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Sample records for phase lar large

  1. Designs of Large Liquid Argon TPCs - from MicroBooNE to LBNE LAr40

    NASA Astrophysics Data System (ADS)

    Yu, B.; Makowiecki, D. S.; Mahler, G. J.; Radeka, V.; Thorn, C.; Baller, B.; Jostlein, H.; Fleming, B. T.

    Liquid argon time projection chamber (LArTPC) is a unique technology well suited for large scale detectors of neutrinos and other rare processes. Its combination of millimeter scale 3D precision particle tracking and calorimetry with good dE/dx resolution provide excellent efficiency of particle identification and background rejection. MicroBooNE is a LArTPC about to enter its final design phase and is scheduled for construction in 2012. Its active volume contains 86 ton of LAr. It has a 2.6m drift distance, 8256 sense wires connected to cold CMOS analog front-end electronics. Most of the TPC design features improve upon existing tried and true techniques. The LAr40 is one of the two far detector options under consideration for the Long Baseline Neutrino Experiment (LBNE). Its conceptual design has 40 kton active liquid argon mass, to be installed underground at a moderate depth. Due to its large scale, and underground siting, great emphasis was placed on the detector cost and reliability. A modular TPC design is the key to achieve these goals. The LAr40 consists of two 20 kton detectors in one underground cavern. Each detector is in turn constructed from an array of TPC modules. Innovative concepts enable the modules to be tiled with minimal dead space. An overview of both detectors is presented. The designs of key elements in these two TPCs are described in detail.

  2. Wire-Cell Tomographic Event Reconstruction for large LArTPCs

    NASA Astrophysics Data System (ADS)

    Qian, Xin; Viren, Brett; Zhang, Chao; Wire-Cell Team

    2016-03-01

    Event reconstruction is one of the most challenging tasks in analyzing the data from current and future large liquid argon time projection chambers (LArTPCs). The performance of the event reconstruction holds the key to many potential future discoveries with the LArTPC technology including i) searching for new CP violation in the leptonic sector, ii) determining the neutrino mass hierarchy, and iii) searching for additional light (sterile) neutrino species. In this talk, we introduce a new reconstruction method: Wire-Cell. The principle of Wire-Cell strictly follows the principle of LArTPC, that is, the same amount of ionization electrons are observed by all the wire-planes. Using both time and charge information, 3D image of the event topologies are firstly obtained. Further reconstruction steps including the clustering, tracking, and particle identifications (PID) are then directly applied to the 3D image. The principle, current status, and future development plan of Wire-Cell will be described. The results of Wire-Cell event reconstruction will be shown with an innovative web-based ``BEE'' 3D event display. This work is supported by U.S. Department of Energy, Office of Science, Office of High Energy Physics and Early Career Research program under Contract Number DE-SC0012704.

  3. Lars Onsager Prize: Topological Defects in Condensed Matter Phases

    NASA Astrophysics Data System (ADS)

    Mineev, Vladimir

    2014-03-01

    Circulation quantization in superfluid 4He and superconductors. General principles of classification of topologically stable defects in ordered media. Superfluid phases of 3He. Topology at different scales of length. Superfluids under rotation. Biaxial nematics. Nonabelian disclinations. Half-quantum vortices: 3He-A, Sr2RuO4, exciton-polariton condensates, FFLO, Super Solid.

  4. The big fat LARS - a LArge Reservoir Simulator for hydrate formation and gas production

    NASA Astrophysics Data System (ADS)

    Beeskow-Strauch, Bettina; Spangenberg, Erik; Schicks, Judith M.; Giese, Ronny; Luzi-Helbing, Manja; Priegnitz, Mike; Klump, Jens; Thaler, Jan; Abendroth, Sven

    2013-04-01

    Simulating natural scenarios on lab scale is a common technique to gain insight into geological processes with moderate effort and expenses. Due to the remote occurrence of gas hydrates, their behavior in sedimentary deposits is largely investigated on experimental set ups in the laboratory. In the framework of the submarine gas hydrate research project (SUGAR) a large reservoir simulator (LARS) with an internal volume of 425 liter has been designed, built and tested. To our knowledge this is presently a word-wide unique set up. Because of its large volume it is suitable for pilot plant scale tests on hydrate behavior in sediments. That includes not only the option of systematic tests on gas hydrate formation in various sedimentary settings but also the possibility to mimic scenarios for the hydrate decomposition and subsequent natural gas extraction. Based on these experimental results various numerical simulations can be realized. Here, we present the design and the experimental set up of LARS. The prerequisites for the simulation of a natural gas hydrate reservoir are porous sediments, methane, water, low temperature and high pressure. The reservoir is supplied by methane-saturated and pre-cooled water. For its preparation an external gas-water mixing stage is available. The methane-loaded water is continuously flushed into LARS as finely dispersed fluid via bottom-and-top-located sparger. The LARS is equipped with a mantle cooling system and can be kept at a chosen set temperature. The temperature distribution is monitored at 14 reasonable locations throughout the reservoir by Pt100 sensors. Pressure needs are realized using syringe pump stands. A tomographic system, consisting of a 375-electrode-configuration is attached to the mantle for the monitoring of hydrate distribution throughout the entire reservoir volume. Two sets of tubular polydimethylsiloxan-membranes are applied to determine gas-water ratio within the reservoir using the effect of permeability

  5. Octreotide LAR and Prednisone as Neoadjuvant Treatment in Patients with Primary or Locally Recurrent Unresectable Thymic Tumors: A Phase II Study

    PubMed Central

    Kirzinger, Lukas; Boy, Sandra; Marienhagen, Jörg; Schuierer, Gerhard; Neu, Reiner; Ried, Michael; Hofmann, Hans-Stefan; Wiebe, Karsten; Ströbel, Philipp; May, Christoph; Kleylein-Sohn, Julia; Baierlein, Claudia; Bogdahn, Ulrich; Marx, Alexander; Schalke, Berthold

    2016-01-01

    Therapeutic options to cure advanced, recurrent, and unresectable thymomas are limited. The most important factor for long-term survival of thymoma patients is complete resection (R0) of the tumor. We therefore evaluated the response to and the induction of resectability of primarily or locally recurrent unresectable thymomas and thymic carcinomas by octreotide Long-Acting Release (LAR) plus prednisone therapy in patients with positive octreotide scans. In this open label, single-arm phase II study, 17 patients with thymomas considered unresectable or locally recurrent thymoma (n = 15) and thymic carcinoma (n = 2) at Masaoka stage III were enrolled. Octreotide LAR (30 mg once every 2 weeks) was administered in combination with prednisone (0.6 mg/kg per day) for a maximum of 24 weeks (study design according to Fleming´s one sample multiple testing procedure for phase II clinical trials). Tumor size was evaluated by volumetric CT measurements, and a decrease in tumor volume of at least 20% at week 12 compared to baseline was considered as a response. We found that octreotide LAR plus prednisone elicited response in 15 of 17 patients (88%). Median reduction of tumor volume after 12 weeks of treatment was 51% (range 20%–86%). Subsequently, complete surgical resection was achieved in five (29%) and four patients (23%) after 12 and 24 weeks, respectively. Octreotide LAR plus prednisone treatment was discontinued in two patients before week 12 due to unsatisfactory therapeutic effects or adverse events. The most frequent adverse events were gastrointestinal (71%), infectious (65%), and hematological (41%) complications. In conclusion, octreotide LAR plus prednisone is efficacious in patients with primary or recurrent unresectable thymoma with respect to tumor regression. Octreotide LAR plus prednisone was well tolerated and adverse events were in line with the known safety profile of both agents. PMID:27992479

  6. Long-term operation of a double phase LAr LEM Time Projection Chamber with a simplified anode and extraction-grid design

    NASA Astrophysics Data System (ADS)

    Cantini, C.; Epprecht, L.; Gendotti, A.; Horikawa, S.; Murphy, S.; Natterer, G.; Periale, L.; Resnati, F.; Rubbia, A.; Sergiampietri, F.; Viant, T.; Wu, S.

    2014-03-01

    We report on the successful operation of a double phase Liquid Argon Large Electron Multiplier Time Projection Chamber (LAr LEM-TPC) equipped with two dimensional projective anodes with dimensions 10 × 10 cm2, and with a maximum drift length of 21 cm. The anodes were manufactured for the first time from a single multilayer printed circuit board (PCB). Various layouts of the readout views have been tested and optimised. In addition, the ionisation charge was efficiently extracted from the liquid to the gas phase with a single grid instead of two previously. We studied the response and the gain of the detector to cosmic muon tracks. To study long-term stability over several weeks, we continuously operated the chamber at fixed electric field settings. We reproducibly observe that after an initial decrease with a characteristic time of τ ≈ 1.6 days, the observed gain is stable. In 46 days of operation, a total of 14.6 million triggers have been collected at a stable effective gain of G∞ ~ 15 corresponding to a signal-to-noise ratio (S/N)gtrsim60 for minimum ionising tracks. During the full period, eight discharges across the LEM were observed. A maximum effective gain of 90 was also observed, corresponding to a signal-to-noise ratio (S/N)gtrsim400 for minimum ionising tracks, or S/N ≈ 10 for an energy deposition of 15 keV on a single readout channel.

  7. First operation and performance of a 200 lt double phase LAr LEM-TPC with a 40 × 76 cm2 readout

    NASA Astrophysics Data System (ADS)

    Badertscher, A.; Curioni, A.; Degunda, U.; Epprecht, L.; Gendotti, A.; Horikawa, S.; Knecht, L.; Lussi, D.; Natterer, G.; Nguyen, K.; Resnati, F.; Rubbia, A.; Viant, T.

    2013-04-01

    In this paper we describe the design, construction, and operation of a first large area double-phase liquid argon Large Electron Multiplier Time Projection Chamber (LAr LEM-TPC). The detector has a maximum drift length of 60 cm and the readout consists of a 40 × 76 cm2 LEM and 2D projective anode to multiply and collect drifting charges. Scintillation light is detected by means of cryogenic PMTs positioned below the cathode. To record both charge and light signals, we have developed a compact acquisition system, which is scalable up to ton-scale detectors with thousands of charge readout channels. The acquisition system, as well as the design and the performance of custom-made charge sensitive preamplifiers, are described. The complete experimental setup has been operated for a first time during a period of four weeks at CERN in the cryostat of the ArDM experiment, which was equipped with liquid and gas argon purification systems. The detector, exposed to cosmic rays, recorded events with a single-channel signal-to-noise ratio in excess of 30 for minimum ionising particles. Cosmic muon tracks and their δ-rays were used to assess the performance of the detector, and to estimate the liquid argon purity and the gain at different amplification fields.

  8. Postcrystallization metasomatism in shergottites: Evidence from the paired meteorites LAR 06319 and LAR 12011

    NASA Astrophysics Data System (ADS)

    Howarth, Geoffrey H.; Liu, Yang; Chen, Yang; Pernet-Fisher, John F.; Taylor, Lawrence A.

    2016-11-01

    Apatite is the major volatile-bearing phase in Martian meteorites, containing structurally bound fluorine, chlorine, and hydroxyl ions. In apatite, F is more compatible than Cl, which in turn is more compatible than OH. During degassing, Cl strongly partitions into the exsolved phase, whereas F remains in the melt. For these reasons, the volatile concentrations within apatite are predictable during magmatic differentiation and degassing. Here, we present compositional data for apatite and merrillite in the paired enriched, olivine-phyric shergottites LAR 12011 and LAR 06319. In addition, we calculate the relative volatile fugacities of the parental melts at the time of apatite formation. The apatites are dominantly OH-rich (calculated by stoichiometry) with variable yet high Cl contents. Although several other studies have found evidence for degassing in the late-stage mineral assemblage of LAR 06319, the apatite evolutionary trends cannot be reconciled with this interpretation. The variable Cl contents and high OH contents measured in apatites are not consistent with fractionation either. Volatile fugacity calculations indicate that water and fluorine activities remain relatively constant, whereas there is a large variation in the chlorine activity. The Martian crust is Cl-rich indicating that changes in Cl contents in the apatites may be related to an external crustal source. We suggest that the high and variable Cl contents and high OH contents of the apatite are the results of postcrystallization interaction with Cl-rich, and possibly water-rich, crustal fluids circulating in the Martian crust.

  9. Lar gibbon (Hylobates lar) great call reveals individual caller identity.

    PubMed

    Terleph, Thomas A; Malaivijitnond, S; Reichard, U H

    2015-07-01

    Gibbons (family Hylobatidae) produce loud, elaborate vocalizations (songs), often in well-coordinated male/female duets. The female's great call, the most conspicuous phrase of the gibbon vocal repertoire, functions primarily to mediate territorial defense. Despite the fact that lar gibbons (Hylobates lar) are the most widely distributed and well researched hylobatid species and produce a rich vocal repertoire, the individual-specificity of their great calls has not previously been quantified. In addition, spectral and temporal features of notes occurring at specific locations within the lar great call have not been described. Here we provide such a description, and test the hypothesis that great calls are statistically discriminable between a large sample of individual callers. We compared recordings of great calls from 14 wild lar females in Khao Yai National Park, Thailand. Our analyses of principal components derived from spectral and temporal measures, as well as spectrograms from the entire great call, indicate that acoustic variation is sufficient to allow identification of individual callers (83.5% discriminability based on principal components, and inter-individual call variation exceeding intra-individual variation in overall spectrogram). These vocalizations potentially allow individual recognition of animals.

  10. Large phased-array radars

    SciTech Connect

    Brookner, D.E.

    1988-12-15

    Large phased-array radars can play a very important part in arms control. They can be used to determine the number of RVs being deployed, the type of targeting of the RVs (the same or different targets), the shape of the deployed objects, and possibly the weight and yields of the deployed RVs. They can provide this information at night as well as during the day and during rain and cloud covered conditions. The radar can be on the ground, on a ship, in an airplane, or space-borne. Airborne and space-borne radars can provide high resolution map images of the ground for reconnaissance, of anti-ballistic missile (ABM) ground radar installations, missile launch sites, and tactical targets such as trucks and tanks. The large ground based radars can have microwave carrier frequencies or be at HF (high frequency). For a ground-based HF radar the signal is reflected off the ionosphere so as to provide over-the-horizon (OTH) viewing of targets. OTH radars can potentially be used to monitor stealth targets and missile traffic.

  11. Lars, the Oracle

    NASA Astrophysics Data System (ADS)

    Careri, Giorgio

    Lars Onsager was known for his obscure but correct predictions in several fields of science. Some scientific events, particularly in the field of superfluidity, are recollected here by one of his old friends.

  12. Large-scale nanophotonic phased array.

    PubMed

    Sun, Jie; Timurdogan, Erman; Yaacobi, Ami; Hosseini, Ehsan Shah; Watts, Michael R

    2013-01-10

    Electromagnetic phased arrays at radio frequencies are well known and have enabled applications ranging from communications to radar, broadcasting and astronomy. The ability to generate arbitrary radiation patterns with large-scale phased arrays has long been pursued. Although it is extremely expensive and cumbersome to deploy large-scale radiofrequency phased arrays, optical phased arrays have a unique advantage in that the much shorter optical wavelength holds promise for large-scale integration. However, the short optical wavelength also imposes stringent requirements on fabrication. As a consequence, although optical phased arrays have been studied with various platforms and recently with chip-scale nanophotonics, all of the demonstrations so far are restricted to one-dimensional or small-scale two-dimensional arrays. Here we report the demonstration of a large-scale two-dimensional nanophotonic phased array (NPA), in which 64 × 64 (4,096) optical nanoantennas are densely integrated on a silicon chip within a footprint of 576 μm × 576 μm with all of the nanoantennas precisely balanced in power and aligned in phase to generate a designed, sophisticated radiation pattern in the far field. We also show that active phase tunability can be realized in the proposed NPA by demonstrating dynamic beam steering and shaping with an 8 × 8 array. This work demonstrates that a robust design, together with state-of-the-art complementary metal-oxide-semiconductor technology, allows large-scale NPAs to be implemented on compact and inexpensive nanophotonic chips. In turn, this enables arbitrary radiation pattern generation using NPAs and therefore extends the functionalities of phased arrays beyond conventional beam focusing and steering, opening up possibilities for large-scale deployment in applications such as communication, laser detection and ranging, three-dimensional holography and biomedical sciences, to name just a few.

  13. GMRT HI Imaging of Selected LARS+eLARS Galaxies

    NASA Astrophysics Data System (ADS)

    Perez Sarmiento, Karen; Mendoza Davila, Cesar I.; Cannon, John M.; Hayes, Matthew; Melinder, Jens; Östlin, Göran; Pardy, Stephen; LARS Team

    2017-01-01

    The Lyman Alpha Reference Sample (LARS) and its extension (eLARS) form the most comprehensive effort to date to study the details of Lyman Alpha radiative transfer in galaxies. Direct imaging of Lyman Alpha emission from the Hubble Space Telescope is supplemented by a wealth of multi-wavelength observations designed to probe the complex processes that contribute to the escape or destruction of Lyman Alpha photons as they resonantly scatter in the neutral ISM. The 42 LARS+eLARS galaxies span a range of physical properties, including mass and star formation rate. In this work, we present new GMRT HI imaging of selected LARS+eLARS galaxies designed to study the detailed morphology and kinematics of the HI gas. HI column density images and velocity fields are compared to SDSS imaging.

  14. Rationale and protocol of the MetNET-1 trial, a prospective, single center, phase II study to evaluate the activity and safety of everolimus in combination with octreotide LAR and metformin in patients with advanced pancreatic neuroendocrine tumors.

    PubMed

    Pusceddu, Sara; de Braud, Filippo; Concas, Laura; Bregant, Cristina; Leuzzi, Livia; Formisano, Barbara; Buzzoni, Roberto

    2014-01-01

    Abnormal PI3K-AKT-mTOR pathway signalling and autocrine activation of the mTOR pathway, mediated through insulin-like growth factor-1, have been implicated in the proliferation of pancreatic neuroendocrine tumor (pNET) cells. Everolimus, an mTOR inhibitor, has shown antitumor benefit in pNETs alone and in combination with octreotide LAR in RADIANT-1 and RADIANT-3 studies. Although everolimus-based phase II/III trials have improved progression-free survival for pNET, its use has not impacted on prolonging overall survival. Metformin has recently shown some anti-cancer activity in both in vitro and in vivo studies by its indirect properties to decrease insulin and insulin-like growth factor-1 (IGF-1) levels and by its antitumour effect to promote AMPK activation and consequently inhibition to TSC1-2/mTOR complex. In light of even more retrospective evidence of metformin's anticancer activity, a prospective evaluation is required to either confirm or discard these preliminary findings. With the aim to evaluate the antiproliferative effect of metformin in combination with everolimus and octreotide LAR in pancreatic well-differentiated neuroendocrine tumor patients, a single arm, prospective, single center phase II study was designed (MetNET-1 trial, NCT 02294006). Forty-three patients are expected to be evaluated. The study is ongoing, and recruitment is estimated to be completed in August 2016. The results will be anticipated in 2017.

  15. Photorefractive processing for large adaptive phased arrays

    NASA Astrophysics Data System (ADS)

    Weverka, Robert T.; Wagner, Kelvin; Sarto, Anthony

    1996-03-01

    An adaptive null-steering phased-array optical processor that utilizes a photorefractive crystal to time integrate the adaptive weights and null out correlated jammers is described. This is a beam-steering processor in which the temporal waveform of the desired signal is known but the look direction is not. The processor computes the angle(s) of arrival of the desired signal and steers the array to look in that direction while rotating the nulls of the antenna pattern toward any narrow-band jammers that may be present. We have experimentally demonstrated a simplified version of this adaptive phased-array-radar processor that nulls out the narrow-band jammers by using feedback-correlation detection. In this processor it is assumed that we know a priori only that the signal is broadband and the jammers are narrow band. These are examples of a class of optical processors that use the angular selectivity of volume holograms to form the nulls and look directions in an adaptive phased-array-radar pattern and thereby to harness the computational abilities of three-dimensional parallelism in the volume of photorefractive crystals. The development of this processing in volume holographic system has led to a new algorithm for phased-array-radar processing that uses fewer tapped-delay lines than does the classic time-domain beam former. The optical implementation of the new algorithm has the further advantage of utilization of a single photorefractive crystal to implement as many as a million adaptive weights, allowing the radar system to scale to large size with no increase in processing hardware.

  16. Large phase-by-phase modulations in atomic interfaces.

    PubMed

    Artoni, M; Zavatta, A

    2015-09-11

    Phase-resonant closed-loop optical transitions can be engineered to achieve broadly tunable light phase shifts. Such a novel phase-by-phase control mechanism does not require a cavity and is illustrated here for an atomic interface where a classical light pulse undergoes radian level phase modulations all-optically controllable over a few micron scale. It works even at low intensities and hence may be relevant to new applications of all-optical weak-light signal processing.

  17. Integrated plan for LArTPC neutrino detectors in the US

    SciTech Connect

    Baller, B.; Fleming, B.; /Fermilab

    2009-11-01

    We present an integrated R&D plan aimed at demonstrating the ability to build a very large Liquid Argon Time Projection Chamber (LArTPC), on a scale suitable for use as a Far Detector for the LBNE neutrino oscillation experiment. This plan adopts current LArTPC R&D-related activities and proposes new ones to address questions that go beyond those being answered by the current efforts. We have employed a risk evaluation strategy to identify questions that can be answered (or risks that can be mitigated) through one or more R&D steps. In summary form, the plan consists of the following pre-existing components: (1) The Materials Test Stand program, now in operation at Fermilab, addressing questions pertaining to maintenance of argon purity; (2) Existing electronics test stands at FNAL and BNL; (3) The Liquid Argon Purity Demonstrator (LAPD) now being assembled at Fermilab; (4) The ArgoNeuT prototype LArTPC, now running in the NuMI beam; (5) The MicroBooNE experiment, proposed as a physics experiment that will advance our understanding of the LArTPC technology, now completing its conceptual design phase; (6) A software development effort that is well integrated across present and planned LArTPC detectors. We are proposing to add to these efforts the following: (1) A membrane cryostat mechanical prototype to evaluate and gain expertise with this technology; (2) An installation and integration prototype, to understand issues pertaining to detector assembly, particularly in an underground environment; (3) A {approx} 5% scale electronics systems test to understand system-wide issues as well as individual component reliability. (4) A calibration test stand that would consist of a small TPC to be exposed to a test beam for calibration studies, relevant for evaluation of physics sensitivities. We have developed a timeline and milestones for achieving these goals as discussed in Section 4. The proposed activities necessary for the final design of LAr20 are complete by CD3 in

  18. A Direct Comparison of HI and Lyα Morphologies in Two LARS Galaxies

    NASA Astrophysics Data System (ADS)

    Fitzgibbon, Kathleen; Cannon, John M.; Freeland, Emily; Hayes, Matthew; Östlin, Göran; LARS Team

    2016-01-01

    The Lyman-Alpha Reference Sample (LARS) and its extension (eLARS) represent an exhaustive campaign to reverse-engineer galaxies. The main goal is to understand how Lyα is transported within galaxies: what fraction of it escapes, and what physical properties affect Lyα morphology and radiative transport (e.g. dust and gas content, metallicity, kinematics, properties of the stellar population). Neutral hydrogen emission, which can be used to determine a galaxy's structure and kinematics, was observed using the B and C configurations of the Very Large Array in two galaxies from the sample: LARS02 and LARS09. Images of the HI mass surface density and of the intensity weighted HI velocity field were created at angular scales of ~8 arcseconds. Extended HI gas is detected at high significance up to ˜30 kpc from the optical body of LARS02. LARS09 has a severely disturbed optical morphology; our new HI observations reveal that LARS09 is interacting with the nearby field galaxy SDSS J082353.65+280622.2. In combination with direct imaging of the Lyα morphology from the Hubble Space Telescope, this program has produced the first direct comparison of Lyα and HI morphologies. These observations demonstrate concept for a significant observational campaign that will produce similar comparisons in the remaining 40 LARS+eLARS galaxies.KF was partially supported by a Science Education Award from the Howard Hughes Medical Institute (HHMI) to Macalester College.

  19. Lars Onsager Prize Talk: 1+1d conformal field theories as natural languages for asymptotically large-scale quantum computing

    NASA Astrophysics Data System (ADS)

    Friedan, Daniel

    2010-03-01

    An abstract argument is offered that the ideal physical systems for asymptotically large-scale quantum computers are near-critical quantum circuits, critical in the bulk, whose bulk universality classes are described by 1+1d conformal field theories. One in particular -- the Monster conformal field theory -- is especially ideal, because all of its bulk couplings are irrelevant.

  20. Research and development for a free-running readout system for the ATLAS LAr Calorimeters at the high luminosity LHC

    NASA Astrophysics Data System (ADS)

    Hils, Maximilian

    2016-07-01

    The ATLAS Liquid Argon (LAr) Calorimeters were designed and built to measure electromagnetic and hadronic energy in proton-proton collisions produced at the Large Hadron Collider (LHC) at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 1034 cm-2 s-1. The High Luminosity LHC (HL-LHC) programme is now developed for up to 5-7 times the design luminosity, with the goal of accumulating an integrated luminosity of 3000 fb-1. In the HL-LHC phase, the increased radiation levels and an improved ATLAS trigger system require a replacement of the Front-end (FE) and Back-end (BE) electronics of the LAr Calorimeters. Results from research and development of individual components and their radiation qualification as well as the overall system design will be presented.

  1. Towards large-Chern-number topological phases by periodic quenching

    NASA Astrophysics Data System (ADS)

    Xiong, Tian-Shi; Gong, Jiangbin; An, Jun-Hong

    2016-05-01

    Topological phases with large Chern numbers have important implications. They were previously predicted to exist by considering fabricated long-range interactions or multilayered materials. Stimulated by recent wide interests in Floquet topological phases, here we propose a scheme to engineer large-Chern-number phases with ease by periodic quenching. Using a two-band system as an example, we theoretically show how a variety of topological phases with widely tunable Chern numbers can be generated by periodic quenching between two simple Hamiltonians that otherwise give low Chern numbers. The obtained large Chern numbers are explained through the emergence of multiple Dirac cones in the Floquet spectra. The transition lines between different topological phases in the two-band model are also explicitly found, thus establishing a class of easily solvable but very rich systems useful for further understandings and applications of topological phases in periodically driven systems.

  2. EXTREMELY LARGE EUV LATE PHASE OF SOLAR FLARES

    SciTech Connect

    Liu, Kai; Wang, Yuming; Liu, Rui; Shen, Chenglong; Zhang, Jie; Cheng, Xin

    2015-03-20

    The second peak in the Fe xvi 33.5 nm line irradiance observed during solar flares by the Extreme-Ultraviolet Variability Experiment (EVE) is known as the EUV late phase. Our previous paper in 2013 by Liu et al. found that the main emissions in the late phase are originated from large-scale loop arcades that are closely connected to but different from the post-flare loops (PFLs), and we also proposed that a long cooling process without additional heating could explain the late phase. In this paper, we define the extremely large late phase because it not only has a bigger peak in the warm 33.5 irradiance profile, but also releases more EUV radiative energy than the main phase. Through detailed inspection of the EUV images from three points of view, it was discovered that aside from the later-phase loop arcades, the main contributor of the extremely large late phase is a hot structure that fails to erupt. This hot structure is identified as a flux rope, which is quickly energized by the flare reconnection and later on continuously produces the thermal energy during the gradual phase. Together with the late-phase loop arcades, the flux rope failing to erupt with the additional heating create the extremely large EUV late phase.

  3. Extremely Large EUV Late Phase of Solar Flares

    NASA Astrophysics Data System (ADS)

    Liu, Kai; Wang, Yuming; Zhang, Jie; Cheng, Xin; Liu, Rui; Shen, Chenglong

    2015-04-01

    The second peak in the Fe XVI 33.5 nm line irradiance observed during solar flares by Extreme ultraviolet Variability Experiment (EVE) is known as Extreme UltraViolet (EUV) late phase. Our previous paper found that the main emissions in the late phase are originated from large-scale loop arcades that are closely connected to but different from the post flare loops (PFLs), and we also proposed that a long cooling process without additional heating could explain the late phase. In this paper, we define the extremely large late phase because it not only has a bigger peak in the warm 33.5 irradiance profile, but also releases more EUV radiative energy than the main phase. Through detailedly inspecting the EUV images from three point-of-view, it is found that, besides the later phase loop arcades, the more contribution of the extremely large late phase is from a hot structure that fails to erupt. This hot structure is identified as a flux rope, which is quickly energized by the flare reconnection and later on continuously produces the thermal energy during the gradual phase. Together with the late-phase loop arcades, the fail to erupt flux rope with the additional heating creates the extremely large EUV late phase.

  4. Extremely Large EUV Late Phase of Solar Flares

    NASA Astrophysics Data System (ADS)

    Liu, Kai; Wang, Yuming; Zhang, Jie; Cheng, Xin; Liu, Rui; Shen, Chenglong

    2015-03-01

    The second peak in the Fe xvi 33.5 nm line irradiance observed during solar flares by the Extreme-Ultraviolet Variability Experiment (EVE) is known as the EUV late phase. Our previous paper in 2013 by Liu et al. found that the main emissions in the late phase are originated from large-scale loop arcades that are closely connected to but different from the post-flare loops (PFLs), and we also proposed that a long cooling process without additional heating could explain the late phase. In this paper, we define the extremely large late phase because it not only has a bigger peak in the warm 33.5 irradiance profile, but also releases more EUV radiative energy than the main phase. Through detailed inspection of the EUV images from three points of view, it was discovered that aside from the later-phase loop arcades, the main contributor of the extremely large late phase is a hot structure that fails to erupt. This hot structure is identified as a flux rope, which is quickly energized by the flare reconnection and later on continuously produces the thermal energy during the gradual phase. Together with the late-phase loop arcades, the flux rope failing to erupt with the additional heating create the extremely large EUV late phase.

  5. VLA HI Imaging of the LARS+eLARS Galaxies: Global HI Properties

    NASA Astrophysics Data System (ADS)

    Eisner, Brian Andrew; Reilly, Bridget; Cannon, John M.; Hayes, Matthew; Melinder, Jens; Östlin, Göran; Pardy, Stephen; LARS Team

    2017-01-01

    The Lyman Alpha Reference Sample (LARS) and its extension (eLARS) form the most comprehensive effort to date to study the details of Lyman Alpha radiative transfer in galaxies. Direct imaging of Lyman Alpha emission from the Hubble Space Telescope is supplemented by a wealth of multi-wavelength observations designed to probe the complex processes that contribute to the escape or destruction of Lyman Alpha photons as they resonantly scatter in the neutral ISM. The 42 LARS+eLARS galaxies span a range of physical properties, including mass and star formation rate. In this work, we present new VLA D-configuration HI imaging of 32 LARS+eLARS galaxies designed to localize the HI gas and to measure the total HI mass. HI column density images and velocity fields are compared to SDSS imaging. Most galaxies are unresolved at this angular resolution; a companion poster presents imaging of interacting galaxies that are well-resolved.

  6. Large conditional single-photon cross-phase modulation

    PubMed Central

    Hosseini, Mahdi; Duan, Yiheng; Vuletić, Vladan

    2016-01-01

    Deterministic optical quantum logic requires a nonlinear quantum process that alters the phase of a quantum optical state by π through interaction with only one photon. Here, we demonstrate a large conditional cross-phase modulation between a signal field, stored inside an atomic quantum memory, and a control photon that traverses a high-finesse optical cavity containing the atomic memory. This approach avoids fundamental limitations associated with multimode effects for traveling optical photons. We measure a conditional cross-phase shift of π/6 (and up to π/3 by postselection on photons that remain in the system longer than average) between the retrieved signal and control photons, and confirm deterministic entanglement between the signal and control modes by extracting a positive concurrence. By upgrading to a state-of-the-art cavity, our system can reach a coherent phase shift of π at low loss, enabling deterministic and universal photonic quantum logic. PMID:27519798

  7. Preliminary test results of LAr prototype detector

    NASA Astrophysics Data System (ADS)

    Li, Pei-Xian; Guan, Meng-Yun; Yang, Chang-Gen; Zhang, Peng; Liu, Jin-Chang; Zhang, Yong-Peng; Guo, Cong; Wang, Yi

    2016-11-01

    Liquid argon (LAr) is an attractive target for the direct detection of WIMPs. A LAr prototype detector was designed to study the technology and properties of LAr detectors. The prototype detector had an active volume containing 0.65 kg of liquid argon. A liquid nitrogen (LN) cooling system allowed the temperature fluctuation of the liquid argon to be controlled within less than 0.1 K during a one month run. In the 22Na calibration run, the LAr prototype obtained 1.59±0.02 p.e./keV light yield for 511 keV gamma rays using a domestic-made argon purification system. Supported by China Ministry of Science and Technology (2010CB833003), National Nature Science Foundation of China, Youth Science Found (11305188)

  8. Weak-signal Phase Calibration Strategies for Large DSN Arrays

    NASA Technical Reports Server (NTRS)

    Jones, Dayton L.

    2005-01-01

    The NASA Deep Space Network (DSN) is studying arrays of large numbers of small, mass-produced radio antennas as a cost-effective way to increase downlink sensitivity and data rates for future missions. An important issue for the operation of large arrays is the accuracy with which signals from hundreds of small antennas can be combined. This is particularly true at Ka band (32 GHz) where atmospheric phase variations can be large and rapidly changing. A number of algorithms exist to correct the phases of signals from individual antennas in the case where a spacecraft signal provides a useful signal-to-noise ratio (SNR) on time scales shorter than the atmospheric coherence time. However, for very weak spacecraft signals it will be necessary to rely on background natural radio sources to maintain array phasing. Very weak signals could result from a spacecraft emergency or by design, such as direct-to-Earth data transmissions from distant planetary atmospheric or surface probes using only low gain antennas. This paper considers the parameter space where external real-time phase calibration will be necessary, and what this requires in terms of array configuration and signal processing. The inherent limitations of this technique are also discussed.

  9. Phase transitions in large deviations of reset processes

    NASA Astrophysics Data System (ADS)

    Harris, Rosemary J.; Touchette, Hugo

    2017-03-01

    We study the large deviations of additive quantities, such as energy or current, in stochastic processes with intermittent reset. Via a mapping from a discrete-time reset process to the Poland–Scheraga model for DNA denaturation, we derive conditions for observing first-order or continuous dynamical phase transitions in the fluctuations of such quantities and confirm these conditions on simple random walk examples. These results apply to reset Markov processes, but also show more generally that subleading terms in generating functions can lead to non-analyticities in large deviation functions of ‘compound processes’ or ‘random evolutions’ switching stochastically between two or more subprocesses.

  10. Large Phased Array Radar Using Networked Small Parabolic Reflectors

    NASA Technical Reports Server (NTRS)

    Amoozegar, Farid

    2006-01-01

    Multifunction phased array systems with radar, telecom, and imaging applications have already been established for flat plate phased arrays of dipoles, or waveguides. In this paper the design trades and candidate options for combining the radar and telecom functions of the Deep Space Network (DSN) into a single large transmit array of small parabolic reflectors will be discussed. In particular the effect of combing the radar and telecom functions on the sizes of individual antenna apertures and the corresponding spacing between the antenna elements of the array will be analyzed. A heterogeneous architecture for the DSN large transmit array is proposed to meet the radar and telecom requirements while considering the budget, scheduling, and strategic planning constrains.

  11. Large Area Crop Inventory Experiment (LACIE). Phase 2 evaluation report

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Documentation of the activities of the Large Area Crop Inventory Experiment during the 1976 Northern Hemisphere crop year is presented. A brief overview of the experiment is included as well as phase two area, yield, and production estimates for the United States Great Plains, Canada, and the Union of Soviet Socialist Republics spring winter wheat regions. The accuracies of these estimates are compared with independent government estimates. Accuracy assessment of the United States Great Plains yardstick region based on a through blind sight analysis is given, and reasons for variations in estimating performance are discussed. Other phase two technical activities including operations, exploratory analysis, reporting, methods of assessment, phase three and advanced system design, technical issues, and developmental activities are also included.

  12. Large phase shift via polarization-coupling cascading.

    PubMed

    Huo, Juan; Chen, Xianfeng

    2012-06-04

    Herein, we propose a phenomenon of "polarization-coupling (PC) cascading" generated in MgO doped periodically poled lithium niobate crystal (PPMgLN). PC cascading contributes to the effective electro-optical (EO) Kerr effect that is several orders of magnitude stronger than the classical ones. Experiment of Newton's rings demonstrates the large phase accumulation during the PC cascaded processes, and the experimental data is identical with the theoretical simulation.

  13. Nonlocal nonlinear refraction in Hibiscus sabdariffa with large phase shifts.

    PubMed

    Ramírez-Martínez, D; Alvarado-Méndez, E; Trejo-Durán, M; Vázquez-Guevara, M A

    2014-10-20

    In this work we present a study of nonlinear optical properties in organic materials (hibiscus sabdariffa). Our results demonstrate that the medium exhibits a highly nonlocal nonlinear response. We show preliminary numerical results of the transmittance as nonlocal response by considering, simultaneously, the nonlinear absorption and refraction in media. Numerical results are accord to measurement obtained by Z- scan technique where we observe large phase shifts. We also analyze the far field diffraction ring patterns of the sample.

  14. Large resistivity modulation in mixed-phase metallic systems

    NASA Astrophysics Data System (ADS)

    Lee, Yeonbae; Liu, Z. Q.; Heron, J. T.; Clarkson, J. D.; Hong, J.; Ko, C.; Biegalski, M. D.; Aschauer, U.; Hsu, S. L.; Nowakowski, M. E.; Wu, J.; Christen, H. M.; Salahuddin, S.; Bokor, J. B.; Spaldin, N. A.; Schlom, D. G.; Ramesh, R.

    2015-01-01

    In numerous systems, giant physical responses have been discovered when two phases coexist; for example, near a phase transition. An intermetallic FeRh system undergoes a first-order antiferromagnetic to ferromagnetic transition above room temperature and shows two-phase coexistence near the transition. Here we have investigated the effect of an electric field to FeRh/PMN-PT heterostructures and report 8% change in the electrical resistivity of FeRh films. Such a ‘giant’ electroresistance (GER) response is striking in metallic systems, in which external electric fields are screened, and thus only weakly influence the carrier concentrations and mobilities. We show that our FeRh films comprise coexisting ferromagnetic and antiferromagnetic phases with different resistivities and the origin of the GER effect is the strain-mediated change in their relative proportions. The observed behaviour is reminiscent of colossal magnetoresistance in perovskite manganites and illustrates the role of mixed-phase coexistence in achieving large changes in physical properties with low-energy external perturbation.

  15. Chandler wobble: two more large phase jumps revealed

    NASA Astrophysics Data System (ADS)

    Malkin, Zinovy; Miller, Natalia

    2010-12-01

    Investigations of the anomalies in the Earth rotation, in particular, the polar motion components, play an important role in our understanding of the processes that drive changes in the Earth's surface, interior, atmosphere, and ocean. This paper is primarily aimed at investigation of the Chandler wobble (CW) at the whole available 163-year interval to search for the major CW amplitude and phase variations. First, the CW signal was extracted from the IERS (International Earth Rotation and Reference Systems Service) Pole coordinates time series using two digital filters: the singular spectrum analysis and Fourier transform. The CW amplitude and phase variations were examined by means of the wavelet transform and Hilbert transform. Results of our analysis have shown that, besides the well-known CW phase jump in the 1920s, two other large phase jumps have been found in the 1850s and 2000s. As in the 1920s, these phase jumps occurred contemporarily with a sharp decrease in the CW amplitude.

  16. VLA HI Imaging of the LARS+eLARS Galaxies: Tidally Interacting Systems

    NASA Astrophysics Data System (ADS)

    Reilly, Bridget; Eisner, Brian Andrew; Cannon, John M.; Hayes, Matthew; Melinder, Jens; Östlin, Göran; Pardy, Stephen; LARS Team

    2017-01-01

    The Lyman Alpha Reference Sample (LARS) and its extension (eLARS) form the most comprehensive effort to date to study the details of Lyman Alpha radiative transfer in galaxies. Direct imaging of Lyman Alpha emission from the Hubble Space Telescope is supplemented by a wealth of multi-wavelength observations designed to probe the complex processes that contribute to the escape or destruction of Lyman Alpha photons as they resonantly scatter in the neutral ISM. The 42 LARS+eLARS galaxies span a range of physical properties, including mass and star formation rate. A companion poster presents VLA HI imaging of 32 LARS+eLARS galaxies. In this work, we present new VLA D-configuration HI imaging of selected LARS+eLARS galaxies that are well-resolved or tidally interacting. HI column density and velocity field images are compared to SDSS imaging. We interpret the results in the context of tidal interactions shifting the HI gas out of resonance and increasing the likelihood of Lyman Alpha photons escaping the galaxy.

  17. Search for space charge effects in the ICARUS T600 LAr-TPC

    NASA Astrophysics Data System (ADS)

    Torti, Marta

    2016-11-01

    Space charge in Liquid Argon Time Projection Chamber is due to the accumu- lation of positive ions, produced by ionizing tracks crossing the detector, which slowly flow toward the cathode. As a consequence, electric field distortions may arise, thus hindering the possibility to produce faithful 3D images of the ionizing events. The presence of space charge becomes relevant for large TPCs operating at surface or at shallow depths, where cosmic ray flux is high. These effects could interest the next phase of the ICARUS T600 detector, which will be deployed at shallow depths as a Far Detector for Short Baseline Neutrino experiment at FNAL dedicated to sterile neutrino searches. In 2001, the first ICARUS T600 module (T300) operated at surface in Pavia (Italy), recording cosmic ray data. In this work, a sample of cosmic muon tracks from the 2001 run was analyzed and results on space charge effects in LAr-TPCs are shown.

  18. Fluid Flow Patterns During Production from Gas Hydrates in the Laboratory compared to Field Settings: LARS vs. Mallik

    NASA Astrophysics Data System (ADS)

    Strauch, B.; Heeschen, K. U.; Priegnitz, M.; Abendroth, S.; Spangenberg, E.; Thaler, J.; Schicks, J. M.

    2015-12-01

    The GFZ's LArge Reservoir Simulator LARS allows for the simulation of the 2008 Mallik gas hydrate production test and the comparison of fluid flow patterns and their driving forces. Do we see the gas flow pattern described for Mallik [Uddin, M. et al., J. Can. Petrol Tech, 50, 70-89, 2011] in a pilot scale test? If so, what are the driving forces? LARS has a network of temperature sensors and an electric resistivity tomography (ERT) enabling a good spatial resolution of gas hydrate occurrences, water and gas distribution, and changes in temperature in the sample. A gas flow meter and a water trap record fluid flow patterns and a backpressure valve has controlled the depressurization equivalent to the three pressure stages (7.0 - 5.0 - 4.2 MPa) applied in the Mallik field test. The environmental temperature (284 K) and confining pressure (13 MPa) have been constant. The depressurization induced immediate endothermic gas hydrate dissociation until re-establishment of the stability conditions by a consequent temperature decrease. Slight gas hydrate dissociation continued at the top and upper lateral border due to the constant heat input from the environment. Here transport pathways were short and permeability higher due to lower gas hydrate saturation. At pressures of 7.0 and 5.0 MPa the LARS tests showed high water flow rates and short irregular spikes of gas production. The gas flow patterns at 4.2 MPa and 3.0MPa resembled those of the Mallik test. In LARS the initial gas surges overlap with times of hydrate instability while water content and lengths of pathways had increased. Water production was at a minimum. A rapidly formed continuous gas phase caused the initial gas surges and only after gas hydrate dissociation decreased to a minimum the single gas bubbles get trapped before slowly coalescing again. In LARS, where pathways were short and no additional water was added, a transport of microbubbles is unlikely to cause a gas surge as suggested for Mallik.

  19. Spatiotemporal Phase Synchronization in a Large Array of Convective Oscillators

    NASA Astrophysics Data System (ADS)

    Miranda, Montserrat A.; Burguete, Javier

    In a quasi-1D thermal convective system consisting of a large array of nonlinearly coupled oscillators, clustering is the way to achieve a regime of mostly antiphase synchronized oscillators. This regime is characterized by a spatiotemporal doubling of traveling modes. As the dynamics is explored beyond a spatiotemporal chaos regime with weak coupling, new interacting modes emerge through a supercritical bifurcation. In this new regime, the system exhibits coherent subsystems of antiphase synchronized oscillators, which are stationary clusters following a spatiotemporal beating phenomena. This regime is the result of a stronger coupling. We show from a phase mismatch model applied to each oscillator, that these phase coherent domains undergo a global phase instability meanwhile the interactions between oscillators become nonlocal. For each value of the control parameter we find out the time-varying topology (link matrix) from the contact interactions between oscillators. The new characteristic spatiotemporal scales are extracted from the antiphase correlations at the time intervals defined by the link matrix. The interpretation of these experimental results contributes to widen the understanding of other complex systems exhibiting similar phase chaotic dynamics in 2D and 3D.

  20. The LArIAT experiment at Fermilab

    SciTech Connect

    Nutini, Irene

    2016-03-01

    The LArIAT experiment at Fermilab is part of the International Neutrino program recently approved in the US. LArIAT aims to measure the main features of charged particles interactions in argon in the energy range (0.2 - 2.0 GeV) corresponding to the energy spectrum of the same particles when produced in a neutrino-argon interaction (neutrino energies of few GeV) typical of the short- and long-baseline neutrino beams of the Neutrino Program. Data collected from the 1st Run are being analyzed for both Physics studies and a technical characterization of the scintillation light collection system. Furthermore, two analysis topics are reported: the method developed for charged pion cross section measurement, based on the specific features of the LArTPC, and the development and test of the LArIAT custom-designed cold front-end electronics for SiPM devices to collect LAr scintillation light.

  1. The LArIAT experiment at Fermilab

    DOE PAGES

    Nutini, Irene

    2016-03-01

    The LArIAT experiment at Fermilab is part of the International Neutrino program recently approved in the US. LArIAT aims to measure the main features of charged particles interactions in argon in the energy range (0.2 - 2.0 GeV) corresponding to the energy spectrum of the same particles when produced in a neutrino-argon interaction (neutrino energies of few GeV) typical of the short- and long-baseline neutrino beams of the Neutrino Program. Data collected from the 1st Run are being analyzed for both Physics studies and a technical characterization of the scintillation light collection system. Furthermore, two analysis topics are reported: themore » method developed for charged pion cross section measurement, based on the specific features of the LArTPC, and the development and test of the LArIAT custom-designed cold front-end electronics for SiPM devices to collect LAr scintillation light.« less

  2. Large resistivity modulation in mixed-phase metallic systems

    NASA Astrophysics Data System (ADS)

    Lee, Yeonbae; Liu, Zhiqi; Heron, John; Clarkson, James; Hong, Jeongmin; Ko, Changhyun; Biegalski, Michael; Aschauer, Ulrich; Hsu, Shang-Lin; Nowakowski, Mark; Wu, Junqiao; Christen, Hans; Salahuddin, Sayeef; Bokor, Jeffrey; Spaldin, Nicola; Schlom, Darrell; Ramesh, Ramamoorthy

    2015-03-01

    We have investigated the effect of an electric field to FeRh/PMN-PT heterostructures and report 8% change in the electrical resistivity of FeRh films. Such a ``giant'' electroresistance (GER) response is striking in metallic systems, in which external electric fields are screened and thus only weakly influence the carrier concentrations and mobilities. We show that our FeRh films comprise coexisting ferromagnetic and antiferromagnetic phases with different resistivities, and the origin of the GER effect is the strain-mediated change in their relative proportions. The observed behavior is reminiscent of colossal magnetoresistance in perovskite manganites, and illustrates the role of mixed-phase coexistence in achieving large changes in physical properties with low-energy external perturbation.

  3. Large space telescope, phase A. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The Phase A study of the Large Space Telescope (LST) is reported. The study defines an LST concept based on the broad mission guidelines provided by the Office of Space Science (OSS), the scientific requirements developed by OSS with the scientific community, and an understanding of long range NASA planning current at the time the study was performed. The LST is an unmanned astronomical observatory facility, consisting of an optical telescope assembly (OTA), scientific instrument package (SIP), and a support systems module (SSM). The report consists of five volumes. The report describes the constraints and trade off analyses that were performed to arrive at a reference design for each system and for the overall LST configuration. A low cost design approach was followed in the Phase A study. This resulted in the use of standard spacecraft hardware, the provision for maintenance at the black box level, growth potential in systems designs, and the sharing of shuttle maintenance flights with other payloads.

  4. Three filters for visualization of phase objects with large variations of phase gradients

    SciTech Connect

    Sagan, Arkadiusz; Antosiewicz, Tomasz J.; Szoplik, Tomasz

    2009-02-20

    We propose three amplitude filters for visualization of phase objects. They interact with the spectra of pure-phase objects in the frequency plane and are based on tangent and error functions as well as antisymmetric combination of square roots. The error function is a normalized form of the Gaussian function. The antisymmetric square-root filter is composed of two square-root filters to widen its spatial frequency spectral range. Their advantage over other known amplitude frequency-domain filters, such as linear or square-root graded ones, is that they allow high-contrast visualization of objects with large variations of phase gradients.

  5. Large N phase transitions in massive N = 2 gauge theories

    SciTech Connect

    Russo, J. G.

    2014-07-23

    Using exact results obtained from localization on S{sup 4}, we explore the large N limit of N = 2 super Yang-Mills theories with massive matter multiplets. In this talk we discuss two cases: N = 2* theory, describing a massive hypermultiplet in the adjoint representation, and super QCD with massive quarks. When the radius of the four-sphere is sent to infinity these theories are described by solvable matrix models, which exhibit a number of interesting phenomena including quantum phase transitions at finite 't Hooft coupling.

  6. Optical phase curves of exoplanets at small and large phase angles

    NASA Astrophysics Data System (ADS)

    García Muñoz, Antonio

    2016-10-01

    Phase curves and secondary eclipses provide key information on exoplanet atmospheres. Indeed, recent work on close-in giant planets observed by Kepler has shown that it is possible to constrain various reflecting, dynamical and thermal properties of their atmospheres from the analysis of the planets' phase curves. This presentation discusses new diagnostic possibilities for the characterization of exoplanet atmospheres with optical phase curves. These possibilities benefit from the fact that at optical wavelengths the signal from the planet is either partly or mostly determined by scattering of starlight within its atmosphere, which entails that the structure of the planet's phase curve mimics to some extent the optical properties of the atmospheric medium. In particular, we will show how cloud properties such as the particle size or the atmospheric scale height might be constrained through observations at small (i.e. near transit) and large (i.e. near occultation) phase angles. We will emphasize how the interpretation of optical phase curves differs from the interpretation of phase curves obtained at longer wavelengths. The conclusions are relevant to the study of Kepler planets, but also to the investigation of phase curves to be delivered by upcoming space missions such as CHEOPS, JWST, PLATO and TESS.

  7. Using lanthanoid complexes to phase large macromolecular assemblies.

    PubMed

    Talon, Romain; Kahn, Richard; Durá, M Asunción; Maury, Olivier; Vellieux, Frédéric M D; Franzetti, Bruno; Girard, Eric

    2011-01-01

    Lanthanoid ions exhibit extremely large anomalous X-ray scattering at their L(III) absorption edge. They are thus well suited for anomalous diffraction experiments. A novel class of lanthanoid complexes has been developed that combines the physical properties of lanthanoid atoms with functional chemical groups that allow non-covalent binding to proteins. Two structures of large multimeric proteins have already been determined by using such complexes. Here the use of the luminescent europium tris-dipicolinate complex [Eu(DPA)(3)](3-) to solve the low-resolution structure of a 444 kDa homododecameric aminopeptidase, called PhTET1-12s from the archaea Pyrococcus horikoshii, is reported. Surprisingly, considering the low resolution of the data, the experimental electron density map is very well defined. Experimental phases obtained by using the lanthanoid complex lead to maps displaying particular structural features usually observed in higher-resolution maps. Such complexes open a new way for solving the structure of large molecular assemblies, even with low-resolution data.

  8. Large-Aperture Membrane Active Phased-Array Antennas

    NASA Technical Reports Server (NTRS)

    Karasik, Boris; McGrath, William; Leduc, Henry

    2009-01-01

    Large-aperture phased-array microwave antennas supported by membranes are being developed for use in spaceborne interferometric synthetic aperture radar systems. There may also be terrestrial uses for such antennas supported on stationary membranes, large balloons, and blimps. These antennas are expected to have areal mass densities of about 2 kg/sq m, satisfying a need for lightweight alternatives to conventional rigid phased-array antennas, which have typical areal mass densities between 8 and 15 kg/sq m. The differences in areal mass densities translate to substantial differences in total mass in contemplated applications involving aperture areas as large as 400 sq m. A membrane phased-array antenna includes patch antenna elements in a repeating pattern. All previously reported membrane antennas were passive antennas; this is the first active membrane antenna that includes transmitting/receiving (T/R) electronic circuits as integral parts. Other integral parts of the antenna include a network of radio-frequency (RF) feed lines (more specifically, a corporate feed network) and of bias and control lines, all in the form of flexible copper strip conductors on flexible polymeric membranes. Each unit cell of a prototype antenna (see Figure 1) contains a patch antenna element and a compact T/R module that is compatible with flexible membrane circuitry. There are two membrane layers separated by a 12.7-mm air gap. Each membrane layer is made from a commercially available flexible circuit material that, as supplied, comprises a 127-micron-thick polyimide dielectric layer clad on both sides with 17.5-micron-thick copper layers. The copper layers are patterned into RF, bias, and control conductors. The T/R module is located on the back side of the ground plane and is RF-coupled to the patch element via a slot. The T/R module is a hybrid multilayer module assembled and packaged independently and attached to the membrane array. At the time of reporting the information for

  9. Peology and Geochemistry of New Paired Martian Meteorites 12095 and LAR 12240

    NASA Technical Reports Server (NTRS)

    Funk, R. C.; Brandon, A. D.; Peslier, A.

    2015-01-01

    The meteorites LAR 12095 and LAR 12240 are believed to be paired Martian meteorites and were discovered during the Antarctic Search for Meteorites (ANSMET) 2012-2013 Season at Larkman Nunatak. The purpose of this study is to characterize these olivine-phyric shergottites by analyzing all mineral phases for major, minor and trace elements and examining their textural relationships. The goal is to constrain their crystallization history and place these shergottites among other Martian meteorites in order to better understand Martian geological history.

  10. Large magnetostriction from morphotropic phase boundary in ferromagnets.

    PubMed

    Yang, Sen; Bao, Huixin; Zhou, Chao; Wang, Yu; Ren, Xiaobing; Matsushita, Yoshitaka; Katsuya, Yoshio; Tanaka, Masahiko; Kobayashi, Keisuke; Song, Xiaoping; Gao, Jianrong

    2010-05-14

    For more than half of a century, morphotropic phase boundary (MPB) in ferroelectric materials has drawn constant interest because it can significantly enhance the piezoelectric properties. However, MPB has been studied merely in ferroelectric systems, not in another large class of ferroic systems, the ferromagnets. In this Letter, we report the existence of an MPB in a ferromagnetic system TbCo2-DyCo2. Such a magnetic MPB involves a first-order magnetoelastic transition, at which both magnetization direction and crystal structure change simultaneously. The MPB composition demonstrates a 3-6 times larger "figure of merit" of magnetostrictive response compared with that of the off-MPB compositions. The finding of MPB in ferromagnets may help to discover novel high-performance magnetostrictive and even magnetoelectric materials.

  11. Large area nuclear particle detectors using ET materials, phase 2

    NASA Technical Reports Server (NTRS)

    Wrigley, Charles Y.; Storti, George M.; Walter, Lee; Mathews, Scott

    1990-01-01

    This report presents work done under a Phase 2 SBIR contract for demonstrating large area detector planes utilizing Quantex electron trapping materials as a film medium for storing high-energy nuclide impingement information. The detector planes utilize energy dissipated by passage of the high-energy nuclides to produce localized populations of electrons stored in traps. Readout of the localized trapped electron populations is effected by scanning the ET plane with near-infrared, which frees the trapped electrons and results in optical emission at visible wavelengths. The effort involved both optimizing fabrication technology for the detector planes and developing a readout system capable of high spatial resolution for displaying the recorded nuclide passage tracks.

  12. Phased Array Mirror Extendible Large Aperture (PAMELA) Optics Adjustment

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Scientists at Marshall's Adaptive Optics Lab demonstrate the Wave Front Sensor alignment using the Phased Array Mirror Extendible Large Aperture (PAMELA) optics adjustment. The primary objective of the PAMELA project is to develop methods for aligning and controlling adaptive optics segmented mirror systems. These systems can be used to acquire or project light energy. The Next Generation Space Telescope is an example of an energy acquisition system that will employ segmented mirrors. Light projection systems can also be used for power beaming and orbital debris removal. All segmented optical systems must be adjusted to provide maximum performance. PAMELA is an on going project that NASA is utilizing to investigate various methods for maximizing system performance.

  13. Troll Phase 1, installation of large spools before pipelay

    SciTech Connect

    Buchan, S.; Kuhlmann, J.H.

    1996-12-01

    Development of the Troll Phase 1 project required landfall--towards a gas conditioning plant on the Norwegian west coast--of both 36-in. wet gas fed (or import) pipelines and 40-inch dry gas export pipelines. The very uneven seabed necessitated both the driving of a 3.5 km long subsea tunnel system and extensive route preparations. The lateral separation of 142 to 163 m between subsea tunnel pipeline risers and offshore pipeline laydown was bridged by fabricating four large--147 to 186 tons--spools. These spools were installed gas-filled in unique single lifts using special sea fastening and guidance systems. The odd-shaped 3-D spool configurations were fabricated to match an extensively prepared seabed. The spools were installed after tunnel pipeline riser completion but before pipeline laydown to minimize the duration of underwater activities late in the season. Special support structures were fabricated to support hyperbaric welding and pipeline laydown operations. Accurate pipeline laydown facilitated simple and quick lift, shift and alignment operations, and all (seven) automated hyperbaric welds with the Pipeline Repair Systems (PRS) were completed on schedule without the use of pup-pieces. Diver support during these activities constituted a significant operation in itself.

  14. LAr calorimeter for SCC with a common vacuum bulkhead---a concept to improve hermeticity

    SciTech Connect

    Pope, W.L. ); Watt, R.D. )

    1989-11-01

    A new concept for a Barrel/Endcap LAr Calorimeter (LAC) is described in which the Barrel and Endcaps are in separate vacuum enclosures but share a common vacuum bulkhead (CVB). We explore 2 possible bulkhead construction types; welded plate sandwich panels, and brazed sandwich panels in which the core is an isotropic cellular solid--foamed aluminum. Gas lines and electric cables from he innermost Drift Chamber pass through radial holes in the core of the sandwich bulkhead. The CVB concept offers the potential to obtain a more hermetic calorimeter with significantly reduced dead material and/or space in the interface region common to conventional design LAr detectors for the SSC with Endcap features. To utilize a common additional steps to remove the Drift Chamber, a large increase in Endcap standby heat leak, and perhaps, new cryogenic safety issues. We find that significant amount of dead mass can be removed from critical regions of the vacuum shells when compared to a promising SSC LAC reference design. It is also shown that the increased standby heat leak of this concept can be easily removed by existing cooling capacity in another large LAr calorimeter. It is further shown that shut-downs need not be appreciably longer. Finally, it is argued that cryogen spill hazards can be avoided if the Endcap's LAr is removed during Drift chamber maintenance shutdowns, and that cryogenic safety is not compromised.

  15. Ku band phased array in a large angular sector

    NASA Astrophysics Data System (ADS)

    Dubost, G.; Gueho, S.; Beguin, D.

    The feasibility of a microstrip, flat, phased, square array performing at high frequency and exhibiting proper technological behavior is demonstrated. A total of 64 three-bit digital PIN diode phase shifters are used to steer the beam. Sum and difference patterns can be formed for every deflected directivity. Data are presented on the efficiency evaluation for different deflection angles, the highest sidelobe levels, the maximum directivity, and the measured average efficiency.

  16. Phase field approach to martensitic phase transformations with large strains and interface stresses

    NASA Astrophysics Data System (ADS)

    Levitas, Valery I.

    2014-10-01

    Thermodynamically consistent phase field theory for multivariant martensitic transformations, which includes large strains and interface stresses, is developed. Theory is formulated in a way that some geometrically nonlinear terms do not disappear in the geometrically linear limit, which in particular allowed us to introduce the expression for the interface stresses consistent with the sharp interface approach. Namely, for the propagating nonequilibrium interface, a structural part of the interface Cauchy stresses reduces to a biaxial tension with the magnitude equal to the temperature-dependent interface energy. Additional elastic and viscous contributions to the interface stresses do not require separate constitutive equations and are determined by solution of the coupled system of phase field and mechanics equations. Ginzburg-Landau equations are derived for the evolution of the order parameters and temperature evolution equation. Boundary conditions for the order parameters include variation of the surface energy during phase transformation. Because elastic energy is defined per unit volume of unloaded (intermediate) configuration, additional contributions to the Ginzburg-Landau equations and the expression for entropy appear, which are important even for small strains. A complete system of equations for fifth- and sixth-degree polynomials in terms of the order parameters is presented in the reference and actual configurations. An analytical solution for the propagating interface and critical martensitic nucleus which includes distribution of components of interface stresses has been found for the sixth-degree polynomial. This required resolving a fundamental problem in the interface and surface science: how to define the Gibbsian dividing surface, i.e., the sharp interface equivalent to the finite-width interface. An unexpected, simple solution was found utilizing the principle of static equivalence. In fact, even two equations for determination of the

  17. Phase field simulations of plastic strain-induced phase transformations under high pressure and large shear

    NASA Astrophysics Data System (ADS)

    Javanbakht, Mahdi; Levitas, Valery I.

    2016-12-01

    Pressure and shear strain-induced phase transformations (PTs) in a nanograined bicrystal at the evolving dislocations pile-up have been studied utilizing a phase field approach (PFA). The complete system of PFA equations for coupled martensitic PT, dislocation evolution, and mechanics at large strains is presented and solved using the finite element method (FEM). The nucleation pressure for the high-pressure phase (HPP) under hydrostatic conditions near a single dislocation was determined to be 15.9 GPa. Under shear, a dislocation pile-up that appears in the left grain creates strong stress concentration near its tip and significantly increases the local thermodynamic driving force for PT, which causes nucleation of HPP even at zero pressure. At pressures of 1.59 and 5 GPa and shear, a major part of a grain transforms to HPP. When dislocations are considered in the transforming grain as well, they relax stresses and lead to a slightly smaller stationary HPP region than without dislocations. However, they strongly suppress nucleation of HPP and require larger shear. Unexpectedly, the stationary HPP morphology is governed by the simplest thermodynamic equilibrium conditions, which do not contain contributions from plasticity and surface energy. These equilibrium conditions are fulfilled either for the majority of points of phase interfaces or (approximately) in terms of stresses averaged over the HPP region or for the entire grain, despite the strong heterogeneity of stress fields. The major part of the driving force for PT in the stationary state is due to deviatoric stresses rather than pressure. While the least number of dislocations in a pile-up to nucleate HPP linearly decreases with increasing applied pressure, the least corresponding shear strain depends on pressure nonmonotonously. Surprisingly, the ratio of kinetic coefficients for PT and dislocations affect the stationary solution and the nanostructure. Consequently, there are multiple stationary solutions

  18. Mechanical Resonance Displaying Changes in Phase to Large Audiences.

    ERIC Educational Resources Information Center

    Dorner, R.; And Others

    1995-01-01

    Describes a lecture demonstration apparatus for displaying free and forced oscillations of a mechanical system to a large class. Discusses the Blinking Diode Display and the Standing Wave description. Contains 20 references. (JRH)

  19. Proximity nanovalve with large phase-tunable thermal conductance

    SciTech Connect

    Strambini, E. Giazotto, F.; Bergeret, F. S.

    2014-08-25

    We propose a phase-controlled heat-flux quantum valve based on the proximity effect driven by a superconducting quantum interference proximity transistor (SQUIPT). Its operation relies on the phase-dependent quasiparticle density of states in the Josephson weak-link of the SQUIPT which controls thermal transport across the device. In a realistic Al/Cu-based setup the structure can provide efficient control of thermal current inducing temperature swings exceeding ∼100 mK, and flux-to-temperature transfer coefficients up to ∼500 mK/Φ{sub 0} below 100 mK. The nanovalve performances improve by lowering the bath temperature, making the proposed structure a promising building-block for the implementation of coherent caloritronic devices operating below 1 K.

  20. Study of large nonlinear change phase in Hibiscus Sabdariffa

    NASA Astrophysics Data System (ADS)

    Trejo-Durán, M.; Alvarado-Méndez, E.; Andrade-Lucio, J. A.; Rojas-Laguna, R.; Vázquez-Guevara, M. A.

    2015-09-01

    High intensities electromagnetic energy interacting with organic media gives rise to nonlinear optical effects. Hibiscus Sabdariffa is a flower whose concentrated solution presents interesting nonlinear optical properties. This organic material shows an important self-phase modulation with changes bigger than 2π. We present a diffraction ring patterns study of the Hibiscus Sabdariffa solution. Numerical results of transmittance, with refraction and simultaneous absorption, are shown.

  1. Liquid argon scintillation light studies in LArIAT

    SciTech Connect

    Kryczynski, Pawel

    2016-10-12

    The LArIAT experiment is using its Liquid Argon Time Projection Chamber (LArTPC) in the second run of data-taking at the Fermilab Test Beam Facility. The goal of the experiment is to study the response of LArTPCs to charged particles of energies relevant for planned neutrino experiments. In addition, it will help to develop and evaluate the performance of the simulation, analysis, and reconstruction software used in other LAr neutrino experiments. Particles from a tertiary beam detected by LArIAT (mainly protons, pions and muons) are identified using a set of beamline detectors, including Wire Chambers, Time of Flight counters and Cherenkov counters, as well as a simplified sampling detector used to detect muons. In its effort towards augmenting LArTPC technology for other neutrino experiments, LArIAT also takes advantage of the scintillating capabilities of LAr and is testing the possibility of using the light signal to help reconstruct calorimetric information and particle ID. In this report, we present results from these studies of the scintillation light signal to evaluate detector performance and calorimetry.

  2. Large space telescope, phase A. Volume 3: Optical telescope assembly

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The development and characteristics of the optical telescope assembly for the Large Space Telescope are discussed. The systems considerations are based on mission-related parameters and optical equipment requirements. Information is included on: (1) structural design and analysis, (2) thermal design, (3) stabilization and control, (4) alignment, focus, and figure control, (5) electronic subsystem, and (6) scientific instrument design.

  3. Large space telescope, phase A. Volume 4: Scientific instrument package

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The design and characteristics of the scientific instrument package for the Large Space Telescope are discussed. The subjects include: (1) general scientific objectives, (2) package system analysis, (3) scientific instrumentation, (4) imaging photoelectric sensors, (5) environmental considerations, and (6) reliability and maintainability.

  4. Large space telescope, phase A. Volume 5: Support systems module

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The development and characteristics of the support systems module for the Large Space Telescope are discussed. The following systems and described: (1) thermal control, (2) electrical, (3) communication and data landing, (4) attitude control system, and (5) structural features. Analyses of maintainability and reliability considerations are included.

  5. ATLAS LAr calorimeter performance and LHC Run-2 commissioning

    NASA Astrophysics Data System (ADS)

    Spettel, Fabian

    2016-07-01

    The ATLAS detector was built to study proton-proton collisions produced by the Large Hadron Collider (LHC) at a center of mass energy of up to 14 TeV. The Liquid Argon (LAr) calorimeters are used for all electromagnetic calorimetry as well as the hadronic calorimetry in the endcap and forward regions. They have shown excellent performance during the first LHC data taking campaign, from 2010 to 2012, so-called Run 1, at a peak luminosity of 8 ×1033cm-2s-1. During the next run, peak luminosities of 1.5 ×1034cm-2s-1 and even higher are expected at a 25 ns bunch spacing. Such a high collision rate may have an impact on the quality of the energy reconstruction which is attempted to be maintained at a high level using a calibration procedure described in this contribution. It also poses major challenges to the first level of the trigger system which is constrained to a maximal rate of 100 kHz. For Run-3, scheduled to start in 2019, instantaneous luminosity as high as 3 ×1034cm-2s-1 are foreseen imposing an upgrade of the LAr trigger system to maintain its performance. A demonstrator containing prototypes of the upgraded trigger electronic architecture has been installed on one of the barrel electromagnetic calorimeter readout front end crates to test it during the Run-2 campaign. The new architecture and its benefits for data taking will be discussed below as well as the results from first beam splash events.

  6. Lessons learned with the Active Phasing Experiment: comparison of four optical phasing sensors on a segmented Very Large Telescope

    NASA Astrophysics Data System (ADS)

    Gonte, F.; Surdej, I.

    The adaptive optics capabilities are strongly limited by the quality of the phasing of the primary mirror of the extremely large telescope. Up to date, the Keck telescopes are the only segmented telescope phased with a quality enabling the application of adaptive optics. The Active Phasing Experiment has been installed at the Namyth focus of the Very Large Telescope Melipal during the last 6 months. Its purpose is to understand and compare different technological concepts for an optical phasing sensor dedicated to the European Extremely Large Telescope. The pupil of the telescope is segmented in 61 hexagonal segments by projecting it on an Active Segmented Mirror. The ASM is controlled by a dual wavenlength interferometer made by Fogale Nanotech with a nanometric precision. The segmented pupil is distributed in parallel to four optical phasing sensors. They are a pyramid sensor, a curvature sensor, a phase filtering sensor and a ShackHartmann sensor. They have been developed respectively by Istituto Nazionale di Astrofisica in Florenze, Instituto Astrofisica Canarias in Tenerife, Laboratoire d'Astrophysique de Marseille and ESO. The global behaviour of the optical phasing sensors will be described and preliminary results of the Active Phasing Experiments obtained on sky will be explained. The extrapolation of the results to the EELT and the potential consequences for the adaptive optics will be given. The Active Phasing Experiment has been financed by the European Union and the European Southern Observatory via the Sixth European Union Framework Program for Research and Technological Development under the contract number 011863.

  7. Phase Correlations and Topological Measures of Large-Scale Structure

    NASA Astrophysics Data System (ADS)

    Coles, P.

    The process of gravitational instability initiated by small primordial density perturbations is a vital ingredient of cosmological models that attempt to explain how galaxies and large-scale structure formed in the Universe. In the standard picture (the "concordance" model), a period of accelerated expansion ("inflation") generated density fluctuations with simple statistical properties through quantum processes (Starobinsky [82], [83], [84]; Guth [39]; Guth & Pi [40]; Albrecht & Steinhardt [2]; Linde [55]). In this scenario the primordial density field is assumed to form a statistically homogeneous and isotropic Gaussian random field (GRF). Over years of observational scrutiny this paradigm has strengthened its hold in the minds of cosmologists and has survived many tests, culminating in those furnished by the Wilkinson Microwave Anisotropy Probe (WMAP; Bennett et al. [7]; Hinshaw et al. [45].

  8. Large Area Crop Inventory Experiment (LACIE). Phase 1: Evaluation report

    NASA Technical Reports Server (NTRS)

    1976-01-01

    It appears that the Large Area Crop Inventory Experiment over the Great Plains, can with a reasonable expectation, be a satisfactory component of a 90/90 production estimator. The area estimator produced more accurate area estimates for the total winter wheat region than for the mixed spring and winter wheat region of the northern Great Plains. The accuracy does appear to degrade somewhat in regions of marginal agriculture where there are small fields and abundant confusion crops. However, it would appear that these regions tend also to be marginal with respect to wheat production and thus increased area estimation errors do not greatly influence the overall production estimation accuracy in the United States. The loss of segments resulting from cloud cover appears to be a random phenomenon that introduces no significant bias into the estimates. This loss does increase the variance of the estimates.

  9. Numerical modeling of the simulated gas hydrate production test at Mallik 2L-38 in the pilot scale pressure reservoir LARS - Applying the "foamy oil" model

    NASA Astrophysics Data System (ADS)

    Abendroth, Sven; Thaler, Jan; Klump, Jens; Schicks, Judith; Uddin, Mafiz

    2014-05-01

    In the context of the German joint project SUGAR (Submarine Gas Hydrate Reservoirs: exploration, extraction and transport) we conducted a series of experiments in the LArge Reservoir Simulator (LARS) at the German Research Centre of Geosciences Potsdam. These experiments allow us to investigate the formation and dissociation of hydrates at large scale laboratory conditions. We performed an experiment similar to the field-test conditions of the production test in the Mallik gas hydrate field (Mallik 2L-38) in the Beaufort Mackenzie Delta of the Canadian Arctic. The aim of this experiment was to study the transport behavior of fluids in gas hydrate reservoirs during depressurization (see also Heeschen et al. and Priegnitz et al., this volume). The experimental results from LARS are used to provide details about processes inside the pressure vessel, to validate the models through history matching, and to feed back into the design of future experiments. In experiments in LARS the amount of methane produced from gas hydrates was much lower than expected. Previously published models predict a methane production rate higher than the one observed in experiments and field studies (Uddin et al. 2010; Wright et al. 2011). The authors of the aforementioned studies point out that the current modeling approach overestimates the gas production rate when modeling gas production by depressurization. They suggest that trapping of gas bubbles inside the porous medium is responsible for the reduced gas production rate. They point out that this behavior of multi-phase flow is not well explained by a "residual oil" model, but rather resembles a "foamy oil" model. Our study applies Uddin's (2010) "foamy oil" model and combines it with history matches of our experiments in LARS. Our results indicate a better agreement between experimental and model results when using the "foamy oil" model instead of conventional models of gas flow in water. References Uddin M., Wright J.F. and Coombe D

  10. APE: the Active Phasing Experiment to test new control system and phasing technology for a European Extremely Large Optical Telescope

    NASA Astrophysics Data System (ADS)

    Gonte, F.; Yaitskova, N.; Derie, F.; Constanza, A.; Brast, R.; Buzzoni, B.; Delabre, B.; Dierickx, P.; Dupuy, C.; Esteves, R.; Frank, C.; Guisard, S.; Karban, R.; Koenig, E.; Kolb, J.; Nylund, M.; Noethe, L.; Surdej, I.; Courteville, A.; Wilhelm, R.; Montoya, L.; Reyes, M.; Esposito, S.; Pinna, E.; Dohlen, K.; Ferrari, M.; Langlois, M.

    2005-08-01

    The future European Extremely Large Telescope will be composed of one or two giant segmented mirrors (up to 100 m of diameter) and of several large monolithic mirrors (up to 8 m in diameter). To limit the aberrations due to misalignments and defective surface quality it is necessary to have a proper active optics system. This active optics system must include a phasing system to limit the degradation of the PSF due to misphasing of the segmented mirrors. We will present the lastest design and development of the Active Phasing Experiment that will be tested in laboratory and on-sky connected to a VLT at Paranal in Chile. It includes an active segmented mirror, a static piston plate to simulate a secondary segmented mirror and of four phasing wavefront sensors to measure the piston, tip and tilt of the segments and the aberrations of the VLT. The four phasing sensors are the Diffraction Image Phase Sensing Instrument developed by Instituto de Astrofisica de Canarias, the Pyramid Phasing Sensor developed by Arcetri Astrophysical Observatory, the Shack-Hartmann Phasing Sensor developed by the European Southern Observatory and the Zernike Unit for Segment phasing developed by Laboratoire d'Astrophysique de Marseille. A reference measurement of the segmented mirror is made by an internal metrology developed by Fogale Nanotech. The control system of Active Phasing Experiment will perform the phasing of the segments, the guiding of the VLT and the active optics of the VLT. These activities are included in the Framework Programme 6 of the European Union.

  11. Large-angle and high-efficiency tunable phase grating using fringe field switching liquid crystal.

    PubMed

    Xu, Daming; Tan, Guanjun; Wu, Shin-Tson

    2015-05-04

    We propose a switchable phase grating using fringe field switching (FFS) cells. The FFS phase grating possesses several attractive features: large diffraction angle, high diffraction efficiency, fast response time, and high contrast ratio. It can diffract >32% light to ± 2nd orders with a large diffraction angle of 12.1°. Meanwhile, its response time remains relatively fast even at -40°C. A simulation model is developed to explain the experimental results and good agreement is obtained. We also demonstrate a blazed phase grating to achieve tunable beam steering between 0th, 1st and 2nd orders.

  12. Bibliographic Automation of Large Library Operations Using a Time-Sharing System: Phase I. Final Report.

    ERIC Educational Resources Information Center

    Epstein, A. H.; And Others

    The first phase of an ongoing library automation project at Stanford University is described. Project BALLOTS (Bibliographic Automation of Large Library Operations Using a Time-Sharing System) seeks to automate the acquisition and cataloging functions of a large library using an on-line time-sharing computer. The main objectives are to control…

  13. Selective expression of CSPG receptors PTPσ and LAR in poorly regenerating reticulospinal neurons of lamprey.

    PubMed

    Zhang, Guixin; Hu, Jianli; Li, Shuxin; Huang, Lisa; Selzer, Michael E

    2014-06-15

    Disability following spinal cord injury is due to failure of axon regeneration, which has been ascribed to environmental factors in the central nervous system and a developmental loss of intrinsic growth capacity in neurons. Recently, the receptor-like protein tyrosine phosphatases, protein tyrosine phosphatase σ (PTPσ) and leukocyte common antigen-related phosphatase (LAR), have been identified as specific receptors for the regeneration-inhibiting matrix molecules chondroitin sulfate proteoglycans (CSPGs). After spinal cord transection in lampreys, axons of the large, identified reticulospinal neurons have heterogeneous regenerative abilities. The bad-regenerating neurons also undergo a delayed form of axotomy-induced apoptosis. In the present study, a lamprey genomic database was used to identify homologs of CSPGs, clone PTPσ and LAR, and examine their mRNA expression. CSPG immunoreactivity was increased significantly near the lesion at 2 weeks post transection, and decreased thereafter. Both receptors were expressed selectively in the bad-regenerating neurons and had overlapping cellular distributions. PTPσ was upregulated with age (LAR was not evaluated). By 2 weeks post transection, neurons expressing PTPσ also showed caspase activation, suggesting apoptosis. The probability of axon regeneration for individual identified neurons was negatively correlated with the expression level of PTPσ in both control and spinal cord-transected lampreys. In an animal 7 weeks post transection, regenerated axons were labeled retrogradely from beyond the transection. PTPσ expression and caspase labeling was seen only in neurons whose axon had not regenerated. These results are consistent with a possible role for PTPσ (and LAR) in both retrograde neuronal death and the poor intrinsic regenerative ability of bad-regenerating neurons.

  14. Theory of Multifarious Quantum Phases and Large Anomalous Hall Effect in Pyrochlore Iridate Thin Films.

    PubMed

    Hwang, Kyusung; Kim, Yong Baek

    2016-07-15

    We theoretically investigate emergent quantum phases in the thin film geometries of the pyrochore iridates, where a number of exotic quantum ground states are proposed to occur in bulk materials as a result of the interplay between electron correlation and strong spin-orbit coupling. The fate of these bulk phases as well as novel quantum states that may arise only in the thin film platforms, are studied via a theoretical model that allows layer-dependent magnetic structures. It is found that the magnetic order develop in inhomogeneous fashions in the thin film geometries. This leads to a variety of magnetic metal phases with modulated magnetic ordering patterns across different layers. Both the bulk and boundary electronic states in these phases conspire to promote unusual electronic properties. In particular, such phases are akin to the Weyl semimetal phase in the bulk system and they would exhibit an unusually large anomalous Hall effect.

  15. Theory of Multifarious Quantum Phases and Large Anomalous Hall Effect in Pyrochlore Iridate Thin Films

    NASA Astrophysics Data System (ADS)

    Hwang, Kyusung; Kim, Yong Baek

    2016-07-01

    We theoretically investigate emergent quantum phases in the thin film geometries of the pyrochore iridates, where a number of exotic quantum ground states are proposed to occur in bulk materials as a result of the interplay between electron correlation and strong spin-orbit coupling. The fate of these bulk phases as well as novel quantum states that may arise only in the thin film platforms, are studied via a theoretical model that allows layer-dependent magnetic structures. It is found that the magnetic order develop in inhomogeneous fashions in the thin film geometries. This leads to a variety of magnetic metal phases with modulated magnetic ordering patterns across different layers. Both the bulk and boundary electronic states in these phases conspire to promote unusual electronic properties. In particular, such phases are akin to the Weyl semimetal phase in the bulk system and they would exhibit an unusually large anomalous Hall effect.

  16. Theory of Multifarious Quantum Phases and Large Anomalous Hall Effect in Pyrochlore Iridate Thin Films

    PubMed Central

    Hwang, Kyusung; Kim, Yong Baek

    2016-01-01

    We theoretically investigate emergent quantum phases in the thin film geometries of the pyrochore iridates, where a number of exotic quantum ground states are proposed to occur in bulk materials as a result of the interplay between electron correlation and strong spin-orbit coupling. The fate of these bulk phases as well as novel quantum states that may arise only in the thin film platforms, are studied via a theoretical model that allows layer-dependent magnetic structures. It is found that the magnetic order develop in inhomogeneous fashions in the thin film geometries. This leads to a variety of magnetic metal phases with modulated magnetic ordering patterns across different layers. Both the bulk and boundary electronic states in these phases conspire to promote unusual electronic properties. In particular, such phases are akin to the Weyl semimetal phase in the bulk system and they would exhibit an unusually large anomalous Hall effect. PMID:27418293

  17. Lars Onsager Prize: Phase transitions in massive data acquisition

    NASA Astrophysics Data System (ADS)

    Mezard, Marc

    The rapid increase in the amount of data that is presently being generated, acquired and processed opens new perspectives in many branches of science. In order to take full advantage of this « data revolution », and to turn it into a major tool for scientific discoveries, new concepts and methods need to be developed, thus allowing us to focus on the extraction of significant information. Referring to the case of compressed sensing, the talk will show how ideas and methods in statistical physics -from spin glass theory to cristal nucleation - can help design faster, less destructive, and more efficient signal acquisition protocols, with possible applications into numerous fields -from magnetic resonance imaging to astronomy, tomography, or gene interaction network reconstruction.

  18. Inter- and intraspecific variation in the diets of sympatric siamang (Hylobates syndactylus) and lar gibbons (Hylobates lar).

    PubMed

    Palombit, R A

    1997-01-01

    Studies of the siamang (Hylobates syndactylus continentis) and the lar gibbon (Hylobates lar lar) where they co-occur in mainland Asia have demonstrated interspecific dietary segregation based on body size and have suggested that observed levels of frugivory represent metabolically based maxima for these species. I studied sympatric groups of siamang (H. s. syndactylus) and lar gibbons (H. l. vestitus) at Ketambe in northern Sumatra (Indonesia) in order to assess the magnitude of within- and between-species variation in diets. The insular subspecies are considerably more frugivorous (60-70% of feeding time) than mainland conspecifics (35-50%). This is primarily because Sumatran hylobatids spend about twice as much time (approx. 45% of feeding) eating fig fruits (Ficus spp., Moraceae). A higher density of figs at Ketambe (compared to Kuala Lompat) may account for this behavioral difference. Enhanced frugivory has been achieved at the expense of folivory, which is much reduced in Sumatra--especially in H. lar (4% of diet)- and is limited almost entirely to immature foliage. The expected decline in protein intake resulting from diminished folivory in Sumatra may be counterbalanced by observed increases in insectivory, which is especially pronounced in lar gibbons. Interspecific dietary segregation emerges most clearly in how individuals of each species supplement their similarly fig-dominated diets. Siamang rely more on immature foliage--primarily from lianas, which generate young leaves more reliably and abundantly than trees do. Conversely, lar gibbons exploit the pulpy fruit of trees and lianas more heavily than siamang do. This general pattern occurs where the two species coexist in Malaysia, thereby suggesting a substantive interspecific difference that is somewhat greater in the insular populations.

  19. Scintillation Light Detection System in LArIAT

    SciTech Connect

    Kryczynski, Pawel

    2016-02-29

    The LArIAT experiment is currently taking data at Fermilab using a Liquid Argon TPC, with the aim of studying particle interactions and characterizing detector response for neutrino detectors using argon. In parallel, it serves as a test-bench to develop and evaluate the performance of the simulation, reconstruction, and analysis software used in LAr neutrino experiments. LArIAT also takes advantage of the scintillating capabilities of liquid argon and will evaluate the feasibility of using the light signal to determine calorimetric information and particle identification. To test this possibility, a scintillation light detection system consisting of high Quantum Efficiency (QE) PMT and Silicon Photomultiplier (SiPM) devices is installed in the cryostat, viewing the interior of the TPC. Light collection efficiency is maximized by means of lining the walls with reflector foils covered by a wavelength shifter layer. Collecting the light reflected at the boundaries of the active volume greatly improves also the uniformity of the light yield. Presented here are initial results of the LArIAT light detection system calibration together with the preliminary results of the dedicated simulation and its application in future LAr TPC experiments

  20. Advection Scheme for Phase-changing Porous Media Flow of Fluids with Large Density Ratio

    NASA Astrophysics Data System (ADS)

    Zhang, Duan; Padrino, Juan

    2015-11-01

    Many flows in a porous media involve phase changes between fluids with a large density ratio. For instance, in the water-steam phase change the density ratio is about 1000. These phase changes can be results of physical changes, or chemical reactions, such as fuel combustion in a porous media. Based on the mass conservation, the velocity ratio between the fluids is of the same order of the density ratio. As the result the controlling Courant number for the time step in a numerical simulation is determined by the high velocity and low density phase, leading to small time steps. In this work we introduce a numerical approximation to increase the time step by taking advantage of the large density ratio. We provide analytical error estimation for this approximate numerical scheme. Numerical examples show that using this approximation about 40-fold speedup can be achieved at the cost of a few percent error. Work partially supported by LDRD project of LANL.

  1. Characterization and stabilising dynamic phase fluctuations in large mode area fibres

    NASA Astrophysics Data System (ADS)

    Jones, D. C.; Scott, A. M.

    2007-02-01

    Fibre amplifiers exhibit rapid time dependent phase fluctuations due to the environment and to thermal and other effects associated with the pumping and lasing processes. We characterise these effects in a large mode area fibre amplifier having an output power of 260W limited only by pump power. The amplifier retains its coherence even at the highest available output power with negligible linewidth broadening. Phase fluctuations are characterised by a low-amplitude power-independent jitter superimposed on a power-dependent drift due to heating. We also measure the phase fluctuations in a COTS fibre preamplifier and find they are predominantly large amplitude periodic oscillations at 110Hz, probably induced by pump power fluctuations. The two amplifiers were combined in series to give a high gain amplifier chain and actively phase stabilised to high precision (~λ/37 rms) using a piezo-ceramic fibre stretcher incorporated into a PC-based feedback loop.

  2. Large vibrational effects upon calculated phase boundaries in Al-Sc.

    PubMed

    Ozoliņs, V; Asta, M

    2001-01-15

    The fcc portion of the Al-Sc phase diagram is calculated from first principles including contributions to alloy free energies associated with ionic vibrations. It is found that vibrational entropy accounts for a 27-fold increase in the calculated solubility limits for Sc in fcc Al at high temperatures, bringing calculated and measured values into very good agreement. The present work gives a clear example demonstrating a large effect of vibrational entropy upon calculated phase boundaries in substitutional alloys.

  3. Recent R&D results on LAr LEM TPC and plans for LBNO demonstrators

    NASA Astrophysics Data System (ADS)

    Cantini, C.; Epprecht, L.; Gendotti, A.; Horikawa, S.; Murphy, S.; Natterer, G.; Periale, L.; Regenfus, C.; Resnati, F.; Rubbia, A.; Sergiampietri, F.; Viant, T.; Wu, S.; LAGUNA-LBNO Collaboration; WA105 Collaboration

    2015-11-01

    The double phase Liquid Argon (LAr) Time Projection Chamber (TPC) is the state-of-art technology for neutrino detection thanks to its superb 3 Dimensional (3D) tracking and calorimetry performance. Based on this technology, the Giant Liquid Argon Charge Imaging ExpeRiment (GLACIER) is proposed to be the far detector for the Long Baseline Neutrino Oscillation (LBNO) experiment aiming at studying neutrinos 2300 km away from their production point. We report recent R&D results on the charge readout system for GLACIER and the plans to build the GLACIER demonstrators at CERN.

  4. Phase diagram and criticality of the random anisotropy model in the large-N limit

    NASA Astrophysics Data System (ADS)

    Mouhanna, Dominique; Tarjus, Gilles

    2016-12-01

    We revisit the thermodynamic behavior of the random-anisotropy O(N ) model by investigating its large-N limit. We focus on the system at zero temperature where the mean-field-like artifacts of the large-N limit are less severe. We analyze the connection between the description in terms of self-consistent Schwinger-Dyson equations and the functional renormalization group. We provide a unified description of the phase diagram and critical behavior of the model and clarify the nature of the possible "glassy" phases. Finally we discuss the implications of our findings for the finite-N and finite-temperature systems.

  5. Large aperture interferometer with phase-conjugate self-reference beam

    NASA Technical Reports Server (NTRS)

    Howes, W. L.

    1986-01-01

    A large aperture self-referencing interferometer consisting of a Twyman-Green interferometer using a self-pumped phase conjugator in series with test section optics is described and experimentally demonstrated. This interferometer provides twice the fringe shift of a Mach-Zehnder (M-Z) interferometer for a given optical phase change induced within the test section. It also provides greater irradiance in the reference beam than does a similar series setup utilizing a M-Z interferometer incorporating a local reference beam. Whereas the ordinary interferometer records instantaneous conditions, the new one records overage conditions if a BaTiO3 crystal is used as the phase conjugator.

  6. Reduced gravity and ground testing of a two-phase thermal management system for large spacecraft

    NASA Technical Reports Server (NTRS)

    Hill, D. G.; Hsu, K.; Parish, R.; Dominick, J.

    1988-01-01

    Experiments were performed aboard the NASA-JSC KC-135 aircraft to study the effect of reduced gravity on two-phase (liquid/vapor) flow and condensation. A prototype two-phase thermal management system for a large spacecraft was tested. Both visual observation and photography of the flow regimes were made. Ground test simulations of the KC-135 flight tests were conducted for comparison purposes. Two-phase pressure drops were predictable by the Heat Transfer Research Institute (HTRI) method, or the Friedel correlation.

  7. Two phase sampling for wheat acreage estimation. [large area crop inventory experiment

    NASA Technical Reports Server (NTRS)

    Thomas, R. W.; Hay, C. M.

    1977-01-01

    A two phase LANDSAT-based sample allocation and wheat proportion estimation method was developed. This technique employs manual, LANDSAT full frame-based wheat or cultivated land proportion estimates from a large number of segments comprising a first sample phase to optimally allocate a smaller phase two sample of computer or manually processed segments. Application to the Kansas Southwest CRD for 1974 produced a wheat acreage estimate for that CRD within 2.42 percent of the USDA SRS-based estimate using a lower CRD inventory budget than for a simulated reference LACIE system. Factor of 2 or greater cost or precision improvements relative to the reference system were obtained.

  8. Lasso Peptide Biosynthetic Protein LarB1 Binds Both Leader and Core Peptide Regions of the Precursor Protein LarA

    PubMed Central

    2016-01-01

    Lasso peptides are a member of the superclass of ribosomally synthesized and posttranslationally modified peptides (RiPPs). Like all RiPPs, lasso peptides are derived from a gene-encoded precursor protein. The biosynthesis of lasso peptides requires two enzymatic activities: proteolytic cleavage between the leader peptide and the core peptide in the precursor protein, accomplished by the B enzymes, and ATP-dependent isopeptide bond formation, accomplished by the C enzymes. In a subset of lasso peptide biosynthetic gene clusters from Gram-positive organisms, the B enzyme is split between two proteins. One such gene cluster is found in the organism Rhodococcus jostii, which produces the antimicrobial lasso peptide lariatin. The B enzyme in R. jostii is split between two open reading frames, larB1 and larB2, both of which are required for lariatin biosynthesis. While the cysteine catalytic triad is found within the LarB2 protein, LarB1 is a PqqD homologue expected to bind to the lariatin precursor LarA based on its structural homology to other RiPP leader peptide binding domains. We show that LarB1 binds to the leader peptide of the lariatin precursor protein LarA with a sub-micromolar affinity. We used photocrosslinking with the noncanonical amino acid p-azidophenylalanine and mass spectrometry to map the interaction of LarA and LarB1. This analysis shows that the LarA leader peptide interacts with a conserved motif within LarB1 and, unexpectedly, the core peptide of LarA also binds to LarB1 in several positions. A Rosetta model built from distance restraints from the photocrosslinking experiments shows that the scissile bond between the leader peptide and core peptide in LarA is in a solvent-exposed loop. PMID:27800552

  9. Lasso Peptide Biosynthetic Protein LarB1 Binds Both Leader and Core Peptide Regions of the Precursor Protein LarA.

    PubMed

    Cheung, Wai Ling; Chen, Maria Y; Maksimov, Mikhail O; Link, A James

    2016-10-26

    Lasso peptides are a member of the superclass of ribosomally synthesized and posttranslationally modified peptides (RiPPs). Like all RiPPs, lasso peptides are derived from a gene-encoded precursor protein. The biosynthesis of lasso peptides requires two enzymatic activities: proteolytic cleavage between the leader peptide and the core peptide in the precursor protein, accomplished by the B enzymes, and ATP-dependent isopeptide bond formation, accomplished by the C enzymes. In a subset of lasso peptide biosynthetic gene clusters from Gram-positive organisms, the B enzyme is split between two proteins. One such gene cluster is found in the organism Rhodococcus jostii, which produces the antimicrobial lasso peptide lariatin. The B enzyme in R. jostii is split between two open reading frames, larB1 and larB2, both of which are required for lariatin biosynthesis. While the cysteine catalytic triad is found within the LarB2 protein, LarB1 is a PqqD homologue expected to bind to the lariatin precursor LarA based on its structural homology to other RiPP leader peptide binding domains. We show that LarB1 binds to the leader peptide of the lariatin precursor protein LarA with a sub-micromolar affinity. We used photocrosslinking with the noncanonical amino acid p-azidophenylalanine and mass spectrometry to map the interaction of LarA and LarB1. This analysis shows that the LarA leader peptide interacts with a conserved motif within LarB1 and, unexpectedly, the core peptide of LarA also binds to LarB1 in several positions. A Rosetta model built from distance restraints from the photocrosslinking experiments shows that the scissile bond between the leader peptide and core peptide in LarA is in a solvent-exposed loop.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  11. Phase transitions as the origin of large scale structure in the universe

    NASA Technical Reports Server (NTRS)

    Turok, Neil

    1989-01-01

    A review of the formation of large scale structure through gravitational growth of primordial perturbations is given. This is followed by a discussion of how symmetry breaking phase transitions in the early universe might have produced the required perturbations, in particular through the formation and evolution of a network of cosmic strings.

  12. Development of a Solid Phase Extraction Method for Agricultural Pesticides in Large-Volume Water Samples

    EPA Science Inventory

    An analytical method using solid phase extraction (SPE) and analysis by gas chromatography/mass spectrometry (GC/MS) was developed for the trace determination of a variety of agricultural pesticides and selected transformation products in large-volume high-elevation lake water sa...

  13. Effect of misalignments on phase-locking in a large area discharge CO2 laser

    NASA Astrophysics Data System (ADS)

    Xu, Yonggen; Wang, Shijian; Du, Quan; Ma, Zairu; Ji, Yupin; Li, Yude

    2015-08-01

    The line deviations and angle deviations of the injected beam at the resonator mirrors in the large area discharge CO2 laser (LADCL) are changed when the output mirror and the phase-locking mirror (PLM) are misaligned. The equiphase surfaces excited by the injected beam are different in the laser resonator and the effect of phase-locking will be influenced. It is shown that the misalignment of PLM is the main cause of phase-locking range reduction. The misalignment of the output mirror will mainly result in the deviation of the output beam, and the misalignment of the PLM will mainly cause decrease of the light intensity. And the maximum misaligned angle should not exceed 20 s in order to obtain the ideal effect of phase-locking. The calculated results can provide references for studying deeply the misalignment of LADCL.

  14. Some Fruits of Genius: Lars Onsager and the Ising Model

    NASA Astrophysics Data System (ADS)

    Fisher, Michael E.

    2006-03-01

    The story of the exact solution of the two-dimensional Ising model by Lars Onsager in the 1940's will be sketched and some of the striking developments following from it, especially for the behavior of fluctuating interfaces, will be recounted.

  15. LAR, liprin alpha and the regulation of active zone morphogenesis.

    PubMed

    Stryker, Emily; Johnson, Karl G

    2007-11-01

    Active zones are protein-rich regions of neurons that act as sites of synaptic vesicle fusion and neurotransmitter release at the pre-synaptic terminus. Although the discovery that the receptor protein tyrosine phosphatase LAR and its cytoplasmic binding partner liprin alpha are essential for proper active zone formation is nearly a decade old, the underlying mechanisms are still poorly understood. Recent studies have identified a number of binding partners for both LAR and liprin alpha, several of which play key roles in active zone assembly. These include nidogen, dallylike and syndecan--extracellular ligands for LAR that regulate synapse morphogenesis. In addition, liprin-alpha-interacting proteins such as ERC2, RIM and the MALS/Veli-Cask-Mint1 complex cooperate to form a dense molecular scaffold at the active zone that is crucial for proper synaptic function. These studies allow us to propose testable models of LAR and liprin alpha function, and provide insights into the fundamental molecular mechanisms of synapse formation and stabilization.

  16. ConvexLAR: An Extension of Least Angle Regression*

    PubMed Central

    Xiao, Wei; Zhou, Hua

    2016-01-01

    The least angle regression (LAR) was proposed by Efron, Hastie, Johnstone and Tibshirani (2004) for continuous model selection in linear regression. It is motivated by a geometric argument and tracks a path along which the predictors enter successively and the active predictors always maintain the same absolute correlation (angle) with the residual vector. Although it gains popularity quickly, its extensions seem rare compared to the penalty methods. In this expository article, we show that the powerful geometric idea of LAR can be generalized in a fruitful way. We propose a ConvexLAR algorithm that works for any convex loss function and naturally extends to group selection and data adaptive variable selection. After simple modification it also yields new exact path algorithms for certain penalty methods such as a convex loss function with lasso or group lasso penalty. Variable selection in recurrent event and panel count data analysis, Ada-Boost, and Gaussian graphical model is reconsidered from the ConvexLAR angle. PMID:27114697

  17. Operation plan for the data 100/LARS terminal system

    NASA Technical Reports Server (NTRS)

    Bowen, A. J., Jr.

    1980-01-01

    The Data 100/LARS terminal system provides an interface for processing on the IBM 3031 computer system at Purdue University's Laboratory for Applications of Remote Sensing. The environment in which the system is operated and supported is discussed. The general support responsibilities, procedural mechanisms, and training established for the benefit of the system users are defined.

  18. Residues cluster-based segmentation and outlier-detection method for large-scale phase unwrapping.

    PubMed

    Yu, Hanwen; Li, Zhenfang; Bao, Zheng

    2011-10-01

    2-D phase unwrapping is an important technique in many applications. However, with the growth of image scale, how to tile and splice the image effectively has become a new challenge. In this paper, the phase unwrapping problem is abstracted as solving a large-scale system of inconsistent linear equations. With the difficulties of large-scale phase unwrapping analyzed, L(0)-norm criterion is found to have potentials in efficient image tiling and splicing. Making use of the clustering characteristic of residue distribution, a tiling strategy is proposed for L(0)-norm criterion. Unfortunately, L(0)-norm is an NP-hard problem, which is very difficult to find an exact solution in a polynomial time. In order to effectively solve this problem, equations corresponding to branch cuts of L(0)-norm in the inconsistent equation system mentioned earlier are considered as outliers, and then an outlier-detection-based phase unwrapping method is proposed. Through this method, a highly accurate approximate solution to this NP-hard problem is achieved. A set of experimental results shows that the proposed approach can avoid the inconsistency between local and global phase unwrapping solutions caused by image tiling.

  19. Liquid crystal spatial light modulator with very large phase modulation operating in high harmonic orders.

    PubMed

    Calero, Venancio; García-Martínez, Pascuala; Albero, Jorge; Sánchez-López, María M; Moreno, Ignacio

    2013-11-15

    Unusually large phase modulation in a commercial liquid crystal spatial light modulator (LCSLM) is reported. Such a situation is obtained by illuminating with visible light a device designed to operate in the infrared range. The phase modulation range reaches 6π radians in the red region of the visible spectrum and 10π radians in the blue region. Excellent diffraction efficiency in high harmonic orders is demonstrated despite a concomitant and non-negligible Fabry-Perot interference effect. This type of SLM opens the possibility to implement diffractive elements with reduced chromatic dispersion or chromatic control.

  20. Thick strings, the liquid crystal blue phase, and cosmological large-scale structure

    NASA Technical Reports Server (NTRS)

    Luo, Xiaochun; Schramm, David N.

    1992-01-01

    A phenomenological model based on the liquid crystal blue phase is proposed as a model for a late-time cosmological phase transition. Topological defects, in particular thick strings and/or domain walls, are presented as seeds for structure formation. It is shown that the observed large-scale structure, including quasi-periodic wall structure, can be well fitted in the model without violating the microwave background isotropy bound or the limits from induced gravitational waves and the millisecond pulsar timing. Furthermore, such late-time transitions can produce objects such as quasars at high redshifts. The model appears to work with either cold or hot dark matter.

  1. SALTO: a randomized, multicenter study assessing octreotide LAR in inoperable bowel obstruction.

    PubMed

    Laval, Guillemette; Rousselot, Hubert; Toussaint-Martel, Sophie; Mayer, Françoise; Terrebonne, Eric; François, Eric; Brixi, Hédia; Nguyen, Thierry; Bourdeix, Isabelle; Bisot-Locard, Ségolène; Zelek, Laurent

    2012-02-01

    This phase II, multicenter, randomized, double-blind, non-comparative study assessed the efficacy and safety of immediate-release octreotide and octreotide LAR, in combination with corticosteroids and standard medical care, on the symptoms of inoperable malignant bowel obstruction (MBO) due to peritoneal carcinomatosis. The primary efficacy endpoint was "success" at day 14 defined as a composite endpoint including the absence of a nasogastric tube, and vomiting less than twice per day and no use of anticholinergic agents. Patients in the octreotide arm received octreotide LAR 30 mg intramuscular (im) on days 1, 29 and 57, as well as daily immediate-release octreotide 600 μg per day plus methylprednisolone on days 1 to 6. Placebo-treated patients received methylprednisolone and matched placebo instead of octreotide. Difficulties associated with enrolling patients at palliative-care stage meant only 64 patients (instead of the planned 102 patients) were randomized, 32 to octreotide and 32 to placebo. Despite randomization, more patients in the octreotide arm (46.4%) than in the placebo arm (21.9%) had a baseline Karnofsky score less than 50. An intention-to-treat analysis showed that in the octreotide and placebo arms, 12 (38%) and nine (28%), respectively, patients were successfully treated at day 14, which increased to 9/15 (60%) and 7/25 (28%), respectively, among patients with a baseline Karnofsky score greater or equal to 50. Octreotide-treated patients reported three drug-related adverse events (AEs), and no drug-related serious AEs or deaths. Octreotide LAR may have a key role in treating patients with a MBO due to peritoneal carcinomatosis, particularly in those with moderately severe disease.

  2. Development of an ADC radiation tolerance characterization system for the upgrade of the ATLAS LAr calorimeter

    NASA Astrophysics Data System (ADS)

    Liu, Hong-Bin; Chen, Hu-Cheng; Chen, Kai; Kierstead, James; Lanni, Francesco; Takai, Helio; Jin, Ge

    2017-02-01

    ATLAS LAr calorimeter will undergo its Phase-I upgrade during the long shutdown (LS2) in 2018, and a new LAr Trigger Digitizer Board (LTDB) will be designed and installed. Several commercial-off-the-shelf (COTS) multi-channel high-speed ADCs have been selected as possible backups of the radiation tolerant ADC ASICs for the LTDB. To evaluate the radiation tolerance of these backup commercial ADCs, we developed an ADC radiation tolerance characterization system, which includes the ADC boards, data acquisition (DAQ) board, signal generator, external power supplies and a host computer. The ADC board is custom designed for different ADCs, with ADC drivers and clock distribution circuits integrated on board. The Xilinx ZC706 FPGA development board is used as a DAQ board. The data from the ADC are routed to the FPGA through the FMC (FPGA Mezzanine Card) connector, de-serialized and monitored by the FPGA, and then transmitted to the host computer through the Gigabit Ethernet. A software program has been developed with Python, and all the commands are sent to the DAQ board through Gigabit Ethernet by this program. Two ADC boards have been designed for the ADC, ADS52J90 from Texas Instruments and AD9249 from Analog Devices respectively. TID tests for both ADCs have been performed at BNL, and an SEE test for the ADS52J90 has been performed at Massachusetts General Hospital (MGH). Test results have been analyzed and presented. The test results demonstrate that this test system is very versatile, and works well for the radiation tolerance characterization of commercial multi-channel high-speed ADCs for the upgrade of the ATLAS LAr calorimeter. It is applicable to other collider physics experiments where radiation tolerance is required as well. Supported by the U. S. Department of Energy (DE-SC001270)

  3. Large deployable antenna program. Phase 1: Technology assessment and mission architecture

    NASA Technical Reports Server (NTRS)

    Rogers, Craig A.; Stutzman, Warren L.

    1991-01-01

    The program was initiated to investigate the availability of critical large deployable antenna technologies which would enable microwave remote sensing missions from geostationary orbits as required for Mission to Planet Earth. Program goals for the large antenna were: 40-meter diameter, offset-fed paraboloid, and surface precision of 0.1 mm rms. Phase 1 goals were: to review the state-of-the-art for large, precise, wide-scanning radiometers up to 60 GHz; to assess critical technologies necessary for selected concepts; to develop mission architecture for these concepts; and to evaluate generic technologies to support the large deployable reflectors necessary for these missions. Selected results of the study show that deployable reflectors using furlable segments are limited by surface precision goals to 12 meters in diameter, current launch vehicles can place in geostationary only a 20-meter class antenna, and conceptual designs using stiff reflectors are possible with areal densities of 2.4 deg/sq m.

  4. Simulating the gas hydrate production test at Mallik using the pilot scale pressure reservoir LARS

    NASA Astrophysics Data System (ADS)

    Heeschen, Katja; Spangenberg, Erik; Schicks, Judith M.; Priegnitz, Mike; Giese, Ronny; Luzi-Helbing, Manja

    2014-05-01

    LARS, the LArge Reservoir Simulator, allows for one of the few pilot scale simulations of gas hydrate formation and dissociation under controlled conditions with a high resolution sensor network to enable the detection of spatial variations. It was designed and built within the German project SUGAR (submarine gas hydrate reservoirs) for sediment samples with a diameter of 0.45 m and a length of 1.3 m. During the project, LARS already served for a number of experiments simulating the production of gas from hydrate-bearing sediments using thermal stimulation and/or depressurization. The latest test simulated the methane production test from gas hydrate-bearing sediments at the Mallik test site, Canada, in 2008 (Uddin et al., 2011). Thus, the starting conditions of 11.5 MPa and 11°C and environmental parameters were set to fit the Mallik test site. The experimental gas hydrate saturation of 90% of the total pore volume (70 l) was slightly higher than volumes found in gas hydrate-bearing formations in the field (70 - 80%). However, the resulting permeability of a few millidarcy was comparable. The depressurization driven gas production at Mallik was conducted in three steps at 7.0 MPa - 5.0 MPa - 4.2 MPa all of which were used in the laboratory experiments. In the lab the pressure was controlled using a back pressure regulator while the confining pressure was stable. All but one of the 12 temperature sensors showed a rapid decrease in temperature throughout the sediment sample, which accompanied the pressure changes as a result of gas hydrate dissociation. During step 1 and 2 they continued up to the point where gas hydrate stability was regained. The pressure decreases and gas hydrate dissociation led to highly variable two phase fluid flow throughout the duration of the simulated production test. The flow rates were measured continuously (gas) and discontinuously (liquid), respectively. Next to being discussed here, both rates were used to verify a model of gas

  5. WA105: a large-scale demonstrator of the Liquid Argon double phase TPC

    NASA Astrophysics Data System (ADS)

    Tonazzo, A.; WA105 Collaboration

    2016-05-01

    The physics case for a large underground detector devoted to neutrino oscillation measurements, nucleon decay and astrophysics is compelling. A time projection chamber based on the dual-phase liquid Argon technique is an extremely attractive option, allowing for long drift distances, low energy threshold and high readout granularity. It has been extensively studied in the LAGUNA-LBNO Design Study and is one of the two designs foreseen for the modules of the DUNE detector in the US. The WA105 experiment envisages the construction of a large scale prototype at CERN, to validate technical solutions and perform physics studies with charged particle beams.

  6. Co-Phasing the Large Binocular Telescope:. [Status and Performance of LBTI-PHASECam

    NASA Technical Reports Server (NTRS)

    Defrere, D.; Hinz, P.; Downey, E.; Ashby, D.; Bailey, V.; Brusa, G.; Christou, J.; Danchi, W. C.; Grenz, P.; Hill, J. M.; Hoffmann, W. F.; Leisenring, J.; Lozi, J.; McMahon, T.; Mennesson, B.; Millan-Gabet, R.; Montoya, M.; Powell, K.; Skemer, A.; Vaitheeswaran, V.; Vaz, A.; Veillet, C.

    2014-01-01

    The Large Binocular Telescope Interferometer is a NASA-funded nulling and imaging instrument designed to coherently combine the two 8.4-m primary mirrors of the LBT for high-sensitivity, high-contrast, and high-resolution infrared imaging (1.5-13 micrometer). PHASECam is LBTI's near-infrared camera used to measure tip-tilt and phase variations between the two AO-corrected apertures and provide high-angular resolution observations. We report on the status of the system and describe its on-sky performance measured during the first semester of 2014. With a spatial resolution equivalent to that of a 22.8-meter telescope and the light-gathering power of single 11.8-meter mirror, the co-phased LBT can be considered to be a forerunner of the next-generation extremely large telescopes (ELT).

  7. Phase diagram of a two-dimensional large- Q Potts model in an external field

    NASA Astrophysics Data System (ADS)

    Tsai, Shan-Ho; Landau, D. P.

    2009-04-01

    We use a two-dimensional Wang-Landau sampling algorithm to map out the phase diagram of a Q-state Potts model with Q⩽10 in an external field H that couples to one state. Finite-size scaling analyses show that for large Q the first-order phase transition point at H=0 is in fact a triple point at which three first-order phase transition lines meet. One such line is restricted to H=0; another line has H⩽0. The third line, which starts at the H=0 triple point, ends at a critical point (T,H) which needs to be located in a two-dimensional parameter space. The critical field H(Q) is positive and decreases with decreasing Q, which is in qualitative agreement with previous predictions.

  8. Chemical ordering suppresses large-scale electronic phase separation in doped manganites

    NASA Astrophysics Data System (ADS)

    Zhu, Yinyan; Du, Kai; Niu, Jiebin; Lin, Lingfang; Wei, Wengang; Liu, Hao; Lin, Hanxuan; Zhang, Kai; Yang, Tieying; Kou, Yunfang; Shao, Jian; Gao, Xingyu; Xu, Xiaoshan; Wu, Xiaoshan; Dong, Shuai; Yin, Lifeng; Shen, Jian

    2016-04-01

    For strongly correlated oxides, it has been a long-standing issue regarding the role of the chemical ordering of the dopants on the physical properties. Here, using unit cell by unit cell superlattice growth technique, we determine the role of chemical ordering of the Pr dopant in a colossal magnetoresistant (La1-yPry)1-xCaxMnO3 (LPCMO) system, which has been well known for its large length-scale electronic phase separation phenomena. Our experimental results show that the chemical ordering of Pr leads to marked reduction of the length scale of electronic phase separations. Moreover, compared with the conventional Pr-disordered LPCMO system, the Pr-ordered LPCMO system has a metal-insulator transition that is ~100 K higher because the ferromagnetic metallic phase is more dominant at all temperatures below the Curie temperature.

  9. Observation of ferroelectric phase and large spontaneous electric polarization in organic salt of diisopropylammonium iodide

    NASA Astrophysics Data System (ADS)

    Saripalli, Ravi K.; Swain, Diptikanta; Prasad, Siva; Nhalil, Hariharan; Bhat, Handady L.; Guru Row, Tayur N.; Elizabeth, Suja

    2017-03-01

    In this manuscript, we explore diisopropylammonium iodide (DPI) for its ferroelectric properties and phase transitions. DPI showed two phase transitions which were identified by differential scanning calorimetry and dielectric and nonlinear optical measurements. From detailed structural studies it was found that the first transition at 369 K is from orthorhombic P212121 to monoclinic P21. The polar P21 phase is ferroelectric as evidenced by the pyroelectric data and has a very high value of spontaneous polarization (Ps = 33 μC cm-2), which is probably the highest among other reported bulk organic ferroelectrics. The second transition at 415 K is identified as polar monoclinic P21 space group to non-polar monoclinic P21/m. Thus, DPI has a high Curie temperature of 415 K. The large spontaneous polarization and high Curie temperature make DPI technologically important.

  10. Synchronization of Stochastically Coupled Oscillators: Dynamical Phase Transitions and Large Deviations Theory (or Birds and Frogs)

    NASA Astrophysics Data System (ADS)

    Teodorescu, Razvan

    2009-10-01

    Systems of oscillators coupled non-linearly (stochastically or not) are ubiquitous in nature and can explain many complex phenomena: coupled Josephson junction arrays, cardiac pacemaker cells, swarms or flocks of insects and birds, etc. They are know to have a non-trivial phase diagram, which includes chaotic, partially synchronized, and fully synchronized phases. A traditional model for this class of problems is the Kuramoto system of oscillators, which has been studied extensively for the last three decades. The model is a canonical example for non-equilibrium, dynamical phase transitions, so little understood in physics. From a stochastic analysis point of view, the transition is described by the large deviations principle, which offers little information on the scaling behavior near the critical point. I will discuss a special case of the model, which allows a rigorous analysis of the critical properties of the model, and reveals a new, anomalous scaling behavior in the vicinity of the critical point.

  11. Chemical ordering suppresses large-scale electronic phase separation in doped manganites

    PubMed Central

    Zhu, Yinyan; Du, Kai; Niu, Jiebin; Lin, Lingfang; Wei, Wengang; Liu, Hao; Lin, Hanxuan; Zhang, Kai; Yang, Tieying; Kou, Yunfang; Shao, Jian; Gao, Xingyu; Xu, Xiaoshan; Wu, Xiaoshan; Dong, Shuai; Yin, Lifeng; Shen, Jian

    2016-01-01

    For strongly correlated oxides, it has been a long-standing issue regarding the role of the chemical ordering of the dopants on the physical properties. Here, using unit cell by unit cell superlattice growth technique, we determine the role of chemical ordering of the Pr dopant in a colossal magnetoresistant (La1−yPry)1−xCaxMnO3 (LPCMO) system, which has been well known for its large length-scale electronic phase separation phenomena. Our experimental results show that the chemical ordering of Pr leads to marked reduction of the length scale of electronic phase separations. Moreover, compared with the conventional Pr-disordered LPCMO system, the Pr-ordered LPCMO system has a metal–insulator transition that is ∼100 K higher because the ferromagnetic metallic phase is more dominant at all temperatures below the Curie temperature. PMID:27053071

  12. Laboratory photometric measurement of particulate soils out to very large phase angles

    NASA Technical Reports Server (NTRS)

    Helfenstein, Paul; Bonne, Ulrich A.; Stolovy, Susan; Veverka, Joseph

    1991-01-01

    In the present study, the objectives were to develop the laboratory methods and tools to conduct photometric observations of dark particulate samples over a large range of phase angles and to demonstrate whether forward scattering behavior can be seen in a surface constructed of low albedo material. The researchers also examined the adequacy of various model formulations of P (alpha) to describe the effective scattering properties of their sample.

  13. Phase retrieval from a single near-field diffraction pattern with a large Fresnel number.

    PubMed

    Li, Enrong; Liu, Yijin; Liu, Xiaosong; Zhang, Kai; Wang, Zhili; Hong, Youli; Yuan, Qingxi; Huang, Wanxia; Marcelli, Augusto; Zhu, Peiping; Wu, Ziyu

    2008-11-01

    A new method of phase retrieval from a single near-field diffraction image with a large Fresnel number is presented and discussed. This method requires only the oversampled diffraction pattern without any other information such as the object envelope. Moreover, we show that the combination with a fast computational method is possible when the linear oversampling ratio is an integer. Numerical simulations are also presented, showing that the method works well with noisy data.

  14. Obituary: Gary Lars Grasdalen, 1945-2003

    NASA Astrophysics Data System (ADS)

    Strom, Stephen Eric

    2003-12-01

    With the passing of Gary Grasdalen on 20 April 2003 the astronomical community has lost one its most creative members. Born in Albert Lea, Minnesota on 7 October 1945 to the farming family of Lars G. and Lillie Grasdalen, Gary developed a strong childhood interest in science, and a particular fascination with astronomy. In 1964, he entered Harvard College intending to pursue those interests. During his freshman year, Gary enrolled in an undergraduate research seminar in which he first displayed the combination of keen insight and imagination in applying new techniques that was manifest throughout his professional career. In 1968, he published his first two papers---studies of the C12/C13 ratio in metal deficient stars, and of Fe I and Fe II transition probabilities---which summarized research carried out during his junior and senior years at Harvard. Grasdalen next entered the astronomy graduate program at the University of California, Berkeley. There he developed a strong interest in the early stages of stellar evolution and, in particular, the potential of S-1 image intensifiers and newly available near-infrared detectors to detect and analyze the stellar populations embedded within their parent molecular cloud complexes. Following award of his PhD in 1972, Grasdalen was appointed to the staff at the Kitt Peak National Observatory. Early in his career at KPNO, Gary developed tools that enabled routine near-infrared mapping of nearby molecular cloud complexes, most notably the telescope control programs that enabled precise raster scanning of these regions. Those same programs were some of the many innovations in which Gary had a hand. These innovations enabled a generation of KPNO observers in the 1970s to fully exploit the power of the newly commissioned Mayall telescope as well as the smaller telescopes on Kitt Peak. In 1973, he published the first map of the central region of a molecular cloud, which revealed an extensive embedded, optically obscured

  15. Top eigenvalue of a random matrix: large deviations and third order phase transition

    NASA Astrophysics Data System (ADS)

    Majumdar, Satya N.; Schehr, Grégory

    2014-01-01

    We study the fluctuations of the largest eigenvalue λmax of N × N random matrices in the limit of large N. The main focus is on Gaussian β ensembles, including in particular the Gaussian orthogonal (β = 1), unitary (β = 2) and symplectic (β = 4) ensembles. The probability density function (PDF) of λmax consists, for large N, of a central part described by Tracy-Widom distributions flanked, on both sides, by two large deviation tails. While the central part characterizes the typical fluctuations of λmax—of order {O}(N^{-2/3}) —the large deviation tails are instead associated with extremely rare fluctuations—of order {O}(1). Here we review some recent developments in the theory of these extremely rare events using a Coulomb gas approach. We discuss in particular the third order phase transition which separates the left tail from the right tail, a transition akin to the so-called Gross-Witten-Wadia phase transition found in 2-d lattice quantum chromodynamics. We also discuss the occurrence of similar third order transitions in various physical problems, including non-intersecting Brownian motions, conductance fluctuations in mesoscopic physics and entanglement in a bipartite system.

  16. W phase source inversion using high-rate regional GPS data for large earthquakes

    NASA Astrophysics Data System (ADS)

    Riquelme, S.; Bravo, F.; Melgar, D.; Benavente, R.; Geng, J.; Barrientos, S.; Campos, J.

    2016-04-01

    W phase moment tensor inversion has proven to be a reliable method for rapid characterization of large earthquakes. For global purposes it is used at the United States Geological Survey, Pacific Tsunami Warning Center, and Institut de Physique du Globe de Strasbourg. These implementations provide moment tensors within 30-60 min after the origin time of moderate and large worldwide earthquakes. Currently, the method relies on broadband seismometers, which clip in the near field. To ameliorate this, we extend the algorithm to regional records from high-rate GPS data and retrospectively apply it to six large earthquakes that occurred in the past 5 years in areas with relatively dense station coverage. These events show that the solutions could potentially be available 4-5 min from origin time. Continuously improving GPS station availability and real-time positioning solutions will provide significant enhancements to the algorithm.

  17. Simulation of incompressible two-phase flow in porous media with large timesteps

    NASA Astrophysics Data System (ADS)

    Cogswell, Daniel; Szulczewski, Michael

    2016-11-01

    Simulations of flow in porous media suffer from severe timestep restrictions as the permeability and viscosity contrast become increasingly heterogeneous, even when solved with a fully implicit discretization. Previous efforts to alleviate these restrictions have focused on numerical methods, but the problem persists because it originates from the shape of the fractional flow function. Here we focus on regularizing the equations themselves with the addition of an energy constraint. The equations for the flow of two immiscible, incompressible fluid phases in porous media are recast as a gradient flow using the phase-field method, a macroscopic surface tension is introduced, and a convex energy splitting scheme is applied to enable unconditionally large timesteps. Using the phase-field formulation as a homotopy map, the unmodified flow equations can be solved with large timesteps, even with high degrees of heterogeneity in permeability and viscosity. For a 2D test problem, the homotopy method allows the timestep to be increased by more than four orders of magnitude relative to the unmodified equations.

  18. Recent Enhancements of the Phased Array Mirror Extendible Large Aperture (PAMELA) Telescope Testbed at MSFC

    NASA Technical Reports Server (NTRS)

    Rakoczy, John; Montgomery, Edward E.; Lindner, Jeff

    2000-01-01

    Recent incremental upgrades to the Phased Array Mirror Extendible Large Aperture (PAMELA) telescope testbed have enabled the demonstration of phasing (with a monochromatic source) of clusters of primary mirror segments down to the diffraction limit. PAMELA upgrades include an improved Shack-Hartmann wavefront sensor, passive viscoelastic damping treatments for the voice-coil actuators, mechanical improvement of mirror surface figures, and optical bench baffling. This report summarizes the recent PAMELA upgrades, discusses the lessons learned, and presents a status of this unique testbed for wavefront sensing and control. The Marshall Space Flight Center acquired the Phased Array Mirror Extendible Large Aperture (PAMELA) telescope in 1993 after Kaman Aerospace was unable to complete integration and testing under the limited SDIO and DARPA funding. The PAMELA is a 36-segment, half-meter aperture, adaptive telescope which utilizes a Shack-Hartmann wavefront sensor, inductive coil edge sensors, voice coil actuators, imaging CCD cameras and interferometry for figure alignment, wavefront sensing and control. MSFC originally obtained the PAMELA to supplement its research in the interactions of control systems with flexible structures. In August 1994, complete tip, tilt and piston control was successfully demonstrated using the Shack-Hartmann wavefront sensor and the inductive edge sensors.

  19. Recent Enhancements of the Phased Array Mirror Extendible Large Aperture (PAMELA) Telescope Testbed at MSFC

    NASA Technical Reports Server (NTRS)

    Rakoczy, John; Burdine, Robert (Technical Monitor)

    2001-01-01

    Recent incremental upgrades to the Phased Array Mirror Extendible Large Aperture (PAMELA) telescope testbed have enabled the demonstration of phasing (with a monochromatic source) of clusters of primary mirror segments down to the diffraction limit. PAMELA upgrades include in improved Shack-Hartmann wavefront sensor, passive viscoelastic damping treatments for the voice-coil actuators, mechanical improvement of mirror surface figures, and optical bench baffling. This report summarizes the recent PAMELA upgrades, discusses the lessons learned, and presents a status of this unique testbed for wavefront sensing and control. The Marshall Space Flight Center acquired the Phased Array Mirror Extendible Large Aperture (PAMELA) telescope in 1993 after Kaman Aerospace was unable to complete integration and testing under the limited SDIO and DARPA funding. The PAMELA is a 36-segment, half-meter aperture, adaptive telescope which utilizes a Shack-Hartmann wavefront sensor, inductive coil edge sensors, voice coil actuators, imaging CCD cameras and interferometry for figure alignment, wavefront sensing and control. MSFC originally obtained the PAMELA to supplement its research in the interactions of control systems with flexible structures. In August 1994, complete tip, tilt and piston control was successfully demonstrated using the Shack-Hartmann wavefront sensor and the inductive edge sensors.

  20. Stability Training for Convolutional Neural Nets in LArTPC

    NASA Astrophysics Data System (ADS)

    Lindsay, Matt; Wongjirad, Taritree

    2017-01-01

    Convolutional Neural Nets (CNNs) are the state of the art for many problems in computer vision and are a promising method for classifying interactions in Liquid Argon Time Projection Chambers (LArTPCs) used in neutrino oscillation experiments. Despite the good performance of CNN's, they are not without drawbacks, chief among them is vulnerability to noise and small perturbations to the input. One solution to this problem is a modification to the learning process called Stability Training developed by Zheng et al. We verify existing work and demonstrate volatility caused by simple Gaussian noise and also that the volatility can be nearly eliminated with Stability Training. We then go further and show that a traditional CNN is also vulnerable to realistic experimental noise and that a stability trained CNN remains accurate despite noise. This further adds to the optimism for CNNs for work in LArTPCs and other applications.

  1. The liquid annular reactor system (LARS) for deep space exploration

    NASA Astrophysics Data System (ADS)

    Maise, George; Paniagua, John; Powell, James R.; Ludewig, Hans; Todosow, Michael

    1999-05-01

    A new propulsion concept for high Δ V space missions, termed LARS (Liquid Annular Reactor System), uses liquid nuclear fuel elements to heat hydrogen propellant to very high temperatures (-6000 K). The molten fuel is contained in a lower-temperature solid container which rotates to stabilize and hold in the liquid layer by centripetal force. Containment of ultra high temperature molten refractories, using this method, has been experimentally demonstrated by A.V. Grosse. The specific impulse of a rocket exhausting hydrogen at 6000 K is 2000 seconds, approximately double that of solid-core nuclear rockets. A LARS-powered space probe could accomplish extra-solar missions to 550 A.U. in approximately 35 years.

  2. Thirumŭlar--pioneer of the immunology concept.

    PubMed

    Rajasekaran, R; Narayana, Ala

    2006-01-01

    Extraordinary longevity of life, made possible by repeated reading and following of the text Thirumandiram 3000 - written by great Siddhar Thirumŭlar. He the Prince of Mystics is one of the 18 luminous Siddhars and the first and foremost #1 Siva śiddhăndi. Historians and scholars predicted his life period between 5th to 8th centuries AD. In his teachings, he explained the kinds of 'Thavam' (Yoga) and he insisted the #2 'Kăya siddhi'. Thousands of years ago, he wrote in detail about Anatomy of microcosm, Siddha physiology, Humoural pathology, Science of pulse, Microcosmic Atom theory, Immunology concept and Immortalization of our body. His marvelous text Thirumandiram deals with Medical science, Life science, Natural science and Divine. In this article authors, discuss about the biography of Thirumŭlar and his medical works.

  3. LAR: More Than Just a System, It is a Mindset

    DTIC Science & Technology

    2011-04-26

    8217 as: prepared in cooperation with; translation of; report supersedes; old edition number, etc. 14. ABSTRACT. A brief (approximately 200. words ...factual summary of the most significant information. 15. SUBJECT TERMS. Key words or phrases identifying major concepts in the report. 16. SECURITY...Military Operations in Urban Terrain ( MOUT ) and what should be considered in the employment ofLAR units?5 The MCWP 3-14 is woefully inadequate in defining

  4. Large-Actuator-Number Horizontal Path Correction of Atmospheric Turbulence utilizing an Interferometric Phase Conjugate Engine

    SciTech Connect

    Baker, K L; Stappaerts, E A; Gavel, D; Tucker, J; Silva, D A; Wilks, S C; Olivier, S S; Olsen, J

    2004-08-25

    An adaptive optical system used to correct horizontal beam propagation paths has been demonstrated. This system utilizes an interferometric wave-front sensor and a large-actuator-number MEMS-based spatial light modulator to correct the aberrations incurred by the beam after propagation along the path. Horizontal path correction presents a severe challenge to adaptive optics systems due to the short atmospheric transverse coherence length and the high degree of scintillation incurred by laser propagation along these paths. Unlike wave-front sensors that detect phase gradients, however, the interferometric wave-front sensor measures the wrapped phase directly. Because the system operates with nearly monochromatic light and uses a segmented spatial light modulator, it does not require that the phase be unwrapped to provide a correction and it also does not require a global reconstruction of the wave-front to determine the phase as required by gradient detecting wave-front sensors. As a result, issues with branch points are eliminated. Because the atmospheric probe beam is mixed with a large amplitude reference beam, it can be made to operate in a photon noise limited regime making its performance relatively unaffected by scintillation. The MEMS-based spatial light modulator in the system contains 1024 pixels and is controlled to speeds in excess of 800 Hz, enabling its use for correction of horizontal path beam propagation. In this article results are shown of both atmospheric characterization with the system and open loop horizontal path correction of a 1.53 micron laser by the system. To date Strehl ratios of greater than 0.5 have been achieved.

  5. Role of CSPG receptor LAR phosphatase in restricting axon regeneration after CNS injury

    PubMed Central

    Xu, Bin; Park, Dongsun; Ohtake, Yosuke; Li, Hui; Hayat, Umar; Li, Junjun; Selzer, Michael E.; Longo, Frank M.; Li, Shuxin

    2014-01-01

    Extracellular matrix molecule chondroitin sulfate proteoglycans (CSPGs) are highly upregulated in scar tissues and form a potent chemical barrier for CNS axon regeneration. Recent studies support that the receptor protein tyrosine phosphatase σ (PTPσ) and its subfamily member leukocyte common antigen related phosphatase (LAR) act as transmembrane receptors to mediate CSPG inhibition. PTPσ deficiency increased regrowth of ascending axons into scar tissues and descending corticospinal tract (CST) axons into the caudal spinal cord after spinal cord injury (SCI). Pharmacological LAR inhibition enhanced serotonergic axon growth in SCI mice. However, transgenic LAR deletion on axon growth in vivo and role of LAR in regulating regrowth of other fiber tracts have not been studied. Here, we studied role of LAR in restricting regrowth of injured descending CNS axons in deficient mice. LAR deletion increased regrowth of serotonergic axons into scar tissues and caudal spinal cord after dorsal overhemitransection. LAR deletion also stimulated regrowth of CST fibers into the caudal spinal cord. LAR protein was upregulated days to weeks after injury and co-localized to serotonergic and CST axons. Moreover, LAR deletion improved functional recovery by increasing BMS locomotor scores and stride length and reducing grid walk errors. This is the first transgenic study that demonstrates crucial role of LAR in restricting regrowth of injured CNS axons. PMID:25220840

  6. Gas-phase purification enables accurate, large-scale, multiplexed proteome quantification with isobaric tagging

    PubMed Central

    Wenger, Craig D; Lee, M Violet; Hebert, Alexander S; McAlister, Graeme C; Phanstiel, Douglas H; Westphall, Michael S; Coon, Joshua J

    2011-01-01

    We describe a mass spectrometry method, QuantMode, which improves the accuracy of isobaric tag–based quantification by alleviating the pervasive problem of precursor interference—co-isolation of impurities—through gas-phase purification. QuantMode analysis of a yeast sample ‘contaminated’ with interfering human peptides showed substantially improved quantitative accuracy compared to a standard scan, with a small loss of spectral identifications. This technique will allow large-scale, multiplexed quantitative proteomics analyses using isobaric tagging. PMID:21963608

  7. A portable surface plasmon resonance biosensor capable of phase interrogation in a large dynamic range

    NASA Astrophysics Data System (ADS)

    Chen, How-Foo; Chuang, Hsin-Yuan; Chen, Chih-Hang; Chang, Yun-Hsiang

    2014-08-01

    With the development of a point of care (POC) biosensor in mind, a polymer-molding prism with double parabolic surfaces is invented and developed to implement an ultra-compact SPR biosensor with extremely high sensitivity. The polymer molded parabolic prism is cost effective and disposable, thus cross contamination between biological samples can be avoided. A highly sensitive biosensor with a form factor less than 15cm*15cm*5cm was received with a tunable excitation angle of light beam for a large dynamic range. A highly sensitive optical phase interrogation was demonstrated. The biosensor is also compatible to a modern microscopy platform.

  8. Phase transitions as the origin of large scale structure in the universe

    NASA Technical Reports Server (NTRS)

    Turok, Neil

    1988-01-01

    A review of the formation of large scale structure through gravitational growth of primordial perturbations is given. This is followed by a discussion of how symmetry breaking phase transitions in the early universe might have produced the required perturbations, in particular through the formation and evolution of a network of cosmic strings. Finally, the statistical mechanics of string networks, for both cosmic and fundamental strings is discussed, leading to some more speculative ideas on the possible role of fundamental strings (superstrings or heterotic strings) in the very early universe.

  9. W phase source inversion for moderate to large earthquakes (1990-2010)

    USGS Publications Warehouse

    Duputel, Zacharie; Rivera, Luis; Kanamori, Hiroo; Hayes, Gavin P.

    2012-01-01

    Rapid characterization of the earthquake source and of its effects is a growing field of interest. Until recently, it still took several hours to determine the first-order attributes of a great earthquake (e.g. Mw≥ 7.5), even in a well-instrumented region. The main limiting factors were data saturation, the interference of different phases and the time duration and spatial extent of the source rupture. To accelerate centroid moment tensor (CMT) determinations, we have developed a source inversion algorithm based on modelling of the W phase, a very long period phase (100–1000 s) arriving at the same time as the P wave. The purpose of this work is to finely tune and validate the algorithm for large-to-moderate-sized earthquakes using three components of W phase ground motion at teleseismic distances. To that end, the point source parameters of all Mw≥ 6.5 earthquakes that occurred between 1990 and 2010 (815 events) are determined using Federation of Digital Seismograph Networks, Global Seismographic Network broad-band stations and STS1 global virtual networks of the Incorporated Research Institutions for Seismology Data Management Center. For each event, a preliminary magnitude obtained from W phase amplitudes is used to estimate the initial moment rate function half duration and to define the corner frequencies of the passband filter that will be applied to the waveforms. Starting from these initial parameters, the seismic moment tensor is calculated using a preliminary location as a first approximation of the centroid. A full CMT inversion is then conducted for centroid timing and location determination. Comparisons with Harvard and Global CMT solutions highlight the robustness of W phase CMT solutions at teleseismic distances. The differences in Mw rarely exceed 0.2 and the source mechanisms are very similar to one another. Difficulties arise when a target earthquake is shortly (e.g. within 10 hr) preceded by another large earthquake, which disturbs the

  10. Possibility of large final state interaction phases in light of B --> kpi and pipi data

    PubMed

    Hou; Yang

    2000-05-22

    The newly observed &Bmacr;( 0)-->&Kmacr;( 0)pi(0) mode is quite sizable while pi(-)pi(+) is rather small. Data also hint at pi(-)pi(0) greater, similarpi(-)pi(+). Though consistent with zero, central values of CP violating asymmetries in K-pi(+,0) and &Kmacr;( 0)pi(-) show an interesting pattern. Taking cue from these, we suggest that, besides gamma identical witharg(V(*)(ub)) being large, the rescattering phase delta in Kpi and pipi modes may be greater than 90 degrees. If this is true, not only the above trends can be accounted for, but one would also find pi(0)pi(0) approximately pi(-)pi(+,0), and the CP asymmetry in &Bmacr;( 0) vs B0-->pi(-)pi(+) could be as large as -60%. These results can be tested in a couple of years.

  11. Application and Operations Concepts of Large Transmit Phased Array of Parabolic Reflectors

    NASA Technical Reports Server (NTRS)

    Amoozegar, Farid

    2006-01-01

    The primary motive for large transmit array of parabolic reflectors, also known as Uplink Array, was to explore alternate methods in order to replace the large 70m antennas of Deep Space Network (DSN) such that the core capability for emergency support to a troubled spacecraft in deep space is preserved. Given that the Uplink Array is a new technology, the focus has always been on its feasibility and phase calibration techniques, which by itself is quite a challenge. It would be interesting to examine, however, what else could be accomplished by the Uplink Array capability other than the emergency support to a troubled spacecraft in deep space. ... The objective of this paper is to discuss a few application scenarios and the corresponding operation concepts, such as lunar positioning system, high EIRP uplink and the synergies with solar radar, and high power RF beams.

  12. Magnetic properties and large magnetocaloric effect in Laves phase metallic compound

    NASA Astrophysics Data System (ADS)

    Gao, Tian; Qi, Ningning; Zhang, Yufeng; Zhou, Tao

    2014-12-01

    We investigated the magnetic properties and magnetocaloric effect of C15 Laves phase TbMn1.6Fe0.4 by magnetization and heat capacity measurements. A sharp second-order magnetic Tb-Tb ordering transition at Curie temperature TC ~ 120 K and a short-range Fe-Fe ordering transition at ~230 K are observed. Around TC, the compound shows a large magnetocaloric effect with no obvious thermal and magnetic hysteresis loss. The maximum value of magnetic entropy change reaches 8.72 J kg-1 K-1 for a magnetic field change ΔH = 7 T over a wide temperature range. The obtained relative cooling power reaches 184, 560, and 803 J kg-1 for ΔH = 2, 5 and 7 T, respectively. Large reversible magnetocaloric effect and the wide operating temperature range indicate that TbMn1.6Fe0.4 could be a promising candidate for magnetic refrigeration.

  13. An optical spectrum of a large isolated gas-phase PAH cation: C78H26+

    PubMed Central

    Zhen, Junfeng; Mulas, Giacomo; Bonnamy, Anthony; Joblin, Christine

    2016-01-01

    A gas-phase optical spectrum of a large polycyclic aromatic hydrocarbon (PAH) cation - C78H26+- in the 410-610 nm range is presented. This large all-benzenoid PAH should be large enough to be stable with respect to photodissociation in the harsh conditions prevailing in the interstellar medium (ISM). The spectrum is obtained via multi-photon dissociation (MPD) spectroscopy of cationic C78H26 stored in the Fourier Transform Ion Cyclotron Resonance (FT-ICR) cell using the radiation from a mid-band optical parametric oscillator (OPO) laser. The experimental spectrum shows two main absorption peaks at 431 nm and 516 nm, in good agreement with a theoretical spectrum computed via time-dependent density functional theory (TD-DFT). DFT calculations indicate that the equilibrium geometry, with the absolute minimum energy, is of lowered, nonplanar C2 symmetry instead of the more symmetric planar D2h symmetry that is usually the minimum for similar PAHs of smaller size. This kind of slightly broken symmetry could produce some of the fine structure observed in some diffuse interstellar bands (DIBs). It can also favor the folding of C78H26+ fragments and ultimately the formation of fullerenes. This study opens up the possibility to identify the most promising candidates for DIBs amongst large cationic PAHs. PMID:26942230

  14. Phase boundary propagation in large LiFePO4 single crystals on delithiation.

    PubMed

    Weichert, Katja; Sigle, Wilfried; van Aken, Peter A; Jamnik, Janez; Zhu, Changbao; Amin, Ruhul; Acartürk, Tolga; Starke, Ulrich; Maier, Joachim

    2012-02-15

    Large single crystals of LiFePO(4) have been chemically delithiated. The relevance of chemical oxidation in comparison with electrochemical delithiation is discussed. Analyses of the Li content and profiles were done by electron energy loss spectroscopy and secondary ion mass spectrometry. The propagation of the FePO(4) phase growing on the surface of the large single crystal was followed by in situ optical microscopy as a function of time. The kinetics were evaluated in terms of linear irreversible thermodynamics and found to be characterized by an induction period followed by parabolic growth behavior of the FePO(4) phase indicating transport control. The growth rate was shown to depend on the crystallographic orientation. Scanning electron microscopy images showed cracks and a high porosity of the FePO(4) layer due to the significant changes in the molar volumes. The transport was found to be greatly enhanced by the porosity and crack formation and hence greatly enhanced over pure bulk transport, a result which is supposed to be very relevant for battery research if coarse-grained powder is used.

  15. Timing of Formal Phase Safety Reviews for Large-Scale Integrated Hazard Analysis

    NASA Technical Reports Server (NTRS)

    Massie, Michael J.; Morris, A. Terry

    2010-01-01

    Integrated hazard analysis (IHA) is a process used to identify and control unacceptable risk. As such, it does not occur in a vacuum. IHA approaches must be tailored to fit the system being analyzed. Physical, resource, organizational and temporal constraints on large-scale integrated systems impose additional direct or derived requirements on the IHA. The timing and interaction between engineering and safety organizations can provide either benefits or hindrances to the overall end product. The traditional approach for formal phase safety review timing and content, which generally works well for small- to moderate-scale systems, does not work well for very large-scale integrated systems. This paper proposes a modified approach to timing and content of formal phase safety reviews for IHA. Details of the tailoring process for IHA will describe how to avoid temporary disconnects in major milestone reviews and how to maintain a cohesive end-to-end integration story particularly for systems where the integrator inherently has little to no insight into lower level systems. The proposal has the advantage of allowing the hazard analysis development process to occur as technical data normally matures.

  16. An efficient pipeline wavefront phase recovery for the CAFADIS camera for extremely large telescopes.

    PubMed

    Magdaleno, Eduardo; Rodríguez, Manuel; Rodríguez-Ramos, José Manuel

    2010-01-01

    In this paper we show a fast, specialized hardware implementation of the wavefront phase recovery algorithm using the CAFADIS camera. The CAFADIS camera is a new plenoptic sensor patented by the Universidad de La Laguna (Canary Islands, Spain): international patent PCT/ES2007/000046 (WIPO publication number WO/2007/082975). It can simultaneously measure the wavefront phase and the distance to the light source in a real-time process. The pipeline algorithm is implemented using Field Programmable Gate Arrays (FPGA). These devices present architecture capable of handling the sensor output stream using a massively parallel approach and they are efficient enough to resolve several Adaptive Optics (AO) problems in Extremely Large Telescopes (ELTs) in terms of processing time requirements. The FPGA implementation of the wavefront phase recovery algorithm using the CAFADIS camera is based on the very fast computation of two dimensional fast Fourier Transforms (FFTs). Thus we have carried out a comparison between our very novel FPGA 2D-FFTa and other implementations.

  17. An Efficient Pipeline Wavefront Phase Recovery for the CAFADIS Camera for Extremely Large Telescopes

    PubMed Central

    Magdaleno, Eduardo; Rodríguez, Manuel; Rodríguez-Ramos, José Manuel

    2010-01-01

    In this paper we show a fast, specialized hardware implementation of the wavefront phase recovery algorithm using the CAFADIS camera. The CAFADIS camera is a new plenoptic sensor patented by the Universidad de La Laguna (Canary Islands, Spain): international patent PCT/ES2007/000046 (WIPO publication number WO/2007/082975). It can simultaneously measure the wavefront phase and the distance to the light source in a real-time process. The pipeline algorithm is implemented using Field Programmable Gate Arrays (FPGA). These devices present architecture capable of handling the sensor output stream using a massively parallel approach and they are efficient enough to resolve several Adaptive Optics (AO) problems in Extremely Large Telescopes (ELTs) in terms of processing time requirements. The FPGA implementation of the wavefront phase recovery algorithm using the CAFADIS camera is based on the very fast computation of two dimensional fast Fourier Transforms (FFTs). Thus we have carried out a comparison between our very novel FPGA 2D-FFTa and other implementations. PMID:22315523

  18. The First Pion-Ar Cross-Section Measurement with the LArIAT Experiment

    SciTech Connect

    Nutini, Irene

    2016-01-01

    A complete understanding of neutrinos properties requires a study and a characterization of the interactions of the daughter particles created in a neutrino-nucleus interaction. The Liquid Argon In A Testbeam (LArIAT) experiment is a small-scale liquid argon detector situated in the Fermilab Test Beam Facility. The LArIAT experiment is exposed to a tertiary beam comprised of mostly pions along with a mix of muons, protons, kaons, and electrons. LArIAT's goal is to characterize the response of the LArTPC to known incoming charged particles and measure their interactions in Argon, in order to understand their cross-sections and to help developing and tuning simulations and reconstruction algorithms for LArTPC neutrino experiments. The world's rst measurement of a pion cross-section on an Argon target, made with the LArIAT detector, is presented here.

  19. 77 FR 16559 - Large Power Transformers From Korea: Scheduling of the Final Phase of an Antidumping Investigation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-21

    ... COMMISSION Large Power Transformers From Korea: Scheduling of the Final Phase of an Antidumping Investigation... imports from Korea of large power transformers, provided for in subheading 8504.23.00 of the Harmonized... Commerce that imports of large power transformers from Korea are being sold in the United States at...

  20. LArIAT: Worlds First Pion-Argon Cross-Section

    SciTech Connect

    Hamilton, Pip

    2016-11-02

    The LArIAT experiment has performed the world's first measurement of the total charged-current pion cross-section on an argon target, using the repurposed ArgoNeuT detector in the Fermilab test beam. Presented here are the results of that measurement, along with an overview of the LArIAT experiment and details of the LArIAT collaboration's plans for future measurements.

  1. Magnetically responsive phase-change microspheres with large magnetization using ferrite nanoparticles.

    PubMed

    Du, Yufan; Wang, Yongsheng; He, Dawei; Feng, Bin; Ju, Changbin; Zhao, Huan; Fu, Ming

    2010-03-01

    Magnetically responsive phase-change microspheres were prepared and studied in this article. In the synthetic process, oleic acid was used to modify the iron oxide nanoparticles. The ferrite nanoparticles, about 10 nm in diameter, were highly dispersed due to the oleic acid on the surface of the particles, and they were encapsulated in polymethyl methacrylate (PMMA) by microemulsion polymerization with paraffin, which could be presumed from the differential scanning calorimetry (DSC) curves. According to the morphology in the scanning electron microscopy (SEM) image, the average diameter of the microspheres was about 200 nm, a large amount of nano-sized ferrite can be observed in a transmission electron microscope (TEM) image showing the structure of the microspheres. Finally, in the magnetization curve from a vibrating sample magnetometer, the saturation magnetization of microspheres was 12.2 emu/g, which was effective in the compatibility of infrared simulation and microwave absorption.

  2. Modelling the large strain solid phase deformation behaviour of polymer nanoclay composites

    NASA Astrophysics Data System (ADS)

    Spencer, P. E.; Spares, R.; Sweeney, J.; Coates, P. D.

    2008-12-01

    This work concerns the solid phase deformation processing of polypropylene/nanoclay composites, for which the materials are stretched to large tensile deformations at elevated temperatures. Under these conditions the polymer matrix is nonlinearly dependent on time and strain rate. A constitutive model that is a combination of an Eyring process and physically-based molecular chain models has been shown to give a good representation of the polymer behavior, which includes strain-rate dependent yielding and stress relaxation. In order to model the nanocomposite, platelike regions that are relatively stiff are introduced into a continuum of model polymer material. This is done using a Monte Carlo approach that sequentially places non-overlapping platelets in the matrix. The process for introducing the platelets has the potential to produce platelet orientation distributions that conform with prescribed statistics, such as may be deduced from observations on real nanocomposite.

  3. Experimental instrumentation system for the Phased Array Mirror Extendible Large Aperture (PAMELA) test program

    NASA Technical Reports Server (NTRS)

    Boykin, William H., Jr.

    1993-01-01

    Adaptive optics are used in telescopes for both viewing objects with minimum distortion and for transmitting laser beams with minimum beam divergence and dance. In order to test concepts on a smaller scale, NASA MSFC is in the process of setting up an adaptive optics test facility with precision (fraction of wavelengths) measurement equipment. The initial system under test is the adaptive optical telescope called PAMELA (Phased Array Mirror Extendible Large Aperture). Goals of this test are: assessment of test hardware specifications for PAMELA application and the determination of the sensitivities of instruments for measuring PAMELA (and other adaptive optical telescopes) imperfections; evaluation of the PAMELA system integration effort and test progress and recommended actions to enhance these activities; and development of concepts and prototypes of experimental apparatuses for PAMELA.

  4. The Late Gradual Phase of Large Flares: The Case of November 3, 2003

    NASA Astrophysics Data System (ADS)

    Auraß, H.

    2014-12-01

    The hard X-ray time profiles of most solar eruptive events begin with an impulsive phase that may be followed by a late gradual phase. In a recent article (Aurass et al. in Astron. Astrophys. 555, A40, 2013), we analyzed the impulsive phase of the solar eruptive event on November 3, 2003 in radio and X-ray emission. We found evidence of magnetic breakout reconnection using the radio diagnostic of the common effect of the flare current sheet and, at heights of ±0.4 R⊙, of a coronal breakout current sheet (a source site that we called X). In this article we investigate the radio emission during the late gradual phase of the previously analyzed event. The work is based on 40-400 MHz dynamic spectra (Radio Spectrograph Observatorium Tremsdorf, Leibniz Institut für Astrophysik Potsdam, AIP) combined with radio images obtained by the French Nançay Multifrequency Radio Heliograph (NRH) of the Observatoire de Paris, Meudon. Additionally we use Ramaty High Energy Solar Spectroscopic Imager (RHESSI) hard X-ray (HXR) flux records, and Solar and Heliospheric Observatory (SOHO) Large Angle and Spectrometric Coronagraph (LASCO) and Extreme ultraviolet Imaging Telescope (EIT) images. The analysis shows that the late gradual phase is subdivided into two distinct stages. Stage 1 (here lasting five minutes) is restricted to reoccurring radio emission at source site X. We observe plasma emission and an azimuthally moving source (from X toward the NE; speed ∼1200 kms) at levels radially ordered against the undisturbed coronal density gradient. These radio sources mark the lower boundary of an overdense region with a huge azimuthal extent. By the end of its motion, the source decays and reappears at point X. This is the onset of stage 2 traced here during its first 13 minutes. By this time, NRH sources observed at frequencies ≤236.6 MHz radially lift off with a speed of ∼400 kms (one third of the front speed of the coronal mass ejection (CME)) as one slowly decaying

  5. Kinetic Alfvén Wave Generation by Large-scale Phase Mixing

    NASA Astrophysics Data System (ADS)

    Vásconez, C. L.; Pucci, F.; Valentini, F.; Servidio, S.; Matthaeus, W. H.; Malara, F.

    2015-12-01

    One view of the solar wind turbulence is that the observed highly anisotropic fluctuations at spatial scales near the proton inertial length dp may be considered as kinetic Alfvén waves (KAWs). In the present paper, we show how phase mixing of large-scale parallel-propagating Alfvén waves is an efficient mechanism for the production of KAWs at wavelengths close to dp and at a large propagation angle with respect to the magnetic field. Magnetohydrodynamic (MHD), Hall magnetohydrodynamic (HMHD), and hybrid Vlasov-Maxwell (HVM) simulations modeling the propagation of Alfvén waves in inhomogeneous plasmas are performed. In the linear regime, the role of dispersive effects is singled out by comparing MHD and HMHD results. Fluctuations produced by phase mixing are identified as KAWs through a comparison of polarization of magnetic fluctuations and wave-group velocity with analytical linear predictions. In the nonlinear regime, a comparison of HMHD and HVM simulations allows us to point out the role of kinetic effects in shaping the proton-distribution function. We observe the generation of temperature anisotropy with respect to the local magnetic field and the production of field-aligned beams. The regions where the proton-distribution function highly departs from thermal equilibrium are located inside the shear layers, where the KAWs are excited, this suggesting that the distortions of the proton distribution are driven by a resonant interaction of protons with KAW fluctuations. Our results are relevant in configurations where magnetic-field inhomogeneities are present, as, for example, in the solar corona, where the presence of Alfvén waves has been ascertained.

  6. A 1372-element Large Scale Hemispherical Ultrasound Phased Array Transducer for Noninvasive Transcranial Therapy

    NASA Astrophysics Data System (ADS)

    Song, Junho; Hynynen, Kullervo

    2009-04-01

    Noninvasive transcranial therapy using high intensity focused ultrasound transducers has attracted high interest as a promising new modality for the treatments of brain related diseases. We describe the development of a 1372 element large scale hemispherical ultrasound phased array transducer operating at a resonant frequency of 306 kHz. The hemispherical array has a diameter of 31 cm and a 15.5 cm radius of curvature. It is constructed with piezoelectric (PZT-4) tube elements of a 10 mm in diameter, 6 mm in length and 1.4 mm wall thickness. Each element is quasi-air backed by attaching a cork-rubber membrane on the back of the element. The acoustic efficiency of the element is determined to be approximately 50%. The large number of the elements delivers high power ultrasound and offers better beam steering and focusing capability. Comparisons of sound pressure-squared field measurements with theoretical calculations in water show that the array provides good beam steering and tight focusing capability over an efficient volume of approximately 100×100×80 mm3 with nominal focal spot size of approximately 2.3 mm in diameter at -6 dB. We also present its beam steering and focusing capability through an ex vivo human skull by measuring pressure-squared amplitude after phase corrections. These measurements show the same efficient volume range and focal spot sizes at -6 dB as the ones in water without the skull present. These results indicate that the array is sufficient for use in noninvasive transcranial ultrasound therapy.

  7. A 1372-element Large Scale Hemispherical Ultrasound Phased Array Transducer for Noninvasive Transcranial Therapy

    SciTech Connect

    Song, Junho; Hynynen, Kullervo

    2009-04-14

    Noninvasive transcranial therapy using high intensity focused ultrasound transducers has attracted high interest as a promising new modality for the treatments of brain related diseases. We describe the development of a 1372 element large scale hemispherical ultrasound phased array transducer operating at a resonant frequency of 306 kHz. The hemispherical array has a diameter of 31 cm and a 15.5 cm radius of curvature. It is constructed with piezoelectric (PZT-4) tube elements of a 10 mm in diameter, 6 mm in length and 1.4 mm wall thickness. Each element is quasi-air backed by attaching a cork-rubber membrane on the back of the element. The acoustic efficiency of the element is determined to be approximately 50%. The large number of the elements delivers high power ultrasound and offers better beam steering and focusing capability. Comparisons of sound pressure-squared field measurements with theoretical calculations in water show that the array provides good beam steering and tight focusing capability over an efficient volume of approximately 100x100x80 mm{sup 3} with nominal focal spot size of approximately 2.3 mm in diameter at -6 dB. We also present its beam steering and focusing capability through an ex vivo human skull by measuring pressure-squared amplitude after phase corrections. These measurements show the same efficient volume range and focal spot sizes at -6 dB as the ones in water without the skull present. These results indicate that the array is sufficient for use in noninvasive transcranial ultrasound therapy.

  8. KINETIC ALFVÉN WAVE GENERATION BY LARGE-SCALE PHASE MIXING

    SciTech Connect

    Vásconez, C. L.; Pucci, F.; Valentini, F.; Servidio, S.; Malara, F.; Matthaeus, W. H.

    2015-12-10

    One view of the solar wind turbulence is that the observed highly anisotropic fluctuations at spatial scales near the proton inertial length d{sub p} may be considered as kinetic Alfvén waves (KAWs). In the present paper, we show how phase mixing of large-scale parallel-propagating Alfvén waves is an efficient mechanism for the production of KAWs at wavelengths close to d{sub p} and at a large propagation angle with respect to the magnetic field. Magnetohydrodynamic (MHD), Hall magnetohydrodynamic (HMHD), and hybrid Vlasov–Maxwell (HVM) simulations modeling the propagation of Alfvén waves in inhomogeneous plasmas are performed. In the linear regime, the role of dispersive effects is singled out by comparing MHD and HMHD results. Fluctuations produced by phase mixing are identified as KAWs through a comparison of polarization of magnetic fluctuations and wave-group velocity with analytical linear predictions. In the nonlinear regime, a comparison of HMHD and HVM simulations allows us to point out the role of kinetic effects in shaping the proton-distribution function. We observe the generation of temperature anisotropy with respect to the local magnetic field and the production of field-aligned beams. The regions where the proton-distribution function highly departs from thermal equilibrium are located inside the shear layers, where the KAWs are excited, this suggesting that the distortions of the proton distribution are driven by a resonant interaction of protons with KAW fluctuations. Our results are relevant in configurations where magnetic-field inhomogeneities are present, as, for example, in the solar corona, where the presence of Alfvén waves has been ascertained.

  9. Switching of a large anomalous Hall effect between metamagnetic phases of a non-collinear antiferromagnet.

    PubMed

    Sürgers, Christoph; Wolf, Thomas; Adelmann, Peter; Kittler, Wolfram; Fischer, Gerda; Löhneysen, Hilbert V

    2017-02-20

    The anomalous Hall effect (AHE), which in long-range ordered ferromagnets appears as a voltage transverse to the current and usually is proportional to the magnetization, often is believed to be of negligible size in antiferromagnets due to their low uniform magnetization. However, recent experiments and theory have demonstrated that certain antiferromagnets with a non-collinear arrangement of magnetic moments exhibit a sizeable spontaneous AHE at zero field due to a non-vanishing Berry curvature arising from the quantum mechanical phase of the electron's wave functions. Here we show that antiferromagnetic Mn5Si3 single crystals exibit a large AHE which is strongly anisotropic and shows multiple transitions with sign changes at different magnetic fields due to field-induced rearrangements of the magnetic structure despite only tiny variations of the total magnetization. The presence of multiple non-collinear magnetic phases offers the unique possiblity to explore the details of the AHE and the sensitivity of the Hall effect on the details of the magnetic texture.

  10. Highly efficient second harmonic generation in hyperbolic metamaterial slot waveguides with large phase matching tolerance.

    PubMed

    Sun, Yu; Zheng, Zheng; Cheng, Jiangtao; Sun, Guodong; Qiao, Guofu

    2015-03-09

    Highly efficient second harmonic generation (SHG) bridging the mid-infrared (IR) and near-IR wavelengths in a coupled hyperbolic metamaterial waveguide with a nonlinear-polymer-filled nanoscale slot is theoretically investigated. By engineering the geometrical parameters, the collinear phase matching condition is satisfied between the even hybrid modes at the fundamental frequency (3,100 nm) and the second harmonic (1,550 nm). Two modes manifest the great field overlap and the significant field enhancement in the nonlinear integration area (i.e. the slot), which leads to extreme large nonlinear coupling coefficient. For a low pumping power of 100 mW, the device length is as short as 2.19 µm and the normalized conversion efficiency comes up to more than 6.37 × 10(5) W(-1)cm(-2) which outperforms that of the plasmonic-based structures. Moreover, the efficient SHG can be achieved with great phase matching tolerance, i.e., a small theoretical fabrication-error sensitivity to filling ratio and a broad pump bandwidth in a compact device length of 2.19 µm using 100 mW pump. The proposed scheme links the mature near-IR devices to the mid-IR regime and have a great potential for integrated chip-scale all-optical signal processes.

  11. A spectral Phase-Amplitude method for propagating a wave function to large distances

    NASA Astrophysics Data System (ADS)

    Rawitscher, George

    2015-06-01

    The phase and amplitude (Ph-A) of a wave function vary slowly with distance, in contrast to the wave function that can be highly oscillatory. Hence the Ph-A representation of a wave function requires far fewer computational mesh points than the wave function itself. In 1930 Milne presented an equation for the phase and the amplitude functions (which is different from the one developed by Calogero), and in 1962 Seaton and Peach solved these equations iteratively. The objective of the present study is to implement Seaton and Peach's iteration procedure with a spectral Chebyshev expansion method, and at the same time present a non-iterative analytic solution to an approximate version of the iterative equations. The iterations converge rapidly for the case of attractive potentials. Two numerical examples are given: (1) for a potential that decreases with distance as 1 /r3, and (2) a Coulomb potential ∝ 1 / r. In both cases the whole radial range of [0-2000] requires only between 25 and 100 mesh points and the corresponding accuracy is between 10-3 and 10-6. The 0th iteration (which is the WKB approximation) gives an accuracy of 10-2. This spectral method permits one to calculate a wave function out to large distances reliably and economically.

  12. Switching of a large anomalous Hall effect between metamagnetic phases of a non-collinear antiferromagnet

    PubMed Central

    Sürgers, Christoph; Wolf, Thomas; Adelmann, Peter; Kittler, Wolfram; Fischer, Gerda; Löhneysen, Hilbert v.

    2017-01-01

    The anomalous Hall effect (AHE), which in long-range ordered ferromagnets appears as a voltage transverse to the current and usually is proportional to the magnetization, often is believed to be of negligible size in antiferromagnets due to their low uniform magnetization. However, recent experiments and theory have demonstrated that certain antiferromagnets with a non-collinear arrangement of magnetic moments exhibit a sizeable spontaneous AHE at zero field due to a non-vanishing Berry curvature arising from the quantum mechanical phase of the electron’s wave functions. Here we show that antiferromagnetic Mn5Si3 single crystals exibit a large AHE which is strongly anisotropic and shows multiple transitions with sign changes at different magnetic fields due to field-induced rearrangements of the magnetic structure despite only tiny variations of the total magnetization. The presence of multiple non-collinear magnetic phases offers the unique possiblity to explore the details of the AHE and the sensitivity of the Hall effect on the details of the magnetic texture. PMID:28218287

  13. Diffuse large B-cell lymphoma presenting in the leukemic phase.

    PubMed

    Pires, Patricia Puccetti; Kanegae, Marcia Yoshie; Rays, Jairo; Catania, Marcos; Lima, Fabiana Roberto; Noronha, Thiago Rodrigo; Abdo, Andre Neder Ramires; Pereira, Juliana

    2016-01-01

    Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma comprising a heterogeneous group of disorders with variable histological and clinical behavior. Although other lymphomas may present in the leukemic phase more frequently, this appearance is unusually observed among DLBCL cases. Diagnosing lymphoma is not always easy, and the patient's clinical status quite often may hamper invasive procedures for diagnosis pushing the clinician to look for alternatives to reach the nearest possible accurate diagnosis. The authors report the case of a middle-aged man who presented the history of malaise, weight loss, and low-grade fever. The peripheral blood count showed leukocytosis with the presence of blasts and thrombocytopenia. The cytological morphology and immunophenotyping of the peripheral blood and bone marrow aspirate, as well as the bone marrow biopsy accompanied by a thorough immunohistochemical analysis, rendered the diagnosis of DLBCL in the leukemic phase. The patient was prescribed R-CHOP with a favorable outcome. Intra-abdominal lymph node biopsy was avoided because of the patient's critical medical condition. The authors highlight this rare form of presentation of DLBCL as well as the combination of peripheral blood, bone marrow aspirate, and bone marrow biopsy for reaching the diagnosis in cases were a lymph node sample is unavailable for the diagnostic work-up.

  14. Diffuse large B-cell lymphoma presenting in the leukemic phase

    PubMed Central

    Pires, Patricia Puccetti; Rays, Jairo; Catania, Marcos; Lima, Fabiana Roberto; Noronha, Thiago Rodrigo; Abdo, Andre Neder Ramires; Pereira, Juliana

    2016-01-01

    Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma comprising a heterogeneous group of disorders with variable histological and clinical behavior. Although other lymphomas may present in the leukemic phase more frequently, this appearance is unusually observed among DLBCL cases. Diagnosing lymphoma is not always easy, and the patient's clinical status quite often may hamper invasive procedures for diagnosis pushing the clinician to look for alternatives to reach the nearest possible accurate diagnosis. The authors report the case of a middle-aged man who presented the history of malaise, weight loss, and low-grade fever. The peripheral blood count showed leukocytosis with the presence of blasts and thrombocytopenia. The cytological morphology and immunophenotyping of the peripheral blood and bone marrow aspirate, as well as the bone marrow biopsy accompanied by a thorough immunohistochemical analysis, rendered the diagnosis of DLBCL in the leukemic phase. The patient was prescribed R-CHOP with a favorable outcome. Intra-abdominal lymph node biopsy was avoided because of the patient's critical medical condition. The authors highlight this rare form of presentation of DLBCL as well as the combination of peripheral blood, bone marrow aspirate, and bone marrow biopsy for reaching the diagnosis in cases were a lymph node sample is unavailable for the diagnostic work-up. PMID:27284540

  15. From analytical methods to large scale chiral supercritical fluid chromatography using chlorinated chiral stationary phases.

    PubMed

    Wu, Dauh-Rurng; Yip, Shiuhang Henry; Li, Peng; Sun, Dawn; Mathur, Arvind

    2016-02-05

    While traditional non-chlorinated Cellulose- and Amylose-derivatized phases have been used successfully in supercritical fluid chromatography (SFC) to resolve a broad variety of chiral compounds, some chiral pharmaceutical compounds are not well resolved on these traditional chiral stationary phases (CSP) due to the lack of chiral selectivity. Since there are no universal CSP to resolve all chiral compounds, chlorinated CSP can be complementary to the non-chlorinated CSP. Chlorinated CSP such as 4-Chloro-3-methylphenyl-carbamatecellulose (Lux-Cellulose-4), 3-Chloro-4-methylphenyl-carbamatecellulose (Lux-Cellulose-2), 5-Chloro-2-methylphenyl-carbamateamylose (Lux-Amylose-2) and immobilized 3,5-dichlorophenyl-carbamatecellulose (Chiralpak IC) have provided a range of chiral recognition mechanisms which have allowed the authors to successfully achieve chiral SFC resolution on several structurally diverse compounds, which are not well resolved in the non-chlorinated CSP. In addition, chlorinated Lux-Cellulose-4, Chiralpak IC and Lux-Amylose-2 have enabled us to utilize non-alcohol solvents as sample diluents and as co-solvents to significantly improve compound solubility and selectivity. This article will discuss the challenges associated with several SFC applications on both coated and immobilized chlorinated CSP to deliver high-quality drug candidates in large quantity. The use of dichloromethane in both sample preparation and as co-solvent in CO2 to increase sample solubility will be presented in preparative example #2 and #3.

  16. Switching of a large anomalous Hall effect between metamagnetic phases of a non-collinear antiferromagnet

    NASA Astrophysics Data System (ADS)

    Sürgers, Christoph; Wolf, Thomas; Adelmann, Peter; Kittler, Wolfram; Fischer, Gerda; Löhneysen, Hilbert V.

    2017-02-01

    The anomalous Hall effect (AHE), which in long-range ordered ferromagnets appears as a voltage transverse to the current and usually is proportional to the magnetization, often is believed to be of negligible size in antiferromagnets due to their low uniform magnetization. However, recent experiments and theory have demonstrated that certain antiferromagnets with a non-collinear arrangement of magnetic moments exhibit a sizeable spontaneous AHE at zero field due to a non-vanishing Berry curvature arising from the quantum mechanical phase of the electron’s wave functions. Here we show that antiferromagnetic Mn5Si3 single crystals exibit a large AHE which is strongly anisotropic and shows multiple transitions with sign changes at different magnetic fields due to field-induced rearrangements of the magnetic structure despite only tiny variations of the total magnetization. The presence of multiple non-collinear magnetic phases offers the unique possiblity to explore the details of the AHE and the sensitivity of the Hall effect on the details of the magnetic texture.

  17. Synthesizing High-Frequency (1-25 HZ) Regional Phases at Large Distances (>1000 KM) Using Generalized Screen Propagators (GSP)

    DTIC Science & Technology

    2004-09-01

    seismology and earthquake seismology . The generalized screen propagator (GSP) is based on the one-way wave equation and the one-return approximation. The...High-Frequency (1-25 HZ) Regional Phases at Large Distances O (>1000 KM) Using Generalized Screen Propagators (GSP) SApproved for public release...DTRA 01-97-1-0004 Synthesizing High-Freguency (1-25 HZ) Regional Phases at Large Distances (1 > 1000 KM) Using Generalized Screen Propagators (GSP) 5b

  18. Noise Filtering and Signal Calibration in the MicroBooNE LArTPC

    NASA Astrophysics Data System (ADS)

    Joshi, Jyoti; Qian, Xin; MicroBooNE Collaboration Collaboration

    2017-01-01

    In large liquid argon time projection chambers (LArTPCs), TPC signal processing, which recovers the number of ionized electrons arriving at anode wire planes from the raw digitized induction signals, is a crucial step towards automated event reconstruction. The first stage of signal processing is the identification and removal of any excess TPC noise with minimal impact on the true signal. In this talk, first I will describe the characterization and software filtering techniques of various TPC noise observed in the raw digital signal data in MicroBooNE. I will then describe a novel drifted-charge extraction method based on 2D deconvolution technique. These techniques significantly enhance the performance of the induction wire planes in MicroBooNE.

  19. R×B drift momentum spectrometer with high resolution and large phase space acceptance.

    PubMed

    Wang, X; Konrad, G; Abele, H

    2013-02-11

    We propose a new type of momentum spectrometer, which uses the R×B drift effect to disperse the charged particles in a uniformly curved magnetic field, and measures the particles with large phase space acceptance and high resolution. This kind of R×B spectrometer is designed for the momentum analyses of the decay electrons and protons in the PERC (Proton and Electron Radiation Channel) beam station, which provides a strong magnetic field to guide the charged particles in the instrument. Instead of eliminating the guiding field, the R×B spectrometer evolves the field gradually to the analysing field, and the charged particles can be adiabatically transported during the dispersion and detection. The drifts of the particles have similar properties as their dispersion in the normal magnetic spectrometer. Besides, the R×B spectrometer is especially ideal for the measurements of particles with low momenta and large incident angles. We present a design of the R×B spectrometer, which can be used in PERC. For the particles with solid angle smaller than 88 msr, the maximum aberration is below 10(-4). The resolution of the momentum spectra can reach 14.4 keV/c, if the particle position measurements have a resolution of 1 mm.

  20. Large field-of-view tiled grating structures for X-ray phase-contrast imaging

    NASA Astrophysics Data System (ADS)

    Schröter, Tobias J.; Koch, Frieder J.; Meyer, Pascal; Kunka, Danays; Meiser, Jan; Willer, Konstantin; Gromann, Lukas; De Marco, Fabio; Herzen, Julia; Noel, Peter; Yaroshenko, Andre; Hofmann, Andreas; Pfeiffer, Franz; Mohr, Jürgen

    2017-01-01

    X-ray grating-based interferometry promises unique new diagnostic possibilities in medical imaging and materials analysis. To transfer this method from scientific laboratories or small-animal applications to clinical radiography applications, compact setups with a large field of view (FoV) are required. Currently the FoV is limited by the grating area, which is restricted due to the complex manufacturing process. One possibility to increase the FoV is tiling individual grating tiles to create one large area grating mounted on a carrier substrate. We investigate theoretically the accuracy needed for a tiling process in all degrees of freedom by applying a simulation approach. We show how the resulting precision requirements can be met using a custom-built frame for exact positioning. Precise alignment is achieved by comparing the fringe patterns of two neighboring grating tiles in a grating interferometer. With this method, the FoV can be extended to practically any desired length in one dimension. First results of a phase-contrast scanning setup with a full FoV of 384 mm × 24 mm show the suitability of this method.

  1. Phase field approach with anisotropic interface energy and interface stresses: Large strain formulation

    NASA Astrophysics Data System (ADS)

    Levitas, Valery I.; Warren, James A.

    2016-06-01

    A thermodynamically consistent, large-strain, multi-phase field approach (with consequent interface stresses) is generalized for the case with anisotropic interface (gradient) energy (e.g. an energy density that depends both on the magnitude and direction of the gradients in the phase fields). Such a generalization, if done in the "usual" manner, yields a theory that can be shown to be manifestly unphysical. These theories consider the gradient energy as anisotropic in the deformed configuration, and, due to this supposition, several fundamental contradictions arise. First, the Cauchy stress tensor is non-symmetric and, consequently, violates the moment of momentum principle, in essence the Herring (thermodynamic) torque is imparting an unphysical angular momentum to the system. In addition, this non-symmetric stress implies a violation of the principle of material objectivity. These problems in the formulation can be resolved by insisting that the gradient energy is an isotropic function of the gradient of the order parameters in the deformed configuration, but depends on the direction of the gradient of the order parameters (is anisotropic) in the undeformed configuration. We find that for a propagating nonequilibrium interface, the structural part of the interfacial Cauchy stress is symmetric and reduces to a biaxial tension with the magnitude equal to the temperature- and orientation-dependent interface energy. Ginzburg-Landau equations for the evolution of the order parameters and temperature evolution equation, as well as the boundary conditions for the order parameters are derived. Small strain simplifications are presented. Remarkably, this anisotropy yields a first order correction in the Ginzburg-Landau equation for small strains, which has been neglected in prior works. The next strain-related term is third order. For concreteness, specific orientation dependencies of the gradient energy coefficients are examined, using published molecular dynamics

  2. Large-scale calculations of gas phase thermochemistry: Enthalpy of formation, standard entropy, and heat capacity

    NASA Astrophysics Data System (ADS)

    Ghahremanpour, Mohammad M.; van Maaren, Paul J.; Ditz, Jonas C.; Lindh, Roland; van der Spoel, David

    2016-09-01

    Large scale quantum calculations for molar enthalpy of formation (ΔfH0), standard entropy (S0), and heat capacity (CV) are presented. A large data set may help to evaluate quantum thermochemistry tools in order to uncover possible hidden shortcomings and also to find experimental data that might need to be reinvestigated, indeed we list and annotate approximately 200 problematic thermochemistry measurements. Quantum methods systematically underestimate S0 for flexible molecules in the gas phase if only a single (minimum energy) conformation is taken into account. This problem can be tackled in principle by performing thermochemistry calculations for all stable conformations [Zheng et al., Phys. Chem. Chem. Phys. 13, 10885-10907 (2011)], but this is not practical for large molecules. We observe that the deviation of composite quantum thermochemistry recipes from experimental S0 corresponds roughly to the Boltzmann equation (S = RlnΩ), where R is the gas constant and Ω the number of possible conformations. This allows an empirical correction of the calculated entropy for molecules with multiple conformations. With the correction we find an RMSD from experiment of ≈13 J/mol K for 1273 compounds. This paper also provides predictions of ΔfH0, S0, and CV for well over 700 compounds for which no experimental data could be found in the literature. Finally, in order to facilitate the analysis of thermodynamics properties by others we have implemented a new tool obthermo in the OpenBabel program suite [O'Boyle et al., J. Cheminf. 3, 33 (2011)] including a table of reference atomization energy values for popular thermochemistry methods.

  3. MicroBooNE, A Liquid Argon Time Projection Chamber (LArTPC) Neutrino Experiment

    SciTech Connect

    Katori, Teppei

    2011-07-01

    Liquid Argon time projection chamber (LArTPC) is a promising detector technology for future neutrino experiments. MicroBooNE is a upcoming LArTPC neutrino experiment which will be located on-axis of Booster Neutrino Beam (BNB) at Fermilab, USA. The R&D efforts on this detection method and related neutrino interaction measurements are discussed.

  4. Thermodynamically consistent phase field approach to dislocation evolution at small and large strains

    NASA Astrophysics Data System (ADS)

    Levitas, Valery I.; Javanbakht, Mahdi

    2015-09-01

    A thermodynamically consistent, large strain phase field approach to dislocation nucleation and evolution at the nanoscale is developed. Each dislocation is defined by an order parameter, which determines the magnitude of the Burgers vector for the given slip planes and directions. The kinematics is based on the multiplicative decomposition of the deformation gradient into elastic and plastic contributions. The relationship between the rates of the plastic deformation gradient and the order parameters is consistent with phenomenological crystal plasticity. Thermodynamic and stability conditions for homogeneous states are formulated and satisfied by the proper choice of the Helmholtz free energy and the order parameter dependence on the Burgers vector. They allow us to reproduce desired lattice instability conditions and a stress-order parameter curve, as well as to obtain a stress-independent equilibrium Burgers vector and to avoid artificial dissipation during elastic deformation. The Ginzburg-Landau equations are obtained as the linear kinetic relations between the rate of change of the order parameters and the conjugate thermodynamic driving forces. A crystalline energy coefficient for dislocations is defined as a periodic step-wise function of the coordinate along the normal to the slip plane, which provides an energy barrier normal to the slip plane and determines the desired, mesh-independent height of the dislocation bands for any slip system orientation. Gradient energy contains an additional term, which excludes the localization of a dislocation within a height smaller than the prescribed height, but it does not produce artificial interface energy. An additional energy term is introduced that penalizes the interaction of different dislocations at the same point. Non-periodic boundary conditions for dislocations are introduced which include the change of the surface energy due to the exit of dislocations from the crystal. Obtained kinematics, thermodynamics

  5. The costs and effectiveness of large Phase III pre-licensure vaccine clinical trials.

    PubMed

    Black, Steven

    2015-01-01

    Prior to the 1980s, most vaccines were licensed based upon safety and effectiveness studies in several hundred individuals. Beginning with the evaluation of Haemophilus influenzae type b conjugate vaccines, much larger pre-licensure trials became common. The pre-licensure trial for Haemophilus influenzae oligosaccharide conjugate vaccine had more than 60,000 children and that of the seven-valent pneumococcal conjugate vaccine included almost 38,000 children. Although trial sizes for both of these studies were driven by the sample size required to demonstrate efficacy, the sample size requirements for safety evaluations of other vaccines have subsequently increased. With the demonstration of an increased risk of intussusception following the Rotashield brand rotavirus vaccine, this trend has continued. However, routinely requiring safety studies of 20,000-50,000 or more participants has two major downsides. First, the cost of performing large safety trials routinely prior to licensure of a vaccine is very large, with some estimates as high at US$200 million euros for one vaccine. This high financial cost engenders an opportunity cost whereby the number of vaccines that a company is willing or able to develop to meet public health needs becomes limited by this financial barrier. The second downside is that in the pre-licensure setting, such studies are very time consuming and delay the availability of a beneficial vaccine substantially. One might argue that in some situations, this financial commitment is warranted such as for evaluations of the risk of intussusception following newer rotavirus vaccines. However, it must be noted that while an increased risk of intussusception was not identified in large pre-licensure studies, in post marketing evaluations an increased risk of this outcome has been identified. Thus, even the extensive pre-licensure evaluations conducted did not identify an associated risk. The limitations of large Phase III trials have also been

  6. Large topological Hall effect in the non-collinear phase of an antiferromagnet.

    PubMed

    Sürgers, Christoph; Fischer, Gerda; Winkel, Patrick; Löhneysen, Hilbert V

    2014-03-05

    Non-trivial spin arrangements in magnetic materials give rise to the topological Hall effect observed in compounds with a non-centrosymmetric cubic structure hosting a skyrmion lattice, in double-exchange ferromagnets and magnetically frustrated systems. The topological Hall effect has been proposed to appear also in presence of non-coplanar spin configurations and thus might occur in an antiferromagnetic material with a highly non-collinear and non-coplanar spin structure. Particularly interesting is a material where the non-collinearity develops not immediately at the onset of antiferromagnetic order but deep in the antiferromagnetic phase. This unusual situation arises in non-cubic antiferromagnetic Mn5Si3. Here we show that a large topological Hall effect develops well below the Néel temperature as soon as the spin arrangement changes from collinear to non-collinear with decreasing temperature. We further demonstrate that the effect is not observed when the material is turned ferromagnetic by carbon doping without changing its crystal structure.

  7. THREE-POINT PHASE CORRELATIONS: A NEW MEASURE OF NONLINEAR LARGE-SCALE STRUCTURE

    SciTech Connect

    Wolstenhulme, Richard; Bonvin, Camille; Obreschkow, Danail

    2015-05-10

    We derive an analytical expression for a novel large-scale structure observable: the line correlation function. The line correlation function, which is constructed from the three-point correlation function of the phase of the density field, is a robust statistical measure allowing the extraction of information in the nonlinear and non-Gaussian regime. We show that, in perturbation theory, the line correlation is sensitive to the coupling kernel F{sub 2}, which governs the nonlinear gravitational evolution of the density field. We compare our analytical expression with results from numerical simulations and find a 1σ agreement for separations r ≳ 30 h{sup −1} Mpc. Fitting formulae for the power spectrum and the nonlinear coupling kernel at small scales allow us to extend our prediction into the strongly nonlinear regime, where we find a 1σ agreement with the simulations for r ≳ 2 h{sup −1} Mpc. We discuss the advantages of the line correlation relative to standard statistical measures like the bispectrum. Unlike the latter, the line correlation is independent of the bias, in the regime where the bias is local and linear. Furthermore, the variance of the line correlation is independent of the Gaussian variance on the modulus of the density field. This suggests that the line correlation can probe more precisely the nonlinear regime of gravity, with less contamination from the power spectrum variance.

  8. Automated solid-phase extraction approaches for large scale biomonitoring studies.

    PubMed

    Kuklenyik, Zsuzsanna; Ye, Xiaoyun; Needham, Larry L; Calafat, Antonia M

    2009-01-01

    The main value in measuring environmental chemicals in biological specimens (i.e., biomonitoring) is the ability to minimize risk assessment uncertainties. The collection of biomonitoring data for risk assessment requires the analysis of a statistically significant number of samples from subjects with a significant prevalence of detectable internal dose levels. This paper addresses the practical laboratory challenges that arise from these statistical requirements: development of high throughput techniques that can handle, with high accuracy and precision, a large number of samples and can do a trace level analysis of multiple and diverse environmental chemicals (i.e., analytes). We review here examples of high throughput, automated solid-phase extraction methods developed in our laboratory for biomonitoring of analytes with representative hydrophobic properties and for typical biomonitoring matrices. We discuss key aspects of sample preparation, column, and solvent selection for off- and online extractions, and the so-called nuts-and-bolts of online column-switching systems necessary for developing-with minimal sample handling-rugged, automated methods.

  9. Two-dimensional phase contrast imaging for local turbulence measurements in large helical device (invited)

    SciTech Connect

    Tanaka, K.; Michael, C. A.; Kawahata, K.; Akiyama, T.; Tokuzawa, T.; Vyacheslavov, L. N.; Sanin, A. L.; Okajima, S.

    2008-10-15

    Two-dimensional phase contrast imaging (2D) installed on the large helical device (LHD) is a unique diagnostic for local turbulence measurements. A 10.6 {mu}m infrared CO{sub 2} laser and 6x8 channel HgCdTe 2D detector are used. The length of the scattering volume is larger than plasma size. However, the asymmetry of turbulence structure with respect to the magnetic field and magnetic shear make local turbulence measurements possible. From a 2D image of the integrated fluctuations, the spatial cross-correlation function was estimated using time domain correlation analysis, then, the integrated 2D k-spectrum is obtained using maximum entropy method. The 2D k-spectrum is converted from Cartesian coordinates to cylindrical coordinates. Finally, the angle in cylindrical coordinate is converted to flux surface labels. The fluctuation profile over almost the entire plasma diameter can be obtained at a single moment. The measurable k-region can be varied by adjusting the detection optics. Presently, k=0.1-1.0 mm{sup -1} can be measured which is expected region of ion temperature gradient modes and trapped electron mode in LHD. The spatial resolution is 10%-50% of the minor radius.

  10. Large-scale continuum random-phase approximation predictions of dipole strength for astrophysical applications

    NASA Astrophysics Data System (ADS)

    Daoutidis, I.; Goriely, S.

    2012-09-01

    Large-scale calculations of the E1 strength are performed within the random phase approximation (RPA) based on the relativistic point-coupling mean field approach in order to derive the radiative neutron capture cross sections for all nuclei of astrophysical interest. While the coupling to the single-particle continuum is taken into account in an explicit and self-consistent way, additional corrections like the coupling to complex configurations and the temperature and deformation effects are included in a phenomenological way to account for a complete description of the nuclear dynamical problem. It is shown that the resulting E1-strength function based on the PCF1 force is in close agreement with photoabsorption data as well as the available experimental E1 strength data at low energies. For neutron-rich nuclei, as well as light neutron-deficient nuclei, a low-lying so-called pygmy resonance is found systematically in the 5-10 MeV region. The corresponding strength can reach 10% of the giant dipole strength in the neutron-rich region and about 5% in the neutron-deficient region, and is found to be reduced in the vicinity of the shell closures. Finally, the neutron capture reaction rates of neutron-rich nuclei is found to be about 2-5 times larger than those predicted on the basis of the nonrelativistic RPA calculation and about a factor 50 larger than obtained with traditional Lorentzian-type approaches.

  11. Development of a large mosaic volume phase holographic (VPH) grating for APOGEE

    NASA Astrophysics Data System (ADS)

    Arns, James; Wilson, John C.; Skrutskie, Mike; Smee, Steve; Barkhouser, Robert; Eisenstein, Daniel; Gunn, Jim; Hearty, Fred; Harding, Al; Maseman, Paul; Holtzman, Jon; Schiavon, Ricardo; Gillespie, Bruce; Majewski, Steven

    2010-07-01

    Volume phase holographic (VPH) gratings are increasingly being used as diffractive elements in astronomical instruments due to their potential for very high peak diffraction efficiencies and the possibility of a compact instrument design when the gratings are used in transmission. Historically, VPH grating (VPHG) sizes have been limited by the size of manufacturer's holographic recording optics. We report on the design, specification and fabrication of a large, 290 mm × 475 mm elliptically-shaped, mosaic VPHG for the Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectrograph. This high-resolution near-infrared multi-object spectrograph is in construction for the Sloan Digital Sky Survey III (SDSS III). The 1008.6 lines/mm VPHG was designed for optimized performance over a wavelength range from 1.5 to 1.7 μm. A step-and-repeat exposure method was chosen to fabricate a three-segment mosaic on a 305 mm × 508 mm monolithic fused-silica substrate. Specification considerations imposed on the VPHG to assure the mosaic construction will satisfy the end use requirements are discussed. Production issues and test results of the mosaic VPHG are discussed.

  12. Terbium-Doped VO2 Thin Films: Reduced Phase Transition Temperature and Largely Enhanced Luminous Transmittance.

    PubMed

    Wang, Ning; Duchamp, Martial; Dunin-Borkowski, Rafal E; Liu, Shiyu; Zeng, XianTing; Cao, Xun; Long, Yi

    2016-01-26

    Vanadium dioxide (VO2) is a well-known thermochromic material with large IR modulating ability, promising for energy-saving smart windows. The main drawbacks of VO2 are its high phase transition temperature (τ(c) = 68°C), low luminous transmission (T(lum)), and weak solar modulating ability (ΔT(sol)). In this paper, the terbium cation (Tb(3+)) doping was first reported to reduce τ(c) and increase T(lum) of VO2 thin films. Compared with pristine VO2, 2 at. % doping level gives both enhanced T(lum) and ΔT(sol) from 45.8% to 54.0% and 7.7% to 8.3%, respectively. The T(lum) increases with continuous Tb(3+) doping and reaches 79.4% at 6 at. % doping level, representing ∼73.4% relative increment compared with pure VO2. This has surpassed the best reported doped VO2 thin films. The enhanced thermochromic properties is meaningful for smart window applications of VO2 materials.

  13. Synthesis and characterization of large-grain solid-phase crystallized polycrystalline silicon thin films

    SciTech Connect

    Kumar, Avishek E-mail: dalapatig@imre.a-star.edu.sg; Law, Felix; Widenborg, Per I.; Dalapati, Goutam K. E-mail: dalapatig@imre.a-star.edu.sg; Subramanian, Gomathy S.; Tan, Hui R.; Aberle, Armin G.

    2014-11-01

    n-type polycrystalline silicon (poly-Si) films with very large grains, exceeding 30 μm in width, and with high Hall mobility of about 71.5 cm{sup 2}/V s are successfully prepared by the solid-phase crystallization technique on glass through the control of the PH{sub 3} (2% in H{sub 2})/SiH{sub 4} gas flow ratio. The effect of this gas flow ratio on the electronic and structural quality of the n-type poly-Si thin film is systematically investigated using Hall effect measurements, Raman microscopy, and electron backscatter diffraction (EBSD), respectively. The poly-Si grains are found to be randomly oriented, whereby the average area weighted grain size is found to increase from 4.3 to 18 μm with increase of the PH{sub 3} (2% in H{sub 2})/SiH{sub 4} gas flow ratio. The stress in the poly-Si thin films is found to increase above 900 MPa when the PH{sub 3} (2% in H{sub 2})/SiH{sub 4} gas flow ratio is increased from 0.025 to 0.45. Finally, high-resolution transmission electron microscopy, high angle annular dark field-scanning tunneling microscopy, and EBSD are used to identify the defects and dislocations caused by the stress in the fabricated poly-Si films.

  14. Steam-water two-phase flow in large diameter vertical piping at high pressures and temperatures

    SciTech Connect

    Hasanein, H.A.; Kawaji, Masahiro; Chan, A.M.C.; Yoshioka, Yuzuru

    1996-08-01

    No information on steam/water two-phase flow behavior in large diameter pipes (10 inch or larger) at elevated pressures is available in the open literature. However, there are many applications, in the nuclear, chemical and petroleum industries among others where two-phase flows in large diameter pipes at elevated pressures and temperatures are encountered routinely or under accident scenarios. Experimental data on steam-water two-phase flow in a large diameter (20 inch, 50.08 cm I.D.) vertical pipe at elevated pressures and temperatures (2.8 MPa/230 C--6.4 MPa/280 C) have been obtained. Void fraction, two-phase mass flux, phase and velocity distributions as well as pressure drop along the test pipe have been measured using the Ontario Hydro Technologies (OHT) Pump Test Loop. The void fraction distributions were found to be axially symmetric and nearly flat over a wide range of two-phase flow conditions. The two-phase flow regime could be inferred from the dynamic void fluctuations data. For the 280 C tests, the flow was found to be relatively stable with bubbly flow at low average void fractions and churn turbulent or wispy-annular flow at higher void fractions. At 230 C, the flow became rather oscillatory and slugging was suspected at relatively low voids. It has also been found that the average void fractions in the test section can be determined reasonably accurately using the axial pressure drop data.

  15. Extremely large anisotropic transport caused by electronic phase separation in Ti-doped Ca3Ru2O7

    NASA Astrophysics Data System (ADS)

    Peng, Jin; Liu, J. Y.; Gu, Xiaomin; Zhou, Guotai; Wang, Wei; Hu, J.; Zhang, F. M.; Wu, X. S.

    2016-06-01

    In this paper, we reported an extremely large out-of-plane/in-plane anisotropic transport ({ρc}/{ρab} ~ 109) in double layer ruthenates. The mechanism that may be responsible for this phenomenon is also explored here. Distinct from previously well studied layered materials which show large out-of-plane/in-plane electronic anisotropy (103-106), the Ti-doped Ca3Ru2O7 single crystals not only form quasi-2D layered structure, but also show phase separation within the layers. We found that Ti doping in Ca3Ru2O7 induced electronic phase separation between the insulating phase and weak localized phase. The ratio of these two phases is very sensitive to the Ti concentration. At typical concentration, the weak localized phase may form a channel on the background of the insulating phase within the ab plane. However, the small volume of weak localized phase makes it less likely to overlap in different layers. This results in a much larger electronic anisotropy ratio than pristine compound Ca3Ru2O7. This new mechanism provides a route for further increase electronic anisotropy, which will remarkably reduce current leak and power consumption in electronic devices.

  16. Magmatic history and parental melt composition of olivine-phyric shergottite LAR 06319: Importance of magmatic degassing and olivine antecrysts in Martian magmatism

    NASA Astrophysics Data System (ADS)

    Balta, J. Brian; Sanborn, Matthew; McSween, Harry Y.; Wadhwa, Meenakshi

    2013-08-01

    Several olivine-phyric shergottites contain enough olivine that they could conceivably represent the products of closed-system crystallization of primary melts derived from partial melting of the Martian mantle. Larkman Nunatak (LAR) 06319 has been suggested to represent a close approach to a Martian primary liquid composition based on approximate equilibrium between its olivine and groundmass. To better understand the olivine-melt relationship and the evolution of this meteorite, we report the results of new petrographic and chemical analyses. We find that olivine megacryst cores are generally not in equilibrium with the groundmass, but rather have been homogenized by diffusion to Mg# 72. We have identified two unique grain types: an olivine glomerocryst and an olivine grain preserving a primary magmatic boundary that constrains the time scale of eruption to be on the order of hours. We also report the presence of trace oxide phases and phosphate compositions that suggest that the melt contained approximately 1.1% H2O and lost volatiles during cooling, also associated with an increase in oxygen fugacity upon degassing. We additionally report in situ rare earth element measurements of the various mineral phases in LAR 06319. Based on these reported trace element abundances, we estimate the oxygen fugacity in the LAR 06319 parent melt early in its crystallization sequence (i.e., at the time of crystallization of the low-Ca and high-Ca pyroxenes), the rare earth element composition of the parent melt, and those of melts in equilibrium with later formed phases. We suggest that LAR 06319 represents the product of closed-system crystallization within a shallow magma chamber, with additional olivine accumulated from a cumulate pile. We infer that the olivine megacrysts are antecrysts, derived from a single magma chamber, but not directly related to the host magma, and suggest that mixing of antecrysts within magma chambers may be a common process in Martian magmatic

  17. Phases of QCD from Small to Large Nf:. (Some) Lattice Results

    NASA Astrophysics Data System (ADS)

    Deuzeman, A.; Pallante, E.; Lombardo, M. P.

    2011-01-01

    We analyze the phases of strong interactions in the space of the flavor number Nf, bare coupling gL, and temperature T by lattice MonteCarlo simulations for two and three unrooted staggered flavors, corresponding to eight and twelve continuum flavors, respectively. We observe a Coulomb-like phase at intermediate lattice couplings which we interpret as the avatar of a continuum conformal theory for Nf = 12. We comment on the possible occurrence of an UVFP associated with the bulk phase transition between the strong coupling lattice phase and the Coulomb-like phase.

  18. Trajectories of electrons with large longitudinal momenta in the phase plane during surfatron acceleration by an electromagnetic wave

    SciTech Connect

    Mkrtichyan, G. S.

    2015-07-15

    The trajectories of electrons with large longitudinal momenta in the phase plane in the course of their surfatron acceleration by an electromagnetic wave propagating in space plasma across the external magnetic field are analyzed. Electrons with large longitudinal momenta are trapped immediately if the initial wave phase Ψ(0) on the particle trajectory is positive. For negative values of Ψ(0), no electrons trapping by the wave is observed over the available computational times. According to numerical calculations, the trajectories of trapped particles in the phase plane have a singular point of the stable focus type and the behavior of the trajectory corresponds to the motion in a complex nonstationary effective potential well. For some initial phases, electrons are confined in the region of the accelerating electric field for relatively short time, the energy gain being about 50–130% and more.

  19. Investigation of the Seismic Nucleation Phase of Large Earthquakes Using Broadband Teleseismic Data

    NASA Astrophysics Data System (ADS)

    Burkhart, Eryn Therese

    The dynamic motion of an earthquake begins abruptly, but is often initiated by a short interval of weak motion called the seismic nucleation phase (SNP). Ellsworth and Beroza [1995, 1996] concluded that the SNP was detectable in near-source records of 48 earthquakes with moment magnitude (Mw), ranging from 1.1 to 8.1. They found that the SNP accounted for approximately 0.5% of the total moment and 1/6 of the duration of the earthquake. Ji et al [2010] investigated the SNP of 19 earthquakes with Mw greater than 8.0 using teleseismic broadband data. This study concluded that roughly half of the earthquakes had detectable SNPs, inconsistent with the findings of Ellsworth and Beroza [1995]. Here 69 earthquakes of Mw 7.5-8.0 from 1994 to 2011 are further examined. The SNP is clearly detectable using teleseismic data in 32 events, with 35 events showing no nucleation phase, and 2 events had insufficient data to perform stacking, consistent with the previous analysis. Our study also reveals that the percentage of the SNP events is correlated with the focal mechanism and hypocenter depths. Strike-slip earthquakes are more likely to exhibit a clear SNP than normal or thrust earthquakes. Eleven of 14 strike-slip earthquakes (78.6%) have detectable NSPs. In contrast, only 16 of 40 (40%) thrust earthquakes have detectable SNPs. This percentage also became smaller for deep events (33% for events with hypocenter depth>250 km). To understand why certain thrust earthquakes have a visible SNP, we examined the sediment thickness, age, and angle of the subducting plate of all thrust earthquakes in the study. We found that thrust events with shallow (600 m) on the subducting plate tend to have clear SNPs. If the SNP can be better understood in the future, it may help seismologists better understand the rupture dynamics of large earthquakes. Potential applications of this work could attempt to predict the magnitude of an earthquake seconds before it begins by measuring the SNP, vastly

  20. The massive fermion phase for the U(N) Chern-Simons gauge theory in D=3 at large N

    DOE PAGES

    Bardeen, William A.

    2014-10-07

    We explore the phase structure of fermions in the U(N) Chern-Simons Gauge theory in three dimensions using the large N limit where N is the number of colors and the fermions are taken to be in the fundamental representation of the U(N) gauge group. In the large N limit, the theory retains its classical conformal behavior and considerable attention has been paid to possible AdS/CFT dualities of the theory in the conformal phase. In this paper we present a solution for the massive phase of the fermion theory that is exact to the leading order of ‘t Hooft’s large Nmore » expansion. We present evidence for the spontaneous breaking of the exact scale symmetry and analyze the properties of the dilaton that appears as the Goldstone boson of scale symmetry breaking.« less

  1. The massive fermion phase for the U(N) Chern-Simons gauge theory in D=3 at large N

    SciTech Connect

    Bardeen, William A.

    2014-10-07

    We explore the phase structure of fermions in the U(N) Chern-Simons Gauge theory in three dimensions using the large N limit where N is the number of colors and the fermions are taken to be in the fundamental representation of the U(N) gauge group. In the large N limit, the theory retains its classical conformal behavior and considerable attention has been paid to possible AdS/CFT dualities of the theory in the conformal phase. In this paper we present a solution for the massive phase of the fermion theory that is exact to the leading order of ‘t Hooft’s large N expansion. We present evidence for the spontaneous breaking of the exact scale symmetry and analyze the properties of the dilaton that appears as the Goldstone boson of scale symmetry breaking.

  2. Phase-Locked Loop For Measurement Of Small And Large Delays

    NASA Technical Reports Server (NTRS)

    Froggatt, Mark

    1995-01-01

    Electronic signal-generating and processing subsystem of ultrasonic inspection or measurement system consists mainly of variable-and-fixed-frequency, pulsed phase-locked loop (VFFPPLL) measuring phase shifts from 0 degrees to more than 360 degrees with accurancy of 0.112 degrees. VFFPPLL measures phase shifts between transmitted ultrasonic toneburst and its echo, thereby measuring ultrasonic-propagation delay. Used to determine strain in bolt or to track irregular surface of specimen being inspected ultrasonically.

  3. A Role of Phase-Resetting in Coordinating Large Scale Neural Networks During Attention and Goal-Directed Behavior

    PubMed Central

    Voloh, Benjamin; Womelsdorf, Thilo

    2016-01-01

    Short periods of oscillatory activation are ubiquitous signatures of neural circuits. A broad range of studies documents not only their circuit origins, but also a fundamental role for oscillatory activity in coordinating information transfer during goal directed behavior. Recent studies suggest that resetting the phase of ongoing oscillatory activity to endogenous or exogenous cues facilitates coordinated information transfer within circuits and between distributed brain areas. Here, we review evidence that pinpoints phase resetting as a critical marker of dynamic state changes of functional networks. Phase resets: (1) set a “neural context” in terms of narrow band frequencies that uniquely characterizes the activated circuits; (2) impose coherent low frequency phases to which high frequency activations can synchronize, identifiable as cross-frequency correlations across large anatomical distances; (3) are critical for neural coding models that depend on phase, increasing the informational content of neural representations; and (4) likely originate from the dynamics of canonical E-I circuits that are anatomically ubiquitous. These multiple signatures of phase resets are directly linked to enhanced information transfer and behavioral success. We survey how phase resets re-organize oscillations in diverse task contexts, including sensory perception, attentional stimulus selection, cross-modal integration, Pavlovian conditioning, and spatial navigation. The evidence we consider suggests that phase-resets can drive changes in neural excitability, ensemble organization, functional networks, and ultimately, overt behavior. PMID:27013986

  4. Delayed sleep phase syndrome in adolescents: prevalence and correlates in a large population based study

    PubMed Central

    2013-01-01

    Background The aims of this study were to estimate the prevalence of Delayed Sleep Phase Syndrome (DSPS) in adolescence, and to examine the association to insomnia and school non-attendance. Methods Data stem from a large population based study in Hordaland County in Norway conducted in 2012, the ung@hordaland study. In all, 10,220 adolescents aged 16–18 years (54% girls) provided self-reported data on a range of sleep parameters: DSPS was defined according to the International Classification of Sleep Disorders, Revised (ICSD-R) criteria, while insomnia was defined according to the Quantitative Criteria for Insomnia. Other sleep parameters included time in bed, sleep duration, sleep efficiency, oversleeping, sleep onset latency, wake after sleep onset, subjective sleep need, sleep deficiency, sleepiness and tiredness. Sleep data were calculated separately for weekdays and weekends. Data on school non-attendance were provided by official registers. Results The prevalence of DSPS was 3.3%, and significantly higher among girls (3.7%) than boys (2.7%). There was a strong overlap between DSPS and insomnia, with more than half of the adolescents with DSPS also meeting the criteria for insomnia (53.8% for boys and 57.1% for girls). Adolescents with DSPS had significantly higher odds ratios (OR) of non-attendance at school. After adjusting for sociodeographical factors, insomnia and depression, the adjusted ORs for days of non-attendance were OR = 3.22 (95% CI: 1.94-5.34) for boys and OR = 1.87 (95% CI: 1.25-2.80) for girls. A similar effect was found for hours of non-attendance for boys, with an adjusted OR = 3.05 (95% CI: 1.89-4.92). The effect for girls was no longer significant after full adjustment (OR =1.48 [95% CI: 0.94-2.32]). Conclusions This is one of the first studies to estimate the prevalence of DSPS in adolescents. The high prevalence of DSPS, and overlap with insomnia, in combination with the odds of school non-attendance, suggest that a broad

  5. Alemtuzumab in T-cell large granular lymphocytic leukaemia: a phase 2 study

    PubMed Central

    Dumitriu, Bogdan; Ito, Sawa; Feng, Xingmin; Stephens, Nicole; Yunce, Muharrem; Kajigaya, Sachiko; Melenhorst, Joseph J.; Rios, Olga; Scheinberg, Priscila; Chinian, Fariba; Keyvanfar, Keyvan; Battiwalla, Minoo; Wu, Colin O.; Maric, Irina; Xi, Liqiang; Raffeld, Mark; Muranski, Pawel; Townsley, Danielle M.; Young, Neal S.; Barrett, Austin John; Scheinberg, Phillip

    2016-01-01

    Background T-cell large granular lymphocytic leukemia (T-LGL) is a lymphoproliferative disease presenting with immune-mediated cytopenias and characterized by clonal expansion of cytotoxic CD3+CD8+ lymphocytes. Methotrexate, cyclosporine, or cyclophosphamide improve cytopenias in 50% of patients as first therapy, but the activity of an anti-CD52 monoclonal antibody, alemtuzumab, is not defined in T-LGL. Methods Twenty-five consecutive subjects with T-LGL were enrolled from October 2006 to March 2015 at the National Institutes of Health (www.clinicaltrials.gov-NCT00345345). Alemtuzumab was administered at 10 mg/day intravenously for 10 days. The primary endpoint was haematologic response at 3 months. Analysis was intention to treat. Here we report the protocol specified interim benchmark of a phase II clinical trial using alemtuzumab in T-LGL. Findings In this heterogeneous, previously treated cohort, 14/25 (56%; 95% CI, 37–73%) subjects had a haematological response at 3 months. In T-LGL cases not associated with myelodysplasia or marrow transplantation, the response rate was 14/19 (74%; 95% CI, 51–86%). First dose infusion reactions were common which improved with symptomatic therapy. EBV and CMV reactivations were common and subclinical. In only 2 patients pre-emptive anti-CMV therapy was instituted. There were no cases of EBV or CMV disease. Alemtuzumab induced sustained reduction of absolute clonal population of T-cytotoxic lymphocytes, as identified by TCRBV-receptor phenotype, but the abnormal clone serendipitously persisted in responders. STAT3 mutations in the SH2 domain, identified in ten subjects, did not correlate with response. When compared with healthy volunteers, T-LGL subjects showed a distinct plasma cytokine and JAK-STAT signature prior to treatment, but neither correlated to response. Interpretation This is the largest and only prospective cohort of T-LGL subjects treated with alemtuzumab yet reported. The high activity with a single course

  6. Phasing the Very Large Array on Galileo in the presence of Jupiter's strong radio emission

    NASA Technical Reports Server (NTRS)

    Ulvestad, J. S.

    1991-01-01

    Work is in progress to determine the feasibility of using the Very Large Array (VLA) radio telescope to receive telemetry from Galileo during its close encounter with Io on 7 Dec. 1995. The VLA was used previously to receive telemetry from Voyager 2 at Neptune. However, Jupiter's strong radio emission is an additional complication in the case of the Galileo encounter. This article analyzes the effect of Jupiter's radio emission on the phase-adjustment procedure ('autophasing') used to maintain coherence among the 27 VLA antennas. Results of an experiment designed to mimic the Io encounter are presented. As expected, Jupiter's strong radio emission has a considerable effect on the autophasing procedure. A simple emission model is found to give a good approximation to the fringe-visibility plots derived from the VLA data, and that successful model is used to estimate the VLA's ability to autophase on Galileo during the Io encounter. The effect of Jupiter should be small for projected baselines longer than approximately 800 m and completely negligible for projected baselines longer than approximately 1.1 km. The most extended configuration of the VLA (the A configuration) probably can be used successfully for telemetry reception during the Io encounter. Further analysis and testing of the effect of correlated noise from Jupiter is necessary before a final decision can be made about the feasibility of using the second largest (B) configuration of the VLA for reception of Galileo telemetry. Use of the B configuration could simplify the upgrades needed to support the Io encounter. Tests to help choose the preferred VLA configuration could be performed by using the VLA to observe the Magellan spacecraft at Venus during Jul. and Oct. 1991. Examination of the effects of planet noise on the VLA have implications beyond the use of that telescope for supporting the Io encounter. The effects of planet radio emission on spacecraft data received by antenna arrays are relevant to

  7. Appearance of large crystalline domains in VO{sub 2} films grown on sapphire (001) and their phase transition characteristics

    SciTech Connect

    Azhan, Nurul Hanis; Su, Kui; Okimura, Kunio; Zaghrioui, Mustapha; Sakai, Joe

    2015-06-28

    We report the first observation of large crystalline domains of several μm-size in VO{sub 2} films deposited on Al{sub 2}O{sub 3} (001) substrates by rf-biased reactive sputtering technique. The large crystalline domains, dominated with random in-plane oriented growth of (011){sub M1}-orientation, appear only under adequate substrate biasing, such as 10 W, while most biasing conditions result in conventional nanosized grains of highly oriented (010){sub M1}-orientation. Two temperature-controlled analyses, x-ray diffraction and micro-Raman spectroscopy, have revealed that some parts of large crystalline domains undergo intermediate monoclinic (M2) phase during the thermally-induced structural phase transition from monoclinic (M1) to rutile-tetragonal (R) phase. As an effect of the appearance of large crystalline domains, the film showed in-plane tensile stress, resulting in high T{sub IMT} of 69 °C due to the elongation of the V-V distance in its low-temperature monoclinic phase.

  8. Phased array feed design technology for Large Aperture Microwave Radiometer (LAMR) Earth observations

    NASA Technical Reports Server (NTRS)

    Schuman, H. K.

    1992-01-01

    An assessment of the potential and limitations of phased array antennas in space-based geophysical precision radiometry is described. Mathematical models exhibiting the dependence of system and scene temperatures and system sensitivity on phased array antenna parameters and components such as phase shifters and low noise amplifiers (LNA) are developed. Emphasis is given to minimum noise temperature designs wherein the LNA's are located at the array level, one per element or subarray. Two types of combiners are considered: array lenses (space feeds) and corporate networks. The result of a survey of suitable components and devices is described. The data obtained from that survey are used in conjunction with the mathematical models to yield an assessment of effective array antenna noise temperature for representative geostationary and low Earth orbit systems. Practical methods of calibrating a space-based, phased array radiometer are briefly addressed as well.

  9. LARS Artificial Ligament Versus ABC Purely Polyester Ligament for Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Iliadis, Dimitrios Ph.; Bourlos, Dimitrios N.; Mastrokalos, Dimitrios S.; Chronopoulos, Efstathios; Babis, George C.

    2016-01-01

    Background: Graft choice for anterior cruciate ligament (ACL) reconstruction is of critical importance. Various grafts have been used so far, with autografts long considered the optimal solution for the treatment of ACL-deficient knees. Limited data are available on the long-term survivorship of synthetic grafts. Purpose: To compare the functional outcome and survivorship of ACL reconstructions performed using the LARS (ligament augmentation and reconstruction system) ligament and the ABC (active biosynthetic composite) purely polyester ligament. Study Design: Case series; Level of evidence, 4. Methods: The results of 72 patients who underwent primary arthroscopic ACL reconstruction with the LARS ligament and 31 cases with an ABC purely polyester ligament were reviewed. The mean follow-up periods for the LARS and ABC groups were 9.5 and 5.1 years, respectively. A survivorship analysis of the 2 synthetic grafts was performed using the Kaplan-Meier method with a log-rank test (Mantel-Cox, 95% CI). Lysholm, Tegner activity, Knee injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC) scores as well as laxity measurements obtained using a KT-1000 arthrometer were recorded for all intact grafts, and a Mann-Whitney U test was used for comparison reasons. Results: The rupture rates for LARS and ABC grafts were 31% (95% CI, 20%-42%) and 42% (95% CI, 25%-59%), respectively. For intact grafts, the mean Lysholm score was good for both groups (90 for the LARS group and 89 for the ABC group), with the majority of patients returning to their preinjury level of activities, and the mean IKDC score was 90 for the LARS group and 86 for the ABC group. Conclusion: The rupture rates of both LARS and ABC grafts were both high. However, the LARS ligament provided significantly better survivorship compared with the ABC ligament at short- to midterm follow-up (95% CI). PMID:27453894

  10. Role of PTPase LAR in EGF Receptor in the Mammary Gland

    DTIC Science & Technology

    2003-06-01

    development and tumorigenesis through negative modulation of EGFR signal transduction. In year 2, we demonstrated that LAR expression is regulated by...blocks the cell cycle. The central role of Akt regulation in this pathway is confirmed by recapitulating the effect with an adenovirus-mediated...epithelium. The experimental question to be asked is: Does LAR regulate pregnancy-dependent mammary gland maturation? This is very relevant to the hypothesis

  11. Large-scale and uniform preparation of pure-phase wurtzite GaAs NWs on non-crystalline substrates.

    PubMed

    Han, Ning; Hou, Jared J; Wang, Fengyun; Yip, Senpo; Lin, Hao; Fang, Ming; Xiu, Fei; Shi, Xiaoling; Hung, Takfu; Ho, Johnny C

    2012-11-21

    One of the challenges to prepare high-performance and uniform III-V semiconductor nanowires (NWs) is to control the crystal structure in large-scale. A mixed crystal phase is usually observed due to the small surface energy difference between the cubic zincblende (ZB) and hexagonal wurtzite (WZ) structures, especially on non-crystalline substrates. Here, utilizing Au film as thin as 0.1 nm as the catalyst, we successfully demonstrate the large-scale synthesis of pure-phase WZ GaAs NWs on amorphous SiO2/Si substrates. The obtained NWs are smooth, uniform with a high aspect ratio, and have a narrow diameter distribution of 9.5 ± 1.4 nm. The WZ structure is verified by crystallographic investigations, and the corresponding electronic bandgap is also determined to be approximately 1.62 eV by the reflectance measurement. The formation mechanism of WZ NWs is mainly attributed to the ultra-small NW diameter and the very narrow diameter distribution associated, where the WZ phase is more thermodynamically stable compared to the ZB structure. After configured as NW field-effect-transistors, a high ION/IOFF ratio of 104 - 105 is obtained, operating in the enhancement device mode. The preparation technology and good uniform performance here have illustrated a great promise for the large-scale synthesis of pure phase NWs for electronic and optical applications.

  12. Definition of technology development missions for early space stations. Large space structures, phase 2, midterm review

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The large space structures technology development missions to be performed on an early manned space station was studied and defined and the resources needed and the design implications to an early space station to carry out these large space structures technology development missions were determined. Emphasis is being placed on more detail in mission designs and space station resource requirements.

  13. The Phase Diagram of QCD and Some Issues of Large N_c

    SciTech Connect

    McLerran,L.

    2009-02-28

    The large N{sub c} limit provides a good phenomenology of meson spectra and interactions, I discuss some problems with applying the large N{sub c} approximation to the description of baryons, and point out a number of apparent paradoxes and phenomenological difficulties.

  14. The receptor tyrosine phosphatase Lar regulates adhesion between Drosophila male germline stem cells and the niche.

    PubMed

    Srinivasan, Shrividhya; Mahowald, Anthony P; Fuller, Margaret T

    2012-04-01

    The stem cell niche provides a supportive microenvironment to maintain adult stem cells in their undifferentiated state. Adhesion between adult stem cells and niche cells or the local basement membrane ensures retention of stem cells in the niche environment. Drosophila male germline stem cells (GSCs) attach to somatic hub cells, a component of their niche, through E-cadherin-mediated adherens junctions, and orient their centrosomes toward these localized junctional complexes to carry out asymmetric divisions. Here we show that the transmembrane receptor tyrosine phosphatase Leukocyte-antigen-related-like (Lar), which is best known for its function in axonal migration and synapse morphogenesis in the nervous system, helps maintain GSCs at the hub by promoting E-cadherin-based adhesion between hub cells and GSCs. Lar is expressed in GSCs and early spermatogonial cells and localizes to the hub-GSC interface. Loss of Lar function resulted in a reduced number of GSCs at the hub. Lar function was required cell-autonomously in germ cells for proper localization of Adenomatous polyposis coli 2 and E-cadherin at the hub-GSC interface and for the proper orientation of centrosomes in GSCs. Ultrastructural analysis revealed that in Lar mutants the adherens junctions between hub cells and GSCs lack the characteristic dense staining seen in wild-type controls. Thus, the Lar receptor tyrosine phosphatase appears to polarize and retain GSCs through maintenance of localized E-cadherin-based adherens junctions.

  15. Effect of the single-scattering phase function on light transmission through disordered media with large inhomogeneities

    NASA Astrophysics Data System (ADS)

    Marinyuk, V. V.; Sheberstov, S. V.

    2017-01-01

    We calculate the total transmission coefficient (transmittance) of a disordered medium with large (compared to the light wavelength) inhomogeneities. To model highly forward scattering in the medium we take advantage of the Gegenbauer kernel phase function. In a subdiffusion thickness range, the transmittance is shown to be sensitive to the specific form of the single-scattering phase function. The effect reveals itself at grazing angles of incidence and originates from small-angle multiple scattering of light. Our results are in a good agreement with numerical solutions to the radiative transfer equation.

  16. COMPARISON OF TWO DIFFERENT SOLID PHASE EXTRACTION/LARGE VOLUME INJECTION PROCEDURES FOR METHOD 8270

    EPA Science Inventory

    Two solid phase (SPE) and one traditional continuous liquid-liquid extraction method are compared for analysis of Method 8270 SVOCs. Productivity parameters include data quality, sample volume, analysis time and solvent waste.

    One SPE system, unique in the U.S., uses aut...

  17. Sexual swellings in wild white-handed gibbon females (Hylobates lar) indicate the probability of ovulation.

    PubMed

    Barelli, Claudia; Heistermann, Michael; Boesch, Christophe; Reichard, Ulrich H

    2007-02-01

    Conspicuous sexual swellings in the females of some primate species have been a focus of scientific interest since Darwin first wrote about them in 1871. To understand these visual signals, research focused on exaggerated sexual swellings of Old World primates. However, some primate species develop much smaller sexual swellings and it is as yet unclear if these smaller swellings can serve similar functions as those proposed for exaggerated swellings, i.e. advertising fertility to attract mates. We studied the temporal patterns of sexual swellings, timing of ovulation and female reproductive status in wild white-handed gibbons (Hylobates lar) at Khao Yai National Park, Thailand, where this species has a variable social organization. We established fecal progestogen profiles in fifteen cycles of eight cycling females and, to detect swellings outside the menstrual cycle, five pregnant and six lactating females. In 80% of menstrual cycles, ovulation and maximum swelling phase (duration: Ø 9.3 days; 42.8% of cycle length), overlapped tightly. The probability of ovulation peaked on day 3 of the maximum swelling period. Nevertheless, the temporal relationship between maximum swelling and probability of ovulation varied from day -1 to day 13 of the swelling period and three times ovulations fell outside the maximum swelling phase. The different swellings phases occurred in similar proportions in cycling and pregnant, but not lactating females, which were rarely swollen. Despite their smaller size, gibbons' sexual swellings probably serve functions similar to those suggested for exaggerated swellings by the graded-signal hypothesis, which predicts that sexual swellings indicate the probability of ovulation, without allowing males to pinpoint its exact time.

  18. Large-scale controlled fabrication of highly roughened flower-like silver nanostructures in liquid crystalline phase

    PubMed Central

    Yang, Chengliang; Xiang, Xiangjun; Zhang, Ying; Peng, Zenghui; Cao, Zhaoliang; Wang, Junlin; Xuan, Li

    2015-01-01

    Large-scale controllable fabrication of highly roughened flower-like silver nanostructures is demonstrated experimentally via electrodeposition in the liquid crystalline phase. Different sizes of silver flowers are fabricated by adjusting the deposition time and the concentration of the silver nitrate solution. The density of the silver flowers in the sample is also controllable in this work. The flower-like silver nanostructures can serve as effective surface-enhanced Raman scattering and surface-enhanced fluorescence substrates because of their local surface plasmon resonance, and they may have applications in photoluminescence and catalysis. This liquid crystalline phase is used as a soft template for fabricating flower-like silver nanostructures for the first time, and this approach is suitable for large-scale uniform fabrication up to several centimetres. PMID:26216669

  19. Measurement of wavefront structure from large aperture optical components by phase shifting interferometry

    SciTech Connect

    Wolfe, C.R.; Lawson, J.K.; Kellam, M.; Maney, R.T.; Demiris, A.

    1995-05-12

    This paper discusses the results of high spatial resolution measurement of the transmitted or reflected wavefront of optical components using phase shifting interferometry with a wavelength of 6328 {angstrom}. The optical components studied range in size from approximately 50 mm {times} 100 mm to 400 mm {times} 750 mm. Wavefront data, in the form of 3-D phase maps, have been obtained for three regimes of scale length: ``micro roughness``, ``mid-spatial scale``, and ``optical figure/curvature.`` Repetitive wavefront structure has been observed with scale lengths from 10 mm to 100 mm. The amplitude of this structure is typically {lambda}/100 to {lambda}/20. Previously unobserved structure has been detected in optical materials and on the surfaces of components. We are using this data to assist in optimizing laser system design, to qualify optical components and fabrication processes under study in our component development program.

  20. Preliminary results of the large experimental wind turbine phase of the national wind energy program

    NASA Technical Reports Server (NTRS)

    Thomas, R. L.; Sholes, J. E.

    1975-01-01

    A major phase of the wind energy program is the development of reliable wind turbines for supplying cost-competitive electrical energy. This paper discusses the preliminary results of two projects in this phase of the program. First an experimental 100 kW wind turbine design and its status are reviewed. Also discussed are the results of two parallel design studies for determining the configurations and power levels for wind turbines with minimum energy costs. These studies show wind energy costs of 7 to 1.5 c/kWH for wind turbines produced in quantities of 100 to 1000 a year and located at sites having average winds of 12 to 18 mph.

  1. A Phase Locked High Speed Real-Time Interferometry System for Large Amplitude Unsteady Flows

    NASA Technical Reports Server (NTRS)

    Chandrasekhara, M. S.; Squires, D. D.; Wilder, M. C.; Carr, L. W.; Kutler, Paul (Technical Monitor)

    1994-01-01

    A high speed phase locked interferometry system has been designed and developed for real-time measurements of the dynamic stall flow over a pitching airfoil. Point diffraction interferograms of incipient flow separation over a sinusoidally oscillating airfoil have been obtained at rates of up to 20 KHz and for free stream Mach numbers of 0.3 and 0.45. The images were recorded on ASA 125 and ASA 400 film using a drum camera. Special electronic timing and synchronizing circuits were developed to trigger the laser light source from the camera, and to initiate acquisition of the interferogram sequence from any desired phase angle of oscillation. The airfoil instantaneous angle of attack data provided by an optical encoder was recorded via a FIFO and in EPROM into a microcomputer. The interferograms have been analyzed using software developed in-house to get quantitative flow density and pressure distributions.

  2. Two phase choke flow in tubes with very large L/D

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.; Simoneau, R. J.

    1977-01-01

    Data were obtained for two phase and gaseous choked flow nitrogen in a long constant area duct of 16200 L/D with a diverging diffuser attached to the exit. Flow rate data were taken along five isotherms (reduced temperature of 0.81, 0.96, 1.06, 1.12, and 2.34) for reduced pressures to 3. The flow rate data were mapped in the usual manner using stagnation conditions at the inlet mixing chamber upstream of the entrance length. The results are predictable by a two phase homogeneous equilibrium choking flow model which includes wall friction. A simplified theory which in essence decouples the long tube region from the high acceleration choking region also appears to predict the data resonably well, but about 15 percent low.

  3. Study of Pulse Laser Assisted Metalorganic Vapor Phase Epitaxy of InGaN with Large Indium Mole Fraction

    NASA Astrophysics Data System (ADS)

    Kangawa, Yoshihiro; Kawaguchi, Norihito; Hida, Ken-nosuke; Kumagai, Yoshinao; Koukitu, Akinori

    2004-08-01

    The indium composition of the InGaN film increases with decreasing growth temperature; however, the crystalline quality of the film is poor when it is grown at low temperatures. To form a high-quality InGaN film with a large indium mole fraction, Nd: YAG pulse laser assisted metalorganic vapor phase epitaxy (MOVPE) was carried out at low temperatures. The results suggest that film quality can be improved by pulse laser irradiation on the surface of the film.

  4. The allelic variant of LAR gene promoter -127 bp T-->A is associated with reduced risk of obesity and other features related to insulin resistance.

    PubMed

    Miscio, Giuseppe; Tassi, Vittorio; Coco, Angelo; Soccio, Teresa; Di Paola, Rosa; Prudente, Sabrina; Baratta, Roberto; Frittitta, Lucia; Ludovico, Ornella; Padovano, Libera; Dallapiccola, Bruno; Di Mario, Umberto; De Cosmo, Salvatore; Trischitta, Vincenzo

    2004-07-01

    Insulin resistance, which is pathogenic for type 2 diabetes (T2D), is under the control of largely unknown genetic determinants. LAR, a protein-tyrosine phosphatase which inhibits insulin signalling, is overexpressed in animal and human models of insulin resistance. We studied the entire sequence of the LAR gene by SSCP analysis and automatic DNA sequencing, with the aim of verifying whether its sequence variants might be associated with insulin resistance. In the 276 bp sequence upstream of the transcriptional start site (i.e. a region we have identified as having basal promoter activity) a -127 bp T-->A SNP (5% frequency) was associated with lower body mass index (BMI) ( P=0.03), waist circumference ( P=0.01), blood pressure ( P=0.01) and urinary albumin/creatinine ratio ( P=0.04) in 589 non-diabetic unrelated individuals from the Gargano region (central east coast of Italy). To quantify the risk for a high body weight conferred by the -127 T-->A SNP, the whole cohort was divided into tertiles according to the individual BMI. The risk of belonging to the heavier tertile, as compared to the leaner one, was reduced by approximately 60%. In a population from East Sicily ( n=307), T/A genotype carriers ( n=13) showed lower triglyceride levels ( P=0.04) and higher insulin sensitivity as indicated by lower plasma glucose ( P=0.03) and serum insulin ( P=0.006) during oral glucose tolerance testing (OGTT). Promoter activity, studied by cDNA transfection experiments, was similar for the A and T alleles. In conclusion, a genetic variant of the LAR gene promoter is consistently associated with features of insulin resistance in two different Caucasian populations. Although the biological relevance of this variant has yet to be determined, this finding underlines the potential importance of the LAR gene in dysregulation of insulin sensitivity and related disorders.

  5. SALM5 trans-synaptically interacts with LAR-RPTPs in a splicing-dependent manner to regulate synapse development

    PubMed Central

    Choi, Yeonsoo; Nam, Jungyong; Whitcomb, Daniel J.; Song, Yoo Sung; Kim, Doyoun; Jeon, Sangmin; Um, Ji Won; Lee, Seong-Gyu; Woo, Jooyeon; Kwon, Seok-Kyu; Li, Yan; Mah, Won; Kim, Ho Min; Ko, Jaewon; Cho, Kwangwook; Kim, Eunjoon

    2016-01-01

    Synaptogenic adhesion molecules play critical roles in synapse formation. SALM5/Lrfn5, a SALM/Lrfn family adhesion molecule implicated in autism spectrum disorders (ASDs) and schizophrenia, induces presynaptic differentiation in contacting axons, but its presynaptic ligand remains unknown. We found that SALM5 interacts with the Ig domains of LAR family receptor protein tyrosine phosphatases (LAR-RPTPs; LAR, PTPδ, and PTPσ). These interactions are strongly inhibited by the splice insert B in the Ig domain region of LAR-RPTPs, and mediate SALM5-dependent presynaptic differentiation in contacting axons. In addition, SALM5 regulates AMPA receptor-mediated synaptic transmission through mechanisms involving the interaction of postsynaptic SALM5 with presynaptic LAR-RPTPs. These results suggest that postsynaptic SALM5 promotes synapse development by trans-synaptically interacting with presynaptic LAR-RPTPs and is important for the regulation of excitatory synaptic strength. PMID:27225731

  6. Gibbon (Hylobates lar) reintroduction success in Phuket, Thailand, and its conservation benefits.

    PubMed

    Osterberg, Petra; Samphanthamit, Phamon; Maprang, Owart; Punnadee, Suwit; Brockelman, Warren Y

    2015-05-01

    We summarize the results from a long-term gibbon reintroduction project in Phuket, Thailand, and evaluate its benefits to conservation. Between October 2002 and November 2012, eight breeding families of white-handed gibbons (Hylobates lar) were returned to the wild in Khao Phra Thaew non-hunting area (KPT). Wild gibbons were extirpated from Phuket Island by the early 1980s, but the illegal wildlife trade has continued to bring young gibbons from elsewhere to the island's popular tourist areas as pets and photo props. The Gibbon Rehabilitation Project (GRP) has rescued and rehabilitated confiscated and donated captive gibbons since 1992 and aims to repopulate the island's last sizable forest area. Following unsuccessful early attempts at translocation in the 1990s, GRP has now developed specific methods for gibbon reintroduction that have led to the establishment of a small independent, reproducing population of captive-raised and wild-born gibbons on Phuket. Eleven infants have been born wild within the reintroduced population, including a second generation wild-born gibbon in September 2012. Benefits of the GRP project include restoration of the gibbon population on Phuket, rescue of illegally kept gibbons, public education, training of personnel in gibbon conservation work, and gaining experience which may prove useful in saving more severely threatened species. It is unlikely that gibbon (and other large primate) translocations will make a significant contribution to conservation of the species as a whole, and primate translocation projects should not be judged solely by this criterion.

  7. The Drosophila Receptor Protein Tyrosine Phosphatase LAR Is Required for Development of Circadian Pacemaker Neuron Processes That Support Rhythmic Activity in Constant Darkness But Not during Light/Dark Cycles

    PubMed Central

    Agrawal, Parul

    2016-01-01

    In Drosophila, a transcriptional feedback loop that is activated by CLOCK-CYCLE (CLK-CYC) complexes and repressed by PERIOD-TIMELESS (PER-TIM) complexes keeps circadian time. The timing of CLK-CYC activation and PER-TIM repression is regulated post-translationally, in part through rhythmic phosphorylation of CLK, PER, and TIM. Although kinases that control PER, TIM, and CLK levels, activity, and/or subcellular localization have been identified, less is known about phosphatases that control clock protein dephosphorylation. To identify clock-relevant phosphatases, clock-cell-specific RNAi knockdowns of Drosophila phosphatases were screened for altered activity rhythms. One phosphatase that was identified, the receptor protein tyrosine phosphatase leukocyte-antigen-related (LAR), abolished activity rhythms in constant darkness (DD) without disrupting the timekeeping mechanism in brain pacemaker neurons. However, expression of the neuropeptide pigment-dispersing factor (PDF), which mediates pacemaker neuron synchrony and output, is eliminated in the dorsal projections from small ventral lateral (sLNv) pacemaker neurons when Lar expression is knocked down during development, but not in adults. Loss of Lar function eliminates sLNv dorsal projections, but PDF expression persists in sLNv and large ventral lateral neuron cell bodies and their remaining projections. In contrast to the defects in lights-on and lights-off anticipatory activity seen in flies that lack PDF, Lar RNAi knockdown flies anticipate the lights-on and lights-off transition normally. Our results demonstrate that Lar is required for sLNv dorsal projection development and suggest that PDF expression in LNv cell bodies and their remaining projections mediate anticipation of the lights-on and lights-off transitions during a light/dark cycle. SIGNIFICANCE STATEMENT In animals, circadian clocks drive daily rhythms in physiology, metabolism, and behavior via transcriptional feedback loops. Because key circadian

  8. Resonant X-Ray Diffraction Study of an Unusually Large Phase Coexistance in Smectic Liquid-Crystal Films

    SciTech Connect

    Pan L.; Pindak R.; Barois, P.; Liu, Z.Q.; McCoy, B.K. & Hyang, C.C.

    2012-01-19

    The recent discovery of the new smectic-C{sub d6}* (SmC{sub d6}*) phase [S. Wang et al. Phys. Rev. Lett. 104 027801 (2010)] also revealed the existence of a noisy region in the temperature window between the SmC{sub d6}* phase and the smectic-C{sub d4}* (SmC{sub d4}*) phase. Characterized by multiple resonant peaks spanning a wide region in Q{sub Z}, the corresponding structure of this temperature window has been a mystery. In this Letter, through a careful resonant x-ray diffraction study and simulations of the diffraction spectra, we show that this region is in fact an unusually large coexistence region of the SmC{sub d6}* phase and the SmC{sub d4}* phase. The structure of the noisy region is found to be a heterogeneous mixture of local SmC{sub d6}* and SmC{sub d4}* orders on the sub-{micro}m scale.

  9. Linear enamel hypoplasia in gibbons (Hylobates lar carpenteri).

    PubMed

    Guatelli-Steinberg, D

    2000-07-01

    This study describes the expression of linear enamel hypoplasia (LEH), a sensitive dental indicator of physiological stress, in Thailand gibbons (Hylobates lar carpenteri). Previous studies of enamel hypoplasia in hominoids have focused on great apes, with little attention given to the expression of this stress indicator in gibbons. In that gibbons differ from both monkeys and great apes in numerous life history features, LEH expression in gibbons might be expected to show significant differences from both. In this study, 92 gibbon specimens from two sites in Thailand were compared with several samples of monkeys and great apes in their expression of LEH. The intertooth distribution of LEH in gibbons was compared to that of chimpanzees and rhesus monkeys. Gibbon populations from both sites exhibit LEH frequencies intermediate between those of the monkey samples, in which LEH prevalence is usually low, and those of the great ape samples, in which LEH prevalence is high. Gibbons differ significantly from monkeys, but not great apes, in the number of individuals whose teeth record multiple stress events. Multiple episodes of stress are rarely recorded in the teeth of monkeys, while multiple stress events occur with higher frequency in gibbons and great apes. Taxonomic variation in the duration of crown formation, the prominence and spacing of perikymata on dental crowns, life history features, and/or experience of physiological stress may explain these patterns. The intertooth distribution of LEH in gibbons is, for different reasons, unlike that of either chimpanzees or rhesus monkeys. The mandibular canines of gibbons have significantly more LEH than any of their other teeth. Aspects of crown morphology, perikymata prominence/spacing, enamel thickness, and crown formation spans are potential causes of taxonomic variation in the intertooth distribution of LEH.

  10. Evaluation of large format electron bombarded virtual phase CCDs as ultraviolet imaging detectors

    NASA Technical Reports Server (NTRS)

    Opal, Chet B.; Carruthers, George R.

    1989-01-01

    In conjunction with an external UV-sensitive cathode, an electron-bombarded CCD may be used as a high quantum efficiency/wide dynamic range photon-counting UV detector. Results are presented for the case of a 1024 x 1024, 18-micron square pixel virtual phase CCD used with an electromagnetically focused f/2 Schmidt camera, which yields excellent simgle-photoevent discrimination and counting efficiency. Attention is given to the vacuum-chamber arrangement used to conduct system tests and the CCD electronics and data-acquisition systems employed.

  11. A Parameterized Pattern-Error Objective for Large-Scale Phase-Only Array Pattern Design

    DTIC Science & Technology

    2016-03-21

    only arrays,” in Proc. Int’l Conf. on Neural Networks and Signal Processing, vol. 2, 2003, pp. 1290–1293. 24. I. D. Olin, “Flat-top sector beams...failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE...transmitters will continue to offer only phase control . This considerably complicates the design of custom array patterns for transmit arrays, as all but

  12. Preliminary results of the large experimental wind turbine phase of the national wind energy program

    NASA Technical Reports Server (NTRS)

    Thomas, R. L.; Sholes, T.; Sholes, J. E.

    1975-01-01

    The preliminary results of two projects in the development phase of reliable wind turbines designed to supply cost-competitive electrical energy were discussed. An experimental 100 kW wind turbine design and its status are first reviewed. The results of two parallel design studies for determining the configurations and power levels for wind turbines with minimum energy costs are also discussed. These studies predict wind energy costs of 1.5 to 7 cents per kW-h for wind turbines produced in quantities of 100 to 1000 per year and located at sites having average winds of 12 to 18 mph.

  13. Climate phase drives canopy condition in a large semi-arid floodplain forest.

    PubMed

    Wen, Li; Saintilan, Neil

    2015-08-15

    To maintain and restore the ecological integrity of floodplains, allocating water for environmental benefits (i.e. environmental water) is widely practised globally. To efficiently manage the always limited environmental water, there is pressing need to advance our understanding of the ecological response to long-term climate cycles as evidence grows of intensification of extreme climatic events such as severe drought and heat waves. In this study, we assessed the alleviating effects of artificial flooding on drought impact using the canopy condition of the iconic river red gum forests in Australia's Murray Darling Basin (MDB). To achieve this, we jointly analysed spatial-temporal patterns of NDVI response and drought conditions for the period of 2000-2013, during which the MDB experienced an extreme dry-wet cycle. Our results indicated that while NDVI-derived canopy condition was better at the sites receiving environmental water during the dry phases, both watered and unwatered sites displayed great similarity in seasonality and trends. Furthermore, we did not find any significant difference in NDVI response of the canopy between the sites to suggest significant differences in ecosystem stability and resilience, with watered and unwatered sites showing similar responses to the extreme wet conditions as the drought broke. The highly significant relationship between long-term drought index and NDVI anomaly suggest that climate phase is the main forcing driving canopy condition in semi-arid floodplain forests.

  14. Main-chain Chiral Smectic Polymers Showing a Large Electroclinic Effect in the SmA* Phase

    SciTech Connect

    Walba,D.; Yang, H.; Shoemaker, R.; Keller, P.; Shao, r.; Coleman, D.; Jones, C.; Nakata, M.; Clark, N.

    2006-01-01

    The synthesis and characterization of a main-chain smectic liquid-crystalline polymer system designed for development into electromechanical actuators is described. The chemical structure is chosen to provide a large electroclinic effect in the SmA* phase, with large concomitant layer shrinkage (a rare combination). The polymers are prepared by acyclic diene metathesis polymerization (ADMET) of liquid-crystalline ,-dienes. Oligomers with a degree of polymerization of {approx}10-30 are obtained using Grubbs first-generation catalyst, while oligomers with a degree of polymerization of {approx}200 are obtained using Grubbs second-generation catalyst. All polymer samples show the following phase sequence: I - SmA* - SmC* - Glass. X-ray analysis of polymer powder samples demonstrates the desired layer shrinkage at the SmA* - SmC* transition. The polymers form well-aligned fibers by pulling from the isotropic melt, and X-ray analysis of fibers in the SmA* phase shows that in the bulk of the fiber the layers are oriented perpendicular to the fiber axis, while at the surfaces there appears to be a thin sheath where the layers are parallel to the fiber/air interface. The desired layer shrinkage with tilt at the SmA* - SmC* transition in these fibers is seen as well, and in the SmC* phase the fibers exhibit an interesting conical chevron layer structure. Electro-optic investigation of aligned thin films of the polymer, prepared from quenched fiber glasses using a novel technique, exhibit a large electroclinic effect, with substantial degradation of alignment quality upon field-induced tilt. This degradation in alignment quality, coupled with the layer shrinkage at the SmA* - SmC* transition demonstrated by X-ray scattering, strongly suggests the desired layer shrinkage with electroclinic tilt is in fact occurring in the polymer films.

  15. Report on phase 1 of the Microprocessor Seminar. [and associated large scale integration

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Proceedings of a seminar on microprocessors and associated large scale integrated (LSI) circuits are presented. The potential for commonality of device requirements, candidate processes and mechanisms for qualifying candidate LSI technologies for high reliability applications, and specifications for testing and testability were among the topics discussed. Various programs and tentative plans of the participating organizations in the development of high reliability LSI circuits are given.

  16. Structure/property development in aPET during large strain, solid phase polymer processing

    NASA Astrophysics Data System (ADS)

    Martin, Peter; Mohamed, Raja Roslan Raja

    2015-12-01

    Amorphous Polyethylene terephthalate (aPET) is increasingly of interest for the polymer packaging industry due to its blend of excellent mechanical properties and most importantly its ease of recyclability. Among the major commercial polymers it is almost unique in the degree of improvement in mechanical properties that can be obtained through process-induced strain. For many years these unique properties have been very successfully exploited in the injection stretch blow molding process, where it is deliberately stretched to very large strains using extremely high pressures. However, the material is now also being used in much lower pressure processes such as thermoforming where its properties are often not fully exploited. In this work the change in structure and properties of aPET with strain is systematically investigated using a high speed biaxial stretching machine. The aim was to demonstrate how the properties of the material could be controlled by large strain, high temperature biaxial stretching processes such as thermoforming and blow molding. The results show that property changes in the material are driven by orientation and the onset of rapid strain hardening at large strains. This in turn is shown to vary strongly with process-induced parameters such as the strain rate and the mode and magnitude of biaxial deformation.

  17. Phase-B activities for the Large Isotope Spectrometer for Astromag

    NASA Technical Reports Server (NTRS)

    Mewaldt, Richard A.; Stone, E. C.

    1995-01-01

    The scientific objectives of the LISA experiment are to (1) extend measurements of the isotopic composition of cosmic ray elements from Be to Ni (Z = 4 to 28) into the energy range beyond 1 GeV per nucleon; (2) to measure the energy spectra of heavy elements up to energies greater than 100 GeV/nucleon with good statistical accuracy; and (3) to search for heavy anti-matter with Z greater than 2 in cosmic rays. This grant focussed on defining the Cherenkov subsystem of the LISA experiment. The Phase-B efforts included the following activities: (1) definition of the LISA Cherenkov counters for the Space Station version of Astromag; (2) testing of the 5-inch fine mesh photomultipliers; (3) development of the aerogel radiator; and (4) study of a free-flyer version of Astromag.

  18. Large conversion of energy in dielectric elastomers by electromechanical phase transition

    NASA Astrophysics Data System (ADS)

    Lu, Tong-Qing; Suo, Zhi-Gang

    2012-08-01

    When air is pumped in, a tubular balloon initially inflates slightly and homogeneously. A short section of the balloon then forms a bulge, which coexists with the unbulged section of the balloon. As more air is pumped in, the bulged section elongates at the expense of the unbulged section, until the entire balloon is bulged. The phenomenon is analogous to the liquid-to-vapor phase transition. Here we study the bulging transition in a dielectric elastomer tube as air is pumped into the balloon and a voltage is applied through the thickness of the membrane. We formulate the condition for coexistent budged and unbulged sections, and identify allowable states set by electrical breakdown and mechanical rupture. We find that the bulging transition dramatically amplifies electromechanical energy conversion. Energy converted in an electromechanical cycle consisting of unbulged and bulged states is thousands of times that in an electromechanical cycle consisting of only unbulged states.

  19. Phase transitions and metastability in the distribution of the bipartite entanglement of a large quantum system

    SciTech Connect

    De Pasquale, A.; Facchi, P.; Parisi, G.; Pascazio, S.; Scardicchio, A.

    2010-05-15

    We study the distribution of the Schmidt coefficients of the reduced density matrix of a quantum system in a pure state. By applying general methods of statistical mechanics, we introduce a fictitious temperature and a partition function and translate the problem in terms of the distribution of the eigenvalues of random matrices. We investigate the appearance of two phase transitions, one at a positive temperature, associated with very entangled states, and one at a negative temperature, signaling the appearance of a significant factorization in the many-body wave function. We also focus on the presence of metastable states (related to two-dimensional quantum gravity) and study the finite size corrections to the saddle point solution.

  20. Precision SAW filters for a large phased-array radar system

    NASA Astrophysics Data System (ADS)

    Haydl, W. H.; Sander, W.; Wirth, W.-D.

    1981-05-01

    The electronically steerable radar (ELRA) at the Forschungsinstitut fuer Funk und Mathematik is an experimental S-band phased-array radar system consisting of separate transmitting and receiving arrays employing several coherent and incoherent signal-processing and data-handling techniques, incorporating multiple beam and multifunction operation for target search and tracking, adaptive interference suppression, and target resolution. This paper deals with the development and application of two types of SAW filters for the IF amplifier channel of the receiving array. Compared to conventional filters with lumped elements, these filters have some important merits. By making use of a special tuning technique, the center frequencies of all filters were adjusted, resulting in an rms deviation of less than 1 kHz. One type of the SAW filters represents an almost ideal approach of realizing a matched filter for rectangular shaped pulses. The conformity of the frequency responses of several hundred filters improved the noise suppression capability of the system.

  1. Large Area Crop Inventory Experiment (LACIE). Phase 3 direct wheat study of North Dakota

    NASA Technical Reports Server (NTRS)

    Kinsler, M. C.; Nichols, J. D.; Ona, A. L. (Principal Investigator)

    1979-01-01

    The author has identified the following significant results. The green number and brightness scatter plots, channel plots of radiance values, and visual study of the imagery indicate separability between barley and spring wheat/oats during the wheat mid-heading to mid-ripe stages. In the LACIE Phase 3 North Dakota data set, the separation time is more specifically the wheat soft dough stage. At this time, the barley is ripening, and is therefore, less green and brighter than the wheat. Only 4 of the 18 segments studied indicate separation of barley/other spring small grain, even though 11 of the segments have acquisitions covering the wheat soft dough stage. The remaining seven segments had less than 5 percent barley based on ground truth data.

  2. The study of large biopolymer complexes in solution and the gas phase using electrospray ionization-FTICR mass spectrometry

    SciTech Connect

    Smith, R.D.; Lei, Q.P.; Wu, Qinyuan; Hofstadler, A.

    1997-12-31

    Electrospray ionization (ESI) can transfer large biopolymers and many noncovalently bound complexes into the gas phase and to preserve specific noncovalent biomolecular associations for subsequent mass spectrometric analysis. Although a number of details of the ESI process remain a subject of debate, it is now incontestable that many weak associations can survive transfer to the gas phase and are stable for periods of at least seconds. In this presentation, the application of ESI-Fourier transform ion cyclotron resonance (FTICR) mass spectrometry methods for the study of large biopolymers and their noncovalent complexes will be described. It will also be shown that competitive binding studies can be used to quickly establish relative binding affinities in solution, allowing combinatorial libraries to be rapidly screened. After measurements of the intact complex, dissociation studies can be conducted to probe the structure of the individual constituents of complexes. Studies comparing the relative stabilities of protein-ligand complexes in solution and desolvated in the gas phase will also be presented, and discussed from both fundamental and analytical perspectives.

  3. The topology of large-scale structure. I - Topology and the random phase hypothesis. [galactic formation models

    NASA Technical Reports Server (NTRS)

    Weinberg, David H.; Gott, J. Richard, III; Melott, Adrian L.

    1987-01-01

    Many models for the formation of galaxies and large-scale structure assume a spectrum of random phase (Gaussian), small-amplitude density fluctuations as initial conditions. In such scenarios, the topology of the galaxy distribution on large scales relates directly to the topology of the initial density fluctuations. Here a quantitative measure of topology - the genus of contours in a smoothed density distribution - is described and applied to numerical simulations of galaxy clustering, to a variety of three-dimensional toy models, and to a volume-limited sample of the CfA redshift survey. For random phase distributions the genus of density contours exhibits a universal dependence on threshold density. The clustering simulations show that a smoothing length of 2-3 times the mass correlation length is sufficient to recover the topology of the initial fluctuations from the evolved galaxy distribution. Cold dark matter and white noise models retain a random phase topology at shorter smoothing lengths, but massive neutrino models develop a cellular topology.

  4. Post-Flashover Fires in Simulated Shipboard Compartments - Phase 3. Venting of Large Shipboard Fires

    DTIC Science & Technology

    1993-06-09

    hose 1/4 Turn ball valves 1s4 Turn a e/4 Turnbal valve" ball valve Corna 18en9 11.9cm b h(50 gal.) (.30 gal.) ýPa Fuel nzFuelTank /Tank Strainer F ...III Venting of Large Shipboard Fires F . W. WILLIAMS Navy Technology Center for Safety and Survivability, Chemistry Division G. G. BACK, T. A. TOOMEY, R...the fire compartment. The temperatures in the fire compartment were observed to initially increase from 6000C to over 8000C (111 2PF to over 1472- F

  5. Treatment of autonomic neuropathy, postural tachycardia and orthostatic syncope with octreotide LAR.

    PubMed

    Hoeldtke, Robert D; Bryner, Kimberly D; Hoeldtke, Martin E; Hobbs, Gerald

    2007-12-01

    The purpose of this study was to determine whether autonomic neuropathy and the postural tachycardia syndrome can be treated with octreotide LAR (Long Acting Release). This was an open-label pilot project. Protocol 1 Patients with autonomic neuropathy (n = 4) were given increasing doses of octreotide LAR once a month for three months. Blood pressure was measured in the sitting posture every two weeks. Pretreatment mean blood pressure averaged 83.8 +/- 7.1 mm Hg. After four, six and eight weeks of therapy the blood pressures averaged 96.3 +/- 6.4, 98.2 +/- 6.1 (p < .025), and 104.1 +/- 3.1 (p < .025) respectively. Therapy led to a dramatic improvement in symptoms in one patient but another had an unacceptable elevation in supine blood pressure. Protocol 2 Patients with POTS or orthostatic intolerance were given 10, 20, or 30 mg of octreotide LAR over three months. Seven patients entered and five completed the study. After two months treatment, standing time increased from 36.0 +/- 9.2 to 59.2 +/- .8 minutes (p < .01). Heart rate in the standing position was suppressed from 106 +/- .83 to 93.2 +/- .8 beats per minute (p < .05). Orthostatic dizziness and chronic fatigue improved. We conclude that octreotide LAR can be used to treat autonomic neuropathy but there is a risk of an excessive pressor response. Octreotide LAR improved standing time and suppressed tachycardia in patients with orthostatic intolerance.

  6. The Liquid Argon Software Toolkit (LArSoft): Goals, Status and Plan

    SciTech Connect

    Pordes, Rush; Snider, Erica

    2016-08-17

    LArSoft is a toolkit that provides a software infrastructure and algorithms for the simulation, reconstruction and analysis of events in Liquid Argon Time Projection Chambers (LArTPCs). It is used by the ArgoNeuT, LArIAT, MicroBooNE, DUNE (including 35ton prototype and ProtoDUNE) and SBND experiments. The LArSoft collaboration provides an environment for the development, use, and sharing of code across experiments. The ultimate goal is to develop fully automatic processes for reconstruction and analysis of LArTPC events. The toolkit is based on the art framework and has a well-defined architecture to interface to other packages, including to GEANT4 and GENIE simulation software and the Pandora software development kit for pattern recognition. It is designed to facilitate and support the evolution of algorithms including their transition to new computing platforms. The development of the toolkit is driven by the scientific stakeholders involved. The core infrastructure includes standard definitions of types and constants, means to input experiment geometries as well as meta and event- data in several formats, and relevant general utilities. Examples of algorithms experiments have contributed to date are: photon-propagation; particle identification; hit finding, track finding and fitting; electromagnetic shower identification and reconstruction. We report on the status of the toolkit and plans for future work.

  7. Fabrication of large area X-ray diffraction grating for X-ray phase imaging

    SciTech Connect

    Noda, Daiji; Tokuoka, Atsushi; Katori, Megumi; Minamiyama, Yasuto; Yamashita, Kenji; Nishida, Satoshi; Hattori, Tadashi

    2012-07-31

    X-ray lithography, which uses highly directional synchrotron radiation, is one of the technologies that can be used for fabricating micrometer-sized structures. In X-ray lithography, the accuracy of the fabricated structure depends largely on the accuracy of the X-ray mask. Since X-ray radiation is highly directional, a micro-fabrication technology that produces un-tapered and high aspect ratio highly absorbent structures on a low absorbent membrane is required. Conventionally, a resin material is used as the support membrane for large area X-ray masks. However, resin membranes have the disadvantage that they can sag after several cycles of X-ray exposure due to the heat generated by the X-rays. Therefore, we proposed and used thin carbon wafers for the membrane material because carbon has an extremely small thermal expansion coefficient. We fabricated new carbon membrane X-ray masks, and these results of X-ray lithography demonstrate the superior performance.

  8. On the cognitive neurodynamics of listening effort: a phase clustering analysis of large-scale neural correlates.

    PubMed

    Strauss, Daniel J; Corona-Strauss, Farah I; Bernarding, Corinna; Reith, Wolfgang; Latzel, Matthias; Froehlich, Matthias

    2009-01-01

    An increased listening effort represents a major problem in humans with hearing impairment. Neurodiagnostic methods for an objective listening effort estimation could revolutionize auditory rehabilitation. However the cognitive neurodynamics of listening effort is not understood and research related its neural correlates is still in its infancy. In this paper we present a phase clustering analysis of large-scale listening effort correlates in auditory late responses (ALRs). For this we apply the complex wavelet transform as well as tight Gabor Frame (TGF) operators. We show (a) that phase clustering on the unit circle can separate ALR data from auditory paradigms which require a graduated effort for their solution; (b) the application of TGFs for an inverse artificial phase stabilization at the alpha/theta-border enlarges the endogenously driven listening effort correlates in the reconstructed time- domain waveforms. It is concluded that listening effort correlates can be extracted from ALR sequences using an instantaneous phase clustering analysis, at least by means of the applied experimental pure tone paradigm.

  9. Insights into large-scale cell-culture reactors: II. Gas-phase mixing and CO₂ stripping.

    PubMed

    Sieblist, Christian; Hägeholz, Oliver; Aehle, Mathias; Jenzsch, Marco; Pohlscheidt, Michael; Lübbert, Andreas

    2011-12-01

    Most discussions about stirred tank bioreactors for cell cultures focus on liquid-phase motions and neglect the importance of the gas phase for mixing, power input and especially CO(2) stripping. Particularly in large production reactors, CO(2) removal from the culture is known to be a major problem. Here, we show that stripping is mainly affected by the change of the gas composition during the movement of the gas phase through the bioreactor from the sparger system towards the headspace. A mathematical model for CO(2)-stripping and O(2)-mass transfer is presented taking gas-residence times into account. The gas phase is not moving through the reactor in form of a plug flow as often assumed. The model is validated by measurement data. Further measurement results are presented that show how the gas is partly recirculated by the impellers, thus increasing the gas-residence time. The gas-residence times can be measured easily with stimulus-response techniques. The results offer further insights on the gas-residence time distributions in stirred tank reactors.

  10. Novel concepts for the compression of large volumes of carbon dioxide-phase III

    SciTech Connect

    Moore, J. Jeffrey; Allison, Timothy C.; Evans, Neal D.; Moreland, Brian; Hernandez, Augusto J.; Day, Meera; Ridens, Brandon L.

    2014-06-30

    In the effort to reduce the release of CO2 greenhouse gases to the atmosphere, sequestration of CO2 from Integrated Gasification Combined Cycle (IGCC) and Oxy-Fuel power plants is being pursued. This approach, however, requires significant compression power to boost the pressure to typical pipeline levels. The penalty can be as high as 8-12% on a typical IGCC plant. The goal of this research is to reduce this penalty through novel compression concepts and integration with existing IGCC processes. The primary objective of the study of novel CO2 compression concepts is to reliably boost the pressure of CO2 to pipeline pressures with the minimal amount of energy required. Fundamental thermodynamics were studied to explore pressure rise in both liquid and gaseous states. For gaseous compression, the project investigated novel methods to compress CO2 while removing the heat of compression internal to the compressor. The highpressure ratio, due to the delivery pressure of the CO2 for enhanced oil recovery, results in significant heat of compression. Since less energy is required to boost the pressure of a cooler gas stream, both upstream and inter-stage cooling is desirable. While isothermal compression has been utilized in some services, it has not been optimized for the IGCC environment. Phase I of this project determined the optimum compressor configuration and developed technology concepts for internal heat removal. Other compression options using liquefied CO2 and cryogenic pumping were explored as well. Preliminary analysis indicated up to a 35% reduction in power is possible with the new concepts being considered. In the Phase II program, two experimental test rigs were developed to investigate the two concepts further. A new pump loop facility was constructed to qualify a cryogenic turbopump for use on liquid CO2 . Also, an internally cooled compressor diaphragm was developed

  11. Yb³⁺-doped large core silica fiber for fiber laser prepared by glass phase-separation technology.

    PubMed

    Chu, Yingbo; Ma, Yunxiu; Yang, Yu; Liao, Lei; Wang, Yibo; Hu, Xiongwei; Peng, Jinggang; Li, Haiqing; Dai, Nengli; Li, Jinyan; Yang, Luyun

    2016-03-15

    We report on the preparation and optical characteristics of an Yb(3+)-doped large core silica fiber with the active core prepared from nanoporous silica rod by the glass phase-separation technology. The measurements show that the fiber has an Yb(3+) concentration of 9811 ppm by weight, a low background attenuation of 0.02 dB/m, and absorption from Yb(3+) about 5.5 dB/m at 976 nm. The laser performance presents a high slope efficiency of 72.8% for laser emission at 1071 nm and a low laser threshold of 3 W within only 2.3 m fiber length. It is suggested that the glass phase-separation technology shows great potential for realizing active fibers with larger core and complex fiber designs.

  12. Phase II Study to Assess the Efficacy of Hypofractionated Stereotactic Radiotherapy in Patients With Large Cavernous Sinus Hemangiomas

    SciTech Connect

    Wang Xin; Liu Xiaoxia; Mei Guanghai; Dai Jiazhong; Pan Li; Wang Enmin

    2012-06-01

    Purpose: Cavernous sinus hemangioma is a rare vascular tumor. The direct microsurgical approach usually results in massive hemorrhage. Although radiosurgery plays an important role in managing cavernous sinus hemangiomas as a treatment alternative to microsurgery, the potential for increased toxicity with single-session treatment of large tumors is a concern. The purpose of this study was to assess the efficacy of hypofractionated stereotactic radiotherapy in patients with large cavernous sinus hemangiomas. Methods: Fourteen patients with large (volume >20 cm{sup 3}) cavernous sinus hemangiomas were enrolled in a prospective Phase II study between December 2007 and December 2010. The hypofractionated stereotactic radiotherapy dose was 21 Gy delivered in 3 fractions. Results: After a mean follow-up of 15 months (range, 6-36 months), the magnetic resonance images showed a mean of 77% tumor volume reduction (range, 44-99%). Among the 6 patients with cranial nerve impairments before hypofractionated stereotactic radiotherapy, 1 achieved symptomatic complete resolution and 5 had improvement. No radiotherapy-related complications were observed during follow-up. Conclusion: Our current experience, though preliminary, substantiates the role of hypofractionated stereotactic radiotherapy for large cavernous sinus hemangiomas. Although a longer and more extensive follow-up is needed, hypofractionated stereotactic radiotherapy of 21 Gy delivered in 3 fractions is effective in reducing the tumor volume without causing any new deficits and can be considered as a treatment modality for large cavernous sinus hemangiomas.

  13. Large magneto-optic enhancement in ultra-thin liquid-phase-epitaxy iron garnet films

    SciTech Connect

    Levy, Miguel; Chakravarty, A.; Huang, H.-C.; Osgood, R. M.

    2015-07-06

    Significant departures from bulk-like magneto-optic behavior are found in ultra-thin bismuth-substituted iron-garnet films grown by liquid-phase-epitaxy. These changes are due, at least in part, to geometrical factors and not to departures from bulk-composition in the transient layer at the film-substrate interface. A monotonic increase in specific Faraday rotation with reduced thickness is the signature feature of the observed phenomena. These are traced to size-dependent modifications in the diamagnetic transition processes responsible for the Faraday rotation. These processes correspond to the electronic transitions from singlet {sup 6}S ground states to spin-orbit split excited states of the Fe{sup 3+} ions in the garnet. A measurable reduction in the corresponding ferrimagnetic resonance linewidths is found, thus pointing to an increase in electronic relaxation times and longer lived excitations at reduced thicknesses. These changes together with a shift in vibrational frequency of the Bi-O bonds in the garnet at reduced thicknesses result in greatly enhanced magneto-optical performance. These studies were conducted on epitaxial monocrystalline Bi{sub 0.8}Gd{sub 0.2}Lu{sub 2}Fe{sub 5}O{sub 12} films.

  14. Phase Transition for the Large-Dimensional Contact Process with Random Recovery Rates on Open Clusters

    NASA Astrophysics Data System (ADS)

    Xue, Xiaofeng

    2016-12-01

    In this paper we are concerned with the contact process with random recovery rates on open clusters of bond percolation on Z^d. Let ξ be a random variable such that P(ξ ≥ 1)=1, which ensures E1/ξ <+∞, then we assign i. i. d. copies of ξ on the vertices as the random recovery rates. Assuming that each edge is open with probability p and the infection can only spread through the open edges, then we obtain that limsup _{d→ +∞}λ _d≤ λ _c=1/pE{1}/{ξ}, where λ _d is the critical value of the process on Z^d, i.e., the maximum of the infection rates with which the infection dies out with probability one when only the origin is infected at t=0. To prove the above main result, we show that the following phase transition occurs. Assuming that lceil log drceil vertices are infected at t=0, where these vertices can be located anywhere, then when the infection rate λ >λ _c, the process survives with high probability as d→ +∞ while when λ <λ _c, the process dies out at time O(log d) with high probability.

  15. Composite optical fiber polarizer with ternary copolymer overlay for large range modulation of phase difference

    NASA Astrophysics Data System (ADS)

    Cui, Minxin; Tian, Xiujie; Zou, Gang; Zhu, Bing; Zhang, Qijin

    2017-04-01

    In this work, a ternary copolymer composed of (E)-2-(4-((4-isocyanophenyl) diazenyl) phenoxy) ethyl methacrylate (2-CN), methacrylisobutyl polyhedral oligomeric silsesquioxane (MAPOSS) and 2,2,2-trifluoroethyl methacrylate (TFEMA) is synthesized and used as the overlay for composite optical fiber, in which cage-like POSS component and fluorine-containing component are used to reduce refractive index, and azobenzene component is used to finely manipulate the refractive indices in two orthogonal directions through photo-induced orientation under irradiation of polarized light. Before irradiation, the refractive index of terpolymer (1.4503) is slightly higher than that of the core material (1.4489) of commercial silica single-mode fiber, which is obtained by optimizing the amount of each monomer. After the irradiation of 435 nm polarized light, refractive indices of the overlay in two orthogonal directions decrease, and two values have been finely manipulated so that one is higher and another is lower than the refractive index of the fiber core by optimizing irradiation time. In this way, a radial loss type fiber polarization modulator is obtained. By changing the polarization direction of the irradiation at 435 nm, the polarization of propagating light at 1550 nm in the fiber can also be modulated continuously. The maximum change of phase difference is about 300°, making the device useful as a quarter-wave plate or a half-wave plate.

  16. Fabrication of large-scale multilevel phase-type Fresnel zone plate arrays by femtosecond laser direct writing

    NASA Astrophysics Data System (ADS)

    Yu, Yan-Hao; Tian, Zhen-Nan; Jiang, Tong; Niu, Li-Gang; Gao, Bing-Rong

    2016-03-01

    We report on the fabrication of large-scale eight-level phase-type Fresnel zone plate arrays (FZPAs) by femtosecond-laser direct writing technology. A high-speed galvanometer scanning system was used to fabricate each Fresnel zone plate to realize high fabrication efficiency. To overcome the limited fabrication scale in the case of galvanometer scanning, inter-plate movements were controlled by multi-axis air-bearing precise positioning stages. With the system, FZPAs whose fill-factor was designed to be 100% realized a diffraction efficiency of 89%. The focusing and imaging properties of the FZPAs were also evaluated, and the FZPAs showed high fidelity.

  17. Molecular evidence for the introgression between Hylobates lar and H. pileatus in the wild.

    PubMed

    Matsudaira, Kazunari; Reichard, Ulrich H; Malaivijitnond, Suchinda; Ishida, Takafumi

    2013-01-01

    Inter-specific hybrid zones for Hylobates gibbons are known in Southeast Asia. Among these, one hybrid zone between Hylobates lar and H. pileatus is located in Khao Yai National Park, Thailand. To find molecular evidence for the natural hybridization of the gibbons in this region, we studied mitochondrial DNA (mtDNA) of 68 gibbons of the H. lar phenotype living adjacent to the hybrid zone. Nucleotide sequencing of a fragment of mtDNA spanning hyper variable segment I showed that nine gibbons had an mtDNA haplotype of H. pileatus, and that seven of these nine gibbons belonged to a single maternal lineage over three generations. It is thus confirmed that introgression between H. lar and H. pileatus exists and the initial hybridization took place ages ago.

  18. 2- and 3-dimensional synthetic large-scale de novo patterning by mammalian cells through phase separation

    PubMed Central

    Cachat, Elise; Liu, Weijia; Martin, Kim C.; Yuan, Xiaofei; Yin, Huabing; Hohenstein, Peter; Davies, Jamie A.

    2016-01-01

    Synthetic biology provides an opportunity for the construction and exploration of alternative solutions to biological problems - solutions different from those chosen by natural life. To this end, synthetic biologists have built new sensory systems, cellular memories, and alternative genetic codes. There is a growing interest in applying synthetic approaches to multicellular systems, especially in relation to multicellular self-organization. Here we describe a synthetic biological system that confers large-scale de novo patterning activity on 2-D and 3-D populations of mammalian cells. Instead of using the reaction-diffusion mechanisms common in real embryos, our system uses cadherin-mediated phase separation, inspired by the known phenomenon of cadherin-based sorting. An engineered self-organizing, large-scale patterning system requiring no prior spatial cue may be a significant step towards the construction of self-assembling synthetic tissues. PMID:26857385

  19. Determining the Large-scale Environmental Dependence of Gas-phase Metallicity in Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Douglass, Kelly A.; Vogeley, Michael S.

    2017-01-01

    We study how the cosmic environment affects galaxy evolution in the universe by comparing the metallicities of dwarf galaxies in voids with dwarf galaxies in more dense regions. Ratios of the fluxes of emission lines, particularly those of the forbidden [O iii] and [S ii] transitions, provide estimates of a region’s electron temperature and number density. From these two quantities and the emission line fluxes [O ii] λ3727, [O iii] λ4363, and [O iii] λλ4959, 5007, we estimate the abundance of oxygen with the direct Te method. We estimate the metallicity of 42 blue, star-forming void dwarf galaxies and 89 blue, star-forming dwarf galaxies in more dense regions using spectroscopic observations from the Sloan Digital Sky Survey Data Release 7, as reprocessed in the MPA-JHU value-added catalog. We find very little difference between the two sets of galaxies, indicating little influence from the large-scale environment on their chemical evolution. Of particular interest are a number of extremely metal-poor dwarf galaxies that are less prevalent in voids than in the denser regions.

  20. Interventions to Increase Enrollment in a Large Multicenter Phase 3 Trial of Carotid Stenting versus Endarterectomy

    PubMed Central

    Longbottom, Mary E.; Roberts, Jamie N.; Tom, MeeLee; Hughes, Susan E.; Howard, Virginia J.; Sheffet, Alice J.; Meschia, James F.; Brott, Thomas G.

    2012-01-01

    Background Randomized clinical trials often encounter slow enrollment. Failing to meet sample size requirements has scientific, financial, and ethical implications. Aims We report interventions used to accelerate recruitment in a large multicenter clinical trial that was not meeting prespecified enrollment commitments. Methods The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) began randomization in December 2000. To accelerate enrollment, multiple recruitment tactics were initiated, which included expanding the number of sites; hiring a Recruitment Director (May 2003); broadening eligibility criteria (April 2005); branding with a study logo, website, and recruitment materials; increasing site visits by study leadership; sending emails to the site teams after every enrollment; distributing electronic newsletters; and implementing investigator and coordinator conferences. Results From December 2000 through May 2003, 14 sites became active (54 patients randomized); from June 2003 through April 2005, 44 sites were added (404 patients randomized); and from May 2005 through July 2008, 54 sites were added (2044 patients randomized). During these time intervals, the number of patients enrolled per site per year was 1.5, 3.6, and 5.6. For the single years 2004 to 2008, the mean monthly randomization rates per year were 19.7, 38.1, 56.4, 53.0, and 54.7 (annualized), respectively. Enrollment was highest after recruitment tactics were implemented: 677 patients in 2006, 636 in 2007, and 657 in 2008 (annualized). The prespecified sample size of 2502 patients, 47% asymptomatic, was accomplished July 2008. Conclusions Aggressive recruitment tactics and investment in a full-time Recruitment Director who can lead implementation may be effective in accelerating recruitment in multicenter trials. PMID:22631861

  1. External forces and torques generated by the brachiating white-handed gibbon (Hylobates lar).

    PubMed

    Chang, Y H; Bertram, J E; Lee, D V

    2000-10-01

    We compared the kinetics of brachiation to bipedal walking and running. Gibbons use pectoral limbs in continuous contact with their overhead support at slow speeds, but exhibit aerial phases (or ricochetal brachiation) at faster speeds. This basic interaction between limb and support suggests some analogy to walking and running. We quantified the forces in three axes and torque about the vertical axis generated by a brachiating White-handed gibbon (Hylobates lar) and compared them with bipedal locomotion. Handholds oriented perpendicular to the direction of travel (as in ladder rungs) were spaced 0.80, 1.20, 1.60, 1.72, 1.95, and 2.25 m apart. The gibbon proportionally matched forward velocity to stride length. Handhold reaction forces resembled ground reaction forces of running humans except that the order of horizontal braking and propulsion were reversed. Peak vertical forces in brachiation increased with speed as in bipedal locomotion. In contrast to bipedalism, however, peak horizontal forces changed little with speed. Gait transition occurred within the same relative velocity range as the walk-run transition in bipeds (Froude number = 0.3-0.6). We oriented handholds parallel to the direction of travel (as in a continuous pole) at 0.80 and 1.60 m spacings. In ricochetal brachiation, the gibbon generated greater torque with handholds oriented perpendicular as opposed to parallel to the direction of travel. Handhold orientation did not affect peak forces. The similarities and differences between brachiation and bipedalism offer insight into the ubiquity of mechanical principles guiding all limbed locomotion and the distinctiveness of brachiation as a unique mode of locomotion.

  2. Orthorhombic phases with large unit cells coexisting with the decagonal quasicrystal in an AlCoNiTb alloy

    SciTech Connect

    Yu, R.C. . Beijing Lab. of Electron Microscopy Jilin Univ., Changchun . Dept. of Physics); Li, X.Z.; Zhang, Z.; Kuo, K.H. . Beijing Lab. of Electron Microscopy); Xu, D.P.; Su, W.H. . Dept. of Physics)

    1994-11-15

    Elser and Henley suggested that if the irrational golden number [tau] = (1 + [radical]5)/2 associated with the three mutually orthogonal, equivalent twofold axes in an IQC (icosahedral quasicrystal) is approximated by a rational ratio of two consecutive Fibonacci numbers (0, 1, 1, 2, 3, 5, 8, [hor ellipsis], F[sub 0] = 0, F[sub 1] = 1, and F[sub n+1] = F[sub n] + F[sub n[minus]1]), such as F[sub n+1]/F[sub n] = 1/0, 1/1, 2/1, 3/2, 5/3, 8/5, [hor ellipsis], then a cubic crystalline phase generally called an approximant will result. Such an analysis has been extended later to 2-dimensional decagonal quasicrystals (DQCs). If the irradiation [tau] along two mutually orthogonal, non-equivalent, quasiperiodic twofold directions perpendicular to the periodic tenfold axis of a DQC is replaced by rational ratios F[sub n+1]/F[sub n], an orthorhombic approximant with a large unit cell will form. This not only explains the existing orthorhombic Al-TM (transitional metals) phases with large unit cells, such as Al[sub 60]Mn[sub 11]Ni[sub 4] and Al[sub 3]Mn, but also predicts many new approximants with even larger unit cells some of which have been found experimentally afterwards.

  3. Observations of Comet P/2003 T12 = 2012 A3 (SOHO) at large phase angle in STEREO-B

    NASA Astrophysics Data System (ADS)

    Hui, Man-To

    2014-11-01

    Comet P/2003 T12 = 2012 A3 (SOHO) was observed by the satellite STEREO-B during the period 2012 January 13-27. During its apparition, it ventured into the highest phase angle ever observed for a comet, and the forward-scattering enhancement in brightness was marked, as large as ˜8.5 mag. Therefore, it provided a precious opportunity to examine the compound Henyey-Greenstein (HG) comet-dust light-scattering model and it also offered valuable polarization data under an unprecedented observing geometry. Our analysis reveals that the compound HG model fits the observations very well until the phase angle exceeds ˜173°, where the brightness surge of the comet was obviously steeper than the prediction by the model. We have found that the reason for the greater steepness cannot be explained by contaminations from the proximal tail. Instead, the model of Mie spheres with radii greater than 1 μm, having a power-law distribution of power index ˜3, matches the observation very well, providing a best-fitting complex refractive index μ = 1.38 + i 0.006. The dust size was found to be consistent with the analysis of the comet's syndyne lines. The debiased polarization of the coma was ˜0 per cent in the phase angle range from 172.9° to 177.6°. No convincing evidence of temporal variation of the polarization was detected.

  4. Observations of Comet P/2003 T12 = 2012 A3 (SOHO) at large phase angle in STEREO-B

    NASA Astrophysics Data System (ADS)

    Hui, M.-T.

    2013-12-01

    Comet P/2003 T12 = 2012 A3 (SOHO) was observed by the satellite STEREO-B during the period 2012 January 13-27. During its apparition, it ventured into the highest phase angle ever observed for a comet, and the forward-scattering enhancement in brightness was marked, as large as ˜8.5 mag. Therefore, it provided a precious opportunity to examine the compound Henyey-Greenstein (HG) comet-dust light-scattering model and it also offered valuable polarization data under an unprecedented observing geometry. Our analysis reveals that the compound HG model fits the observations very well until the phase angle exceeds ˜173°, where the brightness surge of the comet was obviously steeper than the prediction by the model. We have found that the reason for the greater steepness cannot be explained by contaminations from the proximal tail. Instead, the model of Mie spheres with radii greater than 1 μm, having a power-law distribution of power index ˜3, matches the observation very well, providing a best-fitting complex refractive index μ = 1.38 + i 0.006. The dust size was found to be consistent with the analysis of the comet's syndyne lines. The debiased polarization of the coma was ˜0 per cent in the phase angle range from 172.9° to 177.6°. . No convincing evidence of temporal variation of the polarization was detected.

  5. Phasing the antennas of the Very Large Array (VLA) for reception of telemetry from Voyager 2 at Neptune encounter

    NASA Technical Reports Server (NTRS)

    Ulvestad, J. S.

    1988-01-01

    The Very Large Array (VLA) radio telescope is being instrumented at 8.4 GHz to receive telemetry from Voyager 2 during its encounter with Neptune in 1989. The procedure in which the 27 antennas have their phases adjusted in near real time so that the signals from the individual elements of the array can be added coherently is examined. Calculations of the expected signal to noise ratio, tests of the autophasing process at the VLA, and off-line simulations of that process are all presented. Various possible procedures for adjusting the phases are considered. It is shown that the signal to noise ratio at the VLA is adequate for summing the signals from the individual antennas with less than 0.1 dB of loss caused by imperfect coherence among the antennas. Tropospheric variations during the summer of 1989 could cause enough loss of coherence to make the losses higher than 0.1 dB. Experiments show that the losses caused by the troposphere can probably be kept below 0.2 dB if the time delay inherent in the phase adjustment process is no longer than approx. 5 secs. This relatively small combining loss meets the goal estabished to minimize the bit error rate in the Voyager telemetry and implies adequate autophasing of the VLA.

  6. A Large Liquid Argon TPC for Off-axis NuMI Neutrino Physics

    SciTech Connect

    Menary, Scott

    2006-07-11

    The ICARUS collaboration has shown the power of the liquid argon time projection chamber (LArTPC) technique to image events with bubble-chamber-like quality. I will describe a proposed long-baseline {nu}e appearance experiment utilizing a large ({>=} 15 kton1) LArTPC placed off-axis of Fermilab's NuMI {nu}{mu} beam. The total LArTPC program as it presently stands, which includes a number of smaller R and D projects designed to examine the key design issues, will be outlined.

  7. SER-LARS, Volume 3. Learning Objective History II. 1975-76 Edition.

    ERIC Educational Resources Information Center

    Montgomery County Intermediate Unit 23, Blue Bell, PA.

    The third of nine volumes in the SER-LARS (Special Education Resources Location Analysis and Retrieval System) series, a diagnostic-prescriptive instructional data bank for teachers of handicapped children, presents learning objectives organized by content descriptions. Entries give a history of the use of each objective along with information on…

  8. LAR receptor tyrosine phosphatases and HSPGs guide peripheral sensory axons to the skin

    PubMed Central

    Wang, Fang; Wolfson, Sean N.; Gharib, Arash; Sagasti, Alvaro

    2012-01-01

    Background Peripheral axons of somatosensory neurons innervate the skin early in development to detect touch stimuli. Embryological experiments had suggested that the skin produces guidance cues that attract sensory axons, but neither the attractants nor their neuronal receptors had previously been identified. Results To investigate peripheral axon navigation to the skin, we combined live imaging of developing zebrafish Rohon-Beard (RB) neurons with molecular loss-of-function manipulations. Simultaneously knocking down two members of the LAR family of receptor tyrosine phosphatases expressed in RB neurons, or inhibiting their function with dominant negative proteins, misrouted peripheral axons to internal tissues. Time-lapse imaging indicated that peripheral axon guidance, rather than outgrowth or maintenance, was defective in LAR deficient neurons. Peripheral axons displayed a similar misrouting phenotype in mutants defective in heparan sulfate proteoglycan (HSPG) production and avoided regions in which HSPGs were locally degraded. Conclusions HSPGs and LAR family receptors are required for sensory axon guidance to the skin. Together, our results support a model in which peripheral HSPGs are attractive ligands for LAR receptors on RB neurons. PMID:22326027

  9. Electron lifetime measurement using cosmic ray muons at the MicroBooNE LArTPC

    NASA Astrophysics Data System (ADS)

    Meddage, Varuna Crishan; MicroBooNE Collaboration

    2017-01-01

    MicroBooNE, a 170 ton liquid argon time projection chamber (LArTPC) located on the Fermilab's Booster Neutrino Beamline (BNB), is designed to both probe neutrino physics phenomena and further develop the LArTPC detector technology. MicroBooNE is the largest currently operating LArTPC detector and began collecting data in Fall 2015. LArTPCs are imaging detectors that offer exceptional capabilities for studying neutrinos. A fundamental requirement for the performance of such detectors is to maintain electronegative contaminants such as oxygen and water at extremely low concentrations, which otherwise can absorb the ionization electrons. The impurity levels in liquid argon can be estimated from the drift electron lifetime as they are inversely proportional to each other. This talk presents a measurement of the drift electron lifetime using cosmic ray muon data collected by MicroBooNE. An interpretation of the observed drift electron lifetime as a function of time indicates that the electron attenuation due to impurities in the liquid argon is negligible during normal operations, implying that the argon purification and gas recirculation system in MicroBooNE is performing successfully.

  10. SER-LARS, Volume 4. Learning Objective History III. 1975-76 Edition.

    ERIC Educational Resources Information Center

    Montgomery County Intermediate Unit 23, Blue Bell, PA.

    The fourth volume in the SER-LARS (Special Education Resources Location Analysis and Retrieval System) series, a diagnostic-prescriptive instructional data bank for teachers of handicapped children, presents a continuation of learning objectives organized by content descriptions. Entrees give a history of the use of each objective along with…

  11. Large-Scale Water-Vapor Two-Phase Flow Simulations in Advanced Light Water Reactor Cores

    SciTech Connect

    Hiroyuki, Yoshida; Kazuyuki, Takase; Hidesada, Tamai; Hajime, Akimoto; Yasuo, Ose

    2004-07-01

    Fluid flow characteristics in a fuel bundle of a reduced-moderation light water reactor (RMWR) with a tight-lattice core were analyzed numerically using a newly developed two-phase flow analysis code under the full bundle size condition. Conventional analysis methods such as subchannel codes need composition equations based on the experimental data. In case that there are no experimental data regarding to the thermal-hydraulics in the tight-lattice core, therefore, it is difficult to obtain high prediction accuracy on the thermal design of the RMWR. Then the large-scale direct numerical simulations with a super computer were chosen. The axial velocity distribution in a fuel bundle changed sharply around a spacer. Momentum transfer of vapor in a tight-lattice core is linear along the flow direction. The interface characteristics between water and vapor were clarified quantitatively. (authors)

  12. Large-scale phase separation with nano-twin domains in manganite spinel (Co,Fe,Mn)3O4

    NASA Astrophysics Data System (ADS)

    Horibe, Y.; Takeyama, S.; Mori, S.

    2016-08-01

    The effect of Mn concentration on the formation of nano-domain structures in the spinel oxide (Co,Fe,Mn)3O4 was investigated by electron diffraction, bright-, and dark-field imaging technique with transmission electron microscopy. Large scale phase separation with nano-twin domains was observed in Co0.6Fe1.0Mn1.4O4, in contrast to the highly aligned checkerboard nano-domains in Co0.6Fe0.9Mn1.5O4. Diffusion of the Mn3+ ions with the Jahn-Teller distortions is suggested to play an important role in the formation of checkerboard nano-domain structure.

  13. Detection of sources of periodic radio emission with the Large Phased Array of the Lebedev Physical Institute

    NASA Astrophysics Data System (ADS)

    Rodin, A. E.; Oreshko, V. V.; Samodurov, V. A.

    2017-01-01

    A method for searching for new periodic radio sources is described. The method is based on the spectral analysis of data from daily monitoring of the sky on the Large Phased Antenna (LPA) of the Pushchino Radio Astronomy Observatory at 111 MHz in a 2.5-MHz band. The 96-beam directivity pattern of the LPA is used. The signal is received in six 0.42-MHz frequency channels with a sampling rate of 0.1 s. The duration of the processed survey is four months. The particulars of detecting periodic sources with the LPA are considered. In total, 16 such radio sources have been detected, for which equatorial and Galactic coordinates, periods, and dispersion measures are given.

  14. A novel reconstruction method based on changes in phase for subsurface large sloped dielectric target using GPR

    NASA Astrophysics Data System (ADS)

    Zhou, Lijun; Ouyang, Shan; Liao, Guisheng

    2016-11-01

    In ground-penetrating radar (GPR) subsurface target reconstruction, various techniques based on amplitude (or energy) information of echoes from metal target with small size can work well. However, for environmental and geological applications, the quantitative analysis of the target's geometric features, like location, shape and size, is exactly what we are concerned about. Amplitude-based reconstruction method faces challenges in these applications. A large sloped target under the surface may lead to abundant virtual image energy and cause position deviation. In addition, the echoes from the inner part of the penetrable dielectric target may be too weak to be detected. However, changes in phase may highlight the effects of echoes from the target on that from the surroundings, even if the effect is small due to the weak energy. In this paper, a novel method based on changes in phase is proposed to reconstruct subsurface large sloped dielectric target. To remove the virtual image, the main idea is based on the geometric relationship between the recorded signal plotted beneath the receiving antenna and the reflected signal emanated from the target position which is "ahead" or "behind" of the receiving antenna. Furthermore, the electromagnetic (EM) wave propagating through the penetrable target will change its velocity and result in advancing or lagging related to the geometric shape of the target. In this case, the weak echoes from the back surface of the target can be compensated according to the advancing or lagging. With the proposed method, the virtual image is eliminated and both front and back surface of the target are reconstructed. Results from the laboratory experiments demonstrate the validity of the proposed method.

  15. Two-dimensional wave-number spectral analysis techniques for phase contrast imaging turbulence imaging data on large helical device

    SciTech Connect

    Michael, C. A.; Tanaka, K.; Kawahata, K.; Vyacheslavov, L.; Sanin, A.

    2015-09-15

    An analysis method for unfolding the spatially resolved wave-number spectrum and phase velocity from the 2D CO{sub 2} laser phase contrast imaging system on the large helical device is described. This is based on the magnetic shear technique which identifies propagation direction from 2D spatial Fourier analysis of images detected by a 6 × 8 detector array. Because the strongest modes have wave-number at the lower end of the instrumental k range, high resolution spectral techniques are necessary to clearly resolve the propagation direction and hence the spatial distribution of fluctuations along the probing laser beam. Multiple-spatial point cross-correlation averaging is applied before calculating the spatial power spectrum. Different methods are compared, and it is found that the maximum entropy method (MEM) gives best results. The possible generation of artifacts from the over-narrowing of spectra are investigated and found not to be a significant problem. The spatial resolution Δρ (normalized radius) around the peak wave-number, for conventional Fourier analysis, is ∼0.5, making physical interpretation difficult, while for MEM, Δρ ∼ 0.1.

  16. Phase field modeling of brittle fracture for enhanced assumed strain shells at large deformations: formulation and finite element implementation

    NASA Astrophysics Data System (ADS)

    Reinoso, J.; Paggi, M.; Linder, C.

    2017-02-01

    Fracture of technological thin-walled components can notably limit the performance of their corresponding engineering systems. With the aim of achieving reliable fracture predictions of thin structures, this work presents a new phase field model of brittle fracture for large deformation analysis of shells relying on a mixed enhanced assumed strain (EAS) formulation. The kinematic description of the shell body is constructed according to the solid shell concept. This enables the use of fully three-dimensional constitutive models for the material. The proposed phase field formulation integrates the use of the (EAS) method to alleviate locking pathologies, especially Poisson thickness and volumetric locking. This technique is further combined with the assumed natural strain method to efficiently derive a locking-free solid shell element. On the computational side, a fully coupled monolithic framework is consistently formulated. Specific details regarding the corresponding finite element formulation and the main aspects associated with its implementation in the general purpose packages FEAP and ABAQUS are addressed. Finally, the applicability of the current strategy is demonstrated through several numerical examples involving different loading conditions, and including linear and nonlinear hyperelastic constitutive models.

  17. Asymmetric masks for large field-of-view and high-energy X-ray phase contrast imaging

    NASA Astrophysics Data System (ADS)

    Endrizzi, M.; Astolfo, A.; Price, B.; Haig, I.; Olivo, A.

    2016-12-01

    We report on a large field of view, laboratory-based X-ray phase-contrast imaging setup. The method is based upon the asymmetric mask design that enables the retrieval of the absorption, refraction and scattering properties of the sample without the need to move any component of the imaging system. This can be thought of as a periodic repetition of a group of three (or more) apertures arranged in such a way that each laminar beam, defined by the apertures, produces a different illumination level when analysed with a standard periodic set of apertures. The sample is scanned through the imaging system, also removing possible aliasing problems that might arise from partial sample illumination when using the edge illumination technique. This approach preserves the incoherence and achromatic properties of edge illumination, removes the problems related to aliasing and it naturally adapts to those situations in clinical, industrial and security imaging where the image is acquired by scanning the sample relative to the imaging system. These concepts were implemented for a large field-of-view set of masks (20 cm × 1.5 cm and 15 cm × 1.2 cm), designed to work with a tungsten anode X-ray source operated up to 80-100 kVp, from which preliminary experimental results are presented.

  18. The Laminin–Nidogen Complex is a Ligand for a Specific Splice Isoform of the Transmembrane Protein Tyrosine Phosphatase LAR

    PubMed Central

    O'Grady, Pauline; Thai, Tran Cam; Saito, Haruo

    1998-01-01

    Leukocyte antigen–related protein (LAR) is a prototype for a family of transmembrane protein tyrosine phosphatases whose extracellular domain is composed of three Ig and several fibronectin type III (FnIII) domains. Complex alternative splicing of the LAR-FnIII domains 4–8 has been observed. The extracellular matrix laminin–nidogen complex was identified as a ligand for the LAR-FnIII domain 5 (Fn5) using a series of GST-LAR-FnIII domain fusion proteins and testing them in in vitro ligand-binding assays. LAR– laminin–nidogen binding was regulated by alternative splicing of a small exon within the LAR-Fn5 so that inclusion of this exon sequence resulted in disruption of the laminin–nidogen-binding activity. Long cellular processes were observed when HeLa cells were plated on laminin–nidogen, but not when plated on a fibronectin surface. Indirect immunofluorescent antibody staining revealed high expression of LAR in a punctate pattern, throughout the length of these cellular processes observed on laminin–nidogen. Antibody-induced cross-linking of LAR inhibited formation of these cellular processes, and inhibition was correlated with changes in cellular actin cytoskeletal structure. Thus, LAR–laminin–nidogen binding may play a role in regulating cell signaling induced by laminin–nidogen, resulting in cell morphological changes. PMID:9647658

  19. Unique Piezoelectric Properties of the Monoclinic Phase in Pb(Zr,Ti)O_{3} Ceramics: Large Lattice Strain and Negligible Domain Switching.

    PubMed

    Fan, Longlong; Chen, Jun; Ren, Yang; Pan, Zhao; Zhang, Linxing; Xing, Xianran

    2016-01-15

    The origin of the excellent piezoelectric properties at the morphotropic phase boundary is generally attributed to the existence of a monoclinic phase in various piezoelectric systems. However, there exist no experimental studies that reveal the role of the monoclinic phase in the piezoelectric behavior in phase-pure ceramics. In this work, a single monoclinic phase has been identified in Pb(Zr,Ti)O_{3} ceramics at room temperature by in situ high-energy synchrotron x-ray diffraction, and its response to electric field has been characterized for the first time. Unique piezoelectric properties of the monoclinic phase in terms of large intrinsic lattice strain and negligible domain switching have been observed. The extensional strain constant d_{33} and the transverse strain constant d_{31} are calculated to be 520 and -200  pm/V, respectively. These large piezoelectric coefficients are mainly due to the large intrinsic lattice strain, with very little extrinsic contribution from domain switching. The unique properties of the monoclinic phase provide new insights into the mechanisms responsible for the piezoelectric properties at the morphotropic phase boundary.

  20. Phase diagram of the binary H2O-NaCl and salty ice VII at pressure and temperature conditions of exoplanets and large icy moons

    NASA Astrophysics Data System (ADS)

    Journaux, B.; Daniel, I.

    2011-10-01

    We present here the first experimental data for the phase diagram of the H2O-NaCl system at high. Our results show a significant influence of NaCl on the phase diagram. A lot of NaCl is directly disolved into the dense ice phase. This would increase the depth of the solid phase transition inside large icy moons or super-earth exoplanets. These results may have major implication for astrophysical, geophysical and geodynamical modelisations of this water-rich planetary bodies.

  1. Intercomparison of Large-Eddy Simulations of Arctic Mixed-Phase Clouds: Importance of Ice Size Distribution Assumptions

    NASA Technical Reports Server (NTRS)

    Ovchinnikov, Mikhail; Ackerman, Andrew S.; Avramov, Alexander; Cheng, Anning; Fan, Jiwen; Fridlind, Ann M.; Ghan, Steven; Harrington, Jerry; Hoose, Corinna; Korolev, Alexei; McFarquhar, Greg M.; Morrison, Hugh; Paukert, Marco; Savre, Julien; Shipway, Ben J.; Shupe, Matthew D.; Solomon, Amy; Sulia, Kara

    2014-01-01

    Large-eddy simulations of mixed-phase Arctic clouds by 11 different models are analyzed with the goal of improving understanding and model representation of processes controlling the evolution of these clouds. In a case based on observations from the Indirect and Semi-Direct Aerosol Campaign (ISDAC), it is found that ice number concentration, Ni, exerts significant influence on the cloud structure. Increasing Ni leads to a substantial reduction in liquid water path (LWP), in agreement with earlier studies. In contrast to previous intercomparison studies, all models here use the same ice particle properties (i.e., mass-size, mass-fall speed, and mass-capacitance relationships) and a common radiation parameterization. The constrained setup exposes the importance of ice particle size distributions (PSDs) in influencing cloud evolution. A clear separation in LWP and IWP predicted by models with bin and bulk microphysical treatments is documented and attributed primarily to the assumed shape of ice PSD used in bulk schemes. Compared to the bin schemes that explicitly predict the PSD, schemes assuming exponential ice PSD underestimate ice growth by vapor deposition and overestimate mass-weighted fall speed leading to an underprediction of IWP by a factor of two in the considered case. Sensitivity tests indicate LWP and IWP are much closer to the bin model simulations when a modified shape factor which is similar to that predicted by bin model simulation is used in bulk scheme. These results demonstrate the importance of representation of ice PSD in determining the partitioning of liquid and ice and the longevity of mixed-phase clouds.

  2. Lars Onsager Prize Lecture: Statistical Dynamics of Disordered Systems

    NASA Astrophysics Data System (ADS)

    Fisher, Daniel S.

    2013-03-01

    The properties of many systems are strongly affected by quenched disorder that arose from their past history but is frozen on the time scales of interest. Although equilibrium phases and phase transitions in disordered materials can be very different from their counterparts in pure systems, the most striking phenomena involve non-equilibrium dynamics. The state of understanding of some of these will be reviewed including approach to equilibrium in spin glasses and the onset of motion in driven systems such as vortices in superconductors or earthquakes on geological faults. The potential for developing understanding of short-term evolutionary dynamics of microbial populations by taking advantage of the randomness of their past histories and the biological complexities will be discussed briefly.

  3. Intercomparison of Large-eddy Simulations of Arctic Mixed-phase Clouds: Importance of Ice Size Distribution Assumptions

    SciTech Connect

    Ovchinnikov, Mikhail; Ackerman, Andrew; Avramov, Alex; Cheng, Anning; Fan, Jiwen; Fridlind, Ann; Ghan, Steven J.; Harrington, Jerry Y.; Hoose, Corinna; Korolev, Alexei; McFarquhar, Greg; Morrison, H.; Paukert, Marco; Savre, Julien; Shipway, Ben; Shupe, Matthew D.; Solomon, Amy; Sulia, Kara

    2014-03-14

    Large-eddy simulations of mixed-phase Arctic clouds by 11 different models are analyzed with the goal of improving understanding and model representation of processes controlling the evolution of these clouds. In a case based on observations from the Indirect and Semi-Direct Aerosol Campaign (ISDAC), it is found that ice number concentration, Ni, exerts significant influence on the cloud structure. Increasing Ni leads to a substantial reduction in liquid water path (LWP) and potential cloud dissipation, in agreement with earlier studies. By comparing simulations with the same microphysics coupled to different dynamical cores as well as the same dynamics coupled to different microphysics schemes, it is found that the ice water path (IWP) is mainly controlled by ice microphysics, while the inter-model differences in LWP are largely driven by physics and numerics of the dynamical cores. In contrast to previous intercomparisons, all models here use the same ice particle properties (i.e., mass-size, mass-fall speed, and mass-capacitance relationships) and a common radiation parameterization. The constrained setup exposes the importance of ice particle size distributions (PSD) in influencing cloud evolution. A clear separation in LWP and IWP predicted by models with bin and bulk microphysical treatments is documented and attributed primarily to the assumed shape of ice PSD used in bulk schemes. Compared to the bin schemes that explicitly predict the PSD, schemes assuming exponential ice PSD underestimate ice growth by vapor deposition and overestimate mass-weighted fall speed leading to an underprediction of IWP by a factor of two in the considered case.

  4. A lattice Boltzmann method for incompressible two-phase flows on partial wetting surface with large density ratio

    NASA Astrophysics Data System (ADS)

    Yan, Y. Y.; Zu, Y. Q.

    2007-11-01

    This paper reports a new numerical scheme of the lattice Boltzmann method for calculating liquid droplet behaviour on particle wetting surfaces typically for the system of liquid-gas of a large density ratio. The method combines the existing models of Inamuro et al. [T. Inamuro, T. Ogata, S. Tajima, N. Konishi, A lattice Boltzmann method for incompressible two-phase flows with large density differences, J. Comput. Phys. 198 (2004) 628-644] and Briant et al. [A.J. Briant, P. Papatzacos, J.M. Yeomans, Lattice Boltzmann simulations of contact line motion in a liquid-gas system, Philos. Trans. Roy. Soc. London A 360 (2002) 485-495; A.J. Briant, A.J. Wagner, J.M. Yeomans, Lattice Boltzmann simulations of contact line motion: I. Liquid-gas systems. Phys. Rev. E 69 (2004) 031602; A.J. Briant, J.M. Yeomans, Lattice Boltzmann simulations of contact line motion: II. Binary fluids, Phys. Rev. E 69 (2004) 031603] and has developed novel treatment for partial wetting boundaries which involve droplets spreading on a hydrophobic surface combined with the surface of relative low contact angles and strips of relative high contact angles. The interaction between the fluid-fluid interface and the partial wetting wall has been typically considered. Applying the current method, the dynamics of liquid drops on uniform and heterogeneous wetting walls are simulated numerically. The results of the simulation agree well with those of theoretical prediction and show that the present LBM can be used as a reliable way to study fluidic control on heterogeneous surfaces and other wetting related subjects.

  5. High-intensity focused ultrasound with large scale spherical phased array for the ablation of deep tumors.

    PubMed

    Ji, Xiang; Bai, Jing-feng; Shen, Guo-feng; Chen, Ya-zhu

    2009-09-01

    Under some circumstances surgical resection is feasible in a low percentage for the treatment of deep tumors. Nevertheless, high-intensity focused ultrasound (HIFU) is beginning to offer a potential noninvasive alternative to conventional therapies for the treatment of deep tumors. In our previous study, a large scale spherical HIFU-phased array was developed to ablate deep tumors. In the current study, taking into account the required focal depth and maximum acoustic power output, 90 identical circular PZT-8 elements (diameter =1.4 cm and frequency=1 MHz) were mounted on a spherical shell with a radius of curvature of 18 cm and a diameter of 21 cm. With the developed array, computer simulations and ex vivo experiments were carried out. The simulation results theoretically demonstrate the ability of the array to focus and steer in the specified volume (a 2 cmx2 cmx3 cm volume) at the focal depth of 15 to 18 cm. Ex vivo experiment results also verify the capability of the developed array to ablate deep target tissue by either moving single focal point or generating multiple foci simultaneously.

  6. Monitoring of the turbulent solar wind with the upgraded Large Phased Array of the Lebedev Institute of Physics: First results

    NASA Astrophysics Data System (ADS)

    Shishov, V. I.; Chashei, I. V.; Oreshko, V. V.; Logvinenko, S. V.; Tyul'bashev, S. A.; Subaev, I. A.; Svidskii, P. M.; Lapshin, V. B.; Dagkesamanskii, R. D.

    2016-12-01

    The design properties and technical characteristics of the upgraded Large Phased Array (LPA) are briefly described. The results of an annual cycle of observations of interplanetary scintillations of radio sources on the LPA with the new 96-beam BEAM 3 system are presented. Within a day, about 5000 radio sources displaying second-timescale fluctuations in their flux densities due to interplanetary scintillations were observed. At present, the parameters of many of these radio sources are unknown. Therefore, the number of sources with root-mean-square flux-density fluctuations greater than 0.2 Jy in a 3° × 3° area of sky was used to characterize the scintillation level. The observational data obtained during the period of the maximum of solar cycle 24 can be interpreted using a three-component model for the spatial structure of the solar wind, consisting of a stable global component, propagating disturbances, and corotating structures. The global component corresponds to the spherically symmetric structure of the distribution of the turbulent interplanetary plasma. Disturbances propagating from the Sun are observed against the background of the global structure. Propagating disturbances recorded at heliocentric distances of 0.4-1 AU and at all heliolatitudes reach the Earth's orbit one to two days after the scintillation enhancement. Enhancements of ionospheric scintillations are observed during night-time. Corotating disturbances have a recurrence period of 27 d . Disturbances of the ionosphere are observed as the coronal base of a corotating structure approaches the western edge of the solar limb.

  7. First results of a large-area cryogenic gaseous photomultiplier coupled to a dual-phase liquid xenon TPC

    NASA Astrophysics Data System (ADS)

    Arazi, L.; Coimbra, A. E. C.; Erdal, E.; Israelashvili, I.; Rappaport, M. L.; Shchemelinin, S.; Vartsky, D.; dos Santos, J. M. F.; Breskin, A.

    2015-10-01

    We discuss recent advances in the development of cryogenic gaseous photomultipliers (GPM), for possible use in dark matter and other rare-event searches using noble-liquid targets. We present results from a 10 cm diameter GPM coupled to a dual-phase liquid xenon (LXe) TPC, demonstrating—for the first time—the feasibility of recording both primary (``S1'') and secondary (``S2'') scintillation signals. The detector comprised a triple Thick Gas Electron Multiplier (THGEM) structure with cesium iodide photocathode on the first element; it was shown to operate stably at 180 K with gains above 105, providing high single-photon detection efficiency even in the presence of large α particle-induced S2 signals comprising thousands of photoelectrons. S1 scintillation signals were recorded with a time resolution of 1.2 ns (RMS). The energy resolution (σ/E) for S2 electroluminescence of 5.5 MeV α particles was ~ 9%, which is comparable to that obtained in the XENON100 TPC with PMTs. The results are discussed within the context of potential GPM deployment in future multi-ton noble-liquid detectors.

  8. Experimental synchronization of chaos in a large ring of mutually coupled single-transistor oscillators: phase, amplitude, and clustering effects.

    PubMed

    Minati, Ludovico

    2014-12-01

    In this paper, experimental evidence of multiple synchronization phenomena in a large (n = 30) ring of chaotic oscillators is presented. Each node consists of an elementary circuit, generating spikes of irregular amplitude and comprising one bipolar junction transistor, one capacitor, two inductors, and one biasing resistor. The nodes are mutually coupled to their neighbours via additional variable resistors. As coupling resistance is decreased, phase synchronization followed by complete synchronization is observed, and onset of synchronization is associated with partial synchronization, i.e., emergence of communities (clusters). While component tolerances affect community structure, the general synchronization properties are maintained across three prototypes and in numerical simulations. The clusters are destroyed by adding long distance connections with distant notes, but are otherwise relatively stable with respect to structural connectivity changes. The study provides evidence that several fundamental synchronization phenomena can be reliably observed in a network of elementary single-transistor oscillators, demonstrating their generative potential and opening way to potential applications of this undemanding setup in experimental modelling of the relationship between network structure, synchronization, and dynamical properties.

  9. Experimental synchronization of chaos in a large ring of mutually coupled single-transistor oscillators: Phase, amplitude, and clustering effects

    SciTech Connect

    Minati, Ludovico E-mail: ludovico.minati@unitn.it

    2014-12-01

    In this paper, experimental evidence of multiple synchronization phenomena in a large (n = 30) ring of chaotic oscillators is presented. Each node consists of an elementary circuit, generating spikes of irregular amplitude and comprising one bipolar junction transistor, one capacitor, two inductors, and one biasing resistor. The nodes are mutually coupled to their neighbours via additional variable resistors. As coupling resistance is decreased, phase synchronization followed by complete synchronization is observed, and onset of synchronization is associated with partial synchronization, i.e., emergence of communities (clusters). While component tolerances affect community structure, the general synchronization properties are maintained across three prototypes and in numerical simulations. The clusters are destroyed by adding long distance connections with distant notes, but are otherwise relatively stable with respect to structural connectivity changes. The study provides evidence that several fundamental synchronization phenomena can be reliably observed in a network of elementary single-transistor oscillators, demonstrating their generative potential and opening way to potential applications of this undemanding setup in experimental modelling of the relationship between network structure, synchronization, and dynamical properties.

  10. Light-Based Triggering and Reconstruction of Michel Electrons in LArIAT

    SciTech Connect

    Foreman, W.

    2016-01-19

    The LArIAT Experiment aims to calibrate the liquid argon time projection chamber (LArTPC) using a beam of charged particles at the Fermilab Test Beam Facility. It is equipped with a novel scintillation light readout system using PMTs and custom SiPM preamplifier boards to detect light from reflector foils coated with wavelength-shifting TPB. A trigger on delayed secondary flashes of light captures events containing stopping cosmic muons together with the Michel electrons coming from their subsequent decay. This dedicated Michel trigger supplies an abundant sample of low-energy electrons throughout the detector's active volume, providing opportunities to study the combined calorimetric capabilities of the light system and the TPC. Preliminary results using scintillation light to study properties of the Michel electron sample are presented.

  11. A most distant intergeneric hybrid offspring (Larcon) of lesser apes, Nomascus leucogenys and Hylobates lar.

    PubMed

    Hirai, Hirohisa; Hirai, Yuriko; Domae, Hiroshi; Kirihara, Yoko

    2007-12-01

    Unlike humans, which are the sole remaining representatives of a once larger group of bipedal apes (hominins), the "lesser apes" (hylobatids) are a diverse radiation with numerous extant species. Consequently, the lesser apes can provide a valuable evolutionary window onto the possible interactions (e.g., interbreeding) of hominin lineages coexisting in the same time and place. In the present work, we employ chromosomal analyses to verify the hybrid ancestry of an individual (Larcon) produced by two of the most distant genera of lesser apes, Hylobates (lar-group gibbons) and Nomascus (concolor-group gibbons). In addition to a mixed pelage pattern, the hybrid animal carries a 48-chromosome karyotype that consists of the haploid complements of each parental species: Hylobates lar (n = 22) and Nomascus leucogenys leucogenys (n = 26). Studies of this animal's karyotype shed light onto the processes of speciation and genus-level divergence in the lesser apes and, by extension, across the Hominoidea.

  12. Non-closure of the surface energy balance explained by phase difference between vertical velocity and scalars of large atmospheric eddies

    NASA Astrophysics Data System (ADS)

    Gao, Zhongming; Liu, Heping; Katul, Gabriel G.; Foken, Thomas

    2017-03-01

    It is now accepted that large-scale turbulent eddies impact the widely reported non-closure of the surface energy balance when latent and sensible heat fluxes are measured using the eddy covariance method in the atmospheric surface layer (ASL). However, a mechanistic link between large eddies and non-closure of the surface energy balance remains a subject of inquiry. Here, measured 10 Hz time series of vertical velocity, air temperature, and water vapor density collected in the ASL are analyzed for conditions where entrainment and/or horizontal advection separately predominate. The series are decomposed into small- and large- eddies based on a frequency cutoff and their contributions to turbulent fluxes are analyzed. Phase difference between vertical velocity and water vapor density associated with large eddies reduces latent heat fluxes, especially in conditions where advection prevails. Enlarged phase difference of large eddies linked to entrainment or advection occurrence leads to increased residuals of the surface energy balance.

  13. Cerebral infarction and myocardial fibrosis in a white-handed gibbon (Hylobates lar).

    PubMed

    Borkowski, R; Taylor, T G; Rush, J

    2000-03-01

    A white-handed gibbon (Hylobates lar) lost the use of its right hand. Complete blood count, serum chemistry profile, electrocardiographic findings, blood pressure, and radiographic work-up were normal, but the gibbon died 2 days later. The gibbon was serologically positive for herpes simplex I and Epstein-Barr virus. Necropsy and histopathology showed acute infarction of the right cerebrum and multifocal to coalescing severe myocardial fibrosis.

  14. A study program on large aperture electronic scanning phased array antennas for the shuttle imaging microwave system

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Fundamental phased array theory and performance parameters are discussed in terms of their application to microwave radiometry, and four scanning phased arrays representing current examples of state-of-the-art phased array technology are evaluated for potential use as components of the multispectral antenna system for the space shuttle imaging microwave system (SIMS). A discussion of problem areas, both in performance and fabrication is included, with extrapolations of performance characteristics for phased array antennas of increased sizes up to 20 m by 20 m. The possibility of interlacing two or more phased arrays to achieve a multifrequency aperture is considered, and, finally, a specific antenna system is recommended for use with SIMS.

  15. Structure Formation in Solutions of Rigid Polymers Undergoing a Phase Transition

    DTIC Science & Technology

    1987-04-01

    order, and is thus intermediate between the isotropic fluid and crystalline solid phases. Early theories due to Onsager [11 and Isihara [2] were able...at the center. In particu- lar , the 2/1 helical conformations of PPA in its salts with Lithium and 0 Rubidium, having two phosphate groups in a repeat...to figure 6.2. Due to the inherent rigidity and relatively high molecu- lar weight of the PBT molecules, polymer and solvent mobility is ex- pected

  16. Upgraded Trigger Readout Electronics for the ATLAS LAr Calorimeters for Future LHC Running

    NASA Astrophysics Data System (ADS)

    Ma, Hong; ATLAS Liquid Argon Calorimeter Group

    2015-02-01

    The ATLAS Liquid Argon (LAr) calorimeters produce almost 200K signals that are digitized and processed by the front-end and back-end electronics for every triggered event. Additionally, the front-end electronics sums analog signals to provide coarse-grained energy sums to the first- level (L1) trigger system. The current design was optimized for the nominal LHC luminosity of 1034cm-2s-1. In order to retain the capability to trigger on low energy electrons and photons when the LHC is upgraded to higher luminosity, an improved LAr calorimeter trigger readout is proposed and being constructed. The new trigger readout system makes available the fine segmentation of the calorimeter at the L1 trigger with high precision in order to reduce the QCD jet background in electron, photon and tau triggers, and to improve jet and missing ET trigger performance. The new LAr Trigger Digitizer Board is designed to receive the higher granularity signals, digitize them on-detector and send them via fast optical links to a new Digital Processing System. The reconstructed energies of trigger readout channels after digital filtering are transmitted to the L1 system, allowing the extraction of improved trigger signatures. This contribution presents the motivation for the upgrade, the concept for the new trigger readout and the expected performance of the new trigger, and describes the components being developed for the new system.

  17. Mental health problems in adolescents with delayed sleep phase: results from a large population-based study in Norway.

    PubMed

    Sivertsen, Børge; Harvey, Allison G; Pallesen, Ståle; Hysing, Mari

    2015-02-01

    The aim of the current study was to compare mental health problems, resilience and family characteristics in adolescents with and without delayed sleep phase (DSP) in a population-based sample. Data were taken from the youth@hordaland-survey, a large population-based study in Hordaland County in Norway conducted in 2012. In all, 9338 adolescents aged 16-19 years (53.5% girls) provided self-reported data on a wide range of instruments assessing mental health symptoms, including depression, anxiety, obsessive-compulsive behaviours, attention deficit hyperactive disorder (ADHD) symptoms, perfectionism, resilience and sleep. Measures of socioeconomic status were also included. Three hundred and six adolescents (prevalence 3.3%) were classified as having DSP [according to the International Classification of Sleep Disorders-2 (ICSD-2)] criteria. Adolescents with DSP reported higher levels of depression, anxiety and ADHD symptoms. Adolescents with DSP also exhibited significantly lower levels of resilience. The Cohen's d effect sizes ranged from small [obsessive-compulsive disorder (OCD): d = 0.15] to moderate (inattention: d = 0.71). In the fully adjusted model, the significant predictors of DSP included inattention [odds ratio (OR): 2.11], lack of personal structure (OR: 2.07), low (OR: 1.85) and high (OR: 1.91) paternal education, parents not living together (OR: 1.81), hyperactivity/inattention (OR: 1.71) and poorer family economy (OR: 1.59). In conclusion, the high symptom load across a range of mental health measures suggests that a broad and thorough clinical approach is warranted when adolescents present with DSP.

  18. Large-scale deformed quasiparticle random-phase approximation calculations of the γ -ray strength function using the Gogny force

    NASA Astrophysics Data System (ADS)

    Martini, M.; Péru, S.; Hilaire, S.; Goriely, S.; Lechaftois, F.

    2016-07-01

    Valuable theoretical predictions of nuclear dipole excitations in the whole chart are of great interest for different nuclear applications, including in particular nuclear astrophysics. Here we present large-scale calculations of the E 1 γ -ray strength function obtained in the framework of the axially symmetric deformed quasiparticle random-phase approximation based on the finite-range Gogny force. This approach is applied to even-even nuclei, the strength function for odd nuclei being derived by interpolation. The convergence with respect to the adopted number of harmonic oscillator shells and the cutoff energy introduced in the 2-quasiparticle (2 -q p ) excitation space is analyzed. The calculations performed with two different Gogny interactions, namely D1S and D1M, are compared. A systematic energy shift of the E 1 strength is found for D1M relative to D1S, leading to a lower energy centroid and a smaller energy-weighted sum rule for D1M. When comparing with experimental photoabsorption data, the Gogny-QRPA predictions are found to overestimate the giant dipole energy by typically ˜2 MeV. Despite the microscopic nature of our self-consistent Hartree-Fock-Bogoliubov plus QRPA calculation, some phenomenological corrections need to be included to take into account the effects beyond the standard 2 -q p QRPA excitations and the coupling between the single-particle and low-lying collective phonon degrees of freedom. For this purpose, three prescriptions of folding procedure are considered and adjusted to reproduce experimental photoabsorption data at best. All of them are shown to lead to somewhat similar predictions of the E 1 strength, both at low energies and for exotic neutron-rich nuclei. Predictions of γ -ray strength functions and Maxwellian-averaged neutron capture rates for the whole Sn isotopic chain are also discussed and compared with previous theoretical calculations.

  19. High-speed horizontal-path atmospheric turbulence correction using a large actuator-number MEMS spatial light modulator in an interferometric phase conjugation engine

    SciTech Connect

    Baker, K; Stappaerts, E; Gavel, D; Wilks, S; Tucker, J; Silva, D; Olsen, J; Olivier, S; Young, P; Kartz, M; Flath, L; Kruelivitch, P; Crawford, J; Azucena, O

    2004-03-04

    Atmospheric propagation results for a high-speed, large-actuator-number, adaptive optics system are presented. The system uses a MEMS-based spatial light modulator correction device with 1024 actuators. Tests over a 1.35 km path achieved correction speeds in excess of 800 Hz and Strehl ratios close to 0.5. The wave-front sensor was based on a quadrature interferometer that directly measures phase. This technique does not require global wave-front reconstruction, making it relatively insensitive to scintillation and phase residues. The results demonstrate the potential of large actuator number MEMS-based spatial light modulators to replace conventional deformable mirrors.

  20. MicroBooNE and the Road to Large Liquid Argon Neutrino Detectors

    NASA Astrophysics Data System (ADS)

    Karagiorgi, G.

    Liquid Argon Time Projection Chambers (LArTPC's) provide a promising technology for multi-kiloton scale detectors aiming to address-among other pressing particle physics questions-the possibility of short and long baseline electron neutrino and antineutrino appearance. MicroBooNE, a 170 ton LArTPC under construction, is the next necessary step in a phased R&D effort toward construction and stable operation of larger-scale LArTPC's. This development effort also leans heavily on the ArgoNeuT and LAr1 LArTPC R&D experiments at Fermilab. In addition to advancing the LArTPC technology, these projects also provide unique physics opportunities. For example, Micro-BooNE will be located in the Booster Neutrino Beamline at Fermilab, at ∼470 m from neutrino production. Thus, in addition to measuring a suite of low energy neutrino cross sections on argon, MicroBooNE will investigate the anomalous low energy excess seen by the MiniBooNE experiment. Furthermore, the neutrino beam energy and relatively short baseline provide MicroBooNE with sensitivity to high-∼m2 neutrino oscillations. These proceedings summarize the role of the MicroBooNE detector in the US LArTPC R&D program, present its physics reach, and briefly discuss the physics potential of a dedicated near-future neutrino oscillation program at the Booster Neutrino Beamline, as a way to maximize the physics output of the Fermilab LArTPC R&D projects.

  1. Anatomical failure following laparoscopic antireflux surgery (LARS); does it really matter?

    PubMed Central

    Dunne, N; Stratford, J; Jones, L; Sohampal, J; Robertson, R; Booth, MI; Dehn, TCB

    2010-01-01

    INTRODUCTION Failure rates of laparoscopic antireflux surgery (LARS) vary from 2–30%. A degree of anatomical failure is common, and the most common failure is intrathoracic wrap herniation. We have assessed anatomical integrity of the crural repair and wrap using marking Liga clips placed at the time of surgery and compared this with symptomatic outcome. PATIENTS AND METHODS A prospective study was undertaken on 50 patients who underwent LARS in a single centre over a 3-year period. Each had an X-ray on the first postoperative day and a barium swallow at 6 months at which the distance was measured between the marking Liga clips. An increase in interclip distance of > 25–49% was deemed ‘mild separation’, and an increase of > 50% ‘moderate separation’. Patients completed a standardised symptom questionnaire at 6 months. RESULTS At 6 months' postoperatively, 22% had mild separation of the crural repair with a mean Visick score of 1.18, and 54% had moderate separation with a mean Visick score of 1.26. Mild separation of the wrap occurred in 28% with a mean Visick score of 1.21 and 22% moderate separation with a mean Visick score of 1.18. Three percent had mild separation of both the crural repair and wrap with a mean Visick score of 1.0, and 16% moderate separation with a mean Visick score of 1.13. Of patients, 14% had evidence of some degree of failure on barium swallow but only one of these was significant intrathoracic migration of the wrap which was symptomatic and required re-do surgery. CONCLUSIONS The prevalence of some form of anatomical failure, as determined by an increase in the interclip distance, is high at 6 months' postoperatively following LARS. However, this does not seem to correlate with a subjective recurrence of symptoms. PMID:19995487

  2. Simulation of phase separation with large component ratio for oil-in-water emulsion in ultrasound field.

    PubMed

    Wang, Heping; Li, Xiaoguang; Li, Yanggui; Geng, Xingguo

    2017-05-01

    This paper presents an exploration for separation of oil-in-water and coalescence of oil droplets in ultrasound field via lattice Boltzmann method. Simulations were conducted by the ultrasound traveling and standing waves to enhance oil separation and trap oil droplets. The focus was to the effect of ultrasound irradiation on oil-in-water emulsion properties in the standing wave field, such as oil drop radius, morphology and growth kinetics of phase separation. Ultrasound fields were applied to irradiate the oil-in-water emulsion for getting flocculation of the oil droplets in 420kHz case, and larger dispersed oil droplets and continuous phases in 2MHz and 10MHz cases, respectively. The separated phases started to rise along the direction of sound propagation after several periods. The rising rate of the flocks was significantly greater in ultrasound case than that of oil droplets in the original emulsion, indicating that ultrasound irradiation caused a rapid increase of oil droplet quantity in the progress of the separation. The separation degree was also significantly improved with increasing frequency or irradiation time. The dataset was rearranged for growth kinetics of ultrasonic phase separation in a plot by spherically averaged structure factor and the ratio of oil and emulsion phases. The analyses recovered the two different temporal regimes: the spinodal decomposition and domain growth stages, which further quantified the morphology results. These numerical results provide guidance for setting the optimum condition for the separation of oil-in-water emulsion in the ultrasound field.

  3. SN-detection in LAr-TPC and the quest for (ν-Ar) cross sections

    SciTech Connect

    Cavanna, F.

    2015-05-15

    Neutrino-nucleus cross sections are of relevance to supernova astrophysics. These cross-sections can be grouped into three categories, those that affect supernova dynamics, supernova nucleosynthesis, and terrestrial supernova neutrino detection, each of which would benefit from experimental study. In this report only the relevance of an accurate knowledge of neutrino-target nucleus cross sections for SN detection will be discussed, in particular for the case of Argon, the active target material of LAr-TPC detectors currently under construction or proposed for future very massive underground experiments.

  4. Anomalous large electrical capacitance of planar microstructures with vanadium dioxide films near the insulator-metal phase transition

    SciTech Connect

    Aliev, V. Sh. Bortnikov, S. G.; Badmaeva, I. A.

    2014-03-31

    The temperature dependence of electrical capacitance of planar microstructures with vanadium dioxide (VO{sub 2}) film near the insulator-metal phase transition has been investigated at the frequency of 1 MHz. Electrical capacitance measurements of the microstructures were performed by the technique based on the using of a two-terminal resistor-capacitor module simulating the VO{sub 2} layer behavior at the insulator-metal phase transition. At temperatures 325–342 K, the anomalous increase in microstructures capacitance was observed. Calculation of electric field in the microstructure showed that VO{sub 2} relative permittivity (ε) reaches ∼10{sup 8} at the percolation threshold. The high value of ε can be explained by the fractal nature of the interface between metal and insulator clusters formed near the insulator-metal phase transition.

  5. Phase diagram of a one-dimensional spin-full Bose-Fermi mixture at large boson densities

    NASA Astrophysics Data System (ADS)

    Nocera, Alberto; Lutchyn, Roman M.; Feiguin, Adrian E.

    2014-03-01

    We determine the ground state phase diagram of a one dimensional Bose-Fermi Hubbard model with spin-full fermions using the Density Matrix Renormalization Group (DMRG) method. We focus on the regime with one fermion per site, and deep into the superfluid phase. We study the effects of the boson-fermion interaction on the fermionic pairing, as a function of the interaction strength, hopping, and bosonic density. We identify the regime in which fermionic superfluidity dominates, and a phase with coexisting CDW and bosonic superfluidity. At high boson densities we find a fermionic Wigner crystal coexisting with bosonic superfluidity. We analyze the structure of the Cooper pairs and the bosonic cloud that acts as the glue.

  6. Phase-matched waveguide four-wave mixing scaled to higher peak powers with large-core-area hollow photonic-crystal fibers.

    PubMed

    Konorov, S O; Serebryannikov, E E; Fedotov, A B; Miles, R B; Zheltikov, A M

    2005-05-01

    Hollow photonic-crystal fibers with large core diameters are shown to allow waveguide nonlinear-optical interactions to be scaled to higher pulse peak powers. Phase-matched four-wave mixing is predicted theoretically and demonstrated experimentally for millijoule nanosecond pulses propagating in a hollow photonic-crystal fiber with a core diameter of about 50 microm , suggesting the way to substantially enhance the efficiency of nonlinear-optical spectral transformations and wave mixing of high-power laser pulses in the gas phase.

  7. SCORPIO: A Scalable Two-Phase Parallel I/O Library With Application To A Large Scale Subsurface Simulator

    SciTech Connect

    Sreepathi, Sarat; Sripathi, Vamsi; Mills, Richard T; Hammond, Glenn; Mahinthakumar, Kumar

    2013-01-01

    Inefficient parallel I/O is known to be a major bottleneck among scientific applications employed on supercomputers as the number of processor cores grows into the thousands. Our prior experience indicated that parallel I/O libraries such as HDF5 that rely on MPI-IO do not scale well beyond 10K processor cores, especially on parallel file systems (like Lustre) with single point of resource contention. Our previous optimization efforts for a massively parallel multi-phase and multi-component subsurface simulator (PFLOTRAN) led to a two-phase I/O approach at the application level where a set of designated processes participate in the I/O process by splitting the I/O operation into a communication phase and a disk I/O phase. The designated I/O processes are created by splitting the MPI global communicator into multiple sub-communicators. The root process in each sub-communicator is responsible for performing the I/O operations for the entire group and then distributing the data to rest of the group. This approach resulted in over 25X speedup in HDF I/O read performance and 3X speedup in write performance for PFLOTRAN at over 100K processor cores on the ORNL Jaguar supercomputer. This research describes the design and development of a general purpose parallel I/O library, SCORPIO (SCalable block-ORiented Parallel I/O) that incorporates our optimized two-phase I/O approach. The library provides a simplified higher level abstraction to the user, sitting atop existing parallel I/O libraries (such as HDF5) and implements optimized I/O access patterns that can scale on larger number of processors. Performance results with standard benchmark problems and PFLOTRAN indicate that our library is able to maintain the same speedups as before with the added flexibility of being applicable to a wider range of I/O intensive applications.

  8. Unusual Emissions at Various Energies Prior to the Impulsive Phase of the Large Solar Flare and Coronal Mass Ejection of 4 November 2003

    NASA Technical Reports Server (NTRS)

    Kaufmann, Pierre; Holman, Gordon D.; Su, Yang; de Castro, C. Guillermo Gimenez; Correia, Emilia; Fernandes, Luis O. T.; de Souza, Rodney V.; Marun, Adolfo; Pereyra, Pablo

    2012-01-01

    The GOES X28 flare of 4 November 2003 was the largest ever recorded in its class. It produced the first evidence for two spectrally separated emission components, one at microwaves and the other in the THz range of frequencies.We analyzed the pre-flare phase of this large flare, twenty minutes before the onset of the major impulsive burst. This periodis characterized by unusual activity in X-rays, sub-THz frequencies, H, and microwaves.The CME onset occurred before the onset of the large burst by about 6 min.

  9. Impact of tissue atrophy on high-pass filtered MRI signal phase-based assessment in large-scale group-comparison studies: A simulation study

    NASA Astrophysics Data System (ADS)

    Schweser, Ferdinand; Dwyer, Michael G.; Deistung, Andreas; Reichenbach, Jürgen R.; Zivadinov, Robert

    2013-10-01

    The assessment of abnormal accumulation of tissue iron in the basal ganglia nuclei and in white matter plaques using the gradient echo magnetic resonance signal phase has become a research focus in many neurodegenerative diseases such as multiple sclerosis or Parkinson’s disease. A common and natural approach is to calculate the mean high-pass-filtered phase of previously delineated brain structures. Unfortunately, the interpretation of such an analysis requires caution: in this paper we demonstrate that regional gray matter atrophy, which is concomitant with many neurodegenerative diseases, may itself directly result in a phase shift seemingly indicative of increased iron concentration even without any real change in the tissue iron concentration. Although this effect is relatively small results of large-scale group comparisons may be driven by anatomical changes rather than by changes of the iron concentration.

  10. Effects of Mg(2+) on in vivo transcriptional dynamics of the lar promoter.

    PubMed

    Kandhavelu, Meenakshisundaram; Lihavainen, Eero; Muthukrishnan, Anantha Barathi; Yli-Harja, Olli; Ribeiro, Andre Sanches

    2012-03-01

    In vitro studies show that the transcriptional dynamics in Escherichia coli is sensitive to Mg(2+) concentration in the cell. We study in vivo how Mg(2+) affects the production of RNA molecules under the control of the lar promoter, P(lar), a lac promoter variant. The target RNA codes for RFP followed by 96 MS2d-GFP binding sites, allowing in vivo detection of individual RNA molecules following transcription. As Mg(2+) concentration is increased, transcripts' production first increases, but then decreases. Results were confirmed by qPCR and gel assay. Analysis of cell to cell diversity in RNA production shows that the variance of RNA numbers changes with Mg(2+). Gel assay confirms changes in the structure of the target RNA. These results suggest that changes in the dynamics of elongation may also affect RNA production, along with changes in the dynamics of the promoter open complex. The findings suggest that changes in metabolite concentration can have multiple, complex effects on the in vivo dynamics of transcription. Comparative analysis of the effects on the dynamics of transcription of other metabolites confirms the significance of the effects of Mg(2+) ions. Namely, we show that Ca(2+) and Fe(2+) have almost negligible effects in comparison to Mg(2+).

  11. Development of COTS ADC SEE Test System for the ATLAS LArCalorimeter Upgrade

    DOE PAGES

    Hu, Xue -Ye; Chen, Hu -Cheng; Chen, Kai; ...

    2014-12-01

    Radiation-tolerant, high speed, high density and low power commercial off-the-shelf (COTS) analog-to-digital converters (ADCs) are planned to be used in the upgrade to the Liquid Argon (LAr) calorimeter front end (FE) trigger readout electronics. Total ionization dose (TID) and single event effect (SEE) are two important radiation effects which need to be characterized on COTS ADCs. In our initial TID test, Texas Instruments (TI) ADS5272 was identified to be the top performer after screening a total 17 COTS ADCs from different manufacturers with dynamic range and sampling rate meeting the requirements of the FE electronics. Another interesting feature of ADS5272more » is its 6.5 clock cycles latency, which is the shortest among the 17 candidates. Based on the TID performance, we have designed a SEE evaluation system for ADS5272, which allows us to further assess its radiation tolerance. In this paper, we present a detailed design of ADS5272 SEE evaluation system and show the effectiveness of this system while evaluating ADS5272 SEE characteristics in multiple irradiation tests. According to TID and SEE test results, ADS5272 was chosen to be implemented in the full-size LAr Trigger Digitizer Board (LTDB) demonstrator, which will be installed on ATLAS calorimeter during the 2014 Long Shutdown 1 (LS1).« less

  12. Development of COTS ADC SEE Test System for the ATLAS LArCalorimeter Upgrade

    SciTech Connect

    Hu, Xue -Ye; Chen, Hu -Cheng; Chen, Kai; Mead, Joseph; Liu, Shu -Bin; An, Qi

    2014-12-01

    Radiation-tolerant, high speed, high density and low power commercial off-the-shelf (COTS) analog-to-digital converters (ADCs) are planned to be used in the upgrade to the Liquid Argon (LAr) calorimeter front end (FE) trigger readout electronics. Total ionization dose (TID) and single event effect (SEE) are two important radiation effects which need to be characterized on COTS ADCs. In our initial TID test, Texas Instruments (TI) ADS5272 was identified to be the top performer after screening a total 17 COTS ADCs from different manufacturers with dynamic range and sampling rate meeting the requirements of the FE electronics. Another interesting feature of ADS5272 is its 6.5 clock cycles latency, which is the shortest among the 17 candidates. Based on the TID performance, we have designed a SEE evaluation system for ADS5272, which allows us to further assess its radiation tolerance. In this paper, we present a detailed design of ADS5272 SEE evaluation system and show the effectiveness of this system while evaluating ADS5272 SEE characteristics in multiple irradiation tests. According to TID and SEE test results, ADS5272 was chosen to be implemented in the full-size LAr Trigger Digitizer Board (LTDB) demonstrator, which will be installed on ATLAS calorimeter during the 2014 Long Shutdown 1 (LS1).

  13. Resistance to octreotide LAR in acromegalic patients with high SSTR2 expression: analysis of AIP expression.

    PubMed

    Kasuki, Leandro; Colli, Leandro M; Elias, Paula C L; Castro, Margaret de; Gadelha, Mônica R

    2012-11-01

    We present here the clinical and molecular data of two patients with acromegaly treated with octreotide LAR after non-curative surgery, and who presented different responses to therapy. Somatostatin receptor type 2 and 5 (SSTR2 and SSTR5), and aryl hydrocarbon receptor-interacting protein (AIP) expression levels were analyzed by qPCR. In both cases, high SSTR2 and low SSTR5 expression levels were detected; however, only one of the patients achieved disease control after octreotide LAR therapy. When we analyzed AIP expression levels of both cases, the patient whose disease was controlled after therapy exhibited AIP expression levels that were two times higher than the patient whose disease was still active. These two cases illustrate that, although the currently available somatostatin analogs bind preferentially to SSTR2, some patients are not responsive to therapy despite high expression of this receptor. This difference could be explained by differences in post-receptor signaling pathways, including the recently described involvement of AIP.

  14. [Effects of exenatide lar in type 2 diabetes mellitus and obesity].

    PubMed

    Sierra Poyatos, Roberto; Riobó Serván, Pilar; Vázquez Martínez, Clotilde

    2014-10-24

    Introducción: Los análogos GLP-1 han demostrado ser un tratamiento eficaz en el tratamiento de la diabetes mellitus tipo 2 (DM-2) y la obesidad. Objetivo: Evaluar la eficacia de exenatide LAR sobre la pérdida de peso, control glucémico, tensión arterial (TA) y perfil lipídico, en DM-2 y obesidad. Material y métodos: Estudio retrospectivo de pacientes en tratamiento con exenatide LAR durante 6 meses. Se recogieron datos demográficos (edad, sexo), antropométricos, glucemia basal, hemoglobina glicada (HbA1c), tensión arterial y perfil lipídico al inicio y a los 6 meses de tratamiento. Se ha realizado un análisis de regresión logística para evaluar posibles factores predictores de eficacia. Resultados: 30 pacientes (17 varones, edad media: 61,7±9,5 años) con DM-2 de 9,7±6,2 años de evolución. La HbA1c se redujo en 1,3% (IC95% 1,04-1,57, p.

  15. Ultrasonic Phased Array Sound Field Mapping Through Large-Bore Coarse Grained Cast Austenitic Stainless Steel (CASS) Piping Materials

    SciTech Connect

    Cinson, Anthony D.; Crawford, Susan L.; Prowant, Matthew S.; Diaz, Aaron A.; Hathaway, John E.; Anderson, Michael T.

    2012-04-16

    A sound field beam mapping exercise was conducted to further understand the effects of coarse grained microstructures found in CASS materials on phased array ultrasonic wave propagation. Laboratory measurements were made on three CASS specimens with different microstructures; the specimens were polished and etched to reveal measurable grain sizes, shapes and orientations. Three longitudinal, phased array probes were fixed on a specimen's outside diameter with the sound field directed toward one end (face) of the pipe segment over a fixed range of angles. A point receiver was raster scanned over the surface of the specimen face generating a sound field image. A slice of CASS material was then removed from the specimen end and the beam mapping exercise repeated. The sound fields acquired were analyzed for spot size, coherency, and beam redirection. Analyses were conducted between the resulting sound fields and the microstructural characteristics of each specimen.

  16. SISGR -- Domain Microstructures and Mechanisms for Large, Reversible and Anhysteretic Strain Behaviors in Phase Transforming Ferroelectric Materials

    SciTech Connect

    Wang, Yu U.

    2013-12-06

    This four-year project (including one-year no-cost extension) aimed to advance fundamental understanding of field-induced strain behaviors of phase transforming ferroelectrics. We performed meso-scale phase field modeling and computer simulation to study domain evolutions, mechanisms and engineering techniques, and developed computational techniques for nanodomain diffraction analysis; to further support above originally planned tasks, we also carried out preliminary first-principles density functional theory calculations of point defects and domain walls to complement meso-scale computations as well as performed in-situ high-energy synchrotron X-ray single crystal diffraction experiments to guide theoretical development (both without extra cost to the project thanks to XSEDE supercomputers and DOE user facility Advanced Photon Source).

  17. Suppression of thermoelectric Thomson effect in silicon microwires under large electrical bias and implications for phase-change memory devices

    NASA Astrophysics Data System (ADS)

    Bakan, Gokhan; Gokirmak, Ali; Silva, Helena

    2014-12-01

    We have observed how thermoelectric effects that result in asymmetric melting of silicon wires are suppressed for increasing electric current density (J). The experimental results are investigated using numerical modeling of the self-heating process, which elucidates the relative contributions of the asymmetric thermoelectric Thomson heat (˜J) and symmetric Joule heating (˜J2) that lead to symmetric heating for higher current levels. These results are applied in modeling of the self-heating process in phase-change memory devices. While, phase-change memory devices show a clearly preferred operation polarity due to thermoelectric effects, nearly symmetric operation can be achieved with higher amplitude and shorter current pulses, which can lead to design of improved polarity-invariant memory circuitry.

  18. Large time behavior for the system of a viscous liquid-gas two-phase flow model in R3

    NASA Astrophysics Data System (ADS)

    Wang, Wenjun; Wang, Weike

    2016-11-01

    The Cauchy problem of a three-dimensional compressible viscous liquid-gas two-phase flow model is considered in the present paper. The global existence and uniqueness of solutions are established when the initial data is close to its equilibrium in the framework of Sobolev space H3 (R3). Moreover, the optimal L2-L2 convergence rates are also obtained for the solution.

  19. Dual-phase steel sheets under cyclic tension-compression to large strains: Experiments and crystal plasticity modeling

    NASA Astrophysics Data System (ADS)

    Zecevic, Milovan; Korkolis, Yannis P.; Kuwabara, Toshihiko; Knezevic, Marko

    2016-11-01

    In this work, we develop a physically-based crystal plasticity model for the prediction of cyclic tension-compression deformation of multi-phase materials, specifically dual-phase (DP) steels. The model is elasto-plastic in nature and integrates a hardening law based on statistically stored dislocation density, localized hardening due to geometrically necessary dislocations (GNDs), slip-system-level kinematic backstresses, and annihilation of dislocations. The model further features a two level homogenization scheme where the first level is the overall response of a two-phase polycrystalline aggregate and the second level is the homogenized response of the martensite polycrystalline regions. The model is applied to simulate a cyclic tension-compression-tension deformation behavior of DP590 steel sheets. From experiments, we observe that the material exhibits a typical decreasing hardening rate during forward loading, followed by a linear and then a non-linear unloading upon the load reversal, the Bauschinger effect, and changes in hardening rate during strain reversals. To predict these effects, we identify the model parameters using a portion of the measured data and validate and verify them using the remaining data. The developed model is capable of predicting all the particular features of the cyclic deformation of DP590 steel, with great accuracy. From the predictions, we infer and discuss the effects of GNDs, the backstresses, dislocation annihilation, and the two-level homogenization scheme on capturing the cyclic deformation behavior of the material.

  20. Direct simulation of phase delay effects on induced-charge electro-osmosis under large ac electric fields

    NASA Astrophysics Data System (ADS)

    Sugioka, Hideyuki

    2016-08-01

    The standard theory of induced-charge electro-osmosis (ICEO) often overpredicts experimental values of ICEO velocities. Using a nonsteady direct multiphysics simulation technique based on the coupled Poisson-Nernst-Planck and Stokes equations for an electrolyte around a conductive cylinder subject to an ac electric field, we find that a phase delay effect concerning an ion response provides a fundamental mechanism for electrokinetic suppression. A surprising aspect of our findings is that the phase delay effect occurs even at much lower frequencies (e.g., 50 Hz) than the generally believed charging frequency of an electric double layer (typically, 1 kHz) and it can decrease the electrokinetic velocities in one to several orders. In addition, we find that the phase delay effect may also cause a change in the electrokinetic flow directions (i.e., flow reversal) depending on the geometrical conditions. We believe that our findings move toward a more complete understanding of complex experimental nonlinear electrokinetic phenomena.

  1. Isolation and characterization of genes encoding leucoanthocyanidin reductase (FeLAR) and anthocyanidin reductase (FeANR) in buckwheat (Fagopyrum esculentum).

    PubMed

    Matsui, Katsuhiro; Hisano, Tomomi; Yasui, Yasuo; Mori, Masashi; Walker, Amanda R; Morishita, Toshikazu; Katsu, Kenjiro

    2016-10-20

    Proanthocyanidins (PAs) are a major group of flavonoids synthesized via the phenylpropanoid biosynthesis pathway, however the pathway has not been fully characterized in buckwheat. Anthocyanidin reductase (ANR) and leucoanthocyanidin reductase (LAR) are involved in the last steps of PA biosynthesis. To isolate the genes for these enzymes from buckwheat we performed PCR using degenerate primers and obtained cDNAs of ANR and LAR, which we designated FeANR and FeLAR1. A search for homologs in a buckwheat genome database with both sequences returned two more LAR sequences, designated FeLAR2 and FeLAR3. Linkage analysis with an F2 segregating population indicated that the three LAR loci were not genetically linked. We detected high levels of PAs in roots and cotyledons of buckwheat seedlings and in buds and flowers of mature plants. FeANR and FeLAR1-3 were expressed in most organs but had different expression patterns. Our findings would be useful for breeding and further analysis of PA synthesis and its regulation in buckwheat.

  2. Extremely large electronic anisotropy caused by electronic phase separation in Ca3(Ru0.97Ti0.03)2O7 single crystal

    NASA Astrophysics Data System (ADS)

    Peng, Jing; Wu, Xiaoshan; Mao, Zhiqiang

    2015-03-01

    Bilayered ruthenate Ca3 Ru2O7 exhibits rich electronic and magnetic properties. It orders at 56K, with FM bilayers antiferromagnetically coupled along c-axis (AFM-a). The AFM transition is closely followed by a first-order metal-insulator (MI) transition at 48K where spin directions switch to the b-axis (AFM-b). While this MI transition is accompanied by the opening of anisotropic charge gap; small Fermi pockets survive from the MI transition, thus resulting in quasi-2D metallic transport behavior for T<30K. We previously showed such a quasi-2D metal with the AFM-b order composed of FM bilayers can be tuned to a Mott-insulating state with a nearest-neighbor AFM order via Ti doping. Ca3(Ru0 . 97 Ti0 . 03) 2O7 is close to the critical composition for the AFM-b-to-G-AFM phase transition. Our recent studies show the sample with this composition is characterized by an electronic phase separation between the insulating G-AFM phase (major) and the localized AFM-b phase (minor). The minor AFM-b phase forms a conducting path through electronic percolation within the ab-plane, but not along the c-axis, thus resulting in extremely large electronic anisotropy with ρab /ρc ~109 , which may be the largest among bulk materials.

  3. Reversed-phase liquid chromatography using mandelic acid as an eluent for the determination of uranium in presence of large amounts of thorium.

    PubMed

    Jaison, P G; Telmore, Vijay M; Kumar, Pranaw; Aggarwal, Suresh K

    2009-02-27

    Studies were carried out for the separation of uranium (U) and thorium (Th) on reversed-phase (RP) C18 columns using mandelic acid as an eluent. Retention of thorium-mandelate on the unmodified stationary phase was found to be greater than that of uranyl-mandelate under the pH conditions employed. Th retention capacity of the stationary phase was determined as a function of pH and MeOH content of the mobile phase. The optimised parameters allowing U elution prior to Th were utilized for the determination of small amounts of U in the presence of large amounts of Th. The method has been used for the determination of U in synthetic samples with Th/U amount ratios up to 100,000 (10 microg/g of U) without any pre-separation, employing a particulate C18 column. Effect of concentration of ion interaction reagents (IIRs) on the retention was studied to understand the mechanism of adsorption of their mandelate complexes onto the stationary phase. The experiments conducted unequivocally prove that thorium-mandelate complex is neutral whereas uranyl-mandelate complex is anionic in nature.

  4. Pore pressure behavior at the shut-in phase and causality of large induced seismicity at Basel, Switzerland

    NASA Astrophysics Data System (ADS)

    Mukuhira, Y.; Dinske, C.; Asanuma, H.; Ito, T.; Häring, M. O.

    2017-01-01

    Induced seismicity with unexpectedly large magnitude often occurs after shut-in or end of stimulation, generating concerns at the end of stimulation. We investigated the physical mechanism of large-magnitude induced seismicity during shut-in following the hydraulic stimulation at Basel, Switzerland. Larger postinjection events occurred at the periphery of the seismic cloud. We estimated the pore pressure required to cause shear slip using Coulomb failure criteria from stress information, geometry of the fault planes of microseismic events, and a constant coefficient of friction. Time series analysis of pore pressure distribution indicated that pore pressure migrated to the far field even after shut-in. Redistribution of pore pressure at shut-in brought sufficient pore pressure increase to induce seismicity in the peripheral region. After shut-in, the pore pressure gradient away from the well lessened and eventually pressure became uniform. These observations suggest that the higher pore pressure, which remained in the vicinity of the injection point, shifted to the farthest field. Shut-in pressure migration caused uniform pore pressure distribution at the edge of the seismic zone. Shut-in pressure destabilized a large part of the fault located at the edge of the seismic cloud, resulting in the shear slip of a large section of the fault. Meanwhile, during stimulation, only some parts of the fault entered the critical state because of the pressure gradient. The resulting shear slip on that specific part causes moderate magnitude events at most.

  5. Feasibility of using lateral mode coupling method for a large scale ultrasound phased array for noninvasive transcranial therapy.

    PubMed

    Song, Junho; Hynynen, Kullervo

    2010-01-01

    A hemispherical-focused, ultrasound phased array was designed and fabricated using 1372 cylindrical piezoelectric transducers that utilize lateral coupling for noninvasive transcranial therapy. The cylindrical transducers allowed the electrical impedance to be reduced by at least an order of magnitude, such that effective operation could be achieved without electronic matching circuits. In addition, the transducer elements generated the maximum acoustic average surface intensity of 27 W/cm(2). The array, driven at the low (306-kHz) or high frequency (840-kHz), achieved excellent focusing through an ex vivo human skull and an adequate beam steering range for clinical brain treatments. It could electronically steer the ultrasound beam over cylindrical volumes of 100-mm in diameter and 60-mm in height at 306 kHz, and 30-mm in diameter and 30-mm in height at 840 kHz. A scanning laser vibrometer was used to investigate the radial and length mode vibrations of the element. The maximum pressure amplitudes through the skull at the geometric focus were predicted to be 5.5 MPa at 306 kHz and 3.7 MPa at 840 kHz for RF power of 1 W on each element. This is the first study demonstrating the feasibility of using cylindrical transducer elements and lateral coupling in construction of ultrasound phased arrays.

  6. Locomotor versatility in the white-handed gibbon (Hylobates lar): a spatiotemporal analysis of the bipedal, tripedal, and quadrupedal gaits.

    PubMed

    Vereecke, Evie E; D'Août, Kristiaan; Aerts, Peter

    2006-05-01

    This study gives a qualitative and quantitative description of the different terrestrial locomotor modes of a group of white-handed gibbons (Hylobates lar) from the Wild Animal Park Planckendael, Belgium. The gibbons were filmed during voluntary locomotion on a grassy and smooth substrate and on a pole. These video images allowed us to define seven different gait types, based on spatial and temporal footfall patterns. Consequent digitization of the video images (n = 254) yielded duty factors, stride lengths, and stride frequencies of the fore- and hind limbs during locomotion at a wide range of speeds. These spatiotemporal gait characteristics were regressed against velocity, and the regression lines of the different gait types were compared. In addition, gibbon bipedalism was compared with bonobo (Pan paniscus) and human bipedalism. Gibbons appear to be very versatile animals, using a bipedal, tripedal, or quadrupedal gait during terrestrial travel with an overlapping speed range. The spatiotemporal characteristics of these gaits are largely similar, although they have clearly distinct footfall patterns. Bipedal walking on the pole is slightly different from terrestrial bipedalism, but differences between substrate types (grass vs. catwalk) are subtle. During bipedalism, gibbons increase both stride length and frequency to increase speed, just as humans and bonobos do, but at a given speed, gibbons take relatively larger strides at lower rates. Bipedal walking in gibbons also appears to be relatively fast-gibbons could keep on walking at speeds where humans have to start running. Apparently, adaptations for arboreal locomotion have not constrained the terrestrial locomotor abilities of gibbons. This may indicate that the step from an arboreal ancestral ape to a terrestrial, upright bipedal hominin might not be difficult and that structural specializations are not a prerequisite for adopting a (non-habitual) bipedal gait.

  7. LARGE-SCALE CONTRACTION AND SUBSEQUENT DISRUPTION OF CORONAL LOOPS DURING VARIOUS PHASES OF THE M6.2 FLARE ASSOCIATED WITH THE CONFINED FLUX ROPE ERUPTION

    SciTech Connect

    Kushwaha, Upendra; Joshi, Bhuwan; Moon, Yong-Jae; Veronig, Astrid M.

    2015-07-01

    We investigate evolutionary phases of an M6.2 flare and the associated confined eruption of a prominence. The pre-flare phase exhibits spectacular large-scale contraction of overlying extreme ultraviolet (EUV) coronal loops during which the loop system was subjected to an altitude decrease of ∼20 Mm (40% of the initial height) for an extended span of ∼30 minutes. This contraction phase is accompanied by sequential EUV brightenings associated with hard X-ray (HXR; up to 25 keV) and microwave (MW) sources from low-lying loops in the core region which together with X-ray spectra indicate strong localized heating in the source region before the filament activation. With the onset of the flare’s impulsive phase, we detect HXR and MW sources that exhibit intricate temporal and spatial evolution in relation to the fast rise of the prominence. Following the flare maximum, the filament eruption slowed down and subsequently became confined within the large overlying active region loops. During the confinement process of the erupting prominence, we detect MW emission from the extended coronal region with multiple emission centroids, which likely represent emission from hot blobs of plasma formed after the collapse of the expanding flux rope and entailing prominence material. RHESSI spectroscopy reveals high plasma temperature (∼30 MK) and substantial non-thermal characteristics (δ ∼ 5) during the impulsive phase of the flare. The time evolution of thermal energy exhibits a good correspondence with the variations in cumulative non-thermal energy, which suggests that the energy of accelerated particles is efficiently converted to hot flare plasma, implying an effective validation of the Neupert effect.

  8. E-health, phase two: the imperative to integrate process automation with communication automation for large clinical reference laboratories.

    PubMed

    White, L; Terner, C

    2001-01-01

    The initial efforts of e-health have fallen far short of expectations. They were buoyed by the hype and excitement of the Internet craze but limited by their lack of understanding of important market and environmental factors. E-health now recognizes that legacy systems and processes are important, that there is a technology adoption process that needs to be followed, and that demonstrable value drives adoption. Initial e-health transaction solutions have targeted mostly low-cost problems. These solutions invariably are difficult to integrate into existing systems, typically requiring manual interfacing to supported processes. This limitation in particular makes them unworkable for large volume providers. To meet the needs of these providers, e-health companies must rethink their approaches, appropriately applying technology to seamlessly integrate all steps into existing business functions. E-automation is a transaction technology that automates steps, integration of steps, and information communication demands, resulting in comprehensive automation of entire business functions. We applied e-automation to create a billing management solution for clinical reference laboratories. Large volume, onerous regulations, small margins, and only indirect access to patients challenge large laboratories' billing departments. Couple these problems with outmoded, largely manual systems and it becomes apparent why most laboratory billing departments are in crisis. Our approach has been to focus on the most significant and costly problems in billing: errors, compliance, and system maintenance and management. The core of the design relies on conditional processing, a "universal" communications interface, and ASP technologies. The result is comprehensive automation of all routine processes, driving out errors and costs. Additionally, compliance management and billing system support and management costs are dramatically reduced. The implications of e-automated processes can extend

  9. Large entropy change accompanying two successive magnetic phase transitions in TbMn2Si2 for magnetic refrigeration

    NASA Astrophysics Data System (ADS)

    Li, Guoxing; Wang, Jianli; Cheng, Zhenxiang; Ren, Qingyong; Fang, Chunsheng; Dou, Shixue

    2015-05-01

    Structural and magnetic properties in TbMn2Si2 are studied by variable temperature X-ray diffraction, magnetization, electrical resistivity, and heat capacity measurements. TbMn2Si2 undergoes two successive magnetic transitions at around Tc1 = 50 K and Tc2 = 64 K. Tc1 remains almost constant with increasing magnetic field, but Tc2 shifts significantly to higher temperature. Thus, there are two partially overlapping peaks in the temperature dependence of magnetic entropy change, i.e., -ΔSM (T). The different responses of Tc1 and Tc2 to external magnetic field, and the overlapping of -ΔSM (T) around Tc1 and Tc2 induce a large refrigerant capacity (RC) within a large temperature range. The large reversible magnetocaloric effect (-ΔSMpeak ˜ 16 J/kg K for a field change of 0-5 T) and RC (=396 J/kg) indicate that TbMn2Si2 could be a promising candidate for low temperature magnetic refrigeration.

  10. Analysis of a dual-twist Pancharatnam phase device with ultrahigh-efficiency large-angle optical beam steering.

    PubMed

    Cheng, HsienHui; Bhowmik, Achintya K; Bos, Philip J

    2015-12-01

    It has been previously shown that a Pancharatnam phase device with a dual-twist structure can deflect light up to 60° with nearly perfect efficiency. This was beyond the limits previously assumed for these types of devices, which were considered to be optically similar to Raman-Nath gratings. In this paper we first consider the range of parameters that will allow for high efficiency and show the results for a structure that demonstrates 80° deflection. We then explore the light propagation through these devices to point out interesting intensity variations in the deflected mode of light as it traverses the deflecting layer. Finally, we explain the key to understanding the efficiency of these devices, which is not the typical parameters that are important for traditional diffractive devices, but rather the control of the polarization state of light. We provide a simple design approach for optimizing the twist angle and retardation for high efficiency.

  11. Distinguishing between direct and indirect directional couplings in large oscillator networks: Partial or non-partial phase analyses?

    NASA Astrophysics Data System (ADS)

    Rings, Thorsten; Lehnertz, Klaus

    2016-09-01

    We investigate the relative merit of phase-based methods for inferring directional couplings in complex networks of weakly interacting dynamical systems from multivariate time-series data. We compare the evolution map approach and its partialized extension to each other with respect to their ability to correctly infer the network topology in the presence of indirect directional couplings for various simulated experimental situations using coupled model systems. In addition, we investigate whether the partialized approach allows for additional or complementary indications of directional interactions in evolving epileptic brain networks using intracranial electroencephalographic recordings from an epilepsy patient. For such networks, both direct and indirect directional couplings can be expected, given the brain's connection structure and effects that may arise from limitations inherent to the recording technique. Our findings indicate that particularly in larger networks (number of nodes ≫10 ), the partialized approach does not provide information about directional couplings extending the information gained with the evolution map approach.

  12. Distinguishing between direct and indirect directional couplings in large oscillator networks: Partial or non-partial phase analyses?

    PubMed

    Rings, Thorsten; Lehnertz, Klaus

    2016-09-01

    We investigate the relative merit of phase-based methods for inferring directional couplings in complex networks of weakly interacting dynamical systems from multivariate time-series data. We compare the evolution map approach and its partialized extension to each other with respect to their ability to correctly infer the network topology in the presence of indirect directional couplings for various simulated experimental situations using coupled model systems. In addition, we investigate whether the partialized approach allows for additional or complementary indications of directional interactions in evolving epileptic brain networks using intracranial electroencephalographic recordings from an epilepsy patient. For such networks, both direct and indirect directional couplings can be expected, given the brain's connection structure and effects that may arise from limitations inherent to the recording technique. Our findings indicate that particularly in larger networks (number of nodes ≫10), the partialized approach does not provide information about directional couplings extending the information gained with the evolution map approach.

  13. Composition design for Laves phase-related body-centered cubic-V solid solution alloys with large hydrogen storage capacities.

    PubMed

    Wang, H B; Wang, Q; Dong, C; Yuan, L; Xu, F; Sun, L X

    2008-03-19

    This paper analyzes the characteristics of alloy compositions with large hydrogen storage capacities in Laves phase-related body-centered cubic (bcc) solid solution alloy systems using the cluster line approach. Since a dense-packed icosahedral cluster A(6)B(7) characterizes the local structure of AB(2) Laves phases, in an A-B-C ternary system, such as Ti-Cr (Mn, Fe)-V, where A-B forms AB(2) Laves phases while A-C and B-C tend to form solid solutions, a cluster line A(6)B(7)-C is constructed by linking A(6)B(7) to C. The alloy compositions with large hydrogen storage capacities are generally located near this line and are approximately expressed with the cluster-plus-glue-atom model. The cluster line alloys (Ti(6)Cr(7))(100-x)V(x) (x = 2.5-70 at.%) exhibit different structures and hence different hydrogen storage capacities with increasing V content. The alloys (Ti(6)Cr(7))(95)V(5) and Ti(30)Cr(40)V(30) with bcc solid solution structure satisfy the cluster-plus-glue-atom model.

  14. Large-Scale Hybrid Density Functional Theory Calculations in the Condensed-Phase: Ab Initio Molecular Dynamics in the Isobaric-Isothermal Ensemble

    NASA Astrophysics Data System (ADS)

    Ko, Hsin-Yu; Santra, Biswajit; Distasio, Robert A., Jr.; Wu, Xifan; Car, Roberto

    Hybrid functionals are known to alleviate the self-interaction error in density functional theory (DFT) and provide a more accurate description of the electronic structure of molecules and materials. However, hybrid DFT in the condensed-phase has a prohibitively high associated computational cost which limits their applicability to large systems of interest. In this work, we present a general-purpose order(N) implementation of hybrid DFT in the condensed-phase using Maximally localized Wannier function; this implementation is optimized for massively parallel computing architectures. This algorithm is used to perform large-scale ab initio molecular dynamics simulations of liquid water, ice, and aqueous ionic solutions. We have performed simulations in the isothermal-isobaric ensemble to quantify the effects of exact exchange on the equilibrium density properties of water at different thermodynamic conditions. We find that the anomalous density difference between ice I h and liquid water at ambient conditions as well as the enthalpy differences between ice I h, II, and III phases at the experimental triple point (238 K and 20 Kbar) are significantly improved using hybrid DFT over previous estimates using the lower rungs of DFT This work has been supported by the Department of Energy under Grants No. DE-FG02-05ER46201 and DE-SC0008626.

  15. Developing LAr Scintillation Light Collection Ideas in the Short Baseline Neutrino Detector

    SciTech Connect

    Szelc, A. M.

    2016-02-08

    Scintillation light is becoming the most rapidly developing feature of Liquid Argon Time Projection Chamber (LArTPC) neutrino detectors due to its capability to enhance and expand their physics reach traditionally based on charge readout. The SBND detector, set to be built on the Booster Neutrino Beam Line at Fermilab, is in a unique position to test novel liquid argon scintillation light readout systems in a detector with physics neutrino events. The different ideas under consideration by the collaboration are described, including an array of PMTs detecting direct light, SiPM coupled lightguide bars and a setup which uses PMTs/SiPMS and wavelength shifter covered reflector foils, as well as their respective strengths and physics foci and the benchmarks used to compare them.

  16. Detailed Hylobates lar karyotype defined by 25-color FISH and multicolor banding.

    PubMed

    Mrasek, Kristin; Heller, Anita; Rubtsov, Nikolai; Trifonov, Vladimir; Starke, Heike; Claussen, Uwe; Liehr, Thomas

    2003-08-01

    A comprehensive and detailed comparative chromosome map of the white-handed gibbon (Hylobates lar = HLA) has been established by hybridizing the recently developed complete human multicolor banding (MCB) probe set on metaphase chromosomes of a male HLA lymphoblastoid cell line. Thus, it was possible to precisely determine the breakpoints and distribution plus orientation of specific DNA-regions in this cytogenetically highly rearranged species compared to Homo sapiens (HSA). In general, the obtained results are in concordance with previous molecular-cytogenetic studies. In this study all 71 breakpoints present in HLA compared to HSA could be determined exactly. This study is a valuable complement to our knowledge on the phylogeny of huminoid chromosomes.

  17. Diffuse interface modeling of three-phase contact line dynamics on curved boundaries: A lattice Boltzmann model for large density and viscosity ratios

    NASA Astrophysics Data System (ADS)

    Fakhari, Abbas; Bolster, Diogo

    2017-04-01

    We introduce a simple and efficient lattice Boltzmann method for immiscible multiphase flows, capable of handling large density and viscosity contrasts. The model is based on a diffuse-interface phase-field approach. Within this context we propose a new algorithm for specifying the three-phase contact angle on curved boundaries within the framework of structured Cartesian grids. The proposed method has superior computational accuracy compared with the common approach of approximating curved boundaries with stair cases. We test the model by applying it to four benchmark problems: (i) wetting and dewetting of a droplet on a flat surface and (ii) on a cylindrical surface, (iii) multiphase flow past a circular cylinder at an intermediate Reynolds number, and (iv) a droplet falling on hydrophilic and superhydrophobic circular cylinders under differing conditions. Where available, our results show good agreement with analytical solutions and/or existing experimental data, highlighting strengths of this new approach.

  18. Development of a single-phase harmonic power flow program to study the 20 kHz AC power system for large spacecraft

    NASA Technical Reports Server (NTRS)

    Kraft, L. Alan; Kankam, M. David

    1991-01-01

    The development of software is described to aid in design and analysis of AC power systems for large spacecraft. The algorithm is an important version of harmonic power flow program, HARMFLO, used for the study of AC power quality. The new program is applicable to three-phase systems typified by terrestrial power systems, and single-phase systems characteristic of space power systems. The modified HARMFLO accommodates system operating frequencies ranging from terrestrial 60 Hz to and beyond aerospace 20 kHz, and can handle both source and load-end harmonic distortions. Comparison of simulation and test results of a representative spacecraft power system shows a satisfactory correlation. Recommendations are made for the direction of future improvements to the software, to enhance its usefulness to power system designer and analysts.

  19. Phased Array Ultrasonic Sound Field Mapping through Large-Bore Coarse Grained Cast Austenitic Stainless Steel (CASS) Components

    SciTech Connect

    Crawford, Susan L.; Cinson, Anthony D.; Prowant, Matthew S.; Coble, Jamie B.; Diaz, Aaron A.; Anderson, Michael T.

    2012-09-01

    A sound field beam mapping exercise was conducted to assist in understanding the effects of coarse-grained microstructures found in cast austenitic stainless steel (CASS) materials on acoustic longitudinal wave propagation. Ultrasonic laboratory measurements were made on three specimens representing four different grain structures. Phased array (PA) probes were fixed on each specimen surface and excited in the longitudinal mode at specific angles while a point receiver was scanned in a raster pattern over the end of the specimen, generating a transmitted sound field image. Three probes operating at nominal frequencies of 0.5, 0.8, and 1.0 MHz were used. A 6.4 mm (0.25-in.) thick slice was removed from the specimen end and beam mapping was repeated three times, yielding four full sets of beam images. Data were collected both with a constant part path for each configuration (probe, specimen and slice, angle, etc.) and with a variable part path (fixed position on the surface). The base specimens and slices were then polished and etched to reveal measureable grain microstructures that were compared to the sound field interactions and scattering effects seen in the collected data.

  20. The Fanconi Anemia BRCA Pathway as a Predictor of Benefit from Bevacizumab in a Large Phase 3 Clinical Trial in Ovarian Cancer

    DTIC Science & Technology

    2014-12-01

    1 AWARD NUMBER: W81XWH-13-1-0421 TITLE: The Fanconi Anemia BRCA Pathway as a Predictor of Benefit from Bevacizumab in a Large Phase III Clinical...DATES COVERED 30Sep2013 - 29Sep2015 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER W81XWH-13-1-0421 The Fanconi Anemia BRCA Pathway as a Predictor of...another upfront clinical trial GOG262. We found that germline or somatic mutations in the BRCA-Fanconi anemia pathway was significantly associated with

  1. Effect of electron plasma waves with relativistic phase velocity on large-angle stimulated Raman scattering of modulated short laser pulse in plasmas

    NASA Astrophysics Data System (ADS)

    Andreev, Nikolai E.; Kalmykov, S. Y.

    2001-03-01

    Suppression of a large-angle stimulated Raman scattering (LA-SRS) of a short modulated (two-frequency) laser pulse in a transparent plasma in the presence of a linear long- wavelength electron plasma wave (LW EPW) having relativistic phase velocity is considered under the conditions of weak and strong coupling. The laser spectrum includes two components with a frequency shift equal to the frequency of the LW EPW. The mutual influence of different spectral components of a laser on the SRS under a given angle in the presence of the LW EPW is examined.

  2. Effective method to compute vibrationally resolved optical spectra of large molecules at finite temperature in the gas phase and in solution.

    PubMed

    Santoro, Fabrizio; Lami, Alessandro; Improta, Roberto; Barone, Vincenzo

    2007-05-14

    The authors present a new method for the computation of vibrationally resolved optical spectra of large molecules, including the Duschinsky rotation of the normal modes and the effect of thermal excitation. The method automatically selects the relevant vibronic contributions to the spectrum, independently of their frequency, and it is able to provide fully converged spectra with moderate computational times, both in vacuo and in solution. By describing the electronic states in the frame of the density functional theory and its time-dependent extension, they computed the room temperature absorption spectra of coumarin C153 and trans-stilbene in cyclohexane and the phosphorescence spectrum of porphyrazine in gas phase, showing that the method is fast and efficient. The comparison with experiment for trans-stilbene and coumarin C153 is very satisfactory, confirming the progress made toward a reliable method for the computation and interpretation for the optical spectra of large molecules.

  3. Study to investigate design, fabrication and test of low cost concepts for large hybrid composite helicopter fuselage, phase 1

    NASA Technical Reports Server (NTRS)

    Adams, K. M.; Lucas, J. J.

    1975-01-01

    The development of a frame/stringer/skin fabrication technique for composite airframe construction was studied as a low cost approach to the manufacture of large helicopter airframe components. A center cabin aluminum airframe section of the Sikorsky CH-53D helicopter was selected for evaluation as a composite structure. The design, as developed, is composed of a woven KEVLAR-49/epoxy skin and graphite/epoxy frames and stringers. To support the selection of this specific design concept a materials study was conducted to develop and select a cure compatible graphite and KEVLAR-49/epoxy resin system, and a foam system capable of maintaining shape and integrity under the processing conditions established. The materials selected were, Narmco 5209/Thornel T-300 graphite, Narmco 5209/KEVLAR-49 woven fabric, and Stathane 8747 polyurethane foam. Eight specimens were fabricated, representative of the frame, stringer, and splice joint attachments. Evaluation of the results of analysis and test indicate that design predictions are good to excellent except for some conservatism of the complex frame splice.

  4. Lattice Boltzmann modeling of contact angle and its hysteresis in two-phase flow with large viscosity difference

    NASA Astrophysics Data System (ADS)

    Liu, Haihu; Ju, Yaping; Wang, Ningning; Xi, Guang; Zhang, Yonghao

    2015-09-01

    Contact angle hysteresis is an important physical phenomenon omnipresent in nature and various industrial processes, but its effects are not considered in many existing multiphase flow simulations due to modeling complexity. In this work, a multiphase lattice Boltzmann method (LBM) is developed to simulate the contact-line dynamics with consideration of the contact angle hysteresis for a broad range of kinematic viscosity ratios. In this method, the immiscible two-phase flow is described by a color-fluid model, in which the multiple-relaxation-time collision operator is adopted to increase numerical stability and suppress unphysical spurious currents at the contact line. The contact angle hysteresis is introduced using the strategy proposed by Ding and Spelt [Ding and Spelt, J. Fluid Mech. 599, 341 (2008), 10.1017/S0022112008000190], and the geometrical wetting boundary condition is enforced to obtain the desired contact angle. This method is first validated by simulations of static contact angle and dynamic capillary intrusion process on ideal (smooth) surfaces. It is then used to simulate the dynamic behavior of a droplet on a nonideal (inhomogeneous) surface subject to a simple shear flow. When the droplet remains pinned on the surface due to hysteresis, the steady interface shapes of the droplet quantitatively agree well with the previous numerical results. Four typical motion modes of contact points, as observed in a recent study, are qualitatively reproduced with varying advancing and receding contact angles. The viscosity ratio is found to have a notable impact on the droplet deformation, breakup, and hysteresis behavior. Finally, this method is extended to simulate the droplet breakup in a microfluidic T junction, with one half of the wall surface ideal and the other half nonideal. Due to the contact angle hysteresis, the droplet asymmetrically breaks up into two daughter droplets with the smaller one in the nonideal branch channel, and the behavior of

  5. Lattice Boltzmann modeling of contact angle and its hysteresis in two-phase flow with large viscosity difference.

    PubMed

    Liu, Haihu; Ju, Yaping; Wang, Ningning; Xi, Guang; Zhang, Yonghao

    2015-09-01

    Contact angle hysteresis is an important physical phenomenon omnipresent in nature and various industrial processes, but its effects are not considered in many existing multiphase flow simulations due to modeling complexity. In this work, a multiphase lattice Boltzmann method (LBM) is developed to simulate the contact-line dynamics with consideration of the contact angle hysteresis for a broad range of kinematic viscosity ratios. In this method, the immiscible two-phase flow is described by a color-fluid model, in which the multiple-relaxation-time collision operator is adopted to increase numerical stability and suppress unphysical spurious currents at the contact line. The contact angle hysteresis is introduced using the strategy proposed by Ding and Spelt [Ding and Spelt, J. Fluid Mech. 599, 341 (2008)JFLSA70022-112010.1017/S0022112008000190], and the geometrical wetting boundary condition is enforced to obtain the desired contact angle. This method is first validated by simulations of static contact angle and dynamic capillary intrusion process on ideal (smooth) surfaces. It is then used to simulate the dynamic behavior of a droplet on a nonideal (inhomogeneous) surface subject to a simple shear flow. When the droplet remains pinned on the surface due to hysteresis, the steady interface shapes of the droplet quantitatively agree well with the previous numerical results. Four typical motion modes of contact points, as observed in a recent study, are qualitatively reproduced with varying advancing and receding contact angles. The viscosity ratio is found to have a notable impact on the droplet deformation, breakup, and hysteresis behavior. Finally, this method is extended to simulate the droplet breakup in a microfluidic T junction, with one half of the wall surface ideal and the other half nonideal. Due to the contact angle hysteresis, the droplet asymmetrically breaks up into two daughter droplets with the smaller one in the nonideal branch channel, and the

  6. Thalidomide enhanced the efficacy of CHOP chemotherapy in the treatment of diffuse large B cell lymphoma: A phase II study

    PubMed Central

    Ji, Dongmei; Li, Qiu; Cao, Junning; Guo, Ye; Lv, Fangfang; Liu, Xiaojian; Wang, Biyun; Wang, Leiping; Luo, Zhiguo; Chang, Jianhua; Wu, Xianghua; Hong, Xiaonan

    2016-01-01

    Cyclophosphamide, doxorubicin, vincristine, and prednisolone plus rituximab (R-CHOP) is the standard treatment for patients with diffuse large B cell lymphoma (DLBCL). However, rituximab cannot be popularly applied in a considerable number of patients with DLBCL because of economic reasons. To develop a new regimen to improve the outcome of these patients is extremely important. In our study, sixty five patients with DLBCL were randomly assigned to thalidomide plus CHOP group (n=32) or to CHOP alone group (n=33). Objective response rates (ORR) and complete remission rates (CRR) were 96.7% and 80.6% in T-CHOP group versus 78.9 % and 57.8 % in CHOP group, respectively (P <0.05). At a median follow-up of 96 months, median PFS for T-CHOP group was still not reached yet, and in CHOP group it was 22.9 months (95% CI [0-50.4]). (P=0.163). Median overall survival (OS) for T-CHOP group was also not reached, and the estimated median OS for CHOP group was 83.5 months, the difference of OS between the two groups is not significant (p=0.263). But, in patients with Bcl-2 positive and Bcl-6 negative, the median PFS in T-CHOP group was longer than that in CHOP group (111.0 vs 8.5 months (P=0.017). In addition, thalidomide did not significantly increase the grade 3/4 toxicity of CHOP. We concluded that the addition of thalidomide to the CHOP regimen significantly improved the CRR and showed a trend of improving clinical outcome in patients with DLBCL, especially for patients with Bcl-2 positive and Bcl-6 negative B-cell phenotype, without increased toxicity. PMID:27129176

  7. Large-scale immunomagnetic selection of CD14+ monocytes to generate dendritic cells for cancer immunotherapy: a phase I study.

    PubMed

    Babatz, J; Röllig, C; Oelschlägel, U; Zhao, S; Ehninger, G; Schmitz, M; Bornhäuser, M

    2003-10-01

    Dendritic cells (DC) are professional antigen-presenting cells that are widely used in the experimental immunotherapy of cancer. For clinical use GMP-like protocols for the preparation of functionally active dendritic cells (DC) in large numbers and at high purity are needed. However, the currently available protocols have certain disadvantages. In this study we tested the generation and clinical applicability of DC from monocyte preparations produced by immunomagnetic CD14(+) selection using a semiautomated clinical scale immunomagnetic column. Peripheral blood mononuclear cells (PBMC) of 10 patients with metastatic solid tumors were used. With the immunomagnetic separation, we obtained a cell suspension of high CD14(+) purity (median 97.4%, range 94.9-99.0) with a high monocyte yield (median 82.3%, range 63.9-100.0). Differentiation of CD14(+) cells into mature monocyte-derived DC was induced by incubation with IL-4, GM-CSF, TNF-alpha, PGE(2), IL-1 beta, and IL-6. Mature DC showed a high expression of CD83, HLA-DR, and the co-stimulatory molecules CD80 and CD86. Overall CD83(+) yield was 12.1% (range 4.0-29.4). Allogeneic T stimulatory capacity could be demonstrated for all DC preparations in proliferation assays. No significant differences in marker expression or T cell stimulation was detected between fresh DC and those derived from cryopreserved immature DC. Clinical administration of autologous DC by three different parenteral routes was tolerated by all 10 patients without systemic signs of toxicity. Our results indicate that immunomagnetic isolation of CD14(+) monocytes using the CliniMACS device is a suitable method for clinical-scale generation of functional DC under GMP-grade conditions. The selection can be performed in a closed system. Therefore, immunomagnetic CD14(+) selection can be seen as an alternative way to generate DC for clinical tumor vaccination protocols.

  8. MRF Applications: On the Road to Making Large-Aperture Ultraviolet Laser Resistant Continuous Phase Plates for High-Power Lasers

    SciTech Connect

    Menapace, J A; Davis, P J; Steele, W A; Hachkowski, M R; Nelson, A; Xin, K

    2006-10-26

    Over the past two years we have developed MRF tools and procedures to manufacture large-aperture (430 X 430 mm) continuous phase plates (CPPs) that are capable of operating in the infrared portion (1053 nm) of high-power laser systems. This is accomplished by polishing prescribed patterns of continuously varying topographical features onto finished plano optics using MRF imprinting techniques. We have been successful in making, testing, and using large-aperture CPPs whose topography possesses spatial periods as low as 4 mm and surface peak-to-valleys as high as 8.6 {micro}m. Combining this application of MRF technology with advanced MRF finishing techniques that focus on ultraviolet laser damage resistance makes it potentially feasible to manufacture large-aperture CPPs that can operate in the ultraviolet (351 nm) without sustaining laser-induced damage. In this paper, we will discuss the CPP manufacturing process and the results of 351-nm/3-nsec equivalent laser performance experiments conducted on large-aperture CPPs manufactured using advanced MRF protocols.

  9. Injectable controlled release depots for large molecules

    PubMed Central

    Schwendeman, Steven P.; Shah, Ronak B.; Bailey, Brittany A.; Schwendeman, Anna S.

    2014-01-01

    Biodegradable, injectable depot formulations for long-term controlled drug release have improved therapy for a number of drug molecules and led to over a dozen highly successful pharmaceutical products. Until now, success has been limited to several small molecules and peptides, although remarkable improvements have been accomplished in some of these cases. For example, twice-a-year depot injections with leuprolide are available compared to the once-a-day injection of the solution dosage form. Injectable depots are typically prepared by encapsulation of the drug in poly(lactic-co-glycolic acid) (PLGA), a polymer that is used in children every day as a resorbable suture material, and therefore, highly biocompatible. PLGAs remain today as one of the few “real world” biodegradable synthetic biomaterials used in US FDA-approved parenteral long-acting-release (LAR) products. Despite their success, there remain critical barriers to the more widespread use of PLGA LAR products, particularly for delivery of more peptides and other large molecular drugs, namely proteins. In this review, we describe key concepts in the development of injectable PLGA controlled-release depots for peptides and proteins, and then use this information to identify key issues impeding greater widespread use of PLGA depots for this class of drugs. Finally, we examine important approaches, particularly those developed in our research laboratory, toward overcoming these barriers to advance commercial LAR development. PMID:24929039

  10. Large Eddy Simulation of Bubbly Flow and Slag Layer Behavior in Ladle with Discrete Phase Model (DPM)-Volume of Fluid (VOF) Coupled Model

    NASA Astrophysics Data System (ADS)

    Li, Linmin; Liu, Zhongqiu; Cao, Maoxue; Li, Baokuan

    2015-07-01

    In the ladle metallurgy process, the bubble movement and slag layer behavior is very important to the refining process and steel quality. For the bubble-liquid flow, bubble movement plays a significant role in the phase structure and causes the unsteady complex turbulent flow pattern. This is one of the most crucial shortcomings of the current two-fluid models. In the current work, a one-third scale water model is established to investigate the bubble movement and the slag open-eye formation. A new mathematical model using the large eddy simulation (LES) is developed for the bubble-liquid-slag-air four-phase flow in the ladle. The Eulerian volume of fluid (VOF) model is used for tracking the liquid-slag-air free surfaces and the Lagrangian discrete phase model (DPM) is used for describing the bubble movement. The turbulent liquid flow is induced by bubble-liquid interactions and is solved by LES. The procedure of bubble coming out of the liquid and getting into the air is modeled using a user-defined function. The results show that the present LES-DPM-VOF coupled model is good at predicting the unsteady bubble movement, slag eye formation, interface fluctuation, and slag entrainment.

  11. Development of high internal phase emulsion polymeric monoliths for highly efficient enrichment of trace polycyclic aromatic hydrocarbons from large-volume water samples.

    PubMed

    Su, Rihui; Ruan, Guihua; Nie, Honggang; Xie, Ting; Zheng, Yanjie; Du, Fuyou; Li, Jianping

    2015-07-31

    In this work, polymerized high internal phase emulsion (polyHIPE) monoliths were prepared and applied as monolithic adsorbent materials for proconcentration of trace polycyclic aromatic hydrocarbons (PAHs) from large-volume water samples. The monolithic polyHIPE columns were prepared by in situ polymerization of the continuous phase of a high internal phase emulsion (HIPE) containing styrene (STY), divinylbenzene (DVB) and glycidyl methacrylate (GMA) in pipette tips, and the resulting STY/DVB/GMA polyHIPE monoliths exhibited highly interconnected porosity and large surface areas, making them excellent candidates as adsorbents for enrichment of trace aromatic compounds. The prepared STY/DVB/GMA polyHIPE monoliths were applied to the determination of trace PAHs in environmental water samples by combing with high performance liquid chromatography-fluorescence detection (HPLC-FLD). Under the optimized experimental conditions, the polyHIPE monoliths could effectively enrich trace 13 PAHs from 500mL of water samples, the mean recoveries at four spiked levels were ranged from 80.7% to 115.0% with the relative standard deviations (RSDs) lower than 14%, and the detection limits (LODs) were ranged from 4.0 to 228pg/L. In addition, the prepared polyHIPE monolith was stable enough for more than 200 replicate extraction cycles without measurable loss of performance on the enrichment of PAHs, and good column-to-column repeatability was obtained with RSD less than 13%. The proposed method was applied to simultaneous analysis of 13 PAHs in water samples with satisfactory recoveries.

  12. A very slow basal layer underlying large-scale low-velocity anomalies in the lower mantle beneath the Pacific: evidence from core phases

    NASA Astrophysics Data System (ADS)

    Garnero, Edward J.; Helmberger, Donald V.

    A multi-phase analysis using long-period World Wide Standardized Seismograph Network and Canadian Network data has been conducted using core-phases for deep focus events from the southwest Pacific. These include SKS, S2KS, SV diff, and SP dKS. The last phase emerges from SKS near 106° and is associated with a P-wave diffracting along the bottom of the mantle. Patterns in S2KS - SKS differential travel times ( TS2KS - SKS) correlate with those in SP dKS - SKS ( TSP dKS - SKS ). TS2KS - SKS values strongly depend on variations in VS structure in the lower third of the mantle, whereas TSP dKS - SKS values mainly depend on VP structure and variations in a thin zone (100 km or less) at the very base of the mantle. Anomalously large TS2KS - SKS and TSP dKS - SKS values (relative to the Preliminary Reference Earth Model (PREM)) are present for Fiji-Tonga and Kermadec events (recorded in North and South America), along with anomalously large SV diff amplitudes well into the core's shadow. More northerly paths beneath the Pacific to North America for Indonesian and Solomon events display both PREM-like and anomalous times. A model compatible with the observations is presented, and contains a thin very-low-velocity layer at the base of the mantle that underlies the large volumetric lower-mantle low-velocity regions in the southwest Pacific. A low-velocity layer of 20-100 km thickness with reductions of up to 5-10% (relative to PREM) can reproduce TSP dKS - SKS as well as SV diff amplitudes. Large-scale (more than 1000 km) lower-mantle VS heterogeneity (2-4%) can explain long-wavelength trends in TS2KS - SKS. The exact thickness and velocity reduction in the basal layer is uncertain, owing to difficulties in resolving whether anomalous structure occurs on the source- and/or receiver-side of wavepaths (at the CMB).

  13. Determination of dissolved-phase pesticides in surface water from the Yakima River basin, Washington, using the Goulden large-sample extractor and gas chromatography/mass spectrometry

    USGS Publications Warehouse

    Foster, G.D.; Gates, Paul M.; Foreman, W.T.; McKenzie, S.W.; Rinella, F.A.

    1993-01-01

    Concentrations of pesticides in the dissolved phase of surface water samples from the Yakima River basin, WA, were determined using preconcentration in the Goulden large-sample extractor (GLSE) and gas chromatography/ mass spectrometry (GC/MS) analysis. Sample volumes ranging from 10 to 120 L were processed with the GLSE, and the results from the large-sample analyses were compared to those derived from 1-L continuous liquid-liquid extractions. Few of the 40 target pesticides were detected in 1-L samples, whereas large-sample preconcentration in the GLSE provided detectable levels for many of the target pesticides. The number of pesticides detected in GLSE processed samples was usually directly proportional to sample volume, although the measured concentrations of the pesticides were generally lower at the larger sample volumes for the same water source. The GLSE can be used to provide lower detection levels relative to conventional liquid-liquid extraction in GC/MS analysis of pesticides in samples of surface water. ?? 1993 American Chemical Society.

  14. Determination of dissolved-phase pesticides in surface water from the Yakima River basin, Washington, using the Goulden large-sample extractor and gas chromatography/mass spectrometer

    USGS Publications Warehouse

    Foster, Gregory D.; Gates, Paul M.; Foreman, William T.; McKenzie, Stuart W.; Rinella, Frank A.

    1993-01-01

    Concentrations of pesticides in the dissolved phase of surface water samples from the Yakima River basin, WA, were determined using preconcentration in the Goulden large-sample extractor (GLSE) and gas chromatography/mass spectrometry (GC/MS) analysis. Sample volumes ranging from 10 to 120 L were processed with the GLSE, and the results from the large-sample analyses were compared to those derived from 1-L continuous liquid-liquid extractions Few of the 40 target pesticides were detected in 1-L samples, whereas large-sample preconcentration in the GLSE provided detectable levels for many of the target pesticides. The number of pesticides detected in GLSE processed samples was usually directly proportional to sample volume, although the measured concentrations of the pesticides were generally lower at the larger sample volumes for the same water source. The GLSE can be used to provide lower detection levels relative to conventional liquid-liquid extraction in GC/MS analysis of pesticides in samples of surface water.

  15. A More Reduced Mantle Source for Enriched Shergottites; Insights from the Olivine-Phyric Shergottite Lar 06319

    NASA Technical Reports Server (NTRS)

    Peslier, A. H.; Hnatyshin, D.; Herd, C. D. K.; Walton, E. L.; Brandon, A. D.; Lapen, T. J.; Shafer, J.

    2010-01-01

    A detailed petrographic study of melt inclusions and Cr-Fe-Ti oxides of LAR 06319 leads to two main conclusions: 1) this enriched oxidized olivine- phyric shergottite represents nearly continuous crystallization of a basaltic shergottite melt, 2) the melt became more oxidized during differentiation. The first crystallized mineral assemblages record the oxygen fugacity which is closest to that of the melt s mantle source, and which is lower than generally attributed to the enriched shergottite group.

  16. A test of the Suits vegetative-canopy reflectance model with LARS soybean-canopy reflectance data

    NASA Technical Reports Server (NTRS)

    Chance, J. E.; Lemaster, E. W.

    1985-01-01

    The Suits vegetative-canopy reflectance model is tested with an extensive set of field reflectance measurements made by the Laboratory for Application of Remote Sensing (LARS) for soybean canopies. The model is tested for the full hemisphere of observer directions as well as the nadir direction. The results show moderate agreement for the visible channels of the Landsat MSS and poor agreement in the near-infrared channel of Landsat MSS. An analysis of errors is given.

  17. Tectonic stress inversion of large multi-phase fracture data sets: application of Win-Tensor to reveal the brittle tectonic history of the Lufilan Arc, DRC

    NASA Astrophysics Data System (ADS)

    Delvaux, Damien; Kipata, Louis; Sintubin, Manuel

    2013-04-01

    Large fault-slip data sets from multiphase orogenic regions present a particular challenge in paleostress reconstructions. The Lufilian Arc is an arcuate fold-and-thrust belt that formed during the late Pan-African times as the result of combined N-S and E-W amalgamation of Gondwana in SE-DRCongo and N-Zambia. We studied more than 22 sites in the Lufilian Arc, and its foreland and correlated the results obtained with existing result in the Ubende belt of W-Tanzania. Most studied sites are characterized by multiphase brittle deformation in which the observed brittle structures are the result of progressive saturation of the host rock by neoformed fractures and the reactivation of early formed fractures. They correspond to large mining exploitations with multiple large and continuous outcrops that allow obtaining datasets sufficiently large to be of statistical significance and often corresponding to several successive brittle events. In this context, the reconstruction of tectonic stress necessitates an initial field-base separation of data, completed by a dynamic separation of the original data set into subsets. In the largest sites, several parts of the deposits have been measured independently and are considered as sub-sites that are be processed separately in an initial stage. The procedure used for interactive fault-slip data separation and stress inversion will be illustrated by field examples (Luiswishi and Manono mining sites). This principle has been applied to all result in the reconstruction of the brittle tectonic history of the region, starting with two major phases of orogenic compression, followed by late orogenic extension and extensional collapse. A regional tectonic inversion during the early Mesozoic, as a result of far- field stresses mark the transition towards rift-related extension. More details in Kipata, Delvaux et al.(2013), Geologica Belgica 16/1-2: 001-017 Win-Tensor can be downloaded at: http://users.skynet.be/damien.delvaux/Tensor/tensor-index.html

  18. A phase II study of sorafenib (BAY 43–9006) in recurrent diffuse large B cell lymphoma: an eastern cooperative oncology group study (E1404)

    PubMed Central

    2013-01-01

    Patients with diffuse large B cell lymphoma (DLBCL) who are not candidates for or recur after autologous stem cell transplant have a poor overall prognosis. We conducted a phase II study of sorafenib (formerly BAY 43–9006) in the treatment of relapsed DLBCL. Fourteen patients were enrolled and assessed for response. Median number of cycles administered was 3 (range, 1–12). Common grade 3 toxicities included fatigue (29%), rash/desquamation (21%) and diarrhea (14%). One complete response (CR) was observed (the 14th patient enrolled). Response rate was 7% (90% CI, 0.4 – 30%). Duration of response was 6 months. Median progression-free survival (PFS) was 2 months (90% CI, 1 – 5 months). Median overall survival (OS) was 9 months (90% CI, 5 – 16 months). Although sorafenib has demonstrated activity in solid malignancies it demonstrated low single agent activity in treatment of DLBCL. PMID:23829878

  19. Evaluation of the effects of ice massage applied to large intestine 4 (hegu) on postpartum pain during the active phase of labor

    PubMed Central

    Can, Hafize Ozturk; Saruhan, Aynur

    2015-01-01

    Background: The uterus continues to contract after childbirth. The pain caused by the contractions of the uterus can be as severe as labor pain. The study was aimed to evaluate the effects of ice massage applied to the large intestine 4 (LI4) on postpartum pain during the active phase of labor. Materials and Methods: The study was designed as a randomized controlled trial with three groups and carried out in two stages. The study sample comprised of 150 pregnant women, who were referred to a maternity hospital. In the experimental group, ice massage was applied to LI4 during four contractions within the active phase of labor. In the placebo group, pressure was applied to LI4 using silicone balloons and the third group was the control group. The Visual Analog Scale (VAS) and The McGill (Melzack) Pain Questionnaire (MPQ) were compared among the experimental, placebo, and control groups. Results: The mothers in the ice application group had the lowest mean VAS score. It was determined that ice massage applied to LI4 during the active phase of labor did not lead to any statistical differences in mothers in the first 24 hours postpartum in terms of the characteristics of the pain with MPQ and VAS. Conclusions: In the study, the perception of pain was tried to be minimized by applying pressure with ice balloons to LI4. However, although the application was determined to have made no difference in the pain intensity, the mothers’ statements in the ice application group suggested that they felt more comfortable than did the mothers in the other groups. PMID:25709702

  20. Twofold enhancement of the hidden-order/large-moment antiferromagnetic phase boundary in the URu2-xFexSi₂ system

    DOE PAGES

    Kanchanavatee, N.; Janoschek, M.; Baumbach, R. E.; ...

    2011-12-16

    Electrical resistivity, specific heat, and magnetization measurements on URu2-xFexSi₂ reveal a twofold enhancement of the “hidden-order” (HO)/large-moment antiferromagnetic (LMAFM) phase boundary T₀(x). The T₀(Pch) curve, obtained by converting x to “chemical pressure” Pch, is strikingly similar to the T₀(P) curve, where P is applied pressure, for URu₂Si₂ both exhibit a “kink” at 1.5 GPa and a maximum at ~7 GPa. This similarity suggests that the HO-LMAFM transition at 1.5 GPa in URu₂Si₂ occurs at x ≈ 0.2 (Pch≈1.5 GPa) in URu2-xFexSi₂. URu2-xFexSi₂ provides an opportunity for studying the HO and LMAFM phases with methods that probe the electronic structure [e.g.,more » scanning tunneling microscopy (STM), angle-resolved photoemission spectroscopy (ARPES), and point-contact spectroscopy (PCS)] but cannot be used under pressure.« less

  1. Twofold enhancement of the hidden-order/large-moment antiferromagnetic phase boundary in the URu2-xFexSi₂ system

    SciTech Connect

    Kanchanavatee, N.; Janoschek, M.; Baumbach, R. E.; Hamlin, J. J.; Zocco, D. A.; Huang, K.; Maple, M. B.

    2011-12-16

    Electrical resistivity, specific heat, and magnetization measurements on URu2-xFexSi₂ reveal a twofold enhancement of the “hidden-order” (HO)/large-moment antiferromagnetic (LMAFM) phase boundary T₀(x). The T₀(Pch) curve, obtained by converting x to “chemical pressure” Pch, is strikingly similar to the T₀(P) curve, where P is applied pressure, for URu₂Si₂ both exhibit a “kink” at 1.5 GPa and a maximum at ~7 GPa. This similarity suggests that the HO-LMAFM transition at 1.5 GPa in URu₂Si₂ occurs at x ≈ 0.2 (Pch≈1.5 GPa) in URu2-xFexSi₂. URu2-xFexSi₂ provides an opportunity for studying the HO and LMAFM phases with methods that probe the electronic structure [e.g., scanning tunneling microscopy (STM), angle-resolved photoemission spectroscopy (ARPES), and point-contact spectroscopy (PCS)] but cannot be used under pressure.

  2. Phase transfer membrane supported liquid-liquid-liquid microextraction combined with large volume sample injection capillary electrophoresis-ultraviolet detection for the speciation of inorganic and organic mercury.

    PubMed

    Li, Pingjing; Zhang, Xing; Hu, Bin

    2011-12-30

    In this paper, a novel sample pretreatment technique termed phase transfer based liquid-liquid-liquid microextraction (PT-LLLME) was proposed for the simultaneous extraction of inorganic and organic mercury species. In PT-LLLME, an intermediate solvent (acetonitrile) was added into the donor phase to improve the contacting between target mercury species and complexing reagent. Meanwhile, a membrane supported (MS)-LLLME unit was designed to realize the PT-LLLME procedure. By using nylon membrane as supporting carrier, larger than 50 μL of acceptor solution could be hung up. Following PT/MS-LLLME, the acceptor solutions were directly analyzed by large volume sample stacking capillary electrophoresis/ultraviolet detection (LVSS-CE/UV). Accordingly, a new method of PT/MS-LLLME combined with LVSS-CE/UV was developed for the simultaneous speciation of inorganic and organic mercury species. Parameters affecting the extraction efficiency of PT/MS-LLLME were investigated in details. Under the optimized conditions, enrichment factors (EFs) ranging from 160- to 478-fold were obtained for the extraction of target mercury species by PT/MS-LLLME. By combining PT/MS-LLLME with LVSS-CE/UV, EFs were magnified up to 12,138-fold and the limits of detection (at a signal-to-noise ratio of 3) were at sub ppb level. The established approach of PT/MS-LLLME-LVSS-CE/UV was successfully applied to simultaneous determination of inorganic and organic mercury species in biological samples and environmental water samples.

  3. Analysis of iodinated haloacetic acids in drinking water by reversed-phase liquid chromatography/electrospray ionization/tandem mass spectrometry with large volume direct aqueous injection.

    PubMed

    Li, Yongtao; Whitaker, Joshua S; McCarty, Christina L

    2012-07-06

    A large volume direct aqueous injection method was developed for the analysis of iodinated haloacetic acids in drinking water by using reversed-phase liquid chromatography/electrospray ionization/tandem mass spectrometry in the negative ion mode. Both the external and internal standard calibration methods were studied for the analysis of monoiodoacetic acid, chloroiodoacetic acid, bromoiodoacetic acid, and diiodoacetic acid in drinking water. The use of a divert valve technique for the mobile phase solvent delay, along with isotopically labeled analogs used as internal standards, effectively reduced and compensated for the ionization suppression typically caused by coexisting common inorganic anions. Under the optimized method conditions, the mean absolute and relative recoveries resulting from the replicate fortified deionized water and chlorinated drinking water analyses were 83-107% with a relative standard deviation of 0.7-11.7% and 84-111% with a relative standard deviation of 0.8-12.1%, respectively. The method detection limits resulting from the external and internal standard calibrations, based on seven fortified deionized water replicates, were 0.7-2.3 ng/L and 0.5-1.9 ng/L, respectively.

  4. Catalytic Metallodrugs Based on the LaR2C Peptide Target HCV SLIV IRES RNA

    PubMed Central

    Ross, Martin James; Bradford, Seth S.; Cowan, J. A.

    2015-01-01

    Prior work has demonstrated the potential effectiveness of a new class of metallopeptides as catalytic metallodrugs that target HCV IRES SLIIb RNA (Cu-GGHYrFK, 1). Herein new catalytic metallodrugs (GGHKYKETDLLILFKDDYFAKKNEERK, 2; and GGHKYKETDL, 3) are described based on the LaR2C peptide that has been shown to bind to the SLIV HCV IRES domain. In vitro fluorescence assays yielded KD values ~10 μM for both peptides and reaction of the copper derivatives with SLIV RNA demonstrated initial rates comparable across different assays as well as displaying pseudo-Michaelis-Menten behavior. The sites of reaction and cleavage mechanisms were determined by MALDI-TOF mass spectrometry. The primary site of copper-promoted SLIV cleavage is shown to occur in the vicinity of the 5’-G17C18A19C20-3’ sequence that corresponds to a known binding site of the RM2 motif of the human La protein and has previously been reported to be important for viral translation. This domain also flanks the internal start codon (AUG). Both copper complexes also showed efficacy in an HCV replicon assay (IC50 = 0.75 μM for 2-Cu, and 2.17 μM for 3-Cu) and show potential for treatment of hepatitis C, complementing other marketed drugs by acting on a distinct therapeutic target by a novel mechanism of action. PMID:26583601

  5. Translational research needs us to go back to basics and collaborate: interview with Lars Sundstrom

    PubMed Central

    Sundstrom, Lars

    2016-01-01

    Lars Sundstrom is Director of Enterprise and Translation at the West of England Academic Health Sciences Network [1] (UK), a Professor of Practice in Translational Medicine and Co-Director of the Elizabeth Blackwell Institute for Health Research at Bristol University [2] (UK), and an honorary Professor of Medicine at Cardiff University (UK). He has extensive experience in translational medicine and clinical neurosciences, holding positions at several eminent universities. He has also held executive and board-level positions at several SMEs, developing new therapeutics for neurological conditions and tools for drug discovery. He has also been an advisor to several UK and local government task forces and to the European Commission and the European Federation of Pharmaceutical Industry Associations. He was a founding member of the European Brain Council in Brussels, and set up the Severnside Alliance for Translational Research, developing a regional network partnership to link clinical and basic scientists. He was also involved in the creation of Health Research Wales. PMID:28031978

  6. Fatal human herpesvirus type 1 infection in a white-handed gibbon (Hylobates lar).

    PubMed

    Landolfi, Jennifer A; Wellehan, James F X; Johnson, April J; Kinsel, Michael J

    2005-07-01

    This report documents a case of spontaneous, fatal, and likely recrudescent human herpesvirus type 1 (HHV-1) infection in a captive white-handed gibbon (Hylobates lar) confirmed by polymerase chain reaction (PCR). An approximately 44-year-old, captive, female, white-handed gibbon with a history of recurrent conjunctivitis and occasional seizures became acutely weak, disoriented, and ataxic. A postictal state was suspected by caretakers and veterinary staff, and euthanasia was ultimately elected because of lack of clinical improvement with supportive care. No significant abnormalities were detected at necropsy. Histologically, sections of cerebrum and midbrain contained minimal to mild, multifocal lymphoplasmacytic meningoencephalitis with numerous intranuclear viral inclusions within astrocytes and some neurons. The presumptive diagnosis of HHV-1-induced encephalitis was strengthened by nested PCR amplification of a segment of the herpesvirus DNA polymerase gene. Sequences from this region have been found to be unique to each herpesvirus species, thus identifying HHV-1 as the likely etiologic agent in this case. Positive HHV-1 serology from several years before the terminal episode suggested that the disease was most likely due to recrudescence of latent HHV-1 infection.

  7. Large field-of-view asymmetric masks for high-energy x-ray phase imaging with standard x-ray tube

    NASA Astrophysics Data System (ADS)

    Endrizzi, M.; Astolfo, A.; Price, B.; Haig, I.; Olivo, A.

    2016-09-01

    We report on a new approach to large field-of-view laboratory-based X-ray phase-contrast imaging. The method is based upon the asymmetric mask design that enables the retrieval of the absorption, refraction and ultra-small- angle scattering properties of the sample without the need to move any component of the imaging system. The sample is scanned through the imaging system, which also removes possible aliasing problems that might arise from partial sample illumination when using the edge illumination technique. This concept can be extended to any desired number of apertures providing, at the same time, intensity projections at complementary illumination conditions. Experimental data simultaneously acquired at seven different illumination fractions are presented along with the results obtained from a numerical model that incorporates the actual detector performance. The ultimate shape of the illumination function is shown to be significantly dependent on these detector-specific characteristics. Based on this concept, a large field-of-view system was designed, which is also capable to cope with relatively high (100 kVp) X-ray energies. The imaging system obtained in this way, where the asymmetric mask design enables the data to be collected without moving any element of the instrumentation, adapts particularly well to those situations in medical, industrial and security imaging where the sample has to be scanned through the system.

  8. On-line immunoaffinity solid-phase extraction capillary electrophoresis mass spectrometry for the analysis of large biomolecules: a preliminary report.

    PubMed

    Medina-Casanellas, Silvia; Benavente, Fernando; Giménez, Estela; Barbosa, José; Sanz-Nebot, Victoria

    2014-08-01

    The analysis of large biomolecules by on-line immunoaffinity solid-phase extraction capillary electrophoresis mass spectrometry (IA-SPE-CE-MS) remains unexplored because of the complex issues that need to be addressed. In this preliminary study, we used the human glycoprotein transferrin (Tf) as a model of a large biomolecule. First, we established by CE-UV a novel method compatible with IA-SPE-CE-MS, based on the use of a fused silica capillary coated with an anionic derivative of polyacrylamide (UltraTrol(TM) Dynamic Pre-Coat High Normal, HN) to prevent protein adsorption. The methodology allowed the detection of the most abundant Tf sialoforms. Repeatability studies demonstrated high stability of the coated capillaries, which was required for on-line immunoextraction and MS detection. IA-SPE-CE-UV and IA-SPE-CE-MS methods were optimized for the analysis of Tf standards and human serum samples using a laboratory-made IA sorbent. Three peaks corresponding to Tf were detected with UV detection when on-line immunoextraction was applied to the standards. The use of MS detection, however, reduced the resolution of the electrophoretic separation. Finally, we demonstrated that it was possible to detect Tf in human serum samples, after off-line serum sample de-salting by centrifugal filtration.

  9. LAR tyrosine phosphatase receptor: alternative splicing is preferential to the nervous system, coordinated with cell growth and generates novel isoforms containing extensive CAG repeats

    PubMed Central

    1995-01-01

    Receptor-linked tyrosine phosphatases regulate cell growth by dephosphorylating proteins involved in tyrosine kinase signal transduction. The leukocyte common antigen-related (LAR) tyrosine phosphatase receptor has sequence similarity to the neural cell adhesion molecule N-CAM and is located in a chromosomal region (1p32- 33) frequently altered in neuroectodermal tumors. To understand the function of receptor-linked tyrosine phosphatases in neural development, we sought to identify LAR isoforms preferentially expressed in the nervous system and cellular processes regulating LAR alternative splicing. We report here the isolation of a series of rat LAR cDNA clones arising from complex combinatorial alternative splicing, not previously demonstrated for the tyrosine phosphatase- receptor gene family in general. Isoforms included: (a) deletions of the fourth, sixth and seventh fibronectin type III-like domains; (b) an alternatively spliced novel cassette exon in the fifth fibronectin type III-like domain; (c) two alternatively spliced novel cassette exons in the juxtamembrane region; (d) a retained intron in the extracellular region with in-frame stop codons predicting a secreted LAR isoform; and (e) an LAR transcript including an alternative 3' untranslated region containing multiple stretches of tandem CAG repeats up to 21 repeats in length. This number of repeats was in the range found in normal alleles of genes in which expansions of repeats are associated with neurodegenerative disease and the genetic phenomenon of anticipation. RT-PCR and Northern analysis demonstrated that LAR alternative splicing occurred preferentially in neuromuscular tissue in vivo and in neurons compared to astrocytes in vitro and was developmentally regulated. Alternative splicing was also regulated in PC12 cells by NGF, in 3T3 fibroblasts by cell confluence and in sciatic nerve and muscle subsequent to nerve transection. Western blot analysis demonstrated that alternatively spliced

  10. Phase-I trigger readout electronics upgrade of the ATLAS liquid-argon calorimeters

    NASA Astrophysics Data System (ADS)

    Mori, Tatsuya

    2016-09-01

    This article gives an overview of the Phase-I Upgrade of the ATLAS LAr Calorimeter Trigger Readout. The design of custom developed hardware for fast real-time data processing and transfer are presented. Performance results from the prototype boards operated in the demonstrator system, first measurements of noise behavior and responses on the test pulses to the demonstrator system are shown.

  11. Optical readout of a two phase liquid argon TPC using CCD camera and THGEMs

    NASA Astrophysics Data System (ADS)

    Mavrokoridis, K.; Ball, F.; Carroll, J.; Lazos, M.; McCormick, K. J.; Smith, N. A.; Touramanis, C.; Walker, J.

    2014-02-01

    This paper presents a preliminary study into the use of CCDs to image secondary scintillation light generated by THick Gas Electron Multipliers (THGEMs) in a two phase LAr TPC. A Sony ICX285AL CCD chip was mounted above a double THGEM in the gas phase of a 40 litre two-phase LAr TPC with the majority of the camera electronics positioned externally via a feedthrough. An Am-241 source was mounted on a rotatable motion feedthrough allowing the positioning of the alpha source either inside or outside of the field cage. Developed for and incorporated into the TPC design was a novel high voltage feedthrough featuring LAr insulation. Furthermore, a range of webcams were tested for operation in cryogenics as an internal detector monitoring tool. Of the range of webcams tested the Microsoft HD-3000 (model no:1456) webcam was found to be superior in terms of noise and lowest operating temperature. In ambient temperature and atmospheric pressure 1 ppm pure argon gas, the THGEM gain was ≈ 1000 and using a 1 msec exposure the CCD captured single alpha tracks. Successful operation of the CCD camera in two-phase cryogenic mode was also achieved. Using a 10 sec exposure a photograph of secondary scintillation light induced by the Am-241 source in LAr has been captured for the first time.

  12. Phase stability and large in-plane resistivity anisotropy in the 112-type iron-based superconductor Ca1 -xLaxFeAs2

    NASA Astrophysics Data System (ADS)

    Kang, Chang-Jong; Birol, Turan; Kotliar, Gabriel

    2017-01-01

    The recently discovered high-Tc superconductor Ca1 -xLaxFeAs2 is a unique compound not only because of its low-symmetry crystal structure but also because of its electronic structure, which hosts Dirac-like metallic bands resulting from (spacer) zigzag As chains. We present a comprehensive first-principles theoretical study of the electronic and crystal structures of Ca1 -xLaxFeAs2 . After discussing the connection between the crystal structure of the 112 family, which Ca1 -xLaxFeAs2 is a member of, with the other known structures of Fe pnictide superconductors, we check the thermodynamic phase stability of CaFeAs2, and similar hyphothetical compounds SrFeAs2 and BaFeAs2 which, we find, are slightly higher in energy. We calculate the optical conductivity of Ca1 -xLaxFeAs2 using the DFT+DMFT method and predict a large in-plane resistivity anisotropy in the normal phase, which does not originate from electronic nematicity, but is enhanced by the electronic correlations. In particular, we predict a 0.34 eV peak in the y y component of the optical conductivity of the 30% La-doped compound, which corresponds to coherent interband transitions within a fast-dispersing band arising from the zigzag As chains, which are unique to this compound. We also study the Landau free energy for Ca1 -xLaxFeAs2 including the order parameter relevant for the nematic transition and find that the free energy does not have any extra terms that could induce ferro-orbital order. This explains why the presence of As chains does not broaden the nematic transition in Ca1 -xLaxFeAs2 .

  13. Histological reconstruction of dental development and age at death in a juvenile gibbon (Hylobates lar).

    PubMed

    Dirks, W

    1998-01-01

    Although research on dental development in great apes and modern humans has provided comparative models for life history, growth and development in hominin evolution, almost nothing is known about dental development in their sister group, the hylobatids. Hylobatids are of interest because they differ in important life history variables from other catarrhines of similar body mass, and can help to provide more general models for the factors underlying patterns of dental development. This study uses histological techniques to reconstruct developmental sequence, crown formation times, root extension rates, daily rates of enamel and dentine formation, and age at death in a single specimen of Hylobates lar. Thin sections were prepared of permanent mandibular teeth and analyzed by polarized light microscopy. Age at death was determined to be 2.88 yrs calibrated from a pattern of accentuated growth increments. At this age, permanent teeth in occlusion include I1, I2, and M1. Developing permanent teeth include C1, P3, P4, and M2. P3 lags behind P4 in development, and there is no indication of M3 present in the crypt. Differences between the gibbon specimen and great apes include greater prenatal development of M1, accelerated incisor development relative to molars and prenatal development of I1, no overlap between M2 and M3 crown development, shorter crown formation times, and slower root extension rates of 4-5 micron daily in the molars. Root extension rates are higher in the incisors. The periodicity of growth increments is four days, more similar to macaques than to other hominoids. Daily formation rates for enamel of 1.2-4.9 micron and dentine of 1.7-4.9 micron are similar to those reported for other catarrhines.

  14. Developing large-scale forcing data for single-column and cloud-resolving models from the Mixed-Phase Arctic Cloud Experiment

    SciTech Connect

    Xie, Shaocheng; Klein, Stephen A.; Zhang, Minghua; Yio, John J.; Cederwall, Richard T.; McCoy, Renata

    2006-10-05

    [1] This study represents an effort to develop Single-Column Model (SCM) and Cloud-Resolving Model large-scale forcing data from a sounding array in the high latitudes. An objective variational analysis approach is used to process data collected from the Atmospheric Radiation Measurement Program (ARM) Mixed-Phase Arctic Cloud Experiment (M-PACE), which was conducted over the North Slope of Alaska in October 2004. In this method the observed surface and top of atmosphere measurements are used as constraints to adjust the sounding data from M-PACE in order to conserve column-integrated mass, heat, moisture, and momentum. Several important technical and scientific issues related to the data analysis are discussed. It is shown that the analyzed data reasonably describe the dynamic and thermodynamic features of the Arctic cloud systems observed during M-PACE. Uncertainties in the analyzed forcing fields are roughly estimated by examining the sensitivity of those fields to uncertainties in the upper-air data and surface constraints that are used in the analysis. Impacts of the uncertainties in the analyzed forcing data on SCM simulations are discussed. Results from the SCM tests indicate that the bulk features of the observed Arctic cloud systems can be captured qualitatively well using the forcing data derived in this study, and major model errors can be detected despite the uncertainties that exist in the forcing data as illustrated by the sensitivity tests. Lastly, the possibility of using the European Center for Medium-Range Weather Forecasts analysis data to derive the large-scale forcing over the Arctic region is explored.

  15. Developing large-scale forcing data for single-column and cloud-resolving models from the Mixed-Phase Arctic Cloud Experiment

    DOE PAGES

    Xie, Shaocheng; Klein, Stephen A.; Zhang, Minghua; ...

    2006-10-05

    [1] This study represents an effort to develop Single-Column Model (SCM) and Cloud-Resolving Model large-scale forcing data from a sounding array in the high latitudes. An objective variational analysis approach is used to process data collected from the Atmospheric Radiation Measurement Program (ARM) Mixed-Phase Arctic Cloud Experiment (M-PACE), which was conducted over the North Slope of Alaska in October 2004. In this method the observed surface and top of atmosphere measurements are used as constraints to adjust the sounding data from M-PACE in order to conserve column-integrated mass, heat, moisture, and momentum. Several important technical and scientific issues related tomore » the data analysis are discussed. It is shown that the analyzed data reasonably describe the dynamic and thermodynamic features of the Arctic cloud systems observed during M-PACE. Uncertainties in the analyzed forcing fields are roughly estimated by examining the sensitivity of those fields to uncertainties in the upper-air data and surface constraints that are used in the analysis. Impacts of the uncertainties in the analyzed forcing data on SCM simulations are discussed. Results from the SCM tests indicate that the bulk features of the observed Arctic cloud systems can be captured qualitatively well using the forcing data derived in this study, and major model errors can be detected despite the uncertainties that exist in the forcing data as illustrated by the sensitivity tests. Lastly, the possibility of using the European Center for Medium-Range Weather Forecasts analysis data to derive the large-scale forcing over the Arctic region is explored.« less

  16. Large scale motions of Neptune's bow shock: Evidence for control of the shock position by the rotation phase of Neptune's magnetic field

    NASA Technical Reports Server (NTRS)

    Cairns, Iver H.; Smith, Charles W.; Kurth, William S.; Gurnett, Donald A.; Moses, Stewart L.

    1991-01-01

    The Voyager 2 spacecraft observed high levels of Langmuir waves before the inbound crossing of Neptune's bow shock, thereby signifying magnetic connection of the bow shock. The Langmuir waves occurred in multiple bursts throughout two distinct periods separated by an 85 minute absence of wave activity. The times of onsets, peaks, and disappearances of the waves were used together with the magnetic field directions and spacecraft position, to perform a 'remote-sensing' analysis of the shape and location of Neptune's bow shock prior to the inbound bow shock crossing. The bow shock is assumed to have a parabolidal shape with a nose location and flaring parameter determined independently for each wave event. The remote-sensing analysis give a shock position consistent with the time of the inbound shock crossing. The flaring parameter of the shock remains approximately constant throughout each period of wave activity but differs by a factor of 10 between the two periods. The absence of waves between two periods of wave activity coincides with a large rotation of the magnetic field and a large increase in the solar wind ram pressure' both these effects lead to magnetic disconnection of the spacecraft from shock. The planetwards motion of the shock's nose from 38.5 R(sub N) to 34.5 R(sub N) during the second time period occurred while the solar wind ram pressure remained constant to within 15 percent. This second period of planetwards motion of the shock is therefore strong evidence for Neptune's bow shock moving in response to the rotation of Neptune's oblique, tilted magnetic dipole. Normalizing the ram pressure, the remotely-sensed shock moves sunwards during the first wave period and planetwards in the second wave period. The maximum standoff distance occurs while the dipole axis is close to being perpendicular to the Sun-Neptune direction. The remote-sensing analysis provides strong evidence that the location of Neptune's bow shock is controlled by Neptune's rotation

  17. Assessment of a novel device for onsite integrative large-volume solid phase extraction of water samples to enable a comprehensive chemical and effect-based analysis.

    PubMed

    Schulze, Tobias; Ahel, Marijan; Ahlheim, Jörg; Aït-Aïssa, Selim; Brion, François; Di Paolo, Carolina; Froment, Jean; Hidasi, Anita O; Hollender, Juliane; Hollert, Henner; Hu, Meng; Kloß, Anett; Koprivica, Sanja; Krauss, Martin; Muz, Melis; Oswald, Peter; Petre, Margit; Schollée, Jennifer E; Seiler, Thomas-Benjamin; Shao, Ying; Slobodnik, Jaroslav; Sonavane, Manoj; Suter, Marc J-F; Tollefsen, Knut Erik; Tousova, Zuzana; Walz, Karl-Heinz; Brack, Werner

    2017-03-01

    The implementation of targeted and nontargeted chemical screening analysis in combination with in vitro and organism-level bioassays is a prerequisite for a more holistic monitoring of water quality in the future. For chemical analysis, little or no sample enrichment is often sufficient, while bioanalysis often requires larger sample volumes at a certain enrichment factor for conducting comprehensive bioassays on different endpoints or further effect-directed analysis (EDA). To avoid logistic and technical issues related to the storage and transport of large volumes of water, sampling would benefit greatly from onsite extraction. This study presents a novel onsite large volume solid phase extraction (LVSPE) device tailored to fulfill the requirements for the successful effect-based and chemical screening of water resources and complies with available international standards for automated sampling devices. Laboratory recovery experiments using 251 organic compounds in the log D range from -3.6 to 9.4 (at pH7.0) spiked into pristine water resulted in acceptable recoveries and from 60 to 123% for 159 out of 251 substances. Within a European-wide demonstration program, the LVSPE was able to enrich compounds in concentration ranges over three orders of magnitude (1ngL(-1) to 2400ngL(-1)). It was possible to discriminate responsive samples from samples with no or only low effects in a set of six different bioassays (i.e. acetylcholinesterase and algal growth inhibition, androgenicity, estrogenicity, fish embryo toxicity, glucocorticoid activity). The LVSPE thus proved applicable for onsite extraction of sufficient amounts of water to investigate water quality thoroughly by means of chemical analysis and effect-based tools without the common limitations due to small sample volumes.

  18. Enhanced detection of nitroaromatic explosive vapors combining solid-phase extraction-air sampling, supercritical fluid extraction, and large-volume injection-GC.

    PubMed

    Batlle, Ramón; Carlsson, Håkan; Tollbäck, Petter; Colmsjö, Anders; Crescenzi, Carlo

    2003-07-01

    A complete method for sampling and analyzing of energetic compounds in the atmosphere is described. The method consists of the hyphenation of several techniques: active air sampling using a solid-phase extraction cartridge to collect the analytes, extraction of the sorbed analytes by toluene/methyl tert-butyl ether modified supercritical fluid extraction (SFE), and analysis of the extract by large-volume injection GC-nitrogen/phosphorus detection. The GC system is equipped with a loop-type injection interface with an early solvent vapor exit, a utilizing concurrent solvent evaporation technique. Chemometric approaches, based on a Plackett-Burman screening design and a central composite design for response surface modeling, were used to determine the optimum SFE conditions. The relative standard deviations of the optimized method were determined to be 4.3 to 7.7%, giving raise to method detection limits ranging from 0.06 to 0.36 ng in the sampling cartridge, equivalent to 6.2-36.4 pg/L in the atmosphere, standard sampling volume 10 L. The analytical method was applied to characterize headspace composition above military grade trinitrotoluene (TNT). Results confirm that 2,4-dinitrotoluene (DNT) and 1,3-dinitrobenzene (DNB) constitute the largest vapor flux, but TNT, 2,6-DNT, and trinitrobenzene TNB were also consistently detected in all the samples.

  19. Rapid and sensitive solid phase extraction-large volume injection-gas chromatography for the analysis of mineral oil saturated and aromatic hydrocarbons in cardboard and dried foods.

    PubMed

    Moret, Sabrina; Barp, Laura; Purcaro, Giorgia; Conte, Lanfranco S

    2012-06-22

    A rapid off-line solid phase extraction-large volume injection-gas chromatography-flame ionisation detection (SPE-LVI-GC-FID) method, based on the use of silver silica gel and low solvent consumption, was developed for mineral oil saturated hydrocarbon (MOSH) and mineral oil aromatic hydrocarbon (MOAH) determination in cardboard and dried foods packaged in cardboard. The SPE method was validated using LVI with a conventional on-column injector and the retention gap technique (which allowed to inject up to 50 μL of the sample). Detector response was linear over all the concentration range tested (0.5-250 μg/mL), recoveries were practically quantitative, repeatability was good (coefficients of variation lower than 7%) and limit of quantification adequate to quantify the envisioned limit of 0.15 mg/kg proposed in Germany for MOAH analysis in food samples packaged in recycled cardboard. Rapid heating of the GC oven allowed to increase sample throughput (3-4 samples per hour) and to enhance sensitivity. The proposed method was used for MOSH and MOAH determination in selected food samples usually commercialised in cardboard packaging. The most contaminated was a tea sample (102.2 and 7.9 mg/kg of MOSH and MOAH below n-C25, respectively), followed by a rice and a sugar powder sample, all packaged in recycled cardboard.

  20. Qualitative and quantitative reversed-phase high performance liquid chromatographic analysis of glycoprotein hormones in the presence of a large excess of human serum albumin.

    PubMed

    Almeida, B E; Oliveira, J E; Damiani, R; Dalmora, S L; Bartolini, P; Ribela, M T C P

    2012-04-07

    The present work describes reversed-phase high performance liquid chromatographic methodologies (RP-HPLC) for the qualitative and quantitative analysis of the human glycoprotein hormones thyrotropin (hTSH), follitropin (hFSH), choriogonadotropin (hCG) and lutropin (hLH) in the presence of a large excess (up to 250:1) of human serum albumin (HSA). Chromatographic profiles with a good separation between the hormone and HSA were obtained by using a C4 column and specific gradient elution conditions for each hormone. Parameters such as resolution factor, tailing factor and relative retention time, were determined, and are useful for the evaluation of the quality of the separation obtained between the active pharmaceutical ingredient and the excipient present in the final formulation. The potential of each method for quantification of both HSA and the hormone was also demonstrated. Besides furnishing chromatographic quantifications that can substitute for in vivo bioassays and animal use, the chromatograms also provide a direct panorama of the quality and heterogeneity of the protein of interest.

  1. Determination of polybrominated diphenyl ethers and polychlorinated biphenyls in fishery and aquaculture products using sequential solid phase extraction and large volume injection gas chromatography/tandem mass spectrometry.

    PubMed

    Lu, Dasheng; Lin, Yuanjie; Feng, Chao; Wang, Dongli; Qiu, Xinlei; Jin, Yu'e; Xiong, Libei; Jin, Ying; Wang, Guoquan

    2014-01-15

    A new method was developed to determine polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in fishery and aquaculture products. Samples were extracted by an accelerated solvent extraction system and cleaned up by sequential solid phase extraction (SPE) including dispersive SPE (D-SPE) and tandem SPE. PBDEs and PCBs were analyzed by a large-volume injection gas chromatography triple quadrupole mass spectrometry (LVI-GC-QqQ-MS/MS). Good linearity (R(2)≥0.9958) was achieved. Method detection limits (MDLs) were 0.16-3.3pgg(-1) (wet weight, ww) for PBDEs and 0.13-0.97pgg(-1)ww for PCBs. Mean recoveries were 60-140% with relative standard deviations (RSDs) of less than 20% in weever fish, scallop and shrimp samples spiked at a lower level of 13-31pgg(-1)ww and a higher level of 50-125pgg(-1)ww. Certified reference materials were analyzed with acceptable results. The method reduced solvent consumption, analytical time and labor, and is suitable for the routine analysis of PBDEs and PCBs in fishery and aquaculture products.

  2. Metastable tetragonal Cu2Se hyperbranched structures: large-scale preparation and tunable electrical and optical response regulated by phase conversion.

    PubMed

    Zhu, Jinbao; Li, Qiuyang; Bai, Liangfei; Sun, Yongfu; Zhou, Min; Xie, Yi

    2012-10-08

    Despite the promising applications of copper selenide nanoparticles, an in-depth elucidation of the inherent properties of tetragonal Cu(2)Se (β-Cu(2)Se) has not been performed because of the lack of a facile synthesis on the nanoscale and an energy-intensive strategy is usually employed. In this work, a facile wet-chemical strategy, employing HCOOH as reducing agent, has been developed to access single-crystalline metastable β-Cu(2)Se hyperbranched architectures for the first time. The process avoids hazardous chemistry and high temperatures, and thus opens up a facile approach to the large-scale low-cost preparation of metastable β-Cu(2)Se hyperbranched architectures. A possible growth mechanism to explain the formation of the β-Cu(2)Se dendritic morphology has been proposed based on time-dependent shape evolution. Further investigations revealed that the metastable β-Cu(2)Se can convert into the thermodynamically more stable cubic α-Cu(2-x)Se maintaining the dendritic morphology. An increase in electrical conductivity and a tunable optical response were observed under ambient conditions. This behavior can be explained by the oxidation of the surface of the β-Cu(2)Se hyperbranched structures, ultimately leading to solid-state phase conversion from β-Cu(2)Se into superionic conductor α-Cu(1.8)Se, which has potential applications in energy-related devices and sensors.

  3. Two-phase flow regimes and carry-over in a large-diameter model of a PWR hot leg. Final report

    SciTech Connect

    Hashemi, A.

    1986-04-01

    This report describes a series of tests investigating two-phase flow characterization and carryover in a transparent model of a Babcock and Wilson (B and W) Pressurized Water Reactor (PWR) hot leg geometry. This work was performed, inpart, to support the interpretation of results from the Once-Through Integral System (OTIS) and Multi-loop Integral Test (MIST) facilities. Test conditions were selected to cover a wide range of gas and liquid superficial velocities (0.01 m/s < j/sub g/ < 2 m/s, 0 < j/sub l/ < 0.5 m/s) expected to occur in a prototypical reactor geometry during a small break loss of coolant accident (SBLOCA). Tests at high gas superficial velocities (j/sub g/ > 2 m/s) were also performed for comparison with semi-analytical predictions. Tests were conducted in two different test rigs, one with 10.2-cm (4-inch) diameter pipe, and the other with 30.5-cm (12-inch) diameter pipe. Results include average void fraction, amount of water carryover through the U-bend, transient flow rates and pressure histories, and video movies of the two-phase flow phenomena. Results of the 10.2-cm (4-inch) pipe tests show generally good agreement with the Taitel and Dukler (1) flow regime map for vertical pipes. For the 30.5-cm pipe tests, slug flow was not observed. Instead, as the air flow rate was increased, the flow regime progressed from bubbly to churn-type flow with the presence of large bubbles (approximately 15-cm diameter). The results also indicate that flow regimes and collapsed liquid level are more strongly dependent on air superficial velocity than the water superficial velocity and that the amount of water carryover for a given air flow rate is a strong function of collapsed water level (void fraction). Furthermore, the results show that similar thresholds for breakdown in natural circulation flow exist between the 10.2-cm and 30.5-cm pipe tests for gas and liquid superficial velocities expected in a SBLOCA. 20 refs., 24 figs.

  4. Phase 2 study of the bispecific T-cell engager (BiTE) antibody blinatumomab in relapsed/refractory diffuse large B-cell lymphoma

    PubMed Central

    Goebeler, Marie-Elisabeth; Hess, Georg; Neumann, Svenja; Pfreundschuh, Michael; Adrian, Nicole; Zettl, Florian; Libicher, Martin; Sayehli, Cyrus; Stieglmaier, Julia; Zhang, Alicia; Nagorsen, Dirk; Bargou, Ralf C.

    2016-01-01

    Few patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) achieve prolonged disease-free survival. Blinatumomab, a bispecific T-cell engaging antibody construct, transiently links CD3-positive T cells to CD19-positive B cells. This phase 2 study evaluated stepwise (9-28-112 μg/d with weekly dose increases; n = 23) or flat (112 μg/d; n = 2) dosing of blinatumomab by continuous infusion, with dexamethasone prophylaxis, in patients with relapsed/refractory DLBCL. Patients received a median of 3 prior lines of therapy. Median time since last regimen was 1.5 months. Seventeen patients ended treatment in cycle 1 (induction), 7 in cycle 2 (consolidation), and 1 in retreatment. Among 21 evaluable patients, the overall response rate after 1 blinatumomab cycle was 43%, including complete responses (CRs) in 19%. Three patients had late CR in follow-up without other treatment. The most common adverse events with stepwise dosing were tremor (48%), pyrexia (44%), fatigue (26%), and edema (26%). Grade 3 neurologic events with stepwise dosing were encephalopathy and aphasia (each 9%) and tremor, speech disorder, dizziness, somnolence, and disorientation (each 4%). Of 5 (22%) patients who discontinued stepwise dosing because of adverse events, 4 (17%) had neurologic events. Most neurologic events resolved. The flat-dose cohort was stopped because of grade 3 neurologic events in both patients. Blinatumomab monotherapy appears effective in patients with relapsed/refractory DLBCL, a heavily pretreated patient population with a high unmet medical need. Further studies need to define the optimal approach to achieve the target dose without early dropout. The study was registered at www.clinicaltrials.gov as #NCT01741792. PMID:26755709

  5. The physiological concentration of ferrous iron (II) alters the inhibitory effect of hydrogen peroxide on CD45, LAR and PTP1B phosphatases.

    PubMed

    Kuban-Jankowska, Alicja; Gorska, Magdalena; Jaremko, Lukasz; Jaremko, Mariusz; Tuszynski, Jack A; Wozniak, Michal

    2015-12-01

    Hydrogen peroxide is an important regulator of protein tyrosine phosphatase activity via reversible oxidation. However, the role of iron in this reaction has not been yet elucidated. Here we compare the influence of hydrogen peroxide and the ferrous iron (reagent for Fenton reaction) on the enzymatic activity of recombinant CD45, LAR, PTP1B phosphatases and cellular CD45 in Jurkat cells. The obtained results show that ferrous iron (II) is potent inhibitor of CD45, LAR and PTP1B, but the inhibitory effect is concentration dependent. We found that the higher concentrations of ferrous iron (II) increase the inactivation of CD45, LAR and PTP1B phosphatase caused by hydrogen peroxide, but the addition of the physiological concentration (500 nM) of ferrous iron (II) has even a slightly preventive effect on the phosphatase activity against hydrogen peroxide.

  6. SALM4 suppresses excitatory synapse development by cis-inhibiting trans-synaptic SALM3–LAR adhesion

    PubMed Central

    Lie, Eunkyung; Ko, Ji Seung; Choi, Su-Yeon; Roh, Junyeop Daniel; Cho, Yi Sul; Noh, Ran; Kim, Doyoun; Li, Yan; Kang, Hyeyeon; Choi, Tae-Yong; Nam, Jungyong; Mah, Won; Lee, Dongmin; Lee, Seong-Gyu; Kim, Ho Min; Kim, Hyun; Choi, Se-Young; Um, Ji Won; Kang, Myoung-Goo; Bae, Yong Chul; Ko, Jaewon; Kim, Eunjoon

    2016-01-01

    Synaptic adhesion molecules regulate various aspects of synapse development, function and plasticity. These functions mainly involve trans-synaptic interactions and positive regulations, whereas cis-interactions and negative regulation are less understood. Here we report that SALM4, a member of the SALM/Lrfn family of synaptic adhesion molecules, suppresses excitatory synapse development through cis inhibition of SALM3, another SALM family protein with synaptogenic activity. Salm4-mutant (Salm4−/−) mice show increased excitatory synapse numbers in the hippocampus. SALM4 cis-interacts with SALM3, inhibits trans-synaptic SALM3 interaction with presynaptic LAR family receptor tyrosine phosphatases and suppresses SALM3-dependent presynaptic differentiation. Importantly, deletion of Salm3 in Salm4−/− mice (Salm3−/−; Salm4−/−) normalizes the increased excitatory synapse number. These results suggest that SALM4 negatively regulates excitatory synapses via cis inhibition of the trans-synaptic SALM3–LAR adhesion. PMID:27480238

  7. Performance study of the effective gain of the double phase liquid Argon LEM Time Projection Chamber

    NASA Astrophysics Data System (ADS)

    Cantini, C.; Epprecht, L.; Gendotti, A.; Horikawa, S.; Periale, L.; Murphy, S.; Natterer, G.; Regenfus, C.; Resnati, F.; Sergiampietri, F.; Rubbia, A.; Viant, T.; Wu, S.

    2015-03-01

    The Large Electron Multipliers (LEMs) are key components of double phase liquid argon TPCs. The drifting charges after being extracted from the liquid are amplified in the LEM positioned half a centimeter above the liquid in pure argon vapor at 87 K. The LEM is characterised by the size of its dielectric rim around the holes, the thickness of the LEM insulator, the diameter of the holes as well as their geometrical layout. The impact of those design parameters on the amplification were checked by testing seven different LEMs with an active area of 10×10 cm2 in a double phase liquid argon TPC of 21 cm drift. We studied their response in terms of maximal reachable gain and impact on the collected charge uniformity as well as the long-term stability of the gain. We show that we could reach maximal gains of around 150 which corresponds to a signal-to-noise ratio (S/N) of about 800 for a minimal ionising particle (MIP) signal on 3 mm readout strips. We could also conclude that the dielectric surfaces in the vicinity of the LEM holes charge up with different time constants that depend on their design parameters. Our results demonstrate that the LAr LEM TPC is a robust concept that is well-understood and well-suited for operation in ultra-pure cryogenic environments and that can match the goals of future large-scale liquid argon detectors.

  8. Embedded Electro-Optic Sensor Network for the On-Site Calibration and Real-Time Performance Monitoring of Large-Scale Phased Arrays

    DTIC Science & Technology

    2005-07-09

    This final report summarizes the progress during the Phase I SBIR project entitled "Embedded Electro - Optic Sensor Network for the On-Site Calibration...sensor network based on an electro - optic field-detection technique (the Electro - optic Sensor Network, or ESN) for the performance evaluation of phased

  9. Effects of gasket on coupled plastic flow and strain-induced phase transformations under high pressure and large torsion in a rotational diamond anvil cell

    NASA Astrophysics Data System (ADS)

    Feng, Biao; Levitas, Valery I.

    2016-01-01

    Combined plastic flow and strain-induced phase transformations (PTs) under high pressure in a sample within a gasket subjected to three dimensional compression and torsion in a rotational diamond anvil cell (RDAC) are studied using a finite element approach. The results are obtained for the weaker, equal-strength, and stronger high-pressure phases in comparison with low-pressure phases. It is found that, due to the strong gasket, the pressure in the sample is relatively homogenous and the geometry of the transformed zones is mostly determined by heterogeneity in plastic flow. For the equal-strength phases, the PT rate is higher than for the weaker and stronger high-pressure phases. For the weaker high-pressure phase, transformation softening induces material instability and leads to strain and PT localization. For the stronger high-pressure phase, the PT is suppressed by strain hardening during PT. The effect of the kinetic parameter k that scales the PT rate in the strain-controlled kinetic equation is also examined. In comparison with a traditional diamond anvil cell without torsion, the PT progress is much faster in RDAC under the same maximum pressure in the sample. Finally, the gasket size and strength effects are discussed. For a shorter and weaker gasket, faster plastic flow in radial and thickness directions leads to faster PT kinetics in comparison with a longer and stronger gasket. The rates of PT and plastic flows are not very sensitive to the modest change in a gasket thickness. Multiple experimental results are reproduced and interpreted. Obtained results allow one to design the desired pressure-plastic strain loading program in the experiments for searching new phases, reducing PT pressure by plastic shear, extracting kinetic properties from experiments with heterogeneous fields, and controlling homogeneity of all fields and kinetics of PTs.

  10. High-Fat Diet Augments VPAC1 Receptor-Mediated PACAP Action on the Liver, Inducing LAR Expression and Insulin Resistance

    PubMed Central

    Nakata, Masanori; Zhang, Boyang; Yang, Yifei; Okada, Takashi; Shintani, Norihito; Hashimoto, Hitoshi

    2016-01-01

    Pituitary adenylate cyclase-activating polypeptide (PACAP) acts on multiple processes of glucose and energy metabolism. PACAP potentiates insulin action in adipocytes and insulin release from pancreatic β-cells, thereby enhancing glucose tolerance. Contrary to these effects at organ levels, PACAP null mice exhibit hypersensitivity to insulin. However, this apparent discrepancy remains to be solved. We aimed to clarify the mechanism underlying the antidiabetic phenotype of PACAP null mice. Feeding with high-fat diet (HFD) impaired insulin sensitivity and glucose tolerance in wild type mice, whereas these changes were prevented in PACAP null mice. HFD also impaired insulin-induced Akt phosphorylation in the liver in wild type mice, but not in PACAP null mice. Using GeneFishing method, HFD increased the leukocyte common antigen-related (LAR) protein tyrosine phosphatase in the liver in wild type mice. Silencing of LAR restored the insulin signaling in the liver of HFD mice. Moreover, the increased LAR expression by HFD was prevented in PACAP null mice. HFD increased the expression of VPAC1 receptor (VPAC1-R), one of three PACAP receptors, in the liver of wild type mice. These data indicate that PACAP-VPAC1-R signaling induces LAR expression and insulin resistance in the liver of HFD mice. Antagonism of VPAC1-R may prevent progression of HFD-induced insulin resistance in the liver, providing a novel antidiabetic strategy. PMID:28044141

  11. Improvements in the processing of large grain, bulk Y-Ba-Cu-O superconductors via the use of additional liquid phase

    NASA Astrophysics Data System (ADS)

    Congreve, Jasmin V. J.; Shi, Yunhua; Dennis, Anthony R.; Durrell, John H.; Cardwell, David A.

    2017-01-01

    A major limitation to the widespread application of Y-Ba-Cu-O (YBCO) bulk superconductors is the relative complexity and low yield of the top seeded melt growth (TSMG) process, by which these materials are commonly fabricated. It has been demonstrated in previous work on the recycling of samples in which the primary growth had failed, that the provision of an additional liquid-rich phase to replenish liquid lost during the failed growth process leads to the reliable growth of relatively high quality recycled samples. In this paper we describe the adaptation of the liquid phase enrichment technique to the primary TSMG fabrication process. We further describe the observed differences between the microstructure and superconducting properties of samples grown with additional liquid-rich phase and control samples grown using a conventional TSMG process. We observe that the introduction of the additional liquid-rich phase leads to the formation of a higher concentration of Y species at the growth front, which leads, in turn, to a more uniform composition at the growth front. Importantly, the increased uniformity at the growth front leads directly to an increased homogeneity in the distribution of the Y-211 inclusions in the superconducting Y-123 phase matrix and to a more uniform Y-123 phase itself. Overall, the provision of an additional liquid-rich phase improves significantly both the reliability of grain growth through the sample thickness and the magnitude and homogeneity of the superconducting properties of these samples compared to those fabricated by a conventional TSMG process.

  12. Injectable controlled release depots for large molecules.

    PubMed

    Schwendeman, Steven P; Shah, Ronak B; Bailey, Brittany A; Schwendeman, Anna S

    2014-09-28

    Biodegradable, injectable depot formulations for long-term controlled drug release have improved therapy for a number of drug molecules and led to over a dozen highly successful pharmaceutical products. Until now, success has been limited to several small molecules and peptides, although remarkable improvements have been accomplished in some of these cases. For example, twice-a-year depot injections with leuprolide are available compared to the once-a-day injection of the solution dosage form. Injectable depots are typically prepared by encapsulation of the drug in poly(lactic-co-glycolic acid) (PLGA), a polymer that is used in children every day as a resorbable suture material, and therefore, highly biocompatible. PLGAs remain today as one of the few "real world" biodegradable synthetic biomaterials used in US FDA-approved parenteral long-acting-release (LAR) products. Despite their success, there remain critical barriers to the more widespread use of PLGA LARproducts, particularly for delivery of more peptides and other large molecular drugs, namely proteins. In this review, we describe key concepts in the development of injectable PLGA controlled-release depots for peptides and proteins, and then use this information to identify key issues impeding greater widespread use of PLGA depots for this class of drugs. Finally, we examine important approaches, particularly those developed in our research laboratory, toward overcoming these barriers to advance commercial LAR development.

  13. Management of fish populations in large rivers: a review of tools and approaches

    USGS Publications Warehouse

    Petts, Geoffrey E.; Imhoff, Jack G.; Manny, Bruce A.; Maher, John F. B.; Weisberg, Stephen B.

    1989-01-01

    In common with most branches of science, the management of riverine fish populations is characterised by reductionist and isolationist philosophies. Traditional fish management focuses on stocking and controls on fishing. This paper presents a concensus of scientists involved in the LARS workshop on the management of fish populations in large rivers. A move towards a more holistic philosophy is advocated, with fish management forming an integral part of sustainable river development. Based upon a questionnaire survey of LARS members, with wide-ranging expertise and experience from all parts of the world, lists of management tools currently in use are presented. Four categories of tools are described: flow, water-quality, habitat, and biological. The potential applications of tools for fish management in large rivers is discussed and research needs are identified. The lack of scientific evaluations of the different tools remains the major constraint to their wider application.

  14. Large Energy Storage Density and High Thermal Stability in a Highly Textured (111)-Oriented Pb0.8Ba0.2ZrO3 Relaxor Thin Film with the Coexistence of Antiferroelectric and Ferroelectric Phases.

    PubMed

    Peng, Biaolin; Zhang, Qi; Li, Xing; Sun, Tieyu; Fan, Huiqing; Ke, Shanming; Ye, Mao; Wang, Yu; Lu, Wei; Niu, Hanben; Zeng, Xierong; Huang, Haitao

    2015-06-24

    A highly textured (111)-oriented Pb0.8Ba0.2ZrO3 (PBZ) relaxor thin film with the coexistence of antiferroelectric (AFE) and ferroelectric (FE) phases was prepared on a Pt/TiOx/SiO2/Si(100) substrate by using a sol-gel method. A large recoverable energy storage density of 40.18 J/cm(3) along with an efficiency of 64.1% was achieved at room temperature. Over a wide temperature range of 250 K (from room temperature to 523 K), the variation of the energy density is within 5%, indicating a high thermal stability. The high energy storage performance was endowed by a large dielectric breakdown strength, great relaxor dispersion, highly textured orientation, and the coexistence of FE and AFE phases. The PBZ thin film is believed to be an attractive material for applications in energy storage systems over a wide temperature range.

  15. Measurement and simulation of two-phase CO2 cooling in Micromegas modules for a Large Prototype of Time Projection Chamber

    NASA Astrophysics Data System (ADS)

    Bhattacharya, D. S.; Attié, D.; Colas, P.; Mukhopadhyay, S.; Majumdar, N.; Bhattacharya, S.; Sarkar, S.; Bhattacharya, A.; Ganjour, S.

    2015-08-01

    The readout electronics of a Micromegas (MM) module consume nearly 26 W of electric power, which causes the temperature of electronic board to increase upto 70 oC. Increase in temperature results in damage of electronics. Development of temperature gradient in the Time Projection Chamber (TPC) may affect precise measurement as well. Two-phase CO2 cooling has been applied to remove heat from the MM modules during two test beam experiments at DESY, Hamburg. Following the experimental procedure, a comprehensive study of the cooling technique has been accomplished for a single MM module by means of numerical simulation. This paper is focused to discuss the application of two-phase CO2 cooling to keep the temperature below 30 oC and stabilized within 0.2 oC.

  16. Large-Size 2D β-Cu2 S Nanosheets with Giant Phase Transition Temperature Lowering (120 K) Synthesized by a Novel Method of Super-Cooling Chemical-Vapor-Deposition.

    PubMed

    Li, Bo; Huang, Le; Zhao, Guangyao; Wei, Zhongming; Dong, Huanli; Hu, Wenping; Wang, Lin-Wang; Li, Jingbo

    2016-10-01

    2D triangular β-Cu2 S nanosheets with large size and high quality are synthesized by a novel method of super-cooling chemical-vapor-deposition. The phase transition of this 2D material from β-Cu2 S to γ-Cu2 S occurs at 258 K (-15 °C), and such transition temperature is 120 K lower than that of its bulk counterpart (about 378 K).

  17. Recovery Act: High-Efficiency, Wideband Three-Phase Rectifiers and Adaptive Rectifier Management for Telecomm Central Office and Large Data Center Applications

    SciTech Connect

    Mark A. Johnson

    2012-06-29

    Lineage Power and Verizon teamed up to address a DOE funding opportunity focused on improving the power conversion chain in telecommunications facilities and data centers. The project had three significant elements: the design and development of high efficiency and high power three-phase rectifiers by Lineage Power, design and development of software to optimize overall plant energy efficiency by Lineage Power, and a field trial in active Verizon telecommunications facilities where energy consumption was measured before and after efficiency upgrades.

  18. The effect of pressure and mobile phase velocity on the retention properties of small analytes and large biomolecules in ultra-high pressure liquid chromatography.

    PubMed

    Fekete, Szabolcs; Veuthey, Jean-Luc; McCalley, David V; Guillarme, Davy

    2012-12-28

    A possible complication of ultra-high pressure liquid chromatography (UHPLC) is related to the effect of pressure and mobile phase velocity on the retention properties of the analytes. In the present work, numerous model compounds have been selected including small molecules, peptides, and proteins (such as monoclonal antibodies). Two instrumental setups were considered to attain elevated pressure drops, firstly the use of a post-column restrictor capillary at low mobile phase flow rate (pure effect of pressure) and secondly the increase of mobile phase flow rate without restrictor (i.e. a combined effect of pressure and frictional heating). In both conditions, the goal was to assess differences in retention behaviour, depending on the type or character of the analyte. An important conclusion is that the effect of pressure and mobile phase velocity on retention varied in proportion with the size of the molecule and in some cases showed very different behaviour. In isocratic mode, the pure effect of pressure (experiments with a post-column restrictor capillary) induces an increase in retention by 25-100% on small molecules (MW<300 g/mol), 150% for peptides (~1.3 kDa), 800% for insulin (~6 kDa) and up to >3000% for myoglobin (~17 kDa) for an increase in pressure from 100 bar up to 1100 bar. The important effect observed for the isocratic elution of proteins is probably related to conformational changes of the protein in addition to the effect of molecular size. Working in gradient elution mode, the pressure related effects on retention were found to be less pronounced but still present (an increase of apparent retention factor between 0.2 and 2.5 was observed).

  19. Correlation between direct dark matter detection and Br(B{sub s}{yields}{mu}{mu}) with a large phase of B{sub s}-B{sub s} mixing

    SciTech Connect

    Dutta, Bhaskar; Mimura, Yukihiro; Santoso, Yudi

    2009-11-01

    We combine the analyses for flavor changing neutral current processes and dark matter solutions in minimal-type supersymmetric grand unified theory models, SO(10) and SU(5), with a large B{sub s}-B{sub s} mixing phase and large tan{beta}. For large tan{beta}, the double-penguin diagram dominates the supersymmetry contribution to the B{sub s}-B{sub s} mixing amplitude. Also, the Br(B{sub s}{yields}{mu}{mu}) constraint becomes important as it grows as tan{sup 6}{beta}, although it can still be suppressed by a large pseudoscalar Higgs mass m{sub A}. We investigate the correlation between B{sub s}{yields}{mu}{mu} and the dark matter direct detection cross section through their dependence on m{sub A}. In the minimal-type of SU(5) with type I seesaw, the large mixing in neutrino Dirac couplings results in a large lepton flavor violating decay process {tau}{yields}{mu}{gamma}, which in turn sets the upper bound on m{sub A}. In the SO(10) case, the large mixing can be chosen to be in the Majorana couplings instead, and the constraint from Br({tau}{yields}{mu}{gamma}) can be avoided. The heavy Higgs funnel region turns out to be an interesting possibility in both cases and the direct dark matter detection should be possible in the near future in these scenarios.

  20. Analysis of rapid increase in the plasma density during the ramp-up phase in a radio frequency negative ion source by large-scale particle simulation.

    PubMed

    Yasumoto, M; Ohta, M; Kawamura, Y; Hatayama, A

    2014-02-01

    Numerical simulations become useful for the developing RF-ICP (Radio Frequency Inductively Coupled Plasma) negative ion sources. We are developing and parallelizing a two-dimensional three velocity electromagnetic Particle-In-Cell code. The result shows rapid increase in the electron density during the density ramp-up phase. A radial electric field due to the space charge is produced with increase in the electron density and the electron transport in the radial direction is suppressed. As a result, electrons stay for a long period in the region where the inductive electric field is strong, and this leads efficient electron acceleration and a rapid increasing of the electron density.

  1. Patterning of self-assembled monolayers by phase-shifting mask and its applications in large-scale assembly of nanowires

    NASA Astrophysics Data System (ADS)

    Gao, Fan; Zhang, Dakuan; Wang, Jianyu; Sheng, Yun; Yan, Shancheng; Wang, Xinran; Chen, Kunji; Shen, Jiancang; Pan, Lijia; Zhou, Minmin; Shi, Yi

    2015-01-01

    A nonselective micropatterning method of self-assembled monolayers (SAMs) based on laser and phase-shifting mask (PSM) is demonstrated. Laser beam is spatially modulated by a PSM, and periodic SAM patterns are generated sequentially through thermal desorption. Patterned wettability is achieved with alternating hydrophilic/hydrophobic stripes on octadecyltrichlorosilane monolayers. The substrate is then used to assemble CdS semiconductor nanowires (NWs) from a solution, obtaining well-aligned NWs in one step. Our results show valuably the application potential of this technique in engineering SAMs for integration of functional devices.

  2. Large-aperture variable-volume view cell for the determination of phase-equilibria in high pressure systems and supercritical fluids

    NASA Astrophysics Data System (ADS)

    Licence, Peter; Dellar, Martin P.; Wilson, Richard G. M.; Fields, Peter A.; Litchfield, David; Woods, Helen M.; Poliakoff, Martyn; Howdle, Steven M.

    2004-10-01

    A high-pressure, variable-volume view cell incorporating a custom engineered, optically transparent sapphire piston is described. The view cell has an unbroken field of vision that enables the entire sample volume to be observed at all times. When lit from the rear of the cell, a near perfect view of any physical transition or change in state is available to the experimenter. The system has been shown to be particularly suitable for the determination of phase equilibria and cloud point measurements in supercritical fluid systems and has been rated for experiments up to 400 bar, 200 °C.

  3. Patterning of self-assembled monolayers by phase-shifting mask and its applications in large-scale assembly of nanowires

    SciTech Connect

    Gao, Fan; Zhang, Dakuan; Wang, Jianyu; Sheng, Yun; Wang, Xinran; Chen, Kunji; Zhou, Minmin; Yan, Shancheng; Shen, Jiancang; Pan, Lijia; Shi, Yi

    2015-01-26

    A nonselective micropatterning method of self-assembled monolayers (SAMs) based on laser and phase-shifting mask (PSM) is demonstrated. Laser beam is spatially modulated by a PSM, and periodic SAM patterns are generated sequentially through thermal desorption. Patterned wettability is achieved with alternating hydrophilic/hydrophobic stripes on octadecyltrichlorosilane monolayers. The substrate is then used to assemble CdS semiconductor nanowires (NWs) from a solution, obtaining well-aligned NWs in one step. Our results show valuably the application potential of this technique in engineering SAMs for integration of functional devices.

  4. The first large area, high X-ray energy phase contrast prototype for enhanced detection of threat object in baggage screening

    NASA Astrophysics Data System (ADS)

    Astolfo, Alberto; Endrizzi, Marco; Price, Benjamin; Haig, Ian; Olivo, Alessandro

    2016-10-01

    X-ray imaging is the most commonly used method in baggage screening. Conventional x-ray attenuation (usually in dual-energy mode) is exploited to discriminate threat and non-threat materials: this is essentially, a method that has seen little changes in decades. Our goal is to demonstrate that x-rays can be used in a different way to achieve improved detection of weapons and explosives. Our approach involves the use of x-ray phase contrast and it a) allows much higher sensitivity in the detection of object edges and b) can be made sensitive to the sample's microstructure. We believe that these additional channels of information, alongside conventional attenuation which would still be available, have the potential to significantly increase both sensitivity and specificity in baggage scanning. We obtained preliminary data demonstrating the above enhanced detection, and we built a scanner (currently in commissioning) to scale the concept up and test it on real baggage. In particular, while previous X-ray phase contrast imaging systems were limited in terms of both field of view (FOV) and maximum x-ray energy, this scanner overcomes both those limitations and provides FOVs up to 20 to 50 cm2 with x-ray energies up to 100 keV.

  5. Lattice model for the SU(N) Néel to valence-bond solid quantum phase transition at large N.

    PubMed

    Kaul, Ribhu K; Sandvik, Anders W

    2012-03-30

    We generalize the SU(N=2) S=1/2 square-lattice quantum magnet with nearest-neighbor antiferromagnetic coupling (J(1)) and next-nearest-neighbor ferromagnetic coupling (J(2)) to arbitrary N. For all N>4, the ground state has valence-bond-solid order for J(2)=0 and Néel order for J(2)/J(1)≫1, allowing us access to the transition between these types of states for large N. Using quantum Monte Carlo simulations, we show that both order parameters vanish at a single quantum-critical point, whose universal exponents for large enough N (here up to N=12) approach the values obtained in a 1/N expansion of the noncompact CP(N-1) field theory. These results lend strong support to the deconfined quantum-criticality theory of the Néel-valence-bond-solid transition.

  6. Large entropy change accompanying two successive magnetic phase transitions in TbMn{sub 2}Si{sub 2} for magnetic refrigeration

    SciTech Connect

    Li, Guoxing; Cheng, Zhenxiang E-mail: cheng@uow.edu.au; Fang, Chunsheng; Dou, Shixue; Wang, Jianli E-mail: cheng@uow.edu.au; Ren, Qingyong

    2015-05-04

    Structural and magnetic properties in TbMn{sub 2}Si{sub 2} are studied by variable temperature X-ray diffraction, magnetization, electrical resistivity, and heat capacity measurements. TbMn{sub 2}Si{sub 2} undergoes two successive magnetic transitions at around T{sub c1} = 50 K and T{sub c2} = 64 K. T{sub c1} remains almost constant with increasing magnetic field, but T{sub c2} shifts significantly to higher temperature. Thus, there are two partially overlapping peaks in the temperature dependence of magnetic entropy change, i.e., −ΔS{sub M} (T). The different responses of T{sub c1} and T{sub c2} to external magnetic field, and the overlapping of −ΔS{sub M} (T) around T{sub c1} and T{sub c2} induce a large refrigerant capacity (RC) within a large temperature range. The large reversible magnetocaloric effect (−ΔS{sub M}{sup peak} ∼ 16 J/kg K for a field change of 0–5 T) and RC (=396 J/kg) indicate that TbMn{sub 2}Si{sub 2} could be a promising candidate for low temperature magnetic refrigeration.

  7. An ensemble average method to estimate absolute TEC using radio beacon-based differential phase measurements: Applicability to regions of large latitudinal gradients in plasma density

    NASA Astrophysics Data System (ADS)

    Thampi, Smitha V.; Bagiya, Mala S.; Chakrabarty, D.; Acharya, Y. B.; Yamamoto, M.

    2014-12-01

    A GNU Radio Beacon Receiver (GRBR) system for total electron content (TEC) measurements using 150 and 400 MHz transmissions from Low-Earth Orbiting Satellites (LEOS) is fabricated in house and made operational at Ahmedabad (23.04°N, 72.54°E geographic, dip latitude 17°N) since May 2013. This system receives the 150 and 400 MHz transmissions from high-inclination LEOS. The first few days of observations are presented in this work to bring out the efficacy of an ensemble average method to convert the relative TECs to absolute TECs. This method is a modified version of the differential Doppler-based method proposed by de Mendonca (1962) and suitable even for ionospheric regions with large spatial gradients. Comparison of TECs derived from a collocated GPS receiver shows that the absolute TECs estimated by this method are reliable estimates over regions with large spatial gradient. This method is useful even when only one receiving station is available. The differences between these observations are discussed to bring out the importance of the spatial differences between the ionospheric pierce points of these satellites. A few examples of the latitudinal variation of TEC during different local times using GRBR measurements are also presented, which demonstrates the potential of radio beacon measurements in capturing the large-scale plasma transport processes in the low-latitude ionosphere.

  8. Lars Onsager Prize: Optimization and learning algorithms from the theory of disordered systems

    NASA Astrophysics Data System (ADS)

    Zecchina, Riccardo

    The extraction of information from large amounts of data is one of the prominent cross disciplinary challenges in contemporary science. Solving inverse and learning problems over large scale data sets requires the design of efficient optimization algorithms over very large scale networks of constraints. In such a setting, critical phenomena of the type studied in statistical physics of disordered systems often play a crucial role. This observation has lead in the last decade to a cross fertilization between statistical physics, information theory and computer science, with applications in a variety of fields. In particular a deeper geometrical understanding of the ground state structure of random computational problems and novel classes of probabilistic algorithms have emerged. In this talk I will give a brief overview of these conceptual advances and I will discuss the role that subdominant states play in the design of algorithms for large scale optimization problems. I will conclude by showing how these ideas can lead to novel applications in computational neuroscience.

  9. Image correction during large and rapid B(0) variations in an open MRI system with permanent magnets using navigator echoes and phase compensation.

    PubMed

    Li, Jianqi; Wang, Yi; Jiang, Yu; Xie, Haibin; Li, Gengying

    2009-09-01

    An open permanent magnet system with vertical B(0) field and without self-shielding can be quite susceptible to perturbations from external magnetic sources. B(0) variation in such a system located close to a subway station was measured to be greater than 0.7 microT by both MRI and a fluxgate magnetometer. This B(0) variation caused image artifacts. A navigator echo approach that monitored and compensated the view-to-view variation in magnetic resonance signal phase was developed to correct for image artifacts. Human brain imaging experiments using a multislice gradient-echo sequence demonstrated that the ghosting and blurring artifacts associated with B(0) variations were effectively removed using the navigator method.

  10. Development of a ReaxFF potential for carbon condensed phases and its application to the thermal fragmentation of a large fullerene

    SciTech Connect

    Srinivasan, Sriram Goverapet; Adri C. T. van Duin; Ganesh, Panchapakesan

    2015-01-06

    In this paper, we report the development of a ReaxFF reactive potential that can accurately describe the chemistry and dynamics of carbon condensed phases. Density functional theory (DFT)-based calculations were performed to obtain the equation of state for graphite and diamond and the formation energies of defects in graphene and amorphous phases from fullerenes. The DFT data were used to reparametrize ReaxFFCHO, resulting in a new potential called ReaxFFC-2013. ReaxFFC-2013 accurately predicts the atomization energy of graphite and closely reproduces the DFT-based energy difference between graphite and diamond, and the barrier for transition from graphite to diamond. ReaxFFC-2013 also accurately predicts the DFT-based energy barrier for Stone–Wales transformation in a C60(Ih) fullerene through the concerted rotation of a C2 unit. Later, MD simulations of a C180 fullerene using ReaxFFC-2013 suggested that the thermal fragmentation of these giant fullerenes is an exponential function of time. An Arrhenius-type equation was fit to the decay rate, giving an activation energy of 7.66 eV for the loss of carbon atoms from the fullerene. Although the decay of the molecule occurs primarily via the loss of C2 units, we observed that, with an increase in temperature, the probability of loss of larger fragments increases. Finally, the ReaxFFC-2013 potential developed in this work, and the results obtained on fullerene fragmentation, provide an important step toward the full computational chemical modeling of coal pyrolysis, soot incandescence, high temperature erosion of graphitic rocket nozzles, and ablation of carbon-based spacecraft materials during atmospheric reentry.

  11. Development of a ReaxFF potential for carbon condensed phases and its application to the thermal fragmentation of a large fullerene

    DOE PAGES

    Srinivasan, Sriram Goverapet; Adri C. T. van Duin; Ganesh, Panchapakesan

    2015-01-06

    In this paper, we report the development of a ReaxFF reactive potential that can accurately describe the chemistry and dynamics of carbon condensed phases. Density functional theory (DFT)-based calculations were performed to obtain the equation of state for graphite and diamond and the formation energies of defects in graphene and amorphous phases from fullerenes. The DFT data were used to reparametrize ReaxFFCHO, resulting in a new potential called ReaxFFC-2013. ReaxFFC-2013 accurately predicts the atomization energy of graphite and closely reproduces the DFT-based energy difference between graphite and diamond, and the barrier for transition from graphite to diamond. ReaxFFC-2013 also accuratelymore » predicts the DFT-based energy barrier for Stone–Wales transformation in a C60(Ih) fullerene through the concerted rotation of a C2 unit. Later, MD simulations of a C180 fullerene using ReaxFFC-2013 suggested that the thermal fragmentation of these giant fullerenes is an exponential function of time. An Arrhenius-type equation was fit to the decay rate, giving an activation energy of 7.66 eV for the loss of carbon atoms from the fullerene. Although the decay of the molecule occurs primarily via the loss of C2 units, we observed that, with an increase in temperature, the probability of loss of larger fragments increases. Finally, the ReaxFFC-2013 potential developed in this work, and the results obtained on fullerene fragmentation, provide an important step toward the full computational chemical modeling of coal pyrolysis, soot incandescence, high temperature erosion of graphitic rocket nozzles, and ablation of carbon-based spacecraft materials during atmospheric reentry.« less

  12. Development of a ReaxFF potential for carbon condensed phases and its application to the thermal fragmentation of a large fullerene.

    PubMed

    Srinivasan, Sriram Goverapet; van Duin, Adri C T; Ganesh, P

    2015-01-29

    In this article, we report the development of a ReaxFF reactive potential that can accurately describe the chemistry and dynamics of carbon condensed phases. Density functional theory (DFT)-based calculations were performed to obtain the equation of state for graphite and diamond and the formation energies of defects in graphene and amorphous phases from fullerenes. The DFT data were used to reparametrize ReaxFFCHO, resulting in a new potential called ReaxFFC-2013. ReaxFFC-2013 accurately predicts the atomization energy of graphite and closely reproduces the DFT-based energy difference between graphite and diamond, and the barrier for transition from graphite to diamond. ReaxFFC-2013 also accurately predicts the DFT-based energy barrier for Stone-Wales transformation in a C60(Ih) fullerene through the concerted rotation of a C2 unit. Later, MD simulations of a C180 fullerene using ReaxFFC-2013 suggested that the thermal fragmentation of these giant fullerenes is an exponential function of time. An Arrhenius-type equation was fit to the decay rate, giving an activation energy of 7.66 eV for the loss of carbon atoms from the fullerene. Although the decay of the molecule occurs primarily via the loss of C2 units, we observed that, with an increase in temperature, the probability of loss of larger fragments increases. The ReaxFFC-2013 potential developed in this work, and the results obtained on fullerene fragmentation, provide an important step toward the full computational chemical modeling of coal pyrolysis, soot incandescence, high temperature erosion of graphitic rocket nozzles, and ablation of carbon-based spacecraft materials during atmospheric reentry.

  13. A phase II study of dacetuzumab (SGN-40) in patients with relapsed diffuse large B-cell lymphoma (DLBCL) and correlative analyses of patient-specific factors

    PubMed Central

    2014-01-01

    Background Patients with DLBCL who are ineligible for or have relapsed after aggressive salvage chemotherapy have a poor prognosis. CD40 is expressed on multiple B-cell neoplasms including DLBCL and is a potential target for immunotherapy. Dacetuzumab (SGN-40), a non-blocking, partial agonist, humanized IgG1, anti-CD40 monoclonal antibody, has previously demonstrated anti-lymphoma activity in a phase I study. Methods A phase II study was undertaken to evaluate the rate and duration of objective responses and safety of single-agent dacetuzumab in relapsed DLBCL. Forty-six adult patients with relapsed/refractory DLBCL received up to 12 cycles of intravenous dacetuzumab using intrapatient dose-escalation to a target dose of 8 mg/kg/week in an initial 5-week cycle, followed by 4-week cycles of 8 mg/kg/week. Study endpoints included rate and duration of objective responses, safety, survival, pharmacokinetics, immunogenicity, and exploratory correlative studies. Results Overall response rate was 9% and disease control rate (complete remission + partial remission + stable disease) was 37%. Common non-hematologic adverse events (AEs) included fatigue, headache, chills, fever, and nausea. The most frequent Grade 3–4 non-hematologic AE was deep venous thrombosis (3 patients). Grade 3–4 lymphopenia (41%), neutropenia (13%), or thrombocytopenia (19%) occurred without associated infection or bleeding. Reversible ocular events, including conjunctivitis and ocular hyperemia, occurred in 8 patients (17%). Patient-specific factors, including Fc-gamma-RIIIa polymorphism, did not appear to correlate with antitumor activity. Conclusions Single-agent dacetuzumab has modest activity and manageable toxicity in unselected patients with relapsed DLBCL. Combination regimens and robust methods of patient selection may be necessary for further development. Trial registration ClinicalTrials.gov identifier NCT00435916. PMID:24919462

  14. Determination of the bias in LOFT fuel peak cladding temperature data from the blowdown phase of large-break LOCA experiments

    SciTech Connect

    Berta, V.T.; Hanson, R.G.; Johnsen, G.W.; Schultz, R.R.

    1993-05-01

    Data from the Loss-of-Fluid Test (LOFT) Program help quantify the margin of safety inherent in pressurized water reactors during postulated loss-of-coolant accidents (LOCAs). As early as 1979, questions arose concerning the accuracy of LOFT fuel rod cladding temperature data during several large-break LOCA experiments. This report analyzes how well externally-mounted fuel rod cladding thermocouples in LOFT accurately reflected actual cladding surface temperature during large-break LOCA experiments. In particular, the validity of the apparent core-wide fuel rod cladding quench exhibited during blowdown in LOFT Experiments L2-2 and L2-3 is studied. Also addressed is the question of whether the externally-mounted thermocouples might have influenced cladding temperature. The analysis makes use of data and information from several sources, including later, similar LOFT Experiments in which fuel centerline temperature measurements were made, experiments in other facilities, and results from a detailed FRAP-T6 model of the LOFT fuel rod. The analysis shows that there can be a significant difference (referred to as bias) between the surface-mounted thermocouple reading and the actual cladding temperature, and that the magnitude of this bias depends on the rate of heat transfer between the fuel rod cladding and coolant. The results of the analysis demonstrate clearly that a core-wide cladding quench did occur in Experiments L2-2 and L2-3. Further, it is shown that, in terms of peak cladding temperature recording during LOFT large-break LOCA experiments, the mean bias is 11.4 {plus_minus} 16.2K (20.5 {plus_minus} 29.2{degrees} F). The best-estimate value of peak cladding temperature for LOFT LP-02-6 is 1,104.8 K. The best-estimate peak cladding temperature for LOFT LP-LB-1 is 1284.0 K.

  15. Stiffening effect of cholesterol on disordered lipid phases: a combined neutron spin echo + dynamic light scattering analysis of the bending elasticity of large unilamellar vesicles.

    PubMed

    Arriaga, Laura R; López-Montero, Iván; Monroy, Francisco; Orts-Gil, Guillermo; Farago, Bela; Hellweg, Thomas

    2009-05-06

    In this study, the center-of-mass diffusion and shape fluctuations of large unilamellar 1-palmitoyl-2-oleyl-sn-glycero-phosphatidylcholine vesicles prepared by extrusion are studied by means of neutron spin echo in combination with dynamic light scattering. The intermediate scattering functions were measured for several different values of the momentum transfer, q, and for different cholesterol contents in the membrane. The combined analysis of neutron spin echo and dynamic light scattering data allows calculation of the bending elastic constant, kappa, of the vesicle bilayer. A stiffening effect monitored as an increase of kappa with increasing cholesterol molar ratio is demonstrated by these measurements.

  16. First Independent Replication of the Involvement of LARS2 in Perrault Syndrome by Whole-Exome Sequencing of an Italian Family

    PubMed Central

    Soldà, Giulia; Caccia, Sonia; Robusto, Michela; Chiereghin, Chiara; Castorina, Pierangela; Ambrosetti, Umberto; Duga, Stefano; Asselta, Rosanna

    2015-01-01

    Perrault syndrome (MIM #233400) is a rare autosomal recessive disorder characterized by ovarian dysgenesis and primary ovarian insufficiency in females, and progressive hearing loss in both genders. Recently, mutations in five genes (HSD17B4, HARS2, CLPP, LARS2, and C10ORF2) were found to be responsible for Perrault syndrome, although they do not account for all cases of this genetically heterogeneous condition. We used whole-exome sequencing to identify pathogenic variants responsible for Perrault syndrome in an Italian pedigree with two affected siblings. Both patients were compound heterozygous for two novel missense variants within the mitochondrial leucyl-tRNA synthetase (LARS2), NM_015340.3:c.899C>T(p.Thr300Met) and c.1912G>A(p.Glu638Lys). Both variants co-segregated with the phenotype in the family. p.Thr300 and p.Glu638 are evolutionary conserved residues, and are located respectively within the editing domain and immediately before the catalytically important KMSKS motif. Homology modeling using as template the E. coli leucyl-tRNA synthetase provided further insights on the possible pathogenic effects of the identified variants. This represents the first independent replication of the involvement of LARS2 mutations in Perrault syndrome, contributing valuable information for the further understanding of this disease. PMID:26657938

  17. PoLAR Voices: Informing Adult Learners about the Science and Story of Climate Change in the Polar Regions Through Audio Podcast

    NASA Astrophysics Data System (ADS)

    Quinney, A.; Murray, M. S.; Gobroski, K. A.; Topp, R. M.; Pfirman, S. L.

    2015-12-01

    The resurgence of audio programming with the advent of podcasting in the early 2000s spawned a new medium for communicating advances in science, research, and technology. To capitalize on this informal educational outlet, the Arctic Institute of North America partnered with the International Arctic Research Center, the University of Alaska Fairbanks, and the UA Museum of the North to develop a podcast series called PoLAR Voices for the Polar Learning and Responding (PoLAR) Climate Change Education Partnership. PoLAR Voices is a public education initiative that uses creative storytelling and novel narrative structures to immerse the listener in an auditory depiction of climate change. The programs will feature the science and story of climate change, approaching topics from both the points of view of researchers and Arctic indigenous peoples. This approach will engage the listener in the holistic story of climate change, addressing both scientific and personal perspectives, resulting in a program that is at once educational, entertaining and accessible. Feedback is being collected at each stage of development to ensure the content and format of the program satisfies listener interests and preferences. Once complete, the series will be released on thepolarhub.org and on iTunes. Additionally, blanket distribution of the programs will be accomplished via radio broadcast in urban, rural and remote areas, and in multiple languages to increase distribution and enhance accessibility.

  18. Large Scale Solid Phase Synthesis of Peptide Drugs: Use of Commercial Anion Exchange Resin as Quenching Agent for Removal of Iodine during Disulphide Bond Formation.

    PubMed

    Reddy, K M Bhaskara; Kumari, Y Bharathi; Mallikharjunasarma, Dokka; Bulliraju, Kamana; Sreelatha, Vanjivaka; Ananda, Kuppanna

    2012-01-01

    The S-acetamidomethyl (Acm) or trityl (Trt) protecting groups are widely used in the chemical synthesis of peptides that contain one or more disulfide bonds. Treatment of peptides containing S-Acm protecting group with iodine results in simultaneous removal of the sulfhydryl protecting group and disulfide formation. However, the excess iodine needs to be quenched or adsorbed as quickly as possible after completion of the disulfide bond formation in order to minimize side reactions that are often associated with the iodination step. We report here a simple method for simultaneous quenching and removal of iodine and isolation of disulphide bridge peptides. The use of excess inexpensive anion exchange resin to the oxidized peptide from the aqueous acetic acid/methanol solution affords quantitative removal of iodine and other color impurities. This improves the resin life time of expensive chromatography media that is used in preparative HPLC column during the purification of peptide using preparative HPLC. Further, it is very useful for the conversion of TFA salt to acetate in situ. It was successfully applied commercially, to the large scale synthesis of various peptides including Desmopressin, Oxytocin, and Octreotide. This new approach offers significant advantages such as more simple utility, minimal side reactions, large scale synthesis of peptide drugs, and greater cost effectiveness.

  19. Large low field magnetocaloric effect in first-order phase transition compound TlFe3Te3 with low-level hysteresis

    PubMed Central

    Mao, Qianhui; Yang, Jinhu; Wang, Hangdong; Khan, Rajwali; Du, Jianhua; Zhou, Yuxing; Xu, Binjie; Chen, Qin; Fang, Minghu

    2016-01-01

    Magnetic refrigeration based on the magnetocaloric effect (MCE) is an environment-friendly, high-efficiency technology. It has been believed that a large MCE can be realized in the materials with a first-order magnetic transition (FOMT). Here, we found that TlFe3Te3 is a ferromagnetic metal with a first-order magnetic transition occurring at Curie temperature TC = 220 K. The maximum values of magnetic entropy change (Δ) along the crystallographic c-axis, estimated from the magnetization data, reach to 5.9 J kg−1K−1 and 7.0 J kg−1 K−1 for the magnetic field changes, ΔH = 0–1 T and 0–2 T, respectively, which is significantly larger than that of MCE materials with a second-order magnetic transition (SOMT). Besides the large ΔSM, the low-level both thermal and field hysteresis make TlFe3Te3 compound an attractive candidate for magnetic refrigeration. Our findings should inspire the exploration of high performance new MCE materials. PMID:27681203

  20. Large Scale Solid Phase Synthesis of Peptide Drugs: Use of Commercial Anion Exchange Resin as Quenching Agent for Removal of Iodine during Disulphide Bond Formation

    PubMed Central

    Reddy, K. M. Bhaskara; Kumari, Y. Bharathi; Mallikharjunasarma, Dokka; Bulliraju, Kamana; Sreelatha, Vanjivaka; Ananda, Kuppanna

    2012-01-01

    The S-acetamidomethyl (Acm) or trityl (Trt) protecting groups are widely used in the chemical synthesis of peptides that contain one or more disulfide bonds. Treatment of peptides containing S-Acm protecting group with iodine results in simultaneous removal of the sulfhydryl protecting group and disulfide formation. However, the excess iodine needs to be quenched or adsorbed as quickly as possible after completion of the disulfide bond formation in order to minimize side reactions that are often associated with the iodination step. We report here a simple method for simultaneous quenching and removal of iodine and isolation of disulphide bridge peptides. The use of excess inexpensive anion exchange resin to the oxidized peptide from the aqueous acetic acid/methanol solution affords quantitative removal of iodine and other color impurities. This improves the resin life time of expensive chromatography media that is used in preparative HPLC column during the purification of peptide using preparative HPLC. Further, it is very useful for the conversion of TFA salt to acetate in situ. It was successfully applied commercially, to the large scale synthesis of various peptides including Desmopressin, Oxytocin, and Octreotide. This new approach offers significant advantages such as more simple utility, minimal side reactions, large scale synthesis of peptide drugs, and greater cost effectiveness. PMID:23118772

  1. Large low field magnetocaloric effect in first-order phase transition compound TlFe3Te3 with low-level hysteresis.

    PubMed

    Mao, Qianhui; Yang, Jinhu; Wang, Hangdong; Khan, Rajwali; Du, Jianhua; Zhou, Yuxing; Xu, Binjie; Chen, Qin; Fang, Minghu

    2016-09-29

    Magnetic refrigeration based on the magnetocaloric effect (MCE) is an environment-friendly, high-efficiency technology. It has been believed that a large MCE can be realized in the materials with a first-order magnetic transition (FOMT). Here, we found that TlFe3Te3 is a ferromagnetic metal with a first-order magnetic transition occurring at Curie temperature TC = 220 K. The maximum values of magnetic entropy change (Δ) along the crystallographic c-axis, estimated from the magnetization data, reach to 5.9 J kg(-1)K(-1) and 7.0 J kg(-1) K(-1) for the magnetic field changes, ΔH = 0-1 T and 0-2 T, respectively, which is significantly larger than that of MCE materials with a second-order magnetic transition (SOMT). Besides the large ΔSM, the low-level both thermal and field hysteresis make TlFe3Te3 compound an attractive candidate for magnetic refrigeration. Our findings should inspire the exploration of high performance new MCE materials.

  2. Large low field magnetocaloric effect in first-order phase transition compound TlFe3Te3 with low-level hysteresis

    NASA Astrophysics Data System (ADS)

    Mao, Qianhui; Yang, Jinhu; Wang, Hangdong; Khan, Rajwali; Du, Jianhua; Zhou, Yuxing; Xu, Binjie; Chen, Qin; Fang, Minghu

    2016-09-01

    Magnetic refrigeration based on the magnetocaloric effect (MCE) is an environment-friendly, high-efficiency technology. It has been believed that a large MCE can be realized in the materials with a first-order magnetic transition (FOMT). Here, we found that TlFe3Te3 is a ferromagnetic metal with a first-order magnetic transition occurring at Curie temperature TC = 220 K. The maximum values of magnetic entropy change (Δ) along the crystallographic c-axis, estimated from the magnetization data, reach to 5.9 J kg‑1K‑1 and 7.0 J kg‑1 K‑1 for the magnetic field changes, ΔH = 0–1 T and 0–2 T, respectively, which is significantly larger than that of MCE materials with a second-order magnetic transition (SOMT). Besides the large ΔSM, the low-level both thermal and field hysteresis make TlFe3Te3 compound an attractive candidate for magnetic refrigeration. Our findings should inspire the exploration of high performance new MCE materials.

  3. Role of Dynamic Magnetic Resonance Imaging in the Evaluation of Tumor Response to Preoperative Concurrent Radiochemotherapy for Large Breast Cancers: A Prospective Phase II Study

    SciTech Connect

    Bollet, Marc A. Thibault, Fabienne; Bouillon, Kim; Meunier, Martine; Sigal-Zafrani, Brigitte; Savignoni, Alexia; Dieras, Veronique; Nos, Claude; Salmon, Remy; Fourquet, Alain

    2007-09-01

    Purpose: To evaluate the accuracy of clinical examination and of three imaging modalities (ultrasound [US] scan, mammography, and magnetic resonance imaging [MRI]) to assess the tumor response of breast cancer to a preoperative regimen of concurrent radiochemotherapy for large breast cancers, using pathologic data as the reference. Methods and Materials: Sixty women were accrued. Treatment consisted of 4 cycles of (5-fluorouracil-vinorelbine) chemotherapy with, starting with the second cycle of chemotherapy, locoregional radiotherapy to the breast and the internal mammary and supraclavicular and infraclavicular lymph nodes. Breast surgery and axillary lymph node dissection were subsequently performed. Breast imaging assessments were performed both before chemotherapy and preoperatively. Results: The correlation coefficients between tumor dimension at imaging and pathology were statistically significant for US scan (r = 0.4; p = 0.006) and MRI (r = 0.4; p = 0.004) but not for clinical examination (r 0.2; p = 0.16) or mammography (r = -0.15; p = 0.31). Furthermore, the area under the receiver operating characteristic curve for MRI was 0.81, compared with 0.67 for US scan. At the optimal threshold score, MRI performed with 81% sensitivity and 75% specificity. Conclusion: Compared with clinical examination, US scan, or mammography, MRI substantially improved the prediction of pathologic tumor response to preoperative concurrent radiochemotherapy for large breast cancers.

  4. Analysis of Spatial-Temporal Variation of Land Surface Temperature, Vegetation and Snow Cover in Lar National Park of Iran

    NASA Astrophysics Data System (ADS)

    Arekhi, M.

    2016-10-01

    Changes in land surface reflectance measured by remote sensing data can be useful in climate change studies. This study attempts to analyze the spatial-temporal extent change of vegetation greenness, Land Surface Temperature (LST), and Normalized Difference Snow Index (NDSI) in late spring at the Lar National Park of Iran using Landsat data. Vegetation indices (VIs), LST, and NDSI maps were calculated for each date (1985, 1994, 2010, and 2015). All VIs have shown an increasing trend from 1985 to 2015 which depicted increase of vegetation. Spectral reflectance of all bands is declining from 1985 to 2015 except in near-infrared (NIR) bands. High reflectance in NIR bands is due to increased vegetation greenness. The reduction was seen in the visible bands that show increased vegetation photosynthetic activity. In the short-wave infrared bands (SWIR) were observed reduced trend from 1985 to 2015 which is indicate increased vegetation. Also, in the mid-wave infrared (MWIR) bands were observed a declining trend which is the result of decreasing soil fraction from 1985 to 2015. LST has increased from 23.27 °C in 1985 to 27.45 °C in 2015. Snow patches were decreased over the study period. In conclusion, VIs and surface reflectance bands are considered the main tool to display vegetation change. Also, high VIs values showed healthy and dense vegetation. The results of our study will provide valuable information in preliminary climate change studies.

  5. Effects of social status and stress on patterns of gastrointestinal parasitism in wild white-handed gibbons (Hylobates lar).

    PubMed

    Gillespie, Thomas R; Barelli, Claudia; Heistermann, Michael

    2013-04-01

    Although gibbons (family Hylobatidae) are typically monogamous, polyandrous groups occur regularly. Stress associated with elevated intragroup competition among males in polyandrous groups may increase susceptibility to infectious disease. To better understand this interplay, as well as to provide the first comprehensive assessment of parasitism in free-ranging gibbons, we characterized the richness of gastrointestinal parasites and examined their prevalence in males from 14 groups (10 pair-living, 4 multi-male) of white-handed gibbons (Hylobates lar) at Khao Yai National Park, Thailand. From September 2008 to May 2009, 324 fecal samples were collected from 23 individually recognizable male gibbons and screened for gastrointestinal helminths and protozoa after isolation via fecal floatation, sedimentation, and immunofluorescent antibody detection. A total of 10 parasite species recovered, including seven nematodes, two protozoans, and one trematode. Parasite richness and species-specific prevalence were examined relative to social organization (pair-living vs. multi-male), male status (primary vs. secondary), age (subadult, adult, senior), fecal glucocorticoid levels, and time of the year. No relationship was found between parasite richness and sociodemographic or physiological factors. Similarly, prevalence of infection with parasite species was not associated with the majority of sociodemographic factors; however, Ternidens sp. and Balantidium coli varied seasonally and Trichuris sp. decreased with increasing age. Moreover, observational data suggest that competition is low in this gibbon population, and our findings are consistent with those observations in that cooperative defense may offset stress and reduce susceptibility to infection.

  6. Brief communication: Three-dimensional motion analysis of hindlimb during brachiation in a white-handed gibbon (Hylobates lar).

    PubMed

    Oka, Kenji; Hirasaki, Eishi; Hirokawa, Yohko; Nakano, Yoshihiko; Kumakura, Hiroo

    2010-08-01

    In brachiating gibbons, it is thought that there is little movement in the hindlimb joints and that lateral body movement is quite limited. These hypotheses are based on naked-eye observations, and no quantitative motion analyses of the hindlimbs have been reported. This study quantitatively describes the three-dimensional movements of the lower trunk and distal thigh during continuous-contact brachiation in a white-handed gibbon (Hylobates lar) to evaluate the roles of the trunk and hindlimb. The results revealed that the lower trunk moved both laterally and vertically. The lateral movement of the lower trunk resulted from the lateral inclination of the trunk by gravity. The vertical movement of the trunk was converted into forward velocity, indicating an exchange between potential and kinetic energy. We also observed flexion and extension of the hip, although the excursion was within a small range. In addition, the lateral movement of the hindlimb in thedirection opposite to that of trunk movement helped to reduce the lateral sway of the body. These results suggest that during continuous-contact brachiation a gibbon uses hip flexion and extension motions to increase the kinetic energy in the swing. In addition, fine motions of the hip may restrict the lateral sway of the center of body mass.

  7. FIRST RESULTS FROM VERY LARGE TELESCOPE NACO APODIZING PHASE PLATE: 4 {mu}m IMAGES OF THE EXOPLANET {beta} PICTORIS b

    SciTech Connect

    Quanz, Sascha P.; Meyer, Michael R.; Kenworthy, Matthew A.; Girard, Julien H. V.; Kasper, Markus; Lagrange, Anne-Marie; Bonnefoy, Mickael; Chauvin, Gael; Apai, Daniel; Boccaletti, Anthony; Hinz, Philip M.; Lenzen, Rainer

    2010-10-10

    Direct imaging of exoplanets requires both high contrast and high spatial resolution. Here, we present the first scientific results obtained with the newly commissioned apodizing phase plate coronagraph (APP) on VLT/NACO. We detected the exoplanet {beta} Pictoris b in the narrowband filter centered at 4.05 {mu}m (NB4.05). The position angle (209.{sup 0}13 {+-} 2.{sup 0}12) and the projected separation to its host star (0.''354 {+-} 0.''012, i.e., 6.8 {+-} 0.2 AU at a distance of 19.3 pc) are in good agreement with the recently presented data from Lagrange et al. Comparing the observed NB4.05 magnitude of 11.20 {+-} 0.23 mag to theoretical atmospheric models, we find a best fit with a 7-10 M {sub Jupiter} object for an age of 12 Myr, again in agreement with previous estimates. Combining our results with published L' photometry, we can compare the planet's [L' - NB4.05] color to that of cool field dwarfs of higher surface gravity suggesting an effective temperature of {approx}1700 K. The best-fit theoretical model predicts an effective temperature of {approx}1470 K, but this difference is not significant given our photometric uncertainties. Our results demonstrate the potential of NACO/APP for future planet searches and provide independent confirmation as well as complementary data for {beta} Pic b.

  8. ASSESSING THE IMPACT OF SAFETY MONITORING ON THE EFFICACY ANALYSIS IN LARGE PHASE III GROUP SEQUENTIAL TRIALS WITH NON-TRIVIAL SAFETY EVENT RATE

    PubMed Central

    Weng, Yanqiu; Palesch, Yuko Y.; DeSantis, Stacia M.; Zhao, Wenle

    2015-01-01

    In Phase III clinical trials for life-threatening conditions, some serious but expected adverse events, such as early deaths or congestive heart failure, are often treated as the secondary or co-primary endpoint, and are closely monitored by the data and safety monitoring committee. A naïve group sequential design for such a study is to specify univariate statistical boundaries for the efficacy and safety endpoints separately, and then implement the two boundaries during the study, even though the two endpoints are typically correlated. One problem with this naïve design, which has been noted in the statistical literature, is the potential loss of power. In this paper, we develop an analytical tool to evaluate this negative impact for trials with non-trivial safety event rates, particularly when the safety monitoring is informal. Using a bivariate binary power function for the group sequential design with a random effect component to account for subjective decision making in safety monitoring, we demonstrate how, under common conditions, the power loss in the naïve design can be substantial. This tool may be helpful to entities such as the data and safety monitoring committees when they wish to deviate from the pre-specified stopping boundaries based on safety measures. PMID:26010228

  9. Comparison of large scale purification processes of naproxen enantiomers by chromatography using methanol-water and methanol-supercritical carbon dioxide mobile phases.

    PubMed

    Kamarei, Fahimeh; Vajda, Péter; Guiochon, Georges

    2013-09-20

    This paper compares two methods used for the preparative purification of a mixture of (S)-, and (R)-naproxen on a Whelk-O1 column, using either high performance liquid chromatography or supercritical fluid chromatography. The adsorption properties of both enantiomers were measured by frontal analysis, using methanol-water and methanol-supercritical carbon dioxide mixtures as the mobile phases. The measured adsorption data were modeled, providing the adsorption isotherms and their parameters, which were derived from the nonlinear fit of the isotherm models to the experimental data points. The model used was a Bi-Langmuir isotherm, similar to the model used in many enantiomeric separations. These isotherms were used to calculate the elution profiles of overloaded elution bands, assuming competitive Bi-Langmuir behavior of the two enantiomers. The analysis of these profiles provides the basis for a comparison between supercritical fluid chromatographic and high performance liquid chromatographic preparative scale separations. It permits an illustration of the advantages and disadvantages of these methods and a discussion of their potential performance.

  10. Locality and rapidity of the ultra-large elastic deformation of Nb nanowires in a NiTi phase-transforming matrix.

    PubMed

    Wang, Shan; Cui, Lishan; Hao, Shijie; Jiang, Daqiang; Liu, Yinong; Liu, Zhenyang; Mao, Shengcheng; Han, Xiaodong; Ren, Yang

    2014-10-24

    This study investigated the elastic deformation behaviour of Nb nanowires embedded in a NiTi matrix. The Nb nanowires exhibited an ultra-large elastic deformation, which is found to be dictated by the martensitic transformation of the NiTi matrix, thus exhibiting unique characteristics of locality and rapidity. These are in clear contrast to our conventional observation of elastic deformations of crystalline solids, which is a homogeneous lattice distortion with a strain rate controlled by the applied strain. The Nb nanowires are also found to exhibit elastic-plastic deformation accompanying the martensitic transformation of the NiTi matrix in the case when the transformation strain of the matrix over-matches the elastic strain limit of the nanowires, or exhibit only elastic deformation in the case of under-matching. Such insight provides an important opportunity for elastic strain engineering and composite design.

  11. Evaluation of the conservation potential of a refit energy management system (using a power line subcarrier) in a large, high-rise apartment complex. Phase II

    SciTech Connect

    Hirschfeld, H.E.

    1981-09-01

    An energy conservation study of the application of an energy management system (EMS) utilizing power line subcarrier communication equipment was made in a large apartment building in New York, New York. The building utilized individual cooling and resistance heating units in each apartment. The EMS turned the individual units on and off (with override by tenants) on a schedule determined by the building operator. Summer savings were found to be 11%; winter savings were 20%. Annual savings were projected to be 19%. The study demonstrated the conservation value of power line subcarrier technology as an alternative to submetering. It also developed and evaluated control strategies for the system and served as a field test to accelerate commercialization of the technology.

  12. Locality and rapidity of the ultra-large elastic deformation of Nb nanowires in a NiTi phase-transforming matrix

    DOE PAGES

    Wang, Shan; Cui, Lishan; Hao, Shijie; ...

    2014-10-24

    This study investigated the elastic deformation behaviour of Nb nanowires embedded in a NiTi matrix. The Nb nanowires exhibited an ultra-large elastic deformation, which is found to be dictated by the martensitic transformation of the NiTi matrix, thus exhibiting unique characteristics of locality and rapidity. These are in clear contrast to our conventional observation of elastic deformations of crystalline solids, which is a homogeneous lattice distortion with a strain rate controlled by the applied strain. The Nb nanowires are also found to exhibit elastic-plastic deformation accompanying the martensitic transformation of the NiTi matrix in the case when the transformation strainmore » of the matrix over-matches the elastic strain limit of the nanowires, or exhibit only elastic deformation in the case of under-matching. Such insight provides an important opportunity for elastic strain engineering and composite design.« less

  13. Locality and rapidity of the ultra-large elastic deformation of Nb nanowires in a NiTi phase-transforming matrix

    SciTech Connect

    Wang, Shan; Cui, Lishan; Hao, Shijie; Jiang, Daqiang; Liu, Yinong; Liu, Zhenyang; Mao, Shengcheng; Han, Xiaodong; Ren, Yang

    2014-10-24

    This study investigated the elastic deformation behaviour of Nb nanowires embedded in a NiTi matrix. The Nb nanowires exhibited an ultra-large elastic deformation, which is found to be dictated by the martensitic transformation of the NiTi matrix, thus exhibiting unique characteristics of locality and rapidity. These are in clear contrast to our conventional observation of elastic deformations of crystalline solids, which is a homogeneous lattice distortion with a strain rate controlled by the applied strain. The Nb nanowires are also found to exhibit elastic-plastic deformation accompanying the martensitic transformation of the NiTi matrix in the case when the transformation strain of the matrix over-matches the elastic strain limit of the nanowires, or exhibit only elastic deformation in the case of under-matching. Such insight provides an important opportunity for elastic strain engineering and composite design.

  14. New approach to large-volume injection in reversed-phase high performance liquid chromatography: determination of atrazine and hydroxyatrazine in soil samples.

    PubMed

    Hutta, Milan; Chalányová, Mária; Halko, Radoslav; Góra, Róbert; Rybár, Ivan; Pajchl, Marek; Dokupilová, Svetlana

    2006-08-01

    A well established method of direct injection of larger than conventional sample volumes ranging from 0.1 mL to 10 mL in HPLC is the injection valve method in which a loop of tubing is totally or partially filled with sample. Recent HPLC pumps have a flow-rate setting accuracy of +/- 1-2% over a flow-rate range from 0.1 mL/min to 10 mL/min and the flow stability is 0.2% or less. Quarternary low pressure gradient pumps are widely available and used, but all their hydraulic lines are seldom utilised. The idea of using one line of a common commercial HPLC quaternary low-pressure pump for direct on-column injection (pumping) of large sample volumes ranging from 1 mL to 100 mL was tested. This approach was evaluated during practical work on the development of an RP-HPLC method of determination of residual atrazine and hydroxyatrazine. In lysimetric environmental experiments hydroxyatrazine was formed in situ in a soil column by hydrolysis of atrazine. The results proved the applicability of this approach not only in experiments with model mixtures of analytes at microg/L levels in solutions. Analysis of 20 mL of soil leachates and extracts of soil samples containing atrazine and hydroxyatrazine at the 10 microg/kg level (in dry soil) revealed that good figures-of-merit were preserved, even in the presence of a large excess of humic substances.

  15. Palliation of advanced pelvic malignant disease with large fraction pelvic radiation and misonidazole: final report of RTOG phase I/II study

    SciTech Connect

    Spanos, W.J. Jr.; Wasserman, T.; Meoz, R.; Sala, J.; Kong, J.; Stetz, J.

    1987-10-01

    Between October 1979 and June 1982 forty-six patients were entered on a non-randomized Phase I-II protocol for the evaluation of Misonidazole combined with high dose per fraction radiation for the treatment of advanced pelvic malignancies. Pelvic radiation consisted of 1000 cGy in one fraction repeated at 4-week intervals for a total of three treatments. Oral Misonidazole at a dose of 4 gm/m2 was administered 4-6 hr prior to radiation (total dose 12 g/m2). The distribution of histology consisted of 20 gynecologic, 24 bowel, and 2 prostate malignancies. Of the thirty-seven patients completing the three treatments; there were 6 complete responses (14% CR), 10 partial responses (27% PR) 19 minimal or no response (32% NR), and 4 unevaluable. One patient remains NED 5.5 years following radiation. Toxicity directly related to Misonidazole was minimal and consisted primarily of transcient Grade 1, 2 peripheral neuropathy (20% Grade 1, 4% Grade 2) and Grade 2 ototoxicity (4%). Radiation toxicity was significant for late bowel damage. There were 4 (11%) Grade 3 and 7 (19%) Grade 4 gastro-intestinal (GI) toxicities. Kaplan-Meier plot of GI toxicity showed a progressive increase in incidence with time for projected rate of 49% Grade 3, 4 by 12-month. GI toxicity (Grade 3, 4) was also related to tumor response. The complication rate was 80% (4/6) for CR, 30% (3/10) for PR and 26% (5/19) for NR or progression. Because of the GI complication rate, this protocol for palliation of advanced pelvic malignancies has been replaced by a protocol that uses 4 fractions over 2 days (b.i.d.) of 370 cGy per fraction repeated at 3-week intervals for a total of 3 courses.

  16. Large area self-powered gamma ray detector. Phase 2, Development of a source position monitor for use on industrial radiographic units

    SciTech Connect

    LeVert, F.E.

    1994-01-01

    The purpose of this research was to develop a large area self-powered gamma detector (LASPGD) capable of detecting the movement of sealed radiation sources into and out of industrial radiographic units and to construct a prototype source position monitor (SPM) for these units utilizing the LASPGD. Prototype isotropic and directional LASPGDs, with solid and inert gas dielectrics, were developed and extensively tested using calibrated gamma sources (i.e., Cs-137, and Co-60). The sensitivities of the isotropic detectors, with inert gas dielectrics, were found to be approximately a factor of ten greater than those measured for the solid dielectric LASPGDs. Directionally sensitive self-powered detectors were found to exhibit a forward-to-back hemispherical sensitivity ratio of approximately 2 to 1. Industrial radiographic units containing Ir-192 sources with different activities were used to test the performance of the SPM. The SPM, which utilized a gas dielectric LASPGD, performed as designed. That is, the current generated in the LASPGD was converted to a voltage, amplified and used to control the on/off state of an incandescent lamp. The incandescent lamp, which functions as the source/out warning indicator, flashes at a rate of one flash per second when the source is in use (i.e. out of its shield).

  17. Antisite-disorder driven large exchange bias effect in phase separated La1.5Ca0.5CoMnO6 double perovskite

    NASA Astrophysics Data System (ADS)

    Sahoo, R. C.; Paladhi, D.; Dasgupta, Papri; Poddar, A.; Singh, Ripandeep; Das, A.; Nath, T. K.

    2017-04-01

    Investigations of structural and magnetic properties of polycrystalline hole doped double perovskite La1.5Ca0.5CoMnO6 has clearly revealed the existence of structural antisite-disorder (either, Co-O-Co or Mn-O-Mn) in the system. The ordering of Co2+ and Mn4+ gives rise to a ferromagnetic transition around 157 K. A spin-canted antiferromagnetic transition is found in this material at TCAFM 9 K. The effect of antisite-disorder in the double perovskite structure is most likely the prime reason for antiferromagnetic interaction. The temperature dependent inverse susceptibility exhibits Curie-Weiss like behaviour and it yields an effective paramagnetic moment of 6.49 μB. At very low temperature (Tlarge exchange bias (EB) field of HEB 5.5 kOe and can be tuned by the cooling field. The presence of zero-field cooled spontaneous EB effect (P-type and N-type) is confirmed to be not an experimental artefact - an inherent property of this double perovskite material. A phenomenological model has been proposed to explain the exchange coupling between the ferromagnetic and canted-antiferromagnetic interfaces of antisite-disordered La1.5Ca0.5CoMnO6 mainly on the basis of uncompensated interface spins.

  18. On the application of differential phase measurements to study the zonal large scale wave structure (LSWS) in the ionospheric electron content

    NASA Astrophysics Data System (ADS)

    Tulasi Ram, S.; Yamamoto, M.; Tsunoda, R. T.; Thampi, S. V.; Gurubaran, S.

    2012-04-01

    The GNU Radio Beacon Receiver (GRBR) Network has been recently established to provide coverage of Southeast Asia and Pacific low-latitude regions, with planned extensions into the Indian and African longitude sectors. With the availability of CERTO (Coherent Electromagnetic Radio Tomography) beacon transmissions from Communication/Navigation Outage Forecasting System (C/NOFS) satellite, which is in a unique low-inclination (13°) orbit, it is now possible to study zonal large scale wave structure (LSWS) in ionospheric total electron content (TEC) with fine spatial resolution over a wide longitudinal region. An automated procedure to determine absolute TEC from relative TEC measurements for low inclination CNOFS orbits has been implemented through a simple single station procedure for initial offset estimation, which is shown to be consistent with the better established two station method and with observations from a Digisonde. The LSWS is extracted by subtracting the background variation from longitudinal variation of TEC. The upwellings of LSWS manifest as depletions in the residual TEC variations. Further, these zonal structures have been found, in general, to be aligned with geomagnetic field lines, and the scintillation patches have been found to align with the west walls of TEC depletions. This spatial alignment recapitulates the premise that the observed zonal wave-like structures in TEC are the manifestations of bottom side LSWS. Hence, the methodology presented in this paper, would prove useful in future, to study the characteristics of LSWS on a regular basis.

  19. SOPHOS -- SOuth Pole High-altitude ObServatory: Prototyping A Large Diameter, Sparsely Filled, Phased Array Telescope on a Tethered Aerostat in Antarctica

    NASA Astrophysics Data System (ADS)

    Ford, Holland; Bally, J.; Bartko, F.; Bely, P.; Brown, R.; Burg, R.; Crocker, J.; Dopita, M.; Illingworth, G.; Tilly, J.; White, R.

    1993-12-01

    Extrapolations of the cost and weight of the present Hubble Space Telescope to larger diameters lead to telescopes which are very heavy and expensive. We plan to build a prototype of a diffraction limited, large space telescope and fly the prototype on a tethered aerostat in Antarctica. During the austral winter the cold, stable, dry, high altitude environment over the Antarctic plateau provides a relatively inexpensive way to test prototypes of space instrumentation. A standard 71 m aerostat can lift a 2000 to 4000 lb payload to a height of 6 km above the 3 km high Antarctic plateau, depending on the weight of the tether. The tether can carry 20 kwatts of power to the telescope and aerostat, and can transmit data at high rates through a fiber. As an intermediate step, we plan to fly a passively cooled 2.4-m IR telescope. At a pressure of 300mb, the overburden of Antarctic water vapor is expected to be under 10 microns of precipitable water. Very long duration exposures in a low background environment will permit the balloon telescope to image fainter objects than any instrument on the Earth or presently in Space. We intend to use the IR and optical telescopes for optical and near IR high angular resolution imaging of the centers of active galaxies, high redshift galaxies, and circumstellar disks and brown dwarfs around nearby stars. Our present concept for the final optical telescope is a sparsely filled array of six 80-cm mirrors on a 6-m diameter circle. Each mirror will be a segment of an f/1 RC primary. The mirrors will have an unequal spacing around the circumference which optimizes spatial coverage of the UV plane. The tethered aerostat will provide a high altitude polar platform which will be invaluable for optical, IR and sub-mm, solar, meterological, and atmospheric chemistry observations.

  20. Investigation of standing-wave formation in a human skull for a clinical prototype of a large-aperture, transcranial MR-guided focused ultrasound (MRgFUS) phased array: an experimental and simulation study.

    PubMed

    Song, Junho; Pulkkinen, Aki; Huang, Yuexi; Hynynen, Kullervo

    2012-02-01

    Standing-wave formation in an ex vivo human skull was investigated using a clinical prototype of a 30-cm diameter with 15-cm radius of curvature, low-frequency (230 kHz), hemispherical transcranial magnetic resonance-guided focused ultrasound phased array. Experimental and simulation studies were conducted with changing aperture size and f -number configurations of the phased array and qualitatively and quantitatively examined the acoustic pressure variation at the focus due to standing waves. The results demonstrated that the nodes and antinodes of standing wave produced by the small-aperture array were clearly seen at approximately every 3 mm. The effect of the standing wave became more pronounced as the focus was moved closer to skull base. However, a sharp focus was seen for the full array, and there was no such standing-wave pattern in the acoustic plane or near the skull base. This study showed that the fluctuation pressure amplitude would be greatly reduced by using a large-scale, hemispherical phased array with a low f-number.

  1. Investigation of standing wave formation in a human skull for a clinical prototype of a large-aperture, transcranial MR-guided Focused Ultrasound (MRgFUS) phased array: An experimental and simulation study

    PubMed Central

    Song, Junho; Pulkkinen, Aki; Huang, Yuexi; Hynynen, Kullervo

    2014-01-01

    Standing wave formation in an ex vivo human skull was investigated using a clinical prototype of a 30 cm diameter with 15 cm radius of curvature, low frequency (230 kHz), hemispherical transcranial Magnetic Resonance guided Focused Ultrasound (MRgFUS) phased-array. Experimental and simulation studies were conducted with changing aperture size and f-number configurations of the phased array, and qualitatively and quantitatively examined the acoustic pressure variation at the focus due to standing waves. The results demonstrated that the nodes and anti-nodes of standing wave produced by the small aperture array were clearly seen at approximately every 3 mm. The effect of the standing wave became more pronounced as the focus was moved closer to skull base. However, a sharp focus was seen for the full array, and there was no such standing wave pattern in the acoustic plane or near the skull base. This study showed that the fluctuation pressure amplitude would be greatly reduced by using a large-scale, hemispherical phased array with a low f-number. PMID:22049360

  2. Long-term home range use in white-handed gibbons (Hylobates lar) in Khao Yai National Park, Thailand.

    PubMed

    Bartlett, Thad Q; Light, Lydia E O; Brockelman, Warren Y

    2016-02-01

    Ranging behavior is an important element of how nonhuman primates obtain sufficient resources to ensure biological maintenance and reproductive success. As most primates live in permanent social groups, group members must balance the benefits of group living with the costs of intragroup competition for resources. One way to mitigate the cost of intragroup feeding competition is to increase foraging-related travel, thereby increasing the number of patches visited. As a result we might expect home range size to increase as a function of group size. On the other hand, for perennially territorial species, ranging behavior may be constrained by the ranging requirements of territorial defense or by the location of neighboring territories, which would result in long-term stability in the size and location of a group's home range. In this study, we examined changes in range-use characteristics in one well-habituated group of white-handed gibbons (Hylobates lar) during three study periods over a 10-year span. Group size changed from five members, two adults, two juveniles, and one infant, in 1994, to two adults in 2002, and to three adults and one sub-adult in 2004. Despite inter-annual changes in core area use we found that home range location was highly stable across years. Nevertheless, home range size was larger and daily path length significantly longer in 2002 relative to 1994 when a dependent infant was present in the group. The percentage of time adults spent resting was also significantly greater in 1994 when the infant was present. These findings highlight the importance of considering group composition, in addition to group size, when evaluating the determinants of ranging behavior. We also consider the influence of individual and shared knowledge on home range stability.

  3. [Effect of long-term treatment with octreotide-lar in a TSH-secreting pituitary macroadenoma and secondary hyperthyroidism].

    PubMed

    Del Monte, P; Bernasconi, D; Ruelle, A; Marugo, A; Marugo, M; Torre, R

    2005-06-01

    A 74 year-old man was admitted to the hospital for heart failure and atrial fibrillation episodes. He had been irregularly treated for hyperthyroidism during the previous 3 years, with poor control. Thyroid function evaluation showed secondary hyperthyroidism, with high free thyroid hormone levels and TSH inappropriately in the high-normal range (4.2 mU/ml), only slightly responsive to TRH-stimulation (6 microU/ml). Alpha-subunits were hyper-responsive to TRH stimulation (+123%). Thyroid autoimmunity tests were negative and ultrasonography evidenced a diffusely enlarged gland. Magnetic resonance (MR) imaging of the pituitary showed a macroadenoma. The patient underwent transphenoidal adenomectomy, and immunohistochemistry confirmed the diagnosis of a TSH-secreting pituitary macroadenoma. A moderate secondary hyperthyroidism was still present and a new MR evidenced residual disease, involving the right cavernous sinus. A (111)In-octreoscan revealed an increased captation in this area. The patient was treated with octreotide-Lar (20 mg/monthly), which normalized FT3, FT4 and TSH levels already after 3 months of therapy. This effect is still maintained at 42 months of treatment. MR imaging showed a reduction in the residual lesion after 18 months (>50% in comparison with postsurgical MR) and a further decrease after 36 months of treatment). This suggests that the antiproliferative effect on the adenomatous cells is progressive and continues over time. This patients did not receive radiotherapy, so this action is entirely due to the medical treatment. No significant side effects developed and the patient's compliance was good. He has not had further arrhythmic episodes.

  4. Interspecific territoriality in gibbons (Hylobates lar and H. pileatus) and its effects on the dynamics of interspecies contact zones.

    PubMed

    Suwanvecho, Udomlux; Brockelman, Warren Y

    2012-01-01

    We investigated the ecology and interspecific interactions of the two gibbon species (Hylobates lar and H. pileatus) that overlap in distribution within a narrow zone of contact in the headwaters of the Takhong River at Khao Yai National Park in central Thailand. The zone is about 10-km wide, with phenotypic hybrids comprising 6.5% of the adult population. We compared species with respect to diet, territory size, intra- and interspecific group encounters, and territory quality. The two gibbon species exploited the same types of resources within their territories despite variation in the relative abundance of food-plant species between territories. The gibbons were interspecifically territorial, and males of both species displayed aggressive behaviors at both intraspecific and interspecific territorial boundaries. There was no marked difference in the amount of overlap between territories of conspecific and heterospecific pairs of groups. Although the habitat was not homogeneous, territory quality did not vary significantly between species. The species have not diverged in habitat preference or in diet. Neither species dominated in interspecific encounters, and both were reproducing well in the contact zone. We analyzed the potential consequences of several types of interspecific interactions on individual dispersal options and on the structure of the contact zone. Interference competition through interspecific territoriality affects the dispersal of individuals into the range of the other species. In general, territorial competition coupled with limited hybridization leads to predictions of a narrow contact zone or parapatry between species; thus, behavioral and ecological interactions between species need to be considered as potential factors in explaining range borders of primate species.

  5. Energy Resolution of a Large-Scale Liquid Argon Detector

    NASA Astrophysics Data System (ADS)

    Wood, Kevin; Mishra, Sanjib; LBNE Collaboration

    2015-04-01

    The high granularity and feasibility of large-scale construction makes the Liquid Argon Time Projection Chamber (LArTPC) a suitable technology for the Long Baseline Neutrino Experiment (LBNE) far detector. Particle identification relies largely on the topology and calorimetric information from the signature left in the detector. The measurements LBNE intends to make depend on accurately distinguishing charged current electron neutrino events from neutral current background events. A neutrino event featuring an electron produced by νe interaction will tag it as signal; although, gammas from π0 decays in neutral current events induce electromagnetic showers that resemble those of an electron. The granularity and high energy resolution of LArTPCs enable dE/dx to be extracted from the beginning of these showers which helps separate gammas from electrons and, ultimately, charged current electron neutrino events from neutral current events. Presented here is an estimation of the technology's energy resolution and a demonstration of its capabilities for separating electrons and gammas using dE/dx. Sanjib works closely with Kevin on the presented material.

  6. Different Alleles of a Gene Encoding Leucoanthocyanidin Reductase (PaLAR3) Influence Resistance against the Fungus Heterobasidion parviporum in Picea abies.

    PubMed

    Nemesio-Gorriz, Miguel; Hammerbacher, Almuth; Ihrmark, Katarina; Källman, Thomas; Olson, Åke; Lascoux, Martin; Stenlid, Jan; Gershenzon, Jonathan; Elfstrand, Malin

    2016-08-01

    Despite the fact that fungal diseases are a growing menace for conifers in modern silviculture, only a very limited number of molecular markers for pathogen resistance have been validated in conifer species. A previous genetic study indicated that the resistance of Norway spruce (Picea abies) to Heterobasidion annosum s.l., a pathogenic basidiomycete species complex, is linked to a quantitative trait loci that associates with differences in fungal growth in sapwood (FGS) that includes a gene, PaLAR3, which encodes a leucoanthocyanidin reductase. In this study, gene sequences showed the presence of two PaLAR3 allelic lineages in P. abies. Higher resistance was associated with the novel allele, which was found in low frequency in the four P. abies populations that we studied. Norway spruce plants carrying at least one copy of the novel allele showed a significant reduction in FGS after inoculation with Heterobasidion parviporum compared to their half-siblings carrying no copies, indicating dominance of this allele. The amount of (+) catechin, the enzymatic product of PaLAR3, was significantly higher in bark of trees homozygous for the novel allele. Although we observed that the in vitro activities of the enzymes encoded by the two alleles were similar, we could show that allele-specific transcript levels were significantly higher for the novel allele, indicating that regulation of gene expression is responsible for the observed effects in resistance, possibly caused by differences in cis-acting elements that we observe in the promoter region of the two alleles.

  7. Large diameter astromast development, phase 1

    NASA Technical Reports Server (NTRS)

    Preiswerk, P. R.; Finley, L. A.; Knapp, K.

    1983-01-01

    Coilable-longeron lattice columns called Astromasts (trademark) were manufactured for a variety of spacecraft missions. These flight structures varied in diameter from 0.2 to 0.5 meter (9 to 19 in.), and the longest Astromast of this type deploys to a length of 30 meters (100 feet). A double-laced diagonal Astromast design referred to as the Supermast (trademark) which, because it has shorter baylengths than an Astromast, is approximately four times as strong. The longeron cross section and composite material selection for these structures are limited by the maximum strain associated with stowage and deployment. As a result, future requirements for deployable columns with high stiffness and strength require the development of both structures in larger diameters. The design, development, and manufacture of a 6.1-m-long (20-ft), 0.75-m-diameter (30-in.), double-laced diagonal version of the Astromast is described.

  8. Solid-phase extraction combined with large volume injection-programmable temperature vaporization-gas chromatography-mass spectrometry for the multiresidue determination of priority and emerging organic pollutants in wastewater.

    PubMed

    Bizkarguenaga, E; Ros, O; Iparraguirre, A; Navarro, P; Vallejo, A; Usobiaga, A; Zuloaga, O

    2012-07-20

    In the present work the simultaneous extraction for the multiresidue determination in wastewater samples of organic compounds such as polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), pesticides, polycyclic aromatic hydrocarbons (PAHs), phthalate esters (PEs), alkylphenols (APs), bisphenol A (BPA) or hormones included in different lists of priority and emerging pollutants because of their action as endocrine disrupting compounds (EDCs) was developed. Different solid phase extraction (SPE) variables such as the nature of the solid phase (Oasis-HLC, C18 and Lichrolut), the sample volume, the addition of MeOH and NaCl, the pH of the water phase and the volume of the eluent solvent were optimized in order to analyze simultaneously the priority and emerging families of pollutants mentioned above. Good recoveries were obtained for Milli-Q water (80-120%), however, since the use of deuterated analogues and dilution of the sample did not correct the matrix effect, additional SPE clean-up step using Florisil® cartridges was necessary to obtain good results for wastewater samples (80-125%). In order to improve the limits of detection (LODs), large volume injection (LVI) using programmable temperature vaporizer (PTV) coupled to gas chromatography-mass spectrometry (GC-MS) was also optimized. Since analytes losses in the case of the most volatile congeners occurred during the derivatization step and no separation of the derivatized and the non-derivatized analytes was possible during SPE elution, two different injections were optimized for each analyte group. LODs were in good agreement with those found in the literature and relative standard deviations (RSDs) were in the 10-25% range for Milli-Q and 12-30% for wastewater samples. The method was finally applied to the determination of target analytes in three different wastewater treatment plants (WWTPs, Bakio, Gernika and Galindo (Spain)) and in one water purification plant (WPP) in Zornotza (Spain).

  9. Modeling of Large-Scale Functional Brain Networks Based on Structural Connectivity from DTI: Comparison with EEG Derived Phase Coupling Networks and Evaluation of Alternative Methods along the Modeling Path

    PubMed Central

    Cheng, Bastian; Messé, Arnaud; Thomalla, Götz; Gerloff, Christian; König, Peter

    2016-01-01

    In this study, we investigate if phase-locking of fast oscillatory activity relies on the anatomical skeleton and if simple computational models informed by structural connectivity can help further to explain missing links in the structure-function relationship. We use diffusion tensor imaging data and alpha band-limited EEG signal recorded in a group of healthy individuals. Our results show that about 23.4% of the variance in empirical networks of resting-state functional connectivity is explained by the underlying white matter architecture. Simulating functional connectivity using a simple computational model based on the structural connectivity can increase the match to 45.4%. In a second step, we use our modeling framework to explore several technical alternatives along the modeling path. First, we find that an augmentation of homotopic connections in the structural connectivity matrix improves the link to functional connectivity while a correction for fiber distance slightly decreases the performance of the model. Second, a more complex computational model based on Kuramoto oscillators leads to a slight improvement of the model fit. Third, we show that the comparison of modeled and empirical functional connectivity at source level is much more specific for the underlying structural connectivity. However, different source reconstruction algorithms gave comparable results. Of note, as the fourth finding, the model fit was much better if zero-phase lag components were preserved in the empirical functional connectome, indicating a considerable amount of functionally relevant synchrony taking place with near zero or zero-phase lag. The combination of the best performing alternatives at each stage in the pipeline results in a model that explains 54.4% of the variance in the empirical EEG functional connectivity. Our study shows that large-scale brain circuits of fast neural network synchrony strongly rely upon the structural connectome and simple computational

  10. Mechanisms of membrane protein insertion into liposomes during reconstitution procedures involving the use of detergents. 1. Solubilization of large unilamellar liposomes (Prepared by reverse-phase evaporation) by Triton X-100 octyl glucoside, and sodium cholate

    SciTech Connect

    Paternostre, M.T.; Roux, M.; Rigaud, J.L.

    1988-04-19

    The mechanisms governing the solubilization by Triton X-100, octyl glucoside, and sodium cholate of large unilamellar liposomes prepared by reverse-phase evaporation were investigated. The solubilization process is described by the three-stage model previously proposed for the detergents. In stage I, detergent monomers are incorporated into the phospholipid bilayers until they saturate the liposomes. At this point, i.e., stage II, mixed phospholipid-detergent micelles begin to form. By stage III, the lamellar to micellar transition is complete and all the phospholipids are present as mixed micelles. The turbidity of liposome preparations was systematically measured as a function of the amount of detergent added for a wide range of phospholipid concentrations. The results allowed a quantitative determination of the effective detergent to lipid molar ratios in the saturated liposomes. The monomer concentrations of the three detergents in the aqueous phase were also determined at the lamellar to micellar transitions. These transitions were also investigated by /sup 31/P NMR spectroscopy, and complete agreement was found with turbidity measurements. Freeze-fracture electron microscopy and permeability studies in the sublytic range of detergent concentrations indicated that during stage I of solubilization detergent partitioning between the aqueous phase and the lipid bilayer greatly affects the basic permeability of the liposomes without significantly changing the morphology of the preparations. A rough approximation of the partition coefficients was derived from the turbidity and permeability data. It is concluded that when performed systematically, turbidity measurements constitute a very convenient and powerful technique for the quantitative study of the liposome solubilization process by detergents.

  11. Online in situ analysis of selected semi-volatile organic compounds in water by automated microscale solid-phase extraction with large-volume injection/gas chromatography/mass spectrometry.

    PubMed

    Li, Yongtao; George, John E; McCarty, Christina L

    2007-12-28

    A fully automated analytical method was developed for the online in situ analysis of selected semi-volatile organic compounds in water. The method used a large-volume injection/gas chromatography/mass spectrometry coupled with a fully automated microscale solid-phase extraction technique, which was based on x-y-z robotic techniques. Water samples were extracted by using a 96-well solid-phase extraction plate. For most analytes included in this study, the obtained linear calibrations ranged from 0.05 to 5.0 microg/L with correlation coefficients of 0.996-1.000, the method detection limits were less than 0.1 microg/L, and the relative recoveries were in the range of 70-120% with a relative standard deviation of less than 15% for fortified reagent water samples. The applications to chlorinated tap water, well water, and river water have been validated. The obtained results were similar to those resulting from fortified reagent water samples for all analytes except metribuzin, bromacil, aldrin, and methoxychlor. Matrix effects were observed for these analytes. In general, this fully automated analytical method was rugged, reliable, and easy to operate, and was capable of providing real-time data to water treatment and distribution systems as well as water reservation and protection systems. In addition, the method could reduce the analytical costs associated with sample collection, transportation, storage, and preparation.

  12. The effect of cromolyn sodium and albuterol on early and late phase bronchoconstriction and airway leukocyte infiltration after allergen challenge of nonanesthetized guinea pigs.

    PubMed

    Hutson, P A; Holgate, S T; Church, M K

    1988-11-01

    We describe the effects of the antiallergic drug cromolyn sodium and the beta 2-selective adrenoceptor agonist albuterol against early and late phase changes in specific airways conductance (sGaw) and leukocyte infiltration into the airways after allergen challenge of nonanesthetized guinea pigs. Inhalation of ovalbumin by sensitized guinea pigs induced three phases of airways obstruction: an early asthmatic response (EAR) peaking at 2 h, a late response (LAR) peaking at 17 h, and a further late response (LLAR) being observed at 72 h. The LAR was accompanied by a 13-fold rise in neutrophils and a four-fold rise in eosinophils recovered by bronchoalveolar lavage (BAL) at 17 h. By 72 h, the BAL content of neutrophils had returned to near normal, whereas eosinophil numbers had risen to 6.7-fold above baseline. Inhalation of an aerosolized solution of cromolyn, 10 mg/ml, 15 min before challenge inhibited both the EAR and LAR and the influx of neutrophils into the airways at 17 h but had no effect on eosinophil accumulation. Inhalation of cromolyn at 6 h, i.e., after the completion of the EAR, inhibited the LAR, the LLAR, and the rise in eosinophils at 72 h but did not reduce the influx of neutrophils at 17 h. Administration of cromolyn at both 15 min before and 6 h after challenge inhibited all changes in sGaw and reduced the accumulation of neutrophils at 17 h and the influx of eosinophils at 72 h. In contrast, inhalation of albuterol, 0.1 mg/ml, 15 min before allergen provocation blocked the EAR and the rise in BAL neutrophils at 17 h but did not inhibit the LAR. Inhalation of albuterol at 6 h partially reversed the LAR but had no effect on either the LLAR or cellular changes. Given at both times, albuterol inhibited the EAR and neutrophil accumulation at 17 h and partially reversed the LAR but produced no other effects.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Measurement of large nonlinear refractive index of natural pigment extracted from Hibiscus rosa-sinensis leaves with a low power CW laser and by spatial self-phase modulation technique

    NASA Astrophysics Data System (ADS)

    Biswas, S.; Kumbhakar, P.

    2017-02-01

    We have reported here, for the first time, to the best of our knowledge, a high nonlinear refractive index (n2e) of a natural pigment extracted from Hibiscus rosa-sinensis leaves by using spatial self-phase modulation technique (SSPM) with a low power CW He-Ne laser radiation at 632.8 nm. It is found by UV-Vis absorption spectroscopic analysis that chlrophyll-a, chlrophyll-b and carotenoid are present in the pigment extract with 56%, 25% and 19%, respectively. The photoluminescence (PL) emission characteristics of the extracted samples have also been measured at room temperature as well as in the temperature range of 283-333 K to investigate the effect of temperature on luminescent properties of the sample. By analyzing the SSPM experimental data, the nonlinear refractive index value of pigment extract has been determined to be 3.5 × 10- 5 cm2/W. The large nonlinear refractive index has been assigned due to asymmetrical structure, molecular reorientation and thermally induced nonlinearity in the sample. The presented results might open new avenues for the green and economical technique of syntheses of organic dyes with such a large nonlinear optical property.

  14. Measurement of large nonlinear refractive index of natural pigment extracted from Hibiscus rosa-sinensis leaves with a low power CW laser and by spatial self-phase modulation technique.

    PubMed

    Biswas, S; Kumbhakar, P

    2017-02-15

    We have reported here, for the first time, to the best of our knowledge, a high nonlinear refractive index (n2e) of a natural pigment extracted from Hibiscus rosa-sinensis leaves by using spatial self-phase modulation technique (SSPM) with a low power CW He-Ne laser radiation at 632.8nm. It is found by UV-Vis absorption spectroscopic analysis that chlrophyll-a, chlrophyll-b and carotenoid are present in the pigment extract with 56%, 25% and 19%, respectively. The photoluminescence (PL) emission characteristics of the extracted samples have also been measured at room temperature as well as in the temperature range of 283-333K to investigate the effect of temperature on luminescent properties of the sample. By analyzing the SSPM experimental data, the nonlinear refractive index value of pigment extract has been determined to be 3.5×10(-5)cm(2)/W. The large nonlinear refractive index has been assigned due to asymmetrical structure, molecular reorientation and thermally induced nonlinearity in the sample. The presented results might open new avenues for the green and economical technique of syntheses of organic dyes with such a large nonlinear optical property.

  15. A simultaneous study of kinetics and thermodynamics of anion transfer across the liquid/liquid interface by means of Fourier transformed large-amplitude square-wave voltammetry at three-phase electrode.

    PubMed

    Deng, Haiqiang; Huang, Xinjian; Wang, Lishi

    2010-12-21

    This paper describes a novel application of Fourier transformed large-amplitude square-wave voltammetry (FT-SWV) in combination with three-phase edge plane pyrolytic graphite (EPPG) electrode to investigate both the kinetics and thermodynamics of anion transfer across the liquid/liquid interface using a conventional three-electrode arrangement. The transfer of anion from aqueous phase to organic phase was electrochemically driven by reversible redox transformation of confined redox probe in the organic phase. The kinetics and thermodynamics of anion transfer were inspected by a so-called "quasi-reversible maximum" (QRM) emerged in the profile of even harmonic components of power spectrum obtained by Fourier transformation (FT) of time-domain total current response and formal potential E(f) of first harmonic voltammogram obtained by application of inverse FT on the power spectrum. Besides, a systematic study of patterns of behavior of a variety of anions at the same concentration and a specific anion at different concentrations on kinetics and thermodynamics and the effect of amplitude ΔE on QRM were also conducted, aiming to optimize the measurement conditions. The investigation mentioned above testified that the ion transfer across the liquid/liquid interface controls the kinetics of overall electrochemical process, regardless of either FT-SWV or traditional SWV investigation. Moreover, either the kinetic probe f(max) or the thermodynamic probe E(f) can be served as a way for analytical applications. Interestingly, a linear relationship between peak currents of the first harmonic components and concentrations of perchlorate anion in the aqueous solutions can be observed, which is somewhat in accordance with a finding obtained by Fourier transformed alternating current voltammetry (FT-ACV) [Bond, A. M.; Duffy, N. W.; Elton, D. M.; Fleming, B. D. Anal. Chem. 2009, 81, 8801-8808]. This may open a new door for analytical detection of a wide spectrum of

  16. Phases and Phase Transitions

    NASA Astrophysics Data System (ADS)

    Gitterman, Moshe

    2014-09-01

    In discussing phase transitions, the first thing that we have to do is to define a phase. This is a concept from thermodynamics and statistical mechanics, where a phase is defined as a homogeneous system. As a simple example, let us consider instant coffee. This consists of coffee powder dissolved in water, and after stirring it we have a homogeneous mixture, i.e., a single phase. If we add to a cup of coffee a spoonful of sugar and stir it well, we still have a single phase -- sweet coffee. However, if we add ten spoonfuls of sugar, then the contents of the cup will no longer be homogeneous, but rather a mixture of two homogeneous systems or phases, sweet liquid coffee on top and coffee-flavored wet sugar at the bottom...

  17. Case study of a 15-year-old boy with McCune-Albright syndrome combined with pituitary gigantism: effect of octreotide-long acting release (LAR) and cabergoline therapy.

    PubMed

    Tajima, Toshihiro; Tsubaki, Junko; Ishizu, Katsura; Jo, Wakako; Ishi, Nobuaki; Fujieda, Kenji

    2008-07-01

    The use of octreotide-LAR and cabergoline therapy has shown great promise in adults with acromegaly; however, the experience in pediatric patients has rarely been reported. We described a clinical course of a 15-year-old boy of McCune-Albright syndrome (MAS) with pituitary gigantism. At the age of 8 years, a growth hormone (GH) and prolactin (PRL) producing pituitary adenoma was diagnosed at our hospital. He also had multiple fibrous dysplasia, so that he was diagnosed as having MAS. The tumor was partially resected, and GNAS1 gene mutation (R201C) was identified in affected tissues. We introduced octreotide to suppress GH secretion (100 mug 2/day s.c). During therapy with octreotide, IGF-1 and GH levels could not be suppressed and the patient frequently complained of nausea from octreotide treatment. Therefore, the therapy was changed to monthly injections of octreotide-LAR at the age of 12.3 years and was partially effective. However, as defect of left visual field worsened due to progressive left optic canal stenosis, he underwent second neurological decompression of the left optic nerve at 13.4 years of age. After surgery, in addition to octreotide-LAR, cabergoline (0.25 mg twice a month) was started. This regimen normalized serum levels of GH and IGF-1; however, he showed impaired glucose tolerance and gallstones at 15.7 years of age. Therefore, the dose of octreotide-LAR was reduced to 10 mg and the dose of cabergoline increased. This case demonstrated the difficulty of treating pituitary gigantism due to MAS. The use of octreotide-LAR and cabergoline should be considered even in pediatric patients; however, adverse events due to octreotide-LAR must be carefully examined.

  18. Implementation factors affecting the large-scale deployment of digital health and well-being technologies: A qualitative study of the initial phases of the 'Living-It-Up' programme.

    PubMed

    Agbakoba, Ruth; McGee-Lennon, Marilyn; Bouamrane, Matt-Mouley; Watson, Nicholas; Mair, Frances S

    2016-12-01

    Little is known about the factors which facilitate or impede the large-scale deployment of health and well-being consumer technologies. The Living-It-Up project is a large-scale digital intervention led by NHS 24, aiming to transform health and well-being services delivery throughout Scotland. We conducted a qualitative study of the factors affecting the implementation and deployment of the Living-It-Up services. We collected a range of data during the initial phase of deployment, including semi-structured interviews (N = 6); participant observation sessions (N = 5) and meetings with key stakeholders (N = 3). We used the Normalisation Process Theory as an explanatory framework to interpret the social processes at play during the initial phases of deployment.Initial findings illustrate that it is clear - and perhaps not surprising - that the size and diversity of the Living-It-Up consortium made implementation processes more complex within a 'multi-stakeholder' environment. To overcome these barriers, there is a need to clearly define roles, tasks and responsibilities among the consortium partners. Furthermore, varying levels of expectations and requirements, as well as diverse cultures and ways of working, must be effectively managed. Factors which facilitated implementation included extensive stakeholder engagement, such as co-design activities, which can contribute to an increased 'buy-in' from users in the long term. An important lesson from the Living-It-Up initiative is that attempting to co-design innovative digital services, but at the same time, recruiting large numbers of users is likely to generate conflicting implementation priorities which hinder - or at least substantially slow down - the effective rollout of services at scale.The deployment of Living-It-Up services is ongoing, but our results to date suggest that - in order to be successful - the roll-out of digital health and well-being technologies at scale requires a delicate and pragmatic trade

  19. Implementation factors affecting the large-scale deployment of digital health and well-being technologies: A qualitative study of the initial phases of the ‘Living-It-Up’ programme

    PubMed Central

    Agbakoba, Ruth; McGee-Lennon, Marilyn; Bouamrane, Matt-Mouley; Watson, Nicholas; Mair, Frances S

    2015-01-01

    Little is known about the factors which facilitate or impede the large-scale deployment of health and well-being consumer technologies. The Living-It-Up project is a large-scale digital intervention led by NHS 24, aiming to transform health and well-being services delivery throughout Scotland. We conducted a qualitative study of the factors affecting the implementation and deployment of the Living-It-Up services. We collected a range of data during the initial phase of deployment, including semi-structured interviews (N = 6); participant observation sessions (N = 5) and meetings with key stakeholders (N = 3). We used the Normalisation Process Theory as an explanatory framework to interpret the social processes at play during the initial phases of deployment. Initial findings illustrate that it is clear − and perhaps not surprising − that the size and diversity of the Living-It-Up consortium made implementation processes more complex within a ‘multi-stakeholder’ environment. To overcome these barriers, there is a need to clearly define roles, tasks and responsibilities among the consortium partners. Furthermore, varying levels of expectations and requirements, as well as diverse cultures and ways of working, must be effectively managed. Factors which facilitated implementation included extensive stakeholder engagement, such as co-design activities, which can contribute to an increased ‘buy-in’ from users in the long term. An important lesson from the Living-It-Up initiative is that attempting to co-design innovative digital services, but at the same time, recruiting large numbers of users is likely to generate conflicting implementation priorities which hinder − or at least substantially slow down − the effective rollout of services at scale. The deployment of Living-It-Up services is ongoing, but our results to date suggest that − in order to be successful − the roll-out of digital health and well-being technologies at scale requires a delicate

  20. Exclusive muon neutrino charged current pion-less topologies. ArgoNeuT results and future prospects in LAr TPC detectors

    SciTech Connect

    Palamara, Ornella

    2016-12-29

    Results from the analysis of charged current pion-less (CC 0-pion) muon neutrino events in argon collected by the ArgoNeuT experiment on the NuMI beam at Fermilab are presented and compared with predictions from Monte Carlo simulations. A novel analysis method, based on the reconstruction of exclusive topologies, fully exploiting the Liquid argon Time Projection Chamber (LAr TPC) technique capabilities, is used to analyze the events, characterized by the presence at the vertex of a leading muon track eventually accompanied by one or more highly ionizing tracks, and study nuclear effects in neutrino interactions on argon nuclei. Multiple protons accompanying the leading muon are visible in the ArgoNeuT events, and measured with a proton reconstruction threshold of 21 MeV kinetic energy. As a result, measurements of (anti-)neutrino CC 0-pion inclusive and exclusive cross sections on argon nuclei are reported. Prospects for future, larger mass LAr TPC detectors are discussed.

  1. Exclusive muon neutrino charged current pion-less topologies. ArgoNeuT results and future prospects in LAr TPC detectors

    DOE PAGES

    Palamara, Ornella

    2016-12-29

    Results from the analysis of charged current pion-less (CC 0-pion) muon neutrino events in argon collected by the ArgoNeuT experiment on the NuMI beam at Fermilab are presented and compared with predictions from Monte Carlo simulations. A novel analysis method, based on the reconstruction of exclusive topologies, fully exploiting the Liquid argon Time Projection Chamber (LAr TPC) technique capabilities, is used to analyze the events, characterized by the presence at the vertex of a leading muon track eventually accompanied by one or more highly ionizing tracks, and study nuclear effects in neutrino interactions on argon nuclei. Multiple protons accompanying themore » leading muon are visible in the ArgoNeuT events, and measured with a proton reconstruction threshold of 21 MeV kinetic energy. As a result, measurements of (anti-)neutrino CC 0-pion inclusive and exclusive cross sections on argon nuclei are reported. Prospects for future, larger mass LAr TPC detectors are discussed.« less

  2. Wideband Linear Phase Modulator

    NASA Technical Reports Server (NTRS)

    Mysoor, Narayan R.; Mueller, Robert O.

    1994-01-01

    Phase modulator for transmission in X band provides large phase deviation that remains nearly linear with voltage over relatively wide range. Operates with low loss over wide frequency band and with stable characteristics over wide temperature range. Phase modulator contains two varactor-diode phase shifters coupled via circulators. Separate drive circuit applies modulating voltages to varactor diodes. Modulation voltages vary in accordance with input to drive circuit.

  3. CGILS Phase 2 LES intercomparison of response of subtropical marine low cloud regimes to CO 2 quadrupling and a CMIP3 composite forcing change: Large eddy simulation of cloud feedbacks

    SciTech Connect

    Blossey, Peter N.; Bretherton, Christopher S.; Cheng, Anning; Endo, Satoshi; Heus, Thijs; Lock, Adrian P.; van der Dussen, Johan J.

    2016-10-27

    We extended Phase 1 of the CGILS large-eddy simulation (LES) intercomparison in order to understand if subtropical marine boundary-layer clouds respond to idealized climate perturbations consistently in six LES models. Here the responses to quadrupled carbon dioxide (“fast adjustment”) and to a composite climate perturbation representative of CMIP3 multimodel mean 2×CO2 near-equilibrium conditions are analyzed. As in Phase 1, the LES is run to equilibrium using specified steady summertime forcings representative of three locations in the Northeast Pacific Ocean in shallow well-mixed stratocumulus, decoupled stratocumulus, and shallow cumulus cloud regimes. Our results are generally consistent with a single-LES study of Bretherton et al. (2013) on which this intercomparison was based. Both quadrupled CO2 and the composite climate perturbation result in less cloud and a shallower boundary layer for all models in well-mixed stratocumulus and for all but a single LES in decoupled stratocumulus and shallow cumulus, corroborating similar findings from global climate models (GCMs). For both perturbations, the amount of cloud reduction varies across the models, but there is less intermodel scatter than in GCMs. Furthermore, the cloud radiative effect changes are much larger in the stratocumulus-capped regimes than in the shallow cumulus regime, for which precipitation buffering may damp the cloud response. In the decoupled stratocumulus and cumulus regimes, both the CO2 increase and CMIP3 perturbations reduce boundary-layer decoupling, due to the shallowing of inversion height.

  4. CGILS Phase 2 LES intercomparison of response of subtropical marine low cloud regimes to CO 2 quadrupling and a CMIP3 composite forcing change: Large eddy simulation of cloud feedbacks

    DOE PAGES

    Blossey, Peter N.; Bretherton, Christopher S.; Cheng, Anning; ...

    2016-10-27

    We extended Phase 1 of the CGILS large-eddy simulation (LES) intercomparison in order to understand if subtropical marine boundary-layer clouds respond to idealized climate perturbations consistently in six LES models. Here the responses to quadrupled carbon dioxide (“fast adjustment”) and to a composite climate perturbation representative of CMIP3 multimodel mean 2×CO2 near-equilibrium conditions are analyzed. As in Phase 1, the LES is run to equilibrium using specified steady summertime forcings representative of three locations in the Northeast Pacific Ocean in shallow well-mixed stratocumulus, decoupled stratocumulus, and shallow cumulus cloud regimes. Our results are generally consistent with a single-LES study ofmore » Bretherton et al. (2013) on which this intercomparison was based. Both quadrupled CO2 and the composite climate perturbation result in less cloud and a shallower boundary layer for all models in well-mixed stratocumulus and for all but a single LES in decoupled stratocumulus and shallow cumulus, corroborating similar findings from global climate models (GCMs). For both perturbations, the amount of cloud reduction varies across the models, but there is less intermodel scatter than in GCMs. Furthermore, the cloud radiative effect changes are much larger in the stratocumulus-capped regimes than in the shallow cumulus regime, for which precipitation buffering may damp the cloud response. In the decoupled stratocumulus and cumulus regimes, both the CO2 increase and CMIP3 perturbations reduce boundary-layer decoupling, due to the shallowing of inversion height.« less

  5. Dacetuzumab plus rituximab, ifosfamide, carboplatin and etoposide as salvage therapy for patients with diffuse large B-cell lymphoma relapsing after rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone: a randomized, double-blind, placebo-controlled phase 2b trial.

    PubMed

    Fayad, Luis; Ansell, Stephen M; Advani, Ranjana; Coiffier, Bertrand; Stuart, Robert; Bartlett, Nancy L; Forero-Torres, Andres; Kuliczkowski, Kazimierz; Belada, David; Ng, Edmund; Drachman, Jonathan G

    2015-01-01

    Single-agent dacetuzumab has demonstrated antitumor activity in relapsed/refractory diffuse large B-cell lymphoma (DLBCL). Preclinical data demonstrated improved dacetuzumab antitumor activity in combination with rituximab, ± chemotherapy. We designed a phase 2b, double-blind, placebo-controlled trial to compare rituximab, ifosfamide, carboplatin and etoposide (R-ICE) + dacetuzumab with R-ICE + placebo in patients with DLBCL who relapsed after rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone (R-CHOP) (ClinicalTrials.gov #NCT00529503). The primary endpoint was complete response (CR); additional endpoints included failure-free survival and overall survival (OS). Overall, 151 patients were randomized (75 dacetuzumab, 76 placebo). No notable differences between arms in demographics or subsequent treatment parameters were observed. Cytopenias, cough and infection were more frequent with dacetuzumab. Futility analysis failed to demonstrate higher CR rates with dacetuzumab (36% dacetuzumab, 42% placebo); consequently, enrollment was stopped. Unplanned post hoc analysis showed that patients who underwent subsequent autologous stem cell transplant experienced improvement in OS (hazard ratio = 0.195, p = 0.004), which may be explained by potential immunomodulatory effects of dacetuzumab on antigen-presenting cells.

  6. Study of Track Ambiguities and Wire Plane Orientation in Single Phase Liquid Argon Time Projection Chambers

    NASA Astrophysics Data System (ADS)

    Bullard, Brendon; Zhang, Chao; Deep Underground Neutrino Experiment Collaboration

    2017-01-01

    The Deep Underground Neutrino Experiment (DUNE) is currently in development and will utilize a ten-kiloton scale liquid argon time projection chamber (LArTPC) to observe neutrinos from a beam produced using protons from the Main Injector at Fermilab. It is difficult to accurately reconstruct tracks traveling nearly parallel to the LArTPC wire planes due to the finite time resolution of the detector and the limitations of using projective wire geometries. Such reconstructed tracks exhibit degeneracy to varying degrees and could have a large enough effect on primary signals and backgrounds to warrant a design change in the DUNE TPCs. We simulated charged current signal and neutral pion decay background events in order to understand the impact on signal efficiency and background rejection in a LArTPC using wire readout planes situated parallel or perpendicular to the neutrino beam. We found that using a perpendicular wire plane significantly reduces the degeneracy problem for both lepton and hadrons. Other aspects of perpendicular TPC design including signal processing are still under study. Department of Energy.

  7. Gibbons (Hylobates pileatus, H. moloch, H. lar, Symphalangus syndactylus) follow human gaze, but do not take the visual perspective of others.

    PubMed

    Liebal, Katja; Kaminski, Juliane

    2012-11-01

    We investigated four gibbon species of two different genera (Hylobates pileatus, H. moloch, H. lar, Symphalangus syndactylus) in terms of their looking behavior in response to a human who either looked up or looked at the gibbon. Comparing those two conditions, gibbons as a group looked up more when the human was looking up, but they also performed more looks in other directions and thus generally looked more in this condition. Unlike great apes, gibbons did not respond differently between conditions when only the first look on every trial was considered. Furthermore, they did not perform double looks up to check where the human was looking and also did not habituate to the human's looks up. This suggests that gibbons co-orient with human gaze, but unlike great apes, they do not take the visual perspective of others.

  8. Phase II Study of Dose-Adjusted EPOCH-Rituximab in Untreated Diffuse Large B-cell Lymphoma with Analysis of Germinal Center and Post-Germinal Center Biomarkers

    PubMed Central

    Wilson, Wyndham H.; Dunleavy, Kieron; Pittaluga, Stefania; Hegde, Upendra; Grant, Nicole; Steinberg, Seth M.; Raffeld, Mark; Gutierrez, Martin; Chabner, Bruce A.; Staudt, Louis; Jaffe, Elaine S.; Janik, John E.

    2008-01-01

    Purpose To assess the clinical outcome and the influence of biomarkers associated with apoptosis inhibition (Bcl-2), tumor proliferation (MIB-1) and cellular differentiation on the outcome with dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin and rituximab (DA-EPOCH-R) infusional therapy in diffuse large B-cell lymphoma and analysis of germinal center B-cell (GCB) and post-GCB subtypes by immunohistochemistry. Patients and Methods Phase II study of 72 patients with untreated de novo DLBCL who were at least 18 years of age and stage II or higher. Radiation consolidation was not permitted. Results Patients had a median age of 50 (range: 19-85) years and 40% had a high-intermediate or high International Prognostic Index (IPI). At five-years, progression-free (PFS) and overall survival (OS) were 79% and 80%, respectively, with a median potential follow-up of 54 months. PFS was 91%, 90%, 67% and 47%, and OS was 100%, 90%, 74% and 37%, for 0-1, 2, 3 and 4-5 IPI factors, respectively, at five-years. The Bcl-2 and MIB-1 biomarkers were not associated with PFS or OS. Based on DA-EPOCH historical controls, rituximab only benefited Bcl-2 positive tumors. Bcl-6 expression was associated with higher PFS whereas GCB exhibited a marginally significant higher PFS compared to post-GCB DLBCL. Conclusion DA-EPOCH-R outcome was not affected by tumor proliferation and rituximab appeared to overcome the adverse effect of Bcl-2. Bcl-6 may identify a biological program associated with a superior outcome. Overall, DA-EPOCH-R shows promising outcome in low and intermediate IPI groups. A molecular model of treatment outcome with rituximab and chemotherapy is presented. PMID:18378569

  9. Background rejection of n+ surface events in GERDA Phase II

    NASA Astrophysics Data System (ADS)

    Lehnert, Björn

    2016-05-01

    The GERDA experiment searches for neutrinoless double beta (0vββ) decay in 76Ge using an array of high purity germanium (HPGe) detectors immersed in liquid argon (LAr). Phase II of the experiment uses 30 new broad energy germanium (BEGe) detectors with superior pulse shape discrimination capabilities compared to the previously used semi-coaxial detector design. By far the largest background component for BEGe detectors in GERDA are n+-surface events from 42K β decays which are intrinsic in LAr. The β particles with up to 3.5 MeV can traverse the 0.5 to 0.9 mm thick electrode and deposit energy within the region of interest for the 0vββ decay. However, those events have particular pulse shape features allowing for a strong discrimination. The understanding and simulation of this background, showing a reduction by up to a factor 145 with pulse shape discrimination alone, is presented in this work.

  10. The trigger readout electronics for the Phase-I upgrade of the ATLAS Liquid Argon calorimeters

    NASA Astrophysics Data System (ADS)

    Xu, Hao

    2017-03-01

    For the Phase-I luminosity upgrade of the LHC a higher granularity trigger readout of the ATLAS Liquid Argon (LAr) Calorimeters is foreseen to enhance the trigger feature extraction and background rejection. The new readout system digitizes the detector signals, grouped into 34000 so-called Super Cells, with 12-bit precision at 40 MHz and transfers the data on optical links to the digital processing system, which computes the Super Cell transverse energies. In this paper, development and test results of the new readout system are presented.

  11. Large N

    NASA Astrophysics Data System (ADS)

    't Hooft, Gerard

    2002-09-01

    In the first part of this lecture, the 1/N expansion technique is illustrated for the case of the large-N sigma model. In large-N gauge theories, the 1/N expansion is tantamount to sorting the Feynman diagrams according to their degree of planarity, that is, the minimal genus of the plane onto which the diagram can be mapped without any crossings. This holds both for the usual perturbative expansion with respect to powers of ˜ {g}2 = g2N, as well as for the expansion of lattice theories in positive powers of 1/˜ {g}2. If there were no renormalization effects, the ˜ {g} expansion would have a finite radius of convergence. The zero-dimensional theory can be used for counting planar diagrams. It can be solved explicitly, so that the generating function for the number of diagrams with given 3-vertices and 4-vertices, can be derived exactly. This can be done for various kinds of Feynman diagrams. We end with some remarks about planar renormalization.

  12. COMMIX-1AR/P: A three-dimensional transient single-phase computer program for thermal hydraulic analysis of single and multicomponent systems

    SciTech Connect

    Garner, P.L.; Blomquist, R.N.; Gelbard, E.M.

    1992-09-01

    The COMMIX-LAR/P computer program is designed for analyzing the steady-state and transient aspects of single-phase fluid flow and heat transfer in three spatial dimensions. This version is an extension of the modeling in COMMIX-lA to include multiple fluids in physically separate regions of the computational domain, modeling descriptions for pumps, radiation heat transfer between surfaces of the solids which are embedded in or surround the fluid, a keg model for fluid turbulence, and improved numerical techniques. The porous-medium formulation in COMMIX allows the program to be applied to a wide range of problems involving both simple and complex geometrical arrangements. The internal aspects of the COMMIX-LAR/P program are presented, covering descriptions of subprograms, variables, and files.

  13. Sequential Introduction of Cations Deriving Large-Grain Csx FA1-x PbI3 Thin Film for Planar Hybrid Solar Cells: Insight into Phase-Segregation and Thermal-Healing Behavior.

    PubMed

    Huang, Jiahao; Xu, Pan; Liu, Jian; You, Xiao-Zeng

    2017-03-01

    Composition engineering of perovskite materials has been demonstrated to be important for high-performance solar cells. Recently, the energy favorable hybridization of formamidinium (FA) and cesium (Cs) in three dimension lead halide perovskites has been attracting increasing attention due to its potential benefit on durability. Herein, we reported a simple and effective method to produce phase-pure CsxFA1-xPbI3 thin film via sequential introduction of cations, in which the FA cation was introduced by interdiffusion annealing in the presence of N-methylimidazole (NMI). NMI was employed as an additive to slow down the crystallization and thus drive the formation of CsxFA1-xPbI3 with micrometer grain size, which probably facilitate the charge dissociation and transportation in photovoltaic devices. More importantly, composition dependent phase-segregation has been revealed and investigated for the first time during the phase-pure mixed-cation perovskites CsxFA1-xPbI3. The present findings demonstrated that suppressing phase-segregation of mixed-cation perovskites by meticulous composition engineering is significant for further development of efficient photovoltaics. It also suggested that phase-pure Cs0.15FA0.85PbI3 may be a promising candidate with superior phase-durability, which performed an efficiency over 16% in planar perovskite solar cells.

  14. Radiation Tolerant Electronics and Digital Processing for the Phase-I Trigger Readout Upgrade of the ATLAS Liquid Argon Calorimeters

    SciTech Connect

    Milic, A.

    2015-07-01

    The high luminosities of L > 10{sup 34} cm{sup -2}s{sup -1} at the Large Hadron Collider (LHC) at CERN produce an intense radiation environment that the detectors and their electronics must withstand. The ATLAS detector is a multi-purpose apparatus constructed to explore the new particle physics regime opened by the LHC. Of the many decay particles observed by the ATLAS detector, the energy of the created electrons and photons is measured by a sampling calorimeter technique that uses Liquid Argon (LAr) as its active medium. The front end (FE) electronic readout of the ATLAS LAr calorimeter located on the detector itself consists of a combined analog and digital processing system. In order to exploit the higher luminosity while keeping the same trigger bandwidth of 100 kHz, higher transverse granularity, higher resolution and longitudinal shower shape information will be provided from the LAr calorimeter to the Level-l trigger processors. New trigger readout electronics have been designed for this purpose, which will withstand the radiation dose levels expected for an integrated luminosity of 3000 fb{sup -1} during the high luminosity LHC (HL-LHC), which is well above the original LHC design qualifications. (authors)

  15. Moon Phases

    ERIC Educational Resources Information Center

    Riddle, Bob

    2010-01-01

    When teaching Moon phases, the focus seems to be on the sequence of Moon phases and, in some grade levels, how Moon phases occur. Either focus can sometimes be a challenge, especially without the use of models and observations of the Moon. In this month's column, the author describes some of the lessons that he uses to teach the phases of the Moon…

  16. Extreme argon purity in a large, non-evacuated cryostat

    SciTech Connect

    Tope, Terry; Adamowski, Mark; Carls, B.; Hahn, A.; Jaskierny, W.; Jostlein, H.; Kendziora, C.; Lockwitz, S.; Pahlka, B.; Plunkett, R.; Pordes, S.; Rebel, B.; Schmitt, R.; Skup, E.; Stancari, M.; Yang, T.

    2014-01-29

    Liquid Argon Time Projection Chambers (LArTPCs) show promise as scalable devices for the large detectors needed for long-baseline neutrino oscillation physics. Over the last several years at Fermilab a staged approach to developing the technology for large detectors has been developed. The TPC detectors require ultra-pure liquid argon with respect to electronegative contaminants such as oxygen and water. The tolerable electronegative contamination level may be as pure as 60 parts per trillion of oxygen. Three liquid argon cryostats operated at Fermilab have achieved the extreme purity required by TPCs. These three cryostats used evacuation to remove atmospheric contaminants as the first purification step prior to filling with liquid argon. Future physics experiments may require very large detectors with tens of kilotonnes of liquid argon mass. The capability to evacuate such large cryostats adds significant cost to the cryostat itself in addition to the cost of a large scale vacuum pumping system. This paper describes a 30 ton liquid argon cryostat at Fermilab which uses purging to remove atmospheric contaminants instead of evacuation as the first purification step. This cryostat has achieved electronegative contamination levels better than 60 parts per trillion of oxygen equivalent. The results of this liquid argon purity demonstration will strongly influence the design of future TPC cryostats.

  17. Home-range characteristics and the influence of seasonality on female reproduction in white-handed gibbons (Hylobates lar) at Khao Yai National Park, Thailand.

    PubMed

    Savini, Tommaso; Boesch, Christophe; Reichard, Ulrich H

    2008-01-01

    A three-year (2001-2003) study was carried out on the home range characteristics of seven wild white-handed gibbon (Hylobates lar) groups focusing on the spatio-temporal distribution of food resources at Khao Yai National Park in northeastern Thailand. These results were combined with 23 years (1980-2003) of reproductive performance data on seven females from the same focal groups. Reproductive performance was equal among females with regard to birth, weaning and maturation ratios, and independent of variation in food availability. Offspring mortality, however, was significantly positively correlated with home-range size. In addition, there was an increase in offspring mortality just after weaning, suggesting that the increase in the daily distance traveled by juveniles contributed to this mortality. Conceptions clustered during the first half of the year when food production was at its peak, which presumably allowed females to accumulate sufficient body reserves to resume ovarian cycling. Our results place Khao Yai gibbons closer to Cercopithecidae than great apes in terms of the temporal pattern of reproductive events, though gestation, lactation, inter-birth interval, and offspring maturation are considerably longer in gibbons, placing them closer to the other apes. Our findings underline the unique phylogenetic position of these small-bodied apes in terms of reproductive patterns in primates.

  18. Feasibility of using everyday abilities scale of India as alternative to mental state examination as a screen in two-phase survey estimating the prevalence of dementia in largely illiterate Indian population

    PubMed Central

    Raina, Sunil Kumar; Chander, Vishav; Raina, Sujeet; Kumar, Dinesh

    2016-01-01

    Introduction: A situation analysis report on elderly in India shows that the literacy rate for persons aged above 60 is 36%. Using HMSE and its modification in the first phase of a two phase study to estimate the prevalence of dementia in such a population must be read with caution as these tests are literacy dependent. We conducted a post hoc analysis to explore the feasibility of using EASI as an alternative to HMSE and its modifications as the first phase screen in two phase surveys to estimate the prevalence of dementia. Materials and Methods: A post hoc analysis was conducted on data obtained from a study conducted on elderly population (60 years and above) from selected geographical areas (Migrant, Urban, Rural and Tribal) of Himachal Pradesh state in North-west India. The co-relation coefficient was used to establish the strength of association between EASI and HMSE and its modification and therefore the feasibility of using it as an alternative. Results: As the scores on EASI rise, the scores on HMSE fall both pointing to identification of the same clinical diagnosis i.e., dementia. Further the Pearson Correlation coefficient at -2.52 was found to be statistically significant. Conclusion: EASI may be used as alternative to mental state examination. PMID:28197006

  19. AUTOMATED ANALYSIS OF AQUEOUS SAMPLES CONTAINING PESTICIDES, ACIDIC/BASIC/NEUTRAL SEMIVOLATILES AND VOLATILE ORGANIC COMPOUNDS BY SOLID PHASE EXTRACTION COUPLED IN-LINE TO LARGE VOLUME INJECTION GC/MS

    EPA Science Inventory

    Data is presented on the development of a new automated system combining solid phase extraction (SPE) with GC/MS spectrometry for the single-run analysis of water samples containing a broad range of organic compounds. The system uses commercially available automated in-line 10-m...

  20. A METHOD FOR AUTOMATED ANALYSIS OF 10 ML WATER SAMPLES CONTAINING ACIDIC, BASIC, AND NEUTRAL SEMIVOLATILE COMPOUNDS LISTED IN USEPA METHOD 8270 BY SOLID PHASE EXTRACTION COUPLED IN-LINE TO LARGE VOLUME INJECTION GAS CHROMATOGRAPHY/MASS SPECTROMETRY

    EPA Science Inventory

    Data is presented showing the progress made towards the development of a new automated system combining solid phase extraction (SPE) with gas chromatography/mass spectrometry for the single run analysis of water samples containing a broad range of acid, base and neutral compounds...

  1. Large strain transduction utilizing phase transition in relaxor-ferroelectric Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals

    NASA Astrophysics Data System (ADS)

    Finkel, Peter; Benjamin, Kim; Amin, Ahmed

    2011-05-01

    In this work, we present experimental evidence that under relatively low level drive (<0.1 MV/m) the large strain (˜0.5%) associated with ferroelectric rhombohedral FR-ferroelectric orthorhombic FO phase transition in domain engineered relaxor-ferroelectric single crystals under compressive stress and bias electric field can be captured. We have demonstrated this in mechanically confined ternary Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals poised at the rhombohedral side of the morphotropic phase boundary. Experimental strain-field results, methods of mechanical confinement and drive, and a low frequency, compact, high source level sound projector design are presented. Transducers that operate on a large strain principle as a design rule will benefit from this development.

  2. Large dielectric tuning and microwave phase shift at low electric field in epitaxial Ba0.5Sr0.5TiO3 on SrTiO3

    NASA Astrophysics Data System (ADS)

    Leach, J. H.; Liu, H.; Avrutin, V.; Xiao, B.; Özgür, Ü.; Morkoç, H.; Das, J.; Song, Y. Y.; Patton, C. E.

    2010-04-01

    Dielectric properties of annealed and as-grown ferroelectric Ba0.5Sr0.5TiO3 (BST) grown by pulsed laser deposition on sputtered BST seed layers on strontium titanate (STO) substrates were investigated at microwave frequencies in the realm of tunability of its dielectric constant as well as phase shifters based on this material. The as-grown layers were nearly fully relaxed with measured lattice parameters nearly identical to those of bulk BST. The tuning of the relative dielectric constant (˜1750 at zero bias at 10 GHz) of the annealed BST was found to be as high as 59% and 56% at 10 and 19 GHz, respectively. The analysis of the loss in the BST results in a measured tan δ of 0.02 for the annealed as well as the unannealed films at a frequency of 18 GHz. Phase shifters also exhibited high tuning with differential phase shift figures of merit of 35 and 55°/dB at a field of 60 kV/cm at 10 and 19 GHz, respectively. Serendipitously, most of the tuning occurs at low fields, and thus we propose a new figure of merit, taking into account the amplitude of applied electric field in order to achieve the phase shift. In this new realm we achieved the values of this overall figure of merit of 1.2 and 1.8° cm/dB kV at 10 and 19 GHz, respectively, using an applied electric field of only 10 kV/cm.

  3. Large dielectric constant ({epsilon}/{epsilon}{sub 0}>6000) Ba{sub 0.4}Sr{sub 0.6}TiO{sub 3} thin films for high-performance microwave phase shifters

    SciTech Connect

    Carlson, C. M.; Rivkin, T. V.; Parilla, P. A.; Perkins, J. D.; Ginley, D. S.; Kozyrev, A. B.; Oshadchy, V. N.; Pavlov, A. S.

    2000-04-03

    We deposited epitaxial Ba{sub 0.4}Sr{sub 0.6}TiO{sub 3} (BST) films via laser ablation on MgO and LaAlO{sub 3} (LAO) substrates for tunable microwave devices. Postdeposition anneals ({approx}1100 degree sign C in O{sub 2}) improved the morphology and overall dielectric properties of films on both substrates, but shifted the temperature of maximum dielectric constant (T{sub max}) up for BST/LAO and down for BST/MgO. These substrate-dependent T{sub max} shifts had opposite effects on the room-temperature dielectric properties. Overall, BST films on MgO had the larger maximum dielectric constant ({epsilon}/{epsilon}{sub 0}{>=}6000) and tunability ({delta}{epsilon}/{epsilon}{>=}65%), but these maxima occurred at 227 K. 30 GHz phase shifters made from similar films had figures of merit (ratio of maximum phase shift to insertion loss) of {approx}45 degree sign /dB and phase shifts of {approx}400 degree sign under 500 V ({approx}13 V/{mu}m) bias, illustrating their utility for many frequency-agile microwave devices. (c) 2000 American Institute of Physics.

  4. Use of LARS system for the quantitative determination of smoke plume lateral diffusion coefficients from ERTS images of Virginia

    NASA Technical Reports Server (NTRS)

    Blais, R. N.; Copeland, G. E.; Lerner, T. H.

    1975-01-01

    A technique for measuring smoke plume of large industrial sources observed by satellite using LARSYS is proposed. A Gaussian plume model is described, integrated in the vertical, and inverted to yield a form for the lateral diffusion coefficient, Ky. Given u, wind speed; y sub l, the horizontal distance of a line of constant brightness from the plume symmetry axis a distance x sub l, downstream from reference point at x=x sub 2, y=0, then K sub y = u ((y sub 1) to the 2nd power)/2 x sub 1 1n (x sub 2/x sub 1). The technique is applied to a plume from a power plant at Chester, Virginia, imaged August 31, 1973 by LANDSAT I. The plume bends slightly to the left 4.3 km from the source and estimates yield Ky of 28 sq m/sec near the source, and 19 sq m/sec beyond the bend. Maximum ground concentrations are estimated between 32 and 64 ug/cu m. Existing meteorological data would not explain such concentrations.

  5. COMMIX-1AR/P: A three-dimensional transient single-phase computer program for thermal hydraulic analysis of single and multicomponent systems. Volume 3, Programmer`s guide

    SciTech Connect

    Garner, P.L.; Blomquist, R.N.; Gelbard, E.M.

    1992-09-01

    The COMMIX-LAR/P computer program is designed for analyzing the steady-state and transient aspects of single-phase fluid flow and heat transfer in three spatial dimensions. This version is an extension of the modeling in COMMIX-lA to include multiple fluids in physically separate regions of the computational domain, modeling descriptions for pumps, radiation heat transfer between surfaces of the solids which are embedded in or surround the fluid, a keg model for fluid turbulence, and improved numerical techniques. The porous-medium formulation in COMMIX allows the program to be applied to a wide range of problems involving both simple and complex geometrical arrangements. The internal aspects of the COMMIX-LAR/P program are presented, covering descriptions of subprograms, variables, and files.

  6. In vivo and in vitro response to octreotide LAR in a TSH-secreting adenoma: characterization of somatostatin receptor expression and role of subtype 5.

    PubMed

    Gatto, Federico; Barbieri, Federica; Castelletti, Lara; Arvigo, Marica; Pattarozzi, Alessandra; Annunziata, Francesca; Saveanu, Alexandru; Minuto, Francesco; Castellan, Lucio; Zona, Gianluigi; Florio, Tullio; Ferone, Diego

    2011-06-01

    Thyrotropin-secreting pituitary adenomas (TSHomas) are a rare cause of hyperthyroidism and account for less than 2% of pituitary adenomas. Medical therapy with somatostatin analogues (SSAs) effectively reduces TSH secretion in approximately 80% of patients and induces shrinkage in about 45% of tumors. According with previous data, resistance to SSA treatment might be due to heterogeneity in somatostatin receptors (SSTRs) expression. We report the case of TSHoma in a 41-year-old man treated with octreotide LAR that caused a dramatic decrease of TSH and thyroid hormones and tumor shrinkage already after 3 months of pre-surgical therapy. In search of potential molecular determinants of octreotide effectiveness, we measured, in primary cultures from this tumor, SSTR and dopamine D2 receptor (D2R) expression, and octreotide and/or cabergoline effects on TSH secretion and cell proliferation. SSTR5 and D2R expression was higher than SSTR2. Octreotide significantly inhibited TSH secretion more effectively than cabergoline (P<0.001), whereas the combined treatment was comparable with cabergoline alone. Similarly, octreotide resulted more effective than cabergoline on cell proliferation, while the combination did not show any additive or synergistic effects. In conclusion, the significant antisecretive and antiproliferative effect of octreotide in this patient might be related to the high expression of SSTR5, in the presence of SSTR2. After reviewing the literature, indeed, in line with previous observations, we hypothesize that SSTR5/SSTR2 ratio in TSHomas may represent a useful marker in predicting the outcome of therapy with SSAs. The role of D2R should be further explored considering that the presence of D2R can influence SSTRs functionality.

  7. Leaf swallowing and parasite expulsion in Khao Yai white-handed gibbons (Hylobates lar), the first report in an Asian ape species.

    PubMed

    Barelli, Claudia; Huffman, Michael A

    2017-03-01

    Leaf swallowing behavior, known as a form of self-medication for the control of nematode and tapeworm infection, occurs widely in all the African great apes (Pan troglodytes schweinfurthii, P. t. troglodytes, P. t. verus, P. t. vellerosus, Pan paniscus, Gorilla gorilla graueri), except mountain gorillas. It is also reported to occur in a similar context across a wide array of other animal taxa including, domestic dogs, wolves, brown bears, and civets. Despite long-term research on Asian great and small apes, this is the first report of leaf swallowing in an Asian species, the white-handed gibbon (Hylobates lar) in Khao Yai National Park, central Thailand. We present the first evidence of leaf swallowing (Gironniera nervosa Planch CANNABACEA) behavior (N = 5 cases) and parasite (Streptopharagus pigmentatus) expulsion (N = 4 cases), recorded during 4,300 hr of direct animal observations during two distinct research projects. We recovered 4-18 rough, hairy, and hispid surfaced leaves from each sample, undigested and folded, from the freshly evacuated feces of five different individuals (2 males, 3 females, 5 to 34+ years old) living in three different social groups, between the hours of 06:00 to 10:30. Based on close inspection of the leaves, as observed in chimpanzees, it was clear that they were taken into the mouth, one at a time, folded and detached from the stem with the teeth before swallowing them whole. All instances occurred during the rainy season, the time when nematode worms were also found in the feces, although they were not found together with leaves in the same feces. These striking similarities in the details of leaf swallowing between white-handed gibbons and African great apes, and other animal species, suggest a similar self-medicative function.

  8. Phase transition sequence in Pb-free 0.96(K{sub 0.5}Na{sub 0.5}){sub 0.95}Li{sub 0.05}Nb{sub 0.93} Sb{sub 0.07}O{sub 3}−0.04BaZrO{sub 3} ceramic with large piezoelectric response

    SciTech Connect

    Gao, Jinghui Zhang, Le; Zhang, Ming; Dai, Ye; Hu, Xinghao; Wang, Dong; Zhong, Lisheng; Li, Shengtao; Ren, Shuai; Hao, Yanshuang Fang, Minxia; Ren, Xiaobing

    2015-07-20

    The piezoceramic 0.96(K{sub 0.5}Na{sub 0.5}){sub 0.95}Li{sub 0.05}Nb{sub 0.93}Sb{sub 0.07}O{sub 3}−0.04BaZrO{sub 3} (KNLNS{sub 0.07}-BZ), which shows large piezoelectric response (d{sub 33} ≈ 425 pC/N), has been considered as one of the promising Pb-free substitutions for Pb(Zr,Ti)O{sub 3}. In this paper, we investigate the phase transition sequence for KNLNS{sub 0.07}-BZ by employing the dielectric measurement, mechanical spectroscopy, as well as Raman spectroscopy. Two ferroelectric-ferroelectric transitions have been detected by inspecting anomalies in the spectra, indicating the existence of three ferroelectric phases. Moreover, in-situ X-ray diffraction study has been further performed on KNLNS{sub 0.07}-BZ to identify the crystal structure for each phase. The result reveals that the phase sequence for KNLNS{sub 0.07}-BZ evolves from tetragonal (T) to rhombohedral (R) via an intermediate orthorhombic (O) phase. And the piezoelectric-optimal region for KNLNS{sub 0.07}-BZ locates on a T-O boundary rather than the previously reported T-R boundary. Strong piezoelectricity may stem from the easier polarization rotation on the T-O boundary with reduced polarization anisotropy.

  9. UPVG phase 2 report

    SciTech Connect

    1995-08-01

    The Utility PhotoVoltaic Group (UPVG), supported by member dues and a grant from the US Department of Energy, has as its mission the acceleration of the use of cost-effective small-scale and emerging large-scale applications of photovoltaics for the benefit of electric utilities and their customers. Formed in October, 1992, with the support of the American Public Power Association, Edison Electric Institute, and the National Rural Electric Cooperative Association, the UPVG currently has 90 members from all sectors of the electric utility industry. The UPVG`s efforts as conceived were divided into four phases: Phase 0--program plan; Phase 1--organization and strategy development; Phase 2--creating market assurance; and Phase 3--higher volume purchases. The Phase 0 effort developed the program plan and was completed early in 1993. The Phase 1 goal was to develop the necessary background information and analysis to lead to a decision as to which strategies could be undertaken by utilities to promote greater understanding of PV markets and achieve increased volumes of PV purchases. This report provides the details of the UPVG`s Phase 2 efforts to initiate TEAM-UP, its multiyear, 50-MW hardware initiative.

  10. PHASE DETECTOR

    DOEpatents

    Kippenhan, D.O.

    1959-09-01

    A phase detector circuit is described for use at very high frequencies of the order of 50 megacycles. The detector circuit includes a pair of rectifiers inverted relative to each other. One voltage to be compared is applied to the two rectifiers in phase opposition and the other voltage to be compared is commonly applied to the two rectifiers. The two result:ng d-c voltages derived from the rectifiers are combined in phase opposition to produce a single d-c voltage having amplitude and polarity characteristics dependent upon the phase relation between the signals to be compared. Principal novelty resides in the employment of a half-wave transmission line to derive the phase opposing signals from the first voltage to be compared for application to the two rectifiers in place of the transformer commonly utilized for such purpose in phase detector circuits for operation at lower frequency.

  11. Interstitial Lung Disease Associated with mTOR Inhibitors in Solid Organ Transplant Recipients: Results from a Large Phase III Clinical Trial Program of Everolimus and Review of the Literature

    PubMed Central

    Lopez, Patricia

    2014-01-01

    Interstitial lung disease (ILD) has been reported with the use of mammalian target of rapamycin inhibitors (mTORi). The clinical and safety databases of three Phase III trials of everolimus in de novo kidney (A2309), heart (A2310), and liver (H2304) transplant recipients (TxR) were searched using a standardized MedDRA query (SMQ) search for ILD followed by a case-by-case medical evaluation. A literature search was conducted in MEDLINE and EMBASE. Out of the 1,473 de novo TxR receiving everolimus in Phase III trials, everolimus-related ILD was confirmed in six cases (one kidney, four heart, and one liver TxR) representing an incidence of 0.4%. Everolimus was discontinued in three of the four heart TxR, resulting in ILD improvement or resolution. Outcome was fatal in the kidney TxR (in whom everolimus therapy was continued) and in the liver TxR despite everolimus discontinuation. The literature review identified 57 publications on ILD in solid organ TxR receiving everolimus or sirolimus. ILD presented months or years after mTORi initiation and symptoms were nonspecific and insidious. The event was more frequent in patients with a late switch to mTORi. In most cases, ILD was reversed after prompt mTORi discontinuation. ILD induced by mTORi is an uncommon and potentially fatal event warranting early recognition and drug discontinuation. PMID:25580277

  12. Phase stability tuning in the Nb{sub x}Zr{sub 1-x}N thin-film system for large stacking fault density and enhanced mechanical strength

    SciTech Connect

    Joelsson, T.; Hultman, L.; Hugosson, H.W.; Molina-Aldareguia, J.M.

    2005-03-28

    The phase stability of hexagonal WC-structure and cubic NaCl-structure 4d transition metal nitrides was calculated using first-principles density functional theory. It is predicted that there is a multiphase or polytypic region for the 4d transition metal nitrides with a valence electron concentration around 9.5 to 9.7 per formula unit. For verification, epitaxial Nb{sub x}Zr{sub 1-x}N (0{<=}x{<=}1) was grown by reactive magnetron sputter deposition on MgO(001) substrates and analyzed with transmission electron microscopy (TEM) and x-ray diffraction. The defects observed in the films were threading dislocations due to nucleation and growth on the lattice-mismatched substrate and planar defects (stacking faults) parallel to the substrate surface. The highest defect density was found at the x=0.5 composition. The nanoindentation hardness of the films varied between 21 GPa for the binary nitrides, and 26 GPa for Nb{sub 0.5}Zr{sub 0.5}N. Unlike the cubic binary nitrides, no slip on the preferred <110>{l_brace}110{r_brace} slip system was observed. The increase in hardness is attributed to the increase in defect density at x=0.5, as the defects act as obstacles for dislocation glide during deformation. The findings present routes for the design of wear-resistant nitride coatings by phase stability tuning.

  13. A robust and effective time-independent route to the calculation of Resonance Raman spectra of large molecules in condensed phases with the inclusion of Duschinsky, Herzberg-Teller, anharmonic, and environmental effects

    PubMed Central

    Egidi, Franco; Bloino, Julien; Cappelli, Chiara; Barone, Vincenzo

    2015-01-01

    We present an effective time-independent implementation to model vibrational resonance Raman (RR) spectra of medium-large molecular systems with the inclusion of Franck-Condon (FC) and Herzberg-Teller (HT) effects and a full account of the possible differences between the harmonic potential energy surfaces of the ground and resonant electronic states. Thanks to a number of algorithmic improvements and very effective parallelization, the full computations of fundamentals, overtones, and combination bands can be routinely performed for large systems possibly involving more than two electronic states. In order to improve the accuracy of the results, an effective inclusion of the leading anharmonic effects is also possible, together with environmental contributions under different solvation regimes. Reduced-dimensionality approaches can further enlarge the range of applications of this new tool. Applications to imidazole, pyrene, and chlorophyll a1 in solution are reported, as well as comparisons with available experimental data. PMID:26550003

  14. Y-doped La{sub 0.7}Ca{sub 0.3}MnO{sub 3} manganites exhibiting a large magnetocaloric effect and the crossover of first-order and second-order phase transitions

    SciTech Connect

    Phan, The-Long; Jung, C. U.; Lee, B. W.; Ho, T. A.; Manh, T. V.; Dang, N. T.; Thanh, T. D.

    2015-10-14

    We prepared orthorhombic La{sub 0.7−x}Y{sub x}Ca{sub 0.3}MnO{sub 3} samples (x = 0, 0.04, 0.06, and 0.08) by conventional solid-state reaction and then studied their magnetic properties and magnetocaloric (MC) effect based on magnetization versus temperature and magnetic-field measurements, M(T, H). The experimental results revealed that an x increase in La{sub 0.7−x}Y{sub x}Ca{sub 0.3}MnO{sub 3} reduced the ferromagnetic-paramagnetic transition temperature (T{sub C}) from 260 K (for x = 0) to ∼126 K (for x = 0.08). Around the T{sub C}, maximum magnetic-entropy changes for a magnetic-field variation interval H = 50 kOe are about 10.7, 8.5, 7.4, and 5.8 J·kg{sup −1}·K{sup −1} for x = 0, 0.04, 0.06, and 0.08, respectively, corresponding to refrigerant capacities RC = 250–280 J·kg{sup −1}. These values are comparable to those of some conventional MC materials, revealing the applicability of La{sub 0.7−x}Y{sub x}Ca{sub 0.3}MnO{sub 3} in magnetic refrigeration. Using the Arrott method and scaling hypothesis as analyzing high-field M(H, T) data, and the universal-curve construction of the magnetic entropy change, we found a magnetic-phase separation. While the samples x = 0−0.06 exhibit a first-order magnetic phase transition, x = 0.08 exhibits the crossover of the first-to-second-order phase transformation (with its critical-exponent values close to those expected for the tricritical mean-field theory) and has the presence of ferromagnetic clusters even above the T{sub C}. Such the variations in the magnetism and MC effect are related to the changes in structural parameters caused by the Y substitution for La because Y doping does not change the concentration ratio of Mn{sup 3+}/Mn{sup 4+}.

  15. Phase contrast MR angiography techniques.

    PubMed

    Dumoulin, C L

    1995-08-01

    Phase contrast MR methods encode information from macroscopic motion into the phase of the MR signal. Phase contrast methods can be applied with small and large fields-of-view, can give quantitative measures of velocity, and provide excellent suppression of signals from stationary tissue. Unlike time-of-flight methods, phase contrast methods directly measure flow and thus are not hindered by the artifactual appearance of tissue having short T1. Phase contrast angiograms can be two-dimensional (thin slice or projectile), three-dimensional, and/or time resolved and have applications throughout the body.

  16. Heat exchanger-ingot casting/slicing process, phase 1: Silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

    NASA Technical Reports Server (NTRS)

    Schmid, F.; Khattak, C. P.

    1977-01-01

    A controlled growth, heat-flow and cool-down process is described that yielded silicon with a high degree of single crystallinity. Even when the seed melted out, very large grains formed. Solar cell samples made from cast material yielded conversion efficiency of over 9%. Representative characterizations of grown silicon demonstrated a dislocation density of less than 100/sq cm and a minority carrier diffusion length of 31 micron. The source of silicon carbide in silicon ingots was identified to be from graphite retainers in contact with silica crucibles. Higher growth rates were achieved with the use of a graphite plug at the bottom of the silica crucible.

  17. Silicon Ingot Casting - Heat Exchanger Method Multi-wire Slicing - Fixed Abrasive Slicing Technique. Phase 3 Silicon Sheet Growth Development for the Large Area Sheet Task of the Low-cost Solar Array Project

    NASA Technical Reports Server (NTRS)

    Schmid, F.; Khattak, C. P.

    1979-01-01

    Several 20 cm diameter silicon ingots, up to 6.3 kg. were cast with good crystallinity. The graphite heat zone can be purified by heating it to high temperatures in vacuum. This is important in reducing costs and purification of large parts. Electroplated wires with 45 um synthetic diamonds and 30 um natural diamonds showed good cutting efficiency and lifetime. During slicing of a 10 cm x 10 cm workpiece, jerky motion occurred in the feed and rocking mechanisms. This problem is corrected and modifications were made to reduce the weight of the bladeheat by 50%.

  18. A Double-Moment Multiple-Phase Four-Class Bulk Ice Scheme. Part II: Simulations of Convective Storms in Different Large-Scale Environments and Comparisons with other Bulk Parameterizations.

    NASA Astrophysics Data System (ADS)

    Schoenberg Ferrier, Brad; Tao, Wei-Kuo; Simpson, Joanne

    1995-04-01

    Part I of this study described a detailed four-class bulk ice scheme (4ICE) developed to simulate the hydro-meteor profiles of convective and stratiform precipitation associated with mesoscale convective systems. In Part II, the 4ICE scheme is incorporated into the Goddard Cumulus Ensemble (GCE) model and applied without any `tuning' to two squall lines occurring in widely different environments, namely, one over the `Pica) ocean in the Global Atmospheric Research Program's (GARP) Atlantic Tropical Experiment (GATE) and the other over a midlatitude continent in the Cooperative Huntsville Meteorological Experiment (COHMEX). Comparisons were made both with earlier three-class ice formulations and with observations. In both cases, the 4ICE scheme interacted with the dynamics so as to resemble the observations much more closely than did the model runs with either of the three-class ice parameterizations. The following features were well simulated in the COHMEX case: a lack of stratiform rain at the surface ahead of the storm, reflectivity maxima near 60 dBZ in the vicinity of the melting level, and intense radar echoes up to near the tropopause. These features were in strong contrast with the GATE simulation, which showed extensive trailing stratiform precipitation containing a horizontally oriented radar bright band. Peak reflectivities were below the melting level, rarely exceeding 50 dBz, with a steady decrease in reflectivity with height above. With the other bulk formulations, the large stratiform rain areas were not reproduced in the GATE conditions.The microphysical structure of the model clouds in both environments were more realistic than that of earlier modeling efforts. Number concentrations of ice of O(100 L1) occurred above 6 km in the GATE model clouds as a result of ice enhancement and rime splintering in the 4ICE runs. These processes were more effective in the GATE simulation, because near the freezing level the weaker updrafts were comparable in

  19. Stable operation with gain of a double phase Liquid Argon LEM-TPC with a 1 mm thick segmented LEM

    NASA Astrophysics Data System (ADS)

    Resnati, F.; Badertscher, A.; Curioni, A.; Horikawa, S.; Knecht, L.; Lussi, D.; Marchionni, A.; Natterer, G.; Rubbia, A.; Viant, T.

    2011-07-01

    In this paper we present results from a test of a small Liquid Argon Large Electron Multiplier Time Projection Chamber (LAr LEM-TPC). This detector concept provides a 3D-tracking and calorimetric device capable of charge amplification, suited for next-generation neutrino detectors and possibly direct Dark Matter searches. During a test of a 3 lt chamber equipped with a 10×10 cm2 readout, cosmic muon data was recorded during three weeks of data taking. A maximum gain of 6.5 was achieved and the liquid argon was kept pure enough to ensure 20 cm drift (O(ppb) O2 equivalent).

  20. Silicon Ingot Casting - Heat Exchanger Method (HEM). Multi-Wire Slicing - Fixed Abrasive Slicing Technique (Fast). Phase 4 Silicon Sheet Growth Development for the Large Area Sheet Task of the Low-Cost Solar Array Project

    NASA Technical Reports Server (NTRS)

    Schmid, F.

    1981-01-01

    The crystallinity of large HEM silicon ingots as a function of heat flow conditions is investigated. A balanced heat flow at the bottom of the ingot restricts spurious nucleation to the edge of the melted-back seed in contact with the crucible. Homogeneous resistivity distribution over all the ingot has been achieved. The positioning of diamonds electroplated on wirepacks used to slice silicon crystals is considered. The electroplating of diamonds on only the cutting edge is described and the improved slicing performance of these wires evaluated. An economic analysis of value added costs of HEM ingot casting and band saw sectioning indicates the projected add on cost of HEM is well below the 1986 allocation.

  1. Path Crossings with Lars Onsager

    NASA Astrophysics Data System (ADS)

    Yang, Chen Ning

    2013-05-01

    I first heard of Onsager's name from my M.S. degree thesis adviser J. S. Wang in Kunming, China. Wang had studied the theory of order-disorder transitions with R. H. Fowler in Cambridge, England in the 1930's. He told me one day in 1944-45 that Onsager had produced an exact solution of the Ising model in two dimensions. Wang was a quiet and reserved person. But that day he was evidently quite excited. I can remember still today, half a century later, the tone of admiration bordering on agitation with which he told me about Onsager's paper. I then looked up the paper [26J, but did not understand the strategic plan of Onsager's method. Onsager seemed to have a predilection for calculating commutators at every possible turn without supplying the reasons for so doing...

  2. The infusion of glucose in ewes during the luteal phase increases the number of follicles but reduces oestradiol production and some correlates of metabolic function in the large follicles.

    PubMed

    Gallet, Claire; Dupont, Joëlle; Campbell, Bruce K; Monniaux, Danielle; Guillaume, Daniel; Scaramuzzi, Rex J

    2011-09-01

    Short-term nutritional supplementation stimulates folliculogenesis in ewes probably by insulin-mediated actions of glucose in the follicle. The aim of this study was to determine the effect of glucose on follicle number and granulosa levels of Aromatase P450 and phosphorylated Akt and AMPK. Twelve Ile-de-France ewes were allocated to two groups; one (n=7) infused with saline and the other (n=5) with glucose (10mM/h) for 72h in the luteal phase. At the end of infusion, ovaries were collected and all follicles >1mm in diameter were dissected to recover granulosa cells. Aromatase P450 and phosphorylated Akt and AMPK were analysed by Western blotting of granulosa cell lysates. Blood plasmas collected before and during the infusions were analysed for progesterone, oestradiol, LH, FSH, glucose, insulin and IGF-I. The infusion of glucose significantly increased follicle number but, significantly reduced Aromatase P450 and phosphorylated Akt and AMPK in granulosa cells. The circulating concentration of glucose rose significantly 3h after the start of the glucose infusion and remained elevated until 27h then fell; the circulating concentration of insulin rose significantly by 3h and remained elevated. The circulating concentration of oestradiol fell significantly by 32h and remained low; the circulating concentrations of LH and FSH were unaffected. These data show that short-term infusion of glucose stimulated follicular growth but decreased Aromatase P450 in granulosa cells. The reduced levels of phosphorylated Akt and AMPK suggest that the phosphatidylinositol 3-kinase pathway has been inhibited by high concentrations of glucose. These data also suggest that there may be functional cross-talk between FSH and insulin signalling in granulosa cells.

  3. Venus Phasing.

    ERIC Educational Resources Information Center

    Riddle, Bob

    1997-01-01

    Presents a science activity designed to introduce students to the geocentric and heliocentric models of the universe. Helps students discover why phase changes on Venus knocked Earth out of the center of the universe. (DKM)

  4. Microwave performance characterization of large space antennas

    NASA Technical Reports Server (NTRS)

    Bathker, D. A. (Editor)

    1977-01-01

    Performance capabilities of large microwave space antenna configurations with apertures generally from 100 wavelengths upwards are discussed. Types of antennas considered include: phased arrays, lenses, reflectors, and hybrid combinations of phased arrays with reflectors or lenses. The performance characteristics of these broad classes of antennas are examined and compared in terms of applications.

  5. Linear phase compressive filter

    DOEpatents

    McEwan, Thomas E.

    1995-01-01

    A phase linear filter for soliton suppression is in the form of a laddered series of stages of non-commensurate low pass filters with each low pass filter having a series coupled inductance (L) and a reverse biased, voltage dependent varactor diode, to ground which acts as a variable capacitance (C). L and C values are set to levels which correspond to a linear or conventional phase linear filter. Inductance is mapped directly from that of an equivalent nonlinear transmission line and capacitance is mapped from the linear case using a large signal equivalent of a nonlinear transmission line.

  6. Linear phase compressive filter

    DOEpatents

    McEwan, T.E.

    1995-06-06

    A phase linear filter for soliton suppression is in the form of a laddered series of stages of non-commensurate low pass filters with each low pass filter having a series coupled inductance (L) and a reverse biased, voltage dependent varactor diode, to ground which acts as a variable capacitance (C). L and C values are set to levels which correspond to a linear or conventional phase linear filter. Inductance is mapped directly from that of an equivalent nonlinear transmission line and capacitance is mapped from the linear case using a large signal equivalent of a nonlinear transmission line. 2 figs.

  7. Development of a solid-phase extraction system modified for preconcentration of emerging contaminants in large sample volumes from rivers of the lagoon system in the city of Rio de Janeiro, Brazil.

    PubMed

    Lopes, Vitor Sergio Almeida; Riente, Roselene Ribeiro; da Silva, Alexsandro Araújo; Torquilho, Delma Falcão; Carreira, Renato da Silva; Marques, Mônica Regina da Costa

    2016-09-15

    A single method modified for monitoring of emerging contaminants in river water was developed for large sample volumes. Water samples from rivers of the lagoon system in the city of Rio de Janeiro (Brazil) were analyzed by the SPE-HPLC-MS-TOF analytical method. Acetaminophen was detected in four rivers in the concentration range of 0.09μgL(-1) to 0.14μgL(-1). Salicylic acid was also found in the four rivers in the concentration range of 1.65μgL(-1) to 4.81μgL(-1). Bisphenol-A was detected in all rivers in the concentration range of 1.37μgL(-1) to 39.86μgL(-1). Diclofenac was found in only one river, with concentration of 0.22μgL(-1). The levels of emerging organic pollutants in the water samples of the Jacarepaguá hydrographical basin are significant. The compounds are not routinely monitored and present potential risks to environmental health.

  8. Large Capacity Missile Carrier (CMX)

    DTIC Science & Technology

    1993-12-01

    is examined. It is included that the benefits of the large number of additional missiles provided by the CMX more than offsets the lost capability of...project was to exercise the ship design process from the requirements setting phase through the preliminary design, including design analysis. The...Navy to meet the challenges ensuing from this assumed global scenario. The Student Design Team was tasked to develop scenarios for the deployment of the

  9. Clinical and genomic analysis of a randomised phase II study evaluating anastrozole and fulvestrant in postmenopausal patients treated for large operable or locally advanced hormone-receptor-positive breast cancer

    PubMed Central

    Quenel-Tueux, Nathalie; Debled, Marc; Rudewicz, Justine; MacGrogan, Gaetan; Pulido, Marina; Mauriac, Louis; Dalenc, Florence; Bachelot, Thomas; Lortal, Barbara; Breton-Callu, Christelle; Madranges, Nicolas; de Lara, Christine Tunon; Fournier, Marion; Bonnefoi, Hervé; Soueidan, Hayssam; Nikolski, Macha; Gros, Audrey; Daly, Catherine; Wood, Henry; Rabbitts, Pamela; Iggo, Richard

    2015-01-01

    Background: The aim of this study was to assess the efficacy of neoadjuvant anastrozole and fulvestrant treatment of large operable or locally advanced hormone-receptor-positive breast cancer not eligible for initial breast-conserving surgery, and to identify genomic changes occurring after treatment. Methods: One hundred and twenty post-menopausal patients were randomised to receive 1 mg anastrozole (61 patients) or 500 mg fulvestrant (59 patients) for 6 months. Genomic DNA copy number profiles were generated for a subgroup of 20 patients before and after treatment. Results: A total of 108 patients were evaluable for efficacy and 118 for toxicity. The objective response rate determined by clinical palpation was 58.9% (95% CI=45.0–71.9) in the anastrozole arm and 53.8% (95% CI=39.5–67.8) in the fulvestrant arm. The breast-conserving surgery rate was 58.9% (95% CI=45.0–71.9) in the anastrozole arm and 50.0% (95% CI=35.8–64.2) in the fulvestrant arm. Pathological responses >50% occurred in 24 patients (42.9%) in the anastrozole arm and 13 (25.0%) in the fulvestrant arm. The Ki-67 score fell after treatment but there was no significant difference between the reduction in the two arms (anastrozole 16.7% (95% CI=13.3–21.0) before, 3.2% (95% CI=1.9–5.5) after, n=43; fulvestrant 17.1% (95%CI=13.1–22.5) before, 3.2% (95% CI=1.8–5.7) after, n=38) or between the reduction in Ki-67 in clinical responders and non-responders. Genomic analysis appeared to show a reduction of clonal diversity following treatment with selection of some clones with simpler copy number profiles. Conclusions: Both anastrozole and fulvestrant were effective and well-tolerated, enabling breast-conserving surgery in over 50% of patients. Clonal changes consistent with clonal selection by the treatment were seen in a subgroup of patients. PMID:26171933

  10. Solid phase extraction membrane

    DOEpatents

    Carlson, Kurt C [Nashville, TN; Langer, Roger L [Hudson, WI

    2002-11-05

    A wet-laid, porous solid phase extraction sheet material that contains both active particles and binder and that possesses excellent wet strength is described. The binder is present in a relatively small amount while the particles are present in a relatively large amount. The sheet material is sufficiently strong and flexible so as to be pleatable so that, for example, it can be used in a cartridge device.

  11. The large binocular telescope.

    PubMed

    Hill, John M

    2010-06-01

    The Large Binocular Telescope (LBT) Observatory is a collaboration among institutions in Arizona, Germany, Italy, Indiana, Minnesota, Ohio, and Virginia. The telescope on Mount Graham in Southeastern Arizona uses two 8.4 m diameter primary mirrors mounted side by side. A unique feature of the LBT is that the light from the two Gregorian telescope sides can be combined to produce phased-array imaging of an extended field. This cophased imaging along with adaptive optics gives the telescope the diffraction-limited resolution of a 22.65 m aperture and a collecting area equivalent to an 11.8 m circular aperture. This paper describes the design, construction, and commissioning of this unique telescope. We report some sample astronomical results with the prime focus cameras. We comment on some of the technical challenges and solutions. The telescope uses two F/15 adaptive secondaries to correct atmospheric turbulence. The first of these adaptive mirrors has completed final system testing in Firenze, Italy, and is planned to be at the telescope by Spring 2010.

  12. Direct Measurement of Large, Diffuse, Optical Structures

    NASA Technical Reports Server (NTRS)

    Saif, Babak N.; Keski-Kuha, Ritva; Feinberg, Lee; Wyant, J. C.; Atkinson, C.

    2004-01-01

    Digital Speckle Pattern Interferometry (DSPI) is a well-established method for the measurement of diffuse objects in experimental mechanics. DSPIs are phase shifting interferometers. Three or four bucket temporal phase shifting algorithms are commonly used to provide phase shifting. These algorithms are sensitive to vibrations and can not be used to measure large optical structures far away from the interferometer. In this research a simultaneous phase shifted interferometer, PhaseCam product of 4D Technology Corporation in Tucson Arizona, is modified to be a Simultaneous phase shifted Digital Speckle Pattern Interferometer (SDSPI). Repeatability, dynamic range, and accuracy of the SDSPI are characterized by measuring a 5 cm x 5 cm carbon fiber coupon.

  13. Alternative Training Agents Phase 4. Large-Scale Tests

    DTIC Science & Technology

    1992-02-01

    20 BLEND BY MOLES OF 2,2-DICHLORO-1,1,1-TRIFLUOROETHANE AND 1-CHLORO-1,1- DIFLUOROETHANE , BOTH TECHNICAL GRADES)** 1.0 SCOPE 1.1 This specification...pure 1-chloro- 1,1- difluoroethane , suitable as a fire extinguishing fluid for firefighter training and shall conform to the requirements of Table B-1...percent by moles 1-Chloro-1,l- difluoroethane 20.0 ± 1 4.4.1 percent by moles Boiling Point, degrees Celsius -10 to +28 4.4.2 at 760 mm Hg (14 to 82 ’F

  14. Blade technology program for large wind turbines, phase 1

    NASA Astrophysics Data System (ADS)

    Muser, D.

    1984-10-01

    A research program for the development and construction of rotor blades is presented. The project includes investigation and design of blade concepts, compilation of materials properties of fiber reinforced plastics, and manufacturing and testing of critical blade sections. The following parts are produced and tested to check the manufacturing technology: element for load introduction, shell section in sandwich-spar technology, filament-wound D-spar in carbon fiber reinforced epoxy, and filament-wound D-spar with rear profile box in tube-winding technology. It is shown that the carbon and glass fiber reinforced plastics blade with wound D-spar is optimum. This blade has the lowest mass that can be economically manufactured by automatic filament winding.

  15. Large block migration experiments: INTRAVAL phase 1, Test Case 9

    SciTech Connect

    Gureghian, A.B.; Noronha, C.J. . Office of Waste Technology Development); Vandergraaf, T.T. )

    1990-08-01

    The development of INTRAVAL Test Case 9, as presented in this report, was made possible by a past subsidiary agreement to the bilateral cooperative agreement between the US Department of Energy (DOE) and Atomic Energy of Canada Limited (AECL) encompassing various aspects of nuclear waste disposal research. The experimental aspect of this test case, which included a series of laboratory experiments designed to quantify the migration of tracers in a single, natural fracture, was undertaken by AECL. The numerical simulation of the results of these experiments was performed by the Battelle Office of Waste Technology Development (OWTD) by calibrating an in-house analytical code, FRACFLO, which is capable of predicting radionuclide transport in an idealized fractured rock. Three tracer migration experiments were performed, using nonsorbing uranine dye for two of them and sorbing Cs-137 for the third. In addition, separate batch experiments were performed to determine the fracture surface and rock matrix sorption coefficients for Cs-137. The two uranine tracer migration experiment were used to calculate the average fracture aperture and to calibrate the model for the fracture dispersivity and matrix diffusion coefficient. The predictive capability of the model was then tested by simulating the third, Cs-137, tracer test without changing the parameter values determined from the other experiments. Breakthrough curves of both the experimental and numerical results obtained at the outlet face of the fracture are presented for each experiment. The reported spatial concentration profiles for the rock matrix are based solely on numerical predictions. 22 refs., 12 figs., 8 tabs.

  16. Validating Phasing and Geometry of Large Focal Plane Arrays

    NASA Technical Reports Server (NTRS)

    Standley, Shaun P.; Gautier, Thomas N.; Caldwell, Douglas A.; Rabbette, Maura

    2011-01-01

    The Kepler Mission is designed to survey our region of the Milky Way galaxy to discover hundreds of Earth-sized and smaller planets in or near the habitable zone. The Kepler photometer is an array of 42 CCDs (charge-coupled devices) in the focal plane of a 95-cm Schmidt camera onboard the Kepler spacecraft. Each 50x25-mm CCD has 2,200 x 1,024 pixels. The CCDs accumulate photons and are read out every six seconds to prevent saturation. The data is integrated for 30 minutes, and then the pixel data is transferred to onboard storage. The data is subsequently encoded and transmitted to the ground. During End-to-End Information System (EEIS) testing of the Kepler Mission System (KMS), there was a need to verify that the pixels requested by the science team operationally were correctly collected, encoded, compressed, stored, and transmitted by the FS, and subsequently received, decoded, uncompressed, and displayed by the Ground Segment (GS) without the outputs of any CCD modules being flipped, mirrored, or otherwise corrupted during the extensive FS and GS processing. This would normally be done by projecting an image on the focal plane array (FPA), collecting the data in a flight-like way, and making a comparison between the original data and the data reconstructed by the science data system. Projecting a focused image onto the FPA through the telescope would normally involve using a collimator suspended over the telescope opening. There were several problems with this approach: the collimation equipment is elaborate and expensive; as conceived, it could only illuminate a limited section of the FPA (.25 percent) during a given test; the telescope cover would have to be deployed during testing to allow the image to be projected into the telescope; the equipment was bulky and difficult to situate in temperature-controlled environments; and given all the above, test setup, execution, and repeatability were significant concerns. Instead of using this complicated approach of projecting an optical image on the FPA, the Kepler project developed a method using known defect features in the CCDs to verify proper collection and reassembly of the pixels, thereby avoiding the costs and risks of the optical projection approach. The CCDs composing the Kepler FPA, as all CCDs, had minor defects. At ambient temperature, some pixels look far brighter than they should. These ghot h pixels have a higher rate of charge leakage than the others due to manufacturing variations. They are usually stable over time, and appear at temperatures above 5 oC. The hot pixels on the Kepler FPA were mapped before photometer assembly during module testing. Selected hot pixels were used as target gstars h for the purposes of EEIS testing. gDead h pixels are permanently off, producing a permanently black pixel. These can also be used if there is some illumination of the FPA. During EEIS testing, Dark Current Full Frame Images (FFIs) taken at room temperature were used to create the hot pixel maps for all 84 Kepler photometer CCD channels. Data from two separate nights were used to create two hot pixel maps per channel, which were cross-correlated to remove cosmic ray events which appear to be hot pixels. These hot pixel maps obtained during EEIS testing were compared to the maps made during module testing to verify that the end-to-end data flow was correct.

  17. Large amplitude relativistic plasma waves

    SciTech Connect

    Coffey, Timothy

    2010-05-15

    Relativistic, longitudinal plasma oscillations are studied for the case of a simple water bag distribution of electrons having cylindrical symmetry in momentum space with the axis of the cylinder parallel to the velocity of wave propagation. The plasma is required to obey the relativistic Vlasov-Poisson equations, and solutions are sought in the wave frame. An exact solution for the plasma density as a function of the electrostatic field is derived. The maximum electric field is presented in terms of an integral over the known density. It is shown that when the perpendicular momentum is neglected, the maximum electric field approaches infinity as the wave phase velocity approaches the speed of light. It is also shown that for any nonzero perpendicular momentum, the maximum electric field will remain finite as the wave phase velocity approaches the speed of light. The relationship to previously published solutions is discussed as is some recent controversy regarding the proper modeling of large amplitude relativistic plasma waves.

  18. Adaptive Optics for Large Telescopes

    SciTech Connect

    Olivier, S

    2008-06-27

    The use of adaptive optics was originally conceived by astronomers seeking to correct the blurring of images made with large telescopes due to the effects of atmospheric turbulence. The basic idea is to use a device, a wave front corrector, to adjust the phase of light passing through an optical system, based on some measurement of the spatial variation of the phase transverse to the light propagation direction, using a wave front sensor. Although the original concept was intended for application to astronomical imaging, the technique can be more generally applied. For instance, adaptive optics systems have been used for several decades to correct for aberrations in high-power laser systems. At Lawrence Livermore National Laboratory (LLNL), the world's largest laser system, the National Ignition Facility, uses adaptive optics to correct for aberrations in each of the 192 beams, all of which must be precisely focused on a millimeter scale target in order to perform nuclear physics experiments.

  19. Instantons and Large N

    NASA Astrophysics Data System (ADS)

    Mariño, Marcos

    2015-09-01

    Preface; Part I. Instantons: 1. Instantons in quantum mechanics; 2. Unstable vacua in quantum field theory; 3. Large order behavior and Borel summability; 4. Non-perturbative aspects of Yang-Mills theories; 5. Instantons and fermions; Part II. Large N: 6. Sigma models at large N; 7. The 1=N expansion in QCD; 8. Matrix models and matrix quantum mechanics at large N; 9. Large N QCD in two dimensions; 10. Instantons at large N; Appendix A. Harmonic analysis on S3; Appendix B. Heat kernel and zeta functions; Appendix C. Effective action for large N sigma models; References; Author index; Subject index.

  20. Electroweak phase transitions

    SciTech Connect

    Anderson, G.W.

    1991-09-16

    An analytic treatment of the one Higgs doublet, electroweak phase transition is given. The phase transition is first order, occurs by the nucleation of thin walled bubbles and completes at a temperature where the order parameter, {l_angle}{phi}{r_angle}{sub T} is significantly smaller than it is when the origin becomes absolutely unstable. The rate of anomalous baryon number violation is an exponentially function of {l_angle}{phi}{r_angle}{sub T}. In very minimal extensions of the standard model it is quite easy to increase {l_angle}{phi}{r_angle}{sub T} so that anomalous baryon number violation is suppressed after completion of the phase transition. Hence baryogenesis at the electroweak phase transition is tenable in minimal of the standard model. In some cases additional phase transitions are possible. For a light Higgs boson, when the top quark mass is sufficiently large, the state where the Higgs field has a vacuum expectation value {l_angle}{phi}{r_angle} = 246 GeV is not the true minimum of the Higgs potential. When this is the case, and when the top quark mass exceeds some critical value, thermal fluctuations in the early universe would have rendered the state {l_angle}{phi}{r_angle} = 246 GeV unstable. The requirement that the state {l_angle}{phi}{r_angle} = 246 GeV is sufficiently long lived constrains the masses of the Higgs boson and the top quark. Finally, we consider whether local phase transitions can be induced by heavy particles which act as seeds for deformations in the scalar field.