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Sample records for phase lar large

  1. First operation and drift field performance of a large area double phase LAr Electron Multiplier Time Projection Chamber with an immersed Greinacher high-voltage multiplier

    NASA Astrophysics Data System (ADS)

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

    2012-08-01

    We have operated a liquid-argon large-electron-multiplier time-projection chamber (LAr LEM-TPC) with a large active area of 76 × 40 cm2 and a drift length of 60 cm. This setup represents the largest chamber ever achieved with this novel detector concept. The chamber is equipped with an immersed built-in cryogenic Greinacher multi-stage high-voltage (HV) multiplier, which, when subjected to an external AC HV of ~ 1 kVpp, statically charges up to a voltage a factor of ~ 30 higher inside the LAr vessel, creating a uniform drift field of ~ 0.5 kV/cm over the full drift length. This large LAr LEM-TPC was brought into successful operation in the double-phase (liquid-vapor) operation mode and tested during a period of ~ 1 month, recording impressive three-dimensional images of very high-quality from cosmic particles traversing or interacting in the sensitive volume. The double phase readout and HV systems achieved stable operation in cryogenic conditions demonstrating their good characteristics, which particularly suit applications for next-generation giant-scale LAr-TPCs.

  2. 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.

  3. Upgraded readout electronics for the ATLAS LAr calorimeter at the phase I of LHC

    NASA Astrophysics Data System (ADS)

    Stärz, S.; Atlas Liquid Argon Calorimeter Group

    2013-08-01

    The ATLAS Liquid Argon (LAr) calorimeters produce a total of 182,486 signals which are digitized and processed by the front-end and back-end electronics at every triggered event. In addition, the front-end electronics is summing analog signals to provide coarsely grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. However, the pile-up noise expected during the high luminosity phases of LHC will be increased by factors of 3-7. An improved spatial granularity of the trigger primitives is therefore proposed in order to improve the identification performance for trigger signatures, like electrons or photons, at high background rejection rates. The general concept of the upgraded LAr calorimeter readout together with the various electronics components to be developed for such a complex system is presented. The R&D activities and architectural studies undertaken by the ATLAS LAr Calorimeter group are described.

  4. 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.

  5. 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

  6. Pharmacokinetics, pharmacodynamics, and safety of pasireotide LAR in patients with acromegaly: a randomized, multicenter, open-label, phase I study.

    PubMed

    Petersenn, Stephan; Bollerslev, Jens; Arafat, Ayman M; Schopohl, Jochen; Serri, Omar; Katznelson, Laurence; Lasher, Janet; Hughes, Gareth; Hu, Ke; Shen, George; Reséndiz, Karina Hermosillo; Giannone, Vanessa; Beckers, Albert

    2014-11-01

    Pasireotide (SOM230), a multireceptor-targeted somatostatin analogue, has exhibited favorable safety/tolerability in several clinical studies. A long-acting-release (LAR) formulation of pasireotide may offer advantages over the subcutaneous formulation. This randomized, open-label, Phase I study evaluated the safety, PK, and PD of pasireotide LAR 20, 40, or 60 mg/month in patients with acromegaly. Safety assessments and blood samples for PK and PD were taken at designated time points. Thirty-five patients were randomized and completed the study. Steady-state pasireotide concentrations were achieved following three monthly injections. Trough pasireotide concentrations (ng/mL) 28 days after each injection were: 2.48, 4.16, and 3.10 (20 mg group); 6.42, 6.62, and 7.12 (40 mg group); and 9.51, 11.7, and 13.0 (60 mg group). At study end, 51% and 57% of patients achieved GH levels ≤2.5 μg/L and IGF-1 levels below ULN, respectively. Compared with baseline, fasting blood glucose and HbA1c levels increased, whereas fasting blood insulin levels decreased. Acromegaly symptoms were generally improved. Adverse events were mostly gastrointestinal and mild/moderate. Pasireotide LAR was generally well tolerated. Steady-state PK was achieved after three monthly doses; exposures were approximately dose proportional. Control of GH, IGF-1, and symptoms improved, suggesting that pasireotide LAR may be an effective treatment for acromegaly.

  7. 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.

  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.

    2016-03-01

    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. 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.

  10. 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.

  11. 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.

  12. Solar neutrino detection in a large volume double-phase liquid argon experiment

    NASA Astrophysics Data System (ADS)

    Franco, D.; Giganti, C.; Agnes, P.; Agostino, L.; Bottino, B.; Canci, N.; Davini, S.; De Cecco, S.; Fan, A.; Fiorillo, G.; Galbiati, C.; Goretti, A. M.; Hungerford, E. V.; Ianni, Al.; Ianni, An.; Jollet, C.; Marini, L.; Martoff, C. J.; Meregaglia, A.; Pagani, L.; Pallavicini, M.; Pantic, E.; Pocar, A.; Razeti, M.; Renshaw, A. L.; Rossi, B.; Rossi, N.; Suvorov, Y.; Testera, G.; Tonazzo, A.; Wang, H.; Zavatarelli, S.

    2016-08-01

    Precision measurements of solar neutrinos emitted by specific nuclear reaction chains in the Sun are of great interest for developing an improved understanding of star formation and evolution. Given the expected neutrino fluxes and known detection reactions, such measurements require detectors capable of collecting neutrino-electron scattering data in exposures on the order of 1 ktonne-yr, with good energy resolution and extremely low background. Two-phase liquid argon time projection chambers (LAr TPCs) are under development for direct Dark Matter WIMP searches, which possess very large sensitive mass, high scintillation light yield, good energy resolution, and good spatial resolution in all three cartesian directions. While enabling Dark Matter searches with sensitivity extending to the ``neutrino floor'' (given by the rate of nuclear recoil events from solar neutrino coherent scattering), such detectors could also enable precision measurements of solar neutrino fluxes using the neutrino-electron elastic scattering events. Modeling results are presented for the cosmogenic and radiogenic backgrounds affecting solar neutrino detection in a 300 tonne (100 tonne fiducial) LAr TPC operating at LNGS depth (3,800 meters of water equivalent). The results show that such a detector could measure the CNO neutrino rate with ~15% precision, and significantly improve the precision of the 7Be and pep neutrino rates compared to the currently available results from the Borexino organic liquid scintillator detector.

  13. Photorefractive processing for large adaptive phased arrays.

    PubMed

    Weverka, R T; Wagner, K; Sarto, A

    1996-03-10

    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.

  14. 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

  15. 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.

  16. Octreotide LAR and tamoxifen versus tamoxifen in phase III randomize early breast cancer trials: NCIC CTG MA.14 and NSABP B-29.

    PubMed

    Chapman, Judith-Anne W; Costantino, Joseph P; Dong, Bin; Margolese, Richard G; Pritchard, Kathleen I; Shepherd, Lois E; Gelmon, Karen A; Wolmark, Norman; Pollak, Michael N

    2015-09-01

    NCIC CTG MA.14 and NSABP B-29 trials examined the addition of Octreotide LAR (OCT) to 5 years of tamoxifen (TAM). Gallbladder toxicity led to B-29 discontinuation of OCT, and MA.14 OCT administration shortened to 2 years. Median follow-up was 9.8 years for 667 MA.14 patients and 6.8 years for 893 B-29 patients. The primary endpoint was disease-free survival (DFS), defined as time from randomization to time of breast cancer recurrence; second primary cancer other than squamous or basal cell skin carcinoma, cervical carcinoma in situ, or lobular breast carcinoma in situ; or death. The primary statistical test was a univariable pooled stratified log-rank test; multivariable assessment was with Cox regression. For MA.14, 97% of patients were ≥50 years; for B-29, 62%. MA.14 patients were 53% lymph node negative (LN-) while B-29 were 100% LN-; 33% of MA.14 patients received adjuvant chemotherapy, 2% concurrently, while B-29 had 53% concurrent chemotherapy. MA.14 patients were 90% hormone receptor positive; B-29, 100%. MA.14 patients experienced 5-year DFS of 80% with TAM, 76% with TAM + OCT; B-29 patients had 5-year DFS of 88% for both arms. Pooled univariable TAM + OCT to TAM hazard ratio (HR) was 0.99 (95% CI 0.81-1.20; p = 0.69): for MA.14, HR = 0.94 (0.73-1.20; p = 0.50); for B-29, HR = 1.09 (0.80-1.50; p = 0.59). Multivariable pooled HR = 0.98 (0.81-1.20; p = 0.84). Older patients (p < 0.001), with higher T stage (p < 0.001), and LN + (p < 0.001) had shorter DFS. Addition of OCT to TAM did not significantly improve DFS; gallbladder toxicity shortened the additional administration of OCT. This does not negate targeting the insulin-IGF-I receptor family with less toxic therapeutics.

  17. Octreotide LAR and tamoxifen versus tamoxifen in phase III randomize early breast cancer trials: NCIC CTG MA.14 and NSABP B-29

    PubMed Central

    Costantino, Joseph P.; Dong, Bin; Margolese, Richard G.; Pritchard, Kathleen I.; Shepherd, Lois E.; Gelmon, Karen A.; Wolmark, Norman; Pollak, Michael N.

    2015-01-01

    NCIC CTG MA.14 and NSABP B-29 trials examined the addition of Octreotide LAR (OCT) to 5 years of tamoxifen (TAM). Gallbladder toxicity led to B-29 discontinuation of OCT, and MA.14 OCT administration shortened to 2 years. Median follow-up was 9.8 years for 667 MA.14 patients and 6.8 years for 893 B-29 patients. The primary endpoint was disease-free survival (DFS), defined as time from randomization to time of breast cancer recurrence; second primary cancer other than squamous or basal cell skin carcinoma, cervical carcinoma in situ, or lobular breast carcinoma in situ; or death. The primary statistical test was a univariable pooled stratified log-rank test; multivariable assessment was with Cox regression. For MA.14, 97 % of patients were ≥50 years; for B-29, 62 %. MA.14 patients were 53 % lymph node negative (LN–) while B-29 were 100 % LN–; 33 % of MA.14 patients received adjuvant chemotherapy, 2 % concurrently, while B-29 had 53 % concurrent chemotherapy. MA.14 patients were 90% hormone receptor positive; B-29, 100 %. MA.14 patients experienced 5-year DFS of 80 % with TAM, 76 % with TAM + OCT; B-29 patients had 5-year DFS of 88 % for both arms. Pooled univariable TAM + OCT to TAM hazard ratio (HR) was 0.99 (95% CI 0.81–1.20; p = 0.69): for MA.14, HR = 0.94 (0.73–1.20; p = 0.50); for B-29, HR = 1.09 (0.80–1.50; p = 0.59). Multivariable pooled HR = 0.98 (0.81–1.20; p = 0.84). Older patients (p < 0.001), with higher T stage (p < 0.001), and LN + (p < 0.001) had shorter DFS. Addition of OCT to TAM did not significantly improve DFS; gallbladder toxicity shortened the additional administration of OCT. This does not negate targeting the insulin–IGF-I receptor family with less toxic therapeutics. PMID:26276354

  18. 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.

  19. 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.

  20. Evaluation of the Effects of Pasireotide LAR Administration on Lymphocele Prevention after Axillary Node Dissection for Breast Cancer: Results of a Randomized Non-Comparative Phase 2 Study

    PubMed Central

    Chéreau, Elisabeth; Uzan, Catherine; Boutmy-Deslandes, Emmanuelle; Zohar, Sarah; Bézu, Corinne; Mazouni, Chafika; Garbay, Jean-Rémi; Daraï, Emile; Rouzier, Roman

    2016-01-01

    Objective The aim of this study was to assess the efficacy (response rate centered on 80%) of a somatostatin analog with high affinity for 4 somatostatin receptors in reducing the postoperative incidence of symptomatic lymphocele formation following total mastectomy with axillary lymph node dissection. Setting This prospective, double-blind, randomised, placebo-controlled, phase 2 trial was conducted in two secondary care centres. Participants All female patients for whom mastectomy and axillary lymph node dissection were indicated were eligible for the study, including patients who had received neo-adjuvant chemotherapy. Main exclusion criteria were related to diabetes, cardiac insufficiency, disorder of cardiac conduction or hepatic failure. Interventions Patients were randomised to receive one injection of either prolonged-release pasireotide 60 mg or placebo (physiological serum), which were administered intramuscularly 7 to 10 days before the scheduled surgery. The study was conducted in a double-blind manner. Primary and Secondary Outcome Measures The primary outcome measure was the percentage of patients who did not develop post-operative axillary symptomatic lymphoceles during the 2 postoperative months. Secondary endpoints were the total quantity of lymph drained, duration and daily volume of drainage and aspirated volumes of lymph. Results Ninety-one patients were randomised. Ninety patients were evaluable: 42 patients received pasireotide, and 48 patients received placebo. The mean estimated response rate were 62.4% (95% Credibility Interval [CrI]: 48.6%-75.3%) in the treatment group and 50.2% (95% CrI: 37.6%-62.8%) in the placebo group. Overall safety was comparable across groups, and one serious adverse event occurred. In the treatment group, one patient with known insulin-depe*ndent diabetes required hospitalization for hyperglycaemia. Conclusions With this phase 2 preliminary study, even if our results indicate a trend towards a reduction in

  1. The LArIAT Experiment at Fermilab

    NASA Astrophysics Data System (ADS)

    Nutini, Irene; LArIAT Collaboration

    2016-02-01

    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 1 st Run are being analyzed for both Physics studies and a technical characterization of the scintillation light collection system. 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.

  2. Management of Hyperglycemia in Patients With Acromegaly Treated With Pasireotide LAR.

    PubMed

    Samson, Susan L

    2016-09-01

    Pasireotide (Signifor(®)) long-acting release (LAR) is a next-generation somatostatin receptor ligand (SRL) approved for treatment of patients with acromegaly who have had an inadequate response to surgery or for whom surgery is not an option. Pasireotide LAR has been shown to be more effective than other SRLs in providing biochemical control in patients with acromegaly. However, hyperglycemia-related adverse events were more frequent in patients treated with pasireotide LAR than in those treated with other SRLs. Given the effectiveness of pasireotide LAR, it is important to understand whether these hyperglycemia-related events are manageable and, if so, the appropriate steps to take to manage them. In patients treated with pasireotide LAR, levels of fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) increased in the first 1-3 months and stabilized for as long as 26 months thereafter. In phase III trials of patients with acromegaly, only 3.4-3.8 % discontinued pasireotide LAR because of hyperglycemia-related adverse events. In cases in which pasireotide LAR was discontinued, FPG and HbA1c levels returned to baseline. Frequent monitoring of glucose levels is recommended, especially immediately after initiating and discontinuing pasireotide LAR. The treatment strategies suggested herein are made on the basis of available clinical data from healthy volunteers and post hoc analyses of phase III trials. Data from several clinical trials indicate a predictable and possibly reversible hyperglycemic effect that is manageable with proactive monitoring and available antidiabetic medications. PMID:27473537

  3. Large conditional single-photon cross-phase modulation

    NASA Astrophysics Data System (ADS)

    Beck, Kristin; Hosseini, Mahdi; Duan, Yiheng; Vuletic, Vladan

    2016-05-01

    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 up to π / 3 between the retrieved signal and control photons, and confirm deterministic entanglement between the signal and control modes by extracting a positive concurrence. With a moderate improvement in cavity finesse, our system can reach a coherent phase shift of p at low loss, enabling deterministic and universal photonic quantum logic. Preprint: arXiv:1512.02166 [quant-ph

  4. Large conditional single-photon cross-phase modulation.

    PubMed

    Beck, Kristin M; Hosseini, Mahdi; Duan, Yiheng; Vuletić, Vladan

    2016-08-30

    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 [Formula: see text] (and up to [Formula: see text] 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.

  5. Large conditional single-photon cross-phase modulation.

    PubMed

    Beck, Kristin M; Hosseini, Mahdi; Duan, Yiheng; Vuletić, Vladan

    2016-08-30

    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 [Formula: see text] (and up to [Formula: see text] 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

  6. 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.

  7. 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.

  8. Liquor Activity Reduction (LAR) Programme - 12397

    SciTech Connect

    Pether, Colin; Carrol, Phil; Birkett, Eddie; Kibble, Matthew

    2012-07-01

    Waste material from the reprocessing of irradiated fuel has been stored under water for several decades leading to the water becoming highly radioactive. As a critical enabler to the decommissioning strategy for the Sellafield site, the Liquor Activity Reduction (LAR) programme has been established to provide a processing route for this highly radioactive liquor. This paper reviews the progress that has been made since the start of routine LAR transfer cycles (July 2010) and follows on from the earlier paper presented at WM2011. The paper focuses on the learning from the first full year of routine LAR transfer cycles and the application of this learning to the wider strategies for the treatment of further radioactive liquid effluents on the Sellafield site. During this period over 100,000 Curies of radioactivity has been safely removed and treated. The past year has witnessed the very successful introduction of the LAR programme. This has lead to hazard reduction at MSSS and demonstration that the SIXEP facility can meet the significantly increased challenge that the LAR programme represents. Part of the success has been the ability to predict and deliver a realistic production schedule with the availability of the MSSS, EDT and SIXEP facilities being central to this. Most importantly, the LAR programme has been successful in bringing together key stakeholders to deliver this work while integrating with the existing, day to day, demands of the Sellafield site. (authors)

  9. 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.

  10. Large resistivity modulation in mixed-phase metallic systems.

    PubMed

    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. PMID:25564764

  11. Large cross phase modulation using double electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Wang, Zeng-Bin

    This thesis deals with the engineering of accumulated cross-phase modulation (XPM) cross phase shifts (XPS) between two weak pulses based on large coherent nonlinear interaction enhanced by a medium that exhibits Electromagnetically Induced Transparency (EIT). Applications of such nonlinear phase shifts in optical quantum information processing (OQIP) are also investigated. I present a novel theoretical model to generate large XPM coefficients between two pulses while simultaneously creating Double Electromagnetically Induced Transparency (DEIT) for both signals so that detrimental effects such as absorption and distortion are significantly suppressed, leading to a large accumulated XPM XPS with near-zero absorption. Analytical solutions are derived to demonstrate the dominant physical processes. These solutions are based on analytical methods that use perturbation theory under adiabatic conditions. I also produce accurate solutions by numerically simulating the master equation and the one dimensional paraxial equation. I show how to implement this promising scheme with the D1 line of 87Rb atomic gas by applying a static magnetic field with moderate intensity. This magnetic field perturbs the atom levels according to the nonlinear Zeeman effect and thus the perturbed atomic levels provide the atomic configuration needed for this scheme. A tripod configuration inherent to the D1 line is used to create DEIT for both signals and thus allows one to slow down both signals and to flexibly manipulate the group velocities of both. I numerically simulate the master equation for this 16-level system and find a good agreement with the simplified 5-level N-Tripod system. I also investigate applications of such large XPM in OQIP. As shown in current Controlled-Phase gate (CPHASE gate) proposals based on XPS, the phase shift caused by XPM for pulses having matched group velocities would have a similar profile with the pulse shape of the single-photon pulse, which precludes a

  12. 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.

  13. Polar Phase of One-dimensional Bosons with Large Spin

    SciTech Connect

    Tsvelik, A.M.; Shlyapnikov, G.

    2011-06-20

    Spinor ultracold gases in one dimension (1D) represent an interesting example of strongly correlated quantum fluids. They have a rich phase diagram and exhibit a variety of quantum phase transitions. We consider a 1D spinor gas of bosons with a large spin S. A particular example is the gas of chromium atoms (S = 3), where the dipolar collisions efficiently change the magnetization and make the system sensitive to the linear Zeeman effect. We argue that in 1D the most interesting effects come from the pairing interaction. If this interaction is negative, it gives rise to a (quasi)condensate of singlet bosonic pairs with an algebraic order at zero temperature, and for (2S+1) >> 1 the saddle point approximation leads to physically transparent results. Since in 1D one needs a finite energy to destroy a pair, the spectrum of spin excitations has a gap. Hence, in the absence of a magnetic field, there is only one gapless mode corresponding to phase fluctuations of the pair quasicondensate. Once the magnetic field exceeds the gap, another condensate emerges, namely the quasicondensate of unpaired bosons with spins aligned along the magnetic field. The spectrum then contains two gapless modes corresponding to the singlet-paired and spin-aligned unpaired Bose condensed particles, respectively. At T = 0, the corresponding phase transition is of the commensurate-incommensurate type.

  14. Large conditional single-photon cross-phase modulation

    NASA Astrophysics Data System (ADS)

    Beck, Kristin M.; Hosseini, Mahdi; Duan, Yiheng; Vuletić, Vladan

    2016-08-01

    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/6π/6 (and up to π/3π/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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. The liquid annular reactor system (LARS) propulsion

    SciTech Connect

    Maise, G.; Lazareth, O.W.; Horn, F.; Powell, J.R.; Ludewig, H. ); Lenard, R.X. )

    1991-01-05

    A new concept for very high specific impulse ({gt}2000 seconds) direct nuclear propulsion is described. The concept, termed LARS (Liquid Annular Reactor System) uses liquid nuclear fuel elements to heat hydrogen propellant to very high temperatures ({similar to}6000 K). Operating pressure is moderate ({similar to}10 atm), with the result that the outlet hydrogen is virtually 100% dissociated to monatomic H. The molten fuel is contained in a solid container of its own material, which is rotated to stabilize the liquid layer by centripetal force. LARS reactor designs are described, together with neutronic and thermal-hydraulic analyses. Power levels are on the order of 200 megawatts. Typically, LARS designs use 7 rotating fuel elements, are beryllium moderated and have critical radii of {similar to}100 cm (core L/D{approx}1.5).

  20. The Liquid Annular Reactor System (LARS) propulsion

    NASA Technical Reports Server (NTRS)

    Powell, James; Ludewig, Hans; Horn, Frederick; Lenard, Roger

    1990-01-01

    A concept for very high specific impulse (greater than 2000 seconds) direct nuclear propulsion is described. The concept, termed the liquid annular reactor system (LARS), uses liquid nuclear fuel elements to heat hydrogen propellant to very high temperatures (approximately 6000 K). Operating pressure is moderate (approximately 10 atm), with the result that the outlet hydrogen is virtually 100 percent dissociated to monatomic H. The molten fuel is contained in a solid container of its own material, which is rotated to stabilize the liquid layer by centripetal force. LARS reactor designs are described, together with neutronic and thermal-hydraulic analyses. Power levels are on the order of 200 megawatts. Typically, LARS designs use seven rotating fuel elements, are beryllium moderated, and have critical radii of approximately 100 cm (core L/D approximately equal to 1.5).

  1. 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

  2. Sandostatin LAR (microencapsulated octreotide acetate) in acromegaly: pharmacokinetic and pharmacodynamic relationships.

    PubMed

    Grass, P; Marbach, P; Bruns, C; Lancranjan, I

    1996-08-01

    Double-blind, single-dose studies of 120 acromegalic patients given 10, 20, and 30 mg Sandostatin LAR (Sandoz Pharma Ltd, Basel, Switzerland) established the drug's pharmacokinetic profile. Patients then entered open-labeled extension phases, with Sandostatin LAR intramuscular (IM) injections every 4 weeks. These produced broadly constant octreotide concentrations with dose proportionality. Area fluctuations were minimal. Steady-state conditions were generally reached after the second to third injection. There was no evidence of downregulation with Sandostatin LAR over 1 year of study. Based on the pharmacokinetic/pharmacodynamic relationship of octreotide, a starting dose of 20 mg Sandostatin LAR and administrations every 4 weeks provide growth hormone (GH) control comparable to the thrice-daily subcutaneous (SC) injection regimen, which is commonly 0.3 to 0.6 mg/d. The reduction from the burden of two to three SC injections per day is a particular advantage of Sandostatin LAR, which is an attractive alternative to the approved Sandostatin injection.

  3. 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.

  4. 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.

  5. Large Deviations, Dynamics and Phase Transitions in Large Stochastic and Disordered Neural Networks

    NASA Astrophysics Data System (ADS)

    Cabana, Tanguy; Touboul, Jonathan

    2013-10-01

    Neuronal networks are characterized by highly heterogeneous connectivity, and this disorder was recently related experimentally to qualitative properties of the network. The motivation of this paper is to mathematically analyze the role of these disordered connectivities on the large-scale properties of neuronal networks. To this end, we analyze here large-scale limit behaviors of neural networks including, for biological relevance, multiple populations, random connectivities and interaction delays. Due to the randomness of the connectivity, usual mean-field methods (e.g. coupling) cannot be applied, but, similarly to studies developed for spin glasses, we will show that the sequences of empirical measures satisfy a large deviation principle, and converge towards a self-consistent non-Markovian process. From a mathematical viewpoint, the proof differs from previous works in that we are working in infinite-dimensional spaces (interaction delays) and consider multiple cell types. The limit obtained formally characterizes the macroscopic behavior of the network. We propose a dynamical systems approach in order to address the qualitative nature of the solutions of these very complex equations, and apply this methodology to three instances in order to show how non-centered coefficients, interaction delays and multiple populations networks are affected by disorder levels. We identify a number of phase transitions in such systems upon changes in delays, connectivity patterns and dispersion, and particularly focus on the emergence of non-equilibrium states involving synchronized oscillations.

  6. Phase Equilibria Impetus For Large-Volume Explosive Volcanic Eruptions

    NASA Astrophysics Data System (ADS)

    Fowler, S. J.; Spera, F. J.; Bohrson, W. A.; Ghiorso, M. S.

    2006-12-01

    We have investigated the phase equilibria and associated variations in melt and magma thermodynamic and transport properties of seven large-volume silicic explosive volcanic systems through application of the MELTS (Ghiorso &Sack, 1995) algorithm. Each calculation is based on fractional crystallization along an oxygen buffer at low-pressure (0.1 - 0.3 GPa), starting from a mafic parental liquid. Site-specific geological constraints provide starting conditions for each system. We have performed calculations for seven tuffs; the Otowi (~400 km3) and Tshirege (~200 km3) members of the Bandelier Tuff, the ~600 km3 Bishop Tuff, and the 2500, 300, and 1000 km3 Yellowstone high-silica rhyolite tuffs. These represent the six largest eruptions within North America over the past ~2 million years. The seventh tuff, the 39.3 ka Campanian Ignimbrite, a 200 km3 trachytic to phonolitic ignimbrite located near Naples, Italy, is the largest explosive eruption in the Mediterranean area in the last 200 kyr. In all cases, MELTS faithfully tracks the liquid line of descent as well as the identity and composition of phenocrysts. The largest discrepancy between predicted and observed melt compositions is for CaO in all calculations. A key characteristic for each system is a pseudoinvariant temperature, Tinv, where abrupt shifts in crystallinity (1-fm, where fm is the fraction of melt), volume fraction of supercritical fluid (θ), magma compressibility, melt and magma density, and viscosity occur over a small temperature interval of order 1 - 10 K. In particular, the volume fraction of vapor increases from θ ~0.1 just below Tinv to θ >0.7 just above Tinv for each case. The rheological transition between melt-dominated (high viscosity) and bubble-dominated (low viscosity) magma occurs at θ ~0.6. We emphasize that this effect is observed under isobaric conditions and is distinct from the oft-studied phenomenon of volatile exsolution accompanying magma decompression and subsequent

  7. 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.

  8. 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)

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. Lars-Göran Öst.

    PubMed

    Andersson, Gerhard; Holmes, Emily A; Carlbring, Per

    2013-01-01

    Lars-Göran Öst is one of the most eminent clinical researchers in the field of cognitive behaviour therapy (CBT) and a founder of CBT in Sweden. He has recently retired from his position as professor in clinical psychology at Stockholm University, Sweden. In this paper, we sketch a brief description of the body of work by Öst. Examples of his innovative and pioneering new treatment methods include the one-session treatment for specific phobias, as well as applied relaxation for a range of anxiety disorders and health conditions. While Öst remains active in the field, he has contributed significantly to the development and dissemination of CBT in Sweden as well as in the world.

  18. Fast, large and controllable phase modulation using dual frequency liquid crystals

    NASA Astrophysics Data System (ADS)

    Kirby, Andrew K.; Love, Gordon D.

    2004-04-01

    We report on a method for high speed, large stroke phase modulation using dual frequency control of liquid crystals. Our system uses an all-electronic feedback system in order to simplify the control. We show half wave phase modulations of ~120Hz with the operating point varying over nearly the full dynamic range of the device, and demonstrate larger phase shifts (2.5 waves) at a frequency of 37Hz. For large phase shifts, the speeds are an order of magnitude faster than existing techniques.

  19. Resolution to the Supersymmetric CP Problem with Large Soft Phases via D-Branes

    SciTech Connect

    Brhlik, M.; Everett, L.; Kane, G.L.; Lykken, J.

    1999-09-01

    We examine the soft supersymmetry breaking parameters that result from various ways of embedding the standard model (SM) on D-branes within the type I string picture, allowing the parameters to have large CP -violating phases. One embedding naturally provides the relations among soft parameters to satisfy the electron and neutron electric dipole moment constraints even with large phases, while with other embeddings large phases are not allowed. The results generally suggest how low energy data might teach us about Planck scale physics. {copyright} {ital 1999} {ital The American Physical Society}

  20. Enantioselective Regulation of Lactate Racemization by LarR in Lactobacillus plantarum

    PubMed Central

    Desguin, Benoît; Goffin, Philippe; Bakouche, Nordine; Diman, Aurélie; Viaene, Eric; Dandoy, Damien; Fontaine, Laetitia; Hallet, Bernard

    2014-01-01

    Lactobacillus plantarum is a lactic acid bacterium that produces a racemic mixture of l- and d-lactate from sugar fermentation. The interconversion of lactate isomers is performed by a lactate racemase (Lar) that is transcriptionally controlled by the l-/d-lactate ratio and maximally induced in the presence of l-lactate. We previously reported that the Lar activity depends on the expression of two divergently oriented operons: (i) the larABCDE operon encodes the nickel-dependent lactate racemase (LarA), its maturases (LarBCE), and a lactic acid channel (LarD), and (ii) the larR(MN)QO operon encodes a transcriptional regulator (LarR) and a four-component ABC-type nickel transporter [Lar(MN), in which the M and N components are fused, LarQ, and LarO]. LarR is a novel regulator of the Crp-Fnr family (PrfA group). Here, the role of LarR was further characterized in vivo and in vitro. We show that LarR is a positive regulator that is absolutely required for the expression of Lar activity. Using gel retardation experiments, we demonstrate that LarR binds to a 16-bp palindromic sequence (Lar box motif) that is present in the larR-larA intergenic region. Mutations in the Lar box strongly affect LarR binding and completely abolish transcription from the larA promoter (PlarA). Two half-Lar boxes located between the Lar box and the −35 box of PlarA promote LarR multimerization on DNA, and point mutations within one or both half-Lar boxes inhibit PlarA induction by l-lactate. Gel retardation and footprinting experiments indicate that l-lactate has a positive effect on the binding and multimerization of LarR, while d-lactate antagonizes the positive effect of l-lactate. A possible mechanism of LarR regulation by lactate enantiomers is proposed. PMID:25349156

  1. Evaluation of Foamseal ceiling panels in the large scale climate simulator under winder conditions. Phase I

    SciTech Connect

    Wilkes, K.E.; Childs, P.W.

    1991-11-01

    This report serves to document Phase I of tests on ceiling panels fabricated by Foamseal Urethane Technology, Inc. in the Large Scale Climate Simulator (LSCS). The work reported here was accomplished during August, 1991.

  2. Phase stabilization of a large-mode-area ytterbium-doped fiber amplifier.

    PubMed

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

    2007-03-01

    Measurements are reported on the open and closed-loop phase stability of a large-mode-area ytterbium-doped fiber amplifier. Phase fluctuations are characterized by a high-frequency low-amplitude jitter superimposed on a slow power-dependent drift. The amplifier may be phase locked to a precision of lambda/20 by using a low-bandwidth feedback loop. PMID:17392889

  3. Fabrication of large aperture kinoform phase plates in fused silica for smoothing focal plane intensity profiles

    SciTech Connect

    Rushford, M.; Dixit, S.; Thomas, I.; Perry, M.

    1996-04-26

    We have fabricated large aperture (40-cm) kinoform phase plates for producing super-Gaussian focal plane intensity profiles. The continuous phase screen, designed using a new iterative procedure, was fabricated in fused silica as a 16-level, one-wave deep rewrapped phase profile using a lithographic process and wet etching in buffered hydrofluoric acid. The observed far-field contains 94% of the incident energy inside the desired spot.

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

    PubMed

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

    2015-05-01

    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. PMID:25969314

  5. 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…

  6. Histological characteristics and ultrastructure of polyethylene terephthalate LARS ligament after the reconstruction of anterior cruciate ligament in rabbits

    PubMed Central

    Yu, Shao-Bin; Yang, Rong-Hua; Zuo, Zhong-Nan; Dong, Qi-Rong

    2014-01-01

    Polyethylene terephthalate LARS ligament were the remnant of LARS ligament used for repairing posterior cruciate ligament obtained from operation. We want to study histological characteristics and ultrastructure of polyethylene terephthalate LARS ligament after the reconstruction of anterior cruciate ligament in rabbits. Therefore, we replaced the original ACL with polyethylene terephthalate LARS ligament which was covering with the remnant of ACL in 9 rabbits (L-LARS group), while just only polyethylene terephthalate LARS ligament were transplanted in 3 rabbits (LARS group) with the remnant of ACL. Compared with group LARS, inflammatory cell reaction and foreign body reaction were more significant in group L-LARS. Moreover, electron microscopy investigation showed the tissue near LARS fibers was highly cellular with a matrix of thin collagen fibrils (50-100 nm) in group L-LARS. These above findings suggest the polyethylene terephthalate LARS ligament possess the high biocompatibility, which contributes to the polyethylene terephthalate LARS covered with recipient connective tissues. PMID:25356104

  7. 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.

  8. Testing the QCD string at large Nc from the thermodynamics of the hadronic phase

    NASA Astrophysics Data System (ADS)

    Cohen, Thomas D.

    2007-02-01

    It is generally believed that in the limit of a large number of colors (Nc) the description of confinement via flux tubes becomes valid and QCD can be modeled accurately via a hadronic string theory—at least for highly excited states. QCD at large Nc also has a well-defined deconfinement transition at a temperature Tc. In this talk it is shown how the thermodyanmics of the metastable hadronic phase of QCD (above Tc) at large NC can be related directly to properties of the effective QCD string. The key points in the derivation is the weakly interacting nature of hadrons at large Nc and the existence of a Hagedorn temperature TH for the effective string theory. From this it can be seen at large Nc and near TH, the energy density and pressure of the hadronic phase scale as E ˜ (TH - T)-(D⊥-6)/2 (for D⊥ < 6) and P ˜ (TH - T)-(D⊥-4)/2 (for D⊥ < 4) where D⊥ is the effective number of transverse dimensions of the string theory. This behavior for D⊥ < 6 is qualitatively different from typical models in statistical mechanics and if observed on the lattice would provide a direct test of the stringy nature of large Nc QCD. However since it can be seen that TH > Tc this behavior is of relevance only to the metastable phase. The prospect of using this result to extract D⊥ via lattice simulations of the metastable hadronic phase at moderately large Nc is discussed.

  9. 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

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

    PubMed

    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

  11. 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.

  12. 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.

  13. No large scale curvature perturbations during the waterfall phase transition of hybrid inflation

    SciTech Connect

    Abolhasani, Ali Akbar; Firouzjahi, Hassan

    2011-03-15

    In this paper the possibility of generating large scale curvature perturbations induced from the entropic perturbations during the waterfall phase transition of the standard hybrid inflation model is studied. We show that whether or not appreciable amounts of large scale curvature perturbations are produced during the waterfall phase transition depends crucially on the competition between the classical and the quantum mechanical backreactions to terminate inflation. If one considers only the classical evolution of the system, we show that the highly blue-tilted entropy perturbations induce highly blue-tilted large scale curvature perturbations during the waterfall phase transition which dominate over the original adiabatic curvature perturbations. However, we show that the quantum backreactions of the waterfall field inhomogeneities produced during the phase transition dominate completely over the classical backreactions. The cumulative quantum backreactions of very small scale tachyonic modes terminate inflation very efficiently and shut off the curvature perturbation evolution during the waterfall phase transition. This indicates that the standard hybrid inflation model is safe under large scale curvature perturbations during the waterfall phase transition.

  14. 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.

  15. Scintillation light detection system in LArIAT

    NASA Astrophysics Data System (ADS)

    Kryczynski, P.

    2016-02-01

    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

  16. 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.

  17. Design and fabrication of a large airborne phased-array antenna

    NASA Astrophysics Data System (ADS)

    Cooke, William P.; Harris, Joseph M.; Jameson, Calvin R.

    1989-01-01

    A large phased-array antenna has been developed and mounted for missile test range trials on the Dash 8 aircraft, with a view to eventual installation on the E-9A Airborne Platform. The antenna is a one-dimensional scan, multiple-channel phased array of 30-ft length and 30-in height. This polarization-insensitive antenna operates in the 2.2-2.4 range, and uses modular parts to improve reliability and reduce maintenance time; being electronically steerable, the phased-array antenna is able to simultaneously receive five independent telemetry signals within its field-of-view.

  18. 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.

  19. Single atom-scale diamond defect allows a large Aharonov-Casher phase

    SciTech Connect

    Maclaurin, D.; Hollenberg, L. C. L.; Greentree, A. D.; Martin, A. M.; Cole, J. H.

    2009-10-15

    We propose an experiment that would produce and measure a large Aharonov-Casher (AC) phase in a solid-state system under macroscopic motion. A diamond crystal is mounted on a spinning disk in the presence of a uniform electric field. Internal magnetic states of a single nitrogen-vacancy (N-V) defect, replacing interferometer trajectories, are coherently controlled by microwave pulses. The AC phase shift is manifested as a relative phase, of up to 17 radians, between components of a superposition of magnetic substates, which is two orders of magnitude larger than that measured in any other atom-scale quantum system.

  20. 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

  1. Observation of large photoacoustic signal phase changes during a diffusion process.

    PubMed

    Bajic, Stanley J; Jones, Roger W; McClelland, John F

    2005-11-01

    The phase of the photoacoustic signal is known to be a sensitive and accurate means to investigate, both qualitatively and quantitatively, static multilayer heterogeneous systems. According to theory, the maximum phase delay for a very weakly absorbing homogeneous sample should be within 45 degrees of a very strongly absorbing sample, while for heterogeneous samples the phase delay can be greater than 45 degrees. Here we report the observation of photoacoustic phase delays greater than 350 degrees by extending the use of step-scan phase modulation photoacoustic spectroscopy to study a non-repetitive dynamic system in situ, in real time. These large phase delays correspond to sampling several thermal diffusion lengths into the sample. The model system used in this study consisted of a hydrocarbon grease diffusing through a porous Teflon film. The progress of the diffusion was tracked by monitoring both the photoacoustic signal magnitude and the phase of the hydrocarbon grease after isolation from the Teflon film signal contributions at two different phase modulation frequencies.

  2. 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...

  3. Microwave millisecond spike emission and its associated phenomena during the impulsive phase of large flares

    NASA Technical Reports Server (NTRS)

    Li, Chunsheng; Jiang, Shuying; Li, Hongwei; Fu, Qi-Jun

    1986-01-01

    A tentative model is proposed to account for some features of the microwave millisecond spike emission and its links with the physical processes of associated phenomena during the impulsive phase of large flares by comparing the optical, radio, and X-ray observations on May 16, 1981 to those on October 12, 1981.

  4. 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.

  5. Testing the QCD string at large Nc from the thermodynamics of the hadronic phase

    SciTech Connect

    Cohen, Thomas D.

    2007-02-27

    It is generally believed that in the limit of a large number of colors (Nc) the description of confinement via flux tubes becomes valid and QCD can be modeled accurately via a hadronic string theory-at least for highly excited states. QCD at large Nc also has a well-defined deconfinement transition at a temperature Tc. In this talk it is shown how the thermodyanmics of the metastable hadronic phase of QCD (above Tc) at large NC can be related directly to properties of the effective QCD string. The key points in the derivation is the weakly interacting nature of hadrons at large Nc and the existence of a Hagedorn temperature TH for the effective string theory. From this it can be seen at large Nc and near TH, the energy density and pressure of the hadronic phase scale as E {approx} (TH - T)-(D perpendicular -6)/2 (for D perpendicular < 6) and P {approx} (TH - T)-(D perpendicular -4)/2 (for D perpendicular < 4) where D perpendicular s the effective number of transverse dimensions of the string theory. This behavior for D perpendicular < 6 is qualitatively different from typical models in statistical mechanics and if observed on the lattice would provide a direct test of the stringy nature of large Nc QCD. However since it can be seen that TH > Tc this behavior is of relevance only to the metastable phase. The prospect of using this result to extract D perpendicular via lattice simulations of the metastable hadronic phase at moderately large Nc is discussed.

  6. 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.

  7. 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.

  8. Phasing for medical sequencing using rare variants and large haplotype reference panels

    PubMed Central

    Sharp, Kevin; Kretzschmar, Warren; Delaneau, Olivier; Marchini, Jonathan

    2016-01-01

    Motivation: There is growing recognition that estimating haplotypes from high coverage sequencing of single samples in clinical settings is an important problem. At the same time very large datasets consisting of tens and hundreds of thousands of high-coverage sequenced samples will soon be available. We describe a method that takes advantage of these huge human genetic variation resources and rare variant sharing patterns to estimate haplotypes on single sequenced samples. Sharing rare variants between two individuals is more likely to arise from a recent common ancestor and, hence, also more likely to indicate similar shared haplotypes over a substantial flanking region of sequence. Results: Our method exploits this idea to select a small set of highly informative copying states within a Hidden Markov Model (HMM) phasing algorithm. Using rare variants in this way allows us to avoid iterative MCMC methods to infer haplotypes. Compared to other approaches that do not explicitly use rare variants we obtain significant gains in phasing accuracy, less variation over phasing runs and improvements in speed. For example, using a reference panel of 7420 haplotypes from the UK10K project, we are able to reduce switch error rates by up to 50% when phasing samples sequenced at high-coverage. In addition, a single step rephasing of the UK10K panel, using rare variant information, has a downstream impact on phasing performance. These results represent a proof of concept that rare variant sharing patterns can be utilized to phase large high-coverage sequencing studies such as the 100 000 Genomes Project dataset. Availability and implementation: A webserver that includes an implementation of this new method and allows phasing of high-coverage clinical samples is available at https://phasingserver.stats.ox.ac.uk/. Contact: marchini@stats.ox.ac.uk Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27153703

  9. 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

  10. 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.

  11. 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.

  12. 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).

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. HIGH RESOLUTION SPECTROSCOPY IN THE GAS PHASE: Even Large Molecules Have Well-Defined Shapes

    NASA Astrophysics Data System (ADS)

    Pratt, David W.

    1998-10-01

    A review of recent high-resolution microwave, infrared, and optical spectroscopy experiments demonstrates that remarkable progress has been made in the past 20 years in determining the equilibrium geometries of large polyatomic molecules and their clusters in the gas phase, and how these geometries change when the photon is absorbed. A special focus is on the dynamical information that can be obtained from such studies, particularly of electronically excited states.

  18. Large Microwave Birefringence Liquid-Crystal Characterization for Phase-Shifter Applications

    NASA Astrophysics Data System (ADS)

    Dubois, Frédéric; Krasinski, Freddy; Splingart, Bertrand; Tentillier, Nicolas; Legrand, Christian; Spadlo, Anna; Dabrowski, Roman

    2008-05-01

    This work is concerned with the improvement of a microwave liquid-crystal phase shifter using a large birefringence nematic liquid crystal. This material is a eutectic mixture of isothiocyanatotolane molecules. Microwave dielectric properties are reported and compared to the data obtained with the 5CB cyanobiphenyl material in the 26-40 GHz frequency range using a rectangular waveguide. The phase-shifter design consists of a central cavity, where a liquid crystal is inserted, and two coplanar strip lines accesses. Its dimensions were calculated by electromagnetic simulation, using measured dielectric permittivities of the liquid crystal. The measurements were performed with a commercial Wiltron 3680 K probe test fixture. Phase-shift variations with and without bias voltage versus frequency are presented. As expected, the large-birefringence nematic liquid crystal exhibits a higher microwave dielectric anisotropy (Δɛ' = 1.06 against 0.34) and the tunability of the phase shifter strongly increases (1.8 deg·cm-1·GHz-1 against 0.8 deg·cm-1·GHz-1).

  19. 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.

  20. 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

  1. 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.

  2. Large Eddy Simulation of diesel injector opening with a two phase cavitation model

    NASA Astrophysics Data System (ADS)

    Koukouvinis, P.; Gavaises, M.; Li, J.; Wang, L.

    2015-12-01

    In the current paper, indicative results of the flow simulation during the opening phase of a Diesel injector are presented. In order to capture the complex flow field and cavitation structures forming in the injector, Large Eddy Simulation has been employed, whereas compressibility of the liquid was included. For taking into account cavitation effects, a two phase homogenous mixture model was employed. The mass transfer rate of the mixture model was adjusted to limit as much as possible the occurrence of negative pressures. During the simulation, pressure peaks have been found in areas of vapour collapse, with magnitude beyond 4000bar, which is higher that the yield stress of common materials. The locations of such pressure peaks corresponds well with the actual erosion location as found from X ray scans.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. Dendronization-induced phase-transfer, stabilization and self-assembly of large colloidal Au nanoparticles

    NASA Astrophysics Data System (ADS)

    Malassis, Ludivine; Jishkariani, Davit; Murray, Christopher B.; Donnio, Bertrand

    2016-07-01

    The phase-transfer of CTAB-coated aqueous, spherical gold nanoparticles, with metallic core diameters ranging from ca. 27 to 54 nm, into organic solvents by exchanging the primitive polar bilayer with lipophilic, disulfide dendritic ligands is reported. The presence of such a thick nonpolar organic shell around these large nanoparticles enhances their stabilization against aggregation, in addition to enabling their transfer into a variety of solvents such as chloroform, toluene or tetrahydrofuran. Upon the slow evaporation of a chloroform suspension deposited on a solid support, the dendronized hybrids were found to self-assemble into ring structures of various diameters. Moreover, their self-assembly at the liquid-air interface affords the formation of fairly long-range ordered monolayers, over large areas, that can then be entirely transferred onto solid substrates.The phase-transfer of CTAB-coated aqueous, spherical gold nanoparticles, with metallic core diameters ranging from ca. 27 to 54 nm, into organic solvents by exchanging the primitive polar bilayer with lipophilic, disulfide dendritic ligands is reported. The presence of such a thick nonpolar organic shell around these large nanoparticles enhances their stabilization against aggregation, in addition to enabling their transfer into a variety of solvents such as chloroform, toluene or tetrahydrofuran. Upon the slow evaporation of a chloroform suspension deposited on a solid support, the dendronized hybrids were found to self-assemble into ring structures of various diameters. Moreover, their self-assembly at the liquid-air interface affords the formation of fairly long-range ordered monolayers, over large areas, that can then be entirely transferred onto solid substrates. Electronic supplementary information (ESI) available: TEM microscope images. See DOI: 10.1039/c6nr03404g

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    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 of the PIRENEA setup 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.

  11. 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

  12. 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.

  13. 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.

  14. 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. PMID:22315523

  15. 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

  16. T/R module development for large aperture L-band phased array

    NASA Technical Reports Server (NTRS)

    Chamberlain, Neil; Andricos, Constantine; Kumley, Kendra; Berkun, Andrew; Hodges, Richard; Spitz, Suzanne

    2004-01-01

    This paper describes a transmit / receive (T/R) module for a large L-band space based radar active phased array being developed at JPL. Electrical performance and construction techniques are described, with emphasis on the former. The T/R modules have a bandwidth of more than 80 MHz centered at 1260MHz and support dual, switched polarizations. Phase and amplitude are controlled by a 6-bit phase shifter and a 6-bit attenuator, respectively. The transmitter power amplifier generates 2.4 W into a nominal 50 ohm load with 36% overall efficiency. The receiver noise figure is 4.4 dB including all front-end losses. The module weighs 32 g and has a footprint of 8 cm x 4.5 cm. Fourteen of these T/R modules were fabricated at the JPL Pick-and-Place Facility and were tested using a computer-controlled measurement facility developed at JPL. Calibrated performance of this set of T/R modules is presented and shows good agreement with design predictions.

  17. 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.

  18. W-phase Source Inversion Using High-rate Regional GPS Data for Large Earthquakes.

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    W-phase moment tensor inversions have been proven to be a reliable method for rapid characterization for large earthquakes. W-phase is a long period seismic (100s-1000s) wave that arrives between P and S waves and can be synthesized by normal mode summation. For global purposes it has been used at USGS, PTWC and IPGS. These implementations provide moment tensor solutions within 30-60 min after the origin time of moderate and large worldwide earthquakes. W-phase inversion has been successfully implemented at the Chilean National Seismological Center (CSN) for regional distances (5º-12º) obtaining the first solution ~6 minutes after the earthquake. However until now it has been used only with broadband instruments, which saturate in the near field. Therefore, we use near field records from high-rate regional GPS data for some large earthquakes that have occurred in the past five years and with relatively dense azimuthal and station density coverage.Originally the inversion takes the time interval between Tp and Tp + 15 *delta (distance from the epicenter in degrees). In the near field W-phase doesn't develop as well as in the intermediate or far field, therefore we increased the time window for these events. Here we tried different time windows to find the most accurate result for each earthquake and to reduce time response for tsunami early warning purposes. We took near field GPS for the following earthquakes: The 2010 Mw 8.8 Maule Earthquake, the 2011 Mw 9.1 Tohoku Earthquake, The 2014 Mw 8.2 Iquique Earthquake, and The 2014 Mw 7.8 Iquique Aftershock. The solutions for the examples tested here are potentially available 5 min after the origin time. The calculated magnitude for each earthquake is: Mw 8.9 for the Maule earthquake, Mw 9.1 for the Tohoku earthquake, Mw 7.9 for the Iquique earthquake, and Mw 7.8 for the Iquique aftershock. The mechanisms, as expected, are thrust with some variations with respect to the WCMT from National Earthquake Information Center

  19. Large magnetocrystalline anisotropy in bilayer transition metal phases from first-principles full-potential calculations

    NASA Astrophysics Data System (ADS)

    Ravindran, P.; Kjekshus, A.; Fjellvåg, H.; James, P.; Nordström, L.; Johansson, B.; Eriksson, O.

    2001-04-01

    The computational framework of this study is based on the local-spin-density approximation with first-principles full-potential linear muffin-tin orbital calculations including orbital polarization (OP) correction. We have studied the magnetic anisotropy for a series of bilayer CuAu(I)-type materials such as FeX, MnX (X=Ni,Pd,Pt), CoPt, NiPt, MnHg, and MnRh in a ferromagnetic state using experimental structural parameters to understand the microscopic origin of magnetic-anisotropy energy (MAE) in magnetic multilayers. Except for MnRh and MnHg, all these phases show perpendicular magnetization. We have analyzed our results in terms of angular momentum-, spin- and site-projected density of states, magnetic-angular-momentum-projected density of states, orbital-moment density of states, and total density of states. The orbital-moment number of states and the orbital-moment anisotropy for FeX (X=Ni,Pd,Pt) are calculated as a function of band filling to study its effect on MAE. The total and site-projected spin and orbital moments for all these systems are calculated with and without OP when the magnetization is along or perpendicular to the plane. The results are compared with available experimental as well as theoretical results. Our calculations show that OP always enhances the orbital moment in these phases and brings them closer to experimental values. The changes in MAE are analyzed in terms of exchange splitting, spin-orbit splitting, and tetragonal distortion/crystal-field splitting. The calculated MAE is found to be in good agreement with experimental values when the OP correction is included. Some of the materials considered here show large magnetic anisotropy of the order of meV. In particular we found that MnPt will have a very large MAE if it could be stabilized in a ferromagnetic configuration. Our analysis indicates that apart from large spin-orbit interaction and exchange interaction from at least one of the constituents, a large crystal-field splitting

  20. 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 has defined the subject merchandise as ``large liquid dielectric power transformers (LPTs)...

  1. Liprin-alpha has LAR-independent functions in R7 photoreceptor axon targeting.

    PubMed

    Hofmeyer, Kerstin; Maurel-Zaffran, Corinne; Sink, Helen; Treisman, Jessica E

    2006-08-01

    In the Drosophila visual system, the color-sensing photoreceptors R7 and R8 project their axons to two distinct layers in the medulla. Loss of the receptor tyrosine phosphatase LAR from R7 photoreceptors causes their axons to terminate prematurely in the R8 layer. Here we identify a null mutation in the Liprin-alpha gene based on a similar R7 projection defect. Liprin-alpha physically interacts with the inactive D2 phosphatase domain of LAR, and this domain is also essential for R7 targeting. However, another LAR-dependent function, egg elongation, requires neither Liprin-alpha nor the LAR D2 domain. Although human and Caenorhabditis elegans Liprin-alpha proteins have been reported to control the localization of LAR, we find that LAR localizes to focal adhesions in Drosophila S2R+ cells and to photoreceptor growth cones in vivo independently of Liprin-alpha. In addition, Liprin-alpha overexpression or loss of function can affect R7 targeting in the complete absence of LAR. We conclude that Liprin-alpha does not simply act by regulating LAR localization but also has LAR-independent functions. PMID:16864797

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Microstrip patch antenna panel for large aperture L-band phased array

    NASA Technical Reports Server (NTRS)

    Chamberlain, Neil; Amaro, Luis; Oakes, Eric; Hodges, Richard; Spitz, Suzanne; Rosen, Paul A.

    2004-01-01

    This paper describes the design and development of a large, lightweight antenna panel for an active phased array operating at L-band. The panel was developed under a JPL program of technology development for space based radar. It utilizes dual-stacked patch elements that are interconnected with corporate feed manifold of striplines. This paper focuses on the electromagnetic design and performance of the radiating elements, with emphasis on scan performance, and also addresses mechanical and thermal aspects of the panel. The element in the array environment has a bandwidth of more than 80MHz centered at 1260MHz and is fed so that it can radiate orthogonal linear polarizations. The envisioned phased array, with a nominal aperture of 50m x 2m, is designed to scan +/-45 degrees in azimuth and +/-20 degrees in elevation. The panel of radiating elements has a mass density of 3.9 kg/m2, which represents approximately 50% of the target 8kg/m2 total panel mass density that includes T/R modules and feed manifolds.

  9. Lanreotide Autogel 120 mg at extended dosing intervals in patients with acromegaly biochemically controlled with octreotide LAR: the LEAD study

    PubMed Central

    Neggers, Sebastian JCMM; Pronin, Vyacheslav; Balcere, Inga; Lee, Moon-Kyu; Rozhinskaya, Liudmila; Bronstein, Marcello D; Gadelha, Mônica R; Maisonobe, Pascal; Sert, Caroline; van der Lely, Aart Jan

    2015-01-01

    Objective To evaluate extended dosing intervals (EDIs) with lanreotide Autogel 120 mg in patients with acromegaly previously biochemically controlled with octreotide LAR 10 or 20 mg. Design and methods Patients with acromegaly had received octreotide LAR 10 or 20 mg/4 weeks for ≥6 months and had normal IGF1 levels. Lanreotide Autogel 120 mg was administered every 6 weeks for 24 weeks (phase 1); depending on week-24 IGF1 levels, treatment was then administered every 4, 6 or 8 weeks for a further 24 weeks (phase 2). Hormone levels, patient-reported outcomes and adverse events were assessed. Primary endpoint: proportion of patients on 6- or 8-week EDIs with normal IGF1 levels at week 48 (study end). Results 107/124 patients completed the study (15 withdrew from phase 1 and two from phase 2). Of 124 patients enrolled, 77.4% were allocated to 6- or 8-week EDIs in phase 2 and 75.8% (95% CI: 68.3–83.3) had normal IGF1 levels at week 48 with the EDI (primary analysis). A total of 88.7% (83.1–94.3) had normal IGF1 levels after 24 weeks with 6-weekly dosing. GH levels were ≤2.5 μg/l in >90% of patients after 24 and 48 weeks. Patient preferences for lanreotide Autogel 120 mg every 4, 6 or 8 weeks over octreotide LAR every 4 weeks were high. Conclusions Patients with acromegaly achieving biochemical control with octreotide LAR 10 or 20 mg/4 weeks are possible candidates for lanreotide Autogel 120 mg EDIs. EDIs are effective and well received among such patients. PMID:26047625

  10. Calibration of spatially phase-shifted DSPI for measurement of large structures.

    PubMed

    Saif, Babak; Eegholm, Bente Hoffmann; Bluth, Marcel; Greenfield, Perry; Hack, Warren; Blake, Peter; Keski-Kuha, Ritva; North-Morris, Michael

    2007-08-10

    We present a method for the calibration of a spatially phase-shifted digital speckle pattern interferometer (SPS-DSPI), which was designed and built for the purpose of testing the James Webb space telescope (JWST) optical structures and related technology development structures. The need to measure dynamic deformations of large, diffuse structures to nanometer accuracy at cryogenic temperature is paramount in the characterization of a large diameter space and terrestrial based telescopes. The techniques described herein apply to any situation, in which high accuracy measurement of diffuse structures are required. The calibration of the instrument is done using a single-crystal silicon gauge. The gauge has four islands of different heights that change in a predictable manner as a function of temperature. The SPS-DSPI is used to measure the relative piston between the islands as the temperature of the gauge is changed. The measurement results are then compared with the theoretical changes in the height of the gauge islands. The maximum deviation of the measured rate of change of the relative piston in nm/K from the expected value is 3.3%.

  11. Measurement of large cryogenic structures using a spatially phase-shifted digital speckle pattern interferometer.

    PubMed

    Saif, Babak; Bluth, Marcel; Greenfield, Perry; Hack, Warren; Eegholm, Bente Hoffmann; Blake, Peter; Keski-Kuha, Ritva; Feinberg, Lee; Arenberg, Jonathan W

    2008-02-20

    The James Webb Space Telescope (JWST) Backplane Stability Test Article (BSTA) was developed to demonstrate large precision cryogenic structures' technology readiness for use in the JWST. The thermal stability of the BSTA was measured at cryogenic temperatures at the Marshall Space Flight Center (MSFC) X-Ray Calibration Facility (XRCF) and included nearly continuous measurements over a six-week period in the summer of 2006 covering the temperature range from ambient down to 30 Kusing a spatially phase-shifted digital speckle pattern interferometer (SPS-DSPI). The BSTA is a full size, one-sixth section of the JWST primary mirror backplane assembly (PMBA). The BSTA, measuring almost 3 m across, contains most of the prominent structural elements of the backplane and is to our knowledge the largest structure ever measured with SPS-DSPI at cryogenic conditions. The SPS-DSPI measured rigid body motion and deformations of BSTA to nanometer-level accuracy. The SPS-DSPI was developed specifically for the purposes of this test and other tests of large cryogenic structures for JWST.

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

    NASA Astrophysics Data System (ADS)

    Wang, X.; Konrad, G.; Abele, H.

    2013-02-01

    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.

  13. 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.

  14. 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

  15. 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.

  16. Investigation into the efficacy and safety of octreotide LAR in Japanese patients with acromegaly: Shizuoka study.

    PubMed

    Oki, Yutaka; Inoue, Tatsuhide; Imura, Mitsuo; Tanaka, Tokutaro; Genma, Rieko; Iwabuchi, Masayasu; Hataya, Yuji; Matsuzawa, Yuji; Iino, Kazumi; Nishizawa, Shigeru; Nakamura, Hirotoshi

    2009-01-01

    The efficacy and safety of the long-acting repeatable formulation of octreotide (OCT-LAR) treatment in patients suffering from acromegaly was investigated retrospectively in Shizuoka prefecture, Japan. Thirty patients (11 male, 19 female; average age, 48.9 years old), 29 of whom had undergone transsphenoidal surgery previously, were treated with OCT-LAR. OCT-LAR was injected i.m. every 4 weeks with an intended protocol of 20 mg over 24 months, however, 46.7% of patients required the dose of OCT-LAR to be increased. The final average dose of OCT-LAR was 25.0 +/- 6.8 mg. Administering OCT-LAR significantly decreased serum GH and insulin-like growth factor 1 (IGF-1) levels (from 13.7 +/- 11.9 to 5.8 +/- 7.3 microg/L and from 585 +/- 263 to 339 +/- 193.7 microg/L after 3 months, respectively). Among patients treated with OCT-LAR, 56.7% expressed LAR did not have a negative effect on glucose tolerance when hemoglobin A1c was used as a marker. A gallbladder polyp was found only in 1 patient but it was uncertain whether OCT-LAR was involved in its development because the patient was not examined before OCT-LAR treatment. There were no abnormalities on liver function tests in any patients. In conclusion, our results showed that OCT-LAR was safe and effective as a therapeutic option for Japanese patients with acromegaly in a postoperative setting, by controlling the disease activity. PMID:19755754

  17. Language Arts Routing System (LARS) Instructor's Manual. Community College English Project.

    ERIC Educational Resources Information Center

    Michael, Gary; Sliger, Mary

    Implemented on the PLATO IV computer-assisted instruction facility located at the University of Illinois at Urbana-Champaign, the Language Arts Routing System (LARS) is a package of lessons and tests designed to provide remedial training in certain basic language arts skills. LARS is a system which may be used by itself or as an adjunct to regular…

  18. 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.

  19. 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

  20. 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

  1. 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. PMID:26729057

  2. Dynamical phase transition in large-deviation statistics of the Kardar-Parisi-Zhang equation

    NASA Astrophysics Data System (ADS)

    Janas, Michael; Kamenev, Alex; Meerson, Baruch

    2016-09-01

    We study the short-time behavior of the probability distribution P (H ,t ) of the surface height h (x =0 ,t )=H in the Kardar-Parisi-Zhang (KPZ) equation in 1 +1 dimension. The process starts from a stationary interface: h (x ,t =0 ) is given by a realization of two-sided Brownian motion constrained by h (0 ,0 )=0 . We find a singularity of the large deviation function of H at a critical value H =Hc . The singularity has the character of a second-order phase transition. It reflects spontaneous breaking of the reflection symmetry x ↔-x of optimal paths h (x ,t ) predicted by the weak-noise theory of the KPZ equation. At |H |≫| Hc| the corresponding tail of P (H ) scales as -lnP ˜|H| 3 /2/t1 /2 and agrees, at any t >0 , with the proper tail of the Baik-Rains distribution, previously observed only at long times. The other tail of P scales as -lnP ˜|H| 5 /2/t1 /2 and coincides with the corresponding tail for the sharp-wedge initial condition.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. From somatostatin to octreotide LAR: evolution of a somatostatin analogue

    PubMed Central

    Anthony, Lowell; Freda, Pamela U.

    2013-01-01

    Background Acromegaly is characterized by overproduction of growth hormone (GH) by the pituitary gland. GH stimulates the synthesis of insulin-like growth factor-I (IGF-I), and the somatic growth and metabolic dysfunction that characterize acromegaly are a consequence of elevated GH and IGF-I levels. Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rare, slow-growing neoplasms that have usually metastasized by the time of diagnosis. The majority of GEP-NETs are carcinoid tumors whose syndrome is caused by the hypersecretion of biogenic amines, peptides and polypeptides responsible for the principal symptoms of diarrhea and flushing. Methods The MEDLINE and EMBASE databases were searched for preclinical and clinical studies of octreotide (Sandostatin*), a potent synthetic somatostatin analogue, in patients with acromegaly or GEP-NETs. Objective This article reviews the 20 years of clinical experience with octreotide and the impact it has made in patients with acromegaly or GEP-NETs. Results Octreotide has proven to be an essential component in the management strategy of acromegaly and GEP-NETs over the past 20 years. The multiple beneficial effects of octreotide throughout the body, combined with its established safety profile (the most common adverse effects are injection-site pain and gastrointestinal events), have made it an appealing option for clinicians. The advent of the long-acting release (LAR) formulation of octreotide provided additional benefits to patients through monthly administration, while maintaining the efficacy and tolerability profile of the daily subcutaneous formulation. Conclusions Octreotide is a potent synthetic somatostatin analogue that has become the mainstay of medical therapy for tumor control in neuroendocrine disorders such as acromegaly and GEP-NETs. The development of octreotide LAR offered a further advancement; less frequent dosing provided valuable benefits in quality of life to patients, with equivalent efficacy and

  12. Phase discrepancy induced from least squares wavefront reconstruction of wrapped phase measurements with high noise or large localized wavefront gradients

    NASA Astrophysics Data System (ADS)

    Steinbock, Michael J.; Hyde, Milo W.

    2012-10-01

    Adaptive optics is used in applications such as laser communication, remote sensing, and laser weapon systems to estimate and correct for atmospheric distortions of propagated light in real-time. Within an adaptive optics system, a reconstruction process interprets the raw wavefront sensor measurements and calculates an estimate for the unwrapped phase function to be sent through a control law and applied to a wavefront correction device. This research is focused on adaptive optics using a self-referencing interferometer wavefront sensor, which directly measures the wrapped wavefront phase. Therefore, its measurements must be reconstructed for use on a continuous facesheet deformable mirror. In testing and evaluating a novel class of branch-point- tolerant wavefront reconstructors based on the post-processing congruence operation technique, an increase in Strehl ratio compared to a traditional least squares reconstructor was noted even in non-scintillated fields. To investigate this further, this paper uses wave-optics simulations to eliminate many of the variables from a hardware adaptive optics system, so as to focus on the reconstruction techniques alone. The simulation results along with a discussion of the physical reasoning for this phenomenon are provided. For any applications using a self-referencing interferometer wavefront sensor with low signal levels or high localized wavefront gradients, understanding this phenomena is critical when applying a traditional least squares wavefront reconstructor.

  13. Cryopreservation of lar gibbon semen collected by manual stimulation.

    PubMed

    Takasu, Masaki; Morita, Natsumi; Tajima, Shunichiro; Almunia, Julio; Maeda, Masami; Kamiguchi, Takashi

    2016-07-01

    We confirmed ejaculation as a result of manual stimulation in a lar gibbon, and attempted to cryopreserve the semen using TES-Tris-egg yolk-based (TTE) extender. After measuring the amount of semen (g), we first diluted the semen with TTE extender, and calculated sperm concentration (sperm/ml), total sperm count (sperm), and progressive sperm motility (%). Then, we cooled diluted semen slowly to 4 °C over 2 h, and added an equal volume of secondary extender containing glycerol over 30 min. Finally, we flash-froze the semen solution by plunging into liquid nitrogen. In addition, we freeze-thawed the solution to determine the recovery rate of the motile sperm. Collection of semen was successful on four of the five occasions. The median (min-max) quantity of ejaculate was 0.19 g (0.09-0.26 g), the median sperm concentration was 1.38 × 10(9) sperm/ml (1.20-1.53 × 10(9) sperm/ml), and the median total sperm count was 0.26 × 10(9) sperm (0.11-0.40 × 10(9) sperm). Moreover, the median sperm motility immediately after ejaculation was 65 % (60-75 %), the median sperm motility after freeze-thawing was 30 % (25-35 %), and the median recovery rate was 42.3 % (40.0-58.3 %). We were able to (1) collect semen from a lar gibbon by manual stimulation, (2) reveal andrological findings regarding semen characteristics, and (3) preserve the genetic resource using TTE cryopreservation.

  14. Simultaneous generation of a frequency-multiplied and phase-shifted microwave signal with large tunability.

    PubMed

    Feng, Danqi; Xie, Heng; Chen, Guodong; Qian, Lifen; Sun, Junqiang

    2014-07-28

    We demonstrate a photonic approach to simultaneously realize a frequency-multiplied and phase-shifted microwave signal based on the birefringence effects in the high nonlinear fiber. The phase shift caused by asymmetric variations in refractive indexes of fiber between two orthogonal polarization states is introduced into two coherent harmonic of the modulated signals. By beating the phase-modulated sidebands, a frequency-multiplied microwave signal is generated and its phase can be adjusted by simply controlling the pump power. A microwave signal at doubled- or quadrupled-frequency with a full 2π phase shift is obtained over a frequency range from 10 GHz to 30 GHz. The proposed approach has the potential applications in the system with larger-broadband, higher-frequency and -data-rate system, even to handle a multi-wavelength operation.

  15. Influence of LAR and VAR on Para-Aminopyridine Antimalarials Targetting Haematin in Chloroquine-Resistance

    PubMed Central

    Warhurst, David C.; Craig, John C.

    2016-01-01

    Antimalarial chloroquine (CQ) prevents haematin detoxication when CQ-base concentrates in the acidic digestive vacuole through protonation of its p-aminopyridine (pAP) basic aromatic nitrogen and sidechain diethyl-N. CQ export through the variant vacuolar membrane export channel, PFCRT, causes CQ-resistance in Plasmodium falciparum but 3-methyl CQ (sontochin SC), des-ethyl amodiaquine (DAQ) and bis 4-aminoquinoline piperaquine (PQ) are still active. This is determined by changes in drug accumulation ratios in parasite lipid (LAR) and in vacuolar water (VAR). Higher LAR may facilitate drug binding to and blocking PFCRT and also aid haematin in lipid to bind drug. LAR for CQ is only 8.3; VAR is 143,482. More hydrophobic SC has LAR 143; VAR remains 68,523. Similarly DAQ with a phenol substituent has LAR of 40.8, with VAR 89,366. In PQ, basicity of each pAP is reduced by distal piperazine N, allowing very high LAR of 973,492, retaining VAR of 104,378. In another bis quinoline, dichlorquinazine (DCQ), also active but clinically unsatisfactory, each pAP retains basicity, being insulated by a 2-carbon chain from a proximal nitrogen of the single linking piperazine. While LAR of 15,488 is still high, the lowest estimate of VAR approaches 4.9 million. DCQ may be expected to be very highly lysosomotropic and therefore potentially hepatotoxic. In 11 pAP antimalarials a quadratic relationship between logLAR and logResistance Index (RI) was confirmed, while log (LAR/VAR) vs logRI for 12 was linear. Both might be used to predict the utility of structural modifications. PMID:27483471

  16. Influence of LAR and VAR on Para-Aminopyridine Antimalarials Targetting Haematin in Chloroquine-Resistance.

    PubMed

    Warhurst, David C; Craig, John C; Raheem, K Saki

    2016-01-01

    Antimalarial chloroquine (CQ) prevents haematin detoxication when CQ-base concentrates in the acidic digestive vacuole through protonation of its p-aminopyridine (pAP) basic aromatic nitrogen and sidechain diethyl-N. CQ export through the variant vacuolar membrane export channel, PFCRT, causes CQ-resistance in Plasmodium falciparum but 3-methyl CQ (sontochin SC), des-ethyl amodiaquine (DAQ) and bis 4-aminoquinoline piperaquine (PQ) are still active. This is determined by changes in drug accumulation ratios in parasite lipid (LAR) and in vacuolar water (VAR). Higher LAR may facilitate drug binding to and blocking PFCRT and also aid haematin in lipid to bind drug. LAR for CQ is only 8.3; VAR is 143,482. More hydrophobic SC has LAR 143; VAR remains 68,523. Similarly DAQ with a phenol substituent has LAR of 40.8, with VAR 89,366. In PQ, basicity of each pAP is reduced by distal piperazine N, allowing very high LAR of 973,492, retaining VAR of 104,378. In another bis quinoline, dichlorquinazine (DCQ), also active but clinically unsatisfactory, each pAP retains basicity, being insulated by a 2-carbon chain from a proximal nitrogen of the single linking piperazine. While LAR of 15,488 is still high, the lowest estimate of VAR approaches 4.9 million. DCQ may be expected to be very highly lysosomotropic and therefore potentially hepatotoxic. In 11 pAP antimalarials a quadratic relationship between logLAR and logResistance Index (RI) was confirmed, while log (LAR/VAR) vs logRI for 12 was linear. Both might be used to predict the utility of structural modifications. PMID:27483471

  17. 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

  18. 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

  19. Phase locking and supermode selection in multicore photonic crystal fiber lasers with a large doped area.

    PubMed

    Michaille, L; Bennett, C R; Taylor, D M; Shepherd, T J; Broeng, J; Simonsen, H R; Petersson, A

    2005-07-01

    We report on the laser properties of multicore photonic crystal fiber lasers. A stable phase locking of six- and seven-core structures through evanescent coupling is observed. Effective supermode selection is obtained by using both diffraction losses and the Talbot effect. A pure in-phase supermode is obtained (1.1 times diffraction limited). The laser operating in this mode has a slope efficiency of 70% with up to 44 W of output power. The modal area of the in-phase supermode multicore fiber is 1150 microm2, which makes it, to our knowledge, the single-mode fiber laser with the largest mode field area. In-phase laser action is stable when the fiber is bent. PMID:16075532

  20. Large-scale three-dimensional phase-field simulations for phase coarsening at ultrahigh volume fraction on high-performance architectures

    NASA Astrophysics Data System (ADS)

    Yan, Hui; Wang, K. G.; Jones, Jim E.

    2016-06-01

    A parallel algorithm for large-scale three-dimensional phase-field simulations of phase coarsening is developed and implemented on high-performance architectures. From the large-scale simulations, a new kinetics in phase coarsening in the region of ultrahigh volume fraction is found. The parallel implementation is capable of harnessing the greater computer power available from high-performance architectures. The parallelized code enables increase in three-dimensional simulation system size up to a 5123 grid cube. Through the parallelized code, practical runtime can be achieved for three-dimensional large-scale simulations, and the statistical significance of the results from these high resolution parallel simulations are greatly improved over those obtainable from serial simulations. A detailed performance analysis on speed-up and scalability is presented, showing good scalability which improves with increasing problem size. In addition, a model for prediction of runtime is developed, which shows a good agreement with actual run time from numerical tests.

  1. Large-scale and highly oriented liquid crystal phase in suspensions of polystyrene-block-poly(L-lactide) single crystals.

    PubMed

    Jiang, Chunbo; Wang, Zongbao; Huang, Haiying; He, Tianbai

    2011-04-19

    A large number of lozenge-shaped and sandwiched polystyrene-block-poly(L-lactide) (PS-b-PLLA) single crystals were prepared by the self-seeding technique. The single crystals were nearly monodispersed in both thickness and diameter. They are well-dispersed because of the steric stabilization offered by tethered PS in p-xylene, which is a good solvent for PS. The suspensions were observed to separate into a transparent upper phase and a turbid lower phase. The lower phase showed uniform iridescent stripes extending over the whole tube between crossed polarizers. The birefringence demonstrates the liquid crystal order, and the uniform stripes reveal that the phase is a well-oriented single domain. The phase-transition concentration is rather low. Polarizing light microscopy (PLM) images show Schlieren texture and thread-like texture. Small-angle X-ray scattering (SAXS) results showed that the single crystals in the liquid crystal phase oriented horizontally with a vertical repeat distance of about 70 nm. Additionally, the possible structure of the liquid crystal phase is being discussed. The novel disclike colloidal particle might be useful for anisotropic photonic materials. PMID:21405072

  2. 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.

  3. 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.

  4. Large isotropic negative thermal expansion above a structural quantum phase transition

    SciTech Connect

    Handunkanda, Sahan Uddika; Curry, Erin B.; Voronov, Vladimir; Said, Ayman H.; Guzman-Verri, Gian G.; Brierley, Richard; Littlewood, Peter B.; Hancock, Jason N.

    2015-10-01

    Perovskite structured materials contain myriad tunable ordered phases of electronic and magnetic origin with proven technological importance and strong promise for a variety of energy solutions. An always-contributing influence beneath these cooperative and competing interactions is the lattice, whose physics may be obscured in complex perovskites by the many coupled degrees of freedom which makes these systems interesting. Here we report signatures of an approach to a quantum phase transition very near the ground state of the nonmagnetic, ionic insulating, simple cubic perovskite material ScF3 and show that its physical properties are strongly effected as much as 100 K above the putative transition. Spatial and temporal correlations in the high-symmetry cubic phase determined using energy- and momentum-resolved inelastic X-ray scattering as well as X-ray diffraction reveal that soft mode, central peak and thermal expansion phenomena are all strongly influenced by the transition.

  5. Shock waves and phase changes in a large-heat-capacity fluid emerging from a tube

    NASA Astrophysics Data System (ADS)

    Thompson, P. A.; Kim, Y.-G.; Carofano, G. C.

    1986-05-01

    The emergence of a shockwave from the open end of a shock tube is studied, with special emphasis on test fluids of high molar heat capacity, i.e. retrograde fluids. A variety of wavelike vapour-liquid phase changes are observed in such fluids, including the liquefaction shock, mixture-evaporation shock, condensation waves associated with shock splitting and liquid-evaporation waves (these phenomena have analogues in the polymorphic phase changes of solids; only the first two are treated in this paper). The open end of the shock-tube test section discharges into an observation chamber where photographs of the emerging flow are taken. Calculations were performed with the Benedict-Webb-Rubin, van der Waals and other equations of state. Numerical (finite-difference) predictions of the flow were made for single-phase and two-phase flows: solutions were tested against the experimental shock diffraction and vortex data of Skews. The phase-change properties of the test fluid can be quantified by the 'retrogradicity' r(T), measuring the difference in slope between the P, T isentrope and the vapour-pressure curve, and the 'kink' k(T), measuring the difference between the single-phase and mixture sound speeds. Mixture-evaporation (i.e. rerefaction) shocks appear to have a sonic-sonic or double Chapman-Jouguet structure and show agreement with amplitude predictions based on k(T). Liquefaction shocks are found to show a reproducible transition from regular, smooth shock fronts to irregular, chaotic shock fronts with increasing shock Mach number. This transition can be correlated with published stability limits.

  6. 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

  7. Large-scale three-dimensional phase field simulation of γ '-rafting and creep deformation

    NASA Astrophysics Data System (ADS)

    Zhou, Ning; Shen, Chen; Mills, Michael; Wang, Yunzhi

    2010-01-01

    Three-dimensional phase field simulations of coupled γ/γ ‧ microstructural evolution and plastic deformation in single crystal Ni-Al are carried out at micrometer scales. Coherent γ/γ ‧ microstructures and plastic deformation in γ-channels are described using a single, consistent methodology based on Khachaturyan's phase field microelasticity approach to coherent precipitates and dislocations. In particular, a new set of phase fields is introduced to characterize local density of dislocations from individual active slip systems. To increase the length scale of the phase field simulations, the Kim-Kim-Suzuki (KKS) treatment of γ/γ ‧ interfaces was adopted. The rafting kinetics, precipitate-matrix inversion process and the corresponding creep deformation are characterized with respect to parameters such as applied stress and lattice misfit. The simulation results on γ ‧-rafting kinetics and morphological evolution of the γ/γ ‧ microstructures are compared with available experiment. The model can be used to carry out parametric studies of the effects of material and processing parameters such as alloy composition, external stress and working temperature on γ ‧-rafting kinetics, morphological evolution and the corresponding creep deformation.

  8. 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...

  9. 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

  10. 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.

  11. 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.

  12. 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

    Two phase and gaseous choked flow data for fluid nitrogen were obtained for a test section which was a long constant area duct of 16 200 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 fraction. A simplified theory which in essence decouples the long tube region from the high acceleration choking region also appears to predict the data reasonably well, but about 15 percent low.

  13. 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.

  14. Topological strings and large N phase transitions II: chiral expansion of q-deformed Yang-Mills theory

    NASA Astrophysics Data System (ADS)

    Caporaso, Nicola; Cirafici, Michele; Griguolo, Luca; Pasquetti, Sara; Seminara, Domenico; Szabo, Richard J.

    2006-01-01

    We continue our study of the large N phase transition in q-deformed Yang-Mills theory on the sphere and its role in connecting topological strings to black hole entropy. We study in detail the chiral theory defined in terms of uncoupled single U(N) representations at large N and write down the resulting partition function by means of the topological vertex. The emergent toric geometry has three Kähler parameters, one of which corresponds to the expected fibration over Bbb P1. By taking a suitable double-scaling limit we recover the chiral Gross-Taylor string expansion. To analyse the phase transition we construct a matrix model which describes the chiral gauge theory. It has three distinct phases, one of which should be described by the closed topological string expansion. We verify this expectation by explicit comparison between the matrix model and the chiral topological string free energies. We also show that the critical point in the pertinent phase of the matrix model corresponds to a divergence of the topological string perturbation series.

  15. Nuclear liquid-gas phase transition at large N{sub c} in the van der Waals approximation

    SciTech Connect

    Torrieri, Giorgio; Mishustin, Igor

    2010-11-15

    We examine the nuclear liquid-gas phase transition at a large number of colors (N{sub c}) within the framework of the van der Waals (VdW) We argue that the VdW equation is appropriate for describing internucleon forces, and discuss how each parameter scales with N{sub c}. We demonstrate that N{sub c}=3 (our world) is not large with respect to the other dimensionless scale relevant to baryonic matter, the number of neighbors in a dense system N{sub N}. Consequently, we show that the liquid-gas phase transition looks dramatically different at N{sub c{yields}{infinity}} with respect to our world: The critical-point temperature becomes of the order of {Lambda}{sub QCD} rather than below it. The critical-point density becomes of the order of the baryonic density, rather than an order of magnitude below it. These are precisely the characteristics usually associated with the ''quarkyonic phase.'' We therefore conjecture that quarkyonic matter is simply the large-N{sub c} limit of the nuclear liquid, and the interplay between N{sub c} and N{sub N} is the reason that the nuclear liquid in our world is so different from quarkyonic matter. We conclude by suggesting ways in which our conjecture can be tested in future lattice measurements.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. Catastrophes, phase shifts, and large-scale degradation of a Caribbean coral reef.

    PubMed

    Hughes, T P

    1994-09-01

    Many coral reefs have been degraded over the past two to three decades through a combination of human and natural disturbances. In Jamaica, the effects of overfishing, hurricane damage, and disease have combined to destroy most corals, whose abundance has declined from more than 50 percent in the late 1970s to less than 5 percent today. A dramatic phase shift has occurred, producing a system dominated by fleshy macroalgae (more than 90 percent cover). Immediate implementation of management procedures is necessary to avoid further catastrophic damage.

  1. Long-range order instead of phase separation in large lattice-mismatch isovalent AX-BX systems

    SciTech Connect

    Zhang, Xiuwen; Trimarchi, Giancarlo; d'Avezac, Mayeul; Zunger, Alex

    2009-12-15

    Large atomic size mismatch between compounds discourages their binding into a common lattice because of the ensuing cost in strain energy. This central paradigm in the theory of isovalent alloys long used to disqualify alloys with highly mismatched components from technological use is clearly broken by the occurrence of stable spontaneous long-range order in mixtures of alkali halides with as much as 40% size mismatch (e.g., LiF-CsF). Our theoretical analysis of these failures uncovered a different design principle for stable alloys: very large atomic size mismatch can lead to spontaneous ordering if the large (small) components have the ability to raise (lower) their coordination number (CN) within the mixed phase. This heuristic design principle has led us to explore via first-principles structure search a few very largely mismatched binary systems whose components have a propensity for CN disproportionation. We find ordered structures for BeO-BaO (37% size mismatch) and BeO-SrO (30%), and ordering in LiCl-KCl (20%), whereas BN-InN (33%) is found to lower its positive formation enthalpy by ~60% when CN disproportionation is allowed. This new design principle could be used to explore phases unsuspected to order by the common paradigm of strain instability.

  2. 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. PMID:26027753

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Phase A reaction control system design for the Large Space Telescope (LST)

    NASA Technical Reports Server (NTRS)

    Price, W. B.

    1972-01-01

    The design of a reaction control system (RCS) for the Large Space Telescope is discussed. The primary requirement for the RCS is to serve as an emergency backup control system to the primary attitude control system. A regulated gaseous nitrogen RCS was selected. The operation of the system and its individual components is described. The principal design goals of the RCS were to minimize contamination effects, make use of existing components, and modularize the system to provide ease in manned orbital maintenance.

  8. 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.

  9. Cellular Redistribution of Protein Tyrosine Phosphatases LAR and PTPσ by Inducible Proteolytic Processing

    PubMed Central

    Aicher, Babette; Lerch, Markus M.; Müller, Thomas; Schilling, James; Ullrich, Axel

    1997-01-01

    Most receptor-like protein tyrosine phosphatases (PTPases) display a high degree of homology with cell adhesion molecules in their extracellular domains. We studied the functional significance of processing for the receptor-like PTPases LAR and PTPσ. PTPσ biosynthesis and intracellular processing resembled that of the related PTPase LAR and was expressed on the cell surface as a two-subunit complex. Both LAR and PTPσ underwent further proteolytical processing upon treatment of cells with either calcium ionophore A23187 or phorbol ester TPA. Induction of LAR processing by TPA in 293 cells did require overexpression of PKCα. Induced proteolysis resulted in shedding of the extracellular domains of both PTPases. This was in agreement with the identification of a specific PTPσ cleavage site between amino acids Pro821 and Ile822. Confocal microscopy studies identified adherens junctions and desmosomes as the preferential subcellular localization for both PTPases matching that of plakoglobin. Consistent with this observation, we found direct association of plakoglobin and β-catenin with the intracellular domain of LAR in vitro. Taken together, these data suggested an involvement of LAR and PTPσ in the regulation of cell contacts in concert with cell adhesion molecules of the cadherin/catenin family. After processing and shedding of the extracellular domain, the catalytically active intracellular portions of both PTPases were internalized and redistributed away from the sites of cell–cell contact, suggesting a mechanism that regulates the activity and target specificity of these PTPases. Calcium withdrawal, which led to cell contact disruption, also resulted in internalization but was not associated with prior proteolytic cleavage and shedding of the extracellular domain. We conclude that the subcellular localization of LAR and PTPσ is regulated by at least two independent mechanisms, one of which requires the presence of their extracellular domains and one of

  10. NOVEL CONCEPTS FOR THE COMPRESSION OF LARGE VOLUMES OF CARBON DIOXIDE-PHASE III

    SciTech Connect

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

    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 and tested in a closed loop compressor facility using CO2. Both test programs

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Use of IAEA's phase-space files for virtual source model implementation: Extension to large fields.

    PubMed

    Rucci, Alexis; Carletti, Claudia; Cravero, Walter; Strbac, Bojan

    2016-08-01

    In a previous work, phase-space data files (phsp) provided by the International Atomic Energy Agency (IAEA) were used to develop a hybrid virtual source model (VSM) for clinical photon beams. Very good agreement with dosimetric measurements performed on linear accelerators was obtained for field sizes up to 15×15cm(2). In the present work we extend the VSM to larger field sizes, for which phsp are not available. We incorporate a virtual flattening filter to our model, which can be determined from dose measurements for larger fields. In this way a fully functional VSM can be built, from publicly available IAEA's phsps and standard dose measurements, for fields of any size and tailored to a particular linac. PMID:27423827

  16. Large-scale tectonic features induced by mantle avalanches with phase, temperature, and pressure lateral variations of viscosity

    NASA Astrophysics Data System (ADS)

    Brunei, David; Machetel, Philippe

    1998-03-01

    million years).The temporal evolution of the convection pattern during an avalanche allows us to propose self-consistent mechanisms for slab migration above the 670 km discontinuity for the birth and disappearance of ridges, the rising of powerful plumes from the CMB, and the creation of low-viscosity zones which may act as a lubricant under continents for fast migration. These results show that the main mantle phase changes, combined with temperature and pressure dependent viscosity, induce convective behavior which provides an explanation for most of the past and present large-scale dynamic behavior of the Earth's global tectonics.

  17. Composition design for Laves phase-related BCC-V solid solution alloys with large hydrogen storage capacities

    NASA Astrophysics Data System (ADS)

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

    2008-02-01

    This paper analyzes the alloy composition characteristics with large hydrogen storage capacities in Laves phase-related BCC solid solution alloy systems using the cluster line approach. Since a dense-packed icosahedral cluster A6B7 characterizes the local structure of AB2 Laves phases, in A-B-C ternary system, such as Ti-Cr(Mn, Fe)-V, where A-B forms AB2 Laves phases while A-C and B-C tend to form solid solutions, a cluster line A6B7-C is constructed by linking A6B7 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 (Ti6Cr7)100-xVx (x = 2.5-70 at.%) exhibit different structures and hence different hydrogen storage capacities with increasing V contents. The alloy (Ti6Cr7)95V5 as well as Ti30Cr40V30 with BCC solid solution structure satisfy the cluster-plus-glue-atom model.

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

    NASA Astrophysics Data System (ADS)

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

    2008-03-01

    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 A6B7 characterizes the local structure of AB2 Laves phases, in an A-B-C ternary system, such as Ti-Cr (Mn, Fe)-V, where A-B forms AB2 Laves phases while A-C and B-C tend to form solid solutions, a cluster line A6B7-C is constructed by linking A6B7 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 (Ti6Cr7)100-xVx (x = 2.5-70 at.%) exhibit different structures and hence different hydrogen storage capacities with increasing V content. The alloys (Ti6Cr7)95V5 and Ti30Cr40V30 with bcc solid solution structure satisfy the cluster-plus-glue-atom model.

  19. Large epitaxial bi-axial strain induces a Mott-like phase transition in VO{sub 2}

    SciTech Connect

    Kittiwatanakul, Salinporn; Wolf, Stuart A.; Lu, Jiwei

    2014-08-18

    The metal insulator transition (MIT) in vanadium dioxide (VO{sub 2}) has been an important topic for recent years. It has been generally agreed upon that the mechanism of the MIT in bulk VO{sub 2} is considered to be a collaborative Mott-Peierls transition, however, the effect of strain on the phase transition is much more complicated. In this study, the effect of the large strain on the properties of VO{sub 2} films was investigated. One remarkable result is that highly strained epitaxial VO{sub 2} thin films were rutile in the insulating state as well as in the metallic state. These highly strained VO{sub 2} films underwent an electronic phase transition without the concomitant Peierls transition. Our results also show that a very large tensile strain along the c-axis of rutile VO{sub 2} resulted in a phase transition temperature of ∼433 K, much higher than in any previous report. Our findings elicit that the metal insulator transition in VO{sub 2} can be driven by an electronic transition alone, rather the typical coupled electronic-structural transition.

  20. 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.

  1. Yb-doped large-mode-area laser fiber fabricated by halide-gas-phase-doping technique

    NASA Astrophysics Data System (ADS)

    Peng, Kun; Wang, Yuying; Ni, Li; Wang, Zhen; Gao, Cong; Zhan, Huan; Wang, Jianjun; Jing, Feng; Lin, Aoxiang

    2015-06-01

    In this manuscript, we designed a rare-earth-halide gas-phase-doping setup to fabricate a large-mode-area fiber for high power laser applications. YbCl3 and AlCl3 halides are evaporated, carried respectively and finally mixed with usual host gas material SiCl4 at the hot zone of MCVD system. Owing to the all-gas-phasing reaction process and environment, the home-made Yb-doped fiber preform has a homogeneous large core and modulated refractive index profile to keep high beam quality. The drawn fiber core has a small numerical aperture of 0.07 and high Yb concentration of 9500 ppm. By using a master oscillator power amplifier system, nearly kW-level (951 W) laser output power was obtained with a slope efficiency of 83.3% at 1063.8 nm, indicating the competition and potential of the halide-gas-phase-doping technique for high power laser fiber fabrication.

  2. Large aperture kinoform phase plates in fused silica for spatial beam smoothing on Nova and the Beamlet Lasers

    SciTech Connect

    Rushford, M.C.; Dixit, S.N.; Thomas, I.M.; Martin, A.M.; Perry, M.D.

    1997-03-01

    It is now widely recognized that spatial beam smoothing (homogenization) is essential in coupling the laser energy to the inertial confinement fusion (ICF) targets. For the indirect drive approach to ICF, it is desirable to distribute the laser energy into a uniformly speckled profile that has a flat-top super-Gaussian envelope (8th power or higher) and contains greater than 95% of the energy inside the super-Gaussian profile. Spatial smoothing is easily achieved by introducing a binary random phase plate (RPP) in the beam. This produces a homogenized far-field pattern which consists of an overall envelope function determined by the RPP element superimposed with a fine scale speckle pattern arising due to the interference among the various RPP elements. Although easy to fabricate and currently in routine use in many fusion laboratories, the binary RPPs do not meet the ICF requirements stated above since the far-field intensity profile is restricted to essentially an Airy function containing only 84% (an upper limit) of the energy inside the central spot. Approaches using lenslet arrays (refractive or diffractive) have limited use since they operate in the quasi-far-field and have a short depth of focus. The limitations of the RPPs can be overcome by relaxing the binary phase constraint. We have recently presented 5 continuously varying phase screens for tailoring the focal plane irradiance profiles. Called kinoform phase plates (KPPs), these phase screens offer complete flexibility in tailoring the focal plane envelope and, at the same time, increasing the energy efficiency inside the focal spot. In this paper we discuss the design and fabrication of such kinoform phase plates in fused silica for spatial beam smoothing on the Nova and the Beamlet lasers. Since the phase plates are used at the end of the laser chain, KPPs on Nova and Beamlet have to be fabricated on large aperture optics (65-cm diameter and 40-cm square substrates respectively). The following

  3. 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.

  4. A fast and conformal heating scheme for producing large thermal lesions using a 2D ultrasound phased array.

    PubMed

    Liu, Hao-Li; Lin, Win-Li; Chen, Yung-Yaw

    2007-02-01

    The treatment conformability and the total treatment time of large tumors are both important issues in ultrasound thermal therapy. Previous heating strategies all show their restrictions in achieving these two issues to satisfactory levels simultaneously. This work theoretically presents a new heating strategy which is capable of both increasing the treatment conformability and shortening the treatment time, when using a 2D ultrasound phased array transducer. To perform this, a set of the multiple-foci patterns (considered the basic heating units) were temporally switched to steer the beam at different focal planes with the lesion length being well-controlled. Then, to conformally cover an irregular target volume, the 2D phased array was laterally shifted by a positioning system to deposit a suitable heating unit to cover a subvolume part. Results demonstrated that the totally treatment time can be largely reduced. The heating rate can be increased up to 0.96 cm3/min compared to the previously reported 0.26 cm3/min. Also, the proposed scheme showed that the tumor regions can be completely treated with the normal tissue damage at satisfactory level. The feasibility of the proposed strategy for irregular tumor treatment was also demonstrated. This study offers useful information in large tumor treatment in ultrasound thermal therapy.

  5. Phase and amplitude dynamics in large systems of coupled oscillators: growth heterogeneity, nonlinear frequency shifts, and cluster states.

    PubMed

    Lee, Wai Shing; Ott, Edward; Antonsen, Thomas M

    2013-09-01

    This paper addresses the behavior of large systems of heterogeneous, globally coupled oscillators each of which is described by the generic Landau-Stuart equation, which incorporates both phase and amplitude dynamics of individual oscillators. One goal of our paper is to investigate the effect of a spread in the amplitude growth parameter of the oscillators and of the effect of a homogeneous nonlinear frequency shift. Both of these effects are of potential relevance to recently reported experiments. Our second goal is to gain further understanding of the macroscopic system dynamics at large coupling strength, and its dependence on the nonlinear frequency shift parameter. It is proven that at large coupling strength, if the nonlinear frequency shift parameter is below a certain value, then there is a unique attractor for which the oscillators all clump at a single amplitude and uniformly rotating phase (we call this a single-cluster "locked state"). Using a combination of analytical and numerical methods, we show that at higher values of the nonlinear frequency shift parameter, the single-cluster locked state attractor continues to exist, but other types of coexisting attractors emerge. These include two-cluster locked states, periodic orbits, chaotic orbits, and quasiperiodic orbits.

  6. 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.

  7. An analysis of large Forbush decrease events using phase diagrams of view channels of the Nagoya multidirectional muon telescope

    NASA Astrophysics Data System (ADS)

    Kalugin, G.; Kabin, K.

    2015-02-01

    Large Forbush decrease (FD) events are analysed using data recorded by the ground-based Nagoya multi-directional muon telescope in Japan. As a part of the analysis we introduce a phase diagram for the channels of telescope, which provides more robust information about characteristics of events. Specifically, the slope of the regression line in the phase diagram represents the FD amplitude which can be computed for different channels. This allows us to analyze the dependence of the FD amplitude on the rigidity of CR particles. Two models for this dependence are considered, a power law and exponential and the former is found to be more suitable for the considered events. In terms of the power-law index and the FD amplitude the events are split into two groups. It is shown that the larger events are characterized by smaller power-law index than the smaller ones.

  8. 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.

  9. 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.

  10. Bone-patellar tendon-bone autograft versus LARS artificial ligament for anterior cruciate ligament reconstruction.

    PubMed

    Pan, Xiaoyun; Wen, Hong; Wang, Lide; Ge, Tichi

    2013-10-01

    The optimized graft for use in anterior cruciate ligament (ACL) reconstruction is still in controversy. The bone-patellar tendon-bone (BPTB) autograft has been accepted as the gold standard for ACL reconstruction. However, donor site morbidities cannot be avoided after this treatment. The artificial ligament of ligament advanced reinforcement system (LARS) has been recommended for ACL reconstruction. The purpose of this study is to compare the midterm outcome of ACL reconstruction using BPTB autografts or LARS ligaments. Between July 2004 and March 2006, the ACL reconstruction using BPTB autografts in 30 patients and LARS ligaments in 32 patients was performed. All patients were followed up for at least 4 years and evaluated using the Lysholm knee score, Tegner score, International Knee Documentation Committee (IKDC) score, and KT-1000 arthrometer test. There were no significant differences between the two groups with respect to the data of Lysholm scores, Tegner scores, IKDC scores, and KT-1000 arthrometer test at the latest follow-up. Our study demonstrates that the similarly good clinical results are obtained after ACL reconstruction using BPTB autografts or LARS ligaments at midterm follow-up. In addition to BPTB autografts, the LARS ligament may be a satisfactory treatment option for ACL rupture.

  11. 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.

  12. Direct synthesis of large size ferromagnetic SmCo{sub 5} nanoparticles by a gas-phase condensation method

    SciTech Connect

    He Shihai; Jing Ying; Wang Jianping

    2013-04-07

    Ferromagnetic SmCo{sub 5} nanoparticles with large size have been directly synthesized by a magnetron-sputtering-based gas-phase condensation method. Based on this method, we studied the effect of thermodynamic environment for the growth of SmCo{sub 5} nanoparticles. It was found that the well-crystallized SmCo{sub 5} nanoparticle tends to form a hexagonal disk shape with its easy axis perpendicular to the disk plane. More importantly, under the condition of high sputtering current, well-crystallized nanoparticles were found to be formed through a three-stage growth process: aggregation, coalescence, and second crystallization.

  13. Photoresponse properties of large-area MoS{sub 2} atomic layer synthesized by vapor phase deposition

    SciTech Connect

    Luo, Siwei; Qi, Xiang E-mail: jxzhong@xtu.edu.cn; Ren, Long; Hao, Guolin; Fan, Yinping; Liu, Yundan; Han, Weijia; Zang, Chen; Li, Jun; Zhong, Jianxin E-mail: jxzhong@xtu.edu.cn

    2014-10-28

    Photoresponse properties of a large area MoS{sub 2} atomic layer synthesized by vapor phase deposition method without any catalyst are studied. Scanning electron microscopy, atomic force microscopy, Raman spectrum, and photoluminescence spectrum characterizations confirm that the two-dimensional microstructures of MoS{sub 2} atomic layer are of high quality. Photoelectrical results indicate that the as-prepared MoS{sub 2} devices have an excellent sensitivity and a good reproducibility as a photodetector, which is proposed to be ascribed to the potential-assisted charge separation mechanism.

  14. High resolution, large field of view x-ray differential phase contrast imaging on a compact setup

    SciTech Connect

    Thuering, T.; Stampanoni, M.; Modregger, P.; Grund, T.; Kenntner, J.; David, C.

    2011-07-25

    X-ray grating interferometry is a well established technique to perform differential phase contrast imaging on conventional x-ray tubes. So far, the application of this technique in commercial micro computed tomography scanners has remained a major challenge due to the compact setup geometry. In this letter, we report on the design of a compact imaging setup using a microfocus source. Due to the extreme wave front curvature, the gratings are fabricated on a flexible substrate, enabling precise cylindrical shaping. A laboratory setup and a modified SCANCO {mu}CT100 scanner have been built, allowing high resolution and large field of view imaging.

  15. Development of a modular, large-scale, high-throughput semicontinuous-mode liquid-phase epitaxy system

    NASA Astrophysics Data System (ADS)

    Mauk, M. G.; Shellenbarger, Z. A.; Sims, P. E.; Bloothoofd, W.; McNeely, J. B.; Collins, S. R.; Rabinowitz, P. I.; Hall, R. B.; DiNetta, L. C.; Barnett, A. M.

    2000-04-01

    We describe the design, operation, and performance of a high-throughput, large-scale liquid-phase epitaxy system for producing semiconductor optoelectronic devices. This system operates in a semicontinuous mode with high deposition rates and produces uniform, device-quality AlGaAs epitaxial structures on 75-mm (3″) diameter GaAs substrates. The system has a modular design and can be readily adapted for growth of multilayer heterostructures. This new LPE system represents a two order of magnitude improvement in areal throughput compared to conventional horizontal slideboat systems and has applications for LEDs, thermophotovoltaic devices, solar cells, and detectors.

  16. Large-scale environmental dependence of gas-phase metallicity in dwarf galaxies

    NASA Astrophysics Data System (ADS)

    Douglass, Kelly; Vogeley, Michael S.

    2016-01-01

    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 37 void dwarf galaxies and 71 dwarf galaxies in more dense regions using spectroscopic observations from the Sloan Digital Sky Survey Data Release 7, as re-processed 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 stellar evolution. Of particular interest are a number of extremely metal-poor dwarf galaxies that are equally abundant in both voids and denser regions.

  17. Fabrication and morphologies of large directly ordered L1{sub 0} FePt nanoparticles in gas phase

    SciTech Connect

    Liu Xiaoqi; Wang Jianping

    2009-04-01

    Gas phase synthesis of large directly ordered L1{sub 0} FePt nanoparticles was studied. Simultaneous control of the chemical ordering and the size of the FePt nanoparticle was successfully achieved. It was found that the chemical ordering of the FePt nanoparticles was mainly influenced by the energy conditions (thermal environments at nucleation and growth regions), which could be adjusted by varying the process parameters including the sputtering current density, the Ar gas pressure, etc. The sizes of ordered FePt nanoparticles were more related to the Fe and Pt atoms' density at the initial stage (close to target surface). Multiply twinned structures were observed in L1{sub 0} FePt nanoparticles with 12 and 17 nm mean sizes, but were absent in L1{sub 0} FePt nanoparticles with 6 nm mean size, which caused the relatively low coercivity of large L1{sub 0} FePt nanoparticles.

  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. 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.

  20. 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.

  1. 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.

  2. Gastrointestinal neuroendocrine tumors treated with high dose octreotide-LAR: A systematic literature review

    PubMed Central

    Broder, Michael S; Beenhouwer, David; Strosberg, Jonathan R; Neary, Maureen P; Cherepanov, Dasha

    2015-01-01

    AIM: To review literature on efficacy and safety of octreotide-long-acting repeatable (LAR) used at doses higher than the Food and Drug Administration (FDA)-approved 30 mg/mo for treatment of neuroendocrine tumors (NETs). METHODS: We searched PubMed and Cochrane Library from 1998-2012, 5 conferences (American Society of Clinical Oncology, Endocrine Society, European Neuroendocrine Tumor Society, European Society for Medical Oncology, North American Neuroendocrine Tumor Society) from 2000-2013 using MeSH and keyterms including neuroendocrine tumors, carcinoid tumor, carcinoma, neuroendocrine, and octreotide. Bibliographies of accepted articles were also searched. Two reviewers reviewed titles, abstracts, and full-length articles. Studies that reported data on efficacy and safety of ≥ 30 mg/mo octreotide-LAR for NETs in human subjects, published in any language were included in the review. RESULTS: The search identified 1086 publications, of which 238 underwent full-text review (20 were translated into English); 17 were included in the review. Studies varied in designs, subjects, octreotide-LAR regimens, and definition of outcomes. Eleven studies reported use of higher doses to control symptoms and tumor progression, although symptom severity and formal quality-of-life analysis were not quantitatively measured. Ten studies reported efficacy, describing 260 subjects with doses ranging from 40 mg/mo or 30 mg/3 wk up to 120 mg/mo. Eight studies reported expert clinical opinion that supported dose escalation of octreotide-LAR up to 60 mg/mo for symptom control and suggested increased doses may be effective at preventing tumor progression. Eight studies reported safety; there was no evidence of increased toxicity associated with doses of octreotide-LAR > 30 mg/mo. CONCLUSION: As reported in this review, octreotide-LAR at doses > 30 mg/mo is being prescribed for symptom and tumor control in NET patients. Furthermore, expert clinical opinion provided support for

  3. 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.

  4. Topological strings and large N phase transitions I: Nonchiral expansion of q-deformed Yang-Mills theory

    NASA Astrophysics Data System (ADS)

    Caporaso, Nicola; Cirafici, Michele; Griguolo, Luca; Pasquetti, Sara; Seminara, Domenico; Szabo, Richard J.

    2006-01-01

    We examine the problem of counting bound states of BPS black holes on local Calabi-Yau threefolds which are fibrations over a Riemann surface by computing the partition function of q-deformed Yang-Mills theory on the Riemann surface. We study in detail the genus zero case and obtain, at finite N, the instanton expansion of the gauge theory. It can be written exactly as the partition function for U(N) Chern-Simons gauge theory on a Lens space, summed over all non-trivial vacua, plus a tower of non-perturbative instanton contributions. The correspondence between two and three dimensional gauge theories is elucidated by an explicit mapping between two-dimensional Yang-Mills instantons and flat connections on the Lens space. In the large N limit we find a peculiar phase structure in the model. At weak string coupling the theory reduces exactly to the trivial flat connection sector with instanton contributions exponentially suppressed, and the topological string partition function on the resolved conifold is reproduced in this regime. At a certain critical point all non-trivial vacua contribute, instantons are enhanced and the theory appears to undergo a phase transition into a strong coupling regime. We rederive these results by performing a saddle-point approximation to the exact partition function. We obtain a q-deformed version of the Douglas-Kazakov equation for two-dimensional Yang-Mills theory on the sphere, whose one-cut solution below the transition point reproduces the resolved conifold geometry. Above the critical point we propose a two-cut solution that should reproduce the chiral-antichiral dynamics found for black holes on the Calabi-Yau threefold and the Gross-Taylor string in the undeformed limit. The transition from the strong coupling phase to the weak coupling phase appears to be of third order.

  5. 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.

  6. 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.

  7. Further Investigation into the Seismic Nucleation Phase of Large Earthquakes with a Focus on Strike-Slip Events

    NASA Astrophysics Data System (ADS)

    Burkhart, E.; Ji, C.

    2012-12-01

    The dynamic motion of an earthquake begins abruptly, but is often initiated by a small interval of weak motion called the seismic nucleation phase (SNP), first named by Ellsworth and Beroza (1995). In their study, Ellsworth and Beroza (1995, 1996) concluded that the SNP was detectable in near-source records of all of the 41 M 1 to M 8 earthquakes they investigated, with the SNP accounting for ~0.5% of the total moment and lasting ~1/6 of the total duration. Concentrating on large earthquakes, Ji et al (2010) investigated the SNP of 19 M 8.0 earthquakes since 1994 using a new approach applied to teleseismic broadband data. They found that ~50% of the earthquakes had a detectable SNP. Burkhart and Ji (2011) found that, in 68 M 7.5 to M 8.0 since 1994, the SNP is clearly detectable in 31 events, with 27 events showing no nucleation phase and 10 having too much noise or not enough stations to tell. After making modifications to the stacking code allowing for more specific station choice, these earthquakes have all been re-examined, and a consistent finding is that strike-slip earthquakes are more likely to exhibit a clear SNP than normal or thrust earthquakes. Continuing to investigate these events, this study finds further conclusive evidence that large shallow, continental, and strike-slip earthquakes show a clear SNP. We find that 11 of the 15 strike-slip earthquakes investigated show a clear SNP, with three having none (including the 2002 Mw 7.8 Denali Fault earthquake, which initiated as a thrust subevent), and one with not enough stations to perform stacking.

  8. 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.

  9. Positive magnetoresistance and large magnetostriction at first-order antiferro ferromagnetic phase transitions in RMn2Si2 compounds

    NASA Astrophysics Data System (ADS)

    Gerasimov, E. G.; Mushnikov, N. V.; Koyama, K.; Kanomata, T.; Watanabe, K.

    2008-11-01

    The magnetostriction and magnetoresistance associated with the field-induced and spontaneous first-order antiferro-ferromagnetic (AF-F) phase transitions have been studied for quasi-single-crystalline samples of La0.25Sm0.75Mn2Si2, La0.25Y0.75Mn2Si2 and La0.27Y0.73Mn2Si2 compounds with natural layered ThCr2Si2-type structure. It was found that both the spontaneous and field-induced AF-F transitions are accompanied by a large volume magnetostriction ΔV/V≈2 × 10-3 and anisotropic linear changes of the lattice parameters Δa/a≈1.6 × 10-3, Δc/c≈-0.75 × 10-3. The field-induced AF-F magnetic phase transition has been observed in magnetic fields applied both along the c-axis and in the basal plane, and the magnetostriction value is virtually independent of the direction of applied field. It has been found also that the magnetoresistance is positive in these compounds (the value of the electrical resistance in the ferromagnetic state is higher than that in the antiferromagnetic state) for the fields applied both along the c-axis and in the basal plane. The value of the magnetoresistance observed along the c-axis is 30 times as high as that in the basal plane. The obtained results indicate that the electronic band structure changes are likely responsible for the AF-F magnetic phase transitions observed in the RMn2X2 compounds.

  10. Large-eddy simulation of three mixed-phase cloud events during ISDAC: Conditions for persistent heterogeneous ice formation

    NASA Astrophysics Data System (ADS)

    Savre, J.; Ekman, A. M. L.

    2015-08-01

    A Classical-Nucleation-Theory-based parameterization for heterogenous ice nucleation, including explicit dependencies of the nucleation rates on the number concentration, size, and composition of the ambient aerosol population, is implemented in a cloud-scale, large-eddy simulation model and evaluated against Arctic mixed-phase cloud events observed during Indirect and Semi-Direct Aerosol Campaign (ISDAC). An important feature of the parameterization is that the ice nucleation efficiency of each considered aerosol type is described using a contact angle distribution which evolves with time so that the model accounts for the inhibition of ice nucleation as the most efficient ice-forming particles are nucleated and scavenged. The model gives a reasonable representation of first-order (ice water paths) and second-order (ice crystal size distributions) ice microphysical properties. The production of new ice crystals in the upper part of the cloud, essential to guarantee sustained mixed-phase conditions, is found to be controlled mostly by the competition between radiative cooling (resulting in more aerosol particles becoming efficient ice nuclei as the temperature decreases), cloud-top entrainment (entraining fresh particles into the cloud), and nucleation scavenging of the ice+forming aerosol particles. The relative contribution of each process is mostly determined by the cloud-top temperature and the entrainment rates. Accounting for the evolution of the contact angle probability density function with time seems to be essential to capture the persistence of in-cloud ice production without having to, for example, increase the free tropospheric aerosol concentration. Although limited to only three cases and despite important limitations of the parameterization (e.g., the present version only considers dust and black carbon as potential ice nuclei), the results suggest that modeling the time evolution of the ice nuclei population ability to form ice is required to

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

    PubMed

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

    2015-09-01

    An analysis method for unfolding the spatially resolved wave-number spectrum and phase velocity from the 2D CO2 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. PMID:26429439

  12. Large-scale cubic InN nanocrystals by a combined solution- and vapor-phase method under silica confinement.

    PubMed

    Chen, Zhuo; Li, Yanan; Cao, Chuanbao; Zhao, Songrui; Fathololoumi, Saeed; Mi, Zetian; Xu, Xingyan

    2012-01-18

    Large-scale cubic InN nanocrystals were synthesized by a combined solution- and vapor-phase method under silica confinement. Nearly monodisperse cubic InN nanocrystals with uniform spherical shape were dispersed stably in various organic solvents after removal of the silica shells. The average size of InN nanocrystals is 5.7 ± 0.6 nm. Powder X-ray diffraction results indicate that the InN nanocrystals are of high crystallinity with a cubic phase. X-ray photoelectron spectroscopy and energy-dispersive spectroscopy confirm that the nanocrystals are composed of In and N elements. The InN nanocrystals exhibit infrared photoluminescence at room temperature, with a peak energy of ~0.62 eV, which is smaller than that of high-quality wurtzite InN (~0.65-0.7 eV) and is in agreement with theoretical calculations. The small emission peak energy of InN nanocrystals, as compared to other low-cost solution or vapor methods, reveals the superior crystalline quality of our samples, with low or negligible defect density. This work will significantly promote InN-based applications in IR optoelectronic device and biology. PMID:22224725

  13. 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.

  14. Performance of large aperture tapered fiber phase conjugate mirror with high pulse energy and 1-kHz repetition rate.

    PubMed

    Zhao, Zhigang; Dong, Yantao; Pan, Sunqiang; Liu, Chong; Chen, Jun; Tong, Lixin; Gao, Qingsong; Tang, Chun

    2012-01-16

    A large aperture fused silica tapered fiber phase conjugate mirror is presented with a maximum 70% stimulated Brillouin scattering (SBS) reflectivity, which is obtained with 1 kHz repetition rate, 15 ns pulse width and 38 mJ input pulse energy. To the best of our knowledge, this is the highest SBS reflectivity ever reported by using optical fiber as a phase conjugate mirror for such high pulse repetition rate (1 kHz) and several tens of millijoule (mJ) input pulse energy. The influences of fiber end surface quality and pump pulse widths on SBS reflectivity are investigated experimentally. The results show that finer fiber end surface quality and longer input pulse widths are preferred for obtaining higher SBS reflectivity with higher input pulse energy. Double passing amplification experiments are also performed. 52 mJ pulse energy is achieved at 1 kHz repetition rate, with a reflected SBS pulse width of 1.5 ns and a M(2) factor of 2.3. The corresponding peak power reaches 34.6 MW. Obvious beam quality improvement is observed. PMID:22274534

  15. 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…

  16. SER-LARS, Volume 9. Resource Volume on Test Information. 1975-76 Edition.

    ERIC Educational Resources Information Center

    Montgomery County Intermediate Unit 23, Blue Bell, PA.

    The ninth volume in the SER-LARS (Special Education Resources Location Analysis and Retrieval System) series, a diagnostic-prescriptive instructional data bank for teachers of the handicapped, presents information on tests used for measuring intelligence and mental maturity; general achievement/readiness; reading; mathematics;…

  17. SER-LARS, Volume 2. Learning Objective History I. 1975-76 Edition.

    ERIC Educational Resources Information Center

    Montgomery County Intermediate Unit 23, Blue Bell, PA.

    The second 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. The volume is explained to give a history of the use of each objective along…

  18. SER-LARS, Volume 10. Instructional Methods I. 1975-76 Edition.

    ERIC Educational Resources Information Center

    Montgomery County Intermediate Unit 23, Blue Bell, PA.

    The book briefly describes several hundred instructional methods from the Special Education Resources Location Analysis and Retrieval System (SER-LARS), which are intended for use in developing and carrying out individualized programs for handicapped children. Each teaching method includes an accession number; title; author; source; teacher tasks;…

  19. SER-LARS, Volume 12. Instructional Methods III. 1975-76 Edition.

    ERIC Educational Resources Information Center

    Montgomery County Intermediate Unit 23, Blue Bell, PA.

    The book briefly describes several hundred instructional methods from the Special Education Resources Location Analysis and Retrieval System (SER-LARS), which are intended for use in developing and carrying out individualized programs for handicapped children. Each teaching method includes an accession number; title; author; source; teacher tasks;…

  20. SER-LARS, Volume 11. Instructional Methods II. 1975-76 Edition.

    ERIC Educational Resources Information Center

    Montgomery County Intermediate Unit 23, Blue Bell, PA.

    The book briefly describes several hundred instructional methods from the Special Education Resources Location Analysis and Retrieval System (SER LARS), which are intended for use in developing and carrying out individualized programs for handicapped children. Each teaching method includes an accession number; title; author; source; teacher tasks;…

  1. 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. PMID:26824565

  2. 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.

  3. 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.

  4. Intercomparison of large-eddy simulations of Arctic mixed-phase clouds: Importance of ice size distribution assumptions

    NASA Astrophysics Data System (ADS)

    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

    2014-03-01

    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.

  5. 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.

  6. 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.

  7. 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. PMID:25554028

  8. 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.

  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. Large-eddy simulation of contrail evolution in the vortex phase and its interaction with atmospheric turbulence

    NASA Astrophysics Data System (ADS)

    Picot, J.; Paoli, R.; Thouron, O.; Cariolle, D.

    2015-07-01

    In this work, the evolution of contrails in the vortex and dissipation regimes is studied by means of fully three-dimensional large-eddy simulation (LES) coupled to a Lagrangian particle tracking method to treat the ice phase. In this paper, fine-scale atmospheric turbulence is generated and sustained by means of a stochastic forcing that mimics the properties of stably stratified turbulent flows as those occurring in the upper troposphere and lower stratosphere. The initial flow field is composed of the turbulent background flow and a wake flow obtained from separate LES of the jet regime. Atmospheric turbulence is the main driver of the wake instability and the structure of the resulting wake is sensitive to the intensity of the perturbations, primarily in the vertical direction. A stronger turbulence accelerates the onset of the instability, which results in shorter contrail descent and more effective mixing in the interior of the plume. However, the self-induced turbulence that is produced in the wake after the vortex breakup dominates over background turbulence until the end of the vortex regime and controls the mixing with ambient air. This results in mean microphysical characteristics such as ice mass and optical depth that are slightly affected by the intensity of atmospheric turbulence. However, the background humidity and temperature have a first-order effect on the survival of ice crystals and particle size distribution, which is in line with recent studies.

  11. A study on the characteristics of upward air-water two-phase flow in a large diameter pipe

    SciTech Connect

    Shen, Xiuzhong; Saito, Yasushi; Mishima, Kaichiro; Nakamura, Hideo

    2006-10-15

    An adiabatic upward co-current air-water two-phase flow in a vertical large diameter pipe (inner diameter, D: 0.2m, ratio of pipe length to diameter, L/D: 60.5) was experimentally investigated under various inlet conditions. Flow regimes were visually observed, carefully analyzed and classified into five, i.e. undisturbed bubbly, agitated bubbly, churn bubbly, churn slug and churn froth. Void fraction, bubble frequency, Sauter mean diameter, interfacial area concentration (IAC) and interfacial direction were measured with four-sensor optical probes. Both the measured void fraction and the measured IAC demonstrated radial core-peak distributions in most of the flow regimes and radial wall peak in the undisturbed bubbly flow only. The bubble frequency also showed a wall-peak radial distribution only when the bubbles were small in diameter and the flow was in the undisturbed bubbly flow. The Sauter mean diameter of bubbles did not change much in the radial direction in undisturbed bubbly, agitated bubbly and churn bubbly flows and showed a core-peak radial distribution in the churn slug flow due to the existence of certain amount of large and deformed bubbles in this flow regime. The measurements of interfacial direction showed that the main and the secondary bubbly flow could be displayed by the main flow peak and the secondary flow peak, respectively, in the probability density function (PDF) of the interfacial directional angle between the interfacial direction and the z-axis, {eta}{sub zi}. The local average {eta}{sub zi }at the bubble front or rear hemisphere ({eta}{sub zi}{sup F} and {eta}{sub zi}{sup R}) reflected the local bubble movement and was in direct connection with the flow regimes. Based on the analysis, the authors classified the flow regimes in the vertical large diameter pipe quantitatively by the cross-sectional area-averaged {eta}{sub zi }at bubbly front hemisphere ({eta}{sub zi}{sup F}-bar). Bubbles in the undisturbed bubbly flow moved in a

  12. Two-phase convection in the high-pressure ice layer of the large icy moons: geodynamical implications

    NASA Astrophysics Data System (ADS)

    Kalousova, K.; Sotin, C.; Tobie, G.; Choblet, G.; Grasset, O.

    2015-12-01

    The H2O layers of large icy satellites such as Ganymede, Callisto, or Titan probably include a liquid water ocean sandwiched between the deep high-pressure ice layer and the outer ice I shell [1]. It has been recently suggested that the high-pressure ice layer could be decoupled from the silicate core by a salty liquid water layer [2]. However, it is not clear whether accumulation of liquids at the bottom of the high-pressure layer is possible due to positive buoyancy of water with respect to high-pressure ice. Numerical simulation of this two-phase (i.e. ice and water) problem is challenging, which explains why very few studies have self-consistently handled the presence and transport of liquids within the solid ice [e.g. 3]. While using a simplified description of water production and transport, it was recently showed in [4] that (i) a significant fraction of the high-pressure layer reaches the melting point and (ii) the melt generation and its extraction to the overlying ocean significantly influence the global thermal evolution and interior structure of the large icy moons.Here, we treat the high-pressure ice layer as a compressible mixture of solid ice and liquid water [5]. Several aspects are investigated: (i) the effect of the water formation on the vigor of solid-state convection and its influence on the amount of heat that is transferred from the silicate mantle to the ocean; (ii) the fate of liquids within the upper thermal boundary layer - whether they freeze or reach the ocean; and (iii) the effect of salts and volatile compounds (potentially released from the rocky core) on the melting/freezing processes. Investigation of these aspects will allow us to address the thermo-chemical evolution of the internal ocean which is crucial to evaluate the astrobiological potential of large icy moons. This work has been performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. [1] Hussmann et al. (2007), Treatise of

  13. 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.

  14. 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.

  15. Magnetohydrodynamic stability at the edge region in H-mode plasmas with long edge-localized-mode-free phases in the large helical device

    NASA Astrophysics Data System (ADS)

    Toi, K.; Ohdachi, S.; Ueda, R.; Watanabe, K. Y.; Nicolas, T.; Suzuki, Y.; Ogawa, K.; Tanaka, K.; Takemura, Y.; LHD Experiment Group

    2016-09-01

    Clear suppression of magnetic fluctuations associated with resistive interchange modes (RICs) is observed during long edge-localized-mode (ELM)-free phases of the H-mode plasma in an outward-shifted configuration of the Large Helical Decice, in which a steep pressure gradient is generated at the plasma edge in the magnetic hill. The ELM-free H-phase is interrupted by large amplitude ELMs which are thought to be induced through nonlinear evolution of the RICs having m  =  1/n  =  1 dominant component (m: poloidal mode number, n: toroidal one). The m  =  1/n  =  1 RIC amplitude is enhanced about 10 times compared with the H-phase level during each ELM. In most of the H-mode shots, the final ELM-free phase returns to L-phase by a large amplitude ELM. In the L-phase, the RIC amplitude is enhanced by a factor of ~3 compared with that in the H-phase, although the edge pressure gradient is reduced considerably. Linear resistive magnetohydrodynamic stability analysis is attempted using experimentally obtained equilibrium profiles. From the numerical analysis, the distance between the location of the steepest pressure gradient and the main mode resonance surface, i.e. the rotational transform ι  =  1, is found to be important for a large growth of the m  =  1/n  =  1 RIC in the H-phase.

  16. Application of SDSM and LARS-WG for simulating and downscaling of rainfall and temperature

    NASA Astrophysics Data System (ADS)

    Hassan, Zulkarnain; Shamsudin, Supiah; Harun, Sobri

    2014-04-01

    Climate change is believed to have significant impacts on the water basin and region, such as in a runoff and hydrological system. However, impact studies on the water basin and region are difficult, since general circulation models (GCMs), which are widely used to simulate future climate scenarios, do not provide reliable hours of daily series rainfall and temperature for hydrological modeling. There is a technique named as "downscaling techniques", which can derive reliable hour of daily series rainfall and temperature due to climate scenarios from the GCMs output. In this study, statistical downscaling models are used to generate the possible future values of local meteorological variables such as rainfall and temperature in the selected stations in Peninsular of Malaysia. The models are: (1) statistical downscaling model (SDSM) that utilized the regression models and stochastic weather generators and (2) Long Ashton research station weather generator (LARS-WG) that only utilized the stochastic weather generators. The LARS-WG and SDSM models obviously are feasible methods to be used as tools in quantifying effects of climate change condition in a local scale. SDSM yields a better performance compared to LARS-WG, except SDSM is slightly underestimated for the wet and dry spell lengths. Although both models do not provide identical results, the time series generated by both methods indicate a general increasing trend in the mean daily temperature values. Meanwhile, the trend of the daily rainfall is not similar to each other, with SDSM giving a relatively higher change of annual rainfall compared to LARS-WG.

  17. 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.

  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. Phase 2 study of panobinostat with or without rituximab in relapsed diffuse large B-cell lymphoma

    PubMed Central

    Nielsen, Torsten Holm; Yu, Stephen; Alcaide, Miguel; Chong, Lauren; MacDonald, David; Tosikyan, Axel; Kukreti, Vishal; Kezouh, Abbas; Petrogiannis-Haliotis, Tina; Albuquerque, Marco; Fornika, Daniel; Alamouti, Sepideh; Froment, Remi; Greenwood, Celia M. T.; Oros, Kathleen Klein; Camglioglu, Errol; Sharma, Ayushi; Christodoulopoulos, Rosa; Rousseau, Caroline; Johnson, Nathalie; Crump, Michael; Morin, Ryan D.; Mann, Koren K.

    2016-01-01

    The majority of diffuse large B-cell lymphoma (DLBCL) tumors contain mutations in histone-modifying enzymes (HMEs), indicating a potential therapeutic benefit of histone deacetylase inhibitors (HDIs), and preclinical data suggest that HDIs augment the effect of rituximab. In this randomized phase 2 study, we evaluated the response rate and toxicity of panobinostat, a pan-HDI administered 30 mg orally 3 times weekly, with or without rituximab, in 40 patients with relapsed or refractory de novo (n = 27) or transformed (n = 13) DLBCL. Candidate genes and whole exomes were sequenced in relapse tumor biopsies to search for molecular correlates, and these data were used to quantify circulating tumor DNA (ctDNA) in serial plasma samples. Eleven of 40 patients (28%) responded to panobinostat (95% confidence interval [CI] 14.6-43.9) and rituximab did not increase responses. The median duration of response was 14.5 months (95% CI 9.4 to “not reached”). At time of data censoring, 6 of 11 patients had not progressed. Of the genes tested for mutations, only those in MEF2B were significantly associated with response. We detected ctDNA in at least 1 plasma sample from 96% of tested patients. A significant increase in ctDNA at day 15 relative to baseline was strongly associated with lack of response (sensitivity 71.4%, specificity 100%). We conclude that panobinostat induces very durable responses in some patients with relapsed DLBCL, and early responses can be predicted by mutations in MEF2B or a significant change in ctDNA level at 15 days after treatment initiation. This clinical trial was registered at www.ClinicalTrials.gov (#NCT01238692). PMID:27166360

  20. 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.

  1. Large-field high-contrast hard x-ray Zernike phase-contrast nano-imaging beamline at Pohang Light Source

    NASA Astrophysics Data System (ADS)

    Lim, Jun; Park, So Yeong; Huang, Jung Yun; Han, Sung Mi; Kim, Hong-Tae

    2013-01-01

    We developed an off-axis-illuminated zone-plate-based hard x-ray Zernike phase-contrast microscope beamline at Pohang Light Source. Owing to condenser optics-free and off-axis illumination, a large field of view was achieved. The pinhole-type Zernike phase plate affords high-contrast images of a cell with minimal artifacts such as the shade-off and halo effects. The setup, including the optics and the alignment, is simple and easy, and allows faster and easier imaging of large bio-samples.

  2. Large-field high-contrast hard x-ray Zernike phase-contrast nano-imaging beamline at Pohang Light Source.

    PubMed

    Lim, Jun; Park, So Yeong; Huang, Jung Yun; Han, Sung Mi; Kim, Hong-Tae

    2013-01-01

    We developed an off-axis-illuminated zone-plate-based hard x-ray Zernike phase-contrast microscope beamline at Pohang Light Source. Owing to condenser optics-free and off-axis illumination, a large field of view was achieved. The pinhole-type Zernike phase plate affords high-contrast images of a cell with minimal artifacts such as the shade-off and halo effects. The setup, including the optics and the alignment, is simple and easy, and allows faster and easier imaging of large bio-samples. PMID:23387659

  3. 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.

  4. Enhancement of phase space density by increasing trap anisotropy in a magneto-optical trap with a large number of atoms.

    PubMed

    Vengalattore, M; Conroy, R S; Prentiss, M G

    2004-05-01

    The phase space density of dense, cylindrical clouds of atoms in a 2D magneto-optic trap is investigated. For a large number of trapped atoms (>10(8)), the density of a spherical cloud is limited by photon reabsorption. However, as the atom cloud is deformed to reduce the radial optical density, the temperature of the atoms decreases due to the suppression of multiple scattering leading to an increase in the phase space density. A density of 2 x 10(-4) has been achieved in a magneto-optic trap containing 2 x 10(8) atoms.

  5. Pituitary tumor disappearance in a patient with newly diagnosed acromegaly primarily treated with octreotide LAR.

    PubMed

    Resmini, E; Murialdo, G; Giusti, M; Boschetti, M; Minuto, F; Ferone, D

    2005-02-01

    We describe the case of an acromegalic patient primarily treated with octreotide LAR in whom the pituitary tumor disappeared after 18 months of treatment. A 68-yr-old woman, with clinical suspicion of acromegaly, was admitted to our Unit with the ultrasonographical evidence of cardiac hypertrophy, arrhythmias, right branch block and interatrial septum aneurism. She referred hands and feet enlargement since the age of 30 and facial disfigurements since the age of 50. At the age of 45 she underwent surgery for carpal tunnel syndrome and at the age of 61 an euthyroid nodular goiter was diagnosed. Hormonal evaluation showed elevated circulating GH levels (25+/-3.2 ng/ml), not suppressible after oral glucose load, and elevated IGF-I levels (646 ng/ml), whereas the remaining pituitary function was normal. Visual perimetry was normal, whereas magnetic resonance imaging (MRI) showed an intrasellar pituitary adenoma with maximal diameter of 9 mm. In order to improve cardiovascular function before surgery, the patient started octreotide LAR 20 mg every 4 weeks for 3 months. Then based on IGF-I values, the dose was adjusted to 30 mg. After 6 months a second MRI showed significant tumor reduction (>50% of baseline maximal diameter), GH and IGF-I were within the normal range and the patient continued the treatment. After one-year therapy, an improvement of cardiac alterations was recorded and the patient was referred to the neurosurgeon. However, she refused the operation. At 18-month follow-up, MRI showed the complete disappearance of direct and indirect signs of pituitary adenoma. To our knowledge, this is the first case of complete radiological remission of pituitary tumor during octreotide LAR treatment in acromegaly.

  6. 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.

  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. 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).

  11. 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.

  12. 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.

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

    PubMed

    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.

  14. 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.

  15. 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.

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

    PubMed

    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. PMID:27627362

  17. Dual-domain microchip-based process for volume reduction solid phase extraction of nucleic acids from dilute, large volume biological samples.

    PubMed

    Reedy, Carmen R; Hagan, Kristin A; Strachan, Briony C; Higginson, Joshua J; Bienvenue, Joan M; Greenspoon, Susan A; Ferrance, Jerome P; Landers, James P

    2010-07-01

    A microfluidic device was developed to carry out integrated volume reduction and purification of nucleic acids from dilute, large volume biological samples commonly encountered in forensic genetic analysis. The dual-phase device seamlessly integrates two orthogonal solid-phase extraction (SPE) processes, a silica solid phase using chaotrope-driven binding and an ion exchange phase using totally aqueous chemistry (chitosan phase), providing the unique capability of removing polymerase chain reaction (PCR) inhibitors used in silica-based extractions (guanidine and isopropanol). Nucleic acids from a large volume sample are shown to undergo a substantial volume reduction on the silica phase, followed by a more stringent extraction on the chitosan phase. The key to interfacing the two steps is mixing of the eluted nucleic acids from the first phase with loading buffer which is facilitated by flow-mediated mixing over a herringbone mixing region in the device. The complete aqueous chemistry associated with the second purification step yields a highly concentrated PCR-ready eluate of nucleic acids devoid of PCR inhibitors that are reagent-based (isopropanol) and sample-based (indigo dye), both of which are shown to be successfully removed using the dual-phase device but not by the traditional microfluidic SPE (muSPE). The utility of the device for purifying DNA was demonstrated with dilute whole blood, dilute semen, a semen stain, and a blood sample inhibited with indigo dye, with the resultant DNA from all shown to be PCR amplifiable. The same samples purified using muSPE were not all PCR amplifiable due to a smaller concentration of the DNA and the lack of PCR-compatible aqueous chemistry in the extraction method. The utility of the device for the purification of RNA was also demonstrated, by the extraction of RNA from a dilute semen sample, with the resulting RNA amplified using reverse transcription (RT)-PCR. The vrSPE-SPE device reliably yields a volume reduction for

  18. 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).

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

    DOE PAGES

    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 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

  20. [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.

  1. Large-eddy simulation study of contrail microphysics and geometry during the vortex phase and consequences on contrail-to-cirrus transition

    NASA Astrophysics Data System (ADS)

    Unterstrasser, S.

    2014-06-01

    Large-eddy simulations (LES) with Lagrangian ice microphysics were used to study the early contrail evolution during the vortex phase. Microphysical and geometrical properties of a contrail produced by a large-sized aircraft (type B777/A340) were investigated systematically for a large parameter range. Crystal loss due to adiabatic heating in the downward moving vortices was found to depend strongly on relative humidity and temperature, qualitatively similar to previous 2-D simulation results. Contrail depth is as large as 450 m for the investigated parameter range and was found to be underestimated in a previous 2-D study. Further sensitivity studies show a nonnegligible effect of the initial ice crystal size distribution and the initial ice crystal number on the crystal loss, whereas the contrail structure and ice mass evolution is only barely affected by these variations. Variation of fuel flow has the smallest effect on crystal loss. At high supersaturations, our choice of contrail spatial initialization may underestimate the ice crystal loss. The set of presented sensitivity studies is a first step toward a quantitative description of young contrails in terms of vertical extent and crystal loss. Concluding contrail-to-cirrus simulations demonstrate the relevance of vortex phase processes and its three-dimensional modeling on the later contrail-cirrus properties.

  2. Feasibility of Using Lateral Mode Coupling Method for a Large Scale Ultrasound Phased Array for Noninvasive Transcranial Therapy

    PubMed Central

    Song, Junho; Hynynen, Kullervo

    2009-01-01

    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/cm2. 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. PMID:19695987

  3. Catalytic domains of the LAR and CD45 protein tyrosine phosphatases from Escherichia coli expression systems: Purification and characterization for specificity and mechanism

    SciTech Connect

    Cho, Hyeongjin; Ramer, S.E.; Itoh, Michiyasu; Saito, Haruo; Walsh, C.T. ); Kitas, E.; Bannwarth, W.; Burn, P. )

    1992-01-14

    The cytoplasmic domains of two human transmembrane protein tyrosine phosphatases (PTPases), LAR and CD45, have been expressed in Escherichia coli, purified to near-homogeneity, and compared for catalytic efficiency toward several phosphotyrosine-containing peptide substrates. A 615-residue LAR fragment (LAR-D1D2) containing both tandemly repeated PTPase domains shows almost identical specific activity and high catalytic efficiency as the 40-kDa single-domain LAR-D1 fragment, consistent with a single functional active site in the 70-kDa LAR-D1D2 enzyme. A 90-kDa fragment of the human leukocyte CD45 PTPase, containing two similar tandemly repeated PTPase domains, shows parallel specificity to LAR-D1 and LAR-D1D2 with a high k{sub cat}/K{sub M} value for a phosphotyrosyl undecapeptide. Sufficient purified LAR-D1 and LAR-D1D2 PTPases were available to demonstrate enzymatic exchange of {sup 18}O from {sup 18}O{sub 4} inorganic phosphate into H{sub 2} {sup 16}O at rates of {approximately}1 {times} 10{sup {minus}2} s{sup {minus}1}. The oxygen-18 exchange probably proceeds via a phosphoenzyme intermediate. Brief incubation of all three PTPase fragments with a ({sup 32}P)phosphotyrosyl peptide substrate prior to quench with SDS sample buffer and gel electrophoresis led to autoradiographic detection of {sup 32}P-labeled enzymes. Pulse/chase studies on the LAR {sup 32}P-enzyme showed turnover of the labeled phosphoryl group.

  4. Expression levels of a LAR-like receptor protein tyrosine phosphatase correlate with neuronal branching and arbor density in the medicinal leech.

    PubMed

    Baker, Michael W; Macagno, Eduardo R

    2010-08-01

    LAR-like receptor protein tyrosine phosphatases (RPTPs), which are reported to be highly expressed in the nervous systems of most bilaterian animals, have been implicated in the regulation of critical developmental processes, such as neuronal pathfinding, cell adhesion and synaptogenesis. Here we report that two LAR-like RPTPs in the medicinal leech, HmLAR1 and HmLAR2, play roles in regulating the size and density of neuronal arbors within the developing nervous system and in the body wall. Employing single-cell RNAi knockdown and transgene expression techniques, we demonstrate that the expression level of HmLAR1 is directly correlated with the density of an identified neuron's arborization. Knocking down HmLAR1 mRNA levels in the mechanosensory pressure (P) neurons produces a reduced central arbor and a smaller arbor in the peripheral body wall, with fewer terminal branches. By contrast, overexpression of this receptor in a P cell leads to extensive neuronal sprouting, including many supernumerary neurites and terminal branches as well as, in some instances, the normal monopolar morphology of the P cell becoming multipolar. We also report that induced neuronal sprouting requires the expression of the receptor's membrane tethered ectodomain, including the NH(2)-Ig domains, but not of the intracellular phosphatase domains of the receptor. Interestingly, sprouting could be elicited upon ectopic expression of HmLAR1 and the related RPTP, HmLAR2 in the P and other neurons, including those that do not normally express either RPTP, suggesting that the substrates involved in HmLAR-induced sprouting are present in most neurons irrespective of whether they normally express these LAR-like RPTPs. Our data are consistent with the hypothesis that the receptors' ectodomains promote an adhesive interaction that enhances the maintenance of new processes.

  5. Large-Scale Experimental Study of a Phase Change Material: Shape Identification for the Solid-Liquid Interface

    NASA Astrophysics Data System (ADS)

    Kadri, Soumaya; Dhifaoui, Belgacem; Dutil, Yvan; Jabrallah, Sadok Ben; Rousse, Daniel R.

    2015-11-01

    This study describes the development of an experimental setup that tracks the evolution of the melting and freezing fronts of a Phase Change Material (PCM), in this case paraffin. The results obtained enable the examination of the shape and movement of the melting front of the PCM. Two modes of heat transfer were identified during the melting process: conduction when melting began and natural convection, which becomes dominant in the remainder of the cycle. Monitoring of the melt over time shows that the melt fraction, expressed as the ratio of the molten volume and solid volume, is proportional to the difference between the imposed temperature and the melting temperature. Experimental results confirm the linearity proposed by other researchers.

  6. 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.

  7. Large piezoelectric response of BiFeO3/BaTiO3 polycrystalline films induced by the low-symmetry phase.

    PubMed

    Hou, Y F; Li, W L; Zhang, T D; Wang, W; Cao, W P; Liu, X L; Fei, W D

    2015-05-01

    BaTiO3, BiFeO3 and BiFeO3/BaTiO3 polycrystalline films were prepared by the radio frequency magnetron sputtering on the Pt/Ti/SiO2/Si substrate. The phase structure, converse piezoelectric coefficient and domain structure of BaTiO3, BiFeO3 and BiFeO3/BaTiO3 thin films are characterized by XRD and PFM, respectively. The converse piezoelectric coefficient d33 of BiFeO3/BaTiO3 thin films is 119.5 pm V(-1), which is comparable to that of lead-based piezoelectric films. The large piezoelectric response of BiFeO3/BaTiO3 thin films is ascribed to the low-symmetry T-like phase BiFeO3, because the spontaneous polarization vector of T-like phase (with monoclinic symmetry) BiFeO3 can rotate easily under external field. In addition, the reduced leakage current and major domains with upward polarization are also attributed to the large piezoelectricity.

  8. CNDOL: A fast and reliable method for the calculation of electronic properties of very large systems. Applications to retinal binding pocket in rhodopsin and gas phase porphine

    NASA Astrophysics Data System (ADS)

    Montero-Cabrera, Luis Alberto; Röhrig, Ute; Padrón-Garcia, Juan A.; Crespo-Otero, Rachel; Montero-Alejo, Ana L.; Garcia de la Vega, José M.; Chergui, Majed; Rothlisberger, Ursula

    2007-10-01

    Very large molecular systems can be calculated with the so called CNDOL approximate Hamiltonians that have been developed by avoiding oversimplifications and only using a priori parameters and formulas from the simpler NDO methods. A new diagonal monoelectronic term named CNDOL/21 shows great consistency and easier SCF convergence when used together with an appropriate function for charge repulsion energies that is derived from traditional formulas. It is possible to obtain a priori molecular orbitals and electron excitation properties after the configuration interaction of single excited determinants with reliability, maintaining interpretative possibilities even being a simplified Hamiltonian. Tests with some unequivocal gas phase maxima of simple molecules (benzene, furfural, acetaldehyde, hexyl alcohol, methyl amine, 2,5 dimethyl 2,4 hexadiene, and ethyl sulfide) ratify the general quality of this approach in comparison with other methods. The calculation of large systems as porphine in gas phase and a model of the complete retinal binding pocket in rhodopsin with 622 basis functions on 280 atoms at the quantum mechanical level show reliability leading to a resulting first allowed transition in 483nm, very similar to the known experimental value of 500nm of "dark state." In this very important case, our model gives a central role in this excitation to a charge transfer from the neighboring Glu- counterion to the retinaldehyde polyene chain. Tests with gas phase maxima of some important molecules corroborate the reliability of CNDOL/2 Hamiltonians.

  9. CNDOL: A fast and reliable method for the calculation of electronic properties of very large systems. Applications to retinal binding pocket in rhodopsin and gas phase porphine.

    PubMed

    Montero-Cabrera, Luis Alberto; Röhrig, Ute; Padrón-Garcia, Juan A; Crespo-Otero, Rachel; Montero-Alejo, Ana L; Garcia de la Vega, José M; Chergui, Majed; Rothlisberger, Ursula

    2007-10-14

    Very large molecular systems can be calculated with the so called CNDOL approximate Hamiltonians that have been developed by avoiding oversimplifications and only using a priori parameters and formulas from the simpler NDO methods. A new diagonal monoelectronic term named CNDOL/21 shows great consistency and easier SCF convergence when used together with an appropriate function for charge repulsion energies that is derived from traditional formulas. It is possible to obtain a priori molecular orbitals and electron excitation properties after the configuration interaction of single excited determinants with reliability, maintaining interpretative possibilities even being a simplified Hamiltonian. Tests with some unequivocal gas phase maxima of simple molecules (benzene, furfural, acetaldehyde, hexyl alcohol, methyl amine, 2,5 dimethyl 2,4 hexadiene, and ethyl sulfide) ratify the general quality of this approach in comparison with other methods. The calculation of large systems as porphine in gas phase and a model of the complete retinal binding pocket in rhodopsin with 622 basis functions on 280 atoms at the quantum mechanical level show reliability leading to a resulting first allowed transition in 483 nm, very similar to the known experimental value of 500 nm of "dark state." In this very important case, our model gives a central role in this excitation to a charge transfer from the neighboring Glu(-) counterion to the retinaldehyde polyene chain. Tests with gas phase maxima of some important molecules corroborate the reliability of CNDOL/2 Hamiltonians.

  10. Large-scale gas dynamics in the adhesion model: implications for the two-phase massive galaxy formation scenario

    NASA Astrophysics Data System (ADS)

    Domínguez-Tenreiro, R.; Oñorbe, J.; Martínez-Serrano, F.; Serna, A.

    2011-06-01

    We have studied the mass assembly and star formation histories of massive galaxies identified at low redshift in different cosmological hydrodynamical simulations. To this end, we have carried out a detailed follow-up backwards in time of their constituent mass elements (sampled by particles) of different types. After that, the configurations they depict at progressively higher zs were carefully analysed. The analyses show that these histories share common generic patterns, irrespective of particular circumstances. In any case, however, the results we have found are different depending on the particle type. The most outstanding differences follow. We have found that by z˜ 3.5-6, mass elements identified as stellar particles at z= 0 exhibit a gaseous cosmic-web-like morphology with scales of ˜1 physical Mpc, where the densest mass elements have already turned into stars by z˜ 6. These settings are in fact the densest pieces of the cosmic web, where no hot particles show up, and dynamically organized as a hierarchy of flow convergence regions (FCRs), that is, attraction basins for mass flows. At high z FCRs undergo fast contractive deformations with very low angular momentum, shrinking them violently. Indeed, by z˜ 1 most of the gaseous or stellar mass they contain shows up as bound to a massive elliptical-like object at their centres, with typical half-mass radii of rmassstar˜ 2-3 kpc. After this, a second phase comes about where the mass assembly rate is much slower and characterized by mergers involving angular momentum. On the other hand, mass elements identified at the diffuse hot coronae surrounding massive galaxies at z= 0 do not display a clear web-like morphology at any z. Diffuse gas is heated when FCRs go through contractive deformations. Most of this gas remains hot and with low density throughout the evolution. To shed light on the physical foundations of the behaviour revealed by our analyses (i.e. a two-phase formation process with different

  11. One-step large scale gas phase synthesis of Mn(2 + ) doped ZnS nanoparticles in reducing flames.

    PubMed

    Athanassiou, E K; Grass, R N; Stark, W J

    2010-05-28

    Metal sulfide nanoparticles have attracted considerable interest because of their unique semiconducting and electronic properties. In order to prepare these fascinating materials at an industrial scale, however, solvent-free, dry processes would be most advantageous. In the present work, we demonstrate how traditional oxide nanoparticle synthesis in flames can be extended to sulfides if we apply a careful control on flame gas composition and sulfur content. The ultra-fast (<1 ms) gas phase kinetics at elevated temperatures allow direct sulfidization of metals in flames ([Formula: see text]). As a representative example, we prepared air-stable Mn(2 + ) doped zinc sulfide nanoparticles. Post-sintering of the initially polycrystalline nanopowder resulted in a material of high crystallinity and improved photoluminescence. An analysis of the thermodynamics, gas composition, and kinetics in these reducing flames indicates that the here-presented extension of flame synthesis provides access to a broad range of metal sulfide nanoparticles and offers an alternative to non-oxide phosphor preparation. PMID:20431199

  12. One-step large scale gas phase synthesis of Mn2 + doped ZnS nanoparticles in reducing flames

    NASA Astrophysics Data System (ADS)

    Athanassiou, E. K.; Grass, R. N.; Stark, W. J.

    2010-05-01

    Metal sulfide nanoparticles have attracted considerable interest because of their unique semiconducting and electronic properties. In order to prepare these fascinating materials at an industrial scale, however, solvent-free, dry processes would be most advantageous. In the present work, we demonstrate how traditional oxide nanoparticle synthesis in flames can be extended to sulfides if we apply a careful control on flame gas composition and sulfur content. The ultra-fast (<1 ms) gas phase kinetics at elevated temperatures allow direct sulfidization of metals in flames (\\mathrm {MO}_{x} \\Rightarrow \\mathrm {MS}_{x} ). As a representative example, we prepared air-stable Mn2 + doped zinc sulfide nanoparticles. Post-sintering of the initially polycrystalline nanopowder resulted in a material of high crystallinity and improved photoluminescence. An analysis of the thermodynamics, gas composition, and kinetics in these reducing flames indicates that the here-presented extension of flame synthesis provides access to a broad range of metal sulfide nanoparticles and offers an alternative to non-oxide phosphor preparation.

  13. 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.

  14. Large fraction radiotherapy plus misonidazole for treatment of advanced lung cancer: report of a phase I/II trial

    SciTech Connect

    Simpson, J.R.; Perez, C.A.; Phillips, T.L.; Concannon, J.P.; Carella, R.J.

    1982-02-01

    From August 1978 through December 1979, 51 patients with advanced non-oat cell carcinoma of the lung were enrolled in a Phase I/II trial sponsored by the Radiation Therapy Oncology Group (RTOG) employing misonidazole (a 2-nitroimidazole) as a hypoxic cell sensitizer and radiation. The purpose of this study was to test drug and radiation tolerance and to assess the short term efficacy of this unconventional treatment. Tumor doses of 600 rad were given twice weekly for three weeks for a total of 3600 rad, preceded four to six hours by misonidazole in a dose of 2 gm/m/sup 2/ or 1.75 gm/m/sup 2/, administered orally. Forty-nine patients were evaluable. Serious toxicity from this treatment was rare. Grade 2 or 3 peripheral neuro-toxicity occurred in eight of 24 patients (33%) with drug doses of 2 gm/m/sup 2/ and in four of 26 patients (15%) who received 1.75 gm/m/sup 2/. Grade 3 or 4 central nervous system toxicity occurred in two patients. Two patients developed serious late radiation complications: one patient had a transverse myelitis that appeared one year following delivery of 3600 rad to the spinal cord; a second patient developed a tracheoesophageal fistula and pericarditis eight months following treatment. Objective responses were reported in 67% of patients (complete in 18%); 70% of the patients died with a median survival time of nine months. Of 32 patients eligible for 12 month follow-up, 34% survived more than one year. Patterns of relapse after initial treatment and comparison with results from other RTOG trials using conventional fractionation are discussed.

  15. Evidence for phase-explosion and generation of large particles during high power nanosecond laser ablation of silicon

    SciTech Connect

    Yoo, J. H.; Jeong, S. H.; Mao, X. L.; Greif, R.; Russo, R. E.

    2000-02-07

    The craters resulting from high-irradiance (1x10{sup 9}-1x10{sup 11} W/cm{sup 2}) single-pulse laser ablation of single-crystal silicon show a dramatic increase in volume at a threshold irradiance of 2.2x10{sup 10} W/CM{sup 2}. Time-resolved shadowgraph images show ejection of large particulates from the sample above this threshold irradiance, with a time delay {approx}300 ns. A numerical model was used to estimate the thickness of a superheated layer near the critical state. Considering the transformation of liquid metal into liquid dielectric near the critical state (i.e., induced transparency), the calculated thickness of the superheated layer at a delay time of 200-300 ns agreed with the measured crater depths. This agreement suggests that induced transparency promotes the formation of a deep superheated layer, and explosive boiling within this layer leads to particulate ejection from the sample. (c) 2000 American Institute of Physics.

  16. 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.

  17. A phase field approach with a reaction pathways-based potential to model reconstructive martensitic transformations with a large number of variants

    NASA Astrophysics Data System (ADS)

    Denoual, C.; Vattré, A.

    2016-05-01

    A pathway tree is constructed by recursively duplicating a single reconstructive martensitic transformation path with respect to lattice symmetries and point-group rotations. An energy potential built on this pathway is implemented in a phase-field technique in large strain framework, with the transformational strain as the order parameter. A specific splitting between non-dissipative elastic behavior and the dissipative evolution of the order parameter allows for the modeling of acoustic waves during rapid transformations. A simple toy-model transition from hexa- to square-lattice successfully demonstrates the possibility to model reconstructive martensitic transformations for a large number of variants (more than one hundred). Pure traction applied to our toy-model shows that variants can nucleate into previously created variants, with a hierarchical nucleation of variants spanning over five levels of transformation.

  18. Simple and effective large-scale preparation of geniposide from fruit of Gardenia jasminoides Ellis using a liquid-liquid two-phase extraction.

    PubMed

    Zhou, Min; Zhuo, Jiaxiong; Wei, Wanxing; Zhu, Jianwen; Ling, Xiurong

    2012-12-01

    Geniposide was prepared on a large-scale using a selective two-phase liquid-liquid extraction. The aqueous residue from the fruit of Gardenia jasminoides Ellis was treated with sodium carbonate and extracted with n-butanol several times. The n-butanol extracts were treated with activated granular charcoal to remove pigments and were then concentrated to produce a residue with a high solid content. The residue was crystallized to obtain geniposide with 98% purity. For large-scale synthesis, the residue (solid content 45%, geniposide 5.5%) was extracted to generate 70g of geniposide with 98% purity and 84.8% recovery using 1500g residue. PMID:22975161

  19. 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

  20. 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

  1. Complete larval development of the Monkey River Prawn Macrobrachium lar (Palaemonidae) using a novel greenwater technique.

    PubMed

    Lal, Monal M; Seeto, Johnson; Pickering, Timothy D

    2014-01-01

    This study documents the complete larval development of the Monkey River Prawn Macrobrachium lar using a new greenwater rearing technique. Approximately 6,000 larvae were reared for 110 days at an initial stocking density of 1 ind./6 L. Salinity at hatch was 10 ± 2 ppt and progressively increased to 30 ± 2 ppt until decapodids had metamorphosed. Temperature was maintained at 28 ± 0.5°C, pH at 7.8 ± 0.2, DO2 > 6.5 mg/L and NH(4+) and NH3 ≤ 1.5 and ≤0.1 ppm respectively throughout the culture period. Larval development was extended and occurred through 13 zoeal stages, with the first decapodid measuring 6.2 ± 0.63 mm in total length observed after 77 days. 5 decapodids in total were produced, and overall survival to this stage was 0.08%. Overall, the pattern of larval growth shares similarities with those of other Macrobrachium spp. that have a prolonged/normal type of development, and it is likely that larvae underwent mark time moulting which contributed to the lengthened development duration. While this study represents a significant breakthrough in efforts to domesticate M. lar, improvement of larval survival rates and decreased time till metamorphosis are required before it can become fully viable for commercial scale aquaculture.

  2. Complete larval development of the Monkey River Prawn Macrobrachium lar (Palaemonidae) using a novel greenwater technique.

    PubMed

    Lal, Monal M; Seeto, Johnson; Pickering, Timothy D

    2014-01-01

    This study documents the complete larval development of the Monkey River Prawn Macrobrachium lar using a new greenwater rearing technique. Approximately 6,000 larvae were reared for 110 days at an initial stocking density of 1 ind./6 L. Salinity at hatch was 10 ± 2 ppt and progressively increased to 30 ± 2 ppt until decapodids had metamorphosed. Temperature was maintained at 28 ± 0.5°C, pH at 7.8 ± 0.2, DO2 > 6.5 mg/L and NH(4+) and NH3 ≤ 1.5 and ≤0.1 ppm respectively throughout the culture period. Larval development was extended and occurred through 13 zoeal stages, with the first decapodid measuring 6.2 ± 0.63 mm in total length observed after 77 days. 5 decapodids in total were produced, and overall survival to this stage was 0.08%. Overall, the pattern of larval growth shares similarities with those of other Macrobrachium spp. that have a prolonged/normal type of development, and it is likely that larvae underwent mark time moulting which contributed to the lengthened development duration. While this study represents a significant breakthrough in efforts to domesticate M. lar, improvement of larval survival rates and decreased time till metamorphosis are required before it can become fully viable for commercial scale aquaculture. PMID:25332868

  3. 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

  4. Thalidomide enhanced the efficacy of CHOP chemotherapy in the treatment of diffuse large B cell lymphoma: A phase II study.

    PubMed

    Ji, Dongmei; Li, Qiu; Cao, Junning; Guo, Ye; Lv, Fangfang; Liu, Xiaojian; Wang, Biyun; Wang, Leiping; Luo, Zhiguo; Chang, Jianhua; Wu, Xianghua; Hong, Xiaonan

    2016-05-31

    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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Investigating the Microphysics of Arctic Mixed-Phase Clouds using Large Eddy Simulations: The Importance of Liquid-Dependent Ice Nucleation

    NASA Astrophysics Data System (ADS)

    Young, Gillian; Connolly, Paul J.; Jones, Hazel M.; Choularton, Thomas W.; Gallagher, Martin W.; Crosier, Jonathan; Lloyd, Gary; Bower, Keith N.

    2015-04-01

    Our ability to comprehend and accurately model the Arctic climate is currently hindered by a lack of observations of the atmospheric processes unique to this region. A significant source of uncertainty in such models may be found in our representation of aerosol-cloud interactions [1]: for example, there are unanswered questions concerning the relationship between the ice-nucleating Arctic aerosol and the unique cloud microphysics observed in this region [2]. In an effort to address this issue, the Aerosol-Cloud Coupling and Climate Interactions in the Arctic (ACCACIA) campaign of 2013 was conducted in the vicinity of the Svalbard archipelago, carrying out in-situ airborne observations of the mixed-phase clouds in this region. This campaign was split into two segments - one in spring, the other in summer - with airborne- and surface-based measurement platforms utilised in each. During the spring campaign, a range of microphysics and remote-sensing instruments were active on board the Facility for Airborne Atmospheric Measurements' (FAAM) BAe146 aircraft to produce a detailed record of the observed Arctic atmosphere. These data were used to conduct a modelling investigation with a focus on ice nucleation: the Large Eddy Model (LEM) - a cloud-resolving model developed by the UK Met Office - was initialised from these observations and simulations were performed to allow the resultant cloud evolution, structure and microphysics to be examined. Models on various scales notoriously have issues with reproducing persistent, mixed-phase Arctic clouds [2,3] and, upon first inspection, the LEM was no different: the modelled cloud dissipated quickly, thus inaccurately replicating the long-lived, mixed-phase clouds observed. However, by considering the discrepancies between the model output and aircraft observations, the treatment of cloud microphysics within the LEM has been developed to improve the simulation of the observed clouds. A long-lived, mixed-phase cloud of similar

  10. 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

  11. Sunitinib in relapsed or refractory diffuse large B-cell lymphoma: a clinical and pharmacodynamic phase II multicenter study of the NCIC Clinical Trials Group

    PubMed Central

    Buckstein, Rena; Kuruvilla, John; Chua, Neil; Lee, Christina; Macdonald, David A; Al-Tourah, Abdulwahab J; Foo, Alison H; Walsh, Wendy; Ivy, S Percy; Crump, Michael; Eisenhauer, Elizabeth A

    2011-01-01

    There are limited effective therapies for most patients with relapsed diffuse large B-cell lymphoma (DLBCL). We conducted a phase II trial of the multi-targeted vascular endothelial growth factor receptor (VEGFR) kinase inhibitor, sunitinib, 37.5 mg given orally once daily in adult patients with relapsed or refractory DLBCL. Of 19 enrolled patients, 17 eligible patients were evaluable for toxicity and 15 for response. No objective responses were seen and nine patients achieved stable disease (median duration 3.4 months). As a result, the study was closed at the end of the first stage. Grades 3—4 neutropenia and thrombocytopenia were observed in 29% and 35%, respectively. There was no relationship between change in circulating endothelial cell numbers (CECs) and bidimensional tumor burden over time. Despite some activity in solid tumors, sunitinib showed no evidence of response in relapsed/refractory DLBCL and had greater than expected hematologic toxicity. PMID:21463120

  12. Large radius of curvature measurement based on virtual quadratic Newton rings phase-shifting moiré-fringes measurement method in a nonnull interferometer.

    PubMed

    Yang, Zhongming; Wang, Kailiang; Cheng, Jinlong; Gao, Zhishan; Yuan, Qun

    2016-06-10

    We have proposed a virtual quadratic Newton rings phase-shifting moiré-fringes measurement method in a nonnull interferometer to measure the large radius of curvature for a spherical surface. In a quadratic polar coordinate system, linear carrier testing Newton rings interferogram and virtual Newton rings interferogram form the moiré fringes. It is possible to retrieve the wavefront difference data between the testing and standard spherical surface from the moiré fringes after low-pass filtering. Based on the wavefront difference data, we deduced a precise formula to calculate the radius of curvature in the quadratic polar coordinate system. We calculated the retrace error in the nonnull interferometer using the multi-configuration model of the nonnull interferometric system in ZEMAX. Our experimental results indicate that the measurement accuracy is better than 0.18% for a spherical mirror with a radius of curvature of 41,400 mm.

  13. Experimental and numerical investigation of ADP square crystal with large aperture in the new Final Optics Assembly under the non-critical phase matching

    NASA Astrophysics Data System (ADS)

    Sun, Fuzhong; Zhang, Peng; Bai, Qingshun; Lu, Lihua; Xiang, Yong

    2016-04-01

    This paper presented a new Final Optics Assembly (FOA) of ammonium dihydrogen phosphate (ADP) square crystal with large aperture under the non-critical phase matching (NCPM), which controlled by the constant temperature water, and the temperature distribution was analyzed by simulation and experiment. Firstly, thermal analysis was carried out, as well as the temperature distribution of the cavity only heated under different velocities was analyzed. Then, the temperature distributions of ADP square crystal in the cavity were achieved using the Finite Volume Method (FVM), and this prediction was validated by the experiment results when the velocity is 0.1 m/s and 0.5 m/s. Finally, the optimal FHG conversion efficiency was obtained and the comparison of different heating methods was also highlighted.

  14. SALM4 suppresses excitatory synapse development by cis-inhibiting trans-synaptic SALM3-LAR adhesion.

    PubMed

    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.

  15. SALM4 suppresses excitatory synapse development by cis-inhibiting trans-synaptic SALM3-LAR adhesion.

    PubMed

    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

  16. Redecoration of apartments promotes obstructive bronchitis in atopy risk infants--results of the LARS Study.

    PubMed

    Diez, Ulrike; Rehwagen, Martina; Rolle-Kampczyk, Ulrike; Wetzig, Heide; Schulz, Rita; Richter, Matthias; Lehmann, Irina; Borte, Michael; Herbarth, Olf

    2003-06-01

    Findings by other authors indicate that exposure to chemical emissions from indoor paint is related to asthma symptoms in adults. In their first years of life children are receptive to obstructive airway diseases. The aim of this study was to investigate the influence of redecoration of the apartment on airway symptoms in infants during the first two years of life. The Leipzig Allergy Risk Children Study (LARS) is a birth cohort study with the following inclusion criteria: double positive family atopy anamnesis, cord blood IgE > 0.9 kU/l, or low birth weight between 1500-2500 g. Within the context of LARS, 186 parents of risk children completed a questionnaire on the respiratory symptoms of their children and the redecoration of their apartment at the end of the first and second year of life. A total 22% of the children suffered from obstructive bronchitis once or more during their first year, and 11% experienced this condition during their second year of life. Redecoration of the apartment had a significant influence on the appearance of obstructive bronchitis in the first (OR 4.1 95% CI 1.4-11.9) and in the second year of life (OR 4.2 95% CI 1.4-12.9). (The OR are adjusted for cord blood-IgE > 0.9 kU/l, birth weight < or = 2500 g, male sex and double positive parental atopy anamnesis, dampness, smoking or pet in the apartment). Simultaneous contamination from redecoration activities and additional exposures such as smoking, a pet or dampness in the apartment increased the risk for obstructive bronchitis in the first year (OR 9.1; 95% CI 2.3-34.8) as well as in the second year (OR 5.1; 95% CI 1.6-15.6). Our data suggest that redecoration of the apartment is associated with the development of acute inflammations, but not with a chronic influence on the airways in atopy risk infants. At an exposure to more than one environmental factor, pronounced effects were seen.

  17. 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

  18. 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.

  19. 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

    2012-07-01

    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.

  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.; 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.,more » scanning tunneling microscopy (STM), angle-resolved photoemission spectroscopy (ARPES), and point-contact spectroscopy (PCS)] but cannot be used under pressure.« less

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Lab to Large Scale Transition for Non-Vacuum Thin Film CIGS Solar Cells: Phase II--Annual Technical Report, August 2003-July 2004

    SciTech Connect

    Kapur, V. K.; Bansal, A.; Asenio, O. I.; Shigeoka, M. K.; Le, P.; Gergen, B.; Rasmussen, M.; Zuniga, R.

    2005-01-01

    The purpose of this subcontract, as part of the R&D Partners category is to: (i) identify the challenges that International Solar Electric Technology, Inc. (ISET) may face in the process of making a ''Lab to Large Scale'' transition for its ink-based non-vacuum process in production of thin-film CIGS solar cells and modules, and (ii) develop workable solutions for these challenges such that they can readily be implemented in a large-scale processing line for CIGS modules. The primary objective of this research is to streamline ISET's ink-based non-vacuum process for fabricating efficient CIGS modules to lower the cost of module production << $1.0/watt. To achieve this objective, ISET has focused R&D efforts on investigating topics that directly impact the ultimate cost of processing CIGS modules. These topics of concern include (i) module output, and therefore, the solar cell and the module efficiency, (ii) overall process yield which requires developing a process that offers a very high degree of repeatability for every manufacturing step, and (iii) a process approach that maximizes the utilization of the materials used. In accordance with the above, this report will cover activity during Phase II in the investigation of methods for low-cost manufacturing and process development. Specific tasks cover four broad areas: (1) solar cell efficiency, (2) process control, (3) module integration, and (4) enhanced material utilization by reduction of waste stream.

  6. Dynamic and static control of the optical phase of guided p-polarized light for near-field focusing at large angles of incidence

    NASA Astrophysics Data System (ADS)

    Huang, Danhong; Michelle Easter, M.; David Wellems, L.; Mozer, Henry; Gumbs, Godfrey; Cardimona, D. A.; Maradudin, A. A.

    2013-07-01

    Both dynamic and static approaches are proposed and investigated for controlling the optical phase of a p-polarized light wave guided through a surface-patterned metallic structure with subwavelength features. For dynamic control, the important role of photo-excited electrons in a slit-embedded atomic system with field-induced transparency (FIT) is discovered within a narrow frequency window for modulating the intensity of focused transmitted light in the near-field region. This is facilitated by electromagnetic coupling to surface plasmons between the two FIT-atom embedded slits. The near-field distribution can be adjusted by employing a symmetric (or asymmetric) slit configuration and by a small (or large) slit separation. In addition, the cross-transmission of a light beam is also predicted as a result of this strong coupling between optical transitions in embedded FIT atoms and surface plasmons. For static control, the role of surface curvature is found for focused transmitted light passing through a Gaussian-shaped metallic microlens embedded with a linear array of slits. A negative light-refraction pattern, which is associated with higher-order diffraction modes, was also found for large angles of incidence in the near-field region. This anomalous negative refraction can be suppressed when higher-order waveguide modes of light leak through a very thin film. In addition, this negative refraction can also be suppressed with a reinforced reflection at the left foothill of a Gaussian-shaped slit array of the forward-propagating surface-plasmon wave at large angles of incidence. A prediction is given of near-field focusing of light with its sharpness dynamically controlled by the frequency of the light in a very narrow window. Moreover, a different scheme based on Green's second integral identity is proposed for overcoming a difficulty in calculating the near-field distribution very close to a metallic surface by means of a finite-difference-time-domain method.

  7. 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

  8. 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; 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 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

  9. 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.

  10. 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.

  11. Molten salt synthesis (MSS) of Cu{sub 2}Mo{sub 6}S{sub 8}-New way for large-scale production of Chevrel phases

    SciTech Connect

    Lancry, E. . E-mail: eli.lancry@intel.com; Levi, E.; Mitelman, A.; Malovany, S.; Aurbach, D.

    2006-06-15

    The Chevrel phase (CP), Mo{sub 6}S{sub 8}, was found to be an excellent cathode material for rechargeable magnesium batteries. Mo{sub 6}S{sub 8} is obtained by a leaching process of Cu{sub 2}Mo{sub 6}S{sub 8}, which removes the copper. A new method of Cu{sub 2}Mo{sub 6}S{sub 8} production was developed. In contrast to the well-known solid-state synthesis of CP, the method is based on the reaction in a molten salt media (KCl). A fast kinetics of this reaction allows using less active, but more convenient precursors (sulfides instead of sulfur), decreasing temperature and synthesis duration, as well as operation in the inert atmosphere instead of dynamic evacuated systems. It was shown that the composition and the electrochemical behavior of the products obtained by MSS and by the solid-state synthesis are identical. Thus, the molten salt method is extremely attractive for the large-scale production of the active materials for Mg batteries. - Graphical abstract: The layout of the molten salt synthesis system.

  12. 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

  13. Preparation phase and consequences of a large earthquake: insights from foreshocks and aftershocks of the 2014 Mw 8.1 Iquique earthquake, Chile

    NASA Astrophysics Data System (ADS)

    Cesca, Simone; Grigoli, Francesco; Heimann, Sebastian; Dahm, Torsten

    2015-04-01

    The April 1, 2014, Mw 8.1 Iquique earthquake in Northern Chile, was preceded by an anomalous, extensive preparation phase. The precursor seismicity at the ruptured slab segment was observed sporadically several months before the main shock, with a significant increment in seismicity rates and observed magnitudes in the last three weeks before the main shock. The large dataset of regional recordings helped us to investigate the role of such precursor activity, comparing foreshock and aftershock seismicity to test models of rupture preparation and models of strain and stress rotation during an earthquake. We used full waveforms techniques to locate events, map the seismicity rate, derive source parameters, and assess spatiotemporal stress changes. Results indicate that the spatial distributions of foreshocks delineated the shallower part of the rupture areas of the main shock and its largest aftershock, and is well matching the spatial extension of the aftershocks. During the foreshock sequence, seismicity spatially is mainly localized in two clusters, separated by a region of high locking. The ruptures of mainshock and largest aftershock nucleate within these clusters and propagate to the locked region; the aftershocks are again localized in correspondence to the original spatial clusters, and the central region is locked again. More than 300 moment tensor inversions were performed, down to Mw 4.0, most of them corresponding to almost pure double couple thrust mechanisms, with a geometry consistent with the slab orientation. No significant differences are observed among thrust mechanisms in different areas, nor among thrust foreshocks and aftershocks. However, a new family of normal fault mechanisms appears after the main shock, likely affecting the shallow wedge structure in consequence of the increased extensional stress in this region. We infer a stress rotation after the main shock, as proposed for recent larger thrust earthquakes, which suggests that the April

  14. A phase II, single-arm, multicentre study of coltuximab ravtansine (SAR3419) and rituximab in patients with relapsed or refractory diffuse large B-cell lymphoma.

    PubMed

    Coiffier, Bertrand; Thieblemont, Catherine; de Guibert, Sophie; Dupuis, Jehan; Ribrag, Vincent; Bouabdallah, Réda; Morschhauser, Franck; Navarro, Robert; Le Gouill, Steven; Haioun, Corinne; Houot, Roch; Casasnovas, Olivier; Holte, Harald; Lamy, Thierry; Broussais, Florence; Payrard, Sandrine; Hatteville, Laurence; Tilly, Hervé

    2016-06-01

    In this phase II, multicentre, single-arm study, 52 patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) received the anti-CD19 antibody-drug conjugate coltuximab ravtansine (55 mg/m(2) ) and rituximab (375 mg/m(2) ) weekly for 4 weeks, then every 2 weeks for 8 weeks. The primary endpoint was objective response rate (ORR) by International Working Group Criteria. The primary objective was to reject the null hypothesis of an ORR of ≤40%. Among 45 evaluable patients, the ORR was 31·1% (80% confidence interval [CI]: 22·0-41·6%) and the primary objective was not met. The ORR appeared higher in patients with relapsed disease (58·3% [80% CI: 36·2-78·1%]) versus those refractory to their last (42·9% [80% CI: 17·0-72·1%]) or first-line therapy (15·4% [80% CI: 6·9-28·4%]). Median progression-free survival, overall survival and duration of response were 3·9 [80% CI: 3·22-3·98], 9·0 [80% CI: 6·47-13·67] and 8·6 (range: 0-18) months, respectively. The pharmacokinetics of both drugs were unaffected by co-administration. Common adverse events included gastrointestinal disorders (52%) and asthenia (25%). No patients discontinued due to adverse events. In conclusion, coltuximab ravtansine with rituximab was well tolerated and yielded clinical responses in a subset of patients with relapsed/refractory DLBCL. PMID:27010483

  15. Phase 2 study of the bispecific T-cell engager (BiTE) antibody blinatumomab in relapsed/refractory diffuse large B-cell lymphoma.

    PubMed

    Viardot, Andreas; 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

    2016-03-17

    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

  16. 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.

  17. 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

  18. 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.

  19. Thermal-Driven Fluorite-Pyrochlore-Fluorite Phase Transitions of Gd2Zr2O7 Ceramics Probed in Large Range of Sintering Temperature

    NASA Astrophysics Data System (ADS)

    Zhou, Li; Huang, Zhangyi; Qi, Jianqi; Feng, Zhao; Wu, Dengxue; Zhang, Wei; Yu, Xiaohe; Guan, Yongbing; Chen, Xingtao; Xie, Landong; Sun, Kai; Lu, Tiecheng

    2016-01-01

    Fluorite (F)-pyrochlore (P)-fluorite (F) phase transitions of Gd2Zr2O7 were investigated from 573 K to 1873 K (300 °C to 1600 °C), by means of X-ray diffraction, infrared spectra (IR), and Raman spectra. The low-temperature F phase can stably exist below 1523 K (1250 °C) and the F-P transition occurs at 1523 K to 1573 K (1250 °C to 1300 °C). The ordering process of P phase forms at 1573 K to 1773 K (1300 °C to 1500 °C) and the ordering degree increases with increasing sintering temperature and heat preservation period. High-temperature phase transition from P to F occurs between 1773 K and 1823 K (1300 °C and 1550 °C). IR spectra of samples with different ordering degrees show an interesting shift at 510 cm-1. Raman spectra show that only the A1 g mode displays a significant change between F and P phases. This ordering degree and phase transition temperature studies would allow a more targeted experimental optimization of Gd2Zr2O7 to use in nuclear waste host, thermal barrier coatings, and solid oxide fuel cells.

  20. What’s the Big Deal? Responder Experiences of Large Animal Rescue in Australia

    PubMed Central

    Smith, Bradley; Thompson, Kirrilly; Taylor, Melanie

    2015-01-01

    Background: The management of large animals during disasters and emergencies creates difficult operational environments for responders. The aims of this study were to identify the exact challenges faced by Australian emergency response personnel in their interactions with large animals and their owners, and to determine the readiness for large animal rescue (LAR) in Australia. Methods: A survey tool collected the views and experiences of a broad cross section of emergency services personnel operating across Australia and across all hazards. Data were collected from 156 responders including Australian emergency services personnel, emergency managers such as federal agricultural departments, and local government. Results: Overall, many of the respondents had serious concerns, and felt that there were significant issues in relation to LAR in Australia. These included the coordination of emergency care for animals, physical management of large animals, inter-agency coordination, and dealing with animal owners. Very few respondents had received any formal training in LAR, with an overwhelming majority indicating they would attend formal training if it were made available. Discussion: Results help to guide the development of evidence-informed support tools to assist operational response and community engagement, and the production of professional development resources. PMID:25685637

  1. 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.

  2. Treatment with octreotide LAR in clinically non-functioning pituitary adenoma: results from a case-control study.

    PubMed

    Fusco, Alessandra; Giampietro, Antonella; Bianchi, Antonio; Cimino, Vincenzo; Lugli, Francesca; Piacentini, Serena; Lorusso, Margherita; Tofani, Anna; Perotti, Germano; Lauriola, Libero; Anile, Carmelo; Maira, Giulio; Pontecorvi, Alfredo; De Marinis, Laura

    2012-12-01

    Surgical cure cannot be achieved in most patients with invasive non-functioning pituitary macroadenoma (NFPA). Short-term residual tumor treatment with somatostatin analogs has produced disappointing results. This prospective case-control study assessed the efficacy of chronic treatment with long acting octreotide (octreotide LAR) on tumor volume in patients harboring post-surgical NFPA residue. The study population comprised 39 patients with NFPAs not cured by surgery. All patients underwent somatostatin receptor scintigraphy at least 6 months after the last surgery. Patients with a positive pituitary level octreoscan at (n = 26) received octreotide LAR (20 mg every 28 days) for ≥ 12 months (mean follow-up 37 ± 18 months) (Treated group). Moreover, a fragment of tumor tissue from patients in the treated group was retrospectively collected to assess the immunohistochemical expression of somatostatin receptor subtypes (SSTRs). The patients with a negative octreoscan (n = 13) formed the control group (mean follow-up 37 ± 16 months). Hormonal, radiological and visual field parameters were periodically assessed. In the treated group, all tumors expressed at least one SSTR subtype. The SSTR5 subtype was the most abundant, followed by SSTR3. The tumor residue increased in five of 26 patients (19%) in the treated group and in seven of 13 controls (53%). Visual field and pituitary function did not change in any patient. This study indicates that SSTR5 and SSTR3 are the most frequently expressed SSTR subtypes in NFPAs and supports a potential role of SSTR subtypes in stabilization of tumor remnant from NFPAs. PMID:22207350

  3. Prediction of temperature and precipitation in Sudan and South Sudan by using LARS-WG in future

    NASA Astrophysics Data System (ADS)

    Chen, Hua; Guo, Jiali; Zhang, Zengxin; Xu, Chong-Yu

    2013-08-01

    Global warming has brought great pressure on the environment and livelihood conditions in Sudan and South Sudan. It is desirable to analyze and predict the change of critical climatic variables, such as temperature and precipitation, which will provide valuable reference results for future water resources planning and management in the region. The aims of this study are to test the applicability of the Long Ashton Research Station Weather Generator (LARS-WG) model in downscaling daily precipitation and daily maximum (Tmax) and daily minimum (Tmin) temperatures in Sudan and South Sudan and use it to predict future changes of precipitation; Tmin and Tmax for nine stations in Sudan and South Sudan are based on the SRA2 scenario of seven General Circulation Models (GCMs) outputs for the periods of 2011-2030, 2046-2065, and 2080-2099. The results showed that (1) the LARS-WG model produces good performance in downscaling daily precipitation and excellent performance in downscaling Tmax and Tmin in the study region; (2) downscaled precipitation from the prediction of seven GCMs showed great inconsistency in these two regions, which illustrates the great uncertainty in GCMs' results in the regions; (3) predicted precipitation in rainy season JJA (June, July, and August) based on the ensemble mean of seven GCMs showed a decreasing trend in the periods of 2011-2030, 2046-2065, and 2080-2099 in Sudan; however, an increasing trend can be found in SON (September, October, and November) in the future; (4) precipitation in South Sudan has an increasing trend in most seasons in the future except in MAM (March, April, and May) season in 2011-2030; and (5) predictions from seven GCMs showed a similar and continuous increasing trend for Tmax and Tmin in all three future periods, which will bring severe negative influence on improving livelihoods and reducing poverty in Sudan and South Sudan.

  4. 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. PMID:25996244

  5. 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.

  6. 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.

  7. Influence of nonhomogeneous earth on the rms phase error and beam-pointing errors of large, sparse high-frequency receiving arrays

    NASA Astrophysics Data System (ADS)

    Weiner, M. M.

    1994-01-01

    The performance of ground-based high-frequency (HF) receiving arrays is reduced when the array elements have electrically small ground planes. The array rms phase error and beam-pointing errors, caused by multipath rays reflected from a nonhomogeneous Earth, are determined for a sparse array of elements that are modeled as Hertzian dipoles in close proximity to Earth with no ground planes. Numerical results are presented for cases of randomly distributed and systematically distributed Earth nonhomogeneities where one-half of vertically polarized array elements are located in proximity to one type of Earth and the remaining half are located in proximity to a second type of Earth. The maximum rms phase errors, for the cases examined, are 18 deg and 9 deg for randomly distributed and systematically distributed nonhomogeneities, respectively. The maximum beampointing errors are 0 and 0.3 beam widths for randomly distributed and systematically distributed nonhomogeneities, respectively.

  8. 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).

  9. 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.

  10. Overview of the front end electronics for the Atlas LAR calorimeter

    SciTech Connect

    Rescia, S.

    1997-11-01

    Proposed experiments for the Large Hadron Collider (LHC) set new demands on calorimeter readout electronics. The very high energy and large luminosity of the collider call for a large number of high speed, large dynamic range readout channels which have to be carefully synchronized. The ATLAS liquid argon collaboration, after more than 5 years of R and D developments has now finalized the architecture of its front end and read-out electronics, which have been written down in its Technical Design Report (TDR). An overview is presented.

  11. Temperature-induced isostructural phase transition, associated large negative volume expansion, and the existence of a critical point in the phase diagram of the multiferroic (1--x)BiFeO3-xPbTiO3 solid solution system

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Shuvrajyoti; Taji, Kazuaki; Moriyoshi, Chikako; Kuroiwa, Yoshihiro; Pandey, Dhananjai

    2011-09-01

    We report here an unusual ferroelectric to ferroelectric isostructural phase transition and associated giant negative thermal expansion (NTE) for the tetragonal composition x = 0.31 closest to the morphotropic phase boundary (MPB) of the multiferroic (1-x)BiFeO3-xPbTiO3 (BF-xPT) solid solution system. It is shown that the room temperature tetragonal phase (T1) of BF-0.31PT with extremely large tetragonality undergoes a first-order isostructural phase transition to another tetragonal phase (T2) with lower tetragonality without losing the P4mm space group symmetry and the occupied Wyckoff positions. The T2 phase finally transforms into the paraelectric cubic phase at still higher temperatures. Using group theoretical considerations, we show that the observed atomic displacements associated with this isostructural phase transition correspond to specific irreducible representations of the P4mm space group at its Brillouin zone center, and as such this transition may be phonon driven. Pronounced anomalies in the thermal displacement parameters at the T1 to T2 transition provide evidence for such a phonon-mediated isostructural phase transition. The high tetragonality ferroelectric phase (T1) of BF-0.31PT shows the largest NTE coefficient reported so far in the mixed BF-xPT system. The isostructural transition is shown to persist for tetragonal compositions of BF-xPT up to x = 0.60. A complete phase diagram of the BF-xPT system showing the existence of a critical point at T ˜ 677 K for x ≈ 0.63 is also presented.

  12. 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.

  13. 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.

  14. 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

    SciTech Connect

    Yasumoto, M. Ohta, M.; Kawamura, Y.; Hatayama, A.

    2014-02-15

    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.

  15. Renormalized large-n solution of the U(n)xU(n) linear sigma model in the broken symmetry phase

    SciTech Connect

    Fejo''s, G.; Patkos, A.

    2010-08-15

    Dyson-Schwinger equations for the U(n)xU(n) symmetric matrix sigma model reformulated with two auxiliary fields in a background breaking the symmetry to U(n) are studied in the so-called bare vertex approximation. A large n solution is constructed under the supplementary assumption so that the scalar components are much heavier than the pseudoscalars. The renormalizability of the solution is investigated by explicit construction of the counterterms.

  16. 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.

  17. 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. PMID:19369023

  18. Ultratraces analysis of organochlorine pesticides in drinking water by solid phase extraction coupled with large volume injection/gas chromatography/mass spectrometry.

    PubMed

    Brondi, Silvia H G; Spoljaric, Fernanda C; Lanças, Fernando M

    2005-11-01

    This study describes an SPE coupled with large volume injection (LVI) analytical method for the analysis of organochlorine pesticides, BHC (alpha, beta, delta), aldrin, endosulfan (alpha, beta), endrin, dieldrin, and DDT, from aqueous samples. Determination was carried out by GC with MS. The LODs of organochlorine pesticides were determined at 10 ng/L concentration levels, and the results show that SPE-LVI-GC/MS has the potential to accurately determine organochlorine pesticides in water, as it avoids analyte classes in the various steps of a typical extraction procedure.

  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

    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.

  2. 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.

  3. 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.

  4. Assessing the impact of safety monitoring on the efficacy analysis in large Phase III group sequential trials with non-trivial safety event rate.

    PubMed

    Weng, Yanqiu; Palesch, Yuko Y; DeSantis, Stacia M; Zhao, Wenle

    2016-01-01

    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 (DSMC). A naïve group sequential design (GSD) 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 article, 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 GSD 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 DSMCs when they wish to deviate from the prespecified stopping boundaries based on safety measures. PMID:26010228

  5. 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.

  6. 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.

  7. Rb-Sr and Sm-Nd Studies of Olivine-Phyric Shergottites RBT 04262 and LAR 06319: Isotopic Evidence for Relationship to Enriched Basaltic Shergottites

    NASA Technical Reports Server (NTRS)

    Nyquist, L.E.; Shih, C.-Y.; Reese, Y.

    2009-01-01

    RBT 04262 and LAR 06319 are two Martian meteorites recently discovered in Antarctica. Both contain abundant olivines, and were classified as olivine-phyric shergottites. A detailed petrographic study of RBT 04262 suggested it should be reclassified as a lherzolitic shergottite. However, the moderately LREE-depleted REE distribution pattern indicated that it is closely related to enriched basaltic shergottites like Shergotty, Zagami, Los Angeles, etc. In earlier studies of a similarly olivinephyric shergottite NWA 1068 which contains 21% modal olivine, it was shown that it probably was produced from an enriched basaltic shergottite magma by olivine accumulation . As for LAR 06319, recent petrographic studies suggested that it is different from either lherzolitic shergottites or the highly LREE-depleted olivine-phyric shergottites. We performed Rb-Sr and Sm-Nd isotopic analyses on RBT 04262 and LAR 06319 to determine their crystallization ages and Sr and Nd isotopic signatures, and to better understand the petrogenetic relationships between them and other basaltic, lherzolitic and depleted olivine-phyric shergottites.

  8. 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

  9. 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.

  10. Locality and rapidity of the ultra-large elastic deformation of Nb nanowires in a NiTi phase-transforming matrix

    PubMed Central

    Wang, Shan; Cui, Lishan; Hao, Shijie; Jiang, Daqiang; Liu, Yinong; Liu, Zhenyang; Mao, Shengcheng; Han, Xiaodong; Ren, Yang

    2014-01-01

    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. PMID:25341619

  11. 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.

  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; 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 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. 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. PMID:23440877

  14. 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.

  15. 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.

  16. Large-scale, solution-phase growth of semiconductor nanocrystals into ultralong one-dimensional arrays and study of their electrical properties

    NASA Astrophysics Data System (ADS)

    Ma, Yuchao; Xue, Mengmeng; Shi, Jiahua; Tan, Yiwei

    2014-05-01

    One-dimensional (1D) assemblies of semiconductor nanocrystals (NCs) represent an important kind of 1D nanomaterial system due to their potential for exploring novel and enhanced electronic and photonic performances of devices. Herein, we present mass fabrication of a series of 1D arrays of CdSe and PbSe NCs on a large length scale with ultralong, aligned Se nanowires (NWs) as both the reactant and structure-directing template. The 1D self-assembly patterns are the anchored growth of CdSe quantum dots (QDs) on the surface of Se NWs (i.e., 1D Se NWs/CdSe QDs core-shell heterostructure) and 1D aggregates of unsupported PbSe NCs formed by substantially increased collective particle-particle interactions. The size of CdSe QDs and shape of PbSe NCs in the 1D arrays can be effectively controlled by varying the synthetic conditions. Room temperature electrical measurements on the 1D Se/CdSe heterostructure field effect transistors (FETs) exhibit a pronounced improvement in the on/off ratio, device carrier mobility, and transconductance compared to the Se NW FETs fabricated in parallel. Furthermore, upon visible light excitation, the photocurrent from the Se/CdSe heterostructure FETs responses sharply (small time constant) and increases linearly with increasing the light intensity, indicating excellent photoconductive properties.One-dimensional (1D) assemblies of semiconductor nanocrystals (NCs) represent an important kind of 1D nanomaterial system due to their potential for exploring novel and enhanced electronic and photonic performances of devices. Herein, we present mass fabrication of a series of 1D arrays of CdSe and PbSe NCs on a large length scale with ultralong, aligned Se nanowires (NWs) as both the reactant and structure-directing template. The 1D self-assembly patterns are the anchored growth of CdSe quantum dots (QDs) on the surface of Se NWs (i.e., 1D Se NWs/CdSe QDs core-shell heterostructure) and 1D aggregates of unsupported PbSe NCs formed by substantially

  17. 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

  18. The receptor protein tyrosine phosphatase HmLAR1 is up-regulated in the CNS of the adult medicinal leech following injury and is required for neuronal sprouting and regeneration.

    PubMed

    Sethi, Jasmine; Zhao, Bailey; Cuvillier-Hot, Virginie; Boidin-Wichlacz, Céline; Salzet, Michel; Macagno, Eduardo R; Baker, Michael W

    2010-12-01

    LAR-like receptor protein tyrosine phosphatases (RPTPs), which are abundantly expressed in the nervous systems of most if not all bilaterian animals thus far examined, have been implicated in regulating a variety of critical neuronal processes. These include neuronal pathfinding, adhesion and synaptogenesis during development and, in adult mammals, neuronal regeneration. Here we explored a possible role of a LAR-like RPTP (HmLAR1) in response to mechanical trauma in the adult nervous system of the medicinal leech. In situ hybridization and QPCR analyses of HmLAR1 expression in individual segmental ganglia revealed a significant up-regulation in receptor expression following CNS injury, both in situ and following a period in vitro. Furthermore, we observed up-regulation in the expression of the leech homologue of the Abelson tyrosine kinase, a putative signaling partner to LAR receptors, but not among other tyrosine kinases. The effects on neuronal regeneration were assayed by comparing growth across a nerve crush by projections of individual dorsal P neurons (P(D)) following single-cell injection of interfering RNAs against the receptor or control RNAs. Receptor RNAi led to a significant reduction in HmLAR1 expression by the injected cells and resulted in a significant decrease in sprouting and regenerative growth at the crush site relative to controls. These studies extend the role of the HmLARs from leech neuronal development to adult neuronal regeneration and provide a platform to investigate neuronal regeneration and gene regulation at the single cell level. PMID:20708686

  19. The receptor protein tyrosine phosphatase HmLAR1 is up-regulated in the CNS of the adult medicinal leech following injury and is required for neuronal sprouting and regeneration.

    PubMed

    Sethi, Jasmine; Zhao, Bailey; Cuvillier-Hot, Virginie; Boidin-Wichlacz, Céline; Salzet, Michel; Macagno, Eduardo R; Baker, Michael W

    2010-12-01

    LAR-like receptor protein tyrosine phosphatases (RPTPs), which are abundantly expressed in the nervous systems of most if not all bilaterian animals thus far examined, have been implicated in regulating a variety of critical neuronal processes. These include neuronal pathfinding, adhesion and synaptogenesis during development and, in adult mammals, neuronal regeneration. Here we explored a possible role of a LAR-like RPTP (HmLAR1) in response to mechanical trauma in the adult nervous system of the medicinal leech. In situ hybridization and QPCR analyses of HmLAR1 expression in individual segmental ganglia revealed a significant up-regulation in receptor expression following CNS injury, both in situ and following a period in vitro. Furthermore, we observed up-regulation in the expression of the leech homologue of the Abelson tyrosine kinase, a putative signaling partner to LAR receptors, but not among other tyrosine kinases. The effects on neuronal regeneration were assayed by comparing growth across a nerve crush by projections of individual dorsal P neurons (P(D)) following single-cell injection of interfering RNAs against the receptor or control RNAs. Receptor RNAi led to a significant reduction in HmLAR1 expression by the injected cells and resulted in a significant decrease in sprouting and regenerative growth at the crush site relative to controls. These studies extend the role of the HmLARs from leech neuronal development to adult neuronal regeneration and provide a platform to investigate neuronal regeneration and gene regulation at the single cell level.

  20. 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.

  1. 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.

  2. Validation of the ATLAS hadronic calibration with the LAr End-Cap beam tests data

    NASA Astrophysics Data System (ADS)

    Barillari, Teresa

    2009-04-01

    The high granularity of the ATLAS calorimeter and the large number of expected particles per event require a clustering algorithm that is able to suppress noise and pile-up efficiently. Therefore the cluster reconstruction is the essential first step in the hadronic calibration. The identification of electromagnetic components within a hadronic cluster using cluster shape variables is the next step in the hadronic calibration procedure. Finally the energy density of individual cells is used to assign the proper weight to correct for the invisible energy deposits of hadrons due to the non-compensating nature of the ATLAS calorimeter and to correct for energy losses in material non instrumented with read-out. The weighting scheme employs the energy density in individual cells. Therefore the validation of the monte carlo simulation, which is used to define the weighting parameters and energy correction algorithms, is an essential step in the hadronic calibration procedure. Pion data, obtained in a beam test corresponding to the pseudorapidity region 2.5 < |η| < 4.0 in ATLAS and in the energy range 40 GeV <= E <= 200 GeV, have been compared with monte carlo simulations, using the full ATLAS hadronic calibration procedure.

  3. Rituximab plus gemcitabine and oxaliplatin in patients with refractory/relapsed diffuse large B-cell lymphoma who are not candidates for high-dose therapy. A phase II Lymphoma Study Association trial.

    PubMed

    Mounier, Nicolas; El Gnaoui, Taoufik; Tilly, Hervé; Canioni, Danièle; Sebban, Catherine; Casasnovas, René-Olivier; Delarue, Richard; Sonet, Anne; Beaussart, Pauline; Petrella, Tony; Castaigne, Sylvie; Bologna, Serge; Salles, Gilles; Rahmouni, Alain; Gaulard, Philippe; Haioun, Corinne

    2013-11-01

    A previous pilot study with rituximab, gemcitabine and oxaliplatin showed promising activity in patients with refractory/relapsed B-cell lymphoma. We, therefore, conducted a phase II study to determine whether these results could be reproduced in a multi-institutional setting. This phase II study included 49 patients with refractory (n=6) or relapsing (n=43) diffuse large B-cell lymphoma. The median age of the patients was 69 years. Prior treatment included rituximab in 31 (63%) and autologous transplantation in 17 (35%) patients. International Prognostic Index at enrollment was >2 in 34 patients (71%). The primary endpoint was overall response rate after four cycles of treatment. Patients were planned to receive eight cycles if they reached at least partial remission after four cycles. After four cycles 21 patients (44%) were in complete remission and 8 (17%) in partial remission, resulting in an overall response rate of 61%. Factors significantly affecting overall response rate were early (<1 year) progression/relapse (18% versus 54%; P=0.001) and prior exposure to rituximab (23% versus 65%; P=0.004). Five-year progression-free and overall survival rates were 12.8% and 13.9%, respectively. Rituximab, gemcitabine and oxaliplatin were well tolerated with grade 3-4 infectious episodes in 22% of the cycles. These results are the first confirmation from a multicenter study that rituximab, gemcitabine and oxaliplatin provide a consistent response rate in patients with refractory/relapsed diffuse large B-cell lymphoma. This therapy can now be considered as a platform for new combinations with targeted treatments. This trial was registered at clinicaltrial.gov under #NCT00169195. PMID:23753028

  4. Rituximab plus gemcitabine and oxaliplatin in patients with refractory/relapsed diffuse large B-cell lymphoma who are not candidates for high-dose therapy. A phase II Lymphoma Study Association trial

    PubMed Central

    Mounier, Nicolas; El Gnaoui, Taoufik; Tilly, Hervé; Canioni, Danièle; Sebban, Catherine; Casasnovas, René-Olivier; Delarue, Richard; Sonet, Anne; Beaussart, Pauline; Petrella, Tony; Castaigne, Sylvie; Bologna, Serge; Salles, Gilles; Rahmouni, Alain; Gaulard, Philippe; Haioun, Corinne

    2013-01-01

    A previous pilot study with rituximab, gemcitabine and oxaliplatin showed promising activity in patients with refractory/relapsed B-cell lymphoma. We, therefore, conducted a phase II study to determine whether these results could be reproduced in a multi-institutional setting. This phase II study included 49 patients with refractory (n=6) or relapsing (n=43) diffuse large B-cell lymphoma. The median age of the patients was 69 years. Prior treatment included rituximab in 31 (63%) and autologous transplantation in 17 (35%) patients. International Prognostic Index at enrollment was >2 in 34 patients (71%). The primary endpoint was overall response rate after four cycles of treatment. Patients were planned to receive eight cycles if they reached at least partial remission after four cycles. After four cycles 21 patients (44%) were in complete remission and 8 (17%) in partial remission, resulting in an overall response rate of 61%. Factors significantly affecting overall response rate were early (<1 year) progression/relapse (18% versus 54%; P=0.001) and prior exposure to rituximab (23% versus 65%; P=0.004). Five-year progression-free and overall survival rates were 12.8% and 13.9%, respectively. Rituximab, gemcitabine and oxaliplatin were well tolerated with grade 3–4 infectious episodes in 22% of the cycles. These results are the first confirmation from a multicenter study that rituximab, gemcitabine and oxaliplatin provide a consistent response rate in patients with refractory/relapsed diffuse large B-cell lymphoma. This therapy can now be considered as a platform for new combinations with targeted treatments. This trial was registered at clinicaltrial.gov under #NCT00169195. PMID:23753028

  5. 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.

  6. 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). PMID

  7. Analysis of β-blockers in groundwater using large-volume injection coupled-column reversed-phase liquid chromatography with fluorescence detection and liquid chromatography time-of-flight mass spectrometry.

    PubMed

    Galera, María M; Vázquez, Piedad P; Vázquez, María del Mar P; García, María Dolores G; Amate, Carmen F

    2011-08-01

    Atenolol, nadolol, metoprolol, bisoprolol and betaxolol were simultaneously determined in groundwater samples by large-volume injection coupled-column reversed-phase liquid chromatography with fluorescence detection (LVI-LC-LC-FD) and liquid chromatography-time-of-flight mass spectrometry (LC-TOF-MS). The LVI-LC-LC-FD method combines analyte isolation, preconcentration and determination into a single step. Significant reductions in costs for sample pre-treatment (solvent and solid phases for clean up) and method development times are also achieved. Using LC-TOF-MS, accurate mass measurements within 3 ppm error were obtained for all of the β-blockers studied. Empirical formula information can be obtained by this method, allowing the unequivocal identification of the target compounds in the samples. To increase the sensitivity, a solid-phase extraction step with Oasis MCX cartridge was carried out yielding recoveries of 79-114% (n=5) with RSD 2-7% for the LC-TOF-MS method. SPE gives a high purification of β-blockers compared with the existing methods. A 100% methanol wash was allowed for these compounds with no loss of analytes. Limit of quantification was 1-7 ng/L for LVI-LC-LC-FD and 0.25-5 ng/L for LC-TOF-MS. As a result of selective extraction and effective removal of coextractives, no matrix effect was observed in LVI-LC-LC-FD and LC-TOF-MS analyses. The methods were applied to detect and quantify β-blockers in groundwater samples of Almería (Spain).

  8. 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

  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

    Finger, Holger; Bönstrup, Marlene; Cheng, Bastian; Messé, Arnaud; Hilgetag, Claus; Thomalla, Götz; Gerloff, Christian; König, Peter

    2016-08-01

    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. Comparison of semipermeable membrane device (SPMD) and large-volume solid-phase extraction techniques to measure water concentrations of 4,4'-DDT, 4,4'-DDE, and 4,4'-DDD in Lake Chelan, Washington.

    PubMed

    Ellis, Steven G; Booij, Kees; Kaputa, Mike

    2008-07-01

    Semipermeable membrane devices (SPMDs) spiked with the performance reference compound PCB29 were deployed 6.1 m above the sediments of Lake Chelan, Washington, for a period of 27 d, to estimate the dissolved concentrations of 4,4'-DDT, 4,4'-DDE, and 4,4'-DDD. Water concentrations were estimated using methods proposed in 2002 and newer equations published in 2006 to determine how the application of the newer equations affects historical SPMD data that used the older method. The estimated concentrations of DDD, DDE, and DDD calculated using the older method were 1.5-2.9 times higher than the newer method. SPMD estimates from both methods were also compared to dissolved and particulate DDT concentrations measured directly by processing large volumes of water through a large-volume solid-phase extraction device (Infiltrex 300). SPMD estimates of DDD+DDE+DDT (SigmaDDT) using the older and newer methods were lower than Infiltrex concentrations by factors of 1.1 and 2.3, respectively. All measurements of DDT were below the Washington State water quality standards for the protection of human health (0.59 ng l(-1)) and aquatic life (1.0 ng l(-1)).

  11. New method for rapid solid-phase extraction of large-volume water samples and its application to non-target screening of North Sea water for organic contaminants by gas chromatography-mass spectrometry.

    PubMed

    Weigel, S; Bester, K; Hühnerfuss, H

    2001-03-30

    A method has been developed that allows the solid-phase extraction of microorganic compounds from large volumes of water (10 l) for non-target analysis of filtered seawater. The filtration-extraction system is operated with glass fibre filter candles and the polymeric styrene-divinylbenzene sorbent SDB-1 at flow-rates as high as 500 ml/min. Recovery studies carried out for a couple of model substances covering a wide range of polarity and chemical classes revealed a good performance of the method. Especially for polar compounds (log Kow 3.3-0.7) quantitative recovery was achieved. Limits of detection were between 0.1 and 0.7 ng/l in the full scan mode of the MS. The suitability of the method for the analysis of marine water samples is demonstrated by the non-target screening of water from the German Bight for the presence of organic contaminants. In the course of this screening a large variety of substances was identified including pesticides, industrial chemicals and pharmaceuticals. For some of the identified compounds their occurrence in marine ecosystems has not been reported before, such as dichloropyridines, carbamazepine, propyphenazone and caffeine.

  12. 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

  13. Thinking large.

    PubMed

    Devries, Egbert

    2016-05-01

    Egbert Devries was brought up on a farm in the Netherlands and large animal medicine has always been his area of interest. After working in UK practice for 12 years he joined CVS and was soon appointed large animal director with responsibility for building a stronger large animal practice base. PMID:27154956

  14. Phase II clinical trial of pasireotide long-acting repeatable in patients with metastatic neuroendocrine tumors

    PubMed Central

    Cives, M; Kunz, P L; Morse, B; Coppola, D; Schell, M J; Campos, T; Nguyen, P T; Nandoskar, P; Khandelwal, V; Strosberg, J R

    2015-01-01

    Pasireotide long-acting repeatable (LAR) is a novel somatostatin analog (SSA) with avid binding affinity to somatostatin receptor subtypes 1, 2, 3 (SSTR1,2,3) and 5 (SSTR5). Results from preclinical studies indicate that pasireotide can inhibit neuroendocrine tumor (NET) growth more robustly than octreotide in vitro. This open-label, phase II study assessed the clinical activity of pasireotide in treatment-naïve patients with metastatic grade 1 or 2 NETs. Patients with metastatic pancreatic and extra-pancreatic NETs were treated with pasireotide LAR (60 mg every 4 weeks). Previous systemic therapy, including octreotide and lanreotide, was not permitted. Tumor assessments were performed every 3 months using Response Evaluation Criteria in Solid Tumors (RECIST) criteria. The primary endpoint was progression-free survival (PFS). The secondary endpoints included overall survival (OS), overall radiographic response rate (ORR), and safety. Twenty-nine patients were treated with pasireotide LAR (60 mg every 4 weeks) and 28 were evaluable for response. The median PFS was 11 months. The most favorable effect was observed in patients with low hepatic tumor burden, normal baseline chromogranin A, and high tumoral SSTR5 expression. Median OS has not been reached; the 30-month OS rate was 70%. The best radiographic response was partial response in one patient (4%), stable disease in 17 patients (60%), and progressive disease in ten patients (36%). Although grade 3/4 toxicities were rare, pasireotide LAR treatment was associated with a 79% rate of hyperglycemia including 14% grade 3 hyperglycemia. Although pasireotide appears to be an effective antiproliferative agent in the treatment of advanced NETs, the high incidence of hyperglycemia raises concerns regarding its suitability as a first-line systemic agent in unselected patients. SSTR5 expression is a potentially predictive biomarker for response. PMID:25376618

  15. 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. PMID:18445999

  16. A Phase II Trial of R-CHOP Followed by Radioimmunotherapy for Early Stage (Stages I/II) Diffuse Large B-Cell Non-Hodgkin Lymphoma: ECOG3402

    PubMed Central

    Witzig, Thomas E.; Hong, Fangxin; Micallef, Ivana N.; Gascoyne, Randy D.; Dogan, Ahmet; Wagner, Henry; Kahl, Brad S.; Advani, Ranjana H.; Horning, Sandra J.

    2015-01-01

    Summary Patients with early stage diffuse large B-cell lymphoma (DLBCL) receive RCHOP alone or with involved field radiotherapy (IFRT). Anti-CD20 radioimmunotherapy (RIT) delivers radiation to microscopic sites outside of known disease. This phase II study aimed to achieve a functional CR rate of ≥75% to RCHOP and 90Yttrium-ibritumomab tiuxetan RIT. Patients with stages I/II DLBCL received 4–6 cycles of RCHOP followed by RIT (0.4 mCi/kg); patients with PET positive sites of disease after RCHOP/RIT received 30Gy IFRT. Of the 62 patients enrolled; 53 were eligible. 42% (22/53) had stage I/IE; 58% (31/53) stage II/IIE. After RCHOP, 79% (42/53) were in CR/CRu. Forty–eight patients proceeded to RIT and one patient in PR after RIT received IFRT and achieved a CR. The best response after RCHOP+RIT in all 53 patients was a functional CR rate of 89% (47/53; 95% CI:77–96%). With a median follow-up of 5.9 years, 7 (13%) patients have progressed and 4 (8%) have died (2 with DLBCL). At 5 years, 78% of patients remain in remission and 94% are alive. Chemoimmunotherapy and RIT is an active regimen for early stage DLBCL patients. Eighty-nine% of patients achieved functional CR without the requirement of IFRT. This regimen is worthy of further study for early stage DLBCL in a phase III trial. PMID:25974212

  17. First demonstration of imaging cosmic muons in a two-phase Liquid Argon TPC using an EMCCD camera and a THGEM

    NASA Astrophysics Data System (ADS)

    Mavrokoridis, K.; Carroll, J.; McCormick, K. J.; Paudyal, P.; Roberts, A.; Smith, N. A.; Touramanis, C.

    2015-10-01

    Colossal two-phase Liquid Argon Time Projection Chambers (LAr TPCs) are a proposed option for future long-baseline neutrino experiments. This study illustrates the feasibility of using an EMCCD camera to capture light induced by single cosmic events in a two-phase LAr TPC employing a THGEM. An Andor iXon Ultra 897 EMCCD camera was externally mounted via a borosilicate glass viewport on the Liverpool two-phase LAr TPC. The camera successfully captured the secondary scintillation light produced at the THGEM holes that had been induced by cosmic events. The light collection capability of the camera for various EMCCD gains was assessed. For a THGEM gain of 64 and an EMCCD gain of 1000, clear images were captured with an average signal-to-noise ratio of 6. Preliminary 3D reconstruction of straight cosmic muon tracks has been performed by combining the camera images, PMT signals and THGEM charge data. Reconstructed cosmic muon tracks were used to determine THGEM gain and to calibrate the intensity levels of the EMCCD image.

  18. Phase II open label study of the oral vascular endothelial growth factor-receptor inhibitor PTK787/ZK222584 (vatalanib) in adult patients with refractory or relapsed diffuse large B-cell lymphoma.

    PubMed

    Brander, Danielle; Rizzieri, David; Gockerman, Jon; Diehl, Louis; Shea, Thomas Charles; Decastro, Carlos; Moore, Joseph O; Beaven, Anne

    2013-12-01

    PTK787/ZK222584 (vatalanib), an orally active inhibitor of vascular endothelial growth factor receptors (VEGFRs), was evaluated in this phase II study of 20 patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL). Patients received once-daily PTK787/ZK222584 at a target dose of 1250 mg. Eighteen patients were evaluable for response: one patient had a complete response (CR), six patients had stable disease but subsequently progressed, 10 patients had progressive disease by three cycles and one subject withdrew before response evaluation. The patient who attained a CR underwent autologous stem cell transplant and remains disease-free 76 months after study completion. There were no grade 4 toxicities. Grade 3 thrombocytopenia occurred in 20% and grade 3 hypertension occurred in 10%. There were no episodes of grade 3 proteinuria. In conclusion, PTK787/ZK222584 was well tolerated in a heavily pretreated population of patients with DLBCL, although its therapeutic potential as a single agent in DLBCL appears limited. PMID:23488610

  19. 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.

  20. Chondroitin Sulfate Proteoglycans Negatively Modulate Spinal Cord Neural Precursor Cells by Signaling Through LAR and RPTPσ and Modulation of the Rho/ROCK Pathway.

    PubMed

    Dyck, Scott M; Alizadeh, Arsalan; Santhosh, Kallivalappil T; Proulx, Evan H; Wu, Chia-Lun; Karimi-Abdolrezaee, Soheila

    2015-08-01

    Multipotent adult neural precursor cells (NPCs) have tremendous intrinsic potential to repair the damaged spinal cord. However, evidence shows that the regenerative capabilities of endogenous and transplanted NPCs are limited in the microenvironment of spinal cord injury (SCI). We previously demonstrated that injury-induced upregulation of matrix chondroitin sulfate proteoglycans (CSPGs) restricts the survival, migration, integration, and differentiation of NPCs following SCI. CSPGs are long-lasting components of the astroglial scar that are formed around the lesion. Our recent in vivo studies demonstrated that removing CSPGs from the SCI environment enhances the potential of transplanted and endogenous adult NPCs for spinal cord repair; however, the mechanisms by which CSPGs regulate NPCs remain unclear. In this study, using in vitro models recapitulating the extracellular matrix of SCI, we investigated the direct role of CSPGs in modulating the properties of adult spinal cord NPCs. We show that CSPGs significantly decrease NPCs growth, attachment, survival, proliferation, and oligodendrocytes differentiation. Moreover, using genetic models, we show that CSPGs regulate NPCs by signaling on receptor protein tyrosine phosphate sigma (RPTPσ) and leukocyte common antigen-related phosphatase (LAR). Intracellularly, CSPGs inhibitory effects are mediated through Rho/ROCK pathway and inhibition of Akt and Erk1/2 phosphorylation. Downregulation of RPTPσ and LAR and blockade of ROCK in NPCs attenuates the inhibitory effects of CSPGS. Our work provide novel evidence uncovering how upregulation of CSPGs challenges the response of NPCs in their post-SCI niche and identifies new therapeutic targets for enhancing NPC-based therapies for SCI repair.

  1. 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

  2. Dynamic of large reflectors

    NASA Astrophysics Data System (ADS)

    Picard, P.; Dauviau, C.; Lefebvre, J. D.; Garnier, C.; Truchi, C.

    1991-10-01

    Work in the field of the unfurlable mesh reflectors as part of the dynamic of large reflectors project is presented. These studies use the unfurlable reflector design developed since 1983: gilded molybdenum reflective mesh supported by a deployable truss. From this strong background two specific critical points are studied: the deployment phase, where, for a deployment test, the test measurements are correlated with dynamic software predictions and the deployment bench chosen uses a 0 g compensation device by helium balloons; the antenna deployed configuration, where the interaction between a large structure and the attitude and orbit control subsystem is analyzed.

  3. 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…

  4. Noisy quantum phase communication channels

    NASA Astrophysics Data System (ADS)

    Teklu, Berihu; Trapani, Jacopo; Olivares, Stefano; Paris, Matteo G. A.

    2015-06-01

    We address quantum phase channels, i.e communication schemes where information is encoded in the phase-shift imposed to a given signal, and analyze their performances in the presence of phase diffusion. We evaluate mutual information for coherent and phase-coherent signals, and for both ideal and realistic phase receivers. We show that coherent signals offer better performances than phase-coherent ones, and that realistic phase channels are effective ones in the relevant regime of low energy and large alphabets.

  5. 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.

  6. Large ethics.

    PubMed

    Chambers, David W

    2008-01-01

    This essay presents an alternative to the traditional view that ethics means judging individual behavior against standards of right and wrong. Instead, ethics is understood as creating ethical communities through the promises we make to each other. The "aim" of ethics is to demonstrate in our own behavior a credible willingness to work to create a mutually better world. The "game" of ethics then becomes searching for strategies that overlap with others' strategies so that we are all better for intending to act on a basis of reciprocal trust. This is a difficult process because we have partial, simultaneous, shifting, and inconsistent views of the world. But despite the reality that we each "frame" ethics in personal terms, it is still possible to create sufficient common understanding to prosper together. Large ethics does not make it a prerequisite for moral behavior that everyone adheres to a universally agreed set of ethical principles; all that is necessary is sufficient overlap in commitment to searching for better alternatives.

  7. Development and implementation of optimal filtering in a Virtex FPGA for the upgrade of the ATLAS LAr calorimeter readout

    NASA Astrophysics Data System (ADS)

    Stärz, S.

    2012-12-01

    In the context of upgraded read-out systems for the Liquid-Argon Calorimeters of the ATLAS detector, modified front-end, back-end and trigger electronics are foreseen for operation in the high-luminosity phase of the LHC. Accuracy and efficiency of the energy measurement and reliability of pile-up suppression are substantial when processing the detector raw-data in real-time. Several digital filter algorithms are investigated for their performance to extract energies from incoming detector signals and for the needs of the future trigger system. The implementation of fast, resource economizing, parameter driven filter algorithms in a modern Virtex FPGA is presented.

  8. 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...

  9. 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...

  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. 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.

  12. 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.

  13. Enhanced in vivo IgE production and T cell polarization toward the type 2 phenotype in association with indoor exposure to VOC: results of the LARS study.

    PubMed

    Lehmann, I; Rehwagen, M; Diez, U; Seiffart, A; Rolle-Kampczyk, U; Richter, M; Wetzig, H; Borte, M; Herbarth, O

    2001-12-01

    The association between indoor exposure to volatile organic compounds (VOC), prevalence of allergic sensitization and cytokine secretion profile of peripheral T cells was studied in 3 year old children of the LARS study (Leipzig Allergy Risk Children Study) to investigate the role of VOC exposure as a risk factor for the development of atopic disease. Indoor VOC exposure was measured over a period of 4 weeks in infants' bedrooms using a passive sampling system. Specific IgE antibodies to food, indoor and outdoor allergens were measured by the Pharmacia CAP system and correlated to VOC exposure (n = 120). In addition, cytokine producing peripheral T cells (interleukin(IL)-4, interferon(IFN)-gamma) were measured in a subgroup of 28 children by means of intracellular cytokine staining. For the first time we were able to show that exposure to alkanes (C6, C9, C10) and aromatic compounds (toluene, o-xylene, m + p-xylene, 2-, 3- and 4-ethyl-toluene, chlorobenzene) may contribute to the risk of allergic sensitization to the food allergens milk and egg white (Odds ratios between 5.7 and 11.2). Moreover, significantly reduced numbers of CD3+/CD8+ peripheral T cells were found in children exposed to alkanes (C9-C13), naphthalene and chlorobenzene. Exposure to benzene, ethylbenzene and chlorobenzene was associated with higher percentages of IL-4 producing CD3+ T cells. Both an increase in IL-4 producing type 2 T cells and a reduction of IFN-gamma producing type 1 T cells may contribute to a type 2 skewed memory in response to allergens. Therefore, we suggest exposure to VOCs in association with allergic sensitization to be mediated by a T cell polarization toward the type 2 phenotype.

  14. 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.

  15. 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

  16. The contraction of granules of nanoporous super-cross-linked polystyrene sorbents as a result of the exclusion of large-sized mineral electrolyte ions from the polymer phase

    NASA Astrophysics Data System (ADS)

    Pastukhov, A. V.; Davankov, V. A.; Tsyurupa, M. P.; Blinnikova, Z. K.; Kavalerskaya, N. E.

    2009-03-01

    The deformation of neutral super-cross-linked polystyrene sorbents and ionites based on styrene-divinylbenzene gel-type copolymers brought in contact with concentrated solutions of HCl, H3PO4, NaOH, NH4Cl, (NH4)2SO4, and LiCl electrolytes was studied by dilatometry for separate spherical granules. Considerable contraction of super-cross-linked polystyrene matrices swollen in water was observed in concentrated solutions containing large-sized lithium, sulfate, and phosphate ions. Volume compressive strain correlated with the size of excluded hydrated ions. The contraction effect was caused by the difference in the osmotic pressure of water in thin pores and water in concentrated solutions filling large pores. The exclusion effect ignored earlier should also influence the degree of ion exchange and volume deformation of standard ion-exchange resins brought in contact with solutions of various electrolytes.

  17. 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+}.

  18. Large area liquid argon detectors for interrogation systems

    NASA Astrophysics Data System (ADS)

    Gary, Charles; Kane, Steve; Firestone, Murray I.; Smith, Gregory; Gozani, Tsahi; Brown, Craig; Kwong, John; King, Michael J.; Nikkel, James A.; McKinsey, Dan

    2013-04-01

    Measurements of the efficiency, pulse shape, and energy and time resolution of liquid argon (LAr) detectors are presented. Liquefied noble gas-based (LNbG) detectors have been developed for the detection of dark matter and neutrinoless double-beta decay. However, the same qualities that make LNbG detectors ideal for these applications, namely their size, cost, efficiency, pulse shape discrimination and resolution, make them promising for portal screening and the detection of Special Nuclear Materials (SNM). Two 18-liter prototype detectors were designed, fabricated, and tested, one with pure LAr and the other doped with liquid Xe (LArXe). The LArXe detector presented the better time and energy resolution of 3.3 ns and 20% at 662 KeV, respectively. The total efficiency of the detector was measured to be 35% with 4.5% of the total photons detected in the photopeak.

  19. Large area liquid argon detectors for interrogation systems

    SciTech Connect

    Gary, Charles; Kane, Steve; Firestone, Murray I.; Smith, Gregory; Gozani, Tsahi; Brown, Craig; Kwong, John; King, Michael J.; Nikkel, James A.; McKinsey, Dan

    2013-04-19

    Measurements of the efficiency, pulse shape, and energy and time resolution of liquid argon (LAr) detectors are presented. Liquefied noble gas-based (LNbG) detectors have been developed for the detection of dark matter and neutrinoless double-beta decay. However, the same qualities that make LNbG detectors ideal for these applications, namely their size, cost, efficiency, pulse shape discrimination and resolution, make them promising for portal screening and the detection of Special Nuclear Materials (SNM). Two 18-liter prototype detectors were designed, fabricated, and tested, one with pure LAr and the other doped with liquid Xe (LArXe). The LArXe detector presented the better time and energy resolution of 3.3 ns and 20% at 662 KeV, respectively. The total efficiency of the detector was measured to be 35% with 4.5% of the total photons detected in the photopeak.

  20. Expanding the potential of chiral chromatography for high-throughput screening of large compound libraries by means of sub-2μm Whelk-O 1 stationary phase in supercritical fluid conditions.

    PubMed

    Sciascera, Luca; Ismail, Omar; Ciogli, Alessia; Kotoni, Dorina; Cavazzini, Alberto; Botta, Lorenzo; Szczerba, Ted; Kocergin, Jelena; Villani, Claudio; Gasparrini, Francesco

    2015-02-27

    With the aim of exploring the potential of ultra-fast chiral chromatography for high-throughput analysis, the new sub-2 micron Whelk-O 1 chiral stationary phase (CSP) has been employed in supercritical fluid conditions to screen 129 racemates, mainly of pharmaceutical interest. By using a 5-cm long column (0.46cm internal diameter), a single co-solvent (MeOH) and a 7-min gradient elution, 85% of acidic and neutral analytes considered in this work have been successfully resolved, with resolution (Rs) larger than 2 in more than 65% of cases. Moreover, almost a half of basic samples that, for their own characteristics, are known to be difficult to separate on Whelk-O 1 CSP, have shown Rs greater than 0.3. The screening of the entire library could be accomplished in less than 24h (single run) with 63% of positive score. For well-resolved enantiomers (Rs roughly included between 1 and 3), we show that method transfer from gradient to isocratic conditions is straightforward. In many cases, isocratic ultra-fast separations (with analysis time smaller than 60s) have been achieved by simply employing, as isocratic mobile phase, the eluent composition at which the second enantiomer was eluted in gradient mode. By considering the extension and variety of the library in terms of chemico-physical and structural properties of compounds and numerousness, we believe that this work demonstrates the real potential of the technique for high-throughput enantioselective screening. PMID:25650355

  1. 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.

  2. 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%.

  3. The Large Millimeter Telescope

    NASA Astrophysics Data System (ADS)

    Hughes, David H.; Jáuregui Correa, Juan-Carlos; Schloerb, F. Peter; Erickson, Neal; Romero, Jose Guichard; Heyer, Mark; Reynoso, David Huerta; Narayanan, Gopal; Perez-Grovas, Alfonso Serrano; Souccar, Kamal; Wilson, Grant; Yun, Min

    2010-07-01

    This paper describes the current status of the Large Millimeter Telescope (LMT), the near-term plans for the telescope and the initial suite of instrumentation. The LMT is a bi-national collaboration between Mexico and the USA, led by the Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE) and the University of Massachusetts at Amherst, to construct, commission and operate a 50m-diameter millimeter-wave radio telescope. Construction activities are nearly complete at the 4600m LMT site on the summit of Volcán Sierra Negra, an extinct volcano in the Mexican state of Puebla. Full movement of the telescope, under computer control in both azimuth and elevation, has been achieved. The commissioning and scientific operation of the LMT is divided into two major phases. As part of phase 1, the installation of precision surface segments for millimeter-wave operation within the inner 32m-diameter of the LMT surface is now complete. The alignment of these surface segments is underway. The telescope (in its 32-m diameter format) will be commissioned later this year with first-light scientific observations at 1mm and 3mm expected in early 2011. In phase 2, we will continue the installation and alignment of the remainder of the reflector surface, following which the final commissioning of the full 50-m LMT will take place. The LMT antenna, outfitted with its initial complement of scientific instruments, will be a world-leading scientific research facility for millimeter-wave astronomy.

  4. 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)

  5. Phase Change

    NASA Technical Reports Server (NTRS)

    Hasan, Mohammad M.

    2004-01-01

    Recent workshops to define strategic research on critical issues in microgravity fluids and transport phenomena in support of mission orientated needs of NASA and many technical conferences over the years in support of fundamental research targeting NASA's long range missions goal have identified several phase change processes needed to design advanced space and planetary based systems for long duration operations Recommendation noted that phase change processes are profoundly affected by gravitational environment.

  6. Human exposure assessment to a large set of polymer additives through the analysis of urine by solid phase extraction followed by ultra high performance liquid chromatography coupled to tandem mass spectrometry.

    PubMed

    Pouech, Charlène; Kiss, Agneta; Lafay, Florent; Léonard, Didier; Wiest, Laure; Cren-Olivé, Cécile; Vulliet, Emmanuelle

    2015-12-01

    Polymer items are extensively present in the human environment. Humans may be consequently exposed to some compounds, such as additives, incorporated in these items. The objective of this work is to assess the human exposure to the main additives such as those authorized in the packaging for pharmaceutical products. The urinary matrix was selected to optimally answer this challenge because it has already been proven that the exposure to chemicals can be revealed by the analysis of this biological matrix. A multi-residue analytical method for the trace analysis at ng/mL in human urine was developed, and consisted of an extraction of analytes from urine by solid phase extraction (SPE) and an analysis by ultra-high performance liquid chromatography coupled to a tandem mass spectrometer (UHPLC-MS/MS). Even if the quantification of these compounds was an analytical challenge because of (i) the presence of these substances in the analytical process, (ii) the diversity of their physicochemical properties, and (iii) the complexity of the matrix, the optimized method exhibited quantification limits lower than 25ng/mL and recoveries between 51% and 120% for all compounds. The method was validated and applied to 52 human urines. To the best of our knowledge, this work presents the first study allowing the assessment of the occurrence of more than twenty polymer additives at ng/mL in human urine.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. Ulysses and IMP-8 Observations of Cosmic Rays and So-lar Energetic Particles from the South Pole to the North Pole of the Sun near Solar Maximum*

    NASA Astrophysics Data System (ADS)

    McKibben, R. B.; Connell, J. J.; Lopate, C.; Zhang, M.

    2001-12-01

    The High Energy Telescope (HET) of the Ulysses COSPIN experiment measures intensities of galactic cosmic rays and solar energetic particles (SEPs) with good energy and charge resolution at energies above about 30 MeV/n. Since passing over the South Polar regions of the Sun near solar maximum in late 2000 Ulysses has been rapidly traversing solar latitude in its so-called Fast Latitude Scan (FLS), passing through perihelion near the sun's equator in May 2001. Maximum northern latitude (80.2 deg N) will be reached in October 2001. HET observations since the onset of solar activity, including the South Polar pass and the first part of the FLS, show that SEPs from large events were commonly observed at both Ulysses and Earth (IMP-8) regardless of the radial, latitudinal, or longitudinal separations between Ulysses and Earth. During the decay phases of the events intensities were often almost equal at Ulysses and IMP, even when Ulysses was over the Sun's South Pole and the associated flare site was in the northern hemisphere. This suggests that propagation of particles across the average interplanetary magnetic field in the inner heliosphere is effective enough to relax longitudinal and latitudinal particle intensity gradients within a few days. For galactic cosmic rays, observations from the FLS so far show that latitudinal gradients resulting from solar modulation at solar maximum are <1%/degree, and are in fact consistent with zero to the accuracy of our measurements. The small gradients also suggest effective propagation in the latitudinal direction. We will report observations from the continuing FLS, give a first report of Ulysses observations over the sun's North Polar Regions, and discuss the significance of the results for models of energetic charged particle propagation through the heliosphere. * This work was supported in part by NASA Contract JPL-955432 and by NASA Grant NAG5-8032.

  13. Automating large-scale reactor systems

    SciTech Connect

    Kisner, R.A.

    1985-01-01

    This paper conveys a philosophy for developing automated large-scale control systems that behave in an integrated, intelligent, flexible manner. Methods for operating large-scale systems under varying degrees of equipment degradation are discussed, and a design approach that separates the effort into phases is suggested. 5 refs., 1 fig.

  14. 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. PMID:20517352

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Phase noise measurement of phase modulation microwave photonic links

    NASA Astrophysics Data System (ADS)

    Ye, Quanyi; Chen, Zhengyu; Xu, Zhiguo; Gao, Yingjie

    2015-10-01

    Microwave photonic links (MPLs) can provide many advantages over traditional coaxial and waveguide solutions due to its low loss, small size, lightweight, large bandwidth, superior stability and immunity to external interference. It has been considered in various applications such as: the transmission of radio frequency (RF) signal over optical carriers, video television transmission, radar and communication systems. Stability of phase of the microwave photonic links is a critical issue in several realistic applications. The delay line technique for phase noise measurement of phase modulation microwave photonic links is measured for the first time. Using this approach, the input signal noise and power supply noise can be effectively cancelled, and it does not require phase locking. The phase noise of a microwave photonic links with a 10 GHz sinusoidal signal is experimentally demonstrated.

  20. {sup 129}I Interlaboratory comparison: phase I and phase II

    SciTech Connect

    Caffee, M W; Roberts, M L

    1999-09-30

    An interlaboratory comparison exercise for {sup 129}I was organized and conducted. Nine laboratories participated in the exercise to either a full or limited extent. In Phase I of the comparison, 11 samples were measured. The suite of samples contained both synthetic ''standard type'' materials (i.e., AgI) and environmental materials. The isotopic {sup 129}I/{sup 127}I ratios of the samples varied from 10{sup {minus}8} to 10{sup {minus}14}. In this phase, each laboratory was responsible for its own chemical preparation of the samples. In Phase I, the {sup 129}I AMS measurements for prepared AgI were in good agreement. However, large discrepancies were seen in {sup 129}I AMS measurements of environmental samples. Because of the large discrepancies seen in the Phase I {sup 129}I intercomparison, a subsequent study was conducted. In Phase II of the {sup 129}I intercomparison, three separate laboratories prepared AgI from two environmental samples (IAEA 375 soil and maples leaves). Each laboratory used its own chemical preparation method with each of the methods being distinctly different. The resulting six samples (two sets of three) were then re-distributed to the participating {sup 129}I AMS facilities and {sup 129}I/{sup 127}I ratios measured. Results and discussion of both the Phase I and Phase II interlaboratory comparison are presented.

  1. A cosmic superfluid phase

    NASA Technical Reports Server (NTRS)

    Gradwohl, Ben-Ami

    1991-01-01

    The universe may have undergone a superfluid-like phase during its evolution, resulting from the injection of nontopological charge into the spontaneously broken vacuum. In the presence of vortices this charge is identified with angular momentum. This leads to turbulent domains on the scale of the correlation length. By restoring the symmetry at low temperatures, the vortices dissociate and push the charges to the boundaries of these domains. The model can be scaled (phenomenologically) to very low energies, it can be incorporated in a late time phase transition and form large scale structure in the boundary layers of the correlation volumes. The novel feature of the model lies in the fact that the dark matter is endowed with coherent motion. The possibilities of identifying this flow around superfluid vortices with the observed large scale bulk motion is discussed. If this identification is possible, then the definite prediction can be made that a more extended map of peculiar velocities would have to reveal large scale circulations in the flow pattern.

  2. 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.

  3. Athena: Assessment Phase Activities

    NASA Astrophysics Data System (ADS)

    Lumb, David; Ayre, Mark

    2015-09-01

    The Athena mission concept has been proposed by the community in response to science themes of the Hot and Energetic Universe. Unlike other, competitive, mission selection exercises this "Large" class observatory mission has essentially been pre-selected. Nevertheless it has to be demonstrated that Athena meets the programmatic constraints of 1Bn euro cost cap, and a readiness level appropriate for formal mission adoption by the end 2019. This should be confirmed through a Phase A study conducted with two parallel industry activities. We describe the technical and programmatic content of these and latest progress in space and ground segment definition.

  4. Optical encryption for large-sized images

    NASA Astrophysics Data System (ADS)

    Sanpei, Takuho; Shimobaba, Tomoyoshi; Kakue, Takashi; Endo, Yutaka; Hirayama, Ryuji; Hiyama, Daisuke; Hasegawa, Satoki; Nagahama, Yuki; Sano, Marie; Oikawa, Minoru; Sugie, Takashige; Ito, Tomoyoshi

    2016-02-01

    We propose an optical encryption framework that can encrypt and decrypt large-sized images beyond the size of the encrypted image using our two methods: random phase-free method and scaled diffraction. In order to record the entire image information on the encrypted image, the large-sized images require the random phase to widely diffuse the object light over the encrypted image; however, the random phase gives rise to the speckle noise on the decrypted images, and it may be difficult to recognize the decrypted images. In order to reduce the speckle noise, we apply our random phase-free method to the framework. In addition, we employ scaled diffraction that calculates light propagation between planes with different sizes by changing the sampling rates.

  5. Phase II Final Report

    SciTech Connect

    Schuknecht, Nate; White, David; Hoste, Graeme

    2014-09-11

    The SkyTrough DSP will advance the state-of-the-art in parabolic troughs for utility applications, with a larger aperture, higher operating temperature, and lower cost. The goal of this project was to develop a parabolic trough collector that enables solar electricity generation in the 2020 marketplace for a 216MWe nameplate baseload power plant. This plant requires an LCOE of 9¢/kWhe, given a capacity factor of 75%, a fossil fuel limit of 15%, a fossil fuel cost of $6.75/MMBtu, $25.00/kWht thermal storage cost, and a domestic installation corresponding to Daggett, CA. The result of our optimization was a trough design of larger aperture and operating temperature than has been fielded in large, utility scale parabolic trough applications: 7.6m width x 150m SCA length (1,118m2 aperture), with four 90mm diameter × 4.7m receivers per mirror module and an operating temperature of 500°C. The results from physical modeling in the System Advisory Model indicate that, for a capacity factor of 75%: The LCOE will be 8.87¢/kWhe. SkyFuel examined the design of almost every parabolic trough component from a perspective of load and performance at aperture areas from 500 to 2,900m2. Aperture-dependent design was combined with fixed quotations for similar parts from the commercialized SkyTrough product, and established an installed cost of $130/m2 in 2020. This project was conducted in two phases. Phase I was a preliminary design, culminating in an optimum trough size and further improvement of an advanced polymeric reflective material. This phase was completed in October of 2011. Phase II has been the detailed engineering design and component testing, which culminated in the fabrication and testing of a single mirror module. Phase II is complete, and this document presents a summary of the comprehensive work.

  6. 129I interlaboratory comparison: phase I and phase II results

    SciTech Connect

    Roberts, M.I.; Caffee, M.W.; Proctor, I.D.

    1997-07-01

    An interlaboratory comparison exercise for 129I was organized and conducted. A total of nine laboratories participated in the exercise to either a full or limited extent. In Phase I of the comparison, a suite of 11 samples were measured. The suite of samples contained both synthetic `standard type` materials (i.e., AgI) and environmental materials. The isotopic 129I/127I ratios of the samples varied from 10`-8 to 10`-14. In this phase, each laboratory was responsible for its own chemical preparation of the environmental samples. The 129I AMS measurements obtained at different laboratories for prepared AgI were in good agreement. However, large discrepancies were seen in 129I AMS measurements of environmental samples. Because of the large discrepancies seen in the Phase I intercomparison, a subsequent study was conducted. In Phase II of the comparison, AgI was prepared from two environmental samples (IAEA 375 soil and maples leaves) by three separate laboratories. Each laboratory used its own chemical preparation method with each of the methods being distinctly different. The resulting six samples (two sets of three) were then redistributed to the participating 129I AMS facilities and 129I/127I ratios measured. Results and discussion of both the Phase I and Phase II interlaboratory comparison are presented.

  7. Large displacement spherical joint

    DOEpatents

    Bieg, Lothar F.; Benavides, Gilbert L.

    2002-01-01

    A new class of spherical joints has a very large accessible full cone angle, a property which is beneficial for a wide range of applications. Despite the large cone angles, these joints move freely without singularities.

  8. Stability and support issues in the construction of large span caverns for physics

    SciTech Connect

    Laughton, C.; /Fermilab

    2008-05-01

    New physics experiments, proposed to study neutrinos and protons, call for the use of large underground particle detectors. In the United States, such detectors would be housed in the US Deep Underground Science and Engineering Laboratory (DUSEL), sited within the footprint of the defunct Homestake Mine, South Dakota. Although the experimental proposals differ in detail, all rely heavily upon the ability of the mined and reinforced rock mass to serve as a stable host for the detector facilities. Experimental proposals, based on the use of Water Cherenkov detector technology, specify rock caverns with excavated volumes in excess of half a million cubic meters, spans of at least 50 m, sited at depths of approximately one to 1.5 kilometers. Although perhaps sited at shallower depth, proposals based on the use of Liquid Argon (LAr) detector technology are no less challenging. LAr proposals not only call for the excavation of large span caverns, but have an additional need for the safe management of large quantities (kilo-tonnes) of cryogenic liquid, including critical provisions for the fail-safe egress of underground personnel and the reliable exhaust of Argon gas in the event of a catastrophic release. These multi-year, high value physics experiments will provide the key experimental data needed to support the research of a new generation of physicists as they probe the behavior of basic particles and the fundamental laws of nature. The rock engineer must deliver caverns that will reliably meet operational requirements and remain stable for periods conservatively estimated to be in excess of twenty years. This paper provides an overview of the DUSEL site conditions and discusses key end-user requirements and design criteria likely to dominate in determining the viability of experimental options. The paper stresses the paramount importance of collecting adequate site-specific data to inform early siting, dimensioning and layout decisions. Given the large-scale of the

  9. Active phase locking of thirty fiber channels using multilevel phase dithering method.

    PubMed

    Huang, Zhimeng; Tang, Xuan; Luo, Yongquan; Liu, Cangli; Li, Jianfeng; Zhang, Dayong; Wang, Xiaojun; Chen, Tunan; Han, Mei

    2016-03-01

    An active phase locking of a large-scale fiber array with thirty channels has been demonstrated experimentally. In the experiment, the first group of thirty phase controllers is used to compensate the phase noises between the elements and the second group of thirty phase modulators is used to impose additional phase disturbances to mimic the phase noises in the high power fiber amplifiers. A multi-level phase dithering algorithm using dual-level rectangular-wave phase modulation and time division multiplexing can achieve the same phase control as single/multi-frequency dithering technique, but without coherent demodulation circuit. The phase locking efficiency of 30 fiber channels is achieved about 98.68%, 97.82%, and 96.50% with no additional phase distortion, modulated phase distortion I (±1 rad), and phase distortion II (±2 rad), corresponding to the phase error of λ/54, λ/43, and λ/34 rms. The contrast of the coherent combined beam profile is about 89%. Experimental results reveal that the multi-level phase dithering technique has great potential in scaling to a large number of laser beams. PMID:27036760

  10. Properties and behavior of superconductors exhibiting a Fulde-Ferrell-Larkin-Ovchinnikov phase

    NASA Astrophysics Data System (ADS)

    Coniglio, William A.; Agosta, Charles C.

    2011-03-01

    The body of data on the Ful-de--Fer-rell--Lar-kin--Ov-chin-ni-kov (FFLO) state in 2d organic superconductors has grown to a critical mass where we may begin studying the boundaries of the FFLO phase in detail. In some very clean layered superconductors, when a magnetic field is aligned exactly parallel to the conducting layers, a superconducting phase develops at fields above the Pauli paramagnetic limit Hp and temperatures below about Tc / 3 . The phase is widely ascribed to FFLO behavior. We focus on the superconductors κ -(ET)2 Cu(NCS)2 , β'' -(ET)2 SF5 CH2 CF2 SO3 , and λ -(BETS)2 GaCl 4 , which have been studied by rf penetration depth and other techniques. We have probed the boundaries of the FFLO phase using alignment angle to tune the amount of spin-orbit scattering and temperature to control the degree of Pauli paramagnetic limiting. Using our data collected in pulsed magnetic fields at low temperature, we have gained new understanding about the behavior of the state and the conditions necessary for it to develop. We acknowledge Department of Energy support from ER46214.

  11. Lars Onsager Prize: The mean field solution for Hard Sphere Jamming and a new scenario for the low temperature landscape of glasses

    NASA Astrophysics Data System (ADS)

    Parisi, Giorgio

    In a hard spheres systems particles cannot overlap. Increasing the density we reach a point where most of the particles are blocked and the density cannot be increased any more: this is the jamming point. The jamming point separates the phase, where all the constraint can be satisfied, from an unsatifiable phase, where spheres do have to overlap. A scaling theory of the behavior around the jamming critical point has been formulated and a few critical exponents have been introduced. The exponents are apparently super-universal, as far as they do seem to be independent from the space dimensions. The mean field version of the model (i.e. the infinite dimensions limit) has been solved analytically using broken replica symmetry techniques and the computed critical exponents have been found in a remarkable agreement with three-dimensional and two-dimensional numerical results and experiments. The theory predicts in hard spheres (in glasses) a new transition (the Gardener transition) from the replica symmetric phase to the replica broken phase at high density (at low temperature), in agreement with simulations on hard sphere systems. I will briefly discuss the possible consequences of this new picture on the very low temperature behavior of glasses in the quantum regime.

  12. Muon-induced background to proton decay in the p →K+ ν decay channel with large underground liquid argon TPC detectors

    NASA Astrophysics Data System (ADS)

    Klinger, J.; Kudryavtsev, V. A.; Richardson, M.; Spooner, N. J. C.

    2015-06-01

    Large liquid argon TPC detector programs such as LBNE and LAGUNA-LBNO will be able to make measurements of the proton lifetime which will outperform Cherenkov detectors in the proton decay channel p →K+ ν. At the large depths which are proposed for such experiments, a non-negligible source of isolated charged kaons may be produced in the showers of cosmogenic muons. We present an estimate of the cosmogenic muon background to proton decay in the p →K+ ν channel. The simulation of muon transport to a depth of 4 km w.e. is performed in the MUSIC framework and the subsequent propagation of muons and secondary particles in the vicinity of a cylindrical 20 kt LAr target is performed using GEANT4. An exposure time of 100 years is considered, with a rate of <0.0012 events/kt/year at 90% CL predicted from our simulations.

  13. Linearity optimization in a class of analog phase modulators

    NASA Technical Reports Server (NTRS)

    Hearn, C. P.

    1985-01-01

    This paper examines the ultimate modulating linearity attainable with a phase modulation technique based on the linear addition of quadrature phase carrier signals which have been multiplied by precisely defined nonlinear transformations of the modulating signal. Optimum gain coefficients are derived and plotted to permit implementation of analog phase modulators capable of exceptionally good linearity of phase deviations as large as 5 radians.

  14. Large mode radius resonators

    NASA Technical Reports Server (NTRS)

    Harris, Michael R.

    1987-01-01

    Resonator configurations permitting operation with large mode radius while maintaining good transverse mode discrimination are considered. Stable resonators incorporating an intracavity telescope and unstable resonator geometries utilizing an output coupler with a Gaussian reflectivity profile are shown to enable large radius single mode laser operation. Results of heterodyne studies of pulsed CO2 lasers with large (11mm e sup-2 radius) fundamental mode sizes are presented demonstrating minimal frequency sweeping in accordance with the theory of laser-induced medium perturbations.

  15. Slug flow in a large diameter pipe

    SciTech Connect

    Crowley, C.J.; Sam, R.G.; Wallis, G.B.; Mehta, D.C.

    1985-01-01

    Experimental and anlytical results are presented for two-phase slug flow in a transparent, large diameter pipe (6.75 inches ID) at high gas density. Slug characteristics of velocity, length, frequency, carpet profile and carpet velocity, as well as pressure drop, have been measured and compared with correlations and mechanistic models.

  16. Computerized Torque Control for Large dc Motors

    NASA Technical Reports Server (NTRS)

    Willett, Richard M.; Carroll, Michael J.; Geiger, Ronald V.

    1987-01-01

    Speed and torque ranges in generator mode extended. System of shunt resistors, electronic switches, and pulse-width modulation controls torque exerted by large, three-phase, electronically commutated dc motor. Particularly useful for motor operating in generator mode because it extends operating range to low torque and high speed.

  17. Deflectometric measurement of large mirrors

    NASA Astrophysics Data System (ADS)

    Olesch, Evelyn; Häusler, Gerd; Wörnlein, André; Stinzing, Friedrich; van Eldik, Christopher

    2014-06-01

    We discuss the inspection of large-sized, spherical mirror tiles by `Phase Measuring Deflectometry' (PMD). About 10 000 of such mirror tiles, each satisfying strict requirements regarding the spatial extent of the point-spread-function (PSF), are planned to be installed on the Cherenkov Telescope Array (CTA), a future ground-based instrument to observe the sky in very high energy gamma-rays. Owing to their large radii of curvature of up to 60 m, a direct PSF measurement of these mirrors with concentric geometry requires large space. We present a PMD sensor with a footprint of only 5×2×1.2 m3 that overcomes this limitation. The sensor intrinsically acquires the surface slope; the shape data are calculated by integration. In this way, the PSF can be calculated for real case scenarios, e.g., when the light source is close to infinity and off-axis. The major challenge is the calibration of the PMD sensor, specifically because the PSF data have to be reconstructed from different camera views. The calibration of the setup is described, and measurements presented and compared to results obtained with the direct approach.

  18. Magnetic Phases in Dense Quark Matter

    SciTech Connect

    Incera, Vivian de la

    2007-10-26

    In this paper I discuss the magnetic phases of the three-flavor color superconductor. These phases can take place at different field strengths in a highly dense quark system. Given that the best natural candidates for the realization of color superconductivity are the extremely dense cores of neutron stars, which typically have very large magnetic fields, the magnetic phases here discussed could have implications for the physics of these compact objects.

  19. On-sky multiwavelength phasing of segmented telescopes with the Zernike phase contrast sensor.

    PubMed

    Vigan, Arthur; Dohlen, Kjetil; Mazzanti, Silvio

    2011-06-10

    Future extremely large telescopes will adopt segmented primary mirrors with several hundreds of segments. Cophasing of the segments together is essential to reach high wavefront quality. The phasing sensor must be able to maintain very high phasing accuracy during the observations, while being able to phase segments dephased by several micrometers. The Zernike phase contrast sensor has been demonstrated on-sky at the Very Large Telescope. We present the multiwavelength scheme that has been implemented to extend the capture range from ±λ/2 on the wavefront to many micrometers, demonstrating that it is successful at phasing mirrors with piston errors up to ±4.0  μm on the wavefront. We discuss the results at different levels and conclude with a phasing strategy for a future extremely large telescope.

  20. On the structure of supercritical phase transition

    SciTech Connect

    Hirata, Y.S. )

    1990-06-10

    A novel physical picture is presented for the normal-to-supercritical phase transition in QED around a large-Z nucleus. The process is described as the decay of the false vacuum in close analogy to the first-order phase transition in statistical mechanics. The irreversible nature of the transition is pointed out and the physical implications of this picture are discussed.

  1. Multi-pore carbon phase plate for phase-contrast transmission electron microscopy.

    PubMed

    Sannomiya, Takumi; Junesch, Juliane; Hosokawa, Fumio; Nagayama, Kuniaki; Arai, Yoshihiro; Kayama, Yoko

    2014-11-01

    A new fabrication method of carbon based phase plates for phase-contrast transmission electron microscopy is presented. This method utilizes colloidal masks to produce pores as well as disks on thin carbon membranes for phase modulation. Since no serial process is involved, carbon phase plate membranes containing hundreds of pores can be mass-produced on a large scale, which allows "disposal" of contaminated or degraded phase modulating objects after use. Due to the spherical shape of the mask colloid particles, the produced pores are perfectly circular. The pore size and distribution can be easily tuned by the mask colloid size and deposition condition. By using the stencil method, disk type phase plates can also be fabricated on a pore type phase plate. Both pore and disk type phase plates were tested by measuring amorphous samples and confirmed to convert the sinus phase contrast transfer function to the cosine shape. PMID:25129640

  2. Large wind turbine generators

    NASA Technical Reports Server (NTRS)

    Thomas, R. L.; Donovon, R. M.

    1978-01-01

    The development associated with large wind turbine systems is briefly described. The scope of this activity includes the development of several large wind turbines ranging in size from 100 kW to several megawatt levels. A description of the wind turbine systems, their programmatic status and a summary of their potential costs is included.

  3. Large Print Bibliography, 1990.

    ERIC Educational Resources Information Center

    South Dakota State Library, Pierre.

    This bibliography lists materials that are available in large print format from the South Dakota State Library. The annotated entries are printed in large print and include the title of the material and its author, call number, publication date, and type of story or subject area covered. Some recorded items are included in the list. The entries…

  4. LARGE BUILDING RADON MANUAL

    EPA Science Inventory

    The report summarizes information on how bilding systems -- especially the heating, ventilating, and air-conditioning (HVAC) system -- inclurence radon entry into large buildings and can be used to mitigate radon problems. It addresses the fundamentals of large building HVAC syst...

  5. Phase unwrapping using discontinuity optimization

    SciTech Connect

    Flynn, T.J.

    1998-03-01

    In SAR interferometry, the periodicity of the phase must be removed using two-dimensional phase unwrapping. The goal of the procedure is to find a smooth surface in which large spatial phase differences, called discontinuities, are restricted to places where their presence is reasonable. The pioneering work of Goldstein et al. identified points of local unwrap inconsistency called residues, which must be connected by discontinuities. This paper presents an overview of recent work that treats phase unwrapping as a discrete optimization problem with the constraint that residues must be connected. Several algorithms use heuristic methods to reduce the total number of discontinuities. Constantini has introduced the weighted sum of discontinuity magnitudes as a criterion of unwrap error and shown how algorithms from optimization theory are used to minimize it. Pixels of low quality are given low weight to guide discontinuities away from smooth, high-quality regions. This method is generally robust, but if noise is severe it underestimates the steepness of slopes and the heights of peaks. This problem is mitigated by subtracting (modulo 2{pi}) a smooth estimate of the unwrapped phase from the data, then unwrapping the resulting residual phase. The unwrapped residual is added to the smooth estimate to produce the final unwrapped phase. The estimate can be computed by lowpass filtering of an existing unwrapped phase; this makes possible an iterative algorithm in which the result of each iteration provides the estimate for the next. An example illustrates the results of optimal discontinuity placement and the improvement from unwrapping of the residual phase.

  6. New View of the QCD Phase Diagram

    SciTech Connect

    McLerran,L.

    2009-07-09

    Quarkyonic matter is confining but can have densities much larger than 3QCD. Its existence isargued in the large Nc limit of QCD and implies that there are at least three phases of QCD with greatly different bulk properties. These are a Confined Phase of hadrons, a Deconfined Phase ofquarks and gluons, and the Quarkyonic Phase. In the Quarkyonic Phase, the baryon density isaccounted for by a quasi-free gas of quarks, and the the antiquarks and gluons are confined intomesons, glueballs. Quarks near the Fermi surface also are treated as baryons. (In addition tothese phases, there is a color superconducting phase that has vastly different transport properties than the above, but with bulk properties, such as pressure and energy density, that are not greatlydifferent than that of Quarkyonic Matter.)

  7. The large hadron collider

    NASA Astrophysics Data System (ADS)

    Brüning, O.; Burkhardt, H.; Myers, S.

    2012-07-01

    The Large Hadron Collider (LHC) is the world’s largest and most energetic particle collider. It took many years to plan and build this large complex machine which promises exciting, new physics results for many years to come. We describe and review the machine design and parameters, with emphasis on subjects like luminosity and beam conditions which are relevant for the large community of physicists involved in the experiments at the LHC. First collisions in the LHC were achieved at the end of 2009 and followed by a period of a rapid performance increase. We discuss what has been learned so far and what can be expected for the future.

  8. Phase Coexistence in a Dynamic Phase Diagram.

    PubMed

    Gentile, Luigi; Coppola, Luigi; Balog, Sandor; Mortensen, Kell; Ranieri, Giuseppe A; Olsson, Ulf

    2015-08-01

    Metastability and phase coexistence are important concepts in colloidal science. Typically, the phase diagram of colloidal systems is considered at the equilibrium without the presence of an external field. However, several studies have reported phase transition under mechanical deformation. The reason behind phase coexistence under shear flow is not fully understood. Here, multilamellar vesicle (MLV)-to-sponge (L3 ) and MLV-to-Lα transitions upon increasing temperature are detected using flow small-angle neutron scattering techniques. Coexistence of Lα and MLV phases at 40 °C under shear flow is detected by using flow NMR spectroscopy. The unusual rheological behavior observed by studying the lamellar phase of a non-ionic surfactant is explained using (2) H NMR and diffusion flow NMR spectroscopy with the coexistence of planar lamellar-multilamellar vesicles. Moreover, a dynamic phase diagram over a wide range of temperatures is proposed.

  9. Learning with Large Blocks.

    ERIC Educational Resources Information Center

    Cartwright, Sally

    1990-01-01

    Discusses how large hollow blocks can meet many preschool children's learning needs through creative dramatic play, and also gives some guidelines on how these blocks can be constructed by parents and teachers. (BB)

  10. Closed Large Cell Clouds

    Atmospheric Science Data Center

    2013-04-19

    article title:  Closed Large Cell Clouds in the South Pacific     ... unperturbed by cyclonic or frontal activity. When the cell centers are cloudy and the main sinking motion is concentrated at cell ...

  11. Large scale dynamic systems

    NASA Technical Reports Server (NTRS)

    Doolin, B. F.

    1975-01-01

    Classes of large scale dynamic systems were discussed in the context of modern control theory. Specific examples discussed were in the technical fields of aeronautics, water resources and electric power.

  12. Large intestine (colon) (image)

    MedlinePlus

    ... portion of the digestive system most responsible for absorption of water from the indigestible residue of food. The ileocecal valve of the ileum (small intestine) passes material into the large intestine at the ...

  13. Large Customers (DR Sellers)

    SciTech Connect

    Kiliccot, Sila

    2011-10-25

    State of the large customers for demand response integration of solar and wind into electric grid; openADR; CAISO; DR as a pseudo generation; commercial and industrial DR strategies; California regulations

  14. Large wood recruitment and transport during large floods: A review

    NASA Astrophysics Data System (ADS)

    Comiti, F.; Lucía, A.; Rickenmann, D.

    2016-09-01

    Large wood (LW) elements transported during large floods are long known to have the capacity to induce dangerous obstructions along the channel network, mostly at bridges and at hydraulic structures such as weirs. However, our current knowledge of wood transport dynamics during high-magnitude flood events is still very scarce, mostly because these are (locally) rare and thus unlikely to be directly monitored. Therefore, post-event surveys are invaluable ways to get insights (although indirectly) on LW recruitment processes, transport distance, and factors inducing LW deposition - all aspects that are crucial for the proper management of river basins related to flood hazard mitigation. This paper presents a review of the (quite limited) literature available on LW transport during large floods, drawing extensively on the authors' own experience in mountain and piedmont rivers, published and unpublished. The overall picture emerging from these studies points to a high, catchment-specific variability in all the different processes affecting LW dynamics during floods. Specifically, in the LW recruitment phase, the relative floodplain (bank erosion) vs. hillslope (landslide and debris flows) contribution in mountain rivers varies substantially, as it relates to the extent of channel widening (which depends on many variables itself) but also to the hillslope-channel connectivity of LW mobilized on the slopes. As to the LW transport phase within the channel network, it appears to be widely characterized by supply-limited conditions; whereby LW transport rates (and thus volumes) are ultimately constrained by the amount of LW that is made available to the flow. Indeed, LW deposition during floods was mostly (in terms of volume) observed at artificial structures (bridges) in all the documented events. This implies that the estimation of LW recruitment and the assessment of clogging probabilities for each structure (for a flood event of given magnitude) are the most important

  15. Phased Array Feeds

    NASA Astrophysics Data System (ADS)

    Fisher, J. Richard; Bradley, Richard F.; Brisken, Walter F.; Cotton, William D.; Emerson, Darrel T.; Kerr, Anthony R.; Lacasse, Richard J.; Morgan, Matthew A.; Napier, Peter J.; Norrod, Roger D.; Payne, John M.; Pospieszalski, Marian W.; Symmes, Arthur; Thompson, A. Richard; Webber, John C.

    This white paper offers cautionary observations about the planning and development of new, large radio astronomy instruments. Complexity is a strong cost driver so every effort should be made to assign differing science requirements to different instruments and probably different sites. The appeal of shared resources is generally not realized in practice and can often be counterproductive. Instrument optimization is much more difficult with longer lists of requirements, and the development process is longer and less efficient. More complex instruments are necessarily further behind the technology state of the art because of longer development times. Including technology R&D in the construction phase of projects is a growing trend that leads to higher risks, cost overruns, schedule delays, and project de-scoping. There are no technology breakthroughs just over the horizon that will suddenly bring down the cost of collecting area. Advances come largely through careful attention to detail in the adoption of new technology provided by industry and the commercial market. Radio astronomy instrumentation has a very bright future, but a vigorous long-term R&D program not tied directly to specific projects needs to be restored, fostered, and preserved.

  16. CrowdPhase: crowdsourcing the phase problem

    SciTech Connect

    Jorda, Julien; Sawaya, Michael R.; Yeates, Todd O.

    2014-06-01

    The idea of attacking the phase problem by crowdsourcing is introduced. Using an interactive, multi-player, web-based system, participants work simultaneously to select phase sets that correspond to better electron-density maps in order to solve low-resolution phasing problems. The human mind innately excels at some complex tasks that are difficult to solve using computers alone. For complex problems amenable to parallelization, strategies can be developed to exploit human intelligence in a collective form: such approaches are sometimes referred to as ‘crowdsourcing’. Here, a first attempt at a crowdsourced approach for low-resolution ab initio phasing in macromolecular crystallography is proposed. A collaborative online game named CrowdPhase was designed, which relies on a human-powered genetic algorithm, where players control the selection mechanism during the evolutionary process. The algorithm starts from a population of ‘individuals’, each with a random genetic makeup, in this case a map prepared from a random set of phases, and tries to cause the population to evolve towards individuals with better phases based on Darwinian survival of the fittest. Players apply their pattern-recognition capabilities to evaluate the electron-density maps generated from these sets of phases and to select the fittest individuals. A user-friendly interface, a training stage and a competitive scoring system foster a network of well trained players who can guide the genetic algorithm towards better solutions from generation to generation via gameplay. CrowdPhase was applied to two synthetic low-resolution phasing puzzles and it was shown that players could successfully obtain phase sets in the 30° phase error range and corresponding molecular envelopes showing agreement with the low-resolution models. The successful preliminary studies suggest that with further development the crowdsourcing approach could fill a gap in current crystallographic methods by making it

  17. Optically-controlled coplanar waveguide phase shifters

    NASA Astrophysics Data System (ADS)

    Neikirk, Dean P.; Cheung, Philip; Islam, M. Saiful; Itoh, Tatsuo

    1989-12-01

    This paper discusses the principles of optically-controlled phase shifters, with particular attention given to the design tradeoffs associated with optically-controlled coplanar waveguide (CPW) phase shifters. Experimental results from several different structures are presented. It is concluded that the coplanar waveguide transmission lines on semiconductor substrates, while structurally suited for optical control of the slow wave factor, might not be practical for MMIC applications, because they require very high optical illumination intensities to produce useful phase shifts. However, by combining a reverse-biased, Schottky barrier-contacted CPW with controlled optical illumination, large phase shifts at very low intensities can be achieved.

  18. Susceptibility of large populations of coupled oscillators.

    PubMed

    Daido, Hiroaki

    2015-01-01

    It is an important and interesting problem to elucidate how the degree of phase order in a large population of coupled oscillators responds to a synchronizing periodic force from the outside. Here this problem is studied analytically as well as numerically by introducing the concept of susceptibility for globally coupled phase oscillators with either nonrandom or random interactions. It is shown that the susceptibility diverges at the critical point in the nonrandom case with Widom's equality satisfied, while it exhibits a cusp in the most random case.

  19. Large electrostatic accelerators

    SciTech Connect

    Jones, C.M.

    1984-01-01

    The increasing importance of energetic heavy ion beams in the study of atomic physics, nuclear physics, and materials science has partially or wholly motivated the construction of a new generation of large electrostatic accelerators designed to operate at terminal potentials of 20 MV or above. In this paper, the author briefly discusses the status of these new accelerators and also discusses several recent technological advances which may be expected to further improve their performance. The paper is divided into four parts: (1) a discussion of the motivation for the construction of large electrostatic accelerators, (2) a description and discussion of several large electrostatic accelerators which have been recently completed or are under construction, (3) a description of several recent innovations which may be expected to improve the performance of large electrostatic accelerators in the future, and (4) a description of an innovative new large electrostatic accelerator whose construction is scheduled to begin next year. Due to time and space constraints, discussion is restricted to consideration of only tandem accelerators.

  20. Large pore alumina

    SciTech Connect

    Ternan, M. )

    1994-04-01

    Earlier the authors reported preparation conditions for an alumina material which contained large diameter macropores (0.1-100 [mu]). The preparation variable that caused the formation of the uncommonly large macropores was the large acid/alumina ratios which were very much greater than the ones used in the preparation of conventional porous aluminas. The alumina material had large BET surface areas (200 m[sup 2]/g) and small mercury porosimetry surface areas (1 m[sup 2]/g). This indicated that micropores (d[sub MIP]<2 nm) were present in the alumina, since they were large enough for nitrogen gas molecules to enter, but too small for mercury to enter. As a result they would be too small for significant diffusion rates of residuum molecules. In earlier work, the calcining temperature was fixed at 500[degrees]C. In the current work, variations in both calcining temperature and calcining time were used in an attempt to convert some of the micropores into mesopores. 12 refs., 2 figs., 1 tab.

  1. A large liquid argon time projection chamber for long-baseline, off-axis neutrino oscillation physics with the NuMI beam

    SciTech Connect

    Finley, D.; Jensen, D.; Jostlein, H.; Marchionni, A.; Pordes, S.; Rapidis, P.A.; Bromberg, C.; Lu, C.; McDonald, T.; Gallagher, H.; Mann, A.; Schneps, J.; Cline, D.; Sergiampietri, F.; Wang, H.; Curioni, A.; Fleming, B.T.; Menary, S.; /York U., Canada

    2005-09-01

    Results from neutrino oscillation experiments in the last ten years have revolutionized the field of neutrino physics. While the overall oscillation picture for three neutrinos is now well established and precision measurements of the oscillation parameters are underway, crucial issues remain. In particular, the hierarchy of the neutrino masses, the structure of the neutrino mixing matrix, and, above all, CP violation in the neutrino sector are the primary experimental challenges in upcoming years. A program that utilizes the newly commissioned NuMI neutrino beamline, and its planned upgrades, together with a high-performance, large-mass detector will be in an excellent position to provide decisive answers to these key neutrino physics questions. A Liquid Argon time projection chamber (LArTPC) [2], which combines fine-grained tracking, total absorption calorimetry, and scalability, is well matched for this physics program. The few-millimeter-scale spatial granularity of a LArTPC combined with dE/dx measurements make it a powerful detector for neutrino oscillation physics. Scans of simulated event samples, both directed and blind, have shown that electron identification in {nu}{sub e} charged current interactions can be maintained at an efficiency of 80%. Backgrounds for {nu}{sub e} appearance searches from neutral current events with a {pi}{sup 0} are reduced well below the {approx} 0.5-1.0% {nu}{sub e} contamination of the {nu}{sub {mu}} beam [3]. While the ICARUS collaboration has pioneered this technology and shown its feasibility with successful operation of the T600 (600-ton) LArTPC [4], a detector for off-axis, long-baseline neutrino physics must be many times more massive to compensate for the low event rates. We have a baseline concept [5] based on the ICARUS wire plane structure and commercial methods of argon purification and housed in an industrial liquefied-natural-gas tank. Fifteen to fifty kton liquid argon capacity tanks have been considered. A very

  2. The Large Scale Synthesis of Aligned Plate Nanostructures

    PubMed Central

    Zhou, Yang; Nash, Philip; Liu, Tian; Zhao, Naiqin; Zhu, Shengli

    2016-01-01

    We propose a novel technique for the large-scale synthesis of aligned-plate nanostructures that are self-assembled and self-supporting. The synthesis technique involves developing nanoscale two-phase microstructures through discontinuous precipitation followed by selective etching to remove one of the phases. The method may be applied to any alloy system in which the discontinuous precipitation transformation goes to completion. The resulting structure may have many applications in catalysis, filtering and thermal management depending on the phase selection and added functionality through chemical reaction with the retained phase. The synthesis technique is demonstrated using the discontinuous precipitation of a γ′ phase, (Ni, Co)3Al, followed by selective dissolution of the γ matrix phase. The production of the nanostructure requires heat treatments on the order of minutes and can be performed on a large scale making this synthesis technique of great economic potential. PMID:27439672

  3. The Large Scale Synthesis of Aligned Plate Nanostructures

    NASA Astrophysics Data System (ADS)

    Zhou, Yang; Nash, Philip; Liu, Tian; Zhao, Naiqin; Zhu, Shengli

    2016-07-01

    We propose a novel technique for the large-scale synthesis of aligned-plate nanostructures that are self-assembled and self-supporting. The synthesis technique involves developing nanoscale two-phase microstructures through discontinuous precipitation followed by selective etching to remove one of the phases. The method may be applied to any alloy system in which the discontinuous precipitation transformation goes to completion. The resulting structure may have many applications in catalysis, filtering and thermal management depending on the phase selection and added functionality through chemical reaction with the retained phase. The synthesis technique is demonstrated using the discontinuous precipitation of a γ‧ phase, (Ni, Co)3Al, followed by selective dissolution of the γ matrix phase. The production of the nanostructure requires heat treatments on the order of minutes and can be performed on a large scale making this synthesis technique of great economic potential.

  4. Large TV display system

    NASA Technical Reports Server (NTRS)

    Liu, Hua-Kuang (Inventor)

    1986-01-01

    A relatively small and low cost system is provided for projecting a large and bright television image onto a screen. A miniature liquid crystal array is driven by video circuitry to produce a pattern of transparencies in the array corresponding to a television image. Light is directed against the rear surface of the array to illuminate it, while a projection lens lies in front of the array to project the image of the array onto a large screen. Grid lines in the liquid crystal array are eliminated by a spacial filter which comprises a negative of the Fourier transform of the grid.

  5. The Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Myers, Stephen

    The Large Hadron Collider (LHC) was first suggested (in a documented way) in 1983 [1] as a possible future hadron collider to be installed in the 27 km "LEP" tunnel. More than thirty years later the collider has been operated successfully with beam for three years with spectacular performance and has discovered the long-sought-after Higgs boson. The LHC is the world's largest and most energetic particle collider. It took many years to plan and build this large complex machine which promises exciting, new physics results for many years to come...

  6. Quantitative optical phase microscopy.

    PubMed

    Barty, A; Nugent, K A; Paganin, D; Roberts, A

    1998-06-01

    We present a new method for the extraction of quantitative phase data from microscopic phase samples by use of partially coherent illumination and an ordinary transmission microscope. The technique produces quantitative images of the phase profile of the sample without phase unwrapping. The technique is able to recover phase even in the presence of amplitude modulation, making it significantly more powerful than existing methods of phase microscopy. We demonstrate the technique by providing quantitatively correct phase images of well-characterized test samples and show that the results obtained for more-complex samples correlate with structures observed with Nomarski differential interference contrast techniques.

  7. An Open-Label, Multicenter, Phase 1/2 Study of E7438 (EZH2 Histone Methyl Transferase [HMT] Inhibitor) as a Single Agent in Subjects With Advanced Solid Tumors or With B-cell Lymphomas

    ClinicalTrials.gov

    2016-09-01

    B-cell Lymphomas (Phase 1); Advanced Solid Tumors (Phase 1); Diffuse Large B-cell Lymphoma (Phase 2); Follicular Lymphoma (Phase 2); Transformed Follicular Lymphoma; Primary Mediastinal Large B-Cell Lymphoma

  8. Phase IV of Drug Development.

    PubMed

    Suvarna, Viraj

    2010-04-01

    Not all Phase IV studies are post-marketing surveillance (PMS) studies but every PMS study is a phase IV study. Phase IV is also an important phase of drug development. In particular, the real world effectiveness of a drug as evaluated in an observational, non-interventional trial in a naturalistic setting which complements the efficacy data that emanates from a pre-marketing randomized controlled trial (RCT). No matter how many patients are studied pre-marketing in a controlled environment, the true safety profile of a drug is characterized only by continuing safety surveillance through a spontaneous adverse event monitoring system and a post-marketing surveillance/non-interventional study. Prevalent practice patterns can generate leads that could result in further evaluation of a new indication via the RCT route or even a signal that may necessitate regulatory action (change in labeling, risk management/minimization action plan). Disease registries are another option as are the large simple hybrid trials. Surveillance of spontaneously reported adverse events continues as long as a product is marketed. And so Phase IV in that sense never ends.

  9. Risks of Large Portfolios

    PubMed Central

    Fan, Jianqing; Liao, Yuan; Shi, Xiaofeng

    2014-01-01

    The risk of a large portfolio is often estimated by substituting a good estimator of the volatility matrix. However, the accuracy of such a risk estimator is largely unknown. We study factor-based risk estimators under a large amount of assets, and introduce a high-confidence level upper bound (H-CLUB) to assess the estimation. The H-CLUB is constructed using the confidence interval of risk estimators with either known or unknown factors. We derive the limiting distribution of the estimated risks in high dimensionality. We find that when the dimension is large, the factor-based risk estimators have the same asymptotic variance no matter whether the factors are known or not, which is slightly smaller than that of the sample covariance-based estimator. Numerically, H-CLUB outperforms the traditional crude bounds, and provides an insightful risk assessment. In addition, our simulated results quantify the relative error in the risk estimation, which is usually negligible using 3-month daily data. PMID:26195851

  10. LARGE BUILDING HVAC SIMULATION

    EPA Science Inventory

    The report discusses the monitoring and collection of data relating to indoor pressures and radon concentrations under several test conditions in a large school building in Bartow, Florida. The Florida Solar Energy Center (FSEC) used an integrated computational software, FSEC 3.0...

  11. Developing Large CAI Packages.

    ERIC Educational Resources Information Center

    Reed, Mary Jac M.; Smith, Lynn H.

    1983-01-01

    When developing large computer-assisted instructional (CAI) courseware packages, it is suggested that there be more attentive planning to the overall package design before actual lesson development is begun. This process has been simplified by modifying the systems approach used to develop single CAI lessons, followed by planning for the…

  12. Death Writ Large

    ERIC Educational Resources Information Center

    Kastenbaum, Robert

    2004-01-01

    Mainstream thanatology has devoted its efforts to improving the understanding, care, and social integration of people who are confronted with life-threatening illness or bereavement. This article suggests that it might now be time to expand the scope and mission to include large-scale death and death that occurs through complex and multi-domain…

  13. Teaching Large Evening Classes

    ERIC Educational Resources Information Center

    Wambuguh, Oscar

    2008-01-01

    High enrollments, conflicting student work schedules, and the sheer convenience of once-a-week classes are pushing many colleges to schedule evening courses. Held from 6 to 9 pm or 7 to 10 pm, these classes are typically packed, sometimes with more than 150 students in a large lecture theater. How can faculty effectively teach, control, or even…

  14. Novel large aperture EBCCD

    NASA Astrophysics Data System (ADS)

    Suzuki, Atsumu; Aoki, Shigeki; Haba, Junji; Sakuda, Makoto; Suyama, Motohiro

    2011-02-01

    A novel large aperture electron bombardment charge coupled device (EBCCD) has been developed. The diameter of its photocathode is 10 cm and it is the first EBCCD with such a large aperture. Its gain shows good linearity as a function of applied voltage up to -12 kV, where the gain is 2400. The spatial resolution was measured using ladder pattern charts. It is better than 2 line pairs/mm, which corresponds to 3.5 times the CCD pixel size. The spatial resolution was also measured with a copper foil pattern on a fluorescent screen irradiated with X-rays (14 and 18 keV) and a 60 keV gamma-ray from an americium source. The result was consistent with the measurement using ladder pattern charts. The output signal as a function of input light intensity shows better linearity than that of image intensifier tubes (IIT) as expected. We could detect cosmic rays passing through a scintillating fiber block and a plastic scintillator as a demonstration for a practical use in particle physics experiments. This kind of large aperture EBCCD can, for example, be used as an image sensor for a detector with a large number of readout channels and is expected to be additionally applied to other physics experiments.

  15. Large, Easily Deployable Structures

    NASA Technical Reports Server (NTRS)

    Agan, W. E.

    1983-01-01

    Study of concepts for large space structures will interest those designing scaffolding, radio towers, rescue equipment, and prefabricated shelters. Double-fold, double-cell module was selected for further design and for zero gravity testing. Concept is viable for deployment by humans outside space vehicle as well as by remotely operated manipulator.

  16. Estimating Large Numbers

    ERIC Educational Resources Information Center

    Landy, David; Silbert, Noah; Goldin, Aleah

    2013-01-01

    Despite their importance in public discourse, numbers in the range of 1 million to 1 trillion are notoriously difficult to understand. We examine magnitude estimation by adult Americans when placing large numbers on a number line and when qualitatively evaluating descriptions of imaginary geopolitical scenarios. Prior theoretical conceptions…

  17. Phase shifter for antenna beam steering

    NASA Astrophysics Data System (ADS)

    Jindal, Ravi; Razban, Tchanguiz

    2016-03-01

    Wide band Array Antenna operates in Ku-band (10.7-12.7 GHz) frequency composed of N×N radiating elements. This antenna aims at the reception of television satellite signals. The goal of this research is to provide better possibility of electronic beam control instead of manual or mechanical control, and design compact and low cost phase shifters to be inserted in the feeding network of this antenna. The electronic control of the phase shifter will allow the control of beam steering. The emphasis of this project will be done at the beginning on the design of a good phase shifter in Ku band. The aim of this research is to define, simulate, release and measure a continuous phase shifter. Better reflection loss, low transmission loss, low Cost of array antennas, large range of phase-shifter, phase flatness and bandwidth will be achieved by providing better gain.

  18. Phase diagram of a single lane roundabout

    NASA Astrophysics Data System (ADS)

    Echab, H.; Lakouari, N.; Ez-Zahraouy, H.; Benyoussef, A.

    2016-03-01

    Using the cellular automata model, we numerically study the traffic dynamic in a single lane roundabout system of four entry/exit points. The boundaries are controlled by the injecting rates α1, α2 and the extracting rate β. Both the system with and without Splitter Islands of width Lsp are considered. The phase diagram in the (α1 , β) space and its variation with the roundabout size, Pagg (i.e. the probability of aggressive entry), and Pexit (i.e. the probability of preferential exit) are constructed. The results show that the phase diagram in both cases consists of three phases: free flow, congested and jammed. However, as Lsp increases the free flow phase enlarges while the congested and jammed ones shrink. On the other hand, the short sized roundabout shows better performance in the free flow phase while the large one is more optimal in the congested phase. The density profiles are also investigated.

  19. Options Study - Phase II

    SciTech Connect

    R. Wigeland; T. Taiwo; M. Todosow; W. Halsey; J. Gehin

    2010-09-01

    identify any nuclear fuel cycle technology or option that may result in a significant beneficial impact to the issues as compared to the current U.S. approach of once-through use of nuclear fuel in LWRs or similar reactors followed by direct disposal of UNF. This approach was taken because incremental differences may be difficult to clearly identify and justify due to the large uncertainties that can be associated with the specific causes of the issues. Phase II of this Options Study continued the review of nuclear fuel cycle options that was initiated and documented during Phase I, concentrating on reviewing and summarizing the potential of integrated nuclear fuel cycles. However, based on the reviews of previous studies and available data, it was not always possible to clearly determine sufficiently large differences between the various fuel cycle and technology options for some of the issues or evaluation measures, for example, in cases where only incremental differences with respect to the issues might be achieved regardless of the fuel cycle option or technologies being considered, or where differences were insufficient to clearly rise above the uncertainties.

  20. Large Terrain Modeling and Visualization for Planets

    NASA Technical Reports Server (NTRS)

    Myint, Steven; Jain, Abhinandan; Cameron, Jonathan; Lim, Christopher

    2011-01-01

    Physics-based simulations are actively used in the design, testing, and operations phases of surface and near-surface planetary space missions. One of the challenges in realtime simulations is the ability to handle large multi-resolution terrain data sets within models as well as for visualization. In this paper, we describe special techniques that we have developed for visualization, paging, and data storage for dealing with these large data sets. The visualization technique uses a real-time GPU-based continuous level-of-detail technique that delivers multiple frames a second performance even for planetary scale terrain model sizes.