Sample records for octameric assembly state

  1. Crystal Structure of the Caenorhabditis elegans Apoptosome Reveals an Octameric Assembly of CED-4

    SciTech Connect

    Qi, S.; Li, H.; Pang, Y.; Hu, Q., Liu, Q., Li, H.; Zhou, Y.; He, T.; Liang, Q.; Liu, Y.; Yuan, X.; Luo, G.; Wang, J.; Yan, N.; Shi, Y.

    2010-04-30

    The CED-4 homo-oligomer or apoptosome is required for initiation of programmed cell death in Caenorhabditis elegans by facilitating autocatalytic activation of the CED-3 caspase zymogen. How the CED-4 apoptosome assembles and activates CED-3 remains enigmatic. Here we report the crystal structure of the complete CED-4 apoptosome and show that it consists of eight CED-4 molecules, organized as a tetramer of an asymmetric dimer via a previously unreported interface among AAA{sup +} ATPases. These eight CED-4 molecules form a funnel-shaped structure. The mature CED-3 protease is monomeric in solution and forms an active holoenzyme with the CED-4 apoptosome, within which the protease activity of CED-3 is markedly stimulated. Unexpectedly, the octameric CED-4 apoptosome appears to bind only two, not eight, molecules of mature CED-3. The structure of the CED-4 apoptosome reveals shared principles for the NB-ARC family of AAA{sup +} ATPases and suggests a mechanism for the activation of CED-3.

  2. Anthrax Toxin Receptor Drives Protective Antigen Oligomerization and Stabilizes the Heptameric and Octameric Oligomer by a Similar Mechanism

    Microsoft Academic Search

    Alexander F. Kintzer; Harry J. Sterling; Iok I. Tang; Evan R. Williams; Bryan A. Krantz; Andreas Hofmann

    2010-01-01

    BackgroundAnthrax toxin is comprised of protective antigen (PA), lethal factor (LF), and edema factor (EF). These proteins are individually nontoxic; however, when PA assembles with LF and EF, it produces lethal toxin and edema toxin, respectively. Assembly occurs either on cell surfaces or in plasma. In each milieu, PA assembles into a mixture of heptameric and octameric complexes that bind

  3. The Protective Antigen Component of Anthrax Toxin Forms Functional Octameric Complexes

    PubMed Central

    Kintzer, Alexander F.; Thoren, Katie L.; Sterling, Harry J.; Dong, Ken C.; Feld, Geoffrey K.; Tang, Iok I.; Zhang, Teri T.; Williams, Evan R.; Berger, James M.; Krantz, Bryan A.

    2009-01-01

    The assembly of bacterial toxins and virulence factors is critical to their function, but the regulation of assembly during infection has not been studied. We begin to address this question using anthrax toxin as a model. The protective antigen (PA) component of the toxin assembles into ring-shaped homooligomers that bind the two other enzyme components of the toxin, lethal factor (LF) and edema factor (EF), to form toxic complexes. To disrupt the host, these toxic complexes are endocytosed, such that the PA oligomer forms a membrane-spanning channel that LF and EF translocate through to enter the cytosol. We show using single-channel electrophysiology that PA channels contain two populations of conductance states, which correspond with two different PA pre-channel oligomers observed by electron microscopy—the well-described heptamer and a novel octamer. Mass spectrometry demonstrates that the PA octamer binds four LFs, and assembly routes leading to the octamer are populated with even-numbered, dimeric and tetrameric, PA intermediates. Both heptameric and octameric PA complexes can translocate LF and EF with similar rates and efficiencies. Here we also report a 3.2-Å crystal structure of the PA octamer. The octamer comprises ?20?30% of the oligomers on cells, but outside of the cell, the octamer is more stable than the heptamer under physiological pH. Thus the PA octamer is a physiological, stable, and active assembly state capable of forming lethal toxins that may withstand the hostile conditions encountered in the bloodstream. This assembly mechanism may provide a novel means to control cytotoxicity. PMID:19627991

  4. New York State Assembly

    NSDL National Science Digital Library

    New York (State). Legislature. Assembly.

    1997-01-01

    The New York State Assembly maintains a vt-100 telnet-based Legislative Information System on the Internet. You can read the full text of a bill, check its status in the legislative process, and even browse the sponsor's Memorandum in Support. You can also review Assembly committee and floor calendars, find out when and where public hearings are being held, and explore the state constitution and laws of New York State.

  5. Slow Folding-Unfolding Kinetics of an Octameric ?-Peptide Bundle

    PubMed Central

    Montalvo, Geronda L.; Gai, Feng; Roder, Heinrich; DeGrado, William F.

    2013-01-01

    ?-Peptide foldamers offer attractive frameworks for examining the effect of backbone flexibility on the dynamics of protein folding. Herein, we study the folding-unfolding kinetics of a ?-peptide, Acid-1Y,1 which folds in aqueous solution into an octameric bundle of peptides in a conformation known as the 14-helix. Acid-1Y is comprised exclusively of ?-amino acids, which differ from ?-amino acids by the addition of a single methylene into the backbone. We aim to understand how the additional degree of freedom and increased backbone flexibility in the ?-amino acid affect folding dynamics and to measure folding rates of this octameric ?-peptide. Previously, we found that the T-jump induced relaxation kinetics of a monomeric ?-peptide that forms a monomeric 14-helix occurred on the nanosecond time scale2 and are noticeably slower than a similar alanine-based ?-helical peptide.3 Additionally, in comparison to similar ?-helices, the relaxation rates showed a weaker dependence on temperature. Here, we find that the T-jump induced relaxation kinetics of the octameric ?-peptide occurs on an even slower time scale (minutes) and the unfolding relaxation rates show a large dependence on temperature. These differences indicate that folding energy landscapes of ?-peptide secondary and quaternary structure are markedly distinct from one another and also from their ?-helical counterparts. PMID:24164344

  6. Stability of the octameric structure affects plasminogen-binding capacity of streptococcal enolase.

    PubMed

    Cork, Amanda J; Ericsson, Daniel J; Law, Ruby H P; Casey, Lachlan W; Valkov, Eugene; Bertozzi, Carlo; Stamp, Anna; Jovcevski, Blagojce; Aquilina, J Andrew; Whisstock, James C; Walker, Mark J; Kobe, Bostjan

    2015-01-01

    Group A Streptococcus (GAS) is a human pathogen that has the potential to cause invasive disease by binding and activating human plasmin(ogen). Streptococcal surface enolase (SEN) is an octameric ?-enolase that is localized at the GAS cell surface. In addition to its glycolytic role inside the cell, SEN functions as a receptor for plasmin(ogen) on the bacterial surface, but the understanding of the molecular basis of plasmin(ogen) binding is limited. In this study, we determined the crystal and solution structures of GAS SEN and characterized the increased plasminogen binding by two SEN mutants. The plasminogen binding ability of SENK312A and SENK362A is ~2- and ~3.4-fold greater than for the wild-type protein. A combination of thermal stability assays, native mass spectrometry and X-ray crystallography approaches shows that increased plasminogen binding ability correlates with decreased stability of the octamer. We propose that decreased stability of the octameric structure facilitates the access of plasmin(ogen) to its binding sites, leading to more efficient plasmin(ogen) binding and activation. PMID:25807546

  7. Octamerization is essential for enzymatic function of human UDP-glucose pyrophosphorylase.

    PubMed

    Führing, Jana; Damerow, Sebastian; Fedorov, Roman; Schneider, Julia; Münster-Kühnel, Anja-Katharina; Gerardy-Schahn, Rita

    2013-04-01

    Uridine diphosphate-glucose pyrophosphorylase (UGP) occupies a central position in carbohydrate metabolism in all kingdoms of life, since its product uridine diphosphate-glucose (UDP-glucose) is essential in a number of anabolic and catabolic pathways and is a precursor for other sugar nucleotides. Its significance as a virulence factor in protists and bacteria has given momentum to the search for species-specific inhibitors. These attempts are, however, hampered by high structural conservation of the active site architecture. A feature that discriminates UGPs of different species is the quaternary organization. While UGPs in protists are monomers, di- and tetrameric forms exist in bacteria, and crystal structures obtained for the enzyme from yeast and human identified octameric UGPs. These octamers are formed by contacts between highly conserved amino acids in the C-terminal ?-helix. Still under debate is the question whether octamerization is required for the functionality of the human enzyme. Here, we used single amino acid replacements in the C-terminal ?-helix to interrogate the impact of highly conserved residues on octamer formation and functional activity of human UGP (hUGP). Replacements were guided by the sequence of Arabidopsis thaliana UGP, known to be active as a monomer. Correlating the data obtained in blue native PAGE, size exclusion chromatography and enzymatic activity testing, we prove that the octamer is the active enzyme form. This new insight into structure-function relationships in hUGP does not only improve the understanding of the catalysis of this important enzyme, but in addition broadens the basis for studies aimed at designing drugs that selectively inhibit UGPs from pathogens. PMID:23254995

  8. Using Markov state models to study self-assembly

    NASA Astrophysics Data System (ADS)

    Perkett, Matthew R.; Hagan, Michael F.

    2014-06-01

    Markov state models (MSMs) have been demonstrated to be a powerful method for computationally studying intramolecular processes such as protein folding and macromolecular conformational changes. In this article, we present a new approach to construct MSMs that is applicable to modeling a broad class of multi-molecular assembly reactions. Distinct structures formed during assembly are distinguished by their undirected graphs, which are defined by strong subunit interactions. Spatial inhomogeneities of free subunits are accounted for using a recently developed Gaussian-based signature. Simplifications to this state identification are also investigated. The feasibility of this approach is demonstrated on two different coarse-grained models for virus self-assembly. We find good agreement between the dynamics predicted by the MSMs and long, unbiased simulations, and that the MSMs can reduce overall simulation time by orders of magnitude.

  9. TEMPLATE BASED HIGH PACKING DENSITY ASSEMBLY FOR MICROCHIP SOLID STATE

    E-print Network

    . Thermoelectric cooling using Peltier effect absorbs heat from the substrate at one junction and transfersTEMPLATE BASED HIGH PACKING DENSITY ASSEMBLY FOR MICROCHIP SOLID STATE COOLING APPLICATION Kerwin has been performed to achieve high density parts packing (up to 92%) of thermoelectric cooling

  10. Using Markov State Models to Study Self-Assembly

    NASA Astrophysics Data System (ADS)

    Perkett, Matthew; Hagan, Michael

    2014-03-01

    In recent years, a number of algorithms have been developed to study rare events, which has resulted in paradigm shift from running a few long trajectories to gathering statistics from many shorter trajectories. Running many simulations in parallel to build a Markov State Model (MSM) is one such technique, which has been applied to protein folding with great success. We present an adaptation to the MSM framework that enables its application to a wide range of systems undergoing self-assembly. The feasibility of this approach is demonstrated on two different coarse-grained models for virus self-assembly. We find good agreement between the MSM calculations and brute force long simulations, with up to several orders of magnitude reduction in simulation time.

  11. Novel hexagonal MoS 2 nanoplates formed by solid-state assembly of nanosheets

    NASA Astrophysics Data System (ADS)

    Wu, Zhuangzhi; Wang, Dezhi; Liang, Xun; Sun, Aokui

    2010-06-01

    The MoS 2 nanoplates with hexagonal morphology have been obtained via solid-state assembly of MoS 2 nanosheets, which were prepared by a normal sulfurization method. The solid-state assembly was realized by a simple calcination process, and the annealing temperature played a crucial role in the formation of the final hexagonal nanoplates. A possible mechanism about the solid-state assembly was also proposed.

  12. Creation of photo-modulated multi-state and multi-scale molecular assemblies via binary-state molecular switch

    E-print Network

    Huang, Jianbin

    Creation of photo-modulated multi-state and multi-scale molecular assemblies via binaryth January 2010 DOI: 10.1039/b916721h The creation of photo-modulated multi-state and multi-scale molecular self-assemblies was realized by the ingenuous utilization of a binary-state molecular switch

  13. De-Novo Genome Assembly and its Current State

    E-print Network

    Spang, Rainer

    Biology #12;3 What is genome assembly and why is it hard? Original genome sequence (in multiple copies) Sequence short fragments Reconstruct original sequence from reads Assembler Difficulties: - Genomes TAATTACG TTCAATTCAATT contig: TACGTAATTCA Nodes = k-mers Edges = (k+1)-mers de Bruijn, 1946; Pevzner, 2001

  14. Influence of the Phase State of Self-Assembling Redox Mediators on their Electrochemical Activity

    PubMed Central

    Muller, John P. E.; Aytar, Burcu S.; Kondo, Yukishige; Lynn, David M.; Abbott, Nicholas L.

    2014-01-01

    Self-assembling redox mediators have the potential to be broadly useful in a range of interfacial electrochemical contexts because the oxidation state and state of assembly of the mediator are closely coupled. In this paper, we report an investigation of the self-assembly of single- and double-tailed ferrocenyl amphiphiles (FTMA and BFDMA, respectively) at the surfaces of Pt electrodes and the impact of the dynamic assembled state of the amphiphiles on their rate of oxidation. We conclude that frozen aggregates of BFDMA adsorb to the surfaces of the Pt electrodes, and that slow dynamics of reorganization BFDMA within these aggregates limits the rate of electrooxidation of BFDMA. In contrast, FTMA, while forming assemblies on the surfaces of Pt electrodes, is characterized by fast reorganization dynamics and a corresponding rate of oxidation that is an order of magnitude greater than BFDMA. PMID:24882870

  15. State of art of optimization methods for assembly line design

    Microsoft Academic Search

    Brahim Rekiek; Alexandre Dolgui; Alain Delchambre; Antoneta Bratcu

    2002-01-01

    The problem of optimal design of the assembly lines is considered. The paper is especially focused on the line balancing and resource planning step for the preliminary design stage. A survey of existing methods is given.

  16. Strategies for solid-state NMR investigations of supramolecular assemblies with large subunit sizes

    NASA Astrophysics Data System (ADS)

    Fricke, Pascal; Chevelkov, Veniamin; Shi, Chaowei; Lange, Adam

    2015-04-01

    Solid-state NMR is a versatile tool to study structure and dynamics of insoluble and non-crystalline biopolymers. Supramolecular protein assemblies are formed by self-association of multiple copies of single small-sized proteins. Because of their high degree of local order, solid-state NMR spectra of such systems exhibit an unusually high level of resolution, rendering them an ideal target for solid-state NMR investigations. Recently, our group has solved the structure of one particular supramolecular assembly, the type-iii-secretion-system needle. The needle subunit comprises around 80 residues. Many interesting supramolecular assemblies with unknown structure have subunits larger in size, which requires development of tailored solid-state NMR strategies to address their structures. In this "Perspective" article, we provide a view on different approaches to enhance sensitivity and resolution in biological solid-state NMR with a focus on the possible application to supramolecular assemblies with large subunit sizes.

  17. Dimerization of the CENP-A assembly factor HJURP is required for centromeric nucleosome deposition

    PubMed Central

    Zasadzi?ska, Ewelina; Barnhart-Dailey, Meghan C; Kuich, P Henning J L; Foltz, Daniel R

    2013-01-01

    The epigenetic mark of the centromere is thought to be a unique centromeric nucleosome that contains the histone H3 variant, centromere protein-A (CENP-A). The deposition of new centromeric nucleosomes requires the CENP-A-specific chromatin assembly factor HJURP (Holliday junction recognition protein). Crystallographic and biochemical data demonstrate that the Scm3-like domain of HJURP binds a single CENP-A–histone H4 heterodimer. However, several lines of evidence suggest that HJURP forms an octameric CENP-A nucleosome. How an octameric CENP-A nucleosome forms from individual CENP-A/histone H4 heterodimers is unknown. Here, we show that HJURP forms a homodimer through its C-terminal domain that includes the second HJURP_C domain. HJURP exists as a dimer in the soluble preassembly complex and at chromatin when new CENP-A is deposited. Dimerization of HJURP is essential for the deposition of new CENP-A nucleosomes. The recruitment of HJURP to centromeres occurs independent of dimerization and CENP-A binding. These data provide a mechanism whereby the CENP-A pre-nucleosomal complex achieves assembly of the octameric CENP-A nucleosome through the dimerization of the CENP-A chaperone HJURP. PMID:23771058

  18. Structural and functional characterization of TesB from Yersinia pestis reveals a unique octameric arrangement of hotdog domains.

    PubMed

    Swarbrick, C M D; Perugini, M A; Cowieson, N; Forwood, J K

    2015-04-01

    Acyl-CoA thioesterases catalyse the hydrolysis of the thioester bonds present within a wide range of acyl-CoA substrates, releasing free CoASH and the corresponding fatty-acyl conjugate. The TesB-type thioesterases are members of the TE4 thioesterase family, one of 25 thioesterase enzyme families characterized to date, and contain two fused hotdog domains in both prokaryote and eukaryote homologues. Only two structures have been elucidated within this enzyme family, and much of the current understanding of the TesB thioesterases has been based on the Escherichia coli structure. Yersinia pestis, a highly virulent bacterium, encodes only one TesB-type thioesterase in its genome; here, the structural and functional characterization of this enzyme are reported, revealing unique elements both within the protomer and quaternary arrangements of the hotdog domains which have not been reported previously in any thioesterase family. The quaternary structure, confirmed using a range of structural and biophysical techniques including crystallography, small-angle X-ray scattering, analytical ultracentrifugation and size-exclusion chromatography, exhibits a unique octameric arrangement of hotdog domains. Interestingly, the same biological unit appears to be present in both TesB structures solved to date, and is likely to be a conserved and distinguishing feature of TesB-type thioesterases. Analysis of the Y. pestis TesB thioesterase activity revealed a strong preference for octanoyl-CoA and this is supported by structural analysis of the active site. Overall, the results provide novel insights into the structure of TesB thioesterases which are likely to be conserved and distinguishing features of the TE4 thioesterase family. PMID:25849407

  19. Structural and functional characterization of TesB from Yersinia pestis reveals a unique octameric arrangement of hotdog domains

    PubMed Central

    Swarbrick, C. M. D.; Perugini, M. A.; Cowieson, N.; Forwood, J. K.

    2015-01-01

    Acyl-CoA thioesterases catalyse the hydrolysis of the thioester bonds present within a wide range of acyl-CoA substrates, releasing free CoASH and the corresponding fatty-acyl conjugate. The TesB-type thioesterases are members of the TE4 thioesterase family, one of 25 thioesterase enzyme families characterized to date, and contain two fused hotdog domains in both prokaryote and eukaryote homologues. Only two structures have been elucidated within this enzyme family, and much of the current understanding of the TesB thioesterases has been based on the Escherichia coli structure. Yersinia pestis, a highly virulent bacterium, encodes only one TesB-type thioesterase in its genome; here, the structural and functional characterization of this enzyme are reported, revealing unique elements both within the protomer and quaternary arrangements of the hotdog domains which have not been reported previously in any thioesterase family. The quaternary structure, confirmed using a range of structural and biophysical techniques including crystallography, small-angle X-ray scattering, analytical ultracentrifugation and size-exclusion chromatography, exhibits a unique octameric arrangement of hotdog domains. Interestingly, the same biological unit appears to be present in both TesB structures solved to date, and is likely to be a conserved and distinguishing feature of TesB-type thioesterases. Analysis of the Y. pestis TesB thioesterase activity revealed a strong preference for octanoyl-CoA and this is supported by structural analysis of the active site. Overall, the results provide novel insights into the structure of TesB thioesterases which are likely to be conserved and distinguishing features of the TE4 thioesterase family. PMID:25849407

  20. Solid-State NMR Studies of HIV-1 Capsid Protein Assemblies

    SciTech Connect

    Han, Yun; Ahn, Jinwoo; Concel, Jason; Byeon, In-Ja L.; Gronenborn, Angela M.; Yang, Jun; Polenova, Tatyana E.

    2010-02-17

    In mature HIV-1 virions, the 26.6 kDa CA protein is assembled into a characteristic cone-shaped core (capsid) that encloses the RNA viral genome. The assembled capsid structure is best described by a fullerene cone model that is made up from a hexameric lattice containing a variable number of CA pentamers, thus allowing for closure of tubular or conical structures. In this paper, we present a solid-state NMR analysis of the wild-type HIV-1 CA protein, prepared as conical and spherical assemblies that are stable and are not affected by magic angle spinning of the samples at frequencies between 10 and 25 kHz. Multidimensional homo- and heteronuclear correlation spectra of CA assemblies of uniformly 13C,15Nlabeled CA exhibit narrow lines, indicative of the conformational homogeneity of the protein in these assemblies. For the conical assemblies, partial residue-specific resonance assignments were obtained. Analysis of the NMR spectra recorded for the conical and spherical assemblies indicates that the CA protein structure is not significantly different in the different morphologies. The present results demonstrate that the assemblies of CA protein are amenable to detailed structural analysis by solid-state NMR spectroscopy.

  1. Distinct solid and solution state self-assembly pathways of RADA16-I designer peptide.

    PubMed

    Cormier, Ashley R; Lopez-Majada, Juan M; Alamo, Rufina G; Paravastu, Anant K

    2013-08-01

    Solid state NMR measurements on selectively (13) C-labeled RADA16-I peptide (COCH3 -RADARADARADARADA-NH2 ) were used to obtain new molecular level information on the conversion of ?-helices to ?-sheets through self-assembly in the solid state with increasing temperature. Isotopic labeling at the A4 C? site enabled rapid detection of (13) C NMR signals. Heating to 344-363?K with simultaneous NMR detection allowed production of samples with systematic variation of ?-helix and ?-strand content. These samples were then probed at room temperature for intermolecular (13) C-(13) C nuclear dipolar couplings with the PITHIRDS-CT NMR experiment. The structural transition was also characterized by Fourier transform infrared spectroscopy and wide angle X-ray diffraction. Independence of PITHIRDS-CT decay shapes on overall ?-helical and ?-strand content infers that ?-strands are not observed without association with ?-sheets, indicating that ?-sheets are formed at elevated temperatures on a timescale that is fast relative to the NMR experiment. PITHIRDS-CT NMR data were compared with results of similar measurements on RADA16-I nanofibers produced by self-assembly in aqueous salt solution. We report that ?-sheets formed through self-assembly in the solid state have a structure that differs from those formed through self-assembly in the solution state. Specifically, solid state RADA16-I self-assembly produces in-register parallel ?-sheets, whereas nanofibers are composed of stacked parallel ?-sheets with registry shifts between adjacent ?-strands in each ?-sheet. These results provide evidence for environment-dependent self-assembly mechanisms for RADA16-I ?-sheets as well as new constraints on solid state self-assembled structures, which must be avoided to maximize solution solubility and nanofiber yields. PMID:23801546

  2. Solid-State Electrochromic Devices via Ionic Self-Assembled Multilayers

    E-print Network

    Heflin, Randy

    Solid-State Electrochromic Devices via Ionic Self-Assembled Multilayers (ISAM) of a Polyviologena-Galva´n, Harry W. Gibson, James R. Heflin* Introduction Electrochromic (EC) devices undergo reversible absorbance/ transmittance change on application of external voltage.[1] Since the first major report on electrochromism

  3. Diagnostics of the state of aircraft parts and assemblies with radionuclide computer tomography

    SciTech Connect

    Kuzelev, N.R.; Maklashevskii, V.Ya.; Yumashev, V.M.; Ivanov, I.V.

    1995-04-01

    The article analyzes the possibilities and demonstrates the expediency of using radionuclide computer tomography for the diagnostics of the state of aircraft parts and assemblies. On the basis of the model and experimental investigations the authors chose the conditions and optimal regimes of measurement for detecting typical defects and checking structural elements in aircraft assemblies such as connectors, valves, elements of electrical devices and of load-bearing structures. The obtained results can be used for devising methods and means of nondestructive testing of industrial products.

  4. Premitotic Assembly of Human CENPs -T and -W Switches Centromeric Chromatin to a Mitotic State

    PubMed Central

    Prendergast, Lisa; van Vuuren, Chelly; Kaczmarczyk, Agnieszka; Doering, Volker; Hellwig, Daniela; Quinn, Nadine; Hoischen, Christian; Diekmann, Stephan; Sullivan, Kevin F.

    2011-01-01

    Centromeres are differentiated chromatin domains, present once per chromosome, that direct segregation of the genome in mitosis and meiosis by specifying assembly of the kinetochore. They are distinct genetic loci in that their identity in most organisms is determined not by the DNA sequences they are associated with, but through specific chromatin composition and context. The core nucleosomal protein CENP-A/cenH3 plays a primary role in centromere determination in all species and directs assembly of a large complex of associated proteins in vertebrates. While CENP-A itself is stably transmitted from one generation to the next, the nature of the template for centromere replication and its relationship to kinetochore function are as yet poorly understood. Here, we investigate the assembly and inheritance of a histone fold complex of the centromere, the CENP-T/W complex, which is integrated with centromeric chromatin in association with canonical histone H3 nucleosomes. We have investigated the cell cycle regulation, timing of assembly, generational persistence, and requirement for function of CENPs -T and -W in the cell cycle in human cells. The CENP-T/W complex assembles through a dynamic exchange mechanism in late S-phase and G2, is required for mitosis in each cell cycle and does not persist across cell generations, properties reciprocal to those measured for CENP-A. We propose that the CENP-A and H3-CENP-T/W nucleosome components of the centromere are specialized for centromeric and kinetochore activities, respectively. Segregation of the assembly mechanisms for the two allows the cell to switch between chromatin configurations that reciprocally support the replication of the centromere and its conversion to a mitotic state on postreplicative chromatin. PMID:21695110

  5. Solid state self-assembly mechanism of RADA16-I designer peptide.

    PubMed

    Cormier, Ashley R; Ruiz-Orta, Carolina; Alamo, Rufina G; Paravastu, Anant K

    2012-06-11

    We report that synthetic RADA16-I peptide transforms to ?-strand secondary structure and develops intermolecular organization into ?-sheets when stored in the solid state at room temperature. Secondary structural changes were probed using solid state nuclear magnetic resonance spectroscopy (ssNMR) and Fourier transform infrared spectroscopy (FTIR). Intermolecular organization was analyzed via wide-angle X-ray diffraction (WAXD). Observed changes in molecular structure and organization occurred on the time scale of weeks during sample storage at room temperature. We observed structural changes on faster time scales by heating samples above room temperature or by addition of water. Analysis of hydration effects indicates that water can enhance the ability of the peptide to convert to ?-strand secondary structure and assemble into ?-sheets. However, temperature dependent FTIR and time dependent WAXD data indicate that bound water may hinder the assembly of ?-strands into ?-sheets. We suggest that secondary structural transformation and intermolecular organization together produce a water-insoluble state. These results reveal insights into the role of water in self-assembly of polypeptides with hydrophilic side chains, and have implications on future optimization of RADA16-I nanofiber production. PMID:22559149

  6. Intramolecular [2 + 2] Photodimerization Achieved in the Solid State via Coordination-Driven Self-Assembly.

    PubMed

    Laird, Rebecca C; Sinnwell, Michael A; Nguyen, Nam P; Swenson, Dale C; Mariappan, S V Santhana; MacGillivray, Leonard R

    2015-07-01

    An intramolecular [2 + 2] photocycloaddition is achieved in the organic solid state via self-assembly of Ag(I) ions and an endo-ditopic bipyridine. The cations aide to organize carbon-carbon double (C?C) bonds attached to the bipyridine for the cycloaddition reaction. The C?C bonds react regioselectively and quantitatively to afford a photoproduct with edge-sharing four-, five-, and six-membered rings. Our study demonstrates the first use of a metal-organic template to direct an intramolecular [2 + 2] photodimerization in the organic solid state. PMID:26079149

  7. Synthesis of ?-Glucan in Mycobacteria Involves a Hetero-octameric Complex of Trehalose Synthase TreS and Maltokinase Pep2

    PubMed Central

    2013-01-01

    Recent evidence established that the cell envelope of Mycobacterium tuberculosis, the bacillus causing tuberculosis (TB), is coated by an ?-glucan-containing capsule that has been implicated in persistence in a mouse infection model. As one of three known metabolic routes to ?-glucan in mycobacteria, the cytoplasmic GlgE-pathway converts trehalose to ?(1 ? 4),?(1 ? 6)-linked glucan in 4 steps. Whether individual reaction steps, catalyzed by trehalose synthase TreS, maltokinase Pep2, and glycosyltransferases GlgE and GlgB, occur independently or in a coordinated fashion is not known. Here, we report the crystal structure of M. tuberculosis TreS, and show by small-angle X-ray scattering and analytical ultracentrifugation that TreS forms tetramers in solution. Together with Pep2, TreS forms a hetero-octameric complex, and we demonstrate that complex formation markedly accelerates maltokinase activity of Pep2. Thus, complex formation may act as part of a regulatory mechanism of the GlgE pathway, which overall must avoid accumulation of toxic pathway intermediates, such as maltose-1-phosphate, and optimize the use of scarce nutrients. PMID:23901909

  8. Steady-State Thermal Performance Evaluation of Steel-Framed Wall Assembly with Local Foam Insulation

    SciTech Connect

    Kosny, Jan [ORNL] [ORNL; Biswas, Kaushik [ORNL] [ORNL; Childs, Phillip W [ORNL] [ORNL

    2010-01-01

    During January and May, 2009, two configurations of steel-framed walls constructed with conventional 2 4 steel studs insulated with R-19 ~14cm. (5.5-in. thick) and R-13 ~9cm. (3.5-in. thick) fiberglass insulation batts were tested in the Oak Ridge National Laboratory (ORNL) guarded hot-box using ASTM C1363 test procedure. The first test wall used conventional 2 4 steel studs insulated with 2.5-cm. (1-in.) thick foam profiles, called stud snugglers. These stud snugglers converted the 2 4 wall assembly into a 2 6 assembly allowing application of R-19 fiberglass insulation. The second wall tested for comparison was a conventional 2 4 steel stud wall using R-13 insulation batts. Further, numerical simulations were performed in order to evaluate the steady-state thermal performance of various wood- and steel-framed wall assemblies. The effects of adding the stud-snugglers to the wood and steel studs were also investigated numerically. Different combinations of insulation and framing factor were used in the simulations.

  9. Steady state temperature profiles in two simulated liquid metal reactor fuel assemblies with identical design specifications

    SciTech Connect

    Levin, A.E.; Carbajo, J.J.; Lloyd, D.B.; Montgomery, B.H.; Rose, S.D.; Wantland, J.L.

    1985-01-01

    Temperature data from steady state tests in two parallel, simulated liquid metal reactor fuel assemblies with identical design specifications have been compared to determine the extent to which they agree. In general, good agreement was found in data at low flows and in bundle-center data at higher flows. Discrepancies in the data wre noted near the bundle edges at higher flows. An analysis of bundle thermal boundary conditions showed that the possible eccentric placement of one bundle within the housing could account for these discrepancies.

  10. Encapsulated discrete octameric water cluster, 1D water tape, and 3D water aggregate network in diverse MOFs based on bisimidazolium ligands

    NASA Astrophysics Data System (ADS)

    Shi, Ruo-Bing; Pi, Min; Jiang, Shuang-Shuang; Wang, Yuan-Yuan; Jin, Chuan-Ming

    2014-08-01

    Four new metal-organic frameworks, [Zn(2-mBIM)2(SO3CF3)2·(H2O)4] (1), [Zn(BMIE)(1,4-BDC)]·(H2O)3 (2), [Cd(BIM)2(OH)(H2O)2(PF6)]·(H2O)4 (3), and [Cd(PA-BIM)2 (ClO4)2]·11.33H2O (4) (2-mBIM = bis(2-methylimidazol-1-yl)methane, BMIE = 1,2-bis[1-(2-methylimidazole)-diethoxy]ethane, BIM = bis(imidazol-1-yl)methane, and PA-BIM = 1,1-bis [(2-phenylazo)imidazol-1-yl]methane) have been prepared and structurally characterized. Complex 1 exhibits an infinite 1D cationic beaded-chain structure, which encapsulated discrete octameric water clusters that are comprised of a chair-like hexameric water cluster with two extra water molecules dangling on two diagonal vertices of the chair. Complex 2 forms a 1D infinite zigzag metal-organic chain structure with a 1D T4(0)A(4) water tape. Complexes 3 show a 2D grid-like sheet structure with the 1D water tape T4(0)A(0)2(0) motif. Complex 4 is a porous 3D MOF with tetrahedron-coordinated Cd(II) centers and trans-conformation PA-BIM ligands. These holes are occupied by a fascinating three-dimensional water clathrate network, which consists of cage-shaped structural tetradecameric water cluster (H2O)14 units and six independent bridged water molecules. The results suggest that the bisimidazolium ligands and anions play crucial roles in the formation of the different host structures and different guest water aggregations. Additionally, the thermal stabilities and photoluminescence spectra of the complexes have been discussed.

  11. State-of-the-art exact and heuristic solution procedures for simple assembly line balancing

    Microsoft Academic Search

    Armin Scholl; Christian Becker

    2006-01-01

    The assembly line balancing problem arises and has to be solved when an assembly line has to be configured or redesigned. It consists of distributing the total workload for manufacturing any unit of the product to be assembled among the work stations along the line. The so-called simple assembly line balancing problem (SALBP), a basic version of the general problem,

  12. Self-assembled nanowire array capacitors: capacitance and interface state profile

    NASA Astrophysics Data System (ADS)

    Li, Qiliang; Xiong, Hao D.; Liang, Xuelei; Zhu, Xiaoxiao; Gu, Diefeng; Ioannou, Dimitris E.; Baumgart, Helmut; Richter, Curt A.

    2014-04-01

    Direct characterization of the capacitance and interface states is very important for understanding the electronic properties of a nanowire transistor. However, the capacitance of a single nanowire is too small to precisely measure. In this work we have fabricated metal-oxide-semiconductor capacitors based on a large array of self-assembled Si nanowires. The capacitance and conductance of the nanowire array capacitors are directly measured and the interface state profile is determined by using the conductance method. We demonstrate that the nanowire array capacitor is an effective platform for studying the electronic properties of nanoscale interfaces. This approach provides a useful and efficient metrology for the study of the physics and device properties of nanoscale metal-oxide-semiconductor structures.

  13. 19 CFR 10.25 - Textile components cut to shape in the United States and assembled abroad.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Textile components cut to shape in the United...United States Components § 10.25 Textile components cut to shape in the United States and assembled abroad. Where a textile component is cut to shape (but...

  14. A two-state stochastic model for nanoparticle self-assembly: theory, computer simulations and applications

    NASA Astrophysics Data System (ADS)

    Schwen, E. M.; Mazilu, I.; Mazilu, D. A.

    2015-03-01

    We introduce a stochastic cooperative model for particle deposition and evaporation relevant to ionic self-assembly of nanoparticles with applications in surface fabrication and nanomedicine, and present a method for mapping our model onto the Ising model. The mapping process allows us to use the established results for the Ising model to describe the steady-state properties of our system. After completing the mapping process, we investigate the time dependence of particle density using the mean field approximation. We complement this theoretical analysis with Monte Carlo simulations that support our model. These techniques, which can be used separately or in combination, are useful as pedagogical tools because they are tractable mathematically and they apply equally well to many other physical systems with nearest-neighbour interactions including voter and epidemic models.

  15. Preformed Soluble Chemoreceptor Trimers That Mimic Cellular Assembly States and Activate CheA Autophosphorylation.

    PubMed

    Greenswag, Anna R; Li, Xiaoxiao; Borbat, Peter P; Samanta, Dipanjan; Watts, Kylie J; Freed, Jack H; Crane, Brian R

    2015-06-01

    Bacterial chemoreceptors associate with the histidine kinase CheA and coupling protein CheW to form extended membrane arrays that receive and transduce environmental signals. A receptor trimers-of-dimers resides at each vertex of the hexagonal protein lattice. CheA is fully activated and regulated when it is integrated into the receptor assembly. To mimic these states in solution, we have engineered chemoreceptor cytoplasmic kinase-control modules (KCMs) based on the Escherichia coli aspartate receptor Tar that are covalently fused and trimerized by a foldon domain (TarFO). Small-angle X-ray scattering, multi-angle light scattering, and pulsed-dipolar electron spin resonance spectroscopy of spin-labeled proteins indicate that the TarFO modules assemble into homogeneous trimers wherein the protein interaction regions closely associate at the end opposite to the foldon domains. The TarFO variants greatly increase the saturation levels of phosphorylated CheA (CheA-P), indicating that the association with a trimer of receptor dimers changes the fraction of active kinase. However, the rate constants for CheA-P formation with the Tar variants are low compared to those for autophosphorylation by free CheA, and net phosphotransfer from CheA to CheY does not increase commensurately with CheA autophosphorylation. Thus, the Tar variants facilitate slow conversion to an active form of CheA that then undergoes stable autophosphorylation and is capable of subsequent phosphotransfer to CheY. Free CheA is largely incapable of phosphorylation but contains a small active fraction. Addition of TarFO to CheA promotes a planar conformation of the regulatory domains consistent with array models for the assembly state of the ternary complex and different from that observed with a single inhibitory receptor. Introduction of TarFO into E. coli cells activates endogenous CheA to produce increased clockwise flagellar rotation, with the effects increasing in the presence of the chemotaxis methylation system (CheB/CheR). Overall, the TarFO modules demonstrate that trimerized signaling tips self-associate, bind CheA and CheW, and facilitate conversion of CheA to an active conformation. PMID:25967982

  16. Diverging neural pathways assemble a behavioural state from separable features in anxiety.

    PubMed

    Kim, Sung-Yon; Adhikari, Avishek; Lee, Soo Yeun; Marshel, James H; Kim, Christina K; Mallory, Caitlin S; Lo, Maisie; Pak, Sally; Mattis, Joanna; Lim, Byung Kook; Malenka, Robert C; Warden, Melissa R; Neve, Rachael; Tye, Kay M; Deisseroth, Karl

    2013-04-11

    Behavioural states in mammals, such as the anxious state, are characterized by several features that are coordinately regulated by diverse nervous system outputs, ranging from behavioural choice patterns to changes in physiology (in anxiety, exemplified respectively by risk-avoidance and respiratory rate alterations). Here we investigate if and how defined neural projections arising from a single coordinating brain region in mice could mediate diverse features of anxiety. Integrating behavioural assays, in vivo and in vitro electrophysiology, respiratory physiology and optogenetics, we identify a surprising new role for the bed nucleus of the stria terminalis (BNST) in the coordinated modulation of diverse anxiety features. First, two BNST subregions were unexpectedly found to exert opposite effects on the anxious state: oval BNST activity promoted several independent anxious state features, whereas anterodorsal BNST-associated activity exerted anxiolytic influence for the same features. Notably, we found that three distinct anterodorsal BNST efferent projections-to the lateral hypothalamus, parabrachial nucleus and ventral tegmental area-each implemented an independent feature of anxiolysis: reduced risk-avoidance, reduced respiratory rate, and increased positive valence, respectively. Furthermore, selective inhibition of corresponding circuit elements in freely moving mice showed opposing behavioural effects compared with excitation, and in vivo recordings during free behaviour showed native spiking patterns in anterodorsal BNST neurons that differentiated safe and anxiogenic environments. These results demonstrate that distinct BNST subregions exert opposite effects in modulating anxiety, establish separable anxiolytic roles for different anterodorsal BNST projections, and illustrate circuit mechanisms underlying selection of features for the assembly of the anxious state. PMID:23515158

  17. Layer-by-layer assembly of polyelectrolytes into ionic current rectifying solid-state nanopores: insights from theory and experiment.

    PubMed

    Ali, Mubarak; Yameen, Basit; Cervera, Javier; Ramírez, Patricio; Neumann, Reinhard; Ensinger, Wolfgang; Knoll, Wolfgang; Azzaroni, Omar

    2010-06-23

    Molecular design of ionic current rectifiers created on the basis of single conical nanopores is receiving increasing attention by the scientific community. Part of the appeal of this topic relies on the interest in sensors and fluidic nanoactuators based on the transport of ions and molecules through nanopore architectures that can readily be integrated into functional systems. The chemical modification of the pore walls controls not only the diameter of these nanoarchitectures but also their selectivity and transport properties. In order to confer selectivity to solid-state nanopores, it is necessary to develop and explore new methods for functionalizing the pore walls. Hence, the creation of functional nanopores capable of acting as selective ion channels or smart nanofluidic sensors depends critically on our ability to assemble and build up molecular architectures in a predictable manner within confined geometries with dimensions comparable to the size of the building blocks themselves. In this context, layer-by-layer deposition of polyelectrolytes offers a straightforward process for creating nanoscopic supramolecular assemblies displaying a wide variety of functional features. In this work, we describe for the first time the integration of layer-by-layer polyelectrolyte assemblies into single conical nanopores in order to study and explore the functional features arising from the creation of charged supramolecular assemblies within the constrained geometry of the nanofluidic device. To address this challenging topic, we used a combined experimental and theoretical approach to elucidate and quantify the electrostatic changes taking place inside the nanopore during the supramolecular assembly process. The multilayered films were built up through consecutive layer-by-layer adsorption of poly(allylamine hydrochloride) (PAH) and poly(styrenesulfonate) (PSS) on the pore surface. Our results show that the charge transport properties of single conical nanopores functionalized with PAH/PSS assemblies are highly dependent on the number of layers assembled on the pore wall. In contrast to what happens with PAH/PSS films deposited on planar surfaces (quantitative charge reversal), the surface charge of the pore walls decreases dramatically with the number of PAH/PSS layers assembled into the nanopore. This behavior was attributed to the nanoconfinement-induced structural reorganization of the polyelectrolyte layers, leading to the efficient formation of ion pairs and promoting a marked decrease in the net fixed charges on the nanopore walls. We consider that these results are of paramount relevance for the modification of nanopores, nanopipets, and nanoelectrodes using charged supramolecular assemblies, as well as of importance in "soft nanotechnology" provided that structural complexity, induced by nanoconfinement, can define the functional properties of self-assembled polymeric nanostructures. PMID:20518503

  18. Successive Stages of Amyloid-? Self-Assembly Characterized by Solid-State Nuclear Magnetic Resonance with Dynamic Nuclear Polarization.

    PubMed

    Potapov, Alexey; Yau, Wai-Ming; Ghirlando, Rodolfo; Thurber, Kent R; Tycko, Robert

    2015-07-01

    Self-assembly of amyloid-? (A?) peptides in human brain tissue leads to neurodegeneration in Alzheimer's disease (AD). Amyloid fibrils, whose structures have been extensively characterized by solid state nuclear magnetic resonance (ssNMR) and other methods, are the thermodynamic end point of A? self-assembly. Oligomeric and protofibrillar assemblies, whose structures are less well-understood, are also observed as intermediates in the assembly process in vitro and have been implicated as important neurotoxic species in AD. We report experiments in which the structural evolution of 40-residue A? (A?40) is monitored by ssNMR measurements on frozen solutions prepared at four successive stages of the self-assembly process. Measurements on transient intermediates are enabled by ssNMR signal enhancements from dynamic nuclear polarization (DNP) at temperatures below 30 K. DNP-enhanced ssNMR data reveal a monotonic increase in conformational order from an initial state comprised primarily of monomers and small oligomers in solution at high pH, to larger oligomers near neutral pH, to metastable protofibrils, and finally to fibrils. Surprisingly, the predominant molecular conformation, indicated by (13)C NMR chemical shifts and by side chain contacts between F19 and L34 residues, is qualitatively similar at all stages. However, the in-register parallel ?-sheet supramolecular structure, indicated by intermolecular (13)C spin polarization transfers, does not develop before the fibril stage. This work represents the first application of DNP-enhanced ssNMR to the characterization of peptide or protein self-assembly intermediates. PMID:26068174

  19. Tomato Fruit Polygalacturonase Isozyme 1 (Characterization of the [beta] Subunit and Its State of Assembly in Vivo).

    PubMed Central

    Moore, T.; Bennett, A. B.

    1994-01-01

    Polygalacturonase isozyme 1 (PG1) is a heterodimer comprising a catalytic and noncatalytic or [beta] subunit, whereas polygalacturonase isozyme 2 (PG2) comprises only the catalytic subunit. To assess the state of assembly of PG1 in vivo, both subunits were purified to homogeneity and used to study assembly of the heterodimer. PG1 could be reconstituted in vitro from purified [beta] subunit and purified PG2 under a wide range of salt and pH conditions, and PG1 reconstituted in vitro was indistinguishable from PG1 isolated from tomato (Lycopersicon esculentum) fruit. Specific antibodies indicated that the [beta] subunit was present in fruit of all developmental stages, but absent in vegetative tissue. The state of assembly of PG1 in vivo was tested based on the differential thermal stability of PG1 and PG2 by heating segments of ripe fruit pericarp tissue. Temperatures well below those required to inactivate PG1 in vitro caused the loss of activity of both PG1 and PG2, suggesting that only heat-labile PG2 is present in vivo. In addition, when extracts of ripe fruit were rigorously maintained and analyzed at 4[deg]C, PG1 was absent or barely detectable. These results are consistent with the hypothesis that PG1 can assemble spontaneously and is essentially absent in intact tomato fruit but forms artifactually from PG2 and the [beta] subunit during the extraction of tomato fruit tissue when low temperatures are not rigorously maintained. PMID:12232422

  20. Millimeter Thin and Rubber-Like Solid-State Lighting Modules Fabricated Using Roll-to-Roll Fluidic Self-Assembly and Lamination.

    PubMed

    Park, Se-Chul; Biswas, Shantonu; Fang, Jun; Mozafari, Mahsa; Stauden, Thomas; Jacobs, Heiko O

    2015-06-01

    A millimeter thin rubber-like solid-state lighting module is reported. The fabrication of the lighting module incorporates assembly and electrical connection of light-emitting diodes (LEDs). The assembly is achieved using a roll-to-roll fluidic self-assembly. The LEDs are sandwiched in-between a stretchable top and bottom electrode to relieve the mechanical stress. The top contact is realized using a lamination technique that eliminates wire-bonding. PMID:25966304

  1. From pure superparamagnetic regime to glass collective state of magnetic moments in ?-Fe2O3 nanoparticle assemblies

    NASA Astrophysics Data System (ADS)

    Dormann, J. L.; Cherkaoui, R.; Spinu, L.; Noguès, M.; Lucari, F.; D'Orazio, F.; Fiorani, D.; Garcia, A.; Tronc, E.; Jolivet, J. P.

    1998-08-01

    Studies of the frequency dependence of the temperature of the AC susceptibility peak, of the thermal variation of the nonlinear DC susceptibility, and of ageing effects on the magnetization relaxation in ?-Fe2O3 4.7 nm nanoparticle assemblies with interparticle interactions of varying strength, give evidence of three magnetic regimes: pure superparamagnetic, superparamagnetic modified by the interactions, and collective. The properties of the latter regime, called glass collective state, are close to those of a canonical spin glass.

  2. An Amyloid Organelle: Solid State NMR Evidence for Cross-Beta Assembly of Gas Vesicles

    E-print Network

    Bayro, Marvin J.

    Functional amyloids have been identified in a wide range of organisms, taking on a variety of biological roles and being controlled by remarkable mechanisms of directed assembly. Here, we report that amyloid fibrils ...

  3. Synthesis and solution state self-assembly of linear-dendritic block copolymers

    E-print Network

    Stokes, Kristoffer Keith

    2007-01-01

    Linear-dendritic block copolymers consisting of a poly(styrene) linear block and poly(amidoamine) dendrimer block were synthesized and examined for their ability to self-assemble in both aqueous environments and organic/aqueous ...

  4. Exclusive Hydrophobic Self-Assembly of Adaptive Solid-State Networks of Octasubstituted 9,9'-Spirobifluorenes.

    PubMed

    Pop, Lidia; Dumitru, Florina; H?dade, Niculina D; Legrand, Yves-Marie; van der Lee, Arie; Barboiu, Mihail; Grosu, Ion

    2015-07-17

    An easy and powerful access to 3,3',6,6'-tetrasubstituted 9,9'-spirobifluorene derivatives with tetrahedral orientation of the peripheral groups (i.e., -I, -CN, -NO2, -CH?O, -COOH, -C?CH, -4-Py) was developed. The NMR and HRMS results are in agreement with the proposed formula and the solid-state molecular structures obtained by single-crystal X-ray diffraction. They form molecular solids self-assembled via exclusive hydrophobic interactions. Solid-state selection and adaptation can be obtained on the basis of variable compact packing of functional groups present on the 9,9'-spirobifluorene backbone. PMID:26151542

  5. Seal assembly

    DOEpatents

    Johnson, Roger Neal (Hagaman, NY); Longfritz, William David (Fonda, NY)

    2001-01-01

    A seal assembly that seals a gap formed by a groove comprises a seal body, a biasing element, and a connection that connects the seal body to the biasing element to form the seal assembly. The seal assembly further comprises a concave-shaped center section and convex-shaped contact portions at each end of the seal body. The biasing element is formed from an elastic material and comprises a convex-shaped center section and concave-shaped biasing zones that are opposed to the convex-shaped contact portions. The biasing element is adapted to be compressed to change a width of the seal assembly from a first width to a second width that is smaller than the first width. In the compressed state, the seal assembly can be disposed in the groove. After release of the compressing force, the seal assembly expands. The contact portions will move toward a surface of the groove and the biasing zones will move into contact with another surface of the groove. The biasing zones will bias the contact portions of the seal body against the surface of the groove.

  6. Operational planning of electronic assembly systems in the presence of state dependent setup and processing times

    E-print Network

    Subramanian, Gowri Shankar

    1994-01-01

    Optimization of the machine and line level issues in an electronic assembly system (EAS) is imperative for the efficient use of resources in the system. This research considers the joint optimization of machine and line level issues in an EAS. Joint...

  7. Ultrafast Excited State Dynamics and Structures in Self-Assembled Molecular Aggregates of Helicenocyanines

    Microsoft Academic Search

    George B. Shaw; Thanasat Sooksimuang; Braja K. Mandal; Peter Zapol; Paul C. Redfern; David M. Tiede; Larry A. Curtiss; Lin X. Chen

    2003-01-01

    A series of novel phthalocyanines Â- with and without Zn metallated cores Â- that have helicene groups substituted on the periphery were investigated. These compounds exhibit a tendency to self-assemble into molecular aggregates (likely dimers) even at very low concentrations (10-7 M) in common organic solvents. This aggregation dramatically alters their optical properties compared to the monomer. New and\\/or reshaped

  8. Measurement of discrete electronic states in a gold nanoparticle using tunnel junctions formed from self-assembled monolayers

    NASA Astrophysics Data System (ADS)

    Petta, J. R.; Guéron, S.; Salinas, D. G.; Ralph, D. C.; Murray, C. B.

    2000-03-01

    We use electron tunneling to measure discrete electronic energy levels in individual gold nanoparticles. The devices are constructed in a nano-constriction geometry using self-assembled monolayers of either 1,6-Hexanedithiol or 3-Mercaptopropionic acid as the tunnel barriers. These barriers are sufficiently stable to allow the observation of well-resolved electronic states at mK temperatures. As a function of applied magnetic field, the discrete states undergo spin-Zeeman splitting, with g-factors in the range 0.3-0.9. These values are consistent with measurements of Davidovi? and Tinkham(D. Davidovi? and M. Tinkham, Phys. Rev. Lett. 83), 1644 (1999), using gold nanoparticles with aluminum oxide tunnel barriers. Differences between devices fabricated with 1,6-Hexanedithiol and 3-Mercaptopropionic acid will be explored.

  9. Assembly states of FliM and FliG within the flagellar switch complex.

    PubMed

    Sircar, Ria; Borbat, Peter P; Lynch, Michael J; Bhatnagar, Jaya; Beyersdorf, Matthew S; Halkides, Christopher J; Freed, Jack H; Crane, Brian R

    2015-02-27

    At the base of the bacterial flagella, a cytoplasmic rotor (the C-ring) generates torque and reverses rotation sense in response to stimuli. The bulk of the C-ring forms from many copies of the proteins FliG, FliM, and FliN, which together constitute the switch complex. To help resolve outstanding issues regarding C-ring architecture, we have investigated interactions between FliM and FliG from Thermotoga maritima with X-ray crystallography and pulsed dipolar ESR spectroscopy (PDS). A new crystal structure of an 11-unit FliG:FliM complex produces a large arc with a curvature consistent with the dimensions of the C-ring. Previously determined structures along with this new structure provided a basis to test switch complex assembly models. PDS combined with mutational studies and targeted cross-linking reveal that FliM and FliG interact through their middle domains to form both parallel and antiparallel arrangements in solution. Residue substitutions at predicted interfaces disrupt higher-order complexes that are primarily mediated by contacts between the C-terminal domain of FliG and the middle domain of a neighboring FliG molecule. Spin separations among multi-labeled components fit a self-consistent model that agree well with electron microscopy images of the C-ring. An activated form of the response regulator CheY destabilizes the parallel arrangement of FliM molecules to perturb FliG alignment in a process that may reflect the onset of rotation switching. These data suggest a model of C-ring assembly in which intermolecular contacts among FliG domains provide a template for FliM assembly and cooperative transitions. PMID:25536293

  10. Modeling capsid kinetics assembly from the steady state distribution of multi-sizes aggregates

    NASA Astrophysics Data System (ADS)

    Hozé, Nathanaël; Holcman, David

    2014-01-01

    The kinetics of aggregation for particles of various sizes depends on their diffusive arrival and fusion at a specific nucleation site. We present here a mean-field approximation and a stochastic jump model for aggregates at equilibrium. This approach is an alternative to the classical Smoluchowski equations that do not have a close form and are not solvable in general. We analyze these mean-field equations and obtain the kinetics of a cluster formation. Our approach provides a simplified theoretical framework to study the kinetics of viral capsid formation, such as HIV from the self-assembly of the structural proteins Gag.

  11. Papillomavirus E1 helicase assembly maintains an asymmetric state in the absence of DNA and nucleotide cofactors.

    PubMed

    Sanders, Cyril M; Kovalevskiy, Oleg V; Sizov, Dmytro; Lebedev, Andrey A; Isupov, Michail N; Antson, Alfred A

    2007-01-01

    Concerted, stochastic and sequential mechanisms of action have been proposed for different hexameric AAA+ molecular motors. Here we report the crystal structure of the E1 helicase from bovine papillomavirus, where asymmetric assembly is for the first time observed in the absence of nucleotide cofactors and DNA. Surprisingly, the ATP-binding sites adopt specific conformations linked to positional changes in the DNA-binding hairpins, which follow a wave-like trajectory, as observed previously in the E1/DNA/ADP complex. The protein's assembly thus maintains such an asymmetric state in the absence of DNA and nucleotide cofactors, allowing consideration of the E1 helicase action as the propagation of a conformational wave around the protein ring. The data imply that the wave's propagation within the AAA+ domains is not necessarily coupled with a strictly sequential hydrolysis of ATP. Since a single ATP hydrolysis event would affect the whole hexamer, such events may simply serve to rectify the direction of the wave's motion. PMID:17881379

  12. Amplification of light collection in solid-state dye-sensitized solar cells via the antenna effect through supramolecular assembly.

    PubMed

    Louahem M'Sabah, Bilel; Boucharef, Mourad; Warnan, Julien; Pellegrin, Yann; Blart, Errol; Lucas, Bruno; Odobel, Fabrice; Bouclé, Johann

    2015-04-21

    This study demonstrates that the concept of molecular antenna is a relevant strategy to improve the power conversion efficiency of solid-state dye-sensitized solar cells by extending their spectral sensitivity over a broad region of the solar spectrum. In this work, we have associated a BODIPY antenna to a bi-chromophoric sensitizer made of a squaraine unit linked to a zinc porphyrin by axial ligation onto the zinc. Using steady-state and transient photoluminescence spectroscopy, we demonstrate that efficient energy transfers occur from the antenna to the dyad, extending its visible photosensitivity. We also show that direct electron injection from the antenna to TiO2 is possible. A drastic improvement in the device performance by a factor of three is observed under illumination using the spiro-OMeTAD molecular glass as the solid-state electrolyte, leading to a panchromatic response of the device. The influence of the solid-state hole transporter on the supramolecular assembly is also discussed. PMID:25776534

  13. Origin Remodeling and Opening in Bacteria Rely on Distinct Assembly States of the DnaA Initiator

    PubMed Central

    Duderstadt, Karl E.; Mott, Melissa L.; Crisona, Nancy J.; Chuang, Kevin; Yang, Haw; Berger, James M.

    2010-01-01

    The initiation of DNA replication requires the melting of chromosomal origins to provide a template for replisomal polymerases. In bacteria, the DnaA initiator plays a key role in this process, forming a large nucleoprotein complex that opens DNA through a complex and poorly understood mechanism. Using structure-guided mutagenesis, biochemical, and genetic approaches, we establish an unexpected link between the duplex DNA-binding domain of DnaA and the ability of the protein to both self-assemble and engage single-stranded DNA in an ATP-dependent manner. Intersubunit cross-talk between this domain and the DnaA ATPase region regulates this link and is required for both origin unwinding in vitro and initiator function in vivo. These findings indicate that DnaA utilizes at least two different oligomeric conformations for engaging single- and double-stranded DNA, and that these states play distinct roles in controlling the progression of initiation. PMID:20595381

  14. Millisecond switching in solid state electrochromic polymer devices fabricated from ionic self-assembled multilayers

    E-print Network

    Heflin, Randy

    Millisecond switching in solid state electrochromic polymer devices fabricated from ionic self The electrochromic switching times of solid state conducting polymer devices fabricated by the ionic self shown to decrease with the active area of the electrochromic device suggesting that even faster

  15. Disulfide-Bond Scanning Reveals Assembly State and ?-Strand Tilt Angle of PFO ?-Barrel

    PubMed Central

    Sato, Takehiro K.; Tweten, Rodney K.; Johnson, Arthur E.

    2013-01-01

    Perfringolysin O (PFO), a bacterial cholesterol-dependent cytolysin, binds to a mammalian cell membrane, oligomerizes into a circular prepore complex (PPC), and forms a 250-Å transmembrane ?-barrel pore in the cell membrane. Each PFO monomer has two sets of 3 short ?-helices that unfold and ultimately refold into two transmembrane ?-hairpin (TMH) components of the membrane-embedded ?-barrel. Inter-strand disulfide bond scanning revealed that ?-strands in a fully assembled PFO?-barrel were strictly aligned and tilted at 20 ° to the membrane perpendicular. In contrast, in a low temperature-trapped PPC intermediate, the TMHs were unfolded and had sufficient freedom of motion to interact transiently with each other; yet the TMHs were not aligned or stably hydrogen-bonded. The PFO PPC-to-pore transition therefore converts TMHs in a dynamic folding intermediate far above the membrane into transmembrane ?-hairpins that are hydrogen bonded to those of adjacent subunits in the bilayer-embedded ?-barrel. PMID:23563525

  16. Pseudonegative thermal expansion and the state of water in graphene oxide layered assemblies.

    PubMed

    Zhu, Jian; Andres, Christine M; Xu, Jiadi; Ramamoorthy, Ayyalusamy; Tsotsis, Thomas; Kotov, Nicholas A

    2012-09-25

    Unraveling the complex interplay between thermal properties and hydration is a part of understanding the fundamental properties of many soft materials and very essential for many applications. Here we show that graphene oxide (GO) demonstrates a highly negative thermal expansion (NTE) coefficient owing to unique thermohydration processes related with fast transport of water between the GO sheets, the amphiphilic nature of nanochannels, and close-to-zero intrinsic thermal expansion of GO. The humidity-dependent NTE of GO layered assemblies, or "pseudonegative thermal expansion" (PNTE), differs from that of other hygroscopic materials due to its relatively fast and highly reversible expansion/contraction cycles and occurrence at low humidity levels while bearing similarities to classic NTE. Thermal expansion of polyvinyl alcohol/GO composites is easily tunable with additional intricacy of thermohydration effects. PNTE combined with isotropy, nontoxicity, and mechanical robustness is an asset for applications of actuators, sensors, MEMS devices, and memory materials and crucial for developing methods of thermal/photopatterning of GO devices. PMID:22861527

  17. Governance within the World Health Assembly: a 13-year analysis of WHO Member States' contribution to global health governance.

    PubMed

    van der Rijt, Tess; Pang Pangestu, Tikki

    2015-03-01

    There is a widespread perception that developed countries in the Western world dictate the shaping and governance of global health. While there are many bodies that engage in global health governance, the World Health Organisation (WHO) is the only entity whereby 194 countries are invited to congregate together and engage in global health governance on an equal playing field. This paper examines the diversity of governance within the World Health Assembly (WHA), the supreme decision-making body of the WHO. It explores the degree and balance of policy influence between high, middle and low-income countries and the relevance of the WHO as a platform to exercise global governance. It finds that governance within the WHA is indeed diverse: relative to the number of Member States within the regions, all regions are well represented. While developed countries still dominate WHA governance, Western world countries do not overshadow decision-making, but rather there is evidence of strong engagement from the emerging economies. It is apparent that the WHO is still a relevant platform whereby all Member States can and do participate in the shaping of global health governance. PMID:25596958

  18. Neurodegeneration Induced by ,&Amyloid Peptides in vi&o: The Role of Peptide Assembly State

    Microsoft Academic Search

    Christian J. Pike; Debra Burdick; Andrea J. Walencewicz; Charles G. Glabe; Carl W. Cotman

    1993-01-01

    The progressive neurodegeneration of Alzheimer's disease has been hypothesized to be mediated, at least in part, by D-amyloid protein. A relationship between the aggregation state of B-amyloid protein and its ability to promote degen- eration in vitro has been previously suggested. To evaluate this hypothesis and to define a structure-activity relation- ship for \\/3-amyloid, aggregation properties of an overlapping series

  19. Electronic states and tunneling times in coupled self-assembled quantum dots

    NASA Astrophysics Data System (ADS)

    López-Bolaños, R.; Cocoletzi, G. H.; Ulloa, S. E.

    2001-11-01

    Electron energy levels in single dots, and energy splitting and tunneling times in stacked quantum dots are calculated as functions of structure parameters. An effective mass approach is used to solve the Schrödinger equation for cylindrical dots with finite confinement potentials. Strong confinement due to small sizes produces quantized energy levels in single dots and strong interactions of the wavefunctions with adjacent dots. This electronic coupling induces significant energy splittings and short tunneling times for characteristic structures used in experiments. This coupling may even yield coherent artificial molecular states with different optical properties.

  20. Temperature dependence of photoluminescence dynamics of self-assembled monolayers of CdSe quantum dots: the influence of the bound-exciton state.

    PubMed

    Kim, DaeGwi; Yokota, Hiroki; Shimura, Kunio; Nakayama, Masaaki

    2013-12-28

    We have investigated the temperature dependence of photoluminescence (PL) dynamics of self-assembled monolayers (SAMs) of CdSe quantum dots (QDs). The PL decay profiles become slower with an increase in temperature up to 160 K, contrary to an ordinary behavior due to thermal quenching. Such anomalous temperature dependence of the PL-decay profile is explained using a four-state model which introduces a bound-exciton state into a conventional three-state model consisting of a ground state and two excited states: a lower-lying dark-exciton state and a higher-lying bright-exciton state. Furthermore, it is proposed that the radiative decay time of QDs is strongly influenced by the presence or absence of the bound-exciton state. PMID:24220232

  1. State-of-the-art silicon carbide optical telescope assembly for the JMAPS mission

    NASA Astrophysics Data System (ADS)

    Catropa, Dan; Azad, Farsh

    2013-09-01

    L-3 Communications IOS-SSG (L-3 SSG) has recently completed development of an ultra low wavefront error and highly stable Silicon Carbide (SiC) optical payload for the Joint Milli-Arcsecond Pathfinder Survey (JMAPS) mission. Selection of SiC as the opto-mechanical material was driven by the JMAPS requirements for extremely low residual optical aberrations and distortion, and state-of-the-art temporal and thermal stability. JMAPS utilizes a passively athermalized design, combining SiC optics with aggressively lightweighted SiC metering structures. The resulting hardware has been optically tested over temperature, demonstrating an exceptionally low and stable system level wavefront error. This exceptional performance, combined with the aggressively lightweighted sinterbonded SiC structures developed result in an instrument which represents the state-of-the-art from the perspective of optical performance and structural efficiency. We will provide an overview of the system, with emphasis on the SiC opto-mechanics, and system level test results.

  2. Nucleosome assembly and epigenetic inheritance

    Microsoft Academic Search

    Mo Xu; Bing Zhu

    2010-01-01

    In eukaryotic cells, histones are packaged into octameric core particles with DNA wrapping around to form nucleosomes, which\\u000a are the basic units of chromatin (Kornberg and Thomas, 1974). Multicellular organisms utilise chromatin marks to translate\\u000a one single genome into hundreds of epigenomes for their corresponding cell types. Inheritance of epigenetic status is critical\\u000a for the maintenance of gene expression profile

  3. EXTENSION ADMINISTRATION AND STATE LEGISLATIVE PROCESS--A CASE STUDY OF THE 71ST MISSOURI GENERAL ASSEMBLY.

    ERIC Educational Resources Information Center

    KYD, STIRLING

    TO GAIN UNDERSTANDING OF MISSOURI'S LEGISLATIVE PROCESS AND AID ADMINISTRATORS OF THE EXTENSION DIVISION, THE AUTHOR INVESTIGATED THE 71ST GENERAL ASSEMBLY. HE READ PUBLICATIONS, INTERVIEWED LOBBYISTS, AND CONDUCTED OPEN ENDED DEPTH INTERVIEWS WITH LEGISLATORS SELECTED TO COMPRISE THE LEADERSHIP OF THE ASSEMBLY. HIS DISSERTATION PRESENTS THE…

  4. Assembly State of Proteasome Activator 28 in an Aqueous Solution as Studied by Small-Angle Neutron Scattering

    NASA Astrophysics Data System (ADS)

    Sugiyama, Masaaki; Kurimoto, Eiji; Morimoto, Yukio; Sahashi, Hiroki; Sakata, Eri; Hamada, Kei; Itoh, Keiji; Mori, Kazuhiro; Fukunaga, Toshiharu; Minami, Yasufumi; Kato, Koichi

    2009-12-01

    The characterization of quaternary structures of proteins in solution remains challenging, especially for those undergoing dynamic changes. Small-angle neutron scattering (SANS) is a potentially powerful method for addressing this issue with little perturbation resulting from irradiation damage. However, it is usually difficult to determine the three-dimensional (3D) structure of protein complexes at the atomic level on the basis of only SANS data. To cope with this difficulty, we developed a novel approach combining 3D homology modeling with SANS profile simulation, in which whole simulated SANS profiles were examined together with experimental SANS data. We herein demonstrate the feasibilty of our strategy using proteasome activator 28 (PA28) as a model system. PA28 is a hetero-oligomeric protein composed of homologous ?- and ?-subunits. Although the crystal structure of the homoheptameric ring of ?-subunits (PA28?7) has been reported, the physiologically relevant hetero-oligomeric structure remains to be elucidated. On the basis of the PA28?7 structure, we performed homology modeling to build hypothetical quaternary structures of the PA28 hetero-oligomer. By analyzing the SANS data of a PA28 mutant lacking a mobile loop in its ?-subunit, we successfully revealed that ?- and ?-subunits form heteroheptameric rings, about half of which are stacked back to back to form a double-ring structure. Thus, our SANS approach provides in-depth information on the assembly states of protein subunits in aqueous solutions.

  5. Self-Assembled Si(111) Surface States: 2D Dirac Material for THz Plasmonics.

    PubMed

    Wang, Z F; Liu, Feng

    2015-07-10

    Graphene, the first discovered 2D Dirac material, has had a profound impact on science and technology. In the last decade, we have witnessed huge advances in graphene related fundamental and applied research. Here, based on first-principles calculations, we propose a new 2D Dirac band on the Si(111) surface with 1/3 monolayer halogen coverage. The sp^{3} dangling bonds form a honeycomb superstructure on the Si(111) surface that results in an anisotropic Dirac band with a group velocity (?10^{6}??m/s) comparable to that in graphene. Most remarkably, the Si-based surface Dirac band can be used to excite a tunable THz plasmon through electron-hole doping. Our results demonstrate a new way to design Dirac states on a traditional semiconductor surface, so as to make them directly compatible with Si technology. We envision this new type of Dirac material to be generalized to other semiconductor surfaces with broad applications. PMID:26207493

  6. A ?-Hairpin Comprising the Nuclear Localization Sequence Sustains the Self-associated States of Nucleosome Assembly Protein 1

    Microsoft Academic Search

    Young-Jun Park; Steven J. McBryant; Karolin Luger

    2008-01-01

    The histone chaperone nucleosome assembly protein 1 (NAP1) is implicated in histone shuttling as well as nucleosome assembly and disassembly. Under physiological conditions, NAP1 dimers exist in a mixture of various high-molecular-weight oligomers whose size may be regulated by the cell cycle-dependent concentration of NAP1. Both the functional and structural significance of the observed oligomers are unknown. We have resolved

  7. Neural assembly computing.

    PubMed

    Ranhel, João

    2012-06-01

    Spiking neurons can realize several computational operations when firing cooperatively. This is a prevalent notion, although the mechanisms are not yet understood. A way by which neural assemblies compute is proposed in this paper. It is shown how neural coalitions represent things (and world states), memorize them, and control their hierarchical relations in order to perform algorithms. It is described how neural groups perform statistic logic functions as they form assemblies. Neural coalitions can reverberate, becoming bistable loops. Such bistable neural assemblies become short- or long-term memories that represent the event that triggers them. In addition, assemblies can branch and dismantle other neural groups generating new events that trigger other coalitions. Hence, such capabilities and the interaction among assemblies allow neural networks to create and control hierarchical cascades of causal activities, giving rise to parallel algorithms. Computing and algorithms are used here as in a nonstandard computation approach. In this sense, neural assembly computing (NAC) can be seen as a new class of spiking neural network machines. NAC can explain the following points: 1) how neuron groups represent things and states; 2) how they retain binary states in memories that do not require any plasticity mechanism; and 3) how branching, disbanding, and interaction among assemblies may result in algorithms and behavioral responses. Simulations were carried out and the results are in agreement with the hypothesis presented. A MATLAB code is available as a supplementary material. PMID:24806763

  8. Graduate Education. Report of the State Council of Higher Education to the Governor and the General Assembly of Virginia.

    ERIC Educational Resources Information Center

    Virginia State Council of Higher Education, Richmond.

    This report on graduate education, requested by the Virginia General Assembly, was developed by a task force that included graduate students, faculty, and administrators. The task force based its work on a previous report issued by an advisory committee of chief academic officers, a review of recent literature on graduate education, and their own…

  9. Joint assembly

    NASA Technical Reports Server (NTRS)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2010-01-01

    A joint assembly is provided which includes a drive assembly and a swivel mechanism. The drive assembly features a motor operatively associated with a plurality of drive shafts for driving auxiliary elements, and a plurality of swivel shafts for pivoting the drive assembly. The swivel mechanism engages the swivel shafts and has a fixable element that may be attached to a foundation. The swivel mechanism is adapted to cooperate with the swivel shafts to pivot the drive assembly with at least two degrees of freedom relative to the foundation. The joint assembly allows for all components to remain encased in a tight, compact, and sealed package, making it ideal for space, exploratory, and commercial applications.

  10. Engineering solid-state materials. Strategies for modeling and packing control of molecular assemblies into 3-D networks

    NASA Astrophysics Data System (ADS)

    Videnova-Adrabinska, V.; Etter, M. C.; Ward, M. D.

    1993-04-01

    The crystal structure and properties of a number of urea cocrystals are studied with regard to symmetry of the hydrogen-bonded molecular assemblies. The logical consequences of hydrogen bonding interactions are followed step-by-step. The problems of aggregate formation, nucleation, and crystal growth are also elucidated. Endeavor is made to envisage the 2-D and 3-D hydrogen bond network in a manageable way by exploiting graph set short hand. Strategies of how to control the symmetry of molecular packing are still to be elaborated. In our strategy, the programmed self-assembly has been based on the principle of molecular recognition of self- and hetero-complementary functional groups. However, the main focus for pre-organizational control has been put on the two-fold axis estimator of the urea molecule.

  11. Redox State of Pentraxin 3 as a Novel Biomarker for Resolution of Inflammation and Survival in Sepsis*

    PubMed Central

    Cuello, Friederike; Shankar-Hari, Manu; Mayr, Ursula; Yin, Xiaoke; Marshall, Melanie; Suna, Gonca; Willeit, Peter; Langley, Sarah R.; Jayawardhana, Tamani; Zeller, Tanja; Terblanche, Marius; Shah, Ajay M.; Mayr, Manuel

    2014-01-01

    In an endotoxaemic mouse model of sepsis, a tissue-based proteomics approach for biomarker discovery identified long pentraxin 3 (PTX3) as the lead candidate for inflamed myocardium. When the redox-sensitive oligomerization state of PTX3 was further investigated, PTX3 accumulated as an octamer as a result of disulfide-bond formation in heart, kidney, and lung—common organ dysfunctions seen in patients with sepsis. Oligomeric moieties of PTX3 were also detectable in circulation. The oligomerization state of PTX3 was quantified over the first 11 days in critically ill adult patients with sepsis. On admission day, there was no difference in the oligomerization state of PTX3 between survivors and non-survivors. From day 2 onward, the conversion of octameric to monomeric PTX3 was consistently associated with a greater survival after 28 days of follow-up. For example, by day 2 post-admission, octameric PTX3 was barely detectable in survivors, but it still constituted more than half of the total PTX3 in non-survivors (p < 0.001). Monomeric PTX3 was inversely associated with cardiac damage markers NT-proBNP and high-sensitivity troponin I and T. Relative to the conventional measurements of total PTX3 or NT-proBNP, the oligomerization of PTX3 was a superior predictor of disease outcome. PMID:24958171

  12. LptE binds to and alters the physical state of LPS to catalyze its assembly at the cell surface

    PubMed Central

    Maloj?i?, Goran; Andres, Dorothee; Grabowicz, Marcin; George, Alexander H.; Ruiz, Natividad; Silhavy, Thomas J.; Kahne, Daniel

    2014-01-01

    The assembly of lipopolysaccharide (LPS) on the surface of Gram-negative bacterial cells is essential for their viability and is achieved by the seven-protein LPS transport (Lpt) pathway. The outer membrane (OM) lipoprotein LptE and the ?-barrel membrane protein LptD form a complex that assembles LPS into the outer leaflet of the OM. We report a crystal structure of the Escherichia coli OM lipoprotein LptE at 2.34 Å. The structure reveals homology to eukaryotic LPS-binding proteins and allowed for the prediction of an LPS-binding site, which was confirmed by genetic and biophysical experiments. Specific point mutations at this site lead to defects in OM biogenesis. We show that wild-type LptE disrupts LPS–LPS interactions in vitro and that these mutations decrease the ability of LptE to disaggregate LPS. Transmission electron microscopic imaging shows that LptE can disrupt LPS aggregates even at substoichiometric concentrations. We propose a model in which LptE functions as an LPS transfer protein in the OM translocon by disaggregating LPS during transport to allow for its insertion into the OM. PMID:24938785

  13. 77 FR 31290 - Notice of Public Meeting of the Assembly of the Administrative Conference of the United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-25

    ...applicable to the public...appearing in this section...CONFERENCE OF THE UNITED STATES Notice of...Conference of the United States to consider...rules, (3) immigration removal adjudication, (4) the Paperwork...Comments'' in the...

  14. Assembly and antigenicity of the Neisseria gonorrhoeae pilus mapped with antibodies.

    PubMed Central

    Forest, K T; Bernstein, S L; Getzoff, E D; So, M; Tribbick, G; Geysen, H M; Deal, C D; Tainer, J A

    1996-01-01

    The relationship between the sequence of Neisseria gonorrhoeae pilin and its quaternary assembly into pilus fibers was studied with a set of site-directed antibody probes and by mapping the specificities of antipilus antisera with peptides. Buried and exposed peptides in assembled pili were identified by competitive immunoassays and immunoelectron microscopy with polyclonal antibodies raised against 11 peptides spanning the pilin sequence. Pili did not compete significantly with pilin subunits for binding to antibodies against residues 13 to 31 (13-31) and 18-36. Pilus fibers competed well with pilin protein subunits for binding to antibodies raised against peptides 37-56, 58-78, 110-120, 115-127, 122-139, and 140-159 and competed weakly for antibodies against residues 79-93 and 94-108. Antibodies to sequence-conserved residues 37-56 and to semiconserved residues 94-108 preferentially bound pilus ends as shown by immunoelectron microscopy. The exposure of pilus regions to the immune system was tested by peptide mapping of antiserum specificities against sets of overlapping peptides representing all possible hexameric or octameric peptides from the N. gonorrhoeae MS11 pilin sequence. The immunogenicity of exposed peptides incorporating semiconserved residues 49-56 and 121-126 was revealed by strong, consistent antigenic reactivity to these regions measured in antipilus sera from rabbits, mice, and human and in sera from human volunteers with gonorrhea. The conservation and variation of antigenic responses among these three species clarify the relevance of immunological studies of other species to the human immune response against pathogens. Overall, our results explain the extreme conservation of the entire N-terminal one-third of the pilin protein by its dominant role in pilus assembly: hydrophobic residues 1-36 are implicated in buried lateral contacts, and polar residues 37-56 are implicated in longitudinal contacts within the pilus fiber. PMID:8550220

  15. Fabrication and transfer assembly of microscale, solid-state light emitting diodes and solar cells for transparent and flexible electronics applications

    NASA Astrophysics Data System (ADS)

    Brueckner, Eric P.

    Efficiency metrics for some solid-state electronic materials systems have progressed to the point where theoretical limits are being approached. Gallium nitride-based lightemitting diodes and silicon solar cells, for example, have achieved such extraordinarily high performance metrics that only incremental improvements upon them are expected in the next decade of intense research. This pseudo-plateau in performance development means concentrated effort can now be placed on strategic implementation of these materials into platforms that fill a growing demand for high-performance consumer products. Such products have traditionally relied upon large-scale materials, but possibilities now exist for manipulating micro-scale, wafer-based devices in ways that promote improvements in areas of electrical current spreading, light absorption and extraction, and thermal management. To this end, my research has focused on routes to fabricating and assembling solid-state light-emitting diodes and solar cells of indium gallium nitride and single-crystalline silicon, respectively, in configurations which optimize characteristics of their performance. Specifically, I have worked, in collaboration with others, to achieve a processing strategy that creates dense arrays of indium gallium nitride light-emitting diodes on a silicon wafer of (111) orientation and assemble them onto transparent and flexible substrates. This work produced novel form factors for solid-state lighting where small, light-emitting devices were spatially distributed and integrated with color-converting phosphors in ways that controllably tuned their chromaticity. We also demonstrated that incredible passive heat dissipation with these micro-scale elements stemming naturally from their small size and integration with metal films serving dually as an electrically interconnecting medium. The cell design and etching strategies used were then transferred to a single-crystalline silicon system where small, ribbon-like solar cells were fabricated. This work improved upon previous studies creating similar devices by increasing critical solar cell performance metrics. The developed solar cell structure utilizes a highly robust manufacturing layer of thermally-grown silicon dioxide which naturally doubles as an anti-reflection and passivation layer. Other improvements to previous performance metrics comes from optimized cell assembly onto structures that recycle and redistribute incident irradiation.

  16. Quasi-1D States Confined in a Self-Assembled Organic Super-Lattice of TTF-TCNQ on Ag(111)

    NASA Astrophysics Data System (ADS)

    Jeon, Seokmin; Ganesh, Panchapakesan; Sumpter, Bobby; Cerdá, Jorge Iribas; Maksymovych, Petro; CNMS Team; ICMM-CSIC Team

    2015-03-01

    Organic charge transfer complexes (CTC) have drawn much attention due to their potential applications to conducting or semiconducting organic thin films and contacts in devices. TTF-TCNQ is a historic organic CTC with one of the highest conductivity values among numerous organic conductors. As a two-component molecular material, TTF-TCNQ in a low-dimension form on a surface naturally creates monolayer super-lattices with corrugated electrostatic potential and adsorbate-induced strain. Generally this will lead to strong confinement of the surface states, although the detailed response of the surface electronic structure remains to be understood. We investigated TTF-TCNQ monolayer films grown on Ag(111), Au(111) and Ag(100) surfaces using STM/STS at 4.3 K. Confinement of sp-derived surface states was indeed ubiquitous, including spontaneous formation of quantum dots and quasi-1D bands. The small periodicity of the lattice caused a complete depopulation of the surface states, with up to 1 eV upshift of the band minimum - much stronger effect than normally observed in assemblies. This also allows us to infer the height of the confining potential using 1D Kronig-Penney model and critically assess the long-standing problem of molecule-surface charge transfer. A portion of this research was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility.

  17. Latch assembly

    DOEpatents

    Frederickson, J.R.; Harper, W.H.; Perez, R.

    1984-08-17

    A latch assembly for releasably securing an article in the form of a canister within a container housing. The assembly includes a cam pivotally mounted on the housing wall and biased into the housing interior. The cam is urged into a disabled position by the canister as it enters the housing and a latch release plate maintains the cam disabled when the canister is properly seated in the housing. Upon displacement of the release plate, the cam snaps into latching engagement against the canister for securing the same within the housing. 2 figs.

  18. Valve assembly

    SciTech Connect

    Marshala, D.L.

    1986-12-16

    This patent describes a subsurface pump actuated by a reciprocatable sucker rod for producing well liquids from a subsurface reservoir involving a piston adapted to reciprocate within a cylinder immersed in the reservoir, the piston being provided with a traveling valve. The improvement described here comprises valve means connected to the sucker tod for lifting a body of fluid during upstrokes of the sucker rod, the valve means comprising: a barrel assembly having an internal bore and comprising: a lower barrel member; and an upper barrel assembly connected to the lower barrel and having a beveled seating surface with at least one fluid port therethrough.

  19. Solid-State Densification of Spun-Cast Self-Assembled Monolayers for Use in Ultra-Thin Hybrid Dielectrics.

    PubMed

    Hutchins, Daniel O; Acton, Orb; Weidner, Tobias; Cernetic, Nathan; Baio, Joe E; Castner, David G; Ma, Hong; Jen, Alex K-Y

    2012-11-15

    Ultra-thin self-assembled monolayer (SAM)-oxide hybrid dielectrics have gained significant interest for their application in low-voltage organic thin film transistors (OTFTs). A [8-(11-phenoxy-undecyloxy)-octyl]phosphonic acid (PhO-19-PA) SAM on ultrathin AlOx (2.5 nm) has been developed to significantly enhance the dielectric performance of inorganic oxides through reduction of leakage current while maintaining similar capacitance to the underlying oxide structure. Rapid processing of this SAM in ambient conditions is achieved by spin coating, however, as-cast monolayer density is not sufficient for dielectric applications. Thermal annealing of a bulk spun-cast PhO-19-PA molecular film is explored as a mechanism for SAM densification. SAM density, or surface coverage, and order are examined as a function of annealing temperature. These SAM characteristics are probed through atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and near edge X-ray absorption fine structure spectroscopy (NEXAFS). It is found that at temperatures sufficient to melt the as-cast bulk molecular film, SAM densification is achieved; leading to a rapid processing technique for high performance SAM-oxide hybrid dielectric systems utilizing a single wet processing step. To demonstrate low-voltage devices based on this hybrid dielectric (with leakage current density of 7.7×10(-8) A cm(-2) and capacitance density of 0.62 µF cm(-2) at 3 V), pentacene thin-film transistors (OTFTs) are fabricated and yield sub 2 V operation and charge carrier mobilites of up to 1.1 cm(2) V(-1) s(-1). PMID:24288423

  20. Solid-State Densification of Spun-Cast Self-Assembled Monolayers for Use in Ultra-Thin Hybrid Dielectrics

    PubMed Central

    Hutchins, Daniel O.; Acton, Orb; Weidner, Tobias; Cernetic, Nathan; Baio, Joe E.; Castner, David G.; Ma, Hong; Jen, Alex K.-Y.

    2013-01-01

    Ultra-thin self-assembled monolayer (SAM)-oxide hybrid dielectrics have gained significant interest for their application in low-voltage organic thin film transistors (OTFTs). A [8-(11-phenoxy-undecyloxy)-octyl]phosphonic acid (PhO-19-PA) SAM on ultrathin AlOx (2.5 nm) has been developed to significantly enhance the dielectric performance of inorganic oxides through reduction of leakage current while maintaining similar capacitance to the underlying oxide structure. Rapid processing of this SAM in ambient conditions is achieved by spin coating, however, as-cast monolayer density is not sufficient for dielectric applications. Thermal annealing of a bulk spun-cast PhO-19-PA molecular film is explored as a mechanism for SAM densification. SAM density, or surface coverage, and order are examined as a function of annealing temperature. These SAM characteristics are probed through atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and near edge X-ray absorption fine structure spectroscopy (NEXAFS). It is found that at temperatures sufficient to melt the as-cast bulk molecular film, SAM densification is achieved; leading to a rapid processing technique for high performance SAM-oxide hybrid dielectric systems utilizing a single wet processing step. To demonstrate low-voltage devices based on this hybrid dielectric (with leakage current density of 7.7×10?8 A cm?2 and capacitance density of 0.62 µF cm?2 at 3 V), pentacene thin-film transistors (OTFTs) are fabricated and yield sub 2 V operation and charge carrier mobilites of up to 1.1 cm2 V?1 s?1. PMID:24288423

  1. Furnace assembly

    DOEpatents

    Panayotou, Nicholas F. (Kennewick, WA); Green, Donald R. (Richland, WA); Price, Larry S. (Pittsburg, CA)

    1985-01-01

    A method of and apparatus for heating test specimens to desired elevated temperatures for irradiation by a high energy neutron source. A furnace assembly is provided for heating two separate groups of specimens to substantially different, elevated, isothermal temperatures in a high vacuum environment while positioning the two specimen groups symmetrically at equivalent neutron irradiating positions.

  2. Assembling GRETINA

    SciTech Connect

    Lee, I-Yang

    2010-01-01

    GRETINA is the most sensitive gamma-ray detector ever built for studies of the nucleus, including how the natural elements were made in stars and supernovae, and the properties of artificial superheavy elements. GRETINA, now being assembled at Berkeley Lab's 88-Inch Cyclotron, is the first stage of GRETA, the even more powerful Gamma-Ray Energy Tracking Array.

  3. Neutronics, steady-state, and transient analyses for the Poland MARIA reactor for irradiation testing of LEU lead test fuel assemblies from CERCA : ANL independent verification results.

    SciTech Connect

    Garner, P. L.; Hanan, N. A. (Nuclear Engineering Division)

    2011-06-07

    The MARIA reactor at the Institute of Atomic Energy (IAE) in Swierk (30 km SE of Warsaw) in the Republic of Poland is considering conversion from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel assemblies (FA). The FA design in MARIA is rather unique; a suitable LEU FA has never been designed or tested. IAE has contracted with CERCA (the fuel supply portion of AREVA in France) to supply 2 lead test assemblies (LTA). The LTAs will be irradiated in MARIA to burnup level of at least 40% for both LTAs and to 60% for one LTA. IAE may decide to purchase additional LEU FAs for a full core conversion after the test irradiation. The Reactor Safety Committee within IAE and the National Atomic Energy Agency in Poland (PAA) must approve the LTA irradiation process. The approval will be based, in part, on IAE submitting revisions to portions of the Safety Analysis Report (SAR) which are affected by the insertion of the LTAs. (A similar process will be required for the full core conversion to LEU fuel.) The analysis required was established during working meetings between Argonne National Laboratory (ANL) and IAE staff during August 2006, subsequent email correspondence, and subsequent staff visits. The analysis needs to consider the current high-enriched uranium (HEU) core and 4 core configurations containing 1 and 2 LEU LTAs in various core positions. Calculations have been performed at ANL in support of the LTA irradiation. These calculations are summarized in this report and include criticality, burn-up, neutronics parameters, steady-state thermal hydraulics, and postulated transients. These calculations have been performed at the request of the IAE staff, who are performing similar calculations to be used in their SAR amendment submittal to the PAA. The ANL analysis has been performed independently from that being performed by IAE and should only be used as one step in the verification process.

  4. Molecular fibers and wires in solid-state and solution self-assemblies of cyclodextrin [2]rotaxanes.

    PubMed

    Maniam, Subashani; Cieslinski, Marta M; Lincoln, Stephen F; Onagi, Hideki; Steel, Peter J; Willis, Anthony C; Easton, Christopher J

    2008-05-15

    Cyclodextrin [2]rotaxanes have been prepared by coupling dimethylanilines with dicarboxylic acids using DMT-MM, in aqueous solutions of alpha-cyclodextrin, and the example illustrated shows unusual fluorescence emission and other spectroscopic behavior characteristic of the formation of molecular wires in solution, similar to the fibers observed in the solid state. PMID:18410119

  5. Self-assembly of liquid crystal block copolymer PEG-b-smectic polymer in pure state and in dilute aqueous solution

    E-print Network

    B. Xu; R. Pinol; M. Nono-Djamen; S. Pensec; P. Keller; P. -A. Albouy; D. Levy; M. -H. Li

    2009-09-03

    A series of amphiphilic LC block copolymers, in which the hydrophobic block is a smectic polymer poly(4-methoxyphenyl 4-(6-acryloyloxy-hexyloxy)-benzoate) (PA6ester1) and the hydrophilic block is polyethyleneglycol (PEG), were synthesized and characterized. The self-assembly of one of them in both the pure state and the dilute aqueous solution was investigated in detail. Nano-structures in the pure state were studied by SAXS and WAXS on samples aligned by a magnetic field. A hexagonal cylindrical micro-segregation phase was observed with a lattice distance of 11.2 nm. The PEG blocks are in the cylinder, while the smectic polymer blocks form a matrix with layer spacing 2.4 nm and layer normal parallel to the long axis of the cylinders. Faceted unilamellar polymer vesicles, polymersomes, were formed in water, as revealed by cryo-TEM. In the lyotropic bilayer membrane of these polymersomes, the thermotropic smectic order in the hydrophobic block is clearly visible with layer normal parallel to the membrane surface.

  6. J-aggregation, its impact on excited state dynamics and unique solvent effects on macroscopic assembly of a core-substituted naphthalenediimide.

    PubMed

    Kar, Haridas; Gehrig, Dominik W; Laquai, Frédéric; Ghosh, Suhrit

    2015-04-21

    Herein we reveal a straightforward supramolecular design for the H-bonding driven J-aggregation of an amine-substituted cNDI in aliphatic hydrocarbons. Transient absorption spectroscopy reveals sub-ps intramolecular electron transfer in isolated NDI molecules in a THF solution followed by a fast recombination process, while a remarkable extension of the excited state lifetime by more than one order of magnitude occurred in methylcyclohexane likely owing to an increased charge-separation as a result of better delocalization of the charge-separated states in J-aggregates. We also describe unique solvent-effects on the macroscopic structure and morphology. While J-aggregation with similar photophysical characteristics was noticed in all the tested aliphatic hydrocarbons, the morphology strongly depends on the "structure" of the solvents. In linear hydrocarbons (n-hexane, n-octane, n-decane or n-dodecane), formation of an entangled fibrillar network leads to macroscopic gelation while in cyclic hydrocarbons (methylcyclohexane or cyclohexane) although having a similar polarity, the cNDI exhibits nanoscale spherical particles. These unprecedented solvent effects were rationalized by establishing structure-dependent specific interactions of the solvent molecules with the cNDI which may serve as a general guideline for solvent-induced morphology-control of structurally related self-assembled materials. PMID:25805563

  7. Quantum box energies as a route to the ground state levels of self-assembled InAs pyramidal dots

    Microsoft Academic Search

    M. Califano; P. Harrison

    2000-01-01

    A theoretical investigation of the ground state electronic structure of InAs\\/GaAs quantum confined structures is presented. Energy levels of cuboids and pyramidal shaped dots are calculated using a single-band, constant-confining-potential model that in former applications has proved to reproduce well both the predictions of very sophisticated treatments and several features of many experimental photoluminescence spectra. A connection rule between their

  8. Cartwheel assembly.

    PubMed

    Hirono, Masafumi

    2014-09-01

    The cartwheel is a subcentriolar structure consisting of a central hub and nine radially arranged spokes, located at the proximal end of the centriole. It appears at the initial stage of the centriole assembly process as the first ninefold symmetrical structure. The cartwheel was first described more than 50 years ago, but it is only recently that its pivotal role in establishing the ninefold symmetry of the centriole was demonstrated. Significant progress has since been made in understanding its fine structure and assembly mechanism. Most importantly, the central part of the cartwheel, from which the ninefold symmetry originates, is shown to form by self-association of nine dimers of the protein SAS-6. This finding, together with emerging data on other components of the cartwheel, has opened new avenues in centrosome biology. PMID:25047612

  9. Dump assembly

    DOEpatents

    Goldmann, Louis H. (Benton City, WA)

    1986-01-01

    A dump assembly having a fixed conduit and a rotatable conduit provided with overlapping plates, respectively, at their adjacent ends. The plates are formed with openings, respectively, normally offset from each other to block flow. The other end of the rotatable conduit is provided with means for securing the open end of a filled container thereto. Rotation of the rotatable conduit raises and inverts the container to empty the contents while concurrently aligning the conduit openings to permit flow of material therethrough.

  10. Sensor assembly

    DOEpatents

    Bennett, Thomas E.; Nelson, Drew V.

    2004-04-13

    A ribbon-like sensor assembly is described wherein a length of an optical fiber embedded within a similar lengths of a prepreg tow. The fiber is ""sandwiched"" by two layers of the prepreg tow which are merged to form a single consolidated ribbon. The consolidated ribbon achieving a generally uniform distribution of composite filaments near the embedded fiber such that excess resin does not ""pool"" around the periphery of the embedded fiber.

  11. Single-Molecule Spectroscopy Unmasks the Lowest Exciton State of the B850 Assembly in LH2 from Rps. acidophila

    PubMed Central

    Kunz, Ralf; Timpmann, Kõu; Southall, June; Cogdell, Richard J.; Freiberg, Arvi; Köhler, Jürgen

    2014-01-01

    We have recorded fluorescence-excitation and emission spectra from single LH2 complexes from Rhodopseudomonas (Rps.) acidophila. Both types of spectra show strong temporal spectral fluctuations that can be visualized as spectral diffusion plots. Comparison of the excitation and emission spectra reveals that for most of the complexes the lowest exciton transition is not observable in the excitation spectra due to the cutoff of the detection filter characteristics. However, from the spectral diffusion plots we have the full spectral and temporal information at hand and can select those complexes for which the excitation spectra are complete. Correlating the red most spectral feature of the excitation spectrum with the blue most spectral feature of the emission spectrum allows an unambiguous assignment of the lowest exciton state. Hence, application of fluorescence-excitation and emission spectroscopy on the same individual LH2 complex allows us to decipher spectral subtleties that are usually hidden in traditional ensemble spectroscopy. PMID:24806933

  12. Axial Chiral Bisbenzophenazines: Solid-State Self-Assembly via Halide Hydrogen Bonds Triggered by Linear Alkanes

    PubMed Central

    2015-01-01

    An axial chiral tetrachlorinated bisbenzo[a]phenazine has been discovered that undergoes an alkane-induced shift in the solid state from a disordered amorphous form to an ordered polycrystalline form. This phase transition is caused by the formation of pores that accommodate linear alkanes of varying lengths with a very strong affinity as judged by differential scanning calorimetry. Single crystal X-ray structure analysis revealed that a series of weak phenolic OH···Cl hydrogen bonds dictates the pore structure. These weak interactions can be disrupted mechanically, causing the material to revert to the amorphous form. Notably, the interchange between the amorphous and crystalline forms is readily reversible and is easily observed by characteristic colorimetric changes. Measurements via photoimage processing reveal that the degree of color change is dictated by the type of alkane employed. PMID:25019179

  13. Anion-controlled assembly of silver-di(aminophenyl)sulfone coordination polymers: Syntheses, crystal structures, and solid state luminescence

    NASA Astrophysics Data System (ADS)

    Zhang, Qi-Long; Hu, Peng; Zhao, Yi; Feng, Guang-Wei; Zhang, Yun-Qian; Zhu, Bi-Xue; Tao, Zhu

    2014-02-01

    Five silver coordination polymers, namely, {[Ag(3,3?-daps)2]·BF4}n (1), {[Ag(3,3?-daps)2]·NO3}n (2), [Ag(3,3?-daps)(CF3SO3)]n (3), {[Ag(4,4?-daps)]·CF3SO3}n (4), and {[Ag(4,4?-daps)]·ClO4}n (5) (3,3?-daps=di(3?-aminodiphenyl)sulfone, and 4,4?-daps=di(4?-aminodiphenyl)sulfone) have been synthesized and structural characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction analyses. Complex 1 displays a 1D ladder-like chain with four-connected Ag ions and bridged 3,3?-daps. Complex 2 shows other 1D ladder chain modified by tentacles. Complex 3 is a 2D layer structure with both Ag ions and 3,3?-daps are 3-connected nodes. Complex 4 is another 1D ladder chain with three-connected Ag ions and 4,4?-daps. Complex 5 shows a 2D 44-sql net with Ag ions and 4,4?-daps as 4-connected nodes. Moreover, their solid state luminescence and thermal stabilities also have been investigated.

  14. Dump assembly

    DOEpatents

    Goldmann, L.H.

    1984-12-06

    This is a claim for a dump assembly having a fixed conduit and a rotatable conduit provided with overlapping plates, respectively, at their adjacent ends. The plates are formed with openings, respectively, normally offset from each other to block flow. The other end of the rotatable conduit is provided with means for securing the open end of a filled container thereto. Rotation of the rotatable conduit raises and inverts the container to empty the contents while concurrently aligning the conduit openings to permit flow of material therethrough. 4 figs.

  15. Shingle assembly

    DOEpatents

    Dinwoodie, Thomas L.

    2007-02-20

    A barrier, such as a PV module, is secured to a base by a support to create a shingle assembly with a venting region defined between the barrier and base for temperature regulation. The first edge of one base may be interengageable with the second edge of an adjacent base to be capable of resisting first and second disengaging forces oriented perpendicular to the edges and along planes oriented parallel to and perpendicular to the base. A deflector may be used to help reduce wind uplift forces.

  16. Thermocouple assembly

    DOEpatents

    Thermos, Anthony Constantine (Greer, SC); Rahal, Fadi Elias (Easley, SC)

    2002-01-01

    A thermocouple assembly includes a thermocouple; a plurality of lead wires extending from the thermocouple; an insulating jacket extending along and enclosing the plurality of leads; and at least one internally sealed area within the insulating jacket to prevent fluid leakage along and within the insulating jacket. The invention also provides a method of preventing leakage of a fluid along and through an insulating jacket of a thermocouple including the steps of a) attaching a plurality of lead wires to a thermocouple; b) adding a heat sensitive pseudo-wire to extend along the plurality of lead wires; c) enclosing the lead wires and pseudo-wire inside an insulating jacket; d) locally heating axially spaced portions of the insulating jacket to a temperature which melts the pseudo-wire and fuses it with an interior surface of the jacket.

  17. IAHS Third Scientific Assembly

    NASA Astrophysics Data System (ADS)

    The International Association of Hydrological Sciences (IAHS) convened its Third Scientific Assembly in Baltimore, Md., May 10-19, 1989. The Assembly was attended by about 450 scientists and engineers. The attendance was highest from the U.S., as could be expected; 37 were from Canada; 22 each, Netherlands and United Kingdom; 14, Italy; 12, China; 10, Federal Republic of Germany; 8 each from France, the Republic of South Africa, and Switzerland; 7, Austria; 6 each, Finland and Japan; others were scattered among the remainder of 48 countries total.one of the cosponsors and also handled business matters for the Assembly. Other cosponsors included the International Association of Meteorology and Atmospheric Physics (IAMAP), United Nations Environmental Program (UNEP), United Nations Educational, Scientific, and Cultural Organization (UNESCO), World Meteorological Organization (WMO), and U.K. Overseas Development Authority (ODA). U.S. federal agencies serving as cosponsors included the Environmental Protection Agency, National Aeronautics and Space Administration, National Science Foundation, National Weather Service, Department of Agriculture, Department of State, and U.S. Geological Survey.

  18. Dynamics of benzene guest inside a self-assembled cylindrical capsule: a combined solid-state 2H NMR and molecular dynamics simulation study.

    PubMed

    Albunia, Alexandra R; Gaeta, Carmine; Neri, Placido; Grassi, Alfonso; Milano, Giuseppe

    2006-10-01

    The reorientational dynamics of benzene-d(6) molecules hosted into the cavity of a cavitand-based, self-assembled capsule was investigated by Molecular Dynamics (MD) simulations and temperature-dependent solid-state (2)H NMR spectroscopy. MD simulations were preliminarily performed to assess the motional models of the guest molecules inside the capsules. An in-plane fast reorientation of the benzene guest around the C(6) symmetry axis (B1 motion), characterized by correlation times of the order of picoseconds, was predicted with an activation barrier ( approximately 8 kJ/mol) very similar to that found for neat benzene in the liquid state. An out-of-plane reorientation corresponding to a nutation of the C(6) symmetry axis in a cone angle of 39 degrees (B2 motion, 373 K) with an activation barrier ( approximately 39 kJ/mol) definitely larger than that of liquid benzene was also anticipated. In the temperature range 293-373 K correlation times of the order of a nanosecond have been calculated and a transition from fast to slow regime in the (2)H NMR scale has been predicted between 293 and 173 K. (2)H NMR spectroscopic analysis, carried out in the temperature range 173-373 K on the solid capsules containing the perdeuterated guest (two benzene molecules/capsule), confirmed the occurrence of the B1 and B2 motions found in slow exchange in the (2)H NMR time scale. Line shape simulation of the (2)H NMR spectral lines permitted defining a cone angle value of 39 degrees at 373 K and 35 degrees at 173 K for the nutation axis. The T(1) values measured for the (2)H nuclei of the encapsulated aromatic guest gave correlation times and energetic barrier for the in-plane motion B1 in fine agreement with theoretical calculation. The experimental correlation time for B2 as well as the corresponding energetic barrier are in the same range found for B1. A molecular mechanism for the encapsulated guest accounting for the B1 and B2 motions was also provided. PMID:17004770

  19. Anchor bolt assembly

    SciTech Connect

    Lillis, J.W.; Unger, R.D.

    1988-03-24

    A bolt assembly for securing a bolt in a bore hole having a settable bonding material is described comprising in combination (a) an elongated bolt, (b) means for mixing at least a portion of the bonding material in the bore hole upon rotation of the bolt, (c) support means engaged by the bolt for applying force against an area surrounding the mouth of the bore hold comprising first and second support members positioned on the bolt, (d) means for tensioning the bolt in the bore hole as the bonding material sets to a hardened state.

  20. Assembly Line Balancing with Multiple Stations

    Microsoft Academic Search

    G. M. Buxey

    1974-01-01

    A case is stated for extending the techniques of assembly line balancing to provide for the parallel operation of identical stations, where this leads to a reduction in idle time. The practical implications of operating with this type of system are discussed, both for the stations themselves and the line as a whole, with reference to various classifications of assembly

  1. Yeast prions assembly and propagation

    PubMed Central

    2011-01-01

    Yeast prions are self-perpetuating protein aggregates that are at the origin of heritable and transmissible non-Mendelian phenotypic traits. Among these, [PSI+], [URE3] and [PIN+] are the most well documented prions and arise from the assembly of Sup35p, Ure2p and Rnq1p, respectively, into insoluble fibrillar assemblies. Fibril assembly depends on the presence of N- or C-terminal prion domains (PrDs) which are not homologous in sequence but share unusual amino-acid compositions, such as enrichment in polar residues (glutamines and asparagines) or the presence of oligopeptide repeats. Purified PrDs form amyloid fibrils that can convert prion-free cells to the prion state upon transformation. Nonetheless, isolated PrDs and full-length prion proteins have different aggregation, structural and infectious properties. In addition, mutations in the “non-prion” domains (non-PrDs) of Sup35p, Ure2p and Rnq1p were shown to affect their prion properties in vitro and in vivo. Despite these evidences, the implication of the functional non-PrDs in fibril assembly and prion propagation has been mostly overlooked. In this review, we discuss the contribution of non-PrDs to prion assemblies, and the structure-function relationship in prion infectivity in the light of recent findings on Sup35p and Ure2p assembly into infectious fibrils from our laboratory and others. PMID:22052349

  2. Microsphere assembly of TiO2 mesoporous nanosheets with highly exposed (101) facets and application in a light-trapping quasi-solid-state dye-sensitized solar cell.

    PubMed

    Tao, Xiyun; Ruan, Peng; Zhang, Xiang; Sun, Hongxia; Zhou, Xingfu

    2015-02-28

    The morphology of nano-titania has a significant effect on the photoelectric properties of dye-sensitized solar cells. In this study, microsphere assembly of a TiO2 mesoporous nanosheet constructed by nanocuboids was conducted via a simple hydrothermal process. The XRD pattern indicated that the hierarchical mesoporous microspheres are anatase phase with decreased (004) peaks. Raman spectrum shows enhanced Eg peaks at 143 and 638 cm(-1) caused by the symmetric stretching vibration of O-Ti-O of the (101) crystalline facet in anatase TiO2. FESEM and TEM images show that well monodispersed TiO2 microspheres with a diameter of 2 ?m are assembled by TiO2 mesoporous nanosheets with exposed (101) facets. The oriented attachment of TiO2 nanocuboids along the (101) direction leads to the formation of mesoporous titania nanosheets. The UV-Vis spectrum shows that the mesoporous TiO2 nanosheets have high scattering ability and light absorption by dye. Quasi-solid-state dye-sensitized solar cells that incorporate these microspheres into the top scattering layers exhibit a prominent improvement in the power conversion efficiency of 7.51%, which shows a 45.8% increase in the overall conversion efficiency when compared with the spine hierarchical TiO2 microspheres (5.15%). There is the potential application for microsphere assembly of mesoporous TiO2 nanosheets in quasi-solid-state dye-sensitized solar cells with excellent stability. PMID:25631573

  3. Radiation Chemistry in Organized Assemblies.

    ERIC Educational Resources Information Center

    Thomas, J. K.; Chen, T. S.

    1981-01-01

    Expands the basic concepts regarding the radiation chemistry of simple aqueous systems to more complex, but well defined, organized assemblies. Discusses the differences in behavior in comparison to simple systems. Reviews these techniques: pulse radiolysis, laser flash, photolysis, and steady state irradiation by gamma rays or light. (CS)

  4. Latching relay switch assembly

    DOEpatents

    Duimstra, Frederick A. (Anaheim Hills, CA)

    1991-01-01

    A latching relay switch assembly which includes a coil section and a switch or contact section. The coil section includes at least one permanent magnet and at least one electromagnet. The respective sections are, generally, arranged in separate locations or cavities in the assembly. The switch is latched by a permanent magnet assembly and selectively switched by an overriding electromagnetic assembly.

  5. A Discrete Event Controller Using Petri Nets Applied To Assembly

    Microsoft Academic Search

    B. J. McCarragher; H. Asacla

    1992-01-01

    paper takes a new approach to robotic assembly, treating assembly as a discrete event system. A discrete event in assembly is defined as a change in contact state reflecting a change in a ge- ometric constraint. The discrete event modelling is ac~complished using Petri nets. The problems of task-level planning .and syn- thesis are addressed. Using the Petri net modelling,

  6. Tilt assembly for tracking solar collector assembly

    DOEpatents

    Almy, Charles; Peurach, John; Sandler, Reuben

    2012-01-24

    A tilt assembly is used with a solar collector assembly of the type comprising a frame, supporting a solar collector, for movement about a tilt axis by pivoting a drive element between first and second orientations. The tilt assembly comprises a drive element coupler connected to the drive element and a driver, the driver comprising a drive frame, a drive arm and a drive arm driver. The drive arm is mounted to the drive frame for pivotal movement about a drive arm axis. Movement on the drive arm mimics movement of the drive element. Drive element couplers can extend in opposite directions from the outer portion of the drive arm, whereby the assembly can be used between adjacent solar collector assemblies in a row of solar collector assemblies.

  7. 1D Co2.18Ni0.82Si2O5(OH)4 architectures assembled by ultrathin nanoflakes for high-performance flexible solid-state asymmetric supercapacitors

    NASA Astrophysics Data System (ADS)

    Zhao, Junhong; Zheng, Mingbo; Run, Zhen; Xia, Jing; Sun, Mengjun; Pang, Huan

    2015-07-01

    1D Co2.18Ni0.82Si2O5(OH)4 architectures assembled by ultrathin nanoflakes are synthesized for the first time by a hydrothermal method. We present a self-reacting template method to synthesize 1D Co2.18Ni0.82Si2O5(OH)4 architectures using Ni(SO4)0.3(OH)1.4 nanobelts. A high-performance flexible asymmetric solid-state supercapacitor can be successfully fabricated based on the 1D Co2.18Ni0.82Si2O5(OH)4 architectures and graphene nanosheets. Interestingly, the as-assembled 1D Co2.18Ni0.82Si2O5(OH)4 architectures//Graphene nanosheets asymmetric solid-state supercapacitor can achieve a maximum energy density of 0.496 mWh cm-3, which is higher than most of reported solid state supercapacitors. Additionally, the device shows high cycle stability for 10,000 cycles. These features make the 1D Co2.18Ni0.82Si2O5(OH)4 architectures as one of the most promising candidates for high-performance energy storage devices.

  8. Electronic Properties and Structure of Assemblies of CdSe Nanocrystal Quantum Dots and Ru-Polypyridine Complexes Probed by Steady State and Time-Resolved Photoluminescence

    SciTech Connect

    Koposov, Alexey Y. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Szymanski, Paul [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Cardolaccia, Thomas [Univ. North Carolina, Chapel Hill, NC (United States); Meyer, Thomas J. [Univ. North Carolina, Chapel Hill, NC (United States); Klimov, Victor I. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Sykora, Milan [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

    2011-08-23

    Chemical and electronic interactions between CdSe nanocrystal quantum dots (NQDs) and Ru-polypyridine complexes are studied in solution. It is shown that photoluminescence (PL) can be used to effectively monitor the formation of NQD-complex assemblies in real time. It is also shown that with the aid of Langmuir isotherm modeling, the PL studies can be used to quantitatively characterize the composition of the assemblies and the strength of electronic interactions between their components. The approach demonstrated here is general and can be applied to other systems that combine semiconductor NQDs and appropriately functionalized organometallic or organic molecules interacting with NQDs via energy transfer, charge transfer, or other mechanisms leading to quenching of NQD emission.

  9. Self-assembly behavior of tail-to-tail superstructure formed by mono-6-O-(4-carbamoylmethoxy-benzoyl)-?-cyclodextrin in solution and the solid state.

    PubMed

    Xu, Zhe; Chen, Xin; Liu, Jing; Yan, Dong-Qing; Diao, Chun-Hua; Guo, Min-Jie; Fan, Zhi

    2014-07-01

    A novel mono-modified ?-cyclodextrin (?-CD) consisting of 4-carbamoylmethoxy-benzoyl unit at the primary side was synthesized and its self-assembly behavior was determined by X-ray crystallography and NMR spectroscopy. The crystal structure shows a 'Yin-Yang'-like packing mode, in which the modified ?-CD exhibits a channel superstructure formed by a tail-to-tail dimer as the repeating motif with the substituted group embedded within the hydrophobic cavity of the facing ?-CD. The geometry of the substituted group is determined by the inclusion of the cavity and is further stabilized by two intermolecular hydrogen bonds between the carbonyl O atom and phenyl group. Furthermore, NMR ROESY investigation indicates that the self-assembly behavior of the substituted group within the ?-CD cavity is retained in aqueous solution, and the effective binding constant Ka was calculated to be 1330 M(-1) by means of (1)H NMR titration according to iterative determination. PMID:24887704

  10. Residual stress-strain state of the collector assembly of a steam generator in the process of press-fitting of heat-exchange pipes

    Microsoft Academic Search

    G. V. Stepanov; V. V. Kharchenko

    1998-01-01

    The influence technological heredity connected with the manufacturing process on the strength and service life of the assembly\\u000a of joints of the collector and heat exchange pipes of a steam generator proves to be one of the main causes of premature failures\\u000a of steam generators of water-cooled reactors of nuclear power plants. We present the results of a numerical simulation

  11. Formation and optical properties of CdTe self-assembled pyramids with quantum states grown on ZnTe buffer layers

    Microsoft Academic Search

    E. H. Lee; K. H. Lee; J. S. Kim; H. L. Park; T. W. Kim

    2003-01-01

    Atomic force microscopy (AFM) and photoluminescence (PL) measurements were carried out to investigate the structure and to determine the electron activation energy in CdTe\\/ZnTe pyramids grown by using molecular beam epitaxy and atomic layer epitaxy methods. The AFM images showed that self-assembled CdTe pyramids were formed on ZnTe buffer layers. The PL spectra showed that the formed CdTe pyramids had

  12. A novel alcohol dehydrogenase biosensor based on solid-state electrogenerated chemiluminescence by assembling dehydrogenase to Ru(bpy) 3 2+–Au nanoparticles aggregates

    Microsoft Academic Search

    Lihua Zhang; Zhiai Xu; Xuping Sun; Shaojun Dong

    2007-01-01

    Based on electrogenerated chemiluminescence (ECL), a novel method for fabrication of alcohol dehydrogenase (ADH) biosensor by self-assembling ADH to Ru(bpy)32+–AuNPs aggregates (Ru–AuNPs) on indium tin oxide (ITO) electrode surface has been developed. Positively charged Ru(bpy)32+ could be immobilized stably on the electrode surface with negatively charged AuNPs in the form of aggregate via electrostatic interaction. On the other hand, AuNPs

  13. Boulder Faculty Assembly The Boulder Faculty Assembly

    E-print Network

    Stowell, Michael

    appreciation. Faculty-Student Mentoring Program CU's new Faculty-Student Mentoring Program helps first year of students that is mentored by a faculty member. BFA Leadership Institute With the BFA Leadership InstituteBoulder Faculty Assembly The Boulder Faculty Assembly Programs and Initiatives 2013-2014 Paul S

  14. Molecular Self-Assembly

    NSDL National Science Digital Library

    2012-07-19

    In this activity, students interact with 12 models to observe emergent phenomena as molecules assemble themselves. Investigate the factors that are important to self-assembly, including shape and polarity. Try to assemble a monolayer by "pushing" the molecules to the substrate (it's not easy!). Rotate complex molecules to view their structure. Finally, create your own nanostructures by selecting molecules, adding charges to them, and observing the results of self-assembly.

  15. Membrane module assembly

    DOEpatents

    Kaschemekat, Jurgen (Palo Alto, CA)

    1994-01-01

    A membrane module assembly adapted to provide a flow path for the incoming feed stream that forces it into prolonged heat-exchanging contact with a heating or cooling mechanism. Membrane separation processes employing the module assembly are also disclosed. The assembly is particularly useful for gas separation or pervaporation.

  16. Monitoring and controlling the complex product assembly executive process via mobile agents and RFID tags

    Microsoft Academic Search

    Huibin Sun; Zhiyong Chang; Rong Mo

    2009-01-01

    Purpose – The purpose of this paper is to solve the asynchrony problem between the logistics stream and the information stream in the complex product assembly executive process. Design\\/methodology\\/approach – States of assembly and logistics are described by transitions, and implemented via logistics agents and assembly agents. Events in the assembly executive process are described by places, and mapped to

  17. Computing by molecular self-assembly

    PubMed Central

    Jonoska, Nataša; Seeman, Nadrian C.

    2012-01-01

    The paper reviews two computing models by DNA self-assembly whose proof of principal have recently been experimentally confirmed. The first model incorporates DNA nano-devices and triple crossover DNA molecules to algorithmically arrange non-DNA species. This is achieved by simulating a finite-state automaton with output where golden nanoparticles are assembled to read-out the result. In the second model, a complex DNA molecule representing a graph emerges as a solution of a computational problem. This supports the idea that in molecular self-assembly computing, it may be necessary to develop the notion of shape processing besides the classical approach through symbol processing. PMID:23919130

  18. dipSPAdes: Assembler for Highly Polymorphic Diploid Genomes.

    PubMed

    Safonova, Yana; Bankevich, Anton; Pevzner, Pavel A

    2015-06-01

    While the number of sequenced diploid genomes have been steadily increasing in the last few years, assembly of highly polymorphic (HP) diploid genomes remains challenging. As a result, there is a shortage of tools for assembling HP genomes from the next generation sequencing (NGS) data. The initial approaches to assembling HP genomes were proposed in the pre-NGS era and are not well suited for NGS projects. To address this limitation, we developed the first de Bruijn graph assembler, dipSPAdes, for HP genomes that significantly improves on the state-of-the-art assemblers for HP diploid genomes. PMID:25734602

  19. Photovoltaic assemblies and methods for transporting

    DOEpatents

    Almy, Charles; Campbell, Matt; Sandler, Reuben; Wares, Brian; Wayman, Elizabeth

    2013-09-17

    A PV assembly including framework, PV laminate(s), and a stiffening device. The framework includes a perimeter frame at least 10 feet in length and at least 5 feet in width. The PV laminate(s) are assembled to the perimeter frame to define a receiving zone having a depth of not more than 8 inches. The stiffening device is associated with the framework and is configured to provide a first state and a second state. In the first state, an entirety of the stiffening device is maintained within the receiving zone. In the second state, at least a portion of the stiffening device projects from the receiving zone. The stiffening device enhances a stiffness of the PV assembly in a plane of the perimeter frame, and can include rods defining truss structures.

  20. Photovoltaic assemblies and methods for transporting

    DOEpatents

    Almy, Charles; Campbell, Matt; Sandler, Reuben; Wares, Brian; Wayman, Elizabeth

    2014-08-05

    A PV assembly including framework, PV laminate(s), and a stiffening device. The framework includes a perimeter frame at least 10 feet in length and at least 5 feet in width. The PV laminate(s) are assembled to the perimeter frame to define a receiving zone having a depth of not more than 8 inches. The stiffening device is associated with the framework and is configured to provide a first state and a second state. In the first state, an entirety of the stiffening device is maintained within the receiving zone. In the second state, at least a portion of the stiffening device projects from the receiving zone. The stiffening device enhances a stiffness of the PV assembly in a plane of the perimeter frame, and can include rods defining truss structures.

  1. SparseAssembler2: Sparse k-mer Graph for Memory Efficient Genome Assembly

    E-print Network

    Ye, Chengxi; Ma, Zhanshan Sam; Yu, Douglas W; Pop, Mihai

    2011-01-01

    Motivation: To tackle the problem of huge memory usage associated with de Bruijn graph-based algorithms, upon which some of the most widely used de novo genome assemblers have been built, we released SparseAssembler1. SparseAssembler1 can save as much as 90% memory consumption in comparison with the state-of-art assemblers, but it requires rounds of denoising to accurately assemble genomes. In this paper, we introduce a new general model for genome assembly that uses only sparse k-mers. The new model replaces the idea of the de Bruijn graph from the beginning, and achieves similar memory efficiency and much better robustness compared with our previous SparseAssembler1. Results: Based on the sparse k-mers graph model, we develop SparseAssembler2. We demonstrate that the decomposition of reads of all overlapping k-mers, which is used in existing de Bruijn graph genome assemblers, is overly cautious. We introduce a sparse k-mer graph structure for saving sparse k-mers, which greatly reduces memory space requirem...

  2. Wind turbine rotor assembly

    SciTech Connect

    Kaiser, H. W.

    1984-11-20

    A vertical axis wind turbine having a horizontal arm member which supports an upright blade assembly. Bearing structure coupling the blade assembly to the turbine arm permits blade movement about its longitudinal axis as well as flexing motion of the blade assembly about axes perpendicular to the longitudinal axis. A latching mechanism automatically locks the blade assembly to its supporting arm during normal turbine operation and automatically unlocks same when the turbine is at rest. For overspeed prevention, a centrifugally actuated arm functions to unlatch the blade assembly permitting same to slipstream or feather into the wind. Manually actuated means are also provided for unlatching the moving blade assembly. The turbine arm additionally carries a switching mechanism in circuit with a turbine generator with said mechanism functioning to open and hence protect the generator circuit in the event of an overspeed condition of the turbine.

  3. Fuel assembly with a removable end fitting

    SciTech Connect

    Jabsen, F.S.

    1980-06-17

    A typical embodiment of the invention provides a nuclear fuel assembly lock structure for control rod guide tubes. Illustratively, a sleeve telescopes over an end portion of a control rod guide tube which bears against an internal shoulder of the tube. The upper end of the sleeve protrudes beyond the control rod guide tube spider and is locked in place by means of a resilient cellular lattice or lock that is seated in a mating groove in the outer surface of the sleeve. A special tool is provided for disengaging the entire lock structure, washer, spider, spring and grill from the end of the fuel assembly in order to enable these components to be removed in an assembled state and subsequently replaced on the fuel assembly after inspection and repair.

  4. Improving Phrap-Based Assembly of the Rat Using ``Reliable'' Overlaps

    E-print Network

    Yorke, James

    , United States of America Abstract The assembly methods used for whole-genome shotgun (WGS) data have been assembled using the whole-genome shotgun (WGS) method or a hybrid-WGS technique. In the WGS method

  5. Evidence of PPII-like helical conformation and glass transition in a self-assembled solid-state polypeptide-surfactant complex: poly(L-histidine)/docylbenzenesulfonic acid.

    PubMed

    Ramani, Ramasubbu; Hanski, Sirkku; Laiho, Ari; Tuma, Roman; Kilpeläinen, Simo; Tuomisto, Filip; Ruokolainen, Janne; Ikkala, Olli

    2008-05-01

    We present lamellar self-assembly of cationic poly(L-histidine) (PLH) stoichiometrically complexed with an anionic surfactant, dodecyl benzenesulfonic acid (DBSA), which allows a stabilized conformation reminiscent of polyproline type II (PPII) left-handed helices. Such a conformation has no intrapeptide hydrogen bonds, and it has previously been found to be one source of flexibility, e.g., in collagen and elastin, as well as an intermediate in silk processing. PLH(DBSA)1.0 complexes were characterized by Fourier transform infrared spectroscopy (FTIR), circular dichroism (CD), small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), and differential scanning calorimetry (DSC). The PPII-like conformation in PLH(DBSA)1.0 is revealed by characteristic CD and FTIR spectra, where the latter indicates absence of intrachain peptide hydrogen bonds. In addition, a glass transition was directly verified by DSC at ca. 135 degrees C for PLH(DBSA)1.0 and indirectly by SAXS and TEM in comparison to pure PLH at 165 degrees C, thus indicating plasticization. Glass transitions have not been observed before in polypeptide-surfactant complexes. The present results show that surfactant binding can be a simple scheme to provide steric crowding to stabilize PPII conformation to tune the polypeptide properties, plasticization and flexibility. PMID:18419152

  6. Exploring contribution of intermolecular interactions in supramolecular layered assembly of naphthyridine co-crystals: Insights from Hirshfeld surface analysis of their crystalline states

    NASA Astrophysics Data System (ADS)

    Seth, Saikat Kumar; Das, Nirmal Kumar; Aich, Krishnendu; Sen, Debabrata; Fun, Hoong-Kun; Goswami, Shyamaprasad

    2013-09-01

    Co-crystals of 1a and 1b have been prepared by slow evaporation of the solutions of mixtures of 2,7-dimethyl-1,8-naphthyridine (1), urea (a) and thiourea (b). The structures of the complexes are determined by the single crystal X-ray diffraction and a detailed investigation of the crystal packing and classification of intermolecular interactions is presented by means of Hirshfeld surface analysis which is of considerable current interest in crystal engineering. The X-ray study reveals that the co-crystal formers are envisioned to produce N-H⋯N hydrogen bond as well as N-H⋯O/N-H⋯S pair-wise hydrogen bonds and also the weaker aromatic ?⋯? interactions which cooperatively take part in the crystal packing. The recurring feature of the self-assembly in the compounds is the appearance of the molecular ribbon through multiple hydrogen bonding which are further stacked into molecular layers by ?⋯? stacking interactions. Hirshfeld surface analysis for visually analyzing intermolecular interactions in crystal structures employing molecular surface contours and 2D Fingerprint plots have been used to examine molecular shapes. Crystal structure analysis supported with the Hirshfeld surface and fingerprint plots enabled the identification of the significant intermolecular interactions.

  7. Single-particle study of protein assembly

    NASA Astrophysics Data System (ADS)

    Kiang, Ching-Hwa

    2001-10-01

    A study of protein assembly in solution with single-particle imaging and reconstruction techniques using cryoelectron microscopy is reported. The human glutamine synthetase enzyme, important in brain metabolism, and previously assumed to be assembled into a homogeneous quaternary structure, is found to be heterogeneous, with three oligomeric states that co-exist at room temperature. This result corrects an old structural and kinetic model determined by ensemble averaging techniques that assumed a homogeneous system. Unexpectedly fast protein dissociation kinetics results from a stabilized transition state.

  8. Solid-state capture and real-time analysis of individual T cell activation via self-assembly of binding multimeric proteins on functionalized materials surfaces

    Microsoft Academic Search

    Kerrilyn R. Diener; Susan N. Christo; Stefani S. Griesser; Ghafar T. Sarvestani; Krasimir Vasilev; Hans J. Griesser; John D. Hayball

    Polyfunctional T cell responses are increasingly underpinning new and improved vaccination regimens. Studies of the nature and extent of these T cell responses may be facilitated if specific T cell populations can be assessed from mixed populations by ligand-mediated capture in a solid-state assay format. Accordingly, we report here the development of a novel strategy for the solid-state capture and

  9. Quantum confinement-tunable intersystem crossing and the triplet state lifetime of cationic porphyrin-CdTe quantum dot nano-assemblies.

    PubMed

    Ahmed, Ghada H; Aly, Shawkat M; Usman, Anwar; Eita, Mohamed S; Melnikov, Vasily A; Mohammed, Omar F

    2015-05-11

    Here, we report a ground-state interaction between the positively charged cationic porphyrin and the negatively charged carboxylate groups of the thiol ligands on the surface of CdTe quantum dots (QDs), leading to the formation of a stable nanoassembly between the two components. Our time-resolved data clearly demonstrate that we can dramatically tune the intersystem crossing (ISC) and the triplet state lifetime of porphyrin by changing the size of the QDs in the nanoassembly. PMID:25846495

  10. Assembly oriented design

    Microsoft Academic Search

    C. J. Barnes; G. F. Dalgleish; G. E. M. Jared; H. Mei; K. G. Swift

    1999-01-01

    Product design is still commonly component rather than assembly oriented. Industry requirements have inspired a more holistic approach which is presented here. In this, proactive DFA is used in a process centred around assembly sequence construction. Early analysis and evaluation is enabled by geometric reasoning and expert system tools. Details of underlying principles and implementation are given together with a

  11. Mechanical seal assembly

    Microsoft Academic Search

    Kotlyar; Oleg M

    2002-01-01

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular

  12. Mechanical seal assembly

    Microsoft Academic Search

    Kotlyar; Oleg M

    2001-01-01

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular

  13. Mechanical Seal Assembly

    Microsoft Academic Search

    Kotlyar; Oleg M

    1999-01-01

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular

  14. Zeolite Beta nanosized assemblies

    Microsoft Academic Search

    G. Majano; S. Mintova; O. Ovsitser; B. Mihailova; T. Bein

    2005-01-01

    Nanosized zeolite Beta assemblies are prepared by a steam assisted conversion (SAC) method from micron-sized porous amorphous silica grains soaked in clear solutions containing the alumina source and organic template. The zeolite Beta assemblies are built of closely packed uniform nanocrystals (100nm) and retain the size and morphological features of the primary silica grains. The crystallinity and the phase purity

  15. Permanent magnet assembly

    DOEpatents

    Chell, Jeremy; Zimm, Carl B.

    2006-12-12

    A permanent magnet assembly is disclosed that is adapted to provide a magnetic field across an arc-shaped gap. Such a permanent magnet assembly can be used, for example, to provide a time-varying magnetic field to an annular region for use in a magnetic refrigerator.

  16. High speed door assembly

    DOEpatents

    Shapiro, C.

    1993-04-27

    A high speed door assembly is described, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  17. Rotary shaft sealing assembly

    Microsoft Academic Search

    Lannie L. Dietle; John E. Schroeder; Manmohan S. Kalsi; Patricio D. Alvarez

    2010-01-01

    A rotary shaft sealing assembly in which a first fluid is partitioned from a second fluid in a housing assembly having a rotary shaft located at least partially within. In one embodiment a lip seal is lubricated and flushed with a pressure-generating seal ring preferably having an angled diverting feature. The pressure-generating seal ring and a hydrodynamic seal may be

  18. Turbine disc sealing assembly

    DOEpatents

    Diakunchak, Ihor S.

    2013-03-05

    A disc seal assembly for use in a turbine engine. The disc seal assembly includes a plurality of outwardly extending sealing flange members that define a plurality of fluid pockets. The sealing flange members define a labyrinth flow path therebetween to limit leakage between a hot gas path and a disc cavity in the turbine engine.

  19. Liquid rocket valve assemblies

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The design and operating characteristics of valve assemblies used in liquid propellant rocket engines are discussed. The subjects considered are as follows: (1) valve selection parameters, (2) major design aspects, (3) design integration of valve subassemblies, and (4) assembly of components and functional tests. Information is provided on engine, stage, and spacecraft checkout procedures.

  20. Automated Assembly Using Feature Localization

    E-print Network

    Gordon, Steven Jeffrey

    1986-12-01

    Automated assembly of mechanical devices is studies by researching methods of operating assembly equipment in a variable manner; that is, systems which may be configured to perform many different assembly operations ...

  1. Constrained space camera assembly

    DOEpatents

    Heckendorn, Frank M. (Aiken, SC); Anderson, Erin K. (Augusta, GA); Robinson, Casandra W. (Trenton, SC); Haynes, Harriet B. (Aiken, SC)

    1999-01-01

    A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras.

  2. Superconductive radiofrequency window assembly

    DOEpatents

    Phillips, H.L.; Elliott, T.S.

    1998-05-19

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The SRF window assembly has a superconducting metal-ceramic design. The SRF window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the SRF window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator. 11 figs.

  3. Mechanisms of Virus Assembly

    NASA Astrophysics Data System (ADS)

    Perlmutter, Jason D.; Hagan, Michael F.

    2015-04-01

    Viruses are nanoscale entities containing a nucleic acid genome encased in a protein shell called a capsid and in some cases are surrounded by a lipid bilayer membrane. This review summarizes the physics that govern the processes by which capsids assemble within their host cells and in vitro. We describe the thermodynamics and kinetics for the assembly of protein subunits into icosahedral capsid shells and how these are modified in cases in which the capsid assembles around a nucleic acid or on a lipid bilayer. We present experimental and theoretical techniques used to characterize capsid assembly, and we highlight aspects of virus assembly that are likely to receive significant attention in the near future.

  4. Superconducting radiofrequency window assembly

    DOEpatents

    Phillips, H.L.; Elliott, T.S.

    1997-03-11

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly has a superconducting metal-ceramic design. The srf window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator. 11 figs.

  5. High-performance all-solid-state flexible micro-supercapacitor arrays with layer-by-layer assembled MWNT/MnOx nanocomposite electrodes

    NASA Astrophysics Data System (ADS)

    Lee, Geumbee; Kim, Daeil; Yun, Junyeong; Ko, Yongmin; Cho, Jinhan; Ha, Jeong Sook

    2014-07-01

    In this study, we report on the fabrication of high performance planar-type flexible micro-supercapacitor (MSC) arrays using Au electrodes coated with a functionalized multi-walled carbon nanotube (MWNT) film and a layer of MWNT-COOH/MnOx nanoparticle (NP) composite on top. The MWNT thin film was formed via layer-by-layer (LbL) assembly of MWNTs functionalized with amine groups and MWNTs with carboxylic acid groups in water. The hydrothermally synthesized composite of MWNT-COOH/MnOx NPs was coated on top of the MWNT film (LbL-MWNT). The addition of MWNT-COOH/MnOx NP composite as a top layer enhanced the performance of the MSCs dramatically, resulting in a volumetric capacitance of 50 F cm-3 at a scan rate of 10 mV s-1 and a coulombic efficiency of ~100%. By contrast, a volumetric capacitance of 3.6 F cm-3 was obtained when using only the LbL-MWNT film. After repetitive operation up to ~104 times, the capacitance remained at ~88.3% of the original value. With a deliberate circuit design consisting of serially connected MSC arrays, various light-emitting diodes operating at different bias voltages could be lit. The MSC circuit fabricated on a polyethylene terephthalate (PET) film showed stable electrochemical properties upon 1000 cycles of bending deformation.In this study, we report on the fabrication of high performance planar-type flexible micro-supercapacitor (MSC) arrays using Au electrodes coated with a functionalized multi-walled carbon nanotube (MWNT) film and a layer of MWNT-COOH/MnOx nanoparticle (NP) composite on top. The MWNT thin film was formed via layer-by-layer (LbL) assembly of MWNTs functionalized with amine groups and MWNTs with carboxylic acid groups in water. The hydrothermally synthesized composite of MWNT-COOH/MnOx NPs was coated on top of the MWNT film (LbL-MWNT). The addition of MWNT-COOH/MnOx NP composite as a top layer enhanced the performance of the MSCs dramatically, resulting in a volumetric capacitance of 50 F cm-3 at a scan rate of 10 mV s-1 and a coulombic efficiency of ~100%. By contrast, a volumetric capacitance of 3.6 F cm-3 was obtained when using only the LbL-MWNT film. After repetitive operation up to ~104 times, the capacitance remained at ~88.3% of the original value. With a deliberate circuit design consisting of serially connected MSC arrays, various light-emitting diodes operating at different bias voltages could be lit. The MSC circuit fabricated on a polyethylene terephthalate (PET) film showed stable electrochemical properties upon 1000 cycles of bending deformation. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr02035a

  6. Cluster-assembled metallic glasses

    PubMed Central

    2013-01-01

    A bottom-up approach to nanofabricate metallic glasses from metal clusters as building blocks is presented. Considering metallic glasses as a subclass of cluster-assembled materials, the relation between the two lively fields of metal clusters and metallic glasses is pointed out. Deposition of selected clusters or collections of them, generated by state-of-the-art cluster beam sources, could lead to the production of a well-defined amorphous material. In contrast to rapidly quenched glasses where only the composition of the glass can be controlled, in cluster-assembled glasses, one can precisely control the structural building blocks. Comparing properties of glasses with similar compositions but differing in building blocks and therefore different in structure will facilitate the study of structure–property correlation in metallic glasses. This bottom-up method provides a novel alternative path to the synthesis of glassy alloys and will contribute to improving fundamental understanding in the field of metallic glasses. It may even permit the production of glassy materials for alloys that cannot be quenched rapidly enough to circumvent crystallization. Additionally, gaining deeper insight into the parameters governing the structure–property relation in metallic glasses can have a great impact on understanding and design of other cluster-assembled materials. PMID:23899019

  7. Inverse Problem in Self-assembly

    NASA Astrophysics Data System (ADS)

    Tkachenko, Alexei

    2012-02-01

    By decorating colloids and nanoparticles with DNA, one can introduce highly selective key-lock interactions between them. This leads to a new class of systems and problems in soft condensed matter physics. In particular, this opens a possibility to solve inverse problem in self-assembly: how to build an arbitrary desired structure with the bottom-up approach? I will present a theoretical and computational analysis of the hierarchical strategy in attacking this problem. It involves self-assembly of particular building blocks (``octopus particles''), that in turn would assemble into the target structure. On a conceptual level, our approach combines elements of three different brands of programmable self assembly: DNA nanotechnology, nanoparticle-DNA assemblies and patchy colloids. I will discuss the general design principles, theoretical and practical limitations of this approach, and illustrate them with our simulation results. Our crucial result is that not only it is possible to design a system that has a given nanostructure as a ground state, but one can also program and optimize the kinetic pathway for its self-assembly.

  8. TPX assembly plan

    SciTech Connect

    Knutson, D.

    1993-11-01

    The TPX machine will be assembled in the TFTR Test Cell at the Plasma Physics Laboratory, utilizing the existing TFTR machine foundation. Preparation of the area for assembly will begin after completion of the decontamination and decommissioning phase on TFTR and certification that the radiation levels remaining, if any, are consistent with the types of operations planned. Assembly operations begin with the arrival of the first components, and conclude, approximately 24 months later, with the successful completion of the integrated systems tests and the achievement of a first plasma.

  9. A study of the reproducibility of data from steady-state tests in simulated liquid-metal fast breeder reactor fuel assemblies

    Microsoft Academic Search

    A. E. Levin; J. L. Wantland

    1984-01-01

    Data from steady-state tests in the ThermalHydraulic Out-of-Reactor Safety (THORS) facility, a large loop for testing simulated liquid metal fast breeder reactor fuel bundles at Oak Ridge National Laboratory, were examined to determine whether the results from tests at similar conditions in the same bundle are reproducible. Comparisons of different tests at similar powers and coolant flows were made for

  10. State of metallic surfaces in systems of nuclear power plants with a series 1000 high-powered-water-cooled channel reactor after assembly

    Microsoft Academic Search

    V. M. Sedov; P. G. Krutikov; A. I. Grushanin; S. T. Zolotukhin; Yu. O. Zakharzhevskii; A. P. Eperin

    1981-01-01

    We investigated the state of the surfaces by examining, photographing, and collecting samples of surface contaminants at the open ends of piping system blocks. We performed a phase analysis of the samples taken in a 3,-resonance YaGRS-4M spectrometer. We determined the specific contamination of the inner surfaces of equipment and piping system by a weight method by mechanically removing oxides

  11. An update on complex I assembly: the assembly of players.

    PubMed

    Vartak, Rasika S; Semwal, Manpreet Kaur; Bai, Yidong

    2014-08-01

    Defects in Complex I assembly is one of the emerging underlying causes of severe mitochondrial disorders. The assembly of Complex I has been difficult to understand due to its large size, dual genetic control and the number of proteins involved. Mutations in Complex I subunits as well as assembly factors have been reported to hinder its assembly and give rise to a range of mitochondria disorders. In this review, we summarize the recent progress made in understanding the Complex I assembly pathway. In particularly, we focus on the known as well as novel assembly factors and their role in assembly of Complex I and human disease. PMID:25030182

  12. The proteasome assembly line

    PubMed Central

    Madura, Kiran

    2013-01-01

    The assembly of the proteasome — the cellular machine that eliminates unwanted proteins — is a carefully choreographed affair, involving a complex sequence of steps overseen by dedicated protein chaperones. PMID:19516331

  13. Magnetic assisted statistical assembly

    E-print Network

    Cheng, Diana I

    2008-01-01

    The objective of this thesis is to develop a process using magnetic forces to assemble micro-components into recesses on silicon based integrated circuits. Patterned SmCo magnetic thin films at the bottom of recesses are ...

  14. Core assembly storage structure

    DOEpatents

    Jones, Jr., Charles E. (Northridge, CA); Brunings, Jay E. (Chatsworth, CA)

    1988-01-01

    A structure for the storage of core assemblies from a liquid metal-cooled nuclear reactor. The structure comprises an enclosed housing having a substantially flat horizontal top plate, a bottom plate and substantially vertical wall members extending therebetween. A plurality of thimble members extend downwardly through the top plate. Each thimble member is closed at its bottom end and has an open end adjacent said top plate. Each thimble member has a length and diameter greater than that of the core assembly to be stored therein. The housing is provided with an inlet duct for the admission of cooling air and an exhaust duct for the discharge of air therefrom, such that when hot core assemblies are placed in the thimbles, the heat generated will by convection cause air to flow from the inlet duct around the thimbles and out the exhaust duct maintaining the core assemblies at a safe temperature without the necessity of auxiliary powered cooling equipment.

  15. Mesoscale Polymer Assemblies

    NASA Astrophysics Data System (ADS)

    Choudhary, Satyan; Pham, Jonathan; Crosby, Alfred

    2015-03-01

    Materials encompassing structural hierarchy and multi-functionality allow for remarkable physical properties across different length scales. Mesoscale Polymer (MSP) assemblies provide a critical link, from nanometer to centimeter scales, in the definition of such hierarchical structures. Recent focus has been on exploiting these MSP assemblies for optical, electronic, photonics and biological applications. We demonstrate a novel fabrication method for MSP assemblies. Current fabrication methods restrict the length scale and volume of such assemblies. A new method developed uses a simple piezo-actuated motion for de-pinning of a polymer solution trapped by capillary forces between a flexible blade and a rigid substrate. The advantages of new method include ability to make MSP of monodisperse length and to fabricate sufficient volumes of MSP to study their physical properties and functionality in liquid dispersions. We demonstrate the application of MSP as filler for soft materials, providing rheological studies of the MSP with surrounding matrices.

  16. Rnnotator Assembly Pipeline

    SciTech Connect

    Martin, Jeff [DOE Joint Genome Institute

    2010-06-03

    Jeff Martin of the DOE Joint Genome Institute discusses a de novo transcriptome assembly pipeline from short RNA-Seq reads on June 3, 2010 at the "Sequencing, Finishing, Analysis in the Future" meeting in Santa Fe, NM

  17. Genome assembly forensics: finding the elusive mis-assembly.

    PubMed

    Phillippy, Adam M; Schatz, Michael C; Pop, Mihai

    2008-01-01

    We present the first collection of tools aimed at automated genome assembly validation. This work formalizes several mechanisms for detecting mis-assemblies, and describes their implementation in our automated validation pipeline, called amosvalidate. We demonstrate the application of our pipeline in both bacterial and eukaryotic genome assemblies, and highlight several assembly errors in both draft and finished genomes. The software described is compatible with common assembly formats and is released, open-source, at http://amos.sourceforge.net. PMID:18341692

  18. MetaVelvet-SL: an extension of the Velvet assembler to a de novo metagenomic assembler utilizing supervised learning

    PubMed Central

    Afiahayati; Sato, Kengo; Sakakibara, Yasubumi

    2015-01-01

    The assembly of multiple genomes from mixed sequence reads is a bottleneck in metagenomic analysis. A single-genome assembly program (assembler) is not capable of resolving metagenome sequences, so assemblers designed specifically for metagenomics have been developed. MetaVelvet is an extension of the single-genome assembler Velvet. It has been proved to generate assemblies with higher N50 scores and higher quality than single-genome assemblers such as Velvet and SOAPdenovo when applied to metagenomic sequence reads and is frequently used in this research community. One important open problem for MetaVelvet is its low accuracy and sensitivity in detecting chimeric nodes in the assembly (de Bruijn) graph, which prevents the generation of longer contigs and scaffolds. We have tackled this problem of classifying chimeric nodes using supervised machine learning to significantly improve the performance of MetaVelvet and developed a new tool, called MetaVelvet-SL. A Support Vector Machine is used for learning the classification model based on 94 features extracted from candidate nodes. In extensive experiments, MetaVelvet-SL outperformed the original MetaVelvet and other state-of-the-art metagenomic assemblers, IDBA-UD, Ray Meta and Omega, to reconstruct accurate longer assemblies with higher N50 scores for both simulated data sets and real data sets of human gut microbial sequences. PMID:25431440

  19. 75 FR 71412 - Meeting of the Assembly of the Administrative Conference

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-23

    ...UNITED STATES Meeting of the Assembly of the Administrative Conference...hereby given of a meeting of the Assembly of the Administrative Conference...Recommendation'' in the subject line; or (2) Mail: Plenary Preemption...plenary session constitutes the Assembly of the Conference (5...

  20. Automated Control Synthesis for an Assembly Line using Discrete Event System Control Theory

    E-print Network

    Kumar, Ratnesh

    1 Automated Control Synthesis for an Assembly Line using Discrete Event System Control Theory- tems, an educational test-bed that simulates an automated car assembly line has been built using LEGO r blocks. Finite state machines (FSMs) are used for modeling operations of the assembly line

  1. Optimization of kitting operations for an automated microelectronics assembly process

    E-print Network

    Williams, Gregory A. (Gregory Alan)

    2006-01-01

    Raytheon's Solid-State Microwave (SSM) manufacturing area produces a low-volume, high mix assortment of Microwave Integrated Circuits (MIC) for airborne radars. The current kitting process for pick-and-place assembly is ...

  2. 35. OUTLET WORKS: GATE HOIST ASSEMBLY. Sheet 44, August 20, ...

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

    35. OUTLET WORKS: GATE HOIST ASSEMBLY. Sheet 44, August 20, 1938. File no. SA 121/84(?). - Prado Dam, Outlet Works, Santa Ana River near junction of State Highways 71 & 91, Corona, Riverside County, CA

  3. International Space Station Carbon Dioxide Removal Assembly Testing

    NASA Technical Reports Server (NTRS)

    Knox, James C.

    2000-01-01

    Performance testing of the International Space Station Carbon Dioxide Removal Assembly flight hardware in the United States Laboratory during 1999 is described. The CDRA exceeded carbon dioxide performance specifications and operated flawlessly. Data from this test is presented.

  4. Assemblies of Conformal Tanks

    NASA Technical Reports Server (NTRS)

    DeLay, Tom

    2009-01-01

    Assemblies of tanks having shapes that conform to each other and/or conform to other proximate objects have been investigated for use in storing fuels and oxidizers in small available spaces in upper stages of spacecraft. Such assemblies might also prove useful in aircraft, automobiles, boats, and other terrestrial vehicles in which space available for tanks is limited. The basic concept of using conformal tanks to maximize the utilization of limited space is not new in itself: for example, conformal tanks are used in some automobiles to store windshield -washer liquid and coolant that overflows from radiators. The novelty of the present development lies in the concept of an assembly of smaller conformal tanks, as distinguished from a single larger conformal tank. In an assembly of smaller tanks, it would be possible to store different liquids in different tanks. Even if the same liquid were stored in all the tanks, the assembly would offer an advantage by reducing the mechanical disturbance caused by sloshing of fuel in a single larger tank: indeed, the requirement to reduce sloshing is critical in some applications. The figure shows a prototype assembly of conformal tanks. Each tank was fabricated by (1) copper plating a wax tank mandrel to form a liner and (2) wrapping and curing layers of graphite/epoxy composite to form a shell supporting the liner. In this case, the conformal tank surfaces are flat ones where they come in contact with the adjacent tanks. A band of fibers around the outside binds the tanks together tightly in the assembly, which has a quasi-toroidal shape. For proper functioning, it would be necessary to maintain equal pressure in all the tanks.

  5. Modifications under irradiation of a self-assembled monolayer grafted on a nano-porous silica glass: a solid-state NMR characterization

    SciTech Connect

    Le Caer, S.; Chatelain, C.; Renault, J.Ph. [CEA, CNRS, Inst Rayonnement Mat Saclay, Lab Radiolyse, SIS2M, Serv Interdisciplinaire Syst Mol et Mat, UMR 3299, F-91191 Gif Sur Yvette, (France); Brunet, F.; Charpentier, T. [CEA, Lab Struct et Dynam Resonance Magnet, CNRS, Inst Rayonnement Mat Saclay, SIS2M, Serv Interdisciplinaire Syst Mol et Mat, UMR 3299, F-91191 Gif Sur Yvette, (France); Durand, D.; Dauvois, V. [CEA Saclay, DEN, DANS, DPC, SECR, LSRM, F-91191 Gif Sur Yvette, (France)

    2012-02-15

    Controlled pore glasses with a pore size of 8 nm are grafted with chlorodimethylsilane (ClSi(CH{sub 3}){sub 2}H). The surface of the glass is carefully characterized before and after irradiation with 10 MeV electrons by solid-state NMR measurements. {sup 1}H MAS NMR experiments in one and two dimensions (2D double quantum and 2D exchange) have been used to reveal the grafting of the chlorodimethylsilane at the silica surface and evidence the formation of a homogeneous layer on the surface. Irradiation leads to a high H{sub 2} yield (3.3 * 10{sup -7} mol/J) due to the efficient cleavage of the Si H bond. Methane is detected in smaller quantities (5.5 * 10{sup -8} mol/J), indicating that the Si-H bond is preferentially cleaved over the Si-C bond. The H{sub 2} production arising from OH groups on the surface is very minor in comparison to the S- H and Si-C radiolysis. (authors)

  6. Ran modulates spindle assembly by regulating a subset of TPX2 and Kid activities including Aurora A activation

    Microsoft Academic Search

    Nadia Trieselmann; Sheri Armstrong; Jennifer Rauw; Andrew Wilde

    2003-01-01

    Ran, a GTPase in the Ras superfamily, is proposed to be a spatial regulator of microtubule spindle assembly by maintaining key spindle assembly factors in an active state close to chromatin. RanGTP is hypothesized to maintain the spindle assembly factors in the active state by binding to importin ?, part of the nuclear transport receptor complex, thereby preventing the inhibitory

  7. Microcomponent assembly for efficient contacting of fluid

    DOEpatents

    Drost, Monte K. (Richland, WA); Wegeng, Robert S. (Richland, WA); Friedrich, Michele (Prosser, WA); Hanna, William T. (Gahanna, OH); Call, Charles J. (Pasco, WA); Kurath, Dean E. (Richland, WA)

    2000-01-01

    The present invention is a fundamental method and apparatus of a microcomponent assembly that overcomes the inherent limitations of state of the art chemical separations. The fundamental element enabling miniaturization is the porous contactor contained within a microcomponent assembly for mass transfer of a working compound from a first medium to a second medium. The porous contactor has a thickness, and a plurality of pores extending through the thickness. The pores are of a geometry cooperating with a boundary tension of one or the other or both of the media thereby preventing migration of one, other or both through the microporous contactor while permitting passage of the working compound. In the microcomponent assembly, the porous contactor is placed between a first laminate such that a first space or first microplenum is formed between the microporous contactor and the first laminate. Additionally, a cover sheet provides a second space or second plenum between the porous contactor and the cover sheet.

  8. Superconducting radiofrequency window assembly

    DOEpatents

    Phillips, Harry L. (Seaford, VA); Elliott, Thomas S. (Yorktown, VA)

    1997-01-01

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator.

  9. Self-assembled all-conjugated block copolymer as an effective hole conductor for solid-state dye-sensitized solar cells.

    PubMed

    Chen, Wei-Chih; Lee, Yi-Huan; Chen, Chia-Yuan; Kau, Kuo-Chang; Lin, Lu-Yin; Dai, Chi-An; Wu, Chun-Guey; Ho, Kuo-Chuan; Wang, Juen-Kai; Wang, Leeyih

    2014-02-25

    An all-conjugated diblock copolymer, poly(2,5-dihexyloxy-p-phenylene)-b-poly(3-hexylthiophene) (PPP-b-P3HT), was synthesized and applied as a hole transport material (HTM) for the fabrication of solid-state dye-sensitized solar cells (ss-DSCs). This copolymer is characterized by an enhanced crystallinity, enabling its P3HT component to self-organize into interpenetrated and long-range-ordered crystalline fibrils upon spin-drying and ultimately endowing itself to have a faster hole mobility than that of the parent P3HT homopolymer. Transient photovoltage measurements indicate that the photovoltaic cell based on PPP-b-P3HT as the HTM has a longer electron lifetime than that of the reference device based on P3HT homopolymer. Moreover, comparing the two ss-DSCs in terms of the electrochemical impedance spectra reveals that the electron density in the TiO2 conduction band is substantially higher in the PPP-b-P3HT device than in the P3HT cell. Above observations suggest that the PPP block facilitates an intimate contact between the copolymer and dye molecules absorbed on the nanoporous TiO2 layer, which significantly enhances the performance of the resulting device. Consequently, the PPP-b-P3HT ss-DSC exhibits a promising power conversion efficiency of 4.65%. This study demonstrates that conjugated block copolymers can function as superior HTMs of highly efficient ss-DSCs. PMID:24455966

  10. Power module assembly

    DOEpatents

    Campbell, Jeremy B. (Torrance, CA); Newson, Steve (Redondo Beach, CA)

    2011-11-15

    A power module assembly of the type suitable for deployment in a vehicular power inverter, wherein the power inverter has a grounded chassis, is provided. The power module assembly comprises a conductive base layer electrically coupled to the chassis, an insulating layer disposed on the conductive base layer, a first conductive node disposed on the insulating layer, a second conductive node disposed on the insulating layer, wherein the first and second conductive nodes are electrically isolated from each other. The power module assembly also comprises a first capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the first conductive node, and further comprises a second capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the second conductive node.

  11. Hand Controller Assembly

    NASA Technical Reports Server (NTRS)

    Bandera, Pablo (Inventor); Buchele, Paul (Inventor)

    2015-01-01

    A user input device for a vehicular electrical system is provided. The user input device includes a handle sized and shaped to be gripped by a human hand and a gimbal assembly within the handle. The gimbal assembly includes a first gimbal component, a second gimbal component coupled to the first gimbal component such that the second gimbal component is rotatable relative to the first gimbal component about a first axis, and a third gimbal component coupled to the second gimbal component such that the third gimbal component is rotatable relative to the second gimbal component about a second axis.

  12. Lightweight reflector assembly

    NASA Technical Reports Server (NTRS)

    Argoud, M. J.; Jolley, J.; Walker, W. L. (inventors)

    1977-01-01

    An inexpensive, lightweight reflective assembly member having good optical quality and particularly adaptable to accommodating temperature variations without providing destructive thermal stresses and reflective slope errors is described. The reflective assembly consists of a thin sheet of glass with appropriate reflective coating and a cellular glass block substrate bonded together. The method of fabrication includes abrading the cellular substrate with an abrasive master die to form an appropriate concave surface. An adhesive is applied to the abraded surface and a lamina reflective surface is placed under a uniform pressure to conform the reflective surface onto the desired abraded surface of the substrate.

  13. Modeling Self Assembly

    NSDL National Science Digital Library

    This lesson, presented by the National Nanotechnology Infrastructure Network, covers self-assembly of molecules. Two activity are contained in this lesson. The first is "a hands-on modeling activity designed to introduce students to the area of nanotechnology and give them a basic understanding of how researchers build very small devices by the self-assembly of molecules." The second activity follows up on the first and gives "the students a chance to practice and demonstrate what they have learned." Two Teacher Preparation Guides and Two Student Guides are included. 

  14. Suppression mechanisms of COX assembly defects in yeast and human: Insights into the COX assembly process

    PubMed Central

    Barrientos, Antoni; Gouget, Karine; Horn, Darryl; Soto, Ileana C.; Fontanesi, Flavia

    2008-01-01

    Eukaryotic cytochrome c oxidase (COX) is the terminal enzyme of the mitochondrial respiratory chain. COX is a multimeric enzyme formed by subunits of dual genetic origin whose assembly is intricate and highly regulated. In addition to the structural subunits, a large number of accessory factors are required to build the holoenzyme. The function of these factors is required in all stages of the assembly process. They are relevant to human health because devastating human disorders have been associated with mutations in nuclear genes encoding conserved COX assembly factors. The study of yeast strains and human cell lines from patients carrying mutations in structural subunits and COX assembly factors has been invaluable to attain the current state of knowledge, even if still fragmentary, of the COX assembly process. After the identification of the genes involved, the isolation and characterization of genetic and metabolic suppressors of COX assembly defects, reviewed here, have become a profitable strategy to gain insight into their functions and the pathways in which they operate. Additionally, they have the potential to provide useful information for devising therapeutic approaches to combat human disorders associated with COX deficiency. PMID:18522805

  15. Directed Assembly of Biological Polymers

    NASA Astrophysics Data System (ADS)

    Miller, Aline

    2009-03-01

    The self-assembly of polypeptides into beta-sheet rich nanofibrils has attracted considerable attention in recent years to both understand amyloidgenesis and for their potential biomaterials applications. This self-assembly process is generic to all proteins where fibrillation is typically induced under harsh conditions of low pH and/or high temperature, which are of course not suitable for biomaterials applications. Here we will outline the method developed in our laboratory to create thermo-reversible fibrillar hydrogels from aqueous solutions of a series of proteins by adding a reductant. Proteins studied include beta-lactoglobulin, ovalbimum, lysozyme and bovine serum albimum; all contain an increasing number of disulfide bridges that are disrupted by the reductant. Such disruption destabilises the native state of the protein and this allows us to form transparent, self-supporting hydrogels under physiological conditions. The potential to control and manipulate the gel properties, including mechanical strength and structure (fibre diameter and mesh size of hydrogel) has been explored by varying the protein (consequently the number of disulfide bridges), protein concentration, reductant concentration and ionic strength of the matrix. Our results will be presented here and similarities and differences highlighted. Furthermore we will present both our 2- and 3-dimensional cell culture experiments that show the gel matrix promotes both fibroblast and chondrocyte cell spreading, attachment and proliferation; indicating our hydrogels gels are biocompatible and they can provide a viable support for different cell types.

  16. A framework for geometric reasoning about tools in assembly

    SciTech Connect

    Wilson, R.H.

    1995-12-31

    When assembling a product, humans, robots, and other automation employ a variety of tools to manipulate, attach, and test parts and subassemblies. This paper proposes a framework lo represent and reason about geometric accessibility constraints for a wide variety of assembly tools. Central to the framework is a use volume encoding a minimum space that must be free in an assembly state to apply a given tool, and placement constraints on where that volume must be placed relative to the parts on which the tool acts. Determining whether a tool can be applied in a given assembly state is an instance of the FINDPLACE problem. In addition, we present more efficient methods lo integrate the framework into assembly planning. For tools that are applied either before or after their target parts are mated, one method preprocesses a single tool application for all possible states of assembly of a product. For tools applied after their target parts are mated, a complementary method guarantees polynomial-time assembly planning. We describe experiments with an initial implementation of the framework and a library of seven tools.

  17. Assembly and Automation Expo highlights innovations in automated assembly

    Microsoft Academic Search

    Richard Bloss

    2011-01-01

    Purpose – The purpose of this paper is to review the automated assembly technology at the Assembly and Automation Expo. While assembly is the feature show, it combines with manufacturing of electronics, plastics and medical devices at the same venue. Design\\/methodology\\/approach – In-depth interviews with exhibitors of automated systems, system integrators as well as suppliers of related components motion elements,

  18. Self-Assembling Circuits Plasticity in Self-Assembly: Templating

    E-print Network

    Prentiss, Mara

    ] Neural circuits follow an adaptive, bottom- up plan, and assemble themselves of individual componentsSelf-Assembling Circuits Plasticity in Self-Assembly: Templating Generates Functionally Different Circuits from a Single Precursor** Mila Boncheva, Rosaria Ferrigno, Derek A. Bruzewicz, and George M

  19. Perceptions and viewpoints on proceedings of the Fifteenth Assembly of Heads of State and Government of the African Union Debate on Maternal, Newborn and Child Health and Development, 25–27 July 2010, Kampala, Uganda

    PubMed Central

    2011-01-01

    Background Out of 358000 maternal deaths that occurred globally in 2008, 57.8% occurred in continental Africa. Africa had a maternal mortality ratio of 590 compared to 14 in developed regions, 68 in Latin America and Caribbean, and 190 in Asia. This article reflects on the discussions held during the Fifteenth Assembly of the Heads of State and Government of the African Union on the reasons why the maternal mortality ratio is so high in Africa and what can be done to reduce it. Methods Methods employed included panel and open public discussions among the Heads of State and Government of the African Union. The article uses the WHO health systems strengthening framework, which consists of six pillars (information systems, leadership and governance, health workforce, financing, and medical products, vaccines and technologies, and health services) to describe the proceedings of the discussions. Discussion The high maternal mortality ratios in countries were attributed to weak national health information systems; leadership and governance challenges related to poverty, health illiteracy, poor transport networks and communications infrastructure, risky cultural practices, armed conflicts and domestic violence, dearth of women empowerment; inadequate levels of skilled birth attendants; inadequate domestic and external funding; stock-outs of consumable inputs; and limited coverage of maternal and child health interventions. In order to accelerate progress towards MDGs 4 and 5, the Heads of State and Government recommended that countries should make maternal deaths notifiable and institutionalize maternal death audits; develop, fund and implement policies and strategies geared at improving maternal, newborn and child health; accelerate inter-sectoral action to address the broad health determinants; increase the number of skilled birth attendants; fulfil commitment to allocate at least 15% of the national budget to the health sector and allocate adequate resources to prevent stock-outs of essential medicines and reproductive health commodities; leverage health promotion approaches to raise national awareness; and ensure that there is a health centre within a radius of four kilometres equipped to provide good quality integrated maternal, newborn and child health services. Conclusions There was consensus among the discussants that there was urgent need to speed up actions for strengthening health systems to improve coverage of maternal, newborn and child health services; and to address broad determinants of women, newborn and children’s health for sustained improvements in health and other development goals. PMID:21810211

  20. Solar collector assembly

    SciTech Connect

    Murphy, J.A.

    1980-09-09

    A solar collector assembly includes shingles which have integral tubes projecting therefrom, and which are mounted in overlapping parallel array. Mounting brackets for the shingles are engaged on roof rafters or the like, and interlocked light transmissive plates overlie the shingles. The plates are also engaged with shingle components. A special fitting for the tube ends is provided.

  1. Solar collector assembly

    Microsoft Academic Search

    1980-01-01

    A solar collector assembly includes shingles which have integral tubes projecting therefrom, and which are mounted in overlapping parallel array. Mounting brackets for the shingles are engaged on roof rafters or the like, and interlocked light transmissive plates overlie the shingles. The plates are also engaged with shingle components. A special fitting for the tube ends is provided.

  2. Walking boot assembly

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C.; Chambers, A. B.; Stjohn, R. H. (inventors)

    1977-01-01

    A walking boot assembly particularly suited for use with a positively pressurized spacesuit is presented. A bootie adapted to be secured to the foot of a wearer, an hermetically sealed boot for receiving the bootie having a walking sole, an inner sole, and an upper portion adapted to be attached to an ankle joint of a spacesuit, are also described.

  3. Assembling Multicolor Printing Plates

    NASA Technical Reports Server (NTRS)

    Waters, W. J.

    1982-01-01

    Improved joining method uses wave-soldering techniques developed for integrated-circuit-board assemblies. Thermosetting plastic is replaced by wave soldering, which applies a thin even coat of solder to mating copper surfaces. This is done after ink holes and channels have been protected by water-soluble, high-temperature solder mask which prevents wetting and clogging.

  4. Lageos assembly operation plan

    NASA Technical Reports Server (NTRS)

    Brueger, J.

    1975-01-01

    Guidelines and constraints procedures for LAGEOS assembly, operation, and design performance are given. Special attention was given to thermal, optical, and dynamic analysis and testing. The operation procedures illustrate the interrelation and sequence of tasks in a flow diagram. The diagram also includes quality assurance functions for verification of operation tasks.

  5. Admission mixing duct assembly

    NASA Technical Reports Server (NTRS)

    Orlando, Robert J. (Inventor); Dunbar, Lawrence W. (Inventor)

    1995-01-01

    A variable cycle jet engine is provided with a mixing duct assembly which mixes core engine exhaust gas with bypass air when the engine is operating in a turbofan mode and which blocks flow from the core engine and isolates the core engine from the bypass flow when the engine is operating as a ramjet.

  6. Segmented stator assembly

    DOEpatents

    Lokhandwalla, Murtuza; Alexander, James Pellegrino; El-Refaie, Ayman Mohamed Fawzi; Shah, Manoj Ramprasad; Quirion, Owen Scott

    2013-04-02

    An electric machine and stator assembly are provided that include a continuous stator portion having stator teeth, and a tooth tip portion including tooth tips corresponding to the stator teeth of the continuous stator portion, respectively. The tooth tip portion is mounted onto the continuous stator portion.

  7. Dump valve assembly

    DOEpatents

    Owen, T.J.

    1984-01-01

    A dump valve assembly comprising a body having a bore defined by a tapered wall and a truncated spherical valve member adapted to seat along a spherical surface portion thereof against said tapered wall. Means are provided for pivoting said valve member between a closed position engagable with said tapered wall and an open position disengaged therefrom.

  8. Balancing Stochastic Assembly Lines

    Microsoft Academic Search

    N. Richard Reeve; Warren H. Thomas

    1973-01-01

    This paper is concerned with balancing continuous assembly lines with stochastic work elements, The primary problem is defined as follows: “Given an initial balance, a cycle time, normally distributed work element times with given means and variances, and a precedence graph, rearrange the work elements such that the probability of one or more stations exceeding the cycle time is minimized.”

  9. Versatile roof bolt assembly

    SciTech Connect

    Hipkins, E.C. Sr.; Locotos, F.M.

    1987-11-03

    In an anchor bolt assembly of the type used in mine roofs and the like in which the anchor bolt assembly is positioned in a bore hole of a rock formation, where the bolt assembly includes an elongated bolt shaft with an upper end and with a head on a lower end, wherein a quick-setting resin cartridge is positioned in the bore hole above the upper end of the bolt shaft, and wherein the anchor bolt assembly is secured to the rock formation by at least the quick-setting resin, the improvement is described comprising an entrant plug provided at the upper end of the bolt shaft and adapted to rupture the resin cartridge and an elongated helical coil external of and surrounding the bolt shaft. It has a direction of coil for mixing the quick-setting resin and urging the quick-setting resin upwardly toward the upper end while the bolt shaft is rotated in one continuous direction. The helical coil is disposed below the entrant plug and connected to the entrant plug or the bolt shaft and extending a substantial length along the bolt shaft to achieve the mixing.

  10. Uniform Test Assembly

    ERIC Educational Resources Information Center

    Belov, Dmitry I.

    2008-01-01

    In educational practice, a test assembly problem is formulated as a system of inequalities induced by test specifications. Each solution to the system is a test, represented by a 0-1 vector, where each element corresponds to an item included (1) or not included (0) into the test. Therefore, the size of a 0-1 vector equals the number of items "n"…

  11. Beyond the Assembly Line.

    ERIC Educational Resources Information Center

    Weitz, Rebecca; Guild, Todd

    1985-01-01

    Describes how Hughes Aircraft trainers followed four steps in meeting the challenges of a flexible manufacturing environment: needs assessment, design strategy, pilot evaluation, and follow-through. Within this environment, 50 self-paced training products were developed for one of the company's wire and back plane harness assembly departments. (CT)

  12. Rotary shaft sealing assembly

    DOEpatents

    Dietle, Lannie L. (Houston, TX); Schroeder, John E. (Richmond, TX); Kalsi, Manmohan S. (Houston, TX); Alvarez, Patricio D. (Richmond, TX)

    2010-09-21

    A rotary shaft sealing assembly in which a first fluid is partitioned from a second fluid in a housing assembly having a rotary shaft located at least partially within. In one embodiment a lip seal is lubricated and flushed with a pressure-generating seal ring preferably having an angled diverting feature. The pressure-generating seal ring and a hydrodynamic seal may be used to define a lubricant-filled region with each of the seals having hydrodynamic inlets facing the lubricant-filled region. Another aspect of the sealing assembly is having a seal to contain pressurized lubricant while withstanding high rotary speeds. Another rotary shaft sealing assembly embodiment includes a lubricant supply providing a lubricant at an elevated pressure to a region between a lip seal and a hydrodynamic seal with a flow control regulating the flow of lubricant past the lip seal. The hydrodynamic seal may include an energizer element having a modulus of elasticity greater than the modulus of elasticity of a sealing lip of the hydrodynamic seal.

  13. Rotary shaft sealing assembly

    DOEpatents

    Dietle, Lannie L; Schroeder, John E; Kalsi, Manmohan S; Alvarez, Patricio D

    2013-08-13

    A rotary shaft sealing assembly in which a first fluid is partitioned from a second fluid in a housing assembly having a rotary shaft located at least partially within. In one embodiment a lip seal is lubricated and flushed with a pressure-generating seal ring preferably having an angled diverting feature. The pressure-generating seal ring and a hydrodynamic seal may be used to define a lubricant-filled region with each of the seals having hydrodynamic inlets facing the lubricant-filled region. Another aspect of the sealing assembly is having a seal to contain pressurized lubricant while withstanding high rotary speeds. Another rotary shaft sealing assembly embodiment includes a lubricant supply providing a lubricant at an elevated pressure to a region between a lip seal and a hydrodynamic seal with a flow control regulating the flow of lubricant past the lip seal. The hydrodynamic seal may include an energizer element having a modulus of elasticity greater than the modulus of elasticity of a sealing lip of the hydrodynamic seal.

  14. Hybrid assembly line design

    Microsoft Academic Search

    B. Rekiek; A. Delchambre

    2001-01-01

    This paper presents a method to address the multiple objective hybrid assembly line balancing problem. The aim is to assign a set of tasks to stations and select equipment to perform each of them. The goal is to minimize the total cost of the line by integrating design (station space, equipment cost, etc.) and operation issues (cycle time, precedence constraints

  15. Modular fuel cell assembly

    Microsoft Academic Search

    Dyer

    1992-01-01

    This patent describes a modular fuel cell assembly. It comprises n fuel cells, where n is a positive integer having a value of at least 2, each of the cells including a first electrode arrangement and a second electrode arrangement separated by an in contact with a solid-electrolyte body, wherein the first electrode arrangement is permeable to a fuel and

  16. Predicting self-assembly: from empirism to determinism.

    PubMed

    Palma, Carlos-Andres; Cecchini, Marco; Samorì, Paolo

    2012-05-21

    Self-assembly is one of the most important concepts of the 21st century. Strikingly, despite the rational design of molecules for biological and pharmaceutical applications is rather well established, only few are the attempts to formally refine predictions of self-assembly in material science. In the present tutorial review, we encompass some of the most significant efforts towards the systematic study of (thermodynamically stable) self-assembly. We discuss experimental and computer-simulated self-assembly events in hard-matter, soft-matter and higher symmetry architectures under the common framework of partition functions. In this framework, we endeavor to correlate state-of-the-art chemical design, programming and/or engineering of reversible (thermal and chemical equilibrium) self-assembly with knowledge of the underlying partition function landscape in a step towards quantitative predictions and ab initio molecular design. PMID:22430648

  17. 19 CFR 10.16 - Assembly abroad.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...components of the assembly. Example. Diodes are assembled abroad from American-made...foreign origin. After the prefabricated diode components are assembled, the assembled...upon solidification a plastic body for the diode. Upon importation, exemption may...

  18. 19 CFR 10.16 - Assembly abroad.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...components of the assembly. Example. Diodes are assembled abroad from American-made...foreign origin. After the prefabricated diode components are assembled, the assembled...upon solidification a plastic body for the diode. Upon importation, exemption may...

  19. 19 CFR 10.16 - Assembly abroad.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...components of the assembly. Example. Diodes are assembled abroad from American-made...foreign origin. After the prefabricated diode components are assembled, the assembled...upon solidification a plastic body for the diode. Upon importation, exemption may...

  20. Exploring Fabrication: Self-Assembly

    NSDL National Science Digital Library

    2014-06-10

    In this activity, learners participate in several full-body interactive games to model the process of self-assembly in nature and nanotechnology. Through these activities learners assemble into a ring, a capsule, and a snowflake. Learners discover that self-assembly is a process by which molecules and cells form themselves into functional structures. Note: this activity requires at least nine learners.

  1. Wesleyan Student Assembly WSA Meeting

    E-print Network

    Royer, Dana

    circumstances. Question for the assembly: any problems with the current routes? David M: Current blue line, redWesleyan Student Assembly WSA Meeting 12/13/09 President: Michael Pernick (mpernick-your-own-certificate" option? Mike initiates mini-discussion about minors -Discussion cut short #12;Wesleyan Student Assembly 6

  2. Assembly line job sequencing principles

    Microsoft Academic Search

    LAWRENCE D. BURNS; CARLOS F. DAGANZO

    1987-01-01

    Assembly line job sequencing establishes the order in which jobs are processed by an assembly line. This research focuses on job sequencing methods for assembly lines with work stations that receive the same fixed job sequence, are coupled together so that there is no work-in-process storage, and are balanced so that jobs move continuously between them at a constant rate.

  3. Modular nuclear fuel assembly design

    Microsoft Academic Search

    1987-01-01

    A fuel assembly for a nuclear reactor core is described comprising at least two sub-assembly fuel modules, each of the sub-assembly modules containing axially extending fuel rods and comprising: a bottom nozzle module having an associated bottom plate module; a top nozzle module having an associated top plate module; at least one guide tube extending between the top and bottom

  4. An Assembly Funnel Makes Biomolecular Complex Assembly Efficient

    PubMed Central

    Zenk, John; Schulman, Rebecca

    2014-01-01

    Like protein folding and crystallization, the self-assembly of complexes is a fundamental form of biomolecular organization. While the number of methods for creating synthetic complexes is growing rapidly, most require empirical tuning of assembly conditions and/or produce low yields. We use coarse-grained simulations of the assembly kinetics of complexes to identify generic limitations on yields that arise because of the many simultaneous interactions allowed between the components and intermediates of a complex. Efficient assembly occurs when nucleation is fast and growth pathways are few, i.e. when there is an assembly “funnel”. For typical complexes, an assembly funnel occurs in a narrow window of conditions whose location is highly complex specific. However, by redesigning the components this window can be drastically broadened, so that complexes can form quickly across many conditions. The generality of this approach suggests assembly funnel design as a foundational strategy for robust biomolecular complex synthesis. PMID:25360818

  5. Self-assembly of active attractive spheres.

    PubMed

    Prymidis, Vasileios; Sielcken, Harmen; Filion, Laura

    2015-05-20

    We study the self-assembly of a system of self-propelled, Lennard-Jones particles using Brownian dynamics simulations. We examine the state diagrams of the system for different rotational diffusion coefficients of the self-propelled motion of the particles. For fast rotational diffusion, the state diagram exhibits a strong similarity to that of the equilibrium Lennard-Jones fluid. As we decrease the rotational diffusion coefficient, the state diagram is slowly transformed. Specifically, the liquid-gas coexistence region is gradually replaced by a highly dynamic percolating network state. We find significant local alignment of the particles in the percolating network state despite the absence of aligning interactions, and propose a simple mechanism to justify the formation of this novel state. PMID:25866369

  6. Special test equipment and fixturing for MSAT reflector assembly alignment

    NASA Technical Reports Server (NTRS)

    Young, Jeffrey A.; Zinn, Michael R.; Mccarten, David R.

    1994-01-01

    The MSAT Reflector Assembly is a state of the art subsystem for Mobile Satellite (MSAT), a geosynchronous-based commercial mobile telecommunication satellite program serving North America. The Reflector Assembly consisted of a deployable, three-hinge, folding-segment Boom, deployable 5.7 x 5.3-meter 16-rib Wrap-Rib Reflector, and a Reflector Pointing Mechanism (RPM). The MSAT spacecraft was based on a Hughes HS601 spacecraft bus carrying two Reflector Assemblies independently dedicated for L-band transmit and receive operations. Lockheed Missiles and Space Company (LMSC) designed and built the Reflector Assembly for MSAT under contract to SPAR Aerospace Ltd. Two MSAT satellites were built jointly by SPAR Aerospace Ltd. and Hughes Space and Communications Co. for this program, the first scheduled for launch in 1994. When scaled for wavelength, the assembly and alignment requirements for the Reflector Assembly were in many instances equivalent to or exceeded that of a diffraction-limited visible light optical system. Combined with logistical constraints inherent to large, compliant, lightweight structures; 'bolt-on' alignment; and remote, indirect spacecraft access; the technical challenges were formidable. This document describes the alignment methods, the special test equipment, and fixturing for Reflector Assembly assembly and alignment.

  7. Autonomous Mechanical Assembly on the Space Shuttle: An Overview

    NASA Technical Reports Server (NTRS)

    Raibert, M. H.

    1979-01-01

    The space shuttle will be equipped with a pair of 50 ft. manipulators used to handle payloads and to perform mechanical assembly operations. Although current plans call for these manipulators to be operated by a human teleoperator. The possibility of using results from robotics and machine intelligence to automate this shuttle assembly system was investigated. The major components of an autonomous mechanical assembly system are examined, along with the technology base upon which they depend. The state of the art in advanced automation is also assessed.

  8. New Approaches for Antiviral Targeting of HIV Assembly

    PubMed Central

    Prevelige, Peter E.

    2011-01-01

    The pressing need to develop antivirals active against resistant strains of HIV-1 has led to efforts to target steps in the virus life cycle other than reverse transcription and Gag proteolysis. Among those steps are entry, integration, and assembly and/or maturation. Advances in understanding the structural biology of both the immature and mature forms of the HIV capsid have made it possible to design or discover small molecules and peptides which interfere with both assembly and maturation. In this article we review the current state of the art in assembly and maturation inhibitors. PMID:21762804

  9. Mechanical seal assembly

    DOEpatents

    Kotlyar, Oleg M. (Salt Lake City, UT)

    2001-01-01

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transferring it to the mechanical diode.

  10. Hearing Aid Assembly

    NASA Technical Reports Server (NTRS)

    Grugel, Richard N. (Inventor)

    2002-01-01

    Progress in hearing aids has come a long way. Yet despite such progress hearing aids are not the perfect answer to many hearing problems. Some adult ears cannot accommodate tightly fitting hearing aids. Mouth movements such as chewing, talking, and athletic or other active endeavors also lead to loosely fitting ear molds. It is well accepted that loosely fitting hearing aids are the cause of feedback noise. Since feedback noise is the most common complaint of hearing aid wearers it has been the subject of various patents. Herein a hearing aid assembly is provided eliminating feedback noise. The assembly includes the combination of a hearing aid with a headset developed to constrict feedback noise.

  11. Mechanical Seal Assembly

    SciTech Connect

    Kotlyar, Oleg M.

    1999-06-18

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transferring it to the mechanical diode.

  12. Vacuum breaker valve assembly

    DOEpatents

    Thompson, J.L.; Upton, H.A.

    1999-04-27

    Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening. 1 fig.

  13. Supramolecular Assembly of Biomolecules

    NASA Astrophysics Data System (ADS)

    Safinya, Cyrus R.

    2004-03-01

    At present there is a surge in interest in biophysical research in elucidating collective interactions between cellular proteins and associated biomolecules leading to supramolecular structures, with the ultimate goal of relating structure to function. The nerve cell cytoskeleton, provides a rich example of a network of interacting neurofilaments, microtubules, both single and bundles, and filamentous actin, where the structure and structure-function correlations remain poorly understood. We present synchrotron x-ray diffraction, electron microscopy, and optical imaging data, in reconstituted systems of microtubules and neurofilaments from bovine brain and spinal cord, which reveal supramolecular assemblies of bundles, networks, and kinetically driven structural transitions from bundles to raft-like assemblies of tubulin rings.

  14. Mechanical seal assembly

    DOEpatents

    Kotlyar, Oleg M. (Salt Lake City, UT)

    2002-01-01

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transfering it to the mechanical diode.

  15. Ingestion resistant seal assembly

    DOEpatents

    Little, David A. (Chuluota, FL)

    2011-12-13

    A seal assembly limits gas leakage from a hot gas path to one or more disc cavities in a gas turbine engine. The seal assembly includes a seal apparatus associated with a blade structure including a row of airfoils. The seal apparatus includes an annular inner shroud associated with adjacent stationary components, a wing member, and a first wing flange. The wing member extends axially from the blade structure toward the annular inner shroud. The first wing flange extends radially outwardly from the wing member toward the annular inner shroud. A plurality of regions including one or more recirculation zones are defined between the blade structure and the annular inner shroud that recirculate working gas therein back toward the hot gas path.

  16. Turbine seal assembly

    DOEpatents

    Little, David A.

    2013-04-16

    A seal assembly that limits gas leakage from a hot gas path to one or more disc cavities in a turbine engine. The seal assembly includes a seal apparatus that limits gas leakage from the hot gas path to a respective one of the disc cavities. The seal apparatus comprises a plurality of blade members rotatable with a blade structure. The blade members are associated with the blade structure and extend toward adjacent stationary components. Each blade member includes a leading edge and a trailing edge, the leading edge of each blade member being located circumferentially in front of the blade member's corresponding trailing edge in a direction of rotation of the turbine rotor. The blade members are arranged such that a space having a component in a circumferential direction is defined between adjacent circumferentially spaced blade members.

  17. Vacuum breaker valve assembly

    DOEpatents

    Thompson, Jeffrey L. (San Jose, CA); Upton, Hubert Allen (Morgan Hill, CA)

    1999-04-27

    Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening.

  18. Pull rod assembly

    DOEpatents

    Cioletti, O.C.

    1988-04-21

    A pull rod assembly comprising a pull rod having three peripheral grooves, a piston device including an adaptor ring and a seal ring, said piston device being mounted on the pull rod by a split ring retainer situated in one groove and extending into an interior groove in the adaptor and a resilient split ring retained in another groove and positioned to engage the piston device and to retain the seal on its adaptor.

  19. Nanoparticle assemblies as memristors.

    PubMed

    Kim, Tae Hee; Jang, Eun Young; Lee, Nyun Jong; Choi, Deung Jang; Lee, Kyung-Jin; Jang, Jung-tak; Choi, Jin-sil; Moon, Seung Ho; Cheon, Jinwoo

    2009-06-01

    Recently a memristor ( Chua, L. O. IEEE Trans. Circuit Theory 1971 , 18 , 507 ), the fourth fundamental passive circuit element, has been demonstrated as thin film device operations ( Strukov, D. B.; Snider, G. S.; Stewart, D. R.; Williams, R. S. Nature (London) 2008 , 453 , 80 ; Yang, J. J.; Pickett. M. D.; Li, X.; Ohlberg, D. A. A.; Stewart, D. R.; Williams, R. S. Nat. Nanotechnol. 2008 , 3 , 429 ). A new addition to the memristor family can be nanoparticle assemblies consisting of an infinite number of monodispersed, crystalline magnetite (Fe(3)O(4)) particles. Assembly of nanoparticles that have sizes below 10 nm, exhibits at room temperature a voltage-current hysteresis with an abrupt and large bipolar resistance switching (R(OFF)/R(ON) approximately 20). Interestingly, observed behavior could be interpreted by adopting an extended memristor model that combines both a time-dependent resistance and a time-dependent capacitance. We also observed that such behavior is not restricted to magnetites; it is a general property of nanoparticle assemblies as it was consistently observed in different types of spinel structured nanoparticles with different sizes and compositions. Further investigation into this new nanoassembly system will be of importance to the realization of the next generation nanodevices with potential advantages of simpler and inexpensive device fabrications. PMID:19408928

  20. Saddle clamp assembly

    NASA Astrophysics Data System (ADS)

    Belrose, Charles R.

    1994-01-01

    A saddle clamp assembly is presented. The assembly is comprised of a hollow cylindrical body centered about a longitudinal axis and being diametrically split into semicircular top and bottom sections. Each section has a pair of connection flanges, at opposite ends, that project radially outward. A pair of bolts are retained on the top section flanges and are threadable into nuts retained on the bottom section flanges. A base member is anchored to a central underside portion of the bottom clamp body section and has a pair of connection tabs positioned beneath the bottom clamp body section connection flanges on opposite sides of the clamp axis. A pair of bolts are retained on the base member connection tabs and are threadable into a pair of nuts retainable on a support structure. The connection tab and connection flanges on each side of the clamp body are axially offset in a manner permitting downward installation/removable tool access to the lower bolts past the connection flanges. An elongated retention tether is used to connect the top clamp body section to the balance of the clamp assembly. This prevents loss of the top clamp body section when it is removed from the bottom clamp body section.

  1. Saddle clamp assembly

    NASA Astrophysics Data System (ADS)

    Belrose, Charles R.

    1992-11-01

    A saddle clamp assembly is presented. The assembly is comprised of a hollow cylindrical body centered about a longitudinal axis and being diametrically split into semicircular top and bottom sections. Each section has a pair of connection flanges, at opposite ends, that project radially outward. A pair of bolts are retained on the top section flanges and are threadable into nuts retained on the bottom section flanges. A base member is anchored to a central underside portion of the bottom clamp body section and has a pair of connection tabs positioned beneath the bottom clamp body section connection flanges on opposite sides of the clamp axis. A pair of bolts are retained on the base member connection tabs and are threadable into a pair of nuts retainable on a support structure. The connection tab and connection flanges on each side of the clamp body are axially offset in a manner permitting downward installation/removable tool access to the lower bolts past the connection flanges. An elongated retention tether is used to connect the top clamp body section to the balance of the clamp assembly. This prevents loss of the top clamp body section when it is removed from the bottom clamp body section.

  2. Retractable Visual Indicator Assembly

    NASA Technical Reports Server (NTRS)

    Hackler, George R. (Inventor); Gamboa, Ronald J. (Inventor); Dominquez, Victor (Inventor)

    1998-01-01

    A retractable indicator assembly may be mounted on a container which transmits air through the container and removes deleterious gases with an activated charcoal medium in the container. The assembly includes: an elongate indicator housing has a chamber therein; a male adaptor with an external threads is used for sealing engagement with the container; a plug located at the upper end of the housing; a housing that includes a transparent wall portion for viewing at least a portion of the chamber; a litmus indicator, moveable by a retractable rod from a retracted position within the container to an extended position within the chamber of the housing; and an outer housing that is secured to the upper end of the rod, and protects the indicator housing while the litmus indicator is in its normally retracted position. The assembly may be manually manipulated between its extended position wherein the litmus indicator may be viewed through the transparent wall of the indicator housing, and a retracted position wherein the outer housing encloses the indicator housing and engages the exterior of the container.

  3. Development of a System for BWR Fuel Assembly Axial Optimization

    SciTech Connect

    Francois, Juan Luis; Cortes, Alejandro

    1999-06-06

    We present the preliminary results of an ongoing research project related to the development of a system for boiling water reactor (BWR) fuel assembly (FA) axial design optimization. The OPTEN system is based on a direct search algorithm, the flexible tolerance method (FTM), and uses the Core-Master PRESTO (CM-PRESTO) three-dimensional steady-state simulator code to evaluate the objective function and the constraints. The feasibility of this methodology is investigated for a typical BWR fuel assembly.

  4. Installation and assembly device and method of using

    DOEpatents

    Kolsun, George J. (Pittsburgh, PA)

    1997-01-01

    An installation and assembly device for aligning a first member such as a pump impeller with a second member such as an inlet nozzle of an impeller pump. The installation and assembly device includes a sleeve slideable within the inlet nozzle and a vertical positioning assembly which has a contact member that is extendable out away from the sleeve so as to vertically position the sleeve on a shoulder of the inlet nozzle and to present an upper contact surface spaced a certain distance from the shoulder to provide the desired vertical spacing with respect to the impeller contacting the upper contact surface. The vertical positioning assembly is retractable so as to allow for removal of the sleeve through the nozzle when installation and assembly are completed. The alignment device also includes a radial alignment assembly supported by the sleeve and adjustable to an expanded state for contacting and spacing the interior surface of the impeller a certain distance from the sleeve and hence a certain distance from the inlet nozzle. The radial alignment device being adjustable from a retracted removal state to an expanded state and also being adjustable to fine tune the spacing of the impeller from the sleeve. The radial alignment device also preferably includes members that can be used to releasably secure the sleeve to the impeller.

  5. Approach to Dynamic Assembling of Individualized Learning Paths

    ERIC Educational Resources Information Center

    Lubchak, Vladimir; Kupenko, Olena; Kuzikov, Borys

    2012-01-01

    E-learning students are generally heterogeneous and have different capabilities knowledge base and needs. The aim of the Sumy State University (SSU) e-learning system project is to cater to these individual needs by assembling individual learning path. This paper shows current situation with e-learning in Ukraine, state-of-art of development of…

  6. Conformational Changes in the Hepatitis B Virus Core Protein Are Consistent with a Role for Allostery in Virus Assembly

    SciTech Connect

    Packianathan, Charles; Katen, Sarah P.; Dann, III, Charles E.; Zlotnick, Adam (Indiana)

    2010-01-12

    In infected cells, virus components must be organized at the right place and time to ensure assembly of infectious virions. From a different perspective, assembly must be prevented until all components are available. Hypothetically, this can be achieved by allosterically controlling assembly. Consistent with this hypothesis, here we show that the structure of the hepatitis B virus (HBV) core protein dimer, which can spontaneously self-assemble, is incompatible with capsid assembly. Systematic differences between core protein dimer and capsid conformations demonstrate linkage between the intradimer interface and interdimer contact surface. These structures also provide explanations for the capsid-dimer selectivity of some antibodies and the activities of assembly effectors. Solution studies suggest that the assembly-inactive state is more accurately an ensemble of conformations. Simulations show that allostery supports controlled assembly and results in capsids that are resistant to dissociation. We propose that allostery, as demonstrated in HBV, is common to most self-assembling viruses.

  7. Anisotropic Self-Assembly of Nanoparticle Amphiphiles

    NASA Astrophysics Data System (ADS)

    Kumar, Sanat

    2009-03-01

    It is easy to understand the self-assembly of particles having anisotropic shapes or interactions, such as Co nanoparticles or proteins, into highly extended structures. However, there is no experimentally established strategy for creating anisotropic structures from common spherical nanoparticles. We demonstrate that spherical nanoparticles, uniformly grafted with macromolecules, robustly self-assemble into a range of anisotropic superstructures when they are dispersed in the corresponding homopolymer matrix. This phenomenon is driven by the microphase separation between the inorganic nanoparticles and the (organic) polymeric chains grafted to their surfaces in a fashion similar to block copolymers. This microphase separation driven particle self-assembly provides a unique means of controlling the global nanoparticle dispersion state in polymer nanocomposites. The relationship between the state of particle dispersion and nanocomposite properties can thus be critically examined, and in particular we focus on the mechanical reinforcement afforded when particles are added to polymers. Grafted nanoparticles are thus versatile building blocks for creating tunable and functional particle superstructures with significant practical applications. With Pinar Akcora, Hongjun Liu, Yu Li, Brian Benicewicz, Linda Schadler, Thanos Panagiotopoulos, Jack Douglas, P. Thiyagarajan and Ralph Colby.

  8. Precision Robotic Assembly Machine

    ScienceCinema

    None

    2010-09-01

    The world's largest laser system is the National Ignition Facility (NIF), located at Lawrence Livermore National Laboratory. NIF's 192 laser beams are amplified to extremely high energy, and then focused onto a tiny target about the size of a BB, containing frozen hydrogen gas. The target must be perfectly machined to incredibly demanding specifications. The Laboratory's scientists and engineers have developed a device called the "Precision Robotic Assembly Machine" for this purpose. Its unique design won a prestigious R&D-100 award from R&D Magazine.

  9. Removable feedwater sparger assembly

    DOEpatents

    Challberg, R.C.

    1994-10-04

    A removable feedwater sparger assembly includes a sparger having an inlet pipe disposed in flow communication with the outlet end of a supply pipe. A tubular coupling includes an annular band fixedly joined to the sparger inlet pipe and a plurality of fingers extending from the band which are removably joined to a retention flange extending from the supply pipe for maintaining the sparger inlet pipe in flow communication with the supply pipe. The fingers are elastically deflectable for allowing engagement of the sparger inlet pipe with the supply pipe and for disengagement therewith. 8 figs.

  10. BIOCHEMISTRY: Dicey Assemblies

    NSDL National Science Digital Library

    Joël Janin (Institut de Biochimie et Biophysique Moléculaire et Cellulaire; Yeast Structural Genomics)

    2008-01-11

    Access to the article is free, however registration and sign-in are required. Site-directed mutagenesis allows the symmetry of protein assemblies to be directed in a systematic manner. More than 40 years ago, Jacques Monod and co-workers developed the theory of allostery that explains how the activity of proteins can be efficiently regulated. The quaternary structure allows proteins to have symmetries that play a central role in allostery. Grueninger et al. prove that this symmetry can be manipulated by site-directed mutagenesis. Their experiments confirm some of the basic arguments made by Monod et al.

  11. Self-Assembling Dessert Toppings

    NSDL National Science Digital Library

    2012-12-27

    This is an activity (located on page 3 of the PDF) about self-assembly, the ability of molecules to assemble themselves according to certain rules. Learners will use food-grade components to create delicious dessert topping-filled gel capsules, macroscale relatives of the capsules nanoscientists make in a lab to carry medicine to targeted cells of the body. Relates to linked video, DragonflyTV Nano: Self-Assembly.

  12. Fuel Assembly Nonlinear Dynamic Model

    SciTech Connect

    Shah, S.J.; Brenneman, B. [Framatome ANP, P.O. Box 10935 P.O. Box 10935, Lynchburg, VA-24506-0935 (United States)

    2002-07-01

    Fuel assembly finite-element dynamic models are developed to perform the core seismic analysis. The fuel assembly is modeled by a single vertical beam, which represents the cross-sectional inertias of the fuel rods, guide thimbles and instrument thimble, and a series of rotational springs. The rotational springs are located at the intermediate spacer grid locations. Benchmarking to fuel assembly natural frequencies determined by testing is accomplished by adjusting the moment of inertia and the grid rotational stiffness to find their effective values. Most often these models are linear and are appropriate for the small amplitude stiffness representation of the fuel assembly. Large deflection problems are approximated by choosing a fuel assembly stiffness value appropriate to the average deflection range. Some loss of accuracy will naturally result from this approach. This paper presents a nonlinear model to approximate the hysteresis and free vibration response for large amplitudes fuel assembly motion. The force required to impose the initial displacement (pluck) and the free vibration responses are used to compare the nonlinear model's behavior with the test data. This model correctly predicts fuel assembly deflection shapes as a function of axial position for various lateral loads for several fuel assembly designs. Displacement hysteresis is primarily due to fuel assembly to grid slippage, which is a strong function of grid preload. 'Tight' and 'relaxed' prototypes were tested to account for grid preload effect. The model correctly analyzes the grid preload effect. A nonlinear fuel assembly model provides better matching of grid impact loads determined by fuel assembly lateral impact testing and also provides better matching of all of the initial conditions (initial deflection, initial force, initial energy and impact velocity). In this test, the fuel assembly impacts a test wall to determine grid internal stiffness. This value is used in the core model for seismic analyses. (authors)

  13. Methanation assembly using multiple reactors

    DOEpatents

    Jahnke, Fred C.; Parab, Sanjay C.

    2007-07-24

    A methanation assembly for use with a water supply and a gas supply containing gas to be methanated in which a reactor assembly has a plurality of methanation reactors each for methanating gas input to the assembly and a gas delivery and cooling assembly adapted to deliver gas from the gas supply to each of said methanation reactors and to combine water from the water supply with the output of each methanation reactor being conveyed to a next methanation reactor and carry the mixture to such next methanation reactor.

  14. Multi-position photovoltaic assembly

    DOEpatents

    Dinwoodie, Thomas L. (Piedmont, CA)

    2003-03-18

    The invention is directed to a PV assembly, for use on a support surface, comprising a base, a PV module, a multi-position module support assembly, securing the module to the base at shipping and inclined-use angles, a deflector, a multi-position deflector support securing the deflector to the base at deflector shipping and deflector inclined-use angles, the module and deflector having opposed edges defining a gap therebetween. The invention permits transport of the PV assemblies in a relatively compact form, thus lowering shipping costs, while facilitating installation of the PV assemblies with the PV module at the proper inclination.

  15. Nonlinear Modeling by Assembling Piecewise Linear Models

    NASA Technical Reports Server (NTRS)

    Yao, Weigang; Liou, Meng-Sing

    2013-01-01

    To preserve nonlinearity of a full order system over a parameters range of interest, we propose a simple modeling approach by assembling a set of piecewise local solutions, including the first-order Taylor series terms expanded about some sampling states. The work by Rewienski and White inspired our use of piecewise linear local solutions. The assembly of these local approximations is accomplished by assigning nonlinear weights, through radial basis functions in this study. The efficacy of the proposed procedure is validated for a two-dimensional airfoil moving at different Mach numbers and pitching motions, under which the flow exhibits prominent nonlinear behaviors. All results confirm that our nonlinear model is accurate and stable for predicting not only aerodynamic forces but also detailed flowfields. Moreover, the model is robustness-accurate for inputs considerably different from the base trajectory in form and magnitude. This modeling preserves nonlinearity of the problems considered in a rather simple and accurate manner.

  16. Microchannel heat sink assembly

    DOEpatents

    Bonde, Wayne L. (Livermore, CA); Contolini, Robert J. (Pleasanton, CA)

    1992-01-01

    The present invention provides a microchannel heat sink with a thermal range from cryogenic temperatures to several hundred degrees centigrade. The heat sink can be used with a variety of fluids, such as cryogenic or corrosive fluids, and can be operated at a high pressure. The heat sink comprises a microchannel layer preferably formed of silicon, and a manifold layer preferably formed of glass. The manifold layer comprises an inlet groove and outlet groove which define an inlet manifold and an outlet manifold. The inlet manifold delivers coolant to the inlet section of the microchannels, and the outlet manifold receives coolant from the outlet section of the microchannels. In one embodiment, the manifold layer comprises an inlet hole extending through the manifold layer to the inlet manifold, and an outlet hole extending through the manifold layer to the outlet manifold. Coolant is supplied to the heat sink through a conduit assembly connected to the heat sink. A resilient seal, such as a gasket or an O-ring, is disposed between the conduit and the hole in the heat sink in order to provide a watetight seal. In other embodiments, the conduit assembly may comprise a metal tube which is connected to the heat sink by a soft solder. In still other embodiments, the heat sink may comprise inlet and outlet nipples. The present invention has application in supercomputers, integrated circuits and other electronic devices, and is suitable for cooling materials to superconducting temperatures.

  17. Two speed axle assembly

    SciTech Connect

    Heine, C.F.; Krisher, J.A.; Pifer, R.L.

    1988-10-04

    This patent describes a two speed axle assembly comprising an input sun gear, an output sun gear, a plant carrier mounted for rotation about the input and output sun gears, at least one compound planetary gear rotatably mounted on the planet carrier and drivingly connected to the input sun gear and the output sun gear, first clutch means for selectively locking the planet carrier relative to the input sun gear for rotation therewith including means normally loading the first clutch means whereby the planet carrier rotates the input sun gear, second clutch means for alternatively locking the planet carrier against rotation whereby the compound planet gear rotates on the planet carrier in response to rotation of the input sun gear, and inflatable bladder means adapted when selectively inflated to load the second clutch means and simultaneously unload the normally loaded first clutch means whereby the planet carrier is unlocked relative to the input sun gear and locked against rotation, including means selectively supplying hydraulic fluid under pressure to the bladder means, means supplying hydraulic fluid comprising accumulator means, pump means remote from the axle assembly for pressurizing the hydraulic fluid and maintaining a supply of the fluid under at least a minimum pressure in the accumulator means, and valve means for selectively admitting the pressurized fluid from the accumulator means to the bladder means to inflate the bladder means and relieving the pressure to deflate the bladder means.

  18. Counterbalanced refueling arm assembly

    SciTech Connect

    Fournier, P.J.E.; Reinker, J.F., Jr.

    1990-02-06

    This patent describes a counter balanced refueling arm. It comprises: a supporting platform, wheels supporting the platform, an outer caster assembly. The wheel, a first swivel joint mounted on the outboard caster assembly having a substantially vertical axis of rotation, an inlet and an outlet defined on the joint, a fuel supply conduit communicating with the joint inlet, a second swivel joint mounted on the platform having a substantially horizontal axis of rotation, an inlet and an outlet, a rigid conduit interconnecting the first joint outlet with the second joint inlet establishing communication between the first and second joint, a substantially rigid arm conduit having an axis, an inner end affixed to and communicating with the second joint outlet and an outer end. The arm conduit being pivoted about the second joint axis within a substantially vertical plane, a first elbow swivel coupling having an inlet connected to the arm conduit outer end, an outlet and an axis of rotation transverse to the arm conduit axis, a second elbow swivel coupling having an inlet connected to the first coupling outlet, an outlet and an axis of rotation transverse to aid first coupling axis, a third elbow swivel coupling having an inlet connected to the second coupling outlet, an outlet and an axis of rotation transverse to the coupling axis, and a nozzle connected to the third coupling outlet.

  19. Microtopographical assembly of cardiomyocytes.

    PubMed

    Patel, Anuj A; Desai, Tejal A; Kumar, Sanjay

    2011-10-01

    One of the central challenges in cardiac tissue engineering is the control of the assembly and organization of functional cardiac tissue. Maintenance of a three-dimensional tissue architecture is key to myocardial function in vivo, and a variety of studies hint that provision of topological cues within scaffolds can facilitate the engineering of functional myocardial tissue by promoting this architecture. To explore this possibility in an isolated and well-defined fashion, we have designed scaffolds of polydimethylsiloxane (PDMS) with microtopographic pillars ("micropegs") to provide cells with defined structures with which to interact in three dimensions. We show that these surfaces permit HL-1 cardiomyocytes to grow, form myofibrillar structures and cell-cell adhesions, and beat spontaneously. Additionally, the cells and their nuclei interact with the full length of the micropegs, indicating that the micropegs promote a three-dimensional cytoarchitecture in the context of a two-dimensional scaffold. We also show that the number of cells interacting with a micropeg can be controlled by manipulating incubation time, micropeg spatial arrangement, or micropeg diameter. Western blots reveal that the expression of the junctional markers N-cadherin and connexin 43 is upregulated in the presence of specific arrangements of micropegs, suggesting that micropegs can enhance cardiomyocyte function. Together, these data show that microtopography can be used to provide three-dimensional adhesion and control the assembly of functional cardiac tissue on a two-dimensional surface. PMID:21863181

  20. Bottom head assembly

    DOEpatents

    Fife, Alex Blair (San Jose, CA)

    1998-01-01

    A bottom head dome assembly which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome is described. The bottom head dome has a plurality of openings extending therethrough. The liner also has a plurality of openings extending therethrough, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending therethrough, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner. In one embodiment, each support shim includes a support stub having a bore therethrough, and each support stub bore aligns with a respective bottom head dome opening.

  1. PROCESS & MANUFACTURING ENGINEERING THE ASSEMBLY LINE

    E-print Network

    Provancher, William

    PROCESS & MANUFACTURING ENGINEERING THE ASSEMBLY LINE #12;What is an Assembly Line? Manufacturing is carefully planned to create a product much faster than handcrafted products. #12;Best Known Assembly Line Moving assembly line (like in I Love Lucy clip). Moving assembly line was instituted by the Ford Motor

  2. Method and apparatus for assembling a permanent magnet pole assembly

    SciTech Connect

    Carl, Jr., Ralph James (Clifton Park, NY); Bagepalli, Bharat Sampathkumaran (Niskayuna, NY); Jansen, Patrick Lee (Scotia, NY); Dawson, Richard Nils (Voorheesville, NY); Qu, Ronghai (Clifton Park, NY); Avanesov, Mikhail Avramovich (Moscow, RU)

    2009-08-11

    A pole assembly for a rotor, the pole assembly includes a permanent magnet pole including at least one permanent magnet block, a plurality of laminations including a pole cap mechanically coupled to the pole, and a plurality of laminations including a base plate mechanically coupled to the pole.

  3. Molecular mechanism of photosystem I assembly in oxygenic organisms.

    PubMed

    Yang, Huixia; Liu, Jun; Wen, Xiaogang; Lu, Congming

    2015-09-01

    Photosystem I, an integral membrane and multi-subunit complex, catalyzes the oxidation of plastocyanin and the reduction of ferredoxin by absorbed light energy. Photosystem I participates in photosynthetic acclimation processes by being involved in cyclic electron transfer and state transitions for sustaining efficient photosynthesis. The photosystem I complex is highly conserved from cyanobacteria to higher plants and contains the light-harvesting complex and the reaction center complex. The assembly of the photosystem I complex is highly complicated and involves the concerted assembly of multiple subunits and hundreds of cofactors. A suite of regulatory factors for the assembly of photosystem I subunits and cofactors have been identified that constitute an integrative network regulating PSI accumulation. This review aims to discuss recent findings in the field relating to how the photosystem I complex is assembled in oxygenic organisms. This article is part of a Special Issue entitled: Chloroplast Biogenesis. PMID:25582571

  4. Structure, dynamics, assembly, and evolution of protein complexes.

    PubMed

    Marsh, Joseph A; Teichmann, Sarah A

    2015-06-01

    The assembly of individual proteins into functional complexes is fundamental to nearly all biological processes. In recent decades, many thousands of homomeric and heteromeric protein complex structures have been determined, greatly improving our understanding of the fundamental principles that control symmetric and asymmetric quaternary structure organization. Furthermore, our conception of protein complexes has moved beyond static representations to include dynamic aspects of quaternary structure, including conformational changes upon binding, multistep ordered assembly pathways, and structural fluctuations occurring within fully assembled complexes. Finally, major advances have been made in our understanding of protein complex evolution, both in reconstructing evolutionary histories of specific complexes and in elucidating general mechanisms that explain how quaternary structure tends to evolve. The evolution of quaternary structure occurs via changes in self-assembly state or through the gain or loss of protein subunits, and these processes can be driven by both adaptive and nonadaptive influences. PMID:25494300

  5. AND/OR graph representation of assembly plans

    NASA Technical Reports Server (NTRS)

    Homem De Mello, Luiz S.; Sanderson, Arthur C.

    1990-01-01

    A compact representation of all possible assembly plans of a product using AND/OR graphs is presented as a basis for efficient planning algorithms that allow an intelligent robot to pick a course of action according to instantaneous conditions. The AND/OR graph is equivalent to a state transition graph but requires fewer nodes and simplifies the search for feasible plans. Three applications are discussed: (1) the preselection of the best assembly plan, (2) the recovery from execution errors, and (3) the opportunistic scheduling of tasks. An example of an assembly with four parts illustrates the use of the AND/OR graph representation in assembly-plan preselection, based on the weighting of operations according to complexity of manipulation and stability of subassemblies. A hypothetical error situation is discussed to show how a bottom-up search of the AND/OR graph leads to an efficient recovery.

  6. Assembling thefacebook: Using heterogeneity to understand online social network assembly

    E-print Network

    Jacobs, Abigail Z; Ugander, Johan; Clauset, Aaron

    2015-01-01

    Online social networks represent a popular and highly diverse class of social media systems. Despite this variety, each of these systems undergoes a general process of online social network assembly, which represents the complicated and heterogeneous changes that transform newly born systems into mature platforms. However, little is known about this process. For example, how much of a network's assembly is driven by simple growth? How does a network's structure change as it matures? How does network structure vary with adoption rates and user heterogeneity, and do these properties play different roles at different points in the assembly? We investigate these and other questions using a unique dataset of online connections among the roughly one million users at the first 100 colleges admitted to Facebook, captured just 20 months after its launch. We first show that different vintages and adoption rates across this population of networks reveal temporal dynamics of the assembly process, and that assembly is onl...

  7. 19 CFR 10.26 - Articles assembled or processed in a beneficiary country in whole of U.S. components or...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...assembled in a beneficiary country from textile components cut to shape in the United...assembled in a beneficiary country from textile components cut to shape in the United...States. (a) No article (except a textile article, apparel article,...

  8. Unification of the a priori inconsistencies checking among assembly constraints in assembly sequence planning

    E-print Network

    Paris-Sud XI, Université de

    generation is an important problem in assembly line design. A good assembly sequence can help to reduce) is to determine the arrangement of assembly operations on the assembly line. Generally, ASP consists of two major1 Unification of the a priori inconsistencies checking among assembly constraints in assembly

  9. A Virtual Assembly Design Environment

    Microsoft Academic Search

    Sankar Jayaram; Yong Wang; Uma Jayaram; Kevin W. Lyons; Peter Hart

    1999-01-01

    The Virtual Assembly Design Environment (VADE) is a Virtual Reality (VR)-based engineering application that allows engineers to evaluate, analyze, and plan the assembly of mechanical systems. This system focuses on utilizing an immersive, virtual environment tightly coupled with commercial computer aided design (CAD) systems. Salient features of VADE include: 1) data integration (two-way) with a parametric CAD system, 2) realistic

  10. Wesleyan Student Assembly WSA Meeting

    E-print Network

    Royer, Dana

    Wesleyan Student Assembly WSA Meeting 02/14/10 President: Michael Pernick (mpernick open forum was closed 4) Agenda Item #1: Green Fund By-Laws Document with edits was emailed to Assembly of interest. Josh: Hard line to draw. Sees Charlie's point but also sees this as a more collaborative process

  11. IFAS FACULTY ASSEMBLY DRAFT MINUTES

    E-print Network

    Jawitz, James W.

    IFAS FACULTY ASSEMBLY DRAFT MINUTES NOVEMBER 27, 2012 1:00 ­ 3:00 PM G001 MCCARTY D ROLL CALLTH MEETING MINUTES Motion: George O'Connor, 2nd : Steve Futch Approved. ASSEMBLY CHAIR REPORT ­ ART meeting COMMITTEE REPORTS PWC ­ GENE MCAVOY - Opened line of communication with Jim Maruniak to inquire

  12. The Bicycle Assembly Line Game

    ERIC Educational Resources Information Center

    Klotz, Dorothy

    2011-01-01

    "The Bicycle Assembly Line Game" is a team-based, in-class activity that helps students develop a basic understanding of continuously operating processes. Each team of 7-10 students selects one of seven prefigured bicycle assembly lines to operate. The lines are run in real-time, and the team that operates the line that yields the…

  13. Solar cell module assembly jig

    Microsoft Academic Search

    H. W. Ofarrell

    1966-01-01

    The invention relates to the manufacture of solar cell modules and more particularly to a jig for assembling, positioning and maintaining the components under resilient pressure, while the entire assembly and the jig is subjected to heat for simultaneously soldering all of the various circuit connections; as well as structurally bonding the layers into a strong light weight structure which

  14. Upgraded Fuel Assemblies for BWRs

    SciTech Connect

    Garner, N.L. [AREVA NP Inc., 2101 Horn Rapids Road, Richland, WA 99352 (United States); Rentmeister, T.; Lippert, H.J. [AREVA NP GmbH, Bunsenstrasse43, 91058 Erlangen (Germany); Mollard, P. [AREVA NP 10, Rue Juliette Recamier 69456 Lyon Cedex 06 (France)

    2007-07-01

    Established with engineering and manufacturing operations in the US and Europe, AREVA NP has been and is supplying nuclear fuel assemblies and associated core components to light water reactors worldwide, representing today more than 170,000 fuel assemblies on the world market and more than 56,000 fuel assemblies for BWR plants. Since first delivered in 1992, ATRIUM{sup TM}(1)10 fuel assemblies have now been supplied to a total of 28 BWR plants in the US, Europe, and Asia resulting in an operating experience over 16 000 fuel assemblies. In the spring of 2001, a BWR record burnup of 71 MWd/kgU was reached by four lead fuel assemblies after eight operating cycles. More recently, ATRIUM 10XP and ATRIUM 10XM fuel assemblies featuring changes in their characteristics and exhibiting upgraded behavior have been delivered to several utilities worldwide. This success story has been made possible thanks to a continuous improvement process with the aim of further upgrading BWR fuel assembly performance and reliability. An overview is given on current AREVA advanced BWR fuel supply regarding: - advanced designs to tailor product selection to specific operating strategies; - performance capabilities of each advanced design option; - testing and operational experience for these advanced designs; - upgraded features available for inclusion with advanced designs. (authors)

  15. Ground-state interband transition of individual self-assembled InAs\\/Al0.6Ga0.4As quantum dots observed by scanning-tunneling-microscope light-emission spectroscopy

    Microsoft Academic Search

    T. Tsuruoka; Y. Ohizumi; S. Ushioda

    2004-01-01

    We have investigated the optical transitions in individual self-assembled InAs\\/Al0.6Ga0.4As quantum dots (QDs) by means of scanning-tunneling-microscope (STM) light-emission spectroscopy. Localized bright features were observed in the spectrally resolved light intensity images measured by injecting electrons from the STM tip. The light emission spectra measured over the bright features showed single emission peaks having different peak energies with linewidths of

  16. Photovoltaic cell assembly

    DOEpatents

    Beavis, Leonard C. (Albuquerque, NM); Panitz, Janda K. G. (Edgewood, NM); Sharp, Donald J. (Albuquerque, NM)

    1990-01-01

    A photovoltaic assembly for converting high intensity solar radiation into lectrical energy in which a solar cell is separated from a heat sink by a thin layer of a composite material which has excellent dielectric properties and good thermal conductivity. This composite material is a thin film of porous Al.sub.2 O.sub.3 in which the pores have been substantially filled with an electrophoretically-deposited layer of a styrene-acrylate resin. This composite provides electrical breakdown strengths greater than that of a layer consisting essentially of Al.sub.2 O.sub.3 and has a higher thermal conductivity than a layer of styrene-acrylate alone.

  17. Atmospheric gas burner assembly

    SciTech Connect

    Abalos, M.

    1993-08-31

    An atmospheric gas burner assembly is described adapted for use in a domestic water heater comprising a venturi tube having an open venturi inlet end for aspirating primary air there into and in admixture with a pressurized gas fuel stream introduced axially into said tube inlet end, said venturi tube having an open outlet end communicating in air tight manner with a burner chamber portion of a gas-air burner unit, and a turbulator member comprising a metal band disposed transversely of said venturi tube adjacent said outlet end thereof and extending diametrically there across and an elongated fixed non-rotating cylindrical pointed pin member located centrally of said band and extending axially within said venturi tube with its pointed end facing upstream toward the open inlet end thereof for creating a turbulence of the gas-air mixture within and at the outlet end of said tube to minimize noise during burner operation.

  18. Flexible cloth seal assembly

    DOEpatents

    Bagepalli, Bharat Sampathkumar (Niskayuna, NY); Taura, Joseph Charles (Clifton Park, NY); Aksit, Mahmut Faruk (Troy, NY); Demiroglu, Mehmet (Troy, NY); Predmore, Daniel Ross (Clifton Park, NY)

    1999-01-01

    A seal assembly having a flexible cloth seal which includes a shim assemblage surrounded by a cloth assemblage. A first tubular end portion, such as a gas turbine combustor, includes a longitudinal axis and has smooth and spaced-apart first and second surface portions defining a notch therebetween which is wider at its top than at its bottom and which extends outward from the axis. The second surface portion is outside curved, and a first edge of the cloth seal is positioned in the bottom of the notch. A second tubular end portion, such as a first stage nozzle, is located near, spaced apart from, and coaxially aligned with, the first tubular end portion. The second tubular end portion has a smooth third surface portion which surrounds at least a portion of the first tubular end portion and which is contacted by the cloth seal.

  19. Crank shaft support assembly

    DOEpatents

    Natkin, Robert J. (Canton, MI); Oltmans, Bret (Stacy, MN); Allison, John E. (Ann Arbor, MI); Heater, Thomas J. (Milford, MI); Hines, Joy Adair (Plymouth, MI); Tappen, Grant K. (Washington, MI); Peiskammer, Dietmar (Rochester, MI)

    2007-10-23

    A crank shaft support assembly for increasing stiffness and reducing thermal mismatch distortion in a crank shaft bore of an engine comprising different materials. A cylinder block comprises a first material and at least two crank journal inserts are insert-molded into respective crank journal regions of the cylinder block and comprise a second material having greater stiffness and a lower thermal coefficient of expansion that the first material. At least two bearing caps are bolted to the respective crank journal inserts and define, along with the crank journal inserts, at least two crank shaft support rings defining a crank shaft bore coaxially aligned with a crank shaft axis. The bearing caps comprise a material having higher stiffness and a lower thermal coefficient of expansion than the first material and are supported on the respective crank journal inserts independently of any direct connection to the cylinder block.

  20. Fluid cooled electrical assembly

    DOEpatents

    Rinehart, Lawrence E.; Romero, Guillermo L.

    2007-02-06

    A heat producing, fluid cooled assembly that includes a housing made of liquid-impermeable material, which defines a fluid inlet and a fluid outlet and an opening. Also included is an electrical package having a set of semiconductor electrical devices supported on a substrate and the second major surface is a heat sink adapted to express heat generated from the electrical apparatus and wherein the second major surface defines a rim that is fit to the opening. Further, the housing is constructed so that as fluid travels from the fluid inlet to the fluid outlet it is constrained to flow past the opening thereby placing the fluid in contact with the heat sink.

  1. Microfluidic self assembly

    E-print Network

    Bingqing Shen; Joshua Ricouvier; Mathilde Reyssat; Florent Malloggi; Patrick Tabeling

    2014-09-14

    Recent progress in colloidal science has led to elaborate self-assembled structures whose complexity raises hopes for elaborating new materials. However, the throughputs are extremely low and consequently, the chance to produce materials of industrial interest, for instance, groundbreaking optical devices, harnessing complete three-dimensional band gaps, is markedly low. We discovered a novel hydrodynamic effect that may unlock this bottleneck. It is based on the dipolar flow interactions that build up when droplets are slowed down by the microchannel walls along which they are transported. Coupled with depletion forces, we succeeded to form, via a continuous flow process, at unprecedented speeds and under exquisite control, a rich ensemble of monodisperse planar and tridimensional clusters, such as chains, triangles, diamonds, tetahedrons, heterotrimers, possessing geometrical, chemical, and/or magnetic anisotropies enabling directional bonding. Continuous productions of millions of building blocks per second for elaborating new functional materials can be envisioned.

  2. Anchor bolt assembly

    SciTech Connect

    Simmons, W.J.

    1988-06-14

    This patent describes an anchor bolt assembly for securing a bolt in a bore hole having a settable bonding material therein comprising an elongated bolt having a head on one end and a threaded portion for receiving a nut at the other end, the improvement comprising in combination, (a) an essentially straight elongated rod for mixing the settable bonding material in a bore hole and (b) a bolt, the ends of the rod being attached to the bolt, (c) the rod being selectively releasable from attachment at one end when the bolt is rotated in a bore hole and subjected to increasing drag of the settable bonding material as the bonding material cures in the hole.

  3. Energy storing flywheel assembly

    SciTech Connect

    Vestermark, L. A.

    1985-08-06

    An energy storing flywheel assembly in which first and second reels are operatively connected by a flexible band, with the first and second reels capable of being rotated by first and second electric motors, and the second reel that can rotate either clockwise or counter clockwise through a clutch mechanism driving a flywheel. The flywheel that stores rotational energy is free to rotate independently of the second reel in a clockwise direction except when it is eccelerated to a predetermined maximum rate by the second reel. Acceleration of the flywheel occurs as the first motor drives the first reel at a constant rate to wind the band thereon. After the flywheel has reached the desired maximum rate of rotation the second reel is rotated to rewind the band thereon. Upon the rate of rotation of the flywheel decreasing to a predetermined minimum the above described operation is repeated.

  4. Rotatable seal assembly

    DOEpatents

    Logan, Clinton M. (Pleasanton, CA); Garibaldi, Jack L. (Livermore, CA)

    1982-01-01

    An assembly is provided for rotatably supporting a rotor on a stator so that vacuum chambers in the rotor and stator remain in communication while the chambers are sealed from ambient air, which enables the use of a ball bearing or the like to support most of the weight of the rotor. The apparatus includes a seal device mounted on the rotor to rotate therewith, but shiftable in position on the rotor while being sealed to the rotor as by an O-ring. The seal device has a flat face that is biased towards a flat face on the stator, and pressurized air is pumped between the faces to prevent contact between them while spacing them a small distance apart to avoid the inflow of large amounts of air between the faces and into the vacuum chambers.

  5. Flexible cloth seal assembly

    DOEpatents

    Bagepalli, B.S.; Taura, J.C.; Aksit, M.F.; Demiroglu, M.; Predmore, D.R.

    1999-06-29

    A seal assembly is described having a flexible cloth seal which includes a shim assemblage surrounded by a cloth assemblage. A first tubular end portion, such as a gas turbine combustor, includes a longitudinal axis and has smooth and spaced-apart first and second surface portions defining a notch there between which is wider at its top than at its bottom and which extends outward from the axis. The second surface portion is outside curved, and a first edge of the cloth seal is positioned in the bottom of the notch. A second tubular end portion, such as a first stage nozzle, is located near, spaced apart from, and coaxially aligned with, the first tubular end portion. The second tubular end portion has a smooth third surface portion which surrounds at least a portion of the first tubular end portion and which is contacted by the cloth seal. 7 figs.

  6. Microtubule assembly and disassembly at alkaline pH

    PubMed Central

    Regula, CS; Pfeiffer; Berlin, RD

    1981-01-01

    Although it is now apparent that the intracellular pH may rise considerably above neutrality under physiological conditions, information on the effect of alkaline pH on microtubule assembly and disassembly is still quite fragmentay. We have studied the assembly/disassembly of bovine brain microtubule protein at alkaline pH in vitro. When microtubules are assembled to a new steady state at pH less than 7 and pH is then made more alkaline, they undergo a rapid disassembly to a new steady state. This disassembly is reversed by acidification. The degree of disassembly is determined largely by the pH- dependence of the critical concentration, which increases five to eight times, from pH 7 to 8. A fraction of assembly-incompetent tubulin is identified that increases with pH, but its incompetency is largely reversed with acidification. Measurements of microtubule lengths are used to indicate that disassembly occurs by uniform shortening of microtubules. A comparison of shortening by alkalinization with dilution suggests that the intrinsic rate of disassembly is accelerated by increasing pH. The capacity for initiating assembly is progressively lost with incubation at alkaline pH (although some protection is afforded by sulfhydryl-reducing agents). However, direct assembly from depolymerized mixtures is possible at least up to pH 8.3, and the steady state achieved at these alkaline pH values is stable. Such preparations are readily disassembled by cold and podophyllotoxin (PLN). Disassembly induced by PLN is also markedly enhanced at alkaline pH, suggesting a corresponding enhancement of “treadmilling.” The implications of physiological events leading to alkaline shifts of pH for microtubule assembly/disassembly are discussed, particularly in the light of recent hypotheses regarding treadmilling and its role in controlling the distribution of microtubules in vivo. PMID:7228899

  7. Solid state switch

    DOEpatents

    Merritt, Bernard T. (Livermore, CA); Dreifuerst, Gary R. (Livermore, CA)

    1994-01-01

    A solid state switch, with reverse conducting thyristors, is designed to operate at 20 kV hold-off voltage, 1500 A peak, 1.0 .mu.s pulsewidth, and 4500 pps, to replace thyratrons. The solid state switch is more reliable, more economical, and more easily repaired. The switch includes a stack of circuit card assemblies, a magnetic assist and a trigger chassis. Each circuit card assembly contains a reverse conducting thyristor, a resistor capacitor network, and triggering circuitry.

  8. Self-assembled biomimetic superhydrophobic hierarchical arrays.

    PubMed

    Yang, Hongta; Dou, Xuan; Fang, Yin; Jiang, Peng

    2013-09-01

    Here, we report a simple and inexpensive bottom-up technology for fabricating superhydrophobic coatings with hierarchical micro-/nano-structures, which are inspired by the binary periodic structure found on the superhydrophobic compound eyes of some insects (e.g., mosquitoes and moths). Binary colloidal arrays consisting of exemplary large (4 and 30 ?m) and small (300 nm) silica spheres are first assembled by a scalable Langmuir-Blodgett (LB) technology in a layer-by-layer manner. After surface modification with fluorosilanes, the self-assembled hierarchical particle arrays become superhydrophobic with an apparent water contact angle (CA) larger than 150°. The throughput of the resulting superhydrophobic coatings with hierarchical structures can be significantly improved by templating the binary periodic structures of the LB-assembled colloidal arrays into UV-curable fluoropolymers by a soft lithography approach. Superhydrophobic perfluoroether acrylate hierarchical arrays with large CAs and small CA hysteresis can be faithfully replicated onto various substrates. Both experiments and theoretical calculations based on the Cassie's dewetting model demonstrate the importance of the hierarchical structure in achieving the final superhydrophobic surface states. PMID:23786830

  9. Structure, morphology, and assembly behavior of kafirin.

    PubMed

    Xiao, Jie; Li, Yunqi; Li, Ji; Gonzalez, Alejandro Perez; Xia, Qiuyang; Huang, Qingrong

    2015-01-14

    Prolamins from grains have attracted intensive attention in recent years due to their potential in satisfying the demand for environmentally friendly (biodegradable), abundantly available (sustainable), and cost-effective biomaterials. However, for kafirin, the prolamin from sorghum, its composition, structure, morphology, and self-assembly behaviors have not been fully characterized. In this paper, kafirin was extracted from the whole sorghum grain and found to contain 68, 14, 6, and 12% of ?-, ?-, and ?-fractions and cross-linked kafirin, respectively. Freeze-dried kafirin contained ?49% ?-helix in the solid state. When dissolved in 65% (v/v) isopropanol, 60% (v/v) tert-butanol, and 85% (v/v) ethanol aqueous solvents, the relative ?-helix content in kafirin increased with the decrease of solvent polarity. Structural analysis using small-angle X-ray scattering (SAXS) indicated that kafirin (2 mg/mL) took stretched and extended conformations with dimensions of 118 × 15 × 15 and 100 × 11 × 11 Å in 60% tert-butanol and 65% isopropanol, respectively. More elongated conformation of individual kafirin with high-order assembly was observed in 85% ethanol. Protein aggregation occurred as protein concentration increased in its good solvent. The morphology of kafirin assemblies captured by atomic force microscopy (AFM) revealed that kafirin protein took uniform particle morphology at low concentration, and disk-like or rod-like structures resulting from solvent evaporation induced particle interactions emerged at high concentrations. These results suggest that both protein concentration and solvent polarity can effectively regulate kafirin assemblies from thick rod-like to slim rod-like structures, a convenient way to tune the fibrillation of prolamin-based biomaterials. PMID:25510968

  10. Methacrylation Induces Rapid, Temperature-Dependent, Reversible Self-Assembly of TypeI Collagen

    E-print Network

    Shreiber, David I.

    Methacrylation Induces Rapid, Temperature-Dependent, Reversible Self-Assembly of TypeI Collagen, Piscataway, New Jersey 08854, United States ABSTRACT: Type-I collagen self-assembles into a fibrillar gel applications. In this study, type-I collagen is modified to introduce methacrylate groups on the free amines

  11. Nucleic Acid Enzymes: The Fusion of Self-assembly and Conformational Computing

    Microsoft Academic Search

    I. Ramlan; Klaus-Peter Zauner

    2009-01-01

    Macromolecules are the predominant physical substrate sup- porting information processing in organisms. Two key characteristics— conformational dynamics and self-assembly properties—render macro- molecules unique in this context. Both characteristics have been investi- gated for technical applications. In nature's information processors self- assembly and conformational switching commonly appear in combination and are typically realised with proteins. At the current state of biotech-

  12. Chunks of Charge: Effects at Play in the Assembly of Macromolecules at Fluid Surfaces

    E-print Network

    Richmond, Geraldine L.

    Chunks of Charge: Effects at Play in the Assembly of Macromolecules at Fluid Surfaces Ellen J, United States ABSTRACT: Large macromolecules with hydrophobic back- bones are known to assemble adsorption and desorption. The results have implications for related charged macromolecules whose ability

  13. Synthesis and Self-Assembly of Amphiphilic Dendrimers Based on Aliphatic Polyether-Type Dendritic Cores

    E-print Network

    Gruner, Sol M.

    Synthesis and Self-Assembly of Amphiphilic Dendrimers Based on Aliphatic Polyether-Type Dendritic Manuscript Received February 22, 2004 ABSTRACT: We have prepared a series of amphiphilic dendrimers-angle X-ray scattering (WAXS) experiments. Amphiphilic dendrimer self-assembly in the solid state

  14. Self-assembly of amphiphilic dendritic dipeptides into helical pores

    NASA Astrophysics Data System (ADS)

    Percec, Virgil; Dulcey, Andrés E.; Balagurusamy, Venkatachalapathy S. K.; Miura, Yoshiko; Smidrkal, Jan; Peterca, Mihai; Nummelin, Sami; Edlund, Ulrica; Hudson, Steven D.; Heiney, Paul A.; Duan, Hu; Magonov, Sergei N.; Vinogradov, Sergei A.

    2004-08-01

    Natural pore-forming proteins act as viral helical coats and transmembrane channels, exhibit antibacterial activity and are used in synthetic systems, such as for reversible encapsulation or stochastic sensing. These diverse functions are intimately linked to protein structure. The close link between protein structure and protein function makes the design of synthetic mimics a formidable challenge, given that structure formation needs to be carefully controlled on all hierarchy levels, in solution and in the bulk. In fact, with few exceptions, synthetic pore structures capable of assembling into periodically ordered assemblies that are stable in solution and in the solid state have not yet been realized. In the case of dendrimers, covalent and non-covalent coating and assembly of a range of different structures has only yielded closed columns. Here we describe a library of amphiphilic dendritic dipeptides that self-assemble in solution and in bulk through a complex recognition process into helical pores. We find that the molecular recognition and self-assembly process is sufficiently robust to tolerate a range of modifications to the amphiphile structure, while preliminary proton transport measurements establish that the pores are functional. We expect that this class of self-assembling dendrimers will allow the design of a variety of biologically inspired systems with functional properties arising from their porous structure.

  15. NASA AMES infrared detector assemblies

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Silicon: Gallium infrared detector assemblies were designed, fabricated, and tested using techniques representative of those employed for hybrid arrays to determine the suitability of this candidate technology for infrared astronomical detector array applications. Both the single channel assembly and the assembly using a 32 channel CMOS multiplexer are considered. The detector material was certified to have a boron background of less than 10 to the 13th power atoms/sq cm counter doped with phosphorus. The gallium concentration is 2 x 10 to the 16th power atoms/cu cm.

  16. A proximity-based programmable DNA nanoscale assembly line.

    PubMed

    Gu, Hongzhou; Chao, Jie; Xiao, Shou-Jun; Seeman, Nadrian C

    2010-05-13

    Our ability to synthesize nanometre-scale chemical species, such as nanoparticles with desired shapes and compositions, offers the exciting prospect of generating new functional materials and devices by combining them in a controlled fashion into larger structures. Self-assembly can achieve this task efficiently, but may be subject to thermodynamic and kinetic limitations: reactants, intermediates and products may collide with each other throughout the assembly time course to produce non-target species instead of target species. An alternative approach to nanoscale assembly uses information-containing molecules such as DNA to control interactions and thereby minimize unwanted cross-talk between different components. In principle, this method should allow the stepwise and programmed construction of target products by linking individually selected nanoscale components-much as an automobile is built on an assembly line. Here we demonstrate that a nanoscale assembly line can be realized by the judicious combination of three known DNA-based modules: a DNA origami tile that provides a framework and track for the assembly process, cassettes containing three independently controlled two-state DNA machines that serve as programmable cargo-donating devices and are attached in series to the tile, and a DNA walker that can move on the track from device to device and collect cargo. As the walker traverses the pathway prescribed by the origami tile track, it sequentially encounters the three DNA devices, each of which can be independently switched between an 'ON' state, allowing its cargo to be transferred to the walker, and an 'OFF' state, in which no transfer occurs. We use three different types of gold nanoparticle species as cargo and show that the experimental system does indeed allow the controlled fabrication of the eight different products that can be obtained with three two-state devices. PMID:20463734

  17. A Proximity-Based Programmable DNA Nanoscale Assembly Line

    PubMed Central

    Gu, Hongzhou; Chao, Jie; Xiao, Shou-Jun; Seeman, Nadrian C.

    2010-01-01

    Our ability to synthesize nanometer-scale particles with desired shapes and compositions offers the exciting prospect of generating new functional materials and devices by combining the particles in a controlled fashion into larger structures. Self-assembly can achieve this task efficiently, but may be subject to thermodynamic and kinetic limitations: Reactants, intermediates and products may collide with each other throughout the assembly timecourse to produce non-target instead of target species. An alternative approach to nanoscale assembly uses information-containing molecules such as DNA1 to control interactions and thereby minimize unwanted crosstalk between different components. In principle, this method should allow the stepwise and programmed construction of target products by fastening individually selected nanoscale components – much as an automobile is built on an assembly line. Here, we demonstrate that a nanoscale assembly line can indeed be realized by the judicious combination of three known DNA-based modules: a DNA origami2 tile that provides a framework and track for the assembly process, cassettes containing three distinct two-state DNA machines that serve as programmable cargo-donating devices3,4 and are attached4,5 in series to the tile, and a DNA walker that can move on the track from device to device and collect cargo. As the walker traverses the pathway prescribed by the origami tile track, it encounters sequentially the three DNA devices that can be independently switched between an ‘ON’ state allowing its cargo to be transferred to the walker, and an ‘OFF’ state where no transfer occurs. We use three different types of gold nanoparticles as cargo and show that the experimental system does indeed allow the controlled fabrication of the eight different products that can be obtained with three two-state devices. PMID:20463734

  18. Tools and methods for automated assembly of miniaturized gear systems

    NASA Astrophysics Data System (ADS)

    Nienhaus, Matthias; Ehrfeld, Wolfgang; Berg, Udo; Schmitz, Felix; Soultan, H.

    2000-10-01

    The assembly of gear systems with the size of a pin head is almost beyond the bound of human tactile skills. The magic formula for series fabrication of this hybrid micro systems is the automation of the assembly process. As a contribution, this paper presents and discusses three different assembly methods comprising specifically developed tools for different types of planetary gears with outer diameters of 1.9 mm. Because of the huge importance for the complete micro assembly process, particular attention will be dedicated to the feeding and magazining of the micro gear components. Starting with metallic gear wheels as bulk good, an extremely miniaturized gear system of the Wolfram type has been automatically assembled by employing the strategy of tolerance compensation movement. As a key component, a modular tong gripper with specifically adapted gripping jaws produced by LIGA technology has been used. Further detailed investigations were spend on handling and assembly of micro injection moulded gear wheels made of POM for a three state planetary gear system. One strategy, following the idea of in situ observation, focuses on the intensive use of electronic pattern recognition. Alternatively, an unusual method based on a novel plastic wafer magazine will be discussed in detail. Hereby the exact position and orientation of injection moulded micro components will be presented from the manufacturing process up to the final micro assembly procedure. By simplifying the moulding of the micro gears as well as their handling, storing and assembly, this method has the potential to revolutionize the series fabrication of products with dimensions in the microscopic range in general.

  19. Assembly Dynamics of Mycobacterium tuberculosis FtsZ*

    PubMed Central

    Chen, Yaodong; Anderson, David E.; Rajagopalan, Malini; Erickson, Harold P.

    2009-01-01

    We have investigated the assembly of FtsZ from Mycobacterium tuberculosis (MtbFtsZ). Electron microscopy confirmed the previous observation that MtbFtsZ assembled into long, two-stranded filaments at pH 6.5. However, we found that assembly at pH 7.2 or 7.7 produced predominantly short, one-stranded protofilaments, similar to those of Escherichia coli FtsZ (EcFtsZ). Near pH 7, which is close to the pH of M. tuberculosis cytoplasm, MtbFtsZ formed a mixture of single- and two-stranded filaments. We developed a fluorescence resonance energy transfer assay to measure the kinetics of initial assembly and the dynamic properties at steady state. Assembly of MtbFtsZ reached a plateau after 60?100 s, about 10 times slower than EcFtsZ. The initial assembly kinetics were similar at pH 6.5 and 7.7, despite the striking difference in the polymer structures. Both were fit with a cooperative assembly mechanism involving a weak dimer nucleus, similar to EcFtsZ but with slower kinetics. Subunit turnover and GTPase at steady state were also about 10 times slower for MtbFtsZ than for EcFtsZ. Specifically, the half-time for subunit turnover in vitro at pH 7.7 was 42 s for MtbFtsZ compared with 5.5 s for EcFtsZ. Photobleaching studies in vivo showed a range of turnover half-times with an average of 25 s for MtbFtsZ as compared with 9 s for EcFtsZ. PMID:17644520

  20. Flexible Foot Test Assembly

    SciTech Connect

    Kurita, C.H.; /Fermilab

    1987-04-27

    A test model of the flexible foot support was constructed early in the design stages to check its reactions to applied loads. The prototype was made of SS 304 and contained four vertical plates as opposed to the fourteen Inconel 718 plates which comprise the actual structure. Due to the fact that the prototype was built before the design of the support was finalized, the plate dimensions are different from those of the actual proposed design (i.e. model plate thickness is approximately one-half that of the actual plates). See DWG. 3740.210-MC-222376 for assembly details of the test model and DWG. 3740.210-MB-222377 for plate dimensions. This stanchion will be required to not only support the load of the inner vessel of the cryostat and its contents, but it must also allow for the movement of the vessel due to thermal contraction. Assuming that each vertical plate acts as a column, then the following formula from the Manual of Steel Construction (American Institute of Steel Construction, Inc., Eigth edition, 1980) can be applied to determine whether or not such columns undergoing simultaneous axial compression and transverse loading are considered safe for the given loading. The first term is representative of the axially compressive stress, and the second term, the bending stress. If the actual compressive stress is greater than 15% of the allowable compressive stress, then there are additional considerations which must be accounted for in the bending stress term.

  1. Gearbox assembly for vehicles

    SciTech Connect

    Imaizumi, M.; Masumura, M.; Ishikawa, T.; Hosoya, E.

    1987-01-13

    A gearbox assembly is described for a vehicle for transmitting an output of an engine to driving wheels of the vehicle, comprising: a main gearbox receiving the output and having plural forward gear-shift steps; a shift lever; a sub gearbox coupled to an output of the main gearbox having at least two relatively high and low speed gearshift steps (GH,GL) and a reverse transmission system (GR), the two steps and the reverse transmission system being selectively established through switching operation of the shift lever; wherein the sub gearbox further comprises: a rotary member connected to the shift lever for selecting one of the steps and the reverse transmission system according to its rotation; a stopper mechanism engaging the rotary member for preventing the rotary member from rotating to a position where the reverse transmission system is established; and interlinking means between the stopper mechanism and the main gearbox for releasing the stopper mechanism only when the main gearbox is in neutral or in a low speed gear-shift step; wherein the stopper mechanism comprises: a cam rotatable in response to the gear-shift operation of the main gearbox; a stopper lever one end of which faces the periphery of the cam and the other end facing the rotary member, the stopper lever being pivotally supported at its middle portion; and a spring urging the stopper level to abut against the periphery of the cam.

  2. Transmission shift control assembly

    SciTech Connect

    Dzioba, D.L.

    1989-04-18

    This patent describes a transmission shift control assembly mounted on a steering column having a longitudinal axis comprising: bracket means secured to the steering column; transmission shift cable means having a portion secured to the bracket means and a portion linearly movable relative to the secured portion; mounting means on the bracket cable drive arm means having an axis and being rotatably mounted on the rotary axis on the mounting means oblique to the longitudinal axis and including a cable connecting portion secured to the movable portion of the cable means and lever mounting means adjacent the mounting means; operator control means including lever means, pin means for pivotally mounting the lever means on the lever mounting means on an axis substantially perpendicular to the rotary axis and positioning arm means formed on the lever means and extending from the pin means; and detent gate means disposed on the bracket means in position to abut the positioning arm means for limiting the extent of pivotal movement of the lever means.

  3. Employing whole genome mapping for optimal de novo assembly of bacterial genomes

    PubMed Central

    2014-01-01

    Background De novo genome assembly can be challenging due to inherent properties of the reads, even when using current state-of-the-art assembly tools based on de Bruijn graphs. Often users are not bio-informaticians and, in a black box approach, utilise assembly parameters such as contig length and N50 to generate whole genome sequences, potentially resulting in mis-assemblies. Findings Utilising several assembly tools based on de Bruijn graphs like Velvet, SPAdes and IDBA, we demonstrate that at the optimal N50, mis-assemblies do occur, even when using the multi-k-mer approaches of SPAdes and IDBA. We demonstrate that whole genome mapping can be used to identify these mis-assemblies and can guide the selection of the best k-mer size which yields the highest N50 without mis-assemblies. Conclusions We demonstrate the utility of whole genome mapping (WGM) as a tool to identify mis-assemblies and to guide k-mer selection and higher quality de novo genome assembly of bacterial genomes. PMID:25077983

  4. Templated self-assembly for complex pattern fabrication

    E-print Network

    Chang, Jae-Byum

    2014-01-01

    The long-term goal of my Ph.D. study has been controlling the self-assembly of various materials using state-of-the-art nanofabrication techniques. Electron-beam lithography has been used for decades to generate nanoscale ...

  5. An REU Experience with Micro Assembly Workcell Research

    ERIC Educational Resources Information Center

    Stapleton, William; Asiabanpour, Bahram; Jimenez, Jesus; Um, Dugan

    2010-01-01

    Under an NSF REU center grant REU-0755355 entitled "Micro/Nano Assembly Workcell Via Micro Visual Sensing and Haptic Feedback", Texas A&M University-Corpus Christi and Texas State University-San Marcos collaboratively hosted two groups of 10 students from different backgrounds for 10 weeks each in Summer 2008 and 2009 respectively.…

  6. Epoxy adhesive behaviour on ceramic surfaces in commercial optoelectronic assemblies

    Microsoft Academic Search

    O. Williams; C. Liu; D. P. Webb; P. Firth

    2010-01-01

    Chemical and physical variability in the as-received state of aluminium oxide and aluminium nitride ceramic substrate materials used in optoelectronic modules currently leads to a process yield less than 100% when adhesives are used for assembly and interconnection. The phenomenon of epoxy bleed is a contributing factor to this yield and steps are not yet taken in the industry to

  7. Calixarene-encapsulated nanoparticles: self-assembly into functional nanomaterials{

    E-print Network

    Wei, Alexander

    Calixarene-encapsulated nanoparticles: self-assembly into functional nanomaterials{ Alexander Wei coupled, giving rise to unique collective optical or magnetic properties. The self-dependent plasmonic responses, and sub-100 nm Co nanoparticle rings with chiral magnetic states. These nanoparticle

  8. Shaft seal assembly and method

    NASA Technical Reports Server (NTRS)

    Keba, John E. (Inventor)

    2007-01-01

    A pressure-actuated shaft seal assembly and associated method for controlling the flow of fluid adjacent a rotatable shaft are provided. The seal assembly includes one or more seal members that can be adjusted between open and closed positions, for example, according to the rotational speed of the shaft. For example, the seal member can be configured to be adjusted according to a radial pressure differential in a fluid that varies with the rotational speed of the shaft. In addition, in the closed position, each seal member can contact a rotatable member connected to the shaft to form a seal with the rotatable member and prevent fluid from flowing through the assembly. Thus, the seal can be closed at low speeds of operation and opened at high speeds of operation, thereby reducing the heat and wear in the seal assembly while maintaining a sufficient seal during all speeds of operation.

  9. Direct hierarchical assembly of nanoparticles

    DOEpatents

    Xu, Ting; Zhao, Yue; Thorkelsson, Kari

    2014-07-22

    The present invention provides hierarchical assemblies of a block copolymer, a bifunctional linking compound and a nanoparticle. The block copolymers form one micro-domain and the nanoparticles another micro-domain.

  10. Shingle assembly with support bracket

    DOEpatents

    Almy, Charles

    2007-01-02

    A shingle system, mountable to a support surface, includes overlapping shingle assemblies. Each shingle assembly comprises a support bracket, having upper and lower ends, secured to a shingle body. The upper end has an upper support portion, extending away from the shingle body, and an upper support-surface-engaging part, engageable with a support surface so that the upper edge of the shingle body is positionable at a first distance from the support surface to create a first gap therebetween. The lower end has a lower support portion extending away from the lower surface. The support brackets create: (1) a second gap between shingle bodies of the first and second shingle assemblies, and (2) an open region beneath the first shingle assembly fluidly coupling the first and second gaps.

  11. Additive assembly of digital materials

    E-print Network

    Ward, Jonathan (Jonathan Daniel)

    2010-01-01

    This thesis develops the use of additive assembly of press-fit digital materials as a new rapid-prototyping process. Digital materials consist of a finite set of parts that have discrete connections and occupy discrete ...

  12. Self-assembly and nanotechnology

    NASA Astrophysics Data System (ADS)

    Whitesides, George M.

    1996-02-01

    Molecular self-assembly is a strategy for nanofabrication that involves designing molecules and supramolecular entities so that shape-complementarity causes them to aggregate into desired structures. Self-assembly has a number of advantages as a strategy: first, it carries out many of the most difficult steps in nanofabrication -- those involving atomic-level modification of structure -- using the very highly developed techniques of synthetic chemistry. Second, it draws from the enormous wealth of examples in biology for inspiration: self-assembly is one of the most important strategies used in biology for the development of complex, functional structures. Third, it can incorporate biological structures directly as components in the final systems. Fourth, because it requires that the target structures be the thermodynamically most stable ones open to the system, it tends to produce structures that are relatively defect-free and self-healing. Self-assembly also poses a number of substantial intellectual challenges. The brief summary of these challenges is that we do not yet know how to do it, and cannot even mimic those processes known to occur in biological systems at other than quite elementary levels. In addition, there are issues of function in self-assembled aggregates that need solution. The most promising avenues for self-assembly are presently those based on organic compounds, and organic compounds, as a group (although with exceptions), are electrical insulators; thus, many ideas for information processing and electrical/mechanical transduction will require either fundamental redesign in going from the macroscopic systems presently used to self-assembled systems, or the development of new types of organic molecules that show appropriate properties. This talk outlines some of these issues, and illustrates one of the approaches to self-assembled structures that has been particularly successful: that is, self- assembly on surfaces. There are now a range of different molecular systems that self-assemble -- that is, form ordered, monomolecular structures -- by the coordination of molecules to surfaces. These systems -- self-assembled monomlayers (SAMs) -- are reasonably well understood, and increasingly useful technologically. The crucial dimension in SAMs is the thickness perpendicular to the plane of the monolayer: this dimension, and the composition along this axis, can be controlled very simply at the scale of 0.1 nm by controlling the structures of the molecules making up the monolayer. (truncated)

  13. Biomimetic self-assembling acylphthalocyanines.

    PubMed

    Jin, Hong-Guang; Balaban, Mihaela Carmen; Chevallier-Michaud, Sabine; Righezza, Michel; Balaban, Teodor Silviu

    2015-07-01

    We synthesized a series of biomimetic self-assembling phthalocyanines equipped with carbonyl groups as recognition motifs, a central zinc atom and diverse solubilizing alkyl chains mimicking for the first time with these robust pigments the natural chlorosomal bacteriochlorophylls. Upon self-assembly a very broad and red-shifted Q-band absorption extending to over 900 nm is put into evidence. PMID:26112252

  14. Wafer scale micromachine assembly method

    DOEpatents

    Christenson, Todd R. (Albuquerque, NM)

    2001-01-01

    A method for fusing together, using diffusion bonding, micromachine subassemblies which are separately fabricated is described. A first and second micromachine subassembly are fabricated on a first and second substrate, respectively. The substrates are positioned so that the upper surfaces of the two micromachine subassemblies face each other and are aligned so that the desired assembly results from their fusion. The upper surfaces are then brought into contact, and the assembly is subjected to conditions suited to the desired diffusion bonding.

  15. Self-assembly and nanotechnology

    Microsoft Academic Search

    George M. Whitesides

    1996-01-01

    Molecular self-assembly is a strategy for nanofabrication that involves designing molecules and supramolecular entities so that shape-complementarity causes them to aggregate into desired structures. Self-assembly has a number of advantages as a strategy: first, it carries out many of the most difficult steps in nanofabrication -- those involving atomic-level modification of structure -- using the very highly developed techniques of

  16. An Interface for a Fragment Assembly Kernel

    Microsoft Academic Search

    Susan Larson; Mudita Jain; Eric Anson; Gene Myers

    ABSTRACT This document,describes the C programming,language interface to our Fragment Assembly Kernel library. Inputs to the Fragment Assembly Kernel are (1) DNA fragment sequences from potentially inaccurate sequencing experiments, and (2) optional constraints on fragment assembly such as known fragment overlaps or relative fragment orientation. Fragment sequence version control is supported. The Fragment Assembly Kernel produces the most probable reconstructions

  17. Automated assembly of parallel fiber optic cables

    Microsoft Academic Search

    S. A. Igl; B. A. DeBaun; N. A. Lee; T. L. Smith; G. D. Henson; A. S. Kuczma; P. K. Pepeljugoski

    1997-01-01

    The INCA (IN-line Cable Assembly) process was developed for assembling fiber optic cables automatically. During the INCA process, precisely coated fibers are laminated between the cable backing materials. Connectors are installed robotically onto the fibers as required. After the cable is assembled, the connectors are finished and body parts are added. Automation of the assembly process is efficient and results

  18. AN INTERACTIVE PROGRAM TO BALANCE ASSEMBLY LINES

    E-print Network

    Bartholdi III, John J.

    AN INTERACTIVE PROGRAM TO BALANCE ASSEMBLY LINES John J. Bartholdi, III 1992; April 3, 2003 Abstract We describe the development of a program to balance 1- or 2-sided assembly lines for a real assembly line. Key words: assembly lines, line balancing, heuristics, software Supported in part

  19. Optimal Assembly of Psychological and Educational Tests.

    ERIC Educational Resources Information Center

    van der Linden, Wim J.

    1998-01-01

    Reviews optimal test-assembly literature and introduces the contributions to this special issue. Discusses four approaches to computerized test assembly: (1) heuristic-based test assembly; (2) 0-1 linear programming; (3) network-flow programming; and (4) an optimal design approach. Contains a bibliography of 90 sources on test assembly.…

  20. Accepted Manuscript Title: Adjacent Assembly of Self-Assembled Monolayers for

    E-print Network

    Hone, James

    Accepted Manuscript Title: Adjacent Assembly of Self-Assembled Monolayers for the Construction.H. Lee, L. Amar, S. Ghassemi, J. Hone, Adjacent Assembly of Self-Assembled Monolayers interesting techniques is based on self-assembled monolayers (SAMs) [7]. Those have been greatly demonstrated

  1. Geometric and elastic properties and mechanical phase separation phenomena in self-assembling mesoscopic helical springs

    E-print Network

    Smith, Brice Christopher, 1976-

    2003-01-01

    Helical ribbons with pitch angles of either 11? or 54? self-assemble in a wide variety of quaternary surfactant-phospholipid/fatty acid-sterol-water systems. In all of the systems studied, the thermodynamically stable state ...

  2. ASSEMBLING THE KNOWLEDGE BASE

    Microsoft Academic Search

    Dorthe B. Carr; J. Mark Harris; Lisa K. Wilkening; Christopher J. Young; Matthew N. Chown; B. John Merchant; James R. Hipp

    The National Nuclear Security Administration (NNSA) Knowledge Base (KB) is a combination of the information content, database storage framework, and interface applications needed to provide integrated research products in a form that will allow the United States National Data Center (USNDC) to meet its monitoring objectives. To build a successful Knowledge Base, all the different pieces must be validated, integrated,

  3. 40 CFR 1033.630 - Staged-assembly and delegated assembly exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...locomotive. (b) Delegated assembly. This paragraph (b) applies...remanufacturer does not complete assembly of the locomotives and the...to provide an exemption for an assembly process that is not covered by the...

  4. Calixarene-encapsulated nanoparticles: self-assembly into functional nanomaterials.

    PubMed

    Wei, Alexander

    2006-04-21

    Calixarenes are excellent surfactants for enhancing the dispersion and self-assembly of metal nanoparticles into well-defined structures, particularly those with unit length scales in the 10-100 nm size range. Particles within these ensembles are strongly coupled, giving rise to unique collective optical or magnetic properties. The self-assembled nanostructures described in this feature article include 2D arrays of colloidal Au nanoparticles with size-dependent plasmonic responses, and sub-100 nm Co nanoparticle rings with chiral magnetic states. These nanoparticle assemblies may be further developed for applications in chemical sensing based on surface-enhanced Raman scattering (SERS) and as binary elements for nonvolatile memory, respectively. PMID:16582988

  5. Tritium systems test assembly stabilization

    SciTech Connect

    Jasen, W. G. (William G.); Michelotti, R. A. (Roy A.); Anast, K. R. (Kurt R.); Tesch, Charles

    2004-01-01

    The Tritium Systems Test Assembly (TSTA) was a facility dedicated to tritium technology Research and Development (R&D) primarily for future fusion power reactors. The facility was conceived in mid 1970's, operations commenced in early 1980's, stabilization and deactivation began in 2000 and were completed in 2003. The facility will remain in a Surveillance and Maintenance (S&M) mode until the Department of Energy (DOE) funds demolition of the facility, tentatively in 2009. A safe and stable end state was achieved by the TSTA Facility Stabilization Project (TFSP) in anticipation of long term S&M. At the start of the stabilization project, with an inventory of approximately 140 grams of tritium, the facility was designated a Hazard Category (HC) 2 Non-Reactor Nuclear facility as defined by US Department of Energy standard DOE-STD-1027-92 (1997). The TSTA facility comprises a laboratory area, supporting rooms, offices and associated laboratory space that included more than 20 major tritium handling systems. The project's focus was to reduce the tritium inventory by removing bulk tritium, tritiated water wastes, and tritium-contaminated high-inventory components. Any equipment that remained in the facility was stabilized in place. All of the gloveboxes and piping were rendered inoperative and vented to atmosphere. All equipment, and inventoried tritium contamination, remaining in the facility was left in a safe-and-stable state. The project used the End Points process as defined by the DOE Office of Environmental Management (web page http://www.em.doe.- gov/deact/epman.htmtlo) document and define the end state required for the stabilization of TSTA Facility. The End Points process added structure that was beneficial through virtually all phases of the project. At completion of the facility stabilization project the residual tritium inventory was approximately 3,000 curies, considerably less than the 1.6-gram threshold for a HC 3 facility. TSTA is now designated as a Radiological Facility. Innovative approaches were employed for characterization and removal of legacy wastes and high inventory components. Major accomplishments included: (1) Reduction of tritium inventory, elimination of chemical hazards, and identification and posting of remaining hazards. (2) Removal of legacy wastes. (3) Transferred equipment for reuse in other DOE projects, including some at other DOE facilities. (4) Transferred facility in a safe and stable condition to the S&M organization. The project successfully completed all project goals and the TSTA facility was transferred into S&M on August 1,2003. This project demonstrates the benefit of radiological inventory reduction and the removal of legacy wastes to achieve a safe and stable end state that protects workers and the environment pending eventual demolition of the facility.

  6. Analysis of large space structures assembly: Man/machine assembly analysis

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Procedures for analyzing large space structures assembly via three primary modes: manual, remote and automated are outlined. Data bases on each of the assembly modes and a general data base on the shuttle capabilities to support structures assembly are presented. Task element times and structure assembly component costs are given to provide a basis for determining the comparative economics of assembly alternatives. The lessons learned from simulations of space structures assembly are detailed.

  7. A theory for viral capsid assembly around electrostatic cores

    PubMed Central

    Hagan, Michael F.

    2009-01-01

    We develop equilibrium and kinetic theories that describe the assembly of viral capsid proteins on a charged central core, as seen in recent experiments in which brome mosaic virus capsids assemble around nanoparticles functionalized with polyelectrolyte. We model interactions between capsid proteins and nanoparticle surfaces as the interaction of polyelectrolyte brushes with opposite charge using the nonlinear Poisson Boltzmann equation. The models predict that there is a threshold density of functionalized charge, above which capsids efficiently assemble around nanoparticles, and that light scatter intensity increases rapidly at early times without the lag phase characteristic of empty capsid assembly. These predictions are consistent with and enable interpretation of preliminary experimental data. However, the models predict a stronger dependence of nanoparticle incorporation efficiency on functionalized charge density than measured in experiments and do not completely capture a logarithmic growth phase seen in experimental light scatter. These discrepancies may suggest the presence of metastable disordered states in the experimental system. In addition to discussing future experiments for nanoparticle-capsid systems, we discuss broader implications for understanding assembly around charged cores such as nucleic acids. PMID:19317561

  8. DNA-templated assembly of droplet-derived PEG microtissues.

    PubMed

    Li, Cheri Y; Wood, David K; Hsu, Caroline M; Bhatia, Sangeeta N

    2011-09-01

    Patterning multiple cell types is a critical step for engineering functional tissues, but few methods provide three-dimensional positioning at the cellular length scale. Here, we present a "bottom-up" approach for fabricating multicellular tissue constructs that utilizes DNA-templated assembly of 3D cell-laden hydrogel microtissues. A flow focusing-generated emulsion of photopolymerizable prepolymer is used to produce 100 ?m monodisperse microtissues at a rate of 100 Hz (10(5) h(-1)). Multiple cell types, including suspension and adherently cultured cells, can be encapsulated into the microtissues with high viability (~97%). We then use a DNA coding scheme to self-assemble microtissues "bottom-up" from a template that is defined using "top-down" techniques. The microtissues are derivatized with single-stranded DNA using a biotin-streptavidin linkage to the polymer network, and are assembled by sequence-specific hybridization onto spotted DNA microarrays. Using orthogonal DNA codes, we achieve multiplexed patterning of multiple microtissue types with high binding efficiency and >90% patterning specificity. Finally, we demonstrate the ability to organize multicomponent constructs composed of epithelial and mesenchymal microtissues while preserving each cell type in a 3D microenvironment. The combination of high throughput microtissue generation with scalable surface-templated assembly offers the potential to dissect mechanisms of cell-cell interaction in three dimensions in healthy and diseased states, as well as provides a framework for templated assembly of larger structures for implantation. PMID:21776518

  9. D0 Silicon Upgrade: Ladder Assembly Sequences

    SciTech Connect

    Ratzmann, Paul; /Fermilab

    1994-08-17

    This is an abridged version of the assembly sequence described by the DO assembly subgroup of Cooper, Hrycyk, Kowalski, Rapidis, and Ratzmann. This primarily is used to indicate major steps during the sequence and to list fixturing requirements. Assembly - (1) Place support rails in (1) 3 Chip Ladder Construction fixture. The two rails get held under vacuum. (2) Apply adhesive to the region where contact will be made with the beryllium substrates. (3) Place underside beryllium pieces (active and dummy ends) into the (1) 3 Chip Ladder Construction fixture. These pieces get placed in the fixture against the appropriate pins to mimic final positioning in the bulkhead. Apply vacuum to the beryllium pieces. Allow to cure? (4) Align silicon in (1) 3 Chip Ladder Construction fixture. Reference features on the fixture will be parameterized. Holes in the fixture near the silicon center line will be targeted to set the silicon axis relative to the beryllium slot edge. Z positioning of the detectors will be achieved by shimming between the detectors and butting up the end of the silicon against the fixture. (5) Remove silicon detectors and apply adhesive to the rails and upper surfaces of the beryllium. (6) Replace silicon and check final position of the detectors. (7) Release vacuum on the rails so they cure in a stress-free state. Allow adhesive to cure. (8) Apply adhesive and align HDI to the silicon using (2) 3 Chip HDI Gluing fixture. The HDI will have tabs which are held by the fixture for location relative to the detectors. Allow adhesive to cure. (9) Move ladder to (3) 3 Chip Wirebonding Fixture. Transfer fixture to the wirebonder and bond chip-silicon and silicon-silicon.

  10. Controllable two-stage droplet evaporation method and its nanoparticle self-assembly mechanism.

    PubMed

    Xie, Yong; Guo, Shengming; Guo, Chuanfei; He, Meng; Chen, Dongxue; Ji, Yinglu; Chen, Ziyu; Wu, Xiaochun; Liu, Qian; Xie, Sishen

    2013-05-28

    Bottom-up self-assembly is able to constitute a variety of structures and has been thought to be a promising way for advanced nanofabrication. Droplet evaporation, as the simplest method, has been used in various self-assemblies. However, the assembled area is not large enough and the order is still not well controlled. Here we show a facile and controllable two-stage droplet evaporation method by adjusting the humidity and temperature of the evaporating droplet. Taking the highly monodispersed gold nanorods (GNRs) as an example, large-area, self-assembly monolayer arrays are reproducibly achieved. To understand the self-assembly mechanism, we adopted simplified models to analyze the interactions between the nanorods. The results show that a metastable state of secondary-energy-minimum exists, especially in the latter stage of the assembly process, leading to the ordered arrays. A large electrostatic barrier between the assembled arrays prevents the formation of the multilayer structures and thereby leads to the preferential monolayers. Moreover, we predict possibilities of different types of assemblies of the nanorods, and a schematic phase diagram is finally given. The results here may offer a way toward high-quality self-assembled nanoparticles superlattices for use in enhanced spectroscopy, sensors, or nanodevices. PMID:23672308

  11. A fibril-like assembly of oligomers of a peptide derived from ?-amyloid.

    PubMed

    Pham, Johnny D; Spencer, Ryan K; Chen, Kevin H; Nowick, James S

    2014-09-10

    A macrocyclic ?-sheet peptide containing two nonapeptide segments based on A?(15-23) (QKLVFFAED) forms fibril-like assemblies of oligomers in the solid state. The X-ray crystallographic structure of macrocyclic ?-sheet peptide 3 was determined at 1.75 Å resolution. The macrocycle forms hydrogen-bonded dimers, which further assemble along the fibril axis in a fashion resembling a herringbone pattern. The extended ?-sheet comprising the dimers is laminated against a second layer of dimers through hydrophobic interactions to form a fibril-like assembly that runs the length of the crystal lattice. The second layer is offset by one monomer subunit, so that the fibril-like assembly is composed of partially overlapping dimers, rather than discrete tetramers. In aqueous solution, macrocyclic ?-sheet 3 and homologues 4 and 5 form discrete tetramers, rather than extended fibril-like assemblies. The fibril-like assemblies of oligomers formed in the solid state by macrocyclic ?-sheet 3 represent a new mode of supramolecular assembly not previously observed for the amyloidogenic central region of A?. The structures observed at atomic resolution for this peptide model system may offer insights into the structures of oligomers and oligomer assemblies formed by full-length A? and may provide a window into the propagation and replication of amyloid oligomers. PMID:25068693

  12. Mechanical filter bag shaker assembly

    SciTech Connect

    Smoluchowski, J.; Wynn, R.J.

    1981-01-27

    Mechanical shaker assembly for filter bag supporting beams which eliminates problems involved with conventional shaker assembly linkage due to variations in the dimensions of the linkage members or the location of the bag suspension beams. The assembly includes horizontal beams mounted at their ends in bearings and the beams receive shafts attached to one end of the beams. Support hangers are attached to depend from the beams and the hangers are each connected to the upper end of a filter bag. Each of the shafts has attached thereto a lever arm and opposed lever arms are connected at their ends to length adjustable tie-rods. At least one of the lever arms is also connected by a length adjustable crank arm to a motor driven crank or eccentric.

  13. Self-assembling amphiphilic peptides†

    PubMed Central

    Dehsorkhi, Ashkan; Castelletto, Valeria; Hamley, Ian W

    2014-01-01

    The self-assembly of several classes of amphiphilic peptides is reviewed, and selected applications are discussed. We discuss recent work on the self-assembly of lipopeptides, surfactant-like peptides and amyloid peptides derived from the amyloid-? peptide. The influence of environmental variables such as pH and temperature on aggregate nanostructure is discussed. Enzyme-induced remodelling due to peptide cleavage and nanostructure control through photocleavage or photo-cross-linking are also considered. Lastly, selected applications of amphiphilic peptides in biomedicine and materials science are outlined. © 2014 The Authors. Journal of Peptide Science published by European Peptide Society and John Wiley & Sons, Ltd. PMID:24729276

  14. Self-assembling holographic biosensors and biocomputers.

    SciTech Connect

    Light, Yooli Kim; Bachand, George David (Sandia National Laboratories, Albuquerque, NM); Schoeniger, Joseph S.; Trent, Amanda M. (Sandia National Laboratories, Albuquerque, NM)

    2006-05-01

    We present concepts for self-assembly of diffractive optics with potential uses in biosensors and biocomputers. The simplest such optics, diffraction gratings, can potentially be made from chemically-stabilized microtubules migrating on nanopatterned tracks of the motor protein kinesin. We discuss the fabrication challenges involved in patterning sub-micron-scale structures with proteins that must be maintained in aqueous buffers to preserve their activity. A novel strategy is presented that employs dry contact printing onto glass-supported amino-silane monolayers of heterobifunctional crosslinkers, followed by solid-state reactions of these cross-linkers, to graft patterns of reactive groups onto the surface. Successive solution-phase addition of cysteine-mutant proteins and amine-reactive polyethylene glycol allows assembly of features onto the printed patterns. We present data from initial experiments showing successful micro- and nanopatterning of lines of single-cysteine mutants of kinesin interleaved with lines of polyethylene, indicating that this strategy can be employed to arrays of features with resolutions suitable for gratings.

  15. Tubulin oligomers and microtubule assembly studied by time-resolved X-ray scattering: separation of prenucleation and nucleation events

    Microsoft Academic Search

    U. Spann; W. Renner; E. M. Mandelkow; J. Bordas

    1987-01-01

    This paper describes a time-resolved X-ray scattering study of microtubule assembly by synchrotron radiation. The method is complementary to light scattering but allows a better distinction between oligomeric and polymeric assembly states. With an improved rapid temperature jump device, it is shown that temperature-induced microtubule assembly is preceded by prenucleation and nucleation events involving oligomers of tubulin, in analogy with

  16. Solder self-assembly for MEMS fabrication

    E-print Network

    Au, Hin Meng, 1977-

    2004-01-01

    This thesis examines and demonstrates self-assembly of MEMS components on the 25 micron scale onto substrates using the capillary force of solder. This is an order of magnitude smaller than current solder self-assembly in ...

  17. 16 CFR 1508.8 - Assembly instructions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR FULL-SIZE BABY CRIBS § 1508.8 Assembly instructions. (a) Cribs, when shipped other than completely assembled, shall be...

  18. 16 CFR 1508.8 - Assembly instructions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR FULL-SIZE BABY CRIBS § 1508.8 Assembly instructions. (a) Cribs, when shipped other than completely assembled, shall be...

  19. Solar cooker and method of assembly

    SciTech Connect

    Kerr, B.P.

    1980-12-02

    A method of assembling from kit components a solar oven and in so doing, teaching the assembler the principals involving insulation, reflection, solar ray conversion to heat, temperature conservation and the fine art of cookery is described.

  20. President Mandela Address to Constitutional Assembly

    NSDL National Science Digital Library

    Mandela, Nelson, 1918-.

    1996-01-01

    Full text of the new South African Constitution, adopted by the Constitutional Assembly on May 8, 1996, and the full text of President Nelson Mandela's address to the Constitutional Assembly upon its adoption, are available via the Web.

  1. Surface Modification with Self-Assembled Monolayer &

    E-print Network

    Hong, Deog Ki

    1 1 / 40 Surface Modification with Self-Assembled Monolayer & Polymer Brush for Biotechnology Surface Modification with Self-Assembled Monolayer & Polymer Brush for Biotechnology 2 / 40 linear star comb / brush network/ crosslinked dendritic / hyperbranched homopolymer random copolymer periodic

  2. The ribosomal subunit assembly line

    PubMed Central

    Dlaki?, Mensur

    2005-01-01

    Recent proteomic studies in Saccharomyces cerevisiae have identified nearly 200 proteins, other than the structural ribosomal proteins, that participate in the assembly of ribosomal subunits and their transport from the nucleus. In a separate line of research, proteomic studies of mature plant ribosomes have revealed considerable variability in the protein composition of individual ribosomes. PMID:16207363

  3. The ribosomal subunit assembly line.

    PubMed

    Dlaki?, Mensur

    2005-01-01

    Recent proteomic studies in Saccharomyces cerevisiae have identified nearly 200 proteins, other than the structural ribosomal proteins, that participate in the assembly of ribosomal subunits and their transport from the nucleus. In a separate line of research, proteomic studies of mature plant ribosomes have revealed considerable variability in the protein composition of individual ribosomes. PMID:16207363

  4. J-2 Engine Assembly Line

    NASA Technical Reports Server (NTRS)

    1963-01-01

    J-2 engines for the Saturn IB/Saturn V launch vehicles are lined up in the assembly area at Rocketdyne's manufacturing plant in Canoga Park, California. Five J-2 engines provided more than 1,000,000 pounds of thrust to accelerate the second stage toward a Moon trajectory.

  5. Atomic Assembly of Magnetoresistive Multilayers

    E-print Network

    Wadley, Haydn

    and simulation tools to the reactive, ion-assisted vapor deposition of multilay- ered structures. It is motivated by developing new vapor deposition tools that can precisely control the vapor plumes incident upon a patterned assembly processes that occur on and within the vapor deposited film. The complexity of this has motivated

  6. Dynamics of assembly production flow

    NASA Astrophysics Data System (ADS)

    Ezaki, Takahiro; Yanagisawa, Daichi; Nishinari, Katsuhiro

    2015-06-01

    Despite recent developments in management theory, maintaining a manufacturing schedule remains difficult because of production delays and fluctuations in demand and supply of materials. The response of manufacturing systems to such disruptions to dynamic behavior has been rarely studied. To capture these responses, we investigate a process that models the assembly of parts into end products. The complete assembly process is represented by a directed tree, where the smallest parts are injected at leaves and the end products are removed at the root. A discrete assembly process, represented by a node on the network, integrates parts, which are then sent to the next downstream node as a single part. The model exhibits some intriguing phenomena, including overstock cascade, phase transition in terms of demand and supply fluctuations, nonmonotonic distribution of stockout in the network, and the formation of a stockout path and stockout chains. Surprisingly, these rich phenomena result from only the nature of distributed assembly processes. From a physical perspective, these phenomena provide insight into delay dynamics and inventory distributions in large-scale manufacturing systems.

  7. Opportunistic scheduling for robotic assembly

    Microsoft Academic Search

    B. R. Fox; K. G. Kempf

    1985-01-01

    Impressive strides have been made in dealing with the spatial complexity of robotic assembly tasks. Unfortunately, advances in dealing with temporal complexity have not kept pace. It is proposed that one reason for this deficiency is the unnecessary confounding of planning and scheduling. These two activities are differentiated on the basis of knowledge required\\/knowledge available at robot programming time. It

  8. Assembly of quasicrystalline photonic heterostructures

    DOEpatents

    Grier, David G.; Roichman, Yael; Man, Weining; Chaikin, Paul Michael; Steinhardt, Paul Joseph

    2013-03-12

    A method and system for assembling a quasicrystalline heterostructure. A plurality of particles is provided with desirable predetermined character. The particles are suspended in a medium, and holographic optical traps are used to position the particles in a way to achieve an arrangement which provides a desired property.

  9. Assembly of quasicrystalline photonic heterostructures

    DOEpatents

    Grier, David G. (New York, NY); Roichman, Yael (New York, NY); Man, Weining (Princeton, NJ); Chaikin, Paul Michael (Pennington, NJ); Steinhardt, Paul Joseph (Princeton, NJ)

    2011-07-19

    A method and system for assembling a quasicrystalline heterostructure. A plurality of particles is provided with desirable predetermined character. The particles are suspended in a medium, and holographic optical traps are used to position the particles in a way to achieve an arrangement which provides a desired property.

  10. Muscle assembly: a titanic achievement?

    Microsoft Academic Search

    Carol C Gregorio; Henk Granzier; Hiroyuki Sorimachi; Siegfried Labeit

    1999-01-01

    The formation of perfectly aligned myofibrils in striated muscle represents a dramatic example of supramolecular assembly in eukaryotic cells. Recently, considerable progress has been made in deciphering the roles that titin, the third most abundant protein in muscle, has in this process. An increasing number of sarcomeric proteins (ligands) are being identified that bind to specific titin domains. Titin may

  11. Simulated nuclear reactor fuel assembly

    DOEpatents

    Berta, Victor T. (Idaho Falls, ID)

    1993-01-01

    An apparatus for electrically simulating a nuclear reactor fuel assembly. It includes a heater assembly having a top end and a bottom end and a plurality of concentric heater tubes having electrical circuitry connected to a power source, and radially spaced from each other. An outer target tube and an inner target tube is concentric with the heater tubes and with each other, and the outer target tube surrounds and is radially spaced from the heater tubes. The inner target tube is surrounded by and radially spaced from the heater tubes and outer target tube. The top of the assembly is generally open to allow for the electrical power connection to the heater tubes, and the bottom of the assembly includes means for completing the electrical circuitry in the heater tubes to provide electrical resistance heating to simulate the power profile in a nuclear reactor. The embedded conductor elements in each heater tube is split into two halves for a substantial portion of its length and provided with electrical isolation such that each half of the conductor is joined at one end and is not joined at the other end.

  12. Simulated nuclear reactor fuel assembly

    DOEpatents

    Berta, V.T.

    1993-04-06

    An apparatus for electrically simulating a nuclear reactor fuel assembly. It includes a heater assembly having a top end and a bottom end and a plurality of concentric heater tubes having electrical circuitry connected to a power source, and radially spaced from each other. An outer target tube and an inner target tube is concentric with the heater tubes and with each other, and the outer target tube surrounds and is radially spaced from the heater tubes. The inner target tube is surrounded by and radially spaced from the heater tubes and outer target tube. The top of the assembly is generally open to allow for the electrical power connection to the heater tubes, and the bottom of the assembly includes means for completing the electrical circuitry in the heater tubes to provide electrical resistance heating to simulate the power profile in a nuclear reactor. The embedded conductor elements in each heater tube is split into two halves for a substantial portion of its length and provided with electrical isolation such that each half of the conductor is joined at one end and is not joined at the other end.

  13. Hot hollow cathode gun assembly

    DOEpatents

    Zeren, J.D.

    1983-11-22

    A hot hollow cathode deposition gun assembly includes a hollow body having a cylindrical outer surface and an end plate for holding an adjustable heat sink, the hot hollow cathode gun, two magnets for steering the plasma from the gun into a crucible on the heat sink, and a shutter for selectively covering and uncovering the crucible.

  14. Vacuum vapor deposition gun assembly

    DOEpatents

    Zeren, Joseph D. (Boulder, CO)

    1985-01-01

    A vapor deposition gun assembly includes a hollow body having a cylindrical outer surface and an end plate for holding an adjustable heat sink, a hot hollow cathode gun, two magnets for steering the plasma from the gun into a crucible on the heat sink, and a shutter for selectively covering and uncovering the crucible.

  15. Oligomeric state and membrane binding behaviour of creatine kinase isoenzymes: Implications for cellular function and mitochondrial structure

    Microsoft Academic Search

    Olaf Stachowiak; Uwe Schlattner; Max Dolder; Theo Wallimann

    1998-01-01

    The membrane binding properties of cytosolic and mitochondrial creatine kinase isoenzymes are reviewed in this article. Differences between both dimeric and octameric mitochondrial creatine kinase (Mi-CK) attached to membranes and the unbound form are elaborated with respect to possible biological function. The formation of crystalline mitochondrial inclusions under pathological conditions and its possible origin in the membrane attachment capabilities of

  16. Nanoparticles in a capillary trap: dynamic self-assembly at fluid interfaces.

    PubMed

    Sashuk, Volodymyr; Winkler, Katarzyna; ?ywoci?ski, Andrzej; Wojciechowski, Tomasz; Górecka, Ewa; Fia?kowski, Marcin

    2013-10-22

    Dynamic self-assembly is an emerging scientific concept aimed to construct artificial systems of adaptative behavior. Here, we present a first nanoscopic system that is able to dynamically self-assemble in two dimensions. This system is composed of charged gold nanoparticles, dispersed at the air-water interface, which self-assemble into a dense monolayer of area of several square centimeters in response to surface tension gradient. The surface tension gradient is imposed by localized addition or removal of organic solvent from the interface. After the surface tension is equalized over the whole fluid interface, the nanoparticles return to their initial dispersed state. The arrangement of nanoparticles before and after the self-assembly was characterized using SEM microscopy and SAXS spectroscopy. The constructed self-assembling system offers a "chemical" alternative for the Langmuir-Blodgett technique. Also, it was applied for creating self-erasing nanoparticle patterns on a fluid surface. PMID:24016224

  17. Dissection of Pilus Tip Assembly by the FimD Usher Monomer

    PubMed Central

    Allen, William J.; Phan, Gilles; Hultgren, Scott J.; Waksman, Gabriel

    2013-01-01

    Type 1 pili are representative of a class of bacterial surface structures assembled by the conserved chaperone/usher pathway and used by uropathogenic Escherichia coli to attach to bladder cells during infection. The outer membrane assembly platform—the usher—is critical for the formation of pili, catalysing the polymerisation of pilus subunits and enabling the secretion of the nascent pilus. Despite extensive structural characterisation of the usher, a number of questions about its mechanism remain, notably its oligomerisation state, and how it orchestrates the ordered assembly of pilus subunits. We demonstrate here that the FimD usher is able to catalyse in vitro pilus assembly effectively in its monomeric form. Furthermore, by establishing the kinetics of usher-catalysed reactions between various pilus subunits, we establish a complete kinetic model of tip fibrillum assembly, able to account for the order of subunits in native type 1 pili. PMID:23295826

  18. Self-optimizing assembly of laser systems

    Microsoft Academic Search

    Peter Loosen; Robert Schmitt; Christian Brecher; Rainer Müller; Max Funck; Alexander Gatej; Valentin Morasch; Alberto Pavim; Nicolas Pyschny

    2011-01-01

    Laser assembly can be a tedious task if performed manually. Especially if miniaturization of the laser is desired, robot-based\\u000a assembly can greatly improve quality, performance and throughput, while self-optimization is regarded as a strategy to reduce\\u000a planning efforts and increase the robustness of the assembly. An automated laser assembly system has been developed together\\u000a with a concept to increase the

  19. Magnetic scanning of LWR fuel assemblies

    SciTech Connect

    Fiarman, S.; Moodenbaugh, A.

    1980-01-01

    Nondestructive assay (NDA) techniques are available both for fresh and spent fuel, but generally are too time consuming and do not uniquely identify an assembly. A new method is reported to obtain a signature from a magnetic scan of each assembly. This scan is an NDA technique that detects magnetic inclusions. It is potentially fast (5 min/assembly), and may provide a unique signature from the magnetic properties of each fuel assembly.

  20. Non-latching relay switch assembly

    DOEpatents

    Duimstra, Frederick A. (Anaheim Hills, CA)

    1991-01-01

    A non-latching relay switch assembly which includes a coil section and a switch or contact section. The coil section includes a permanent magnet and an electromagnet. The respective sections are arranged in separate locations or cavities in the assembly. The switch has a "normal" position and is selectively switched by an overriding electromagnetic assembly. The switch returns to the "normal" position when the overriding electromagnetic assembly is inactive.

  1. Reactivity control assembly for nuclear reactor. [LMFBR

    DOEpatents

    Bollinger, L.R.

    1982-03-17

    This invention, which resulted from a contact with the United States Department of Energy, relates to a control mechanism for a nuclear reactor and, more particularly, to an assembly for selectively shifting different numbers of reactivity modifying rods into and out of the core of a nuclear reactor. It has been proposed heretofore to control the reactivity of a breeder reactor by varying the depth of insertion of control rods (e.g., rods containing a fertile material such as ThO/sub 2/) in the core of the reactor, thereby varying the amount of neutron-thermalizing coolant and the amount of neutron-capturing material in the core. This invention relates to a mechanism which can advantageously be used in this type of reactor control system.

  2. University Assembly Constitution as approved 10.10.13 CONSTITUTION OF THE UNIVERSITY ASSEMBLY

    E-print Network

    Pantaleone, Jim

    University Assembly Constitution as approved 10.10.13 CONSTITUTION OF THE UNIVERSITY ASSEMBLY of the University of Alaska #12;University Assembly Constitution as approved 10.10.13 Anchorage by considering all by the Chancellor, in accordance with ARTICLE X of this Constitution. B. Delegated Authority The Assembly delegates

  3. Self-Assembling Behavior and Inhibition Effect of Dodecanethiol Self-Assembled Monolayers on Copper Surface

    NASA Astrophysics Data System (ADS)

    Zhang, Xiulan; Zhang, Heng; Yang, Yihong; Chen, Zhenyu

    2013-08-01

    The self-assembling behavior and inhibition effect of dodecanethiol self-assembled monolayers (SAMs) on copper surface were investigated by atomic force microscopy (AFM) and electrochemical methods. The assembling process was monitored by AFM phase images. The assembling time influences the corrosion protection efficiency of dodecanethiol SAMs. Surface friction significantly decreases when the copper surface is covered by SAMs.

  4. An ontology for the definition and validation of assembly processes for evolvable assembly systems

    Microsoft Academic Search

    Niels Lohse; Hitendra Hirani; Svetan Ratchev; Michele Turitto

    2005-01-01

    Assembly forms eighty per cent of the cost of manufacturing a product and this is where the greatest competitive advantage can be gained as assembly has not been fully understood in the research community. This paper reports on the development of a specification ontology to describe assembly processes at a level where they can be mapped to individual assembly modules.

  5. Triangular and Hexagonal Tile Self-Assembly Systems Triangular and Hexagonal Tile Self-Assembly Systems

    E-print Network

    Kari, Lila

    -assembly. A systematic study of self-assembly as a computational process was initiated by Adleman1 , who studied the time of the construction of large squares via self-assembly. Rothemund and Winfree5 studied the self-assembly of squares. Besides a natural the- oretical interest, this study is motivated by the fact that triangular DNA tiles ha

  6. Ring assembly for inertial energy storage rotor

    Microsoft Academic Search

    Brobeck

    1978-01-01

    The invention discloses an inertial energy storage rotor defined by a plurality of independent, concentric rotor ring assemblies rotatable about a vertical axis. Each assembly has at least two co-axial rings and a plurality of circumferentially spaced apart, U-shaped clamps which secure the rings of the assembly to each other. Opposing end faces of the rings include a plurality of

  7. Determining Task Optimal Modular Robot Assembly Configurations

    Microsoft Academic Search

    I-ming Chen; Joel W. Burdick

    1995-01-01

    .A "modular" robotic system consists of standardizedjoint and link units that can be assembled into a numberof different kinematic configurations in order tomeet different task requirements. Given a predeterminedset of modules, this paper considers the problemof finding an "optimal" module assembly configurationfor a specific task. We formulate the solutionas a discrete optimization procedure. The formulationis based on an assembly incidence

  8. Precision assembly systems for medical devices

    Microsoft Academic Search

    Christine Connolly

    2009-01-01

    Purpose – The purpose of this paper is to describe the approach and technology of various companies making automated assembly equipment for medical devices. Design\\/methodology\\/approach – The structure of the medical device assembly market is introduced, and the expertise and applications of a small company working in the intermediate production market is described. The modular approach of Mikron Assembly Technology

  9. Patterning self-assembled monolayers using microcontact

    E-print Network

    Mrksich, Milan

    228 reviews Patterning self-assembled monolayers using microcontact printing: a new technology for biosensors? Milan Mrksich and George M. Whitesides Self-assembled monolayers (SAMs), formed upon. The system of self-assembled monolayers (SAMs) of alkanethiolates on gold is probably the best that is cur

  10. Combining Self-Assembled Monolayers and Mass

    E-print Network

    Mrksich, Milan

    Combining Self-Assembled Monolayers and Mass Spectrometry for Applications in Biochips Zachary A. The discussion emphasizes the use of self-assembled monolayers of alkanethiolates on gold as a structurally well current work with self-assembled monolayers (SAMs) to tailor the interfacial layer, and emphasize current

  11. Algorithm for genome contig assembly. Final report

    SciTech Connect

    NONE

    1995-09-01

    An algorithm was developed for genome contig assembly which extended the range of data types that could be included in assembly and which ran on the order of a hundred times faster than the algorithm it replaced. Maps of all existing cosmid clone and YAC data at the Human Genome Information Resource were assembled using ICA. The resulting maps are summarized.

  12. Practical Issues in Computerized Test Assembly.

    ERIC Educational Resources Information Center

    Wightman, Linda F.

    1998-01-01

    Focuses on the potential contributions of optimal test-design models to practical test-assembly issues that result from limitations in the models or the technology required for their implementation and limitations inherent in the test-assembly process. Outlines research needed to make implementation of these techniques routine in test assembly.…

  13. Faculty Assembly Meeting Minutes Posvar Hall

    E-print Network

    Jiang, Huiqiang

    to the many items on today's agenda, he has agreed to address Assembly at our next meeting. The Policy on On-line1 Faculty Assembly Meeting Minutes Posvar Hall April 29, 2014 Topic/Discussion Action Call to Order for approval of the minutes of the Faculty Assembly meeting of April 1, 2014. Minutes approved as written

  14. Mini-Brayton heat source assembly development

    NASA Technical Reports Server (NTRS)

    Wein, D.; Zimmerman, W. F.

    1978-01-01

    The work accomplished on the Mini-Brayton Heat Source Assembly program is summarized. Required technologies to design, fabricate and assemble components for a high temperature Heat Source Assembly (HSA) which would generate and transfer the thermal energy for a spaceborne Brayton Isotope Power System (BIPS) were developed.

  15. 49 CFR 572.186 - Abdomen assembly.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 7 2011-10-01 2011-10-01 false Abdomen assembly. 572.186 Section 572.186 Transportation...Dummy, 50th Percentile Adult Male § 572.186 Abdomen assembly. (a) The abdomen assembly (175-5000) is part of the...

  16. 49 CFR 572.186 - Abdomen assembly.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 7 2010-10-01 2010-10-01 false Abdomen assembly. 572.186 Section 572.186 Transportation...Dummy, 50th Percentile Adult Male § 572.186 Abdomen assembly. (a) The abdomen assembly (175-5000) is part of the...

  17. 49 CFR 572.186 - Abdomen assembly.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 7 2014-10-01 2014-10-01 false Abdomen assembly. 572.186 Section 572.186 Transportation...Dummy, 50th Percentile Adult Male § 572.186 Abdomen assembly. (a) The abdomen assembly (175-5000) is part of the...

  18. 49 CFR 572.186 - Abdomen assembly.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 7 2012-10-01 2012-10-01 false Abdomen assembly. 572.186 Section 572.186 Transportation...Dummy, 50th Percentile Adult Male § 572.186 Abdomen assembly. (a) The abdomen assembly (175-5000) is part of the...

  19. 49 CFR 572.186 - Abdomen assembly.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 7 2013-10-01 2013-10-01 false Abdomen assembly. 572.186 Section 572.186 Transportation...Dummy, 50th Percentile Adult Male § 572.186 Abdomen assembly. (a) The abdomen assembly (175-5000) is part of the...

  20. Self-Assembly of Collagen on Flat Surfaces: The Interplay of Collagen-Collagen and Collagen-Substrate Interactions

    E-print Network

    Ciobanu, Cristian

    Self-Assembly of Collagen on Flat Surfaces: The Interplay of Collagen-Collagen and Collagen, Washington 99352, United States ABSTRACT: Fibrillar collagens, common tissue scaffolds in live organisms, canH and the electrolyte concentration in solution largely control the collagen assembly, the physical reasons why

  1. AGORA: Assembly Guided by Optical Restriction Alignment

    PubMed Central

    2012-01-01

    Background Genome assembly is difficult due to repeated sequences within the genome, which create ambiguities and cause the final assembly to be broken up into many separate sequences (contigs). Long range linking information, such as mate-pairs or mapping data, is necessary to help assembly software resolve repeats, thereby leading to a more complete reconstruction of genomes. Prior work has used optical maps for validating assemblies and scaffolding contigs, after an initial assembly has been produced. However, optical maps have not previously been used within the genome assembly process. Here, we use optical map information within the popular de Bruijn graph assembly paradigm to eliminate paths in the de Bruijn graph which are not consistent with the optical map and help determine the correct reconstruction of the genome. Results We developed a new algorithm called AGORA: Assembly Guided by Optical Restriction Alignment. AGORA is the first algorithm to use optical map information directly within the de Bruijn graph framework to help produce an accurate assembly of a genome that is consistent with the optical map information provided. Our simulations on bacterial genomes show that AGORA is effective at producing assemblies closely matching the reference sequences. Additionally, we show that noise in the optical map can have a strong impact on the final assembly quality for some complex genomes, and we also measure how various characteristics of the starting de Bruijn graph may impact the quality of the final assembly. Lastly, we show that a proper choice of restriction enzyme for the optical map may substantially improve the quality of the final assembly. Conclusions Our work shows that optical maps can be used effectively to assemble genomes within the de Bruijn graph assembly framework. Our experiments also provide insights into the characteristics of the mapping data that most affect the performance of our algorithm, indicating the potential benefit of more accurate optical mapping technologies, such as nano-coding. PMID:22856673

  2. MYBPH inhibits NM IIA assembly via direct interaction with NMHC IIA and reduces cell motility

    SciTech Connect

    Hosono, Yasuyuki [Division of Molecular Carcinogenesis, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550 (Japan)] [Division of Molecular Carcinogenesis, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550 (Japan); Usukura, Jiro [Division of Integrated Project, EcoTopia Science Institute, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan)] [Division of Integrated Project, EcoTopia Science Institute, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan); Yamaguchi, Tomoya; Yanagisawa, Kiyoshi; Suzuki, Motoshi [Division of Molecular Carcinogenesis, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550 (Japan)] [Division of Molecular Carcinogenesis, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550 (Japan); Takahashi, Takashi, E-mail: tak@med.nagoya-u.ac.jp [Division of Molecular Carcinogenesis, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550 (Japan)] [Division of Molecular Carcinogenesis, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550 (Japan)

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer MYBPH inhibits NMHC IIA assembly and cell motility. Black-Right-Pointing-Pointer MYBPH interacts to assembly-competent NM IIA. Black-Right-Pointing-Pointer MYBPH inhibits RLC and NMHC IIA, independent components of NM IIA. -- Abstract: Actomyosin filament assembly is a critical step in tumor cell migration. We previously found that myosin binding protein H (MYBPH) is directly transactivated by the TTF-1 lineage-survival oncogene in lung adenocarcinomas and inhibits phosphorylation of the myosin regulatory light chain (RLC) of non-muscle myosin IIA (NM IIA) via direct interaction with Rho kinase 1 (ROCK1). Here, we report that MYBPH also directly interacts with an additional molecule, non-muscle myosin heavy chain IIA (NMHC IIA), which was found to occur between MYBPH and the rod portion of NMHC IIA. MYBPH inhibited NMHC IIA assembly and reduced cell motility. Conversely, siMYBPH-induced increased motility was partially, yet significantly, suppressed by blebbistatin, a non-muscle myosin II inhibitor, while more profound effects were attained by combined treatment with siROCK1 and blebbistatin. Electron microscopy observations showed well-ordered paracrystals of NMHC IIA reflecting an assembled state, which were significantly less frequently observed in the presence of MYBPH. Furthermore, an in vitro sedimentation assay showed that a greater amount of NMHC IIA was in an unassembled state in the presence of MYBPH. Interestingly, treatment with a ROCK inhibitor that impairs transition of NM IIA from an assembly-incompetent to assembly-competent state reduced the interaction between MYBPH and NMHC IIA, suggesting that MYBPH has higher affinity to assembly-competent NM IIA. These results suggest that MYBPH inhibits RLC and NMHC IIA, independent components of NM IIA, and negatively regulates actomyosin organization at 2 distinct steps, resulting in firm inhibition of NM IIA assembly.

  3. Institutional Reports on Pacific Rim Programs. Submissions by the California Community Colleges, the California State University, and the University of California in Response to Assembly Concurrent Resolution 82 (1986). Commission Report 87-25.

    ERIC Educational Resources Information Center

    California State Postsecondary Education Commission, Sacramento.

    Reports from the California State University, the University of California, and the California community colleges consider their roles in the Pacific Rim region. The Pacific Rim includes all lands with at least a portion of their coastlines fronting on the Pacific Ocean. Of concern are: the need for changes in program offerings and exchange…

  4. Computationally Optimised DNA Assembly of synthetic genes

    PubMed Central

    Larsen, Liza S.Z.; Wassman, Christopher D.

    2009-01-01

    Gene synthesis is hampered by two obstacles:improper assembly of oligonucleotidesoligonucleotide defects incurred during chemical synthesis. To overcome the first problem, we describe the employment of a Computationally Optimised DNA Assembly (CODA) algorithm that uses the degeneracy of the genetic code to design overlapping oligonucleotides with thermodynamic properties for self-assembly into a single, linear, DNA product. To address the second problem, we describe a hierarchical assembly strategy that reduces the incorporation of defective oligonucleotides into full-length gene constructs. The CODA algorithm and these biological methods enable fast, simple and reliable assemblies of sequence-correct full-length genes. PMID:18640907

  5. Acceleration of Amide Bond Rotation by Encapsulation in the Hydrophobic Interior of a Water-Soluble Supramolecular Assembly

    SciTech Connect

    Pluth, Michael D.; Bergman, Robert G.; Raymond, Kenneth N.

    2008-04-08

    The hydrophobic interior cavity of a self-assembled supramolecular assembly exploits the hydrophobic effect for the encapsulation of tertiary amides. Variable temperature 1H NMR experiments reveal that the free energy barrier for rotation around the C-N amide bond is lowered by up to 3.6 kcal/mol upon encapsulation. The hydrophobic cavity of the assembly is able to stabilize the less polar transition state of the amide rotation process. Carbon-13 labeling studies showed that the {sup 13}C NMR carbonyl resonance increases with temperature for the encapsulated amides which suggests that the assembly is able to favor a twisted for of the amide.

  6. Lighting up cells with lanthanide self-assembled helicates

    PubMed Central

    Bünzli, Jean-Claude G.

    2013-01-01

    Lanthanide bioprobes and bioconjugates are ideal luminescent stains in view of their low propensity to photobleaching, sharp emission lines and long excited state lifetimes permitting time-resolved detection for enhanced sensitivity. We show here how the interplay between physical, chemical and biochemical properties allied to microfluidics engineering leads to self-assembled dinuclear lanthanide luminescent probes illuminating live cells and selectively detecting biomarkers expressed by cancerous human breast cells. PMID:24511387

  7. Fibrin self-assembly inhibitor turnover in rats

    SciTech Connect

    Chiryat'ev, E.A.; Umutbaeva, M.K.; Byshevskii, A.Sh.

    1987-10-01

    The aim of this investigation was to study changes in the concentration of the fibrin self-assembly inhibitor and the mechanism of the changes in diametrically opposite states of blood coagulation, namely, the acceleration and restriction of thrombin formation. Fibrin monomer was obtained from bovine plasma. The inhibitor, a polypeptide, was labelled with potassium iodide activated with iodine 131. The radioactive inhibitor was injected and its concentration determined by chromatography and tracer analysis.

  8. A review of the A400m final assembly line balancing methodology

    NASA Astrophysics Data System (ADS)

    Ríos, J.; Mas, F.; Menéndez, J. L.

    2012-04-01

    Assembly Line Balancing (ALB) comprises ordering of tasks among workstations to satisfy precedence constraints and objective functions. However, due to the specific features of an aeronautical Final Assembly Line (FAL), such approach is not fully suitable. In a FAL, the number of workstations relates to technological criteria rather than to a calculation aiming to minimize the total number of stations. To improve current practices, a methodological approach was taken to address the conceptual modeling of an assembly line, reviewing state of the art balancing techniques and the methodology used in the AIRBUS A400M FAL.

  9. Coordination-based molecular assemblies as electrochromic materials: ultra-high switching stability and coloration efficiencies.

    PubMed

    Shankar, Sreejith; Lahav, Michal; van der Boom, Milko E

    2015-04-01

    We demonstrate high-performance electrochromic assemblies that exhibit a practical combination of low-voltage operation and efficient electrochromic switching as well as long-term thermal and redox stability (1.12 × 10(5) cycles). Our molecular assemblies can be integrated into a solid-state configuration. Furthermore, we also show how the molecular structure of the chromophores correlates with the materials' growth and function. The coloration efficiencies of our assemblies are higher than those of inorganic materials and many conducting polymers, in addition to offering an alternative fabrication approach. PMID:25730605

  10. Associative memory through self-assembly

    NASA Astrophysics Data System (ADS)

    Zeravcic, Zorana

    2015-03-01

    Self-assembly has recently emerged as a powerful technique for synthesizing structures on the nano- and micro-scale. The basis of this development is the use of biopolymers, like DNA, to design specific interactions between multiple species of components, allowing the spontaneous assembly of complex structures. Here we address a fundamental limitation of the existing approaches to self-assembly: Namely, every target structure must have its own dedicated set of components, which are programmed to assemble only that very structure. In contrast, in biological systems, the same set of components can assemble many different complexes. Inspired by this, we extend the self-assembly framework to mixtures of shared components capable of assembling distinct structures at will.

  11. Pressure-equalizing PV assembly and method

    DOEpatents

    Dinwoodie, Thomas L.

    2004-10-26

    Each PV assembly of an array of PV assemblies comprises a base, a PV module and a support assembly securing the PV module to a position overlying the upper surface of the base. Vents are formed through the base. A pressure equalization path extends from the outer surface of the PV module, past the PV module, to and through at least one of the vents, and to the lower surface of the base to help reduce wind uplift forces on the PV assembly. The PV assemblies may be interengaged, such as by interengaging the bases of adjacent PV assemblies. The base may include a main portion and a cover and the bases of adjacent PV assemblies may be interengaged by securing the covers of adjacent bases together.

  12. Fuel assembly self-excited vibration and test methodology

    SciTech Connect

    Lu, R.Y.; Broach, K. D.; McEvoy, J. J. [PWR Product Technologies, Westinghouse Electric Company, Drawer R, Columbia, SC, 29250 (United States)

    2004-07-01

    PWR fuel assemblies normally experience low amplitude, random vibration under normal reactor flow conditions. This normal fuel assembly vibration has almost no impact on grid-rod fretting wear. However, some fuel assembly designs experience a high resonant fuel assembly vibration under normal axial flow conditions. This anomalous fuel assembly vibration is defined as fuel assembly self-excitation vibration (FASE), because the assembly vibrates resonantly without any external periodic excitation force. Fuel assembly self-excitation vibration can cause severe grid-rod fretting if the assembly operates at the flow rate, which causes high fuel assembly vibration. This paper will describe the characteristics of fuel assembly self-excitation vibration and the test methodology to identify the fuel assembly vibration. Several fuel assembly designs are compared under standard test conditions. The causes for the fuel assembly self-excitation vibration are analyzed and discussed. The test acceptance criteria are defined for newly developed PWR fuel assemblies. (authors)

  13. Nuclear reactor composite fuel assembly

    DOEpatents

    Burgess, Donn M. (Richland, WA); Marr, Duane R. (West Richland, WA); Cappiello, Michael W. (Richland, WA); Omberg, Ronald P. (Richland, WA)

    1980-01-01

    A core and composite fuel assembly for a liquid-cooled breeder nuclear reactor including a plurality of elongated coextending driver and breeder fuel elements arranged to form a generally polygonal bundle within a thin-walled duct. The breeder elements are larger in cross section than the driver elements, and each breeder element is laterally bounded by a number of the driver elements. Each driver element further includes structure for spacing the driver elements from adjacent fuel elements and, where adjacent, the thin-walled duct. A core made up of the fuel elements can advantageously include fissile fuel of only one enrichment, while varying the effective enrichment of any given assembly or core region, merely by varying the relative number and size of the driver and breeder elements.

  14. Regenerator cross arm seal assembly

    DOEpatents

    Jackman, Anthony V. (Indianapolis, IN)

    1988-01-01

    A seal assembly for disposition between a cross arm on a gas turbine engine block and a regenerator disc, the seal assembly including a platform coextensive with the cross arm, a seal and wear layer sealingly and slidingly engaging the regenerator disc, a porous and compliant support layer between the platform and the seal and wear layer porous enough to permit flow of cooling air therethrough and compliant to accommodate relative thermal growth and distortion, a dike between the seal and wear layer and the platform for preventing cross flow through the support layer between engine exhaust and pressurized air passages, and air diversion passages for directing unregenerated pressurized air through the support layer to cool the seal and wear layer and then back into the flow of regenerated pressurized air.

  15. Cluster assembly of hierarchical nanostructures

    SciTech Connect

    Siegel, R.W.

    1992-02-01

    In the past few years, atom clusters with diameters in the range of 2--20 nm of a variety of materials, including both metals and ceramics, have been synthesized by evaporation and condensation in high-purity gases and subsequently consolidated in situ under ultrahigh vacuum conditions to create nanophase materials. These new utlrafine-grained materials have properties that are often significantly different and considerably improved relative to those of their coarser-grained counterparts owing to both their small grain-size scale and the large percentage of their atoms in grain boundary environments. Since their properties can be engineered during the synthesis and processing steps, cluster-assembled materials appear to have significant potential for the introduction of a hierarchy of both structure and properties. Some of the recent research on nanophase materials related to properties and scale are reviewed and some of the possibilities for synthesizing hierarchical nanostructures via cluster assembly are considered.

  16. Automated array assembly, phase 2

    NASA Technical Reports Server (NTRS)

    Carbajal, B. G.

    1979-01-01

    Tasks of scaling up the tandem junction cell (TJC) from 2 cm x 2 cm to 6.2 cm and the assembly of several modules using these large area TJC's are described. The scale-up of the TJC was based on using the existing process and doing the necessary design activities to increase the cell area to an acceptably large area. The design was carried out using available device models. The design was verified and sample large area TJCs were fabricated. Mechanical and process problems occurred causing a schedule slippage that resulted in contract expiration before enough large-area TJCs were fabricated to populate the sample tandem junction modules (TJM). A TJM design was carried out in which the module interconnects served to augment the current collecting buses on the cell. No sample TJMs were assembled due to a shortage of large-area TJCs.

  17. Combining Transcriptome Assemblies from Multiple De Novo Assemblers in the Allo-Tetraploid Plant Nicotiana benthamiana

    PubMed Central

    Nakasugi, Kenlee; Crowhurst, Ross; Bally, Julia; Waterhouse, Peter

    2014-01-01

    Background Nicotiana benthamiana is an allo-tetraploid plant, which can be challenging for de novo transcriptome assemblies due to homeologous and duplicated gene copies. Transcripts generated from such genes can be distinct yet highly similar in sequence, with markedly differing expression levels. This can lead to unassembled, partially assembled or mis-assembled contigs. Due to the different properties of de novo assemblers, no one assembler with any one given parameter space can re-assemble all possible transcripts from a transcriptome. Results In an effort to maximise the diversity and completeness of de novo assembled transcripts, we utilised four de novo transcriptome assemblers, TransAbyss, Trinity, SOAPdenovo-Trans, and Oases, using a range of k-mer sizes and different input RNA-seq read counts. We complemented the parameter space biologically by using RNA from 10 plant tissues. We then combined the output of all assemblies into a large super-set of sequences. Using a method from the EvidentialGene pipeline, the combined assembly was reduced from 9.9 million de novo assembled transcripts to about 235,000 of which about 50,000 were classified as primary. Metrics such as average bit-scores, feature response curves and the ability to distinguish paralogous or homeologous transcripts, indicated that the EvidentialGene processed assembly was of high quality. Of 35 RNA silencing gene transcripts, 34 were identified as assembled to full length, whereas in a previous assembly using only one assembler, 9 of these were partially assembled. Conclusions To achieve a high quality transcriptome, it is advantageous to implement and combine the output from as many different de novo assemblers as possible. We have in essence taking the ‘best’ output from each assembler while minimising sequence redundancy. We have also shown that simultaneous assessment of a variety of metrics, not just focused on contig length, is necessary to gauge the quality of assemblies. PMID:24614631

  18. Assembling the Skylab Orbital Workshop

    NASA Technical Reports Server (NTRS)

    1970-01-01

    This photograph was taken during assembly of the bottom and upper floors of the Skylab Orbital Workshop (OWS). The OWS was divided into two major compartments. The lower level provided crew accommodations for sleeping, food preparation and consumption, hygiene, waste processing and disposal, and performance of certain experiments. The upper level consisted of a large work area and housed water storage tanks, a food freezer, storage vaults for film, scientific airlocks, mobility and stability experiment equipment, and other experimental equipment.

  19. Metal-ceramic joint assembly

    DOEpatents

    Li, Jian (New Milford, CT)

    2002-01-01

    A metal-ceramic joint assembly in which a brazing alloy is situated between metallic and ceramic members. The metallic member is either an aluminum-containing stainless steel, a high chromium-content ferritic stainless steel or an iron nickel alloy with a corrosion protection coating. The brazing alloy, in turn, is either an Au-based or Ni-based alloy with a brazing temperature in the range of 9500 to 1200.degree. C.

  20. An advanced equation assembly module

    Microsoft Academic Search

    Stephan Wagner; Tibor Grasser; Claus Fischer; Siegfried Selberherr

    2005-01-01

    We present an advanced equation assembly module which has been developed for the simulation of semiconductor devices based\\u000a on the Finite Boxes discretization scheme and is currently used in the general purpose device and circuit simulator Minimos-NT. Such simulations require the solution of a specific set of nonlinear partial differential equations which are discretized\\u000a on a grid. The resulting nonlinear

  1. Automated aray assembly, phase 2

    NASA Technical Reports Server (NTRS)

    Daiello, R. V.

    1979-01-01

    A manufacturing process suitable for the large-scale production of silicon solar array modules at a cost of less than $500/peak kW is described. Factors which control the efficiency of ion implanted silicon solar cells, screen-printed thick film metallization, spray-on antireflection coating process, and panel assembly are discussed. Conclusions regarding technological readiness or cost effectiveness of individual process steps are presented.

  2. Rotor assembly and assay method

    DOEpatents

    Burtis, Carl A. (Oak Ridge, TN); Johnson, Wayne F. (Loudon, TN); Walker, William A. (Knoxville, TN)

    1993-01-01

    A rotor assembly for carrying out an assay includes a rotor body which is rotatable about an axis of rotation, and has a central chamber and first, second, third, fourth, fifth, and sixth chambers which are in communication with and radiate from the central chamber. The rotor assembly further includes a shuttle which is movable through the central chamber and insertable into any of the chambers, the shuttle including a reaction cup carrying an immobilized antigen or an antibody for transport among the chambers. A method for carrying out an assay using the rotor assembly includes moving the reaction cup among the six chambers by passing the cup through the central chamber between centrifugation steps in order to perform the steps of: separating plasma from blood cells, binding plasma antibody or antigen, washing, drying, binding enzyme conjugate, reacting with enzyme substrate and optically comparing the resulting reaction product with unreacted enzyme substrate solution. The movement of the reaction cup can be provided by attaching a magnet to the reaction cup and supplying a moving magnetic field to the rotor.

  3. Rotor assembly and assay method

    DOEpatents

    Burtis, C.A.; Johnson, W.F.; Walker, W.A.

    1993-09-07

    A rotor assembly for carrying out an assay includes a rotor body which is rotatable about an axis of rotation, and has a central chamber and first, second, third, fourth, fifth, and sixth chambers which are in communication with and radiate from the central chamber. The rotor assembly further includes a shuttle which is movable through the central chamber and insertable into any of the chambers, the shuttle including a reaction cup carrying an immobilized antigen or an antibody for transport among the chambers. A method for carrying out an assay using the rotor assembly includes moving the reaction cup among the six chambers by passing the cup through the central chamber between centrifugation steps in order to perform the steps of: separating plasma from blood cells, binding plasma antibody or antigen, washing, drying, binding enzyme conjugate, reacting with enzyme substrate and optically comparing the resulting reaction product with unreacted enzyme substrate solution. The movement of the reaction cup can be provided by attaching a magnet to the reaction cup and supplying a moving magnetic field to the rotor. 34 figures.

  4. Liner and drill pipe assembly

    SciTech Connect

    Lindsey, H.E.; Cole, P.W.

    1990-02-06

    This patent describes a method of cementing a linear in a well bore. It comprises: making up sections of pipe to form a liner disposed in a well bore to a desired length of liner, supporting the desired length of liner at the earth's surface while making up sections of drill pipe to form a desired string of drill pip co-axially disposed within the desired length of liner where the desired string of drill pipe has a polished mandrel and a sealing bore receptacle at its lower end when the polished mandrel is in position for sealing reception in the sealing bore receptacle, attaching a setting tool assembly to the desired string of drill pipe and attaching a liner hanger assembly with liner hanger slips to the desired length of liner; releasing the liner at the earth's surface and making up a supporting string of drill pipe attached to the setting tool assembly for lowering the co-axially disposed (telescoped) desired length of liner and string of drill pipe through the well bore hanging the liner in the well bore with liner hanger slips; pumping a volume of cement slurry through the supporting string of drill pipe; and upon the trailing end of the volume of cement slurry reaching the lower end of the desired string of drill pipe, opening the interior of the desired string of drill pipe to the interior of the liner at a location above the sealing bore receptacle.

  5. Self-assembling RNA square.

    PubMed

    Dibrov, Sergey M; McLean, Jaime; Parsons, Jerod; Hermann, Thomas

    2011-04-19

    The three-dimensional structures of noncoding RNA molecules reveal recurring architectural motifs that have been exploited for the design of artificial RNA nanomaterials. Programmed assembly of RNA nanoobjects from autonomously folding tetraloop-receptor complexes as well as junction motifs has been achieved previously through sequence-directed hybridization of complex sets of long oligonucleotides. Due to size and complexity, structural characterization of artificial RNA nanoobjects has been limited to low-resolution microscopy studies. Here we present the design, construction, and crystal structure determination at 2.2 ? of the smallest yet square-shaped nanoobject made entirely of double-stranded RNA. The RNA square is comprised of 100 residues and self-assembles from four copies each of two oligonucleotides of 10 and 15 bases length. Despite the high symmetry on the level of secondary structure, the three-dimensional architecture of the square is asymmetric, with all four corners adopting distinct folding patterns. We demonstrate the programmed self-assembly of RNA squares from complex mixtures of corner units and establish a concept to exploit the RNA square as a combinatorial nanoscale platform. PMID:21464284

  6. Multifunctional self-assembled monolayers

    SciTech Connect

    Zawodzinski, T.; Bar, G.; Rubin, S.; Uribe, F. [Los Alamos National Lab., NM (United States); Ferrais, J. [Texas Univ., Dallas, TX (United States)

    1996-06-01

    This is the final report of at three year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The specific goals of this research project were threefold: to develop multifunctional self-assembled monolayers, to understand the role of monolayer structure on the functioning of such systems, and to apply this knowledge to the development of electrochemical enzyme sensors. An array of molecules that can be used to attach electrochemically active biomolecules to gold surfaces has been synthesized. Several members of a class of electroactive compounds have been characterized and the factors controlling surface modification are beginning to be characterized. Enzymes have been attached to self-assembled molecules arranged on the gold surface, a critical step toward the ultimate goal of this project. Several alternative enzyme attachment strategies to achieve robust enzyme- modified surfaces have been explored. Several means of juxtaposing enzymes and mediators, electroactive compounds through which the enzyme can exchange electrons with the electrode surface, have also been investigated. Finally, the development of sensitive biosensors based on films loaded with nanoscale-supported gold particles that have surface modified with the self-assembled enzyme and mediator have been explored.

  7. Automated solar module assembly line

    NASA Technical Reports Server (NTRS)

    Bycer, M.

    1980-01-01

    The solar module assembly machine which Kulicke and Soffa delivered under this contract is a cell tabbing and stringing machine, and capable of handling a variety of cells and assembling strings up to 4 feet long which then can be placed into a module array up to 2 feet by 4 feet in a series of parallel arrangement, and in a straight or interdigitated array format. The machine cycle is 5 seconds per solar cell. This machine is primarily adapted to 3 inch diameter round cells with two tabs between cells. Pulsed heat is used as the bond technique for solar cell interconnects. The solar module assembly machine unloads solar cells from a cassette, automatically orients them, applies flux and solders interconnect ribbons onto the cells. It then inverts the tabbed cells, connects them into cell strings, and delivers them into a module array format using a track mounted vacuum lance, from which they are taken to test and cleaning benches prior to final encapsulation into finished solar modules. Throughout the machine the solar cell is handled very carefully, and any contact with the collector side of the cell is avoided or minimized.

  8. Self-Assembly of Globular Protein-Polymer Diblock Copolymers

    NASA Astrophysics Data System (ADS)

    Thomas, C. S.; Olsen, B. D.

    2011-03-01

    The self-assembly of globular protein-polymer diblock copolymers into nanostructured phases is demonstrated as an elegant and simple method for structural control in biocatalysis or bioelectronics. In order to fundamentally investigate self-assembly in these complex block copolymer systems, a red fluorescent protein was expressed in E. coli and site-specifically conjugated to a low polydispersity poly(N-isopropyl acrylamide) (PNIPAM) block using thiol-maleimide coupling to form a well-defined model globular protein-polymer diblock. Functional protein materials are obtained by solvent evaporation and solvent annealing above and below the lower critical solution temperature of PNIPAM in order to access different pathways toward self-assembly. Small angle x-ray scattering and microscopy are used to show that the diblock forms lamellar nanostructures and to explore dependence of nanostructure formation on processing conditions. Circular dichroism and UV-vis show that a large fraction of the protein remains in its folded state after conjugation, and wide angle x-ray scattering demonstrates that diblock copolymer self-assembly changes the protein packing symmetry.

  9. Virtual commissioning of automated micro-optical assembly

    NASA Astrophysics Data System (ADS)

    Schlette, Christian; Losch, Daniel; Haag, Sebastian; Zontar, Daniel; Roßmann, Jürgen; Brecher, Christian

    2015-02-01

    In this contribution, we present a novel approach to enable virtual commissioning for process developers in micro-optical assembly. Our approach aims at supporting micro-optics experts to effectively develop assisted or fully automated assembly solutions without detailed prior experience in programming while at the same time enabling them to easily implement their own libraries of expert schemes and algorithms for handling optical components. Virtual commissioning is enabled by a 3D simulation and visualization system in which the functionalities and properties of automated systems are modeled, simulated and controlled based on multi-agent systems. For process development, our approach supports event-, state- and time-based visual programming techniques for the agents and allows for their kinematic motion simulation in combination with looped-in simulation results for the optical components. First results have been achieved for simply switching the agents to command the real hardware setup after successful process implementation and validation in the virtual environment. We evaluated and adapted our system to meet the requirements set by industrial partners-- laser manufacturers as well as hardware suppliers of assembly platforms. The concept is applied to the automated assembly of optical components for optically pumped semiconductor lasers and positioning of optical components for beam-shaping

  10. Chiral perylene diimides: building blocks for ionic self-assembly.

    PubMed

    Echue, Geraldine; Lloyd-Jones, Guy C; Faul, Charl F J

    2015-03-23

    A chiral perylene diimide building block has been prepared based on an amine derivative of the amino acid L-phenylalanine. Detailed studies were carried out into the self-assembly behaviour of the material in solution and the solid state using UV/Vis, circular dichroism (CD) and fluorescence spectroscopy. For the charged building block BTPPP, the molecular chirality of the side chains is translated into the chiral supramolecular structure in the form of right-handed helical aggregates in aqueous solution. Temperature-dependent UV/Vis studies of BTPPP in aqueous solution showed that the self-assembly behaviour of this dye can be well described by an isodesmic model in which aggregation occurs to generate short stacks in a reversible manner. Wide-angle X-ray diffraction studies (WXRD) revealed that this material self-organises into aggregates with ?-? stacking distances typical for ?-conjugated materials. TEM investigations revealed the formation of self-assembled structures of low order and with no expression of chirality evident. Differential scanning calorimetry (DSC) and polarised optical microscopy (POM) were used to investigate the mesophase properties. Optical textures representative of columnar liquid-crystalline phases were observed for solvent-annealed samples of BTPPP. The high solubility, tunable self-assembly and chiral ordering of these materials demonstrate their potential as new molecular building blocks for use in the construction of chiro-optical structures and devices. PMID:25689392

  11. Amyloid Structure and Assembly: Insights from Scanning Transmission Electron Microscopy

    PubMed Central

    Goldsbury, Claire; Baxa, Ulrich; Simon, Martha N.; Steven, Alasdair C.; Engel, Andreas; Wall, Joseph S.; Aebi, Ueli; Müller, Shirley A.

    2010-01-01

    Amyloid fibrils are filamentous protein aggregates implicated in several common diseases like Alzheimer’s disease and type II diabetes. Similar structures are also the molecular principle of the infectious spongiform encephalopathies like Creutzfeldt-Jakob disease in humans, scrapie in sheep, and of the so-called yeast prions, inherited non-chromosomal elements found in yeast and fungi. Scanning transmission electron microscopy (STEM) is often used to delineate the assembly mechanism and structural properties of amyloid aggregates. In this review we consider specifically contributions and limitations of STEM for the investigation of amyloid assembly pathways, fibril polymorphisms and structural models of amyloid fibrils. This type of microscopy provides the only method to directly measure the mass-per-length (MPL) of individual filaments. Made on both in vitro assembled and ex vivo samples, STEM mass measurements have illuminated the hierarchical relationships between amyloid fibrils and revealed that polymorphic fibrils and various globular oligomers can assemble simultaneously from a single polypeptide. The MPLs also impose strong constraints on possible packing schemes, assisting in molecular model building when combined with high-resolution methods like solid-state nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR). PMID:20868754

  12. Interfacial Assembly of Graphene Oxide Sheets

    NASA Astrophysics Data System (ADS)

    Cote, Laura J.

    Scientific interest in graphene oxide (GO) sheets, the product of chemical oxidation and exfoliation of graphite powder, has resurged in recent years because GO is considered a promising precursor for the bulk production of graphene-based sheets for a variety of applications. In addition, GO can be viewed as an unconventional type of soft material as it is characterized by two abruptly different length scales. Its thickness is of typical molecular dimensions, measured to be about 1 nm by atomic force microscopy, but its lateral dimensions are that of common colloidal particles, ranging from nanometers to tens of microns. This high anisotropy leads to interesting fundamental colloidal interactions between the soft sheets which have practical implications in the solution processing and assembly of the material. This research therefore aims to use a variety of techniques to control these inter-sheet interactions to gain an understanding of the processing-structure relationships which ultimately determine the overall properties of the bulk GO assembly. GO is identified as a two-dimensional amphiphile with a unique edge-to-center arrangement of hydrophilic and hydrophobic groups, which has led to the demonstration of its pH- and size-dependent surface activity. The water surface is then utilized, as in the Langmuir-Blodgett technique, as an ideal substrate to tile up the GO sheets and study the interactions between them. Sheet-sheet interaction morphologies were successfully altered between wrinkled and overlapped states by pH tuning of sheet charge density, and the resulting structure-property relationships are explored. In addition, a novel flash-reduction and assembly process is described in which a simple photographic camera flash can rapidly and cleanly turn an insulating, well-stacked GO paper to a more open and fluffy conducting film. Lastly, the use of these research results as educational outreach platforms is highlighted. A variety of outlets, such as YouTube videos, laboratory tours, e-mentoring, and module creation brought this research outside the scientific community to help inspire our next generation of scientists.

  13. Self-assembly of the simple cubic lattice with an isotropic potential Mikael C. Rechtsman,1

    E-print Network

    Torquato, Salvatore

    , and electronics. We also show that standard approximate integral-equation theories of the liquid state procedure to achieve self-assembly of targeted structures M. C. Rechtsman et al., Phys. Rev. Lett. 95-dimensional many-particle system whose classical ground state is the low-coordinated simple cubic lattice

  14. Exploring the amphiphilicity of PEGylated gold nanorods: mechanical phase transfer and self-assembly.

    PubMed

    Liu, Maixian; Law, Wing-Cheung; Kopwitthaya, Atcha; Liu, Xin; Swihart, Mark T; Prasad, Paras N

    2013-10-18

    We introduce a mechanical approach to phase transfer of PEGylated gold nanorods. Amphiphilic PEG ligands can be switched between hydrophilic and hydrophobic states by applying mechanical force. PEG-GNRs in their hydrophobic state self-assemble into rings, a phenomenon previously observed only for GNRs capped with hydrophobic ligands. PMID:24003445

  15. The arginine methyltransferase NDUFAF7 is essential for complex I assembly and early vertebrate embryogenesis.

    PubMed

    Zurita Rendón, Olga; Silva Neiva, Lissiene; Sasarman, Florin; Shoubridge, Eric A

    2014-10-01

    Complex I of the mitochondrial respiratory chain is a large multisubunit enzyme that assembles from nuclear and mtDNA-encoded components. Several complex I assembly factors have been identified, but their precise functions are not well understood. Here, we have investigated the function of one of these, NDUFAF7, a soluble matrix protein comprised of a DUF185 domain that harbors a methyltransferase motif. Knockdown of NDUFAF7 by siRNA in human fibroblasts produced a specific complex I assembly defect, as did morpholino-mediated knockdown of the zebrafish ortholog. Germline disruption of the murine ortholog was an early embryonic lethal. The complex I assembly defect was characterized by rapid, AFG3L2-dependent, turnover of newly synthesized ND1, the subunit that seeds the assembly pathway, and by decreased steady-state levels of several other structural subunits including NDUFS2, NDUFS1 and NDUFA9. Expression of an NDUFAF7 mutant (G124V), predicted to disrupt methyltransferase activity, impaired complex I assembly, suggesting an assembly factor or structural subunit as a substrate for methylation. To identify the NDUFAF7 substrate, we used an anti-ND1 antibody to immunoprecipitate complex I and its associated assembly factors, followed by mass spectrometry to detect posttranslational protein modifications. Analysis of an NDUFAF7 methyltransferase mutant showed a 10-fold reduction in an NDUFS2 peptide containing dimethylated Arg85, but a 5-fold reduction in three other NDUFS2 peptides. These results show that NDUFAF7 functions to methylate NDUFS2 after it assembles into a complex I, stabilizing an early intermediate in the assembly pathway, and that this function is essential for normal vertebrate development. PMID:24838397

  16. Portable propellant cutting assembly, and method of cutting propellant with assembly

    NASA Technical Reports Server (NTRS)

    Sharp, Roger A. (Inventor); Hoskins, Shawn W. (Inventor); Payne, Brett D. (Inventor)

    2002-01-01

    A propellant cutting assembly and method of using the assembly to cut samples of solid propellant in a repeatable and consistent manner is disclosed. The cutting assembly utilizes two parallel extension beams which are shorter than the diameter of a central bore of an annular solid propellant grain and can be loaded into the central bore. The assembly is equipped with retaining heads at its respective ends and an adjustment mechanism to position and wedge the assembly within the central bore. One end of the assembly is equipped with a cutting blade apparatus which can be extended beyond the end of the extension beams to cut into the solid propellant.

  17. Photoswitchable gel assembly based on molecular recognition

    PubMed Central

    Yamaguchi, Hiroyasu; Kobayashi, Yuichiro; Kobayashi, Ryosuke; Takashima, Yoshinori; Hashidzume, Akihito; Harada, Akira

    2012-01-01

    The formation of effective and precise linkages in bottom-up or top-down processes is important for the development of self-assembled materials. Self-assembly through molecular recognition events is a powerful tool for producing functionalized materials. Photoresponsive molecular recognition systems can permit the creation of photoregulated self-assembled macroscopic objects. Here we demonstrate that macroscopic gel assembly can be highly regulated through photoisomerization of an azobenzene moiety that interacts differently with two host molecules. A photoregulated gel assembly system is developed using polyacrylamide-based hydrogels functionalized with azobenzene (guest) or cyclodextrin (host) moieties. Reversible adhesion and dissociation of the host gel from the guest gel may be controlled by photoirradiation. The differential affinities of ?-cyclodextrin or ?-cyclodextrin for the trans-azobenzene and cis-azobenzene are employed in the construction of a photoswitchable gel assembly system. PMID:22215078

  18. Chemical Reactions Directed Peptide Self-Assembly

    PubMed Central

    Rasale, Dnyaneshwar B.; Das, Apurba K.

    2015-01-01

    Fabrication of self-assembled nanostructures is one of the important aspects in nanoscience and nanotechnology. The study of self-assembled soft materials remains an area of interest due to their potential applications in biomedicine. The versatile properties of soft materials can be tuned using a bottom up approach of small molecules. Peptide based self-assembly has significant impact in biology because of its unique features such as biocompatibility, straight peptide chain and the presence of different side chain functionality. These unique features explore peptides in various self-assembly process. In this review, we briefly introduce chemical reaction-mediated peptide self-assembly. Herein, we have emphasised enzymes, native chemical ligation and photochemical reactions in the exploration of peptide self-assembly. PMID:25984603

  19. Pathways for virus assembly around nucleic acids

    E-print Network

    Perlmutter, Jason D; Hagan, Michael F

    2014-01-01

    Understanding the pathways by which viral capsid proteins assemble around their genomes could identify key intermediates as potential drug targets. In this work we use computer simulations to characterize assembly over a wide range of capsid protein-protein interaction strengths and solution ionic strengths. We find that assembly pathways can be categorized into two classes, in which intermediates are either predominantly ordered or disordered. Our results suggest that estimating the protein-protein and the protein-genome binding affinities may be sufficient to predict which pathway occurs. Furthermore, the calculated phase diagrams suggest that knowledge of the dominant assembly pathway and its relationship to control parameters could identify optimal strategies to thwart or redirect assembly to block infection. Finally, analysis of simulation trajectories suggests that the two classes of assembly pathways can be distinguished in single molecule fluorescence correlation spectroscopy or bulk time resolved sma...

  20. Pathways for virus assembly around nucleic acids

    E-print Network

    Jason D Perlmutter; Matthew R Perkett; Michael F Hagan

    2014-05-13

    Understanding the pathways by which viral capsid proteins assemble around their genomes could identify key intermediates as potential drug targets. In this work we use computer simulations to characterize assembly over a wide range of capsid protein-protein interaction strengths and solution ionic strengths. We find that assembly pathways can be categorized into two classes, in which intermediates are either predominantly ordered or disordered. Our results suggest that estimating the protein-protein and the protein-genome binding affinities may be sufficient to predict which pathway occurs. Furthermore, the calculated phase diagrams suggest that knowledge of the dominant assembly pathway and its relationship to control parameters could identify optimal strategies to thwart or redirect assembly to block infection. Finally, analysis of simulation trajectories suggests that the two classes of assembly pathways can be distinguished in single molecule fluorescence correlation spectroscopy or bulk time resolved small angle x-ray scattering experiments.

  1. The MARVEL assembly for neutron multiplication

    SciTech Connect

    David L. Chichester; Mathew T. Kinlaw

    2013-10-01

    A new multiplying test assembly is under development at Idaho National Laboratory to support research, validation, evaluation, and learning. The item is comprised of three stacked, highly-enriched uranium (HEU) cylinders, each 11.4 cm in diameter and having a combined height of up to 11.7 cm. The combined mass of all three cylinders is 20.3 kg of HEU. Calculations for the bare configuration of the assembly indicate a multiplication level of >3.5 (keff=0.72). Reflected configurations of the assembly, using either polyethylene or tungsten, are possible and have the capability of raising the assembly's multiplication level to greater than 10. This paper describes simulations performed to assess the assembly's multiplication level under different conditions and describes the resources available at INL to support the use of these materials. We also describe some preliminary calculations and test activities using the assembly to study neutron multiplication.

  2. Nanoparticle interfacial assembly in liquid crystal droplets

    NASA Astrophysics Data System (ADS)

    Rahimi, Mohammad; Roberts, Tyler; Armas-Perez, Julio; Wang, Xiaoguang; Bukusoglu, Emre; Abbott, Nicholas L.; de Pablo, Juan J.

    2015-03-01

    Controlled assembly of nanoparticles at liquid crystal interfaces could lead to easily manufacturable building blocks for assembly of materials with tunable mechanical, optical, and electronic properties. Past work has examined nanoparticle assembly at planar liquid crystal interfaces. In this work we show that nanoparticle assembly on curved interfaces is drastically different, and arises for conditions under which assembly is too weak to occur on planar interfaces. We also demonstrate that LC-mediated nanoparticle interactions are strong, are remarkably sensitive to surface anchoring, and lead to hexagonal arrangements that do not arise in bulk systems. All these elements form the basis for a highly tunable, predictable, and versatile platform for hierarchical materials assembly. National Science Foundation through the UW MRSEC.

  3. Chemical reactions directed Peptide self-assembly.

    PubMed

    Rasale, Dnyaneshwar B; Das, Apurba K

    2015-01-01

    Fabrication of self-assembled nanostructures is one of the important aspects in nanoscience and nanotechnology. The study of self-assembled soft materials remains an area of interest due to their potential applications in biomedicine. The versatile properties of soft materials can be tuned using a bottom up approach of small molecules. Peptide based self-assembly has significant impact in biology because of its unique features such as biocompatibility, straight peptide chain and the presence of different side chain functionality. These unique features explore peptides in various self-assembly process. In this review, we briefly introduce chemical reaction-mediated peptide self-assembly. Herein, we have emphasised enzymes, native chemical ligation and photochemical reactions in the exploration of peptide self-assembly. PMID:25984603

  4. Automated Array Assembly, Phase 2

    NASA Technical Reports Server (NTRS)

    Carbajal, B. G.

    1979-01-01

    The Automated Array Assembly Task, Phase 2 of the Low Cost Silicon Solar Array Project is a process development task. The contract provides for the fabrication of modules from large area tandem junction cells (TJC). During this quarter, effort was focused on the design of a large area, approximately 36 sq cm, TJC and process verification runs. The large area TJC design was optimized for minimum I squared R power losses. In the TJM activity, the cell-module interfaces were defined, module substrates were formed and heat treated and clad metal interconnect strips were fabricated.

  5. Assembly-line Simulation Program

    NASA Technical Reports Server (NTRS)

    Chamberlain, Robert G.; Zendejas, Silvino; Malhotra, Shan

    1987-01-01

    Costs and profits estimated for models based on user inputs. Standard Assembly-line Manufacturing Industry Simulation (SAMIS) program generalized so useful for production-line manufacturing companies. Provides accurate and reliable means of comparing alternative manufacturing processes. Used to assess impact of changes in financial parameters as cost of resources and services, inflation rates, interest rates, tax policies, and required rate of return of equity. Most important capability is ability to estimate prices manufacturer would have to receive for its products to recover all of costs of production and make specified profit. Written in TURBO PASCAL.

  6. Self-assembling magnetic "snakes"

    SciTech Connect

    None

    2010-01-01

    Nickel particles float peacefully in a liquid medium until a giant snake seems to swim by and snatch several particles up, adding to its own mass. The self-assembled "snakes" act like biological systems, but they are not alive and are driven by a magnetic field. The research may someday offer some insight into the organization of life itself. Read more at Wired: http://www.wired.com/wiredscience/2009/03/snakes/ Research and video by Alex Snezhko and Igor Aronson, Argonne National Laboratory.

  7. Chemoselective approaches to glycoprotein assembly

    SciTech Connect

    Hang, Howard C.; Bertozzi, Carolyn R.

    2001-02-23

    Oligosaccharides on proteins and lipids play central roles in human health and disease. The molecular analysis of glycoconjugate function has benefited tremendously from new methods for their chemical synthesis, which provides homogeneous material not attainable from biosynthetic systems. Still, glycoconjugate synthesis requires the manipulation of multiple stereocenters and protecting groups and remains the domain of a few expert laboratories around the world. This account summarizes chemoselective approaches for assembling homogeneous glycoconjugates that attempt to reduce the barriers to their synthesis. The objective of these methods is to make glycoconjugate synthesis accessible to a broader community, thereby accelerating progress in glycobiology.

  8. Method of monolithic module assembly

    DOEpatents

    Gee, James M. (Albuquerque, NM); Garrett, Stephen E. (Albuquerque, NM); Morgan, William P. (Albuquerque, NM); Worobey, Walter (Albuquerque, NM)

    1999-01-01

    Methods for "monolithic module assembly" which translate many of the advantages of monolithic module construction of thin-film PV modules to wafered c-Si PV modules. Methods employ using back-contact solar cells positioned atop electrically conductive circuit elements affixed to a planar support so that a circuit capable of generating electric power is created. The modules are encapsulated using encapsulant materials such as EVA which are commonly used in photovoltaic module manufacture. The methods of the invention allow multiple cells to be electrically connected in a single encapsulation step rather than by sequential soldering which characterizes the currently used commercial practices.

  9. Parallel Assembly of LIGA Components

    SciTech Connect

    Christenson, T.R.; Feddema, J.T.

    1999-03-04

    In this paper, a prototype robotic workcell for the parallel assembly of LIGA components is described. A Cartesian robot is used to press 386 and 485 micron diameter pins into a LIGA substrate and then place a 3-inch diameter wafer with LIGA gears onto the pins. Upward and downward looking microscopes are used to locate holes in the LIGA substrate, pins to be pressed in the holes, and gears to be placed on the pins. This vision system can locate parts within 3 microns, while the Cartesian manipulator can place the parts within 0.4 microns.

  10. Switchable supramolecular assemblies on graphene

    NASA Astrophysics Data System (ADS)

    Zhou, Qiaoyu; Li, Yibao; Li, Qiang; Wang, Yibing; Yang, Yanlian; Fang, Ying; Wang, Chen

    2014-06-01

    We studied the self-assembly of trimesic acid on single- and few-layer graphene supported by SiO2 substrates. A scanning tunneling microscope operated under ambient conditions was utilized to image supramolecular networks of trimesic acid at liquid-graphene interfaces. Trimesic acid can self-assemble into large-scale, highly ordered adlayers on graphene surfaces. Phase transition of the trimesic acid adlayer from a close-packed structure to a porous chicken-wire structure was observed by changing from single- to few-layer graphene, which was attributed to the modulation of molecule-graphene interactions by the layer number of graphene. The guest-induced phase transition of trimesic acid by complexation with coronene on single-layer graphene further confirms that supramolecular networks on graphene can be rationally tailored with sub-nanometer resolution by balancing between intermolecular vs. molecule-graphene interactions. We further investigated the effects of trimesic acid adlayers on the electronic transport properties of graphene transistors. The adsorption of trimesic acid induces p-doping and defects in the adlayers cause scattering of charge carriers in single-layer graphene.We studied the self-assembly of trimesic acid on single- and few-layer graphene supported by SiO2 substrates. A scanning tunneling microscope operated under ambient conditions was utilized to image supramolecular networks of trimesic acid at liquid-graphene interfaces. Trimesic acid can self-assemble into large-scale, highly ordered adlayers on graphene surfaces. Phase transition of the trimesic acid adlayer from a close-packed structure to a porous chicken-wire structure was observed by changing from single- to few-layer graphene, which was attributed to the modulation of molecule-graphene interactions by the layer number of graphene. The guest-induced phase transition of trimesic acid by complexation with coronene on single-layer graphene further confirms that supramolecular networks on graphene can be rationally tailored with sub-nanometer resolution by balancing between intermolecular vs. molecule-graphene interactions. We further investigated the effects of trimesic acid adlayers on the electronic transport properties of graphene transistors. The adsorption of trimesic acid induces p-doping and defects in the adlayers cause scattering of charge carriers in single-layer graphene. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr01796j

  11. Beam connector apparatus and assembly

    NASA Technical Reports Server (NTRS)

    Vontiesenhausen, G. F. (inventor)

    1983-01-01

    An apparatus and assembly for connecting beams and like structural members is disclosed which is particularly advantageous for connecting two members which are moved laterally into place. The connector apparatus requires no relative longitudinal movement between the ends of the beams or members being connected to make a connection joint. The apparatus includes a receptacle member and a connector housing carried by opposed ends of the structural member being connected. A spring-loaded connector member is carried by the connector housing which may be released for extension and engagement into the receptacle member.

  12. Algorithm for a Microfluidic Assembly Line

    NASA Astrophysics Data System (ADS)

    Schneider, Tobias M.; Mandre, Shreyas; Brenner, Michael P.

    2011-03-01

    Microfluidic technology has revolutionized the control of flows at small scales giving rise to new possibilities for assembling complex structures on the microscale. We analyze different possible algorithms for assembling arbitrary structures, and demonstrate that a sequential assembly algorithm can manufacture arbitrary 3D structures from identical constituents. We illustrate the algorithm by showing that a modified Hele-Shaw cell with 7 controlled flow rates can be designed to construct the entire English alphabet from particles that irreversibly stick to each other.

  13. Rotational joint assembly for the prosthetic leg

    NASA Technical Reports Server (NTRS)

    Owens, L. J.; Jones, W. C. (inventors)

    1977-01-01

    A rotational joint assembly for a prosthetic leg has been devised, which enables an artificial foot to rotate slightly when a person is walking, running or turning. The prosthetic leg includes upper and lower tubular members with the rotational joint assembly interposed between them. The assembly includes a restrainer mechanism which consists of a pivotably mounted paddle element. This device applies limiting force to control the rotation of the foot and also restores torque to return the foot back to its initial position.

  14. Assembly of eukaryotic algal chromosomes in yeast

    PubMed Central

    2013-01-01

    Background Synthetic genomic approaches offer unique opportunities to use powerful yeast and Escherichia coli genetic systems to assemble and modify chromosome-sized molecules before returning the modified DNA to the target host. For example, the entire 1 Mb Mycoplasma mycoides chromosome can be stably maintained and manipulated in yeast before being transplanted back into recipient cells. We have previously demonstrated that cloning in yeast of large (>?~?150 kb), high G?+?C (55%) prokaryotic DNA fragments was improved by addition of yeast replication origins every ~100 kb. Conversely, low G?+?C DNA is stable (up to at least 1.8 Mb) without adding supplemental yeast origins. It has not been previously tested whether addition of yeast replication origins similarly improves the yeast-based cloning of large (>150 kb) eukaryotic DNA with moderate G?+?C content. The model diatom Phaeodactylum tricornutum has an average G?+?C content of 48% and a 27.4 Mb genome sequence that has been assembled into chromosome-sized scaffolds making it an ideal test case for assembly and maintenance of eukaryotic chromosomes in yeast. Results We present a modified chromosome assembly technique in which eukaryotic chromosomes as large as ~500 kb can be assembled from cloned ~100 kb fragments. We used this technique to clone fragments spanning P. tricornutum chromosomes 25 and 26 and to assemble these fragments into single, chromosome-sized molecules. We found that addition of yeast replication origins improved the cloning, assembly, and maintenance of the large chromosomes in yeast. Furthermore, purification of the fragments to be assembled by electroelution greatly increased assembly efficiency. Conclusions Entire eukaryotic chromosomes can be successfully cloned, maintained, and manipulated in yeast. These results highlight the improvement in assembly and maintenance afforded by including yeast replication origins in eukaryotic DNA with moderate G?+?C content (48%). They also highlight the increased efficiency of assembly that can be achieved by purifying fragments before assembly. PMID:24325901

  15. Self-Assembly at All Scales

    Microsoft Academic Search

    George M. Whitesides; Bartosz Grzybowski

    2002-01-01

    Self-assembly is the autonomous organization of components into patterns or structures without human intervention. Self-assembling processes are common throughout nature and technology. They involve components from the molecular (crystals) to the planetary (weather systems) scale and many different kinds of interactions. The concept of self-assembly is used increasingly in many disciplines, with a different flavor and emphasis in each.

  16. Algorithm for a microfluidic assembly line

    E-print Network

    Tobias M. Schneider; Shreyas Mandre; Michael P. Brenner

    2011-01-19

    Microfluidic technology has revolutionized the control of flows at small scales giving rise to new possibilities for assembling complex structures on the microscale. We analyze different possible algorithms for assembling arbitrary structures, and demonstrate that a sequential assembly algorithm can manufacture arbitrary 3D structures from identical constituents. We illustrate the algorithm by showing that a modified Hele-Shaw cell with 7 controlled flowrates can be designed to construct the entire English alphabet from particles that irreversibly stick to each other.

  17. Assembly Modulation of Channel-Forming Peptides

    Microsoft Academic Search

    S. Futaki

    In conclusion, although within limited ranges of concentration and applied voltage, we have shown that the assembly of the\\u000a alamethicin molecules was successfully modulated by the extramembrane leucine zipper sequence. As the assembly was modulated,\\u000a ionselectivity of the channel became prominent. We have also shed light on the effect of the bulkiness of the extramembrane\\u000a segments on the assembly modulation.

  18. Assembly and Physico-Chemical Properties of Polyelectrolyte Multilayer Films Co-Assembled with Guest Species 

    E-print Network

    Huang, Xiayun

    2014-08-19

    , when assembled in the film, different types of ions or charged molecules will behave as crosslinkers and make a significant difference in film assembly and related disassembly mechanisms, compared with the more usual case of two polyelectrolytes held...

  19. Assembly and post-assembly manipulation of polyelectrolyte multilayers for control of bacterial attachment and viability

    E-print Network

    Lichter, Jenny, 1982-

    2009-01-01

    The overall goal of this thesis was to exploit the versatility of the polyelectrolyte multilayer (PEM) platform to consider bacteria-substrata interactions by varying multilayer assembly and post-assembly conditions. We ...

  20. Finishing bacterial genome assemblies with Mix

    PubMed Central

    2013-01-01

    Motivation Among challenges that hamper reaping the benefits of genome assembly are both unfinished assemblies and the ensuing experimental costs. First, numerous software solutions for genome de novo assembly are available, each having its advantages and drawbacks, without clear guidelines as to how to choose among them. Second, these solutions produce draft assemblies that often require a resource intensive finishing phase. Methods In this paper we address these two aspects by developing Mix , a tool that mixes two or more draft assemblies, without relying on a reference genome and having the goal to reduce contig fragmentation and thus speed-up genome finishing. The proposed algorithm builds an extension graph where vertices represent extremities of contigs and edges represent existing alignments between these extremities. These alignment edges are used for contig extension. The resulting output assembly corresponds to a set of paths in the extension graph that maximizes the cumulative contig length. Results We evaluate the performance of Mix on bacterial NGS data from the GAGE-B study and apply it to newly sequenced Mycoplasma genomes. Resulting final assemblies demonstrate a significant improvement in the overall assembly quality. In particular, Mix is consistent by providing better overall quality results even when the choice is guided solely by standard assembly statistics, as is the case for de novo projects. Availability Mix is implemented in Python and is available at https://github.com/cbib/MIX, novel data for our Mycoplasma study is available at http://services.cbib.u-bordeaux2.fr/mix/. PMID:24564706

  1. Fabrication of capsule assemblies, phase 3

    NASA Technical Reports Server (NTRS)

    Keeton, A. R.; Stemann, L. G.

    1973-01-01

    Thirteen capsule assemblies were fabricated for evaluation of fuel pin design concepts for a fast spectrum lithium cooled compact space power reactor. These instrumented assemblies were designed for real time test of prototype fuel pins. Uranium mononitride fuel pins were encased in AISI 304L stainless steel capsules. Fabrication procedures were fully qualified by process development and assembly qualification tests. Instrumentation reliability was achieved utilizing specially processed and closely controlled thermocouple hot zone fabrication and by thermal screening tests. Overall capsule reliability was achieved with an all electron beam welded assembly.

  2. Design configuration of GCFR core assemblies

    SciTech Connect

    LaBar, M.P.; Lee, G.E.; Meyer, R.J.

    1980-05-01

    The current design configurations of the core assemblies for the gas-cooled fast reactor (GCFR) demonstration plant reactor core conceptual design are described. Primary emphasis is placed upon the design innovations that have been incorporated in the design of the core assemblies since the establishment of the initial design of an upflow GCFR core. A major feature of the design configurations is that they are prototypical of core assemblies for use in commercial plants; a larger number of the same assemblies would be used in a commercial plant.

  3. Supramolecular Assembly in Cytoskeletal Filaments and their Associated Biomolecules

    NASA Astrophysics Data System (ADS)

    Safinya, Cyrus R.

    2002-03-01

    With the completion of the Human Genome Project and the emerging proteomics era, the biosciences community is beginning the daunting task of understanding the functions of a large number of interacting proteins. Cellular activity, which is usually tightly regulated, results from protein-protein and protein-nucleic acid interactions, which often lead to the formation of very large assemblies of biomolecules for distinct functions. Examples include DNA condensation states during the cell cycle, and bundle and network formation of filamentous proteins in cell attachment, motility, and cytokinesis. We present recent synchrotron x-ray diffraction and optical imaging data, in cell-free systems of cytoskeletal filaments and their associated biomolecules, which reveal novel supramolecular assemblies, spanning lengths from the nanometer to the micrometer scale. Supported by NSF DMR-9972246 and NIH GM59288.

  4. Mariner Venus/Mercury 1973 rocket engine assembly

    NASA Technical Reports Server (NTRS)

    Snoke, D. R.; Williams, R. S.

    1972-01-01

    The fabrication and test of rocket engine assemblies (REA) for Mariner Venus/Mercury 1973 are reported. The fabrication, assembly and flight acceptance test of seven REA's including the type approval test of one engine and fabrication of one additional kit consisting of detail parts for an engine ready for catalyst loading are presented. The MV/M '73 REA which is a nominal 51 lbs thrust monopropellant engine is described. Under steady state operation the specific impulse is not less than 228 lb-sec at 55 lb and 218.5 lb-sec at 10 lb thrust varying linearly between these limits. The characteristic velocity is not less than 4100 ft/sec at any thrust level.

  5. A review on assembly sequence planning and assembly line balancing optimisation using soft computing approaches

    Microsoft Academic Search

    Mohd Fadzil Faisae Rashid; Windo Hutabarat; Ashutosh Tiwari

    Assembly optimisation activities occur across development and production stages of manufacturing goods. Assembly Sequence\\u000a Planning (ASP) and Assembly Line Balancing (ALB) problems are among the assembly optimisation. Both of these activities are\\u000a classified as NP-hard. Several soft computing approaches using different techniques have been developed to solve ASP and ALB.\\u000a Although these approaches do not guarantee the optimum solution, they

  6. Valve stem and packing assembly

    DOEpatents

    Wordin, J.J.

    1991-09-03

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents over tightening of the retaining nut and the resulting excessive friction between stem and stem packing. 2 figures.

  7. Valve stem and packing assembly

    DOEpatents

    Wordin, John J. (Bingham County, ID)

    1991-01-01

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

  8. Subsea production test valve assembly

    SciTech Connect

    Yates, P.D.

    1988-03-22

    In the subsea test assembly securable within a blowout preventer stack above a subterranean well and positionable between upper and lower portions of a tubular conduit in fluid communication with a production zone within the well, the test assembly is described including an upper subassembly carriable with the upper conduit portion, a lower subassembly carriable with the lower conduit portion, and valve means in the lower subassembly manipulatable between opened and closed positions to control fluid flow within the conduit. The improvement comprises: the upper subassembly including an upper housing and first rigid dog means fixedly secured to the upper housing; the lower subassembly including a lower housing and second rigid dog means fixedly secured to the lower housing; the first rigid dog means positionable between a latch position for latching the upper and lower subassemblies and an unlatch position for unlatching the upper and lower subassemblies upon rotational movement of the first dog means with respect to the second dog means; and lock means axially movable relative to the first and second dog means from a lock position for limiting rotational movement of the first dog means with respect to the second dog means to an unlock position for allowing the first dog means to rotate relative to the second dog means and unlatch the upper subassembly from the lower subassembly.

  9. The International Space Station: Operations and Assembly - Learning From Experiences - Past, Present, and Future

    NASA Technical Reports Server (NTRS)

    Fuller, Sean; Dillon, William F.

    2006-01-01

    As the Space Shuttle continues flight, construction and assembly of the International Space Station (ISS) carries on as the United States and our International Partners resume the building, and continue to carry on the daily operations, of this impressive and historical Earth-orbiting research facility. In his January 14, 2004, speech announcing a new vision for America s space program, President Bush ratified the United States commitment to completing construction of the ISS by 2010. Since the launch and joining of the first two elements in 1998, the ISS and the partnership have experienced and overcome many challenges to assembly and operations, along with accomplishing many impressive achievements and historical firsts. These experiences and achievements over time have shaped our strategy, planning, and expectations. The continual operation and assembly of ISS leads to new knowledge about the design, development and operation of systems and hardware that will be utilized in the development of new deep-space vehicles needed to fulfill the Vision for Exploration and to generate the data and information that will enable our programs to return to the Moon and continue on to Mars. This paper will provide an overview of the complexity of the ISS Program, including a historical review of the major assembly events and operational milestones of the program, along with the upcoming assembly plans and scheduled missions of the space shuttle flights and ISS Assembly sequence.

  10. Equipment selection and task assignment for multiproduct assembly system design

    Microsoft Academic Search

    Stephen C. Graves; Carol Holmes Redfield

    1988-01-01

    A multiproduct assembly system produces a family of similar products, where the assembly of each product entails an ordered set of tasks. An assembly system consists of a sequence of workstations. For each workstation, we assign a subset of the assembly tasks to be performed at the workstation and select the type of assembly equipment or resource to be used

  11. Equipment for removal of the TMI2 plenum assembly

    Microsoft Academic Search

    M. W. Ales; J. D. Connell; R. V. DeMars; D. A. Nitti

    1984-01-01

    Preliminary examinations have shown that the plenum assembly is distorted and possibly might bind against the dreactor vessel and core support shield as it is lifted. Further, fuel assembly components are stuck to the bottom of the plenum assembly and particulate fuel debris is deposited in the plenum assembly. These conditions require special equipment to free the plenum assembly from

  12. Photovoltaic module on-orbit assembly for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Sours, Thomas; Lovely, R.; Clark, D.

    1989-01-01

    One of the elements of the Space Station Freedom power system is the Photovoltaic (PV) module. These modules will be assembled on-orbit during the assembly phase of the program. These modules will be assembled either from the shuttle orbiter or from the Mobile Servicing Center (MSC). The different types of assembly operations that will be used to assemble PV Modules are described.

  13. Strategies for Launch and Assembly of Modular Spacecraft

    E-print Network

    de Weck, Olivier L.

    the second topic, four separate assembly strategies involving module self-assembly, tug- based assembly1 Strategies for Launch and Assembly of Modular Spacecraft by Erica Lynn Gralla B.S.E., Mechanical;3 Strategies for Launch and Assembly of Modular Spacecraft by Erica Lynn Gralla Submitted to the Department

  14. Modular assembly: not just for phones but also for taps

    Microsoft Academic Search

    Anna Kochan

    1997-01-01

    Reviews the Prodel modular assembly system which can easily accommodate changes in product design and market demand. Describes the autonomy of the standard assembly module which can be quickly slipped into, and out of, an assembly line. Outlines applications of the modular system to mobile phone assembly and to bathroom and kitchen tap assembly.

  15. Boulder Faculty Assembly Minutes, November 1, 2012 Page 1 of 5 Boulder Faculty Assembly

    E-print Network

    Stowell, Michael

    Boulder Faculty Assembly Minutes, November 1, 2012 Page 1 of 5 MINUTES Boulder Faculty Assembly Assembly held its regular meeting on November 1, 2012 in Wolf Law 204. Chair Jerry Peterson presided a comparison of faculty governance structures; and issues regarding MOOCs (Massive On-line Open Courses

  16. Structural basis for self-assembly of a cytolytic pore lined by protein and lipid

    NASA Astrophysics Data System (ADS)

    Tanaka, Koji; Caaveiro, Jose M. M.; Morante, Koldo; González-Mañas, Juan Manuel; Tsumoto, Kouhei

    2015-02-01

    Pore-forming toxins (PFT) are water-soluble proteins that possess the remarkable ability to self-assemble on the membrane of target cells, where they form pores causing cell damage. Here, we elucidate the mechanism of action of the haemolytic protein fragaceatoxin C (FraC), a ?-barrel PFT, by determining the crystal structures of FraC at four different stages of the lytic mechanism, namely the water-soluble state, the monomeric lipid-bound form, an assembly intermediate and the fully assembled transmembrane pore. The structure of the transmembrane pore exhibits a unique architecture composed of both protein and lipids, with some of the lipids lining the pore wall, acting as assembly cofactors. The pore also exhibits lateral fenestrations that expose the hydrophobic core of the membrane to the aqueous environment. The incorporation of lipids from the target membrane within the structure of the pore provides a membrane-specific trigger for the activation of a haemolytic toxin.

  17. Computational study of trimer self-assembly and fluid phase behavior.

    PubMed

    Hatch, Harold W; Mittal, Jeetain; Shen, Vincent K

    2015-04-28

    The fluid phase diagram of trimer particles composed of one central attractive bead and two repulsive beads was determined as a function of simple geometric parameters using flat-histogram Monte Carlo methods. A variety of self-assembled structures were obtained including spherical micelle-like clusters, elongated clusters, and densely packed cylinders, depending on both the state conditions and shape of the trimer. Advanced simulation techniques were employed to determine transitions between self-assembled structures and macroscopic phases using thermodynamic and structural definitions. Simple changes in particle geometry yield dramatic changes in phase behavior, ranging from macroscopic fluid phase separation to molecular-scale self-assembly. In special cases, both self-assembled, elongated clusters and bulk fluid phase separation occur simultaneously. Our work suggests that tuning particle shape and interactions can yield superstructures with controlled architecture. PMID:25933785

  18. A Programmable Transducer Self-Assembled from DNA

    PubMed Central

    Chakraborty, Banani; Jonoska, Natasha; Seeman, Nadrian C.

    2012-01-01

    A transducer consists of an input/output alphabet, a finite set of states, and a transition function. From an input symbol applied to a given state, the transition function determines the next state, and an output symbol. Using DNA, we have constructed a transducer that divides a number by 3. The input consists of a series of individually addressable 2-state DNA nanomechanical devices that control the orientations of a group of flat 6-helix DNA motifs; these motifs have edge domains tailed in sticky ends corresponding to the numbers 0 and 1. Three-domain DNA molecules (TX tiles) act as computational tiles that correspond to the transitions that the transducer can undergo. The output domain of these TX tiles contains sticky ends that also correspond to 0 or 1. Two different DNA tiles can chelate these output domains: A 5 nm gold nanoparticle is attached to the chelating tile that binds to 0-domains and a 10 nm gold nanoparticle is attached to the chelating tile that binds to 1-domains. The answer to the division is represented by the series of gold nanoparticles, which can be interpreted as a binary number. The answers of the computation are read out by examination of the transducer complexes under a transmission electron microscope. The start or end points of the output sequence can be indicated by the presence of a 15 nm gold nanoparticle. This work demonstrates two previously unreported features integrated in a single framework: [1] a system that combines DNA algorithmic self-assembly with DNA nanomechanical devices that control that input, and [2] the arrangement of non-DNA species, here metallic nanoparticles, through DNA algorithmic self-assembly. The nanomechanical devices are controlled by single-stranded DNA strands, allowing multiple input sequences to be applied to the rest of the system, thus guiding the algorithmic self-assembly to a variety of outputs. PMID:23139854

  19. A Programmable Transducer Self-Assembled from DNA.

    PubMed

    Chakraborty, Banani; Jonoska, Natasha; Seeman, Nadrian C

    2012-01-01

    A transducer consists of an input/output alphabet, a finite set of states, and a transition function. From an input symbol applied to a given state, the transition function determines the next state, and an output symbol. Using DNA, we have constructed a transducer that divides a number by 3. The input consists of a series of individually addressable 2-state DNA nanomechanical devices that control the orientations of a group of flat 6-helix DNA motifs; these motifs have edge domains tailed in sticky ends corresponding to the numbers 0 and 1. Three-domain DNA molecules (TX tiles) act as computational tiles that correspond to the transitions that the transducer can undergo. The output domain of these TX tiles contains sticky ends that also correspond to 0 or 1. Two different DNA tiles can chelate these output domains: A 5 nm gold nanoparticle is attached to the chelating tile that binds to 0-domains and a 10 nm gold nanoparticle is attached to the chelating tile that binds to 1-domains. The answer to the division is represented by the series of gold nanoparticles, which can be interpreted as a binary number. The answers of the computation are read out by examination of the transducer complexes under a transmission electron microscope. The start or end points of the output sequence can be indicated by the presence of a 15 nm gold nanoparticle. This work demonstrates two previously unreported features integrated in a single framework: [1] a system that combines DNA algorithmic self-assembly with DNA nanomechanical devices that control that input, and [2] the arrangement of non-DNA species, here metallic nanoparticles, through DNA algorithmic self-assembly. The nanomechanical devices are controlled by single-stranded DNA strands, allowing multiple input sequences to be applied to the rest of the system, thus guiding the algorithmic self-assembly to a variety of outputs. PMID:23139854

  20. http://www.ncbi.nlm.nih.gov/projects/genome/assembly/ass embly.shtml (assembly basics overview)

    E-print Network

    Gordon, Geoffrey J.

    References http://www.ncbi.nlm.nih.gov/projects/genome/assembly/ass embly.shtml (assembly basics overview) http://ai.stanford.edu/~serafim/Publications/AssemblyRevie w.doc - sequencing assembly http://www.ncbi.nlm.nih.gov assembly) http://www.ncbi.nlm.nih.gov/pubmed/2231712 for BLAST basics (BLAST v1.0) http

  1. Applications of synchrotron radiation to the study of biopolymers in solution: Time-resolved X-ray scattering of microtubule self-assembly and oscillations

    Microsoft Academic Search

    Eckhard Mandelkow; Gudrun Lange; Eva-Maria Mandelkow

    We have used synchrotron X-ray scattering from solutions to study the assembly of biopolymers. The principles of the method are reviewed, and applications are given for the example of microtubule self-assembly. We show how different structural intermediates of the reaction can be distinguished. Assembly can take the form of a first-order approach to a steady state, but non-equilibrium phenomena are

  2. Large area space solar cell assemblies

    Microsoft Academic Search

    M. B. Spitzer; M. J. Nowlan

    1982-01-01

    Development of a large area space solar cell assembly is presented. The assembly consists of an ion implanted silicon cell and glass cover. The important attributes of fabrication are (1) use of a back surface field which is compatible with a back surface reflector, and (2) integration of coverglass application and call fabrication.

  3. Towards Assembly Automation at Small Size Scales

    E-print Network

    Gupta, Satyandra K.

    environmental impact Robotics Injection Molding Advanced Polymer Composites 3D Printing #12;In-Mold Assembly to be performed in 3D space Assembly operations need to manipulate small parts in a very tight space · Weight: Biorobotics Lab, Carnegie Mellon University #12;Our Idea · Competitive Manufacturing in US requires Material

  4. Multilayer Film Assembly of Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Cassell, Alan M.; Meyyappan, M.; Han, Jie; Arnold, J. (Technical Monitor)

    2000-01-01

    An approach to assemble multilayers of carbon nanotubes on a substrate is presented. Chemical vapor deposition using a transition metal catalyst formulation is used to grow the nanotubes. Results show a bilayer assembly of nanotubes each with a different density of tubes.

  5. Sequence Assembly Validation by Restriction Digest Fingerprint

    E-print Network

    Rouchka, Eric

    Sequence Assembly Validation by Restriction Digest Fingerprint Comparison Eric C. Rouchka and David examines the use of restriction digest analysis as a method for testing the fidelity of sequence assembly. Restriction digest fingerprint matching is an established technology for high resolution physical map

  6. Self-assembly of membrane junctions.

    PubMed Central

    Bruinsma, R; Goulian, M; Pincus, P

    1994-01-01

    We present a mechanism for the aggregation of mobile intermembrane junctions, such as the connexon dyad of gap junctions. The model demonstrates that intermembrane repulsion provides a powerful self-assembly pressure. If the membrane repulsion is strong enough to prevent membrane adhesion, then the self-assembly pressure is of effective infinite range. Images FIGURE 1 PMID:7948688

  7. Testing Gimbal Axes Before Complete Assembly

    NASA Technical Reports Server (NTRS)

    Babis, W.

    1986-01-01

    Early testing increases chances assembly will function well without expensive rework. Developed for antenna gimbals, test eliminates delay and costs ensued when fully assembled antenna fails because of excessive torque and friction in gimbal. Gimbal housing mounted above rotary table. Gimbal axis tested connected to torque transducer on table. With exception of special holder for gimbal housing, all of testing instruments commercially available items.

  8. Assembly planning research at CSIRO Australia

    Microsoft Academic Search

    S. Grewal; P. Tran; A. Bhaskare

    1995-01-01

    A concurrent engineering research project at the Commonwealth Scientific and Industrial Research Organisation of Australia (CSIRO) is addressing the issue of concurrent planning of parts and assembly with a view to developing an integrated software which will help to reduce the planning time and provide effective management of parts manufacture and assembly activities on day to day basis. The research

  9. Multiple pure tone elimination strut assembly

    Microsoft Academic Search

    F. W. Burcham

    1981-01-01

    An acoustic noise elimination assembly is disclosed which has a capability for disrupting the continuity of fields of sound pressures forwardly projected from fans or rotors of a type commonly found in the fan or compressor first stage for air-breathing engines, when operating at tip speeds in the supersonic range. The assembly includes a tubular cowl defining a duct for

  10. Conducting Assemblies in Botswana Public Schools

    ERIC Educational Resources Information Center

    Baamphatlha, Dinama

    2011-01-01

    In this paper, the author explored the teachers' experiences and their views regarding how assemblies are conducted in Botswana public schools. The author indicates that assemblies are a common feature in Botswana primary and secondary schools. The author adopted the Christian Privilege as the conceptual framework as espoused by Blumenfeld (2006)…

  11. ALSEP CASK ASSEMBLY GEARBOX THERMAL VACUUM TEST

    E-print Network

    Rathbun, Julie A.

    with the results of a thermal vacuum test on the ACA gearbox assembly which was conducted during the ACA prototype test series. The purpose of the test was to verify the operation of the ACA Gearbox Assembly when. = l. 5 in. 0. 75 in. moment arm. 4. Raw data to true force conversion = 3/. 7 5 = 4 5. Wt of ACA Band

  12. Micro and Meso Scale Robotic Assembly

    Microsoft Academic Search

    Harry E. Stephanou

    2003-01-01

    Some of the challenges associated with micro systems assembly are examined in this paper, and illustrated with examples of on-going research at the authors' institution. One of the basic challenges in precision assembly is the need for very high accuracy over a large range of motion. We address this challenge through a \\

  13. Neural signatures of cell assembly organization

    Microsoft Academic Search

    Kenneth D. Harris

    2005-01-01

    Cortical neurons show irregular but structured spike trains. This has been interpreted as evidence for 'temporal coding', whereby stimuli are represented by precise spike-timing patterns. Here, we suggest an alternative interpretation based on the older concept of the cell assembly. The dynamic evolution of assembly sequences, which are steered but not deterministically controlled by sensory input, is the proposed substrate

  14. MTI Focal Plane Assembly Design and Performance

    SciTech Connect

    Ballard, M.; Rienstra, J.L.

    1999-06-17

    The focal plane assembly for the Multispectral Thermal Imager (MTI) consists of sensor chip assemblies, optical filters, and a vacuum enclosure. Sensor chip assemblies, composed of linear detector arrays and readout integrated circuits, provide spatial resolution in the cross-track direction for the pushbroom imager. Optical filters define 15 spectral bands in a range from 0.45 {micro}m to 10.7 {micro}m. All the detector arrays are mounted on a single focal plane and are designed to operate at 75 K. Three pairs of sensor chip assemblies (SCAs) are required to provide cross-track coverage in all 15 spectral bands. Each pair of SCAs includes detector arrays made from silicon, iridium antimonide, and mercury cadmium telluride. Read out integrated circuits multiplex the signals from the detectors to 18 separate video channels. Optical filter assemblies defining the spectral bands are mounted over the linear detector arrays. Each filter assembly consists of several filter strips bonded together side-by-side. The MTI focal plane assembly has been integrated with the rest of the payload and has undergone detailed testing and calibration. This paper includes representative test data for the various spectral bands and the overall performance of the focal plane assembly.

  15. PACING EFFECTS ON MANNED ASSEMBLY LINES

    Microsoft Academic Search

    L. E. DAVIS

    1965-01-01

    A computer simulation of an assembly line enforcing pacing on manned sequential stations indicates that unpaced station operations are superior to paced. Using the variability and work-time distribution of operator performance on repetitive tasks, a number of studies were carried out which show that an assembly line cannot perform at maximum efficiency (in terms of operator idle time and units

  16. Assembly Line Balancing with a Precedence Matrix

    Microsoft Academic Search

    Thomas R. Hoffmann

    1963-01-01

    Assembly line balancing consists of assigning work elements, which are subject to sequencing restrictions, along an assembly line in an optimal manner. The procedure presented in this paper leads to optimal line balances by operation on a matrix of zeros and ones called a \\

  17. A genetic algorithm for assembly line balancing

    Microsoft Academic Search

    G. SURESH; V. V. VINOD; S. SAHU

    1996-01-01

    Assembly line balancing is a very important aspect in any mass production setup. However, finding the optimal balance is a very difficult proposition because of the computational complexity involved. Hence sub-optimal solutions are preferred over optimal solutions. In this work, a genetic algorithm (GA) is presented for obtaining good quality solutions for assembly line balancing problems. A major feature of

  18. A classification of assembly line balancing problems

    Microsoft Academic Search

    Nils Boysen; Malte Fliedner; Armin Scholl

    2007-01-01

    Assembly lines are special flow-line production systems which are of great importance in the indus- trial production of high quantity standardized commodities. Recently, assembly lines even gained importance in low volume production of customized products (mass-customization). Due to high capital requirements when installing or redesigning a line, its configuration planning is of great rele- vance for practitioners. Accordingly, this attracted

  19. Mounting assembly for heater thermostat control

    Microsoft Academic Search

    1987-01-01

    This patent describes an assembly for mounting a thermostat control on the outer wall of a heater tank including an external spud in which a heating element is mounted. The mounting assembly comprises: a first bracket made from a spring material and including a body having an opening adapted to lockingly fit over the tank spud. The first bracket further

  20. Pv-Thermal Solar Power Assembly

    DOEpatents

    Ansley, Jeffrey H. (El Cerrito, CA); Botkin, Jonathan D. (El Cerrito, CA); Dinwoodie, Thomas L. (Piedmont, CA)

    2001-10-02

    A flexible solar power assembly includes a flexible photovoltaic device attached to a flexible thermal solar collector. The solar power assembly can be rolled up for transport and then unrolled for installation on a surface, such as the roof or side wall of a building or other structure, by use of adhesive and/or other types of fasteners.

  1. [Energy requirements of railroad bridge assemblers].

    PubMed

    Ratner, E M; Kirpichnikov, A B; Evlampieva, M N; Bondarev, G I; Demina, D M

    1982-01-01

    A study was made of energy losses in the assemblers engaged in the construction of a railway bridge. It was established that daily energy losses in this vocational group did not exceed 2900 kcal. Basing on the data obtained the authors calculated the requirements of the assemblers for the main foods, vitamins and mineral elements. PMID:7090323

  2. Formal Verification of Self-Assembling Systems

    E-print Network

    Sterling, Aaron

    2010-01-01

    This paper introduces the theory and practice of formal verification of self-assembling systems. We interpret a well-studied abstraction of nanomolecular self assembly, the Abstract Tile Assembly Model (aTAM), into Computation Tree Logic (CTL), a temporal logic often used in model checking. We then consider the class of "rectilinear" tile assembly systems. This class includes most aTAM systems studied in the theoretical literature, and all (algorithmic) DNA tile self-assembling systems that have been realized in laboratories to date. We present a polynomial-time algorithm that, given a tile assembly system T as input, either provides a counterexample to T's rectilinearity or verifies whether T has a unique terminal assembly. Using partial order reductions, the verification search space for this algorithm is reduced from exponential size to O(n^2), where n x n is the size of the assembly surface. That reduction is asymptotically the best possible. We report on experimental results obtained by translating tile ...

  3. Fringing Field Directed Assembly of Nanomaterials

    E-print Network

    Jacobs, Heiko O.

    Fringing Field Directed Assembly of Nanomaterials Chad R. Barry and Heiko O. Jacobs* Department on a new gas-phase printing approach to deposit nanomaterials into addressable areas on a surface with 50 and SiO2) with openings to a silicon substrate are used to direct the assembly of nanomaterials

  4. Broadcast distributed control for assembly modules

    Microsoft Academic Search

    I. Lobl

    1995-01-01

    Assembly stations, also known as cells, is a generalized term denoting the place where one of the operations is carried out in the sequence needed to assemble a product. As each station m general is dedicated to a specific operation on a specific product, it is uncommon to find two instances of the same station. Stations are custom designed and

  5. An evolutionary fuel assembly design for high power density BWRs

    E-print Network

    Karahan, Aydin

    2007-01-01

    An evolutionary BWR fuel assembly design was studied as a means to increase the power density of current and future BWR cores. The new assembly concept is based on replacing four traditional assemblies and large water gap ...

  6. BORED AND ASSEMBLED GATE VALVES RECEIVING PROTECTIVE COATING IN THE ...

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

    BORED AND ASSEMBLED GATE VALVES RECEIVING PROTECTIVE COATING IN THE VALVE PAINT BOOTH OF THE VALVE ASSEMBLY BUILDING. - Stockham Pipe & Fittings Company, Valve Assembly Building, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  7. 36. ASSEMBLY LINE AREA FROM NEAR INTERIOR LOADING DOCK. VIEW ...

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

    36. ASSEMBLY LINE AREA FROM NEAR INTERIOR LOADING DOCK. VIEW TO WEST-NORTHWEST. - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  8. Examining De Novo Transcriptome Assemblies via a Quality Assessment Pipeline

    E-print Network

    Ghaffari, Noushin; Arshad, Osama A.; Jeong, Hyundoo; Thiltges, John; Criscitiello, Michael F.; Yoon, Byung-Jun; Datta, Aniruddha; Johnson, Charles D.

    2015-06-05

    New de novo transcriptome assembly and annotation methods provide an incredible opportunity to study the transcriptome of organisms that lack an assembled and annotated genome. There are currently a number of de novo transcriptome assembly methods...

  9. Liquid-liquid interfacial nanoparticle assemblies

    DOEpatents

    Emrick, Todd S. (South Deerfield, MA); Russell, Thomas P. (Amherst, MA); Dinsmore, Anthony (Amherst, MA); Skaff, Habib (Amherst, MA); Lin, Yao (Amherst, MA)

    2008-12-30

    Self-assembly of nanoparticles at the interface between two fluids, and methods to control such self-assembly process, e.g., the surface density of particles assembling at the interface; to utilize the assembled nanoparticles and their ligands in fabrication of capsules, where the elastic properties of the capsules can be varied from soft to tough; to develop capsules with well-defined porosities for ultimate use as delivery systems; and to develop chemistries whereby multiple ligands or ligands with multiple functionalities can be attached to the nanoparticles to promote the interfacial segregation and assembly of the nanoparticles. Certain embodiments use cadmium selenide (CdSe) nanoparticles, since the photoluminescence of the particles provides a convenient means by which the spatial location and organization of the particles can be probed. However, the systems and methodologies presented here are general and can, with suitable modification of the chemistries, be adapted to any type of nanoparticle.

  10. Clean Industrial Room for Drift Tube Assembling

    E-print Network

    Glonti, GL; Evtoukhovitch, P G; Kroa, G; Manz, A; Potrap, I N; Rihter, P; Stoletov, G D; Tskhadadze, E G; Chepurnov, V F; Chirkov, A V; Shelkov, G A

    2001-01-01

    Description of a clean industrial room for assembly of drift tubes for the muon spectrometer of the ATLAS experiment is presented. High quality specifications on the detectors to be produced demanded creation of a workplace with stable temperature and humidity, as well as minimum quantity of dust in the room. Checking of parameters of intra-room air during long period of continuous work has been confirmed correctness of the designed characteristics of the climatic system installed in the clean room. The room large volum (\\sim 190 m^3), the powerful and flexible climatic system, and simplicity of service allow assembling of detectors with length up to 5 m. Subsequent checking of functionality of the assembled detectors has shown high quality of assembling (the amount of rejected tubes does not exceed 2 %). It demonstrates conformity to the assembling quality requirements for mass production of drift chambers for the muon spectrometer.

  11. Modular fuel-cell stack assembly

    DOEpatents

    Patel, Pinakin (Danbury, CT)

    2010-07-13

    A fuel cell assembly having a plurality of fuel cells arranged in a stack. An end plate assembly abuts the fuel cell at an end of said stack. The end plate assembly has an inlet area adapted to receive an exhaust gas from the stack, an outlet area and a passage connecting the inlet area and outlet area and adapted to carry the exhaust gas received at the inlet area from the inlet area to the outlet area. A further end plate assembly abuts the fuel cell at a further opposing end of the stack. The further end plate assembly has a further inlet area adapted to receive a further exhaust gas from the stack, a further outlet area and a further passage connecting the further inlet area and further outlet area and adapted to carry the further exhaust gas received at the further inlet area from the further inlet area to the further outlet area.

  12. Assembly technology of 4-side buttable MPPC

    NASA Astrophysics Data System (ADS)

    Yamamoto, K.; Sato, K.; Yamada, R.; Hosokawa, N.; Nagano, T.; Hayatsu, K.; Shimohara, T.; Ohkuwa, Y.; Oguri, A.

    2013-12-01

    The multi-pixel photon counter (MPPC) is a solid-state photon counting device consisting of a Geiger-mode APD and a quenching resistor. Through-silicon via technology (TSV) allows for the production of a discrete array version of the MPPC, creating a detector with the advantages of a larger active area and less dead space in its overall packaging when compared to other package types commonly used to produce MPPCs. Eliminating the need for a wire-bonding pad allows individual MPPCs to be tiled with minimum dead-space between individual detectors to form a four-sided buttable array. Selecting MPPCs that behave and perform very similarly to each other, especially when an operating voltage is applied, minimizes variation in performance between each channel and enhances channel uniformity. The output of discrete arrays of MPPCs can be easily readout with ASICs (application specific integrated circuits) due to their excellent channel uniformity characteristics, with minimum adjustment required by the ASIC. TSV-MPPC and assembly technology are developed. TSV-MPPC array is tiled in 4-sided buttable and has large and dense active area. The output pulse of MPPC may have sharp rising edge by virtue of TSV. The uniformity of the array can be maximized by neat inspection technology.

  13. Apparatus for electrohydrodynamically assembling patterned colloidal structures

    NASA Technical Reports Server (NTRS)

    Trau, Mathias (Inventor); Aksay, Ilhan A. (Inventor); Saville, Dudley A. (Inventor)

    2000-01-01

    A method apparatus is provided for electrophoretically depositing particles onto an electrode, and electrohydrodynamically assembling the particles into crystalline structures. Specifically, the present method and apparatus creates a current flowing through a solution to cause identically charged electrophoretically deposited colloidal particles to attract each other over very large distances (<5 particle diameters) on the surface of electrodes to form two-dimensional colloidal crystals. The attractive force can be created with both DC and AC fields and can modulated by adjusting either the field strength or frequency of the current. Modulating this lateral attraction between the particles causes the reversible formation of two-dimensional fluid and crystalline colloidal states on the electrode surface. Further manipulation allows for the formation of two or three-dimensional colloidal crystals, as well as more complex designed structures. Once the required structures are formed, these three-dimension colloidal crystals can be permanently frozen or glued by controlled coagulation induced by to the applied field to form a stable crystalline structure.

  14. Sensitizer-catalyst assemblies for water oxidation.

    PubMed

    Wang, Lei; Mirmohades, Mohammad; Brown, Allison; Duan, Lele; Li, Fusheng; Daniel, Quentin; Lomoth, Reiner; Sun, Licheng; Hammarström, Leif

    2015-03-16

    Two molecular assemblies with one Ru(II)-polypyridine photosensitizer covalently linked to one Ru(II)(bda)L2 catalyst (1) (bda = 2,2'-bipyridine-6,6'-dicarboxylate) and two photosensitizers covalently linked to one catalyst (2) have been prepared using a simple C-C bond as the linkage. In the presence of sodium persulfate as a sacrificial electron acceptor, both of them show high activity for catalytic water oxidation driven by visible light, with a turnover number up to 200 for 2. The linked photocatalysts show a lower initial yield for light driven oxygen evolution but a much better photostability compared to the three component system with separate sensitizer, catalyst and acceptor, leading to a much greater turnover number. Photocatalytic experiments and time-resolved spectroscopy were carried out to probe the mechanism of this catalysis. The linked catalyst in its Ru(II) state rapidly quenches the sensitizer, predominantly by energy transfer. However, a higher stability under photocatalytic condition is shown for the linked sensitizer compared to the three component system, which is attributed to kinetic stabilization by rapid photosensitizer regeneration. Strategies for employment of the sensitizer-catalyst molecules in more efficient photocatalytic systems are discussed. PMID:25700086

  15. Automated Solar Module Assembly Line

    NASA Technical Reports Server (NTRS)

    Bycer, M.

    1979-01-01

    The gathering of information that led to the design approach of the machine, and a summary of the findings in the areas of study along with a description of each station of the machine are discussed. The machine is a cell stringing and string applique machine which is flexible in design, capable of handling a variety of cells and assembling strings of cells which can then be placed in a matrix up to 4 ft x 2 ft. in series or parallel arrangement. The target machine cycle is to be 5 seconds per cell. This machine is primarily adapted to 100 MM round cells with one or two tabs between cells. It places finished strings of up to twelve cells in a matrix of up to six such strings arranged in series or in parallel.

  16. Low inductance power electronics assembly

    DOEpatents

    Herron, Nicholas Hayden; Mann, Brooks S.; Korich, Mark D.; Chou, Cindy; Tang, David; Carlson, Douglas S.; Barry, Alan L.

    2012-10-02

    A power electronics assembly is provided. A first support member includes a first plurality of conductors. A first plurality of power switching devices are coupled to the first support member. A first capacitor is coupled to the first support member. A second support member includes a second plurality of conductors. A second plurality of power switching devices are coupled to the second support member. A second capacitor is coupled to the second support member. The first and second pluralities of conductors, the first and second pluralities of power switching devices, and the first and second capacitors are electrically connected such that the first plurality of power switching devices is connected in parallel with the first capacitor and the second capacitor and the second plurality of power switching devices is connected in parallel with the second capacitor and the first capacitor.

  17. Diverter assembly for radioactive material

    DOEpatents

    Andrews, K.M.; Starenchak, R.W.

    1988-04-11

    A diverter assembly for diverting a pneumatically conveyed holder for a radioactive material between a central conveying tube and one of a plurality of radially offset conveying tubes includes an airtight container. A diverter tube having an offset end is suitably mounted in the container for rotation. A rotary seal seals one end of the diverter tube during and after rotation of the diverter tube while a spring biased seal seals the other end of the diverter tube which moves between various offset conveying tubes. An indexing device rotatably indexes the diverter tube and this indexing device is driven by a suitable drive. The indexing mechanism is preferably a geneva-type mechanism to provide a locking of the diverter tube in place. 3 figs.

  18. Modular assembly of optical nanocircuits.

    PubMed

    Shi, Jinwei; Monticone, Francesco; Elias, Sarah; Wu, Yanwen; Ratchford, Daniel; Li, Xiaoqin; Alù, Andrea

    2014-01-01

    A key element enabling the microelectronic technology advances of the past decades has been the conceptualization of complex circuits with versatile functionalities as being composed of the proper combination of basic 'lumped' circuit elements (for example, inductors and capacitors). In contrast, modern nanophotonic systems are still far from a similar level of sophistication, partially because of the lack of modularization of their response in terms of basic building blocks. Here we demonstrate the design, assembly and characterization of relatively complex photonic nanocircuits by accurately positioning a number of metallic and dielectric nanoparticles acting as modular lumped elements. The nanoparticle clusters produce the desired spectral response described by simple circuit rules and are shown to be dynamically reconfigurable by modifying the direction or polarization of impinging signals. Our work represents an important step towards extending the powerful modular design tools of electronic circuits into nanophotonic systems. PMID:24871450

  19. Miniature MT optical assembly (MMTOA)

    DOEpatents

    Laughlin, Daric (Overland Park, KS); Abel, Phillip (Overland Park, KS)

    2008-04-01

    An optical assembly (10) includes a rigid mount (12) with a recess (26) proximate a first side thereof, a substrate (14), and an optical die (16) flip-chip bonded to the substrate (14). The substrate (14) is secured to the first side of the mount and includes a plurality of die bonding elements (40), a plurality of optical apertures (32), and a plurality of external bonding elements (42). A plurality of traces (44) interconnect the die bonding elements (40) and the external bonding elements (42). The optical die (16) includes a plurality of optical elements, each element including an optical signal interface (48), the die being bonded to the plurality of die bonding elements (40) such that the optical signal interface (48) of each element is in registry with an optical aperture (32) of the substrate (14) and the die (16) is at least partially enclosed by the recess (26).

  20. High temperature control rod assembly

    DOEpatents

    Vollman, Russell E. (Solana Beach, CA)

    1991-01-01

    A high temperature nuclear control rod assembly comprises a plurality of substantially cylindrical segments flexibly joined together in succession by ball joints. The segments are made of a high temperature graphite or carbon-carbon composite. The segment includes a hollow cylindrical sleeve which has an opening for receiving neutron-absorbing material in the form of pellets or compacted rings. The sleeve has a threaded sleeve bore and outer threaded surface. A cylindrical support post has a threaded shaft at one end which is threadably engaged with the sleeve bore to rigidly couple the support post to the sleeve. The other end of the post is formed with a ball portion. A hollow cylindrical collar has an inner threaded surface engageable with the outer threaded surface of the sleeve to rigidly couple the collar to the sleeve. the collar also has a socket portion which cooperates with the ball portion to flexibly connect segments together to form a ball and socket-type joint. In another embodiment, the segment comprises a support member which has a threaded shaft portion and a ball surface portion. The threaded shaft portion is engageable with an inner threaded surface of a ring for rigidly coupling the support member to the ring. The ring in turn has an outer surface at one end which is threadably engageably with a hollow cylindrical sleeve. The other end of the sleeve is formed with a socket portion for engagement with a ball portion of the support member. In yet another embodiment, a secondary rod is slidably inserted in a hollow channel through the center of the segment to provide additional strength. A method for controlling a nuclear reactor utilizing the control rod assembly is also included.

  1. Self-assembly and structural evolvement of polyoxometalate-anchored dendron complexes.

    PubMed

    Yang, Yang; Wang, Yizhan; Li, Haolong; Li, Wen; Wu, Lixin

    2010-07-19

    A cationic dendritic molecule that has alkyl chains has been synthesized and employed to encapsulate anionic polyoxometalates through electrostatic interactions. The prepared surfactant-encapsulated polyoxometalate (SEP) complexes were used as building blocks to fabricate self-assemblies in solution and the solid state. Monodispersion, lamellar, and columnar assemblies of SEP complexes have been characterized in detail. With increasing the number of peripheral cationic dendrons on inorganic clusters, the SEPs undergo changes from globular assemblies to monodispersions in solution and from lamellar assemblies to hexagonal columnar structures in the solid state, depending on the amounts of cationic dendrons in the complexes. The structural evolvement was simulated through consideration of the size and shape of the cationic dendron and polyanionic clusters, and the experimental results are in good agreement with the interpretation of the simulations. The present research demonstrates a new kind of dendritic complex and provides a route for controlling their assembling states by simply alternating the number of cationic dendrons in the complexes. PMID:20564290

  2. Development of a machine vision system for automated structural assembly

    NASA Technical Reports Server (NTRS)

    Sydow, P. Daniel; Cooper, Eric G.

    1992-01-01

    Research is being conducted at the LaRC to develop a telerobotic assembly system designed to construct large space truss structures. This research program was initiated within the past several years, and a ground-based test-bed was developed to evaluate and expand the state of the art. Test-bed operations currently use predetermined ('taught') points for truss structural assembly. Total dependence on the use of taught points for joint receptacle capture and strut installation is neither robust nor reliable enough for space operations. Therefore, a machine vision sensor guidance system is being developed to locate and guide the robot to a passive target mounted on the truss joint receptacle. The vision system hardware includes a miniature video camera, passive targets mounted on the joint receptacles, target illumination hardware, and an image processing system. Discrimination of the target from background clutter is accomplished through standard digital processing techniques. Once the target is identified, a pose estimation algorithm is invoked to determine the location, in three-dimensional space, of the target relative to the robots end-effector. Preliminary test results of the vision system in the Automated Structural Assembly Laboratory with a range of lighting and background conditions indicate that it is fully capable of successfully identifying joint receptacle targets throughout the required operational range. Controlled optical bench test results indicate that the system can also provide the pose estimation accuracy to define the target position.

  3. Columnar organization of stack-assembled trimesic acid on graphene

    NASA Astrophysics Data System (ADS)

    Shayeganfar, F.

    2014-10-01

    The stack-assembly of trimesic acid molecules into a highly organized columnar structure and their adsorption on graphene has been investigated by a DFT-based ab initio calculation method. Trimesic acid (TMA, benzene-1,3,5-tricarboxylic acid) constitutes an interesting building block for intermolecular hydrogen-bonding architecture by creating a strong net dipole moment which favors a symmetric ?-stacking of molecular wire. Both the single orientation (syn) and alternating orientation (anti) of two- and three-unit TMA configurations are optimized, and determine that anti or AB pattern TMA wire is energetically more favorable than the syn case. Meanwhile, a decreasing band gap during the formation of the molecular wire proves the presence of delocalized ?-electrons over the entire stack-assembly. The adsorption energy for a columnar TMA stack on graphene was found to be roughly less than of a single TMA adsorbed on graphene. The relative contribution of hydrogen bonding to column packing energy showed to be comparative and reasonable, with the energy of a conventional hydrogen bond. The magnitude of the band gap opening appears strongly correlated with the breaking of the symmetry of ?-states of graphene by the TMA columnar patterning on the surface. Our results suggest that a stack-assembled molecular could be used to tune and control the electronic properties of graphene.

  4. Interference assembly and fretting wear analysis of hollow shaft.

    PubMed

    Han, Chuanjun; Zhang, Jie

    2014-01-01

    Fretting damage phenomenon often appears in the interference fit assembly. The finite element model of hollow shaft and shaft sleeve was established, and the equivalent stress and contact stress were computed after interference assembly. The assembly body of hollow shaft and shaft sleeve was in whirling bending load, and the contact status (sticking, sliding, and opening) and the distribution of stress along one typical contact line were computed under different loads, interferences, hollow degrees, friction coefficient, and wear quantity. Judgment formula of contact state was fixed by introducing the corrected coefficient k. The computation results showed that the "edge effect" appears in the contact surface after interference fit. The size of slip zone is unchanged along with the increase of bending load. The greater the interference value, the bigger the wear range. The hollow degree does not influence the size of stick zone but controls the position of the junction point of slip-open. Tangential contact stress increases with the friction coefficient, which has a little effect on normal contact stress. The relationship between open size and wear capacity is approximately linear. PMID:24955422

  5. The perennial organelle: assembly and disassembly of the primary cilium

    PubMed Central

    Seeley, E. Scott; Nachury, Maxence V.

    2010-01-01

    Primary cilia contain signaling receptors of diverse classes, and ciliary dysfunction results in a variety of developmental defects. Thus, primary cilia are thought to have an important role in sensing and transducing cellular signals. Although there is clear evidence demonstrating that these organelles are assembled and disassembled dynamically as cells progress through the cell cycle, the mechanisms by which the cell cycle controls the assembly and disassembly of the primary cilium remain poorly understood. In this Commentary, we review the basic cellular mechanisms that underlie the early stages of cilium assembly and discuss how the cell cycle communicates with the ciliation program. A commonly held view is that ciliation occurs exclusively in cells that have exited the cell cycle and entered quiescence or differentiation. However, this concept is at odds with the finding that, during development, many actively proliferating cells require cilia-mediated signaling pathways to instruct their developmental fate. Here, we reassess the quiescence-centric view of ciliation by reviewing historic and current literature. We discuss ample evidence that cilia are in fact present on many proliferating cells, and that a transient peak of ciliation before the G1-S transition might be tightly coupled to entry into the DNA replication phase. Finally, we touch on the relationship between the ciliation and cell-division cycles and the tissue distribution of primary cilia in order to highlight potential roles for the primary cilium in restraining cells from the hyperproliferative state that contributes to cancer. PMID:20144999

  6. Redesigning assembly stations using ergonomic methods as a lean tool.

    PubMed

    Eswaramoorthi, M; John, Mervyn; Rajagopal, C Arjun; Prasad, P S S; Mohanram, P V

    2010-01-01

    With the current state of the global economy, demand for various products plummeting. To sustain in the market, companies have to reduce cost and improve quality. Today, companies have started implementing new philosophies like TQM, TPM, six sigma and lean manufacturing techniques to remain competitive in the market. Lean manufacturing is an emerging philosophy which continuously strives to reduce waste. The main objective of analyzing the assembly line with a lean perspective is to identify the areas related to human interface with other systems that could lead to the generation of waste. Improper workplace design leads to unreasonable mental or physical burden and results in waste generation like slow work (delay and inventory), and defects, which is named as muri waste. An attempt has been made in this paper to locate muri waste and create a "Lean assembly line". The proposed method, based on the use of Rapid Upper Limb Assessment (RULA) with CATIA V5 platform, has allowed the measurement of a large set of operator posture parameters and assessment of ergonomic stresses. Based on the results, the process stations in the assembly line were redesigned to prevent the generation of waste. PMID:20164618

  7. Assembly history dictates ecosystem functioning: evidence from wood decomposer communities

    E-print Network

    Bruns, Tom

    Allen, Robert; Landcare Research Key Words: assembly rules, biodiversity, carbon sequestration, climate, biodiversity, carbon sequestration, climate change, community assembly, ecosystem functioning, New Zealand

  8. Self-Assembly of biologically inspired complex functional materials.

    SciTech Connect

    Brinker, C. Jeffrey

    2004-08-01

    Nature combines hard and soft materials, often in hierarchical architectures, to get synergistic, optimized properties with proven, complex functionalities. Emulating such natural designs in robust engineering materials using efficient processing approaches represents a fundamental challenge to materials chemists. This presentation will review progress on understanding so-called 'evaporation-induced silica/surfactant self-assembly' (EISA) as a simple, general means to prepare porous thin-film nanostructures. Such porous materials are of interest for membranes, low-dielectric-constant (low-k) insulators, and even 'nano-valves' that open and close in response to an external stimulus. EISA can also be used to simultaneously organize hydrophilic and hydrophobic precursors into hybrid nanocomposites that are optically or chemically polymerizable, patternable, or adjustable. In constructing composite structures, a significant challenge is how to controllably organize or define multiple materials on multiple length scales. To address this challenge, we have combined sol-gel chemistry with molecular self-assembly in several evaporation-driven processing procedures collectively referred to as evaporation-induced self-assembly (EISA). EISA starts with a silica/water/surfactant system diluted with ethanol to create a homogeneous solution. We rely on ethanol and water evaporation during dip-coating (or other coating methods) to progressively concentrate surfactant and silica in the depositing film, driving micelle formation and subsequent continuous self-assembly of silica/surfactant thin film mesophases. One of the crucial aspects of this process, in terms of the sol-gel chemistry, is to work under conditions where the condensation rate of the hydrophilic silicic acid precursors (Si-OH) is minimized. The idea is to avoid gelation that would kinetically trap the system at an intermediate non-equilibrium state. We want the structure to self-assemble then solidify, with the addition of a siloxane condensation catalyst or by heating, to form the desired mesostructured product. Operating at an acidic pH (pH = 2) minimizes the condensation rate of silanols to form siloxanes Si-O-SiIn addition, hydrogen bonding and electrostatic interactions between silanols and hydrophilic surfactant head groups can further reduce the condensation rate. These combined factors maintain the depositing film in a fluid state, even beyond the point where ethanol and water are largely evaporated. This allows the deposited film to be self-healing and enables the use of virtually any evaporation-driven process (spin-coating, inkjet printing, or aerosol processing) to create ordered nanostructured films, patterns, or particles.

  9. Advances in cryogenic transmission electron microscopy for the characterization of dynamic self-assembling nanostructures.

    PubMed

    Newcomb, Christina J; Moyer, Tyson J; Lee, Sungsoo S; Stupp, Samuel I

    2012-12-01

    Elucidating the structural information of nanoscale materials in their solvent-exposed state is crucial, as a result, cryogenic transmission electron microscopy (cryo-TEM) has become an increasingly popular technique in the materials science, chemistry, and biology communities. Cryo-TEM provides a method to directly visualize the specimen structure in a solution-state through a thin film of vitrified solvent. This technique complements X-ray, neutron, and light scattering methods that probe the statistical average of all species present; furthermore, cryo-TEM can be used to observe changes in structure over time. In the area of self-assembly, this tool has been particularly powerful for the characterization of natural and synthetic small molecule assemblies, as well as hybrid organic-inorganic composites. In this review, we discuss recent advances in cryogenic TEM in the context of self-assembling systems with emphasis on characterization of transitions observed in response to external stimuli. PMID:23204913

  10. Advances in cryogenic transmission electron microscopy for the characterization of dynamic self-assembling nanostructures

    PubMed Central

    Newcomb, Christina J.; Moyer, Tyson J.; Lee, Sungsoo S.; Stupp, Samuel I.

    2012-01-01

    Elucidating the structural information of nanoscale materials in their solvent-exposed state is crucial, as a result, cryogenic transmission electron microscopy (cryo-TEM) has become an increasingly popular technique in the materials science, chemistry, and biology communities. Cryo-TEM provides a method to directly visualize the specimen structure in a solution-state through a thin film of vitrified solvent. This technique complements X-ray, neutron, and light scattering methods that probe the statistical average of all species present; furthermore, cryo-TEM can be used to observe changes in structure over time. In the area of self-assembly, this tool has been particularly powerful for the characterization of natural and synthetic small molecule assemblies, as well as hybrid organic–inorganic composites. In this review, we discuss recent advances in cryogenic TEM in the context of self-assembling systems with emphasis on characterization of transitions observed in response to external stimuli. PMID:23204913

  11. Dynamic Phases, Pinning, and Pattern Formation for Driven Dislocation Assemblies

    PubMed Central

    Zhou, Caizhi; Reichhardt, Charles; Olson Reichhardt, Cynthia J.; Beyerlein, Irene J.

    2015-01-01

    We examine driven dislocation assemblies and show that they can exhibit a set of dynamical phases remarkably similar to those of driven systems with quenched disorder such as vortices in superconductors, magnetic domain walls, and charge density wave materials. These phases include pinned-jammed, fluctuating, and dynamically ordered states, and each produces distinct dislocation patterns as well as specific features in the noise fluctuations and transport properties. Our work suggests that many of the results established for systems with quenched disorder undergoing plastic depinning transitions can be applied to dislocation systems, providing a new approach for understanding pattern formation and dynamics in these systems. PMID:25613839

  12. Halo Assembly Bias in Hierarchical Structure Formation

    E-print Network

    Neal Dalal; Martin White; J. Richard Bond; Alexander Shirokov

    2008-03-25

    We investigate the origin of halo assembly bias, the dependence of halo clustering on assembly history. We relate halo assembly to peak properties measured in the Lagrangian space of the initial linear Gaussian random density field, and show how these same Lagrangian properties determine large-scale bias. We focus on the two regimes where assembly bias has been observed to be significant: at masses very large and very small compared to the nonlinear mass scale. At high masses, we show that assembly bias is expected from the statistics of the peaks of Gaussian random fluctuations, and we show that the extent of assembly bias found in N-body simulations of rare halos is in excellent agreement with our theoretical prediction. At low masses, we argue that assembly bias largely arises from a sub-population of low mass halos whose mass accretion has ceased. Due to their arrested development, these halos naturally become unbiased, in contrast to their anti-biased peers. We show that a simple toy model incorporating these effects can roughly reproduce the bias trends found in N-body simulations.

  13. Patterns and Processes of Microbial Community Assembly

    PubMed Central

    Schmidt, Steven K.; Fukami, Tadashi; O'Neill, Sean P.; Bilinski, Teresa M.; Stanish, Lee F.; Knelman, Joseph E.; Darcy, John L.; Lynch, Ryan C.; Wickey, Phillip; Ferrenberg, Scott

    2013-01-01

    SUMMARY Recent research has expanded our understanding of microbial community assembly. However, the field of community ecology is inaccessible to many microbial ecologists because of inconsistent and often confusing terminology as well as unnecessarily polarizing debates. Thus, we review recent literature on microbial community assembly, using the framework of Vellend (Q. Rev. Biol. 85:183–206, 2010) in an effort to synthesize and unify these contributions. We begin by discussing patterns in microbial biogeography and then describe four basic processes (diversification, dispersal, selection, and drift) that contribute to community assembly. We also discuss different combinations of these processes and where and when they may be most important for shaping microbial communities. The spatial and temporal scales of microbial community assembly are also discussed in relation to assembly processes. Throughout this review paper, we highlight differences between microbes and macroorganisms and generate hypotheses describing how these differences may be important for community assembly. We end by discussing the implications of microbial assembly processes for ecosystem function and biodiversity. PMID:24006468

  14. Assembly of the 20S Proteasome

    PubMed Central

    Kunjappu, Mary J.; Hochstrasser, Mark

    2013-01-01

    The proteasome is a cellular protease responsible for the selective degradation of the majority of the intracellular proteome. It recognizes, unfolds, and cleaves proteins that are destined for removal, usually by prior attachment to polymers of ubiquitin. This macromolecular machine is composed of two subcomplexes, the 19S regulatory particle (RP) and the 20S core particle (CP), which together contain at least 33 different and precisely positioned subunits. How these subunits assemble into functional complexes is an area of active exploration. Here we describe the current status of studies on the assembly of the 20S proteasome (CP). The 28-subunit CP is found in all three domains of life and its cylindrical stack of four heptameric rings is well conserved. Though several CP subunits possess self-assembly properties, a consistent theme in recent years has been the need for dedicated assembly chaperones that promote on-pathway assembly. To date, a minimum of three accessory factors have been implicated in aiding the construction of the 20S proteasome. These chaperones interact with different assembling proteasomal precursors and usher subunits into specific slots in the growing structure. This review will focus largely on chaperone-dependent CP assembly and its regulation. PMID:23507199

  15. Flashback resistant pre-mixer assembly

    DOEpatents

    Laster, Walter R. (Oviedo, FL); Gambacorta, Domenico (Oviedo, FL)

    2012-02-14

    A pre-mixer assembly associated with a fuel supply system for mixing of air and fuel upstream from a main combustion zone in a gas turbine engine. The pre-mixer assembly includes a swirler assembly disposed about a fuel injector of the fuel supply system and a pre-mixer transition member. The swirler assembly includes a forward end defining an air inlet and an opposed aft end. The pre-mixer transition member has a forward end affixed to the aft end of the swirler assembly and an opposed aft end defining an outlet of the pre-mixer assembly. The aft end of the pre-mixer transition member is spaced from a base plate such that a gap is formed between the aft end of the pre-mixer transition member and the base plate for permitting a flow of purge air therethrough to increase a velocity of the air/fuel mixture exiting the pre-mixer assembly.

  16. Emerging Technologies for Assembly of Microscale Hydrogels

    PubMed Central

    Kavaz, Doga; Demirel, Melik C.; Demirci, Utkan

    2013-01-01

    Assembly of cell encapsulating building blocks (i.e., microscale hydrogels) has significant applications in areas including regenerative medicine, tissue engineering, and cell-based in vitro assays for pharmaceutical research and drug discovery. Inspired by the repeating functional units observed in native tissues and biological systems (e.g., the lobule in liver, the nephron in kidney), assembly technologies aim to generate complex tissue structures by organizing microscale building blocks. Novel assembly technologies enable fabrication of engineered tissue constructs with controlled properties including tunable microarchitectural and predefined compositional features. Recent advances in micro- and nano-scale technologies have enabled engineering of microgel based three dimensional (3D) constructs. There is a need for high-throughput and scalable methods to assemble microscale units with a complex 3D micro-architecture. Emerging assembly methods include novel technologies based on microfluidics, acoustic and magnetic fields, nanotextured surfaces, and surface tension. In this review, we survey emerging microscale hydrogel assembly methods offering rapid, scalable microgel assembly in 3D, and provide future perspectives and discuss potential applications. PMID:23184717

  17. Directed Self-Assembly of Nanodispersions

    SciTech Connect

    Furst, Eric M [University of Delaware] [University of Delaware

    2013-11-15

    Directed self-assembly promises to be the technologically and economically optimal approach to industrial-scale nanotechnology, and will enable the realization of inexpensive, reproducible and active nanostructured materials with tailored photonic, transport and mechanical properties. These new nanomaterials will play a critical role in meeting the 21st century grand challenges of the US, including energy diversity and sustainability, national security and economic competitiveness. The goal of this work was to develop and fundamentally validate methods of directed selfassembly of nanomaterials and nanodispersion processing. The specific aims were: 1. Nanocolloid self-assembly and interactions in AC electric fields. In an effort to reduce the particle sizes used in AC electric field self-assembly to lengthscales, we propose detailed characterizations of field-driven structures and studies of the fundamental underlying particle interactions. We will utilize microscopy and light scattering to assess order-disorder transitions and self-assembled structures under a variety of field and physicochemical conditions. Optical trapping will be used to measure particle interactions. These experiments will be synergetic with calculations of the particle polarizability, enabling us to both validate interactions and predict the order-disorder transition for nanocolloids. 2. Assembly of anisotropic nanocolloids. Particle shape has profound effects on structure and flow behavior of dispersions, and greatly complicates their processing and self-assembly. The methods developed to study the self-assembled structures and underlying particle interactions for dispersions of isotropic nanocolloids will be extended to systems composed of anisotropic particles. This report reviews several key advances that have been made during this project, including, (1) advances in the measurement of particle polarization mechanisms underlying field-directed self-assembly, and (2) progress in the directed self-assembly of anisotropic nanoparticles and their unique physical properties.

  18. The MaSuRCA genome assembler

    PubMed Central

    Zimin, Aleksey V.; Marçais, Guillaume; Puiu, Daniela; Roberts, Michael; Salzberg, Steven L.; Yorke, James A.

    2013-01-01

    Motivation: Second-generation sequencing technologies produce high coverage of the genome by short reads at a low cost, which has prompted development of new assembly methods. In particular, multiple algorithms based on de Bruijn graphs have been shown to be effective for the assembly problem. In this article, we describe a new hybrid approach that has the computational efficiency of de Bruijn graph methods and the flexibility of overlap-based assembly strategies, and which allows variable read lengths while tolerating a significant level of sequencing error. Our method transforms large numbers of paired-end reads into a much smaller number of longer ‘super-reads’. The use of super-reads allows us to assemble combinations of Illumina reads of differing lengths together with longer reads from 454 and Sanger sequencing technologies, making it one of the few assemblers capable of handling such mixtures. We call our system the Maryland Super-Read Celera Assembler (abbreviated MaSuRCA and pronounced ‘mazurka’). Results: We evaluate the performance of MaSuRCA against two of the most widely used assemblers for Illumina data, Allpaths-LG and SOAPdenovo2, on two datasets from organisms for which high-quality assemblies are available: the bacterium Rhodobacter sphaeroides and chromosome 16 of the mouse genome. We show that MaSuRCA performs on par or better than Allpaths-LG and significantly better than SOAPdenovo on these data, when evaluated against the finished sequence. We then show that MaSuRCA can significantly improve its assemblies when the original data are augmented with long reads. Availability: MaSuRCA is available as open-source code at ftp://ftp.genome.umd.edu/pub/MaSuRCA/. Previous (pre-publication) releases have been publicly available for over a year. Contact: alekseyz@ipst.umd.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:23990416

  19. Dynamics of HIV-1 Assembly and Release

    PubMed Central

    Ivanchenko, Sergey; Godinez, William J.; Lampe, Marko; Kräusslich, Hans-Georg; Eils, Roland; Rohr, Karl; Bräuchle, Christoph; Müller, Barbara; Lamb, Don C.

    2009-01-01

    Assembly and release of human immunodeficiency virus (HIV) occur at the plasma membrane of infected cells and are driven by the Gag polyprotein. Previous studies analyzed viral morphogenesis using biochemical methods and static images, while dynamic and kinetic information has been lacking until very recently. Using a combination of wide-field and total internal reflection fluorescence microscopy, we have investigated the assembly and release of fluorescently labeled HIV-1 at the plasma membrane of living cells with high time resolution. Gag assembled into discrete clusters corresponding to single virions. Formation of multiple particles from the same site was rarely observed. Using a photoconvertible fluorescent protein fused to Gag, we determined that assembly was nucleated preferentially by Gag molecules that had recently attached to the plasma membrane or arrived directly from the cytosol. Both membrane-bound and cytosol derived Gag polyproteins contributed to the growing bud. After their initial appearance, assembly sites accumulated at the plasma membrane of individual cells over 1–2 hours. Assembly kinetics were rapid: the number of Gag molecules at a budding site increased, following a saturating exponential with a rate constant of ?5×10?3 s?1, corresponding to 8–9 min for 90% completion of assembly for a single virion. Release of extracellular particles was observed at ?1,500±700 s after the onset of assembly. The ability of the virus to recruit components of the cellular ESCRT machinery or to undergo proteolytic maturation, or the absence of Vpu did not significantly alter the assembly kinetics. PMID:19893629

  20. Co-assembly of polymer covered cyclic peptide nanotubes and block copolymer in thin films

    NASA Astrophysics Data System (ADS)

    Zhang, Chen; Lazzara, Thomas; Li, Changyi; Helmes, Brett; Xu, Ting

    2013-03-01

    Nanotubular structures have gained prevalent interest for their unique hollow structures and high aspect ratio and their potential applications ranging from molecular separation to nanocomposite membranes. We used nanotube forming cyclic peptide (CP) as the structural motif and studied the self-assembly of polymer conjugated CPs in block copolymer (BCP) matrix in thin films. The co-assembly process is mainly driven by thermodynamic quantities, namely Flory-Huggins polymer-polymer interactions that governs the interaction between CP and BCP, interfacial interactions that affects polymer chain orientation, and thin film commensurability. In addition, due to the dynamic nature of the nanotube formation, the co-assembly process is also pathway-dependent. Thus, processing conditions are critical in co-assembling CP nanotubes and BCP in thin films. Our result shows that the initial aggregation state of polymer covered CP nanotubes determines the pathway the system takes and hence the final morphology of the films. The co-assembly of polymer-conjugated CPs and BCPs demonstrates the feasibility of assembling 1D nanotubes in supramolecular thin films and opens up a new avenue for the generation of novel nanotubular structures.