSS.

  12. Non-invasive measurement of the blood pressure pulse using multiple PPGs

    NASA Astrophysics Data System (ADS)

    Seymour, John; Pennington, Gary

    Heart disease, the leading cause of death in the US, may be spotted early on by looking at photoplethysmogram (PPG) data. This experiment explores a new method of continuously monitoring the blood pressure pulse with PPG data. In contrast to the traditional sphygmomanometer (cuff) method, which yields only the systolic and diastolic pressure during measurement, this method tracks the blood pressure pulse wave in a non-invasive continuous manner. This procedure allows for fast, inexpensive, and detailed analysis of the patient's blood pressure implementable on a large scale. We also explore the second derivative of the PPG data. In combination with the above method, the patient's heart risk can be effectively detected. We acknowledge Fisher Endowment Grant support from the Jess and Mildred Fisher College of Science and Mathematics, Towson University.

  13. Multiple platform application of 3D CAD PIC simulations in pulsed power

    SciTech Connect

    Peratt, A.L.; Mostrom, M.A.

    1995-12-31

    With the availability of 80--125 MHz microprocessors, the methodology developed for the simulation of problems in pulsed power and plasma physics on modern day supercomputers is now amenable to application on a wide range of platforms including laptops and workstations. While execution speeds with these processors do not match those of large scale computing machines, resources such as computer-aided-design (CAD) and graphical analysis codes are available to automate simulation setup and process data. This paper reports on the adaptation of IVORY, a three-dimensional, fully-electromagnetic, particle-in-cell simulation code, to this platform independent CAD environment. The primary purpose of this talk is to demonstrate how rapidly a pulsed power/plasma problem can be scoped out by an experimenter on a dedicated workstation. Demonstrations include a magnetically insulated transmission line, power flow in a graded insulator stack, a relativistic klystron oscillator, and the dynamics of a coaxial thruster for space applications.

  14. Duration of an intense laser pulse can determine the breakage of multiple chemical bonds.

    PubMed

    Xie, Xinhua; Lötstedt, Erik; Roither, Stefan; Schöffler, Markus; Kartashov, Daniil; Midorikawa, Katsumi; Baltuška, Andrius; Yamanouchi, Kaoru; Kitzler, Markus

    2015-08-14

    Control over the breakage of a certain chemical bond in a molecule by an ultrashort laser pulse has been considered for decades. With the availability of intense non-resonant laser fields it became possible to pre-determine femtosecond to picosecond molecular bond breakage dynamics by controlled distortions of the electronic molecular system on sub-femtosecond time scales using field-sensitive processes such as strong-field ionization or excitation. So far, all successful demonstrations in this area considered only fragmentation reactions, where only one bond is broken and the molecule is split into merely two moieties. Here, using ethylene (C2H4) as an example, we experimentally investigate whether complex fragmentation reactions that involve the breakage of more than one chemical bond can be influenced by parameters of an ultrashort intense laser pulse. We show that the dynamics of removing three electrons by strong-field ionization determines the ratio of fragmentation of the molecular trication into two respectively three moieties. We observe a relative increase of two-body fragmentations with the laser pulse duration by almost an order of magnitude. Supported by quantum chemical simulations we explain our experimental results by the interplay between the dynamics of electron removal and nuclear motion.

  15. Influence of the cumulative effects of multiple laser pulses on laser-induced incandescence signals from soot

    NASA Astrophysics Data System (ADS)

    De Iuliis, S.; Cignoli, F.; Maffi, S.; Zizak, G.

    2011-08-01

    The effect of multiple laser pulses reaching soot particles before an actual laser-induced incandescence (LII) measurement is investigated in order to gain some insights on soot morphological and fine structure changes due to rapid laser heating. Soot, extracted from a premixed and a quenched diffusion flames, is flowing through a tubular cell and undergoes a variable number of pulses at different fluence. The response of soot is studied by the two-color LII technique. Transmission electron microscopy (TEM) analysis of laser-modified soot aggregates from the diffusion flame is also presented. The results indicate that even at low laser fluences a permanent soot transformation is induced causing an increase in the absorption function E( m). This is interpreted as an induced graphitization of soot particles by the laser pulse heating. At high fluences the vaporization process and a profound restructuring of soot particles affect the morphology of the aggregates. Soot from diffusion and premixed flames behaves in a similar way although this similarity occurs at different fluence levels indicating a different initial fine structure of soot particles.

  16. Storage of multiple single-photon pulses emitted from a quantum dot in a solid-state quantum memory

    PubMed Central

    Tang, Jian-Shun; Zhou, Zong-Quan; Wang, Yi-Tao; Li, Yu-Long; Liu, Xiao; Hua, Yi-Lin; Zou, Yang; Wang, Shuang; He, De-Yong; Chen, Geng; Sun, Yong-Nan; Yu, Ying; Li, Mi-Feng; Zha, Guo-Wei; Ni, Hai-Qiao; Niu, Zhi-Chuan; Li, Chuan-Feng; Guo, Guang-Can

    2015-01-01

    Quantum repeaters are critical components for distributing entanglement over long distances in presence of unavoidable optical losses during transmission. Stimulated by the Duan–Lukin–Cirac–Zoller protocol, many improved quantum repeater protocols based on quantum memories have been proposed, which commonly focus on the entanglement-distribution rate. Among these protocols, the elimination of multiple photons (or multiple photon-pairs) and the use of multimode quantum memory are demonstrated to have the ability to greatly improve the entanglement-distribution rate. Here, we demonstrate the storage of deterministic single photons emitted from a quantum dot in a polarization-maintaining solid-state quantum memory; in addition, multi-temporal-mode memory with 1, 20 and 100 narrow single-photon pulses is also demonstrated. Multi-photons are eliminated, and only one photon at most is contained in each pulse. Moreover, the solid-state properties of both sub-systems make this configuration more stable and easier to be scalable. Our work will be helpful in the construction of efficient quantum repeaters based on all-solid-state devices. PMID:26468996

  17. Storage of multiple single-photon pulses emitted from a quantum dot in a solid-state quantum memory.

    PubMed

    Tang, Jian-Shun; Zhou, Zong-Quan; Wang, Yi-Tao; Li, Yu-Long; Liu, Xiao; Hua, Yi-Lin; Zou, Yang; Wang, Shuang; He, De-Yong; Chen, Geng; Sun, Yong-Nan; Yu, Ying; Li, Mi-Feng; Zha, Guo-Wei; Ni, Hai-Qiao; Niu, Zhi-Chuan; Li, Chuan-Feng; Guo, Guang-Can

    2015-10-15

    Quantum repeaters are critical components for distributing entanglement over long distances in presence of unavoidable optical losses during transmission. Stimulated by the Duan-Lukin-Cirac-Zoller protocol, many improved quantum repeater protocols based on quantum memories have been proposed, which commonly focus on the entanglement-distribution rate. Among these protocols, the elimination of multiple photons (or multiple photon-pairs) and the use of multimode quantum memory are demonstrated to have the ability to greatly improve the entanglement-distribution rate. Here, we demonstrate the storage of deterministic single photons emitted from a quantum dot in a polarization-maintaining solid-state quantum memory; in addition, multi-temporal-mode memory with 1, 20 and 100 narrow single-photon pulses is also demonstrated. Multi-photons are eliminated, and only one photon at most is contained in each pulse. Moreover, the solid-state properties of both sub-systems make this configuration more stable and easier to be scalable. Our work will be helpful in the construction of efficient quantum repeaters based on all-solid-state devices.

  18. Multiple Ionization of Free Ubiquitin Molecular Ions in Extreme Ultraviolet Free-Electron Laser Pulses.

    PubMed

    Schlathölter, Thomas; Reitsma, Geert; Egorov, Dmitrii; Gonzalez-Magaña, Olmo; Bari, Sadia; Boschman, Leon; Bodewits, Erwin; Schnorr, Kirsten; Schmid, Georg; Schröter, Claus Dieter; Moshammer, Robert; Hoekstra, Ronnie

    2016-08-26

    The fragmentation of free tenfold protonated ubiquitin in intense 70 femtosecond pulses of 90 eV photons from the FLASH facility was investigated. Mass spectrometric investigation of the fragment cations produced after removal of many electrons revealed fragmentation predominantly into immonium ions and related ions, with yields increasing linearly with intensity. Ionization clearly triggers a localized molecular response that occurs before the excitation energy equilibrates. Consistent with this interpretation, the effect is almost unaffected by the charge state, as fragmentation of sixfold deprotonated ubiquitin leads to a very similar fragmentation pattern. Ubiquitin responds to EUV multiphoton ionization as an ensemble of small peptides. PMID:27453360

  19. Overlap among Environmental Databases.

    ERIC Educational Resources Information Center

    Miller, Betty

    1981-01-01

    Describes the methodology and results of a study comparing the overlap of Enviroline, Pollution, and the Environmental Periodicals Bibliography files through searches on acid rain, asbestos and water, diesel, glass recycling, Lake Erie, Concorde, reverse osmosis wastewater treatment cost, and Calspan. Nine tables are provided. (RBF)

  20. Design of pulse waveform for waveform division multiple access UWB wireless communication system.

    PubMed

    Yin, Zhendong; Wang, Zhirui; Liu, Xiaohui; Wu, Zhilu

    2014-01-01

    A new multiple access scheme, Waveform Division Multiple Access (WDMA) based on the orthogonal wavelet function, is presented. After studying the correlation properties of different categories of single wavelet functions, the one with the best correlation property will be chosen as the foundation for combined waveform. In the communication system, each user is assigned to different combined orthogonal waveform. Demonstrated by simulation, combined waveform is more suitable than single wavelet function to be a communication medium in WDMA system. Due to the excellent orthogonality, the bit error rate (BER) of multiuser with combined waveforms is so close to that of single user in a synchronous system. That is to say, the multiple access interference (MAI) is almost eliminated. Furthermore, even in an asynchronous system without multiuser detection after matched filters, the result is still pretty ideal and satisfactory by using the third combination mode that will be mentioned in the study.

  1. Multiple & Overlapping Identities: The Case of Guam

    ERIC Educational Resources Information Center

    Misco, Thomas; Lee, Lena

    2012-01-01

    Schools in Guam function to Americanize immigrants by adjusting different sociocultural values to American mainstream beliefs and practices which are considered norms, such as the matters of hygiene, manners, and farming and food preparation process. However, the educators in this study manifested their different ways of understanding and an…

  2. Transistorized Marx bank pulse circuit provides voltage multiplication with nanosecond rise-time

    NASA Technical Reports Server (NTRS)

    Jung, E. A.; Lewis, R. N.

    1968-01-01

    Base-triggered avalanche transistor circuit used in a Marx bank pulser configuration provides voltage multiplication with nanosecond rise-time. The avalanche-mode transistors replace conventional spark gaps in the Marx bank. The delay time from an input signal to the output signal to the output is typically 6 nanoseconds.

  3. Gamma-ray pulse height spectrum analysis on systems with multiple Ge detectors using a spectrum summing

    SciTech Connect

    Killian, E.W.

    1997-05-01

    A technique has been developed at the Idaho National Engineering Laboratory to sum high resolution gamma-ray pulse spectra from systems with multiple Ge detectors. Lockheed Martin Idaho Technologies Company operates a multi-detector spectrometer configuration at the Stored Waste Examination Pilot Plant facility which is used to characterize the radio nuclide contents in waste drums destined for shipment to Waste Isolation Pilot Plant. This summing technique was developed to increase the sensitivity of the system, reduce the count times required to properly quantify the radionuclides and provide a more consistent methodology for combining data collected from multiple detectors. In spectrometer systems with multiple detectors looking at non homogenous waste forms it is often difficult to combine individual spectrum analysis results from each detector to obtain a meaningful result for the total waste container. This is particularly true when the counting statistics in each individual spectrum are poor. The spectrum summing technique adds the spectra collected by each detector into a single spectrum which has better counting statistics than each individual spectrum. A normal spectral analysis program can then be used to analyze the sum spectrum to obtain radio nuclide values which have smaller errors and do not have to be further manipulated to obtain results for the total waste container.

  4. Multiple Scattering of Laser Pulses in Snow Over Ice: Modeling the Potential Bias in ICESat Altimetry

    NASA Technical Reports Server (NTRS)

    Davis, A. B.; Varnai, T.; Marshak, A.

    2010-01-01

    The primary goal of NASA's current ICESat and future ICESat2 missions is to map the altitude of the Earth's land ice with high accuracy using laser altimetry technology, and to measure sea ice freeboard. Ice however is a highly transparent optical medium with variable scattering and absorption properties. Moreover, it is often covered by a layer of snow with varying depth and optical properties largely dependent on its age. We describe a modeling framework for estimating the potential altimetry bias caused by multiple scattering in the layered medium. We use both a Monte Carlo technique and an analytical diffusion model valid for optically thick media. Our preliminary numerical results are consistent with estimates of the multiple scattering delay from laboratory measurements using snow harvested in Greenland, namely, a few cm. Planned refinements of the models are described.

  5. HUNTing the Overlap

    SciTech Connect

    Iancu, Costin; Parry, Husbands; Hargrove, Paul

    2005-07-08

    Hiding communication latency is an important optimization for parallel programs. Programmers or compilers achieve this by using non-blocking communication primitives and overlapping communication with computation or other communication operations. Using non-blocking communication raises two issues: performance and programmability. In terms of performance, optimizers need to find a good communication schedule and are sometimes constrained by lack of full application knowledge. In terms of programmability, efficiently managing non-blocking communication can prove cumbersome for complex applications. In this paper we present the design principles of HUNT, a runtime system designed to search and exploit some of the available overlap present at execution time in UPC programs. Using virtual memory support, our runtime implements demand-driven synchronization for data involved in communication operations. It also employs message decomposition and scheduling heuristics to transparently improve the non-blocking behavior of applications. We provide a user level implementation of HUNT on a variety of modern high performance computing systems. Results indicate that our approach is successful in finding some of the overlap available at execution time. While system and application characteristics influence performance, perhaps the determining factor is the time taken by the CPU to execute a signal handler. Demand driven synchronization at execution time eliminates the need for the explicit management of non-blocking communication. Besides increasing programmer productivity, this feature also simplifies compiler analysis for communication optimizations.

  6. Modeling the effect of native and laser-induced states on the dielectric breakdown of wide band gap optical materials by multiple subpicosecond laser pulses

    SciTech Connect

    Emmert, Luke A.; Mero, Mark; Rudolph, Wolfgang

    2010-08-15

    A model for the multiple-pulse laser-induced breakdown behavior of dielectrics is presented. It is based on a critical conduction band (CB) electron density leading to dielectric breakdown. The evolution of the CB electron density during the pulse train is calculated using rate equations involving transitions between band and mid-gap states (native and laser-induced). Using realistic estimations for the trap density and ionization cross-section, the model is able to reproduce the experimentally observed drop in the multiple-pulse damage threshold relative to the single-pulse value, as long as the CB electron density is controlled primarily by avalanche ionization seeded by multiphoton ionization of the traps and the valence band. The model shows that at long pulse duration, the breakdown threshold becomes more sensitive to presence of traps close (within one photon energy) to the CB. The effect of native and laser-induced defects can be distinguished by their saturation behavior. Finally, measurements of the multiple-pulse damage threshold of hafnium oxide films are used to illustrate the application of the model.

  7. Multiple scavengers respond rapidly to pulsed carrion resources at the land-ocean interface

    NASA Astrophysics Data System (ADS)

    Schlacher, Thomas A.; Strydom, Simone; Connolly, Rod M.

    2013-04-01

    Sandy beaches are the globe's longest interface region between the oceans and the continents, forming highly permeable boundaries across which matter flows readily. Stranded marine carrion supplies a high-quality food source to scavengers, but the role of animal carcasses is generally under-reported in sandy-beach food webs. We examined the response of scavengers to pulsed subsidies in the form of experimental additions of fish carcasses to the dune-beach interface in eastern Australia. Ghost crabs (Ocypode spp.) are the dominant invertebrate scavengers in these habitats and they responded strongly and consistently to changed resource availability: densities increased significantly within days of carrion augmentations. Carcasses added experimentally also formed local nuclei for a diversity of vertebrate scavengers that aggregated at food falls; these included large lizards, several species of birds (including raptors), and foxes. Consumption of fish carrion by the vertebrate scavengers was rapid and often complete. There is also evidence for higher-order interactions, where responses of invertebrate scavengers became depressed in plots where vertebrate scavenger activity was intense. Our findings emphasize that carrion can be a pivotal component of beach food webs.

  8. Direct spectroscopic observation of multiple-charged-ion acceleration by an intense femtosecond-pulse laser.

    PubMed

    Zhidkov, A G; Sasaki, A; Tajima, T; Auguste, T; D'Olivera, P; Hulin, S; Monot, P; Faenov, A Y; Pikuz, T A; Skobelev, I Y

    1999-09-01

    We have observed evidence of the emission of energetic He-and H-like ions of fluorine more than 1 MeV produced via the optical field ionization (OFI) from a solid target irradiated by an intense I=(2-4)x10(18) W/cm(2) (60 fs, lambda=800 nm), obliquely incident p-polarized pulse laser. The measured blue wing of He(alpha), He(beta), and Ly(alpha) lines of fluorine shows a feature of the Doppler-shifted spectrum due to the self-similar ion expansion dominated by superthermal electrons with the temperature T(h) approximately 100 keV. Using a collisional particle-in-cell simulation, which incorporates the nonlocal-thermodynamic-equilibrium ionization including OFI, we have obtained the plasma temperature, line shape, and maximal energy of accelerated ions, which agree well with those determined from the experimental spectra. The red wing of ion spectra gives the temperature of bulk plasma electrons.

  9. Petrogenesis of the Elephant Moraine A79001 meteorite Multiple magma pulses on the shergottite parent body

    NASA Technical Reports Server (NTRS)

    Mcsween, H. Y., Jr.; Jarosewich, E.

    1983-01-01

    The EETA 79001 achondrite consists of two distinct igneous lithologies joined along a planar, non-brecciated contact. Both are basaltic rocks composed primarily of pigeonite, augite, and maskelynite, but one contains zoned megacrysts of olivine, orthopyroxene, and chromite that represent disaggregated xenoliths of harzburzite. Both lithologies probably formed from successive volcanic flows or multiple injections of magma into a small, shallow chamber. Many similarities between the two virtually synchronous magmas suggest that they are related. Possible mechanisms to explain their differences involve varying degrees of assimilation, fractionation from similar parental magmas, or partial melting of a similar source peridotite; of these, assimilation of the observed megacryst assemblage seems most plausible. However, some isotopic contamination may be required in any of these petrogenetic models. The meteorite has suffered extensive shock metamorphism and localized melting during a large impact event that probably excavated and liberated it from its parent body.

  10. Photonic reagents for concentration measurement of flu-orescent proteins with overlapping spectra

    NASA Astrophysics Data System (ADS)

    Goun, Alexei; Bondar, Denys I.; Er, Ali O.; Quine, Zachary; Rabitz, Herschel A.

    2016-05-01

    By exploiting photonic reagents (i.e., coherent control by shaped laser pulses), we employ Optimal Dynamic Discrimination (ODD) as a novel means for quantitatively characterizing mixtures of fluorescent proteins with a large spectral overlap. To illustrate ODD, we simultaneously measured concentrations of in vitro mixtures of Enhanced Blue Fluorescent Protein (EBFP) and Enhanced Cyan Fluorescent Protein (ECFP). Building on this foundational study, the ultimate goal is to exploit the capabilities of ODD for parallel monitoring of genetic and protein circuits by suppressing the spectral cross-talk among multiple fluorescent reporters.

  11. Photonic reagents for concentration measurement of flu-orescent proteins with overlapping spectra

    PubMed Central

    Goun, Alexei; Bondar, Denys I.; Er, Ali O.; Quine, Zachary; Rabitz, Herschel A.

    2016-01-01

    By exploiting photonic reagents (i.e., coherent control by shaped laser pulses), we employ Optimal Dynamic Discrimination (ODD) as a novel means for quantitatively characterizing mixtures of fluorescent proteins with a large spectral overlap. To illustrate ODD, we simultaneously measured concentrations of in vitro mixtures of Enhanced Blue Fluorescent Protein (EBFP) and Enhanced Cyan Fluorescent Protein (ECFP). Building on this foundational study, the ultimate goal is to exploit the capabilities of ODD for parallel monitoring of genetic and protein circuits by suppressing the spectral cross-talk among multiple fluorescent reporters. PMID:27181496

  12. Significantly improved luminescence properties of nitrogen-polar (0001̅) InGaN multiple quantum wells grown by pulsed metalorganic chemical vapor deposition.

    PubMed

    Song, Jie; Chang, Shih-Pang; Zhang, Cheng; Hsu, Ta-Cheng; Han, Jung

    2015-01-14

    We have demonstrated nitrogen-polar (0001̅) (N-polar) InGaN multiple quantum wells (MQWs) with significantly improved luminescence properties prepared by pulsed metalorganic chemical vapor deposition. During the growth of InGaN quantum wells, Ga and N sources are alternately injected into the reactor to alter the surface stoichiometry. The influence of flow duration in pulsed growth mode on the luminescence properties has been studied. We find that use of pulsed-mode creates a high density of hexagonal mounds with an increased InGaN growth rate and enhanced In composition around screw-type dislocations, resulting in remarkably improved luminescence properties. The mechanism of enhanced luminescence caused by the hexagonal mounds is discussed. Luminescence properties of N-polar InGaN MQWs grown with short pulse durations have been significantly improved in comparison with a sample grown by a conventional continuous growth method.

  13. Analysis of the Autographa californica Multiple Nucleopolyhedrovirus Overlapping Gene Pair lef3 and ac68 Reveals that AC68 Is a Per Os Infectivity Factor and that LEF3 Is Critical, but Not Essential, for Virus Replication

    PubMed Central

    Nie, Yingchao; Fang, Minggang; Erlandson, Martin A.

    2012-01-01

    Autographa californica multiple nucleopolyhedrovirus ac68 is a core gene that overlaps lef3 which encodes the single-stranded DNA binding protein. A knockout (KO) virus lacking both lef3 and ac68 was generated (lef3-ac68 2×KO) to enable the functional study of ac68. To produce an ac68KO virus that did not impact lef3 expression, the lef3-ac68 2×KO virus was repaired with a DNA fragment containing lef3 and ac68, in which ac68 contained point mutations so that only LEF3 was expressed. Repair of lef3-ac68 2×KO with just ac68 generated an lef3KO virus. Analysis of the ac68KO virus showed that viral DNA replication and budded virus (BV) levels were unaffected compared to levels in the double-repair or wild-type (WT) control virus. Bioassay analyses of Trichoplusia ni larvae injected with BV directly into the hemolymph, bypassing the gut, showed no difference in mortality rates between the ac68KO and the WT viruses. However, in oral bioassays the ac68KO occlusion bodies failed to kill larvae. These results show that the core gene ac68 encodes a per os infectivity factor (pif6). The lef3KO virus was also analyzed, and virus replication was drastically reduced compared to WT virus, but very low levels of lef3KO virus DNA replication and BV production could be detected. In addition, in transfected cells P143 was transported to the nucleus in the absence of LEF3. This study therefore shows for the first time that even though the loss of LEF3 severely impairs virus replication, it is not absolutely essential for P143 nuclear import or viral replication. PMID:22278232

  14. Overlap extension PCR cloning.

    PubMed

    Bryksin, Anton; Matsumura, Ichiro

    2013-01-01

    Rising demand for recombinant proteins has motivated the development of efficient and reliable cloning methods. Here we show how a beginner can clone virtually any DNA insert into a plasmid of choice without the use of restriction endonucleases or T4 DNA ligase. Chimeric primers encoding plasmid sequence at the 5' ends and insert sequence at the 3' ends are designed and synthesized. Phusion(®) DNA polymerase is utilized to amplify the desired insert by PCR. The double-stranded product is subsequently employed as a pair of mega-primers in a PCR-like reaction with circular plasmids. The original plasmids are then destroyed in restriction digests with Dpn I. The product of the overlap extension PCR is used to transform competent Escherichia coli cells. Phusion(®) DNA polymerase is used for both the amplification and fusion reactions, so both steps can be monitored and optimized in the same way. PMID:23996437

  15. Influence of driving frequency on discharge modes in a dielectric-barrier discharge with multiple current pulses

    SciTech Connect

    Jiang, Weiman; Tang, Jie; Wang, Yishan; Zhao, Wei; Duan, Yixiang

    2013-07-15

    A one-dimensional self-consistent fluid model was employed to investigate the effect of the driving frequency on the discharge modes in atmospheric-pressure argon discharge with multiple current pulses. The discharge mode was discussed in detail not only at current peaks but also between two adjacent peaks. The simulation results show that different transitions between the Townsend and glow modes during the discharge take place with the driving frequency increased. A complicated transition from the Townsend mode, through glow, Townsend, and glow, and finally back to the Townsend one is found in the discharge with the driving frequency of 8 kHz. There is a tendency of transition from the Townsend to glow mode for the discharge both at the current peaks and troughs with the increasing frequency. The discharge in the half period can all along operate in the glow mode with the driving frequency high enough. This is resulted from the preservation of more electrons in the gas gap and acquisition of more electron energy from the swiftly varying electric field with the increase in driving frequency. Comparison of the spatial and temporal evolutions of the electron density at different driving frequencies indicates that the increment of the driving frequency allows the plasma chemistry to be enhanced. This electrical characteristic is important for the applications, such as surface treatment and biomedical sterilization.

  16. Subsurface modifications in indium phosphide induced by single and multiple femtosecond laser pulses: A study on the formation of periodic ripples

    SciTech Connect

    Couillard, M.; Borowiec, A.; Haugen, H. K.; Preston, J. S.; Griswold, E. M.; Botton, G. A.

    2007-02-01

    We use cross-sectional transmission electron microscopy to study the damage induced below the surface of indium phosphide (InP) samples by single and multiple femtosecond laser pulses with a photon energy lower than the InP band gap. Single-pulse irradiation creates a {approx}100 nm deep crater with a resolidified surface layer consisting of quasiamorphous indium phosphide. The resolidified layer has a thickness of {approx}60 nm at the center and extends laterally beyond the edge of the crater rim. Exposure to multiple femtosecond pulses of 2050 nm center wavelength results in the formation of laser-induced periodic surface structures (LIPSS) with two different periods, one ({approx}1730 nm) less than but close to the laser wavelength and one ({approx}470 nm) four times smaller. Segregation beneath both types of ripples leads to the formation of In-rich particles embedded in the resolidified surface layer. Extended defects are detected only below the center of the multiple-pulse crater and their distribution appears to be correlated with the LIPSS modulation. Finally, LIPSS formation is discussed in terms of the observed subsurface microstructures.

  17. Overlapping left ventricular restoration.

    PubMed

    Matsui, Yoshiro

    2009-06-01

    Cardiac transplantation, a final option of treatment for refractory heart failure, has not been a standard procedure in Japan especially, mainly because of the shortage of donors. However, surgical methods to restore native heart function, such as surgical ventricular restoration (SVR), are often effective for these cases. The Dor procedure has been used for ischemic cardiomyopathy cases presenting with broad akinetic segments. This is a fine method to exclude the scarred septum and to reduce the intraventricular cavity by encircling purse-string suture, but it may produce a postoperative spherical ventricular shape as a result of endoventricular patch repair. Also, partial left ventriculectomy is not recommended for non-ischemic dilated cardiomyopathy cases for now. A modification of these SVR and surgical approaches to functional mitral regurgitation has been named "overlapping ventriculoplasty" without endoventricular patch and resection of viable cardiac muscle, and "mitral complex reconstruction", which consists of mitral annuloplasty, papillary muscle approximation, and suspension. Although the long-term prognosis of these procedures is undetermined, they could be an important option, at least as an alternative bridge to transplantation. This review will describe the concepts and some technical aspects of these procedures for the end-stage heart. PMID:19474505

  18. Overcoming the overlap problem in the assignment of 1H NMR spectra of larger proteins by use of three-dimensional heteronuclear 1H-15N Hartmann-Hahn-multiple quantum coherence and nuclear Overhauser-multiple quantum coherence spectroscopy: application to interleukin 1 beta.

    PubMed

    Marion, D; Driscoll, P C; Kay, L E; Wingfield, P T; Bax, A; Gronenborn, A M; Clore, G M

    1989-07-25

    The application of three-dimensional (3D) heteronuclear NMR spectroscopy to the sequential assignment of the 1H NMR spectra of larger proteins is presented, using uniformly labeled (approximately 95%) [15N]interleukin 1 beta, a protein of 153 residues and molecular mass of 17.4 kDa, as an example. The two-dimensional (2D) 600-MHz spectra of interleukin 1 beta are too complex for complete analysis, owing to extensive cross-peak overlap and chemical shift degeneracy. We show that the combined use of 3D 1H-15N Hartmann-Hahn-multiple quantum coherence (HOHAHA-HMQC) and nuclear Overhauser-multiple quantum coherence (NOESY-HMQC) spectroscopy, designed to provide the necessary through-bond and through-space correlations for sequential assignment, provides a practical general-purpose method for resolving ambiguities which severely limit the analysis of conventional 2D NMR spectra. The absence of overlapping cross-peaks in these 3D spectra allows the unambiguous identification of C alpha H(i)-NH(i+1) and NH(i)-NH(i+1) through-space nuclear Overhauser connectivities necessary for connecting a particular C alpha H(i)-NH(i) through-bond correlation with its associated through-space sequential cross-peak The problem of amide NH chemical shift degeneracy in the 1H NMR spectrum is therefore effectively removed, and the assignment procedure simply involves inspecting a series of 2D 1H-1H slices edited by the chemical shift of the directly bonded 15N atom. Connections between residues can be identified almost without any knowledge of the spin system types involved, though this type of information is clearly required for the eventual placement of the connected residues within the primary sequence.

  19. Transcranial pulsed electromagnetic fields for multiple chemical sensitivity: study protocol for a randomized, double-blind, placebo-controlled trial

    PubMed Central

    2013-01-01

    Background Multiple chemical sensitivity (MCS) is a chronic condition of unknown etiology. MCS is characterized by recurrent nonspecific symptoms from multiple organ systems in response to chemical exposures in concentrations that are normally tolerated by the majority of the population. The symptoms may have severe impact on patients’ lives, but an evidence-based treatment for the condition is nonexisting. The pathophysiology is unclarified, but several indicators point towards abnormal processing of sensory signals in the central nervous system. Pulsed electromagnetic fields (PEMF) offer a promising new treatment for refractory depression and can be targeted at the brain, thereby activating biochemical cell processes. Methods/Design In a parallel, randomized, double-blind, placebo-controlled trial conducted at the Danish Research Centre for Chemical Sensitivities, the effects of PEMF in MCS patients will be assessed using the Re5 Independent System. Based on sample size estimation, 40 participants will be randomized to either PEMF therapy or placebo. The allocation sequence will be generated by computer. All involved parties (that is, participants, investigators, the research nurse, and the statistician) will be blinded to group allocation. The participants will receive PEMF therapy or placebo applied transcranially 30 minutes twice a day for 7 days a week over 6 consecutive weeks. Outcomes will be measured at baseline, once weekly during treatment, post treatment, and at 2.5-month and 4.5-month follow-up according to a predefined timetable. The primary outcome will be a measurement of the impact of MCS on everyday life. The secondary outcomes will be measurements of MCS symptoms, psychological distress (stress, anxiety or depressive symptoms), capsaicin-induced secondary punctate hyperalgesia, immunological markers in serum, and quality of life. Discussion This trial will assess the effects of PEMF therapy for MCS. Currently, there is no treatment with a

  20. Multiple Employment Training Programs. Overlap among Programs Raises Questions about Efficiency. Report to the Chairman, Subcommittee on Labor, Health and Human Services and Education, Committee on Appropriations, U.S. Senate.

    ERIC Educational Resources Information Center

    General Accounting Office, Washington, DC. Health, Education, and Human Services Div.

    A study examined the types and extent of overlap among federal employment and training (E&T) programs targeting economically disadvantaged persons, dislocated workers, older workers, and youth. Of 38 programs analyzed, 30 shared common goals, had comparable clients, provided similar services, and used parallel delivery mechanisms and…

  1. Overlapping clusters for distributed computation.

    SciTech Connect

    Mirrokni, Vahab; Andersen, Reid; Gleich, David F.

    2010-11-01

    Scalable, distributed algorithms must address communication problems. We investigate overlapping clusters, or vertex partitions that intersect, for graph computations. This setup stores more of the graph than required but then affords the ease of implementation of vertex partitioned algorithms. Our hope is that this technique allows us to reduce communication in a computation on a distributed graph. The motivation above draws on recent work in communication avoiding algorithms. Mohiyuddin et al. (SC09) design a matrix-powers kernel that gives rise to an overlapping partition. Fritzsche et al. (CSC2009) develop an overlapping clustering for a Schwarz method. Both techniques extend an initial partitioning with overlap. Our procedure generates overlap directly. Indeed, Schwarz methods are commonly used to capitalize on overlap. Elsewhere, overlapping communities (Ahn et al, Nature 2009; Mishra et al. WAW2007) are now a popular model of structure in social networks. These have long been studied in statistics (Cole and Wishart, CompJ 1970). We present two types of results: (i) an estimated swapping probability {rho}{infinity}; and (ii) the communication volume of a parallel PageRank solution (link-following {alpha} = 0.85) using an additive Schwarz method. The volume ratio is the amount of extra storage for the overlap (2 means we store the graph twice). Below, as the ratio increases, the swapping probability and PageRank communication volume decreases.

  2. Rapid frequency control of sonar sounds by the FM bat, Miniopterus fuliginosus, in response to spectral overlap.

    PubMed

    Hase, Kazuma; Miyamoto, Takara; Kobayasi, Kohta I; Hiryu, Shizuko

    2016-07-01

    In the presence of multiple flying conspecifics, echolocating bats avoid jamming by adjusting the spectral and/or temporal features of their vocalizations. However, little is known about how bats alter their pulse acoustic characteristics to adapt to an acoustically jamming situation during flight. We investigated echolocation behavior in a bat (Miniopterus fuliginosus) during free flight under acoustic jamming conditions created by downward FM jamming sounds mimicking bat echolocation sounds. In an experimental chamber, the flying bat was exposed to FM jamming sounds with different terminal frequencies (TFs) from loudspeakers. Echolocation pulses emitted by the flying bat were recorded using a telemetry microphone (Telemike) mounted on the back of the bat. The bats immediately (within 150ms) shifted the TFs of emitted pulses upward when FM jamming sounds were presented. Moreover, the amount of upward TF shift differed depending on the TF ranges of the jamming sounds presented. When the TF range was lower than or overlapped the bat's mean TF, the bat TF shifted significantly upward (by 1-2kHz, Student's t-test, P<0.05), corresponding to 3-5% of the total bandwidth of their emitted pulses. These findings indicate that bats actively avoid overlap of the narrow frequency band around the TF. PMID:27157002

  3. Rapid frequency control of sonar sounds by the FM bat, Miniopterus fuliginosus, in response to spectral overlap.

    PubMed

    Hase, Kazuma; Miyamoto, Takara; Kobayasi, Kohta I; Hiryu, Shizuko

    2016-07-01

    In the presence of multiple flying conspecifics, echolocating bats avoid jamming by adjusting the spectral and/or temporal features of their vocalizations. However, little is known about how bats alter their pulse acoustic characteristics to adapt to an acoustically jamming situation during flight. We investigated echolocation behavior in a bat (Miniopterus fuliginosus) during free flight under acoustic jamming conditions created by downward FM jamming sounds mimicking bat echolocation sounds. In an experimental chamber, the flying bat was exposed to FM jamming sounds with different terminal frequencies (TFs) from loudspeakers. Echolocation pulses emitted by the flying bat were recorded using a telemetry microphone (Telemike) mounted on the back of the bat. The bats immediately (within 150ms) shifted the TFs of emitted pulses upward when FM jamming sounds were presented. Moreover, the amount of upward TF shift differed depending on the TF ranges of the jamming sounds presented. When the TF range was lower than or overlapped the bat's mean TF, the bat TF shifted significantly upward (by 1-2kHz, Student's t-test, P<0.05), corresponding to 3-5% of the total bandwidth of their emitted pulses. These findings indicate that bats actively avoid overlap of the narrow frequency band around the TF.

  4. A study of ablation, spatial, and temporal characteristics of laser-induced plasmas generated by multiple collinear pulses.

    PubMed

    Galbács, G; Jedlinszki, N; Herrera, K; Omenetto, N; Smith, B W; Winefordner, J D

    2010-02-01

    Multi-pulse laser-induced breakdown spectroscopy (LIBS) in the collinear pulse configuration with time-integrating detection was performed on metallic samples in ambient air in an effort to clarify the contributing processes responsible for the signal enhancement observed in comparison with single-pulse excitation. Complementary experiments were also carried out on another LIBS setup using detection by an imaging spectrograph with high time resolution. The effects of laser bursts consisting of up to seven ns-range pulses from Nd-doped solid-state lasers operating at their fundamental wavelength and separated by 8.5-50 micros time gaps was studied. The ablation and emission characteristics of the generated plasmas were investigated using light profilometry, microscopy, plasma imaging, emission distribution mapping, time-resolved line emission monitoring, and plasma temperature calculations. The experimental data suggest that the two contributing processes mainly responsible for the signal enhancement effect are the plume reheating caused by the sequential laser pulses and, more dominantly, the increased material ablation attributed to the lower breakdown threshold for the preheated (molten) sample surface and/or the reduced background gas pressure behind the shockwave of preceding pulses.

  5. Superposed pulse amplitude modulation for visible light communication.

    PubMed

    Li, J F; Huang, Z T; Zhang, R Q; Zeng, F X; Jiang, M; Ji, Y F

    2013-12-16

    We propose and experimentally demonstrate a novel modulation scheme called superposed pulse amplitude modulation (SPAM) which is low-cost, insensitive to non-linearity of light emitting diode (LED). Multiple optical pulses transmit parallelly from different spatial position in the LED array and overlap linearly in free space to realize SPAM. With LED arrangement, the experimental results show that using the modulation we proposed the data rate of 120 Mbit/s with BER 1 × 10(-3) can be achieved with an optical blue filter and RC post-equalization. PMID:24514674

  6. On the Neuberger overlap operator

    NASA Astrophysics Data System (ADS)

    Boriçi, Artan

    1999-04-01

    We compute Neuberger's overlap operator by the Lanczos algorithm applied to the Wilson-Dirac operator. Locality of the operator for quenched QCD data and its eigenvalue spectrum in an instanton background are studied.

  7. Automated nucleus and cytoplasm segmentation of overlapping cervical cells.

    PubMed

    Lu, Zhi; Carneiro, Gustavo; Bradley, Andrew P

    2013-01-01

    In this paper we describe an algorithm for accurately segmenting the individual cytoplasm and nuclei from a clump of overlapping cervical cells. Current methods cannot undertake such a complete segmentation due to the challenges involved in delineating cells with severe overlap and poor contrast. Our approach initially performs a scene segmentation to highlight both free-lying cells, cell clumps and their nuclei. Then cell segmentation is performed using a joint level set optimization on all detected nuclei and cytoplasm pairs. This optimisation is constrained by the length and area of each cell, a prior on cell shape, the amount of cell overlap and the expected gray values within the overlapping regions. We present quantitative nuclei detection and cell segmentation results on a database of synthetically overlapped cell images constructed from real images of free-lying cervical cells. We also perform a qualitative assessment of complete fields of view containing multiple cells and cell clumps.

  8. Formation of laser-induced periodic surface structures (LIPSS) on tool steel by multiple picosecond laser pulses of different polarizations

    NASA Astrophysics Data System (ADS)

    Gregorčič, Peter; Sedlaček, Marko; Podgornik, Bojan; Reif, Jürgen

    2016-11-01

    Laser-induced periodic surface structures (LIPSS) are produced on cold work tool steel by irradiation with a low number of picosecond laser pulses. As expected, the ripples, with a period of about 90% of the laser wavelength, are oriented perpendicular to the laser polarization. Subsequent irradiation with the polarization rotated by 45° or 90° results in a corresponding rotation of the ripples. This is visible already with the first pulse and becomes almost complete - erasing the previous orientation - after as few as three pulses. The phenomenon is not only observed for single-spot irradiation but also for writing long coherent traces. The experimental results strongly defy the role of surface plasmon-polaritons as the predominant key to LIPSS formation.

  9. Multiple One-Dimensional Search (MODS) algorithm for fast optimization of laser-matter interaction by phase-only fs-laser pulse shaping

    NASA Astrophysics Data System (ADS)

    Galvan-Sosa, M.; Portilla, J.; Hernandez-Rueda, J.; Siegel, J.; Moreno, L.; Solis, J.

    2014-09-01

    In this work, we have developed and implemented a powerful search strategy for optimization of nonlinear optical effects by means of femtosecond pulse shaping, based on topological concepts derived from quantum control theory. Our algorithm [Multiple One-Dimensional Search (MODS)] is based on deterministic optimization of a single solution rather than pseudo-random optimization of entire populations as done by commonly used evolutionary algorithms. We have tested MODS against a genetic algorithm in a nontrivial problem consisting in optimizing the Kerr gating signal (self-interaction) of a shaped laser pulse in a detuned Michelson interferometer configuration. The obtained results show that our search method (MODS) strongly outperforms the genetic algorithm in terms of both convergence speed and quality of the solution. These findings demonstrate the applicability of concepts of quantum control theory to nonlinear laser-matter interaction problems, even in the presence of significant experimental noise.

  10. Compositional and Microstructural Evolution of Olivine Under Multiple-Cycle Pulsed Laser Irradiation as Revealed by FIB/Field-Emission TEM

    NASA Technical Reports Server (NTRS)

    Christoffersen, R.; Loeffler, M. J.; Dukes, C. A.; Keller, L. P.; Baragiola, R. A.

    2016-01-01

    The use of pulsed laser irradiation to simulate the short duration, high-energy conditions characteristic of micrometeorite impacts is now an established approach in experimental space weathering studies. The laser generates both melt and vapor deposits that contain nanophase metallic Fe (npFe(sup 0)) grains with size distributions and optical properties similar to those in natural impact-generated melt and vapor deposits. There remains uncertainty, however, about how well lasers simulate the mechanical work and internal (thermal) energy partitioning that occurs in actual impacts. We are currently engaged in making a direct comparison between the products of laser irradiation and experimental/natural hypervelocity impacts. An initial step reported here is to use analytical SEM and TEM is to attain a better understanding of how the microstructure and composition of laser deposits evolve over multiple cycles of pulsed laser irradiation.

  11. Effects of multiple scattering and Anderson localization of photons in light pulse reflection from a 1D disordered medium with low concentration of impurities

    NASA Astrophysics Data System (ADS)

    Chernyak, V. Ya.; Grigorishin, K. I.; Ogievetsky, E. I.; Agranovich, V. M.

    1992-10-01

    The theory of light pulse reflection from a one-dimensional(1D) disordered scattering medium exemplifying application of the supersymmetry to the solid state physics is developed. It is shown that multiple scattering processes and localization effects lead to a peculiar trapping of light in the medium and, as a result, to a peculiar time evolution of the reflected beam intensity. An addition of guest molecules with a narrow absorption line at low concentrations suppresses the contribution of long trajectories of photons resonating with impurities and, consequently, leads to the appearance of a narrow dip in the spectral decomposition of the reflected light in the long-time asymptotic regime.

  12. Steady slip pulses on faults with rate- and state-dependent friction and multiple thermal weakening mechanisms

    NASA Astrophysics Data System (ADS)

    Viesca, R. C.; Garagash, D.

    2012-12-01

    We present solutions for steadily propagating slip pulses whose underlying frictional evolution is dependent on both the rate of slip and the evolution of a state parameter (of a slip-law type), with strong velocity-dependent weakening of friction at high slip rates (via flash heating of asperity contacts). Additional weakening occurs by reduction of the effective normal stress by thermal pressurization of pore fluid within a shear zone of fixed nominal thickness. Such strong dynamic weakening mechanisms allow for rupture of faults under levels of a shear stress much lower than a nominal static strength. For decreasing levels of background shear stress, slip pulses become the favored mode as a critical point is reached where crack-like rupture modes may be inadmissible (Zheng and Rice, BSSA 1998). For even further decreases in shear stress, slip pulses may arrest shortly after nucleation, and our interest in characterizing steady pulse solutions lies partially in this precarious transition. The relative effect of the two thermal weakening mechanisms is determined by the relative size of the slip scales over which the flash heating and thermal pressurization evolve (Dc and Lachenbruch's δ c, respectively). Laboratory measurements of Dc and estimates for δ c indicate that Dc ≤ δ c: i.e., at the tip, weakening occurs as a cascade, which may be partially represented by tip solutions that neglect healing (Garagash and Viesca, AGU FM 2011). Considering the trailing edge, as state evolution of the slip-law type does not provide frictional restrengthening at zero slip velocity, the slip pulse heals asymptotically with distance behind the rupture tip in the absence of thermal pressurization. A robust, effective pulse length can be established in this case by setting a threshold value of the slip velocity. Allowing for TP provides a mechanism for stationary restrengthening and relocking of the fault at the trailing edge (Garagash, JGR 2012). We find relations between

  13. A suite of pulse sequences based on multiple sequential acquisitions at one and two radiofrequency channels for solid-state magic-angle spinning NMR studies of proteins.

    PubMed

    Sharma, Kshama; Madhu, Perunthiruthy K; Mote, Kaustubh R

    2016-08-01

    One of the fundamental challenges in the application of solid-state NMR is its limited sensitivity, yet a majority of experiments do not make efficient use of the limited polarization available. The loss in polarization in a single acquisition experiment is mandated by the need to select out a single coherence pathway. In contrast, sequential acquisition strategies can encode more than one pathway in the same experiment or recover unused polarization to supplement a standard experiment. In this article, we present pulse sequences that implement sequential acquisition strategies on one and two radiofrequency channels with a combination of proton and carbon detection to record multiple experiments under magic-angle spinning. We show that complementary 2D experiments such as [Formula: see text] and [Formula: see text] or DARR and [Formula: see text], and 3D experiments such as [Formula: see text] and [Formula: see text], or [Formula: see text] and [Formula: see text]  can be combined in a single experiment to ensure time savings of at least 40 %. These experiments can be done under fast or slow-moderate magic-angle spinning frequencies aided by windowed [Formula: see text] acquisition and homonulcear decoupling. The pulse sequence suite is further expanded by including pathways that allow the recovery of residual polarization, the so-called 'afterglow' pathways, to encode a number of pulse sequences to aid in assignments and chemical-shift mapping. PMID:27364976

  14. A suite of pulse sequences based on multiple sequential acquisitions at one and two radiofrequency channels for solid-state magic-angle spinning NMR studies of proteins.

    PubMed

    Sharma, Kshama; Madhu, Perunthiruthy K; Mote, Kaustubh R

    2016-08-01

    One of the fundamental challenges in the application of solid-state NMR is its limited sensitivity, yet a majority of experiments do not make efficient use of the limited polarization available. The loss in polarization in a single acquisition experiment is mandated by the need to select out a single coherence pathway. In contrast, sequential acquisition strategies can encode more than one pathway in the same experiment or recover unused polarization to supplement a standard experiment. In this article, we present pulse sequences that implement sequential acquisition strategies on one and two radiofrequency channels with a combination of proton and carbon detection to record multiple experiments under magic-angle spinning. We show that complementary 2D experiments such as [Formula: see text] and [Formula: see text] or DARR and [Formula: see text], and 3D experiments such as [Formula: see text] and [Formula: see text], or [Formula: see text] and [Formula: see text]  can be combined in a single experiment to ensure time savings of at least 40 %. These experiments can be done under fast or slow-moderate magic-angle spinning frequencies aided by windowed [Formula: see text] acquisition and homonulcear decoupling. The pulse sequence suite is further expanded by including pathways that allow the recovery of residual polarization, the so-called 'afterglow' pathways, to encode a number of pulse sequences to aid in assignments and chemical-shift mapping.

  15. Poor ex vivo induction of T-cell responses to idiotype or tumor cell lysate-pulsed autologous dendritic cells in advanced pre-treated multiple myeloma.

    PubMed

    Garderet, Laurent; Mazurier, Christelle; Pellat-Deceunynck, Catherine; Karim, Abdul; Baudin, Bruno; Funck-Brentano, Christian; Bouchet, Sandrine; Geffroy, Alexandrine; Bataille, Régis; Gorin, Norbert-Claude; Lopez, Manuel

    2006-07-01

    This study evaluated the feasibility of using dendritic cells (DCs) to generate, ex vivo, anti-tumor cytotoxic T lymphocytes (CTL) in patients with stage III multiple myeloma (MM). Nucleated cells from eight patients who had received chemotherapy (three of whom had undergone autologous hemopoeitic stem cell transplantation) were collected by apheresis. Their monocytes were enriched using counter-current centrifugation, differentiated into DCs which were further co-cultured with autologous CD8 lymphocytes to induce CTL. The DCs were pulsed either with the idiotypic paraprotein (regarded as a tumor-specific antigen) or with autologous MM cell lysate before co-culture. Specific T-cell responses were measured in IFNgamma enzyme-linked immunospot and chromium release assays of autologous plasmocyte targets. A slight increase in IFNgamma secretion by T-cells was observed for two patients (DCs pulsed with idiotypic paraprotein for one, MM cell lysate for the other). No or weak specific lysis of plasmocyte targets was observed in the chromium release assays. In conclusion, the T-cell response to pulsed DCs was very weak or absent. There are clinical and technical reasons that could explain, in part, this lack of response.

  16. Long Term Effects of Multiple DBD Pulses on Thin Liquid Layers Over Tissue: Reactive Fluences and Electric Fields

    NASA Astrophysics Data System (ADS)

    Tian, Wei; Kushner, Mark J.

    2014-10-01

    Atmospheric dielectric barrier discharges (DBDs) are used in treatment of tissue, often covered by thin liquid layers. The reactivity reaching the tissue depends on the plasma dose, composition and acidification of the liquid, and the cumulative delivery of electric fields through the liquid. In this paper, we report on a computational investigation of the interaction of DBDs with a thin liquid layer covering tissue over many minutes. We used nonPDPSIM, a 2-d model in which Poisson's equation, the electron temperature equation, transport equations for charged and neutral species and radiation transport are solved in both the gas and liquid. The liquid layer, 100's μm thick, is water with dissolved gases [O2aq (aq is aqueous), CO2aq], metal ions (Feaq2+ , Feaq3+) , and organics (RHaq) . Hundreds of pulses at 100 Hz are computed, followed by minutes of afterglow. In the liquid, transient radicals (OHaq, Haq) are produced during the discharge pulse and are consumed during the interpulse period. Terminal species (H2O2aq, O3aq) accumulate and diffuse to the tissue. Ions are dominated by NO3-aq, O2-aq and H3Oaq+.Production of HNO3aq and HOONOaq is assisted by O2aq for the first pulses and then O3aq. Accumulating nitric acid lowers the pH. RHaq consumes most reactive oxygen species in the early plasma treatment leaving Raq. With longer exposure, RHaq can be consumed, enabling more ROS to reach the tissue. The cumulative exposure of electric fields to the tissue depends on the increasing conductivity of the liquid. Work supported by DOE Office of Fusion Energy Science and NSF.

  17. Accurate Estimation of Airborne Ultrasonic Time-of-Flight for Overlapping Echoes

    PubMed Central

    Sarabia, Esther G.; Llata, Jose R.; Robla, Sandra; Torre-Ferrero, Carlos; Oria, Juan P.

    2013-01-01

    In this work, an analysis of the transmission of ultrasonic signals generated by piezoelectric sensors for air applications is presented. Based on this analysis, an ultrasonic response model is obtained for its application to the recognition of objects and structured environments for navigation by autonomous mobile robots. This model enables the analysis of the ultrasonic response that is generated using a pair of sensors in transmitter-receiver configuration using the pulse-echo technique. This is very interesting for recognizing surfaces that simultaneously generate a multiple echo response. This model takes into account the effect of the radiation pattern, the resonant frequency of the sensor, the number of cycles of the excitation pulse, the dynamics of the sensor and the attenuation with distance in the medium. This model has been developed, programmed and verified through a battery of experimental tests. Using this model a new procedure for obtaining accurate time of flight is proposed. This new method is compared with traditional ones, such as threshold or correlation, to highlight its advantages and drawbacks. Finally the advantages of this method are demonstrated for calculating multiple times of flight when the echo is formed by several overlapping echoes. PMID:24284774

  18. Accurate estimation of airborne ultrasonic time-of-flight for overlapping echoes.

    PubMed

    Sarabia, Esther G; Llata, Jose R; Robla, Sandra; Torre-Ferrero, Carlos; Oria, Juan P

    2013-01-01

    In this work, an analysis of the transmission of ultrasonic signals generated by piezoelectric sensors for air applications is presented. Based on this analysis, an ultrasonic response model is obtained for its application to the recognition of objects and structured environments for navigation by autonomous mobile robots. This model enables the analysis of the ultrasonic response that is generated using a pair of sensors in transmitter-receiver configuration using the pulse-echo technique. This is very interesting for recognizing surfaces that simultaneously generate a multiple echo response. This model takes into account the effect of the radiation pattern, the resonant frequency of the sensor, the number of cycles of the excitation pulse, the dynamics of the sensor and the attenuation with distance in the medium. This model has been developed, programmed and verified through a battery of experimental tests. Using this model a new procedure for obtaining accurate time of flight is proposed. This new method is compared with traditional ones, such as threshold or correlation, to highlight its advantages and drawbacks. Finally the advantages of this method are demonstrated for calculating multiple times of flight when the echo is formed by several overlapping echoes. PMID:24284774

  19. Clique graphs and overlapping communities

    NASA Astrophysics Data System (ADS)

    Evans, T. S.

    2010-12-01

    It is shown how to construct a clique graph in which properties of cliques of a fixed order in a given graph are represented by vertices in a weighted graph. Various definitions and motivations for these weights are given. The detection of communities or clusters is used to illustrate how a clique graph may be exploited. In particular a benchmark network is shown where clique graphs find the overlapping communities accurately while vertex partition methods fail.

  20. A Case for More Multiple Scattering Lidar from Space: Analysis of Four LITE Pulses Returned from a Marine Stratocumulus Deck

    NASA Technical Reports Server (NTRS)

    Davis, Anthony B.; Winker, David M.

    2011-01-01

    Outline: (1) Signal Physics for Multiple-Scattering Cloud Lidar, (2) SNR Estimation (3) Cloud Property Retrievals (3a) several techniques (3b) application to Lidar-In-space Technology Experiment (LITE) data (3c) relation to O2 A-band

  1. Multiple-Pulse Sounds and Seals: Results of a Harbor Seal (Phoca vitulina) Telemetry Study During Wind Farm Construction.

    PubMed

    Hastie, Gordon D; Russell, Debbie J F; McConnell, Bernie; Thompson, Dave; Janik, Vincent M

    2016-01-01

    Offshore construction and survey techniques can produce pulsed sounds with a high sound pressure level. In coastal waters, the areas in which they are produced are often also used by seals, potentially resulting in auditory damage or behavioral avoidance. Here, we describe a study on harbor seals during a wind farm installation off southeast England. The study used GPS/global system for mobile communication tags on 23 harbor seals that provided distribution and activity data; the closest range of individual seals to piling varied from 6.65 to 46.1 km. Furthermore, the maximum predicted received levels (RLs) at individual seals varied between 146.9 and 169.4 dB re 1 μPa peak to peak. PMID:26610987

  2. Multiple-Pulse Sounds and Seals: Results of a Harbor Seal (Phoca vitulina) Telemetry Study During Wind Farm Construction.

    PubMed

    Hastie, Gordon D; Russell, Debbie J F; McConnell, Bernie; Thompson, Dave; Janik, Vincent M

    2016-01-01

    Offshore construction and survey techniques can produce pulsed sounds with a high sound pressure level. In coastal waters, the areas in which they are produced are often also used by seals, potentially resulting in auditory damage or behavioral avoidance. Here, we describe a study on harbor seals during a wind farm installation off southeast England. The study used GPS/global system for mobile communication tags on 23 harbor seals that provided distribution and activity data; the closest range of individual seals to piling varied from 6.65 to 46.1 km. Furthermore, the maximum predicted received levels (RLs) at individual seals varied between 146.9 and 169.4 dB re 1 μPa peak to peak.

  3. Design and Evaluation of a Virtual Quadrant Receiver for 4-ary Pulse Position Modulation/Optical Code Division Multiple Access (4-ary PPM/O-CDMA)

    SciTech Connect

    Mendez, A J; Hernandez, V J; Gagliardi, R M; Bennett, C V

    2006-12-29

    M-ary pulse position modulation (M-ary PPM) is an alternative to on-off-keying (OOK) that transmits multiple bits as a single symbol occupying a frame of M slots. PPM does not require thresholding as in OOK signaling, instead performing a comparison test among all slots in a frame to make the slot decision. Combining PPM with optical code division multiple access (PPM/O-CDMA) adds the benefit of supporting multiple concurrent, asynchronous bursty PPM users. While the advantages of PPM/O-CDMA are well known, implementing a receiver that performs comparison test can be difficult. This paper describes the design of a novel array receiver for M-ary PPM/O-CDMA (M = 4) where the received signal is mapped onto an xy-plane whose quadrants define the PPM slot decision by means of an associated control law. The receiver does not require buffering or nonlinear operations. In this paper we describe a planar lightwave circuit (PLCs) implementation of the receiver. We give detailed numerical simulations that test the concept and investigate the effects of multi-access interference (MAI) and optical beat interference (OBI) on the slot decisions. These simulations provide guidelines for subsequent experimental measurements that will be described.

  4. Evaluating the Role of Corticosteroid Pulse Therapy in Patients With Secondary Progressive Multiple Sclerosis Receiving Mitoxantrone: A Double Blind Randomized Controlled Clinical Trial

    PubMed Central

    Rahimdel, Abolghasem; Zeinali, Ahmad; Mellat, Ali

    2015-01-01

    Background: Multiple sclerosis (MS) is a central nervous system disorder with periods of recurrence and recovery. Mitoxantrone has been approved for secondary progressive MS (SPMS) treatment but data lacks the role of corticosteroid pulse therapy in SPMS. Objectives: To evaluate the role of corticosteroid pulse therapy in patients with SPMS receiving mitoxantrone. Patients and Methods: A double blind randomized controlled clinical trial was performed on 71 patients with SPMS referred to Shahid Sadoughi Hospital (Yazd, Iran) for receiving mitoxantrone in two groups. The first group (35 patients) received 20 mg mitoxantrone plus 500 mg methylprednisolone monthly for six months. The second group (36 patients) received the same dosage of mitoxantrone plus 100 CC of 5% dextrose water monthly for six months. Expanded disability status scale (EDSS), MRI plaques in both groups before and after the treatment completion and six months after the end of trial were compared together. Results: 28 men and 43 women enrolled in the study. MRI plaques number reduced in groups significantly (2.29 vs. 2.17) without significant difference between the groups (P = 0.782). Six months after trial completion, plaques number increased in groups without significantly difference (0.72 vs. 0.77, P = 0.611). The mean value of EDSS showed significant reduction at the end of treatment in groups (0.79 and 0.53) without significant difference between the groups (P = 0.953). Six months after trial completion, EDSS increased in groups without significant difference (0.35 vs. 0.43, P = 0.624). Conclusions: Corticosteroid pulse therapy in SPMS was effective in inflammatory process, but could not postpone or decline the neurodegenerative process and besides the imposing side effects could not result in significant improvement in EDSS and MRI plaques number in long term. PMID:26566454

  5. Multiple exciton generation induced enhancement of the photoresponse of pulsed-laser-ablation synthesized single-wall-carbon-nanotube/PbS-quantum-dots nanohybrids

    PubMed Central

    Ka, Ibrahima; Le Borgne, Vincent; Fujisawa, Kazunori; Hayashi, Takuya; Kim, Yoong Ahm; Endo, Morinobu; Ma, Dongling; El Khakani, My Ali

    2016-01-01

    The pulsed laser deposition method was used to decorate appropriately single wall carbon nanotubes (SWCNTs) with PbS quantum dots (QDs), leading to the formation of a novel class of SWCNTs/PbS-QDs nanohybrids (NHs), without resorting to any ligand engineering and/or surface functionalization. The number of laser ablation pulses (NLp) was used to control the average size of the PbS-QDs and their coverage on the SWCNTs’ surface. Photoconductive (PC) devices fabricated from these SWCNTs/PbS-QDs NHs have shown a significantly enhanced photoresponse, which is found to be PbS-QD size dependent. Wavelength-resolved photocurrent measurements revealed a strong photoconductivity of the NHs in the UV-visible region, which is shown to be due to multiple exciton generation (MEG) in the PbS-QDs. For the 6.5 nm-diameter PbS-QDs (with a bandgap (Eg) = 0.86 eV), the MEG contribution of the NHs based PC devices was shown to lead to a normalized internal quantum efficiency in excess of 300% for photon energies ≥4.5Eg. While the lowest MEG threshold in our NHs based PC devices is found to be of ~2.5Eg, the MEG efficiency reaches values as high as 0.9 ± 0.1. PMID:26830452

  6. Effect of multiple short highly energetic X-ray pulses on the synthesis of endoglucanase by a mutant strain of Trichoderma reesei-M7

    PubMed Central

    Gemishev, Orlin; Zapryanov, Stanislav; Blagoev, Alexander; Markova, Maya; Savov, Valentin

    2014-01-01

    Bioconversion of cellulose-containing substrate to glucose represents an important area of modern biotechnology. Enzymes for the degradation of the polysaccharide part of biomass have been produced, mostly by fungi belonging to genus Trichoderma. Studies were carried out with the mutant strain Trichoderma reesei-M7, a cellulase producer. Spores of the enzyme producer were irradiated with different doses of characteristic X-ray radiation from metallic tungsten (mainly the W Kα1 and Kα2 lines) with a high dose rate. The latter is a specific property of the dense plasma focus (DPF) device, which has pulsed operation and thus gives short and highly energetic pulses of multiple types of rays and particles. In this case, we focused our study on the influence of hard X-rays. The doses of X-rays absorbed by the spores varied in the range of approximately 5–11,000 mSv measured with thermoluminescent dosimeters (TLD). The influence of the applied doses in combination with exceptionally high dose rates (in the order of tens of millisieverts per microsecond) on the activity of the produced endoglucanase, amount of biomass and extra-cellular protein, was studied in batch cultivation conditions. In the dose range of 200–1200 mSv, some enhancement of endoglucanase activity was obtained: around 18%–32%, despite the drop of the biomass amount, compared with the untreated material. PMID:26019569

  7. Multiple exciton generation induced enhancement of the photoresponse of pulsed-laser-ablation synthesized single-wall-carbon-nanotube/PbS-quantum-dots nanohybrids

    NASA Astrophysics Data System (ADS)

    Ka, Ibrahima; Le Borgne, Vincent; Fujisawa, Kazunori; Hayashi, Takuya; Kim, Yoong Ahm; Endo, Morinobu; Ma, Dongling; El Khakani, My Ali

    2016-02-01

    The pulsed laser deposition method was used to decorate appropriately single wall carbon nanotubes (SWCNTs) with PbS quantum dots (QDs), leading to the formation of a novel class of SWCNTs/PbS-QDs nanohybrids (NHs), without resorting to any ligand engineering and/or surface functionalization. The number of laser ablation pulses (NLp) was used to control the average size of the PbS-QDs and their coverage on the SWCNTs’ surface. Photoconductive (PC) devices fabricated from these SWCNTs/PbS-QDs NHs have shown a significantly enhanced photoresponse, which is found to be PbS-QD size dependent. Wavelength-resolved photocurrent measurements revealed a strong photoconductivity of the NHs in the UV-visible region, which is shown to be due to multiple exciton generation (MEG) in the PbS-QDs. For the 6.5 nm-diameter PbS-QDs (with a bandgap (Eg) = 0.86 eV), the MEG contribution of the NHs based PC devices was shown to lead to a normalized internal quantum efficiency in excess of 300% for photon energies ≥4.5Eg. While the lowest MEG threshold in our NHs based PC devices is found to be of ~2.5Eg, the MEG efficiency reaches values as high as 0.9 ± 0.1.

  8. Multiple exciton generation induced enhancement of the photoresponse of pulsed-laser-ablation synthesized single-wall-carbon-nanotube/PbS-quantum-dots nanohybrids.

    PubMed

    Ka, Ibrahima; Le Borgne, Vincent; Fujisawa, Kazunori; Hayashi, Takuya; Kim, Yoong Ahm; Endo, Morinobu; Ma, Dongling; El Khakani, My Ali

    2016-01-01

    The pulsed laser deposition method was used to decorate appropriately single wall carbon nanotubes (SWCNTs) with PbS quantum dots (QDs), leading to the formation of a novel class of SWCNTs/PbS-QDs nanohybrids (NHs), without resorting to any ligand engineering and/or surface functionalization. The number of laser ablation pulses (NLp) was used to control the average size of the PbS-QDs and their coverage on the SWCNTs' surface. Photoconductive (PC) devices fabricated from these SWCNTs/PbS-QDs NHs have shown a significantly enhanced photoresponse, which is found to be PbS-QD size dependent. Wavelength-resolved photocurrent measurements revealed a strong photoconductivity of the NHs in the UV-visible region, which is shown to be due to multiple exciton generation (MEG) in the PbS-QDs. For the 6.5 nm-diameter PbS-QDs (with a bandgap (Eg) = 0.86 eV), the MEG contribution of the NHs based PC devices was shown to lead to a normalized internal quantum efficiency in excess of 300% for photon energies ≥4.5Eg. While the lowest MEG threshold in our NHs based PC devices is found to be of ~2.5Eg, the MEG efficiency reaches values as high as 0.9 ± 0.1. PMID:26830452

  9. The Influence of Sex and Season on Conspecific Spatial Overlap in a Large, Actively-Foraging Colubrid Snake

    PubMed Central

    Bauder, Javan M.; Breininger, David R.; Bolt, M. Rebecca; Legare, Michael L.; Jenkins, Christopher L.; Rothermel, Betsie B.; McGarigal, Kevin

    2016-01-01

    Understanding the factors influencing the degree of spatial overlap among conspecifics is important for understanding multiple ecological processes. Compared to terrestrial carnivores, relatively little is known about the factors influencing conspecific spatial overlap in snakes, although across snake taxa there appears to be substantial variation in conspecific spatial overlap. In this study, we described conspecific spatial overlap of eastern indigo snakes (Drymarchon couperi) in peninsular Florida and examined how conspecific spatial overlap varied by sex and season (breeding season vs. non-breeding season). We calculated multiple indices of spatial overlap using 6- and 3-month utilization distributions (UD) of dyads of simultaneously adjacent telemetered snakes. We also measured conspecific UD density values at each telemetry fix and modeled the distribution of those values as a function of overlap type, sex, and season using generalized Pareto distributions. Home range overlap between males and females was significantly greater than overlap between individuals of the same sex and male home ranges often completely contained female home ranges. Male home ranges overlapped little during both seasons, whereas females had higher levels of overlap during the non-breeding season. The spatial patterns observed in our study are consistent with those seen in many mammalian carnivores, in which low male-male overlap and high inter-sexual overlap provides males with greater access to females. We encourage additional research on the influence of prey availability on conspecific spatial overlap in snakes as well as the behavioral mechanisms responsible for maintaining the low levels of overlap we observed. PMID:27490346

  10. The Influence of Sex and Season on Conspecific Spatial Overlap in a Large, Actively-Foraging Colubrid Snake.

    PubMed

    Bauder, Javan M; Breininger, David R; Bolt, M Rebecca; Legare, Michael L; Jenkins, Christopher L; Rothermel, Betsie B; McGarigal, Kevin

    2016-01-01

    Understanding the factors influencing the degree of spatial overlap among conspecifics is important for understanding multiple ecological processes. Compared to terrestrial carnivores, relatively little is known about the factors influencing conspecific spatial overlap in snakes, although across snake taxa there appears to be substantial variation in conspecific spatial overlap. In this study, we described conspecific spatial overlap of eastern indigo snakes (Drymarchon couperi) in peninsular Florida and examined how conspecific spatial overlap varied by sex and season (breeding season vs. non-breeding season). We calculated multiple indices of spatial overlap using 6- and 3-month utilization distributions (UD) of dyads of simultaneously adjacent telemetered snakes. We also measured conspecific UD density values at each telemetry fix and modeled the distribution of those values as a function of overlap type, sex, and season using generalized Pareto distributions. Home range overlap between males and females was significantly greater than overlap between individuals of the same sex and male home ranges often completely contained female home ranges. Male home ranges overlapped little during both seasons, whereas females had higher levels of overlap during the non-breeding season. The spatial patterns observed in our study are consistent with those seen in many mammalian carnivores, in which low male-male overlap and high inter-sexual overlap provides males with greater access to females. We encourage additional research on the influence of prey availability on conspecific spatial overlap in snakes as well as the behavioral mechanisms responsible for maintaining the low levels of overlap we observed. PMID:27490346

  11. Radial sets: interactive visual analysis of large overlapping sets.

    PubMed

    Alsallakh, Bilal; Aigner, Wolfgang; Miksch, Silvia; Hauser, Helwig

    2013-12-01

    In many applications, data tables contain multi-valued attributes that often store the memberships of the table entities to multiple sets such as which languages a person masters, which skills an applicant documents, or which features a product comes with. With a growing number of entities, the resulting element-set membership matrix becomes very rich of information about how these sets overlap. Many analysis tasks targeted at set-typed data are concerned with these overlaps as salient features of such data. This paper presents Radial Sets, a novel visual technique to analyze set memberships for a large number of elements. Our technique uses frequency-based representations to enable quickly finding and analyzing different kinds of overlaps between the sets, and relating these overlaps to other attributes of the table entities. Furthermore, it enables various interactions to select elements of interest, find out if they are over-represented in specific sets or overlaps, and if they exhibit a different distribution for a specific attribute compared to the rest of the elements. These interactions allow formulating highly-expressive visual queries on the elements in terms of their set memberships and attribute values. As we demonstrate via two usage scenarios, Radial Sets enable revealing and analyzing a multitude of overlapping patterns between large sets, beyond the limits of state-of-the-art techniques. PMID:24051816

  12. Grid adaptation using chimera composite overlapping meshes

    NASA Technical Reports Server (NTRS)

    Kao, Kai-Hsiung; Liou, Meng-Sing; Chow, Chuen-Yen

    1994-01-01

    The objective of this paper is to perform grid adaptation using composite overlapping meshes in regions of large gradient to accurately capture the salient features during computation. The chimera grid scheme, a multiple overset mesh technique, is used in combination with a Navier-Stokes solver. The numerical solution is first converged to a steady state based on an initial coarse mesh. Solution-adaptive enhancement is then performed by using a secondary fine grid system which oversets on top of the base grid in the high-gradient region, but without requiring the mesh boundaries to join in any special way. Communications through boundary interfaces between those separated grids are carried out using trilinear interpolation. Application to the Euler equations for shock reflections and to shock wave/boundary layer interaction problem are tested. With the present method, the salient features are well-resolved.

  13. Grid adaptation using Chimera composite overlapping meshes

    NASA Technical Reports Server (NTRS)

    Kao, Kai-Hsiung; Liou, Meng-Sing; Chow, Chuen-Yen

    1993-01-01

    The objective of this paper is to perform grid adaptation using composite over-lapping meshes in regions of large gradient to capture the salient features accurately during computation. The Chimera grid scheme, a multiple overset mesh technique, is used in combination with a Navier-Stokes solver. The numerical solution is first converged to a steady state based on an initial coarse mesh. Solution-adaptive enhancement is then performed by using a secondary fine grid system which oversets on top of the base grid in the high-gradient region, but without requiring the mesh boundaries to join in any special way. Communications through boundary interfaces between those separated grids are carried out using tri-linear interpolation. Applications to the Euler equations for shock reflections and to a shock wave/boundary layer interaction problem are tested. With the present method, the salient features are well resolved.

  14. Grid adaption using Chimera composite overlapping meshes

    NASA Technical Reports Server (NTRS)

    Kao, Kai-Hsiung; Liou, Meng-Sing; Chow, Chuen-Yen

    1993-01-01

    The objective of this paper is to perform grid adaptation using composite over-lapping meshes in regions of large gradient to capture the salient features accurately during computation. The Chimera grid scheme, a multiple overset mesh technique, is used in combination with a Navier-Stokes solver. The numerical solution is first converged to a steady state based on an initial coarse mesh. Solution-adaptive enhancement is then performed by using a secondary fine grid system which oversets on top of the base grid in the high-gradient region, but without requiring the mesh boundaries to join in any special way. Communications through boundary interfaces between those separated grids are carried out using tri-linear interpolation. Applications to the Euler equations for shock reflections and to a shock wave/boundary layer interaction problem are tested. With the present method, the salient features are well resolved.

  15. Overlapped Fourier coding for optical aberration removal

    PubMed Central

    Horstmeyer, Roarke; Ou, Xiaoze; Chung, Jaebum; Zheng, Guoan; Yang, Changhuei

    2014-01-01

    We present an imaging procedure that simultaneously optimizes a camera’s resolution and retrieves a sample’s phase over a sequence of snapshots. The technique, termed overlapped Fourier coding (OFC), first digitally pans a small aperture across a camera’s pupil plane with a spatial light modulator. At each aperture location, a unique image is acquired. The OFC algorithm then fuses these low-resolution images into a full-resolution estimate of the complex optical field incident upon the detector. Simultaneously, the algorithm utilizes redundancies within the acquired dataset to computationally estimate and remove unknown optical aberrations and system misalignments via simulated annealing. The result is an imaging system that can computationally overcome its optical imperfections to offer enhanced resolution, at the expense of taking multiple snapshots over time. PMID:25321982

  16. The evolutionary diversification of parrots supports a taxon pulse model with multiple trans-oceanic dispersal events and local radiations.

    PubMed

    Schweizer, Manuel; Seehausen, Ole; Güntert, Marcel; Hertwig, Stefan T

    2010-03-01

    Vicariance is thought to have played a major role in the evolution of modern parrots. However, as the relationships especially of the African taxa remained mostly unresolved, it has been difficult to draw firm conclusions about the roles of dispersal and vicariance. Our analyses using the broadest taxon sampling of old world parrots ever based on 3219bp of three nuclear genes revealed well-resolved and congruent phylogenetic hypotheses. Agapornis of Africa and Madagascar was found to be the sister group to Loriculus of Australasia and Indo-Malayasia and together they clustered with the Australasian Loriinae, Cyclopsittacini and Melopsittacus. Poicephalus and Psittacus from mainland Africa formed the sister group of the Neotropical Arini and Coracopsis from Madagascar and adjacent islands may be the closest relative of Psittrichas from New Guinea. These biogeographic relationships are best explained by independent colonization of the African continent via trans-oceanic dispersal from Australasia and Antarctica in the Paleogene following what may have been vicariance events in the late Cretaceous and/or early Paleogene. Our data support a taxon pulse model for the diversification of parrots whereby trans-oceanic dispersal played a more important role than previously thought and was the prerequisite for range expansion into new continents.

  17. Hospital mergers and market overlap.

    PubMed Central

    Brooks, G R; Jones, V G

    1997-01-01

    OBJECTIVE: To address two questions: What are the characteristics of hospitals that affect the likelihood of their being involved in a merger? What characteristics of particular pairs of hospitals affect the likelihood of the pair engaging in a merger? DATA SOURCES/STUDY SETTING: Hospitals in the 12 county region surrounding the San Francisco Bay during the period 1983 to 1992 were the focus of the study. Data were drawn from secondary sources, including the Lexis/Nexis database, the American Hospital Association, and the Office of Statewide Health Planning and Development of the State of California. STUDY DESIGN: Seventeen hospital mergers during the study period were identified. A random sample of pairs of hospitals that did not merge was drawn to establish a statistically efficient control set. Models constructed from hypotheses regarding hospital and market characteristics believed to be related to merger likelihood were tested using logistic regression analysis. DATA COLLECTION: See Data Sources/Study Setting. PRINCIPAL FINDINGS: The analysis shows that the likelihood of a merger between a particular pair of hospitals is positively related to the degree of market overlap that exists between them. Furthermore, market overlap and performance difference interact in their effect on merger likelihood. In an analysis of individual hospitals, conditions of rivalry, hospital market share, and hospital size were not found to influence the likelihood that a hospital will engage in a merger. CONCLUSIONS: Mergers between hospitals are not driven directly by considerations of market power or efficiency as much as by the existence of specific merger opportunities in the hospitals' local markets. Market overlap is a condition that enables a merger to occur, but other factors, such as the relative performance levels of the hospitals in question and their ownership and teaching status, also play a role in influencing the likelihood that a merger will in fact take place. PMID

  18. New geologic mapping combined with geochemical, paleomagnetic, and high-precision 40Ar/39Ar analyses reveal multiple overlapping calderas formed 16.4-15.7 Ma at High Rock caldera complex, northwestern Nevada

    NASA Astrophysics Data System (ADS)

    Coble, M. A.; Mahood, G. A.

    2012-12-01

    We present new evidence from 1:100,000- and 1:24,000-scale geologic mapping for the presence of at least four overlapping calderas, 24 to 40 km in diameter, that formed in an interval of only 0.7 m.y. during the mid-Miocene at High Rock caldera complex in northwest Nevada and southern Oregon. In total, an estimated minimum volume of ~725 km3 of rhyolitic magma erupted from the complex between 16.5 and 15.5 Ma, covering an area of ~9,000 km2. Rapid eruption of numerous units at volumetric rates as high as 3,000-4,000 km3/m.y., strong welding of lithic-poor ignimbrites, extensive vapor-phase alteration of lavas and ignimbrites alike, a limited range of phenocryst content and assemblage, silicification along faults, and a lack of well-exposed stratigraphic sections has hindered previous reconnaissance-scale mapping and identification of caldera centers. Calderas are located based on truncation of precaldera rhyolitic lavas by caldera topographic walls, by arcuate patterns of rhyolite lavas that erupted along buried caldera ring faults, and by the presence of pumiceous caldera lake sediments. We attribute formation of the Virgin Valley, Badger Mountain, Hanging Rock, and Cottonwood Creek Calderas to collapse on eruption, respectively, of the ca. 16.37 Ma Idaho Canyon Tuff, the 16.34 Ma Summit Lake Tuff, the 16.0 Ma Soldier Meadows Tuff, and the 15.7 Ma Tuff of Yellow Rock Canyon. Additional smaller-volume pyroclastic units erupted during emplacement of geochemically similar rhyolitic lavas. More than 60 new 40Ar/39Ar ages were obtained on ignimbrites, fall deposits, and rhyolitic, trachytic and basaltic lavas. Many of the eruptive units in the HRCC differ in age by less than 100 k.y., which, at ca. 16 Ma, requires precision at the 1-2‰ (2σ standard error) level to distinguish units using 40Ar/39Ar geochronology. The high-precision of the analyses of sanidine in the rhyolites, coupled with geochemical and paleomagnetic measurements, allowed us to correlate far

  19. Diagnostics of atmospheric-pressure pulsed-dc discharge with metal and liquid anodes by multiple laser-aided methods

    NASA Astrophysics Data System (ADS)

    Urabe, Keiichiro; Shirai, Naoki; Tomita, Kentaro; Akiyama, Tsuyoshi; Murakami, Tomoyuki

    2016-08-01

    The density and temperature of electrons and key heavy particles were measured in an atmospheric-pressure pulsed-dc helium discharge plasma with a nitrogen molecular impurity generated using system with a liquid or metal anode and a metal cathode. To obtain these parameters, we conducted experiments using several laser-aided methods: Thomson scattering spectroscopy to obtain the spatial profiles of electron density and temperature, Raman scattering spectroscopy to obtain the neutral molecular nitrogen rotational temperature, phase-modulated dispersion interferometry to determine the temporal variation of the electron density, and time-resolved laser absorption spectroscopy to analyze the temporal variation of the helium metastable atom density. The electron density and temperature measured by Thomson scattering varied from 2.4  ×  1014 cm-3 and 1.8 eV at the center of the discharge to 0.8  ×  1014 cm-3 and 1.5 eV near the outer edge of the plasma in the case of the metal anode, respectively. The electron density obtained with the liquid anode was approximately 20% smaller than that obtained with the metal anode, while the electron temperature was not significantly affected by the anode material. The molecular nitrogen rotational temperatures were 1200 K with the metal anode and 1650 K with the liquid anode at the outer edge of the plasma column. The density of helium metastable atoms decreased by a factor of two when using the liquid anode.

  20. Evidence for multiple pulses of crystal-bearing magma during emplacement of the Doros layered intrusion, Namibia

    NASA Astrophysics Data System (ADS)

    Owen-Smith, T. M.; Ashwal, L. D.

    2015-12-01

    The Doros Complex is a relatively small (maximum 3.5 km × 7.5 km) shallow-level, lopolithic, layered mafic intrusion in the early Cretaceous Paraná-Etendeka Large Igneous Province. The stratigraphy broadly comprises a minor, fine-grained gabbroic sill and a sequence of primitive olivine-cumulate melagabbros, with a basal chilled margin, an intermediate plagioclase-cumulate olivine gabbro, and a sequence of mineralogically and texturally variable, intermediate, strongly foliated, plagioclase-, olivine- or magnetite-cumulate gabbros. An evolved syenitic (bostonite) phase occurs as cross-cutting dykes or as enclaves within the foliated gabbros. Major element modelling of the liquid line of descent shows that the spectrum of rock types, including the bostonite, is consistent with the fractionation of a basaltic parental magma that crystallised olivine, clinopyroxene, plagioclase, magnetite, K-feldspar and apatite. However, the stratigraphic succession does not correspond to a simple progressive differentiation trend but instead shows a series of punctuated trends, each defined by a compositional reversal or hiatus. Incompatible trace element concentrations do not increase upwards though the body of the intrusion. The major units show similar, mildly enriched rare earth element patterns, with minimal Eu anomalies. Back-calculation of the rare earth element concentrations of these cumulate rocks produces relatively evolved original liquid compositions, indicating fractionation of this liquid from a more primitive precursor. Based on combined field, petrographic, geochemical and geophysical evidence, we propose an origin for the Doros Complex by a minimum of seven closely spaced influxes of crystal-bearing magmas, each with phenocryst contents between 5% and 55%. These findings represent a departure from the traditional single-pulse liquid model for the formation of layered mafic intrusions and suggest the presence of an underlying magmatic mush column, i.e., a large

  1. Diagnostics of atmospheric-pressure pulsed-dc discharge with metal and liquid anodes by multiple laser-aided methods

    NASA Astrophysics Data System (ADS)

    Urabe, Keiichiro; Shirai, Naoki; Tomita, Kentaro; Akiyama, Tsuyoshi; Murakami, Tomoyuki

    2016-08-01

    The density and temperature of electrons and key heavy particles were measured in an atmospheric-pressure pulsed-dc helium discharge plasma with a nitrogen molecular impurity generated using system with a liquid or metal anode and a metal cathode. To obtain these parameters, we conducted experiments using several laser-aided methods: Thomson scattering spectroscopy to obtain the spatial profiles of electron density and temperature, Raman scattering spectroscopy to obtain the neutral molecular nitrogen rotational temperature, phase-modulated dispersion interferometry to determine the temporal variation of the electron density, and time-resolved laser absorption spectroscopy to analyze the temporal variation of the helium metastable atom density. The electron density and temperature measured by Thomson scattering varied from 2.4  ×  1014 cm‑3 and 1.8 eV at the center of the discharge to 0.8  ×  1014 cm‑3 and 1.5 eV near the outer edge of the plasma in the case of the metal anode, respectively. The electron density obtained with the liquid anode was approximately 20% smaller than that obtained with the metal anode, while the electron temperature was not significantly affected by the anode material. The molecular nitrogen rotational temperatures were 1200 K with the metal anode and 1650 K with the liquid anode at the outer edge of the plasma column. The density of helium metastable atoms decreased by a factor of two when using the liquid anode.

  2. [Asthma-COPD overlap syndrome].

    PubMed

    Odler, Balázs; Müller, Veronika

    2016-08-01

    Obstructive lung diseases represent a major health problem worldwide due to their high prevalence associated with elevated socioeconomic costs. Bronchial asthma and chronic obstructive pulmonary disease are chronic obstructive ventilatory disorders with airway inflammation, however they are separate nosological entities based on thedifferent development, diagnostic and therapeutic approaches, and prognostic features. However, these diseases may coexist and can be defined as the coexistence of increased variability of airflow in a patient with incompletely reversible airway obstruction. This phenotype is called asthma - chronic obstructive pulmonary disease overlap syndrome. The syndrome is a clinical and scientific challenge as the majority of these patients have been excluded from the clinical and pharmacological trials, thus well-defined clinical characteristics and therapeutic approaches are lacking. The aim of this review is to summarize the currently available literature focusing on pathophysiological and clinical features, and discuss possible therapeutic approaches of patients with asthma - chronic obstructive pulmonary disease overlap syndrome. Orv. Hetil., 2016, 157(33), 1304-1313. PMID:27523313

  3. Item Overlap Correlations: Definitions, Interpretations, and Implications.

    ERIC Educational Resources Information Center

    Hsu, Louis M.

    1994-01-01

    Item overlap coefficient (IOC) formulas are discussed, providing six warnings about their calculation and interpretation and some explanations of why item overlap influences the Minnesota Multiphasic Personality Inventory and the Millon Clinical Multiaxial Inventory factor structures. (SLD)

  4. Multiple-pulsed debris avalanche emplacement at Mount St. Helens in 1980: Evidence from numerical continuum flow simulations

    NASA Astrophysics Data System (ADS)

    Sousa, James; Voight, Barry

    1995-07-01

    The complex 1980 Mount St. Helens debris avalanche is modeled numerically as a transient biviscous fluid flow. Several approaches are considered, including two-step rheologically-distinct models for avalanche I and combined avalanches II/III, and a composite flow model consisting of retrogressive slides of identical rheology successively accreted to the main avalanche flow. For the two-step situation, flow rheologies are evaluated separately for the initial avalanche, comprising the debris avalanche block facies, and an ensuing explosive-influenced flow. Strengths (normalized by density) as high as 250 m 2/s 2 and apparent Newtonian viscosities as much as 275 m 2/s were established for the block facies. These parameters for the explosively-influenced flow are an order of magnitude lower. The distribution of stratigraphic units within flowing model debris, compared with field distributions, suggests that the higher-strength emplacement models are appropriate for debris deposited on Johnston Ridge and in the upper parts and flanks of the North Fork Toutle River valley. In general, models for which constant rheology is assumed throughout the flow process provide lower-bound emplacement times, and excessive early velocities, as compared to the prototype event. Because model calibration is based on matching runout by trial and error, it is therefore biased toward the rheologic parameters essential to achieving that runout. These values characterize the flow in its latter stages, whereas the actual strength and viscosity may have substantially decreased as a function of displacement. Two-dimensional models predict debris accumulation about twice as thick as that observed at the foot of Mount St. Helens, where flow divergence was significant. This discrepancy is lessened with a quasi-three-dimensional modification of the flow model. Accretionary composite flow models with homogeneous rheology simulate the overriding of early avalanche debris by later debris pulses. The

  5. Overlap in Facebook Profiles Reflects Relationship Closeness.

    PubMed

    Castañeda, Araceli M; Wendel, Markie L; Crockett, Erin E

    2015-01-01

    We assessed the association between self-reported Inclusion of Other in the Self (IOS) and Facebook overlap. Ninety-two participants completed online measures of IOS and investment model constructs. Researchers then recorded Facebook data from participants' profile pages. Results from multilevel models revealed that IOS predicted Facebook overlap. Furthermore, Facebook overlap was associated with commitment and investment in ways comparable to self-reported IOS. These findings suggest that overlap in Facebook profiles can be used to measure relationship closeness.

  6. Near perfect mode overlap between independently seeded, gain-switched lasers

    NASA Astrophysics Data System (ADS)

    Comandar, L. C.; Lucamarini, M.; Fröhlich, B.; Dynes, J. F.; Yuan, Z. L.; Shields, A. J.

    2016-08-01

    We drastically improve the mode overlap between independently seeded, gain-switched laser diodes operating at gigahertz repetition rates by implementing a pulsed light seeding technique. Injecting pulsed light reduces the emission time jitter and enables frequency chirp synchronization while maintaining random optical phases of the emitted laser pulses. We measure interference of these pulsed sources both in the macroscopic regime, where we demonstrate near perfect mode overlap, and in the single photon regime, where we achieve a Hong-Ou-Mandel dip visibility of 0.499+/-0.004, thus saturating the theoretical limit of 0.5. The measurement results are reproduced by Monte-Carlo simulations with no free parameters. Our light source is an ideal solution for generation of high rate, indistinguishable coherent pulses for quantum information applications.

  7. Magnetic resonance imaging of myelin using ultrashort Echo time (UTE) pulse sequences: Phantom, specimen, volunteer and multiple sclerosis patient studies.

    PubMed

    Sheth, Vipul; Shao, Hongda; Chen, Jun; Vandenberg, Scott; Corey-Bloom, Jody; Bydder, Graeme M; Du, Jiang

    2016-08-01

    Clinical magnetic resonance imaging of multiple sclerosis (MS) has focused on indirect imaging of myelin in white matter by detecting signal from protons in the water associated with myelin. Here we show that protons in myelin can be directly imaged using ultrashort echo time (UTE) free induction decay (FID) and imaging sequences on a clinical 3T MR scanner. An adiabatic inversion recovery UTE (IR-UTE) sequence was used to detect signal from myelin and simultaneously suppress signal from water protons. Validation studies were performed on myelin lipid and myelin basic protein (MBP) phantoms in the forms of lyophilized powders as well as suspensions in D2O and H2O. IR-UTE sequences were then used to image MS brain specimens, healthy volunteers, and patients. The T2* of myelin was measured using a UTE FID sequence, as well as UTE and IR-UTE sequences at different TEs. T2* values of ~110-330μs were measured with UTE FID, as well as with UTE and IR-UTE sequences for myelin powders, myelin-D2O and myelin-H2O phantoms, consistent with selective imaging of myelin protons with IR-UTE sequences. Our studies showed myelin selective imaging of white matter in the brains in vitro and in vivo. Complete or partial signal loss was observed in specimens in areas of the brain with histopathologic evidence of myelin loss, and in the brain of patients with MS.

  8. On Multigrid for Overlapping Grids

    SciTech Connect

    Henshaw, W

    2004-01-13

    The solution of elliptic partial differential equations on composite overlapping grids using multigrid is discussed. An approach is described that provides a fast and memory efficient scheme for the solution of boundary value problems in complex geometries. The key aspects of the new scheme are an automatic coarse grid generation algorithm, an adaptive smoothing technique for adjusting residuals on different component grids, and the use of local smoothing near interpolation boundaries. Other important features include optimizations for Cartesian component grids, the use of over-relaxed Red-Black smoothers and the generation of coarse grid operators through Galerkin averaging. Numerical results in two and three dimensions show that very good multigrid convergence rates can be obtained for both Dirichlet and Neumann/mixed boundary conditions. A comparison to Krylov based solvers shows that the multigrid solver can be much faster and require significantly less memory.

  9. Photoimaging of the multiple filamentation of femtosecond laser pulses in poly(methyl methacrylate) doped with 2,2-difluoro-4-(9-anthracyl)-6-methyl-1,3,2-dioxaborine

    SciTech Connect

    Kulchin, Yu N; Vitrik, O B; Chekhlenok, A A; Zhizhchenko, A Yu; Proschenko, D Yu; Mirochnik, A G; Lyu Guohui

    2013-12-31

    We have studied the filamentation of femtosecond laser pulses (λ = 800 nm, ∼42 fs pulse duration) in poly(methyl methacrylate) doped with 2,2-difluoro-4-(9-anthracyl)-6-methyl-1,3,2- dioxaborine and the associated photomodification of the material. The results demonstrate that multiple filamentation occurs at pulse energies above 5 μJ. At a pulse energy of 1.5 mJ, it is accompanied by supercontinuum generation. The average filament length in PMMA is 9 mm and the filament diameter is ∼10 μm. An incident power density of ∼10{sup 12} W cm{sup -2} ensures inscription of the filament pattern owing to two-photon photochemical processes. Preliminary exposure to continuous light at λ = 400 nm enables an ordered filament pattern to be written. (interaction of laser radiation with matter)

  10. Overlapping Structures in Sensory-Motor Mappings

    PubMed Central

    Earland, Kevin; Lee, Mark; Shaw, Patricia; Law, James

    2014-01-01

    This paper examines a biologically-inspired representation technique designed for the support of sensory-motor learning in developmental robotics. An interesting feature of the many topographic neural sheets in the brain is that closely packed receptive fields must overlap in order to fully cover a spatial region. This raises interesting scientific questions with engineering implications: e.g. is overlap detrimental? does it have any benefits? This paper examines the effects and properties of overlap between elements arranged in arrays or maps. In particular we investigate how overlap affects the representation and transmission of spatial location information on and between topographic maps. Through a series of experiments we determine the conditions under which overlap offers advantages and identify useful ranges of overlap for building mappings in cognitive robotic systems. Our motivation is to understand the phenomena of overlap in order to provide guidance for application in sensory-motor learning robots. PMID:24392118

  11. Identifying Overlapping Language Communities: The Case of Chiriquí and Panamanian Signed Languages

    ERIC Educational Resources Information Center

    Parks, Elizabeth S.

    2016-01-01

    In this paper, I use a holographic metaphor to explain the identification of overlapping sign language communities in Panama. By visualizing Panama's complex signing communities as emitting community "hotspots" through social drama on multiple stages, I employ ethnographic methods to explore overlapping contours of Panama's sign language…

  12. Effects of picosecond terawatt UV laser beam filamentation and a repetitive pulse train on creation of prolonged plasma channels in atmospheric air

    NASA Astrophysics Data System (ADS)

    Zvorykin, V. D.; Ionin, A. A.; Levchenko, A. O.; Seleznev, L. V.; Shutov, A. V.; Sinitsyn, D. V.; Smetanin, I. V.; Ustinovskii, N. N.

    2013-08-01

    Amplitude-modulated UV laser pulse of up to 30 J energy was produced at hybrid Ti:Sapphire/KrF GARPUN-MTW laser facility when a preliminary amplified train of short pulses was injected into unstable resonator cavity of the main e-beam-pumped KrF amplifier. The combined radiation consisted of regeneratively amplified picosecond pulses with subTW peak power overlapped with 100-ns pulse of a free-running lasing. The advantages of combined radiation for production of long-lived prolonged plasma channels in air and HV discharge triggering were demonstrated: photocurrent sustained by modulated pulse is two orders of magnitude higher and HV breakdown distance is twice longer than for a smooth UV pulse. It was found that in contrast to IR radiation multiple filamentation of high-power UV laser beam does not produce extended nonlinear focusing of UV radiation.

  13. Investigation into the structural composition of hydroalcoholic solutions as basis for the development of multiple suppression pulse sequences for NMR measurement of alcoholic beverages.

    PubMed

    Monakhova, Yulia B; Mushtakova, Svetlana P; Kuballa, Thomas; Lachenmeier, Dirk W

    2014-12-01

    An eight-fold suppression pulse sequence was recently developed to improve sensitivity in (1) H NMR measurements of alcoholic beverages [Magn. Res. Chem. 2011 (49): 734-739]. To ensure that only one combined hydroxyl peak from water and ethanol appears in the spectrum, adjustment to a certain range of ethanol concentrations was required. To explain this observation, the structure of water-ethanol solutions was studied. Hydroalcoholic solutions showed extreme behavior at 25% vol, 46% vol, and 83% vol ethanol according to (1) H NMR experiments. Near-infrared spectroscopy confirmed the occurrence of four significant compounds ('individual' ethanol and water structures as well as two water-ethanol complexes of defined composition - 1 : 1 and 1 : 3). The successful multiple suppression can be achieved for every kind of alcoholic beverage with different alcoholic strengths, when the final ethanol concentration is adjusted to a range between 25% vol and 46% vol (e.g. using dilution or pure ethanol addition). In this optimum region, an individual ethanol peak was not detected, because the 'individual' water structure and the 1 : 1 ethanol-water complex predominate. The nature of molecular association in ethanol-water solutions is essential to elucidate NMR method development for measurement of alcoholic beverages. The presented approach can be used to optimize other NMR suppression protocols for binary water-organic solvent mixtures, where hydrogen bonding plays a dominant role.

  14. Flow injection simultaneous determination of synthetic colorants in food using multiple pulse amperometric detection with a boron-doped diamond electrode.

    PubMed

    Medeiros, Roberta A; Lourencao, Bruna C; Rocha-Filho, Romeu C; Fatibello-Filho, Orlando

    2012-09-15

    A single-line flow injection system and multiple pulse amperometric detection using a boron-doped diamond electrode were employed to develop and optimize a simple, low-cost, and rapid method for the simultaneous determination of two pairs of food colorants: tartrazine and sunset yellow (TT-SY) or brilliant blue and SY (BB-SY). A dual-potential waveform was used: E(det.1)=-150 mV (400 ms duration) and E(det.2)=-450 mV (100 ms duration) vs. Ag/AgCl (3.0 mol L(-1) KCl). Polarization at E(det.1) or E(det.2) causes reduction of SY or the respective pair of colorants, TT-SY or BB-SY; hence, with proper current correction, both colorants in each pair can be determined. The obtained linear response ranges (detection limits) were 5.0-60.0 (2.5) and 1.0-50.0 (0.80) μmol L(-1), for TT and SY, or 5.0-60.0 (3.5) and 1.0-50.0 (0.85) μmol L(-1), for BB and SY, respectively. Investigation of possible interferents (other food colorants or additives) showed no significant interference with the methods here proposed, which were then used to simultaneously determine the pairs of colorants in industrialized food samples, with results that showed good agreement with those obtained using a comparative HPLC method.

  15. Solving Partial Differential Equations on Overlapping Grids

    SciTech Connect

    Henshaw, W D

    2008-09-22

    We discuss the solution of partial differential equations (PDEs) on overlapping grids. This is a powerful technique for efficiently solving problems in complex, possibly moving, geometry. An overlapping grid consists of a set of structured grids that overlap and cover the computational domain. By allowing the grids to overlap, grids for complex geometries can be more easily constructed. The overlapping grid approach can also be used to remove coordinate singularities by, for example, covering a sphere with two or more patches. We describe the application of the overlapping grid approach to a variety of different problems. These include the solution of incompressible fluid flows with moving and deforming geometry, the solution of high-speed compressible reactive flow with rigid bodies using adaptive mesh refinement (AMR), and the solution of the time-domain Maxwell's equations of electromagnetism.

  16. Determination of overlap in lidar systems.

    PubMed

    Vande Hey, Joshua; Coupland, Jeremy; Foo, Ming Hui; Richards, James; Sandford, Andrew

    2011-10-20

    The overlap profile, also known as crossover function or geometric form factor, is often a source of uncertainty for lidar measurements. This paper describes a method for measuring the overlap by presenting the lidar with a virtual cloud through the use of an imaging system. Results show good agreement with horizontal hard target lidar measurements and with geometric overlap calculated for the ideal aberration-free case. PMID:22015406

  17. Overlap in Facebook Profiles Reflects Relationship Closeness.

    PubMed

    Castañeda, Araceli M; Wendel, Markie L; Crockett, Erin E

    2015-01-01

    We assessed the association between self-reported Inclusion of Other in the Self (IOS) and Facebook overlap. Ninety-two participants completed online measures of IOS and investment model constructs. Researchers then recorded Facebook data from participants' profile pages. Results from multilevel models revealed that IOS predicted Facebook overlap. Furthermore, Facebook overlap was associated with commitment and investment in ways comparable to self-reported IOS. These findings suggest that overlap in Facebook profiles can be used to measure relationship closeness. PMID:25635533

  18. Enzymatic assembly of overlapping DNA fragments.

    PubMed

    Gibson, Daniel G

    2011-01-01

    Three methods for assembling multiple, overlapping DNA molecules are described. Each method shares the same basic approach: (i) an exonuclease removes nucleotides from the ends of double-stranded (ds) DNA molecules, exposing complementary single-stranded (ss) DNA overhangs that are specifically annealed; (ii) the ssDNA gaps of the joined molecules are filled in by DNA polymerase, and the nicks are covalently sealed by DNA ligase. The first method employs the 3'-exonuclease activity of T4 DNA polymerase (T4 pol), Taq DNA polymerase (Taq pol), and Taq DNA ligase (Taq lig) in a two-step thermocycled reaction. The second method uses 3'-exonuclease III (ExoIII), antibody-bound Taq pol, and Taq lig in a one-step thermocycled reaction. The third method employs 5'-T5 exonuclease, Phusion® DNA polymerase, and Taq lig in a one-step isothermal reaction and can be used to assemble both ssDNA and dsDNA. These assembly methods can be used to seamlessly construct synthetic and natural genes, genetic pathways, and entire genomes and could be very useful for molecular engineering tools. PMID:21601685

  19. 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.

  20. Injection current dependences of electroluminescence transition energy in InGaN/GaN multiple quantum wells light emitting diodes under pulsed current conditions

    NASA Astrophysics Data System (ADS)

    Zhang, Feng; Ikeda, Masao; Zhou, Kun; Liu, Zongshun; Liu, Jianping; Zhang, Shuming; Yang, Hui

    2015-07-01

    Injection current dependences of electroluminescence transition energy in blue InGaN/GaN multiple quantum wells light emitting diodes (LEDs) with different quantum barrier thicknesses under pulsed current conditions have been analyzed taking into account the related effects including deformation caused by lattice strain, quantum confined Stark effects due to polarization field partly screened by carriers, band gap renormalization, Stokes-like shift due to compositional fluctuations which are supposed to be random alloy fluctuations in the sub-nanometer scale, band filling effect (Burstein-Moss shift), and quantum levels in finite triangular wells. The bandgap renormalization and band filling effect occurring at high concentrations oppose one another, however, the renormalization effect dominates in the concentration range studied, since the band filling effect arising from the filling in the tail states in the valence band of quantum wells is much smaller than the case in the bulk materials. In order to correlate the carrier densities with current densities, the nonradiative recombination rates were deduced experimentally by curve-fitting to the external quantum efficiencies. The transition energies in LEDs both with 15 nm quantum barriers and 5 nm quantum barriers, calculated using full strengths of theoretical macroscopic polarization given by Barnardini and Fiorentini [Phys. Status Solidi B 216, 391 (1999)] are in excellent accordance with experimental results. The LED with 5 nm barriers has been shown to exhibit a higher transition energy and a smaller blue shift than those of LED with 15 nm barriers, which is mainly caused by the smaller internal polarization field in the quantum wells.

  1. Injection current dependences of electroluminescence transition energy in InGaN/GaN multiple quantum wells light emitting diodes under pulsed current conditions

    SciTech Connect

    Zhang, Feng; Ikeda, Masao Liu, Jianping; Zhang, Shuming; Zhou, Kun; Yang, Hui; Liu, Zongshun

    2015-07-21

    Injection current dependences of electroluminescence transition energy in blue InGaN/GaN multiple quantum wells light emitting diodes (LEDs) with different quantum barrier thicknesses under pulsed current conditions have been analyzed taking into account the related effects including deformation caused by lattice strain, quantum confined Stark effects due to polarization field partly screened by carriers, band gap renormalization, Stokes-like shift due to compositional fluctuations which are supposed to be random alloy fluctuations in the sub-nanometer scale, band filling effect (Burstein-Moss shift), and quantum levels in finite triangular wells. The bandgap renormalization and band filling effect occurring at high concentrations oppose one another, however, the renormalization effect dominates in the concentration range studied, since the band filling effect arising from the filling in the tail states in the valence band of quantum wells is much smaller than the case in the bulk materials. In order to correlate the carrier densities with current densities, the nonradiative recombination rates were deduced experimentally by curve-fitting to the external quantum efficiencies. The transition energies in LEDs both with 15 nm quantum barriers and 5 nm quantum barriers, calculated using full strengths of theoretical macroscopic polarization given by Barnardini and Fiorentini [Phys. Status Solidi B 216, 391 (1999)] are in excellent accordance with experimental results. The LED with 5 nm barriers has been shown to exhibit a higher transition energy and a smaller blue shift than those of LED with 15 nm barriers, which is mainly caused by the smaller internal polarization field in the quantum wells.

  2. 47 CFR 73.509 - Prohibited overlap.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... operation would involve overlap of signal strength contours with any other station licensed by the... separation Contour of proposed station Contour of other station Co-channel 0.1mV/m (40 dBu)1 mV/m (60 dBu) 1... if the proposed operation would involve overlap of signal strength contours with any other station...

  3. 47 CFR 73.509 - Prohibited overlap.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... operation would involve overlap of signal strength contours with any other station licensed by the... separation Contour of proposed station Contour of other station Co-channel 0.1mV/m (40 dBu)1 mV/m (60 dBu) 1... if the proposed operation would involve overlap of signal strength contours with any other station...

  4. 47 CFR 73.509 - Prohibited overlap.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... operation would involve overlap of signal strength contours with any other station licensed by the... separation Contour of proposed station Contour of other station Co-channel 0.1mV/m (40 dBu)1 mV/m (60 dBu) 1... if the proposed operation would involve overlap of signal strength contours with any other station...

  5. 47 CFR 73.509 - Prohibited overlap.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... operation would involve overlap of signal strength contours with any other station licensed by the... separation Contour of proposed station Contour of other station Co-channel 0.1mV/m (40 dBu)1 mV/m (60 dBu) 1... if the proposed operation would involve overlap of signal strength contours with any other station...

  6. 47 CFR 73.509 - Prohibited overlap.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... operation would involve overlap of signal strength contours with any other station licensed by the... separation Contour of proposed station Contour of other station Co-channel 0.1mV/m (40 dBu)1 mV/m (60 dBu) 1... if the proposed operation would involve overlap of signal strength contours with any other station...

  7. Neural overlap in processing music and speech.

    PubMed

    Peretz, Isabelle; Vuvan, Dominique; Lagrois, Marie-Élaine; Armony, Jorge L

    2015-03-19

    Neural overlap in processing music and speech, as measured by the co-activation of brain regions in neuroimaging studies, may suggest that parts of the neural circuitries established for language may have been recycled during evolution for musicality, or vice versa that musicality served as a springboard for language emergence. Such a perspective has important implications for several topics of general interest besides evolutionary origins. For instance, neural overlap is an important premise for the possibility of music training to influence language acquisition and literacy. However, neural overlap in processing music and speech does not entail sharing neural circuitries. Neural separability between music and speech may occur in overlapping brain regions. In this paper, we review the evidence and outline the issues faced in interpreting such neural data, and argue that converging evidence from several methodologies is needed before neural overlap is taken as evidence of sharing. PMID:25646513

  8. Neural overlap in processing music and speech.

    PubMed

    Peretz, Isabelle; Vuvan, Dominique; Lagrois, Marie-Élaine; Armony, Jorge L

    2015-03-19

    Neural overlap in processing music and speech, as measured by the co-activation of brain regions in neuroimaging studies, may suggest that parts of the neural circuitries established for language may have been recycled during evolution for musicality, or vice versa that musicality served as a springboard for language emergence. Such a perspective has important implications for several topics of general interest besides evolutionary origins. For instance, neural overlap is an important premise for the possibility of music training to influence language acquisition and literacy. However, neural overlap in processing music and speech does not entail sharing neural circuitries. Neural separability between music and speech may occur in overlapping brain regions. In this paper, we review the evidence and outline the issues faced in interpreting such neural data, and argue that converging evidence from several methodologies is needed before neural overlap is taken as evidence of sharing.

  9. Motor Protein Accumulation on Antiparallel Microtubule Overlaps.

    PubMed

    Kuan, Hui-Shun; Betterton, Meredith D

    2016-05-10

    Biopolymers serve as one-dimensional tracks on which motor proteins move to perform their biological roles. Motor protein phenomena have inspired theoretical models of one-dimensional transport, crowding, and jamming. Experiments studying the motion of Xklp1 motors on reconstituted antiparallel microtubule overlaps demonstrated that motors recruited to the overlap walk toward the plus end of individual microtubules and frequently switch between filaments. We study a model of this system that couples the totally asymmetric simple exclusion process for motor motion with switches between antiparallel filaments and binding kinetics. We determine steady-state motor density profiles for fixed-length overlaps using exact and approximate solutions of the continuum differential equations and compare to kinetic Monte Carlo simulations. Overlap motor density profiles and motor trajectories resemble experimental measurements. The phase diagram of the model is similar to the single-filament case for low switching rate, while for high switching rate we find a new (to our knowledge) low density-high density-low density-high density phase. The overlap center region, far from the overlap ends, has a constant motor density as one would naïvely expect. However, rather than following a simple binding equilibrium, the center motor density depends on total overlap length, motor speed, and motor switching rate. The size of the crowded boundary layer near the overlap ends is also dependent on the overlap length and switching rate in addition to the motor speed and bulk concentration. The antiparallel microtubule overlap geometry may offer a previously unrecognized mechanism for biological regulation of protein concentration and consequent activity. PMID:27166811

  10. Overlap between empathy, teamwork and integrative approach to patient care.

    PubMed

    Hojat, Mohammadreza; Bianco, Joseph A; Mann, Douglas; Massello, David; Calabrese, Leonard H

    2014-10-14

    Abstract Background: Empathy, teamwork and an integrative approach to patient care share common denominators such as interpersonal skills and understanding patients' concerns. Thus, a significant overlap among measures of empathy, teamwork and integrative approach to patient care is expected. Aim: This study examined the magnitude of overlap (shared variance) among three measures of empathy, teamwork and an integrative approach to patient care. Methods: Three-hundred seventy-three medical students completed the Jefferson Scale of Empathy (JSE), the Jefferson Scale of Attitudes toward Physician-Nurse Collaboration (JSAPNC) and Integrative Patient Care (IPC). Results: Significant overlaps were found among the three measures (p < 0.01), ranging from 13% (r = 0.36), between JSAPNC and IPC, to 18% (r = 0.42), between JSE and JSAPNC, and 30% (r = 0.55) between JSE and IPC for the total sample. Pattern of findings was similar for men and women. In a multiple regression model, a significant multiple correlation (R = 0.60, p < 0.01) was obtained in correlating scores on the JSE with the JSAPNC, and IPC scores, controlling for gender effect (men = 0 and women = 1). Conclusions: The significant links between empathy, teamwork and IPC support the common denominator assumption. The findings that IPC shares common variance with empathy and teamwork have implications for medical education curriculum, suggesting that implementation of integrative patient care can improve empathic engagement in patient care and orientation toward teamwork.

  11. An experimental comparison of triggered and random pulse train uncertainties

    SciTech Connect

    Henzlova, Daniela; Menlove, Howard O; Swinhoe, Martyn T

    2010-01-01

    In this paper we present an experimental comparison of signal-triggered and randomly triggered based analysis algorithms of neutron multiplicity data. Traditional shift register type signal-triggered multiplicity analysis of singles, doubles and triples rates is compared with analysis using randomly triggered gates. Two methods of random gate generation are explored - non-overlapping gates (Feyrunan approach) and periodic overlapping gates (fast accidentals). Using californium sources with low, medium and high rate in combination with AmLi sources (as a surrogate for plutonium) we investigate relative standard deviation (RSD) of data in order to determine if there are parameter spaces in which one of the measurement methods should be preferred. Neutron correlation analysis is a commonly used NDA technique to assay plutonium mass. The data can be collected in two distinct ways: using signal-triggered or randomly triggered counting gates. Analysis algorithms were developed for both approaches to determine singles (S), doubles (D) and triples (7) rates from the measured sample. Currently the most commonly implemented technique to collect neutron coincidence data utilizes shift register based electronics. Shift register uses signal-triggered counting gates to generate foreground multiplicity distribution of correlated+accidental events and a random gate (opened after a predefined long delay following the signal trigger) to generate background multiplicity distribution of accidental events. Modern shift registers include fast accidental option to sample data with a fixed clock frequency. This way a set of overlapping gates is used to generate background multiplicity distributions in order to improve the measurement precision. In parallel to shift register approach the Feynman variance technique is frequently used, which utilizes set of consecutive non-overlapping gates. In general, different user communities (e.g. safeguards, nuclear material accountancy, emergency

  12. Estimation of triggered-lightning dart-stepped-leader currents from close multiple-station dE/dt pulse measurements

    NASA Astrophysics Data System (ADS)

    Gamerota, W. R.; Uman, M. A.; Hill, J. D.; Ngin, T.; Pilkey, J.; Jordan, D. M.

    2015-02-01

    The modified transmission line model is used to derive the vertically propagating leader-step currents necessary to radiate measured dart-stepped-leader dE/dt pulses from triggered lightning at close range (<400 m) and low altitude (<70 m). The model-predicted dE/dt pulses were compared with measured dE/dt pulses at nine locations ranging from 27 to 391 m from the channel base for four dE/dt pulses radiated from two triggered dart-stepped leaders. The dE/dt pulses at the closest station, 27 m, were unipolar, dominated by electrostatic and induction components of the radiated dE/dt, and of opposite polarity to the more distant initial dE/dt peaks. The other, more distant, eight stations exhibited bipolar dE/dt pulses, being more or less dominated by the dE/dt radiation component. The derived leader-step current has a slow front that precedes a fast transition to peak amplitude followed by a slow decay to zero after several microseconds. For the four modeled dE/dt pulses, the estimated causative leader-step current peak amplitudes varied from 0.9 to 1.8 kA, the half-peak widths ranged from 370 to 560 ns, the charge transfers were about 1 mC, and the peak current derivatives were about 10 kA/µs. The upward propagation speeds of the leader-step current were from 1.1 to 1.5 × 108 m/s with exponential spatial current decay constants from 13 to 27 m. One dE/dt pulse is analyzed in more detail by studying changes in model-predicted waveforms versus current initiation altitude and by examining the effect of varying model input parameters.

  13. Spectral-overlap approach to multiframe superresolution image reconstruction.

    PubMed

    Cohen, Edward; Picard, Richard H; Crabtree, Peter N

    2016-05-20

    Various techniques and algorithms have been developed to improve the resolution of sensor-aliased imagery captured with multiple subpixel-displaced frames on an undersampled pixelated image plane. These dealiasing algorithms are typically known as multiframe superresolution (SR), or geometric SR to emphasize the role of the focal-plane array. Multiple low-resolution (LR) aliased frames of the same scene are captured and allocated to a common high-resolution (HR) reconstruction grid, leading to the possibility of an alias-free reconstruction, as long as the HR sampling rate is above the Nyquist rate. Allocating LR-frame irradiances to HR frames requires the use of appropriate weights. Here we present a novel approach in the spectral domain to calculating exactly weights based on spatial overlap areas, which we call the spectral-overlap (SO) method. We emphasize that the SO method is not a spectral approach but rather an approach to calculating spatial weights that uses spectral decompositions to exploit the array properties of the HR and LR pixels. The method is capable of dealing with arbitrary aliasing factors and interframe motions consisting of in-plane translations and rotations. We calculate example reconstructed HR images (the inverse problem) from synthetic aliased images for integer and for fractional aliasing factors. We show the utility of the SO-generated overlap-area weights in both noniterative and iterative reconstructions with known or unknown aliasing factor. We show how the overlap weights can be used to generate the Green's function (pixel response function) for noniterative dealiasing. In addition, we show how the overlap-area weights can be used to generate synthetic aliased images (the forward problem). We compare the SO approach to the spatial-domain geometric approach of O'Rourke and find virtually identical high accuracy but with significant enhancements in speed for SO. We also compare the SO weights to interpolated weights and find that

  14. Infrared lidar overlap function: an experimental determination.

    PubMed

    Guerrero-Rascado, Juan Luis; Costa, Maria João; Bortoli, Daniele; Silva, Ana Maria; Lyamani, Hassan; Alados-Arboledas, Lucas

    2010-09-13

    The most recent works demonstrate that the lidar overlap function, which describes the overlap between the laser beam and the receiver field of view, can be determined experimentally for the 355 and 532 nm channels using Raman signals. Nevertheless, the Raman channels cannot be used to determine the lidar overlap for the infrared channel (1064 nm) because of their low intensity. In addition, many Raman lidar systems only provide inelastic signals with reasonable signal-to-noise ratio at nighttime. In view of this fact, this work presents a modification of that method, based on the comparison of attenuated backscatter profiles derived from lidar and ceilometer, to retrieve the overlap function for the lidar infrared channel. Similarly to the Raman overlap method, the approach presented here allows to derive the overlap correction without an explicit knowledge of all system parameters. The application of the proposed methodology will improve the potential of Raman lidars to investigate the aerosol microphysical properties in the planetary boundary layer, extending the information of 1064 nm backscatter profiles to the ground and allowing the retrieval of microphysical properties practically close to the surface.

  15. Segregated and overlapping neural circuits exist for the production of static and dynamic precision grip force.

    PubMed

    Neely, Kristina A; Coombes, Stephen A; Planetta, Peggy J; Vaillancourt, David E

    2013-03-01

    A central topic in sensorimotor neuroscience is the static-dynamic dichotomy that exists throughout the nervous system. Previous work examining motor unit synchronization reports that the activation strategy and timing of motor units differ for static and dynamic tasks. However, it remains unclear whether segregated or overlapping blood-oxygen-level-dependent (BOLD) activity exists in the brain for static and dynamic motor control. This study compared the neural circuits associated with the production of static force to those associated with the production of dynamic force pulses. To that end, healthy young adults (n = 17) completed static and dynamic precision grip force tasks during functional magnetic resonance imaging (fMRI). Both tasks activated core regions within the visuomotor network, including primary and sensory motor cortices, premotor cortices, multiple visual areas, putamen, and cerebellum. Static force was associated with unique activity in a right-lateralized cortical network including inferior parietal lobe, ventral premotor cortex, and dorsolateral prefrontal cortex. In contrast, dynamic force was associated with unique activity in left-lateralized and midline cortical regions, including supplementary motor area, superior parietal lobe, fusiform gyrus, and visual area V3. These findings provide the first neuroimaging evidence supporting a lateralized pattern of brain activity for the production of static and dynamic precision grip force.

  16. Micro-Pulse Lidar Signals: Uncertainty Analysis

    NASA Technical Reports Server (NTRS)

    Welton, Ellsworth J.; Campbell, James R.; Starr, David OC. (Technical Monitor)

    2002-01-01

    Micro-pulse lidar (MPL) systems are small, autonomous, eye-safe lidars used for continuous observations of the vertical distribution of cloud and aerosol layers. Since the construction of the first MPL in 1993, procedures have been developed to correct for various instrument effects present in MPL signals. The primary instrument effects include afterpulse, laser-detector cross-talk, and overlap, poor near-range (less than 6 km) focusing. The accurate correction of both afterpulse and overlap effects are required to study both clouds and aerosols. Furthermore, the outgoing energy of the laser pulses and the statistical uncertainty of the MPL detector must also be correctly determined in order to assess the accuracy of MPL observations. The uncertainties associated with the afterpulse, overlap, pulse energy, detector noise, and all remaining quantities affecting measured MPL signals, are determined in this study. The uncertainties are propagated through the entire MPL correction process to give a net uncertainty on the final corrected MPL signal. The results show that in the near range, the overlap uncertainty dominates. At altitudes above the overlap region, the dominant source of uncertainty is caused by uncertainty in the pulse energy. However, if the laser energy is low, then during mid-day, high solar background levels can significantly reduce the signal-to-noise of the detector. In such a case, the statistical uncertainty of the detector count rate becomes dominant at altitudes above the overlap region.

  17. Sensitivity enhancement of the central-transition signal of half-integer spin quadrupolar nuclei in solid-state NMR: Features of multiple fast amplitude-modulated pulse transfer

    NASA Astrophysics Data System (ADS)

    Goswami, Mithun; Madhu, P. K.

    2008-06-01

    Sensitivity enhancement of solid-state NMR spectrum of half-integer spin quadrupolar nuclei under both magic-angle spinning (MAS) and static cases has been demonstrated by transferring polarisation associated with satellite transitions to the central m = -1/2 → 1/2 transition with suitably modulated radio-frequency pulse schemes. It has been shown that after the application of such enhancement schemes, there still remains polarisation in the satellite transitions that can be transferred to the central transition. This polarisation is available without having to wait for the spin system to return to thermal equilibrium. We demonstrate here the additional sensitivity enhancement obtained by making use of this remaining polarisation with fast amplitude-modulated (FAM) pulse schemes under both MAS and static conditions on a spin-3/2 and a spin-5/2 system. Considerable signal enhancement is obtained with the application of the multiple FAM sequence, denoted as m-FAM. We also report here some of the salient features of these multiple FAM sequences with respect to the nutation frequency of the pulses and the spinning frequency.

  18. Cooperative pulses

    NASA Astrophysics Data System (ADS)

    Braun, Michael; Glaser, Steffen J.

    2010-11-01

    We introduce the concept of cooperative (COOP) pulses which are designed to compensate each other's imperfections. In multi-scan experiments, COOP pulses can cancel undesired signal contributions, complementing and generalizing phase cycles. COOP pulses can be efficiently optimized using an extended version of the optimal-control-based gradient ascent pulse engineering (GRAPE) algorithm. The advantage of the COOP approach is experimentally demonstrated for broadband and band-selective pulses.

  19. Impact of overlapping resonances on magnetoassociation of cold molecules in tight traps

    NASA Astrophysics Data System (ADS)

    Jachymski, Krzysztof

    2016-10-01

    Overlapping Feshbach resonances are commonly observed in experiments with ultracold atoms and can influence the molecule production process. We derive an effective approach to describe magnetoassociation in an external trap in the presence of multiple overlapping resonances. We study how the strength and shape of the trap affects the energy level structure and demonstrate the existence of a regime in which the conventional two-channel Landau-Zener description of the molecule production process breaks down.

  20. Overlapping genetic codes for overlapping frameshifted genes in Testudines, and Lepidochelys olivacea as special case.

    PubMed

    Seligmann, Hervé

    2012-12-01

    Mitochondrial genes code for additional proteins after +2 frameshifts by reassigning stops to code for amino acids, which defines overlapping genetic codes for overlapping genes. Turtles recode stops UAR → Trp and AGR → Lys (AGR → Gly in the marine Olive Ridley turtle, Lepidochelys olivacea). In Lepidochelys the +2 frameshifted mitochondrial Cytb gene lacks stops, open reading frames from other genes code for unknown proteins, and for regular mitochondrial proteins after frameshifts according to the overlapping genetic code. Lepidochelys' inversion between proteins coded by regular and overlapping genetic codes substantiates the existence of overlap coding. ND4 differs among Lepidochelys mitochondrial genomes: it is regular in DQ486893; in NC_011516, the open reading frame codes for another protein, the regular ND4 protein is coded by the frameshifted sequence reassigning stops as in other turtles. These systematic patterns are incompatible with Genbank/sequencing errors and DNA decay. Random mixing of synonymous codons, conserving main frame coding properties, shows optimization of natural sequences for overlap coding; Ka/Ks analyses show high positive (directional) selection on overlapping genes. Tests based on circular genetic codes confirm programmed frameshifts in ND3 and ND4l genes, and predicted frameshift sites for overlap coding in Lepidochelys. Chelonian mitochondria adapt for overlapping gene expression: cloverleaf formation by antisense tRNAs with predicted anticodons matching stops coevolves with overlap coding; antisense tRNAs with predicted expanded anticodons (frameshift suppressor tRNAs) associate with frameshift-coding in ND3 and ND4l, a potential regulation of frameshifted overlap coding. Anaeroby perhaps switched between regular and overlap coding genes in Lepidochelys.

  1. Abnormal Policy Detection and Correction Using Overlapping Transition

    NASA Astrophysics Data System (ADS)

    Kim, Sunghyun; Lee, Heejo

    Policy in security devices such as firewalls and Network Intrusion Prevention Systems (NIPS) is usually implemented as a sequence of rules. This allows network packets to proceed or to be discarded based on rule's decision. Since attack methods are increasing rapidly, a huge number of security rules are generated and maintained in security devices. Under attack or during heavy traffic, the policy configured wrong creates security holes and prevents the system from deciding quickly whether to allow or deny a packet. Anomalies between the rules occur when there is overlap among the rules. In this paper, we propose a new method to detect anomalies among rules and generate new rules without configuration error in multiple security devices as well as in a single security device. The proposed method cuts the overlap regions among rules into minimum overlap regions and finds the abnormal domain regions of rules' predicates. Classifying rules by the network traffic flow, the proposed method not only reduces computation overhead but blocks unnecessary traffic among distributed devices.

  2. A Stochastic Model for Detecting Overlapping and Hierarchical Community Structure

    PubMed Central

    Cao, Xiaochun; Wang, Xiao; Jin, Di; Guo, Xiaojie; Tang, Xianchao

    2015-01-01

    Community detection is a fundamental problem in the analysis of complex networks. Recently, many researchers have concentrated on the detection of overlapping communities, where a vertex may belong to more than one community. However, most current methods require the number (or the size) of the communities as a priori information, which is usually unavailable in real-world networks. Thus, a practical algorithm should not only find the overlapping community structure, but also automatically determine the number of communities. Furthermore, it is preferable if this method is able to reveal the hierarchical structure of networks as well. In this work, we firstly propose a generative model that employs a nonnegative matrix factorization (NMF) formulization with a l2,1 norm regularization term, balanced by a resolution parameter. The NMF has the nature that provides overlapping community structure by assigning soft membership variables to each vertex; the l2,1 regularization term is a technique of group sparsity which can automatically determine the number of communities by penalizing too many nonempty communities; and hence the resolution parameter enables us to explore the hierarchical structure of networks. Thereafter, we derive the multiplicative update rule to learn the model parameters, and offer the proof of its correctness. Finally, we test our approach on a variety of synthetic and real-world networks, and compare it with some state-of-the-art algorithms. The results validate the superior performance of our new method. PMID:25822148

  3. Automatic segmentation of overlapping and touching chromosomes

    NASA Astrophysics Data System (ADS)

    Yuan, Zhiqiang; Chen, Xiaohua; Zhang, Renli; Yu, Chang

    2001-09-01

    This paper describes a technique to segment overlapping and touching chromosomes of human metaphase cells. Automated chromosome classification has been an important pattern recognition problem for decades, numerous attempts were made in the past to characterize chromosome band patterns. But successful separation between touching and overlapping chromosomes is vital for correct classification. Since chromosomes are non-rigid objects, common methods for separation between touching chromosomes are not usable. We proposed a method using shape concave and convex information, topology analysis information, and band pale paths for segmentation of touching and overlapping chromosomes. To detect shape concave and convex information, we should first pre-segment the chromosomes and get the edge of overlapping and touching chromosomes. After filtering the original image using edge-preserving filter, we adopt the Otsu's segmentation method and extract the boundary of chromosomes. Hence the boundary can be used for segment the overlapping and touching chromosomes by detecting the concave and convex information based on boundary information. Most of the traditional boundary-based algorithms detect corners based on two steps: the first step is to acquire the smoothed version of curvature at every point along the contour, and the second step is to detect the positions where curvature maximal occur and threshold the curvature as corner points. Recently wavelet transform has been adopted into corner detection algorithms. Since the metaphase overlapping chromosomes has multi-scale corners, we adopt a multi-scale corner detection method based on Hua's method for corner detection. For touching chromosomes, it is convenient to split them using pale paths. Starting from concave corner points, a search algorithm is represented. The searching algorithm traces three pixels into the object in the direction of the normal vector in order to avoid stopping at the initial boundary until it

  4. Analysis of noise barrier overlap gaps

    NASA Astrophysics Data System (ADS)

    Herman, Lloyd A.; Clum, Craig M.

    2002-04-01

    Sound propagation through the gap produced by two parallel vertical barriers with overlapped ends is formulated for traffic noise sources. The analysis identifies both source and receiver regions according to the mechanisms that influence noise propagation in the vicinity of an overlap gap. A method to account for the contributions from the various source regions for a given receiver location is described. The derived method can be implemented using various equations for sound propagation. The results of using equations approved by the United States Federal Highway Administration for traffic noise propagation are given. Uncalibrated predictions are compared with field measurements for up to 30 receiver positions from each of four overlap gaps. The relative importance of contributions from reflected rays to the noise levels at receiver positions is given. The analysis confirms the initial hypothesis that a commonly used strategy of overlapping barriers by an amount equal to two or three times the overlap width is useful for controlling line-of-sight propagation but ignores the substantial effect of reflections.

  5. Adaptive Estimation with Partially Overlapping Models

    PubMed Central

    Shin, Sunyoung; Fine, Jason; Liu, Yufeng

    2015-01-01

    In many problems, one has several models of interest that capture key parameters describing the distribution of the data. Partially overlapping models are taken as models in which at least one covariate effect is common to the models. A priori knowledge of such structure enables efficient estimation of all model parameters. However, in practice, this structure may be unknown. We propose adaptive composite M-estimation (ACME) for partially overlapping models using a composite loss function, which is a linear combination of loss functions defining the individual models. Penalization is applied to pairwise differences of parameters across models, resulting in data driven identification of the overlap structure. Further penalization is imposed on the individual parameters, enabling sparse estimation in the regression setting. The recovery of the overlap structure enables more efficient parameter estimation. An oracle result is established. Simulation studies illustrate the advantages of ACME over existing methods that fit individual models separately or make strong a priori assumption about the overlap structure. PMID:26917931

  6. Stochastic Maximum Likelihood (SML) parametric estimation of overlapped Doppler echoes

    NASA Astrophysics Data System (ADS)

    Boyer, E.; Petitdidier, M.; Larzabal, P.

    2004-11-01

    This paper investigates the area of overlapped echo data processing. In such cases, classical methods, such as Fourier-like techniques or pulse pair methods, fail to estimate the first three spectral moments of the echoes because of their lack of resolution. A promising method, based on a modelization of the covariance matrix of the time series and on a Stochastic Maximum Likelihood (SML) estimation of the parameters of interest, has been recently introduced in literature. This method has been tested on simulations and on few spectra from actual data but no exhaustive investigation of the SML algorithm has been conducted on actual data: this paper fills this gap. The radar data came from the thunderstorm campaign that took place at the National Astronomy and Ionospheric Center (NAIC) in Arecibo, Puerto Rico, in 1998.

  7. Coherent propagation of a single photon in a lossless medium: 0π pulse formation, storage, and retrieval in multiple temporal modes

    NASA Astrophysics Data System (ADS)

    Petrosyan, Sh.; Malakyan, Yu.

    2013-12-01

    Single-photon coherent optics represents a fundamental importance for the investigation of quantum light-matter interactions. While most work has considered the interaction in the steady-state regime, here we demonstrate that a single-photon pulse shorter than any relaxation time in a medium propagates without energy loss and is consistently transformed into a zero-area pulse. A general analytical solution is found for photon passage through a cold ensemble of Λ-type atoms confined inside a hollow core of a single-mode photonic-crystal fiber. We use the robust far-off-resonant Raman scheme to control the pulse reshaping by an intense control laser beam and show that in the case of cw control field, for exact two-photon resonance, the outgoing photon displays an oscillating temporal distribution, which is the quantum counterpart of a classical field ringing, while for nonzero two-photon detuning a slow photon is produced. We demonstrate also that a train of readout control pulses coherently recalls the stored photon in many well-separated temporal modes, thus producing time-bin entangled single-photon states. Such states, which allow sharing quantum information among many users, are highly demanded for applications in long-distance quantum communication.

  8. 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.

  9. Phonon Overlaps in Molecular Quantum Dot Systems

    NASA Astrophysics Data System (ADS)

    Chang, Connie; Sethna, James

    2004-03-01

    We model the amplitudes and frequencies of the vibrational sidebands for the new molecular quantum dot systems. We calculate the Franck-Condon phonon overlaps in the 3N-dimensional configuration sapce. We solve the general case where the vibrational frequencies and eigenmodes change during the transition. We perform PM3 and DFT calculations for the case of the dumb bell-shaped C140 molecule. We find that the strongest amplitudes are associated with the 11 meV stretch mode, in agreement with experiment. The experimental amplitudes vary from molecule to molecule; indicating that the molecular overlaps are environment dependent. We explore overlaps in the presence of external electric fields from image charges and counter ions.

  10. Generating Composite Overlapping Grids on CAD Geometries

    SciTech Connect

    Henshaw, W.D.

    2002-02-07

    We describe some algorithms and tools that have been developed to generate composite overlapping grids on geometries that have been defined with computer aided design (CAD) programs. This process consists of five main steps. Starting from a description of the surfaces defining the computational domain we (1) correct errors in the CAD representation, (2) determine topology of the patched-surface, (3) build a global triangulation of the surface, (4) construct structured surface and volume grids using hyperbolic grid generation, and (5) generate the overlapping grid by determining the holes and the interpolation points. The overlapping grid generator which is used for the final step also supports the rapid generation of grids for block-structured adaptive mesh refinement and for moving grids. These algorithms have been implemented as part of the Overture object-oriented framework.

  11. Sub-Plate Overlap Code Documentation

    NASA Technical Reports Server (NTRS)

    Taff, L. G.; Bucciarelli, B.; Zarate, N.

    1997-01-01

    An expansion of the plate overlap method of astrometric data reduction to a single plate has been proposed and successfully tested. Each plate is (artificially) divided into sub-plates which can then be overlapped. This reduces the area of a 'plate' over which a plate model needs to accurately represent the relationship between measured coordinates and standard coordinates. Application is made to non-astrographic plates such as Schmidt plates and to wide-field astrographic plates. Indeed, the method is completely general and can be applied to any type of recording media.

  12. Pulse Oximetry

    MedlinePlus

    ... www.thoracic.org amount of gases (oxygen and carbon dioxide) that are in your blood. To get an ... Also, a pulse oximeter does not measure your carbon dioxide level. How accurate is the pulse oximeter? The ...

  13. Reflection positivity of free overlap fermions

    SciTech Connect

    Kikukawa, Yoshio; Usui, Kouta

    2010-12-01

    It is shown that free lattice fermions defined by overlap Dirac operator fulfill the Osterwalder-Schrader reflection positivity condition with respect to the link-reflection. The proof holds true in nongauge models with interactions such as chiral Yukawa models.

  14. Autism and ADHD: Overlapping and Discriminating Symptoms

    ERIC Educational Resources Information Center

    Mayes, Susan Dickerson; Calhoun, Susan L.; Mayes, Rebecca D.; Molitoris, Sarah

    2012-01-01

    Children with ADHD and autism have some similar features, complicating a differential diagnosis. The purpose of our study was to determine the degree to which core ADHD and autistic symptoms overlap in and discriminate between children 2-16 years of age with autism and ADHD. Our study demonstrated that 847 children with autism were easily…

  15. Overlapping Community Detection based on Network Decomposition.

    PubMed

    Ding, Zhuanlian; Zhang, Xingyi; Sun, Dengdi; Luo, Bin

    2016-01-01

    Community detection in complex network has become a vital step to understand the structure and dynamics of networks in various fields. However, traditional node clustering and relatively new proposed link clustering methods have inherent drawbacks to discover overlapping communities. Node clustering is inadequate to capture the pervasive overlaps, while link clustering is often criticized due to the high computational cost and ambiguous definition of communities. So, overlapping community detection is still a formidable challenge. In this work, we propose a new overlapping community detection algorithm based on network decomposition, called NDOCD. Specifically, NDOCD iteratively splits the network by removing all links in derived link communities, which are identified by utilizing node clustering technique. The network decomposition contributes to reducing the computation time and noise link elimination conduces to improving the quality of obtained communities. Besides, we employ node clustering technique rather than link similarity measure to discover link communities, thus NDOCD avoids an ambiguous definition of community and becomes less time-consuming. We test our approach on both synthetic and real-world networks. Results demonstrate the superior performance of our approach both in computation time and accuracy compared to state-of-the-art algorithms. PMID:27066904

  16. Overlapping Community Detection based on Network Decomposition

    NASA Astrophysics Data System (ADS)

    Ding, Zhuanlian; Zhang, Xingyi; Sun, Dengdi; Luo, Bin

    2016-04-01

    Community detection in complex network has become a vital step to understand the structure and dynamics of networks in various fields. However, traditional node clustering and relatively new proposed link clustering methods have inherent drawbacks to discover overlapping communities. Node clustering is inadequate to capture the pervasive overlaps, while link clustering is often criticized due to the high computational cost and ambiguous definition of communities. So, overlapping community detection is still a formidable challenge. In this work, we propose a new overlapping community detection algorithm based on network decomposition, called NDOCD. Specifically, NDOCD iteratively splits the network by removing all links in derived link communities, which are identified by utilizing node clustering technique. The network decomposition contributes to reducing the computation time and noise link elimination conduces to improving the quality of obtained communities. Besides, we employ node clustering technique rather than link similarity measure to discover link communities, thus NDOCD avoids an ambiguous definition of community and becomes less time-consuming. We test our approach on both synthetic and real-world networks. Results demonstrate the superior performance of our approach both in computation time and accuracy compared to state-of-the-art algorithms.

  17. Liberal Education: An Overlapping Pragmatic Consensus.

    ERIC Educational Resources Information Center

    Paris, David C.; Kimball, Bruce A.

    2000-01-01

    Suggests in Bruce Kimball's thesis that a pragmatic consensus was emerging about the understanding of liberal education offers that it might be best understood by comparing it to J. Rawl's idea of an "overlapping consensus." States that by comparing and contrasting these ideas that the emerging consensus is pragmatic in nature. (CMK)

  18. Overlapping Community Detection based on Network Decomposition

    PubMed Central

    Ding, Zhuanlian; Zhang, Xingyi; Sun, Dengdi; Luo, Bin

    2016-01-01

    Community detection in complex network has become a vital step to understand the structure and dynamics of networks in various fields. However, traditional node clustering and relatively new proposed link clustering methods have inherent drawbacks to discover overlapping communities. Node clustering is inadequate to capture the pervasive overlaps, while link clustering is often criticized due to the high computational cost and ambiguous definition of communities. So, overlapping community detection is still a formidable challenge. In this work, we propose a new overlapping community detection algorithm based on network decomposition, called NDOCD. Specifically, NDOCD iteratively splits the network by removing all links in derived link communities, which are identified by utilizing node clustering technique. The network decomposition contributes to reducing the computation time and noise link elimination conduces to improving the quality of obtained communities. Besides, we employ node clustering technique rather than link similarity measure to discover link communities, thus NDOCD avoids an ambiguous definition of community and becomes less time-consuming. We test our approach on both synthetic and real-world networks. Results demonstrate the superior performance of our approach both in computation time and accuracy compared to state-of-the-art algorithms. PMID:27066904

  19. PARALYZER FOR PULSE HEIGHT DISTRIBUTION ANALYZER

    DOEpatents

    Fairstein, E.

    1960-01-19

    A paralyzer circuit is described for use with a pulseheight distribution analyzer to prevent the analyzer from counting overlapping pulses where they would serve to provide a false indication. The paralyzer circuit comprises a pair of cathode-coupled amplifiers for amplifying pulses of opposite polarity. Diodes are provided having their anodes coupled to the separate outputs of the amplifiers to produce only positive signals, and a trigger circuit is coupled to the diodes ior operation by input pulses of either polarity from the amplifiers. A delay network couples the output of the trigger circuit for delaying the pulses.

  20. Measuring extremely complex pulses with time-bandwidth products exceeding 65,000 using multiple-delay crossed-beam spectral interferometry.

    PubMed

    Cohen, Jacob; Bowlan, Pamela; Chauhan, Vikrant; Vaughan, Peter; Trebino, Rick

    2010-11-22

    We measure the complete electric field of extremely complex ultrafast waveforms using the simple linear-optical, interferometric pulse-measurement technique, MUD TADPOLE. The waveforms were measured with ~40 fs temporal resolution over a temporal range of ~3.5 ns and had time-bandwidth products exceeding 65,000. The approach is general and could allow the measurement of arbitrary optical waveforms.

  1. Toxicokinetic-toxicodynamic modelling of survival of Gammarus pulex in multiple pulse exposures to propiconazole: model assumptions, calibration data requirements and predictive power.

    PubMed

    Nyman, Anna-Maija; Schirmer, Kristin; Ashauer, Roman

    2012-10-01

    Toxicokinetic-toxicodynamic (TKTD) models quantify the time-course of internal concentration, which is defined by uptake, elimination and biotransformation (TK), and the processes which lead to the toxic effects (TD). TKTD models show potential in predicting pesticide effects in fluctuating concentrations, but the data requirements and validity of underlying model assumptions are not known. We calibrated TKTD models to predict survival of Gammarus pulex in propiconazole exposure and investigated the data requirements. In order to assess the need of TK in survival models, we included or excluded simulated internal concentrations based on pre-calibrated TK. Adding TK did not improve goodness of fits. Moreover, different types of calibration data could be used to model survival, which might affect model parameterization. We used two types of data for calibration: acute toxicity (standard LC50, 4 d) or pulsed toxicity data (total length 10 d). The calibration data set influenced how well the survival in the other exposure scenario was predicted (acute to pulsed scenario or vice versa). We also tested two contrasting assumptions in ecotoxicology: stochastic death and individual tolerance distribution. Neither assumption fitted to data better than the other. We observed in 10-d toxicity experiments that pulsed treatments killed more organisms than treatments with constant concentration. All treatments received the same dose, i.e. the time-weighted average concentration was equal. We studied mode of toxic action of propiconazole and it likely acts as a baseline toxicant in G. pulex during 10-days of exposure for the endpoint survival.

  2. Measures for the degree of overlap of gene signatures and applications to TCGA

    PubMed Central

    Shi, Xingjie; Yi, Huangdi

    2015-01-01

    For cancer and many other complex diseases, a large number of gene signatures have been generated. In this study, we use cancer as an example and note that other diseases can be analyzed in a similar manner. For signatures generated in multiple independent studies on the same cancer type and outcome, and for signatures on different cancer types, it is of interest to evaluate their degree of overlap. Many of the existing studies simply count the number (or percentage) of overlapped genes shared by two signatures. Such an approach has serious limitations. In this study, as a demonstrating example, we consider cancer prognosis data under the Cox model. Lasso, which is representative of a large number of regularization methods, is adopted for generating gene signatures. We examine two families of measures for quantifying the degree of overlap. The first family is based on the Cox-Lasso estimates at the optimal tunings, and the second family is based on estimates across the whole solution paths. Within each family, multiple measures, which describe the overlap from different perspectives, are introduced. The analysis of TCGA (The Cancer Genome Atlas) data on five cancer types shows that the degree of overlap varies across measures, cancer types and types of (epi)genetic measurements. More investigations are needed to better describe and understand the overlaps among gene signatures. PMID:25552438

  3. On the radiative properties of soot aggregates part 1: Necking and overlapping

    NASA Astrophysics Data System (ADS)

    Yon, J.; Bescond, A.; Liu, F.

    2015-09-01

    There is a strong interest in accurately modelling the radiative properties of soot aggregates (also known as black carbon particles) emitted from combustion systems and fires to gain improved understanding of the role of black carbon to global warming. This study conducted a systematic investigation of the effects of overlapping and necking between neighbouring primary particles on the radiative properties of soot aggregates using the discrete dipole approximation. The degrees of overlapping and necking are quantified by the overlapping and necking parameters. Realistic soot aggregates were generated numerically by constructing overlapping and necking to fractal aggregates formed by point-touch primary particles simulated using a diffusion-limited cluster aggregation algorithm. Radiative properties (differential scattering, absorption, total scattering, specific extinction, asymmetry factor and single scattering albedo) were calculated using the experimentally measured soot refractive index over the spectral range of 266-1064 nm for 9 combinations of the overlapping and necking parameters. Overlapping and necking affect significantly the absorption and scattering properties of soot aggregates, especially in the near UV spectrum due to the enhanced multiple scattering effects within an aggregate. By using correctly modified aggregate properties (fractal dimension, prefactor, primary particle radius, and the number of primary particle) and by accounting for the effects of multiple scattering, the simple Rayleigh-Debye-Gans theory for fractal aggregates can reproduce reasonably accurate radiative properties of realistic soot aggregates.

  4. Optimized spatial overlap in optical pump-X-ray probe experiments with high repetition rate using laser-induced surface distortions.

    PubMed

    Reinhardt, Matthias; Koc, Azize; Leitenberger, Wolfram; Gaal, Peter; Bargheer, Matias

    2016-03-01

    Ultrafast X-ray diffraction experiments require careful adjustment of the spatial overlap between the optical excitation and the X-ray probe pulse. This is especially challenging at high laser repetition rates. Sample distortions caused by the large heat load on the sample and the relatively low optical energy per pulse lead to only tiny signal changes. In consequence, this results in small footprints of the optical excitation on the sample, which turns the adjustment of the overlap difficult. Here a method for reliable overlap adjustment based on reciprocal space mapping of a laser excited thin film is presented. PMID:26917135

  5. Optimized spatial overlap in optical pump-X-ray probe experiments with high repetition rate using laser-induced surface distortions.

    PubMed

    Reinhardt, Matthias; Koc, Azize; Leitenberger, Wolfram; Gaal, Peter; Bargheer, Matias

    2016-03-01

    Ultrafast X-ray diffraction experiments require careful adjustment of the spatial overlap between the optical excitation and the X-ray probe pulse. This is especially challenging at high laser repetition rates. Sample distortions caused by the large heat load on the sample and the relatively low optical energy per pulse lead to only tiny signal changes. In consequence, this results in small footprints of the optical excitation on the sample, which turns the adjustment of the overlap difficult. Here a method for reliable overlap adjustment based on reciprocal space mapping of a laser excited thin film is presented.

  6. PULSE GENERATOR

    DOEpatents

    Roeschke, C.W.

    1957-09-24

    An improvement in pulse generators is described by which there are produced pulses of a duration from about 1 to 10 microseconds with a truly flat top and extremely rapid rise and fall. The pulses are produced by triggering from a separate input or by modifying the current to operate as a free-running pulse generator. In its broad aspect, the disclosed pulse generator comprises a first tube with an anode capacitor and grid circuit which controls the firing; a second tube series connected in the cathode circuit of the first tube such that discharge of the first tube places a voltage across it as the leading edge of the desired pulse; and an integrator circuit from the plate across the grid of the second tube to control the discharge time of the second tube, determining the pulse length.

  7. The Functional Overlap of Executive Control and Language Processing in Bilinguals

    PubMed Central

    Coderre, Emily L.; Smith, Jason F.; van Heuven, Walter J.B.; Horwitz, Barry

    2016-01-01

    The need to control multiple languages is thought to require domain-general executive control (EC) in bilinguals such that the EC and language systems become interdependent. However, there has been no systematic investigation into how and where EC and language processes overlap in the bilingual brain. If the concurrent recruitment of EC during bilingual language processing is domain-general and extends to non-linguistic EC, we hypothesize that regions commonly involvement in language processing, linguistic EC, and non-linguistic EC may be selectively altered in bilinguals compared to monolinguals. A conjunction of functional magnetic resonance imaging (fMRI) data from a flanker task with linguistic and nonlinguistic distractors and a semantic categorization task showed functional overlap in the left inferior frontal gyrus (LIFG) in bilinguals, whereas no overlap occurred in monolinguals. This research therefore identifies a neural locus of functional overlap of language and EC in the bilingual brain. PMID:27695385

  8. The Functional Overlap of Executive Control and Language Processing in Bilinguals

    PubMed Central

    Coderre, Emily L.; Smith, Jason F.; van Heuven, Walter J.B.; Horwitz, Barry

    2016-01-01

    The need to control multiple languages is thought to require domain-general executive control (EC) in bilinguals such that the EC and language systems become interdependent. However, there has been no systematic investigation into how and where EC and language processes overlap in the bilingual brain. If the concurrent recruitment of EC during bilingual language processing is domain-general and extends to non-linguistic EC, we hypothesize that regions commonly involvement in language processing, linguistic EC, and non-linguistic EC may be selectively altered in bilinguals compared to monolinguals. A conjunction of functional magnetic resonance imaging (fMRI) data from a flanker task with linguistic and nonlinguistic distractors and a semantic categorization task showed functional overlap in the left inferior frontal gyrus (LIFG) in bilinguals, whereas no overlap occurred in monolinguals. This research therefore identifies a neural locus of functional overlap of language and EC in the bilingual brain.

  9. Design and Performance of Overlap FFT Filter-Bank for Dynamic Spectrum Access Applications

    NASA Astrophysics Data System (ADS)

    Tanabe, Motohiro; Umehira, Masahiro

    An OFDMA-based (Orthogonal Frequency Division Multiple Access-based) channel access scheme for dynamic spectrum access has the drawbacks of large PAPR (Peak to Average Power Ratio) and large ACI (Adjacent Channel Interference). To solve these problems, a flexible channel access scheme using an overlap FFT filter-bank was proposed based on single carrier modulation for dynamic spectrum access. In order to apply the overlap FFT filter-bank for dynamic spectrum access, it is necessary to clarify the performance of the overlap FFT filter-bank according to the design parameters since its frequency characteristics are critical for dynamic spectrum access applications. This paper analyzes the overlap FFT filter-bank and evaluates its performance such as frequency characteristics and ACI performance according to the design parameters.

  10. Lectures on pulsed NMR

    SciTech Connect

    Pines, A.

    1986-09-01

    These lectures discuss some recent developments in pulsed NMR, emphasizing fundamental principles with selected illustrative applications. Major topics covered include multiple-quantum spectroscopy, spin decoupling, the interaction of spins with a quantized field, adiabatic rapid passage, spin temperature and statistics of cross-polarization, coherent averaging, and zero field NMR. 55 figs.

  11. Lectures on pulsed NMR

    SciTech Connect

    Pines, A.

    1988-08-01

    These lectures discuss some recent developments in pulsed NMR, emphasizing fundamental principles with selected illustrative applications. Major topics covered include multiple-quantum spectroscopy, spin decoupling, the interaction of spins with a quantized field, adiabatic rapid passage, spin temperature and statistics of cross-polarization, coherent averaging, and zero field NMR. 32 refs., 56 figs.

  12. Measuring complex pulses with time-bandwidth products exceeding 65,000 using multiple-delay crossed-beam spectral interferometry

    NASA Astrophysics Data System (ADS)

    Cohen, Jacob; Bowlan, Pamela; Chauhan, Vikrant; Vaughan, Peter; Trebino, Rick

    2011-03-01

    We measure the complete electric field of extremely complex ultrafast waveforms using the simple linear-optical, interferometric pulse-measurement technique, MUD TADPOLE. In its scanning variation, we measured waveforms with time-bandwidth products exceeding 65,000 with ~40 fs temporal resolution over a temporal range of ~3.5ns. In the single-shot variation we measured complex waveforms time-bandwidth products exceeding 65,000. The approach is general and could allow the measurement of arbitrary optical waveforms.

  13. Automated Deconvolution of Overlapped Ion Mobility Profiles

    NASA Astrophysics Data System (ADS)

    Brantley, Matthew; Zekavat, Behrooz; Harper, Brett; Mason, Rachel; Solouki, Touradj

    2014-10-01

    Presence of unresolved ion mobility (IM) profiles limits the efficient utilization of IM mass spectrometry (IM-MS) systems for isomer differentiation. Here, we introduce an automated ion mobility deconvolution (AIMD) computer software for streamlined deconvolution of overlapped IM-MS profiles. AIMD is based on a previously reported post-IM/collision-induced dissociation (CID) deconvolution approach [ J. Am. Soc. Mass Spectrom. 23, 1873 (2012)] and, unlike the previously reported manual approach, it does not require resampling of post-IM/CID data. A novel data preprocessing approach is utilized to improve the accuracy and efficiency of the deconvolution process. Results from AIMD analysis of overlapped IM profiles of data from (1) Waters Synapt G1 for a binary mixture of isomeric peptides (amino acid sequences: GRGDS and SDGRG) and (2) Waters Synapt G2-S for a binary mixture of isomeric trisaccharides (raffinose and isomaltotriose) are presented.

  14. Burnout-depression overlap: a review.

    PubMed

    Bianchi, Renzo; Schonfeld, Irvin Sam; Laurent, Eric

    2015-03-01

    Whether burnout is a form of depression or a distinct phenomenon is an object of controversy. The aim of the present article was to provide an up-to-date review of the literature dedicated to the question of burnout-depression overlap. A systematic literature search was carried out in PubMed, PsycINFO, and IngentaConnect. A total of 92 studies were identified as informing the issue of burnout-depression overlap. The current state of the art suggests that the distinction between burnout and depression is conceptually fragile. It is notably unclear how the state of burnout (i.e., the end stage of the burnout process) is conceived to differ from clinical depression. Empirically, evidence for the distinctiveness of the burnout phenomenon has been inconsistent, with the most recent studies casting doubt on that distinctiveness. The absence of consensual diagnostic criteria for burnout and burnout research's insufficient consideration of the heterogeneity of depressive disorders constitute major obstacles to the resolution of the raised issue. In conclusion, the epistemic status of the seminal, field-dominating definition of burnout is questioned. It is suggested that systematic clinical observation should be given a central place in future research on burnout-depression overlap.

  15. Overlaps between Frailty and Sarcopenia Definitions.

    PubMed

    Cederholm, Tommy

    2015-01-01

    Aging is characterized by the catabolism of muscles leading to sarcopenia and frailty. These are two geriatric syndromes with partly overlapping phenotypes. Primary sarcopenia, i.e. loss of muscle mass and function related to aging alone, usually precedes frailty. Thus, robustness passes from sarcopenia over frailty to disability leading eventually to a mortal outcome. Frailty (defined according to the phenotype model) encompasses states as exhaustion, weakness, and slowness, whereas sarcopenia, combining mass and function, is more strictly focused on muscles. Frailty is age related, whereas sarcopenia is also related to disease, starvation, and disuse. In general, the criteria for the two conditions overlap, but frailty requires weight loss, whereas sarcopenia requires muscle loss. Both gait speed and hand grip strength are suggested to be used as diagnostic measures for the two conditions since muscle function is crucial for any of the two syndromes. It is suggested that frailty screening should be part of the geriatric comprehensive assessment starting with measuring walking capacity and complemented by taking a history of fatigue and low activity. For younger adults (i.e. <70 years), sarcopenia screening could first register gait speed or hand grip strength and then body composition measurements. Simple questionnaires are feasible clinical alternatives. Treatment of frailty and sarcopenia overlaps, i.e. provide adequate protein and vitamin D supplementation, and encourage resistance exercise. PMID:26484770

  16. Protein gelation kinetics near the overlap concentration

    NASA Astrophysics Data System (ADS)

    Tabatabai, Pasha; Partlow, Benjamin; Kaplan, David; Blair, Daniel

    Proteins can be crosslinked to form gel networks either as a tool to study biological problems or as a method for creating novel materials. The bulk mechanical properties of protein gels in steady state are a manifestation of the gel structure, but the polymerization kinetics are often disregarded. Using the gelation of an aqueous denatured silk protein solution as a model polymer system, we probe the gelation kinetics (modulus vs. time) and find two regimes that depend on whether the initial protein concentration (c) is near or below the overlap concentration (c *) . We find that systems with c / c * ~ 1 exhibit immediate and single-mode modulus growth until the completion of polymerization that can be scaled onto a characteristic polymerization curve. However, systems with c / c * < 1 display delayed modulus development followed by two-stage modulus growth that can be normalized onto a separate distinctive polymerization curve. These two regimes are probed by changing both the initial concentration and the overlap concentration separately, emphasizing the importance of the overlap concentration on the assembly of polymeric/complex fluids.

  17. Function approximation using adaptive and overlapping intervals

    SciTech Connect

    Patil, R.B.

    1995-05-01

    A problem common to many disciplines is to approximate a function given only the values of the function at various points in input variable space. A method is proposed for approximating a function of several to one variable. The model takes the form of weighted averaging of overlapping basis functions defined over intervals. The number of such basis functions and their parameters (widths and centers) are automatically determined using given training data and a learning algorithm. The proposed algorithm can be seen as placing a nonuniform multidimensional grid in the input domain with overlapping cells. The non-uniformity and overlap of the cells is achieved by a learning algorithm to optimize a given objective function. This approach is motivated by the fuzzy modeling approach and a learning algorithms used for clustering and classification in pattern recognition. The basics of why and how the approach works are given. Few examples of nonlinear regression and classification are modeled. The relationship between the proposed technique, radial basis neural networks, kernel regression, probabilistic neural networks, and fuzzy modeling is explained. Finally advantages and disadvantages are discussed.

  18. Pulse stretcher

    DOEpatents

    Horton, J.A.

    1994-05-03

    Apparatus for increasing the length of a laser pulse to reduce its peak power without substantial loss in the average power of the pulse is disclosed. The apparatus uses a White cell having a plurality of optical delay paths of successively increasing number of passes between the field mirror and the objective mirrors. A pulse from a laser travels through a multi-leg reflective path between a beam splitter and a totally reflective mirror to the laser output. The laser pulse is also simultaneously injected through the beam splitter to the input mirrors of the optical delay paths. The pulses from the output mirrors of the optical delay paths go simultaneously to the laser output and to the input mirrors of the longer optical delay paths. The beam splitter is 50% reflective and 50% transmissive to provide equal attenuation of all of the pulses at the laser output. 6 figures.

  19. Pulse Voltammetry

    NASA Astrophysics Data System (ADS)

    Stojek, Zbigniew

    The idea of imposing potential pulses and measuring the currents at the end of each pulse was proposed by Barker in a little-known journal as early as in 1958 [1]. However, the first reliable trouble-free and affordable polarographs offering voltammetric pulse techniques appeared on the market only in the 1970s. This delay was due to some limitations on the electronic side. In the 1990s, again substantial progress in electrochemical pulse instrumentation took place. This was related to the introduction of microprocessors, computers, and advanced software.

  20. Overlapping Spreading Centers: Implications from Crack Growth Simulation by the Displacement Discontinuity Method

    NASA Astrophysics Data System (ADS)

    Sempere, Jean-Christophe; MacDonald, Ken C.

    1986-02-01

    Overlapping spreading centers (OSC's) are a fundamental aspect of accretionary processes at intermediate and fast-spreading centers and typically occur at deep points along the axial depth profile. They have a characteristic geometry consisting of two en echelon overlapping, curving ridges separated by an elongated depression. The length to width ratio of this overlap basin is typically 3∶1. We have been successful in reproducing the overlapping spreading center geometry by modelling the growth of two initially parallel elastic cracks of given length and offset in a tensile stress field at infinity. A boundary element displacement discontinuity method was used to solve this problem. Our calculated results are compared with seafloor observations in terms of the size and shape of the overlap region. For small OSC's, there is a very good agreement between calculations and observations but, for large ones, the overlap basin tends to be longer than our predicted results indicate. This suggests that the assumptions made in the model (i.e., perfectly elastic, isotropic and homogeneous medium) are perhaps valid for the brittle lid above the magma chamber that underlies OSC's with small offsets (< 2 km) but oversimplified for OSC's with large offsets. Our modelling shows that the initial interaction of closely spaced surface ruptures along spreading centers is to deflect away from one another as they approach. The deflection will be the greatest for small misalignments of the fracture systems, thus even minor misalignments of the spreading centers may result in the development of OSC's. Where the misalignment is less than the width of the cracking front, the fracture systems may meet head-on creating a saddle point along the axial depth profile. Our results support the hypothesis suggested by Macdonald et al. [1984] in which overlapping spreading centers develop where two magmatic pulses migrate toward each other along the strike of the spreading center following fracture

  1. Efficient discovery of overlapping communities in massive networks

    PubMed Central

    Gopalan, Prem K.; Blei, David M.

    2013-01-01

    Detecting overlapping communities is essential to analyzing and exploring natural networks such as social networks, biological networks, and citation networks. However, most existing approaches do not scale to the size of networks that we regularly observe in the real world. In this paper, we develop a scalable approach to community detection that discovers overlapping communities in massive real-world networks. Our approach is based on a Bayesian model of networks that allows nodes to participate in multiple communities, and a corresponding algorithm that naturally interleaves subsampling from the network and updating an estimate of its communities. We demonstrate how we can discover the hidden community structure of several real-world networks, including 3.7 million US patents, 575,000 physics articles from the arXiv preprint server, and 875,000 connected Web pages from the Internet. Furthermore, we demonstrate on large simulated networks that our algorithm accurately discovers the true community structure. This paper opens the door to using sophisticated statistical models to analyze massive networks. PMID:23950224

  2. Growing networks of overlapping communities with internal structure.

    PubMed

    Young, Jean-Gabriel; Hébert-Dufresne, Laurent; Allard, Antoine; Dubé, Louis J

    2016-08-01

    We introduce an intuitive model that describes both the emergence of community structure and the evolution of the internal structure of communities in growing social networks. The model comprises two complementary mechanisms: One mechanism accounts for the evolution of the internal link structure of a single community, and the second mechanism coordinates the growth of multiple overlapping communities. The first mechanism is based on the assumption that each node establishes links with its neighbors and introduces new nodes to the community at different rates. We demonstrate that this simple mechanism gives rise to an effective maximal degree within communities. This observation is related to the anthropological theory known as Dunbar's number, i.e., the empirical observation of a maximal number of ties which an average individual can sustain within its social groups. The second mechanism is based on a recently proposed generalization of preferential attachment to community structure, appropriately called structural preferential attachment (SPA). The combination of these two mechanisms into a single model (SPA+) allows us to reproduce a number of the global statistics of real networks: The distribution of community sizes, of node memberships, and of degrees. The SPA+ model also predicts (a) three qualitative regimes for the degree distribution within overlapping communities and (b) strong correlations between the number of communities to which a node belongs and its number of connections within each community. We present empirical evidence that support our findings in real complex networks. PMID:27627327

  3. Growing networks of overlapping communities with internal structure

    NASA Astrophysics Data System (ADS)

    Young, Jean-Gabriel; Hébert-Dufresne, Laurent; Allard, Antoine; Dubé, Louis J.

    2016-08-01

    We introduce an intuitive model that describes both the emergence of community structure and the evolution of the internal structure of communities in growing social networks. The model comprises two complementary mechanisms: One mechanism accounts for the evolution of the internal link structure of a single community, and the second mechanism coordinates the growth of multiple overlapping communities. The first mechanism is based on the assumption that each node establishes links with its neighbors and introduces new nodes to the community at different rates. We demonstrate that this simple mechanism gives rise to an effective maximal degree within communities. This observation is related to the anthropological theory known as Dunbar's number, i.e., the empirical observation of a maximal number of ties which an average individual can sustain within its social groups. The second mechanism is based on a recently proposed generalization of preferential attachment to community structure, appropriately called structural preferential attachment (SPA). The combination of these two mechanisms into a single model (SPA+) allows us to reproduce a number of the global statistics of real networks: The distribution of community sizes, of node memberships, and of degrees. The SPA+ model also predicts (a) three qualitative regimes for the degree distribution within overlapping communities and (b) strong correlations between the number of communities to which a node belongs and its number of connections within each community. We present empirical evidence that support our findings in real complex networks.

  4. Possible sources of pulse-to-pulse orbit variation in the SLAC linac

    SciTech Connect

    Assmann, R.; Zimmermann, F.

    1996-08-01

    Pulse-to-pulse variation of the transverse beam orbit, frequently referred to as jitter, has long been a major problem in SLC operation. It impairs the SLC luminosity both by reducing the average beam overlap at the IP and by hampering precision tuning of the final focus. The origin of the fast orbit variation is not fully understood. Measurements during the 1994/95 SLC run showed that it is random from pulse to pulse, increases strongly with current and grows steadily along the SLAC linac, with a typical final rms amplitude of about half the beam size. In this paper, they investigate possible sources of the vertical orbit jitter.

  5. Influence of slice overlap on positron emission tomography image quality

    NASA Astrophysics Data System (ADS)

    McKeown, Clare; Gillen, Gerry; Dempsey, Mary Frances; Findlay, Caroline

    2016-02-01

    PET scans use overlapping acquisition beds to correct for reduced sensitivity at bed edges. The optimum overlap size for the General Electric (GE) Discovery 690 has not been established. This study assesses how image quality is affected by slice overlap. Efficacy of 23% overlaps (recommended by GE) and 49% overlaps (maximum possible overlap) were specifically assessed. European Association of Nuclear Medicine (EANM) guidelines for calculating minimum injected activities based on overlap size were also reviewed. A uniform flood phantom was used to assess noise (coefficient of variation, (COV)) and voxel accuracy (activity concentrations, Bq ml-1). A NEMA (National Electrical Manufacturers Association) body phantom with hot/cold spheres in a background activity was used to assess contrast recovery coefficients (CRCs) and signal to noise ratios (SNR). Different overlap sizes and sphere-to-background ratios were assessed. COVs for 49% and 23% overlaps were 9% and 13% respectively. This increased noise was difficult to visualise on the 23% overlap images. Mean voxel activity concentrations were not affected by overlap size. No clinically significant differences in CRCs were observed. However, visibility and SNR of small, low contrast spheres (⩽13 mm diameter, 2:1 sphere to background ratio) may be affected by overlap size in low count studies if they are located in the overlap area. There was minimal detectable influence on image quality in terms of noise, mean activity concentrations or mean CRCs when comparing 23% overlap with 49% overlap. Detectability of small, low contrast lesions may be affected in low count studies—however, this is a worst-case scenario. The marginal benefits of increasing overlap from 23% to 49% are likely to be offset by increased patient scan times. A 23% overlap is therefore appropriate for clinical use. An amendment to EANM guidelines for calculating injected activities is also proposed which better reflects the effect overlap size has

  6. Voriconazole-induced periostitis in a patient with overlap syndromes.

    PubMed

    Hirota, Keisho; Yasoda, Akihiro; Fujii, Toshihito; Inagaki, Nobuya

    2014-03-05

    A 52-year-old woman with overlap syndrome and interstitial pneumonia underwent immunosuppressive therapy and she was suspected to suffer from pulmonary aspergillosis. Oral voriconazole was initiated, and a rapid elevation of alkaline phosphatase (ALP) occurred after 4 weeks. After 2 months, the patient presented diffuse pain in bilateral skeletal regions, and bone scintigraphy revealed bilateral multiple areas of increased radiotracer uptake. We suspected the skeletal involvement as voriconazole-induced periostitis. Actually, the plasma fluoride level was increased. Voriconazole was replaced with itraconazole, and after 3 weeks, the patient stopped complaining of bone pain concomitant with the decrease in ALP. Voriconazole-induced periostitis is a rare condition but had previously been reported in solid organ or patients with bone marrow transplant who received a long-term voriconazole therapy. Our present case is distinctive of previous ones, because it occurred in a patient with connective tissue disease which had its rapid progression.

  7. Overlap populations, bond orders and valences for 'fuzzy' atoms

    NASA Astrophysics Data System (ADS)

    Mayer, I.; Salvador, P.

    2004-01-01

    Proper definitions are proposed to calculate interatomic overlap populations, bond order (multiplicity) indices and actual atomic valences from the results of ab initio quantum chemical calculations, in terms of 'fuzzy' atoms, i.e., such divisions of the three-dimensional physical space into atomic regions in which the regions assigned to the individual atoms have no sharp boundaries but exhibit a continuous transition from one to another. The results of test calculations are in agreement with the classical chemical notions, exhibit unexpectedly small basis sensitivity and do not depend too much on the selection of the weight function defining the actual division of the space into 'fuzzy' atomic regions. The scheme is applicable on both SCF and correlated levels of theory. A free program is available.

  8. Cenozoic Motion of Greenland - Overlaps and Seaways

    NASA Astrophysics Data System (ADS)

    Lawver, L. A.; Norton, I. O.; Gahagan, L.

    2014-12-01

    Using the seafloor magnetic anomalies found in the Labrador Sea, North Atlantic and Eurasian basin to constrain the Cenozoic motion of Greenland, we have produced a new model for the tectonic evolution of the region. The aeromagnetic data collected by the Naval Research Lab [Brozena et al., 2003] in the Eurasian Basin and Canadian data from the Labrador Sea have been re-evaluated using new gridding algorithms and profile modeling using ModMag (Mendel et al., 2005). As a consequence, we have changed the published correlations, mostly prior to Chron C6 [19.05 Ma]. Presently published seafloor magnetic anomalies from the Labrador Sea assume that seafloor spreading ceased at C13 [33.06 Ma] but such an assumption produces an unacceptable overlap of Kronprins Christian Land of northeast Greenland with Svalbard, up to 140 km of overlap in some models. Our new model does not need any "unacceptable" overlap but does produce a slight amount of Eocene compression on Svalbard as is found on land there. Our model allows for an Early Eocene seaway between Ellesmere Island and northwest Greenland that may have connected the Labrador Sea through Baffin Bay and ultimately to the nascent Eurasian Basin, although its depth or even its essential existence is unknowable. During the Miocene, there is no room for a deepwater seaway in Fram Strait until at least the very end of the Early Miocene and perhaps not until Middle Miocene. Brozena, J. and six others, 2003. New aerogeophysical study of the Eurasia Basin and Lomonosov Ridge: Implications for basin development. Geology 31, 825-828. Mendel, V., M. Munschy and D.Sauter, 2005, MODMAG, a MATLAB program to model marine magnetic anomalies, Comp. Geosci., 31, .589-597

  9. High-speed pulse-shape generator, pulse multiplexer

    DOEpatents

    Burkhart, Scott C.

    2002-01-01

    The invention combines arbitrary amplitude high-speed pulses for precision pulse shaping for the National Ignition Facility (NIF). The circuitry combines arbitrary height pulses which are generated by replicating scaled versions of a trigger pulse and summing them delayed in time on a pulse line. The combined electrical pulses are connected to an electro-optic modulator which modulates a laser beam. The circuit can also be adapted to combine multiple channels of high speed data into a single train of electrical pulses which generates the optical pulses for very high speed optical communication. The invention has application in laser pulse shaping for inertial confinement fusion, in optical data links for computers, telecommunications, and in laser pulse shaping for atomic excitation studies. The invention can be used to effect at least a 10.times. increase in all fiber communication lines. It allows a greatly increased data transfer rate between high-performance computers. The invention is inexpensive enough to bring high-speed video and data services to homes through a super modem.

  10. PULSE AMPLIFIER

    DOEpatents

    Johnstone, C.W.

    1958-06-17

    The improvement of pulse amplifiers used with scintillation detectors is described. The pulse amplifier circuit has the advantage of reducing the harmful effects of overloading cause by large signal inputs. In general the pulse amplifier circuit comprises two amplifier tubes with the input pulses applied to one amplifier grid and coupled to the second amplifier tube through a common cathode load. The output of the second amplifier is coupled from the plate circuit to a cathode follower tube grid and a diode tube in connected from grid to cathode of the cathode follower tube. Degenerative feedback is provided in the second amplifier by coupling a signal from the cathode follower cathode to the second amplifier grid. The circuit proqides moderate gain stability, and overload protection for subsequent pulse circuits.

  11. Compact program resolves overlapping voltammetric peaks.

    PubMed

    Dimitrov, Jordan D

    2004-05-01

    A simple self-contained program designed to separate overlapping peaks from electrochemical analyses is presented. Combining an original interactive way to define initial parameter estimates with nonlinear curve fitting based on the simplex method of optimization, it allows the user to resolve voltammograms consisting of 2 to 5 analytical peaks raised on a straight base line. The program provides highly intuitive interface, easy operation, and straightforward result documentation. A free package including the program, three data files and user instructions is available on request.

  12. Technology initiatives with government/business overlap

    NASA Astrophysics Data System (ADS)

    Knapp, Robert H., Jr.

    2015-03-01

    Three important present-day technology development settings involve significant overlap between government and private sectors. The Advanced Research Project Agency for Energy (ARPA-E) supports a wide range of "high risk, high return" projects carried out in academic, non-profit or private business settings. The Materials Genome Initiative (MGI), based in the White House, aims at radical acceleration of the development process for advanced materials. California public utilities such as Pacific Gas & Electric operate under a structure of financial returns and political program mandates that make them arms of public policy as much as independent businesses.

  13. Theory of perturbative pulse train based coherent control

    NASA Astrophysics Data System (ADS)

    Grinev, Timur; Brumer, Paul

    2014-03-01

    A theoretical description of coherent control of excited state dynamics using pulse trains in the perturbative regime, as carried out in recent experiments, is presented. Analytical expressions relating the excited state populations to the pulse train control parameters are derived. Numerical examples are provided for models of pyrazine and β-carotene, and the significant role of overlapping resonances is exposed.

  14. Patellar Articular Overlap on MRI Is a Simple Alternative to Conventional Measurements of Patellar Height

    PubMed Central

    Munch, Jacqueline L.; Sullivan, Jaron P.; Nguyen, Joseph T.; Mintz, Douglas; Green, Daniel W.; Shubin Stein, Beth E.; Strickland, Sabrina

    2016-01-01

    Background: Patella alta describes an abnormally high-riding patella in relationship to the femur and has been shown to correlate with patellofemoral pain, instability, chondromalacia, and arthrosis. Conventional measurements of patella alta involve multiple measurements and are often not defined on cross-sectional imaging as related to radiographs. Hypothesis: Patellar articular overlap on sagittal magnetic resonance imaging (MRI) will correlate well with conventional measurements of patella alta as measured by a standardized technique defined by our group. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: MRIs of 239 knees were reviewed by 3 attending surgeons with practices focusing on patellofemoral disease, as well as 2 sports medicine fellows and 1 musculoskeletal radiologist. Measurements included articular overlap, percentage of articular coverage, Caton-Deschamps index, Blackburne-Peel index, and modified Insall-Salvati index. Results: Interrater reliability was high for Caton-Deschamps, Blackburne-Peel, and modified Insall-Salvati indices (intraclass correlation coefficient [ICC], 0.877, 0.828, and 0.787, respectively). Articular overlap and percentage articular coverage correlated well with each other (ICC, 0.961; P < .001) and with the Caton-Deschamps (overlap r = –0.271, P < .001; coverage r = –0.131, P = .037) and Blackburne-Peel (overlap r = 0.343, P < .001; coverage r = –0.238, P < .001) indices. Articular overlap and percentage coverage failed to correlate with the modified Insall-Salvati index (overlap r = –0.117, P = .091; coverage r = 0.007, P = .918). Conclusion: Patellar articular overlap and percentage of patellar articular coverage show promise as a simpler alternative to conventional, ratio-based measurements of patellar height. Future studies are needed to evaluate the range of normal and the relationship to our traditionally used measurements. PMID:27482530

  15. Pulse transmission receiver with higher-order time derivative pulse correlator

    DOEpatents

    Dress, Jr., William B.; Smith, Stephen F.

    2003-09-16

    Systems and methods for pulse-transmission low-power communication modes are disclosed. A pulse transmission receiver includes: a higher-order time derivative pulse correlator; a demodulation decoder coupled to the higher-order time derivative pulse correlator; a clock coupled to the demodulation decoder; and a pseudorandom polynomial generator coupled to both the higher-order time derivative pulse correlator and the clock. The systems and methods significantly reduce lower-frequency emissions from pulse transmission spread-spectrum communication modes, which reduces potentially harmful interference to existing radio frequency services and users and also simultaneously permit transmission of multiple data bits by utilizing specific pulse shapes.

  16. Overlapping genes in the human and mouse genomes

    PubMed Central

    Sanna, Chaitanya R; Li, Wen-Hsiung; Zhang, Liqing

    2008-01-01

    Background Increasing evidence suggests that overlapping genes are much more common in eukaryotic genomes than previously thought. In this study we identified and characterized the overlapping genes in a set of 13,484 pairs of human-mouse orthologous genes. Results About 10% of the genes under study are overlapping genes, the majority of which are different-strand overlaps. The majority of the same-strand overlaps are embedded forms, whereas most different-strand overlaps are not embedded and in the convergent transcription orientation. Most of the same-strand overlapping gene pairs show at least a tenfold difference in length, much larger than the length difference between non-overlapping neighboring gene pairs. The length difference between the two different-strand overlapping genes is less dramatic. Over 27% of the different-strand-overlap relationships are shared between human and mouse, compared to only ~8% conservation for same-strand-overlap relationships. More than 96% of the same-strand and different-strand overlaps that are not shared between human and mouse have both genes located on the same chromosomes in the species that does not show the overlap. We examined the causes of transition between the overlapping and non-overlapping states in the two species and found that 3' UTR change plays an important role in the transition. Conclusion Our study contributes to the understanding of the evolutionary transition between overlapping genes and non-overlapping genes and demonstrates the high rates of evolutionary changes in the un-translated regions. PMID:18410680

  17. Multiple pulse-heating experiments with different current to determine total emissivity, heat capacity, and electrical resistivity of electrically conductive materials at high temperatures.

    PubMed

    Watanabe, Hiromichi; Yamashita, Yuichiro

    2012-01-01

    A modified pulse-heating method is proposed to improve the accuracy of measurement of the hemispherical total emissivity, specific heat capacity, and electrical resistivity of electrically conductive materials at high temperatures. The proposed method is based on the analysis of a series of rapid resistive self-heating experiments on a sample heated at different temperature rates. The method is used to measure the three properties of the IG-110 grade of isotropic graphite at temperatures from 850 to 1800 K. The problem of the extrinsic heating-rate effect, which reduces the accuracy of the measurements, is successfully mitigated by compensating for the generally neglected experimental error associated with the electrical measurands (current and voltage). The results obtained by the proposed method can be validated by the linearity of measured quantities used in the property determinations. The results are in reasonably good agreement with previously published data, which demonstrate the suitability of the proposed method, in particular, to the resistivity and total emissivity measurements. An interesting result is the existence of a minimum in the emissivity of the isotropic graphite at around 1120 K, consistent with the electrical resistivity results.

  18. Measurements of multiple gas parameters in a pulsed-detonation combustor using time-division-multiplexed Fourier-domain mode-locked lasers.

    PubMed

    Caswell, Andrew W; Roy, Sukesh; An, Xinliang; Sanders, Scott T; Schauer, Frederick R; Gord, James R

    2013-04-20

    Hyperspectral absorption spectroscopy is being used to monitor gas temperature, velocity, pressure, and H(2)O mole fraction in a research-grade pulsed-detonation combustor (PDC) at the Air Force Research Laboratory. The hyperspectral source employed is termed the TDM 3-FDML because it consists of three time-division-multiplexed (TDM) Fourier-domain mode-locked (FDML) lasers. This optical-fiber-based source monitors sufficient spectral information in the H(2)O absorption spectrum near 1350 nm to permit measurements over the wide range of conditions encountered throughout the PDC cycle. Doppler velocimetry based on absorption features is accomplished using a counterpropagating beam approach that is designed to minimize common-mode flow noise. The PDC in this study is operated in two configurations: one in which the combustion tube exhausts directly to the ambient environment and another in which it feeds an automotive-style turbocharger to assess the performance of a detonation-driven turbine. Because the enthalpy flow [kilojoule/second] is important in assessing the performance of the PDC in various configurations, it is calculated from the measured gas properties. PMID:23669701

  19. Measurements of multiple gas parameters in a pulsed-detonation combustor using time-division-multiplexed Fourier-domain mode-locked lasers.

    PubMed

    Caswell, Andrew W; Roy, Sukesh; An, Xinliang; Sanders, Scott T; Schauer, Frederick R; Gord, James R

    2013-04-20

    Hyperspectral absorption spectroscopy is being used to monitor gas temperature, velocity, pressure, and H(2)O mole fraction in a research-grade pulsed-detonation combustor (PDC) at the Air Force Research Laboratory. The hyperspectral source employed is termed the TDM 3-FDML because it consists of three time-division-multiplexed (TDM) Fourier-domain mode-locked (FDML) lasers. This optical-fiber-based source monitors sufficient spectral information in the H(2)O absorption spectrum near 1350 nm to permit measurements over the wide range of conditions encountered throughout the PDC cycle. Doppler velocimetry based on absorption features is accomplished using a counterpropagating beam approach that is designed to minimize common-mode flow noise. The PDC in this study is operated in two configurations: one in which the combustion tube exhausts directly to the ambient environment and another in which it feeds an automotive-style turbocharger to assess the performance of a detonation-driven turbine. Because the enthalpy flow [kilojoule/second] is important in assessing the performance of the PDC in various configurations, it is calculated from the measured gas properties.

  20. Serial FBG sensor network allowing overlapping spectra

    NASA Astrophysics Data System (ADS)

    Abbenseth, S.; Lochmann, S.; Ahrens, A.; Rehm, B.

    2016-05-01

    For structure or material monitoring low impact serial fiber Bragg grating (FBG) networks have attracted increasing research interest. Common sensor networks using wavelength division multiplexing (WDM) for FBG interrogation are limited in their efficiency by the spectral width of their light source, the FBG tuning range and the spectral guard bands. Overlapping spectra are strictly forbidden in this case. Applying time division multiplexing (TDM) or active resonator schemes may overcome these restrictions. However, they introduce other substantial disadvantages like signal roundtrip dependency or sophisticated control of active resonating structures. Code division multiplexing (CDM) as a means of FBG interrogation by simple autocorrelation of appropriate codes has been shown to be superior in this respect. However, it came at the cost of a second spectrometer introducing additional equalization efforts. We demonstrate a new serial FBG sensor network utilizing CDM signal processing for efficient sensor interrogation without the need of a second spectrometer and additional state of polarization (SOP) controlling components. It allows overlapping spectra even when all sensing FBGs are positioned at the same centre wavelength and it shows a high degree of insensitivity to SOP. Sequence inversed keyed (SIK) serial signal processing utilizing quasi-orthogonal balanced codes ensures simple and quick sensor interrogation with high signal-to-interference/noise ratio.

  1. In vivo single-shot three-dimensionally localized multiple quantum spectroscopy of GABA in the human brain with improved spectral selectivity

    NASA Astrophysics Data System (ADS)

    Choi, In-Young; Lee, Sang-Pil; Shen, Jun

    2005-01-01

    A single-shot multiple quantum filtering method is developed that uses two double-band frequency selective pulses for enhanced spectral selectivity in combination with a slice-selective 90°, a slice-selective universal rotator 90°, and a spectral-spatial pulse composed of two slice-selective universal rotator 45° pulses for single-shot three-dimensional localization. The use of this selective multiple quantum filtering method for C3 and C4 methylene protons of GABA resulted in improved spectral selectivity for GABA and effective suppression of overlapping signals such as creatine and glutathione in each single scan, providing reliable measurements of the GABA doublet in all subjects. The concentration of GABA was measured to be 0.7 ± 0.2 μmol/g (means ± SD, n = 15) in the fronto-parietal region of the human brain in vivo.

  2. The overlap-Dirac operator: Topology and chiral symmetry breaking

    SciTech Connect

    Edwards, R.G.; Heller, U.M.; Narayanan, R.

    2000-01-01

    The authors review the spectral flow techniques for computing the index of the overlap Dirac operator including results relevant for SUSY Yang-Mills theories. They describe properties of the overlap Dirac operator, and methods to implement it numerically. They use the results from the spectral flow to illuminate the difficulties in numerical calculations involving domain wall and overlap fermions.

  3. Phonological and Orthographic Overlap Effects in Fast and Masked Priming

    PubMed Central

    Frisson, Steven; Bélanger, Nathalie N.; Rayner, Keith

    2014-01-01

    We investigated how orthographic and phonological information is activated during reading, using a fast priming task, and during single word recognition, using masked priming. Specifically, different types of overlap between prime and target were contrasted: high orthographic and high phonological overlap (track-crack), high orthographic and low phonological overlap (bear-gear), or low orthographic and high phonological overlap (fruit-chute). In addition, we examined whether (orthographic) beginning overlap (swoop-swoon) yielded the same priming pattern as end (rhyme) overlap (track-crack). Prime durations were 32 and 50ms in the fast priming version, and 50ms in the masked priming version, and mode of presentation (prime and target in lower case) was identical. The fast priming experiment showed facilitatory priming effects when both orthography and phonology overlapped, with no apparent differences between beginning and end overlap pairs. Facilitation was also found when prime and target only overlapped orthographically. In contrast, the masked priming experiment showed inhibition for both types of end overlap pairs (with and without phonological overlap), and no difference for begin overlap items. When prime and target only shared principally phonological information, facilitation was only found with a long prime duration in the fast priming experiment, while no differences were found in the masked priming version. These contrasting results suggest that fast priming and masked priming do not necessarily tap into the same type of processing. PMID:24365065

  4. 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)

  5. Social externalities, overlap and the poverty trap.

    PubMed

    Kim, Young-Chul; Loury, Glenn C

    2014-12-01

    Previous studies find that some social groups are stuck in poverty traps because of network effects. However, these studies do not carefully analyze how these groups overcome low human capital investment activities. Unlike previous studies, the model in this paper includes network externalities in both the human capital investment stage and the subsequent career stages. This implies that not only the current network quality, but also the expectations about future network quality affect the current investment decision. Consequently, the coordinated expectation among the group members can play a crucial role in the determination of the final state. We define "overlap" for some initial skill ranges, whereby the economic performance of a group can be improved simply by increasing expectations of a brighter future. We also define "poverty trap" for some ranges, wherein a disadvantaged group is constrained by its history, and we explore the egalitarian policies to mobilize the group out of the trap.

  6. Dimensional overlap between time and space.

    PubMed

    Eikmeier, Verena; Schröter, Hannes; Maienborn, Claudia; Alex-Ruf, Simone; Ulrich, Rolf

    2013-12-01

    Several pieces of evidence suggest that our mental representations of time and space are linked. However, the extent of this linkage between the two domains has not yet been assessed. We present the results of two experiments that draw on the predictions of the dimensional overlap model (Kornblum, Hasbroucq, & Osman, Psychological Review 97:253-270, 1990). The stimulus and response sets in these reaction time experiments were related to either time or space. The obtained stimulus-response congruency effects were of about the same size for identical stimulus-response sets (time-time or space-space) and for different stimulus-response sets (time-space or space-time). These results support the view that our representations of time and space are strongly linked.

  7. SU-E-T-181: Feasibility and Robustness of Using Overlapping VMAT Arcs for Conformal Irradiation of Large Irregular PTVs

    SciTech Connect

    Liu, H; Kim, J; Chen, Z

    2014-06-01

    Purpose: To investigate the feasibility and robustness of using multiple overlapping arcs for delivering volumetric modulated arc therapy (VMAT) to irregular PTVs with large superior-inferior (SI) dimensions. Methods: A patient with stage IV alveolar rhabdomyosarcoma, with a combined PTV length of 56 cm in SI direction, was planned and treated in our department using two VMAT arcs overlapped along the SI direction to take advantage of the much needed dose sculpting capabilities of VMAT. The overlapping VMATs, each consisted of two arcs, were optimized simultaneously using Varian Eclipse system. The susceptibility of the resulting plan to uncertainties associated the set up of two separate isocenters during treatment was investigated by comparing the dose distributions resulted from small shifts introduced into the isocenter position. The robustness of this technique was further assessed for plans generated using different amount of overlap between the overlapping arcs. Results: When the plan was generated with 6 cm overlap between adjacent arcs, maximum dose variations observed near overlapping edges was up to 9.2%, 10%, and 26.7% for setup uncertainties of 2 mm, 3 mm, and 5 mm, respectively. By increasing the junction overlap to 16 cm, maximum dose variations was reduced to 4.2%, 6.5%, and 10.2% for setup uncertainties of 2 mm, 3 mm, and 5 mm, respectively. In general, dose variation was found to increase dramatically with increasing magnitude of setup uncertainty. The technique can be made more robust against setup uncertainty by using large overlap between adjacent VMAT arcs. Conclusion: Overlapping VMAT arcs can be used effectively for conformal irradiation of PTVs with large SI dimension. The dosimetric impact of uncertainties in required isocenter shifts can be minimized by planning with large overlap between adjacent arcs and by keeping setup uncertainty ≤ 2mm.

  8. Pulse stretcher

    DOEpatents

    Horton, James A.

    1994-01-01

    Apparatus (20) for increasing the length of a laser pulse to reduce its peak power without substantial loss in the average power of the pulse. The apparatus (20) uses a White cell (10) having a plurality of optical delay paths (18a-18d) of successively increasing number of passes between the field mirror (13) and the objective mirrors (11 and 12). A pulse (26) from a laser (27) travels through a multi-leg reflective path (28) between a beam splitter (21) and a totally reflective mirror (24) to the laser output (37). The laser pulse (26) is also simultaneously injected through the beam splitter (21) to the input mirrors (14a-14d) of the optical delay paths (18a-18d). The pulses from the output mirrors (16a-16d) of the optical delay paths (18a-18d) go simultaneously to the laser output (37) and to the input mirrors ( 14b-14d) of the longer optical delay paths. The beam splitter (21) is 50% reflective and 50% transmissive to provide equal attenuation of all of the pulses at the laser output (37).

  9. Microstructural evolution at the overlap zones of 12Cr martensitic stainless steel laser alloyed with TiC

    NASA Astrophysics Data System (ADS)

    Adebiyi, D. I.; Popoola, A. P. I.; Pityana, S. L.

    2014-09-01

    Multiple track laser alloying is characterised by additional heat treatment and differences in the amount of powder deposited at the overlap regions. These result in different microstructural and phase evolution at these regions, which are not obtainable in the single tracks. X12CrNiMo steel has been laser alloyed with TiC using a 4.4 kW continuous wave (CW) Nd:YAG laser. The process parameters were first optimised after which they were kept constant for overlap ratios of 50% and 75%. The depths of the alloyed zone, the mcrostructural evolution, metallurgical structures and compositions are different for the 50% and 75% overlap. The 75% overlap sample has an alloying depth of 4233 μm (about two times that of the 50% overlap). The XRD of the 50% overlap sample reveals the presence of complex carbides, which are absent in that of the 75% overlap. Although both overlap samples have retained martensite, diffractographs show that the martensite of the 75% is richer in carbide. These are attributed to differences in powder catchment, heat build-up and depth of alloying.

  10. Geometrical constraint experimental determination of Raman lidar overlap profile.

    PubMed

    Li, Jian; Li, Chengcai; Zhao, Yiming; Li, Jing; Chu, Yiqi

    2016-06-20

    A simple experimental method to determine the overlap profile of Raman lidar is presented in this paper. Based on Mie and Raman backscattering signals and a geometrically constrained condition, the overlap profile of a Raman lidar system can be determined. Our approach simultaneously retrieves the lidar ratio of aerosols, which is one of the most important sources of uncertainty in the overlap profile determination. The results indicate that the overlap factor is significantly influenced by the lidar ratio in experimental methods. A representative case study indicates that the correction of the overlap profile obtained by this method is practical and feasible.

  11. Geometrical constraint experimental determination of Raman lidar overlap profile.

    PubMed

    Li, Jian; Li, Chengcai; Zhao, Yiming; Li, Jing; Chu, Yiqi

    2016-06-20

    A simple experimental method to determine the overlap profile of Raman lidar is presented in this paper. Based on Mie and Raman backscattering signals and a geometrically constrained condition, the overlap profile of a Raman lidar system can be determined. Our approach simultaneously retrieves the lidar ratio of aerosols, which is one of the most important sources of uncertainty in the overlap profile determination. The results indicate that the overlap factor is significantly influenced by the lidar ratio in experimental methods. A representative case study indicates that the correction of the overlap profile obtained by this method is practical and feasible. PMID:27409119

  12. MOPA pulsed fiber laser for silicon scribing

    NASA Astrophysics Data System (ADS)

    Yang, Limei; Huang, Wei; Deng, Mengmeng; Li, Feng

    2016-06-01

    A 1064 nm master oscillator power amplifier (MOPA) pulsed fiber laser is developed with flexible control over the pulse width, repetition frequency and peak power, and it is used to investigate the dependence of mono-crystalline silicon scribe depth on the laser pulse width, scanning speed and repeat times. Experimental results indicate that long pulses with low peak powers lead to deep ablation depths. We also demonstrate that the ablation depth grows fast with the scanning repeat times at first and progressively tends to be saturated when the repeat times reach a certain level. A thermal model considering the laser pulse overlapping effect that predicts the silicon temperature variation and scribe depth is employed to verify the experimental conclusions with reasonably close agreement. These conclusions are of great benefits to the optimization of the laser material processing with high efficiency.

  13. A tutorial on structural equation modeling for analysis of overlapping symptoms in co-occurring conditions using MPlus.

    PubMed

    Gunzler, Douglas D; Morris, Nathan

    2015-10-30

    Structural equation modeling (SEM) is a very general approach to analyzing data in the presence of measurement error and complex causal relationships. In this tutorial, we describe SEM, with special attention to exploratory factor analysis, confirmatory factor analysis, and multiple indicator multiple cause modeling. The tutorial is motivated by a problem of symptom overlap routinely faced by clinicians and researchers, in which symptoms or test results are common to two or more co-occurring conditions. As a result of such overlap, diagnoses, treatment decisions, and inferences about the effectiveness of treatments for these conditions can be biased. This problem is further complicated by increasing reliance on patient-reported outcomes, which introduces systematic error based on an individual's interpretation of a test questionnaire. SEM provides flexibility in handling this type of differential item functioning and disentangling the overlap. Scales and scoring approaches can be revised to be free of this overlap, leading to better care. This tutorial uses an example of depression screening in multiple sclerosis patients in which depressive symptoms overlap with other symptoms, such as fatigue, cognitive impairment, and functional impairment. Details of how MPlus (Muthén & Muthén, Los Angeles, CA, USA) software can be used to address the symptom overlap problem, including data requirements, code and output are described in this tutorial.

  14. Overlap in Patients With Dyspepsia/Functional Dyspepsia

    PubMed Central

    Fujiwara, Yasuhiro; Arakawa, Tetsuo

    2014-01-01

    Patients with dyspepsia/functional dyspepsia (FD) show frequent overlapping of other gastrointestinal (GI) diseases, such as irritable bowel syndrome, and non-GI diseases, in addition to internal subgroup overlapping. These overlap patients have more frequent or more severe symptoms, poorer health-related quality of life and higher somatization scores, and they are more likely to experience anxiety, depression or insomnia compared to non-overlap patients. The higher prevalence of overlap in patients with dyspepsia/FD is not by chance, indicating common pathogeneses, including visceral hypersensitivity, altered GI motility, infection, and stressful early life events. There are few clinical trials targeting overlap in patients with dyspepsia/FD, and no therapeutic strategy has been established. Further studies in this research area are needed. In this review, we describe the epidemiology, pathogenesis and treatment of overlap in patients with dyspepsia/FD. PMID:25257470

  15. Suppression of relative flow by multiple domains in two-component Bose-Einstein condensates

    NASA Astrophysics Data System (ADS)

    Eto, Yujiro; Kunimi, Masaya; Tokita, Hidekatsu; Saito, Hiroki; Hirano, Takuya

    2015-07-01

    We investigate flow properties of immiscible Bose-Einstein condensates composed of two different Zeeman spin states of 87Rb. Two spatially overlapping condensates in the optical trap are prepared by application of a resonant radio-frequency pulse, and then the magnetic field gradient is applied in order to produce the atomic flow. We find that the spontaneous multiple-domain formation arising from the immiscible nature drastically changes the fluidity. The homogeneously overlapping condensates readily separate under the magnetic field gradient, and they form a stable configuration composed of the two layers. In contrast, the relative flow between two condensates is largely suppressed in the case where the magnetic field gradient is applied after spontaneous domain formation.

  16. Depression-Burnout Overlap in Physicians

    PubMed Central

    Wurm, Walter; Vogel, Katrin; Holl, Anna; Ebner, Christoph; Bayer, Dietmar; Mörkl, Sabrina; Szilagyi, Istvan-Szilard; Hotter, Erich; Kapfhammer, Hans-Peter; Hofmann, Peter

    2016-01-01

    Background Whether burnout is a distinct phenomenon rather than a type of depression and whether it is a syndrome, limited to three “core” components (emotional exhaustion, depersonalization and low personal accomplishment) are subjects of current debate. We investigated the depression-burnout overlap, and the pertinence of these three components in a large, representative sample of physicians. Methods In a cross-sectional study, all Austrian physicians were invited to answer a questionnaire that included the Major Depression Inventory (MDI), the Hamburg Burnout Inventory (HBI), as well as demographic and job-related parameters. Of the 40093 physicians who received an invitation, a total of 6351 (15.8%) participated. The data of 5897 participants were suitable for analysis. Results Of the participants, 10.3% were affected by major depression. Our study results suggest that potentially 50.7% of the participants were affected by symptoms of burnout. Compared to physicians unaffected by burnout, the odds ratio of suffering from major depression was 2.99 (95% CI 2.21–4.06) for physicians with mild, 10.14 (95% CI 7.58–13.59) for physicians with moderate, 46.84 (95% CI 35.25–62.24) for physicians with severe burnout and 92.78 (95% CI 62.96–136.74) for the 3% of participants with the highest HBI_sum (sum score of all ten HBI components). The HBI components Emotional Exhaustion, Personal Accomplishment and Detachment (representing depersonalization) tend to correlate more highly with the main symptoms of major depression (sadness, lack of interest and lack of energy) than with each other. A combination of the HBI components Emotional Exhaustion, Helplessness, Inner Void and Tedium (adj.R2 = 0.92) explained more HBI_sum variance than the three “core” components (adj.R2 = 0.85) of burnout combined. Cronbach’s alpha for Emotional Exhaustion, Helplessness, Inner Void and Tedium combined was 0.90 compared to α = 0.54 for the combination of the three

  17. Effects of overlap and pass number in CO2 laser skin resurfacing: preliminary results of residual thermal damage, cell death, and wound healing

    NASA Astrophysics Data System (ADS)

    Ross, E. V.; Glatter, Robert D.; Duke, Daniella; Grevelink, Joop M.

    1997-05-01

    Newer carbon-dioxide laser systems incorporating short pulse and scanning technology have been used effectively to resurface the skin. Although scarring is rare, as the number of resurfacing cases has increased, some hypertrophic scarring has been observed. Previous dermabrasion and continuous wave (cw) carbon-dioxide studies suggest that depth of injury and/or thermal damage are important predictors of scarring for a given anatomic region. To determine if overlapping laser pulses/scans significantly altered wound healing, we examined residual thermal damage, cell death, and histologic and clinical wound healing in a farm pig. The Ultrapulse and SilkTouch systems were used with various radiant exposures, degrees of overlap, and numbers of passes. Thermal damage was assessed by histology, and dermal cell viability was measured with nitrotetrazolium blue staining. Presence or absence of clinical scarring was determined by noting textural change and loss of skin markings. We observed that thermal damage and cell death depth did not increase significantly with pass number; however, by double-pulsing or double-scanning sites, residual thermal damage and cell death depth were increased as much as 100% over areas without immediate overlap of laser impacts. Also, scarring was increased focally in areas with overlap. We conclude that immediate overlapping of carbon- dioxide laser pulses/scans is a significant risk factor in increasing thermal damage, cell death, and scarring.

  18. EVOG: a database for evolutionary analysis of overlapping genes.

    PubMed

    Kim, Dae-Soo; Cho, Chi-Young; Huh, Jae-Won; Kim, Heui-Soo; Cho, Hwan-Gue

    2009-01-01

    Overlapping genes are defined as a pair of genes whose transcripts are overlapped. Recently, many cases of overlapped genes have been investigated in various eukaryotic organisms; however, their origin and transcriptional control mechanism has not yet been clearly determined. In this study, we implemented evolutionary visualizer for overlapping genes (EVOG), a Web-based DB with a novel visualization interface, to investigate the evolutionary relationship between overlapping genes. Using this technique, we collected and analyzed all overlapping genes in human, chimpanzee, orangutan, marmoset, rhesus, cow, dog, mouse, rat, chicken, Xenopus, zebrafish and Drosophila. This integrated database provides a manually curated database that displays the evolutionary features of overlapping genes. The EVOG DB components included a number of overlapping genes (10074 in human, 10,009 in chimpanzee, 67,039 in orangutan, 51,001 in marmoset, 219 in rhesus, 3627 in cow, 209 in dog, 10,700 in mouse, 7987 in rat, 1439 in chicken, 597 in Xenopus, 2457 in zebrafish and 4115 in Drosophila). The EVOG database is very effective and easy to use for the analysis of the evolutionary process of overlapping genes when comparing different species. Therefore, EVOG could potentially be used as the main tool to investigate the evolution of the human genome in relation to disease by comparing the expression profiles of overlapping genes. EVOG is available at http://neobio.cs.pusan.ac.kr/evog/.

  19. Localized overlap algorithm for unexpanded dispersion energies

    SciTech Connect

    Rob, Fazle; Szalewicz, Krzysztof; Misquitta, Alston J.; Podeszwa, Rafał

    2014-03-21

    First-principles-based, linearly scaling algorithm has been developed for calculations of dispersion energies from frequency-dependent density susceptibility (FDDS) functions with account of charge-overlap effects. The transition densities in FDDSs are fitted by a set of auxiliary atom-centered functions. The terms in the dispersion energy expression involving products of such functions are computed using either the unexpanded (exact) formula or from inexpensive asymptotic expansions, depending on the location of these functions relative to the dimer configuration. This approach leads to significant savings of computational resources. In particular, for a dimer consisting of two elongated monomers with 81 atoms each in a head-to-head configuration, the most favorable case for our algorithm, a 43-fold speedup has been achieved while the approximate dispersion energy differs by less than 1% from that computed using the standard unexpanded approach. In contrast, the dispersion energy computed from the distributed asymptotic expansion differs by dozens of percent in the van der Waals minimum region. A further increase of the size of each monomer would result in only small increased costs since all the additional terms would be computed from the asymptotic expansion.

  20. Effects of overlapping strings in pp collisions

    DOE PAGESBeta

    Bierlich, Christian; Gustafson, Gösta; Lönnblad, Leif; Tarasov, Andrey

    2015-03-26

    In models for hadron collisions based on string hadronization, the strings are usually treated as independent, allowing no interaction between the confined colour fields. In studies of nucleus collisions it has been suggested that strings close in space can fuse to form "colour ropes." Such ropes are expected to give more strange particles and baryons, which also has been suggested as a signal for plasma formation. Overlapping strings can also be expected in pp collisions, where usually no phase transition is expected. In particular at the high LHC energies the expected density of strings is quite high. To investigate possiblemore » effects of rope formation, we present a model in which strings are allowed to combine into higher multiplets, giving rise to increased production of baryons and strangeness, or recombine into singlet structures and vanish. Also a crude model for strings recombining into junction structures is considered, again giving rise to increased baryon production. The models are implemented in the DIPSY MC event generator, using PYTHIA8 for hadronization, and comparison to pp minimum bias data, reveals improvement in the description of identified particle spectra.« less

  1. Continuum percolation of congruent overlapping spherocylinders

    NASA Astrophysics Data System (ADS)

    Xu, Wenxiang; Su, Xianglong; Jiao, Yang

    2016-09-01

    Continuum percolation of randomly orientated congruent overlapping spherocylinders (composed of cylinder of height H with semispheres of diameter D at the ends) with aspect ratio α =H /D in [0 ,∞ ) is studied. The percolation threshold ϕc, percolation transition width Δ, and correlation-length critical exponent ν for spherocylinders with α in [0, 200] are determined with a high degree of accuracy via extensive finite-size scaling analysis. A generalized excluded-volume approximation for percolation threshold with an exponent explicitly depending on both aspect ratio and excluded volume for arbitrary α values in [0 ,∞ ) is proposed and shown to yield accurate predictions of ϕc for an extremely wide range of α in [0, 2000] based on available numerical and experimental data. We find ϕc is a universal monotonic decreasing function of α and is independent of the effective particle size. Our study has implications in percolation theory for nonspherical particles and composite material design.

  2. Base drive and overlap protection circuit

    DOEpatents

    Gritter, David J.

    1983-01-01

    An inverter (34) which provides power to an A. C. machine (28) is controlled by a circuit (36) employing PWM control strategy whereby A. C. power is supplied to the machine at a preselectable frequency and preselectable voltage. This is accomplished by the technique of waveform notching in which the shapes of the notches are varied to determine the average energy content of the overall waveform. Through this arrangement, the operational efficiency of the A. C. machine is optimized. The control circuit includes a microcomputer and memory element which receive various parametric inputs and calculate optimized machine control data signals therefrom. The control data is asynchronously loaded into the inverter through an intermediate buffer (38). A base drive and overlap protection circuit is included to insure that both transistors of a complimentary pair are not conducting at the same time. In its preferred embodiment, the present invention is incorporated within an electric vehicle (10) employing a 144 VDC battery pack (32) and a three-phase induction motor (18).

  3. Effects of overlapping strings in pp collisions

    SciTech Connect

    Bierlich, Christian; Gustafson, Gösta; Lönnblad, Leif; Tarasov, Andrey

    2015-03-26

    In models for hadron collisions based on string hadronization, the strings are usually treated as independent, allowing no interaction between the confined colour fields. In studies of nucleus collisions it has been suggested that strings close in space can fuse to form "colour ropes." Such ropes are expected to give more strange particles and baryons, which also has been suggested as a signal for plasma formation. Overlapping strings can also be expected in pp collisions, where usually no phase transition is expected. In particular at the high LHC energies the expected density of strings is quite high. To investigate possible effects of rope formation, we present a model in which strings are allowed to combine into higher multiplets, giving rise to increased production of baryons and strangeness, or recombine into singlet structures and vanish. Also a crude model for strings recombining into junction structures is considered, again giving rise to increased baryon production. The models are implemented in the DIPSY MC event generator, using PYTHIA8 for hadronization, and comparison to pp minimum bias data, reveals improvement in the description of identified particle spectra.

  4. Analysis of radial and longitudinal force of plasma wakefield generated by a chirped pulse laser

    SciTech Connect

    Ghasemi, Leila; Afhami, Saeedeh; Eslami, Esmaeil

    2015-08-15

    In present paper, the chirp effect of an electromagnetic pulse via an analytical model of wakefield generation is studied. Different types of chirps are employed in this study. Our results show that by the use of nonlinear chirped pulse the longitudinal wakefield and focusing force is stronger than that of linear chirped pulse. It is indicated that quadratic nonlinear chirped pulses are globally much efficient than periodic nonlinear chirped pulses. Our calculations also predict that in nonlinear chirped pulse case, the overlap of focusing and accelerating regions is broader than that achieved in linear chirped pulse.

  5. Sensitivity enhancement through overlapping simultaneously excited Fano resonance modes of metallic-photonic-crystal sensors.

    PubMed

    Zhang, Jian; Zhang, Xinping; Su, Xueqiong; Lu, Yi; Feng, Shengfei; Wang, Li

    2014-02-10

    We investigated enhancement of sensitivity of sensors based on metallic photonic crystals through tuning the thickness of the waveguide layer by pulsed laser deposition. Thicker waveguides made of InGaZnO allow double resonance of Fano coupling modes due to plasmonic-photonic interactions. Tuning the angle of incidence enables overlap between these doubly resonant modes, which induces much enlarged and spectrally narrowed sensor signals, leading to significantly enhanced sensitivity of the sensor device. The thickness of the waveguide layer is found to be a crucial structural parameter to improve sensitivity of the MPC sensors. PMID:24663620

  6. A real-time pulsed photon dosimeter

    NASA Astrophysics Data System (ADS)

    Brown, David; Olsher, Richard H.; Eisen, Yosef; Rodriguez, Joseph F.

    1996-02-01

    Radiation sources producing short pulses of photon radiation are now widespread. Such sources include electron and proton linear accelerators, betatrons, synchrotrons, and field-emission impulse generators. It is often desirable to measure leakage and skyshine radiation from such sources in real time, on a single-pulse basis as low as 8.7 nGy (1 μR) per pulse. This paper describes the design and performance of a prototype, real-time, pulsed photon dosimeter (PPD) capable of single-pulse dose measurements over the range from 3.5 nGy to 3.5 μGy (0.4 to 400 μR). The PPD may also be operated in a multiple-pulse mode that integrates the dose from a train of radiation pulses over a 3-s period. A pulse repetition rate of up to 300 Hz is accommodated. The design is eminently suitable for packaging as a lightweight, portable, survey meter. The PPD uses a CdWO 4 scintillator optically coupled to a photodiode to generate a charge at the diode output. A pulse amplifier converts the charge to a voltage pulse. A digitizer circuit generates a burst of logic pulses whose number is proportional to the peak value of the voltage pulse. The digitizer output is recorded by a pulse counter and suitably displayed. A prototype PPD was built for testing and evaluation purposes. The performance of the PPD was evaluated with a variety of pulsed photon sources. The dynamic range, energy response, and response to multiple pulses were characterized. The experimental data confirm the viability of the PPD for pulsed photon dosimetry.

  7. Combinatorial gene regulation by modulation of relative pulse timing

    PubMed Central

    Lin, Yihan; Sohn, Chang Ho; Dalal, Chiraj K.; Cai, Long; Elowitz, Michael B.

    2015-01-01

    Studies of individual living cells have revealed that many transcription factors activate in dynamic, and often stochastic, pulses within the same cell. However, it has remained unclear whether cells might modulate the relative timing of these pulses to control gene expression. Here, using quantitative single-cell time-lapse imaging of Saccharomyces cerevisiae, we show that the pulsatile transcription factors Msn2 and Mig1 combinatorially regulate their target genes through modulation of their relative pulse timing. The activator Msn2 and repressor Mig1 pulsed in either a temporally overlapping or non-overlapping manner during their transient response to different inputs, with only the non-overlapping dynamics efficiently activating target gene expression. Similarly, under constant environmental conditions, where Msn2 and Mig1 exhibit sporadic pulsing, glucose concentration modulated the temporal overlap between pulses of the two factors. Together, these results reveal a time-based mode of combinatorial gene regulation. Regulation through relative signal timing is common in engineering and neurobiology, and these results suggest that it could also function broadly within the signaling and regulatory systems of the cell. PMID:26466562

  8. A Case of Reticulate Acropigmentation of Kitamura: Dowling Degos Disease Overlap with Unusual Clinical Manifestations

    PubMed Central

    Vasudevan, Biju; Verma, Rajesh; Badwal, Sonia; Pragasam, Vijendran; Moorchung, Nikhil; Badad, Ambresh

    2014-01-01

    Reticulate hyperpigmentary disorders are a group of rare genetic pigmentary abnormalities which includes reticulate acropigmentation of Kitamura (RAPK), Dowling-Degos disease (DD), reticulate acropigmentation of Dohi (RAPD), Haber's syndrome, and Galli-Galli disease. A 25-year-old male presented with asymptomatic dark-colored lesions on his hands and feet with light-colored skin lesions involving the trunk since three years. Dermatological examination revealed hyperpigmented macules in a reticulate pattern involving the dorsa of the hands and feet, front and sides of the neck, axillae, periorbital region, and groin. Multiple pits were present over both palms, with breaks in dermatoglyphics. He also had multiple nonacne facial scars predominantly on the nose and malar areas. The patient had overlapping features of RAPK and DDD. In addition, he also had hypopigmented macules and acneiform facial scars. Such an overlap of features of reticulate pigmentation has not been previously reported in the literature. PMID:24891663

  9. A Lower Bound for Quantifying Overlap Effects: An Empirical Approach

    SciTech Connect

    Bassetti, Federico

    1997-12-31

    Among the many features that are implemented in today`s microprocessors there are some that have the capability of reducing the execution time via overlapping of different operations. Overlapping of instructions with other instructions, and overlapping of computation with memory activities are the main way in which execution time is reduced. In this paper we will introduce a notion of overlap and its definition, and a few different ways to capture its effects. We will characterize some of the DOE Accelerated Strategic Computing Initiative (ASCI) benchmarks using the overlap and some other quantities related to it. Also, we will present a characterization of the overlap effects using a lower bound derived empirically from measured data. We will conclude by using the lower bound to estimate other components of the overall execution time.

  10. PULSE COUNTER

    DOEpatents

    Trumbo, D.E.

    1959-02-10

    A transistorized pulse-counting circuit adapted for use with nuclear radiation detecting detecting devices to provide a small, light weight portable counter is reported. The small size and low power requirements of the transistor are of particular value in this instance. The circuit provides an adjustable count scale with a single transistor which is triggered by the accumulated charge on a storage capacitor.

  11. Noninvasive pulsed focused ultrasound allows spatiotemporal control of targeted homing for multiple stem cell types in murine skeletal muscle and the magnitude of cell homing can be increased through repeated applications

    PubMed Central

    Burks, Scott R.; Ziadloo, Ali; Kim, Saejeong J.; Nguyen, Ben A.; Frank, Joseph A.

    2013-01-01

    Stem cells are promising therapeutics for cardiovascular diseases and intravenous injection is the most desirable route of administration clinically. Subsequent homing of exogenous stem cells to pathological loci is frequently required for therapeutic efficacy and is mediated by chemo attractants (cell adhesion molecules, cytokines, and growth factors). Homing processes are inefficient and depend on short-lived pathological inflammation that limits the window of opportunity for cell injections. Noninvasive pulsed focused ultrasound (plus), which emphasizes mechanical ultrasound-tissue interactions, can be precisely targeted in the body and is a promising approach to target and maximize stem cell delivery by stimulating chemo attractant expression in plus-treated tissue prior to cell infusions. We demonstrate that plus is nondestructive to marine skeletal muscle tissue (no necrosis, hemorrhage, or muscle stem cell activation) and initiates a largely M2-type macrophage response. We also demonstrate local up regulation of chemo attractants in plus-treated skeletal muscle leads to enhance homing, permeability, and retention of human mesenchymal stem cells (MSC) and human endothelial precursor cells (EPC). Furthermore, the magnitude of MSC or EPC homing was increased when plus treatments and cell infusions were repeated daily. This study demonstrates that plus defines transient “molecular zip codes” of elevated chemo attractants in targeted muscle tissue, which effectively provides spatiotemporal control and tenability of the homing process for multiple stem cell types. plus is a clinically-translatable modality that may ultimately improve homing efficiency and flexibility of cell therapies for cardiovascular diseases. PMID:23922277

  12. An unusual presentation of Kabuki syndrome: clinical overlap with CHARGE syndrome.

    PubMed

    Verhagen, Judith M A; Oostdijk, Wilma; Terwisscha van Scheltinga, Cecilia E J; Schalij-Delfos, Nicoline E; van Bever, Yolande

    2014-09-01

    Kabuki syndrome is a rare genetic disorder characterized by intellectual disability and multiple congenital anomalies, including short stature, peculiar facial appearance, skeletal anomalies, a variety of visceral malformations and abnormal dermatoglyphic patterns. We describe a case of Kabuki syndrome presenting with atypical features, consisting of bilateral microphthalmia, coloboma, anal atresia and panhypopituitarism, showing considerable phenotypic overlap with CHARGE syndrome. This report demonstrates that clinical follow-up and molecular genetic testing can be useful for establishing the correct diagnosis. PMID:24862881

  13. Use of overlapping buccal mucosa graft urethroplasty for complex anterior urethral strictures

    PubMed Central

    2015-01-01

    Complex anterior urethral stricture disease typically manifests as a symptomatic, severely narrowed, long stricture (or multiple strictures) in which conventional excision and/or augmentation is not feasible. Overlapping buccal mucosal graft urethroplasty (OBMGU) is an innovative hybrid technique, combining the well-established principles of dorsal and ventral graft augmentation to allow single stage reconstruction of complex anterior urethral strictures. In this review, we discuss the rationale, techniques, and outcomes of OBMGU for complex anterior urethral strictures. PMID:26813234

  14. Solving Fluid Flow Problems on Moving and Adaptive Overlapping Grids

    SciTech Connect

    Henshaw, W

    2005-07-28

    Solution of fluid dynamics problems on overlapping grids will be discussed. An overlapping grid consists of a set of structured component grids that cover a domain and overlap where they meet. Overlapping grids provide an effective approach for developing efficient and accurate approximations for complex, possibly moving geometry. Topics to be addressed include the reactive Euler equations, the incompressible Navier-Stokes equations and elliptic equations solved with a multigrid algorithm. Recent developments coupling moving grids and adaptive mesh refinement and preliminary parallel results will also be presented.

  15. DNA statistics, overlapping word paradox and Conway equation

    SciTech Connect

    Pevzner, P.A.

    1993-12-31

    Overlapping word paradox known in combinatorics for 20 years is to this day disregarded in many papers on DNA statistics. The author considers Conway equation for the best bet for simpletons as an example of the overlapping word paradox. He gives a new short proof of Conway equation and discusses the implications of the overlapping word paradox for DNA statistics. In particular, he demonstrates that ignoring overlapping word paradox in DNA statistics can easily lead to 500% mistakes in estimations of statistical significance. He also presents formulas allowing one to find `anomalous` words in DNA texts.

  16. Dynamic analysis of piping using the structural overlap method

    SciTech Connect

    Curreri, J.; Bezler, P.; Hartzman, M.

    1981-03-01

    The structural overlap method is a procedure for analyzing the dynamic response of a piping system by performing a separate analysis on subsystems of the complete structure. Specific cases were investigated to obtain an estimate of the validity and application of the method. The case studies were increased in complexity in order to examine some of the problems involved in implementing the method. It is concluded that the overlap method should not be substituted for a complete analysis of a full system. However, if a sufficiently high natural frequency is associated with the overlap section or the overlap section is a substantial portion of the system, acceptable results could be obtained.

  17. Pulse-echo interaction in free-flying horseshoe bats, Rhinolophus ferrumequinum nippon.

    PubMed

    Shiori, Yu; Hiryu, Shizuko; Watanabe, Yu; Riquimaroux, Hiroshi; Watanabe, Yoshiaki

    2009-09-01

    Because horseshoe bats emit a long-duration pulse, the returning echo temporally overlaps with the emitted pulse during echolocation. Here, the pulse-echo interaction that horseshoe bats actually experience during flight was examined using onboard telemetry sound recordings. Doppler-shifted returning echoes produced beats in the amplitude patterns of constant-frequency components. Bats shortened the pulse duration with target distance, but the overlap duration was at least 8 ms within the approach phase. The computations suggest that the phase difference in slowly amplitude-modulated sound (the beat signal) provides a useful cue for target localization.

  18. Multiple acousto-optic q-switch

    SciTech Connect

    Deason, Vance A.

    1993-01-01

    An improved dynamic moire interferometer comprised of a lasing medium providing a plurality of beams of coherent light, a multiple q-switch producing multiple trains of 100,000 or more pulses per second, a combining means collimating multiple trains of pulses into substantially a single train and directing beams to specimen gratings affixed to a test material, and a controller, triggering and sequencing the emission of the pulses with the occurrence and recording of a dynamic loading event.

  19. Multiple acousto-optic q-switch

    SciTech Connect

    Deason, Vance A.

    1993-12-07

    An improved dynamic moire interferometer comprised of a lasing medium providing a plurality of beams of coherent light, a multiple q-switch producing multiple trains of 100,000 or more pulses per second, a combining means collimating multiple trains of pulses into substantially a single train and directing beams to specimen gratings affixed to a test material, and a controller, triggering and sequencing the emission of the pulses with the occurrence and recording of a dynamic loading event.

  20. Pulsed hydrojet

    DOEpatents

    Bohachevsky, I.O.; Torrey, M.D.

    1986-06-10

    An underwater pulsed hydrojet propulsion system is provided for accelerating and propelling a projectile or other vessel. A reactant, such as lithium, is fluidized and injected into a water volume. The resulting reaction produces an energy density in a time effective to form a steam pocket. Thrust flaps or baffles direct the pressure from the steam pocket toward an exit nozzle for accelerating a water volume to create thrust. A control system regulates the dispersion of reactant to control thrust characteristics.

  1. Spousal Network Overlap as a Basis for Spousal Support

    ERIC Educational Resources Information Center

    Cornwell, Benjamin

    2012-01-01

    The role social network structure plays in facilitating flows of support between spouses is often overlooked. This study examined whether levels of support between spouses depended on the degree of overlap between spouses' networks. Network overlap may enhance spouses' support capacities by increasing their understanding of each other's support…

  2. A reexamination of the small overlap frontal crash.

    PubMed

    Scullion, Paul; Morgan, Richard M; Mohan, Pradeep; Kan, Cing-Dao; Shanks, Kurt; Jin, Wook; Tangirala, Ravi

    2010-01-01

    The objective of this study was to examine and rank the Small Overlap Frontal Crash as one of the eight-group taxonomy proposed by Ford. The Ford taxonomy classifies real-world frontal-impact crashes based on the National Automotive Sampling System (NASS). Frontally-impacted vehicles were identified for 1985 - 2008 model year passenger vehicles with Collision Deformation Classification (CDC) data from the 1995 - 2008 years of NASS. Small overlap frontal cases were identified where there was no engagement of the vehicle frame rails, and the direct damage was located entirely outside of the vehicle frame rails. The results are that full engagement and offset (offset category means the direct damage overlaps the vehicle frame rail, with the center of direct damage between the frame rails) were the most frequent crashes contributing 35% each. The frequency of the small overlap frontal was 6%. The risks of injury (AIS ≥ 2) for the full engagement, offset, and small overlap were 8%, 6%, and 3% respectively. For this study, the number of small overlap vehicles was 1,118 and the number of injured nearside occupants was 100. This study-following the Ford approach and reasonably identifying the location of the longitudinal rails based on CDC-suggests that the small overlap is at worst a moderately dangerous crash in the overall scheme of frontal crashes. The implications of this study are that the safety community should reexamine the significance of the small overlap frontal crash against an overall taxonomy of crashes. PMID:21050598

  3. Overlaps and Accumulation in the Use of Rehabilitation Services

    ERIC Educational Resources Information Center

    Pulkki, Jutta M.; Rissanen, Pekka; Raitanen, Jani A.; Viitanen, Elina A.

    2011-01-01

    The Finnish rehabilitation system is considered fragmented and multisectoral, and thus it may produce "multiclients" receiving inefficient and overlapping services. This paper addresses the overlaps and accumulation in the delivery of rehabilitation services in Finnish rehabilitation subsystems. Data were drawn from several administrative…

  4. Shake for Sigma, Pray for Pi: Classroom Orbital Overlap Analogies

    ERIC Educational Resources Information Center

    Dicks, Andrew P.

    2011-01-01

    An introductory organic classroom demonstration is discussed where analogies are made between common societal hand contact and covalent bond formation. A handshake signifies creation of a [sigma] bond ("head-on" orbital overlap), whereas the action of praying illustrates "sideways" overlap and generation of a [pi] bond. The nature of orbital and…

  5. An Exposition of Fischer's Model of Overlapping Contracts.

    ERIC Educational Resources Information Center

    Fields, T. Windsor; Hart, William R.

    1992-01-01

    Suggests how the classic model of overlapping contracts can be incorporated into the contract wage model of aggregate supply. Illustrates dynamics of macroeconomic adjustment following a shock to aggregate demand. Concludes that overlapping contracts do not prolong the adjustment process; rather, the longest remaining contract determines the time…

  6. Overlap loss of manually and automatically guided mowers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Overlap loss in harvesting machinery has been observed as a necessary inefficiency for many years. Each time a non-row-crop machine makes a pass in the field, it is favorable for the operator to overlap slightly into the previous pass (where the crop has already been cut), as opposed to undercutting...

  7. Multiple Database Searching: Techniques and Pitfalls

    ERIC Educational Resources Information Center

    Hawkins, Donald T.

    1978-01-01

    Problems involved in searching multiple data bases are discussed including indexing differences, overlap among data bases, variant spellings, and elimination of duplicate items from search output. Discussion focuses on CA Condensates, Inspec, and Metadex data bases. (J PF)

  8. Pulse transmission transceiver architecture for low power communications

    DOEpatents

    Dress, Jr., William B.; Smith, Stephen F.

    2003-08-05

    Systems and methods for pulse-transmission low-power communication modes are disclosed. A method of pulse transmission communications includes: generating a modulated pulse signal waveform; transforming said modulated pulse signal waveform into at least one higher-order derivative waveform; and transmitting said at least one higher-order derivative waveform as an emitted pulse. The systems and methods significantly reduce lower-frequency emissions from pulse transmission spread-spectrum communication modes, which reduces potentially harmful interference to existing radio frequency services and users and also simultaneously permit transmission of multiple data bits by utilizing specific pulse shapes.

  9. The Pulse Line Ion Accelerator Concept

    SciTech Connect

    Briggs, Richard J.

    2006-02-15

    The Pulse Line Ion Accelerator concept was motivated by the desire for an inexpensive way to accelerate intense short pulse heavy ion beams to regimes of interest for studies of High Energy Density Physics and Warm Dense Matter. A pulse power driver applied at one end of a helical pulse line creates a traveling wave pulse that accelerates and axially confines the heavy ion beam pulse. Acceleration scenarios with constant parameter helical lines are described which result in output energies of a single stage much larger than the several hundred kilovolt peak voltages on the line, with a goal of 3-5 MeV/meter acceleration gradients. The concept might be described crudely as an ''air core'' induction linac where the PFN is integrated into the beam line so the accelerating voltage pulse can move along with the ions to get voltage multiplication.

  10. Instrument Identification in Polyphonic Music: Feature Weighting to Minimize Influence of Sound Overlaps

    NASA Astrophysics Data System (ADS)

    Kitahara, Tetsuro; Goto, Masataka; Komatani, Kazunori; Ogata, Tetsuya; Okuno, Hiroshi G.

    2006-12-01

    We provide a new solution to the problem of feature variations caused by the overlapping of sounds in instrument identification in polyphonic music. When multiple instruments simultaneously play, partials (harmonic components) of their sounds overlap and interfere, which makes the acoustic features different from those of monophonic sounds. To cope with this, we weight features based on how much they are affected by overlapping. First, we quantitatively evaluate the influence of overlapping on each feature as the ratio of the within-class variance to the between-class variance in the distribution of training data obtained from polyphonic sounds. Then, we generate feature axes using a weighted mixture that minimizes the influence via linear discriminant analysis. In addition, we improve instrument identification using musical context. Experimental results showed that the recognition rates using both feature weighting and musical context were 84.1[InlineEquation not available: see fulltext.] for duo, 77.6[InlineEquation not available: see fulltext.] for trio, and 72.3[InlineEquation not available: see fulltext.] for quartet; those without using either were 53.4, 49.6, and 46.5[InlineEquation not available: see fulltext.], respectively.

  11. Megavolt, Multigigawatt Pulsed Plasma Switch

    NASA Technical Reports Server (NTRS)

    Lee, Ja H.; Choi, Sang H.; Song, Kyo D.

    1996-01-01

    Plasma switch proposed for use in high-voltage, high-current pulse power system. Designed not only to out-perform conventional spark-gap switch but also relatively compact and lightweight. Features inverse-pinch configuration to prevent constriction of current sheets into filaments, plus multiple-ring-electrode structure to resist high-voltage breakdown.

  12. Design of a wavelength frame multiplication system using acceptance diagrams

    NASA Astrophysics Data System (ADS)

    Nekrassov, D.; Zendler, C.; Lieutenant, K.

    2013-07-01

    The concept of Wavelength Frame Multiplication (WFM) was developed to extend the usable wavelength range on long pulse neutron sources for instruments using pulse shaping choppers. For some instruments, it is combined with a pulse shaping double chopper, which defines a constant wavelength resolution, and a set of frame overlap choppers that prevent spurious neutrons from reaching the detector thus avoiding systematic errors in the calculation of wavelength from time of flight. Due to its complexity, the design of such a system is challenging and there are several criteria that need to be accounted for. In this work, the design of the WFM chopper system for a potential future liquids reflectometer at the European Spallation Source (ESS) is presented, which makes use of acceptance diagrams. They prove to be a powerful tool for understanding the work principle of the system and recognizing potential problems. The authors assume that the presented study can be useful for design or upgrade of further instruments, in particular the ones planned for the ESS.

  13. Arterial Transit Time Mapping Obtained by Pulsed Continuous 3D ASL Imaging with Multiple Post-Label Delay Acquisitions: Comparative Study with PET-CBF in Patients with Chronic Occlusive Cerebrovascular Disease

    PubMed Central

    Tsujikawa, Tetsuya; Kimura, Hirohiko; Matsuda, Tsuyoshi; Fujiwara, Yasuhiro; Isozaki, Makoto; Kikuta, Ken-ichiro; Okazawa, Hidehiko

    2016-01-01

    Arterial transit time (ATT) is most crucial for measuring absolute cerebral blood flow (CBF) by arterial spin labeling (ASL), a noninvasive magnetic resonance (MR) perfusion assessment technique, in patients with chronic occlusive cerebrovascular disease. We validated ASL-CBF and ASL-ATT maps calculated by pulsed continuous ASL (pCASL) with multiple post-label delay acquisitions in patients with occlusive cerebrovascular disease. Fifteen patients underwent MR scans, including pCASL, and positron emission tomography (PET) scans with 15O-water to obtain PET-CBF. MR acquisitions with different post-label delays (1.0, 1.5, 2.0, 2.5 and 3.0 sec) were also obtained for ATT correction. The theoretical framework of 2-compartmental model (2CM) was also used for the delay compensation. ASL-CBF and ASL-ATT were calculated based on the proposed 2CM, and the effect on the CBF values and the ATT correction characteristics were discussed. Linear regression analyses were performed both on pixel-by-pixel and region-of-interest bases in the middle cerebral artery (MCA) territory. There were significant correlations between ASL-CBF and PET-CBF both for voxel values (r = 0.74 ± 0.08, slope: 0.87 ± 0.22, intercept: 6.1 ± 4.9) and for the MCA territorial comparison in both affected (R2 = 0.67, y = 0.83x + 6.3) and contralateral sides (R2 = 0.66, y = 0.74x + 6.3). ASL-ATTs in the affected side were significantly longer than those in the contralateral side (1.51 ± 0.41 sec and 1.12 ± 0.30 sec, respectively, p <0.0005). CBF measurement using pCASL with delay compensation was feasible and fairly accurate even in altered hemodynamic states. PMID:27275779

  14. An extension to artifact-free projection overlaps

    SciTech Connect

    Lin, Jianyu

    2015-05-15

    Purpose: In multipinhole single photon emission computed tomography, the overlapping of projections has been used to increase sensitivity. Avoiding artifacts in the reconstructed image associated with projection overlaps (multiplexing) is a critical issue. In our previous report, two types of artifact-free projection overlaps, i.e., projection overlaps that do not lead to artifacts in the reconstructed image, were formally defined and proved, and were validated via simulations. In this work, a new proposition is introduced to extend the previously defined type-II artifact-free projection overlaps so that a broader range of artifact-free overlaps is accommodated. One practical purpose of the new extension is to design a baffle window multipinhole system with artifact-free projection overlaps. Methods: First, the extended type-II artifact-free overlap was theoretically defined and proved. The new proposition accommodates the situation where the extended type-II artifact-free projection overlaps can be produced with incorrectly reconstructed portions in the reconstructed image. Next, to validate the theory, the extended-type-II artifact-free overlaps were employed in designing the multiplexing multipinhole spiral orbit imaging systems with a baffle window. Numerical validations were performed via simulations, where the corresponding 1-pinhole nonmultiplexing reconstruction results were used as the benchmark for artifact-free reconstructions. The mean square error (MSE) was the metric used for comparisons of noise-free reconstructed images. Noisy reconstructions were also performed as part of the validations. Results: Simulation results show that for noise-free reconstructions, the MSEs of the reconstructed images of the artifact-free multiplexing systems are very similar to those of the corresponding 1-pinhole systems. No artifacts were observed in the reconstructed images. Therefore, the testing results for artifact-free multiplexing systems designed using the

  15. Plasma Membrane Permeabilization by Trains of Ultrashort Electric Pulses

    PubMed Central

    Ibey, Bennett L.; Mixon, Dustin G.; Payne, Jason A.; Bowman, Angela; Sickendick, Karl; Wilmink, Gerald J.; Roach, W. Patrick; Pakhomov, Andrei G.

    2010-01-01

    Ultrashort electric pulses (USEP) cause long-lasting increase of cell membrane electrical conductance, and that a single USEP increased cell membrane electrical conductance proportionally to the absorbed dose (AD) with a threshold of about 10 mJ/g. The present study extends quantification of the membrane permeabilization effect to multiple USEP and employed a more accurate protocol that identified USEP effect as the difference between post- and pre-exposure conductance values (Δg) in individual cells. We showed that Δg can be increased by either increasing the number of pulses at a constant E-field, or by increasing the E-field at a constant number of pulses. For 60-ns pulses, an E-field threshold of 6 kV/cm for a single pulse was lowered to less than 1.7 kV/cm by applying 100-pulse or longer trains. However, the reduction of the E-field threshold was only achieved at the expense of a higher AD compared to a single pulse exposure. Furthermore, the effect of multiple pulses was not fully determined by AD, suggesting that cells permeabilized by the first pulse(s) in the train become less vulnerable to subsequent pulses. This explanation was corroborated by a model that treated multiple-pulse exposures as a series of single-pulse exposures and assumed an exponential decline of cell susceptibility to USEP as Δg increased after each pulse during the course of the train. PMID:20171148

  16. PULSE COLUMN

    DOEpatents

    Grimmett, E.S.

    1964-01-01

    This patent covers a continuous countercurrent liquidsolids contactor column having a number of contactor states each comprising a perforated plate, a layer of balls, and a downcomer tube; a liquid-pulsing piston; and a solids discharger formed of a conical section at the bottom of the column, and a tubular extension on the lowest downcomer terminating in the conical section. Between the conical section and the downcomer extension is formed a small annular opening, through which solids fall coming through the perforated plate of the lowest contactor stage. This annular opening is small enough that the pressure drop thereacross is greater than the pressure drop upward through the lowest contactor stage. (AEC)

  17. Overlapping verbal, relational, physical, and electronic forms of bullying in adolescence: influence of school context.

    PubMed

    Bradshaw, Catherine P; Waasdorp, Tracy Evian; Johnson, Sarah Lindstrom

    2015-01-01

    Interest in youths' experience of the various forms of bullying has grown due to the numerous social-emotional correlates associated with bullying. Only recently has there been consideration of the school context in light of these associations. The current study examined the overlap in four different forms of bullying that youth commonly experience (i.e., verbal, relational, physical, electronic), with the aim of understanding their association with social-emotional correlates (i.e., internalizing symptoms, externalizing symptoms, retaliatory attitudes) and exploring associations with school contextual factors such as supervision, school physical disorder, and behavioral expectations. Self-report data on the forms of peer bullying were collected from 24,620 adolescents (Grades 9-12; M age = 15.98, SD age = 1.32) enrolled in 52 high schools. Latent class analyses indicated significant overlap in the different forms of bullying victimization, with youth experiencing multiple forms of bullying reporting the greatest risk for social-emotional problems. A series of two-level hierarchical linear models revealed that indicators of school physical disorder and a lack of positive behavioral expectations were associated with increased risk for multiple forms of bullying. Several gender and age differences were also observed in relation to the patterns of bullying experienced. These findings extend prior research by emphasizing a potential link between the overlap in different forms of bullying and school contextual factors, even after controlling for individual-level risk factors.

  18. Space-use scaling and home range overlap in primates

    PubMed Central

    Pearce, Fiona; Carbone, Chris; Cowlishaw, Guy; Isaac, Nick J. B.

    2013-01-01

    Space use is an important aspect of animal ecology, yet our understanding is limited by a lack of synthesis between interspecific and intraspecific studies. We present analyses of a dataset of 286 estimates of home range overlap from 100 primate species, with comparable samples for other space-use traits. To the best of our knowledge, this represents the first multispecies study using overlap data estimated directly from field observations. We find that space-use traits in primates are only weakly related to body mass, reflecting their largely arboreal habits. Our results confirm a theory that home range overlap explains the differences in allometric scaling between population density and home range size. We then test a suite of hypotheses to explain home range overlap, both among and within species. We find that overlap is highest for larger-bodied species living in large home ranges at high population densities, where annual rainfall is low, and is higher for arboreal than terrestrial species. Most of these results are consistent with the economics of resource defence, although the predictions of one specific theory of home range overlap are not supported. We conclude that home range overlap is somewhat predictable, but the theoretical basis of animal space use remains patchy. PMID:23193124

  19. Tapered pulse tube for pulse tube refrigerators

    DOEpatents

    Swift, Gregory W.; Olson, Jeffrey R.

    1999-01-01

    Thermal insulation of the pulse tube in a pulse-tube refrigerator is maintained by optimally varying the radius of the pulse tube to suppress convective heat loss from mass flux streaming in the pulse tube. A simple cone with an optimum taper angle will often provide sufficient improvement. Alternatively, the pulse tube radius r as a function of axial position x can be shaped with r(x) such that streaming is optimally suppressed at each x.

  20. How to decontaminate overlapping fat jets

    NASA Astrophysics Data System (ADS)

    Hamaguchi, Koichi; Liew, Seng Pei; Stoll, Martin

    2015-07-01

    At the LHC, tagging boosted heavy particle resonances which decay hadronically, such as top quarks and Higgs bosons, can play an essential role in new physics searches. In events with high multiplicity, however, the standard approach to tag boosted resonances by a large-radius fat jet becomes difficult because the resonances are not well separated from other hard radiation. In this paper, we propose a different approach to tag and reconstruct boosted resonances by using the recently proposed mass-jump jet algorithm. A key feature of the algorithm is the flexible radius of the jets, which results from a terminating veto that prevents the recombination of two hard prongs if their combined jet mass is substantially larger than the masses of the separate prongs. The idea of collecting jets in "buckets" is also used. As an example, we consider the fully hadronic final state of pair-produced vectorlike top partners at the LHC, p p →T T ¯→t t ¯H H , and show that the new approach works well. We also show that tagging and kinematic reconstruction of boosted top quarks and Higgs bosons are possible with good quality even in these very busy final states. The vectorlike top partners are kinematically reconstructed, which allows their direct mass measurement.

  1. Overlap Properties of Clouds Generated by a Cloud Resolving Model

    NASA Technical Reports Server (NTRS)

    Oreopoulos, L.; Khairoutdinov, M.

    2002-01-01

    In order for General Circulation Models (GCMs), one of our most important tools to predict future climate, to correctly describe the propagation of solar and thermal radiation through the cloudy atmosphere a realistic description of the vertical distribution of cloud amount is needed. Actually, one needs not only the cloud amounts at different levels of the atmosphere, but also how these cloud amounts are related, in other words, how they overlap. Currently GCMs make some idealized assumptions about cloud overlap, for example that contiguous cloud layers overlap maximally and non-contiguous cloud layers overlap in a random fashion. Since there are difficulties in obtaining the vertical profile of cloud amount from observations, the realism of the overlap assumptions made in GCMs has not been yet rigorously investigated. Recently however, cloud observations from a relatively new type of ground radar have been used to examine the vertical distribution of cloudiness. These observations suggest that the GCM overlap assumptions are dubious. Our study uses cloud fields from sophisticated models dedicated to simulate cloud formation, maintenance, and dissipation called Cloud Resolving Models . These models are generally considered capable of producing realistic three-dimensional representation of cloudiness. Using numerous cloud fields produced by such a CRM we show that the degree of overlap between cloud layers is a function of their separation distance, and is in general described by a combination of the maximum and random overlap assumption, with random overlap dominating as separation distances increase. We show that it is possible to parameterize this behavior in a way that can eventually be incorporated in GCMs. Our results seem to have a significant resemblance to the results from the radar observations despite the completely different nature of the datasets. This consistency is encouraging and will promote development of new radiative transfer codes that will

  2. Phase-space overlap measures. II. Design and implementation of staging methods for free-energy calculations.

    PubMed

    Wu, Di; Kofke, David A

    2005-08-22

    We consider staged free-energy calculation methods in the context of phase-space overlap relations, and argue that the selection of work-based methods should be guided by consideration of the phase-space overlap of the systems of interest. Stages should always be constructed such that work is performed only into a system that has a phase-space subset relation with the starting system. Thus multiple stages are required if the systems of interest are not such that one forms a phase-space subset with the other. Three two-stage methods are possible, termed umbrella sampling, overlap sampling, and funnel sampling. The last is appropriate for cases in which the subset relation holds, but only in the extreme, meaning that one system's important phase space constitutes a very small portion of the others. Umbrella sampling is most suitable for nonoverlap systems, and overlap sampling is appropriate for systems exhibiting partial phase-space overlap. We review recently introduced metrics that characterize phase-space overlap, showing that the performance of the single- and two-stage methods is consistent with the phase-space picture. We also demonstrate that a recently introduced bias-detection measure is effective in identifying inaccuracy in single- and multistage calculations. The examples used are the chemical-potential calculation for a Lennard-Jones liquid at moderate and at high densities, the same for model water at ambient conditions, and a process of charging a neutral ion in water.

  3. A Guide to Using STITCHER for Overlapping Assembly PCR Applications.

    PubMed

    O'Halloran, Damien M

    2017-01-01

    Overlapping PCR is commonly used in many molecular applications that include stitching PCR fragments together, generating fluorescent transcriptional and translational fusions, inserting mutations, making deletions, and PCR cloning. Overlapping PCR is also used for genotyping and in detection experiments using techniques such as loop-mediated isothermal amplification (LAMP). STITCHER is a web tool providing a central resource for researchers conducting all types of overlapping assembly PCR experiments with an intuitive interface for automated primer design that's fast, easy to use, and freely available online. PMID:27671928

  4. A Guide to Using STITCHER for Overlapping Assembly PCR Applications.

    PubMed

    O'Halloran, Damien M

    2017-01-01

    Overlapping PCR is commonly used in many molecular applications that include stitching PCR fragments together, generating fluorescent transcriptional and translational fusions, inserting mutations, making deletions, and PCR cloning. Overlapping PCR is also used for genotyping and in detection experiments using techniques such as loop-mediated isothermal amplification (LAMP). STITCHER is a web tool providing a central resource for researchers conducting all types of overlapping assembly PCR experiments with an intuitive interface for automated primer design that's fast, easy to use, and freely available online.

  5. Overlap Correction Function For an Airborne Based Lidar

    NASA Astrophysics Data System (ADS)

    Adam, Mariana; Marenco, Franco

    2016-06-01

    The present research envisages the estimation of the overlap correction function for an airborne nadir-mounted lidar using multi-angle measurements. We have scanned a series of offnadir angles and after data processing we have been able to determine the instrument's overlap function down to 95m from the lidar. This function can be used for the correction of lidar profiles and hence reduce the near-range uncertainty of lidar measurements. To our knowledge, the estimation of the overlap function using multi-angle method for a nadir pointing lidar is a première.

  6. Detecting overlapping protein complexes by rough-fuzzy clustering in protein-protein interaction networks.

    PubMed

    Wu, Hao; Gao, Lin; Dong, Jihua; Yang, Xiaofei

    2014-01-01

    In this paper, we present a novel rough-fuzzy clustering (RFC) method to detect overlapping protein complexes in protein-protein interaction (PPI) networks. RFC focuses on fuzzy relation model rather than graph model by integrating fuzzy sets and rough sets, employs the upper and lower approximations of rough sets to deal with overlapping complexes, and calculates the number of complexes automatically. Fuzzy relation between proteins is established and then transformed into fuzzy equivalence relation. Non-overlapping complexes correspond to equivalence classes satisfying certain equivalence relation. To obtain overlapping complexes, we calculate the similarity between one protein and each complex, and then determine whether the protein belongs to one or multiple complexes by computing the ratio of each similarity to maximum similarity. To validate RFC quantitatively, we test it in Gavin, Collins, Krogan and BioGRID datasets. Experiment results show that there is a good correspondence to reference complexes in MIPS and SGD databases. Then we compare RFC with several previous methods, including ClusterONE, CMC, MCL, GCE, OSLOM and CFinder. Results show the precision, sensitivity and separation are 32.4%, 42.9% and 81.9% higher than mean of the five methods in four weighted networks, and are 0.5%, 11.2% and 66.1% higher than mean of the six methods in five unweighted networks. Our method RFC works well for protein complexes detection and provides a new insight of network division, and it can also be applied to identify overlapping community structure in social networks and LFR benchmark networks.

  7. Backmasking in the yeast genome: encoding overlapping information for protein-coding and RNA degradation

    PubMed Central

    Cakiroglu, S. Aylin; Zaugg, Judith B.; Luscombe, Nicholas M.

    2016-01-01

    Backmasking is a recording technique used to hide a sound or message in a music track in reverse, meaning that it is only audible when the record is played backwards. Analogously, the compact yeast genome encodes for diverse sources of information such as overlapping coding and non-coding transcripts, and protein-binding sites on the two complementary DNA strands. Examples are the consensus binding site sequences of the RNA-binding proteins Nrd1 and Nab3 that target non-coding transcripts for degradation. Here, by examining the overlap of stable (SUTs, stable unannotated transcripts) and unstable (CUTs, cryptic unstable transcripts) transcripts with protein-coding genes, we show that the predicted Nrd1 and Nab3-binding site sequences occur at differing frequencies. They are always depleted in the sense direction of protein-coding genes, thus avoiding degradation of the transcript. However in the antisense direction, predicted binding sites occur at high frequencies in genes with overlapping unstable ncRNAs (CUTs), so limiting the availability of non-functional transcripts. In contrast they are depleted in genes with overlapping stable ncRNAs (SUTs), presumably to avoid degrading the non-coding transcript. The protein-coding genes maintain similar amino-acid contents, but they display distinct codon usages so that Nrd1 and Nab3-binding sites can arise at differing frequencies in antisense depending on the overlapping transcript type. Our study demonstrates how yeast has evolved to encode multiple layers of information—protein-coding genes in one strand and the relative chance of degrading antisense RNA in the other strand—in the same regions of a compact genome. PMID:27492286

  8. Optical pulse synthesis using brillouin selective sideband amplification

    NASA Technical Reports Server (NTRS)

    Yao, X. Steve (Inventor)

    2002-01-01

    Techniques for producing optical pulses based on Brillouin selective sideband amplification by using a common modulation control signal to modulate both a signal beam to produce multiple sideband signals and a single pump beam to produce multiple pump beams.

  9. Propagation of an ultrashort, intense laser pulse in a relativistic plasma

    SciTech Connect

    Ritchie, B.; Decker, C.D.

    1997-12-31

    A Maxwell-relativistic fluid model is developed for the propagation of an ultrashort, intense laser pulse through an underdense plasma. The separability of plasma and optical frequencies ({omega}{sub p} and {omega} respectively) for small {omega}{sub p}/{omega} is not assumed; thus the validity of multiple-scales theory (MST) can be tested. The theory is valid when {omega}{sub p}/{omega} is of order unity or for cases in which {omega}{sub p}/{omega} {much_lt} 1 but strongly relativistic motion causes higher-order plasma harmonics to be generated which overlap the region of the first-order laser harmonic, such that MST would not expected to be valid although its principal validity criterion {omega}{sub p}/{omega} {much_lt} 1 holds.

  10. Unsupervised segmentation of overlapped nuclei using Bayesian classification.

    PubMed

    Jung, Chanho; Kim, Changick; Chae, Seoung Wan; Oh, Sukjoong

    2010-12-01

    In a fully automatic cell extraction process, one of the main issues to overcome is the problem related to extracting overlapped nuclei since such nuclei will often affect the quantitative analysis of cell images. In this paper, we present an unsupervised Bayesian classification scheme for separating overlapped nuclei. The proposed approach first involves applying the distance transform to overlapped nuclei. The topographic surface generated by distance transform is viewed as a mixture of Gaussians in the proposed algorithm. In order to learn the distribution of the topographic surface, the parametric expectation-maximization (EM) algorithm is employed. Cluster validation is performed to determine how many nuclei are overlapped. Our segmentation approach incorporates a priori knowledge about the regular shape of clumped nuclei to yield more accurate segmentation results. Experimental results show that the proposed method yields superior segmentation performance, compared to those produced by conventional schemes.

  11. 42 CFR 73.4 - Overlap select agents and toxins.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... genetically modified. (d) Overlap select agents or toxins that meet any of the following criteria are excluded... Equine Encephalitis virus (c) Genetic Elements, Recombinant Nucleic Acids, and Recombinant Organisms:...

  12. 42 CFR 73.4 - Overlap select agents and toxins.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... genetically modified. (d) Overlap select agents or toxins that meet any of the following criteria are excluded... Equine Encephalitis virus (c) Genetic Elements, Recombinant Nucleic Acids, and Recombinant Organisms:...

  13. 42 CFR 73.4 - Overlap select agents and toxins.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... have been genetically modified. (d) Overlap select agents or toxins that meet any of the following... Elements, Recombinant and/or Synthetic Nucleic Acids, and Recombinant and/or Synthetic Organisms:...

  14. 42 CFR 73.4 - Overlap select agents and toxins.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... genetically modified. (d) Overlap select agents or toxins that meet any of the following criteria are excluded... Equine Encephalitis virus (c) Genetic Elements, Recombinant Nucleic Acids, and Recombinant Organisms:...

  15. The ABN Database: Sampling Strategies for Collection Overlap Studies.

    ERIC Educational Resources Information Center

    Rochester, Maxine K.

    1987-01-01

    Reports the methodology and results of a study which explored the potential of three approaches to sampling the Australian Bibliographic Network (ABN) database files for determining collection overlap among Australian libraries. (Author/CLB)

  16. Resolution enhancement of holographic printer using a hogel overlapping method.

    PubMed

    Hong, Keehoon; Park, Soon-gi; Yeom, Jiwoon; Kim, Jonghyun; Chen, Ni; Pyun, Kyungsuk; Choi, Chilsung; Kim, Sunil; An, Jungkwuen; Lee, Hong-Seok; Chung, U-in; Lee, Byoungho

    2013-06-17

    We propose a hogel overlapping method for the holographic printer to enhance the lateral resolution of holographic stereograms. The hogel size is directly related to the lateral resolution of the holographic stereogram. Our analysis by computer simulation shows that there is a limit to decreasing the hogel size while printing holographic stereograms. Instead of reducing the size of hogel, the lateral resolution of holographic stereograms can be enhanced by printing overlapped hogels, which makes it possible to take advantage of multiplexing property of the volume hologram. We built a holographic printer, and recorded two holographic stereograms using the conventional and proposed overlapping methods. The images and movies of the holographic stereograms experimentally captured were compared between the conventional and proposed methods. The experimental results confirm that the proposed hogel overlapping method improves the lateral resolution of holographic stereograms compared to the conventional holographic printing method.

  17. Analysis of Surface Roughness at Overlapping Laser Shock Peening

    NASA Astrophysics Data System (ADS)

    Dai, F. Z.; Zhang, Z. D.; Zhou, J. Z.; Lu, J. Z.; Zhang, Y. K.

    2016-02-01

    The overlapping effects on surface roughness are studied when samples are treated by laser shock peening (LSP). Surface roughness of overlapped circular laser spot is calculated by ISO 25178 height parameters. The usually used overlapping styles namely isosceles-right-triangle-style (AAP) and equilateral-triangle-style (AAA) are carefully investigated when the overlapping degree in x-axis (ηx) is below 50%. Surface roughness of isosceles-right-triangle-style attains its minimum value at ηx of 29.3%, and attains its maximum value at ηx of 43.6%. Surface roughness of equilateral-triangle-style attains its minimum value at ηx of 42.3%, and attains its maximum value at ηx of 32%. Experimental results are well consistent with theoretical analysis.

  18. Overlapped conic simulation of three-body trajectories

    NASA Technical Reports Server (NTRS)

    Wilson, S. W., Jr.

    1970-01-01

    Trajectory computation technique for three-body motion is based on analytical derivation and empirical validation of pseudostate theory. Application of technique yields ''overlapped conic'' trajectories with error magnitudes only 20 percent as great as those of patched conic trajectories.

  19. A Reexamination of the Small Overlap Frontal Crash

    PubMed Central

    Scullion, Paul; Morgan, Richard M.; Mohan, Pradeep; Kan, Cing-Dao; Shanks, Kurt; Jin, Wook; Tangirala, Ravi

    2010-01-01

    The objective of this study was to examine and rank the Small Overlap Frontal Crash as one of the eight-group taxonomy proposed by Ford. The Ford taxonomy classifies real-world frontal-impact crashes based on the National Automotive Sampling System (NASS). Frontally-impacted vehicles were identified for 1985 – 2008 model year passenger vehicles with Collision Deformation Classification (CDC) data from the 1995 – 2008 years of NASS. Small overlap frontal cases were identified where there was no engagement of the vehicle frame rails, and the direct damage was located entirely outside of the vehicle frame rails. The results are that full engagement and offset (offset category means the direct damage overlaps the vehicle frame rail, with the center of direct damage between the frame rails) were the most frequent crashes contributing 35% each. The frequency of the small overlap frontal was 6%. The risks of injury (AIS ≥ 2) for the full engagement, offset, and small overlap were 8%, 6%, and 3% respectively. For this study, the number of small overlap vehicles was 1,118 and the number of injured nearside occupants was 100. This study—following the Ford approach and reasonably identifying the location of the longitudinal rails based on CDC—suggests that the small overlap is at worst a moderately dangerous crash in the overall scheme of frontal crashes. The implications of this study are that the safety community should reexamine the significance of the small overlap frontal crash against an overall taxonomy of crashes. PMID:21050598

  20. Characterizing Computation-Communication Overlap in Message-Passing Systems

    SciTech Connect

    David E. Bernholdt; Jarek Nieplocha; P. Sadayappan; Aniruddha G. Shet; Vinod Tipparaju

    2008-01-31

    Effective overlap of computation and communication is a well understood technique for latency hiding and can yield significant performance gains for applications on high-end computers. In this report, we describe an instrumentation framework developed for messagepassing systems to characterize the degree of overlap of communication with computation in the execution of parallel applications. The inability to obtain precise time-stamps for pertinent communication events is a significant problem, and is addressed by generation of minimum and maximum bounds on achieved overlap. The overlap measures can aid application developers and system designers in investigating scalability issues. The approach has been used to instrument two MPI implementations as well as the ARMCI system. The implementation resides entirely within the communication library and thus integrates well with existing approaches that operate outside the library. The utility of the framework is demonstrated by analyzing communication-computation overlap for micro-benchmarks and the NAS benchmarks, and the insights obtained are used to modify the NAS SP benchmark, resulting in improved overlap.

  1. Characterizing Computation-Communication Overlap in Message-Passing Systems

    SciTech Connect

    David E. Bernholdt; Jarek Nieplocha; P. Sadayappan; Aniruddha G. Shet; Vinod Tipparaju

    2008-01-31

    Effective overlap of computation and communication is a well understood technique for latency hiding and can yield significant performance gains for applications on high-end computers. In this report, we describe an instrumentation framework developed for message-passing systems to characterize the degree of overlap of communication with computation in the execution of parallel applications. The inability to obtain precise time-stamps for pertinent communication events is a significant problem, and is addressed by generation of minimum and maximum bounds on achieved overlap. The overlap measures can aid application developers and system designers in investigating scalability issues. The approach has been used to instrument two MPI implementations as well as the ARMCI system. The implementation resides entirely within the communication library and thus integrates well with existing approaches that operate outside the library. The utility of the framework is demonstrated by analyzing communication-computation overlap for micro-benchmarks and the NAS benchmarks, and the insights obtained are used to modify the NAS SP benchmark, resulting in improved overlap.

  2. A Bayesian variable selection procedure to rank overlapping gene sets

    PubMed Central

    2012-01-01

    Background Genome-wide expression profiling using microarrays or sequence-based technologies allows us to identify genes and genetic pathways whose expression patterns influence complex traits. Different methods to prioritize gene sets, such as the genes in a given molecular pathway, have been described. In many cases, these methods test one gene set at a time, and therefore do not consider overlaps among the pathways. Here, we present a Bayesian variable selection method to prioritize gene sets that overcomes this limitation by considering all gene sets simultaneously. We applied Bayesian variable selection to differential expression to prioritize the molecular and genetic pathways involved in the responses to Escherichia coli infection in Danish Holstein cows. Results We used a Bayesian variable selection method to prioritize Kyoto Encyclopedia of Genes and Genomes pathways. We used our data to study how the variable selection method was affected by overlaps among the pathways. In addition, we compared our approach to another that ignores the overlaps, and studied the differences in the prioritization. The variable selection method was robust to a change in prior probability and stable given a limited number of observations. Conclusions Bayesian variable selection is a useful way to prioritize gene sets while considering their overlaps. Ignoring the overlaps gives different and possibly misleading results. Additional procedures may be needed in cases of highly overlapping pathways that are hard to prioritize. PMID:22554182

  3. Adiabatic continuity, wave-function overlap, and topological phase transitions

    NASA Astrophysics Data System (ADS)

    Gu, Jiahua; Sun, Kai

    2016-09-01

    In this paper, we study the relation between wave-function overlap and adiabatic continuity in gapped quantum systems. We show that for two band insulators, a scalar function can be defined in the momentum space, which characterizes the wave-function overlap between Bloch states in the two insulators. If this overlap is nonzero for all momentum points in the Brillouin zone, these two insulators are adiabatically connected, i.e., we can deform one insulator into the other smoothly without closing the band gap. In addition, we further prove that this adiabatic path preserves all the symmetries of the insulators. The existence of such an adiabatic path implies that two insulators with nonzero wave-function overlap belong to the same topological phase. This relation, between adiabatic continuity and wave-function overlap, can be further generalized to correlated systems. The generalized relation cannot be applied to study generic many-body systems in the thermodynamic limit, because of the orthogonality catastrophe. However, for certain interacting systems (e.g., quantum Hall systems), the quantum wave-function overlap can be utilized to distinguish different quantum states. Experimental implications are also discussed.

  4. Conveniently assembled multiple-electrode-pair CO2 laser

    NASA Astrophysics Data System (ADS)

    Ye, Lihua; Li, Xiangyen; He, Anzhi

    2000-04-01

    A conveniently assembled multiple-electrode-pair (MEP) transversely excited amplify (TEA) CO2 laser is introduced in this paper. The laser is described from the view of device configuration, power supply, control circuit, and etc. The laser output is variable from single pulse to double pulse and multiple pulse with different assembly. We adopt a new alignment method for cavity. The pulse time interval given by control system is continuously adjustable from 0 to 150 microseconds. Experiments prove that the pulse series property is stable and that the pulse parameters are perfect. The conveniently assembled laser lay a foundation for the industry application of multiple-electrode-pair CO2 laser.

  5. ADRF experiments using near n.pi pulse strings. [Adiabatic Demagnetization due to Radio Frequency pulses

    NASA Technical Reports Server (NTRS)

    Rhim, W. K.; Burum, D. P.; Elleman, D. D.

    1977-01-01

    Adiabatic demagnetization (ADRF) can be achieved in a dipolar coupled nuclear spin system in solids by applying a string of short RF pulses and gradually modulating the pulse amplitudes or pulse angles. This letter reports an adiabatic inverse polarization effect in solids and a rotary spin echo phenomenon observed in liquids when the pulse angle is gradually changed across integral multiples of pi during a string of RF pulses. The RF pulse sequence used is illustrated along with the NMR signal from a CaF2 single crystal as observed between the RF pulses and the rotary spin echo signal observed in liquid C6F6 for n = 2. The observed effects are explained qualitatively on the basis of average Hamiltonian theory.

  6. GPU simulation of nonlinear propagation of dual band ultrasound pulse complexes

    SciTech Connect

    Kvam, Johannes Angelsen, Bjørn A. J.; Elster, Anne C.

    2015-10-28

    In a new method of ultrasound imaging, called SURF imaging, dual band pulse complexes composed of overlapping low frequency (LF) and high frequency (HF) pulses are transmitted, where the frequency ratio LF:HF ∼ 1 : 20, and the relative bandwidth of both pulses are ∼ 50 − 70%. The LF pulse length is hence ∼ 20 times the HF pulse length. The LF pulse is used to nonlinearly manipulate the material elasticity observed by the co-propagating HF pulse. This produces nonlinear interaction effects that give more information on the propagation of the pulse complex. Due to the large difference in frequency and pulse length between the LF and the HF pulses, we have developed a dual level simulation where the LF pulse propagation is first simulated independent of the HF pulse, using a temporal sampling frequency matched to the LF pulse. A separate equation for the HF pulse is developed, where the the presimulated LF pulse modifies the propagation velocity. The equations are adapted to parallel processing in a GPU, where nonlinear simulations of a typical HF beam of 10 MHz down to 40 mm is done in ∼ 2 secs in a standard GPU. This simulation is hence very useful for studying the manipulation effect of the LF pulse on the HF pulse.

  7. Photon statistics of atomic fluorescence after {pi}-pulse excitation

    SciTech Connect

    Yoshimi, Kazuyoshi; Koshino, Kazuki

    2010-09-15

    The photon statistics of atomic fluorescence after {pi}-pulse excitation is investigated in a system in which the input and output ports are connected to an atom. Since spontaneous decay during input pulse excitation occurs, the output pulse generally contains a multiphoton component with a certain probability. We quantitatively evaluate the probability of the output pulse containing multiple photons and determine the conditions for ideal single-photon generation.

  8. ADJUSTABLE DOUBLE PULSE GENERATOR

    DOEpatents

    Gratian, J.W.; Gratian, A.C.

    1961-08-01

    >A modulator pulse source having adjustable pulse width and adjustable pulse spacing is described. The generator consists of a cross coupled multivibrator having adjustable time constant circuitry in each leg, an adjustable differentiating circuit in the output of each leg, a mixing and rectifying circuit for combining the differentiated pulses and generating in its output a resultant sequence of negative pulses, and a final amplifying circuit for inverting and square-topping the pulses. (AEC)

  9. Pulsed discharge production Ar* metastables

    NASA Astrophysics Data System (ADS)

    Han, Jiande; Heaven, Michael C.; Emmons, Daniel; Perram, Glen P.; Weeks, David E.; Bailey, William F.

    2016-03-01

    The production of relatively high densities of Ar* metastables (>1012 cm-3) in Ar/He mixtures, at total pressures close to 1 atm, is essential for the efficient operation of an optically pumped Ar* laser. We have used emission spectroscopy and diode laser absorption spectroscopy measurements to observe the production and decay of Ar* in a parallel plate pulsed discharge. With discharge pulses of 1 μs duration we find that metastable production is dominated by processes occurring within the first 100 ns of the gas break-down. Application of multiple, closely spaced discharge pulses yields insights concerning conditions that favor metastable production. This information has been combined with time-resolved measurements of voltage and current. The experimental results and preliminary modeling of the discharge kinetics are presented.

  10. Presentation of dynamically overlapping auditory messages in user interfaces

    SciTech Connect

    Papp, A.L.

    1997-09-01

    This dissertation describes a methodology and example implementation for the dynamic regulation of temporally overlapping auditory messages in computer-user interfaces. The regulation mechanism exists to schedule numerous overlapping auditory messages in such a way that each individual message remains perceptually distinct from all others. The method is based on the research conducted in the area of auditory scene analysis. While numerous applications have been engineered to present the user with temporally overlapped auditory output, they have generally been designed without any structured method of controlling the perceptual aspects of the sound. The method of scheduling temporally overlapping sounds has been extended to function in an environment where numerous applications can present sound independently of each other. The Centralized Audio Presentation System is a global regulation mechanism that controls all audio output requests made from all currently running applications. The notion of multimodal objects is explored in this system as well. Each audio request that represents a particular message can include numerous auditory representations, such as musical motives and voice. The Presentation System scheduling algorithm selects the best representation according to the current global auditory system state, and presents it to the user within the request constraints of priority and maximum acceptable latency. The perceptual conflicts between temporally overlapping audio messages are examined in depth through the Computational Auditory Scene Synthesizer. At the heart of this system is a heuristic-based auditory scene synthesis scheduling method. Different schedules of overlapped sounds are evaluated and assigned penalty scores. High scores represent presentations that include perceptual conflicts between over-lapping sounds. Low scores indicate fewer and less serious conflicts. A user study was conducted to validate that the perceptual difficulties predicted by

  11. Spatiotemporal control of degenerate multiphoton fluorescence microscopy with delay-tunable femtosecond pulse pairs

    NASA Astrophysics Data System (ADS)

    Das, Dhiman; Bhattacharyya, Indrajit; Goswami, Debabrata

    2016-07-01

    Selective excitation of a particular fluorophore in an ensemble of different fluorophores with overlapping fluorescence spectra is shown to be dependent on the time delay of femtosecond pulse pairs in multiphoton fluorescence microscopy. In particular, the two-photon fluorescence behavior of the Texas Red and DAPI dye pair inside Bovine Pulmonary Artery Endothelial (BPAE) cells depends strongly on the center wavelength of the laser, as well as the delay between two identical laser pulses in one-color femtosecond pulse-pair excitation scheme. Thus, we present a novel design concept using pairs of femtosecond pulses at different central wavelengths and tunable pulse separations for controlling the image contrast between two spatially and spectrally overlapping fluorophores. This femtosecond pulse-pair technique is unique in utilizing the variation of dye dynamics inside biological cells as a contrast mode in microscopy of different fluorophores.

  12. [Analysis of three-dimensional fluorescence overlapping spectra using nonnegative matrix factorization].

    PubMed

    Yu, Xiao-Ya; Zhang, Yu-Jun; Yin, Gao-Fang; Zhao, Nan-Jing; Xiao, Xue; Zhang, Wei; Zhang, Rong; Lu, Chang-Hua; Liu, Wen-Qing

    2014-03-01

    The present paper primarily tests and verifies the effect of NMF in blind source separation of three-dimensional simulative fluorescence spectra, and then four different computational algorithms (multiplicative iterative; alternating least square; second order method; projected gradient algorithm) were used in three practical phenolic compounds (cresol, phenol, thymol) overlapping fluorescence spectra to find out which nonnegatively constrained algorithms is the most efficient for fluorescence spectra unmixing. The experiments demonstrate that four ways have the normalized residuals below 0.06%, and alternating least square (ALS) is the best at both convergence behavior and robustness. PMID:25208393

  13. Stochastic ion heating from many overlapping laser beams in fusion plasmas.

    PubMed

    Michel, P; Rozmus, W; Williams, E A; Divol, L; Berger, R L; Town, R P J; Glenzer, S H; Callahan, D A

    2012-11-01

    In this Letter, we show through numerical simulations and analytical results that overlapping multiple (N) laser beams in plasmas can lead to strong stochastic ion heating from many (~N(2)) electrostatic perturbations driven by beat waves between pairs of laser beams. For conditions typical of inertial-confinement-fusion experiment conditions, hundreds of such beat waves are driven in mm(3)-scale plasmas, leading to ion heating rates of several keV/ns. This mechanism saturates cross-beam energy transfer, with a reduction of linear gains by a factor ~4-5 and can strongly modify the overall hydrodynamics evolution of such laser-plasma systems. PMID:23215392

  14. [New actors in the fight against HIV/AIDS: overlapping and competition between existing structures].

    PubMed

    Tantchou Yakam, J C

    2008-06-01

    The HIV/AIDS pandemia reshaped international relations and the world research landscape. New facilities have been created and new actors have emerged. New institutions has been grafted into the existing health infrastructure resulting in overlapping and sometimes conflicting actions. In this study we analyze this co-existence using the "Centre of Prevention and Voluntary testing of HIV/AIDS" (CPDV) in Cameroon as an example. The purpose is to show that the involvment of new actors in a health systems with multiple dysfunctions creates an environment leading to "straddling". This situation also raises legitimacy issues and leads to competition for position within the existing hierarchies. PMID:18689327

  15. Mapping overlapping functional elements embedded within the protein-coding regions of RNA viruses

    PubMed Central

    Firth, Andrew E.

    2014-01-01

    Identification of the full complement of genes and other functional elements in any virus is crucial to fully understand its molecular biology and guide the development of effective control strategies. RNA viruses have compact multifunctional genomes that frequently contain overlapping genes and non-coding functional elements embedded within protein-coding sequences. Overlapping features often escape detection because it can be difficult to disentangle the multiple roles of the constituent nucleotides via mutational analyses, while high-throughput experimental techniques are often unable to distinguish functional elements from incidental features. However, RNA viruses evolve very rapidly so that, even within a single species, substitutions rapidly accumulate at neutral or near-neutral sites providing great potential for comparative genomics to distinguish the signature of purifying selection. Computationally identified features can then be efficiently targeted for experimental analysis. Here we analyze alignments of protein-coding virus sequences to identify regions where there is a statistically significant reduction in the degree of variability at synonymous sites, a characteristic signature of overlapping functional elements. Having previously tested this technique by experimental verification of discoveries in selected viruses, we now analyze sequence alignments for ∼700 RNA virus species to identify hundreds of such regions, many of which have not been previously described. PMID:25326325

  16. Increasing efficiency in intermediate band solar cells with overlapping absorptions

    NASA Astrophysics Data System (ADS)

    Krishna, Akshay; Krich, Jacob J.

    2016-07-01

    Intermediate band (IB) materials are promising candidates for realizing high efficiency solar cells. In IB photovoltaics, photons are absorbed in one of three possible electronic transitions—valence to conduction band, valence to intermediate band, or intermediate to conduction band. With fully concentrated sunlight, when the band gaps have been chosen appropriately, the highest efficiency IB solar cells require that these three absorptions be non-overlapping, so absorbed photons of fixed energy contribute to only one transition. The realistic case of overlapping absorptions, where the transitions compete for photons, is generally considered to be a source of loss. We show that overlapping absorptions can in fact lead to significant improvements in IB solar cell efficiencies, especially for IB that are near the middle of the band gap. At low to moderate concentration, the highest efficiency requires overlapping absorptions. We use the detailed-balance method and indicate how much overlap of the absorptions is required to achieve efficiency improvements, comparing with some known cases. These results substantially broaden the set of materials that can be suitable for high-efficiency IB solar cells.

  17. Controlling the spectrum of light pulses by dynamical electromagnetically induced transparency

    SciTech Connect

    Ignesti, Emilio; Sali, Emiliano; Tognetti, Marco V.; Buffa, Roberto; Fini, Lorenzo; Cavalieri, Stefano

    2011-05-15

    We present a theoretical and experimental study on the possibility of spectral manipulation of weak probe-laser pulses in the presence of dynamical electromagnetically induced transparency. We predict a spectral enlargement or narrowing process depending on whether the probe-laser pulse is overlapped by the rising or the falling edge of the coupling pulse, respectively. The results of an experiment in sodium atomic vapors confirm the theoretical predictions.

  18. Method and apparatus for measuring the intensity and phase of an ultrashort light pulse

    DOEpatents

    Kane, Daniel J.; Trebino, Rick P.

    1998-01-01

    The pulse shape I(t) and phase evolution x(t) of ultrashort light pulses are obtained using an instantaneously responding nonlinear optical medium to form a signal pulse. A light pulse, such a laser pulse, is split into a gate pulse and a probe pulse, where the gate pulse is delayed relative to the probe pulse. The gate pulse and the probe pulse are combined within an instantaneously responding optical medium to form a signal pulse functionally related to a temporal slice of the gate pulse corresponding to the time delay of the probe pulse. The signal pulse is then input to a wavelength-selective device to output pulse field information comprising intensity vs. frequency for a first value of the time delay. The time delay is varied over a range of values effective to yield an intensity plot of signal intensity vs. wavelength and delay. In one embodiment, the beams are overlapped at an angle so that a selected range of delay times is within the intersection to produce a simultaneous output over the time delays of interest.

  19. Crosstalk analysis of pathways in breast cancer using a network model based on overlapping differentially expressed genes

    PubMed Central

    SUN, YONG; YUAN, KAI; ZHANG, PENG; MA, RONG; ZHANG, QI-WEN; TIAN, XING-SONG

    2015-01-01

    Multiple signal transduction pathways can affect each other considerably through crosstalk. However, the presence and extent of this phenomenon have not been rigorously studied. The aim of the present study was to identify strong and normal interactions between pathways in breast cancer and determine the main pathway. Five sets of breast cancer data were downloaded from the high-throughput Gene Expression Omnibus (GEO) and analyzed to identify differentially expressed (DE) genes using the Rank Product (RankProd) method. A list of pathways with differential expression was obtained by gene set enrichment analysis (GSEA) of the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. The DE genes that overlapped between pathways were identified and a crosstalk network diagram based on the overlap of DE genes was constructed. A total of 1,464 DE genes and 26 pathways were identified. In addition, the number of DE genes that overlapped between specific pathways were determined, and the greatest degree of overlap was between the extracellular matrix (ECM)-receptor interaction and Focal adhesion pathways, which had 22 overlapping DE genes. Weighted pathway analysis of the crosstalk between pathways identified that Pathways in cancer was the main pathway in breast cancer. PMID:26622386

  20. Deterministic processing of alumina with ultra-short laser pulses

    SciTech Connect

    Furmanski, J; Rubenchik, A M; Shirk, M D; Stuart, B C

    2007-06-27

    Ultrashort pulsed lasers can accurately ablate materials which are refractory, transparent, or are otherwise difficult to machine by other methods. The typical method of machining surfaces with ultrashort laser pulses is by raster scanning, or the machining of sequentially overlapping linear trenches. Experiments in which linear trenches were machined in alumina at various pulse overlaps and incident fluences are presented, and the dependence of groove depth on these parameters established. A model for the machining of trenches based on experimental data in alumina is presented, which predicts and matches observed trench geometry. This model is then used to predict optimal process parameters for the machining of trenches for maximal material removal rate for a given laser.

  1. Effect of overlap and overscan number in laser surface texturing of medical needles

    NASA Astrophysics Data System (ADS)

    Wang, Xingsheng; Xing, Youqiang; Giovannini, Marco

    2015-07-01

    Micro-features are frequently created on medical needles to improve the visibility and friction behavior in ultrasound-guided percutaneous procedures. Ultra-short pulsed laser ablation is the front runner among the current material micro-processing technologies. In this paper, the effect of process parameters in laser surface texturing (LST) of medical needles was studied by experiments based on Taguchi methodology. The evolution of ablation dimension and surface roughness with different process parameters was measured by optical microscope. Based on response surface regression, mathematical models for correlating the machined depth and surface roughness with the overlap and overscan number were developed. Analysis of variance (ANOVA) was carried out to access the adequacy of the developed mathematical models. The results indicate that the developed mathematical models can predict the machined depth and surface roughness during LST operation satisfactorily. Analyses were made to study the effect of the process parameters on the machined micro-channel. From the analysis, it was found that the overlap and overscan number have great influences on the machined depth and surface roughness.

  2. Long pulse production from short pulses

    DOEpatents

    Toeppen, John S.

    1994-01-01

    A method of producing a long output pulse (SA) from a short pump pulse (P), using an elongated amplified fiber (11) having a doped core (12) that provides an amplifying medium for light of one color when driven into an excited state by light of a shorter wavelength and a surrounding cladding 13. A seed beam (S) of the longer wavelength is injected into the core (12) at one end of the fiber (11) and a pump pulse (P) of the shorter wavelength is injected into the cladding (13) at the other end of the fiber (11). The counter-propagating seed beam (S) and pump pulse (P) will produce an amplified output pulse (SA) having a time duration equal to twice the transit time of the pump pulse (P) through the fiber (11) plus the length of the pump pulse (P).

  3. Long pulse production from short pulses

    DOEpatents

    Toeppen, J.S.

    1994-08-02

    A method of producing a long output pulse from a short pump pulse is disclosed, using an elongated amplified fiber having a doped core that provides an amplifying medium for light of one color when driven into an excited state by light of a shorter wavelength and a surrounding cladding. A seed beam of the longer wavelength is injected into the core at one end of the fiber and a pump pulse of the shorter wavelength is injected into the cladding at the other end of the fiber. The counter-propagating seed beam and pump pulse will produce an amplified output pulse having a time duration equal to twice the transit time of the pump pulse through the fiber plus the length of the pump pulse. 3 figs.

  4. Climate-induced range overlap among closely related species

    NASA Astrophysics Data System (ADS)

    Krosby, Meade; Wilsey, Chad B.; McGuire, Jenny L.; Duggan, Jennifer M.; Nogeire, Theresa M.; Heinrichs, Julie A.; Tewksbury, Joshua J.; Lawler, Joshua J.

    2015-09-01

    Contemporary climate change is causing large shifts in biotic distributions, which has the potential to bring previously isolated, closely related species into contact. This has led to concern that hybridization and competition could threaten species persistence. Here, we use bioclimatic models to show that future range overlap by the end of the century is predicted for only 6.4% of isolated, congeneric species pairs of New World birds, mammals and amphibians. Projected rates of climate-induced overlap are higher for birds (11.6%) than for mammals (4.4%) or amphibians (3.6%). As many species will have difficulty tracking shifting climates, actual rates of future overlap are likely to be far lower, suggesting that hybridization and competition impacts may be relatively modest.

  5. Bipolar nanosecond electric pulses are less efficient at electropermeabilization and killing cells than monopolar pulses

    PubMed Central

    Ibey, Bennett L.; Ullery, Jody; Pakhomova, Olga N.; Roth, Caleb C.; Semenov, Iurri; Beier, Hope T.; Tarango, Melissa; Xiao, Shu; Schoenbach, Karl; Pakhomov, Andrei G.

    2014-01-01

    Multiple studies have shown that bipolar (BP) electric pulses in the microsecond range are more effective at permeabilizing cells while maintaining similar cell survival rates as compared to monopolar (MP) pulse equivalents. In this paper, we investigated whether the same advantage existed for BP nanosecond-pulsed electric fields (nsPEF) as compared to MP nsPEF. To study permeabilization effectiveness, MP or BP pulses were delivered to single Chinese hamster ovary (CHO) cells and the response of three dyes, Calcium Green-1, Propidium Iodide (PI), and FM1-43, was measured by confocal microscopy. Results show that BP pulses were less effective at increasing intracellular calcium concentration or PI uptake and cause less membrane reorganization (FM1-43) than MP pulses. Twenty-four hour survival was measured in three cell lines (Jurkat, U937, CHO) and over ten times more BP pulses were required to induce death as compared to MP pulses of similar magnitude and duration. Flow cytometry analysis of CHO cells after exposure (15 minutes) revealed that to achieve positive FITC-Annexin V and PI expression, ten times more BP pulses were required than MP pulses. Overall, unlike longer pulse exposures, BP nsPEF exposures proved far less effective at both membrane permeabilization and cell killing than MP nsPEF. PMID:24332942

  6. Bipolar nanosecond electric pulses are less efficient at electropermeabilization and killing cells than monopolar pulses.

    PubMed

    Ibey, Bennett L; Ullery, Jody C; Pakhomova, Olga N; Roth, Caleb C; Semenov, Iurii; Beier, Hope T; Tarango, Melissa; Xiao, Shu; Schoenbach, Karl H; Pakhomov, Andrei G

    2014-01-10

    Multiple studies have shown that bipolar (BP) electric pulses in the microsecond range are more effective at permeabilizing cells while maintaining similar cell survival rates as compared to monopolar (MP) pulse equivalents. In this paper, we investigated whether the same advantage existed for BP nanosecond-pulsed electric fields (nsPEF) as compared to MP nsPEF. To study permeabilization effectiveness, MP or BP pulses were delivered to single Chinese hamster ovary (CHO) cells and the response of three dyes, Calcium Green-1, propidium iodide (PI), and FM1-43, was measured by confocal microscopy. Results show that BP pulses were less effective at increasing intracellular calcium concentration or PI uptake and cause less membrane reorganization (FM1-43) than MP pulses. Twenty-four hour survival was measured in three cell lines (Jurkat, U937, CHO) and over ten times more BP pulses were required to induce death as compared to MP pulses of similar magnitude and duration. Flow cytometry analysis of CHO cells after exposure (at 15 min) revealed that to achieve positive FITC-Annexin V and PI expression, ten times more BP pulses were required than MP pulses. Overall, unlike longer pulse exposures, BP nsPEF exposures proved far less effective at both membrane permeabilization and cell killing than MP nsPEF.

  7. Maximal charge injection of consecutive electron pulses with uniform temporal pulse separation

    SciTech Connect

    Liu, Y. L.; Zhang, P.; Chen, S. H.; Ang, L. K.

    2015-08-15

    A charge sheet model is proposed for the study of the space-charge limited density of consecutive electron pulses injected to in a diode with uniform temporal pulse separation. Based on the model, an analytical formula is derived for expressing the dependency of the charge density limit on the gap spacing, gap voltage, and pulse separation. The theoretical results are verified by numerical solutions up to electron energy of a few MeV, including relativistic effects. The model can be applied to the design of multiple-pulse electron beams for time resolved electron microscopy and free electron lasers.

  8. Overlaps among phenological phases in flood plain forest ecosystem

    NASA Astrophysics Data System (ADS)

    Bartošová, Lenka; Bauer, Zdeněk; Trnka, Miroslav; Možný, Martin; Štěpánek, Petr; Žalud, Zdeněk

    2015-04-01

    There is a growing concern that climate change has significant impacts on species phenology, seasonal population dynamics, and thus interaction (a)synchrony between species. Species that have historically undergone life history events on the same seasonal calendar may lose synchrony and therefore lose the ability to interact as they have in the past. In view of the match/mismatch hypothesis, the different extents or directions of the phenological shifts among interacting species may have significant implications for community structure and dynamics. That's why our principal goal of the study is to determine the phenological responses within the ecosystem of flood plain forest and analyzed the phenological overlapping among each phenological periods of given species. The phenological observations were done at flood-plain forest experimental site during the period 1961-2012. The whole ecosystem in this study create 17 species (15 plants and 2 bird species) and each species is composed of 2 phenological phases. Phenological periods of all species of ecosystem overlap each other and 43 of these overlapping were chosen and the length, trend and correlation with temperature were elaborated. The analysis of phenophases overlapping of chosen species showed that the length of overlay is getting significantly shorter in 1 case. On the other hand the situation when the length of overlaps is getting significantly longer arose in 4 cases. Remaining overlaps (38) of all phenological periods among various species is getting shorter or longer but with no significance or have not changed anyhow. This study was funded by project "Building up a multidisciplinary scientific team focused on drought" No. CZ.1.07/2.3.00/20.0248. and of projects no. LD13030 supporting participation of the Czech Republic in the COST action ES1106.

  9. Inference by eye: reading the overlap of independent confidence intervals.

    PubMed

    Cumming, Geoff

    2009-01-30

    When 95 per cent confidence intervals (CIs) on independent means do not overlap, the two-tailed p-value is less than 0.05 and there is a statistically significant difference between the means. However, p for non-overlapping 95 per cent CIs is actually considerably smaller than 0.05: If the two CIs just touch, p is about 0.01, and the intervals can overlap by as much as about half the length of one CI arm before p becomes as large as 0.05. Keeping in mind this rule-that overlap of half the length of one arm corresponds approximately to statistical significance at p = 0.05-can be helpful for a quick appreciation of figures that display CIs, especially if precise p-values are not reported. The author investigated the robustness of this and similar rules, and found them sufficiently accurate when sample sizes are at least 10, and the two intervals do not differ in width by more than a factor of 2. The author reviewed previous discussions of CI overlap and extended the investigation to p-values other than 0.05 and 0.01. He also studied 95 per cent CIs on two proportions, and on two Pearson correlations, and found similar rules apply to overlap of these asymmetric CIs, for a very broad range of cases. Wider use of figures with 95 per cent CIs is desirable, and these rules may assist easy and appropriate understanding of such figures.

  10. Charmonium Spectrum from Quenched QCD with Overlap Fermions

    SciTech Connect

    S. Tamhankar; A. Alexandru; Y. Chen; S.J. Dong; T. Draper; I. Horvath; F.X. Lee; K.F. Liu; N. Mathur; J.B. Zhang

    2005-07-20

    We present the first study of the charmonium spectrum using overlap fermions, on quenched configurations. Simulations are performed on 16{sup 3} x 72 lattices, with Wilson gauge action at {beta} = 6.3345. We demonstrate that we have discretization errors under control at about 5%. We obtain 88(4) MeV for hyperfine splitting using the {sub 0} scale, and 121(6) MeV using the (1{bar P}-1{bar S}) scale. This paper raises the possibility that the discrepancy between the lattice results and the experimental value for charmonium hyperfine splitting can be resolved using overlap fermions to simulate the charm quark on lattice.

  11. Encounter times in overlapping domains and aplication to epidemic spread

    NASA Astrophysics Data System (ADS)

    Solís, Paulina; Sanders, David P.

    2014-03-01

    We present results on encounter times for random walkers modeling territorial animals. The walkers are confined to habitats in one or two dimensions with reflecting boundaries, and neighboring habitats overlap. Using Monte Carlo simulations and numerically-exact calculations, we calculate encounter times as a function of the size of the habitats, and the size of the overlap region. These results are applied to model the spread of epidemics in populations of such animals; the speed of propagation of the epidemic is determined in terms of the role of the spatial organization.

  12. Overlapping illusions by transformation optics without any negative refraction material.

    PubMed

    Sun, Fei; He, Sailing

    2016-01-11

    A novel method to achieve an overlapping illusion without any negative refraction index material is introduced with the help of the optic-null medium (ONM) designed by an extremely stretching spatial transformation. Unlike the previous methods to achieve such an optical illusion by transformation optics (TO), our method can achieve a power combination and reshape the radiation pattern at the same time. Unlike the overlapping illusion with some negative refraction index material, our method is not sensitive to the loss of the materials. Other advantages over existing methods are discussed. Numerical simulations are given to verify the performance of the proposed devices.

  13. A parametric solution for optimal overlapped block motion compensation.

    PubMed

    Tao, B; Orchard, M T

    2001-01-01

    We find the optimal window for overlapped block motion compensation (OBMC) by statistically modeling the motion field, the field of block motion estimates and their relationship. This enables us to show how the optimal OBMC window is affected by random field parameters, such as the variance of the motion field and the correlation coefficients of both the intensity field and the motion field. The OBMC window obtained in this fashion is shown to have good performance in reducing the prediction error. Furthermore, this parametric solution provides insight into motion uncertainty and the overlapped motion compensation process. PMID:18249625

  14. Overlapping illusions by transformation optics without any negative refraction material

    PubMed Central

    Sun, Fei; He, Sailing

    2016-01-01

    A novel method to achieve an overlapping illusion without any negative refraction index material is introduced with the help of the optic-null medium (ONM) designed by an extremely stretching spatial transformation. Unlike the previous methods to achieve such an optical illusion by transformation optics (TO), our method can achieve a power combination and reshape the radiation pattern at the same time. Unlike the overlapping illusion with some negative refraction index material, our method is not sensitive to the loss of the materials. Other advantages over existing methods are discussed. Numerical simulations are given to verify the performance of the proposed devices. PMID:26751285

  15. Spinal cord stimulation with interleaved pulses: a randomized, controlled trial.

    PubMed

    North, Richard B; Kidd, David H; Olin, John; Sieracki, Jeffrey M; Boulay, Marc

    2007-10-01

    Objectives.  The development of multicontact electrodes and programmable, implanted pulse generators has increased the therapeutic success of spinal cord stimulation (SCS) by enhancing the ability to capture and maintain pain/paresthesia overlap. This study sought to determine if interleaved stimulation and/or frequency doubling improves pain/paresthesia overlap in patients with failed back surgery syndrome. Methods.  Using a patient-interactive computer system that quantifies SCS performance and presents stimulation settings in randomized, double-blind fashion, we compared the effect on pain/paresthesia overlap of interleaved stimulation (rapidly interleaved pulse trains using two different contact combinations) vs. standard treatment with a single contact combination, controlling for frequency doubling. Stimulation amplitude (charge per phase, as determined by varying pulse voltage or width) was adjusted to a subjectively comfortable intensity (usage amplitude), which was maintained for all trials in each patient. The number of percutaneous spinal electrodes used (one or two) and the phase angle between interleaved pulses were additional study variables. Results.  Multivariate analysis of 266 test results from 15 patients revealed a statistically significant (p ≤ 0.05) association between increased computer-calculated pain/paresthesia overlap and 1) high- and low-frequency interleaved stimulation using two combinations of contacts and 2) frequency doubling using one combination. We found no significant effect for electrode configuration (single or dual), pulse width matching, or phase angle. Conclusions.  The statistically significant advantages we observed for SCS with interleaved stimulation are explained, at least in part, by the effects of frequency doubling. These findings have important implications for the design and adjustment of pulse generators. PMID:22150894

  16. Pulses, linkages, and boundaries of coupled aquatic-terrestrial ecosystems

    NASA Astrophysics Data System (ADS)

    Tockner, K.

    2009-04-01

    Riverine floodplains are linked ecosystems where terrestrial and aquatic habitats overlap, creating a zone where they interact, the aquatic-terrestrial interface. The interface or boundary between aquatic and terrestrial habitats is an area of transition, contact or separation; and connectivity between these habitats may be defined as the ease with which organisms, matter or energy traverse these boundaries. Coupling of aquatic and terrestrial systems generates intertwining food webs, and we may predict that coupled systems are more productive than separated ones. For example, riparian consumers (aquatic and terrestrial) have alternative prey items external to their respective habitats. Such subsidized assemblages occupy a significant higher trophic position than assemblages in unsubsidized areas. Further, cross-habitat linkages are often pulsed; and even small pulses of a driver (e.g. short-term increases in flow) can cause major resource pulses (i.e. emerging aquatic insects) that control the recipient community. For example, short-term additions of resources, simulating pulsed inputs of aquatic food to terrestrial systems, suggest that due to resource partitioning and temporal separation among riparian arthropod taxa the resource flux from the river to the riparian zone increases with increasing riparian consumer diversity. I will discuss the multiple transfer and transformation processes of matter and organisms across aquatic-terrestrial habitats. Key landscape elements along river corridors are vegetated islands that function as instream riparian areas. Results from Central European rivers demonstrate that islands are in general more natural than fringing riparian areas, contribute substantially to total ecotone length, and create diverse habitats in the aquatic and terrestrial realm. In braided rivers, vegetated islands are highly productive landscape elements compared to the adjacent aquatic area. However, aquatic habitats exhibit a much higher decomposition

  17. Effect of inter-pulse delay time on production and size properties of colloidal nanoparticles prepared by collinear double-pulse laser ablation in liquid

    NASA Astrophysics Data System (ADS)

    Fattahi, Behzad; Mahdieh, Mohammah Hossein

    2016-08-01

    The influence of inter-pulse delay times (0–20 ns) between two collinear sequential nanosecond pulses on the production and size properties (mean size and size distribution) of colloidal nanoparticles prepared by pulsed laser ablation of a silver target in a distilled water medium has been studied. Various laser fluences at different inter-pulse delay times between two collinear pulses were used. Furthermore, for a better understanding of the effect of the double-pulse and single-pulse mode, experiments were performed. The characterization of the synthesized colloidal nanoparticles was investigated using scanning electron microscopy (SEM) and UV–vis absorption spectroscopy. Our results showed that 5 ns time-delayed double-pulse laser ablation results in the production of nanoparticles with the highest concentration among the other time-delayed ablation experiments and even more than single-pulse-mode experiments. It also found that using a double-pulse approach with inter-pulse delay times in the range of 0–20 ns leads to the production of nanoparticles with smaller mean sizes and narrower size distributions in comparison to single-pulse-mode laser ablation. The effect of time overlapping between two pulses in the case of double-pulse ablation was analyzed.

  18. Effect of inter-pulse delay time on production and size properties of colloidal nanoparticles prepared by collinear double-pulse laser ablation in liquid

    NASA Astrophysics Data System (ADS)

    Fattahi, Behzad; Mahdieh, Mohammah Hossein

    2016-08-01

    The influence of inter-pulse delay times (0-20 ns) between two collinear sequential nanosecond pulses on the production and size properties (mean size and size distribution) of colloidal nanoparticles prepared by pulsed laser ablation of a silver target in a distilled water medium has been studied. Various laser fluences at different inter-pulse delay times between two collinear pulses were used. Furthermore, for a better understanding of the effect of the double-pulse and single-pulse mode, experiments were performed. The characterization of the synthesized colloidal nanoparticles was investigated using scanning electron microscopy (SEM) and UV-vis absorption spectroscopy. Our results showed that 5 ns time-delayed double-pulse laser ablation results in the production of nanoparticles with the highest concentration among the other time-delayed ablation experiments and even more than single-pulse-mode experiments. It also found that using a double-pulse approach with inter-pulse delay times in the range of 0-20 ns leads to the production of nanoparticles with smaller mean sizes and narrower size distributions in comparison to single-pulse-mode laser ablation. The effect of time overlapping between two pulses in the case of double-pulse ablation was analyzed.

  19. 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.

  20. PULSE PROFILES FROM THERMALLY EMITTING NEUTRON STARS

    SciTech Connect

    Turolla, R.; Nobili, L.

    2013-05-10

    The problem of computing the pulse profiles from thermally emitting spots on the surface of a neutron star in general relativity is reconsidered. We show that it is possible to extend Beloborodov's approach to include (multiple) spots of finite size in different positions on the star surface. The results for the pulse profiles are expressed by comparatively simple analytical formulae which involve only elementary functions.

  1. Ultrashort pulsed laser technology development program

    NASA Astrophysics Data System (ADS)

    Manke, Gerald C.

    2014-10-01

    The Department of Navy has been pursuing a technology development program for advanced, all-fiber, Ultra Short Pulsed Laser (USPL) systems via Small Business Innovative Research (SBIR) programs. Multiple topics have been published to promote and fund research that encompasses every critical component of a standard USPL system and enable the demonstration of mJ/pulse class systems with an all fiber architecture. This presentation will summarize published topics and funded programs.

  2. Community Structure Detection for Overlapping Modules through Mathematical Programming in Protein Interaction Networks

    PubMed Central

    Bennett, Laura; Kittas, Aristotelis; Liu, Songsong; Papageorgiou, Lazaros G.; Tsoka, Sophia

    2014-01-01

    Community structure detection has proven to be important in revealing the underlying properties of complex networks. The standard problem, where a partition of disjoint communities is sought, has been continually adapted to offer more realistic models of interactions in these systems. Here, a two-step procedure is outlined for exploring the concept of overlapping communities. First, a hard partition is detected by employing existing methodologies. We then propose a novel mixed integer non linear programming (MINLP) model, known as OverMod, which transforms disjoint communities to overlapping. The procedure is evaluated through its application to protein-protein interaction (PPI) networks of the rat, E. coli, yeast and human organisms. Connector nodes of hard partitions exhibit topological and functional properties indicative of their suitability as candidates for multiple module membership. OverMod identifies two types of connector nodes, inter and intra-connector, each with their own particular characteristics pertaining to their topological and functional role in the organisation of the network. Inter-connector proteins are shown to be highly conserved proteins participating in pathways that control essential cellular processes, such as proliferation, differentiation and apoptosis and their differences with intra-connectors is highlighted. Many of these proteins are shown to possess multiple roles of distinct nature through their participation in different network modules, setting them apart from proteins that are simply ‘hubs’, i.e. proteins with many interaction partners but with a more specific biochemical role. PMID:25412367

  3. Assessing the likely effectiveness of multispecies management for imperiled desert fishes with niche overlap analysis.

    PubMed

    Laub, Brian G; Budy, Phaedra

    2015-08-01

    A critical decision in species conservation is whether to target individual species or a complex of ecologically similar species. Management of multispecies complexes is likely to be most effective when species share similar distributions, threats, and response to threats. We used niche overlap analysis to assess ecological similarity of 3 sensitive desert fish species currently managed as an ecological complex. We measured the amount of shared distribution of multiple habitat and life history parameters between each pair of species. Habitat use and multiple life history parameters, including maximum body length, spawning temperature, and longevity, differed significantly among the 3 species. The differences in habitat use and life history parameters among the species suggest they are likely to respond differently to similar threats and that most management actions will not benefit all 3 species equally. Habitat restoration, frequency of stream dewatering, non-native species control, and management efforts in tributaries versus main stem rivers are all likely to impact each of the species differently. Our results demonstrate that niche overlap analysis provides a powerful tool for assessing the likely effectiveness of multispecies versus single-species conservation plans.

  4. Assessing the likely effectiveness of multispecies management for imperiled desert fishes with niche overlap analysis.

    PubMed

    Laub, Brian G; Budy, Phaedra

    2015-08-01

    A critical decision in species conservation is whether to target individual species or a complex of ecologically similar species. Management of multispecies complexes is likely to be most effective when species share similar distributions, threats, and response to threats. We used niche overlap analysis to assess ecological similarity of 3 sensitive desert fish species currently managed as an ecological complex. We measured the amount of shared distribution of multiple habitat and life history parameters between each pair of species. Habitat use and multiple life history parameters, including maximum body length, spawning temperature, and longevity, differed significantly among the 3 species. The differences in habitat use and life history parameters among the species suggest they are likely to respond differently to similar threats and that most management actions will not benefit all 3 species equally. Habitat restoration, frequency of stream dewatering, non-native species control, and management efforts in tributaries versus main stem rivers are all likely to impact each of the species differently. Our results demonstrate that niche overlap analysis provides a powerful tool for assessing the likely effectiveness of multispecies versus single-species conservation plans. PMID:25627117

  5. Assessing the likely effectiveness of multispecies management for imperiled desert fishes with niche overlap analysis

    USGS Publications Warehouse

    Laub, P; Budy, Phaedra

    2015-01-01

    A critical decision in species conservation is whether to target individual species or a complex of ecologically similar species. Management of multispecies complexes is likely to be most effective when species share similar distributions, threats, and response to threats. We used niche overlap analysis to assess ecological similarity of 3 sensitive desert fish species currently managed as an ecological complex. We measured the amount of shared distribution of multiple habitat and life history parameters between each pair of species. Habitat use and multiple life history parameters, including maximum body length, spawning temperature, and longevity, differed significantly among the 3 species. The differences in habitat use and life history parameters among the species suggest they are likely to respond differently to similar threats and that most management actions will not benefit all 3 species equally. Habitat restoration, frequency of stream dewatering, non-native species control, and management efforts in tributaries versus main stem rivers are all likely to impact each of the species differently. Our results demonstrate that niche overlap analysis provides a powerful tool for assessing the likely effectiveness of multispecies versus single-species conservation plans.

  6. Single and Multi-Pulse Low-Energy Conical Theta Pinch Inductive Pulsed Plasma Thruster Performance

    NASA Technical Reports Server (NTRS)

    Hallock, A. K.; Martin, A. K.; Polzin, K. A.; Kimberlin, A. C.; Eskridge, R. H.

    2013-01-01

    Impulse bits produced by conical theta-pinch inductive pulsed plasma thrusters possessing cone angles of 20deg, 38deg, and 60deg, were quantified for 500J/pulse operation by direct measurement using a hanging-pendulum thrust stand. All three cone angles were tested in single-pulse mode, with the 38deg model producing the highest impulse bits at roughly 1 mN-s operating on both argon and xenon propellants. A capacitor charging system, assembled to support repetitively-pulsed thruster operation, permitted testing of the 38deg thruster at a repetition-rate of 5 Hz at power levels of 0.9, 1.6, and 2.5 kW. The average thrust measured during multiple-pulse operation exceeded the value obtained when the single-pulse impulse bit is multiplied by the repetition rate.

  7. A Comparison of Overlap: ERIC and Psychological Abstracts.

    ERIC Educational Resources Information Center

    Caldwell, Jane; Ellingson, Celia

    1979-01-01

    Addresses the problem of overlap between the Educational Resources Information Center (ERIC) and Psychological Abstracts data bases, especially in areas of educational psychology. The article compares costs and article selection and offers guidelines for searchers based on duplication from test searches. (JD)

  8. The chronic obstructive pulmonary disease-asthma overlap syndrome.

    PubMed

    Braman, Sidney S

    2015-01-01

    When asthma and chronic obstructive pulmonary disease (COPD) occur together the term COPD-asthma overlap syndrome has been applied. To date, there is no universally accepted definition of this overlap syndrome, just as there is no blood test or other technologic assessment that provides a simple way to distinguish asthma from COPD. One practical approach to the overlap diagnosis has been to include patients with a diagnosis of COPD by Global Initiative for Chronic Obstructive Lung Disease criteria and asthma defined by subject report of a physician diagnosis of asthma before the age of 40 years. Alternatively, it includes patients who meet criteria for COPD (fixed airflow obstruction) and who also have typical features of asthma (wheezing, atopy, eosinophilia, and positive bronchodilator response on spirometry). Compared with patients with COPD alone, the overlap patients are younger with less smoking intensity, have higher health-care utilization, have a worse disease-related quality of life, and have a higher mortality. Treatment with corticosteroids earlier in the course of the disease compared with the patient with only COPD has been recommended.

  9. Track with overlapping links for dry coal extrusion pumps

    DOEpatents

    Saunders, Timothy; Brady, John D

    2014-01-21

    A chain for a particulate material extrusion pump includes a plurality of links, each of the plurality of links having a link body and a link ledge, wherein each link ledge of the plurality of links at least partially overlaps the link body of an adjacent one of the plurality of links.

  10. Australia's National Research Collection: Overlap, Uniqueness, and Distribution

    ERIC Educational Resources Information Center

    Genoni, Paul; Wright, Janette

    2011-01-01

    This paper reports on the results of an overlap study of Australian research library collections. The study used OCLC's WorldCat Collection Analysis software to mine data recording Australian holdings on the WorldCat database. The data is analysed according to the results obtained for six "groups" which represent various coalitions of academic,…

  11. Peer Network Overlap in Twin, Sibling, and Friend Dyads

    ERIC Educational Resources Information Center

    McGuire, Shirley; Segal, Nancy L.

    2013-01-01

    Research suggests that sibling–peer connections are important for understanding adolescent problem behaviors. Using a novel behavioral genetic design, the current study investigated peer network overlap in 300 child–child pairs (aged 7-13 years) in 5 dyad types: monozygotic (MZ), dizygotic twins, full siblings (FSs), friend pairs, and virtual…

  12. 9 CFR 121.4 - Overlap select agents and toxins.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... in paragraph (b) of this section that have been genetically modified. (d) Overlap select agents or... OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS POSSESSION, USE... elements, recombinant nucleic acids, and recombinant organisms: (1) Nucleic acids that can...

  13. 9 CFR 121.4 - Overlap select agents and toxins.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... this section that have been genetically modified. (d) Overlap select agents or toxins that meet any of... OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS POSSESSION, USE...) Genetic elements, recombinant and/or synthetic nucleic acids, and recombinant and/or synthetic...

  14. 9 CFR 121.4 - Overlap select agents and toxins.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... this section that have been genetically modified. (d) Overlap select agents or toxins that meet any of... OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS POSSESSION, USE...) Genetic elements, recombinant and/or synthetic nucleic acids, and recombinant and/or synthetic...

  15. 9 CFR 121.4 - Overlap select agents and toxins.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... in paragraph (b) of this section that have been genetically modified. (d) Overlap select agents or... OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS POSSESSION, USE... elements, recombinant nucleic acids, and recombinant organisms: (1) Nucleic acids that can...

  16. 42 CFR 73.4 - Overlap select agents and toxins.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... have been genetically modified. (d) Overlap select agents or toxins that meet any of the following... Elements, Recombinant and/or Synthetic Nucleic Acids, and Recombinant and/or Synthetic Organisms: (1... within the exclusion category. (e) An attenuated strain of a select agent, or a select toxin modified...

  17. 9 CFR 121.4 - Overlap select agents and toxins.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... in paragraph (b) of this section that have been genetically modified. (d) Overlap select agents or... OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS POSSESSION, USE... elements, recombinant nucleic acids, and recombinant organisms: (1) Nucleic acids that can...

  18. 14 CFR 71.9 - Overlapping airspace designations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Overlapping airspace designations. 71.9 Section 71.9 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRSPACE DESIGNATION OF CLASS A, B, C, D, AND E AIRSPACE AREAS; AIR TRAFFIC SERVICE ROUTES;...

  19. Action Learning and Organisation Development: Overlapping Fields of Practice

    ERIC Educational Resources Information Center

    Edmonstone, John

    2011-01-01

    This paper explores the relationship between action learning and Organisation Development (OD). It proposes that they are overlapping fields of practice, with interesting similarities and differences. Both fields of practice are experienced as challenging to conventional ways of viewing organisations and people but are also subject to increasing…

  20. Multisensory integration substantiates distributed and overlapping neural networks.

    PubMed

    Pasqualotto, Achille

    2016-01-01

    The hypothesis that highly overlapping networks underlie brain functions (neural reuse) is decisively supported by three decades of multisensory research. Multisensory areas process information from more than one sensory modality and therefore represent the best examples of neural reuse. Recent evidence of multisensory processing in primary visual cortices further indicates that neural reuse is a basic feature of the brain. PMID:27562234

  1. Fabrication and optical measurement of double-overlapped annular apertures

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Jiang, Xiaoxiao; Xia, Liangping; Tang, Linlong; Hu, Sheng; Lv, Jiangtao; Zhao, Hongquan; Si, Guangyuan; Shi, Ruiying

    2016-10-01

    We demonstrate double-overlapped annular aperture (DOAA) arrays fabricated in a gold film via focused ion beam milling. The high order resonance modes of DOAA are investigated both theoretically and experimentally. Polarization dependency is observed for DOAA arrays and lower order resonance modes in the mid-infrared range exhibit extraordinary optical transmission and dependency on geometric parameters.

  2. Overlapping Statistical Segmentation for Effective Indexing of Japanese Text.

    ERIC Educational Resources Information Center

    Ogawa, Yasushi; Matsuda, Toru

    1999-01-01

    Discusses statistical word indexing for Japanese information-retrieval systems and proposes a new method that uses statistics about characters to evaluate a bi-gram's likelihood of being a word boundary. Describes a new segmentation strategy that extracts some overlapping segments and results in higher retrieval effectiveness. (Author/LRW)

  3. Content Validity of Standardized Achievement Tests and Test Curriculum Overlap.

    ERIC Educational Resources Information Center

    Green, Donald Ross

    Discussions of "test curriculum overlap" that focus on the term "mismatch" tend to be based on several untenable premises. This paper addresses the issue of the degree to which standardized tests should reflect the specific content of a given school curriculum with regard to three points: (1) The idea of matching the content of standardized tests…

  4. A Longitudinal Assessment of the Victim-Offender Overlap

    ERIC Educational Resources Information Center

    Jennings, Wesley G.; Higgins, George E.; Tewksbury, Richard; Gover, Angela R.; Piquero, Alex R.

    2010-01-01

    Although research has established an offending/victimization overlap and that offenders and victims share similar characteristics, much less work has examined the longitudinal sequencing of victimization and offending in the same developmental period and whether key risk/protective factors significantly distinguish both offenders and victims. This…

  5. [Lichen ruber planus--lupus erythematosus/overlap syndrome].

    PubMed

    Stary, A; Schwarz, T; Duschet, P; Gschnait, F

    1987-03-01

    Lichen planus/lupus erythematosus/overlap syndrome (OS) comprises those dermatoses which show the clinical, histologic, and immunopathologic characteristics of both diseases. On account of this heterogeneity, the diagnosis of OS may be difficult. About 35 cases have been reported on in the literature so far. We are going to discuss the clinical, histologic, and immunofluorescence findings in OS in detail.

  6. High Rate Pulse Processing Algorithms for Microcalorimeters

    NASA Astrophysics Data System (ADS)

    Tan, Hui; Breus, Dimitry; Hennig, Wolfgang; Sabourov, Konstantin; Collins, Jeffrey W.; Warburton, William K.; Bertrand Doriese, W.; Ullom, Joel N.; Bacrania, Minesh K.; Hoover, Andrew S.; Rabin, Michael W.

    2009-12-01

    It has been demonstrated that microcalorimeter spectrometers based on superconducting transition-edge-sensors can readily achieve sub-100 eV energy resolution near 100 keV. However, the active volume of a single microcalorimeter has to be small in order to maintain good energy resolution, and pulse decay times are normally on the order of milliseconds due to slow thermal relaxation. Therefore, spectrometers are typically built with an array of microcalorimeters to increase detection efficiency and count rate. For large arrays, however, as much pulse processing as possible must be performed at the front end of readout electronics to avoid transferring large amounts of waveform data to a host computer for post-processing. In this paper, we present digital filtering algorithms for processing microcalorimeter pulses in real time at high count rates. The goal for these algorithms, which are being implemented in readout electronics that we are also currently developing, is to achieve sufficiently good energy resolution for most applications while being: a) simple enough to be implemented in the readout electronics; and, b) capable of processing overlapping pulses, and thus achieving much higher output count rates than those achieved by existing algorithms. Details of our algorithms are presented, and their performance is compared to that of the "optimal filter" that is currently the predominantly used pulse processing algorithm in the cryogenic-detector community.

  7. Ultrafast Nyquist OTDM demultiplexing using optical Nyquist pulse sampling in an all-optical nonlinear switch.

    PubMed

    Hirooka, Toshihiko; Seya, Daiki; Harako, Koudai; Suzuki, Daiki; Nakazawa, Masataka

    2015-08-10

    We propose the ultrahigh-speed demultiplexing of Nyquist OTDM signals using an optical Nyquist pulse as both a signal and a sampling pulse in an all-optical nonlinear switch. The narrow spectral width of the Nyquist pulses means that the spectral overlap between data and control pulses is greatly reduced, and the control pulse itself can be made more tolerant to dispersion and nonlinear distortions inside the nonlinear switch. We apply the Nyquist control pulse to the 640 to 40 Gbaud demultiplexing of DPSK and DQPSK signals using a nonlinear optical loop mirror (NOLM), and demonstrate a large performance improvement compared with conventional Gaussian control pulses. We also show that the optimum spectral profile of the Nyquist control pulse depends on the walk-off property of the NOLM.

  8. Noncollinear gating for high-flux isolated-attosecond-pulse generation

    NASA Astrophysics Data System (ADS)

    Zhong, Shiyang; He, Xinkui; Jiang, Yujiao; Teng, Hao; He, Peng; Liu, Yangyang; Zhao, Kun; Wei, Zhiyi

    2016-03-01

    We propose an approach for producing high-flux isolated-attosecond pulses (IAPs) based on noncollinear geometry of high-order harmonic generation (HHG). By combining a main driving pulse and an ultrashort gating pulse in the interaction medium to form a tilt wave front in a very narrow overlapping time region, the attosecond pulses generated in this region are spatially separated from the original beam in the far field. It gives a way of extracting IAPs as well as fully characterizing an attosecond-pulse train (APT). Since this approach set no restriction on the pulse duration of the main driving pulse, it is particularly suitable for high-flux IAP generation by a high-energy laser which usually has multicycle pulse duration.

  9. Minimal SNP overlap among multiple panels of ancestry informative markers argues for more international collaboration.

    PubMed

    Soundararajan, Usha; Yun, Libing; Shi, Meisen; Kidd, Kenneth K

    2016-07-01

    The century-old use of genetic markers to determine population relationships has morphed in modern forensics into use of markers to determine the ancestry of an individual from a DNA sample. Researchers have identified sets of SNPs that have frequency differences among populations and many sets of SNPs have been published for the purpose of inferring ancestry. Such inference also requires reference datasets for the particular set of SNPs selected. We have identified 21 largely independent published panels of ancestry informative SNPs (AISNPs) and examined their union of 1397 SNPs. No SNP occurs in more than 6 panels. The 1397 SNPs in 21 panels yield a largely empty matrix that is inhibiting progress on more refined ability to infer ancestry for a forensic sample. The most common set of reference populations is the HGDP set of 52 small population samples totaling a thousand individuals. Only 46 (3%) of the 1397 SNPs occur in three or more panels. We assembled a new dataset for 44 of those SNPs involving 4,559 individuals from 73 populations. Analyses of this dataset provided clear differentiation of only five biogeographic regions: sub-Saharan Africa, Europe and SW Asia, South Asia, East Asia, and the Americas. This is an inadequate level of biogeographic resolution already exceeded by other panels. We conclude that more such AISNP panels are not needed and that the forensic community must collaborate to develop a common set of highly differentiating AISNPs typed on a very large number of population samples. How that can be accomplished will be the subject of future discussion. PMID:26977931

  10. Multiple modes of clearing one’s mind of current thoughts: Overlapping and distinct neural systems

    PubMed Central

    Banich, Marie T.; Mackiewicz Seghete, Kristen L.; Depue, Brendan E.; Burgess, Gregory C.

    2015-01-01

    This study used the power of neuroimaging to identify the neural systems that remove information from working memory, a thorny issue to examine because it is difficult to confirm that individuals have actually modified their thoughts. To overcome this problem, brain activation as measured via fMRI was assessed when individuals had to clear their mind of all thought (global clear), clear their mind of a particular thought (targeted clear), or replace the current thought (replace), relative to maintaining an item in working memory. The pattern of activity in posterior sensory regions across these conditions confirmed compliance with task demands. A hierarchy of brain regions involved in cognitive control, including parietal, dorsolateral prefrontal and frontopolar regions, were engaged to varying degrees depending on the manner in which information was removed from working memory. In addition, individuals with greater difficulty in controlling internal thoughts exhibited greater activity in prefrontal brain regions associated with cognitive control, as well as in left lateral prefrontal areas including Broca’s area, which is associated with inner speech. PMID:25637772

  11. Method for simultaneous overlapped communications between neighboring processors in a multiple

    DOEpatents

    Benner, Robert E.; Gustafson, John L.; Montry, Gary R.

    1991-01-01

    A parallel computing system and method having improved performance where a program is concurrently run on a plurality of nodes for reducing total processing time, each node having a processor, a memory, and a predetermined number of communication channels connected to the node and independently connected directly to other nodes. The present invention improves performance of performance of the parallel computing system by providing a system which can provide efficient communication between the processors and between the system and input and output devices. A method is also disclosed which can locate defective nodes with the computing system.

  12. Chirped-pulse amplification with narrowband pulses.

    PubMed

    Shverdin, M Y; Albert, F; Anderson, S G; Betts, S M; Gibson, D J; Messerly, M J; Hartemann, F V; Siders, C W; Barty, C P J

    2010-07-15

    We demonstrate a compact hyperdispersion stretcher and compressor pair that permit chirped-pulse amplification in Nd:YAG. We generate 750 mJ, 0.2 nm FWHM, 10 Hz pulses recompressed to an 8 ps near-transform-limited duration. The dispersion-matched pulse compressor and stretcher impart a chirp of 7300 ps/nm, in a 3 m x 1 m footprint.

  13. Chirped-pulse amplification with narrowband pulses.

    PubMed

    Shverdin, M Y; Albert, F; Anderson, S G; Betts, S M; Gibson, D J; Messerly, M J; Hartemann, F V; Siders, C W; Barty, C P J

    2010-07-15

    We demonstrate a compact hyperdispersion stretcher and compressor pair that permit chirped-pulse amplification in Nd:YAG. We generate 750 mJ, 0.2 nm FWHM, 10 Hz pulses recompressed to an 8 ps near-transform-limited duration. The dispersion-matched pulse compressor and stretcher impart a chirp of 7300 ps/nm, in a 3 m x 1 m footprint. PMID:20634869

  14. Ultrasound vibrometry using orthogonal- frequency-based vibration pulses.

    PubMed

    Zheng, Yi; Yao, Aiping; Chen, Shigao; Urban, Matthew W; Lin, Haoming; Chen, Xin; Guo, Yanrong; Chen, Ke; Wang, Tianfu; Chen, Siping

    2013-11-01

    New vibration pulses are developed for shear wave generation in a tissue region with preferred spectral distributions for ultrasound vibrometry applications. The primary objective of this work is to increase the frequency range of detectable harmonics of the shear wave. The secondary objective is to reduce the required peak intensity of transmitted pulses that induce the vibrations and shear waves. Unlike the periodic binary vibration pulses, the new vibration pulses have multiple pulses in one fundamental period of the vibration. The pulses are generated from an orthogonal-frequency wave composed of several sinusoidal signals, the amplitudes of which increase with frequency to compensate for higher loss at higher frequency in tissues. The new method has been evaluated by studying the shear wave propagation in in vitro chicken and swine liver. The experimental results show that the new vibration pulses significantly increase tissue vibration with a reduced peak ultrasound intensity, compared with the binary vibration pulses.

  15. DIFFERENTIAL PULSE HEIGHT DISCRIMINATOR

    DOEpatents

    Test, L.D.

    1958-11-11

    Pulse-height discriminators are described, specifically a differential pulse-height discriminator which is adapted to respond to pulses of a band of amplitudes, but to reject pulses of amplitudes greater or less than tbe preselected band. In general, the discriminator includes a vacuum tube having a plurality of grids adapted to cut off plate current in the tube upon the application of sufficient negative voltage. One grid is held below cutoff, while a positive pulse proportional to the amplltude of each pulse is applled to this grid. Another grid has a negative pulse proportional to the amplitude of each pulse simultaneously applied to it. With this arrangement the tube will only pass pulses which are of sufficlent amplitude to counter the cutoff bias but not of sufficlent amplitude to cutoff the tube.

  16. A modeling approach to explain pulse design in bats.

    PubMed

    Boonman, Arjan; Ostwald, Joachim

    2007-08-01

    In this modeling study we wanted to find out why bats of the family Vespertilionidae (and probably also members of other families of bats) use pulses with a certain bandwidth and duration. Previous studies have only speculated on the function of bandwidth and pulse duration in bat echolocation or addressed this problem by assuming that bats optimize echolocation parameters to achieve very fine acuities in receiving single echoes. Here, we take a different approach by assuming that bats in nature rarely receive single echoes from each pulse emission, but rather many highly overlapping echoes. Some echolocation tasks require individual echoes to be separated to reconstruct reflection points in space. We used an established hearing model to investigate how the parameters bandwidth and pulse duration influence the separation of overlapping echoes. Our findings corroborate the following previously unknown or unsubstantiated facts: 1. Broadening the bandwidth improves the bat's lower resolution limit. 2. Increasing the sweep rate (defined by bandwidth and pulse duration) improves acuity of each extracted echo. 3. Decreasing the sweep rate improves the probability of frequency channels being activated. Since facts 2 and 3 affect sweep rate in an opposing fashion, an optimum sweep rate will exist, depending on the quality of the returning echoes and the requirements of the bat to improve acuity. The existence of an optimal sweep rate explains why bats are likely to use certain combinations of bandwidth and pulse duration to obtain such sweep rates.

  17. A BROADBAND RADIO STUDY OF THE AVERAGE PROFILE AND GIANT PULSES FROM PSR B1821-24A

    SciTech Connect

    Bilous, A. V.; Demorest, P.; Ransom, S. M.

    2015-04-20

    We present the results of a wideband (720–2400 MHz) study of PSR B1821–24A (J1824–2452A, M28A), an energetic millisecond pulsar (MSP) visible in radio, X-rays and γ-rays. In radio, the pulsar has a complex average profile that spans ≳85% of the spin period and exhibits strong evolution with observing frequency. For the first time we measure phase-resolved polarization properties and spectral indices of radio emission throughout almost all of the on-pulse window. We synthesize our findings with high-energy information to compare M28A to other known γ-ray MSPs and to speculate that M28A’s radio emission originates in multiple regions within its magnetosphere (i.e., both in the slot or outer gaps near the light cylinder and at lower altitudes above the polar cap). M28A is one of a handful of pulsars that are known to emit giant radio pulses (GRPs)—short, bright radio pulses of unknown nature. We report a drop in the linear polarization of the average profile in both windows of GRP generation and also a “W”-shaped absorption feature (resembling a double notch), partly overlapping with one of the GRP windows. The GRPs themselves have broadband spectra consisting of multiple patches with Δν/ν ∼ 0.07. Although our time resolution was not sufficient to resolve the GRP structure on the μs scale, we argue that GRPs from this pulsar most closely resemble the GRPs from the main pulse of the Crab pulsar, which consist of a series of narrowband nanoshots.

  18. Pulse shape adjustment for the SLC damping ring kickers

    SciTech Connect

    Mattison, T.; Cassel, R.; Donaldson, A.; Fischer, H.; Gough, D.

    1991-05-01

    The difficulties with damping ring kickers that prevented operation of the SLAC Linear Collider in full multiple bunch mode have been overcome by shaping the current pulse to compensate for imperfections in the magnets. The risetime was improved by a peaking capacitor, with a tunable inductor to provide a locally flat pulse. The pulse was flattened by an adjustable droop inductor. Fine adjustment was provided by pulse forming line tuners driven by stepping motors. Further risetime improvement will be obtained by a saturating ferrite pulse sharpener. 4 refs., 3 figs.

  19. A comparative study of novel spectrophotometric resolution techniques applied for pharmaceutical mixtures with partially or severely overlapped spectra

    NASA Astrophysics Data System (ADS)

    Lotfy, Hayam M.; Tawakkol, Shereen M.; Fahmy, Nesma M.; Shehata, Mostafa A.

    2015-02-01

    Simultaneous determination of mixtures of lidocaine hydrochloride (LH), flucortolone pivalate (FCP), in presence of chlorquinaldol (CQ) without prior separation steps was applied using either successive or progressive resolution techniques. According to the concentration of CQ the extent of overlapping changed so it can be eliminated from the mixture to get the binary mixture of LH and FCP using ratio subtraction method for partially overlapped spectra or constant value via amplitude difference followed by ratio subtraction or constant center followed by spectrum subtraction spectrum subtraction for severely overlapped spectra. Successive ratio subtraction was coupled with extended ratio subtraction, constant multiplication, derivative subtraction coupled constant multiplication, and spectrum subtraction can be applied for the analysis of partially overlapped spectra. On the other hand severely overlapped spectra can be analyzed by constant center and the novel methods namely differential dual wavelength (D1 DWL) for CQ, ratio difference and differential derivative ratio (D1 DR) for FCP, while LH was determined by applying constant value via amplitude difference followed by successive ratio subtraction, and successive derivative subtraction. The spectra of the cited drugs can be resolved and their concentrations are determined progressively from the same ratio spectrum using amplitude modulation method. The specificity of the developed methods was investigated by analyzing laboratory prepared mixtures and were successfully applied for the analysis of pharmaceutical formulations containing the cited drugs with no interference from additives. The proposed methods were validated according to the ICH guidelines. The obtained results were statistically compared with those of the official or reported methods; using student t-test, F-test, and one way ANOVA, showing no significant difference with respect to accuracy and precision.

  20. Laser pulse stacking method

    DOEpatents

    Moses, E.I.

    1992-12-01

    A laser pulse stacking method is disclosed. A problem with the prior art has been the generation of a series of laser beam pulses where the outer and inner regions of the beams are generated so as to form radially non-synchronous pulses. Such pulses thus have a non-uniform cross-sectional area with respect to the outer and inner edges of the pulses. The present invention provides a solution by combining the temporally non-uniform pulses in a stacking effect to thus provide a more uniform temporal synchronism over the beam diameter. 2 figs.

  1. Nerve-pulse interactions

    SciTech Connect

    Scott, A.C.

    1982-01-01

    Some recent experimental and theoretical results on mechanisms through which individual nerve pulses can interact are reviewed. Three modes of interactions are considered: (1) interaction of pulses as they travel along a single fiber which leads to velocity dispersion; (2) propagation of pairs of pulses through a branching region leading to quantum pulse code transformations; and (3) interaction of pulses on parallel fibers through which they may form a pulse assembly. This notion is analogous to Hebb's concept of a cell assembly, but on a lower level of the neural hierarchy.

  2. Performance investigation of the pulse and Campbelling modes of a fission chamber using a Poisson pulse train simulation code

    NASA Astrophysics Data System (ADS)

    Elter, Zs.; Jammes, C.; Pázsit, I.; Pál, L.; Filliatre, P.

    2015-02-01

    The detectors of the neutron flux monitoring system of the foreseen French GEN-IV sodium-cooled fast reactor (SFR) will be high temperature fission chambers placed in the reactor vessel in the vicinity of the core. The operation of a fission chamber over a wide-range neutron flux will be feasible provided that the overlap of the applicability of its pulse and Campbelling operational modes is ensured. This paper addresses the question of the linearity of these two modes and it also presents our recent efforts to develop a specific code for the simulation of fission chamber pulse trains. Our developed simulation code is described and its overall verification is shown. An extensive quantitative investigation was performed to explore the applicability limits of these two standard modes. It was found that for short pulses the overlap between the pulse and Campbelling modes can be guaranteed if the standard deviation of the background noise is not higher than 5% of the pulse amplitude. It was also shown that the Campbelling mode is sensitive to parasitic noise, while the performance of the pulse mode is affected by the stochastic amplitude distributions.

  3. Overview of The Pulse Line Ion Accelerator

    SciTech Connect

    Briggs, R.J.; Bieniosek, F.M.; Coleman, J.E.; Eylon, S.; Henestroza, E.; Leitner, M.; Logan, B.G.; Reginato, L.L.; Roy, P.K.; Seidl, P.A.; Waldron, W.L.; Yu, S.S.; Barnard, J.J.; Caporaso, G.J.; Friedman, A.; Grote, D.P.; Nelson, S.D.

    2006-06-29

    An overview of the Pulse Line Ion Accelerator (PLIA) concept and its development is presented. In the PLIA concept a pulse power driver applied to one end of a helical pulse line creates a traveling wave pulse that accelerates and axially confines a heavy ion beam pulse The motivation for its development at the IFE-VNL is the acceleration of intense, short pulse, heavy ion beams to regimes of interest for studies of High Energy Density Physics and Warm Dense Matter. Acceleration scenarios with constant parameter helical lines are described which result in output energies of a single stage much larger than the several hundred kilovolt peak voltages on the line, with a goal of 3-5 MeV/meter acceleration gradients. The main attraction of the concept is the very low cost it promises. It might be described crudely as an ''air core'' induction linac where the pulse-forming network is integrated into the beam line so the accelerating voltage pulse can move along with the ions to get voltage multiplication.

  4. a Non-Overlapping Discretization Method for Partial Differential Equations

    NASA Astrophysics Data System (ADS)

    Rosas-Medina, A.; Herrera, I.

    2013-05-01

    Mathematical models of many systems of interest, including very important continuous systems of Engineering and Science, lead to a great variety of partial differential equations whose solution methods are based on the computational processing of large-scale algebraic systems. Furthermore, the incredible expansion experienced by the existing computational hardware and software has made amenable to effective treatment problems of an ever increasing diversity and complexity, posed by engineering and scientific applications. The emergence of parallel computing prompted on the part of the computational-modeling community a continued and systematic effort with the purpose of harnessing it for the endeavor of solving boundary-value problems (BVPs) of partial differential equations. Very early after such an effort began, it was recognized that domain decomposition methods (DDM) were the most effective technique for applying parallel computing to the solution of partial differential equations, since such an approach drastically simplifies the coordination of the many processors that carry out the different tasks and also reduces very much the requirements of information-transmission between them. Ideally, DDMs intend producing algorithms that fulfill the DDM-paradigm; i.e., such that "the global solution is obtained by solving local problems defined separately in each subdomain of the coarse-mesh -or domain-decomposition-". Stated in a simplistic manner, the basic idea is that, when the DDM-paradigm is satisfied, full parallelization can be achieved by assigning each subdomain to a different processor. When intensive DDM research began much attention was given to overlapping DDMs, but soon after attention shifted to non-overlapping DDMs. This evolution seems natural when the DDM-paradigm is taken into account: it is easier to uncouple the local problems when the subdomains are separated. However, an important limitation of non-overlapping domain decompositions, as that

  5. Pulsed response of a TWT

    NASA Technical Reports Server (NTRS)

    May, Brian D.

    1991-01-01

    The consequence of frequency domain multiple access channelization in a satellite communications system is that the ground- and space-based components often are required to operate in a linear region to prevent the generation of distortion signals. Components of a time division multiple access (TDMA) satellite system, such as a traveling-wave tube (TWT), can operate in the highest output power state because the channelization technique is relatively insensitive to the distortions resulting from saturated operation. A 30 GHz TWT was tested to determine the suitability of such a device in a TDMA system. Testing was focused on the ability of the TWT's output signal to rise up to full power at the leading edge of TDMA bursts, simulated by a pulse train. A peak power meter was used to display and measure the pulsed signal waveform. Measurements on the TWT output pulse rise time indicate that the TWT lengthened the rise time by 10 to 20 ns. Imposing modulator turn on timing that precedes the data burst by the TWT rise time is a logical approach to coordination of the two subsystem specification.

  6. 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.

  7. Clicks, whistles and pulses: Passive and active signal use in dolphin communication

    NASA Astrophysics Data System (ADS)

    Herzing, Denise L.

    2014-12-01

    The search for signals out of noise is a problem not only with radio signals from the sky but in the study of animal communication. Dolphins use multiple modalities to communicate including body postures, touch, vision, and most elaborately sound. Like SETI radio signal searches, dolphin sound analysis includes the detection, recognition, analysis, and interpretation of signals. Dolphins use both passive listening and active production to communicate. Dolphins use three main types of acoustic signals: frequency modulated whistles (narrowband with harmonics), echolocation (broadband clicks) and burst pulsed sounds (packets of closely spaced broadband clicks). Dolphin sound analysis has focused on frequency-modulated whistles, yet the most commonly used signals are burst-pulsed sounds which, due to their graded and overlapping nature and bimodal inter-click interval (ICI) rates are hard to categorize. We will look at: 1) the mechanism of sound production and categories of sound types, 2) sound analysis techniques and information content, and 3) examples of lessons learned in the study of dolphin acoustics. The goal of this paper is to provide perspective on how animal communication studies might provide insight to both passive and active SETI in the larger context of searching for life signatures.

  8. CARS imaging with a single laser pulse

    NASA Astrophysics Data System (ADS)

    Heinrich, Christoph; Bernet, Stefan; Ritsch-Marte, Monika

    2005-09-01

    We report coherent anti-Stokes Raman scattering (CARS) microscopy with ns-pulses. The chosen wide-field geometry allows imaging of the whole field of view at once, without scanning of the sample. Tuning the difference of the two incident laser frequencies overlapping at the sample to a specific vibrational level, one can map the spatial distribution of selected Raman active molecules. Both the CARS signal of the surrounding solvent can be excited (negative contrast) as well as the signal of the structure embedded by the solvent (positive contrast). As a biological sample we used slices of a sunflower seed and tuned to the vibrational transition of its ingredient - linoleic acid - at 2870 cm-1 which corresponds to the strongest C-H stretching vibration. Even with a single pair of laser pulses of 3 ns duration it was possible to acquire a rough, but still meaningful image.

  9. Multiple quantum coherence spectroscopy.

    PubMed

    Mathew, Nathan A; Yurs, Lena A; Block, Stephen B; Pakoulev, Andrei V; Kornau, Kathryn M; Wright, John C

    2009-08-20

    Multiple quantum coherences provide a powerful approach for studies of complex systems because increasing the number of quantum states in a quantum mechanical superposition state increases the selectivity of a spectroscopic measurement. We show that frequency domain multiple quantum coherence multidimensional spectroscopy can create these superposition states using different frequency excitation pulses. The superposition state is created using two excitation frequencies to excite the symmetric and asymmetric stretch modes in a rhodium dicarbonyl chelate and the dynamic Stark effect to climb the vibrational ladders involving different overtone and combination band states. A monochromator resolves the free induction decay of different coherences comprising the superposition state. The three spectral dimensions provide the selectivity required to observe 19 different spectral features associated with fully coherent nonlinear processes involving up to 11 interactions with the excitation fields. The different features act as spectroscopic probes of the diagonal and off-diagonal parts of the molecular potential energy hypersurface. This approach can be considered as a coherent pump-probe spectroscopy where the pump is a series of excitation pulses that prepares a multiple quantum coherence and the probe is another series of pulses that creates the output coherence. PMID:19507812

  10. Expertise increases the functional overlap between face and object perception.

    PubMed

    McKeeff, Thomas J; McGugin, Rankin W; Tong, Frank; Gauthier, Isabel

    2010-12-01

    Recent studies indicate that expertise with objects can interfere with face processing. Although competition occurs between faces and objects of expertise, it remains unclear whether this reflects an expertise-specific bottleneck or the fact that objects of expertise grab attention and thereby consume more central resources. We investigated the perceptual costs of expertise by measuring visual thresholds for identifying targets embedded within RSVP sequences presented at varying temporal rates. Car experts and novices searched for face targets among face and car distractors, or watch targets among watch and car distractors. Remarkably, car experts were slower than novices at identifying faces among task-irrelevant cars, yet faster than novices at identifying watches among cars. This suggests that car expertise leads to greater functional overlap between cars and faces while reducing the functional overlap between cars and objects, a result incompatible with the notion of an encapsulated module for exclusive processing of faces.

  11. Genomic and functional overlap between somatic and germline chromosomal rearrangements.

    PubMed

    van Heesch, Sebastiaan; Simonis, Marieke; van Roosmalen, Markus J; Pillalamarri, Vamsee; Brand, Harrison; Kuijk, Ewart W; de Luca, Kim L; Lansu, Nico; Braat, A Koen; Menelaou, Androniki; Hao, Wensi; Korving, Jeroen; Snijder, Simone; van der Veken, Lars T; Hochstenbach, Ron; Knegt, Alida C; Duran, Karen; Renkens, Ivo; Alekozai, Najla; Jager, Myrthe; Vergult, Sarah; Menten, Björn; de Bruijn, Ewart; Boymans, Sander; Ippel, Elly; van Binsbergen, Ellen; Talkowski, Michael E; Lichtenbelt, Klaske; Cuppen, Edwin; Kloosterman, Wigard P

    2014-12-24

    Genomic rearrangements are a common cause of human congenital abnormalities. However, their origin and consequences are poorly understood. We performed molecular analysis of two patients with congenital disease who carried de novo genomic rearrangements. We found that the rearrangements in both patients hit genes that are recurrently rearranged in cancer (ETV1, FOXP1, and microRNA cluster C19MC) and drive formation of fusion genes similar to those described in cancer. Subsequent analysis of a large set of 552 de novo germline genomic rearrangements underlying congenital disorders revealed enrichment for genes rearranged in cancer and overlap with somatic cancer breakpoints. Breakpoints of common (inherited) germline structural variations also overlap with cancer breakpoints but are depleted for cancer genes. We propose that the same genomic positions are prone to genomic rearrangements in germline and soma but that timing and context of breakage determines whether developmental defects or cancer are promoted. PMID:25497101

  12. Disentangling mode-specific reaction dynamics from overlapped images.

    PubMed

    Yan, Shannon Shiuan; Wu, Yen-Tien; Liu, Kopin

    2007-01-14

    The hydrogen abstraction reaction between atomic chlorine and C-H stretch-excited CHD(3) was studied under crossed-beam conditions. Prior to collisions, an infrared (IR) laser was used to pump up a fraction of CHD(3) to nu(1) = 1. A time-sliced velocity imaging technique was exploited to image the recoil velocity distribution of the state-selected product CD(3)(nu = 0). For energetic reasons, the IR-on image shows severely overlapped features arising from both the excited and the un-pumped ground-state reagents. A novel threshold method was then developed to directly determine the fraction of IR-excited CHD(3) reagents, which in turn enables us to disentangle the state-selected dynamics from the overlapped images. The results reveal significant differences from previous experimental reports.

  13. Micropattern-Guided Assembly of Overlapping Pairs of Dynamic Microtubules

    PubMed Central

    Fourniol, Franck J.; Li, Tai-De; Bieling, Peter; Mullins, R. Dyche; Fletcher, Daniel A.; Surrey, Thomas

    2014-01-01

    Interactions between antiparallel microtubules are essential for the organization of spindles in dividing cells. The ability to form immobilized antiparallel microtubule pairs in vitro, combined with the ability to image them via TIRF microscopy, permits detailed biochemical characterization of microtubule cross-linking proteins and their effects on microtubule dynamics. Here, we describe methods for chemical micropatterning of microtubule seeds on glass surfaces in configurations that specifically promote the formation of antiparallel microtubule overlaps in vitro. We demonstrate that this assay is especially well suited for reconstitution of minimal midzone overlaps stabilized by the antiparallel microtubule cross-linking protein PRC1 and its binding partners. The micropatterning method is suitable for use with a broad range of proteins, and the assay is generally applicable to any microtubule cross-linking protein. PMID:24630116

  14. Phenotype of asthma-chronic obstructive pulmonary disease overlap syndrome.

    PubMed

    Rhee, Chin Kook

    2015-07-01

    Many patients with asthma or chronic obstructive pulmonary disease (COPD) have overlapping characteristics of both diseases. By spirometric definition, patients with both fixed airflow obstruction (AO) and bronchodilator reversibility or fixed AO and bronchial hyperresponsiveness can be considered to have asthma-COPD overlap syndrome (ACOS). However, patients regarded to have ACOS by spirometric criteria alone are heterogeneous and can be classified by phenotype. Eosinophilic inflammation, a history of allergic disease, and smoke exposure are important components in the classification of ACOS. Each phenotype has a different underlying pathophysiology, set of characteristics, and prognosis. Medical treatment for ACOS should be tailored according to phenotype. A narrower definition of ACOS that includes both spirometric and clinical criteria is needed.

  15. Discriminating crop and other canopies by overlapping binary image layers

    NASA Astrophysics Data System (ADS)

    Doi, Ryoichi

    2013-02-01

    For optimal management of agricultural fields by remote sensing, discrimination of the crop canopy from weeds and other objects is essential. In a digital photograph, a rice canopy was discriminated from a variety of weed and tree canopies and other objects by overlapping binary image layers of red-green-blue and other color components indicating the pixels with target canopy-specific (intensity) values based on the ranges of means ±(3×) standard deviations. By overlapping and merging the binary image layers, the target canopy specificity improved to 0.0015 from 0.027 for the yellow 1× standard deviation binary image layer, which was the best among all combinations of color components and means ±(3×) standard deviations. The most target rice canopy-likely pixels were further identified by limiting the pixels at different luminosity values. The discriminatory power was also visually demonstrated in this manner.

  16. Thermodynamics of the ideal overlap quarks on the lattice

    SciTech Connect

    Banerjee, Debasish; Gavai, R. V.; Sharma, Sayantan

    2008-07-01

    The thermodynamics of massless ideal gas of overlap quarks has been investigated both analytically and numerically for both zero and nonzero baryon chemical potential. Any {mu}{sup 2} divergence is shown analytically to be absent for a class of actions with nonzero chemical potential. All such actions are shown to violate chiral invariance. While the parameter M can be shown to be irrelevant in the continuum limit, as expected, it is shown numerically that the continuum limit can be reached with relatively coarser lattices for 1.5{<=}M{<=}1.6. Numerical limitations of the existing method of introduction of chemical potential are demonstrated. Finally we also show that the energy density for the massive overlap fermions has the correct continuum limit.

  17. Overture: An Object-Oriented Framework for Overlapping Grid Applications

    SciTech Connect

    Henshaw, W.D.

    2002-04-04

    The Overture framework is an object-oriented environment for solving partial differential equations on over-lapping grids. We describe some of the tools in Overture that can be used to generate grids and solve partial differential equations (PDEs). Overture contains a collection of C++ classes that can be used to write PDE solvers either at a high level or at a lower level for efficiency. There are also a number of tools provided with Overture that can be used with no programming effort. These tools include capabilities to: repair computer-aided-design (CAD) geometries and build global surface triangulations; generate surface and volume grids with hyperbolic grid generation; generate composite overlapping grids; generate hybrid (unstructured) grids; and solve particular PDEs such as the incompressible and compressible Navier-Stokes equations.

  18. DISENTANGLING OVERLAPPING ASTRONOMICAL SOURCES USING SPATIAL AND SPECTRAL INFORMATION

    SciTech Connect

    Jones, David E.; Kashyap, Vinay L.; Van Dyk, David A.

    2015-08-01

    We present a powerful new algorithm that combines both spatial information (event locations and the point-spread function) and spectral information (photon energies) to separate photons from overlapping sources. We use Bayesian statistical methods to simultaneously infer the number of overlapping sources, to probabilistically separate the photons among the sources, and to fit the parameters describing the individual sources. Using the Bayesian joint posterior distribution, we are able to coherently quantify the uncertainties associated with all these parameters. The advantages of combining spatial and spectral information are demonstrated through a simulation study. The utility of the approach is then illustrated by analysis of observations of FK Aqr and FL Aqr with the XMM-Newton Observatory and the central region of the Orion Nebula Cluster with the Chandra X-ray Observatory.

  19. Pin diode calibration - beam overlap monitoring for low energy cooling

    SciTech Connect

    Drees, A.; Montag, C.; Thieberger, P.

    2015-09-30

    We were trying to address the question whether or not the Pin Diodes, currently installed approximately 1 meter downstream of the RHIC primary collimators, are suitable to monitor a recombination signal from the future RHIC low energy cooling section. A maximized recombination signal, with the Au+78 ions being lost on the collimator, will indicate optimal Au-electron beam overlap as well as velocity matching of the electron beam in the cooling section.

  20. Bilateral coxitis in scleroderma-polymyositis overlap syndrome

    PubMed Central

    Berrada, Khadija; Abourazzak, Fatima Ezzahra; Houssaini, Ghita Sqalli; Kadi, Nadira; Tahiri, Latifa; Amrani, Kawthar; Khammar, Zineb; Lahlou, Meriam; Berrady, Rhizlane; Rabhi, Samira; Tizniti, Siham; Bono, Wafaa; Harzy, Taoufik

    2014-01-01

    Joint manifestations in scleroderma (Scl) and polymyositis (PM) are dominated by inflammatory arthralgia. Arthritis is less common and preferentially affects the hands, wrists, knees, and ankles. Involvement of the hip has been rarely reported in the literature. We report a case of coxitis diagnosed in a patient suffering from scleroderma-polymyositis overlap syndrome successfully treated by ultrasound-guided infiltration of triamcinolone hexacetonide PMID:27708891