PRELIMINARY SELECTION OF MGR DESIGN BASIS EVENTS

International Nuclear Information System (INIS)

Kappes, J.A.

1999-01-01

The purpose of this analysis is to identify the preliminary design basis events (DBEs) for consideration in the design of the Monitored Geologic Repository (MGR). For external events and natural phenomena (e.g., earthquake), the objective is to identify those initiating events that the MGR will be designed to withstand. Design criteria will ensure that radiological release scenarios resulting from these initiating events are beyond design basis (i.e., have a scenario frequency less than once per million years). For internal (i.e., human-induced and random equipment failures) events, the objective is to identify credible event sequences that result in bounding radiological releases. These sequences will be used to establish the design basis criteria for MGR structures, systems, and components (SSCs) design basis criteria in order to prevent or mitigate radiological releases. The safety strategy presented in this analysis for preventing or mitigating DBEs is based on the preclosure safety strategy outlined in ''Strategy to Mitigate Preclosure Offsite Exposure'' (CRWMS M andO 1998f). DBE analysis is necessary to provide feedback and requirements to the design process, and also to demonstrate compliance with proposed 10 CFR 63 (Dyer 1999b) requirements. DBE analysis is also required to identify and classify the SSCs that are important to safety (ITS)

The Staphylococcus aureus Global Regulator MgrA Modulates Clumping and Virulence by Controlling Surface Protein Expression.

Directory of Open Access Journals (Sweden)

Heidi A Crosby

2016-05-01

Full Text Available Staphylococcus aureus is a human commensal and opportunistic pathogen that causes devastating infections in a wide range of locations within the body. One of the defining characteristics of S. aureus is its ability to form clumps in the presence of soluble fibrinogen, which likely has a protective benefit and facilitates adhesion to host tissue. We have previously shown that the ArlRS two-component regulatory system controls clumping, in part by repressing production of the large surface protein Ebh. In this work we show that ArlRS does not directly regulate Ebh, but instead ArlRS activates expression of the global regulator MgrA. Strains lacking mgrA fail to clump in the presence of fibrinogen, and clumping can be restored to an arlRS mutant by overexpressing either arlRS or mgrA, indicating that ArlRS and MgrA constitute a regulatory pathway. We used RNA-seq to show that MgrA represses ebh, as well as seven cell wall-associated proteins (SraP, Spa, FnbB, SasG, SasC, FmtB, and SdrD. EMSA analysis showed that MgrA directly represses expression of ebh and sraP. Clumping can be restored to an mgrA mutant by deleting the genes for Ebh, SraP and SasG, suggesting that increased expression of these proteins blocks clumping by steric hindrance. We show that mgrA mutants are less virulent in a rabbit model of endocarditis, and virulence can be partially restored by deleting the genes for the surface proteins ebh, sraP, and sasG. While mgrA mutants are unable to clump, they are known to have enhanced biofilm capacity. We demonstrate that this increase in biofilm formation is partially due to up-regulation of SasG, a surface protein known to promote intercellular interactions. These results confirm that ArlRS and MgrA constitute a regulatory cascade, and that they control expression of a number of genes important for virulence, including those for eight large surface proteins.

ASSEMBLY TRANSFER SYSTEM DESCRIPTION DOCUMENT

International Nuclear Information System (INIS)

Gorpani, B.

2000-01-01

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

Phosphorylation of MgrA and its effect on expression of the NorA and NorB efflux pumps of Staphylococcus aureus.

Science.gov (United States)

Truong-Bolduc, Que Chi; Hooper, David C

2010-05-01

MgrA is a global regulator in Staphylococcus aureus that controls the expression of diverse genes encoding virulence factors and multidrug resistance (MDR) efflux transporters. We identified pknB, which encodes the (Ser/Thr) kinase PknB, in the S. aureus genome. PknB was able to autophosphorylate as well as phosphorylate purified MgrA. We demonstrated that rsbU, which encodes a Ser/Thr phosphatase and is involved in the activation of the SigB regulon, was able to dephosphorylate MgrA-P but not PknB-P. Serines 110 and 113 of MgrA were found to be phosphorylated, and Ala substitutions at these positions resulted in reductions in the level of phosphorylation of MgrA. DNA gel shift binding assays using norA and norB promoters showed that MgrA-P was able to bind the norB promoter but not the norA promoter, a pattern which was the reverse of that for unphosphorylated MgrA. The double mutant MgrA(S110A-S113A) bound to the norA promoter but not the norB promoter. The double mutant led to a 2-fold decrease in norA transcripts and a 2-fold decrease in the MICs of norfloxacin and ciprofloxacin in strain RN6390. Thus, phosphorylation of MgrA results in loss of binding to the norA promoter, but with a gain of the ability to bind the norB promoter. Loss of the ability to phosphorylate MgrA by Ala substitution resulted in increased repression of norA expression and in reductions in susceptibilities to NorA substrates.

The charge transfer structure and effective energy transfer in multiplayer assembly film

International Nuclear Information System (INIS)

Li Mingqiang; Jian Xigao

2005-01-01

Charge transfer multiplayer films have been prepared by layer-by-layer self-assembly technique. The films incorporate the rare-earth-containing polyoxometalate K 11 [Eu{PW 11 O 39 } 2 ].nH 2 O and the rich electron polyelectrolyte poly(3-viny-1-methyl-pyridine) quaternary ammonium and display a linear increase in the absorption and film thickness with the number of deposition cycles. Ultraviolet and visible absorption spectra, atomic force micrographs, small-angle X-ray reflectivity measurements, and photoluminescence spectra were used to determine the structure of films. Linear and regular multilayer growth was observed. We can observe the formation of charge transfer complex compound in multiplayer by layer-by-layer assembly method. Most importantly, the luminescence spectra show the charge transfer band in assembly films, which suggest that energy could be effectively transferred to rare earth ions in assembly multiplayer films

Transfer of fuel assemblies

International Nuclear Information System (INIS)

Vuckovich, M.; Burkett, J. P.; Sallustio, J.

1984-01-01

Fuel assemblies of a nuclear reactor are transferred during fueling or refueling or the like by a crane. The work-engaging fixture of the crane picks up an assembly, removes it from this slot, transfers it to the deposit site and deposits it in its slot at the deposit site. The control for the crane includes a strain gauge connected to the crane line which raises and lowers the load. The strain gauge senses the load on the crane. The signal from the strain gauge is compared with setpoints; a high-level setpoint, a low-level setpoint and a slack-line setpoint. If the strain gauge signal exceeds the high-level setpoint, the line drive is disabled. This event may occur during raising of a fuel assembly which encounters resistance. The high-level setpoint may be overridden under proper precautions. The line drive is also disabled if the strain gauge signal is less than the low-level setpoint. This event occurs when a fuel assembly being deposited contacts the bottom of its slot or an obstruction in, or at the entry to the slot. To preclude lateral movement and possible damage to a fuel assembly suspended from the crane line, the traverse drive of the crane is disabled once the strain-gauge exceets the lov-level setpoint. The traverse drive can only be enabled after the strain-gauge signal is less than the slack-line set-point. This occurs when the lines has been set in slack-line setting. When the line is tensioned after slack-li ne setting, the traverse drive remains enabled only if the line has been disconnected from the fuel assembly

Fuel assembly transfer and storage system for nuclear reactors

International Nuclear Information System (INIS)

Allain, Albert; Thomas, Claude.

1981-01-01

Transfer and storage system on a site comprising several reactors and at least one building housing the installations common to all these reactors. The system includes: transfer and storage modules for the fuel assemblies comprising a containment capable of containing several assemblies carried on a transport vehicle, a set of tracks for the modules between the reactors and the common installations, handling facilities associated with each reactor for moving the irradiated assemblies from the reactor to a transfer module placed in loading position on a track serving the reactor and conversely to move the new assemblies from the transfer module to the reactor, and at least one handling facility located in the common installation building for loading the modules with new assemblies [fr

Gold(I) Complexes with N-Donor Ligands. 2.(1) Reactions of Ammonium Salts with [Au(acac-kappaC(2))(PR(3))] To Give [Au(NH(3))L](+), [(AuL)(2)(&mgr;(2)-NH(2))](+), [(AuL)(4)(&mgr;(4)-N)](+), or [(AuL)(3)(&mgr;(3)-O)](+). A New and Facile Synthesis of [Au(NH(3))(2)](+) Salts. Crystal Structure of [{AuP(C(6)H(4)OMe-4)(3)}(3)(&mgr;(3)-O)]CF(3)SO(3).

Science.gov (United States)

Vicente, José; Chicote, María-Teresa; Guerrero, Rita; Jones, Peter G.; Ramírez De Arellano, M. Carmen

1997-09-24

The complexes [Au(acac-kappaC(2))(PR(3))] (acac = acetylacetonate, R = Ph, C(6)H(4)OMe-4) react with (NH(4))ClO(4) to give amminegold(I), [Au(NH(3))(PR(3))]ClO(4), amidogold(I), [(AuPR(3))(2)(&mgr;(2)-NH(2))]ClO(4), or nitridogold(I), [(AuPR(3))(4)(&mgr;(4)-N)]ClO(4), complexes, depending on the reaction conditions. Similarly, [Au(acac-kappaC(2))(PPh(3))] reacts with (NH(3)R')OTf (OTf = CF(3)SO(3)) (1:1) or with [H(3)N(CH(2))(2)NH(2)]OTf (1:1) to give (amine)gold(I) complexes [Au(NH(2)R')(PPh(3))]OTf (R' = Me, C(6)H(4)NO(2)-4) or [(AuPPh(3))(2){&mgr;(2)-H(2)N(CH(2))(2)NH(2)}](OTf)(2), respectively. The ammonium salts (NH(2)R'(2))OTf (R' = Et, Ph) react with [Au(acac-kappaC(2))(PR(3))] (R = Ph, C(6)H(4)OMe-4) (1:2) to give, after hydrolysis, the oxonium salts [(AuPR(3))(3)(&mgr;(3)-O)]OTf (R = Ph, C(6)H(4)OMe-4). When NH(3) is bubbled through a solution of [AuCl(tht)] (tht = tetrahydrothiophene), the complex [Au(NH(3))(2)]Cl precipitates. Addition of [Au(NH(3))(2)]Cl to a solution of AgClO(4) or TlOTf leads to the isolation of [Au(NH(3))(2)]ClO(4) or [Au(NH(3))(2)]OTf, respectively. The crystal structure of [(AuPR(3))(3)(&mgr;(3)-O)]OTf.Me(2)CO (R = C(6)H(4)OMe-4) has been determined: triclinic, space group P&onemacr;, a = 14.884(3) Å, b = 15.828(3) Å, c = 16.061(3) Å, alpha = 83.39(3) degrees, beta = 86.28(3) degrees, gamma = 65.54(3) degrees, R1 (wR2) = 0.0370 (0.0788). The [(AuPR(3))(3)(&mgr;(3)-O)](+) cation shows an essentially trigonal pyramidal array of three gold atoms and one oxygen atom with O-Au-P bond angles of ca. 175 degrees and Au.Au contacts in the range 2.9585(7)-3.0505(14) Å. These cations are linked into centrosymmetric dimers through two short Au.Au [2.9585(7), 3.0919(9) Å] contacts. The gold atoms of the dimer form a six-membered ring with a chair conformation.

MGR COMPLIANCE PROGRAM GUIDANCE PACKAGE FOR RADIATION PROTECTION EQUIPMENT, INSTRUMENTATION, AND FACILITIES

International Nuclear Information System (INIS)

2000-01-01

This Compliance Program Guidance Package identifies the regulatory guidance and industry codes and standards addressing radiation protection equipment, instrumentation, and support facilities considered to be appropriate for radiation protection at the Monitored Geologic Repository (MGR). Included are considerations relevant to radiation monitoring instruments, calibration, contamination control and decontamination, respiratory protection equipment, and general radiation protection facilities. The scope of this Guidance Package does not include design guidance relevant to criticality monitoring, area radiation monitoring, effluent monitoring, and airborne radioactivity monitoring systems since they are considered to be the topics of specific design and construction requirements (i.e., ''fixed'' or ''built-in'' systems). This Guidance Package does not address radiation protection design issues; it addresses the selection and calibration of radiation monitoring instrumentation to the extent that the guidance is relevant to the operational radiation protection program. Radon and radon progeny monitoring instrumentation is not included in the Guidance Package since such naturally occurring radioactive materials do not fall within the NRC's jurisdiction at the MGR

MGR External Events Hazards Analysis

International Nuclear Information System (INIS)

Booth, L.

1999-01-01

The purpose and objective of this analysis is to apply an external events Hazards Analysis (HA) to the License Application Design Selection Enhanced Design Alternative 11 [(LADS EDA II design (Reference 8.32))]. The output of the HA is called a Hazards List (HL). This analysis supersedes the external hazards portion of Rev. 00 of the PHA (Reference 8.1). The PHA for internal events will also be updated to the LADS EDA II design but under a separate analysis. Like the PHA methodology, the HA methodology provides a systematic method to identify potential hazards during the 100-year Monitored Geologic Repository (MGR) operating period updated to reflect the EDA II design. The resulting events on the HL are candidates that may have potential radiological consequences as determined during Design Basis Events (DBEs) analyses. Therefore, the HL that results from this analysis will undergo further screening and analysis based on the criteria that apply during the performance of DBE analyses

Development of GT-MGR plant power conversion unit design

International Nuclear Information System (INIS)

Kostin, V.I.; Kodochigov, N.G.; Belov, S.E.; Vasyaev, A.V.; Golovko, V.F.; Shenoj, A.

2007-01-01

The General Atomic Company (USA) and the Pilot Design Bureau for Machine-Building (Russia) are involved in the efforts to design the GT-MGR modular helium cooled reactor and the energy conversion unit with the direct gas turbine cycle. The reactor capacity is equal to 600 MW, it is cooled by helium under 7 MPa pressure. The energy conversion unit consists of a gas turbine, a recuperator, preliminary and intermediate coolers, a generator. The turbine shaft rotation frequency is equal to 4400 rotation/minute. One analyzed the alternate designs of the energy conversion unit to choose its configuration [ru

Long-range energy transfer in self-assembled quantum dot-DNA cascades

Science.gov (United States)

Goodman, Samuel M.; Siu, Albert; Singh, Vivek; Nagpal, Prashant

2015-11-01

The size-dependent energy bandgaps of semiconductor nanocrystals or quantum dots (QDs) can be utilized in converting broadband incident radiation efficiently into electric current by cascade energy transfer (ET) between layers of different sized quantum dots, followed by charge dissociation and transport in the bottom layer. Self-assembling such cascade structures with angstrom-scale spatial precision is important for building realistic devices, and DNA-based QD self-assembly can provide an important alternative. Here we show long-range Dexter energy transfer in QD-DNA self-assembled single constructs and ensemble devices. Using photoluminescence, scanning tunneling spectroscopy, current-sensing AFM measurements in single QD-DNA cascade constructs, and temperature-dependent ensemble devices using TiO2 nanotubes, we show that Dexter energy transfer, likely mediated by the exciton-shelves formed in these QD-DNA self-assembled structures, can be used for efficient transport of energy across QD-DNA thin films.The size-dependent energy bandgaps of semiconductor nanocrystals or quantum dots (QDs) can be utilized in converting broadband incident radiation efficiently into electric current by cascade energy transfer (ET) between layers of different sized quantum dots, followed by charge dissociation and transport in the bottom layer. Self-assembling such cascade structures with angstrom-scale spatial precision is important for building realistic devices, and DNA-based QD self-assembly can provide an important alternative. Here we show long-range Dexter energy transfer in QD-DNA self-assembled single constructs and ensemble devices. Using photoluminescence, scanning tunneling spectroscopy, current-sensing AFM measurements in single QD-DNA cascade constructs, and temperature-dependent ensemble devices using TiO2 nanotubes, we show that Dexter energy transfer, likely mediated by the exciton-shelves formed in these QD-DNA self-assembled structures, can be used for efficient

Effect of Promoter Region Mutations and mgrA Overexpression on Transcription of norA, Which Encodes a Staphylococcus aureus Multidrug Efflux Transporter

OpenAIRE

Kaatz, Glenn W.; Thyagarajan, Rama V.; Seo, Susan M.

2005-01-01

NorA is a Staphylococcus aureus multidrug transporter that confers resistance to structurally distinct compounds. The MgrA global regulatory protein is reported to augment norA expression when mgrA is overexpressed from an undefined plasmid-based promoter. Further details about norA regulatory mechanisms are scant. A chromosomal norA::lacZ transcriptional fusion was constructed in different S. aureus strains, and allele replacement was used to define the relevance of promoter region sequences...

Three-Dimensional Heat Transfer Analysis of Metal Fasteners in Roofing Assemblies

Directory of Open Access Journals (Sweden)

Manan Singh

2016-11-01

Full Text Available Heat transfer analysis was performed on typical roofing assemblies using HEAT3, a three-dimensional heat transfer analysis software. The difference in heat transferred through the roofing assemblies considered is compared between two cases—without any steel fasteners and with steel fasteners. In the latter case, the metal roofing fasteners were arranged as per Factor Mutual Global (FMG approvals, in the field, perimeter, and corner zones of the roof. The temperature conditions used for the analysis represented summer and winter conditions for three separate Climate Zones (CZ namely Climate Zone 2 or CZ2 represented by Orlando, FL; CZ3 represented by Atlanta, GA; and CZ6 zone represented by St. Paul, MN. In all the climatic conditions, higher energy transfer was observed with increase in the number of metal fasteners attributed to high thermal conductivity of metals as compared to the insulation and other materials used in the roofing assembly. This difference in heat loss was also quantified in the form of percentage change in the overall or effective insulation of the roofing assembly for better understanding of the practical aspects. Besides, a comparison of 2D heat transfer analysis (using THERM software and 3D analysis using HEAT3 is also discussed proving the relevance of 3D over 2D heat transfer analysis.

RADIATION ACCESS ZONE AND VENTILATION CONFINEMENT ZONE CRITERIA FOR THE MGR SURFACE FACILITIES

International Nuclear Information System (INIS)

D. A. Padula

2000-01-01

The objectives of this technical report are to: (1) Establish the criteria for Radiation Access Zone (RAZ) designation. (2) Establish the criteria for the Ventilation Confinement Zone (VCZ) designation. The scope will be to formulate the RAZ and VCZ zoning designation for the Monitored Geologic Repository (MGR) surface facilities and to apply the zoning designations to the current Waste Handling Building (WHB), Waste Treatment Building (WTB), and Carrier Preparation Building (CPB) configurations

Exciplex formation and energy transfer in a self-assembled metal-organic hybrid system.

Science.gov (United States)

Haldar, Ritesh; Rao, K Venkata; George, Subi J; Maji, Tapas Kumar

2012-05-07

Exciting assemblies: A metal-organic self-assembly of pyrenebutyric acid (PBA), 1,10-phenanthroline (o-phen), and Mg(II) shows solid-state fluorescence originating from a 1:1 PBA-o-phen exciplex. This exciplex fluorescence is sensitized by another residual PBA chromophore through an excited-state energy-transfer process. The solvent polarity modulates the self-assembly and the corresponding exciplex as well as the energy transfer, resulting in tunable emission of the hybrid (see figure). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Device for transferring fast nuclear reactor fuel assemblies

International Nuclear Information System (INIS)

Plagnard, Andre.

1982-01-01

The description is given of a device for transferring fuel assemblies between a storage position near the reactor vessel and a position where the irradiated assemblies are evacuated and the provision of new assemblies for the reactor. This device can be dismantled and is movable as a whole for its successive use on several reactors and includes: - a platform mounted so as to rotate on a support made to rest on the structure of the reactor, the platform having at least one opening then being horizontal and mobile about a vertical axis to bring the opening successively in position with vertical wells giving access to the storage and evacuation positions of the assemblies provided in the reactor structure, - at least one hopper that can contain one assembly in a vertical position, located on the upper surface of the platform around the opening provided in it and fitted with a winch for the vertical moving of the assemblies inside the wells and the hopper, when these follow each other by rotation of the platform, - at least one connecting device carried on the platform for connecting the hopper and wells when these are in line [fr

Graphene–cyclodextrin–cytochrome c layered assembly with improved electron transfer rate and high supramolecular recognition capability

Energy Technology Data Exchange (ETDEWEB)

Gong, Cheng-Bin; Guo, Cong-Cong; Jiang, Dan; Tang, Qian, E-mail: qiantang@swu.edu.cn; Liu, Chang-Hua; Ma, Xue-Bing

2014-06-01

This study aimed to develop a new graphene-based layered assembly, named graphene–cyclodextrin–cytochrome c with improved electron transfer rate. This assembly has combined high conductivity of graphene nanosheets (GNs), selectively binding properties and electronegativity of cyclodextrins (CDs), as well as electropositivity of cytochrome c (Cyt c). This assembly can also mimic the confined environments of the intermembrane space of mitochondria. A β-cyclodextrin (β-CD) functionalized GN (GN–CD) assembly was initially prepared by a simple wet-chemical strategy, i.e., in situ thermal reduction of graphene oxide with hydrazine hydrate in the presence of β-CD. Cyt c was then intercalated to the GN–CD assembly to form a layered self-assembled structure, GN–CD–Cyt c, through electrostatic interaction. Compared with GNs and GN–CD, GN–CD–Cyt c assembly displayed improved electron transfer rate and high supramolecular recognition capability toward six probe molecules. - Highlights: • A new tertiary layered assembly named GN–CD–Cyt c was prepared. • Compared with GNs and GN–CD, GN–CD–Cyt c shows improved electron transfer rate. • GN–CD–Cyt c displays high supramolecular recognition capability.

Graphene–cyclodextrin–cytochrome c layered assembly with improved electron transfer rate and high supramolecular recognition capability

International Nuclear Information System (INIS)

Gong, Cheng-Bin; Guo, Cong-Cong; Jiang, Dan; Tang, Qian; Liu, Chang-Hua; Ma, Xue-Bing

2014-01-01

This study aimed to develop a new graphene-based layered assembly, named graphene–cyclodextrin–cytochrome c with improved electron transfer rate. This assembly has combined high conductivity of graphene nanosheets (GNs), selectively binding properties and electronegativity of cyclodextrins (CDs), as well as electropositivity of cytochrome c (Cyt c). This assembly can also mimic the confined environments of the intermembrane space of mitochondria. A β-cyclodextrin (β-CD) functionalized GN (GN–CD) assembly was initially prepared by a simple wet-chemical strategy, i.e., in situ thermal reduction of graphene oxide with hydrazine hydrate in the presence of β-CD. Cyt c was then intercalated to the GN–CD assembly to form a layered self-assembled structure, GN–CD–Cyt c, through electrostatic interaction. Compared with GNs and GN–CD, GN–CD–Cyt c assembly displayed improved electron transfer rate and high supramolecular recognition capability toward six probe molecules. - Highlights: • A new tertiary layered assembly named GN–CD–Cyt c was prepared. • Compared with GNs and GN–CD, GN–CD–Cyt c shows improved electron transfer rate. • GN–CD–Cyt c displays high supramolecular recognition capability

Role of Achiral Nucleobases in Multicomponent Chiral Self-Assembly: Purine-Triggered Helix and Chirality Transfer.

Science.gov (United States)

Deng, Ming; Zhang, Li; Jiang, Yuqian; Liu, Minghua

2016-11-21

Chiral self-assembly is a basic process in biological systems, where many chiral biomolecules such as amino acids and sugars play important roles. Achiral nucleobases usually covalently bond to saccharides and play a significant role in the formation of the double helix structure. However, it remains unclear how the achiral nucleobases can function in chiral self-assembly without the sugar modification. Herein, we have clarified that purine nucleobases could trigger N-(9-fluorenylmethox-ycarbonyl) (Fmoc)-protected glutamic acid to self-assemble into helical nanostructures. Moreover, the helical nanostructure could serve as a matrix and transfer the chirality to an achiral fluorescence probe, thioflavin T (ThT). Upon chirality transfer, the ThT showed not only supramolecular chirality but also circular polarized fluorescence (CPL). Without the nucleobase, the self-assembly processes cannot happen, thus providing an example where achiral molecules played an essential role in the expression and transfer of the chirality. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhancement of heat transfer in HPLWR fuel assemblies

International Nuclear Information System (INIS)

Bastron, A.; Hofmeister, J.; Meyer, L.; Schulenberg, T.

2005-01-01

A study on different methods for enhancement of heat transfer in fuel assemblies for a High Performance Light Water Reactor has been performed to indicate the potential for a further increase of core outlet temperature at given cladding temperatures, or for reduction of peak cladding temperatures at the envisaged core outlet temperature. As a result, the introduction of an artificial surface roughness or the use of a staircase type grid spacer should increase the heat transfer coefficient of the coolant at the cladding surface by more than a factor of two, which will reduce the peak cladding temperature by at least 50 degC. The paper provides further details for realization of these measures. (author)

Archive of Geosample Data and Information from the Oregon State University (OSU) College of Earth, Ocean and Atmospheric Sciences (CEOAS) Marine Geology Repository (MGR)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Oregon State University Marine Geology Repository (OSU-MGR) is a partner in the Index to Marine and Lacustrine Geological Samples (IMLGS) database, contributing...

Graphene-cyclodextrin-cytochrome c layered assembly with improved electron transfer rate and high supramolecular recognition capability.

Science.gov (United States)

Gong, Cheng-Bin; Guo, Cong-Cong; Jiang, Dan; Tang, Qian; Liu, Chang-Hua; Ma, Xue-Bing

2014-06-01

This study aimed to develop a new graphene-based layered assembly, named graphene-cyclodextrin-cytochrome c with improved electron transfer rate. This assembly has combined high conductivity of graphene nanosheets (GNs), selectively binding properties and electronegativity of cyclodextrins (CDs), as well as electropositivity of cytochrome c (Cyt c). This assembly can also mimic the confined environments of the intermembrane space of mitochondria. A β-cyclodextrin (β-CD) functionalized GN (GN-CD) assembly was initially prepared by a simple wet-chemical strategy, i.e., in situ thermal reduction of graphene oxide with hydrazine hydrate in the presence of β-CD. Cyt c was then intercalated to the GN-CD assembly to form a layered self-assembled structure, GN-CD-Cyt c, through electrostatic interaction. Compared with GNs and GN-CD, GN-CD-Cyt c assembly displayed improved electron transfer rate and high supramolecular recognition capability toward six probe molecules. Copyright © 2014 Elsevier B.V. All rights reserved.

About calculation results of heat transfer in the fuel assembly clusters cooled by water with supercritical parameters

International Nuclear Information System (INIS)

Grabezhnaya, V.A.

2008-01-01

Paper reviews the numerical investigation into the heat transfer in the supercritical water cooled fuel assemblies on the basis of the various commercial codes. The turbulence available models specified in the codes describe adequately the experimental data in tubes within the range of flow temperatures away from the pseudocritical point, as well as under high mass velocities. There are k-ε type turbulence models that show qualitatively the local acceleration (slowdown) of the heat transfer in tubes, but they fail to describe the mentioned phenomena quantitatively. To determine the effect of grid spacers on the suppression of the heat transfer local slowdown and on the heat transfer acceleration in fuel assemblies and to ensure more accurate calculation of the fuel element cladding maximum temperature one should perform a number of the experiments making use of the fuel assembly models [ru

Direct Electron Transfer of Enzymes in a Biologically Assembled Conductive Nanomesh Enzyme Platform.

Science.gov (United States)

Lee, Seung-Woo; Lee, Ki-Young; Song, Yong-Won; Choi, Won Kook; Chang, Joonyeon; Yi, Hyunjung

2016-02-24

Nondestructive assembly of a nanostructured enzyme platform is developed in combination of the specific biomolecular attraction and electrostatic coupling for highly efficient direct electron transfer (DET) of enzymes with unprecedented applicability and versatility. The biologically assembled conductive nanomesh enzyme platform enables DET-based flexible integrated biosensors and DET of eight different enzyme with various catalytic activities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solution of the conjugated heat transfer problem for the fuel elements assemblies

International Nuclear Information System (INIS)

Golba, V.S.; Ivanenko, I.J.; Zinina, G.A.

1997-01-01

The paper presents the assemblies conjugated heat conductivity problem calculation and experimental method. The method is based on the temperature superposition modified concept and subchannel method and allows to predict the fuel elements surface temperatures with availability of fuel elements inside structure of any complication caused by technological and working defects and with availability of depositions with low heat conductivity on the fuel elements surfaces. According to the method developed the partial solutions of the heat conductivity equation at the heat removal boundaries (solid-liquid) are found separately for the fuel elements and for the liquid. The heat conductivity equation partial solutions for the fuel elements are predicted by calculations. The coolant heat conductivity equation partial solution ('influence functions') data massif is obtained in present work experimentally in the fuel assembly model consists of 7 tube bundle of fuel elements imitators placed in right grating with relative grating step equal to 1.1 and cooled by eutectic alloy Pb-Bi. It is shown that 'subchannel prediction method' decreases the crosswise heat transfer in comparison with crosswise heat transfer, when the fuel element inside structure is taken into account. Also in the paper it is shown that it is possible to realize the assembly temperature prediction method suggested without carrying out the experiments in the assembly's model in order to get the external problem influence functions'. (author)

{beta}-Carotene to bacteriochlorophyll c energy transfer in self-assembled aggregates mimicking chlorosomes

Energy Technology Data Exchange (ETDEWEB)

Alster, J. [Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Praha (Czech Republic); Polivka, T. [Institute of Physical Biology, University of South Bohemia, Zamek 136, 373 33 Nove Hrady (Czech Republic); Biology Centre, Academy of Sciences of the Czech Republic, Branisovska 31, 370 05 Ceske Budejovice (Czech Republic); Arellano, J.B. [Instituto de Recursos Naturales y Agrobiologia de Salamanca (IRNASA-CSIC), Apdo. 257, 37071 Salamanca (Spain); Chabera, P. [Institute of Physical Biology, University of South Bohemia, Zamek 136, 373 33 Nove Hrady (Czech Republic); Vacha, F. [Institute of Physical Biology, University of South Bohemia, Zamek 136, 373 33 Nove Hrady (Czech Republic); Biology Centre, Academy of Sciences of the Czech Republic, Branisovska 31, 370 05 Ceske Budejovice (Czech Republic); Psencik, J., E-mail: psencik@karlov.mff.cuni.cz [Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Praha (Czech Republic); Institute of Physical Biology, University of South Bohemia, Zamek 136, 373 33 Nove Hrady (Czech Republic)

2010-07-19

Carotenoids are together with bacteriochlorophylls important constituents of chlorosomes, the light-harvesting antennae of green photosynthetic bacteria. Majority of bacteriochlorophyll molecules form self-assembling aggregates inside the chlorosomes. Aggregates of bacteriochlorophylls with optical properties similar to those of chlorosomes can also be prepared in non-polar organic solvents or in aqueous environments when a suitable non-polar molecule is added. In this work, the ability of {beta}-carotene to induce aggregation of bacteriochlorophyll c in aqueous buffer was studied. Excitation relaxation and energy transfer in the carotenoid-bacteriochlorophyll assemblies were measured using femtosecond and nanosecond transient absorption spectroscopy. A fast, {approx}100-fs energy transfer from the S{sub 2} state of {beta}-carotene to bacteriochlorophyll c was revealed, while no evidence for significant energy transfer from the S{sub 1} state was found. Picosecond formation of the carotenoid triplet state (T{sub 1}) was observed, which was likely generated by singlet homo-fission from the S{sub 1} state of {beta}-carotene.

IHF-independent assembly of the Tn10 strand transfer transpososome: implications for inhibition of disintegration

OpenAIRE

Stewart, Barry J.; Wardle, Simon J.; Haniford, David B.

2002-01-01

The frequency of DNA transposition in transposition systems that employ a strand transfer step may be significantly affected by the occurrence of a disintegration reaction, a reaction that reverses the strand transfer event. We have asked whether disintegration occurs in the Tn10 transposition system. We show that disintegration substrates (substrates constituting one half of the strand transfer product) are assembled into a transpososome that mimics the strand transfer intermediate. This str...

Numerical investigation of a heat transfer within the prismatic fuel assembly of a very high temperature reactor

International Nuclear Information System (INIS)

Tak, Nam-il; Kim, Min-Hwan; Lee, Won Jae

2008-01-01

The complex geometry of the hexagonal fuel blocks of the prismatic fuel assembly in a very high temperature reactor (VHTR) hinders accurate evaluations of the temperature profile within the fuel assembly without elaborate numerical calculations. Therefore, simplified models such as a unit cell model have been widely applied for the analyses and designs of prismatic VHTRs since they have been considered as effective approaches reducing the computational efforts. In a prismatic VHTR, however, the simplified models cannot consider a heat transfer within a fuel assembly as well as a coolant flow through a bypass gap between the fuel assemblies, which may significantly affect the maximum fuel temperature. In this paper, a three-dimensional computational fluid dynamics (CFD) analysis has been carried out on a typical fuel assembly of a prismatic VHTR. Thermal behaviours and heat transfer within the fuel assembly are intensively investigated using the CFD solutions. In addition, the accuracy of the unit cell approach is assessed against the CFD solutions. Two example situations are illustrated to demonstrate the deficiency of the unit cell model caused by neglecting the effects of the bypass gap flow and the radial power distribution within the fuel assembly

Flexture plate motion-transfer mechanism, beam-splitter assembly, and interferometer incorporating the same

Energy Technology Data Exchange (ETDEWEB)

Carangelo, Robert M. (Glastonbury, CT); Dettori, Mark D. (Farmington, CT); Grigely, Lawrence J. (South Windsor, CT); Murray, Terence C. (Winchester, MA); Solomon, Peter R. (West Hartford, CT); Van Dine, C. Peter (Bolton, CT); Wright, David D. (Vershire, VT)

1996-01-01

A multiplicity of one-piece flexure plates are assembled in pairs to provide a support system on which a retroreflector may be mounted for reciprocal motion. Combined with balance bodies, the flexure plates provide a support system having portions that are dynamically and statically balanced with one another, irrespective of orientation, so as to thereby immunize the unit against extraneous forces. The motion transfer assembly is especially adapted for use to support a moving retroreflector in a two-arm interferometer that may further include a beamsplitter assembly constructed from a one-piece, integrally formed body, the body having convergent, optically flat planar surfaces of specular reflectance, and means for adjustably mounting a beamsplitter therein. The spectrometer is of modular construction, and employs an integrated clocking sub-assembly as well as a light-weight voice-coil motor.

Construction of energy transfer pathways self-assembled from DNA-templated stacks of anthracene.

Science.gov (United States)

Iwaura, Rika; Yui, Hiroharu; Someya, Yuu; Ohnishi-Kameyama, Mayumi

2014-01-05

We describe optical properties of anthracene stacks formed from single-component self-assembly of thymidylic acid-appended anthracene 2,6-bis[5-(3'-thymidylic acid)pentyloxy] anthracene (TACT) and the binary self-assembly of TACT and complementary 20-meric oligoadenylic acid (TACT/dA20) in an aqueous buffer. UV-Vis and emission spectra for the single-component self-assembly of TACT and the binary self-assembly of TACT/dA20 were very consistent with stacked acene moieties in both self-assemblies. Interestingly, time-resolved fluorescence spectra from anthracene stacks exhibited very different features of the single-component and binary self-assemblies. In the single-component self-assembly of TACT, a dynamic Stokes shift (DSS) and relatively short fluorescence lifetime (τ=0.35ns) observed at around 450nm suggested that the anthracene moieties were flexible. Moreover, a broad emission at 530nm suggested the formation of an excited dimer (excimer). In the binary self-assembly of TACT/dA20, we detected a broad, red-shifted emission component at 534nm with a lifetime (τ=0.4ns) shorter than that observed in the TACT single-component self-assembly. Combining these results with the emission spectrum of the binary self-assembly of TACT/5'-HEX dA20, we concluded that the energy transfer pathway was constructed by columnar anthracene stacks formed from the DNA-templated self-assembly of TACT. Copyright © 2013 Elsevier B.V. All rights reserved.

Reversible assembly of protein-DNA nanostructures triggered by mediated electron transfer

International Nuclear Information System (INIS)

Vogt, Stephan; Wenderhold-Reeb, Sabine; Nöll, Gilbert

2017-01-01

Stable protein-DNA nanostructures have been assembled by reconstitution of the multi-ligand binding flavoprotein dodecin on top of flavin-terminated dsDNA monolayers on gold electrodes. These structures could be disassembled by electrochemical flavin reduction via mediated electron transfer. For this purpose a negative potential was applied at the Au working electrode in the presence of the redox mediator bis-(ammoniumethyl)-4,4′-bipyridinium tetrabromide. The stepwise formation of the flavin-terminated dsDNA monolayers as well as the binding and electrochemically triggered release of apododecin were monitored by surface plasmon resonance (SPR) and quartz crystal microbalance (QCM) measurements. The assembly and disassembly of the protein-DNA nanostructures were fully reversible processes, which could be carried out multiple times at the same flavin-dsDNA modified surface. When a negative potential was applied in the absence of a redox mediator apododecin could not be released, i.e. direct electron transfer was not possible. As alternative redox mediators also methylene blue and phenosafranine were studied, but in the presence of these molecules apododecin was released without applying a potential, probably because the tricyclic aromatic compounds are able to replace the flavins at the binding sites.

Transfer-Free Growth of Multilayer Graphene Using Self-Assembled Monolayers.

Science.gov (United States)

Yang, Gwangseok; Kim, Hong-Yeol; Jang, Soohwan; Kim, Jihyun

2016-10-12

Large-area graphene needs to be directly synthesized on the desired substrates without using a transfer process so that it can easily be used in industrial applications. However, the development of a direct method for graphene growth on an arbitrary substrate remains challenging. Here, we demonstrate a bottom-up and transfer-free growth method for preparing multilayer graphene using a self-assembled monolayer (trimethoxy phenylsilane) as the carbon source. Graphene was directly grown on various substrates such as SiO 2 /Si, quartz, GaN, and textured Si by a simple thermal annealing process employing catalytic metal encapsulation. To determine the optimal growth conditions, experimental parameters such as the choice of catalytic metal, growth temperatures, and gas flow rate were investigated. The optical transmittance at 550 nm and the sheet resistance of the prepared transfer-free graphene are 84.3% and 3500 Ω/□, respectively. The synthesized graphene samples were fabricated into chemical sensors. High and fast responses to both NO 2 and NH 3 gas molecules were observed. The transfer-free graphene growth method proposed in this study is highly compatible with previously established fabrication systems, thereby opening up new possibilities for using graphene in versatile applications.

Transfer of sulfur from IscS to IscU during Fe/S cluster assembly.

Science.gov (United States)

Urbina, H D; Silberg, J J; Hoff, K G; Vickery, L E

2001-11-30

The cysteine desulfurase enzymes NifS and IscS provide sulfur for the biosynthesis of Fe/S proteins. NifU and IscU have been proposed to serve as template or scaffold proteins in the initial Fe/S cluster assembly events, but the mechanism of sulfur transfer from NifS or IscS to NifU or IscU has not been elucidated. We have employed [(35)S]cysteine radiotracer studies to monitor sulfur transfer between IscS and IscU from Escherichia coli and have used direct binding measurements to investigate interactions between the proteins. IscS catalyzed transfer of (35)S from [(35)S]cysteine to IscU in the absence of additional thiol reagents, suggesting that transfer can occur directly and without involvement of an intermediate carrier. Surface plasmon resonance studies and isothermal titration calorimetry measurements further revealed that IscU binds to IscS with high affinity (K(d) approximately 2 microm) in support of a direct transfer mechanism. Transfer was inhibited by treatment of IscU with iodoacetamide, and (35)S was released by reducing reagents, suggesting that transfer of persulfide sulfur occurs to cysteinyl groups of IscU. A deletion mutant of IscS lacking C-terminal residues 376-413 (IscSDelta376-413) displayed cysteine desulfurase activity similar to the full-length protein but exhibited lower binding affinity for IscU, decreased ability to transfer (35)S to IscU, and reduced activity in assays of Fe/S cluster assembly on IscU. The findings with IscSDelta376-413 provide additional support for a mechanism of sulfur transfer involving a direct interaction between IscS and IscU and suggest that the C-terminal region of IscS may be important for binding IscU.

Multihospital Occurrence of Pan-Resistant Klebsiella pneumoniae Sequence Type 147 with an ISEcp1-Directed blaOXA-181 Insertion in the mgrB Gene in the United Arab Emirates.

Science.gov (United States)

Sonnevend, Ágnes; Ghazawi, Akela; Hashmey, Rayhan; Haidermota, Aliasgher; Girgis, Safinaz; Alfaresi, Mubarak; Omar, Mohammed; Paterson, David L; Zowawi, Hosam M; Pál, Tibor

2017-07-01

The emergence of pan-resistant Klebsiella pneumoniae strains is an increasing concern. In the present study, we describe a cluster of 9 pan-resistant K. pneumoniae sequence type 147 (ST147) isolates encountered in 4 patients over nearly 1 year in 3 hospitals of the United Arab Emirates (UAE). The isolates exhibited highly similar genotypes. All produced chromosomally encoded OXA-181, and the majority also produced the NDM-5 carbapenemase. As with the previously described single isolate from the UAE, MS6671, the mgrB was disrupted by a functional, IS Ecp1 -driven bla OXA-181 insertion causing resistance to carbapenems. The mutation was successfully complemented with an intact mgrB gene, indicating that it was responsible for colistin resistance. bla NDM-5 was located within a resistance island of an approximately 100-kb IncFII plasmid carrying ermB , mph (A), bla TEM-1B , rmtB , bla NDM-5 , sul1 , aadA2 , and dfrA12 resistance genes. Sequencing this plasmid (pABC143-NDM) revealed that its backbone was nearly identical to that of plasmid pMS6671E from which several resistance genes, including bla NDM-5 , had been deleted. More extensive similarities of the backbone and the resistance island were found between pABC143C-NDM and the bla NDM-5 -carrying IncFII plasmids of two K. pneumoniae ST147 isolates from South Korea, one of which was colistin resistant, and both also produced OXA-181. Notably, one of these strains was isolated from a patient transferred from the UAE. Our data show that this pan-resistant clone has an alarming capacity to maintain itself over an extended period of time and is even likely to be transmitted internationally. Copyright © 2017 American Society for Microbiology.

Transfer hood for handling fuel assemblies in nuclear reactors and especially fast reactors

International Nuclear Information System (INIS)

Aubert, M.; Merland, D.; Renaux, C.

1975-01-01

A description is given of a hood for transferring fuel assemblies between two or more separate guide ramps inclined to the vertical at the same angle of slope and extending respectively through a first passage into the reactor vessel and through a second passage into a fuel-assembly storage chamber. The hood comprises at least one shielded duct joined to a flanged rotating portion which is so arranged that the open lower end of the shielded duct is positioned in the line of extension of one guide ramp and then the other as a result of displacement of the rotating portion

Transfer printing techniques for materials assembly and micro/nanodevice fabrication.

Science.gov (United States)

Carlson, Andrew; Bowen, Audrey M; Huang, Yonggang; Nuzzo, Ralph G; Rogers, John A

2012-10-09

Transfer printing represents a set of techniques for deterministic assembly of micro-and nanomaterials into spatially organized, functional arrangements with two and three-dimensional layouts. Such processes provide versatile routes not only to test structures and vehicles for scientific studies but also to high-performance, heterogeneously integrated functional systems, including those in flexible electronics, three-dimensional and/or curvilinear optoelectronics, and bio-integrated sensing and therapeutic devices. This article summarizes recent advances in a variety of transfer printing techniques, ranging from the mechanics and materials aspects that govern their operation to engineering features of their use in systems with varying levels of complexity. A concluding section presents perspectives on opportunities for basic and applied research, and on emerging use of these methods in high throughput, industrial-scale manufacturing. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Natural convection heat transfer within horizontal spent nuclear fuel assemblies

International Nuclear Information System (INIS)

Canaan, R.E.

1995-12-01

Natural convection heat transfer is experimentally investigated in an enclosed horizontal rod bundle, which characterizes a spent nuclear fuel assembly during dry storage and/or transport conditions. The basic test section consists of a square array of sixty-four stainless steel tubular heaters enclosed within a water-cooled rectangular copper heat exchanger. The heaters are supplied with a uniform power generation per unit length while the surrounding enclosure is maintained at a uniform temperature. The test section resides within a vacuum/pressure chamber in order to subject the assembly to a range of pressure statepoints and various backfill gases. The objective of this experimental study is to obtain convection correlations which can be used in order to easily incorporate convective effects into analytical models of horizontal spent fuel systems, and also to investigate the physical nature of natural convection in enclosed horizontal rod bundles in general. The resulting data consist of: (1) measured temperatures within the assembly as a function of power, pressure, and backfill gas; (2) the relative radiative contribution for the range of observed temperatures; (3) correlations of convective Nusselt number and Rayleigh number for the rod bundle as a whole; and (4) correlations of convective Nusselt number as a function of Rayleigh number for individual rods within the array

A Novel Pentadentate Coordination Mode for the Carbonato Bridge: Synthesis, Crystal Structure, and Magnetic Behavior of (&mgr;(3)-CO(3))[Ni(3)(Medpt)(3)(NCS)(4)], a New Trinuclear Nickel(II) Carbonato-Bridged Complex with Strong Antiferromagnetic Coupling.

Science.gov (United States)

Escuer, Albert; Vicente, Ramon; Kumar, Sujit B.; Solans, Xavier; Font-Bardía, Mercé; Caneschi, Andrea

1996-05-22

The trinuclear complex (&mgr;(3)-CO(3))[Ni(3)(Medpt)(3)(NCS)(4)] was obtained by reaction of basic solutions of nickel(II), Medpt (bis(3aminopropyl)methylamine) and thiocyanate ligand with atmospheric CO(2) or by simple reaction with carbonate anion. (&mgr;(3)-CO(3))[Ni(3)(Medpt)(3)(NCS)(4)] crystallizes in the triclinic system, space group P&onemacr;, with a = 12.107(5) Å, b = 12.535(7) Å, c = 16.169(9) Å, alpha = 102.69(5) degrees, beta = 92.91(5) degrees, gamma = 118.01(4) degrees, Z = 2, and R = 0.043. The three nickel atoms are asymmetrically bridged by one pentadentate carbonato ligand, which shows a novel coordination mode. The (&mgr;(3)-CO(3))[Ni(3)(Medpt)(3)(NCS)(4)] compound shows a very strong antiferromagnetic coupling. Fit as irregular triangular arrangement gave J(1) = -88.4, J(2) = -57.7, and J(3) = -9.6 cm(-)(1), which is the strongest AF coupling observed to date for Ni(3) compounds. The magnetic behavior of the carbonato bridge is discussed.

Heterogeneous electron transfer kinetics and electrocatalytic behaviour of mixed self-assembled ferrocenes and SWCNT layers

CSIR Research Space (South Africa)

Nkosi, D

2010-01-01

Full Text Available The electron transfer dynamics and electrocatalytic behaviour of ferrocene-terminated self-assembled monolayers (SAMs), co-adsorbed with single-walled carbon nanotubes (SWCNTs) on a gold electrode, have been interrogated for the first time...

Uncanistered Spent Nuclear fuel Disposal Container System Description Document

International Nuclear Information System (INIS)

Pettit, N. E.

2001-01-01

The Uncanistered Spent Nuclear Fuel (SNF) Disposal Container System supports the confinement and isolation of waste within the Engineered Barrier System of the Monitored Geologic Repository (MGR). Disposal containers are loaded with intact uncanistered assemblies and/or individually canistered SNF assemblies and sealed in the surface waste handling facilities, transferred to the underground through the access drifts, and emplaced in emplacement drifts. The Uncanistered SNF Disposal Container provides long-term confinement of the commercial SNF placed inside, and withstands the loading, transfer, emplacement, and retrieval loads and environments. The Uncanistered SNF Disposal Container System provides containment of waste for a designated period of time, and limits radionuclide release. The disposal container maintains the waste in a designated configuration, withstands maximum handling and rockfall loads, limits the individual SNF assembly temperatures after emplacement, limits the introduction of moderator into the disposal container during the criticality control period, resists corrosion in the expected handling and repository environments, and provides containment of waste in the event of an accident

Methods of making membrane electrode assemblies

Science.gov (United States)

Kim, Yu Seung; Lee, Kwan -Soo; Rockward, Tommy Q. T.

2015-07-28

Method of making a membrane electrode assembly comprising: providing a membrane comprising a perfluorinated sulfonic acid; providing a first transfer substrate; applying to a surface of the first transfer substrate a first ink, said first ink comprising an ionomer and a catalyst; applying to the first ink a suitable non-aqueous swelling agent; forming an assembly comprising: the membrane; and the first transfer substrate, wherein the surface of the first transfer substrate comprising the first ink and the non-aqueous swelling agent is disposed upon one surface of the membrane; and heating the assembly at a temperature of 150.degree. C. or less and at a pressure of from about 250 kPa to about 3000 kPa or less for a time suitable to allow substantially complete transfer of the first ink and the second ink to the membrane; and cooling the assembly to room temperature and removing the first transfer substrate and the second transfer substrate.

Tunable self-assembled spin chains of strongly interacting cold atoms for demonstration of reliable quantum state transfer

DEFF Research Database (Denmark)

Loft, N. J. S.; Marchukov, O. V.; Petrosyan, D.

2016-01-01

We have developed an efficient computational method to treat long, one-dimensional systems of strongly-interacting atoms forming self-assembled spin chains. Such systems can be used to realize many spin chain model Hamiltonians tunable by the external confining potential. As a concrete...... demonstration, we consider quantum state transfer in a Heisenberg spin chain and we show how to determine the confining potential in order to obtain nearly-perfect state transfer....

Heat transfer and friction characteristics of rotor-assembled strand heat exchanger studied by uniform design experiment

Directory of Open Access Journals (Sweden)

Yan Wei

2015-10-01

Full Text Available The uniform distribution and experimental design is employed to study the thermo-hydraulic characteristics of a heat exchanger, which consists of the rotor-assembled strands mounted in circular smooth tubes. The uniform distribution and experimental design parameters include multiple rotor parameters such as rotor diameters, rotor lead, and height of blade, with the aim of studying their influence on the PEC, that is, ( ( Nu z / Nu g / ( f g / f z 1 / 3 , which stands for the heat transfer and friction characteristics. The best matching schemes of rotor-assembled strand, which significantly improves PEC to 2.01, are given by the regression analysis of uniform distribution and experimental design table. The single-factor experiments are performed to compare a tube installed with different kinds of rotor-assembled strands with a smooth tube without any strands when the Reynolds number changes between 20,000 and 60,000. The experimental result is in good agreement with the result obtained by the regression analysis of uniform distribution and experimental design. It is shown that the rotor diameters play important role in the heat transfer, and the optimal PEC value is obtained under the case that the rotor diameter is 21 mm. The rotor lead also contributes to the improvement of heat transfer and its optimal value is 700 mm in this study. The Nusselt number, friction factor and PEC increase with the increase in blade height. It shows that the uniform distribution and experimental design is an efficient method to find out the optimal parameters.

Transfer of Skills Evaluation for Assembly and Maintenance Training

Directory of Open Access Journals (Sweden)

Peveri Matteo

2011-12-01

Full Text Available One of the research topics within the EU-project SKILLS1 was the training of Industrial Maintenance and Assembly (IMA tasks. The IMA demonstrator developed comprehends two different training platforms, one based on technologies of Virtual Reality (VR and the other one on Augmented Reality (AR. To qualify the efficiency of the developed training systems different studies have been conducted, followed by a final “Transfer of Skill” evaluation that has been performed by service technicians at the “SIDEL industrial training centre” in Parma. This evaluation included qualitative methods (feedback collection in questionnaires as well as quantitative methods (experiments with control groups. The results demonstrate that both platforms are useful and suitable training tools for IMA tasks, and that the AR training decreased the number of unsolved errors in the task.

COBRA-SFS predictions of single assembly spent fuel heat transfer data

International Nuclear Information System (INIS)

Lombardo, N.J.; Michener, T.E.; Wheeler, C.L.; Rector, D.R.

1986-04-01

The study reported here is one of several efforts to evaluate and qualify the COBRA-SFS computer code for use in spent fuel storage system thermal analysis. The ability of COBRA-SFS to predict the thermal response of two single assembly spent fuel heat transfer tests was investigated through comparisons of predictions with experimental test data. From these comparisons, conclusions regarding the computational treatment of the physical phenomena occurring within a storage system can be made. This objective was successfully accomplished as reasonable agreement between predictions and data were obtained for the 21 individual test cases of the two experiments

Ex-vessel nuclear fuel transfer system

International Nuclear Information System (INIS)

Wade, E.E.

1978-01-01

A system for transferring fuel assemblies between a fuel transfer area and a fuel storage area while the fuel assemblies remain completely submerged in a continuous body of coolant is described. A fuel transfer area filled with reactor coolant communicating with the reactor vessel below the reactor coolant level provides a transfer area for fuel assemblies in transit to and from the reactor vessel. A positioning mechanism comprising at least one rotatable plug disposed on a fuel transfer tank located outside the reactor vessel cooperates with either the fuel transfer area or the fuel storage area to position a fuel assembly in transit. When in position, a transporting mechanism cooperating with the positioning mechanism lifts or lowers a chosen fuel assembly. The transporting mechanism together with the positioning mechanism are capable of transferring a fuel assembly between the fuel transfer area and the fuel storage area

Highly active bidirectional electron transfer by a self-assembled electroactive reduced-graphene-oxide-hybridized biofilm.

Science.gov (United States)

Yong, Yang-Chun; Yu, Yang-Yang; Zhang, Xinhai; Song, Hao

2014-04-22

Low extracellular electron transfer performance is often a bottleneck in developing high-performance bioelectrochemical systems. Herein, we show that the self-assembly of graphene oxide and Shewanella oneidensis MR-1 formed an electroactive, reduced-graphene-oxide-hybridized, three-dimensional macroporous biofilm, which enabled highly efficient bidirectional electron transfers between Shewanella and electrodes owing to high biomass incorporation and enhanced direct contact-based extracellular electron transfer. This 3D electroactive biofilm delivered a 25-fold increase in the outward current (oxidation current, electron flux from bacteria to electrodes) and 74-fold increase in the inward current (reduction current, electron flux from electrodes to bacteria) over that of the naturally occurring biofilms. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

COXPRO-II: a computer program for calculating radiation and conduction heat transfer in irradiated fuel assemblies

International Nuclear Information System (INIS)

Rhodes, C.A.

1984-12-01

This report describes the computer program COXPRO-II, which was written for performing thermal analyses of irradiated fuel assemblies in a gaseous environment with no forced cooling. The heat transfer modes within the fuel pin bundle are radiation exchange among fuel pin surfaces and conduction by the stagnant gas. The array of parallel cylindrical fuel pins may be enclosed by a metal wrapper or shroud. Heat is dissipated from the outer surface of the fuel pin assembly by radiation and convection. Both equilateral triangle and square fuel pin arrays can be analyzed. Steady-state and unsteady-state conditions are included. Temperatures predicted by the COXPRO-II code have been validated by comparing them with experimental measurements. Temperature predictions compare favorably to temperature measurements in pressurized water reactor (PWR) and liquid-metal fast breeder reactor (LMFBR) simulated, electrically heated fuel assemblies. Also, temperature comparisons are made on an actual irradiated Fast-Flux Test Facility (FFTF) LMFBR fuel assembly

Methodology for verification of heat transfer crisis in the nuclear fuel assemblies

International Nuclear Information System (INIS)

Sharaevsky, I. G.; Sharaevskaya, E. I.; Domashev, E. D.; Arkhypov, A. P.; Kolochko, V. N.

2003-01-01

instability is remained unstudied practically. There are no up-to-date version of the TH codes considering possibility of these oscillation processes in the fuel assemblies beginning. In the paper in the context of the formulated problems the verification methodology for heat transfer crises and high frequency oscillations in heat release assemblies of WWER type units

Bearing assemblies, apparatuses, and motor assemblies using the same

Science.gov (United States)

Sexton, Timothy N.; Cooley, Craig H.; Knuteson, Cody W.

2015-12-29

Various embodiments of the invention relate to bearing assemblies, apparatuses and motor assemblies that include geometric features configured to impart a selected amount of heat transfer and/or hydrodynamic film formation. In an embodiment, a bearing assembly may include a plurality of superhard bearing pads distributed circumferentially about an axis. At least some of the plurality of superhard bearing pads may include a plurality of sub-superhard bearing elements defining a bearing surface. At least some of the plurality of sub-superhard bearing elements may be spaced from one another by one or more voids to impart a selected amount of heat transfer and hydrodynamic film formation thereon during operation. The bearing assembly may also include a support ring that carries the plurality of superhard bearing pads. In addition, at least a portion of the sub-superhard bearing elements may extend beyond the support ring.

Evolutionary novelty in gravity sensing through horizontal gene transfer and high-order protein assembly.

Directory of Open Access Journals (Sweden)

Tu Anh Nguyen

2018-04-01

Full Text Available Horizontal gene transfer (HGT can promote evolutionary adaptation by transforming a species' relationship to the environment. In most well-understood cases of HGT, acquired and donor functions appear to remain closely related. Thus, the degree to which HGT can lead to evolutionary novelties remains unclear. Mucorales fungi sense gravity through the sedimentation of vacuolar protein crystals. Here, we identify the octahedral crystal matrix protein (OCTIN. Phylogenetic analysis strongly supports acquisition of octin by HGT from bacteria. A bacterial OCTIN forms high-order periplasmic oligomers, and inter-molecular disulphide bonds are formed by both fungal and bacterial OCTINs, suggesting that they share elements of a conserved assembly mechanism. However, estimated sedimentation velocities preclude a gravity-sensing function for the bacterial structures. Together, our data suggest that HGT from bacteria into the Mucorales allowed a dramatic increase in assembly scale and emergence of the gravity-sensing function. We conclude that HGT can lead to evolutionary novelties that emerge depending on the physiological and cellular context of protein assembly.

Facilities of fuel transfer for nuclear reactors

International Nuclear Information System (INIS)

Wade, E.E.

1977-01-01

This invention relates to sodium cooled fast breeder reactors. It particularly concerns facilities for the transfer of fuel assemblies between the reactor core and a fuel transfer area. The installation is simple in construction and enables a relatively small vessel to be used. In greater detail, the invention includes a vessel with a head, fuel assemblies housed in this vessel, and an inlet and outlet for the coolant covering these fuel assemblies. The reactor has a fuel transfer area in communication with this vessel and gear inside the vessel for the transfer of these fuel assemblies. These facilities are borne by the vessel head and serve to transfer the fuel assemblies from the vessel to the transfer area; whilst leaving the fuel assemblies completely immersed in a continuous mass of coolant. A passageway is provided between the vessel and this transfer area for the fuel assemblies. Facilities are provided for closing off this passageway so that the inside of the reactor vessel may be isolated as desired from this fuel transfer area whilst the reactor is operating [fr

Modulation of Intracellular Quantum Dot to Fluorescent Protein Förster Resonance Energy Transfer via Customized Ligands and Spatial Control of Donor–Acceptor Assembly

Directory of Open Access Journals (Sweden)

Lauren D. Field

2015-12-01

Full Text Available Understanding how to controllably modulate the efficiency of energy transfer in Förster resonance energy transfer (FRET-based assemblies is critical to their implementation as sensing modalities. This is particularly true for sensing assemblies that are to be used as the basis for real time intracellular sensing of intracellular processes and events. We use a quantum dot (QD donor -mCherry acceptor platform that is engineered to self-assemble in situ wherein the protein acceptor is expressed via transient transfection and the QD donor is microinjected into the cell. QD-protein assembly is driven by metal-affinity interactions where a terminal polyhistidine tag on the protein binds to the QD surface. Using this system, we show the ability to modulate the efficiency of the donor–acceptor energy transfer process by controllably altering either the ligand coating on the QD surface or the precise location where the QD-protein assembly process occurs. Intracellularly, a short, zwitterionic ligand mediates more efficient FRET relative to longer ligand species that are based on the solubilizing polymer, poly(ethylene glycol. We further show that a greater FRET efficiency is achieved when the QD-protein assembly occurs free in the cytosol compared to when the mCherry acceptor is expressed tethered to the inner leaflet of the plasma membrane. In the latter case, the lower FRET efficiency is likely attributable to a lower expression level of the mCherry acceptor at the membrane combined with steric hindrance. Our work points to some of the design considerations that one must be mindful of when developing FRET-based sensing schemes for use in intracellular sensing.

Photoinduced Electron Transfer in Ordered Macromolecular Assemblies. Final report for May 1, 1988 - June 30, 2002

Energy Technology Data Exchange (ETDEWEB)

Jones, G.

2005-02-11

The final report describes studies over a 13 year period having to do with photoinduced electron transfer for active chromophores and redox agents, including assembly of the components in water soluble polymers or polypeptides. The findings include observation of long range charge separation and electron transport using laser phototransient spectroscopy. The systems targeted in these studies include peptide assemblies for which helical conformations and aggregation are documented. Oligomeric peptides modified with non-native redox active groups were also selected for investigation. Highly charged polymers or peptides were investigated as host agents that resemble proteins. The overall goal of these investigations focused on the design and characterization of systems capable of artificial photosynthesis.

Etchant-free graphene transfer using facile intercalation of alkanethiol self-assembled molecules at graphene/metal interfaces.

Science.gov (United States)

Ohtomo, Manabu; Sekine, Yoshiaki; Wang, Shengnan; Hibino, Hiroki; Yamamoto, Hideki

2016-06-02

We report a novel etchant-free transfer method of graphene using the intercalation of alkanethiol self-assembled monolayers (SAMs) at the graphene/Cu interfaces. The early stage of intercalation proceeds through graphene grain boundaries or defects within a few seconds at room temperature until stable SAMs are formed after a few hours. The formation of SAMs releases the compressive strain of graphene induced by Cu substrates and make graphene slightly n-doped due to the formation of interface dipoles of the SAMs on metal surfaces. After SAM formation, the graphene is easily delaminated off from the metal substrates and transferred onto insulating substrates. The etchant-free process enables us to decrease the density of charged impurities and the magnitude of potential fluctuation in the transferred graphene, which suppress scattering of carriers. We also demonstrate the removal of alkanethiol SAMs and reuse the substrate. This method will dramatically reduce the cost of graphene transfer, which will benefit industrial applications such as of graphene transparent electrodes.

Handling apparatus for a nuclear reactor fuel assembly

International Nuclear Information System (INIS)

Shallenberger, J.M.; Hornak, L.P.; Desmarchais, W.E.

1978-01-01

An apparatus is disclosed for handling radioactive fuel assembly during transfer operations. The radioactive fuel assembly is drawn up into a shielding sleeve which substantially reduces the level of radioactivity immediately surrounding the sleeve thereby permitting direct access by operating personnel. The lifting assembly which draws the fuel assembly up within the shielding sleeve is mounted to and forms an integral part of the handling apparatus. The shielding sleeve accompanies the fuel assembly during all of the transfer operations

Equation of State for Phospholipid Self-Assembly

DEFF Research Database (Denmark)

Marsh, Derek

2016-01-01

Phospholipid self-assembly is the basis of biomembrane stability. The entropy of transfer from water to self-assembled micelles of lysophosphatidylcholines and diacyl phosphatidylcholines with different chain lengths converges to a common value at a temperature of 44°C. The corresponding enthalpies...... of transfer converge at ∼-18°C. An equation of state for the free energy of self-assembly formulated from this thermodynamic data depends on the heat capacity of transfer as the sole parameter needed to specify a particular lipid. For lipids lacking calorimetric data, measurement of the critical micelle...

Experimental investigations of heat transfer during sodium boiling in fuel assembly model in justification of advanced fast reactor safety

International Nuclear Information System (INIS)

Khafizov, R.R.; Poplavskij, V.M.; Rachkov, V.I.; Sorokin, A.P.; Ashurko, Yu.M.; Volkov, A.V.; Ivanov, E.F.; Privezentsev, V.V.

2015-01-01

The experimental facility is built up and investigation of heat exchange during sodium boiling in simulated fast reactor core assembly in conditions of natural and forced circulation with sodium plenum and upper end shield model are conducted. It is shown that in the presence of sodium plenum there is possibility to provide long-term cooling of fuel assembly when heat flux density on the surface of fuel element simulator up to 140 and 170 kW/m 2 in conditions of natural and forced circulation, respectively. The obtained data is used for improving calculational model of sodium boiling process in fuel assembly and calculational code COREMELT verification. It is pointed out that heat transfer coefficients in the case of liquid metal boiling in fuel assemblies are slightly over the ones in the case of liquid metals boiling in pipes and pool boiling [ru

Support-Free Transfer of Ultrasmooth Graphene Films Facilitated by Self-Assembled Monolayers for Electronic Devices and Patterns.

Science.gov (United States)

Wang, Bin; Huang, Ming; Tao, Li; Lee, Sun Hwa; Jang, A-Rang; Li, Bao-Wen; Shin, Hyeon Suk; Akinwande, Deji; Ruoff, Rodney S

2016-01-26

We explored a support-free method for transferring large area graphene films grown by chemical vapor deposition to various fluoric self-assembled monolayer (F-SAM) modified substrates including SiO2/Si wafers, polyethylene terephthalate films, and glass. This method yields clean, ultrasmooth, and high-quality graphene films for promising applications such as transparent, conductive, and flexible films due to the absence of residues and limited structural defects such as cracks. The F-SAM introduced in the transfer process can also lead to graphene transistors with enhanced field-effect mobility (up to 10,663 cm(2)/Vs) and resistance modulation (up to 12×) on a standard silicon dioxide dielectric. Clean graphene patterns can be realized by transfer of graphene onto only the F-SAM modified surfaces.

Fuel assembly guide tube

International Nuclear Information System (INIS)

Jabsen, F.S.

1979-01-01

This invention is directed toward a nuclear fuel assembly guide tube arrangement which restrains spacer grid movement due to coolant flow and which offers secondary means for supporting a fuel assembly during handling and transfer operations

Programmed Nanomaterial Assemblies in Large Scales: Applications of Synthetic and Genetically- Engineered Peptides to Bridge Nano-Assemblies and Macro-Assemblies

Energy Technology Data Exchange (ETDEWEB)

Matsui, Hiroshi

2014-09-09

Work is reported in these areas: Large-scale & reconfigurable 3D structures of precise nanoparticle assemblies in self-assembled collagen peptide grids; Binary QD-Au NP 3D superlattices assembled with collagen-like peptides and energy transfer between QD and Au NP in 3D peptide frameworks; Catalytic peptides discovered by new hydrogel-based combinatorial phage display approach and their enzyme-mimicking 2D assembly; New autonomous motors of metal-organic frameworks (MOFs) powered by reorganization of self-assembled peptides at interfaces; Biomimetic assembly of proteins into microcapsules on oil-in-water droplets with structural reinforcement via biomolecular recognition-based cross-linking of surface peptides; and Biomimetic fabrication of strong freestanding genetically-engineered collagen peptide films reinforced by quantum dot joints. We gained the broad knowledge about biomimetic material assembly from nanoscale to microscale ranges by coassembling peptides and NPs via biomolecular recognition. We discovered: Genetically-engineered collagen-like peptides can be self-assembled with Au NPs to generate 3D superlattices in large volumes (> μm{sup 3}); The assembly of the 3D peptide-Au NP superstructures is dynamic and the interparticle distance changes with assembly time as the reconfiguration of structure is triggered by pH change; QDs/NPs can be assembled with the peptide frameworks to generate 3D superlattices and these QDs/NPs can be electronically coupled for the efficient energy transfer; The controlled assembly of catalytic peptides mimicking the catalytic pocket of enzymes can catalyze chemical reactions with high selectivity; and, For the bacteria-mimicking swimmer fabrication, peptide-MOF superlattices can power translational and propellant motions by the reconfiguration of peptide assembly at the MOF-liquid interface.

Tunneling nanotube (TNT)-mediated neuron-to neuron transfer of pathological Tau protein assemblies.

Science.gov (United States)

Tardivel, Meryem; Bégard, Séverine; Bousset, Luc; Dujardin, Simon; Coens, Audrey; Melki, Ronald; Buée, Luc; Colin, Morvane

2016-11-04

A given cell makes exchanges with its neighbors through a variety of means ranging from diffusible factors to vesicles. Cells use also tunneling nanotubes (TNTs), filamentous-actin-containing membranous structures that bridge and connect cells. First described in immune cells, TNTs facilitate HIV-1 transfer and are found in various cell types, including neurons. We show that the microtubule-associated protein Tau, a key player in Alzheimer's disease, is a bona fide constituent of TNTs. This is important because Tau appears beside filamentous actin and myosin 10 as a specific marker of these fine protrusions of membranes and cytosol that are difficult to visualize. Furthermore, we observed that exogenous Tau species increase the number of TNTs established between primary neurons, thereby facilitating the intercellular transfer of Tau fibrils. In conclusion, Tau may contribute to the formation and function of the highly dynamic TNTs that may be involved in the prion-like propagation of Tau assemblies.

Wide-range light-harvesting donor-acceptor assemblies through specific intergelator interactions via self-assembly.

Science.gov (United States)

Samanta, Suman K; Bhattacharya, Santanu

2012-12-03

We have synthesized two new low-molecular-mass organogelators based on tri-p-phenylene vinylene derivatives, one of which could be designated as the donor whereas the other one is an acceptor. These were prepared specifically to show the intergelator interactions at the molecular level by using donor-acceptor self-assembly to achieve appropriate control over their macroscopic properties. Intermolecular hydrogen-bonding, π-stacking, and van der Waals interactions operate for both the individual components and the mixtures, leading to the formation of gels in the chosen organic solvents. Evidence for intergelator interactions was acquired from various spectroscopic, microscopic, thermal, and mechanical investigations. Due to the photochromic nature of these molecules, interesting photophysical properties, such as solvatochromism and J-type aggregation, were clearly observed. An efficient energy transfer was exhibited by the mixture of donor-acceptor assemblies. An array of four chromophores was built up by inclusion of two known dyes (anthracene and rhodamine 6G) for the energy-transfer studies. Interestingly, an energy-transfer cascade was observed in the assembly of four chromophores in a particular order (anthracene-donor-acceptor-rhodamine 6G), and if one of the components was removed from the assembly the energy transfer process was discontinued. This allowed the build up of a light-harvesting process with a wide range. Excitation at one end produces an emission at the other end of the assembly. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Submersible canned motor transfer pump

International Nuclear Information System (INIS)

Guardiani, R.F.; Pollick, R.D.; Nyilas, C.P.; Denmeade, T.J.

1997-01-01

A transfer pump is described which is used in a waste tank for transferring high-level radioactive liquid waste from a waste tank and having a column assembly, a canned electric motor means, and an impeller assembly with an upper impeller and a lower impeller connected to a shaft of a rotor assembly. The column assembly locates a motor housing with the electric motor means adjacent to the impeller assembly which creates an hydraulic head, and which forces the liquid waste, into the motor housing to cool the electric motor means and to cool and/or lubricate the radial and thrust bearing assemblies. Hard-on-hard bearing surfaces of the bearing assemblies and a ring assembly between the upper impeller and electric motor means grind large particles in the liquid waste flow. Slots in the static bearing member of the radial bearing assemblies further grind down the solid waste particles so that only particles smaller than the clearances in the system can pass there through, thereby resisting damage to and the interruption of the operation of the transfer pump. The column assembly is modular so that sections can be easily assembled, disassembled and/or removed. A second embodiment employs a stator jacket which provides an alternate means for cooling the electric motor means and lubricating and/or cooling the bearing assemblies, and a third embodiment employs a variable level suction device which allows liquid waste to be drawn into the transfer pump from varying and discrete levels in the waste tank. 17 figs

Mononuclear Amido and Binuclear Imido Zirconium Complexes Supported by Dibenzotetraaza[14]annulene Ligands. X-ray Structure of [(Me(4)taa)Zr(&mgr;-NR)(2)Zr(NHR)(2)] (R = Bu(t) or 2,6-C(6)H(3)Me(2)).

Science.gov (United States)

Nikonov, Georgii I.; Blake, Alexander J.; Mountford, Philip

1997-03-12

Reaction of 2 equiv of Li[NH-2,6-C(6)H(3)R(2)] with [(Me(4)taa)ZrCl(2)] (Me(4)taaH(2) = tetramethyldibenzotetraaza[14]annulene) gives the bis(amido) derivatives [(Me(4)taa)Zr(NH-2,6-C(6)H(3)R(2))(2)] [R = Pr(i) (1) and Me (2)]. Addition of Me(4)taaH(2) to [Zr(N-2,6-C(6)H(3)Pr(i)(2))(NH-2,6-C(6)H(3)Pr(i)(2))(2)(py)(2)] also affords 1. The reaction of 2 equiv of aryl or alkyl amines H(2)NR with the bis(alkyl) complex [(Me(4)taa)Zr(CH(2)SiMe(3))(2)] is the most versatile method for preparing [(Me(4)taa)Zr(NHR)(2)] (R = 2,6-C(6)H(3)Pr(i)(2), 2,6-C(6)H(3)Me(2), Ph, or Bu(t)). Reaction of 1 equiv of Me(4)taaH(2) with the binuclear complexes [(Bu(t)NH)(2)Zr(&mgr;-NBu(t))(2)Zr(NHBu(t))(2)] or [(py)(HN-2,6-C(6)H(3)Me(2))(2)Zr(&mgr;-N-2,6-C(6)H(3)Me(2))(2)Zr(NH-2,6-C(6)H(3)Me(2))(2)(py)] gives the asymmetrically substituted derivatives [(Me(4)taa)Zr(&mgr;-NR)(2)Zr(NHR)(2)] [R = Bu(t) (6) or 2,6-C(6)H(3)Me(2) (8)], which have been crystallographically characterized.

DRY TRANSFER FACILITY CRITICALITY SAFETY CALCULATIONS

International Nuclear Information System (INIS)

C.E. Sanders

2005-01-01

This design calculation updates the previous criticality evaluation for the fuel handling, transfer, and staging operations to be performed in the Dry Transfer Facility (DTF) including the remediation area. The purpose of the calculation is to demonstrate that operations performed in the DTF and RF meet the nuclear criticality safety design criteria specified in the ''Project Design Criteria (PDC) Document'' (BSC 2004 [DIRS 171599], Section 4.9.2.2), the nuclear facility safety requirement in ''Project Requirements Document'' (Canori and Leitner 2003 [DIRS 166275], p. 4-206), the functional/operational nuclear safety requirement in the ''Project Functional and Operational Requirements'' document (Curry 2004 [DIRS 170557], p. 75), and the functional nuclear criticality safety requirements described in the ''Dry Transfer Facility Description Document'' (BSC 2005 [DIRS 173737], p. 3-8). A description of the changes is as follows: (1) Update the supporting calculations for the various Category 1 and 2 event sequences as identified in the ''Categorization of Event Sequences for License Application'' (BSC 2005 [DIRS 171429], Section 7). (2) Update the criticality safety calculations for the DTF staging racks and the remediation pool to reflect the current design. This design calculation focuses on commercial spent nuclear fuel (SNF) assemblies, i.e., pressurized water reactor (PWR) and boiling water reactor (BWR) SNF. U.S. Department of Energy (DOE) Environmental Management (EM) owned SNF is evaluated in depth in the ''Canister Handling Facility Criticality Safety Calculations'' (BSC 2005 [DIRS 173284]) and is also applicable to DTF operations. Further, the design and safety analyses of the naval SNF canisters are the responsibility of the U.S. Department of the Navy (Naval Nuclear Propulsion Program) and will not be included in this document. Also, note that the results for the Monitored Geologic Repository (MGR) Site specific Cask (MSC) calculations are limited to the

COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS

Energy Technology Data Exchange (ETDEWEB)

S.O. Bader

1999-10-18

The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be

COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS

International Nuclear Information System (INIS)

S.O. Bader

1999-01-01

The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be

Deterministic nanoparticle assemblies: from substrate to solution

International Nuclear Information System (INIS)

Barcelo, Steven J; Gibson, Gary A; Yamakawa, Mineo; Li, Zhiyong; Kim, Ansoon; Norris, Kate J

2014-01-01

The deterministic assembly of metallic nanoparticles is an exciting field with many potential benefits. Many promising techniques have been developed, but challenges remain, particularly for the assembly of larger nanoparticles which often have more interesting plasmonic properties. Here we present a scalable process combining the strengths of top down and bottom up fabrication to generate deterministic 2D assemblies of metallic nanoparticles and demonstrate their stable transfer to solution. Scanning electron and high-resolution transmission electron microscopy studies of these assemblies suggested the formation of nanobridges between touching nanoparticles that hold them together so as to maintain the integrity of the assembly throughout the transfer process. The application of these nanoparticle assemblies as solution-based surface-enhanced Raman scattering (SERS) materials is demonstrated by trapping analyte molecules in the nanoparticle gaps during assembly, yielding uniformly high enhancement factors at all stages of the fabrication process. (paper)

Moisture Research - Optimizing Wall Assemblies

Energy Technology Data Exchange (ETDEWEB)

Arena, L.; Mantha, P.

2013-05-01

The Consortium for Advanced Residential Buildings (CARB) evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls.

Ex-vessel nuclear fuel transfer system

International Nuclear Information System (INIS)

1977-01-01

A system is described for transferring reactor fuel assemblies between a fuel storage area and a fuel transfer area while the fuel assemblies remain completely submerged in a continuous body of coolant. The invention relates particularly to sodium cooled fast breeder reactors. (UK)

Deep-sea genetic resources: New frontiers for science and stewardship in areas beyond national jurisdiction

Science.gov (United States)

Harden-Davies, Harriet

2017-03-01

The deep-sea is a large source of marine genetic resources (MGR), which have many potential uses and are a growing area of research. Much of the deep-sea lies in areas beyond national jurisdiction (ABNJ), including 65% of the global ocean. MGR in ABNJ occupy a significant gap in the international legal framework. Access and benefit sharing of MGR is a key issue in the development of a new international legally-binding instrument under the United Nations Convention on the Law of the Sea (UNCLOS) for the conservation and sustainable use of marine biological diversity in ABNJ. This paper examines how this is relevant to deep-sea scientific research and identifies emerging challenges and opportunities. There is no internationally agreed definition of MGR, however, deep-sea genetic resources could incorporate any biological material including genes, proteins and natural products. Deep-sea scientific research is the key actor accessing MGR in ABNJ and sharing benefits such as data, samples and knowledge. UNCLOS provides the international legal framework for marine scientific research, international science cooperation, capacity building and marine technology transfer. Enhanced implementation could support access and benefit sharing of MGR in ABNJ. Deep-sea scientific researchers could play an important role in informing practical new governance solutions for access and benefit sharing of MGR that promote scientific research in ABNJ and support deep-sea stewardship. Advancing knowledge of deep-sea biodiversity in ABNJ, enhancing open-access to data and samples, standardisation and international marine science cooperation are significant potential opportunity areas.

Three dimensional conjugated heat transfer analysis in sodium fast reactor wire-wrapped fuel assembly

International Nuclear Information System (INIS)

Peniguel, C.; Rupp, I.; Juhel, JP.; Rolfo, S.; Guillaud, M.; Gervais, N.

2009-01-01

Fast reactors with liquid metal coolant have recently received a renewed interest owing to a more efficient usage of the primary uranium resources, and they are one of the proposal for the next Generation IV. In order to evaluate nuclear power plant design and safety, 3D analysis of the flow and heat transfer in a wire spacer fuel assembly are ongoing at EDF. The introduction of the wire wrapped spacers, helically wound along the pin axis, enhances the mixing of the coolant between sub-channels and prevents contact between the fuel pins. The mesh generation step constitutes a challenging task if a reasonable amount of cells in conjunction with a suitable spatial discretization is wanted. Several approaches have been investigated and will be presented. Quite complex global flow patterns are found using either k-ε or preferably Reynolds Stress turbulent models. Preliminary conjugated heat transfer calculations using a coupling between the finite element thermal code SYRTHES and the finite volume CFD code Code Saturne are also shown. (author)

TOOL ASSEMBLY WITH BI-DIRECTIONAL BEARING

Science.gov (United States)

Longhurst, G.E.

1961-07-11

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.

Equations of macrotransport in reactor fuel assemblies

International Nuclear Information System (INIS)

Sorokin, A.P.; Zhukov, A.V.; Kornienko, Yu.N.; Ushakov, P.A.

1986-01-01

The rigorous statement of equations of macrotransport is obtained. These equations are bases for channel-by-channel methods of thermohydraulic calculations of reactor fuel assemblies within the scope of the model of discontinuous multiphase coolant flow (including chemical reactions); they also describe a wide range of problems on thermo-physical reactor fuel assembly justification. It has been carried out by smoothing equations of mass, momentum and enthalpy transfer in cross section of each phase of the elementary fuel assembly subchannel. The equation for cross section flows is obtaind by smoothing the equation of momentum transfer on the interphase. Interaction of phases on the channel boundary is described using the Stanton number. The conclusion is performed using the generalized equation of substance transfer. The statement of channel-by-channel method without the scope of homogeneous flow model is given

Submolecular Gates Self-Assemble for Hot-Electron Transfer in Proteins.

Science.gov (United States)

Filip-Granit, Neta; Goldberg, Eran; Samish, Ilan; Ashur, Idan; van der Boom, Milko E; Cohen, Hagai; Scherz, Avigdor

2017-07-27

Redox reactions play key roles in fundamental biological processes. The related spatial organization of donors and acceptors is assumed to undergo evolutionary optimization facilitating charge mobilization within the relevant biological context. Experimental information from submolecular functional sites is needed to understand the organization strategies and driving forces involved in the self-development of structure-function relationships. Here we exploit chemically resolved electrical measurements (CREM) to probe the atom-specific electrostatic potentials (ESPs) in artificial arrays of bacteriochlorophyll (BChl) derivatives that provide model systems for photoexcited (hot) electron donation and withdrawal. On the basis of computations we show that native BChl's in the photosynthetic reaction center (RC) self-assemble at their ground-state as aligned gates for functional charge transfer. The combined computational and experimental results further reveal how site-specific polarizability perpendicular to the molecular plane enhances the hot-electron transport. Maximal transport efficiency is predicted for a specific, ∼5 Å, distance above the center of the metalized BChl, which is in remarkably close agreement with the distance and mutual orientation of corresponding native cofactors. These findings provide new metrics and guidelines for analysis of biological redox centers and for designing charge mobilizing machines such as artificial photosynthesis.

De novo assembly of a cotyledon-enriched transcriptome map of Vicia faba (L. for transfer cell research

Directory of Open Access Journals (Sweden)

Kiruba Shankari eArun Chinnappa

2015-04-01

Full Text Available Vicia faba (L. is an important cool-season grain legume species used widely in agriculture but also in plant physiology research, particularly as an experimental model to study transfer cell (TC development. Adaxial epidermal cells of isolated cotyledons can be induced to form functional TCs, thus providing a valuable experimental system to investigate genetic regulation of TC development. The genome of V. faba is exceedingly large (ca. 13 Gb, however, and limited genomic information is available for this species. To provide a resource for transcript profiling of epidermal TC development, we have undertaken de novo assembly of a cotyledon-enriched transcriptome map for V. faba. Illumina paired-end sequencing of total RNA pooled from different tissues and different stages, including isolated cotyledons induced to form TCs, generated 69.5M reads, of which 65.8M were used for assembly following trimming and quality control. Assembly using a De-Bruijn graph-based approach within CLC Genomics Workbench v6.1 generated 21,297 contigs, of which 80.6% were successfully annotated against GO terms. The assembly was validated against known V. faba cDNAs held in GenBank, including transcripts previously identified as being specifically expressed in epidermal cells across TC trans-differentiation. This cotyledon-enriched transcriptome map therefore provides a valuable tool for future transcript profiling of epidermal TC development, and also enriches the genetic resources available for this important legume crop species.

Advanced gray rod control assembly

Science.gov (United States)

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

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.

Electron transfer kinetics of cytochrome c immobilized on a phenolic terminated thiol self assembled monolayer determined by scanning electrochemical microscopy

International Nuclear Information System (INIS)

Alizadeh, Vali; Mousavi, Mir Fazlollah; Mehrgardi, Masoud Ayatollahi; Kazemi, Sayed Habib; Sharghi, Hashem

2011-01-01

Highlights: → Preparing a thiolated phenolic self-assembled monolayer surface (SAM). → Application of this SAM to immobilize cytochrome C. → Scanning electrochemical microscopy used for these studies. → Determination of both tunneling electron transfer and bimolecular rate constants between the immobilized protein-substrate and probe. - Abstract: In the present manuscript, the electrochemical behavior of cytochrome c (cyt-c) immobilized onto a phenolic terminated self assembled monolayer (SAM) on a gold electrode is investigated using cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM). The tunneling electron transfer (ET) rate constant between the immobilized protein and the underlying electrode surface, and also the bimolecular ET rate constant between the immobilized protein and a probe has been obtained using approach curves that were obtained by SECM. The approach curves were recorded at different substrate overpotentials in the presence of various concentrations of ferrocyanide as a probe and various surface concentrations of cyt-c; then the standard tunneling ET and bimolecular rate constants are obtained as 3.4 ± 0.3 s -1 and (2.0 ± 0.5) x 10 7 cm 3 mol -1 s -1 , respectively.

Electron transfer kinetics of cytochrome c immobilized on a phenolic terminated thiol self assembled monolayer determined by scanning electrochemical microscopy

Energy Technology Data Exchange (ETDEWEB)

Alizadeh, Vali [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Mousavi, Mir Fazlollah, E-mail: mousavim@modares.ac.ir [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Mehrgardi, Masoud Ayatollahi [Department of Chemistry, University of Isfahan, Isfahan (Iran, Islamic Republic of); Kazemi, Sayed Habib [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan (Iran, Islamic Republic of); Sharghi, Hashem [Department of Chemistry, Shiraz University, Shiraz (Iran, Islamic Republic of)

2011-07-01

Highlights: > Preparing a thiolated phenolic self-assembled monolayer surface (SAM). > Application of this SAM to immobilize cytochrome C. > Scanning electrochemical microscopy used for these studies. > Determination of both tunneling electron transfer and bimolecular rate constants between the immobilized protein-substrate and probe. - Abstract: In the present manuscript, the electrochemical behavior of cytochrome c (cyt-c) immobilized onto a phenolic terminated self assembled monolayer (SAM) on a gold electrode is investigated using cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM). The tunneling electron transfer (ET) rate constant between the immobilized protein and the underlying electrode surface, and also the bimolecular ET rate constant between the immobilized protein and a probe has been obtained using approach curves that were obtained by SECM. The approach curves were recorded at different substrate overpotentials in the presence of various concentrations of ferrocyanide as a probe and various surface concentrations of cyt-c; then the standard tunneling ET and bimolecular rate constants are obtained as 3.4 {+-} 0.3 s{sup -1} and (2.0 {+-} 0.5) x 10{sup 7} cm{sup 3} mol{sup -1} s{sup -1}, respectively.

Call for Nominations The Nusselt Reynolds Prize Sponsored by Assembly of World Conferences on Experimental Heat Transfer, Fluid Mechanics, and Thermodynamics

Science.gov (United States)

Kasagi, Nobuhide

2000-01-01

The Nusselt Reynolds Prize has been established by the Assembly of World Conferences to commemorate outstanding contributions by Wilhelm Nusselt and Osborne Reynolds as experimentalists, researchers, educators, and authors. As many as three prizes may be bestowed at every World Conference, one in each of the areas of heat transfer, fluid mechanics, thermodynamics, or any combination of these.

Thermal hydraulic analysis of Pb-Bi cooled HYPER fuel assemblies using SLTHEN code

International Nuclear Information System (INIS)

Tak, Nam Il; Song, Tae Y.; Park, Won S.; Kim, Chang Hyun

2002-12-01

In the present work, the existing SLTHEN code, which had been originally developed for subchannel analysis of sodium cooled fast reactors, was modified and applied to the Pb-Bi cooled HYPER core which consists of 237 fuel assemblies (TRU assemblies). In the analysis of single fuel assembly having chopped cosine power profile, the validation and the assessment of usefulness of the modified SLTHEN were focused. In the quantitative comparison, the results of the modified SLTHEN agreed well with those of analytical calculations and of MATRA. For the qualitative approaches, the sensitivity calculations for intra-assembly gap flow and turbulent mixing parameter were used. The sensitivity analysis results showed that the modified SLTHEN can provide reasonable simulations of subchannel thermal hydraulics. In particular, turbulent mixing parameter which is known as the most uncertain parameter in subchannel analyses did not affect largely the maximum cladding temperature. Therefore, it can be said that the results of single assembly show the usefulness of the modified SLTHEN code for thermal hydraulic analysis and design of HYPER under the conceptual design stage. In order to assess intra-assembly heat transfer, subchannel analyses were implemented for two types of 7 assemblies; 1) artificial 7 fuel assemblies to maximize intra-assembly heat transfer, 2) central 7 fuel assemblies in the HYPER reference core. The results showed that the modified SLTHEN can reasonably simulate intra-heat transfer and the amount of intra-assembly heat transfer is not so large in HYPER conditions. Particularly, intra-heat transfer did not affect the maximum coolant and the maximum cladding temperatures which are major parameters in conceptual core designs. The capability of full core thermal hydraulic analysis was confirmed by the analysis of 45 fuel assemblies in 1/6 HYPER core at the first cycle. The SLTHEN predicted that the reference design parameters are acceptable in terms of thermal

Fuel assembly

International Nuclear Information System (INIS)

Kurihara, Kunitoshi; Azekura, Kazuo.

1992-01-01

In a reactor core of a heavy water moderated light water cooled pressure tube type reactor, no sufficient effects have been obtained for the transfer width to a negative side of void reactivity change in a region of a great void coefficient. Then, a moderation region divided into upper and lower two regions is disposed at the central portion of a fuel assembly. Coolants flown into the lower region can be discharged to the cooling region from an opening disposed at the upper end portion of the lower region. Light water flows from the lower region of the moderator region to the cooling region of the reactor core upper portion, to lower the void coefficient. As a result, the reactivity performance at low void coefficient, i.e., a void reaction rate is transferred to the negative side. Thus, this flattens the power distribution in the fuel assembly, increases the thermal margin and enables rapid operaiton and control of the reactor core, as well as contributes to the increase of fuel burnup ratio and reduction of the fuel cycle cost. (N.H.)

Container for spent fuel assembly

International Nuclear Information System (INIS)

Sawai, Takeshi.

1996-01-01

The container of the present invention comprises a container main body having a body portion which can contain spent fuel assemblies and a lid, and heat pipes having an evaporation portion disposed along the outer surface of the spent fuel assemblies to be contained and a condensation portion exposed to the outside of the container main body. Further, the heat pipe is formed spirally at the evaporation portions so as to surround the outer circumference of the spent fuel assemblies, branched into a plurality of portions at the condensation portion, each of the branched portion of the condensation portion being exposed to the outside of the container main body, and is tightly in contact with the periphery of the slit portions disposed to the container main body. Then, since released after heat is transferred to the outside of the container main body from the evaporation portion of the heat pipe along the outer surface of the spent fuel assemblies by way of the condensation portion of the heat pipes exposed to the outside of the container main body, the efficiency of the heat transfer is extremely improved to enhance the effect of removing heat of spent fuel assemblies. Further, cooling effect is enhanced by the spiral form of the evaporation portion and the branched condensation portion. (N.H.)

Fuel transfer system for a nuclear reactor

International Nuclear Information System (INIS)

Katz, L.R.; Marshall, J.R.; Desmarchais, W.E.

1977-01-01

Disclosed is a fuel transfer system for moving nuclear reactor fuel assemblies from a new fuel storage pit to a containment area containing the nuclear reactor, and for transferring spent fuel assemblies under water from the reactor to a spent fuel storage area. The system includes an underwater track which extends through a wall dividing the fuel building from the reactor containment and a car on the track serves as the vehicle for moving fuel assemblies between these two areas. The car is driven by a motor and linkage extending from an operating deck to a chain belt drive on the car. A housing pivotally mounted at its center on the car is hydraulically actuated to vertically receive a fuel assembly which then is rotated to a horizontal position to permit movement through the wall between the containment and fuel building areas. Return to the vertical position provides for fuel assembly removal and the reverse process is repeated when transferring an assembly in the opposite direction. Limit switches used in controlling operation of the system are designed to be replaced from the operating deck when necessary by tools designed for this purpose. 5 claims, 8 figures

Fuel transfer machine

International Nuclear Information System (INIS)

Bernstein, I.

1978-01-01

A nuclear fuel transfer machine for transferring fuel assemblies through the fuel transfer tube of a nuclear power generating plant containment structure is described. A conventional reversible drive cable is attached to the fuel transfer carriage to drive it horizontally through the tube. A shuttle carrying a sheave at each end is arranged in parallel with the carriage to also travel into the tube. The cable cooperating with the sheaves permit driving a relatively short fuel transfer carriage a large distance without manually installing sheaves or drive apparatus in the tunnel. 8 claims, 3 figures

Dynamical simulation of electron transfer processes in self-assembled monolayers at metal surfaces using a density matrix approach.

Science.gov (United States)

Prucker, V; Bockstedte, M; Thoss, M; Coto, P B

2018-03-28

A single-particle density matrix approach is introduced to simulate the dynamics of heterogeneous electron transfer (ET) processes at interfaces. The characterization of the systems is based on a model Hamiltonian parametrized by electronic structure calculations and a partitioning method. The method is applied to investigate ET in a series of nitrile-substituted (poly)(p-phenylene)thiolate self-assembled monolayers adsorbed at the Au(111) surface. The results show a significant dependence of the ET on the orbital symmetry of the donor state and on the molecular and electronic structure of the spacer.

Dynamical simulation of electron transfer processes in self-assembled monolayers at metal surfaces using a density matrix approach

Science.gov (United States)

Prucker, V.; Bockstedte, M.; Thoss, M.; Coto, P. B.

2018-03-01

A single-particle density matrix approach is introduced to simulate the dynamics of heterogeneous electron transfer (ET) processes at interfaces. The characterization of the systems is based on a model Hamiltonian parametrized by electronic structure calculations and a partitioning method. The method is applied to investigate ET in a series of nitrile-substituted (poly)(p-phenylene)thiolate self-assembled monolayers adsorbed at the Au(111) surface. The results show a significant dependence of the ET on the orbital symmetry of the donor state and on the molecular and electronic structure of the spacer.

Self-Assembled Colloidal Particle Clusters from In Situ Pickering-Like Emulsion Polymerization via Single Electron Transfer Mechanism.

Science.gov (United States)

Yuan, Jinfeng; Zhao, Weiting; Pan, Mingwang; Zhu, Lei

2016-08-01

A simple route is reported to synthesize colloidal particle clusters (CPCs) from self-assembly of in situ poly(vinylidene fluoride)/poly(styrene-co-tert-butyl acrylate) [PVDF/P(St-co-tBA)] Janus particles through one-pot seeded emulsion single electron transfer radical polymerization. In the in situ Pickering-like emulsion polymerization, the tBA/St/PVDF feed ratio and polymerization temperature are important for the formation of well-defined CPCs. When the tBA/St/PVDF feed ratio is 0.75 g/2.5 g/0.5 g and the reaction temperature is 35 °C, relatively uniform raspberry-like CPCs are obtained. The hydrophobicity of the P(St-co-tBA) domains and the affinity of PVDF to the aqueous environment are considered to be the driving force for the self-assembly of the in situ formed PVDF/P(St-co-tBA) Janus particles. The resultant raspberry-like CPCs with PVDF particles protruding outward may be promising for superhydrophobic smart coatings. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rotor assembly and method for automatically processing liquids

Science.gov (United States)

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

1992-12-22

A rotor assembly is described for performing a relatively large number of processing steps upon a sample, such as a whole blood sample, and a diluent, such as water. It includes a rotor body for rotation about an axis and includes a network of chambers within which various processing steps are performed upon the sample and diluent and passageways through which the sample and diluent are transferred. A transfer mechanism is movable through the rotor body by the influence of a magnetic field generated adjacent the transfer mechanism and movable along the rotor body, and the assembly utilizes centrifugal force, a transfer of momentum and capillary action to perform any of a number of processing steps such as separation, aliquoting, transference, washing, reagent addition and mixing of the sample and diluent within the rotor body. The rotor body is particularly suitable for automatic immunoassay analyses. 34 figs.

Contact- and Protein Transfer-Dependent Stimulation of Assembly of the Gliding Motility Machinery in Myxococcus xanthus.

Directory of Open Access Journals (Sweden)

Beata Jakobczak

2015-07-01

Full Text Available Bacteria engage in contact-dependent activities to coordinate cellular activities that aid their survival. Cells of Myxococcus xanthus move over surfaces by means of type IV pili and gliding motility. Upon direct contact, cells physically exchange outer membrane (OM lipoproteins, and this transfer can rescue motility in mutants lacking lipoproteins required for motility. The mechanism of gliding motility and its stimulation by transferred OM lipoproteins remain poorly characterized. We investigated the function of CglC, GltB, GltA and GltC, all of which are required for gliding. We demonstrate that CglC is an OM lipoprotein, GltB and GltA are integral OM β-barrel proteins, and GltC is a soluble periplasmic protein. GltB and GltA are mutually stabilizing, and both are required to stabilize GltC, whereas CglC accumulate independently of GltB, GltA and GltC. Consistently, purified GltB, GltA and GltC proteins interact in all pair-wise combinations. Using active fluorescently-tagged fusion proteins, we demonstrate that GltB, GltA and GltC are integral components of the gliding motility complex. Incorporation of GltB and GltA into this complex depends on CglC and GltC as well as on the cytoplasmic AglZ protein and the inner membrane protein AglQ, both of which are components of the gliding motility complex. Conversely, incorporation of AglZ and AglQ into the gliding motility complex depends on CglC, GltB, GltA and GltC. Remarkably, physical transfer of the OM lipoprotein CglC to a ΔcglC recipient stimulates assembly of the gliding motility complex in the recipient likely by facilitating the OM integration of GltB and GltA. These data provide evidence that the gliding motility complex in M. xanthus includes OM proteins and suggest that this complex extends from the cytoplasm across the cell envelope to the OM. These data add assembly of gliding motility complexes in M. xanthus to the growing list of contact-dependent activities in bacteria.

Direct self-assembling and patterning of semiconductor quantum dots on transferable elastomer layer

Energy Technology Data Exchange (ETDEWEB)

Coppola, Sara [Institute of Applied Sciences and Intelligent System- CNR, Via Campi Flegrei 34, Pozzuoli, 80078 (Italy); Vespini, Veronica, E-mail: v.vespini@isasi.cnr.it [Institute of Applied Sciences and Intelligent System- CNR, Via Campi Flegrei 34, Pozzuoli, 80078 (Italy); Olivieri, Federico [Institute of Applied Sciences and Intelligent System- CNR, Via Campi Flegrei 34, Pozzuoli, 80078 (Italy); University of Naples Federico II, Department of Chemical Materials and Production Engineering, Piazzale Tecchio 80, Naples 80125 (Italy); Nasti, Giuseppe; Todino, Michele; Mandracchia, Biagio; Pagliarulo, Vito; Ferraro, Pietro [Institute of Applied Sciences and Intelligent System- CNR, Via Campi Flegrei 34, Pozzuoli, 80078 (Italy)

2017-03-31

Highlights: • A quantum dots self-patterning on micrometrical polymeric array is proposed. • The effect of a quantum dots mix on the array is evaluated. • A PDMS membrane is exploited to transfer the pattern on it. - Abstract: Functionalization of thin and stretchable polymer layers by nano- and micro-patterning of nanoparticles is a very promising field of research that can lead to many different applications in biology and nanotechnology. In this work, we present a new procedure to self-assemble semiconductor quantum dots (QDs) nanoparticles by a simple fabrication process on a freestanding flexible PolyDiMethylSiloxane (PDMS) membrane. We used a Periodically Poled Lithium Niobate (PPLN) crystal to imprint a micrometrical pattern on the PDMS membrane that drives the QDs self-structuring on its surface. This process allows patterning QDs with different wavelength emissions in a single step in order to tune the overall emission spectrum of the composite, tuning the QDs mixing ratio.

Indirect evaporative coolers with enhanced heat transfer

Science.gov (United States)

Kozubal, Eric; Woods, Jason; Judkoff, Ron

2015-09-22

A separator plate assembly for use in an indirect evaporative cooler (IEC) with an air-to-air heat exchanger. The assembly includes a separator plate with a first surface defining a dry channel and a second surface defining a wet channel. The assembly includes heat transfer enhancements provided on the first surface for increasing heat transfer rates. The heat transfer enhancements may include slit fins with bodies extending outward from the first surface of separator plate or may take other forms including vortex generators, offset strip fins, and wavy fins. In slit fin implementations, the separator plate has holes proximate to each of the slit fins, and the separator plate assembly may include a sealing layer applied to the second surface of the separator plate to block air flow through the holes. The sealing layer can be a thickness of adhesive, and a layer of wicking material is applied to the adhesive.

Direct electrochemistry and intramolecular electron transfer of ascorbate oxidase confined on L-cysteine self-assembled gold electrode.

Science.gov (United States)

Patil, Bhushan; Kobayashi, Yoshiki; Fujikawa, Shigenori; Okajima, Takeyoshi; Mao, Lanqun; Ohsaka, Takeo

2014-02-01

A direct electrochemistry and intramolecular electron transfer of multicopper oxidases are of a great importance for the fabrication of these enzyme-based bioelectrochemical-devices. Ascorbate oxidase from Acremonium sp. (ASOM) has been successfully immobilized via a chemisorptive interaction on the l-cysteine self-assembled monolayer modified gold electrode (cys-SAM/AuE). Thermodynamics and kinetics of adsorption of ASOM on the cys-SAM/AuE were studied using cyclic voltammetry. A well-defined redox wave centered at 166±3mV (vs. Ag│AgCl│KCl(sat.)) was observed in 5.0mM phosphate buffer solution (pH7.0) at the fabricated ASOM electrode, abbreviated as ASOM/cys-SAM/AuE, confirming a direct electrochemistry, i.e., a direct electron transfer (DET) between ASOM and cys-SAM/AuE. The direct electrochemistry of ASOM was further confirmed by taking into account the chemical oxidation of ascorbic acid (AA) by O2 via an intramolecular electron transfer in the ASOM as well as the electrocatalytic oxidation of AA at the ASOM/cys-SAM/AuE. Thermodynamics and kinetics of the adsorption of ASOM on the cys-SAM/AuE have been elaborated along with its direct electron transfer at the modified electrodes on the basis of its intramolecular electron transfer and electrocatalytic activity towards ascorbic acid oxidation and O2 reduction. ASOM saturated surface area was obtained as 2.41×10(-11)molcm(-2) with the apparent adsorption coefficient of 1.63×10(6)Lmol(-1). The ASOM confined on the cys-SAM/AuE possesses its essential enzymatic function. © 2013.

L-Area STS MTR/NRU/NRX Grapple Assembly Closure Mechanics Review

International Nuclear Information System (INIS)

Huizenga, D. J.

2016-01-01

A review of the closure mechanics associated with the Shielded Transfer System (STS) MTR/NRU/NRX grapple assembly utilized at the Savannah River Site (SRS) was performed. This review was prompted by an operational event which occurred at the Canadian Nuclear Laboratories (CNL) utilizing a DTS-XL grapple assembly which is essentially identical to the STS MTR/NRU/NRX grapple assembly used at the SRS. The CNL operational event occurred when a NRU/NRX fuel basket containing spent nuclear fuel assemblies was inadvertently released by the DTS-XL grapple assembly during a transfer. The SM review of the STS MTR/NRU/NRX grapple assembly will examine the operational aspects of the STS and the engineered features of the STS which prevent such an event at the SRS. The design requirements for the STS NRU/NRX modifications and the overall layout of the STS are provided in other documents.

Heat transfer assembly for a fluorescent lamp and fixture

Science.gov (United States)

Siminovitch, M.J.; Rubenstein, F.M.; Whitman, R.E.

1992-12-29

In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure. 11 figs.

Design of triads for probing the direct through space energy transfers in closely spaced assemblies.

Science.gov (United States)

Camus, Jean-Michel; Aly, Shawkat M; Fortin, Daniel; Guilard, Roger; Harvey, Pierre D

2013-08-05

Using a selective stepwise Suzuki cross-coupling reaction, two trimers built on three different chromophores were prepared. These trimers exhibit a D(^)A1-A2 structure where the donor D (octa-β-alkyl zinc(II)porphyrin either as diethylhexamethyl, 10a, or tetraethyltetramethyl, 10b, derivatives) through space transfers the S1 energy to two different acceptors, di(4-ethylbenzene) zinc(II)porphyrin (A1; acceptor 1) placed cofacial with D, and the corresponding free base (A2; acceptor 2), which is meso-meso-linked with A1. This structure design allows for the possibility of comparing two series of assemblies, 9a,b (D(^)A1) with 10a,b (D(^)Â1-A2), for the evaluation of the S1 energy transfer for the global process D*→A2 in the trimers. From the comparison of the decays of the fluorescence of D, the rates for through space energy transfer, kET for 10a,b (kET ≈ 6.4 × 10(9) (10a), 5.9 × 10(9) s(-1) (10b)), and those for the corresponding cofacial D(^)A1 systems, 9a,b, (kET ≈ 5.0 × 10(9) (9a), 4.7 × 10(9) s(-1) (9b)), provide an estimate for kET for the direct through space D*→A2 process (i.e., kET(D(^)A1-A2) - kET(D(^)A1) = kET(D*→A2) ∼ 1 × 10(9) s(-1)). This channel of relaxation represents ∼15% of kET for D*→A1.

Effect of lattice deformation on temperature fields and heat transfer in the fuel elements of characteristic zones for a model of fast reactor fuel assembly

International Nuclear Information System (INIS)

Zhukov, A.V.; Matyukhin, N.M.; Sviridenko, E.Ya.

1980-01-01

Given are the experimental results for temperature fields in the model assembly in nonribbed simulators of the BN-600-type reactor fuel elements in the course of deformation of the lattice caused by shifting of the central and peripheral (lateral, angular) fuel elements by the value of the gap between the fuel elements (the limiting case when the fuel elements touch each other along the whole length). An assembly consisting of 37 electroheated pipes arranged in a triangular lattice with a relative step of S/d=1.185 is used as a model. The experiments were carried out on the sodium stand at constant energy release along the length of the fuel element simulators and at the Pe number changing in the 14-700 range. The data obtained show considerable increase of nonuniformities of the fuel element temperatures for characteristic zones of the fuel cassette assembly models of the fast reactor at deviations of the lattice geometric sizes from the nominal ones. For the central nonribbed element the temperature nonuniformity increases approximately 7.5 times and for the lateral element approximately 6 times when the elements touch each other along the whole length. The shift the central nonribbed element by the value of the gap between the fu.el elements leads to the decrease of heat transfer in comparison with heat transfer at the nominal geometry approximately 3-7 times in the 10-450 range for the Pe numbers. It is shown that the coolant temperature distribution along the assembly radius has a complex character (with a peak between the centre and the perifery) caused by redistribution of coolant consumptions due to fuel element lattice deformation

Chirality and energy transfer amplified circularly polarized luminescence in composite nanohelix

Science.gov (United States)

Yang, Dong; Duan, Pengfei; Zhang, Li; Liu, Minghua

2017-01-01

Transfer of both chirality and energy information plays an important role in biological systems. Here we show a chiral donor π-gelator and assembled it with an achiral π-acceptor to see how chirality and energy can be transferred in a composite donor–acceptor system. It is found that the individual chiral gelator can self-assemble into nanohelix. In the presence of the achiral acceptor, the self-assembly can also proceed and lead to the formation of the composite nanohelix. In the composite nanohelix, an energy transfer is realized. Interestingly, in the composite nanohelix, the achiral acceptor can both capture the supramolecular chirality and collect the circularly polarized energy from the chiral donor, showing both supramolecular chirality and energy transfer amplified circularly polarized luminescence (ETACPL). PMID:28585538

Metrology for ITER Assembly

International Nuclear Information System (INIS)

Bogusch, E.

2006-01-01

The overall dimensions of the ITER Tokamak and the particular assembly sequence preclude the use of conventional optical metrology, mechanical jigs and traditional dimensional control equipment, as used for the assembly of smaller, previous generation, fusion devices. This paper describes the state of the art of the capabilities of available metrology systems, with reference to the previous experience in Fusion engineering and in other industries. Two complementary procedures of transferring datum from the primary datum network on the bioshield to the secondary datum s inside the VV with the desired accuracy of about 0.1 mm is described, one method using the access directly through the ports and the other using transfer techniques, developed during the co-operation with ITER/EFDA. Another important task described is the development of a method for the rapid and easy measurement of the gaps between sectors, required for the production of the customised splice plates between them. The scope of the paper includes the evaluation of the composition and cost of the systems and team of technical staff required to meet the requirements of the assembly procedure. The results from a practical, full-scale demonstration of the methodologies used, using the proposed equipment, is described. This work has demonstrated the feasibility of achieving the necessary accuracies for the successful building of ITER. (author)

A swivelling transfer device for nuclear reactors

International Nuclear Information System (INIS)

Allain, Albert; Mulot, Pierre; Filloleau, Etienne

1974-01-01

The invention relates to a swivelling transfer device for fuel-assemblies. According to the invention, the device comprises, within a protective enclosure, a swivelling system comprising two sets of rails rotatable about an axis and so arranged that the lower and thereof penetrates into the extensions of the extremities of ramps dipped into the reactor and into a storage enclosure. This can apply to the transfer of nuclear reactor fuel assemblies, in particular for reactors of the molten sodium fast neutron type [fr

3D Assembly Group Analysis for Cognitive Automation

Directory of Open Access Journals (Sweden)

Christian Brecher

2012-01-01

Full Text Available A concept that allows the cognitive automation of robotic assembly processes is introduced. An assembly cell comprised of two robots was designed to verify the concept. For the purpose of validation a customer-defined part group consisting of Hubelino bricks is assembled. One of the key aspects for this process is the verification of the assembly group. Hence a software component was designed that utilizes the Microsoft Kinect to perceive both depth and color data in the assembly area. This information is used to determine the current state of the assembly group and is compared to a CAD model for validation purposes. In order to efficiently resolve erroneous situations, the results are interactively accessible to a human expert. The implications for an industrial application are demonstrated by transferring the developed concepts to an assembly scenario for switch-cabinet systems.

The pedagogical value of Disassemble/Analyze/Assemble (DAA) activities: Assessing the potential for motivation and transfer

Science.gov (United States)

Dalrymple, Odesma Onika

Undergraduate engineering institutions are currently seeking to improve recruiting practices and to retain engineering majors particularly by addressing what many studies document as a major challenge of poor instruction. There is an undisputed need for instructional practices that motivate students in addition to facilitating the transfer of learning beyond the classroom. Reverse engineering and product dissection, more broadly termed Disassemble/Analyze/Assemble (DAA) activities, have shown potential to address these concerns, based on the reviews of students and professors alike. DAA activities involve the systematic deconstruction of an artifact, the subsequent analysis and possible reconstruction of its components for the purpose of understanding the embodied fundamental concepts, design principles and developmental processes. These activities have been part of regular industry practice for some time; however, the systematic analysis of their benefits for learning and instruction is a relatively recent phenomenon. A number of studies have provided highly descriptive accounts of curricula and possible outcomes of DAA activities; but, relatively few have compared participants doing DAA activities to a control group doing more traditional activities. In this respect, two quasi-experiments were conducted as part of a first-year engineering laboratory, and it was hypothesized that students who engaged in the DAA activity would be more motivated and would demonstrate higher frequencies of transfer than the control. A DAA activity that required students to disassemble a single-use camera and analyze its components to discover how it works was compared to a step-by-step laboratory activity in the first experiment and a lecture method of instruction in the second experiment. In both experiments, over forty percent of the students that engaged in the DAA activity demonstrated the ability to transfer the knowledge gained about the functions of the camera's components and

Plant X-tender: An extension of the AssemblX system for the assembly and expression of multigene constructs in plants

Science.gov (United States)

Machens, Fabian; Coll, Anna; Baebler, Špela; Messerschmidt, Katrin; Gruden, Kristina

2018-01-01

Cloning multiple DNA fragments for delivery of several genes of interest into the plant genome is one of the main technological challenges in plant synthetic biology. Despite several modular assembly methods developed in recent years, the plant biotechnology community has not widely adopted them yet, probably due to the lack of appropriate vectors and software tools. Here we present Plant X-tender, an extension of the highly efficient, scar-free and sequence-independent multigene assembly strategy AssemblX, based on overlap-depended cloning methods and rare-cutting restriction enzymes. Plant X-tender consists of a set of plant expression vectors and the protocols for most efficient cloning into the novel vector set needed for plant expression and thus introduces advantages of AssemblX into plant synthetic biology. The novel vector set covers different backbones and selection markers to allow full design flexibility. We have included ccdB counterselection, thereby allowing the transfer of multigene constructs into the novel vector set in a straightforward and highly efficient way. Vectors are available as empty backbones and are fully flexible regarding the orientation of expression cassettes and addition of linkers between them, if required. We optimised the assembly and subcloning protocol by testing different scar-less assembly approaches: the noncommercial SLiCE and TAR methods and the commercial Gibson assembly and NEBuilder HiFi DNA assembly kits. Plant X-tender was applicable even in combination with low efficient homemade chemically competent or electrocompetent Escherichia coli. We have further validated the developed procedure for plant protein expression by cloning two cassettes into the newly developed vectors and subsequently transferred them to Nicotiana benthamiana in a transient expression setup. Thereby we show that multigene constructs can be delivered into plant cells in a streamlined and highly efficient way. Our results will support faster

Plant X-tender: An extension of the AssemblX system for the assembly and expression of multigene constructs in plants.

Science.gov (United States)

Lukan, Tjaša; Machens, Fabian; Coll, Anna; Baebler, Špela; Messerschmidt, Katrin; Gruden, Kristina

2018-01-01

Cloning multiple DNA fragments for delivery of several genes of interest into the plant genome is one of the main technological challenges in plant synthetic biology. Despite several modular assembly methods developed in recent years, the plant biotechnology community has not widely adopted them yet, probably due to the lack of appropriate vectors and software tools. Here we present Plant X-tender, an extension of the highly efficient, scar-free and sequence-independent multigene assembly strategy AssemblX, based on overlap-depended cloning methods and rare-cutting restriction enzymes. Plant X-tender consists of a set of plant expression vectors and the protocols for most efficient cloning into the novel vector set needed for plant expression and thus introduces advantages of AssemblX into plant synthetic biology. The novel vector set covers different backbones and selection markers to allow full design flexibility. We have included ccdB counterselection, thereby allowing the transfer of multigene constructs into the novel vector set in a straightforward and highly efficient way. Vectors are available as empty backbones and are fully flexible regarding the orientation of expression cassettes and addition of linkers between them, if required. We optimised the assembly and subcloning protocol by testing different scar-less assembly approaches: the noncommercial SLiCE and TAR methods and the commercial Gibson assembly and NEBuilder HiFi DNA assembly kits. Plant X-tender was applicable even in combination with low efficient homemade chemically competent or electrocompetent Escherichia coli. We have further validated the developed procedure for plant protein expression by cloning two cassettes into the newly developed vectors and subsequently transferred them to Nicotiana benthamiana in a transient expression setup. Thereby we show that multigene constructs can be delivered into plant cells in a streamlined and highly efficient way. Our results will support faster

Lipid dip-pen nanolithography on self-assembled monolayers

International Nuclear Information System (INIS)

Gavutis, Martynas; Navikas, Vytautas; Rakickas, Tomas; Vaitekonis, Šarūnas; Valiokas, Ramūnas

2016-01-01

Dip-pen nanolithography (DPN) with lipids as an ink enables functional micro/nanopatterning on different substrates at high process speeds. However, only a few studies have addressed the influence of the physicochemical properties of the surface on the structure and phase behavior of DPN-printed lipid assemblies. Therefore, by combining the scanning probe and optical imaging techniques in this work we have analyzed lipid microdomain formation on the self-assembled monolayers (SAMs) on gold as well-defined model surfaces that displayed hydrophilic (protein-repellent) or hydrophobic (protein-adhesive) characteristics. We have found that on the tri(ethylene glycol)-terminated SAM the lipid ink transfer was fast (∼10 –1 μm 3 s −1 ), quasi-linear and it yielded unstable, sparsely packed lipid microspots. Contrary to this, on the methyl-terminated SAM the lipid transfer was ∼20 times slower, nonlinear, and the obtained stable dots of ∼1 μm in diameter consisted of lipid multilayers. Our comparative analysis indicated that the measured lipid transfer was consistent with the previously reported so-called polymer transfer model (Felts et al 2012, Nanotechnology 23 215301). Further on, by employing the observed distinct contrast in the DPN ink behavior we constructed confined lipid microdomains on pre-patterned SAMs, in which the lipids assembled either into monolayer or multilamellar phases. Such microdomains can be further utilized for lipid membrane mimetics in microarray and lab-on-a-chip device formats. (paper)

In vitro assembly of a prohead-like structure of the Rhodobacter capsulatus gene transfer agent

International Nuclear Information System (INIS)

Spano, Anthony J.; Chen, Frank S.; Goodman, Benjamin E.; Sabat, Agnes E.; Simon, Martha N.; Wall, Joseph S.; Correia, John J.; McIvor, Wilson; Newcomb, William W.; Brown, Jay C.; Schnur, Joel M.; Lebedev, Nikolai

2007-01-01

The gene transfer agent (GTA) is a phage-like particle capable of exchanging double-stranded DNA fragments between cells of the photosynthetic bacterium Rhodobacter capsulatus. Here we show that the major capsid protein of GTA, expressed in E. coli, can be assembled into prohead-like structures in the presence of calcium ions in vitro. Transmission electron microscopy (TEM) of uranyl acetate staining material and thin sections of glutaraldehyde-fixed material demonstrates that these associates have spherical structures with diameters in the range of 27-35 nm. The analysis of scanning TEM images revealed particles of mass ∼ 4.3 MDa, representing 101 ± 11 copies of the monomeric subunit. The establishment of this simple and rapid method to form prohead-like particles permits the GTA system to be used for genome manipulation within the photosynthetic bacterium, for specific targeted drug delivery, and for the construction of biologically based distributed autonomous sensors for environmental monitoring

The convergence of quantum-dot-mediated fluorescence resonance energy transfer and microfluidics for monitoring DNA polyplex self-assembly in real time

International Nuclear Information System (INIS)

Ho Yiping; Wang, T-H; Chen, Hunter H; Leong, Kam W

2009-01-01

We present a novel convergence of quantum-dot-mediated fluorescence resonance energy transfer (QD-FRET) and microfluidics, through which molecular interactions were precisely controlled and monitored using highly sensitive quantum-dot-mediated FRET. We demonstrate its potential in studying the kinetics of self-assembly of DNA polyplexes under laminar flow in real time with millisecond resolution. The integration of nanophotonics and microfluidics offers a powerful tool for elucidating the formation of polyelectrolyte polyplexes, which is expected to provide better control and synthesis of uniform and customizable polyplexes for future nucleic acid-based therapeutics.

Development of 3-D Flow Analysis Code for Fuel Assembly using Unstructured Grid System

Energy Technology Data Exchange (ETDEWEB)

Myong, Hyon Kook; Kim, Jong Eun; Ahn, Jong Ki; Yang, Seung Yong [Kookmin Univ., Seoul (Korea, Republic of)

2007-03-15

The flow through a nuclear rod bundle with mixing vanes are very complex and required a suitable turbulence model to be predicted accurately. Final objective of this study is to develop a CFD code for fluid flow and heat transfer analysis in a nuclear fuel assembly using unstructured grid system. In order to develop a CFD code for fluid flow and heat transfer analysis in a nuclear fuel assembly using unstructured grid system, the following researches are made: - Development of numerical algorithm for CFD code's solver - Grid and geometric connectivity data - Development of software(PowerCFD code) for fluid flow and heat transfer analysis in a nuclear fuel assembly using unstructured grid system - Modulation of software(PowerCFD code) - Development of turbulence model - Development of analysis module of RANS/LES hybrid models - Analysis of turbulent flow and heat transfer - Basic study on LES analysis - Development of main frame on pre/post processors based on GUI - Algorithm for fully-developed flow.

Development of 3-D Flow Analysis Code for Fuel Assembly using Unstructured Grid System

International Nuclear Information System (INIS)

Myong, Hyon Kook; Kim, Jong Eun; Ahn, Jong Ki; Yang, Seung Yong

2007-03-01

The flow through a nuclear rod bundle with mixing vanes are very complex and required a suitable turbulence model to be predicted accurately. Final objective of this study is to develop a CFD code for fluid flow and heat transfer analysis in a nuclear fuel assembly using unstructured grid system. In order to develop a CFD code for fluid flow and heat transfer analysis in a nuclear fuel assembly using unstructured grid system, the following researches are made: - Development of numerical algorithm for CFD code's solver - Grid and geometric connectivity data - Development of software(PowerCFD code) for fluid flow and heat transfer analysis in a nuclear fuel assembly using unstructured grid system - Modulation of software(PowerCFD code) - Development of turbulence model - Development of analysis module of RANS/LES hybrid models - Analysis of turbulent flow and heat transfer - Basic study on LES analysis - Development of main frame on pre/post processors based on GUI - Algorithm for fully-developed flow

Method and apparatus for dismantling and disposing of fuel assemblies

International Nuclear Information System (INIS)

Meuschke, R.E.; Schulties, J.R.

1985-01-01

This invention relates to apparatus and a method for dismantling, shearing, and compacting a fuel assembly frame skeleton. It uses an apparatus capable of hanging or being supported in the transfer canal of the spent fuel pit of the fuel handling building. This apparatus includes a bottom nozzle shear which is held under water to shear off the bottom nozzle and convey it to a scrap transfer bin. Then the remaining portion is brought to a skeleton compactor and shear, also held under water. The compacted skeleton is sheared into a number of smaller portions. After compacting and shearing, the individual portions are fed to the scrap transfer bin. The compacted and sheared skeleton assembly may be placed into a container that is adapted to hold four skeletons for off-site removal

Optical Assembly and Characterization System for Nano-Photonics Research

Science.gov (United States)

2016-03-01

freedoms) 3 (3) Carried out initial research work related to semiconductor membrane transfer printing. Based on the customer designed PDMS stamp...for optical characterization and membrane printing/assembly. The system has the following features: Micro-precision alignment with integrated 50 nm...a FL300-12 Automated Alignment System was acquired from Ficontec (USA) Corporation for optical characterization and membrane printing/assembly. The

Thermal Aspects Related to Power Assemblies

Directory of Open Access Journals (Sweden)

PLESCA, A.

2010-02-01

Full Text Available In many cases when a power assembly based on power semiconductors is used, catastrophic failure is the result of steep temperature gradient in the localized temperature distribution. Hence, an optimal heatsink design for certain industrial applications has become a real necessity. In this paper, the Pro/ENGINEER software with the thermal simulation integrated tool, Pro/MECHANICA, has been used for thermal study of a specific power semiconductor assembly. A series of steady-state and transient thermal simulations have been performed. The experimental tests have confirmed the simulation results. Therefore, the use of specific 3D modeling and simulation software allows to design special power semiconductor assemblies with a better thermal transfer between its heatsink and power electronic components at given operating conditions.

A conceptual design and structural stabilities of in-pit assembly tools for the completion of final sector assembly at tokamak hall

International Nuclear Information System (INIS)

Nam, K.O.; Park, H.K.; Kim, D.J.; Ahn, H.J.; Kim, K.K.; Im, K.; Shaw, R.

2010-01-01

The final assembly of main components of the International Thermonuclear Experimental Reactor (ITER) tokamak, Vacuum Vessel (VV) and Toroidal Field Coils (TFCs), is achieved by the sequential assembly of the nine sub-assembled 40 o sectors in tokamak pit. Each sub-assembled 40 o sector is composed of one VV 40 o sector, two TFCs, and in-between Vacuum Vessel Thermal Shield (VVTS) segments. Sub-assembly is carried out in the assembly building and then the sub-assembled sectors are transferred into tokamak pit, in sequence, to complete sector assembly. The role of in-pit assembly tool is to support and align the sub-assembled sectors in tokamak pit. It also plays the role of reference datum during assembly until the completion of main components assembly. Korea Domestic Agency (KO DA) has developed the conceptual design of most ITER purpose-built assembly tools under the collaboration with the ITER Organization. Among the conceptual designs carried out, this paper describes the function, the structure, the selected material and the design results of the in-pit assembly tools comprising central column, radial beams and their supports, TF inner supports and in-pit working floor. The results of structural analysis using ANSYS for the various loading cases are given as well. The resultant stresses and deflections turned out to fall within the allowable ranges.

Probing charge transfer dynamics in self-assembled monolayers by core hole clock approach

International Nuclear Information System (INIS)

Zharnikov, Michael

2015-01-01

This article reviews recent progress in the application of core hole clock approach in the framework of resonant Auger electron spectroscopy to the monomolecular assembles of alkyl, oligophenyl, and oligo(phenylene–ethynylene) based molecules on Au(1 1 1) substrates, referring mostly to the work by the author et al. The major goal was to study electron transfer (ET) dynamics in these systems serving as prototypes of molecular electronics (ME) devices. The ET pathway to the conductive substrate was unambiguously defined by resonant excitation of the nitrile tailgroup attached to the molecular backbone. Characteristic ET times within the femtosecond domain were determined, along with the attenuation factors for the ET dynamics, analogous to the case of the static transport. The above parameters were found to exhibit strong dependence on the character of the molecular orbital which mediates the ET process. In addition, certain spectral features, which can be associated with an inverse ET from the molecular backbone to the excitation site, were observed upon exchange of the nitrile group by strongly electronegative nitro moiety. The reported results represent a valuable input for theory and a certain potential for applications such as ME devices where optimization of ET can have significant technological impact.

Nuclear fuel assemblies

International Nuclear Information System (INIS)

Butterfield, R.S.; Garner, D.L.M.

1977-01-01

Reference is made to nuclear fuel assemblies designed for cooling on the 'tube-in-shell' principle in which the fuel is contained by a shell and is cooled by coolant passed through tubes extending through the shell. It has been proposed to employ coated particle fuel as a porous bed on the tube side and the bleed coolant from the tubes into direct contact with the fuel particles. In this way heat is extracted both by direct contact with the fuel and by heat transfer through the coolant tube walls. The system described aims to provide an improved structure of tube and shell for a fuel assembly of this kind and is particularly suitable for use in a gas cooled fast reactor, being able to withstand the neutron flux and high temperature conditions in these reactors. Constructional details are given. (U.K.)

Mechanical seal assembly

Science.gov (United States)

Kotlyar, Oleg M.

2001-01-01

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

Mechanical Seal Assembly

Energy Technology Data Exchange (ETDEWEB)

Kotlyar, Oleg M.

1999-06-18

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

Vectorial electron transfer for improved hydrogen evolution by mercaptopropionic-acid-regulated CdSe quantum-dots-TiO2 -Ni(OH)2 assembly.

Science.gov (United States)

Yu, Shan; Li, Zhi-Jun; Fan, Xiang-Bing; Li, Jia-Xin; Zhan, Fei; Li, Xu-Bing; Tao, Ye; Tung, Chen-Ho; Wu, Li-Zhu

2015-02-01

A visible-light-induced hydrogen evolution system based on a CdSe quantum dots (QDs)-TiO2 -Ni(OH)2 ternary assembly has been constructed under an ambient environment, and a bifunctional molecular linker, mercaptopropionic acid, is used to facilitate the interaction between CdSe QDs and TiO2 . This hydrogen evolution system works effectively in a basic aqueous solution (pH 11.0) to achieve a hydrogen evolution rate of 10.1 mmol g(-1)  h(-1) for the assembly and a turnover frequency of 5140 h(-1) with respect to CdSe QDs (10 h); the latter is comparable with the highest value reported for QD systems in an acidic environment. X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and control experiments demonstrate that Ni(OH)2 is an efficient hydrogen evolution catalyst. In addition, inductively coupled plasma optical emission spectroscopy and the emission decay of the assembly combined with the hydrogen evolution experiments show that TiO2 functions mainly as the electron mediator; the vectorial electron transfer from CdSe QDs to TiO2 and then from TiO2 to Ni(OH)2 enhances the efficiency for hydrogen evolution. The assembly comprises light antenna CdSe QDs, electron mediator TiO2 , and catalytic Ni(OH)2 , which mimics the strategy of photosynthesis exploited in nature and takes us a step further towards artificial photosynthesis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, transfer printing, electrical and optical properties, and applications of materials composed of self-assembled, aligned single-walled carbon nanotubes

Science.gov (United States)

Pint, Cary L.

Super growth of single-walled carbon nanotubes (SWNTs) has emerged as a unique method for synthesizing self-assembled, pristine, aligned SWNT materials composed of ultra-long (millimeter-long) nanotubes. This thesis focuses on novel routes of synthesizing such self-assembled SWNTs and the challenges that arise in integrating this material into next-generation applications. First of all, this work provides unique insight into growth termination of aligned SWNTs, emphasizing the mechanism that inhibits the growth of infinitely long nanotubes. Exhaustive real-time growth studies, combined with ex-situ and in-situ TEM characterization emphasizes that Ostwald ripening and subsurface diffusion of catalyst particles play a key role in growth termination. As a result, rational steps to solving this problem can enhance growth, and may ultimately lead to the meter or kilometer-long SWNTs that are necessary for a number of applications. In addition, other novel synthesis routes are discussed, such as the ability to form macroscopic fibrils of SWNTs, called "flying carpets" from 40 nm thick substrates, and the ability to achieve supergrowth of SWNTs that are controllably doped with nitrogen. In the latter case, molecular heterojunctions of doped and undoped sections in a single strand of ultralong SWNTs are demonstrated Secondly, as supergrowth is conducted on alumina coated SiO2 substrates, any applications will require that one can transfer the SWNTs to host surfaces with minimal processing. This work demonstrates a unique contact transfer route by which both patterned arrays of SWNTs, or homogenous SWNT carpets, can be transferred to any host surface. In the first case, the SWNTs are grown vertically aligned, and transferred in patterns of horizontally aligned SWNT. This transfer process relies on simple water-vapor etching of amorphous carbons at the catalyst following growth, and strong van der Waals adhesion of the high surface-area SWNT to host surfaces (gecko effect

Side-chain amino-acid-based pH-responsive self-assembled block copolymers for drug delivery and gene transfer.

Science.gov (United States)

Kumar, Sonu; Acharya, Rituparna; Chatterji, Urmi; De, Priyadarsi

2013-12-10

Developing safe and effective nanocarriers for multitype of delivery system is advantageous for several kinds of successful biomedicinal therapy with the same carrier. In the present study, we have designed amino acid biomolecules derived hybrid block copolymers which can act as a promising vehicle for both drug delivery and gene transfer. Two representative natural chiral amino acid-containing (l-phenylalanine and l-alanine) vinyl monomers were polymerized via reversible addition-fragmentation chain transfer (RAFT) process in the presence of monomethoxy poly(ethylene glycol) based macro-chain transfer agents (mPEGn-CTA) for the synthesis of well-defined side-chain amino-acid-based amphiphilic block copolymers, monomethoxy poly(ethylene glycol)-b-poly(Boc-amino acid methacryloyloxyethyl ester) (mPEGn-b-P(Boc-AA-EMA)). The self-assembled micellar aggregation of these amphiphilic block copolymers were studied by fluorescence spectroscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM). Potential applications of these hybrid polymers as drug carrier have been demonstrated in vitro by encapsulation of nile red dye or doxorubicin drug into the core of the micellar nanoaggregates. Deprotection of side-chain Boc- groups in the amphiphilic block copolymers subsequently transformed them into double hydrophilic pH-responsive cationic block copolymers having primary amino groups in the side-chain terminal. The DNA binding ability of these cationic block copolymers were further investigated by using agarose gel retardation assay and AFM. The in vitro cytotoxicity assay demonstrated their biocompatible nature and these polymers can serve as "smart" materials for promising bioapplications.

Model non-equilibrium molecular dynamics simulations of heat transfer from a hot gold surface to an alkylthiolate self-assembled monolayer.

Science.gov (United States)

Zhang, Yue; Barnes, George L; Yan, Tianying; Hase, William L

2010-05-07

Model non-equilibrium molecular dynamics (MD) simulations are presented of heat transfer from a hot Au {111} substrate to an alkylthiolate self-assembled monolayer (H-SAM) to assist in obtaining an atomic-level understanding of experiments by Wang et al. (Z. Wang, J. A. Carter, A. Lagutchev, Y. K. Koh, N.-H. Seong, D. G. Cahill, and D. D. Dlott, Science, 2007, 317, 787). Different models are considered to determine how they affect the heat transfer dynamics. They include temperature equilibrated (TE) and temperature gradient (TG) thermostat models for the Au(s) surface, and soft and stiff S/Au(s) models for bonding of the S-atoms to the Au(s) surface. A detailed analysis of the non-equilibrium heat transfer at the heterogeneous interface is presented. There is a short time temperature gradient within the top layers of the Au(s) surface. The S-atoms heat rapidly, much faster than do the C-atoms in the alkylthiolate chains. A high thermal conductivity in the H-SAM, perpendicular to the interface, results in nearly identical temperatures for the CH(2) and CH(3) groups versus time. Thermal-induced disorder is analyzed for the Au(s) substrate, the S/Au(s) interface and the H-SAM. Before heat transfer occurs from the hot Au(s) substrate to the H-SAM, there is disorder at the S/Au(s) interface and within the alkylthiolate chains arising from heat-induced disorder near the surface of hot Au(s). The short-time rapid heating of the S-atoms enhances this disorder. The increasing disorder of H-SAM chains with time results from both disorder at the Au/S interface and heat transfer to the H-SAM chains.

Tests of the RBMK-1500 reactor fuel assemblies in the Leningrad reactor

International Nuclear Information System (INIS)

Aden, V.C.; Varovin, I.A.; Vorontsov, B.A.

1981-01-01

Test of fuel assemblies of the RBMK-1500 reactor is conducted in the reactor of the Leningrad NPP unit 2 for proving the calculational values of critical power of the RBMK-1500 reactor fuel assemblies adopted in design. The experiment presupposes the maximal approximation of the fuel assembly operation parameters to the calculational critical parameters without bringing into the mode of heat transfer crisis. The experiments are carried out at 500, 850 and 900 MW(el) of the reactor. The maximal channel power made up 472 kW at 20.5 t/h coolant flow rate and 49% mass steam content at the outlet of the channel. It was concluded that there was supply up to the heat transfer crisis in all the investigated modes. Data of temperature measurings of the fuel element cans, readings of the devices of the failure control system of the fuel element cans and external inspection of the assemblies after the tests testify to it [ru

Reusable fluorescent sensor for captopril based on energy transfer from photoluminescent graphene oxide self-assembly multilayers to silver nanoparticles.

Science.gov (United States)

Sun, Xiangying; Liu, Bin; Li, Shuchun; Li, Fang

2016-05-15

In this work we designed a self-assembly multilayers, in which photoluminescent graphene oxide was employed as a fluorescence probe. This multilayers film can effectively recognize captopril by resonance energy transfer from graphite oxide to silver nanoparticles. A new interfacial sensing method for captopril with high signal to noise ratio was established, by means of that multilayers was quenched by silver nanoparticles and subsequently recovered by adding captopril. The linear relation between intensity and captopril concentration was good, and the detection limit was found to be 0.1578 μM. Also, this novel detection platform demonstrated intriguing reusable properties, and the sensor could be repeated more than ten times without obviously losing its sensing performance. Copyright © 2016 Elsevier B.V. All rights reserved.

Cytochrome oxidase assembly does not require catalytically active cytochrome C.

Science.gov (United States)

Barrientos, Antoni; Pierre, Danielle; Lee, Johnson; Tzagoloff, Alexander

2003-03-14

Cytochrome c oxidase (COX), the terminal enzyme of the mitochondrial respiratory chain, catalyzes the transfer of electrons from reduced cytochrome c to molecular oxygen. COX assembly requires the coming together of nuclear- and mitochondrial-encoded subunits and the assistance of a large number of nuclear gene products acting at different stages of maturation of the enzyme. In Saccharomyces cerevisiae, expression of cytochrome c, encoded by CYC1 and CYC7, is required not only for electron transfer but also for COX assembly through a still unknown mechanism. We have attempted to distinguish between a functional and structural requirement of cytochrome c in COX assembly. A cyc1/cyc7 double null mutant strain was transformed with the cyc1-166 mutant gene (Schweingruber, M. E., Stewart, J. W., and Sherman, F. (1979) J. Biol. Chem. 254, 4132-4143) that expresses stable but catalytically inactive iso-1-cytochrome c. The COX content of the cyc1/cyc7 double mutant strain harboring non-functional iso-1-cytochrome c has been characterized spectrally, functionally, and immunochemically. The results of these studies demonstrate that cytochrome c plays a structural rather than functional role in assembly of cytochrome c oxidase. In addition to its requirement for COX assembly, cytochrome c also affects turnover of the enzyme. Mutants containing wild type apocytochrome c in mitochondria lack COX, suggesting that only the folded and mature protein is able to promote COX assembly.

Homochiral Evolution in Self-Assembled Chiral Polymers and Block Copolymers.

Science.gov (United States)

Wen, Tao; Wang, Hsiao-Fang; Li, Ming-Chia; Ho, Rong-Ming

2017-04-18

The significance of chirality transfer is not only involved in biological systems, such as the origin of homochiral structures in life but also in man-made chemicals and materials. How the chiral bias transfers from molecular level (molecular chirality) to helical chain (conformational chirality) and then to helical superstructure or phase (hierarchical chirality) from self-assembly is vital for the chemical and biological processes in nature, such as communication, replication, and enzyme catalysis. In this Account, we summarize the methodologies for the examination of homochiral evolution at different length scales based on our recent studies with respect to the self-assembly of chiral polymers and chiral block copolymers (BCPs*). A helical (H*) phase to distinguish its P622 symmetry from that of normal hexagonally packed cylinder phase was discovered in the self-assembly of BCPs* due to the chirality effect on BCP self-assembly. Enantiomeric polylactide-containing BCPs*, polystyrene-b-poly(l-lactide) (PS-PLLA) and polystyrene-b-poly(d-lactide) (PS-PDLA), were synthesized for the examination of homochiral evolution. The optical activity (molecular chirality) of constituted chiral repeating unit in the chiral polylactide is detected by electronic circular dichroism (ECD) whereas the conformational chirality of helical polylactide chain can be explicitly determined by vibrational circular dichroism (VCD). The H* phases of the self-assembled polylactide-containing BCPs* can be directly visualized by 3D transmission electron microscopy (3D TEM) technique at which the handedness (hierarchical chirality) of the helical nanostructure is thus determined. The results from the ECD, VCD, and 3D TEM for the investigated chirality at different length scales suggest the homochiral evolution in the self-assembly of the BCPs*. For chiral polylactides, twisted lamellae in crystalline banded spherulite can be formed by dense packing scheme and effective interactions upon helical

Preconceptual design for a Monitored Retrievable Storage (MRS) transfer facility

International Nuclear Information System (INIS)

Woods, W.D.; Jowdy, A.K.; Smith, R.I.

1990-09-01

The contract between the DOE and the utilities specifies that the DOE will receive spent fuel from the nuclear utilities in 1998. This study investigates the feasibility of employing a simple Transfer Facility which can be constructed quickly, and operate while the full-scale MRS facilities are being constructed. The Transfer Facility is a hot cell designed only for the purpose of transferring spent fuel assemblies from the Office of Civilian Radioactive Waste Management (OCRWM) transport casks (shipped from the utility sites) into onsite concrete storage casks. No operational functions other than spent fuel assembly transfers and the associated cask handling, opening, and closing would be performed in this facility. Radioactive waste collected in the Transfer Facility during operations would be stored until the treatment facilities in the full-scale MRS facility became operational, approximately 2 years after the Transfer Facility started operation. An alternate wherein the Transfer Facility was the only waste handling building on the MRS site was also examined and evaluated. 6 figs., 26 tabs

Dry Transfer Systems for Used Nuclear Fuel

Energy Technology Data Exchange (ETDEWEB)

Brett W. Carlsen; Michaele BradyRaap

2012-05-01

The potential need for a dry transfer system (DTS) to enable retrieval of used nuclear fuel (UNF) for inspection or repackaging will increase as the duration and quantity of fuel in dry storage increases. This report explores the uses for a DTS, identifies associated general functional requirements, and reviews existing and proposed systems that currently perform dry fuel transfers. The focus of this paper is on the need for a DTS to enable transfer of bare fuel assemblies. Dry transfer systems for UNF canisters are currently available and in use for transferring loaded canisters between the drying station and storage and transportation casks.

Dual winch nuclear fuel transfer system providing more reliable fuel transfer during refueling operations

International Nuclear Information System (INIS)

Meuschke, R.E.; Harper, M.J.; Stefko, D.J.

1991-01-01

This paper describes a nuclear power plant having an auxiliary building, a containment building having the wall, a track extending through a transfer tube within the containment wall, and a fuel transfer system for moving fuel assemblies along the track between the auxiliary building side and the containment building side of the containment wall. It comprises: a car having wheels for movement along spaced rails of the track and further having a carrying basket for one or more fuel assemblies; winch means located on the auxiliary building side of the containment wall and above the water level existing over the track during refueling operations to drive the car along the track; first cable means and second cable means extending substantially vertically downward from the winch means to the tack level; first sheave means for directing the first and the second cable means substantially in the horizontal direction along the track; means for securing the first cable means to the car so that winch pulling force on the first cable means drives the car away from the containment building; second sheave means located near the containment end of the transfer tube

Robust forests of vertically aligned carbon nanotubes chemically assembled on carbon substrates.

Science.gov (United States)

Garrett, David J; Flavel, Benjamin S; Shapter, Joseph G; Baronian, Keith H R; Downard, Alison J

2010-02-02

Forests of vertically aligned carbon nanotubes (VACNTs) have been chemically assembled on carbon surfaces. The structures show excellent stability over a wide potential range and are resistant to degradation from sonication in acid, base, and organic solvent. Acid-treated single-walled carbon nanotubes (SWCNTs) were assembled on amine-terminated tether layers covalently attached to pyrolyzed photoresist films. Tether layers were electrografted to the carbon substrate by reduction of the p-aminobenzenediazonium cation and oxidation of ethylenediamine. The amine-modified surfaces were incubated with cut SWCNTs in the presence of N,N'-dicyclohexylcarbodiimide (DCC), giving forests of vertically aligned carbon nanotubes (VACNTs). The SWCNT assemblies were characterized by scanning electron microscopy, atomic force microscopy, and electrochemistry. Under conditions where the tether layers slow electron transfer between solution-based redox probes and the underlying electrode, the assembly of VACNTs on the tether layer dramatically increases the electron-transfer rate at the surface. The grafting procedure, and hence the preparation of VACNTs, is applicable to a wide range of materials including metals and semiconductors.

Fast & scalable pattern transfer via block copolymer nanolithography

DEFF Research Database (Denmark)

Li, Tao; Wang, Zhongli; Schulte, Lars

2015-01-01

A fully scalable and efficient pattern transfer process based on block copolymer (BCP) self-assembling directly on various substrates is demonstrated. PS-rich and PDMS-rich poly(styrene-b-dimethylsiloxane) (PS-b-PDMS) copolymers are used to give monolayer sphere morphology after spin-casting of s......A fully scalable and efficient pattern transfer process based on block copolymer (BCP) self-assembling directly on various substrates is demonstrated. PS-rich and PDMS-rich poly(styrene-b-dimethylsiloxane) (PS-b-PDMS) copolymers are used to give monolayer sphere morphology after spin...... on long range lateral order, including fabrication of substrates for catalysis, solar cells, sensors, ultrafiltration membranes and templating of semiconductors or metals....

Tailoring luminescence color conversion via affinitive co-assembly of glutamates appended with pyrene and naphthalene dicarboximide units.

Science.gov (United States)

Xing, Pengyao; Zhao, Zhuo; Hao, Aiyou; Zhao, Yanli

2016-01-21

Structural matching of two organic building blocks bearing glutamate units and different luminophores assembled into unilamellar nanovesicles in aqueous media through a co-assembly process. Aggregation-induced energy transfer took place in the co-assembled system, leading to controllable generation of multiple luminescence colors including white light.

Multi-purpose canister storage unit and transfer cask thermal analysis

International Nuclear Information System (INIS)

Montgomery, R.A.; Niemer, K.A.; Lindner, C.N.

1997-01-01

Spent Nuclear Fuel (SNF) generated at commercial nuclear power plants throughout the US is a concern because of continued delays in obtaining a safe, permanent disposal facility. Most utilities maintain their SNF in wet storage pools; however, after decades of use, many pools are filled to capacity. Unfortunately, DOE's proposed final repository at Yucca Mountain is at least 10 years from completion, and commercial power utilities have few options for SNF storage in the interim. The Multi-Purpose Canister (MPC) system, sponsored by DOE's Office of Civilian Radioactive Waste Management, is a viable solution to the interim storage problem. The system is designed for interim dry storage, transport, and ultimate disposal of commercial SNF. The MPC system consists of four separate components: an MPC, Transfer Cask, Storage Unit, and Transport Cask. The SNF assemblies are loaded and sealed inside the helium-filled steel MPC. Once sealed, the MPC is not reopened, eliminating the need to re-handle the individual spent fuel assemblies. The MPC is transferred, using the MPC Transfer Cask, into a cylindrical, reinforced-concrete Storage Unit for on-site dry storage. The MPC may be removed from the Storage Unit at any time and transferred into the MPC Transport Cask for transport to the final repository. This paper discusses the analytical approach used to evaluate the heat transfer characteristics of an MPC containing SNF assemblies in the MPC Transfer Cask and Storage Unit

Dexter energy transfer pathways.

Science.gov (United States)

Skourtis, Spiros S; Liu, Chaoren; Antoniou, Panayiotis; Virshup, Aaron M; Beratan, David N

2016-07-19

Energy transfer with an associated spin change of the donor and acceptor, Dexter energy transfer, is critically important in solar energy harvesting assemblies, damage protection schemes of photobiology, and organometallic opto-electronic materials. Dexter transfer between chemically linked donors and acceptors is bridge mediated, presenting an enticing analogy with bridge-mediated electron and hole transfer. However, Dexter coupling pathways must convey both an electron and a hole from donor to acceptor, and this adds considerable richness to the mediation process. We dissect the bridge-mediated Dexter coupling mechanisms and formulate a theory for triplet energy transfer coupling pathways. Virtual donor-acceptor charge-transfer exciton intermediates dominate at shorter distances or higher tunneling energy gaps, whereas virtual intermediates with an electron and a hole both on the bridge (virtual bridge excitons) dominate for longer distances or lower energy gaps. The effects of virtual bridge excitons were neglected in earlier treatments. The two-particle pathway framework developed here shows how Dexter energy-transfer rates depend on donor, bridge, and acceptor energetics, as well as on orbital symmetry and quantum interference among pathways.

Improvements in or relating to gripping means for handling nuclear reactor fuel assemblies

International Nuclear Information System (INIS)

Batjukov, V.I.; Vjugov, O.N.; Fadeev, A.I.; Shkhian, T.G.

1980-01-01

A gripping means for handling fuel assemblies, the heads of which are internally recessed to receive gripping jaws, forms part of a reactor refuelling machine and is telescopically accommodated within a manipulator tube of the machine. A through hole is provided to allow cooling medium to be passed through the fuel assemblies to remove afterheat when the gripping means is used to transfer assemblies from a reactor core to spent fuel storage sockets. (author)

Biologically Assembled Quantum Electronic Arrays

Science.gov (United States)

2013-06-07

Koh , Faxian Xiu, Xingchen Ye, Dong-Kyun Ko, Kang L. Wang, Cherie R. Kagan, Christopher B. Murray. Multiscale Periodic Assembly of Striped Nanocrystal...study is the LlM method (See M. T. Raman et al, Applied . Physics L etters 94, 042507, 2009). This method is a type of first-order reversal...Demonstrated graphene field- effect transistor: (top) optical Image of transferred graphene, (middle) Raman spectrum, (bottom) current voltage

Maximum thermal loading test of BWR fuel assembly

International Nuclear Information System (INIS)

Nakajima, Yoshitaka; Yoshimura, Kunihiro; Nakamura, Satoshi; Ishizuka, Takao.

1987-01-01

Various proving tests on the reliability of nuclear power plants have been conducted at the Nuclear Power Engineering Test Center and at the Japan Power Plant Engineering and Inspection Corporation. The tests were initiated at the request of the Ministry of International Trade and Industry (MITI). Toshiba undertook one of the proving tests on the reliability of nuclear fuel assembly; the maximum thermal loading test of BWR fuel assembly from the Nuclear Power Engineering Test Center. These tests are part of the proving tests mentioned above, and their purpose is to confirm the reliability of the thermal hydraulic engineering techniques. Toshiba has been engaged for the past nine years in the design, fabrication and testing of the equipment. For the project, a test model fuel assembly was used to measure the critical power of the BWR fuel assembly and the void and fluidity of the coolant. From the test results, it has been confirmed that the heat is transferred safely from the fuel assembly to the coolant in the BWR nuclear power plant. In addition, the propriety and reliability of the thermal hydraulic engineering techniques for the fuel assembly have been proved. (author)

Establishment of China Nuclear Fuel Assembly Database

International Nuclear Information System (INIS)

Chen Peng; Jin Yongli; Zhang Yingchao; Lu Huaquan; Chen Jianxin

2009-01-01

China Nuclear Fuel Assembly Database (CNFAD) is developed based on Oracle system. It contains the information of fuel assemblies in the stages of its design, fabrication and post irradiation (PIE). The structure of Browser Sever is adopted in the development of the software, which supports the HTTP protocol. It uses Java interface to transfer the codes from server to clients and make the sources of server and clients be utilized reasonably and sufficiently, so it can perform complicated tasks. Data in various stages of the fuel assemblies in Pressure Water Reactor (PWR), such as the design,fabrication, operation, and post irradiation examination, can be stored in this database. Data can be shared by multi users and communicated within long distances. By using CNFAD, the problem of decentralization of fuel data in China nuclear power plants will be solved. (authors)

Stereochemistry in subcomponent self-assembly.

Science.gov (United States)

Castilla, Ana M; Ramsay, William J; Nitschke, Jonathan R

2014-07-15

CONSPECTUS: As Pasteur noted more than 150 years ago, asymmetry exists in matter at all organization levels. Biopolymers such as proteins or DNA adopt one-handed conformations, as a result of the chirality of their constituent building blocks. Even at the level of elementary particles, asymmetry exists due to parity violation in the weak nuclear force. While the origin of homochirality in living systems remains obscure, as does the possibility of its connection with broken symmetries at larger or smaller length scales, its centrality to biomolecular structure is clear: the single-handed forms of bio(macro)molecules interlock in ways that depend upon their handednesses. Dynamic artificial systems, such as helical polymers and other supramolecular structures, have provided a means to study the mechanisms of transmission and amplification of stereochemical information, which are key processes to understand in the context of the origins and functions of biological homochirality. Control over stereochemical information transfer in self-assembled systems will also be crucial for the development of new applications in chiral recognition and separation, asymmetric catalysis, and molecular devices. In this Account, we explore different aspects of stereochemistry encountered during the use of subcomponent self-assembly, whereby complex structures are prepared through the simultaneous formation of dynamic coordinative (N → metal) and covalent (N═C) bonds. This technique provides a useful method to study stereochemical information transfer processes within metal-organic assemblies, which may contain different combinations of fixed (carbon) and labile (metal) stereocenters. We start by discussing how simple subcomponents with fixed stereogenic centers can be incorporated in the organic ligands of mononuclear coordination complexes and communicate stereochemical information to the metal center, resulting in diastereomeric enrichment. Enantiopure subcomponents were then

The Assembly-Activating Protein Promotes Stability and Interactions between AAV’s Viral Proteins to Nucleate Capsid Assembly

Directory of Open Access Journals (Sweden)

Anna C. Maurer

2018-05-01

Full Text Available Summary: The adeno-associated virus (AAV vector is a preferred delivery platform for in vivo gene therapy. Natural and engineered variations of the AAV capsid affect a plurality of phenotypes relevant to gene therapy, including vector production and host tropism. Fundamental to these aspects is the mechanism of AAV capsid assembly. Here, the role of the viral co-factor assembly-activating protein (AAP was evaluated in 12 naturally occurring AAVs and 9 putative ancestral capsid intermediates. The results demonstrate increased capsid protein stability and VP-VP interactions in the presence of AAP. The capsid’s dependence on AAP can be partly overcome by strengthening interactions between monomers within the assembly, as illustrated by the transfer of a minimal motif defined by a phenotype-to-phylogeny mapping method. These findings suggest that the emergence of AAP within the Dependovirus genus relaxes structural constraints on AAV assembly in favor of increasing the degrees of freedom for the capsid to evolve. : Maurer et al. describe a phenotype-to-phylogeny mapping strategy correlating phenotypic variation in AAVs to a reconstructed phylogeny, revealing capsid structure-function relationships relevant to that phenotype. Dependence on the viral co-factor AAP for capsid assembly is examined, and capsid functional motifs, in addition to mechanistic roles of AAP, are elucidated. Keywords: AAV, AAP, adeno-associated virus, capsid assembly, manufacturing, capsid, vector engineering, structure-function, gene therapy

Controlled short-linkage assembly of functional nano-objects

Energy Technology Data Exchange (ETDEWEB)

Chaudhary, Shilpi; Kamra, Tripta [Division of Pure and Applied Biochemistry, Lund University, Box 124, 221 00 Lund (Sweden); ENI AB, Malmö (Sweden); Division of Synchrotron Radiation Research, Lund University, Box 118, 221 00 Lund (Sweden); Uddin, Khan Mohammad Ahsan [Division of Pure and Applied Biochemistry, Lund University, Box 124, 221 00 Lund (Sweden); Snezhkova, Olesia [Division of Synchrotron Radiation Research, Lund University, Box 118, 221 00 Lund (Sweden); Jayawardena, H. Surangi N. [Department of Chemistry, University of Massachusetts Lowell, 1 University Ave., Lowell, MA 01854 (United States); Yan, Mingdi [Department of Chemistry, University of Massachusetts Lowell, 1 University Ave., Lowell, MA 01854 (United States); Department of Chemistry, KTH – Royal Institute of Technology, Teknikringen 30, S-10044 Stockholm (Sweden); Montelius, Lars [ENI AB, Malmö (Sweden); Schnadt, Joachim, E-mail: joachim.schnadt@sljus.lu.se [Division of Synchrotron Radiation Research, Lund University, Box 118, 221 00 Lund (Sweden); Ye, Lei, E-mail: lei.ye@tbiokem.lth.se [Division of Pure and Applied Biochemistry, Lund University, Box 124, 221 00 Lund (Sweden)

2014-05-01

Graphical abstract: - Highlights: • Fast photoconjugation of nanoparticles on surface. • Non-destructive feature guarantees intact function of nanoparticles. • Direct contact between nano-objects allows efficient photon and electron transfer. • Possibility of generating patterned nanoparticle assemblies on surface. • Open new opportunities for assembling chemical sensors. - Abstract: In this work, we report a method that allows the deterministic, photo-controlled covalent assembly of nanoparticles directly on surface. As a model system, we study the conjugation of molecularly imprinted polymer (MIP) nanoparticles on a glass surface and confirm that the immobilized nanoparticles maintain their molecular recognition functionality. The glass slide was first modified with perfluorophenylazide and then used to bind MIP nanoparticles under UV irradiation. After each step the surface was analyzed by water contact angle measurement, fluorescence microscopy, scanning electron microscopy, and/or synchrotron-based X-ray photoelectron spectroscopy. The MIP nanoparticles immobilized on the glass surface remained stable and maintained specific binding for the template molecule, propranolol. The method developed in this work allows MIP nanoparticles to be directly coupled to a flat surface, offering a straightforward means to construct robust chemical sensors. Using the reported photo conjugation method, it is possible to generate patterned assembly of nanoparticles using a photomask. Since perfluorophenylazide-based photochemistry works with all kinds of organic material, the method developed in this work is expected to enable immobilization of not only MIPs but also other kinds of organic and inorganic–organic core–shell particles for various applications involving photon or electron transfer.

Controlled short-linkage assembly of functional nano-objects

International Nuclear Information System (INIS)

Chaudhary, Shilpi; Kamra, Tripta; Uddin, Khan Mohammad Ahsan; Snezhkova, Olesia; Jayawardena, H. Surangi N.; Yan, Mingdi; Montelius, Lars; Schnadt, Joachim; Ye, Lei

2014-01-01

Graphical abstract: - Highlights: • Fast photoconjugation of nanoparticles on surface. • Non-destructive feature guarantees intact function of nanoparticles. • Direct contact between nano-objects allows efficient photon and electron transfer. • Possibility of generating patterned nanoparticle assemblies on surface. • Open new opportunities for assembling chemical sensors. - Abstract: In this work, we report a method that allows the deterministic, photo-controlled covalent assembly of nanoparticles directly on surface. As a model system, we study the conjugation of molecularly imprinted polymer (MIP) nanoparticles on a glass surface and confirm that the immobilized nanoparticles maintain their molecular recognition functionality. The glass slide was first modified with perfluorophenylazide and then used to bind MIP nanoparticles under UV irradiation. After each step the surface was analyzed by water contact angle measurement, fluorescence microscopy, scanning electron microscopy, and/or synchrotron-based X-ray photoelectron spectroscopy. The MIP nanoparticles immobilized on the glass surface remained stable and maintained specific binding for the template molecule, propranolol. The method developed in this work allows MIP nanoparticles to be directly coupled to a flat surface, offering a straightforward means to construct robust chemical sensors. Using the reported photo conjugation method, it is possible to generate patterned assembly of nanoparticles using a photomask. Since perfluorophenylazide-based photochemistry works with all kinds of organic material, the method developed in this work is expected to enable immobilization of not only MIPs but also other kinds of organic and inorganic–organic core–shell particles for various applications involving photon or electron transfer

Room temperature Coulomb blockade mediated field emission via self-assembled gold nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Wang, Fei [College of Physics and Electronics, Central South University, Changsha, Hunan 410073 (China); College of Science, National University of Defense Technology, Changsha, Hunan 410073 (China); Fang, Jingyue, E-mail: fjynudt@aliyun.com [College of Science, National University of Defense Technology, Changsha, Hunan 410073 (China); Chang, Shengli; Qin, Shiqiao; Zhang, Xueao [College of Science, National University of Defense Technology, Changsha, Hunan 410073 (China); Xu, Hui, E-mail: cmpxhg@csu.edu.cn [College of Physics and Electronics, Central South University, Changsha, Hunan 410073 (China)

2017-02-05

Coulomb blockade mediated field-emission current was observed in single-electron tunneling devices based on self-assembled gold nanoparticles at 300 K. According to Raichev's theoretical model, by fixing a proper geometric distribution of source, island and drain, the transfer characteristics can be well explained through a combination of Coulomb blockade and field emission. Coulomb blockade and field emission alternately happen in our self-assembled devices. The Coulomb island size derived from the experimental data is in good agreement with the average size of the gold nanoparticles used in the device. The integrated tunneling can be adjusted via a gate electrode. - Highlights: • The phenomenon of single-electron field emission in a transistor setting using self-assembled gold nanoparticles was investigated. • The transfer characteristics can be well explained by the model that is a combination of Coulomb blockage and field emission. • This transport mechanism is novel and may be used in many applications in field emission devices.

The Solid Waste Transfer Pit an FFTF [Fast Flux Test Facility] station for fuel and reflector transfer

International Nuclear Information System (INIS)

Milewski, A.J.; Thomson, J.D.

1985-01-01

This paper describes the design aspects of a proposed FFTF facility called the Solid Waste Transfer Pit (SWTP). This new facility will be used as a transfer station for reflectors and/or low decay heat fuel assemblies when movement from the Fuel Storage Facility for sodium removal and subsequent reprocessing is to be accomplished. The SWTP utilizes a shielded cell cover with an integral manually-operated gate valve for top loading of a transfer vessel. The cost-effective design discussed herein provides a practical approach using state-of-the-art concepts while assuring safe and reliable operation

Modular jet impingement assemblies with passive and active flow control for electronics cooling

Energy Technology Data Exchange (ETDEWEB)

Zhou, Feng; Dede, Ercan Mehmet; Joshi, Shailesh

2016-09-13

Power electronics modules having modular jet impingement assembly utilized to cool heat generating devices are disclosed. The modular jet impingement assemblies include a modular manifold having a distribution recess, one or more angled inlet connection tubes positioned at an inlet end of the modular manifold that fluidly couple the inlet tube to the distribution recess and one or more outlet connection tubes positioned at an outlet end of the modular manifold that fluidly coupling the outlet tube to the distribution recess. The modular jet impingement assemblies include a manifold insert removably positioned within the distribution recess and include one or more inlet branch channels each including an impinging slot and one or more outlet branch channels each including a collecting slot. Further a heat transfer plate coupled to the modular manifold, the heat transfer plate comprising an impingement surface including an array of fins that extend toward the manifold insert.

Calculation of Savannah River K Reactor Mark-22 assembly LOCA/ECS power limits

International Nuclear Information System (INIS)

Fischer, S.R.; Farman, R.F.; Birdsell, S.A.

1992-01-01

This paper summarizes the results of TRAC-PF1/MOD3 calculations of Mark-22 fuel assembly of loss-of-coolant accident/emergency cooling system (LOCA/ECS) power limits for the Savannah River Site (SRS) K Reactor. This effort was part of a larger effort undertaken by the Los Alamos National Laboratory for the US Department of Energy to perform confirmatory power limits calculations for the SRS K Reactor. A method using a detailed three-dimensional (3D) TRAC model of the Mark-22 fuel assembly was developed to compute LOCA/ECS power limits. Assembly power was limited to ensure that no point on the fuel assembly walls would exceed the local saturation temperature. The detailed TRAC model for the Mark-22 assembly consisted of three concentric 3D vessel components which simulated the two targets, two fuel tubes, and three main flow channels of the fuel assembly. The model included 100% eccentricity between the assembly annuli and a 20% power tilt. Eccentricity in the radial alignment of the assembly annuli arises because axial spacer ribs that run the length of the fuel and targets are used. Wall-shear, interfacial-shear, and wall heat-transfer correlations were developed and implemented in TRAC-PF1/MOD3 specifically for modeling flow and heat transfer in the narrow ribbed annuli encountered in the Mark-22 fuel assembly design. We established the validity of these new constitutive models using separate-effects benchmarks. TRAC system calculations of K Reactor indicated that the limiting ECS-phase accident is a double-ended guillonite break in a process water line at the pump discharge (i.e., a PDLOCA). The fuel assembly with the minimum cooling potential is identified from this system calculation. Detailed assembly calculations then were performed using appropriate boundary conditions obtained from this limiting system LOCA. Coolant flow rates and pressure boundary conditions were obtained from this system calculation and applied to the detailed assembly model

Hydrazine-mediated construction of nanocrystal self-assembly materials.

Science.gov (United States)

Zhou, Ding; Liu, Min; Lin, Min; Bu, Xinyuan; Luo, Xintao; Zhang, Hao; Yang, Bai

2014-10-28

Self-assembly is the basic feature of supramolecular chemistry, which permits to integrate and enhance the functionalities of nano-objects. However, the conversion of self-assembled structures to practical materials is still laborious. In this work, on the basis of studying one-pot synthesis, spontaneous assembly, and in situ polymerization of aqueous semiconductor nanocrystals (NCs), NC self-assembly materials are produced and applied to design high performance white light-emitting diode (WLED). In producing self-assembly materials, the additive hydrazine (N2H4) is curial, which acts as the promoter to achieve room-temperature synthesis of aqueous NCs by favoring a reaction-controlled growth, as the polyelectrolyte to weaken inter-NC electrostatic repulsion and therewith facilitate the one-dimensional self-assembly, and in particular as the bifunctional monomers to polymerize with mercapto carboxylic acid-modified NCs via in situ amidation reaction. This strategy is versatile for mercapto carboxylic acid-modified aqueous NCs, for example CdS, CdSe, CdTe, CdSe(x)Te(1-x), and Cd(y)Hg(1-y)Te. Because of the multisite modification with carboxyl, the NCs act as macromonomers, thus producing cross-linked self-assembly materials with excellent thermal, solvent, and photostability. The assembled NCs preserve strong luminescence and avoid unpredictable fluorescent resonance energy transfer, the main problem in design WLED from multiple NC components. These advantages allow the fabrication of NC-based WLED with high color rendering index (86), high luminous efficacy (41 lm/W), and controllable color temperature.

Heat transfer unit and method for prefabricated vessel

Science.gov (United States)

Tamburello, David A.; Kesterson, Matthew R; Hardy, Bruce J.

2017-11-07

Vessel assemblies, heat transfer units for prefabricated vessels, and methods for heat transfer prefabricated vessel are provided. A heat transfer unit includes a central rod, and a plurality of peripheral rods surrounding the central rod and connected to the central rod. The plurality of peripheral rods are movable between a first collapsed position and a second bowed position, wherein in the second bowed position a midpoint of each of the plurality of peripheral rods is spaced from the central rod relative to in the first position. The heat transfer unit further includes a heat transfer element connected to one of the plurality of peripheral rods.

Hybrid finite volume/ finite element method for radiative heat transfer in graded index media

Science.gov (United States)

Zhang, L.; Zhao, J. M.; Liu, L. H.; Wang, S. Y.

2012-09-01

The rays propagate along curved path determined by the Fermat principle in the graded index medium. The radiative transfer equation in graded index medium (GRTE) contains two specific redistribution terms (with partial derivatives to the angular coordinates) accounting for the effect of the curved ray path. In this paper, the hybrid finite volume with finite element method (hybrid FVM/FEM) (P.J. Coelho, J. Quant. Spectrosc. Radiat. Transf., vol. 93, pp. 89-101, 2005) is extended to solve the radiative heat transfer in two-dimensional absorbing-emitting-scattering graded index media, in which the spatial discretization is carried out using a FVM, while the angular discretization is by a FEM. The FEM angular discretization is demonstrated to be preferable in dealing with the redistribution terms in the GRTE. Two stiff matrix assembly schemes of the angular FEM discretization, namely, the traditional assembly approach and a new spherical assembly approach (assembly on the unit sphere of the solid angular space), are discussed. The spherical assembly scheme is demonstrated to give better results than the traditional assembly approach. The predicted heat flux distributions and temperature distributions in radiative equilibrium are determined by the proposed method and compared with the results available in other references. The proposed hybrid FVM/FEM method can predict the radiative heat transfer in absorbing-emitting-scattering graded index medium with good accuracy.

Hybrid finite volume/ finite element method for radiative heat transfer in graded index media

International Nuclear Information System (INIS)

Zhang, L.; Zhao, J.M.; Liu, L.H.; Wang, S.Y.

2012-01-01

The rays propagate along curved path determined by the Fermat principle in the graded index medium. The radiative transfer equation in graded index medium (GRTE) contains two specific redistribution terms (with partial derivatives to the angular coordinates) accounting for the effect of the curved ray path. In this paper, the hybrid finite volume with finite element method (hybrid FVM/FEM) (P.J. Coelho, J. Quant. Spectrosc. Radiat. Transf., vol. 93, pp. 89-101, 2005) is extended to solve the radiative heat transfer in two-dimensional absorbing-emitting-scattering graded index media, in which the spatial discretization is carried out using a FVM, while the angular discretization is by a FEM. The FEM angular discretization is demonstrated to be preferable in dealing with the redistribution terms in the GRTE. Two stiff matrix assembly schemes of the angular FEM discretization, namely, the traditional assembly approach and a new spherical assembly approach (assembly on the unit sphere of the solid angular space), are discussed. The spherical assembly scheme is demonstrated to give better results than the traditional assembly approach. The predicted heat flux distributions and temperature distributions in radiative equilibrium are determined by the proposed method and compared with the results available in other references. The proposed hybrid FVM/FEM method can predict the radiative heat transfer in absorbing-emitting-scattering graded index medium with good accuracy.

Deterministic assembly of linear gold nanorod chains as a platform for nanoscale applications

DEFF Research Database (Denmark)

Rey, Antje; Billardon, Guillaume; Loertscher, Emanuel

2013-01-01

target substrate, thus establishing a platform for a variety of nanoscale electronic and optical applications ranging from molecular electronics to optical and plasmonic devices. As a first example, electrical measurements are performed on contacted gold nanorod chains before and after their immersion......We demonstrate a method to assemble gold nanorods highly deterministically into a chain formation by means of directed capillary assembly. This way we achieved straight chains consisting of end-to-end aligned gold nanorods assembled in one specific direction with well-controlled gaps of similar...... to 6 nm between the individual constituents. We determined the conditions for optimum quality and yield of nanorod chain assembly by investigating the influence of template dimensions and assembly temperature. In addition, we transferred the gold nanorod chains from the assembly template onto a Si/SiO2...

Contribution of Metal Defects in the Assembly Induced Emission of Cu Nanoclusters

KAUST Repository

Wu, Zhennan

2017-03-20

Aggregation/assembly induced emission (AIE) has been observed for metal nanoclusters (NCs), but the origin of the enhanced emission is not fully understood, yet. In this work, the significant contribution of metal defects on AIE is revealed by engineering the self-assembly process of Cu NCs using ethanol. The presence of ethanol leads to a rapid assembly of NCs into ultrathin nanosheets, promoting the formation of metal defects-rich surface. Detailed studies and computer simulation confirm that the metal defects-rich nanosheets possess increased Cu(I)-to-Cu(0) ratio, which greatly influences ligand-to-metal-metal charge transfer and therewith facilitates the radiative relaxation of excitons. Consequently, the Cu NCs self-assembly nanosheets exhibit obvious emission enhancement.

Rapid electrostatics-assisted layer-by-layer assembly of near-infrared-active colloidal photonic crystals.

Science.gov (United States)

Askar, Khalid; Leo, Sin-Yen; Xu, Can; Liu, Danielle; Jiang, Peng

2016-11-15

Here we report a rapid and scalable bottom-up technique for layer-by-layer (LBL) assembling near-infrared-active colloidal photonic crystals consisting of large (⩾1μm) silica microspheres. By combining a new electrostatics-assisted colloidal transferring approach with spontaneous colloidal crystallization at an air/water interface, we have demonstrated that the crystal transfer speed of traditional Langmuir-Blodgett-based colloidal assembly technologies can be enhanced by nearly 2 orders of magnitude. Importantly, the crystalline quality of the resultant photonic crystals is not compromised by this rapid colloidal assembly approach. They exhibit thickness-dependent near-infrared stop bands and well-defined Fabry-Perot fringes in the specular transmission and reflection spectra, which match well with the theoretical calculations using a scalar-wave approximation model and Fabry-Perot analysis. This simple yet scalable bottom-up technology can significantly improve the throughput in assembling large-area, multilayer colloidal crystals, which are of great technological importance in a variety of optical and non-optical applications ranging from all-optical integrated circuits to tissue engineering. Copyright © 2016 Elsevier Inc. All rights reserved.

Experiences in transferring of AFA 3G fuel assembly fabrication

International Nuclear Information System (INIS)

Yang Xiaodong; Wu Zhiming; Luo Jiankang

2002-01-01

Implementation program is developed for the transferring of AFA 3G technology, together with the project management experts designated by Framatome Company, to facilitate the technology import under the guidance of strict program. Technical documents and quality insurance management documents are developed based on the full understanding of the information provided by Framatome to guide the fabrication of AFA 3G fuel elements. Technical requirement suggested by Framatome is adopted as much as possible, considering the practical process capability of YFP. The focus is the technology about fabrication difficulties in the AFA 3G technology, to insure the successful transfer of the AFA 3G fabrication technology

A 110 m long prototype helium transfer line for the HERA project

International Nuclear Information System (INIS)

Horvath, I.; Ming, P.; Von Burg, M.; Horlitz, G.; Sindt, H.

1986-01-01

A prototype helium transfer line of 110-m length was designed and constructed at SIN for the HERA project. This rendered a study of the assembly and handling processes as well as the determination of the heat losses into the transfer line. In this paper the transfer line structure is described and first results of heat transfer measurement for the specially developed super-insulation are presented

The State of the Art Ten Years After a State of the Art

DEFF Research Database (Denmark)

Sturm, Bob L.

2014-01-01

A decade has passed since the first review of research on a ``flagship application" of music information retrieval (MIR): the problem of music genre recognition (MGR). During this time, about 500 works addressing MGR have been published, and at least 10 campaigns have been run to evaluate MGR sys......, the problems of validity in evaluation also affect research in music emotion recognition and autotagging. We conclude by discussing the implications of our work for MGR and MIR in the next ten years....

Electrical Quality Assurance of the Superconducting Circuits during LHC Machine Assembly

CERN Document Server

Bozzini, D; Desebe, O; Mess, K H; Russenschuck, Stephan; Bednarek, M; Dworak, D; Górnicki, E; Jurkiewicz, P; Kapusta, P; Kotarba, A; Ludwin, J; Olek, S; Talach, M; Zieblinski, M; Klisch, M; Prochal, B

2008-01-01

Based on the LHC powering reference database, all-together 1750 superconducting circuits were connected in the various cryogenic transfer lines of the LHC machine. Testing the continuity, magnet polarity, and the quality of the electrical insulation were the main tasks of the Electrical Quality Assurance (ELQA) activities during the LHC machine assembly. With the assembly of the LHC now complete, the paper reviews the work flow, resources, and the qualification results including the different types of electrical non-conformities.

Blockages in LMFBR fuel assemblies: a review

International Nuclear Information System (INIS)

Han, J.T.; Fontana, M.H.

1977-01-01

Experimental and analytical investigations performed in the United States, Germany, Great Britain, and Japan on the effects of partial flow blockages in liquid-metal fast breeder reactor fuel assemblies are reviewed and the results presented. Generalized models are developed from experimental data obtained for blockages of various sizes, shapes, and porosity, with and without pins, utilizing water and sodium as the coolant. Generally, the recirculating flow in the wake behind a blockage is a relatively effective heat transfer mechanism. Experiments where sodium boiling was made to occur behind the blockages indicate that boiling is stable for the configurations tested; these results are predicted by analytical models. Blockages at the inlet of fuel assemblies tend to have insignificant effects in the fuel assembly unless flow is reduced grossly and therefore would be detectable. Blockages in the heat generating zone have to be quite large to cause sodium boiling under normal reactor operating conditions

Blockages in LMFBR fuel assemblies: a review

Energy Technology Data Exchange (ETDEWEB)

Han, J T; Fontana, M H

1977-01-01

Experimental and analytical investigations performed in the United States, Germany, Great Britain, and Japan on the effects of partial flow blockages in liquid-metal fast breeder reactor fuel assemblies are reviewed and the results presented. Generalized models are developed from experimental data obtained for blockages of various sizes, shapes, and porosity, with and without pins, utilizing water and sodium as the coolant. Generally, the recirculating flow in the wake behind a blockage is a relatively effective heat transfer mechanism. Experiments where sodium boiling was made to occur behind the blockages indicate that boiling is stable for the configurations tested; these results are predicted by analytical models. Blockages at the inlet of fuel assemblies tend to have insignificant effects in the fuel assembly unless flow is reduced grossly and therefore would be detectable. Blockages in the heat generating zone have to be quite large to cause sodium boiling under normal reactor operating conditions.

Influence of radiation heat transfer during a severe accident

Energy Technology Data Exchange (ETDEWEB)

Cazares R, R. I.; Epinosa P, G.; Varela H, J. R.; Vazquez R, A. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, San Rafael Atlixco No. 186, Col. Vicentina, 09340 Ciudad de Mexico (Mexico); Polo L, M. A., E-mail: ricardo-cazares@hotmail.com [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Barragan No. 779, Col. Narvarte, 03020 Ciudad de Mexico (Mexico)

2016-09-15

The aim of this work is to determine the influence of the radiation heat transfer on an average fuel channel during a severe accident of a BWR nuclear power plant. The analysis considers the radiation heat transfer in a participating medium, where the gases inside the system participate in the radiation heat transfer. We consider the steam-water mixture as an isothermal gray gas, and the boundaries of the system as a gray diffuse isothermal surface for the clad and refractory surfaces for the rest, and consider the average fuel channel as an enclosure system. During a severe accident, generation and diffusion of hydrogen begin at high temperature range (1,273 to 2,100 K), and the fuel rod cladding oxidation, but the hydrogen generated do not participate in the radiation heat transfer because it does not have any radiation properties. The heat transfer process in the fuel assembly is considered with a reduced order model, and from this, the convection and the radiation heat transfer is introduced in the system. In this paper, a system with and without the radiation heat transfer term was calculated and analyzed in order to obtain the influence of the radiation heat transfer on the average fuel channel. We show the behavior of radiation heat transfer effects on the temporal evolution of the hydrogen concentration and temperature profiles in a fuel assembly, where a stream of steam is flowing. Finally, this study is a practical complement for more accurate modeling of a severe accident analysis. (Author)

Influence of radiation heat transfer during a severe accident

International Nuclear Information System (INIS)

Cazares R, R. I.; Epinosa P, G.; Varela H, J. R.; Vazquez R, A.; Polo L, M. A.

2016-09-01

The aim of this work is to determine the influence of the radiation heat transfer on an average fuel channel during a severe accident of a BWR nuclear power plant. The analysis considers the radiation heat transfer in a participating medium, where the gases inside the system participate in the radiation heat transfer. We consider the steam-water mixture as an isothermal gray gas, and the boundaries of the system as a gray diffuse isothermal surface for the clad and refractory surfaces for the rest, and consider the average fuel channel as an enclosure system. During a severe accident, generation and diffusion of hydrogen begin at high temperature range (1,273 to 2,100 K), and the fuel rod cladding oxidation, but the hydrogen generated do not participate in the radiation heat transfer because it does not have any radiation properties. The heat transfer process in the fuel assembly is considered with a reduced order model, and from this, the convection and the radiation heat transfer is introduced in the system. In this paper, a system with and without the radiation heat transfer term was calculated and analyzed in order to obtain the influence of the radiation heat transfer on the average fuel channel. We show the behavior of radiation heat transfer effects on the temporal evolution of the hydrogen concentration and temperature profiles in a fuel assembly, where a stream of steam is flowing. Finally, this study is a practical complement for more accurate modeling of a severe accident analysis. (Author)

Comparison of fuel assemblies in lead cooled fast reactors

Energy Technology Data Exchange (ETDEWEB)

Perez, A.; Sanchez, H.; Aguilar, L.; Espinosa P, G., E-mail: alejandria.peval@gmail.com [Universidad Autonoma Metropolitana, Unidad Iztapalapa, San Rafael Atlixco No. 186, Col. Vicentina, 09340 Ciudad de Mexico (Mexico)

2016-09-15

This paper presents a comparison of the thermal-fluid processes in the core, fuel heat transfer, and thermal power between two fuel assemblies: square and hexagonal, in a lead-cooled fast reactor (Lfr). A multi-physics reduced order model for the analysis of Lfr single channel is developed in this work. The work focused on a coupling between process of neutron kinetic, fuel heat transfer process and thermal-fluid, in a single channel. The thermal power is obtained from neutron point kinetics model, considering a non-uniform power distribution. The analysis of the processes of thermal-fluid considers thermal expansion effects. The transient heat transfer in fuel is carried out in an annular geometry, and one-dimensional in radial direction for each axial node. The results presented in comparing these assemblies consider the temperature field in the fuel, in the thermal fluid and under steady state, and transient conditions. Transients consider flow of coolant and inlet temperature of coolant. The mathematical model of Lfr considers three main modules: the heat transfer in the annular fuel, the power generation with feedback effects on neutronic, and the thermal-fluid in the single channel. The modeling of nuclear reactors in general, the coupling is crucial by the feedback between the neutron processes with fuel heat transfer, and thermo-fluid, where is very common the numerical instabilities, after all it has to refine the model to achieve the design data. In this work is considered as a reference the ELSY reactor for the heat transfer analysis in the fuel and pure lead properties for analyzing the thermal-fluid. The results found shows that the hexagonal array has highest temperature in the fuel, respect to square array. (Author)

Comparison of fuel assemblies in lead cooled fast reactors

International Nuclear Information System (INIS)

Perez, A.; Sanchez, H.; Aguilar, L.; Espinosa P, G.

2016-09-01

This paper presents a comparison of the thermal-fluid processes in the core, fuel heat transfer, and thermal power between two fuel assemblies: square and hexagonal, in a lead-cooled fast reactor (Lfr). A multi-physics reduced order model for the analysis of Lfr single channel is developed in this work. The work focused on a coupling between process of neutron kinetic, fuel heat transfer process and thermal-fluid, in a single channel. The thermal power is obtained from neutron point kinetics model, considering a non-uniform power distribution. The analysis of the processes of thermal-fluid considers thermal expansion effects. The transient heat transfer in fuel is carried out in an annular geometry, and one-dimensional in radial direction for each axial node. The results presented in comparing these assemblies consider the temperature field in the fuel, in the thermal fluid and under steady state, and transient conditions. Transients consider flow of coolant and inlet temperature of coolant. The mathematical model of Lfr considers three main modules: the heat transfer in the annular fuel, the power generation with feedback effects on neutronic, and the thermal-fluid in the single channel. The modeling of nuclear reactors in general, the coupling is crucial by the feedback between the neutron processes with fuel heat transfer, and thermo-fluid, where is very common the numerical instabilities, after all it has to refine the model to achieve the design data. In this work is considered as a reference the ELSY reactor for the heat transfer analysis in the fuel and pure lead properties for analyzing the thermal-fluid. The results found shows that the hexagonal array has highest temperature in the fuel, respect to square array. (Author)

Detailed disc assembly temperature prediction: comparison between CFD and simplified engineering methods

CSIR Research Space (South Africa)

Snedden, Glen C

2003-09-01

Full Text Available Institute of Aeronautics and Astronautics Inc. All rights reserved. DETAILED DISC ASSEMBLY TEMPERATURE PREDICTION: COMPARISON BETWEEN CFD AND SIMPLIFIED ENGINEERING METHODS ISABE-2005-1130 Glen Snedden, Thomas Roos and Kavendra Naidoo CSIR, Defencetek... transfer and conduction code (Gaugler, 1978) Taw Adiabatic Wall Temperature y+ Near wall Reynolds number Introduction In order to calculate life degradation of gas turbine disc assemblies, it is necessary to model the transient thermal and mechanical...

Californium source transfer

International Nuclear Information System (INIS)

Wallace, C.R.

1995-01-01

In early 1995, the receipt of four sealed californium-252 sources from Oak Ridge National Lab was successfully accomplished by a team comprised of Radiological Engineering, Radiological Operations and Health Physics Instrumentation personnel. A procedure was developed and walked-down by the participants during a Dry Run Evolution. Several special tools were developed during the pre-planning phases of the project which reduced individual and job dose to minimal levels. These included a mobile lifting device for attachment of a transfer ball valve assembly to the undercarriage of the Cannonball Carrier, a transfer tube elbow to ensure proper angle of the source transfer tube, and several tools used during emergency response for remote retrieval and handling of an unshielded source. Lessons were learned in the areas of contamination control, emergency preparedness, and benefits of thorough pre-planning, effectiveness of locally creating and designing special tools to reduce worker dose, and methods of successfully accomplishing source receipt evolutions during extreme or inclement weather

Waste Handling Equipment Development Test and Evaluation Study

International Nuclear Information System (INIS)

R.L. Tome

1998-01-01

The purpose of this study is to identify candidate Monitored Geologic Repository (MGR) surface waste handling equipment for development testing. This study will also identify strategies for performing the development tests. Development testing shall be implemented to support detail design and reduce design risks. Development testing shall be conducted to confirm design concepts, evaluate alternative design concepts, show the availability of needed technology, and provide design documentation. The candidate equipment will be selected from MGR surface waste handling equipment that is the responsibility of the Management and Operating Contractor (M and O) Surface Design Department. The equipment identified in this study is based on Viability Assessment (VA) design. The ''Monitored Geologic Repository Test and Evaluation Plan'' (MGR T and EP), Reference 5.1, was used as a basis for this study. The MGR T and EP reflects the extent of test planning and analysis that can be conducted, given the current status of the MGR requirements and latest VA design information. The MGR T and EP supports the appropriate sections in the license application (LA) in accordance with 10 CFR 60.2 1(c)(14). The MGR T and EP describes the following test activities: site characterization to confirm, by test and analysis, the suitability of the Yucca Mountain site for housing a geologic repository; development testing to investigate and document design concepts to reduce risk; qualification testing to verify equipment compliance with design requirements, specifications, and regulatory requirements; system testing to validate compliance with MGR requirements, which include the receipt, handling, retrieval, and disposal of waste; periodic performance testing to verify preclosure requirements and to demonstrate safe and reliable MGR operation; and performance confirmation modeling, testing, and analysis to verify adherence to postclosure regulatory requirements. Development test activities can be

Status of Conceptual Design Progress for ITER Sector Sub-assembly Tools

Energy Technology Data Exchange (ETDEWEB)

Nam, Kyoung O; Park, Hyun Ki; Kim, Dong Jin [National Fusion Research Institute, Daejeon (Korea, Republic of); Lee, Jae Hyuk; Kim, Kyung Kyu [SFA Engineering Corp., Changwon (Korea, Republic of); Im, Ki Hak; Robert, Shaw [ITER Organization, Paul lez Durance (France)

2010-05-15

The ITER (International Thermonuclear Experimental Reactor) Tokamak assembly tools are purpose-built tools to complete the ITER Tokamak machine which includes the cryostat and the components contained therein. Based on the design description document prepared by the ITER organization, Korea has carried out the conceptual design of assembly tools. The 40 .deg. sector assemblies sub-assembled at assembly hall are transferred to Tokamak hall using the lifting tool operated by Tokamak main cranes. In-pit assembly tools are the purpose-built assembly tools for the completion of final sector assembly at Tokamak hall. The 40 .deg. sector sub-assembly tools are composed of the upending tool, the sector sub-assembly tool, the sector lifting tool and the vacuum vessel support and bracing tools. The process of the ITER sector sub-assembly at assembly hall and status of research and development are described in this paper. The ITER Tokamak device is composed of 9 vacuum vessel (VV)/toroidal field coils (TFCs)/vacuum vessel thermal shields (VVTS) 40 .deg. sectors. Each VV/TFCs/VVTS 40 .deg. sector is made up of one 40 .deg. VV, two 20 .deg. TFCs and associated VVTS segments. The 40 .deg. sectors are sub-assembled at assembly hall respectively and then 9 sectors which sub-assembled at assembly hall are finally assembled at Tokamak hall. As a basic assembly component, the assembly strategy and tools for the 40 .deg. sector sub-assembly and final assembly at inpit should be developed to satisfy the basic assembly requirements of the ITER Tokamak device. Accordingly, the purpose-built assembly tools should be designed and manufactured considering assembly plan, available space, safety, easy operation, efficient maintenance, and so on. The 40 .deg. sector assembly tools are classified into 2 groups. One group is the sub-assembly tools including upending tool, lifting tool, sub-assembly tool, VV supports and bracing tools used at assembly hall and the other group is the in

Conceptual design of reactor assembly of prototype fast breeder reactor

International Nuclear Information System (INIS)

Selvaraj, A.; Balasubramaniyan, V.; Raghupathy, S.; Elango, D.; Sodhi, B.S.; Chetal, S.C.; Bhoje, S.B.

1996-01-01

The conceptual design of Reactor Assembly of 500 MWe Prototype Fast Breeder Reactor (as selected in 1985) was reviewed with the aim of 'simplification of design', 'Compactness of the reactor assembly' and 'ease in construction'. The reduction in size has been possible by incorporating concentric core arrangement, adoption of elastomer seals for Rotatable plugs, fuel handling with one transfer arm type mechanism, incorporation of mechanical sealing arrangement for IHX at the penetration in Inner vessel redan and reduction in number of components. The erection of the components has been made easier by adopting 'hanging' support for roof slab with associated changes in the safety vessel design. This paper presents the conceptual design of the reactor assembly components. (author). 8 figs, 2 tabs

Energy transfer and clustering of photosynthetic light-harvesting complexes in reconstituted lipid membranes

International Nuclear Information System (INIS)

Dewa, Takehisa; Sumino, Ayumi; Watanabe, Natsuko; Noji, Tomoyasu; Nango, Mamoru

2013-01-01

Highlights: ► Photosynthetic light-harvesting complexes were reconstituted into lipid membranes. ► Energy transfers between light-harvesting complexes were examined. ► Atomic force microscopy indicated cluster formation of light-harvesting complexes. ► Efficient energy transfer was observed for the clustered complexes in the membranes. - Abstract: In purple photosynthetic bacteria, light-harvesting complex 2 (LH2) and light harvesting/reaction centre core complex (LH1-RC) play the key roles of capturing and transferring light energy and subsequent charge separation. These photosynthetic apparatuses form a supramolecular assembly; however, how the assembly influences the efficiency of energy conversion is not yet clear. We addressed this issue by evaluating the energy transfer in reconstituted photosynthetic protein complexes LH2 and LH1-RC and studying the structures and the membrane environment of the LH2/LH1-RC assemblies, which had been embedded into various lipid bilayers. Thus, LH2 and LH1-RC from Rhodopseudomonas palustris 2.1.6 were reconstituted in phosphatidylglycerol (PG), phosphatidylcholine (PC), and phosphatidylethanolamine (PE)/PG/cardiolipin (CL). Efficient energy transfer from LH2 to LH1-RC was observed in the PC and PE/PG/CL membranes. Atomic force microscopy revealed that LH2 and LH1-RC were heterogeneously distributed to form clusters in the PC and PE/PG/CL membranes. The results indicated that the phospholipid species influenced the cluster formation of LH2 and LH1-RC as well as the energy transfer efficiency

Energy transfer and clustering of photosynthetic light-harvesting complexes in reconstituted lipid membranes

Energy Technology Data Exchange (ETDEWEB)

Dewa, Takehisa, E-mail: takedewa@nitech.ac.jp [Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Japan Science and Technology, PRESTO, 4-1-8 Honcho Kawaguchi, Saitama 332-0012 (Japan); Sumino, Ayumi; Watanabe, Natsuko; Noji, Tomoyasu [Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Nango, Mamoru, E-mail: nango@nitech.ac.jp [Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan)

2013-06-20

Highlights: ► Photosynthetic light-harvesting complexes were reconstituted into lipid membranes. ► Energy transfers between light-harvesting complexes were examined. ► Atomic force microscopy indicated cluster formation of light-harvesting complexes. ► Efficient energy transfer was observed for the clustered complexes in the membranes. - Abstract: In purple photosynthetic bacteria, light-harvesting complex 2 (LH2) and light harvesting/reaction centre core complex (LH1-RC) play the key roles of capturing and transferring light energy and subsequent charge separation. These photosynthetic apparatuses form a supramolecular assembly; however, how the assembly influences the efficiency of energy conversion is not yet clear. We addressed this issue by evaluating the energy transfer in reconstituted photosynthetic protein complexes LH2 and LH1-RC and studying the structures and the membrane environment of the LH2/LH1-RC assemblies, which had been embedded into various lipid bilayers. Thus, LH2 and LH1-RC from Rhodopseudomonas palustris 2.1.6 were reconstituted in phosphatidylglycerol (PG), phosphatidylcholine (PC), and phosphatidylethanolamine (PE)/PG/cardiolipin (CL). Efficient energy transfer from LH2 to LH1-RC was observed in the PC and PE/PG/CL membranes. Atomic force microscopy revealed that LH2 and LH1-RC were heterogeneously distributed to form clusters in the PC and PE/PG/CL membranes. The results indicated that the phospholipid species influenced the cluster formation of LH2 and LH1-RC as well as the energy transfer efficiency.

Improved inter-assembly heat transfer modeling under low flow conditions for the Super System Code (SSC)

International Nuclear Information System (INIS)

Horak, W.C.; Guppy, J.G.

1984-01-01

The Super System Code (SSC) was developed at the Brookhaven National Laboratory (BNL) for the thermal hydraulic analysis of natural circulation transients, operational transients, and other system wide transients in nuclear power plants. SSC is a generic, best estimate code that models the in-vessel components, heat transport loops, plant protection systems and plant control systems. SSC also simulates the balance of plant when interfaced with the MINET code. SSC has been validated against both numerical and experimental data bases and is now used by several outside users. An important area of interest in LMFBR transient analysis is the prediction of the response of the reactor core under low flow conditions, such as experienced during a natural circulation event. Under these circumstances there are many physical phenomena which must be modeled to provide an adequate representation by a computer code simulation. The present version of SSC contains numerous models which account for most of the major phenomena. However, one area where the present model in SSC is being improved is in the representation of heat transfer and buoyancy effects under low flow operation. To properly improve the present version, the addition of models to represent certain inter-assembly effects is required

Paul Lecoq assembles a read head made with special crystals for a PET (positron emission tomography) scanner. He is the initiator of the Crystal Clear collaboration, which aims to transfer crystals developed at CERN to applications in medical imaging.

CERN Multimedia

Maximilien Brice

2004-01-01

Paul Lecoq assembles a read head made with special crystals for a PET (positron emission tomography) scanner. He is the initiator of the Crystal Clear collaboration, which aims to transfer crystals developed at CERN to applications in medical imaging.

Numerical Study for Turbulent Heat Transfer in Helical Wired Sub-channel Flow Regime of Duct-less Assembly in SFR

International Nuclear Information System (INIS)

You, Byunghyun; Jeong, Yong Hoon

2014-01-01

A fuel assembly had hexagonal structure adjacent to 6 fuel assemblies, which influence to the target fuel assembly due to elimination of duct. For calculating the influence, 6 additional channels were generated between the adjacent fuel assemblies and cross flow model was applied to the channels. The adjacent fuel assemblies were analyzed and the results were used in the additional channel as boundary condition of the target fuel assembly. To design the specifications of duct-less assembly, modified or brand-new thermal-hydraulic methodology is needed which is using MATRA-LMR and CFD codes in this study. The MATRA-LMR is a sub-channel analysis code for LMR that has been developed in Korea Atomic Energy Research Institute. It is designed to analyze a fuel assembly with wire-wrap and duct structure. However, the duct-less core is not able to be analyzed by the MATRA-LMR which doesn't consider cross flow between the fuel assemblies and effect of grid spacer. The code need improvement by editing source code to eliminate effect of duct and analyze pressure drop and mixing between the sub-channels caused by grid spacer and cross flow between the fuel assemblies. To validate reformed pressure drop model and cross flow model in MATRA-LMR, CFD analysis is performed. For verifying the results of CFD, LMR subchannel experimental data is benchmarked which is done by ORNL. The verified CFD for thermalhydraulic analysis calculated pressure drop and mixing caused by grid spacer and cross flow between fuel assemblies

Effect of magnetic reconnection in stellar plasma

Science.gov (United States)

Hammoud, M.; El Eid, M.; Darwish, M.

2017-06-01

An important phenomenon in Astrophysics is the process of magnetic reconnection (MGR), which is envisaged to understand the solar flares, coronal mass ejection, interaction of the solar wind with the Earth’s magnetic field (so called geomagnetic storm) and other phenomena. In addition, it plays a role in the formation of stars. MGR involves topological change of a set of magnetic field lines leading to a new equilibrium configuration of lower magnetic energy. The MGR is basically described in the framework of the Maxwell’s equations linked to Navier-Stockes equations. Nevertheless, many details are still not understood. In this paper, we investigate the MGR process in the framework of the Magnetohydrodynamic (MHD) model of a single conducting fluid using a modern powerful computational tool (OpenFOAM). We will show that the MGR process takes place only if resistivity exists. However, despite the high conductivity of the plasma, resistivity becomes effective in a very thin layer generating sharp gradients of the magnetic field, and thus accelerating the reconnection process. The net effect of MGR is that magnetic energy is converted into thermal and kinetic energies leading to heating and acceleration of charged particles. The Sun’s coronal ejection is an example of the MGR process.

Unsupervised Typography Transfer

OpenAIRE

Sun, Hanfei; Luo, Yiming; Lu, Ziang

2018-01-01

Traditional methods in Chinese typography synthesis view characters as an assembly of radicals and strokes, but they rely on manual definition of the key points, which is still time-costing. Some recent work on computer vision proposes a brand new approach: to treat every Chinese character as an independent and inseparable image, so the pre-processing and post-processing of each character can be avoided. Then with a combination of a transfer network and a discriminating network, one typograph...

Supramolecular assembled three-dimensional graphene hybrids: Synthesis and applications in supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Ni, Lubin [College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, Jiangsu (China); Zhang, Wang [College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, Jiangsu (China); Graduate School of Convergence Science and Technology, Seoul National University, Seoul, 151-742 (Korea, Republic of); Wu, Zhen; Sun, Chunyu; Cai, Yin; Yang, Guang; Chen, Ming [College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, Jiangsu (China); Piao, Yuanzhe, E-mail: parkat9@snu.ac.kr [Graduate School of Convergence Science and Technology, Seoul National University, Seoul, 151-742 (Korea, Republic of); Diao, Guowang, E-mail: gwdiao@yzu.edu.cn [College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, Jiangsu (China)

2017-02-28

Graphical abstract: Supramolecular assembled three-dimensdional graphene-based architectures were built by host-guest interactions of β-cyclodextrin polymers(β-CDPs) with adamantine end-capped poly(ethylene oxide) polymer linker (PEG-AD), exhibit significantly improved electrochemical performances of supercapacitor in terms of high specific capacitance, remarkable rate capability, and excellent cycling stability compared to pristine reduced graphene oxide. - Highlights: • Supramolecular assembled three-Dimensional (3D) graphene was first fabricated by host-guest interactions of β-CDPs with PEG-AD linkers. • The incorporation of PEG-AD linker into rGO sheets can provide efficient 3D electron transfer pathways and ion diffusion channels. • The 3D self-assembled graphene exhibits high specific capacitance, remarkable rate capability, and excellent cycling stability. • This study shed new lights to design 3D self-assembled graphene materials and their urgent applications in energy storage. - Abstract: Graphene-based materials have received worldwide attention in the focus of forefront energy storage investigations. Currently, the design of novel three-dimensional (3D) graphene structures with high energy capability, superior electron and ion conductivity, and robust mechanical flexibility is still a great challenge. Herein, we have successfully demonstrated a novel approach to fabricate 3D assembled graphene through the supramolecular interactions of β-cyclodextrin polymers (β-CDP) with an adamantine end-capped poly(ethylene oxide) polymer linker (PEG-AD). The incorporation of PEG-AD linker into rGO sheets increased the interlayer spacing of rGO sheets to form 3D graphene materials, which can provide efficient 3D electron transfer pathways and ion diffusion channels, and facilitate the infiltration of gel electrolyte. The as-prepared 3D self-assembled graphene materials exhibit significantly improved electrochemical performances of supercapacitor in terms

Supramolecular assembled three-dimensional graphene hybrids: Synthesis and applications in supercapacitors

International Nuclear Information System (INIS)

Ni, Lubin; Zhang, Wang; Wu, Zhen; Sun, Chunyu; Cai, Yin; Yang, Guang; Chen, Ming; Piao, Yuanzhe; Diao, Guowang

2017-01-01

Graphical abstract: Supramolecular assembled three-dimensdional graphene-based architectures were built by host-guest interactions of β-cyclodextrin polymers(β-CDPs) with adamantine end-capped poly(ethylene oxide) polymer linker (PEG-AD), exhibit significantly improved electrochemical performances of supercapacitor in terms of high specific capacitance, remarkable rate capability, and excellent cycling stability compared to pristine reduced graphene oxide. - Highlights: • Supramolecular assembled three-Dimensional (3D) graphene was first fabricated by host-guest interactions of β-CDPs with PEG-AD linkers. • The incorporation of PEG-AD linker into rGO sheets can provide efficient 3D electron transfer pathways and ion diffusion channels. • The 3D self-assembled graphene exhibits high specific capacitance, remarkable rate capability, and excellent cycling stability. • This study shed new lights to design 3D self-assembled graphene materials and their urgent applications in energy storage. - Abstract: Graphene-based materials have received worldwide attention in the focus of forefront energy storage investigations. Currently, the design of novel three-dimensional (3D) graphene structures with high energy capability, superior electron and ion conductivity, and robust mechanical flexibility is still a great challenge. Herein, we have successfully demonstrated a novel approach to fabricate 3D assembled graphene through the supramolecular interactions of β-cyclodextrin polymers (β-CDP) with an adamantine end-capped poly(ethylene oxide) polymer linker (PEG-AD). The incorporation of PEG-AD linker into rGO sheets increased the interlayer spacing of rGO sheets to form 3D graphene materials, which can provide efficient 3D electron transfer pathways and ion diffusion channels, and facilitate the infiltration of gel electrolyte. The as-prepared 3D self-assembled graphene materials exhibit significantly improved electrochemical performances of supercapacitor in terms

Study of heat and mass transfer phenomena in fuel assembly models under accident conditions

International Nuclear Information System (INIS)

Yefanov, A.D.; Kalyakin, C.G.; Loshchinin, V.M.; Pomet'ko, R.S.; Sergeev, V.V.; Shumsky, R.V.

1996-01-01

The majority of the material in support of the thermal - hydraulic safety of WWER core was obtained on single - assembly models containing a relatively small number of elements - heater rods. Upgrading the requirements to the reactor safety leads to the necessity for studying phenomena in channels representing the cross - sectional core dimensions and non - uniform radial power generation. Under such conditions, the contribution of natural convection can be significant in some core zones, including the occurrence of reverse flows and interchannel instability. These phenomena can have an important influence on heat transfer processes. Such influence is especially drastical under accident conditions associated with ceasing the forced circulation over the circuit. A number of urgent reactor safety problems at low operating parameters is related with the computer code verification and certification. One of the important trends in the reactor safety research is concerned with the rod bundle reflooding and verificational calculations of this phenomenon. To assess the water cooled reactor safety, the best fit computer codes are employed, which make it possible to simulate accident and transient operating conditions in a reactor installation. One of the most widely known computer codes is the RELAP5/MOD3 Code. The paper presents the comparison of the results calculated using this computer code with the test data on 4 - rod bundle quenching, which were obtained at the SSCRF-IPPE. Recently, the investigations on the steam - zirconium reaction kinetics have been performed at the SSCFR-IPPE and are being presently performed for the purpose of developing new and verifying available computer codes. (author). 3 refs, 6 figs

Thermal-hydraulic and neutron-physical characteristics of a new SCWR fuel assembly

International Nuclear Information System (INIS)

Liu, X.J.; Cheng, X.

2009-01-01

A new fuel assembly design for a thermal supercritical water cooled reactor (SCWR) core is proposed. Compared to the existing fuel assemblies, the present fuel assembly has two-rows of fuel rods between the moderator channels, to achieve a more uniform moderation for all fuel rod cells, and subsequently, a more uniform radial power distribution. In addition, a neutron-kinetics/thermal-hydraulics coupling method is developed, to analyze the neutron-physical and thermal-hydraulic behavior of the fuel assembly designs. This coupling method is based on the sub-channel analysis code COBRA-IV for thermal-hydraulics and the neutron-kinetics code SKETCH-N for neutron-physics. Both the COBRA-IV code and the SKETCH-N code are accordingly modified. An interface is established for the data transfer between these two codes. This coupling method is applied to both the one-row fuel assemblies (previous design) and the two-row fuel assemblies (present design). The performance of the two types of fuel assemblies is compared. The results show clearly that the two-row fuel assembly has more favorable neutron-physical and thermal-hydraulic characteristics than the one-row fuel assembly. The effect of various parameters on the fuel assembly performance is discussed. The coupling method is proven to be well suitable for further applications to SCWR fuel assembly design analysis

Proton triggered circularly polarized luminescence in orthogonal- and co-assemblies of chiral gelators with achiral perylene bisimide.

Science.gov (United States)

Han, Dongxue; Han, Jianlei; Huo, Shengwei; Qu, Zuoming; Jiao, Tifeng; Liu, Minghua; Duan, Pengfei

2018-05-29

The orthogonal- or co-assembly of achiral perylene bisimide (PBI) with chiral gelators can be regulated by solvents. While the coassembly leads to the formation of chiroptical nanofibers through chirality transfer, the orthogonal assemblies could not. Moreover, protonation on the coassembled nanofibers could light up the circularly polarized luminescence (CPL).

Self-Assembled Polystyrene Beads for Templated Covalent Functionalization of Graphitic Substrates Using Diazonium Chemistry.

Science.gov (United States)

Van Gorp, Hans; Walke, Peter; Bragança, Ana M; Greenwood, John; Ivasenko, Oleksandr; Hirsch, Brandon E; De Feyter, Steven

2018-04-11

A network of self-assembled polystyrene beads was employed as a lithographic mask during covalent functionalization reactions on graphitic surfaces to create nanocorrals for confined molecular self-assembly studies. The beads were initially assembled into hexagonal arrays at the air-liquid interface and then transferred to the substrate surface. Subsequent electrochemical grafting reactions involving aryl diazonium molecules created covalently bound molecular units that were localized in the void space between the nanospheres. Removal of the bead template exposed hexagonally arranged circular nanocorrals separated by regions of chemisorbed molecules. Small molecule self-assembly was then investigated inside the resultant nanocorrals using scanning tunneling microscopy to highlight localized confinement effects. Overall, this work illustrates the utility of self-assembly principles to transcend length scale gaps in the development of hierarchically patterned molecular materials.

Use of virtual steam generator cassette for tube spatial design and SGC assembling procedure

International Nuclear Information System (INIS)

Kim, Y. W.; Kim, J. I.; Ji, S. K.

2003-01-01

A method of determining spatial arrangement of tube connection and assembling procedure of once-through helical steam generator cassette utilizing three dimensional virtual steam generator cassette has been developed on the basis of recent 3-D modelling technology. One ends of the steam generator tubes are connected to the module feed water header and the other sides are connected to the module steam header. Due to the complex geometry of tube arrangement, it is very difficult to connect the tubes to the module headers without the help of a physical engineering mock up. A comparative study has been performed at each design step for the tube arrangement and heat transfer area. Heat transfer area computed from thermal sizing was 4% less than that of measured. Heat transfer area calculated from the virtual steam generator cassette mock up has only 0.2% difference with that of measured. Assembling procedure of the steam generator cassette also, can be developed in the design stage

Atomic layer deposition assisted pattern transfer technology for ultra-thin block copolymer films

Energy Technology Data Exchange (ETDEWEB)

Chen, Wenhui; Luo, Jun; Meng, Lingkuan; Li, Junjie; Xiang, Jinjuan; Li, Junfeng; Wang, Wenwu; Chen, Dapeng; Ye, Tianchun; Zhao, Chao

2016-08-31

As an emerging developing technique for next-generation lithography, directed self-assembly (DSA) of block copolymer (BCP) has attracted numerous attention and has been a potential alternative to supplement the intrinsic limitations of conventional photolithography. In this work, the self-assembling properties of a lamellar diblock copolymer poly(styrene-b-methylmethacrylate) (PS-b-PMMA, 22k-b-22k, L{sub 0} = 25 nm) on Si substrate and an atomic layer deposition (ALD)-assisted pattern transfer technology for the application of DSA beyond 16/14 nm complementary metal oxide semiconductor (CMOS) technology nodes, were investigated. Firstly, two key processing parameters of DSA, i.e. annealing temperatures and durations of BCP films, were optimized to achieve low defect density and high productivity. After phase separation of BCP films, self-assembling patterns of low defect density should be transferred to the substrate. However, due to the nano-scale thickness and the weak resistance of BCP films to dry etching, it is nearly impossible to transfer the BCP patterns directly to the substrate. Therefore, an ALD-based technology was explored in this work, in which deposited Al{sub 2}O{sub 3} selectively reacts with PMMA blocks thus hardening the PMMA patterns. After removing PS blocks by plasma etching, hardened PMMA patterns were left and transferred to underneath SiO{sub 2} hard mask layer. Using this patterned hard mask, nanowire array of 25 nm pitch were realized on Si substrate. From this work, a high-throughput DSA baseline flow and related ALD-assisted pattern transfer technique were developed and proved to have good capability with the mainstream CMOS technology. - Highlights: • Optimization on self-assembly process for high productivity and low defectivity • Enhancement of etching ratio and resistance by atomic layer deposition (ALD) • A hard mask was used for pattern quality improvement and contamination control.

Apparatus and method for assembling fuel elements

International Nuclear Information System (INIS)

Arya, S.P.

1978-01-01

A nuclear fuel element assembling method and apparatus is preferably operable under programmed control unit to receive fuel rods from storage, arrange them into axially aligned stacks of closely monitored length, and transfer the stacks of fuel rods to a loading device for insertion into longitudinal passages in the fuel elements. In order to handle large numbers of one or more classifications of fuel rods or other cylindrical parts, the assembling apparatus includes at least two feed troughs each formed by a pair of screw members with a movable table having a plurality of stacking troughs for alignment with the feed troughs and with a conveyor for delivering the stacks to the loading device, the fuel rods being moved along the stacking troughs upon a fluid cushion. 23 claims, 6 figures

Stepwise Assembly and Characterization of DNA Linked Two-Color Quantum Dot Clusters.

Science.gov (United States)

Coopersmith, Kaitlin; Han, Hyunjoo; Maye, Mathew M

2015-07-14

The DNA-mediated self-assembly of multicolor quantum dot (QD) clusters via a stepwise approach is described. The CdSe/ZnS QDs were synthesized and functionalized with an amphiphilic copolymer, followed by ssDNA conjugation. At each functionalization step, the QDs were purified via gradient ultracentrifugation, which was found to remove excess polymer and QD aggregates, allowing for improved conjugation yields and assembly reactivity. The QDs were then assembled and disassembled in a stepwise manner at a ssDNA functionalized magnetic colloid, which provided a convenient way to remove unreacted QDs and ssDNA impurities. After assembly/disassembly, the clusters' optical characteristics were studied by fluorescence spectroscopy and the assembly morphology and stoichiometry was imaged via electron microscopy. The results indicate that a significant amount of QD-to-QD energy transfer occurred in the clusters, which was studied as a function of increasing acceptor-to-donor ratios, resulting in increased QD acceptor emission intensities compared to controls.

Design and development of the CRBRP ex-vessel transfer machine

International Nuclear Information System (INIS)

Jones, C.E. Jr.

1977-01-01

The Reactor Refueling System (RRS) for the Clinch River Breeder Reactor Project (CRBRP) uses the Ex-Vessel Transfer Machine (EVTM) for transferring core assemblies outside the reactor vessel. The design of the Ex-Vessel Transfer Machine (EVTM) and its gantry-trolly for the CRBRP is discussed. The development tests required for the design are presented, in conjunction with the impact of the test results on the design. The impact of the increased seismic requirements on the design are also presented

Toolchain concept for the automated assembly of micro-optical systems

Science.gov (United States)

Haag, Sebastian; Müller, Tobias; Brecher, Christian

2014-05-01

In micro-optical assembly, the mastering of the steps of passive and active alignment, bonding, and part feeding as well as their interdependencies are crucial to the success of an automation solution. Process development is therefore complex and time consuming. Separation of assembly process planning and assembly execution decouples both phases so that production and process development can take place in parallel and even in spatially separated stations. The work presented in this paper refines the concept of flexible assembly systems by separating the phases of assembly process planning and assembly execution by providing a dedicated process development platform on the one hand and by providing automatisms regarding the transfer from the development platform into industrial production on the other. For this purpose, two key concepts are being developed by the research carried out at Fraunhofer IPT. The paper introduces the overall approach and formalisms as well as a form of notation based on part lists, product features and key characteristics and it shows industrial use cases the approach has been applied to. Key characteristics are constraints on spatial relations and they are expressed in terms of optical functions or geometric constraints which need to be fulfilled. In the paper, special attention is paid to the illustration of the end-user perspective.

One-Dimensional Multichromophor Arrays Based on DNA: From Self-Assembly to Light-Harvesting.

Science.gov (United States)

Ensslen, Philipp; Wagenknecht, Hans-Achim

2015-10-20

Light-harvesting complexes collect light energy and deliver it by a cascade of energy and electron transfer processes to the reaction center where charge separation leads to storage as chemical energy. The design of artificial light-harvesting assemblies faces enormous challenges because several antenna chromophores need to be kept in close proximity but self-quenching needs to be avoided. Double stranded DNA as a supramolecular scaffold plays a promising role due to its characteristic structural properties. Automated DNA synthesis allows incorporation of artificial chromophore-modified building blocks, and sequence design allows precise control of the distances and orientations between the chromophores. The helical twist between the chromophores, which is induced by the DNA framework, controls energy and electron transfer and thereby reduces the self-quenching that is typically observed in chromophore aggregates. This Account summarizes covalently multichromophore-modified DNA and describes how such multichromophore arrays were achieved by Watson-Crick-specific and DNA-templated self-assembly. The covalent DNA systems were prepared by incorporation of chromophores as DNA base substitutions (either as C-nucleosides or with acyclic linkers as substitutes for the 2'-deoxyribofuranoside) and as DNA base modifications. Studies with DNA base substitutions revealed that distances but more importantly relative orientations of the chromophores govern the energy transfer efficiencies and thereby the light-harvesting properties. With DNA base substitutions, duplex stabilization was faced and could be overcome, for instance, by zipper-like placement of the chromophores in both strands. For both principal structural approaches, DNA-based light-harvesting antenna could be realized. The major disadvantages, however, for covalent multichromophore DNA conjugates are the poor yields of synthesis and the solubility issues for oligonucleotides with more than 5-10 chromophore

Soft and probe lithography without ink transfer

NARCIS (Netherlands)

Huskens, Jurriaan; Li, X.; Péter, M.; Reinhoudt, David

2004-01-01

Microcontact printing (mCP) and dip-pen nanolithography (DPN) are versatile techniques for the creation of patterned surfaces. They commonly employ the transfer of an ink (e.g. a thiol) onto a surface (e.g. a gold-coated substrate) thus forming a self-assembled monolayer (SAM). Resolution of these

Printed assemblies of ultrathin, microscale inorganic light emitting diodes for deformable and semitransparent displays

Science.gov (United States)

Rogers, John A.; Nuzzo, Ralph; Kim, Hoon-sik; Brueckner, Eric; Park, Sang Il; Kim, Rak Hwan

2017-05-09

Described herein are printable structures and methods for making, assembling and arranging electronic devices. A number of the methods described herein are useful for assembling electronic devices where one or more device components are embedded in a polymer which is patterned during the embedding process with trenches for electrical interconnects between device components. Some methods described herein are useful for assembling electronic devices by printing methods, such as by dry transfer contact printing methods. Also described herein are GaN light emitting diodes and methods for making and arranging GaN light emitting diodes, for example for display or lighting systems.

Sequential induction of three recombination directionality factors directs assembly of tripartite integrative and conjugative elements.

Science.gov (United States)

Haskett, Timothy L; Terpolilli, Jason J; Ramachandran, Vinoy K; Verdonk, Callum J; Poole, Phillip S; O'Hara, Graham W; Ramsay, Joshua P

2018-03-01

Tripartite integrative and conjugative elements (ICE3) are a novel form of ICE that exist as three separate DNA regions integrated within the genomes of Mesorhizobium spp. Prior to conjugative transfer the three ICE3 regions of M. ciceri WSM1271 ICEMcSym1271 combine and excise to form a single circular element. This assembly requires three coordinated recombination events involving three site-specific recombinases IntS, IntG and IntM. Here, we demonstrate that three excisionases-or recombination directionality factors-RdfS, RdfG and RdfM are required for ICE3 excision. Transcriptome sequencing revealed that expression of ICE3 transfer and conjugation genes was induced by quorum sensing. Quorum sensing activated expression of rdfS, and in turn RdfS stimulated transcription of both rdfG and rdfM. Therefore, RdfS acts as a "master controller" of ICE3 assembly and excision. The dependence of all three excisive reactions on RdfS ensures that ICE3 excision occurs via a stepwise sequence of recombination events that avoids splitting the chromosome into a non-viable configuration. These discoveries expose a surprisingly simple control system guiding molecular assembly of these novel and complex mobile genetic elements and highlight the diverse and critical functions of excisionase proteins in control of horizontal gene transfer.

Seismic analysis with FEM for fuel transfer system of PWR nuclear power plant

International Nuclear Information System (INIS)

Jia Xiaofeng; Liu Pengliang; Bi Xiangjun; Ji Shunying

2012-01-01

In the PWR nuclear power plant, the function of the fuel transfer system (FTS) is to transfer the fuel assembly between the reactor building and the fuel building. The seismic analysis of the transfer system structure should be carried out to ensure the safety under OBE and SSE. Therefore, the ANASYS 12.0 software is adopted to construct the finite element analysis model for the fuel transfer system in a million kilowatt nuclear power plant. For the various configurations of FTS in the operating process, the stresses of the main structures, such as the transfer tube, fuel assembly container, fuel conveyor car, lifting frame in the reactor building, lifting frame in the fuel building, support and guide structure of conveyor car and the lifting frame in both buildings, are computed. The stresses are combined with the method of square root of square sum (SRSS) and assessed under various seismic conditions based on RCCM code, the results of the assessment satisfy the code. The results show that the stresses of the fuel transfer system structure meet the strength requirement, meanwhile, it can withstand the earthquake well. (authors)

Organic molecules deposited on graphene: A computational investigation of self-assembly and electronic structure

International Nuclear Information System (INIS)

Oliveira, I. S. S. de; Miwa, R. H.

2015-01-01

We use ab initio simulations to investigate the adsorption and the self-assembly processes of tetracyanoquinodimethane (TCNQ), tetrafluoro-tetracyanoquinodimethane (F4-TCNQ), and tetrasodium 1,3,6,8-pyrenetetrasulfonic acid (TPA) on the graphene surface. We find that there are no chemical bonds at the molecule–graphene interface, even at the presence of grain boundaries on the graphene surface. The molecules bond to graphene through van der Waals interactions. In addition to the molecule–graphene interaction, we performed a detailed study of the role played by the (lateral) molecule–molecule interaction in the formation of the, experimentally verified, self-assembled layers of TCNQ and TPA on graphene. Regarding the electronic properties, we calculate the electronic charge transfer from the graphene sheet to the TCNQ and F4-TCNQ molecules, leading to a p-doping of graphene. Meanwhile, such charge transfer is reduced by an order of magnitude for TPA molecules on graphene. In this case, it is not expected a significant doping process upon the formation of self-assembled layer of TPA molecules on the graphene sheet

Methodologies for Verification and Validation of Space Launch System (SLS) Structural Dynamic Models

Science.gov (United States)

Coppolino, Robert N.

2018-01-01

Responses to challenges associated with verification and validation (V&V) of Space Launch System (SLS) structural dynamics models are presented in this paper. Four methodologies addressing specific requirements for V&V are discussed. (1) Residual Mode Augmentation (RMA), which has gained acceptance by various principals in the NASA community, defines efficient and accurate FEM modal sensitivity models that are useful in test-analysis correlation and reconciliation and parametric uncertainty studies. (2) Modified Guyan Reduction (MGR) and Harmonic Reduction (HR, introduced in 1976), developed to remedy difficulties encountered with the widely used Classical Guyan Reduction (CGR) method, are presented. MGR and HR are particularly relevant for estimation of "body dominant" target modes of shell-type SLS assemblies that have numerous "body", "breathing" and local component constituents. Realities associated with configuration features and "imperfections" cause "body" and "breathing" mode characteristics to mix resulting in a lack of clarity in the understanding and correlation of FEM- and test-derived modal data. (3) Mode Consolidation (MC) is a newly introduced procedure designed to effectively "de-feature" FEM and experimental modes of detailed structural shell assemblies for unambiguous estimation of "body" dominant target modes. Finally, (4) Experimental Mode Verification (EMV) is a procedure that addresses ambiguities associated with experimental modal analysis of complex structural systems. Specifically, EMV directly separates well-defined modal data from spurious and poorly excited modal data employing newly introduced graphical and coherence metrics.

Experimental studies on heat transfer to supercritical water in 2 × 2 rod bundle with two channels

International Nuclear Information System (INIS)

Gu, H.Y.; Hu, Z.X.; Liu, D.; Xiao, Y.; Cheng, X.

2015-01-01

Highlights: • Heat transfer to supercritical water in a 2 × 2 rod bundle is investigated. • Effects of system parameters on heat transfer in bundle are analyzed. • The test data were compared with twenty heat transfer correlations. - Abstract: The experiment of heat transfer to supercritical water in 2 × 2 rod bundle is performed at Shanghai Jiao Tong University. The test section consists of two channels separated by a square steel assembly box with rounded corners. Water flows downward in the first channel and then turns upward in the second channel to cool the 2 × 2 rod bundle installed inside the assembly box. The bundle consists of four heated rods of 10 mm in O.D. and 1.18 in pitch-to-diameter ratio. The fluid enthalpy in the first channel increases due to the heat transfer through the assembly box when flowing downward. The minimum fluid enthalpy increase in the first channel appears at the pseudo-critical region due to the small temperature difference between the two channels. Effects of various parameters on heat transfer behavior inside the 2 × 2 rod bundle are similar to those observed in tube or annuli. No special phenomenon in heat transfer is observed during the mass flux and power transient. The steady-state heat transfer correlation is applicable to predict the heat transfer in the mass or power transient sequence. In addition, the importance of several dimensionless numbers and the accuracy of 20 heat transfer correlations are assessed. It is concluded that the buoyancy parameter proposed by Cheng et al. (2009) shows unique effect on heat transfer coefficient. Among the 20 selected heat transfer correlations, the correlations of Jackson and Fewster (1975) and Bishop et al. (1964) give the best predictions when compared with the experimental data

Modeling of block copolymer dry etching for directed self-assembly lithography

Science.gov (United States)

Belete, Zelalem; Baer, Eberhard; Erdmann, Andreas

2018-03-01

Directed self-assembly (DSA) of block copolymers (BCP) is a promising alternative technology to overcome the limits of patterning for the semiconductor industry. DSA exploits the self-assembling property of BCPs for nano-scale manufacturing and to repair defects in patterns created during photolithography. After self-assembly of BCPs, to transfer the created pattern to the underlying substrate, selective etching of PMMA (poly (methyl methacrylate)) to PS (polystyrene) is required. However, the etch process to transfer the self-assemble "fingerprint" DSA patterns to the underlying layer is still a challenge. Using combined experimental and modelling studies increases understanding of plasma interaction with BCP materials during the etch process and supports the development of selective process that form well-defined patterns. In this paper, a simple model based on a generic surface model has been developed and an investigation to understand the etch behavior of PS-b-PMMA for Ar, and Ar/O2 plasma chemistries has been conducted. The implemented model is calibrated for etch rates and etch profiles with literature data to extract parameters and conduct simulations. In order to understand the effect of the plasma on the block copolymers, first the etch model was calibrated for polystyrene (PS) and poly (methyl methacrylate) (PMMA) homopolymers. After calibration of the model with the homopolymers etch rate, a full Monte-Carlo simulation was conducted and simulation results are compared with the critical-dimension (CD) and selectivity of etch profile measurement. In addition, etch simulations for lamellae pattern have been demonstrated, using the implemented model.

Charge-Transfer Supra-Amphiphiles Built by Water-Soluble Tetrathiafulvalenes and Viologen-Containing Amphiphiles: Supramolecular Nanoassemblies with Modifiable Dimensions.

Science.gov (United States)

Lv, Zhong-Peng; Chen, Bin; Wang, Hai-Ying; Wu, Yue; Zuo, Jing-Lin

2015-08-05

In this study, multidimensional nanoassemblies with various morphologies such as nanosheets, nanorods, and nanofibers are developed via charge-transfer interaction and supra-amphiphile self-assembling in aqueous phase. The charge-transfer interactions between tetrathiafulvalene derivatives (TTFs) and methyl viologen derivatives (MVs) have been confirmed by the characteristic charger-transfer absorption. (1) H NMR and electrospray ionizsation mass spectrometry (ESI-MS) analyses also indicate supra-amphiphiles are formed by the combination of TTFs and MVs head group through charge-transfer interaction and Coulombic force. X-ray single crystal structural studies, transmission electron microscopy (TEM), and scanning electron microscopy (SEM) reveal that both linkage pattern of TTFs in hydrophilic part and alkane chain structure in hydrophobic part have significant influence on nanoassemblies morphology and microstructure. Moreover, gold nanoparticles (AuNPs) are introduced in the above supramolecular nanoassemblies to construct a supra-amphiphile-driven organic-AuNPs assembly system. AuNPs could be assembled into 1D-3D structures by adding different amount of MVs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Toward tunable doping in graphene FETs by molecular self-assembled monolayers

Science.gov (United States)

Li, Bing; Klekachev, Alexander V.; Cantoro, Mirco; Huyghebaert, Cedric; Stesmans, André; Asselberghs, Inge; de Gendt, Stefan; de Feyter, Steven

2013-09-01

dopant. Electronic supplementary information (ESI) available: AFM images of self-assembled monolayers of OA on HOPG; AFM height image of the graphene surface on a SiC substrate; high resolution STM image of a self-assembled monolayer of OA on HOPG; transfer curves of a graphene FET with and without baking steps; transfer curves of a graphene FET under high vacuum conditions; transfer curves of a graphene FET and its Raman response before and after OA treatment; transfer curves of a graphene FET before and after rinsing with n-hexane. See DOI: 10.1039/c3nr01255g

Pump/heat exchanger assembly for pool-type reactor

International Nuclear Information System (INIS)

Nathenson, R.D.; Slepian, R.M.

1989-01-01

This patent describes a heat exchanger and pump assembly for transferring thermal energy from a heated, first electrically conductive fluid to a pumped, second electrically conductive fluid and for transferring internal energy from the pumped, second electrically conductive fluid to the first electrically conductive fluid, the assembly adapted to be disposed within a pool of the first electrically conductive fluid and comprising: a heat exchanger comprising means for defining a first annularly shaped cavity for receiving a flow of the second electrically conductive fluid and a plurality of tubes disposed within the cavity, whereby the second electrically conductive fluid in the cavity is heated, each of the tubes having an input and an output end. The input ends being disposed at the top of the heat exchanger for receiving from the pool a flow of the first electrically conductive fluid therein. The output ends being disposed at the bottom of and free of the cavity defining means for discharging the first electrically conductive fluid directly into the pool; a pump disposed beneath the heat exchanger and comprised of a plurality of flow couplers disposed in a circular array, each flow coupler comprised of a pump duct for receiving the first electrically conductive fluid and a generator duct for receiving the second electrically conductive fluid

Distance matters. Assessing socioeconomic impacts of the Dukovany nuclear power plant in the Czech Republic: Local perceptions and statistical evidence

Czech Academy of Sciences Publication Activity Database

Frantál, Bohumil; Malý, Jiří; Ouředníček, M.; Nemeškal, J.

2016-01-01

Roč. 24, č. 1 (2016), s. 2-13 ISSN 1210-8812 R&D Projects: GA MŠk(CZ) EE2.3.20.0025 Institutional support: RVO:68145535 Keywords : nuclear power plant impacts * spatial analysis * risk perceptions Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 2.149, year: 2016 http://www.degruyter.com/view/j/mgr.2016.24.issue-1/mgr-2016-0001/mgr-2016-0001.xml?format=INT

Photoinduced electron transfer through peptide-based self-assembled monolayers chemisorbed on gold electrodes: directing the flow-in and flow-out of electrons through peptide helices.

Science.gov (United States)

Venanzi, Mariano; Gatto, Emanuela; Caruso, Mario; Porchetta, Alessandro; Formaggio, Fernando; Toniolo, Claudio

2014-08-21

Photoinduced electron transfer (PET) experiments have been carried out on peptide self-assembled monolayers (SAM) chemisorbed on a gold substrate. The oligopeptide building block was exclusively formed by C(α)-tetrasubstituted α-aminoisobutyric residues to attain a helical conformation despite the shortness of the peptide chain. Furthermore, it was functionalized at the C-terminus by a pyrene choromophore to enhance the UV photon capture cross-section of the compound and by a lipoic group at the N-terminus for linking to gold substrates. Electron transfer across the peptide SAM has been studied by photocurrent generation experiments in an electrochemical cell employing a gold substrate modified by chemisorption of a peptide SAM as a working electrode and by steady-state and time-resolved fluorescence experiments in solution and on a gold-coated glass. The results show that the electronic flow through the peptide bridge is strongly asymmetric; i.e., PET from the C-terminus to gold is highly favored with respect to PET in the opposite direction. This effect arises from the polarity of the Au-S linkage (Au(δ+)-S(δ-), junction effect) and from the electrostatic field generated by the peptide helix.

Sequential induction of three recombination directionality factors directs assembly of tripartite integrative and conjugative elements.

Directory of Open Access Journals (Sweden)

Timothy L Haskett

2018-03-01

Full Text Available Tripartite integrative and conjugative elements (ICE3 are a novel form of ICE that exist as three separate DNA regions integrated within the genomes of Mesorhizobium spp. Prior to conjugative transfer the three ICE3 regions of M. ciceri WSM1271 ICEMcSym1271 combine and excise to form a single circular element. This assembly requires three coordinated recombination events involving three site-specific recombinases IntS, IntG and IntM. Here, we demonstrate that three excisionases-or recombination directionality factors-RdfS, RdfG and RdfM are required for ICE3 excision. Transcriptome sequencing revealed that expression of ICE3 transfer and conjugation genes was induced by quorum sensing. Quorum sensing activated expression of rdfS, and in turn RdfS stimulated transcription of both rdfG and rdfM. Therefore, RdfS acts as a "master controller" of ICE3 assembly and excision. The dependence of all three excisive reactions on RdfS ensures that ICE3 excision occurs via a stepwise sequence of recombination events that avoids splitting the chromosome into a non-viable configuration. These discoveries expose a surprisingly simple control system guiding molecular assembly of these novel and complex mobile genetic elements and highlight the diverse and critical functions of excisionase proteins in control of horizontal gene transfer.

End-to-end self-assembly of gold nanorods in isopropanol solution: experimental and theoretical studies

Energy Technology Data Exchange (ETDEWEB)

Gordel, M., E-mail: marta.gordel@pwr.edu.pl [Wrocław University of Technology, Advanced Materials Engineering and Modelling Group, Faculty of Chemistry (Poland); Piela, K., E-mail: katarzyna.piela@pwr.edu.pl [Wrocław University of Technology, Department of Physical and Quantum Chemistry (Poland); Kołkowski, R. [Wrocław University of Technology, Advanced Materials Engineering and Modelling Group, Faculty of Chemistry (Poland); Koźlecki, T. [Wrocław University of Technology, Department of Chemical Engineering, Faculty of Chemistry (Poland); Buckle, M. [CNRS, École Normale Supérieure de Cachan, Laboratoire de Biologie et Pharmacologie Appliquée (France); Samoć, M. [Wrocław University of Technology, Advanced Materials Engineering and Modelling Group, Faculty of Chemistry (Poland)

2015-12-15

We describe here a modification of properties of colloidal gold nanorods (NRs) resulting from the chemical treatment used to carry out their transfer into isopropanol (IPA) solution. The NRs acquire a tendency to attach one to another by their ends (end-to-end assembly). We focus on the investigation of the change in position and shape of the longitudinal surface plasmon (l-SPR) band after self-assembly. The experimental results are supported by a theoretical calculation, which rationalizes the dramatic change in optical properties when the NRs are positioned end-to-end at short distances. The detailed spectroscopic characterization performed at the consecutive stages of transfer of the NRs from water into IPA solution revealed the features of the interaction between the polymers used as ligands and their contribution to the final stage, when the NRs were dispersed in IPA solution. The efficient method of aligning the NRs detailed here may facilitate applications of the self-assembled NRs as building blocks for optical materials and biological sensing.Graphical Abstract.

On the mixing model for calculating the temperature fields in nuclear reactor fuel assemblies

International Nuclear Information System (INIS)

Mikhin, V.I.; Zhukov, A.V.

1985-01-01

One of the alternatives of the mixing model applied for calculating temperature fields in nuclear reactor fuel assemblies,including the fuel assemblies with nonequilibrium energy-release in fuel element cross section, is consistently described. The equations for both constant and variable values of coolant density and heat capacity are obtained. The mixing model is based on a set of mass, heat and longitudinal momentum balance equations. This set is closed by the ratios connecting the unknown values for gaps between fuel elements with the averaged values for neighbouring channels. The ratios to close momentum and heat balance equations, explaining, in particular, the nonequivalent heat and mass, momentum and mass transfer coefficients, are suggested. The balance equations with variable coolant density and heat capacity are reduced to the form coinciding with those of the similar equations with constant values of these parameters. Application of one of the main ratios of the mixing model relating the coolant transverse overflow in the gaps between fuel elements to the averaged coolant rates (flow rates) in the neighbouring channels is mainly limited by the coolant stabilized flow in the fuel assemblies with regular symmetrical arrangement of elements. Mass transfer coefficients for these elements are experimentally determined. The ratio in the paper is also applicable for calculation of fuel assembly temperature fields with a small relative shift of elements

Bio-inspired nanobowl/nanoball structures fabricated via solvent etching/swelling on nanosphere assembly patterns

Energy Technology Data Exchange (ETDEWEB)

Chang, Wan-Yi; Liu, Pang-Hsin; Wu, You [Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan, ROC (China); Chung, Yi-Chang, E-mail: ycchung@nuk.edu.tw [Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan, ROC (China); Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan, ROC (China)

2014-11-03

Ordered self-assembled nanopatterns have attracted much attention for their ability to mimic moth-eye structures and display unique optical properties. In the study, emulsifier-free emulsion polymerization was performed to prepare polystyrene nanospheres with uniform size distribution. Various hydrophilic monomers were added to copolymerize with styrene, including 2-hydroxyethyl methacrylate, acrylic acid, and methyl acrylic acid, respectively, to enhance the self-assembling ability of nanospheres. The nanosphere suspension was injected into an air–water interface to self-assemble a nanosphere array, and then the resulting photonic crystal film was deposited on a substrate using a scooping transfer technique. The layer-by-layer scooping transfer technique can be applied to produce 2D and 3D assembled nanosphere layers on an area as large as a 4-inch wafer. The pattern of the 2D nanosphere array was attached to a UV-curable precursor surface and then encapsulated and transferred to the crosslinked resin after UV irradiation. The sample was then immersed into some solvents which could partially swell the resin surface to produce nanoball structures or etch the surface to generate nanobowl structures. The size of the as-prepared polystyrene spheres was about 360 nm, while the feature size of the nanoballs was about 230 nm after undergoing acetonitrile swelling. The facile and inexpensive technique can be applied to produce ordered nanoball patterns for various applications, such as optical coatings, superhydrophobic coatings, biophotosensors, antireflection films, dry adhesives, and so on. - Highlights: • We prepared core-shell PS nanosphere suspensions with narrow-size-distribution. • We employed a scooping technique to fabricate large-area nanosphere monolayers. • Swelling by acetonitrile formed nanoballs on a UV resin/nanosphere laminated layer. • Etching by toluene produced nanobowl on the UV resin/nanosphere laminated layer. • The parted nanoball

Self-assembly of block copolymer micelles: synthesis via reversible addition-fragmentation chain transfer polymerization and aqueous solution properties.

Science.gov (United States)

Mya, Khine Y; Lin, Esther M J; Gudipati, Chakravarthy S; Gose, Halima B A S; He, Chaobin

2010-07-22

Poly(hexafluorobutyl methacrylate) (PHFBMA) homopolymer was synthesized by reversible addition-fragmentation chain transfer (RAFT)-mediated living radical polymerization in the presence of cyano-2-propyl dithiobenzoate (CPDB) RAFT agent. A block copolymer of PHFBMA-poly(propylene glycol acrylate) (PHFBMA-b-PPGA) with dangling poly(propylene glycol) (PPG) side chains was then synthesized by using CPDB-terminated PHFBMA as a macro-RAFT agent. The amphiphilic properties and self-assembly of PHFBMA-b-PPGA block copolymer in aqueous solution were investigated by dynamic and static light scattering (DLS and SLS) studies, in combination with fluorescence spectroscopy and transmission electron microscopy (TEM). Although PPG shows moderately hydrophilic character, the formation of nanosize polymeric micelles was confirmed by fluorescence and TEM studies. The low value of the critical aggregation concentration exhibited that the tendency for the formation of copolymer aggregates in aqueous solution was very high due to the strong hydrophobicity of the PHFBMA(145)-b-PPGA(33) block copolymer. The combination of DLS and SLS measurements revealed the existence of micellar aggregates in aqueous solution with an association number of approximately 40 +/- 7 for block copolymer micelles. It was also found in TEM observation that there are 40-50 micelles accumulated into one aggregate and these micelles are loosely packed inside the aggregate.

Comparison of HYDRA predictions to temperature data from two single-assembly spent fuel heat transfer tests

International Nuclear Information System (INIS)

McCann, R.A.

1986-12-01

The HYDRA computer code was used to simulate the thermal performance of an actual and a model spent fuel assembly. The HYDRA-predicted temperatures were then compared with measured data from two single-assembly test sections. The objective of this effort was to further verify the predictive capabilities of the HYDRA code for use in assessments of the hydrothermal performance of spent fuel dry storage systems. After HYDRA has been adequately evaluated and validated, the code will be documented to permit design and licensing safety analyses

Reversible photocontrol of molecular assemblies of metal complex containing azo-amphiphiles

International Nuclear Information System (INIS)

Einaga, Yasuaki; Mikami, Rie; Akitsu, Takashiro; Li, Guangming

2005-01-01

Photo-controllable molecular systems, [M(en) 2 ][Pt(en) 2 Cl 2 ](1) 4 (M 2+ =Pt 2+ , Pd 2+ and en=ethylenediamine), have been designed by the self-assembly of chloride-bridged platinum/palladium complexes and photochromic amphiphiles of the azobenzene derivative, 4-[4-(N-methyl-N-n-dodecylamino)phenylazo]benzene sulfonic acid (designated as compound 1). Reversible structural changes caused by cis-trans photoisomerization of azo groups in compound 1 were observed by alternating illumination of UV and visible light. Visible illumination resulted in the formation of the plate-like structures, whereas UV illumination resulted in fragmentation of the assembling structures. Reversible changes were observed in the electronic states of the chloride-bridged platinum/palladium complexes; the plate-like structures exhibited charge transfer absorption of chloride-bridged platinum complexes and delocalized Pt(II)/Pt(IV) states, while the fragments of the separated complexes exhibited no charge transfer bands. As a consequence, we have discovered that the reversible structural changes in this system could be controlled by photoillumination

The soluble loop BC region guides, but not dictates, the assembly of the transmembrane cytochrome b6.

Directory of Open Access Journals (Sweden)

Lydia Tome-Stangl

Full Text Available Studying folding and assembly of naturally occurring α-helical transmembrane proteins can inspire the design of membrane proteins with defined functions. Thus far, most studies have focused on the role of membrane-integrated protein regions. However, to fully understand folding pathways and stabilization of α-helical membrane proteins, it is vital to also include the role of soluble loops. We have analyzed the impact of interhelical loops on folding, assembly and stability of the heme-containing four-helix bundle transmembrane protein cytochrome b6 that is involved in charge transfer across biomembranes. Cytochrome b6 consists of two transmembrane helical hairpins that sandwich two heme molecules. Our analyses strongly suggest that the loop connecting the helical hairpins is not crucial for positioning the two protein "halves" for proper folding and assembly of the holo-protein. Furthermore, proteolytic removal of any of the remaining two loops, which connect the two transmembrane helices of a hairpin structure, appears to also not crucially effect folding and assembly. Overall, the transmembrane four-helix bundle appears to be mainly stabilized via interhelical interactions in the transmembrane regions, while the soluble loop regions guide assembly and stabilize the holo-protein. The results of this study might steer future strategies aiming at designing heme-binding four-helix bundle structures, involved in transmembrane charge transfer reactions.

Printable semiconductor structures and related methods of making and assembling

Science.gov (United States)

Nuzzo, Ralph G.; Rogers, John A.; Menard, Etienne; Lee, Keon Jae; Khang; , Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao; Ko, Heung Cho; Mack, Shawn

2013-03-12

The present invention provides a high yield pathway for the fabrication, transfer and assembly of high quality printable semiconductor elements having selected physical dimensions, shapes, compositions and spatial orientations. The compositions and methods of the present invention provide high precision registered transfer and integration of arrays of microsized and/or nanosized semiconductor structures onto substrates, including large area substrates and/or flexible substrates. In addition, the present invention provides methods of making printable semiconductor elements from low cost bulk materials, such as bulk silicon wafers, and smart-materials processing strategies that enable a versatile and commercially attractive printing-based fabrication platform for making a broad range of functional semiconductor devices.

The Assembly of the LHC Short Straight Sections at CERN Work Organization, Quality Assurance and Lessons Learned

CERN Document Server

Bourcey, N; López, R; Poncet, A; Parma, V

2007-01-01

After 4 years of activity, the assembly of approximately 500 Short Straight Sections (SSS) for the LHC has come to an end at the beginning of 2007. This activity, which was initially foreseen in European industry, was in-sourced at CERN because of the insolvency of the prime contractor. While the quadrupole cold masses were produced in industry, the assembly within their cryostats was transferred to CERN and executed by an external company under a result-oriented contract. CERN procured cryostat components, set up a dedicated 2000 m2 assembly hall with all the specific assembly equipment and tooling and defined the assembly and testing procedures. The contractor took up responsibility for the delivery, on time, of assemblies according to the required quality. A dedicated CERN production and quality assurance team was constituted. A specific quality assurance plan was set up involving 2 additional contractors responsible for weld inspections on a total of about 20'000 assembly welds and the execution of about ...

On the Hopping Efficiency of Nanoparticles in the Electron Transfer across Self‐Assembled Monolayers

DEFF Research Database (Denmark)

Liu, Feng; Khan, Kamran; Liang, Jing‐Hong

2013-01-01

Redox reactions of solvated molecular species at gold‐electrode surfaces modified by electrochemically inactive self‐assembled molecular monolayers (SAMs) are found to be activated by introducing Au nanoparticles (NPs) covalently bound to the SAM to form a reactive Au–alkanedithiol–NP–molecule hy...

Rapid, Brushless Self-assembly of a PS-b-PDMS Block Copolymer for Nanolithography

DEFF Research Database (Denmark)

Rasappa, Sozaraj; Schulte, Lars; Borah, Dipu

2014-01-01

and antidot patterns after short solvo-thermal annealing. Unlike previous reports on this system, low temperature and short annealing time provide self-assembly in homogeneous thin films covering large substrate areas. This on-chip mask was then used for pattern transfer to the underlying silicon substrate...

A computationally efficient method for full-core conjugate heat transfer modeling of sodium fast reactors

Energy Technology Data Exchange (ETDEWEB)

Hu, Rui, E-mail: rhu@anl.gov; Yu, Yiqi

2016-11-15

Highlights: • Developed a computationally efficient method for full-core conjugate heat transfer modeling of sodium fast reactors. • Applied fully-coupled JFNK solution scheme to avoid the operator-splitting errors. • The accuracy and efficiency of the method is confirmed with a 7-assembly test problem. • The effects of different spatial discretization schemes are investigated and compared to the RANS-based CFD simulations. - Abstract: For efficient and accurate temperature predictions of sodium fast reactor structures, a 3-D full-core conjugate heat transfer modeling capability is developed for an advanced system analysis tool, SAM. The hexagon lattice core is modeled with 1-D parallel channels representing the subassembly flow, and 2-D duct walls and inter-assembly gaps. The six sides of the hexagon duct wall and near-wall coolant region are modeled separately to account for different temperatures and heat transfer between coolant flow and each side of the duct wall. The Jacobian Free Newton Krylov (JFNK) solution method is applied to solve the fluid and solid field simultaneously in a fully coupled fashion. The 3-D full-core conjugate heat transfer modeling capability in SAM has been demonstrated by a verification test problem with 7 fuel assemblies in a hexagon lattice layout. Additionally, the SAM simulation results are compared with RANS-based CFD simulations. Very good agreements have been achieved between the results of the two approaches.

Fast Neutron Emission Tomography of Used Nuclear Fuel Assemblies

Science.gov (United States)

Hausladen, Paul; Iyengar, Anagha; Fabris, Lorenzo; Yang, Jinan; Hu, Jianwei; Blackston, Matthew

2017-09-01

Oak Ridge National Laboratory is developing a new capability to perform passive fast neutron emission tomography of spent nuclear fuel assemblies for the purpose of verifying their integrity for international safeguards applications. Most of the world's plutonium is contained in spent nuclear fuel, so it is desirable to detect the diversion of irradiated fuel rods from an assembly prior to its transfer to ``difficult to access'' storage, such as a dry cask or permanent repository, where re-verification is practically impossible. Nuclear fuel assemblies typically consist of an array of fuel rods that, depending on exposure in the reactor and consequent ingrowth of 244Cm, are spontaneous sources of as many as 109 neutrons s-1. Neutron emission tomography uses collimation to isolate neutron activity along ``lines of response'' through the assembly and, by combining many collimated views through the object, mathematically extracts the neutron emission from each fuel rod. This technique, by combining the use of fast neutrons -which can penetrate the entire fuel assembly -and computed tomography, is capable of detecting vacancies or substitutions of individual fuel rods. This paper will report on the physics design and component testing of the imaging system. This material is based upon work supported by the U.S. Department of Energy, Office of Defense Nuclear Nonproliferation Research and Development within the National Nuclear Security Administration, under Contract Number DE-AC05-00OR22725.

Evaluation of Hose in Hose Transfer Line Service Life for Hanford's Interim Stabilization Program

International Nuclear Information System (INIS)

TORRES, T.D.

2000-01-01

RPP-6153, Engineering Task Plan for Hose-in-Hose Transfer System for the Interim Stabilization Program, defines the programmatic goals, functional requirements, and technical criteria for the development and subsequent installation of transfer line equipment to support Hanford's Interim Stabilization Program. RPP-6028, Specification for Hose in Hose Transfer Lines for Hanford's Interim Stabilization Program, has been issued to define the specific requirements for the design, manufacture, and verification of transfer line assemblies for specific waste transfer applications. Included in RPP-6028 are tables defining the chemical constituents of concern to which transfer lines will be exposed. Current Interim Stabilization Program planning forecasts that the at-grade transfer lines will be required to convey pumpable waste for as much as three years after commissioning. Prudent engineering dictates that the equipment placed in service have a working life in excess of this forecasted time period, with some margin to allow for future adjustments to the planned schedule. This document evaluates the effective service life of the Hose-in-Hose Transfer Lines, based on information submitted by the manufacturer and published literature. The effective service life of transfer line assemblies is a function of several factors. Foremost among these are process fluid characteristics, ambient environmental conditions, and the manufacturer's stated shelf life. This evaluation examines the manufacturer's certification of shelf life, the manufacturer's certifications of chemical compatibility with waste, and published literature on the effects of exposure to ionizing radiation on the mechanical properties of elastomeric materials to evaluate transfer line service life

Partial vs. integer electron transfer in molecular assemblies: On the importance of multideterminant theoretical description and the necessity to find a solution within DFT

Energy Technology Data Exchange (ETDEWEB)

Geskin, Victor; Cornil, Jérôme [Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, B-7000 Mons (Belgium); Stadler, Robert [Department of Physical Chemistry, University of Vienna, Sensengasse 8/7, A-1090 Vienna (Austria)

2015-01-22

Nonequilibrium Green's function techniques (NEGF) combined with density functional theory (DFT) calculations have become a standard tool for the description of electron transport through single molecule nanojunctions in the coherent tunneling (CT) regime. However, the applicability of these methods for transport in the Coulomb blockade (CB) regime is questionable. For a molecular assembly model, with multideterminant calculations as a benchmark, we show how a closed-shell ansatz, the usual ingredient of mean-field methods, fails to properly describe the step like electron-transfer characteristic in weakly coupled systems. Detailed analysis of this misbehavior allows us to propose a practical scheme to extract the addition energies in the CB regime for single-molecule junctions from NEGF DFT within the local-density approximation (closed shell). We show also that electrostatic screening effects are taken into account within this simple approach.

Analysis of irradiation temperature in fuel rods of OGL-1 fuel assembly

International Nuclear Information System (INIS)

Fukuda, Kousaku; Kobayashi, Fumiaki; Minato, Kazuo; Ikawa, Katsuichi; Iwamoto, Kazumi

1984-10-01

Irradiation temperature in the fuel rods of 5th OGL-1 fuel assembly was analysed by the system composed by STPDSP2 and TRUMP codes. As the measured input-data, following parameters were allowed for; circumferential heating distribution around the fuel rod, which was measured in the JMTR critical assembly, axial heating distribution through the fuel rod, ratio of peak heatings of three fuel rods, and pre- and post-irradiation outer radii of the fuel compacts and inner radii of the graphite sleeves, which had been measured in PIE of the 5th OGL-1 fuel assembly. In computation the axial distributions of helium coolant temperature through the fuel rod and the heating value of each fuel rod were, firstly, calculated as input data for TRUMP. The TRUMP calculation yielded the temperatures which were fitted in those measured by all of the thermo-couples installed in the fuel rods, by adjusting only the value of the surface heat transfer coefficient, and consequently, the temperatures in all portions of the fuel rod were obtained. The apparent heat transfer coefficient changed to 60% of the initial values in the middle period of irradiation. For this reduction it was deduced that shoot had covered the surface of the fuel rod during irradiation, which was confirmed in PIE. Beside it, several things were found in this analysis. (author)

Robotically Assembled Aerospace Structures: Digital Material Assembly using a Gantry-Type Assembler

Science.gov (United States)

Trinh, Greenfield; Copplestone, Grace; O'Connor, Molly; Hu, Steven; Nowak, Sebastian; Cheung, Kenneth; Jenett, Benjamin; Cellucci, Daniel

2017-01-01

This paper evaluates the development of automated assembly techniques for discrete lattice structures using a multi-axis gantry type CNC machine. These lattices are made of discrete components called "digital materials." We present the development of a specialized end effector that works in conjunction with the CNC machine to assemble these lattices. With this configuration we are able to place voxels at a rate of 1.5 per minute. The scalability of digital material structures due to the incremental modular assembly is one of its key traits and an important metric of interest. We investigate the build times of a 5x5 beam structure on the scale of 1 meter (325 parts), 10 meters (3,250 parts), and 30 meters (9,750 parts). Utilizing the current configuration with a single end effector, performing serial assembly with a globally fixed feed station at the edge of the build volume, the build time increases according to a scaling law of n4, where n is the build scale. Build times can be reduced significantly by integrating feed systems into the gantry itself, resulting in a scaling law of n3. A completely serial assembly process will encounter time limitations as build scale increases. Automated assembly for digital materials can assemble high performance structures from discrete parts, and techniques such as built in feed systems, parallelization, and optimization of the fastening process will yield much higher throughput.

Self-Assembled Fluorescent Nanoprobe Based on Forster Resonance Energy Transfer for Carbon Monoxide in Living Cells and Animals via Ligand Exchange.

Science.gov (United States)

Jia, Ruizhen; Song, Pengfei; Wang, Jingjing; Mai, Hengtang; Li, Sixian; Cheng, Yu; Wu, Song

2018-05-29

Carbon monoxide (CO) is recognized as a biologically essential gaseous neurotransmitter that modulates many physiological processes in living subjects. Currently reported fluorescent probes for CO imaging in cells basically utilize palladium related chemistry which requires complicated synthetic work. Herein we provide a new strategy to construct a fluorescent nanoprobe, NanoCO-1, based on the Forster resonance energy transfer (FRET) mechanism by entrapping the existing dirhodium complex as the energy acceptor and the CO recognition part, and a commonly used nitrobenzoxadiazole (NBD) dye as energy donor into a micelle formed by self-assembly. The exchange of ligands in the dirhodium complex by CO in the nanoprobe disrupts the FRET and leads to the turn-on of fluorescence. The merits of NanoCO-1 including good biocompatibility, selectivity, photostability, and low cytotoxity, render this nanoprobe ability to track CO in living cells, zebrafish embryo, and larvae. Our straightforward approach can be extended to establish the CO fluorescent probes based on adsorption of CO on a variety of metal derivatives.

Facile preparation of luminescent and intelligent gold nanodots based on supramolecular self-assembly

International Nuclear Information System (INIS)

Shi Yunfeng; Li Sujuan; Zhou Yahui; Zhai Qingpan; Hu Mengyue; Cai Fensha; Du Jimin; Liang Jiamiao; Zhu Xinyuan

2012-01-01

A new strategy for preparing luminescent and intelligent gold nanodots based on supramolecular self-assembly is described in this paper. The supramolecular self-assembly was initiated through electrostatic interactions and ion pairing between palmitic acid and hyperbranched poly(ethylenimine). The resulting structures not only have the dynamic reversible properties of supramolecules but also possess torispherical and highly branched architectures. Thus they can be regarded as a new kind of ideal nanoreactor for preparing intelligent Au nanodots. By preparing Au nanodots within this kind of supramolecular self-assembly, the environmental sensitivity of intelligent polymers and the optical, electrical properties of Au nanodots can be combined, endowing the Au nanodots with intelligence. In this paper, a supramolecular self-assembly process based on dendritic poly(ethylenimine) and palmitic acid was designed and then applied to prepare fluorescent and size-controlled Au nanodots. The pH response of Au nanodots embodied by phase transfer from oil phase to water phase was also investigated. (paper)

Sequence assembly

DEFF Research Database (Denmark)

Scheibye-Alsing, Karsten; Hoffmann, S.; Frankel, Annett Maria

2009-01-01

Despite the rapidly increasing number of sequenced and re-sequenced genomes, many issues regarding the computational assembly of large-scale sequencing data have remain unresolved. Computational assembly is crucial in large genome projects as well for the evolving high-throughput technologies and...... in genomic DNA, highly expressed genes and alternative transcripts in EST sequences. We summarize existing comparisons of different assemblers and provide a detailed descriptions and directions for download of assembly programs at: http://genome.ku.dk/resources/assembly/methods.html....

Silica nanoparticles for the layer-by-layer assembly of fully electro-active cytochrome c multilayers

Directory of Open Access Journals (Sweden)

Feifel Sven C

2011-12-01

Full Text Available Abstract Background For bioanalytical systems sensitivity and biomolecule activity are critical issues. The immobilization of proteins into multilayer systems by the layer-by-layer deposition has become one of the favorite methods with this respect. Moreover, the combination of nanoparticles with biomolecules on electrodes is a matter of particular interest since several examples with high activities and direct electron transfer have been found. Our study describes the investigation on silica nanoparticles and the redox protein cytochrome c for the construction of electro-active multilayer architectures, and the electron transfer within such systems. The novelty of this work is the construction of such artificial architectures with a non-conducting building block. Furthermore a detailed study of the size influence of silica nanoparticles is performed with regard to formation and electrochemical behavior of these systems. Results We report on interprotein electron transfer (IET reaction cascades of cytochrome c (cyt c immobilized by the use of modified silica nanoparticles (SiNPs to act as an artificial matrix. The layer-by-layer deposition technique has been used for the formation of silica particles/cytochrome c multilayer assemblies on electrodes. The silica particles are characterized by dynamic light scattering (DLS, Fourier transformed infrared spectroscopy (FT-IR, Zeta-potential and transmission electron microscopy (TEM. The modified particles have been studied with respect to act as an artificial network for cytochrome c and to allow efficient interprotein electron transfer reactions. We demonstrate that it is possible to form electro-active assemblies with these non-conducting particles. The electrochemical response is increasing linearly with the number of layers deposited, reaching a cyt c surface concentration of about 80 pmol/cm2 with a 5 layer architecture. The interprotein electron transfer through the layer system and the

Assembly and maintenance of full scale NIF amplifiers in the amplifier module prototype laboratory (AMPLAB)

International Nuclear Information System (INIS)

Horvath, J. A.

1998-01-01

Mechanical assembly and maintenance of the prototype National Ignition Facility amplifiers in the Amplifier Module Prototype Laboratory (AMPLAB) at Lawrence Livermore National Laboratory requires specialized equipment designed to manipulate large and delicate amplifier components in a safe and clean manner. Observations made during the operation of this assembly and maintenance equipment in AMPLAB provide design guidance for similar tools being built for the National Ignition Facility. Fixtures used for amplifier frame installation, laser slab and flashlamp cassette assembly, transport, and installation, and in-situ blastshield exchange are presented. Examples include a vacuum slab gripper, slab handling clean crane, slab cassette assembly fixture, sealed transport vehicle for slab cassette movement between the cleanroom and amplifier, slab cassette transfer fixture between the cleanroom and transport vehicle, and equipment needed for frame assembly unit, blastshield, an d flashlamp cassette installation and removal. The use of these tools for amplifier assembly, system reconfiguration, reflector replacement, and recovery from an abnormal occurrence such as a flashlamp explosion is described. Observations are made on the design and operation of these tools and their contribution to the final design

Hypocholesterolemic Response to Karaya Saponin and Rhodobacter capsulatus in Broiler Chickens

OpenAIRE

Afrose, Sadia; Hossain, Md. Sharoare; Maki, Takaaki; Tsujii, Hirotada

2010-01-01

Dietary karaya saponin and Rhodobacter capsulatus (R. capsulatus) are known to have hypocholesterolemic actions, as reported in our previous studies. This study examined possible synergistic hypocholesterolemic effects of karaya saponin and R. capsulatus in broilers. A total of 150 broilers were allocated into 10 treatments: control, saponin 25 mg, saponin 50 mg, saponin 75 mg, saponin 25 mg+R. capsulatus 0.2 g, saponin 25 mg+R. capsulatus 0.4 g, saponin 50 mg+R. capsulatus 0.2 g, saponin 50 ...

Transfer hook for nuclear fuel assemblies and nuclear reactor having a such hook

International Nuclear Information System (INIS)

Thevenot, L.P.

1990-01-01

For removing irradiated nuclear fuel assemblies above the level of the liquid metal in the vessel without loss of cooling, the hook mechanism has a guide tube with two annular cavities and a pump to circulate the reactor cooling fluid which flows out by gravity. A such hook used in a LMFBR reduces the height of the reactor vessel and consequently the initial capital cost [fr

Bacteriophage Assembly

Directory of Open Access Journals (Sweden)

Anastasia A. Aksyuk

2011-02-01

Full Text Available 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.

Siemens technology transfer and cooperation in the nuclear fuel area

International Nuclear Information System (INIS)

Holley, H.-P.; Fuchs, J. H.; Rothenbuecher, R. A.

1997-01-01

Siemens is a full-range supplier in the area of nuclear power generation with broad experience and activities in the field of nuclear fuel. Siemens has developed advanced fuel technology for all types fuel assemblies used throughout the world and has significant experience worldwide in technology transfer in the field of nuclear fuel. Technology transfer and cooperation has ranged between the provision of mechanical design advice for a specific fuel design and the erection of complete fabrication plants for commercial operation in 3 countries. In the following the wide range of Siemens' technology transfer activities for both fuel design and fuel fabrication technologies are shown

Monitoring ligand-dependent assembly of receptor ternary complexes in live cells by BRETFect.

Science.gov (United States)

Cotnoir-White, David; El Ezzy, Mohamed; Boulay, Pierre-Luc; Rozendaal, Marieke; Bouvier, Michel; Gagnon, Etienne; Mader, Sylvie

2018-03-13

There is currently an unmet need for versatile techniques to monitor the assembly and dynamics of ternary complexes in live cells. Here we describe bioluminescence resonance energy transfer with fluorescence enhancement by combined transfer (BRETFect), a high-throughput technique that enables robust spectrometric detection of ternary protein complexes based on increased energy transfer from a luciferase to a fluorescent acceptor in the presence of a fluorescent intermediate. Its unique donor-intermediate-acceptor relay system is designed so that the acceptor can receive energy either directly from the donor or indirectly via the intermediate in a combined transfer, taking advantage of the entire luciferase emission spectrum. BRETFect was used to study the ligand-dependent cofactor interaction properties of the estrogen receptors ERα and ERβ, which form homo- or heterodimers whose distinctive regulatory properties are difficult to dissect using traditional methods. BRETFect uncovered the relative capacities of hetero- vs. homodimers to recruit receptor-specific cofactors and regulatory proteins, and to interact with common cofactors in the presence of receptor-specific ligands. BRETFect was also used to follow the assembly of ternary complexes between the V2R vasopressin receptor and two different intracellular effectors, illustrating its use for dissection of ternary protein-protein interactions engaged by G protein-coupled receptors. Our results indicate that BRETFect represents a powerful and versatile technique to monitor the dynamics of ternary interactions within multimeric complexes in live cells.

The Au-S bond in biomolecular adsorption and electrochemical electron transfer

DEFF Research Database (Denmark)

Ford, M. J.; Hush, N. S.; Marcuccio, S.

Interfacial electrochemical electron transfer (ET) of redox metalloproteins is long established. For the proteins to retain full ET or enzyme activity, modification of the electrode surfaces, such as goldsurfaces by self-assembled molecular monolayers (SAMs), is nearly always required, where pure...

RAFT Synthesis and Self-Assembly of Free-Base Porphyrin Cored Star Polymers

Directory of Open Access Journals (Sweden)

Lin Wu

2011-01-01

Full Text Available Reversible addition fragmentation chain transfer (RAFT synthesis and self-assembly of free-base porphyrin cored star polymers are reported. The polymerization, in the presence of a free-base porphyrin cored chain transfer agent (CTA-FBP, produced porphyrin star polymers with controlled molecular weights and narrow polydispersities for a number of monomers including N, N-dimethylacrylamide (DMA and styrene (St. Well-defined amphiphilic star block copolymers, P-(PS-PDMA4 and P-(PDMA-PS4 (P: porphyrin, were also prepared and used for self-assembly studies. In methanol, a selective solvent for PDMA, spherical micelles were observed for both block copolymers as characterized by TEM. UV-vis studies suggested star-like micelles were formed from P-(PS-PDMA4, while P-(PDMA-PS4 aggregated into flower-like micelles. Spectrophotometric titrations indicated that the optical response of these two micelles to external ions was a function of micellar structures. These structure-related properties will be used for micelle studies and functional material development in the future.

Assembly of the alpha-toxin-hexamer of Staphylococcus aureus in the liposome membrane.

Science.gov (United States)

Ikigai, H; Nakae, T

1987-02-15

It has been shown that the access of the alpha-toxin of Staphylococcus aureus to the target membrane and assembly of the hexamer can be monitored independently by respectively measuring the fluorescence energy transfer from the tryptophan residue(s) of the toxin to the dansylated phosphatidylethanolamine in the liposome membrane and the fluorescence increment of the toxin at 336 nm (Ikigai, H., and Nakae, T., (1987) J. Biol. Chem. 262, 2150-2155). Measurement of these parameters under various conditions showed the following results: when phosphatidylcholine (PC) liposomes composed of saturated fatty acids were mixed with the toxin, the fluorescence energy transfer occurred below, at, and above the transition temperature of the lipid, but the change of fluorescence at 336 nm was never detectable; when PC-liposomes containing unsaturated fatty acids were used, both the fluorescence energy transfer and the fluorescence increment of 336 nm were observed. These results suggested that the toxin-membrane interaction occurs in PC-membranes containing saturated and/or unsaturated fatty acids and that the oligomerization occurs only in the presence of PC containing unsaturated fatty acid(s). This conclusion was supported by the results of quantitative determination of the toxin-hexamer assembly and leakage of carboxyfluorescein from PC-liposomes under conditions similar to the above.

Optimizing Transcriptome Assemblies for Eleusine indica Leaf and Seedling by Combining Multiple Assemblies from Three De Novo Assemblers

Directory of Open Access Journals (Sweden)

Shu Chen

2015-03-01

Full Text Available Due to rapid advances in sequencing technology, increasing amounts of genomic and transcriptomic data are available for plant species, presenting enormous challenges for biocomputing analysis. A crucial first step for a successful transcriptomics-based study is the building of a high-quality assembly. Here, we utilized three different de novo assemblers (Trinity, Velvet, and CLC and the EvidentialGene pipeline tr2aacds to assemble two optimized transcript sets for the notorious weed species, . Two RNA sequencing (RNA-seq datasets from leaf and aboveground seedlings were processed using three assemblers, which resulted in 20 assemblies for each dataset. The contig numbers and N50 values of each assembly were compared to study the effect of read number, k-mer size, and in silico normalization on assembly output. The 20 assemblies were then processed through the tr2aacds pipeline to remove redundant transcripts and to select the transcript set with the best coding potential. Each assembly contributed a considerable proportion to the final transcript combination with the exception of the CLC-k14. Thus each assembler and parameter set did assemble better contigs for certain transcripts. The redundancy, total contig number, N50, fully assembled contig number, and transcripts related to target-site herbicide resistance were evaluated for the EvidentialGene and Trinity assemblies. Comparing the EvidentialGene set with the Trinity assembly revealed improved quality and reduced redundancy in both leaf and seedling EvidentialGene sets. The optimized transcriptome references will be useful for studying herbicide resistance in and the evolutionary process in the three allotetraploid offspring.

Electrochemistry and biosensing activity of cytochrome c immobilized on a mesoporous interface assembled from carbon nanospheres

International Nuclear Information System (INIS)

Wang, Y.; Bian, X.; Liao, L.; Zhu, J.; Guo, K.; Kong, J.; Liu, B.

2012-01-01

We report on an amperometric biosensor for hydrogen peroxide. It is obtained via layer-by-layer assembly of ordered mesoporous carbon nanospheres and poly(diallyldimethylammonium) on the surface of an indium tin oxide (ITO) glass electrode and subsequent adsorption of cytochrome c. UV-vis absorption spectroscopy was applied to characterize the process of forming the assembled layers. Cyclic voltammetry revealed a direct and quasi-reversible electron transfer between cytochrome c and the surface of the modified ITO electrode. The surface-controlled electron transfer has an apparent heterogeneous electron-transfer rate constant (k s ) of 5.9 ± 0.2 s -1 in case of the 5-layer electrode. The biosensor displays good electrocatalytic response to the reduction of H 2O 2, and the amperometric signal increase steadily with the concentration of H 2 O 2 in the range from 5 μM to 1.5 mM. The detection limit is 1 μM at pH 7.4. The apparent Michaelis-Menten constant (K m ) of the sensor is 0.53 mM. We assume that the observation of a direct electron transfer of cytochrome c on mesoporous carbon nanospheres may form the basis for a feasible approach for durable and reliable detection of H 2 O 2 . (author)

Development and capital investment tasks involved in the production of charge transfer equipment

International Nuclear Information System (INIS)

Simon, Sandor

1983-01-01

Stringent requirements had to be considered in the course of the production development of charge transfer equipment. The production of structures demanding extremely high endurance was based on extensive co-operation. Special alloys were needed for parts and bearings, special heat-treatment was required at certain sections for large dimensions etc. Appropriate mashine stock, assembly and test hall have been built for assembling and testing the equipment with both 440 and 100 MW.(Sz.J.)

National Assembly of Serbia and European Parliament: A constitutional-law comparison

Directory of Open Access Journals (Sweden)

Orlović Slobodan P.

2011-01-01

Full Text Available For better understanding of the two parallel processes - EU integration and the rapprochement of the Republic of Serbia to the Union, a comparison of National Assembly of Serbia and European Parliament could be used. There are two legislative bodies in matter, which despite some similarities have numerous differences. The key difference is that National Assembly is a 'full' legislative body, and European Parliament is a part of the Union's legislation, such as one of the Parliament's houses. Perhaps the most important cause of this difference is the fact that National Assembly is a power body of the State, and the European Parliament is an institution of a political and economic community which is not (yet a state. It is to be assumed that the constitutional-law differences between European Parliament and National Assembly, or the parliament of another state, will increasingly diminish if the processes of the transfer of states' sovereignty to the European Union continue. At the same time, the relation of the political power of the European Parliament and the national parliaments of the Union state members will change.

Layer-by-Layer Assembly of Glucose Oxidase on Carbon Nanotube Modified Electrodes.

Science.gov (United States)

Suroviec, Alice H

2017-01-01

The use of enzymatically modified electrodes for the detection of glucose or other non-electrochemically active analytes is becoming increasingly common. Direct heterogeneous electron transfer to glucose oxidase has been shown to be kinetically difficult, which is why electron transfer mediators or indirect detection is usually used for monitoring glucose with electrochemical sensors. It has been found, however, that electrodes modified with single or multi-walled carbon nanotubes (CNTs) demonstrate fast heterogeneous electron transfer kinetics as compared to that found for traditional electrodes. Incorporating CNTs into the assembly of electrochemical glucose sensors, therefore, affords the possibility of facile electron transfer to glucose oxidase, and a more direct determination of glucose. This chapter describes the methods used to use CNTs in a layer-by-layer structure along with glucose oxidase to produce an enzymatically modified electrode with high turnover rates, increased stability and shelf-life.

Fuel assemblies

International Nuclear Information System (INIS)

Nakatsuka, Masafumi.

1979-01-01

Purpose: To prevent scattering of gaseous fission products released from fuel assemblies stored in an fbr type reactor. Constitution; A cap provided with means capable of storing gas is adapted to amount to the assembly handling head, for example, by way of threading in a storage rack of spent fuel assemblies consisting of a bottom plate, a top plate and an assembly support mechanism. By previously eliminating the gas inside of the assembly and the cap in the storage rack, gaseous fission products upon loading, if released from fuel rods during storage, are stored in the cap and do not scatter in the storage rack. (Horiuchi, T.)

Proton Mediated Chemistry and Catalysis in a Self-Assembled Supramolecular Host

Energy Technology Data Exchange (ETDEWEB)

Pluth, Michael; Bergman, Robert; Raymond, Kenneth

2009-04-10

of protonated guests was translated into chemical catalysis by taking advantage of the potential for accelerating reactions that take place via positively charged transition states, which could be potentially stabilized by encapsulation. Orthoformates, generally stable in neutral or basic solution, were found to be suitable substrates for catalytic hydrolysis by the assembly. Orthoformates small enough to undergo encapsulation were readily hydrolyzed by the assembly in basic solution, with rate acceleration factors up to 3900 compared with those of the corresponding uncatalyzed reactions. Furthering the analogy to enzymes that obey Michaelis-Menten kinetics, we observed competitive inhibition with the inhibitor NPr{sub 4}{sup +}, thereby confirming that the interior cavity of the assembly was the active site for catalysis. Mechanistic studies revealed that the assembly is required for catalysis and that the rate-limiting step of the reaction involves proton transfer from hydronium to the encapsulated substrate. Encapsulation in the assembly changes the orthoformate hydrolysis from an A-1 mechanism (in which decomposition of the protonated substrate is the rate-limiting step) to an A-S{sub E}2 mechanism (in which proton transfer is the rate-limiting step). The study of hydrolysis in the assembly was next extended to acetals, which were also catalytically hydrolyzed by the assembly in basic solution. Acetal hydrolysis changed from the A-1 mechanism in solution to an A-2 mechanism inside the assembly, where attack of water on the protonated substrate is rate limiting. This work provides rare examples of assembly-catalyzed reactions that proceed with substantial rate accelerations despite the absence of functional groups in the cavity and with mechanisms fully elucidated by quantitative kinetic studies.

Proton-Mediated Chemistry and Catalysis in a Self-Assembled Supramolecular Host

International Nuclear Information System (INIS)

Pluth, Michael; Bergman, Robert; Raymond, Kenneth

2009-01-01

protonated guests was translated into chemical catalysis by taking advantage of the potential for accelerating reactions that take place via positively charged transition states, which could be potentially stabilized by encapsulation. Orthoformates, generally stable in neutral or basic solution, were found to be suitable substrates for catalytic hydrolysis by the assembly. Orthoformates small enough to undergo encapsulation were readily hydrolyzed by the assembly in basic solution, with rate acceleration factors up to 3900 compared with those of the corresponding uncatalyzed reactions. Furthering the analogy to enzymes that obey Michaelis-Menten kinetics, we observed competitive inhibition with the inhibitor NPr 4 + , thereby confirming that the interior cavity of the assembly was the active site for catalysis. Mechanistic studies revealed that the assembly is required for catalysis and that the rate-limiting step of the reaction involves proton transfer from hydronium to the encapsulated substrate. Encapsulation in the assembly changes the orthoformate hydrolysis from an A-1 mechanism (in which decomposition of the protonated substrate is the rate-limiting step) to an A-S E 2 mechanism (in which proton transfer is the rate-limiting step). The study of hydrolysis in the assembly was next extended to acetals, which were also catalytically hydrolyzed by the assembly in basic solution. Acetal hydrolysis changed from the A-1 mechanism in solution to an A-2 mechanism inside the assembly, where attack of water on the protonated substrate is rate limiting. This work provides rare examples of assembly-catalyzed reactions that proceed with substantial rate accelerations despite the absence of functional groups in the cavity and with mechanisms fully elucidated by quantitative kinetic studies.

Carbon dot-Au(i)Ag(0) assembly for the construction of an artificial light harvesting system.

Science.gov (United States)

Jana, Jayasmita; Aditya, Teresa; Pal, Tarasankar

2018-03-06

Artificial light harvesting systems (LHS) with inorganic counterparts are considered to be robust as well as mechanistically simple, where the system follows the donor-acceptor principle with an unchanged structural pattern. Plasmonic gold or silver nanoparticles are mostly chosen as inorganic counterparts to design artificial LHS. To capitalize on its electron accepting capability, Au(i) has been considered in this work for the synergistic stabilization of a system with intriguingly fluorescing silver(0) clusters produced in situ. Thus a stable fluorescent Au(i)Ag(0) assembly is generated with electron accepting capabilities. On the other hand, carbon dots have evolved as new fluorescent probes due to their unique physicochemical properties. Utilizing the simple electronic behavior of carbon dots, an electronic interaction between the fluorescent Au(i)Ag(0) and a carbon dot has been investigated for the construction of a new artificial light harvesting system. This coinage metal assembly allows surface energy transfer where it acts as an acceptor, while the carbon dot behaves as a good donor. The energy transfer efficiency has been calculated experimentally to be significant (81.3%) and the Au(i)Ag(0)-carbon dot assembly paves the way for efficient artificial LHS.

Customization and design of directed self-assembly using hybrid prepatterns

Science.gov (United States)

Cheng, Joy; Doerk, Gregory S.; Rettner, Charles T.; Singh, Gurpreet; Tjio, Melia; Truong, Hoa; Arellano, Noel; Balakrishnan, Srinivasan; Brink, Markus; Tsai, Hsinyu; Liu, Chi-Chun; Guillorn, Michael; Sanders, Daniel P.

2015-03-01

Diminishing error tolerance renders the customization of patterns created through directed self-assembly (DSA) extremely challenging at tighter pitch. A self-aligned customization scheme can be achieved using a hybrid prepattern comprising both organic and inorganic regions that serves as a guiding prepattern to direct the self-assembly of the block copolymers as well as a cut mask pattern for the DSA arrays aligned to it. In this paper, chemoepitaxy-based self-aligned customization is demonstrated using two types of organic-inorganic prepatterns. CHEETAH prepattern for "CHemoepitaxy Etch Trim using a self-Aligned Hardmask" of preferential hydrogen silsesquioxane (HSQ, inorganic resist), non-preferential organic underlayer is fabricated using electron beam lithography. Customized trench or hole arrays can be achieved through co-transfer of DSA-formed arrays and CHEETAH prepattern. Herein, we also introduce a tone-reversed version called reverse-CHEETAH (or rCHEETAH) in which customized line segments can be achieved through co-transfer of DSA-formed arrays formed on a prepattern wherein the inorganic HSQ regions are nonpreferential and the organic regions are PMMA preferential. Examples of two-dimensional self-aligned customization including 25nm pitch fin structures and an 8-bar "IBM" illustrate the versatility of this customization scheme using rCHEETAH.

Self-Assembly of Gold Nanoparticles at the Liquid/Liquid Interface

International Nuclear Information System (INIS)

Lee, Kang Yeol; Han, Sang Woo

2005-01-01

We have shown that the crown ether derivative can mediate the transfer of gold nanoparticles in water solution to water/oil interface, results in directing the self-assembly of nanoparticles in the form of a novel nanocomposite film. The interfacial film of nanoparticles could be transferred to various solid substrates. The experimental results indicate the formation of nanoparticles monolayers at water/oil interfaces. Our work is an important step towards interfacial entrapment and self-assembly of nanoparticles for efficient creation of 2D nanostructures. These types of materials may be used in developing catalysts, sensors, and nanoelectronic devices. Currently, we are attempting to synthesize other composite films by using specific interactions between suitable organic or inorganic ligands and various nanoparticles. The intense research activity in the field of nanoparticles is motivated by the search for new materials in order to further miniaturize electronic devices, as well as by the fundamental question of how molecular electronic properties evolve with increasing size in this intermediate region between molecular and solid-state physics. In this respect, molecularly bridged nanoparticle aggregates have been attracting growing interest. The properties of two-dimensional assemblies of metal nanoparticles are controlled by the composition, geometry, and spatial arrangement of the nanoparticle building blocks. Such structures have been used for a variety of important applications in catalysis, photonics, electronics, and biological sensing. The 2D/3D control over the spatial arrangement of nanoparticles is primarily based on the thiolamphilic nature of metal nanoparticles, hydrogenbonding interactions, the highly specific recognition interaction of antigens/antibodies, and specific base-pairing interactions between DNA and its complementary strand

Problems of heat transfer within the containing vessel of high performance LMFBR spent fuel shipping casks

International Nuclear Information System (INIS)

Pope, R.B.; Gartling, D.K.; Schimmel, W.P. Jr.; Larson, D.W.

1976-01-01

A preliminary assessment of heat transfer problems internal to a LMFBR spent fuel shipping cask is reported. The assessment is based upon previous results obtained in full-scale, electrically heated mockups of an LMFBR assembly located in a containing pipe, and also upon analytical and empirical studies presented in this paper. It is shown that a liquid coolant will be required to adequately distribute the decay heat of short-cooled assemblies from the fuel region to the containing cask structure. Liquid sodium apparently provides the best heat transfer, and sufficient data are available to adequately model the heat transfer processes involved. Dowtherm A is the most efficient organic evaluated to date and presented in the open literature. Since the organic materials have high Prandtl and usually high Rayleigh numbers, natural convection is the predominant mode of heat transfer. It is shown that a more comprehensive understanding of the convective processes will be required before heat transfer with an organic coolant can be adequately modeled. However, in view of systems considerations, Dowtherm A should be further considered as an alternative to sodium for use as a LMFBR spent fuel shipping cask coolant

Effects of interface roughness on cohesive strength of self-assembled monolayers

Energy Technology Data Exchange (ETDEWEB)

Zhang, Chen [Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, IL 61801 (United States); Awasthi, Amnaya P. [Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, 32611 (United States); Geubelle, Philippe H., E-mail: geubelle@illinois.edu [Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, IL 61801 (United States); Grady, Martha E.; Sottos, Nancy R. [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, IL 61801 (United States)

2017-03-01

Highlights: • Self-assembled monolayer/transfer-printed gold interface modeled using continuum-level simulation. • Initial deformed film profile analyzed and instability assessed. • Effective cohesive response of SAM-enhanced interface extracted from spallation model. • Reduction of up to 70% cohesive strength of the interface from incorporation of roughness demonstrated. - Abstract: Self-assembled monolayers (SAMs) are aggregates of small molecular chains that have the property to form highly ordered assemblies. The choice of terminal groups on the chains makes them excellent contenders of molecular-level tailoring. Molecular dynamics (MD) simulations and experimental observations of spallation of two SAM-enhanced gold-film/silicon-substrate interfaces have shown that the cohesive strength of SAM-enriched transfer-printed interfaces is strongly dependent on the choice of terminal groups. Though the MD results of perfectly ordered atomistic surfaces show the same qualitative trend as the experiments, they over-predict the interfacial cohesive strengths by a factor of about 50. Results from AFM studies have revealed that the roughness of these interfaces is of the same order (∼1 nm) as the range of atomistic interactions. Hence, surface roughness is a key contributor in significantly reducing interfacial cohesive strength in these systems. In this manuscript, a continuum-level study is performed to investigate the influence of surface roughness on the cohesive strength of the interface between a Si/SAM substrate and a transfer-printed gold film. We approximate the film as a deformable continuum interacting with a rough substrate of SAMs represented by a harmonic function. Using a cohesive law derived from MD, spallation is simulated to evaluate the effective traction-separation characteristics for the rough SAM–gold interface. Our analysis shows that incorporating roughness may reduce the interfacial cohesive strength by an order of magnitude depending

CFD method research on characteristics cells in rod bundle fuel assembly

International Nuclear Information System (INIS)

Chen Jie; Chen Bingyan; Zhang Hong

2011-01-01

Two characteristic cells are in AFA-3G fuel assembly, that is typical cell and control rod guide cell. And there are some rules on the arrangement of mixing vanes. For the two characteristic cells, mixing capability is evaluated axially from the point of the first and second kind of sub-channel with CFD method. Mass mixing and heat mixing are interaction but different with each other. Although the mass mixing in the first kind of sub-channel is stronger, the thermal capability of the two is to some tune from the point of heat transfer. In the experiment research on thermal-hydraulic performance of AFA-3G fuel assembly, the arrangements of mixing vanes should refer to the two spacer grids of characteristic cells. (authors)

Evaluation of Hose in Hose Transfer Line Service Life for Hanford's Interim Stabilization Program

Energy Technology Data Exchange (ETDEWEB)

TORRES, T.D.

2000-08-24

RPP-6153, Engineering Task Plan for Hose-in-Hose Transfer System for the Interim Stabilization Program, defines the programmatic goals, functional requirements, and technical criteria for the development and subsequent installation of transfer line equipment to support Hanford's Interim Stabilization Program. RPP-6028, Specification for Hose in Hose Transfer Lines for Hanford's Interim Stabilization Program, has been issued to define the specific requirements for the design, manufacture, and verification of transfer line assemblies for specific waste transfer applications. Included in RPP-6028 are tables defining the chemical constituents of concern to which transfer lines will be exposed. Current Interim Stabilization Program planning forecasts that the at-grade transfer lines will be required to convey pumpable waste for as much as three years after commissioning. Prudent engineering dictates that the equipment placed in service have a working life in excess of this forecasted time period, with some margin to allow for future adjustments to the planned schedule. This document evaluates the effective service life of the Hose-in-Hose Transfer Lines, based on information submitted by the manufacturer and published literature. The effective service life of transfer line assemblies is a function of several factors. Foremost among these are process fluid characteristics, ambient environmental conditions, and the manufacturer's stated shelf life. This evaluation examines the manufacturer's certification of shelf life, the manufacturer's certifications of chemical compatibility with waste, and published literature on the effects of exposure to ionizing radiation on the mechanical properties of elastomeric materials to evaluate transfer line service life.

Conjugate heat transfer simulations of advanced research reactor fuel

Energy Technology Data Exchange (ETDEWEB)

Piro, M.H.A., E-mail: pirom@aecl.ca; Leitch, B.W.

2014-07-01

Highlights: • Temperature predictions are enhanced by coupling heat transfer in solid and fluid zones. • Seven different cases are considered to observe trends in predicted temperature and pressure. • The seven cases consider high/medium/low power, flow, burnup, fuel material and geometry. • Simulations provide temperature predictions for performance/safety. Boiling is unlikely. • Simulations demonstrate that a candidate geometry can enhance performance/safety. - Abstract: The current work presents numerical simulations of coupled fluid flow and heat transfer of advanced U–Mo/Al and U–Mo/Mg research reactor fuels in support of performance and safety analyses. The objective of this study is to enhance predictions of the flow regime and fuel temperatures through high fidelity simulations that better capture various heat transfer pathways and with a more realistic geometric representation of the fuel assembly in comparison to previous efforts. Specifically, thermal conduction, convection and radiation mechanisms are conjugated between the solid and fluid regions. Also, a complete fuel element assembly is represented in three dimensional space, permitting fluid flow and heat transfer to be simulated across the entire domain. Seven case studies are examined that vary the coolant inlet conditions, specific power, and burnup to investigate the predicted changes in the pressure drop in the coolant and the fuel, clad and coolant temperatures. In addition, an alternate fuel geometry is considered with helical fins (replacing straight fins in the existing design) to investigate the relative changes in predicted fluid and solid temperatures. Numerical simulations predict that the clad temperature is sensitive to changes in the thermal boundary layer in the coolant, particularly in simultaneously developing flow regions, while the temperature in the fuel is anticipated to be unaffected. Finally, heat transfer between fluid and solid regions is enhanced with

Thermal Hydraulic Computational Fluid Dynamics Simulations and Experimental Investigation of Deformed Fuel Assemblies

Energy Technology Data Exchange (ETDEWEB)

Mays, Brian [AREVA Federal Services, Lynchburg, VA (United States); Jackson, R. Brian [TerraPower, Bellevue, WA (United States)

2017-03-08

The project, Toward a Longer Life Core: Thermal Hydraulic CFD Simulations and Experimental Investigation of Deformed Fuel Assemblies, DOE Project code DE-NE0008321, was a verification and validation project for flow and heat transfer through wire wrapped simulated liquid metal fuel assemblies that included both experiments and computational fluid dynamics simulations of those experiments. This project was a two year collaboration between AREVA, TerraPower, Argonne National Laboratory and Texas A&M University. Experiments were performed by AREVA and Texas A&M University. Numerical simulations of these experiments were performed by TerraPower and Argonne National Lab. Project management was performed by AREVA Federal Services. The first of a kind project resulted in the production of both local point temperature measurements and local flow mixing experiment data paired with numerical simulation benchmarking of the experiments. The project experiments included the largest wire-wrapped pin assembly Mass Index of Refraction (MIR) experiment in the world, the first known wire-wrapped assembly experiment with deformed duct geometries and the largest numerical simulations ever produced for wire-wrapped bundles.

A Novel Poly(vinylidene fluoride)-Based 4-Miktoarm Star Terpolymer: Synthesis and Self-Assembly

KAUST Repository

Patil, Yogesh Raghunath; Bilalis, Panagiotis; Polymeropoulos, George; Almahdali, Sarah; Hadjichristidis, Nikolaos; Rodionov, Valentin

2018-01-01

A well-defined amphiphilic miktoarm polymer incorporating poly(vinylidene fluoride) (PVDF), polystyrene (PS), and poly(ethylene glycol) (PEG) blocks was synthesized via a combination of atom-transfer radical polymerization (ATRP), iodine transfer radical polymerization (ITP), and copper-catalyzed azide-alkyne cycloaddition (CuAAC). Morphology and self-assembly of this star polymer were examined in organic solvents and in water. The aggregates formed in water were found to possess unusual frustrated topology due to immiscibility of PS and PVDF. The polymer was evaluated for transport of small hydrophobic molecules in water.

A Novel Poly(vinylidene fluoride)-Based 4-Miktoarm Star Terpolymer: Synthesis and Self-Assembly

KAUST Repository

Patil, Yogesh Raghunath

2018-03-15

A well-defined amphiphilic miktoarm polymer incorporating poly(vinylidene fluoride) (PVDF), polystyrene (PS), and poly(ethylene glycol) (PEG) blocks was synthesized via a combination of atom-transfer radical polymerization (ATRP), iodine transfer radical polymerization (ITP), and copper-catalyzed azide-alkyne cycloaddition (CuAAC). Morphology and self-assembly of this star polymer were examined in organic solvents and in water. The aggregates formed in water were found to possess unusual frustrated topology due to immiscibility of PS and PVDF. The polymer was evaluated for transport of small hydrophobic molecules in water.

Sensor mount assemblies and sensor assemblies

Science.gov (United States)

Miller, David H [Redondo Beach, CA

2012-04-10

Sensor mount assemblies and sensor assemblies are provided. In an embodiment, by way of example only, a sensor mount assembly includes a busbar, a main body, a backing surface, and a first finger. The busbar has a first end and a second end. The main body is overmolded onto the busbar. The backing surface extends radially outwardly relative to the main body. The first finger extends axially from the backing surface, and the first finger has a first end, a second end, and a tooth. The first end of the first finger is disposed on the backing surface, and the tooth is formed on the second end of the first finger.

Globally homochiral assembly of two-dimensional molecular networks triggered by co-absorbers.

Science.gov (United States)

Chen, Ting; Yang, Wen-Hong; Wang, Dong; Wan, Li-Jun

2013-01-01

Understanding the chirality induction and amplification processes, and the construction of globally homochiral surfaces, represent essential challenges in surface chirality studies. Here we report the induction of global homochirality in two-dimensional enantiomorphous networks of achiral molecules via co-assembly with chiral co-absorbers. The scanning tunnelling microscopy investigations and molecular mechanics simulations demonstrate that the point chirality of the co-absorbers transfers to organizational chirality of the assembly units via enantioselective supramolecular interactions, and is then hierarchically amplified to the global homochirality of two-dimensional networks. The global homochirality of the network assembly shows nonlinear dependence on the enantiomeric excess of chiral co-absorber in the solution phase, demonstrating, for the first time, the validation of the 'majority rules' for the homochirality control of achiral molecules at the liquid/solid interface. Such an induction and nonlinear chirality amplification effect promises a new approach towards two-dimensional homochirality control and may reveal important insights into asymmetric heterogeneous catalysis, chiral separation and chiral crystallization.

In-capillary self-assembly and proteolytic cleavage of polyhistidine peptide capped quantum dots

Energy Technology Data Exchange (ETDEWEB)

Wang, Jianhao; Li, Jingyan; Li, Jinchen; Liu, Feifei [School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou, Jiangsu, 213164 (China); Zhou, Xiang; Yao, Yi [Changzhou Qianhong Bio-pharma Co. Ltd, Changzhou 213164, Jiangsu (China); Wang, Cheli [School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou, Jiangsu, 213164 (China); Qiu, Lin, E-mail: linqiupjj@gmail.com [School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou, Jiangsu, 213164 (China); Jiang, Pengju, E-mail: pengju.jiang@gmail.com [School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou, Jiangsu, 213164 (China); State Key Laboratory of Pharmaceutical Biotechnology, Nanjing, Jiangsu (China)

2015-10-01

A new method using fluorescence coupled capillary electrophoresis (CE-FL) for monitoring self-assembly and proteolytic cleavage of hexahistidine peptide capped quantum dots (QDs) inside a capillary has been developed in this report. QDs and the ATTO 590-labeled hexahistidine peptide (H6-ATTO) were injected into a capillary, sequentially. Their self-assembly inside the capillary was driven by a metal-affinity force which yielded a new fluorescence signal due to Förster resonance energy transfer (FRET). The highly efficient separation of fluorescent complexes and the FRET process were analyzed using CE-FL. The self-assembly of QDs and biomolecules was found to effectively take place inside the capillary. The kinetics of the assembly was monitored by CE-FL, and the approach was extended to the study of proteolytic cleavage of surface conjugated peptides. Being the first in-depth analysis of in-capillary nanoparticle–biomolecule assembly, the novel approach reported here provides inspiration to the development of QD-based FRET probes for biomedical applications. - Highlights: • We examined the self-assembly QDs with H6-ATTO inside a capillary. • We prove CE-FL to be a powerful method to resolve QDs-H6-ATTO complex. • We achieve chromatographic separation of QDs-H6-ATTO complex. • We discovered a novel strategy for the online detection of thrombin. • This technique integrated “injection, mixing, reaction, separation and detection”.

Multiple Surrogate Modeling for Wire-Wrapped Fuel Assembly Optimization

International Nuclear Information System (INIS)

Raza, Wasim; Kim, Kwang-Yong

2007-01-01

In this work, shape optimization of seven pin wire wrapped fuel assembly has been carried out in conjunction with RANS analysis in order to evaluate the performances of surrogate models. Previously, Ahmad and Kim performed the flow and heat transfer analysis based on the three-dimensional RANS analysis. But numerical optimization has not been applied to the design of wire-wrapped fuel assembly, yet. Surrogate models are being widely used in multidisciplinary optimization. Queipo et al. reviewed various surrogates based models used in aerospace applications. Goel et al. developed weighted average surrogate model based on response surface approximation (RSA), radial basis neural network (RBNN) and Krigging (KRG) models. In addition to the three basic models, RSA, RBNN and KRG, the multiple surrogate model, PBA also has been employed. Two geometric design variables and a multi-objective function with a weighting factor have been considered for this problem

NAC international dry spent fuel transfer technology

International Nuclear Information System (INIS)

Shelton, Thomas A.; Malone, James P.; Patterson, John R.

1996-01-01

Full text: For more than ten years NAC International (NAC) has designed, fabricated, tested and operated a variety of Dry Transfer Systems (DTS's) to transfer spent nuclear fuel from facilities with limited crane capabilities, limited accesses or limiting features to IAEA and USNRC licensed spent fuel transport casks or vice-versa. These DTS's have been operated in diverse environments in the United States and throughout the world and have proven to be a significant enhancement in transferring fuel between spent fuel pools, dry storage and hot cell facilities and spent fuel transport casks. Over the years, NAC has successfully and safely transferred more than two thousand fuel assemblies in DTS's. Our latest generation DTS incorporates years of extensive design and operating experience. It consists of a transfer cask with integrated fuel canister grapple, fuel canisters, and facility and cask adapters as well as a complement of related tools and equipment. The transfer cask is used to move irradiated HEU and LEU MTR fuel onsite in those instances where direct loading or unloading of the shipping cask is not possible due to dimensional, weight or other restrictions. The transfer cask is used to move canisters of fuel from the fuel storage location to the shipping cask. Adapters are employed to ensure proper interfacing of the transfer cask with fuel storage locations and shipping casks (NAC-LWT and NLI-1/2). Our existing fuel storage location adapter is designed for use with a storage pool; however, site or equipment specific adapters can easily be developed to allow interfacing with virtually any storage facility. Prior to movement of the first fuel canister in the transfer cask, the shipping cask is prepared for loading by proper set up of the base plate, shipping cask and shipping cask adapter. The fuel canisters are loaded with fuel and then retracted into the transfer cask via the fuel storage location adapter. The transfer cask is then moved to the shipping

Machine assembly with a new material handling mechanism in the sewing machine

Directory of Open Access Journals (Sweden)

Umarova Z.M.

2017-05-01

Full Text Available the paper presents the dynamic model of the machine assembly with a recommended mechanism for moving material and the definition of the law of rails motion under various system parameters. The author has suggested the solution implemented by the system of differential equations numerically on the PC and the system describing the motion of the machine set. Recommended values ​​of the parameters of elastic links of material transfer mechanism have been obtained. The researcher has developed the methods of kinematic and dynamic analysis of the material transfer mechanism with elastic elements of the sewing machine and has approved the parameters and development of the design.

Fuel transfer manipulator for liquid metal nuclear reactors

International Nuclear Information System (INIS)

Sturges, R.H.

1983-01-01

A manipulator for transferring fuel assemblies between inclined fuel chutes of a liquid metal nuclear reactor installation. Hoisting means are mounted on a mount supported by beams pivotably attached by pins to the mount and to the floor in such a manner that pivoting of the beams causes movement and tilting of a hoist tube between positions of alignment with the inclined chutes. (author)

A Computer Model for Analyzing Volatile Removal Assembly

Science.gov (United States)

Guo, Boyun

2010-01-01

A computer model simulates reactional gas/liquid two-phase flow processes in porous media. A typical process is the oxygen/wastewater flow in the Volatile Removal Assembly (VRA) in the Closed Environment Life Support System (CELSS) installed in the International Space Station (ISS). The volatile organics in the wastewater are combusted by oxygen gas to form clean water and carbon dioxide, which is solved in the water phase. The model predicts the oxygen gas concentration profile in the reactor, which is an indicator of reactor performance. In this innovation, a mathematical model is included in the computer model for calculating the mass transfer from the gas phase to the liquid phase. The amount of mass transfer depends on several factors, including gas-phase concentration, distribution, and reaction rate. For a given reactor dimension, these factors depend on pressure and temperature in the reactor and composition and flow rate of the influent.

Full-scale prototyping of the Hitachi dual-purpose metal cask and verification of its heat transfer characteristics

International Nuclear Information System (INIS)

Kumagai, N.; Ishida, N.; Ootsuka, M.; Kamoshida, M.; Hiranuma, T.; Doumori, S.; Hoshikawa, T.; Shimizu, M.; Kashiwakura, J.; Hayashi, M.

2004-01-01

Hitachi has been developing dual-purpose metal casks for transport and storage of spent nuclear fuels. The Hitachi cask, HDP69B can store 69 BWR fuel assemblies. The cask features are as follows. 1) The fuel basket is assembled mainly with plates of borated stainless steel. The plates are not welded, but cross-inserted into each other like the dividers in an egg carton. Since the borated stainless steel has relatively low heat conductivity, aluminum alloy plates are inserted along with some stainless steel plates to enhance heat removal ability. 2) Cured resin blocks are fitted into the inner shell of the cask for neutron shielding of the cask body. The resin blocks are surrounded by an aluminum casing which transfers heat of stored fuel from the inner shell to the outer shell of the cask. The block type shield structure eliminates the need for welding the heat transfer fins to the inner and outer shells. The weldless structures of the HDP69B lead to its enhanced manufacturability, but they complicate the heat transfer characteristics because there are gaps between such components as the aluminum casing and inner/outer shells. We carried out full-scale prototyping of the HDP69B and ran a heat transfer test using the prototype. The purposes of the heat transfer test were to check the heat removal ability of the HDP69B and to verify the safety analysis model for heat removal. Results of the heat transfer test and optimized analysis model for heat transfer characteristics of the HDP69B are the focus of this paper. The heat transfer test is summarized as follows. Sixty nine heaters simulating the shape and heat power of spent fuel assemblies were inserted into the fuel basket. After replacing the inner atmosphere with 0.1 MPa of helium, the heat transfer test was started. About 7 days were required to equilibrate the temperature distribution. The temperature at the center of the basket was 194 C. The results confirmed the HDP69B had sufficient heat removal ability. The

Preliminary risk assessment for nuclear waste disposal in space. Volume I. Executive summary of technical report

International Nuclear Information System (INIS)

Rice, E.E.; Denning, R.S.; Friedlander, A.L.

1982-01-01

Three major conclusions come from this preliminary risk assessment of nuclear waste disposal in space. Preliminary estimates of space disposal risk are low, even with the estimated uncertainty bounds. If calculated mined geologic repository (MGR) release risks remain low, and the EPA requirements continue to be met, then no additional space disposal study effort is warranted. If risks perceived by the public are significant in the acceptance of mined geologic repositories, then consideration of space disposal as an MGR complement is warranted. As a result of this study, the following recommendations are made to NASA and the US DOE: During the continued evaluation of the mined geologic repository risk over the years ahead by DOE, if any significant increase in the calculated health risk is predicted for the MGR, then space disposal should be reevaluated at that time. The risks perceived by the public for the MGR should be evaluated on a broad basis by an independent organization to evaluate acceptance. If, in the future, MGR risks are found to be significant due to some presently unknown technical or social factor, and space disposal is selected as an alternative that may be useful in mitigating the risks, then the following space disposal study activities are recommended: improvement in chemical processing technology for wastes; payload accident response analysis; risk uncertainty analysis for both MGR and space disposal; health risk modeling that includes pathway and dose estimates; space disposal cost modeling; assessment of space disposal perceived (by public) risk benefit; and space systems analysis supporting risk and cost modeling

Cyclodextrin inclusion complexes with thiocholesterol and their self-assembly on gold: A combined electrochemical and lateral force microscopy analysis

International Nuclear Information System (INIS)

Pandey, Rakesh K.; Lakshminarayanan, V.

2014-01-01

The present study is an attempt to understand the properties of an interesting self-assembled monolayer system composed of inclusion complexes of thiocholesterol and cyclodextrins. Cyclodextrins were used as host compound while thiocholesterol was used as the entrant molecule into the cavity of cyclodextrins. The improved electron transfer barrier property towards a redox couple indicates a sturdy inclusion complex monolayer. A very large R ct value, 64.6 kΩ·cm 2 for a redox system was obtained in the case of methyl-β-cyclodextrin and thiocholesterol inclusion complex self-assembled monolayer. A rather low value of capacitance 1.2 μF cm −2 measured in supporting electrolyte further signifies the fact that inclusion complex monolayer is quite impermeable for ionic species. In addition lateral force microscopy combined with force–distance analysis revealed the presence of an interesting mixed hydrophilic/hydrophobic surface. - Highlights: • Self-assembled monolayer of inclusion complexes on gold surface • Lateral force microscopy study of the regions of varying hydrophilicities • Could find applications in patterning surfaces to be hydrophilic/hydrophobic • Improved electron transfer barrier properties

Surface Immobilized His-tagged Azurin as a Model Interface for the Investigation of Vectorial Electron Transfer in Biological Systems

International Nuclear Information System (INIS)

Casalini, Stefano; Berto, Marcello; Kovtun, Alessandro; Operamolla, Alessandra; Di Rocco, Giulia; Facci, Paolo; Liscio, Andrea; Farinola, Gianluca M.; Borsari, Marco; Bortolotti, Carlo A.

2015-01-01

A model system for the electrochemical investigation of vectorial electron transfer in biological systems was designed, assembled and characterized. Gold electrodes, functionalized with a -OCH_3 terminated, aromatic self-assembled monolayer, were used as a substrate for the adsorption of variants of copper-containing, redox metalloprotein azurin. The engineered azurin bears a polyhistidine tag at its C-terminus. Thanks to the presence of the solvent exposed tag, which chelates Cu"2"+ ions in solution, we introduced an exogenous redox centre. The different reduction potentials of the two redox centres and their positioning with respect to the surface are such that electron transfer from the exogenous copper centre and the electrode is mediated by the native azurin active site, closely paralleling electron transfer processes in naturally occurring multicentre metalloproteins.

Self-assembly and energy transfer in artificial light-harvesting complexes of bacteriochlorophyll c with astaxanthin

Czech Academy of Sciences Publication Activity Database

Alster, J.; Polívka, Tomáš; Arellano, J.B.; Hříbek, P.; Vácha, František; Hala, J.; Pšenčík, J.

2012-01-01

Roč. 111, 1-2 (2012), s. 193-204 ISSN 0166-8595 R&D Projects: GA ČR GA206/09/0375 Institutional research plan: CEZ:AV0Z50510513 Keywords : light- harvesting * astaxanthin * self-assembly * bacteriochlorophyll aggregates Subject RIV: BO - Biophysics Impact factor: 3.150, year: 2012

Self-assembly of an electronically conductive network through microporous scaffolds.

Science.gov (United States)

Sebastian, H Bri; Bryant, Steven L

2017-06-15

Electron transfer spanning significant distances through a microporous structure was established via the self-assembly of an electronically conductive iridium oxide nanowire matrix enveloping the pore walls. Microporous formations were simulated using two scaffold materials of varying physical and chemical properties; paraffin wax beads, and agar gel. Following infiltration into the micropores, iridium nanoparticles self-assembled at the pore wall/ethanol interface. Subsequently, cyclic voltammetry was employed to electrochemically crosslink the metal, erecting an interconnected, and electronically conductive metal oxide nanowire matrix. Electrochemical and spectral characterization techniques confirmed the formation of oxide nanowire matrices encompassing lengths of at least 1.6mm, 400× distances previously achieved using iridium nanoparticles. Nanowire matrices were engaged as biofuel cell anodes, where electrons were donated to the nanowires by a glucose oxidizing enzyme. Copyright © 2017 Elsevier Inc. All rights reserved.

Constant system for by-channel thermal-hydraulic calculation of fuel assembly operational conditions in reactors with natural and mixed convection

International Nuclear Information System (INIS)

Bogatyrev, I.L.; Bogoslovskaya, G.P.; Zhukov, A.V.; Sorokin, A.P.; Titov, P.A.

1992-01-01

System of constants for mass, impulse and energy conservation equations (drag, mixing, heat transfer coefficients, azimuthal unquality of temperature) is reported in region with small Re number for wide range of geometrical assembly parameters. This system can be used in subchannel calculations of assemblies with natural and mixed convection under conditions with loss of flow accident. The formulae are compared with experimental data. 30 refs.; 12 figs.; 1 tab

Bouyancy effects on sodium coolant temperature profiles measured in an electrically heated mock-up of a 61-rod breeder reactor blanket assembly

International Nuclear Information System (INIS)

Engel, F.C.; Markley, R.A.; Minushkin, B.

1978-01-01

The paper describes test results selected to demonstrate the effect of buoyancy on the temperature profiles in a 61-rod electrically heated mock-up of an LMFBR radial blanket assembly. In these assemblies, heat transfer occurs over a wide range of complex operating conditions. The range and complexity of conditions are the result of the steep flux and power gradients which are an inherent feature of the blanket region and the power generation level in an assembly which can vary from 20 to 1100 kW

Pattern transfer with stabilized nanoparticle etch masks

International Nuclear Information System (INIS)

Hogg, Charles R; Majetich, Sara A; Picard, Yoosuf N; Narasimhan, Amrit; Bain, James A

2013-01-01

Self-assembled nanoparticle monolayer arrays are used as an etch mask for pattern transfer into Si and SiO x substrates. Crack formation within the array is prevented by electron beam curing to fix the nanoparticles to the substrate, followed by a brief oxygen plasma to remove excess carbon. This leaves a dot array of nanoparticle cores with a minimum gap of 2 nm. Deposition and liftoff can transform the dot array mask into an antidot mask, where the gap is determined by the nanoparticle core diameter. Reactive ion etching is used to transfer the dot and antidot patterns into the substrate. The effect of the gap size on the etching rate is modeled and compared with the experimental results. (paper)

The GTZAN dataset

DEFF Research Database (Denmark)

Sturm, Bob L.

2013-01-01

The GTZAN dataset appears in at least 100 published works, and is the most-used public dataset for evaluation in machine listening research for music genre recognition (MGR). Our recent work, however, shows GTZAN has several faults (repetitions, mislabelings, and distortions), which challenge...... of GTZAN, and provide a catalog of its faults. We review how GTZAN has been used in MGR research, and find few indications that its faults have been known and considered. Finally, we rigorously study the effects of its faults on evaluating five different MGR systems. The lesson is not to banish GTZAN...

Fixed mask assembly research for APS insertion devices

International Nuclear Information System (INIS)

Kuzay, T.M.

1992-01-01

The Fixed Mask Assembly (FMA) is the first component to interact with the photon beam. Two sets of a pair of FMA channels, vertically and horizontally disposed, contain the beam rather than define it. They are subject to very large heat fluxes during containment. In current practice, the FMA channels are made of heavy, seamless copper, have rectangular cross-sections, and are cooled internally with water. Channels are set at grazing angles ranging from I to 6 degrees with respect to the beam, depending on the type of insertion device. APS insertion devices will impose higher heat fluxes on FMAS. Therefore, a need exists to improve the FMA engineering, keeping in mind the current design criteria and philosophy of FMAS. Preliminary analysis of current heat transfer practice indicates that the major resistance to heat transfer is on the coolant side. Therefore, FMA cooling would benefit from enhanced heat transfer on the coolant side. With this principle in mind, an experimental program has been undertaken to explore the feasibility of using high-performance copper tube configurations which are expected to yield heat transfer coefficients, open-quotes hclose quotes, in single phase flow systems 2 to 5(?) times higher than equivalent plain tubes. In this report, the experimental scope and a preliminary analysis of high-performance copper tube configurations are described

Nutrient uptake by intact mycorrhizal Pinus sylvestris seedlings: a diagnostic tool to detect copper toxicity.

Science.gov (United States)

Van Tichelen, Katia K.; Vanstraelen, Tom; Colpaert, Jan V.

1999-03-01

We developed a nondestructive method for detecting early toxic effects of inflethal copper (Cu) concentrations on ectomycorrhizal and non-mycorrhizal (NM) Scots pine (Pinus sylvestris L.) seedlings. The fungal symbionts examined were Paxillus involutus (Fr.) Fr., Suillus luteus (Fr.) S.F. Gray and Thelephora terrestris (Ehrh.) Fr. The accumulation of Cu in needles and fungal development (ergosterol) in roots and infstrate were assessed. Inorganic phosphate (P(i)) and ammonium (NH(4) (+)) uptake capacities were determined in a semi-hydroponic cultivation system on intact P-limited plants that were exposed for 3 weeks to 0.32 (control), 8 or 16 &mgr;moles Cu(2+). Short-term effects of a 1-hour exposure to 32 &mgr;moles Cu(2+) on nutrient uptake rates were also determined. None of the Cu(2+) treatments affected plant growth or root ergosterol concentrations. The active fungal biomass in infstrate invaded by S. luteus was reduced by 50% in the 16 &mgr;M Cu(2+) treatment compared with the control treatment; however, colonization by S. luteus prevented an increased accumulation of Cu in the needles. In contrast, the 16 &mgr;M Cu(2+) treatment caused a 2.2-fold increase in needle Cu concentration in NM plants. Ergosterol concentrations in the infstrate colonized by P. involutus and T. terrestris were not affected by 16 &mgr;molar Cu(2+). Although P. involutus and T. terrestris were less sensitive to Cu(2+) than S. luteus, T. terrestris did not prevent the accumulation of Cu in needles of its host plant in the 16 &mgr;molar Cu(2+) treatment. Mycorrhizal plants consistently had higher P(i) and NH(4) (+) uptake capacities than NM plants. In the control treatment, specific P(i) uptake rates were almost 10, 4 and 3 times higher in plants associated with P. involutus, S. luteus and T. terrestris, respectively, than in NM plants, and specific NH(4) (+) uptake rates were about 2, 2 and 5 times higher, respectively, than those of NM seedlings. Compared with the corresponding

Refinements to temperature calculations of spent fuel assemblies when in a stagnant gas environment

International Nuclear Information System (INIS)

Rhodes, C.A.; Haire, M.J.

1984-01-01

Undesirably high temperatures are possible in irradiated fuel assemblies because of the radioactive decay of fission products formed while in the reactor. The COXPRO computer code has been used for some time to calculate temperatures in spent fuel when the fuel is suspended in a stagnant gas environment. This code assumed radiation to be the only mode of heat dissipation within the fuel pin bundle. Refinements have been made to include conduction as well as radiation heat transfer within this code. Comparison of calculated and measured temperatures in four separate and independent tests indicate that maximum fuel assembly temperatures can be predicted to within about 6%. 2 references, 5 figures

Inspection experience with RA-3 spent nuclear fuel assemblies at CNEA's central storage facility

International Nuclear Information System (INIS)

Novara, Oscar; LaFuente, Jose; Large, Steve; Andes, Trent; Messick, Charles

2000-01-01

Aluminum-based spent nuclear fuel from Argentina's RA-3 research reactor is to be shipped to the Savannah River Site near Aiken, South Carolina, USA. The spent nuclear fuel contains highly enriched uranium of U.S. origin and is being returned under the US Department of Energy's Foreign Research Reactor/Domestic Research Reactor (FRR/DRR) Receipt Program. An intensive inspection of 207 stored fuel assemblies was conducted to assess shipping cask containment limitations and assembly handling considerations. The inspection was performed with video equipment designed for remote operation, high portability, easy setup and usage. Fuel assemblies were raised from their vertical storage tubes, inspected by remote video, and then returned to their original storage tube or transferred to an alternate location. The inspections were made with three simultaneous video systems, each with dedicated viewing, digital recording, and tele-operated control from a shielded location. All 207 fuel assemblies were safely and successfully inspected in fifteen working days. Total dose to personnel was about one-half of anticipated dose. (author)

Flexible transfer of aligned carbon nanotube films for integration at lower temperature

International Nuclear Information System (INIS)

Chai Yang; Gong Jingfeng; Zhang Kai; Chan, Philip C H; Yuen, Matthew M F

2007-01-01

The high growth temperature of carbon nanotubes (CNTs) hinders their direct assembly on temperature-sensitive substrates. We present a method to transfer an aligned CNT film at room temperature to overcome this problem. Using a 'liftoff' technique with hydrofluoric acid solution, we separate the aligned CNT film from the silicon substrate. The lifted-off CNT film is suspended in water, remaining intact and aligned due to the crowding effect. We then transfer the suspended film to various substrates that are sensitive to high temperature. To illustrate the quality of the transferred CNT film, we demonstrate that the thermal interface resistance of the transferred CNT film is comparable with that of as-grown CNT film. This transfer process can be extended to many microelectronics applications, such as field emission devices, integrated circuit interconnects and sensors, requiring processing temperatures not compatible with CNT growth

Mobius Assembly: A versatile Golden-Gate framework towards universal DNA assembly.

Directory of Open Access Journals (Sweden)

Andreas I Andreou

Full Text Available Synthetic biology builds upon the foundation of engineering principles, prompting innovation and improvement in biotechnology via a design-build-test-learn cycle. A community-wide standard in DNA assembly would enable bio-molecular engineering at the levels of predictivity and universality in design and construction that are comparable to other engineering fields. Golden Gate Assembly technology, with its robust capability to unidirectionally assemble numerous DNA fragments in a one-tube reaction, has the potential to deliver a universal standard framework for DNA assembly. While current Golden Gate Assembly frameworks (e.g. MoClo and Golden Braid render either high cloning capacity or vector toolkit simplicity, the technology can be made more versatile-simple, streamlined, and cost/labor-efficient, without compromising capacity. Here we report the development of a new Golden Gate Assembly framework named Mobius Assembly, which combines vector toolkit simplicity with high cloning capacity. It is based on a two-level, hierarchical approach and utilizes a low-frequency cutter to reduce domestication requirements. Mobius Assembly embraces the standard overhang designs designated by MoClo, Golden Braid, and Phytobricks and is largely compatible with already available Golden Gate part libraries. In addition, dropout cassettes encoding chromogenic proteins were implemented for cost-free visible cloning screening that color-code different cloning levels. As proofs of concept, we have successfully assembled up to 16 transcriptional units of various pigmentation genes in both operon and multigene arrangements. Taken together, Mobius Assembly delivers enhanced versatility and efficiency in DNA assembly, facilitating improved standardization and automation.

Music genre recognition with risk and rejection

DEFF Research Database (Denmark)

Sturm, Bob L.

2013-01-01

We explore risk and rejection for music genre recognition (MGR) within the minimum risk framework of Bayesian classification. In this way, we attempt to give an MGR system knowledge that some misclassifications are worse than others, and that deferring classification to an expert may be a better...

Outlet temperature measurement correction of Gd fuel assemblies at Dukovany NPP

International Nuclear Information System (INIS)

Jurickova, M.

2008-01-01

In year 2006 we started data processing from the Dukovany NPP operating history database that contained data from the old measurement system VK3 and the new Scorpio-VVER. The work has been done in cooperation with the reactor physicists at Dukovany NPP. Obtained data from database were compared with calculated parameters from 3D diffusion macrocode Mobydick. During the data processing it was found that the Gd fuel assemblies have different time plot of measured assembly outlet temperature compared to the non-Gd fuel assemblies. Experimental studies in RRC KI found that there is insufficient coolant mixing in the region from the fuel bundle to the fuel assembly thermocouple. Due to this fact the thermocouple measure temperature is systematically higher than real temperature. There are two methods to solve this problem. The first method analyses the flow and heat transfer in the region from the fuel bundle to the fuel assembly thermocouple - this method is developed in Skoda JS. The second method statistically studies differences between the measured and calculated temperature by the Mobydick code using the operational history database. Our study is focused on the second method. Several calculation methods for the correction of measured assembly outlet temperature were developed. All correction methods were applied to the measured temperatures from the Dukovany NPP operating history database and the methods were mutually compared. In near future it is planned to compare results of our chosen correction method with modeling method, which is developing in Skoda JS and it is planned to validate both of them. Consequently, the one of these correction methods will be implemented in the modernized Scorpio-VVER for Dukovany NPP. (author)

Comparison of Interfacial Electron Transfer Efficiency in [Fe(ctpy)2]2+-TiO2 and [Fe(cCNC)2]2+-TiO2 Assemblies: Importance of Conformational Sampling.

Science.gov (United States)

Mukherjee, Sriparna; Liu, Chang; Jakubikova, Elena

2018-02-22

Fe(II)-polypyridines have limited applications as chromophores in dye-sensitized solar cells due to the short lifetimes (∼100 fs) of their photoactive metal-to-ligand charge transfer (MLCT) states formed upon photoexcitation. Recently, a 100-fold increase in the MLCT lifetime was observed in a [Fe(CNC) 2 ] 2+ complex (CNC = 2,6-bis(3-methylimidazole-1-ylidine)pyridine) which has strong σ-donating N-heterocyclic carbene ligand in comparison to the weaker field parent [Fe(tpy) 2 ] 2+ complex (tpy = 2,2':6',2″-terpyridine). This study utilizes density functional theory (DFT), time-dependent DFT, and quantum dynamics simulations to investigate the interfacial electron transfer (IET) in [Fe(cCNC) 2 ] 2+ (cCNC = 4'-carboxy-2,6-bis(3-methylimidazole-1-ylidine)pyridine) and [Fe(ctpy) 2 ] 2+ (ctpy = 4'-carboxy-2,2':6',2″-terpyridine) sensitized TiO 2 . Our results suggest that the replacement of tpy by CNC ligand does not significantly speed up the IET kinetics in the [Fe(cCNC) 2 ] 2+ -TiO 2 assembly in comparison to the [Fe(ctpy) 2 ] 2+ -TiO 2 analogue. The high IET efficiency in the [Fe(cCNC) 2 ] 2+ -TiO 2 assemblies is therefore due to longer lifetime of [Fe(cCNC) 2 ] 2+ photoactive 3 MLCT states rather than faster electron injection kinetics. It was also found that the inclusion of conformational sampling in the computational model is important for proper description of the IET processes in these systems, as the models relying on the use of only fully optimized structures may yield misleading results. The simulations presented in this work also illustrate various pitfalls of utilizing properties such as electronic coupling, number of available acceptor states, and driving force, as well as calculations based on Fermi's golden rule framework, to reach conclusions on the IET efficiency in dye-semiconductor systems.

The Winfrith 9MW heat transfer rig

International Nuclear Information System (INIS)

Obertelli, J.D.

1976-01-01

The Winfrith 9MW Rig is used for studying heat transfer and flow resistance in a variety of test sections at system pressures up to 68 bar. The basic rig and its instrumentation are discussed together with the characteristics of the test section design. The rig has been used in studies involving the full scale simulation of Steam Generating Heavy Water (SGHW) fuel assemblies and the paper discusses the measurements made in this type of study. (author)

Synthesis and self-assembly of four-armed star copolymer based on poly(ethylene brassylate) hydrophobic block as potential drug carries

Energy Technology Data Exchange (ETDEWEB)

Chen, Jiucun, E-mail: chenjc@swu.edu.cn; Li, Junzhi; Liu, Jianhua; Weng, Bo; Xu, Liqun [Southwest University, Institute for Clean Energy & Advanced Materials (China)

2016-05-15

A novel well-defined four-armed star poly(ethylene brassylate)-b-poly(poly(ethylene glycol)methyl ether methacrylate) (s-PEB-b-P(PEGMA)) was synthesized and self-assembled via the combination of ring-opening polymerization and reversible addition-fragmentation chain transfer polymerization (RAFT) in this work. It proceeded firstly with the synthesis of hydrophobic four-armed star homopolymer of ethylene brassylate (EB) via ROP with organic catalyst, followed by the esterification reaction of s-PEB with chain transfer agent. Afterward, RAFT polymerization of PEGMA monomer was initialed using PEB-based macro-RAFT agent, resulting in the target amphiphilic four-armed star copolymer. The obtained s-PEB-b-P(PEGMA) can assemble into micelles with PEB segments as core and P(PEGMA) segments as shell in aqueous solution. The self-assembly behavior was studied by dynamic light scattering and transmission electron microscope. The micelles of s-PEB-b-P(PEGMA) exhibited higher loading capacity of the anticancer drug doxorubicin (DOX). The investigation of DOX release from the micelles demonstrated that the release rate of the hydrophobic drug could be effectively controlled.Graphical Abstract.

Handling apparatus for fuel assemblies in a core

International Nuclear Information System (INIS)

Hatakenaka, Hideo.

1975-01-01

Object: To prevent an occurrence of a cloud as well as trouble in outflow of cooling water at the time of failure, in a window through which the operation of a collet installing and removing mechanism is monitored. Structure: A monitoring window comprises a pair of transparent window panes between which is interposed a non-compressive transparent fluid. With this construction, when the collet installing and removing mechanism within a container is operated while illuminating it by light means and monitoring it by a television camera to connect a fuel assembly with a shielding plug, and even if one transparent window pane should be failed as a result of trouble, the other transparent window pane prevents outflow of cooling water within a fuel transferring transfer port, and at the same time, the scattering force of fragments of failed transparent window pane is attenuated by the non-compressive transparent body within the monitoring window chamber. (Hanada, M.)

Effective void fraction for a BWR assembly with boiling in the bypass region

International Nuclear Information System (INIS)

Galperin, A.; Segev, M.; Knoglinger, E.

1991-09-01

Average BWR assembly cross-sections for nominal conditions, namely for zero bypass void, can be utilised in the analysis of transient conditions with boiling in the bypass. A model is developed to yield an effective channel void for such conditions. The use of this void in conjunction with the 'nominal conditions' cross section library approximately preserves the assembly K-infinity corresponding to the true channel and bypass voids. The effective void is an augmentation of the actual channel void. The augment is proportional to the bypass-to-channel volume ratio, to the bypass void, and to a weight W which is introduced to quantify the fact that a water molecule in the bypass has a different assembly criticality worth than one in the channel. The formula developed is superior to the practice of choosing W=1, namely a simple, non-weighted, transfer of water from channel to bypass. The use of this approximate effective channel void reproduces actual K-infinity values of assemblies to better than 5 mk, whereas the use of a simple model sometimes misspredicts the assembly K-infinity by 40 mK. The effective void model cannot handle cases in which both channel and bypass void value are high, simply because then the effective void α ch eff becomes meaningless. A method to treat the α eff >1 domain is developed by which corrections to cross sections are provided. Such corrections are synthesised as functions of the assembly parameters. (author) figs., tabs., refs

A Survey of Evaluation in Music Genre Recognition

DEFF Research Database (Denmark)

Sturm, Bob L.

2012-01-01

Much work is focused upon music genre recognition (MGR) from audio recordings, symbolic data, and other modalities. While reviews have been written of some of this work before, no survey has been made of the approaches to evaluating approaches to MGR. This paper compiles a bibliography of work...

Application of Assembly of Finite Element Methods on Graphics Processors for Real-Time Elastodynamics

KAUST Repository

Cecka, Cris

2012-01-01

This chapter discusses multiple strategies to perform general computations on unstructured grids, with specific application to the assembly of matrices in finite element methods (FEMs). It reviews and applies two methods for assembly of FEMs to produce and accelerate a FEM model for a nonlinear hyperelastic solid where the assembly, solution, update, and visualization stages are performed solely on the GPU, benefiting from speed-ups in each stage and avoiding costly GPUCPU transfers of data. For each method, the chapter discusses the NVIDIA GPU hardware\\'s limiting resources, optimizations, key data structures, and dependence of the performance with respect to problem size, element size, and GPU hardware generation. Furthermore, this chapter informs potential users of the benefits of GPU technology, provides guidelines to help them implement their own FEM solutions, gives potential speed-ups that can be expected, and provides source code for reference. © 2012 Elsevier Inc. All rights reserved.

Self-assembly of self-assembled molecular triangles

Indian Academy of Sciences (India)

While the solution state structure of 1 can be best described as a trinuclear complex, in the solidstate well-fashioned intermolecular - and CH- interactions are observed. Thus, in the solid-state further self-assembly of already self-assembled molecular triangle is witnessed. The triangular panels are arranged in a linear ...

Evaluation of nine popular de novo assemblers in microbial genome assembly.

Science.gov (United States)

Forouzan, Esmaeil; Maleki, Masoumeh Sadat Mousavi; Karkhane, Ali Asghar; Yakhchali, Bagher

2017-12-01

Next generation sequencing (NGS) technologies are revolutionizing biology, with Illumina being the most popular NGS platform. Short read assembly is a critical part of most genome studies using NGS. Hence, in this study, the performance of nine well-known assemblers was evaluated in the assembly of seven different microbial genomes. Effect of different read coverage and k-mer parameters on the quality of the assembly were also evaluated on both simulated and actual read datasets. Our results show that the performance of assemblers on real and simulated datasets could be significantly different, mainly because of coverage bias. According to outputs on actual read datasets, for all studied read coverages (of 7×, 25× and 100×), SPAdes and IDBA-UD clearly outperformed other assemblers based on NGA50 and accuracy metrics. Velvet is the most conservative assembler with the lowest NGA50 and error rate. Copyright © 2017. Published by Elsevier B.V.

Statement to the fifty-fifth session of the United Nations General Assembly

International Nuclear Information System (INIS)

ElBaradei, M.

2000-01-01

In his statement to the fifty-fifth session of the United Nations General Assembly, the Director General of the IAEA briefly presented the three fundamental functions of the IAEA, namely: its role as a catalyst for the development and transfer of peaceful nuclear technologies, the efforts to prevent the proliferation of nuclear weapons and move towards nuclear disarmament, and the work to build and maintain a global nuclear safety regime

Dynamic DNA devices and assemblies formed by shape-complementary, non-base pairing 3D components

Science.gov (United States)

Gerling, Thomas; Wagenbauer, Klaus F.; Neuner, Andrea M.; Dietz, Hendrik

2015-03-01

We demonstrate that discrete three-dimensional (3D) DNA components can specifically self-assemble in solution on the basis of shape-complementarity and without base pairing. Using this principle, we produced homo- and heteromultimeric objects, including micrometer-scale one- and two-stranded filaments and lattices, as well as reconfigurable devices, including an actuator, a switchable gear, an unfoldable nanobook, and a nanorobot. These multidomain assemblies were stabilized via short-ranged nucleobase stacking bonds that compete against electrostatic repulsion between the components’ interfaces. Using imaging by electron microscopy, ensemble and single-molecule fluorescence resonance energy transfer spectroscopy, and electrophoretic mobility analysis, we show that the balance between attractive and repulsive interactions, and thus the conformation of the assemblies, may be finely controlled by global parameters such as cation concentration or temperature and by an allosteric mechanism based on strand-displacement reactions.

Layer-by-layer assembled multilayers using catalase-encapsulated gold nanoparticles

International Nuclear Information System (INIS)

Kim, Sungwoo; Park, Jeongju; Cho, Jinhan

2010-01-01

We introduce a novel and versatile approach for the preparation of multilayers, based on catalase-encapsulated gold nanoparticles (CAT-Au NP ), allowing electrostatic charge reversal and structural transformation through pH adjustment. CAT-Au NP , which are synthesized directly from CAT stabilizer, can be electrostatically assembled with anionic and cationic PEs as a result of the charge reversal of the catalase stabilizers through pH control. In particular, at pH 5.2, near the pI of catalase, dispersed CAT-Au NP are structurally transformed into colloidal or network CAT-Au NP nanocomposites. Furthermore, we demonstrate that the layer-by-layer assembled multilayers composed of PEs and CAT-Au NP induce an effective electron transfer between CAT and the electrode as well as a high loading of CAT and Au NP , and resultantly exhibit a highly catalytic activity toward H 2 O 2 .

A conceptual design of assembly strategy and dedicated tools for assembly of 40o sector

International Nuclear Information System (INIS)

Park, H.K.; Nam, K.O.; Kim, D.J.; Ahn, H.J.; Lee, J.H.; Im, K.; Shaw, R.

2010-01-01

The International Thermanuclear Experimental Reactor (ITER) tokamak device is composed of 9 vacuum vessel (VV)/toroidal field coils (TFCs)/vacuum vessel thermal shields (VVTS) 40 o sectors. Each VV/TFCs/VVTS 40 o sector is made up of one 40 o VV, two 20 o TFCs and associated VVTS segments. The 40 o sectors are sub-assembled at assembly hall respectively and then nine 40 o sectors sub-assembled at assembly hall are finally assembled at tokamak in-pit hall. The assembly strategy and tools for the 40 o sector sub-assembly and final assembly should be developed to satisfy the basic assembly requirements of the ITER tokamak device. Accordingly, the purpose-built assembly tools should be designed and manufactured considering assembly plan, available space, cost, safety, easy operation, efficient maintenance, and so on. The 40 o sector assembly tools are classified into 2 groups. One group is the sub-assembly tools including upending tool, lifting tool, sub-assembly tool, VV supports and bracing tools used at assembly hall and the other group is the in-pit assembly tools including lifting tool, central column, radial beams and their supports. This paper describes the current status of the assembly strategy and major tools for the VV/TFCs/VVTS 40 o sector assembly at in-pit hall and assembly hall. The conceptual design of the major assembly tools and assembly process at assembly hall and tokamak in-pit hall are presented also.

International Human Mission to Mars: Analyzing A Conceptual Launch and Assembly Campaign

Science.gov (United States)

Cates, Grant; Stromgren, Chel; Arney, Dale; Cirillo, William; Goodliff, Kandyce

2014-01-01

In July of 2013, U.S. Congressman Kennedy (D-Mass.) successfully offered an amendment to H.R. 2687, the National Aeronautics and Space Administration Authorization Act of 2013. "International Participation—The President should invite the United States partners in the International Space Station program and other nations, as appropriate, to participate in an international initiative under the leadership of the United States to achieve the goal of successfully conducting a crewed mission to the surface of Mars." This paper presents a concept for an international campaign to launch and assemble a crewed Mars Transfer Vehicle. NASA’s “Human Exploration of Mars: Design Reference Architecture 5.0” (DRA 5.0) was used as the point of departure for this concept. DRA 5.0 assumed that the launch and assembly campaign would be conducted using NASA launch vehicles. The concept presented utilizes a mixed fleet of NASA Space Launch System (SLS), U.S. commercial and international launch vehicles to accomplish the launch and assembly campaign. This concept has the benefit of potentially reducing the campaign duration. However, the additional complexity of the campaign must also be considered. The reliability of the launch and assembly campaign utilizing SLS launches augmented with commercial and international launch vehicles is analyzed and compared using discrete event simulation.

Fuel injection assembly for use in turbine engines and method of assembling same

Science.gov (United States)

Berry, Jonathan Dwight; Johnson, Thomas Edward; York, William David; Uhm, Jong Ho

2015-12-15

A fuel injection assembly for use in a turbine engine is provided. The fuel injection assembly includes an end cover, an endcap assembly, a fluid supply chamber, and a plurality of tube assemblies positioned at the endcap assembly. Each of the tube assemblies includes housing having a fuel plenum and a cooling fluid plenum. The cooling fluid plenum is positioned downstream from the fuel plenum and separated from the fuel plenum by an intermediate wall. The plurality of tube assemblies also include a plurality of tubes that extends through the housing. Each of the plurality of tubes is coupled in flow communication with the fluid supply chamber and a combustion chamber positioned downstream from the tube assembly. The plurality of tube assemblies further includes an aft plate at a downstream end of the cooling fluid plenum. The plate includes at least one aperture.

Direct visualization of efficient energy transfer in single oligo(p-phenylene vinylene) vesicles

NARCIS (Netherlands)

Hoeben, F.J.M.; Shklyarevskiy, I.O.; Pouderoijen, M.J.; Engelkamp, H.; Schenning, A.P.H.J.; Christianen, P.C.M.; Maan, J.C.; Meijer, E.W.

2006-01-01

Monitoring self-assembled objects: Optical studies and scanning confocal microscopy have been used to monitor intermolecular energy transfer (ENT) in mixed vesicles of donor/acceptor oligo(p-phenylene vinylene)s (OPVs) in water (see picture) over time. This probing of the ongoing exchange process

An electrochemical aptasensor for chiral peptide detection using layer-by-layer assembly of polyelectrolyte-methylene blue/polyelectrolyte-graphene multilayer

International Nuclear Information System (INIS)

Qin Haixia; Liu Jiyang; Chen Chaogui; Wang Jiahi; Wang Erkang

2012-01-01

Highlights: ► An electrochemical aptasensor for selective detection of peptide is constructed. ► This aptasensor is based on grapheme multilayer via layer-by-layer assembly. ► Such multilayer facilitates electron transfer and provides more adsorption sites. - Abstract: Here we demonstrate for the first time that by physically adsorbing aptamer onto conductive film assembled via alternate adsorption of graphene/polyelectrolyte and methylene blue/polyelectrolyte, a label-free electrochemical aptasensor with high sensitivity and selectivity for peptide detection is constructed. Graphene multilayer derived from layer-by-layer assembly has played significant roles in this sensing strategy: allowing accumulation of methylene blue, facilitating electron transfer and providing much more adsorption site. As compared to previous electrochemical aptasensors, the current sensor based on graphene multilayer alternated with electroactive molecule layer offers extremely high capability for sensitive detection of target without interference of environmental surrounding. This electroactive probe-confined graphene multilayer confers great flexibility to combine with differential pulse voltammetry (DPV) together. In the presence of target D entiomer of arginine vasopressin (D-VP), the binding of peptide to aptamer block the electron transfer process of MB, leading to decreased current peak of DPV. By this way, this electrochemical aptasensor based on electroactive molecule-intercalated graphene multilayer provide highly sensitive and specific detection of D-VP with the lowest detectable concentration of 1 ng mL −1 and a wide detection range from 1 to 265 ng mL −1 .

AutoAssemblyD: a graphical user interface system for several genome assemblers.

Science.gov (United States)

Veras, Adonney Allan de Oliveira; de Sá, Pablo Henrique Caracciolo Gomes; Azevedo, Vasco; Silva, Artur; Ramos, Rommel Thiago Jucá

2013-01-01

Next-generation sequencing technologies have increased the amount of biological data generated. Thus, bioinformatics has become important because new methods and algorithms are necessary to manipulate and process such data. However, certain challenges have emerged, such as genome assembly using short reads and high-throughput platforms. In this context, several algorithms have been developed, such as Velvet, Abyss, Euler-SR, Mira, Edna, Maq, SHRiMP, Newbler, ALLPATHS, Bowtie and BWA. However, most such assemblers do not have a graphical interface, which makes their use difficult for users without computing experience given the complexity of the assembler syntax. Thus, to make the operation of such assemblers accessible to users without a computing background, we developed AutoAssemblyD, which is a graphical tool for genome assembly submission and remote management by multiple assemblers through XML templates. AssemblyD is freely available at https://sourceforge.net/projects/autoassemblyd. It requires Sun jdk 6 or higher.

Electrosynthesis of acetate from CO2 by a highly structured biofilm assembled with reduced graphene oxide–tetraethylene pentamine

DEFF Research Database (Denmark)

Chen, Leifeng; Tremblay, Pier-Luc; Mohanty, Soumyaranjan

2016-01-01

transfer from the cathode to microbes. Here, carbon cloth cathodes modified with reduced graphene oxide functionalized with tetraethylene pentamine (rGO-TEPA) were readily self-assembled in the cathodic chamber of a MES reactor. Electroactive biofilms with unique spatial arrangement were subsequently...

Assembly, alignment and test of the Transiting Exoplanet Survey Satellite (TESS) optical assemblies

Science.gov (United States)

Balonek, Gregory; Brown, Joshua J.; Andre, James E.; Chesbrough, Christian D.; Chrisp, Michael P.; Dalpiaz, Michael; Lennon, Joseph; Richards, B. C.; Clark, Kristin E.

2017-08-01

The Transiting Exoplanet Survey Satellite (TESS) will carry four visible waveband, seven-element, refractive F/1.4 lenses, each with a 34 degree diagonal field of view. This paper describes the methods used for the assembly, alignment and test of the four flight optical assemblies. Prior to commencing the build of the four flight optical assemblies, a Risk Reduction Unit (RRU) was successfully assembled and tested [1]. The lessons learned from the RRU were applied to the build of the flight assemblies. The main modifications to the flight assemblies include the inking of the third lens element stray light mitigation, tighter alignment tolerances, and diamond turning for critical mechanical surfaces. Each of the optical assemblies was tested interferometrically and measured with a low coherence distance measuring interferometer (DMI) to predict the optimal shim thickness between the lens assembly and detector before -75°C environmental testing. In addition to individual test data, environmental test results from prior assemblies allow for the exploration of marginal performance differences between each of the optical assemblies.

SWAP-Assembler: scalable and efficient genome assembly towards thousands of cores.

Science.gov (United States)

Meng, Jintao; Wang, Bingqiang; Wei, Yanjie; Feng, Shengzhong; Balaji, Pavan

2014-01-01

There is a widening gap between the throughput of massive parallel sequencing machines and the ability to analyze these sequencing data. Traditional assembly methods requiring long execution time and large amount of memory on a single workstation limit their use on these massive data. This paper presents a highly scalable assembler named as SWAP-Assembler for processing massive sequencing data using thousands of cores, where SWAP is an acronym for Small World Asynchronous Parallel model. In the paper, a mathematical description of multi-step bi-directed graph (MSG) is provided to resolve the computational interdependence on merging edges, and a highly scalable computational framework for SWAP is developed to automatically preform the parallel computation of all operations. Graph cleaning and contig extension are also included for generating contigs with high quality. Experimental results show that SWAP-Assembler scales up to 2048 cores on Yanhuang dataset using only 26 minutes, which is better than several other parallel assemblers, such as ABySS, Ray, and PASHA. Results also show that SWAP-Assembler can generate high quality contigs with good N50 size and low error rate, especially it generated the longest N50 contig sizes for Fish and Yanhuang datasets. In this paper, we presented a highly scalable and efficient genome assembly software, SWAP-Assembler. Compared with several other assemblers, it showed very good performance in terms of scalability and contig quality. This software is available at: https://sourceforge.net/projects/swapassembler.

Assembly tool design

International Nuclear Information System (INIS)

Kanamori, Naokazu; Nakahira, Masataka; Ohkawa, Yoshinao; Tada, Eisuke; Seki, Masahiro

1996-06-01

The reactor core of the International Thermonuclear Experimental Reactor (ITER) is assembled with a number of large and asymmetric components within a tight tolerance in order to assure the structural integrity for various loads and to provide the tritium confinement. In addition, the assembly procedure should be compatible with remote operation since the core structures will be activated by 14-MeV neutrons once it starts operation and thus personal access will be prohibited. Accordingly, the assembly procedure and tool design are quite essential and should be designed from the beginning to facilitate remote operation. According to the ITER Design Task Agreement, the Japan Atomic Energy Research Institute (JAERI) has performed design study to develop the assembly procedures and associated tool design for the ITER tokamak assembly. This report describes outlines of the assembly tools and the remaining issues obtained in this design study. (author)

Gene Transfer in Eukaryotic Cells Using Activated Dendrimers

Science.gov (United States)

Dennig, Jörg

Gene transfer into eukaryotic cells plays an important role in cell biology. Over the last 30 years a number of transfection methods have been developed to mediate gene transfer into eukaryotic cells. Classical methods include co-precipitation of DNA with calcium phosphate, charge-dependent precipitation of DNA with DEAE-dextran, electroporation of nucleic acids, and formation of transfection complexes between DNA and cationic liposomes. Gene transfer technologies based on activated PAMAM-dendrimers provide another class of transfection reagents. PAMAM-dendrimers are highly branched, spherical molecules. Activation of newly synthesized dendrimers involves hydrolytic removal of some of the branches, and results in a molecule with a higher degree of flexibility. Activated dendrimers assemble DNA into compact structures via charge interactions. Activated dendrimer - DNA complexes bind to the cell membrane of eukaryotic cells, and are transported into the cell by non-specific endocytosis. A structural model of the activated dendrimer - DNA complex and a potential mechanism for its uptake into cells will be discussed.

Application of Sensor Technology for the Efficient Positioningand Assembling of Ship Blocks

Directory of Open Access Journals (Sweden)

Sangdon Lee

2010-09-01

Full Text Available This paper proposes the application of sensor technology to assemble ship blocks efficiently. A sensor-based monitoring system is designed and implemented to improve shipbuilding productivity by reducing the labor cost for the adjustment of adequate positioning between ship blocks during pre-erection or erection stage. For the real-time remote monitoring of relative distances between two ship blocks, sensor nodes are applied to measure the distances between corresponding target points on the blocks. Highly precise positioning data can be transferred to a monitoring server via wireless network, and analyzed to support the decision making which needs to determine the next construction process; further adjustment or seam welding between the ship blocks. The developed system is expected to put to practical use, and increase the productivity during ship blocks assembly.

Virus-Assembled Flexible Electrode-Electrolyte Interfaces for Enhanced Polymer-Based Battery Applications

Directory of Open Access Journals (Sweden)

Ayan Ghosh

2012-01-01

Full Text Available High-aspect-ratio cobalt-oxide-coated Tobacco mosaic virus (TMV- assembled polytetrafluoroethylene (PTFE nonstick surfaces were integrated with a solvent-free polymer electrolyte to create an anode-electrolyte interface for use in lithium-ion batteries. The virus-assembled PTFE surfaces consisted primarily of cobalt oxide and were readily intercalated with a low-molecular-weight poly (ethylene oxide (PEO based diblock copolymer electrolyte to produce a solid anode-electrolyte system. The resulting polymer-coated virus-based system was then peeled from the PTFE backing to produce a flexible electrode-electrolyte component. Electrochemical studies indicated the virus-structured metal-oxide PEO-based interface was stable and displayed robust charge transfer kinetics. Combined, these studies demonstrate the development of a novel solid-state electrode architecture with a unique peelable and flexible processing attribute.

Emitter and absorber assembly for multiple self-dual operation and directional transparency

Science.gov (United States)

Kalozoumis, P. A.; Morfonios, C. V.; Kodaxis, G.; Diakonos, F. K.; Schmelcher, P.

2017-03-01

We demonstrate how to systematically design wave scattering systems with simultaneous coherent perfect absorbing and lasing operation at multiple and prescribed frequencies. The approach is based on the recursive assembly of non-Hermitian emitter and absorber units into self-dual emitter-absorber trimers at different composition levels, exploiting the simple structure of the corresponding transfer matrices. In particular, lifting the restriction to parity-time-symmetric setups enables the realization of emitter and absorber action at distinct frequencies and provides flexibility with respect to the choice of realistic parameters. We further show how the same assembled scatterers can be rearranged to produce unidirectional and bidirectional transparency at the selected frequencies. With the design procedure being generically applicable to wave scattering in single-channel settings, we demonstrate it with concrete examples of photonic multilayer setups.

Drive piston assembly for a valve actuator assembly

Science.gov (United States)

Sun, Zongxuan

2010-02-23

A drive piston assembly is provided that is operable to selectively open a poppet valve. The drive piston assembly includes a cartridge defining a generally stepped bore. A drive piston is movable within the generally stepped bore and a boost sleeve is coaxially disposed with respect to the drive piston. A main fluid chamber is at least partially defined by the generally stepped bore, drive piston, and boost sleeve. First and second feedback chambers are at least partially defined by the drive piston and each are disposed at opposite ends of the drive piston. At least one of the drive piston and the boost sleeve is sufficiently configured to move within the generally stepped bore in response to fluid pressure within the main fluid chamber to selectively open the poppet valve. A valve actuator assembly and engine are also provided incorporating the disclosed drive piston assembly.

Configurable double-sided modular jet impingement assemblies for electronics cooling

Science.gov (United States)

Zhou, Feng; Dede, Ercan Mehmet

2018-05-22

A modular jet impingement assembly includes an inlet tube fluidly coupled to a fluid inlet, an outlet tube fluidly coupled to a fluid outlet, and a modular manifold having a first distribution recess extending into a first side of the modular manifold, a second distribution recess extending into a second side of the modular manifold, a plurality of inlet connection tubes positioned at an inlet end of the modular manifold, and a plurality of outlet connection tubes positioned at an outlet end of the modular manifold. A first manifold insert is removably positioned within the first distribution recess, a second manifold insert is removably positioned within the second distribution recess, and a first and second heat transfer plate each removably coupled to the modular manifold. The first and second heat transfer plates each comprise an impingement surface.

Beta-carotene to bacteriochlorophyll-c energy transfer in self-assembled aggregates mimicking chlorosomes

Czech Academy of Sciences Publication Activity Database

Alster, J.; Polívka, Tomáš; Arellano, J.B.; Chábera, P.; Vácha, František; Pšenčík, J.

2010-01-01

Roč. 373, 1-2 (2010), s. 90-97 ISSN 0301-0104 R&D Projects: GA ČR GA206/09/0375 Institutional research plan: CEZ:AV0Z50510513 Keywords : carotenoids * chlorosomes * energy transfer Subject RIV: BO - Biophysics Impact factor: 2.017, year: 2010

Direct effects of ionizing radiation on integral membrane proteins. Noncovalent energy transfer requires specific interpeptide interactions

International Nuclear Information System (INIS)

Jhun, E.; Jhun, B.H.; Jones, L.R.; Jung, C.Y.

1991-01-01

The 12 transmembrane alpha helices (TMHs) of human erythrocyte glucose transporter were individually cut by pepsin digestion as membrane-bound 2.5-3.5-kDa peptide fragments. Radiation-induced chemical degradation of these fragments showed an average target size of 34 kDa. This is 10-12 x larger than the average size of an individual TMH, demonstrating that a significant energy transfer occurs among these TMHs in the absence of covalent linkage. Heating this TMH preparation at 100 degree C for 15 min reduced the target size to 5 kDa or less, suggesting that the noncovalent energy transfer requires specific helix-helix interactions. Purified phospholamban, a small (6-kDa) integral membrane protein containing a single TMH, formed a pentameric assembly in sodium dodecyl sulfate. The chemical degradation target size of this phospholamban pentamer was 5-6 kDa, illustrating that not all integral membrane protein assemblies permit intersubunit energy transfer. These findings together with other published observations suggest strongly that significant noncovalent energy transfer can occur within the tertiary and quaternary structure of membrane proteins and that as yet undefined proper molecular interactions are required for such covalent energy transfer. Our results with pepsin-digested glucose transporter also illustrate the importance of the interhelical interaction as a predominating force in maintaining the tertiary structure of a transmembrane protein

Layer-by-layer strippable Ag multilayer films fabricated by modular assembly.

Science.gov (United States)

Li, Yan; Chen, Xiaoyan; Li, Qianqian; Song, Kai; Wang, Shihui; Chen, Xiaoyan; Zhang, Kai; Fu, Yu; Jiao, Yong-Hua; Sun, Ting; Liu, Fu-Chun; Han, En-Hou

2014-01-21

We have developed a new method to fabricate multilayer films, which uses prepared thin films as modular blocks and transfer as operation mode to build up multilayer structures. In order to distinguish it from the in situ fabrication manner, this method is called modular assembly in this study. On the basis of such concept, we have fabricated a multilayer film using the silver mirror film as the modular block and poly(lactic acid) as the transfer tool. Due to the special double-layer structure of the silver mirror film, the resulting multilayer film had a well-defined stratified architecture with alternate porous/compact layers. As a consequence of the distinct structure, the interaction between the adjacent layers was so weak that the multilayer film could be layer-by-layer stripped. In addition, the top layer in the film could provide an effective protection on the morphology and surface property of the underlying layers. This suggests that if the surface of the film was deteriorated, the top layer could be peeled off and the freshly exposed surface would still maintain the original function. The successful preparation of the layer-by-layer strippable silver multilayer demonstrates that modular assembly is a feasible and effective method to build up multilayer films capable of creating novel and attractive micro/nanostructures, having great potential in the fabrication of nanodevices and coatings.

Assembly and loss of the polar flagellum in plant-associated methylobacteria

Science.gov (United States)

Doerges, L.; Kutschera, U.

2014-04-01

On the leaf surfaces of numerous plant species, inclusive of sunflower ( Helianthus annuus L.), pink-pigmented, methanol-consuming, phytohormone-secreting prokaryotes of the genus Methylobacterium have been detected. However, neither the roles, nor the exact mode of colonization of these epiphytic microbes have been explored in detail. Using germ-free sunflower seeds, we document that, during the first days of seedling development, methylobacteria exert no promotive effect on organ growth. Since the microbes are evenly distributed over the outer surface of the above-ground phytosphere, we analyzed the behavior of populations taken from two bacterial strains that were cultivated as solid, biofilm-like clones on agar plates in different aqueous environments ( Methylobacterium mesophilicum and M. marchantiae, respectively). After transfer into liquid medium, the rod-shaped, immobile methylobacteria assembled a flagellum and developed into planktonic microbes that were motile. During the linear phase of microbial growth in liquid cultures, the percentage of swimming, flagellated bacteria reached a maximum, and thereafter declined. In stationary populations, living, immotile bacteria, and isolated flagella were observed. Hence, methylobacteria that live in a biofilm, transferred into aqueous environments, assemble a flagellum that is lost when cell density has reached a maximum. This swimming motility, which appeared during ontogenetic development within growing microbial populations, may be a means to colonize the moist outer surfaces of leaves.

Analysis of a spacecraft instrument ball bearing assembly lubricated by a perfluoroalkylether

Science.gov (United States)

Morales, W.; Jones, W. R., Jr.; Buckley, D. H.

1986-01-01

An analysis of a spacecraft instrument ball bearing assembly, subjected to a scanning life test, was performed to determine the possible case of rotational problems involving these units aboard several satellites. The analysis indicated an ineffective transfer of a fluorinated liquid lubricant from a phenolic retainer to the bearing balls. Part of the analysis led to a novel HPLC separation method employing a fluorinated mobile phase in conjunction with silica based size exclusion columns.

Identification and evaluation of modularization practices in an automotive supplier: progressivity analysis of transferring activities in the supply chain

Directory of Open Access Journals (Sweden)

Evandro Prieto

2013-08-01

Full Text Available The automotive value chain has more and more been making room to a strategy of which activities of product design and production have been transferred to the module suppliers. The transfer of value-added activities occurs from assembler to the module suppliers. The former assume the role of integrators within the supply chain. The supply chain participants have started to strengths their competencies in order to obtain advantages in the economy of scale and scope. In this context, the present work aims at investigating the valued-added transfer between first and second tiers of automotive supply chain in new product development and production. The work was carried out from an evaluation of a supplier with regard to modularization. The theoretical background considers the concepts of integrated and modular architecture as well as the progressiveness of competencies among suppliers. It adopts single cased as the research methodological approach. The literature points out that the process of modularization either in product development or in production offer benefits for both sides: assemblers and suppliers. The results from the investigated supplier shows inherent benefits due to the acquisition of new technologies that enable an increase of technical and management learning in projects of new products. Therefore, it demonstrates that in this modularity environment, the potential of value-added transfer is associated to the level of progressiveness of competencies that are incorporated to deliver module solutions to assemblers; the investigated supplier can be categorized in an “embrionary” stage.

Self-assembled nanostructures

CERN Document Server

Zhang, Jin Z; Liu, Jun; Chen, Shaowei; Liu, Gang-yu

2003-01-01

Nanostructures refer to materials that have relevant dimensions on the nanometer length scales and reside in the mesoscopic regime between isolated atoms and molecules in bulk matter. These materials have unique physical properties that are distinctly different from bulk materials. Self-Assembled Nanostructures provides systematic coverage of basic nanomaterials science including materials assembly and synthesis, characterization, and application. Suitable for both beginners and experts, it balances the chemistry aspects of nanomaterials with physical principles. It also highlights nanomaterial-based architectures including assembled or self-assembled systems. Filled with in-depth discussion of important applications of nano-architectures as well as potential applications ranging from physical to chemical and biological systems, Self-Assembled Nanostructures is the essential reference or text for scientists involved with nanostructures.

Experimental heat transfer in tube bundle

International Nuclear Information System (INIS)

Khattab, M.; Mariy, A.; Habib, M.

1983-01-01

Previous work has looked for the problem of heat transfer with flow parallel to rod bundle either by treating each rod individually as a separate channel or by treating the bundle as one unit. The present work will consider the existence of both the central and corner rods simultaneously inside the cluster itself under the same working conditions. The test section is geometrically similar to the fuel assembly of the Egyptian Research Reactor-1. The hydro-thermal performance of bundle having 16 - stainless steel tubes arranged in square array of 1.5 pitch to diameter ratio is investigated. Surface temperature and pressure distributions are determined. Average heat transfer coefficient for both central and corner tubes are correlated. Also, pressure drop and friction factor correlations are predicted. The maximum experimental range of the measured parameters are determined in the nonboiling region at 1400 Reynolds number and 3.64 W/cm 2 . It is found that the average heat transfer coefficient of the central tube is higher than that of the corner tube by 27%. Comparison with the previous work shows satisfactory agreement particularly with the circular tubes correlation - Dittus et al. - at 104 Reynolds number

Layer-by-layer assembled multilayers using catalase-encapsulated gold nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Kim, Sungwoo; Park, Jeongju [School of Advanced Materials Engineering, Kookmin University, Jeongneung-dong, Seongbuk-gu, Seoul 136-702 (Korea, Republic of); Cho, Jinhan, E-mail: jinhan71@korea.ac.kr [Department of Chemical and Biological Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-701 (Korea, Republic of)

2010-09-17

We introduce a novel and versatile approach for the preparation of multilayers, based on catalase-encapsulated gold nanoparticles (CAT-Au{sub NP}), allowing electrostatic charge reversal and structural transformation through pH adjustment. CAT-Au{sub NP}, which are synthesized directly from CAT stabilizer, can be electrostatically assembled with anionic and cationic PEs as a result of the charge reversal of the catalase stabilizers through pH control. In particular, at pH 5.2, near the pI of catalase, dispersed CAT-Au{sub NP} are structurally transformed into colloidal or network CAT-Au{sub NP} nanocomposites. Furthermore, we demonstrate that the layer-by-layer assembled multilayers composed of PEs and CAT-Au{sub NP} induce an effective electron transfer between CAT and the electrode as well as a high loading of CAT and Au{sub NP}, and resultantly exhibit a highly catalytic activity toward H{sub 2}O{sub 2}.

Emergency transfer tube closure and process for sealing transfer tube under emergency conditions

International Nuclear Information System (INIS)

Hardin, R.T. Jr.; Marshall, J.R.

1987-01-01

In a nuclear fuel reactor well that includes a transfer tube projecting outwardly from wall thereof, the transfer tube is described having a first closure assembly. The transfer tube has a circumferential flange extending outwardly laterally therefrom, an emergency transfer tube closure therefor comprising; a pair of elongated, vertically-extending U-shaped guides, one U-shaped guide disposed laterally on each side of the transfer tube, each of the U-shaped guides comprising a base and laterally extending flanges thereon, the U-shaped guides having their open ends facing each other, a closure plate, having a surface facing the circumferential flange greater in area than the area circumscribed by the outer circumference of the circumferential flange, vertically disposed the U-shaped guides, the closure plate normally being disposed in a vertical plane just slightly in front of the vertical plane of the circumferential flange, two pairs of rollers, one pair of which is rotatably mounted on each side of the closure plate adjacent the U-shaped guides, riding on the inner portion of each of the flanges of each of the U-shaped guides. Each of the U-shaped guides is provided with a pair of spatially disposed openings on a flange thereof adjacent the wall of the nuclear fuel reactor well, each of the pairs of openings being disposed on each of the U-shaped guides a distance equal to the distance between the center lines of the corresponding pair of rollers riding within the U-shaped guides, each of the openings being sufficiently large to receive a corresponding roller of the pairs of rollers in the U-shaped guides. The openings is shaped on the flanges of the U-shaped guides so that when the pairs of rollers are disposed therein, the face of the closure plate will be in sealing engagement with the circumferential flange of the transfer tube

A thermal-hydraulic test rig for advanced fast reactor fuel assemblies

International Nuclear Information System (INIS)

Rapier, A.C.

1989-03-01

A new design of fast reactor fuel assemblies has been proposed in which the pins are supported in grids attached to the wrapper by flexible skirts. Coolant mixing is enhanced by the skirts diverting flow into the cluster of pins at each grid. There are insufficient empirical data available for the detailed design of the skirt or for the input to computer calculations of flow and heat transfer. A test rig to provide these data has been designed and built. (author)

Sandwiched confinement of quantum dots in graphene matrix for efficient electron transfer and photocurrent production

DEFF Research Database (Denmark)

Zhu, Nan; Zheng, Kaibo; J. Karki, Khadga

2015-01-01

matrix via interfacial self-assembly, leading to the formation of sandwiched hybrid QD-graphene nanofilms. We have explored structural features, electron transfer kinetics and photocurrent generation capacity of such hybrid nanofilms using a wide variety of advanced techniques. Graphene nanosheets...

An Analysis on the Moisture and Thermal Protective Performance of Firefighter Clothing Based on Different Layer Combinations and Effect of Washing on Heat Protection and Vapour Transfer Performance

Directory of Open Access Journals (Sweden)

Ozgur Atalay

2015-01-01

Full Text Available Fabric assemblies for firefighting clothing have been tested for heat protection and comfort. The constituent materials and fabric structures have been specifically selected and tailored for firefighters’ clothing. In order to do this, four types of outer shell fabrics, four types of moisture barrier fabrics, and four types of heat barriers with different weights and material compositions were used to make a multilayered fabric assembly. Heat transfer (flame, heat transfer (radiant, and water vapour resistance tests were conducted according to the latest EN469 test standard which also recommends washing tests. These tests reveal that material content and material brand have considerable effect on the required performance levels of heat protection. In addition, while washing tests have improved water vapor transfer properties, they have a deteriorating effect on heat protection performance. Considering heat protection and moisture comfort properties, the optimal assemblies are thereby identified.

Direct electrochemistry of glucose oxidase assembled on graphene and application to glucose detection

International Nuclear Information System (INIS)

Wu Ping; Shao Qian; Hu Yaojuan; Jin Juan; Yin Yajing; Zhang Hui; Cai Chenxin

2010-01-01

The direct electrochemistry of glucose oxidase (GOx) integrated with graphene was investigated. The voltammetric results indicated that GOx assembled on graphene retained its native structure and bioactivity, exhibited a surface-confined process, and underwent effective direct electron transfer (DET) reaction with an apparent rate constant (k s ) of 2.68 s -1 . This work also developed a novel approach for glucose detection based on the electrocatalytic reduction of oxygen at the GOx-graphene/GC electrode. The assembled GOx could electrocatalyze the reduction of dissolved oxygen. Upon the addition of glucose, the reduction current decreased, which could be used for glucose detection with a high sensitivity (ca. 110 ± 3 μA mM -1 cm -2 ), a wide linear range (0.1-10 mM), and a low detection limit (10 ± 2 μM). The developed approach can efficiently exclude the interference of commonly coexisting electroactive species due to the use of a low detection potential (-470 mV, versus SCE). Therefore, this study has not only successfully achieved DET reaction of GOx assembled on graphene, but also established a novel approach for glucose detection and provided a general route for fabricating graphene-based biosensing platform via assembling enzymes/proteins on graphene surface.

Assembly of the Boechera retrofracta Genome and Evolutionary Analysis of Apomixis-Associated Genes

Directory of Open Access Journals (Sweden)

Sergei Kliver

2018-03-01

Full Text Available Closely related to the model plant Arabidopsis thaliana, the genus Boechera is known to contain both sexual and apomictic species or accessions. Boechera retrofracta is a diploid sexually reproducing species and is thought to be an ancestral parent species of apomictic species. Here we report the de novo assembly of the B. retrofracta genome using short Illumina and Roche reads from 1 paired-end and 3 mate pair libraries. The distribution of 23-mers from the paired end library has indicated a low level of heterozygosity and the presence of detectable duplications and triplications. The genome size was estimated to be equal 227 Mb. N50 of the assembled scaffolds was 2.3 Mb. Using a hybrid approach that combines homology-based and de novo methods 27,048 protein-coding genes were predicted. Also repeats, transfer RNA (tRNA and ribosomal RNA (rRNA genes were annotated. Finally, genes of B. retrofracta and 6 other Brassicaceae species were used for phylogenetic tree reconstruction. In addition, we explored the histidine exonuclease APOLLO locus, related to apomixis in Boechera, and proposed model of its evolution through the series of duplications. An assembled genome of B. retrofracta will help in the challenging assembly of the highly heterozygous genomes of hybrid apomictic species.

Newnes electronics assembly handbook

CERN Document Server

Brindley, Keith

2013-01-01

Newnes Electronics Assembly Handbook: Techniques, Standards and Quality Assurance focuses on the aspects of electronic assembling. The handbook first looks at the printed circuit board (PCB). Base materials, basic mechanical properties, cleaning of assemblies, design, and PCB manufacturing processes are then explained. The text also discusses surface mounted assemblies and packaging of electromechanical assemblies, as well as the soldering process. Requirements for the soldering process; solderability and protective coatings; cleaning of PCBs; and mass solder/component reflow soldering are des

Temperature rise of the mask-resist assembly during LIGA exposure

International Nuclear Information System (INIS)

Ting, Aili

2004-01-01

Deep X-ray lithography on PMMA resist is used in the LIGA process. The resist is exposed to synchrotron X-rays through a patterned mask and then is developed in a liquid developer to make high aspect ratio microstructures. The limitations in dimensional accuracies of the LIGA generated microstructure originate from many sources, including synchrotron and X-ray physics, thermal and mechanical properties of mask and resist, and from the kinetics of the developer. This work addresses the thermal analysis and temperature rise of the mask-resist assembly during exposure in air at the Advanced Light Source (ALS) synchrotron. The concern is that dimensional errors generated at the mask and the resist due to thermal expansion will lower the accuracy of the lithography. We have developed a three-dimensional finite-element model of the mask and resist assembly that includes a mask with absorber, a resist with substrate, three metal holders, and a water-cooling block. We employed the LIGA exposure-development software LEX-D to calculate volumetric heat sources generated in the assembly by X-ray absorption and the commercial software ABAQUS to calculate heat transfer including thermal conduction inside the assembly, natural and forced convection, and thermal radiation. at assembly outer and/or inner surfaces. The calculations of assembly maximum temperature. have been compared with temperature measurements conducted at ALS. In some of these experiments, additional cooling of the assembly was produced by forced nitrogen flow ('nitrogen jets') directed at the mask surface. The temperature rise in the silicon mask and the mask holder comes directly from the X-ray absorption, but nitrogen jets carry away a significant portion of heat energy from the mask surface, while natural convection carries away negligibly small amounts energy from the holder. The temperature rise in PMMA resist is mainly from heat conducted from the silicon substrate backward to the resist and from the inner

Heat transfer enhancement for spent nuclear fuel assembly disposal packages using metallic void fillers: A prevention technique for solidification shrinkage-induced interfacial gaps

Energy Technology Data Exchange (ETDEWEB)

Park, Yongsoo, E-mail: yspark@alum.mit.edu; McKrell, Thomas J.; Driscoll, Michael J.

2017-06-15

This study considers replacing the externally accessible void spaces inside a disposal package containing a spent nuclear fuel assembly (SNFA) with high heat conducting metal to increase the effective thermal conductivity of the package and simplify the heat transfer mechanism inside the package by reducing it to a conduction dominant problem. The focus of the study is on preventing the gaps adjacent to the walls of the package components, produced by solidification shrinkage of poured liquid metal. We approached the problem by providing a temporary coating layer on the components to avoid direct build-up of thick metal oxides on their surface to promote metallic bonding at the interfaces under a non-inert environment. Laboratory scale experiments without SNFA were performed with Zn coated low carbon steel canisters and Zamak-3 void filler under two different filling temperature conditions – below and above the melting point of Zn (designated BMP and AMP respectively). Gap formation was successfully prevented in both cases while we confirmed an open gap in a control experiment, which used an uncoated canister. Minor growth of Al-Fe intermetallic phases was observed at the canister/filler interface of the sample produced under the BMP condition while their growth was significant and showed irregularly distributed morphology in the sample produced under the AMP condition, which has a potential to mitigate excessive residual stresses caused by shrinkage prevention. A procedure for the full-scale application was specified based on the results. - Highlights: •A void filling technique is introduced to enhance SNFA package heat transfer. •The technique is demonstrated via experiments using the Fe-Al-Zn system. •A procedure for the full scale application is proposed based on the results.

Layer-by-layer self-assembled nanostructured phthalocyaninatoiron(II)/SWCNT-poly(m-aminobenzenesulfonic acid) hybrid system on gold surface: Electron transfer dynamics and amplification of H{sub 2}O{sub 2} response

Energy Technology Data Exchange (ETDEWEB)

Pillay, Jeseelan [Molecular and Nanomaterials Electrochemistry laboratory, Department of Chemistry, University of Pretoria, Pretoria 0002 (South Africa); Ozoemena, Kenneth I. [Molecular and Nanomaterials Electrochemistry laboratory, Department of Chemistry, University of Pretoria, Pretoria 0002 (South Africa)], E-mail: kenneth.ozoemena@up.ac.za

2009-09-01

The fabrication of nanostructured platform of poly(m-aminobenzenesulfonic acid) functionalised single-walled carbon nanotubes (SWCNTs-PABS)-iron(II)phthalocyanine nanoparticles (nanoFePc) using layer-by-layer(LBL) self-assembly strategy is described. The substrate build-up, via strong electrostatic interaction, was monitored using atomic force microscopy (AFM) and electrochemical measurements. As the number of bilayers is increased, the electron transfer kinetics of the ferricyaninde/ferrocyanide redox probe is decreased, while the electrochemical reduction of H{sub 2}O{sub 2} at a constant concentration is amplified. The amplification of the electrochemical response to H{sub 2}O{sub 2} detection suggests that this type of electrode could provide an important nano-architectural sensing platform for the development of a sensor.

Fuel Assembly Damping Summary

Energy Technology Data Exchange (ETDEWEB)

Lee, Kanghee; Kang, Heungseok; Oh, Dongseok; Yoon, Kyungho; Kim, Hyungkyu; Kim, Jaeyong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-10-15

This paper summary the fuel assembly damping data in air/in still water/under flow, released from foreign fuel vendors, compared our data with the published data. Some technical issues in fuel assembly damping measurement testing are also briefly discussed. Understanding of each fuel assembly damping mechanisms according to the surrounding medium and flow velocity can support the fuel design improvement in fuel assembly dynamics and structural integrity aspect. Because the upgraded requirements of the newly-developed advanced reactor system will demands to minimize fuel design margin in integrity evaluation, reduction in conservatism of fuel assembly damping can contribute to alleviate the fuel design margin for sure. Damping is an energy dissipation mechanism in a vibrating mechanical structure and prevents a resonant structure from having infinite vibration amplitudes. The sources of fuel assembly damping are various from support friction to flow contribution, and it can be increased by the viscosity or drag of surrounding fluid medium or the average velocity of water flowing. Fuel licensing requires fuel design evaluation in transient or accidental condition. Dynamic response analysis of fuel assembly is to show fuel integrity and requires information on assembly-wise damping in dry condition and under wet or water flowing condition. However, damping measurement test for the full-scale fuel assembly prototype is not easy to carry out because of the scale (fuel prototype, test facility), unsteadiness of test data (scattering, random sampling and processing), instrumentation under water flowing (water-proof response measurement), and noise. LWR fuel technology division in KAERI is preparing the infra structure for damping measurement test of full-scale fuel assembly, to support fuel industries and related research activities. Here is a preliminary summary of fuel assembly damping, published in the literature. Some technical issues in fuel assembly damping

RAGRAF: a computer code for calculating temperature distributions in multi-pin fuel assemblies in a stagnant gas atmosphere

International Nuclear Information System (INIS)

Eastham, A.

1979-02-01

A method of calculating the temperature distribution in a cross-section of a multi-pin nuclear reactor fuel assembly has been computerised. It utilises the thermal radiation interchange between individual fuel pins in either a square or triangular pitched lattice. A stagnant gas atmosphere within the fuel assembly is assumed which inhibits natural convection but permits thermal conduction between adjacent fuel pins. no restriction is placed upon the shape of wrapper used, but its temperature must always be uniform. RAGRAF has great flexibility because of the many options it provides. Although, essentially, it is a transient code, steady state solutions may be readily identified from successive temperature prints. An enclosure for the assembly wrapper is available, to be included or discarded at will during transient calculations. outside the limit of the assembly wrapper, any type or combination of heat transfer mode may be included. Transient variations in boundary temperature may be included if required. (author)

Fuel assembly

International Nuclear Information System (INIS)

Abe, Hideaki; Sakai, Takao; Ishida, Tomio; Yokota, Norikatsu.

1992-01-01

The lower ends of a plurality of plate-like shape memory alloys are secured at the periphery of the upper inside of the handling head of a fuel assembly. As the shape memory alloy, a Cu-Zn alloy, a Ti-Pd alloy or a Fe-Ni alloy is used. When high temperature coolants flow out to the handling head, the shape memory alloy deforms by warping to the outer side more greatly toward the upper portion thereof with the temperature increase of the coolants. As the result, the shape of the flow channel of the coolants is changed so as to enlarge at the exit of the upper end of the fuel assembly. Then, the pressure loss of the coolants in the fuel assembly is decreased by the enlargement. Accordingly, the flow rate of the coolants in the fuel assembly is increased to lower the temperature of the coolants. Further, high temperature coolants and low temperature coolants are mixed sufficiently just above the fuel assembly. This can suppress the temperature fluctuation of the mixed coolants in the upper portion of the reactor core, thereby enabling to decrease a fatigue and failures of the structural components in the upper portion of the reactor core. (I.N.)

Preparation and self-assembly behavior of polystyrene-block-poly (dimethylaminoethyl methacrylate amphiphilic block copolymer using atom transfer radical polymerization

Directory of Open Access Journals (Sweden)

2008-03-01

Full Text Available Asymmetric and semi-symmetric amphiphilic diblock copolymers polystyrene-block-poly (dimethylaminoethyl methacrylate (PS-b-PDMAEMA with the same PS block length of 62 repeat units and quite short (3 repeat units or equivalent (47 repeat units length of PDMAEMA have been prepared simply by varying the ratio of the bromine-terminated macroinitiator polystyrene (PS-Br to DMAEMA using atom transfer radical polymerization (ATRP. The chemical structures and compositions of the PS-b-PDMAEMA block copolymers are studied by nuclear magnetic resonance (NMR spectroscopy, gel permeation chromatography (GPC, and elementary analysis (EA. The self-assembly behaviors of copolymers in N,N-dimethyl formamide (DMF with different pH and dioxane/water binary solvent mixture by direct dissolution method (DD, are studied by transmission electron microscopy (TEM, electron diffracting analysis (EDA, and energy-dispersive analysis of X-rays (EDAX techniques. Transmission electron microscopy results suggest that asymmetric block copolymer PS62-b-PDMAEMA3 (the numbers in the form of footnotes represent repeated units of each monomer in the copolymer can form spherical core-shell micelles, large compound reverse micelles (LCRMs, hexagonal/rhombic phases, reverse hexagonal/rhombic phases, vesicles, reverse vesicles and necklace-like reverse micelles, controlled by common or selective solvent and pH, while most of the aggregates of semi-symmetric PS62-b-PDMAEMA47 are simply spherical, such as spherical core-shell micelles and reverse spherical core-shell micelles, besides hexagonal/rhombic phases. All above structures are controlled by three components of the free energy of aggregation: core-chain stretching, interfacial energy and intercoronal chain interaction.

Soldering in electronics assembly

CERN Document Server

Judd, Mike

2013-01-01

Soldering in Electronics Assembly discusses several concerns in soldering of electronic assemblies. The book is comprised of nine chapters that tackle different areas in electronic assembly soldering. Chapter 1 discusses the soldering process itself, while Chapter 2 covers the electronic assemblies. Chapter 3 talks about solders and Chapter 4 deals with flux. The text also tackles the CS and SC soldering process. The cleaning of soldered assemblies, solder quality, and standards and specifications are also discussed. The book will be of great use to professionals who deal with electronic assem

The problems of calculation of heat transfer crisis in fuel assemblies of PW reactors based on modern versions of thermohydraulic codes

International Nuclear Information System (INIS)

Fialko, N.M.; Sharaevskij, G.I.; Sharaevskaya, E.I.; Babak, E.I.

2014-01-01

The article gives an analysis of the adequacy of computer software systems FASCICLE BM-DF and COBRA, which are designed to calculate the main parameters of the safety of water-cooled nuclear reactors. This calculation is based on determining the local thermal-hydraulic parameters of the flow of coolant in the fuel rod assembled elements. In this article introduced the results of the comparison of experiments performed to determine the distribution of the main thermal-hydraulic flow parameters characteristic of subchannels of fuel rod assembled elements with the data for calculating these parameters on the basis of declared computer codes. Particular attention is paid to the analysis of experimental and calculation data, by definition, burnout in rod fuel assembled elements

Multivalent protein assembly using monovalent self-assembling building blocks

NARCIS (Netherlands)

Petkau - Milroy, K.; Sonntag, M.H.; Colditz, A.; Brunsveld, L.

2013-01-01

Discotic molecules, which self-assemble in water into columnar supramolecular polymers, emerged as an alternative platform for the organization of proteins. Here, a monovalent discotic decorated with one single biotin was synthesized to study the self-assembling multivalency of this system in regard

Final Scientific Report - Electromagnetic Interactions in Self-Assembled Metallo-Dielectric Biomaterials

Energy Technology Data Exchange (ETDEWEB)

Dragnea, Bogdan G. [Indiana Univ., Bloomington, IN (United States)

2017-05-03

Achievements which resulted from previous DOE funding include: templated virus-like particle assembly thermodynamics, development of single particle photothermal absorption spectroscopy and dark- field spectroscopy instrumentation for the measurement of optical properties of virus-like nanoparticles, electromagnetic simulations of coupled nanoparticle cluster systems, virus contact mechanics, energy transfer and fluorescence quenching in multichromophore systems supported on biomolecular templates, and photo physical work on virus-aptamer systems. A current total of eight published research articles and a book chapter are acknowledging DOE support for the period 2013-2016.

In situ studies of nucleation and assembly at soft-hard interfaces

Energy Technology Data Exchange (ETDEWEB)

Dutta, Pulak [Northwestern Univ., Evanston, IL (United States)

2013-04-01

The overall goal of this project was the exploration of new ways to make organic and hybrid (organic-inorganic) materials for energy-related applications. Towards this end, our research focused on the structure and behavior of molecular monolayers at interfaces (including floating monolayers, transferred Langmuir-Blodgett monolayers, and self-assembled monolayers), as well as the biomimetic nucleation of inorganic crystals at soft-hard interfaces. The project resulted in a number of 'firsts' and other notable achievements, which are described in the report.

Experience from transportation of irradiated WWER-440 fuel assemblies at Kozloduy NPP site after a short cooling time

International Nuclear Information System (INIS)

Stoyanova, I.; Kamenov, A.; Byrzev, L.; Christoskov, I.

2003-01-01

The presented results from the computation and analysis of the radiation characteristics of the irradiated fuel assemblies by the date of their transportation according to the selected loading patterns of the VSPOT cask and following the modified technology of transportation, i.e. without replacement of the pool solution by pure condensate, as well as the corresponding experimental results, confirm the applicability of the newly introduced safety criterion for the selection of a loading pattern of the cask with irradiated fuel assemblies after a short cooling time. The comparison between measured and computed surface dose rates shows that during the procedure of transfer of irradiated fuel assemblies from the pools of Units 1 and 2 to the pools of Kozloduy NPP Units 3 and 4 all safety limits, incl. the radiation protection requirements, were met

Fuel assembly

International Nuclear Information System (INIS)

Gjertsen, R.K.; Bassler, E.A.; Huckestein, E.A.; Salton, R.B.; Tower, S.N.

1988-01-01

A fuel assembly adapted for use with a pressurized water nuclear reactor having capabilities for fluid moderator spectral shift control is described comprising: parallel arranged elongated nuclear fuel elements; means for providing for axial support of the fuel elements and for arranging the fuel elements in a spaced array; thimbles interspersed among the fuel elements adapted for insertion of a rod control cluster therewithin; means for structurally joining the fuel elements and the guide thimbles; fluid moderator control means for providing a volume of low neutron absorbing fluid within the fuel assembly and for removing a substantially equivalent volume of reactor coolant water therefrom, a first flow manifold at one end of the fuel assembly sealingly connected to a first end of the moderator control tubes whereby the first ends are commonly flow connected; and a second flow manifold, having an inlet passage and an outlet passage therein, sealingly connected to a second end of the moderator control tubes at a second end of the fuel assembly

Self assembly of organic nanostructures and dielectrophoretic assembly of inorganic nanowires.

Science.gov (United States)

Dholakia, Geetha; Kuo, Steven; Allen, E. L.

2007-03-01

Self assembly techniques enable the organization of organic molecules into nanostructures. Currently engineering strategies for efficient assembly and routine integration of inorganic nanoscale objects into functional devices is very limited. AC Dielectrophoresis is an efficient technique to manipulate inorganic nanomaterials into higher dimensional structures. We used an alumina template based sol-gel synthesis method for the growth of various metal oxide nanowires with typical diameters of 100-150 nm, ranging in length from 3-10 μm. Here we report the dielectrophoretic assembly of TiO2 nanowires, an important material for photocatalysis and photovoltaics, onto interdigitated devices. Self assembly in organic nanostructures and its dependence on structure and stereochemistry of the molecule and dielectrophoretic field dependence in the assembly of inorganic nanowires will be compared and contrasted. Tunneling spectroscopy and DOS of these nanoscale systems will also be discussed.

Doses of the staff during the spent fuel assemblies transportation and storage in Nuhmos 56V concrete system

International Nuclear Information System (INIS)

Atoyan, V.; Muradyan, A.

2003-01-01

The NUHMOS 56V concrete system provides long-term interim storage (50 years) for spent fuel assemblies, which have been out of the reactor for a sufficient period of time. It consists from horizontal storage modules. The fuel assemblies are confined in a helium atmosphere by a canister containment pressure vessel. The canister is protected and shielded by a massive reinforced concrete module. Decay heat is removed from the canister and concrete module by a passive natural draft convection ventilation system. The project of storage does not foresee the radiation monitoring inside of building and around it. But we provided and realize the radiation monitoring program around storage, it includes tree phases: - determination the zero background around the building before storage put in exploiting; - monitoring of the radioactive particles in air (additional aspiration plant); dose rate monitoring by portable dosimeters and soil monitoring during the process of the fuel storage; - constantly after the completion the fuel storage process - monitoring of the radioactive particles in air (additional aspiration plant); dose rate monitoring by portable dosimeters, and soil monitoring. Also designed the dose rate monitoring by the dosimeter RME 3 with the transfer of data by radio channel to central monitor. The canistered spent fuel assemblies are transferred from the plant's spent fuel pool to the concrete storage modules in a transfer cask. The cask is aligned with the storage module and the canister and inserted into the module by means of a hydraulic ram. The system is a totally passive installation that is designed to provide shielding and safe confinement of spent fuel for a range of postulated accident conditions and natural phenomena. (authors)

Fire resistant PV shingle assembly

Science.gov (United States)

Lenox, Carl J.

2012-10-02

A fire resistant PV shingle assembly includes a PV assembly, including PV body, a fire shield and a connection member connecting the fire shield below the PV body, and a support and inter-engagement assembly. The support and inter-engagement assembly is mounted to the PV assembly and comprises a vertical support element, supporting the PV assembly above a support surface, an upper interlock element, positioned towards the upper PV edge, and a lower interlock element, positioned towards the lower PV edge. The upper interlock element of one PV shingle assembly is inter-engageable with the lower interlock element of an adjacent PV shingle assembly. In some embodiments the PV shingle assembly may comprise a ventilation path below the PV body. The PV body may be slidably mounted to the connection member to facilitate removal of the PV body.

Transportation of 33 irradiated MTR fuel assemblies from FRM/Garching to Savannah River Site, USA, using a GNS transport cask and using a new loading device

International Nuclear Information System (INIS)

Dreesen, K.; Goetze, H.G.; Holst, L.; Gerstenberg, H.; Schreckenbach, K.

2000-01-01

According to the Department of Energy program of the return spent fuel from the foreign research reactors operators, 33 irradiated MTR box shaped fuel assemblies from the Technical University Munich were shipped to SRS/USA. The fuel assemblies were irradiated for typically 800 full days and, after a sufficient cooling time, loaded into a GNS 16 cask. The GNS 16 cask is a new transport cask for box shaped MTR fuel assemblies and TRIGA fuel assemblies and was used for the first time at the FRM Garching. The capacity of the cask is 33 box shaped MTR fuel assemblies. During the loading of the fuel assemblies, a newly developed loading device was used. The main components of the loading device are the transfer flask, the shielded loading lock, adapter plate and a mobile water tank. The loading device works mechanically with manpower. For the handling of the transfer flask, a crane with a capacity of 5 metric tons is necessary. During installation of the lid the mobile water pool is filled with demineralized water and the shielded loading passage is taken away. After that the lid is put on the cask. After drainage, the mobile water pool is disassembled, and the cask is dewatered. Finally leak tests of all seals are made. The achieved leakage rate was -5 Pa x I/s. The work in FRM was done between 03.02.99 and 12.02.99 including a dry run and leak test. (author)

Steady and Transient Analysis of Flow and Heat Transfer in SPND Assembly

OpenAIRE

Tijiboy, Jose Carlos

2008-01-01

This thesis presents the analysis of flow and heat transfer for the SPND (Self-Powered Neutron Detector) system used within the nuclear reactor core in the U.S. Evolutionary Power Reactor developed by AREVA. The SPND system is composed of six individual detectors which are used for in-core measurement of thermal neutron flux. The study of the SPND system is important since this system provides information and signals necessary for safe reactor operation and control. The main goal of the proj...

Computational study of energy transfer in two-dimensional J-aggregates

International Nuclear Information System (INIS)

Gallos, Lazaros K.; Argyrakis, Panos; Lobanov, A.; Vitukhnovsky, A.

2004-01-01

We perform a computational analysis of the intra- and interband energy transfer in two-dimensional J-aggregates. Each aggregate is represented as a two-dimensional array (LB-film or self-assembled film) of two kinds of cyanine dyes. We consider the J-aggregate whose J-band is located at a shorter wavelength to be a donor and an aggregate or a small impurity with longer wavelength to be an acceptor. Light absorption in the blue wing of the donor aggregate gives rise to the population of its excitonic states. The depopulation of these states is possible by (a) radiative transfer to the ground state (b) intraband energy transfer, and (c) interband energy transfer to the acceptor. We study the dependence of energy transfer on properties such as the energy gap, the diagonal disorder, and the exciton-phonon interaction strength. Experimentally observable parameters, such as the position and form of luminescence spectrum, and results of the kinetic spectroscopy measurements strongly depend upon the density of states in excitonic bands, rates of energy exchange between states and oscillator strengths for luminescent transitions originating from these states

Visualization of Stereoselective Supramolecular Polymers by Chirality-Controlled Energy Transfer.

Science.gov (United States)

Sarkar, Aritra; Dhiman, Shikha; Chalishazar, Aditya; George, Subi J

2017-10-23

Chirality-driven self-sorting is envisaged to efficiently control functional properties in supramolecular materials. However, the challenge arises because of a lack of analytical methods to directly monitor the enantioselectivity of the resulting supramolecular assemblies. Presented herein are two fluorescent core-substituted naphthalene-diimide-based donor and acceptor molecules with minimal structural mismatch and they comprise strong self-recognizing chiral motifs to determine the self-sorting process. As a consequence, stereoselective supramolecular polymerization with an unprecedented chirality control over energy transfer has been achieved. This chirality-controlled energy transfer has been further exploited as an efficient probe to visualize microscopically the chirality driven self-sorting. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ordered macroporous platinum electrode and enhanced mass transfer in fuel cells using inverse opal structure.

Science.gov (United States)

Kim, Ok-Hee; Cho, Yong-Hun; Kang, Soon Hyung; Park, Hee-Young; Kim, Minhyoung; Lim, Ju Wan; Chung, Dong Young; Lee, Myeong Jae; Choe, Heeman; Sung, Yung-Eun

2013-01-01

Three-dimensional, ordered macroporous materials such as inverse opal structures are attractive materials for various applications in electrochemical devices because of the benefits derived from their periodic structures: relatively large surface areas, large voidage, low tortuosity and interconnected macropores. However, a direct application of an inverse opal structure in membrane electrode assemblies has been considered impractical because of the limitations in fabrication routes including an unsuitable substrate. Here we report the demonstration of a single cell that maintains an inverse opal structure entirely within a membrane electrode assembly. Compared with the conventional catalyst slurry, an ink-based assembly, this modified assembly has a robust and integrated configuration of catalyst layers; therefore, the loss of catalyst particles can be minimized. Furthermore, the inverse-opal-structure electrode maintains an effective porosity, an enhanced performance, as well as an improved mass transfer and more effective water management, owing to its morphological advantages.

Complexation-induced supramolecular assembly drives metal-ion extraction.

Science.gov (United States)

Ellis, Ross J; Meridiano, Yannick; Muller, Julie; Berthon, Laurence; Guilbaud, Philippe; Zorz, Nicole; Antonio, Mark R; Demars, Thomas; Zemb, Thomas

2014-09-26

Combining experiment with theory reveals the role of self-assembly and complexation in metal-ion transfer through the water-oil interface. The coordinating metal salt Eu(NO3)3 was extracted from water into oil by a lipophilic neutral amphiphile. Molecular dynamics simulations were coupled to experimental spectroscopic and X-ray scattering techniques to investigate how local coordination interactions between the metal ion and ligands in the organic phase combine with long-range interactions to produce spontaneous changes in the solvent microstructure. Extraction of the Eu(3+)-3(NO3(-)) ion pairs involves incorporation of the "hard" metal complex into the core of "soft" aggregates. This seeds the formation of reverse micelles that draw the water and "free" amphiphile into nanoscale hydrophilic domains. The reverse micelles interact through attractive van der Waals interactions and coalesce into rod-shaped polynuclear Eu(III) -containing aggregates with metal centers bridged by nitrate. These preorganized hydrophilic domains, containing high densities of O-donor ligands and anions, provide improved Eu(III) solvation environments that help drive interfacial transfer, as is reflected by the increasing Eu(III) partitioning ratios (oil/aqueous) despite the organic phase approaching saturation. For the first time, this multiscale approach links metal-ion coordination with nanoscale structure to reveal the free-energy balance that drives the phase transfer of neutral metal salts. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nuclear reactor fuel assembly

International Nuclear Information System (INIS)

Marmonier, Pierre; Mesnage, Bernard; Nervi, J.C.

1975-01-01

This invention refers to fuel assemblies for a liquid metal cooled fast neutron reactor. Each assembly is composed of a hollow vertical casing, of regular polygonal section, containing a bundle of clad pins filled with a fissile or fertile substance. The casing is open at its upper end and has a cylindrical foot at its lower end for positioning the assembly in a housing provided in the horizontal diagrid, on which the core assembly rests. A set of flat bars located on the external surface of the casing enables it to be correctly orientated in its housing among the other core assemblies [fr

Studying electron transfer through alkanethiol self-assembled monolayers on a hanging mercury drop electrode using potentiometric measurements.

Science.gov (United States)

Cohen-Atiya, Meirav; Mandler, Daniel

2006-10-14

A new approach based on measuring the change of the open-circuit potential (OCP) of a hanging mercury drop electrode (HMDE), modified with alkanethiols of different chain length conducted in a solution containing a mixture of Ru(NH3)6(2+) and Ru(NH3)6(3+) is used for studying electron transfer across the monolayer. Following the time dependence of the OCP allowed the extraction of the kinetic parameters, such as the charge transfer resistance (R(ct)) and the electron transfer rate constant (k(et)), for different alkanethiol monolayers. An electron tunneling coefficient, beta, of 0.9 A(-1) was calculated for the monolayers on Hg.

Computational fluid dynamics modeling of two-phase flow in a BWR fuel assembly. Final CRADA Report

International Nuclear Information System (INIS)

Tentner, A.

2009-01-01

A direct numerical simulation capability for two-phase flows with heat transfer in complex geometries can considerably reduce the hardware development cycle, facilitate the optimization and reduce the costs of testing of various industrial facilities, such as nuclear power plants, steam generators, steam condensers, liquid cooling systems, heat exchangers, distillers, and boilers. Specifically, the phenomena occurring in a two-phase coolant flow in a BWR (Boiling Water Reactor) fuel assembly include coolant phase changes and multiple flow regimes which directly influence the coolant interaction with fuel assembly and, ultimately, the reactor performance. Traditionally, the best analysis tools for this purpose of two-phase flow phenomena inside the BWR fuel assembly have been the sub-channel codes. However, the resolution of these codes is too coarse for analyzing the detailed intra-assembly flow patterns, such as flow around a spacer element. Advanced CFD (Computational Fluid Dynamics) codes provide a potential for detailed 3D simulations of coolant flow inside a fuel assembly, including flow around a spacer element using more fundamental physical models of flow regimes and phase interactions than sub-channel codes. Such models can extend the code applicability to a wider range of situations, which is highly important for increasing the efficiency and to prevent accidents.

Cyanide Ligand Assembly by Carbon Atom Transfer to an Iron Nitride

International Nuclear Information System (INIS)

Martinez, Jorge L.; Pink, Maren

2017-01-01

The new iron(IV) nitride complex PhB( i Pr 2 Im) 3 Fe≡N reacts with two equivalents of bis(diisopropylamino)cyclopropenylidene (BAC) to provide PhB( i Pr 2 Im) 3 Fe(CN)(N 2 )(BAC). This unusual example of a four-electron reaction involves carbon atom transfer from BAC to create a cyanide ligand along with the alkyne i Pr 2 N-C≡C-N i Pr 2 . The iron complex is in equilibrium with an N 2 - free species. Further reaction with CO leads to formation of a CO analogue, which can be independently prepared using NaCN as the cyanide source, while reaction with B(C 6 F 5 ) 3 provides the cyanoborane derivative.

Tetratricopeptide repeat protein Pyg7 is essential for photosystem I assembly by interacting with PsaC in Arabidopsis.

Science.gov (United States)

Yang, Huixia; Li, Pin; Zhang, Aihong; Wen, Xiaogang; Zhang, Lixin; Lu, Congming

2017-09-01

Although progress has been made in determining the structure and understanding the function of photosystem I (PSI), the PSI assembly process remains poorly understood. PsaC is an essential subunit of PSI and participates in the transfer of electrons to ferredoxin. However, how PsaC is assembled during accumulation of the PSI complex is unknown. In the present study, we showed that Pyg7 localized to the stromal thylakoid and associated with the PSI complex. We also showed that Pyg7 interacted with PsaC. Furthermore, we found that the PSI assembly process was blocked following formation of the PsaAB heterodimer in the pyg7 mutant. In addition, the analyses of PSI stability in Pyg7RNAi plants showed that Pyg7 is involved in maintaining the assembled PSI complex under excess-light conditions. Moreover, we demonstrated that decreased Pyg7 content resulted in decreased efficiency of PSI assembly in Pyg7RNAi plants. These findings suggest that the role of Pyg7 in PSI biogenesis has evolved as an essential assembly factor by interacting with PsaC in Arabidopsis, in addition to being a stability factor for PSI as seen in Synechocystis. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Integrated Radiation Transport and Nuclear Fuel Performance for Assembly-Level Simulations

Energy Technology Data Exchange (ETDEWEB)

Clarno, Kevin T [ORNL; Hamilton, Steven P [ORNL; Philip, Bobby [ORNL; Berrill, Mark A [ORNL; Sampath, Rahul S [ORNL; Allu, Srikanth [ORNL; Pugmire, Dave [ORNL; Dilts, Gary [Los Alamos National Laboratory (LANL); Banfield, James E [ORNL

2012-02-01

The Advanced Multi-Physics (AMP) Nuclear Fuel Performance code (AMPFuel) is focused on predicting the temperature and strain within a nuclear fuel assembly to evaluate the performance and safety of existing and advanced nuclear fuel bundles within existing and advanced nuclear reactors. AMPFuel was extended to include an integrated nuclear fuel assembly capability for (one-way) coupled radiation transport and nuclear fuel assembly thermo-mechanics. This capability is the initial step toward incorporating an improved predictive nuclear fuel assembly modeling capability to accurately account for source-terms and boundary conditions of traditional (single-pin) nuclear fuel performance simulation, such as the neutron flux distribution, coolant conditions, and assembly mechanical stresses. A novel scheme is introduced for transferring the power distribution from the Scale/Denovo (Denovo) radiation transport code (structured, Cartesian mesh with smeared materials within each cell) to AMPFuel (unstructured, hexagonal mesh with a single material within each cell), allowing the use of a relatively coarse spatial mesh (10 million elements) for the radiation transport and a fine spatial mesh (3.3 billion elements) for thermo-mechanics with very little loss of accuracy. In addition, a new nuclear fuel-specific preconditioner was developed to account for the high aspect ratio of each fuel pin (12 feet axially, but 1 4 inches in diameter) with many individual fuel regions (pellets). With this novel capability, AMPFuel was used to model an entire 17 17 pressurized water reactor fuel assembly with many of the features resolved in three dimensions (for thermo-mechanics and/or neutronics), including the fuel, gap, and cladding of each of the 264 fuel pins; the 25 guide tubes; the top and bottom structural regions; and the upper and lower (neutron) reflector regions. The final, full assembly calculation was executed on Jaguar using 40,000 cores in under 10 hours to model over 162

On the photovoltaic response of the J-domain and the JA-assembly

DEFF Research Database (Denmark)

Krebs, Frederik C

2003-01-01

Photovoltaic devices based on poly-2,5-dioctyl-4,4"-terphenylenecyanovinylene (J-domain) and 4-aza-4-(4'-(poly-2,5'-dioctyl-4,4"-terphenylene-1-cyanovinylene-2-yl)biphen-4-yl)-8,12-dioxa-4,8,12,12c-tetrahydrodibenzo[ed,mn]pyrenium tetrafluoroborate (JA-assembly) were prepared using indiumtinoxide...... the action of the A-domain as a blocking layer and a light operated charge pump that efficiently transfers electrons to the ITO electrode. (C) 2003 Elsevier B.V. All rights reserved....

Self assembly of rectangular shapes on concentration programming and probabilistic tile assembly models.

Science.gov (United States)

Kundeti, Vamsi; Rajasekaran, Sanguthevar

2012-06-01

Efficient tile sets for self assembling rectilinear shapes is of critical importance in algorithmic self assembly. A lower bound on the tile complexity of any deterministic self assembly system for an n × n square is [Formula: see text] (inferred from the Kolmogrov complexity). Deterministic self assembly systems with an optimal tile complexity have been designed for squares and related shapes in the past. However designing [Formula: see text] unique tiles specific to a shape is still an intensive task in the laboratory. On the other hand copies of a tile can be made rapidly using PCR (polymerase chain reaction) experiments. This led to the study of self assembly on tile concentration programming models. We present two major results in this paper on the concentration programming model. First we show how to self assemble rectangles with a fixed aspect ratio ( α:β ), with high probability, using Θ( α + β ) tiles. This result is much stronger than the existing results by Kao et al. (Randomized self-assembly for approximate shapes, LNCS, vol 5125. Springer, Heidelberg, 2008) and Doty (Randomized self-assembly for exact shapes. In: proceedings of the 50th annual IEEE symposium on foundations of computer science (FOCS), IEEE, Atlanta. pp 85-94, 2009)-which can only self assembly squares and rely on tiles which perform binary arithmetic. On the other hand, our result is based on a technique called staircase sampling . This technique eliminates the need for sub-tiles which perform binary arithmetic, reduces the constant in the asymptotic bound, and eliminates the need for approximate frames (Kao et al. Randomized self-assembly for approximate shapes, LNCS, vol 5125. Springer, Heidelberg, 2008). Our second result applies staircase sampling on the equimolar concentration programming model (The tile complexity of linear assemblies. In: proceedings of the 36th international colloquium automata, languages and programming: Part I on ICALP '09, Springer-Verlag, pp 235

Modulating indium doped tin oxide electrode properties for laccase electron transfer enhancement

Energy Technology Data Exchange (ETDEWEB)

Diaconu, Mirela [National Institute for Biological Sciences, Centre of Bioanalysis, 296 Spl. Independentei, Bucharest 060031 (Romania); Chira, Ana [National Institute for Biological Sciences, Centre of Bioanalysis, 296 Spl. Independentei, Bucharest 060031 (Romania); Politehnica University of Bucharest, Faculty of Applied Chemistry and Materials Science, 1-7 Polizu Str., 011061 (Romania); Radu, Lucian, E-mail: gl_radu@chim.upb.ro [Politehnica University of Bucharest, Faculty of Applied Chemistry and Materials Science, 1-7 Polizu Str., 011061 (Romania)

2014-08-28

Indium doped tin oxide (ITO) electrodes were functionalized with gold nanoparticles (GNPs) and cysteamine monolayer to enhance the heterogeneous electron transfer process of laccase from Trametes versicolor. The assembly of GNP on ITO support was performed through generation of H{sup +} species at the electrode surface by hydroquinone electrooxidation at 0.9 V vs Ag/AgCl. Uniform distribution of gold nanoparticle aggregates on electrode surfaces was confirmed by atomic force microscopy. The size of GNP aggregates was in the range of 200–500 nm. The enhanced charge transfer at the GNP functionalized ITO electrodes was observed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy. Electrocatalytic behavior of laccase immobilized on ITO modified electrode toward oxygen reduction reaction was evaluated using CV in the presence of 2,2′-azino-bis 3-ethylbenzothiazoline-6-sulfuric acid (ABTS). The obtained sigmoidal-shaped voltammograms for ABTS reduction in oxygen saturated buffer solution are characteristic for a catalytic process. The intensity of catalytic current increased linearly with mediator concentration up to 6.2 × 10{sup −4} M. The registered voltammogram in the absence of ABTS mediator clearly showed a significant faradaic current which is the evidence of the interfacial oxygen reduction. - Highlights: • Assembly of gold nanoparticles on indium tin oxide support at positive potentials • Electrochemical and morphological evaluation of the gold nanoparticle layer assembly • Bioelectrocatalytic oxygen reduction on laccase modified electrode.

Mass relation for neutrinos

Science.gov (United States)

Babu; Barr

2000-08-07

A generalization of the well-known Georgi-Jarlskog relation (m(&mgr;)/m(tau)) = 3(m(s)/m(b)) to neutrinos is found in the context of SO(10). This new relation is (m(nu(&mgr;))/m(nu(tau))) = 16(m(c)/m(t)), which is consistent with present data, assuming the Mikheyev-Smirnov-Wolfenstein solution to the solar neutrino problem.

Preliminary CFD analysis methodology for flow in a LFR fuel assembly

International Nuclear Information System (INIS)

Catana, A.; Ioan, M.; Serbanel, M.

2013-01-01

In this paper a preliminary Computational Fluid Dynamics (CFD) analysis was performed in order to setup a methodology to be used for more complex coolant flow analysis inside ALFRED nuclear reactor fuel assembly. The core contains 171 separated fuel assembly, each consisting in a hexagonal array of 127 fuel rods. Three honey comb spacer grids are proposed along fuel rods with the aim to keep flow geometry intact during reactor operation. The main goal of this paper is to compute some hydraulic parameters: pressure, velocity, wall shear stress and turbulence parameters with and without spacer grids. In this analysis we consider an adiabatic case, so far no heat transfer is considered but we pave the road toward more complex thermo hydraulic analysis for ALFRED (LFR in general). The CAELINUX CFD distribution was used with its main components: Salome-Meca (for geometry and mesh) and Code-Saturne as mono-phase CFD solver. Paraview and Visist Postprocessors were used for data extraction and graphical displays. (authors)

Assembling large, complex environmental metagenomes

Energy Technology Data Exchange (ETDEWEB)

Howe, A. C. [Michigan State Univ., East Lansing, MI (United States). Microbiology and Molecular Genetics, Plant Soil and Microbial Sciences; Jansson, J. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division; Malfatti, S. A. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Tringe, S. G. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Tiedje, J. M. [Michigan State Univ., East Lansing, MI (United States). Microbiology and Molecular Genetics, Plant Soil and Microbial Sciences; Brown, C. T. [Michigan State Univ., East Lansing, MI (United States). Microbiology and Molecular Genetics, Computer Science and Engineering

2012-12-28

The large volumes of sequencing data required to sample complex environments deeply pose new challenges to sequence analysis approaches. De novo metagenomic assembly effectively reduces the total amount of data to be analyzed but requires significant computational resources. We apply two pre-assembly filtering approaches, digital normalization and partitioning, to make large metagenome assemblies more computationaly tractable. Using a human gut mock community dataset, we demonstrate that these methods result in assemblies nearly identical to assemblies from unprocessed data. We then assemble two large soil metagenomes from matched Iowa corn and native prairie soils. The predicted functional content and phylogenetic origin of the assembled contigs indicate significant taxonomic differences despite similar function. The assembly strategies presented are generic and can be extended to any metagenome; full source code is freely available under a BSD license.

Conditioning of spent fuel assemblies from the Rossendorf RFR research reactor in transport and storage containers of the type CASTOR MTR 2

International Nuclear Information System (INIS)

Schneider, B.; Hofmann, G.

1994-09-01

Most of the spent fuel assemblies are temporarily stored in the flooded fuel ponds AB 1 and AB 2 of the RFR, and some are still in the reactor core. The conditioning task described here is part of the RFR spent fuel management concept and covers the safe emplacement of the spent fuel elements in the CASTOR MTR 2 shipping containers and the sealing of the containers in compliance with the nuclear licence issued for the conditioning task. The transfer of the spent fuel assemblies from the present wet storage conditions to the dry storage conditions in the CASTOR MTR 2 containers is done by a mobile manipulation equipment consisting essentially of the transfer sluice gate and a transfer container. Subsequent to conditioning, the shipping containers are to be transported to a licensed intermediate storage facility to await their transport to a national radwaste repository. The technical handling tools for the transfer and manipulation are briefly described, as well as the process steps involved, putting emphasis on the detailed description of processes and the accompanying time frame, so that the conditioning task can be incorporated into the work plan of the entire project. The report further presents the EDP concept established for the task, including the required data archivation and documentation. (orig.) [de

Nuclear fuel string assembly

International Nuclear Information System (INIS)

Ip, A.K.; Koyanagi, K.; Tarasuk, W.R.

1976-01-01

A method of fabricating rodded fuels suitable for use in pressure tube type reactors and in pressure vessel type reactors is described. Fuel rods are secured as an inner and an outer sub-assembly, each rod attached between mounting rings secured to the rod ends. The two sub-assemblies are telescoped together and positioned by spaced thimbles located between them to provide precise positioning while permittng differential axial movement between the sub-assemblies. Such sub-assemblies are particularly suited for mounting as bundle strings. The method provides particular advantages in the assembly of annular-section fuel pins, which includes booster fuel containing enriched fuel material. (LL)

Fuel assembly reconstitution

International Nuclear Information System (INIS)

Morgado, Mario M.; Oliveira, Monica G.N.; Ferreira Junior, Decio B.M.; Santos, Barbara O. dos; Santos, Jorge E. dos

2009-01-01

Fuel failures have been happened in Nuclear Power Plants worldwide, without lost of integrity and safety, mainly for the public, environment and power plants workers. The most common causes of these events are corrosion (CRUD), fretting and pellet cladding interaction. These failures are identified by increasing the activity of fission products, verified by chemical analyses of reactor coolant. Through these analyses, during the fourth operation cycle of Angra 2 Nuclear Power Plant, was possible to observe fuel failure indication. This indication was confirmed in the end of the cycle during the unloading of reactor core through leakage tests of fuel assembly, using the equipment called 'In Mast Sipping' and 'Box Sipping'. After confirmed, the fuel assembly reconstitution was scheduled, and happened in April, 2007, where was identified the cause and the fuel rod failure, which was substitute by dummy rods (zircaloy). The cause was fretting by 'debris'. The actions to avoid and prevent fuel assemblies failures are important. The goals of this work are to describe the methodology of fuel assembly reconstitution using the FARE (Fuel Assembly Reconstitution Equipment) system, to describe the results of this task in economic and security factors of the company and show how the fuel assembly failures are identified during operation and during the outage. (author)

CFD evaluation of turbulence model on heat transfer in 5 × 5 rod bundles

International Nuclear Information System (INIS)

Chao Yanmeng; Yang Lixin; Zhang Yuxiang; Pang Zhengzheng

2014-01-01

Different turbulence models may lead to different results when analyzing fuel assemblies using computational fluid dynamics (CFD) method. In this paper, a 5 × 5 rod bundle model was built to analyze the relationship between flow and heat transfer. The pressure drop and Nu were calculated using ANSYS CFX. Three factors evaluating swirling flow and cross-flow were used to analyze the inner relationship between flow field and heat transfer. The performances of various turbulence models, including eddy viscosity model and Reynold stress model, were evaluated. The comparison between numerical and similar experimental results indicates that Reynold stress model is more appropriate for modeling flow features and heat transfer in spacer grids discussed in this paper. (authors)

Self-assembly of regioregular poly (3,3‴-didodecylquarterthiophene) in chloroform and study of its junction properties

Energy Technology Data Exchange (ETDEWEB)

Singh, Manish Kumar; Kumar, Ashish; Prakash, Rajiv, E-mail: rprakash.mst@iitbhu.ac.in

2017-03-15

Graphical abstract: rr-PQT-12 films formed by spin coating before and after ageing (at 25 °C) showing the effect of fiber growth and significant change in charge transfer property. - Highlights: • Self-assembly of rr-PQT-12 into fiber form in chloroform marginal solvent at RT. • As assembled dispersion is processed for the fabrication of organic devices. • Processed fiber shows improvement in charge transport over its pristine one. - Abstract: This article deals with the study of self-assembly of regioregular poly (3,3‴-didodecylquarterthiophene), rr-PQT-12 into fiber form in chloroform by ageing process. Time dependent fiber growth mechanism is monitored by UV–vis absorption and confirmed by atomic force microscopy technique. It is observed that isolated rr-PQT-12 undergoes self-assembled fibril growth along π-π interaction direction and 45 min is sufficient for such assemblies in case of 0.125% w/v of rr-PQT-12 polymer in chloroform. Further the self-assembled fibril polymer is used in fabrication of Schottky diode. It exhibits ten times enhancement in forward current density (with one-fold higher mobility) and high rectification ratio compared to the isolated rr-PQT-12 due to the segmental electronic traps filling within stacking region. Our study provides a facile method of ordering of PQT-12 isolated chains in chloroform solvent and an effective way for improvement of performance of organic polymers based devices through such self-assembly.

Electronic, structural and chemical effects of charge-transfer at organic/inorganic interfaces

Science.gov (United States)

Otero, R.; Vázquez de Parga, A. L.; Gallego, J. M.

2017-07-01

During the last decade, interest on the growth and self-assembly of organic molecular species on solid surfaces spread over the scientific community, largely motivated by the promise of cheap, flexible and tunable organic electronic and optoelectronic devices. These efforts lead to important advances in our understanding of the nature and strength of the non-bonding intermolecular interactions that control the assembly of the organic building blocks on solid surfaces, which have been recently reviewed in a number of excellent papers. To a large extent, such studies were possible because of a smart choice of model substrate-adsorbate systems where the molecule-substrate interactions were purposefully kept low, so that most of the observed supramolecular structures could be understood simply by considering intermolecular interactions, keeping the role of the surface always relatively small (although not completely negligible). On the other hand, the systems which are more relevant for the development of organic electronic devices include molecular species which are electron donors, acceptors or blends of donors and acceptors. Adsorption of such organic species on solid surfaces is bound to be accompanied by charge-transfer processes between the substrate and the adsorbates, and the physical and chemical properties of the molecules cannot be expected any longer to be the same as in solution phase. In recent years, a number of groups around the world have started tackling the problem of the adsorption, self- assembly and electronic and chemical properties of organic species which interact rather strongly with the surface, and for which charge-transfer must be considered. The picture that is emerging shows that charge transfer can lead to a plethora of new phenomena, from the development of delocalized band-like electron states at molecular overlayers, to the existence of new substrate-mediated intermolecular interactions or the strong modification of the chemical

Proactive and retroactive transfer of middle age adults in a sequential motor learning task

NARCIS (Netherlands)

Verneau, M.; Kamp, J. van der; Savelsbergh, G,J.; Looze, M.P. de

2015-01-01

We assessed the effects of aging in the transfer of motor learning in a sequential manual assembly task that is representative for real working conditions. On two different days, young (18-30years) and middle-aged adults (50-65years) practiced to build two products that consisted of the same six

Proactive and Retroactive transfer of middle age adults in a sequential motor learing task

NARCIS (Netherlands)

Verneau, M.M.N.; van der Kamp, G.J.; Savelsbergh, G.J.P.; de Looze, M.P.

2015-01-01

We assessed the effects of aging in the transfer of motor learning in a sequential manual assembly task that is representative for real working conditions. On two different days, young (18-30. years) and middle-aged adults (50-65. years) practiced to build two products that consisted of the same six

Vectorization and parallelization of a production reactor assembly code

International Nuclear Information System (INIS)

Vujic, J.L.; Martin, W.R.; Michigan Univ., Ann Arbor, MI

1991-01-01

In order to use efficiently the new features of supercomputers, production codes, usually written 10 -20 years ago, must be tailored for modern computer architectures. We have chosen to optimize the CPM-2 code, a production reactor assembly code based on the collision probability transport method. Substantial speedup in the execution times was obtained with the parallel/vector version of the CPM-2 code. In addition, we have developed a new transfer probability method, which removes some of the modelling limitations of the collision probability method encoded in the CPM-2 code, and can fully utilize the parallel/vector architecture of a multiprocessor IBM 3090. (author)

Vectorization and parallelization of a production reactor assembly code

International Nuclear Information System (INIS)

Vujic, J.L.; Martin, W.R.

1991-01-01

In order to efficiently use new features of supercomputers, production codes, usually written 10 - 20 years ago, must be tailored for modern computer architectures. We have chosen to optimize the CPM-2 code, a production reactor assembly code based on the collision probability transport method. Substantial speedups in the execution times were obtained with the parallel/vector version of the CPM-2 code. In addition, we have developed a new transfer probability method, which removes some of the modelling limitations of the collision probability method encoded in the CPM-2 code, and can fully utilize parallel/vector architecture of a multiprocessor IBM 3090. (author)

Transferred metal electrode films for large-area electronic devices

International Nuclear Information System (INIS)

Yang, Jin-Guo; Kam, Fong-Yu; Chua, Lay-Lay

2014-01-01

The evaporation of metal-film gate electrodes for top-gate organic field-effect transistors (OFETs) limits the minimum thickness of the polymer gate dielectric to typically more than 300 nm due to deep hot metal atom penetration and damage of the dielectric. We show here that the self-release layer transfer method recently developed for high-quality graphene transfer is also capable of giving high-quality metal thin-film transfers to produce high-performance capacitors and OFETs with superior dielectric breakdown strength even for ultrathin polymer dielectric films. Dielectric breakdown strengths up to 5–6 MV cm −1 have been obtained for 50-nm thin films of polystyrene and a cyclic olefin copolymer TOPAS ® (Zeon). High-quality OFETs with sub-10 V operational voltages have been obtained this way using conventional polymer dielectrics and a high-mobility polymer semiconductor poly[2,5-bis(3-tetradecylthiophene-2-yl)thieno[3,2-b]thiophene-2,5-diyl]. The transferred metal films can make reliable contacts without damaging ultrathin polymer films, self-assembled monolayers and graphene, which is not otherwise possible from evaporated or sputtered metal films

Thermal-hydraulic analysis of PWR small assembly for irradiation test of CARR

International Nuclear Information System (INIS)

Yin Hao; Zou Yao; Liu Xingmin

2015-01-01

The thermal-hydraulic behaviors of the PWR 4 × 4 small assembly tested in the high temperature and high pressure loop of China Advanced Research Reactor were analyzed. The CFD method was used to carry out 3D simulation of the model, thus detailed thermal-hydraulic parameters were obtained. Firstly, the simplified model was simulated to give the 3D temperature and velocity distributions and analyze the heat transfer process. Then the whole scale small assembly model was simulated and the simulation results were compared with those of simplified rod bundle model. Its flow behavior was studied and flow mixing characteristics of the grids were analyzed, and the mixing factor of the grid was calculated and can be used for further thermal-hydraulic study. It is shown that the highest temperature of the fuel rod meets the design limit and the mixing effect of the grid is obvious. (authors)

Reflector-moderated critical assemblies

International Nuclear Information System (INIS)

Paxton, H.C.; Jarvis, G.A.; Byers, C.C.

1975-07-01

Experiments with reflector-moderated critical assemblies were part of the Rover Program at the Los Alamos Scientific Laboratory (LASL). These assemblies were characterized by thick D 2 O or beryllium reflectors surrounding large cavities that contained highly enriched uranium at low average densities. Because interest in this type of system has been revived by LASL Plasma Cavity Assembly studies, more detailed descriptions of the early assemblies than had been available in the unclassified literature are provided. (U.S.)

Optimization of sound absorbing performance for gradient multi-layer-assembled sintered fibrous absorbers

Science.gov (United States)

Zhang, Bo; Zhang, Weiyong; Zhu, Jian

2012-04-01

The transfer matrix method, based on plane wave theory, of multi-layer equivalent fluid is employed to evaluate the sound absorbing properties of two-layer-assembled and three-layer-assembled sintered fibrous sheets (generally regarded as a kind of compound absorber or structures). Two objective functions which are more suitable for the optimization of sound absorption properties of multi-layer absorbers within the wider frequency ranges are developed and the optimized results of using two objective functions are also compared with each other. It is found that using the two objective functions, especially the second one, may be more helpful to exert the sound absorbing properties of absorbers at lower frequencies to the best of their abilities. Then the calculation and optimization of sound absorption properties of multi-layer-assembled structures are performed by developing a simulated annealing genetic arithmetic program and using above-mentioned objective functions. Finally, based on the optimization in this work the thoughts of the gradient design over the acoustic parameters- the porosity, the tortuosity, the viscous and thermal characteristic lengths and the thickness of each samples- of porous metals are put forth and thereby some useful design criteria upon the acoustic parameters of each layer of porous fibrous metals are given while applying the multi-layer-assembled compound absorbers in noise control engineering.

SWAP-Assembler 2: Optimization of De Novo Genome Assembler at Large Scale

Energy Technology Data Exchange (ETDEWEB)

Meng, Jintao; Seo, Sangmin; Balaji, Pavan; Wei, Yanjie; Wang, Bingqiang; Feng, Shengzhong

2016-08-16

In this paper, we analyze and optimize the most time-consuming steps of the SWAP-Assembler, a parallel genome assembler, so that it can scale to a large number of cores for huge genomes with the size of sequencing data ranging from terabyes to petabytes. According to the performance analysis results, the most time-consuming steps are input parallelization, k-mer graph construction, and graph simplification (edge merging). For the input parallelization, the input data is divided into virtual fragments with nearly equal size, and the start position and end position of each fragment are automatically separated at the beginning of the reads. In k-mer graph construction, in order to improve the communication efficiency, the message size is kept constant between any two processes by proportionally increasing the number of nucleotides to the number of processes in the input parallelization step for each round. The memory usage is also decreased because only a small part of the input data is processed in each round. With graph simplification, the communication protocol reduces the number of communication loops from four to two loops and decreases the idle communication time. The optimized assembler is denoted as SWAP-Assembler 2 (SWAP2). In our experiments using a 1000 Genomes project dataset of 4 terabytes (the largest dataset ever used for assembling) on the supercomputer Mira, the results show that SWAP2 scales to 131,072 cores with an efficiency of 40%. We also compared our work with both the HipMER assembler and the SWAP-Assembler. On the Yanhuang dataset of 300 gigabytes, SWAP2 shows a 3X speedup and 4X better scalability compared with the HipMer assembler and is 45 times faster than the SWAP-Assembler. The SWAP2 software is available at https://sourceforge.net/projects/swapassembler.

Characterization of Semiconductor Nanocrystal Assemblies as Components of Optoelectronic Devices

Science.gov (United States)

Malfavon-Ochoa, Mario

This dissertation presents new insight into the ability of small molecule passivated NCs to achieve intimate approach distances, despite being well passivated, while developing guiding principles in the area of ligand mediated microstructure control and the resulting macroscopic optical and electronic properties that close packing of high quality NCs enables. NC ligand coverage will be characterized quantitatively through thermogravimetric analysis (TGA), and qualitatively by photoluminescence and electroluminescence, in the case of functional devices; illustrating the importance of practitioner dependent control of ligand coverage through variations in the dispersion precipitation purification procedure. A unique examination of the relative contribution of energy and charge transfer in NC LEDs will demonstrate the ability to achieve charge transfer, at a level competitive with energy transfer, to well passivated NCs at various wt% loading in a polymer matrix. The observation of potential dependent recombination zones within an active layer further suggest novel, NC surface passivation mediated control of blend microstructure during solution processing towards the development of a bi-continuous network. Next, NC self-assembly and resulting microstructure dependent optical and electronic properties will be examined through electroluminescence and high-resolution transmission electron microscopy (TEM) micrographs of functional NC/polymer bulk heterojunction LEDs. The joint characterization of NC optical properties, and self-assembly microstructure provide a deeper understanding of the significant and inseparable effects of minimal changes in NC surface passivation on structure and function, and emphasize the potential to rely on strongly passivating ligands to control physical properties and processing parameters concurrently towards higher efficiency devices via low cost processing. Finally, micro-contact printing of blazed transmission gratings, using stable

Assembly of phosphide nanocrystals into porous networks: formation of InP gels and aerogels.

Science.gov (United States)

Hitihami-Mudiyanselage, Asha; Senevirathne, Keerthi; Brock, Stephanie L

2013-02-26

The applicability of sol-gel nanoparticle assembly routes, previously employed for metal chalcogenides, to phosphides is reported for the case of InP. Two different sizes (3.5 and 6.0 nm) of InP nanoparticles were synthesized by solution-phase arrested precipitation, capped with thiolate ligands, and oxidized with H₂O₂ or O₂/light to induce gel formation. The gels were aged, solvent-exchanged, and then supercritically dried to obtain aerogels with both meso- (2-50 nm) and macropores (>50 nm) and accessible surface areas of ∼200 m²/g. Aerogels showed higher band gap values relative to precursor nanoparticles, suggesting that during the process of assembling nanoparticles into 3D architectures, particle size reduction may have taken place. In contrast to metal chalcogenide gelation, InP gels did not form using tetranitromethane, a non-oxygen-transferring oxidant. The requirement of an oxygen-transferring oxidant, combined with X-ray photoelectron spectroscopy data showing oxidized phosphorus, suggests gelation is occurring due to condensation of phosphorus oxoanionic moieties generated at the interfaces. The ability to link discrete InP nanoparticles into a 3D porous network while maintaining quantum confinement is expected to facilitate exploitation of nanostructured InP in solid-state devices.

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

Science.gov (United States)

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

2015-06-01

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

Crystalline mono- and multilayer self-assemblies of oligothiophenes at the air-water interface

DEFF Research Database (Denmark)

Isz, S.; Weissbuch, I.; Kjær, K.

1997-01-01

The formation of Langmuir monolayers at the air-water interface has long been believed to be limited to amphiphilic molecules containing a hydrophobic chain and a hydrophilic headgroup. Here we report the formation of crystalline mono- and multilayer self-assemblies of oligothiophenes, a class...... of aromatic nonamphiphilic molecules, self-aggregated at the air-water interface. As model systems we have examined the deposition of quaterthiophene (S-4), quinquethiophene (S-5). and sexithiophene (S-6) from chloroform solutions on the water surface. The structures of the films were determined by surface...... surface. S-5 self-ageregates at the water surface to form mixtures of monolayers and bilayers of the beta polymorph; S-6 forms primarily crystalline monolayers of both alpha and beta forms. The crystalline assemblies preserve their integrity during transfer from the water surface onto solid supports...

Wire-type MnO2/Multilayer graphene/Ni electrode for high-performance supercapacitors

Science.gov (United States)

Hu, Minglei; Liu, Yuhao; Zhang, Min; Wei, Helin; Gao, Yihua

2016-12-01

Commercially available wearable energy storage devices need a wire-type electrode with high strength, conductivity and electrochemical performance, as well as stable structure under deformation. Herein, we report a novel wire-type electrode of hierarchically structure MnO2 on Ni wire with multilayer graphene (MGr) as a buffer layer to enhance the electrical conductivity of the MnO2 and interface contact between the MnO2 and Ni wire. Thus, the wire-type MnO2/MGr/Ni electrode has a stable and high quality interface. The wire-type supercapacitor (WSC) based on wire-type MnO2/MGr/Ni electrode exhibits good electrochemical performance, high rate capability, extraordinary flexibility, and superior cycle lifetime. Length (area, volumetric) specific capacitance of the WSC reaches 6.9 mF cm-1 (73.2 mF cm-2, 9.8 F cm-3). Maximum length (volumetric) energy density of the WSC based on MnO2/MGr/Ni reaches 0.62 μWh cm-1 (0.88 mWh cm-3). Furthermore, the WSC has a short time constant (0.5-400 ms) and exhibits minimal change in capacitance under different bending shapes.

Molecular self-assembly approaches for supramolecular electronic and organic electronic devices

Science.gov (United States)

Yip, Hin-Lap

Molecular self-assembly represents an efficient bottom-up strategy to generate structurally well-defined aggregates of semiconducting pi-conjugated materials. The capability of tuning the chemical structures, intermolecular interactions and nanostructures through molecular engineering and novel materials processing renders it possible to tailor a large number of unprecedented properties such as charge transport, energy transfer and light harvesting. This approach does not only benefit traditional electronic devices based on bulk materials, but also generate a new research area so called "supramolecular electronics" in which electronic devices are built up with individual supramolecular nanostructures with size in the sub-hundred nanometers range. My work combined molecular self-assembly together with several novel materials processing techniques to control the nucleation and growth of organic semiconducting nanostructures from different type of pi-conjugated materials. By tailoring the interactions between the molecules using hydrogen bonds and pi-pi stacking, semiconducting nanoplatelets and nanowires with tunable sizes can be fabricated in solution. These supramolecular nanostructures were further patterned and aligned on solid substrates through printing and chemical templating methods. The capability to control the different hierarchies of organization on surface provides an important platform to study their structural-induced electronic properties. In addition to using molecular self-assembly to create different organic nanostructures, functional self-assembled monolayer (SAM) formed by spontaneous chemisorption on surfaces was used to tune the interfacial property in organic solar cells. Devices showed dramatically improved performance when appropriate SAMs were applied to optimize the contact property for efficiency charge collection.

Photochemical properties and interfacial fluorescence sensing for homocysteine of triptycene orthoquinone layer-by-layer-assembled multilayers

International Nuclear Information System (INIS)

Sun, Xiangying; Liu, Bin; Wu, Qiong; Li, Fang

2014-01-01

In the present work, the properties of triptycene orthoquinone derivatives were studied. As a kind of good electron-transfer platform, triptycene derivatives with different electron donors or electron acceptors behave distinctively with their luminescent properties. The intensity ratio of fluorescence peaks can be controlled by the number of methoxy groups (electron donor) and orthoquinone groups (electron acceptor) simultaneously. We have assembled 6,7,12,13-4-methoxyl-2, 3-2-orthoquinone triptycene onto self-assembled monolayers (SAMs) to create a probe for detecting biological thiols. The SAMs exhibited higher selectivity toward homocysteine than to other thiol-containing compounds with a fast response and a stable signal over a wide liner range from 2.0 μmol/L to 1.0 mmol/L with the detection limit of 0.52 μmol/L. - Highlights: • A dual fluorescence probe for biological thiols was reported. • This probe is based on triptycene orthoquinones self-assembled mutilayers. • The sensor exhibits higher selectivity toward homocysteine than other thiol compounds

Photochemical properties and interfacial fluorescence sensing for homocysteine of triptycene orthoquinone layer-by-layer-assembled multilayers

Energy Technology Data Exchange (ETDEWEB)

Sun, Xiangying, E-mail: sunxy@hqu.edu.cn; Liu, Bin; Wu, Qiong; Li, Fang

2014-07-01

In the present work, the properties of triptycene orthoquinone derivatives were studied. As a kind of good electron-transfer platform, triptycene derivatives with different electron donors or electron acceptors behave distinctively with their luminescent properties. The intensity ratio of fluorescence peaks can be controlled by the number of methoxy groups (electron donor) and orthoquinone groups (electron acceptor) simultaneously. We have assembled 6,7,12,13-4-methoxyl-2, 3-2-orthoquinone triptycene onto self-assembled monolayers (SAMs) to create a probe for detecting biological thiols. The SAMs exhibited higher selectivity toward homocysteine than to other thiol-containing compounds with a fast response and a stable signal over a wide liner range from 2.0 μmol/L to 1.0 mmol/L with the detection limit of 0.52 μmol/L. - Highlights: • A dual fluorescence probe for biological thiols was reported. • This probe is based on triptycene orthoquinones self-assembled mutilayers. • The sensor exhibits higher selectivity toward homocysteine than other thiol compounds.

Life-cycle cost implications of a system using bare SNF transfer

International Nuclear Information System (INIS)

Rose, M.

1995-01-01

The U.S. Department of Energy (DOE) is planning the use of the Multi-Purpose Canister (MPC) to handle transportation, storage, and disposal of civilian spent nuclear fuel. This canister, which would be loaded and sealed at the utility site, would remain sealed through waste emplacement in a Mined Geologic Disposal System (MGDS). Two sizes of MPCs are now being considered: large and small rail. The large rail canister has design requirements to be compatible with a 125 ton hook weight crane when fully loaded in the pool with fuel assemblies, water, transportation overpack, and the lifting yoke. The small rail canister under the same conditions weighs less than 75 tons. At present, it is estimated that between four and seventeen reactors will not be able to accommodate either canister. One method of accommodating MPCs at all reactors is the use of Bare Spent nuclear fuel Transfer (BST). In this concept, a small transfer cask is used to move small numbers of assemblies from the spent fuel pool to an external transfer station where a large MPC is loaded. After several of these transfers, the MPC is sealed and either stored on-site, transported to a central storage site, or transported to the MGDS. This paper addresses the total system cost implications of use of BST at 20 sites (31 reactors) which are currently projected to be unable to use the large rail MPC. Results are presented parametrically as a function of the BST capital cost and the time required to load a MPC. This analysis indicates use of BST may be economically favorable if the combination of MPC load times and capital expenditures can be kept to a reasonable level

Polymer Directed Protein Assemblies

NARCIS (Netherlands)

van Rijn, Patrick

2013-01-01

Protein aggregation and protein self-assembly is an important occurrence in natural systems, and is in some form or other dictated by biopolymers. Very obvious influences of biopolymers on protein assemblies are, e. g., virus particles. Viruses are a multi-protein assembly of which the morphology is

Wire-wrapped rod-bundle heat-transfer analysis for LMFBR

International Nuclear Information System (INIS)

Wong, C.N.C.; Todreas, N.E.

1982-07-01

Helical wire wraps are widely used in the LMFBR fuel and blanket assemblies to provide coolant mixing and maintain proper spacing between fuel pins. The presence of the helical wire, however, may possibly induce heat transfer problems, such as the uncertainty of the maximum clad temperature as a result of the contact between the wires and the pins. In this study, the detailed transient three dimensional velocity and temperature distributions for the coolant around the pin will be determined by solving the governing momentum and energy equation numerically. A computer code HEATRAN has been developed to perform this calculation. Before the computer code HEATRAN is applied to the wire wrapped rod bundle problem, it is used to analyze a wide range of fluid and heat transfer problem to verify its capabilities

Charge separation and transfer in hybrid type II tunneling structures of CdTe and CdSe nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Gross, Dieter Konrad Michael

2013-11-08

Closely packed nanocrystal systems have been investigated in this thesis with respect to charge separation by charge carrier tunneling. Clustered and layered samples have been analyzed using PL-measurements and SPV-methods. The most important findings are reviewed in the following. A short outlook is also provided for potential further aspects and application of the presented results. The main purpose of this thesis was to find and quantify electronic tunneling transfer in closely packed self-assembled nanocrystal structures presenting quantum mechanical barriers of about 1 nm width. We successfully used hybrid assemblies of CdTe and CdSe nanocrystals where the expected type II alignment between CdTe and CdSe typically leads to a concentration of electrons in CdSe and holes in CdTe nanocrystals. We were able to prove the charge selectivity of the CdTe-CdSe nanocrystal interface which induces charge separation. We mainly investigated the effects related to the electron transfer from CdTe to CdSe nanocrystals. Closely packing was achieved by two independent methods: the disordered colloidal clustering in solution and the layered assembly on dry glass substrates. Both methods lead to an inter-particle distance of about 1 nm of mainly organic material which acts as a tunneling barrier. PL-spectroscopy was applied. The PL-quenching of the CdTe nanocrystals in hybrid assemblies indicates charge separation by electron transfer from CdTe to CdSe nanocrystals. A maximum quenching rate of up to 1/100 ps was measured leading to a significant global PL-quenching of up to about 70 % for the CdTe nanocrystals. It was shown that charge separation dynamics compete with energy transfer dynamics and that charge separation typically dominates. The quantum confinement effect was used to tune the energetic offset between the CdTe and CdSe nanocrystals. We thus observe a correlation of PL-quenching and offset of the energy states for the electron transfer. The investigated PL

Charge separation and transfer in hybrid type II tunneling structures of CdTe and CdSe nanocrystals

International Nuclear Information System (INIS)

Gross, Dieter Konrad Michael

2013-01-01

Closely packed nanocrystal systems have been investigated in this thesis with respect to charge separation by charge carrier tunneling. Clustered and layered samples have been analyzed using PL-measurements and SPV-methods. The most important findings are reviewed in the following. A short outlook is also provided for potential further aspects and application of the presented results. The main purpose of this thesis was to find and quantify electronic tunneling transfer in closely packed self-assembled nanocrystal structures presenting quantum mechanical barriers of about 1 nm width. We successfully used hybrid assemblies of CdTe and CdSe nanocrystals where the expected type II alignment between CdTe and CdSe typically leads to a concentration of electrons in CdSe and holes in CdTe nanocrystals. We were able to prove the charge selectivity of the CdTe-CdSe nanocrystal interface which induces charge separation. We mainly investigated the effects related to the electron transfer from CdTe to CdSe nanocrystals. Closely packing was achieved by two independent methods: the disordered colloidal clustering in solution and the layered assembly on dry glass substrates. Both methods lead to an inter-particle distance of about 1 nm of mainly organic material which acts as a tunneling barrier. PL-spectroscopy was applied. The PL-quenching of the CdTe nanocrystals in hybrid assemblies indicates charge separation by electron transfer from CdTe to CdSe nanocrystals. A maximum quenching rate of up to 1/100 ps was measured leading to a significant global PL-quenching of up to about 70 % for the CdTe nanocrystals. It was shown that charge separation dynamics compete with energy transfer dynamics and that charge separation typically dominates. The quantum confinement effect was used to tune the energetic offset between the CdTe and CdSe nanocrystals. We thus observe a correlation of PL-quenching and offset of the energy states for the electron transfer. The investigated PL

Core/coil assembly for use in superconducting magnets and method for assembling the same

Science.gov (United States)

Kassner, David A.

1979-01-01

A core/coil assembly for use in a superconducting magnet of the focusing or bending type used in syncronous particle accelerators comprising a coil assembly contained within an axial bore of the stacked, washer type, carbon steel laminations which comprise the magnet core assembly, and forming an interference fit with said laminations at the operating temperature of said magnet. Also a method for making such core/coil assemblies comprising the steps of cooling the coil assembly to cryogenic temperatures and drawing it rapidly upwards into the bore of said stacked laminations.

Wildlife resource utilisation at Moremi Game Reserve and Khwai community area in the Okavango Delta, Botswana.

Science.gov (United States)

Mbaiwa, Joseph E

2005-10-01

This paper uses the concept of sustainable development to examine the utilisation of wildlife resources at Moremi Game Reserve (MGR) and Khwai community area (NG 18/19) in the Okavango Delta, Botswana. Using both secondary and primary data sources, results show that the establishment of MGR in 1963 led to the displacement of Khwai residents from their land; affected Basarwa's hunting and gathering economy; marked the beginning of resource conflicts between Khwai residents and wildlife managers; and, led to the development of negative attitudes of Khwai residents towards wildlife conservation. Since the late 1980s, a predominantly foreign owned tourism industry developed in and around MGR, however, Khwai residents derive insignificant benefits from it and hence resource conflicts increased. In an attempt to address problems of resource conflicts and promote sustainable wildlife utilisation, the Botswana Government adopted the Community-Based Natural Resource Management (CBNRM) programme, which started operating at Khwai village in 2000. The CBNRM programme promotes local participation in natural resource management and rural development through tourism. It is beginning to have benefits to Khwai residents such as income generation, employment opportunities and local participation in wildlife management. These benefits from CBNRM are thus having an impact in the development of positive attitudes of Khwai residents towards wildlife conservation and tourism development. This paper argues that if extended to MGR, CBNRM has the potential of minimising wildlife conflicts between Khwai residents and the wildlife-tourism sectors. This approach may in the process promote the sustainable wildlife use in and around MGR.

Mapping the heparin-binding site of the BMP antagonist gremlin by site-directed mutagenesis based on predictive modelling.

Science.gov (United States)

Tatsinkam, Arnold Junior; Mulloy, Barbara; Rider, Christopher C

2015-08-15

Gremlin is a member of the CAN (cerberus and DAN) family of secreted BMP (bone morphogenetic protein) antagonists and also an agonist of VEGF (vascular endothelial growth factor) receptor-2. It is critical in limb skeleton and kidney development and is re-expressed during tissue fibrosis. Gremlin binds strongly to heparin and heparan sulfate and, in the present study, we sought to investigate its heparin-binding site. In order to explore a putative non-contiguous binding site predicted by computational molecular modelling, we substituted a total of 11 key arginines and lysines located in three basic residue sequence clusters with homologous sequences from cerberus and DAN (differential screening selected gene abberative in neuroblastoma), CAN proteins which lack basic residues in these positions. A panel of six Myc-tagged gremlin mutants, MGR-1-MGR-6 (MGR, mutant gremlin), each containing different combinations of targeted substitutions, all showed markedly reduced affinity for heparin as demonstrated by their NaCl elution on heparin affinity chromatography, thus verifying our predictions. Both MGR-5 and MGR-6 retained BMP-4-binding activity comparable to that of wild-type gremlin. Low-molecular-mass heparin neither promoted nor inhibited BMP-4 binding. Finally, glutaraldehyde cross-linking demonstrated that gremlin forms non-covalent dimers, similar behaviour to that of DAN and also PRDC (protein related to cerberus and DAN), another CAN protein. The resulting dimer would possess two heparin-binding sites, each running along an exposed surface on the second β-strand finger loop of one of the monomers. © 2015 Authors; published by Portland Press Limited.

Spent nuclear fuel assembly storage vessel

International Nuclear Information System (INIS)

Yagishita, Takuya

1998-01-01

The vessel of the present invention promotes an effect of removing after heat of spent nuclear fuel assemblies so as not to give force to the storage vessel caused by expansion of heat removing partitioning plates. Namely, the vessel of the present invention comprises a cylinder body having closed upper and lower portions and a plurality of heat removing partitioning cylinders disposed each at a predetermined interval in the circumferential direction of the above-mentioned cylinder body. The heat removing partitioning cylinders comprises (1) first heat removing partitioning plates extended in the radial direction of the cylinder body and opposed at a predetermined gap in the circumferential direction of the cylinder body, and having the base ends on the side of the inner wall of the cylinder body being secured to the inner wall of the cylinder body and (2) a second heat removing plate for connecting the top ends of both opposed heat removing partitioning plates on the central side of the cylinder body with each other. Spent nuclear fuel assemblies are contained in a plurality of closed spaces surrounded by the first heat removing partitioning plates and the second heat removing partitioning plate. With such constitution, since after heat is partially transferred from the heat removing partitioning plates to the cylindrical body directly by heat conduction, the heat removing effect can be promoted compared with the prior art. (I.S.)

Laser-Assisted Simultaneous Transfer and Patterning of Vertically Aligned Carbon Nanotube Arrays on Polymer Substrates for Flexible Devices

KAUST Repository

In, Jung Bin; Lee, Daeho; Fornasiero, Francesco; Noy, Aleksandr; Grigoropoulos, Costas P.

2012-01-01

We demonstrate a laser-assisted dry transfer technique for assembling patterns of vertically aligned carbon nanotube arrays on a flexible polymeric substrate. A laser beam is applied to the interface of a nanotube array and a polycarbonate sheet

Surface reconstitution of glucose oxidase onto a norbornylogous bridge self-assembled monolayer

International Nuclear Information System (INIS)

Liu Jingquan; Paddon-Row, Michael N.; Gooding, J. Justin

2006-01-01

An electrode construct was fabricated in which a self-assembled monolayer containing a novel norbornylogous bridge was covalently attached to flavin adenine dinucleotide (FAD), the redox active centre of several oxidase enzymes. The electrochemistry of the construct was investigated before and after the reconstitution of glucose oxidase around the surface bound FAD. Rapid rates of electron transfer were observed both before and after the reconstitution of biocatalytically active enzyme. However, no biocatalytic activity was observed under anaerobic conditions suggesting the a lack of enzyme turnover through direct electron transfer. It is proposed that a decrease in the electronic coupling between the redox active FAD and the electrode following reconstitution of the glucose oxidase - a probable consequence of the FAD being immersed in a protein environment - was responsible for the inability of the enzyme to be turned over under anaerobic conditions

Nuclear fuel assemblies and fuel pins usable in such assemblies

International Nuclear Information System (INIS)

Jolly, R.

1982-01-01

A novel end cap for a nuclear fuel assembly is described in detail. It consists of a trisection arrangement which is received within a cell of a cellular grid. The cell contains abutment means with which the trisection comes into abutment. The grid also contains an abutment means for preventing the trisections from being inserted into the cell in an incorrect orientation. The present design allows fuel pins to be securely held in a hold-down grid of a sub-assembly. The design also allows easier dis-assembly of the swollen and embrittled fuel pins prior to reprocessing. (U.K.)

Charge separation and transfer in hybrid type II tunneling structures of CdTe and CdSe nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Gross, Dieter Konrad Michael

2013-11-08

Closely packed nanocrystal systems have been investigated in this thesis with respect to charge separation by charge carrier tunneling. Clustered and layered samples have been analyzed using PL-measurements and SPV-methods. The most important findings are reviewed in the following. A short outlook is also provided for potential further aspects and application of the presented results. The main purpose of this thesis was to find and quantify electronic tunneling transfer in closely packed self-assembled nanocrystal structures presenting quantum mechanical barriers of about 1 nm width. We successfully used hybrid assemblies of CdTe and CdSe nanocrystals where the expected type II alignment between CdTe and CdSe typically leads to a concentration of electrons in CdSe and holes in CdTe nanocrystals. We were able to prove the charge selectivity of the CdTe-CdSe nanocrystal interface which induces charge separation. We mainly investigated the effects related to the electron transfer from CdTe to CdSe nanocrystals. Closely packing was achieved by two independent methods: the disordered colloidal clustering in solution and the layered assembly on dry glass substrates. Both methods lead to an inter-particle distance of about 1 nm of mainly organic material which acts as a tunneling barrier. PL-spectroscopy was applied. The PL-quenching of the CdTe nanocrystals in hybrid assemblies indicates charge separation by electron transfer from CdTe to CdSe nanocrystals. A maximum quenching rate of up to 1/100 ps was measured leading to a significant global PL-quenching of up to about 70 % for the CdTe nanocrystals. It was shown that charge separation dynamics compete with energy transfer dynamics and that charge separation typically dominates. The quantum confinement effect was used to tune the energetic offset between the CdTe and CdSe nanocrystals. We thus observe a correlation of PL-quenching and offset of the energy states for the electron transfer. The investigated PL

Self-assembly of coiled coil peptides into nanoparticles vs 2-d plates: effects of assembly pathway

Science.gov (United States)

Kim, Kyunghee; Pochan, Darrin

Molecular solution assembly, or self-assembly, is a process by which ordered nanostructures or patterns are formed by non-covalent interactions during assembly. Biomimicry, the use of bioinspired molecules or biologically relevant materials, is an important area of self-assembly research with peptides serving a critical role as molecular tools. The morphology of peptide assemblies can be controlled by adjusting solution conditions such as the concentration of peptides, the temperature, and pH. Herein, spherical nanostructures, which have potential for creating an encapsulation system, are formed by self-assembly when coiled coil peptides are combined in solution. These peptides are homotrimeric and heterodimeric coiled-coil bundles and the homotrimer is connected with each of heterodimer through their external surfaces via disulfide bonds. The resultant covalent constructs could co-assemble into complementary trimeric hubs, respectively. The two peptide constructs are directly mixed and assembled in solution in order to produce either spherical particles or 2-d plates depending on the solution conditions and kinetic pathway of assembly. In particular, structural changes of the self-assembled peptides are explored by control of the thermal history of the assembly solution.

Crystal Structure and Magnetic Behavior of Two New Dinuclear Carbonato-Bridged Copper(II) Compounds. Superexchange Pathway for the Different Coordination Modes of the Carbonato Bridge in Polynuclear Copper(II) Compounds.

Science.gov (United States)

Escuer, Albert; Mautner, Franz A.; Peñalba, Evaristo; Vicente, Ramon

1998-08-24

Four new &mgr;-CO(3)(2-) copper(II) complexes with different coordination modes for the carbonato bridge have been obtained by fixation of atmospheric CO(2): {(&mgr;(3)-CO(3))[Cu(3)(ClO(4))(3)(Et(3)dien)(3)]}(ClO(4)) (1), Et(3)dien = N,N',N"-triethylbis(2-aminoethane)amine; {(&mgr;-CO(3))[Cu(2)(H(2)O)(Et(4)dien)(2)]}(ClO(4))(2).H(2)O (2), Et(4)dien = N,N,N",N"-tetraethyl-bis(2-aminoethane)amine; {(&mgr;-CO(3))[Cu(2)(H(2)O)(2)(EtMe(4)dien)(2)]} (ClO(4))(2).2H(2)O (3), EtMe(4)dien = N'-ethyl-N,N,N",N"-tetramethylbis(2-aminoethane)amine; and {(&mgr;-CO(3))[Cu(2)(H(2)O)(Me(5)dien)(2)]}(ClO(4))(2).H(2)O (4), Me(5)dien = N,N,N',N",N"-pentamethylbis(2-aminoethane)amine. The crystal structures have been solved for 2, monoclinic system, space group P2(1)/n, formula [C(25)H(62)Cl(2)Cu(2)N(6)O(13)] with a = 12.763(6) Å, b = 25.125(8) Å, c = 13.261(4) Å, beta = 111.85(3) degrees, Z = 4, and for 3, triclinic system, space group P&onemacr;, formula [C(21)H(58)Cl(2)Cu(2)N(6)O(15)] with a = 8.412(3) Å, b = 14.667(4) Å, c = 16.555(5) Å, alpha = 99.66(2) degrees, beta = 102.14(2) degrees, gamma = 104.72(2) degrees, Z = 2. Susceptibility measurements show ferromagnetic behavior (J = +6.7(6) cm(-)(1)) for the trinuclear compound 1 whereas 2-4 are antiferromagnetically coupled with J = -17.8(8), -125.5(9), and -21.2(3) cm(-)(1) respectively. Certain synthetic aspects that may be related to the nuclearity of the copper(II) &mgr;-CO(3)(2-) compounds and the superexchange pathway for the different coordination modes of the carbonato bridge are discussed.

Nodewise analytical calculation of the transfer function

International Nuclear Information System (INIS)

Makai, Mihaly

1994-01-01

The space dependence of neutron noise has so far been mostly investigated in homogeneous core models. Application of core diagnostic methods to locate a malfunction requires however that the transfer function be calculated for real, inhomogeneous cores. A code suitable for such purpose must be able to handle complex arithmetic and delta-function source. Further requirements are analytical dependence in one spatial variable and fast execution. The present work describes the TIDE program written to fulfil the above requirements. The core is subdivided into homogeneous, square assemblies. An analytical solution is given, which is a generalisation of the inhomogeneous response matrix method. (author)

Rapid centriole assembly in Naegleria reveals conserved roles for both de novo and mentored assembly.

Science.gov (United States)

Fritz-Laylin, Lillian K; Levy, Yaron Y; Levitan, Edward; Chen, Sean; Cande, W Zacheus; Lai, Elaine Y; Fulton, Chandler

2016-03-01

Centrioles are eukaryotic organelles whose number and position are critical for cilia formation and mitosis. Many cell types assemble new centrioles next to existing ones ("templated" or mentored assembly). Under certain conditions, centrioles also form without pre-existing centrioles (de novo). The synchronous differentiation of Naegleria amoebae to flagellates represents a unique opportunity to study centriole assembly, as nearly 100% of the population transitions from having no centrioles to having two within minutes. Here, we find that Naegleria forms its first centriole de novo, immediately followed by mentored assembly of the second. We also find both de novo and mentored assembly distributed among all major eukaryote lineages. We therefore propose that both modes are ancestral and have been conserved because they serve complementary roles, with de novo assembly as the default when no pre-existing centriole is available, and mentored assembly allowing precise regulation of number, timing, and location of centriole assembly. © 2016 Wiley Periodicals, Inc.

Next-generation transcriptome assembly

Energy Technology Data Exchange (ETDEWEB)

Martin, Jeffrey A.; Wang, Zhong

2011-09-01

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.

Do semantic contextual cues facilitate transfer learning from video in toddlers?

Science.gov (United States)

Zimmermann, Laura; Moser, Alecia; Grenell, Amanda; Dickerson, Kelly; Yao, Qianwen; Gerhardstein, Peter; Barr, Rachel

2015-01-01

Young children typically demonstrate a transfer deficit, learning less from video than live presentations. Semantically meaningful context has been demonstrated to enhance learning in young children. We examined the effect of a semantically meaningful context on toddlers' imitation performance. Two- and 2.5-year-olds participated in a puzzle imitation task to examine learning from either a live or televised model. The model demonstrated how to assemble a three-piece puzzle to make a fish or a boat, with the puzzle demonstration occurring against a semantically meaningful background context (ocean) or a yellow background (no context). Participants in the video condition performed significantly worse than participants in the live condition, demonstrating the typical transfer deficit effect. While the context helped improve overall levels of imitation, especially for the boat puzzle, only individual differences in the ability to self-generate a stimulus label were associated with a reduction in the transfer deficit.

Behavior of the turbine - regenerating preheaters functional assembly

International Nuclear Information System (INIS)

Bigu, Melania; Nita, Iulian Pavel; Tenescu, Mircea

2004-01-01

In the classical calculation of pressure distribution in the turbine-regenerating heaters' assembly a uniform distribution of feedwater enthalpy rise at each regenerating preheating step is usually assumed. This is accurately enough as a basis of designing of the preheating installation operating at rated power regime. But at partial regimes this is not totally valid since the preheaters are already shaped and the quasi-equal distribution does not satisfy the equation system describing the heat transfer correlations in these installations. A more detailed analysis shows that pressure in the feeding line preheaters and the bleeding steam flow rates at the turbine outlets are described physically by solving simultaneously the equations of hydrodynamic flow through the turbine and the equations of the heat transfer in the preheaters of the feedwater preheating line. This work approaches this more accurate solving method at least from a theoretical standing point; two cases are illustrated in the annexes of the work: a case of a secondary circuit with a single regenerating inlet and a case with two regenerating inlets. A classical - Panzer method of transformation of a many regenerative stages scheme may lead to one or another of the above cases. (authors)

Human Assisted Assembly Processes

Energy Technology Data Exchange (ETDEWEB)

CALTON,TERRI L.; PETERS,RALPH R.

2000-01-01

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

Gelation induced supramolecular chirality: chirality transfer, amplification and application.

Science.gov (United States)

Duan, Pengfei; Cao, Hai; Zhang, Li; Liu, Minghua

2014-08-14

Supramolecular chirality defines chirality at the supramolecular level, and is generated from the spatial arrangement of component molecules assembling through non-covalent interactions such as hydrogen bonding, van der Waals interactions, π-π stacking, hydrophobic interactions and so on. During the formation of low molecular weight gels (LMWGs), one kind of fascinating soft material, one frequently encounters the phenomenon of chirality as well as chiral nanostructures, either from chiral gelators or even achiral gelators. A view of gelation-induced supramolecular chirality will be very helpful to understand the self-assembly process of the gelator molecules as well as the chiral structures, the regulation of the chirality in the gels and the development of the "smart" chiral materials such as chiroptical devices, catalysts and chiral sensors. It necessitates fundamental understanding of chirality transfer and amplification in these supramolecular systems. In this review, recent progress in gelation-induced supramolecular chirality is discussed.

Self-Assembly of Infinite Structures

Directory of Open Access Journals (Sweden)

Scott M. Summers

2009-06-01

Full Text Available We review some recent results related to the self-assembly of infinite structures in the Tile Assembly Model. These results include impossibility results, as well as novel tile assembly systems in which shapes and patterns that represent various notions of computation self-assemble. Several open questions are also presented and motivated.

Nuclear fuel assembly

International Nuclear Information System (INIS)

Anthony, A.J.

1980-01-01

A bimetallic spacer means is cooperatively associated with a nuclear fuel assembly and operative to resist the occurrence of in-reactor bowing of the nuclear fuel assembly. The bimetallic spacer means in one embodiment of the invention includes a space grid formed, at least principally, of zircaloy to the external surface of which are attached a plurality of stainless steel strips. In another embodiment the strips are attached to fuel pins. In each of the embodiments, the stainless steel strips during power production expand outwardly to a greater extent than do the members to which the stainless steel strips are attached, thereby forming stiff springs which abut against like bimetallic spacer means with which the other nuclear fuel assemblies are provided in a given nuclear reactor core to thus prevent the occurrence of in-reactor bowing of the nuclear fuel assemblies. (author)

Nuclear fuel assembly

International Nuclear Information System (INIS)

Betten, P.R.

1976-01-01

Under the invention the fuel assembly is particularly suitable for liquid metal cooled fast neutron breeder reactors. Hence, according to the invention a fuel assembly cladding includes inward corrugations with respect to the remainder of the cladding according to a recurring pattern determined by the pitch of the metal wire helically wound round the fuel rods of the assembly. The parts of the cladding pressed inwards correspond to the areas in which the wire encircling the peripheral fuel rods is generally located apart from the cladding, thereby reducing the play between the cladding and the peripheral fuel rods situated in these areas. The reduction in the play in turn improves the coolant flow in the internal secondary channels of the fuel assembly to the detriment of the flow in the peripheral secondary channels and thereby establishes a better coolant fluid temperature profile [fr

Assembly of contactors-separators in an extraction unit

International Nuclear Information System (INIS)

Beaujard, Jean; Menes, J.-C.; Ravoire, Jean.

1977-01-01

A description is given of an assembly of contactors-separators of an installation in which a transfer of mass or an isotope exchange occurs between two non miscible phases, characterized in that the contactors-separators are associated in m lines and n columns, one of the phases issuing from a contactor-separator being sent directly to the next contactor-separator of the same line, whilst the other phase, issuing from the same contactor-separator is sent directly to the next contactor-separator of the same column, each of the m lines and n columns being provided with one only pumping facility, the instantaneous flow rate of each phase, at the intake and outlet of each contactor-separator being appreciably identical [fr

Method and apparatus for assembling a permanent magnet pole assembly

Science.gov (United States)

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

2009-08-11

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

TPX assembly plan

International Nuclear Information System (INIS)

Knutson, D.

1993-01-01

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

Transfer of Direct and Moiré Patterns by Reactive Ion Etching Through Ex Situ Fabricated Nanoporous Polymer Masks

DEFF Research Database (Denmark)

Shvets, Violetta; Hentschel, Thomas; Schulte, Lars

2015-01-01

modification, which are essential prerequisites for the conventional procedure of block copolymer directed self-assembly. The demonstrated elliptic and moire pattern transfers prove that the proposed ex situ procedure allows us to realize nanolithographic patterns that are difficult to realize...

Laser-assisted simultaneous transfer and patterning of vertically aligned carbon nanotube arrays on polymer substrates for flexible devices.

Science.gov (United States)

In, Jung Bin; Lee, Daeho; Fornasiero, Francesco; Noy, Aleksandr; Grigoropoulos, Costas P

2012-09-25

We demonstrate a laser-assisted dry transfer technique for assembling patterns of vertically aligned carbon nanotube arrays on a flexible polymeric substrate. A laser beam is applied to the interface of a nanotube array and a polycarbonate sheet in contact with one another. The absorbed laser heat promotes nanotube adhesion to the polymer in the irradiated regions and enables selective pattern transfer. A combination of the thermal transfer mechanism with rapid direct writing capability of focused laser beam irradiation allows us to achieve simultaneous material transfer and direct micropatterning in a single processing step. Furthermore, we demonstrate that malleability of the nanotube arrays transferred onto a flexible substrate enables post-transfer tailoring of electric conductance by collapsing the aligned nanotubes in different directions. This work suggests that the laser-assisted transfer technique provides an efficient route to using vertically aligned nanotubes as conductive elements in flexible device applications.

EXPERIMENTAL STUDY OF LOCAL HYDRODYNAMICS AND MASS EXCHANGE PROCESSES OF COOLANT IN FUEL ASSEMBLIES OF PRESSURIZED WATER REACTORS

Directory of Open Access Journals (Sweden)

S. M. Dmitriev

2016-01-01

Full Text Available The results of experimental studies of local hydrodynamics and mass exchange of coolant flow behind spacer and mixing grids of different structural versions that were developed for fuel assemblies of domestic and foreign nuclear reactors are presented in the article. In order to carry out the study the models of the following fuel assemblies have been fabricated: FA for VVER and VBER, FA-KVADRAT for PWR-reactor and FA for KLT-40C reactor. All the models have been fabricated with a full geometrical similarity with full-scale fuel assemblies. The study was carried out by simulating the flow of coolant in a core by air on an aerodynamic test rig. In order to measure local hydrodynamic characteristics of coolant flow five-channel Pitot probes were used that enable to measure the velocity vector in a point by its three components. The tracerpropane method was used for studying mass transfer processes. Flow hydrodynamics was studied by measuring cross-section velocities of coolant flow and coolant rates according to the model cells. The investigation of mass exchange processes consisted of a study of concentration distribution for tracer in experimental model, in determination of attenuation lengths of mass transfer processes behind mixing grids, in calculating of inter-cellar mass exchange coefficient. The database on coolant flow in fuel assemblies for different types of reactors had been accumulated that formed the basis of the engineering substantiation of reactor cores designs. The recommendations on choice of optimal versions of mixing grids have been taken into consideration by implementers of the JSC “OKBM Afrikantov” when creating commissioned fuel assemblies. The results of the study are used for verification of CFD-codes and CFD programs of detailed cell-by-cell calculation of reactor cores in order to decrease conservatism for substantiation of thermal-mechanical reliability.

Study of the thermo-mechanical performances of the IFMIF-EVEDA Lithium Test Loop target assembly

Energy Technology Data Exchange (ETDEWEB)

Di Maio, P.A., E-mail: dimaio@din.unipa.it [Dipartimento dell' Energia, Universita di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Arena, P.; Bongiovi, G. [Dipartimento dell' Energia, Universita di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Giammusso, R.; Micciche, G.; Tincani, A. [ENEA C. R. Brasimone, 40032 Camugnano, Bologna (Italy)

2012-08-15

Highlights: Black-Right-Pointing-Pointer IFMIF-EVEDA target assembly thermo-mechanical behavior has been investigated. Black-Right-Pointing-Pointer Finite element method has been followed and a commercial code has been used. Black-Right-Pointing-Pointer Nominal, design and pressure test steady state scenarios and start-up transient conditions have been investigated. Black-Right-Pointing-Pointer Steady state results have shown that back-plate yielding may occur only under the design scenario. Black-Right-Pointing-Pointer Transient analysis has indicated that TA start-up lasts for {approx}60 h. - Abstract: Within the framework of the IFMIF R and D program and in close cooperation with ENEA-Brasimone, at the Department of Energy of the University of Palermo a research campaign has been launched to investigate the thermo-mechanical behavior of the target assembly under both steady state and start-up transient conditions. A theoretical approach based on the finite element method (FEM) has been followed and a well-known commercial code has been adopted. A realistic 3D FEM model of the target assembly has been set-up and optimized by running a mesh independency analysis. A proper set of loads and boundary conditions, mainly concerned with radiation heat transfer between the target assembly external walls and the inner walls of its containment vessel, have been considered and the target assembly thermo-mechanical behavior under nominal, design and pressure test steady state scenarios and start-up transient conditions has been investigated. Results are herewith reported and discussed.

Competitive chiral induction in a 2D molecular assembly: Intrinsic chirality versus coadsorber-induced chirality.

Science.gov (United States)

Chen, Ting; Li, Shu-Ying; Wang, Dong; Wan, Li-Jun

2017-11-01

Noncovalently introducing stereogenic information is a promising approach to embed chirality in achiral molecular systems. However, the interplay of the noncovalently introduced chirality with the intrinsic chirality of molecules or molecular aggregations has rarely been addressed. We report a competitive chiral expression of the noncovalent interaction-mediated chirality induction and the intrinsic stereogenic center-controlled chirality induction in a two-dimensional (2D) molecular assembly at the liquid/solid interface. Two enantiomorphous honeycomb networks are formed by the coassembly of an achiral 5-(benzyloxy)isophthalic acid (BIC) derivative and 1-octanol at the liquid/solid interface. The preferential formation of the globally homochiral assembly can be achieved either by using the chiral analog of 1-octanol, ( S )-6-methyl-1-octanol, as a chiral coadsorber to induce chirality to the BIC assembly via noncovalent hydrogen bonding or by covalently linking a chiral center in the side chain of BIC. Both the chiral coadsorber and the intrinsically chiral BIC derivative can act as a chiral seeds to induce a preferred handedness in the assembly of the achiral BIC derivatives. Furthermore, the noncovalent interaction-mediated chirality induction can restrain or even overrule the manifestation of the intrinsic chirality of the BIC molecule and dominate the handedness of the 2D molecular coassembly. This study provides insight into the interplay of intrinsically chiral centers and external chiral coadsorbers in the chiral induction, transfer, and amplification processes of 2D molecular assembly.

Assembly Modulated by Particle Position and Shape: A New Concept in Self-Assembly

DEFF Research Database (Denmark)

Tavacoli, Joe W; Heuvingh, Julien; Du Roure, Olivia

2017-01-01

In this communication we outline how the bespoke arrangements and design of micron-sized superparamagnetic shapes provide levers to modulate their assembly under homogeneous magnetic fields. We label this new approach, 'assembly modulated by particle position and shape' (APPS). Specifically, using...... rectangular lattices of superparamagnetic micron-sized cuboids, we construct distinct microstructures by adjusting lattice pitch and angle of array with respect to a magnetic field. Broadly, we find two modes of assembly: (1) immediate 2D jamming of the cuboids as they rotate to align with the applied field...... (rotation-induced jamming) and (2) aggregation via translation after their full alignment (dipole-dipole assembly). The boundary between these two assembly pathways is independent on field strength being solely a function of the cuboid's dimensions, lattice pitch, and array angle with respect to field...

Fabrication and quality assurance of some important components and sub-assemblies for Prototype Fast Breeder Reactor (PFBR) project

International Nuclear Information System (INIS)

Dutta, N.G.; More, S.S.

2010-01-01

Bharatiya Nabhikiya Vidyut Nigam (BHAVINI) is engaged in construction of 500 MWe prototype fast breeder reactor (PFBR) at Kalpakkam, Chennai. In this very important and prestigious national programmed M/s Kay Bouvet Engg. Pvt. Ltd. (M/s KBEPL) Satara is contributing in a major way by supplying many important sub-assemblies. M/s KBEPL is engaged in manufacturing, quality assurance and supply of many subassemblies of PFBR like under water trolley (UWT), shielding door, container and container storage rack (CSR), vessel in fuel transfer cell (FTC), personnel air lock (PAL), emergency air lock (EAL) and material air lock (MAL), absorber rod drive mechanism (ARDM) flask assembly and carriage in MAL etc. Two partition doors and four nos. of embedded parts (SS 304L) have already been supplied to Bhavini. The paper deals with manufacturing and Q.A. activities being carried out for supply of these important assemblies to PFBR projects. (author)

Block copolymer assisted self-assembly of nanoparticles into Langmuir–Blodgett films: Effect of polymer concentration

International Nuclear Information System (INIS)

Martín-García, Beatriz; Velázquez, M. Mercedes

2013-01-01

We propose to use the self-assembly ability of a block copolymer to obtain CdSe quantum dots (QDs) structures of different morphology. The methodology proposed consist in transferring mixed Langmuir monolayers of QDs and the polymer poly (styrene-co-maleic anhydride) partial 2 buthoxy ethyl ester cumene terminated, PS-MA-BEE onto mica by the Langmuir–Blodgett (LB) methodology. The morphology of the LB films was analyzed by AFM and TEM measurements. Our results show that it is possible to modulate the self-assembly process by modifying the composition of the mixed Langmuir monolayer precursor of the LB film. The different morphologies are interpreted according to two different dewetting mechanisms, growth of holes and spinodal-like dewetting. The growth of holes dewetting process is driven by gravitatory effects and was observed for LB films obtained by transferring Langmuir monolayer of the smallest elasticity values in which the polymer is in brush conformation. The spinodal dewetting mechanism prevailed when the Langmuir monolayer presents the highest elasticity values. - Graphical abstract: Display Omitted - Highlights: • Effect of the surface composition on the LB films architecture. • QDs/polymer LB films morphology interpreted in terms of dewetting mechanism. • The dewetting mechanism depends on the Langmuir monolayer state

Block copolymer assisted self-assembly of nanoparticles into Langmuir–Blodgett films: Effect of polymer concentration

Energy Technology Data Exchange (ETDEWEB)

Martín-García, Beatriz; Velázquez, M. Mercedes, E-mail: mvsal@usal.es

2013-08-15

We propose to use the self-assembly ability of a block copolymer to obtain CdSe quantum dots (QDs) structures of different morphology. The methodology proposed consist in transferring mixed Langmuir monolayers of QDs and the polymer poly (styrene-co-maleic anhydride) partial 2 buthoxy ethyl ester cumene terminated, PS-MA-BEE onto mica by the Langmuir–Blodgett (LB) methodology. The morphology of the LB films was analyzed by AFM and TEM measurements. Our results show that it is possible to modulate the self-assembly process by modifying the composition of the mixed Langmuir monolayer precursor of the LB film. The different morphologies are interpreted according to two different dewetting mechanisms, growth of holes and spinodal-like dewetting. The growth of holes dewetting process is driven by gravitatory effects and was observed for LB films obtained by transferring Langmuir monolayer of the smallest elasticity values in which the polymer is in brush conformation. The spinodal dewetting mechanism prevailed when the Langmuir monolayer presents the highest elasticity values. - Graphical abstract: Display Omitted - Highlights: • Effect of the surface composition on the LB films architecture. • QDs/polymer LB films morphology interpreted in terms of dewetting mechanism. • The dewetting mechanism depends on the Langmuir monolayer state.

Tunneling nanotube (TNT)-mediated neuron-to neuron transfer of pathological Tau protein assemblies

OpenAIRE

TARDIVEL , Meryem; Bégard , Séverine; Bousset , Luc; Dujardin , Simon; Coens , Audrey; Melki , Ronald; Buée , Luc; Colin , Morvane

2016-01-01

A given cell makes exchanges with its neighbors through a variety of means ranging from diffusible factors to vesicles. Cells use also tunneling nanotubes (TNTs), filamentous-actin-containing membranous structures that bridge and connect cells. First described in immune cells, TNTs facilitate HIV-1 transfer and are found in various cell types, including neurons. We show that the microtubule-associated protein Tau, a key player in Alzheimer?s disease, is a bona fide constituent of TNTs. This i...

Dynamic behaviour of diagnostic assemblies

International Nuclear Information System (INIS)

Pecinka, L.

1980-01-01

The methodology is shown of calculating the frequency spectrum of a diagnostic assembly. The oscillations of the assembly as a whole, of a fuel rod bundle, the assembly jacket and of the individual rods in the bundle were considered. The manufacture is suggested of a model assembly which would be used for testing forced vibrations using an experimental water loop. (M.S.)

Selecting Operations for Assembler Encoding

Directory of Open Access Journals (Sweden)

Tomasz Praczyk

2010-04-01

Full Text Available Assembler Encoding is a neuro-evolutionary method in which a neural network is represented in the form of a simple program called Assembler Encoding Program. The task of the program is to create the so-called Network Definition Matrix which maintains all the information necessary to construct the network. To generate Assembler Encoding Programs and the subsequent neural networks evolutionary techniques are used.
The performance of Assembler Encoding strongly depends on operations used in Assembler Encoding Programs. To select the most effective operations, experiments in the optimization and the predator-prey problem were carried out. In the experiments, Assembler Encoding Programs equipped with different types of operations were tested. The results of the tests are presented at the end of the paper.

Flashback resistant pre-mixer assembly

Science.gov (United States)

Laster, Walter R [Oviedo, FL; Gambacorta, Domenico [Oviedo, FL

2012-02-14

A pre-mixer assembly associated with a fuel supply system for mixing of air and fuel upstream from a main combustion zone in a gas turbine engine. The pre-mixer assembly includes a swirler assembly disposed about a fuel injector of the fuel supply system and a pre-mixer transition member. The swirler assembly includes a forward end defining an air inlet and an opposed aft end. The pre-mixer transition member has a forward end affixed to the aft end of the swirler assembly and an opposed aft end defining an outlet of the pre-mixer assembly. The aft end of the pre-mixer transition member is spaced from a base plate such that a gap is formed between the aft end of the pre-mixer transition member and the base plate for permitting a flow of purge air therethrough to increase a velocity of the air/fuel mixture exiting the pre-mixer assembly.

Nuclear reactor fuel assembly

International Nuclear Information System (INIS)

Sasaki, Y.; Tashima, J.

1975-01-01

A description is given of nuclear reactor fuel assemblies arranged in the form of a lattice wherein there is attached to the interface of one of two adjacent fuel assemblies a plate spring having a concave portion curved toward said interface and to the interface of the other fuel assembly a plate spring having a convex portion curved away from said interface

Probing long-lived dark excitons in self-assembled quantum dots

DEFF Research Database (Denmark)

Johansen, Jeppe; Julsgaard, Brian; Stobbe, Søren

2010-01-01

Long-lived dark exciton states are formed in self-assembled quantum dots due to the combination of the angular momentum of electrons and holes. The lifetime of dark excitons are determined by spin-flip processes that transfer dark excitons into radiative bright excitons. We employ time......-resolved spontaneous emission measurements in a modified local density of optical states to unambiguously record the spin-flip rate. Pronounced variations in the spin-flip rate with the quantum dot emission energy are observed demonstrating that the exciton storage time can be extended by controlling the quantum dot......, which illustrates the important role of interfaces for quantum dot based nanophotonic structures....

Development of tritium technology at the Tritium Systems Test Assembly

International Nuclear Information System (INIS)

Anderson, J.L.; Bartlit, J.R.

1982-01-01

The Tritium Systems Test Assembly (TSTA) at the Los Alamos National Laboratory is dedicated to the development, demonstration, and interfacing of technologies related to the deuterium-tritium fuel cycle for large scale fusion reactor systems starting with the Fusion Engineering Device (FED) or the International Tokamak Reactor (INTOR). This paper briefly describes the fuel cycle and safety systems at TSTA including the Vacuum Facility, Fuel Cleanup, Isotope Separation, Transfer Pumping, Emergency Tritium Cleanup, Tritium Waste Treatment, Tritium Monitoring, Data Acquisition and Control, Emergency Power and Gas Analysis systems. Discussed in further detail is the experimental program proposed for the startup and testing of these systems

Design of the ITER Tokamak Assembly Tools

International Nuclear Information System (INIS)

Park, Hyunki; Her, Namil; Kim, Byungchul; Im, Kihak; Jung, Kijung; Lee, Jaehyuk; Im, Kisuk

2006-01-01

ITER (International Thermonuclear Experimental Reactor) Procurement allocation among the seven Parties, EU, JA, CN, IN , KO, RF and US had been decided in Dec. 2005. ITER Tokamak assembly tools is one of the nine components allocated to Korea for the construction of the ITER. Assembly tools except measurement and common tools are supplied to assemble the ITER Tokamak and classified into 9 groups according to components to be assembled. Among the 9 groups of assembly tools, large-sized Sector Sub-assembly Tools and Sector Assembly Tools are used at the first stage of ITER Tokamak construction and need to be designed faster than seven other assembly tools. ITER IT (International Team) proposed Korea to accomplish ITA (ITER Transitional Arrangements) Task on detailed design, manufacturing feasibility and contract specification of specific, large sized tools such as Upending Tool, Lifting Tool, Sector Sub-assembly Tool and Sector Assembly Tool in Oct. 2004. Based on the concept design by ITER IT, Korea carried out ITA Task on detailed design of large-sized and specific Sector Sub-assembly and Sector Assembly Tools until Mar. 2006. The Sector Sub-assembly Tools mainly consist of the Upending, Lifting, Vacuum Vessel Support and Bracing, and Sector Sub-assembly Tool, among which the design of three tools are herein. The Sector Assembly Tools mainly consist of the Toroidal Field (TF) Gravity Support Assembly, Sector In-pit Assembly, TF Coil Assembly, Vacuum Vessel (VV) Welding and Vacuum Vessel Thermal Shield (TS) Assembly Tool, among which the design of Sector In-pit Assembly Tool is described herein

Judgement on the data for fuel assembly outlet temperatures of WWER fuel assemblies in power reactors based on measurements with experimental fuel assemblies

International Nuclear Information System (INIS)

Krause, F.

1986-01-01

In the period from 1980 to 1985, in the Rheinsberg nuclear power plant experimental fuel assemblies were used on lattices at the periphery of the core. These particular fuel assemblies dispose of an extensive in-core instrumentation with different sensors. Besides this, they are fit out with a device to systematically thottle the coolant flow. The large power gradient present at the core position of the experimental fuel assembly causes a temperature profile along the fuel assemblies which is well provable at the measuring points of the outlet temperature. Along the direction of flow this temperature profile in the coolant degrades only slowly. This effect is to be taken into account when measuring the fuel assembly outlet temperature of WWER fuel assemblies. Besides this, the results of the measurements hinted both at a γ-heating of the temperature measuring points and at tolerances in the calculation of the micro power density distribution. (author)

Fuel assemblies

International Nuclear Information System (INIS)

Nagano, Mamoru; Yoshioka, Ritsuo

1983-01-01

Purpose: To effectively utilize nuclear fuels by increasing the reactivity of a fuel assembly and reduce the concentration at the central region thereof upon completion of the burning. Constitution: A fuel assembly is bisected into a central region and a peripheral region by disposing an inner channel box within a channel box. The flow rate of coolants passing through the central region is made greater than that in the peripheral region. The concentration of uranium 235 of the fuel rods in the central region is made higher. In such a structure, since the moderating effect in the central region is improved, the reactivity of the fuel assembly is increased and the uranium concentration in the central region upon completion of the burning can be reduced, fuel economy and effective utilization of uranium can be attained. (Kamimura, M.)

Fuel assembly

International Nuclear Information System (INIS)

Nakatsuka, Masafumi; Matsuzuka, Ryuji.

1976-01-01

Object: To provide a fuel assembly which can decrease pressure loss of coolant to uniform temperature. Structure: A sectional area of a flow passage in the vicinity of an inner peripheral surface of a wrapper tube is limited over the entire length to prevent the temperature of a fuel element in the outermost peripheral portion from being excessively decreased to thereby flatten temperature distribution. To this end, a plurality of pincture-frame-like sheet metals constituting a spacer for supporting a fuel assembly, which has a plurality of fuel elements planted lengthwise and in given spaced relation within the wrapper tube, is disposed in longitudinal grooves and in stacked fashion to form a substantially honeycomb-like space in cross section. The fuel elements are inserted and supported in the space to form a fuel assembly. (Kamimura, M.)

Welding facilities for NPP assembling

International Nuclear Information System (INIS)

Rojtenberg, S.S.

1987-01-01

Recommendations concerning the choice of equipment for welding in pre-assembling work shops, in the enlarging assembling shops and at the assembling site, are given. Advanced production automatic welders and semiautomatic machines, applied during the NPP equipment assembling as well as automatic machines specially produced for welding the main reactor components and pipelines are described. Automatic and semiautomatic machine and manual welding post supply sources are considered

Laser-induced forward transfer (LIFT) of congruent voxels

Energy Technology Data Exchange (ETDEWEB)

Piqué, Alberto, E-mail: pique@nrl.navy.mil [Materials Science and Technology Division, Code 6364, Naval Research Laboratory, Washington, DC 20375 (United States); Kim, Heungsoo; Auyeung, Raymond C.Y.; Beniam, Iyoel [Materials Science and Technology Division, Code 6364, Naval Research Laboratory, Washington, DC 20375 (United States); Breckenfeld, Eric [National Research Council Fellow at the Naval Research Laboratory, Washington, DC 20375 (United States)

2016-06-30

Highlights: • Laser-induced forward transfer (LIFT) is demonstrated with high viscosity Ag nanopaste. • Under the right conditions (viscosity and fluence) the transfer of congruent voxels was achieved. • For viscosities under 100 Pa s, congruent voxel transfer of silver nano-suspensions is only possible under a very narrow range of conditions. • For viscosities over 100 Pa s, congruent voxel transfer of silver nano-pastes works over a wider range of fluences, donor substrate thickness, gap distances and voxel areas. • The laser transfer of congruent voxels can be used for printing electronic patterns in particular interconnects. - Abstract: Laser-induced forward transfer (LIFT) of functional materials offers unique advantages and capabilities for the rapid prototyping of electronic, optical and sensor elements. The use of LIFT for printing high viscosity metallic nano-inks and nano-pastes can be optimized for the transfer of voxels congruent with the shape of the laser pulse, forming thin film-like structures non-lithographically. These processes are capable of printing patterns with excellent lateral resolution and thickness uniformity typically found in 3-dimensional stacked assemblies, MEMS-like structures and free-standing interconnects. However, in order to achieve congruent voxel transfer with LIFT, the particle size and viscosity of the ink or paste suspensions must be adjusted to minimize variations due to wetting and drying effects. When LIFT is carried out with high-viscosity nano-suspensions, the printed voxel size and shape become controllable parameters, allowing the printing of thin-film like structures whose shape is determined by the spatial distribution of the laser pulse. The result is a new level of parallelization beyond current serial direct-write processes whereby the geometry of each printed voxel can be optimized according to the pattern design. This work shows how LIFT of congruent voxels can be applied to the fabrication of 2D

Laser-induced forward transfer (LIFT) of congruent voxels

International Nuclear Information System (INIS)

Piqué, Alberto; Kim, Heungsoo; Auyeung, Raymond C.Y.; Beniam, Iyoel; Breckenfeld, Eric

2016-01-01

Highlights: • Laser-induced forward transfer (LIFT) is demonstrated with high viscosity Ag nanopaste. • Under the right conditions (viscosity and fluence) the transfer of congruent voxels was achieved. • For viscosities under 100 Pa s, congruent voxel transfer of silver nano-suspensions is only possible under a very narrow range of conditions. • For viscosities over 100 Pa s, congruent voxel transfer of silver nano-pastes works over a wider range of fluences, donor substrate thickness, gap distances and voxel areas. • The laser transfer of congruent voxels can be used for printing electronic patterns in particular interconnects. - Abstract: Laser-induced forward transfer (LIFT) of functional materials offers unique advantages and capabilities for the rapid prototyping of electronic, optical and sensor elements. The use of LIFT for printing high viscosity metallic nano-inks and nano-pastes can be optimized for the transfer of voxels congruent with the shape of the laser pulse, forming thin film-like structures non-lithographically. These processes are capable of printing patterns with excellent lateral resolution and thickness uniformity typically found in 3-dimensional stacked assemblies, MEMS-like structures and free-standing interconnects. However, in order to achieve congruent voxel transfer with LIFT, the particle size and viscosity of the ink or paste suspensions must be adjusted to minimize variations due to wetting and drying effects. When LIFT is carried out with high-viscosity nano-suspensions, the printed voxel size and shape become controllable parameters, allowing the printing of thin-film like structures whose shape is determined by the spatial distribution of the laser pulse. The result is a new level of parallelization beyond current serial direct-write processes whereby the geometry of each printed voxel can be optimized according to the pattern design. This work shows how LIFT of congruent voxels can be applied to the fabrication of 2D

Energy transfer between a nanosystem and its host fluid: A multiscale factorization approach

Science.gov (United States)

Sereda, Yuriy V.; Espinosa-Duran, John M.; Ortoleva, Peter J.

2014-02-01

Energy transfer between a macromolecule or supramolecular assembly and a host medium is considered from the perspective of Newton's equations and Lie-Trotter factorization. The development starts by demonstrating that the energy of the molecule evolves slowly relative to the time scale of atomic collisions-vibrations. The energy is envisioned to be a coarse-grained variable that coevolves with the rapidly fluctuating atomistic degrees of freedom. Lie-Trotter factorization is shown to be a natural framework for expressing this coevolution. A mathematical formalism and workflow for efficient multiscale simulation of energy transfer is presented. Lactoferrin and human papilloma virus capsid-like structure are used for validation.

Energy transfer between a nanosystem and its host fluid: A multiscale factorization approach

Energy Technology Data Exchange (ETDEWEB)

Sereda, Yuriy V.; Espinosa-Duran, John M.; Ortoleva, Peter J., E-mail: ortoleva@indiana.edu [Center for Cell and Virus Theory, Department of Chemistry, Indiana University, 800 E. Kirkwood Ave, Bloomington, Indiana 47405 (United States)

2014-02-21

Energy transfer between a macromolecule or supramolecular assembly and a host medium is considered from the perspective of Newton's equations and Lie-Trotter factorization. The development starts by demonstrating that the energy of the molecule evolves slowly relative to the time scale of atomic collisions-vibrations. The energy is envisioned to be a coarse-grained variable that coevolves with the rapidly fluctuating atomistic degrees of freedom. Lie-Trotter factorization is shown to be a natural framework for expressing this coevolution. A mathematical formalism and workflow for efficient multiscale simulation of energy transfer is presented. Lactoferrin and human papilloma virus capsid-like structure are used for validation.

Energy transfer between a nanosystem and its host fluid: A multiscale factorization approach

International Nuclear Information System (INIS)

Sereda, Yuriy V.; Espinosa-Duran, John M.; Ortoleva, Peter J.

2014-01-01

Energy transfer between a macromolecule or supramolecular assembly and a host medium is considered from the perspective of Newton's equations and Lie-Trotter factorization. The development starts by demonstrating that the energy of the molecule evolves slowly relative to the time scale of atomic collisions-vibrations. The energy is envisioned to be a coarse-grained variable that coevolves with the rapidly fluctuating atomistic degrees of freedom. Lie-Trotter factorization is shown to be a natural framework for expressing this coevolution. A mathematical formalism and workflow for efficient multiscale simulation of energy transfer is presented. Lactoferrin and human papilloma virus capsid-like structure are used for validation

Laser-induced forward transfer (LIFT) of congruent voxels

Science.gov (United States)

Piqué, Alberto; Kim, Heungsoo; Auyeung, Raymond C. Y.; Beniam, Iyoel; Breckenfeld, Eric

2016-06-01

Laser-induced forward transfer (LIFT) of functional materials offers unique advantages and capabilities for the rapid prototyping of electronic, optical and sensor elements. The use of LIFT for printing high viscosity metallic nano-inks and nano-pastes can be optimized for the transfer of voxels congruent with the shape of the laser pulse, forming thin film-like structures non-lithographically. These processes are capable of printing patterns with excellent lateral resolution and thickness uniformity typically found in 3-dimensional stacked assemblies, MEMS-like structures and free-standing interconnects. However, in order to achieve congruent voxel transfer with LIFT, the particle size and viscosity of the ink or paste suspensions must be adjusted to minimize variations due to wetting and drying effects. When LIFT is carried out with high-viscosity nano-suspensions, the printed voxel size and shape become controllable parameters, allowing the printing of thin-film like structures whose shape is determined by the spatial distribution of the laser pulse. The result is a new level of parallelization beyond current serial direct-write processes whereby the geometry of each printed voxel can be optimized according to the pattern design. This work shows how LIFT of congruent voxels can be applied to the fabrication of 2D and 3D microstructures by adjusting the viscosity of the nano-suspension and laser transfer parameters.

Composite turbine bucket assembly

Science.gov (United States)

Liotta, Gary Charles; Garcia-Crespo, Andres

2014-05-20

A composite turbine blade assembly includes a ceramic blade including an airfoil portion, a shank portion and an attachment portion; and a transition assembly adapted to attach the ceramic blade to a turbine disk or rotor, the transition assembly including first and second transition components clamped together, trapping said ceramic airfoil therebetween. Interior surfaces of the first and second transition portions are formed to mate with the shank portion and the attachment portion of the ceramic blade, and exterior surfaces of said first and second transition components are formed to include an attachment feature enabling the transition assembly to be attached to the turbine rotor or disk.