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1

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

SciTech Connect

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.

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

2

Structure of the 'Escherichia Coli' Leucine-Responsive Regulatory Protein Lrp Reveals a Novel Octameric Assembly  

SciTech Connect

The structure of Escherichia coli leucine-responsive regulatory protein (Lrp) cocrystallized with a short duplex oligodeoxynucleotide reveals a novel quaternary assembly in which the protein octamer forms an open, linear array of four dimers. In contrast, structures of the Lrp homologs LrpA, LrpC and AsnC crystallized in the absence of DNA show that these proteins instead form highly symmetrical octamers in which the four dimers form a closed ring. Although the DNA is disordered within the Lrp crystal, comparative analyses suggest that the observed differences in quaternary state may arise from DNA interactions during crystallization. Interconversion of these conformations, possibly in response to DNA or leucine binding, provides an underlying mechanism to alter the relative spatial orientation of the DNA-binding domains. Breaking of the closed octamer symmetry may be a common essential step in the formation of active DNA complexes by all members of the Lrp/AsnC family of transcriptional regulatory proteins.

de los Rios, S.; Perona, J.J.; /UC, Santa Barbara

2007-07-09

3

Observed octameric assembly of a Plasmodium yoelii peroxiredoxin can be explained by the replacement of native "ball-and-socket" interacting residues by an affinity tag.  

PubMed

Peroxiredoxins (Prxs) are ubiquitous and efficient antioxidant enzymes crucial for redox homeostasis in most organisms, and are of special importance for disease-causing parasites that must protect themselves against the oxidative weapons of the human immune system. Here, we describe reanalyses of crystal structures of two Prxs from malaria parasites. In addition to producing improved structures, we provide normalizing explanations for features that had been noted as unusual in the original report of these structures (Qiu et al., BMC Struct Biol 2012;12:2). Most importantly, we provide evidence that the unusual octameric assembly seen for Plasmodium yoelii Prx1a is not physiologically relevant, but arises because the structure is not of authentic P. yoelii Prx1a, but a variant we designate PyPrx1a(N*) that has seven native N-terminal residues replaced by an affinity tag. This N-terminal modification disrupts a previously unrecognized, hydrophobic "ball-and-socket" interaction conserved at the B-type dimer interface of Prx1 subfamily enzymes, and is accommodated by a fascinating two-residue "?-slip" type register shift in the ?-strand association at a dimer interface. The resulting change in the geometry of the dimer provides a simple explanation for octamer formation. This study illustrates how substantive impacts can occur in protein variants in which native residues have been altered. PMID:23934758

Gretes, Michael C; Karplus, P Andrew

2013-10-01

4

New York State Assembly  

NSDL National Science Digital Library

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.

New York (State). Legislature. Assembly.

1997-01-01

5

Bioconjugation on cube-octameric silsesquioxanes.  

PubMed

Small, compact, and highly symmetric cube-octameric silsesquioxanes have recently attracted increased attention as scaffolds for tailor-made bioconjugates. The expanded arsenal of effective conjugation methods (CuAAC, TEC, oxime ligation) allows one to decorate these nanoparticles bearing up to eight addressable organic substituents, with a wide range of biorelevant ligands, among them carbohydrates, peptides, miniproteins, reporter molecules, and rare-earth chelates. Low toxicity of COSS-based molecules combined with solubility in aqueous systems and half-life sufficient for in vivo studies make these structures attractive targets for a number of applications, among them drug delivery, tumor diagnostics and therapy. PMID:23303331

Fabritz, Sebastian; Hörner, Sebastian; Avrutina, Olga; Kolmar, Harald

2013-04-14

6

Octameric CENP-A nucleosomes are present at human centromeres throughout the cell cycle.  

PubMed

The presence of a single centromere on each chromosome that signals formation of a mitotic kinetochore is central to accurate chromosome segregation. The histone H3 variant centromere protein-A (CENP-A) is critical for centromere identity and function; CENP-A chromatin acts as an epigenetic mark to direct both centromere and kinetochore assembly. Interpreting the centromere epigenetic mark ensures propagation of a single centromere per chromosome to maintain ploidy. Thus, understanding the nature of CENP-A chromatin is crucial for all cell divisions. However, there are ongoing debates over the fundamental composition of centromeric chromatin. Here we show that natively assembled human CENP-A nucleosomes are octameric throughout the cell cycle. Using total internal reflection fluorescence (TIRF)-coupled photobleaching-assisted copy-number counting of single nucleosomes obtained from cultured cells, we find that the majority of CENP-A nucleosomes contain CENP-A dimers. In addition, we detect the presence of H2B and H4 in these nucleosomes. Surprisingly, CENP-A associated with the chaperone HJURP can exist as either monomer or dimer, indicating possible assembly intermediates. Thus, our findings indicate that octameric CENP-A nucleosomes mark the centromeric region to ensure proper epigenetic inheritance and kinetochore assembly. PMID:23623556

Padeganeh, Abbas; Ryan, Joël; Boisvert, Jacques; Ladouceur, Anne-Marie; Dorn, Jonas F; Maddox, Paul S

2013-04-25

7

From pico to nano: biofunctionalization of cube-octameric silsesquioxanes by peptides and miniproteins.  

PubMed

Polyhedral silsesquioxanes are considered valuable conjugation scaffolds. Nevertheless, only a few examples of silsesquioxane-assembled peptide oligomers have been reported to date. We developed a new bioorthogonal cube-octameric silsesquioxane (COSS) scaffold bearing eight aminooxy coupling sites allowing for the conjugation of diverse peptides via oxime ligation. We found that the coupling efficacy depends on the ligand in view of steric hindrance and electrostatic repulsion. For the first time scaffold-based conjugation of cystine-knot miniproteins having a backbone of about thirty amino acids was successfully accomplished without loss of bioactivity. Atomic force microscopy (AFM) provided further knowledge on the size of COSS verifying them as picoscaffolds growing upon bioconjugation to nano-dimension. PMID:22733169

Fabritz, Sebastian; Hörner, Sebastian; Könning, Doreen; Empting, Martin; Reinwarth, Michael; Dietz, Christian; Glotzbach, Bernhard; Frauendorf, Holm; Kolmar, Harald; Avrutina, Olga

2012-06-26

8

Crystal structure of the octameric pore of staphylococcal ?-hemolysin reveals the ?-barrel pore formation mechanism by two components  

PubMed Central

Staphylococcal ?-hemolysin is a bicomponent pore-forming toxin composed of LukF and Hlg2. These proteins are expressed as water-soluble monomers and then assemble into the oligomeric pore form on the target cell. Here, we report the crystal structure of the octameric pore form of ?-hemolysin at 2.5 ? resolution, which is the first high-resolution structure of a ?-barrel transmembrane protein composed of two proteins reported to date. The octameric assembly consists of four molecules of LukF and Hlg2 located alternately in a circular pattern, which explains the biochemical data accumulated over the past two decades. The structure, in combination with the monomeric forms, demonstrates the elaborate molecular machinery involved in pore formation by two different molecules, in which interprotomer electrostatic interactions using loops connecting ?2 and ?3 (loop A: Asp43-Lys48 of LukF and Lys37-Lys43 of Hlg2) play pivotal roles as the structural determinants for assembly through unwinding of the N-terminal ?-strands (amino-latch) of the adjacent protomer, releasing the transmembrane stem domain folded into a ?-sheet in the monomer (prestem), and interaction with the adjacent protomer.

Yamashita, Keitaro; Kawai, Yuka; Tanaka, Yoshikazu; Hirano, Nagisa; Kaneko, Jun; Tomita, Noriko; Ohta, Makoto; Kamio, Yoshiyuki; Yao, Min; Tanaka, Isao

2011-01-01

9

Community assembly: alternative stable states or alternative transient states?  

PubMed Central

The concept of alternative stable states has long been a dominant framework for studying the influence of historical contingency in community assembly. This concept focuses on stable states, yet many real communities are kept in a transient state by disturbance, and the utility of predictions for stable states in explaining transient states remains unclear. Using a simple model of plant community assembly, we show that the conditions under which historical contingency affects community assembly can differ greatly for stable versus transient states. Differences arise because the contribution of such factors as mortality rate, environmental heterogeneity and plant-soil feedback to historical contingency changes as community assembly proceeds. We also show that transient states can last for a long time relative to immigration rate and generation time. These results argue for a conceptual shift of focus from alternative stable states to alternative transient states for understanding historical contingency in community assembly.

Fukami, Tadashi; Nakajima, Mifuyu

2011-01-01

10

Iron Binding at Specific Sites within the Octameric HbpS Protects Streptomycetes from Iron-Mediated Oxidative Stress  

PubMed Central

The soil bacterium Streptomyces reticuli secretes the octameric protein HbpS that acts as a sensory component of the redox-signalling pathway HbpS-SenS-SenR. This system modulates a genetic response on iron- and haem-mediated oxidative stress. Moreover, HbpS alone provides this bacterium with a defence mechanism to the presence of high concentrations of iron ions and haem. While the protection against haem has been related to its haem-binding and haem-degrading activity, the interaction with iron has not been studied in detail. In this work, we biochemically analyzed the iron-binding activity of a set of generated HbpS mutant proteins and present evidence showing the involvement of one internal and two exposed D/EXXE motifs in binding of high quantities of ferrous iron, with the internal E78XXE81 displaying the tightest binding. We additionally show that HbpS is able to oxidize ferrous to ferric iron ions. Based on the crystal structure of both the wild-type and the mutant HbpS-D78XXD81, we conclude that the local arrangement of the side chains from the glutamates in E78XXE81 within the octameric assembly is a pre-requisite for interaction with iron. The data obtained led us to propose that the exposed and the internal motif build a highly specific route that is involved in the transport of high quantities of iron ions into the core of the HbpS octamer. Furthermore, physiological studies using Streptomyces transformants secreting either wild-type or HbpS mutant proteins and different redox-cycling compounds led us to conclude that the iron-sequestering activity of HbpS protects these soil bacteria from the hazardous side effects of peroxide- and iron-based oxidative stress.

Wedderhoff, Ina; Kursula, Inari; Groves, Matthew R.; Ortiz de Orue Lucana, Dario

2013-01-01

11

Octamerization Enables Soluble CD46 Receptor To Neutralize Measles Virus In Vitro and In Vivo  

PubMed Central

A chimeric fusion protein encompassing the CD46 ectodomain linked to the C-terminal part of the C4b binding protein (C4bp) ? chain (sCD46-C4bp?) was produced in eukaryotic cells. This protein, secreted as a disulfide-linked homo-octamer, was recognized by a panel of anti-CD46 antibodies with varying avidities. Unlike monomeric sCD46, the octameric sCD46-C4bp? protein was devoid of complement regulatory activity. However, sCD46-C4bp? was able to bind to the measles virus hemagglutinin protein expressed on murine cells with a higher avidity than soluble monomeric sCD46. Moreover, the octameric sCD46-C4bp? protein was significantly more efficient than monomeric sCD46 in inhibiting virus binding to CD46, in blocking virus induced cell-cell fusion, and in neutralizing measles virus in vitro. In addition, the octameric sCD46-C4bp? protein, but not the monomeric sCD46, fully protected CD46 transgenic mice against a lethal intracranial measles virus challenge.

Christiansen, Dale; Devaux, Patricia; Reveil, Brigitte; Evlashev, Alexey; Horvat, Branka; Lamy, Josette; Rabourdin-Combe, Chantal; Cohen, Jacques H. M.; Gerlier, Denis

2000-01-01

12

Multidomain assembled states of Hck tyrosine kinase in solution  

PubMed Central

An approach combining small-angle X-ray solution scattering (SAXS) data with coarse-grained (CG) simulations is developed to characterize the assembly states of Hck, a member of the Src-family kinases, under various conditions in solution. First, a basis set comprising a small number of assembly states is generated from extensive CG simulations. Second, a theoretical SAXS profile for each state in the basis set is computed by using the Fast-SAXS method. Finally, the relative population of the different assembly states is determined via a Bayesian-based Monte Carlo procedure seeking to optimize the theoretical scattering profiles against experimental SAXS data. The study establishes the concept of basis-set supported SAXS (BSS-SAXS) reconstruction combining computational and experimental techniques. Here, BSS-SAXS reconstruction is used to reveal the structural organization of Hck in solution and the different shifts in the equilibrium population of assembly states upon the binding of different signaling peptides.

Yang, Sichun; Blachowicz, Lydia; Makowski, Lee; Roux, Benoit

2010-01-01

13

Chiral enrichment of serine via formation, dissociation, and soft-landing of octameric cluster ions  

Microsoft Academic Search

Chiral enrichment of serine is achieved in experiments that involve formation of serine octamers starting from non-racemic\\u000a serine solutions. Serine octamers were generated by means of electrospray and sonic spray ionization of aqueous solutions\\u000a of d\\u000a 3-L-serine (108 Da) and D-serine (105 Da) having different molar ratios of enantiomers. A cyclic process involving the formation\\u000a of chirally-enriched octameric cluster ions

Sergio C. Nanita; Zoltan Takats; R. Graham Cooks; Sunnie Myung; David E. Clemmer

2004-01-01

14

Protein-dependent transition states for ribonucleoprotein assembly.  

PubMed

Native folding and splicing by the Saccharomyces cerevisiae mitochondrial bI5 group I intron RNA is facilitated by both the S. cerevisiae CBP2 and Neurospora crassa CYT-18 protein cofactors. Both protein-bI5 RNA complexes splice at similar rates, suggesting that the RNA active site structure is similar in both ribonucleoproteins. In contrast, the two proteins assemble with the bI5 RNA by distinct mechanisms and bind opposing, but partially overlapping, sides of the group I intron catalytic core. Assembly with CBP2 is limited by a slow, unimolecular RNA folding step characterized by a negligible activation enthalpy. We show that assembly with CYT-18 shows four distinctive features. (1) CYT-18 binds stably to the bI5 RNA at the diffusion controlled limit, but assembly to a catalytically active RNA structure is still limited by RNA folding, as visualized directly using time-resolved footprinting. (2) This mechanism of rapid stable protein binding followed by subsequent assembly steps has a distinctive kinetic signature: the apparent ratio of k(off) to k(on), determined in a partitioning experiment, differs from the equilibrium K(d) by a large factor. (3) Assembly with CYT-18 is characterized by a large activation enthalpy, consistent with a rate limiting conformational rearrangement. (4) Because assembly from the kinetically trapped state is faster at elevated temperature, we can identify conditions where CYT-18 accelerates (catalyzes) bI5 RNA folding relative to assembly with CBP2. PMID:11399081

Webb, A E; Rose, M A; Westhof, E; Weeks, K M

2001-06-22

15

Design of a miniaturized solid state laser for automated assembly  

NASA Astrophysics Data System (ADS)

A miniaturized solid state laser for marking applications has been developed featuring novel assembly strategies to reduce size, cost and assembly effort. Design and setup have been laid out with future automation of the assembly in mind. Using a high precision robot the optical components composing the laser system are directly placed on a planar substrate providing accurate positioning and alignment within a few microns. No adjustable mounts for mirrors and lenses are necessary, greatly simplifying the setup. Consisting of either a ND:YAG or a Nd:YVO4 crystal pumped with a fiber coupled diode laser, a q-switch for pulse generation and a beam expander the entire assembly is confined in a 100ml space and delivers 4 W of continuous output power at 1.064 ?m with an efficiency greater than 40%. Pulse lengths of 10-20 ns and repetition rates of up to 150 kHz have been obtained with an acousto-optic modulator. In addition, a custom designed electro-optic modulator with integrated high voltage switch has been realized. A supply unit for the entire system, including scanner and water cooling, is integrated in a 19" industrial chassis and can be operated via a graphical user interface on a standard personal computer.

Funck, Max C.; Dolkemeyer, Jan; Morasch, Valentin; Loosen, Peter

2010-04-01

16

Internal states of model isotropic granular packings. I. Assembling process, geometry, and contact networks  

Microsoft Academic Search

This is the first paper of a series of three, in which we report on numerical simulation studies of geometric and mechanical properties of static assemblies of spherical beads under an isotropic pressure. The influence of various assembling processes on packing microstructures is investigated. It is accurately checked that frictionless systems assemble in the unique random close packing (RCP) state

Ivana Agnolin; Jean-Noël Roux

2007-01-01

17

76 FR 71510 - Meeting of the Assembly of the Administrative Conference of the United States  

Federal Register 2010, 2011, 2012, 2013

...CONFERENCE OF THE UNITED STATES Meeting of the Assembly of the Administrative Conference of the...notice is hereby given of a meeting of the Assembly of the Administrative Conference of the...meeting in plenary session constitutes the Assembly of the Conference (5 U.S.C....

2011-11-18

18

Discrete State Change Model of Manufacturing Quality to Aid Assembly Process Design  

NASA Astrophysics Data System (ADS)

This paper proposes a representation model of the quality state change in an assembly process that can be used in a computer-aided process design system. In order to formalize the state change of the manufacturing quality in the assembly process, the functions, operations, and quality changes in the assembly process are represented as a network model that can simulate discrete events. This paper also develops a design method for the assembly process. The design method calculates the space of quality state change and outputs a better assembly process (better operations and better sequences) that can be used to obtain the intended quality state of the final product. A computational redesigning algorithm of the assembly process that considers the manufacturing quality is developed. The proposed method can be used to design an improved manufacturing process by simulating the quality state change. A prototype system for planning an assembly process is implemented and applied to the design of an auto-breaker assembly process. The result of the design example indicates that the proposed assembly process planning method outputs a better manufacturing scenario based on the simulation of the quality state change.

Koga, Tsuyoshi; Aoyama, Kazuhiro

19

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

PubMed Central

In mature HIV-1 virions, a 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 report, 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,15N-labelled CA exhibit narrow lines, indicative of 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.

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

2010-01-01

20

Structure and Scm3-mediated assembly of budding yeast centromeric nucleosomes  

PubMed Central

Much controversy exists regarding the structural organization of the yeast centromeric nucleosome and the role of the nonhistone protein, Scm3, in its assembly and architecture. Here we show that the substitution of H3 with its centromeric variant Cse4 results in octameric nucleosomes that organize DNA in a left-handed superhelix. We demonstrate by single-molecule approaches, micrococcal nuclease digestion and small-angle X-ray scattering that Cse4-nucleosomes exhibit an open conformation with weakly bound terminal DNA segments. The Cse4-octamer does not preferentially form nucleosomes on its cognate centromeric DNA. We show that Scm3 functions as a Cse4-specific nucleosome assembly factor, and that the resulting octameric nucleosomes do not contain Scm3 as a stably bound component. Taken together, our data provide insights into the assembly and structural features of the budding yeast centromeric nucleosome.

Dechassa, Mekonnen Lemma; Wyns, Katharina; Li, Ming; Hall, Michael A.; Wang, Michelle D.; Luger, Karolin

2011-01-01

21

Efficient Calculation of Electron States in Self-Assembled Quantum Dots: Application to Auger Relaxation  

Microsoft Academic Search

An efficient method for calculation of self-assembled dot states within the effective mass approximation is described and its application to the calculation of Auger relaxation rates is detailed. The method is based on expansion of the dot states in a harmonic oscillator basis whose parameters are optimised to improve the convergence rate. This results in at least an order of

D. Chaney; M. Roy; P. Maksym

22

Ready to Assemble: Grading State Higher Education Accountability Systems  

ERIC Educational Resources Information Center

|States need strong higher education systems, now more than ever. In the tumultuous, highly competitive 21st century economy, citizens and workers need knowledge, skills, and credentials in order to prosper. Yet many colleges and universities are falling short. To give all students the best possible postsecondary education, states must create…

Aldeman, Chad; Carey, Kevin

2009-01-01

23

State of Nevada Telecommunications Study. Assembly Concurrent Resolution 68.  

ERIC Educational Resources Information Center

|This document offers the results of a study of Nevada's telecommunications requirements, based on a comprehensive survey of existing networks associated with state and local governments, school districts, and the university system. It reports that Nevada can accrue benefits from telecommunications in the areas of education, economic development,…

Nevada State Dept. of General Services, Carson City.

24

Excited state chemistry of capsular assemblies in aqueous solution and on silica surfaces.  

PubMed

Synthesis and encapsulation properties of two new water-soluble resorcinol-capped organic cavitands (tetra acid and octa acid; RTA and ROA) are reported in this Letter. Organic guest molecules template the formation of capsular assembly of the above cavitands in water. Depending upon the guest, either 1:2 (guest to host) or 2:2 capsular assemblies were formed. The excited state properties of guests such as anthracene, camphorthione, and 4,4'-dimethyl benzil were distinctly different within a capsular assembly from those when they were free in a solution. Importantly, the host-guest complexes of the above two hosts (RTA and ROA) as well as octa acid (OA) could be transferred to a silica surface. The excited state behavior of host-guest assemblies on silica surface resembled that in solution. The high cage effect in the decarbonylation products and high yield of rearrangement product obtained upon photolysis of 1-phenyl-3-tolyl-2-propanone included within RTA, ROA, and OA both in solution and on silica surface supported the conclusion that capsular assemblies of these hosts are stable on silica surface. PMID:22106849

Ramasamy, Elamparuthi; Jayaraj, Nithyanandhan; Porel, Mintu; Ramamurthy, Vaidhyanathan

2011-11-30

25

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

SciTech Connect

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.

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

1995-04-01

26

CDK-dependent phosphorylation and nuclear exclusion coordinately control kinetochore assembly state  

PubMed Central

Accurate chromosome segregation requires assembly of the multiprotein kinetochore complex. Prior work has identified more than 100 different kinetochore components in human cells. However, little is known about the regulatory processes that specify their assembly upon mitotic entry and disassembly at mitotic exit. In this paper, we used a live-cell imaging–based assay to quantify kinetochore disassembly kinetics and systematically analyze the role of potential regulatory mechanisms in controlling kinetochore assembly state. We find that kinetochore assembly and disassembly was driven primarily by mitotic phosphorylation downstream of cyclin-dependent kinase (CDK). In addition, we demonstrate that nuclear exclusion of the Ndc80 complex helped restrict kinetochore formation to mitosis. Combining constitutive CDK-dependent phosphorylation of CENP-T and forced nuclear localization of the Ndc80 complex partially prevented kinetochore disassembly at mitotic exit and led to chromosome segregation defects in subsequent divisions. In total, we find that the coordinated temporal regulation of outer kinetochore assembly is essential for accurate cell division.

Gascoigne, Karen E.

2013-01-01

27

Conserved features of intermediates in amyloid assembly determine their benign or toxic states  

PubMed Central

Some amyloid-forming polypeptides are associated with devastating human diseases and others provide important biological functions. For both, oligomeric intermediates appear during amyloid assembly. Currently we have few tools for characterizing these conformationally labile intermediates and discerning what governs their benign versus toxic states. Here, we examine intermediates in the assembly of a normal, functional amyloid, the prion-determining region of yeast Sup35 (NM). During assembly, NM formed a variety of oligomers with different sizes and conformation-specific antibody reactivities. Earlier oligomers were less compact and reacted with the conformational antibody A11. More mature oligomers were more compact and reacted with conformational antibody OC. We found we could arrest NM in either of these two distinct oligomeric states with small molecules or crosslinking. The A11-reactive oligomers were more hydrophobic (as measured by Nile Red binding) and were highly toxic to neuronal cells, while OC-reactive oligomers were less hydrophobic and were not toxic. The A11 and OC antibodies were originally raised against oligomers of A?, an amyloidogenic peptide implicated in Alzheimer’s disease (AD) that is completely unrelated to NM in sequence. Thus, this natural yeast prion samples two conformational states similar to those sampled by A?, and when assembly stalls at one of these two states, but not the other, it becomes extremely toxic. Our results have implications for selective pressures operating on the evolution of amyloid folds across a billion years of evolution. Understanding the features that govern such conformational transitions will shed light on human disease and evolution alike.

Krishnan, Rajaraman; Goodman, Jessica L.; Mukhopadhyay, Samrat; Pacheco, Chris D.; Lemke, Edward A.; Deniz, Ashok A.; Lindquist, Susan

2012-01-01

28

An amyloid organelle, solid-state NMR evidence for cross-? assembly of gas vesicles.  

PubMed

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 constitute the ribs of the buoyancy organelles of Anabaena flos-aquae. The walls of these gas-filled vesicles are known to comprise a single protein, GvpA, arranged in a low pitch helix. However, the tertiary and quaternary structures have been elusive. Using solid-state NMR correlation spectroscopy we find detailed evidence for an extended cross-? structure. This amyloid assembly helps to account for the strength and amphiphilic properties of the vesicle wall. Buoyancy organelles thus dramatically extend the scope of known functional amyloids. PMID:22147705

Bayro, Marvin J; Daviso, Eugenio; Belenky, Marina; Griffin, Robert G; Herzfeld, Judith

2011-12-06

29

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

SciTech Connect

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.

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

2010-01-01

30

Function and redox state of mitochondrial localized cysteine-rich proteins important in the assembly of cytochrome c oxidase  

PubMed Central

Summary The cytochrome c oxidase (CcO) complex of the mitochondrial respiratory chain exists within the mitochondrial inner membrane (IM). The biogenesis of the complex is a multi-faceted process requiring multiple assembly factors that function on both faces of the IM. Formation of the two copper centers of CcO occurs within the intermembrane space (IMS) and is dependent on assembly factors with critical cysteinyl thiolates. Two classes of assembly factors exist, one group being soluble IMS proteins and the second class being proteins tethered to the IM. A common motif in the soluble assembly factors is a duplicated Cx9C sequence motif. Since mitochondrial respiration is a major source of reactive oxygen species, control of the redox state of mitochondrial proteins is an important process. This review documents the role of these cysteinyl CcO assembly factors within the IMS and the necessity of redox control in their function.

Khalimonchuk, Oleh; Winge, Dennis R.

2008-01-01

31

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

Microsoft Academic Search

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,

Armin Scholl; Christian Becker

2006-01-01

32

Multimeric Assembly and Biochemical Characterization of the Trax-translin Endonuclease complex  

SciTech Connect

Trax-translin heteromers, also known as C3PO, have been proposed to activate the RNA-induced silencing complex (RISC) by facilitating endonucleolytic cleavage of the siRNA passenger strand. We report on the crystal structure of hexameric Drosophila C3PO formed by truncated translin and Trax, along with electron microscopic and mass spectrometric studies on octameric C3PO formed by full-length translin and Trax. Our studies establish that Trax adopts the translin fold, possesses catalytic centers essential for C3PO's endoRNase activity and interacts extensively with translin to form an octameric assembly. The catalytic pockets of Trax subunits are located within the interior chamber of the octameric scaffold. Truncated C3PO, like full-length C3PO, shows endoRNase activity that leaves 3'-hydroxyl-cleaved ends. We have measured the catalytic activity of C3PO and shown it to cleave almost stoichiometric amounts of substrate per second.

Y Tian; D Simanshu; M Ascano; R Diaz-Avalos; A Park; S Juranek; W Rice; Q Yin; C Robinson; et al.

2011-12-31

33

Supramolecular cobaloxime assemblies for H{sub 2} photocatalysis: an initial solution state structure-function analysis.  

SciTech Connect

In this report, we have investigated the correlations between structure and light-induced electron transfer of one known and three new axially coordinated cobaloxime-based supramolecular photocatalysts for the reduction of protons to hydrogen. Solution-phase X-ray scattering and ultrafast transient optical spectroscopy analyses were used in tandem to correlate the self-assembled photocatalysts structural integrity in solution with electron transfer and charge separation between the photosensitizer and catalyst fragments. Biphasic excited state decay kinetics were observed for several of the assemblies, suggesting that configurational dispersion plays a role in limiting photoinduced electron transfer. Notably, an assembly featuring a 'push-pull' donor-photosensitizer-acceptor triad motif exhibits considerable ultrafast excited state quenching and, of the assemblies examined, presents the strongest opportunity for efficient solar energy conversion. These results will assist in the design and development of next-generation supramolecular photocatalyst architectures.

Mulfort, K. L.; Tiede, D. M. (Chemical Sciences and Engineering Division)

2010-01-01

34

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

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 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...

2013-04-01

35

Non-centrosymmetric tetrameric assemblies of tetramethylammonium halides with uranyl salophen complexes in the solid state.  

PubMed

Ditopic salophen-UO(2) receptors 1-4 and 7 co-crystallize with tetramethylammonium (TMA) chloride and fluoride salts producing good quality crystals amenable for X-ray diffraction characterization. The arrangement of the receptor and salt units in the crystal lattice is such that tetrameric ball-shaped assemblies are formed, where an inner cluster of four TMA cations are surrounded by an outer shell of four UO(2)-bound anions. These elaborate architectures, which occur in all cases, regardless of a certain degree of structural modification on the receptors, lead to lattices that belong to non-centrosymmetric (NCS) space groups. Interestingly, the tetragonal symmetry of the tetrameric ball-shaped assemblies is either retained (I4?) or lost (R3c and I4?3d) at the lattice level, without compromising the NCS nature of the crystal lattices. The principal X-ray investigation on TMAX (X = Cl/F) co-crystals, that is, 1-(TMA)Cl, 2-(TMA)Cl, 3-(TMA)Cl, 4-(TMA)Cl, 7-(TMA)Cl, and 7-(TMA)F, is accompanied by NMR and electrospray ionization (ESI) mass spectrometry studies to gather additional insight on the modality of formation of the solid state structures observed. The important role of cation-? interactions in the receptor-salt recognition process is renewed and strengthened by comparison with NMR titration data with a novel reference compound, the salophen-UO(2) complex 8. Given the importance of NCS and polar crystalline solids in the development of functional materials, this study shows that this property can be introduced into elaborate host-guest systems, as those which assemble in the architectures described here, thus expanding its field of applicability. PMID:21090769

Cametti, Massimo; Ilander, Laura; Valkonen, Arto; Nieger, Martin; Nissinen, Maija; Nauha, Elisa; Rissanen, Kari

2010-11-23

36

Structural and dynamical characterization of tubular HIV-1 capsid protein assemblies by solid state nuclear magnetic resonance and electron microscopy  

PubMed Central

The wild-type HIV-1 capsid protein (CA) self-assembles in vitro into tubular structures at high ionic strength. We report solid state nuclear magnetic resonance (NMR) and electron microscopy measurements on these tubular CA assemblies, which are believed to contain a triangular lattice of hexameric CA proteins that is similar or identical to the lattice of capsids in intact HIV-1. Mass-per-length values of CA assemblies determined by dark-field transmission electron microscopy indicate a variety of structures, ranging from single-wall tubes to multiwall tubes that approximate solid rods. Two-dimensional (2D) solid state 13C—13C and 15N—13C NMR spectra of uniformly 15N,13C-labeled CA assemblies are highly congested, as expected for a 25.6 kDa protein in which nearly the entire amino acid sequence is immobilized. Solid state NMR spectra of partially labeled CA assemblies, expressed in 1,3-13C2-glycerol medium, are better resolved, allowing the identification of individual signals with line widths below 1 ppm. Comparison of crosspeak patterns in the experimental 2D spectra with simulated patterns based on solution NMR chemical shifts of the individual N-terminal (NTD) and C-terminal (CTD) domains indicates that NTD and CTD retain their individual structures upon self-assembly of full-length CA into tubes. 2D 1H-13C NMR spectra of CA assemblies recorded under solution NMR conditions show relatively few signals, primarily from segments that link the ?-helices of NTD and CTD and from the N- and C-terminal ends. Taken together, the data support the idea that CA assemblies contain a highly ordered 2D protein lattice in which the NTD and CTD structures are retained and largely immobilized.

Chen, Bo; Tycko, Robert

2010-01-01

37

Steady-state theory of the interference of GTP hydrolysis in the mechanism of microtubule assembly.  

PubMed Central

A model is presented for the interference of GTP hydrolysis in the mechanism of microtubule assembly. This model is suggested by previous results showing that both GTP and GDP are present at microtubule ends because of GTP hydrolysis and that tubulin does not bind to a GDP-bound end. The analytical theory developed here is aimed at calculation of the steady-state subunit flux at one end of the polymer. The GTP/GDP features just mentioned result in a nonlinear plot of the flux versus tubulin concentration. Microtubules are predicted to exhibit a different kinetic behavior below and above the critical concentration, which can be considered as a transition between two regimes.

Hill, T L; Carlier, M F

1983-01-01

38

Self-assembled multi-component catenanes: structural insights into an adaptable class of molecular receptors and [2]-catenanes.  

PubMed

Under acidic conditions (50 equiv of TFA), combinations of hydrazide A-B monomers self-assemble into octameric [2]-catenanes with high selectivity for [1(3)2](2), where 1 is a D-Pro-X (X = Aib, Ac(4)c, Ac(6)c, L-4-Cl-PhGly)-derived monomer and 2 is an L-Pro'-L-arylGly (Pro' = Pro, trans-F-Pro, trans-HO-Pro, aryl = naphthyl, phenyl)-derived monomer. Five different combinations of monomers were studied by X-ray crystallography. In each case, the unique aryl glycine unit is located in the core of the structure where the aryl ring templates a CH-?-CH sandwich. Analysis of metrical parameters indicates that this core region is highly conserved, while the more peripheral zones are flexible. (1)H NMR spectroscopy indicate that the solid-state structures are largely retained in solution, though several non-C(2)-symmetric compounds have a net C(2)-symmetry that indicates accessible dynamic processes. Catenane dynamic processes were additionally probed through H/D exchange, with the core being inflexible relative to the peripheral structure. Mass spectrometry was utilized to identify the constitutional isomerism in the minor asymmetric [1(5)2(3)] catenanes. PMID:22686480

Chung, Mee-Kyung; White, Peter S; Lee, Stephen J; Waters, Marcey L; Gagné, Michel R

2012-07-02

39

Preparation and solid state characterisation of chlorothiazide sodium intermolecular self-assembly suprastructure.  

PubMed

Chlorothiazide (CTZ), unlike other thiazide diuretics, can form salts. An injectable formulation containing the sodium salt is available; however neither the physicochemical characteristics of the salt nor its solid state form have been previously reported. This work reports on the crystal structure of chlorothiazide sodium. The structure was investigated by single crystal X-ray and nuclear magnetic spectroscopy (NMR) analyses and compared to chlorothiazide, while the solid state characteristics were assessed by thermal analysis, powder X-ray diffraction, infrared spectroscopy, dynamic moisture sorption and solubility analysis. The crystal structure of chlorothiazide sodium was determined to be triclinic; the crystal space group type was P-1. Chlorothiazide sodium presented a self-assembly polymeric-type suprastucture, where the unit cell comprised two chlorothiazide molecules bonded together with sodium cations through the water bridges. The coordinate centre comprised the following: (CTZ)(3)·(H(2)O)·Na(H(2)O)(2)Na·(H(2)O)·(CTZ)(3). The crystalline material was determined to be a monosodium dihydrate, stable in the range of 10-90% relative humidity (RH) at 25°C. Additional processing of the salt resulted in a crystalline anhydrous form which was stable in the range 0-20% RH at 25°C. The aqueous solubility of the chlorothiazide sodium dihydrate at 37°C was found to be approximately 400-fold higher than that of chlorothiazide, which may present biopharmaceutical advantages for the salt compared to the non-salt form. PMID:20816757

Paluch, Krzysztof J; Tajber, Lidia; McCabe, Thomas; O'Brien, John E; Corrigan, Owen I; Healy, Anne Marie

2010-09-09

40

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

PubMed

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

Roy, Rana; Usha, Veeraraghavan; Kermani, Ali; Scott, David J; Hyde, Eva I; Besra, Gurdyal S; Alderwick, Luke J; Fütterer, Klaus

2013-08-13

41

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

PubMed Central

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.

2013-01-01

42

Four-component assembly in the crystalline state driven by amidinium-carboxylate salt bridge formation from an aqueous solution.  

PubMed

A series of diamidine dihydrochlorides was prepared utilizing a spacer unit to control the distance between the two amidinium groups. The introduction of two amidinium groups to the 1,8-position of each spacer unit (i.e., 9,10-dihydroanthracene, anthracene, biphenylene) can control the direction of formation of a self-assembled structure. The fine-tuning of the distances between the two amidinium groups in the spacer units can help control the stabilizing interactions of two carboxylic acid units (intermolecular attraction) after the four-component assembly (see ). Based on this concept, we succeeded in the formation of a four-component box-like assembled structure using amidinium-carboxylate salt bridge formation in the crystalline state from aqueous solutions. PMID:23625021

Kusukawa, Takahiro; Matsumoto, Kazuya; Nakamura, Hajime; Iizuka, Wataru; Toyama, Keisuke; Takeshita, Shota

2013-06-14

43

Structural Analysis of Nanoscale Self-Assembled Discoidal Lipid Bilayers by Solid-State NMR Spectroscopy  

PubMed Central

Nanodiscs are an example of discoidal nanoscale self-assembled lipid/protein particles similar to nascent high-density lipoproteins, which reduce the risk of coronary artery disease. The major protein component of high-density lipoproteins is human apolipoprotein A-I, and the corresponding protein component of Nanodiscs is membrane scaffold protein 1 (MSP1), a 200-residue lipid-binding domain of human apolipoprotein A-I. Here we present magic-angle spinning (MAS) solid-state NMR studies of uniformly 13C,15N-labeled MSP1 in polyethylene glycol precipitated Nanodiscs. Two-dimensional MAS 13C-13C correlation spectra show excellent microscopic order of MSP1 in precipitated Nanodiscs. Secondary isotropic chemical shifts throughout the protein are consistent with a predominantly helical structure. Moreover, the backbone conformations of prolines derived from their 13C chemical shifts are consistent with the molecular belt model but not the picket fence model of lipid-bound MSP1. Overall comparison of experimental spectra and 13C chemical shifts predicted from several structural models also favors the belt model. Our study thus supports the belt model of Nanodisc structure and demonstrates the utility of MAS NMR to study the structure of high molecular weight lipid-protein complexes.

Li, Ying; Kijac, Aleksandra Z.; Sligar, Stephen G.; Rienstra, Chad M.

2006-01-01

44

Assembly and Comparison of Different Equations of State for Multiphase Carbon Dioxide in the Subsurface  

NASA Astrophysics Data System (ADS)

Sequestration of carbon dioxide in deep saline aquifers has been suggested as a possible means for reducing greenhouse gas concentrations in the atmosphere. For geological sequestration, an accurate equation-of-state (EOS) is critical for evaluating and estimating migration and ultimate diagenetic effects on permeability and porosity. We assembled, coded, and compared two different EOS algorithms. One is the modified Redlich-Kwong (MRK) EOS, which employs modification of the attractive term from van der Waals equation. The other is Span and Wagner's (SW) EOS, an empirical representation of the fundamental equation of Helmholtz energy. Using these fundamentally different EOS, the density, fugacity, and enthalpy of carbon dioxide in the gas and supercritical phases were simulated for several test case models. Results included some disparities between simulated and experimental data. Furthermore, for some simulations small errors were compounded and induced very significant impacts on ultimate carbon dioxide plume migration and associated subsurface chemical reactions. In particular, aqueous carbon dioxide solubility calculations by the two EOS algorithms reflected large differences, especially during longer time-scale simulations. In sum, results suggest that even small differences in thermodynamic properties of carbon dioxide, as calculated between the MRK and SW EOS, may produce magnified differences in ultimate projections of subsurface plume histories and associated chemical reaction processes.

Han, W.; McPherson, B. J.

2004-12-01

45

Regulation of the filament structure and assembly of Acanthamoeba myosin II by phosphorylation of serines in the heavy-chain nonhelical tailpiece  

PubMed Central

Acanthamoeba myosin II (AMII) has two heavy chains ending in a 27-residue nonhelical tailpiece and two pairs of light chains. In a companion article, we show that five, and only five, serine residues can be phosphorylated both in vitro and in vivo: Ser639 in surface loop 2 of the motor domain and serines 1489, 1494, 1499, and 1504 in the nonhelical tailpiece of the heavy chains. In that paper, we show that phosphorylation of Ser639 down-regulates the actin-activated MgATPase activity of AMII and that phosphorylation of the serines in the nonhelical tailpiece has no effect on enzymatic activity. Here we show that bipolar tetrameric, hexameric, and octameric minifilaments of AMII with the nonhelical tailpiece serines either phosphorylated or mutated to glutamate have longer bare zones and more tightly clustered heads than minifilaments of unphosphorylated AMII, irrespective of the phosphorylation state of Ser639. Although antiparallel dimers of phosphorylated and unphosphorylated myosins are indistinguishable, phosphorylation inhibits dimerization and filament assembly. Therefore, the different structures of tetramers, hexamers, and octamers of phosphorylated and unphosphorylated AMII must be caused by differences in the longitudinal stagger of phosphorylated and unphosphorylated bipolar dimers and tetramers. Thus, although the actin-activated MgATPase activity of AMII is regulated by phosphorylation of Ser639 in loop 2 of the motor domain, the structure of AMII minifilaments is regulated by phosphorylation of one or more of four serines in the nonhelical tailpiece of the heavy chain.

Liu, Xiong; Hong, Myoung-Soon; Shu, Shi; Yu, Shuhua; Korn, Edward D.

2013-01-01

46

Phosphonate self-assembled monolayers as organic linkers in solid-state quantum dot sensetized solar cells  

Microsoft Academic Search

We have employed X-ray photoelectron spectroscopy (XPS), ultraviolet-visible (UV-vis) spectroscopy, infrared (IR) spectroscopy, water contact angle (WCA) measurements, ellipsometry, and electrical measurements to study the effects of self-assembled monolayers (SAMs) with phosphonic acid headgroups on the bonding and performance of cadmium sulfide (CdS) solid-state quantum dot sensitized solar cells (QDSSCs). ~2 to ~6 nm size CdS quantum dots (QDs) were

Pendar Ardalan; Thomas P. Brennan; Jonathan R. Bakke; S. F. Bent

2010-01-01

47

Two equations of state assembled for basic analysis of multiphase CO 2 flow and in deep sedimentary basin conditions  

Microsoft Academic Search

The purpose of the study presented in this manuscript is to describe and make available two equation-of-state (EOS) algorithms assembled for multiphase flow and transport of carbon dioxide (CO2). The algorithms presented here calculate solubility, compressibility factor, density, viscosity, fugacity, and enthalpy of CO2 in gaseous and supercritical phases, and mixtures or solutions of CO2 in water, as functions of

Brian J. O. L. McPherson; Weon Shik Han; Barret S. Cole

2008-01-01

48

Three Distinct Equilibrium States via Self-Assembly: Simple Access to a Supramolecular Ion-Controlled NAND Logic Gate.  

PubMed

During the past several decades, considerable effort has focused on self-assembled systems. However, most work has been directed toward understanding the equilibrium between two major chemical entities, namely the dissociated components and the corresponding associated complex. While there are quite a few examples of 'multiresponsive' materials, control over 'multistate' materials has proved difficult to achieve. Here, we report the formation and the interplay of a self-assembled calix[4]pyrrole array that exhibits three limiting forms, namely a 1:1 self-assembled oligomer, a 2:1 capsule, and the corresponding monomers. Interconversion between these states may be controlled by using the tetraethylammonium cation (TEA(+)) and/or iodide anion (I(-)) as chemical inputs. The combination of self-assembly and ion-based control may be used to create systems that display NAND logic behavior. The system outputs have been confirmed by a variety of analytic methods, including UV-vis and 2D (1)H DOSY, NOESY NMR spectroscopy, scanning electron microscopy, and single crystal X-ray diffraction analyses. PMID:24011216

Kim, Dong Sub; Lynch, Vincent M; Park, Jung Su; Sessler, Jonathan L

2013-09-19

49

Empirical validation of viral quasispecies assembly algorithms: state-of-the-art and challenges  

PubMed Central

Next generation sequencing (NGS) is superseding Sanger technology for analysing intra-host viral populations, in terms of genome length and resolution. We introduce two new empirical validation data sets and test the available viral population assembly software. Two intra-host viral population ‘quasispecies’ samples (type-1 human immunodeficiency and hepatitis C virus) were Sanger-sequenced, and plasmid clone mixtures at controlled proportions were shotgun-sequenced using Roche's 454 sequencing platform. The performance of different assemblers was compared in terms of phylogenetic clustering and recombination with the Sanger clones. Phylogenetic clustering showed that all assemblers captured a proportion of the most divergent lineages, but none were able to provide a high precision/recall tradeoff. Estimated variant frequencies mildly correlated with the original. Given the limitations of currently available algorithms identified by our empirical validation, the development and exploitation of additional data sets is needed, in order to establish an efficient framework for viral population reconstruction using NGS.

Prosperi, Mattia C. F.; Yin, Li; Nolan, David J.; Lowe, Amanda D.; Goodenow, Maureen M.; Salemi, Marco

2013-01-01

50

Optimized assembly and steady-state length-scale control in dissipative systems of photo-switchable colloids  

NASA Astrophysics Data System (ADS)

Photo-switchable nanoparticles, such as those developed by Wei et al.,footnotetextY.H. Wei, S. B. Han, J. Kim, S. L. Soh and B. A. Grzybowski, J. Am. Chem. Soc., 2010, 132, 11018-11020. can be assembled into a broad range of structures using light exposure as a control parameter. Jha et al.footnotetextP.k. Jha, V. Kuzovkov, B.A. Grzybowski, and M. Olvera del la Cruz, Soft Matter, 2012, 8, 227-234 explored the evolution of these structures using kinetic Monte Carlo simulations. In this work, we build on these studies using Molecular Dynamics with a Langevin thermostat to, by judicious choice of exposure parameters that control the dissipative nature of the system, engineer and optimize the self-assembly pathways as well as control the length scales of the steady-state structures.

Osorio-Vivanco, Antonio; Olvera de La Cruz, Monica; Glotzer, Sharon

2013-03-01

51

Conserved and Cooperative Assembly of Membrane-Bound ?-Helical States of Islet Amyloid Polypeptide †  

Microsoft Academic Search

The conversion of soluble protein into ‚-sheet-rich amyloid fibers is the hallmark of a number of serious diseases. Precursors for many of these systems (e.g., A‚ from Alzheimer's disease) reside in close association with a biological membrane. Membrane bilayers are reported to accelerate the rate of amyloid assembly. Furthermore, membrane permeabilization by amyloidogenic peptides can lead to toxicity. Given the

Jefferson D. Knight; James A. Hebda; Andrew D. Miranker

2006-01-01

52

Supramolecular assembly of conjugated polymers: From molecular engineering to solid-state properties  

Microsoft Academic Search

?-Conjugated polymers are central ingredients in the development of organic electronics and it is well-known that the degree of order in thin films of those materials is a major factor governing the performances of the devices (field effect transistors, light-emitting diodes, photovoltaic cells). In this review, we present some approaches for the control of the molecular assembly of conjugated polymers

Ph. Leclère; M. Surin; P. Brocorens; M. Cavallini; F. Biscarini; R. Lazzaroni

2006-01-01

53

Seal assembly  

DOEpatents

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.

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

2001-01-01

54

Zinc chlorins for artificial light-harvesting self-assemble into antiparallel stacks forming a microcrystalline solid-state material  

PubMed Central

We introduce a concept to solve the structure of a microcrystalline material in the solid-state at natural abundance without access to distance constraints, using magic angle spinning (MAS) NMR spectroscopy in conjunction with X-ray powder diffraction and DFT calculations. The method is applied to a novel class of materials that form (semi)conductive 1D wires for supramolecular electronics and artificial light-harvesting. The zinc chlorins 3-devinyl-31-hydroxymethyl-132-demethoxycarbonylpheophorbide a (3?,5?-bis-dodecyloxy)benzyl ester zinc complex 1 and 3-devinyl-31-methoxymethyl-132-demethoxycarbonylpheophorbide a (3?,5?-bis-dodecyloxy)benzyl ester zinc complex 2, self-assemble into extended excitonically coupled chromophore stacks. 1H-13C heteronuclear dipolar correlation MAS NMR experiments provided the 1H resonance assignment of the chlorin rings that allowed accurate probing of ring currents related to the stacking of macrocycles. DFT ring-current shift calculations revealed that both chlorins self-assemble in antiparallel ?-stacks in planar layers in the solid-state. Concomitantly, X-ray powder diffraction measurements for chlorin 2 at 80 °C revealed a 3D lattice for the mesoscale packing that matches molecular mechanics optimized aggregate models. For chlorin 2 the stacks alternate with a periodicity of 0.68 nm and a 3D unit cell with an approximate volume of 6.28 nm3 containing 4 molecules, which is consistent with space group P21221.

Ganapathy, Swapna; Sengupta, Sanchita; Wawrzyniak, Piotr K.; Huber, Valerie; Buda, Francesco; Baumeister, Ute; Wurthner, Frank; de Groot, Huub J. M.

2009-01-01

55

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

PubMed Central

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.

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

2013-01-01

56

Hierarchical Superstructures from the Self-assembly of Giant Surfactants in Condensed State  

NASA Astrophysics Data System (ADS)

Giant surfactants are a class of tadpole-shaped hybrid nanomaterials with a functional nanoparticle as the head group and a polymer chain as the tail, such as perfluorochain-functionalized polyhedral oligomeric silsesquioxane end-capped poly(?-caprolactone) (FPOSS-PCL). The self-assembly of FPOSS-PCL with different composition in bulk were studied using DSC, SAXS, WAXD, and TEM. The compact arranagement of the perfluorochains on the POSS nanoparticles clearly distinguishes them from the polymer chain, leading to the formation of nanophase-separated supramolecular structures such as spheres, cylinders, and bilayered lamellaes. This physical picture is rather unusual and quite reminescent to that observed in the aggregates of small-molecule surfactants. The striking similarity indicates the importance in tuning the interactions to control the hierarchical structure formation in hybrid nanomaterials.

Zhang, Wen-Bin; Yu, Xinfei; Dong, Xuehui; Li, Yiwen; Yue, Kan; He, Jinlin; Cheng, Stephen

2011-03-01

57

Two equations of state assembled for basic analysis of multiphase CO 2 flow and in deep sedimentary basin conditions  

NASA Astrophysics Data System (ADS)

The purpose of the study presented in this manuscript is to describe and make available two equation-of-state (EOS) algorithms assembled for multiphase flow and transport of carbon dioxide (CO 2). The algorithms presented here calculate solubility, compressibility factor, density, viscosity, fugacity, and enthalpy of CO 2 in gaseous and supercritical phases, and mixtures or solutions of CO 2 in water, as functions of pressure and temperature. Several features distinguish the two algorithms, but the primary distinction concerns treatment of supercritical/gas-phase CO 2: one EOS we assembled is based on Redlich and Kwong's original algorithm developed in 1949, and the other is based on an algorithm developed by Span and Wagner in 1996. Both were modified for application to sedimentary basin studies of multiphase CO 2 flow processes, including carbon sequestration applications. We present a brief comparison of these two EOS algorithms. Source codes for both algorithms are provided, including "stand-alone" Matlab scripts for the interactive calculation of fluid properties at specified P- T conditions and FORTRAN subroutines for inclusion in existing FORTRAN multiphase fluid simulation packages. These routines are intended for fundamental analyses of CO 2 sequestration and the like; more advanced studies, such as brine processes and reactive transport, require more advanced EOS algorithms.

McPherson, Brian J. O. L.; Han, Weon Shik; Cole, Barret S.

2008-05-01

58

Independent saturation of three TrpRS subsites generates a partially assembled state similar to those observed in molecular simulations  

SciTech Connect

Two new crystal structures of Bacillus stearothermophilus tryptophanyl-tRNA synthetase (TrpRS) afford evidence that a closed interdomain hinge angle requires a covalent bond between AMP and an occupant of either pyrophosphate or tryptophan subsite. They also are within experimental error of a cluster of structures observed in a nonequilibrium molecular dynamics simulation showing partial active-site assembly. Further, the highest energy structure in a minimum action pathway computed by using elastic network models for Open and Pretransition state (PreTS) conformations for the fully liganded TrpRS monomer is intermediate between that simulated structure and a partially disassembled structure from a nonequilibrium molecular dynamics trajectory for the unliganded PreTS. These mutual consistencies provide unexpected validation of inferences drawn from molecular simulations.

Laowanapiban, Poramaet; Kapustina, Maryna; Vonrhein, Clemens; Delarue, Marc; Koehl, Patrice; Carter Jr., Charles W.; (Centre National de la Recherche Scientifique); (GPL); (UCD); (UNC)

2009-03-05

59

Zinc chlorins for artificial light-harvesting self-assemble into antiparallel stacks forming a microcrystalline solid-state material.  

PubMed

We introduce a concept to solve the structure of a microcrystalline material in the solid-state at natural abundance without access to distance constraints, using magic angle spinning (MAS) NMR spectroscopy in conjunction with X-ray powder diffraction and DFT calculations. The method is applied to a novel class of materials that form (semi)conductive 1D wires for supramolecular electronics and artificial light-harvesting. The zinc chlorins 3-devinyl-3(1)-hydroxymethyl-13(2)-demethoxycarbonylpheophorbide a (3',5'-bis-dodecyloxy)benzyl ester zinc complex 1 and 3-devinyl-3(1)-methoxymethyl-13(2)-demethoxycarbonylpheophorbide a (3',5'-bis-dodecyloxy)benzyl ester zinc complex 2, self-assemble into extended excitonically coupled chromophore stacks. (1)H-(13)C heteronuclear dipolar correlation MAS NMR experiments provided the (1)H resonance assignment of the chlorin rings that allowed accurate probing of ring currents related to the stacking of macrocycles. DFT ring-current shift calculations revealed that both chlorins self-assemble in antiparallel pi-stacks in planar layers in the solid-state. Concomitantly, X-ray powder diffraction measurements for chlorin 2 at 80 degrees C revealed a 3D lattice for the mesoscale packing that matches molecular mechanics optimized aggregate models. For chlorin 2 the stacks alternate with a periodicity of 0.68 nm and a 3D unit cell with an approximate volume of 6.28 nm(3) containing 4 molecules, which is consistent with space group P2(1)22(1). PMID:19587237

Ganapathy, Swapna; Sengupta, Sanchita; Wawrzyniak, Piotr K; Huber, Valerie; Buda, Francesco; Baumeister, Ute; Würthner, Frank; de Groot, Huub J M

2009-07-08

60

Subunit Conformations and Assembly States of a DNA Translocating Motor: The Terminase of Bacteriophage P22  

PubMed Central

Bacteriophage P22, a podovirus infecting strains of Salmonella typhimurium, packages a 42 kbp genome using a headful mechanism. DNA translocation is accomplished by the phage terminase, a powerful molecular motor consisting of large and small subunits. Although many of the structural proteins of the P22 virion have been well characterized, little is known about the terminase subunits and their molecular mechanism of DNA translocation. We report here structural and assembly properties of ectopically expressed and highly purified terminase large and small subunits. The large subunit (gp2), which contains the nuclease and ATPase activities of terminase, exists as a stable monomer with an ?/? fold. The small subunit (gp3), which recognizes DNA for packaging and may regulate gp2 activity, exhibits a highly ?-helical secondary structure and self-associates to form a stable oligomeric ring in solution. For wildtype gp3, the ring contains nine subunits, as demonstrated by hydrodynamic measurements, electron microscopy and native mass spectrometry. We have also characterized a gp3 mutant (Ala 112 ? Thr) that forms a ten subunit ring, despite a subunit fold indistinguishable from wildtype. Both the nonameric and decameric gp3 rings exhibit nonspecific DNA binding activity, and gp2 is able to bind strongly to the DNA/gp3 complex but not to DNA alone. We propose a scheme for the roles of P22 terminase large and small subunits in the recruitment and packaging of viral DNA and discuss the model in relation to proposals for terminase-driven DNA translocation in other phages.

Nemecek, Daniel; Gilcrease, Eddie B.; Kang, Sebyung; Prevelige, Peter E.; Casjens, Sherwood; Thomas, George J.

2007-01-01

61

Preparation and characterisation of novel chlorothiazide potassium solid-state salt forms: Intermolecular self assembly suprastructures.  

PubMed

Chlorothiazide (CTZ) is a poorly soluble diuretic agent. The aim of the present work was to produce and characterise a potassium salt form of chlorothiazide which has the potential advantages of improved aqueous solubility and potassium supplementation. A number of novel potassium salt forms of CTZ (CTZK) were prepared: CTZK monohydrate (form I), CTZK dihydrate (form II), anhydrous CTZK (form III), CTZK monohydrate hemiethanolate (form IV) and a desolvate of CTZK monohydrate hemiethanolate (form V). These salt forms were characterised by thermal analysis, PXRD, NMR, elemental analysis, FTIR, Karl Fisher titrimetry, ICP-MS and GC-MS. The ethanol-free CTZK forms were also characterised by dynamic vapour sorption analysis (DVS). CTZK form I was stable (in the DVS) over the range 0-60% RH. The dihydrate form of the salt was stable (in the DVS) over a broader range of relative humidities, 10-90% RH at 25°C. CTZK form II was less hygroscopic at high humidities (70-90% RH) than the previously reported CTZNa dihydrate. Single crystal X-ray analysis indicated that chlorothiazide potassium, crystallised from water or water/acetone mixture, formed a dihydrated polymeric-like intermolecular self-assembly (ISA) suprastructure. The ISA coordination was determined to be: (CTZ)(3)·K·(H(2)O)(2)(CTZ)(2)·(H(2)O)(2)·K·(CTZ)(3) (monoclinic, space group: C2/c, single crystal cell parameters: a=18.328(4)?, b=7.3662(16)?, c=19.993(5)?, ?=90°, ?=99.729(3)°, ?=90°). When CTZK was crystallised from ethanol, a monohydrate hemiethanolate ISA was formed, described as (CTZ)(3)·K·CTZ·(H(2)O)(2)·CTZ·K·(CTZ)(2) (triclinic, space group: P-1, single crystal cell parameters: a=7.078(3)?, b=9.842(5)?, c=21.994(11)?, ?=87.522(13)°, ?=84.064(14)°, ?=78.822(12)°). The aqueous solubility of CTZK dihydrate, was determined to be 78.71±1.82mg/ml, approximately 400-fold higher than chlorothiazide, indicating a biopharmaceutical advantage associated with the potassium salt form. PMID:21115114

Paluch, Krzysztof J; Tajber, Lidia; McCabe, Thomas; O'Brien, John E; Corrigan, Owen I; Healy, Anne Marie

2010-11-27

62

Ground state splitting of vertically stacked indium arsenide self-assembled quantum dots  

NASA Astrophysics Data System (ADS)

An attractive feature of vertically stacked InAs/AlGaAs quantum dots (QDs), which were buried in AlGaAs high potential barrier and spacer epilayer and grown by molecular-beam epitaxy with size-controlled growth, exhibits an unknown macroscopic quantum phenomenon (i.e., phase-change splitting of the ground state). In the vertically aligned QDs, due to many-body effect and quantum-mechanical renormalization, the electron ground state splits into a series of peaks of which the intensity gradually, systematically decreases to redshift direction with a wavelength constant. By the way, energy levels of electrons and holes might really be "seen" by deep level transient spectroscopy to which the photoluminescence experiment is in an excellent agreement.

Li, Shuwei; Koike, Kazuto

2002-11-01

63

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

Microsoft Academic Search

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

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

1993-01-01

64

Evaluation of a symmetry-based strategy for assembling protein complexes†  

PubMed Central

We evaluate a strategy for assembling proteins into large cage-like structures, based on the symmetry associated with the native protein’s quaternary structure. Using a trimeric protein, KDPG aldolase, as a building block, two fusion proteins were designed that could assemble together upon mixing. The fusion proteins, designated A-(+) and A-(?), comprise the aldolase domain, a short, flexible spacer sequence, and a sequence designed to form a heterodimeric antiparallel coiled-coil between A-(+) and A-(?). The flexible spacer is included to minimize constraints on the ability of the fusion proteins to assemble into larger structures. On incubating together, A-(+) and A-(?) assembled into a mixture of complexes that were analyzed by size exclusion chromatography coupled to multi-angle laser light scattering, analytical ultracentrifugation, transmission electron microscopy and atomic force microscopy. Our analysis indicates that, despite the inherent flexibility of the assembly strategy, the proteins assemble into a limited number of globular structures. Dimeric and tetrameric complexes of A-(+) and A-(?) predominate, with some evidence for the formation of larger assemblies; e.g. octameric A-(+): A-(?) complexes.

Patterson, Dustin P.; Desai, Ankur M.; Holl, Mark M. Banaszak; Marsh, E. Neil G.

2012-01-01

65

Resonant X-ray emission spectroscopy reveals d-d ligand-field states involved in the self-assembly of a square-planar platinum complex.  

PubMed

Resonant X-ray Emission Spectroscopy (RXES) is used to characterize the ligand field states of the prototypic self-assembled square-planar complex, [Pt(tpy)Cl]Cl (tpy=2,2':6',2''-terpyridine), and determine the effect of weak metal-metal and ?-? interactions on their energy. PMID:23007111

Garino, Claudio; Gallo, Erik; Smolentsev, Nikolay; Glatzel, Pieter; Gobetto, Roberto; Lamberti, Carlo; Sadler, Peter J; Salassa, Luca

2012-09-24

66

Structure determination of a bio-inspired self-assembled light-harvesting antenna by solid-state NMR and molecular modeling.  

PubMed

The molecular stacking of an artificial light-harvesting antenna self-assembled from 3(1)-aminofunctionalized zinc-chlorins was determined by solid-state NMR in combination with quantum-chemical and molecular-mechanics modeling. A library of trial molecular stacking arrangements was generated based on available structural data for natural and semisynthetic homologues of the Zn-chlorins. NMR assignments obtained for the monomer in solution were validated for self-assembled aggregates and refined with (1)H-(13)C heteronuclear correlation spectroscopy data collected from samples with (13)C at natural abundance. Solid-state ring-current shifts for the (1)H provided spatial constraints to determine the molecular overlap. This procedure allows for a discrimination between different self-assembled structures and a classification of the stacking mode in terms of electric dipole alignment and ?-? interactions, parameters that determine the functional properties of light-harvesting assemblies and conducting nanowires. The combination with quantum-mechanical modeling then allowed building a low-resolution packing model in silico from molecular stacks. The method allows for moderate disorder and residual polymorphism at the stack or molecular level and is generally applicable to determine molecular packing structures of aromatic molecules with structural asymmetry, such as is commonly provided by functionalized side chains that serve to tune the self-assembly process. PMID:23566216

Pandit, Anjali; Ocakoglu, Kasim; Buda, Francesco; van Marle, Thomas; Holzwarth, Alfred R; de Groot, Huub J M

2013-05-03

67

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

NASA Astrophysics Data System (ADS)

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.

Catropa, Dan; Azad, Farsh

2013-09-01

68

Hole states in Ge/Si quantum-dot molecules produced by strain-driven self-assembly  

NASA Astrophysics Data System (ADS)

Space-charge spectroscopy was employed to study hole emission from the confined states in vertically self-aligned double Ge quantum dots separated by a Si barrier. From the temperature- and frequency-dependent measurements, the hole binding energy was determined as a function of the separation between the dots, tSi. Increasing of the ground state hole energy due to formation of a bonding molecular orbital was found to be as large as ~50 meV at tSi=1.5 nm. For a dot layer separation exceeding 3 nm, the hole binding energy in double-dot molecule becomes smaller than the ionization energy of the single Ge dot, contrasting with a simplified quantum-mechanical molecular model. To analyze the experiment the electronic structure of two vertically coupled pyramidal Ge quantum dots embedded in Si was investigated by a nearest neighbor tight-binding single-particle Hamiltonian with the sp3 basis. The elastic strain due to the lattice mismatch between Ge and Si was included into the problem. The three-dimensional spatial strain distribution was found in terms of atomic positions using a valence-force-field theory with a Keating interatomic potential. It was demonstrated that formation of single-particle hole states in self-organized molecules is governed by the interplay among two effects. The first is the quantum-mechanical coupling between the individual states of two dots constituting the molecule. The second one originates from asymmetry of the strain field distribution within the top and bottom dots due to the lack of inversion symmetry with respect to the medium plane between the dots. Analysis of the biaxial strain distribution showed that anomalous decreasing of the hole binding energy below the value of the single dot with increasing interdot separation is caused by the partial strain relaxation upon dot stacking accompanied by the strain-induced reduction of the hole confinement potential. We found that the molecule-type hole state delocalized fairly over the two dots is formed only at tSi<3.3 nm and at tSi>3.8 nm. For the intermediate distances (3.3 nm<=tSi<=3.8 nm), the hole becomes confined mostly inside the bottom, most strained Ge dot. The overall agreement between theory and experiment turns out to be quite good, indicating the crucial role played by strain fields in electronic coupling of self-assembled quantum-dot molecules.

Yakimov, A. I.; Mikhalyov, G. Yu.; Dvurechenskii, A. V.; Nikiforov, A. I.

2007-11-01

69

Micelle Assemblies.  

National Technical Information Service (NTIS)

The invention encompasses micelle assemblies, compositions having micelle assemblies, and methods for preparing micelle assemblies and compositions thereof. Also, the invention encompasses compounds of the formula: A-X-Y-Z-R(sub 1) wherein A is a carboxy ...

K. E. Uhrich L. Tian

2004-01-01

70

Assembly technology  

NASA Astrophysics Data System (ADS)

Laboratory procedure governing the mounting of electronic components is specified with relation to space projects. The domain of application covers: assembly materials and accessories (fixtures, holders, wrapping, glues, varnishes, potting compounds) assembly elements (printed circuits, wire, cables, connectors) assembly techniques (soldering, crimping, wiring, stripping) and microelectronic techniques (thin film hybrid circuits, thick film). The choice of materials, elements, and technology is explained. Quality control during assembly is discussed. Assembly procedure flow charts concerning printed circuits are offered as examples. Space qualification of assemblies is illustrated and failure modes are studied.

Linder, F.

71

Correlations in Party Performance in State Legislative Assembly and Subsequent National Parliamentary Elections in India, 1980–2009  

Microsoft Academic Search

Using a panel data estimation technique, this article examines correlations in party performance in India for political parties that contested legislative assembly and federal parliamentary elections held within the following eighteen months during the period between 1980 and 2009. The results are analysed according to a range of variables, including type of party and voter turnout. The study's finding that,

Matthew J. Webb; Albert Wijeweera

2012-01-01

72

Assembly technology  

Microsoft Academic Search

Laboratory procedure governing the mounting of electronic components is specified with relation to space projects. The domain of application covers: assembly materials and accessories (fixtures, holders, wrapping, glues, varnishes, potting compounds) assembly elements (printed circuits, wire, cables, connectors) assembly techniques (soldering, crimping, wiring, stripping) and microelectronic techniques (thin film hybrid circuits, thick film). The choice of materials, elements, and technology

F. Linder

1981-01-01

73

Bacteriophage Assembly  

PubMed Central

Bacteriophages have been a model system to study assembly processes for over half a century. Formation of infectious phage particles involves specific protein-protein and protein-nucleic acid interactions, as well as large conformational changes of assembly precursors. The sequence and molecular mechanisms of phage assembly have been elucidated by a variety of methods. Differences and similarities of assembly processes in several different groups of bacteriophages are discussed in this review. The general principles of phage assembly are applicable to many macromolecular complexes.

Aksyuk, Anastasia A.; Rossmann, Michael G.

2011-01-01

74

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

NASA Astrophysics Data System (ADS)

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.

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

1993-04-01

75

NMR relaxation studies of an RNA-binding segment of the Rous sarcoma virus Gag polyprotein in free and bound states - a model for autoinhibition of assembly  

PubMed Central

Assembly of retrovirus particles is promoted by interaction of the Gag polyprotein with RNA. Nonspecific RNA association with the nucleocapsid domain (NC) of Gag induces the dimerization of Gag through protein-protein contacts in the capsid domain (CA), followed by higher-order assembly to form the immature virus particle. NMR relaxation studies were conducted to investigate the initial steps of Rous sarcoma virus (RSV) assembly by examining the association with nucleic acid of a fragment of Gag comprising the C-terminal domain of CA (CTD) postulated to mediate Gag dimerization, the spacer region between CA and NC (SP), and NC. This fragment, CTD-SP-NC (residues 394 to 577), spans the critical SP region and allows assessment of this key Gag-nucleic acid interaction in the context of the Gag polyprotein rather than the isolated domains. Mainchain amide relaxation of CTD-SP-NC was measured in the absence and presence of (GT)4, an 8-mer DNA oligonucleotide that binds tightly to the polyprotein but is too short to promote Gag dimerization. The results show that the CTD and NC domains tumble independently. In contrast, the two zinc finger domains within NC are rotationally coupled in both the unbound and bound states, even though only the first zinc finger appears to make direct contact with (GT)4. In addition, the NMR data indicate that SP and flanking residues undergo a conformational exchange process that is slowed in the presence of (GT)4. This region around SP where relaxation is strongly affected by (GT)4 binding is nearly identical to the assembly domain defined previously by mutagenesis studies. Other changes in relaxation induced by (GT)4 implicate conformational perturbations of helices 1 and 4 in CTD. Based on the combined data, we propose a model for the promotion of Gag dimerization by RNA association in which NC-RNA binding disrupts an assembly-inhibitory, intramolecular interaction involving SP and CTD. Disruption of this intramolecular interaction is proposed to enhance the accessibility of the Gag dimer contact surface and release the assembly domain to promote intermolecular oligomerization.

Taylor, Gwen M.; Ma, Lixin; Vogt, Volker M.; Post, Carol Beth

2010-01-01

76

Excited electron dynamics at ferrocene-terminated self-assembled monolayers on Au(1 1 1): Lengthened lifetime of image potential state  

NASA Astrophysics Data System (ADS)

Ultraviolet photoemission spectroscopy (UPS) and two-photon photoemission (2PPE) spectroscopy have been employed to investigate the electronic states and the excited electron dynamics of ferrocene (Fc)-terminated self-assembled monolayers (SAMs) on Au(1 1 1). For the 11-ferrocenyl-1-undecanethiol (FcC11-) SAM, an image potential state (IPS) located at EF +3.8 eV was observed by time-resolved 2PPE. Its lifetime, 90 fs, was found to be much shorter than that of decanethiol (C10-) SAM, 11 ps. By forming the C10-SAM beforehand, the IPS lifetime for FcC11-&C10-SAM was lengthened to ˜9 ps; this can enable improvement in molecular ordering and substantial formation of C10 domains.

Hirata, Naoyuki; Shibuta, Masahiro; Eguchi, Toyoaki; Nakajima, Atsushi

2013-03-01

77

Composite state control and magnetic properties of Co and Si cluster assemblies prepared with double-glow-discharge sources  

SciTech Connect

Using a double-glow-discharge-cluster-source system, in which one glow discharge was a dc mode and the other an rf discharge mode, Co and Si clusters were independently produced and simultaneously deposited on a substrate. When a separation plate was inserted between two glow-discharge chambers, a mixture of Co and Si clusters was obtained: small Co clusters were distributed at random, while the Si clusters were aggregated to form large secondary particles. Without inserting the separation plate, on the other hand, core-shell clusters were obtained: a Co core was surrounded by small Si crystallites. The magnetization measurement indicated that the magnetic coercive force of Co/Si core-shell cluster assemblies was much smaller than that of Co cluster assemblies in which Co clusters were covered with antiferromagnetic CoO shells, indicating that the Si shell prevented Co cluster surfaces from their oxidation. Therefore, the present double-cluster-source system is useful in fabricating various sorts of cluster composites, which cannot be prepared by conventional coevaporation or precipitation methods.

Katoh, Ryoji; Hihara, Takehiko; Peng, D.-L.; Sumiyama, Kenji [Department of Materials Science and Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan)

2006-08-01

78

Spin coherence generation in negatively charged self-assembled (In,Ga)As quantum dots by pumping excited trion states  

NASA Astrophysics Data System (ADS)

Spin coherence generation in an ensemble of negatively charged (In,Ga)As/GaAs quantum dots was investigated by picosecond time-resolved pump-probe spectroscopy measuring ellipticity. Robust coherence of the ground-state electron spins is generated by pumping excited charged exciton (trion) states. The phase of the coherent state, as evidenced by the spin ensemble precession about an external magnetic field, varies relative to spin coherence generation resonant with the ground state. The phase variation depends on the pump photon energy. It is determined by (a) pumping dominantly either singlet or triplet excited states, leading to a phase inversion, and (b) the subsequent carrier relaxation into the ground states. From the dependence of the precession phase and the measured g factors, information about the quantum dot shell splitting and the exchange energy splitting between triplet and singlet states can be extracted in the ensemble.

Henriques, A. B.; Schwan, A.; Varwig, S.; Maia, A. D. B.; Quivy, A. A.; Yakovlev, D. R.; Bayer, M.

2012-09-01

79

Possible conformation of amphotericin B dimer in membrane-bound assembly as deduced from solid-state NMR.  

PubMed

Aiming for structural analysis of amphotericin B (AmB) ion-channel assemblies in membrane, a covalent dimer was synthesized between (13)C-labled AmB methyl ester and (19)F-labled AmB. The dimer showed slightly weaker but significant biological activities against fungi and red blood cells compared with those of monomeric AmB. Then the dimer was subjected to (13)C{(19)F}REDOR (Rotational-Echo Double Resonance) experiments in hydrated lipid bilayers. The obtained REDOR dephasing effects were explained by two components; a short (13)C/(19)F distance (6.9Å) accounting for 23% of the REDOR dephasing, and a longer one (14Å) comprising the rest of the dephasing. The shorter distance is likely to reflect the formation of barrel-stave ion channel. PMID:22959766

Umegawa, Yuichi; Adachi, Takeshi; Matsumori, Nobuaki; Murata, Michio

2012-08-19

80

Assembly Line  

NSDL National Science Digital Library

In this activity, learners work individually to assemble a product and then work in teams to design, construct, test, and redesign an assembly line process whose product must meet specific quality control criteria. Learners reflect and compare the two approaches. Note: Page 14 is not in the correct position. It should actually be between pages 2 and 3.

Ieee

2013-07-08

81

Retrieval Assembly.  

National Technical Information Service (NTIS)

The patent application relates to a retrieval assembly, in combination with an airborne vehicle capable of hovering (e.g., a helicopter), for use in retrieving a downed drone airborne vehicle. The assembly includes a hook subassembly, a pole subassembly w...

D. B. Day

1973-01-01

82

Geometric reasoning about assembly tools  

SciTech Connect

Planning for assembly requires reasoning about various tools used by humans, robots, or other automation to manipulate, attach, and test parts and subassemblies. This paper presents a general framework to represent and reason about geometric accessibility issues for a wide variety of such 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 then reduced to an instance of the FINDPLACE problem. In addition, the author presents more efficient methods to integrate the framework into assembly planning. For tools that are applied either before or after their target parts are mated, one method pre-processes a single tool application for all possible states of assembly of a product in polynomial time, reducing all later state-tool queries to evaluations of a simple expression. For tools applied after their target parts are mated, a complementary method guarantees polynomial-time assembly planning. The author presents a wide variety of tools that can be described adequately using the approach, and surveys tool catalogs to determine coverage of standard tools. Finally, the author describes an implementation of the approach in an assembly planning system and experiments with a library of over one hundred manual and robotic tools and several complex assemblies.

Wilson, R.H.

1997-01-01

83

Asymmetrically substituted benzene-1,3,5-tricarboxamides: self-assembly and odd-even effects in the solid state and in dilute solution.  

PubMed

Molecular organization: Chiral benzene tricarboxamides with methyl substituents at defined positions self-assemble into supramolecular polymers of preferred helicity by three-fold alpha-helical-type hydrogen bonding. The odd-even effect is operative and all derivatives are liquid crystalline showing a Col(ho) phase (see figure).Asymmetric benzene-1,3,5-tricarboxamides (aBTAs) comprising two n-octyl and one chiral methyl-alkyl side chain were synthesised and characterised. The influence of the position and the configuration of the chiral methyl group (methyl at the alpha, beta or gamma position) in the aliphatic side chains on the liquid-crystalline properties and the aggregation behaviour of the aBTAs was systematically studied and compared to symmetrical benzene-1,3,5-tricarboxamides (sBTAs). Solid-state characterisation (polarised optical microscopy, IR spectroscopy, X-ray diffraction and differential scanning calorimetry) revealed that all aBTAs show threefold, alpha-helical-type intermolecular hydrogen bonding between neighbouring molecules and exhibit a columnar hexagonal organisation from room temperature to well above 200 degrees C. Moving the chiral methyl group closer to the amide group stabilises the liquid-crystalline state, as evidenced by a higher clearing temperature and corresponding enthalpy. The self-assembly of dilute solutions of the aBTAs in methylcyclohexane ( approximately 10(-5) mol L(-1)) was investigated with circular dichroism (CD) spectroscopy. The sign of the Cotton effect demonstrated a pronounced odd-even effect, whereas the value of the molar ellipticity, Deltaepsilon, in the aBTAs was independent of the position of the methyl group. Subsequent temperature-dependent CD measurements showed that the aggregation of all aBTAs can quantitatively be described by the nucleation-growth model and that the stability of the aggregates increases when the chiral methyl group is closer to the amide moiety. The results presented herein illustrate that even small changes in the molecular structure of substituted benzene-1,3,5-tri-carboxamides affect their solid-state properties and their self-assembly behaviour in dilute solutions. PMID:19142935

Stals, Patrick J M; Smulders, Maarten M J; Martín-Rapún, Rafael; Palmans, Anja R A; Meijer, E W

2009-01-01

84

Expansion of nanosized pores in low-crystallinity nanoparticle-assembled plates via a thermally induced increase in solid-state density.  

PubMed

We investigated thermally induced changes in a low-crystallinity hydroxyapatite (HAp)-nanoparticle-assembled plate containing nanosized pores. We first prepared an aqueous dispersion of low-crystallinity HAp nanoparticles (particle size, 48 nm) via a wet chemical process and then prepared the nanoparticle-assembled plate by drying the dispersion on an oil substrate to prevent crack formation. Before the plates were subjected to heat treatments, they contained 7.9-nm-sized pores because of the gap between the nanoparticles, and their porosity was 60%. After the heat treatments (600-1100 °C) were performed for 1 h, the solid-state density determined using helium pycnometry increased from 2.85 to 3.21 g/cm(3), and the pore size increased from 7.9 to 250 nm. These results indicate that the pore size expanded because of increases in crystallinity and density, despite the large decrease in the total volume because of thermally induced sintering of the nanoparticles. PMID:23777865

Okada, Masahiro; Fujiwara, Keiko; Uehira, Mayo; Matsumoto, Naoyuki; Takeda, Shoji

2013-05-31

85

Octameric Stoichiometry of the KATP Channel Complex  

Microsoft Academic Search

ATP-sensitive potassium (K ATP ) channels link cellular metabolism to electrical activity in nerve, mus- cle, and endocrine tissues. They are formed as a functional complex of two unrelated subunits—a member of the Kir inward rectifier potassium channel family, and a sulfonylurea receptor (SUR), a member of the ATP-binding cassette transporter family, which includes cystic fibrosis transmembrane conductance regulators and

S.-L. Shyng; C. G. Nichols

1997-01-01

86

Statistical mechanics of ecosystem assembly.  

PubMed

We introduce a toy model of ecosystem assembly for which we are able to map out all assembly pathways generated by external invasions. The model allows us to display the whole phase space in the form of an assembly graph whose nodes are communities of species and whose directed links are transitions between them induced by invasions. We characterize the process as a finite Markov chain and prove that it exhibits a unique set of recurrent states (the end state of the process), which is therefore resistant to invasions. This also shows that the end state is independent of the assembly history. The model shares all features with standard assembly models reported in the literature, with the advantage that all observables can be computed in an exact manner. PMID:19905727

Capitán, José A; Cuesta, José A; Bascompte, Jordi

2009-10-13

87

Statistical Mechanics of Ecosystem Assembly  

NASA Astrophysics Data System (ADS)

We introduce a toy model of ecosystem assembly for which we are able to map out all assembly pathways generated by external invasions. The model allows us to display the whole phase space in the form of an assembly graph whose nodes are communities of species and whose directed links are transitions between them induced by invasions. We characterize the process as a finite Markov chain and prove that it exhibits a unique set of recurrent states (the end state of the process), which is therefore resistant to invasions. This also shows that the end state is independent of the assembly history. The model shares all features with standard assembly models reported in the literature, with the advantage that all observables can be computed in an exact manner.

Capitán, José A.; Cuesta, José A.; Bascompte, Jordi

2009-10-01

88

Valence band offset, strain and shape effects on confined states in self-assembled InAs/InP and InAs/GaAs quantum dots  

NASA Astrophysics Data System (ADS)

I present a systematic study of self-assembled InAs/InP and InAs/GaAs quantum dot single-particle and many-body properties as a function of the quantum dot–surrounding matrix valence band offset. I use an atomistic, empirical tight-binding approach and perform numerically demanding calculations for half-million-atom nanosystems. I demonstrate that the overall confinement in quantum dots is a non-trivial interplay of two key factors: strain effects and the valence band offset. I show that strain effects determine both the peculiar structure of confined hole states of lens type InAs/GaAs quantum dots and the characteristic ‘shell-like’ structure of confined hole states in the commonly considered ‘low-strain’ lens type InAs/InP quantum dot. I also demonstrate that strain leads to single-band-like behavior of hole states of disk type (‘indium flushed’) InAs/GaAs and InAs/InP quantum dots. I show how strain and valence band offset affect quantum dot many-body properties: the excitonic fine structure, an important factor for efficient entangled photon pair generation, and the biexciton and charged exciton binding energies.

>M Zieli?ski,

2013-11-01

89

Valence band offset, strain and shape effects on confined states in self-assembled InAs/InP and InAs/GaAs quantum dots.  

PubMed

I present a systematic study of self-assembled InAs/InP and InAs/GaAs quantum dot single-particle and many-body properties as a function of the quantum dot-surrounding matrix valence band offset. I use an atomistic, empirical tight-binding approach and perform numerically demanding calculations for half-million-atom nanosystems. I demonstrate that the overall confinement in quantum dots is a non-trivial interplay of two key factors: strain effects and the valence band offset. I show that strain effects determine both the peculiar structure of confined hole states of lens type InAs/GaAs quantum dots and the characteristic 'shell-like' structure of confined hole states in the commonly considered 'low-strain' lens type InAs/InP quantum dot. I also demonstrate that strain leads to single-band-like behavior of hole states of disk type ('indium flushed') InAs/GaAs and InAs/InP quantum dots. I show how strain and valence band offset affect quantum dot many-body properties: the excitonic fine structure, an important factor for efficient entangled photon pair generation, and the biexciton and charged exciton binding energies. PMID:24129261

Zieli?ski, M

2013-10-15

90

Very large assemblies: Optimizing for automatic generation of assembly sequences  

SciTech Connect

Sandia's Archimedes 3.0{copyright} Automated Assembly Analysis System has been applied successfully to several large industrial and weapon assemblies. These have included Sandia assemblies such as portions of the B61 bomb, and assemblies from external customers such as Cummins Engine Inc., Raytheon (formerly Hughes) Missile Systems and Sikorsky Aircraft. While Archimedes 3.0{copyright} represents the state-of-the-art in automated assembly planning software, applications of the software made prior to the technological advancements presented here showed several limitations of the system, and identified the need for extensive modifications to support practical analysis of assemblies with several hundred to a few thousand parts. It was believed that there was substantial potential for enhancing Archimedes 3.0{copyright} to routinely handle much larger models and/or to handle more modestly sized assemblies more efficiently. Such a mature assembly analysis capability was needed to support routine application to industrial assemblies that overstressed the system, such as full nuclear weapon assemblies or full-scale aerospace or military vehicles.

CALTON,TERRI L.

2000-02-01

91

Neural Assembly Computing  

Microsoft Academic Search

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

João Ranhel

2012-01-01

92

Evaluation of short read metagenomic assembly  

PubMed Central

Background Metagenomic assembly is a challenging problem due to the presence of genetic material from multiple organisms. The problem becomes even more difficult when short reads produced by next generation sequencing technologies are used. Although whole genome assemblers are not designed to assemble metagenomic samples, they are being used for metagenomics due to the lack of assemblers capable of dealing with metagenomic samples. We present an evaluation of assembly of simulated short-read metagenomic samples using a state-of-art de Bruijn graph based assembler. Results We assembled simulated metagenomic reads from datasets of various complexities using a state-of-art de Bruijn graph based parallel assembler. We have also studied the effect of k-mer size used in de Bruijn graph on metagenomic assembly and developed a clustering solution to pool the contigs obtained from different assembly runs, which allowed us to obtain longer contigs. We have also assessed the degree of chimericity of the assembled contigs using an entropy/impurity metric and compared the metagenomic assemblies to assemblies of isolated individual source genomes. Conclusions Our results show that accuracy of the assembled contigs was better than expected for the metagenomic samples with a few dominant organisms and was especially poor in samples containing many closely related strains. Clustering contigs from different k-mer parameter of the de Bruijn graph allowed us to obtain longer contigs, however the clustering resulted in accumulation of erroneous contigs thus increasing the error rate in clustered contigs.

2011-01-01

93

Hinge assembly  

DOEpatents

A hinge assembly having a first leaf, a second leaf and linking member. The first leaf has a contact surface. The second leaf has a first contact surface and a second contact surface. The linking member pivotally connects to the first leaf and to the second leaf. The hinge assembly is capable of moving from a closed position to an open position. In the closed position, the contact surface of the first leaf merges with the first contact surface of the second leaf. In the open position, the contact surface of the first leaf merges with the second contact surface of the second leaf. The hinge assembly can include a seal on the contact surface of the first leaf.

Vandergriff, David Houston (Powell, TN)

1999-01-01

94

Hinge assembly  

DOEpatents

A hinge assembly is disclosed having a first leaf, a second leaf and linking member. The first leaf has a contact surface. The second leaf has a first contact surface and a second contact surface. The linking member pivotally connects to the first leaf and to the second leaf. The hinge assembly is capable of moving from a closed position to an open position. In the closed position, the contact surface of the first leaf merges with the first contact surface of the second leaf. In the open position, the contact surface of the first leaf merges with the second contact surface of the second leaf. The hinge assembly can include a seal on the contact surface of the first leaf. 8 figs.

Vandergriff, D.H.

1999-08-31

95

Assembling GRETINA  

ScienceCinema

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.

96

Self-Assembled in-Plane-Gate Thin-Film Transistors Gated by WOx Solid-State Electrolytes  

NASA Astrophysics Data System (ADS)

Low-voltage WOx gated indium-zinc-oxide thin-film transistors (TFTs) with in-plane-gate structures are fabricated by using an extremely simplified one-shadow mask method at room temperature. The proton conductive WOx solid-state electrolyte is demonstrated to form an electric-double-layer (EDL) effect associated with a huge capacitance of 0.51 ?F/cm2. The special EDL capacitance of the WOx electrolyte is also extended to novel in-plane-gate structure TFTs as the gate dielectric, reducing the operating voltage to 1.8 V. Such TFTs operate at n-type depletion mode with a threshold voltage of ?0.5 V, saturation electron mobility of 13.2 cm2/V·s, ON/OFF ratio of 1.7 × 106, subthreshold swing of 110 mV/dec, and low leakage current less than 7 nA. The hysteresis window of the transfer curves is also explained by an unique reaction within the WOx electrolyte.

Zhu, De-Ming; Men, Chuan-Ling; Wan, Xiang; Deng, Chuang; Li, Zhen-Peng

2013-08-01

97

Beginning Assembly  

Microsoft Academic Search

\\u000a Now it’s time to see the efforts of your labor take shape, literally. In this and the next three chapters, we’ll walk you\\u000a through the process of assembling the basic framework of the 3D printer. The electronics (including the motors) will come\\u000a later, but for now you’ll need to grab some basic tools such as Philips and slot screwdrivers (electric\\/portable

Patrick Hood-Daniel; James Floyd Kelly

98

Los Alamos Critical Assemblies Facility  

SciTech Connect

The Critical Assemblies Facility of the Los Alamos National Laboratory has been in existence for thirty-five years. In that period, many thousands of measurements have been made on assemblies of /sup 235/U, /sup 233/U, and /sup 239/Pu in various configurations, including the nitrate, sulfate, fluoride, carbide, and oxide chemical compositions and the solid, liquid, and gaseous states. The present complex of eleven operating machines is described, and typical applications are presented.

Malenfant, R.E.

1981-06-01

99

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  

Microsoft Academic Search

Background  Out of 358000 maternal deaths that occurred globally in 2008, 57.8% occurred in continental Africa. Africa had a maternal\\u000a mortality ratio of 590 compared to 14 in developed regions, 68 in Latin America and Caribbean, and 190 in Asia. This article\\u000a reflects on the discussions held during the Fifteenth Assembly of the Heads of State and Government of the African

Luis Gomes Sambo; Joses Muthuri Kirigia; Georges Ki-Zerbo

2011-01-01

100

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

PubMed Central

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.

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

101

Thermocouple assembly  

DOEpatents

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.

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

2002-01-01

102

75 FR 47523 - Assembly of the Administrative Conference; Filing of Advisory Committee Charter  

Federal Register 2010, 2011, 2012, 2013

...ADMINISTRATIVE CONFERENCE OF THE UNITED STATES Assembly of the Administrative Conference; Filing...an advisory committee charter for the Assembly of the Administrative Conference, in...SUPPLEMENTARY INFORMATION: The purpose of the Assembly is to adopt recommendations for the...

2010-08-06

103

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  

Microsoft Academic Search

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

P. L. Garner; N. A. Hanan

2011-01-01

104

Radiation Chemistry in Organized Assemblies.  

ERIC Educational Resources Information Center

|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)|

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

1981-01-01

105

Connecting assembly and method  

Microsoft Academic Search

An apparatus and methods are described for making underwater connection of marine riser assemblies which have controlled buoyancy. Methods of assembling and using such riser assemblies in underwater drilling operations also are described. A connecting assembly communicates between a first location and a second location lower than the first location, with the 2 locations separated by a fluid body. A

Wardlaw; H. W. R

1978-01-01

106

Inlet nozzle assembly  

DOEpatents

An inlet nozzle assembly for directing coolant into the duct tube of a fuel assembly attached thereto. The nozzle assembly includes a shell for housing separable components including an orifice plate assembly, a neutron shield block, a neutron shield plug, and a diffuser block. The orifice plate assembly includes a plurality of stacked plates of differently configurated and sized openings for directing coolant therethrough in a predesigned flow pattern.

Christiansen, David W. (Kennewick, WA); Karnesky, Richard A. (Richland, WA); Precechtel, Donald R. (Richland, WA); Smith, Bob G. (Richland, WA); Knight, Ronald C. (Richland, WA)

1987-01-01

107

Inlet nozzle assembly  

DOEpatents

An inlet nozzle assembly for directing coolant into the duct tube of a fuel assembly attached thereto. The nozzle assembly includes a shell for housing separable components including an orifice plate assembly, a neutron shield block, a neutron shield plug, and a diffuser block. The orifice plate assembly includes a plurality of stacked plates of differently configurated and sized openings for directing coolant therethrough in a predesigned flow pattern.

Christiansen, D.W.; Karnesky, R.A.; Knight, R.C.; Precechtel, D.R.; Smith, B.G.

1985-09-09

108

The nucleosomal core histone octamer at 3.1 A resolution: a tripartite protein assembly and a left-handed superhelix.  

PubMed Central

The structure of the octameric histone core of the nucleosome has been determined by x-ray crystallography to a resolution of 3.1 A. The histone octamer is a tripartite assembly in which a centrally located (H3-H4)2 tetramer is flanked by two H2A-H2B dimers. It has a complex outer surface; depending on the perspective, the structure appears as a wedge or as a flat disk. The disk represents the planar projection of a left-handed proteinaceous superhelix with approximately 28 A pitch. The diameter of the particle is 65 A and the length is 60 A at its maximum and approximately 10 A at its minimum extension; these dimensions are in agreement with those reported earlier by Klug et al. [Klug, A., Rhodes, D., Smith, J., Finch, J. T. & Thomas, J. O. (1980) Nature (London) 287, 509-516]. The folded histone chains are elongated rather than globular and are assembled in a characteristic "handshake" motif. The individual polypeptides share a common central structural element of the helix-loop-helix type, which we name the histone fold. Images

Arents, G; Burlingame, R W; Wang, B C; Love, W E; Moudrianakis, E N

1991-01-01

109

Emergent multistability in assembled nanostructures.  

PubMed

Scanning tunneling microscopy (STM) at 5 K reveals that native atoms in the surface layer of a semiconductor crystal become bistable in vertical height when a nanostructure is assembled nearby. The binary switching of surface atoms, driven by the STM tip, changes their charge state. Coupling is facilitated by assembling adatom chains, allowing us to explore the emergence of complex multiple switching. Density-functional theory calculations rationalize the observations and a lattice-gas model predicts the cooperative behavior from first principles. PMID:21591678

Yang, Jianshu; Erwin, Steven C; Kanisawa, Kiyoshi; Nacci, Christophe; Fölsch, Stefan

2011-05-17

110

The physical and chemical state of Westinghouse Phosphoric Acid Fuel Cell assemblies after long term operation: Surface and near-surface analysis  

SciTech Connect

An attempt was made to correlate performance losses with materials compatibility and compositional changes in Phosphoric Acid Fuel Cell (PAFC) electrode assemblies as a function of operation time. Westinghouse PAFC stacks were run under a constant operating regime and portions of some of the single cells were analysed after stack operation for 5000 hrs and for 16,000 hrs along with appropriate reference samples. The PAFC assemblies were disassembled, sectioned where appropriate and analyzed using scanning and transmission electron microscopy (SEM and TEM), Rutherford backscattering spectroscopy (RBS), electron microprobe analysis (EMP), and x-ray photoelectron spectroscopy (XPS). The profiles of the Pt catalyst in both the anode and the cathode layer did not show any preferential loss or peaking. The most pronounced change in cell composition detected following stack operation for 5000 and for 16,000 hours was the increase in Pt/C ratio, that was related to loss of carbon from the cathode electrocatalyst. In contrast, the anode catalyst layer maintains the same ratio of Pt/C following 16,000 hours of operation. The loss of carbon is thought to occur by an electrochemical mechanism and is enhanced at the higher potentials experienced by the air cathode in the fuel cell. In addition, TEM results clearly demonstrate the well recognized phenomenon of Pt particle agglomeration in the cathode catalyst layer, which is seen to be quite substantial after 5000 hours of stack operation. The mechanical integrity of the assemblies was found to be quite satisfactory after 5000 hours, but much less so after 16,000 hours. Questions regarding carbon and Pt corrosion, Pt migration, and the mechanical and physical integrity of the PAFC structures are addressed and are all postulated to be contributing to the observed cell performance losses. 10 refs., 17 figs.

Paffett, M.T.; Hutchinson, W.; Farr, J.D.; Papin, P.; Beery, J.G.; Gottesfeld, S. (Los Alamos National Lab., NM (USA)); Feret, J. (Westinghouse Electric Corp., Pittsburgh, PA (USA))

1990-01-01

111

Firearm trigger assembly  

SciTech Connect

A firearm trigger assembly for use with a firearm includes a trigger mounted to a forestock of the firearm so that the trigger is movable between a rest position and a triggering position by a forwardly placed support hand of a user. An elongated trigger member operatively associated with the trigger operates a sear assembly of the firearm when the trigger is moved to the triggering position. An action release assembly operatively associated with the firearm trigger assembly and a movable assembly of the firearm prevents the trigger from being moved to the triggering position when the movable assembly is not in the locked position.

Crandall, David L. (Idaho Falls, ID); Watson, Richard W. (Blackfoot, ID)

2010-02-16

112

Seal assembly releasing tool  

SciTech Connect

A seal assembly releasing tool is shown having an outer support case and an inner unlocking element rotatably mounted on a shaft and coupled by a planetary gear train. The seal assembly is provided with cam surfaces into which cam followers latch for securely connecting the tool to the seal assembly and enabling the outer case to turn the assembly in one direction while the inner element turns the locking sleeve of the seal assembly in the other direction to release the seal assembly.

Woodman, D.C.

1984-02-14

113

Composite Silver Forming Assembly.  

National Technical Information Service (NTIS)

This patent application relates to prearranged ribbons of fiber leaving the front drafting roll which are superimposed into layers by a composite sliver forming assembly before entering a trumpet. The composite sliver forming assembly consists of tubular ...

R. S. Brown C. L. Shepard L. J. Richard

1975-01-01

114

Saddle Clamp Assembly.  

National Technical Information Service (NTIS)

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 oppo...

C. R. Belrose

1992-01-01

115

Role of the protective antigen octamer in the molecular mechanism of anthrax lethal toxin stabilization in plasma.  

PubMed

Anthrax is caused by strains of Bacillus anthracis that produce two key virulence factors, anthrax toxin (Atx) and a poly-gamma-D-glutamic acid capsule. Atx is comprised of three proteins: protective antigen (PA) and two enzymes, lethal factor (LF) and edema factor (EF). To disrupt cell function, these components must assemble into holotoxin complexes, which contain either a ring-shaped homooctameric or homoheptameric PA oligomer bound to multiple copies of LF and/or EF, producing lethal toxin (LT), edema toxin, or mixtures thereof. Once a host cell endocytoses these complexes, PA converts into a membrane-inserted channel that translocates LF and EF into the cytosol. LT can assemble on host cell surfaces or extracellularly in plasma. We show that, under physiological conditions in bovine plasma, LT complexes containing heptameric PA aggregate and inactivate more readily than LT complexes containing octameric PA. LT complexes containing octameric PA possess enhanced stability, channel-forming activity, and macrophage cytotoxicity relative to those containing heptameric PA. Under physiological conditions, multiple biophysical probes reveal that heptameric PA can prematurely adopt the channel conformation, but octameric PA complexes remain in their soluble prechannel configuration, which allows them to resist aggregation and inactivation. We conclude that PA may form an octameric oligomeric state as a means to produce a more stable and active LT complex that could circulate freely in the blood. PMID:20433851

Kintzer, Alexander F; Sterling, Harry J; Tang, Iok I; Abdul-Gader, Ali; Miles, Andrew J; Wallace, B A; Williams, Evan R; Krantz, Bryan A

2010-04-28

116

Membrane module assembly  

DOEpatents

A membrane module assembly is described which is 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. 2 figures.

Kaschemekat, J.

1994-03-15

117

Managing Coil Epoxy Vacuum Impregnation Systems at the Manufacturing Floor Level to Achieve Ultimate Properties in State of the Art Magnet Assemblies.  

National Technical Information Service (NTIS)

Liquid epoxy resin impregnation systems remain a state-of-the-art polymer material for vacuum and vacuum/pressure impregnation applications in the manufacture of both advanced and conventional coil winding configurations. Epoxy resins inherent latitude in...

J. G. Hubrig G. H. Biallas

2005-01-01

118

Managing Coil Epoxy Vacuum Impregnation Systems at the Manufacturing Floor Level To Achieve Ultimate Properties in State-of-the-Art Magnet Assemblies.  

National Technical Information Service (NTIS)

Liquid epoxy resin impregnation systems remain a state-of-the-art polymer material for vacuum and vacuum/pressure impregnation applications in the manufacture of both advanced and conventional coil winding configurations. Epoxy resins inherent latitude in...

J. G. Hubrig G. H. Biallas

2005-01-01

119

Composite fan stator assembly  

SciTech Connect

A composite fan stator assembly is described for a gas turbine engine having at least two fan rotor stages, the composite stator assembly comprising: an annular composite fan case assembly including an access port, the fan case assembly circumferentially disposed around first and second fan rotor stage locations, a composite fan stator stage supported by and extending radially inward of the fan case assembly and axially disposed between the two fan rotor stage locations, the fan stator stage includes at least one removable vane segment accessible for removal through the access port for assembly and reassembly, the composite fan case assembly including a separable composite forward fan case assembly and a separable composite aft fan case assembly spaced axially aft of the forward fan case assembly, the forward fan case assembly being bolted to the aft fan case assembly, wherein the composite fan stator stage is axially and radially trapped and supported by the forward and aft fan case assemblies. A composite stator vane assembly comprising: a composite inner shroud, a composite outer shroud disposed radially outward of the inner shroud, a plurality of vanes disposed between the shrouds, the vanes including a suction side and a pressure side and radially inner and outer roots, the roots extending through platforms of corresponding ones of the inner and outer shrouds, four box-type attachment elements corresponding to curved suction and pressure sides of the inner and outer roots, the box-type attachment elements having two connected legs angled with respect to each other, a first one of the legs extending along, conforming to the curve of, and bonded to a corresponding one of the airfoil root sides, and a second one of the legs extending along and bonded to a composite shroud surface.

Donges, G.L.

1993-07-13

120

Photovoltaic assemblies and methods for transporting  

DOEpatents

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.

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

2013-09-17

121

Clasp assembly for jewelry  

US Patent & Trademark Office Database

A clasp assembly for jewelry to be worn as a ring or earring. As a ring, the clasp assembly for jewelry allows individuals to wear rings around finger phalanges, by locking the rings below the knuckles of the fingers without having to slide the rings over knuckles of the fingers. As an earring, the clasp assembly for jewelry allows individuals to wear an earring on various parts of the individual.

DeGolyer; BarbaraJayne (Delray Beach, FL)

2008-03-25

122

Spatio-orientationally organized polymer microstructures obtained on self-assembled pattern-forming states of liquid crystals: Morphology, phase separation, and potential applications  

NASA Astrophysics Data System (ADS)

The main objective of the dissertation is to develop and exploit a novel technique for imparting multidimensional spatial and orientational order into polymer networks. This approach is based on the use of pattern-forming states of liquid crystals as templates for the network formation. To demonstrate the feasibility and flexibility of this concept, we describe various pattern-forming states observed from ordinary cholesteric and nematic/cholesteric dual-frequency liquid crystals. We present a variety of polymer microstuctures templated on those pattern-forming states. This clearly demonstrates the feasibility and flexibility of templating both orientational and positional order of host pattern-forming states into polymer network. We investigated possible driving forces behind this templating effect of LC pattern-forming states. These include effects of both spatial variations of UV intensity and gradients in elastic distortion caused by the spatial modulation of director field. The effects of the two mechanisms are separated through a series of experiments, including polarization-selective photopolymerization, FTIR imaging of the monomer distribution prior to UV-exposure and initiation of the photoreaction, the effect of temperature on the templated morphology, and the use of a thermal reactive monomer to remove the effect of possible optical inhomogeneities. The model derives from the concept of director gradient templating, whereby monomer phase separation is driven by a competition between reduction in elastic energy when monomer replaces liquid crystal in more (or less) distorted regions of the molecular director, and a consequent decrease in the entropy of mixing of the two species. Another emphasis of this dissertation is to study the control over the network morphology in the "third" dimension---perpendicular to UV wavefront---by relatively simple means of selecting the wavelength of UV light used in photopolymerization to be inside or outside a carefully characterized absorption band. The spatial variation in polymerization rate with consequent diffusion of monomer results in surface-localized networks. The final objective is to demonstrate potential applications of LC pattern-forming states and their templating effect, including switchable phase gratings, orientational/positional pattern formation of functional materials (e.g., conducting polymers), and potentiality of this novel interaction for future research.

Kang, Shin-Woong

123

Linux Assembly HOWTO  

NSDL National Science Digital Library

This tutorial "describes how to program in assembly language using free programming tools, focusing on development for or from the Linux Operating System." For applications that are closely related to the underlying computer architecture, assembly language programming can be very important. The instructive material is aimed at people who have at least a basic understanding of conventional, high-level programming styles but have little to no experience with assembly. Hence, it serves as a general introduction to the topic, mainly useful for understanding what situations lend themselves to assembly programming.

Boldyshev, Konstantin.; Rideau, Francois-Rene.

124

The proteasome assembly line  

PubMed Central

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.

Madura, Kiran

2013-01-01

125

Quasi-solid-state dye-sensitized solar cells: Pt and PEDOT:PSS counter electrodes applied to gel electrolyte assemblies  

Microsoft Academic Search

In this paper we present an attempt to substitute liquid electrolyte (LC) dye-sensitized solar cells (DSSCs) by quasi-solid-state constructions (SC) for semi-transparency application adopting organic\\/inorganic gels in combination with standard (Pt based) and alternative (PEDOT:PSS based) counter electrodes. Gel polymer electrolytes are prepared by incorporating a liquid electrolyte into a polymer matrix such as polymethyl-methacrylate (PMMA) using propylene carbonate (PC)

Matteo Biancardo; Keld West; Frederik C. Krebs

2007-01-01

126

Centrosymmetric and Non-centrosymmetric Packing of Aligned Molecular Fibers in the Solid State Self Assemblies of Cyclodextrin-based Rotaxanes  

Microsoft Academic Search

Two [2]-rotaxanes each comprising ?-cyclodextrin as the rotor, and with either 3,3?-difluoro- or 3,3?-dichloro-stilbene as the axle and trinitrophenylamino substituents as the blocking groups at the 4- and 4?-positions, were prepared and their structures analyzed in solution and the solid state using H NMR spectroscopy and X-ray crystallography, respectively. With each rotaxane, in solution the stilbene rotates freely within the

Marta M. Cieslinski; Peter J. Steel; Stephen F. Lincoln; Christopher J. Easton

2006-01-01

127

Superstructure-dependent optical and electrical properties of an unusual face-to-face, pi-stacked, one-dimensional assembly of dehydrobenzo[12]annulene in the crystalline state.  

PubMed

To develop a novel pi-conjugated molecule-based supramolecular assembly, we designed and synthesized trisdehydrotribenzo[12]annulene ([12]DBA) derivative 2 with three carboxyl groups at the periphery. Recrystallization of 2 from DMSO gave a crystal of the solvate 23 DMSO. Crystallographic analysis revealed, to our surprise, that a face-to-face pi-stacked one-dimensional (1D) assembly of 2 was achieved and that the DMSO molecule played a significant role as a "structure-dominant element" in the crystal. This is the first example of [12]DBA to stack completely orthogonal to the columnar axis. To reveal its superstructure-dependent optical and electrical properties, 2 and its parent molecule 1, which crystallizes in a herringbone fashion, were subjected to fluorescence spectroscopic analysis and charge-carrier mobility measurements in crystalline states. The 1D stacked structure of 2 provides a red-shifted, broadened, weakened fluorescence profile (lambda(max) = 545 nm, phi(F) = 0.01), compared to 1 (lambda(max) = 491 nm, phi(F) = 0.12), due to strong interactions between the p orbitals of the stacked molecules. The charge-carrier mobility of the single crystal of 23 DMSO, as well as 1, was determined by flash photolysis time-resolved microwave conductivity (FP-TRMC) measurements. The single crystal of 23 DMSO revealed significantly-anisotropic charge mobility (sigma(mu) = 1.5x10(-1) cm(2) V(-1) s(-1)) along the columnar axis (crystallographic c axis). This value is 12 times larger than that along the orthogonal axis (the a axis). PMID:18399533

Hisaki, Ichiro; Sakamoto, Yuu; Shigemitsu, Hajime; Tohnai, Norimitsu; Miyata, Mikiji; Seki, Shu; Saeki, Akinori; Tagawa, Seiichi

2008-01-01

128

A?(16-22) Peptides Can Assemble into Ordered ?-Barrels and Bilayer ?-Sheets, while Substitution of Phenylalanine 19 by Tryptophan Increases the Population of Disordered Aggregates.  

PubMed

A recent experimental study reported that termini-uncapped A?(16-22) (with sequence KLVFFAE) peptides self-assembled into nanofibrils at pH 2.0. The oligomerization of this uncapped peptide at atomic level in acidic pH condition remains to be determined, as computational studies mainly focus on the self-assembly of capped A?(16-22) peptides at neutral pH condition. In this study, using replica exchange molecular dynamics (REMD) simulations with explicit solvent, we investigated the octameric structures of the uncapped A?(16-22) and its F19W variant at acidic pH condition. Our simulations reveal that the A?(16-22) octamers adopt various conformations, including closed ?-barrels, bilayer ?-sheets, and disordered aggregates. The closed ?-barrel conformation is particularly interesting, as the cylindrical ?-barrel has been reported recently as a cytotoxic species. Interpeptide contact probability analyses between all pairs of residues reveal that the hydrophobic and aromatic stacking interactions between F19 residues play an essential role in the formation of ?-barrels and bilayer ?-sheets. The importance of F19 and the steric effect on the structures of A?(16-22) octamers are further examined by REMD simulation of F19W mutant. This REMD run shows that substitution of F19 by W with a more bulky aromatic side chain significantly reduces the ?-sheet content and in turn enhances the population of disordered aggregates, indicating that the steric effect significantly affect the self-assembly of low molecular weight A?(16-22) oligomers. PMID:23926957

Xie, Luogang; Luo, Yin; Wei, Guanghong

2013-08-26

129

On constraints in assembly planning  

Microsoft Academic Search

Constraints on assembly plans vary depending on product, assembly facility, assembly volume, and many other factors. Assembly costs and other measures to optimize vary just as widely. To be effective, computer-aided assembly planning systems must allow users to express the plan selection criteria that apply to their products and production environments. We begin by surveying the types of user criteria,

Rondall E. Jones; Randall H. Wilson; Terri L. Calton

1998-01-01

130

Assembly system facility design  

Microsoft Academic Search

This paper addresses the design of an assembly system facility consisting of multiple assembly lines of different shapes. In such a design problem there are two conflicting objectives: (i) to minimize the overall area of the facility; and (ii) to maximize the efficiency of the material handling transportation system. We first address the optimization problem of objective (ii) when replacing

Yossi Bukchin; Russell D. Meller; Qi Liu

2006-01-01

131

Rotary Shaft Sealing Assembly.  

National Technical Information Service (NTIS)

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...

L. L. Dietle J. E. Schroeder M. S. Kalsi P. D. Alvarez

2004-01-01

132

Rotary shaft sealing assembly  

Microsoft Academic Search

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

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

2010-01-01

133

Subsea wellhead connection assembly  

Microsoft Academic Search

A wellhead connector assembly for use on undersea template platform where a plurality of wellheads are connected to a center work enclosure hull having a plurality of penetration connectors projecting from its sidewall. The present assembly has a connector for fitting on the wellhead, and a laterally movable connector for coupling with a penetration connector. A vertical actuation rod pivots

1985-01-01

134

Mechanical seal assembly  

Microsoft Academic Search

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

Kotlyar; Oleg M

2002-01-01

135

Mechanical seal assembly  

Microsoft Academic Search

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

Kotlyar; Oleg M

2001-01-01

136

Mechanical Seal Assembly  

Microsoft Academic Search

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

Kotlyar; Oleg M

1999-01-01

137

Sequence Assembly with CAFTOOLS  

Microsoft Academic Search

Large-scale genomic sequencing requires a software infrastructure to support and integrate applications that are not directly compatible. We describe a suite of software tools built around the Common Assembly Format (CAF), a comprehensive representation of a sequence assembly as a text file. These tools form the backbone of sequencing informatics at the Sanger Centre and the Genome Sequencing Center. The

Simon Dear; Richard Durbin; LaDeana Hillier; Gabor Marth; Jean Thierry-Mieg; Richard Mott

1998-01-01

138

Fuel assembly with a removable end fitting  

SciTech Connect

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.

Jabsen, F.S.

1980-06-17

139

Constrained space camera assembly  

DOEpatents

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.

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

1999-01-01

140

Superconductive radiofrequency window assembly  

DOEpatents

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.

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

1998-05-19

141

Assembly of Multi-Element, Ultra Low Background, Germanium Spectrometer for Two Neutrino Double Beta Decay to the Excited State and Materials Assay  

NASA Astrophysics Data System (ADS)

Envisioned array of 16 70 percent, plus two, Germanium detectors with one being a 85 percent ^76Ge enriched detector. Efforts over the past ten to fifteen years in radio purity, shielding, and pulse shape discrimination come to bear. Technology and experience from previous experiments like the International Germanium Experiment (IGEX). This array will explore excited state double beta decay, in addition to segmented detector operation. As well as materials screening for future zero neutrino double beta decay effective mass. This is a summary of progress in construction. Acknowledgments: SEGA constructed by Triangle Universities Nuclear Laboratory, support by DOE. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy under Contract DE-AC06-76RL01830.

Kephart, Jeremy

2003-10-01

142

Managing Coil Epoxy Vacuum Impregnation Systems at the Manufacturing Floor Level To Achieve Ultimate Properties in State-of-the-Art Magnet Assemblies  

SciTech Connect

Liquid epoxy resin impregnation systems remain a state-of-the-art polymer material for vacuum and vacuum/pressure impregnation applications in the manufacture of both advanced and conventional coil winding configurations. Epoxy resins inherent latitude in processing parameters accounts for their continued popularity in engineering applications, but also for the tendency to overlook or misinterpret the requisite processing parameters on the manufacturing floor. Resin system impregnation must be managed in detail in order to achieve device life cycle reliability. This closer look reveals how manufacturing floor level management of material acceptance, handling and storage, pre- and post- impregnation processing and cure can be built into a manufacturing plan to increase manufacturing yield, lower unit cost and ensure optimum life cycle performance of the coil.

J.G. Hubrig; G.H. Biallas

2005-05-01

143

8-Hydroxypyrene-1,3,6-trisulphonate and octanesulphonate co-assembled layered double hydroxide and its controllable solid-state luminescence by hydrothermal synthesis  

SciTech Connect

8-Hydroxy-pyrene-1,3,6-trisulphonate (HPTS) and octanesulphonate (OS) have been co-intercalated into the ZnAl layered double hydroxide (LDH) host by a hydrothermal co-precipitation method, with samples denoted as HPTS (x%)-OS/Zn{sub 2}Al-LDH (x stands for the molar percentage content of HPTS with respect to total amount of HPTS and OS). The structure and chemical compositions of the as-prepared compounds were characterized by X-ray diffraction (XRD) and elemental analysis. The steady-state and time-decay fluorescent studies show that HPTS (2%)-OS/Zn{sub 2}Al-LDH has the optimal luminous emission and the longest fluorescent lifetime. Moreover, these samples exhibit controllable dual fluorescence between the blue and green regions upon changing the interlayer HPTS content, external pH values, and host-guest interaction, illustrating that these organic-inorganic samples have potential application in the field of tunable solid luminescent materials. - Graphical Abstract: 8-Hydroxy-pyrene-1,3,6-trisulphonate and octanesulfonate co-intercalated ZnAl layered double hydroxide can exhibit tunable solid-state blue and green fluorescence by treating the sample at acid and neutral media under hydrothermal condition. Highlights: Black-Right-Pointing-Pointer 8-hydroxy-pyrene-1,3,6-trisulphonate (HPTS) was intercalated into ZnAl LDHs. Black-Right-Pointing-Pointer They show the controllable dual fluorescence response to the HPTS content and pH values. Black-Right-Pointing-Pointer Fluorescence of the HPTS/LDH film was insensitive to the quencher (Cu{sup 2+}) concentration.

Dang Sile; Yan Dongpeng [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Lu Jun, E-mail: lujun@mail.buct.edu.cn [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

2012-01-15

144

Electrical Cable Molded Seal Assembly.  

National Technical Information Service (NTIS)

This invention relates to an electrical cable molded seal assembly for sealing an electrical cable penetration through a bulkhead. The assembly includes a housing, follower, clamp plate, retaining disc, conductor rods and a molded seal assembly. The elect...

K. J. Miner R. D. Gorman

1980-01-01

145

8-Hydroxypyrene-1,3,6-trisulphonate and octanesulphonate co-assembled layered double hydroxide and its controllable solid-state luminescence by hydrothermal synthesis  

NASA Astrophysics Data System (ADS)

8-Hydroxy-pyrene-1,3,6-trisulphonate (HPTS) and octanesulphonate (OS) have been co-intercalated into the ZnAl layered double hydroxide (LDH) host by a hydrothermal co-precipitation method, with samples denoted as HPTS (x%)-OS/Zn2Al-LDH (x stands for the molar percentage content of HPTS with respect to total amount of HPTS and OS). The structure and chemical compositions of the as-prepared compounds were characterized by X-ray diffraction (XRD) and elemental analysis. The steady-state and time-decay fluorescent studies show that HPTS (2%)-OS/Zn2Al-LDH has the optimal luminous emission and the longest fluorescent lifetime. Moreover, these samples exhibit controllable dual fluorescence between the blue and green regions upon changing the interlayer HPTS content, external pH values, and host-guest interaction, illustrating that these organic-inorganic samples have potential application in the field of tunable solid luminescent materials.

Dang, Sile; Yan, Dongpeng; Lu, Jun

2012-01-01

146

Cluster-assembled metallic glasses.  

PubMed

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

Kartouzian, Aras

2013-07-30

147

Cluster-assembled metallic glasses  

NASA Astrophysics Data System (ADS)

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.

Kartouzian, Aras

2013-07-01

148

Filter assembly for pipelines  

US Patent & Trademark Office Database

A filter assembly is disclosed for use in connection with the filtration of products transported via pipelines, including high pressure gas pipelines. The disclosed filter assembly is comprised of a plurality of filter modules, a series of valves, inlet and outlet ports, connective piping, and spool pieces. The filter assembly will temporarily redirect flow from the pipeline, through one or more filter assemblies, and back into the original pipeline a short distance downstream from the original takeout point. If flanged connections are not readily available for a particular section of pipeline, the filter assembly can be connected to virtually any section of pipe through "hot tapping" technology, which allows a valve to be placed on an active and pressurized section of pipeline. The filter assembly of the present invention allows the operator to replace expired filtering members by shifting product flow from one filter module to another, thereby avoiding the need to take the pipeline out of service during filtering operations. The filter assembly may also be mounted on a skid and/or a mobile trailer.

2007-05-29

149

DC source assemblies  

DOEpatents

Embodiments of DC source assemblies of power inverter systems of the type suitable for deployment in a vehicle having an electrically grounded chassis are provided. An embodiment of a DC source assembly comprises a housing, a DC source disposed within the housing, a first terminal, and a second terminal. The DC source also comprises a first capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the first terminal. The DC source assembly further comprises a second capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the second terminal.

Campbell, Jeremy B; Newson, Steve

2013-02-26

150

TPX assembly plan  

SciTech Connect

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.

Knutson, D.

1993-11-01

151

United Nations General Assembly  

NSDL National Science Digital Library

The UN Department of Public Information has recently created a site which features comprehensive information on its General Assembly. The core of the site is a collection of facts and documents relating to the current (52nd) meeting of the General Assembly. Users find the Agenda and Programme of Work, recent press releases, links to documents, and information on committees, elections, and appointments. Information and documents from previous regular and special sessions are also available. An added feature is a general description of the Assembly itself: its background, functions, sessions, and main committees.

152

Fuel injector assembly  

SciTech Connect

This patent describes a fuel injector assembly for a low pressure fuel injection system of an internal combustion engine. It comprises: check valve means for receiving a flow of fuel from a fuel supply system and for transmitting the fuel into a crankcase of an internal combustion engine, the check valve means including an inlet end and an outlet end; fastener housing means for supporting the check valve means and for securing a reed valve block assembly to a location at which the reed valve block assembly opens into the crankcase of the internal combustion engine; and a hollow passageway in the fastener housing means.

Staerzl, R.E.; Stageman, R.D.

1990-05-08

153

Effects of calcination treatment on the morphology, crystallinity, and photoelectric properties of all-solid-state dye-sensitized solar cells assembled by TiO2 nanorod arrays.  

PubMed

TiO2 has been extensively investigated due to its unique photoelectric properties. In this study, oriented single-crystal rutile TiO2 nanorod arrays were synthesized and then calcined at different temperatures in the atmosphere. The morphology and crystalline characterization indicated that the length of TiO2 nanorods increased rapidly and the nanorods became aggregated and fragile after calcination, yet the sintering treatment seemed to have almost no effect on the crystallinity. To obtain the all-solid-state, dye-sensitized solar cells (DSSCs), a newly reported solid inorganic semiconductor, CsSnI2.95F0.05, was employed as the electrolyte, and the Pt deposited on the conductive side of the fluorine-doped tin oxide (FTO) glass substrate was used as the counter-electrode. The effects of the calcination treatment on the photoelectric properties of the solar cells, including external quantum efficiency (EQE), open circuit voltage (VOC), short-circuit current (JSC), and photoelectric conversion efficiency (?), were investigated under the illumination of a solar simulator. As a result, all of the EQE, VOC, JSC, and ? values of the cells first increased and then declined with the increase of calcination temperatures, and the highest ? of 2.81% was obtained by the cell assembled with its TiO2 electrode sintered at 450 °C for 3 h, a value almost 2.5 times that of the non-sintered sample (1.1%). PMID:24071636

Sun, Xianmiao; Sun, Qiong; Li, Yang; Sui, Lina; Dong, Lifeng

2013-10-01

154

Assemble time for self-assembling square tiles  

Microsoft Academic Search

As technology drives components smaller, tradi- tional methods of assembling these components become ever more impractical. Self-assembly is a viable solution in which the individual components autonomously organize themselves without the external guidance of a supervising agent. In this paper we look at the assembly times for various one and two dimensional objects that are assembled with square tiles in

James Solberg

155

Inverse Problem in Self-assembly  

NASA Astrophysics Data System (ADS)

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.

Tkachenko, Alexei

2012-02-01

156

Core assembly storage structure  

DOEpatents

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.

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

1988-01-01

157

Steam separator latch assembly  

DOEpatents

A latch assembly removably joins a steam separator assembly to a support flange disposed at a top end of a tubular shroud in a nuclear reactor pressure vessel. The assembly includes an annular head having a central portion for supporting the steam separator assembly thereon, and an annular head flange extending around a perimeter thereof for supporting the head to the support flange. A plurality of latches are circumferentially spaced apart around the head flange with each latch having a top end, a latch hook at a bottom end thereof, and a pivot support disposed at an intermediate portion therebetween and pivotally joined to the head flange. The latches are pivoted about the pivot supports for selectively engaging and disengaging the latch hooks with the support flange for fixedly joining the head to the shroud or for allowing removal thereof. 12 figures.

Challberg, R.C.; Kobsa, I.R.

1994-02-01

158

Microtubule Self- Assembly  

NASA Astrophysics Data System (ADS)

Microtubules are important structural elements for neurons. Microtubles are cylindrical pipes that are self-assembled from tubulin dimers, These structures are intimately related to the neuron transport system. Abnormal microtubule disintegration contributes to neuro-disease. For several decades, experimentalists investigated the structure of the microtubules using TEM and Cryo-EM. However, the detailed structure at a molecular level remain incompletely understood. . In this presentation, we report numerically studies of the self-assembly process using a toy model for tubulin dimers. We investigate the nature of the interactions which are essential to stabilize such the cylindrical assembly of protofilaments. We use Monte Carlo simulations to suggest the pathways for assembly and disassembly of the microtubules.

Jho, Yongseok; Choi, M. C.; Farago, O.; Kim, Mahnwon; Pincus, P. A.

2008-03-01

159

Robotic assembly system  

US Patent & Trademark Office Database

A robotic assembly system for the automatic assembly of a complex article such as a CRT display unit has a number of workstations positioned along an open conveyor system at each of which as assembly operation is performed by a conventional stand-alone robot. Each workstation is provided with a basic lift mechanism (36, 17, 21, 24, 28) which when operated lifts a pallet (4) supplied thereto from the relatively imprecise surface of the conveyor (1) into a predetermined horizontal plane above the conveyor where it is accurately located. A stand-alone robot, programmed to operate with reference to this constant datum position performs the assembly operation associated with that workstation. In order to assist the assembly operation, an air bearing table (17) is incorporated in the lift mechanism to provide the pallet, and any article carried by the pallet, with lateral compliance while held at the datum position. On completion of the assembly operation, the lift mechanism is retracted, lowering the pallet back onto the conveyor for transportation to the next workstation. The invention is particularly suited for assembly operations involving the handling of potentially hazardous components such as, for example, CRTs during the assembly of a display motor. A modification to the basic lift mechanism enables the assembly of a CRT into its surrounding bezel to be performed. The modification includes the addition of a further lift device (35, 38) which, when operated, lifts a platform (30) through an aperture (34) in the pallet into a second predetermined horizontal plane. To perform the assembly operation, a pallet (4) already supporting a part-cabinet (8) including its bezel surround (9) as a result of a previous assembly operation, is raised into the first datum position. The platform is then raised into the second datum position above the first. A stand-alone robot, programmed to operate with reference to the second datum places and releases a CRT face-plate down on the platform. The platform is then lowered back through the aperture in the pallet leaving the CRT supported in the bezel surround. The pallet is finally lowered onto the conveyor for transportation to the next workstation.

1990-02-20

160

High speed door assembly  

DOEpatents

This invention is comprised of a high speed door assembly, 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.

Shapiro, C.

1991-12-31

161

AMTRI accelerates assembly automation  

Microsoft Academic Search

Purpose – This paper seeks to investigate the work of a small company involved in researching techniques and designing equipment for assembly automation. Design\\/methodology\\/approach – The development of a fully automated CNC machine for drilling aircraft wing sub-assemblies is described. The importance of accurate process simulation is discussed, and a research project combining physics-based gaming hardware with factory simulation software

Christine Connolly

2007-01-01

162

Dynamics of magnetic nano-particle assembly  

Microsoft Academic Search

Ferromagnetically coupled nano-particle assembly is analyzed accounting for inter- and intra- particle electronic structures within the randomly jumping interacting moments model including quantum fluctuations due to the discrete levels and disorder. At the magnetic jump anomalies caused by quantization the magnetic state equation and phase diagram are found to indicate an existence of spinodal regions and critical points. Arrays of

V. N. Kondratyev

2010-01-01

163

Technology for the assembly and testing of space vehicles  

NASA Astrophysics Data System (ADS)

The technological aspects of the assembly, testing, and control of state-of-the-art space vehicles and their components are examined. In particular, attention is given to the assembly of sealed and nonsealed compartments, tanks, and truss structures; fabrication of space vehicle components, panels, and compartments of composite materials; application of thermal insulation coatings; and functional and strength testing of space vehicle components and systems. The discussion also covers pneumatic and hydraulic testing of space vehicle assemblies, determination of the moments of inertia, final assembly of space vehicles, electrical testing of space vehicle systems, and solution of technological problems in the design of space vehicles.

Beliakov, Ivan T.; Zernov, Igor'a.; Antonov, Evgenii G.; Baklunov, A. M.; Bronfman, V. Iu.; Voitkov, N. I.; Gorbunov, N. M.; Zaretskii, Iu. M.; Isachenko, V. A.; Kulik, Iu. P.

164

Human Assisted Assembly Processes  

SciTech Connect

Automatic assembly sequencing and visualization tools are valuable in determining the best assembly sequences, but without Human Factors and Figure Models (HFFMs) it is difficult to evaluate or visualize human interaction. In industry, accelerating technological advances and shorter market windows have forced companies to turn to an agile manufacturing paradigm. This trend has promoted computerized automation of product design and manufacturing processes, such as automated assembly planning. However, all automated assembly planning software tools assume that the individual components fly into their assembled configuration and generate what appear to be a perfectly valid operations, but in reality the operations cannot physically be carried out by a human. Similarly, human figure modeling algorithms may indicate that assembly operations are not feasible and consequently force design modifications; however, if they had the capability to quickly generate alternative assembly sequences, they might have identified a feasible solution. To solve this problem HFFMs must be integrated with automated assembly planning to allow engineers to verify that assembly operations are possible and to see ways to make the designs even better. Factories will very likely put humans and robots together in cooperative environments to meet the demands for customized products, for purposes including robotic and automated assembly. For robots to work harmoniously within an integrated environment with humans the robots must have cooperative operational skills. For example, in a human only environment, humans may tolerate collisions with one another if they did not cause much pain. This level of tolerance may or may not apply to robot-human environments. Humans expect that robots will be able to operate and navigate in their environments without collisions or interference. The ability to accomplish this is linked to the sensing capabilities available. Current work in the field of cooperative automation has shown the effectiveness of humans and machines directly interacting to perform tasks. To continue to advance this area of robotics, effective means need to be developed to allow natural ways for people to communicate and cooperate with robots just as they do with one another.

CALTON,TERRI L.; PETERS,RALPH R.

2000-01-01

165

Electrochemical Cell Assembled in Discharged State.  

National Technical Information Service (NTIS)

The patent application relates to high-temperature, secondary electrochemical cells and batteries of such cells that can be employed as power sources for electrical automobiles, hybrid electric vehicles or for the storage of energy generated during interv...

N. P. Yao W. J. Walsh

1974-01-01

166

VideoLab: Assembling a Nanowheel  

NSDL National Science Digital Library

Self-assembly is a powerful means of preparing structurally intricate nanomaterials. However, the challenge of forming large, ring-shaped nanomolecules this way is entropically steep. By using a flow reactor system, Miras et al. observed how (3.5 nm in diameter) form with the help of temporary template molecules. These transient templates form, help assemble the ring-shaped molecules around them, and then leave once the wheel is fully formed and reduced to its final electronic state. This animation shows a model of the templating process.

Haralampos N. Miras (The University of Glasgow, Glasgow;WestCHEM, Department of Chemistry); Geoffrey J. T. Cooper (The University of Glasgow, Glasgow;WestCHEM, Department of Chemistry); De-Liang Long (The University of Glasgow, Glasgow;WestCHEM, Department of Chemistry); Hartmut Bogge (Fakultät für Chemie, Universität Bielefeld, Postfach ;); Achim Muller (Fakultät für Chemie, Universität Bielefeld, Postfach ;); Carsten Streb (The University of Glasgow, Glasgow;WestCHEM, Department of Chemistry)

2010-01-01

167

Superconducting radiofrequency window assembly  

DOEpatents

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.

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

1997-01-01

168

Superconductive radiofrequency window assembly  

DOEpatents

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.

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

1998-01-01

169

Photovoltaic self-assembly.  

SciTech Connect

This late-start LDRD was focused on the application of chemical principles of self-assembly on the ordering and placement of photovoltaic cells in a module. The drive for this chemical-based self-assembly stems from the escalating prices in the 'pick-and-place' technology currently used in the MEMS industries as the size of chips decreases. The chemical self-assembly principles are well-known on a molecular scale in other material science systems but to date had not been applied to the assembly of cells in a photovoltaic array or module. We explored several types of chemical-based self-assembly techniques, including gold-thiol interactions, liquid polymer binding, and hydrophobic-hydrophilic interactions designed to array both Si and GaAs PV chips onto a substrate. Additional research was focused on the modification of PV cells in an effort to gain control over the facial directionality of the cells in a solvent-based environment. Despite being a small footprint research project worked on for only a short time, the technical results and scientific accomplishments were significant and could prove to be enabling technology in the disruptive advancement of the microelectronic photovoltaics industry.

Lavin, Judith; Kemp, Richard Alan; Stewart, Constantine A.

2010-10-01

170

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

171

60. SUPPORT CARRIAGE ASSEMBLY AT ISLIP CANYON SHOWING CURVED RAILS ...  

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

60. SUPPORT CARRIAGE ASSEMBLY AT ISLIP CANYON SHOWING CURVED RAILS AND FLOATING BARGE IN BACKGROUND, February 16, 1948. - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

172

68. COMPLETED ASSEMBLY SHOWING BARGES, BRIDGE AND SUPPORT CARRIAGE AT ...  

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

68. COMPLETED ASSEMBLY SHOWING BARGES, BRIDGE AND SUPPORT CARRIAGE AT THE BASE OF THE LAUNCHING SLAB LOOKING EAST, April 26, 1948. - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

173

Power module assembly  

DOEpatents

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.

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

2011-11-15

174

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

Federal Register 2010, 2011, 2012, 2013

...CONFERENCE OF THE UNITED STATES Meeting of the Assembly of the Administrative Conference AGENCY...notice is hereby given of a meeting of the Assembly of the Administrative Conference of the...meeting in plenary session constitutes the Assembly of the Conference (5 U.S.C....

2010-11-23

175

Experimental study of natural convection heat transfer from an enclosed assembly of thin vertical cylinders  

Microsoft Academic Search

Steady state heat transfer by natural convection was investigated experimentally from an enclosed assembly of thin vertical cylinders at high Rayleigh numbers. The published literature lacks any information regarding such a study in the turbulent boundary layer regime. All the available literature is for the laminar region for an enclosed assembly. The enclosed assembly consisted of a 3 × 3 array of

Muhammad Arshad; Mansoor Hameed Inayat; Imran Rafiq Chughtai

2011-01-01

176

Low inductance connector assembly  

DOEpatents

A busbar connector assembly for coupling first and second terminals on a two-terminal device to first and second contacts on a power module is provided. The first terminal resides proximate the first contact and the second terminal resides proximate the second contact. The assembly comprises a first bridge having a first end configured to be electrically coupled to the first terminal, and a second end configured to be electrically coupled to the second contact, and a second bridge substantially overlapping the first bridge and having a first end electrically coupled to the first contact, and a second end electrically coupled to the second terminal.

Holbrook, Meghan Ann; Carlson, Douglas S

2013-07-09

177

Assembling an aesthetic.  

PubMed

Recent research informing and related to the study of three-dimensional scientific models is assembled here in a way that explores an aesthetic, specifically, of touch. I concentrate on the materiality of models, drawing on insights from the history and philosophy of science, design and metaphysics. This article chronicles the ways in which touch, or material interactions, operate in the world of 3D models, and its role in what models mean and do. I end with a call for greater attention to scientific process, described as assembly of and within science, which is revealed by this focus on touch. PMID:23176974

Candela, Emily

2012-11-21

178

Subsea wellhead connection assembly  

SciTech Connect

A wellhead connector assembly for use on undersea template platform where a plurality of wellheads are connected to a center work enclosure hull having a plurality of penetration connectors projecting from its sidewall. The present assembly has a connector for fitting on the wellhead, and a laterally movable connector for coupling with a penetration connector. A vertical actuation rod pivots a bell crank linked to the connector to cause lateral movement thereof. A loop of pipe connects the wellhead to the laterally movable connector and biases it to a neutral position.

Miller, H. W.

1985-05-21

179

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

Microsoft Academic Search

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

Nadia Trieselmann; Sheri Armstrong; Jennifer Rauw; Andrew Wilde

2003-01-01

180

Lean staged combustion assembly  

Microsoft Academic Search

This patent describes a lean staged combustion assembly. It comprises: means for channeling compressed air including a pilot portion and a main portion. This patent also describes an annular combustor outer liner having an upstream end and a downstream end; an annular combustor inner liner having an upstream end and a downstream end and spaced from the outer liner; means

P. E. Sabla; W. J. Dodds; T. M. Tucker

1992-01-01

181

Cutter bit assembly  

SciTech Connect

A cutter bit assembly comprises a holder and a cutter bit. The holder is formed with a pocket into which the cutter bit can be inserted. The cutter bit is retained within the pocket by means of an arcuate wedge inserted into a tapered gap formed between respective curved support faces formed on the cutter bit and the holder.

Merten, G.; Breuer, O.; Hesse, N.; Steinkuhl, B.

1984-06-26

182

Solar collector assembly  

SciTech Connect

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.

Murphy, J.A.

1980-09-09

183

Pull Rod Assembly.  

National Technical Information Service (NTIS)

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 in...

O. C. Cioletti

1988-01-01

184

Connecting assembly and method  

Microsoft Academic Search

Diclosed is a connecting assembly for communicating between a first location and a second location lower than the first location, with the two locations separated by a fluid body. A first tube extending between the two locations generally encloses a second tube, and the annular area between adjacent surfaces of the two tubes is sealed toward the second location. The

Wardlaw

1980-01-01

185

Rotary shaft sealing assembly  

DOEpatents

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.

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

2013-08-13

186

Rotary shaft sealing assembly  

DOEpatents

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.

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

2010-09-21

187

Corium protection assembly  

DOEpatents

A corium protection assembly includes a perforated base grid disposed below a pressure vessel containing a nuclear reactor core and spaced vertically above a containment vessel floor to define a sump therebetween. A plurality of layers of protective blocks are disposed on the grid for protecting the containment vessel floor from the corium.

Gou, Perng-Fei (Saratoga, CA); Townsend, Harold E. (Campbell, CA); Barbanti, Giancarlo (Sirtori, IT)

1994-01-01

188

Subsea wellhead assembly  

Microsoft Academic Search

A subsea wellhead assembly for areas subject to iceberg scouring including an upper conductor in a well bore and a lower conductor in the well bore with the upper end of the lower conductor being within the lower end of the upper conductor and connected thereto by a weak connection and the upper end of the lower conductor being below

1984-01-01

189

Subsea wellhead seal assembly  

Microsoft Academic Search

An annular subsea wellhead seal assembly is described for sealing against the walls in a subsea wellhead annulus above a landing seat at the lower end of the annulus comprising: an annular body having an outwardly and downwardly flaring outer skirt and an inwardly and downwardly flaring inner skirt extending from it slower surface, a landing ring having lower landing

Gullion

1988-01-01

190

VISTA Structured Assembler.  

National Technical Information Service (NTIS)

VISTA is a structured assembly language for the VIPER microprocessor chip. Though the syntax of VISTA and the appearance of VISTA programs are reminiscent of a high-level language, the actual statements are VIPER machine instructions. VISTA provides the c...

J. Kershaw

1992-01-01

191

ASSEMBLING MEDIA CULTURE  

Microsoft Academic Search

In this paper, I consider the problematic of assembling culture from the standpoint of media. Specifically I take the example of mobile media – emergent digital networked technologies that centre on cellular mobile networks, but also intersect with other technologies such as the Internet and portable music and video devices. My particular interest is in these new assemblages of media

Gerard Goggin

2009-01-01

192

Rotatable seal assembly  

Microsoft Academic Search

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

Clinton M. Logan; Jack L. Garibaldi

1982-01-01

193

Gas turbine combustion assembly  

Microsoft Academic Search

An improved gas turbine engine combustor assembly particularly for automotive application including a primary reaction chamber disposed in a pressurized air plenum of the engine, fixed area air flow ports between the reaction chamber and the plenum, a prechamber housing at an upstream end of the reaction chamber having an annular fixed area air passage between the plenum and the

W. Cornelius; E. D. Klomp

1984-01-01

194

Modeling Protein Self Assembly  

ERIC Educational Resources Information Center

|Understanding the structure and function of proteins is an important part of the standards-based science curriculum. Proteins serve vital roles within the cell and malfunctions in protein self assembly are implicated in degenerative diseases. Experience indicates that this topic is a difficult one for many students. We have found that the concept…

Baker, William P.; Jones, Carleton Buck; Hull, Elizabeth

2004-01-01

195

Packaging Predictable Assembly  

Microsoft Academic Search

Significant economic and technical benefits accrue from the use of pre-existing and commercially available software components to develop new systems. However, challenges remain that, if not adequately addressed, will slow the adoption of software component technology. Chief among these are a lack of consumer trust in the quality of components, and a lack of trust in the quality of assemblies

Scott A. Hissam; Gabriel A. Moreno; Judith A. Stafford; Kurt C. Wallnau

2002-01-01

196

Quantitative Proteomic Analysis of Ribosome Assembly and Turnover In Vivo  

PubMed Central

Although high-resolution structures of the ribosome have been solved in a series of functional states, relatively little is known about how the ribosome assembles, particularly in vivo. Here, a general method is presented for studying the dynamics of ribosome assembly and ribosomal assembly intermediates. Since significant quantities of assembly intermediates are not present under normal growth conditions, the antibiotic neomycin is used to perturb wild type E. coli. Treatment of E. coli with the antibiotic neomycin results in the accumulation of a continuum of assembly intermediates for both the 30S and 50S subunits. The protein composition and the protein stoichiometry of these intermediates were determined by quantitative mass spectrometry using purified unlabeled and 15N-labeled wild type ribosomes as external standards. The intermediates throughout the continuum are heterogeneous and are largely depleted of late-binding proteins. Pulse labeling with 15N-labeled medium timestamps the ribosomal proteins based on their time of synthesis. The assembly intermediates contain both newly synthesized proteins and proteins that originated in previously synthesized intact subunits. This observation requires either a significant amount of ribosome degradation, or the exchange or reuse of ribosomal proteins. These specific methods can be applied to any system where ribosomal assembly intermediates accumulate, including strains with deletions or mutations of assembly factors. This general approach can be applied to study the dynamics of assembly and turnover of other macromolecular complexes that can be isolated from cells.

Sykes, Michael T.; Shajani, Zahra; Sperling, Edit; Beck, Andrea H.; Williamson, James R.

2010-01-01

197

Valve Drive Electronics Assembly (VDA).  

National Technical Information Service (NTIS)

The design of a prototype redundant valve drive electronics assembly (VDA) is discussed. The VDA is used as part of the modular attitude and control system for the electrical actuation and monitoring of spacecraft reaction control assemblies (RCA). The ma...

M. Aulagnon M. Duban M. Reinhalter

1978-01-01

198

Flexible Printed Circuit Board Assembly.  

National Technical Information Service (NTIS)

A flexible printed circuitry board assembly has a plurality of rigid printed circuit boards spaced apart but mechanically and electrically connected by a thin flexible printed circuitry board which is bonded to one side of each rigid board. The assembled ...

R. W. Kraft

1978-01-01

199

Extended Use of Macro Assemblers.  

National Technical Information Service (NTIS)

The techniques developed for the use of macro assemblers are described. An assembler (specifically IBMAP) is used in a fashion apparently not intended by the originators. Programs written using the described techniques are written and debugged in a remark...

R. A. Magnuson

1965-01-01

200

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

...beneficiary country in whole of U.S. components or ingredients; articles assembled...beneficiary country from textile components cut to shape in the United States...Assembled Abroad with United States Components § 10.26 Articles...

2010-04-01

201

Algorithmic DNA Self-assembly  

Microsoft Academic Search

Self-assembly is the ubiquitous process by which objects autonomously assemble into complexes. This phenomenon is common in\\u000a nature and yet is poorly understood from mathematical and programming perspectives. It is believed that self-assembly technology\\u000a will ultimately permit the precise fabrication of complex nanostructures. Of particular interest is DNA self-assembly. Double\\u000a and triple crossover DNA molecules have been designed that can

Ming-yang Kao

2006-01-01

202

A framework for geometric reasoning about tools in assembly  

SciTech Connect

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.

Wilson, R.H.

1995-12-31

203

Fabrication Equipment for Periodic Material Assemblies and Ph Assemblies and Photonic Crystals (DURIP FY06).  

National Technical Information Service (NTIS)

This report describes the purchased equipment to establish two laboratories at the Ohio State Univ. for the fabrication of a novel class of periodic assemblies (PAs) intended to emulate anisotropic media. Such media have already been shown to lead to nove...

H. Verweij J. L. Volakis R. M. Reano

2008-01-01

204

HIV1 assembly in macrophages  

Microsoft Academic Search

The molecular mechanisms involved in the assembly of newly synthesized Human Immunodeficiency Virus (HIV) particles are poorly understood. Most of the work on HIV-1 assembly has been performed in T cells in which viral particle budding and assembly take place at the plasma membrane. In contrast, few studies have been performed on macrophages, the other major target of HIV-1. Infected

Philippe Benaroch; Elisabeth Billard; Raphaël Gaudin; Michael Schindler; Mabel Jouve

2010-01-01

205

ASSEMBLY TRANSFER SYSTEM DESCRIPTION DOCUMENT  

Microsoft Academic Search

The Assembly Transfer System (ATS) receives, cools, and opens rail and truck transportation casks from the Carrier\\/Cask Handling System (CCHS). The system unloads transportation casks consisting of bare Spent Nuclear Fuel (SNF) assemblies, single element canisters, and Dual Purpose Canisters (DPCs). For casks containing DPCs, the system opens the DPCs and unloads the SNF. The system stages the assemblies, transfer

B. Gorpani

2000-01-01

206

Molded Bobbin Head Coil Assembly.  

National Technical Information Service (NTIS)

The patent application relates to the head coil assembly for a missile. Positioned within the interior of the head coil assembly is an optical gyroscope, such as disclosed in the co-pending application. The head coil assembly contains the reactor coils, p...

R. M. Van Zyl

1974-01-01

207

Efficient charge transport in semisynthetic zinc chlorin dye assemblies.  

PubMed

We have studied the charge transport properties of self-assembled structures of semisynthetic zinc chlorins (ZnChls) in the solid state by pulsed radiolysis time-resolved microwave conductivity measurements. These materials can form either a two-dimensional (2D) brickwork-type slipped stack arrangement or a one-dimensional (1D) tubular assemblies, depending on the exact molecular structure of the ZnChls. We have observed efficient charge transport with mobilities as high as 0.07 cm(2) V(-1) s(-1) for tubular assemblies of 3(1)-hydroxy ZnChls and up to 0.28 cm(2) V(-1) s(-1) for 2D stacked assemblies of 3(1)-methoxy ZnChls at room temperature. The efficient charge transporting capabilities of these organized assemblies opens the way to supramolecular electronics based on biological systems. PMID:22985422

Patwardhan, Sameer; Sengupta, Sanchita; Siebbeles, Laurens D A; Würthner, Frank; Grozema, Ferdinand C

2012-09-21

208

19 CFR 10.16 - Assembly abroad.  

Code of Federal Regulations, 2010 CFR

...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...

2009-04-01

209

19 CFR 10.16 - Assembly abroad.  

Code of Federal Regulations, 2010 CFR

...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...

2010-04-01

210

Printed Wiring Assembly and Interconnection Reliability.  

National Technical Information Service (NTIS)

This report presents reliability prediction models for printed wiring assemblies, solderless wrap assemblies, wrapped and soldered assemblies, and discrete wiring assemblies w/electroless deposited PTH for inclusion in MIL-HDBK-217. Collected field failur...

D. W. Coit

1981-01-01

211

Subsea wellhead seal assembly  

SciTech Connect

An annular subsea wellhead seal assembly is described for sealing against the walls in a subsea wellhead annulus above a landing seat at the lower end of the annulus comprising: an annular body having an outwardly and downwardly flaring outer skirt and an inwardly and downwardly flaring inner skirt extending from it slower surface, a landing ring having lower landing surface for landing on a landing seat at the lower end of the subsea wellhead annulus in which the assembly is to seal, and an upper flat reaction surface which is positioned immediately under and engagable with the lower ends of the skirts; and means connecting the body and the landing ring for relative movement toward each other; downward movement of the body with respect to the landing ring spreading the skirts outward and inward, respectively, into a substantially horizontal digging engagement set position with the walls of the annulus to be sealed.

Gullion, S.D.

1988-07-26

212

Infrared floodlight assembly  

DOEpatents

An infrared floodlight assembly (10) including a cast aluminum outer housing (11) defining a central chamber (15) therein. A floodlight (14), having a tungsten halogen lamp as the light source, is spacedly positioned within a heat conducting member (43) within chamber (15) such that the floodlight is securedly positioned in an aligned manner relative to the assembly's filter (35) and lens (12) components. The invention also includes venting means (51) to allow air passage between the interior of the member (43) and the adjacent chamber (15), as well as engagement means (85) for engaging a rear surface of the floodlight (14) to retain it firmly against an internal flange of the member (43). A reflector (61), capable of being compressed to allow insertion or removal, is located within the heat conducting member's interior between the floodlight (14) and filter (35) to reflect infrared radiation toward the filter (35) and spaced lens (12).

Wierzbicki, Julian J. (Peabody, MA); Chakrabarti, Kirti B. (Danvers, MA)

1987-09-22

213

Low inductance busbar assembly  

DOEpatents

A busbar assembly for electrically coupling first and second busbars to first and second contacts, respectively, on a power module is provided. The assembly comprises a first terminal integrally formed with the first busbar, a second terminal integrally formed with the second busbar and overlapping the first terminal, a first bridge electrode having a first tab electrically coupled to the first terminal and overlapping the first and second terminals, and a second tab electrically coupled to the first contact, a second bridge electrode having a third tab electrically coupled to the second terminal, and overlapping the first and second terminals and the first tab, and a fourth tab electrically coupled to the second contact, and a fastener configured to couple the first tab to the first terminal, and the third tab to the second terminal.

Holbrook, Meghan Ann (Manhattan Beach, CA)

2010-09-21

214

Metalceramic joint assembly  

Microsoft Academic Search

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

Jian

2002-01-01

215

Nuclear fuel assembly  

SciTech Connect

First nuclear fuel elements in which a fissionable material in which a burnable poison is incorporated is loaded and second nuclear fuel elements in which a fissionable material in which no burnable poison is incorporated is loaded are disposed in a nuclear fuel assembly. Content of the fissionable material in the first nuclear fuel element is less than about 72% of that of the fissionable material in the second nuclear fuel element adjacent to the first nuclear fuel element.

Hosokawa, T.; Maki, H.; Shinbo, K.

1982-10-19

216

Pull rod assembly  

SciTech Connect

This patent describes a pull rod assembly. It comprises: a pull rod having three peripheral grooves, a piston device including an adaptor ring and a seal ring. The piston device is 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.

Cioletti, O.C.

1990-05-22

217

Guided assembly of nanostructures  

Microsoft Academic Search

A solid solution can spontaneously separate into phases, e.g. spinodal decomposition, that self assemble into patterns. This process can be guided via external fields to form ordered micro- and nano-structures, e.g., nanodots and nanowires. A Cahn-Hilliard type phase field model is developed that incorporates chemical, interfacial, and elastic energies, including heterogeneous elastic properties, and that couples naturally to externally-imposed mechanical

Yucun Lou

2009-01-01

218

Disconnectable production riser assembly  

SciTech Connect

A production riser assembly for producing oil to a floating platform includes a central riser and plurality of production risers annularly spaced around the central riser. The central riser has a flexible joint with a hydraulic connector therebelow. Each production riser has a flexible hose at lower end which is connectable to flowline subs located in spaced relation from the central riser connector. Hydraulically operated connectors are located at the bottom end of each flexible pipe, each riser is independently tensioned.

Hettinger, F.L.

1983-08-09

219

Microtubule Self Assembly  

Microsoft Academic Search

Microtubules are important structural elements for neurons. Microtubles are cylindrical pipes that are self-assembled from tubulin dimers, These structures are intimately related to the neuron transport system. Abnormal microtubule disintegration contributes to neuro-disease. For several decades, experimentalists investigated the structure of the microtubules using TEM and Cryo-EM. However, the detailed structure at a molecular level remain incompletely understood. . In

Yongseok Jho; M. C. Choi; O. Farago; Mahnwon Kim; P. A. Pincus

2008-01-01

220

Pull rod assembly  

DOEpatents

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.

Cioletti, O.C.

1988-04-21

221

Alkane Self Assembling  

NASA Astrophysics Data System (ADS)

Self-assembling of organic molecules has awaken scientific and technological interest. In this work we study the self-assembling process of long chain hydrocarbons, mainly n-dotriacontane (n-C32H66). We dip-coated C32 monolayers onto silicon wafers covered by their native silicon oxide layer (Si(100)/SiO2). Our results show that withdrawing speed affects the coverage and morphology of the C32 films. For slow withdrawing speeds, alkanes formed islands with a dragon-fly shape, while for fast withdrawing alkanes assembled in stripes with widths in the order of microns. When we quantified coverage and morphology versus withdrawing speed, we found an inflection, which we associate with a transition between two film deposition kinetics. These transitions have been previously described by de Gennes [1]. For slow withdrawing, film deposition follows the Langmuir-Blodget process and above a threshold speed, solution on the solid enters a Landau-Levich regime. This work opens the possibility for growing microstructures with nanometric thickness using a very simple method. These organic microstructures could be used as templates or as grids for optical diffraction. [0pt] [1] P.G. de Gennes, Colloid & Polymer Sci. 264, 463-465 (1986).

Corrales, Tomas; Homm, Pia; Ferrari, Piero; Retamal, Maria Jose; Del Campo, Valeria; Volkmann, Ulrich G.

2011-03-01

222

Nanoparticle assemblies as memristors.  

PubMed

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

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

223

OH Module Assembly Stand  

SciTech Connect

There is an OR module assembly stand in use at IB4. This design has been approved by safety, as presented by Mike Foley, and has been successfully used. Another one is needed at the D-zero assembly building, but some modifications need to be made. This report will show that the new modified design is at least as strong, if not stronger, than the older IB4 design in every aspect. Since the weight distribution of the OR modules on the sling is indeterminate, this report compares three cases of support for the entire assembly: the lowest two beams only, the lowest four beams only, and all six beams. In each of these cases, the new design is stronger than the old design in maximum allowable weight. The ability of the the cradle to support the weight is also shown. For all of the failure conditions except for two, the cradle is stronger than the beams that it supports. In the two excepted situations, the calculated limit of the cradle is less than the beams it supports. This is because no credit is taken for the sling and strongback, which in reality will relieve much of the horizontal load.

Bolan, P.J.; /Fermilab

1990-10-16

224

Genetic assembly rules and community phenotypes  

Microsoft Academic Search

We present a conceptual construct for a genetic based community assembly rule where the genetic composition of a host plant,\\u000a or resource, affects the structure of the dependent community. This is related to a genetic similarity rule that states that\\u000a host plants with similar genetic compositions are hosts to similar arthropod communities. We present preliminary data from\\u000a the Populus system

Randy K. Bangert; Thomas G. Whitham

2007-01-01

225

Nuclear core and fuel assemblies  

DOEpatents

A fast flux nuclear core of a plurality of rodded, open-lattice assemblies having a rod pattern rotated relative to a rod support structure pattern. Elongated fuel rods are oriented on a triangular array and laterally supported by grid structures positioned along the length of the assembly. Initial inter-assembly contact is through strongbacks at the corners of the support pattern and peripheral fuel rods between adjacent assemblies are nested so as to maintain a triangular pitch across a clearance gap between the other portions of adjacent assemblies. The rod pattern is rotated relative to the strongback support pattern by an angle .alpha. equal to sin .sup.-1 (p/2c), where p is the intra-assembly rod pitch and c is the center-to-center spacing among adjacent assemblies.

Downs, Robert E. (Monroeville, PA)

1981-01-01

226

Engineered Self-Assembly of Plasmonic Nanomaterials  

NASA Astrophysics Data System (ADS)

A critical need in nanotechnology is the development of new tools and methods to organize, connect, and integrate solid-state nanocomponents. Self-assembly -- where components spontaneously organize themselves -- can be carried out on a massively parallel scale to construct large-scale architectures using solid-state nanocrystal building blocks. I will present our recent work on the synthesis and self-assembly of nanocrystals for plasmonics, where light is propagated, manipulated, and confined by solid-state components that are smaller than the wavelength of light itself. We show the organization of polymer-grafted metal nanocrystals into hierarchical nanojunction arrays that possess intense ``hot spots'' due to electromagnetic field localization. We also show that doped semiconductor nanocrystals can serve as a new class of plasmonic building blocks, where shape and carrier density can be actively tuned to engineer plasmon resonances. These examples demonstrate that nanocrystals possess unique electromagnetic properties that rival top-down structures, and the potential of self-assembly for fabricating designer plasmonic materials.

Tao, Andrea

2013-03-01

227

Self-assembly from milli- to nanoscales: methods and applications  

PubMed Central

The design and fabrication techniques for microelectromechanical systems (MEMS) and nanodevices are progressing rapidly. However, due to material and process flow incompatibilities in the fabrication of sensors, actuators and electronic circuitry, a final packaging step is often necessary to integrate all components of a heterogeneous microsystem on a common substrate. Robotic pick-and-place, although accurate and reliable at larger scales, is a serial process that downscales unfavorably due to stiction problems, fragility and sheer number of components. Self-assembly, on the other hand, is parallel and can be used for device sizes ranging from millimeters to nanometers. In this review, the state-of-the-art in methods and applications for self-assembly is reviewed. Methods for assembling three-dimensional (3D) MEMS structures out of two-dimensional (2D) ones are described. The use of capillary forces for folding 2D plates into 3D structures, as well as assembling parts onto a common substrate or aggregating parts to each other into 2D or 3D structures, is discussed. Shape matching and guided assembly by magnetic forces and electric fields are also reviewed. Finally, colloidal self-assembly and DNA-based self-assembly, mainly used at the nanoscale, are surveyed, and aspects of theoretical modeling of stochastic assembly processes are discussed.

Mastrangeli, M; Abbasi, S; Varel, C; Van Hoof, C; Celis, J-P; Bohringer, K F

2009-01-01

228

Self-assembly from milli- to nanoscales: methods and applications.  

PubMed

The design and fabrication techniques for microelectromechanical systems (MEMS) and nanodevices are progressing rapidly. However, due to material and process flow incompatibilities in the fabrication of sensors, actuators and electronic circuitry, a final packaging step is often necessary to integrate all components of a heterogeneous microsystem on a common substrate. Robotic pick-and-place, although accurate and reliable at larger scales, is a serial process that downscales unfavorably due to stiction problems, fragility and sheer number of components. Self-assembly, on the other hand, is parallel and can be used for device sizes ranging from millimeters to nanometers. In this review, the state-of-the-art in methods and applications for self-assembly is reviewed. Methods for assembling three-dimensional (3D) MEMS structures out of two-dimensional (2D) ones are described. The use of capillary forces for folding 2D plates into 3D structures, as well as assembling parts onto a common substrate or aggregating parts to each other into 2D or 3D structures, is discussed. Shape matching and guided assembly by magnetic forces and electric fields are also reviewed. Finally, colloidal self-assembly and DNA-based self-assembly, mainly used at the nanoscale, are surveyed, and aspects of theoretical modeling of stochastic assembly processes are discussed. PMID:20209016

Mastrangeli, M; Abbasi, S; Varel, C; Van Hoof, C; Celis, J-P; Böhringer, K F

2009-07-01

229

Effects of x irradiation on microtubule assembly in vitro  

Microsoft Academic Search

Microtubular proteins isolated from beef brains were x-irradiated (500 to 30,000 rad) in the assembled or unassembled state in virto, and the effects of radiation on the samples were examined. Samples were irradiated in a water bath at 0 (ice slurry), 22 or 24, and 37°C. The assembly of microtubules was monitored by following changes in optical density at 340

R. A. Coss; J. R. Bamburg; W. C. Dewey

1981-01-01

230

On Constraints in Assembly Planning  

SciTech Connect

Constraints on assembly plans vary depending on product, assembly facility, assembly volume, and many other factors. Assembly costs and other measures to optimize vary just as widely. To be effective, computer-aided assembly planning systems must allow users to express the plan selection criteria that appIy to their products and production environments. We begin this article by surveying the types of user criteria, both constraints and quality measures, that have been accepted by assembly planning systems to date. The survey is organized along several dimensions, including strategic vs. tactical criteria; manufacturing requirements VS. requirements of the automated planning process itself and the information needed to assess compliance with each criterion. The latter strongly influences the efficiency of planning. We then focus on constraints. We describe a framework to support a wide variety of user constraints for intuitive and efficient assembly planning. Our framework expresses all constraints on a sequencing level, specifying orders and conditions on part mating operations in a number of ways. Constraints are implemented as simple procedures that either accept or reject assembly operations proposed by the planner. For efficiency, some constraints are supplemented with special-purpose modifications to the planner's algorithms. Fast replanning enables an interactive plan-view-constrain-replan cycle that aids in constraint discovery and documentation. We describe an implementation of the framework in a computer-aided assembly planning system and experiments applying the system to a number of complex assemblies, including one with 472 parts.

Calton, T.L.; Jones, R.E.; Wilson, R.H.

1998-12-17

231

Connecting assembly and method  

SciTech Connect

Diclosed is a connecting assembly for communicating between a first location and a second location lower than the first location, with the two locations separated by a fluid body. A first tube extending between the two locations generally encloses a second tube, and the annular area between adjacent surfaces of the two tubes is sealed toward the second location. The buoyancy of the assembly is selectively controlled by selectively controlling the quantity and density of fluid in the area between the tubes. In an embodiment shown, a marine drilling facility is joined to an underwater well site by a riser with a liner set and sealed therein, and gas-lift pumping is used in controlling buoyancy. In a method, a riser is set between an underwater well site and a marine well operating facility. A first segment of the well may be drilled through the riser. Casing is cemented in the well, and a liner is sealed at its bottom end to the riser. Air and jet lines are positioned in the area between the liner and the riser to control the density and quantity of fluid in that area. Continued drilling may occur through the liner and the casing. The connecting assembly may also be constructed by extending a first tube between two locations and generally enclosing a second which is anchored to the riser toward both ends and held in tension. In a method, a riser is set. Then, a liner is positioned within the riser, and anchored to the riser near the bottom of the liner. The liner is then pulled up on relative to the riser, and anchored at the top to hold the liner in tension and to prevent it from slipping downwardly relative to the riser.

Wardlaw, H. W.

1980-08-12

232

Great Basin Center for Geothermal Energy Proposal for DOE Geothermal Funding for Research to Increase Utilization of Geothermal Resources in the Western United States Assembly of a Crustal Seismic Velocity Database for the Western Great Basin  

Microsoft Academic Search

This project will assemble a three-dimensional reference seismic velocity model for the western Great Basin region of Nevada and eastern California. Exploration for hidden resources requires a realistic three-dimensional crustal model to understand the deep sources of geothermal heat in the crust. The type of rule-based representations developed by the Southern California Earthquake Center (SCEC) are very appropriate to defining

John N. Louie

233

BIOCHEMISTRY: Dicey Assemblies  

NSDL National Science Digital Library

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.

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

2008-01-11

234

Wheel suspension assembly  

US Patent & Trademark Office Database

In an independent wheel suspension assembly using a parallelogrammic linkage between the vehicle infrastructure and the wheel mounting member, a damper or shock absorber is mounted in a substantially horizontal position between an anchor point on the vehicle infrastructure and a levering bracket extending from the upper or lower arm of the parallelogrammic linkage. The horizontal placement of the damper lowers the overall profile of the vehicle and provides a convenient way for adjusting its elevation in relation to the wheels without affecting the damping characteristics of the suspension. The invention is particularly applicable to remotely controlled model racing cars.

Banse; Robert J. (Imperial Beach, CA)

1992-04-28

235

Controlling plasmon coupling in biomolecule-linked metal nanoparticle assemblies  

NASA Astrophysics Data System (ADS)

Molecular control of plasmon coupling is investigated in biomolecule-linked nanoparticle assemblies in two-particle, small cluster, and extended network formats. The relationship between structure and optical properties is explored through comparison of measured spectra with simulated spectra calculated using structural models based upon measured structural parameters. A variety of techniques are used to characterize nanoparticle assemblies, including ensemble extinction and elastic scattering spectroscopy, single-assembly scattering spectroscopy, transmission electron microscopy, and dynamic light scattering. Initially, molecular control of plasmon coupling is investigated in ˜100 nm assemblies composed of 13 nm gold "satellite" particles tethered by duplex DNA to a 50 nm gold "core" particle. Comparison of core-satellite assemblies formed with duplex DNA tethers of varying length demonstrates that, while core-satellite separation is controlled by the number of base pairs in the DNA tether, structural properties such as core:satellite ratio and yield are independent of DNA tether length. Thus, plasmon coupling within these assemblies is determined by the number of base pairs in the duplex DNA tether; compact assemblies in which tethers are composed of fewer base pairs exhibit plasmon bands that are red-shifted relative to the bands of extended assemblies, indicating increased plasmon coupling in the compact assemblies. Subsequently, core-satellite assemblies are formed with reconfigurable DNA nanostructure tethers that modulate interparticle separation in response to a molecular stimulus. Assembly reconfiguration from a compact to an extended state results in blue-shifting of the assembly plasmon resonance, indicating reduced interparticle coupling and lengthening of the core-satellite tether. Comparison between measured and simulated spectra revealed a close correspondence and provided validation of the structural models that link assembly plasmonic properties with DNA control of interparticle separation. Plasmon coupling is investigated also in binary metal systems. A new method for forming stable oligonucleotide-silver conjugates is presented, and controlled plasmon coupling is observed in reconfigurable core-satellite assemblies composed of 20 nm silver satellites linked to a 50 nm gold core by DNA tethers. Reconfiguration of the DNA linkers from a compact to an extended state results in decreased plasmon coupling and a blue-shift of the gold core plasmon resonance, similar to the response observed in analogous structures formed with gold satellites. Simulations of structures composed of gold and silver cores and satellites are performed to determine how the optical properties of binary metal assemblies may differ from those composed of a single metal. It appears that gold plasmons are systematically red shifted by silver particles, whereas plasmons supported by silver particles appear differentially sensitive to gold particles according to whether the silver particle is in a core position or a satellite shell. Next, the plasmonic properties of immobilized binary nanoparticle assemblies that incorporate a single strongly scattering component that acts as a template for assembly of weakly scattering plasmonic particles are investigated. Assemblies are composed of a streptavidin-coated gold "core" nanoparticle and BSA-biotin-coated gold or silver "satellite" particles. Through correlation of measured and simulated spectra, the dependence of assembly optical properties upon satellite coverage and satellite orientation about the core is addressed. It appears that plasmon coupling in gold core-gold satellite structures depends upon satellite orientation about the core and can manifest as either peak shifting or peak splitting, while the gold plasmon response to silver satellite assembly appears to be independent of satellite orientation. Finally, binary coupling is studied in one-dimensional particle pairs and three-dimensional extended networks composed of gold and silver particl

Sebba, David S.

236

Installation and assembly device and method of using  

DOEpatents

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.

Kolsun, George J. (Pittsburgh, PA)

1997-01-01

237

Solid state switch  

DOEpatents

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.

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

1994-01-01

238

Estimation of the diffusion-limited rate of microtubule assembly.  

PubMed Central

Microtubule assembly is a complex process with individual microtubules alternating stochastically between extended periods of assembly and disassembly, a phenomenon known as dynamic instability. Since the discovery of dynamic instability, molecular models of assembly have generally assumed that tubulin incorporation into the microtubule lattice is primarily reaction-limited. Recently this assumption has been challenged and the importance of diffusion in microtubule assembly dynamics asserted on the basis of scaling arguments, with tubulin gradients predicted to extend over length scales exceeding a cell diameter, approximately 50 microns. To assess whether individual microtubules in vivo assemble at diffusion-limited rates and to predict the theoretical upper limit on the assembly rate, a steady-state mean-field model for the concentration of tubulin about a growing microtubule tip was developed. Using published parameter values for microtubule assembly in vivo (growth rate = 7 microns/min, diffusivity = 6 x 10(-12) m2/s, tubulin concentration = 10 microM), the model predicted that the tubulin concentration at the microtubule tip was approximately 89% of the concentration far from the tip, indicating that microtubule self-assembly is not diffusion-limited. Furthermore, the gradients extended less than approximately 50 nm (the equivalent of about two microtubule diameters) from the microtubule tip, a distance much less than a cell diameter. In addition, a general relation was developed to predict the diffusion-limited assembly rate from the diffusivity and bulk tubulin concentration. Using this relation, it was estimated that the maximum theoretical assembly rate is approximately 65 microns/min, above which tubulin can no longer diffuse rapidly enough to support faster growth. Images FIGURE 1

Odde, D J

1997-01-01

239

Gas separation membrane module assembly  

Microsoft Academic Search

A gas-separation membrane module assembly and a gas-separation process using the assembly. The assembly includes a set of tubes, each containing gas-separation membranes, arranged within a housing. The housing contains a tube sheet that divides the space within the housing into two gas-tight spaces. A permeate collection system within the housing gathers permeate gas from the tubes for discharge from

Nicholas P Wynn; Donald A. Fulton

2009-01-01

240

Gas separation membrane module assembly  

DOEpatents

A gas-separation membrane module assembly and a gas-separation process using the assembly. The assembly includes a set of tubes, each containing gas-separation membranes, arranged within a housing. The housing contains a tube sheet that divides the space within the housing into two gas-tight spaces. A permeate collection system within the housing gathers permeate gas from the tubes for discharge from the housing.

Wynn, Nicholas P (Palo Alto, CA); Fulton, Donald A. (Fairfield, CA)

2009-03-31

241

Supramolecular Assembly of Biohybrid Photoconversion Systems  

SciTech Connect

Self-assembled membrane architectures have great potential for the development of materials for the conversion of solar energy into electricity or fuels. Discovering the design principles that promote self-assembly in natural photosynthetic systems may provide inspiration for the development of synthetic solar conversion systems. We report for the first time that naturally occurring light harvesting antennae can alter the phase behavior of a poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (PEO-PPO-PEO) block copolymer system from micellar to lamellar structures mimicking their role in maintaining the supramolecular architecture of the photosynthetic membrane. Small-angle neutron scattering shows that PEO{sub 43}-PPO{sub 16}-PEO{sub 43} micelles undergo a phase transition from a micellar state to a lamellar structure with a {approx}60 {angstrom} spatial repetition in the presence of plant light harvesting complex II (LHCII). In addition, spectrophotometric analysis indicates that the protein self-assembles in the synthetic membrane structure. Photodependent hydrogen production mediated by LHCII embedded in the block copolymer had a maximum rate of 6.4 {micro}mol h{sup -1} per mg chlorophyll. The production of H{sub 2} was sustained for greater than 100 hours showing the potential of this approach for the development of self-assembled bioinspired photoconversion systems. Although excited energy transfer is the primary function of LHCII, this work provides evidence that the protein complex can also perform electron transfer, a role not known to occur in vivo. The significance of this work is that it provides a novel approach for developing a new class of membrane-based smart material with a well-controlled architecture that is dependent on the assembly of interacting components, and it could also have important implications in self-repair and control of energy transfer in photoconversion devices.

Cardoso, Mateus B [ORNL; Smolensky, Dmitriy [ORNL; Heller, William T [ORNL; Hong, Kunlun [ORNL; O'Neill, Hugh Michael [ORNL

2011-01-01

242

Counterbalanced refueling arm assembly  

SciTech Connect

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.

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

1990-02-06

243

Microtopographical assembly of cardiomyocytes.  

PubMed

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

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

2011-08-24

244

Microchannel heat sink assembly  

DOEpatents

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 watertight 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. 13 figs.

Bonde, W.L.; Contolini, R.J.

1992-03-24

245

Measuring electrode assembly  

DOEpatents

A pH measuring electrode assembly for immersion in a solution includes an enclosed cylindrical member having an aperture at a lower end thereof. An electrolyte is located in the cylindrical member above the level of the aperture and an electrode is disposed in this electrolyte. A ring formed of an ion porous material is mounted relative to the cylindrical member so that a portion of this ring is rotatable relative to and is covering the aperture in the cylindrical member. A suitable mechanism is also provided for indicating which one of a plurality of portions of the ring is covering the aperture and to keep track of which portions of the ring have already been used and become clogged. Preferably, the electrode assembly also includes a glass electrode member in the center thereof including a second electrolyte and electrode disposed therein. The cylindrical member is resiliently mounted relative to the glass electrode member to provide for easy rotation of the cylindrical member relative to the glass electrode member for changing of the portion of the ring covering the aperture.

Bordenick, John E. (West Mifflin, PA)

1989-01-01

246

Bottom head assembly  

DOEpatents

A bottom head dome assembly is described which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome. The bottom head dome has a plurality of openings extending there through. The liner also has a plurality of openings extending there through, 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 there through, 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 there through, and each support stub bore aligns with a respective bottom head dome opening. 2 figs.

Fife, A.B.

1998-09-01

247

Bottom head assembly  

DOEpatents

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.

Fife, Alex Blair (San Jose, CA)

1998-01-01

248

Microchannel heat sink assembly  

DOEpatents

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.

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

1992-01-01

249

Anisotropic Self-Assembly of Nanoparticle Amphiphiles  

NASA Astrophysics Data System (ADS)

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.

Kumar, Sanat

2009-03-01

250

Magnetically Undetectable Electronic Circuit Assemblies.  

National Technical Information Service (NTIS)

This report describes the results of work concerned with fabricating, electronic circuit assemblies which are undetectable magnetically, and contains recommendations concerning further development work. (Author)

H. Morris

1980-01-01

251

Next-generation transcriptome assembly  

SciTech Connect

Transcriptomics studies often rely on partial reference transcriptomes that fail to capture the full catalog of transcripts and their variations. Recent advances in sequencing technologies and assembly algorithms have facilitated the reconstruction of the entire transcriptome by deep RNA sequencing (RNA-seq), even without a reference genome. However, transcriptome assembly from billions of RNA-seq reads, which are often very short, poses a significant informatics challenge. This Review summarizes the recent developments in transcriptome assembly approaches - reference-based, de novo and combined strategies-along with some perspectives on transcriptome assembly in the near future.

Martin, Jeffrey A.; Wang, Zhong

2011-09-01

252

Shape Remodeling Assemblies in Biologically Inspired Materials  

NASA Astrophysics Data System (ADS)

Much of our research is inspired by, and directed at, understanding the formation of novel structures (both relatively static and highly dynamic) with distinct shapes and morphologies observed in charged biological systems. The structures, in turn, often correlate to specific functions. For example, charged nanoscale tubules and rods and their assemblies are of interest in a range of applications, including as templates for hierarchical nanostructures, encapsulation systems, and biosensors. A series of studies will be described on charged biological assemblies exhibiting ``molecularly-triggered'' dynamical shape changes. In particular, we will focus on protein and lipid based nanotubule formation through small molecule stimuli-induced shape remodeling events. The systems include invertible protein nanotubes from two-state tubulin-protein building blocks and lipid nanotubes and nanorods from curvature stabilizing lipids (mimicking membrane curvature generating proteins).

Safinya, Cyrus

2013-03-01

253

Method and apparatus for assembling a permanent magnet pole assembly  

DOEpatents

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.

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

254

Mechanisms of kinetic trapping in self-assembly and phase transformation  

PubMed Central

In self-assembly processes, kinetic trapping effects often hinder the formation of thermodynamically stable ordered states. In a model of viral capsid assembly and in the phase transformation of a lattice gas, we show how simulations in a self-assembling steady state can be used to identify two distinct mechanisms of kinetic trapping. We argue that one of these mechanisms can be adequately captured by kinetic rate equations, while the other involves a breakdown of theories that rely on cluster size as a reaction coordinate. We discuss how these observations might be useful in designing and optimising self-assembly reactions.

Hagan, Michael F.; Elrad, Oren M.; Jack, Robert L.

2011-01-01

255

Conformational changes in the hepatitis B virus core protein are consistent with a role for allostery in virus assembly.  

PubMed

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. PMID:19939922

Packianathan, Charles; Katen, Sarah P; Dann, Charles E; Zlotnick, Adam

2009-11-25

256

Digital assembly system design for printing press  

Microsoft Academic Search

Through analyzing deficiencies of the traditional assembly process design, and applying Design For Assembly (DFA) and digital assembly technology, the functional structure of a three-dimensional assembly system is proposed and studied. Based on the secondary development technology of SolidWorks, the virtual assembly system for a typical printing press is designed. Applications of key technologies are explored, which include the capture

Gao Bo; Zhang XiaoGui

2011-01-01

257

Photovoltaic cell assembly  

DOEpatents

A photovoltaic assembly for converting high intensity solar radiation into electrical 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. 2 figs.

Beavis, L.C.; Panitz, J.K.G.; Sharp, D.J.

1989-09-26

258

Photovoltaic cell assembly  

DOEpatents

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.

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

1990-01-01

259

Well slip assemblies  

SciTech Connect

There is disclosed an hydraulically set well packer wherein sleeves carried about a tubular member which is connected as part of a tubing string are adapted to be moved from axially extended to axially retracted position in order to expand packing and slip elements carried about one of the sleeves into engagement with the well bore in which the string is disposed. The packer also includes means which forms an atmospheric chamber including a piston on one of the sleeves, and a means for locking the sleeves in retracted position is disposed within such chamber. The slip assembly carried by the packer includes upper and lower bowls and upper and lower sets of interconnected slips which are carried by the bowls for sliding thereover between radially contracted and expanded positions in response to movement of the slip bowls toward and away from one another as the sleeves move between extended and retracted positions.

Akkerman, N.H.

1984-04-03

260

Energy storing flywheel assembly  

SciTech Connect

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.

Vestermark, L. A.

1985-08-06

261

Propulsion system assembly  

SciTech Connect

A propulsion system assembly for a vehicle is described having an engine and a nacelle disposed about the engine which has an exterior which comprises: a shroud disposed circumferentially about the nacelle which is spaced radially from the nacelle leaving an opening there between for cooling air from the exterior of the nacelle; structure which extends radially upstream of the opening to block flow from entering the opening, the structure extending between the shroud and nacelle and having at least one under cut portion forming a passage which diverges in the axial direction and which begins upstream of the opening and is bounded by an axially extending wall on the structure; wherein the passage provides a flow path to duct air from the exterior of the nacelle to a location downstream of the blocked portion of the opening on the interior of the shroud.

Zysmaan, S.H.

1993-06-08

262

Chiral Self-Assembly  

NASA Astrophysics Data System (ADS)

Chirality, the lack of reflection symmetry, at the molecular level has a profound influence on the ordering of molecular assemblages at the macroscopic scale. The example discussed here is the self-assembly of monolayers of rod-like fd virus particles, with the virus particles oriented on the average perpendicular to the plane of the layer, like a single layer of a smectic-A liquid crystal. Because these virus particles are chiral, they would prefer a twisted packing, which is incompatible with the layer structure. The twisted packing can only appear locally, at layer edges or in isolated defects in the interior of the layer. As chirality increases, the twisted regions achieve lower energy, until they can drive remarkable transformations to structures with longer edges and/or a greater number of defects.

Meyer, Robert

2012-02-01

263

Statistical mechanics of integral membrane protein assembly.  

PubMed

During the synthesis of integral membrane proteins (IMPs), the hydrophobic amino acids of the polypeptide sequence are partitioned mostly into the membrane interior and hydrophilic amino acids mostly into the aqueous exterior. Using a many-body statistical mechanics model, we analyze the minimum free energy state of polypeptide sequences partitioned into ?-helical transmembrane (TM) segments and the role of thermal fluctuations. Results suggest that IMP TM segment partitioning shares important features with general theories of protein folding. For random polypeptide sequences, the minimum free energy state at room temperature is characterized by fluctuations in the number of TM segments with very long relaxation times. Moreover, simple assembly scenarios do not produce a unique number of TM segments due to jamming phenomena. On the other hand, for polypeptide sequences corresponding to actual IMPs, the minimum free energy structure with the wild-type number of segments is free of number fluctuations due to an anomalously large gap in the energy spectrum. Now, simple assembly scenarios do reproduce the minimum free energy state without jamming. Finally, we find a threshold number of random point mutations where the size of the anomalous gap is reduced to the point that the wild-type ground state is destabilized and number fluctuations reappear. PMID:20923656

Wahba, Karim; Schwab, David; Bruinsma, Robijn

2010-10-01

264

Statistical Mechanics of Integral Membrane Protein Assembly  

PubMed Central

During the synthesis of integral membrane proteins (IMPs), the hydrophobic amino acids of the polypeptide sequence are partitioned mostly into the membrane interior and hydrophilic amino acids mostly into the aqueous exterior. Using a many-body statistical mechanics model, we analyze the minimum free energy state of polypeptide sequences partitioned into ?-helical transmembrane (TM) segments and the role of thermal fluctuations. Results suggest that IMP TM segment partitioning shares important features with general theories of protein folding. For random polypeptide sequences, the minimum free energy state at room temperature is characterized by fluctuations in the number of TM segments with very long relaxation times. Moreover, simple assembly scenarios do not produce a unique number of TM segments due to jamming phenomena. On the other hand, for polypeptide sequences corresponding to actual IMPs, the minimum free energy structure with the wild-type number of segments is free of number fluctuations due to an anomalously large gap in the energy spectrum. Now, simple assembly scenarios do reproduce the minimum free energy state without jamming. Finally, we find a threshold number of random point mutations where the size of the anomalous gap is reduced to the point that the wild-type ground state is destabilized and number fluctuations reappear.

Wahba, Karim; Schwab, David; Bruinsma, Robijn

2010-01-01

265

49 CFR 393.93 - Seats, seat belt assemblies, and seat belt assembly anchorages.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Seats, seat belt assemblies, and seat belt assembly anchorages. 393.93 Section 393...Miscellaneous Parts and Accessories § 393.93 Seats, seat belt assemblies, and seat belt assembly...

2011-10-01

266

49 CFR 393.93 - Seats, seat belt assemblies, and seat belt assembly anchorages.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Seats, seat belt assemblies, and seat belt assembly anchorages. 393.93 Section 393...Miscellaneous Parts and Accessories § 393.93 Seats, seat belt assemblies, and seat belt assembly...

2012-10-01

267

A Virtual Assembly Design Environment  

Microsoft Academic Search

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

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

1999-01-01

268

Biologically Inspired Molecular Assembly Lines  

Microsoft Academic Search

This paper proposes a biologically inspired 'molecular assembly line' — an externally programmable polymeric chain along which molecules are shuttled between chain sites along an arbitrary pathway. Our hope is to construct a scaffold that mimics biological enzymes known as polyketide synthases in their ability to physically hand-off molecules between assembly sites or domains, thereby making all chemical reactions domain-specific

B Chow; J M Jacobson

2004-01-01

269

Well-type scintillation assembly  

Microsoft Academic Search

A scintillation detector assembly is described which employs a scintillation phosphor such as a thallium activated sodium iodide crystal, wherein a blind hole is machined in the crystal to improve the efficiency of measuring the degradation rate of a radioactive material placed therein. The performance of the assembly is defined by the energy resolution of the radiation emanating from the

M. R. Farukhi; G. A. Mataraza; O. D. Wimer

1978-01-01

270

The land assembly problem revisited  

Microsoft Academic Search

As in the standard land assembly problem, a developer wants to buy two adjacent blocks of land belonging to two different owners. The value of the two blocks of land to the developer is greater than the sum of the individual values of the blocks for each owner. Unlike the land assembly literature, however, our focus is on the incentive

Flavio Menezes; Rohan Pitchford

2004-01-01

271

Shaft Seal Assembly and Method.  

National Technical Information Service (NTIS)

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 exampl...

J. E. Keba

2007-01-01

272

Full bore fracture treating assembly  

Microsoft Academic Search

A full bore fracture treating assembly is provided for use on oil and gas wells during a fracture treatment down casing to provide a full bore capability for running a casing packer or perforating gun with wellhead pressure remaining at the surface. The assembly includes a modified tubing hanger which isolates blowout preventors on the well from pressure during the

H. H. Herricks; R. L. Easterwood

1978-01-01

273

Automatic assembly planning with fasteners  

Microsoft Academic Search

The automatic assembly planning with fasteners (AAPF) prototype system is described. Given a model of a product to be manufactured, the AAPF system produces a high-level assembly sequence for producing that product. The model is defined in terms of constructive solid-geometry primitives and nut, bolt, and screw fastener primitives. The system works backwards by disassembling the finished product model. Under

Joseph M. Miller; Richard L. Hoffman

1989-01-01

274

Mechanisms of Size Control and Polymorphism in Viral Capsid Assembly  

PubMed Central

We simulate the assembly dynamics of icosahedral capsids from subunits that interconvert between different conformations (or quasi-equivalent states). The simulations identify mechanisms by which subunits form empty capsids with only one morphology, but adaptively assemble into different icosahedral morphologies around nanoparticle cargoes with varying sizes, as seen in recent experiments with brome mosaic virus (BMV) capsid proteins. Adaptive cargo encapsidation requires moderate cargo-subunit interaction strengths; stronger interactions frustrate assembly by stabilizing intermediates with incommensurate curvature. We compare simulation results to experiments with cowpea chlorotic mottle virus empty capsids and BMV capsids assembled on functionalized nanoparticles, and suggest new cargo encapsidation experiments. Finally, we find that both empty and templated capsids maintain the precise spatial ordering of subunit conformations seen in the crystal structure even if interactions that preserve this arrangement are favored by as little as the thermal energy, consistent with experimental observations that different subunit conformations are highly similar.

Elrad, Oren M.; Hagan, Michael F.

2009-01-01

275

AND/OR graph representation of assembly plans  

NASA Astrophysics Data System (ADS)

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.

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

1990-04-01

276

Biogenesis and Assembly of Eukaryotic Cytochrome c Oxidase Catalytic Core  

PubMed Central

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 which assembly is intricate and highly regulated. The COX catalytic core is formed by three mitochondrial DNA encoded subunits, Cox1, Cox2 and Cox3, conserved in the bacterial enzyme. Their biogenesis requires the action of messenger-specific and subunit-specific factors which facilitate the synthesis, membrane insertion, maturation or assembly of the core subunits. The study of yeast strains and human cell lines from patients carrying mutations in structural subunits and COX assembly factors has been invaluable to identify these ancillary factors. Here we review the current state of knowledge of the biogenesis and assembly of the eukaryotic COX catalytic core and discuss the degree of conservation of the players and mechanisms operating from yeast to human.

Soto, Ileana C.; Fontanesi, Flavia; Liu, Jingjing; Barrientos, Antoni

2011-01-01

277

Flood vent access door assembly  

US Patent & Trademark Office Database

A flood vent access door assembly having a frame assembly defining a fluid entrance aperture; a door pivotally mounted in said frame assembly, where in the door includes at least one ventilation opening formed through the door; and at least one latching/release mechanism for releasably maintaining the door in a fixed position relative to the frame assembly if a level of fluid is not above a determined level and releasing the door to pivot relative to the frame assembly if the level of fluid is above the determined level, wherein the at least one latching/release mechanism comprises a float means coupled to an elongate release arm for determining the level of fluid and releasing a latch of the at least one latching/release mechanism.

Hurst; Steven L. (Moon, VA); Higdon; William R. (Moon, VA)

2011-04-19

278

Advanced gray rod control assembly  

DOEpatents

An advanced gray rod control assembly (GRCA) for a nuclear reactor. The GRCA provides controlled insertion of gray rod assemblies into the reactor, thereby controlling the rate of power produced by the reactor and providing reactivity control at full power. Each gray rod assembly includes an elongated tubular member, a primary neutron-absorber disposed within the tubular member said neutron-absorber comprising an absorber material, preferably tungsten, having a 2200 m/s neutron absorption microscopic capture cross-section of from 10 to 30 barns. An internal support tube can be positioned between the primary absorber and the tubular member as a secondary absorber to enhance neutron absorption, absorber depletion, assembly weight, and assembly heat transfer characteristics.

Drudy, Keith J; Carlson, William R; Conner, Michael E; Goldenfield, Mark; Hone, Michael J; Long, Jr., Carroll J; Parkinson, Jerod; Pomirleanu, Radu O

2013-09-17

279

Restructuring the Common School in Ohio: The Path to Educational Progress. Policy and Budget Recommendations of the State Board of Education to the Governor and 119th General Assembly.  

ERIC Educational Resources Information Center

When the Ohio State Board of Education began developing legislative recommendations for the 1992-93 biennium, the state's economic outlook was more positive. However, conditions changed dramatically and the state faced a budget deficit. While recognizing these economic limitations, the board proposed that the education system must move toward…

Ohio State Dept. of Education, Columbus.

280

De novo assembly of highly diverse viral populations  

PubMed Central

Background Extensive genetic diversity in viral populations within infected hosts and the divergence of variants from existing reference genomes impede the analysis of deep viral sequencing data. A de novo population consensus assembly is valuable both as a single linear representation of the population and as a backbone on which intra-host variants can be accurately mapped. The availability of consensus assemblies and robustly mapped variants are crucial to the genetic study of viral disease progression, transmission dynamics, and viral evolution. Existing de novo assembly techniques fail to robustly assemble ultra-deep sequence data from genetically heterogeneous populations such as viruses into full-length genomes due to the presence of extensive genetic variability, contaminants, and variable sequence coverage. Results We present VICUNA, a de novo assembly algorithm suitable for generating consensus assemblies from genetically heterogeneous populations. We demonstrate its effectiveness on Dengue, Human Immunodeficiency and West Nile viral populations, representing a range of intra-host diversity. Compared to state-of-the-art assemblers designed for haploid or diploid systems, VICUNA recovers full-length consensus and captures insertion/deletion polymorphisms in diverse samples. Final assemblies maintain a high base calling accuracy. VICUNA program is publicly available at: http://www.broadinstitute.org/scientific-community/science/projects/viral-genomics/ viral-genomics-analysis-software. Conclusions We developed VICUNA, a publicly available software tool, that enables consensus assembly of ultra-deep sequence derived from diverse viral populations. While VICUNA was developed for the analysis of viral populations, its application to other heterogeneous sequence data sets such as metagenomic or tumor cell population samples may prove beneficial in these fields of research.

2012-01-01

281

Operations Considerations in Space Station Freedom Assembly.  

National Technical Information Service (NTIS)

The importance of planning the on-orbit operations inherent in the Space Station Freedom assembly sequence is discussed. Any solution to the assembly puzzle requires the simultaneous satisfaction of many diverse constraints, including: on-orbit assembly o...

S. C. Doering W. G. Bastedo

1989-01-01

282

49 CFR 195.130 - Fabricated assemblies.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Fabricated assemblies. 195.130 Section 195.130 Transportation...Design Requirements § 195.130 Fabricated assemblies. Each fabricated assembly to be installed in a pipeline system must...

2012-10-01

283

49 CFR 195.130 - Fabricated assemblies.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Fabricated assemblies. 195.130 Section 195.130 Transportation...Design Requirements § 195.130 Fabricated assemblies. Each fabricated assembly to be installed in a pipeline system must...

2011-10-01

284

D0 Silicon Upgrade: Ladder Assembly Sequences.  

National Technical Information Service (NTIS)

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 ...

P. Ratzmann

1994-01-01

285

Eyecup Assembly for a Submarine Periscope.  

National Technical Information Service (NTIS)

An eyecup assembly for a submarine periscope blinder assembly includes an annularly-shaped ring having a multiplicity of holes, which are unthreaded, extending therethrough and adapted to receive screws for securing the eyecup assembly to a like multiplic...

W. C. Macieiewski R. Sayegh

2000-01-01

286

ASSEMBLY TRANSFER SYSTEM DESCRIPTION DOCUMENT  

SciTech Connect

The Assembly Transfer System (ATS) receives, cools, and opens rail and truck transportation casks from the Carrier/Cask Handling System (CCHS). The system unloads transportation casks consisting of bare Spent Nuclear Fuel (SNF) assemblies, single element canisters, and Dual Purpose Canisters (DPCs). For casks containing DPCs, the system opens the DPCs and unloads the SNF. The system stages the assemblies, transfer assemblies to and from fuel-blending inventory pools, loads them into Disposal Containers (DCs), temporarily seals and inerts the DC, decontaminates the DC and transfers it to the Disposal Container Handling System. The system also prepares empty casks and DPCs for off-site shipment. Two identical Assembly Transfer System lines are provided in the Waste Handling Building (WHB). Each line operates independently to handle the waste transfer throughput and to support maintenance operations. Each system line primarily consists of wet and dry handling areas. The wet handling area includes a cask transport system, cask and DPC preparation system, and a wet assembly handling system. The basket transport system forms the transition between the wet and dry handling areas. The dry handling area includes the dry assembly handling system, assembly drying system, DC preparation system, and DC transport system. Both the wet and dry handling areas are controlled by the control and tracking system. The system operating sequence begins with moving transportation casks to the cask preparation area. The cask preparation operations consist of cask cavity gas sampling, cask venting, cask cool-down, outer lid removal, and inner shield plug lifting fixture attachment. Casks containing bare SNF (no DPC) are filled with water and placed in the cask unloading pool. The inner shield plugs are removed underwater. For casks containing a DPC, the cask lid(s) is removed, and the DPC is penetrated, sampled, vented, and cooled. A DPC lifting fixture is attached and the cask is placed into the cask unloading pool. In the cask unloading pool the DPC is removed from the cask and placed in an overpack and the DPC lid is severed and removed. Assemblies are removed from either an open cask or DPC and loaded into assembly baskets positioned in the basket staging rack in the assembly unloading pool. A method called ''blending'' is utilized to load DCs with a heat output of less than 11.8 kW. This involves combining hotter and cooler assemblies from different baskets. Blending requires storing some of the hotter fuel assemblies in fuel-blending inventory pools until cooler assemblies are available. The assembly baskets are then transferred from the basket staging rack to the assembly handling cell and loaded into the assembly drying vessels. After drying, the assemblies are removed from the assembly drying vessels and loaded into a DC positioned below the DC load port. After installation of a DC inner lid and temporary sealing device, the DC is transferred to the DC decontamination cell where the top area of the DC, the DC lifting collar, and the DC inner lid and temporary sealing device are decontaminated, and the DC is evacuated and backfilled with inert gas to prevent prolonged clad exposure to air. The DC is then transferred to the Disposal Container Handling System for lid welding. In another cask preparation and decontamination area, lids are replaced on the empty transportation casks and DPC overpacks, the casks and DPC overpacks are decontaminated, inspected, and transferred to the Carrier/Cask Handling System for shipment off-site. All system equipment is designed to facilitate manual or remote operation, decontamination, and maintenance. The system interfaces with the Carrier/Cask Handling System for incoming and outgoing transportation casks and DPCs. The system also interfaces with the Disposal Container Handling System, which prepares the DC for loading and subsequently seals the loaded DC. The system support interfaces are the Waste Handling Building System and other internal WHB support systems.

B. Gorpani

2000-06-26

287

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

Code of Federal Regulations, 2013 CFR

...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,...

2013-04-01

288

Combinatorial optimization problems in self-assembly  

Microsoft Academic Search

Self-assembly is the ubiquitous process by which simple objects autonomously assemble into intricate complexes. It has been suggested that intricate self-assembly processes will ultimately be used in circuit fabrication, nano-robotics, DNA computation, and amorphous computing. In this paper, we study two combinatorial optimization problems related to efficient self-assembly of shapes in the Tile Assembly Model of self-assembly proposed by Rothemund

Leonard M. Adleman; Qi Cheng; Ashish Goel; Ming-Deh A. Huang; David Kempe; Pablo Moisset de Espanés; Paul Wilhelm Karl Rothemund

2002-01-01

289

Two-handed assembly sequencing  

SciTech Connect

This article considers the computational complexity of automatically determining assembly sequences for mechanical products. Specifically, we address the partitioning problem: given an assembly of rigid parts, identify a proper subassembly that can be removed as a rigid object without disturbing the rest of the assembly. We examine the complexity of the partitioning problem under various types of relative motions allowed for the subassemblies. We show that when arbitrary motions are allowed to separate the two subassemblies, partitioning is NP-complete. We then describe a general framework for reasoning about assembly motions called the interference diagram. In its most general form the interference diagram yields an exponential-time algorithm to partition an assembly. However, two special cases of the interference diagram studied in this article yield polynomial-time sequencing algorithms. The first case occurs when assembly motions are restricted to single translations. The second case considers infinitesimal rigid motions in translation and rotation and yields a superset of all feasible partitionings. These two algorithms have important practical applications in assembly planning. 33 refs., 14 figs.

Wilson, R.H. [Sandia National Lab., Albuquerque, NM (United States); Kavraki, L.; Latombe, J.C. [Stanford Univ., CA (United States); Perez, T.L. [Massachusetts Inst. of Technology, Cambridge, MA (United States)

1995-08-01

290

Force-assembly with friction  

SciTech Connect

Previously, force-assembly has been defined as an assembly process for which a single admittance control law (i.e., a single nominal velocity in conjunction with a single mapping of forces to motions) can guarantee the proper assembly of a given pair of mating parts. As a testbed application of force-assembly, the insertion of a workpiece into a fixture consisting of multiple rigid fixture elements (fixels) is addressed. Previous work in this area has shown that, when workpiece/fixture contact is frictionless and positional error is infinitesimal, there always exists an admittance control law that will ensure the proper insertion of a workpiece into a deterministic fixture. When workpiece/fixture contact is frictionless, the workpiece/fixture contact force contains the relative positional information required to identify error-reducing motions. Friction between the workpiece and fixture, however, provides a disturbance to the geometrical information contained in the contact force. This paper addresses: (1) the identification of the conditions that must be satisfied for force-assembly with friction, and (2) the formulation and results of an optimization of the admittance control law to obtain the maximum value of friction that will satisfy the force-assembly conditions for a given workpiece/fixture combination. Results indicate that force-assembly fails when the contact forces are no longer characteristic. Forces are characteristic if the possible contact forces that may occur for one type of misalignment are unique to that type of misalignment.

Schimmels, J.M. (Marquette Univ., Milwaukee, WI (United States)); Peshkin, M.A. (Northwestern Univ., Evanston, IL (United States). Dept. of Mechanical Engineering)

1994-08-01

291

Dissolver vessel bottom assembly  

DOEpatents

An improved bottom assembly is provided for a nuclear reactor fuel reprocessing dissolver vessel wherein fuel elements are dissolved as the initial step in recovering fissile material from spent fuel rods. A shock-absorbing crash plate with a convex upper surface is disposed at the bottom of the dissolver vessel so as to provide an annular space between the crash plate and the dissolver vessel wall. A sparging ring is disposed within the annular space to enable a fluid discharged from the sparging ring to agitate the solids which deposit on the bottom of the dissolver vessel and accumulate in the annular space. An inlet tangential to the annular space permits a fluid pumped into the annular space through the inlet to flush these solids from the dissolver vessel through tangential outlets oppositely facing the inlet. The sparging ring is protected against damage from the impact of fuel elements being charged to the dissolver vessel by making the crash plate of such a diameter that the width of the annular space between the crash plate and the vessel wall is less than the diameter of the fuel elements.

Kilian, Douglas C. (Kennewick, WA)

1976-01-01

292

Flexible Foot Test Assembly  

SciTech Connect

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.

Kurita, C.H.; /Fermilab

1987-04-27

293

Lean staged combustion assembly  

SciTech Connect

This patent describes a lean staged combustion assembly. It comprises: means for channeling compressed air including a pilot portion and a main portion. This patent also describes an annular combustor outer liner having an upstream end and a downstream end; an annular combustor inner liner having an upstream end and a downstream end and spaced from the outer liner; means for obtaining pilot stage combustion of a fuel-air pilot mixture for generating pilot stage combustion gases between the inner and outer liners using the pilot portion of compressed air channeled to the combustor by the channeling means, a pilot combustor first liner having an upstream end and a downstream end and spaced from the outer liner to define a first pilot combustion zone; a pilot combustor second liner having an upstream end and a downstream end and spaced from the inner liner to define a second pilot combustion zone; circumferentially spaced first fuel injectors and corresponding first air swirlers extending between the first and outer liners at the upstream ends thereof; and circumferentially spaced second fuel injectors and corresponding second air swirlers extending between the second and inner liners at the upstream ends thereof.

Sabla, P.E.; Dodds, W.J.; Tucker, T.M.

1992-03-31

294

Downhole riser assembly  

SciTech Connect

A downhole riser assembly includes a tubular casing embedded in the ocean floor, said casing having a constant internal diameter and an upper end extending above said ocean floor. A tubular riser pipe is disposed in the casing and has an upper end connected to a floating vessel which may be a tension leg platform. The casing and riser are rigidly connected at a considerable distance below the ocean floor, said distance being on the order of 100 feet. When the floating structure is laterally displaced from a position directly above the casing, the riser pipe contacts the upper end of the casing. This contact limits the lateral deflection of the riser at the ocean floor and thereby limits the stresses in the riser. The distance between the upper end of the casing and the downhole connection between the casing and the riser, and the diameter of the casing are such that the riser has a rotational stiffness, adjacent the upper end of the casing, within a range such that both a maximum design maximum stress and a maximum design bottom slope of said riser are not exceeded when said riser is subjected to maximum design loading conditions. An alternative embodiment of the present invention provides a lateral support means for connecting the riser and the casing adjacent the upper end of the casing for restricting lateral movement of the riser.

Dareing, D.W.

1980-12-23

295

Subsea wellhead assembly  

SciTech Connect

A subsea wellhead assembly for areas subject to iceberg scouring including an upper conductor in a well bore and a lower conductor in the well bore with the upper end of the lower conductor being within the lower end of the upper conductor and connected thereto by a weak connection and the upper end of the lower conductor being below the maximum iceberg scour depth and means for connecting said conductors, said connecting means having sufficient strength to withstand bending loads during drilling and being removable for installation of production equipment. Additionally production equipment in the well bore includes a block valve supported within the second conductor and a production string extending upward from the block valve and having a weak point within the upper end of the second conductor whereby the well control is not lost by deep iceberg scouring since the production control equipment is within the second conductor which is not damaged by the scouring and the production equipment extending thereabove fails without damage to the lower control equipment or loss of the well.

Kelly, T. P.

1984-12-11

296

Concentric tube support assembly  

SciTech Connect

An assembly (45) includes a plurality of separate pie-shaped segments (72) forming a disk (70) around a central region (48) for retaining a plurality of tubes (46) in a concentrically spaced apart configuration. Each segment includes a support member (94) radially extending along an upstream face (96) of the segment and a plurality of annularly curved support arms (98) transversely attached to the support member and radially spaced apart from one another away from the central region for receiving respective upstream end portions of the tubes in arc-shaped spaces (100) between the arms. Each segment also includes a radial passageway (102) formed in the support member for receiving a fluid segment portion (106) and a plurality of annular passageways (104) formed in the support arms for receiving respective arm portions (108) of the fluid segment portion from the radial passageway and for conducting the respective arm portions into corresponding annular spaces (47) formed between the tubes retained by the disk.

Rubio, Mark F.; Glessner, John C.

2012-09-04

297

Exhaust gas recirculation valve assembly  

SciTech Connect

This paper describes an exhaust gas recirculation valve assembly. It comprises: a base having an exhaust gas chamber through which exhaust gas passes; a pintle valve assembly having a valve member disposed within the exhaust gas chamber and a valve stem extending outwardly of the chamber through an opening therein; an actuator, maintained in a fixed relationship to the base, coupling means, extending between the valve stem and the armature and configured to allow lateral movement of the valve stem relative to the armature to compensate for misalignment of the actuator relative to the base thereby preventing the misalignment from affecting the reciprocal operation of the pintle valve assembly relative to the base.

Grey, T.J.; Braun, C.N.; Palmer, D.O.

1991-06-04

298

Cooling assembly for fuel cells  

DOEpatents

A cooling assembly for fuel cells having a simplified construction whereby coolant is efficiently circulated through a conduit arranged in serpentine fashion in a channel within a member of such assembly. The channel is adapted to cradle a flexible, chemically inert, conformable conduit capable of manipulation into a variety of cooling patterns without crimping or otherwise restricting of coolant flow. The conduit, when assembled with the member, conforms into intimate contact with the member for good thermal conductivity. The conduit is non-corrodible and can be constructed as a single, manifold-free, continuous coolant passage means having only one inlet and one outlet.

Kaufman, Arthur (West Orange, NJ); Werth, John (Princeton, NJ)

1990-01-01

299

Mitotic spindle assembly by two different pathways in vitro  

PubMed Central

We have used Xenopus egg extracts to study spindle morphogenesis in a cell-free system and have identified two pathways of spindle assembly in vitro using methods of fluorescent analogue cytochemistry. When demembranated sperm nuclei are added to egg extracts arrested in a mitotic state, individual nuclei direct the assembly of polarized microtubule arrays, which we term half-spindles; half-spindles then fuse pairwise to form bipolar spindles. In contrast, when sperm nuclei are added to extracts that are induced to enter interphase and arrested in the following mitosis, a single sperm nucleus can direct the assembly of a complete spindle. We find that microtubule arrays in vitro are strongly biased towards chromatin, but this does not depend on specific kinetochore-microtubule interactions. Indeed, although we have identified morphological and probably functional kinetochores in spindles assembled in vitro, kinetochores appear not to play an obligate role in the establishment of stable, bipolar microtubule arrays in either assembly pathway. Features of the two pathways suggest that spindle assembly involves a hierarchy of selective microtubule stabilization, involving both chromatin-microtubule interactions and antiparallel microtubule-microtubule interactions, and that fundamental molecular interactions are probably the same in both pathways. This in vitro reconstitution system should be useful for identifying the molecules regulating the generation of asymmetric microtubule arrays and for understanding spindle morphogenesis in general.

1991-01-01

300

Nuclear fuel assembly holddown apparatus  

SciTech Connect

A fuel assembly has a lower end fitting and a spidered actuating rod interacting therewith for holding the assembly down on the core support stand against the upward flow of coolant. Locking means and bracing means for interacting with projections on the support stand are carried by the lower end fitting and are actuated by the movement of the actuating rod operated from above the top of the assembly. The locking means include weak springs mounted near some but not all of the end fitting posts, for engaging the support stand. Stiff springs are mounted internal to the other posts, for holding the posts against adjacent support stand projections to provide a bracing for the locking means as the spider portion of the actuating rod presses against the locking spring. The angle and spring rate per unit length of the bracing spring are preset to assure a fairly constant locking force during the life of the assembly.

Anthony, A.J.; Martin, K.A.

1982-01-05

301

Automated Solar Panel Assembly Line.  

National Technical Information Service (NTIS)

The initial stage of the automated solar panel assembly line program was devoted to concept development and proof of approach through simple experimental verification. In this phase, laboratory bench models were built to demonstrate and verify concepts. F...

H. Somberg

1981-01-01

302

General Purpose Modular Waveguide Assembly.  

National Technical Information Service (NTIS)

The article describes the design of a general purpose modular waveguide assembly consisting of orthogonally intersecting transmission lines coupled by two ferrite resonators. The construction allows one design version to serve as a directional bandpass fi...

A. V. Kislyakovskii N. G. Vodopyanov S. N. Kushch

1972-01-01

303

Adaptive, Pneumatic Gripper for Assembly.  

National Technical Information Service (NTIS)

The construction of an adaptive, pneumatic gripper is presented. The gripper can be used in the precision assembly of cylindrical parts of different sizes (20 - 40 mm) into holes. The adaptive gripper can compensate for robot positioning errors during ass...

R. Soudunsaari V. Gradetskij V. Veshnikov A. Abarinov

1988-01-01

304

Submarine Periscope Eyeguard Housing Assembly.  

National Technical Information Service (NTIS)

A submarine periscope eyeguard housing assembly includes a viewing lens housing having a viewing lens aperture and viewing lens therein, first and second arm members fixed to the viewing lens housing and extending therefrom, a first blinder mounted on the...

W. C. Maciejewski R. Sayegh

2001-01-01

305

Directed Assembly of Biological Polymers  

Microsoft Academic Search

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

Aline Miller

2009-01-01

306

Self-Assembled Circuit Patterns  

Microsoft Academic Search

Self-assembly is a process in which basic units aggregate un- der attractive forces to form larger compound structures. Recent theo- retical work has shown that pseudo-crystalline self-assembly can be al- gorithmic, in the sense that complex logic can be programmed into the growth process (26). This theoretical work builds on the theory of two- dimensional tilings (8), using rigid square

Matthew Cook; Paul W. K. Rothemund; Erik Winfree

2003-01-01

307

Wafer scale micromachine assembly method  

DOEpatents

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.

Christenson, Todd R. (Albuquerque, NM)

2001-01-01

308

Fuel cell design and assembly  

SciTech Connect

The present invention is directed to a novel bipolar cooling plate, fuel cell design and method of assembly of fuel cells. The bipolar cooling plate used in the fuel cell design and method of assembly has discrete opposite edge and means carried by the plate defining a plurality of channels extending along the surface of the plate toward the opposite edges. At least one edge of the channels terminates short of the edge of the plate defining a recess for receiving a fastener.

Meyerhoff, A.

1982-07-01

309

Performance of International Space Station electric power system during station assembly  

Microsoft Academic Search

The International Space Station (ISS) will be an Earth-orbiting laboratory in space. It will house experimental payloads, distribute resource utilities, and support human habitation for conducting research and science experiments in a microgravity environment. The ISS will be assembled on-orbit through 44 assembly and utilization flights using the launch vehicles of the United States, Russian Republic and the European Space

L. M. Hague; K. J. Metcalf; G. M. Shannon; R. C. Hill; Cheng-Yi Lu

1996-01-01

310

Computer simulation of natural convection heat transfer from an assembly of vertical cylinders of PARR2  

Microsoft Academic Search

In this paper a Computer Code COSINAC (Computer Simulation of Natural Convection from Assembly of vertical Cylinders) has been developed to simulate the natural convection heat transfer from an assembly of vertical cylinders of Pakistan Research Reactor-2 (PARR-2), under the steady state reactor operation. The momentum and energy equations in cylindrical co-ordinates, representing the thermal hydraulic behavior of a typical

M. Abdul Basit; Muhammad Rafique; Imran R. Chughtai; Mansoor H. Inayat

2007-01-01

311

Poolside examination of gadolinia lead test assemblies after two cycles of irradiation  

Microsoft Academic Search

The Babcock and Wilcox Company, Duke Power Company, and the United States Department of Energy are participating in an extended burnup project involving the irradiation and examination of an advanced fuel assembly design for pressurized water reactors. This advanced fuel assembly includes rods containing a UOâ-GdâOâ fuel and burnable absorber mixture along with other design features that enhance fuel perforemance

L. W. Newman; P. L. Holman; J. T. Mayer; T. P. Papazoglou; T. D. Pyecha; P. C. Aadland

1987-01-01

312

Photoluminescence of an assembly of size-distributed self-assembled InAs quantum dots  

NASA Astrophysics Data System (ADS)

We have performed experimental and theoretical studies of the effects of inhomogeneous broadening on the luminescence properties of a self-assembled InAs quantum dot (QD) assembly. From atomic force microscopic (AFM) images the InAs QD assembly is found to have an average lateral size of 20-22 nm and a height of 10-12 nm, and the dot density is in the range of 1-2 x1010 cm-2. Using the statistical distribution of the QD size from AFM measurements and the results from the theoretical analysis of the photoluminescene (PL) spectrum, it is found that the distance between QDs is larger than 30 nm (the average distance is about 100 nm), the penetration of the ground-state wave function into the GaAs barrier is negligible, and the calculated PL spectrum agrees well with that measured when the carriers in each QD are assumed to be at a local thermal equilibrium state, resulting in the conclusion that the QDs are physically independent. The width of the PL peak is determined by the inhomogeneous QD size.

Fu, Y.; Ferdos, F.; Sadeghi, M.; Wang, S. M.; Larsson, A.

2002-09-01

313

Tools and methods for automated assembly of miniaturized gear systems  

NASA Astrophysics Data System (ADS)

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.

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

2000-10-01

314

Reference-assisted chromosome assembly  

PubMed Central

One of the most difficult problems in modern genomics is the assembly of full-length chromosomes using next generation sequencing (NGS) data. To address this problem, we developed “reference-assisted chromosome assembly” (RACA), an algorithm to reliably order and orient sequence scaffolds generated by NGS and assemblers into longer chromosomal fragments using comparative genome information and paired-end reads. Evaluation of results using simulated and real genome assemblies indicates that our approach can substantially improve genomes generated by a wide variety of de novo assemblers if a good reference assembly of a closely related species and outgroup genomes are available. We used RACA to reconstruct 60 Tibetan antelope (Pantholops hodgsonii) chromosome fragments from 1,434 SOAPdenovo sequence scaffolds, of which 16 chromosome fragments were homologous to complete cattle chromosomes. Experimental validation by PCR showed that predictions made by RACA are highly accurate. Our results indicate that RACA will significantly facilitate the study of chromosome evolution and genome rearrangements for the large number of genomes being sequenced by NGS that do not have a genetic or physical map.

Kim, Jaebum; Larkin, Denis M.; Cai, Qingle; Asan; Zhang, Yongfen; Ge, Ri-Li; Auvil, Loretta; Capitanu, Boris; Zhang, Guojie; Lewin, Harris A.; Ma, Jian

2013-01-01

315

The Atlas Genome Assembly System  

PubMed Central

Atlas is a suite of programs developed for assembly of genomes by a “combined approach” that uses DNA sequence reads from both BACs and whole-genome shotgun (WGS) libraries. The BAC clones afford advantages of localized assembly with reduced computational load, and provide a robust method for dealing with repeated sequences. Inclusion of WGS sequences facilitates use of different clone insert sizes and reduces data production costs. A core function of Atlas software is recruitment of WGS sequences into appropriate BACs based on sequence overlaps. Because construction of consensus sequences is from local assembly of these reads, only small (<0.1%) units of the genome are assembled at a time. Once assembled, each BAC is used to derive a genomic layout. This “sequence-based” growth of the genome map has greater precision than with non-sequence-based methods. Use of BACs allows correction of artifacts due to repeats at each stage of the process. This is aided by ancillary data such as BAC fingerprint, other genomic maps, and syntenic relations with other genomes. Atlas was used to assemble a draft DNA sequence of the rat genome; its major components including overlapper and split-scaffold are also being used in pure WGS projects.

Havlak, Paul; Chen, Rui; Durbin, K. James; Egan, Amy; Ren, Yanru; Song, Xing-Zhi; Weinstock, George M.; Gibbs, Richard A.

2004-01-01

316

62. SUPPORT CARRIAGE ASSEMBLY AT BASE OF VAL LAUNCHING SLAB ...  

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

62. SUPPORT CARRIAGE ASSEMBLY AT BASE OF VAL LAUNCHING SLAB AFTER TRANSFER FROM BARGE IN FOREGROUND, February, 11, 1948. (Original photograph in possession of Dave Willis, San Diego, California.) - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

317

56. ASSEMBLY OF THE VAL BRIDGE STRUCTURE AT ISLIP CANYON, ...  

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

56. ASSEMBLY OF THE VAL BRIDGE STRUCTURE AT ISLIP CANYON, July 31, 1947. (Original photograph in possession of Dave Willis, San Diego, California.) - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

318

61. SIDE VIEW OF SUPPORT CARRIAGE ASSEMBLY WITH VAL BRIDGE ...  

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

61. SIDE VIEW OF SUPPORT CARRIAGE ASSEMBLY WITH VAL BRIDGE STRUCTURE IN BACKGROUND AT ISLIP CANYON, Date unknown, circa February 1948. (Original photograph in possession of Dave Willis, San Diego, California.) - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

319

Preferences of the American Assembly of Collegiate Schools of Business  

Microsoft Academic Search

Business school interest in accreditation by the American Assembly of Collegiate Schools of Business (AACSB) has been increasing because of declining enrollment coupled with expanded competition. This article analyzes data for nearly all United States graduate business programs and finds that accreditation status differences for 9 out of 10 schools can be explained by differences in measurable factors such as

Robert H. Jantzen; Thomas A. Pendleton

1994-01-01

320

Snubber assembly for a control rod drive  

Microsoft Academic Search

A snubber cartridge assembly is mounted to the nozzle of a control rod drive mechanism to insure that the snubber assembly will be located within the liquid filled section of a nuclear reactor vessel whenever the control rod drive is assembled thereto. The snubber assembly includes a piston mounted proximate to the control rod connecting end of the control rod

1978-01-01

321

Randomized Self-assembly for Approximate Shapes  

Microsoft Academic Search

In this paper we design tile self-assembly systems which assemble arbitrarily close approximations to target squares with arbitrarily high probability. This is in contrast to previous work which has only considered deterministic assemblies of a single shape. Our technique takes advantage of the ability to assign tile concentrations to each tile type of a self-assembly system. Such an assignment yields

Ming-yang Kao; Robert T. Schweller

2008-01-01

322

Simplified generation of all mechanical assembly sequences  

Microsoft Academic Search

Bourjault has presented a method which will generate all valid assembly sequences for the set of parts that constitute an assembly. A modification of Bourjault's method is presented which makes practical the application of this technique of assembly analysis to assemblies with greatly increased part count. The salient difference between the two methods is in the form and number of

T. De Fazio; D. E. Whitney

1987-01-01

323

A Model for Capturing Product Assembly Information  

Microsoft Academic Search

The important issue of mechanical assemblies has been a subject of intense research over the past several years. Most electromechanical products are assemblies of several components, for various technical as well as economic reasons. This paper provides an object-oriented definition of an assembly model called the Open Assembly Model (OAM) and defines an extension to the NIST Core Product Model

Sudarsan Rachuri; Young-Hyun Han; Sebti Foufou; Shaw C. Feng; Utpal Roy; Fujun Wang; Ram D. Sriram; Kevin W. Lyons

2006-01-01

324

FASTENER FOR AN ASSEMBLY OF PLATES  

DOEpatents

A fastener is provided for a spaced-apart parallel plate fuel assembly. The fastener, attached by screws to a key that passes through the edges of the assembled plate, serves as a retainer for the outermost plate as well as a bidirectional spacer for separating the fuel assembly from two neighboring fuel assemblies. (AEC)

Groh, E.F.

1963-08-20

325

Printed wiring assembly and interconnection reliability  

NASA Astrophysics Data System (ADS)

This report presents reliability prediction models for printed wiring assemblies, solderless wrap assemblies, wrapped and soldered assemblies, and discrete wiring assemblies w/electroless deposited PTH for inclusion in MIL-HDBK-217. Collected field failure rate data were utilized to develop and evaluate the factors. The reliability prediction models are presented in a form compatible with MIL-HDBK-217D.

Coit, D. W.

1981-11-01

326

Printed wiring assembly and interconnection reliability  

Microsoft Academic Search

This report presents reliability prediction models for printed wiring assemblies, solderless wrap assemblies, wrapped and soldered assemblies, and discrete wiring assemblies w\\/electroless deposited PTH for inclusion in MIL-HDBK-217. Collected field failure rate data were utilized to develop and evaluate the factors. The reliability prediction models are presented in a form compatible with MIL-HDBK-217D.

D. W. Coit

1981-01-01

327

Maintaining geometric dependencies in an assembly planner  

Microsoft Academic Search

The problem of generating assembly sequences strictly from the geometry of a goal assembly is addressed. The planner considers 2-D, polygonal parts and makes the usual assumptions about the monotony of partial assemblies, which allows an `and\\/or' graph representation to be used. The problem of decreasing the number of geometric checks which must be done to test candidate assembly operations

Randall H. Wilson; Jean-Fransois Rit

1990-01-01

328

Small angle x-ray scattering studies of mitochondrial glutaminase C reveal extended flexible regions, and link oligomeric state with enzyme activity.  

PubMed

Glutaminase C is a key metabolic enzyme, which is unregulated in many cancer systems and believed to play a central role in the Warburg effect, whereby cancer cells undergo changes to an altered metabolic profile. A long-standing hypothesis links enzymatic activity to the protein oligomeric state, hence the study of the solution behavior in general and the oligomer state in particular of glutaminase C is important for the understanding of the mechanism of protein activation and inhibition. In this report, this is extensively investigated in correlation to enzyme concentration or phosphate level, using a high-throughput microfluidic-mixing chip for the SAXS data collection, and we confirm that the oligomeric state correlates with activity. The in-depth solution behavior analysis further reveals the structural behavior of flexible regions of the protein in the dimeric, tetrameric and octameric state and investigates the C-terminal influence on the enzyme solution behavior. Our data enable SAXS-based rigid body modeling of the full-length tetramer states, thereby presenting the first ever experimentally derived structural model of mitochondrial glutaminase C including the N- and C-termini of the enzyme. PMID:24098668

Møller, Magda; Nielsen, Søren S; Ramachandran, Sekar; Li, Yuxing; Tria, Giancarlo; Streicher, Werner; Petoukhov, Maxim V; Cerione, Richard A; Gillilan, Richard E; Vestergaard, Bente

2013-09-30

329

Small Angle X-Ray Scattering Studies of Mitochondrial Glutaminase C Reveal Extended Flexible Regions, and Link Oligomeric State with Enzyme Activity  

PubMed Central

Glutaminase C is a key metabolic enzyme, which is unregulated in many cancer systems and believed to play a central role in the Warburg effect, whereby cancer cells undergo changes to an altered metabolic profile. A long-standing hypothesis links enzymatic activity to the protein oligomeric state, hence the study of the solution behavior in general and the oligomer state in particular of glutaminase C is important for the understanding of the mechanism of protein activation and inhibition. In this report, this is extensively investigated in correlation to enzyme concentration or phosphate level, using a high-throughput microfluidic-mixing chip for the SAXS data collection, and we confirm that the oligomeric state correlates with activity. The in-depth solution behavior analysis further reveals the structural behavior of flexible regions of the protein in the dimeric, tetrameric and octameric state and investigates the C-terminal influence on the enzyme solution behavior. Our data enable SAXS-based rigid body modeling of the full-length tetramer states, thereby presenting the first ever experimentally derived structural model of mitochondrial glutaminase C including the N- and C-termini of the enzyme.

M?ller, Magda; Nielsen, S?ren S.; Ramachandran, Sekar; Li, Yuxing; Tria, Giancarlo; Streicher, Werner; Petoukhov, Maxim V.; Cerione, Richard A.; Gillilan, Richard E.; Vestergaard, Bente

2013-01-01

330

TOOL ASSEMBLY WITH BI-DIRECTIONAL BEARING  

DOEpatents

A two-direction motion bearing which is incorporated in a refueling nuclear fuel element trsnsfer tool assembly is described. A plurality of bi- directional bearing assembliesare fixed equi-distantly about the circumference of the transfer tool assembly to provide the tool assembly with a bearing surface- for both axial and rotational motion. Each bi-directional bearing assembly contains a plurality of circumferentially bulged rollers mounted in a unique arrangement which will provide a bearing surface for rotational movement of the tool assembly within a bore. The bi-direc tional bearing assembly itself is capable of rational motion and thus provides for longitudinal movement of the tool assembly.

Longhurst, G.E.

1961-07-11

331

Electric field mediated colloidal assembly and control  

NASA Astrophysics Data System (ADS)

This dissertation presents video microscopy measurements and computer simulations of colloidal particle interactions in inhomogeneous, high-frequency AC electric fields. The interactions of particles with each other and inhomogeneous electric fields are quantified as a function of concentration, field amplitude, and frequency. Visual state diagrams show that these interactions in concentrated systems produce quasi-two dimensional microstructures including confined hard disk fluids, oriented dipolar chains, and oriented hexagonal close packed crystals. The interaction of a particle interacting with an electric field is directly measured with analyses of a single diffusing colloid within electric fields in the absence of many body effects. Concentrated systems are characterized in terms of density profiles across the electrode gap and angular pair distribution functions. An inverse Monte Carlo analysis extracted the induced dipole-induced dipole interaction from concentrated measurements. A single adjustable parameter consistently modified the induced dipole-field potential and the induced dipole-induced dipole potential to account for modification of the local electric field as the result of the local particle concentration, frequency and configuration. Confocal laser scanning microscopy (CLSM) perform sensitive measurements of internal three dimensional structure of crystals assembled in an interfacial quadrupole electrode device. Radial distributions as functions of elevation are used to characterize the equilibrium structure. A single adjustable parameter modified known potentials to match Monte Carlo simulations with experiment. The local density from experiment and simulation matched the expected density calculated from a balance of osmotic pressure and dielectrophoretic compression. Simulations qualitatively matched experimental observations of microstructure as a function of field amplitude. Programmable assembly for colloidal crystals is implemented in the quadrupole electrode device by guiding the dynamic evolution of a colloidal ensemble. A feedback method is used to control electric field mediated assembly based on real-time sensing and actuation single and multiple electrokinetic mechanisms. Sensing is achieved using particle tracking and order parameter computation to quantify the degree of order during the assembly process. A geometrical parameter for hexagonal close packing and radius of gyration are investigated as order parameters for quantifying condensation and crystallization. Colloidal crystal assembly and disassembly is actuated using electroosmosis and negative and positive dielectrophoresis (i.e. dipole-field interactions).

Juarez, Jaime Javier

332

The higher excited electronic states and spin orbit splitting of the valence band in three-dimensional assemblies of close-packed ZnSe and CdSe quantum dots in thin film form  

NASA Astrophysics Data System (ADS)

Optical properties of as-deposited and annealed thin films composed of three-dimensional arrays of sphalerite-type ZnSe and CdSe quantum dots (QDs), synthesized by chemical deposition, were investigated. Neglecting the S D mixing of hole states, the lowest “band to band” transitions in very small nanoclusters and in bulk-like clusters may be assigned as 1S?1S and 1S??1S, and are split by spin orbit (SO) splitting energy of the bulk material—?. The splitting energy between these transitions was found to be insensitive to QD size variations, which could be explained assuming that 1S hole states arising from valence band ?7 and ?8 components do not mix with higher angular momentum states and shift together to higher energies coupled via the isotropic hole mass. This implies significant difference between the SO splitting energies in the two semiconductors. Accounting for S D mixing of hole states, the observed transitions may be attributed to the fundamental ground state—(1S3/2, 1Se) and the ground state—(1S1/2, 1Se) ones. The observed “splittings” thus do not correspond exactly to SO splitting energy in both semiconductors, but are complex functions of it, as exact position of each hole energy level depends, besides on ?, also on other material-characteristic parameters.

Pejova, Biljana

2008-08-01

333

Nanoparticle Assemblies via Self-Assembling Peptide Molecules  

NASA Astrophysics Data System (ADS)

The bottom up approach towards nano-scale patterning presents the possibility of creating hierarchical architectures through simple self-assembly strategies. Herein, we elucidate the self-assembly of different types of peptide molecules into unique nano-scale morphologies and demonstrate their application in the construction of linear arrays of inorganic nanoparticles. A 20 amino acid peptide, consisting of alternating hydrophilic (lysine) and hydrophobic (valine) residues flanking a central diproline turn sequence (VKVKVKVKVPPTKVKVKVKV-NH2) was employed as a nano-scale template for the organization of 2nm gold particles. This peptide self assembles into a laminated morphology in solution and has a periodic nanostructure consisting of alternating hydrophobic and hydrophilic layers with a lateral periodicity of 2.5 nm. Negatively charged gold nanoparticles are templated into the positively charged lysine layer through electrostatic interaction and are aligned within the template to form laterally spaced (2D) linear arrays. Also, a long chain alanine-rich polypeptide was used to create 1D nanoparticle assemblies. This peptide assembles into fibrils with monodisperse widths and presents its charged functional groups periodically along the length of the fibril. These functional groups bind nanoparticles that results in their spatially modulated linear arrangement.

Sharma, Nikhil; Lamm, Matthew; Schneider, Joel; Kiick, Kristi; Pochan, Darrin

2009-03-01

334

LDRD final report: Automated planning and programming of assembly of fully 3D mechanisms  

SciTech Connect

This report describes the results of assembly planning research under the LDRD. The assembly planning problem is that of finding a sequence of assembly operations, starting from individual parts, that will result in complete assembly of a device specified as a CAD model. The automated assembly programming problem is that of automatically producing a robot program that will carry out a given assembly sequence. Given solutions to both of these problems, it is possible to automatically program a robot to assemble a mechanical device given as a CAD data file. This report describes the current state of our solutions to both of these problems, and a software system called Archimedes 2 we have constructed to automate these solutions. Because Archimedes 2 can input CAD data in several standard formats, we have been able to test it on a number of industrial assembly models more complex than any before attempted by automated assembly planning systems, some having over 100 parts. A complete path from a CAD model to an automatically generated robot program for assembling the device represented by the CAD model has also been demonstrated.

Kaufman, S.G.; Wilson, R.H.; Jones, R.E.; Calton, T.L.; Ames, A.L.

1996-11-01

335

Agents, assemblers, and ANTS: scheduling assembly with market and biological software mechanisms  

Microsoft Academic Search

Nanoscale assemblers will need robust, scalable, flexible, and well-understood mechanisms such as software agents to control them. This paper discusses assemblers and agents, and proposes a taxonomy of their possible interaction. Molecular assembly is seen as a special case of general assembly, subject to many of the same issues, such as the advantages of convergent assembly, and the problem of

Tihamer T. Toth-Fejel

2000-01-01

336

Triangular Tile Self-assembly Systems  

Microsoft Academic Search

\\u000a We discuss theoretical aspects of the self-assembly of triangular tiles; in particular, right triangular tiles and equilateral\\u000a triangular tiles. Contrary to intuition, we show that triangular tile assembly systems and square tile assembly systems are\\u000a not comparable in general. More precisely, there exists a square tile assembly system S such that no triangular tile assembly system that is a division

Lila Kari; Shinnosuke Seki; Zhi Xu

2010-01-01

337

The Tile Complexity of Linear Assemblies  

Microsoft Academic Search

Self-assembly is fundamental to both biological processes and nanoscience. Key features of self-assembly are its probabilistic nature and local programmability. These features can be leveraged to design better self-assembled systems. The conventional Tile Assembly Model (TAM) developed by Winfree using Wang tiles is a powerful, Turing-universal theoretical framework which models varied self-assembly processes. A particular challenge in DNA nanoscience is

Harish Chandran; Nikhil Gopalkrishnan; John H. Reif

2009-01-01

338

Transducers with Programmable Input by DNA Self-assembly  

Microsoft Academic Search

\\u000a Notions of Wang tiles, finite state machines and recursive functions are tied together. We show that there is a natural way\\u000a to simulate finite state machines with output (transducers) with Wang tiles and we show that recursive (computable) functions\\u000a can be obtained as composition of transducers through employing Wang tiles. We also show how a programmable transducer can\\u000a be self-assembled

Natasa Jonoska; Shiping Liao; Nadrian C. Seeman

2004-01-01

339

The higher excited electronic states and spin-orbit splitting of the valence band in three-dimensional assemblies of close-packed ZnSe and CdSe quantum dots in thin film form  

SciTech Connect

Optical properties of as-deposited and annealed thin films composed of three-dimensional arrays of sphalerite-type ZnSe and CdSe quantum dots (QDs), synthesized by chemical deposition, were investigated. Neglecting the S-D mixing of hole states, the lowest 'band to band' transitions in very small nanoclusters and in bulk-like clusters may be assigned as 1S{yields}1S and 1S{sub {delta}}{yields}1S, and are split by spin-orbit (SO) splitting energy of the bulk material-{delta}. The splitting energy between these transitions was found to be insensitive to QD size variations, which could be explained assuming that 1S hole states arising from valence band {gamma}{sub 7} and {gamma}{sub 8} components do not mix with higher angular momentum states and shift together to higher energies coupled via the isotropic hole mass. This implies significant difference between the SO splitting energies in the two semiconductors. Accounting for S-D mixing of hole states, the observed transitions may be attributed to the fundamental ground state-(1S{sub 3/2}, 1S{sub e}) and the ground state-(1S{sub 1/2}, 1S{sub e}) ones. The observed 'splittings' thus do not correspond exactly to SO splitting energy in both semiconductors, but are complex functions of it, as exact position of each hole energy level depends, besides on {delta}, also on other material-characteristic parameters. - Graphical abstract: Accounting for S-D mixing of hole states, the observed optical transitions in very small sphalerite-type ZnSe and CdSe nanoclusters are attributed to the ground state-(1S{sub 3/2}, 1S{sub e}) and the ground state-(1S{sub 1/2}, 1S{sub e}). The 'splittings' do not correspond to SO splitting energy, but are complex functions of it.

Pejova, Biljana [Faculty of Natural Sciences and Mathematics, Institute of Chemistry, Saints Cyril and Methodius University, PO Box 162, 1001 Skopje (Macedonia, The Former Yugoslav Republic of)], E-mail: biljana@iunona.pmf.ukim.edu.mk

2008-08-15

340

Designing Isotropic Interactions for Self-Assembly of Complex Lattices  

NASA Astrophysics Data System (ADS)

We present a direct method for solving the inverse problem of designing isotropic potentials that cause self-assembly into target lattices. Each potential is constructed by matching its energy spectrum to the reciprocal representation of the lattice to guarantee that the desired structure is a ground state. We use the method to self-assemble complex lattices not previously achieved with isotropic potentials, such as a snub square tiling and the kagome lattice. The latter is especially interesting because it provides the crucial geometric frustration in several proposed spin liquids.

Edlund, E.; Lindgren, O.; Jacobi, M. Nilsson

2011-08-01

341

Benchmark assemblies of the Los Alamos Critical Assemblies Facility  

SciTech Connect

Several critical assemblies of precisely known materials composition and easily calculated and reproducible geometries have been constructed at the Los Alamos National Laboratory. Some of these machines, notably Jezebel, Flattop, Big Ten, and Godiva, have been used as benchmark assemblies for the comparison of the results of experimental measurements and computation of certain nuclear reaction parameters. These experiments are used to validate both the input nuclear data and the computational methods. The machines and the applications of these machines for integral nuclear data checks are described.

Dowdy, E.J.

1985-01-01

342

iAssembler: a package for de novo assembly of Roche-454/Sanger transcriptome sequences  

PubMed Central

Background Expressed Sequence Tags (ESTs) have played significant roles in gene discovery and gene functional analysis, especially for non-model organisms. For organisms with no full genome sequences available, ESTs are normally assembled into longer consensus sequences for further downstream analysis. However current de novo EST assembly programs often generate large number of assembly errors that will negatively affect the downstream analysis. In order to generate more accurate consensus sequences from ESTs, tools are needed to reduce or eliminate errors from de novo assemblies. Results We present iAssembler, a pipeline that can assemble large-scale ESTs into consensus sequences with significantly higher accuracy than current existing assemblers. iAssembler employs MIRA and CAP3 assemblers to generate initial assemblies, followed by identifying and correcting two common types of transcriptome assembly errors: 1) ESTs from different transcripts (mainly alternatively spliced transcripts or paralogs) are incorrectly assembled into same contigs; and 2) ESTs from same transcripts fail to be assembled together. iAssembler can be used to assemble ESTs generated using the traditional Sanger method and/or the Roche-454 massive parallel pyrosequencing technology. Conclusion We compared performances of iAssembler and several other de novo EST assembly programs using both Roche-454 and Sanger EST datasets. It demonstrated that iAssembler generated significantly more accurate consensus sequences than other assembly programs.

2011-01-01

343

The elegans of spindle assembly  

PubMed Central

The Caenorhabditis elegans one-cell embryo is a powerful system in which to study microtubule organization because this large cell assembles both meiotic and mitotic spindles within the same cytoplasm over the course of 1 h in a stereotypical manner. The fertilized oocyte assembles two consecutive acentrosomal meiotic spindles that function to reduce the replicated maternal diploid set of chromosomes to a single-copy haploid set. The resulting maternal DNA then unites with the paternal DNA to form a zygotic diploid complement, around which a centrosome-based mitotic spindle forms. The early C. elegans embryo is amenable to live-cell imaging and electron tomography, permitting a detailed structural comparison of the meiotic and mitotic modes of spindle assembly.

Greenan, Garrett; O'Toole, Eileen

2010-01-01

344

Encapsulation of methane and other small molecules in a self-assembling superstructure  

SciTech Connect

Physical inclusion of small molecules in larger structural lattices is well known in the crystalline state and is a common feature of the chemistry of zeolites. In the liquid state, a variety of synthetic macrocyclic molecules are available to complex and contain smaller guest species. An alternative strategy for binding is explored: assembly of cavity-forming structures from smaller subunits. Encapsulation of small guest molecules such as methane can be achieved with a synthetic structure that assemblies reversibly through hydrogen bonding.

Branda, N.; Wyler, R.; Rebek, J. Jr. (Massachusetts Institute of Technology, Cambridge, MA (United States))

1994-03-04

345

The Archimedes 2 mechanical assembly planning system  

SciTech Connect

We describe the implementation and performance of Archimedes 2, an integrated mechanical assembly planning system. Archimedes 2 includes two planners, two assembly sequence animation facilities, and an associated robotic workcell. Both planners use full 3 dimensional data. A rudimentary translator from high level assembly plans to control code for the robotic workcell has also been implemented. We can translate data from a commercial CAD system into input data for the system, which has allowed us to plan assembly sequences for many industrial assemblies. Archimedes 2 has been used to plan sequences for assemblies consisting of 5 to 109 parts. We have also successfully taken a CAD model of an assembly, produced an optimized assembly sequence for it, and translated the plan into robot code, which successfully assembles the device specified in the model.

Kaufman, S.G.; Wilson, R.H.; Jones, R.E.; Calton, T.L.; Ames, A.L.

1996-03-01

346

Sensor Assembly, System Including RFID Sensor Assemblies, and Method.  

National Technical Information Service (NTIS)

A system comprises of a valve, a plurality of RFID sensor assemblies coupled to the valve to monitor a plurality of parameters associated with the valve; a control tag configured to wirelessly communicate with the respective tags that are coupled to the v...

J. R. Skorpik S. R. Gosselin J. C. Harris

2003-01-01

347

Assembly of Gas-Turbine Aircraft Engines (Selected Chapters).  

National Technical Information Service (NTIS)

While the units and subassemblies can be assembled both in an assembly shop and in the assembly sections of the combined and machine-assembly shops, the overall assembly of an engine is done only in an assembly shop. The overall assembly of engines, just ...

D. E. Smirnov L. K. Nikolenko T. A. Dushina V. I. Sokolov

1970-01-01

348

Biogenesis and assembly of eukaryotic cytochrome c oxidase catalytic core.  

PubMed

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 which assembly is intricate and highly regulated. The COX catalytic core is formed by three mitochondrial DNA encoded subunits, Cox1, Cox2 and Cox3, conserved in the bacterial enzyme. Their biogenesis requires the action of messenger-specific and subunit-specific factors which facilitate the synthesis, membrane insertion, maturation or assembly of the core subunits. The study of yeast strains and human cell lines from patients carrying mutations in structural subunits and COX assembly factors has been invaluable to identify these ancillary factors. Here we review the current state of knowledge of the biogenesis and assembly of the eukaryotic COX catalytic core and discuss the degree of conservation of the players and mechanisms operating from yeast to human. This article is part of a Special Issue entitled: Biogenesis/Assembly of Respiratory Enzyme Complexes. PMID:21958598

Soto, Ileana C; Fontanesi, Flavia; Liu, Jingjing; Barrientos, Antoni

2011-09-16

349

The higher excited electronic states and spin–orbit splitting of the valence band in three-dimensional assemblies of close-packed ZnSe and CdSe quantum dots in thin film form  

Microsoft Academic Search

Optical properties of as-deposited and annealed thin films composed of three-dimensional arrays of sphalerite-type ZnSe and CdSe quantum dots (QDs), synthesized by chemical deposition, were investigated. Neglecting the S–D mixing of hole states, the lowest “band to band” transitions in very small nanoclusters and in bulk-like clusters may be assigned as 1S?1S and 1S??1S, and are split by spin–orbit (SO)

Biljana Pejova; Biljana

2008-01-01

350

Channel selective tunnelling through a nanographene assembly  

NASA Astrophysics Data System (ADS)

We report selective tunnelling through a nanographene intermolecular tunnel junction achieved via scanning tunnelling microscope tip functionalization with hexa-peri-hexabenzocoronene (HBC) molecules. This leads to an offset in the alignment between the energy levels of the tip and the molecular assembly, resulting in the imaging of a variety of distinct charge density patterns in the HBC assembly, not attainable using a bare metallic tip. Different tunnelling channels can be selected by the application of an electric field in the tunnelling junction, which changes the condition of the HBC on the tip. Density functional theory-based calculations relate the imaged HBC patterns to the calculated molecular orbitals at certain energy levels. These patterns bear a close resemblance to the ?-orbital states of the HBC molecule calculated at the relevant energy levels, mainly below the Fermi energy of HBC. This correlation demonstrates the ability of an HBC functionalized tip as regards accessing an energy range that is restricted to the usual operating bias range around the Fermi energy with a normal metallic tip at room temperature. Apart from relating to molecular orbitals, some patterns could also be described in association with the Clar aromatic sextet formula. Our observations may help pave the way towards the possibility of controlling charge transport between organic interfaces.

Wong, H. S.; Feng, X.; Müllen, K.; Chandrasekhar, N.; Durkan, C.

2012-03-01

351

Channel selective tunnelling through a nanographene assembly.  

PubMed

We report selective tunnelling through a nanographene intermolecular tunnel junction achieved via scanning tunnelling microscope tip functionalization with hexa-peri-hexabenzocoronene (HBC) molecules. This leads to an offset in the alignment between the energy levels of the tip and the molecular assembly, resulting in the imaging of a variety of distinct charge density patterns in the HBC assembly, not attainable using a bare metallic tip. Different tunnelling channels can be selected by the application of an electric field in the tunnelling junction, which changes the condition of the HBC on the tip. Density functional theory-based calculations relate the imaged HBC patterns to the calculated molecular orbitals at certain energy levels. These patterns bear a close resemblance to the ?-orbital states of the HBC molecule calculated at the relevant energy levels, mainly below the Fermi energy of HBC. This correlation demonstrates the ability of an HBC functionalized tip as regards accessing an energy range that is restricted to the usual operating bias range around the Fermi energy with a normal metallic tip at room temperature. Apart from relating to molecular orbitals, some patterns could also be described in association with the Clar aromatic sextet formula. Our observations may help pave the way towards the possibility of controlling charge transport between organic interfaces. PMID:22322294

Wong, H S; Feng, X; Müllen, K; Chandrasekhar, N; Durkan, C

2012-02-10

352

Development of Hybrid Assembly Workplaces  

Microsoft Academic Search

In times of shortened innovation cycles, increasing product variation and demands for faster delivery, the flexibility of production systems is crucial for success. Hybrid workplaces, dynamically configurable for both human workers and robots, help to increase the flexibility. The robot kinematics employed, the available sensors, and the grasping conditions involved in the assembly process mainly determine the changeover effort of

S. Consiglio; G. Seliger; N. Weinert

2007-01-01

353

Proactive Instructions for Furniture Assembly  

Microsoft Academic Search

Tennenhouse (1) coined the term proactive computing where humans get out of the interaction loop and may be serviced specically according to their needs and current situation. In this paper we propose a framework for proactive assembly instructions which aims to overcome limitations of today's printed and computer based instructions. By at- taching several computing devices and multiple sensors onto

Stavros Antifakos; Florian Michahelles; Bernt Schiele

2002-01-01

354

Submersible Motor-Pump Assembly.  

National Technical Information Service (NTIS)

The patent describes a submersible motor-pump assembly including: a reservoir casing which is adapted to contain a hydraulic fluid; a hydraulic pump mounted within the casing, the pump having an inlet which is located within the casing and an outlet which...

A. T. Strickland

1973-01-01

355

Corner-cutting mining assembly  

SciTech Connect

A mining assembly includes a primary rotary cutter mounted on one end of a support shaft and four secondary rotary cutters carried on the same support shaft and positioned behind the primary cutter for cutting corners in the hole cut by the latter.

Bradley, J.A.

1983-08-23

356

CALUTRON ASSEMBLING AND DISASSEMBLING MEANS  

Microsoft Academic Search

This patent relates to the assembling and disassembling of a calutron ; and, more specifically describes a calutron having the ion separating mechanism ; carried by a fuce plate removably secured to the tank. When it is desired to ; withdraw the ion separating mechanism from the tank, a motor is energized and a ; carriage attached through a bracket

R. E. Andrews; J. Thornton

1959-01-01

357

X-48B Prototype Assembly  

NASA Video Gallery

A timelapse video from 2006 of the assembly of the X-48B prototype wind tunnel model at NASA's Langley Research Center in Hampton, Va.Learn more about the X-48 blended wing body wind-tunnel and flight tests at http://www.nasa.gov/topics/aeronautics/features/bwb_main.html.

Robert Allen

2011-08-12

358

Valve Stem and Packing Assembly.  

National Technical Information Service (NTIS)

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 mean...

J. J. Wordin

1990-01-01

359

Valve stem and packing assembly.  

National Technical Information Service (NTIS)

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 mean...

J. J. Wordin

1990-01-01

360

Simulated nuclear reactor fuel assembly  

DOEpatents

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.

Berta, Victor T. (Idaho Falls, ID)

1993-01-01

361

Muscle assembly: a titanic achievement?  

Microsoft Academic Search

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

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

1999-01-01

362

A Bill of Rights Assembly.  

ERIC Educational Resources Information Center

|Presents a student- and community-produced assembly program in which several Supreme Court cases are reenacted. Focuses on student rights concerning search and seizure, freedom of speech, and freedom of of the press. Provides a 40- to 50-minute script with roles for narrators, administrators, police officers, reporters, lawyers, and students.…

Kenny, Maureen; Reilley, Margaret

1991-01-01

363

Assembly of quasicrystalline photonic heterostructures  

DOEpatents

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.

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

2013-03-12

364

Assembly of quasicrystalline photonic heterostructures  

DOEpatents

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.

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

365

Hot hollow cathode gun assembly  

DOEpatents

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.

Zeren, J.D.

1983-11-22

366

MITRAC links mitochondrial protein translocation to respiratory-chain assembly and translational regulation.  

PubMed

Mitochondrial respiratory-chain complexes assemble from subunits of dual genetic origin assisted by specialized assembly factors. Whereas core subunits are translated on mitochondrial ribosomes, others are imported after cytosolic translation. How imported subunits are ushered to assembly intermediates containing mitochondria-encoded subunits is unresolved. Here, we report a comprehensive dissection of early cytochrome c oxidase assembly intermediates containing proteins required for normal mitochondrial translation and reveal assembly factors promoting biogenesis of human respiratory-chain complexes. We find that TIM21, a subunit of the inner-membrane presequence translocase, is also present in the major assembly intermediates containing newly mitochondria-synthesized and imported respiratory-chain subunits, which we term MITRAC complexes. Human TIM21 is dispensable for protein import but required for integration of early-assembling, presequence-containing subunits into respiratory-chain intermediates. We establish an unexpected molecular link between the TIM23 transport machinery and assembly of respiratory-chain complexes that regulate mitochondrial protein synthesis in response to their assembly state. PMID:23260140

Mick, David U; Dennerlein, Sven; Wiese, Heike; Reinhold, Robert; Pacheu-Grau, David; Lorenzi, Isotta; Sasarman, Florin; Weraarpachai, Woranontee; Shoubridge, Eric A; Warscheid, Bettina; Rehling, Peter

2012-12-21

367

Nuclear mass inventory, photon dose rate and thermal decay heat of spent research reactor fuel assemblies  

SciTech Connect

This document has been prepared to assist research reactor operators possessing spent fuel containing enriched uranium of United States origin to prepare part of the documentation necessary to ship this fuel to the United States. Data are included on the nuclear mass inventory, photon dose rate, and thermal decay heat of spent research reactor fuel assemblies. Isotopic masses of U, Np, Pu and Am that are present in spent research reactor fuel are estimated for MTR, TRIGA and DIDO-type fuel assembly types. The isotopic masses of each fuel assembly type are given as functions of U-235 burnup in the spent fuel, and of initial U-235 enrichment and U-235 mass in the fuel assembly. Photon dose rates of spent MTR, TRIGA and DIDO-type fuel assemblies are estimated for fuel assemblies with up to 80% U-235 burnup and specific power densities between 0.089 and 2.857 MW/kg[sup 235]U, and for fission product decay times of up to 20 years. Thermal decay heat loads are estimated for spent fuel based upon the fuel assembly irradiation history (average assembly power vs. elapsed time) and the spent fuel cooling time.

Pond, R.B.; Matos, J.E.

1996-12-31

368

Solar cooker and method of assembly  

SciTech Connect

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.

Kerr, B.P.

1980-12-02

369

Solar cooker and method of assembly  

Microsoft Academic Search

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.

Kerr

1980-01-01

370

Marine Corps Diver's Backpack/Battery Assembly.  

National Technical Information Service (NTIS)

A diver's backpack/battery assembly was developed for the Naval Medical Research Institute for eventual Marine Corps use in shallow water diving. The assembly was a modified MK VIII underwater breathing apparatus backpack with a 28-volt Silvercel battery ...

D. Taylor J. J. Bayles

1969-01-01

371

President Mandela Address to Constitutional Assembly  

NSDL National Science Digital Library

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.

Mandela, Nelson, 1918-.

1996-01-01

372

Exploiting sparseness in de novo genome assembly  

PubMed Central

Background The very large memory requirements for the construction of assembly graphs for de novo genome assembly limit current algorithms to super-computing environments. Methods In this paper, we demonstrate that constructing a sparse assembly graph which stores only a small fraction of the observed k-mers as nodes and the links between these nodes allows the de novo assembly of even moderately-sized genomes (~500 M) on a typical laptop computer. Results We implement this sparse graph concept in a proof-of-principle software package, SparseAssembler, utilizing a new sparse k-mer graph structure evolved from the de Bruijn graph. We test our SparseAssembler with both simulated and real data, achieving ~90% memory savings and retaining high assembly accuracy, without sacrificing speed in comparison to existing de novo assemblers.

2012-01-01

373

Automated Integrated Circuit Processing and Assembly.  

National Technical Information Service (NTIS)

The report describes the results of a study on automated procedures for integrated circuit (IC) processing and assembly by the semiconductor industry. Emphasis is on automated IC production, especially processing of wafers and assembly of chips into devic...

H. G. Rudenberg

1975-01-01

374

Wire Assembly for Electrically Conductive Circuits.  

National Technical Information Service (NTIS)

A wire assembly for electrically conductive circuits, the assembly comprising a circuit conductor wire having a coating of insulative material thereon, a shielding foil wrapped at least partially around the coating and having a leg portion extending outwa...

W. T. Schneider

1992-01-01

375

Reactivity control assembly for nuclear reactor. [LMFBR  

DOEpatents

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.

Bollinger, L.R.

1982-03-17

376

Pedestrian Detection by Probabilistic Component Assembly  

NASA Astrophysics Data System (ADS)

We present a novel pedestrian detection system based on probabilistic component assembly. A part-based model is proposed which uses three parts consisting of head-shoulder, torso and legs of a pedestrian. Components are detected using histograms of oriented gradients and Support Vector Machines (SVM). Optimal features are selected from a large feature pool by boosting techniques, in order to calculate a compact representation suitable for SVM. A Bayesian approach is used for the component grouping, consisting of an appearance model and a spatial model. The probabilistic grouping integrates the results, scale and position of the components. To distinguish both classes, pedestrian and non-pedestrian, a spatial model is trained for each class. Below miss rates of 8% our approach outperforms state of the art detectors. Above, performance is similar.

Rapus, Martin; Munder, Stefan; Baratoff, Gregory; Denzler, Joachim

377

Multiexciton Spectroscopy of a Single Self-Assembled Quantum Dot  

NASA Astrophysics Data System (ADS)

We apply low temperature confocal optical microscopy to spatially resolve, and spectroscopically study, a single self-assembled quantum dot. By comparing the emission spectra obtained at various excitation levels to a theoretical many body model, we show that (a) single exciton radiative recombination is very weak, and (b) sharp spectral lines are due to optical transitions between confined multiexcitonic states among which excitons thermalize within their lifetimes. Once these few states are fully occupied, broadbands appear due to transitions between states which contain electrons in the continuum.

Dekel, E.; Gershoni, D.; Ehrenfreund, E.; Spektor, D.; Garcia, J. M.; Petroff, P. M.

1998-06-01

378

Toward minimum size self-assembled counters  

Microsoft Academic Search

DNA self-assembly is a promising paradigm for nanotechnology. In this paper we study the problem of finding tile systems of\\u000a minimum size that assemble a given shape in the Tile Assembly Model, defined by Rothemund and Winfree (Proceedings of the\\u000a thirty-second annual ACM symposium on theory of computing, 2000). We present a tile system that assembles an $$N\\\\times\\\\lceil\\\\log_2 N\\\\rceil$$ rectangle

Pablo Moisset De Espanés; Ashish Goel

2008-01-01

379

Magnetic scanning of LWR fuel assemblies  

SciTech Connect

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.

Fiarman, S.; Moodenbaugh, A.

1980-01-01

380

19 CFR 10.16 - Assembly abroad.  

Code of Federal Regulations, 2013 CFR

...solid components is not regarded as an assembly. Example 1. A television yoke is assembled abroad from American-made magnet wire. In the foreign assembly plant the wire is despooled and wound into a coil, the wire cut from the spool, and...

2013-04-01

381

FCA Assembly V-1 Critical Experiment.  

National Technical Information Service (NTIS)

The FCA assembly V-1 attained its first criticality on February 27th, 1970. The assembly V-1 is the first physics mock-up in series assemblies for which mock-up experiments for the JOYO (Japan Experimental Fast Reactor) are planned. Composition of the cor...

N. Hirakawa T. Mukaiyama K. Shirakata S. Nomoto J. Hirota

1978-01-01

382

Anchoring structure for marine riser assembly  

Microsoft Academic Search

This patent describes an anchor system for anchoring the lower end of a marine riser, lower marine riser package (LMRP) assembly and drill string to the ocean floor, it comprises: an anchor assembly secured to the ocean floor, the assembly including a tubular member extending into the ocean bottom; a guide means, an elongated weight means disposed in the tubular

Ritter; P. B. Jr

1992-01-01

383

Anchoring structure for marine riser assembly  

SciTech Connect

This patent describes an anchor system for anchoring the lower end of a marine riser, lower marine riser package (LMRP) assembly and drill string to the ocean floor, it comprises: an anchor assembly secured to the ocean floor, the assembly including a tubular member extending into the ocean bottom; a guide means, an elongated weight means disposed in the tubular member.

Ritter, P.B. Jr.

1992-09-15

384

Reduced Radar Cross Section Exhaust Nozzle Assembly.  

National Technical Information Service (NTIS)

An exhaust nozzle assembly includes a plurality of interfitting flap assemblies that are moveable between a maximum area ratio and a minimum area ratio. Each of the pluralities of flap assemblies includes a slot and a wing. The wing fits within an adjacen...

J. Allore J. A. Arbona M. Harris S. Laporte

2005-01-01

385

Gas Cooled Fast Reactor Benchmark Critical Assembly.  

National Technical Information Service (NTIS)

The GCFR Phase I assembly is the initial Gas-Cooled Fast Reactor Benchmark assembly on the ZPR-9 reactor at Argonne National Laboratory. It represents the first full scale mockup of a GCFR ever assembled. It is a clean, simple geometry benchmark reference...

S. K. Bhattacharyya R. D. McKnight W. R. Robinson E. M. Bohn G. K. Rusch

1975-01-01

386

Gas cooled fast reactor benchmark critical assembly  

Microsoft Academic Search

The GCFR Phase I assembly is the initial Gas-Cooled Fast Reactor ; Benchmark assembly on the ZPR-9 reactor at Argonne National Laboratory. It ; represents the first full scale mockup of a GCFR ever assembled. It is a clean, ; simple geometry benchmark reference for the 300 MW(e) GCFR Demonstration Plant ; designed by General Atomic Company. A description and

S. K. Bhattacharyya; R. D. McKnight; W. R. Robinson; E. M. Bohn; G. K. Rusch; F. H. Martens; L. G. LeSage

1975-01-01

387

Concurrent assembly planning with genetic algorithms  

Microsoft Academic Search

This work investigates the application of genetic algorithm (GA)-based search techniques to concurrent assembly planning, where product design and assembly process planning are performed in parallel, and the evaluation of a design configuration is influenced by the performance of its related assembly process. Several types of GAs and an exhaustive combinatorial approach are compared, in terms of reliability and speed

Nicola Senin; Roberto Groppetti; David R Wallace

2000-01-01

388

Analysis of assembly systems controlled with kanbans  

Microsoft Academic Search

This paper deals with the problem of evaluating the performance of assembly systems managed with kanbans. In particular we analyze kanban systems functioning with different control policies depending on how kanbans are released in assembly stages. Simultaneous and independent releases of kanbans are considered in the analysis as alternative control policies to be used in assembly systems. Queuing network techniques

Andrea Matta; Yves Dallery; Maria Di Mascolo

2005-01-01

389

Self-Assembly: How Nature Builds  

ERIC Educational Resources Information Center

|Self-assembly or spontaneous assembly is a process in which materials build themselves without assistance. This process plays a central role in the construction of biological structures and materials such as cells, viruses, and bone, and also in abiotic processes like phase transitions and crystal formation. The principles of self-assembly help…

Jones, M. Gail; Falvo, Michael R.; Broadwell, Bethany; Dotger, Sharon

2006-01-01

390

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

PubMed

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

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

2013-09-09

391

Assembly dynamics of two-beta sheets revealed by molecular dynamics simulations.  

PubMed

The assembly dynamics of two beta sheets with different initial separation distances are explored by multiple all-atom molecular dynamics simulations with the presence of explicit water solvent. The beta sheet is composed of seven identical peptides in an antiparallel fashion. The peptide sequence is the 20-29 segment of human Islet amyloid polypeptide. Our simulations show that the assembly occurs not only in the lateral direction but also along the longitudinal direction, which provides a new insight into the assembly pathway at the early stage of fibril elongation. Based on Poisson-Boltzmann free energy analysis and quasiharmonic configuration entropy estimation, the entropic contribution is found to play an important role in the longitudinal assembly. Moreover, a possible oligomeric state with cyclic form is suggested based on one assembly model found in the simulations, illustrating the polymorphic nature of aggregation of the amyloidogenic peptide. PMID:19405618

Xu, Weixin; Ping, Jiang; Li, Weifeng; Mu, Yuguang

2009-04-28

392

Dissection of Pilus Tip Assembly by the FimD Usher Monomer  

PubMed Central

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.

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

2013-01-01

393

Elongation in the major direction of tobacco mosaic virus assembly  

PubMed Central

Butler and Lomonossoff [Butler, P. J. G. & Lomonossoff, G. P. (1978) J. Mol. Biol. 126, 877-882] claim that the elongation in the major direction (3??5?) proceeds by incorporation of disk protein in tobacco mosaic virus (TMV) assembly. The strongest argument they have for this theory is the periodicity of 50 or 100 nucleotides that they observed in the banding pattern of the protected RNAs during the first few minutes of the assembly reaction. We repeated their experiment using TMV-OM (a common Japanese strain) disk protein and TMV-OM RNA. We observed a banding pattern similar to theirs, but we found the long protected RNA at 6 min to be from the 260-nm intermediate particle rather than from the full-length TMV RNA. We also carried out the assembly reaction between TMV-OM disk protein, as well as cucumber green mottle mosaic virus (CGMMV) protein, and three strains of TMV RNAs. During the course of each assembly reaction, we examined the banding patterns. We demonstrated that the banding pattern of the protected RNA differs depending on what kind of RNA is used, rather than on what kind of aggregational state the protein is in. Specifically, the similar banding pattern observed for CGMMV subunit protein was also observed for TMV disk protein in the assembly reaction with TMV (OM) RNA. We showed previously that the assembly reaction between CGMMV protein and TMV RNA proceeds by incorporation of CGMMV subunit protein. This strongly indicates that the banding pattern of the protected RNA does not arise from the stepwise addition of the 20S disk protein. Images

Fukuda, Megumi; Okada, Yoshimi

1985-01-01

394

Elongation in the major direction of tobacco mosaic virus assembly.  

PubMed

Butler and Lomonossoff [Butler, P. J. G. & Lomonossoff, G. P. (1978) J. Mol. Biol. 126, 877-882] claim that the elongation in the major direction (3'-->5') proceeds by incorporation of disk protein in tobacco mosaic virus (TMV) assembly. The strongest argument they have for this theory is the periodicity of 50 or 100 nucleotides that they observed in the banding pattern of the protected RNAs during the first few minutes of the assembly reaction. We repeated their experiment using TMV-OM (a common Japanese strain) disk protein and TMV-OM RNA. We observed a banding pattern similar to theirs, but we found the long protected RNA at 6 min to be from the 260-nm intermediate particle rather than from the full-length TMV RNA. We also carried out the assembly reaction between TMV-OM disk protein, as well as cucumber green mottle mosaic virus (CGMMV) protein, and three strains of TMV RNAs. During the course of each assembly reaction, we examined the banding patterns. We demonstrated that the banding pattern of the protected RNA differs depending on what kind of RNA is used, rather than on what kind of aggregational state the protein is in. Specifically, the similar banding pattern observed for CGMMV subunit protein was also observed for TMV disk protein in the assembly reaction with TMV (OM) RNA. We showed previously that the assembly reaction between CGMMV protein and TMV RNA proceeds by incorporation of CGMMV subunit protein. This strongly indicates that the banding pattern of the protected RNA does not arise from the stepwise addition of the 20S disk protein. PMID:16593565

Fukuda, M; Okada, Y

1985-06-01

395

Assembly of synthetic cellulose I.  

PubMed

Cellulose microfibrils with an electron diffraction pattern characteristic of crystalline native cellulose I have been assembled abiotically by means of a cellulase-catalyzed polymerization of beta-cellobiosyl fluoride substrate monomer in acetonitrile/acetate buffer. Substantial purification of the Trichoderma viride cellulase enzyme was found to be essential for the formation of the synthetic cellulose I allomorph. Assembly of synthetic cellulose I appears to be a result of a micellar aggregation of the partially purified enzyme and the substrate in an organic/aqueous solvent system favoring the alignment of glucan chains with the same polarity and extended chain conformation, resulting in crystallization to form the metastable cellulose I allomorph. PMID:7519776

Lee, J H; Brown, R M; Kuga, S; Shoda, S; Kobayashi, S

1994-08-01

396

Nuclear reactor composite fuel assembly  

DOEpatents

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.

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

1980-01-01

397

Reversibly assembled cellular composite materials.  

PubMed

We introduce composite materials made by reversibly assembling a three-dimensional lattice of mass-produced carbon fiber-reinforced polymer composite parts with integrated mechanical interlocking connections. The resulting cellular composite materials can respond as an elastic solid with an extremely large measured modulus for an ultralight material (12.3 megapascals at a density of 7.2 milligrams per cubic centimeter). These materials offer a hierarchical decomposition in modeling, with bulk properties that can be predicted from component measurements and deformation modes that can be determined by the placement of part types. Because site locations are locally constrained, structures can be produced in a relative assembly process that merges desirable features of fiber composites, cellular materials, and additive manufacturing. PMID:23950496

Cheung, Kenneth C; Gershenfeld, Neil

2013-08-15

398

BIOCHEMISTRY: An Enzyme Assembly Line  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. Fatty acid synthases and related megaenzymes are highly adaptable to new functions as a result of their modular architecture. The fundamental polymers of biology--proteins, DNA, and RNA--are products of repetitive condensation of simple amino acid or nucleotide building blocks and are comparatively easy to assemble. However, other biomolecules require additional reactions beyond condensation of building blocks. Examples are the fatty acids and the polyketide and nonribosomal peptide secondary metabolites. These molecules are produced by complex enzyme assembly lines that include multiple catalytic domains. Two new crystal structures--one reported recently (1), the other by Maier et al. on page 1315 of this issue (2)--enrich our understanding of how these mega-enzymes function as efficient factories to produce a remarkable range of metabolic products.

Janet L. Smith (University of Michigan;Life Sciences Institute; Department of Biological Chemistry); David H. Sherman (University of Michigan;Life Sciences Institute; Departments of Medicinal Chemistry, Chemistry, and Microbiology and Immunology)

2008-09-05

399

Closure assembly for a furnace  

SciTech Connect

A closure assembly for an access opening in a furnace wall is described; the assembly comprising: a door shell; means for pivoting the door shell to the furnace wall; at least one shoulder formed on the shell; a clip angle having one leg portion extending over a face of the shoulder; bolt means extending through the one leg portion and the shoulder for securing the clip angle to the shoulder; an anchor member secured to another leg portion of the clip angle; a plug member having a portion extending in the shell, a recessed portion for receiving the shoulder, and a portion adapted to extend in the access opening when the door is closed; at least one opening extending through the plug member for receiving the anchor member; a cup extending in the opening and adapted to receive a corresponding anchor member; and a castable material extending in the cup and over the anchor member to secure the plug member to the shell.

Barkley, J.D.

1989-01-10

400

Abrasive swivel assembly and method  

DOEpatents

An abrasive swivel assembly for providing a rotating, particle-laden fluid stream and, ultimately, a rotating particle-laden fluid jet is disclosed herein. This assembly includes a tubular arrangement for providing a particle-free stream of fluid, means for rotating a section of the tubular arrangement, and means for introducing solid particles into the particle-free fluid stream at a point along the rotating tubular section, whereby to produce a particle-laden fluid stream. This last-mentioned stream can then be used in combination with a cooperating nozzle arrangement for providing a rotating particle-laden fluid jet. In an actual working embodiment, the fluid stream is of sufficiently high pressure so that the abrasive jet can be used as a cutting jet.

Hashish, Mohamed (Kent, WA); Marvin, Mark (Tacoma, WA)

1989-01-01

401

Templating Surfaces with Gradient Assemblies  

Microsoft Academic Search

One of the most versatile and widely used methods of forming surfaces with position-dependent wettability is that conceived by Chaudhury and Whitesides more than a decade ago [Science256, 1539 (1992)]. In this paper we review several projects that utilize this gradient-forming methodology for: controlled of deposition of self-assembled monolayers on surfaces, generating arrays of nanoparticles with number density gradients, probing

Jan Genzer

2005-01-01

402

A self-assembled ionophore  

Microsoft Academic Search

Ionophores are compounds that bind and transport ions. Ion binding and transport are fundamental to many biological and chemical processes. In this thesis we detail the structural characterization and cation binding properties of a self-assembled ionophore built from an isoguanosine (isoG) derivative, 5sp'-t-butyldimethylsilyl-2sp',3sp'-isopropylidene isoG 30. We begin with a summary of the themes that facilitate ionophore design and the definitions

Sampath K. Tirumala

1997-01-01

403

Designing electron wave functions in assembled nanostructures  

NASA Astrophysics Data System (ADS)

We use the scanning tunneling microscope to not only to map electron wave functions but also to engineer them. By assembling nanostructures from individual atoms and molecules, we confine two-dimensional electronic states into closed electron resonators, or "quantum corrals". Precise control over the geometry of these structures allows electronic states to be tailored to suit particular experiments. Specifically, we design wave functions that enable studies of normally inaccessible quantum phases. First, we create pairs of quantum corrals with shapes drawn from contemporary mathematics. Exploiting special topological relationships between these structures, we retrieve internal quantum phase of electron wave functions without using interferometry. Second, we demonstrate that adding a single atom to a quantum corral can cause its electronic states to recombine into coherent superpositions. The real-space position of the additional atom controls abstract superposition phase angles, enabling arbitrary time-independent superpositions to be created. Third, we study geometric phase by creating a series of quantum corrals that traverse a closed path through a parameter space. Tracking the corral wave functions reveals a phase shift depending solely on the path taken, directly visualizing Berry's phase evolution in a quantum system. Finally, we extend beyond closed electron resonators and engineer wave functions in open nanostructures. We show that arbitrary patterns can be encoded into electronic states, creating a new form of holography on the nanoscale. We exhibit letters written in electron density rather than with atomic matter, and show that multiple letters may be simultaneously embedded at different energies in the same region of space. Because the wavelength of the electrons diminishes as energy is increased, this technique allows local information densities that exceed the conventionally assumed limit of 1 bit per atom. Taken together, the results in this thesis demonstrate unprecedented control of electron states in condensed matter and illuminate fundamental quantum phases that underlie systems ranging from coherent electronic devices to complex quantum materials.

Moon, Christopher Ryan

404

Automated solar module assembly line  

NASA Astrophysics Data System (ADS)

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.

Bycer, M.

1980-08-01

405

Self-assembled pyrazinacene nanotubes.  

PubMed

Nanotubes of a pentacene derivative, 6,13-bis(1-n-dodecyl)-[a,c,l,n]-tetrabenzo-5,6,7,12,13,14-hexaazapentacene, have been prepared by a hierarchical self-assembly mechanism. The oligoazaacenes 1-3, referred to as pyrazinacenes due to their structures of linearly fused pyrazine heterocycles, can also be considered as two azatriphenylenes fused through a reduced pyrazine ring. Dissolution of 6,13-bis(1-n-dodecyl)-[a,c,l,n]-tetrabenzo-5,6,7,12,13,14-hexaaza pentacene in nearly boiling toluene followed by standing of the solution at room temperature yields self-assembled (sa) pyrazinacene (Pa) nanotubes (NT's), or sa-PaNTs. Self-assembled-PaNTs are formed after initial aggregation of the pyrazinacene giving a 130-nm-wide 2-dimensional tape followed by helical twisting of this tape into a hollow cylindrical form of 150-200 nm diameter which can exceed 10 ?m in length. The morphologies of the tape and nanotube structures were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD) and electron absorption spectroscopy (UV/Vis). The latter indicates that the tubes may be formed by chromophore J-aggregation. Also, high resolution TEM of the tubes reveals that they can be composed of several tapes while powder X-ray diffraction revealed the lamellar structure of the tapes composing the tubes. PMID:21225075

Richards, Gary J; Hill, Jonathan P; Labuta, Jan; Wakayama, Yutaka; Akada, Misaho; Ariga, Katsuhiko

2011-01-12

406

Acoustically fabricated random microelectrode assemblies.  

PubMed

We report the insonation of bismuth, silver, copper and tungsten metal particles suspended in octane in the vicinity of a glassy carbon electrode. AFM and voltammetry reveal that metal particles are immobilised onto the electrode substrate. In the case of bismuth, silver and copper, the possible melting of the metal particles due to the high sonochemical conditions cannot unambiguously be ruled out. However, it is likely that the immobilisation of the metal particles occurs predominantly through mechanical attachment due to the high rates of mass transport, evidenced from the fact that tungsten can be immobilised at a glassy carbon surface which has a melting point (mp 3410 degrees C) outside the likely sonochemical conditions. The immobilised particles are found to be in electrical contact with the glassy carbon electrodes which can then act as random assemblies of microelectrodes. Proof-of-concept for use in electro-analysis is examined for the possible detection of arsenic and cadmium at a silver and bismuth random microelectrode assemblies, respectively. This approach suggests a simple generic methodology for the construction of microelectrode assemblies via abrasive attachment induced by insonation with power ultrasound. PMID:15932800

Ward-Jones, Sarah; Simm, Andrew O; Banks, Craig E; Compton, Richard G

2005-06-01

407

Haptic feedback for virtual assembly  

NASA Astrophysics Data System (ADS)

Assembly operations require high speed and precision with low cost. The manufacturing industry has recently turned attenuation to the possibility of investigating assembly procedures using graphical display of CAD parts. For these tasks, some sort of feedback to the person is invaluable in providing a real sense of interaction with virtual parts. This research develops the use of a commercial assembly robot as the haptic display in such tasks. For demonstration, a peg-hole insertion task is studied. Kane's Method is employed to derive the dynamics of the peg and the contact motions between the peg and the hole. A handle modeled as a cylindrical peg is attached to the end effector of a PUMA 560 robotic arm. The arm is handle modeled as a cylindrical peg is attached to the end effector of a PUMA 560 robotic arm. The arm is equipped with a six axis force/torque transducer. The use grabs the handle and the user-applied forces are recorded. A 300 MHz Pentium computer is used to simulate the dynamics of the virtual peg and its interactions as it is inserted in the virtual hole. The computed torque control is then employed to exert the full dynamics of the task to the user hand. Visual feedback is also incorporated to help the user in the process of inserting the peg into the hole. Experimental results are presented to show several contact configurations for this virtually simulated task.

Luecke, Greg R.; Zafer, Naci

1998-12-01

408

Rotor assembly and assay method  

DOEpatents

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.

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

1993-09-07

409

Multifunctional self-assembled monolayers  

SciTech Connect

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.

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

410

Rotor assembly and assay method  

DOEpatents

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.

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

1993-01-01

411

Automated assembly of VECSEL components  

NASA Astrophysics Data System (ADS)

Due to the architectural advantage of an external cavity architecture that enables the integration of additional elements into the cavity (e.g. for mode control, frequency conversion, wavelength tuning or passive mode-locking) VECSELs are a rapidly developing laser technology. Nevertheless they often have to compete with direct (edge) emitting laser diodes which can have significant cost advantages thanks to their rather simple structure and production processes. One way to compensate the economical disadvantages of VECSELs is to optimize each component in terms of quality and costs and to apply more efficient (batch) production processes. In this context, the paper presents recent process developments for the automated assembly of VECSELs using a new type of desktop assembly station with an ultra-precise micromanipulator. The core concept is to create a dedicated process development environment from which implemented processes can be transferred fluently to production equipment. By now two types of processes have been put into operation on the desktop assembly station: 1.) passive alignment of the pump optics implementing a camera-based alignment process, where the pump spot geometry and position on the semiconductor chip is analyzed and evaluated; 2.) active alignment of the end mirror based on output power measurements and optimization algorithms. In addition to the core concept and corresponding hardware and software developments, detailed results of both processes are presented explaining measurement setups as well as alignment strategies and results.

Brecher, C.; Pyschny, N.; Haag, S.; Mueller, T.

2013-02-01

412

Assembly modes of dragonfly wings.  

PubMed

The assembly modes of dragonfly wings are observed through FEG-ESEM. Different from airplane wings, dragonfly wings are found to be assembled through smooth transition mode and global package mode. First, at the vein/membrane conjunctive site, the membrane is divided into upper and lower portions from the center layer and transited smoothly to the vein. Then the two portions pack the vein around and form the outer surface of the vein. Second, at the vein/spike conjunctive site, the vein and spike are connected smoothly into a triplet. Last, at the vein/membrane/spike conjunctive site, the membrane (i.e., the outer layer of the vein) transits smoothly to the spike, packs it around, and forms its outer layer. In short, the membrane looks like a closed coat packing the wing as a whole. The smooth transition mode and the global package mode are universal assembly modes in dragonfly wings. They provide us the references for better understanding of the functions of dragonfly wings and the bionic manufactures of the wings of flights with mini sizes. PMID:21538699

Zhao, Hong-Xiao; Yin, Ya-Jun; Zhong, Zheng

2011-04-29

413

Thermal performance of a pin-fin assembly  

Microsoft Academic Search

The steady-state forced -convective cooling of a horizontally based pin-fin assembly has been investigated experimentally. The circular pin-fins protruded vertically upward from a horizontal base plate. For each in-line or staggered combination of specified pin-fins and air-flow rate, the optimal spacing-to-diameter ratios corresponding to the maximum rate of heat dissipation from the array have been deduced. The effect of changing

R. F. Babus'Haq; K. Akintunde; S. D. Probert

1995-01-01

414

Thermal performance of a pin-fin assembly  

Microsoft Academic Search

The steady-state forced-convective cooling of a horizontally based pin-fin assembly has been investigated experimentally. The circular pin-fins protruded vertically upward from a horizontal base plate. For each in-line or staggered combination of specified pin-fins and air-flow rate, the optimal spacing-to-diameter ratios corresponding to the maximum rate of heat dissipation from the array have been deduced. The effect of changing the

R. F. Babus'hag; K. Akintunde; S. D. Probert

1995-01-01

415

Fibrin self-assembly inhibitor turnover in rats  

SciTech Connect

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.

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

1987-10-01

416

Genome Sequence Databases (Overview): Sequencing and Assembly  

SciTech Connect

From the date its role in heredity was discovered, DNA has been generating interest among scientists from different fields of knowledge: physicists have studied the three dimensional structure of the DNA molecule, biologists tried to decode the secrets of life hidden within these long molecules, and technologists invent and improve methods of DNA analysis. The analysis of the nucleotide sequence of DNA occupies a special place among the methods developed. Thanks to the variety of sequencing technologies available, the process of decoding the sequence of genomic DNA (or whole genome sequencing) has become robust and inexpensive. Meanwhile the assembly of whole genome sequences remains a challenging task. In addition to the need to assemble millions of DNA fragments of different length (from 35 bp (Solexa) to 800 bp (Sanger)), great interest in analysis of microbial communities (metagenomes) of different complexities raises new problems and pushes some new requirements for sequence assembly tools to the forefront. The genome assembly process can be divided into two steps: draft assembly and assembly improvement (finishing). Despite the fact that automatically performed assembly (or draft assembly) is capable of covering up to 98% of the genome, in most cases, it still contains incorrectly assembled reads. The error rate of the consensus sequence produced at this stage is about 1/2000 bp. A finished genome represents the genome assembly of much higher accuracy (with no gaps or incorrectly assembled areas) and quality ({approx}1 error/10,000 bp), validated through a number of computer and laboratory experiments.

Lapidus, Alla L.

2009-01-01

417

Constraint-based interactive assembly planning  

SciTech Connect

The constraints on assembly plans vary depending on the product, assembly facility, assembly volume, and many other factors. This paper describes the principles and implementation of a framework that supports a wide variety of user-specified constraints for interactive assembly planning. Constraints from many sources can be expressed on a sequencing level, specifying orders and conditions on part mating operations in a number of ways. All constraints are implemented as filters that either accept or reject assembly operations proposed by the planner. For efficiency, some constraints are supplemented with special-purpose modifications to the planner`s algorithms. Replanning is fast enough to enable a natural plan-view-constrain-replan cycle that aids in constraint discovery and documentation. We describe an implementation of the framework in a computer-aided assembly planning system and experiments applying the system to several complex assemblies. 12 refs., 2 figs., 3 tabs.

Jones, R.E.; Wilson, R.H.; Calton, T.L.

1997-03-01

418

Tail assembly for an underwater vehicle  

US Patent & Trademark Office Database

An assembly for an underwater vehicle that includes a motor, a duct assembly, and an actuator. The duct assembly includes a duct and a propeller mounted within the duct, where the propeller is driven by the motor. The actuator is connected to the duct assembly and the vehicle. The actuator pivots the duct assembly with respect to the vehicle. Alternatively, the assembly includes a motor, a duct having a generally cylindrical shape oriented about a longitudinal axis, and a propeller having an axis of rotation. The propeller is mounted within the duct and is driven by the motor. The propeller and the duct are connected such that the axis of rotation and the longitudinal axis have a fixed orientation with respect to one another. The assembly includes a configuration for changing an orientation of the axis of rotation and the longitudinal axis with respect to the vehicle.

2003-06-03

419

Dynamic pathways for viral capsid assembly  

SciTech Connect

We develop a class of models with which we simulate the assembly of particles into T1 capsid-like objects using Newtonian dynamics. By simulating assembly for many different values of system parameters, we vary the forces that drive assembly. For some ranges of parameters, assembly is facile, while for others, assembly is dynamically frustrated by kinetic traps corresponding to malformed or incompletely formed capsids. Our simulations sample many independent trajectories at various capsomer concentrations, allowing for statistically meaningful conclusions. Depending on subunit (i.e., capsomer) geometries, successful assembly proceeds by several mechanisms involving binding of intermediates of various sizes. We discuss the relationship between these mechanisms and experimental evaluations of capsid assembly processes.

Hagan, Michael F.; Chandler, David

2006-02-09

420

Industrial packaging and assembly infrastructure for MOEMS  

NASA Astrophysics Data System (ADS)

In a mature industry all elements of the supply chain are available and are more or less in balance. Mainstream technologies are defined and well supported by a chain of specialist companies. Those specialist companies, offering services ranging from consultancy to manufacturing subcontracting, are an essential element in the industrialization. There specialization and dedication to one or a few elements in the technology increases professionalism and efficiency. The MOEMS industry however, is still in its infancy. After the birth and growth of many companies aiming at development of products, the appearance of companies aiming at the production of components and systems, we see know the first companies concentrating on the delivering of services to this industry. We can divide them in the like : * Design and Engineering companies * Foundries * Assembly and Packaging providers * Design and simulation software providers For manufacturing suppliers and customers the lack of industry standards and mainstream technologies is a serious drawback. Insight in availability and trends in technology is important to make the right choices in the field of industrialization and production. This awareness was the reason to perform a detailed study to the companies supplying commercial services in this field. This article focuses on one important part of this study: packaging and assembly. This tends to remain a bottleneck at the end of the design cycle, often delaying and sometimes preventing industrialization and commercialization. For nearly all MEMS/MST products literally everything comes together in the packaging and assembly. This is the area of full integration: electrical, mechanical, optical fluidic, magnetic etc. functionalities come together. The problems associated with the concentration of functionalities forms a big headache for the designer. Conflicting demands, of which functionality versus economics is only one, and technical hurdles have to overcome. Besides that, packaging and assembly is from nature application specific and solutions found are not always transferable from one product to another. But designers can often benefit from experience from other and general available technologies. A number of companies offer packaging and assembly services for MEMS/MST and this report give typical examples of those commercial services. The companies range from small start-ups, offering very specialized services, to large semiconductor packaging companies, having production lines for microsystem based products. Selecting the proper packaging method may tip the scales towards a product success or towards a product failure, while it nearly always present s a substantial part of the cost of the product. This is therefore is not a marginal concern, but a crucial part of the product design. The presentation will also address mayor trends and technologies. Finally, the article provides sufficient levels of classification and categorisation for various aspects for the technologies, in specific, and the industry, in general, to provide particularly useful insights into the activities and the developments in this market. With over 50 companies studied and assessed, it provides an up to date account of the state of this business and its future potential.

van Heeren, Henne

2004-01-01

421

Assembly of Colloidal Materials Using Bioadhesive Interactions  

NASA Astrophysics Data System (ADS)

We have pursued the use of biological crosslinking molecules of several types to make colloidal materials at relatively low volume fraction of colloidal particles. The objective is to make binary alloys of colloidal particles, made of two different colloidal particles coated with complementary biological lock-and-key binding molecules, which assemble due to the biological specificity. The long-term goal is to use low affinity lock-and-key biological interactions, so that the can anneal to form crystalline states. We have used a variety of different surface chemistries in order to make colloidal materials. Our first system involved using selectin-carbohydrate (sialyl-Lewis) interactions; this chemistry is derived from immune system. This chemical interaction is of relatively low affinity, with timescales for dissociation of several seconds. Furthermore, the adhesion mediated by these molecules can be reversed by the chelation of calcium atoms; thus assembled structures can be disassembled reversibly. Our second system employed avidin-biotin chemistry. This well-studied system is of high affinity, and is generally irreversible on a laboratory time-scale. Thus, we would expect selectin-carbohydrate interactions at high molecular density and avidin-biotin interactions to give kinetically-trapped structures; however, at low densities, we would expect significant differences in the structure and dynamics of the two materials, owing to their very different release rates. We have also begun to use a third chemistry - DNA hybridization. By attaching single stranded DNA oligonucleotide chains to beads, we can drive the assembly of colloidal materials by hybridization of complementary DNA chains. It is well known that DNA adenosine-thymine (A-T) and guanine-cytosine (G-C) bases hybridize pairwise with a Gibbs free energy change of 1.7 kcal/mol per base; thus, the energy of the assembly can be modulated by altering the number of complementary bases in the DNA chains. Using these different crosslinking molecules, we have assembled colloidal materials from different-sized colloidal particles, A and B. In the first sets of experiment, we used high densities of adhesion molecules, and 0.96 micron (A) and 5.5 micron (B) diameter particles. The high density of adhesion molecules means that the structures are kinetically trapped in nonequilibrium configurations. The structure of the suspension can be varied by changing the number ratio of the two types of colloidal particles, NA and NB, where A is the smaller particle. With carbohydrate-selectin or avidin-biotin interactions, large NA/NB leads to the formation of colloidal micelles, with the large center B particle surrounded by many smaller A particles. As the ratio NA/NB decreases, the structures become more extended, approaching the formation of macro-Rouse polymers - extended linear chains where A beads are connected with intervening small B linkers.

Hammer, Daniel A.; Hiddessen, Amy L.; Tohver, Valeria; Crocker, John C.; Weitz, David A.

2002-11-01

422

Fuel assembly self-excited vibration and test methodology  

SciTech Connect

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)

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

423

Phase field method for nonequilibrium dynamics of reversible self-assembly systems.  

PubMed

Phase field methods are extended to describe the nonequilibrium dynamics of reversible self-assembly systems, an extension that is complicated by the mutual coupling of many non-conserved order parameters into a set of highly nonlinear partial differential equations. Further complications arise because the sum of all non-conserved order parameters equals a conserved order parameter. The theory is developed for the simplest model of reversible self-assembly in which no additional constraints are imposed on the self-assembly process since the extension to treat more complex self-assembly models is straightforward. Specific calculations focus on the time evolution of the cluster size distribution for a free association system that is rapidly dropped from one ordered state to a more ordered state within the one-phase region. The dynamics proceed as expected, thereby providing validation of the theory which is also capable of treating systems with spatial inhomogeneities. PMID:24116582

Freed, Karl F

2013-10-01

424

Phase field method for nonequilibrium dynamics of reversible self-assembly systems  

NASA Astrophysics Data System (ADS)

Phase field methods are extended to describe the nonequilibrium dynamics of reversible self-assembly systems, an extension that is complicated by the mutual coupling of many non-conserved order parameters into a set of highly nonlinear partial differential equations. Further complications arise because the sum of all non-conserved order parameters equals a conserved order parameter. The theory is developed for the simplest model of reversible self-assembly in which no additional constraints are imposed on the self-assembly process since the extension to treat more complex self-assembly models is straightforward. Specific calculations focus on the time evolution of the cluster size distribution for a free association system that is rapidly dropped from one ordered state to a more ordered state within the one-phase region. The dynamics proceed as expected, thereby providing validation of the theory which is also capable of treating systems with spatial inhomogeneities.

Freed, Karl F.

2013-10-01

425

Determination of BWR Spent Nuclear Fuel Assembly Effective Thermal Conductivity  

SciTech Connect

The purpose of this calculation is to provide an effective thermal conductivity for use in predicting peak cladding temperatures in boiling water reactor (BWR) fuel assemblies with 7x7,8x8, and 9x9 rod arrays. The first objective of this calculation is to describe the development and application of a finite element representation that predicts peak spent nuclear fuel temperatures for BWR assemblies. The second objective is to use the discrete representation to develop a basis for determining an effective thermal conductivity (described later) for a BWR assembly with srneared/homogeneous properties and to investigate the thermal behavior of a spent fuel assembly. The scope of this calculation is limited to a steady-state two-dimensional representation of the waste package interior region. This calculation is subject to procedure AP-3.124, Calculations (Ref. 27) and guided by the applicable technical work plan (Ref. 14). While these evaluations were originally developed for the thermal analysis of conceptual waste package designs emplaced in the potential repository at Yucca Mountain, the methodology applies to storage and transportation thermal analyses as well. Note that the waste package sketch in Attachment V depicts a preliminary design, and should not be interpreted otherwise.

Matthew D. Hinds

2001-10-17

426

Self-Assembled Magnetic Filter for Highly Efficient Immunomagnetic Separation  

PubMed Central

We have developed a compact and inexpensive microfluidic chip, the Self Assembled Magnetic filter, to efficiently remove magnetically tagged cells from suspension. The self-assembled magnetic filter consists of a microfluidic channel built directly above a self-assembled NdFeB magnet. Micrometer-sized grains of NdFeB assemble to form alternating magnetic dipoles, creating a magnetic field with a very strong magnitude B (from the material) and field gradient ?B (from the configuration) in the microfluidic channel. The magnetic force imparted on magnetic beads is measured to be comparable to state-of-the-art microfabricated magnets, allowing for efficient separations to be performed in a compact, simple device. The efficiency of the magnetic filter is characterized by sorting non-magnetic (polystyrene) beads from magnetic beads (iron oxide). The filter enriches the population of non-magnetic beads to magnetic beads by a factor of >105 with a recovery rate of 90% at 1 mL/hr. The utility of the magnetic filter is demonstrated with a microfluidic device that sorts tumor cells from leukocytes using negative immunomagnetic selection, and concentrates the tumor cells on an integrated membrane filter for optical detection.

Issadore, David; Shao, Huilin; Chung, Jaehoon; Newton, Andita; Pittet, Mikael; Weissleder, Ralph; Lee, Hakho

2010-01-01

427

Effects of x irradiation on microtubule assembly in vitro  

SciTech Connect

Microtubular proteins isolated from beef brains were x-irradiated (500 to 30,000 rad) in the assembled or unassembled state in virto, and the effects of radiation on the samples were examined. Samples were irradiated in a water bath at 0 (ice slurry), 22 or 24, and 37/sup 0/C. The assembly of microtubules was monitored by following changes in optical density at 340 nm and/or changes in specific viscosity, combined with electron microscopy of the samples at various stages of experimentation. Samples containing microtubles were 30 (22/sup 0/C) to 50% (37/sup 0/C) more sensitive to inactivation by irradiation than samples containing unassembled microtubular proteins. Doses between 500 and 2000 rad had little effect on the assembly competency of the microtubular proteins. Doses of 5000 to 30,000 rad reproducibility inhibited the assembly of microtubules. More than 80% of the observed inactivation of microtubular proteins by 30,000 rad can be accounted for by the oxidation of critical sulfhydryls.

Coss, R.A.; Bamburg, J.R.; Dewey, W.C.

1981-01-01

428

Self-Assembly of Globular Protein-Polymer Diblock Copolymers  

NASA Astrophysics Data System (ADS)

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.

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

2011-03-01

429

Macromolecular assembly of polycystin-2 intracytosolic C-terminal domain  

PubMed Central

Mutations in PKD2 are responsible for approximately 15% of the autosomal dominant polycystic kidney disease cases. This gene encodes polycystin-2, a calcium-permeable cation channel whose C-terminal intracytosolic tail (PC2t) plays an important role in its interaction with a number of different proteins. In the present study, we have comprehensively evaluated the macromolecular assembly of PC2t homooligomer using a series of biophysical and biochemical analyses. Our studies, based on a new delimitation of PC2t, have revealed that it is capable of assembling as a homotetramer independently of any other portion of the molecule. Our data support this tetrameric arrangement in the presence and absence of calcium. Molecular dynamics simulations performed with a modified all-atoms structure-based model supported the PC2t tetrameric assembly, as well as how different populations are disposed in solution. The simulations demonstrated, indeed, that the best-scored structures are the ones compatible with a fourfold oligomeric state. These findings clarify the structural properties of PC2t domain and strongly support a homotetramer assembly of PC2.

Ferreira, Frederico M.; Oliveira, Leandro C.; Germino, Gregory G.; Onuchic, Jose N.; Onuchic, Luiz F.

2011-01-01

430

Characterization of photosynthetic supramolecular assemblies using small angle neutron scattering  

SciTech Connect

We are using small angle neutron scattering (SANS) to resolve structural features of supramolecular assemblies of photosynthetic proteins in liquid and frozen solutions. SANS resolves the size, shape, and structural homogeneity of macromolecular assemblies in samples identical to those used for spectroscopic assays of photosynthetic function. Likely molecular structures of the supramolecular assemblies can be identified by comparing experimental scattering data with scattering profiles calculated for model supramolecular assemblies built from crystal structures of the individual proteins. SANS studies of the Rhodobacter sphaeroides reaction center, RC, presented here, show that the detergent solubilized RC exists in a variety of monomeric and aggregation states. The distribution between monomer and aggregate was found to depend strongly upon detergent, temperature and nature of additives, such as ethylene glycol used for low temperature spectroscopy and polyethylene glycol used for crystallization. Likely aggregate structures are being identified by fitting the experimental scattering profiles with those calculated for model aggregates built-up using the RC crystal structure. This work establishes the foundation for using SANS to identify intermediates in the RC crystallization pathways, and for determining likely structures of complexes formed between the RC and its physiological reaction partners, cytochrome c, and the LHI antenna complex.

Tiede, D.M.; Marone, P.; Wagner, A.M.; Thiyagarajan, P.

1995-12-31

431

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

SciTech Connect

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.

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

2008-04-08

432

Interfacial Assembly of Graphene Oxide Sheets  

NASA Astrophysics Data System (ADS)

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.

Cote, Laura J.

433

Solvent mediated self-assembly of solids  

SciTech Connect

Solvent-mediated crystallization represents a robust approach to self-assembly of nanostructures and microstructures. In organic systems, the relative ease with which the structure of hydrogen- bonded molecules can be manipulated allows for generation of a wide variety of nanoscale crystal structures. In living organisms, control over the micron-to-millimeter form of inorganic crystals is achieved through introduction of bio-organic molecules. The purpose of this proposal is to understand the interplay between solution chemistry, molecular structure, surface chemistry, and the processes of nucleation and crystal growth in solvent-mediated systems, with the goal of developing the atomic and molecular basis of a solvent-mediated self-assembly technology. We will achieve this purpose by: (1) utilizing an atomic force microscopy (AFM) approach that provides in situ, real time imaging during growth from solutions, (2) by modifying kinetic Monte Carlo (KMC) models to include solution-surface kinetics, (3) by introducing quantum chemistry (QC) calculations of the potentials of the relevant chemical species and the near-surface structure of the solution, and (4) by utilizing molecular dynamics (MD) simulations to identify the minimum energy pathways to the solid state. Our work will focus on two systems chosen to address both the manometer and micron-to-millimeter length scales of assembly, the family of 2,5- diketopiperazines (X-DKPs) and the system of CaCO{sub 3} with amino acids. Using AFM, we will record the evolution of surface morphology, critical lengths, step speeds, and step-step interactions as a function of supersaturation and temperature. In the case of the X-DKPs, these measurements will be repeated as the molecular structure of the growth unit is varied. In the case of CaCO{sub 3}, they will be performed as a function of solution chemistry including pH, ionic strength, and amino acid content. In addition, we will measure nucleation rates and orientations of CaCO{sub 3} on polyamino acid templates. From these measurements, we will extract fundamental growth parameters for input into KMC simulations whose predictions will in turn be compared to the experimental observations. The KMC simulations will incorporate atomic processes representing the minimum energy pathways as determined from the MD calculations. The interaction potentials of the relevant chemical species as well as the hydrated surface, including the electrochemical double layer, used in the MD simulations will be determined using coupled solutions to the Schrodinger and Poisson-Boltzmann equations which take account of electronic relaxation effects.

De Yoreo, J.; Wilson, W.D.; Palmore, T.

1997-12-12

434

Kinetically controlled self-assembly of redox-active ferrocene-diphenylalanine: from nanospheres to nanofibers.  

PubMed

Putting metals into organic compounds such as peptides can lead to many new desirable properties. Here we designed a novel bioorganometallic molecule, ferrocene-diphenylalanine (Fc-FF), and investigated its self-assembly behavior. We directly observed a morphological transition from metastable nanospheres to nanofibers, which led to the formation of a self-supporting hydrogel. The strong hydrophobic interaction of the Fc moiety was suggested to have a key role in this kinetically controlled self-assembly process. Moreover, the redox center of the ferrocene group further allowed us to reversibly control the self-assembly behavior of Fc-FF by altering its redox state. PMID:24157576

Wang, Yuefei; Huang, Renliang; Qi, Wei; Wu, Zhongjie; Su, Rongxin; He, Zhimin

2013-10-24

435

State Environmental Resource Center  

NSDL National Science Digital Library

This website provides information on Wisconsin environmental policies and assembles information and tools to help legislators make decisions on environmental issues. The State Environmental Resource Center identifies effective state policies as well as exposing anti-environmental legislative trends. Included in this site are sample bills, press clips, fact sheets, research, and other background information on a large assortment of environmental issues such as clean energy, urban issues, saving wildlands, safe air and water, children's health, land and water use, and environmental citizenship.

Wildlife, Defenders O.; The State Environmental Resource Center (SERC)

436

End-of-irradiation data report for the instrumented fuel assembly (IFA)-527. [PWR; BWR  

Microsoft Academic Search

This report presents data obtained during the irradiation of the six-rod instrumented fuel assembly (IFA)-527 in the Halden Boiling Water Reactor (HBWR), Halden, Norway. This assembly is the last in a series of US Nuclear Regulatory Commission (NRC)-sponsored tests to obtain data for the development and verification of steady-state fuel performance computer codes. IFA-527 contains five identical rods with high-density

M. E. Cunningham; D. D. Lanning

1982-01-01

437

Long-lived assembly structures in the lithosphere of southwestern North America  

Microsoft Academic Search

The assembly of the continental lithosphere of the southwestern United States occurred between 1.8--1.6Ga, when a succession of island arcs collided with the Archean-age Wyoming province. The accretion established northeast-striking boundaries and tectonic provinces that have influenced the tectonic and magmatic history of the North American craton. Many of these assembly structures and the sutures between accreted island arcs and

M. B. Magnani; A. Levander; K. C. Miller; K. E. Karlstrom

2003-01-01

438

j5 DNA assembly design automation software.  

PubMed

Recent advances in Synthetic Biology have yielded standardized and automatable DNA assembly protocols that enable a broad range of biotechnological research and development. Unfortunately, the experimental design required for modern scar-less multipart DNA assembly methods is frequently laborious, time-consuming, and error-prone. Here, we report the development and deployment of a web-based software tool, j5, which automates the design of scar-less multipart DNA assembly protocols including SLIC, Gibson, CPEC, and Golden Gate. The key innovations of the j5 design process include cost optimization, leveraging DNA synthesis when cost-effective to do so, the enforcement of design specification rules, hierarchical assembly strategies to mitigate likely assembly errors, and the instruction of manual or automated construction of scar-less combinatorial DNA libraries. Using a GFP expression testbed, we demonstrate that j5 designs can be executed with the SLIC, Gibson, or CPEC assembly methods, used to build combinatorial libraries with the Golden Gate assembly method, and applied to the preparation of linear gene deletion cassettes for E. coli. The DNA assembly design algorithms reported here are generally applicable to broad classes of DNA construction methodologies and could be implemented to supplement other DNA assembly design tools. Taken together, these innovations save researchers time and effort, reduce the frequency of user design errors and off-target assembly products, decrease research costs, and enable scar-less multipart and combinatorial DNA construction at scales unfeasible without computer-aided design. PMID:23651006

Hillson, Nathan J; Rosengarten, Rafael D; Keasling, Jay D

2011-12-20

439

The BAGEL assembler generation library  

NASA Astrophysics Data System (ADS)

This paper presents two coupled software packages which receive widespread use in the field of numerical simulations of Quantum Chromo-Dynamics. These consist of the BAGEL library and the BAGEL fermion sparse-matrix library, BFM. The Bagel library can generate assembly code for a number of architectures and is configurable - supporting several precision and memory pattern options to allow architecture specific optimisation. It provides high performance on the QCDOC, BlueGene/L and BlueGene/P parallel computer architectures that are popular in the field of lattice QCD. The code includes a complete conjugate gradient implementation for the Wilson and domain wall fermion actions, making it easy to use for third party codes including the Jefferson Laboratory's CHROMA, UKQCD's UKhadron, and the Riken-Brookhaven-Columbia Collaboration's CPS packages. Catalogue identifier: AEFE_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFE_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU Public License V2 No. of lines in distributed program, including test data, etc.: 109?576 No. of bytes in distributed program, including test data, etc.: 892?841 Distribution format: tar.gz Programming language: C++, assembler Computer: Massively parallel message passing. BlueGene/QCDOC/others. Operating system: POSIX, Linux and compatible. Has the code been vectorised or parallelized?: Yes. 16?384 processors used. Classification: 11.5 External routines: QMP, QDP++ Nature of problem: Quantum Chromo-Dynamics sparse matrix inversion for Wilson and domain wall fermion formulations. Solution method: Optimised Krylov linear solver. Unusual features: Domain specific compiler generates optimised assembly code. Running time: 1 h per matrix inversion; multi-year simulations.

Boyle, Peter A.

2009-12-01

440

Templating Surfaces with Gradient Assemblies  

SciTech Connect

One of the most versatile and widely used methods of forming surfaces with position-dependent wettability is that conceived by Chaudhury and Whitesides more than a decade ago. In this paper we review several projects that utilize this gradient-forming methodology for: controlled of deposition of self-assembled monolayers on surfaces, generating arrays of nanoparticles with number density gradients, probing the mushroom-to-brush transition in surface-anchored polymers, and controlling the speed of moving liquid droplets on surfaces.

Genzer,J.

2005-01-01

441

Self-assembling magnetic "snakes"  

ScienceCinema

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.

442

Spray-ring mounting assembly  

SciTech Connect

This patent describes a thrust augmentation combustor for a gas turbine engine having a duct, an assembly for mounting a spray ring or the like to the duct and having improved vibration isolation characteristics. It comprises a clevis arranged for fixed mounting to the duct, a circular pin mounted in the clevis, an elongated slider having a central circular axial bore and mounted for rotational movement on the pin, the slider having at least two parallel exterior sidewalls, and a bracket for mounting the spray ring having an elongated bore mounted on the slider.

Barcza, W.K.; Concordia, M.J.

1992-07-07

443

Brave New World at the General Assembly: The United Nations Declaration on Human Cloning  

Microsoft Academic Search

In the first year of the new millennium, a little-reported controversy began to unfold at the United Nations General Assembly (UNGA). The resulting debate spanned four sessions of the UNGA and roiled capitals around the globe. It seriously divided the United States and the United Kingdom, at a time when these two States were the closest of allies on issues

Anna V. Henderson

444

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

PubMed

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

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

2013-09-17

445

Photoswitchable gel assembly based on molecular recognition.  

PubMed

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

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

2012-01-03

446

The MARVEL assembly for neutron multiplication.  

PubMed

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 11.4cm in diameter and having a combined height of up to 11.7cm. The combined mass of all three cylinders is 20.3kg 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. PMID:23827507

Chichester, David L; Kinlaw, Mathew T

2013-06-10

447

The effect of chemical chaperones on the assembly and stability of HIV-1 capsid protein.  

PubMed

Chemical chaperones are small organic molecules which accumulate in a broad range of organisms in various tissues under different stress conditions and assist in the maintenance of a correct proteostasis under denaturating environments. The effect of chemical chaperones on protein folding and aggregation has been extensively studied and is generally considered to be mediated through non-specific interactions. However, the precise mechanism of action remains elusive. Protein self-assembly is a key event in both native and pathological states, ranging from microtubules and actin filaments formation to toxic amyloids appearance in degenerative disorders, such as Alzheimer's and Parkinson's diseases. Another pathological event, in which protein assembly cascade is a fundamental process, is the formation of virus particles. In the late stage of the virus life cycle, capsid proteins self-assemble into highly-ordered cores, which encapsulate the viral genome, consequently protect genome integrity and mediate infectivity. In this study, we examined the effect of different groups of chemical chaperones on viral capsid assembly in vitro, focusing on HIV-1 capsid protein as a system model. We found that while polyols and sugars markedly inhibited capsid assembly, methylamines dramatically enhanced the assembly rate. Moreover, chemical chaperones that inhibited capsid core formation, also stabilized capsid structure under thermal denaturation. Correspondingly, trimethylamine N-oxide, which facilitated formation of high-order assemblies, clearly destabilized capsid structure under similar conditions. In contrast to the prevailing hypothesis suggesting that chemical chaperones affect proteins through preferential exclusion, the observed dual effects imply that different chaperones modify capsid assembly and stability through different mechanisms. Furthermore, our results indicate a correlation between the folding state of capsid to its tendency to assemble into highly-ordered structures. PMID:23577173

Lampel, Ayala; Bram, Yaron; Levy-Sakin, Michal; Bacharach, Eran; Gazit, Ehud

2013-04-05

448

The Effect of Chemical Chaperones on the Assembly and Stability of HIV-1 Capsid Protein  

PubMed Central

Chemical chaperones are small organic molecules which accumulate in a broad range of organisms in various tissues under different stress conditions and assist in the maintenance of a correct proteostasis under denaturating environments. The effect of chemical chaperones on protein folding and aggregation has been extensively studied and is generally considered to be mediated through non-specific interactions. However, the precise mechanism of action remains elusive. Protein self-assembly is a key event in both native and pathological states, ranging from microtubules and actin filaments formation to toxic amyloids appearance in degenerative disorders, such as Alzheimer's and Parkinson's diseases. Another pathological event, in which protein assembly cascade is a fundamental process, is the formation of virus particles. In the late stage of the virus life cycle, capsid proteins self-assemble into highly-ordered cores, which encapsulate the viral genome, consequently protect genome integrity and mediate infectivity. In this study, we examined the effect of different groups of chemical chaperones on viral capsid assembly in vitro, focusing on HIV-1 capsid protein as a system model. We found that while polyols and sugars markedly inhibited capsid assembly, methylamines dramatically enhanced the assembly rate. Moreover, chemical chaperones that inhibited capsid core formation, also stabilized capsid structure under thermal denaturation. Correspondingly, trimethylamine N-oxide, which facilitated formation of high-order assemblies, clearly destabilized capsid structure under similar conditions. In contrast to the prevailing hypothesis suggesting that chemical chaperones affect proteins through preferential exclusion, the observed dual effects imply that different chaperones modify capsid assembly and stability through different mechanisms. Furthermore, our results indicate a correlation between the folding state of capsid to its tendency to assemble into highly-ordered structures.

Lampel, Ayala; Bram, Yaron; Levy-Sakin, Michal; Bacharach, Eran; Gazit, Ehud

2013-01-01

449

ATP-dependent human RISC assembly pathways  

Microsoft Academic Search

The assembly of RNA-induced silencing complex (RISC) is a key process in small RNA–mediated gene silencing. In humans, small interfering RNAs (siRNAs) and microRNAs (miRNAs) are incorporated into RISCs containing the Argonaute (AGO) subfamily proteins Ago1–4. Previous studies have proposed that, unlike Drosophila melanogaster RISC assembly pathways, human RISC assembly is coupled with dicing and is independent of ATP. Here

Mayuko Yoda; Tomoko Kawamata; Zain Paroo; Xuecheng Ye; Shintaro Iwasaki; Qinghua Liu; Yukihide Tomari

2009-01-01

450

A Versatile Computer-Controlled Assembly System  

Microsoft Academic Search

Abstract A versatile assembly system, using TV cameras and oomputer-controlled arm and moving table, is described. It makes almple,assemblies,such aa a peg and rings and a toy car. It separates parts from a heap, recognising them with an overhead camera, then assembles them by feel.,It can be instructed,to perform a new task with different,parte by spending,an hour showing,it the parts

A. P. Ambler; Harry G. Barrow; Christopher M. Brown; Rod M. Burstall; Robin J. Popplestone

1973-01-01

451

Distributed agreement in tile self-assembly  

Microsoft Academic Search

Laboratory investigations have shown that a formal theory of fault-tolerance will be essential to harness nanoscale self-assembly\\u000a as a medium of computation. Several researchers have voiced an intuition that self-assembly phenomena are related to the field\\u000a of distributed computing. This paper formalizes some of that intuition. We construct tile assembly systems that are able to\\u000a simulate the solution of the

Aaron Sterling

2011-01-01

452

Distributed Agreement in Tile Self-Assembly  

Microsoft Academic Search

Laboratory investigations have shown that a formal theory of fault-tolerance will be essen- tial to harness nanoscale self-assembly as a medium of computation. Several researchers have voiced an intuition that self-assembly phenomena are related to the field of distributed computing. This paper formalizes some of that intuition. We construct tile assembly systems that are able to simulate the so- lution

Aaron Sterling

2009-01-01

453

Formal Verification of Self-Assembling Systems  

Microsoft Academic Search

This paper introduces the theory and practice of formal verification of\\u000aself-assembling systems. We interpret a well-studied abstraction of\\u000ananomolecular self assembly, the Abstract Tile Assembly Model (aTAM), into\\u000aComputation Tree Logic (CTL), a temporal logic often used in model checking. We\\u000athen consider the class of \\

Aaron Sterling

2010-01-01

454

Self-Assembly at All Scales  

Microsoft Academic Search

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.

George M. Whitesides; Bartosz Grzybowski

2002-01-01

455

Simultaneous remote haptic collaboration for assembling tasks  

Microsoft Academic Search

Stand-alone virtual environments (VEs) using haptic devices have proved useful for assembly\\/disassembly simulation of mechanical\\u000a components. Nowadays, collaborative haptic virtual environments (CHVEs) are also emerging. A new peer-to-peer collaborative\\u000a haptic assembly simulator (CHAS) has been developed whereby two users can simultaneously carry out assembly tasks using haptic\\u000a devices. Two major challenges have been addressed: virtual scene synchronization (consistency) and the

Rosa Iglesias; Sara Casado; Teresa Gutiérrez; Alejandro García-alonso; Wai Yu; Alan Marshall

2008-01-01

456

From system F to typed assembly language  

Microsoft Academic Search

We motivate the design of typed assembly language (TAL) and present a type-preserving ttranslation from Systemn F to TAL. The typed assembly language we pressent is based on a conventional RISC assembly language, but its static type sytem provides support for enforcing high-level language abstratctions, such as closures, tuples, and user-defined abstract data types. The type system ensures that well-typed

Greg Morrisett; David Walker; Karl Crary; Neal Glew

1999-01-01

457

Reusable fuel test assembly for the FFTF  

SciTech Connect

A fuel test assembly for use in the Fast Flux Test Facility (FFTF) has been developed that provides re-irradiation capability after interim discharge and reconstitution of the test pin bundle. This test vehicle permits irradiation test data to be obtained at multiple exposures on a few select test pins without the substantial expense of fabricating individual test assemblies as would otherwise be required. A variety of different test pin types can be loaded in the reusable test assembly.

Pitner, A.L.; Dittmer, J.O.

1992-03-01

458

Balancing parallel two-sided assembly lines  

Microsoft Academic Search

Two-sided assembly lines are usually designed to produce large-sized products such as automobiles, trucks and buses. In this type of production line, both left-side and right-side of the line are used. In parallel assembly lines, one or more product types are produced on two or more assembly lines located in parallel to each other. Both production lines have several serious

U?ur Özcan; Hadi Gökçen; Bilal Toklu

2010-01-01

459

A Typed Assembly Language for Confidentiality  

Microsoft Academic Search

Language-based information-flow analysis is promising in pro- tecting data confidentiality. Although much work has been carried out in this area, relatively little has been done for assembly code. Techniques at a source level do not generalize straightforwardly to assembly code, because assembly code does not readily present certain abstraction about the program structure that is crucial to information-flow analysis. Nonetheless,

Dachuan Yu; Nayeem Islam

2006-01-01

460

Ultra-precision positioning assembly  

DOEpatents

An apparatus and method is disclosed for ultra-precision positioning. A slide base provides a foundational support. A slide plate moves with respect to the slide base along a first geometric axis. Either a ball-screw or a piezoelectric actuator working separate or in conjunction displaces the slide plate with respect to the slide base along the first geometric axis. A linking device directs a primary force vector into a center-line of the ball-screw. The linking device consists of a first link which directs a first portion of the primary force vector to an apex point, located along the center-line of the ball-screw, and a second link for directing a second portion of the primary force vector to the apex point. A set of rails, oriented substantially parallel to the center-line of the ball-screw, direct movement of the slide plate with respect to the slide base along the first geometric axis and are positioned such that the apex point falls within a geometric plane formed by the rails. The slide base, the slide plate, the ball-screw, and the linking device together form a slide assembly. Multiple slide assemblies can be distributed about a platform. In such a configuration, the platform may be raised and lowered, or tipped and tilted by jointly or independently displacing the slide plates.

Montesanti, Richard C. (San Francisco, CA); Locke, Stanley F. (Livermore, CA); Thompson, Samuel L. (Pleasanton, CA)

2002-01-01

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