Science.gov

Sample records for aligned swcnts showed

  1. 246. View showing the curvilinear alignment of the parkway on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    246. View showing the curvilinear alignment of the parkway on a ridge. Looking northeast. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  2. Structure and Characterization of Vertically Aligned Single-Walled Carbon Nanotube Bundles

    DOE PAGES

    Márquez, Francisco; López, Vicente; Morant, Carmen; ...

    2010-01-01

    Arrmore » ays of vertically aligned single-walled carbon nanotube bundles, SWCNTs, have been synthesized by simple alcohol catalytic chemical vapor deposition process, carried out at 800°C. The formed SWCNTs are organized in small groups perpendicularly aligned and attached to the substrate. These small bundles show a constant diameter of ca. 30 nm and are formed by the adhesion of no more than twenty individual SWCNTs perfectly aligned along their length.« less

  3. 21. VIEW OF GRAND CANAL, SHOWING OLD ALIGNMENT, LOOKING WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. VIEW OF GRAND CANAL, SHOWING OLD ALIGNMENT, LOOKING WEST LOCATION UNKNOWN. THE WIDE DRY BED OF THE SALT RIVER SPANS THE BACKGROUND. Photographer: Mark Durben, April 1989 - Grand Canal, North side of Salt River, Tempe, Maricopa County, AZ

  4. Enviroment, from southwest, showing Castle Garden Bridge and alignment of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Enviroment, from southwest, showing Castle Garden Bridge and alignment of Township Road 343 over Bennetts Branch of Sinnemahoning Creek - Castle Garden Bridge, Township Route 343 over Bennetts Branch of Sinnemahoning Creek, Driftwood, Cameron County, PA

  5. 4. VIEW NORTHEAST WEST PORTAL, SHOWING FORMER TRACK ALIGNMENT AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW NORTHEAST- WEST PORTAL, SHOWING FORMER TRACK ALIGNMENT AND ADJACENT NJ TURNPIKE VIADUCT. - National Docks Branch Bridge N.D.2F, Spans former Central Railroad of New Jersey , west of New Jersey Turnpike, north of Communipaw Avenue near Johnson Avenue, Jersey City, Hudson County, NJ

  6. 22. VIEW OF GRAND CANAL, SHOWING OLD ALIGNMENT, LOOKING WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. VIEW OF GRAND CANAL, SHOWING OLD ALIGNMENT, LOOKING WEST FROM BELOW THE SETTLING BASIN (see HAER Photograph No. AZ-30-17, Crosscut Hydro Plant). Photographer: Mark Durben, April 1989 - Grand Canal, North side of Salt River, Tempe, Maricopa County, AZ

  7. 18. VIEW OF GRAND CANAL, SHOWING OLD ALIGNMENT BEFORE 1989 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. VIEW OF GRAND CANAL, SHOWING OLD ALIGNMENT BEFORE 1989 REALIGNMENT, LOOKING NORTH TOWARD RAILROAD CROSSING AND CROSSCUT STEAM PLANT LARGE WHITE BUILDING. THE CROSSCUT HYDRO PLANT IS HIDDEN BY TREES TO RIGHT OF STEAM PLANT. Photographer: Mark Durben, April 1989 - Grand Canal, North side of Salt River, Tempe, Maricopa County, AZ

  8. 20. VIEW OF GRAND CANAL, SHOWING OLD ALIGNMENT, LOOKING EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. VIEW OF GRAND CANAL, SHOWING OLD ALIGNMENT, LOOKING EAST FROM SOUTH BANK NEAR SETTLING BASIN (see HAER Photograph No. AZ-30-17, Crosscut Hydro Plant). THE LARGE FOREGROUND PIPE CARRIED WATER ACROSS THE CANAL FROM THE SETTLING BASIN TO THE CROSSCUT STEAM PLANT. Photographer: Mark Durben, April 1989 - Grand Canal, North side of Salt River, Tempe, Maricopa County, AZ

  9. 8. Detail, below platform, showing usuallysubmerged chains aligned in metal ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Detail, below platform, showing usually-submerged chains aligned in metal guides at low tide; view to east. - Charlestown Navy Yard, Marine Railway, Between Piers 2 & 3, on Charlestown Waterfront at west end of Navy Yard, Boston, Suffolk County, MA

  10. Self-formation of highly aligned metallic, semiconducting and single chiral single-walled carbon nanotubes assemblies via a crystal template method

    SciTech Connect

    Kawai, Hideki; Hasegawa, Kai; Yanagi, Kazuhiro; Oyane, Ayako; Naitoh, Yasuhisa

    2014-09-01

    The fabrication of an aligned array of single-walled carbon nanotubes (SWCNTs) with a single chiral state has been a significant challenge for SWCNT applications as well as for basic science research. Here, we developed a simple, unique technique to produce assemblies in which metallic, semiconducting, and single chiral state SWCNTs were densely and highly aligned. We utilized a crystal of surfactant as a template on which mono-dispersed SWCNTs in solution self-assembled. Micro-Raman measurements and scanning electron microscopy measurements clearly showed that the SWCNTs were highly and densely aligned parallel to the crystal axis, indicating that approximately 70% of the SWCNTs were within 7° of being parallel. Moreover, the assemblies exhibited good field effect transistor characteristics with an on/off ratio of 1.3 × 10{sup 5}.

  11. Biologically Inspired Purification and Dispersion of SWCNTs

    NASA Technical Reports Server (NTRS)

    Feeback, Daniel L.; Clarke, Mark S.; Nikolaev, Pavel

    2009-01-01

    A biologically inspired method has been developed for (1) separating single-wall carbon nanotubes (SWCNTs) from other materials (principally, amorphous carbon and metal catalysts) in raw production batches and (2) dispersing the SWCNTs as individual particles (in contradistinction to ropes and bundles) in suspension, as required for a number of applications. Prior methods of purification and dispersal of SWCNTs involve, variously, harsh physical processes (e.g., sonication) or harsh chemical processes (e.g., acid reflux). These processes do not completely remove the undesired materials and do not disperse bundles and ropes into individual suspended SWCNTs. Moreover, these processes cut long SWCNTs into shorter pieces, yielding typical nanotube lengths between 150 and 250 nm. In contrast, the present method does not involve harsh physical or chemical processes. The method involves the use of biologically derived dispersal agents (BDDAs) in an aqueous solution that is mechanically homogenized (but not sonicated) and centrifuged. The dense solid material remaining after centrifugation is resuspended by vortexing in distilled water, yielding an aqueous suspension of individual, separated SWCNTs having lengths from about 10 to about 15 microns.

  12. High performance transistors via aligned polyfluorene-sorted carbon nanotubes

    SciTech Connect

    Brady, Gerald J.; Joo, Yongho; Singha Roy, Susmit; Gopalan, Padma; Arnold, Michael S.

    2014-02-24

    We evaluate the performance of exceptionally electronic-type sorted, semiconducting, aligned single-walled carbon nanotubes (s-SWCNTs) in field effect transistors (FETs). High on-conductance and high on/off conductance modulation are simultaneously achieved at channel lengths which are both shorter and longer than individual s-SWCNTs. The s-SWCNTs are isolated from heterogeneous mixtures using a polyfluorene-derivative as a selective agent and aligned on substrates via dose-controlled, floating evaporative self-assembly at densities of ∼50 s-SWCNTs μm{sup −1}. At a channel length of 9 μm the s-SWCNTs percolate to span the FET channel, and the on/off ratio and charge transport mobility are 2.2 × 10{sup 7} and 46 cm{sup 2} V{sup −1} s{sup −1}, respectively. At a channel length of 400 nm, a large fraction of the s-SWCNTs directly span the channel, and the on-conductance per width is 61 μS μm{sup −1} and the on/off ratio is 4 × 10{sup 5}. These results are considerably better than previous solution-processed FETs, which have suffered from poor on/off ratio due to spurious metallic nanotubes that bridge the channel. 4071 individual and small bundles of s-SWCNTs are tested in 400 nm channel length FETs, and all show semiconducting behavior, demonstrating the high fidelity of polyfluorenes as selective agents and the promise of assembling s-SWCNTs from solution to create high performance semiconductor electronic devices.

  13. Covalently Functionalized SWCNTs as Tailored p-Type Dopants for Perovskite Solar Cells.

    PubMed

    Miletić, Tanja; Pavoni, Eleonora; Trifiletti, Vanira; Rizzo, Aurora; Listorti, Andrea; Colella, Silvia; Armaroli, Nicola; Bonifazi, Davide

    2016-10-04

    The covalent functionalization of (7,6)-enriched single-walled carbon nanotubes (SWCNTs) with oligophenylenevinylene (OPV) moieties terminating with a dimethylamino group is proposed as an efficient way to enhance the affinity of CNTs with spiro-MeOTAD in perovskite-based solar cells. The evidence of SWCNTs functionalization and the degree of OPV substitution on SWCNTs are established from TGA, XPS, TEM, and Raman techniques. Our tailored doping materials afford photovoltaic performances in line with conventional Li-doped spiro-MeOTAD, showing at the same time a significantly improved chemical stability of the perovskite component over time. Furthermore, the comparison of the photovoltaic performances with those obtained with nonfunctionalized SWCNTs suggest that the presence of the organic appends ensures highly reproducible PV performances. These results demonstrate the suitability of this functionalized SWCNT material as a valid doping agent for spiro-MeOTAD, representing a viable alternative to the conventional Li salt.

  14. Three novel electrochemical electrodes for the fabrication of conducting polymer/SWCNTs layered nanostructures and their thermoelectric performance

    NASA Astrophysics Data System (ADS)

    Shi, Hui; Liu, Congcong; Jiang, Qinglin; Xu, Jingkun; Lu, Baoyang; Jiang, Fengxing; Zhu, Zhengyou

    2015-06-01

    Single-walled carbon nanotubes (SWCNTs), PEDOT:PSS/SWCNTs, and SWCNTs/PEDOT:PSS nanofilms were used as working electrodes to electrodeposit polyaniline (PANI) in a mixed alcohol solution of isopropyl alcohol (IPA), boron trifluoride ethyl ether (BFEE), and polyethylene glycol (PEG). The thermoelectric (TE) performances of the resulting nanofilms were systematically investigated. SWCNTs/PEDOT:PSS/PANI nanofilms showed a relatively high electrical conductivity value of 232.0 S cm-1. The Seebeck coefficient was enhanced and exhibited the values of 33.8, 25.6, and 23.0 μV K-1 for the SWCNTs/PANI, PEDOT:PSS/SWCNTs/PANI, and SWCNTs/PEDOT:PSS/PANI films, respectively. The maximum power factor achieved was 12.3 μW m-1 K-2. This technique offers a facile and versatile approach to a class of layered nanostructures, and it may provide a general strategy for fabricating a new generation of conducting polymer/SWCNTs materials for further practical applications.

  15. SWCNTs induced autophagic cell death in human bronchial epithelial cells.

    PubMed

    Park, Eun-Jung; Zahari, Nur Elida M; Lee, Eun-Woo; Song, Jaewhan; Lee, Jae-Hyeok; Cho, Myung-Haing; Kim, Jae-Ho

    2014-04-01

    Carbon nanotubes are being actively introduced in electronics, computer science, aerospace, and other industries. Thus, the urgent need for toxicological studies on CNTs is mounting. In this study, we investigated the alterations in cellular response with morphological changes induced by single-walled carbon nanotubes (SWCNTs) in BEAS-2B cells, a human bronchial epithelial cell line. At 24h after exposure, SWCNTs rapidly decreased ATP production and cell viability as well a slight increase in the number of cells in the subG1 and G1 phases. In addition, SWCNTs increased the expression of superoxide dismutase (SOD)-1, but not SOD-2, and the number of cells generating ROS. The concentration of Cu and Zn ions also increased in a dose-dependent manner in cells exposed to SWCNTs. SWCNTs significantly enhanced the release of nitric oxide, interleukin (IL)-6, and IL-8 and up-regulated the expression of chemokine- and cytokine-related genes. Furthermore, the levels of autophagy-related genes, especially the DRAM1 gene, and the autophagosome formation-related proteins, were clearly up-regulated together with an increase of autophagosome-like vacuoles. Based on these results, we suggest that SWCNTs induce autophagic cell death through mitochondrial dysfunction and cytosolic damage in human bronchial epithelial cells.

  16. Enhanced cold wall CVD reactor growth of horizontally aligned single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Mu, Wei; Kwak, Eun-Hye; Chen, Bingan; Huang, Shirong; Edwards, Michael; Fu, Yifeng; Jeppson, Kjell; Teo, Kenneth; Jeong, Goo-Hwan; Liu, Johan

    2016-05-01

    HASynthesis of horizontally-aligned single-walled carbon nanotubes (HA-SWCNTs) by chemical vapor deposition (CVD) directly on quartz seems very promising for the fabrication of future nanoelectronic devices. In comparison to hot-wall CVD, synthesis of HA-SWCNTs in a cold-wall CVD chamber not only means shorter heating, cooling and growth periods, but also prevents contamination of the chamber. However, since most synthesis of HA-SWCNTs is performed in hot-wall reactors, adapting this well-established process to a cold-wall chamber becomes extremely crucial. Here, in order to transfer the CVD growth technology from a hot-wall to a cold-wall chamber, a systematic investigation has been conducted to determine the influence of process parameters on the HA-SWCNT's growth. For two reasons, the cold-wall CVD chamber was upgraded with a top heater to complement the bottom substrate heater; the first reason to maintain a more uniform temperature profile during HA-SWCNTs growth, and the second reason to preheat the precursor gas flow before projecting it onto the catalyst. Our results show that the addition of a top heater had a significant effect on the synthesis. Characterization of the CNTs shows that the average density of HA-SWCNTs is around 1 - 2 tubes/ μm with high growth quality as shown by Raman analysis. [Figure not available: see fulltext.

  17. Long-term follow-up of lung biodistribution and effect of instilled SWCNTs using multiscale imaging techniques

    NASA Astrophysics Data System (ADS)

    Faraj, Achraf Al; Bessaad, Amine; Cieslar, Katarzyna; Lacroix, Ghislaine; Canet-Soulas, Emmanuelle; Crémillieux, Yannick

    2010-04-01

    Due to their distinctive properties, single-walled carbon nanotubes (SWCNTs) are being more and more extensively used in nanotechnology, with prospects in nanomedicine. It would therefore appear essential to develop and apply appropriate imaging tools for detecting and evaluating their biological impacts with the prospect of medical applications or in the situation of accidental occupational exposure. It has been shown recently that raw SWCNTs with metallic impurities can be noninvasively detected in the lungs by hyperpolarized 3helium (HP-3He) MRI. Moreover raw and purified SWCNTs had no acute biological effect. The purpose of the present longitudinal study was to investigate long-term follow-up by imaging, as well as chronic lung effects. In a 3-month follow-up study, multiscale imaging techniques combining noninvasive HP-3He and proton (H) MRI to ex vivo light (histopathological analysis) and transmission electron microscopy (TEM) were used to assess the biodistribution and biological effects of intrapulmonary instilled raw SWCNTs. Specific in vivo detection of carbon nanotubes with MRI relied on their intrinsic metal impurities. MRI also has the ability to evaluate tissue inflammation by the follow-up of local changes in signal intensity. MRI and ex vivo microscopy techniques showed that granulomatous and inflammatory reactions were produced in a time and dose dependent manner by instilled raw SWCNTs.

  18. Polarization-selective alignment of a carbon nanotube film by using femtosecond laser ablation

    NASA Astrophysics Data System (ADS)

    Choi, S. B.; Byeon, C. C.; Park, D. J.; Jeong, M. S.

    2016-01-01

    We report on a considerable alignment of single-walled carbon nanotubes (SWCNTs) in randomly oriented bundles, by using a simple drop-and-dry method and irradiation with high-intensity femtosecond laser pulses. A remarkable third-harmonic generation was observed after irradiation with the laser pulses, whereas a narrow-band white-light continuum was generated in the as-prepared films. This observation, combined with scanning electron microscopy images, confirmed the high degree of alignment of the SWCNTs. In contrast to the pulsed irradiation of carbon soot, the powerdependent laser irradiation of a highly-purified SWCNT film show polarization-dependent ablation of individual nanotubes caused by polarization-dependent absorption. Raman spectroscopy results confirmed the presence of fractured nanotubes caused by the ablation processes. Polarizationresolved absorption spectroscopy results revealed that the aligned SWCNT film had potential usage in optical polarizers.

  19. Enrichment of large-diameter semiconducting SWCNTs by polyfluorene extraction for high network density thin film transistors

    NASA Astrophysics Data System (ADS)

    Ding, Jianfu; Li, Zhao; Lefebvre, Jacques; Cheng, Fuyong; Dubey, Girjesh; Zou, Shan; Finnie, Paul; Hrdina, Amy; Scoles, Ludmila; Lopinski, Gregory P.; Kingston, Christopher T.; Simard, Benoit; Malenfant, Patrick R. L.

    2014-01-01

    A systematic study on the use of 9,9-dialkylfluorene homopolymers (PFs) for large-diameter semiconducting (sc-) single-walled carbon nanotube (SWCNT) enrichment is the focus of this report. The enrichment is based on a simple three-step extraction process: (1) dispersion of as-produced SWCNTs in a PF solution; (2) centrifugation at a low speed to separate the enriched sc-tubes; (3) filtration to collect the enriched sc-SWCNTs and remove excess polymer. The effect of the extraction conditions on the purity and yield including molecular weight and alkyl side-chain length of the polymers, SWCNT concentration, and polymer/SWCNT ratio have been examined. It was observed that PFs with alkyl chain lengths of C10, C12, C14, and C18, all have an excellent capability to enrich laser-ablation sc-SWCNTs when their molecular weight is larger than ~10 000 Da. More detailed studies were therefore carried out with the C12 polymer, poly(9,9-di-n-dodecylfluorene), PFDD. It was found that a high polymer/SWCNT ratio leads to an enhanced yield but a reduced sc-purity. A ratio of 0.5-1.0 gives an excellent sc-purity and a yield of 5-10% in a single extraction as assessed by UV-vis-NIR absorption spectra. The yield can also be promoted by multiple extractions while maintaining high sc-purity. Mechanistic experiments involving time-lapse dispersion studies reveal that m-SWCNTs have a lower propensity to be dispersed, yielding a sc-SWCNT enriched material in the supernatant. Dispersion stability studies with partially enriched sc-SWCNT material further reveal that m-SWCNTs : PFDD complexes will re-aggregate faster than sc-SWCNTs : PFDD complexes, providing further sc-SWCNT enrichment. This result confirms that the enrichment was due to the much tighter bundles in raw materials and the more rapid bundling in dispersion of the m-SWCNTs. The sc-purity is also confirmed by Raman spectroscopy and photoluminescence excitation (PLE) mapping. The latter shows that the enriched sc-SWCNT sample has

  20. Supported Catalytic Growth of SWCNTs using the CVD Method

    NASA Astrophysics Data System (ADS)

    Aslam, Z.; Li, X.; Brydson, R.; Rand, B.; Falke, U.; Bleloch, A.

    2006-02-01

    The growth of carbon nanotubes (CNTs) from supported metal catalysts using the CVD method with CH4 as the carbon feedstock was investigated using SEM and TEM. Studies include the influence of the substrate structure, the metal catalyst content and other experimental parameters on the nature of the CNTs produced using calcined aluminium nitrate and delta-alumina nanoparticles (~13nm). The iron catalyst precursors are ferric sulphate and also iron oxide nanoparticles. Using an aberration corrected STEM and a FEGTEM BF imaging has been used to identify symmetries of tubes produced, as well as a TEM-STM tip to measure I-V curves of SWCNTs. It appears the optimum iron precursor and catalyst support for production of SWCNTs is either ferric sulphate or iron oxide nanoparticles supported on deltaalumina nanoparticles.

  1. Controlling exfoliation in order to minimize damage during dispersion of long SWCNTs for advanced composites

    PubMed Central

    Yoon, Howon; Yamashita, Motoi; Ata, Seisuke; Futaba, Don N.; Yamada, Takeo; Hata, Kenji

    2014-01-01

    We propose an approach to disperse long single-wall carbon nanotubes (SWCNTs) in a manner that is most suitable for the fabrication of high-performance composites. We compare three general classes of dispersion mechanisms, which encompass 11 different dispersion methods, and we have dispersed long SWCNTs, short multi-wall carbon nanotubes, and short SWCNTs in order to understand the most appropriate dispersion methods for the different types of CNTs. From this study, we have found that the turbulent flow methods, as represented by the Nanomizer and high-pressure jet mill methods, produced unique and superior dispersibility of long SWCNTs, which was advantageous for the fabrication of highly conductive composites. The results were interpreted to imply that the biaxial shearing force caused an exfoliation effect to disperse the long SWCNTs homogeneously while suppressing damage. A conceptual model was developed to explain this dispersion mechanism, which is important for future work on advanced CNT composites. PMID:24469607

  2. Amplified electrochemical sensor employing CuO/SWCNTs and 1-butyl-3-methylimidazolium hexafluorophosphate for selective analysis of sulfisoxazole in the presence of folic acid.

    PubMed

    Karimi-Maleh, Hassan; Amini, Fatemeh; Akbari, Ahmad; Shojaei, Moein

    2017-06-01

    In the present work, CuO nanoparticle decorated on single wall carbon nanotubes (CuO/SWCNTs) nanocomposite was successfully synthesized by chemical precipitation method and used for modification of carbon paste electrode (CPE) in the presence of 1-butyl-3-methylimidazolium hexafluorophosphate (1-B-3-MIHFP) liquid as binder. The novel voltammetric sensor was used as first electrochemical sensor for determination of sulfisoxazole (SFX). CuO/SWCNTs nanocomposite characterized by scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) methods. Voltammetric methods such as cyclic voltammetry, square wave voltammetry (SWV), electrochemical impedance spectroscopy (EIS) and chronoamperometry were performed to assess the electrochemical performance of CuO/SWCNTs/1-B-3-MIHFP/CPE towards SFX in aqueous solution. The voltammetric obtained data confirm the significant enhancement of oxidation current and reduction overvoltage for electro-oxidation of SFX at a surface of CuO/SWCNTs/1-B-3-MIHFP/CPE. The square wave voltammetric response shows the linear increment of oxidation signals with an increase in the concentration of SFX in the range of 0.08-650μM with limit of detection 0.04μM. Using CuO/SWCNTs/1-B-3-MIHFP/CPE the SFX and folic acid peaks are separated ca. 0.72 and 0.895V, respectively; hence SFX can be detected in the presence of folic acid. Finally, the CuO/SWCNTs/1-B-3-MIHFP/CPE was used as high sensitive tools for analysis of SFX and folic acid in real samples.

  3. Mediated Electron Transfer at Vertically Aligned Single-Walled Carbon Nanotube Electrodes During Detection of DNA Hybridization

    NASA Astrophysics Data System (ADS)

    Wallen, Rachel; Gokarn, Nirmal; Bercea, Priscila; Grzincic, Elissa; Bandyopadhyay, Krisanu

    2015-06-01

    Vertically aligned single-walled carbon nanotube (VASWCNT) assemblies are generated on cysteamine and 2-mercaptoethanol (2-ME)-functionalized gold surfaces through amide bond formation between carboxylic groups generated at the end of acid-shortened single-walled carbon nanotubes (SWCNTs) and amine groups present on the gold surfaces. Atomic force microscopy (AFM) imaging confirms the vertical alignment mode of SWCNT attachment through significant changes in surface roughness compared to bare gold surfaces and the lack of any horizontally aligned SWCNTs present. These SWCNT assemblies are further modified with an amine-terminated single-stranded probe-DNA. Subsequent hybridization of the surface-bound probe-DNA in the presence of complementary strands in solution is followed using impedance measurements in the presence of Fe(CN)6 3-/4- as the redox probe in solution, which show changes in the interfacial electrochemical properties, specifically the charge-transfer resistance, due to hybridization. In addition, hybridization of the probe-DNA is also compared when it is attached directly to the gold surfaces without any intermediary SWCNTs. Contrary to our expectations, impedance measurements show a decrease in charge-transfer resistance with time due to hybridization with 300 nM complementary DNA in solution with the probe-DNA attached to SWCNTs. In contrast, an increase in charge-transfer resistance is observed with time during hybridization when the probe-DNA is attached directly to the gold surfaces. The decrease in charge-transfer resistance during hybridization in the presence of VASWCNTs indicates an enhancement in the electron transfer process of the redox probe at the VASWCNT-modified electrode. The results suggest that VASWCNTs are acting as mediators of electron transfer, which facilitate the charge transfer of the redox probe at the electrode-solution interface.

  4. Comparing the removal of perchlorate when using single-walled carbon nanotubes (SWCNTs) or granular activated carbon: adsorption kinetics and thermodynamics.

    PubMed

    Lou, Jie C; Hsu, Yung S; Hsu, Kai L; Chou, Ming S; Han, Jia Y

    2014-01-01

    This study aims to remove perchlorate using single-walled carbon nanotubes (SWCNTs) or granular activated carbon (GAC). Dynamic and equilibrium adsorption experiments were performed to evaluate the thermodynamic behavior of perchlorate on SWCNTs and GAC. Key parameters affecting the adsorption, such as pH, ionic strength, and temperature were studied. The experimental results showed that the dynamic adsorption experiment achieved equilibrium in approximately eight hours. The adsorption capacity increased as the concentration of perchlorate increased or as the ionic strength decreased. The selected adsorption models were the modified Freundlich, the pseudo-1st-order, and the pseudo-2nd-order equations. The results showed that the modified Freundlich equation best described the kinetic adsorption processes. The maximal adsorption capacities of GAC and SWCNTs were 33.87-28.21 mg/g and 13.64 - 10.03 mg/g, respectively, at a constant temperature between 5°C and 45°C. The thermodynamic parameters, such as the equilibrium constant (K0 ), the standard free energy changes (ΔG°), the standard enthalpy change (ΔH°) and the standard entropy change (ΔS°), were obtained. The results of the isothermal equilibrium adsorption experiment showed that low pH levels, low ionic strength, and low-temperature conditions facilitated the perchlorate adsorption, indicating that GAC and SWCNTs are potential absorbents for water treatment.

  5. Characterizing Covalently Sidewall-Functionalized SWCNTs by using 1H NMR Spectroscopy

    PubMed Central

    Nelson, Donna J.; Kumar, Ravi

    2013-01-01

    Unambiguous evidence for covalent sidewall functionalization of single-walled carbon nanotubes (SWCNTs) has been a difficult task, especially for nanomaterials in which slight differences in functionality structure produce significant changes in molecular characteristics. Nuclear magnetic resonance (NMR) spectroscopy provides clear information about the structural skeleton of molecules attached to SWCNTs. In order to establish the generality of proton NMR as an analytical technique for characterizing covalently functionalized SWCNTs, we have obtained and analyzed proton NMR data of SWCNT-substituted benzenes across a variety of para substituents. Trends obtained for differences in proton NMR chemical shifts and the impact of o-, p-, and m-directing effects of electrophilic aromatic substituents on phenyl groups covalently bonded to SWCNTs are discussed. PMID:24009779

  6. Benchmark study of the length dependent thermal conductivity of individual suspended, pristine SWCNTs.

    PubMed

    Liu, Jinhui; Li, Tianyi; Hu, Yudong; Zhang, Xing

    2017-01-26

    The thermal conductivity of individual suspended single-walled carbon nanotubes (SWCNTs) has been theoretically predicated to increase with length but this has never been verified experimentally. This then leads to the question of whether the thermal conductivity saturates to a finite constant value in ultra-long SWCNTs. This paper reports on experimental measurements of the thermal conductivity of individual suspended SWCNTs as a function of the characteristic thermal transport length using the same individual suspended SWCNT sample. Interestingly, at around 360 K, the thermal conductivity first increases with increasing characteristic length and then saturates to a finite constant value at a characteristic length of ∼10 μm. These experimental results provide a fundamental understanding of the phonon transport characteristics in suspended, pristine SWCNTs.

  7. Macroscopic Ensembles of Aligned Carbon Nanotubes in Bubble Imprints Studied by Polarized Raman Microscopy

    DOE PAGES

    Ushiba, Shota; Hoyt, Jordan; Masui, Kyoko; ...

    2014-01-01

    We study the alignment of single-wall carbon nanotubes (SWCNTs) in bubble imprints through polarized Raman microscopy. A hemispherical bubble containing SWCNTs is pressed against a glass substrate, resulting in an imprint of the bubble membrane with a coffee ring on the substrate. We find that macroscopic ensembles of aligned SWCNTs are obtained in the imprints, in which there are three patterns of orientations: (i) azimuthal alignment on the coffee ring, (ii) radial alignment at the edge of the membrane, and (iii) random orientation at the center of the membrane. We also find that the alignment of SWCNTs in the imprintsmore » can be manipulated by spinning bubbles. The orientation of SWCNTs on the coffee ring is directed radially, which is orthogonal to the case of unspun bubbles. This approach enables one to align SWCNTs in large quantities and in a short time, potentially opening up a wide range of CNT-based electronic and optical applications.« less

  8. Single-walled carbon nanotubes (SWCNTs) induce vasodilation in isolated rat aortic rings.

    PubMed

    Gutiérrez-Hernández, J M; Ramirez-Lee, M A; Rosas-Hernandez, H; Salazar-García, S; Maldonado-Ortega, D A; González, F J; Gonzalez, C

    2015-06-01

    Single-walled carbon nanotubes (SWCNTs) are used in biological systems with impact in biomedicine in order to improve diagnostics and treatment of diseases. However, their effects upon the vascular system, are not fully understood. Endothelium and smooth muscle cells (SMC) communicate through release of vasoactive factors as nitric oxide (NO) to maintain vascular tone. The aim of this study was to evaluate the effect of SWCNTs on vascular tone using isolated rat aortic rings, which were exposed to SWCNTs (0.1, 1 and 10 μg/mL) in presence and absence of endothelium. SWCNTs induced vasodilation in both conditions, indicating that this effect was independent on endothelium; moreover that vasodilation was NO-independent, since its blockage with L-NAME did not modify the observed effect. Together, these results indicate that SWCNTs induce vasodilation in the macrovasculature, may be through a direct interaction with SMC rather than endothelium independent of NO production. Further investigation is required to fully understand the mechanisms of action and mediators involved in the signaling pathway induced by SWCNTs on the vascular system.

  9. Preparation and Properties of Nanocomposites from Pristine and Modified SWCNTs of Comparable Average Aspect Ratios

    NASA Technical Reports Server (NTRS)

    Smith, Joseph G.; Delozier, Donavon M.; Watson, Kent A.; Connell, John W.; Bekyarova, E.; Haddon, R.; Yu, A.

    2008-01-01

    Low color, flexible, space-durable polyimide films with inherent and robust electrical conductivity to dissipate electrostatic charge (ESC) have been under investigation as part of a materials development activity for future NASA space missions. The use of single-walled carbon nanotubes (SWCNTs) is one means to achieving this goal. Even though the concentration of SWCNTs needed to achieve ESC dissipation is typically low, it is dependent upon purity, size, dispersion, and functionalization. In this study, SWCNTs prepared by the electric arc discharge method were used to synthesize nanocomposites using the LaRC(TradeMark) CP2 backbone as the matrix. Pristine and functionalized SWCNTs were mixed with an alkoxysilane terminated amide acid of LaRC(TradeMark) CP2 and the soluble imide form of the polymer and the resultant nanocomposites evaluated for mechanical, thermal, and electrical properties. Due to the preparative conditions for the pristine and functionalized SWCNTs, the average aspect ratio for both was comparable. This permitted the assessment of SWCNT functionalization with respect to various interactions (e.g. van der Waals, hydrogen bonding, covalent bond formation, etc.) with the matrix and the macroscopic effects upon nanocomposite properties. The results of this study are described herein.

  10. Single-Walled Carbon Nanotubes (SWCNTs), as a Novel Sorbent for Determination of Mercury in Air

    PubMed Central

    Golbabaei, Farideh; Ebrahimi, Ali; Shirkhanloo, Hamid; Koohpaei, Alireza; Faghihi-Zarandi, Ali

    2016-01-01

    Background: Based on the noticeable toxicity and numerous application of mercury in industries, removal of mercury vapor through sorbent is an important environmental challenge. Purpose of the Study: Due to their highly porous and hollow structure, large specific surface area, light mass density and strong interaction, Single-Walled Carbon Nanotubes (SWCNTs) sorbent were selected for this investigation. Methods: In this study, instrumental conditions, method procedure and different effective parameters such as adsorption efficiency, desorption capacity, time, temperature and repeatability as well as retention time of adsorbed mercury were studied and optimized. Also, mercury vapor was determined by cold vapor atomic absorption spectrometry (CV-AAS). Obtained data were analyzed by Independent T- test, Multivariate linear regression and one way–ANOVA finally. Results: For 80 mg nanotubes, working range of SWCNT were achieved 0.02-0.7 μg with linear range (R2=0.994). Our data revealed that maximum absorption capacity was 0.5 μg g-1 as well as limit of detection (LOD) for studied sorbent was 0.006 μg. Also, optimum time and temperature were reported, 10 min and 250 °C respectively. Retention time of mercury on CNTs for three weeks was over 90%. Results of repeated trials indicated that the CNTs had long life, so that after 30 cycles of experiments, efficiency was determined without performance loss. Conclusion: Results showed that carbon nanotubes have high potential for efficient extraction of mercury from air and can be used for occupational and environmental purposes. The study of adsorption properties of CNTs is recommended. PMID:26925918

  11. The structure and continuous stoichiometry change of 1DTbBrx@SWCNTs.

    PubMed

    Kiselev, N A; Kumskov, A S; Zhigalina, V G; Vasiliev, A L; Sloan, J; Falaleev, N S; Verbitskiy, N I; Eliseev, A A

    2016-04-01

    HRTEM and HAADF STEM of 1DTbBrx@SWCNT meta-nanotubes reveal three structural modifications of 1D nanocrystals within single wall carbon nanotube channels attributed to a different stoichiometry of the guest crystal. For SWCNTs with diameters Dm > 1.4 nm a most complete tetragonal unit cell is observed. When crystallization occurs inside SWCNT with Dm < 1.4 nm 1D TbBrx crystal deforms a nanotube to elliptical shape in cross section. In this case the 1D crystal unit cell becomes monoclinic, with possible loss of a part of bromine atoms. Two modifications of a monoclinic unit cell appear. One of them is characterized by single or pair vacancies in the structure of the 1D crystal. Another structure is explained by peripheral and central bromine atoms loss. An appearance of such modifications can be stimulated by electron irradiation. The loss of bromine atoms is in agreement with chemical analysis data. Electronic properties of obtained meta-nanotubes are investigated using optical absorption and Raman spectroscopy. It is shown that intercalation of terbium bromide into SWCNTs leads to acceptor doping of SWCNTs. According to local EDX analysis and elemental mapping this doping can arise from significant stoichiometry change in 1D nanocrystal indicating an average Tb:Br atomic ratio of 1:2.8 ± 0.1.

  12. Analysis of adsorption properties of typical partial discharge gases on Ni-SWCNTs using density functional theory

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoxing; Gui, Yingang; Xiao, Hanyan; Zhang, Ying

    2016-08-01

    To develop novel nanomaterial for online detection and diagnosis of insulated faults in SF6 insulated equipment, the nickel-doped single wall carbon nanotubes (Ni-SWCNTs) are proposed and its sensing capabilities for the measurement of typical decomposition products (SO2, SOF2 and SO2F2) of SF6 insulated gas are investigated in this work. The geometric configurations of decomposition products and (8, 0) zigzag Ni-SWCNTs, and adsorption properties are studied based on the first-principle density functional theory (DFT) methods implemented in the DMol3 package of Materials Studio. Three interaction models, single molecule, double identical molecules and double foreign molecules adsorption, have been studied to fully characterize the gas sensing mechanism under different situations. Simulation results reveal that Ni-SWCNTs have different sensitivity and selectivity to SO2 than SOF2 and SO2F2. The conductivity of Ni-SWCNTs increases in the following order: SO2 > SOF2 after SO2 and SOF2 adsorption. Conversely, the adsorption of SO2F2 onto Ni-SWCNTs slightly decreases its conductivity.

  13. Recent Advances in Synthesis and Characterization of SWCNTs produced by laser oven process

    NASA Technical Reports Server (NTRS)

    Arepalli, Sivaram

    2004-01-01

    Results from the parametric study of the two-laser oven process indicated possible improvements with flow conditions and laser characteristics (ref. 1). Higher flow rates, lower operating pressures coupled with changes in flow tube material are found to improve the nanotube yields. The collected nanotube material is analyzed using a combination of characterization techniques including SEM, TEM, TGA, Raman and UV-VIS-NIR to estimate the purity of the samples. Insitu diagnostics of the laser oven process is now extended to include the surface temperature of the target material. Spectral emission from the target surface is compared with black body type emission to estimate the temperature. The surface temperature seemed to correlate well with the ablation rate as well as the quality of the SWCNTs. Recent changes in improving the production rate by rastering the target and using cw laser will be presented.

  14. Recent Advances in Synthesis and Characterization of SWCNTs Produced by Laser Oven Process

    NASA Technical Reports Server (NTRS)

    Aepalli, Sivaram

    2004-01-01

    Results from the parametric study of the two-laser oven process indicated possible improvements with flow conditions and laser characteristics. Higher flow rates, lower operating pressures coupled with changes in flow tube material are found to improve the nanotube yields. The collected nanotube material is analyzed using a combination of characterization techniques including SEM, TEM, TGA, Raman and UV-VIS-NIR to estimate the purity of the samples. In-situ diagnostics of the laser oven process is now extended to include the surface temperature of the target material. Spectral emission from the target surface is compared with black body type emission to estimate the temperature. The surface temperature seemed to correlate well with the ablation rate as well as the quality of the SWCNTs. Recent changes in improving the production rate by rastering the target and using cw laser will be presented.

  15. Selective and uniform growth of single-wall carbon nanotubes (SWCNTs) for gas sensing application

    NASA Astrophysics Data System (ADS)

    Alvi, M. A.; Al-Ghamdi, A. A.; Khan, Shamshad A.

    2017-03-01

    In the present work, we have synthesized uniformly distributed single-wall carbon nanotube (SWCNT) networks with a selective diameter suitable for gas sensing device. The SWCNT networks have been synthesized on 2-nm-thick iron (Fe) catalyst-coated silicon (Si) substrates by Plasma-Enhanced Chemical Vapor Deposition (PECVD). The as-grown SWCNTs were characterized by field emission scanning electron microscopy, high-resolution transmission electron microscopy, and Raman spectroscopy techniques. Using SWCNT network, the sensitivity of ammonia (NH3) gases/vapors was recognized by their surface adsorption and desorption responses. The response curve was observed from the SWCNT network, which is due to a change in the resistance upon exposure to NH3 gas.

  16. Curriculum Alignment Research Suggests that Alignment Can Improve Student Achievement

    ERIC Educational Resources Information Center

    Squires, David

    2012-01-01

    Curriculum alignment research has developed showing the relationship among three alignment categories: the taught curriculum, the tested curriculum and the written curriculum. Each pair (for example, the taught and the written curriculum) shows a positive impact for aligning those results. Following this, alignment results from the Third…

  17. An investigation of the energy storage properties of a 2D α-MoO3-SWCNTs composite films

    NASA Astrophysics Data System (ADS)

    Mendoza-Sánchez, Beatriz; Hanlon, Damien; Coelho, João; O' Brien, Sean; Pettersson, Henrik; Coleman, Jonathan; Nicolosi, Valeria

    2017-03-01

    We recently reported on the synthesis of 2D α-MoO3 using a scalable liquid-phase exfoliation method, its characterization and preliminary studies of its potential for energy storage applications [1]. The material was examined in a LiClO4/propylene carbonate electrolyte, and in a 1.5-3.5 V versus Li+/Li electrochemical window [1]. The charge storage of 2D α-MoO3 electrodes was negligible and this was attributed to electrical limitations imposed by the semiconducting nature of 2D α-MoO3. Electrical conductivity studies of 2D α-MoO3/SWCNT electrodes, where a fraction of SWCNTs was progressively added, led to finding the SWCNT fraction for which an electrical percolation threshold was reached, i.e. a sharp increase of electrical conductivity. This SWCNT fraction also led to a sharp increase in capacitance confirming the electrical limitation of charge storage. In this work, we examined in detail the energy storage properties of 2D α-MoO3/SWCNT (85 wt%/15 wt%) electrodes. A detailed study of ion-intercalation events, as examined by cyclic voltammetry, is presented. We investigated the contributions to the overall energy storage of capacitive and diffusion-controlled processes and how the performance compares against other nanostructured materials including mesoporous α-MoO3 and α-MoO3 nanobelts. Our main findings showed that 2D α-MoO3/SWCNT (85 wt%/15 wt%) electrodes offer scope for supercapacitors and battery applications in terms of total charge storage (200 F g-1 and 195.2 mAh g-1), which is in the range or superior to that of other nanostructured metal oxides and commercial LiCoO2 cathodes. However, a main drawback is cycling stability.

  18. Improvement of the fracture toughness of hydroxyapatite (HAp) by incorporation of carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and nylon.

    PubMed

    Khanal, S P; Mahfuz, H; Rondinone, A J; Leventouri, Th

    2016-03-01

    The potential of improving the fracture toughness of synthetic hydroxyapatite (HAp) by incorporating carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and polymerized ε-caprolactam (nylon) was studied. A series of HAp samples with CfSWCNTs concentrations varying from 0 to 1.5 wt.%, without, and with nylon addition was prepared. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) were used to characterize the samples. The three point bending test was applied to measure the fracture toughness of the composites. A reproducible value of 3.6±0.3 MPa.√m was found for samples containing 1 wt.% CfSWCNTs and nylon. This value is in the range of the cortical bone fracture toughness. Increase of the CfSWCNTs content results to decrease of the fracture toughness, and formation of secondary phases.

  19. Improvement of the fracture toughness of hydroxyapatite (HAp) by incorporation of carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and nylon

    SciTech Connect

    Khanal, Suraj P.; Mahfuz, Hassan; Rondinone, Adam Justin; Leventouri, Th.

    2015-11-12

    The potential of improving the fracture toughness of synthetic hydroxyapatite (HAp) by incorporating carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and polymerized ε-caprolactam (nylon) was researched. A series of HAp samples with CfSWCNTs concentrations varying from 0 to 1.5 wt.%, without, and with nylon addition was prepared. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) were used to characterize the samples. The three point bending test was applied to measure the fracture toughness of the composites. A reproducible value of 3.6 ± 0.3 MPa.√m was found for samples containing 1 wt.% CfSWCNTs and nylon. This value is in the range of the cortical bone fracture toughness. Lastly, the increase of the CfSWCNTs content results to decrease of the fracture toughness, and formation of secondary phases.

  20. Improvement of the fracture toughness of hydroxyapatite (HAp) by incorporation of carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and nylon

    DOE PAGES

    Khanal, Suraj P.; Mahfuz, Hassan; Rondinone, Adam Justin; ...

    2015-11-12

    The potential of improving the fracture toughness of synthetic hydroxyapatite (HAp) by incorporating carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and polymerized ε-caprolactam (nylon) was researched. A series of HAp samples with CfSWCNTs concentrations varying from 0 to 1.5 wt.%, without, and with nylon addition was prepared. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) were used to characterize the samples. The three point bending test was applied to measure the fracture toughness of the composites. A reproducible value of 3.6 ± 0.3 MPa.√m was found for samples containing 1 wt.% CfSWCNTs and nylon. This valuemore » is in the range of the cortical bone fracture toughness. Lastly, the increase of the CfSWCNTs content results to decrease of the fracture toughness, and formation of secondary phases.« less

  1. Tidal alignment of galaxies

    SciTech Connect

    Blazek, Jonathan; Vlah, Zvonimir; Seljak, Uroš

    2015-08-01

    We develop an analytic model for galaxy intrinsic alignments (IA) based on the theory of tidal alignment. We calculate all relevant nonlinear corrections at one-loop order, including effects from nonlinear density evolution, galaxy biasing, and source density weighting. Contributions from density weighting are found to be particularly important and lead to bias dependence of the IA amplitude, even on large scales. This effect may be responsible for much of the luminosity dependence in IA observations. The increase in IA amplitude for more highly biased galaxies reflects their locations in regions with large tidal fields. We also consider the impact of smoothing the tidal field on halo scales. We compare the performance of this consistent nonlinear model in describing the observed alignment of luminous red galaxies with the linear model as well as the frequently used "nonlinear alignment model," finding a significant improvement on small and intermediate scales. We also show that the cross-correlation between density and IA (the "GI" term) can be effectively separated into source alignment and source clustering, and we accurately model the observed alignment down to the one-halo regime using the tidal field from the fully nonlinear halo-matter cross correlation. Inside the one-halo regime, the average alignment of galaxies with density tracers no longer follows the tidal alignment prediction, likely reflecting nonlinear processes that must be considered when modeling IA on these scales. Finally, we discuss tidal alignment in the context of cosmic shear measurements.

  2. Tidal alignment of galaxies

    SciTech Connect

    Blazek, Jonathan; Vlah, Zvonimir; Seljak, Uroš E-mail: zvlah@stanford.edu

    2015-08-01

    We develop an analytic model for galaxy intrinsic alignments (IA) based on the theory of tidal alignment. We calculate all relevant nonlinear corrections at one-loop order, including effects from nonlinear density evolution, galaxy biasing, and source density weighting. Contributions from density weighting are found to be particularly important and lead to bias dependence of the IA amplitude, even on large scales. This effect may be responsible for much of the luminosity dependence in IA observations. The increase in IA amplitude for more highly biased galaxies reflects their locations in regions with large tidal fields. We also consider the impact of smoothing the tidal field on halo scales. We compare the performance of this consistent nonlinear model in describing the observed alignment of luminous red galaxies with the linear model as well as the frequently used 'nonlinear alignment model,' finding a significant improvement on small and intermediate scales. We also show that the cross-correlation between density and IA (the 'GI' term) can be effectively separated into source alignment and source clustering, and we accurately model the observed alignment down to the one-halo regime using the tidal field from the fully nonlinear halo-matter cross correlation. Inside the one-halo regime, the average alignment of galaxies with density tracers no longer follows the tidal alignment prediction, likely reflecting nonlinear processes that must be considered when modeling IA on these scales. Finally, we discuss tidal alignment in the context of cosmic shear measurements.

  3. MP-Align: alignment of metabolic pathways

    PubMed Central

    2014-01-01

    Background Comparing the metabolic pathways of different species is useful for understanding metabolic functions and can help in studying diseases and engineering drugs. Several comparison techniques for metabolic pathways have been introduced in the literature as a first attempt in this direction. The approaches are based on some simplified representation of metabolic pathways and on a related definition of a similarity score (or distance measure) between two pathways. More recent comparative research focuses on alignment techniques that can identify similar parts between pathways. Results We propose a methodology for the pairwise comparison and alignment of metabolic pathways that aims at providing the largest conserved substructure of the pathways under consideration. The proposed methodology has been implemented in a tool called MP-Align, which has been used to perform several validation tests. The results showed that our similarity score makes it possible to discriminate between different domains and to reconstruct a meaningful phylogeny from metabolic data. The results further demonstrate that our alignment algorithm correctly identifies subpathways sharing a common biological function. Conclusion The results of the validation tests performed with MP-Align are encouraging. A comparison with another proposal in the literature showed that our alignment algorithm is particularly well-suited to finding the largest conserved subpathway of the pathways under examination. PMID:24886436

  4. Anisotropic Polymer Conformations in Aligned SWCNT/PS Nanocomposites

    NASA Astrophysics Data System (ADS)

    Tung, Wei-Shao; Composto, Russell; Clarke, Nigel; Winey, Karen

    2015-03-01

    In our previous study of isotropic SWCNT/polystyrene (PS) nanocomposites, we found that the polymer radius of gyration (Rg) increases and the SWCNT mesh size decreases with increasing SWCNT concentration. Here, we investigate the effect of aligning SWCNTs on Rg and the SWNCT mesh. SWCNT alignment was accomplished by melt fiber spinning or extrusion, and small angle neutron scattering was used to probe the structure. As expected, SWCNT alignment produces anisotropic meshes. Below 2 wt% SWCNT, no significant change in Rg is observed and Rg parallel and perpendicular to the direction of SWCNT alignment are comparable. More interestingly, at higher wt% SWCNT the polymer conformations are anisotropic with a larger Rg perpendicular to the SWCNT than along the SWCNT. For example, with 6 wt% SWCNT, the Rg perpendicular to the SWCNT is ~ 15% larger than parallel to the SWNCT. This anisotropy in the polymer conformation becomes more prominent at higher SWCNT concentrations, perhaps because at higher SWCNT concentrations the distribution of mesh shifts to smaller meshes (<2Rg) so that a single polymer chain interacts with multiple SWCNTs. Implications of this finding will be discussed. National Science Foundation DMR-12-10379.

  5. Alignment validation

    SciTech Connect

    ALICE; ATLAS; CMS; LHCb; Golling, Tobias

    2008-09-06

    The four experiments, ALICE, ATLAS, CMS and LHCb are currently under constructionat CERN. They will study the products of proton-proton collisions at the Large Hadron Collider. All experiments are equipped with sophisticated tracking systems, unprecedented in size and complexity. Full exploitation of both the inner detector andthe muon system requires an accurate alignment of all detector elements. Alignmentinformation is deduced from dedicated hardware alignment systems and the reconstruction of charged particles. However, the system is degenerate which means the data is insufficient to constrain all alignment degrees of freedom, so the techniques are prone to converging on wrong geometries. This deficiency necessitates validation and monitoring of the alignment. An exhaustive discussion of means to validate is subject to this document, including examples and plans from all four LHC experiments, as well as other high energy experiments.

  6. Nanoscale optical and electrical characterization of horizontally aligned single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Rodriguez, Raul D.; Toader, Marius; Hermann, Sascha; Sheremet, Evgeniya; Müller, Susanne; Gordan, Ovidiu D.; Yu, Haibo; Schulz, Stefan E.; Hietschold, Michael; Zahn, Dietrich RT

    2012-12-01

    During the recent years, a significant amount of research has been performed on single-walled carbon nanotubes (SWCNTs) as a channel material in thin-film transistors (Pham et al. IEEE Trans Nanotechnol 11:44-50, 2012). This has prompted the application of advanced characterization techniques based on combined atomic force microscopy (AFM) and Raman spectroscopy studies (Mureau et al. Electrophoresis 29:2266-2271, 2008). In this context, we use confocal Raman microscopy and current sensing atomic force microscopy (CS-AFM) to study phonons and the electronic transport in semiconducting SWCNTs, which were aligned between palladium electrodes using dielectrophoresis (Kuzyk Electrophoresis 32:2307-2313, 2011). Raman imaging was performed in the region around the electrodes on the suspended CNTs using several laser excitation wavelengths. Analysis of the G+/G- splitting in the Raman spectra (Sgobba and Guldi Chem Soc Rev 38:165-184, 2009) shows CNT diameters of 2.5 ± 0.3 nm. Neither surface modification nor increase in defect density or stress at the CNT-electrode contact could be detected, but rather a shift in G+ and G- peak positions in regions with high CNT density between the electrodes. Simultaneous topographical and electrical characterization of the CNT transistor by CS-AFM confirms the presence of CNT bundles having a stable electrical contact with the transistor electrodes. For a similar load force, reproducible current-voltage ( I/ V) curves for the same CNT regions verify the stability of the electrical contact between the nanotube and the electrodes as well as the nanotube and the AFM tip over different experimental sessions using different AFM tips. Strong variations observed in the I/ V response at different regions of the CNT transistor are discussed.

  7. Nanoscale optical and electrical characterization of horizontally aligned single-walled carbon nanotubes

    PubMed Central

    2012-01-01

    During the recent years, a significant amount of research has been performed on single-walled carbon nanotubes (SWCNTs) as a channel material in thin-film transistors (Pham et al. IEEE Trans Nanotechnol 11:44–50, 2012). This has prompted the application of advanced characterization techniques based on combined atomic force microscopy (AFM) and Raman spectroscopy studies (Mureau et al. Electrophoresis 29:2266–2271, 2008). In this context, we use confocal Raman microscopy and current sensing atomic force microscopy (CS-AFM) to study phonons and the electronic transport in semiconducting SWCNTs, which were aligned between palladium electrodes using dielectrophoresis (Kuzyk Electrophoresis 32:2307–2313, 2011). Raman imaging was performed in the region around the electrodes on the suspended CNTs using several laser excitation wavelengths. Analysis of the G+/G− splitting in the Raman spectra (Sgobba and Guldi Chem Soc Rev 38:165–184, 2009) shows CNT diameters of 2.5 ± 0.3 nm. Neither surface modification nor increase in defect density or stress at the CNT-electrode contact could be detected, but rather a shift in G+ and G− peak positions in regions with high CNT density between the electrodes. Simultaneous topographical and electrical characterization of the CNT transistor by CS-AFM confirms the presence of CNT bundles having a stable electrical contact with the transistor electrodes. For a similar load force, reproducible current–voltage (I/V) curves for the same CNT regions verify the stability of the electrical contact between the nanotube and the electrodes as well as the nanotube and the AFM tip over different experimental sessions using different AFM tips. Strong variations observed in the I/V response at different regions of the CNT transistor are discussed. PMID:23259903

  8. Nanoscale optical and electrical characterization of horizontally aligned single-walled carbon nanotubes.

    PubMed

    Rodriguez, Raul D; Toader, Marius; Hermann, Sascha; Sheremet, Evgeniya; Müller, Susanne; Gordan, Ovidiu D; Yu, Haibo; Schulz, Stefan E; Hietschold, Michael; Zahn, Dietrich Rt

    2012-12-21

    During the recent years, a significant amount of research has been performed on single-walled carbon nanotubes (SWCNTs) as a channel material in thin-film transistors (Pham et al. IEEE Trans Nanotechnol 11:44-50, 2012). This has prompted the application of advanced characterization techniques based on combined atomic force microscopy (AFM) and Raman spectroscopy studies (Mureau et al. Electrophoresis 29:2266-2271, 2008). In this context, we use confocal Raman microscopy and current sensing atomic force microscopy (CS-AFM) to study phonons and the electronic transport in semiconducting SWCNTs, which were aligned between palladium electrodes using dielectrophoresis (Kuzyk Electrophoresis 32:2307-2313, 2011). Raman imaging was performed in the region around the electrodes on the suspended CNTs using several laser excitation wavelengths. Analysis of the G+/G- splitting in the Raman spectra (Sgobba and Guldi Chem Soc Rev 38:165-184, 2009) shows CNT diameters of 2.5 ± 0.3 nm. Neither surface modification nor increase in defect density or stress at the CNT-electrode contact could be detected, but rather a shift in G+ and G- peak positions in regions with high CNT density between the electrodes. Simultaneous topographical and electrical characterization of the CNT transistor by CS-AFM confirms the presence of CNT bundles having a stable electrical contact with the transistor electrodes. For a similar load force, reproducible current-voltage (I/V) curves for the same CNT regions verify the stability of the electrical contact between the nanotube and the electrodes as well as the nanotube and the AFM tip over different experimental sessions using different AFM tips. Strong variations observed in the I/V response at different regions of the CNT transistor are discussed.

  9. Superemission in vertically-aligned single-wall carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Khmelinskii, Igor; Makarov, Vladimir

    2016-09-01

    Presently we used two samples of vertically aligned single-wall carbon nanotubes (VA SWCNTs) with parallelepiped geometry, sized 0.02 cm × 0.2 cm × 1.0 cm and 0.2 cm × 0.2 cm × 1.0 cm. We report absorption and emission properties of the VA SWCNTs, including strong anisotropy in both their absorption and emission spectra. We found that the emission spectra extend from the middle-IR range to the near-IR range, with such extended spectra being reported for the first time. Pumping the VA SWCNTs in the direction normal to their axis, superemission (SE) was observed in the direction along their axis. The SE band maximum is located at 7206 ± 0.4 cm-1. The energy and the power density of the superemission were estimated, along with the diffraction-limited divergence. At the pumping energy of 3 mJ/pulse, the SE energy measured by the detector was 0.74 mJ/pulse, corresponding to the total SE energy of 1.48 mJ/pulse, with the energy density of 18.5 mJ cm-2/pulse and the SE power density of 1.2 × 105 W cm-2/pulse. We report that a bundle of VA SWCNTs is an emitter with a relatively small divergence, not exceeding 3.9 × 10-3 rad. We developed a theoretical approach to explain such absorption and emission spectra. The developed theory is based on the earlier proposed SSH theory, which we extended to include the exchange interactions between the closest SWCNT neighbors. The developed theoretical ideas were implemented in a homemade FORTRAN code. This code was successfully used to calculate and reproduce the experimental spectra and to determine the SWCNT species that originate the respective absorption bands, with acceptable agreement between theory and experiment.

  10. Stacking dependent electronic properties of the nanofilms composing of super-aligned single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Tan, Jie; He, Xiujie; Qu, Yuanyuan; Liu, Xiangdong; Zhao, Mingwen

    2015-06-01

    Films composed of super-aligned single-walled carbon nanotubes (SWCNTs) have been widely used in electronic devices. Using first-principles calculations, we investigate the energetically most favorable stacking patterns and the electronic structures of SWCNT monolayers and bilayers formed by super-aligned (5, 5) and (7, 0) SWCNTs. It is found that the (5, 5) SWCNT monolayer prefers a ‘face-by-face’ stacking pattern with the binding energy of 13.90 meV/atom, whereas the (7, 0) SWCNT monolayer favors an ‘edge-by-edge’ pattern with the binding energy of 10.82 meV/atom. The (5, 5) SWCNT arrays are semiconducting with a band gap up to 114 meV for the bilayer, while the (7, 0) SWCNT arrays are metallic with a tiny overlap between valence and conduction bands, in sharp contrast to the cases of isolated (5, 5) and (7, 0) SWCNTs. This implies that weak van der Waals interactions between SWCNTs play an important role in applications of SWCNT films in electronic devices.

  11. ALIGNING JIG

    DOEpatents

    Culver, J.S.; Tunnell, W.C.

    1958-08-01

    A jig or device is described for setting or aligning an opening in one member relative to another member or structure, with a predetermined offset, or it may be used for measuring the amount of offset with which the parts have previously been sct. This jig comprises two blocks rabbeted to each other, with means for securing thc upper block to the lower block. The upper block has fingers for contacting one of the members to be a1igmed, the lower block is designed to ride in grooves within the reference member, and calibration marks are provided to determine the amount of offset. This jig is specially designed to align the collimating slits of a mass spectrometer.

  12. Image alignment

    DOEpatents

    Dowell, Larry Jonathan

    2014-04-22

    Disclosed is a method and device for aligning at least two digital images. An embodiment may use frequency-domain transforms of small tiles created from each image to identify substantially similar, "distinguishing" features within each of the images, and then align the images together based on the location of the distinguishing features. To accomplish this, an embodiment may create equal sized tile sub-images for each image. A "key" for each tile may be created by performing a frequency-domain transform calculation on each tile. A information-distance difference between each possible pair of tiles on each image may be calculated to identify distinguishing features. From analysis of the information-distance differences of the pairs of tiles, a subset of tiles with high discrimination metrics in relation to other tiles may be located for each image. The subset of distinguishing tiles for each image may then be compared to locate tiles with substantially similar keys and/or information-distance metrics to other tiles of other images. Once similar tiles are located for each image, the images may be aligned in relation to the identified similar tiles.

  13. Torsion-sensing material from aligned carbon nanotubes wound onto a rod demonstrating wide dynamic range.

    PubMed

    Yamada, Takeo; Yamamoto, Yuki; Hayamizu, Yuhei; Sekiguchi, Atsuko; Tanaka, Hiroyuki; Kobashi, Kazufumi; Futaba, Don N; Hata, Kenji

    2013-04-23

    A rational torsion sensing material was fabricated by wrapping aligned single-walled carbon nanotube (SWCNT) thin films onto the surface of a rod with a predetermined and fixed wrapping angle without destroying the internal network of the SWCNTs within the film. When applied as a torsion sensor, torsion could be measured up to 400 rad/meter, that is, more than 4 times higher than conventional optical fiber torsion sensors, by monitoring increases in resistance due to fracturing of the aligned SWCNT thin films.

  14. Improving pairwise sequence alignment accuracy using near-optimal protein sequence alignments

    PubMed Central

    2010-01-01

    Background While the pairwise alignments produced by sequence similarity searches are a powerful tool for identifying homologous proteins - proteins that share a common ancestor and a similar structure; pairwise sequence alignments often fail to represent accurately the structural alignments inferred from three-dimensional coordinates. Since sequence alignment algorithms produce optimal alignments, the best structural alignments must reflect suboptimal sequence alignment scores. Thus, we have examined a range of suboptimal sequence alignments and a range of scoring parameters to understand better which sequence alignments are likely to be more structurally accurate. Results We compared near-optimal protein sequence alignments produced by the Zuker algorithm and a set of probabilistic alignments produced by the probA program with structural alignments produced by four different structure alignment algorithms. There is significant overlap between the solution spaces of structural alignments and both the near-optimal sequence alignments produced by commonly used scoring parameters for sequences that share significant sequence similarity (E-values < 10-5) and the ensemble of probA alignments. We constructed a logistic regression model incorporating three input variables derived from sets of near-optimal alignments: robustness, edge frequency, and maximum bits-per-position. A ROC analysis shows that this model more accurately classifies amino acid pairs (edges in the alignment path graph) according to the likelihood of appearance in structural alignments than the robustness score alone. We investigated various trimming protocols for removing incorrect edges from the optimal sequence alignment; the most effective protocol is to remove matches from the semi-global optimal alignment that are outside the boundaries of the local alignment, although trimming according to the model-generated probabilities achieves a similar level of improvement. The model can also be used to

  15. Laser-optic instruments improve machinery alignment

    SciTech Connect

    Bloch, H.P.

    1987-10-12

    Laser-optic alignment systems are fast becoming cost-effective devices that improve the accuracy and speed of machinery shaft alignment. Because of the difficulty, if not impossibility, of aligning operating machinery, cold alignment specifications must be determined to compensate for thermal growth so that the shaft alignment remains within tolerances when the machine reaches normal operating temperature. Some methods for accomplishing this are reviewed here. Three years' field experience with laser-optic alignment systems shows that many of these limitations can be eliminated, resulting in a more accurate alignment in less time. Some actual field alignments are given as examples of the improvement achieved by the use of laser equipment, and a procedure is given that shows how the laser-optic system may be used to determine running alignment changes caused by thermal growth.

  16. Chemical modification of carbon nanomaterials (SWCNTs, DWCNTs, MWCNTs and SWCNHs) with diphenyl dichalcogenides

    NASA Astrophysics Data System (ADS)

    Syrgiannis, Z.; Bonasera, A.; Tenori, E.; La Parola, V.; Hadad, C.; Gruttadauria, M.; Giacalone, F.; Prato, M.

    2015-03-01

    Control over chemical functionalization is a crucial point in the field of nanotechnology. Herein, we present the covalent functionalization of several carbon nanoforms (single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes and carbon nanohorns) by means of diphenyl dichalcogenides. These ones show different reactivity to the nanomaterials and are able to modify their electronic properties depending on the electronegativity of the functionalizing heteroatom. Theoretical calculations were also performed to support the experimental results. All the modified structured nanocarbons were thoroughly characterized by TGA Raman, XPS, UV/Vis/nIR, IR and TEM techniques. Our findings propose a simple approach to functionalize carbon nanomaterials and, in the meantime, to tune their electronic properties.Control over chemical functionalization is a crucial point in the field of nanotechnology. Herein, we present the covalent functionalization of several carbon nanoforms (single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes and carbon nanohorns) by means of diphenyl dichalcogenides. These ones show different reactivity to the nanomaterials and are able to modify their electronic properties depending on the electronegativity of the functionalizing heteroatom. Theoretical calculations were also performed to support the experimental results. All the modified structured nanocarbons were thoroughly characterized by TGA Raman, XPS, UV/Vis/nIR, IR and TEM techniques. Our findings propose a simple approach to functionalize carbon nanomaterials and, in the meantime, to tune their electronic properties. Electronic supplementary information (ESI) available: TGA, Raman spectra analysis. See DOI: 10.1039/c4nr07196d

  17. ALIGN_MTX--an optimal pairwise textual sequence alignment program, adapted for using in sequence-structure alignment.

    PubMed

    Vishnepolsky, Boris; Pirtskhalava, Malak

    2009-06-01

    The presented program ALIGN_MTX makes alignment of two textual sequences with an opportunity to use any several characters for the designation of sequence elements and arbitrary user substitution matrices. It can be used not only for the alignment of amino acid and nucleotide sequences but also for sequence-structure alignment used in threading, amino acid sequence alignment, using preliminary known PSSM matrix, and in other cases when alignment of biological or non-biological textual sequences is required. This distinguishes it from the majority of similar alignment programs that make, as a rule, alignment only of amino acid or nucleotide sequences represented as a sequence of single alphabetic characters. ALIGN_MTX is presented as downloadable zip archive at http://www.imbbp.org/software/ALIGN_MTX/ and available for free use. As application of using the program, the results of comparison of different types of substitution matrix for alignment quality in distantly related protein pair sets were presented. Threading matrix SORDIS, based on side-chain orientation in relation to hydrophobic core centers with evolutionary change-based substitution matrix BLOSUM and using multiple sequence alignment information position-specific score matrices (PSSM) were taken for test alignment accuracy. The best performance shows PSSM matrix, but in the reduced set with lower sequence similarity threading matrix SORDIS shows the same performance and it was shown that combined potential with SORDIS and PSSM can improve alignment quality in evolutionary distantly related protein pairs.

  18. An approach to determination of phenolic compounds in seawater using SPME-GC-MS based on SWCNTs coating

    NASA Astrophysics Data System (ADS)

    Zhu, Jia; Wang, Ying; Zeng, Lin

    2016-08-01

    Phenolic compounds have become one kind of the important pollutants of the marine environment. Single-walled Carbon nanotubes, as one-dimensional nano materials, have light weight and perfect hexagonal structure of connections, with many unusual mechanical, chemical and electrical properties. In recent years, with the research of carbon nanotubes and other nano materials, the application prospect is also constantly discussed. In this paper, homemade single-walled carbon nanotubes (SWCNTs) coating was used for establishing an analytical approach to the determination of five kinds of phenolic compounds in seawater using SPME-GC-MS. Optimal conditions: After saturation was conducted with NaCl, and pH was adjusted to 2.0 with H2SO4, the extract was immersed in a water bath at 40°C for GC-MS determination through 40-min agitating extraction at 500 rmin-1 and 3-min desorption at 280°C. The liniearities ranged between 0.01-100 μg L-1, and the determination limits ranged between 1.5-10 ng L-1. The relative standard deviation (RSD, n = 5) was less than 6.5%. For the phenolic compounds obtained from the spiked recovery test for actual seawater samples, the rates of recovery were 87.5%-101.7%, and the RSDs were less than 8.8%, which met the requirements of determination. Due to its simplicity, high efficiency and low consumption, this approach is suitable for the analysis of trace amounts of phenolic compounds in marine waters.

  19. Lexical alignment in triadic communication

    PubMed Central

    Foltz, Anouschka; Gaspers, Judith; Thiele, Kristina; Stenneken, Prisca; Cimiano, Philipp

    2015-01-01

    Lexical alignment refers to the adoption of one’s interlocutor’s lexical items. Accounts of the mechanisms underlying such lexical alignment differ (among other aspects) in the role assigned to addressee-centered behavior. In this study, we used a triadic communicative situation to test which factors may modulate the extent to which participants’ lexical alignment reflects addressee-centered behavior. Pairs of naïve participants played a picture matching game and received information about the order in which pictures were to be matched from a voice over headphones. On critical trials, participants did or did not hear a name for the picture to be matched next over headphones. Importantly, when the voice over headphones provided a name, it did not match the name that the interlocutor had previously used to describe the object. Participants overwhelmingly used the word that the voice over headphones provided. This result points to non-addressee-centered behavior and is discussed in terms of disrupting alignment with the interlocutor as well as in terms of establishing alignment with the voice over headphones. In addition, the type of picture (line drawing vs. tangram shape) independently modulated lexical alignment, such that participants showed more lexical alignment to their interlocutor for (more ambiguous) tangram shapes compared to line drawings. Overall, the results point to a rather large role for non-addressee-centered behavior during lexical alignment. PMID:25762955

  20. Testing the tidal alignment model of galaxy intrinsic alignment

    SciTech Connect

    Blazek, Jonathan; Seljak, Uroš; McQuinn, Matthew E-mail: mmcquinn@berkeley.edu

    2011-05-01

    Weak gravitational lensing has become a powerful probe of large-scale structure and cosmological parameters. Precision weak lensing measurements require an understanding of the intrinsic alignment of galaxy ellipticities, which can in turn inform models of galaxy formation. It is hypothesized that elliptical galaxies align with the background tidal field and that this alignment mechanism dominates the correlation between ellipticities on cosmological scales (in the absence of lensing). We use recent large-scale structure measurements from the Sloan Digital Sky Survey to test this picture with several statistics: (1) the correlation between ellipticity and galaxy overdensity, w{sub g+}; (2) the intrinsic alignment auto-correlation functions; (3) the correlation functions of curl-free, E, and divergence-free, B, modes, the latter of which is zero in the linear tidal alignment theory; (4) the alignment correlation function, w{sub g}(r{sub p},θ), a recently developed statistic that generalizes the galaxy correlation function to account for the angle between the galaxy separation vector and the principle axis of ellipticity. We show that recent measurements are largely consistent with the tidal alignment model and discuss dependence on galaxy luminosity. In addition, we show that at linear order the tidal alignment model predicts that the angular dependence of w{sub g}(r{sub p},θ) is simply w{sub g+}(r{sub p})cos (2θ) and that this dependence is consistent with recent measurements. We also study how stochastic nonlinear contributions to galaxy ellipticity impact these statistics. We find that a significant fraction of the observed LRG ellipticity can be explained by alignment with the tidal field on scales ∼> 10 \\hMpc. These considerations are relevant to galaxy formation and evolution.

  1. Inflation by alignment

    SciTech Connect

    Burgess, C.P.; Roest, Diederik

    2015-06-08

    Pseudo-Goldstone bosons (pGBs) can provide technically natural inflatons, as has been comparatively well-explored in the simplest axion examples. Although inflationary success requires trans-Planckian decay constants, f≳M{sub p}, several mechanisms have been proposed to obtain this, relying on (mis-)alignments between potential and kinetic energies in multiple-field models. We extend these mechanisms to a broader class of inflationary models, including in particular the exponential potentials that arise for pGB potentials based on noncompact groups (and so which might apply to moduli in an extra-dimensional setting). The resulting potentials provide natural large-field inflationary models and can predict a larger primordial tensor signal than is true for simpler single-field versions of these models. In so doing we provide a unified treatment of several alignment mechanisms, showing how each emerges as a limit of the more general setup.

  2. Magnetic alignment and the Poisson alignment reference system

    NASA Astrophysics Data System (ADS)

    Griffith, L. V.; Schenz, R. F.; Sommargren, G. E.

    1990-08-01

    Three distinct metrological operations are necessary to align a free-electron laser (FEL): the magnetic axis must be located, a straight line reference (SLR) must be generated, and the magnetic axis must be related to the SLR. This article begins with a review of the motivation for developing an alignment system that will assure better than 100-μm accuracy in the alignment of the magnetic axis throughout an FEL. The 100-μm accuracy is an error circle about an ideal axis for 300 m or more. The article describes techniques for identifying the magnetic axes of solenoids, quadrupoles, and wiggler poles. Propagation of a laser beam is described to the extent of revealing sources of nonlinearity in the beam. Development of a straight-line reference based on the Poisson line, a diffraction effect, is described in detail. Spheres in a large-diameter laser beam create Poisson lines and thus provide a necessary mechanism for gauging between the magnetic axis and the SLR. Procedures for installing FEL components and calibrating alignment fiducials to the magnetic axes of the components are also described. The Poisson alignment reference system should be accurate to 25 μm over 300 m, which is believed to be a factor-of-4 improvement over earlier techniques. An error budget shows that only 25% of the total budgeted tolerance is used for the alignment reference system, so the remaining tolerances should fall within the allowable range for FEL alignment.

  3. Microwave and Millimeter Wave Properties of Vertically-Aligned Single Wall Carbon Nanotubes Films

    NASA Astrophysics Data System (ADS)

    Haddadi, K.; Tripon-Canseliet, C.; Hivin, Q.; Ducournau, G.; Teo, E.; Coquet, P.; Tay, B. K.; Lepilliet, S.; Avramovic, V.; Chazelas, J.; Decoster, D.

    2016-05-01

    We present the experimental determination of the complex permittivity of vertically aligned single wall carbon nanotubes (SWCNTs) films grown on quartz substrates in the microwave regime from 10 MHz up to 67 GHz, with the electrical field perpendicular to the main axis of the carbon nanotubes (CNTs), based on coplanar waveguide transmission line approach together with the measurement of the microwave impedance of top metalized vertically—aligned SWCNTs grown on conductive silicon substrates up to 26 GHz. From coplanar waveguide measurements, we obtain a real part of the permittivity almost equal to unity, which is interpreted in terms of low carbon atom density (3 × 1019 at/cm3) associated with a very low imaginary part of permittivity (<10-3) in the frequency range considered due to a very small perpendicular conductivity. The microwave impedance of a vertically aligned CNTs bundle equivalent to a low resistance reveals a good conductivity (3 S/cm) parallel to the CNTs axis. From these two kinds of data, we experimentally demonstrate the tensor nature of the vertically grown CNTs bundles.

  4. Rainbow channeling of protons in very short carbon nanotubes with aligned Stone-Wales defects

    NASA Astrophysics Data System (ADS)

    Ćosić, M.; Petrović, S.; Bellucci, S.

    2016-01-01

    In this paper proton channeling through armchair single-walled-carbon-nanotubes (SWCNTs) with aligned Stone-Wales defects has been investigated. The energy of the proton beam was 1 GeV, while the lengths of the SWCNTs have been varied from 200 nm up to 1000 nm. The linear density of aligned defects has been varied in the whole range, from minimally up to maximally possible values. Here are presented results of a detailed morphological analysis concerning: the formation, evolution and interaction of the nanotube rainbows. The potential of the SWCNT has been constructed from Molère's expression of the Thomas-Fermi's proton-carbon interaction-energy, using the approximation of the continuous atomic string. Trajectories of the channeled protons were obtained by solving the corresponding classical equations of motions. Distributions of the transmitted protons were obtained by the Monte-Carlo simulation. The shape of angular distributions has been explained in the framework of the theory of nanotube rainbows. The aim of this study is also to investigate the applicability of the proton rainbow channeling for the characterization of nanotubes with aligned Stone-Wales defects.

  5. BAYESIAN PROTEIN STRUCTURE ALIGNMENT1

    PubMed Central

    RODRIGUEZ, ABEL; SCHMIDLER, SCOTT C.

    2015-01-01

    The analysis of the three-dimensional structure of proteins is an important topic in molecular biochemistry. Structure plays a critical role in defining the function of proteins and is more strongly conserved than amino acid sequence over evolutionary timescales. A key challenge is the identification and evaluation of structural similarity between proteins; such analysis can aid in understanding the role of newly discovered proteins and help elucidate evolutionary relationships between organisms. Computational biologists have developed many clever algorithmic techniques for comparing protein structures, however, all are based on heuristic optimization criteria, making statistical interpretation somewhat difficult. Here we present a fully probabilistic framework for pairwise structural alignment of proteins. Our approach has several advantages, including the ability to capture alignment uncertainty and to estimate key “gap” parameters which critically affect the quality of the alignment. We show that several existing alignment methods arise as maximum a posteriori estimates under specific choices of prior distributions and error models. Our probabilistic framework is also easily extended to incorporate additional information, which we demonstrate by including primary sequence information to generate simultaneous sequence–structure alignments that can resolve ambiguities obtained using structure alone. This combined model also provides a natural approach for the difficult task of estimating evolutionary distance based on structural alignments. The model is illustrated by comparison with well-established methods on several challenging protein alignment examples. PMID:26925188

  6. Dynamic Alignment at SLS

    SciTech Connect

    Ruland, Robert E.

    2003-04-23

    The relative alignment of components in the storage ring of the Swiss Light Source (SLS) is guaranteed by mechanical means. The magnets are rigidly fixed to 48 girders by means of alignment rails with tolerances of less than {+-}15 {micro}m. The bending magnets, supported by 3 point ball bearings, overlap adjacent girders and thus establish virtual train links between the girders, located near the bending magnet centres. Keeping the distortion of the storage ring geometry within a tolerance of {+-}100 {micro}m in order to guarantee sufficient dynamic apertures, requires continuous monitoring and correction of the girder locations. Two monitoring systems for the horizontal and the vertical direction will be installed to measure displacements of the train link between girders, which are due to ground settings and temperature effects: The hydrostatic levelling system (HLS) gives an absolute vertical reference, while the horizontal positioning system (HPS), which employs low cost linear encoders with sub-micron resolution, measures relative horizontal movements. The girder mover system based on five DC motors per girder allows a dynamic realignment of the storage ring within a working window of more than {+-}1 mm for girder translations and {+-}1 mrad for rotations. We will describe both monitoring systems (HLS and HPS) as well as the applied correction scheme based on the girder movers. We also show simulations indicating that beam based girder alignment takes care of most of the static closed orbit correction.

  7. Magnetic axis alignment and the Poisson alignment reference system

    NASA Astrophysics Data System (ADS)

    Griffith, Lee V.; Schenz, Richard F.; Sommargren, Gary E.

    1989-01-01

    Three distinct metrological operations are necessary to align a free-electron laser (FEL): the magnetic axis must be located, a straight line reference (SLR) must be generated, and the magnetic axis must be related to the SLR. This paper begins with a review of the motivation for developing an alignment system that will assure better than 100 micrometer accuracy in the alignment of the magnetic axis throughout an FEL. The paper describes techniques for identifying the magnetic axis of solenoids, quadrupoles, and wiggler poles. Propagation of a laser beam is described to the extent of revealing sources of nonlinearity in the beam. Development and use of the Poisson line, a diffraction effect, is described in detail. Spheres in a large-diameter laser beam create Poisson lines and thus provide a necessary mechanism for gauging between the magnetic axis and the SLR. Procedures for installing FEL components and calibrating alignment fiducials to the magnetic axes of the components are also described. An error budget shows that the Poisson alignment reference system will make it possible to meet the alignment tolerances for an FEL.

  8. "The Show"

    ERIC Educational Resources Information Center

    Gehring, John

    2004-01-01

    For the past 16 years, the blue-collar city of Huntington, West Virginia, has rolled out the red carpet to welcome young wrestlers and their families as old friends. They have come to town chasing the same dream for a spot in what many of them call "The Show". For three days, under the lights of an arena packed with 5,000 fans, the…

  9. Projection-Based Volume Alignment

    PubMed Central

    Yu, Lingbo; Snapp, Robert R.; Ruiz, Teresa; Radermacher, Michael

    2013-01-01

    When heterogeneous samples of macromolecular assemblies are being examined by 3D electron microscopy (3DEM), often multiple reconstructions are obtained. For example, subtomograms of individual particles can be acquired from tomography, or volumes of multiple 2D classes can be obtained by random conical tilt reconstruction. Of these, similar volumes can be averaged to achieve higher resolution. Volume alignment is an essential step before 3D classification and averaging. Here we present a projection-based volume alignment (PBVA) algorithm. We select a set of projections to represent the reference volume and align them to a second volume. Projection alignment is achieved by maximizing the cross-correlation function with respect to rotation and translation parameters. If data are missing, the cross-correlation functions are normalized accordingly. Accurate alignments are obtained by averaging and quadratic interpolation of the cross-correlation maximum. Comparisons of the computation time between PBVA and traditional 3D cross-correlation methods demonstrate that PBVA outperforms the traditional methods. Performance tests were carried out with different signal-to-noise ratios using modeled noise and with different percentages of missing data using a cryo-EM dataset. All tests show that the algorithm is robust and highly accurate. PBVA was applied to align the reconstructions of a subcomplex of the NADH: ubiquinone oxidoreductase (Complex I) from the yeast Yarrowia lipolytica, followed by classification and averaging. PMID:23410725

  10. National Ignition Facility system alignment.

    PubMed

    Burkhart, S C; Bliss, E; Di Nicola, P; Kalantar, D; Lowe-Webb, R; McCarville, T; Nelson, D; Salmon, T; Schindler, T; Villanueva, J; Wilhelmsen, K

    2011-03-10

    The National Ignition Facility (NIF) is the world's largest optical instrument, comprising 192 37 cm square beams, each generating up to 9.6 kJ of 351 nm laser light in a 20 ns beam precisely tailored in time and spectrum. The Facility houses a massive (10 m diameter) target chamber within which the beams converge onto an ∼1 cm size target for the purpose of creating the conditions needed for deuterium/tritium nuclear fusion in a laboratory setting. A formidable challenge was building NIF to the precise requirements for beam propagation, commissioning the beam lines, and engineering systems to reliably and safely align 192 beams within the confines of a multihour shot cycle. Designing the facility to minimize drift and vibration, placing the optical components in their design locations, commissioning beam alignment, and performing precise system alignment are the key alignment accomplishments over the decade of work described herein. The design and positioning phases placed more than 3000 large (2.5 m×2 m×1 m) line-replaceable optics assemblies to within ±1 mm of design requirement. The commissioning and alignment phases validated clear apertures (no clipping) for all beam lines, and demonstrated automated laser alignment within 10 min and alignment to target chamber center within 44 min. Pointing validation system shots to flat gold-plated x-ray emitting targets showed NIF met its design requirement of ±50 μm rms beam pointing to target chamber. Finally, this paper describes the major alignment challenges faced by the NIF Project from inception to present, and how these challenges were met and solved by the NIF design and commissioning teams.

  11. Triangular Alignment (TAME). A Tensor-based Approach for Higher-order Network Alignment

    SciTech Connect

    Mohammadi, Shahin; Gleich, David F.; Kolda, Tamara G.; Grama, Ananth

    2015-11-01

    Network alignment is an important tool with extensive applications in comparative interactomics. Traditional approaches aim to simultaneously maximize the number of conserved edges and the underlying similarity of aligned entities. We propose a novel formulation of the network alignment problem that extends topological similarity to higher-order structures and provide a new objective function that maximizes the number of aligned substructures. This objective function corresponds to an integer programming problem, which is NP-hard. Consequently, we approximate this objective function as a surrogate function whose maximization results in a tensor eigenvalue problem. Based on this formulation, we present an algorithm called Triangular AlignMEnt (TAME), which attempts to maximize the number of aligned triangles across networks. We focus on alignment of triangles because of their enrichment in complex networks; however, our formulation and resulting algorithms can be applied to general motifs. Using a case study on the NAPABench dataset, we show that TAME is capable of producing alignments with up to 99% accuracy in terms of aligned nodes. We further evaluate our method by aligning yeast and human interactomes. Our results indicate that TAME outperforms the state-of-art alignment methods both in terms of biological and topological quality of the alignments.

  12. The effects of alignment error and alignment filtering on the sitewise detection of positive selection.

    PubMed

    Jordan, Gregory; Goldman, Nick

    2012-04-01

    When detecting positive selection in proteins, the prevalence of errors resulting from misalignment and the ability of alignment filters to mitigate such errors are not well understood, but filters are commonly applied to try to avoid false positive results. Focusing on the sitewise detection of positive selection across a wide range of divergence levels and indel rates, we performed simulation experiments to quantify the false positives and false negatives introduced by alignment error and the ability of alignment filters to improve performance. We found that some aligners led to many false positives, whereas others resulted in very few. False negatives were a problem for all aligners, increasing with sequence divergence. Of the aligners tested, PRANK's codon-based alignments consistently performed the best and ClustalW performed the worst. Of the filters tested, GUIDANCE performed the best and Gblocks performed the worst. Although some filters showed good ability to reduce the error rates from ClustalW and MAFFT alignments, none were found to substantially improve the performance of PRANK alignments under most conditions. Our results revealed distinct trends in error rates and power levels for aligners and filters within a biologically plausible parameter space. With the best aligner, a low false positive rate was maintained even with extremely divergent indel-prone sequences. Controls using the true alignment and an optimal filtering method suggested that performance improvements could be gained by improving aligners or filters to reduce the prevalence of false negatives, especially at higher divergence levels and indel rates.

  13. Girder Alignment Plan

    SciTech Connect

    Wolf, Zackary; Ruland, Robert; LeCocq, Catherine; Lundahl, Eric; Levashov, Yurii; Reese, Ed; Rago, Carl; Poling, Ben; Schafer, Donald; Nuhn, Heinz-Dieter; Wienands, Uli; /SLAC

    2010-11-18

    The girders for the LCLS undulator system contain components which must be aligned with high accuracy relative to each other. The alignment is one of the last steps before the girders go into the tunnel, so the alignment must be done efficiently, on a tight schedule. This note documents the alignment plan which includes efficiency and high accuracy. The motivation for girder alignment involves the following considerations. Using beam based alignment, the girder position will be adjusted until the beam goes through the center of the quadrupole and beam finder wire. For the machine to work properly, the undulator axis must be on this line and the center of the undulator beam pipe must be on this line. The physics reasons for the undulator axis and undulator beam pipe axis to be centered on the beam are different, but the alignment tolerance for both are similar. In addition, the beam position monitor must be centered on the beam to preserve its calibration. Thus, the undulator, undulator beam pipe, quadrupole, beam finder wire, and beam position monitor axes must all be aligned to a common line. All relative alignments are equally important, not just, for example, between quadrupole and undulator. We begin by making the common axis the nominal beam axis in the girder coordinate system. All components will be initially aligned to this axis. A more accurate alignment will then position the components relative to each other, without incorporating the girder itself.

  14. Charge trapping in aligned single-walled carbon nanotube arrays induced by ionizing radiation exposure

    SciTech Connect

    Esqueda, Ivan S.; Cress, Cory D.; Che, Yuchi; Cao, Yu; Zhou, Chongwu

    2014-02-07

    The effects of near-interfacial trapping induced by ionizing radiation exposure of aligned single-walled carbon nanotube (SWCNT) arrays are investigated via measurements of gate hysteresis in the transfer characteristics of aligned SWCNT field-effect transistors. Gate hysteresis is attributed to charge injection (i.e., trapping) from the SWCNTs into radiation-induced traps in regions near the SWCNT/dielectric interface. Self-consistent calculations of surface-potential, carrier density, and trapped charge are used to describe hysteresis as a function of ionizing radiation exposure. Hysteresis width (h) and its dependence on gate sweep range are investigated analytically. The effects of non-uniform trap energy distributions on the relationship between hysteresis, gate sweep range, and total ionizing dose are demonstrated with simulations and verified experimentally.

  15. Cavity alignment using fringe scanning

    NASA Astrophysics Data System (ADS)

    Sinkunaite, Laura Paulina; Kawabe, Keita; Landry, Michael

    2017-01-01

    LIGO employs two 4-km long Fabry-Pérot arm cavities, which need to be aligned in order for an interferometer to be locked on a TEM00 mode. Once the cavity is locked, alignment signals can be derived from wave-front sensors which measure the TEM01 mode content. However, the alignment state is not always good enough for locking on TEM00. Even when this is the case, the alignment can be evaluated using a free swinging cavity, that shows flashes when higher-order modes become resonant. By moving test masses, small changes are made to the mirror orientation, and hence the TEM00 mode can be optimized iteratively. Currently, this is a manual procedure, and thus it is very time-consuming. Therefore, this project is aimed to study another possible way to lock the cavity on the TEM00 mode. Misalignment information can also be extracted from the power of the higher-order modes transmitted through the cavity. This talk will present an algorithm for this alternative and faster way to derive the alignment state of the arm cavities. Supported by APS FIP, NSF, and Caltech SFP.

  16. Chromium and iron determinations in food and herbal plant samples by atomic absorption spectrometry after solid phase extraction on single-walled carbon nanotubes (SWCNTs) disk.

    PubMed

    Soylak, Mustafa; Unsal, Yunus Emre

    2010-06-01

    A preconcentration-separation procedure has been established based on solid phase extraction of Fe(III) and Cr(III) on single-walled carbon nanotubes (SWCNTs) disk. The analyte ions were quantitatively recovered at pH 8.0 on single-walled carbon nanotubes disk that contains 30 mg of nanotube. The influences of matrix components were tolerable. The detection limits for iron and chromium were calculated as 2.12 and 4.08 microg/l, respectively. The presented method was validated by the analysis of lichen (IAEA-336), CRM025-050 Metals on soil and BCR-032 Moroccan Phosphate rock certified reference materials. The method was successfully applied to the preconcentration and separation of iron and chromium in some food and herbal plant samples from Turkey.

  17. The simultaneous electrochemical detection of catechol and hydroquinone with [Cu(Sal-β-Ala)(3,5-DMPz)2]/SWCNTs/GCE.

    PubMed

    Alshahrani, Lina Abdullah; Li, Xi; Luo, Hui; Yang, Linlin; Wang, Mengmeng; Yan, Songling; Liu, Peng; Yang, Yuqin; Li, Quanhua

    2014-11-25

    A glassy carbon electrode was modified with a copper(II) complex [Cu(Sal-β-Ala) (3,5-DMPz)2] (Sal = salicylaldehyde, β-Ala = β-alanine, 3,5-DMPz = 3,5-dimethylpyrazole) and single-walled carbon nanotubes (SWCNTs). The modified electrode was used to detect catechol (CT) and hydroquinone (HQ) and exhibited good electrocatalytic activities toward the oxidation of CT and HQ. The peak currents were linear with the CT and HQ concentrations over the range of 5-215 μmol·L(-1) and 5-370 μmol·L(-1) with corresponding detection limits of 3.5 μmol·L(-1) and 1.46 μmol·L(-1) (S/N = 3) respectively. Moreover, the modified electrode exhibited good sensitivity, stability and reproducibility for the determination of CT and HQ, indicating the promising applications of the modified electrode in real sample analysis.

  18. The Simultaneous Electrochemical Detection of Catechol and Hydroquinone with [Cu(Sal-β-Ala)(3,5-DMPz)2]/SWCNTs/GCE

    PubMed Central

    Alshahrani, Lina Abdullah; Li, Xi; Luo, Hui; Yang, Linlin; Wang, Mengmeng; Yan, Songling; Liu, Peng; Yang, Yuqin; Li, Quanhua

    2014-01-01

    A glassy carbon electrode was modified with a copper(II) complex [Cu(Sal-β-Ala) (3,5-DMPz)2] (Sal = salicylaldehyde, β-Ala = β-alanine, 3,5-DMPz = 3,5-dimethylpyrazole) and single-walled carbon nanotubes (SWCNTs). The modified electrode was used to detect catechol (CT) and hydroquinone (HQ) and exhibited good electrocatalytic activities toward the oxidation of CT and HQ. The peak currents were linear with the CT and HQ concentrations over the range of 5–215 μmol·L−1 and 5–370 μmol·L−1 with corresponding detection limits of 3.5 μmol·L−1 and 1.46 μmol·L−1 (S/N = 3) respectively. Moreover, the modified electrode exhibited good sensitivity, stability and reproducibility for the determination of CT and HQ, indicating the promising applications of the modified electrode in real sample analysis. PMID:25429411

  19. Growth of vertically aligned single-walled carbon nanotubes with metallic chirality through faceted FePt-Au catalysts

    NASA Astrophysics Data System (ADS)

    Ohashi, Toshiyuki; Iwama, Hiroki; Shima, Toshiyuki

    2016-02-01

    Direct synthesis of vertically aligned metallic single-walled carbon nanotubes (m-SWCNT forests) is a difficult challenge. We have successfully synthesized m-SWCNT forests using faceted iron platinum-gold catalysts epitaxially grown on a single crystalline magnesium oxide substrate. The metallic content of the forests estimated by Raman spectroscopy reaches 90%. From the standpoint of growth rate of the forests, the growth mechanism is probably based on the catalyst of solid state. It is suggested that preferential growth of m-SWCNTs is achieved when both factors are satisfied, namely, {111} dominant octahedral facet and ideal size (fine particles) of FePt particles.

  20. The alignment-distribution graph

    NASA Technical Reports Server (NTRS)

    Chatterjee, Siddhartha; Gilbert, John R.; Schreiber, Robert

    1993-01-01

    Implementing a data-parallel language such as Fortran 90 on a distributed-memory parallel computer requires distributing aggregate data objects (such as arrays) among the memory modules attached to the processors. The mapping of objects to the machine determines the amount of residual communication needed to bring operands of parallel operations into alignment with each other. We present a program representation called the alignment-distribution graph that makes these communication requirements explicit. We describe the details of the representation, show how to model communication cost in this framework, and outline several algorithms for determining object mappings that approximately minimize residual communication.

  1. The alignment-distribution graph

    NASA Technical Reports Server (NTRS)

    Chatterjee, Siddhartha; Gilbert, John R.; Schreiber, Robert

    1993-01-01

    Implementing a data-parallel language such as Fortran 90 on a distributed-memory parallel computer requires distributing aggregate data objects (such as arrays) among the memory modules attached to the processors. The mapping of objects to the machine determines the amount of residual communication needed to bring operands of parallel operations into alignment with each other. We present a program representation called the alignment distribution graph that makes these communication requirements explicit. We describe the details of the representation, show how to model communication cost in this framework, and outline several algorithms for determining object mappings that approximately minimize residual communication.

  2. Aligned Defrosting Dunes

    NASA Technical Reports Server (NTRS)

    2004-01-01

    17 August 2004 This July 2004 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a group of aligned barchan sand dunes in the martian north polar region. At the time, the dunes were covered with seasonal frost, but the frost had begun to sublime away, leaving dark spots and dark outlines around the dunes. The surrounding plains exhibit small, diffuse spots that are also the result of subliming seasonal frost. This northern spring image, acquired on a descending ground track (as MGS was moving north to south on the 'night' side of Mars) is located near 78.8oN, 34.8oW. The image covers an area about 3 km (1.9 mi) across and sunlight illuminates the scene from the upper left.

  3. An Improved Inertial Frame Alignment Algorithm Based on Horizontal Alignment Information for Marine SINS.

    PubMed

    Che, Yanting; Wang, Qiuying; Gao, Wei; Yu, Fei

    2015-10-05

    In this paper, an improved inertial frame alignment algorithm for a marine SINS under mooring conditions is proposed, which significantly improves accuracy. Since the horizontal alignment is easy to complete, and a characteristic of gravity is that its component in the horizontal plane is zero, we use a clever method to improve the conventional inertial alignment algorithm. Firstly, a large misalignment angle model and a dimensionality reduction Gauss-Hermite filter are employed to establish the fine horizontal reference frame. Based on this, the projection of the gravity in the body inertial coordinate frame can be calculated easily. Then, the initial alignment algorithm is accomplished through an inertial frame alignment algorithm. The simulation and experiment results show that the improved initial alignment algorithm performs better than the conventional inertial alignment algorithm, and meets the accuracy requirements of a medium-accuracy marine SINS.

  4. Algorithms for Automatic Alignment of Arrays

    NASA Technical Reports Server (NTRS)

    Chatterjee, Siddhartha; Gilbert, John R.; Oliker, Leonid; Schreiber, Robert; Sheffler, Thomas J.

    1996-01-01

    Aggregate data objects (such as arrays) are distributed across the processor memories when compiling a data-parallel language for a distributed-memory machine. The mapping determines the amount of communication needed to bring operands of parallel operations into alignment with each other. A common approach is to break the mapping into two stages: an alignment that maps all the objects to an abstract template, followed by a distribution that maps the template to the processors. This paper describes algorithms for solving the various facets of the alignment problem: axis and stride alignment, static and mobile offset alignment, and replication labeling. We show that optimal axis and stride alignment is NP-complete for general program graphs, and give a heuristic method that can explore the space of possible solutions in a number of ways. We show that some of these strategies can give better solutions than a simple greedy approach proposed earlier. We also show how local graph contractions can reduce the size of the problem significantly without changing the best solution. This allows more complex and effective heuristics to be used. We show how to model the static offset alignment problem using linear programming, and we show that loop-dependent mobile offset alignment is sometimes necessary for optimum performance. We describe an algorithm with for determining mobile alignments for objects within do loops. We also identify situations in which replicated alignment is either required by the program itself or can be used to improve performance. We describe an algorithm based on network flow that replicates objects so as to minimize the total amount of broadcast communication in replication.

  5. Precision alignment device

    DOEpatents

    Jones, N.E.

    1988-03-10

    Apparatus for providing automatic alignment of beam devices having an associated structure for directing, collimating, focusing, reflecting, or otherwise modifying the main beam. A reference laser is attached to the structure enclosing the main beam producing apparatus and produces a reference beam substantially parallel to the main beam. Detector modules containing optical switching devices and optical detectors are positioned in the path of the reference beam and are effective to produce an electrical output indicative of the alignment of the main beam. This electrical output drives servomotor operated adjustment screws to adjust the position of elements of the structure associated with the main beam to maintain alignment of the main beam. 5 figs.

  6. Precision alignment device

    DOEpatents

    Jones, Nelson E.

    1990-01-01

    Apparatus for providing automatic alignment of beam devices having an associated structure for directing, collimating, focusing, reflecting, or otherwise modifying the main beam. A reference laser is attached to the structure enclosing the main beam producing apparatus and produces a reference beam substantially parallel to the main beam. Detector modules containing optical switching devices and optical detectors are positioned in the path of the reference beam and are effective to produce an electrical output indicative of the alignment of the main beam. This electrical output drives servomotor operated adjustment screws to adjust the position of elements of the structure associated with the main beam to maintain alignment of the main beam.

  7. Hybrid vehicle motor alignment

    DOEpatents

    Levin, Michael Benjamin

    2001-07-03

    A rotor of an electric motor for a motor vehicle is aligned to an axis of rotation for a crankshaft of an internal combustion engine having an internal combustion engine and an electric motor. A locator is provided on the crankshaft, a piloting tool is located radially by the first locator to the crankshaft. A stator of the electric motor is aligned to a second locator provided on the piloting tool. The stator is secured to the engine block. The rotor is aligned to the crankshaft and secured thereto.

  8. Alignment of CEBAF cryomodules

    SciTech Connect

    Schneider, W.J.; Bisognano, J.J.; Fischer, J.

    1993-06-01

    CEBAF, the Continuous Electron Beam Accelerator Facility, when completed, will house a 4 GeV recirculating accelerator. Each of the accelerator`s two linacs contains 160 superconducting radio frequency (SRF) 1497 MHz niobium cavities in 20 cryomodules. Alignments of the cavities within the cryomodule with respect to beam axis is critical to achieving the optimum accelerator performance. This paper discusses the rationale for the current specification on cavity mechanical alignment: 2 mrad (rms) applied to the 0.5 m active length cavities. We describe the tooling that was developed to achieve the tolerance at the time of cavity pair assembly, to preserve and integrate alignment during cryomodule assembly, and to translate alignment to appropriate installation in the beam line.

  9. Overlay improvement by zone alignment strategy

    NASA Astrophysics Data System (ADS)

    Huang, Chun-Yen; Lee, Ai-Yi; Shih, Chiang-Lin; Yang, Richer; Yuan, Michael; Chen, Henry; Chang, Ray

    2008-03-01

    It is evident that DRAM ground rule continues to shrink down to 90nm and beyond, overlay performance has become more and more critical and important. Wafer edge shows different behavior from center by processes, e.g. a tremendous misalignment at wafer edge makes yield loss . When a conventional linear model is used for alignment correction, higher uncorrectable overlay residuals mostly happen at wafer edge. Therefore, it's obviously necessary to introduce an innovational alignment correction methdology to reduce unwanted wafer edge effect. In this study, we demonstrate the achievement of moderating poor overlay in wafer edge area by a novel zone-dependent alignment strategy, the so-called "Zone Alignment (ZA)". The main difference between the conventional linear model and zone alignment strategy is that the latter compensates an improper averaging effect from first modeling through weighting all surrounding marks with a nonlinear model. In addition, the effects of mark quantity and sampling distribution from "Zone Alignment" are also introduced in this paper. The results of this study indicate that ZA can reduce uncorrectable overlay residual and improve wafer-to-wafer variation significantly. Furthermore, obvious yield improvement is verified by ZA strategy. In conclusion, Zone alignment is the noteworthy strategy for overlay improvement. Moreover, suitable alignment map and mark numbers should be taken into consideration carefully when ZA is applied for further technology node.

  10. Pairwise Sequence Alignment Library

    SciTech Connect

    Jeff Daily, PNNL

    2015-05-20

    Vector extensions, such as SSE, have been part of the x86 CPU since the 1990s, with applications in graphics, signal processing, and scientific applications. Although many algorithms and applications can naturally benefit from automatic vectorization techniques, there are still many that are difficult to vectorize due to their dependence on irregular data structures, dense branch operations, or data dependencies. Sequence alignment, one of the most widely used operations in bioinformatics workflows, has a computational footprint that features complex data dependencies. The trend of widening vector registers adversely affects the state-of-the-art sequence alignment algorithm based on striped data layouts. Therefore, a novel SIMD implementation of a parallel scan-based sequence alignment algorithm that can better exploit wider SIMD units was implemented as part of the Parallel Sequence Alignment Library (parasail). Parasail features: Reference implementations of all known vectorized sequence alignment approaches. Implementations of Smith Waterman (SW), semi-global (SG), and Needleman Wunsch (NW) sequence alignment algorithms. Implementations across all modern CPU instruction sets including AVX2 and KNC. Language interfaces for C/C++ and Python.

  11. Aligning parallel arrays to reduce communication

    NASA Technical Reports Server (NTRS)

    Sheffler, Thomas J.; Schreiber, Robert; Gilbert, John R.; Chatterjee, Siddhartha

    1994-01-01

    Axis and stride alignment is an important optimization in compiling data-parallel programs for distributed-memory machines. We previously developed an optimal algorithm for aligning array expressions. Here, we examine alignment for more general program graphs. We show that optimal alignment is NP-complete in this setting, so we study heuristic methods. This paper makes two contributions. First, we show how local graph transformations can reduce the size of the problem significantly without changing the best solution. This allows more complex and effective heuristics to be used. Second, we give a heuristic that can explore the space of possible solutions in a number of ways. We show that some of these strategies can give better solutions than a simple greedy approach proposed earlier. Our algorithms have been implemented; we present experimental results showing their effect on the performance of some example programs running on the CM-5.

  12. Shuttle onboard IMU alignment methods

    NASA Technical Reports Server (NTRS)

    Henderson, D. M.

    1976-01-01

    The current approach to the shuttle IMU alignment is based solely on the Apollo Deterministic Method. This method is simple, fast, reliable and provides an accurate estimate for the present cluster to mean of 1,950 transformation matrix. If four or more star sightings are available, the application of least squares analysis can be utilized. The least squares method offers the next level of sophistication to the IMU alignment solution. The least squares method studied shows that a more accurate estimate for the misalignment angles is computed, and the IMU drift rates are a free by-product of the analysis. Core storage requirements are considerably more; estimated 20 to 30 times the core required for the Apollo Deterministic Method. The least squares method offers an intermediate solution utilizing as much data that is available without a complete statistical analysis as in Kalman filtering.

  13. Shod wear and foot alignment in clinical gait analysis.

    PubMed

    Louey, Melissa Gar Yee; Sangeux, Morgan

    2016-09-01

    Sagittal plane alignment of the foot presents challenges when the subject wears shoes during gait analysis. Typically, visual alignment is performed by positioning two markers, the heel and toe markers, aligned with the foot within the shoe. Alternatively, software alignment is possible when the sole of the shoe lies parallel to the ground, and the change in the shoe's sole thickness is measured and entered as a parameter. The aim of this technical note was to evaluate the accuracy of visual and software foot alignment during shod gait analysis. We calculated the static standing ankle angles of 8 participants (mean age: 8.7 years, SD: 2.9 years) wearing bilateral solid ankle foot orthoses (BSAFOs) with and without shoes using the visual and software alignment methods. All participants were able to stand with flat feet in both static trials and the ankle angles obtained in BSAFOs without shoes was considered the reference. We showed that the current implementation of software alignment introduces a bias towards more ankle dorsiflexion, mean=3°, SD=3.4°, p=0.006, and proposed an adjusted software alignment method. We found no statistical differences using visual alignment and adjusted software alignment between the shoe and shoeless conditions, p=0.19 for both. Visual alignment or adjusted software alignment are advised to represent foot alignment accurately.

  14. Collective alignment of polar filaments by molecular motors.

    PubMed

    Ziebert, F; Vershinin, M; Gross, S P; Aranson, I S

    2009-04-01

    We study the alignment of polar biofilaments, such as microtubules and actin, subject to the action of multiple molecular motors attached simultaneously to more than one filament. Focusing on a paradigm model of only two filaments interacting with multiple motors, we were able to investigate in detail the alignment dynamics. While almost no alignment occurs in the case of a single motor, the filaments become rapidly aligned due to the collective action of the motors. Our analysis shows that the alignment time is governed by the number of bound motors and the magnitude of the motors' stepping fluctuations. We predict that the time scale of alignment is in the order of seconds, much faster than that reported for passive crosslink-induced bundling. In vitro experiments on the alignment of microtubules by multiple-motor covered beads are in qualitative agreement. We also discuss another mode of fast alignment of filaments, namely the cooperation between motors and passive crosslinks.

  15. Magnetically Aligned Supramolecular Hydrogels

    PubMed Central

    Wallace, Matthew; Cardoso, Andre Zamith; Frith, William J; Iggo, Jonathan A; Adams, Dave J

    2014-01-01

    The magnetic-field-induced alignment of the fibrillar structures present in an aqueous solution of a dipeptide gelator, and the subsequent retention of this alignment upon transformation to a hydrogel upon the addition of CaCl2 or upon a reduction in solution pH is reported. Utilising the switchable nature of the magnetic field coupled with the slow diffusion of CaCl2, it is possible to precisely control the extent of anisotropy across a hydrogel, something that is generally very difficult to do using alternative methods. The approach is readily extended to other compounds that form viscous solutions at high pH. It is expected that this work will greatly expand the utility of such low-molecular-weight gelators (LMWG) in areas where alignment is key. PMID:25345918

  16. Improved docking alignment system

    NASA Technical Reports Server (NTRS)

    Monford, Leo G. (Inventor)

    1988-01-01

    Improved techniques are provided for the alignment of two objects. The present invention is particularly suited for 3-D translation and 3-D rotational alignment of objects in outer space. A camera is affixed to one object, such as a remote manipulator arm of the spacecraft, while the planar reflective surface is affixed to the other object, such as a grapple fixture. A monitor displays in real-time images from the camera such that the monitor displays both the reflected image of the camera and visible marking on the planar reflective surface when the objects are in proper alignment. The monitor may thus be viewed by the operator and the arm manipulated so that the reflective surface is perpendicular to the optical axis of the camera, the roll of the reflective surface is at a selected angle with respect to the camera, and the camera is spaced a pre-selected distance from the reflective surface.

  17. MUSE optical alignment procedure

    NASA Astrophysics Data System (ADS)

    Laurent, Florence; Renault, Edgard; Loupias, Magali; Kosmalski, Johan; Anwand, Heiko; Bacon, Roland; Boudon, Didier; Caillier, Patrick; Daguisé, Eric; Dubois, Jean-Pierre; Dupuy, Christophe; Kelz, Andreas; Lizon, Jean-Louis; Nicklas, Harald; Parès, Laurent; Remillieux, Alban; Seifert, Walter; Valentin, Hervé; Xu, Wenli

    2012-09-01

    MUSE (Multi Unit Spectroscopic Explorer) is a second generation VLT integral field spectrograph (1x1arcmin² Field of View) developed for the European Southern Observatory (ESO), operating in the visible wavelength range (0.465-0.93 μm). A consortium of seven institutes is currently assembling and testing MUSE in the Integration Hall of the Observatoire de Lyon for the Preliminary Acceptance in Europe, scheduled for 2013. MUSE is composed of several subsystems which are under the responsibility of each institute. The Fore Optics derotates and anamorphoses the image at the focal plane. A Splitting and Relay Optics feed the 24 identical Integral Field Units (IFU), that are mounted within a large monolithic instrument mechanical structure. Each IFU incorporates an image slicer, a fully refractive spectrograph with VPH-grating and a detector system connected to a global vacuum and cryogenic system. During 2011, all MUSE subsystems were integrated, aligned and tested independently in each institute. After validations, the systems were shipped to the P.I. institute at Lyon and were assembled in the Integration Hall This paper describes the end-to-end optical alignment procedure of the MUSE instrument. The design strategy, mixing an optical alignment by manufacturing (plug and play approach) and few adjustments on key components, is presented. We depict the alignment method for identifying the optical axis using several references located in pupil and image planes. All tools required to perform the global alignment between each subsystem are described. The success of this alignment approach is demonstrated by the good results for the MUSE image quality. MUSE commissioning at the VLT (Very Large Telescope) is planned for 2013.

  18. PILOT optical alignment

    NASA Astrophysics Data System (ADS)

    Longval, Y.; Mot, B.; Ade, P.; André, Y.; Aumont, J.; Baustista, L.; Bernard, J.-Ph.; Bray, N.; de Bernardis, P.; Boulade, O.; Bousquet, F.; Bouzit, M.; Buttice, V.; Caillat, A.; Charra, M.; Chaigneau, M.; Crane, B.; Crussaire, J.-P.; Douchin, F.; Doumayrou, E.; Dubois, J.-P.; Engel, C.; Etcheto, P.; Gélot, P.; Griffin, M.; Foenard, G.; Grabarnik, S.; Hargrave, P..; Hughes, A.; Laureijs, R.; Lepennec, Y.; Leriche, B.; Maestre, S.; Maffei, B.; Martignac, J.; Marty, C.; Marty, W.; Masi, S.; Mirc, F.; Misawa, R.; Montel, J.; Montier, L.; Narbonne, J.; Nicot, J.-M.; Pajot, F.; Parot, G.; Pérot, E.; Pimentao, J.; Pisano, G.; Ponthieu, N.; Ristorcelli, I.; Rodriguez, L.; Roudil, G.; Salatino, M.; Savini, G.; Simonella, O.; Saccoccio, M.; Tapie, P.; Tauber, J.; Torre, J.-P.; Tucker, C.

    2016-07-01

    PILOT is a balloon-borne astronomy experiment designed to study the polarization of dust emission in the diffuse interstellar medium in our Galaxy at wavelengths 240 μm with an angular resolution about two arcminutes. Pilot optics is composed an off-axis Gregorian type telescope and a refractive re-imager system. All optical elements, except the primary mirror, are in a cryostat cooled to 3K. We combined the optical, 3D dimensional measurement methods and thermo-elastic modeling to perform the optical alignment. The talk describes the system analysis, the alignment procedure, and finally the performances obtained during the first flight in September 2015.

  19. Sparse alignment for robust tensor learning.

    PubMed

    Lai, Zhihui; Wong, Wai Keung; Xu, Yong; Zhao, Cairong; Sun, Mingming

    2014-10-01

    Multilinear/tensor extensions of manifold learning based algorithms have been widely used in computer vision and pattern recognition. This paper first provides a systematic analysis of the multilinear extensions for the most popular methods by using alignment techniques, thereby obtaining a general tensor alignment framework. From this framework, it is easy to show that the manifold learning based tensor learning methods are intrinsically different from the alignment techniques. Based on the alignment framework, a robust tensor learning method called sparse tensor alignment (STA) is then proposed for unsupervised tensor feature extraction. Different from the existing tensor learning methods, L1- and L2-norms are introduced to enhance the robustness in the alignment step of the STA. The advantage of the proposed technique is that the difficulty in selecting the size of the local neighborhood can be avoided in the manifold learning based tensor feature extraction algorithms. Although STA is an unsupervised learning method, the sparsity encodes the discriminative information in the alignment step and provides the robustness of STA. Extensive experiments on the well-known image databases as well as action and hand gesture databases by encoding object images as tensors demonstrate that the proposed STA algorithm gives the most competitive performance when compared with the tensor-based unsupervised learning methods.

  20. Molecular focusing and alignment with plasmon fields.

    PubMed

    Artamonov, Maxim; Seideman, Tamar

    2010-12-08

    We show the possibility of simultaneously aligning molecules and focusing their center-of-mass motion near a metal nanoparticle in the field intensity gradient created by the surface plasmon enhancement of incident light. The rotational motion is described quantum mechanically while the translation is treated classically. The effects of the nanoparticle shape on the alignment and focusing are explored. Our results carry interesting implications to the field of molecular nanoplasmonics and suggest several potential applications in nanochemistry.

  1. Aligned-or Not?

    ERIC Educational Resources Information Center

    Roseman, Jo Ellen; Koppal, Mary

    2015-01-01

    When state leaders and national partners in the development of the Next Generation Science Standards met to consider implementation strategies, states and school districts wanted to know which materials were aligned to the new standards. The answer from the developers was short but not sweet: You won't find much now, and it's going to…

  2. Optically Aligned Drill Press

    NASA Technical Reports Server (NTRS)

    Adderholdt, Bruce M.

    1994-01-01

    Precise drill press equipped with rotary-indexing microscope. Microscope and drill exchange places when turret rotated. Microscope axis first aligned over future hole, then rotated out of way so drill axis assumes its precise position. New procedure takes less time to locate drilling positions and produces more accurate results. Apparatus adapted to such other machine tools as milling and measuring machines.

  3. Curriculum Alignment: Establishing Coherence

    ERIC Educational Resources Information Center

    Gagné, Philippe; Dumont, Laurence; Brunet, Sabine; Boucher, Geneviève

    2013-01-01

    In this paper, we present a step-by-step guide to implement a curricular alignment project, directed at professional development and student support, and developed in a higher education French as a second language department. We outline best practices and preliminary results from our experience and provide ways to adapt our experience to other…

  4. The meaning of alignment: lessons from structural diversity

    PubMed Central

    Pirovano, Walter; Feenstra, K Anton; Heringa, Jaap

    2008-01-01

    Background Protein structural alignment provides a fundamental basis for deriving principles of functional and evolutionary relationships. It is routinely used for structural classification and functional characterization of proteins and for the construction of sequence alignment benchmarks. However, the available techniques do not fully consider the implications of protein structural diversity and typically generate a single alignment between sequences. Results We have taken alternative protein crystal structures and generated simulation snapshots to explicitly investigate the impact of structural changes on the alignments. We show that structural diversity has a significant effect on structural alignment. Moreover, we observe alignment inconsistencies even for modest spatial divergence, implying that the biological interpretation of alignments is less straightforward than commonly assumed. A salient example is the GroES 'mobile loop' where sub-Ångstrom variations give rise to contradictory sequence alignments. Conclusion A comprehensive treatment of ambiguous alignment regions is crucial for further development of structural alignment applications and for the representation of alignments in general. For this purpose we have developed an on-line database containing our data and new ways of visualizing alignment inconsistencies, which can be found at . PMID:19105835

  5. Erasing Errors due to Alignment Ambiguity When Estimating Positive Selection

    PubMed Central

    Redelings, Benjamin

    2014-01-01

    Current estimates of diversifying positive selection rely on first having an accurate multiple sequence alignment. Simulation studies have shown that under biologically plausible conditions, relying on a single estimate of the alignment from commonly used alignment software can lead to unacceptably high false-positive rates in detecting diversifying positive selection. We present a novel statistical method that eliminates excess false positives resulting from alignment error by jointly estimating the degree of positive selection and the alignment under an evolutionary model. Our model treats both substitutions and insertions/deletions as sequence changes on a tree and allows site heterogeneity in the substitution process. We conduct inference starting from unaligned sequence data by integrating over all alignments. This approach naturally accounts for ambiguous alignments without requiring ambiguously aligned sites to be identified and removed prior to analysis. We take a Bayesian approach and conduct inference using Markov chain Monte Carlo to integrate over all alignments on a fixed evolutionary tree topology. We introduce a Bayesian version of the branch-site test and assess the evidence for positive selection using Bayes factors. We compare two models of differing dimensionality using a simple alternative to reversible-jump methods. We also describe a more accurate method of estimating the Bayes factor using Rao-Blackwellization. We then show using simulated data that jointly estimating the alignment and the presence of positive selection solves the problem with excessive false positives from erroneous alignments and has nearly the same power to detect positive selection as when the true alignment is known. We also show that samples taken from the posterior alignment distribution using the software BAli-Phy have substantially lower alignment error compared with MUSCLE, MAFFT, PRANK, and FSA alignments. PMID:24866534

  6. MUSE alignment onto VLT

    NASA Astrophysics Data System (ADS)

    Laurent, Florence; Renault, Edgard; Boudon, Didier; Caillier, Patrick; Daguisé, Eric; Dupuy, Christophe; Jarno, Aurélien; Lizon, Jean-Louis; Migniau, Jean-Emmanuel; Nicklas, Harald; Piqueras, Laure

    2014-07-01

    MUSE (Multi Unit Spectroscopic Explorer) is a second generation Very Large Telescope (VLT) integral field spectrograph developed for the European Southern Observatory (ESO). It combines a 1' x 1' field of view sampled at 0.2 arcsec for its Wide Field Mode (WFM) and a 7.5"x7.5" field of view for its Narrow Field Mode (NFM). Both modes will operate with the improved spatial resolution provided by GALACSI (Ground Atmospheric Layer Adaptive Optics for Spectroscopic Imaging), that will use the VLT deformable secondary mirror and 4 Laser Guide Stars (LGS) foreseen in 2015. MUSE operates in the visible wavelength range (0.465-0.93 μm). A consortium of seven institutes is currently commissioning MUSE in the Very Large Telescope for the Preliminary Acceptance in Chile, scheduled for September, 2014. MUSE is composed of several subsystems which are under the responsibility of each institute. The Fore Optics derotates and anamorphoses the image at the focal plane. A Splitting and Relay Optics feed the 24 identical Integral Field Units (IFU), that are mounted within a large monolithic structure. Each IFU incorporates an image slicer, a fully refractive spectrograph with VPH-grating and a detector system connected to a global vacuum and cryogenic system. During 2012 and 2013, all MUSE subsystems were integrated, aligned and tested to the P.I. institute at Lyon. After successful PAE in September 2013, MUSE instrument was shipped to the Very Large Telescope in Chile where that was aligned and tested in ESO integration hall at Paranal. After, MUSE was directly transported, fully aligned and without any optomechanical dismounting, onto VLT telescope where the first light was overcame the 7th of February, 2014. This paper describes the alignment procedure of the whole MUSE instrument with respect to the Very Large Telescope (VLT). It describes how 6 tons could be move with accuracy better than 0.025mm and less than 0.25 arcmin in order to reach alignment requirements. The success

  7. Automatic Word Alignment

    DTIC Science & Technology

    2014-02-18

    strategy was evalu­ ated in the context of English -to-Pashto (E2P) and Pashto-to- English (P2E), a low-resource language pair. For E2P, the training and...improves the quality of automatic word alignment, for example for resource poor language pairs, thus improving Statistical Machine Translation (SMT...example for resource poor language pairs, thus improving Statistical Machine Translation (SMT) performance. 15. SUBJECT TERMS 16. SECURITY

  8. Orbit IMU alignment: Error analysis

    NASA Technical Reports Server (NTRS)

    Corson, R. W.

    1980-01-01

    A comprehensive accuracy analysis of orbit inertial measurement unit (IMU) alignments using the shuttle star trackers was completed and the results are presented. Monte Carlo techniques were used in a computer simulation of the IMU alignment hardware and software systems to: (1) determine the expected Space Transportation System 1 Flight (STS-1) manual mode IMU alignment accuracy; (2) investigate the accuracy of alignments in later shuttle flights when the automatic mode of star acquisition may be used; and (3) verify that an analytical model previously used for estimating the alignment error is a valid model. The analysis results do not differ significantly from expectations. The standard deviation in the IMU alignment error for STS-1 alignments was determined to the 68 arc seconds per axis. This corresponds to a 99.7% probability that the magnitude of the total alignment error is less than 258 arc seconds.

  9. Nuclear reactor alignment plate configuration

    SciTech Connect

    Altman, David A; Forsyth, David R; Smith, Richard E; Singleton, Norman R

    2014-01-28

    An alignment plate that is attached to a core barrel of a pressurized water reactor and fits within slots within a top plate of a lower core shroud and upper core plate to maintain lateral alignment of the reactor internals. The alignment plate is connected to the core barrel through two vertically-spaced dowel pins that extend from the outside surface of the core barrel through a reinforcement pad and into corresponding holes in the alignment plate. Additionally, threaded fasteners are inserted around the perimeter of the reinforcement pad and into the alignment plate to further secure the alignment plate to the core barrel. A fillet weld also is deposited around the perimeter of the reinforcement pad. To accomodate thermal growth between the alignment plate and the core barrel, a gap is left above, below and at both sides of one of the dowel pins in the alignment plate holes through with the dowel pins pass.

  10. Multiple protein structure alignment.

    PubMed Central

    Taylor, W. R.; Flores, T. P.; Orengo, C. A.

    1994-01-01

    A method was developed to compare protein structures and to combine them into a multiple structure consensus. Previous methods of multiple structure comparison have only concatenated pairwise alignments or produced a consensus structure by averaging coordinate sets. The current method is a fusion of the fast structure comparison program SSAP and the multiple sequence alignment program MULTAL. As in MULTAL, structures are progressively combined, producing intermediate consensus structures that are compared directly to each other and all remaining single structures. This leads to a hierarchic "condensation," continually evaluated in the light of the emerging conserved core regions. Following the SSAP approach, all interatomic vectors were retained with well-conserved regions distinguished by coherent vector bundles (the structural equivalent of a conserved sequence position). Each bundle of vectors is summarized by a resultant, whereas vector coherence is captured in an error term, which is the only distinction between conserved and variable positions. Resultant vectors are used directly in the comparison, which is weighted by their error values, giving greater importance to the matching of conserved positions. The resultant vectors and their errors can also be used directly in molecular modeling. Applications of the method were assessed by the quality of the resulting sequence alignments, phylogenetic tree construction, and databank scanning with the consensus. Visual assessment of the structural superpositions and consensus structure for various well-characterized families confirmed that the consensus had identified a reasonable core. PMID:7849601

  11. Observational Evidence for Radiative Interstellar Grain Alignment

    NASA Astrophysics Data System (ADS)

    Andersson, B.; Potter, S. B.; Andersson, B.; Potter, S.

    2011-11-01

    The alignment mechanisms of interstellar dust grains is a long standing astrophysical problem. Interstellar polarization was first discovered in 1949 and soon thereafter attributed to dichroic extinction caused by asymmetric dust grains aligned with the magnetic field. For a long time the alignment mechanism was thought to involve paramagnetic relaxation in rapidly spinning dust grains. Modern theory indicates that the classical alignment mechanisms are likely not efficient, but rather favor alignment through direct radiative torques. We have used multi-band polarimetry towards stars probing six nearby clouds to show that the wavelength of maximum polarization is linearly correlated with the visual extinction (Andersson & Potter 2007; AP07; where further details can be found). We find a universal relation with a common positive slope between the clouds and a DC offset correlated with the average of the total-to-selective extinction < RV > . These results provide strong observational support for radiatively driven grain alignment. Recent observations of an additional set of ≍60 sightlines in the Taurus cloud confirm and strengthen these results.

  12. Aligning Biomolecular Networks Using Modular Graph Kernels

    NASA Astrophysics Data System (ADS)

    Towfic, Fadi; Greenlee, M. Heather West; Honavar, Vasant

    Comparative analysis of biomolecular networks constructed using measurements from different conditions, tissues, and organisms offer a powerful approach to understanding the structure, function, dynamics, and evolution of complex biological systems. We explore a class of algorithms for aligning large biomolecular networks by breaking down such networks into subgraphs and computing the alignment of the networks based on the alignment of their subgraphs. The resulting subnetworks are compared using graph kernels as scoring functions. We provide implementations of the resulting algorithms as part of BiNA, an open source biomolecular network alignment toolkit. Our experiments using Drosophila melanogaster, Saccharomyces cerevisiae, Mus musculus and Homo sapiens protein-protein interaction networks extracted from the DIP repository of protein-protein interaction data demonstrate that the performance of the proposed algorithms (as measured by % GO term enrichment of subnetworks identified by the alignment) is competitive with some of the state-of-the-art algorithms for pair-wise alignment of large protein-protein interaction networks. Our results also show that the inter-species similarity scores computed based on graph kernels can be used to cluster the species into a species tree that is consistent with the known phylogenetic relationships among the species.

  13. A Unified Model of Grain Alignment: Radiative Alignment of Interstellar Grains with Magnetic Inclusions

    NASA Astrophysics Data System (ADS)

    Hoang, Thiem; Lazarian, A.

    2016-11-01

    The radiative torque (RAT) alignment of interstellar grains with ordinary paramagnetic susceptibilities has been supported by earlier studies. The alignment of such grains depends on the so-called RAT parameter q max, which is determined by the grain shape. In this paper, we elaborate on our model of RAT alignment for grains with enhanced magnetic susceptibility due to iron inclusions, such that RAT alignment is magnetically enhanced, which we term the MRAT mechanism. Such grains can be aligned with high angular momentum at the so-called high-J attractor points, achieving a high degree of alignment. Using our analytical model of RATs, we derive the critical value of the magnetic relaxation parameter δ m to produce high-J attractor points as functions of q max and the anisotropic radiation angle relative to the magnetic field ψ. We find that if about 10% of the total iron abundance present in silicate grains is forming iron clusters, this is sufficient to produce high-J attractor points for all reasonable values of q max. To calculate the degree of grain alignment, we carry out numerical simulations of MRAT alignment by including stochastic excitations from gas collisions and magnetic fluctuations. We show that large grains can achieve perfect alignment when the high-J attractor point is present, regardless of the values of q max. Our obtained results pave the way for the physical modeling of polarized thermal dust emission as well as magnetic dipole emission. We also find that millimeter-sized grains in accretion disks may be aligned with the magnetic field if they are incorporated with iron nanoparticles.

  14. Method for alignment of microwires

    DOEpatents

    Beardslee, Joseph A.; Lewis, Nathan S.; Sadtler, Bryce

    2017-01-24

    A method of aligning microwires includes modifying the microwires so they are more responsive to a magnetic field. The method also includes using a magnetic field so as to magnetically align the microwires. The method can further include capturing the microwires in a solid support structure that retains the longitudinal alignment of the microwires when the magnetic field is not applied to the microwires.

  15. Alignment as a Teacher Variable

    ERIC Educational Resources Information Center

    Porter, Andrew C.; Smithson, John; Blank, Rolf; Zeidner, Timothy

    2007-01-01

    With the exception of the procedures developed by Porter and colleagues (Porter, 2002), other methods of defining and measuring alignment are essentially limited to alignment between tests and standards. Porter's procedures have been generalized to investigating the alignment between content standards, tests, textbooks, and even classroom…

  16. Precision alignment and mounting apparatus

    NASA Technical Reports Server (NTRS)

    Preston, Dennis R. (Inventor)

    1993-01-01

    An alignment and mounting apparatus for mounting two modules (10,12) includes a first portion having a cylindrical alignment pin (16) projecting normal to a module surface, a second portion having a three-stage alignment guide (18) including a shoehorn flange (34), a Y-slot (42) and a V-block (22) which sequentially guide the alignment pin (16) with successively finer precision and a third portion in the form of a spring-loaded captive fastener (20) for connecting the two modules after alignment is achieved.

  17. CAB-Align: A Flexible Protein Structure Alignment Method Based on the Residue-Residue Contact Area

    PubMed Central

    Terashi, Genki; Takeda-Shitaka, Mayuko

    2015-01-01

    Proteins are flexible, and this flexibility has an essential functional role. Flexibility can be observed in loop regions, rearrangements between secondary structure elements, and conformational changes between entire domains. However, most protein structure alignment methods treat protein structures as rigid bodies. Thus, these methods fail to identify the equivalences of residue pairs in regions with flexibility. In this study, we considered that the evolutionary relationship between proteins corresponds directly to the residue–residue physical contacts rather than the three-dimensional (3D) coordinates of proteins. Thus, we developed a new protein structure alignment method, contact area-based alignment (CAB-align), which uses the residue–residue contact area to identify regions of similarity. The main purpose of CAB-align is to identify homologous relationships at the residue level between related protein structures. The CAB-align procedure comprises two main steps: First, a rigid-body alignment method based on local and global 3D structure superposition is employed to generate a sufficient number of initial alignments. Then, iterative dynamic programming is executed to find the optimal alignment. We evaluated the performance and advantages of CAB-align based on four main points: (1) agreement with the gold standard alignment, (2) alignment quality based on an evolutionary relationship without 3D coordinate superposition, (3) consistency of the multiple alignments, and (4) classification agreement with the gold standard classification. Comparisons of CAB-align with other state-of-the-art protein structure alignment methods (TM-align, FATCAT, and DaliLite) using our benchmark dataset showed that CAB-align performed robustly in obtaining high-quality alignments and generating consistent multiple alignments with high coverage and accuracy rates, and it performed extremely well when discriminating between homologous and nonhomologous pairs of proteins in both

  18. CAB-Align: A Flexible Protein Structure Alignment Method Based on the Residue-Residue Contact Area.

    PubMed

    Terashi, Genki; Takeda-Shitaka, Mayuko

    2015-01-01

    Proteins are flexible, and this flexibility has an essential functional role. Flexibility can be observed in loop regions, rearrangements between secondary structure elements, and conformational changes between entire domains. However, most protein structure alignment methods treat protein structures as rigid bodies. Thus, these methods fail to identify the equivalences of residue pairs in regions with flexibility. In this study, we considered that the evolutionary relationship between proteins corresponds directly to the residue-residue physical contacts rather than the three-dimensional (3D) coordinates of proteins. Thus, we developed a new protein structure alignment method, contact area-based alignment (CAB-align), which uses the residue-residue contact area to identify regions of similarity. The main purpose of CAB-align is to identify homologous relationships at the residue level between related protein structures. The CAB-align procedure comprises two main steps: First, a rigid-body alignment method based on local and global 3D structure superposition is employed to generate a sufficient number of initial alignments. Then, iterative dynamic programming is executed to find the optimal alignment. We evaluated the performance and advantages of CAB-align based on four main points: (1) agreement with the gold standard alignment, (2) alignment quality based on an evolutionary relationship without 3D coordinate superposition, (3) consistency of the multiple alignments, and (4) classification agreement with the gold standard classification. Comparisons of CAB-align with other state-of-the-art protein structure alignment methods (TM-align, FATCAT, and DaliLite) using our benchmark dataset showed that CAB-align performed robustly in obtaining high-quality alignments and generating consistent multiple alignments with high coverage and accuracy rates, and it performed extremely well when discriminating between homologous and nonhomologous pairs of proteins in both

  19. Frameshift alignment: statistics and post-genomic applications

    PubMed Central

    Frith, Martin C.; Spouge, John L.

    2014-01-01

    Motivation: The alignment of DNA sequences to proteins, allowing for frameshifts, is a classic method in sequence analysis. It can help identify pseudogenes (which accumulate mutations), analyze raw DNA and RNA sequence data (which may have frameshift sequencing errors), investigate ribosomal frameshifts, etc. Often, however, only ad hoc approximations or simulations are available to provide the statistical significance of a frameshift alignment score. Results: We describe a method to estimate statistical significance of frameshift alignments, similar to classic BLAST statistics. (BLAST presently does not permit its alignments to include frameshifts.) We also illustrate the continuing usefulness of frameshift alignment with two ‘post-genomic’ applications: (i) when finding pseudogenes within the human genome, frameshift alignments show that most anciently conserved non-coding human elements are recent pseudogenes with conserved ancestral genes; and (ii) when analyzing metagenomic DNA reads from polluted soil, frameshift alignments show that most alignable metagenomic reads contain frameshifts, suggesting that metagenomic analysis needs to use frameshift alignment to derive accurate results. Availability and implementation: The statistical calculation is available in FALP (http://www.ncbi.nlm.nih.gov/CBBresearch/Spouge/html_ncbi/html/index/software.html), and giga-scale frameshift alignment is available in LAST (http://last.cbrc.jp/falp). Contact: spouge@ncbi.nlm.nih.gov or martin@cbrc.jp Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25172925

  20. Engineering cell alignment in vitro.

    PubMed

    Li, Yuhui; Huang, Guoyou; Zhang, Xiaohui; Wang, Lin; Du, Yanan; Lu, Tian Jian; Xu, Feng

    2014-01-01

    Cell alignment plays a critical role in various cell behaviors including cytoskeleton reorganization, membrane protein relocation, nucleus gene expression, and ECM remodeling. Cell alignment is also known to exert significant effects on tissue regeneration (e.g., neuron) and modulate mechanical properties of tissues including skeleton, cardiac muscle and tendon. Therefore, it is essential to engineer cell alignment in vitro for biomechanics, cell biology, tissue engineering and regenerative medicine applications. With advances in nano- and micro-scale technologies, a variety of approaches have been developed to engineer cell alignment in vitro, including mechanical loading, topographical patterning, and surface chemical treatment. In this review, we first present alignments of various cell types and their functionality in different tissues in vivo including muscle and nerve tissues. Then, we provide an overview of recent approaches for engineering cell alignment in vitro. Finally, concluding remarks and perspectives are addressed for future improvement of engineering cell alignment.

  1. TSGC and JSC Alignment

    NASA Technical Reports Server (NTRS)

    Sanchez, Humberto

    2013-01-01

    NASA and the SGCs are, by design, intended to work closely together and have synergistic Vision, Mission, and Goals. The TSGC affiliates and JSC have been working together, but not always in a concise, coordinated, nor strategic manner. Today we have a couple of simple ideas to present about how TSGC and JSC have started to work together in a more concise, coordinated, and strategic manner, and how JSC and non-TSG Jurisdiction members have started to collaborate: Idea I: TSGC and JSC Technical Alignment Idea II: Concept of Clusters.

  2. Inexact Local Alignment Search over Suffix Arrays.

    PubMed

    Ghodsi, Mohammadreza; Pop, Mihai

    2009-11-01

    We describe an algorithm for finding approximate seeds for DNA homology searches. In contrast to previous algorithms that use exact or spaced seeds, our approximate seeds may contain insertions and deletions. We present a generalized heuristic for finding such seeds efficiently and prove that the heuristic does not affect sensitivity. We show how to adapt this algorithm to work over the memory efficient suffix array with provably minimal overhead in running time.We demonstrate the effectiveness of our algorithm on two tasks: whole genome alignment of bacteria and alignment of the DNA sequences of 177 genes that are orthologous in human and mouse. We show our algorithm achieves better sensitivity and uses less memory than other commonly used local alignment tools.

  3. Multiple network alignment on quantum computers

    NASA Astrophysics Data System (ADS)

    Daskin, Anmer; Grama, Ananth; Kais, Sabre

    2014-12-01

    Comparative analyses of graph-structured datasets underly diverse problems. Examples of these problems include identification of conserved functional components (biochemical interactions) across species, structural similarity of large biomolecules, and recurring patterns of interactions in social networks. A large class of such analyses methods quantify the topological similarity of nodes across networks. The resulting correspondence of nodes across networks, also called node alignment, can be used to identify invariant subgraphs across the input graphs. Given graphs as input, alignment algorithms use topological information to assign a similarity score to each -tuple of nodes, with elements (nodes) drawn from each of the input graphs. Nodes are considered similar if their neighbors are also similar. An alternate, equivalent view of these network alignment algorithms is to consider the Kronecker product of the input graphs and to identify high-ranked nodes in the Kronecker product graph. Conventional methods such as PageRank and HITS (Hypertext-Induced Topic Selection) can be used for this purpose. These methods typically require computation of the principal eigenvector of a suitably modified Kronecker product matrix of the input graphs. We adopt this alternate view of the problem to address the problem of multiple network alignment. Using the phase estimation algorithm, we show that the multiple network alignment problem can be efficiently solved on quantum computers. We characterize the accuracy and performance of our method and show that it can deliver exponential speedups over conventional (non-quantum) methods.

  4. Reducing beam shaper alignment complexity: diagnostic techniques for alignment and tuning

    NASA Astrophysics Data System (ADS)

    Lizotte, Todd E.

    2011-10-01

    methodology showing how it is possible to reduce complex alignment directions into a simplified set of instructions for layman service engineers.

  5. Mango: multiple alignment with N gapped oligos.

    PubMed

    Zhang, Zefeng; Lin, Hao; Li, Ming

    2008-06-01

    Multiple sequence alignment is a classical and challenging task. The problem is NP-hard. The full dynamic programming takes too much time. The progressive alignment heuristics adopted by most state-of-the-art works suffer from the "once a gap, always a gap" phenomenon. Is there a radically new way to do multiple sequence alignment? In this paper, we introduce a novel and orthogonal multiple sequence alignment method, using both multiple optimized spaced seeds and new algorithms to handle these seeds efficiently. Our new algorithm processes information of all sequences as a whole and tries to build the alignment vertically, avoiding problems caused by the popular progressive approaches. Because the optimized spaced seeds have proved significantly more sensitive than the consecutive k-mers, the new approach promises to be more accurate and reliable. To validate our new approach, we have implemented MANGO: Multiple Alignment with N Gapped Oligos. Experiments were carried out on large 16S RNA benchmarks, showing that MANGO compares favorably, in both accuracy and speed, against state-of-the-art multiple sequence alignment methods, including ClustalW 1.83, MUSCLE 3.6, MAFFT 5.861, ProbConsRNA 1.11, Dialign 2.2.1, DIALIGN-T 0.2.1, T-Coffee 4.85, POA 2.0, and Kalign 2.0. We have further demonstrated the scalability of MANGO on very large datasets of repeat elements. MANGO can be downloaded at http://www.bioinfo.org.cn/mango/ and is free for academic usage.

  6. Extracting the polarizability anisotropy from the transient alignment of HBr.

    PubMed

    Pinkham, D; Vogt, T; Jones, R R

    2008-08-14

    We use 40 fs, 780 nm laser pulses to transiently align HBr molecules. We study the temporal dynamics of the resultant rotational wavepacket to gain insight into the electronic properties of the molecule. We show that the HBr polarization anisotropy can be extracted by comparing the time dependence of the HBr alignment with both the analogous alignment behavior of N(2) and the predictions of a rigid-rotor model.

  7. Alignment of multiple proteins with an ensemble of Hidden Markov Models

    PubMed Central

    Song, Yinglei; Qu, Junfeng; Hura, Gurdeep S.

    2011-01-01

    In this paper, we developed a new method that progressively construct and update a set of alignments by adding sequences in certain order to each of the existing alignments. Each of the existing alignments is modelled with a profile Hidden Markov Model (HMM) and an added sequence is aligned to each of these profile HMMs. We introduced an integer parameter for the number of profile HMMs. The profile HMMs are then updated based on the alignments with leading scores. Our experiments on BaliBASE showed that our approach could efficiently explore the alignment space and significantly improve the alignment accuracy. PMID:20376922

  8. Alignment of voids in the cosmic web

    NASA Astrophysics Data System (ADS)

    Platen, Erwin; van de Weygaert, Rien; Jones, Bernard J. T.

    2008-06-01

    We investigate the shapes and mutual alignment of voids in the large-scale matter distribution of a Λ cold dark matter (ΛCDM) cosmology simulation. The voids are identified using the novel watershed void finder (WVF) technique. The identified voids are quite non-spherical and slightly prolate, with axis ratios in the order of c:b:a ~ 0.5:0.7:1. Their orientations are strongly correlated with significant alignments spanning scales >30h-1Mpc. We also find an intimate link between the cosmic tidal field and the void orientations. Over a very wide range of scales we find a coherent and strong alignment of the voids with the tidal field computed from the smoothed density distribution. This orientation-tide alignment remains significant on scales exceeding twice the typical void size, which shows that the long-range external field is responsible for the alignment of the voids. This confirms the view that the large-scale tidal force field is the main agent for the large-scale spatial organization of the cosmic web.

  9. FRESCO: flexible alignment with rectangle scoring schemes.

    PubMed

    Dalca, A V; Brudno, M

    2008-01-01

    While the popular DNA sequence alignment tools incorporate powerful heuristics to allow for fast and accurate alignment of DNA, most of them still optimize the classical Needleman Wunsch scoring scheme. The development of novel scoring schemes is often hampered by the difficulty of finding an optimizing algorithm for each non-trivial scheme. In this paper we define the broad class of rectangle scoring schemes, and describe an algorithm and tool that can align two sequences with an arbitrary rectangle scoring scheme in polynomial time. Rectangle scoring schemes encompass some of the popular alignment scoring metrics currently in use, as well as many other functions. We investigate a novel scoring function based on minimizing the expected number of random diagonals observed with the given scores and show that it rivals the LAGAN and Clustal-W aligners, without using any biological or evolutionary parameters. The FRESCO program, freely available at http://compbio.cs.toronto.edu/fresco, gives bioinformatics researchers the ability to quickly compare the performance of other complex scoring formulas without having to implement new algorithms to optimize them.

  10. Leveraging FPGAs for Accelerating Short Read Alignment.

    PubMed

    Arram, James; Kaplan, Thomas; Luk, Wayne; Jiang, Peiyong

    2016-02-29

    One of the key challenges facing genomics today is how to efficiently analyse the massive amounts of data produced by next-generation sequencing platforms. With general-purpose computing systems struggling to address this challenge, specialised processors such as the Field-Programmable Gate Array (FPGA) are receiving growing interest. The means by which to leverage this technology for accelerating genomic data analysis is however largely unexplored. In this paper we present a runtime reconfigurable architecture for accelerating short read alignment using FPGAs. This architecture exploits the reconfigurability of FPGAs to allow the development of fast yet flexible alignment designs. We apply this architecture to develop an alignment design which supports exact and approximate alignment with up to 2 mismatches. Our design is based on the FM-index, with optimisations to improve the alignment performance. In particular, the n-step FM-index, index oversampling, a seedand- compare stage, and bi-directional backtracking are included. Our design is implemented and evaluated on a 1U Maxeler MPC-X2000 dataflow node with 8 Altera Stratix-V FPGAs. Measurements show that our design is 28 times faster than Bowtie2 running with 16 threads on dual Intel Xeon E5-2640 CPUs, and 9 times faster than Soap3-dp running on an NVIDIA Tesla C2070 GPU.

  11. Onorbit IMU alignment error budget

    NASA Technical Reports Server (NTRS)

    Corson, R. W.

    1980-01-01

    The Star Tracker, Crew Optical Alignment Sight (COAS), and Inertial Measurement Unit (IMU) from a complex navigation system with a multitude of error sources were combined. A complete list of the system errors is presented. The errors were combined in a rational way to yield an estimate of the IMU alignment accuracy for STS-1. The expected standard deviation in the IMU alignment error for STS-1 type alignments was determined to be 72 arc seconds per axis for star tracker alignments and 188 arc seconds per axis for COAS alignments. These estimates are based on current knowledge of the star tracker, COAS, IMU, and navigation base error specifications, and were partially verified by preliminary Monte Carlo analysis.

  12. Nova laser alignment control system

    SciTech Connect

    Van Arsdall, P.J.; Holloway, F.W.; McGuigan, D.L.; Shelton, R.T.

    1984-03-29

    Alignment of the Nova laser requires control of hundreds of optical components in the ten beam paths. Extensive application of computer technology makes daily alignment practical. The control system is designed in a manner which provides both centralized and local manual operator controls integrated with automatic closed loop alignment. Menudriven operator consoles using high resolution color graphics displays overlaid with transport touch panels allow laser personnel to interact efficiently with the computer system. Automatic alignment is accomplished by using image analysis techniques to determine beam references points from video images acquired along the laser chain. A major goal of the design is to contribute substantially to rapid experimental turnaround and consistent alignment results. This paper describes the computer-based control structure and the software methods developed for aligning this large laser system.

  13. Nuclear reactor internals alignment configuration

    DOEpatents

    Gilmore, Charles B.; Singleton, Norman R.

    2009-11-10

    An alignment system that employs jacking block assemblies and alignment posts around the periphery of the top plate of a nuclear reactor lower internals core shroud to align an upper core plate with the lower internals and the core shroud with the core barrel. The distal ends of the alignment posts are chamfered and are closely received within notches machined in the upper core plate at spaced locations around the outer circumference of the upper core plate. The jacking block assemblies are used to center the core shroud in the core barrel and the alignment posts assure the proper orientation of the upper core plate. The alignment posts may alternately be formed in the upper core plate and the notches may be formed in top plate.

  14. Alignment Layers for Ferro and Antiferroelectric Liquid Crystal Cells

    NASA Astrophysics Data System (ADS)

    Negi, Yuvraj Singh; Yamamoto, Norio; Suzuki, Yoshiichi; Kawamura, Ichiro; Yamada, Yuichiro; Kakimoto, Masa-aki; Imai, Yoshio

    1992-12-01

    Aromatic fluorine and nonfluorine containing polyimides, polyamide-imides and polyamides were developed and utilized as alignment layers in ferroelectric (FLC) and antiferroelectric liquid crystal (AFLC) cells. The FLC and AFLC blend (AFLCB-1) of liquid crystals used in the experiment were CS-1011 and [S(-)4-(1-methylheptyloxycarbonyl) phenyl-4-octyloxybiphenyl-4-carboxylate (MHPOBC), R(+)4-(1-trifluoromethylheptyloxy carbonyl)phenyl-4-octyloxybiphenyl-4-carboxylate (TFMHPOBC), and other homologues, [AFLCB-1], respectively. The alignment layer deposited over an ITO-coated glass electrode plate with 2 μm cell gap showed good or random alignment of liquid crystal in FLC and AFLC cells. The AFLC cells exhibited contrast ratio values greater than 10:1 depending on the molecular structure of the alignment layer. The alignment quality of FLC and AFLC cells was also compared by using different molecular structure of polymer alignment layers.

  15. High-harmonic spectroscopy of aligned molecules

    NASA Astrophysics Data System (ADS)

    Yun, Hyeok; Yun, Sang Jae; Lee, Gae Hwang; Nam, Chang Hee

    2017-01-01

    High harmonics emitted from aligned molecules driven by intense femtosecond laser pulses provide the opportunity to explore the structural information of molecules. The field-free molecular alignment technique is an expedient tool for investigating the structural characteristics of linear molecules. The underlying physics of field-free alignment, showing the characteristic revival structure specific to molecular species, is clearly explained from the quantum-phase analysis of molecular rotational states. The anisotropic nature of molecules is shown from the harmonic polarization measurement performed with spatial interferometry. The multi-orbital characteristics of molecules are investigated using high-harmonic spectroscopy, applied to molecules of N2 and CO2. In the latter case the two-dimensional high-harmonic spectroscopy, implemented using a two-color laser field, is applied to distinguish harmonics from different orbitals. Molecular high-harmonic spectroscopy will open a new route to investigate ultrafast dynamics of molecules.

  16. Lunar Alignments - Identification and Analysis

    NASA Astrophysics Data System (ADS)

    González-García, A. César

    Lunar alignments are difficult to establish given the apparent lack of written accounts clearly pointing toward lunar alignments for individual temples. While some individual cases are reviewed and highlighted, the weight of the proof must fall on statistical sampling. Some definitions for the lunar alignments are provided in order to clarify the targets, and thus, some new tools are provided to try to test the lunar hypothesis in several cases, especially in megalithic astronomy.

  17. The alignment strategy of HADES

    NASA Astrophysics Data System (ADS)

    Pechenova, O.; Pechenov, V.; Galatyuk, T.; Hennino, T.; Holzmann, R.; Kornakov, G.; Markert, J.; Müntz, C.; Salabura, P.; Schmah, A.; Schwab, E.; Stroth, J.

    2015-06-01

    The global as well as intrinsic alignment of any spectrometer impacts directly on its performance and the quality of the achievable physics results. An overview of the current alignment procedure of the DiElectron Spectrometer HADES is presented with an emphasis on its main features and its accuracy. The sequence of all steps and procedures is given, including details on photogrammetric and track-based alignment.

  18. Alignment of Helical Membrane Protein Sequences Using AlignMe

    PubMed Central

    Khafizov, Kamil; Forrest, Lucy R.

    2013-01-01

    Few sequence alignment methods have been designed specifically for integral membrane proteins, even though these important proteins have distinct evolutionary and structural properties that might affect their alignments. Existing approaches typically consider membrane-related information either by using membrane-specific substitution matrices or by assigning distinct penalties for gap creation in transmembrane and non-transmembrane regions. Here, we ask whether favoring matching of predicted transmembrane segments within a standard dynamic programming algorithm can improve the accuracy of pairwise membrane protein sequence alignments. We tested various strategies using a specifically designed program called AlignMe. An updated set of homologous membrane protein structures, called HOMEP2, was used as a reference for optimizing the gap penalties. The best of the membrane-protein optimized approaches were then tested on an independent reference set of membrane protein sequence alignments from the BAliBASE collection. When secondary structure (S) matching was combined with evolutionary information (using a position-specific substitution matrix (P)), in an approach we called AlignMePS, the resultant pairwise alignments were typically among the most accurate over a broad range of sequence similarities when compared to available methods. Matching transmembrane predictions (T), in addition to evolutionary information, and secondary-structure predictions, in an approach called AlignMePST, generally reduces the accuracy of the alignments of closely-related proteins in the BAliBASE set relative to AlignMePS, but may be useful in cases of extremely distantly related proteins for which sequence information is less informative. The open source AlignMe code is available at https://sourceforge.net/projects/alignme/, and at http://www.forrestlab.org, along with an online server and the HOMEP2 data set. PMID:23469223

  19. Two Hybrid Algorithms for Multiple Sequence Alignment

    NASA Astrophysics Data System (ADS)

    Naznin, Farhana; Sarker, Ruhul; Essam, Daryl

    2010-01-01

    In order to design life saving drugs, such as cancer drugs, the design of Protein or DNA structures has to be accurate. These structures depend on Multiple Sequence Alignment (MSA). MSA is used to find the accurate structure of Protein and DNA sequences from existing approximately correct sequences. To overcome the overly greedy nature of the well known global progressive alignment method for multiple sequence alignment, we have proposed two different algorithms in this paper; one is using an iterative approach with a progressive alignment method (PAMIM) and the second one is using a genetic algorithm with a progressive alignment method (PAMGA). Both of our methods started with a "kmer" distance table to generate single guide-tree. In the iterative approach, we have introduced two new techniques: the first technique is to generate Guide-trees with randomly selected sequences and the second is of shuffling the sequences inside that tree. The output of the tree is a multiple sequence alignment which has been evaluated by the Sum of Pairs Method (SPM) considering the real value data from PAM250. In our second GA approach, these two techniques are used to generate an initial population and also two different approaches of genetic operators are implemented in crossovers and mutation. To test the performance of our two algorithms, we have compared these with the existing well known methods: T-Coffee, MUSCEL, MAFFT and Probcon, using BAliBase benchmarks. The experimental results show that the first algorithm works well for some situations, where other existing methods face difficulties in obtaining better solutions. The proposed second method works well compared to the existing methods for all situations and it shows better performance over the first one.

  20. GS-align for glycan structure alignment and similarity measurement

    PubMed Central

    Lee, Hui Sun; Jo, Sunhwan; Mukherjee, Srayanta; Park, Sang-Jun; Skolnick, Jeffrey; Lee, Jooyoung; Im, Wonpil

    2015-01-01

    Motivation: Glycans play critical roles in many biological processes, and their structural diversity is key for specific protein-glycan recognition. Comparative structural studies of biological molecules provide useful insight into their biological relationships. However, most computational tools are designed for protein structure, and despite their importance, there is no currently available tool for comparing glycan structures in a sequence order- and size-independent manner. Results: A novel method, GS-align, is developed for glycan structure alignment and similarity measurement. GS-align generates possible alignments between two glycan structures through iterative maximum clique search and fragment superposition. The optimal alignment is then determined by the maximum structural similarity score, GS-score, which is size-independent. Benchmark tests against the Protein Data Bank (PDB) N-linked glycan library and PDB homologous/non-homologous N-glycoprotein sets indicate that GS-align is a robust computational tool to align glycan structures and quantify their structural similarity. GS-align is also applied to template-based glycan structure prediction and monosaccharide substitution matrix generation to illustrate its utility. Availability and implementation: http://www.glycanstructure.org/gsalign. Contact: wonpil@ku.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25857669

  1. Mask alignment system for semiconductor processing

    DOEpatents

    Webb, Aaron P.; Carlson, Charles T.; Weaver, William T.; Grant, Christopher N.

    2017-02-14

    A mask alignment system for providing precise and repeatable alignment between ion implantation masks and workpieces. The system includes a mask frame having a plurality of ion implantation masks loosely connected thereto. The mask frame is provided with a plurality of frame alignment cavities, and each mask is provided with a plurality of mask alignment cavities. The system further includes a platen for holding workpieces. The platen may be provided with a plurality of mask alignment pins and frame alignment pins configured to engage the mask alignment cavities and frame alignment cavities, respectively. The mask frame can be lowered onto the platen, with the frame alignment cavities moving into registration with the frame alignment pins to provide rough alignment between the masks and workpieces. The mask alignment cavities are then moved into registration with the mask alignment pins, thereby shifting each individual mask into precise alignment with a respective workpiece.

  2. Well-pump alignment system

    DOEpatents

    Drumheller, Douglas S.

    1998-01-01

    An improved well-pump for geothermal wells, an alignment system for a well-pump, and to a method for aligning a rotor and stator within a well-pump, wherein the well-pump has a whistle assembly formed at a bottom portion thereof, such that variations in the frequency of the whistle, indicating misalignment, may be monitored during pumping.

  3. CATO: The Clone Alignment Tool.

    PubMed

    Henstock, Peter V; LaPan, Peter

    2016-01-01

    High-throughput cloning efforts produce large numbers of sequences that need to be aligned, edited, compared with reference sequences, and organized as files and selected clones. Different pieces of software are typically required to perform each of these tasks. We have designed a single piece of software, CATO, the Clone Alignment Tool, that allows a user to align, evaluate, edit, and select clone sequences based on comparisons to reference sequences. The input and output are designed to be compatible with standard data formats, and thus suitable for integration into a clone processing pipeline. CATO provides both sequence alignment and visualizations to facilitate the analysis of cloning experiments. The alignment algorithm matches each of the relevant candidate sequences against each reference sequence. The visualization portion displays three levels of matching: 1) a top-level summary of the top candidate sequences aligned to each reference sequence, 2) a focused alignment view with the nucleotides of matched sequences displayed against one reference sequence, and 3) a pair-wise alignment of a single reference and candidate sequence pair. Users can select the minimum matching criteria for valid clones, edit or swap reference sequences, and export the results to a summary file as part of the high-throughput cloning workflow.

  4. Drive alignment pays maintenance dividends

    SciTech Connect

    Fedder, R.

    2008-12-15

    Proper alignment of the motor and gear drive on conveying and processing equipment will result in longer bearing and coupling life, along with lower maintenance costs. Selecting an alignment free drive package instead of a traditional foot mounted drive and motor is a major advancement toward these goals. 4 photos.

  5. Liquid crystallinity driven highly aligned large graphene oxide composites

    SciTech Connect

    Lee, Kyung Eun; Oh, Jung Jae; Yun, Taeyeong; Kim, Sang Ouk

    2015-04-15

    Graphene is an emerging graphitic carbon materials, consisting of sp{sup 2} hybridized two dimensinal honeycomb structure. It has been widely studied to incorporate graphene with polymer to utilize unique property of graphene and reinforce electrical, mechanical and thermal property of polymer. In composite materials, orientation control of graphene significantly influences the property of composite. Until now, a few method has been developed for orientation control of graphene within polymer matrix. Here, we demonstrate facile fabrication of high aligned large graphene oxide (LGO) composites in polydimethylsiloxane (PDMS) matrix exploiting liquid crystallinity. Liquid crystalline aqueous dispersion of LGO is parallel oriented within flat confinement geometry. Freeze-drying of the aligned LGO dispersion and subsequent infiltration with PDMS produce highly aligned LGO/PDMS composites. Owing to the large shape anisotropy of LGO, liquid crystalline alignment occurred at low concentration of 2 mg/ml in aqueous dispersion, which leads to the 0.2 wt% LGO loaded composites. - Graphical abstract: Liquid crystalline LGO aqueous dispersions are spontaneous parallel aligned between geometric confinement for highly aligned LGO/polymer composite fabrication. - Highlights: • A simple fabrication method for highly aligned LGO/PDMS composites is proposed. • LGO aqueous dispersion shows nematic liquid crystalline phase at 0.8 mg/ml. • In nematic phase, LGO flakes are highly aligned by geometric confinement. • Infiltration of PDMS into freeze-dried LGO allows highly aligned LGO/PDMS composites.

  6. Ontology Alignment Repair through Modularization and Confidence-Based Heuristics.

    PubMed

    Santos, Emanuel; Faria, Daniel; Pesquita, Catia; Couto, Francisco M

    2015-01-01

    Ontology Matching aims at identifying a set of semantic correspondences, called an alignment, between related ontologies. In recent years, there has been a growing interest in efficient and effective matching methods for large ontologies. However, alignments produced for large ontologies are often logically incoherent. It was only recently that the use of repair techniques to improve the coherence of ontology alignments began to be explored. This paper presents a novel modularization technique for ontology alignment repair which extracts fragments of the input ontologies that only contain the necessary classes and relations to resolve all detectable incoherences. The paper presents also an alignment repair algorithm that uses a global repair strategy to minimize both the degree of incoherence and the number of mappings removed from the alignment, while overcoming the scalability problem by employing the proposed modularization technique. Our evaluation shows that our modularization technique produces significantly small fragments of the ontologies and that our repair algorithm produces more complete alignments than other current alignment repair systems, while obtaining an equivalent degree of incoherence. Additionally, we also present a variant of our repair algorithm that makes use of the confidence values of the mappings to improve alignment repair. Our repair algorithm was implemented as part of AgreementMakerLight, a free and open-source ontology matching system.

  7. Alignment of the Fibrin Network Within an Autologous Plasma Clot.

    PubMed

    Gessmann, Jan; Seybold, Dominik; Peter, Elvira; Schildhauer, Thomas Armin; Köller, Manfred

    2016-01-01

    Autologous plasma clots with longitudinally aligned fibrin fibers could serve as a scaffold for longitudinal axonal regrowth in cases of traumatic peripheral nerve injuries. Three different techniques for assembling longitudinally oriented fibrin fibers during the fibrin polymerization process were investigated as follows: fiber alignment was induced by the application of either a magnetic field or-as a novel approach-electric field or by the induction of orientated flow. Fiber alignment was characterized by scanning electron microscopy analysis followed by image processing using fast Fourier transformation (FFT). Besides FFT output images, area xmin to xmax, as well as full width at half maximum (FWHM) of the FFT graph plot peaks, was calculated to determine the relative degree of fiber alignment. In addition, fluorescently labeled human fibrinogen and mesenchymal stem cells (MSCs) were used to visualize fibrin and cell orientation in aligned and nonaligned plasma clots. Varying degrees of fiber alignment were achieved by the three different methods, with the electric field application producing the highest degree of fiber alignment. The embedded MSCs showed a longitudinal orientation in the electric field-aligned plasma clots. The key feature of this study is the ability to produce autologous plasma clots with aligned fibrin fibers using physical techniques. This orientated internal structure of an autologous biomaterial is promising for distinct therapeutic applications, such as a guiding structure for cell migration and growth dynamics.

  8. Ontology Alignment Repair through Modularization and Confidence-Based Heuristics

    PubMed Central

    Santos, Emanuel; Faria, Daniel; Pesquita, Catia; Couto, Francisco M.

    2015-01-01

    Ontology Matching aims at identifying a set of semantic correspondences, called an alignment, between related ontologies. In recent years, there has been a growing interest in efficient and effective matching methods for large ontologies. However, alignments produced for large ontologies are often logically incoherent. It was only recently that the use of repair techniques to improve the coherence of ontology alignments began to be explored. This paper presents a novel modularization technique for ontology alignment repair which extracts fragments of the input ontologies that only contain the necessary classes and relations to resolve all detectable incoherences. The paper presents also an alignment repair algorithm that uses a global repair strategy to minimize both the degree of incoherence and the number of mappings removed from the alignment, while overcoming the scalability problem by employing the proposed modularization technique. Our evaluation shows that our modularization technique produces significantly small fragments of the ontologies and that our repair algorithm produces more complete alignments than other current alignment repair systems, while obtaining an equivalent degree of incoherence. Additionally, we also present a variant of our repair algorithm that makes use of the confidence values of the mappings to improve alignment repair. Our repair algorithm was implemented as part of AgreementMakerLight, a free and open-source ontology matching system. PMID:26710335

  9. Assembly, physics, and application of highly electronic-type purified semiconducting carbon nanotubes in aligned array field effect transistors and photovoltaics

    NASA Astrophysics Data System (ADS)

    Arnold, Michael

    2015-03-01

    Recent advances in (1) achieving highly monodisperse semiconducting carbon nanotubes without problematic metallic nanotubes and (2) depositing these nanotubes into useful, organized arrays and assemblies on substrates have created new opportunities for studying the physics of these one-dimensional conductors and for applying them in electronics and photonics technologies. In this talk, I will present on two topics that are along these lines. In the first, we have pioneered a scalable approach for depositing aligned arrays of ultrahigh purity semiconducting SWCNTs (prepared using polyfluorene-derivatives) called floating evaporative self-assembly (FESA). FESA is exploited to create FETs with exceptionally high combined on-conductance and on-off ratio of 261 μS/ μm and 2 x105, respectively, for a channel length of 240 nm. This is 1400 x greater on-off ratio than SWCNT FETs fabricated by other methods, at comparable on-conductance per width of 250 μS/ μm, and 30-100 x greater on-conductance per width, at comparable on-off ratio of 105-107. In the second, we have discovered how to efficiently harvest photons using semiconducting SWCNTs by driving the dissociation of excitons using donor/acceptor heterojunctions. The flow of energy in SWCNT films occurs across a complex energy landscape, temporally resolved using two-dimensional white light ultrafast spectroscopy. We have demonstrated simple solar cells driven by SWCNT excitons, based on bilayers between C60 and ultrathin (5 nm) films of SWCNTs that achieve a 1% solar power conversion efficiency (7% at the bandgap). High internal quantum efficiency indicates that future blended or multijunction cells exploiting multiple layers will be many times more efficient.

  10. Alignment of the MINOS FD

    SciTech Connect

    Becker, B.; Boehnlein, D.; /Fermilab

    2004-11-01

    The results and procedure of the alignment of the MINOS Far Detector are presented. The far detector has independent alignments of SM1 and SM2. The misalignments have an estimated uncertainty of {approx}850 {micro}m for SM1 and {approx}750 {micro}m for SM2. The alignment has as inputs the average rotations of U and V as determined by optical survey and strip positions within modules measured from the module mapper. The output of this is a module-module correction for transverse mis-alignments. These results were verified by examining an independent set of data. These alignment constants on average contribute much less then 1% to the total uncertainty in the transverse strip position.

  11. OBSERVATIONS OF ENHANCED RADIATIVE GRAIN ALIGNMENT NEAR HD 97300

    SciTech Connect

    Andersson, B-G; Potter, S. B. E-mail: sbp@saao.ac.z

    2010-09-10

    We have obtained optical multi-band polarimetry toward sightlines through the Chamaeleon I cloud, particularly in the vicinity of the young B9/A0 star HD 97300. We show, in agreement with earlier studies, that the radiation field impinging on the cloud in the projected vicinity of the star is dominated by the flux from the star, as evidenced by a local enhancement in the grain heating. By comparing the differential grain heating with the differential change in the location of the peak of the polarization curve, we show that the grain alignment is enhanced by the increase in the radiation field. We also find a weak, but measurable, variation in the grain alignment with the relative angle between the radiation field anisotropy and the magnetic field direction. Such an anisotropy in the grain alignment is consistent with a unique prediction of modern radiative alignment torque theory and provides direct support for radiatively driven grain alignment.

  12. Image Correlation Method for DNA Sequence Alignment

    PubMed Central

    Curilem Saldías, Millaray; Villarroel Sassarini, Felipe; Muñoz Poblete, Carlos; Vargas Vásquez, Asticio; Maureira Butler, Iván

    2012-01-01

    The complexity of searches and the volume of genomic data make sequence alignment one of bioinformatics most active research areas. New alignment approaches have incorporated digital signal processing techniques. Among these, correlation methods are highly sensitive. This paper proposes a novel sequence alignment method based on 2-dimensional images, where each nucleic acid base is represented as a fixed gray intensity pixel. Query and known database sequences are coded to their pixel representation and sequence alignment is handled as object recognition in a scene problem. Query and database become object and scene, respectively. An image correlation process is carried out in order to search for the best match between them. Given that this procedure can be implemented in an optical correlator, the correlation could eventually be accomplished at light speed. This paper shows an initial research stage where results were “digitally” obtained by simulating an optical correlation of DNA sequences represented as images. A total of 303 queries (variable lengths from 50 to 4500 base pairs) and 100 scenes represented by 100 x 100 images each (in total, one million base pair database) were considered for the image correlation analysis. The results showed that correlations reached very high sensitivity (99.01%), specificity (98.99%) and outperformed BLAST when mutation numbers increased. However, digital correlation processes were hundred times slower than BLAST. We are currently starting an initiative to evaluate the correlation speed process of a real experimental optical correlator. By doing this, we expect to fully exploit optical correlation light properties. As the optical correlator works jointly with the computer, digital algorithms should also be optimized. The results presented in this paper are encouraging and support the study of image correlation methods on sequence alignment. PMID:22761742

  13. Image correlation method for DNA sequence alignment.

    PubMed

    Curilem Saldías, Millaray; Villarroel Sassarini, Felipe; Muñoz Poblete, Carlos; Vargas Vásquez, Asticio; Maureira Butler, Iván

    2012-01-01

    The complexity of searches and the volume of genomic data make sequence alignment one of bioinformatics most active research areas. New alignment approaches have incorporated digital signal processing techniques. Among these, correlation methods are highly sensitive. This paper proposes a novel sequence alignment method based on 2-dimensional images, where each nucleic acid base is represented as a fixed gray intensity pixel. Query and known database sequences are coded to their pixel representation and sequence alignment is handled as object recognition in a scene problem. Query and database become object and scene, respectively. An image correlation process is carried out in order to search for the best match between them. Given that this procedure can be implemented in an optical correlator, the correlation could eventually be accomplished at light speed. This paper shows an initial research stage where results were "digitally" obtained by simulating an optical correlation of DNA sequences represented as images. A total of 303 queries (variable lengths from 50 to 4500 base pairs) and 100 scenes represented by 100 x 100 images each (in total, one million base pair database) were considered for the image correlation analysis. The results showed that correlations reached very high sensitivity (99.01%), specificity (98.99%) and outperformed BLAST when mutation numbers increased. However, digital correlation processes were hundred times slower than BLAST. We are currently starting an initiative to evaluate the correlation speed process of a real experimental optical correlator. By doing this, we expect to fully exploit optical correlation light properties. As the optical correlator works jointly with the computer, digital algorithms should also be optimized. The results presented in this paper are encouraging and support the study of image correlation methods on sequence alignment.

  14. Aligning for Innovation - Alignment Strategy to Drive Innovation

    NASA Technical Reports Server (NTRS)

    Johnson, Hurel; Teltschik, David; Bussey, Horace, Jr.; Moy, James

    2010-01-01

    With the sudden need for innovation that will help the country achieve its long-term space exploration objectives, the question of whether NASA is aligned effectively to drive the innovation that it so desperately needs to take space exploration to the next level should be entertained. Authors such as Robert Kaplan and David North have noted that companies that use a formal system for implementing strategy consistently outperform their peers. They have outlined a six-stage management systems model for implementing strategy, which includes the aligning of the organization towards its objectives. This involves the alignment of the organization from the top down. This presentation will explore the impacts of existing U.S. industrial policy on technological innovation; assess the current NASA organizational alignment and its impacts on driving technological innovation; and finally suggest an alternative approach that may drive the innovation needed to take the world to the next level of space exploration, with NASA truly leading the way.

  15. Aligned genomic data compression via improved modeling.

    PubMed

    Ochoa, Idoia; Hernaez, Mikel; Weissman, Tsachy

    2014-12-01

    With the release of the latest Next-Generation Sequencing (NGS) machine, the HiSeq X by Illumina, the cost of sequencing the whole genome of a human is expected to drop to a mere $1000. This milestone in sequencing history marks the era of affordable sequencing of individuals and opens the doors to personalized medicine. In accord, unprecedented volumes of genomic data will require storage for processing. There will be dire need not only of compressing aligned data, but also of generating compressed files that can be fed directly to downstream applications to facilitate the analysis of and inference on the data. Several approaches to this challenge have been proposed in the literature; however, focus thus far has been on the low coverage regime and most of the suggested compressors are not based on effective modeling of the data. We demonstrate the benefit of data modeling for compressing aligned reads. Specifically, we show that, by working with data models designed for the aligned data, we can improve considerably over the best compression ratio achieved by previously proposed algorithms. Our results indicate that the pareto-optimal barrier for compression rate and speed claimed by Bonfield and Mahoney (2013) [Bonfield JK and Mahoneys MV, Compression of FASTQ and SAM format sequencing data, PLOS ONE, 8(3):e59190, 2013.] does not apply for high coverage aligned data. Furthermore, our improved compression ratio is achieved by splitting the data in a manner conducive to operations in the compressed domain by downstream applications.

  16. Fusion bonding and alignment fixture

    DOEpatents

    Ackler, Harold D.; Swierkowski, Stefan P.; Tarte, Lisa A.; Hicks, Randall K.

    2000-01-01

    An improved vacuum fusion bonding structure and process for aligned bonding of large area glass plates, patterned with microchannels and access holes and slots, for elevated glass fusion temperatures. Vacuum pumpout of all the components is through the bottom platform which yields an untouched, defect free top surface which greatly improves optical access through this smooth surface. Also, a completely non-adherent interlayer, such as graphite, with alignment and location features is located between the main steel platform and the glass plate pair, which makes large improvements in quality, yield, and ease of use, and enables aligned bonding of very large glass structures.

  17. Automatic alignment of double optical paths in excimer laser amplifier

    NASA Astrophysics Data System (ADS)

    Wang, Dahui; Zhao, Xueqing; Hua, Hengqi; Zhang, Yongsheng; Hu, Yun; Yi, Aiping; Zhao, Jun

    2013-05-01

    A kind of beam automatic alignment method used for double paths amplification in the electron pumped excimer laser system is demonstrated. In this way, the beams from the amplifiers can be transferred along the designated direction and accordingly irradiate on the target with high stabilization and accuracy. However, owing to nonexistence of natural alignment references in excimer laser amplifiers, two cross-hairs structure is used to align the beams. Here, one crosshair put into the input beam is regarded as the near-field reference while the other put into output beam is regarded as the far-field reference. The two cross-hairs are transmitted onto Charge Coupled Devices (CCD) by image-relaying structures separately. The errors between intersection points of two cross-talk images and centroid coordinates of actual beam are recorded automatically and sent to closed loop feedback control mechanism. Negative feedback keeps running until preset accuracy is reached. On the basis of above-mentioned design, the alignment optical path is built and the software is compiled, whereafter the experiment of double paths automatic alignment in electron pumped excimer laser amplifier is carried through. Meanwhile, the related influencing factors and the alignment precision are analyzed. Experimental results indicate that the alignment system can achieve the aiming direction of automatic aligning beams in short time. The analysis shows that the accuracy of alignment system is 0.63μrad and the beam maximum restoration error is 13.75μm. Furthermore, the bigger distance between the two cross-hairs, the higher precision of the system is. Therefore, the automatic alignment system has been used in angular multiplexing excimer Main Oscillation Power Amplification (MOPA) system and can satisfy the requirement of beam alignment precision on the whole.

  18. Laser beam alignment apparatus and method

    DOEpatents

    Gruhn, C.R.; Hammond, R.B.

    The disclosure related to an apparatus and method for laser beam alignment. Thermoelectric properties of a disc in a laser beam path are used to provide an indication of beam alignment and/or automatic laser alignment.

  19. Laser beam alignment apparatus and method

    DOEpatents

    Gruhn, Charles R.; Hammond, Robert B.

    1981-01-01

    The disclosure relates to an apparatus and method for laser beam alignment. Thermoelectric properties of a disc in a laser beam path are used to provide an indication of beam alignment and/or automatic laser alignment.

  20. Theory of grain alignment in molecular clouds

    NASA Technical Reports Server (NTRS)

    Roberge, Wayne G.

    1993-01-01

    Research accomplishments are presented and include the following: (1) mathematical theory of grain alignment; (2) super-paramagnetic alignment of molecular cloud grains; and (3) theory of grain alignment by ambipolar diffusion.

  1. Field-free alignment in repetitively kicked nitrogen gas

    SciTech Connect

    Cryan, James P.; Bucksbaum, Philip H.; Coffee, Ryan N.

    2009-12-15

    We demonstrate a high level of laser-induced transient alignment in room temperature and density N{sub 2} with a technique that avoids laser field ionization. Our measured alignment shows an improvement over previous one-pulse or two-pulse experimental alignment results and approaches the theoretical maximum value. We employ eight equally spaced ultrafast laser pulses with a separation that takes advantage of the periodic revivals for the ensemble of quantum rotors. Each successive pulse increases the transient alignment [(t)] and also moves the rotational population away from thermal equilibrium. These measurements are combined with simulations to determine the value of , the J-state distributions, and the functional dependencies of the alignment features.

  2. Fixture for aligning motor assembly

    SciTech Connect

    Shervington, Roger M.; Vaghani, Vallabh V.; Vanek, Laurence D.; Christensen, Scott A.

    2009-12-08

    An alignment fixture includes a rotor fixture, a stator fixture and a sensor system which measures a rotational displacement therebetween. The fixture precisely measures rotation of a generator stator assembly away from a NULL position referenced by a unique reference spline on the rotor shaft. By providing an adjustable location of the stator assembly within the housing, the magnetic axes within each generator shall be aligned to a predetermined and controlled tolerance between the generator interface mounting pin and the reference spline on the rotor shaft. Once magnetically aligned, each generator is essentially a line replaceable unit which may be readily mounted to any input of a multi-generator gearbox assembly with the assurance that the magnetic alignment will be within a predetermined tolerance.

  3. Stellar Alignments - Identification and Analysis

    NASA Astrophysics Data System (ADS)

    Ruggles, Clive L. N.

    Fortuitous stellar alignments can be fitted to structural orientations with relative ease by the unwary. Nonetheless, cautious approaches taking into account a broader range of cultural evidence, as well as paying due attention to potential methodological pitfalls, have been successful in identifying credible stellar alignments—and constructing plausible assessments of their cultural significance—in a variety of circumstances. These range from single instances of alignments upon particular asterisms where the corroborating historical or ethnographic evidence is strong to repeated instances of oriented structures with only limited independent cultural information but where systematic, data-driven approaches can be productive. In the majority of cases, the identification and interpretation of putative stellar alignments relates to groups of similar monuments or complex single sites and involves a balance between systematic studies of the alignments themselves, backed up by statistical analysis where appropriate, and the consideration of a range of contextual evidence, either derived from the archaeological record alone or from other relevant sources.

  4. RF Jitter Modulation Alignment Sensing

    NASA Astrophysics Data System (ADS)

    Ortega, L. F.; Fulda, P.; Diaz-Ortiz, M.; Perez Sanchez, G.; Ciani, G.; Voss, D.; Mueller, G.; Tanner, D. B.

    2017-01-01

    We will present the numerical and experimental results of a new alignment sensing scheme which can reduce the complexity of alignment sensing systems currently used, while maintaining the same shot noise limited sensitivity. This scheme relies on the ability of electro-optic beam deflectors to create angular modulation sidebands in radio frequency, and needs only a single-element photodiode and IQ demodulation to generate error signals for tilt and translation degrees of freedom in one dimension. It distances itself from current techniques by eliminating the need for beam centering servo systems, quadrant photodetectors and Gouy phase telescopes. RF Jitter alignment sensing can be used to reduce the complexity in the alignment systems of many laser optical experiments, including LIGO and the ALPS experiment.

  5. The Alignment effect of brightest cluster galaxies in the SDSS

    SciTech Connect

    Kim, R. S. J.; Annis, J.; Strauss, M. A.; Lupton, R. H.; Bahcall, N. A.; Gunn, J. E.; Kepner, J. V.; Postman, M.

    2001-10-01

    One of the most vital observational clues for unraveling the origin of Brightest Cluster Galaxies (BCG) is the observed alignment of the BCGs with their host cluster and its surroundings. We have examined the BCG-cluster alignment effect, using clusters of galaxies detected from the Sloan Digital Sky Survey (SDSS). We find that the BCGs are preferentially aligned with the principal axis of their hosts, to a much higher redshift (z >~ 0.3) than probed by previous studies (z <~ 0.1). The alignment effect strongly depends on the magnitude difference of the BCG and the second and third brightest cluster members: we find a strong alignment effect for the dominant BCGs, while less dominant BCGs do not show any departure from random alignment with respect to the cluster. We therefore claim that the alignment process originates from the same process that makes the BCG grow dominant, be it direct mergers in the early stage of cluster formation, or a later process that resembles the galactic cannibalism scenario. We do not find strong evidence for (or against) redshift evolution between 0alignment with redshift, richness and morphology of both the cluster and the BCG.

  6. Explaining compact groups as change alignments

    NASA Technical Reports Server (NTRS)

    Mamon, Gary A.

    1990-01-01

    The physical nature of the apparently densest groups of galaxies, known as compact groups is a topic of some recent controversy, despite the detailed observations of a well-defined catalog of 100 isolated compact groups compiled by Hickson (1982). Whereas many authors have espoused the view that compact groups are bound systems, typically as dense as they appear in projection on the sky (e.g., Williams & Rood 1987; Sulentic 1987; Hickson & Rood 1988), others see them as the result of chance configurations within larger systems, either in 1D (chance alignments: Mamon 1986; Walke & Mamon 1989), or in 3D (transient cores: Rose 1979). As outlined in the companion review to this contribution (Mamon, in these proceedings), the implication of Hickson's compact groups (HCGs) being dense bound systems is that they would then constitute the densest isolated systems of galaxies in the Universe and the privileged site for galaxy interactions. In a previous paper (Mamon 1986), the author reviewed the arguments given for the different theories of compact groups. Since then, a dozen papers have been published on the subject, including a thorough and perceptive review by White (1990), thus more than doubling the amount written on the subject. Here, the author first enumerates the arguments that he brought up in 1986 substantiating the chance alignment hypothesis, then he reviews the current status of the numerous recent arguments arguing against chance alignments and/or for the bound dense group hypothesis (both for the majority of HCGs but not all of them), and finally he reconsiders each one of these anti-chance alignment arguments and shows that, rather than being discredited, the chance alignment hypothesis remains a fully consistent explanation for the nature of compact groups.

  7. Robust Nonnegative Patch Alignment for Dimensionality Reduction.

    PubMed

    You, Xinge; Ou, Weihua; Chen, Chun Lung Philip; Li, Qiang; Zhu, Ziqi; Tang, Yuanyan

    2015-11-01

    Dimensionality reduction is an important method to analyze high-dimensional data and has many applications in pattern recognition and computer vision. In this paper, we propose a robust nonnegative patch alignment for dimensionality reduction, which includes a reconstruction error term and a whole alignment term. We use correntropy-induced metric to measure the reconstruction error, in which the weight is learned adaptively for each entry. For the whole alignment, we propose locality-preserving robust nonnegative patch alignment (LP-RNA) and sparsity-preserviing robust nonnegative patch alignment (SP-RNA), which are unsupervised and supervised, respectively. In the LP-RNA, we propose a locally sparse graph to encode the local geometric structure of the manifold embedded in high-dimensional space. In particular, we select large p -nearest neighbors for each sample, then obtain the sparse representation with respect to these neighbors. The sparse representation is used to build a graph, which simultaneously enjoys locality, sparseness, and robustness. In the SP-RNA, we simultaneously use local geometric structure and discriminative information, in which the sparse reconstruction coefficient is used to characterize the local geometric structure and weighted distance is used to measure the separability of different classes. For the induced nonconvex objective function, we formulate it into a weighted nonnegative matrix factorization based on half-quadratic optimization. We propose a multiplicative update rule to solve this function and show that the objective function converges to a local optimum. Several experimental results on synthetic and real data sets demonstrate that the learned representation is more discriminative and robust than most existing dimensionality reduction methods.

  8. Isolated digit recognition without time alignment

    NASA Astrophysics Data System (ADS)

    Gay, Jeffrey Mark

    1994-12-01

    This thesis examines methods for isolated digit recognition without using time alignment. Resource requirements for isolated word recognizers that use time alignment can become prohibitively large as the vocabulary to be classified grows. Thus, methods capable of achieving recognition rates comparable to those obtained with current methods using these techniques are needed. The goals of this research are to find feature sets for speech recognition that perform well without using time alignment, and to identify classifiers that provide good performance with these features. Using the digits from the TI46 database, baseline speaker-independent recognition rates of 95.2% for the complete speaker set and 98.1% for the male speaker set are established using dynamic time warping (DTW). This work begins with features derived from spectrograms of each digit. Based on a critical band frequency scale covering the telephone bandwidth (300-3000 Hz), these critical band energy features are classified alone and in combination with several other feature sets, with several different classifiers. With this method, there is one 'short' feature vector per word. For speaker-independent recognition using the complete speaker set and a multi-layer perceptron (MLP) classifier, a recognition rate of 92.4% is achieved. For the same classifier with the male speaker set, a recognition rate of 97.1% is achieved. For the male speaker set, there is no statistical difference between results using DTW, and those using the MLP and no time alignment. This shows that there are feature sets that may provide high recognition rates for isolated word recognition without the need for time alignment.

  9. Well-pump alignment system

    DOEpatents

    Drumheller, D.S.

    1998-10-20

    An improved well-pump for geothermal wells, an alignment system for a well-pump, and to a method for aligning a rotor and stator within a well-pump are disclosed, wherein the well-pump has a whistle assembly formed at a bottom portion thereof, such that variations in the frequency of the whistle, indicating misalignment, may be monitored during pumping. 6 figs.

  10. The Rigors of Aligning Performance

    DTIC Science & Technology

    2015-06-01

    bearing in mind customer perceptions. Recommendations include employee training centered on goal alignment, which is vital to highlight the...appeared to be lacking in some areas when bearing in mind customer perceptions. Recommendations include employee training centered on goal alignment...through the strategic plan and CONOPS. However, the extent of goal accomplishment appears to be lacking in some areas when bearing in mind the

  11. On the Efficiency of Grain Alignment in Dark Clouds

    NASA Astrophysics Data System (ADS)

    Lazarian, A.; Goodman, Alyssa A.; Myers, Philip C.

    1997-11-01

    A quantitative analysis of grain alignment in the filamentary dark cloud L1755 in Ophiuchus is presented. We show that the observed decrease of the polarization-to-extinction ratio for the inner parts of this quiescent dark cloud can be explained as a result of the decrease of the efficiency of grain alignment. We make quantitative estimates of grain alignment efficiency for six mechanisms involving grains with either thermal or suprathermal rotation, interacting with either magnetic field or gaseous flow. We also make semiquantitative estimates of grain alignment by radiative torques. We show that in conditions typical of dark cloud interiors, all known major mechanisms of grain alignment fail. All the studied mechanisms predict polarization at least an order of magnitude below the currently detectable levels of ~1%. On the contrary, in the dark cloud environments where Av < 1, the grain alignment can be much more efficient. There the alignment of suprathermally rotating grains with superparamagnetic inclusions, and possibly also radiative torques, account for observed polarization. These results apply to L1755, which we model in detail, and probably also to B216 and other similar dark clouds. Our study suggests an explanation for the difference in results obtained through polarimetry of background starlight and polarized thermal emission from the dust itself. We conjecture that the emission polarimetry selectively reveals aligned grains in the environment far from thermodynamic equilibrium, as opposed to starlight polarization studies that probe the alignment of grains all the way along the line of sight, including the interiors of dark quiescent clouds, where no alignment is possible. We dedicate this paper to the memory of Edward M. Purcell and Lyman Spitzer, Jr., two pioneers in the quantitative study of the interstellar medium.

  12. Binocular collimation vs conditional alignment

    NASA Astrophysics Data System (ADS)

    Cook, William J.

    2012-10-01

    As binocular enthusiasts share their passion, topics related to collimation abound. Typically, we find how observers, armed only with a jeweler's screwdriver, can "perfectly collimate" his or her binocular, make it "spot on," or other verbiage of similar connotation. Unfortunately, what most are addressing is a form of pseudo-collimation I have referred to since the mid-1970s as "Conditional Alignment." Ignoring the importance of the mechanical axis (hinge) in the alignment process, this "condition," while having the potential to make alignment serviceable, or even outstanding—within a small range of IPD (Interpupillary Distance) settings relative to the user's spatial accommodation (the ability to accept small errors in parallelism of the optical axes)—may take the instrument farther from the 3-axis collimation conscientious manufacturers seek to implement. Becoming more optically savvy—and especially with so many mechanically inferior binoculars entering the marketplace— the consumer contemplating self-repair and alignment has a need to understand the difference between clinical, 3-axis "collimation" (meaning both optical axes are parallel with the axis of the hinge) and "conditional alignment," as differentiated in this paper. Furthermore, I believe there has been a long-standing need for the term "Conditional Alignment," or some equivalent, to be accepted as part of the vernacular of those who use binoculars extensively, whether for professional or recreational activities. Achieving that acceptance is the aim of this paper.

  13. Rapid protein alignment in the cloud: HAMOND combines fast DIAMOND alignments with Hadoop parallelism.

    PubMed

    Yu, Jia; Blom, Jochen; Sczyrba, Alexander; Goesmann, Alexander

    2017-02-21

    The introduction of next generation sequencing has caused a steady increase in the amounts of data that have to be processed in modern life science. Sequence alignment plays a key role in the analysis of sequencing data e.g. within whole genome sequencing or metagenome projects. BLAST is a commonly used alignment tool that was the standard approach for more than two decades, but in the last years faster alternatives have been proposed including RapSearch, GHOSTX, and DIAMOND. Here we introduce HAMOND, an application that uses Apache Hadoop to parallelize DIAMOND computation in order to scale-out the calculation of alignments. HAMOND is fault tolerant and scalable by utilizing large cloud computing infrastructures like Amazon Web Services. HAMOND has been tested in comparative genomics analyses and showed promising results both in efficiency and accuracy.

  14. Alignment of Iron Nanoparticles in a Magnetic Field Due to Shape Anisotropy

    SciTech Connect

    Radhakrishnan, Balasubramaniam; Nicholson, Don M; Eisenbach, Markus; Ludtka, Gerard Michael; Rios, Orlando; Parish, Chad M

    2015-07-09

    During high magnetic field processing there is evidence for alignment of non-spherical metallic particles above the Curie temperature in alloys with negligible magneto-crystalline anisotropy. The main driving force for alignment is the magnetic shape anisotropy. Current understanding of the phenomenon is not adequate to quantify the effect of particle size, aspect ratio, temperature and the magnetic field on particle alignment. We demonstrate a Monte Carlo approach coupled with size scaling to show the conditions under which alignment is possible.

  15. Uniformly spaced field-aligned ionization ducts

    NASA Technical Reports Server (NTRS)

    Gross, S. H.; Muldrew, D. B.

    1984-01-01

    A number of interesting cases of combination mode ducted echoes for mid- and low-latitude regions are presented that show nearly uniformly spaced multiple combination mode traces on the ionograms in the frequency range above 1 MHz. These traces suggest that a parallel system of field-aligned ducts is present. Ray tracing studies are made to determine the structure that would explain the observations using the electron density profile derivable from the vertical trace and assuming field-aligned ducts. Spacing perpendicular to the ducts is found to be as much as 70 km. Some of these parallel duct structures are found to extend to the conjugate hemisphere, possibly to the F peak.

  16. Camber Angle Inspection for Vehicle Wheel Alignments

    PubMed Central

    Young, Jieh-Shian; Hsu, Hong-Yi; Chuang, Chih-Yuan

    2017-01-01

    This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU)-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x-axis or z-axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ±0.015∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi. PMID:28165365

  17. Camber Angle Inspection for Vehicle Wheel Alignments.

    PubMed

    Young, Jieh-Shian; Hsu, Hong-Yi; Chuang, Chih-Yuan

    2017-02-03

    This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU)-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x-axis or z-axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ± 0.015 ∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi.

  18. FlexSnap: Flexible Non-sequential Protein Structure Alignment

    NASA Astrophysics Data System (ADS)

    Salem, Saeed; Zaki, Mohammed J.; Bystroff, Chris

    Proteins have evolved subject to energetic selection pressure for stability and flexibility. Structural similarity between proteins which have gone through conformational changes can be captured effectively if flexibility is considered. Topologically unrelated proteins that preserve secondary structure packing interactions can be detected if both flexibility and sequence permutations are considered. We propose the FlexSnap algorithm for flexible non-topological protein structural alignment. The effectiveness of FlexSnap is demonstrated by measuring the agreement of its alignments with manually curated non-sequential structural alignments. FlexSnap showed competitive results against state-of-the-art algorithms, like DALI, SARF2, MultiProt, FlexProt, and FATCAT.

  19. A Nonlinear Observer for Gyro Alignment Estimation

    NASA Technical Reports Server (NTRS)

    Thienel, J.; Sanner, R. M.

    2003-01-01

    A nonlinear observer for gyro alignment estimation is presented. The observer is composed of two error terms, an attitude error and an alignment error. The observer is globally stable with exponential convergence of the attitude errors. The gyro alignment estimate converges to the true alignment when the system is completely observable.

  20. PASTA: Ultra-Large Multiple Sequence Alignment for Nucleotide and Amino-Acid Sequences.

    PubMed

    Mirarab, Siavash; Nguyen, Nam; Guo, Sheng; Wang, Li-San; Kim, Junhyong; Warnow, Tandy

    2015-05-01

    We introduce PASTA, a new multiple sequence alignment algorithm. PASTA uses a new technique to produce an alignment given a guide tree that enables it to be both highly scalable and very accurate. We present a study on biological and simulated data with up to 200,000 sequences, showing that PASTA produces highly accurate alignments, improving on the accuracy and scalability of the leading alignment methods (including SATé). We also show that trees estimated on PASTA alignments are highly accurate--slightly better than SATé trees, but with substantial improvements relative to other methods. Finally, PASTA is faster than SATé, highly parallelizable, and requires relatively little memory.

  1. Television Quiz Show Simulation

    ERIC Educational Resources Information Center

    Hill, Jonnie Lynn

    2007-01-01

    This article explores the simulation of four television quiz shows for students in China studying English as a foreign language (EFL). It discusses the adaptation and implementation of television quiz shows and how the students reacted to them.

  2. Alignment method for parabolic trough solar concentrators

    DOEpatents

    Diver, Richard B.

    2010-02-23

    A Theoretical Overlay Photographic (TOP) alignment method uses the overlay of a theoretical projected image of a perfectly aligned concentrator on a photographic image of the concentrator to align the mirror facets of a parabolic trough solar concentrator. The alignment method is practical and straightforward, and inherently aligns the mirror facets to the receiver. When integrated with clinometer measurements for which gravity and mechanical drag effects have been accounted for and which are made in a manner and location consistent with the alignment method, all of the mirrors on a common drive can be aligned and optimized for any concentrator orientation.

  3. An introduction to the Lagan alignment toolkit.

    PubMed

    Brudno, Michael

    2007-01-01

    The Lagan Toolkit is a software package for comparison of genomic sequences. It includes the CHAOS local alignment program, LAGAN global alignment program for two, or more sequences and Shuffle-LAGAN, a "glocal" alignment method that handles genomic rearrangements in a global alignment framework. The alignment programs included in the Lagan Toolkit have been widely used to compare genomes of many organisms, from bacteria to large mammalian genomes. This chapter provides an overview of the algorithms used by the LAGAN programs to construct genomic alignments, explains how to build alignments using either the standalone program or the web server, and discusses some of the common pitfalls users encounter when using the toolkit.

  4. Combining Multiple Pairwise Structure-based Alignments

    SciTech Connect

    2014-11-12

    CombAlign is a new Python code that generates a gapped, one-to-many, multiple structure-based sequence alignment(MSSA) given a set of pairwise structure-based alignments. In order to better define regions of similarity among related protein structures, it is useful to detect the residue-residue correspondences among a set of pairwise structure alignments. Few codes exist for constructing a one-to-many, multiple sequence alignment derived from a set of structure alignments, and we perceived a need for creating a new tool for combing pairwise structure alignments that would allow for insertion of gaps in the reference structure.

  5. Multiple sequence alignment with hierarchical clustering.

    PubMed Central

    Corpet, F

    1988-01-01

    An algorithm is presented for the multiple alignment of sequences, either proteins or nucleic acids, that is both accurate and easy to use on microcomputers. The approach is based on the conventional dynamic-programming method of pairwise alignment. Initially, a hierarchical clustering of the sequences is performed using the matrix of the pairwise alignment scores. The closest sequences are aligned creating groups of aligned sequences. Then close groups are aligned until all sequences are aligned in one group. The pairwise alignments included in the multiple alignment form a new matrix that is used to produce a hierarchical clustering. If it is different from the first one, iteration of the process can be performed. The method is illustrated by an example: a global alignment of 39 sequences of cytochrome c. PMID:2849754

  6. Alignment Tool For Inertia Welding

    NASA Technical Reports Server (NTRS)

    Snyder, Gary L.

    1991-01-01

    Compact, easy-to-use tool aligns drive bar of inertia welder over hole in stub. Ensures drive bar concentric to hole within 0.002 in. (0.051 mm.). Holds two batteries and light bulb. Electrical circuit completed, providing current to bulb when pin in contact with post. When pin centered in post hole, it does not touch post, and lamp turns off. Built for use in making repair welds on liquid-oxygen-injector posts in Space Shuttle main engine. Version having suitably modified dimensions used to facilitate alignment in other forests of post.

  7. XUV ionization of aligned molecules

    SciTech Connect

    Kelkensberg, F.; Siu, W.; Gademann, G.; Rouzee, A.; Vrakking, M. J. J.; Johnsson, P.; Lucchini, M.; Lucchese, R. R.

    2011-11-15

    New extreme-ultraviolet (XUV) light sources such as high-order-harmonic generation (HHG) and free-electron lasers (FELs), combined with laser-induced alignment techniques, enable novel methods for making molecular movies based on measuring molecular frame photoelectron angular distributions. Experiments are presented where CO{sub 2} molecules were impulsively aligned using a near-infrared laser and ionized using femtosecond XUV pulses obtained by HHG. Measured electron angular distributions reveal contributions from four orbitals and the onset of the influence of the molecular structure.

  8. Measurements of magnetic field alignment

    SciTech Connect

    Kuchnir, M.; Schmidt, E.E.

    1987-11-06

    The procedure for installing Superconducting Super Collider (SSC) dipoles in their respective cryostats involves aligning the average direction of their field with the vertical to an accuracy of 0.5 mrad. The equipment developed for carrying on these measurements is described and the measurements performed on the first few prototypes SSC magnets are presented. The field angle as a function of position in these 16.6 m long magnets is a characteristic of the individual magnet with possible feedback information to its manufacturing procedure. A comparison of this vertical alignment characteristic with a magnetic field intensity (by NMR) characteristic for one of the prototypes is also presented. 5 refs., 7 figs.

  9. MANGO: a new approach to multiple sequence alignment.

    PubMed

    Zhang, Zefeng; Lin, Hao; Li, Ming

    2007-01-01

    Multiple sequence alignment is a classical and challenging task for biological sequence analysis. The problem is NP-hard. The full dynamic programming takes too much time. The progressive alignment heuristics adopted by most state of the art multiple sequence alignment programs suffer from the 'once a gap, always a gap' phenomenon. Is there a radically new way to do multiple sequence alignment? This paper introduces a novel and orthogonal multiple sequence alignment method, using multiple optimized spaced seeds and new algorithms to handle these seeds efficiently. Our new algorithm processes information of all sequences as a whole, avoiding problems caused by the popular progressive approaches. Because the optimized spaced seeds are provably significantly more sensitive than the consecutive k-mers, the new approach promises to be more accurate and reliable. To validate our new approach, we have implemented MANGO: Multiple Alignment with N Gapped Oligos. Experiments were carried out on large 16S RNA benchmarks showing that MANGO compares favorably, in both accuracy and speed, against state-of-art multiple sequence alignment methods, including ClustalW 1.83, MUSCLE 3.6, MAFFT 5.861, Prob-ConsRNA 1.11, Dialign 2.2.1, DIALIGN-T 0.2.1, T-Coffee 4.85, POA 2.0 and Kalign 2.0.

  10. Accurate multiple network alignment through context-sensitive random walk

    PubMed Central

    2015-01-01

    Background Comparative network analysis can provide an effective means of analyzing large-scale biological networks and gaining novel insights into their structure and organization. Global network alignment aims to predict the best overall mapping between a given set of biological networks, thereby identifying important similarities as well as differences among the networks. It has been shown that network alignment methods can be used to detect pathways or network modules that are conserved across different networks. Until now, a number of network alignment algorithms have been proposed based on different formulations and approaches, many of them focusing on pairwise alignment. Results In this work, we propose a novel multiple network alignment algorithm based on a context-sensitive random walk model. The random walker employed in the proposed algorithm switches between two different modes, namely, an individual walk on a single network and a simultaneous walk on two networks. The switching decision is made in a context-sensitive manner by examining the current neighborhood, which is effective for quantitatively estimating the degree of correspondence between nodes that belong to different networks, in a manner that sensibly integrates node similarity and topological similarity. The resulting node correspondence scores are then used to predict the maximum expected accuracy (MEA) alignment of the given networks. Conclusions Performance evaluation based on synthetic networks as well as real protein-protein interaction networks shows that the proposed algorithm can construct more accurate multiple network alignments compared to other leading methods. PMID:25707987

  11. Modeling of Field-Aligned Guided Echoes in the Plasmasphere

    NASA Technical Reports Server (NTRS)

    Fung, Shing F.; Green, James L.

    2004-01-01

    The conditions under which high frequency (f>>f(sub uh)) long-range extraordinary-mode discrete field-aligned echoes observed by the Radio Plasma Imager (RPI) on board the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) satellite in the plasmasphere are investigated by ray tracing modeling. Field-aligned discrete echoes are most commonly observed by RPI in the plasmasphere although they are also observed over the polar cap region. The plasmasphere field-aligned echoes appearing as multiple echo traces at different virtual ranges are attributed to signals reflected successively between conjugate hemispheres that propagate along or nearly along closed geomagnetic field lines. The ray tracing simulations show that field-aligned ducts with as little as 1% density perturbations (depletions) and less than 10 wavelengths wide can guide nearly field-aligned propagating high frequency X mode waves. Effective guidance of wave at a given frequency and wave normal angle (Psi) depends on the cross-field density scale of the duct, such that ducts with stronger density depletions need to be wider in order to maintain the same gradient of refractive index across the magnetic field. While signal guidance by field aligned density gradient without ducting is possible only over the polar region, conjugate field-aligned echoes that have traversed through the equatorial region are most likely guided by ducting.

  12. Patterned silk film scaffolds for aligned lamellar bone tissue engineering

    PubMed Central

    Tien, Lee W.; Gil, Eun Seok; Park, Sang-Hyug; Mandal, Biman B.; Kaplan, David L.

    2013-01-01

    Various porous biomaterial scaffolds have been utilized for bone tissue engineering; however, they are often limited in their ability to replicate the structural hierarchy and mechanics of native cortical bone. In this study, the alignment and osteogenic differentiation of human mesenchymal stem cells (MSCs) on patterned silk films (PF) was investigated as a bottom-up, biomimetic approach toward engineering cortical bone lamellae. Screening films cast with nine different micro and nano scale groove patterns showed that cellular alignment was mediated by an interplay between the width and depth of the patterns. MSCs were differentiated in osteogenic medium for four weeks on the PF that induced the highest degree of alignment, while flat films (FF) served as controls. Gene expression analysis and calcium quantification indicated that the PF supported osteogenic differentiation while also inducing robust lamellar alignment of cells and matrix deposition. A secondary alignment effect was noted on the PF where a new layer of aligned cells grew over the first layer, but rotated obliquely to the underlying pattern direction and first layer orientation. This layering and rotation of the aligned MSCs resembled the characteristic structural organization observed in native lamellar bone. The ability to control multilayered lamellar structural hierarchy from the interplay between a patterned 2D surface and cells suggests intriguing options for future biomaterial scaffolds designed to mimic native tissue structures. PMID:23070941

  13. Survey, alignment, and beam stability at the Advanced Light Source

    SciTech Connect

    Krebs, G.F.

    1997-10-01

    This paper describes survey and alignment at the Lawrence Berkeley Laboratories Advanced Light Source (ALS) accelerators from 1993 to 1997. The ALS is a third generation light source requiring magnet alignment to within 150 microns. To accomplish this, a network of monuments was established and maintained. Monthly elevation surveys show the movement of the floor over time. Inclinometers have recently been employed to give real time information about magnet, vacuum tank and magnet girder motion in the ALS storage ring.

  14. Alignment of cD-galaxies with their surroundings

    NASA Technical Reports Server (NTRS)

    Vankampen, Eelco; Rhee, George

    1990-01-01

    For a sample of 122 rich Abell clusters the authors find a strong correlation of the position angle (orientation) of the first-ranked galaxy and its parent cluster. This alignment effect is strongest for cD-galaxies. Formation scenarios for cD galaxies, like the merging scenario, must produce such a strong alignment effect. The authors show some N-body simulations done for this purpose.

  15. Field aligned current observations in the polar cusp ionosphere

    NASA Technical Reports Server (NTRS)

    Ledley, B. G.; Farthing, W. H.

    1973-01-01

    Vector magnetic field measurements made during a sounding rocket flight in the polar cusp ionosphere show field fluctuations in the lower F-region which are interpreted as being caused by the payload's passage through a structured field aligned current system. The field aligned currents have a characteristic horizontal scale size of one kilometer. Analysis of one large field fluctuation gives a current density of 0.0001 amp/m sq.

  16. Regular Language Constrained Sequence Alignment Revisited

    NASA Astrophysics Data System (ADS)

    Kucherov, Gregory; Pinhas, Tamar; Ziv-Ukelson, Michal

    Imposing constraints in the form of a finite automaton or a regular expression is an effective way to incorporate additional a priori knowledge into sequence alignment procedures. With this motivation, Arslan [1] introduced the Regular Language Constrained Sequence Alignment Problem and proposed an O(n 2 t 4) time and O(n 2 t 2) space algorithm for solving it, where n is the length of the input strings and t is the number of states in the non-deterministic automaton, which is given as input. Chung et al. [2] proposed a faster O(n 2 t 3) time algorithm for the same problem. In this paper, we further speed up the algorithms for Regular Language Constrained Sequence Alignment by reducing their worst case time complexity bound to O(n 2 t 3/logt). This is done by establishing an optimal bound on the size of Straight-Line Programs solving the maxima computation subproblem of the basic dynamic programming algorithm. We also study another solution based on a Steiner Tree computation. While it does not improve the run time complexity in the worst case, our simulations show that both approaches are efficient in practice, especially when the input automata are dense.

  17. Alignment limit of the NMSSM Higgs sector

    DOE PAGES

    Carena, Marcela; Haber, Howard E.; Low, Ian; ...

    2016-02-17

    The Next-to-Minimal Supersymmetric extension of the Standard Model (NMSSM) with a Higgs boson of mass 125 GeV can be compatible with stop masses of order of the electroweak scale, thereby reducing the degree of fine-tuning necessary to achieve electroweak symmetry breaking. Moreover, in an attractive region of the NMSSM parameter space, corresponding to the \\alignment limit" in which one of the neutral Higgs fields lies approximately in the same direction in field space as the doublet Higgs vacuum expectation value, the observed Higgs boson is predicted to have Standard- Model-like properties. We derive analytical expressions for the alignment conditions andmore » show that they point toward a more natural region of parameter space for electroweak symmetry breaking, while allowing for perturbativity of the theory up to the Planck scale. Additionally, the alignment limit in the NMSSM leads to a well defined spectrum in the Higgs and Higgsino sectors, and yields a rich and interesting Higgs boson phenomenology that can be tested at the LHC. Here, we discuss the most promising channels for discovery and present several benchmark points for further study.« less

  18. Alignment limit of the NMSSM Higgs sector

    SciTech Connect

    Carena, Marcela; Haber, Howard E.; Low, Ian; Shah, Nausheen R.; Wagner, Carlos E. M.

    2016-02-17

    The Next-to-Minimal Supersymmetric extension of the Standard Model (NMSSM) with a Higgs boson of mass 125 GeV can be compatible with stop masses of order of the electroweak scale, thereby reducing the degree of fine-tuning necessary to achieve electroweak symmetry breaking. Moreover, in an attractive region of the NMSSM parameter space, corresponding to the \\alignment limit" in which one of the neutral Higgs fields lies approximately in the same direction in field space as the doublet Higgs vacuum expectation value, the observed Higgs boson is predicted to have Standard- Model-like properties. We derive analytical expressions for the alignment conditions and show that they point toward a more natural region of parameter space for electroweak symmetry breaking, while allowing for perturbativity of the theory up to the Planck scale. Additionally, the alignment limit in the NMSSM leads to a well defined spectrum in the Higgs and Higgsino sectors, and yields a rich and interesting Higgs boson phenomenology that can be tested at the LHC. Here, we discuss the most promising channels for discovery and present several benchmark points for further study.

  19. Tonal Alignment in Irish Dialects

    ERIC Educational Resources Information Center

    Dalton, Martha; Ni Chasaide, Ailbhe

    2005-01-01

    A comparison of the contour alignment of nuclear and initial prenuclear accents was carried out for the Irish dialects of Gaoth Dobhair in Ulster (GD-U) and Cois Fharraige in Connaught (CF-C). This was done across conditions where the number of unstressed syllables following the nuclear and preceding the initial prenuclear accents was varied from…

  20. Alignment in Second Language Dialogue

    ERIC Educational Resources Information Center

    Costa, Albert; Pickering, Martin; Sorace, Antonella

    2008-01-01

    This paper considers the nature of second language dialogues, involving at least one non-native (L2) speaker. We assume that dialogue is characterised by a process in which interlocutors develop similar mental states to each other (Pickering & Garrod, 2004). We first consider various means in which interlocutors align their mental states, and…

  1. Aligning Assessments for COSMA Accreditation

    ERIC Educational Resources Information Center

    Laird, Curt; Johnson, Dennis A.; Alderman, Heather

    2015-01-01

    Many higher education sport management programs are currently in the process of seeking accreditation from the Commission on Sport Management Accreditation (COSMA). This article provides a best-practice method for aligning student learning outcomes with a sport management program's mission and goals. Formative and summative assessment procedures…

  2. Progressive multiple sequence alignments from triplets

    PubMed Central

    Kruspe, Matthias; Stadler, Peter F

    2007-01-01

    Background The quality of progressive sequence alignments strongly depends on the accuracy of the individual pairwise alignment steps since gaps that are introduced at one step cannot be removed at later aggregation steps. Adjacent insertions and deletions necessarily appear in arbitrary order in pairwise alignments and hence form an unavoidable source of errors. Research Here we present a modified variant of progressive sequence alignments that addresses both issues. Instead of pairwise alignments we use exact dynamic programming to align sequence or profile triples. This avoids a large fractions of the ambiguities arising in pairwise alignments. In the subsequent aggregation steps we follow the logic of the Neighbor-Net algorithm, which constructs a phylogenetic network by step-wisely replacing triples by pairs instead of combining pairs to singletons. To this end the three-way alignments are subdivided into two partial alignments, at which stage all-gap columns are naturally removed. This alleviates the "once a gap, always a gap" problem of progressive alignment procedures. Conclusion The three-way Neighbor-Net based alignment program aln3nn is shown to compare favorably on both protein sequences and nucleic acids sequences to other progressive alignment tools. In the latter case one easily can include scoring terms that consider secondary structure features. Overall, the quality of resulting alignments in general exceeds that of clustalw or other multiple alignments tools even though our software does not included heuristics for context dependent (mis)match scores. PMID:17631683

  3. Experiments in Aligning Threaded Parts Using a Robot Hand

    NASA Technical Reports Server (NTRS)

    Diftler, M. A.; Walker, I. D.

    1999-01-01

    Techniques for determining and correcting threaded part alignment using force and angular position data are developed to augment currently limited techniques for align- ing threaded parts. These new techniques are based on backspinning a nut with respect to a bolt and measuring the force change that occurs when the bolt "falls" into the nut. Kinematic models that describe the relationship between threaded parts during backspinning are introduced and are used to show how angular alignment may be determined. The models indicate how to distinguish between the aligned and misaligned cases of a bolt and a nut connection by using axial force data only. In addition, by tracking the in-plane relative attitude of the bolt during spinning, data can be obtained on the direction of the angular misalignment which, in turn, is used to correct the misalignment. Results from experiments using a bolt held in a specialized fixture and a three fingers Stanford/JPL hand are presented.

  4. Incorporating Linguistic Information to Statistical Word-Level Alignment

    NASA Astrophysics Data System (ADS)

    Cendejas, Eduardo; Barceló, Grettel; Gelbukh, Alexander; Sidorov, Grigori

    Parallel texts are enriched by alignment algorithms, thus establishing a relationship between the structures of the implied languages. Depending on the alignment level, the enrichment can be performed on paragraphs, sentences or words, of the expressed content in the source language and its translation. There are two main approaches to perform word-level alignment: statistical or linguistic. Due to the dissimilar grammar rules the languages have, the statistical algorithms usually give lower precision. That is why the development of this type of algorithms is generally aimed at a specific language pair using linguistic techniques. A hybrid alignment system based on the combination of the two traditional approaches is presented in this paper. It provides user-friendly configuration and is adaptable to the computational environment. The system uses linguistic resources and procedures such as identification of cognates, morphological information, syntactic trees, dictionaries, and semantic domains. We show that the system outperforms existing algorithms.

  5. Mechanism of cell alignment in groups of Myxococcus xanthus bacteria

    NASA Astrophysics Data System (ADS)

    Balgam, Rajesh; Igoshin, Oleg

    2015-03-01

    Myxococcus xanthus is a model for studying self-organization in bacteria. These flexible cylindrical bacteria move along. In groups, M. xanthus cells align themselves into dynamic cell clusters but the mechanism underlying their formation is unknown. It has been shown that steric interactions can cause alignment in self-propelled hard rods but it is not clear how flexibility and reversals affect the alignment and cluster formation. We have investigated cell alignment process using our biophysical model of M. xanthus cell in an agent-based simulation framework under realistic cell flexibility values. We observed that flexible model cells can form aligned cell clusters when reversals are suppressed but these clusters disappeared when reversals frequency becomes similar to the observed value. However, M. xanthus cells follow slime (polysaccharide gel like material) trails left by other cells and we show that implementing this into our model rescues cell clustering for reversing cells. Our results show that slime following along with periodic cell reversals act as positive feedback to reinforce existing slime trails and recruit more cells. Furthermore, we have observed that mechanical cell alignment combined with slime following is sufficient to explain the distinct clustering patterns of reversing and non-reversing cells as observed in recent experiments. This work is supported by NSF MCB 0845919 and 1411780.

  6. An efficient method for multiple sequence alignment

    SciTech Connect

    Kim, J.; Pramanik, S.

    1994-12-31

    Multiple sequence alignment has been a useful method in the study of molecular evolution and sequence-structure relationships. This paper presents a new method for multiple sequence alignment based on simulated annealing technique. Dynamic programming has been widely used to find an optimal alignment. However, dynamic programming has several limitations to obtain optimal alignment. It requires long computation time and cannot apply certain types of cost functions. We describe detail mechanisms of simulated annealing for multiple sequence alignment problem. It is shown that simulated annealing can be an effective approach to overcome the limitations of dynamic programming in multiple sequence alignment problem.

  7. Bokeh mirror alignment for Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    Mueller, S. A.; Adam, J.; Ahnen, M. L.; Baack, D.; Balbo, M.; Bergmann, M.; Biland, A.; Blank, M.; Bretz, T.; Bruegge, K. A.; Buss, J.; Dmytriiev, A.; Dorner, D.; Einecke, S.; Hempfling, C.; Hildebrand, D.; Hughes, G.; Linhoff, L.; Mannheim, K.; Neise, D.; Neronov, A.; Noethe, M.; Paravac, A.; Pauss, F.; Rhode, W.; Shukla, A.; Temme, F.; Thaele, J.; Walter, R.

    2016-08-01

    Segmented imaging reflectors are a great choice for Imaging Atmospheric Cherenkov Telescopes (IACTs). However, the alignment of the individual mirror facets is challenging. We align a segmented reflector by observing and optimizing its Bokeh function. Bokeh alignment can already be done with very little resources and little preparation time. Further, Bokeh alignment can be done anytime, even during the day. We present a first usage of Bokeh alignment on FACT, a 4m IACT on Canary Island La Palma, Spain and further a first Bokeh alignment test on the CTA MST IACT prototype in Brelin Adlershof.

  8. Showing What They Know

    ERIC Educational Resources Information Center

    Cech, Scott J.

    2008-01-01

    Having students show their skills in three dimensions, known as performance-based assessment, dates back at least to Socrates. Individual schools such as Barrington High School--located just outside of Providence--have been requiring students to actively demonstrate their knowledge for years. The Rhode Island's high school graduating class became…

  9. The Ozone Show.

    ERIC Educational Resources Information Center

    Mathieu, Aaron

    2000-01-01

    Uses a talk show activity for a final assessment tool for students to debate about the ozone hole. Students are assessed on five areas: (1) cooperative learning; (2) the written component; (3) content; (4) self-evaluation; and (5) peer evaluation. (SAH)

  10. What Do Maps Show?

    ERIC Educational Resources Information Center

    Geological Survey (Dept. of Interior), Reston, VA.

    This curriculum packet, appropriate for grades 4-8, features a teaching poster which shows different types of maps (different views of Salt Lake City, Utah), as well as three reproducible maps and reproducible activity sheets which complement the maps. The poster provides teacher background, including step-by-step lesson plans for four geography…

  11. Show Me the Way

    ERIC Educational Resources Information Center

    Dicks, Matthew J.

    2005-01-01

    Because today's students have grown up steeped in video games and the Internet, most of them expect feedback, and usually gratification, very soon after they expend effort on a task. Teachers can get quick feedback to students by showing them videotapes of their learning performances. The author, a 3rd grade teacher describes how the seemingly…

  12. Chemistry Game Shows

    NASA Astrophysics Data System (ADS)

    Campbell, Susan; Muzyka, Jennifer

    2002-04-01

    We present a technological improvement to the use of game shows to help students review for tests. Our approach uses HTML files interpreted with a browser on a computer attached to an LCD projector. The HTML files can be easily modified for use of the game in a variety of courses.

  13. Honored Teacher Shows Commitment.

    ERIC Educational Resources Information Center

    Ratte, Kathy

    1987-01-01

    Part of the acceptance speech of the 1985 National Council for the Social Studies Teacher of the Year, this article describes the censorship experience of this honored social studies teacher. The incident involved the showing of a videotape version of the feature film entitled "The Seduction of Joe Tynan." (JDH)

  14. Talk Show Science.

    ERIC Educational Resources Information Center

    Moore, Mitzi Ruth

    1992-01-01

    Proposes having students perform skits in which they play the roles of the science concepts they are trying to understand. Provides the dialog for a skit in which hot and cold gas molecules are interviewed on a talk show to study how these properties affect wind, rain, and other weather phenomena. (MDH)

  15. Stage a Water Show

    ERIC Educational Resources Information Center

    Frasier, Debra

    2008-01-01

    In the author's book titled "The Incredible Water Show," the characters from "Miss Alaineus: A Vocabulary Disaster" used an ocean of information to stage an inventive performance about the water cycle. In this article, the author relates how she turned the story into hands-on science teaching for real-life fifth-grade students. The author also…

  16. Liquid Crystal Research Shows Deformation By Drying

    NASA Technical Reports Server (NTRS)

    2003-01-01

    These images, from David Weitz's liquid crystal research, show ordered uniform sized droplets (upper left) before they are dried from their solution. After the droplets are dried (upper right), they are viewed with crossed polarizers that show the deformation caused by drying, a process that orients the bipolar structure of the liquid crystal within the droplets. When an electric field is applied to the dried droplets (lower left), and then increased (lower right), the liquid crystal within the droplets switches its alignment, thereby reducing the amount of light that can be scattered by the droplets when a beam is shone through them.

  17. Prism Window for Optical Alignment

    NASA Technical Reports Server (NTRS)

    Tang, Hong

    2008-01-01

    A prism window has been devised for use, with an autocollimator, in aligning optical components that are (1) required to be oriented parallel to each other and/or at a specified angle of incidence with respect to a common optical path and (2) mounted at different positions along the common optical path. The prism window can also be used to align a single optical component at a specified angle of incidence. Prism windows could be generally useful for orienting optical components in manufacture of optical instruments. "Prism window" denotes an application-specific unit comprising two beam-splitter windows that are bonded together at an angle chosen to obtain the specified angle of incidence.

  18. Aligned mesoporous architectures and devices.

    SciTech Connect

    Brinker, C. Jeffrey; Lu, Yunfeng

    2011-03-01

    This is the final report for the Presidential Early Career Award for Science and Engineering - PECASE (LDRD projects 93369 and 118841) awarded to Professor Yunfeng Lu (Tulane University and University of California-Los Angeles). During the last decade, mesoporous materials with tunable periodic pores have been synthesized using surfactant liquid crystalline as templates, opening a new avenue for a wide spectrum of applications. However, the applications are somewhat limited by the unfavorabe pore orientation of these materials. Although substantial effort has been devoted to align the pore channels, fabrication of mesoporous materials with perpendicular pore channels remains challenging. This project focused on fabrication of mesoporous materials with perpendicularly aligned pore channels. We demonstrated structures for use in water purification, separation, sensors, templated synthesis, microelectronics, optics, controlled release, and highly selective catalysts.

  19. Intrinsic alignments of galaxies in the EAGLE and cosmo-OWLS simulations

    NASA Astrophysics Data System (ADS)

    Velliscig, Marco; Cacciato, Marcello; Schaye, Joop; Hoekstra, Henk; Bower, Richard G.; Crain, Robert A.; van Daalen, Marcel P.; Furlong, Michelle; McCarthy, I. G.; Schaller, Matthieu; Theuns, Tom

    2015-12-01

    We report results for the alignments of galaxies in the EAGLE and cosmo-OWLS hydrodynamical cosmological simulations as a function of galaxy separation (-1 ≤ log10(r/[ h-1 Mpc]) ≤ 2) and halo mass (10.7 ≤ log10(M200/[h-1 M⊙]) ≤ 15). We focus on two classes of alignments: the orientations of galaxies with respect to either the directions to, or the orientations of, surrounding galaxies. We find that the strength of the alignment is a strongly decreasing function of the distance between galaxies. For galaxies hosted by the most massive haloes in our simulations the alignment can remain significant up to ˜100 Mpc. Galaxies hosted by more massive haloes show stronger alignment. At a fixed halo mass, more aspherical or prolate galaxies exhibit stronger alignments. The spatial distribution of satellites is anisotropic and significantly aligned with the major axis of the main host halo. The major axes of satellite galaxies, when all stars are considered, are preferentially aligned towards the centre of the main host halo. The predicted projected direction-orientation alignment, ɛg+(rp), is in broad agreement with recent observations. We find that the orientation-orientation alignment is weaker than the orientation-direction alignment on all scales. Overall, the strength of galaxy alignments depends strongly on the subset of stars that are used to measure the orientations of galaxies and it is always weaker than the alignment of dark matter haloes. Thus, alignment models that use halo orientation as a direct proxy for galaxy orientation overestimate the impact of intrinsic galaxy alignments.

  20. Speeding up Batch Alignment of Large Ontologies Using MapReduce.

    PubMed

    Thayasivam, Uthayasanker; Doshi, Prashant

    2013-09-01

    Real-world ontologies tend to be very large with several containing thousands of entities. Increasingly, ontologies are hosted in repositories, which often compute the alignment between the ontologies. As new ontologies are submitted or ontologies are updated, their alignment with others must be quickly computed. Therefore, aligning several pairs of ontologies quickly becomes a challenge for these repositories. We project this problem as one of batch alignment and show how it may be approached using the distributed computing paradigm of MapReduce. Our approach allows any alignment algorithm to be utilized on a MapReduce architecture. Experiments using four representative alignment algorithms demonstrate flexible and significant speedup of batch alignment of large ontology pairs using MapReduce.

  1. Constructing sequence alignments from a Markov decision model with estimated parameter values.

    PubMed

    Hunt, Fern Y; Kearsley, Anthony J; O'Gallagher, Agnes

    2004-01-01

    Current methods for aligning biological sequences are based on dynamic programming algorithms. If large numbers of sequences or a number of long sequences are to be aligned, the required computations are expensive in memory and central processing unit (CPU) time. In an attempt to bring the tools of large-scale linear programming (LP) methods to bear on this problem, we formulate the alignment process as a controlled Markov chain and construct a suggested alignment based on policies that minimise the expected total cost of the alignment. We discuss the LP associated with the total expected discounted cost and show the results of a solution of the problem based on a primal-dual interior point method. Model parameters, estimated from aligned sequences, along with cost function parameters are used to construct the objective and constraint conditions of the LP problem. This article concludes with a discussion of some alignments obtained from the LP solutions of problems with various cost function parameter values.

  2. Aligning incentives in supply chains.

    PubMed

    Narayanan, V G; Raman, Ananth

    2004-11-01

    Most companies don't worry about the behavior of their supply chain partners. Instead, they expect the supply chain to work efficiently without interference, as if guided by Adam Smith's famed invisible hand. In their study of more than 50 supply networks, V.G. Narayanan and Ananth Raman found that companies often looked out for their own interests and ignored those of their network partners. Consequently, supply chains performed poorly. Those results aren't shocking when you consider that supply chains extend across several functions and many companies, each with its own priorities and goals. Yet all those functions and firms must pull in the same direction for a chain to deliver goods and services to consumers quickly and cost-effectively. According to the authors, a supply chain works well only if the risks, costs, and rewards of doing business are distributed fairly across the network. In fact, misaligned incentives are often the cause of excess inventory, stock-outs, incorrect forecasts, inadequate sales efforts, and even poor customer service. The fates of all supply chain partners are interlinked: If the firms work together to serve consumers, they will all win. However, they can do that only if incentives are aligned. Companies must acknowledge that the problem of incentive misalignment exists and then determine its root cause and align or redesign incentives. They can improve alignment by, for instance, adopting revenue-sharing contracts, using technology to track previously hidden information, or working with intermediaries to build trust among network partners. It's also important to periodically reassess incentives, because even top-performing networks find that changes in technology or business conditions alter the alignment of incentives.

  3. Fiber alignment apparatus and method

    DOEpatents

    Kravitz, S.H.; Warren, M.E.; Snipes, M.B. Jr.; Armendariz, M.G.; Word, J.C. V

    1997-08-19

    A fiber alignment apparatus includes a micro-machined nickel spring that captures and locks arrays of single mode fibers into position. The design consists of a movable nickel leaf shaped spring and a fixed pocket where fibers are held. The fiber is slid between the spring and a fixed block, which tensions the spring. When the fiber reaches the pocket, it automatically falls into the pocket and is held by the pressure of the leaf spring. 8 figs.

  4. Fiber alignment apparatus and method

    DOEpatents

    Kravitz, Stanley H.; Warren, Mial Evans; Snipes, Jr., Morris Burton; Armendariz, Marcelino Guadalupe; Word, V., James Cole

    1997-01-01

    A fiber alignment apparatus includes a micro-machined nickel spring that captures and locks arrays of single mode fibers into position. The design consists of a movable nickel leaf shaped spring and a fixed pocket where fibers are held. The fiber is slid between the spring and a fixed block, which tensions the spring. When the fiber reaches the pocket, it automatically falls into the pocket and is held by the pressure of the leaf spring.

  5. Threaded pilot insures cutting tool alignment

    NASA Technical Reports Server (NTRS)

    Goldman, R.; Schneider, W. E.

    1966-01-01

    Threaded pilot allows machining of a port component, or boss, after the reciprocating hole has been threaded. It is used to align cutting surfaces with the boss threads, thus insuring precision alignment.

  6. Not a "reality" show.

    PubMed

    Wrong, Terence; Baumgart, Erica

    2013-01-01

    The authors of the preceding articles raise legitimate questions about patient and staff rights and the unintended consequences of allowing ABC News to film inside teaching hospitals. We explain why we regard their fears as baseless and not supported by what we heard from individuals portrayed in the filming, our decade-long experience making medical documentaries, and the full un-aired context of the scenes shown in the broadcast. The authors don't and can't know what conversations we had, what documents we reviewed, and what protections we put in place in each televised scene. Finally, we hope to correct several misleading examples cited by the authors as well as their offhand mischaracterization of our program as a "reality" show.

  7. Spatio-temporal alignment of pedobarographic image sequences.

    PubMed

    Oliveira, Francisco P M; Sousa, Andreia; Santos, Rubim; Tavares, João Manuel R S

    2011-07-01

    This article presents a methodology to align plantar pressure image sequences simultaneously in time and space. The spatial position and orientation of a foot in a sequence are changed to match the foot represented in a second sequence. Simultaneously with the spatial alignment, the temporal scale of the first sequence is transformed with the aim of synchronizing the two input footsteps. Consequently, the spatial correspondence of the foot regions along the sequences as well as the temporal synchronizing is automatically attained, making the study easier and more straightforward. In terms of spatial alignment, the methodology can use one of four possible geometric transformation models: rigid, similarity, affine, or projective. In the temporal alignment, a polynomial transformation up to the 4th degree can be adopted in order to model linear and curved time behaviors. Suitable geometric and temporal transformations are found by minimizing the mean squared error (MSE) between the input sequences. The methodology was tested on a set of real image sequences acquired from a common pedobarographic device. When used in experimental cases generated by applying geometric and temporal control transformations, the methodology revealed high accuracy. In addition, the intra-subject alignment tests from real plantar pressure image sequences showed that the curved temporal models produced better MSE results (P < 0.001) than the linear temporal model. This article represents an important step forward in the alignment of pedobarographic image data, since previous methods can only be applied on static images.

  8. A two-stage approach to automatic face alignment

    NASA Astrophysics Data System (ADS)

    Wang, Tong; Ai, Haizhou; Huang, Gaofeng

    2003-09-01

    Face alignment is very important in face recognition, modeling and synthesis. Many approaches have been developed for this purpose, such as ASM, AAM, DAM and TC-ASM. After a brief review of all those methods, it is pointed out that these approaches all require a manual initialization to the positions of the landmarks and are very sensitive to it, and despite of all those devoted works the outline of a human face remains a difficult task to be localized precisely. In this paper, a two-stage method to achieve frontal face alignment fully automatically is introduced. The first stage is landmarks' initialization called coarse face alignment. In this stage, after a face is detected by an Adaboost cascade face detector, we use Simple Direct Appearance Model (SDAM) to locate a few key points of human face from the texture according which all the initial landmarks are setup as the coarse alignment. The second stage is fine face alignment that uses a variant of AAM method in which shape variation is predicted from texture reconstruction error together with an embedded ASM refinement for the outline landmarks of the face to achieve the fine alignment. Experiments on a face database of 500 people show that this method is very effective for practical applications.

  9. Optimizing a global alignment of protein interaction networks

    PubMed Central

    Chindelevitch, Leonid; Ma, Cheng-Yu; Liao, Chung-Shou; Berger, Bonnie

    2013-01-01

    Motivation: The global alignment of protein interaction networks is a widely studied problem. It is an important first step in understanding the relationship between the proteins in different species and identifying functional orthologs. Furthermore, it can provide useful insights into the species’ evolution. Results: We propose a novel algorithm, PISwap, for optimizing global pairwise alignments of protein interaction networks, based on a local optimization heuristic that has previously demonstrated its effectiveness for a variety of other intractable problems. PISwap can begin with different types of network alignment approaches and then iteratively adjust the initial alignments by incorporating network topology information, trading it off for sequence information. In practice, our algorithm efficiently refines other well-studied alignment techniques with almost no additional time cost. We also show the robustness of the algorithm to noise in protein interaction data. In addition, the flexible nature of this algorithm makes it suitable for different applications of network alignment. This algorithm can yield interesting insights into the evolutionary dynamics of related species. Availability: Our software is freely available for non-commercial purposes from our Web site, http://piswap.csail.mit.edu/. Contact: bab@csail.mit.edu or csliao@ie.nthu.edu.tw Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24048352

  10. Static rearfoot alignment: a comparison of clinical and radiographic measures.

    PubMed

    Lamm, Bradley M; Mendicino, Robert W; Catanzariti, Alan R; Hillstrom, Howard J

    2005-01-01

    Foot structure is typically evaluated using static clinical and radiographic measures. To date, the literature is devoid of a correlation between rearfoot frontal plane radiographic parameters and clinical measures of alignment. In a repeated-measures study comparing radiographic and clinical rearfoot alignment in 24 healthy subjects, radiographic angular measurements were made from standard weightbearing anteroposterior, lateral, long leg calcaneal axial, and rearfoot alignment views. Clinical measurements were made using a jig and scanner to assess the malleolar valgus index and a goniometer to evaluate the resting and neutral calcaneal stance positions. There was a significant correlation between frontal plane radiographic angles (long leg calcaneal axial and rearfoot alignment views) (r = 0.814). Similarly, there was a significant correlation between clinical measures (resting calcaneal stance position and malleolar valgus index) (r = 0.714). A multivariate stepwise regression showed that resting calcaneal stance position can be accurately predicted from 3 of the 15 clinical and radiographic measurements collected: malleolar valgus index, rearfoot alignment view, and long leg calcaneal axial view (r = 0.829). In summary, a commonly used clinical measure of static rearfoot alignment, resting calcaneal stance position, was correlated closely with the malleolar valgus index and both frontal plane radiographic parameters.

  11. Automatic Parameter Learning for Multiple Local Network Alignment

    PubMed Central

    Novak, Antal; Do, Chuong B.; Srinivasan, Balaji S.; Batzoglou, Serafim

    2009-01-01

    Abstract We developed Græmlin 2.0, a new multiple network aligner with (1) a new multi-stage approach to local network alignment; (2) a novel scoring function that can use arbitrary features of a multiple network alignment, such as protein deletions, protein duplications, protein mutations, and interaction losses; (3) a parameter learning algorithm that uses a training set of known network alignments to learn parameters for our scoring function and thereby adapt it to any set of networks; and (4) an algorithm that uses our scoring function to find approximate multiple network alignments in linear time. We tested Græmlin 2.0's accuracy on protein interaction networks from IntAct, DIP, and the Stanford Network Database. We show that, on each of these datasets, Græmlin 2.0 has higher sensitivity and specificity than existing network aligners. Græmlin 2.0 is available under the GNU public license at http://graemlin.stanford.edu. PMID:19645599

  12. Electrospun nanofiber reinforcement of dental composites with electromagnetic alignment approach.

    PubMed

    Uyar, Tansel; Çökeliler, Dilek; Doğan, Mustafa; Koçum, Ismail Cengiz; Karatay, Okan; Denkbaş, Emir Baki

    2016-05-01

    Polymethylmethacrylate (PMMA) is commonly used as a base acrylic denture material with benefits of rapid and easy handling, however, when it is used in prosthetic dentistry, fracturing or cracking problems can be seen due to the relatively low strength issues. Besides, acrylic resin is the still prominent material for denture fabrication due to its handy and low cost features. Numerous proposed fillers that are used to produce PMMA composites, however electrospun polyvinylalcohol (PVA) nanofiber fillers for production of PMMA composite resins are not studied as much as the others. The other focus of the practice is to compare both mechanical properties and efficiency of aligned fibers versus non-aligned PVA nanofibers in PMMA based dental composites. Field-controlled electrospinning system is manufactured and provided good alignment in lab scale as one of contributions. Some novel auxiliary electrodes in controlled structure are augmented to obtain different patterns of alignment with a certain range of fiber diameters. Scanning electron microscopy is used for physical characterization to determine the range of fiber diameters. Non-woven fiber has no unique pattern due to chaotic nature of electrospinning process, but aligned fibers have round pattern or crossed lines. These produced fibers are structured as layer-by-layer form with different features, and these features are used in producing PMMA dental composites with different volume ratios. The maximum flexural strength figure shows that fiber load by weight of 0.25% w/w and above improves in the maximum level. As a result, mechanical properties of PMMA dental composites are improved by using PVA nanofibers as a filler, however the improvement was higher when aligned PVA nanofibers are used. The maximum values were 5.1 MPa (flexural strength), 0.8 GPa (elastic modulus), and 170 kJ/m(3) (toughness) in three-point bending test. In addition to the positive results of aligned and non-aligned nanofibers it was found

  13. Aligning Plasma-Arc Welding Oscillations

    NASA Technical Reports Server (NTRS)

    Norris, Jeff; Fairley, Mike

    1989-01-01

    Tool aids in alignment of oscillator probe on variable-polarity plasma-arc welding torch. Probe magnetically pulls arc from side to side as it moves along joint. Tensile strength of joint depends on alignment of weld bead and on alignment of probe. Operator installs new tool on front of torch body, levels it with built-in bubble glass, inserts probe in slot on tool, and locks probe in place. Procedure faster and easier and resulting alignment more accurate and repeatable.

  14. Use laser-optics for machinery alignment

    SciTech Connect

    Bloch, H.P.

    1987-10-01

    Many sources attribute most bearing overload and destructive vibration in industrial machinery to shaft misalignment. There is considerable disagreement as to the alignment quality required. There is also little agreement on suitable calculation methods and achievable accuracy for anticipated thermal growth of machinery (necessary if running alignment is to remain acceptable). This article examines existing alignment quality guidelines for relevance and consistency, and reviews the application of laser-optic alignment systems based on three years of field experience.

  15. Trace analysis of Ponceau 4R in soft drinks using differential pulse stripping voltammetry at SWCNTs composite electrodes based on PEDOT:PSS derivatives.

    PubMed

    Wang, Zifei; Zhang, Hui; Wang, Zhipeng; Zhang, Jie; Duan, Xuemin; Xu, Jingkun; Wen, Yangping

    2015-08-01

    Ponceau 4R, an edible synthetic colorant used in drinks, syrups, and sweets, has been successfully detected using differential pulse voltammetry at a single-walled carbon nanotubes-modified composite electrode based on poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) and two derivatives thereof. The electrochemical parameters of three Ponceau 4R sensors, such as pH value, pre-concentration time, and scan rate, have been optimized, and their electrochemical performances have been compared. A poly(acrylate-modified 3,4-ethylenedioxythiophene-co-3,4-ethylenedioxythiophene):poly(styrene sulfonate)-single-walled carbon nanotubes-poly(vinyl alcohol)-modified electrode showed the best electrocatalytic activity, with the highest response current, lowest detection limit (1.8 nm), widest linear range (0.0055-110.6 μm), and best sensing stability. Additionally, the modified electrode has also been successfully employed for real sample analysis with soft drinks. Satisfactory results were obtained, demonstrating this to be an easy and effective approach for trace analysis of Ponceau 4R in food samples.

  16. Public medical shows.

    PubMed

    Walusinski, Olivier

    2014-01-01

    In the second half of the 19th century, Jean-Martin Charcot (1825-1893) became famous for the quality of his teaching and his innovative neurological discoveries, bringing many French and foreign students to Paris. A hunger for recognition, together with progressive and anticlerical ideals, led Charcot to invite writers, journalists, and politicians to his lessons, during which he presented the results of his work on hysteria. These events became public performances, for which physicians and patients were transformed into actors. Major newspapers ran accounts of these consultations, more like theatrical shows in some respects. The resultant enthusiasm prompted other physicians in Paris and throughout France to try and imitate them. We will compare the form and substance of Charcot's lessons with those given by Jules-Bernard Luys (1828-1897), Victor Dumontpallier (1826-1899), Ambroise-Auguste Liébault (1823-1904), Hippolyte Bernheim (1840-1919), Joseph Grasset (1849-1918), and Albert Pitres (1848-1928). We will also note their impact on contemporary cinema and theatre.

  17. Vertically aligned nanostructure scanning probe microscope tips

    DOEpatents

    Guillorn, Michael A.; Ilic, Bojan; Melechko, Anatoli V.; Merkulov, Vladimir I.; Lowndes, Douglas H.; Simpson, Michael L.

    2006-12-19

    Methods and apparatus are described for cantilever structures that include a vertically aligned nanostructure, especially vertically aligned carbon nanofiber scanning probe microscope tips. An apparatus includes a cantilever structure including a substrate including a cantilever body, that optionally includes a doped layer, and a vertically aligned nanostructure coupled to the cantilever body.

  18. Ultrafast electron diffraction from aligned molecules

    SciTech Connect

    Centurion, Martin

    2015-08-17

    The aim of this project was to record time-resolved electron diffraction patterns of aligned molecules and to reconstruct the 3D molecular structure. The molecules are aligned non-adiabatically using a femtosecond laser pulse. A femtosecond electron pulse then records a diffraction pattern while the molecules are aligned. The diffraction patterns are then be processed to obtain the molecular structure.

  19. Does pilates-based exercise improve postural alignment in adult women?

    PubMed

    Cruz-Ferreira, Ana; Fernandes, Jorge; Kuo, Yi-Liang; Bernardo, Lisa Marie; Fernandes, Orlando; Laranjo, Luís; Silva, António

    2013-01-01

    A randomized, controlled trial was conducted to determine the effect of Pilates-based exercise on postural alignment. Seventy-four adult women (mean age ± SD, 34.9 ± 16.4 years) were randomized to a Pilates-based mat class (n = 40) or a control group (n = 34). Pilates-based exercise participants were taught the Initial Mat of Body Control Pilates for 6 months, twice a week, for 60 minutes per session; the control group received no exercise intervention. Repeated measurements were performed at baseline, 3 months, and 6 months of the frontal alignment of the thoracolumbar spine, shoulder, and pelvis, and sagittal alignment of the head and pelvis. No differences were found in either group, over time, on frontal alignment of the thoracolumbar spine and pelvis. The experimental group showed significant improvements in frontal alignment of the shoulder and sagittal alignment of the head and pelvis at 6 months. The Pilates-based exercise enhanced some parameters of the postural alignment of women, as measured by frontal alignment of the shoulder and sagittal alignment of the head and pelvis. The significant improvement in sagittal alignment of the head may imply that 6 months of Pilates-based exercise enhances sagittal alignment of the cervical or thoracic spine.

  20. The Great Cometary Show

    NASA Astrophysics Data System (ADS)

    2007-01-01

    its high spatial and spectral resolution, it was possible to zoom into the very heart of this very massive star. In this innermost region, the observations are dominated by the extremely dense stellar wind that totally obscures the underlying central star. The AMBER observations show that this dense stellar wind is not spherically symmetric, but exhibits a clearly elongated structure. Overall, the AMBER observations confirm that the extremely high mass loss of Eta Carinae's massive central star is non-spherical and much stronger along the poles than in the equatorial plane. This is in agreement with theoretical models that predict such an enhanced polar mass-loss in the case of rapidly rotating stars. ESO PR Photo 06c/07 ESO PR Photo 06c/07 RS Ophiuchi in Outburst Several papers from this special feature focus on the later stages in a star's life. One looks at the binary system Gamma 2 Velorum, which contains the closest example of a star known as a Wolf-Rayet. A single AMBER observation allowed the astronomers to separate the spectra of the two components, offering new insights in the modeling of Wolf-Rayet stars, but made it also possible to measure the separation between the two stars. This led to a new determination of the distance of the system, showing that previous estimates were incorrect. The observations also revealed information on the region where the winds from the two stars collide. The famous binary system RS Ophiuchi, an example of a recurrent nova, was observed just 5 days after it was discovered to be in outburst on 12 February 2006, an event that has been expected for 21 years. AMBER was able to detect the extension of the expanding nova emission. These observations show a complex geometry and kinematics, far from the simple interpretation of a spherical fireball in extension. AMBER has detected a high velocity jet probably perpendicular to the orbital plane of the binary system, and allowed a precise and careful study of the wind and the shockwave

  1. Stretched View Showing 'Victoria'

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Stretched View Showing 'Victoria'

    This pair of images from the panoramic camera on NASA's Mars Exploration Rover Opportunity served as initial confirmation that the two-year-old rover is within sight of 'Victoria Crater,' which it has been approaching for more than a year. Engineers on the rover team were unsure whether Opportunity would make it as far as Victoria, but scientists hoped for the chance to study such a large crater with their roving geologist. Victoria Crater is 800 meters (nearly half a mile) in diameter, about six times wider than 'Endurance Crater,' where Opportunity spent several months in 2004 examining rock layers affected by ancient water.

    When scientists using orbital data calculated that they should be able to detect Victoria's rim in rover images, they scrutinized frames taken in the direction of the crater by the panoramic camera. To positively characterize the subtle horizon profile of the crater and some of the features leading up to it, researchers created a vertically-stretched image (top) from a mosaic of regular frames from the panoramic camera (bottom), taken on Opportunity's 804th Martian day (April 29, 2006).

    The stretched image makes mild nearby dunes look like more threatening peaks, but that is only a result of the exaggerated vertical dimension. This vertical stretch technique was first applied to Viking Lander 2 panoramas by Philip Stooke, of the University of Western Ontario, Canada, to help locate the lander with respect to orbiter images. Vertically stretching the image allows features to be more readily identified by the Mars Exploration Rover science team.

    The bright white dot near the horizon to the right of center (barely visible without labeling or zoom-in) is thought to be a light-toned outcrop on the far wall of the crater, suggesting that the rover can see over the low rim of Victoria. In figure 1, the northeast and southeast rims are labeled

  2. Disorientation of Suprathermally Rotating Grains and the Grain Alignment Problem

    NASA Astrophysics Data System (ADS)

    Lazarian, A.; Draine, B. T.

    1997-09-01

    We discuss the dynamics of dust grains subjected to torques arising from H2 formation. In particular, we discuss grain dynamics when a grain spins down and goes through a ``crossover'' event. As first pointed out by Spitzer & McGlynn, the grain angular momentum before and after a crossover event are correlated, and the degree of this correlation critically affects the alignment of dust grains by paramagnetic dissipation. We calculate the correlation including the important effects of thermal fluctuations within the grain material. These fluctuations limit the degree to which the grain angular momentum J is coupled with the grain principal axis a1 of maximal inertia. We show that this imperfect coupling of a1 with J plays a critical role during crossovers and can substantially increase the efficiency of paramagnetic alignment for grains larger than 0.1 μm. As a result, we show that for reasonable choices of parameters, the observed alignment of a >~ 0.1 μm grains could be achieved by paramagnetic dissipation in suprathermally rotating grains, if radiative torques caused by starlight were not present. We also show that the efficiency of mechanical alignment in the limit of long alignment times is not altered by the thermal fluctuations in the grain material. This paper is dedicated to the memory of Lyman Spitzer, Jr.

  3. ASH structure alignment package: Sensitivity and selectivity in domain classification

    PubMed Central

    Standley, Daron M; Toh, Hiroyuki; Nakamura, Haruki

    2007-01-01

    Background Structure alignment methods offer the possibility of measuring distant evolutionary relationships between proteins that are not visible by sequence-based analysis. However, the question of how structural differences and similarities ought to be quantified in this regard remains open. In this study we construct a training set of sequence-unique CATH and SCOP domains, from which we develop a scoring function that can reliably identify domains with the same CATH topology and SCOP fold classification. The score is implemented in the ASH structure alignment package, for which the source code and a web service are freely available from the PDBj website . Results The new ASH score shows increased selectivity and sensitivity compared with values reported for several popular programs using the same test set of 4,298,905 structure pairs, yielding an area of .96 under the receiver operating characteristic (ROC) curve. In addition, weak sequence homologies between similar domains are revealed that could not be detected by BLAST sequence alignment. Also, a subset of domain pairs is identified that exhibit high similarity, even though their CATH and SCOP classification differs. Finally, we show that the ranking of alignment programs based solely on geometric measures depends on the choice of the quality measure. Conclusion ASH shows high selectivity and sensitivity with regard to domain classification, an important step in defining distantly related protein sequence families. Moreover, the CPU cost per alignment is competitive with the fastest programs, making ASH a practical option for large-scale structure classification studies. PMID:17407606

  4. Aligning Two Genomic Sequences That Contain Duplications

    NASA Astrophysics Data System (ADS)

    Hou, Minmei; Riemer, Cathy; Berman, Piotr; Hardison, Ross C.; Miller, Webb

    It is difficult to properly align genomic sequences that contain intra-species duplications. With this goal in mind, we have developed a tool, called TOAST (two-way orthologous alignment selection tool), for predicting whether two aligned regions from different species are orthologous, i.e., separated by a speciation event, as opposed to a duplication event. The advantage of restricting alignment to orthologous pairs is that they constitute the aligning regions that are most likely to share the same biological function, and most easily analyzed for evidence of selection. We evaluate TOAST on 12 human/mouse gene clusters.

  5. Accelerator and transport line survey and alignment

    SciTech Connect

    Ruland, R.E.

    1991-10-01

    This paper summarizes the survey and alignment processes of accelerators and transport lines and discusses the propagation of errors associated with these processes. The major geodetic principles governing the survey and alignment measurement space are introduced and their relationship to a lattice coordinate system shown. The paper continues with a broad overview about the activities involved in the step sequence from initial absolute alignment to final smoothing. Emphasis is given to the relative alignment of components, in particular to the importance of incorporating methods to remove residual systematic effects in surveying and alignment operations. Various approaches to smoothing used at major laboratories are discussed. 47 refs., 19 figs., 1 tab.

  6. L-GRAAL: Lagrangian graphlet-based network aligner

    PubMed Central

    Malod-Dognin, Noël; Pržulj, Nataša

    2015-01-01

    Motivation: Discovering and understanding patterns in networks of protein–protein interactions (PPIs) is a central problem in systems biology. Alignments between these networks aid functional understanding as they uncover important information, such as evolutionary conserved pathways, protein complexes and functional orthologs. A few methods have been proposed for global PPI network alignments, but because of NP-completeness of underlying sub-graph isomorphism problem, producing topologically and biologically accurate alignments remains a challenge. Results: We introduce a novel global network alignment tool, Lagrangian GRAphlet-based ALigner (L-GRAAL), which directly optimizes both the protein and the interaction functional conservations, using a novel alignment search heuristic based on integer programming and Lagrangian relaxation. We compare L-GRAAL with the state-of-the-art network aligners on the largest available PPI networks from BioGRID and observe that L-GRAAL uncovers the largest common sub-graphs between the networks, as measured by edge-correctness and symmetric sub-structures scores, which allow transferring more functional information across networks. We assess the biological quality of the protein mappings using the semantic similarity of their Gene Ontology annotations and observe that L-GRAAL best uncovers functionally conserved proteins. Furthermore, we introduce for the first time a measure of the semantic similarity of the mapped interactions and show that L-GRAAL also uncovers best functionally conserved interactions. In addition, we illustrate on the PPI networks of baker's yeast and human the ability of L-GRAAL to predict new PPIs. Finally, L-GRAAL's results are the first to show that topological information is more important than sequence information for uncovering functionally conserved interactions. Availability and implementation: L-GRAAL is coded in C++. Software is available at: http://bio-nets.doc.ic.ac.uk/L-GRAAL/. Contact: n

  7. AXAF Alignment Test System Autocollimating Flat Error Correction

    NASA Technical Reports Server (NTRS)

    Lewis, Timothy S.

    1995-01-01

    The alignment test system for the advanced x ray astrophysics facility (AXAF) high-resolution mirror assembly (HRMA) determines the misalignment of the HRMA by measuring the displacement of a beam of light reflected by the HRMA mirrors and an autocollimating flat (ACF). This report shows how to calibrate the system to compensate for errors introduced by the ACF, using measurements taken with the ACF in different positions. It also shows what information can be obtained from alignment test data regarding errors in the shapes of the HRMA mirrors. Simulated results based on measured ACF surface data are presented.

  8. Antares beam-alignment-system performance

    SciTech Connect

    Appert, Q.D.; Bender, S.C.

    1983-01-01

    The beam alignment system for the 24-beam-sector Antares CO/sub 2/ fusion laser automatically aligns more than 200 optical elements. A visible-wavelength alignment technique is employed which uses a telescope/TV system to view point-light sources appropriately located down the beamline. The centroids of the light spots are determined by a video tracker, which generates error signals used by the computer control system to move appropriate mirrors in a closed-loop system. Final touch-up alignment is accomplished by projecting a CO/sub 2/ alignment laser beam through the system and sensing its position at the target location. The techniques and control algorithms employed have resulted in alignment accuracies exceeding design requirements. By employing video processing to determine the centroids of diffraction images and by averaging over multiple TV frames, we achieve alignment accuracies better than 0.1 times system diffraction limits in the presence of air turbulence.

  9. FOGSAA: Fast Optimal Global Sequence Alignment Algorithm

    NASA Astrophysics Data System (ADS)

    Chakraborty, Angana; Bandyopadhyay, Sanghamitra

    2013-04-01

    In this article we propose a Fast Optimal Global Sequence Alignment Algorithm, FOGSAA, which aligns a pair of nucleotide/protein sequences faster than any optimal global alignment method including the widely used Needleman-Wunsch (NW) algorithm. FOGSAA is applicable for all types of sequences, with any scoring scheme, and with or without affine gap penalty. Compared to NW, FOGSAA achieves a time gain of (70-90)% for highly similar nucleotide sequences (> 80% similarity), and (54-70)% for sequences having (30-80)% similarity. For other sequences, it terminates with an approximate score. For protein sequences, the average time gain is between (25-40)%. Compared to three heuristic global alignment methods, the quality of alignment is improved by about 23%-53%. FOGSAA is, in general, suitable for aligning any two sequences defined over a finite alphabet set, where the quality of the global alignment is of supreme importance.

  10. Aligned Nanofibers for Regenerating Arteries, Nerves, and Muscles

    NASA Astrophysics Data System (ADS)

    McClendon, Mark Trosper

    annular gap containing PA solution with a rotating rod. Using the shear aligning properties of PA solutions this rotating surface in contact with the PA solution induced a high degree of alignment in the nanofibers which was subsequently locked in place by introducing gelating calcium ions. again say something about what this fabrication procedure entails Cells encapsulated within these tubes responded to the alignment by extending in the circumferential direction mimicking the same cellular alignment observed in native arteries. A similar design strategy was also used to align nanofibers within the core of biopolymer nerve conduits, and these scaffolds were implanted in a rat sciatic nerve model. Histological and behavioral observations confirmed that PA implants sustained regeneration rates comparable to autologous grafts and significantly better than empty biopolymer grafts. Furthermore, these nanofiber gels were used as a vehicle to deliver stem cells into muscle tissue. A specialized injector was designed to introduce aligned PA gels into mouse leg muscles in a 1cm long channel. Bioluminescence and histology showed that stem cell engraftment into myofibers was greatly enhanced when delivered by PA gels compared to saline solution. The final section of this thesis describes a new series of PA molecules designed to degrade upon exposure to UV lightstate here why is this of interest in the context of the work described in the thesis. This was done to understand the degradation behavior of PA nanofibers and provide a controlled approach to changing the rheological properties post gelation.The three PA molecules in this series contained the same peptide sequence V3A3E3, while varying the location of a nitrobenzyl UV-reactive group along the backbone of the molecule. This system allowed for a quick reaction that cleaves the molecule at the reactive nitrobenzyl site without introducing any other reactive molecules. While all three molecules produced nanofibers that remained

  11. Pupil Alignment Measuring Technique and Alignment Reference for Instruments or Optical Systems

    NASA Technical Reports Server (NTRS)

    Hagopian, John G.

    2010-01-01

    A technique was created to measure the pupil alignment of instruments in situ by measuring calibrated pupil alignment references (PARs) in instruments. The PAR can also be measured using an alignment telescope or an imaging system. PAR allows the verification of the science instrument (SI) pupil alignment at the integrated science instrument module (ISIM) level of assembly at ambient and cryogenic operating temperature. This will allow verification of the ISIM+SI alignment, and provide feedback to realign the SI if necessary.

  12. Aligned interactions in cosmic rays

    NASA Astrophysics Data System (ADS)

    Kempa, J.

    2015-12-01

    The first clean Centauro was found in cosmic rays years many ago at Mt Chacaltaya experiment. Since that time, many people have tried to find this type of interaction, both in cosmic rays and at accelerators. But no one has found a clean cases of this type of interaction.It happened finally in the last exposure of emulsion at Mt Chacaltaya where the second clean Centauro has been found. The experimental data for both the Centauros and STRANA will be presented and discussed in this paper. We also present our comments to the intriguing question of the existence of a type of nuclear interactions at high energy with alignment.

  13. MEANS FOR DETERMINING CENTRIFUGE ALIGNMENT

    DOEpatents

    Smith, W.Q.

    1958-08-26

    An apparatus is presented for remotely determining the alignment of a centrifuge. The centrifage shaft is provided with a shoulder, upon which two followers ride, one for detecting radial movements, and one upon the shoulder face for determining the axial motion. The followers are attached to separate liquid filled bellows, and a tube connects each bellows to its respective indicating gage at a remote location. Vibrations produced by misalignment of the centrifuge shaft are transmitted to the bellows, and tbence through the tubing to the indicator gage. This apparatus is particularly useful for operation in a hot cell where the materials handled are dangerous to the operating personnel.

  14. Aligned interactions in cosmic rays

    SciTech Connect

    Kempa, J.

    2015-12-15

    The first clean Centauro was found in cosmic rays years many ago at Mt Chacaltaya experiment. Since that time, many people have tried to find this type of interaction, both in cosmic rays and at accelerators. But no one has found a clean cases of this type of interaction.It happened finally in the last exposure of emulsion at Mt Chacaltaya where the second clean Centauro has been found. The experimental data for both the Centauros and STRANA will be presented and discussed in this paper. We also present our comments to the intriguing question of the existence of a type of nuclear interactions at high energy with alignment.

  15. Method for protein structure alignment

    DOEpatents

    Blankenbecler, Richard; Ohlsson, Mattias; Peterson, Carsten; Ringner, Markus

    2005-02-22

    This invention provides a method for protein structure alignment. More particularly, the present invention provides a method for identification, classification and prediction of protein structures. The present invention involves two key ingredients. First, an energy or cost function formulation of the problem simultaneously in terms of binary (Potts) assignment variables and real-valued atomic coordinates. Second, a minimization of the energy or cost function by an iterative method, where in each iteration (1) a mean field method is employed for the assignment variables and (2) exact rotation and/or translation of atomic coordinates is performed, weighted with the corresponding assignment variables.

  16. Strategy for alignment of electron beam trajectory in LEReC cooling section

    SciTech Connect

    Seletskiy, S.; Blaskiewicz, M.; Fedotov, A.; Kayran, D.; Kewisch, J.; Michnoff, R.; Pinayev, I.

    2016-09-23

    We considered the steps required to align the electron beam trajectory through the LEReC cooling section. We devised a detailed procedure for the beam-based alignment of the cooling section solenoids. We showed that it is critical to have an individual control of each CS solenoid current. Finally, we modeled the alignment procedure and showed that with two BPM fitting the solenoid shift can be measured with 40 um accuracy and the solenoid inclination can be measured with 30 urad accuracy. These accuracies are well within the tolerances of the cooling section solenoid alignment.

  17. Strategies for active alignment of lenses

    NASA Astrophysics Data System (ADS)

    Langehanenberg, Patrik; Heinisch, Josef; Wilde, Chrisitan; Hahne, Felix; Lüerß, Bernd

    2015-10-01

    Today's optical systems require up-to-date assembly and joining technology. The trend of keeping dimensions as small as possible while maintaining or increasing optical imaging performance leaves little to no room for mechanical lens adjustment equipment that may remain in the final product. In this context active alignment of optical elements opens up possibilities for the fast and cost-economic manufacturing of lenses and lens assemblies with highest optical performance. Active alignment for lens manufacturing is the precise alignment of the optical axis of a lens with respect to an optical or mechanical reference axis (e.g. housing) including subsequent fixation by glue. In this contribution we will describe different approaches for active alignment and outline strengths and limitations of the different methods. Using the SmartAlign principle, highest quality cemented lenses can be manufactured without the need for high precision prealignment, while the reduction to a single alignment step greatly reduces the cycle time. The same strategies can also be applied to bonding processes. Lenses and lens groups can be aligned to both mechanical and optical axes to maximize the optical performance of a given assembly. In hybrid assemblies using both mechanical tolerances and active alignment, SmartAlign can be used to align critical lens elements anywhere inside the system for optimized total performance. Since all geometrical parameters are re-measured before each alignment, this process is especially suited for complex and time-consuming production processes where the stability of the reference axis would otherwise be critical. For highest performance, lenses can be actively aligned using up to five degrees of freedom. In this way, SmartAlign enables the production of ultra-precise mounted lenses with an alignment precision below 1 μm.

  18. Effect of mat pilates exercise on postural alignment and body composition of middle-aged women

    PubMed Central

    Lee, Hyo Taek; Oh, Hyun Ok; Han, Hui Seung; Jin, Kwang Youn; Roh, Hyo Lyun

    2016-01-01

    [Purpose] This study attempted to examine whether Pilates is an effective exercise for improving the postural alignment and health of middle-aged women. [Subjects and Methods] The participants in this study were 36 middle-aged women (20 in the experimental group, 16 in the control group). The experimental group participated in Pilates exercise sessions three times a week for 12 weeks. Body alignment and composition measurements before and after applying the Pilates exercise program were performed with a body composition analyzer and a three-dimensional scanner. [Results] Postural alignment in the sagittal and horizontal planes was enhanced in the Pilates exercise group. Trunk alignment showed correlations with body fat and muscle mass. [Conclusion] The Pilates exercises are performed symmetrically and strengthen the deep muscles. Moreover, the results showed that muscle mass was correlated with trunk postural alignment and that the proper amount of muscle is critical in maintaining trunk postural alignment. PMID:27390396

  19. Effect of mat pilates exercise on postural alignment and body composition of middle-aged women.

    PubMed

    Lee, Hyo Taek; Oh, Hyun Ok; Han, Hui Seung; Jin, Kwang Youn; Roh, Hyo Lyun

    2016-06-01

    [Purpose] This study attempted to examine whether Pilates is an effective exercise for improving the postural alignment and health of middle-aged women. [Subjects and Methods] The participants in this study were 36 middle-aged women (20 in the experimental group, 16 in the control group). The experimental group participated in Pilates exercise sessions three times a week for 12 weeks. Body alignment and composition measurements before and after applying the Pilates exercise program were performed with a body composition analyzer and a three-dimensional scanner. [Results] Postural alignment in the sagittal and horizontal planes was enhanced in the Pilates exercise group. Trunk alignment showed correlations with body fat and muscle mass. [Conclusion] The Pilates exercises are performed symmetrically and strengthen the deep muscles. Moreover, the results showed that muscle mass was correlated with trunk postural alignment and that the proper amount of muscle is critical in maintaining trunk postural alignment.

  20. Mechanism for Collective Cell Alignment in Myxococcus xanthus Bacteria.

    PubMed

    Balagam, Rajesh; Igoshin, Oleg A

    2015-08-01

    Myxococcus xanthus cells self-organize into aligned groups, clusters, at various stages of their lifecycle. Formation of these clusters is crucial for the complex dynamic multi-cellular behavior of these bacteria. However, the mechanism underlying the cell alignment and clustering is not fully understood. Motivated by studies of clustering in self-propelled rods, we hypothesized that M. xanthus cells can align and form clusters through pure mechanical interactions among cells and between cells and substrate. We test this hypothesis using an agent-based simulation framework in which each agent is based on the biophysical model of an individual M. xanthus cell. We show that model agents, under realistic cell flexibility values, can align and form cell clusters but only when periodic reversals of cell directions are suppressed. However, by extending our model to introduce the observed ability of cells to deposit and follow slime trails, we show that effective trail-following leads to clusters in reversing cells. Furthermore, we conclude that mechanical cell alignment combined with slime-trail-following is sufficient to explain the distinct clustering behaviors observed for wild-type and non-reversing M. xanthus mutants in recent experiments. Our results are robust to variation in model parameters, match the experimentally observed trends and can be applied to understand surface motility patterns of other bacterial species.

  1. Mechanism for Collective Cell Alignment in Myxococcus xanthus Bacteria

    PubMed Central

    Balagam, Rajesh; Igoshin, Oleg A.

    2015-01-01

    Myxococcus xanthus cells self-organize into aligned groups, clusters, at various stages of their lifecycle. Formation of these clusters is crucial for the complex dynamic multi-cellular behavior of these bacteria. However, the mechanism underlying the cell alignment and clustering is not fully understood. Motivated by studies of clustering in self-propelled rods, we hypothesized that M. xanthus cells can align and form clusters through pure mechanical interactions among cells and between cells and substrate. We test this hypothesis using an agent-based simulation framework in which each agent is based on the biophysical model of an individual M. xanthus cell. We show that model agents, under realistic cell flexibility values, can align and form cell clusters but only when periodic reversals of cell directions are suppressed. However, by extending our model to introduce the observed ability of cells to deposit and follow slime trails, we show that effective trail-following leads to clusters in reversing cells. Furthermore, we conclude that mechanical cell alignment combined with slime-trail-following is sufficient to explain the distinct clustering behaviors observed for wild-type and non-reversing M. xanthus mutants in recent experiments. Our results are robust to variation in model parameters, match the experimentally observed trends and can be applied to understand surface motility patterns of other bacterial species. PMID:26308508

  2. On the alignment of shapes represented by Fourier descriptors

    NASA Astrophysics Data System (ADS)

    Sjöstrand, Karl; Ericsson, Anders; Larsen, Rasmus

    2006-03-01

    The representation of shapes by Fourier descriptors is a time-honored technique that has received relatively little attention lately. Nevertheless, it has its benefits and is suitable for describing a range of medical structures in two dimensions. Delineations in medical applications often consist of continuous outlines of structures, where no information of correspondence between samples exist. In this article, we discuss a Euclidean alignment method that works directly with the functional representation of Fourier descriptors, and that is optimal in a least-squares sense. With corresponding starting points, the alignment of one shape onto another consists of a single expression. If the starting points are arbitrary, we present a simple algorithm to bring a set of shapes into correspondence. Results are given for three different data sets; 62 outlines of the corpus callosum brain structure, 61 outlines of the brain ventricles, and 50 outlines of the right lung. The results show that even though starting points, translations, rotations and scales have been randomized, the alignment succeeds in all cases. As an application of the proposed method, we show how high-quality shape models represented by common landmarks can be constructed in an automatic fashion. If the aligned Fourier descriptors are inverse transformed from the frequency domain to the spatial domain, a set of roughly aligned landmarks are obtained. The positions of these are then adjusted along the contour of the objects using the minimum description length criterion, producing ample correspondences. Results on this are also presented for all three data sets.

  3. Controlled production of aligned-nanotube bundles

    NASA Astrophysics Data System (ADS)

    Terrones, M.; Grobert, N.; Olivares, J.; Zhang, J. P.; Terrones, H.; Kordatos, K.; Hsu, W. K.; Hare, J. P.; Townsend, P. D.; Prassides, K.; Cheetham, A. K.; Kroto, H. W.; Walton, D. R. M.

    1997-07-01

    Carbon nanotubes might be usefully employed in nanometre-scale engineering and electronics. Electrical conductivity measurements on the bulk material, on individual multi-walled and single-walled nanotubes and on bundles of single-walled nanotubes have revealed that they may behave as metallic, insulating or semiconducting nanowires, depending on the method of production-which controls the degree of graphitization, the helicity and the diameter. Measurements of Young's modulus show that single nanotubes are stiffer than commercial carbon fibres. Methods commonly used to generate nanotubes-carbon-arc discharge techniques, catalytic pyrolysis of hydrocarbons and condensed-phase electrolysis-generally suffer from the drawbacks that polyhedral particles are also formed and that the dimensions of the nanotubes are highly variable. Here we describe a method for generating aligned carbon nanotubes by pyrolysis of 2-amino-4,6-dichloro-s-triazine over thin films of a cobalt catalyst patterned on a silica substrate by laser etching. The use of a patterned catalyst apparently encourages the formation of aligned nanotubes. The method offers control over length (up to about 50μm) and fairly uniform diameters (30-50nm), as well as producing nanotubes in high yield, uncontaminated by polyhedral particles.

  4. Measuring alignment of loading fixture

    DOEpatents

    Scavone, Donald W.

    1989-01-01

    An apparatus and method for measuring the alignment of a clevis and pin type loading fixture for compact tension specimens include a pair of substantially identical flat loading ligaments. Each loading ligament has two apertures for the reception of a respective pin of the loading fixture and a thickness less than one-half of a width of the clevis opening. The pair of loading ligaments are mounted in the clevis openings at respective sides thereof. The loading ligaments are then loaded by the pins of the loading fixture and the strain in each loading ligament is measured. By comparing the relative strain of each loading ligament, the alignment of the loading fixture is determined. Preferably, a suitable strain gage device is located at each longitudinal edge of a respective loading ligament equidistant from the two apertures in order to determine the strain thereat and hence the strain of each ligament. The loading ligaments are made substantially identical by jig grinding the loading ligaments as a matched set. Each loading ligament can also be individually calibrated prior to the measurement.

  5. Vertically aligned liquid crystals on a {gamma}-Al{sub 2}O{sub 3} alignment film using ion-beam irradiation

    SciTech Connect

    Park, Hong-Gyu; Kim, Young-Hwan; Oh, Byeong-Yun; Lee, Won-Kyu; Kim, Byoung-Yong; Seo, Dae-Shik; Hwang, Jeong-Yeon

    2008-12-08

    Using ion-beam (IB) irradiation, liquid crystals (LCs) were vertically aligned (VA) on a {gamma}-Al{sub 2}O{sub 3} alignment film. Atomic-layer deposition was used to orient the LCs on high-quality {gamma}-Al{sub 2}O{sub 3} alignment films. The LC molecule orientation indicates the vertical direction of the atomic-layer-deposited {gamma}-Al{sub 2}O{sub 3} alignment films. X-ray photoelectron spectroscopy showed that IB irradiation changed the chemical structure, shifting the Al-O binding energy and altering the Al-O bonding intensity. The low-voltage transmittance characteristics of the VA LC displays on the {gamma}-Al{sub 2}O{sub 3} alignment films were also measured, showing reduced voltage and power requirements.

  6. Mobile and replicated alignment of arrays in data-parallel programs

    NASA Technical Reports Server (NTRS)

    Chatterjee, Siddhartha; Gilbert, John R.; Schreiber, Robert

    1993-01-01

    When a data-parallel language like FORTRAN 90 is compiled for a distributed-memory machine, aggregate data objects (such as arrays) are distributed across the processor memories. The mapping determines the amount of residual communication needed to bring operands of parallel operations into alignment with each other. A common approach is to break the mapping into two stages: first, an alignment that maps all the objects to an abstract template, and then a distribution that maps the template to the processors. We solve two facets of the problem of finding alignments that reduce residual communication: we determine alignments that vary in loops, and objects that should have replicated alignments. We show that loop-dependent mobile alignment is sometimes necessary for optimum performance, and we provide algorithms with which a compiler can determine good mobile alignments for objects within do loops. We also identify situations in which replicated alignment is either required by the program itself (via spread operations) or can be used to improve performance. We propose an algorithm based on network flow that determines which objects to replicate so as to minimize the total amount of broadcast communication in replication. This work on mobile and replicated alignment extends our earlier work on determining static alignment.

  7. AlexSys: a knowledge-based expert system for multiple sequence alignment construction and analysis.

    PubMed

    Aniba, Mohamed Radhouene; Poch, Olivier; Marchler-Bauer, Aron; Thompson, Julie Dawn

    2010-10-01

    Multiple sequence alignment (MSA) is a cornerstone of modern molecular biology and represents a unique means of investigating the patterns of conservation and diversity in complex biological systems. Many different algorithms have been developed to construct MSAs, but previous studies have shown that no single aligner consistently outperforms the rest. This has led to the development of a number of 'meta-methods' that systematically run several aligners and merge the output into one single solution. Although these methods generally produce more accurate alignments, they are inefficient because all the aligners need to be run first and the choice of the best solution is made a posteriori. Here, we describe the development of a new expert system, AlexSys, for the multiple alignment of protein sequences. AlexSys incorporates an intelligent inference engine to automatically select an appropriate aligner a priori, depending only on the nature of the input sequences. The inference engine was trained on a large set of reference multiple alignments, using a novel machine learning approach. Applying AlexSys to a test set of 178 alignments, we show that the expert system represents a good compromise between alignment quality and running time, making it suitable for high throughput projects. AlexSys is freely available from http://alnitak.u-strasbg.fr/∼aniba/alexsys.

  8. Intrinsic alignments in redMaPPer clusters - I. Central galaxy alignments and angular segregation of satellites

    NASA Astrophysics Data System (ADS)

    Huang, Hung-Jin; Mandelbaum, Rachel; Freeman, Peter E.; Chen, Yen-Chi; Rozo, Eduardo; Rykoff, Eli; Baxter, Eric J.

    2016-11-01

    The shapes of cluster central galaxies are not randomly oriented, but rather exhibit coherent alignments with the shapes of their parent clusters as well as with the surrounding large-scale structures. In this work, we aim to identify the galaxy and cluster quantities that most strongly predict the central galaxy alignment phenomenon among a large parameter space with a sample of 8237 clusters and 94 817 members within 0.1 < z < 0.35, based on the red-sequence Matched-filter Probabilistic Percolation cluster catalogue constructed from the Sloan Digital Sky Survey. We first quantify the alignment between the projected central galaxy shapes and the distribution of member satellites, to understand what central galaxy and cluster properties most strongly correlate with these alignments. Next, we investigate the angular segregation of satellites with respect to their central galaxy major axis directions, to identify the satellite properties that most strongly predict their angular segregation. We find that central galaxies are more aligned with their member galaxy distributions in clusters that are more elongated and have higher richness, and for central galaxies with larger physical size, higher luminosity and centring probability, and redder colour. Satellites with redder colour, higher luminosity, located closer to the central galaxy, and with smaller ellipticity show a stronger angular segregation towards their central galaxy major axes. Finally, we provide physical explanations for some of the identified correlations, and discuss the connection to theories of central galaxy alignments, the impact of primordial alignments with tidal fields, and the importance of anisotropic accretion.

  9. Intrinsic alignments in redMaPPer clusters – I. Central galaxy alignments and angular segregation of satellites

    DOE PAGES

    Huang, Hung -Jin; Mandelbaum, Rachel; Freeman, Peter E.; ...

    2016-08-11

    The shapes of cluster central galaxies are not randomly oriented, but rather exhibit coherent alignments with the shapes of their parent clusters as well as with the surrounding large-scale structures. In this work, we aim to identify the galaxy and cluster quantities that most strongly predict the central galaxy alignment phenomenon among a large parameter space with a sample of 8237 clusters and 94 817 members within 0.1 < z < 0.35, based on the red-sequence Matched-filter Probabilistic Percolation cluster catalogue constructed from the Sloan Digital Sky Survey. We first quantify the alignment between the projected central galaxy shapes andmore » the distribution of member satellites, to understand what central galaxy and cluster properties most strongly correlate with these alignments. Next, we investigate the angular segregation of satellites with respect to their central galaxy major axis directions, to identify the satellite properties that most strongly predict their angular segregation. We find that central galaxies are more aligned with their member galaxy distributions in clusters that are more elongated and have higher richness, and for central galaxies with larger physical size, higher luminosity and centring probability, and redder colour. Satellites with redder colour, higher luminosity, located closer to the central galaxy, and with smaller ellipticity show a stronger angular segregation towards their central galaxy major axes. Lastly, we provide physical explanations for some of the identified correlations, and discuss the connection to theories of central galaxy alignments, the impact of primordial alignments with tidal fields, and the importance of anisotropic accretion.« less

  10. Intrinsic alignments in redMaPPer clusters – I. Central galaxy alignments and angular segregation of satellites

    SciTech Connect

    Huang, Hung -Jin; Mandelbaum, Rachel; Freeman, Peter E.; Chen, Yen -Chi; Rozo, Eduardo; Rykoff, Eli; Baxter, Eric J.

    2016-08-11

    The shapes of cluster central galaxies are not randomly oriented, but rather exhibit coherent alignments with the shapes of their parent clusters as well as with the surrounding large-scale structures. In this work, we aim to identify the galaxy and cluster quantities that most strongly predict the central galaxy alignment phenomenon among a large parameter space with a sample of 8237 clusters and 94 817 members within 0.1 < z < 0.35, based on the red-sequence Matched-filter Probabilistic Percolation cluster catalogue constructed from the Sloan Digital Sky Survey. We first quantify the alignment between the projected central galaxy shapes and the distribution of member satellites, to understand what central galaxy and cluster properties most strongly correlate with these alignments. Next, we investigate the angular segregation of satellites with respect to their central galaxy major axis directions, to identify the satellite properties that most strongly predict their angular segregation. We find that central galaxies are more aligned with their member galaxy distributions in clusters that are more elongated and have higher richness, and for central galaxies with larger physical size, higher luminosity and centring probability, and redder colour. Satellites with redder colour, higher luminosity, located closer to the central galaxy, and with smaller ellipticity show a stronger angular segregation towards their central galaxy major axes. Lastly, we provide physical explanations for some of the identified correlations, and discuss the connection to theories of central galaxy alignments, the impact of primordial alignments with tidal fields, and the importance of anisotropic accretion.

  11. ALIGNMENT OF SUPERMASSIVE BLACK HOLE BINARY ORBITS AND SPINS

    SciTech Connect

    Miller, M. Coleman; Krolik, Julian H.

    2013-09-01

    Recent studies of accretion onto supermassive black hole binaries suggest that much, perhaps most, of the matter eventually accretes onto one hole or the other. If so, then for binaries whose inspiral from {approx}1 pc to {approx}10{sup -3}-10{sup -2} pc is driven by interaction with external gas, both the binary orbital axis and the individual black hole spins can be reoriented by angular momentum exchange with this gas. Here we show that, unless the binary mass ratio is far from unity, the spins of the individual holes align with the binary orbital axis in a time {approx}few-100 times shorter than the binary orbital axis aligns with the angular momentum direction of the incoming circumbinary gas; the spin of the secondary aligns more rapidly than that of the primary by a factor {approx}(m{sub 1}/m{sub 2}){sup 1/2} > 1. Thus the binary acts as a stabilizing agent, so that for gas-driven systems, the black hole spins are highly likely to be aligned (or counteraligned if retrograde accretion is common) with each other and with the binary orbital axis. This alignment can significantly reduce the recoil speed resulting from subsequent black hole merger.

  12. Graphics processing unit-based alignment of protein interaction networks.

    PubMed

    Xie, Jiang; Zhou, Zhonghua; Ma, Jin; Xiang, Chaojuan; Nie, Qing; Zhang, Wu

    2015-08-01

    Network alignment is an important bridge to understanding human protein-protein interactions (PPIs) and functions through model organisms. However, the underlying subgraph isomorphism problem complicates and increases the time required to align protein interaction networks (PINs). Parallel computing technology is an effective solution to the challenge of aligning large-scale networks via sequential computing. In this study, the typical Hungarian-Greedy Algorithm (HGA) is used as an example for PIN alignment. The authors propose a HGA with 2-nearest neighbours (HGA-2N) and implement its graphics processing unit (GPU) acceleration. Numerical experiments demonstrate that HGA-2N can find alignments that are close to those found by HGA while dramatically reducing computing time. The GPU implementation of HGA-2N optimises the parallel pattern, computing mode and storage mode and it improves the computing time ratio between the CPU and GPU compared with HGA when large-scale networks are considered. By using HGA-2N in GPUs, conserved PPIs can be observed, and potential PPIs can be predicted. Among the predictions based on 25 common Gene Ontology terms, 42.8% can be found in the Human Protein Reference Database. Furthermore, a new method of reconstructing phylogenetic trees is introduced, which shows the same relationships among five herpes viruses that are obtained using other methods.

  13. ARE TIDAL EFFECTS RESPONSIBLE FOR EXOPLANETARY SPIN–ORBIT ALIGNMENT?

    SciTech Connect

    Li, Gongjie; Winn, Joshua N.

    2016-02-10

    The obliquities of planet-hosting stars are clues about the formation of planetary systems. Previous observations led to the hypothesis that for close-in giant planets, spin–orbit alignment is enforced by tidal interactions. Here, we examine two problems with this hypothesis. First, Mazeh and coworkers recently used a new technique—based on the amplitude of starspot-induced photometric variability—to conclude that spin–orbit alignment is common even for relatively long-period planets, which would not be expected if tides were responsible. We re-examine the data and find a statistically significant correlation between photometric variability and planetary orbital period that is qualitatively consistent with tidal interactions. However it is still difficult to explain quantitatively, as it would require tides to be effective for periods as long as tens of days. Second, Rogers and Lin argued against a particular theory for tidal re-alignment by showing that initially retrograde systems would fail to be re-aligned, in contradiction with the observed prevalence of prograde systems. We investigate a simple model that overcomes this problem by taking into account the dissipation of inertial waves and the equilibrium tide, as well as magnetic braking. We identify a region of parameter space where re-alignment can be achieved, but it only works for close-in giant planets, and requires some fine tuning. Thus, while we find both problems to be more nuanced than they first appeared, the tidal model still has serious shortcomings.

  14. Alignment of Supermassive Black Hole Binary Orbits and Spins

    NASA Astrophysics Data System (ADS)

    Miller, M. Coleman; Krolik, Julian H.

    2013-09-01

    Recent studies of accretion onto supermassive black hole binaries suggest that much, perhaps most, of the matter eventually accretes onto one hole or the other. If so, then for binaries whose inspiral from ~1 pc to ~10-3-10-2 pc is driven by interaction with external gas, both the binary orbital axis and the individual black hole spins can be reoriented by angular momentum exchange with this gas. Here we show that, unless the binary mass ratio is far from unity, the spins of the individual holes align with the binary orbital axis in a time ~few-100 times shorter than the binary orbital axis aligns with the angular momentum direction of the incoming circumbinary gas; the spin of the secondary aligns more rapidly than that of the primary by a factor ~(m 1/m 2)1/2 > 1. Thus the binary acts as a stabilizing agent, so that for gas-driven systems, the black hole spins are highly likely to be aligned (or counteraligned if retrograde accretion is common) with each other and with the binary orbital axis. This alignment can significantly reduce the recoil speed resulting from subsequent black hole merger.

  15. Preferential alignment of birefringent tissue measured with polarization sensitive techniques

    NASA Astrophysics Data System (ADS)

    Ramella-Roman, J. C.; Ruiz, T.; Ghassemi, P.; Travis, T. E.; Shupp, J. W.; Chue-Sang, J.; Bai, Y.

    2015-02-01

    Assessing collagen alignment is of interest when evaluating a therapeutic strategy and evaluating its outcome in scar management. In this work we introduce a theoretical and experimental methodology for the quantification of collagen and birefringent media alignment based on polarized light transport. The technique relies on the fact that these materials exhibit directional anisotropy. A polarized Monte Carlo model and a spectro-polarimetric imaging system were devised to predict and measure the impact of birefringence on an impinging polarized light beam. Experiments conducted on birefringent phantoms, and biological samples consisting of highly packed parallel birefringent fibers, showed a good agreement with the analytical results.

  16. Automated interferometric alignment system for paraboloidal mirrors

    DOEpatents

    Maxey, L.C.

    1993-09-28

    A method is described for a systematic method of interpreting interference fringes obtained by using a corner cube retroreflector as an alignment aid when aligning a paraboloid to a spherical wavefront. This is applicable to any general case where such alignment is required, but is specifically applicable in the case of aligning an autocollimating test using a diverging beam wavefront. In addition, the method provides information which can be systematically interpreted such that independent information about pitch, yaw and focus errors can be obtained. Thus, the system lends itself readily to automation. Finally, although the method is developed specifically for paraboloids, it can be seen to be applicable to a variety of other aspheric optics when applied in combination with a wavefront corrector that produces a wavefront which, when reflected from the correctly aligned aspheric surface will produce a collimated wavefront like that obtained from the paraboloid when it is correctly aligned to a spherical wavefront. 14 figures.

  17. Optimizing parameters on alignment of PCL/PGA nanofibrous scaffold: An artificial neural networks approach.

    PubMed

    Paskiabi, Farnoush Asghari; Mirzaei, Esmaeil; Amani, Amir; Shokrgozar, Mohammad Ali; Saber, Reza; Faridi-Majidi, Reza

    2015-11-01

    This paper proposes an artificial neural networks approach to finding the effects of electrospinning parameters on alignment of poly(ɛ-caprolactone)/poly(glycolic acid) blend nanofibers. Four electrospinning parameters, namely total polymer concentration, working distance, drum speed and applied voltage were considered as input and the standard deviation of the angles of nanofibers, introducing fibers alignments, as the output of the model. The results demonstrated that drum speed and applied voltage are two critical factors influencing nanofibers alignment, however their effect are entirely interdependent. Their effects also are not independent of other electrospinning parameters. In obtaining aligned electrospun nanofibers, the concentration and working distance can also be effective. In vitro cell culture study on random and aligned nanofibers showed directional growth of cells on aligned fibers.

  18. Chaotic inflation with kinetic alignment of axion fields

    NASA Astrophysics Data System (ADS)

    Bachlechner, Thomas C.; Dias, Mafalda; Frazer, Jonathan; McAllister, Liam

    2015-01-01

    N-flation is a radiatively stable scenario for chaotic inflation in which the displacements of N ≫1 axions with decay constants f1≤…≤fNshow that mixing in the axion kinetic term generically leads to the phenomenon of kinetic alignment, allowing for effective displacements as large as √{N }fN≥fPy, even if f1,…,fN -1 are arbitrarily small. At the level of kinematics, the necessary alignment occurs with very high probability, because of eigenvector delocalization. We present conditions under which inflation can take place along an aligned direction. Our construction sharply reduces the challenge of realizing N-flation in string theory.

  19. Linguistic alignment in adults with and without Asperger's syndrome.

    PubMed

    Slocombe, Katie E; Alvarez, Ivan; Branigan, Holly P; Jellema, Tjeerd; Burnett, Hollie G; Fischer, Anja; Li, Yan Hei; Garrod, Simon; Levita, Liat

    2013-06-01

    Individuals with Asperger's syndrome (AS) often have difficulties with social interactions and conversations. We investigated if these difficulties could be attributable to a deficit in the ability to linguistically converge with an interlocutor, which is posited to be important for successful communication. To that end, participants completed two cooperative tasks with a confederate, which allowed us to measure linguistic alignment with the confederate in terms of lexical choice, syntactic structure and spatial frame of reference. There was no difference in the performance of individuals with AS and matched controls and both groups showed significant alignment with the confederate at all three levels. We conclude that linguistic alignment is intact in adults with AS engaged in structured, goal-directed social interactions.

  20. Structural alignment of RNA with triple helix structure.

    PubMed

    Wong, Thomas K F; Yiu, S M

    2012-04-01

    Structural alignment is useful in identifying members of ncRNAs. Existing tools are all based on the secondary structures of the molecules. There is evidence showing that tertiary interactions (the interaction between a single-stranded nucleotide and a base-pair) in triple helix structures are critical in some functions of ncRNAs. In this article, we address the problem of structural alignment of RNAs with the triple helix. We provide a formal definition to capture a simplified model of a triple helix structure, then develop an algorithm of O(mn(3)) time to align a query sequence (of length m) with known triple helix structure with a target sequence (of length n) with an unknown structure. The resulting algorithm is shown to be useful in identifying ncRNA members in a simulated genome.

  1. Magnetic alignment of plant cell microfibrils and their anisotropic elasticity

    NASA Astrophysics Data System (ADS)

    Fujimura, Yuu; Sakaida, Hidetaka; Iino, Masaaki

    2010-06-01

    The magnetic alignment of microfibrils on a single regenerated plant cell surface subjected to magnetic fields and its anisotropic cell surface area expansivity modulus (area modulus) were studied. The magnetic alignment around the equator of the cell (the polar axis parallel to the magnetic field) was confirmed by a 2-dim Fourier analysis of images from a scanning electron microscope, and these were expressed by a theoretical magnetic order parameter for anisotropic relative magnetic permeability of 3×10-27, while the microfibrils near the pole did not show any such magnetic alignment. The magnetic field anisotropically stiffened the cell surface. The stiffness around the equator was greater than that around the pole. The magnetic field dependences of the area modulus agreed with the mechanical model.

  2. The Alignment of Galaxy Structures

    NASA Astrophysics Data System (ADS)

    Biernacka, M.; Panko, E.; Bajan, K.; Godłowski, W.; Flin, P.

    2015-11-01

    We analyzed the orientation of the sample of ACO galaxy clusters. We examined the alignment in a subsample of 1056 galaxy structures taken from the Panko-Flin (2006) Catalog with known BM morphological types. We were looking for a correlation between the orientation of the cluster and the positions of neighboring clusters. The Binggeli effect (the excess of small values of the Δθ angles between the direction toward neighboring clusters and the cluster position angle) is observed, having a range up to about 45 h-1 Mpc. The strongest effect was found for elongated BM type I clusters. This is probably connected with the origins of the supergiant galaxy and with cluster formation along a long filament or plane in a supercluster.

  3. AIMFAST: Alignment Implementation for Manufacturing

    SciTech Connect

    2012-09-13

    AIMFAST is a software code used to align facets on a dish concentrator to a specific aimpoint strategy to minimize peak fluxes and maximize system optical performance. AIMFAST uses a large monitor or projections screen to display fringe patterns, and a machine vision camera to image the reflection of these patterns in the subject dish mirrors. From these images, a detailed map of surface normals can be generated and compared to design or fitted mirror shapes. This fitted comparison is then used to develop a single vector representing the orientation of the facets relative to the design orientation, and provide near-real-time adjustment information to a communicating computer. The communicating computer can display adjustments or directly interface with adjustment tools. The software for the communicating computer is specific to the implementation and is not a part of AIMFAST.

  4. IAIMFAST: Alignment Implementation for Manufacturing

    SciTech Connect

    Andraka, Charles E.

    2013-08-29

    AIMFAST is a software code used to align facets on a dish concentrator to a specific aimpoint strategy to minimize peak fluxes and maximize system optical performance. AIM FAST uses a large monitor to display fringe patterns, and a machine vision camera to image the reflection of these patterns in the subject dish mirrors. From these images, a detailed map of surface normals can be generated and compared to design or fitted mirror shapes. This fitted comparison is then used to develop a single vector representing the orientation of the facets relative to the design orientation, and provide near-real-time adjustment information to a communicating computer. The communicating computer can display adjustments or directly interface with adjustment tools.

  5. Apse-Alignment of the Uranian Rings

    NASA Technical Reports Server (NTRS)

    Mosqueira, I.; Estrada, P. R.

    2000-01-01

    An explanation of the dynamical mechanism for apse-alignment of the eccentric Uranian rings is necessary before observations can be used to determine properties such as ring masses, particle sizes, and elasticities. The leading model relies on the ring self-gravity to accomplish this task, yet it yields equilibrium masses which are not in accord with Voyager radio measurements. We explore possible solutions such that the self-gravity and the collisional terms are both involved in the process of apse-alignment. We consider limits that correspond to a hot and a cold ring, and show that pressure terms may play a significant role in the equilibrium conditions for the narrow Uranian rings. In the cold ring case, where the scale height of the ring near periapse is comparable to the ring particle size, we introduce a new pressure correction pertaining to a region of the ring where the particles are locked in their relative positions and jammed against their neighbors, and the velocity dispersion is so low that the collisions are nearly elastic. In this case, we find a solution such that the ring self-gravity maintains apse-alignment against both differential precession (m = 1 mode) and the fluid pressure. We apply this model to the Uranian alpha ring, and show that, compared to the previous self-gravity model, the mass estimate for this ring increases by an order of magnitude. In the case of a hot ring, where the scale height can reach a value as much as fifty times larger than a particle size, we find velocity dispersion profiles that result in pressure forces which act in such a way as to alter the ring equilibrium conditions, again leading to a ring mass increase of an order of magnitude; however, such a velocity dispersion profile would require a different mechanism than is currently envisioned for establishing heating/cooling balance in a finite-sized, inelastic particle ring. Finally, we introduce an important correction to the model of Chiang and Goldreich.

  6. Reconstruction of three-dimensional molecular structure from diffraction of laser-aligned molecules

    PubMed Central

    Yang, Jie; Makhija, Varun; Kumarappan, Vinod; Centurion, Martin

    2014-01-01

    Diffraction from laser-aligned molecules has been proposed as a method for determining 3-D molecular structures in the gas phase. However, existing structural retrieval algorithms are limited by the imperfect alignment in experiments and the rotational averaging in 1-D alignment. Here, we demonstrate a two-step reconstruction comprising a genetic algorithm that corrects for the imperfect alignment followed by an iterative phase retrieval method in cylindrical coordinates. The algorithm was tested with simulated diffraction patterns. We show that the full 3-D structure of trifluorotoluene, an asymmetric-top molecule, can be reconstructed with atomic resolution. PMID:26798781

  7. Handling, clamping, and alignment evaluation for multi-beam technology on Matrix1.1 platform

    NASA Astrophysics Data System (ADS)

    Lattard, Ludovic; Pradelles, Jonathan; Vergeer, Niels; Slot, Erwin; Pain, Laurent; de Jong, Erik; Torriani, Gianpaolo; Pieczulewski, Charles

    2014-04-01

    The MATRIX platform integrates new types of modules for handling and alignment capability and this represents two new and innovative aspects for multi-beam lithography. Results on performances in terms of robustness of the different modules in real manufacturing conditions, including the interface of the MATRIX platform with the SOKUDO DUO track will be reported. A new type of alignment solution was developed by MAPPER. This paper will show the first results on alignment sensor repeatability. Preliminary results on the overlay performance of the MATRIX platform will be presented and discussion will be engaged to position the MAPPER alignment concept with respect to the ITRS roadmap expectations.

  8. Tonal alignment in Irish dialects.

    PubMed

    Dalton, Martha; Chasaide, Ailbhe Ní

    2005-01-01

    A comparison of the contour alignment of nuclear and initial prenuclear accents was carried out for the Irish dialects of Gaoth Dobhair in Ulster (GD-U) and Cois Fharraige in Connaught (CF-C). This was done across conditions where the number of unstressed syllables following the nuclear and preceding the initial prenuclear accents was varied from 2-0. This tests a variable peak hypothesis prompted by findings for other languages, that peak timing drifts as a function of the number of syllables preceding (the prenuclear) and following (the nuclear) accent. These data also test a second hypothesis that the L*+H dominant accent of GD-U might be viewed as being underlyingly the same as the dominant H* or H*+L accent of the CF-C dialect. According to this realignment hypothesis, the difference between these Ulster and Connaught dialects lies in the way that the melodic tier is aligned to the segmental tier: GD-U would be viewed as having a delayed realization of the peak relative to the Connaught dialect. Results do not support the variable peak hypothesis for Irish, as in either dialect, the peak appeared to be rather fixed across the three conditions examined (though not necessarily identical for prenuclear and nuclear positions). The results also militate against the realignment hypothesis, which rather than providing a more simple unifying account, would greatly complicate it. One reason is that there is a peak timing difference between the nuclear and prenuclear accents of CF-C, not mirrored in GD-U. Furthermore, even if one were to limit consideration to a single (e.g., prenuclear) context, a simple realignment of the accents in one dialect does not generate the appropriate contour in the other.

  9. 32. VIEW TO EAST ALONG GENERAL ALIGNMENT OF PROPOSED EXTENSION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. VIEW TO EAST ALONG GENERAL ALIGNMENT OF PROPOSED EXTENSION OF EL MONTE BUSWAY FROM THIRD FLOOR OF MBE BUILDING SHOWING ROOF OF REA LOADING DOCK (Asano) - Los Angeles Union Passenger Terminal, Mail, Baggage, & Express Building, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  10. Sensitivity of double-resonance alignment magnetometers

    SciTech Connect

    Di Domenico, Gianni; Saudan, Herve; Bison, Georg; Knowles, Paul; Weis, Antoine

    2007-08-15

    We present an experimental study of the intrinsic magnetometric sensitivity of an optical or rf-frequency double-resonance magnetometer in which linearly polarized laser light is used in the optical pumping and detection processes. We show that a semiempirical model of the magnetometer can be used to describe the magnetic resonance spectra. Then, we present an efficient method to predict the optimum operating point of the magnetometer, i.e., the light power and rf Rabi frequency providing maximum magnetometric sensitivity. Finally, we apply the method to investigate the evolution of the optimum operating point with temperature. The method is very efficient to determine relaxation rates and thus allowed us to determine the three collisional disalignment cross sections for the components of the alignment tensor. Both first and second harmonic signals from the magnetometer are considered and compared.

  11. MAGSAT: Vector magnetometer absolute sensor alignment determination

    NASA Technical Reports Server (NTRS)

    Acuna, M. H.

    1981-01-01

    A procedure is described for accurately determining the absolute alignment of the magnetic axes of a triaxial magnetometer sensor with respect to an external, fixed, reference coordinate system. The method does not require that the magnetic field vector orientation, as generated by a triaxial calibration coil system, be known to better than a few degrees from its true position, and minimizes the number of positions through which a sensor assembly must be rotated to obtain a solution. Computer simulations show that accuracies of better than 0.4 seconds of arc can be achieved under typical test conditions associated with existing magnetic test facilities. The basic approach is similar in nature to that presented by McPherron and Snare (1978) except that only three sensor positions are required and the system of equations to be solved is considerably simplified. Applications of the method to the case of the MAGSAT Vector Magnetometer are presented and the problems encountered discussed.

  12. Dye alignment in luminescent solar concentrators: II. Horizontal alignment for energy harvesting in linear polarizers

    SciTech Connect

    Mulder, Carlijn L.; Reusswig, Phil D.; Beyler, A. P.; Kim, Heekyung; Rotschild, Carmel; Baldo, Marc

    2010-04-26

    We describe Linearly Polarized Luminescent Solar Concentrators (LP-LSCs) to replace conventional, purely absorptive, linear polarizers in energy harvesting applications. As a proof of concept, we align 3-(2-Benzothiazolyl)-N,N-diethylumbelliferylamine (Coumarin 6) and 4-dicyanomethyl-6-dimethylaminostiryl-4H-pyran (DCM) dye molecules linearly in the plane of the substrate using a polymerizable liquid crystal host. We show that up to 38% of the photons polarized on the long axis of the dye molecules can be coupled to the edge of the device for an LP-LSC based on Coumarin 6 with an order parameter of 0.52.

  13. DNAAlignEditor: DNA alignment editor tool

    PubMed Central

    Sanchez-Villeda, Hector; Schroeder, Steven; Flint-Garcia, Sherry; Guill, Katherine E; Yamasaki, Masanori; McMullen, Michael D

    2008-01-01

    Background With advances in DNA re-sequencing methods and Next-Generation parallel sequencing approaches, there has been a large increase in genomic efforts to define and analyze the sequence variability present among individuals within a species. For very polymorphic species such as maize, this has lead to a need for intuitive, user-friendly software that aids the biologist, often with naïve programming capability, in tracking, editing, displaying, and exporting multiple individual sequence alignments. To fill this need we have developed a novel DNA alignment editor. Results We have generated a nucleotide sequence alignment editor (DNAAlignEditor) that provides an intuitive, user-friendly interface for manual editing of multiple sequence alignments with functions for input, editing, and output of sequence alignments. The color-coding of nucleotide identity and the display of associated quality score aids in the manual alignment editing process. DNAAlignEditor works as a client/server tool having two main components: a relational database that collects the processed alignments and a user interface connected to database through universal data access connectivity drivers. DNAAlignEditor can be used either as a stand-alone application or as a network application with multiple users concurrently connected. Conclusion We anticipate that this software will be of general interest to biologists and population genetics in editing DNA sequence alignments and analyzing natural sequence variation regardless of species, and will be particularly useful for manual alignment editing of sequences in species with high levels of polymorphism. PMID:18366684

  14. Free-space optical communication alignment system

    NASA Astrophysics Data System (ADS)

    Mariola, M.; Petruccione, F.

    2016-10-01

    Optical communication systems in free space require a coarse and fine alignment system to align the receiver and transmitter. In general a coarse alignment is not entirely accurate to transmit the laser beacon in the exact direction of the visible field of the camera. During this process, some algorithms such as the raster, spiral and raster spiral scan algorithm can be used to find the spot of the laser beacon. Applications that require to transmit data in form of polarization signals, such as quantum cryptography, requires a polarisation bases alignment system to transmit and receive the photons. In this paper we present a fine alignment system using a polarised laser beacon. The system proposed was subdivided into a coarse and fine alignment system. The coarse alignment was implemented by using the GPS to acquire the geographical position of the transmitter, receiver and a reference point. The fine alignment was achieved by using a polarised laser beacon from the receiver to the transmitter and a camera located on the transmitter side. The algorithm presented was capable of excluding the background noise. Furthermore the polarisation of the laser beacon was used to align the polarisation bases of the transmitter and the receiver.

  15. Some aspects of SR beamline alignment

    NASA Astrophysics Data System (ADS)

    Gaponov, Yu. A.; Cerenius, Y.; Nygaard, J.; Ursby, T.; Larsson, K.

    2011-09-01

    Based on the Synchrotron Radiation (SR) beamline optical element-by-element alignment with analysis of the alignment results an optimized beamline alignment algorithm has been designed and developed. The alignment procedures have been designed and developed for the MAX-lab I911-4 fixed energy beamline. It has been shown that the intermediate information received during the monochromator alignment stage can be used for the correction of both monochromator and mirror without the next stages of alignment of mirror, slits, sample holder, etc. Such an optimization of the beamline alignment procedures decreases the time necessary for the alignment and becomes useful and helpful in the case of any instability of the beamline optical elements, storage ring electron orbit or the wiggler insertion device, which could result in the instability of angular and positional parameters of the SR beam. A general purpose software package for manual, semi-automatic and automatic SR beamline alignment has been designed and developed using the developed algorithm. The TANGO control system is used as the middle-ware between the stand-alone beamline control applications BLTools, BPMonitor and the beamline equipment.

  16. VIRUS spectrograph assembly and alignment procedures

    NASA Astrophysics Data System (ADS)

    Prochaska, Travis; Allen, Richard D.; Boster, Emily; DePoy, D. L.; Herbig, Benjamin; Hill, Gary J.; Lee, Hanshin; Marshall, Jennifer L.; Martin, Emily C.; Meador, William; Rheault, Jean-Philippe; Tuttle, Sarah E.; Vattiat, Brian L.

    2012-09-01

    We describe the mechanical assembly and optical alignment processes used to construct the Visual Integral-Field Replicable Unit Spectrograph (VIRUS) instrument. VIRUS is a set of 150+ optical spectrographs designed to support observations for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). To meet the instrument's manufacturing constraints, a production line will be set up to build subassemblies in parallel. To aid in the instrument's assembly and alignment, specialized fixtures and adjustment apparatuses have been developed. We describe the design and operations of the various optics alignment apparatuses, as well as the mirrors' alignment and bonding fixtures.

  17. Optimizing femorotibial alignment in high tibial osteotomy

    PubMed Central

    Rudan, John; Harrison, Mark; Simurda, Michael A

    Objective To study factors that affect femorotibial (F-T) alignment after valgus closing wedge tibial osteotomy. Study design A review of standardized standing radiographs. Femorotibial alignment was measured 1 year postoperatively for over- and under-correction. Changes in F–T alignment and in tibial plateau angle were measured. Setting An urban hospital and orthopedic clinic. Patients Eighty-two patients with osteoarthritis and varus femorotibial alignment underwent valgus closing wedge tibial osteotomy. Patients having a diagnosis of inflammatory arthritis or a prior osteotomy about the knee were excluded. Results A 1° wedge removed from the tibia resulted in an average correction of F–T alignment of 1.2°. A knee that had increased valgus orientation of the distal femur had a greater degree of correction, averaging 1.46° in F–T alignment per degree of tibial wedge. This resulted in excessive postoperative valgus alignment for some patients who had increased valgus tilt of the distal femur. Optimal F–T alignment of 6° to 14° of valgus occurred when the postoperative tibial inclination was 4° to 8° of valgus. Conclusions There was a trend for knees with increased valgus orientation of the distal femur to have greater correction in F–T alignment after tibial osteotomy, likely because of a greater opening up of the medial joint space during stance. Surgeons need to account for this in their preoperative planning. PMID:10526522

  18. High performance triboelectric nanogenerators with aligned carbon nanotubes.

    PubMed

    Wang, Huan; Shi, Mayue; Zhu, Kai; Su, Zongming; Cheng, Xiaoliang; Song, Yu; Chen, Xuexian; Liao, Zhiqiang; Zhang, Min; Zhang, Haixia

    2016-11-03

    As the essential element of a triboelectric nanogenerator (TENG), friction layers play key roles that determine the device performance, which can be enhanced by material selection and surface modification. In this work, we have embedded aligned carbon nanotubes (CNTs) on the polydimethylsiloxane (PDMS) surface as the effective dielectric layer to donate electrons. This layer not only increases the electron generation for the output, but also shows notable stretchability. The length and the properties of the aligned CNTs can be controlled precisely. Using the 40 μm CNT as an example, the fabricated CNT-PDMS TENG shows an output voltage of 150 V and a current density of 60 mA m(-2), which are 250% and 300% enhancement compared to the TENG using directly doped PDMS/multiwall carbon nanotubes, respectively. The maximum power density of this TENG reaches 4.62 W m(-2) at an external load of 30 MΩ. The TENG has demonstrated superior stability during cyclic measurement of over 12 000 cycles. Besides, the aligned CNT-PDMS film shows superhydrophobicity (154°) and good sheet resistance of 280 Ω sq(-1). This stretchable aligned CNT-PDMS film can be universally utilized as a positive triboelectric layer pairing with polymeric materials such as polyethylene terephthalate, polyimide, PDMS and polytetrafluoroethylene for TENGs. This work provides an effective method of structure design for flexible and stretchable nanogenerators.

  19. Shear alignment of a disordered lamellar mesophase.

    PubMed

    Kumaran, V; Raman, D S S

    2011-03-01

    The shear alignment of an initially disordered lamellar phase is examined using lattice Boltzmann simulations of a mesoscopic model based on a free-energy functional for the concentration modulation. For a small shear cell of width 8λ, the qualitative features of the alignment process are strongly dependent on the Schmidt number Sc=ν/D (ratio of kinematic viscosity and mass diffusion coefficient). Here, λ is the wavelength of the concentration modulation. At low Schmidt number, it is found that there is a significant initial increase in the viscosity, coinciding with the alignment of layers along the extensional axis, followed by a decrease at long times due to the alignment along the flow direction. At high Schmidt number, alignment takes place due to the breakage and reformation of layers because diffusion is slow compared to shear deformation; this results in faster alignment. The system size has a strong effect on the alignment process; perfect alignment takes place for a small systems of width 8λ and 16λ, while a larger system of width 32λ does not align completely even at long times. In the larger system, there appears to be a dynamical steady state in which the layers are not perfectly aligned--where there is a balance between the annealing of defects due to shear and the creation due to an instability of the aligned lamellar phase under shear. We observe two types of defect creation mechanisms: the buckling instability under dilation, which was reported earlier, as well as a second mechanism due to layer compression.

  20. Alignment of muscle precursor cells on the vertical edges of thick carbon nanotube films.

    PubMed

    Holt, Ian; Gestmann, Ingo; Wright, Andrew C

    2013-10-01

    The development of scaffolds and templates is an essential aspect of tissue engineering. We show that thick (>0.5 mm) vertically aligned carbon nanotube films, made by chemical vapour deposition, can be used as biocompatible substrates for the directional alignment of mouse muscle cells where the cells grow on the exposed sides of the films. Ultra high resolution scanning electron microscopy reveals that the films themselves consist mostly of small diameter (10 nm) multi-wall carbon nanotubes of wavy morphology with some single wall carbon nanotubes. Our findings show that for this alignment to occur the nanotubes must be in pristine condition. Mechanical wiping of the films to create directional alignment is detrimental to directional bioactivity. Larger areas for study have been formed from a composite of multiply stacked narrow strips of nanotubes wipe-transferred onto elastomer supports. These composite substrates appear to show a useful degree of alignment of the cells.

  1. An Analysis of Strategies for Teaching Standards-Based Lesson Plan Alignment to Preservice Teachers

    ERIC Educational Resources Information Center

    Drost, Bryan R.; Levine, Anita C.

    2015-01-01

    Research consistently shows that well-aligned lesson plans lead to better student learning outcomes. The development of these plans challenges both preservice teachers and the teacher educators who instruct them. This exploratory study examined strategies for teaching lesson plan alignment utilized by 87 teacher educators in the United States.…

  2. Retinal pigment epithelium cell alignment on nanostructured collagen matrices.

    PubMed

    Ulbrich, Stefan; Friedrichs, Jens; Valtink, Monika; Murovski, Simo; Franz, Clemens M; Müller, Daniel J; Funk, Richard H W; Engelmann, Katrin

    2011-01-01

    We investigated attachment and migration of human retinal pigment epithelial cells (primary, SV40-transfected and ARPE-19) on nanoscopically defined, two-dimensional matrices composed of parallel-aligned collagen type I fibrils. These matrices were used non-cross-linked (native) or after riboflavin/UV-A cross-linking to study cell attachment and migration by time-lapse video microscopy. Expression of collagen type I and IV, MMP-2 and of the collagen-binding integrin subunit α(2) were examined by immunofluorescence and Western blotting. SV40-RPE cells quickly attached to the nanostructured collagen matrices and aligned along the collagen fibrils. However, they disrupted both native and cross-linked collagen matrices within 5 h. Primary RPE cells aligned more slowly without destroying either native or cross-linked substrates. Compared to primary RPE cells, ARPE-19 cells showed reduced alignment but partially disrupted the matrices within 20 h after seeding. Expression of the collagen type I-binding integrin subunit α(2) was highest in SV40-RPE cells, lower in primary RPE cells and almost undetectable in ARPE-19 cells. Thus, integrin α(2) expression levels directly correlated with the degree of cell alignment in all examined RPE cell types. Specific integrin subunit α(2)-mediated matrix binding was verified by preincubation with an α(2)-function-blocking antibody, which impaired cell adhesion and alignment to varying degrees in primary and SV40-RPE cells. Since native matrices supported extended and directed primary RPE cell growth, optimizing the matrix production procedure may in the future yield nanostructured collagen matrices serving as transferable cell sheet carriers.

  3. Nanofiber alignment of a small diameter elastic electrospun scaffold

    NASA Astrophysics Data System (ADS)

    Patel, Jignesh

    Cardiovascular disease is the leading cause of death in western countries with coronary heart disease making up 50% of these deaths. As a treatment option, tissue engineered grafts have great potential. Elastic scaffolds that mimic arterial extracellular matrix (ECM) may hold the key to creating viable vascular grafts. Electrospinning is a widely used scaffold fabrication technique to engineer tubular scaffolds. In this study, we investigated how the collector rotation speed altered the nanofiber alignment which may improve mechanical characteristics making the scaffold more suitable for arterial grafts. The scaffold was fabricated from a blend of PCL/Elastin. 2D Fast Fourier Transform (FFT) image processing tool and MatLab were used to quantitatively analyze nanofiber orientation at different collector speeds (13500 to 15500 rpm). Both Image J and MatLab showed graphical peaks indicating predominant fiber orientation angles. A collector speed of 15000 rpm was found to produce the best nanofiber alignment with narrow peaks at 90 and 270 degrees, and a relative amplitude of 200. This indicates a narrow distribution of circumferentially aligned nanofibers. Collector speeds below and above 15000 rpm caused a decrease in fiber alignment with a broader orientation distribution. Uniformity of fiber diameter was also measured. Of 600 measures from the 15000 rpm scaffolds, the fiber diameter range from 500 nm to 899 nm was most prevalent. This diameter range was slightly larger than native ECM which ranges from 50 nm to 500 nm. The second most prevalent diameter range had an average of 404 nm which is within the diameter range of collagen. This study concluded that with proper electrospinning technique and collector speed, it is possible to fabricate highly aligned small diameter elastic scaffolds. Image J 2D FFT results confirmed MatLab findings for the analyses of circumferentially aligned nanofibers. In addition, MatLab analyses simplified the FFT orientation data

  4. Implementation of two-state alignment system into CXrL aligner (Poster Paper)

    NASA Astrophysics Data System (ADS)

    Chen, Guan-Jye; Bodoh, D.; Wallace, John P.; Anderson, Paul D.; Reilly, Michael T.; Nachman, Ramez; Cerrina, Franco

    1992-07-01

    We describe the implementation of the two-state alignment system into the CXrL aligner, which is developed at our Center for X-ray Lithography. The CXrL aligner is designed to expose sub 0.25 μm feature size integrated circuits. The aligner consists of a three-axes two-state alignment system for alignment error detection and a piezo based precision mechanical stage for alignment error correction. The wafer is held by a precision vacuum chuck, while the mask is held by three vacuum suction cups located around the glass ring. In the prototype, the mask to wafer relative positioning is achieved by 3 motorized stages (for gap setting) and 3 piezo-actuators (for lateral alignment). Since the optical system is designed to be located outside of the synchrotron radiation path, alignment can be performed during exposure. We present the results of the alignment system performance, such as noise equivalent displacement and alignment signal response time. An alignment signal repeatibility of much better than 3σ = 0.07μm is achieved. We also briefly describe the future evaluation of the system, such as overlay measurement of the system using verniers and SEM inspection of some specially designed patterns.

  5. Time-varying gyrocompass alignment for fiber-optic-gyro inertial navigation system with large misalignment angle

    NASA Astrophysics Data System (ADS)

    Ben, Yueyang; Li, Qian; Zhang, Yi; Huo, Liang

    2014-09-01

    Conventional strapdown gyrocompass alignment methods are based on the assumption that the fiber-optic-gyro inertial navigation system has a small azimuth misalignment angle. A large azimuth misalignment angle would lead to an extension of the alignment duration. A time-varying gyrocompass alignment method to solve this problem is provided. An appropriate parameter setting is given for the gyrocompass alignment with a large misalignment angle. Also, a proper protocol for a parametric switch is derived. Simulation and trail results show that the proposed method has better alignment performance than conventional ones, as the system has large misalignment angles.

  6. Phylogenetic Inference From Conserved sites Alignments

    SciTech Connect

    grundy, W.N.; Naylor, G.J.P.

    1999-08-15

    Molecular sequences provide a rich source of data for inferring the phylogenetic relationships among species. However, recent work indicates that even an accurate multiple alignment of a large sequence set may yield an incorrect phylogeny and that the quality of the phylogenetic tree improves when the input consists only of the highly conserved, motif regions of the alignment. This work introduces two methods of producing multiple alignments that include only the conserved regions of the initial alignment. The first method retains conserved motifs, whereas the second retains individual conserved sites in the initial alignment. Using parsimony analysis on a mitochondrial data set containing 19 species among which the phylogenetic relationships are widely accepted, both conserved alignment methods produce better phylogenetic trees than the complete alignment. Unlike any of the 19 inference methods used before to analyze this data, both methods produce trees that are completely consistent with the known phylogeny. The motif-based method employs far fewer alignment sites for comparable error rates. For a larger data set containing mitochondrial sequences from 39 species, the site-based method produces a phylogenetic tree that is largely consistent with known phylogenetic relationships and suggests several novel placements.

  7. Nonvisual Cues for Aligning to Cross Streets

    ERIC Educational Resources Information Center

    Scott, Alan C.; Barlow, Janet M.; Guth, David A.; Bentzen, Billie Louise; Cunningham, Christopher M.; Long, Richard

    2011-01-01

    Accurately aligning to a crosswalk is an important component of safe street crossing for pedestrians who are blind. Six alignment cues were evaluated in a simulated crosswalk environment in which the angle of the crosswalk was not always in line with the slope of the ramp. The effectiveness of each cue is reported and implications are discussed.…

  8. Instructional Alignment under No Child Left Behind

    ERIC Educational Resources Information Center

    Polikoff, Morgan S.

    2012-01-01

    The alignment of instruction with the content of standards and assessments is the key mediating variable separating the policy of standards-based reform (SBR) from the outcome of improved student achievement. Few studies have investigated SBR's effects on instructional alignment, and most have serious methodological limitations. This research uses…

  9. Probabilistic sequence alignment of stratigraphic records

    NASA Astrophysics Data System (ADS)

    Lin, Luan; Khider, Deborah; Lisiecki, Lorraine E.; Lawrence, Charles E.

    2014-10-01

    The assessment of age uncertainty in stratigraphically aligned records is a pressing need in paleoceanographic research. The alignment of ocean sediment cores is used to develop mutually consistent age models for climate proxies and is often based on the δ18O of calcite from benthic foraminifera, which records a global ice volume and deep water temperature signal. To date, δ18O alignment has been performed by manual, qualitative comparison or by deterministic algorithms. Here we present a hidden Markov model (HMM) probabilistic algorithm to find 95% confidence bands for δ18O alignment. This model considers the probability of every possible alignment based on its fit to the δ18O data and transition probabilities for sedimentation rate changes obtained from radiocarbon-based estimates for 37 cores. Uncertainty is assessed using a stochastic back trace recursion to sample alignments in exact proportion to their probability. We applied the algorithm to align 35 late Pleistocene records to a global benthic δ18O stack and found that the mean width of 95% confidence intervals varies between 3 and 23 kyr depending on the resolution and noisiness of the record's δ18O signal. Confidence bands within individual cores also vary greatly, ranging from ~0 to >40 kyr. These alignment uncertainty estimates will allow researchers to examine the robustness of their conclusions, including the statistical evaluation of lead-lag relationships between events observed in different cores.

  10. Galaxy Alignments: Observations and Impact on Cosmology

    NASA Astrophysics Data System (ADS)

    Kirk, Donnacha; Brown, Michael L.; Hoekstra, Henk; Joachimi, Benjamin; Kitching, Thomas D.; Mandelbaum, Rachel; Sifón, Cristóbal; Cacciato, Marcello; Choi, Ami; Kiessling, Alina; Leonard, Adrienne; Rassat, Anais; Schäfer, Björn Malte

    2015-11-01

    Galaxy shapes are not randomly oriented, rather they are statistically aligned in a way that can depend on formation environment, history and galaxy type. Studying the alignment of galaxies can therefore deliver important information about the physics of galaxy formation and evolution as well as the growth of structure in the Universe. In this review paper we summarise key measurements of galaxy alignments, divided by galaxy type, scale and environment. We also cover the statistics and formalism necessary to understand the observations in the literature. With the emergence of weak gravitational lensing as a precision probe of cosmology, galaxy alignments have taken on an added importance because they can mimic cosmic shear, the effect of gravitational lensing by large-scale structure on observed galaxy shapes. This makes galaxy alignments, commonly referred to as intrinsic alignments, an important systematic effect in weak lensing studies. We quantify the impact of intrinsic alignments on cosmic shear surveys and finish by reviewing practical mitigation techniques which attempt to remove contamination by intrinsic alignments.

  11. The GEM Detector projective alignment simulation system

    SciTech Connect

    Wuest, C.R.; Belser, F.C.; Holdener, F.R.; Roeben, M.D.; Paradiso, J.A.; Mitselmakher, G.; Ostapchuk, A.; Pier-Amory, J.

    1993-07-09

    Precision position knowledge (< 25 microns RMS) of the GEM Detector muon system at the Superconducting Super Collider Laboratory (SSCL) is an important physics requirement necessary to minimize sagitta error in detecting and tracking high energy muons that are deflected by the magnetic field within the GEM Detector. To validate the concept of the sagitta correction function determined by projective alignment of the muon detectors (Cathode Strip Chambers or CSCs), the basis of the proposed GEM alignment scheme, a facility, called the ``Alignment Test Stand`` (ATS), is being constructed. This system simulates the environment that the CSCs and chamber alignment systems are expected to experience in the GEM Detector, albeit without the 0.8 T magnetic field and radiation environment. The ATS experimental program will allow systematic study and characterization of the projective alignment approach, as well as general mechanical engineering of muon chamber mounting concepts, positioning systems and study of the mechanical behavior of the proposed 6 layer CSCs. The ATS will consist of a stable local coordinate system in which mock-ups of muon chambers (i.e., non-working mechanical analogs, representing the three superlayers of a selected barrel and endcap alignment tower) are implemented, together with a sufficient number of alignment monitors to overdetermine the sagitta correction function, providing a self-consistency check. This paper describes the approach to be used for the alignment of the GEM muon system, the design of the ATS, and the experiments to be conducted using the ATS.

  12. Achieving Organisational Change through Values Alignment

    ERIC Educational Resources Information Center

    Branson, Christopher M.

    2008-01-01

    Purpose: The purpose of this paper is to, first, establish the interdependency between the successful achievement of organisational change and the attainment of values alignment within an organisation's culture and then, second, to describe an effective means for attaining such values alignment. Design/methodology/approach: Literature from the…

  13. Alignment of Developments in Higher Education

    ERIC Educational Resources Information Center

    Cowan, John; George, Judith W.; Pinheiro-Torres, Andreia

    2004-01-01

    This study builds upon the concept of alignment within the curriculum (due to Biggs) and suggests, in the context of two current examples, an integrated methodology for effectively aligned development activities within universities. Higher Education institutions face important challenges. Firstly, quality enhancement of the curriculum is now an…

  14. Compositions for directed alignment of conjugated polymers

    DOEpatents

    Kim, Jinsang; Kim, Bong-Gi; Jeong, Eun Jeong

    2016-04-19

    Conjugated polymers (CPs) achieve directed alignment along an applied flow field and a dichroic ratio of as high as 16.67 in emission from well-aligned thin films and fully realized anisotropic optoelectronic properties of CPs in field-effect transistor (FET).

  15. Optical alignment of a pupil imaging spectrometer

    NASA Technical Reports Server (NTRS)

    Horchem, Stephen D.; Kohrman, Richard J.

    1989-01-01

    The GOES Sounder is a 19-channel discrete filter spectrometer with an additional channel for star sensing. This paper presents the GOES Sounder's instrument optics and compensations, alignment rationale, and alignment mechanism and sensitivities. The results of a line of sight tolerance analysis of the instrument are described, and the prealignment and instrument coregistration are addressed.

  16. Precision aligned split V-block

    DOEpatents

    George, Irwin S.

    1984-01-01

    A precision aligned split V-block for holding a workpiece during a milling operation having an expandable frame for allowing various sized workpieces to be accommodated, is easily secured directly to the mill table and having key lugs in one base of the split V-block that assures constant alignment.

  17. Partial Automated Alignment and Integration System

    NASA Technical Reports Server (NTRS)

    Kelley, Gary Wayne (Inventor)

    2014-01-01

    The present invention is a Partial Automated Alignment and Integration System (PAAIS) used to automate the alignment and integration of space vehicle components. A PAAIS includes ground support apparatuses, a track assembly with a plurality of energy-emitting components and an energy-receiving component containing a plurality of energy-receiving surfaces. Communication components and processors allow communication and feedback through PAAIS.

  18. Evaluating Content Alignment in Computerized Adaptive Testing

    ERIC Educational Resources Information Center

    Wise, Steven L.; Kingsbury, G. Gage; Webb, Norman L.

    2015-01-01

    The alignment between a test and the content domain it measures represents key evidence for the validation of test score inferences. Although procedures have been developed for evaluating the content alignment of linear tests, these procedures are not readily applicable to computerized adaptive tests (CATs), which require large item pools and do…

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

    SciTech Connect

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

    2010-06-07

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

  20. MicroRNAs Align With Accessible Sites in Target mRNAs

    PubMed Central

    Pan, Weihua; Xin, Ping; Clawson, Gary A.

    2015-01-01

    The importance of microRNAs (miRs) in control of gene expression is now clearly recognized. While individual microRNAs are thought to target hundreds of disparate mRNAs via imperfect base pairing, little is known about the characteristics of miR target sites. Here we show that the miRs can be aligned with empirically identified accessible sites in a target RNA (Cytokeratin 19, KRT), and that some of the aligned miRs functionally down-regulate KRT expression post-transcriptionally. We employed an RNase-H-based random library selection protocol to identify accessible sites in KRT RNA. We then aligned the Sanger Institute database collection of human miRs to KRT mRNA, and also aligned them using the web-based MicroInspector program. Most miRs aligned with the accessible sites identified empirically; those not aligned with the empirically identified sites also functioned effectively in RNase-H-based assays. Similar results were obtained with a second target RNA (Mammoglobin). Transient transfection assays established that some of the miRs which aligned with KRT significantly down-regulated it at the protein level, with no effect on RNA level. The functionally effective miRs aligned within the coding region of KRT, whereas a number of miRs which aligned with the 3′-untranslated region did not produce down-regulation. PMID:19998415

  1. Alignment-free phylogenetics and population genetics.

    PubMed

    Haubold, Bernhard

    2014-05-01

    Phylogenetics and population genetics are central disciplines in evolutionary biology. Both are based on comparative data, today usually DNA sequences. These have become so plentiful that alignment-free sequence comparison is of growing importance in the race between scientists and sequencing machines. In phylogenetics, efficient distance computation is the major contribution of alignment-free methods. A distance measure should reflect the number of substitutions per site, which underlies classical alignment-based phylogeny reconstruction. Alignment-free distance measures are either based on word counts or on match lengths, and I apply examples of both approaches to simulated and real data to assess their accuracy and efficiency. While phylogeny reconstruction is based on the number of substitutions, in population genetics, the distribution of mutations along a sequence is also considered. This distribution can be explored by match lengths, thus opening the prospect of alignment-free population genomics.

  2. Vane segment support and alignment device

    DOEpatents

    McLaurin, L.D.; Sizemore, J.D.

    1999-07-13

    A support and alignment assembly for supporting and aligning a vane segment is provided. The support and alignment assembly comprises a torque plate which defines an opening for receiving an eccentric pin and a locking end member for receiving a lock socket member. An eccentric pin adjustably supported by the torque plate opening for supporting and aligning a vane segment is provided. A lock socket member adapted to securely receive the eccentric pin and rotated therewith, and adjustably engage the torque plate locking end is provided. The lock socket member receives the eccentric pin, such that when the eccentric pin is adjusted to align the vane segment, the lock socket member engages the torque plate locking end to secure the vane segment in the desired position. 5 figs.

  3. Vane segment support and alignment device

    SciTech Connect

    McLaurin, Leroy Dixon; Sizemore, John Derek

    1999-01-01

    A support and alignment assembly for supporting and aligning a vane segment is provided. The support and alignment assembly comprises a torque plate which defines an opening for receiving an eccentric pin and a locking end member for receiving a lock socket member. An eccentric pin adjustably supported by the torque plate opening for supporting and aligning a vane segment is provided. A lock socket member adapted to securely receive the eccentric pin and rotated therewith, and adjustably engage the torque plate locking end is provided. The lock socket member receives the eccentric pin, such that when the eccentric pin is adjusted to align the vane segment, the lock socket member engages the torque plate locking end to secure the vane segment in the desired position.

  4. Aligning Greek-English parallel texts

    NASA Astrophysics Data System (ADS)

    Galiotou, Eleni; Koronakis, George; Lazari, Vassiliki

    2015-02-01

    In this paper, we discuss issues concerning the alignment of parallel texts written in languages with different alphabets based on an experiment of aligning texts from the proceedings of the European Parliament in Greek and English. First, we describe our implementation of the k-vec algorithm and its application to the bilingual corpus. Then the output of the algorithm is used as a starting point for an alignment procedure at a sentence level which also takes into account mark-ups of meta-information. The results of the implementation are compared to those of the application of the Church and Gale alignment algorithm on the Europarl corpus. The conclusions of this comparison can give useful insights as for the efficiency of alignment algorithms when applied to the particular bilingual corpus.

  5. Automated interferometric alignment system for paraboloidal mirrors

    DOEpatents

    Maxey, L. Curtis

    1993-01-01

    A method is described for a systematic method of interpreting interference fringes obtained by using a corner cube retroreflector as an alignment aid when aigning a paraboloid to a spherical wavefront. This is applicable to any general case where such alignment is required, but is specifically applicable in the case of aligning an autocollimating test using a diverging beam wavefront. In addition, the method provides information which can be systematically interpreted such that independent information about pitch, yaw and focus errors can be obtained. Thus, the system lends itself readily to automation. Finally, although the method is developed specifically for paraboloids, it can be seen to be applicable to a variety of other aspheric optics when applied in combination with a wavefront corrector that produces a wavefront which, when reflected from the correctly aligned aspheric surface will produce a collimated wavefront like that obtained from the paraboloid when it is correctly aligned to a spherical wavefront.

  6. Array tomography: semiautomated image alignment.

    PubMed

    Micheva, Kristina D; O'Rourke, Nancy; Busse, Brad; Smith, Stephen J

    2010-11-01

    Array tomography is a volumetric microscopy method based on physical serial sectioning. Ultrathin sections of a plastic-embedded tissue are cut using an ultramicrotome, bonded in an ordered array to a glass coverslip, stained as desired, and imaged. The resulting two-dimensional image tiles can then be reconstructed computationally into three-dimensional volume images for visualization and quantitative analysis. The minimal thickness of individual sections permits high-quality rapid staining and imaging, whereas the array format allows reliable and convenient section handling, staining, and automated imaging. Also, the physical stability of the arrays permits images to be acquired and registered from repeated cycles of staining, imaging, and stain elution, as well as from imaging using multiple modalities (e.g., fluorescence and electron microscopy). Array tomography makes it possible to visualize and quantify previously inaccessible features of tissue structure and molecular architecture. However, careful preparation of the tissue is essential for successful array tomography; these steps can be time-consuming and require some practice to perfect. Successful array tomography requires that the captured images be properly stacked and aligned, and the software to achieve these ends is freely available. This protocol describes the construction of volumetric image stacks from images of fluorescently labeled arrays for three-dimensional image visualization, analysis, and archiving.

  7. Recursions for statistical multiple alignment

    PubMed Central

    Hein, Jotun; Jensen, Jens Ledet; Pedersen, Christian N. S.

    2003-01-01

    Algorithms are presented that allow the calculation of the probability of a set of sequences related by a binary tree that have evolved according to the Thorne–Kishino–Felsenstein model for a fixed set of parameters. The algorithms are based on a Markov chain generating sequences and their alignment at nodes in a tree. Depending on whether the complete realization of this Markov chain is decomposed into the first transition and the rest of the realization or the last transition and the first part of the realization, two kinds of recursions are obtained that are computationally similar but probabilistically different. The running time of the algorithms is \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}O({\\Pi}_{i}^{d}=1~L_{i})\\end{equation*}\\end{document}, where Li is the length of the ith observed sequences and d is the number of sequences. An alternative recursion is also formulated that uses only a Markov chain involving the inner nodes of a tree. PMID:14657378

  8. Distributed sequence alignment applications for the public computing architecture.

    PubMed

    Pellicer, S; Chen, G; Chan, K C C; Pan, Y

    2008-03-01

    The public computer architecture shows promise as a platform for solving fundamental problems in bioinformatics such as global gene sequence alignment and data mining with tools such as the basic local alignment search tool (BLAST). Our implementation of these two problems on the Berkeley open infrastructure for network computing (BOINC) platform demonstrates a runtime reduction factor of 1.15 for sequence alignment and 16.76 for BLAST. While the runtime reduction factor of the global gene sequence alignment application is modest, this value is based on a theoretical sequential runtime extrapolated from the calculation of a smaller problem. Because this runtime is extrapolated from running the calculation in memory, the theoretical sequential runtime would require 37.3 GB of memory on a single system. With this in mind, the BOINC implementation not only offers the reduced runtime, but also the aggregation of the available memory of all participant nodes. If an actual sequential run of the problem were compared, a more drastic reduction in the runtime would be seen due to an additional secondary storage I/O overhead for a practical system. Despite the limitations of the public computer architecture, most notably in communication overhead, it represents a practical platform for grid- and cluster-scale bioinformatics computations today and shows great potential for future implementations.

  9. Using Variable-Length Aligned Fragment Pairs and an Improved Transition Function for Flexible Protein Structure Alignment.

    PubMed

    Cao, Hu; Lu, Yonggang

    2017-01-01

    With the rapid growth of known protein 3D structures in number, how to efficiently compare protein structures becomes an essential and challenging problem in computational structural biology. At present, many protein structure alignment methods have been developed. Among all these methods, flexible structure alignment methods are shown to be superior to rigid structure alignment methods in identifying structure similarities between proteins, which have gone through conformational changes. It is also found that the methods based on aligned fragment pairs (AFPs) have a special advantage over other approaches in balancing global structure similarities and local structure similarities. Accordingly, we propose a new flexible protein structure alignment method based on variable-length AFPs. Compared with other methods, the proposed method possesses three main advantages. First, it is based on variable-length AFPs. The length of each AFP is separately determined to maximally represent a local similar structure fragment, which reduces the number of AFPs. Second, it uses local coordinate systems, which simplify the computation at each step of the expansion of AFPs during the AFP identification. Third, it decreases the number of twists by rewarding the situation where nonconsecutive AFPs share the same transformation in the alignment, which is realized by dynamic programming with an improved transition function. The experimental data show that compared with FlexProt, FATCAT, and FlexSnap, the proposed method can achieve comparable results by introducing fewer twists. Meanwhile, it can generate results similar to those of the FATCAT method in much less running time due to the reduced number of AFPs.

  10. A sequence alignment-independent method for protein classification.

    PubMed

    Vries, John K; Munshi, Rajan; Tobi, Dror; Klein-Seetharaman, Judith; Benos, Panayiotis V; Bahar, Ivet

    2004-01-01

    Annotation of the rapidly accumulating body of sequence data relies heavily on the detection of remote homologues and functional motifs in protein families. The most popular methods rely on sequence alignment. These include programs that use a scoring matrix to compare the probability of a potential alignment with random chance and programs that use curated multiple alignments to train profile hidden Markov models (HMMs). Related approaches depend on bootstrapping multiple alignments from a single sequence. However, alignment-based programs have limitations. They make the assumption that contiguity is conserved between homologous segments, which may not be true in genetic recombination or horizontal transfer. Alignments also become ambiguous when sequence similarity drops below 40%. This has kindled interest in classification methods that do not rely on alignment. An approach to classification without alignment based on the distribution of contiguous sequences of four amino acids (4-grams) was developed. Interest in 4-grams stemmed from the observation that almost all theoretically possible 4-grams (20(4)) occur in natural sequences and the majority of 4-grams are uniformly distributed. This implies that the probability of finding identical 4-grams by random chance in unrelated sequences is low. A Bayesian probabilistic model was developed to test this hypothesis. For each protein family in Pfam-A and PIR-PSD, a feature vector called a probe was constructed from the set of 4-grams that best characterised the family. In rigorous jackknife tests, unknown sequences from Pfam-A and PIR-PSD were compared with the probes for each family. A classification result was deemed a true positive if the probe match with the highest probability was in first place in a rank-ordered list. This was achieved in 70% of cases. Analysis of false positives suggested that the precision might approach 85% if selected families were clustered into subsets. Case studies indicated that the 4

  11. Beam and target alignment at the National Ignition Facility using the Target Alignment Sensor (TAS)

    NASA Astrophysics Data System (ADS)

    Di Nicola, P.; Kalantar, D.; McCarville, T.; Klingmann, J.; Alvarez, S.; Lowe-Webb, R.; Lawson, J.; Datte, P.; Danforth, P.; Schneider, M.; Di Nicola, J.-M.; Jackson, J.; Orth, C.; Azevedo, S.; Tommasini, R.; Manuel, A.; Wallace, R.

    2012-10-01

    The requirements for beam and target alignment for successful ignition experiments on the National Ignition Facility (NIF) are stringent: the average of beams to the target must be within 25 μm. Beam and target alignment are achieved with the Target Alignment Sensor (TAS). The TAS is a precision optical device that is inserted into target chamber center to facilitate both beam and target alignment. It incorporates two camera views (upper/lower and side) mounted on each of two stage assemblies (jaws) to view and align the target. It also incorporates a large mirror on each of the two assemblies to reflect the alignment beams onto the upper/lower cameras for beam alignment. The TAS is located in the chamber using reference features by viewing it with two external telescope views. The two jaws are adjusted in elevation to match the desired beam and target alignment locations. For some shot setups, a sequence of TAS positions is required to achieve the full setup and alignment. In this paper we describe the TAS, the characterization of the TAS coordinates for beam and target alignment, and summarize pointing shots that demonstrate the accuracy of beam-target alignment.

  12. Proper alignment of the microscope.

    PubMed

    Rottenfusser, Rudi

    2013-01-01

    The light microscope is merely the first element of an imaging system in a research facility. Such a system may include high-speed and/or high-resolution image acquisition capabilities, confocal technologies, and super-resolution methods of various types. Yet more than ever, the proverb "garbage in-garbage out" remains a fact. Image manipulations may be used to conceal a suboptimal microscope setup, but an artifact-free image can only be obtained when the microscope is optimally aligned, both mechanically and optically. Something else is often overlooked in the quest to get the best image out of the microscope: Proper sample preparation! The microscope optics can only do its job when its design criteria are matched to the specimen or vice versa. The specimen itself, the mounting medium, the cover slip, and the type of immersion medium (if applicable) are all part of the total optical makeup. To get the best results out of a microscope, understanding the functions of all of its variable components is important. Only then one knows how to optimize these components for the intended application. Different approaches might be chosen to discuss all of the microscope's components. We decided to follow the light path which starts with the light source and ends at the camera or the eyepieces. To add more transparency to this sequence, the section up to the microscope stage was called the "Illuminating Section", to be followed by the "Imaging Section" which starts with the microscope objective. After understanding the various components, we can start "working with the microscope." To get the best resolution and contrast from the microscope, the practice of "Koehler Illumination" should be understood and followed by every serious microscopist. Step-by-step instructions as well as illustrations of the beam path in an upright and inverted microscope are included in this chapter. A few practical considerations are listed in Section 3.

  13. Daily Bone Alignment With Limited Repeat CT Correction Rivals Daily Ultrasound Alignment for Prostate Radiotherapy

    SciTech Connect

    O'Daniel, Jennifer C.; Dong Lei Zhang Lifei; Wang He; Tucker, Susan L.; Kudchadker, Rajat J.; Lee, Andrew K.; Cheung, Rex; Cox, James D.; Kuban, Deborah A.; Mohan, Radhe

    2008-05-01

    Purpose: To compare the effectiveness of daily ultrasound (US)- and computed tomography (CT)-guided alignments with an off-line correction protocol using daily bone alignment plus a correction factor for systematic internal prostate displacement (CF{sub ID}). Methods and Materials: Ten prostate cancer patients underwent CT scans three times weekly using an integrated CT-linear accelerator system, followed by alignment using US for daily radiotherapy. Intensity-modulated radiotherapy plans were designed with our current clinical margins. The treatment plan was copied onto the repeat CT images and aligned using several methods: (1) bone alignment plus CF{sub ID} after three off-line CT scans (bone+3CT), (2) bone alignment plus CF{sub ID} after six off-line CT scans (bone+6CT), (3) US alignment, and (4) CT alignment. The accuracy of the repeated US and CT measurements to determine the CF{sub ID} was compared. The target dosimetric effect was quantified. Results: The CF{sub ID} for internal systematic prostate displacements was more accurately measured with limited repeat CT scans than with US (residual error, 0.0 {+-} 0.7 mm vs. 2.0 {+-} 3.2 mm). Bone+3CT, bone+6CT, and US provided equivalent prostate and seminal vesicle dose coverage, but bone+3CT and bone+6CT produced more precise daily alignments. Daily CT alignment provided the greatest target dose coverage. Conclusion: Daily bone alignment plus CF{sub ID} for internal systematic prostate displacement provided better daily alignment precision and equivalent dose coverage compared with daily US alignment. The CF{sub ID} should be based on at least three repeat CT scans, which could be collected before the start of treatment or during the first 3 treatment days. Daily bone alignment plus CF{sub ID} provides another option for accurate prostate cancer patient positioning.

  14. Aligning Metabolic Pathways Exploiting Binary Relation of Reactions

    PubMed Central

    Zhong, Cheng; Lin, Hai Xiang; Huang, Jing

    2016-01-01

    Metabolic pathway alignment has been widely used to find one-to-one and/or one-to-many reaction mappings to identify the alternative pathways that have similar functions through different sets of reactions, which has important applications in reconstructing phylogeny and understanding metabolic functions. The existing alignment methods exhaustively search reaction sets, which may become infeasible for large pathways. To address this problem, we present an effective alignment method for accurately extracting reaction mappings between two metabolic pathways. We show that connected relation between reactions can be formalized as binary relation of reactions in metabolic pathways, and the multiplications of zero-one matrices for binary relations of reactions can be accomplished in finite steps. By utilizing the multiplications of zero-one matrices for binary relation of reactions, we efficiently obtain reaction sets in a small number of steps without exhaustive search, and accurately uncover biologically relevant reaction mappings. Furthermore, we introduce a measure of topological similarity of nodes (reactions) by comparing the structural similarity of the k-neighborhood subgraphs of the nodes in aligning metabolic pathways. We employ this similarity metric to improve the accuracy of the alignments. The experimental results on the KEGG database show that when compared with other state-of-the-art methods, in most cases, our method obtains better performance in the node correctness and edge correctness, and the number of the edges of the largest common connected subgraph for one-to-one reaction mappings, and the number of correct one-to-many reaction mappings. Our method is scalable in finding more reaction mappings with better biological relevance in large metabolic pathways. PMID:27936108

  15. Artificial field-aligned irregularities in the nightside auroral ionosphere

    NASA Astrophysics Data System (ADS)

    Blagoveshchenskaya, N.; Borisova, T.; Kornienko, V.; Leyser, T.; Rietveld, M.; Thide', B.

    The properties and behaviors of the artificial field-aligned small-scale irregularities (striations) in the nightside high latitudinal F-region in course of the Tromso ionospheric modification experiments are examined. Bistatic scatter measurements of HF diagnostic signals were carried out on the London-Tromso-St.Petersburg and Pori-Tromso-St.Petersburg paths using a Doppler spectral method. Striations act as an artificially produced target for the diagnostic HF radio waves and they are responsible for back-scattered signals. The main attention was paid to the aspect angle dependence of striations. It was found that the spectral features of the scattered signals are strongly dependent on the elevation angles of the HF heater antenna beam. The spectral power, broadening of the Doppler spectra, and median values of Doppler shift were maximal during the field-aligned direction of the HF heater antenna beam, whereas they were minimal during the vertical pointing of the HF beam. Simultaneous measurements from the EISCAT UHF incoherent scatter radar showed also the strongest heating effects in the field-aligned position. Electron temperature increases of up to 3000K (300%) induced by powerful HF pumping waves have been measured. Associated with them are the field-aligned ion outflows. Further observations of striations have been made using a narrower HF heater beam (sometimes termed "superheater"). The comparison between two HF heating experiments in a superheater mode, performed under the same geophysical conditions, also shows the strongest striations in the field-aligned position of the HF heater beam. The possible mechanisms for the directional dependence of striations are discussed.

  16. Alignment Cube with One Diffractive Face

    NASA Technical Reports Server (NTRS)

    Ohl, Raymond G.; Sampler, Henry P.; Strojny, Carl R.; Hagopian, John G.; McMann, Joseph C.

    2006-01-01

    An enhanced alignment cube has been invented for use in a confined setting (e.g., a cryogenic chamber) in which optical access may be limited to a single line of sight. Whereas traditional alignment-cube practice entails the use of two theodolites aimed along two lines of sight, the enhanced alignment cube yields complete alignment information through use of a single theodolite aimed along a single line of sight. Typically, an alignment cube is placed in contact with a datum surface or other reference feature on a scientific instrument during assembly or testing of the instrument. The alignment cube is then used in measuring a small angular deviation of the feature from a precise required orientation. Commonly, the deviation is expressed in terms of rotations (Rx,Ry,Rz) of the cube about the corresponding Cartesian axes (x,y,z). In traditional practice, in order to measure all three rotations, it is necessary to use two theodolites aimed at two orthogonal faces of the alignment cube, as shown in the upper part of the figure. To be able to perform such a measurement, one needs optical access to these two faces. In the case of an alignment cube inside a cryogenic chamber or other enclosed space, the optical-access requirement translates to a requirement for two windows located along the corresponding two orthogonal lines of sight into the chamber. In a typical application, it is difficult or impossible to provide two windows. The present enhanced version of the alignment cube makes it possible to measure all three rotations by use of a single line of sight, thereby obviating a second window.

  17. How the cosmic web induces intrinsic alignments of galaxies

    NASA Astrophysics Data System (ADS)

    Codis, S.; Dubois, Y.; Pichon, C.; Devriendt, J.; Slyz, A.

    2016-10-01

    Intrinsic alignments are believed to be a major source of systematics for future generation of weak gravitational lensing surveys like Euclid or LSST. Direct measurements of the alignment of the projected light distribution of galaxies in wide field imaging data seem to agree on a contamination at a level of a few per cent of the shear correlation functions, although the amplitude of the effect depends on the population of galaxies considered. Given this dependency, it is difficult to use dark matter-only simulations as the sole resource to predict and control intrinsic alignments. We report here estimates on the level of intrinsic alignment in the cosmological hydrodynamical simulation Horizon-AGN that could be a major source of systematic errors in weak gravitational lensing measurements. In particular, assuming that the spin of galaxies is a good proxy for their ellipticity, we show how those spins are spatially correlated and how they couple to the tidal field in which they are embedded. We will also present theoretical calculations that illustrate and qualitatively explain the observed signals.

  18. GSK3 Regulates Mitotic Chromosomal Alignment through CRMP4

    PubMed Central

    Ong Tone, Stephan; Dayanandan, Bama

    2010-01-01

    Background Glycogen Synthase Kinase 3 (GSK3) has been implicated in regulating chromosomal alignment and mitotic progression but the physiological substrates mediating these GSK3-dependent effects have not been identified. Collapsin Response Mediator Protein 4 (CRMP4) is a cytosolic phosphoprotein known to regulate cytoskeletal dynamics and is a known physiological substrate of GSK3. In this study, we investigate the role of CRMP4 during mitosis. Methodology and Principal Findings Here we demonstrate that during mitosis CRMP4 phosphorylation is regulated in a GSK3-dependent manner. We show that CRMP4 localizes to spindle microtubules during mitosis and loss of CRMP4 disrupts chromosomal alignment and mitotic progression. The effect of CRMP4 on chromosomal alignment is dependent on phosphorylation by GSK3 identifying CRMP4 as a critical GSK3 substrate during mitotic progression. We also provide mechanistic data demonstrating that CRMP4 regulates spindle microtubules consistent with its known role in the regulation of the microtubule cytoskeleton. Conclusion and Significance Our findings identify CRMP4 as a key physiological substrate of GSK3 in regulating chromosomal alignment and mitotic progression through its effect on spindle microtubules. PMID:21179545

  19. Enforcing Convexity for Improved Alignment with Constrained Local Models

    PubMed Central

    Wang, Yang; Lucey, Simon; Cohn, Jeffrey F.

    2010-01-01

    Constrained local models (CLMs) have recently demonstrated good performance in non-rigid object alignment/tracking in comparison to leading holistic approaches (e.g., AAMs). A major problem hindering the development of CLMs further, for non-rigid object alignment/tracking, is how to jointly optimize the global warp update across all local search responses. Previous methods have either used general purpose optimizers (e.g., simplex methods) or graph based optimization techniques. Unfortunately, problems exist with both these approaches when applied to CLMs. In this paper, we propose a new approach for optimizing the global warp update in an efficient manner by enforcing convexity at each local patch response surface. Furthermore, we show that the classic Lucas-Kanade approach to gradient descent image alignment can be viewed as a special case of our proposed framework. Finally, we demonstrate that our approach receives improved performance for the task of non-rigid face alignment/tracking on the MultiPIE database and the UNBC-McMaster archive. PMID:20622926

  20. Axonal alignment and enhanced neuronal differentiation of neural stem cells on graphene-nanoparticle hybrid structures.

    PubMed

    Solanki, Aniruddh; Chueng, Sy-Tsong Dean; Yin, Perry T; Kappera, Rajesh; Chhowalla, Manish; Lee, Ki-Bum

    2013-10-11

    Human neural stem cells (hNSCs) cultured on graphene-nanoparticle hybrid structures show a unique behavior wherein the axons from the differentiating hNSCs show enhanced growth and alignment. We show that the axonal alignment is primarily due to the presence of graphene and the underlying nanoparticle monolayer causes enhanced neuronal differentiation of the hNSCs, thus having great implications of these hybrid-nanostructures for neuro-regenerative medicine.

  1. Rotational Alignment Altered by Source Position Correlations

    NASA Technical Reports Server (NTRS)

    Jacobs, Chris S.; Heflin, M. B.; Lanyi, G. E.; Sovers, O. J.; Steppe, J. A.

    2010-01-01

    In the construction of modern Celestial Reference Frames (CRFs) the overall rotational alignment is only weakly constrained by the data. Therefore, common practice has been to apply a 3-dimensional No-Net-Rotation (NNR) constraint in order to align an under-construction frame to the ICRF. We present evidence that correlations amongst source position parameters must be accounted for in order to properly align a CRF at the 5-10 (mu)as level of uncertainty found in current work. Failure to do so creates errors at the 10-40 (mu)as level.

  2. Coelostat and heliostat - Theory of alignment

    NASA Astrophysics Data System (ADS)

    Demianski, M.; Pasachoff, J. M.

    1984-06-01

    For perfectly aligned heliostats and coelostats tracking at the solar rate and half the solar rate, respectively, the solar beam has no translational motion. But, particularly in the field at eclipses, it is not possible to align heliostats and coelostats with infinite precision. The authors derive the effect of small misalignments on the translational motion of the beam, and give tables to allow the calculation of the accuracy to which the instruments must be mounted and adjusted to attain a desired accuracy over a given duration. Further, it is shown how to derive the necessary adjustments to improve alignment, given measurements of the tracking error.

  3. Switchable Fresnel lens based on micropatterned alignment.

    PubMed

    Wang, Xiao-Qian; Srivastava, Abhishek K; Chigrinov, Vladimir G; Kwok, Hoi-Sing

    2013-06-01

    In this Letter we disclose a method to fabricate a liquid crystal (LC) Fresnel zone lens (FZL) with higher efficiency. The LCFZL, based on alternate twisted nematic (TN) and planar aligned (PA) regions, has been prepared by means of a two-step photo-alignment process. The FZL profile for both optical regimes, i.e., in TN and PA alignment domains, generates the same focal length (f). Thus, the proposed LCFZL manifests double light intensity at the focal point and therefore offers double the efficiency of existing FZLs. Moreover, because of lower driving voltage and fast response, these elements could find application in many modern devices.

  4. Self-aligning biaxial load frame

    DOEpatents

    Ward, Michael B.; Epstein, Jonathan S.; Lloyd, W. Randolph

    1994-01-01

    An self-aligning biaxial loading apparatus for use in testing the strength of specimens while maintaining a constant specimen centroid during the loading operation. The self-aligning biaxial loading apparatus consists of a load frame and two load assemblies for imparting two independent perpendicular forces upon a test specimen. The constant test specimen centroid is maintained by providing elements for linear motion of the load frame relative to a fixed crosshead, and by alignment and linear motion elements of one load assembly relative to the load frame.

  5. Self-aligning biaxial load frame

    DOEpatents

    Ward, M.B.; Epstein, J.S.; Lloyd, W.R.

    1994-01-18

    An self-aligning biaxial loading apparatus for use in testing the strength of specimens while maintaining a constant specimen centroid during the loading operation. The self-aligning biaxial loading apparatus consists of a load frame and two load assemblies for imparting two independent perpendicular forces upon a test specimen. The constant test specimen centroid is maintained by providing elements for linear motion of the load frame relative to a fixed cross head, and by alignment and linear motion elements of one load assembly relative to the load frame. 3 figures.

  6. Energy band alignment at the nanoscale

    NASA Astrophysics Data System (ADS)

    Deuermeier, Jonas; Fortunato, Elvira; Martins, Rodrigo; Klein, Andreas

    2017-01-01

    The energy band alignments at interfaces often determine the electrical functionality of a device. Along with the size reduction into the nanoscale, functional coatings become thinner than a nanometer. With the traditional analysis of the energy band alignment by in situ photoelectron spectroscopy, a critical film thickness is needed to determine the valence band offset. By making use of the Auger parameter, it becomes possible to determine the energy band alignment to coatings, which are only a few Ångström thin. This is demonstrated with experimental data of Cu2O on different kinds of substrate materials.

  7. Alignment of galaxies relative to their local environment in SDSS-DR8

    NASA Astrophysics Data System (ADS)

    Hirv, A.; Pelt, J.; Saar, E.; Tago, E.; Tamm, A.; Tempel, E.; Einasto, M.

    2017-02-01

    Aims: We study the alignment of galaxies relative to their local environment in SDSS-DR8 and, using these data, we discuss evolution scenarios for different types of galaxies. Methods: We defined a vector field of the direction of anisotropy of the local environment of galaxies. We summed the unit direction vectors of all close neighbours of a given galaxy in a particular way to estimate this field. We found the alignment angles between the spin axes of disc galaxies, or the minor axes of elliptical galaxies, and the direction of anisotropy. The distributions of cosines of these angles are compared to the random distributions to analyse the alignment of galaxies. Results: Sab galaxies show perpendicular alignment relative to the direction of anisotropy in a sparse environment, for single galaxies and galaxies of low luminosity. Most of the parallel alignment of Scd galaxies comes from dense regions, from 2...3 member groups and from galaxies with low luminosity. The perpendicular alignment of S0 galaxies does not depend strongly on environmental density nor luminosity; it is detected for single and 2...3 member group galaxies, and for main galaxies of 4...10 member groups. The perpendicular alignment of elliptical galaxies is clearly detected for single galaxies and for members of ≤10 member groups; the alignment increases with environmental density and luminosity. Conclusions: We confirm the existence of fossil tidally induced alignment of Sab galaxies at low z. The alignment of Scd galaxies can be explained via the infall of matter to filaments. S0 galaxies may have encountered relatively massive mergers along the direction of anisotropy. Major mergers along this direction can explain the alignment of elliptical galaxies. Less massive, but repeated mergers are possibly responsible for the formation of elliptical galaxies in sparser areas and for less luminous elliptical galaxies.

  8. Laser entertainment and light shows in education

    NASA Astrophysics Data System (ADS)

    Sabaratnam, Andrew T.; Symons, Charles

    2002-05-01

    Laser shows and beam effects have been a source of entertainment since its first public performance May 9, 1969, at Mills College in Oakland, California. Since 1997, the Photonics Center, NgeeAnn Polytechnic, Singapore, has been using laser shows as a teaching tool. Students are able to exhibit their creative skills and learn at the same time how lasers are used in the entertainment industry. Students will acquire a number of skills including handling three- phase power supply, operation of cooling system, and laser alignment. Students also acquire an appreciation of the arts, learning about shapes and contours as they develop graphics for the shows. After holography, laser show animation provides a combination of the arts and technology. This paper aims to briefly describe how a krypton-argon laser, galvanometer scanners, a polychromatic acousto-optic modulator and related electronics are put together to develop a laser projector. The paper also describes how students are trained to make their own laser animation and beam effects with music, and at the same time have an appreciation of the operation of a Class IV laser and the handling of optical components.

  9. Global multiple protein-protein interaction network alignment by combining pairwise network alignments

    PubMed Central

    2015-01-01

    Background A wealth of protein interaction data has become available in recent years, creating an urgent need for powerful analysis techniques. In this context, the problem of finding biologically meaningful correspondences between different protein-protein interaction networks (PPIN) is of particular interest. The PPIN of a species can be compared with that of other species through the process of PPIN alignment. Such an alignment can provide insight into basic problems like species evolution and network component function determination, as well as translational problems such as target identification and elucidation of mechanisms of disease spread. Furthermore, multiple PPINs can be aligned simultaneously, expanding the analytical implications of the result. While there are several pairwise network alignment algorithms, few methods are capable of multiple network alignment. Results We propose SMAL, a MNA algorithm based on the philosophy of scaffold-based alignment. SMAL is capable of converting results from any global pairwise alignment algorithms into a MNA in linear time. Using this method, we have built multiple network alignments based on combining pairwise alignments from a number of publicly available (pairwise) network aligners. We tested SMAL using PPINs of eight species derived from the IntAct repository and employed a number of measures to evaluate performance. Additionally, as part of our experimental investigations, we compared the effectiveness of SMAL while aligning up to eight input PPINs, and examined the effect of scaffold network choice on the alignments. Conclusions A key advantage of SMAL lies in its ability to create MNAs through the use of pairwise network aligners for which native MNA implementations do not exist. Experiments indicate that the performance of SMAL was comparable to that of the native MNA implementation of established methods such as IsoRankN and SMETANA. However, in terms of computational time, SMAL was significantly faster

  10. Computing posterior probabilities for score-based alignments using ppALIGN.

    PubMed

    Wolfsheimer, Stefan; Hartmann, Alexander; Rabus, Ralf; Nuel, Gregory

    2012-05-16

    Score-based pairwise alignments are widely used in bioinformatics in particular with molecular database search tools, such as the BLAST family. Due to sophisticated heuristics, such algorithms are usually fast but the underlying scoring model unfortunately lacks a statistical description of the reliability of the reported alignments. In particular, close to gaps, in low-score or low-complexity regions, a huge number of alternative alignments arise which results in a decrease of the certainty of the alignment. ppALIGN is a software package that uses hidden Markov Model techniques to compute position-wise reliability of score-based pairwise alignments of DNA or protein sequences. The design of the model allows for a direct connection between the scoring function and the parameters of the probabilistic model. For this reason it is suitable to analyze the outcomes of popular score based aligners and search tools without having to choose a complicated set of parameters. By contrast, our program only requires the classical score parameters (the scoring function and gap costs). The package comes along with a library written in C++, a standalone program for user defined alignments (ppALIGN) and another program (ppBLAST) which can process a complete result set of BLAST. The main algorithms essentially exhibit a linear time complexity (in the alignment lengths), and they are hence suitable for on-line computations. We have also included alternative decoding algorithms to provide alternative alignments. ppALIGN is a fast program/library that helps detect and quantify questionable regions in pairwise alignments. Due to its structure, the input/output interface it can to be connected to other post-processing tools. Empirically, we illustrate its usefulness in terms of correctly predicted reliable regions for sequences generated using the ROSE model for sequence evolution, and identify sensor-specific regions in the denitrifying betaproteobacterium Aromatoleum aromaticum.

  11. Effect of Femoral Resection on Coronal Overall Alignment after Conventional Total Knee Arthroplasty

    PubMed Central

    Zhao, Min-Wei; Wang, Lu; Zeng, Lin; Hu, Yu-Qing; Hu, Jin-Xin; Tian, Hua

    2016-01-01

    Background: A good postoperative alignment in total knee arthroplasty (TKA) is the key to achieving satisfactory results. We assessed the effect of femoral and tibial resection on the overall alignment after conventional TKA. Methods: We conducted a retrospective analysis of 212 primary TKAs in 188 patients. Intramedullary (IM)-guided resection was applied on the femoral side while extramedullary (EM)-guided resection was used on the tibial side. Using full-length X-ray, the preoperative femoral valgus angle and lower extremity alignment, as well as 2-week postoperative femoral and tibial prosthetic coronal alignment and overall lower extremity alignment, were measured. Results: Postoperatively, good prosthetic alignment was achieved in 191 cases (90.1%) on the tibial side and in 144 cases (67.9%) on the femoral side (χ2 = 5.441, P = 0.02). Multiple linear regression analysis was used to assess the effect of different alignment sides on the overall alignment in the coronal plane. Data were divided into five subgroups based on the valgus or varus status of the prostheses. The standardized regression coefficients of the femoral and tibial prosthetic alignment on the overall alignment were 0.666 and 0.414, respectively; in varus on both sides were 0.658 and 0.377, respectively; in valgus, 0.555 and 0.030; femoral side varus and tibial side valgus, 0.702 and 0.211; femoral side valgus and tibial side varus, −0.416 and 0.287. The study showed that the overall low extremity alignment was statistically influenced by the prosthetic alignment, except for the tibial prosthetic alignment when femoral prosthesis was in valgus (P = 0.153). Conclusions: In conventional TKA, tibial side EM-guided resection may offer satisfactory postoperative alignment, and femoral resection relying on IM guide may lead to more undesirable results. Postoperative coronal alignment is mainly affected by the femoral resection. Therefore, femoral side operation should receive adequate attention

  12. Dielectrophoretic manipulation of fluorescing single-walled carbon nanotubes.

    PubMed

    Mureau, Natacha; Mendoza, Ernest; Silva, S Ravi P

    2007-05-01

    We investigate the behavior of fluorescing single-walled carbon nanotubes (SWCNTs) under dielectrophoretic conditions and demonstrate their collection with fluorescence microscopy. SWCNTs are dispersed in water with the aid of a nonionic surfactant, Triton X-100, and labeled through noncovalent binding with the dye 3,3'-dihexyloxacarbocyanine iodide (diOC(6)). The chromophore's affinity to the SWCNTs is due to pi-stacking interactions. Carbon nanotube (CNT) localization is clearly identified on the fluorescence images, showing that the nanotubes concentrate between the electrodes and align along the electric field lines.

  13. Apse Alignment of the Uranian Rings

    NASA Astrophysics Data System (ADS)

    Mosqueira, Ignacio; Estrada, Paul R.

    2002-08-01

    An explanation of the dynamical mechanism for apse alignment of the eccentric uranian rings is necessary before observations can be used to determine properties such as ring masses, particle sizes, and elasticities. The leading model (P. Goldreich and S. Tremaine 1979, Astron J.84, 1638-1641) relies on the ring self-gravity to accomplish this task, yet it yields equilibrium masses which are not in accord with Voyager radio measurements. We explore possible solutions such that the self-gravity and the collisional terms are both involved in the process of apse alignment. We consider limits that correspond to a hot and a cold ring, and we show that pressure terms may play a significant role in the equilibrium conditions for the narrow uranian rings. In the cold ring case, where the scale height of the ring near periapse is comparable to the ring particle size, we introduce a new pressure correction pertaining to a region of the ring where the particles are locked in their relative positions and jammed against their neighbors and the velocity dispersion is so low that the collisions are nearly elastic. In this case, we find a solution such that the ring self-gravity maintains apse alignment against both differential precession ( m=1 mode) and the fluid pressure. We apply this model to the uranian α ring and show that, compared to the previous self-gravity model, the mass estimate for this ring increases by an order of magnitude. In the case of a hot ring, where the scale height can reach a value as much as 50 times the particle size, we find velocity dispersion profiles that result in pressure forces which act in such a way as to alter the ring equilibrium conditions, again leading to a ring mass increase of an order of magnitude. We find that such a velocity dispersion profile would require a different mechanism than is currently envisioned for establishing a heating/cooling balance in a finite-sized, inelastic particle ring. Finally, we introduce an important

  14. The effects of alignments: examining group faultlines, organizational cultures, and performance.

    PubMed

    Bezrukova, Katerina; Thatcher, Sherry M B; Jehn, Karen A; Spell, Chester S

    2012-01-01

    By integrating literature on group faultlines, organizational cultures, and value congruence, this research presents a framework that explains how cultural alignment across organizational levels may influence the relationship between faultlines and performance. The hypotheses were tested using representatively sampled multisource qualitative and quantitative data on 138 teams from a Fortune 500 company. The present findings demonstrate that although informational faultlines were detrimental for group performance, the negative relationship between faultlines and performance was reversed when cultures with a strong emphasis on results were aligned, was lessened when cultures with a weak emphasis on results were aligned, and remained negative when cultures were misaligned with respect to their results orientation. These findings show the importance of recognizing alignments not only within groups (group faultlines) but also outside groups (cultural alignments between the group and departments) when considering their implications for group performance.

  15. A Self-Alignment Algorithm for SINS Based on Gravitational Apparent Motion and Sensor Data Denoising

    PubMed Central

    Liu, Yiting; Xu, Xiaosu; Liu, Xixiang; Yao, Yiqing; Wu, Liang; Sun, Jin

    2015-01-01

    Initial alignment is always a key topic and difficult to achieve in an inertial navigation system (INS). In this paper a novel self-initial alignment algorithm is proposed using gravitational apparent motion vectors at three different moments and vector-operation. Simulation and analysis showed that this method easily suffers from the random noise contained in accelerometer measurements which are used to construct apparent motion directly. Aiming to resolve this problem, an online sensor data denoising method based on a Kalman filter is proposed and a novel reconstruction method for apparent motion is designed to avoid the collinearity among vectors participating in the alignment solution. Simulation, turntable tests and vehicle tests indicate that the proposed alignment algorithm can fulfill initial alignment of strapdown INS (SINS) under both static and swinging conditions. The accuracy can either reach or approach the theoretical values determined by sensor precision under static or swinging conditions. PMID:25923932

  16. Fuzzy adaptive strong tracking scaled unscented Kalman filter for initial alignment of large misalignment angles

    NASA Astrophysics Data System (ADS)

    Li, Jing; Song, Ningfang; Yang, Gongliu; Jiang, Rui

    2016-07-01

    In the initial alignment process of strapdown inertial navigation system (SINS), large misalignment angles always bring nonlinear problem, which can usually be processed using the scaled unscented Kalman filter (SUKF). In this paper, the problem of large misalignment angles in SINS alignment is further investigated, and the strong tracking scaled unscented Kalman filter (STSUKF) is proposed with fixed parameters to improve convergence speed, while these parameters are artificially constructed and uncertain in real application. To further improve the alignment stability and reduce the parameters selection, this paper proposes a fuzzy adaptive strategy combined with STSUKF (FUZZY-STSUKF). As a result, initial alignment scheme of large misalignment angles based on FUZZY-STSUKF is designed and verified by simulations and turntable experiment. The results show that the scheme improves the accuracy and convergence speed of SINS initial alignment compared with those based on SUKF and STSUKF.

  17. Fuzzy adaptive strong tracking scaled unscented Kalman filter for initial alignment of large misalignment angles.

    PubMed

    Li, Jing; Song, Ningfang; Yang, Gongliu; Jiang, Rui

    2016-07-01

    In the initial alignment process of strapdown inertial navigation system (SINS), large misalignment angles always bring nonlinear problem, which can usually be processed using the scaled unscented Kalman filter (SUKF). In this paper, the problem of large misalignment angles in SINS alignment is further investigated, and the strong tracking scaled unscented Kalman filter (STSUKF) is proposed with fixed parameters to improve convergence speed, while these parameters are artificially constructed and uncertain in real application. To further improve the alignment stability and reduce the parameters selection, this paper proposes a fuzzy adaptive strategy combined with STSUKF (FUZZY-STSUKF). As a result, initial alignment scheme of large misalignment angles based on FUZZY-STSUKF is designed and verified by simulations and turntable experiment. The results show that the scheme improves the accuracy and convergence speed of SINS initial alignment compared with those based on SUKF and STSUKF.

  18. Photogeneration and enhanced charge transport in aligned smectic liquid crystalline organic semiconductor

    SciTech Connect

    Paul, Sanjoy; Ellman, Brett; Tripathi, Suvagata; Twieg, Robert J.

    2015-10-07

    Liquid crystalline organic semiconductors are emerging candidates for applications in electronic and photonic devices. One of the most attractive aspects of such materials is the potential, in principle, to easily control and manipulate the molecular alignment of the semiconductor over large length scales. Here, we explore the consequences of alignment in a model smectic liquid crystalline semiconductor, and find that the photogeneration efficiency is a strong function of incident polarization in aligned samples. A straightforward theory shows that such behavior is a general feature of aligned materials, regardless of the details of photophysics. Furthermore, we uncover tentative evidence that the mobility of aligned samples is substantially enhanced. Both of these phenomena are of significant technological importance.

  19. Anchoring Strength of Thin Aligned-Polymer Films Formed by Liquid Crystalline Monomer

    NASA Astrophysics Data System (ADS)

    Murashige, Takeshi; Fujikake, Hideo; Ikehata, Seiichiro; Sato, Fumio

    2003-04-01

    We have evaluated the polar anchoring strength of a thin molecule-aligned polymer film formed by a liquid crystalline monomer. The polymer film was obtained by photopolymerization of the monomer oriented by a rubbed polyimide alignment layer in a chamber filled with N2 gas. We fabricated a nematic liquid crystal cell using the thin aligned-polymer films as alignment layers, and then evaluated the anchoring strength of the polymer by measuring the optical retardation curve of the cell driven by voltages. The experimental result showed that the anchoring strength was one order of magnitude lower than that of a conventional rubbed polyimide alignment layer, and decreased with increasing the cure temperature of the monomer film.

  20. Alignment of the CMS silicon strip tracker during stand-alone commissioning

    SciTech Connect

    Adam, W.; et al.

    2009-07-01

    The results of the CMS tracker alignment analysis are presented using the data from cosmic tracks, optical survey information, and the laser alignment system at the Tracker Integration Facility at CERN. During several months of operation in the spring and summer of 2007, about five million cosmic track events were collected with a partially active CMS Tracker. This allowed us to perform first alignment of the active silicon modules with the cosmic tracks using three different statistical approaches; validate the survey and laser alignment system performance; and test the stability of Tracker structures under various stresses and temperatures ranging from +15C to -15C. Comparison with simulation shows that the achieved alignment precision in the barrel part of the tracker leads to residual distributions similar to those obtained with a random misalignment of 50 (80) microns in the outer (inner) part of the barrel.

  1. Automatic alignment method for calibration of hydrometers

    NASA Astrophysics Data System (ADS)

    Lee, Y. J.; Chang, K. H.; Chon, J. C.; Oh, C. Y.

    2004-04-01

    This paper presents a new method to automatically align specific scale-marks for the calibration of hydrometers. A hydrometer calibration system adopting the new method consists of a vision system, a stepping motor, and software to control the system. The vision system is composed of a CCD camera and a frame grabber, and is used to acquire images. The stepping motor moves the camera, which is attached to the vessel containing a reference liquid, along the hydrometer. The operating program has two main functions: to process images from the camera to find the position of the horizontal plane and to control the stepping motor for the alignment of the horizontal plane with a particular scale-mark. Any system adopting this automatic alignment method is a convenient and precise means of calibrating a hydrometer. The performance of the proposed method is illustrated by comparing the calibration results using the automatic alignment method with those obtained using the manual method.

  2. Coval: Improving Alignment Quality and Variant Calling Accuracy for Next-Generation Sequencing Data

    PubMed Central

    Kosugi, Shunichi; Natsume, Satoshi; Yoshida, Kentaro; MacLean, Daniel; Cano, Liliana; Kamoun, Sophien; Terauchi, Ryohei

    2013-01-01

    Accurate identification of DNA polymorphisms using next-generation sequencing technology is challenging because of a high rate of sequencing error and incorrect mapping of reads to reference genomes. Currently available short read aligners and DNA variant callers suffer from these problems. We developed the Coval software to improve the quality of short read alignments. Coval is designed to minimize the incidence of spurious alignment of short reads, by filtering mismatched reads that remained in alignments after local realignment and error correction of mismatched reads. The error correction is executed based on the base quality and allele frequency at the non-reference positions for an individual or pooled sample. We demonstrated the utility of Coval by applying it to simulated genomes and experimentally obtained short-read data of rice, nematode, and mouse. Moreover, we found an unexpectedly large number of incorrectly mapped reads in ‘targeted’ alignments, where the whole genome sequencing reads had been aligned to a local genomic segment, and showed that Coval effectively eliminated such spurious alignments. We conclude that Coval significantly improves the quality of short-read sequence alignments, thereby increasing the calling accuracy of currently available tools for SNP and indel identification. Coval is available at http://sourceforge.net/projects/coval105/. PMID:24116042

  3. Alignment of a three-mirror anastigmatic telescope using nodal aberration theory.

    PubMed

    Gu, Zhiyuan; Yan, Changxiang; Wang, Yang

    2015-09-21

    Most computer-aided alignment methods for optical systems are based on numerical algorithms at present, which omit aberration theory. This paper presents a novel alignment algorithm for three-mirror anastigmatic (TMA) telescopes using Nodal Aberration Theory (NAT). The aberration field decenter vectors and boresight error of misaligned TMA telescopes are derived. Two alignment models based on 3rd and 5th order NAT are established successively and compared in the same alignment example. It is found that the average and the maximum RMS wavefront errors in the whole field of view of 0.3° × 0.15° are 0.063 λ (λ = 1 μm) and 0.068 λ respectively after the 4th alignment action with the 3rd order model, and 0.011 λ and 0.025 λ (nominal values) respectively after the 3rd alignment action with the 5th order model. Monte-Carlo alignment simulations are carried out with the 5th order model. It shows that the 5th order model still has good performance even when the misalignment variables are large (-1 mm≤linear misalignment≤1 mm, -0.1°≤angular misalignment≤0.1°), and multiple iterative alignments are needed when the misalignment variables increase.

  4. Influence of alignment errors on contact pressure during straight bevel gear meshing process

    NASA Astrophysics Data System (ADS)

    Han, Xinghui; Hua, Lin; Deng, Song; Luo, Qiuping

    2015-11-01

    Straight bevel gears are widely applied in automotive, aerospace, chemical and many other fields as one of the most common type of gears. Currently, the researches on straight bevel gears have focused on the fields of fatigue, wear, noise and vibration, while little attention is paid to the effect of multiple alignment errors on the gear tooth wear. To study the influence of alignment errors on the gear tooth wear, a simulated model of a straight bevel gear pair is established. Then, the contact pressure on the tooth surface is analyzed under the various alignment errors according to the Archard wear relationship. The main combinations of alignment errors played vital roles on the tooth wear are investigated. The result shows that under the single alignment error, the contact pressure moves to the tooth heel and increases greatly at here when Δ P=0.1 or Δ G=0.1; when Δ E=-0.03, the contact pressure greatly increases at the tooth heel, but it obviously increases at the tooth toe when Δ E=0.03; the alignment error Δ γ=1 has little effect on the contact pressure on the tooth surface. Moreover, the combination of Δ P, Δ G, Δ E<0 and Δ γ is the most dangerous type among the multiple alignment errors. This research provides valuable guidelines for predicting the tooth wear under various alignment errors.

  5. Double in-plane alignment in biaxially textured thin films

    NASA Astrophysics Data System (ADS)

    Elofsson, V.; Saraiva, M.; Boyd, R. D.; Sarakinos, K.

    2014-12-01

    The scientific interest and technological relevance of biaxially textured polycrystalline thin films stem from their microstructure that resembles that of single crystals. To explain the origin and predict the type of biaxial texture in off-normally deposited films, Mahieu et al. have developed an analytical model [S. Mahieu et al., Thin Solid Films 515, 1229 (2006)]. For certain materials, this model predicts the occurrence of a double in-plane alignment, however, experimentally only a single in-plane alignment has been observed and the reason for this discrepancy is still unknown. The model calculates the resulting in-plane alignment by considering the growth of faceted grains with an out-of-plane orientation that corresponds to the predominant film out-of-plane texture. This approach overlooks the fact that in vapor condensation experiments where growth kinetics is limited and only surface diffusion is active, out-of-plane orientation selection is random during grain nucleation and happens only upon grain impingement. Here, we compile and implement an experiment that is consistent with the key assumptions set forth by the in-plane orientation selection model by Mahieu et al.; a Cr film is grown off-normally on a fiber textured Ti epilayer to pre-determine the out-of-plane orientation and only allow for competitive growth with respect to the in-plane alignment. Our results show unambiguously a biaxially textured Cr (110) film that possesses a double in-plane alignment, in agreement with predictions of the in-plane selection model. Thus, a long standing discrepancy in the literature is resolved, paving the way towards more accurate theoretical descriptions and hence knowledge-based control of microstructure evolution in biaxially textured thin films.

  6. Heuristic reusable dynamic programming: efficient updates of local sequence alignment.

    PubMed

    Hong, Changjin; Tewfik, Ahmed H

    2009-01-01

    Recomputation of the previously evaluated similarity results between biological sequences becomes inevitable when researchers realize errors in their sequenced data or when the researchers have to compare nearly similar sequences, e.g., in a family of proteins. We present an efficient scheme for updating local sequence alignments with an affine gap model. In principle, using the previous matching result between two amino acid sequences, we perform a forward-backward alignment to generate heuristic searching bands which are bounded by a set of suboptimal paths. Given a correctly updated sequence, we initially predict a new score of the alignment path for each contour to select the best candidates among them. Then, we run the Smith-Waterman algorithm in this confined space. Furthermore, our heuristic alignment for an updated sequence shows that it can be further accelerated by using reusable dynamic programming (rDP), our prior work. In this study, we successfully validate "relative node tolerance bound" (RNTB) in the pruned searching space. Furthermore, we improve the computational performance by quantifying the successful RNTB tolerance probability and switch to rDP on perturbation-resilient columns only. In our searching space derived by a threshold value of 90 percent of the optimal alignment score, we find that 98.3 percent of contours contain correctly updated paths. We also find that our method consumes only 25.36 percent of the runtime cost of sparse dynamic programming (sDP) method, and to only 2.55 percent of that of a normal dynamic programming with the Smith-Waterman algorithm.

  7. Tidal Alignment of Exoplanets Around Low Mass Stars

    NASA Astrophysics Data System (ADS)

    Penev, Kaloyan; Jackson, Brian K.

    2014-06-01

    Using the Rossiter-McLaughlin effect, the projected spin-orbit angle for many exoplanetary systems has now been measured. Thanks to this rapidly increasing sample it is becoming clear that stars with surface convective zones appear to be well aligned while those without span a wide range of inclinations. The explanation proposed (Winn et al 2010) is that perhaps only the convective zones align with the planet, while the cores remain misaligned. This explanation suffers from two problems however: the core-envelope coupling in low mass stars appears to be strong enough to prevent long-lived differential rotation and even if only the convective zone is aligned, the planet generally does not survive for long after that. Since tides due to a planet on a misaligned orbit have a component at the rotational frequency of the star, and for an aligned planet the only frequency is the difference between the generally fast planet and the slowly rotating star, it is conceivable that misaligned systems are subject to much enhanced dissipation, acting for example on resonantly excited inertial waves in the star. However, Rogers & Lin (2013) point out that under inertial mode dissipation, in addition to aligned orbits one would expect a pile-up on polar and/or exactly counter-rotating orbits. We propose that the extra equilibrium solutions disappear if one includes in the evolution the fact that stars evolve and shed angular momentum throughout their lifetime. We have built a model including all those effects and will show results exploring this explanation.

  8. Fiber optics welder having movable aligning mirror

    DOEpatents

    Higgins, Robert W.; Robichaud, Roger E.

    1981-01-01

    A system for welding fiber optic waveguides together. The ends of the two fibers to be joined together are accurately, collinearly aligned in a vertical orientation and subjected to a controlled, diffuse arc to effect welding and thermal conditioning. A front-surfaced mirror mounted at a 45.degree. angle to the optical axis of a stereomicroscope mounted for viewing the junction of the ends provides two orthogonal views of the interface during the alignment operation.

  9. Regionally Aligned Forces: Concept Viability and Implementation

    DTIC Science & Technology

    2015-03-01

    Carlisle Compendia of Collaborative Research United States Army War College Student Publications Regionally Aligned Forces: Concept Viability and...Concept Viability and Implementation 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER...Carlisle Compendia of Collaborative Research United States Army War College Student Publications Regionally Aligned Forces: Concept Viability and

  10. Technology Alignment and Portfolio Prioritization (TAPP)

    NASA Technical Reports Server (NTRS)

    Funaro, Gregory V.; Alexander, Reginald A.

    2015-01-01

    Technology Alignment and Portfolio Prioritization (TAPP) is a method being developed by the Advanced Concepts Office, at NASA Marshall Space Flight Center. The TAPP method expands on current technology assessment methods by incorporating the technological structure underlying technology development, e.g., organizational structures and resources, institutional policy and strategy, and the factors that motivate technological change. This paper discusses the methods ACO is currently developing to better perform technology assessments while taking into consideration Strategic Alignment, Technology Forecasting, and Long Term Planning.

  11. Control rod housing alignment and repair method

    SciTech Connect

    Dixon, R.C.; Deaver, G.A.; Punches, J.R.; Singleton, G.E.; Erbes, J.G.; Offer, H.P.

    1992-04-07

    This patent describes a method for underwater welding of a control rod drive housing inserted through a stub tube to maintain requisite alignment and elevation of the top of the control rod drive housing to an overlying and corresponding aperture in a core plate as measured by an alignment device which determines the relative elevation and angularity with respect to the aperture. It comprises providing a welding cylinder dependent from the alignment device such that the elevation of the top of the welding cylinder is in a fixed relationship to the alignment device and is gas-proof; pressurizing the welding cylinder with inert welding gas sufficient to maintain the interior of the welding cylinder dry; lowering the welding cylinder through the aperture in the core plate by depending the cylinder with respect to the alignment device, the lowering including lowering through and adjusting the elevation relationship of the welding cylinder to the alignment device such that when the alignment device is in position to measure the elevation and angularity of the new control rod drive housing, the lower distal end of the welding cylinder extends below the upper periphery of the stub where welding is to occur; inserting a new control rod drive housing through the stub tube and positioning the control rod drive housing to a predetermined relationship to the anticipated final position of the control rod drive housing; providing welding implements transversely rotatably mounted interior of the welding cylinder relative to the alignment device such that the welding implements may be accurately positioned for dispensing weldment around the periphery of the top of the stub tube and at the side of the control rod drive housing; measuring the elevation and angularity of the control rod drive housing; and dispensing weldment along the top of the stub tube and at the side of the control rod drive housing.

  12. A Tracker Alignment Framework for Augmented Reality

    DTIC Science & Technology

    2003-01-01

    A Tracker Alignment Framework for Augmented Reality Yohan Baillot and Simon J. Julier ITT Advanced Engineering & Sciences 2560 Huntington Ave...with as few as three measurements. 1. Introduction Almost all Augmented Reality (AR) systems use a track- ing system to capture motion of objects in...DATES COVERED 00-00-2003 to 00-00-2003 4. TITLE AND SUBTITLE A Tracker Alignment Framework for Augmented Reality 5a. CONTRACT NUMBER 5b. GRANT

  13. Differential Heating of Magnetically Aligned Dust Grains

    NASA Astrophysics Data System (ADS)

    Vaillancourt, John E.; Andersson, B.

    2013-01-01

    We use far-infrared photometric maps from IRAS and Herschel to search for the differential heating of asymmetric dust grains aligned with respect to an interstellar magnetic field and heated by a localized radiation source. The grains are known to be asymmetric and have a net alignment of their axes from observations of background starlight polarization. Modern theories on grain alignment suggest that photons from stars embedded in the foreground cloud are a key ingredient of the physical mechanism responsible for alignment (i.e., radiative torques). This theory predicts a relation between the grain alignment efficiency and the angle between the magnetic field and the direction to the aligning radiation source. This effect has been tentatively observed in a source with a very simple geometry (Andersson et al. 2011): the aligning photons are primarily from a single localized source (i.e., a single star) and the local magnetic field direction is known to be fairly uniform. Such a region also has consequences for the distribution of grain heating. For example, asymmetric grains whose largest cross-sections are normal to the incident stellar radiation will reach warmer equilibrium temperatures compared to grains whose largest cross-section is parallel to that direction. This should be observed as an azimuthal dependence of the dust color temperature. We present evidence of such a dependence using IRAS data at 60 and 100 micron. We expect this effect to be stronger using longer wavelength (i.e., 160 micron) data better coupled to the "big-grain" dust population, grains which are also more efficiently aligned with the local magnetic field. Here we also present the results of our on-going work to search for this signal using Herschel maps towards three candidate stars.

  14. Unconventional High Density Vertically Aligned Conducting Polymer

    DTIC Science & Technology

    2014-08-21

    electrodes with unique and controlled nano-morphologies: highly aligned carbon nanotubes (A-CNT) and graphene. This program also developed the...highly aligned carbon nanotubes forests (A-CNTs) and graphene. As synthesized A- CNTs have low volume fraction of CNT (~ 1 %). Traditional method to... nanotubes (A-CNTs). In contract to the electric double layer capacitors (EDLC) which store charges on the surface of the electrodes, conducting

  15. Alignment of photoions far from threshold

    NASA Astrophysics Data System (ADS)

    Das, Romith; Wu, Chuanyong; Mihill, A. G.; Poliakoff, E. D.; Wang, Kwanghsi; McKoy, V.

    1994-09-01

    We present results of measurements and calculations of the alignment for CO+(B 2Σ+) photoions over an extended energy range (0≤Ek≤210 eV). The polarization of CO+(B 2Σ+→X 2Σ+) fluorescence indicates that the photoions retain significant alignment even at high energies. Agreement between the measured and calculated polarization of the fluorescence is excellent.

  16. Image-based temporal alignment of echocardiographic sequences

    NASA Astrophysics Data System (ADS)

    Danudibroto, Adriyana; Bersvendsen, Jørn; Mirea, Oana; Gerard, Olivier; D'hooge, Jan; Samset, Eigil

    2016-04-01

    Temporal alignment of echocardiographic sequences enables fair comparisons of multiple cardiac sequences by showing corresponding frames at given time points in the cardiac cycle. It is also essential for spatial registration of echo volumes where several acquisitions are combined for enhancement of image quality or forming larger field of view. In this study, three different image-based temporal alignment methods were investigated. First, a method based on dynamic time warping (DTW). Second, a spline-based method that optimized the similarity between temporal characteristic curves of the cardiac cycle using 1D cubic B-spline interpolation. Third, a method based on the spline-based method with piecewise modification. These methods were tested on in-vivo data sets of 19 echo sequences. For each sequence, the mitral valve opening (MVO) time was manually annotated. The results showed that the average MVO timing error for all methods are well under the time resolution of the sequences.

  17. Orthodontics Align Crooked Teeth and Boost Self-Esteem

    MedlinePlus

    ... desktop! more... Orthodontics Align Crooked Teeth and Boost Self- esteem Article Chapters Orthodontics Align Crooked Teeth and Boost Self- esteem Orthodontics print full article print this chapter email ...

  18. Uniaxially aligned nanofibrous cylinders by electrospinning.

    PubMed

    Jana, Soumen; Cooper, Ashleigh; Ohuchi, Fumio; Zhang, Miqin

    2012-09-26

    Aligned nanofibers have drawn increasing interest for applications in biomedical engineering, electronics, and energy storage systems owing to the unique physicochemical properties provided by their anisotropy and high surface-to-volume ratio. Nevertheless, direct fabrication or assembly of aligned nanofibers into a 3-dimensional standalone construct with practically applicable dimensions presents an enormous challenge. We report a facile method to fabricate aligned nanofibrous cylinders, a widely used geometric form, by electrospinning aligned nanofibers across the gap between a pair of pin electrodes placed apart uniaxially. With this approach, cylindrical nanofibrous constructs of several millimeters in diameter and several centimeters in length can be readily produced. The versatility of the approach was demonstrated with several commonly used polymeric and ceramic materials, including polycaprolactone (PCL), chitosan/PCL, polyvinylidene fluoride, and titania. For a model application in tissue engineering, skeletal muscle cells were cultured on nanofibrous cylinders, which effectively produced highly aligned and densely populated myotubes along the nanofiber orientation, favorable for muscle tissue regeneration. With high structural integrity and stability, these can be directly integrated into devices or implanted in vivo as a standalone construct without the support of a substrate, thus increasing the portability, efficiency, and applicability of aligned nanofibers.

  19. DALIX: optimal DALI protein structure alignment.

    PubMed

    Wohlers, Inken; Andonov, Rumen; Klau, Gunnar W

    2013-01-01

    We present a mathematical model and exact algorithm for optimally aligning protein structures using the DALI scoring model. This scoring model is based on comparing the interresidue distance matrices of proteins and is used in the popular DALI software tool, a heuristic method for protein structure alignment. Our model and algorithm extend an integer linear programming approach that has been previously applied for the related, but simpler, contact map overlap problem. To this end, we introduce a novel type of constraint that handles negative score values and relax it in a Lagrangian fashion. The new algorithm, which we call DALIX, is applicable to any distance matrix-based scoring scheme. We also review options that allow to consider fewer pairs of interresidue distances explicitly because their large number hinders the optimization process. Using four known data sets of varying structural similarity, we compute many provably score-optimal DALI alignments. This allowed, for the first time, to evaluate the DALI heuristic in sound mathematical terms. The results indicate that DALI usually computes optimal or close to optimal alignments. However, we detect a subset of small proteins for which DALI fails to generate any significant alignment, although such alignments do exist.

  20. Orthodontic Tooth Movement with Clear Aligners

    PubMed Central

    Drake, Carl T.; McGorray, Susan P.; Dolce, Calogero; Nair, Madhu; Wheeler, Timothy T.

    2012-01-01

    Clear aligners provide a convenient model to measure orthodontic tooth movement (OTM). We examined the role of in vivo aligner material fatigue and subject-specific factors in tooth movement. Fifteen subjects seeking orthodontic treatment at the University of Florida were enrolled. Results were compared with data previously collected from 37 subjects enrolled in a similar protocol. Subjects were followed prospectively for eight weeks. An upper central incisor was programmed to move 0.5 mm. every two weeks using clear aligners. A duplicate aligner was provided for the second week of each cycle. Weekly polyvinyl siloxane (PVS) impressions were taken, and digital models were fabricated to measure OTM. Initial and final cone beam computed tomography (CBCT) images were obtained to characterize OTM. Results were compared to data from a similar protocol, where subjects received a new aligner biweekly. No significant difference was found in the amount of OTM between the two groups, with mean total OTM of 1.11 mm. (standard deviation (SD) 0.30) and 1.07 mm. (SD 0.33) for the weekly aligner and biweekly control groups, respectively (P = 0.72). Over eight weeks, in two-week intervals, material fatigue does not play a significant role in the rate or amount of tooth movement. PMID:22928114

  1. Parametric and non-parametric masking of randomness in sequence alignments can be improved and leads to better resolved trees

    PubMed Central

    2010-01-01

    Background Methods of alignment masking, which refers to the technique of excluding alignment blocks prior to tree reconstructions, have been successful in improving the signal-to-noise ratio in sequence alignments. However, the lack of formally well defined methods to identify randomness in sequence alignments has prevented a routine application of alignment masking. In this study, we compared the effects on tree reconstructions of the most commonly used profiling method (GBLOCKS) which uses a predefined set of rules in combination with alignment masking, with a new profiling approach (ALISCORE) based on Monte Carlo resampling within a sliding window, using different data sets and alignment methods. While the GBLOCKS approach excludes variable sections above a certain threshold which choice is left arbitrary, the ALISCORE algorithm is free of a priori rating of parameter space and therefore more objective. Results ALISCORE was successfully extended to amino acids using a proportional model and empirical substitution matrices to score randomness in multiple sequence alignments. A complex bootstrap resampling leads to an even distribution of scores of randomly similar sequences to assess randomness of the observed sequence similarity. Testing performance on real data, both masking methods, GBLOCKS and ALISCORE, helped to improve tree resolution. The sliding window approach was less sensitive to different alignments of identical data sets and performed equally well on all data sets. Concurrently, ALISCORE is capable of dealing with different substitution patterns and heterogeneous base composition. ALISCORE and the most relaxed GBLOCKS gap parameter setting performed best on all data sets. Correspondingly, Neighbor-Net analyses showed the most decrease in conflict. Conclusions Alignment masking improves signal-to-noise ratio in multiple sequence alignments prior to phylogenetic reconstruction. Given the robust performance of alignment profiling, alignment masking

  2. Fabrication, Testing, Coating and Alignment of Fast Segmented Optics

    DTIC Science & Technology

    2006-05-25

    mirror segment, a 100 mm thick Zerodur mirror blank was purchased from Schott. Figure 2 shows the segment and its support for polishing and testing in...Polishing large off-axis segments of fast primary mirrors 2. Testing large segments in an off-axis geometry 3. Alignment of multiple segments of a large... mirror 4. Coatings that reflect high-intensity light without distorting the substrate These technologies are critical because of several unique

  3. Polymer Composite Using Aligned Carbon Nanotubes for Efficient Heat Transfer

    DTIC Science & Technology

    2012-01-17

    graphite, phonons dominate the specific heat above 20 K [2], whereas in SWNTs and MWNTs the phonon contribution governs at all temperatures [3]. Yi...Smalley’s group performed thermal conductivity measurements on bulk samples of SWNTs [6]. The results show a different temperature dependence of k, thus...conductivity of nanotubes and found that mats of randomly oriented SWNTs exhibited values of ca. 35 W m-1 K-1, whereas aligned SWNTs exhibit thermal

  4. Alignment of angular velocity sensors for a vestibular prosthesis.

    PubMed

    Digiovanna, Jack; Carpaneto, Jacopo; Micera, Silvestro; Merfeld, Daniel M

    2012-02-13

    Vestibular prosthetics transmit angular velocities to the nervous system via electrical stimulation. Head-fixed gyroscopes measure angular motion, but the gyroscope coordinate system will not be coincident with the sensory organs the prosthetic replaces. Here we show a simple calibration method to align gyroscope measurements with the anatomical coordinate system. We benchmarked the method with simulated movements and obtain proof-of-concept with one healthy subject. The method was robust to misalignment, required little data, and minimal processing.

  5. A simple method for fabrication of electrospun fibers with controlled degree of alignment having potential for nerve regeneration applications.

    PubMed

    Vimal, Sunil Kumar; Ahamad, Nadim; Katti, Dhirendra S

    2016-06-01

    In peripheral nerve injuries where direct suturing of nerve endings is not feasible, nerve regeneration has been facilitated through the use of artificially aligned fibrous scaffolds that provide directional growth of neurons to bridge the gap. The degree of fiber alignment is crucial and can impact the directionality of cells in a fibrous scaffold. While there have been multiple approaches that have been used for controlling fiber alignment, however, they have been associated with a compromised control on other properties, such as diameter, morphology, curvature, and topology of fibers. Therefore, the present study demonstrates a modified electrospinning set-up, that enabled fabrication of electrospun fibers with controlled degree of alignment from non-aligned (NA), moderately aligned (MA, 75%) to highly aligned (HA, 95%) sub-micron fibers while keeping other physical properties unchanged. The results demonstrate that the aligned fibers (MA and HA) facilitated directional growth of human astrocytoma cells (U373), wherein the aspect ratio of cells was found to increase with an increase in degree of fibers alignment. In contrast to NA and MA fibers, the HA fibers showed improved contact guidance to U373 cells that was demonstrated by a significantly higher cell aspect ratio and nuclear aspect ratio. In conclusion, the present study demonstrated a modified electrospinning setup to fabricate differentially aligned fibrous scaffolds with the HA fibers showing potential for use in neural tissue engineering.

  6. Raman identification of edge alignment of bilayer graphene down to the nanometer scale.

    PubMed

    Zhang, Xin; Li, Qiao-Qiao; Han, Wen-Peng; Lu, Yan; Shi, Wei; Wu, Jiang-Bin; Mikhaylushkin, Arkady S; Tan, Ping-Heng

    2014-07-07

    The ideal edges of bilayer graphene (BLG) are that the edges of the top and bottom graphene layers (GLs) of BLG are well-aligned. Actually, the alignment distance between the edges of the top and bottom GLs of a real BLG can be as large as the submicrometer scale or as small as zero, which cannot be distinguished using an optical microscope. Here, we present a detailed Raman study on BLG at its edges. If the alignment distance of the top and bottom GLs of BLG is larger than the laser spot, the measured D mode at the edge of the top GL of BLG shows a similar spectral profile to that of disordered BLG. If the alignment distance is smaller than the laser spot, the D mode at a real BLG edge shows three typical spectral profiles similar to that at the edge of SLG, that of the well-aligned edge of BLG, or a combination of both. We show the sensitivity and ability of Raman spectroscopy to acquire the alignment distance between two edges of top and bottom GLs of BLG as small as several nanometers, which is far beyond the diffraction limit of a laser spot. This work opens the possibility to probe the edge alignment of multi-layer graphene.

  7. Haplotype assembly from aligned weighted SNP fragments.

    PubMed

    Zhao, Yu-Ying; Wu, Ling-Yun; Zhang, Ji-Hong; Wang, Rui-Sheng; Zhang, Xiang-Sun

    2005-08-01

    Given an assembled genome of a diploid organism the haplotype assembly problem can be formulated as retrieval of a pair of haplotypes from a set of aligned weighted SNP fragments. Known computational formulations (models) of this problem are minimum letter flips (MLF) and the weighted minimum letter flips (WMLF; Greenberg et al. (INFORMS J. Comput. 2004, 14, 211-213)). In this paper we show that the general WMLF model is NP-hard even for the gapless case. However the algorithmic solutions for selected variants of WMFL can exist and we propose a heuristic algorithm based on a dynamic clustering technique. We also introduce a new formulation of the haplotype assembly problem that we call COMPLETE WMLF (CWMLF). This model and algorithms for its implementation take into account a simultaneous presence of multiple kinds of data errors. Extensive computational experiments indicate that the algorithmic implementations of the CWMLF model achieve higher accuracy of haplotype reconstruction than the WMLF-based algorithms, which in turn appear to be more accurate than those based on MLF.

  8. Measurement of dichroism in aligned molecules

    NASA Astrophysics Data System (ADS)

    Lavorel, B.; Babilotte, Ph.; Karras, G.; Billard, F.; Hertz, E.; Faucher, O.

    2016-10-01

    We present dichroism measurements in molecules prealigned with a short and intense laser pulse, using a balanced detection and a pump-probe scheme. The birefringence signal is recorded under the same irradiation conditions along with the dichroism one. Our results show that the dichroism signal is of comparable order of magnitude as the one originating from birefringence and reflects the degree of alignment. The balanced detection scheme directly provides an heterodyne signal for both birefringence and dichroism. Experiments are first conducted in air and then in pure nitrogen and carbon dioxide gases. A general approach allows us to explain the temporal shape of the dichroic response and to extract the imaginary part of the polarizability anisotropy. Furthermore, a simple model invoking the finite response time of the molecule to the probe excitation provides a complementary perspective. Using this model, the phase shift between the oscillations of the probe electric field and the induced polarization can be estimated. We find that the phase shift corresponds to a time delay of about 130 as (10-18s) in both molecules. Calculation of the energy flow between the probe field and the molecules taking into account the phase shift is compared to the experimental data.

  9. Determining knee joint alignment using digital photographs.

    PubMed

    Schmitt, Holger; Kappel, Hannes; Moser, Michael T; Cardenas-Montemayor, Eloy; Engelleiter, Karoly; Kuni, Benita; Clarius, Michael

    2008-08-01

    The objective of this work is to find out how reliably knee joint alignment can be measured from a standardized photograph and what influence changes in the standing position have on the angles measured. The interrater, intrarater, and test-retest reliability were evaluated. The influence of image-object distance, the distance between the legs and leg rotation on the measured angles was evaluated. In addition to the digital photographs, 10 full-length radiographs were obtained in an upright position to determine whether the measured angles represent the anatomic axis or mechanical axis. There was high correlation between the interrater (ICC 0.997), intrarater (ICC 0.989) and test-retest reliability (ICC 0.904). Only slight deviation was found with the changes in radiograph-object distance (0 degrees -1.8 degrees ). With feet together varus malalignment was greater. Leg rotation showed a strong influence on the measured results (ICC 0.658). The angle measured in the digital photographs reflects the mechanical axis with only slight deviation (0.12 degrees -1.9 degrees ). The measurement of the clinical axis using standardized radiography is highly reliable and can be used for individual follow-up of varus and valgus malalignments.

  10. Dynamic Alignment Models for Neural Coding

    PubMed Central

    Kollmorgen, Sepp; Hahnloser, Richard H. R.

    2014-01-01

    Recently, there have been remarkable advances in modeling the relationships between the sensory environment, neuronal responses, and behavior. However, most models cannot encompass variable stimulus-response relationships such as varying response latencies and state or context dependence of the neural code. Here, we consider response modeling as a dynamic alignment problem and model stimulus and response jointly by a mixed pair hidden Markov model (MPH). In MPHs, multiple stimulus-response relationships (e.g., receptive fields) are represented by different states or groups of states in a Markov chain. Each stimulus-response relationship features temporal flexibility, allowing modeling of variable response latencies, including noisy ones. We derive algorithms for learning of MPH parameters and for inference of spike response probabilities. We show that some linear-nonlinear Poisson cascade (LNP) models are a special case of MPHs. We demonstrate the efficiency and usefulness of MPHs in simulations of both jittered and switching spike responses to white noise and natural stimuli. Furthermore, we apply MPHs to extracellular single and multi-unit data recorded in cortical brain areas of singing birds to showcase a novel method for estimating response lag distributions. MPHs allow simultaneous estimation of receptive fields, latency statistics, and hidden state dynamics and so can help to uncover complex stimulus response relationships that are subject to variable timing and involve diverse neural codes. PMID:24625448

  11. 15. Detail showing lower chord pinconnected to vertical member, showing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Detail showing lower chord pin-connected to vertical member, showing floor beam riveted to extension of vertical member below pin-connection, and showing brackets supporting cantilevered sidewalk. View to southwest. - Selby Avenue Bridge, Spanning Short Line Railways track at Selby Avenue between Hamline & Snelling Avenues, Saint Paul, Ramsey County, MN

  12. Laser alignment of rotating equipment at PNL

    SciTech Connect

    Berndt, R.H.

    1994-05-01

    Lateral vibration in direct-drive equipment is usually caused by misalignment. Over the years, because of the need to improve on techniques and ways of working more efficiently, various types of alignment methods have evolved. In the beginning, craftsmen used a straight-edge scale across the coupling with a feeler gauge measuring the misalignment error. This is still preferred today for aligning small couplings. The industry has since decided that alignment of large direct-drive equipment needed a more accurate type of instrumentation. Rim and face is another of the first alignment methods and is used on all sizes of equipment. A disadvantage of the rim and face method is that in most cases the coupling has to be disassembled. This can cause alignment problems when the coupling is reassembled. Also, the rim and face method is not fast enough to work satisfactorily on alignment of thermally hot equipment. Another concern is that the coupling has to be manufactured accurately for correct rim and face readings. Reverse dial alignment is an improvement over the rim and face method, and depending on the operator`s experience, this method can be very accurate. A good training program along with field experience will bring the operator to a proper level of proficiency for a successful program. A hand-held computer with reverse dial calculations in memory is a must for job efficiency. An advantage over the rim and face method is that the coupling is not disassembled and remains locked together. Reverse dial instrumentation measures from both shaft center lines, rather than the coupling surface so the machining of the coupling during manufacture is not a major concern.

  13. Efficient dynamic programming algorithm with prior knowledge for protein β-strand alignment.

    PubMed

    Sabzekar, Mostafa; Naghibzadeh, Mahmoud; Sadri, Javad

    2017-03-21

    One of the main tasks towards the prediction of protein β-sheet structure is to predict the native alignment of β-strands. The alignment of two β-strands defines similar regions that may reflect functional, structural, or evolutionary relationships between them. Therefore, any improvement in β-strands alignment not only reduces the computational search space but also improves β-sheet structure prediction accuracy. To define the alignment scores, previous studies utilized predicted residue-residue contacts (contact maps). However, there are two serious problems using them. First, the precision of contact map prediction techniques, especially for long-range contacts (i.e., β-residues), is still not satisfactory. Second, the residue-residue contact predictors usually utilize general properties of amino acids and disregard the structural features of β-residues. In this paper, we consider β-structure information, which is estimated from protein β-sheet data sets, as alignment scores. However, the predicted contact maps are used as a prior knowledge about residues. They are used for strengthening or weakening the alignment scores in our algorithm. Thus, we can utilize both β-residues and β-structure information in alignment of β-strands. The structure of dynamic programming of the alignment algorithm is changed in order to work with our prior knowledge. Moreover, the Four Russians method is applied to the proposed alignment algorithm in order to reduce the time complexity of the problem. For evaluating the proposed method, we applied it to the state-of-the-art β-sheet structure prediction methods. The experimental results on the BetaSheet916 data set showed significant improvements in the execution time, the accuracy of β-strands' alignment and consequently β-sheet structure prediction accuracy. The results are available at http://conceptsgate.com/BetaSheet.

  14. GLOBAL PEAK ALIGNMENT FOR COMPREHENSIVE TWO-DIMENSIONAL GAS CHROMATOGRAPHY MASS SPECTROMETRY USING POINT MATCHING ALGORITHMS

    PubMed Central

    Deng, Beichuan; Kim, Seongho; Li, Hengguang; Heath, Elisabeth; Zhang, Xiang

    2016-01-01

    Comprehensive two-dimensional gas chromatography coupled with mass spectrometry (GC×GC-MS) has been used to analyze multiple samples in a metabolomics study. However, due to some uncontrollable experimental conditions, such as the differences in temperature or pressure, matrix effects on samples, and stationary phase degradation, there is always a shift of retention times in the two GC columns between samples. In order to correct the retention time shifts in GC×GC-MS, the peak alignment is a crucial data analysis step to recognize the peaks generated by the same metabolite in different samples. Two approaches have been developed for GC×GC-MS data alignment: profile alignment and peak matching alignment. However, these existing alignment methods are all based on a local alignment, resulting that a peak may not be correctly aligned in a dense chromatographic region where many peaks are present in a small region. False alignment will result in false discovery in the downstream statistical analysis. We, therefore, develop a global comparison based peak alignment method using point matching algorithm (PMA-PA) for both homogeneous and heterogeneous data. The developed algorithm PMA-PA first extracts feature points (peaks) in the chromatography and then searches globally the matching peaks in the consecutive chromatography by adopting the projection of rigid and non-rigid transformation. PMA-PA is further applied to two real experimental data sets, showing that PMA-PA is a promising peak alignment algorithm for both homogenous and heterogeneous data in terms of F1 score, although it uses only peak location information. PMID:27650662

  15. Solvent-free fabrication of three dimensionally aligned polycaprolactone microfibers for engineering of anisotropic tissues.

    PubMed

    An, Jia; Chua, Chee Kai; Leong, Kah Fai; Chen, Chih-Hao; Chen, Jyh-Ping

    2012-10-01

    Fabrication of aligned microfiber scaffolds is critical in successful engineering of anisotropic tissues such as tendon, ligaments and nerves. Conventionally, aligned microfiber scaffolds are two dimensional and predominantly fabricated by electrospinning which is solvent dependent. In this paper, we report a novel technique, named microfiber melt drawing, to fabricate a bundle of three dimensionally aligned polycaprolactone microfibers without using any organic solvent. This technique is simple yet effective. It has been demonstrated that polycaprolactone microfibers of 10 μm fiber diameter can be directly drawn from a 2 mm orifice. Orifice diameter, temperature and take-up speed significantly influence the final linear density and fiber diameter of the microfibers. Mechanical test suggests that mechanical properties such as stiffness and breaking force of microfiber bundles can be easily adjusted by the number of fibers. In vitro study shows that these microfibers are able to support the proliferation of human dermal fibroblasts over 7 days. In vivo result of Achilles tendon repair in a rabbit model shows that the microfibers were highly infiltrated by tendon tissue as early as in 1 month, besides, the repaired tendon have a well-aligned tissue structure under the guidance of aligned microfibers. However whether these three dimensionally aligned microfibers can induce three dimensionally aligned cells remains inconclusive.

  16. Using Quasi-Horizontal Alignment in the absence of the actual alignment.

    PubMed

    Banihashemi, Mohamadreza

    2016-10-01

    Horizontal alignment is a major roadway characteristic used in safety and operational evaluations of many facility types. The Highway Safety Manual (HSM) uses this characteristic in crash prediction models for rural two-lane highways, freeway segments, and freeway ramps/C-D roads. Traffic simulation models use this characteristic in their processes on almost all types of facilities. However, a good portion of roadway databases do not include horizontal alignment data; instead, many contain point coordinate data along the roadways. SHRP 2 Roadway Information Database (RID) is a good example of this type of data. Only about 5% of this geodatabase contains alignment information and for the rest, point data can easily be produced. Even though the point data can be used to extract actual horizontal alignment data but, extracting horizontal alignment is a cumbersome and costly process, especially for a database of miles and miles of highways. This research introduces a so called "Quasi-Horizontal Alignment" that can be produced easily and automatically from point coordinate data and can be used in the safety and operational evaluations of highways. SHRP 2 RID for rural two-lane highways in Washington State is used in this study. This paper presents a process through which Quasi-Horizontal Alignments are produced from point coordinates along highways by using spreadsheet software such as MS EXCEL. It is shown that the safety and operational evaluations of the highways with Quasi-Horizontal Alignments are almost identical to the ones with the actual alignments. In the absence of actual alignment the Quasi-Horizontal Alignment can easily be produced from any type of databases that contain highway coordinates such geodatabases and digital maps.

  17. A Possible Astronomically Aligned Monolith at Gardom's Edge

    NASA Astrophysics Data System (ADS)

    Brown, Daniel; Alder, Andy; Bemand, Elizabeth

    2015-05-01

    A unique triangular shaped monolith located within the Peak District National Park at Gardom's Edge could be intentionally astronomically aligned. It is set within a landscape rich in late Neolithic and Bronze Age remains. We show that the stone is most likely in its original orientation owing to its clear signs of erosion and associated to the time period of the late Neolithic. It is tilted towards south and its north side slopes at an angle equal to the maximum altitude of the Sun at mid-summer. This alignment emphasizes the changing declinations of the Sun during the seasons as well as giving an indication of mid-summers day. This functionality is achieved by an impressive display of light and shadow on the north facing side of the monolith. Together with other monuments in the close vicinity the monolith would have represented an ideal marker or social arena for seasonal gatherings for the otherwise dispersed small communities.

  18. Note: O-ring stack system for electron gun alignment

    SciTech Connect

    Park, In-Yong; Cho, Boklae; Han, Cheolsu; Shin, Seungmin; Lee, Dongjun; Ahn, Sang Jung

    2015-01-15

    We present a reliable method for aligning an electron gun which consists of an electron source and lenses by controlling a stack of rubber O-rings in a vacuum condition. The beam direction angle is precisely tilted along two axes by adjusting the height difference of a stack of O-rings. In addition, the source position is shifted in each of three orthogonal directions. We show that the tilting angle and linear shift along the x and y axes as obtained from ten stacked O-rings are ±2.55° and ±2 mm, respectively. This study can easily be adapted to charged particle gun alignment and adjustments of the flange position in a vacuum, ensuring that its results can be useful with regard to electrical insulation between flanges with slight modifications.

  19. Nucleotide sequence alignment using sparse coding and belief propagation.

    PubMed

    Roozgard, Aminmohammad; Barzigar, Nafise; Wang, Shuang; Jiang, Xiaoqian; Ohno-Machado, Lucila; Cheng, Samuel

    2013-01-01

    Advances in DNA information extraction techniques have led to huge sequenced genomes from organisms spanning the tree of life. This increasing amount of genomic information requires tools for comparison of the nucleotide sequences. In this paper, we propose a novel nucleotide sequence alignment method based on sparse coding and belief propagation to compare the similarity of the nucleotide sequences. We used the neighbors of each nucleotide as features, and then we employed sparse coding to find a set of candidate nucleotides. To select optimum matches, belief propagation was subsequently applied to these candidate nucleotides. Experimental results show that the proposed approach is able to robustly align nucleotide sequences and is competitive to SOAPaligner [1] and BWA [2].

  20. Direct growth of aligned carbon nanotubes on bulk metals.

    PubMed

    Talapatra, S; Kar, S; Pal, S K; Vajtai, R; Ci, L; Victor, P; Shaijumon, M M; Kaur, S; Nalamasu, O; Ajayan, P M

    2006-11-01

    There are several advantages of growing carbon nanotubes (CNTs) directly on bulk metals, for example in the formation of robust CNT-metal contacts during growth. Usually, aligned CNTs are grown either by using thin catalyst layers predeposited on substrates or through vapour-phase catalyst delivery. The latter method, although flexible, is unsuitable for growing CNTs directly on metallic substrates. Here we report on the growth of aligned multiwalled CNTs on a metallic alloy, Inconel 600 (Inconel), using vapour-phase catalyst delivery. The CNTs are well anchored to the substrate and show excellent electrical contact with it. These CNT-metal structures were then used to fabricate double-layer capacitors and field-emitter devices, which demonstrated improved performance over previously designed CNT structures. Inconel coatings can also be used to grow CNTs on other metallic substrates. This finding overcomes the substrate limitation for nanotube growth which should assist the development of future CNT-related technologies.

  1. Theory for the alignment of cortical feature maps during development.

    PubMed

    Bressloff, Paul C; Oster, Andrew M

    2010-08-01

    We present a developmental model of ocular dominance column formation that takes into account the existence of an array of intrinsically specified cytochrome oxidase blobs. We assume that there is some molecular substrate for the blobs early in development, which generates a spatially periodic modulation of experience-dependent plasticity. We determine the effects of such a modulation on a competitive Hebbian mechanism for the modification of the feedforward afferents from the left and right eyes. We show how alternating left and right eye dominated columns can develop, in which the blobs are aligned with the centers of the ocular dominance columns and receive a greater density of feedforward connections, thus becoming defined extrinsically. More generally, our results suggest that the presence of periodically distributed anatomical markers early in development could provide a mechanism for the alignment of cortical feature maps.

  2. The QCD axion from aligned axions and diphoton excess

    NASA Astrophysics Data System (ADS)

    Higaki, Tetsutaro; Jeong, Kwang Sik; Kitajima, Naoya; Takahashi, Fuminobu

    2016-04-01

    We argue that the QCD axion can arise from many aligned axions with decay constants much smaller than the conventional axion window. If the typical decay constant is of O (100) GeV to 1 TeV, one or more of the axions or saxions may account for the recently found diphoton excess at ∼ 750 GeV. Our scenario predicts many axions and saxions coupled to gluons with decay constants of order the weak scale, and therefore many collider signatures by heavy axions and saxions will show up at different energy scales. In particular, if the inferred broad decay width is due to multiple axions or saxions, a non-trivial peak structure may become evident when more data is collected. We also discuss cosmological implications of the aligned QCD axion scenario. In the Appendix we give a possible UV completion and argue that the high quality of the Peccei-Quinn symmetry is naturally explained in our scenario.

  3. Note: O-ring stack system for electron gun alignment

    NASA Astrophysics Data System (ADS)

    Park, In-Yong; Cho, Boklae; Han, Cheolsu; Shin, Seungmin; Lee, Dongjun; Ahn, Sang Jung

    2015-01-01

    We present a reliable method for aligning an electron gun which consists of an electron source and lenses by controlling a stack of rubber O-rings in a vacuum condition. The beam direction angle is precisely tilted along two axes by adjusting the height difference of a stack of O-rings. In addition, the source position is shifted in each of three orthogonal directions. We show that the tilting angle and linear shift along the x and y axes as obtained from ten stacked O-rings are ±2.55° and ±2 mm, respectively. This study can easily be adapted to charged particle gun alignment and adjustments of the flange position in a vacuum, ensuring that its results can be useful with regard to electrical insulation between flanges with slight modifications.

  4. Liquid crystal alignment on ZnO nanostructure films

    NASA Astrophysics Data System (ADS)

    Chung, Yueh-Feng; Chen, Mu-Zhe; Yang, Sheng-Hsiung; Jeng, Shie-Chang

    2016-03-01

    The study of liquid crystal (LC) alignment is important for fundamental researches and industrial applications. The tunable pretilt angles of liquid crystal (LC) molecules aligned on the inorganic zinc oxide (ZnO) nanostructure films with controllable surface wettability are demonstrated in this work. The ZnO nanostructure films are deposited on the ITO- glass substrates by the two-steps hydrothermal process, and their wettability can be modified by annealing. Our experimental results show that the pretilt angles of LCs on ZnO nanostructure films can be successfully adjusted over a wide range from ~90° to ~0° as the surface energy on the ZnO nanostructure films changes from ~30 to ~70 mJ/m. Finally we have applied this technique to fabricate a no-bias optically-compensated bend (OCB) LCD with ZnO nanostructure films annealed at 235 °C.

  5. Theory for the alignment of cortical feature maps during development

    NASA Astrophysics Data System (ADS)

    Bressloff, Paul C.; Oster, Andrew M.

    2010-08-01

    We present a developmental model of ocular dominance column formation that takes into account the existence of an array of intrinsically specified cytochrome oxidase blobs. We assume that there is some molecular substrate for the blobs early in development, which generates a spatially periodic modulation of experience-dependent plasticity. We determine the effects of such a modulation on a competitive Hebbian mechanism for the modification of the feedforward afferents from the left and right eyes. We show how alternating left and right eye dominated columns can develop, in which the blobs are aligned with the centers of the ocular dominance columns and receive a greater density of feedforward connections, thus becoming defined extrinsically. More generally, our results suggest that the presence of periodically distributed anatomical markers early in development could provide a mechanism for the alignment of cortical feature maps.

  6. String-fluid transition in systems with aligned anisotropic interactions.

    PubMed

    Brandt, P C; Ivlev, A V; Morfill, G E

    2010-06-21

    Systems with aligned anisotropic interactions between particles exhibit numerous phase transitions. A remarkable example of the fluid phase transition occurring in such systems is the formation of particle strings--the so-called "string" or "chain" fluids. We employ an approach based on the Ornstein-Zernike (OZ) equation, which allows us to calculate structural properties of fluids with aligned anisotropic interactions. We show that the string-fluid transition can be associated with the bifurcation of the "isotropic" correlation length into two distinct scales which characterize the longitudinal and transverse order in string fluids and, hence, may be used as a fingerprint of this transition. The comparison of the proposed OZ theory with the Monte Carlo simulations reveals fairly good agreement.

  7. Spin alignment of stars in old open clusters

    NASA Astrophysics Data System (ADS)

    Corsaro, Enrico; Lee, Yueh-Ning; García, Rafael A.; Hennebelle, Patrick; Mathur, Savita; Beck, Paul G.; Mathis, Stephane; Stello, Dennis; Bouvier, Jérôme

    2017-03-01

    Stellar clusters form by gravitational collapse of turbulent molecular clouds, with up to several thousand stars per cluster1. They are thought to be the birthplace of most stars and therefore play an important role in our understanding of star formation, a fundamental problem in astrophysics2,3. The initial conditions of the molecular cloud establish its dynamical history until the stellar cluster is born. However, the evolution of the cloud's angular momentum during cluster formation is not well understood4. Current observations have suggested that turbulence scrambles the angular momentum of the cluster-forming cloud, preventing spin alignment among stars within a cluster5. Here we use asteroseismology6-8 to measure the inclination angles of spin axes in 48 stars from the two old open clusters NGC 6791 and NGC 6819. The stars within each cluster show strong alignment. Three-dimensional hydrodynamical simulations of proto-cluster formation show that at least 50% of the initial proto-cluster kinetic energy has to be rotational in order to obtain strong stellar-spin alignment within a cluster. Our result indicates that the global angular momentum of the cluster-forming clouds was efficiently transferred to each star and that its imprint has survived several gigayears since the clusters formed.

  8. LCLS Undulator Commissioning, Alignment, and Performance

    SciTech Connect

    Nuhn, Heinz-Dieter

    2009-10-30

    The LCLS x-ray FEL has recently achieved its 1.5-Angstrom lasing and saturation goals upon first trial. This was achieved as a result of a thorough pre-beam checkout, both traditional and beam-based component alignment techniques, and high electron beam brightness. The x-ray FEL process demands very tight tolerances on the straightness of the electron beam trajectory (<5 {micro}m) through the LCLS undulator system. Tight, but less stringent tolerances of {approx}100 {micro}m rms were met for the transverse placement of the individual undulator segments with respect to the beam axis. The tolerances for electron beam straightness can only be met through a beam-based alignment (BBA) method, which is implemented using large electron energy variations and sub-micron resolution cavity beam position monitors (BPM), with precise conventional alignment used to set the starting conditions. Precision-fiducialization of components mounted on remotely adjustable girders, and special beam-finder wires (BFW) at each girder have been used to meet these challenging alignment tolerances. Longer-term girder movement due to ground motion and temperature changes are being monitored, continuously, by a unique stretched wire and hydrostatic level Alignment Diagnostics System (ADS).

  9. Multiple alignment tensors from a denatured protein.

    PubMed

    Gebel, Erika B; Ruan, Ke; Tolman, Joel R; Shortle, David

    2006-07-26

    The structural content of the denatured state has yet to be fully characterized. In recent years, large residual dipolar couplings (RDCs) from denatured proteins have been observed under alignment conditions produced by bicelles and strained polyacrylamide gels. In this report, we describe efforts to extend our picture of the residual structure in denatured nuclease by measuring RDCs with multiple alignment tensors. Backbone amide 15N-1H RDCs were collected from 4 M urea for a total of eight RDC data sets. The RDCs were analyzed by singular value decomposition (SVD) to determine the number of independent alignment tensors present in the data. On the basis of the resultant singular values and propagated error estimates, it is clear that there are at least three independent alignment tensors. These three independent RDC datasets can be reconstituted as orthogonal linear combinations, (OLC)-RDC datasets, of the eight actually recorded. The first, second, and third OLC-RDC datasets are highly robust to the removal of any single experimental RDC dataset, establishing the presence of three independent alignment tensors, sampled well above the level of experimental uncertainty. The observation that the RDC data span three or more dimensions of the five-dimensional parameter space demonstrates that the ensemble average structure of denatured nuclease must be asymmetric with respect to these three orthogonal principal axes, which is not inconsistent with earlier work demonstrating that it has a nativelike topology.

  10. Knee alignment in professional tennis players.

    PubMed

    Maquirriain, Javier

    2002-01-01

    This study determined lower-limb alignment and knee geometry in professional tennis players and compared the data with those from nonathletic individuals. Twenty-four radiographs from 12 asymptomatic players (mean age: 23.4+/-3.8 years) were prospectively studied. The three angles most useful for describing limb alignment and knee geometry in the coronal plane were measured: hip-knee-ankle, condylar-hip, and plateau-ankle. The condylar-plateau angle, frontal foot rotation angle, and the relationship between the mechanical axis and tibial plateau also were calculated. Varus limb alignment was predominant and the mechanical axis passed medially through the knee center; there was increased valgus inclination of the distal femur, varus angulation of the tibial plateau, near parallel alignment of the joint, and exaggerated external foot rotation. Hip-knee-ankle, condylar-hip, plateau-ankle, and frontal foot rotation angles were significantly different (P<.05, two-tailed t test) from previously reported angles of nonathletic individuals. Variations, probably due to repetitive dynamic demands imposed on lower limbs from an early age, seem to involve both femoral condyles and proximal tibial metaphyses, maintaining normal parallel joint alignment.

  11. Alignment and Integration of Lightweight Mirror Segments

    NASA Technical Reports Server (NTRS)

    Evans, Tyler; Biskach, Michael; Mazzarella, Jim; McClelland, Ryan; Saha, Timo; Zhang, Will; Chan, Kai-Wing

    2011-01-01

    The optics for the International X-Ray Observatory (IXO) require alignment and integration of about fourteen thousand thin mirror segments to achieve the mission goal of 3.0 square meters of effective area at 1.25 keV with an angular resolution of five arc-seconds. These mirror segments are 0.4 mm thick, and 200 to 400 mm in size, which makes it difficult not to impart distortion at the sub-arc-second level. This paper outlines the precise alignment, permanent bonding, and verification testing techniques developed at NASA's Goddard Space Flight Center (GSFC). Improvements in alignment include new hardware and automation software. Improvements in bonding include two module new simulators to bond mirrors into, a glass housing for proving single pair bonding, and a Kovar module for bonding multiple pairs of mirrors. Three separate bonding trials were x-ray tested producing results meeting the requirement of sub ten arc-second alignment. This paper will highlight these recent advances in alignment, testing, and bonding techniques and the exciting developments in thin x-ray optic technology development.

  12. 3. Aerial view of turnpike path showing realignment of 1917. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Aerial view of turnpike path showing realignment of 1917. Modernized Orange Turnpike visible running diagonally up from lower left to open area where it veers to the west around the Migel Estate. The beginning of the realignment is located by the cluster of white trailers. Original alignment visible as a row of trees cutting through the base landscape. View looking northwest. - Orange Turnpike, Parallel to new Orange Turnpike, Monroe, Orange County, NY

  13. Business-IT Alignment: A Current-State Evaluation of Strategic Alignment within the Hospital Organization

    ERIC Educational Resources Information Center

    Evers, Kevin W.

    2010-01-01

    More than thirty years of research has shown that the practical value of business-IT alignment is significant and that its importance derives from strategic impact on business outcomes. The purpose of this exploratory study is to identify the current-state of business-IT alignment maturity within the hospital organization. Data for this study was…

  14. TM-align: a protein structure alignment algorithm based on the TM-score

    PubMed Central

    Zhang, Yang; Skolnick, Jeffrey

    2005-01-01

    We have developed TM-align, a new algorithm to identify the best structural alignment between protein pairs that combines the TM-score rotation matrix and Dynamic Programming (DP). The algorithm is ∼4 times faster than CE and 20 times faster than DALI and SAL. On average, the resulting structure alignments have higher accuracy and coverage than those provided by these most often-used methods. TM-align is applied to an all-against-all structure comparison of 10 515 representative protein chains from the Protein Data Bank (PDB) with a sequence identity cutoff <95%: 1996 distinct folds are found when a TM-score threshold of 0.5 is used. We also use TM-align to match the models predicted by TASSER for solved non-homologous proteins in PDB. For both folded and misfolded models, TM-align can almost always find close structural analogs, with an average root mean square deviation, RMSD, of 3 Å and 87% alignment coverage. Nevertheless, there exists a significant correlation between the correctness of the predicted structure and the structural similarity of the model to the other proteins in the PDB. This correlation could be used to assist in model selection in blind protein structure predictions. The TM-align program is freely downloadable at . PMID:15849316

  15. Alignment of Standards and Assessment: A Theoretical and Empirical Study of Methods for Alignment

    ERIC Educational Resources Information Center

    Nasstrom, Gunilla; Henriksson, Widar

    2008-01-01

    Introduction: In a standards-based school-system alignment of policy documents with standards and assessment is important. To be able to evaluate whether schools and students have reached the standards, the assessment should focus on the standards. Different models and methods can be used for measuring alignment, i.e. the correspondence between…

  16. Efficient pairwise RNA structure prediction and alignment using sequence alignment constraints

    PubMed Central

    Dowell, Robin D; Eddy, Sean R

    2006-01-01

    Background We are interested in the problem of predicting secondary structure for small sets of homologous RNAs, by incorporating limited comparative sequence information into an RNA folding model. The Sankoff algorithm for simultaneous RNA folding and alignment is a basis for approaches to this problem. There are two open problems in applying a Sankoff algorithm: development of a good unified scoring system for alignment and folding and development of practical heuristics for dealing with the computational complexity of the algorithm. Results We use probabilistic models (pair stochastic context-free grammars, pairSCFGs) as a unifying framework for scoring pairwise alignment and folding. A constrained version of the pairSCFG structural alignment algorithm was developed which assumes knowledge of a few confidently aligned positions (pins). These pins are selected based on the posterior probabilities of a probabilistic pairwise sequence alignment. Conclusion Pairwise RNA structural alignment improves on structure prediction accuracy relative to single sequence folding. Constraining on alignment is a straightforward method of reducing the runtime and memory requirements of the algorithm. Five practical implementations of the pairwise Sankoff algorithm – this work (Consan), David Mathews' Dynalign, Ian Holmes' Stemloc, Ivo Hofacker's PMcomp, and Jan Gorodkin's FOLDALIGN – have comparable overall performance with different strengths and weaknesses. PMID:16952317

  17. What Are We Aligning Tests to When We Report Test Alignment to the CEFR?

    ERIC Educational Resources Information Center

    Harsch, Claudia; Hartig, Johannes

    2015-01-01

    The study reported here investigates the validity of judgments made when aligning tests to the "Common European Framework of Reference" (CEFR). Listening tests operationalizing pre-defined difficulty-determining characteristics were to be aligned to CEFR levels. We employed a modified version of the item-descriptor-matching-method. Ten…

  18. Alignment of Standards and Assessments as an Accountability Criterion.

    ERIC Educational Resources Information Center

    La Marca, Paul M.

    2001-01-01

    Provides an overview of the concept of alignment and the role it plays in assessment and accountability systems. Discusses some methodological issues affecting the study of alignment and explores the relationship between alignment and test score interpretation. Alignment is not only a methodological requirement but also an ethical requirement.…

  19. MAPPER alignment sensor evaluation on process wafers

    NASA Astrophysics Data System (ADS)

    Vergeer, N.; Lattard, L.; de Boer, G.; Couweleers, F.; Dave, D.; Pradelles, J.; Bustos, J.

    2013-03-01

    MAPPER Lithography is developing a maskless lithography technology based on massively-parallel electron-beam writing. In order to reduce costs and to minimize the footprint of this tool a new alignment sensor has been developed; based on technologies used for DVD optical heads. A wafer with an alignment mark is scanned with the sensor, resulting in an intensity pattern versus position. From this pattern the mark position can be calculated. Evaluations have been made over the performance of this type of sensor using different mark designs at several lithography process steps for FEOL and BEOL manufacturing. It has been shown that sub-nanometer reproducibility (3σ std) of alignment mark readings can be achieved while being robust against various process steps.

  20. Spent fuel container alignment device and method

    DOEpatents

    Jones, Stewart D.; Chapek, George V.

    1996-01-01

    An alignment device is used with a spent fuel shipping container including a plurality of fuel pockets for spent fuel arranged in an annular array and having a rotatable cover including an access opening therein. The alignment device includes a lightweight plate which is installed over the access opening of the cover. A laser device is mounted on the plate so as to emit a laser beam through a laser admittance window in the cover into the container in the direction of a pre-established target associated with a particular fuel pocket. An indexing arrangement on the container provides an indication of the angular position of the rotatable cover when the laser beam produced by the laser is brought into alignment with the target of the associated fuel pocket.

  1. Mechanical alignment of substrates to a mask

    SciTech Connect

    Webb, Aaron P.; Carlson, Charles T.; Honan, Michael; Amato, Luigi G.; Grant, Christopher Neil; Strassner, James D.

    2016-11-08

    A plurality of masks is attached to the underside of a mask frame. This attachment is made such that each mask can independently move relative to the mask frame in three directions. This relative movement allows each mask to adjust its position to align with respective alignment pins disposed on a working surface. In one embodiment, each mask is attached to the mask frame using fasteners, where the fasteners have a shaft with a diameter smaller than the diameter of the mounting hole disposed on the mask. A bias element may be used to allow relative movement between the mask and the mask frame in the vertical direction. Each mask may also have kinematic features to mate with the respective alignment pins on the working surface.

  2. Alignment method for spectrograms of DNA sequences.

    PubMed

    Bucur, Anca; van Leeuwen, Jasper; Dimitrova, Nevenka; Mittal, Chetan

    2010-01-01

    DNA spectrograms express the periodicities of each of the four nucleotides A, T, C, and G in one or several genomic sequences to be analyzed. DNA spectral analysis can be applied to systematically investigate DNA patterns, which may correspond to relevant biological features. As opposed to looking at nucleotide sequences, spectrogram analysis may detect structural characteristics in very long sequences that are not identifiable by sequence alignment. Alignment of DNA spectrograms can be used to facilitate analysis of very long sequences or entire genomes at different resolutions. Standard clustering algorithms have been used in spectral analysis to find strong patterns in spectra. However, as they use a global distance metric, these algorithms can only detect strong patterns coexisting in several frequencies. In this paper, we propose a new method and several algorithms for aligning spectra suitable for efficient spectral analysis and allowing for the easy detection of strong patterns in both single frequencies and multiple frequencies.

  3. Making Macroscopic Assemblies of Aligned Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Smalley, Richard E.; Colbert, Daniel T.; Smith, Ken A.; Walters, Deron A.; Casavant, Michael J.; Qin, Xiaochuan; Yakobson, Boris; Hauge, Robert H.; Saini, Rajesh Kumar; Chiung, Wan-Ting; Huffman, Charles B.

    2005-01-01

    A method of aligning and assembling single-wall carbon nanotubes (SWNTs) to fabricate macroscopic structures has been invented. The method entails suspending SWNTs in a fluid, orienting the SWNTs by use of a magnetic and/or electric field, and then removing the aligned SWNTs from suspension in such a way as to assemble them while maintaining the alignment. SWNTs are essentially tubular extensions of fullerene molecules. It is desirable to assemble aligned SWNTs into macroscopic structures because the common alignment of the SWNTs in such a structure makes it possible to exploit, on a macroscopic scale, the unique mechanical, chemical, and electrical properties that individual oriented SWNTs exhibit at the molecular level. Because of their small size and high electrical conductivity, carbon nanotubes, and especially SWNTs, are useful for making electrical connectors in integrated circuits. Carbon nanotubes can be used as antennas at optical frequencies, and as probes in scanning tunneling microscopes, atomic-force microscopes, and the like. Carbon nanotubes can be used with or instead of carbon black in tires. Carbon nanotubes are useful as supports for catalysts. Ropes of SWNTs are metallic and, as such, are potentially useful in some applications in which electrical conductors are needed - for example, they could be used as additives in formulating electrically conductive paints. Finally, macroscopic assemblies of aligned SWNTs can serve as templates for the growth of more and larger structures of the same type. The great variety of tubular fullerene molecules and of the structures that could be formed by assembling them in various ways precludes a complete description of the present method within the limits of this article. It must suffice to present a typical example of the use of one of many possible variants of the method to form a membrane comprising SWNTs aligned substantially parallel to each other in the membrane plane. The apparatus used in this variant

  4. Active alignment/contact verification system

    DOEpatents

    Greenbaum, William M.

    2000-01-01

    A system involving an active (i.e. electrical) technique for the verification of: 1) close tolerance mechanical alignment between two component, and 2) electrical contact between mating through an elastomeric interface. For example, the two components may be an alumina carrier and a printed circuit board, two mating parts that are extremely small, high density parts and require alignment within a fraction of a mil, as well as a specified interface point of engagement between the parts. The system comprises pairs of conductive structures defined in the surfaces layers of the alumina carrier and the printed circuit board, for example. The first pair of conductive structures relate to item (1) above and permit alignment verification between mating parts. The second pair of conductive structures relate to item (2) above and permit verification of electrical contact between mating parts.

  5. Identifying subset errors in multiple sequence alignments.

    PubMed

    Roy, Aparna; Taddese, Bruck; Vohra, Shabana; Thimmaraju, Phani K; Illingworth, Christopher J R; Simpson, Lisa M; Mukherjee, Keya; Reynolds, Christopher A; Chintapalli, Sree V

    2014-01-01

    Multiple sequence alignment (MSA) accuracy is important, but there is no widely accepted method of judging the accuracy that different alignment algorithms give. We present a simple approach to detecting two types of error, namely block shifts and the misplacement of residues within a gap. Given a MSA, subsets of very similar sequences are generated through the use of a redundancy filter, typically using a 70-90% sequence identity cut-off. Subsets thus produced are typically small and degenerate, and errors can be easily detected even by manual examination. The errors, albeit minor, are inevitably associated with gaps in the alignment, and so the procedure is particularly relevant to homology modelling of protein loop regions. The usefulness of the approach is illustrated in the context of the universal but little known [K/R]KLH motif that occurs in intracellular loop 1 of G protein coupled receptors (GPCR); other issues relevant to GPCR modelling are also discussed.

  6. Purification process for vertically aligned carbon nanofibers

    NASA Technical Reports Server (NTRS)

    Nguyen, Cattien V.; Delziet, Lance; Matthews, Kristopher; Chen, Bin; Meyyappan, M.

    2003-01-01

    Individual, free-standing, vertically aligned multiwall carbon nanotubes or nanofibers are ideal for sensor and electrode applications. Our plasma-enhanced chemical vapor deposition techniques for producing free-standing and vertically aligned carbon nanofibers use catalyst particles at the tip of the fiber. Here we present a simple purification process for the removal of iron catalyst particles at the tip of vertically aligned carbon nanofibers derived by plasma-enhanced chemical vapor deposition. The first step involves thermal oxidation in air, at temperatures of 200-400 degrees C, resulting in the physical swelling of the iron particles from the formation of iron oxide. Subsequently, the complete removal of the iron oxide particles is achieved with diluted acid (12% HCl). The purification process appears to be very efficient at removing all of the iron catalyst particles. Electron microscopy images and Raman spectroscopy data indicate that the purification process does not damage the graphitic structure of the nanotubes.

  7. On the alignment for precession electron diffraction

    PubMed Central

    Liao, Yifeng; Marks, Laurence D.

    2013-01-01

    Precession electron diffraction has seen a fast increase in its adoption as a technique for solving crystallographic structures as well as an alternative to conventional selected-area and converged-beam diffraction methods. One of the key issues of precession is the pivot point alignment, as a stationary apparent beam does not guarantee a fixed pivot point. A large precession tilt angle, along with pre-field and post-field misalignment, induces shift in the image plane. We point out here that the beam should be aligned to the pre-field optic axis to keep the electron illumination stationary during the rocking process. A practical alignment procedure is suggested with the focus placed on minimizing the beam wandering on the specimen, and is demonstrated for a (110)-oriented silicon single crystal and for a carbide phase (~20 nm in size) within a cast cobalt–chromium–molybdenum alloy. PMID:22634134

  8. Prosody and alignment: a sequential perspective

    NASA Astrophysics Data System (ADS)

    Szczepek Reed, Beatrice

    2010-12-01

    In their analysis of a corpus of classroom interactions in an inner city high school, Roth and Tobin describe how teachers and students accomplish interactional alignment by prosodically matching each other's turns. Prosodic matching, and specific prosodic patterns are interpreted as signs of, and contributions to successful interactional outcomes and positive emotions. Lack of prosodic matching, and other specific prosodic patterns are interpreted as features of unsuccessful interactions, and negative emotions. This forum focuses on the article's analysis of the relation between interpersonal alignment, emotion and prosody. It argues that prosodic matching, and other prosodic linking practices, play a primarily sequential role, i.e. one that displays the way in which participants place and design their turns in relation to other participants' turns. Prosodic matching, rather than being a conversational action in itself, is argued to be an interactional practice (Schegloff 1997), which is not always employed for the accomplishment of `positive', or aligning actions.

  9. System and method for 2D workpiece alignment

    DOEpatents

    Weaver, William T.; Carlson, Charles T.; Smith, Scott A.; Beck, Michael A.; Webb, Aaron P.; Strassner, James D.; Gravell, Lawrence R.; Simmons, Michael C.

    2015-07-14

    A carrier capable of holding one or more workpieces is disclosed. The carrier includes movable projections located along the sides of each cell in the carrier. This carrier, in conjunction with a separate alignment apparatus, aligns each workpiece within its respective cell against several alignment pins, using a multiple step alignment process to guarantee proper positioning of the workpiece in the cell. First, the workpieces are moved toward one side of the cell. Once the workpieces have been aligned against this side, the workpieces are then moved toward an adjacent orthogonal side such that the workpieces are aligned to two sides of the cell. Once aligned, the workpiece is held in place by the projections located along each side of each cell. In addition, the alignment pins are also used to align the associated mask, thereby guaranteeing that the mask is properly aligned to the workpiece.

  10. Angle-dependent radiative grain alignment. Confirmation of a magnetic field - radiation anisotropy angle dependence on the efficiency of interstellar grain alignment

    NASA Astrophysics Data System (ADS)

    Andersson, B.-G.; Pintado, O.; Potter, S. B.; Straižys, V.; Charcos-Llorens, M.

    2011-10-01

    Context. Interstellar grain alignment studies are currently experiencing a renaissance due to the development of a new quantitative theory based on radiative alignment torques (RAT). One of the distinguishing predictions of this theory is a dependence of the grain alignment efficiency on the relative angle (Ψ) between the magnetic field and the anisotropy direction of the radiation field. In an earlier study we found observational evidence for such an effect from observations of the polarization around the star HD 97300 in the Chamaeleon I cloud. However, due to the large uncertainties in the measured visual extinctions, the result was uncertain. Aims: By acquiring explicit spectral classification of the polarization targets, we have sought to perform a more precise reanalysis of the existing polarimetry data. Methods: We have obtained new spectral types for the stars in our for our polarization sample, which we combine with photometric data from the literature to derive accurate visual extinctions for our sample of background field stars. This allows a high accuracy test of the grain alignment efficiency as a function of Ψ. Results: We confirm and improve the measured accuracy of the variability of the grain alignment efficiency with Ψ, seen in the earlier study. We note that the grain temperature (heating) also shows a dependence on Ψ which we interpret as a natural effect of the projection of the grain surface to the illuminating radiation source. This dependence also allows us to derive an estimate of the fraction of aligned grains in the cloud.

  11. Backup Alignment Devices on Shuttle: Heads-Up Display or Crew Optical Alignment Sight

    NASA Technical Reports Server (NTRS)

    Chavez, Melissa A.

    2011-01-01

    NASA s Space Shuttle was built to withstand multiple failures while still keeping the crew and vehicle safe. Although the design of the Space Shuttle had a great deal of redundancy built into each system, there were often additional ways to keep systems in the best configuration if a failure were to occur. One such method was to use select pieces of hardware in a way for which they were not primarily intended. The primary function of the Heads-Up Display (HUD) was to provide the crew with a display of flight critical information during the entry phase. The primary function of the Crew Optical Alignment Sight (COAS) was to provide the crew an optical alignment capability for rendezvous and docking phases. An alignment device was required to keep the Inertial Measurement Units (IMUs) well aligned for a safe Entry; nominally this alignment device would be the two on-board Star Trackers. However, in the event of a Star Tracker failure, the HUD or COAS could also be used as a backup alignment device, but only if the device had been calibrated beforehand. Once the HUD or COAS was calibrated and verified then it was considered an adequate backup to the Star Trackers for entry IMU alignment. There were procedures in place and the astronauts were trained on how to accurately calibrate the HUD or COAS and how to use them as an alignment device. The calibration procedure for the HUD and COAS had been performed on many Shuttle missions. Many of the first calibrations performed were for data gathering purposes to determine which device was more accurate as a backup alignment device, HUD or COAS. Once this was determined, the following missions would frequently calibrate the HUD in order to be one step closer to having the device ready in case it was needed as a backup alignment device.

  12. Survey and Alignment of SLAC's B Factory

    SciTech Connect

    Pietryka, Matthew J.; Gaydosh, Michael L.; /SLAC

    2011-09-08

    The survey and alignment of SLAC's B-factory injector and high energy ring will be complete in March 1997. Modern digital electronic surveying tools are contributing to new, efficient alignment procedures. A laser tracker was used to fiducialize almost 300 quadrupole magnets. Digital levels were used to pre-set base plate elevations. Theodolites with very accurate co-axial distance meters were used for everything from layout to 3D magnet positioning to network surveys, all in free stationing mode. A number of procedures and measurement results are outlined.

  13. Fine alignment of a large segmented mirror

    NASA Technical Reports Server (NTRS)

    Dey, Thomas William (Inventor)

    2010-01-01

    A system for aligning a segmented mirror includes a source of radiation directed along a first axis to the segmented mirror and a beamsplitter removably inserted along the first axis for redirecting radiation from the first axis to a second axis, substantially perpendicular to the first axis. An imaging array is positioned along the second axis for imaging the redirected radiation, and a knife-edge configured for cutting the redirected radiation is serially positioned to occlude and not occlude the redirected radiation, effectively providing a variable radiation pattern detected by the imaging array for aligning the segmented mirror.

  14. Drift Chamber Alignment using Cosmic Rays

    SciTech Connect

    Kotwal, Ashutosh V.; Hays, Christopher P.

    2014-05-07

    The Collider Detector at Fermilab (CDF) is a general-purpose experimental apparatus with an inner tracking detector for measuring charged particles, surrounded by a calorimeter for measurements of electromagnetic and hadronic showers, and a muon detector system. We present a technique for, and results of, a precise relative alignment of the drift chamber wires of the CDF tracker. This alignment has been an important component of the track momentum calibration, which is the basis for the charged-lepton calibration for the measurement of the W boson mass at CDF.

  15. Alignment Pins for Assembling and Disassembling Structures

    NASA Technical Reports Server (NTRS)

    Campbell, Oliver C.

    2008-01-01

    Simple, easy-to-use, highly effective tooling has been devised for maintaining alignment of bolt holes in mating structures during assembly and disassembly of the structures. The tooling was originally used during removal of a body flap from the space shuttle Atlantis, in which misalignments during removal of the last few bolts could cause the bolts to bind in their holes. By suitably modifying the dimensions of the tooling components, the basic design of the tooling can readily be adapted to other structures that must be maintained in alignment. The tooling includes tapered, internally threaded alignment pins designed to fit in the bolt holes in one of the mating structures, plus a draw bolt and a cup that are used to install or remove each alignment pin. In preparation for disassembly of two mating structures, external supports are provided to prevent unintended movement of the structures. During disassembly of the structures, as each bolt that joins the structures is removed, an alignment pin is installed in its place. Once all the bolts have been removed and replaced with pins, the pins maintain alignment as the structures are gently pushed or pulled apart on the supports. In assembling the two structures, one reverses the procedure described above: pins are installed in the bolt holes, the structures are pulled or pushed together on the supports, then the pins are removed and replaced with bolts. The figure depicts the tooling and its use. To install an alignment pin in a bolt hole in a structural panel, the tapered end of the pin is inserted from one side of the panel, the cup is placed over the pin on the opposite side of the panel, the draw bolt is inserted through the cup and threaded into the pin, the draw bolt is tightened to pull the pin until the pin is seated firmly in the hole, then the draw bolt and cup are removed, leaving the pin in place. To remove an alignment pin, the cup is placed over the pin on the first-mentioned side of the panel, the draw

  16. Electrospinning of continuous aligned polymer fibers

    NASA Astrophysics Data System (ADS)

    Sundaray, Bibekananda; Subramanian, V.; Natarajan, T. S.; Xiang, Rong-Zheng; Chang, Chia-Cheng; Fann, Wun-Shain

    2004-02-01

    Electrospinning is a technique employed for preparing polymer fibers having diameters in the range of 10 μm-10 nm using high electrostatic field. In this letter, we report the formation of aligned polymer fibers, several centimeters in length, with separation between the fibers in the range of 5-100 μm. Achieving alignment is an important step toward the exploitation of these fibers in applications. We have employed about 4500 V and a separation distance of about 1-3 cm between the electrodes. Smaller distance between electrodes, we believe, provides better control on the formation of the fibers.

  17. Laboratory simulation of field-aligned currents

    NASA Technical Reports Server (NTRS)

    Wessel, Frank J.; Rostoker, Norman

    1993-01-01

    A summary of progress during the period Apr. 1992 to Mar. 1993 is provided. Objectives of the research are (1) to simulate, via laboratory experiments, the three terms of the field-aligned current equation; (2) to simulate auroral-arc formation processes by configuring the boundary conditions of the experimental chamber and plasma parameters to produce highly localized return currents at the end of a field-aligned current system; and (3) to extrapolate these results, using theoretical and computational techniques, to the problem of magnetospheric-ionospheric coupling and to compare them with published literature signatures of auroral-arc phenomena.

  18. Parallel and Scalable Short-Read Alignment on Multi-Core Clusters Using UPC++

    PubMed Central

    González-Domínguez, Jorge; Liu, Yongchao; Schmidt, Bertil

    2016-01-01

    The growth of next-generation sequencing (NGS) datasets poses a challenge to the alignment of reads to reference genomes in terms of alignment quality and execution speed. Some available aligners have been shown to obtain high quality mappings at the expense of long execution times. Finding fast yet accurate software solutions is of high importance to research, since availability and size of NGS datasets continue to increase. In this work we present an efficient parallelization approach for NGS short-read alignment on multi-core clusters. Our approach takes advantage of a distributed shared memory programming model based on the new UPC++ language. Experimental results using the CUSHAW3 aligner show that our implementation based on dynamic scheduling obtains good scalability on multi-core clusters. Through our evaluation, we are able to complete the single-end and paired-end alignments of 246 million reads of length 150 base-pairs in 11.54 and 16.64 minutes, respectively, using 32 nodes with four AMD Opteron 6272 16-core CPUs per node. In contrast, the multi-threaded original tool needs 2.77 and 5.54 hours to perform the same alignments on the 64 cores of one node. The source code of our parallel implementation is publicly available at the CUSHAW3 homepage (http://cushaw3.sourceforge.net). PMID:26731399

  19. Alignments of volcanic features in the southern hemisphere of Mars produced by migrating mantle plumes

    NASA Astrophysics Data System (ADS)

    Leone, Giovanni

    2016-01-01

    Mars shows alignments of volcanic landforms in its southern hemisphere, starting from the equatorial regions and converging towards the South Pole, and visible at global scale. These composite alignments of volcanoes, calderas, shields, vents, heads of valley networks and massifs between the equatorial regions and the southern polar region define twelve different lines, fitted by rhumb lines (loxodromes), that I propose to be the traces of mantle plumes. The morphology of the volcanic centres changes along some of the alignments suggesting different processes of magma emplacement and eruptive style. The diameters of the volcanic centres and of the volcanic provinces are largest at Tharsis and Elysium, directly proportional to the number of alignments starting from them. A minor presence of unaligned volcanic features is observed on the northern lowlands and on the highlands outside the 12 major alignments. The heads of channels commonly interpreted as fluvial valleys are aligned with the other volcanic centres; unaltered olivine is present along their bed-floors, raising severe doubts as to their aqueous origin. Several hypotheses have tried to explain the formation of Tharsis with the migration of a single mantle plume under the Martian lithosphere, but the discovery of twelve alignments, six starting from Tharsis, favours the hypothesis of several mantle plumes as predicted by the model of the Southern Polar Giant Impact (SPGI) and provides a new view on the formation of the volcanic provinces of Mars.

  20. A distributed system for fast alignment of next-generation sequencing data.

    PubMed

    Srimani, Jaydeep K; Wu, Po-Yen; Phan, John H; Wang, May D

    2010-12-01

    We developed a scalable distributed computing system using the Berkeley Open Interface for Network Computing (BOINC) to align next-generation sequencing (NGS) data quickly and accurately. NGS technology is emerging as a promising platform for gene expression analysis due to its high sensitivity compared to traditional genomic microarray technology. However, despite the benefits, NGS datasets can be prohibitively large, requiring significant computing resources to obtain sequence alignment results. Moreover, as the data and alignment algorithms become more prevalent, it will become necessary to examine the effect of the multitude of alignment parameters on various NGS systems. We validate the distributed software system by (1) computing simple timing results to show the speed-up gained by using multiple computers, (2) optimizing alignment parameters using simulated NGS data, and (3) computing NGS expression levels for a single biological sample using optimal parameters and comparing these expression levels to that of a microarray sample. Results indicate that the distributed alignment system achieves approximately a linear speed-up and correctly distributes sequence data to and gathers alignment results from multiple compute clients.

  1. nDSE-based overlay alignment: enabling technology for nano metrology and fabrication

    NASA Astrophysics Data System (ADS)

    Gao, Jun; Picciotto, Carl; Wu, Wei; Park, Inkyu; Tong, William M.

    2006-03-01

    Displacement sensing and estimation (DSE) is important preprocessing task for many image-based processing systems that extract information from multiple images. In last two years, we gained significant insight of the nature of DSE and developed theory and algorithm framework named nanoscale displacement sensing and estimation (nDSE). We also build procedures to apply nDSE to overlay alignment down to the nanoscale. We will introduce two basic theories: Phase Delay Detection (PDD) and Derivatives-based Maximum Likelihood Estimation (DML) and associated DSE algorithms, noticeably Near-Neighbor-Navigation (N-Cubed) algorithm. We presented our best nDSE experimental result of 1 nm (1σ) while tracking 5 nm stepping. To develop nDSE-based nanoscale alignment, we introduced our definition of displacement, alignment and pseudo-displacement. We presented both theoretical and practical procedures to use nDSE to achieve nano-alignment down to the 10s of nano-meters and beyond. Then we compared nDSE-based nano-alignment to other industry standard alignment method and attempt to show the substantial advantages of nDSE based alignment in terms of cost and simplicity of the system design.

  2. Guiding the orientation of smooth muscle cells on random and aligned polyurethane/collagen nanofibers.

    PubMed

    Jia, Lin; Prabhakaran, Molamma P; Qin, Xiaohong; Ramakrishna, Seeram

    2014-09-01

    Fabricating scaffolds that can simulate the architecture and functionality of native extracellular matrix is a huge challenge in vascular tissue engineering. Various kinds of materials are engineered via nano-technological approaches to meet the current challenges in vascular tissue regeneration. During this study, nanofibers from pure polyurethane and hybrid polyurethane/collagen in two different morphologies (random and aligned) and in three different ratios of polyurethane:collagen (75:25; 50:50; 25:75) are fabricated by electrospinning. The fiber diameters of the nanofibrous scaffolds are in the range of 174-453 nm and 145-419 for random and aligned fibers, respectively, where they closely mimic the nanoscale dimensions of native extracellular matrix. The aligned polyurethane/collagen nanofibers expressed anisotropic wettability with mechanical properties which is suitable for regeneration of the artery. After 12 days of human aortic smooth muscle cells culture on different scaffolds, the proliferation of smooth muscle cells on hybrid polyurethane/collagen (3:1) nanofibers was 173% and 212% higher than on pure polyurethane scaffolds for random and aligned scaffolds, respectively. The results of cell morphology and protein staining showed that the aligned polyurethane/collagen (3:1) scaffold promote smooth muscle cells alignment through contact guidance, while the random polyurethane/collagen (3:1) also guided cell orientation most probably due to the inherent biochemical composition. Our studies demonstrate the potential of aligned and random polyurethane/collagen (3:1) as promising substrates for vascular tissue regeneration.

  3. Compensation method for the alignment angle error of a gear axis in profile deviation measurement

    NASA Astrophysics Data System (ADS)

    Fang, Suping; Liu, Yongsheng; Wang, Huiyi; Taguchi, Tetsuya; Takeda, Ryuhei

    2013-05-01

    In the precision measurement of involute helical gears, the alignment angle error of a gear axis, which was caused by the assembly error of a gear measuring machine, will affect the measurement accuracy of profile deviation. A model of the involute helical gear is established under the condition that the alignment angle error of the gear axis exists. Based on the measurement theory of profile deviation, without changing the initial measurement method and data process of the gear measuring machine, a compensation method is proposed for the alignment angle error of the gear axis that is included in profile deviation measurement results. Using this method, the alignment angle error of the gear axis can be compensated for precisely. Some experiments that compare the residual alignment angle error of a gear axis after compensation for the initial alignment angle error were performed to verify the accuracy and feasibility of this method. Experimental results show that the residual alignment angle error of a gear axis included in the profile deviation measurement results is decreased by more than 85% after compensation, and this compensation method significantly improves the measurement accuracy of the profile deviation of involute helical gear.

  4. Alignment for imprint lithography using nDSE and shallow molds

    NASA Astrophysics Data System (ADS)

    Picciotto, Carl; Gao, Jun; Yu, Zhaoning; Wu, Wei

    2009-06-01

    We present a low-cost overlay alignment metrology solution for nanoimprint lithography that uses optical microscopy, displacement-sensing algorithms, and specially-designed imprint molds that include shallow alignment marks that are visible to the optical system but do not pattern the wafer. This innovation reduces measurement distances to near zero, the optimal distance for displacement-sensing algorithms, and allows for alignment marks to occupy the same piece of wafer real estate without interfering in any way, thus saving silicon area. Additionally, the method we present does not require the comparison of alignment marks between the wafer and the mold, thus removing process variations as a variable. We fabricate the shallow-mark molds, show that the shallow alignment marks indeed do not leave a mark on the wafer, and, implementing our nDSE (nanoscale displacement sensing and estimation) techniques, we demonstrate nanoscale alignment to a precision of 35 nm, 1-σ. Given sufficient engineering refinement, we would fully anticipate achieving alignment errors down to the 1 nm range using these methods.

  5. Parallel and Scalable Short-Read Alignment on Multi-Core Clusters Using UPC+.

    PubMed

    González-Domínguez, Jorge; Liu, Yongchao; Schmidt, Bertil

    2016-01-01

    The growth of next-generation sequencing (NGS) datasets poses a challenge to the alignment of reads to reference genomes in terms of alignment quality and execution speed. Some available aligners have been shown to obtain high quality mappings at the expense of long execution times. Finding fast yet accurate software solutions is of high importance to research, since availability and size of NGS datasets continue to increase. In this work we present an efficient parallelization approach for NGS short-read alignment on multi-core clusters. Our approach takes advantage of a distributed shared memory programming model based on the new UPC++ language. Experimental results using the CUSHAW3 aligner show that our implementation based on dynamic scheduling obtains good scalability on multi-core clusters. Through our evaluation, we are able to complete the single-end and paired-end alignments of 246 million reads of length 150 base-pairs in 11.54 and 16.64 minutes, respectively, using 32 nodes with four AMD Opteron 6272 16-core CPUs per node. In contrast, the multi-threaded original tool needs 2.77 and 5.54 hours to perform the same alignments on the 64 cores of one node. The source code of our parallel implementation is publicly available at the CUSHAW3 homepage (http://cushaw3.sourceforge.net).

  6. Effect of alignment of easy axes on dynamic magnetization of immobilized magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Yoshida, Takashi; Matsugi, Yuki; Tsujimura, Naotaka; Sasayama, Teruyoshi; Enpuku, Keiji; Viereck, Thilo; Schilling, Meinhard; Ludwig, Frank

    2017-04-01

    In some biomedical applications of magnetic nanoparticles (MNPs), the particles are physically immobilized. In this study, we explore the effect of the alignment of the magnetic easy axes on the dynamic magnetization of immobilized MNPs under an AC excitation field. We prepared three immobilized MNP samples: (1) a sample in which easy axes are randomly oriented, (2) a parallel-aligned sample in which easy axes are parallel to the AC field, and (3) an orthogonally aligned sample in which easy axes are perpendicular to the AC field. First, we show that the parallel-aligned sample has the largest hysteresis in the magnetization curve and the largest harmonic magnetization spectra, followed by the randomly oriented and orthogonally aligned samples. For example, 1.6-fold increase was observed in the area of the hysteresis loop of the parallel-aligned sample compared to that of the randomly oriented sample. To quantitatively discuss the experimental results, we perform a numerical simulation based on a Fokker-Planck equation, in which probability distributions for the directions of the easy axes are taken into account in simulating the prepared MNP samples. We obtained quantitative agreement between experiment and simulation. These results indicate that the dynamic magnetization of immobilized MNPs is significantly affected by the alignment of the easy axes.

  7. Theory of electrical conductivity and dielectric permittivity of highly aligned graphene-based nanocomposites.

    PubMed

    Xia, Xiaodong; Hao, Jia; Wang, Yang; Zhong, Zheng; Weng, George J

    2017-03-24

    Highly aligned graphene-based nanocomposites are of great interest due to their excellent electrical properties along the aligned direction. Graphene fillers in these composites are not necessarily perfectly aligned, but their orientations are highly confined to a certain angle, with 90-degree giving rise to the randomly oriented state and 0-degree to the perfectly aligned one. Recent experiments have shown that electrical conductivity and dielectric permittivity of highly aligned graphene-polymer nanocomposites are strongly dependent on this distribution angle, but at present no theory seems to exist to address this issue. In this work we present a new effective-medium theory that is derived from the underlying physical process including the effects of graphene orientation, filler loading, aspect ratio, percolation threshold, interfacial tunneling, and Maxwell-Wagner-Sillars polarization, to determine these two properties. The theory is formulated in the context of preferred orientational average. We highlight this new theory with an application to rGO/epoxy nanocomposites, and demonstrate that the calculated in-plane and out-of-plane conductivity and permittivity are in agreement with the experimental data as the range of graphene orientations changes from the randomly oriented to the highly aligned state. We also show that the percolation thresholds of highly aligned graphene nanocomposites are in general different along the planar and the normal directions, but they converge into a single one when the statistical distribution of graphene fillers is spherically symmetric.

  8. Three discontinuous Galerkin schemes for the anisotropic heat conduction equation on non-aligned grids

    NASA Astrophysics Data System (ADS)

    Held, M.; Wiesenberger, M.; Stegmeir, A.

    2016-02-01

    We present and discuss three discontinuous Galerkin (dG) discretizations for the anisotropic heat conduction equation on non-aligned cylindrical grids. Our non-aligned scheme relies on a self-adjoint local dG (LDG) discretization of the elliptic operator. It conserves the energy exactly and converges with arbitrary order. The pollution by numerical perpendicular heat fluxes decreases with superconvergence rates. We compare this scheme with aligned schemes that are based on the flux-coordinate independent approach for the discretization of parallel derivatives. Here, the dG method provides the necessary interpolation. The first aligned discretization can be used in an explicit time-integrator. However, the scheme violates conservation of energy and shows up stagnating convergence rates for very high resolutions. We overcome this partly by using the adjoint of the parallel derivative operator to construct a second self-adjoint aligned scheme. This scheme preserves energy, but reveals unphysical oscillations in the numerical tests, which result in a decreased order of convergence. Both aligned schemes exhibit low numerical heat fluxes into the perpendicular direction and are superior for flute-modes with finite parallel gradients. We build our argumentation on various numerical experiments on all three schemes for a general axisymmetric magnetic field, which is closed by a comparison to the aligned finite difference (FD) schemes of Stegmeir et al. (2014) and Stegmeir et al. (submitted for publication).

  9. Hey Teacher, Your Personality's Showing!

    ERIC Educational Resources Information Center

    Paulsen, James R.

    1977-01-01

    A study of 30 fourth, fifth, and sixth grade teachers and 300 of their students showed that a teacher's age, sex, and years of experience did not relate to students' mathematics achievement, but that more effective teachers showed greater "freedom from defensive behavior" than did less effective teachers. (DT)

  10. Planning a Successful Tech Show

    ERIC Educational Resources Information Center

    Nikirk, Martin

    2011-01-01

    Tech shows are a great way to introduce prospective students, parents, and local business and industry to a technology and engineering or career and technical education program. In addition to showcasing instructional programs, a tech show allows students to demonstrate their professionalism and skills, practice public presentations, and interact…

  11. Influence of the electron source distribution on field-aligned currents

    NASA Astrophysics Data System (ADS)

    Bruening, K.; Goertz, C. K.

    1985-01-01

    The field-aligned current density above a discrete auroral arc has been deduced from the downward electron flux and magnetic field measurements onboard the rocket Porcupine flight 4. Both measurements show that the field-aligned current density is, in spite of decreasing peak energies towards the edge of the arc, about 4 times higher there than in the center of the arc. This can be explained by using the single particle description for an anisotropic electron source distribution.

  12. Precessional Instability in Binary Black Holes with Aligned Spins.

    PubMed

    Gerosa, Davide; Kesden, Michael; O'Shaughnessy, Richard; Klein, Antoine; Berti, Emanuele; Sperhake, Ulrich; Trifirò, Daniele

    2015-10-02

    Binary black holes on quasicircular orbits with spins aligned with their orbital angular momentum have been test beds for analytic and numerical relativity for decades, not least because symmetry ensures that such configurations are equilibrium solutions to the spin-precession equations. In this work, we show that these solutions can be unstable when the spin of the higher-mass black hole is aligned with the orbital angular momentum and the spin of the lower-mass black hole is antialigned. Spins in these configurations are unstable to precession to large misalignment when the binary separation r is between the values r(ud±)=(√(χ(1))±√(qχ(2)))(4)(1-q)(-2)M, where M is the total mass, q≡m(2)/m(1) is the mass ratio, and χ(1) (χ(2)) is the dimensionless spin of the more (less) massive black hole. This instability exists for a wide range of spin magnitudes and mass ratios and can occur in the strong-field regime near the merger. We describe the origin and nature of the instability using recently developed analytical techniques to characterize fully generic spin precession. This instability provides a channel to circumvent astrophysical spin alignment at large binary separations, allowing significant spin precession prior to merger affecting both gravitational-wave and electromagnetic signatures of stellar-mass and supermassive binary black holes.

  13. Alignment method of off-axis RC reflective optical system

    NASA Astrophysics Data System (ADS)

    Xue-min, Zhang; Xing, Song; Zhi-jun, Zhang; Hou, Xiao-hua

    2016-10-01

    Off-axis optical system has a wide application in space optics and remote detective area. The high surface shape accuracy can be ensured with the development of advanced manufacture technique. So the only condition which limits the wide application of off-axis optical system is how to realize the precise alignment of it. Based on a RC reflective optical system whose diameter is 400mm, the alignment method which combines the high resolution initial placement and computer-aided alignment is introduced. By designing a system which can measure the off-axis fabrication and off-axis angle precisely, the high resolution initial placement of off-axis mirror can be ensured with a measurement accuracy of +/-0.05mm and +/-10". The good initial placement can give a good initial state, so the computer-aided model can be converged well. The experiment shows that a system which has a good initial placement could have a good wave aberration of 0.04λ after three times iteration adjustment.

  14. Critical thresholds in flocking hydrodynamics with non-local alignment.

    PubMed

    Tadmor, Eitan; Tan, Changhui

    2014-11-13

    We study the large-time behaviour of Eulerian systems augmented with non-local alignment. Such systems arise as hydrodynamic descriptions of agent-based models for self-organized dynamics, e.g. Cucker & Smale (2007 IEEE Trans. Autom. Control 52, 852-862. (doi:10.1109/TAC.2007.895842)) and Motsch & Tadmor (2011 J. Stat. Phys. 144, 923-947. (doi:10.1007/s10955-011-0285-9)) models. We prove that, in analogy with the agent-based models, the presence of non-local alignment enforces strong solutions to self-organize into a macroscopic flock. This then raises the question of existence of such strong solutions. We address this question in one- and two-dimensional set-ups, proving global regularity for subcritical initial data. Indeed, we show that there exist critical thresholds in the phase space of the initial configuration which dictate the global regularity versus a finite-time blow-up. In particular, we explore the regularity of non-local alignment in the presence of vacuum.

  15. Ultralight anisotropic foams from layered aligned carbon nanotube sheets.

    PubMed

    Faraji, Shaghayegh; Stano, Kelly L; Yildiz, Ozkan; Li, Ang; Zhu, Yuntian; Bradford, Philip D

    2015-10-28

    In this work, we present large scale, ultralight aligned carbon nanotube (CNT) structures which have densities an order of magnitude lower than CNT arrays, have tunable properties and exhibit resiliency after compression. By stacking aligned sheets of carbon nanotubes and then infiltrating with a pyrolytic carbon (PyC), resilient foam-like materials were produced that exhibited complete recovery from 90% compressive strain. With density as low as 3.8 mg cm(-3), the foam structure is over 500 times less dense than bulk graphite. Microscopy revealed that PyC coated the junctions among CNTs, and also increased CNT surface roughness. These changes in the morphology explain the transition from inelastic behavior to foam-like recovery of the layered CNT sheet structure. Mechanical and thermal properties of the foams were tuned for different applications through variation of PyC deposition duration while dynamic mechanical analysis showed no change in mechanical properties over a large temperature range. Observation of a large and linear electrical resistance change during compression of the aligned CNT/carbon (ACNT/C) foams makes strain/pressure sensors a relevant application. The foams have high oil absorption capacities, up to 275 times their own weight, which suggests they may be useful in water treatment and oil spill cleanup. Finally, the ACNT/C foam's high porosity, surface area and stability allow for demonstration of the foams as catalyst support structures.

  16. Iterative alignment of reflector segments using a laser tracker

    NASA Astrophysics Data System (ADS)

    Cabrera Cuevas, Lizeth; Lucero Alvarez, Maribel; Leon-Huerta, Andrea; Hernandez Rios, Emilio; Hernandez Lázaro, Josefina; Tzile Torres, Carlos; Castro Santos, David; Gale, David M.; Wilson, Grant; Narayanan, Gopal; Smith, David R.

    2013-04-01

    The Large Millimeter Telescope (LMT) is a 50m diameter millimetre-wave radio telescope situated on the summit of Sierra Negra, Puebla, at an altitude of 4600 meters. The reflector surface of the LMT currently employs84 segments arranged in three annular rings. Each segment is comprised of 8 precision composite subpanels located on five threaded adjusters. During the current primary surface refurbishment, individual segments are aligned in the telescope basement using a laser tracker. This allows increased spatial resolution in shorter timescales, resulting in the opportunity for improved logistics and increased alignment precision. To perform segment alignment an iterative process is carried out whereby the surface is measured and subpanel deformations are corrected with the goal of 40 microns RMS. In practice we have been able to achieve RMS errors of almost 20 microns, with 35 microns typical. The number of iterations varies from around ten to over 20, depending mainly on the behaviour of the mechanical adjusters that support the individual subpanels. Cross marks scribed on the reflector surface are used as fiducials, because their positions on the paraboloid are well known. Measurement data is processed using a robust curve fitting algorithm which provides a map of the surface showing the subpanel deviations. From this map the required subpanel adjuster movements are calculated allowing surface improvement in a stepwise manner.

  17. UV beam shaper alignment sensitivity: grayscale versus binary designs

    NASA Astrophysics Data System (ADS)

    Lizotte, Todd E.

    2008-08-01

    What defines a good flat top beam shaper? What is more important; an ideal flat top profile or ease of alignment and stability? These are the questions designers and fabricators can not easily define, since they are a function of experience. Anyone can generate a theoretical beam shaper design and model it until it is clear that on paper the design looks good and meets the general needs of the end customer. However, the method of fabrication can add a twist that is not fully understood by either party until the beam shaper is actually tested for the first time in a system and also produced in high volume. This paper provides some insight into how grayscale and binary fabrication methods can produce the same style of beam shaper, with similar beam shaping performance; however provide a result wherein each fabricated design has separate degrees of sensitivity for alignment and stability. The paper will explain the design and fabrication approach for the two units and present alignment and testing data to provide a contrast comparison. Further data will show that over twenty sets of each fabricated design there is a consistency to the sensitivity issue. An understanding of this phenomenon is essential when considering the use of beam shapers on production equipment that is dedicated to producing micron-precision features within high value microelectronic and consumer products. We will present our findings and explore potential explanations and solutions.

  18. Volume visualization of multiple alignment of large genomicDNA

    SciTech Connect

    Shah, Nameeta; Dillard, Scott E.; Weber, Gunther H.; Hamann, Bernd

    2005-07-25

    Genomes of hundreds of species have been sequenced to date, and many more are being sequenced. As more and more sequence data sets become available, and as the challenge of comparing these massive ''billion basepair DNA sequences'' becomes substantial, so does the need for more powerful tools supporting the exploration of these data sets. Similarity score data used to compare aligned DNA sequences is inherently one-dimensional. One-dimensional (1D) representations of these data sets do not effectively utilize screen real estate. As a result, tools using 1D representations are incapable of providing informatory overview for extremely large data sets. We present a technique to arrange 1D data in 3D space to allow us to apply state-of-the-art interactive volume visualization techniques for data exploration. We demonstrate our technique using multi-millions-basepair-long aligned DNA sequence data and compare it with traditional 1D line plots. The results show that our technique is superior in providing an overview of entire data sets. Our technique, coupled with 1D line plots, results in effective multi-resolution visualization of very large aligned sequence data sets.

  19. Generation of field-aligned current in the auroral zone

    NASA Technical Reports Server (NTRS)

    Okuda, Hideo

    1991-01-01

    Generation of a magnetic field-aligned current in the auroral zone connecting the magnetospheric and ionospheric plasmas has been studied by means of a three dimensional particle simulation model. The model is of a magnetostatic variety appropriate for a low beta plasma in which the high frequency transverse displacement current has been eliminated. The simulation model is highly elongated along the magnetic field lines in order to model a highly elongated flux tube in the auroral zone. An enhanced field-aligned current was generated by injection of a magnetospheric plasma across the auroral zone magnetic field at the center of the model. Such a plasma injection may correspond to a plasmoid injection at the geomagnetic tail associated with magnetic reconnection during a substorm or a transverse plasma flow along the low latitude magnetopause boundary layer. The results of the simulations show that the field-aligned current can be enhanced over the thermal current by a factor of 5 - 10 via such injection. Associated with the enhanced current are the electrostatic ion cyclotron waves and shear Alfven waves excited in the auroral zone.

  20. Alignment enhanced photoconductivity in single wall carbon nanotube films.

    PubMed

    Liu, Ye; Lu, Shaoxin; Panchapakesan, Balaji

    2009-01-21

    In this paper we report, for the first time, the alignment enhanced photoconductivity of single wall carbon nanotube films upon laser illumination. The photoconductivity exhibited an increase, decrease or even 'negative' values when the laser spot was on different positions between contact electrodes, showing a 'position' dependent photoconductivity of partially aligned films of carbon nanotubes. Photon induced charge carrier generation in single wall carbon nanotubes and subsequent charge separation across the metal-carbon nanotube contacts is believed to cause the photoconductivity changes. A net photovoltage of approximately 4 mV and a photocurrent of approximately 10 microA were produced under the laser intensity of approximately 273 mW with a quantum efficiency of approximately 7.8% in vacuum. The photocurrent was observed to be in the direction of nanotube alignment. Finally, there was a strong dependence of the polarization of the incident light on the photocurrent and the orientation of the films influenced the dynamics of the rise and fall of the photocurrent. All of these phenomena clearly have significance in the area of design and fabrication of solar cells, micro-opto-mechanical systems and photodetectors based on carbon nanotubes.

  1. Flexible Pilot Contamination Mitigation With Doppler PSD Alignment

    NASA Astrophysics Data System (ADS)

    Luo, Xiliang; Zhang, Xiaoyu

    2016-10-01

    Pilot contamination in the uplink (UL) can severely degrade the channel estimation quality at the base station (BS) in a massive multi-input multi-output (MIMO) system. Thus, it is critical to explore all possible avenues to enable more orthogonal resources for the users to transmit non-interfering UL pilots. In conventional designs, pilot orthogonality typically assumes constant channel gains over time, which limits the amount of orthogonal resources in the case of time-selective channels. To circumvent this constraint, in this paper, we show how to enable orthogonal multiplexing of pilots in the case of Doppler fading by aligning the power spectrum densities (PSD) of different users. From the derived PSD aligning rules, we can see multiple users can be sounded simultaneously without creating/suffering pilot contamination even when these users are experiencing time-varying channels. Furthermore, we provide analytical formulas characterizing the channel estimation mean square error (MSE) performance. Computer simulations further confirm us the PSD alignment can serve as one important decontamination mechanism for the UL pilots in massive MIMO.

  2. Learning Deep Sharable and Structural Detectors for Face Alignment.

    PubMed

    Liu, Hao; Lu, Jiwen; Feng, Jianjiang; Zhou, Jie

    2017-04-01

    Face alignment aims at localizing multiple facial landmarks for a given facial image, which usually suffers from large variances of diverse facial expressions, aspect ratios and partial occlusions, especially when face images were captured in wild conditions. Conventional face alignment methods extract local features and then directly concatenate these features for global shape regression. Unlike these methods which cannot explicitly model the correlation of neighbouring landmarks and motivated by the fact that individual landmarks are usually correlated, we propose a deep sharable and structural detectors (DSSD) method for face alignment. To achieve this, we firstly develop a structural feature learning method to explicitly exploit the correlation of neighbouring landmarks, which learns to cover semantic information to disambiguate the neighbouring landmarks. Moreover, our model selectively learns a subset of sharable latent tasks across neighbouring landmarks under the paradigm of the multi-task learning framework, so that the redundancy information of the overlapped patches can be efficiently removed. To better improve the performance, we extend our DSSD to a recurrent DSSD (R-DSSD) architecture by integrating with the complementary information from multi-scale perspectives. Experimental results on the widely used benchmark datasets show that our methods achieve very competitive performance compared to the state-of-the-arts.

  3. Are Tidal Effects Responsible for Exoplanetary Spin-Orbit Alignment?

    NASA Astrophysics Data System (ADS)

    Li, Gongjie; Winn, Joshua

    2015-12-01

    Obliquities of planet-hosting stars may be clues about the formation of planetary systems. Previous observations led to the hypothesis that for close-in giant planets, spin-orbit alignment is enforced by tidal interactions. Here, we examine two potential problems with this hypothesis. First, Mazeh and coworkers recently used a new technique -- based on the amplitude of starspot-induced photometric variability -- to conclude that spin-orbit alignment is common even for relatively long-period planets, which would not be expected if tides were responsible. We re-examine the data and find a statistically significant correlation between photometric variability and planetary orbital period, which is at least qualitatively consistent with tidal interactions. Second, Rogers and Lin argued against a particular theory for tidal realignment by showing that initially retrograde systems would fail to be re-aligned, in contradiction with the observed prevalence of prograde systems. We present a simple model that overcomes this problem by taking into account the dissipation of inertial waves and the equilibrium tide, as well as magnetic braking. Thus, we find both problems to be less serious than they first appeared, although the tidal model still has shortcomings.

  4. Alignment physics of disks warped by Lense-Thirring precession

    NASA Astrophysics Data System (ADS)

    Krolik, Julian H.; Sorathia, Kareem; Hawley, John F.

    2014-12-01

    Accretion disks occur in a wide variety of astrophysical contexts, from planet formation to accretion onto black holes. For simplicity, they are generally imagined as thin and flat. However, whenever the disk's angular momentum is oblique to the angular momentum of the central object(s), a torque causes rings within the disk to precess, twisting and warping it. Because the torque weakens rapidly with increasing radius, it has long been thought that some unspecified ‘friction’ brings the inner portions of such disks into alignment, while the outer parts remain in their original orientation. Nearly all previous work on this topic has assumed that such a disk's internal stresses can be described by an isotropic viscosity, even though it has been known for more than four decades that fluid viscosity is far too weak to be significant in accretion disks, and for two decades that accretion stresses are actually due to anisotropic MHD turbulence. This paper reviews recent numerical simulation work showing how twisted disks align when their mechanics are described only in terms of real forces, including MHD turbulence. The detailed mechanisms of alignment are identified, the rate at which it occurs is quantified, and the isotropic viscosity model is shown to be in drastic disagreement with the simulation data.

  5. Magnetically aligned H I fibers and the rolling hough transform

    SciTech Connect

    Clark, S. E.; Putman, M. E.; Peek, J. E. G.

    2014-07-01

    We present observations of a new group of structures in the diffuse Galactic interstellar medium (ISM): slender, linear H I features we dub 'fibers' that extend for many degrees at high Galactic latitude. To characterize and measure the extent and strength of these fibers, we present the Rolling Hough Transform, a new machine vision method for parameterizing the coherent linearity of structures in the image plane. With this powerful new tool we show that the fibers are oriented along the interstellar magnetic field as probed by starlight polarization. We find that these low column density (N{sub H} {sub I}≃5×10{sup 18} cm{sup –2}) fiber features are most likely a component of the local cavity wall, about 100 pc away. The H I data we use to demonstrate this alignment at high latitude are from the Galactic Arecibo L-Band Feed Array H I (GALFA-H I) Survey and the Parkes Galactic All Sky Survey. We find better alignment in the higher resolution GALFA-H I data, where the fibers are more visually evident. This trend continues in our investigation of magnetically aligned linear features in the Riegel-Crutcher H I cold cloud, detected in the Southern Galactic Plane Survey. We propose an application of the RHT for estimating the field strength in such a cloud, based on the Chandrasekhar-Fermi method. We conclude that data-driven, quantitative studies of ISM morphology can be very powerful predictors of underlying physical quantities.

  6. Bit-array alignment effect of perpendicular SOMA media

    NASA Astrophysics Data System (ADS)

    Xiao, Peiying; Yuan, Zhimin; Kuan Lee, Hwee; Guo, Guoxiao

    2006-08-01

    One effective way to overcome the superparamagnetic limit of magnetic recording system is to reduce the grain number per bit at given signal-to-noise ratio (SNR) level by using uniformed media grains. The self organized magnetic array (SOMA) is designed to have uniform grains with perfect grain array structure. It is believed that high enough SNR with small number of grains per bit can be acheived. But in the engineering application, the recorded bit on SOMA media may align with the regular array at different locations and angles due to non-grain synchronized writing, skew angle, and circular track. This induces the bit-array alignment effect and degrades system performance of SOMA media. In this paper, the micromagnetic simulation results show that the bit array alignment effect causes large level SNR fluctuation on the same media. The SOMA media is not preferred to be used in the conventional recording configuration. It is only suitable for the configuration of patterned media.

  7. Ontology alignment architecture for semantic sensor Web integration.

    PubMed

    Fernandez, Susel; Marsa-Maestre, Ivan; Velasco, Juan R; Alarcos, Bernardo

    2013-09-18

    Sensor networks are a concept that has become very popular in data acquisition and processing for multiple applications in different fields such as industrial, medicine, home automation, environmental detection, etc. Today, with the proliferation of small communication devices with sensors that collect environmental data, semantic Web technologies are becoming closely related with sensor networks. The linking of elements from Semantic Web technologies with sensor networks has been called Semantic Sensor Web and has among its main features the use of ontologies. One of the key challenges of using ontologies in sensor networks is to provide mechanisms to integrate and exchange knowledge from heterogeneous sources (that is, dealing with semantic heterogeneity). Ontology alignment is the process of bringing ontologies into mutual agreement by the automatic discovery of mappings between related concepts. This paper presents a system for ontology alignment in the Semantic Sensor Web which uses fuzzy logic techniques to combine similarity measures between entities of different ontologies. The proposed approach focuses on two key elements: the terminological similarity, which takes into account the linguistic and semantic information of the context of the entity's names, and the structural similarity, based on both the internal and relational structure of the concepts. This work has been validated using sensor network ontologies and the Ontology Alignment Evaluation Initiative (OAEI) tests. The results show that the proposed techniques outperform previous approaches in terms of precision and recall.

  8. Cell Alignment Driven by Mechanically Induced Collagen Fiber Alignment in Collagen/Alginate Coatings

    PubMed Central

    Chaubaroux, Christophe; Perrin-Schmitt, Fabienne; Senger, Bernard; Vidal, Loïc; Voegel, Jean-Claude; Schaaf, Pierre; Haikel, Youssef; Boulmedais, Fouzia; Lavalle, Philippe

    2015-01-01

    For many years it has been a major challenge to regenerate damaged tissues using synthetic or natural materials. To favor the healing processes after tendon, cornea, muscle, or brain injuries, aligned collagen-based architectures are of utmost interest. In this study, we define a novel aligned coating based on a collagen/alginate (COL/ALG) multilayer film. The coating exhibiting a nanofibrillar structure is cross-linked with genipin for stability in physiological conditions. By stretching COL/ALG-coated polydimethylsiloxane substrates, we developed a versatile method to align the collagen fibrils of the polymeric coating. Assays on cell morphology and alignment were performed to investigate the properties of these films. Microscopic assessments revealed that cells align with the stretched collagen fibrils of the coating. The degree of alignment is tuned by the stretching rate (i.e., the strain) of the COL/ALG-coated elastic substrate. Such coatings are of great interest for strategies that require aligned nanofibrillar biological material as a substrate for tissue engineering. PMID:25658028

  9. Does Syntactic Alignment Effectively Influence How Speakers Are Perceived by Their Conversation Partner?

    PubMed Central

    Schoot, Lotte; Heyselaar, Evelien; Hagoort, Peter; Segaert, Katrien

    2016-01-01

    The way we talk can influence how we are perceived by others. Whereas previous studies have started to explore the influence of social goals on syntactic alignment, in the current study, we additionally investigated whether syntactic alignment effectively influences conversation partners’ perception of the speaker. To this end, we developed a novel paradigm in which we can measure the effect of social goals on the strength of syntactic alignment for one participant (primed participant), while simultaneously obtaining usable social opinions about them from their conversation partner (the evaluator). In Study 1, participants’ desire to be rated favorably by their partner was manipulated by assigning pairs to a Control (i.e., primed participants did not know they were being evaluated) or Evaluation context (i.e., primed participants knew they were being evaluated). Surprisingly, results showed no significant difference in the strength with which primed participants aligned their syntactic choices with their partners’ choices. In a follow-up study, we used a Directed Evaluation context (i.e., primed participants knew they were being evaluated and were explicitly instructed to make a positive impression). However, again, there was no evidence supporting the hypothesis that participants’ desire to impress their partner influences syntactic alignment. With respect to the influence of syntactic alignment on perceived likeability by the evaluator, a negative relationship was reported in Study 1: the more primed participants aligned their syntactic choices with their partner, the more that partner decreased their likeability rating after the experiment. However, this effect was not replicated in the Directed Evaluation context of Study 2. In other words, our results do not support the conclusion that speakers’ desire to be liked affects how much they align their syntactic choices with their partner, nor is there convincing evidence that there is a reliable

  10. Satellite Animation Shows California Storms

    NASA Video Gallery

    This animation of visible and infrared imagery from NOAA's GOES-West satellite shows a series of moisture-laden storms affecting California from Jan. 6 through Jan. 9, 2017. TRT: 00:36 Credit: NASA...

  11. Satellite Movie Shows Erika Dissipate

    NASA Video Gallery

    This animation of visible and infrared imagery from NOAA's GOES-West satellite from Aug. 27 to 29 shows Tropical Storm Erika move through the Eastern Caribbean Sea and dissipate near eastern Cuba. ...

  12. Aligning Technology Education Teaching with Brain Development

    ERIC Educational Resources Information Center

    Katsioloudis, Petros

    2015-01-01

    This exploratory study was designed to determine if there is a level of alignment between technology education curriculum and theories of intellectual development. The researcher compared Epstein's Brain Growth Theory and Piaget's Status of Intellectual Development with technology education curriculum from Australia, England, and the United…

  13. Survey and alignment at the ALS

    SciTech Connect

    Krebs, G.F.; Lauritzen, T.; Thur, W.

    1995-11-01

    This paper describes survey and alignment at the Lawrence Berkeley National Laboratory`s Advanced Light Source (ALS) accelerators from 1993 to 1995. The ALS is a 1.0 - 1.9 GeV electron accelerator producing extremely bright synchrotron light in the UV and soft-X-ray wavelengths. At the ALS, electrons are accelerated in a LINAC to 50 MeV, injected into a booster ring for further acceleration and finally injected into the storage ring. This is shown schematically in Figure 1. The storage ring, some 200 m in circumference, has been run with electron currents above 400 mA with lifetimes as high as 24 hours. The ALS is a third generation light source and requires for efficient storage ring operation, magnets aligned to within 150 mm of their ideal position. To accomplish this a network of monuments was established and their positions measured with respect to one another. The data was reduced using GEONET`` and STAR*NET`` software. Using the monuments as reference points, magnet positions were measured and alignment confirmed using the Kem Electronic Coordinate Determination System (ECDS``). A number of other papers dealing with survey and alignment (S&A) at the ALS have been written that may further elucidate some details of the methods and systems described in this paper.

  14. General Education Reform: Opportunities for Institutional Alignment

    ERIC Educational Resources Information Center

    Fuess, Scott M., Jr.; Mitchell, Nancy D.

    2011-01-01

    General education reform provides strategic opportunities for departments. This article analyzes reform at the University of Nebraska-Lincoln, illustrating how departments could use the reform process to clarify their strategic planning, align with institutional goals, and steer the university closer to departmental objectives. (Contains 1 table.)

  15. Prosody and Alignment: A Sequential Perspective

    ERIC Educational Resources Information Center

    Reed, Beatrice Szczepek

    2010-01-01

    In their analysis of a corpus of classroom interactions in an inner city high school, Roth and Tobin describe how teachers and students accomplish interactional alignment by prosodically matching each other's turns. Prosodic matching, and specific prosodic patterns are interpreted as signs of, and contributions to successful interactional outcomes…

  16. Aligning English Language Testing with Curriculum

    ERIC Educational Resources Information Center

    Palacio, Marcela; Gaviria, Sandra; Brown, James Dean

    2016-01-01

    Frustrations with traditional testing led a group of teachers at the English for adults program at Universidad EAFIT (Colombia) to design tests aligned with the institutional teaching philosophy and classroom practices. This article reports on a study of an item-by-item evaluation of a series of English exams for validity and reliability in an…

  17. EST Reading Curriculum & Instruction: An Alignment Analysis

    ERIC Educational Resources Information Center

    Mohammed, Lubna Ali; Sidek, H. M.

    2015-01-01

    In order for a curriculum to achieve its goals, it is imperative that the curriculum is coherent at all levels. In order to determine the coherency of a curriculum, the alignment of its theoretical underpinning and the label of a curriculum is one of the aspects that can be examined. The purpose of the current study was to examine if the…

  18. Constructing Aligned Assessments Using Automated Test Construction

    ERIC Educational Resources Information Center

    Porter, Andrew; Polikoff, Morgan S.; Barghaus, Katherine M.; Yang, Rui

    2013-01-01

    We describe an innovative automated test construction algorithm for building aligned achievement tests. By incorporating the algorithm into the test construction process, along with other test construction procedures for building reliable and unbiased assessments, the result is much more valid tests than result from current test construction…

  19. Photoionization of aligned molecular excited states

    NASA Astrophysics Data System (ADS)

    Appling, J. R.; White, M. G.; Kessler, W. J.; Fernandez, R.; Poliakoff, E. D.

    1988-02-01

    Photoelectron angular distributions of several excited states of NO have been measured in an effort to better elucidate the role of alignment in resonant multiphoton excitation processes of molecules. In contrast to previous molecular REMPI measurements on NO, (2+1) angular distributions taken for low rotational levels of the E 2Σ+ (4sσ) Rydberg state of NO exhibit complex angular behavior which is characteristic of strong spatial alignment of the optically prepared levels. Photoelectron angular distributions were also found to be strongly branch and J dependent with the lowest rotational levels of the R21+S11 branch exhibiting the full anisotropy expected for an overall three-photon process. Fluorescence anisotropies extracted from complementary two-photon fluorescence angular distribution measurements reveal small, but nonzero alignment in all rotational levels with J>1/2, in contrast to the photoelectron results. Additional photoelectron angular distributions taken for (1+1) REMPI via the A 2Σ+ (3sσ), v=0 state exhibit near ``cos2θ'' distributions characteristic of photoionization of unaligned target states. The observed photoelectron data are qualitatively interpreted on the basis of the angular momentum constraints of the excitation-induced alignment and photoionization dynamics which determine the observable moments in the angular distribution.

  20. P-16 Alignment of Educational Success

    ERIC Educational Resources Information Center

    Sanchez, Jafeth; Thornton, Bill; Usinger, Janet

    2009-01-01

    This paper focuses on the concept of P-16 alignment of educational systems. At a basic level, evidence of school efforts, improved student achievement, and stakeholder support are necessary for effective accountability. The needs and benefits for stakeholders' understanding of P-16 education are addressed, particularly for educational leaders at…

  1. ON ALIGNMENT OF SUN, EARTH, AND SATELLITE

    DTIC Science & Technology

    The results are reported of an investigation of the relations among the launch parameters of an earth satellite and the time and position of alignment of the sun , the earth, and the satellite. The effects of variations of the launch conditions upon the satellite’s time of transit across the solar disc are determined. (Author)

  2. Alignment for Learning: Reorganizing Classrooms and Campuses

    ERIC Educational Resources Information Center

    Tagg, John

    2004-01-01

    Students nowadays are getting mixed messages about the meaning of education. Evidence has emerged that what colleges have been saying to students were not aligned with what colleges have been doing for students. Students found that the values that seemed to drive policy shifted from department to department, course to course, term to term. As a…

  3. Dielectric Properties of Aligned Conducting Polymers

    DTIC Science & Technology

    1991-10-01

    It has been demonstrated that aligned polyacetylene and polyaniline possess remarkably enhanced conductivities. The increase in crystallinity and...and thermal stability compared to other CPs such as polyacetylenes, polythiophenes, and polyaniline . These favorable properties and the commercial...stretch-orientation of BF4- doped PPy films electrochemically deposited at -30,C, 7 pyrrole electropolymerization at a xylene/water interface, 8 and

  4. Scalable cell alignment on optical media substrates.

    PubMed

    Anene-Nzelu, Chukwuemeka G; Choudhury, Deepak; Li, Huipeng; Fraiszudeen, Azmall; Peh, Kah-Yim; Toh, Yi-Chin; Ng, Sum Huan; Leo, Hwa Liang; Yu, Hanry

    2013-07-01

    Cell alignment by underlying topographical cues has been shown to affect important biological processes such as differentiation and functional maturation in vitro. However, the routine use of cell culture substrates with micro- or nano-topographies, such as grooves, is currently hampered by the high cost and specialized facilities required to produce these substrates. Here we present cost-effective commercially available optical media as substrates for aligning cells in culture. These optical media, including CD-R, DVD-R and optical grating, allow different cell types to attach and grow well on them. The physical dimension of the grooves in these optical media allowed cells to be aligned in confluent cell culture with maximal cell-cell interaction and these cell alignment affect the morphology and differentiation of cardiac (H9C2), skeletal muscle (C2C12) and neuronal (PC12) cell lines. The optical media is amenable to various chemical modifications with fibronectin, laminin and gelatin for culturing different cell types. These low-cost commercially available optical media can serve as scalable substrates for research or drug safety screening applications in industry scales.

  5. Thematic Roles, Markedness Alignment and Processing Complexity

    ERIC Educational Resources Information Center

    Lee, Yoonhyoung; Kwon, Youan; Gordon, Peter C.

    2015-01-01

    Two experiments used eye-tracking during reading to investigate the role of the consistency of the relative markedness alignment of noun phrases (NPs) in the processing of complex sentences in Korean. To do so, the animacy of the first NP was varied in both experiments to manipulate the relative markedness of NPs. In addition, case markings of the…

  6. DETECTORS AND EXPERIMENTAL METHODS: Software alignment of the BESIII main drift chamber using the Kalman Filter method

    NASA Astrophysics Data System (ADS)

    Wang, Ji-Ke; Mao, Ze-Pu; Bian, Jian-Ming; Cao, Guo-Fu; Cao, Xue-Xiang; Chen, Shen-Jian; Deng, Zi-Yan; Fu, Cheng-Dong; Gao, Yuan-Ning; He, Kang-Lin; He, Miao; Hua, Chun-Fei; Huang, Bin; Huang, Xing-Tao; Ji, Xiao-Bin; Li, Fei; Li, Hai-Bo; Li, Wei-Dong; Liang, Yu-Tie; Liu, Chun-Xiu; Liu, Huai-Min; Liu, Suo; Liu, Ying-Jie; Ma, Qiu-Mei; Ma, Xiang; Mao, Ya-Jun; Mo, Xiao-Hu; Pan, Ming-Hua; Pang, Cai-Ying; Ping, Rong-Gang; Qin, Ya-Hong; Qiu, Jin-Fa; Sun, Sheng-Sen; Sun, Yong-Zhao; Wang, Liang-Liang; Wen, Shuo-Pin; Wu, Ling-Hui; Xie, Yu-Guang; Xu, Min; Yan, Liang; You, Zheng-Yun; Yuan, Chang-Zheng; Yuan, Ye; Zhang, Bing-Yun; Zhang, Chang-Chun; Zhang, Jian-Yong; Zhang, Xue-Yao; Zhang, Yao; Zheng, Yang-Heng; Zhu, Ke-Jun; Zhu, Yong-Sheng; Zhu, Zhi-Li; Zou, Jia-Heng

    2009-03-01

    Software alignment is quite important for a tracking detector to reach its ultimate position accuracy and momentum resolution. We developed a new alignment algorithm for the BESIII Main Drift Chamber using the Kalman Filter method. Two different types of data which are helix tracks and straight tracks are used to test this algorithm, and the results show that the design and implementation is successful.

  7. Kernel Manifold Alignment for Domain Adaptation.

    PubMed

    Tuia, Devis; Camps-Valls, Gustau

    2016-01-01

    The wealth of sensory data coming from different modalities has opened numerous opportunities for data analysis. The data are of increasing volume, complexity and dimensionality, thus calling for new methodological innovations towards multimodal data processing. However, multimodal architectures must rely on models able to adapt to changes in the data distribution. Differences in the density functions can be due to changes in acquisition conditions (pose, illumination), sensors characteristics (number of channels, resolution) or different views (e.g. street level vs. aerial views of a same building). We call these different acquisition modes domains, and refer to the adaptation problem as domain adaptation. In this paper, instead of adapting the trained models themselves, we alternatively focus on finding mappings of the data sources into a common, semantically meaningful, representation domain. This field of manifold alignment extends traditional techniques in statistics such as canonical correlation analysis (CCA) to deal with nonlinear adaptation and possibly non-corresponding data pairs between the domains. We introduce a kernel method for manifold alignment (KEMA) that can match an arbitrary number of data sources without needing corresponding pairs, just few labeled examples in all domains. KEMA has interesting properties: 1) it generalizes other manifold alignment methods, 2) it can align manifolds of very different complexities, performing a discriminative alignment preserving each manifold inner structure, 3) it can define a domain-specific metric to cope with multimodal specificities, 4) it can align data spaces of different dimensionality, 5) it is robust to strong nonlinear feature deformations, and 6) it is closed-form invertible, which allows transfer across-domains and data synthesis. To authors' knowledge this is the first method addressing all these important issues at once. We also present a reduced-rank version of KEMA for computational

  8. Kernel Manifold Alignment for Domain Adaptation

    PubMed Central

    Tuia, Devis; Camps-Valls, Gustau

    2016-01-01

    The wealth of sensory data coming from different modalities has opened numerous opportunities for data analysis. The data are of increasing volume, complexity and dimensionality, thus calling for new methodological innovations towards multimodal data processing. However, multimodal architectures must rely on models able to adapt to changes in the data distribution. Differences in the density functions can be due to changes in acquisition conditions (pose, illumination), sensors characteristics (number of channels, resolution) or different views (e.g. street level vs. aerial views of a same building). We call these different acquisition modes domains, and refer to the adaptation problem as domain adaptation. In this paper, instead of adapting the trained models themselves, we alternatively focus on finding mappings of the data sources into a common, semantically meaningful, representation domain. This field of manifold alignment extends traditional techniques in statistics such as canonical correlation analysis (CCA) to deal with nonlinear adaptation and possibly non-corresponding data pairs between the domains. We introduce a kernel method for manifold alignment (KEMA) that can match an arbitrary number of data sources without needing corresponding pairs, just few labeled examples in all domains. KEMA has interesting properties: 1) it generalizes other manifold alignment methods, 2) it can align manifolds of very different complexities, performing a discriminative alignment preserving each manifold inner structure, 3) it can define a domain-specific metric to cope with multimodal specificities, 4) it can align data spaces of different dimensionality, 5) it is robust to strong nonlinear feature deformations, and 6) it is closed-form invertible, which allows transfer across-domains and data synthesis. To authors’ knowledge this is the first method addressing all these important issues at once. We also present a reduced-rank version of KEMA for computational

  9. Robust temporal alignment of multimodal cardiac sequences

    NASA Astrophysics Data System (ADS)

    Perissinotto, Andrea; Queirós, Sandro; Morais, Pedro; Baptista, Maria J.; Monaghan, Mark; Rodrigues, Nuno F.; D'hooge, Jan; Vilaça, João. L.; Barbosa, Daniel

    2015-03-01

    Given the dynamic nature of cardiac function, correct temporal alignment of pre-operative models and intraoperative images is crucial for augmented reality in cardiac image-guided interventions. As such, the current study focuses on the development of an image-based strategy for temporal alignment of multimodal cardiac imaging sequences, such as cine Magnetic Resonance Imaging (MRI) or 3D Ultrasound (US). First, we derive a robust, modality-independent signal from the image sequences, estimated by computing the normalized cross-correlation between each frame in the temporal sequence and the end-diastolic frame. This signal is a resembler for the left-ventricle (LV) volume curve over time, whose variation indicates different temporal landmarks of the cardiac cycle. We then perform the temporal alignment of these surrogate signals derived from MRI and US sequences of the same patient through Dynamic Time Warping (DTW), allowing to synchronize both sequences. The proposed framework was evaluated in 98 patients, which have undergone both 3D+t MRI and US scans. The end-systolic frame could be accurately estimated as the minimum of the image-derived surrogate signal, presenting a relative error of 1.6 +/- 1.9% and 4.0 +/- 4.2% for the MRI and US sequences, respectively, thus supporting its association with key temporal instants of the cardiac cycle. The use of DTW reduces the desynchronization of the cardiac events in MRI and US sequences, allowing to temporally align multimodal cardiac imaging sequences. Overall, a generic, fast and accurate method for temporal synchronization of MRI and US sequences of the same patient was introduced. This approach could be straightforwardly used for the correct temporal alignment of pre-operative MRI information and intra-operative US images.

  10. National Orange Show Photovoltaic Demonstration

    SciTech Connect

    Dan Jimenez Sheri Raborn, CPA; Tom Baker

    2008-03-31

    National Orange Show Photovoltaic Demonstration created a 400KW Photovoltaic self-generation plant at the National Orange Show Events Center (NOS). The NOS owns a 120-acre state fairground where it operates an events center and produces an annual citrus fair known as the Orange Show. The NOS governing board wanted to employ cost-saving programs for annual energy expenses. It is hoped the Photovoltaic program will result in overall savings for the NOS, help reduce the State's energy demands as relating to electrical power consumption, improve quality of life within the affected grid area as well as increase the energy efficiency of buildings at our venue. In addition, the potential to reduce operational expenses would have a tremendous effect on the ability of the NOS to service its community.

  11. Multiple Whole Genome Alignments Without a Reference Organism

    SciTech Connect

    Dubchak, Inna; Poliakov, Alexander; Kislyuk, Andrey; Brudno, Michael

    2009-01-16

    Multiple sequence alignments have become one of the most commonly used resources in genomics research. Most algorithms for multiple alignment of whole genomes rely either on a reference genome, against which all of the other sequences are laid out, or require a one-to-one mapping between the nucleotides of the genomes, preventing the alignment of recently duplicated regions. Both approaches have drawbacks for whole-genome comparisons. In this paper we present a novel symmetric alignment algorithm. The resulting alignments not only represent all of the genomes equally well, but also include all relevant duplications that occurred since the divergence from the last common ancestor. Our algorithm, implemented as a part of the VISTA Genome Pipeline (VGP), was used to align seven vertebrate and sixDrosophila genomes. The resulting whole-genome alignments demonstrate a higher sensitivity and specificity than the pairwise alignments previously available through the VGP and have higher exon alignment accuracy than comparable public whole-genome alignments. Of the multiple alignment methods tested, ours performed the best at aligning genes from multigene families?perhaps the most challenging test for whole-genome alignments. Our whole-genome multiple alignments are available through the VISTA Browser at http://genome.lbl.gov/vista/index.shtml.

  12. Multiple whole-genome alignments without a reference organism.

    PubMed

    Dubchak, Inna; Poliakov, Alexander; Kislyuk, Andrey; Brudno, Michael

    2009-04-01

    Multiple sequence alignments have become one of the most commonly used resources in genomics research. Most algorithms for multiple alignment of whole genomes rely either on a reference genome, against which all of the other sequences are laid out, or require a one-to-one mapping between the nucleotides of the genomes, preventing the alignment of recently duplicated regions. Both approaches have drawbacks for whole-genome comparisons. In this paper we present a novel symmetric alignment algorithm. The resulting alignments not only represent all of the genomes equally well, but also include all relevant duplications that occurred since the divergence from the last common ancestor. Our algorithm, implemented as a part of the VISTA Genome Pipeline (VGP), was used to align seven vertebrate and six Drosophila genomes. The resulting whole-genome alignments demonstrate a higher sensitivity and specificity than the pairwise alignments previously available through the VGP and have higher exon alignment accuracy than comparable public whole-genome alignments. Of the multiple alignment methods tested, ours performed the best at aligning genes from multigene families-perhaps the most challenging test for whole-genome alignments. Our whole-genome multiple alignments are available through the VISTA Browser at http://genome.lbl.gov/vista/index.shtml.

  13. Fabrication of aligned nanofibers by electric-field-controlled electrospinning: insulating-block method.

    PubMed

    Hwang, Wontae; Pang, Changhyun; Chae, Heeyeop

    2016-10-28

    Aligned nanofiber arrays and mats were fabricated with an electrospinning process by manipulating the electric field. The electric field was modified by insulating blocks (IBs) that were installed between the nozzle and the substrate as guiding elements to control the trajectory of the electrospinning jet flow. Simulation results showed that the electric field was deformed near the IBs, resulting in confinement of the electrospinning jet between the blocks. The balance of the electric field in the vertical direction and the repulsive force by space charges in the confined electrified jet stream was attributed to the aligned motion of the jet. Aligned arrays of 200 nm thick polyethylene oxide nanofibers were obtained, exhibiting wave-shaped and cross patterns as well as rectilinear patterns. In addition, 40 μm thick quasi-aligned carbon-nanofiber mats with anisotropic electrical property were also attained by this method.

  14. Multiple sequence alignment with arbitrary gap costs: computing an optimal solution using polyhedral combinatorics.

    PubMed

    Althaus, Ernst; Caprara, Alberto; Lenhof, Hans-Peter; Reinert, Knut

    2002-01-01

    Multiple sequence alignment is one of the dominant problems in computational molecular biology. Numerous scoring functions and methods have been proposed, most of which result in NP-hard problems. In this paper we propose for the first time a general formulation for multiple alignment with arbitrary gap-costs based on an integer linear program (ILP). In addition we describe a branch-and-cut algorithm to effectively solve the ILP to optimality. We evaluate the performances of our approach in terms of running time and quality of the alignments using the BAliBase database of reference alignments. The results show that our implementation ranks amongst the best programs developed so far.

  15. Terahertz detectors arrays based on orderly aligned InN nanowires

    NASA Astrophysics Data System (ADS)

    Chen, Xuechen; Liu, Huiqiang; Li, Qiuguo; Chen, Hao; Peng, Rufang; Chu, Sheng; Cheng, Binbin

    2015-08-01

    Nanostructured terahertz detectors employing a single semiconducting nanowire or graphene sheet have recently generated considerable interest as an alternative to existing THz technologies, for their merit on the ease of fabrication and above-room-temperature operation. However, the lack of alignment in nanostructure device hindered their potential toward practical applications. The present work reports ordered terahertz detectors arrays based on neatly aligned InN nanowires. The InN nanostructures (nanowires and nano-necklaces) were achieved by chemical vapor deposition growth, and then InN nanowires were successfully transferred and aligned into micrometer-sized groups by a “transfer-printing” method. Field effect transistors on aligned nanowires were fabricated and tested for terahertz detection purpose. The detector showed good photoresponse as well as low noise level. Besides, dense arrays of such detectors were also fabricated, which rendered a peak responsivity of 1.1 V/W from 7 detectors connected in series.

  16. Wide-Viewing-Angle Hybrid Aligned Nematic Liquid Crystal Cell Controlled by Complex Electric Field

    NASA Astrophysics Data System (ADS)

    Hong, Seung Ho; Kim, Hyang Yul; Kim, Jae-Hyung; Nam, Sang-Hee; Lee, Myong-Hoon; Lee, Seung Hee

    2002-07-01

    We have developed a hybrid aligned nematic liquid crystal (LC) cell driven by a complex electric field. In the device, the pixel electrode exists on the bottom substrate and the counter electrodes exist on the top and bottom substrates such that with a bias voltage both vertical and horizontal fields are generated. The LC molecules are hybrid aligned with homogeneous alignment on the bottom substrate where the alignment direction is coincident with one of the transmission axes of the crossed polarizers. Therefore, the cell appears to be black in the absence of an electric field. When a voltage is applied to obtain a white state, both vertical and horizontal fields enable the LC molecules to rotate with lowered tilt angles than those in the dark state. The device shows a much wider viewing angle than that of the twisted nematic mode, high light efficiency and low driving voltage in electro-optic characteristics.

  17. The Astronomical Significance of 'Nilurallu', the Megalithic Stone Alignment at Murardoddi in Andhra Pradesh, India

    NASA Astrophysics Data System (ADS)

    Rao, N. Kameswara; Thakur, Priya; Mallinathpur, Yogesh

    2011-11-01

    The stone alignment 'Nilurallu' at Murardoddi is a megalithic monument containing standing stones of 12 to 16 feet high that are arranged somewhat in a squarish pattern. This is one of the stone alignments listed by Allchin (1956) as a non-sepulchal array that might have some astronomical connotations. This impressive stone alignment seems to be similar to that at Vibhuthihalli, that was studied earlier, but constructed with much larger stones. The observations conducted by us show that the rows of stones are aligned to the directions of sunrise (and sunset) on calendrically-important events, like equinoxes and solstices. In contrast to Vibhuthihalli, the shadows of stones provide a means of measuring shorter intervals of time

  18. Fabrication of aligned nanofibers by electric-field-controlled electrospinning: insulating-block method

    NASA Astrophysics Data System (ADS)

    Hwang, Wontae; Pang, Changhyun; Chae, Heeyeop

    2016-10-01

    Aligned nanofiber arrays and mats were fabricated with an electrospinning process by manipulating the electric field. The electric field was modified by insulating blocks (IBs) that were installed between the nozzle and the substrate as guiding elements to control the trajectory of the electrospinning jet flow. Simulation results showed that the electric field was deformed near the IBs, resulting in confinement of the electrospinning jet between the blocks. The balance of the electric field in the vertical direction and the repulsive force by space charges in the confined electrified jet stream was attributed to the aligned motion of the jet. Aligned arrays of 200 nm thick polyethylene oxide nanofibers were obtained, exhibiting wave-shaped and cross patterns as well as rectilinear patterns. In addition, 40 μm thick quasi-aligned carbon-nanofiber mats with anisotropic electrical property were also attained by this method.

  19. Shear induced alignment of short nanofibers in 3D printed polymer composites

    NASA Astrophysics Data System (ADS)

    Erdem Yunus, Doruk; Shi, Wentao; Sohrabi, Salman; Liu, Yaling

    2016-12-01

    3D printing of composite materials offers an opportunity to combine the desired properties of composite materials with the flexibility of additive manufacturing in geometric shape and complexity. In this paper, the shear-induced alignment of aluminum oxide nanowires during stereolithography printing was utilized to fabricate a nanowire reinforced polymer composite. To align the fibers, a lateral oscillation mechanism was implemented and combined with wall pattern printing technique to generate shear flow in both vertical and horizontal directions. A series of specimens were fabricated for testing the composite material’s tensile strength. The results showed that mechanical properties of the composite were improved by reinforcement of nanofibers through shear induced alignment. The improvement of tensile strength was approximately ∼28% by aligning the nanowires at 5 wt% (∼1.5% volume fraction) loading of aluminum oxide nanowires.

  20. Origins of enhanced field-aligned current at the edge of an auroral arc

    NASA Astrophysics Data System (ADS)

    Greenspan, M. E.

    1989-09-01

    Consideration is given to observations showing that the upward field-aligned currents associated with auroral arcs are larger at their edges than within the arcs, focusing on the observations made with the Porcupine F4 rocket (Bruning and Geortz, 1985). It is found that an increase in the altitude of the top of the parallel electric field region does not sufficiently explain the increase in the upward field-aligned current at the edge of the arc crossed by the Porcupine F4. Other explanations are discussed, including the adiabatic acceleration of magnetospheric electrons through a field-aligned electrostatic potential. It is suggested that an increase in the density and/or a decrease in the perpendicular temperature of the magnetospheric electron population at the edge of the arc may explain the observed increase in upward field-aligned current.