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Sample records for addition-fragmentation chain transfer

  1. 'Green' reversible addition-fragmentation chain-transfer (RAFT) polymerization

    Science.gov (United States)

    Semsarilar, Mona; Perrier, Sébastien

    2010-10-01

    Reversible addition-fragmentation chain-transfer (RAFT) polymerization has revolutionized the field of polymer synthesis as a versatile tool for the production of complex polymeric architectures. As for all chemical processes, research and development in RAFT have to focus on the design and application of chemical products and processes that have a minimum environmental impact, and follow the principles of 'green' chemistry. In this Review, we summarize some of the green features of the RAFT process, and review the recent advances in the production of degradable polymers obtained from RAFT polymerization. Its use to modify biodegradable and renewable inorganic and organic materials to yield more functional products with enhanced applications is also covered. RAFT is a promising candidate for answering both the increasing need of modern society to employ highly functional polymeric materials and the global requirements for developing sustainable chemicals and processes.

  2. The reversible addition-fragmentation chain transfer (RAFT) miniemulsion polymerization of vinyl acetate mediated by xanthate

    Institute of Scientific and Technical Information of China (English)

    Bo Jiang; Qing Hua Zhang; Xiao Li Zhan; Feng Qiu Chen

    2009-01-01

    The reversible addition-fragmentation chain transfer (RAFT) miniemulsion polymerization of vinyl acetate (VAt) mediated by methyl (methoxycarbonothioyl) sulfanyl acetate (MMSA) was carried out. The results showed that polymerizations initiated by AIBN and KPS proceeded in a controlled way. The RAFT miniemulsion polymerization of VAc initiated by KPS showed the shorter inhibition period, higher propagation rate coefficient and final conversion than those in experiment initiated by AIBN. When the monomer conversion reached 25%, the polydispersity index (PDI) of polymer became broad, which was related to chain transfer reaction in RAFT miniemulsion of VAc.

  3. Evaluation of the clenbuterol imprinted monolithic column prepared by reversible addition-fragmentation chain transfer polymerization

    Institute of Scientific and Technical Information of China (English)

    Mamat Turson; Xiao Lei Zhuang; Hui Na Liu; Ping Jiang; Xiang Chao Dong

    2009-01-01

    To make more homogenous organic monolithic structure,reversible addition-fragmentation chain transfer(RAFT)process was employed in the synthesis of the clenbuterol imprinted polymer.In the synthesis,the influence of synthetic conditions on the polymer structure and separation efficiency was studied.The result demonstrated that the imprinted columns prepared with RAFT process have higher column efficiency and selectivity than the columns prepared with conventional polymerization in the present study,which may result from the higher surface area,smaller pore size and the narrower globule size distribution in their structures.The result indicated that RAFT polymerization provided better conditions for the clenbuterol imprinted monolithic polymer preparation.

  4. Polymer-grafted lignin surfactants prepared via reversible addition-fragmentation chain-transfer polymerization.

    Science.gov (United States)

    Gupta, Chetali; Washburn, Newell R

    2014-08-12

    Kraft lignin grafted with hydrophilic polymers has been prepared using reversible addition-fragmentation chain-transfer (RAFT) polymerization and investigated for use as a surfactant. In this preliminary study, polyacrylamide and poly(acrylic acid) were grafted from a lignin RAFT macroinitiator at average initiator site densities estimated to be 2 per particle and 17 per particle. The target degrees of polymerization were 50 and 100, but analysis of cleaved polyacrylamide was consistent with a higher average molecular weight, suggesting not all sites were able to participate in the polymerization. All materials were readily soluble in water, and dynamic light scattering data indicate polymer-grafted lignin coexisted in isolated and aggregated forms in aqueous media. The characteristic size was 15-20 nm at low concentrations, and aggregation appeared to be a stronger function of degree of polymerization than graft density. These species were surface active, reducing the surface tension to as low as 60 dyn/cm at 1 mg/mL, and a greater decrease was observed than for polymer-grafted silica nanoparticles, suggesting that the lignin core was also surface active. While these lignin surfactants were soluble in water, they were not soluble in hexanes. Thus, it was unexpected that water-in-oil emulsions formed in all surfactant compositions and solvent ratios tested, with average droplet sizes of 10-20 μm. However, although polymer-grafted lignin has structural features similar to nanoparticles used in Pickering emulsions, its interfacial behavior was qualitatively different. While at air-water interfaces, the hydrophilic grafts promote effective reductions in surface tension, we hypothesize that the low grafting density in these lignin surfactants favors partitioning into the hexanes side of the oil-water interface because collapsed conformations of the polymer grafts improve interfacial coverage and reduce water-hexanes interactions. We propose that polymer-grafted lignin

  5. Functionalization of vertically aligned carbon nanotubes with polystyrene via surface initiated reversible addition fragmentation chain transfer polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Macdonald, Thomas; Gibson, Christopher T.; Constantopoulos, Kristina; Shapter, Joseph G. [Flinders Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA, 5001 (Australia); Ellis, Amanda V., E-mail: amanda.ellis@flinders.edu.au [Flinders Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA, 5001 (Australia)

    2012-01-15

    Here we demonstrate the covalent attachment of vertically aligned (VA) acid treated single-walled carbon nanotubes (SWCNTs) onto a silicon substrate via dicyclohexylcarbodiimide (DCC) coupling chemistry. Subsequently, the pendant carboxyl moieties on the sidewalls of the VA-SWCNTs were derivatized to acyl chlorides, and then finally to bis(dithioester) moieties using a magnesium chloride dithiobenzoate salt. The bis(dithioester) moieties were then successfully shown to act as a chain transfer agent (CTA) in the reversible addition fragmentation chain transfer (RAFT) polymerization of styrene in a surface initiated 'grafting-from' process from the VA-SWCNT surface. Atomic force microscopy (AFM) verified vertical alignment of the SWCNTs and the maintenance thereof throughout the synthesis process. Finally, Raman scattering spectroscopy and AFM confirmed polystyrene functionalization.

  6. Early career: Templating of liquid crystal microstructures by reversible addition-fragmentation chain transfer polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Heinen, Jennifer M. (O' Donnell) [Iowa State Univ., Ames, IA (United States)

    2014-12-31

    This research has shown that the microstructure of self-assembled copolymers can be decoupled from the polymer chemistry. The simplest polymer architecture, linear block copolymers, is valuable for a broad range of applications, including adhesives and coatings, medical devices, electronics and energy storage, because these block copolymers reproducibly self-assemble into microphase separated nanoscale domains. Unfortunately, the self-assembled microstructure is tuned by polymer composition, thus limiting the potential to simultaneously optimize chemical, mechanical, and transport properties for desired applications. To this end, much work was been put into manipulating block copolymer self-assembly independently of polymer composition. These efforts have included the use of additives or solvents to alter polymer chain conformation, the addition of a third monomer to produce ABC triblock terpolymers, architectures with mixed blocks, such as tapered/gradient polymers, and the synthesis of other nonlinear molecular architectures. This work has shown that the microstructures formed by linear ABC terpolymers can be altered by controlling the architecture of the polymer molecules at a constant monomer composition, so that the microstructure is tuned independently from the chemical properties.

  7. Study on the performance of polycarboxylate-based superplasticizers synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization

    Science.gov (United States)

    Yu, Binbin; Zeng, Zhong; Ren, Qinyu; Chen, Yang; Liang, Mei; Zou, Huawei

    2016-09-01

    A series of block type polycarboxylate-based superplasticizers (PCs) with different molecular architectures were synthesized with macromonomer butenyl alkylene polyoxyethylene-polyoxypropylene ether (BAPP) and acrylic acid (AA) by reversible addition-fragmentation chain transfer (RAFT) polymerization. Fourier-Transformed Infrared (FTIR) Spectroscopy and dynamic light scattering (DLS) were applied to investigate the PCs' molecular structure. The dispersion capacity of the PCs in cement were also measured, and the results showed that the polycarboxylic dispersing agents prepared by this method were suitable for portlant cement. It was found that the PCs could affect the hydration process, which was performed through retarding the generation of ettringite in the hydrated product. Our studies with X-ray diffraction (XRD), scanning electron microscopy (SEM) and compressive strength measurement of hydrated production were all supporting this conclusion.

  8. Scale-up of the Reversible Addition-Fragmentation Chain Transfer (RAFT Polymerization Using Continuous Flow Processing

    Directory of Open Access Journals (Sweden)

    Nenad Micic

    2014-01-01

    Full Text Available A controlled radical polymerization process using the Reversible Addition-Fragmentation Chain Transfer (RAFT approach was scaled up by a factor of 100 from a small laboratory scale of 5 mL to a preparative scale of 500 mL, using batch and continuous flow processing. The batch polymerizations were carried out in a series of different glass vessels, using either magnetic or overhead stirring, and different modes of heating: Microwave irradiation or conductive heating in an oil bath. The continuous process was conducted in a prototype tubular flow reactor, consisting of 6 mm ID stainless steel tubing, fitted with static mixers. Both reactor types were tested for polymerizations of the acid functional monomers acrylic acid and 2-acrylamido-2-methylpropane-1-sulfonic acid in water at 80 °C with reaction times of 30 to 40 min. By monitoring the temperature during the exothermic polymerization process, it was observed that the type and size of reactor had a significant influence on the temperature profile of the reaction.

  9. 3种三硫酯RAFT剂的制备及表征%Synthesis and characterization of three trithiocarbonates rversible addition-fragmentation chain transfer agents

    Institute of Scientific and Technical Information of China (English)

    周应学

    2012-01-01

    The preparation of reversible addition-fragmentation chain transfer (RAFT) agents is the base of polymer architectures via RAFT polymerization. Three trithiocarbonate RAFT agents were syneth-sized in strong alkaline conditions with dodecyl mercaptan and carbon disulfide by phase transfer catalysis tetrapropyl-ammonium bromide and tricaprylylmethyl-ammonium chloride (Aliquot 336),respectively. The products were characterized by *H桸MR,13 C-nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared (FTIR), the element analysis and'differential scanning calorimetry (DSC). The results show that the proofs of product are the target products. The phase transfer mechanism is presented and clarified the reaction processes. The RAFT agents could be used in bulk or solution polymerization, or modified to prepare macroinitiators.%在强碱条件下,分别以四丙基溴化铵和三辛基甲基氯化铵(Aliquot 336)为相转移催化剂,十二烷基硫醇与二硫化碳反应,制备了3种三硫酯型可逆加成-断裂链转移剂(RAFT).以1H-NMR、13C-NMR、傅里叶变换红外(FTIR),元素分析和差失扫描量热(DSC)对产物进行表征.证明所得产物为目标物,所提产物可应用于本体或溶液体系的RAFT聚合.

  10. Surface molecular imprinting onto fluorescein-coated magnetic nanoparticlesvia reversible addition fragmentation chain transfer polymerization: A facile three-in-one system for recognition and separation of endocrine disrupting chemicals

    Science.gov (United States)

    Li, Ying; Dong, Cunku; Chu, Jia; Qi, Jingyao; Li, Xin

    2011-01-01

    In this study, we present a general protocol for the making of surface-imprinted magnetic fluorescence beads viareversible addition-fragmentation chain transfer polymerization. The resulting composites were characterized by X-ray diffraction analysis, transmission electron microscopy, scanning electron microscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy, and energy dispersive spectroscopy. The as-synthesized beads exhibited homogeneous polymer films (thickness of about 5.7 nm), spherical shape, high fluorescence intensity and magnetic property (Magnetization (Ms) = 3.67 emu g-1). The hybrids bind the original template 17β-estradiol with an appreciable selectivity over structurally related compounds. In addition, the resulting hybrids performed without obvious deterioration after five repeated cycles. This study therefore demonstrates the potential of molecularly imprinted polymers for the recognition and separation of endocrine disrupting chemicals.In this study, we present a general protocol for the making of surface-imprinted magnetic fluorescence beads viareversible addition-fragmentation chain transfer polymerization. The resulting composites were characterized by X-ray diffraction analysis, transmission electron microscopy, scanning electron microscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy, and energy dispersive spectroscopy. The as-synthesized beads exhibited homogeneous polymer films (thickness of about 5.7 nm), spherical shape, high fluorescence intensity and magnetic property (Magnetization (Ms) = 3.67 emu g-1). The hybrids bind the original template 17β-estradiol with an appreciable selectivity over structurally related compounds. In addition, the resulting hybrids performed without obvious deterioration after five repeated cycles. This study therefore demonstrates the potential of molecularly imprinted polymers for the recognition and separation of endocrine disrupting chemicals. Electronic

  11. An ion-imprinted functionalized SBA-15 adsorbent synthesized by surface imprinting technique via reversible addition-fragmentation chain transfer polymerization for selective removal of Ce(III) from aqueous solution.

    Science.gov (United States)

    Meng, Minjia; Meng, Xiangguo; Liu, Yan; Liu, Zhanchao; Han, Juan; Wang, Yun; Luo, Min; Chen, Rui; Ni, Liang; Yan, Yongsheng

    2014-08-15

    A novel Ce(III) ion-imprinted polymer (Ce(III)-IIP) has been prepared by surface imprinting technique with reversible addition-fragmentation chain transfer (RAFT) polymerization based on support matrix of SBA-15. The prepared adsorbent is characterized by FT-IR, XRD, SEM, TEM, nitrogen adsorption-desorption, GPC, and TGA. The results suggest that the surface imprinted polymer synthesized by RAFT is a thin layer. For adsorption experiments, Ce(III)-IIP is investigated to remove Ce(III) by column study at different flow rates, initial metal ion concentrations, and adsorption temperature. The dynamic kinetics analyses reveal that the overall adsorption process is successfully fitted with the pseudo-first-order kinetic model and the equilibrium time was 60 min. Meanwhile, the experimental data is in good agreement with Thomas model. Ce(III)-IIP has the excellent selectivity and regenerate property. Meanwhile, the proposed method has been successfully applied in the removal of Ce(III) in natural water samples with satisfactory results. All the results suggest that Ce(III)-IIP could be used as an excellent adsorbent for efficient removal of Ce(III) from aqueous solution.

  12. 相转移催化制备3种三硫酯可逆加成-断裂链转移剂%Synthesis of Three Trithiocarbonates Rversible Addition-Fragmentation Chain Transfer Agents by Phase Transfer Catalysis Reaction

    Institute of Scientific and Technical Information of China (English)

    周应学

    2013-01-01

    Phase transfer catalysis is widely used in synthesis of compounds. In this paper,using tetra-propylammonium bromide and tri-caprylylmethylammonium chloride (Aliquot 336) as phase transfer catalysts , three trithiocarbonate reversible addition−fragmentation chain transfer (RAFT) agents were respectively synethsized from dodecyl mercaptan and carbon disulfide in strong alkaline condition. The products were characterized by 1H, 13C-nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared (FTIR), the element analysis and differential scanning calorimetry (DSC). The results show that the products are the target product. Then the phase transfer mechanism was discussed. The RAFT agents after the modification can be used in emulsion, bulk or solution polymerization.%  相转移催化在有机合成中应用广泛。分别以四丙基溴化铵和三辛基甲基氯化铵(Aliquot 336)为相转移催化剂,以十二烷基硫醇与二硫化碳,在强碱条件下,制备了3种三硫酯型可逆加成-断裂链转移(RAFT)剂。以1H,13C-NMR,傅里叶变换红外(FTIR),元素分析和差失扫描量热(DSC)对产物进行了表征。证明所得产物为目标物。提出了相转移催化机理。合成的三硫酯 RAFT 可以通过改性,应用于乳液,本体或溶液的可逆加成-断裂链转移聚合。

  13. 可逆加成-断裂链转移自由基聚合与点击化学相结合在制备特殊结构聚合物中的应用%Progress in Synthesizing Special Structure Polymers via Combination of Reversible Addition-Fragmentation Chain Transfer Polymerization with Click Chemistry

    Institute of Scientific and Technical Information of China (English)

    陈鹏宇; 曹亚

    2011-01-01

    可逆加成一断裂链转移(RAFT)聚合作为一种新型活性自由基聚合方法,由于其具有单体适用面广、聚合条件温和、不受聚合方法的限制等优点,已经成为聚合物分子设计的有效手段之一.点击化学(Click chaemistry)是近几年发展起来的一种快速合成的新方法,是指选用易得原料,通过可靠、高效而又具有选择性的化学反应来实现碳杂原子连接,低成本、快速合成大量新化合物的一种强大且实用的合成方法.两者相结合可以制备多种具有特殊结构的聚合物,这一联用技术也越来越引起研究者们的重视.本文综述了近几年来采用RAFT和点击化学方法结合制备特殊结构聚合物的研究进展.%As a new method of living radical polymerization, reversible addition-fragmentation chain transfer (RAFT) polymerization has a lot of advantages. It can apply to a wide range of monomers in a mild reaction condition. Besides, RAFT polymerization can proceed in bulk, solution, emulsion and suspension polymerization. So RAFT polymerization appears to be one of the most promising techniques of macromolecular design. Click chemistry develops in recent years and it is an approach through which large numbers of new compounds can be quickly synthesized by utilizing reliable, efficient and selective chemical reactions. The Combination of RAFT polymerization with click chemistry can be used to synthesize various special structure polymers, which induces more attention of many researchers. This review deals with recent progress in synthesizing special structure polymer via the combination of RAFT polymerization with click chemistry.

  14. Reversible Addition Fragmentation Chain Transfer (RAFT) Polymerization in Undergraduate Polymer Science Lab

    Science.gov (United States)

    Nguyen, T. L. U.; Bennet, Francesca; Stenzel, Martina H.; Barner-Kowollik, Christopher

    2008-01-01

    This 8-hour experiment (spread over two 4-hour sessions) is designed to equip students with essential skills in polymer synthesis, particularly in synthesizing polymers of well-defined molecular weight. The experiment involves the synthesis and characterization of poly(vinyl neodecanoate) via living free radical polymerization, specifically the…

  15. Electron Transfer Chain Catalysis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Electron-transfer chain (ETC) catalysis belongs to the family of chain reactions where the electron is the catalyst. The ETC mechanism could be initiated by chemical activation, electrochemistry, or photolysis. If this pathway is applied to the preparation of organometallic complexes, it utilizes the greatly enhanced reactivity of organometallic 17e and 19e radicals. The chemical propagation is followed by the cross electron-transfer while the electron-transfer step is also followed by the chemical propagation, creating a loop in which reactants are facilely transformed into products. Interestingly the overall reaction is without any net redox change.

  16. Electron Transfer Chain Catalysis

    Institute of Scientific and Technical Information of China (English)

    LIU; LingKang

    2001-01-01

    Electron-transfer chain (ETC) catalysis belongs to the family of chain reactions where the electron is the catalyst. The ETC mechanism could be initiated by chemical activation, electrochemistry, or photolysis. If this pathway is applied to the preparation of organometallic complexes, it utilizes the greatly enhanced reactivity of organometallic 17e and 19e radicals. The chemical propagation is followed by the cross electron-transfer while the electron-transfer step is also followed by the chemical propagation, creating a loop in which reactants are facilely transformed into products. Interestingly the overall reaction is without any net redox change.  ……

  17. RAFT Miniemulsion Polymerization of MMA with Cumyl Dithiobenzoate as Chain Transfer Agent

    Institute of Scientific and Technical Information of China (English)

    Tian Ying GUO; Dong Lin TANG; Jing Wei ZHU; Mou Dao SONG; Bang Hua ZHANG

    2006-01-01

    Reversible addition-fragmentation transfer (RAFT) miniemulsion polymerizations for PMMA with cumyl dithiobenzoate (CDB) as a chain transfer agent (CTA) has been carried out.Higher temperature made the polymerization much faster and the PDI remained below 1.20, when the temperature was upon 70 ℃.

  18. Superadiabatic quantum state transfer in spin chains

    Science.gov (United States)

    Agundez, R. R.; Hill, C. D.; Hollenberg, L. C. L.; Rogge, S.; Blaauboer, M.

    2017-01-01

    In this paper we propose a superadiabatic protocol where quantum state transfer can be achieved with arbitrarily high accuracy and minimal control across long spin chains with an odd number of spins. The quantum state transfer protocol only requires the control of the couplings between the qubits on the edge and the spin chain. We predict fidelities above 0.99 for an evolution of nanoseconds using typical spin-exchange coupling values of μ eV . Furthermore, by building a superadiabatic formalism on top of this protocol, we propose an effective superadiabatic protocol that retains the minimal control over the spin chain and further improves the fidelity.

  19. RAFT microemulsion polymerization with surface-active chain transfer agent

    Science.gov (United States)

    El-Hedok, Ibrahim Adnan

    The work described in this dissertation focuses on enhancing the polymer nanoparticle synthesis using RAFT (reversible-addition fragmentation chain transfer) in microemulsion polymerization in order to achieve predetermined molecular weight with narrow molecular weight polydispersity. The hypothesis is that the use of an amphiphilic chain transfer agent (surface-active CTA) will confine the CTA to the surface of the particle and thermodynamically favor partitioning of the CTA between micelles and particles throughout the polymerization. Thus, the CTA diffusion from micelles to polymer particles would be minimized and the breadth of the CTA per particle distribution would remain low. We report the successful improved synthesis of poly(butyl acrylate), poly(ethyl acrylate), and poly(styrene) nanoparticles using the RAFT microemulsion polymerization with surface-active CTA. The polymerization kinetics, polymer characteristics and latex size experimental data are presented. The data analysis indicates that the CTA remains partitioned between the micelles and particles by the end of the polymerization, as expected. We also report the synthesis of well-defined core/shell poly(styrene)/poly(butyl acrylate) nanoparticle, having polydispersity index value of 1.1, using semi-continuous microemulsion polymerization with the surface-active CTA. The surface-active CTA restricts the polymerization growth to the surface of the particle, which facilitates the formation of a shell block co-polymers with each subsequent second monomer addition instead of discrete homopolymers. This synthesis method can be used to create a wide range of core/shell polymer nanoparticles with well-defined morphology, given the right feeding conditions.

  20. Molecular Imprinting of Silica Nanoparticle Surfaces via Reversible Addition-Fragmentation Polymerization for Optical Biosensing Applications

    Science.gov (United States)

    Oluz, Zehra; Nayab, Sana; Kursun, Talya Tugana; Caykara, Tuncer; Yameen, Basit; Duran, Hatice

    Azo initiator modified surface of silica nanoparticles were coated via reversible addition-fragmentation polymerization (RAFT) of methacrylic acid and ethylene glycol dimethacrylate using 2-phenylprop 2-yl dithobenzoate as chain transfer agent. Using L-phenylalanine anilide as template during polymerization led molecularly imprinted nanoparticles. RAFT polymerization offers an efficient control of grafting process, while molecularly imprinted polymers shows enhanced capacity as sensor. L-phenylalanine anilide imprinted silica particles were characterized by X-Ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM). Performances of the particles were followed by surface plasmon resonance spectroscopy (SPR) after coating the final product on gold deposited glass substrate against four different analogous of analyte molecules: D-henylalanine anilide, L-tyrosine, L-tryptophan and L-phenylalanine. Characterizations indicated that silica particles coated with polymer layer do contain binding sites for L-phenylalanine anilide, and are highly selective for the molecule of interest. This project was supported by TUBITAK (Project No:112M804).

  1. Exciton Transfer Integrals Between Polymer Chains

    CERN Document Server

    Barford, W

    2007-01-01

    The line-dipole approximation for the evaluation of the exciton transfer integral, $J$, between conjugated polymer chains is rigorously justified. Using this approximation, as well as the plane-wave approximation for the exciton center-of-mass wavefunction, it is shown analytically that $J \\sim L$ when the chain lengths are smaller than the separation between them, or $J\\sim L^{-1}$ when the chain lengths are larger than their separation, where $L$ is the polymer length. Scaling relations are also obtained numerically for the more realistic standing-wave approximation for the exciton center-of-mass wavefunction, where it is found that for chain lengths larger than their separation $J \\sim L^{-1.8}$ or $J \\sim L^{-2}$, for parallel or collinear chains, respectively. These results have important implications for the photo-physics of conjugated polymers and self-assembled molecular systems, as the Davydov splitting in aggregates and the F\\"orster transfer rate for exciton migration decreases with chain lengths l...

  2. Synthesis and Characterization of a Novel Addition-Fragmentation Reactive Surfactant (TRANSURF) for Use in Free-Radical Emulsion Polymerizations.

    Science.gov (United States)

    Wilkinson, Terence S.; Boonstra, Armin; Montoya-Goñi, Amaia; van Es, Steven; Monteiro, Michael J.; German, Anton L.

    2001-05-01

    The synthesis and characterization of a new type of chain-transfer-active surfactant (i.e., TRANSURF) is reported. The compound was designed on the basis of the chemistry of macromers, which undergo free-radical chain-transfer addition-fragmentation reactions. In effect this allows incorporation of the surfactant molecule into the polymer backbone, and thus reduces the influence of surfactant migration during film formation. Surfactants of this type, containing two hydrophilic head groups, can have a marked influence on the polymer and latex properties (e.g., molecular weight distributions and particle size). Characterization of the physical properties of this surfactant was therefore carried out using surface tension, conductivity, and fluorescence techniques. Because of the surfactant's unusual "bolaform" (alpha, omega) (Zana, R., in "Structure-Performance Relationships in Surfactants" (K. Esumi and M. Ueno, Eds.), Surfactant Science Series 70, Dekker, New York, 1997) structure the micelle formation process has been found to be quite different from that of the conventional surfactant, sodium dodecyl sulfate (SDS). From the surface tension data a flat molecular conformation was evident at 1x10(-3) mol dm(-3) (131 Å(2) surface area), which we assumed to correspond to the low aggregation number of premicellar aggregates. There is evidence to suggest formation of a larger volume of the microdomains in these micelles compared to that in SDS. At higher TRANSURF concentrations, however, we find no clear indication of a switch to a "wicket"-type conformation, although such conformational changes cannot be ruled out. Copyright 2001 Academic Press.

  3. Facile Fabrication of Water Dispersible Latex Particles with Homogeneous or Chain-Segregated Surface from RAFT Polymerization Using a Mixture of Two Macromolecular Chain Transfer Agents.

    Science.gov (United States)

    Sun, Li; Hong, Liangzhi; Wang, Chaoyang

    2016-04-01

    Water dispersible latex particles with randomly mixed shells or chain segregated surface are synthesized from one-pot reversible addition-fragmentation chain transfer heterogeneous polymerization of benzyl methacrylate (BzMA) using a mixture of poly(glycerol monomethacrylate) (PGMA) and poly(2,3-bis(succinyloxy)propyl methacrylate) (PBSPMA) macromolecular chain transfer agents. In methanol, the two in situ synthesized PGMA-b-PBzMA and PBSPMA-b-PBzMA diblock copolymers coaggregate into spherical micelles, which contain PBzMA core and discrete PGMA and PBSPMA nanodomains on the shell. In contrast, in water-methanol mixture (V/V = 9/1), latex particles with homogeneous distribution of PGMA and PBSPMA polymer chains on the shell are obtained. The reasons leading to formation of latex particles with homogenous or chain-segregated surface are discussed, and polymerization kinetics and physical state of PBSPMA in methanol and water-methanol mixtures are ascribed. These polymeric micelles with patterned functional group on the surface are potentially important for application in supracolloidal hierarchical assemblies and catalysis.

  4. Free Radical Polymerization Based on Addition-Fragmentation Chain Transfer Mechanism%基于加成-断裂型链转移机理的自由基聚合反应

    Institute of Scientific and Technical Information of China (English)

    安粒; 惠嘉; 宋犇

    2011-01-01

    本文综述了自由基聚合链转移反应的机理及发展历程,着重概述了基于加成-断裂链转移机理的链转移剂在自由基聚合中的应用.主要的加成-断裂链转移剂类型包括乙烯基醚类,烯丙基硫代化合物、砜、卤化物、磷酸盐类,烯丙基过氧化物类以及硫代羰基类化合物.加成-断裂型链转移剂能够在自由基聚合中作为分子量调节剂,控制聚合物的分子量及分布,并能广泛用于常用单体中.该类链转移剂为制备末端功能化聚合物、嵌段聚合物提供了一种有效的途径,在印刷和包装用油墨、胶黏剂等高分子材料领域,有一定的应用前景.

  5. Quantum state transfer in a q-deformed chain

    Energy Technology Data Exchange (ETDEWEB)

    L' Innocente, Sonia [Dipartimento di Matematica ed Informatica, Universita di Camerino, 62032 Camerino (Italy); Lupo, Cosmo; Mancini, Stefano [Dipartimento di Fisica, Universita di Camerino, 62032 Camerino (Italy)], E-mail: sonia.linnocente@unicam.it, E-mail: cosmo.lupo@unicam.it, E-mail: stefano.mancini@unicam.it

    2009-11-27

    We investigate the quantum state transfer in a chain of particles satisfying the q-deformed oscillators algebra. This general algebraic setting includes the spin chain and the bosonic chain as limiting cases. We study conditions for perfect state transfer depending on the number of sites and excitations on the chain. They are formulated by means of irreducible representations of a quantum algebra realized through Jordan-Schwinger maps. Playing with deformation parameters, we can study the effects of nonlinear perturbations or interpolate between the spin and bosonic chains.

  6. Boundary-controlled spin chains for robust quantum state transfer

    CERN Document Server

    Zwick, Analia; Stolze, Joachim; Osenda, Omar

    2011-01-01

    Quantum state transfer in the presence of noise is one of the main challenges for building quantum computers. We compare the quantum state transfer properties for two classes of qubit chains under the influence of static randomness. In fully engineered chains all nearest-neighbor couplings are tuned in such a way that a single-qubit state can be transferred perfectly between the ends of the chain, while in boundary-controlled chains only the two couplings between the transmitting and receiving qubits and the remainder of the chain can be optimized. We study how the noise in the couplings affects the state transfer fidelity depending on the noise model and strength as well as the chain type and length. We show that the desired level of fidelity and transfer time are important factors in designing a chain. In particular we demonstrate that transfer efficiency comparable or better than that of the most robust engineered systems can also be reached in boundary-controlled chains without the demanding engineering o...

  7. Modelling proton transfer in water molecule chains

    CERN Document Server

    Korzhimanov, Artem; Shutova, Tatiana; Samuelsson, Goran

    2011-01-01

    The process of protons transport in molecular water chains is of fundamental interest for many biological systems. Although many features of such systems can be analyzed using large-scale computational modeling, other features are better understood in terms of simplified model problems. Here we have tested, analytically and numerically, a model describing the classical proton hopping process in molecular water chains. In order to capture the main features of the proton hopping process in such molecular chains, we use a simplified model for our analysis. In particular, our discrete model describes a 1D chain of water molecules situated in an external protein channel structure, and each water molecule is allowed to oscillate around its equilibrium point in this system, while the protons are allowed to move along the line of neighboring oxygen atoms. The occurrence and properties of nonlinear solitary transport structures, allowing for much faster proton transport, are discussed, and the possible implications of...

  8. Spin chains for robust state transfer: Modified boundary couplings versus completely engineered chains

    Science.gov (United States)

    Zwick, Analia; Álvarez, Gonzalo A.; Stolze, Joachim; Osenda, Omar

    2012-01-01

    Quantum state transfer in the presence of static disorder and noise is one of the main challenges in building quantum computers. We compare the quantum state transfer properties for two classes of qubit chains under the influence of static disorder. In fully engineered chains all nearest-neighbor couplings are tuned in such a way that a single-qubit state can be transferred perfectly between the ends of the chain, while in chains with modified boundaries only the two couplings between the transmitting and receiving qubits and the remainder of the chain can be optimized. We study how the disorder in the couplings affects the state transfer fidelity depending on the disorder model and strength as well as the chain type and length. We show that the desired level of fidelity and transfer time are important factors in designing a chain. In particular we demonstrate that transfer efficiency comparable or better than that of the most robust engineered systems can also be reached in chains with modified boundaries without the demanding engineering of a large number of couplings.

  9. Entanglement Transfer via XXZ Heisenberg chain with DM Interaction

    CERN Document Server

    Rafiee, Morteza; Mohammadi, Hamidreza; Mokhtari, Hossein

    2010-01-01

    The role of spin-orbit interaction, arises from the Dzyaloshinski-Moriya anisotropic antisymmetric interaction, on the entanglement transfer via an antiferromagnetic XXZ Heisenberg chain is investigated. From symmetrical point of view, the XXZ Hamiltonian with Dzyaloshinski-Moriya interaction can be replaced by a modified XXZ Hamiltonian which is defined by a new exchange coupling constant and rotated Pauli operators. The modified coupling constant and the angle of rotations are depend on the strength of Dzyaloshinski-Moriya interaction. In this paper we study the dynamical behavior of the entanglement propagation through a system which is consist of a pair of maximally entangled spins coupled to one end of the chain. The calculations are performed for the ground state and the thermal state of the chain, separately. In both cases the presence of this anisotropic interaction make our channel more efficient, such that the speed of transmission and the amount of the entanglement are improved as this interaction ...

  10. Quantum state transfer in a XX chain with impurities

    Energy Technology Data Exchange (ETDEWEB)

    Zwick, Analia; Osenda, Omar, E-mail: zwick@famaf.unc.edu.ar, E-mail: osenda@famaf.unc.edu.ar [Facultad de Matematica, AstronomIa y Fisica, Universidad Nacional de Cordoba and IFEG-CONICET, Ciudad Universitaria, X5016LAE, Cordoba (Argentina)

    2011-03-11

    One spin excitation states are involved in the transmission of quantum states and entanglement through a quantum spin chain, the localization properties of these states are crucial to achieve the transfer of information from one extreme of the chain to the other. We investigate the bipartite entanglement and localization of the one excitation states in a quantum XX chain with one impurity. The bipartite entanglement is obtained using the concurrence and the localization is analyzed using the inverse participation ratio (IPR). Changing the strength of the exchange coupling of the impurity allows us to control the number of localized or extended states. The analysis of the IPR allows us to identify scenarios where the transmission of quantum states or entanglement can be achieved with a high degree of fidelity. In particular, we identify a regime where the transmission of quantum states between the extremes of the chain is executed in a short transmission time {approx}N/2, where N is the number of spins in the chain, and with a large fidelity.

  11. Robust Quantum State Transfer in Random Unpolarized Spin Chains

    CERN Document Server

    Yao, Norman Y; Gorshkov, Alexey V; Gong, Zhe-Xuan; Zhai, Alex; Duan, L -M; Lukin, Mikhail D

    2010-01-01

    We propose and analyze a new approach for quantum state transfer between remote spin qubits. Specifically, we demonstrate that coherent quantum coupling between remote qubits can be achieved via certain classes of random, unpolarized spin chains. Our method is robust to coupling strength disorder and does not require manipulation or control over individual spins. In principle, it can be used to attain perfect state transfer over arbitrarily long range via purely Hamiltonian evolution and may be particularly applicable in a solid-state quantum information processor. As an example, we demonstrate that it can be used to attain strong coherent coupling between Nitrogen-Vacancy centers separated by micrometer distances at room temperature. Realistic imperfections and decoherence effects are analyzed.

  12. Robust quantum state transfer in random unpolarized spin chains.

    Science.gov (United States)

    Yao, N Y; Jiang, L; Gorshkov, A V; Gong, Z-X; Zhai, A; Duan, L-M; Lukin, M D

    2011-01-28

    We propose and analyze a new approach for quantum state transfer between remote spin qubits. Specifically, we demonstrate that coherent quantum coupling between remote qubits can be achieved via certain classes of random, unpolarized (infinite temperature) spin chains. Our method is robust to coupling-strength disorder and does not require manipulation or control over individual spins. In principle, it can be used to attain perfect state transfer over an arbitrarily long range via purely Hamiltonian evolution and may be particularly applicable in a solid-state quantum information processor. As an example, we demonstrate that it can be used to attain strong coherent coupling between nitrogen-vacancy centers separated by micrometer distances at room temperature. Realistic imperfections and decoherence effects are analyzed.

  13. Evolutionary conservation of heavy chain protein transfer between glycosaminoglycans.

    Science.gov (United States)

    Sanggaard, Kristian W; Hansen, Lone; Scavenius, Carsten; Wisniewski, Hans-Georg; Kristensen, Torsten; Thøgersen, Ida B; Enghild, Jan J

    2010-04-01

    The bikunin proteins are composed of heavy chains (HCs) covalently linked to a chondroitin sulfate chain originating from Ser-10 of bikunin. Tumor necrosis factor stimulated gene-6 protein (TSG-6)/heavy chain 2 (HC2) cleaves this unique cross-link and transfers the HCs to hyaluronan and other glycosaminoglycans via a covalent HC*TSG-6 intermediate. In the present study, we have investigated if this reaction is evolutionary conserved based on the hypothesis that it is of fundamental importance. The results revealed that plasma/serum samples from mammal, bird, and reptile were able to form TSG-6 complexes suggesting the presence of proteins with the same function as the human bikunin proteins. To substantiate this, the complex forming protein from Gallus gallus (Gg) plasma was purified and identified as a Gg homolog of human HC2*bikunin. In addition, Gg pre-alpha-inhibitor and smaller amount of high molecular weight forms composed of bikunin and two HCs were purified. Like the human bikunin proteins, the purified Gg proteins were all stabilized by a protein-glycosaminoglycan-protein cross-link, i.e. the HCs were covalently attached to a chondroitin sulfate originating from bikunin. Furthermore, the complex formed between Gg HC2*bikunin and human TSG-6 appeared to be identical to that of the human proteins. Akin to human, Gg HC2 was further transferred to hyaluronan when present, and when incubated in vitro, Gg pre-alpha-inhibitor and TSG-6, failed to form the intermediate covalent complex, essential for HC transfer. Significantly, Gg HC2, analogous to human HC2, promoted complex formation between human HC3 and human TSG-6, substantiating the evolutionary conservation of these interactions. The present study demonstrates that the unique interactions between bikunin proteins, glycosaminoglycans, and TSG-6 are evolutionary conserved, emphasizing the physiological importance of the TSG-6/HC2-mediated HC-transfer reaction. In addition, the data show that the evolution of

  14. Sudden Chain Energy Transfer Events in Vibrated Granular Media

    Science.gov (United States)

    Rivas, Nicolás; Ponce, Suomi; Soto, Rodrigo; Cordero, Patricio; Mujica, Nicolás; Risso, Dino; Gallet, Basille

    2012-02-01

    In a mixture of two species of grains of equal size but different mass, placed in a vertically vibrated shallow box, there is spontaneous segregation. Once the system is at least partly segregated and clusters of the heavy particles have formed, there are sudden peaks of the horizontal kinetic energy of the heavy particles, that is otherwise small. Together with the energy peaks the clusters rapidly expand and the segregation is partially lost. The process repeats once segregation has taken place again, either randomly or with some regularity in time depending on the experimental or numerical parameters. An explanation for these events is provided based on the existence of a fixed point for an isolated particle bouncing with only vertical motion. The horizontal energy peaks occur when the energy stored in the vertical motion is partly transferred into horizontal energy through a chain reaction of collisions between heavy particles.

  15. QSRR correlation of free-radical polymerization chain-transfer constants for styrene.

    Science.gov (United States)

    Ignatz-Hoover, F; Petrukhin, R; Karelson, M; Katritzky, A R

    2001-01-01

    Quantitative structure-reactivity relationships (QSRR) are deduced for kinetic chain-transfer constants for 90 agents on styrene polymerization at 60 degrees C. Three- and five-parameter correlations were obtained with R2 of 0.725 and 0.818, respectively. The descriptors involved in the correlations are consistent with the proposed mechanism of the chain-transfer reactions.

  16. Organic cleanliness of the Mars Science Laboratory sample transfer chain.

    Science.gov (United States)

    Blakkolb, B; Logan, C; Jandura, L; Okon, A; Anderson, M; Katz, I; Aveni, G; Brown, K; Chung, S; Ferraro, N; Limonadi, D; Melko, J; Mennella, J; Yavrouian, A

    2014-07-01

    One of the primary science goals of the Mars Science Laboratory (MSL) Rover, Curiosity, is the detection of organics in Mars rock and regolith. To achieve this, the Curiosity rover includes a robotic sampling system that acquires rock and regolith samples and delivers it to the Sample Analysis at Mars (SAM) instrument on board the rover. In order to provide confidence that any significant organics detection result was Martian and not terrestrial in origin, a requirement was levied on the flight system (i.e., all sources minus the SAM instrument) to impart no more than 36 parts per billion (ppb by weight) of total reduced carbon terrestrial contamination to any sample transferred to the SAM instrument. This very clean level was achieved by a combination of a rigorous contamination control program on the project, and then using the first collected samples for a "dilution cleaning" campaign of the sample chain prior to delivering a sample to the SAM instrument. Direct cleanliness assays of the sample-contacting and other Flight System surfaces during pre-launch processing were used as inputs to determine the number of dilution cleaning samples needed once on Mars, to enable delivery of suitably clean samples to the SAM experiment. Taking into account contaminant redistribution during launch thorough landing of the MSL on Mars, the amount of residue present on the sampling hardware prior to the time of first dilution cleaning sample acquisition was estimated to be 60 ng/cm(2) on exposed outer surfaces of the sampling hardware and 20 ng/cm(2) on internal sample contacting surfaces; residues consisting mainly of aliphatic hydrocarbons and esters. After three dilution cleaning samples, estimated in-sample contamination level for the first regolith sample delivered to the SAM instrument at the Gale Crater "Rocknest" site was bounded at ≤10 ppb total organic carbon. A Project decision to forego ejecting the dilution cleaning sample and instead transfer the first drill

  17. Implementation of State Transfer Hamiltonians in Spin Chains with Magnetic Resonance Techniques

    OpenAIRE

    Cappellaro, Paola

    2014-01-01

    Nuclear spin systems and magnetic resonance techniques have provided a fertile platform for experimental investigation of quantum state transfer in spin chains. From the first observation of polarization transfer, predating the formal definition of quantum state transfer, to the realization of state transfer simulations in small molecules and in larger solid-state spin systems, the experiments have drawn on the strengths of nuclear magnetic resonance (NMR), in particular on its long history o...

  18. Radiative transfer calculated from a Markov chain formalism

    Science.gov (United States)

    Esposito, L. W.; House, L. L.

    1978-01-01

    The theory of Markov chains is used to formulate the radiative transport problem in a general way by modeling the successive interactions of a photon as a stochastic process. Under the minimal requirement that the stochastic process is a Markov chain, the determination of the diffuse reflection or transmission from a scattering atmosphere is equivalent to the solution of a system of linear equations. This treatment is mathematically equivalent to, and thus has many of the advantages of, Monte Carlo methods, but can be considerably more rapid than Monte Carlo algorithms for numerical calculations in particular applications. We have verified the speed and accuracy of this formalism for the standard problem of finding the intensity of scattered light from a homogeneous plane-parallel atmosphere with an arbitrary phase function for scattering. Accurate results over a wide range of parameters were obtained with computation times comparable to those of a standard 'doubling' routine. The generality of this formalism thus allows fast, direct solutions to problems that were previously soluble only by Monte Carlo methods. Some comparisons are made with respect to integral equation methods.

  19. Bioaccumulation and food chain transfer of corrosion products from radioactive stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Young, J.S.

    1986-07-01

    Two sets of experiments were conducted to determine if corrosion products from radioactive Type 347 stainless steel could be biologically transferred from sediment through a marine food chain, and whether corrosion products dissolved in seawater could be bioaccumulated and then eliminated. Corrosion products containing /sup 60/Co and /sup 63/Ni from the radioactive stainless steel were introduced into marine sediments. Infaunal polychaete worms exposed to these sediments bioaccumulated the radionuclides. The feeding of these worms to shrimp and fish resulted in a trophic transfer of the radioactive products across a one-step food chain. The magnitude of the transfers are described in terms of transfer factors. Dissolved corrosion products as measured by the radionuclides were also bioaccumulated by shrimp and fish concentrating more than fish. Concentration factors were calculated.

  20. Copper transfer and influence on a marine food chain

    Energy Technology Data Exchange (ETDEWEB)

    Edding, M.; Tala, F. [Universidad Catolica del Norte, Coquimbo (Chile)

    1996-12-31

    Copper is an essential element, required for normal growth by all plants and animals; and a regular constituent in the environment (Lewis and Cave 1982; Lewis 1994). This heavy metal is an essential micronutrient that at higher concentrations can be deleterious to algae and other aquatic biota (Chang and Sibley 1993). Copper toxicity to algae depends upon the individual species, their physiological and environmental conditions, and the chemical forms of metal in the medium (Sunda and Gullard 1976). When copper is accumulated by phytoplankton it can be transferred and may produce toxic effects on zooplankton (Wikfors and Ukeles 1982). Different species of microalgae present different capacities of resistance to copper. Cyanophyceae pre-cultured in a Cu-enriched medium (635 {mu}gCu{center_dot}L{sup {minus}1}) showed an EC{sub 50} that could reach 318 {mu}gCu{center_dot}L{sup {minus}1} for Plectonema radiosum and 339 {mu}gCu{center_dot}L{sup {minus}1} in Phormidium sp. (Takamura et al. 1990). Scenedesmus, Selenastrum and Chlorella were reported able to accumulate copper and other metal ions with an efficiency of 67-98% (Brady et al. 1994). Also, Dunaliella resisted concentrations form 0.38 mgCu{center_dot}L{sup {minus}1} (D. minuta) up to 50.8 mgCu{center_dot}L{sup {minus}1} (D. acidophila), depending on the pH of the medium (Grimmler et al. 1991). One the microalgae are copper-enriched, the copper that is part of the cell can be transferred to the surrounding water and to its predator producing uncertain effects. This study observed the effect of copper on the growth of Dunaliella tertiolecta and Isochrysis galbana that are currently used as food for hatchery-grown scallop larvae (Argopecten purpuratus). We observed the path of copper form the water column into the microalgal cell and the effect of copper-enriched food on the scallop larvae. 16 refs., 3 figs., 2 tabs.

  1. Passive transfer of maternal immunity in the dromedary (Camelus dromedarius), involvement of heavy chain antibodies.

    Science.gov (United States)

    Salhi, Imed; Bessalah, Salma; Mbarek, Sonia Ben; Chniter, Mohamed; Seddik, Mabrouk-Mouldi; Khorchani, Touhami; Hammadi, Mohamed

    2015-03-01

    In many mammalian species, newborns are agammaglobulinemic; thus, colostrum and milk are the main sources of early protective antibodies. These antibodies are produced in the mother's serum and transferred to mammalian glands a few days before parturition. Here, we have studied the transfer of immunity from a she-camel immunized with human serum albumin (HSA) to her calf via colostrum and milk. Our results show that HSA-specific antibodies are produced in the mother's serum and are subsequently transferred to her colostrum. These specific antibodies are then transferred by suckling to the calf. The calf serum did not contain HSA-reactive antibodies at parturition and before the first feed, after suckling, a rise in reactivity was observed peaking at 24 h postpartum. The involvement of heavy chain antibodies (HCAbs) in the process of immunity transfer was also examined, and it was found that they were also transferred from the colostrum to the calf serum like conventional antibodies.

  2. Chaining direct memory access data transfer operations for compute nodes in a parallel computer

    Science.gov (United States)

    Archer, Charles J.; Blocksome, Michael A.

    2010-09-28

    Methods, systems, and products are disclosed for chaining DMA data transfer operations for compute nodes in a parallel computer that include: receiving, by an origin DMA engine on an origin node in an origin injection FIFO buffer for the origin DMA engine, a RGET data descriptor specifying a DMA transfer operation data descriptor on the origin node and a second RGET data descriptor on the origin node, the second RGET data descriptor specifying a target RGET data descriptor on the target node, the target RGET data descriptor specifying an additional DMA transfer operation data descriptor on the origin node; creating, by the origin DMA engine, an RGET packet in dependence upon the RGET data descriptor, the RGET packet containing the DMA transfer operation data descriptor and the second RGET data descriptor; and transferring, by the origin DMA engine to a target DMA engine on the target node, the RGET packet.

  3. 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 demonstrat...... 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....

  4. Light, nutrients, and food-chain length constrain planktonic energy transfer efficiency across multiple trophic levels.

    Science.gov (United States)

    Dickman, Elizabeth M; Newell, Jennifer M; González, María J; Vanni, Michael J

    2008-11-25

    The efficiency of energy transfer through food chains [food chain efficiency (FCE)] is an important ecosystem function. It has been hypothesized that FCE across multiple trophic levels is constrained by the efficiency at which herbivores use plant energy, which depends on plant nutritional quality. Furthermore, the number of trophic levels may also constrain FCE, because herbivores are less efficient in using plant production when they are constrained by carnivores. These hypotheses have not been tested experimentally in food chains with 3 or more trophic levels. In a field experiment manipulating light, nutrients, and food-chain length, we show that FCE is constrained by algal food quality and food-chain length. FCE across 3 trophic levels (phytoplankton to carnivorous fish) was highest under low light and high nutrients, where algal quality was best as indicated by taxonomic composition and nutrient stoichiometry. In 3-level systems, FCE was constrained by the efficiency at which both herbivores and carnivores converted food into production; a strong nutrient effect on carnivore efficiency suggests a carryover effect of algal quality across 3 trophic levels. Energy transfer efficiency from algae to herbivores was also higher in 2-level systems (without carnivores) than in 3-level systems. Our results support the hypothesis that FCE is strongly constrained by light, nutrients, and food-chain length and suggest that carryover effects across multiple trophic levels are important. Because many environmental perturbations affect light, nutrients, and food-chain length, and many ecological services are mediated by FCE, it will be important to apply these findings to various ecosystem types.

  5. Removal of phase transfer agent leads to restricted dynamics of alkyl chains in monolayer protected clusters

    Indian Academy of Sciences (India)

    V R Rajeev Kumar; R Mukhopadhyay; T Pradeep

    2008-11-01

    The effect of phase transfer agent in the dynamics of monolayer protected gold nanoparticles has been investigated by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies. The experiments were performed with octadecane thiol and dodecane thiol protected gold nanoparticles. The materials prepared were characterized by UV-Visible spectroscopy, transmission electron microscopy and IR spectroscopy. Repeated purification of the monolayer protected gold clusters made the alkyl chains defect-free. Such effects are reflected in the infrared spectra. Interdigitation of the monolayers that followed the purification leads to alkyl chains with limited mobility. This was reflected in 13C and 1H NMR linewidths. The NMR measurements indicate that the removal of phase transfer agent affects the dynamics of isolated clusters and those with interdigitated monolayers in different ways.

  6. A chiroptical switch based on supramolecular chirality transfer through alkyl chain entanglement and dynamic covalent bonding.

    Science.gov (United States)

    Lv, Kai; Qin, Long; Wang, Xiufeng; Zhang, Li; Liu, Minghua

    2013-12-14

    Chirality transfer is an interesting phenomenon in Nature, which represents an important step to understand the evolution of chiral bias and the amplification of the chirality. In this paper, we report the chirality transfer via the entanglement of the alkyl chains between chiral gelator molecules and achiral amphiphilic Schiff base. We have found that although an achiral Schiff base amphiphile could not form organogels in any kind of organic solvents, it formed co-organogels when mixed with a chiral gelator molecule. Interestingly, the chirality of the gelator molecules was transferred to the Schiff base chromophore in the mixed co-gels and there was a maximum mixing ratio for the chirality transfer. Furthermore, the supramolecular chirality was also produced based on a dynamic covalent chemistry of an imine formed by the reaction between an aldehyde and an amine. Such a covalent bond of imine was formed reversibly depending on the pH variation. When the covalent bond was formed the chirality transfer occurred, when it was destroyed, the transfer stopped. Thus, a supramolecular chiroptical switch is obtained based on supramolecular chirality transfer and dynamic covalent chemistry.

  7. Ultrafast energy transfer from rigid, branched side-chains into a conjugated, alternating copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Graham B.; Rolczynski, Brian S.; Linkin, Alexander; McGillicuddy, Ryan D.; Engel, Gregory S., E-mail: gsengel@uchicago.edu [Department of Chemistry, The James Franck Institute, Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637 (United States); Lundin, Pamela M. [Department of Chemical Engineering, Stanford University, Stauffer III, 381 North-South Mall, Stanford, California 94305 (United States); A. R. Smith Department of Chemistry, Appalachian State University, 417 CAP Building, 525 Rivers Street, Boone, North Carolina 28608 (United States); Bao, Zhenan [Department of Chemical Engineering, Stanford University, Stauffer III, 381 North-South Mall, Stanford, California 94305 (United States)

    2014-01-21

    We present the synthesis and characterization of a benzodithiophene/thiophene alternating copolymer decorated with rigid, singly branched pendant side chains. We characterize exciton migration and recombination dynamics in these molecules in tetrahydrofuran solution, using a combination of static and time-resolved spectroscopies. As control experiments, we also measure electronic relaxation dynamics in isolated molecular analogues of both the side chain and polymer moieties. We employ semi-empirical and time-dependent density functional theory calculations to show that photoexcitation of the decorated copolymer using 395 nm laser pulses results in excited states primarily localized on the pendant side chains. We use ultrafast transient absorption spectroscopy to show that excitations are transferred to the polymer backbone faster than the instrumental response function, ∼250 fs.

  8. Modelling of radiocesium transfer in the lichen-reindeer/caribou-wolf food chain

    Directory of Open Access Journals (Sweden)

    D. F. Holleman

    1990-09-01

    Full Text Available The environmental contaminate radiocesium (cesium-137 has been shown to be of value as a marker in food selection and intake studies. Its greatest potential value as a food marker is in the subarctic/arctic regions, particularly in the lichen to reindeer/caribou to wolf food chain. A kinetic model describing the movement of radiocesium through the food chain has been developed using the SAAM computer program and is presented here. The program has been written so that the various paramenters affecting the transfer of radiocesium in the food chain can be altered more realistically to describe the system being modeled. The values of the parameters as given in this example are realistic for interior Alaska, however caution should be exercised in the application of the present results to regions that may be vastly different from the Alaskan interior without first evaluating the parameters and assumptions of the model.

  9. A model for the chain-to-plane charge transfer in YBa2Cu3O6+x

    Institute of Scientific and Technical Information of China (English)

    V.M.Matic; N.Dj.Lazarov; M.Milic

    2012-01-01

    A model for the chain-to-plane charge transfer is proposed to account for the two plateaus,at 60 K and at 90 K,of the Tc(x) characteristics of the YBa2Cu3O6+x high-Tc superconductor.It is assumed that the number of holes transferred from a CuO chain of length l to two nearby CuO2 sheets is proportional to l (that is,to the number of oxygen atoms in the chain),if the chain length is greater than,or equal to,a certain critical chain length,lcr,that is required to trigger the charge transfer process.No holes are assumed to have been transferred from chains of length l < lcr.The calculated Tc(x) dependence is found to be in excellent agreement with the experimentally reported Tc(x).The critical chain length parameter is estimated to be equal to lcr =11 (eleven oxygen atoms in a chain),which is a greater value than that obtained in the previously proposed model for the chain-to plane charge transfer (lcr =4).The results obtained out of the proposed model are briefly discussed.

  10. Revealing various coupling of electron transfer and proton pumping in mitochondrial respiratory chain.

    Science.gov (United States)

    Sun, Fei; Zhou, Qiangjun; Pang, Xiaoyun; Xu, Yingzhi; Rao, Zihe

    2013-08-01

    Cellular respiration is the process that releases energy from food and supplies energy for life processes. The mitochondrial respiratory chain is the final and most important step for cellular respiration and is located on the inner membrane of mitochondrion and comprises four large trans-membrane protein complexes (respiratory chain Complexes I, II, III and IV) as well as ubiquinone between Complexes I/II and III and cytochrome c between Complexes III and IV. The function of mitochondrial respiratory chain is biological oxidation by transferring electrons from NADH and succinate to oxygen and then generating proton gradient across the inner membrane. Such proton gradient is utilized by ATP synthase (ATPase, also called as Complex V) to produce energy molecules ATP. Structural studies of mitochondrial respiratory membrane protein complexes are important to understand the mechanism of electron transfer and the redox-coupled proton translocation across the inner membrane. Here, according to the time line, we reviewed the great achievements on structural studies of mitochondrial respiratory complexes in the past twenty years as well as the recent research progresses on the structures of mitochondrial respiratory supra-complexes.

  11. Inverting OII 83.4 nm Dayglow Profiles Using Markov Chain Radiative Transfer

    CERN Document Server

    Geddes, George; Finn, Susanna C; Cook, Timothy; Chakrabarti, Supriya

    2016-01-01

    Emission profiles of the resonantly scattered OII~83.4~nm triplet can in principle be used to estimate \\(\\mathrm{O}^+\\) density profiles in the F2 region of the ionosphere. Given the emission source profile, solution of this inverse problem is possible, but requires significant computation. The traditional Feautrier solution to the radiative transfer problem requires many iterations to converge, making it time-consuming to compute. A Markov chain approach to the problem produces similar results by directly constructing a matrix that maps the source emission rate to an effective emission rate which includes scattering to all orders. The Markov chain approach presented here yields faster results and therefore can be used to perform the \\(\\mathrm{O}^+\\) density retrieval with higher resolution than would otherwise be possible.

  12. Inverting OII 83.4 nm dayglow profiles using Markov chain radiative transfer

    Science.gov (United States)

    Geddes, George; Douglas, Ewan; Finn, Susanna C.; Cook, Timothy; Chakrabarti, Supriya

    2016-11-01

    Emission profiles of the resonantly scattered OII 83.4 nm triplet can in principle be used to estimate O+ density profiles in the F2 region of the ionosphere. Given the emission source profile, solution of this inverse problem is possible but requires significant computation. The traditional Feautrier solution to the radiative transfer problem requires many iterations to converge, making it time consuming to compute. A Markov chain approach to the problem produces similar results by directly constructing a matrix that maps the source emission rate to an effective emission rate which includes scattering to all orders. The Markov chain approach presented here yields faster results and therefore can be used to perform the O+ density retrieval with higher resolution than would otherwise be possible.

  13. Polonium ({sup 210}Po) and lead ({sup 210}Pb) in marine organisms and their transfer in marine food chains

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Fernando P., E-mail: carvalho@itn.p [Instituto Tecnologico e Nuclear, Departamento de Proteccao Radiologica e Seguranca Nuclear, E.N. 10, 2686-953 Sacavem (Portugal)

    2011-05-15

    The determination of {sup 210}Po and {sup 210}Pb was performed in marine organisms from the seashore to abyssal depths, encompassing a plethora of species from the microscopic plankton to the sperm whale. Concentrations of those radionuclides ranged from low values of about 5 x 10{sup -1} Bq kg{sup -1} (wet wt.) in jellyfish, to very high values of about of 3 x 10{sup 4} Bq kg{sup -1} (wet wt.) in the gut walls of sardines, with a common pattern of {sup 210}Po > {sup 210}Pb.These radionuclides are primarily absorbed from water and concentrated by phyto- and microzooplankton, and then are transferred to the next trophic level along marine food chains. Investigation in epipelagic, mesopelagic, bathypelagic and abyssobenthic organisms revealed that {sup 210}Po is transferred in the marine food webs with transfer factors ranging from 0.1 to 0.7, and numerically similar to those of the energy transfer in the marine food chains. As {sup 210}Po preferentially binds to amino acids and proteins, its transfer in food chains likely traces protein transfer and, thus, {sup 210}Po transfer factors are similar to ecotrophic coefficients. {sup 210}Pb is transferred less efficiently in marine food chains and this contributes to increased {sup 210}Po:{sup 210}Pb activity ratios in some trophic levels.

  14. Entanglement Transfer and Periodic Sudden Death Phenomenon in Two Parallel 1D Spin Chains of Quantum Spin Network

    Institute of Scientific and Technical Information of China (English)

    WANG Zhao-Ming; SHAO Bin; ZOU Jian

    2007-01-01

    We investigate the entanglement transfer in two parallel 1D spin chains of a quantum spin network,and show that the perfect entanglement transfer can be realized at some special times.In addition,the so-called 'sudden death' phenomenon of entanglement is found in the spin network system.

  15. Metabolic transistor strategy for controlling electron transfer chain activity in Escherichia coli.

    Science.gov (United States)

    Wu, Hui; Tuli, Leepika; Bennett, George N; San, Ka-Yiu

    2015-03-01

    A novel strategy to finely control a large metabolic flux by using a "metabolic transistor" approach was established. In this approach a small change in the level or availability of an essential component for the process is controlled by adding a competitive reaction that affects a precursor or an intermediate in its biosynthetic pathway. The change of the basal level of the essential component, considered as a base current in a transistor, has a large effect on the flux through the major pathway. In this way, the fine-tuning of a large flux can be accomplished. The "metabolic transistor" strategy was applied to control electron transfer chain function by manipulation of the quinone synthesis pathway in Escherichia coli. The achievement of a theoretical yield of lactate production under aerobic conditions via this strategy upon manipulation of the biosynthetic pathway of the key participant, ubiquinone-8 (Q8), in an E. coli strain provides an in vivo, genetically tunable means to control the activity of the electron transfer chain and manipulate the production of reduced products while limiting consumption of oxygen to a defined amount.

  16. Carrier transfer in vertically stacked quantum ring-quantum dot chains

    Energy Technology Data Exchange (ETDEWEB)

    Mazur, Yu. I., E-mail: ymazur@uark.edu; Dorogan, V. G.; Benamara, M.; Salamo, G. J. [Arkansas Institute for Nanoscale Materials Science and Engineering, University of Arkansas, Fayetteville, Arkansas 72701 (United States); Lopes-Oliveira, V.; Lopez-Richard, V.; Teodoro, M. D.; Marques, G. E. [Departamento de Fisica, Universidade Federal de São Carlos, 13565-905 São Carlos, São Paulo (Brazil); Souza, L. D. de [Departamento de Fisica, Universidade Federal de São Carlos, 13565-905 São Carlos, São Paulo (Brazil); Arkansas Institute for Nanoscale Materials Science and Engineering, University of Arkansas, Fayetteville, Arkansas 72701 (United States); Wu, J.; Wang, Z. M. [State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu (China); Tarasov, G. G. [Institute of Semiconductor Physics, National Academy of Sciences, pr. Nauki 45, Kiev 03028 (Ukraine); Marega, E. [Instituto de Fisica de São Carlos, Universidade de São Paulo, 13.566-590 São Carlos, São Paulo (Brazil)

    2015-04-21

    The interplay between structural properties and charge transfer in self-assembled quantum ring (QR) chains grown by molecular beam epitaxy on top of an InGaAs/GaAs quantum dot (QD) superlattice template is analyzed and characterized. The QDs and QRs are vertically stacked and laterally coupled as well as aligned within each layer due to the strain field distributions that governs the ordering. The strong interdot coupling influences the carrier transfer both along as well as between chains in the ring layer and dot template structures. A qualitative contrast between different dynamic models has been developed. By combining temperature and excitation intensity effects, the tuning of the photoluminescence gain for either the QR or the QD mode is attained. The information obtained here about relaxation parameters, energy scheme, interlayer and interdot coupling resulting in creation of 1D structures is very important for the usage of such specific QR–QD systems for applied purposes such as lasing, detection, and energy-harvesting technology of future solar panels.

  17. Carrier transfer in vertically stacked quantum ring-quantum dot chains

    Science.gov (United States)

    Mazur, Yu. I.; Lopes-Oliveira, V.; de Souza, L. D.; Lopez-Richard, V.; Teodoro, M. D.; Dorogan, V. G.; Benamara, M.; Wu, J.; Tarasov, G. G.; Marega, E.; Wang, Z. M.; Marques, G. E.; Salamo, G. J.

    2015-04-01

    The interplay between structural properties and charge transfer in self-assembled quantum ring (QR) chains grown by molecular beam epitaxy on top of an InGaAs/GaAs quantum dot (QD) superlattice template is analyzed and characterized. The QDs and QRs are vertically stacked and laterally coupled as well as aligned within each layer due to the strain field distributions that governs the ordering. The strong interdot coupling influences the carrier transfer both along as well as between chains in the ring layer and dot template structures. A qualitative contrast between different dynamic models has been developed. By combining temperature and excitation intensity effects, the tuning of the photoluminescence gain for either the QR or the QD mode is attained. The information obtained here about relaxation parameters, energy scheme, interlayer and interdot coupling resulting in creation of 1D structures is very important for the usage of such specific QR-QD systems for applied purposes such as lasing, detection, and energy-harvesting technology of future solar panels.

  18. Impairment of Electron Transfer Chain Induced by Acute Carnosine Administration in Skeletal Muscle of Young Rats

    Directory of Open Access Journals (Sweden)

    José Roberto Macarini

    2014-01-01

    Full Text Available Serum carnosinase deficiency is an inherited disorder that leads to an accumulation of carnosine in the brain tissue, cerebrospinal fluid, skeletal muscle, and other tissues of affected patients. Considering that high levels of carnosine are associated with neurological dysfunction and that the pathophysiological mechanisms involved in serum carnosinase deficiency remain poorly understood, we investigated the in vivo effects of carnosine on bioenergetics parameters, namely, respiratory chain complexes (I–III, II, and II-III, malate dehydrogenase, succinate dehydrogenase, and creatine kinase activities and the expression of mitochondrial-specific transcription factors (NRF-1, PGC-1α, and TFAM in skeletal muscle of young Wistar rats. We observed a significant decrease of complexes I–III and II activities in animals receiving carnosine acutely, as compared to control group. However, no significant alterations in respiratory chain complexes, citric acid cycle enzymes, and creatine kinase activities were found between rats receiving carnosine chronically and control group animals. As compared to control group, mRNA levels of NRF-1, PGC-1α, and TFAM were unchanged. The present findings indicate that electron transfer through the respiratory chain is impaired in skeletal muscle of rats receiving carnosine acutely. In case these findings are confirmed by further studies and ATP depletion is also observed, impairment of bioenergetics could be considered a putative mechanism responsible for the muscle damage observed in serum carnosinase-deficient patients.

  19. Mechanisms involved in the selective transfer of long chain polyunsaturted fatty acids to the fetus

    Directory of Open Access Journals (Sweden)

    Alfonso eGil-Sánchez

    2011-09-01

    Full Text Available The concentration of long chain polyunsaturated fatty acid (LCPUFA in the fetal brain increases dramatically from the third trimester until 18 months of life. Several studies have shown an association between the percentage of maternal plasma docosahexaenoic acid (DHA during gestation and development of the cognitive functions in the neonate. Since only very low levels of LCPUFA are synthesized in the fetus and placenta, their primary source for the fetus is that of maternal origin. Both in vitro and human in vivo studies using labelled fatty acids have shown the preferential transfer of LCPUFA from the placenta to the fetus compared with other fatty acids, although the mechanisms involved are still uncertain. The placenta takes up circulating maternal non-esterified fatty acids (NEFA and fatty acids released mainly by maternal lipoprotein lipase and endothelial lipase. These NEFA may enter the cell by passive diffusion or by means of membrane carrier proteins. Once in the cytosol, NEFA bind to cytosolic fatty acid-binding proteins for transfer to the fetal circulation or can be oxidized within the trophoblasts and even re-esterified and stored in lipid droplets (LD. Although trophoblast cells are not specialized in lipid storage, LCPUFA may up-regulate peroxisome proliferator activated receptor-γ (PPARγ and hence the gene expression of fatty acid transport carriers, fatty acid acyl-CoA synthetases and adipophilin or other enzymes related with lipolysis, modifying their rate of placental transfer and metabolization. The placental transfer of LCPUFA during pregnancy seems to be a key factor in the neurological development of the fetus. Increased knowledge on the factors that modify placental transfer of fatty acids would contribute to our understanding of this complex process.

  20. Side chain effects in reactions of the potassium-tyrosine charge transfer complex

    Science.gov (United States)

    da Silva, F. Ferreira; Meneses, G.; Ingólfsson, O.; Limão-Vieira, P.

    2016-10-01

    Fragmentation of transient negative ions of tyrosine formed through electron transfer in collisions with neutral potassium atoms is presented in the collision energy range from 30 to 75 eV. At low collision energies the dominating side chain channel observed corresponds to the cleavage of the bond from the para-position of the phenyl ring to the β-C of the remaining moiety, but cleavage of the Cαsbnd Cβ bond is also observed. Further fragments are formed through cleavage of the Cα bond to the carbonyl group, through decomposition of the carboxyl group or through significant decomposition of the backbone. The dehydrogenated molecular anion is also observed with appreciable intensity. These results are discussed in the context of earlier studies on dissociative electron attachment to tyrosine and other amino acids, as well as within the role of the side chain in electron induced decomposition of this aromatic amino acid. Stabilization of the temporary molecular anion in the transient collision complex is discussed and we argue that this may have significant influence on the branching ratios observed.

  1. Evaluation of food chain transfer of the antibiotic oxytetracycline and human risk assessment.

    Science.gov (United States)

    Boonsaner, Maliwan; Hawker, Darryl W

    2013-10-01

    There has been recent concern regarding the possibility of antibiotics entering the aquatic food chain and impacting human consumers. This work reports experimental results of the bioconcentration of the antibiotic oxytetracycline (OTC) by the Asian watermeal plant (Wolffia globosa Hartog & Plas) and bioaccumulation of OTC in watermeal and water by the seven-striped carp (Probarbus jullieni). They show, for the first time, the extent to which OTC is able to transfer from water to plant to fish and enter the food chain. The mean bioconcentration factor (dry weight basis) with watermeal was 1.28 × 10(3) L kg(-1). Separate experiments were undertaken to characterize accumulation of OTC by carp from water and watermeal. These showed the latter pathway to be dominant under the conditions employed. The bioconcentration and biomagnification factors for these processes were 1.75 L kg(-1) and 2 × 10(-4) kg g(-1) respectively. Using an aqueous concentration range of 0.34-3.0 μg L(-1), hazard quotients for human consumption of contaminated fish of 1.3 × 10(-2) to 1.15 × 10(-1) were derived.

  2. Influence of dispersants on trophic transfer of petroleum hydrocarbons in a marine food chain

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, M.; Tjeerdema, R. [Univ. of California, Santa Cruz, CA (United States). Dept. of Chemistry and Biochemistry; Sowby, M. [California Dept. of Fish and Game, Sacramento, CA (United States)

    1995-12-31

    When crude oil is accidentally released into the ocean, it threatens many levels of marine life. Intervention, in the form of chemical dispersing agents, alters the normal behavior of petroleum hydrocarbons (PH) by increasing their functional water solubility and the extent of their exposure to sub-surface organisms. Dispersing agents may modify bioavailability as a result of altered interactions between dispersed PH droplets and organismal cell membranes.The objective of this research was to determine the impact of dispersing agents on PH bioavailability and trophic transfer in primary levels of a marine food chain. Uptake, bioaccumulation, depuration, and metabolic transformation of a model PH, {sup 14}C-naphthalene, were measured and compared for Prudhoe Bay Crude Oil (PBCO) dispersed with Corexit 9527 and undispersed preparations of the water-accommodated fractions (WAF) of PBCO at two salinities and temperatures. The model food chain consisted of Isochrysis galbana and Brachionus plicatilis. Direct aqueous exposure was compared with combined aqueous and dietary exposure. Fractionation and identification of metabolites was done by HPLC co-chromatography with analytical standards, and quantitation was done by liquid scintillation counting. GC-FID characterization of WAF and dispersed oil (DO) preparations shows higher concentrations of petroleum hydrocarbons and a greater number of individual constituents in the dispersed oil preparations.

  3. Bioaccumulative and conchological assessment of heavy metal transfer in a soil-plant-snail food chain

    Directory of Open Access Journals (Sweden)

    Nica Dragos V

    2012-06-01

    Full Text Available Abstract Background Copper (Cu, zinc (Zn, cadmium (Cd, and lead (Pb can pose serious threats to environmental health because they tend to bioaccumulate in terrestrial ecosystems. We investigated under field conditions the transfer of these heavy metals in a soil-plant-snail food chain in Banat area, Romania. The main goal of this paper was to assess the Roman snail (Helix pomatia usefulness in environmental monitoring as bioindicator of heavy metal accumulation. Eight sampling sites, selected by different history of heavy metal (HM exposure, were chosen to be sampled for soil, nettle leaves, and newly matured snails. This study also aimed to identify the putative effects of HM accumulation in the environment on phenotypic variability in selected shell features, which included shell height (SH, relative shell height (RSH, and whorl number (WN. Results Significantly higher amounts of HMs were accumulated in snail hepatopancreas and not in foot. Cu, Zn, and Cd have biomagnified in the snail body, particularly in the hepatopancreas. In contrast, Pb decreased when going up into the food chain. Zn, Cd, and Pb correlated highly with each other at all levels of the investigated food chain. Zn and Pb exhibited an effective soil–plant transfer, whereas in the snail body only foot Cu concentration was correlated with that in soil. There were significant differences among sampling sites for WN, SH, and RSH when compared with reference snails. WN was strongly correlated with Cd and Pb concentrations in nettle leaves but not with Cu and Zn. SH was independent of HM concentrations in soil, snail hepatopancreas, and foot. However, SH correlated negatively with nettle leaves concentrations for each HM except Cu. In contrast, RSH correlated significantly only with Pb concentration in hepatopancreas. Conclusions The snail hepatopancreas accumulates high amounts of HMs, and therefore, this organ can function as a reliable biomarker for tracking HM bioavailability

  4. Bond-length alternation and charge transfer in a linear carbon chain encapsulated within a single-walled carbon nanotube

    Science.gov (United States)

    Rusznyák, Á.; Zólyomi, V.; Kürti, J.; Yang, S.; Kertesz, M.

    2005-10-01

    The physical properties of a linear carbon chain encapsulated within single-walled carbon nanotubes are investigated with density-functional theory using periodic boundary conditions. The dominant feature of an isolated carbon chain is the Peierls dimerization and the opening of a Peierls gap. The two weakly interacting subsystems (infinite carbon chain and nanotube) establish a common Fermi level, resulting in charge transfer (CT) which leads to a metallic combined system with a high density of states at the Fermi level. The rigid band model provides useful insights. Unusual physics arises from the effects of CT and chain-tube orbital hybridization which both tend to suppress the Peierls dimerization. Implications for the observed Raman spectrum of the chain-nanotube system are discussed.

  5. 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.

  6. Transfer of Paralytic Shellfish Toxins via Marine Food Chains:A Simulated Experiment

    Institute of Scientific and Technical Information of China (English)

    ZHI-JUN TAN; TIAN YAN; PEN-CHENG YU; MING-JIANG ZHOU

    2007-01-01

    Objective To study the transfer of paralytic shellfish toxins(PST)using four simulated marine food chains:d8noflagellate Alexandrium tamarense→Artemia Anemia salina→Mysid shrimp Neomysis awatschensis;A.tamarense→N.awatschensis:A.tamarense→A.salina→Perch Lateolabrax japonicus;and A.tamarenae→L. japonicus. Methods The ingestion of A.tamarenge.a producer of PST, by L. japonicus,N.awatschensis,and A.salina was first confirmed by microscopic observation of A.tamarense cells in the intestine samples of the three different organisms,and by the analysis of Chl.a levels in the samples.Toxin accumulation in L.japonicus and N.awatschensis directly from the feeding on A.tamarense 8r indirectly through the vector of A.salina was then studied.The toxicity of samples was measured using the AOAC mouse bioassay method,and the toxin content and profile of A.tamarense were analyzed by the HPLC method.Results Both A.salina and N.nwatschensis could ingest A.tamarense cells.However,the ingestion capability of A.salina exceeded that of N.L. japonicus.N.awatschensis and A.salina by microscopic observation.Therefore,the three organisms could ingest A.tamarense cells directly.A.salina could accumulate high content of PST,and the toxicity of A.salina in samples collected on of tested mice within 7 minutes,and the toxin content in artemia sample collected on the lst day was estimated to be 1.65×10-5 μg STX equal/individual.Toxin accumulation in L.japonicus and N.awatschensis directly from the feeding on A.tamarense or indirectly from the vector of A.salina was also studied.The mice injected with extracts from L.japonicus and N. awatschensis samples that accumulated PST either directly or indirectly showed PST intoxication symptoms,indicating that low levels of PST existed in these samples Conclusion Paralytic shellfish toxins can be transferred to L.japonicus,N.awatschensis,and A.salina from A.tamarense directly or indirectly via the food chains.

  7. The horizontal transfer of antibiotic resistance genes is enhanced by ionic liquid with different structure of varying alkyl chain length

    Directory of Open Access Journals (Sweden)

    Qing eWang

    2015-08-01

    Full Text Available Antibiotic resistance genes (ARGs have become a global health concern. In our previous study, an ionic liquid (IL 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][PF6] had been proven to facilitate the dissemination of ARGs in the environment. However, enhanced alkyl group chain length or the substitution of alkyl groups with the cation ring corresponded with increased antimicrobial effects. In this study, we investigated how different structures of ILs with 4, 6 and 8 C atoms in the longer alkyl chain on the imidazolium cations facilitated the dissemination of ARGs. The promotion of plasmid RP4 transfer frequency decreased with [CnMIM][BF4] increasing the alkyl chain length from 4 carbon atoms to 8 carbon atoms on the imidazolium cations, which is observed with [BMIM][BF4] (n=4, 5.9 fold> HMIM][BF4] (n=6, 2.2 fold> [OMIM][BF4] (n=8, 1.7 fold. This illustrates that [CnMIM][BF4] with increasing the alkyl chain length exert decreasing ability in facilitating plasmid RP4 horizontal transfer, which is possibly related to IL-structure dependent toxicity. The IL-structure dependent plasmid RP4 transfer frequency was attributable to bacterial cell membrane permeability weaken with increasing alkyl chain length of [CnMIM][PF4], which was evidenced by flow cytometry (FCM. In freshwater microcosm, [CnMIm][BF4] promoted the relative abundance of the sulI and intI genes for 4.6 folds, aphA and traF for 5.2 folds higher than the untreated groups, promoting the propagation of ARGs in the aquatic environment. This is the first report that ILs with different structure of varying alkyl chain length facilitate horizontal transfer of plasmid RP4 which is widely distributed in the environment, and thus add the adverse effects of the environmental risk of ILs.

  8. Multiple-spin coherence transfer in linear Ising spin chains and beyond: numerically-optimized pulses and experiments

    CERN Document Server

    Nimbalkar, Manoj; Neves, Jorge L; Elavarasi, S Begam; Yuan, Haidong; Khaneja, Navin; Dorai, Kavita; Glaser, Steffen J

    2011-01-01

    We study multiple-spin coherence transfers in linear Ising spin chains with nearest neighbor couplings. These constitute a model for efficient information transfers in future quantum computing devices and for many multi-dimensional experiments for the assignment of complex spectra in nuclear magnetic resonance spectroscopy. We complement prior analytic techniques for multiple-spin coherence transfers with a systematic numerical study where we obtain strong evidence that a certain analytically-motivated family of restricted controls is sufficient for time-optimality. In the case of a linear three-spin system, additional evidence suggests that prior analytic pulse sequences using this family of restricted controls are time-optimal even for arbitrary local controls. In addition, we compare the pulse sequences for linear Ising spin chains to pulse sequences for more realistic spin systems with additional long-range couplings between non-adjacent spins. We experimentally implement the derived pulse sequences in th...

  9. Markov chain formalism for generalized radiative transfer in a plane-parallel medium, accounting for polarization

    Science.gov (United States)

    Xu, Feng; Davis, Anthony B.; Diner, David J.

    2016-11-01

    A Markov chain formalism is developed for computing the transport of polarized radiation according to Generalized Radiative Transfer (GRT) theory, which was developed recently to account for unresolved random fluctuations of scattering particle density and can also be applied to unresolved spectral variability of gaseous absorption as an improvement over the standard correlated-k method. Using Gamma distribution to describe the probability density function of the extinction or absorption coefficient, a shape parameter a that quantifies the variability is introduced, defined as the mean extinction or absorption coefficient squared divided by its variance. It controls the decay rate of a power-law transmission that replaces the usual exponential Beer-Lambert-Bouguer law. Exponential transmission, hence classic RT, is recovered when a→∞. The new approach is verified to high accuracy against numerical benchmark results obtained with a custom Monte Carlo method. For a<∞, angular reciprocity is violated to a degree that increases with the spatial variability, as observed for finite portions of real-world cloudy scenes. While the degree of linear polarization in liquid water cloudbows, supernumerary bows, and glories is affected by spatial heterogeneity, the positions in scattering angle of these features are relatively unchanged. As a result, a single-scattering model based on the assumption of subpixel homogeneity can still be used to derive droplet size distributions from polarimetric measurements of extended stratocumulus clouds.

  10. Heat conduction in chain polymer liquids: molecular dynamics study on the contributions of inter- and intramolecular energy transfer.

    Science.gov (United States)

    Ohara, Taku; Yuan, Tan Chia; Torii, Daichi; Kikugawa, Gota; Kosugi, Naohiro

    2011-07-21

    In this paper, the molecular mechanisms which determine the thermal conductivity of long chain polymer liquids are discussed, based on the results observed in molecular dynamics simulations. Linear n-alkanes, which are typical polymer molecules, were chosen as the target of our studies. Non-equilibrium molecular dynamics simulations of bulk liquid n-alkanes under a constant temperature gradient were performed. Saturated liquids of n-alkanes with six different chain lengths were examined at the same reduced temperature (0.7T(c)), and the contributions of inter- and intramolecular energy transfer to heat conduction flux, which were identified as components of heat flux by the authors' previous study [J. Chem. Phys. 128, 044504 (2008)], were observed. The present study compared n-alkane liquids with various molecular lengths at the same reduced temperature and corresponding saturated densities, and found that the contribution of intramolecular energy transfer to the total heat flux, relative to that of intermolecular energy transfer, increased with the molecular length. The study revealed that in long chain polymer liquids, thermal energy is mainly transferred in the space along the stiff intramolecular bonds. This finding implies a connection between anisotropic thermal conductivity and the orientation of molecules in various organized structures with long polymer molecules aligned in a certain direction, which includes confined polymer liquids and self-organized structures such as membranes of amphiphilic molecules in water.

  11. Transfer of mercury and methylmercury along macroinvertebrate food chains in a floodplain lake of the Beni River, Bolivian Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Molina, Carlos Israel, E-mail: camoar6088@gmail.com [Instituto de Ecologia, Unidad de Limnologia, UMSA, Casilla postal 10077, La Paz (Bolivia, Plurinational State of); Institut de Recherche pour le Developpement IRD, Casilla postal 9214, La Paz (Bolivia, Plurinational State of); CONICET-Facultad de Ciencias Naturales, Universidad Nacional de Tucuman, Miguel Lillo 205, 4 000, Tucuman (Argentina); Gibon, Francois-Marie [Institut de Recherche pour le Developpement IRD, Casilla postal 9214, La Paz (Bolivia, Plurinational State of); IRD, UMR BOREA, Museum national d' Histoire Naturelle MNHN, Case postale 26, 75231, Paris cedex 05 (France); Duprey, Jean-Louis [Institut de Recherche pour le Developpement IRD, Casilla postal 9214, La Paz (Bolivia, Plurinational State of); Dominguez, Eduardo [CONICET-Facultad de Ciencias Naturales, Universidad Nacional de Tucuman, Miguel Lillo 205, 4 000, Tucuman (Argentina); Guimaraes, Jean-Remy D. [Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Bloco G-CCS, Rio de Janeiro, CEP 21949-900 (Brazil); Roulet, Marc [Institut de Recherche pour le Developpement IRD, Casilla postal 9214, La Paz (Bolivia, Plurinational State of)

    2010-07-15

    We have evaluated the mercury and methylmercury transfers to and within the macroinvertebrate communities of a floodplain lake of the Beni River basin, Bolivia, during three hydrological seasons and in two habitats (open water and vegetation belt). Using the stable isotopes {delta}{sup 13}C and {delta}{sup 15}N, six trophic chains were identified during a previous study. Four are based on only one source: seston, organic matter from the bottom sediment, periphyton and macrophytes. Two are based on mixed sources (seston and periphyton in one case, periphyton and macrophytes in the other). During sampling, we found only one taxon that had surface sediment organic matter as food source and very few taxa whose trophic source was constituted by macrophytes. The periphyton was the most important source during all seasons; it produced the longest chain, with three trophic positions. Whatever the season and trophic source, all collected macroinvertebrates contained methyl mercury and the latter was biomagnified in all trophic chains that we identified. The biomagnification of methylmercury through invertebrate trophic chains accurately reflected the existence and length of these chains. Biomagnification was virtually non-existent in the sediment-based chain, low and restricted to the dry season in the macrophyte-based chain. It was significant in the seston-based chain, but limited by the existence of only two trophic levels and restricted to the wet season. Finally, it was very effective in the periphyton-based chain, which offers the highest rate of contamination of the source but, above all, the largest number of trophic levels.

  12. Surface modification of carbon nanotubes via combination of mussel inspired chemistry and chain transfer free radical polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Qing; Tian, Jianwen; Liu, Meiying; Zeng, Guangjian; Huang, Qiang [Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031 (China); Wang, Ke; Zhang, Qingsong [Department of Chemistry and the Tsinghua Center for Frontier Polymer Research, Tsinghua University, Beijing, 100084 (China); Deng, Fengjie, E-mail: fengjiedeng@aliyun.com [Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031 (China); Zhang, Xiaoyong, E-mail: xiaoyongzhang1980@gmail.com [Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031 (China); Wei, Yen, E-mail: weiyen@tsinghua.edu.cn [Department of Chemistry and the Tsinghua Center for Frontier Polymer Research, Tsinghua University, Beijing, 100084 (China)

    2015-08-15

    Graphical abstract: A novel strategy combination of mussel inspired chemistry and chain transfer free radical polymerization has been developed for surface modification of carbon nanotubes with polymers for the first time. - Highlights: • Surface modification of CNTs via mussel inspired chemistry. • Preparation of aminated polymers through free radical polymerization. • Functionalized CNTs with aminated polymers via Michael addition reaction. • Highly dispersed CNTs in organic and aqueous solution. - Abstract: In this work, a novel strategy for surface modification of carbon nanotubes (CNTs) was developed via combination of mussel inspired chemistry and chain transfer free radical polymerization. First, pristine CNTs were functionalized with polydopamine (PDA), which is formed via self-polymerization of dopamine in alkaline conditions. These PDA functionalized CNTs can be further reacted with amino-terminated polymers (named as PDMC), which was synthesized through chain transfer free radical polymerization using cysteamine hydrochloride as chain transfer agent and methacryloxyethyltrimethyl ammonium chloride as the monomer. PDMC perfectly conjugated with CNT-PDA was ascertained by a series of characterization techniques including transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The dispersibility of obtained CNT nanocomposites (named as CNT-PDA-PDMC) was further examined. Results showed that the dispersibility of CNT-PDA-PDMC in aqueous and organic solutions was obviously enhanced. Apart from PDMC, many other amino-terminated polymers can also be used to functionalization of CNTs via similar strategy. Therefore, the method described in this work should be a general strategy for fabrication various polymer nanocomposites.

  13. Optimal control of fast and high-fidelity quantum state transfer in spin-1/2 chains

    Science.gov (United States)

    Zhang, Xiong-Peng; Shao, Bin; Hu, Shuai; Zou, Jian; Wu, Lian-Ao

    2016-12-01

    Spin chains are promising candidates for quantum communication and computation. Using quantum optimal control (OC) theory based on the Krotov method, we present a protocol to perform quantum state transfer with fast and high fidelity by only manipulating the boundary spins in a quantum spin-1/2 chain. The achieved speed is about one order of magnitude faster than that is possible in the Lyapunov control case for comparable fidelities. Additionally, it has a fundamental limit for OC beyond which optimization is not possible. The controls are exerted only on the couplings between the boundary spins and their neighbors, so that the scheme has good scalability. We also demonstrate that the resulting OC scheme is robust against disorder in the chain.

  14. Surface modification of carbon nanotubes via combination of mussel inspired chemistry and chain transfer free radical polymerization

    Science.gov (United States)

    Wan, Qing; Tian, Jianwen; Liu, Meiying; Zeng, Guangjian; Huang, Qiang; Wang, Ke; Zhang, Qingsong; Deng, Fengjie; Zhang, Xiaoyong; Wei, Yen

    2015-08-01

    In this work, a novel strategy for surface modification of carbon nanotubes (CNTs) was developed via combination of mussel inspired chemistry and chain transfer free radical polymerization. First, pristine CNTs were functionalized with polydopamine (PDA), which is formed via self-polymerization of dopamine in alkaline conditions. These PDA functionalized CNTs can be further reacted with amino-terminated polymers (named as PDMC), which was synthesized through chain transfer free radical polymerization using cysteamine hydrochloride as chain transfer agent and methacryloxyethyltrimethyl ammonium chloride as the monomer. PDMC perfectly conjugated with CNT-PDA was ascertained by a series of characterization techniques including transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The dispersibility of obtained CNT nanocomposites (named as CNT-PDA-PDMC) was further examined. Results showed that the dispersibility of CNT-PDA-PDMC in aqueous and organic solutions was obviously enhanced. Apart from PDMC, many other amino-terminated polymers can also be used to functionalization of CNTs via similar strategy. Therefore, the method described in this work should be a general strategy for fabrication various polymer nanocomposites.

  15. Enhancement of entanglement transfer in a spin chain by phase shift control

    CERN Document Server

    Maruyama, K; Nori, F

    2006-01-01

    We study the effect of a phase shift on the amount of transferrable two-spin entanglement in a spin chain. We consider a ferromagnetic Heisenberg/XY spin chain, both numerically and analytically, and two mechanisms to generate a phase shift, the Aharonov-Casher effect and the Dzyaloshinskii-Moriya interaction. In both cases, the maximum attainable entanglement is shown to be significantly enhanced, suggesting its potential usefulness in quantum information processing.

  16. Developing a Taxonomy and Model to Transfer and Assess Best Practices for Supply Chain Management

    Science.gov (United States)

    Flores, Myrna; Mendoza, Ana; Lavin, Victor; Flores, Benito

    Supply Chain Management can be briefly defined as the orchestration of a network of entities such as suppliers, distributors and clients to achieve a common goal: delivering cost efficient products and services exceeding customers’ expectations. Therefore, firms should consider all those End-to-End processes enabling an efficient integration and interoperability of partners collaborating in such Supply Chain when designing their Business Process Architecture (BPA). One key enabler to accomplish this goal is the identification, documentation and sharing of best practices. This paper describes the outcomes of a collaborative project carried out by CEMEX Research Group and the Universidad de Monterrey (UDEM), which focused on developing taxonomy to document best practices for the supply chain management together with a generic model to evaluate their level of implementation.

  17. Transfer and effects of 1,2,3,5,7-pentachloronaphthalene in an experimental food chain

    DEFF Research Database (Denmark)

    Slootweg, Tineke; Segner, Helmut; Mayer, Philipp;

    2015-01-01

    of this study was to gain insights into the biomagnification and effects of 1,2,3,5,7-pentachloronaphthalene (PeCN52) in an experimental food chain consisting of benthic worms and juvenile rainbow trout. Worms were contaminated with PeCN52 by passive dosing from polydimethylsiloxane silicone. The contaminated...

  18. Enhancing Chinese Agribusiness Supply Chains with Internet Technologies: A Transnational Knowledge Transfer Approach

    Science.gov (United States)

    Duan, Yanqing; Bentley, Yongmei; Fu, Zetian; Zografos, Konstantinos; Bemeleit, Boris

    2008-01-01

    This paper reports research findings from a project funded by the European Commission. The research used case studies and surveys to identify gaps between Europe and China in the level of Internet adoption in fresh-produce supply chains. The project reveals barriers to Internet adoption in China in this industry, and employs a transnational…

  19. SYNTHESIS OF HETEROARM STAR-SHAPED POLYMER BY THE USE OF POLYFUNCTIONAL CHAIN-TRANSFER AGENT via CONVENTIONAL FREE RADICAL POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Zhi-hua Luo; Zhi-feng Fu; Yan Shi

    2008-01-01

    Heteroarm star-shaped polymers were synthesized by conventional free radical polymerization in two steps by the use of polyfunctional chain transfer agent. In the first step, free radical polymerization of methyl methacrylate was carried out in the presence of a polyfunctional chain transfer agent, pentaerythritol tetrakis(3-mercaptopropinate). At appropriate monomer conversions, two-arm PMMA having two residual thiol groups at the chain center or three-arm PMMA having one residual thiol group at the core were obtained. In the second step, free radical polymerization of styrene was carried out using PMMAs obtained above as macro-chain transfer agent. When styrene conversion was lower than 30%, heteroarm star-shaped polymers, (PMMA)2(PS)a and (PMMA)3(PS), were obtained successfully.

  20. Biomimetic surface modification of polypropylene by surface chain transfer reaction based on mussel-inspired adhesion technology and thiol chemistry

    Science.gov (United States)

    Niu, Zhijun; Zhao, Yang; Sun, Wei; Shi, Suqing; Gong, Yongkuan

    2016-11-01

    Biomimetic surface modification of polypropylene (PP) is conducted by surface chain transfer reaction based on the mussel-inspired versatile adhesion technology and thiol chemistry, using 2-methacryloyloxyethylphosphorylcholine (MPC) as a hydrophilic monomer mimicking the cell outer membrane structure and 2,2-azobisisobutyronitrile (AIBN) as initiator in ethanol. A layer of polydopamine (PDA) is firstly deposited onto PP surface, which not only offers good interfacial adhesion with PP, but also supplies secondary reaction sites (-NH2) to covalently anchor thiol groups onto PP surface. Then the radical chain transfer to surface-bonded thiol groups and surface re-initiated polymerization of MPC lead to the formation of a thin layer of polymer brush (PMPC) with cell outer membrane mimetic structure on PP surface. X-ray photoelectron spectrophotometer (XPS), atomic force microscopy (AFM) and water contact angle measurements are used to characterize the PP surfaces before and after modification. The protein adsorption and platelet adhesion experiments are also employed to evaluate the interactions of PP surface with biomolecules. The results show that PMPC is successfully grafted onto PP surface. In comparison with bare PP, the resultant PP-PMPC surface exhibits greatly improved protein and platelet resistance performance, which is the contribution of both increased surface hydrophilicity and zwitterionic structure. More importantly, the residue thiol groups on PP-PMPC surface create a new pathway to further functionalize such zwitterion modified PP surface.

  1. Photoinduced intramolecular charge transfer in push-pull polyenes: effects of solvation, electron-donor group, and polyenic chain length.

    Science.gov (United States)

    Akemann, Walther; Laage, Damien; Plaza, Pascal; Martin, Monique M; Blanchard-Desce, Mireille

    2008-01-17

    Subpicosecond absorption spectroscopy is used to characterize the primary photoinduced processes in a class of push-pull polyenes bearing a julolidine end group as the electron donor and a diethylthiobarbituric acid end group as the electron acceptor. The excited-state decay time and relaxation pathway have been studied for four polyenes of increasing chain length (n = 2-5 double bonds) in aprotic solvents of different solvation time, polarity, and viscosity. Intramolecular charge transfer (ICT) leading to a transient state of cyanine-like structure (fully conjugated with no bond length alternation) is observed in all polar solvents at a solvent dependent rate, but the reaction is not observed in cyclohexane, a nonpolar solvent. In polar solvents, the reaction time increases with the average solvation time but remains slightly larger, except in the viscous solvent triacetin. These facts are interpreted as an indication that both solvent reorganization and internal restructuring are involved in the ICT-state formation. The observed photodynamics resemble those we previously found for another class of polyenes bearing a dibutylaniline group as the donor, including a similar charge-transfer rate in spite of the larger electron donor character of the julolidine group. This observation brings further support to the proposal that an intramolecular coordinate is involved in the charge-transfer reaction, possibly a torsional motion of the donor end group. On the other hand, relaxation of the ICT state leads to cis-trans isomerization or crossing to the triplet state, depending on the length of the polyenic chain. In dioxane, tetrahydrofuran, and triacetin, the ICT state of the shorter chains (n = 2, 3) relaxes to the isomer with a viscosity-dependent rate, while that of the longer ones (n = 4, 5) leads to the triplet state with a viscosity-independent rate, as expected. In acetonitrile, the ICT-state lifetime is generally much shorter. A change from photoisomerization to

  2. An 'adding' algorithm for the Markov chain formalism for radiation transfer

    Science.gov (United States)

    Esposito, L. W.

    1979-01-01

    An adding algorithm is presented, that extends the Markov chain method and considers a preceding calculation as a single state of a new Markov chain. This method takes advantage of the description of the radiation transport as a stochastic process. Successive application of this procedure makes calculation possible for any optical depth without increasing the size of the linear system used. It is determined that the time required for the algorithm is comparable to that for a doubling calculation for homogeneous atmospheres. For an inhomogeneous atmosphere the new method is considerably faster than the standard adding routine. It is concluded that the algorithm is efficient, accurate, and suitable for smaller computers in calculating the diffuse intensity scattered by an inhomogeneous planetary atmosphere.

  3. Transfer of radionuclides from high polluted bottom sediments to marine organisms through benthic food chain in post Fukushima period

    Science.gov (United States)

    Bezhenar, Roman; Jung, Kyung Tae; Maderich, Vladimir; Willemsen, Stefan; de With, Govert; Qiao, Fangli

    2015-04-01

    A catastrophic earthquake and tsunami occurred on March 11, 2011 and severely damaged the Fukushima Daiichi Nuclear Power Plant (FDNPP) that resulted in an uncontrolled release of radioactivity into air and ocean. Around 80% of the radioactivity released due to the FDNPP accident in March-April 2011 was either directly discharged into the ocean or deposited onto the ocean surface from the atmosphere. A large amount of long-lived radionuclides (mainly Cs-137) were released into the environment. The concentration of radionuclides in the ocean reached a maximum in mid-April of 2011, and then gradually decreased. From 2011 the concentration of Cs-137 in water essentially fell except the area around the FDNPP where leaks of contaminated water are continued. However, in the bottom sediment high concentrations of Cs-137 were found in the first months after the accident and slowly decreased with time. Therefore, it should be expected that a time delay is found of sediment-bound radionuclides in marine organisms. For the modeling of radionuclide transfer from highly polluted bottom sediments to marine organisms the dynamical food chain model BURN-POSEIDON (Heling et al, 2002; Maderich et al., 2014) was extended. In this model marine organisms are grouped into a limited number of classes based on their trophic level and type of species. These include: phytoplankton, zooplankton, fishes (two types: piscivorous and non-piscivorous), crustaceans, and molluscs for pelagic food chain and bottom sediment invertebrates, demersal fishes and bottom predators for benthic food chain and whole water column predators feeding by pelagial and benthic fishes. Bottom invertebrates consume organic parts of bottom sediments with adsorbed radionuclides which then migrate through the food chain. All organisms take radionuclides directly from water as well as via food. In fishes where radioactivity is not homogeneously distributed over all tissues of the organism, it is assumed that radionuclide

  4. Characterization and Diagnostic Value of Amino Acid Side Chain Neutral Losses Following Electron-Transfer Dissociation

    Science.gov (United States)

    Xia, Qiangwei; Lee, M. Violet; Rose, Christopher M.; Marsh, Alyce J.; Hubler, Shane L.; Wenger, Craig D.; Coon, Joshua J.

    2011-02-01

    Using a large set of high mass accuracy and resolution ETD tandem mass spectra, we characterized ETD-induced neutral losses. From these data we deduced the chemical formula for 20 of these losses. Many of them have been previously observed in electron-capture dissociation (ECD) spectra, such as losses of the side chains of arginine, aspartic acid, glutamic acid, glutamine, asparagine, leucine, histidine, and carbamidomethylated cysteine residues. With this information, we examined the diagnostic value of these amino acid-specific losses. Among 1285 peptide-spectrum matches, 92.5% have agreement between neutral loss-derived peptide amino acid composition and the peptide sequences. Moreover, we show that peptides can be uniquely identified by using only the accurate precursor mass and amino acid composition based on neutral losses; the median number of sequence candidates from an accurate mass query is reduced from 21 to 8 by adding side chain loss information. Besides increasing confidence in peptide identification, our findings suggest the potential use of these diagnostic losses in ETD spectra to improve false discovery rate estimation and to enhance the performance of scoring functions in database search algorithms.

  5. Ethylene homo- and copolymerization chain-transfers: A perspective from supported (nBuCp)2ZrCl2 catalyst active centre distribution

    Indian Academy of Sciences (India)

    Muhammad Atiqullah; Mamdouh A Al-Harthi; Siripon Anantawaraskul; Abdul-hamid M Emwas

    2015-04-01

    Polymerization chain termination reactions and unsaturation of the polymer backbone end are related. Therefore, in this study, the parameters resulting from the modelling of the active centre distribution of the supported catalyst—silica/MAO/(nBuCp)2ZrCl2—were applied to evaluate the active-centredependent ethylene homo- and copolymerization rates, as well as the corresponding chain termination rates. This approach, from a microkinetic mechanistic viewpoint, elucidates better the 1-hexene-induced positive comonomer effect and chain transfer phenomenon. The kinetic expressions, developed on the basis of the proposed polymerization mechanisms, illustrate how the active site type-dependent chain transfer phenomenon is influenced by the different apparent termination rate constants and momoner concentrations. The active centrespecific molecular weight Mni (for the above homo- and copolymer), as a function of chain transfer probability, pCTi, varied as follows: log(pCTi) = log(mwru)−log(Mni) where mwru is the molecular weight of the repeat unit. The physical significance of this finding has been explained. The homo- and copolymer backbones showed all the three chain end unsaturations (vinyl, vinylidene, and trans-vinylene). The postulated polymerization mechanisms reveal the underlying polymer chemistry. The results of the present study will contribute to develop in future supported metallocene catalysts that will be useful to synthesize polyethylene precursors having varying chain end unsaturations, which can be eventually used to prepare functional polyethylenes.

  6. Electrochemical studies of a reconstituted photosynthetic electron-transfer chain or towards a biomimetic photoproduction of hydrogen; Etudes electrochimiques de chaines de transfert d'electrons photosynthetiques ou vers une photoproduction biomimetique d'hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    Fourmond, V

    2007-04-15

    The aim of this work is to find an efficient process to convert solar energy into hydrogen. The electrons transfers in reconstituted photosynthetic chains have been particularly studied with the aims 1)in one hand, to better understand the interactions of the different molecules of the photosynthetic chain in order to optimize the changes of the entire organisms for hydrogen production 2)in another hand, to insert the hydrogenases in a photosynthetic chain and then to photo reduce them in order to obtain kinetic data to better understand how it works. (O.M.)

  7. Innovations in the supply chain and construction engineering of nuclear-based heat transfer components

    Energy Technology Data Exchange (ETDEWEB)

    Perales, A. [Equipos Nucleares, S.A. - Ensa, Jose Ortega y Gasset, 28006 Madrid (Spain); Woolf, G. [Tecnicas Reunidas - TR, Arapiles, 28014 Madrid (Spain)

    2010-07-01

    Equipos Nucleares S.A. (Ensa) and Tecnicas Reunidas S.A. (TR), both long-established Spanish companies, have brought together innovative approaches for the supply of heat transfer solution packages by combining their respective experiences in heat exchanger design (TR), manufacturing (Ensa), and nuclear materials procurement (Ensa and TR), thereby founding a new potent European component supplier for nuclear power plants with over 50 years of experience in the global nuclear market. The combined strategy of the Ensa-TR association which addresses the problems currently faced by nuclear component suppliers is described herein. (authors)

  8. Chain length distributions in linear polyaddition proceeding in nano-scale small volumes without mass transfer

    Science.gov (United States)

    Szymanski, R.; Sosnowski, S.

    2017-01-01

    Computer simulations (Monte Carlo and numerical integration of differential equations) and theoretical analysis show that the statistical nature of polyaddition, both irreversible and reversible one, affects the way the macromolecules of different lengths are distributed among the small volume nano-reactors (droplets in this study) at any reaction time. The corresponding droplet distributions in respect to the number of reacting chains as well as the chain length distributions depend, for the given reaction time, on rate constants of polyaddition kp and depolymerization kd (reversible process), and the initial conditions: monomer concentration and the number of its molecules in a droplet. As a model reaction, a simple polyaddition process (M)1+(M)1 ⟶ ⟵ (M)2 , (M)i+(M)j ⟶ ⟵ (M)i+j was chosen, enabling to observe both kinetic and thermodynamic (apparent equilibrium constant) effects of a small number of reactant molecules in a droplet. The average rate constant of polymerization is lower than in a macroscopic system, depending on the average number of reactant molecules in a droplet. The apparent equilibrium constants of polymerization Ki j=[(M)i +j] ¯ /([(M)i] ¯ [(M)j] ¯ ) appear to depend on oligomer/polymer sizes as well as on the initial number of monomer molecules in a droplet. The corresponding equations, enabling prediction of the equilibrium conditions, were derived. All the analyzed effects are observed not only for ideally dispersed systems, i.e. with all droplets containing initially the same number of monomer (M)1 molecules, but also when initially the numbers of monomer molecules conform the Poisson distribution, expected for dispersions of reaction mixtures.

  9. A silica-immobilized pt2+catalyst for the selective, aerobic oxidation of methane via an electron-transfer chain

    Institute of Scientific and Technical Information of China (English)

    Zengjian An; Xiulian Pan; Xiumei Liu; Xiuwen Han; Xinhe Bao

    2008-01-01

    The combination of Pt2+, benzoquinone and NaNO2 forms an electron-transfer chain, which leads to the oxidation of methane by O2 in CF3COOH aqueous solution. The overall turnover number per hour (TOF) of methane at 120 ℃ is 0.5 h-1, however, only about one fourth (23%) of methane is converted to the desired product of methanol in the formation of CF3COOCH3. The over-oxidation of methane to CO2, over the catalyst with the Pt2+ species immobilized via 2,2'-bipyridyl as a ligand on the silica substrate, is depressed distinctly. Under the same conditions, the conversion to methanol dominates, and no CO2 is observed, on account of the over-oxidation of methane, as confirmed by the isotope experiment.

  10. Biomimetic surface modification of polypropylene by surface chain transfer reaction based on mussel-inspired adhesion technology and thiol chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Zhijun; Zhao, Yang; Sun, Wei; Shi, Suqing, E-mail: shisq@nwu.edu.cn; Gong, Yongkuan

    2016-11-15

    Highlights: • Biomimetic surface modification of PP was successfully conducted by integrating mussel-inspired technology, thiol chemistry and cell outer membranes-like structures. • The resultant biomimetic surface exhibits good interface and surface stability. • The obvious suppression of protein adsorption and platelet adhesion is also achieved. • The residue thoil groups on the surface could be further functionalized. - Abstract: Biomimetic surface modification of polypropylene (PP) is conducted by surface chain transfer reaction based on the mussel-inspired versatile adhesion technology and thiol chemistry, using 2-methacryloyloxyethylphosphorylcholine (MPC) as a hydrophilic monomer mimicking the cell outer membrane structure and 2,2-azobisisobutyronitrile (AIBN) as initiator in ethanol. A layer of polydopamine (PDA) is firstly deposited onto PP surface, which not only offers good interfacial adhesion with PP, but also supplies secondary reaction sites (-NH{sub 2}) to covalently anchor thiol groups onto PP surface. Then the radical chain transfer to surface-bonded thiol groups and surface re-initiated polymerization of MPC lead to the formation of a thin layer of polymer brush (PMPC) with cell outer membrane mimetic structure on PP surface. X-ray photoelectron spectrophotometer (XPS), atomic force microscopy (AFM) and water contact angle measurements are used to characterize the PP surfaces before and after modification. The protein adsorption and platelet adhesion experiments are also employed to evaluate the interactions of PP surface with biomolecules. The results show that PMPC is successfully grafted onto PP surface. In comparison with bare PP, the resultant PP-PMPC surface exhibits greatly improved protein and platelet resistance performance, which is the contribution of both increased surface hydrophilicity and zwitterionic structure. More importantly, the residue thiol groups on PP-PMPC surface create a new pathway to further functionalize such

  11. Effect of Trapping Agent and Polystyrene Chain End Functionality on Radical Trap-Assisted Atom Transfer Radical Coupling

    Directory of Open Access Journals (Sweden)

    Elizabeth M. Carnicom

    2014-10-01

    Full Text Available Coupling reactions were performed to gauge the effect of the inclusion of a radical trap on the success of coupling reactions of monohalogenated polystyrene (PSX chains in atom transfer radical coupling (ATRC type reactions. The effect of both the specific radical trap chosen and the structure of the polymer chain end were evaluated by the extent of dimerization observed in a series of analogous coupling reactions. The commonly used radical trap 2-methyl-2-nitrosopropane (MNP showed the highest amounts of dimerization for PSX (X = Br, Cl compared to coupling reactions performed in its absence or with a different radical trap. A dinitroxide coupling agent was also studied with the extent of coupling nearly matching the effectiveness of MNP in RTA (Radical trap-assisted-ATRC reactions, while N-nitroso and electron rich nitroso coupling agents were the least effective. (2,2,6,6-Tetramethyl-piperin-l-yloxyl-capped PS (PS-TEMPO, prepared by NMP, was subjected to a coupling sequence conceptually similar to RTA-ATRC, but dimerization was not observed regardless of the choice of radical trap. Kinetic experiments were performed to observe rate changes on the coupling reaction of PSBr as a result of the inclusion of MNP, with substantial rate enhancements found in the RTA-ATRC coupling sequence compared to traditional ATRC.

  12. The transfer of titanium dioxide nanoparticles from the host plant to butterfly larvae through a food chain

    Science.gov (United States)

    Kubo-Irie, Miyoko; Yokoyama, Masaaki; Shinkai, Yusuke; Niki, Rikio; Takeda, Ken; Irie, Masaru

    2016-03-01

    This study aimed to examine the transfer of nanoparticles within a terrestrial food chain. Oviposited eggs of the swallowtail butterfly (Atrophaneura alcinous) were hatched on the leaves of the host plant (Aristolochia debilis), and the root stock and root hairs were submerged in a suspension of 10 μg/ml titanium dioxide nanoparticles (TiO2-NPs) in a 100 ml bottle. The presence of TiO2-NPs in the veins of the leaves was confirmed by X-ray analytical microscopy (X-ray AM). The hatched 1st instar larvae fed on the leaves to moult into 2nd instar larvae. Small agglomerates of TiO2-NPs less than 150 nm in diameter were identified in the vascular tissue of the exposed plant, the midgut and the excreta of the larvae by transmission electron microscopy. The image of Ti elemental mapping by X-ray AM was analysed with the quantitative spatial information mapping (QSIM) technique. The results demonstrated that TiO2-NPs were transferred from the plant to the larvae and they were disseminated throughout the environment via larval excreta.

  13. Dissection of the triple tryptophan electron transfer chain in Escherichia coli DNA photolyase: Trp382 is the primary donor in photoactivation

    OpenAIRE

    2003-01-01

    In Escherichia coli photolyase, excitation of the FAD cofactor in its semireduced radical state (FADH•) induces an electron transfer over ≈15 Å from tryptophan W306 to the flavin. It has been suggested that two additional tryptophans are involved in an electron transfer chain FADH• ← W382 ← W359 ← W306. To test this hypothesis, we have mutated W382 into redox inert phenylalanine. Ultrafast transient absorption studies showed that, in WT photolyase, excited FADH• de...

  14. Revealing the Supramolecular Nature of Side-Chain Terpyridine-Functionalized Polymer Networks

    Directory of Open Access Journals (Sweden)

    Jérémy Brassinne

    2015-01-01

    Full Text Available Nowadays, finely controlling the mechanical properties of polymeric materials is possible by incorporating supramolecular motifs into their architecture. In this context, the synthesis of a side-chain terpyridine-functionalized poly(2-(dimethylaminoethyl methacrylate is reported via reversible addition-fragmentation chain transfer polymerization. By addition of transition metal ions, concentrated aqueous solutions of this polymer turn into metallo-supramolecular hydrogels whose dynamic mechanical properties are investigated by rotational rheometry. Hence, the possibility for the material to relax mechanical constrains via dissociation of transient cross-links is brought into light. In addition, the complex phenomena occurring under large oscillatory shear are interpreted in the context of transient networks.

  15. Metal Ion-dependent Heavy Chain Transfer Activity of TSG-6 Mediates Assembly of the Cumulus-Oocyte Matrix.

    Science.gov (United States)

    Briggs, David C; Birchenough, Holly L; Ali, Tariq; Rugg, Marilyn S; Waltho, Jon P; Ievoli, Elena; Jowitt, Thomas A; Enghild, Jan J; Richter, Ralf P; Salustri, Antonietta; Milner, Caroline M; Day, Anthony J

    2015-11-27

    The matrix polysaccharide hyaluronan (HA) has a critical role in the expansion of the cumulus cell-oocyte complex (COC), a process that is necessary for ovulation and fertilization in most mammals. Hyaluronan is organized into a cross-linked network by the cooperative action of three proteins, inter-α-inhibitor (IαI), pentraxin-3, and TNF-stimulated gene-6 (TSG-6), driving the expansion of the COC and providing the cumulus matrix with its required viscoelastic properties. Although it is known that matrix stabilization involves the TSG-6-mediated transfer of IαI heavy chains (HCs) onto hyaluronan (to form covalent HC·HA complexes that are cross-linked by pentraxin-3) and that this occurs via the formation of covalent HC·TSG-6 intermediates, the underlying molecular mechanisms are not well understood. Here, we have determined the tertiary structure of the CUB module from human TSG-6, identifying a calcium ion-binding site and chelating glutamic acid residue that mediate the formation of HC·TSG-6. This occurs via an initial metal ion-dependent, non-covalent, interaction between TSG-6 and HCs that also requires the presence of an HC-associated magnesium ion. In addition, we have found that the well characterized hyaluronan-binding site in the TSG-6 Link module is not used for recognition during transfer of HCs onto HA. Analysis of TSG-6 mutants (with impaired transferase and/or hyaluronan-binding functions) revealed that although the TSG-6-mediated formation of HC·HA complexes is essential for the expansion of mouse COCs in vitro, the hyaluronan-binding function of TSG-6 does not play a major role in the stabilization of the murine cumulus matrix.

  16. Ethylene homo- and copolymerization chain-transfers: A perspective from supported (n BuCp) 2 ZrCl 2 catalyst active centre distribution

    KAUST Repository

    Atiqullah, Muhammad

    2015-04-01

    Polymerization chain termination reactions and unsaturation of the polymer backbone end are related. Therefore, in this study, the parameters resulting from the modelling of the active centre distribution of the supported catalyst - silica/MAO/(nBuCp)2ZrCl2 - were applied to evaluate the active-centre-dependent ethylene homo- and copolymerization rates, as well as the corresponding chain termination rates. This approach, from a microkinetic mechanistic viewpoint, elucidates better the 1-hexene-induced positive comonomer effect and chain transfer phenomenon. The kinetic expressions, developed on the basis of the proposed polymerization mechanisms, illustrate how the active site type-dependent chain transfer phenomenon is influenced by the different apparent termination rate constants and momoner concentrations. The active centre-specific molecular weight M ni (for the above homo- and copolymer), as a function of chain transfer probability, p CTi, varied as follows: log (p C Ti) = log (mwru) - log (Mn i), where mw ru is the molecular weight of the repeat unit. The physical significance of this finding has been explained. The homo- and copolymer backbones showed all the three chain end unsaturations (vinyl, vinylidene, and trans-vinylene). The postulated polymerization mechanisms reveal the underlying polymer chemistry. The results of the present study will contribute to develop in future supported metallocene catalysts that will be useful to synthesize polyethylene precursors having varying chain end unsaturations, which can be eventually used to prepare functional polyethylenes. [Figure not available: see fulltext.] © 2015 Indian Academy of Sciences.

  17. A hermetic self-sustained microbial solar cell based on Chlorella vulgaris and a versatile charge transfer chain

    Science.gov (United States)

    Pan, Keliang; Zhou, Peijiang

    2015-10-01

    A hermetic noble-metal-free membrane-less microbial solar cell (MSC) is established. The substances decomposition and regeneration in this MSC are carried out only by Chlorella vulgaris simultaneously. The conversion of metabolism types of C. vulgaris is controlled only by illumination. By using a pleiotropic redox mediator and a cupric hexacyanoferrate modified cathode, a two-phase three-stage charge transfer chain is formed. Through this pathway, the one microorganism self-sustained system gets a long-term power output up to 0.04773 mW/cm2 at 0.423 V without any material exchange with external, which is 50 times higher than that obtained from the original system. Benefiting from this electron buffer system, the battery will achieve an electricity generation in both light and dark conditions. There is almost no consumption of any substrates throughout the stabilized process, and no more additions are required. This maintenance-free and extremely inexpensive reactor with a simple structure and a long service life demonstrates the possibility of combining the microbial, chemical and photo cells.

  18. Xanthohumol induces generation of reactive oxygen species and triggers apoptosis through inhibition of mitochondrial electron transfer chain complex I.

    Science.gov (United States)

    Zhang, Bo; Chu, Wei; Wei, Peng; Liu, Ying; Wei, Taotao

    2015-12-01

    Xanthohumol is a prenylflavonoid extracted from hops (Humulus lupulus). It possesses anti-cancer and anti-inflammatory activities in vitro and in vivo, and offers therapeutic benefits for treatment of metabolic syndromes. However, the precise mechanisms underlying its pharmacological effects remain to be elucidated, together with its cellular target. Here, we provide evidence that xanthohumol directly interacts with the mitochondrial electron transfer chain complex I (NADH dehydrogenase), inhibits the oxidative phosphorylation, triggers the production of reactive oxygen species, and induces apoptosis. In addition, we show that as a result of the inhibition of the mitochondrial oxidative phosphorylation, xanthohumol exposure causes a rapid decrease of mitochondrial transmembrane potential. Furthermore, we showed that xanthohumol up-regulates the glycolytic capacity in cells, and thus compensates cellular ATP generation. Dissection of the multiple steps of aerobic respiration by extracellular flux assays revealed that xanthohumol specifically inhibits the activity of mitochondrial complex I, but had little effect on that of complex II, III and IV. Inhibition of complex I by xanthohumol caused the overproduction of reactive oxygen species, which are responsible for the induction of apoptosis in cancer cells. We also found that isoxanthohumol, the structural isomer of xanthohumol, is inactive to cells, suggesting that the reactive 2-hydroxyl group of xanthohumol is crucial for its targeting to the mitochondrial complex I. Together, the remodeling of cell metabolism revealed here has therapeutic potential for the use of xanthohumol.

  19. Falling chains

    Science.gov (United States)

    Wong, Chun Wa; Yasui, Kosuke

    2006-06-01

    The one-dimensional fall of a folded chain with one end suspended from a rigid support and a chain falling from a resting heap on a table is studied. Because their Lagrangians contain no explicit time dependence, the falling chains are conservative systems. Their equations of motion are shown to contain a term that enforces energy conservation when masses are transferred between subchains. We show that Cayley's 1857 energy nonconserving solution for a chain falling from a resting heap is incorrect because it neglects the energy gained when a link leaves a subchain. The maximum chain tension measured by Calkin and March for the falling folded chain is given a simple if rough interpretation. Other aspects of the falling folded chain are briefly discussed.

  20. Quantum yield measurements of short-lived photoactivation intermediates in DNA photolyase: toward a detailed understanding of the triple tryptophan electron transfer chain.

    Science.gov (United States)

    Byrdin, Martin; Lukacs, Andras; Thiagarajan, Viruthachalam; Eker, André P M; Brettel, Klaus; Vos, Marten H

    2010-03-11

    The light-dependent DNA repair enzyme photolyase contains a unique evolutionary conserved triple tryptophan electron transfer chain (W382-W359-W306 in photolyase from E. coli) that bridges the approximately 15 A distance between the buried flavin adenine dinucleotide (FAD) cofactor and the surface of the protein. Upon excitation of the semireduced flavin (FADH(o)), electron transfer through the chain leads to formation of fully reduced flavin (FADH(-); required for DNA repair) and oxidation of the most remote tryptophan residue W306, followed by its deprotonation. The thus-formed tryptophanyl radical W306(o)(+) is reduced either by an extrinsic reductant or by reverse electron transfer from FADH(-). Altogether the kinetics of these charge transfer reactions span 10 orders of magnitude, from a few picoseconds to tens of milliseconds. We investigated electron transfer processes in the picosecond-nanosecond time window bridging the time domains covered by ultrafast pump-probe and "classical" continuous probe techniques. Using a recent dedicated setup, we directly show that virtually no absorption change between 300 ps and 10 ns occurs in wild-type photolyase, implying that no charge recombination takes place in this time window. In contrast, W306F mutant photolyase showed a partial absorption recovery with a time constant of 0.85 ns. In wild-type photolyase, the quantum yield of FADH(-) W306(o)(+) was found at 19 +/- 4%, in reference to the established quantum yield of the long-lived excited state of [Ru(bpy)(3)](2+). With this yield, the optical spectrum of the excited state of FADH(o) can be constructed from ultrafast spectroscopic data; this spectrum is dominated by excited state absorption extending from below 450 to 850 nm. The new experimental results, taken together with previous data, allow us to propose a detailed kinetic and energetic scheme of the electron transfer chain.

  1. Case studies of aerosol and ocean color retrieval using a Markov chain radiative transfer model and AirMSPI measurements

    Science.gov (United States)

    Xu, F.; Diner, D. J.; Seidel, F. C.; Dubovik, O.; Zhai, P.

    2014-12-01

    A vector Markov chain radiative transfer method was developed for forward modeling of radiance and polarization fields in a coupled atmosphere-ocean system. The method was benchmarked against an independent Successive Orders of Scattering code and linearized through the use of Jacobians. Incorporated with the multi-patch optimization algorithm and look-up-table method, simultaneous aerosol and ocean color retrievals were performed using imagery acquired by the Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) when it was operated in step-and-stare mode with 9 viewing angles ranging between ±67°. Data from channels near 355, 380, 445, 470*, 555, 660*, and 865* nm were used in the retrievals, where the asterisk denotes the polarimetric bands. Retrievals were run for AirMSPI overflights over Southern California and Monterey Bay, CA. For the relatively high aerosol optical depth (AOD) case (~0.28 at 550 nm), the retrieved aerosol concentration, size distribution, water-leaving radiance, and chlorophyll concentration were compared to those reported by the USC SeaPRISM AERONET-OC site off the coast of Southern California on 6 February 2013. For the relatively low AOD case (~0.08 at 550 nm), the retrieved aerosol concentration and size distribution were compared to those reported by the Monterey Bay AERONET site on 28 April 2014. Further, we evaluate the benefits of multi-angle and polarimetric observations by performing the retrievals using (a) all view angles and channels; (b) all view angles but radiances only (no polarization); (c) the nadir view angle only with both radiance and polarization; and (d) the nadir view angle without polarization. Optimized retrievals using different initial guesses were performed to provide a measure of retrieval uncertainty. Removal of multi-angular or polarimetric information resulted in increases in both parameter uncertainty and systematic bias. Potential accuracy improvements afforded by applying constraints on the surface

  2. Falling chains

    CERN Document Server

    Wong, C W; Wong, Chun Wa; Yasui, Kosuke

    2006-01-01

    The one-dimensional falling motion of a bungee chain suspended from a rigid support and of a chain falling from a resting heap on a table is studied. Their Lagrangians are found to contain no explicit time dependence. As a result, these falling chains are conservative systems. Each of their Lagrange's equations of motion is shown to contain a term that enforces energy conservation when masses are transferred between subchains. We show in particular that Cayley's 1857 energy nonconserving solution for a chain falling from a resting heap is incorrect because it neglects the energy gained when the transferred link is emitted by the emitting subchain. The maximum chain tension measured by Calkin and March for the falling bungee chain is given a simple if rough interpretation. In the simplified one-dimensional treatment, the kinetic energy of the center of mass of the falling bungee chain is found to be converted by the chain tension at the rigid support into the internal kinetic energy of the chain. However, as t...

  3. Calibration chain design based on integrating sphere transfer radiometer for SI-traceable on-orbit spectral radiometric calibration and its uncertainty analysis

    Science.gov (United States)

    Zhao, Wei-Ning; Fang, Wei; Sun, Li-Wei; Cui, Li-Hong; Wang, Yu-Peng

    2016-09-01

    In order to satisfy the requirement of SI-traceable on-orbit absolute radiation calibration transfer with high accuracy for satellite remote sensors, a transfer chain consisting of a fiber coupling monochromator (FBM) and an integrating sphere transfer radiometer (ISTR) was designed in this paper. Depending on the Sun, this chain based on detectors provides precise spectral radiometric calibration and measurement to spectrometers in the reflective solar band (RSB) covering 300-2500 nm with a spectral bandwidth of 0.5-6 nm. It shortens the traditional chain based on lamp source and reduces the calibration uncertainty from 5% to 0.5% by using the cryogenic radiometer in space as a radiometric benchmark and trap detectors as secondary standard. This paper also gives a detailed uncertainty budget with reasonable distribution of each impact factor, including the weak spectral signal measurement with uncertainty of 0.28%. According to the peculiar design and comprehensive uncertainty analysis, it illustrates that the spectral radiance measurement uncertainty of the ISTR system can reach to 0.48%. The result satisfies the requirements of SI-traceable on-orbit calibration and has wider significance for expanding the application of the remote sensing data with high-quality. Project supported by the National Natural Science Foundation of China (Grant No. 41474161) and the National High-Technology Program of China (Grant No. 2015AA123703).

  4. Adenoviral vector-mediated gene transfer of IL-13Ralpha2 chain followed by IL-13 cytotoxin treatment offers potent targeted therapy for cytotoxin-resistant cancers.

    Science.gov (United States)

    Saito, Makoto; Murata, Takashi; Watanabe, Ken; Kawakami, Koji; Suzuki, Motoyoshi; Koji, Takehiko; Puri, Raj K; Kitazato, Kaio; Kobayashi, Nobuyuki

    2005-08-10

    Previous studies demonstrated that IL-13Ralpha2 chain-overexpressing cancer cells were highly sensitive to IL-13 cytotoxin (IL13-PE38QQR) and could be targeted by cytotoxin treatment. However, the majority of human tumors do not express high levels of IL-13Ralpha2 chain. To expand the IL-13 cytotoxin-mediated cancer targeting therapy, we combined cytotoxin treatment with gene transfer of IL-13Ralpha2 chain. We constructed a recombinant adenoviral vector carrying the human IL-13Ralpha2 gene (Ad-IL-13Ralpha2), which expresses high levels of IL-13Ralpha2 chain on infected cells. Human cancer cell lines A549 and HOS, which originally show no IL-13Ralpha2 expression and little sensitivity to IL-13 cytotoxin, were effectively converted to become sensitive to this cytotoxin after Ad-IL-13Ralpha2 infection. The CC(50) of IL-13 cytotoxin for Ad-IL-13Ralpha2-infected A549 cells was 500 ng/ml. We also examined the antitumor activity of IL-13 cytotoxin in an established xenograft model of cytotoxin-resistant human lung tumor. Only a single i.t. injection of Ad-IL-13Ralpha2 markedly enhanced the sensitivity of established tumors to IL-13 cytotoxin treatment; furthermore, this antitumor effect was significantly sustained for more than 1 month after the last treatment with IL-13 cytotoxin. Taken together, these results suggest the combination of adenoviral vector-mediated IL-13Ralpha2 gene transfer and IL-13 cytotoxin administration can be an effective targeting approach for several types of IL-13 cytotoxin-resistant cancers which show no or little expression of IL-13Ralpha2 chain.

  5. Toxicity and transfer of polyvinylpyrrolidone-coated silver nanowires in an aquatic food chain consisting of algae, water fleas, and zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Yooeun; An, Youn-Joo, E-mail: anyjoo@konkuk.ac.kr

    2016-04-15

    Highlights: • Trophic transfer of silver nanowires (AgNWs) was studied in an aquatic food chain. • The transfer of AgNWs from algae to fish via water fleas was observed. • Toxicity of long AgNWs on aquatic organisms is higher than that of short ones. • AgNWs damage the gut of water fleas and may cause undernourishment. • Quantity of lipid droplets increased with increasing exposure concentration. - Abstract: Nanomaterials of various shapes and dimensions are widely used in the medical, chemical, and electronic industries. Multiple studies have reported the ecotoxicological effects of nanaoparticles when released in aquatic and terrestrial ecosystems; however, information on the toxicity of silver nanowires (AgNWs) to freshwater organisms and their transfer through the food webs is limited. In the present study, we aimed to evaluate the toxicity of 10- and 20-μm-long AgNWs to the alga Chlamydomonas reinhardtii, the water flea Daphnia magna, and the zebrafish and study their movement through this three-species food chain using a variety of qualitative and quantitative methods as well as optical techniques. We found that AgNWs directly inhibited the growth of algae and destroyed the digestive organs of water fleas. The results showed that longer AgNWs (20 μm) were more toxic than shorter ones (10 μm) to both algae and water fleas, but shorter AgNWs were accumulated more than longer ones in the body of the fish. Overall, this study suggests that AgNWs are transferred through food chains, and that they affect organisms at higher trophic levels, potentially including humans. Therefore, further studies that take into account environmental factors, food web complexity, and differences between nanomaterials are required to gain better understanding of the impact of nanomaterials on natural communities and human health.

  6. Building Pathways to Transfer: Community Colleges That Break the Chain of Failure for Students of Color. Policy Brief

    Science.gov (United States)

    Civil Rights Project / Proyecto Derechos Civiles, 2012

    2012-01-01

    This study followed all freshman community college students in California who had demonstrated the intent to transfer from 1996, 1997, and 1998. Outcomes were assessed for each of the three entering cohorts after six years (2002-2004) and students were linked with their high schools of origin and the 4-year colleges to which they transferred. The…

  7. Unraveling the evolutionary history of the phosphoryl-transfer chain of the phosphoenolpyruvate:phosphotransferase system through phylogenetic analyses and genome context

    Directory of Open Access Journals (Sweden)

    Zúñiga Manuel

    2008-05-01

    Full Text Available Abstract Background The phosphoenolpyruvate phosphotransferase system (PTS plays a major role in sugar transport and in the regulation of essential physiological processes in many bacteria. The PTS couples solute transport to its phosphorylation at the expense of phosphoenolpyruvate (PEP and it consists of general cytoplasmic phosphoryl transfer proteins and specific enzyme II complexes which catalyze the uptake and phosphorylation of solutes. Previous studies have suggested that the evolution of the constituents of the enzyme II complexes has been driven largely by horizontal gene transfer whereas vertical inheritance has been prevalent in the general phosphoryl transfer proteins in some bacterial groups. The aim of this work is to test this hypothesis by studying the evolution of the phosphoryl transfer proteins of the PTS. Results We have analyzed the evolutionary history of the PTS phosphoryl transfer chain (PTS-ptc components in 222 complete genomes by combining phylogenetic methods and analysis of genomic context. Phylogenetic analyses alone were not conclusive for the deepest nodes but when complemented with analyses of genomic context and functional information, the main evolutionary trends of this system could be depicted. Conclusion The PTS-ptc evolved in bacteria after the divergence of early lineages such as Aquificales, Thermotogales and Thermus/Deinococcus. The subsequent evolutionary history of the PTS-ptc varied in different bacterial lineages: vertical inheritance and lineage-specific gene losses mainly explain the current situation in Actinobacteria and Firmicutes whereas horizontal gene transfer (HGT also played a major role in Proteobacteria. Most remarkably, we have identified a HGT event from Firmicutes or Fusobacteria to the last common ancestor of the Enterobacteriaceae, Pasteurellaceae, Shewanellaceae and Vibrionaceae. This transfer led to extensive changes in the metabolic and regulatory networks of these bacteria

  8. Factors affecting the concentration in seven-spotted ladybirds (Coccinella septempunctata L.) of Cd and Zn transferred through the food chain

    Energy Technology Data Exchange (ETDEWEB)

    Green, I.D., E-mail: igreen@bournemouth.ac.u [Centre for Conservation Ecology and Environmental Change, School of Conservation Sciences, Bournemouth University, Talbot Campus, Poole, Dorset BH12 5BB (United Kingdom); Diaz, A., E-mail: adiaz@bournemouth.ac.u [Centre for Conservation Ecology and Environmental Change, School of Conservation Sciences, Bournemouth University, Talbot Campus, Poole, Dorset BH12 5BB (United Kingdom); Tibbett, M., E-mail: mark.tibbett@uwa.edu.a [Centre for Land Rehabilitation, School of Earth and Environment, Faculty of Natural and Agricultural Sciences, University of Western Australia, 35 Stirling Highway, Crawley WA 6009 (Australia)

    2010-01-15

    The transfer of Cd and Zn from soils amended with sewage sludge was followed through a food chain consisting of wheat, aphids and the predator Coccinella septempunctata. Multiple regression models were generated to predict the concentrations of Cd and Zn in C. septempunctata. No significant model could be generated for Cd, indicting that the concentration of this metal was maintained within relatively narrow limits. A model predicting 64% of the variability in the Zn concentration of C. septempunctata was generated from of the concentration of Zn in the diet, time and rate of Zn consumption. The results suggest that decreasing the rate of food consumption is an effective mechanism to prevent the accumulation of Zn and that the availability of Zn in the aphid prey increased with the concentration in the aphids. The results emphasise the importance of using ecologically relevant food chains and exposure pathways during ecotoxicological studies. - Arthropod predators can regulate trace metal body burden through physiological and behavioural mechanisms.

  9. Measuring distances within unfolded biopolymers using fluorescence resonance energy transfer: The effect of polymer chain dynamics on the observed fluorescence resonance energy transfer efficiency

    Science.gov (United States)

    Makarov, Dmitrii E.; Plaxco, Kevin W.

    2009-01-01

    Recent years have seen a number of investigations in which distances within unfolded proteins, polypeptides, and other biopolymers are probed via fluorescence resonance energy transfer, a method that relies on the strong distance dependence of energy transfer between a pair of dyes attached to the molecule of interest. In order to interpret the results of such experiments it is commonly assumed that intramolecular diffusion is negligible during the excited state lifetime. Here we explore the conditions under which this “frozen chain” approximation fails, leading to significantly underestimated donor-acceptor distances, and describe a means of correcting for polymer dynamics in order to estimate these distances more accurately. PMID:19725638

  10. Transfer of radiocaesium from contaminated bottom sediments to marine organisms through benthic food chains in post-Fukushima and post-Chernobyl periods

    Science.gov (United States)

    Bezhenar, Roman; Jung, Kyung Tae; Maderich, Vladimir; Willemsen, Stefan; de With, Govert; Qiao, Fangli

    2016-05-01

    After the earthquake and tsunami on 11 March 2011 damaged the Fukushima Dai-ichi Nuclear Power Plant (FDNPP), an accidental release of a large amount of radioactive isotopes into both the air and the ocean occurred. Measurements provided by the Japanese agencies over the past 5 years show that elevated concentrations of 137Cs still remain in sediments, benthic organisms, and demersal fishes in the coastal zone around the FDNPP. These observations indicate that there are 137Cs transfer pathways from bottom sediments to the marine organisms. To describe the transfer quantitatively, the dynamic food chain biological uptake model of radionuclides (BURN) has been extended to include benthic marine organisms. The extended model takes into account both pelagic and benthic marine organisms grouped into several classes based on their trophic level and type of species: phytoplankton, zooplankton, and fishes (two types: piscivorous and non-piscivorous) for the pelagic food chain; deposit-feeding invertebrates, demersal fishes fed by benthic invertebrates, and bottom omnivorous predators for the benthic food chain; crustaceans, mollusks, and coastal predators feeding on both pelagic and benthic organisms. Bottom invertebrates ingest organic parts of bottom sediments with adsorbed radionuclides which then migrate up through the food chain. All organisms take radionuclides directly from water as well as food. The model was implemented into the compartment model POSEIDON-R and applied to the north-western Pacific for the period of 1945-2010, and then for the period of 2011-2020 to assess the radiological consequences of 137Cs released due to the FDNPP accident. The model simulations for activity concentrations of 137Cs in both pelagic and benthic organisms in the coastal area around the FDNPP agree well with measurements for the period of 2011-2015. The decrease constant in the fitted exponential function of simulated concentration for the deposit-feeding invertebrates (0.45 yr-1

  11. Kinetic performance and energy profile in a roller coaster electron transfer chain: a study of modified tetraheme-reaction center constructs.

    Science.gov (United States)

    Alric, Jean; Lavergne, Jérôme; Rappaport, Fabrice; Verméglio, André; Matsuura, Katsumi; Shimada, Keizo; Nagashima, Kenji V P

    2006-03-29

    In many electron-transfer proteins, the arrangement of cofactors implies a succession of uphill and downhill steps. The kinetic implications of such arrangements are examined in the present work, based on a study of chimeric photosynthetic reaction centers obtained by expressing the tetraheme subunit from Blastochloris viridis in another purple bacterium, Rubrivivax gelatinosus. Site-directed mutations of the environment of heme c559, which is the immediate electron donor to the primary donor P, induced modifications of this heme's midpoint potential over a range of 400 mV. This resulted in shifts of the apparent midpoint potentials of the neighboring carriers, yielding estimates of the interactions between redox centers. At both extremities of the explored range, the energy profile of the electron-transfer chain presented an additional uphill step, either downstream or upstream from c559. These modifications caused conspicuous changes of the electron-transfer rate across the tetraheme subunit, which became approximately 100-fold slower in the mutants where the midpoint potential of c559 was lowest. A theoretical analysis of the kinetics is presented, predicting a displacement of the rate-limiting step when lowering the potential of c559. A reasonable agreement with the data was obtained when combining this treatment with the rates predicted by electron transfer theory for the individual rate constants.

  12. Dissection of the triple tryptophan electron transfer chain in Escherichia coli DNA photolyase: Trp382 is the primary donor in photoactivation.

    Science.gov (United States)

    Byrdin, Martin; Eker, André P M; Vos, Marten H; Brettel, Klaus

    2003-07-22

    In Escherichia coli photolyase, excitation of the FAD cofactor in its semireduced radical state (FADH*) induces an electron transfer over approximately 15 A from tryptophan W306 to the flavin. It has been suggested that two additional tryptophans are involved in an electron transfer chain FADH* FADH* decayed with a time constant tau approximately 26 ps to fully reduced flavin and a tryptophan cation radical. In W382F mutant photolyase, the excited flavin was much longer lived (tau approximately 80 ps), and no significant amount of product was detected. We conclude that, in WT photolyase, excited FADH* is quenched by electron transfer from W382. On a millisecond scale, a product state with extremely low yield ( approximately 0.5% of WT) was detected in W382F mutant photolyase. Its spectral and kinetic features were similar to the fully reduced flavin/neutral tryptophan radical state in WT photolyase. We suggest that, in W382F mutant photolyase, excited FADH* is reduced by W359 at a rate that competes only poorly with the intrinsic decay of excited FADH* (tau approximately 80 ps), explaining the low product yield. Subsequently, the W359 cation radical is reduced by W306. The rate constants of electron transfer from W382 to excited FADH* in WT and from W359 to excited FADH* in W382F mutant photolyase were estimated and related to the donor-acceptor distances.

  13. Role of the middle residue in the triple tryptophan electron transfer chain of DNA photolyase: ultrafast spectroscopy of a Trp-->Phe mutant.

    Science.gov (United States)

    Lukacs, Andras; Eker, André P M; Byrdin, Martin; Villette, Sandrine; Pan, Jie; Brettel, Klaus; Vos, Marten H

    2006-08-17

    Photoreduction of the semi-reduced flavin adenine dinucleotide cofactor FADH* in DNA photolyase from Escherichia coli into FADH- involves three tryptophan (W) residues that form a closely spaced electron-transfer chain FADH*-W382-W359-W306. To investigate this process, we have constructed a mutant photolyase in which W359 is replaced by phenylalanine (F). Monitoring its photoproducts by femtosecond spectroscopy, the excited-state FADH* was found to decay in approximately 30 ps, similar as in wild type (WT) photolyase. In contrast to WT, however, in W359F mutant photolyase the ground-state FADH* fully recovered virtually concomitantly with the decay of its excited state and, despite the presence of the primary electron donor W382, no measurable flavin reduction was observed at any time. Thus, W359F photolyase appears to behave like many other flavoproteins, where flavin excited states are quenched by very short-lived oxidation of aromatic residues. Our analysis indicates that both charge recombination of the primary charge separation state FADH-W382*+ and (in WT) electron transfer from W359 to W382*+ occur with time constants FADH* electron-transfer step. Our results provide a first experimental indication that electron transfer between aromatic residues can take place on the time scale of approximately 10(-12) s.

  14. Reliability Measurement for Software with Variable Length Markov Control Transfer Chain%VLMC控制流软件可靠性度量方法

    Institute of Scientific and Technical Information of China (English)

    赵瑞曼; 潘冠华; 方建勇

    2014-01-01

    The classical software reliability model of Cheung based on architecture analysis is imperfect when applied to soft-ware which has non-uniqueness terminal node because of ideal assumptions. In order to handle this problem, an improved model is established through two improvement as follows:first, probability matrix of control transfer from start node to other inner nodes in a given software is computed independently of control transfer within inner nodes on the assumptions that the start node is inaccessible to control transfer from any inner nodes;and then, probability matrixes of control transfer within in-ner nodes are reconfigured by weaken the difference between inner nodes and ending nodes. In order to measure the reliability of software with VLMC control transfer flow, the variable length Markov control sequence chain is converted to simple Markov chain by node expansion and conditional transfer probability redistribution. By using deductive inference, a formal proof for the new model is given in this essay. In the end, effectiveness and simplicity of the proposed method is verified by a software example.%针对现有软件可靠性模型普遍不适用于实际软件的问题,分析了软件内部模块间控制转移机理,通过分离入口模块,提取一阶控制转移概率矩阵;弱化内部模块与出口模块间差异,重构二阶以上转移概率矩阵,在改进Cheung模型的基础上建立一个更符合软件实际的可靠性度量模型。针对变阶依赖( VLMC)控制转移导致的可靠性度量难问题,通过对导致复杂依赖的多入多出模块进行节点扩展,将VLMC控制流转化为Markov链,利用所建立的软件可靠性模型对VLMC控制流软件进行可靠性度量。研究利用演绎推理对所建立模型进行了正确性形式化证明。最后给出了方法的实例验证。

  15. Synthesis of CdSe quantum dots using various long-chain fatty acids and their phase transfer.

    Science.gov (United States)

    Zhang, Qiang; Zhang, Aiyu; Yang, Ping; Shen, Jianxing

    2013-06-01

    Monodispersed colloidal photoluminescent CdSe quantum dots (QDs) were synthesized via an organic approach by using cadmium oxide and elemental selenium as precursors, and long-chain fatty acids as surface ligands. The hydrocarbon chain length of the fatty acid was adjusted to investigate the effect on CdSe QDs. The fatty acid ligands with different hydrocarbon chain lengths showed an apparent effect on the nanocrystal nucleation and growth which is the key controlling the size, size distribution and crystal structure of resulting CdSe QDs. This effect was attributable to the steric hindrance of different hydrocarbon length of the fatty acids, which affected the reactivity of the monomers and nanocrystals during the nanocrystal nucleation and growth. The water-soluble CdSe QDs were obtained by encapsulating the CdSe ODs in oil phase with amphiphilic poly(styrene-co-maleic anhydride) (PSMA)-ethanolamine (EA) polymers, which made it possible for further applications of the CdSe QDs in aqueous environment such as surface functionalization for biological labeling and application in photocatalysis and photosensitization.

  16. Diagonalization of transfer matrix of supersymmetry $u_q(\\hat{sl}(m+1|n+1))$ chain with a boundary

    CERN Document Server

    Kojima, Takeo

    2012-01-01

    We study the supersymmetry $U_q(\\hat{sl}(M+1|N+1))$ analogue of the supersymmetric t-J model with a boundary, in the framework of the algebraic analysis method. We diagonalize the commuting transfer matrix by using the bosonization of the vertex operator associated with the quantum affine supersymmetry.

  17. Analysis of Air Cargo Transfer Service Chain at Pudong International Airport%浦东国际机场货运中转服务链分析

    Institute of Scientific and Technical Information of China (English)

    刘锐; 崔诚靓; 陈川

    2015-01-01

    Air cargo transfer involves several participants in its operation process, including ship pers, freight forwarders, airport cargo terminal, airlines, customs and other regulatory agencies. All of the related participants constitute the entire service chain of air cargo transfer, making the air transport continuous and convenient. Based on field research into the related enterprises, this study summarizes the developing situation about the air cargo transfer at Pudong International Airport as well as the related appeals proposed by the relevant partici pants, points out the problems at Pudong International Airport and presents some suggestions from the perspec tive of service chain.%现代航空货物中转运输在其运营过程中涉及到许多参与方,包括货主、货代、机场货站、航空公司以及海关等监管机构,所有这一系列参与方构成了整个货运中转服务链条,维系着航空运输的连续性和快捷性. 在立足对浦东机场各个货运相关参与方的实地调研的基础上,通过收集整理国外枢纽机场和相关企业的资料,分析总结浦东机场各个参与方的发展现状,梳理了参与方对中转联程运输的相关诉求,指出了浦东机场货运中转服务链中所存在的相关问题,最后从服务链的角度提出改善浦东机场货运中转的建议.

  18. TERMINATION AND TRANSFER OF THE CHAIN RADICALS IN THE POLYMERIZATION OF ACRYLONITRILE INITIATED BY VANADIUM(V)-THIOUREA REDOX SYSTEM

    Institute of Scientific and Technical Information of China (English)

    WU Jinyuan; YANG Chaoxiong; WU Yuxian

    1990-01-01

    The dependence of the molecular weights on the concentration of reactants in the polymerization of acrylonitrile initiated by vanadium (V)-thiourea red ox system has been investigated. It was found that the molecular weights of the polymer change nonlinearly with increasing concentrations of nitric acid and thiourea. Probably, the composition of the complexes exert a great influence on the chain initiation and termination. The reaction of "complextermination " gives rise to the decrease of the molecular weights markedly while the concentrations of thiourea and vanadium (V)in the range from one to three molar ratios.

  19. Charge Transfer Dissociation (CTD) Mass Spectrometry of Peptide Cations: Study of Charge State Effects and Side-Chain Losses

    Science.gov (United States)

    Li, Pengfei; Jackson, Glen P.

    2017-01-01

    1+, 2+, and 3+ precursors of substance P and bradykinin were subjected to helium cation irradiation in a 3D ion trap mass spectrometer. Charge exchange with the helium cations produces a variety of fragment ions, the number and type of which are dependent on the charge state of the precursor ions. For 1+ peptide precursors, fragmentation is generally restricted to C-CO backbone bonds (a and x ions), whereas for 2+ and 3+ peptide precursors, all three backbone bonds (C-CO, C-N, and N-Cα) are cleaved. The type of backbone bond cleavage is indicative of possible dissociation channels involved in CTD process, including high-energy, kinetic-based, and ETD-like pathways. In addition to backbone cleavages, amino acid side-chain cleavages are observed in CTD, which are consistent with other high-energy and radical-mediated techniques. The unique dissociation pattern and supplementary information available from side-chain cleavages make CTD a potentially useful activation method for the structural study of gas-phase biomolecules.

  20. “土地流转”政策下农产品供应链的重构%Land Transfer and the Reconstruction of Agricultural Supply Chain

    Institute of Scientific and Technical Information of China (English)

    江许胜

    2012-01-01

    With the popularization of local land transfer, the level of agricultural industrialization has been gradually improved , agricultural logistics has an unprecedented development. But the traditional competition still remains among all the main logistics operators due to the lack of appropriate mechanism of convergence of profit, which leads to the high cost of logistics operation. In the prliminary study, the research group analyzed opportunities and challenges of agricultural logistics development on the basis of the land transfer, and now proposes constructing the agricultural supply chain to manage logistics with the management idea of supply chain so as to explore a new way for the development of the agricultural logistics.%随着各地土地流转的推广普及,农业产业化水平不断提高,农业物流得到了前所未有的发展,但各物流经营主体之间仍保持着传统的竞争关系,缺乏适宜的利益衔接机制,物流运作成本居高不下。在前期研究中,课题组分析了土地流转对农业物流发展的机遇和挑战,在此基础之上,提出了构建新型农产品供应链的想法,用供应链管理的思想管理物流,力求为农产品物流的发展探寻一个新途径。

  1. 基于供应链知识转移的企业技术创新能力提升%Technology Innovation Ability Improving of Enterprises based on the Knowledge Transfer on Supply Chain

    Institute of Scientific and Technical Information of China (English)

    朱简

    2016-01-01

    Technological innovation capability is mainly reflected the ability of knowledge innovation, enterprise innovation to achieve knowledge, it must obtain new knowledge and technology to the outside, to carry out knowledge transfer activities. Enterprise development in the midst of a certain supply chain systems, knowledge transfer between the performance of the supply chain will affect business knowledge innovation, thereby affecting the technological innovation capability of enterprises. Article about the relationship between supply chain knowledge transfer and enterprise technological innovation capability be-tween discussions, in-depth analysis of the factors affecting supply chain knowledge transfer, knowledge transfer out of the main supply chain companies, knowledge transfer and knowledge transfer media scene three aspects the upgrade path of tech-nological innovation capability of enterprises.%企业技术创新能力集中表现在知识创新能力,而企业要实现知识创新,必须向外部获取新的知识和技术,开展知识转移活动。企业发展处于一定的供应链系统之中,供应链之间的知识转移绩效将影响企业知识创新,从而影响企业的技术创新能力。本文围绕供应链知识转移与企业技术创新能力之间的关系分析供应链知识转移的影响因素,分别从供应链企业的知识转移主体、知识转移情景和知识转移媒介三个方面提出了企业技术创新能力的提升路径。

  2. Nonlinear calibration transfer based on hierarchical Bayesian models and Lagrange Multipliers: Error bounds of estimates via Monte Carlo - Markov Chain sampling.

    Science.gov (United States)

    Seichter, Felicia; Vogt, Josef; Radermacher, Peter; Mizaikoff, Boris

    2017-01-25

    The calibration of analytical systems is time-consuming and the effort for daily calibration routines should therefore be minimized, while maintaining the analytical accuracy and precision. The 'calibration transfer' approach proposes to combine calibration data already recorded with actual calibrations measurements. However, this strategy was developed for the multivariate, linear analysis of spectroscopic data, and thus, cannot be applied to sensors with a single response channel and/or a non-linear relationship between signal and desired analytical concentration. To fill this gap for a non-linear calibration equation, we assume that the coefficients for the equation, collected over several calibration runs, are normally distributed. Considering that coefficients of an actual calibration are a sample of this distribution, only a few standards are needed for a complete calibration data set. The resulting calibration transfer approach is demonstrated for a fluorescence oxygen sensor and implemented as a hierarchical Bayesian model, combined with a Lagrange Multipliers technique and Monte-Carlo Markov-Chain sampling. The latter provides realistic estimates for coefficients and prediction together with accurate error bounds by simulating known measurement errors and system fluctuations. Performance criteria for validation and optimal selection of a reduced set of calibration samples were developed and lead to a setup which maintains the analytical performance of a full calibration. Strategies for a rapid determination of problems occurring in a daily calibration routine, are proposed, thereby opening the possibility of correcting the problem just in time.

  3. Fe2+-Ti4+ vs. Fe2+-Fe3+ charge-transfer and short-range order in single chains of face-sharing octahedra: ellenbergerite and dumortierite

    Science.gov (United States)

    Chopin, C.; Langer, K.; Khomenko, V.

    2009-04-01

    In zoned pyrope megacrysts from the Dora-Maira UHP terrane, new, dark-violet colour varieties of the hexagonal, high-pressure silicate ellenbergerite extend the range of known Fe contents for this mineral from 0-0.1 to 0-0.4 atom pfu, for Ti contents commonly in the range 0.2-0.4 pfu. The new varieties show an extremely intense pleochroism, colourless for E perpendicular to c to deep Prussian blue for E//c, as compared to colourless to lilac or reddish purple for classical Fe-poor ellenbergerite. These features were the incentive for an electronic absorption spectroscopic study and a reappraisal of the interpretation of the charge transfers (CT), colour and ordering schemes in this group and the structurally related borosilicate dumortierite. Both structures are characterized by the presence of infinite single chains of face-sharing, partly vacant octahedra along the 6-fold screw axis and pseudo-hexad axis, respectively, in which the Fe and Ti atoms are partitioned. In the spectra of Fe-poor ellenbergerite, the presence of a single Fe2+-Ti4+ CT band near 19000 cm˘1 was taken as evidence for complete short-range ordering of Mg(Fe), Ti and vacancies in the octahedral single chain [1]. The E//c spectra of Fe-rich ellenbergerite show the same absorption band near 19000 cm˘1 but consistently flanked by another CT band near 14000 cm˘1 , the intensity of which increases with total Fe content. The latter is similar to the 12400 cm˘1 CT band observed as the single feature in E//c spectra of the isotructural (Ti-free and Fe-bearing) phosphoellenbergerite, and clearly assigned to Fe2+-Fe3+ CT in the octahedral single chain [1]. The same colour pattern occurs in the dumortierite group, with red Fe-poor, Ti-rich crystals showing a single CT band near 20000 cm˘1, blue Ti-poor crystals showing a single CT band near 16500 cm˘1, and violet Fe- and Ti-rich crystals showing a combination of the two bands [2]. In the light of the new data, we reinterpret the dumortierite colour

  4. Chain Dynamics, Relaxation Times, and Conductivities of Bithiophene--Acene Copolymers Measured Using High Frequency Saturation Transfer EPR.

    Science.gov (United States)

    Fraind, Alicia M; Ryzhkov, Lev R; Tovar, John D

    2016-02-11

    We present a study to probe the formation of localized aromatic sextets and their effects on the charge transport properties in polymers with acene cores. Bithiophene-acene copolymers containing benzene, naphthalene, or anthracene as acene cores were synthesized using Yamamoto polymerization. Drop-casted polymer films were chemically doped and analyzed using high frequency saturation transfer EPR (HF ST-EPR), a method which has proven useful in the study of conducting polymers. The spin-spin and spin-lattice relaxation times were determined for these polymers at low temperatures (4 to 20 K) and used to obtain inter- and intrachain spin diffusion rates and conductivities. Similar interchain spin diffusion rates were seen across all polymer systems; however, anthracene containing polymer poly(hexylTTATT) was found to have the largest intrachain spin diffusion rate. The poly(hexylTTATT) intrachain spin diffusion rate may be artificially high if the anthracene ring restricts the diffusion of spin to the hexylated quaterthiophene segment in poly(hexylTTATT) whereas the spins diffuse through the acene cores in the benzene and naphthalene derivatives. Alternatively, as both the spin diffusion rates and conductivities vary unpredictably with temperature, it is possible that the π-electron localization previously seen in the anthracene core could be relieved at lower temperatures.

  5. Effect of ageing and ischemia on enzymatic activities linked to Krebs' cycle, electron transfer chain, glutamate and aminoacids metabolism of free and intrasynaptic mitochondria of cerebral cortex.

    Science.gov (United States)

    Villa, Roberto Federico; Gorini, Antonella; Hoyer, Siegfried

    2009-12-01

    The effect of ageing and the relationships between the catalytic properties of enzymes linked to Krebs' cycle, electron transfer chain, glutamate and aminoacid metabolism of cerebral cortex, a functional area very sensitive to both age and ischemia, were studied on mitochondria of adult and aged rats, after complete ischemia of 15 minutes duration. The maximum rate (Vmax) of the following enzyme activities: citrate synthase, malate dehydrogenase, succinate dehydrogenase for Krebs' cycle; NADH-cytochrome c reductase as total (integrated activity of Complex I-III), rotenone sensitive (Complex I) and cytochrome oxidase (Complex IV) for electron transfer chain; glutamate dehydrogenase, glutamate-oxaloacetate-and glutamate-pyruvate transaminases for glutamate metabolism were assayed in non-synaptic, perikaryal mitochondria and in two populations of intra-synaptic mitochondria, i.e., the light and heavy mitochondrial fraction. The results indicate that in normal, steady-state cerebral cortex, the value of the same enzyme activity markedly differs according (a) to the different populations of mitochondria, i.e., non-synaptic or intra-synaptic light and heavy, (b) and respect to ageing. After 15 min of complete ischemia, the enzyme activities of mitochondria located near the nucleus (perikaryal mitochondria) and in synaptic structures (intra-synaptic mitochondria) of the cerebral tissue were substantially modified by ischemia. Non-synaptic mitochondria seem to be more affected by ischemia in adult and particularly in aged animals than the intra-synaptic light and heavy mitochondria. The observed modifications in enzyme activities reflect the metabolic state of the tissue at each specific experimental condition, as shown by comparative evaluation with respect to the content of energy-linked metabolites and substrates. The derangements in enzyme activities due to ischemia is greater in aged than in adult animals and especially the non-synaptic and the intra-synaptic light

  6. Food-chain transfer of zinc from contaminated Urtica dioica and Acer pseudoplatanus L. to the aphids Microlophium carnosum and Drepanosiphum platanoidis Schrank

    Energy Technology Data Exchange (ETDEWEB)

    Sinnett, Danielle, E-mail: danielle.sinnett@forestry.gsi.gov.u [Centre for Forestry and Climate Change, Forest Research, Alice Holt Lodge, Farnham, Surrey GU10 4LH (United Kingdom); Department of Soil Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Reading RG6 6DW (United Kingdom); Hutchings, Tony R., E-mail: tony.hutchings@forestry.gsi.gov.u [Centre for Forestry and Climate Change, Forest Research, Alice Holt Lodge, Farnham, Surrey GU10 4LH (United Kingdom); Hodson, Mark E., E-mail: m.e.hodson@reading.ac.u [Department of Soil Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Reading RG6 6DW (United Kingdom)

    2010-01-15

    This study examines the food-chain transfer of Zn from two plant species, Urtica dioica (stinging nettle) and Acer pseudoplatanus (sycamore maple), into their corresponding aphid species, Microlophium carnosum and Drepanosiphum platanoidis. The plants were grown in a hydroponic system using solutions with increasing concentrations of Zn from 0.02 to 41.9 mg Zn/l. Above-ground tissue concentrations in U. dioica and M. carnosum increased with increasing Zn exposure (p < 0.001). Zn concentrations in A. pseudoplatanus also increased with solution concentration from the control to the 9.8 mg Zn/l solution, above which concentrations remained constant. Zn concentrations in both D. platanoidis and the phloem tissue of A. pseudoplatanus were not affected by the Zn concentration in the watering solution. It appears that A. pseudoplatanus was able to limit Zn transport in the phloem, resulting in constant Zn exposure to the aphids. Zn concentrations in D. platanoidis were around three times those in M. carnosum. - Concentrations of Zn in two aphid species are dependant on species and exposure.

  7. Asymmetric Synthesis and Binding Study of New Long-Chain HPA-12 Analogues as Potent Ligands of the Ceramide Transfer Protein CERT.

    Science.gov (United States)

    Ďuriš, Andrej; Daïch, Adam; Santos, Cécile; Fleury, Laurence; Ausseil, Frédéric; Rodriguez, Frédéric; Ballereau, Stéphanie; Génisson, Yves; Berkeš, Dušan

    2016-05-01

    A series of 12 analogues of the Cer transfer protein (CERT) antagonist HPA-12 with long aliphatic chains were prepared as their (1R,3S)-syn and (1R,3R)-anti stereoisomers from pivotal chiral oxoamino acids. The enantioselective access to these intermediates as well as their ensuing transformation relied on a practical crystallization-induced asymmetric transformation (CIAT) process. Sonogashira coupling followed by triple bond reduction and thiophene ring hydrodesulfurization (HDS) into the corresponding alkane moieties was then implemented to complete the synthetic routes delivering the targeted HPA-12 analogues in concise 4- to 6-step reaction sequences. Ten compounds were evaluated regarding their ability to bind to the CERT START domain by using the recently developed time-resolved FRET-based homogeneous (HTR-FRET) binding assay. The introduction of a lipophilic appendage on the phenyl moiety led to an overall 10- to 1000-fold enhancement of the protein binding, with the highest effect being observed for a n-hexyl residue in the meta position. The importance of the phenyl ring for the activity was indicated by the reduced potency of the 3-deoxyphytoceramide aliphatic analogues. The 1,3-syn stereoisomers were systematically more potent than their 1,3-anti analogues. In silico studies were used to rationalized these trends, leading to a model of protein recognition coherent with the stronger binding of (1R,3S)-syn HPAs.

  8. 100-N Area Strontium-90 Treatability Demonstration Project: Food Chain Transfer Studies for Phytoremediation Along the 100-N Columbia River Riparian Zone

    Energy Technology Data Exchange (ETDEWEB)

    Fellows, Robert J.; Fruchter, Jonathan S.; Driver, Crystal J.

    2009-04-01

    Strontium-90 (90Sr) exceeds the U.S. Environmental Protection Agency’s drinking water standards for groundwater (8 picocuries/L) by as much as a factor of 1000 at several locations within the Hanford 100-N Area and along the 100-N Area Columbia River shoreline). Phytoextraction, a managed remediation technology in which plants or integrated plant/rhizosphere systems are employed to phytoextract and/or sequester 90Sr, is being considered as a potential remediation system along the riparian zone of the Columbia River as part of a treatment train that includes an apatite barrier to immobilize groundwater transport of 90Sr. Phytoextraction would employ coyote willow (Salix exigua) to extract 90Sr from the vadose zone soil and aquifer sediments (phytoextraction) and filter 90Sr (rhizofiltration) from the shallow groundwater along the riparian zone of the Columbia River. The stem and foliage of coyote willows accumulating 90Sr may present not only a mechanism to remove the contaminant but also can be viewed as a source of nutrition for natural herbivores, therefore becoming a potential pathway for the isotope to enter the riparian food chain. Engineered barriers such as large and small animal fencing constructed around the field plot will control the intrusion of deer, rodents, birds, and humans. These efforts, however, will have limited effect on mobile phytophagous insects. Therefore, this study was undertaken to determine the potential for food chain transfer by insects prior to placement of the remediation technology at 100-N. Insect types include direct consumers of the sap or liquid content of the plants vascular system (xylem and phloem) by aphids as well as those that would directly consume the plant foliage such as the larvae (caterpillars) of Lepidoptera species. Heavy infestations of aphids feeding on the stems and leaves of willows growing in 90Sr-contaminated soil can accumulate a small amount (~0.15 ± 0.06%) of the total label removed from the soil by

  9. 基于QFD的供应链质量风险传递模型研究%The Transfer Model Investigation of QFD-based Supply Chain Quality Risk

    Institute of Scientific and Technical Information of China (English)

    颜忠娥

    2013-01-01

    The product quality risk have progressively transfer and downward expanding effect in supply chain environment. When a upstream enterprise in supply chain have quality fluctuations, the quality risk is presented as the deviations of downstream customer satisfaction directly. How to analyze and predict the transfer model and consequences of the customer satisfaction deviations induced by quality risk become the main content of the risk management of quality risk in the supply chain. The formation mechanism of supply chain quality risk is investigated in this paper. The model of quality of the supply chain based on quality function is estab-lished, and the quantitative analysis model of the supply chain quality risk transfer process is proposed.%  供应链环境下的产品质量风险具有逐级传递并向下扩大的趋势效应,当供应链上某节点企业发生质量波动时,质量风险的直接表现形式为下游顾客需求满意度发生偏差。分析与预测因质量风险所导致的顾客满意度偏差在供应链中的传递及影响后果,成为供应链质量风险管理研究的主要内容之一。基于此,分析了供应链质量风险形成机理,建立了基于质量功能展开的质量供需链模型,提出了供应链质量风险传递的定量分析模型。

  10. Electrospun regenerated cellulose nanofibrous membranes surface-grafted with polymer chains/brushes via the atom transfer radical polymerization method for catalase immobilization.

    Science.gov (United States)

    Feng, Quan; Hou, Dayin; Zhao, Yong; Xu, Tao; Menkhaus, Todd J; Fong, Hao

    2014-12-10

    In this study, an electrospun regenerated cellulose (RC) nanofibrous membrane with fiber diameters of ∼200-400 nm was prepared first; subsequently, 2-hydroxyethyl methacrylate (HEMA), 2-dimethylaminoethyl methacrylate (DMAEMA), and acrylic acid (AA) were selected as the monomers for surface grafting of polymer chains/brushes via the atom transfer radical polymerization (ATRP) method. Thereafter, four nanofibrous membranes (i.e., RC, RC-poly(HEMA), RC-poly(DMAEMA), and RC-poly(AA)) were explored as innovative supports for immobilization of an enzyme of bovine liver catalase (CAT). The amount/capacity, activity, stability, and reusability of immobilized catalase were evaluated, and the kinetic parameters (Vmax and Km) for immobilized and free catalase were determined. The results indicated that the respective amounts/capacities of immobilized catalase on RC-poly(HEMA) and RC-poly(DMAEMA) nanofibrous membranes reached 78 ± 3.5 and 67 ± 2.7 mg g(-1), which were considerably higher than the previously reported values. Meanwhile, compared to that of free CAT (i.e., 18 days), the half-life periods of RC-CAT, RC-poly(HEMA)-CAT, RC-poly(DMAEMA)-CAT, and RC-poly(AA)-CAT were 49, 58, 56, and 60 days, respectively, indicating that the storage stability of immobilized catalase was also significantly improved. Furthermore, the immobilized catalase exhibited substantially higher resistance to temperature variation (tested from 5 to 70 °C) and lower degree of sensitivity to pH value (tested from 4.0 and 10.0) than the free catalase. In particular, according to the kinetic parameters of Vmax and Km, the nanofibrous membranes of RC-poly(HEMA) (i.e., 5102 μmol mg(-1) min(-1) and 44.89 mM) and RC-poly(DMAEMA) (i.e., 4651 μmol mg(-1) min(-1) and 46.98 mM) had the most satisfactory biocompatibility with immobilized catalase. It was therefore concluded that the electrospun RC nanofibrous membranes surface-grafted with 3-dimensional nanolayers of polymer chains/brushes would be

  11. Effect of Chain Transfer Agents on the Water Absorbency of ST-AA-AM Absorbent%链转移剂对ST-AA-AM吸水剂吸水性能的影响

    Institute of Scientific and Technical Information of China (English)

    郭佳; 刘明华; 林春香

    2012-01-01

    Ascorbic acid,formic acid,isopropanol,sodium bisulfite were chosen as chain transfer agents in the preparation of copolymer absorbent of starch-acrylic acid-acrylamide.The effect of different chain transfer agents on the water absorbency was studied.The results indicated that the water absorbency of the product could be improved in the presence of the chain transfer agents.The results concluded that under the otherwise identical conditions when the dosages of isopropanol,formic acid,sodium bisulfite and ascorbic acid were 0.0375%、0.045%、0.075% and 0.01%,the water absorption percentage could reach 498.1,347.9,549.0 and 407.7 g/g respectively.Additionally,the water absorption percentage from the compound chain transfer agents prevailed over the single one.The optimal compound chain transfer agent was the mixture of isopropanol and sodium bisulfite.When the mass ratio of isopropanol and sodium bisulfite was 1∶2 and the dosage of the compound chain transfer agent was 0.08%,the water absorption percentage could reach 653.5 g/g.%分别以抗坏血酸、甲酸、亚硫酸氢钠、异丙醇为链转移剂,研究了不同的链转移剂对淀粉―丙烯酸―丙烯酰胺(ST-AA-AM)吸水剂吸水性能的影响。实验结果表明:异丙醇、甲酸、亚硫酸氢钠、抗坏血酸用量分别为单体总质量的0.0375%、0.045%、0.075%、0.01%时,吸水率分别为498.1 g/g、347.9 g/g、549.0 g/g、407.7 g/g。将链转移剂进行复配,亚硫酸氢钠与异丙醇复配的效果最佳,当复合链转移剂用量占单体总质量的0.08%,异丙醇/亚硫酸氢钠(质量比)=1∶2时,吸水剂的吸水率最高,为653.5 g/g。

  12. Anaerobic biodegradation of oleic and palmitic acids: evidence of mass transfer limitations caused by long chain fatty acid accumulation onto the anaerobic sludge.

    Science.gov (United States)

    Pereira, M A; Pires, O C; Mota, M; Alves, M M

    2005-10-05

    Palmitic acid was the main long chain fatty acids (LCFA) that accumulated onto the anaerobic sludge when oleic acid was fed to an EGSB reactor. The conversion between oleic and palmitic acid was linked to the biological activity. When palmitic acid was fed to an EGSB reactor it represented also the main LCFA that accumulated onto the sludge. The way of palmitic acid accumulation was different in the oleic and in the palmitic acid fed reactors. When oleic acid was fed, the biomass-associated LCFA (83% as palmitic acid) were mainly adsorbed and entrapped in the sludge that became "encapsulated" by an LCFA layer. However, when palmitic acid was fed, the biomass-associated LCFA (the totality as palmitic acid) was mainly precipitated in white spots like precipitates in between the sludge, which remained "non-encapsulated." The two sludges were compared in terms of the specific methanogenic activity (SMA) in the presence of acetate, propionate, butyrate, and H(2)CO(2), before and after the mineralization of similar amounts of biomass-associated LCFA (4.6 and 5.2 g COD-LCFA/g of volatile suspended solids (VSS), for the oleic and palmitic acid fed sludge, respectively). The "non-encapsulated," sludge exhibited a considerable initial methanogenic activity on all the tested substrates, with the single exception of butyrate. However, with the "encapsulated" sludge only methane production from ethanol and H(2)/CO(2) was detected, after a lag phase of about 50 h. After mineralization of the biomass-associated LCFA, both sludges exhibited activities of similar order of magnitude in the presence of the same individual substrates and significantly higher than before. The results evidenced that LCFA accumulation onto the sludge can create a physical barrier and hinder the transfer of substrates and products, inducing a delay on the initial methane production. Whatever the mechanism, metabolic or physical, that is behind this inhibition, it is reversible, being eliminated after the

  13. Amphiphilic block copolymers bearing six-membered ortho ester ring in side chains as potential drug carriers: synthesis, characterization, and in vivo toxicity evaluation.

    Science.gov (United States)

    Luo, Shi; Tao, Yangyang; Tang, Rupei; Wang, Rui; Ji, Weihang; Wang, Chun; Zhao, Youliang

    2014-07-01

    A new type of amphiphilic block copolymers, poly(ethylene glycol)-block-poly(2-methyl-acrylicacid 2-methoxy-5-methyl-[1,3]dioxin-5-ylmethyl ester) (PEG-b-PMME), bearing acid-labile six-membered ortho ester rings in side chains was synthesized by reversible addition-fragmentation chain-transfer polymerization, and the influence of chain length of the hydrophobic PMME block on micelle properties was investigated. The PEG-b-PMME micelles were stable in aqueous buffer at physiological pH with a low critical micelle concentration. Nile Red as a model drug was encapsulated into the micelles to explore the release profiles. The Nile Red-loaded polymeric micelles showed rapid release of Nile Red in weakly acidic environments (pH 5) but slow release under physiological condition (pH 7.4), due to different hydrolysis rate of ortho ester side chains of PEG-b-PMME. The Paclitaxel (PTX)-loaded micelles retained potency in killing lung cancer cells (A549), compared with the free PTX. No obvious toxicity was found in vitro and in vivo after intraperitoneal injection of the micelles, which confirms that the PEG-b-PMME micelles with unique acid-labile characteristic have great potential as nano-scaled carriers for drug delivery.

  14. 关系强度、知识整合能力与供应链知识效率转移研究%The impact of relationship strength and knowledge integration capability on supply chain knowledge transfer

    Institute of Scientific and Technical Information of China (English)

    潘文安

    2012-01-01

    建立紧密的伙伴关系通常被认为是提升供应链知识转移效率的重要手段,但因多数研究者忽视了供应链知识的特性和个体知识整合能力的差异,导致研究结论与实际有很大的不同。本文在理论分析的基础上,采用问卷调查的方式探讨关系强度、知识整合能力与供应链知识转移之间的关系。研究结果显示:关系强度只对供应链协同性知识转移和外部整合能力存在着明显的正向影响,而对创新性知识和内部整合能力则不存在这种影响,透过知识外部整合能力,关系强度对供应链协同性转移的间接影响高于其直接影响,加强知识整合能力建设是企业利用伙伴关系提升供应链协同性知识转移效率的关键。%Establishing a close partnership is considered as an important way to improve the efficiency of supply chain knowledge transfer. However, due to the neglect of both the structural characteristics of supply chain knowledge and the differences between individual knowledge integration capacities by most researchers, the significant difference is observed between the research results and the practice. Based on the theoretical analysis, the relationship among relationship strength, knowledge integration capability, and supply chain knowledge transfer in the form of questionnaires is explored. The results show that relationship strength only has a significant positive impact on cooperative knowledge transfer of supply chain and external integration capability; nevertheless, it is unable to exert an influence on innovative knowledge and internal integration capability. Furthermore, through the external integration capability of the knowledge, the indirect influence on cooperative knowledge transfer of supply chain caused by relationship strength is much greater than the direct influence on that. Therefore, the strengthening knowledge integration capacity is essential in order to improve the

  15. Understanding Transferable Supply Chain Lessons and Practices to a “High-Tech” Industry Using Guidelines from a Primary Sector Industry: A Case Study in the Food Industry Supply Chain

    Directory of Open Access Journals (Sweden)

    Adrian E. Coronado Mondragon

    2015-01-01

    Full Text Available Flexibility and innovation at creating shapes, adapting processes, and modifying materials characterize composites materials, a “high-tech” industry. However, the absence of standard manufacturing processes and the selection of materials with defined properties hinder the configuration of the composites materials supply chain. An interesting alternative for a “high-tech” industry such as composite materials would be to review supply chain lessons and practices in “low-tech” industries such as food. The main motivation of this study is to identify lessons and practices that comprise innovations in the supply chain of a firm in a perceived “low-tech” industry that can be used to provide guidelines in the design of the supply chain of a “high-tech” industry, in this case composite materials. This work uses the case study/site visit with analogy methodology to collect data from a Spanish leading producer of fresh fruit juice which is sold in major European markets and makes use of a cold chain. The study highlights supply base management and visibility/traceability as two elements of the supply chain in a “low-tech” industry that can provide guidelines that can be used in the configuration of the supply chain of the composite materials industry.

  16. Understanding transferable supply chain lessons and practices to a "high-tech" industry using guidelines from a primary sector industry: a case study in the food industry supply chain.

    Science.gov (United States)

    Coronado Mondragon, Adrian E; Coronado Mondragon, Christian E; Coronado, Etienne S

    2015-01-01

    Flexibility and innovation at creating shapes, adapting processes, and modifying materials characterize composites materials, a "high-tech" industry. However, the absence of standard manufacturing processes and the selection of materials with defined properties hinder the configuration of the composites materials supply chain. An interesting alternative for a "high-tech" industry such as composite materials would be to review supply chain lessons and practices in "low-tech" industries such as food. The main motivation of this study is to identify lessons and practices that comprise innovations in the supply chain of a firm in a perceived "low-tech" industry that can be used to provide guidelines in the design of the supply chain of a "high-tech" industry, in this case composite materials. This work uses the case study/site visit with analogy methodology to collect data from a Spanish leading producer of fresh fruit juice which is sold in major European markets and makes use of a cold chain. The study highlights supply base management and visibility/traceability as two elements of the supply chain in a "low-tech" industry that can provide guidelines that can be used in the configuration of the supply chain of the composite materials industry.

  17. Surface functionalization of quantum dots with fine-structured pH-sensitive phospholipid polymer chains.

    Science.gov (United States)

    Liu, Yihua; Inoue, Yuuki; Ishihara, Kazuhiko

    2015-11-01

    To add novel functionality to quantum dots (QDs), we synthesized water-soluble and pH-responsive block-type polymers by reversible addition-fragmentation chain transfer (RAFT) polymerization. The polymers were composed of cytocompatible 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer segments, which contain a small fraction of active ester groups and can be used to conjugate biologically active compounds to the polymer, and pH-responsive poly(2-(N,N-diethylamino) ethyl methacrylate (DEAEMA)) segments. One terminal of the polymer chain had a hydrophobic alkyl group that originated from the RAFT initiator. This hydrophobic group can bind to the hydrophobic layer on the QD surface. A fluorescent dye was conjugated to the polymer chains via the active ester group. The block-type polymers have an amphiphilic nature in aqueous medium. The polymers were thus easily bound to the QD surface upon evaporation of the solvent from a solution containing the block-type polymer and QDs, yielding QD/fluorescence dye-conjugated polymer hybrid nanoparticles. Fluorescence resonance energy transfer (FRET) between the QDs (donors) and the fluorescent dye molecules (acceptors) was used to obtain information on the conformational dynamics of the immobilized polymers. Higher FRET efficiency of the QD/fluorescent dye-conjugated polymer hybrid nanoparticles was observed at pH 7.4 as compared to pH 5.0 due to a stretching-shrinking conformational motion of the poly(DEAEMA) segments in response to changes in pH. We concluded that the block-type MPC polymer-modified nanoparticles could be used to evaluate the pH of cells via FRET fluorescence based on the cytocompatibility of the MPC polymer.

  18. Application of Silent Chain Drive in the Gearbox and Transfer Case for Automobile%齿形链传动在汽车变速箱及分动箱中的应用

    Institute of Scientific and Technical Information of China (English)

    叶斌; 王洪军; 王丹

    2012-01-01

    新型的不同结构形式、不同啮合机制的齿形链产品已经逐渐进入汽车变速箱和分动箱领域.在论述齿形链传动重要技术特性的基础上,着重介绍了其在汽车变速箱、分动箱上的应用优势,分析了混合动力汽车的发展现状及四轮驱动汽车的良好市场前景,对链条行业的产业结构调整具有重要的参考价值.%New silent chains with diverse structures and diverse meshing mechanisms are used in gearbox and transfer case for automobile gradually. On the basis of discussing the important technical characteristics of silent chain, the application advantages of silent chain drive in automotive gearbox and transfer case are emphatically introduced and the development status of the hybrid car and good market prospect of four - wheel drive automobile are analyzed. It has an important reference value for the chain industrial restructuring.

  19. Polyisobutylene chain end transformations: Block copolymer synthesis and click chemistry functionalizations

    Science.gov (United States)

    Magenau, Andrew Jackson David

    The primary objectives of this research were twofold: (1) development of synthetic procedures for combining quasiliving carbocationic polymerization (QLCCP) of isobutylene (IB) and reversible addition fragmentation chain transfer (RAFT) polymerization for block copolymer synthesis; (2) utilization of efficient, robust, and modular chemistries for facile functionalization of polyisobutylene (PIB). In the first study block copolymers consisting of PIB, and either PMMA or PS block segments, were synthesized by a site transformation approach combining living cationic and reversible addition-fragmentation chain transfer (RAFT) polymerizations. The initial PIB block was synthesized via quasiliving cationic polymerization using the TMPCl/TiCl4 initiation system and was subsequently converted into a hydroxylterminated PIB. Site transformation of the hydroxyl-terminated PIB into a macro chain transfer agent (PIB-CTA) was accomplished by N,N'-dicyclohexylcarbodiimide/dimethylaminopyridine-catalyzed esterification with 4-cyano-4-(dodecylsulfanylthiocarbonylsulfanyl)pentanoic acid. In the second study another site transformation approach was developed to synthesize a novel block copolymer, composed of PIB and PNIPAM segments. The PIB block was prepared via quasiliving cationic polymerization and end functionalized by in-situ quenching to yield telechelic halogen-terminated PIB. Azido functionality was obtained by displacement of the terminal halogen through nucleophilic substitution, which was confirmed by both 1H and 13C NMR. Coupling of an alkyne-functional chain transfer agent (CTA) to azido PIB was successfully accomplished through a copper catalyzed click reaction. Structure of the resulting PIB-based macro-CTA was verified with 1H NMR, FTIR, and GPC; whereas coupling reaction kinetics were monitored by real time variable temperature (VT) 1H NMR. In a third study, a click chemistry functionalization procedure was developed based upon the azide-alkyne 1,3-dipolar

  20. Preparation of Transparent Bulk TiO2/PMMA Hybrids with Improved Refractive Indices via an in Situ Polymerization Process Using TiO2 Nanoparticles Bearing PMMA Chains Grown by Surface-Initiated Atom Transfer Radical Polymerization.

    Science.gov (United States)

    Maeda, Satoshi; Fujita, Masato; Idota, Naokazu; Matsukawa, Kimihiro; Sugahara, Yoshiyuki

    2016-12-21

    Transparent TiO2/PMMA hybrids with a thickness of 5 mm and improved refractive indices were prepared by in situ polymerization of methyl methacrylate (MMA) in the presence of TiO2 nanoparticles bearing poly(methyl methacrylate) (PMMA) chains grown using surface-initiated atom transfer radical polymerization (SI-ATRP), and the effect of the chain length of modified PMMA on the dispersibility of modified TiO2 nanoparticles in the bulk hybrids was investigated. The surfaces of TiO2 nanoparticles were modified with both m-(chloromethyl)phenylmethanoyloxymethylphosphonic acid bearing a terminal ATRP initiator and isodecyl phosphate with a high affinity for common organic solvents, leading to sufficient dispersibility of the surface-modified particles in toluene. Subsequently, SI-ATRP of MMA was achieved from the modified surfaces of the TiO2 nanoparticles without aggregation of the nanoparticles in toluene. The molecular weights of the PMMA chains cleaved from the modified TiO2 nanoparticles increased with increases in the prolonging of the polymerization period, and these exhibited a narrow distribution, indicating chain growth controlled by SI-ATRP. The nanoparticles bearing PMMA chains were well-dispersed in MMA regardless of the polymerization period. Bulk PMMA hybrids containing modified TiO2 nanoparticles with a thickness of 5 mm were prepared by in situ polymerization of the MMA dispersion. The transparency of the hybrids depended significantly on the chain length of the modified PMMA on the nanoparticles, because the modified PMMA of low molecular weight induced aggregation of the TiO2 nanoparticles during the in situ polymerization process. The refractive indices of the bulk hybrids could be controlled by adjusting the TiO2 content and could be increased up to 1.566 for 6.3 vol % TiO2 content (1.492 for pristine PMMA).

  1. Transfer of noncovalent chiral information along an optically inactive helical peptide chain: allosteric control of asymmetry of the C-terminal site by external molecule that binds to the N-terminal site.

    Science.gov (United States)

    Ousaka, Naoki; Inai, Yoshihito

    2009-02-20

    This study aims at demonstrating end-to-end transfer of noncovalent chiral information along a peptide chain. The domino-type induction of helical sense is proven by using achiral peptides 1-m of bis-chromophoric sequence with different chain lengths: H-(Aib-Delta(Z)Phe)(m)-(Aib-Delta(Z)Bip)(2)-Aib-OCH(3) [m = 2, 4, and 6; Aib = alpha-aminoisobutyric acid; Delta(Z)Phe = (Z)-alpha,beta-didehydrophenylalanine; Delta(Z)Bip = (Z)-beta-(4,4'-biphenyl)-alpha,beta-didehydroalanine]. They all showed the tendency to adopt a 3(10)-helix. Whereas peptide 1-m originally shows no circular dichroism (CD) signals, marked CD signals were induced at around 270-320 nm based on both the beta-aryl didehydroresidues by chiral Boc-proline (Boc = tert-butoxycarbonyl). The observed CD spectra were interpreted on the basis of the exciton chirality method and theoretical CD simulation of several helical conformations that were energy-minimized. The experimental and theoretical CD analysis reveals that Boc-l-proline induces the preference for a right-handed helicity in the whole chain of 1-m. Such noncovalent chiral induction was not observed in the corresponding N-terminally protected 1-m. Obviously, helicity induction in 1-m originates from the binding of Boc-proline to the N-terminal site. In the 17-mer (1-6), the information of helix sense reaches the 16th residue from the N-terminus. We have monitored precise transfer of noncovalent chiral stimulus along a helical peptide chain. The present study also proposes a primitive allosteric model of a single protein-mimicking backbone. Here chiral molecule binding the N-terminal site of 1-6 controls the chiroptical signals and helical sense of the C-terminal site about 30 A away.

  2. Bcl-1 gene rearrangements in mantle cell lymphoma : A comprehensive analysis of 118 cases, including B-5-fixed tissue, by polymerase chain reaction and southern transfer analysis

    NARCIS (Netherlands)

    Chibbar, R; Leung, K; McCormick, S; Ritzkalla, K; Strickler, J; Staggs, R; Poppema, S; Brunning, RD; McGlennen, RC

    1998-01-01

    We evaluated 118 cases of mantle cell lymphoma by polymerase chain reaction (PCR) for the major translocation cluster (MIG) region and another breakpoint corresponding to probe p94(PS), located 24 kb telomeric to the MTC locus on chromosome 11. The specimens included 64 frozen, 19 formalin-fixed, an

  3. Electron Transfer of Myoglobin Immobilized in Au Electrodes Modified with a RAFT PMMA-Block-PDMAEMA Polymer

    Directory of Open Access Journals (Sweden)

    Carla N. Toledo

    2014-01-01

    Full Text Available Myoglobin was immobilized with poly(methyl methacrylate-block-poly[(2-dimethylaminoethyl methacrylate]PMMA-block-PDMAEMA polymer synthesized by reversible addition-fragmentation chain transfer technique (RAFT. Cyclic voltammograms gave direct and slow quasireversible heterogeneous electron transfer kinetics between Mb-PMMA-block-PDMAEMA modified electrode and the redox center of the protein. The values for electron rate constant (Ks and transfer coefficient (α were 0.055±0.01·s−1 and 0.81±0.08, respectively. The reduction potential determined as a function of temperature (293–328 K revealed a value of reaction center entropy of ΔS0 of 351.3±0.0002 J·mol−1·K−1 and enthalpy change of -76.8±0.1 kJ·mol−1, suggesting solvent effects and charge ionization atmosphere involved in the reaction parallel to hydrophobic interactions with the copolymer. The immobilized protein also exhibits an electrocatalytical response to reduction of hydrogen peroxide, with an apparent Km of 114.7±58.7 μM. The overall results substantiate the design and use of RAFT polymers towards the development of third-generation biosensors.

  4. pH-induced vesicle-to-micelle transition in amphiphilic diblock copolymer: investigation by energy transfer between in situ formed polymer embedded gold nanoparticles and fluorescent dye.

    Science.gov (United States)

    Maiti, Chiranjit; Banerjee, Rakesh; Maiti, Saikat; Dhara, Dibakar

    2015-01-01

    The ability to regulate the formation of nanostructures through self-assembly of amphiphilic block copolymers is of immense significance in the field of biology and medicine. In this work, a new block copolymer synthesized by using reversible addition-fragmentation chain transfer (RAFT) polymerization technique from poly(ethylene glycol) monomethyl ether acrylate (PEGMA) and Boc-l-tryptophan acryloyloxyethyl ester (Boc-l-trp-HEA) was found to spontaneously form pH-responsive water-soluble nanostructures after removal of the Boc group. While polymer vesicles or polymerosomes were formed at physiological pH, the micelles were formed at acidic pH (transition. Formation of these nanostructures was confirmed by different characterization techniques, viz. transmission electron microscopy, dynamic light scattering, and steady-state fluorescence measurements. Further, these vesicles were successfully utilized to reduce HAuCl4 and stabilize the resulting gold nanoparticles (AuNPs). These AuNPs, confined within the hydrophobic shell of the vesicles, could participate in energy transfer process with fluorescent dye molecules encapsulated in the core of the vesicles, thus forming a nanometal surface energy transfer (NSET) pair. Subsequently, following the efficiency of energy transfer between this pair, it was possible to monitor the process of transition from vesicles to micelles. Thus, in this work, we have successfully demonstrated that NSET can be used to follow the transition between nanostructures formed by amphiphilic block copolymers.

  5. Effects of medium-chain fatty acids and oleic acid on blood lipids, lipoproteins, glucose, insulin, and lipid transfer protein activities

    DEFF Research Database (Denmark)

    Tholstrup, T.; Ehnholm, C.; Jauhiainen, M.;

    2004-01-01

    design, 17 healthy young men replaced part of their habitual dietary fat intake with 70 g MCTs (66% 8:0 and 34% 10:0) or high-oleic sunflower oil (89.4% 18:1). Each intervention period lasted 21 d, and the 2 periods were separated by a washout period of 2 wk. Blood samples were taken before and after...... the intervention periods. Results: Compared with the intake of high-oleic sunflower oil, MCT intake resulted in 11% higher plasma total cholesterol (P = 0.0005), 12% higher LDL cholesterol (P = 0.0001), 32% higher VLDL cholesterol (P = 0.080), a 12% higher ratio of LDL to HDL cholesterol (P = 0.002), 22% higher......Background: Dietary medium-chain fatty acids (MCFAs) are of nutritional interest because they are more easily absorbed from dietary medium-chain triacylglycerols (MCTs) than are long-chain fatty acids from, for example, vegetable oils. It has generally been claimed that MCFAs do not increase plasma...

  6. Study of the Chain Transfer Reaction of 3-Mercaptohexanol in the Styrene Polymerization%3-巯基己醇在苯乙烯聚合体系中的链转移反应行为

    Institute of Scientific and Technical Information of China (English)

    张薇; 黄文艳; 李少杰; 薛小强; 蒋必彪

    2011-01-01

    The polymerization of styrene was carried out in the presence of 3 - mercaptohexanol at different temperature with AIBN as the initiator and toluene as the internal standard. The chain transfer constant of 3 - mercaptohexanol under the experimental condition was obtained by the Mayo equation. It is 3. 99, 3. 58 and 2. 24 at the polymerization temperature of 60 ℃ , 70 ℃ and 80 ℃ respectively. As the temperature increased, the chain transfer constant of 3 - mercaptohexanol decreased. Further research showed that; under the polymerization condition, the products with very low molecular weight were formed from the 3-mercaptohexanol transferring to styrene radical. The dimer and trimer of these products were obtained by high performance liquid chromatography and confirmed by proton nuclear magnetic resonance (1H NMR) and liquid chromatography-mass spectrometry (LC - MS). The productivity of these products increased significantly as the reaction temperature increased. Therefore, the obtained chain transfer constant is only the apparent value because of the formation of the molecules with very low molecular weight.%以偶氯二异丁腈(AIBN)为引发剂,甲苯为内标,3-巯基己醇为链转移剂进行苯乙烯(St)聚合.根据Mayo等式,求出了60℃,70℃和80℃下的链转移常数,分别为3.99,3.58和2.24,表明链转移常数随着温度的升高而减小.采用制备色谱分离得到了聚合初期的产物,并且由核磁共振(1H NMR)和液-质联用(LC-MS)确证了生成的小分子产物的结构.定量分析结果表明:在相同的巯基醇转化率下,相对分子质量低的产物的生成量随反应温度的升高而显著增加,以聚合物相对分子质量为基础计算得到的表观链转移常数则变小.

  7. A polymorphic variant in the human electron transfer flavoprotein alpha-chain (alpha-T171) displays decreased thermal stability and is overrepresented in very-long-chain acyl-CoA dehydrogenase-deficient patients with mild childhood presentation

    DEFF Research Database (Denmark)

    Bross, P; Pedersen, P; Nyholm, M;

    1999-01-01

    The consequences of two amino acid polymorphisms of human electron transfer flavoprotein (alpha-T/I171 in the alpha-subunit and beta-M/T154 in the beta-subunit) on the thermal stability of the enzyme are described. The alpha-T171 variant displayed a significantly decreased thermal stability...... thermal stability) was significantly overrepresented. Subgrouping of the VLCAD patients into three phenotypic classes (severe childhood, mild childhood, and adult presentation) revealed that the overrepresentation of the alpha-T171 variant was significant only in patients with mild childhood presentation...

  8. Calibration of environmental radionuclide transfer models using a Bayesian approach with Markov chain Monte Carlo simulations and model comparisons - Calibration of radionuclides transfer models in the environment using a Bayesian approach with Markov chain Monte Carlo simulation and comparison of models

    Energy Technology Data Exchange (ETDEWEB)

    Nicoulaud-Gouin, V.; Giacalone, M.; Gonze, M.A. [Institut de Radioprotection et de Surete Nucleaire-PRP-ENV/SERIS/LM2E (France); Martin-Garin, A.; Garcia-Sanchez, L. [IRSN-PRP-ENV/SERIS/L2BT (France)

    2014-07-01

    Calibration of transfer models according to observation data is a challenge, especially if parameters uncertainty is required, and if competing models should be decided between them. Generally two main calibration methods are used: The frequentist approach in which the unknown parameter of interest is supposed fixed and its estimation is based on the data only. In this category, least squared method has many restrictions in nonlinear models and competing models need to be nested in order to be compared. The bayesian inference in which the unknown parameter of interest is supposed random and its estimation is based on the data and on prior information. Compared to frequentist method, it provides probability density functions and therefore pointwise estimation with credible intervals. However, in practical cases, Bayesian inference is a complex problem of numerical integration, which explains its low use in operational modeling including radioecology. This study aims to illustrate the interest and feasibility of Bayesian approach in radioecology particularly in the case of ordinary differential equations with non-constant coefficients models, which cover most radiological risk assessment models, notably those implemented in the Symbiose platform (Gonze et al, 2010). Markov Chain Monte Carlo (MCMC) method (Metropolis et al., 1953) was used because the posterior expectations are intractable integrals. The invariant distribution of the parameters was performed by the metropolis-Hasting algorithm (Hastings, 1970). GNU-MCSim software (Bois and Maszle, 2011) a bayesian hierarchical framework, was used to deal with nonlinear differential models. Two case studies including this type of model were investigated: An Equilibrium Kinetic sorption model (EK) (e.g. van Genuchten et al, 1974), with experimental data concerning {sup 137}Cs and {sup 85}Sr sorption and desorption in different soils studied in stirred flow-through reactors. This model, generalizing the K{sub d} approach

  9. Enhanced binding capacity of boronate affinity adsorbent via surface modification of silica by combination of atom transfer radical polymerization and chain-end functionalization for high-efficiency enrichment of cis-diol molecules.

    Science.gov (United States)

    Wang, Wei; He, Maofang; Wang, Chaozhan; Wei, Yinmao

    2015-07-30

    Boronate affinity materials have been widely used for specific separation and preconcentration of cis-diol molecules, but most do not have sufficient capacity due to limited binding sites on the material surface. In this work, we prepared a phenylboronic acid-functionalized adsorbent with a high binding capacity via the combination of surface-initiated atom transfer radical polymerization (SI-ATRP) and chain-end functionalization. With this method, the terminal chlorides of the polymer chains were used fully, and the proposed adsorbent contains dense boronic acid polymers chain with boronic acid on the chain end. Consequently, the proposed adsorbent possesses excellent selectivity and a high binding capacity of 513.6 μmol g(-1) for catechol and 736.8 μmol g(-1) for fructose, which are much higher than those of other reported adsorbents. The dispersed solid-phase extraction (dSPE) based on the prepared adsorbent was used for extraction of three cis-diol drugs (i.e., epinephrine, isoprenaline and caffeic acid isopropyl ester) from plasma; the eluates were analyzed by HPLC-UV. The reduced amount of adsorbent (i.e., 2.0 mg) could still eliminate interferences efficiently and yielded a recovery range of 85.6-101.1% with relative standard deviations ranging from 2.5 to 9.7% (n = 5). The results indicated that the proposed strategy could serve as a promising alternative to increase the density of surface functional groups on the adsorbent; thus, the prepared adsorbent has the potential to effectively enrich cis-diol substances in real samples.

  10. Enhanced binding capacity of boronate affinity adsorbent via surface modification of silica by combination of atom transfer radical polymerization and chain-end functionalization for high-efficiency enrichment of cis-diol molecules

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; He, Maofang; Wang, Chaozhan; Wei, Yinmao, E-mail: ymwei@nwu.edu.cn

    2015-07-30

    Boronate affinity materials have been widely used for specific separation and preconcentration of cis-diol molecules, but most do not have sufficient capacity due to limited binding sites on the material surface. In this work, we prepared a phenylboronic acid-functionalized adsorbent with a high binding capacity via the combination of surface-initiated atom transfer radical polymerization (SI-ATRP) and chain-end functionalization. With this method, the terminal chlorides of the polymer chains were used fully, and the proposed adsorbent contains dense boronic acid polymers chain with boronic acid on the chain end. Consequently, the proposed adsorbent possesses excellent selectivity and a high binding capacity of 513.6 μmol g{sup −1} for catechol and 736.8 μmol g{sup −1} for fructose, which are much higher than those of other reported adsorbents. The dispersed solid-phase extraction (dSPE) based on the prepared adsorbent was used for extraction of three cis-diol drugs (i.e., epinephrine, isoprenaline and caffeic acid isopropyl ester) from plasma; the eluates were analyzed by HPLC-UV. The reduced amount of adsorbent (i.e., 2.0 mg) could still eliminate interferences efficiently and yielded a recovery range of 85.6–101.1% with relative standard deviations ranging from 2.5 to 9.7% (n = 5). The results indicated that the proposed strategy could serve as a promising alternative to increase the density of surface functional groups on the adsorbent; thus, the prepared adsorbent has the potential to effectively enrich cis-diol substances in real samples. - Highlights: • Boronate adsorbent is prepared via ATRP and chain-end functionalization. • The adsorbent has quite high binding capacity for cis-diols. • Binding capacity is easily manipulated by ATRP condition. • Chain-end functionalization can improve binding capacity significantly. • Reduced adsorbent is consumed in dispersed solid-phase extraction of cis-diols.

  11. Comparison of transfer and effects of Cd on rats exposed in a short experimental snail-rat food chain or to CdCl2 dosed food.

    Science.gov (United States)

    Hispard, F; de Vaufleury, A; Cosson, R P; Devaux, S; Scheifler, R; Coeurdassier, M; Gimbert, F; Martin, H; Richert, L; Berthelot, A; Badot, P-M

    2008-04-01

    Transfer and toxic effects of two cadmium (Cd) forms, inorganic (CdCl2 dosed rat food) or organic (contaminated snail-based rat food) were studied in Wistar rat. Cd concentrations in rat food were 0 and 2.5 microg Cd g(-1) for both inorganic and organic forms and a high concentration of 100 microg Cd g(-1) was also tested for the inorganic form. Rats were exposed for four weeks to contaminated food. Both forms of Cd were bioavailable to rats, with a percentage of transfer from food to rats of around 1% for all contaminated groups. Cd concentrations in rat tissues increased with increasing Cd concentrations in the food. Rats fed with organic form of Cd accumulated significantly more Cd in the main organ for Cd toxicity, the kidney, than those eating the inorganic form. Survival was not affected for any rat group but a decrease in growth and food consumption was observed for the inorganic form. As a defence system against Cd toxicity, rats increased their metallothionein (MT) synthesis at the highest Cd concentration in the target organs (kidney, liver and small intestine) and even did the same at low Cd concentrations (2.5 microg Cd g(-1)) in the kidney. At this low Cd concentration, MT induction was lower in the small intestine of rats ingesting organic Cd than those ingesting inorganic Cd. Bioavailability of organic and inorganic forms of Cd was similar, but subsequent Cd distribution within organs was different. This quantification of the trophic transfer of both inorganic and organic forms of a toxicant is a basis for a better assessment of the fate and effects of chemicals in food webs.

  12. Synthesis of Novel μ-Star Copolymers with Poly(N-Octyl Benzamide) and Poly(ε-Caprolactone) Miktoarms through Chain-Growth Condensation Polymerization, Styrenics-Assisted Atom Transfer Radical Coupling, and Ring-Opening Polymerization.

    Science.gov (United States)

    Huang, Chih-Feng; Aimi, Junko; Lai, Kuan-Yu

    2017-02-01

    Star copolymers are known to phase separate on the nanoscale, providing useful self-assembled morphologies. In this study, the authors investigate synthesis and assembly behavior of miktoarm star (μ-star) copolymers. The authors employ a new strategy for the synthesis of unprecedented μ-star copolymers presenting poly(N-octyl benzamide) (PBA) and poly(ε-caprolactone) (PCL) arms: a combination of chain-growth condensation polymerization, styrenics-assisted atom transfer radical coupling, and ring-opening polymerization. Gel permeation chromatography, mass-analyzed laser desorption/ionization mass spectrometry, and (1) H NMR spectroscopy reveal the successful synthesis of a well-defined (PBA11 )2 -(PCL15 )4 μ-star copolymer (Mn,NMR ≈ 12 620; Đ = 1.22). Preliminary examination of the PBA2 PCL4 μ-star copolymer reveals assembled nanofibers having a uniform diameter of ≈20 nm.

  13. Transfer of heavy metals in the food chain earthworm Black-tailed godwit (Limosa limosa): Comparison of a polluted and a reference site in The Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Roodbergen, Maja [Department of Ecology and Environment, ALTERRA, PO Box 47, 6700 AA, Wageningen (Netherlands); Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Haren (Netherlands)], E-mail: maja.roodbergen@sovon.nl; Klok, Chris; Hout, Annemariet van der [Department of Ecology and Environment, ALTERRA, PO Box 47, 6700 AA, Wageningen (Netherlands)

    2008-12-01

    The Black-tailed godwit (Limosa limosa) is a migratory wader that favours wet meadows for breeding. The species has a Red List status in The Netherlands, as it strongly declined in numbers since the 1960s. Intensification of agriculture and land use change resulting in habitat loss are considered major causes of this decline. In some areas the breeding habitat is contaminated with heavy metals. Adult godwits mainly feed on earthworms in the breeding season, which are known to accumulate heavy metals from the soil. In this paper we investigate the transfer of heavy metals from the soil to the Black-tailed godwit, which may have an additive negative effect on the viability of local populations. We measured heavy metal concentrations in soil, earthworms, and godwit eggs and feathers at a polluted and a reference site. The results suggest that Lead, Mercury and Cadmium are transferred from the soil to godwits even though the species spends only a few months in the breeding area during the year.

  14. Unwrapping Chains

    CERN Document Server

    Cambou, A D; Hamm, E; Hanna, J A; Menon, N; Santangelo, C D; Walsh, L

    2012-01-01

    A loop of chain can move along its own tangents, maintaining a steady shape. An open-ended chain undergoing a nontrivial motion must change its shape. One consequence is that chains pulled around objects will fail to follow the contours of the objects, unwrapping themselves instead. This short note accompanies a fluid dynamics video submission (83068) to the APS DFD Gallery of Fluid Motion 2012.

  15. Resonance Energy Transfer-Based Molecular Switch Designed Using a Systematic Design Process Based on Monte Carlo Methods and Markov Chains

    Science.gov (United States)

    Rallapalli, Arjun

    A RET network consists of a network of photo-active molecules called chromophores that can participate in inter-molecular energy transfer called resonance energy transfer (RET). RET networks are used in a variety of applications including cryptographic devices, storage systems, light harvesting complexes, biological sensors, and molecular rulers. In this dissertation, we focus on creating a RET device called closed-diffusive exciton valve (C-DEV) in which the input to output transfer function is controlled by an external energy source, similar to a semiconductor transistor like the MOSFET. Due to their biocompatibility, molecular devices like the C-DEVs can be used to introduce computing power in biological, organic, and aqueous environments such as living cells. Furthermore, the underlying physics in RET devices are stochastic in nature, making them suitable for stochastic computing in which true random distribution generation is critical. In order to determine a valid configuration of chromophores for the C-DEV, we developed a systematic process based on user-guided design space pruning techniques and built-in simulation tools. We show that our C-DEV is 15x better than C-DEVs designed using ad hoc methods that rely on limited data from prior experiments. We also show ways in which the C-DEV can be improved further and how different varieties of C-DEVs can be combined to form more complex logic circuits. Moreover, the systematic design process can be used to search for valid chromophore network configurations for a variety of RET applications. We also describe a feasibility study for a technique used to control the orientation of chromophores attached to DNA. Being able to control the orientation can expand the design space for RET networks because it provides another parameter to tune their collective behavior. While results showed limited control over orientation, the analysis required the development of a mathematical model that can be used to determine the

  16. IL-4 function can be transferred to the IL-2 receptor by tyrosine containing sequences found in the IL-4 receptor alpha chain.

    Science.gov (United States)

    Wang, H Y; Paul, W E; Keegan, A D

    1996-02-01

    IL-4 binds to a cell surface receptor complex that consists of the IL-4 binding protein (IL-4R alpha) and the gamma chain of the IL-2 receptor complex (gamma c). The receptors for IL-4 and IL-2 have several features in common; both use the gamma c as a receptor component, and both activate the Janus kinases JAK-1 and JAK-3. In spite of these similarities, IL-4 evokes specific responses, including the tyrosine phosphorylation of 4PS/IRS-2 and the induction of CD23. To determine whether sequences within the cytoplasmic domain of the IL-4R alpha specify these IL-4-specific responses, we transplanted the insulin IL-4 receptor motif (I4R motif) of the huIL-4R alpha to the cytoplasmic domain of a truncated IL-2R beta. In addition, we transplanted a region that contains peptide sequences shown to block Stat6 binding to DNA. We analyzed the ability of cells expressing these IL-2R-IL-4R chimeric constructs to respond to IL-2. We found that IL-4 function could be transplanted to the IL-2 receptor by these regions and that proliferative and differentiative functions can be induced by different receptor sequences.

  17. Development and inter-laboratory transfer of a decaplex polymerase chain reaction assay combined with capillary electrophoresis for the simultaneous detection of ten food allergens.

    Science.gov (United States)

    Cheng, Fang; Wu, Jiajie; Zhang, Jin; Pan, Aihu; Quan, Sheng; Zhang, Dabing; Kim, HaeYeong; Li, Xiang; Zhou, Shan; Yang, Litao

    2016-05-15

    Food allergies cause health risks to susceptible consumers and regulations on labeling of food allergen contents have been implemented in many countries and regions. To achieve timely and accurate food allergen labeling, the development of fast and effective allergen detection methods is very important. Herein, a decaplex polymerase chain reaction (PCR) assay combined with capillary electrophoresis was developed to detect simultaneously 10 common food allergens from hazelnut, pistachio, oat, sesame, peanut, cashew, barley, wheat, soybean and pecan. The absolute limit of detection (LODa) of this system is between 2 and 20 copies of haploid genome, and the relative LOD (LODr) is as low as 0.005% (w/w) in simulated food mixtures. The developed assay was subsequently applied to 20 commercial food products and verified the allergen ingredients stated on the labels. Furthermore, results using this decaplex PCR assay was successfully replicated in three other laboratories, demonstrating the repeatability and applicability of this assay in routine analysis of the 10 food allergens.

  18. Detection of subgenomic mRNA of feline coronavirus by real-time polymerase chain reaction based on primer-probe energy transfer (P-sg-QPCR).

    Science.gov (United States)

    Hornyák, Akos; Bálint, Adám; Farsang, Attila; Balka, Gyula; Hakhverdyan, Mikhayil; Rasmussen, Thomas Bruun; Blomberg, Jonas; Belák, Sándor

    2012-05-01

    Feline infectious peritonitis is one of the most severe devastating diseases of the Felidae. Upon the appearance of clinical signs, a cure for the infected animal is impossible. Therefore rapid and proper diagnosis for both the presence of the causative agent, feline coronavirus (FCoV) and the manifestation of feline infectious peritonitis is of paramount importance. In the present work, a novel real-time RT-PCR method is described which is able to detect FCoV and to determine simultaneously the quantity of the viral RNA. The new assay combines the M gene subgenomic messenger RNA (sg-mRNA) detection and the quantitation of the genome copies of FCoV. In order to detect the broadest spectrum of potential FCoV variants and to achieve the most accurate results in the detection ability the new assay is applying the primer-probe energy transfer (PriProET) principle. This technology was chosen since PriProET is very robust to tolerate the nucleotide substitutions in the target area. Therefore, this technology provides a very broad-range system, which is able to detect simultaneously many variants of the virus(es) even if the target genomic regions show large scale of variations. The detection specificity of the new assay was proven by positive amplification from a set of nine different FCoV strains and negative from the tested non-coronaviral targets. Examination of faecal samples of healthy young cats, organ samples of perished animals, which suffered from feline infectious peritonitis, and cat leukocytes from uncertain clinical cases were also subjected to the assay. The sensitivity of the P-sg-QPCR method was high, since as few as 10 genome copies of FCoV were detected. The quantitative sg-mRNA detection method revealed more than 10-50,000 times increase of the M gene sg-mRNA in organ materials of feline infectious peritonitis cases, compared to those of the enteric FCoV variants present in the faeces of normal, healthy cats. These results indicate the applicability of

  19. Dietary avocado oil supplementation attenuates the alterations induced by type I diabetes and oxidative stress in electron transfer at the complex II-complex III segment of the electron transport chain in rat kidney mitochondria.

    Science.gov (United States)

    Ortiz-Avila, Omar; Sámano-García, Carlos Alberto; Calderón-Cortés, Elizabeth; Pérez-Hernández, Ismael H; Mejía-Zepeda, Ricardo; Rodríguez-Orozco, Alain R; Saavedra-Molina, Alfredo; Cortés-Rojo, Christian

    2013-06-01

    Impaired complex III activity and reactive oxygen species (ROS) generation in mitochondria have been identified as key events leading to renal damage during diabetes. Due to its high content of oleic acid and antioxidants, we aimed to test whether avocado oil may attenuate the alterations in electron transfer at complex III induced by diabetes by a mechanism related with increased resistance to lipid peroxidation. 90 days of avocado oil administration prevented the impairment in succinate-cytochrome c oxidoreductase activity caused by streptozotocin-induced diabetes in kidney mitochondria. This was associated with a protection against decreased electron transfer through high potential chain in complex III related to cytochromes c + c1 loss. During Fe(2+)-induced oxidative stress, avocado oil improved the activities of complexes II and III and enhanced the protection conferred by a lipophilic antioxidant against damage by Fe(2+). Avocado oil also decreased ROS generation in Fe(2+)-damaged mitochondria. Alterations in the ratio of C20:4/C18:2 fatty acids were observed in mitochondria from diabetic animals that not were corrected by avocado oil treatment, which yielded lower peroxidizability indexes only in diabetic mitochondria although avocado oil caused an augment in the total content of monounsaturated fatty acids. Moreover, a protective effect of avocado oil against lipid peroxidation was observed consistently only in control mitochondria. Since the beneficial effects of avocado oil in diabetic mitochondria were not related to increased resistance to lipid peroxidation, these effects were discussed in terms of the antioxidant activity of both C18:1 and the carotenoids reported to be contained in avocado oil.

  20. Markov Chains and Markov Processes

    OpenAIRE

    2016-01-01

    Markov chain, which was named after Andrew Markov is a mathematical system that transfers a state to another state. Many real world systems contain uncertainty. This study helps us to understand the basic idea of a Markov chain and how is been useful in our daily lives. For some times there had been suspense on distinct predictions and future existences. Also in different games there had been different expectations or results involved. That is the reason why we need Markov chains to predict o...

  1. Application of a real-time fluorescence resonance energy transfer polymerase chain reaction assay with melting curve analysis for the detection of Paragonimus heterotremus eggs in the feces of experimentally infected cats.

    Science.gov (United States)

    Tantrawatpan, Chairat; Intapan, Pewpan M; Thanchomnang, Tongjit; Sanpool, Oranuch; Janwan, Penchom; Lulitanond, Viraphong; Anamnart, Witthaya; Maleewong, Wanchai

    2013-09-01

    Paragonimus heterotremus is a medically important lung fluke that causes human and animal paragonimiasis in Southeast Asia, including Thailand. In the current study, a real-time fluorescence resonance energy transfer polymerase chain reaction (real-time FRET PCR) with melting curve analysis was developed and evaluated to detect P. heterotremus eggs in the feces of experimentally infected cats. The detection limit of this method for the P. heterotremus DNA sequence was 3 × 10(2) copies of the positive control plasmid and 10(-3) ng of P. heterotremus genomic DNA. The assay system could detect 10 eggs of P. heterotremus per gram of cat feces. No fluorescence signal was observed when DNA purified from 16 other organisms or genomic DNA from cats and human beings were tested. Real-time FRET PCR yielded positive results for all fecal samples from 17 P. heterotremus-infected cats and showed a negative relationship (r = -0.852, P analysis. This assay can be useful for the detection of, and epidemiological studies on, P. heterotremus infection in endemic areas.

  2. Detection of Babesia canis vogeli and Hepatozoon canis in canine blood by a single-tube real-time fluorescence resonance energy transfer polymerase chain reaction assay and melting curve analysis.

    Science.gov (United States)

    Kongklieng, Amornmas; Intapan, Pewpan M; Boonmars, Thidarut; Thanchomnang, Tongjit; Janwan, Penchom; Sanpool, Oranuch; Lulitanond, Viraphong; Taweethavonsawat, Piyanan; Chungpivat, Sudchit; Maleewong, Wanchai

    2015-03-01

    A real-time fluorescence resonance energy transfer polymerase chain reaction (qFRET PCR) coupled with melting curve analysis was developed for detection of Babesia canis vogeli and Hepatozoon canis infections in canine blood samples in a single tube assay. The target of the assay was a region within the 18S ribosomal RNA gene amplified in either species by a single pair of primers. Following amplification from the DNA of infected dog blood, a fluorescence melting curve analysis was done. The 2 species, B. canis vogeli and H. canis, could be detected and differentiated in infected dog blood samples (n = 37) with high sensitivity (100%). The detection limit for B. canis vogeli was 15 copies of a positive control plasmid, and for H. canis, it was 150 copies of a positive control plasmid. The assay could simultaneously distinguish the DNA of both parasites from the DNA of controls. Blood samples from 5 noninfected dogs were negative, indicating high specificity. Several samples can be run at the same time. The assay can reduce misdiagnosis and the time associated with microscopic examination, and is not prone to the carryover contamination associated with the agarose gel electrophoresis step of conventional PCR. In addition, this qFRET PCR method would be useful to accurately determine the range of endemic areas or to discover those areas where the 2 parasites co-circulate.

  3. Chain Gang

    Science.gov (United States)

    2006-01-01

    6 August 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a chain of clustered and battered craters. These were formed by secondary impact. That is, somewhere to the south (beyond the bottom of this image), a large impact crater formed. When this occurred, material ejected from the crater was thrown tens to hundreds of kilometers away. This material then impacted the martian surface, forming clusters and chains of smaller craters. Location near: 15.8oN, 35.6oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Northern Spring

  4. Extended linear chain compounds

    CERN Document Server

    Linear chain substances span a large cross section of contemporary chemistry ranging from covalent polymers, to organic charge transfer com­ plexes to nonstoichiometric transition metal coordination complexes. Their commonality, which coalesced intense interest in the theoretical and exper­ imental solid state physics/chemistry communities, was based on the obser­ vation that these inorganic and organic polymeric substrates exhibit striking metal-like electrical and optical properties. Exploitation and extension of these systems has led to the systematic study of both the chemistry and physics of highly and poorly conducting linear chain substances. To gain a salient understanding of these complex materials rich in anomalous aniso­ tropic electrical, optical, magnetic, and mechanical properties, the conver­ gence of diverse skills and talents was required. The constructive blending of traditionally segregated disciplines such as synthetic and physical organic, inorganic, and polymer chemistry, crystallog...

  5. Bacterial Electron Transfer Chains Primed by Proteomics

    NARCIS (Netherlands)

    Wessels, H.; Almeida, N.M. de; Kartal, B.; Keltjens, J.T.

    2016-01-01

    Electron transport phosphorylation is the central mechanism for most prokaryotic species to harvest energy released in the respiration of their substrates as ATP. Microorganisms have evolved incredible variations on this principle, most of these we perhaps do not know, considering that only a fracti

  6. Large Deviations in Quantum Spin Chain

    CERN Document Server

    Ogata, Yoshiko

    2008-01-01

    We show the full large deviation principle for KMS-states and $C^*$-finitely correlated states on a quantum spin chain. We cover general local observables. Our main tool is Ruelle's transfer operator method.

  7. Vinylimidazole-Based Asymmetric Ion Pair Comonomers: Synthesis, Polymerization Studies and Formation of Ionically Crosslinked PMMA

    NARCIS (Netherlands)

    Jana, S.; Vasantha, V.A.; Stubbs, L.P.; Parthiban, A.; Vancso, G.J.

    2013-01-01

    Vinylimidazole-based asymmetric ion pair comonomers (IPCs) which are free from nonpolymerizable counter ions have been synthesized, characterized and polymerized by free radical polymerization (FRP), atom transfer radical polymerization (ATRP), and reversible addition-fragmentation chain transfer (R

  8. Electron transfer in peptides.

    Science.gov (United States)

    Shah, Afzal; Adhikari, Bimalendu; Martic, Sanela; Munir, Azeema; Shahzad, Suniya; Ahmad, Khurshid; Kraatz, Heinz-Bernhard

    2015-02-21

    In this review, we discuss the factors that influence electron transfer in peptides. We summarize experimental results from solution and surface studies and highlight the ongoing debate on the mechanistic aspects of this fundamental reaction. Here, we provide a balanced approach that remains unbiased and does not favor one mechanistic view over another. Support for a putative hopping mechanism in which an electron transfers in a stepwise manner is contrasted with experimental results that support electron tunneling or even some form of ballistic transfer or a pathway transfer for an electron between donor and acceptor sites. In some cases, experimental evidence suggests that a change in the electron transfer mechanism occurs as a result of donor-acceptor separation. However, this common understanding of the switch between tunneling and hopping as a function of chain length is not sufficient for explaining electron transfer in peptides. Apart from chain length, several other factors such as the extent of the secondary structure, backbone conformation, dipole orientation, the presence of special amino acids, hydrogen bonding, and the dynamic properties of a peptide also influence the rate and mode of electron transfer in peptides. Electron transfer plays a key role in physical, chemical and biological systems, so its control is a fundamental task in bioelectrochemical systems, the design of peptide based sensors and molecular junctions. Therefore, this topic is at the heart of a number of biological and technological processes and thus remains of vital interest.

  9. Graphs: Associated Markov Chains

    OpenAIRE

    2012-01-01

    In this research paper, weighted / unweighted, directed / undirected graphs are associated with interesting Discrete Time Markov Chains (DTMCs) as well as Continuous Time Markov Chains (CTMCs). The equilibrium / transient behaviour of such Markov chains is studied. Also entropy dynamics (Shannon entropy) of certain structured Markov chains is investigated. Finally certain structured graphs and the associated Markov chains are studied.

  10. Backward Charge Transfer in Conjugated Polymers

    Institute of Scientific and Technical Information of China (English)

    CHENG Meng-Xing; LI Guang-Qi; Thomas F. George; SUN Xin

    2005-01-01

    It has been known that the static polarizability of a polymer chain with a biexciton is negative. In order to understand this peculiar fact, this paper studies the dynamical process of the charge transfer in the polymer chain induced by an external electric field E during forming the biexciton. The time dependence of the charge distribution in the chain reveals that the charge transfer is backward: the positive charge shifts in the opposite direction of the external electric field. Such a backward charge transfer (BCT) produces an opposite dipole, which makes the polarization negative. The effect of electron interaction on the BCT is illustrated.

  11. Logistic chain modelling

    NARCIS (Netherlands)

    Slats, P.A.; Bhola, B.; Evers, J.J.M.; Dijkhuizen, G.

    1995-01-01

    Logistic chain modelling is very important in improving the overall performance of the total logistic chain. Logistic models provide support for a large range of applications, such as analysing bottlenecks, improving customer service, configuring new logistic chains and adapting existing chains to n

  12. Health supply chain management.

    Science.gov (United States)

    Zimmerman, Rolf; Gallagher, Pat

    2010-01-01

    This chapter gives an educational overview of: * The actual application of supply chain practice and disciplines required for service delivery improvement within the current health environment. * A rationale for the application of Supply Chain Management (SCM) approaches to the Health sector. * The tools and methods available for supply chain analysis and benchmarking. * Key supply chain success factors.

  13. Synthesis, Thermal Processing, and Thin Film Morphology of Poly(3-hexylthiophene)-Poly(styrenesulfonate) Block Copolymers

    NARCIS (Netherlands)

    Erothu, Harikrishna; Kolomanska, Joanna; Johnston, Priscilla; Schumann, Stefan; Deribew, Dargie; Toolan, Daniel T. W.; Gregori, Alberto; Dagron-Lartigau, Christine; Portale, Giuseppe; Bras, Wim; Arnold, Thomas; Distler, Andreas; Hiorns, Roger C.; Mokarian-Tabari, Parvaneh; Collins, Timothy W.; Howse, Jonathan R.; Topham, Paul D.

    2015-01-01

    A series of novel block copolymers, processable from single organic solvents and subsequently rendered amphiphilic by thermolysis, have been synthesized using Grignard metathesis (GRIM) and reversible addition-fragmentation chain transfer (RAFT) polymerizations and azide-alkyne click chemistry. This

  14. Radionuclide transfer. Radionuklid Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, G.B.

    1993-01-01

    The research project described here had the aim to obtain further information on the transfer of nuclides during pregnancy and lactation. The tests were carried out in mini-pigs and rats receiving unchanging doses of radionuclides with the food. The following findings were revealed for the elements examined: Fe, Se, Cs and Zn were characterized by very high transfer levels in the mother, infant and foetus. A substantial uptake by the mother alone was observed for Co, Ag and Mn. The uptake by the foetus and infant here was 1 to 10 times lower. A preferential concentration in certain tissues was seen for Sr and Tc; the thyroid levels of Tc were about equally high in mothers and infants, while Sr showed less accumulation in the maternal bone. The lanthanide group of substances (Ce, Eu and Gd as well as Y and Ru) were only taken up to a very limited extent. The uptake of the examined radionuclides (Fe, Co, Ag, Ce) with the food ingested was found here to be ten times greater in rats as compared to mini-pigs. This showed that great caution must be observed, if the behaviour of radionuclides in man is extrapolated from relevant data obtained in rodents. (orig./MG)

  15. Sustainable Supply Chain Design

    DEFF Research Database (Denmark)

    Bals, Lydia; Tate, Wendy

    to implement TBL goals across the supply chain. In supply chain design, the classic economic perspective still dominates, although the idea of the TBL is more widely disseminated. The purpose of this research is to add to the sustainable supply chain management literature (SSCM) research agenda......A significant conceptual and practical challenge is how to integrate triple bottom line (TBL; including economic, social and environmental) sustainability into global supply chains. Although this integration is necessary to slow down global resource depletion, understanding is limited of how...... by incorporating the physical chain, and the (information and financial) support chains into supply chain design. This manuscript tackles issues of what the chains are designed for and how they are designed structurally. Four sustainable businesses are used as illustrative case examples of innovative supply chain...

  16. Effects of Intrinsic Decoherence on Information Transport in a Spin Chain

    Institute of Scientific and Technical Information of China (English)

    ZENG Tian-Hai; SHAO Bin; ZOU Jian

    2009-01-01

    Considering Milburn's intrinsic decoherence effect on quantum communication through a spin chain, we show that the transfer quality for quantum state and entanglement will obviously decrease with the increasing intrinsic decoherence rate. Some odd chains are much higher than even ones for the state transfer efficiency. The state transfer of a long chain is very sensitive to the intrinsic decoherence, which turns out to be an obstacle for information transport.

  17. Drying of willow biomass in supply chains

    NARCIS (Netherlands)

    Gigler, J.K.

    2000-01-01

    The drying process of willow ( Salix viminalis ) in biomass supply chains to energy plants is quantitatively described. Drying at particle level was modelled for chips and stems by a diffusion equation linked to the mass transfer of moisture to the air. Drying at bulk level is described by a deep be

  18. Failures in combined knowledge and material supply chains

    DEFF Research Database (Denmark)

    Koch, Christian

    2005-01-01

    stream and then occasionally transfer into the material stream. The paper proposes initiatives to strengthen partnerships in supply chains and especially at engineer to order production. The contradiction between the permanent enterprise organisation potentially capable of handling purchasing...

  19. New acceptor-bridge-donor strategy for enhancing NLO response with long-range excess electron transfer from the NH2...M/M3O donor (M = Li, Na, K) to inside the electron hole cage C20F19 acceptor through the unusual σ chain bridge (CH2)4.

    Science.gov (United States)

    Bai, Yang; Zhou, Zhong-Jun; Wang, Jia-Jun; Li, Ying; Wu, Di; Chen, Wei; Li, Zhi-Ru; Sun, Chia-Chung

    2013-04-01

    Using the strong electron hole cage C20F19 acceptor, the NH2...M/M3O (M = Li, Na, and K) complicated donors with excess electron, and the unusual σ chain (CH2)4 bridge, we construct a new kind of electride molecular salt e(-)@C20F19-(CH2)4-NH2...M(+)/M3O(+) (M = Li, Na, and K) with excess electron anion inside the hole cage (to be encapsulated excess electron-hole pair) serving as a new A-B-D strategy for enhancing nonlinear optical (NLO) response. An interesting push-pull mechanism of excess electron generation and its long-range transfer is exhibited. The excess electron is pushed out from the (super)alkali atom M/M3O by the lone pair of NH2 in the donor and further pulled inside the hole cage C20F19 acceptor through the efficient long σ chain (CH2)4 bridge. Owing to the long-range electron transfer, the new designed electride molecular salts with the excess electron-hole pair exhibit large NLO response. For the e(-)@C20F19-(CH2)4-NH2...Na(+), its large first hyperpolarizability (β0) reaches up to 9.5 × 10(6) au, which is about 2.4 × 10(4) times the 400 au for the relative e(-)@C20F20...Na(+) without the extended chain (CH2)4-NH2. It is shown that the new strategy is considerably efficient in enhancing the NLO response for the salts. In addition, the effects of different bridges and alkali atomic number on β0 are also exhibited. Further, three modulating factors are found for enhancing NLO response. They are the σ chain bridge, bridge-end group with lone pair, and (super)alkali atom. The new knowledge may be significant for designing new NLO materials and electronic devices with electrons inside the cages. They may also be the basis of establishing potential organic chemistry with electron-hole pair.

  20. Transfer Pricing

    DEFF Research Database (Denmark)

    Nielsen, Søren Bo

    2014-01-01

    Against a background of rather mixed evidence about transfer pricing practices in multinational enterprises (MNEs) and varying attitudes on the part of tax authorities, this paper explores how multiple aims in transfer pricing can be pursued across four different transfer pricing regimes. A MNE h...

  1. The Global Value Chain

    DEFF Research Database (Denmark)

    Sørensen, Olav Jull

    The conference paper aims to develop the global value chain concept by including corporate internal value adding activities and competition to the basic framework in order to turn the global value chain into a strategic management tool......The conference paper aims to develop the global value chain concept by including corporate internal value adding activities and competition to the basic framework in order to turn the global value chain into a strategic management tool...

  2. Serum Free Light Chains

    Science.gov (United States)

    ... or of one of its component parts – a kappa or lambda light chain, or rarely, a heavy chain. Traditionally, plasma cell ... protein (M-protein) production and to calculate a kappa/lambda free light chain ratio. If the protein electrophoresis test is abnormal, ...

  3. Characterization of the respiratory chain of Helicobacter pylori

    DEFF Research Database (Denmark)

    Chen, M; Andersen, L P; Zhai, L

    1999-01-01

    The respiratory chain of Helicobacter pylori has been investigated. The total insensitivity of activities of NADH dehydrogenase to rotenone and of NADH-cytochrome c reductase to antimycin is indicative of the absence of the classical complex I of the electron transfer chain in this bacterium. NADPH...

  4. Respiratory electron transfer in Escherichia coli : components, energetics and regulation

    NARCIS (Netherlands)

    Bekker, M.

    2009-01-01

    The respiratory chain that is housed in the bacterial cytoplasmic membrane, generally transfers electrons from NADH to oxygen; in the absence of oxygen it can use several alternative electron acceptors, such as nitrate and fumarate. Transfer of electrons through this chain is usually coupled to the

  5. Gushing metal chain

    Science.gov (United States)

    Belyaev, Alexander; Sukhanov, Alexander; Tsvetkov, Alexander

    2016-03-01

    This article addresses the problem in which a chain falls from a glass from some height. This phenomenon demonstrates a paradoxical rise of the chain over the glass. To explain this effect, an initial hypothesis and an appropriate theory are proposed for calculating the steady fall parameters of the chain. For this purpose, the modified Cayley's problem of falling chain given its rise due to the centrifugal force of upward inertia is solved. Results show that the lift caused by an increase in linear density at the part of chain where it is being bent (the upper part) is due to the convergence of the chain balls to one another. The experiments confirm the obtained estimates of the lifting chain.

  6. Report on tool transfer and alignment methods

    DEFF Research Database (Denmark)

    Tosello, Guido; Gasparin, Stefania; De Grave, Arnaud;

    2010-01-01

    the accuracy of the hybrid tooling process chain with a focus on the part transfer and re-position of different machining chains have not been addressed thoroughly and are the topic of Task 2.2.3 “Tool transfer for hybrid manufacturing”. First results are presented in this report, focussing on a specific......In the last few years, research work has been carried out regarding the feature miniaturization and tooling performance achievable with specific process chains combining different micro machining processes. On the other hand, technologies, strategies and tool design rules in order to optimize...

  7. Ecosystem-based approach for the numerical modelling of {sup 137}Cs transfer to the western North Pacific plankton populations after the Fukushima nuclear power plant accident - New approach for the modelling of radiocesium in pelagic food chain in the Northwestern Pacific after the Fukushima nuclear power plant accident

    Energy Technology Data Exchange (ETDEWEB)

    Belharet, Mokrane [Institut de Radioprotection et de Surete Nucleaire, SESURE/ LERCM, 83507 La Seyne-sur-mer (France); Laboratoire d' Aerologie, 14 av Eduard Belin, 31400 Toulouse (France); Estournel, Claude [Laboratoire d' Aerologie, 14 av Eduard Belin, 31400 Toulouse (France); Charmasson, Sabine [Institut de Radioprotection et de Surete Nucleaire, SESURE/ LERCM, 83507 La Seyne-sur-mer (France)

    2014-07-01

    Huge quantities of radiocesium ({sup 134}Cs and {sup 137}Cs) were released to the coastal northwestern Pacific ocean after the Fukushima nuclear power plant accident, that occurred on 11 March 2011. The resultant radiocesium contamination was quickly transferred to marine biota resulting in elevated cesium levels measured in various organisms sampled over this area. This study aims to understand the mechanism of radiocesium behavior in the marine food chain under this non steady state situation (accident) and to estimate contamination levels in these organisms, by using a new modelling approach based on the coupling of three different models: a model of cesium dispersion in the ocean, an ecosystem model and a radioecological model. The model was run for 2 years (2011 and 2012) and was first applied to study marine plankton and planktonivorous fishes contamination. Results of spatio-temporal radiocesium activities in these different organisms, and calculated parameters like concentration ratios, biological half-lives, percentages of contamination coming from each compartment (food and water), and trophic transfer factors were compared to the observed values acquired before and after the accident (steady and non-steady states). (authors)

  8. Supply Chain Management og Supply Chain costing

    DEFF Research Database (Denmark)

    Nielsen, Steen; Mortensen, Ole

    2002-01-01

    Formålet med denne artikel er at belyse de muligheder som ligger i at integrere virksomhedens økonomiske styring med begrebet Supply Chain Management (SCM). Dette søges belyst ved først at beskrive den teoretiske ramme, hvori SCM indgår. Herefter analyseres begrebet Supply Chain Costing (SCC) som...... Århus. Et resultat er, at via begrebet Supply Chain Costing skabes der mulighed for at måle logistikkædens aktiviteter i kr./øre. Anvendelsen af denne information har også strategisk betydning for at kunne vælge kunde og leverandør. Ved hjælp af integrationen skabes der også helt nye mulighed...

  9. Understanding the Chain Fountain

    CERN Document Server

    Biggins, John Simeon

    2013-01-01

    If a chain is initially at rest in a beaker at a height h1 above the ground, and the end of the chain is pulled over the rim of the beaker and down towards the ground and then released, the chain will spontaneously "flow" out of the beaker under gravity. Furthermore, if h1 is sufficient, the beads do not simply drag over the edge of the beaker but form a fountain reaching a height h2 above it. We show that the formation of a fountain requires that the beads come into motion not only by being pulled upwards by the part of the chain immediately above the pile, but also by being pushed upwards by an anomalous reaction force from the pile of stationary chain. We propose possible origins for this force, argue that its magnitude will be proportional to the square of the chain velocity, and predict and verify experimentally that h2 is proportional to h1.

  10. The NDUFB6 subunit of the mitochondrial respiratory chain complex I is required for electron transfer activity: A proof of principle study on stable and controlled RNA interference in human cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Loublier, Sandrine; Bayot, Aurelien; Rak, Malgorzata; El-Khoury, Riyad; Benit, Paule [Inserm U676, Hopital Robert Debre, F-75019 Paris (France); Universite Paris 7, Faculte de medecine Denis Diderot, IFR02 Paris (France); Rustin, Pierre, E-mail: pierre.rustin@inserm.fr [Inserm U676, Hopital Robert Debre, F-75019 Paris (France); Universite Paris 7, Faculte de medecine Denis Diderot, IFR02 Paris (France)

    2011-10-22

    Highlights: {yields} NDUFB6 is required for activity of mitochondrial complex I in human cell lines. {yields} Lentivirus based RNA interference results in frequent off target insertions. {yields} Flp-In recombinase mediated miRNA insertion allows gene-specific extinction. -- Abstract: Molecular bases of inherited deficiencies of mitochondrial respiratory chain complex I are still unknown in a high proportion of patients. Among 45 subunits making up this large complex, more than half has unknown function(s). Understanding the function of these subunits would contribute to our knowledge on mitochondrial physiology but might also reveal that some of these subunits are not required for the catalytic activity of the complex. A direct consequence of this finding would be the reduction of the number of candidate genes to be sequenced in patients with decreased complex I activity. In this study, we tested two different methods to stably extinct complex I subunits in cultured cells. We first found that lentivirus-mediated shRNA expression frequently resulted in the unpredicted extinction of additional gene(s) beside targeted ones. This can be ascribed to uncontrolled genetic material insertions in the genome of the host cell. This approach thus appeared inappropriate to study unknown functions of a gene. Next, we found it possible to specifically extinct a CI subunit gene by direct insertion of a miR targeting CI subunits in a Flp site (HEK293 Flp-In cells). By using this strategy we unambiguously demonstrated that the NDUFB6 subunit is required for complex I activity, and defined conditions suitable to undertake a systematic and stable extinction of the different supernumerary subunits in human cells.

  11. Food supply chains

    OpenAIRE

    Zhou, Qian

    2011-01-01

    The dissertation analyses food waste in global supply chain. From the related managerial literature, the process of supply chain operation, from agriculture, manufacturing, warehouses, retailers to customers are explained clearly. Then the reasons and characteristics of food wastes in any point of food supply chain are analyzed. From some case studies and questionnaire investigation, some corresponding methods to reduce food waste are put forward in the following. Lastly, in terms of method s...

  12. Supply chain components

    Directory of Open Access Journals (Sweden)

    Vieraşu, T.

    2011-01-01

    Full Text Available In this article I will go through three main logistics components, which are represented by: transportation, inventory and facilities, and the three secondary logistical components: information, production location, price and how they determine performance of any supply chain. I will discuss then how these components are used in the design, planning and operation of a supply chain. I will also talk about some obstacles a supply chain manager may encounter.

  13. Transfer Pricing

    DEFF Research Database (Denmark)

    Rohde, Carsten; Rossing, Christian Plesner

    trade internally as the units have to decide what prices should be paid for such inter-unit transfers. One important challenge is to uncover the consequences that different transfer prices have on the willingness in the organizational units to coordinate activities and trade internally. At the same time...

  14. Quantum spin transistor with a Heisenberg spin chain

    Science.gov (United States)

    Marchukov, O. V.; Volosniev, A. G.; Valiente, M.; Petrosyan, D.; Zinner, N. T.

    2016-10-01

    Spin chains are paradigmatic systems for the studies of quantum phases and phase transitions, and for quantum information applications, including quantum computation and short-distance quantum communication. Here we propose and analyse a scheme for conditional state transfer in a Heisenberg XXZ spin chain which realizes a quantum spin transistor. In our scheme, the absence or presence of a control spin excitation in the central gate part of the spin chain results in either perfect transfer of an arbitrary state of a target spin between the weakly coupled input and output ports, or its complete blockade at the input port. We also discuss a possible proof-of-concept realization of the corresponding spin chain with a one-dimensional ensemble of cold atoms with strong contact interactions. Our scheme is generally applicable to various implementations of tunable spin chains, and it paves the way for the realization of integrated quantum logic elements.

  15. Quantum spin transistor with a Heisenberg spin chain

    Science.gov (United States)

    Marchukov, O. V.; Volosniev, A. G.; Valiente, M.; Petrosyan, D.; Zinner, N. T.

    2016-01-01

    Spin chains are paradigmatic systems for the studies of quantum phases and phase transitions, and for quantum information applications, including quantum computation and short-distance quantum communication. Here we propose and analyse a scheme for conditional state transfer in a Heisenberg XXZ spin chain which realizes a quantum spin transistor. In our scheme, the absence or presence of a control spin excitation in the central gate part of the spin chain results in either perfect transfer of an arbitrary state of a target spin between the weakly coupled input and output ports, or its complete blockade at the input port. We also discuss a possible proof-of-concept realization of the corresponding spin chain with a one-dimensional ensemble of cold atoms with strong contact interactions. Our scheme is generally applicable to various implementations of tunable spin chains, and it paves the way for the realization of integrated quantum logic elements. PMID:27721438

  16. Supply chain planning classification

    Science.gov (United States)

    Hvolby, Hans-Henrik; Trienekens, Jacques; Bonde, Hans

    2001-10-01

    Industry experience a need to shift in focus from internal production planning towards planning in the supply network. In this respect customer oriented thinking becomes almost a common good amongst companies in the supply network. An increase in the use of information technology is needed to enable companies to better tune their production planning with customers and suppliers. Information technology opportunities and supply chain planning systems facilitate companies to monitor and control their supplier network. In spite if these developments, most links in today's supply chains make individual plans, because the real demand information is not available throughout the chain. The current systems and processes of the supply chains are not designed to meet the requirements now placed upon them. For long term relationships with suppliers and customers, an integrated decision-making process is needed in order to obtain a satisfactory result for all parties. Especially when customized production and short lead-time is in focus. An effective value chain makes inventory available and visible among the value chain members, minimizes response time and optimizes total inventory value held throughout the chain. In this paper a supply chain planning classification grid is presented based current manufacturing classifications and supply chain planning initiatives.

  17. Interaction of poxvirus intracellular mature virion proteins with the TPR domain of kinesin light chain in live infected cells revealed by two-photon-induced fluorescence resonance energy transfer fluorescence lifetime imaging microscopy.

    Science.gov (United States)

    Jeshtadi, Ananya; Burgos, Pierre; Stubbs, Christopher D; Parker, Anthony W; King, Linda A; Skinner, Michael A; Botchway, Stanley W

    2010-12-01

    Using two-photon-induced fluorescence lifetime imaging microscopy, we corroborate an interaction (previously demonstrated by yeast two-hybrid domain analysis) of full-length vaccinia virus (VACV; an orthopoxvirus) A36 protein with the cellular microtubule motor protein kinesin. Quenching of enhanced green fluorescent protein (EGFP), fused to the C terminus of VACV A36, by monomeric red fluorescent protein (mDsRed), fused to the tetratricopeptide repeat (TPR) domain of kinesin, was observed in live chicken embryo fibroblasts infected with either modified vaccinia virus Ankara (MVA) or wild-type fowlpox virus (FWPV; an avipoxvirus), and the excited-state fluorescence lifetime of EGFP was reduced from 2.5 ± 0.1 ns to 2.1 ± 0.1 ns due to resonance energy transfer to mDsRed. FWPV does not encode an equivalent of intracellular enveloped virion surface protein A36, yet it is likely that this virus too must interact with kinesin to facilitate intracellular virion transport. To investigate possible interactions between innate FWPV proteins and kinesin, recombinant FWPVs expressing EGFP fused to the N termini of FWPV structural proteins Fpv140, Fpv168, Fpv191, and Fpv198 (equivalent to VACV H3, A4, p4c, and A34, respectively) were generated. EGFP fusions of intracellular mature virion (IMV) surface protein Fpv140 and type II membrane protein Fpv198 were quenched by mDsRed-TPR in recombinant FWPV-infected cells, indicating that these virion proteins are found within 10 nm of mDsRed-TPR. In contrast, and as expected, EGFP fusions of the IMV core protein Fpv168 did not show any quenching. Interestingly, the p4c-like protein Fpv191, which demonstrates late association with preassembled IMV, also did not show any quenching.

  18. Independent sets in chain cacti

    CERN Document Server

    Sedlar, Jelena

    2011-01-01

    In this paper chain cacti are considered. First, for two specific classes of chain cacti (orto-chains and meta-chains of cycles with h vertices) the recurrence relation for independence polynomial is derived. That recurrence relation is then used in deriving explicit expressions for independence number and number of maximum independent sets for such chains. Also, the recurrence relation for total number of independent sets for such graphs is derived. Finaly, the proof is provided that orto-chains and meta-chains are the only extremal chain cacti with respect to total number of independent sets (orto-chains minimal and meta-chains maximal).

  19. "Transfer Shock" or "Transfer Ecstasy?"

    Science.gov (United States)

    Nickens, John M.

    The alleged characteristic drop in grade point average (GPA) of transfer students and the subsequent rise in GPA was investigated in this study. No statistically significant difference was found in first term junior year GPA between junior college transfers and native Florida State University students after the variance accounted for by the…

  20. Decisive Markov Chains

    CERN Document Server

    Abdulla, Parosh Aziz; Mayr, Richard

    2007-01-01

    We consider qualitative and quantitative verification problems for infinite-state Markov chains. We call a Markov chain decisive w.r.t. a given set of target states F if it almost certainly eventually reaches either F or a state from which F can no longer be reached. While all finite Markov chains are trivially decisive (for every set F), this also holds for many classes of infinite Markov chains. Infinite Markov chains which contain a finite attractor are decisive w.r.t. every set F. In particular, this holds for probabilistic lossy channel systems (PLCS). Furthermore, all globally coarse Markov chains are decisive. This class includes probabilistic vector addition systems (PVASS) and probabilistic noisy Turing machines (PNTM). We consider both safety and liveness problems for decisive Markov chains, i.e., the probabilities that a given set of states F is eventually reached or reached infinitely often, respectively. 1. We express the qualitative problems in abstract terms for decisive Markov chains, and show...

  1. Fields From Markov Chains

    DEFF Research Database (Denmark)

    Justesen, Jørn

    2005-01-01

    A simple construction of two-dimensional (2-D) fields is presented. Rows and columns are outcomes of the same Markov chain. The entropy can be calculated explicitly.......A simple construction of two-dimensional (2-D) fields is presented. Rows and columns are outcomes of the same Markov chain. The entropy can be calculated explicitly....

  2. REVERSE SUPPLY CHAIN

    Directory of Open Access Journals (Sweden)

    Tomasz DOMAGAŁA

    2013-10-01

    Full Text Available The paper focuses on the presentation of the reverse supply chain, of which the role in the modern business grows along with the increasing number of environmental regulations and possibilities of reducing an operating cost. The paper also describes main problems in developing the profitable chain and possibilities to take an action in order to overcome them.

  3. Value Chain Engineering

    DEFF Research Database (Denmark)

    Wæhrens, Brian Vejrum; Slepniov, Dmitrij

    2015-01-01

    This workbook is recommended for the attention of students of and managers in Danish small and medium sized enterprises (SMEs). Danish SMEs are currently facing a number of key challenges related to their position in global value chains. This book provides an insight into value chain management...

  4. Supply Chain Management

    DEFF Research Database (Denmark)

    Wieland, Andreas; Handfield, Robert B.

    Supply chain management has made great strides in becoming a discipline with a standalone body of theories. As part of this evolution, researchers have sought to embed and integrate observed supply chain management phenomena into theoretical statements. In our review, we explore where we have been...

  5. Supply Chain Connectivity: Enhancing Participation in the Global Supply Chain

    OpenAIRE

    Epictetus E. Patalinghug

    2015-01-01

    Supply chain connectivity is vital for the efficient flow of trade among APEC economies. This paper reviews the literature and supply chain management, describes the barriers to enhancing participation in global supply chain, analyzes the various measures of supply chain performance, and suggests steps for the Philippines to fully reap the benefits of the global value chain.

  6. Valuation of a transfer in a multimodal public transport trip

    NARCIS (Netherlands)

    Schakenbos, R.; La Paix Puello, L.C.; Nijenstein, S.; Geurs, K.T.

    2016-01-01

    Improvement of chain mobility is considered a major issue in public transport use. Transfers within a public transport trip are the least appreciated part of the trip. This research quantifies the experienced transfer disutility of a transfer between BTM and train. The influence of travel time, tran

  7. Kinetic chain abnormalities in the athletic shoulder.

    Science.gov (United States)

    Sciascia, Aaron; Thigpen, Charles; Namdari, Surena; Baldwin, Keith

    2012-03-01

    Overhead activities require the shoulder to be exposed to and sustain repetitive loads. The segmental activation of the body's links, known as the kinetic chain, allows this to occur effectively. Proper muscle activation is achieved through generation of energy from the central segment or core, which then transfers the energy to the terminal links of the shoulder, elbow, and hand. The kinetic chain is best characterized by 3 components: optimized anatomy, reproducible efficient motor patterns, and the sequential generation of forces. However, tissue injury and anatomic deficits such as weakness and/or tightness in the leg, pelvic core, or scapular musculature can lead to overuse shoulder injuries. These injuries can be prevented and maladaptations can be detected with a thorough understanding of biomechanics of the kinetic chain as it relates to overhead activity.

  8. Electronic bistability in linear beryllium chains.

    Science.gov (United States)

    Helal, Wissam; Monari, Antonio; Evangelisti, Stefano; Leininger, Thierry

    2009-04-30

    A theoretical investigation on the mixed-valence behavior (bistability) of a series of cationic linear chains composed of beryllium atoms, Be(N)(+) (with N = 6,..., 12), is presented. The calculations were performed at CAS-SCF and MR-CI levels by using an ANO basis set containing 6s4p3d2f orbitals for each atom. Our results show a consistent gradual shift between different classes of mixed-valence compounds as the number of beryllium atoms increases, from class III strong coupling toward class II valence trapped. Indeed, in the largest cases (N > 10), the cationic chains were found to be closer to class I, where the coupling vanishes. The intramolecular electron transfer parameters V(ab), E(a), and E(opt) were calculated for each atomic chain. It is shown that the decrease of V(ab) with increasing N follows an exponential pattern.

  9. The electronic properties of a Fibonacci chain

    Directory of Open Access Journals (Sweden)

    S. A. Ketabi

    2004-12-01

    Full Text Available  Using a tight-binding model and transfer-matrix technique, as well as Lanczos algorithm, we numerically investigate the nature of the electronic states and electron transmission in site, bond and mixing Fibonacci model chains. We rely on the Landauer formalism as the basis for studying the conduction properties of these systems. Calculating the Lyapunov exponent, we also study the localization properties of electronic eigenstates in the Fibonacci chains. The focus is on the significance of the relationship between the transmission spectra and the nature of the electronic states. Our results show that, in contrast to Anderson’s localization theorem, in the Fibonacci chains the electronic states are non-localized and the transparent states occurr near the Fermi level.

  10. The Relationship between Organizational Transfer Climate and Positive Transfer of Training.

    Science.gov (United States)

    Rouiller, Janice Z; Goldstein, Irwin L.

    1993-01-01

    After a 9-week training course, 102 manager trainees in a fast-food chain were assigned to restaurants. Those assigned to units having positive organizational transfer climate (measured by situational cues and consequences) were rated as better performers. Climate affected the degree to which learned behavior was transferred to the actual job. (SK)

  11. Customer-Driven Supply Chains From Glass Pipelines to Open Innovation Networks

    CERN Document Server

    Lyons, Andrew C; Piller, Frank; Poler, Raúl

    2012-01-01

    In recent years, the supply chain has become a key element to the survival and prosperity of organisations in different industry sectors. Organisations dealing in dynamic business environments demand supply chains that support the satisfaction of customer needs. The principles of lean thinking that once permeated standalone organisations have now been transferred to the supply chain, making imperative the development of innovative approaches to supply chain management.    Customer-Driven Supply Chains: From Glass Pipelines to Open Innovation Networks reviews the concept of lean thinking and its relationship to other key initiatives associated with supply chain management. Detailed industrial case studies based on the authors’ experience illustrate the principles behind lean supply chains. Moreover, a series of diagrams are used to illustrate critical concepts and supply chain architectures. Special emphasis is placed on the importance of transferring lean principles from the organisational level to the s...

  12. Project Decision Chain

    DEFF Research Database (Denmark)

    Rolstadås, Asbjørn; Pinto, Jeffrey K.; Falster, Peter

    2015-01-01

    To add value to project performance and help obtain project success, a new framework for decision making in projects is defined. It introduces the project decision chain inspired by the supply chain thinking in the manufacturing sector and uses three types of decisions: authorization, selection......, and plan decision. A primitive decision element is defined where all the three decision types can be accommodated. Each task in the primitive element can in itself contain subtasks that in turn will comprise new primitive elements. The primitive elements are nested together in a project decision chain....

  13. Plastic value chains

    DEFF Research Database (Denmark)

    Baxter, John; Wahlstrom, Margareta; Zu Castell-Rüdenhausen, Malin

    2014-01-01

    Optimizing plastic value chains is regarded as an important measure in order to increase recycling of plastics in an efficient way. This can also lead to improved awareness of the hazardous substances contained in plastic waste, and how to avoid that these substances are recycled. As an example......, plastics from WEEE is chosen as a Nordic case study. The project aims to propose a number of improvements for this value chain together with representatives from Nordic stakeholders. Based on the experiences made, a guide for other plastic value chains shall be developed....

  14. Research on Knowledge-Oriented Supply ChainRisk Management System Model

    OpenAIRE

    Yingchun Guo

    2011-01-01

    Based on analyzing the characteristics of supply chain risk management under the influences of knowledge, in this paper integrates basic theories and methods of knowledge management into the process of risk management, builds a knowledge-oriented supply chain risk management system model, and proposes relevant strategies, presenting references for practical application of knowledge-oriented supply chain risk management. By means of acquiring, storing, sharing, and transferring supply chain ri...

  15. Supply chain risk management

    Directory of Open Access Journals (Sweden)

    Christian Hollstein

    2013-03-01

    Full Text Available Background: Supply chain risk management increasingly gains prominence in many international industries. In order to strengthen supply chain structures, processes, and networks, adequate potentials for risk management need to be built (focus on effective logistics and to be utilized (focus on efficient logistics. Natural-based disasters, such as the case of Fukushima, illustrate how crucial risk management is. Method: By aligning a theoretical-conceptual framework with empirical-inductive findings, it may be hypothesized that logistical systems do have a positive effect on supply chain risk management activities.  Result/conclusion:  Flexibility and capacity, as well as redundancy and standardization, are often viewed as being conflictionary. It shows, however, that in the light of supply chain risk management, those factors may yield a common benefit if proper logistics systems are applied.  

  16. Editorial: Supply Chain Management

    Directory of Open Access Journals (Sweden)

    Aidonis, D.

    2012-01-01

    Full Text Available This special issue has followed up the 2nd Olympus International Conference on Supply Chains held on October 5-6, 2012, in Katerini, Greece. The Conference was organized by the Department of Logistics of Alexander Technological Educational Institution (ATEI of Thessaloniki, in collaboration with the Laboratory of Quantitative Analysis, Logistics and Supply Chain Management of the Department of Mechanical Engineering, Aristotle University of Thessaloniki (AUTH. During the 2-Days Conference more than 50 research papers were presented covering the following thematic areas: (i Business Logistics, (ii Transportation, Telematics and Distribution Networks, (iii Green Logistics, (iv Information and Communication Technologies in Supply Chain Management, and (v Services and Quality. Three keynote invited speakers addressed interesting issues for the Humanitarian Logistics, Green Supply Chains of the Agrifood Sector and the Opportunities and Prospects of Greek Ports chaired Round Tables with other Greek and Foreign Scientists and Specialists.

  17. Moldova - Value Chain Training

    Data.gov (United States)

    Millennium Challenge Corporation — The evaluation of the GHS value chain training subactivity wwas designed to measure the extent, if any, to which the training activities improved the productivity...

  18. Light chain nephropathy

    Directory of Open Access Journals (Sweden)

    Sihem Darouich

    2015-01-01

    Full Text Available Light chain deposition disease (LCDD is characterized by the tissue deposition of monotypic immunoglobulin light chains of either kappa or lambda isotype. It is the archetypal systemic disease that is most frequently diagnosed on a kidney biopsy, although the deposits may involve several other organs. This brief review focuses on the clinicopathological features of LCDD-associated nephropathy with an emphasis on the diagnostic and therapeutic difficulties related to this elusive condition.

  19. Supply Chain Interoperability Measurement

    Science.gov (United States)

    2015-06-19

    Base, Ohio DISTRIBUTION STATEMENT A. APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. The views expressed in this thesis ...chain connections are often hindered by inconsistent vocabularies , terms, ontologies, and semantics utilized by various supply chain members (Ye et...eg.COOPERATION PROCESS)-Don’t address synergies between SC X X X X X X X X Don’t track effectiveness over time-lack of learning by experience Loss of SC

  20. Supply chain quality management

    OpenAIRE

    Hannan Amoozad Mahdiraji; Meysam Arabzadeh; Reza Ghaffari

    2012-01-01

    In recent years, there are several methods introduced for the improvement of operational performances. Total quality management and supply chain management are two methods recommended for this purpose. These two approaches have been studied in most researches separately, while they have objectives in common, and this makes them a strategic means, which can be used, simultaneously. Total quality management and supply chain management play significant roles to increase the organizational compet...

  1. Innovation Across the Supply Chain

    DEFF Research Database (Denmark)

    Druehl, Cheryl; Carrillo, Janice; Hsuan, Juliana

    Innovation is an integral part of every firm’s ongoing operations. Beyond product innovation, supply chain innovations offer a unique source of competitive advantage. We synthesize recent research on innovation in the supply chain, specifically, innovative supply chain processes...

  2. MASTERING SUPPLY CHAIN RISKS

    Directory of Open Access Journals (Sweden)

    Borut Jereb

    2012-11-01

    Full Text Available Risks in supply chains represent one of the major business issues today. Since every organizationstrives for success and uninterrupted operations, efficient supply chain risk management is crucial.During supply chain risk research at the Faculty of Logistics in Maribor (Slovenia some keyissues in the field were identified, the major being the lack of instruments which can make riskmanagement in an organization easier and more efficient. Consequently, a model which captures anddescribes risks in an organization and its supply chain was developed. It is in accordance with thegeneral risk management and supply chain security standards, the ISO 31000 and ISO 28000families. It also incorporates recent finding from the risk management field, especially from theviewpoint of segmenting of the public.The model described in this paper focuses on the risks itself by defining them by different keydimensions, so that risk management is simplified and can be undertaken in every supply chain andorganizations within them. Based on our mode and consequent practical research in actualorganizations, a freely accessible risk catalog has been assembled and published online from the risksthat have been identified so far. This catalog can serve as a checklist and a starting point in supplychain risk management in organizations. It also incorporates experts from the field into a community,in order to assemble an ever growing list of possible risks and to provide insight into the model andits value in practice.

  3. Issues on Supply Chain Management

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Although supply chain is regarded as an integrated pr ocess, actually, researchers and practitioners have primarily investigated the v arious processes of the supply chain individually. The competitive field in most markets requires well-designed integrated supply chain instead of individual o perations. In this paper, some traditional thinking of supply chain is given fir st, then SCM (Supply Chain Management) is introduced, which views the entire sup ply chain as a whole rather than individual process a...

  4. Technology Transfer

    Science.gov (United States)

    Smith, Nanette R.

    1995-01-01

    The objective of this summer's work was to attempt to enhance Technology Application Group (TAG) ability to measure the outcomes of its efforts to transfer NASA technology. By reviewing existing literature, by explaining the economic principles involved in evaluating the economic impact of technology transfer, and by investigating the LaRC processes our William & Mary team has been able to lead this important discussion. In reviewing the existing literature, we identified many of the metrics that are currently being used in the area of technology transfer. Learning about the LaRC technology transfer processes and the metrics currently used to track the transfer process enabled us to compare other R&D facilities to LaRC. We discuss and diagram impacts of technology transfer in the short run and the long run. Significantly, it serves as the basis for analysis and provides guidance in thinking about what the measurement objectives ought to be. By focusing on the SBIR Program, valuable information regarding the strengths and weaknesses of this LaRC program are to be gained. A survey was developed to ask probing questions regarding SBIR contractors' experience with the program. Specifically we are interested in finding out whether the SBIR Program is accomplishing its mission, if the SBIR companies are providing the needed innovations specified by NASA and to what extent those innovations have led to commercial success. We also developed a survey to ask COTR's, who are NASA employees acting as technical advisors to the SBIR contractors, the same type of questions, evaluating the successes and problems with the SBIR Program as they see it. This survey was developed to be implemented interactively on computer. It is our hope that the statistical and econometric studies that can be done on the data collected from all of these sources will provide insight regarding the direction to take in developing systematic evaluations of programs like the SBIR Program so that they can

  5. State transfer in intrinsic decoherence spin channels

    CERN Document Server

    Hu, Ming-Liang; 10.1140/epjd/e2009-00220-8

    2011-01-01

    By analytically solving the master equation, we investigate quantum state transfer, creation and distribution of entanglement in the model of Milburn's intrinsic decoherence. Our results reveal that the ideal spin channels will be destroyed by the intrinsic decoherence environment, and the detrimental effects become severe as the decoherence rate $\\gamma$ and the spin chain length $N$ increase. For infinite evolution time, both the state transfer fidelity and the concurrence of the created and distributed entanglement approach steady state values, which are independent of the decoherence rate $\\gamma$ and decrease as the spin chain length $N$ increases. Finally, we present two modified spin chains which may serve as near perfect spin channels for long distance state transfer even in the presence of intrinsic decoherence environments $\\mathcal {F}{[\\rho(t)]}$.

  6. Blastocyst Transfer

    OpenAIRE

    sprotocols

    2014-01-01

    ### Method: Blastocyst transfer is usually performed 24 hours after aggregation when the morulae have become expanded blastocysts and on the same day as injection. A little time is given between injection and transfer to allow blastocysts to re-expand. **The Recipient** Careful selection of the recipient is most important as the pups are the end result of a lot of hard work. Two strains of mice are used:RB Swiss and (CBA*C57BL6/J)f1. RB Swiss are quiet and make excellent mothers ...

  7. Heat transfer

    CERN Document Server

    Holman, J P

    2010-01-01

    As one of the most popular heat transfer texts, Jack Holman's "Heat Transfer" is noted for its clarity, accessible approach, and inclusion of many examples and problem sets. The new tenth edition retains the straight-forward, to-the-point writing style while covering both analytical and empirical approaches to the subject. Throughout the book, emphasis is placed on physical understanding while, at the same time, relying on meaningful experimental data in those situations that do not permit a simple analytical solution. New examples and templates provide students with updated resources for computer-numerical solutions.

  8. Sophisticated transfer

    NARCIS (Netherlands)

    Reinhart, T.

    2006-01-01

    On the eve of the Iraq war, fears were expressed in different circles that under the cover of war, Israel may attempt a transfer of Palestinians in the “seam line” area of the northern West Bank (Kalkilya, Tulkarem). Last week, the army produced a scene from this scenario. On April 2 at 3 AM, a larg

  9. Facilitating Transfers

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    that the essential functional and normative purpose of regulatory governance is to facilitate, stabilise and justify the transfer of condensed social components (such as economic capital and products, political decisions, legal judgements, religious beliefs and scientific knowledge) from one social contexts...

  10. Phasic Triplet Markov Chains.

    Science.gov (United States)

    El Yazid Boudaren, Mohamed; Monfrini, Emmanuel; Pieczynski, Wojciech; Aïssani, Amar

    2014-11-01

    Hidden Markov chains have been shown to be inadequate for data modeling under some complex conditions. In this work, we address the problem of statistical modeling of phenomena involving two heterogeneous system states. Such phenomena may arise in biology or communications, among other fields. Namely, we consider that a sequence of meaningful words is to be searched within a whole observation that also contains arbitrary one-by-one symbols. Moreover, a word may be interrupted at some site to be carried on later. Applying plain hidden Markov chains to such data, while ignoring their specificity, yields unsatisfactory results. The Phasic triplet Markov chain, proposed in this paper, overcomes this difficulty by means of an auxiliary underlying process in accordance with the triplet Markov chains theory. Related Bayesian restoration techniques and parameters estimation procedures according to the new model are then described. Finally, to assess the performance of the proposed model against the conventional hidden Markov chain model, experiments are conducted on synthetic and real data.

  11. Spatial Data Supply Chains

    Science.gov (United States)

    Varadharajulu, P.; Azeem Saqiq, M.; Yu, F.; McMeekin, D. A.; West, G.; Arnold, L.; Moncrieff, S.

    2015-06-01

    This paper describes current research into the supply of spatial data to the end user in as close to real time as possible via the World Wide Web. The Spatial Data Infrastructure paradigm has been discussed since the early 1990s. The concept has evolved significantly since then but has almost always examined data from the perspective of the supplier. It has been a supplier driven focus rather than a user driven focus. The current research being conducted is making a paradigm shift and looking at the supply of spatial data as a supply chain, similar to a manufacturing supply chain in which users play a significant part. A comprehensive consultation process took place within Australia and New Zealand incorporating a large number of stakeholders. Three research projects that have arisen from this consultation process are examining Spatial Data Supply Chains within Australia and New Zealand and are discussed within this paper.

  12. Environmental Retail Supply Chains

    DEFF Research Database (Denmark)

    Kotzab, Herbert; Munch, Hilde; de Faultrier, Birgitte;

    2011-01-01

    Purpose – The purpose of this paper is to develop a scale that evaluates the environmental elements in retail supply chains and to examine the environmental supply chain management initiatives of the world's largest 100 retailing companies. Design/methodology/approach – The empirical evaluation has...... short-term oriented (green operations). Long-term oriented green design initiatives were hardly observed. Furthermore, the specific environmental activities of three retailers from Denmark, France and the UK were compared. Research limitations/implications – The empirical study investigates supply chain...... operations of retailers and excludes other areas of retail management. The results are based on material that is published by the respective companies and thus do not include internal reports. Originality/value – The main contribution of this paper is to test the proposition that global retailers follow...

  13. 技术转移视角下全产业链创新网络的行为模式:融合创新--以苹果公司网络为例%Behavior Patterns Based on Technology Transfer of the Innovation Networks of Whole Industry Chain is Integration and Innovation, Apple's Network as an Example

    Institute of Scientific and Technical Information of China (English)

    黄磊; 刘则渊; 姜照华

    2014-01-01

    Based on the practical implications of characterization of variables on network self-citation rate and cita-tions within the network, behavior patterns of innovation networks of whole industry chain and core business in network is integration and innovation of internal and external technical. Behavior characteristic, way flow of knowl-edge of based on technology transfer and operation mechanism and linkages of micro and macro levels to be ana-lyzed. Dominant behavior patterns of innovation networks and core business is innovation patterns based on exter-nal technology. According to autoregressive distributed lag model (ardl), characterization of behavioral variables on since number of patents cited of network and number of patents cited in the network is a lag effect for total number of patents of network. According to method of least squares, regression analysis of three variables is sig-nificant. According to the above analysis, behavior patterns of innovation networks of whole industry chain are in-tegration and innovation of significant.%研究了根据网络自引率和网络内引用率表征的实际含义,得出全产业链创新网络和网络内核心企业的行为模式:外部技术和内部技术相融合的融合创新模式。分析了融合创新行为模式的特性、基于技术转移的知识流动方式与微观和宏观两个层次的运行机理和相互联系。得到创新网络和核心企业的主导行为模式均为基于外部技术的创新模式。根据自回归分布滞后模型得出了网络自引专利数和网络内引用专利数所表征的行为对网络总专利数滞后效应。根据最小二乘法对三变量回归具有显著性,得出全产业链创新网络具有显著的融合创新行为模式的结论。

  14. Fuzzy Markov chains: uncertain probabilities

    OpenAIRE

    2002-01-01

    We consider finite Markov chains where there are uncertainties in some of the transition probabilities. These uncertainties are modeled by fuzzy numbers. Using a restricted fuzzy matrix multiplication we investigate the properties of regular, and absorbing, fuzzy Markov chains and show that the basic properties of these classical Markov chains generalize to fuzzy Markov chains.

  15. Essentials of supply chain management

    CERN Document Server

    Hugos, Michael H

    2011-01-01

    The latest thinking, strategies, developments, and technologies to stay current in supply chain management Presenting the core concepts and techniques of supply chain management in a clear, concise and easily readable style, the Third Edition of Essentials of Supply Chain Management outlines the most crucial tenets and concepts of supply chain management.

  16. Supply-Chain Optimization Template

    Science.gov (United States)

    Quiett, William F.; Sealing, Scott L.

    2009-01-01

    The Supply-Chain Optimization Template (SCOT) is an instructional guide for identifying, evaluating, and optimizing (including re-engineering) aerospace- oriented supply chains. The SCOT was derived from the Supply Chain Council s Supply-Chain Operations Reference (SCC SCOR) Model, which is more generic and more oriented toward achieving a competitive advantage in business.

  17. METRODOS: Meteorological preprocessor chain

    DEFF Research Database (Denmark)

    Astrup, P.; Mikkelsen, T.; Deme, S.

    2001-01-01

    The METRODOS meteorological preprocessor chain combines measured tower data and coarse grid numerical weather prediction (NWP) data with local scale flow models and similarity scaling to give high resolution approximations of the meteorological situation. Based on available wind velocity...... - heat flux related measurement, e.g. a temperature gradient, are used to give local values of friction velocity and Monin-Obukhov length plus an estimate of the mixing height. The METRODOS meteorological preprocessor chain is an integral part of the RODOS - Real Time On Line Decision Support - program...

  18. Modelling the coal chain

    Energy Technology Data Exchange (ETDEWEB)

    Gertenbach, J.-D.; Varendorff, R. von [Knowledge Based Engineering, Sandton (South Africa)

    1999-03-01

    Managing the supply chain in an integrated coal operation involves many operation and control options often too complex for the human mind to comprehend and react to. By integrating all the knowledge of a supply chain into an expert system, both off-line and on-line real time decisions are possible. Knowledge Based Engineering based in South Africa, has gained valuable experience in modelling such mining operations. The article discusses the methodologies that the company has implemented. KBE uses Gensym`s G2 Real Time Expert System as the foundation of the system and the knowledge base is developed modularly.

  19. Integrated supply chain risk management

    Directory of Open Access Journals (Sweden)

    Riaan Bredell

    2007-11-01

    Full Text Available Integrated supply chain risk management (ISCRM has become indispensable to the theory and practice of supply chain management. The economic and political realities of the modern world require not only a different approach to supply chain management, but also bold steps to secure supply chain performance and sustainable wealth creation. Integrated supply chain risk management provides supply chain organisations with a level of insight into their supply chains yet to be achieved. If correctly applied, this process may optimise management decision-making and assist in the protection and enhancement of shareholder value.

  20. Independent sets in chain cacti

    OpenAIRE

    Sedlar, Jelena

    2011-01-01

    In this paper chain cacti are considered. First, for two specific classes of chain cacti (orto-chains and meta-chains of cycles with h vertices) the recurrence relation for independence polynomial is derived. That recurrence relation is then used in deriving explicit expressions for independence number and number of maximum independent sets for such chains. Also, the recurrence relation for total number of independent sets for such graphs is derived. Finaly, the proof is provided that orto-ch...

  1. Standard handbook of chains chains for power transmission and material handling

    CERN Document Server

    Chain Association, American

    2005-01-01

    A BRIEF HISTORY OF THE DEVELOPMENT OF CHAINEarly DevelopmentsCog ChainCast Detachable ChainCast Pintle ChainPrecision Roller ChainEngineering Steel ChainSilent ChainFlat-Top ChainTerminologyA CHAIN OVERVIEW: USES AND ADVANTAGESGeneralTypes of ChainScope of Chains CoveredStyles and Forms of ChainsStraight and Offset Link ChainsChains With and Without RollersUses of ChainStandard Chains and Their UsesThe Advantages of Chains in ApplicationsAdvantages of Roller Chains in DrivesAdvantages of Silent Chain Drives

  2. Development Value Chains meet Business Supply Chains : The concept of Global Value Chains unraveled

    NARCIS (Netherlands)

    S. Drost (Sarah); J.C.A.C. van Wijk (Jeroen); S. Vellema (Sietze)

    2011-01-01

    textabstractValue chain promotion is considered a key element of private sector development strategies and pro-poor growth. However, (value) chain concepts are rather complex and unclear. This paper unravels the concept of global value chains and studies the diversity of key value chain-related (sup

  3. Nodal-chain metals

    Science.gov (United States)

    Bzdušek, Tomáš; Wu, Quansheng; Rüegg, Andreas; Sigrist, Manfred; Soluyanov, Alexey A.

    2016-10-01

    The band theory of solids is arguably the most successful theory of condensed-matter physics, providing a description of the electronic energy levels in various materials. Electronic wavefunctions obtained from the band theory enable a topological characterization of metals for which the electronic spectrum may host robust, topologically protected, fermionic quasiparticles. Many of these quasiparticles are analogues of the elementary particles of the Standard Model, but others do not have a counterpart in relativistic high-energy theories. A complete list of possible quasiparticles in solids is lacking, even in the non-interacting case. Here we describe the possible existence of a hitherto unrecognized type of fermionic excitation in metals. This excitation forms a nodal chain—a chain of connected loops in momentum space—along which conduction and valence bands touch. We prove that the nodal chain is topologically distinct from previously reported excitations. We discuss the symmetry requirements for the appearance of this excitation and predict that it is realized in an existing material, iridium tetrafluoride (IrF4), as well as in other compounds of this class of materials. Using IrF4 as an example, we provide a discussion of the topological surface states associated with the nodal chain. We argue that the presence of the nodal-chain fermions will result in anomalous magnetotransport properties, distinct from those of materials exhibiting previously known excitations.

  4. CHAINE DES ROTISSEUR @ HILTON

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The annual gala dinner of Chaine des Rotisseurs was hosted by Hilton Beijing. The “Ballet Dinner” - a great creation for both art and fine dining lovers was taken place in varies places within the hotel, including hotel lobby, 3rd floor and lobby lounge.

  5. Exploration Supply Chain Simulation

    Science.gov (United States)

    2008-01-01

    The Exploration Supply Chain Simulation project was chartered by the NASA Exploration Systems Mission Directorate to develop a software tool, with proper data, to quantitatively analyze supply chains for future program planning. This tool is a discrete-event simulation that uses the basic supply chain concepts of planning, sourcing, making, delivering, and returning. This supply chain perspective is combined with other discrete or continuous simulation factors. Discrete resource events (such as launch or delivery reviews) are represented as organizational functional units. Continuous resources (such as civil service or contractor program functions) are defined as enabling functional units. Concepts of fixed and variable costs are included in the model to allow the discrete events to interact with cost calculations. The definition file is intrinsic to the model, but a blank start can be initiated at any time. The current definition file is an Orion Ares I crew launch vehicle. Parameters stretch from Kennedy Space Center across and into other program entities (Michaud Assembly Facility, Aliant Techsystems, Stennis Space Center, Johnson Space Center, etc.) though these will only gain detail as the file continues to evolve. The Orion Ares I file definition in the tool continues to evolve, and analysis from this tool is expected in 2008. This is the first application of such business-driven modeling to a NASA/government-- aerospace contractor endeavor.

  6. Innovation in Supply Chains

    DEFF Research Database (Denmark)

    Maier, Maximilian; Korbel, Jakob; Brem, Alexander

    2015-01-01

    . Moreover, along with the fourth industrial revolution – industry 4.0 – new technologies such as cyber physical systems are fast gaining popularity. Hence, based on the analysis of relevant literature, we further develop the supply chain committee model, developed by Kaluza et al. (2003) to demonstrate how...

  7. Supply chain reliability modelling

    Directory of Open Access Journals (Sweden)

    Eugen Zaitsev

    2012-03-01

    Full Text Available Background: Today it is virtually impossible to operate alone on the international level in the logistics business. This promotes the establishment and development of new integrated business entities - logistic operators. However, such cooperation within a supply chain creates also many problems related to the supply chain reliability as well as the optimization of the supplies planning. The aim of this paper was to develop and formulate the mathematical model and algorithms to find the optimum plan of supplies by using economic criterion and the model for the probability evaluating of non-failure operation of supply chain. Methods: The mathematical model and algorithms to find the optimum plan of supplies were developed and formulated by using economic criterion and the model for the probability evaluating of non-failure operation of supply chain. Results and conclusions: The problem of ensuring failure-free performance of goods supply channel analyzed in the paper is characteristic of distributed network systems that make active use of business process outsourcing technologies. The complex planning problem occurring in such systems that requires taking into account the consumer's requirements for failure-free performance in terms of supply volumes and correctness can be reduced to a relatively simple linear programming problem through logical analysis of the structures. The sequence of the operations, which should be taken into account during the process of the supply planning with the supplier's functional reliability, was presented.

  8. Study on Global Value Chain Governance,Knowledge Transfer and Subcontracting Business Upgrading:Taking the Pearl River Delta as an Example%全球价值链治理、知识转移与代工企业升级——以珠三角地区为例

    Institute of Scientific and Technical Information of China (English)

    赖磊

    2012-01-01

    代工企业在全球价值链的升级具有战略性和紧迫性,其升级并不是独立自发的,而是受到了全球价值链中各经济主体之间的组织形式和关系安排的统一约束。知识经济的发展也为代工企业的升级创造了新的机遇。全球价值链、知识转移以及代工企业的升级之间存在着密切的关系,文章通过分析全球价值链治理下的全球领先企业与代工企业之间的知识转移模型,从而提出代工企业的升级建议。%The upgrading of subcontracting business in global value chain (GVC) is both strategic and emergent, but is neither independent nor spontaneous, which is restrained by the organizational form and relationship arrangement among economic bodies in GVC. The development of knowledge economy has also created a new opportunity for the upgrading of subcontracting business. The paper analyzes the model of knowledge transfer between the global leading business and the subcontracting business under the GVC governance, and proposes some suggestions for the upgrading of subcontracting business.

  9. An RFID middleware for supply chain management

    Directory of Open Access Journals (Sweden)

    Artur Pinto Carneiro

    2011-12-01

    Full Text Available RFID (Radio Frequency Identification systems for identification and tracking of products and equipments have been progressively adopted as an essential tool for supply chain management, a production environment where the members usually share with each other their own logistic and management systems. Therefore, the development of supply chain RFID systems can be strongly simplified through the inclusion of an intermediate software layer – the middleware – responsible for the creation of interfaces to integrate all the heterogeneous software components. In this article we present a case study developed at IPT (Instituto de Pesquisas Tecnológicas do Estado de São Paulo which gave rise to a middleware prototype able to implement the required software integration on the supply chain of an electric power distribution company. The developed middleware is used to manage the interactions with a heterogeneous group of mobile devices  cell phones, handhelds and data colectors,  operated by different supply chain agents that grab data associated to various processes executed by a given electric power distribution equipment during its life cycle and transfer those data to a central database in order to share them with all the logistic and management corporation systems.

  10. Intermuscular force transmission along myofascial chains: a systematic review.

    Science.gov (United States)

    Krause, Frieder; Wilke, Jan; Vogt, Lutz; Banzer, Winfried

    2016-06-01

    The present review aims to provide a systematic overview on tensile transmission along myofascial chains based on anatomical dissection studies and in vivo experiments. Evidence for the existence of myofascial chains is growing, and the capability of force transmission via myofascial chains has been hypothesized. However, there is still a lack of evidence concerning the functional significance and capability for force transfer. A systematic literature research was conducted using MEDLINE (Pubmed), ScienceDirect and Google Scholar. Studied myofascial chains encompassed the superficial backline (SBL), the back functional line (BFL) and the front functional line (FFL). Peer-reviewed human dissection studies as well as in vivo experiments reporting intermuscular tension transfer between the constituents of a myofascial chain were included. To assess methodic quality, two independent investigators rated studies by means of validated assessment tools (QUACS and PEDro Scale). The literature research identified 1022 articles. Nine studies (moderate to excellent methodological quality) were included. Concerning the SBL and the BFL, there is moderate evidence for force transfer at all three transitions (based on six studies), and one of two transitions (three studies). One study yields moderate evidence for a slight, but not significant force transfer at one transition in the FFL. The findings of the present study indicate that tension can be transferred between some of the examined adjacent structures. Force transfer might have an impact in overuse conditions as well as on sports performance. However, different methods of force application and measurement hinder the comparability of results. Considering anatomical variations in the degree of continuity and histological differences of the linking structures is crucial for interpretation. Future studies should focus on the in vivo function of myofascial continuity during isolated active or passive tissue tensioning.

  11. Putative respiratory chain of Porphyromonas gingivalis.

    Science.gov (United States)

    Meuric, Vincent; Rouillon, Astrid; Chandad, Fatiha; Bonnaure-Mallet, Martine

    2010-05-01

    The electron transfer chain in Porphyromonas gingivalis, or periodontopathogens, has not yet been characterized. P. gingivalis, a strict anaerobic bacteria and the second colonizer of the oral cavity, is considered to be a major causal agent involved in periodontal diseases. Primary colonizers create a favorable environment for P. gingivalis growth by decreasing oxygen pressure. Oxygen does not appear to be the final electron acceptor of the respiratory chain. Fumarate and cytochrome b have been implicated as major components of the respiratory activity. However, the P. gingivalis genome shows many other enzymes that could be implicated in aerobic or nitrite respiration. Using bioinformatic tools and literature studies of respiratory pathways, the ATP synthesis mechanism from the sodium cycle and nutrients metabolism, the putative respirasome of P. gingivalis has been proposed.

  12. moisture transfer

    Directory of Open Access Journals (Sweden)

    Don Kulasiri

    2005-01-01

    model drying porous materials. Coupled partial differential equations governing the moisture and heat transfer can be solved using numerical techniques, and in this paper we solve them analytically in a setting suitable for industrial drying situations. We discuss the nature of the solutions using the physical properties of Pinus radiata. It is shown that the temperature gradients play a significant role in deciding the moisture profiles within the material when thickness is large and that models based only on moisture potential gradients may not be sufficient to explain the drying phenomena in moist porous materials.

  13. Heat transfer

    CERN Document Server

    Jorge, Kubie; Thomas, Grassie

    2012-01-01

    A core task of engineers is to analyse energy related problems. The analytical treatment is usually based on principles of thermodynamics, fluid mechanics and heat transfer, but is increasingly being handled computationally.This unique resource presents a practical textbook, written for both undergraduates and professionals, with a series of over 60 computer workbooks on an accompanying CD.The book emphasizes how complex problems can be deconstructed into a series of simple steps. All thermophysical property computations are illustrated using diagrams within text and on the compani

  14. The design of supply chains

    DEFF Research Database (Denmark)

    Bøge Sørensen, Lars

    2004-01-01

    Keywords Supply Chain Management, Supply Chain Design, Literature studyAbstract Argues stability is a design objective for supply chain design alongside cost, leadtime and responsiveness. Performs an extensive literature study on supply chain design,identifies methods, theories and objectives...... in the existing literature. Describes the conceptexternal specificity and how it's used to design supply chains. Using the concept upstream,archetypes of risk minimal and maximal design are identified. Downstream the conceptdescribes two viable scenarios, one minimizing the impact, the other minimizing...... theprobability of (intended) departure of a supply chain partner. Finally, principles for supplychain design are described and managerial outlined....

  15. Decision-Making for Supply Chain Integration Supply Chain Integration

    CERN Document Server

    Lettice, Fiona; Durowoju, Olatunde

    2012-01-01

    Effective supply chain integration, and the tight co-ordination it creates, is an essential pre-requisite for successful supply chain management.  Decision-Making for Supply Chain Integration is a practical reference on recent research in the area of supply chain integration focusing on distributed decision-making problems. Recent applications of various decision-making tools for integrating supply chains are covered including chapters focusing on: •Supplier selection, pricing strategy and inventory decisions in multi-level supply chains, •RFID-enabled distributed decision-making, •Operational risk issues and time-critical decision-making for sensitive logistics nodes, Modelling end to end processes to improve supply chain integration, and •Integrated systems to improve service delivery and optimize resource use. Decision-Making for Supply Chain Integration provides an insight into the tools and methodologies of this field with support from real-life case studies demonstrating successful application ...

  16. Perfluorooctane sulphonate (PFOS) throughout the food production chain

    NARCIS (Netherlands)

    Asselt, van E.D.; Rietra, R.P.J.J.; Romkens, P.F.A.M.; Fels-Klerx, van der H.J.

    2011-01-01

    Perfluorooctane sulphonate (PFOS) is a persistent organic pollutant with adverse effects on human health. Since dietary intake plays an important role in human exposure, the transfer of PFOS throughout the food chain needs further investigation. The aim of this paper is to give an overview of PFOS c

  17. Towards Intelligent Supply Chains

    DEFF Research Database (Denmark)

    Siurdyban, Artur; Møller, Charles

    2012-01-01

    applied to the context of organizational processes can increase the success rate of business operations. The framework is created using a set of theoretical based constructs grounded in a discussion across several streams of research including psychology, pedagogy, artificial intelligence, learning...... of deploying inapt operations leading to deterioration of profits. To address this problem, we propose a unified business process design framework based on the paradigm of intelligence. Intelligence allows humans and human-designed systems cope with environmental volatility, and we argue that its principles......, business process management and supply chain management. It outlines a number of system tasks combined in four integrated management perspectives: build, execute, grow and innovate, put forward as business process design propositions for Intelligent Supply Chains....

  18. Perioperative supply chain management.

    Science.gov (United States)

    Feistritzer, N R; Keck, B R

    2000-09-01

    Faced with declining revenues and increasing operating expenses, hospitals are evaluating numerous mechanisms designed to reduce costs while simultaneously maintaining quality care. Many facilities have targeted initial cost reduction efforts in the reduction of labor expenses. Once labor expenses have been "right sized," facilities have continued to focus on service delivery improvements by the optimization of the "supply chain" process. This report presents a case study of the efforts of Vanderbilt University Medical Center in the redesign of its supply chain management process in the department of Perioperative Services. Utilizing a multidisciplinary project management structure, 3 work teams were established to complete the redesign process. To date, the project has reduced costs by $2.3 million and enhanced quality patient care by enhancing the delivery of appropriate clinical supplies during the perioperative experience.

  19. Volumes of chain links

    CERN Document Server

    Kaiser, James; Rollins, Clint

    2011-01-01

    Agol has conjectured that minimally twisted n-chain links are the smallest volume hyperbolic manifolds with n cusps, for n at most 10. In his thesis, Venzke mentions that these cannot be smallest volume for n at least 11, but does not provide a proof. In this paper, we give a proof of Venzke's statement. The proof for n at least 60 is completely rigorous. The proof for n between 11 and 59 uses a computer calculation, and can be made rigorous for manifolds of small enough complexity, using methods of Moser and Milley. Finally, we prove that the n-chain link with 2m or 2m+1 half-twists cannot be the minimal volume hyperbolic manifold with n cusps, provided n is at least 60 or |m| is at least 8, and we give computational data indicating this remains true for smaller n and |m|.

  20. The innovation value chain.

    Science.gov (United States)

    Hansen, Morten T; Birkinshaw, Julian

    2007-06-01

    The challenges of coming up with fresh ideas and realizing profits from them are different for every company. One firm may excel at finding good ideas but may have weak systems for bringing them to market. Another organization may have a terrific process for funding and rolling out new products and services but a shortage of concepts to develop. In this article, Hansen and Birkinshaw caution executives against using the latest and greatest innovation approaches and tools without understanding the unique deficiencies in their companies' innovation systems. They offer a framework for evaluating innovation performance: the innovation value chain. It comprises the three main phases of innovation (idea generation, conversion, and diffusion) as well as the critical activities performed during those phases (looking for ideas inside your unit; looking for them in other units; looking for them externally; selecting ideas; funding them; and promoting and spreading ideas companywide). Using this framework, managers get an end-to-end view of their innovation efforts. They can pinpoint their weakest links and tailor innovation best practices appropriately to strengthen those links. Companies typically succumb to one of three broad "weakest-link" scenarios. They are idea poor, conversion poor, or diffusion poor. The article looks at the ways smart companies - including Intuit, P&G, Sara Lee, Shell, and Siemens- modify the best innovation practices and apply them to address those organizations' individual needs and flaws. The authors warn that adopting the chain-based view of innovation requires new measures of what can be delivered by each link in the chain. The approach also entails new roles for employees "external scouts" and "internal evangelists," for example. Indeed, in their search for new hires, companies should seek out those candidates who can help address particular weaknesses in the innovation value chain.

  1. Monitoring Global Supply Chains

    OpenAIRE

    2014-01-01

    Firms reliant on supply chains to manufacture their goods risk reputational harm if the working conditions in those factories are revealed to be dangerous, illegal, or otherwise problematic. While firms are increasingly relying on private-sector "social auditors" to assess factory conditions, little had been known about the accuracy of those assessments. We analyzed nearly 17,000 code-of-conduct audits conducted at nearly 6,000 suppliers around the world. We found that audits yield fewer viol...

  2. Port supply chain integration : analyzing biofuel supply chains

    NARCIS (Netherlands)

    Stevens, Leonie C. E.; Vis, Iris F. A.

    2016-01-01

    This paper focuses on port supply chain integration to strengthen operational and business performance. We provide a structured and comprehensive method to enable port supply chain integration and demonstrate its applicability to the biofuel supply chain. We define the value proposition, role, activ

  3. Excitation energy transfer in the photosystem I

    Energy Technology Data Exchange (ETDEWEB)

    Webber, Andrew N

    2012-09-25

    Photosystem I is a multimeric pigment protein complex in plants, green alage and cyanobacteria that functions in series with Photosystem II to use light energy to oxidize water and reduce carbon dioxide. The Photosystem I core complex contains 96 chlorophyll a molecules and 22 carotenoids that are involved in light harvesting and electron transfer. In eucaryotes, PSI also has a peripheral light harvesting complex I (LHCI). The role of specific chlorophylls in excitation and electron transfer are still unresolved. In particular, the role of so-called bridging chlorophylls, located between the bulk antenna and the core electron transfer chain, in the transfer of excitation energy to the reaction center are unknown. During the past funding period, site directed mutagenesis has been used to create mutants that effect the physical properties of these key chlorophylls, and to explore how this alters the function of the photosystem. Studying these mutants using ultrafast absorption spectroscopy has led to a better understanding of the process by which excitation energy is transferred from the antenna chlorophylls to the electron transfer chain chlorophylls, and what the role of connecting chlorophylls and A_0 chlorophylls is in this process. We have also used these mutants to investigate whch of the central group of six chlorophylls are involved in the primary steps of charge separation and electron transfer.

  4. Exact solution of the $D_3$ non-Abelian anyon chain

    CERN Document Server

    Braylovskaya, Natalia; Frahm, Holger

    2016-01-01

    Commuting transfer matrices for linear chains of interacting non-Abelian anyons from the two-dimensional irreducible representation of the dihedral group $D_3$ (or, equivalently, the integer sector of the $su(2)_4$ spin-$1$ chain) are constructed using the spin-anyon correspondence to a $D_3$-symmetric formulation of the XXZ Heisenberg spin chain. The spectral problem is solved using discrete inversion identities satisfied by these transfer matrices and functional Bethe ansatz methods. The resulting spectrum can be related to that of the XXZ spin-$1/2$ Heisenberg chain with boundary conditions depending on the topological sector of the anyon chain. The properties of this model in the critical regime are studied by finite size analysis of the spectrum. In particular, points in the phase diagram where the anyon chain realizes some of the rational $\\mathbb{Z}_2$ orbifold theories are identified.

  5. Exact solution of the D3 non-Abelian anyon chain

    Science.gov (United States)

    Braylovskaya, Natalia; Finch, Peter E.; Frahm, Holger

    2016-08-01

    Commuting transfer matrices for linear chains of interacting non-Abelian anyons from the two-dimensional irreducible representation of the dihedral group D3 [or, equivalently, the integer sector of the s u (2) 4 spin-1 chain] are constructed using the spin-anyon correspondence to a D3-symmetric formulation of the XXZ Heisenberg spin chain. The spectral problem is solved using discrete inversion identities satisfied by these transfer matrices and functional Bethe ansatz methods. The resulting spectrum can be related to that of the XXZ spin-1/2 Heisenberg chain with boundary conditions depending on the topological sector of the anyon chain. The properties of this model in the critical regime are studied by finite size analysis of the spectrum. In particular, points in the phase diagram where the anyon chain realizes some of the rational Z2 orbifold theories are identified.

  6. Ernst Chain: a great man of science.

    Science.gov (United States)

    Kardos, Nelson; Demain, Arnold L

    2013-08-01

    This paper is a tribute to the scientific accomplishments of Ernst Chain and the influence he exerted over the fields of industrial microbiology and biotechnology. Chain is the father of the modern antibiotic era and all the benefits that these therapeutic agents have brought, i.e., longer life spans, greater levels of public health, widespread modern surgery, and control of debilitating infectious diseases, including tuberculosis, gonorrhea, syphilis, etc. Penicillin was the first antibiotic to become commercially available, and its use ushered in the age of antibiotics. The discovery of penicillin's bactericidal action had been made by Alexander Fleming in London in 1928. After publishing his observations in 1929, no further progress was made until the work was picked up in 1939 by scientists at Oxford University. The group was headed by Howard Florey, and Chain was the group's lead scientist. Chain was born and educated in Germany, and he fled in 1933 as a Jewish refugee from Nazism to England. Other important members of the Oxford research team were Norman Heatley and Edward Abraham. The team was able to produce and isolate penicillin under conditions of scarce resources and many technical challenges. Sufficient material was collected and tested on mice to successfully demonstrate penicillin's bactericidal action on pathogens, while being nontoxic to mammals. Chain directed the microbiological methods for producing penicillin and the chemical engineering methods to extract the material. This technology was transferred to US government facilities in 1941 for commercial production of penicillin, becoming an important element in the Allied war effort. In 1945, the Nobel Prize for medicine was shared by Fleming, Florey, and Chain in recognition of their work in developing penicillin as a therapeutic agent. After World War II, Chain tried to persuade the British government to fund a new national antibiotic industry with both research and production facilities. As

  7. Adjustable chain trees for proteins

    DEFF Research Database (Denmark)

    Winter, Pawel; Fonseca, Rasmus

    2012-01-01

    A chain tree is a data structure for changing protein conformations. It enables very fast detection of clashes and free energy potential calculations. A modified version of chain trees that adjust themselves to the changing conformations of folding proteins is introduced. This results in much...... tighter bounding volume hierarchies and therefore fewer intersection checks. Computational results indicate that the efficiency of the adjustable chain trees is significantly improved compared to the traditional chain trees....

  8. Supply chain dynamics in Asia

    OpenAIRE

    Banomyong, Ruth

    2010-01-01

    Supply chain management in Asia is a relatively novel topic but a key challenge for all Asian based manufacturers and traders when trying to integrate into the "global market". The purpose of the paper is to describe key supply chain issues faced in Asia. These issues are related to supply chain security that forces Asian firms to comply with numerous requirements as well as the importance of a properly managed supply chain in enhancing firms' competitiveness. The critical role played by Asia...

  9. Targeting gene transfer to ovarian epithelial carcinoma cells with lentivirus displaying single-chain antibody%单链抗体导向卵巢上皮癌进行靶向基因 转移的实验研究

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective:To investigate the targeting gene transfer of Anti-MUC-1(ScFv) directed lentivirus to MUC-1+ ovarian epithelial carcinoma cells.Methods:MUC-1 single-chain antibody gene constructed in the plasmid pM.TC.G were transferred to packaging cell line 293T to produce anti-MUC-1-directed lentivirus using Ca3(PO4)2 precipitation method. Ovarian epithelial cancer cell line SKOV-3(MUC-1+) and normal human gingival fibroblast cell GF(MUC-1-)were co-cultured, then were infected by lentivirus. The infection result was observed through fluorescence microscopy. The competition assay that was the addition of the anti-MUC-1 single-chain antibody prior to lentivirus infection showed whether anti-MUC-1 Ab could inhibite infection. Results: After lentivirus infetion, cell SKOV-3 and GF which were co-cultured had remarkably different infection rate. The addition of the MUC-1 Ab prior to the lentivirus infection showed anti-MUC-1 Ab can inhibite infection.This competition assay showed that the infection is mediated by the antibody moiety and, therefore, is antibody specific. Conclusions:Anti-MUC-1(ScFv) directed lentivirus can targetingly transfer gene into MUC-1+ ovarian cancer cell line.%目的:探讨靶向性基因转移载体—含抗MUC-1单链抗体的慢病毒对MUC-1+卵巢上皮癌细胞系SKOV-3细胞进行基因转移的特异性,为卵巢上皮癌的靶向性基因治疗提供实验基础。方法:将针对SKOV-3细胞上抗原MUC-1的单链抗体基因构建到慢病毒包膜结构质粒(pM.TC.G),以报告基因绿色荧光蛋白(GFP)基因作为目的基因。用磷酸钙沉淀法进行Anti-MUC-1(ScFv)慢病毒包装,感染共培养的卵巢癌细胞SKOV-3(MUC-1+)和正常人成纤维细胞GF(MUC-1-),荧光显微镜下观察感染效果。竞争抑制实验即病毒感染前加入Anti-MUC-1单抗是否抑制病毒感染。结果:荧光显微镜下观察到Anti-MUC-1(ScFv)介导的慢病毒对共培养的SKOV-3(MUC-1+

  10. Coupled motions direct electrons along human microsomal P450 Chains.

    Directory of Open Access Journals (Sweden)

    Christopher R Pudney

    2011-12-01

    Full Text Available Protein domain motion is often implicated in biological electron transfer, but the general significance of motion is not clear. Motion has been implicated in the transfer of electrons from human cytochrome P450 reductase (CPR to all microsomal cytochrome P450s (CYPs. Our hypothesis is that tight coupling of motion with enzyme chemistry can signal "ready and waiting" states for electron transfer from CPR to downstream CYPs and support vectorial electron transfer across complex redox chains. We developed a novel approach to study the time-dependence of dynamical change during catalysis that reports on the changing conformational states of CPR. FRET was linked to stopped-flow studies of electron transfer in CPR that contains donor-acceptor fluorophores on the enzyme surface. Open and closed states of CPR were correlated with key steps in the catalytic cycle which demonstrated how redox chemistry and NADPH binding drive successive opening and closing of the enzyme. Specifically, we provide evidence that reduction of the flavin moieties in CPR induces CPR opening, whereas ligand binding induces CPR closing. A dynamic reaction cycle was created in which CPR optimizes internal electron transfer between flavin cofactors by adopting closed states and signals "ready and waiting" conformations to partner CYP enzymes by adopting more open states. This complex, temporal control of enzyme motion is used to catalyze directional electron transfer from NADPH→FAD→FMN→heme, thereby facilitating all microsomal P450-catalysed reactions. Motions critical to the broader biological functions of CPR are tightly coupled to enzyme chemistry in the human NADPH-CPR-CYP redox chain. That redox chemistry alone is sufficient to drive functionally necessary, large-scale conformational change is remarkable. Rather than relying on stochastic conformational sampling, our study highlights a need for tight coupling of motion to enzyme chemistry to give vectorial electron

  11. Requirements of supply chain management in differentiating European pork chains.

    Science.gov (United States)

    Trienekens, Jacques; Wognum, Nel

    2013-11-01

    This paper summarizes results obtained by research into pork chain management in the EU Integrated Project Q-Porkchains. Changing demands for intrinsic and extrinsic quality attributes of pork products impact the way supply chain management should be organized from the farmer down to the consumer. The paper shows the importance of Quality Management Systems for integrating supply chains and enhancing consumer confidence. The paper also presents innovations in information system integration for aligning information exchange in the supply chain and logistics concepts based on innovative measurement technologies at the slaughterhouse stage. In the final section research challenges towards sustainable pork supply chains satisfying current consumer demands are presented.

  12. On chains of centered valuations

    Directory of Open Access Journals (Sweden)

    Rachid Chibloun

    2003-01-01

    Full Text Available We study chains of centered valuations of a domain A and chains of centered valuations of A [X1,…,Xn] corresponding to valuations of A. Finally, we make some applications to chains of valuations centered on the same ideal of A [X1,…,Xn] and extending the same valuation of A.

  13. Designing structural supply chain flexibility

    NARCIS (Netherlands)

    Mulinski, Ksawery Jan

    2012-01-01

    In a continuously changing business environment the role of supply chain flexibility is constantly increasing. A flexible supply chain can ensure survival in quickly changing market conditions as well as enable sustainable growth. This thesis explores the topic of supply chain flexibility with focus

  14. Tidal and marine energy in the uk– identifying the future challenges for supply chain development

    OpenAIRE

    Thomas, Andrew; Mason-Jones, Rachel; Turner, David,; Davies, Paul; O’Doherty, Tim; O’Doherty, Daphne; Mason-Jones, Allan; Murphy, Lyndon

    2013-01-01

    The purpose of this paper is to investigate the current technical and operational supply chain issues surrounding the development of tidal and marine energy production in the UK. The paper outlines the market and growth potential of tidal energy production in the UK before identifying the key supply chain themes surrounding tidal energy production including an analysis of the portability and transferability of current supply chain thinking and development from other renewable energy systems s...

  15. Alkyl chains acting as entropy reservoir in liquid crystalline materials.

    Science.gov (United States)

    Sorai, Michio; Saito, Kazuya

    2003-01-01

    The roles played by the conformational disordering of alkyl chains in determining the aggregation states of matter are reviewed for liquid crystalline materials from a thermodynamic perspective. Entropy, which is one of the most macroscopic concepts but which has a clear microscopic meaning, provides crucial microscopic information for complex systems for which a microscopic description is hard to establish. Starting from structural implication by absolute (third-law) entropy for crystalline solids, the existence of successive phase transitions caused by the successive conformational melting of alkyl chains in discotic mesogens is explained. An experimental basis is given for the "quasi-binary picture" of thermotropic liquid crystals, i.e., the highly disordered alkyl chains behave like a second component (solvent). A novel entropy transfer between the "components" of a molecule and the resulting "alkyl chains as entropy reservoir" mechanism are explained for cubic mesogens.

  16. Evidence of rapid transfer and bioaccumulation of Microcystin-LR poses potential risk to freshwater prawn Macrobrachium rosenbergii (de Man)

    DEFF Research Database (Denmark)

    Liu, Liping; Su, Xiaoming; Chen, Taoying;

    2016-01-01

    Microcystins accumulate in aquatic organisms and can be transferred to higher trophic levels, eventually affecting vector animals and consumers. We examined three levels of an aquatic food chain (Microcystis aeruginosa, Daphnia magna and Macrobrachium rosenbergii) to identify the transfer efficie...

  17. Radiology's value chain.

    Science.gov (United States)

    Enzmann, Dieter R

    2012-04-01

    A diagnostic radiology value chain is constructed to define its main components, all of which are vulnerable to change, because digitization has caused disaggregation of the chain. Some components afford opportunities to improve productivity, some add value, while some face outsourcing to lower labor cost and to information technology substitutes, raising commoditization risks. Digital image information, because it can be competitive at smaller economies of scale, allows faster, differential rates of technological innovation of components, initiating a centralization-to-decentralization technology trend. Digitization, having triggered disaggregation of radiology's professional service model, may soon usher in an information business model. This means moving from a mind-set of "reading images" to an orientation of creating and organizing information for greater accuracy, faster speed, and lower cost in medical decision making. Information businesses view value chain investments differently than do small professional services. In the former model, producing a better business product will extend image interpretation beyond a radiologist's personal fund of knowledge to encompass expanding external imaging databases. A follow-on expansion with integration of image and molecular information into a report will offer new value in medical decision making. Improved interpretation plus new integration will enrich and diversify radiology's key service products, the report and consultation. A more robust, information-rich report derived from a "systems" and "computational" radiology approach will be facilitated by a transition from a professional service to an information business. Under health care reform, radiology will transition its emphasis from volume to greater value. Radiology's future brightens with the adoption of a philosophy of offering information rather than "reads" for decision making. Staunchly defending the status quo via turf wars is unlikely to constitute a

  18. Supply Chain Costing

    DEFF Research Database (Denmark)

    Asmussen, Jesper Normann; Kristensen, Jesper; Wæhrens, Brian Vejrum

    2016-01-01

    Based Costing (ABC) på et forsyningskædeniveau – heri benævnt Supply Chain Costing (SCC). Udoverdefordelederfindesved ABCtilføjerSCCogså et økonomisk grundlag til det strategiske rationale, der ofte ligger bag opbygningen af virksomhedens forsyningskæde, og kan dermed medvirke til konkret....... Virksomhedens evne til at udarbejde relevantinformation fremstår derfor som en vigtig parameter, såfremt virksomheden skal forblive konkurrencedygtig i en stadig mere kompleks verden, hvor udviklingen foregår stadig hurtigere. Denne arbejdsboggiverindsigtidemuligheder,der eksisterer ved at anvende Activity...

  19. Quantum state transfer via temporal kicking of information

    CERN Document Server

    Di Franco, C; Kim, M S

    2009-01-01

    We propose a strategy for perfect state transfer in spin chains based on the use of an unmodulated coupling Hamiltonian whose coefficients are explicitly time dependent. We show that, if specific and non-demanding conditions are satisfied by the temporal behavior of the coupling strengths, our model allows perfect state transfer. The paradigma put forward by our proposal holds the promises to set an alternative standard to the use of clever encoding and coupling-strength engineering for perfect state transfer.

  20. [Trophic chains in soil].

    Science.gov (United States)

    Goncharov, A A; Tiunov, A V

    2013-01-01

    Trophic links of soil animals are extensively diverse but also flexible. Moreover, feeding activity of large soil saprotrophs often cascades into a range of ecosystem-level consequences via the ecological engineering. Better knowledge on the main sources of energy utilized by soil animals is needed for understanding functional structure of soil animal communities and their participation in the global carbon cycling. Using published and original data, we consider the relative importance of dead organic matter and saprotrophic microorganisms as a basal energy source in the detritus-based food chains, the feeding of endogeic macrofauna on the stabilized soil organic matter, and the role of recent photosynthate in the energy budget of soil communities. Soil food webs are spatially and functionally compartmentalized, though the separation of food chains into bacteria- and fungi-based channels seems to be an over-simplification. The regulation of the litter decomposition rates via top-down trophic interactions across more than one trophic level is only partly supported by experimental data, but mobile litter-dwelling predators play a crucial role in integrating local food webs within and across neighboring ecosystems.

  1. Modeling Uncertainty of Directed Movement via Markov Chains

    Directory of Open Access Journals (Sweden)

    YIN Zhangcai

    2015-10-01

    Full Text Available Probabilistic time geography (PTG is suggested as an extension of (classical time geography, in order to present the uncertainty of an agent located at the accessible position by probability. This may provide a quantitative basis for most likely finding an agent at a location. In recent years, PTG based on normal distribution or Brown bridge has been proposed, its variance, however, is irrelevant with the agent's speed or divergent with the increase of the speed; so they are difficult to take into account application pertinence and stability. In this paper, a new method is proposed to model PTG based on Markov chain. Firstly, a bidirectional conditions Markov chain is modeled, the limit of which, when the moving speed is large enough, can be regarded as the Brown bridge, thus has the characteristics of digital stability. Then, the directed movement is mapped to Markov chains. The essential part is to build step length, the state space and transfer matrix of Markov chain according to the space and time position of directional movement, movement speed information, to make sure the Markov chain related to the movement speed. Finally, calculating continuously the probability distribution of the directed movement at any time by the Markov chains, it can be get the possibility of an agent located at the accessible position. Experimental results show that, the variance based on Markov chains not only is related to speed, but also is tending towards stability with increasing the agent's maximum speed.

  2. Multidimensional Structure for Definingthe Effect of Organizational Culture and Supply Chain Culture on Knowledge Sharing in Supply Chain of Automotive Industry: With Emphasis on Improving Supply Chain Performance

    Directory of Open Access Journals (Sweden)

    Mohsen Shafiei Nikabadi

    2012-12-01

    Full Text Available : One of the key aspects of knowledge management is organizational culture. Finding an appropriate culture and key indicators for culture in implementation and execution of knowledge management are one the most important matter in knowledge management implementation in any organization. So, the main purpose of this article was presenting a multidimensional structure for organizational culture and supply chain culture with the aim of effective knowledge sharing in supply chain of automotive industry of Iran. First, according to the literature review, key indicators for any dimension of multidimensional structure of the research were defined. Then, key indicators were revised, adjusted and modified by three industry experts and three college professors, so 4 questions and 5 hypotheses were offered. Next, that multidimensional structure has been assessed as a survey and cause-effect study in supply chains of Iran Khodro Company and Saipa Company.115 industry professionals have participated in this study. In the research, after testing co-linearity between variables, relations between different dimensions of the multidimensional structure have been assessed with the help of path analysis. Research findings showed that the multidimensional structure introduced in the study had an appropriate fitness in automotive industry. The results of path analysis also showed that the culture of the supply chain has had the greatest impact of Business culture. On the other hand, business culture had a strong but indirect effect on supply chain performance. And finally, the greatest effect of knowledge sharing and transferring was on non-financial performance of supply chain.

  3. Polyketide chain length control by chain length factor.

    Science.gov (United States)

    Tang, Yi; Tsai, Shiou-Chuan; Khosla, Chaitan

    2003-10-22

    Bacterial aromatic polyketides are pharmacologically important natural products. A critical parameter that dictates product structure is the carbon chain length of the polyketide backbone. Systematic manipulation of polyketide chain length represents a major unmet challenge in natural product biosynthesis. Polyketide chain elongation is catalyzed by a heterodimeric ketosynthase. In contrast to homodimeric ketosynthases found in fatty acid synthases, the active site cysteine is absent from the one subunit of this heterodimer. The precise role of this catalytically silent subunit has been debated over the past decade. We demonstrate here that this subunit is the primary determinant of polyketide chain length, thereby validating its designation as chain length factor. Using structure-based mutagenesis, we identified key residues in the chain length factor that could be manipulated to convert an octaketide synthase into a decaketide synthase and vice versa. These results should lead to novel strategies for the engineered biosynthesis of hitherto unidentified polyketide scaffolds.

  4. Information in the supply chain: measuring supply chain performance

    OpenAIRE

    Bytheway, Andrew

    1995-01-01

    Information is one of many factors in the development of supply chain operations. It is a key factor in a number of new initiatives, such as: business process management. partnership development, efficient customer response, tighter integration of supply chain operations and outsourcing of ancillary operations. Improvement of the supply chain takes place at different levels: simple efficiency (the Improvement of existing processes), improved quality of service (the redesign of ...

  5. Doping of Semiconducting Atomic Chains

    Science.gov (United States)

    Toshishige, Yamada; Kutler, Paul (Technical Monitor)

    1997-01-01

    Due to the rapid progress in atom manipulation technology, atomic chain electronics would not be a dream, where foreign atoms are placed on a substrate to form a chain, and its electronic properties are designed by controlling the lattice constant d. It has been shown theoretically that a Si atomic chain is metallic regardless of d and that a Mg atomic chain is semiconducting or insulating with a band gap modified with d. For electronic applications, it is essential to establish a method to dope a semiconducting chain, which is to control the Fermi energy position without altering the original band structure. If we replace some of the chain atoms with dopant atoms randomly, the electrons will see random potential along the chain and will be localized strongly in space (Anderson localization). However, if we replace periodically, although the electrons can spread over the chain, there will generally appear new bands and band gaps reflecting the new periodicity of dopant atoms. This will change the original band structure significantly. In order to overcome this dilemma, we may place a dopant atom beside the chain at every N lattice periods (N > 1). Because of the periodic arrangement of dopant atoms, we can avoid the unwanted Anderson localization. Moreover, since the dopant atoms do not constitute the chain, the overlap interaction between them is minimized, and the band structure modification can be made smallest. Some tight-binding results will be discussed to demonstrate the present idea.

  6. Dynamics of Polymer Chains.

    Science.gov (United States)

    Hong, Tzay-Ming

    A major objective of this research is to establish at a more fundamental level some of the qualitative or semi-quantitative treatments in use at the present time, such as the Doi-Edwards tube picture, the switch from non -ideal to ideal behavior, and dynamical aspects of the reptation model. The main topics are: (I) An attempt was made to determine the order of magnitude of the elastic time interval of a viscoelastic polymer melt, defining it as the reciprocal of the average rate at which the total entanglement (clockwise plus anticlockwise) passes through zero due to thermal agitation. We calculated the case of a free chain winding about a straight rod both in friction-independent regime and in high friction regime. (II) By successively coarse -graining and rescaling the monomer-monomer interaction (using a modified Wilson recursion formula) we found that the interaction is driven to a very strong but short-ranged one. This verifies the observation that polymers in dilute solutions tend to curl up and behave like hard spheres. (III) We studied the case of chemical equilibrium of i-mers with their nucleating monomers and on the basis of a Flory-Huggins -type mean field theory find that in the dilute limit the swelling of the i-mers takes on the traditional N ^{3over5} law only for sufficiently small monomer chemical potential. When that potential is large enough, then, assuming a Flory law of chain propagation, the law seems to become N^{1over3 }. This is distinct from the problem of changeover from dilute to semidilute polymer system, which we also studied by imposing total polymer density as a constraint equation. (IV) Another item examined concerns the form of the space curve that a very long polymer must assume in order to minimize its free energy (we found that a family of helices with a definite functional relation between pitch and radius renders the free energy stationary). Because a chain is a one-dimensional object, this does not mean that helical shapes

  7. Ergonomic evaluation of the wood cutting task using chain saw.

    Science.gov (United States)

    Raghav, Gaurav; Farooq, Mohd; Khan, Abid Ali; Muzammil, Mohammad

    2013-10-01

    Workers whose hands are regularly exposed to hand-arm vibration may suffer from damage to the tissues of the hands and arms, which cause the symptoms collectively known as hand-arm vibration syndrome. However, investigations have shown that vibration hazards can be controlled and risks might be reduced by good design of the task/tools. In the present study, an experiment was conducted for the evaluation of risk in operating chain saw. The evaluation of chain saw ergonomically performed based on four parameters--Discomfort level, EMG activity of seven different forearm muscles (ECRB, ECU, EPB, FCR, FDS, FCU and PT), angular deviation in hand-arm system and the vibration transfer to hand-arm system, while operating the chain saw on a wooden block. Ten male candidates participated for the discomfort level experiment, four participants volunteered for the EMG activity and angular deviation experiment and two participants were involved in vibration transfer recordings. The results showed that ECRB muscle was mostly affected muscle in this task of operating a chain saw. The findings also indicated that the problems were occurred due to the bad design of the rear handle of chain saw in association with the available vibration levels on hand arm system.

  8. Quivers via anomaly chains

    Energy Technology Data Exchange (ETDEWEB)

    Casero, Roberto [Dipartimento di Fisica, Universita di Milano-Bicocca, Piazza della Scienza, 3, 20126 Milan (Italy)]. E-mail: roberto.casero@mib.infn.it; Trincherini, Enrico [Dipartimento di Fisica, Universita di Milano-Bicocca, Piazza della Scienza, 3, 20126 Milan (Italy)

    2003-09-01

    We study quivers in the context of matrix models. We introduce chains of generalized Konishi anomalies to write the quadratic and cubic equations that constrain the resolvents of general affine A-circumflex{sub n-1} and non-affine A{sub n} quiver gauge theories, and give a procedure to calculate all higher-order relations. For these theories we also evaluate, as functions of the resolvents, VEV's of chiral operators with two and four bi-fundamental insertions. As an example of the general procedure we explicitly consider the two simplest quivers A{sub 2} and A-circumflex{sub 1}, obtaining in the first case a cubic algebraic curve, and for the affine theory the same equation as that of U(N) theories with adjoint matter, successfully reproducing the RG cascade result. (author)

  9. Quivers via anomaly chains

    CERN Document Server

    Casero, R; Casero, Roberto; Trincherini, Enrico

    2003-01-01

    We study quivers in the context of matrix models. We introduce chains of generalized Konishi anomalies to write the quadratic and cubic equations that constrain the resolvents of general affine and non-affine quiver gauge theories, and give a procedure to calculate all higher-order relations. For these theories we also evaluate, as functions of the resolvents, VEV's of chiral operators with two and four bifundamental insertions. As an example of the general procedure we explicitly consider the two simplest quivers A2 and A1(affine), obtaining in the first case a cubic algebraic curve, and for the affine theory the same equation as that of U(N) theories with adjoint matter, successfully reproducing the RG cascade result.

  10. NNSA TRITIUM SUPPLY CHAIN

    Energy Technology Data Exchange (ETDEWEB)

    Wyrick, Steven [Savannah River National Laboratory, Aiken, SC, USA; Cordaro, Joseph [Savannah River National Laboratory, Aiken, SC, USA; Founds, Nanette [National Nuclear Security Administration, Albuquerque, NM, USA; Chambellan, Curtis [National Nuclear Security Administration, Albuquerque, NM, USA

    2013-08-21

    Savannah River Site plays a critical role in the Tritium Production Supply Chain for the National Nuclear Security Administration (NNSA). The entire process includes: • Production of Tritium Producing Burnable Absorber Rods (TPBARs) at the Westinghouse WesDyne Nuclear Fuels Plant in Columbia, South Carolina • Production of unobligated Low Enriched Uranium (LEU) at the United States Enrichment Corporation (USEC) in Portsmouth, Ohio • Irradiation of TPBARs with the LEU at the Tennessee Valley Authority (TVA) Watts Bar Reactor • Extraction of tritium from the irradiated TPBARs at the Tritium Extraction Facility (TEF) at Savannah River Site • Processing the tritium at the Savannah River Site, which includes removal of nonhydrogen species and separation of the hydrogen isotopes of protium, deuterium and tritium.

  11. PHONONS IN POLYACENIC CHAINS

    Institute of Scientific and Technical Information of China (English)

    O. Rafil; M. Tamine; B. Bourahla; R. Tigrine; S. Amoudache; A. Khater

    2006-01-01

    We have theoretically resolved phonon excitations in quasi-two-dimensional organic crystals of polyacenic semiconductor material which may be obtained by the pyrolytic treatment of phenol-formaldehyde resin. A model for studying the dynamical properties using three polyacene chains is proposed with the aim to present the vibrational properties of this structure. It employs the formalism of solid states in two dimensions which admit phonons. A simulation process of the two-dimensional lattice structure shows that elastic waves may explain the existence of vibrational modes in the frequency range 100-400 cm-1. The presence of acoustic and optical like phonons is discussed in terms of the elastic force constants. A hyperfine resonance structure is obtained. It allows the analysis of the dynamical evolution in thin films of polyacene. It is found that the behavior of the phonon density of states exhibits resonance between modes in the structure.

  12. Quench Dynamics of Two Coupled Ionic Zig-Zag Chains

    CERN Document Server

    Klumpp, Andrea; Schmelcher, Peter

    2015-01-01

    We explore the nonequilibrium dynamics of two coupled zig-zag chains of trapped ions in a double well potential. Following a quench of the potential barrier between both wells, the induced coupling between both chains due to the long-range interaction of the ions leads to their complete melting. The resulting dynamics is however not exlusively irregular but leads to phases of motion during which quasistationary structures appear with the ions arranged in a plethora of ordered and symmetric configurations. A normal mode analysis shows that distinguished modes lead to the decisive population transfer responsible for this sequence of regular and irregular structures.

  13. Transfer mechanism of temoporfin between liposomal membranes.

    Science.gov (United States)

    Hefesha, Hossam; Loew, Stephan; Liu, Xiangli; May, Sylvio; Fahr, Alfred

    2011-03-30

    The transfer kinetics of temoporfin, a classic photosensitizer, was analyzed by investigating the influence of total lipid content, temperature, as well as charge, acyl chain length, and saturation of the lipids in donor vesicles using a mini ion exchange column technique. The obtained results are consistent with an apparent first order kinetics in which the transfer proceeds through both liposome collisions and through the aqueous phase. We present a corresponding theoretical model that accounts for the detailed distribution of drug molecules in donor and acceptor liposomes and predicts the transfer rates as a function of drug concentration and number of donor and acceptor liposomes. The experimentally observed transfer rates depended strongly on the temperature and comply with the Arrhenius equation. Thermodynamic calculations indicate the transfer process to be entropically controlled. In terms of the charge of donor liposomes, positively charged liposomes showed transfer rates faster than negatively charged liposomes whereas the maximum amount transferred was almost the same. A more rigid structure of the donor liposomes increases the transfer rate of temoporfin, which is caused by expelling the drug from the membrane interior, as proposed in former work. In summary, our combined theoretical/experimental approach offers a systematic way to study the mechanism of drug release from liposome-based delivery systems.

  14. Chains, bombs, potrzebies and slugs

    Science.gov (United States)

    Jewess, Mike; McDowell, Alex; Maxfield, Stephen; Hunt, A. G.; Hicks, Bruce

    2010-03-01

    I read with pleasure Robert Crease's article on unusual units (February pp17-19). However, the article stated that an acre is 10×10 chains, when it is in fact 10×1 chains. Incidentally, a distance of 10 chains (220 yards) is known as a furlong, a word that suggests the length of a ploughed furrow and that is still used in horse-racing.

  15. Synthesis of π-conjugated polymers containing aminoquinoline-borafluorene complexes in the main-chain.

    Science.gov (United States)

    Tokoro, Yuichiro; Nagai, Atsushi; Tanaka, Kazuo; Chujo, Yoshiki

    2012-04-13

    The regulation of electron transfer between a conjugated polymer and ligands orthogonally connected to the main-chain is reported. Poly(arylene-ethynylene)s containing aminoquinoline-borafluorene complexes in the main-chain are synthesized in good yields by a Sonogashira-Hagihara coupling. Single crystal X-ray analysis of a model compound has elucidated the complex's structure in which the aminoquinolate moiety and the borafluorene ring are connected directly and orthogonally. Moreover, the optical properties of the polymers are characterized by UV-vis absorption and photoluminescence spectra. Perfluorinated alkyl chain-containing polymers show strong emission, while hydrocarbon chain-containing ones exhibit only a slight emission. DFT calculation suggests that an electron transfer from the excited main-chain to the aminoquinolate ligand is suppressed because of the lowered LUMO level by introducing the electron withdrawing groups, resulting in the significant emission.

  16. DOS cones along atomic chains

    Science.gov (United States)

    Kwapiński, Tomasz

    2017-03-01

    The electron transport properties of a linear atomic chain are studied theoretically within the tight-binding Hamiltonian and the Green’s function method. Variations of the local density of states (DOS) along the chain are investigated. They are crucial in scanning tunnelling experiments and give important insight into the electron transport mechanism and charge distribution inside chains. It is found that depending on the chain parity the local DOS at the Fermi level can form cone-like structures (DOS cones) along the chain. The general condition for the local DOS oscillations is obtained and the linear behaviour of the local density function is confirmed analytically. DOS cones are characterized by a linear decay towards the chain which is in contrast to the propagation properties of charge density waves, end states and Friedel oscillations in one-dimensional systems. We find that DOS cones can appear due to non-resonant electron transport, the spin–orbit scattering or for chains fabricated on a substrate with localized electrons. It is also shown that for imperfect chains (e.g. with a reduced coupling strength between two neighboring sites) a diamond-like structure of the local DOS along the chain appears.

  17. Risikobasiertes Supply-Chain-Management

    DEFF Research Database (Denmark)

    Wieland, Andreas; Schinz, Philipp

    2015-01-01

    Das Management erlebt seit einigen Jahren dahingehend einen Paradigmenwechsel, dass nicht mehr Unternehmen als einzelne autonome Einheiten im Wettbewerb zueinander stehen, sondern die Supply Chains, in denen diese Unternehmen eingebunden sind. Ursachen hierfür sind beispielsweise die Auslagerung...... von Nicht-Kernprozessen auf vorgelagerte Stufen der Supply Chain oder auf Supply-Chain-Dienstleister sowie die Internationalisierung der Beschaffung. Dieser Paradigmenwechsel hat traditionelles Denken in den Schranken des Systems „Unternehmen“ abgelöst und zum Supply- Chain-Denken geführt, das vor......- und nachgelagerte Stufen des Systems „End-to-End-Supply-Chain“ einbezieht, etwa auch die Lieferanten von Lieferanten....

  18. Social Media and Supply Chain

    Directory of Open Access Journals (Sweden)

    Sonja Markova

    2013-02-01

    Full Text Available Web 2.0, also referred to as social media, is the use of the World Wide Web to increase creativity, information sharing, and collaboration among users. Social media is driving the rethinking of many of the principles of economics. The use of social media within supply chains is lagging behind their usage for other operational functions, however supply chain management is evolving into supply chain management 2.0.The purpose of this article is to provide researches of the supply chain management a reference with the main concepts of social media: social profiles, social applications, brand outposts and communities, and the social ecosystem.

  19. Integrating the healthcare supply chain.

    Science.gov (United States)

    Brennan, C D

    1998-01-01

    Today's integrated delivery systems (IDSs) require efficient supply chain processes to speed products to users at the lowest possible cost. Most excess costs within the supply chain are a result of inefficient and redundant processes involved in the transport and delivery of supplies from suppliers to healthcare providers. By integrating and assuming control of these supply chain processes, improving supply chain management practices, and organizing and implementing a disciplined redesign plan, IDSs can achieve substantial savings and better focus their organizations on their core patient care mission.

  20. Technology transfer by multinationals

    OpenAIRE

    2003-01-01

    The paper analyses the issue of technology transfer by multinational corporations. The following questions are explored: (a) world market of technologies, the role of MNCs (b) Choice of the technology transfer mode, Dunning's OLI-theory as a factor of the choice of the mode of transfer (c) measurement and profitability of technology transfer (d) transfer of technology through partnerships, JVs, alliances and through M&As (e) aspects of technology transfer by services multinationals. Paper uti...

  1. Transfers of entanglement qudit states in quantum networks

    CERN Document Server

    Sawerwain, Marek

    2013-01-01

    The issue of quantum states' transfer -- in particular, for so-called Perfect State Transfer (PST) -- in the networks represented by the spin chains seems to be one of the major concerns in quantum computing. Especially, in the context of future communication methods that can be used in broadly defined computer science. The chapter presents a definition of Hamiltonian describing the dynamics of quantum data transfer in one-dimensional spin chain, which is able to transfer the state of unknown qudits. The main part of the chapter is the discussion about possibility of entangled states' perfect transfer, in particular, for the generalized Bell states for qudits. One of the sections also contains the results of numerical experiments for the transmission of quantum entangled state in a noisy quantum channel.

  2. Heme electron transfer in peroxidases: the propionate e-pathway.

    Science.gov (United States)

    Guallar, Victor

    2008-10-23

    Computational modeling offers a new insight about the electron transfer pathway in heme peroxidases. Available crystal structures have revealed an intriguing arrangement of the heme propionate side chains in heme-heme and heme-substrate complexes. By means of mixed quantum mechanical/molecular mechanics calculations, we study the involvement of these propionate groups into the substrate oxidation in ascorbate peroxidase and into the heme to heme electron transfer in bacterial cytochrome c peroxidase. By selectively turning on/off different quantum regions, we obtain the electron transfer pathway which directly involves the porphyrin ring and the heme propionates. Furthermore, in ascorbate peroxidase the presence of the substrate appears to be crucial for the activation of the electron transfer channel. The results might represent a general motif for electron transfer from/to the heme group and change our view for the propionate side chains as simple electrostatic binding anchors. We name the new mechanism "the propionate e-pathway".

  3. Requirements of supply chain management in differentiating European pork chains

    NARCIS (Netherlands)

    Trienekens, J.H.; Wognum, P.M.

    2013-01-01

    This paper summarizes results obtained by research into pork chain management in the EU Integrated Project Q-Porkchains. Changing demands for intrinsic and extrinsic quality attributes of pork products impact the way supply chain management should be organized from the farmer down to the consumer. T

  4. Spectral gaps and mode localization in Fibonacci chains of metal nanoparticles.

    Science.gov (United States)

    Dal Negro, Luca; Feng, Ning-Ning

    2007-10-29

    In this paper we study the spectral, localization and dispersion properties of dipolar modes in quasi-periodically modulated nanoparticle chains based on the Fibonacci sequence. By developing a transfer matrix approach for the calculation of resonant frequencies, oscillation eigenvectors and integrated density of states (IDS) of spatially-modulated dipole chains, we demonstrate the presence of large spectral gaps and calculate the pseudo-dispersion diagram of Fibonacci plasmonic chains. The presence of plasmonic band-gaps and localized states in metal nanoparticle chains based on quasi-periodic order can have a large impact in the design and fabrication of novel nanophotonics devices.

  5. SUPPLY CHAIN STRATEGIES IN THE CONTEXT OF AN E-COMMERCE CHAIN (E-CHAIN

    Directory of Open Access Journals (Sweden)

    João Gilberto Mendes do Reis

    2014-05-01

    Full Text Available This paper purpose to explore the relationships between supply chain strategies and product performance in retail e-commerce. In this case, we concern that in current, in order to bear up under competition, organizations have to manage their supply chains so that they meet the needs of their final customers. With this concept in mind, the research presented in this study focuses on establishing the right strategy for supply chains according to their product segment. Thus, after a Literature Review, the paper explain a methodology based in different authors studies. Finally the article focuses on a pratical case in e-commerce retail that describes its application in this field. The research shows that it is possible to use a methodology for classifying supply chains using chain strategies and product features. The use of the right strategy for supply chains will improve the competitive advantage of businesses. One limitation is that the methodology study focuses on only two e-commerce segment; future studies may go further in refining the proposed framework for other segments. The aim of this research is to offer businesses a model for evaluating supply chains, allowing them to improve the performance of their products and services by using the right strategy for supply chains. The classification proposal of this paper presents an original model for classification of supply chains based on different studies on the theme.

  6. From Characters to Quantum (Super)Spin Chains via Fusion

    CERN Document Server

    Kazakov, Vladimir

    2008-01-01

    We give an elementary proof of the Bazhanov-Reshetikhin determinant formula for rational transfer matrices of the twisted quantum super-spin chains associated with the gl(K|M) algebra. This formula describes the most general fusion of transfer matrices in symmetric representations into arbitrary finite dimensional representations of the algebra and is at the heart of analytical Bethe ansatz approach. Our technique represents a systematic generalization of the usual Jacobi-Trudi formula for characters to its quantum analogue using certain group derivatives.

  7. Academic Education Chain Operation Model

    NARCIS (Netherlands)

    Ruskov, Petko; Ruskov, Andrey

    2007-01-01

    This paper presents an approach for modelling the educational processes as a value added chain. It is an attempt to use a business approach to interpret and compile existing business and educational processes towards reference models and suggest an Academic Education Chain Operation Model. The model

  8. Spectral Analysis of Markov Chains

    OpenAIRE

    2007-01-01

    The paper deals with the problem of a statistical analysis of Markov chains connected with the spectral density. We present the expressions for the function of spectral density. These expressions may be used to estimate the parameter of the Markov chain.

  9. LEAN SUPPLY CHAIN DESIGN PRINCIPLES

    OpenAIRE

    Kozlov, Aleksandr

    2015-01-01

    The article presents a set of principles, which can guide the design of lean supply chains. The author divides design principles into 3 main categories. The first two sets describe internal production processes while the 3-rd set relates to the entire supply chain.

  10. Negotiations in Supply Chain Management

    DEFF Research Database (Denmark)

    Zachariassen, Frederik

    2008-01-01

    negotiation literature. Subsequently, an empirical case study is presented, which explicitly aims at exploring the role of negotiations between members of a supply chain. Based on the findings, the paper concludes on specific, normative guidelines for negotiations for improved supply chain competitiveness...

  11. Chain formation of metal atoms

    DEFF Research Database (Denmark)

    Bahn, Sune Rastad; Jacobsen, Karsten Wedel

    2001-01-01

    The possibility of formation of single-atomic chains by manipulation of nanocontacts is studied for a selection of metals (Ni, Pd, Pt, Cu, Ag, Au). Molecular dynamics simulations show that the tendency for chain formation is strongest for Au and Pt. Density functional theory calculations indicate...

  12. Verifying the Hanging Chain Model

    Science.gov (United States)

    Karls, Michael A.

    2013-01-01

    The wave equation with variable tension is a classic partial differential equation that can be used to describe the horizontal displacements of a vertical hanging chain with one end fixed and the other end free to move. Using a web camera and TRACKER software to record displacement data from a vibrating hanging chain, we verify a modified version…

  13. Supply chain integration in the South African conveyancing environment

    Directory of Open Access Journals (Sweden)

    Anthea P. Amadi-Echendu

    2016-01-01

    Full Text Available Background: Although conveyancing is a legal term, business management and specifically operations management principles also apply to the processes involved in conveyancing. From a business perspective, each organisation is usually concerned with its own profit margins and processes. In our global market, however, organisations now realise that they can no longer compete successfully on the basis of their internal operational efficiencies alone. They are therefore constantly aware of the need to improve not only their internal processes but also their alignment with other supply chain linkages in an effort to optimise the performance of the whole supply chain. Such alignment, in the conveyancing environment, includes government departments that are generally less willing to adopt business principles, which in turn makes optimisation of the whole supply chain more difficult.Objectives: The article describes a supply chain perspective of the conveyancing processes in South Africa and reports some of the factors that influence and delay conveyancing transactions. It explores possibilities of collaborative relationships between different role players in the conveyancing supply chain. It aims to show that a supply chain approach, as opposed to a singular organisational approach, can help to reduce process bottlenecks and delays in order to improve overall process efficiency.Method: The research, on which the findings are based, was exploratory in nature and followed a mixed-methods (quantitative or qualitative approach and included both structured questionnaires and personal interviews.Results: The results of the study revealed that many different types of delays occur at various entities across the whole supply chain involved in property transfers. These delays are presented in a table and diagram.Conclusion: It is recommended that greater adoption of electronic technology across the whole supply chain would improve overall efficiency, eliminate

  14. Transfer Entropy as a Log-Likelihood Ratio

    Science.gov (United States)

    Barnett, Lionel; Bossomaier, Terry

    2012-09-01

    Transfer entropy, an information-theoretic measure of time-directed information transfer between joint processes, has steadily gained popularity in the analysis of complex stochastic dynamics in diverse fields, including the neurosciences, ecology, climatology, and econometrics. We show that for a broad class of predictive models, the log-likelihood ratio test statistic for the null hypothesis of zero transfer entropy is a consistent estimator for the transfer entropy itself. For finite Markov chains, furthermore, no explicit model is required. In the general case, an asymptotic χ2 distribution is established for the transfer entropy estimator. The result generalizes the equivalence in the Gaussian case of transfer entropy and Granger causality, a statistical notion of causal influence based on prediction via vector autoregression, and establishes a fundamental connection between directed information transfer and causality in the Wiener-Granger sense.

  15. Knowledge Transfer Planning and Execution in Offshore Outsourcing

    DEFF Research Database (Denmark)

    Madsen, Sabine; Bødker, Keld; Tøth, Thomas

    2015-01-01

    In this paper, we report from a longitudinal project about knowledge transfer conducted in a major financial company headquartered in Denmark and an offshore development center located in Bangalore, India. We identify the main knowledge transfer challenges experienced by the case company. The cha......In this paper, we report from a longitudinal project about knowledge transfer conducted in a major financial company headquartered in Denmark and an offshore development center located in Bangalore, India. We identify the main knowledge transfer challenges experienced by the case company...

  16. Developing sustainable food supply chains.

    Science.gov (United States)

    Smith, B Gail

    2008-02-27

    This paper reviews the opportunities available for food businesses to encourage consumers to eat healthier and more nutritious diets, to invest in more sustainable manufacturing and distribution systems and to develop procurement systems based on more sustainable forms of agriculture. The important factors in developing more sustainable supply chains are identified as the type of supply chain involved and the individual business attitude to extending responsibility for product quality into social and environmental performance within their own supply chains. Interpersonal trust and working to standards are both important to build more sustainable local and many conserved food supply chains, but inadequate to transform mainstream agriculture and raw material supplies to the manufactured and commodity food markets. Cooperation among food manufacturers, retailers, NGOs, governmental and farmers' organizations is vital in order to raise standards for some supply chains and to enable farmers to adopt more sustainable agricultural practices.

  17. Managing the Global Supply Chain

    DEFF Research Database (Denmark)

    Hsuan, Juliana; Skjøtt-Larsen, Tage; Kinra, Aseem

    edition has been fully updated with recent changes in concepts, technology and practice. Integration and collaboration are keywords in future competition. Firms must be agile and lean at the same time. The book gives an insightful overview of the conceptual foundations of the global supply chain, as......The world today faces global competition. The supply chain is vital part of the globalization process. Presenting a global view of the scope and complexity of supply chain management, this book reflects the rapid change that has taken place within the supply chain and its environment. This new...... well as current examples of best practice of managing supply chains in a global context....

  18. Environmental Management in Product Chains

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard; Forman, Marianne

    2009-01-01

    ). An overview of examples from our own research and from literature of the type and the role of environmental issues and initiatives in product chains (fourth section). A typology for characterizing corporate strategies as part of environmental management in product chains and characterizing those competencies......The chapter aims at giving background to companies, consultants, governmental regulators, NGOs etc. for the analysis and planning of environmental management in specific product chains through: A framework for understanding environmental management in product chains as shaped by the interaction...... between existing resources, norms and values and external pressures for environmental management (second section). A model for the types of corporate network relations that need to be mapped and understood in order to analyze and/or develop environmental management in a product chain (third section...

  19. The Service-Profit Chain

    DEFF Research Database (Denmark)

    Grønholdt, Lars; Martensen, Anne

    2016-01-01

    evidence of the employee-customer-profit chain. As it is possible to estimate the links, we have demonstrated their effect on company profitability. The research findings provide a better understanding of the service-profit chain and may help practitioners in improving company financial performance.......This paper examines the links between employee attitudes, customer loyalty and company profitability. From a conceptual point of view, this employee-customer-profit chain, also known as the service-profit chain, is well founded and generally accepted. But for many companies, it seems difficult...... to demonstrate such links, and several issues must be addressed to uncover the links. To investigate these links empirically, a hotel chain provided data matching employee and customer measures with measures of profitability. We have successfully employed a modeling approach, and the paper reports empirical...

  20. Managing the Global Supply Chain

    DEFF Research Database (Denmark)

    Skjøtt-Larsen, Tage; Schary, Philip B.; Mikkola, Juliana Hsuan

    The world today faces global competition. The supply chain is vital part of the globalization process. Presenting a global view of the scope and complexity of supply chain management, this book reflects the rapid change that has taken place within the supply chain and its environment. This new...... edition has been fully updated with recent changes in concepts, technology and practice. Integration and collaboration are keywords in future competition. Firms must be agile and lean at the same time. The book gives an insightful overview of the conceptual foundations of the global supply chain, as...... well as current examples of best practice of managing supply chains in a global context....

  1. Supply Chain Coordination and Consumer Awareness for Pollution Reduction

    Directory of Open Access Journals (Sweden)

    Bowon Kim

    2016-04-01

    Full Text Available To understand the dynamics of the manufacturer’s effort to reduce pollution in a supply chain consisting of manufacturer, retailer, and consumers, we analyze four cases according to consumer awareness of the pollution’s harmful effect, i.e., environmentally aware versus ignorant, and supply chain coordination, i.e., competitive versus cooperative. Applying differential games, we derive managerial implications: the most significant is that the supply chain coordination strategy becomes irrelevant to reducing the pollution, if the consumers are not environmentally aware or sensitive enough. It highlights the critical role played by the consumer awareness in curbing the pollution in the supply chain. In addition, we find the transfer price and the potential market size are important factors to determine each case’s relative effectiveness. Under a regular condition, where the transfer price from the retailer to the manufacturer is sufficiently high, the consumer-aware and competitive case can generate a better outcome in reducing the pollution than those with ignorant consumers. However, the opposite might occur if the transfer price is excessively low, giving the manufacturer little motivation to make an effort to reduce the pollution. For the cooperative supply chain, it is the potential market size that determines whether the consumer-aware case is better than the consumer-ignorant. In fact, it turns out that there is a stronger result, i.e., the feasibility condition enforces that the market is always big enough to make the consumer-aware cooperative case better than the consumer-ignorant cases. We further discuss managerial as well as policy implications of these analysis outcomes.

  2. Transfer Readiness Pilot Study.

    Science.gov (United States)

    Scott-Skillman, Thelma; And Others

    The California Community Colleges (CCC) has implemented a prototype model for determining student transfer readiness as a primary means of assessing community college transfer effectiveness. This report provides definitions of transfer readiness and guidelines for colleges participating in the CCC transfer readiness study. First, a memorandum from…

  3. Antiferromagnetic sawtooth chain with Heisenberg and Ising bonds

    Directory of Open Access Journals (Sweden)

    V. Ohanyan

    2009-01-01

    Full Text Available The sawtooth chain with pairs of S=1/2 spins interacting with XXZ-interactions placed on each second tooth is considered. All other interaction bonds are taken to be of Ising type. Exact statistical mechanical solution of the model within the direct transfer-matrix technique is obtained. The solution allows one to obtain exact analytic expressions for all thermodynamic functions of the model. Ground state properties are also investigated, the corresponding ground state phase diagram is presented.

  4. Chains, clusters, inclusion compounds, paramagnetic labels, and organic rings

    CERN Document Server

    Zanello, P

    1994-01-01

    The role of stereochemistry to elucidate reaction patterns and physico-chemical properties in topical subjects ranging from inorganic to organic chemistry are treated in the fifth and final volume of this series. Detailed accounts are given to study: chaining in polyphosphates, electron-transfers in carbonyl clusters, inclusion of organometallic molecules in cyclodextrins, stereochemistry of paramagnetic metal complexes by labeling with nitroxyl radicals, stereocontrol in organic syntheses assisted by inorganic complexes.

  5. Knowledge Transfer Services

    Directory of Open Access Journals (Sweden)

    Albert Simard

    2009-03-01

    include independence from content, an organizational focus, scalability, two drivers, and two levels of resolution. The model is based on a value chain in which value is embedded, advanced, or extracted. A knowledge services system comprises nine stages: generate, transform, manage, use internally, transfer, add value, use professionally, use personally, and evaluate. Knowledge services are delivered through a delivery spectrum ranging from rich to reach. Each region of the delivery spectrum has a set of attributes that influence how services should be delivered.

  6. Cryogenic heat transfer

    CERN Document Server

    Barron, Randall F

    2016-01-01

    Cryogenic Heat Transfer, Second Edition continues to address specific heat transfer problems that occur in the cryogenic temperature range where there are distinct differences from conventional heat transfer problems. This updated version examines the use of computer-aided design in cryogenic engineering and emphasizes commonly used computer programs to address modern cryogenic heat transfer problems. It introduces additional topics in cryogenic heat transfer that include latent heat expressions; lumped-capacity transient heat transfer; thermal stresses; Laplace transform solutions; oscillating flow heat transfer, and computer-aided heat exchanger design. It also includes new examples and homework problems throughout the book, and provides ample references for further study.

  7. Research on the Logistics Supply Chain in Port Logistics Transportation

    Directory of Open Access Journals (Sweden)

    Wang Yan-liang

    2013-11-01

    Full Text Available The aim of this study is to improve and increase the logistics system effectiveness and to solve the problem of optimal movement of different flows. Logistics transport carrying the world on material resources transfer exchange important mission and economic development and our lives are closely linked, logistics chain logistics transport occupies an important position and in the e logistics chain in port logistics has play a decisive role. For many coastal countries port logistics is the economic lifeline of the country, on China's economic development role as important, port logistics transport bear the material exchange with the external communication of important role, so the Chinese port logistics transportation research, clear port logistics transportation, current situation, find the existing problems in the light of the problem, to find a suitable method for solving has great realistic meaning. To promote logistics development, improve the logistics supply chain system has play an important role in this filed.

  8. Supersymmetric quantum spin chains and classical integrable systems

    Science.gov (United States)

    Tsuboi, Zengo; Zabrodin, Anton; Zotov, Andrei

    2015-05-01

    For integrable inhomogeneous supersymmetric spin chains (generalized graded magnets) constructed employing Y( gl( N| M))-invariant R-matrices in finite-dimensional representations we introduce the master T-operator which is a sort of generating function for the family of commuting quantum transfer matrices. Any eigenvalue of the master T-operator is the tau-function of the classical mKP hierarchy. It is a polynomial in the spectral parameter which is identified with the 0-th time of the hierarchy. This implies a remarkable relation between the quantum supersymmetric spin chains and classical many-body integrable systems of particles of the Ruijsenaars-Schneider type. As an outcome, we obtain a system of algebraic equations for the spectrum of the spin chain Hamiltonians.

  9. Supersymmetric quantum spin chains and classical integrable systems

    CERN Document Server

    Tsuboi, Zengo; Zotov, Andrei

    2014-01-01

    For integrable inhomogeneous supersymmetric spin chains (generalized graded magnets) constructed employing Y(gl(N|M))-invariant R-matrices in finite-dimensional representations we introduce the master T-operator which is a sort of generating function for the family of commuting quantum transfer matrices. Any eigenvalue of the master T-operator is the tau-function of the classical mKP hierarchy. It is a polynomial in the spectral parameter which is identified with the 0-th time of the hierarchy. This implies a remarkable relation between the quantum supersymmetric spin chains and classical many-body integrable systems of particles of the Ruijsenaars-Schneider type. As an outcome, we obtain a system of algebraic equations for the spectrum of the spin chain Hamiltonians.

  10. Occupancy distributions in Markov chains via Doeblin's ergodicity coefficient

    CERN Document Server

    Chestnut, Stephen

    2010-01-01

    We apply Doeblin's ergodicity coefficient as a computational tool to approximate the occupancy distribution of a set of states in a homogeneous but possibly non-stationary finite Markov chain. Our approximation is based on new properties satisfied by this coefficient, which allow us to approximate a chain of duration n by independent and short-lived realizations of an auxiliary homogeneous Markov chain of duration of order ln(n). Our approximation may be particularly useful when exact calculations via first-step methods or transfer matrices are impractical, and asymptotic approximations may not be yet reliable. Our findings may find applications to pattern problems in Markovian and non-Markovian sequences that are treatable via embedding techniques.

  11. ORGANIC CONTAMINANT DISTRIBUTION IN SEDIMENTS, POLYCHAETES (NEREIS VIRENS) AND THE AMERICAN LOBSTER, HOMARUS AMERICANUS IN A LABORATORY FOOD CHAIN EXPERIMENT

    Science.gov (United States)

    A laboratory experiment was conducted to investigate the transfer of organic contaminants from an environmentally contaminated marine sediment through a simple marine food chain. The infaunal polychaete, Nereis virens, was exposed to contaminated sediment collected from the Passa...

  12. Robustness of spin-coupling distributions for perfect quantum state transfer

    Energy Technology Data Exchange (ETDEWEB)

    Zwick, Analia [Fakultaet Physik, Technische Universitaet Dortmund, D-44221 Dortmund (Germany); Facultad de Matematica, Astronomia y Fisica and Instituto de Fisica Enrique Gaviola, Universidad Nacional de Cordoba, 5000 Cordoba (Argentina); Alvarez, Gonzalo A.; Stolze, Joachim [Fakultaet Physik, Technische Universitaet Dortmund, D-44221 Dortmund (Germany); Osenda, Omar [Facultad de Matematica, Astronomia y Fisica and Instituto de Fisica Enrique Gaviola, Universidad Nacional de Cordoba, 5000 Cordoba (Argentina)

    2011-08-15

    The transmission of quantum information between different parts of a quantum computer is of fundamental importance. Spin chains have been proposed as quantum channels for transferring information. Different configurations for the spin couplings were proposed in order to optimize the transfer. As imperfections in the creation of these specific spin-coupling distributions can never be completely avoided, it is important to find out which systems are optimally suited for information transfer by assessing their robustness against imperfections or disturbances. We analyze different spin coupling distributions of spin chain channels designed for perfect quantum state transfer. In particular, we study the transfer of an initial state from one end of the chain to the other end. We quantify the robustness of different coupling distributions against perturbations and we relate it to the properties of the energy eigenstates and eigenvalues. We find that the localization properties of the systems play an important role for robust quantum state transfer.

  13. Thermal radiation heat transfer

    CERN Document Server

    Howell, John R; Siegel, Robert

    2016-01-01

    Further expanding on the changes made to the fifth edition, Thermal Radiation Heat Transfer, 6th Edition continues to highlight the relevance of thermal radiative transfer and focus on concepts that develop the radiative transfer equation (RTE). The book explains the fundamentals of radiative transfer, introduces the energy and radiative transfer equations, covers a variety of approaches used to gauge radiative heat exchange between different surfaces and structures, and provides solution techniques for solving the RTE.

  14. Elastic Behavior of Polymer Chains

    Institute of Scientific and Technical Information of China (English)

    Teng Lu; Tao Chen; Hao-jun Liang

    2008-01-01

    The elastic behavior of the polymer chain was investigated in a three-dimensional off-lattice model. We sample more than 109 conformations of each kind of polymer chain by using a Monte Carlo algorithm, then analyze them with the non-Gaussian theory of rubberlike elasticity, and end with a statistical study. Through observing the effect of the chain flexibility and the stretching ratio on the mean-square end-to-end distance,the average energy, the average Helmholtz free energy, the elastic force, the contribution of energy to the elastic force, and the entropy contribution to elastic force of the polymer chain, we find that a rigid polymer chain is much easier to stretch than a flexible polymer chain. Also, a rigid polymer chain will become difficult to stretch only at a quite high stretching ratio because of the effect of the entropy contribution.These results of our simulation calculation may explain some of the macroscopic phenomena of polymer and biomacromolecular elasticity.

  15. Traceability in food supply chain:: Towards the synchronised supply chain

    OpenAIRE

    Lindh, Helena; Skjöldebrand, Christina; Olsson, Annika

    2008-01-01

    Today, food products are distributed all over the world. This has led to advantages in terms of availability but disadvantages in terms of more complex food supply chains. Global food competition is intense and therefore actors have started to adapt their mindsets toward a more holistic view and a supply chain perspective. In addition, food scares during recent years have turned focus towards food safety and traceability in a “farm-to-fork” perspective. The aim of this study is to explore...

  16. Markov chains theory and applications

    CERN Document Server

    Sericola, Bruno

    2013-01-01

    Markov chains are a fundamental class of stochastic processes. They are widely used to solve problems in a large number of domains such as operational research, computer science, communication networks and manufacturing systems. The success of Markov chains is mainly due to their simplicity of use, the large number of available theoretical results and the quality of algorithms developed for the numerical evaluation of many metrics of interest.The author presents the theory of both discrete-time and continuous-time homogeneous Markov chains. He carefully examines the explosion phenomenon, the

  17. New sensors and processing chain

    CERN Document Server

    Yaakoubi, Nourdin

    2014-01-01

    A vital tool for researchers, engineers, and students, New Sensors and Processing Chain focuses on the processing chain to set up in order to extract relevant information on various systems. Highlighting the design of new microsensors and various applications, the authors present recent progress in instrumentation and microsystem design, providing insight to the modification of the sensor itself as well as its environment. Various applications illustrate the presentations, which show how a processing chain is organized from the data acquired by a specific sensor.

  18. Supply Chain Shipment Pricing Data

    Data.gov (United States)

    US Agency for International Development — This data set provides supply chain health commodity shipment and pricing data. Specifically, the data set identifies Antiretroviral (ARV) and HIV lab shipments to...

  19. Environmental management in product chains

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard; Forman, Marianne; Hansen, Anne Grethe

    of environmental initiatives, a number of recommendations for governmental regulation, which can support the further diffusion of environmental management in product chains, are developed. Furthermore, the report describes a number of theoretical perspectives from sociology of technology, organisation theory...

  20. Bibliometric Application of Markov Chains.

    Science.gov (United States)

    Pao, Miranda Lee; McCreery, Laurie

    1986-01-01

    A rudimentary description of Markov Chains is presented in order to introduce its use to describe and to predict authors' movements among subareas of the discipline of ethnomusicology. Other possible applications are suggested. (Author)

  1. Gravity Waves from Chain Inflation

    CERN Document Server

    Ashoorioon, Amjad

    2008-01-01

    Chain inflation proceeds through a series of first order phase transitions, which can release considerable gravitational waves (GW). We demonstrate that bubble collisions can leave an observable signature for future high-frequency probes of GWs, such as advanced LIGO, LISA and BBO. A "smoking gun" for chain inflation would be wiggles in the spectrum (and consequently in the tensor spectral index) due to the multiple phase transitions. The spectrum could also be distinguished from a single first order phase transition by a small difference in the amplitude at low frequency. A second origin of GWs in chain inflation are tensor modes from quantum fluctuations; these GW can dominate and be observed on large scales. The consistency relation between scalar and tensor modes is different for chain inflation than for standard rolling models and is testable by Cosmic Microwave Background experiments. If inflation happened through a series of rapid tunnelings in the string landscape, future high frequency probes of GW c...

  2. Markov Chains and Chemical Processes

    Science.gov (United States)

    Miller, P. J.

    1972-01-01

    Views as important the relating of abstract ideas of modern mathematics now being taught in the schools to situations encountered in the sciences. Describes use of matrices and Markov chains to study first-order processes. (Author/DF)

  3. The chain re-action

    CERN Multimedia

    2009-01-01

    On 18 March, beam commissioning started in the first ‘link’ of the accelerator chain – LINAC 2. This marks the start of what will be the longest period of beam operations in CERN’s history, with the accelerator complex remaining operational throughout the winter to supply the LHC. The Bulletin finds out what is being done to make sure the whole chain is ready for this historic run.

  4. The spectral irradiance traceability chain at PTB

    Energy Technology Data Exchange (ETDEWEB)

    Sperfeld, P.; Pape, S.; Nevas, S. [Physikalisch-Technische Bundesanstalt, Bundesallee 10, 381160 Braunschweig (Germany)

    2013-05-10

    Spectral irradiance is a fundamental radiometric unit. Its application to measurement results requires qualified traceability to basic units of the international system of units (Systeme international d'unites, SI). The Physikalisch-Technische Bundesanstalt (PTB) is amongst other national metrological institutes (NMIs) responsible for the realization, maintenance and dissemination of various radiometric and photometric units based on and traceable to national standards. The unit of spectral irradiance is realized and represented by a blackbody-radiator as the national primary standard of the PTB. Based on Planck's radiation law, the irradiance is calculated and realized for any wavelength taking into account the exact knowledge of the radiation temperature and the geometrical parameters. Using a double-monochromator-based spectroradiometer system, secondary standard lamps can be calibrated by direct comparison to the blackbody-radiator (substitution method). These secondary standard lamps are then used at the PTB to calibrate standard lamps of customers. The customers themselves use these so-called transfer standards to calibrate their working standard lamps. These working standards are then used to calibrate own spectroradiometers or sources. This rather complex calibration chain is a common procedural method that for the customers generally leads to satisfying measurement results on site. Nevertheless, the standard lamps in use have to fulfill highest requirements concerning stability and reproducibility. Only this allows achieving comparably low transfer measurement uncertainties, which occur at each calibration step. Thus, the PTB is constantly investigating the improvement and further development of transfer standards and measurement methods for various spectral regions. The realization and dissemination of the spectral irradiance using the blackbody-radiator at the PTB is accomplished with worldwide approved minimized measurement uncertainties

  5. "Bullwhip Effect" in Supply Chains

    Directory of Open Access Journals (Sweden)

    Anđelko Ščukanec

    2007-09-01

    Full Text Available The system which connects all the elements between theproducer and the consumer is called the supply chain. This definitionof the supply chain shows its complexity, dynamics anduncertainty. Successful operation of supply chains requires thebest possible coordination of its elements, which obviously indicatesthe utmost importance of the information flow alongthem. The operation of supply chains on the whole has to bemore successful than the operation of their individual elements.It should be noted that such a complex process may give rise toa series of problems, unwanted events, as well as substantial reductionin profits and the level of service. One of such unwantedphenomena which may occur in the supply chain is the"bullwhip effect". This is a possible increase in the diversity oforders which occurs when we move along the elements of thesupply chain (from the customers' orders to the producers' orders.The work analyses the processes within the supply chainsand the occurrence of the bullwhip effect. The main causes ofthe bullwhip effect that we encounter daily in the supply chainshave been clearly defined. The paper also presents the mainnegative consequences of such a disturbance within the supplychains, and provides possible solutions for avoiding the bullwhipeffect.

  6. Reinforcement learning in supply chains.

    Science.gov (United States)

    Valluri, Annapurna; North, Michael J; Macal, Charles M

    2009-10-01

    Effective management of supply chains creates value and can strategically position companies. In practice, human beings have been found to be both surprisingly successful and disappointingly inept at managing supply chains. The related fields of cognitive psychology and artificial intelligence have postulated a variety of potential mechanisms to explain this behavior. One of the leading candidates is reinforcement learning. This paper applies agent-based modeling to investigate the comparative behavioral consequences of three simple reinforcement learning algorithms in a multi-stage supply chain. For the first time, our findings show that the specific algorithm that is employed can have dramatic effects on the results obtained. Reinforcement learning is found to be valuable in multi-stage supply chains with several learning agents, as independent agents can learn to coordinate their behavior. However, learning in multi-stage supply chains using these postulated approaches from cognitive psychology and artificial intelligence take extremely long time periods to achieve stability which raises questions about their ability to explain behavior in real supply chains. The fact that it takes thousands of periods for agents to learn in this simple multi-agent setting provides new evidence that real world decision makers are unlikely to be using strict reinforcement learning in practice.

  7. Ubiquitin chain conformation regulates recognition and activity of interacting proteins.

    Science.gov (United States)

    Ye, Yu; Blaser, Georg; Horrocks, Mathew H; Ruedas-Rama, Maria J; Ibrahim, Shehu; Zhukov, Alexander A; Orte, Angel; Klenerman, David; Jackson, Sophie E; Komander, David

    2012-12-13

    Mechanisms of protein recognition have been extensively studied for single-domain proteins, but are less well characterized for dynamic multidomain systems. Ubiquitin chains represent a biologically important multidomain system that requires recognition by structurally diverse ubiquitin-interacting proteins. Ubiquitin chain conformations in isolation are often different from conformations observed in ubiquitin-interacting protein complexes, indicating either great dynamic flexibility or extensive chain remodelling upon binding. Using single-molecule fluorescence resonance energy transfer, we show that Lys 63-, Lys 48- and Met 1-linked diubiquitin exist in several distinct conformational states in solution. Lys 63- and Met 1-linked diubiquitin adopt extended 'open' and more compact 'closed' conformations, and ubiquitin-binding domains and deubiquitinases (DUBs) select pre-existing conformations. By contrast, Lys 48-linked diubiquitin adopts predominantly compact conformations. DUBs directly recognize existing conformations, but may also remodel ubiquitin chains to hydrolyse the isopeptide bond. Disruption of the Lys 48-diubiquitin interface changes conformational dynamics and affects DUB activity. Hence, conformational equilibria in ubiquitin chains provide an additional layer of regulation in the ubiquitin system, and distinct conformations observed in differently linked polyubiquitin may contribute to the specificity of ubiquitin-interacting proteins.

  8. ANALYSIS OF IMPACT RESISTANCE OF CHAIN ACCORDING TO SPROCKET LUG PROFILE

    Directory of Open Access Journals (Sweden)

    Berezhnoy S. B.

    2015-03-01

    Full Text Available The possibility of using involute sprockets, more technologically advanced in manufacturing, compared with sprockets with straight, convex-concave profile of the lug on the criterion shock resistance circuit, the maximum permissible speed of the drive sprocket for bush roller chain drives and gears with a toothed chain. The comparative analysis of researches of operation of roller and tooth chain gearings with various steps and types of profiles of sprockets showed that in all cases with increase in a step of a chain the coefficient of speed of blow increases, and the increase in number of lugs at sprockets reduces the speed of blow of the hinge about sprockets tooth. Value of coefficient of speed of blow for couple an evolvent sprockets - a gear chain is much less than value of coefficient of speed of blow for couple a plug-roller chain –sprockets of any profile. Less noise during the work of tooth chain gearings is due to evolvent sprockets. As a result of researches it is established that on kinetic energy of impact of sprockets and the hinge of a chain, sprockets with an evolvent profile can be applied on an equal basis with the sprockets having concave-convex or rectilinear profiles of lugs. Respectively, evolvent sprockets can be used both in chain transfers with roller and with gear chains

  9. Gluon chains and the quark-antiquark potential

    CERN Document Server

    Greensite, J

    2009-01-01

    The flux tube between a quark and an antiquark in Coulomb gauge is imagined in the gluon-chain model as a sequence of constituent gluons bound together by Coulombic nearest-neighbor interactions. We diagonalize the transfer matrix in SU(2) lattice gauge theory in a finite basis of states containing a static quark-antiquark pair together with zero, one, and two gluons in Coulomb gauge. We show that while the string tension of the color-Coulomb potential (obtained from the zero-gluon to zero-gluon element of the transfer matrix) overshoots the true asymptotic string tension by a factor of about three, the inclusion of a few states with constituent gluons reduces the discrepancy considerably. The minimal energy eigenstate of the transfer matrix in the zero-, one-, and two-gluon basis exhibits a linearly rising potential with the string tension only about 1.4 times larger than the asymptotic one.

  10. Sports Nutrition Food Industry Chain Development Research

    OpenAIRE

    Jie Yin

    2015-01-01

    Through the study of Henan sports nutrition food industry chain optimization, the study analyses development advantage and competitive advantage of Henan in sports nutrition food industry chain and existing problems and challenges in Henan sports nutrition food industry chain and at the same time introduces the theory of supply chain management to the development of sports nutrition food industry chain, clearly optimizes countermeasures of sports nutrition food industry chain. Pointing out sp...

  11. The warm chain.

    Science.gov (United States)

    Bowers, J Z

    1985-01-01

    1 series of events carried smallpox vaccination on an eastward odyssey; a 2nd path led westward from Spain to Spanish America, to the Philippines, and to China. Francisco Xavier Balmis (1753-1819), a Spanish physician, sailed around the world in 3 years, establishing vaccination boards in South America, the Philippines, and China. He led the "Real Expedicion Martima de la Vacuna," sponsored by the Bourbon King Charles IV; its success derived from arm-to-arm passage of the virus using orphan boys on the long voyages across the Atlantic and Pacific oceans. Venezuela was the 1st country to which Balmis introduced vaccine. He divided the expedition with his deputy, Slavany, who was to lead 1 group through the Spanish colonies in the Vice-Royalty of Peru; Balmis would lead the other group across the Vice-Royalty of New Spain to the far-distant colony in the Philippines. The establishment of central boards to regulate vaccination became one of Balmis's principal preoccupations. The board he created in Venezuela served as the model for those that he and Salvany were to establish later. Balmis sailed to Havana from La Guaira on May 8, 1804; Salvany led his team to Bogota. Balmis's singular success in Caracas, and Salvany's in Bogota, where Salvany also created a Central Vaccination Board, were attributable in large measure to the total support they received from church and civil authorites. The Portuguese throne had a comparable interest in its prize colony, Brazil. In 1804, Felisberto Calderia Brant Pontes sent a group of slave children from Bahia to Lisbon so that arm-to-arm transfer could be made on the return voyage. His effort was successful, and 1335 persons had been vaccinated in Bahia by June 1, 1804. In a decree of September 3, 1803 Charles IV directed that the Balmis expedition should continue to the Philippines. The advancement of health in the Philippines was a major commitment of the Spaniards. The Philippine vaccination expedition, headed by Balmis, sailed

  12. Demand chain management - The evolution

    Directory of Open Access Journals (Sweden)

    D Ericsson

    2011-06-01

    Full Text Available The concepts of Supply Chain Management (SCM and Demand Chain Management (DCM are among the new and debated topics concerning logistics in the literature. The question considered in this paper is: “Are these concepts needed or will they just add to the confusion?” Lasting business concepts have always evolved in close interaction between business and academia. Different approaches start out in business and they are then, more or less si- multaneously, aligned, integrated, systemised and structured in academia. In this way a terminology (or language is provided that helps in further diffusion of the concepts. There is a lack of consensus on the definition of the concept of SCM. This may be one of the major reasons for the difficulty in advancing the science and measuring the results of implementation in business. Relationships in SCM span from rather loose coalitions to highly structured virtual network integrations. DCM is a highly organised chain in which the key is mutual interdependence and partnership. The purpose is to create a distinctive competence for the chain as a whole that helps to identify and satisfy customer needs and wishes. The classical research concerning vertical marketing systems is very helpful in systemising the rather unstructured discussions in current SCM research. The trend lies in increasing competition between channels rather than between companies, which in turn leads to the creation of channels with a high degree of partnership and mutual interdependence between members. These types of channels are known as organised vertical marketing systems in the classic marketing channel research. The behaviour in these types of channels, as well as the formal and informal structures, roles in the network, power and dependence relations, etc. are well covered topics in the literature. The concept of vertical marketing systems lies behind the definition of demand chains and demand chain management proposed in this paper. A

  13. Convective heat transfer

    CERN Document Server

    Kakac, Sadik; Pramuanjaroenkij, Anchasa

    2014-01-01

    Intended for readers who have taken a basic heat transfer course and have a basic knowledge of thermodynamics, heat transfer, fluid mechanics, and differential equations, Convective Heat Transfer, Third Edition provides an overview of phenomenological convective heat transfer. This book combines applications of engineering with the basic concepts of convection. It offers a clear and balanced presentation of essential topics using both traditional and numerical methods. The text addresses emerging science and technology matters, and highlights biomedical applications and energy technologies. What’s New in the Third Edition: Includes updated chapters and two new chapters on heat transfer in microchannels and heat transfer with nanofluids Expands problem sets and introduces new correlations and solved examples Provides more coverage of numerical/computer methods The third edition details the new research areas of heat transfer in microchannels and the enhancement of convective heat transfer with nanofluids....

  14. Introduction to heat transfer

    CERN Document Server

    SUNDÉN, B

    2012-01-01

    Presenting the basic mechanisms for transfer of heat, Introduction to Heat Transfer gives a deeper and more comprehensive view than existing titles on the subject. Derivation and presentation of analytical and empirical methods are provided for calculation of heat transfer rates and temperature fields as well as pressure drop. The book covers thermal conduction, forced and natural laminar and turbulent convective heat transfer, thermal radiation including participating media, condensation, evaporation and heat exchangers.

  15. Marked Continuous-Time Markov Chain Modelling of Burst Behaviour for Single Ion Channels

    Directory of Open Access Journals (Sweden)

    Frank G. Ball

    2007-01-01

    a continuous-time Markov chain with a finite-state space. We show how the use of marked continuous-time Markov chains can simplify the derivation of (i the distributions of several burst properties, including the total open time, the total charge transfer, and the number of openings in a burst, and (ii the form of these distributions when the underlying gating process is time reversible and in equilibrium.

  16. Transfer of gaming

    NARCIS (Netherlands)

    Korteling, J.E.

    2012-01-01

    An overview is provided of the activities and results op GATE WP 4.4 entiteld Transfer of Gaming (ToG). This work package has produced the principles and methodologies concerning optimalization and measurement of transfer of training in serious gaming. In addition, true transfer of job-specific comp

  17. Robustness of spin-coupling distributions for perfect quantum state transfer

    CERN Document Server

    Zwick, Analia; Stolze, Joachim; Osenda, Omar

    2011-01-01

    The transmission of quantum information between different parts of a quantum computer is of fundamental importance. Spin chains have been proposed as quantum channels for transferring information. Different configurations for the spin couplings were proposed in order to optimize the transfer. As imperfections in the creation of these specific spin-coupling distributions can never be completely avoided, it is important to find out which systems are optimally suited for information transfer by assessing their robustness against imperfections or disturbances. We analyze different spin coupling distributions of spin chain channels designed for perfect quantum state transfer. In particular, we study the transfer of an initial state from one end of the chain to the other end. We quantify the robustness of different coupling distributions against perturbations and we relate it to the properties of the energy eigenstates and eigenvalues. We find that the localization properties of the systems play an important role f...

  18. Electron transfer reactions

    CERN Document Server

    Cannon, R D

    2013-01-01

    Electron Transfer Reactions deals with the mechanisms of electron transfer reactions between metal ions in solution, as well as the electron exchange between atoms or molecules in either the gaseous or solid state. The book is divided into three parts. Part 1 covers the electron transfer between atoms and molecules in the gas state. Part 2 tackles the reaction paths of oxidation states and binuclear intermediates, as well as the mechanisms of electron transfer. Part 3 discusses the theories and models of the electron transfer process; theories and experiments involving bridged electron transfe

  19. Thermoresponsive AuNPs Stabilized by Pillararene-Containing Polymers.

    Science.gov (United States)

    Liao, Xiaojuan; Guo, Lei; Chang, Junxia; Liu, Sha; Xie, Meiran; Chen, Guosong

    2015-08-01

    Pillararene-containing thermoresponsive polymers are synthesized via reversible addition-fragmentation chain transfer polymerization using pillararene derivatives as the effective chain transfer agents for the first time. These polymers can self-assemble into micelles and form vesicles after guest molecules are added. Furthermore, such functional polymers can be further applied to prepare hybrid gold nanoparticles, which integrate the thermoresponsivity of polymers and molecular recognition of pillararenes.

  20. Transfer function combinations

    KAUST Repository

    Zhou, Liang

    2012-10-01

    Direct volume rendering has been an active area of research for over two decades. Transfer function design remains a difficult task since current methods, such as traditional 1D and 2D transfer functions, are not always effective for all data sets. Various 1D or 2D transfer function spaces have been proposed to improve classification exploiting different aspects, such as using the gradient magnitude for boundary location and statistical, occlusion, or size metrics. In this paper, we present a novel transfer function method which can provide more specificity for data classification by combining different transfer function spaces. In this work, a 2D transfer function can be combined with 1D transfer functions which improve the classification. Specifically, we use the traditional 2D scalar/gradient magnitude, 2D statistical, and 2D occlusion spectrum transfer functions and combine these with occlusion and/or size-based transfer functions to provide better specificity. We demonstrate the usefulness of the new method by comparing to the following previous techniques: 2D gradient magnitude, 2D occlusion spectrum, 2D statistical transfer functions and 2D size based transfer functions. © 2012 Elsevier Ltd.

  1. Making benefit transfers work

    DEFF Research Database (Denmark)

    Bateman, I.J.; Brouwer, R.; Ferrini, S.

    We develop and test guidance principles for benefits transfers. These argue that when transferring across relatively similar sites, simple mean value transfers are to be preferred but that when sites are relatively dissimilar then value function transfers will yield lower errors. The paper also...... provides guidance on the appropriate specification of transferable value functions arguing that these should be developed from theoretical rather than ad-hoc statistical principles. These principles are tested via a common format valuation study of water quality improvements across five countries. Results...... support our various hypotheses providing a set of principles for future transfer studies. The application also considers new ways of incorporating distance decay, substitution and framing effects within transfers and presents a novel water quality ladder....

  2. Making benefit transfers work

    DEFF Research Database (Denmark)

    Bateman, I. J.; Brouwer, R.; Ferrini, S.

    2011-01-01

    We develop and test guidance principles for benefits transfers. These argue that when transferring across relatively similar sites, simple mean value transfers are to be preferred but that when sites are relatively dissimilar then value function transfers will yield lower errors. The paper also...... provides guidance on the appropriate specification of transferable value functions arguing that these should be developed from theoretical rather than ad-hoc statistical principles. These principles are tested via a common format valuation study of water quality improvements across five countries. Results...... support our various hypotheses providing a set of principles for future transfer studies. The application also considers new ways of incorporating distance decay, substitution and framing effects within transfers and presents a novel water quality ladder....

  3. Tunneling magnetoresistance of silicon chains

    Science.gov (United States)

    Matsuura, Yukihito

    2016-05-01

    The tunneling magnetoresistance (TMR) of a silicon chain sandwiched between nickel electrodes was examined by using first-principles density functional theory. The relative orientation of the magnetization in a parallel-alignment (PA) configuration of two nickel electrodes enhanced the current with a bias less than 0.4 V compared with that in an antiparallel-alignment configuration. Consequently, the silicon chain-nickel electrodes yielded good TMR characteristics. In addition, there was polarized spin current in the PA configuration. The spin polarization of sulfur atoms functioning as a linking bridge between the chain and nickel electrode played an important role in the magnetic effects of the electric current. Moreover, the hybridization of the sulfur 3p orbital and σ-conjugated silicon 3p orbital contributed to increasing the total current.

  4. MODELING SUPPLY CHAIN PERFORMANCE VARIABLES

    Directory of Open Access Journals (Sweden)

    Ashish Agarwal

    2005-01-01

    Full Text Available In order to understand the dynamic behavior of the variables that can play a major role in the performance improvement in a supply chain, a System Dynamics-based model is proposed. The model provides an effective framework for analyzing different variables affecting supply chain performance. Among different variables, a causal relationship among different variables has been identified. Variables emanating from performance measures such as gaps in customer satisfaction, cost minimization, lead-time reduction, service level improvement and quality improvement have been identified as goal-seeking loops. The proposed System Dynamics-based model analyzes the affect of dynamic behavior of variables for a period of 10 years on performance of case supply chain in auto business.

  5. Who Manages Our Supply Chains?

    DEFF Research Database (Denmark)

    Flöthmann, Christoph

    to manage the manifold tasks they face on a daily basis. Unfortunately, as globalization has simultaneously increased the complexity of supply chains and the demand for highly qualified personnel, companies are facing a significant undersupply of talent (Cottrill, 2010). Moreover, organizations appear......While managers in traditional management functions focus on developing strong expertise to become “specialists” in their own discipline, supply chain managers are a different species: They have to combine a cross-functional understanding of various business fields and multi-faceted competencies...... to lack understanding of supply chain personnel and how to support their recruitment, succession planning, and training and development (John, 2015). Surprisingly, at the same time, scientific research on that topic is relatively scarce. In response, the overarching purpose of this paper...

  6. Designing the Reverse Supply Chain

    DEFF Research Database (Denmark)

    Gobbi, Chiara

    2011-01-01

    for the reverse supply chain. Design/methodology/approach – In order to identify the relevance of the Fisher model, the model needs to be recast in terms of PRV, which, in this context, is considered the independent variable in the reverse logistics arena. Products defined as innovative in Fisher's taxonomy......Purpose – The purpose of this paper is to explore the impact of the product residual value (PRV) and the loss of value over time of returned products in the reverse supply chain configuration. It also examines whether or not the distinction of Fisher's functional and innovative products holds...... correspond to disposed products with high residual value, whereas functional products correspond to disposed products with low residual value. Furthermore, the PRV and the speed at which returned products lose their value are considered in order to determine the configuration of the reverse supply chain...

  7. Extended State to Localization in Random Aperiodic Chains

    Institute of Scientific and Technical Information of China (English)

    GAO Hui-Fen; TAO Rui-Bao

    2006-01-01

    The electronic states in Thus-Morse chain (TMC) and generalized Fibonacci chain (GFC) are studied by solving eigenequation and using transfer matrix method. Two model Hamiltonians are studied. One contains the nearest neighbor (n.n.) hopping terms only and the other has additionally next nearest neighbor (n.n.n.) hopping terms. Based on the transfer matrix method, a criterion of transition from the extended to the localized states is suggested for GFC and TMC. The numerical calculation shows the existence of both extended and localized states in pure aperiodic system. A random potential is introduced to the diagonal term of the Hamiltonian and then the extended states are always changed to be localized. The exponents related to the localization length as a function of randomness are calculated. For different kinds of aperiodic chain, the critical value of randomness for the transition from extended to the localized states are found to be zero, consistent with the case of ordinary one-dimensional systems.

  8. Singular eigenstates in the even(odd) length Heisenberg spin chain

    CERN Document Server

    Giri, Pulak Ranjan

    2014-01-01

    Introducing a regularization scheme, we derive a set of equations for the rapidities of the singular solutions, whose distinct and self-conjugate solutions produce Bethe eigenstates. We obtain singular eigenstates and their corresponding eigenvalues of the transfer matrix of the spin-1/2 XXX chain. For an even length spin-1/2 XXX chain, we show that the singular solutions \\{\\lambda_\\alpha\\} are invariant under the sign changes of their rapidities, \\{\\lambda_\\alpha\\}=\\{-\\lambda_\\alpha\\}. For odd N length spin-1/2 chain in the three down-spin sector, it has been analytically shown that there exist singular solutions in any finite length of the spin chain of the form N= 3\\left(2k+1\\right) with k=1, 2, 3, \\cdots. It is also shown that there exist no singular solutions in the four down-spin sector for some odd length spin-1/2 XXX chains.

  9. Quantum information storage and state transfer based on spin systems

    CERN Document Server

    Song, Z

    2004-01-01

    The idea of quantum state storage is generalized to describe the coherent transfer of quantum information through a coherent data bus. In this universal framework, we comprehensively review our recent systematical investigations to explore the possibility of implementing the physical processes of quantum information storage and state transfer by using quantum spin systems, which may be an isotropic antiferromagnetic spin ladder system or a ferromagnetic Heisenberg spin chain. Our studies emphasize the physical mechanisms and the fundamental problems behind the various protocols for the storage and transfer of quantum information in solid state systems.

  10. Markov chains and mixing times

    CERN Document Server

    Levin, David A; Wilmer, Elizabeth L

    2009-01-01

    This book is an introduction to the modern approach to the theory of Markov chains. The main goal of this approach is to determine the rate of convergence of a Markov chain to the stationary distribution as a function of the size and geometry of the state space. The authors develop the key tools for estimating convergence times, including coupling, strong stationary times, and spectral methods. Whenever possible, probabilistic methods are emphasized. The book includes many examples and provides brief introductions to some central models of statistical mechanics. Also provided are accounts of r

  11. Quantum crystals and spin chains

    Energy Technology Data Exchange (ETDEWEB)

    Dijkgraaf, Robbert [KdV Institute for Mathematics, University of Amsterdam, Plantage Muidergracht 24, 1018 TV Amsterdam (Netherlands); Institute for Theoretical Physics, University of Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam (Netherlands); Orlando, Domenico [Institut de Physique, Universite de Neuchatel, Rue Breguet 1, CH-2000 Neuchatel (Switzerland); Reffert, Susanne [Institute for Theoretical Physics, University of Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam (Netherlands)], E-mail: sreffert@gmail.com

    2009-04-21

    In this article, we discuss the quantum version of the melting crystal corner in one, two, and three dimensions, generalizing the treatment for the quantum dimer model. Using a mapping to spin chains we find that the two-dimensional case (growth of random partitions) is integrable and leads directly to the Hamiltonian of the Heisenberg XXZ ferromagnet. The three-dimensional case of the melting crystal corner is described in terms of a system of coupled XXZ spin chains. We give a conjecture for its mass gap and analyze the system numerically.

  12. Quantum crystals and spin chains

    Science.gov (United States)

    Dijkgraaf, Robbert; Orlando, Domenico; Reffert, Susanne

    2009-04-01

    In this article, we discuss the quantum version of the melting crystal corner in one, two, and three dimensions, generalizing the treatment for the quantum dimer model. Using a mapping to spin chains we find that the two-dimensional case (growth of random partitions) is integrable and leads directly to the Hamiltonian of the Heisenberg XXZ ferromagnet. The three-dimensional case of the melting crystal corner is described in terms of a system of coupled XXZ spin chains. We give a conjecture for its mass gap and analyze the system numerically.

  13. Thermodynamics of Dipolar Chain Systems

    DEFF Research Database (Denmark)

    R. Armstrong, J.; Zinner, Nikolaj Thomas; V. Fedorov, D.

    2012-01-01

    The thermodynamics of a quantum system of layers containing perpendicularly oriented dipolar molecules is studied within an oscillator approximation for both bosonic and fermionic species. The system is assumed to be built from chains with one molecule in each layer. We consider the effects...... numerically. Our findings indicate that thermodynamic observables, such as the heat capacity, can be used to probe the signatures of the intralayer interaction between chains. This should be relevant for near future experiments on polar molecules with strong dipole moments....

  14. Integrity and efficiency in LNG transfer operations with flexible hoses

    NARCIS (Netherlands)

    Bokhorst, E. van; Twerda, A.

    2014-01-01

    The work presented contributes to the LNG supply chain by the development of a validated calculation model for corrugated flexible hoses or pipes developed for LNG Transfer. The model builds upon experience gained by TNO Technical Sciences (Fluid Dynamics) in a large number of flow tests carried out

  15. Reseach of Supply Chain Modeling Technology

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The supply chain modeling technology is research. Firstly, the concept of supply chain and supply chain management is introduced. Secondly, enterprise-modeling methods, such as CIM-OSA, GIM-GRAI, PERA and ARIS, are analyzed and compared. The supply chain modeling technology is studied. Then the ARIS-based supply chain modeling method is proposed and the supply chain operation reference model is set up. Finally, the applications of ARIS-based supply chain modeling method in Shanghai Turbine Generator Co. Ltd. (STGC) is described in detail.

  16. Molecularly Imprinted Polymers on Chloromethyl Polystyrene Resin Prepared via RAFT Polymerization

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Surface molecularly imprinted polymers (SMIP) was prepared via the reversible addition-fragmentation chain transfer (RAFT) polymerization on the chloromethyl polystyrene resin (CPR) in the presence of the template D-phenylalanine. The structure of SMIP was characterized by FTIR and SEM. The adsorption behavior of D-phenylalanine of SMIP was preliminarily investigated.

  17. Quantum state transfer in optomechanical arrays

    Science.gov (United States)

    de Moraes Neto, G. D.; Andrade, F. M.; Montenegro, V.; Bose, S.

    2016-06-01

    Quantum state transfer between distant nodes is at the heart of quantum processing and quantum networking. Stimulated by this, we propose a scheme where one can achieve quantum state transfer with a high fidelity between sites in a cavity quantum optomechanical network. In our lattice, each individual site is composed of a localized mechanical mode which interacts with a laser-driven cavity mode via radiation pressure, while photons hop between neighboring sites. After diagonalization of the Hamiltonian of each cell, we show that the system can be reduced to an effective Hamiltonian of two decoupled bosonic chains, and therefore we can apply the well-known results in quantum state transfer together with an additional condition on the transfer times. In fact, we show that our transfer protocol works for any arbitrary joint quantum state of a mechanical and an optical mode. Finally, in order to analyze a more realistic scenario we take into account the effects of independent thermal reservoirs for each site. By solving the standard master equation within the Born-Markov approximation, we reassure both the effective model and the feasibility of our protocol.

  18. Supply chain management and optimization in manufacturing

    CERN Document Server

    Pirim, Harun; Yilbas, Bekir Sami

    2014-01-01

    This book introduces general supply chain terminology particularly for novice readers, state of the art supply chain management and optimization issues and problems in manufacturing. The book provides insights for making supply chain decisions, planning and scheduling through supply chain network. It introduces optimization problems, i.e. transportation of raw materials, products and location, inventory of plants, warehouses and retailers, faced throughout the supply chain network.

  19. Precise low cost chain gears for heliostats

    Science.gov (United States)

    Liedke, Phillip; Lewandowski, Arkadiusz; Pfahl, Andreas; Hölle, Erwin

    2016-05-01

    This work investigates the potential of chain gears as precise and low cost driving systems for rim drive heliostats. After explaining chain gear basics the polygon effect and chain lengthening are investigated. The polygon effect could be measured by a heliostat with chain rim gear and the chain lengthening with an accordant test set up. Two gear stages are scope of this work: a rim gear and an intermediate gear. Dimensioning, pretensioning and designing for both stages are explained.

  20. Social Value Propagation for Supply Chain Formation

    OpenAIRE

    2013-01-01

    Supply Chain Formation is the process of determining the participants in a supply chain, who will exchange what with whom, and the terms of the exchanges. Decentralized supply chain formation appears as a highly intricate task because agents only possess local information, have limited knowledge about the capabilities of other agents, and prefer to preserve privacy. State-of-the-art decentralized supply chain formation approaches can either: (i) #12;find supply chains of high value at the ...

  1. Information system for the supply chain management

    OpenAIRE

    Delia Adriana Marincas

    2008-01-01

    Supply chain management SCM is the integration and management of supply chain organizations and activities through collaboration, effective business processes and high levels of information sharing. The supply chain concept has become a concern due to global competition and increasing customer demand for value. Thus, the information must be available in real time across the supply chain and this can not be achieved without an integrated software system for supply chain management. Supply chai...

  2. OVERVIEW OF CHINESE CHAIN CATERING MARKET

    OpenAIRE

    2012-01-01

    This thesis is a market overview for chain catering business situation in China. Chinese chain catering market is developing rapidly in recent years, it is a business where everybody can become a customer, but the business is highly competitive. The subject of this thesis is to give an overview of the market situation and strategies for market expansion of Chinese chain catering industry. It contains knowledge of chain management and introduction of Chinese chain catering ma...

  3. SUPPLY CHAIN MANAGEMENT – KEY FACTORS

    OpenAIRE

    Magdalena Daniela DINU

    2014-01-01

    This paper exposes Supply Chain Management by its key factors. Briefly, where the Supply Chain Management is treated as strategic part of a company then maintaining both control and influence throughout the entire supply chain are key factors and critical to success. On the other hand, finding the right partner to manage the non-strategic Supply Chains would be another key factor too. To define the most important key factors within Supply Chain Management means a deeply understanding of bot...

  4. Research on Integrated Green Supply Chain Management

    Institute of Scientific and Technical Information of China (English)

    DENG Lei; WANG Xu

    2006-01-01

    On the basis of the analyzing product life cycle and value chain management in green supply chain, integrated green supply chain is put forward and constructed which involve lean production, agile manufacturing and green supply chain. This integrated structure provides an effective method for resolving some questions such as cost, market, environment, etc. in enterprise. A case study is presented at the end of paper to demonstrate how integrated supply chain implemented successfully in enterprise.

  5. Transferência trófica de mercúrio e selênio na costa norte do Rio de Janeiro Trophic transference of mercury and selenium in the northern coast of Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Helena A. Kehrig

    2009-01-01

    Full Text Available Trophic transfer of trace elements along marine food chains has been recognized as an important process influencing metal and metalloid bioaccumulation. The trophic transfer of mercury was observed between trophic levels from prey (considering fish with different feeding habits and squid to top predator (dolphin in a Northern coastal food chain of Rio de Janeiro. Selenium showed some evidence of trophic transfer between lower trophic levels. Dolphin presented the highest mercury concentrations whereas the benthic carnivorous fish showed the highest selenium concentrations. Mercury is biomagnified through the food chain while selenium does not present the same behavior.

  6. 76 FR 44761 - Remittance Transfers

    Science.gov (United States)

    2011-07-27

    ... Electronic Fund Transfer Act (EFTA), as an example of money transfer instruments Federal credit unions (FCUs... receiving international and domestic electronic fund transfers'' after the words ``money orders'' from... checks, money orders, and other similar transfer instruments, including international and...

  7. Quadratic Variation by Markov Chains

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Horel, Guillaume

    We introduce a novel estimator of the quadratic variation that is based on the the- ory of Markov chains. The estimator is motivated by some general results concerning filtering contaminated semimartingales. Specifically, we show that filtering can in prin- ciple remove the effects of market...

  8. Spin Chains and Gustafson's Integrals

    CERN Document Server

    Derkachov, S E

    2016-01-01

    The Gustafson's integrals are the multidimensional generalization of the classical Mellin--Barnes integrals. We show that some of these integrals arise from relations between matrix elements in the Sklyanin's representation of Separated Variables in the spin chain models. We also present several new integrals.

  9. Concurrent Product & Supply Chain Creation

    DEFF Research Database (Denmark)

    Gubi, Ebbe

    it is a structural premise. We also know that logistics costs generally are estimated 15-20% of total product costs. Accordingly, it stands to reason that a company can reduce costs, and thereby gain an edge on its competitors, by tailoring the supply chain in question to an individual product or product family; i...

  10. Replicator dynamics in value chains

    DEFF Research Database (Denmark)

    Cantner, Uwe; Savin, Ivan; Vannuccini, Simone

    2016-01-01

    dynamics may revert its effect. In these regressive developments of market selection, firms with low fitness expand because of being integrated with highly fit partners, and the other way around; ii) allowing partner's switching within a value chain illustrates that periods of instability in the early...

  11. Maximal right smooth extension chains

    CERN Document Server

    Huang, Yun Bao

    2010-01-01

    If $w=u\\alpha$ for $\\alpha\\in \\Sigma=\\{1,2\\}$ and $u\\in \\Sigma^*$, then $w$ is said to be a \\textit{simple right extension}of $u$ and denoted by $u\\prec w$. Let $k$ be a positive integer and $P^k(\\epsilon)$ denote the set of all $C^\\infty$-words of height $k$. Set $u_{1},\\,u_{2},..., u_{m}\\in P^{k}(\\epsilon)$, if $u_{1}\\prec u_{2}\\prec ...\\prec u_{m}$ and there is no element $v$ of $P^{k}(\\epsilon)$ such that $v\\prec u_{1}\\text{or} u_{m}\\prec v$, then $u_{1}\\prec u_{2}\\prec...\\prec u_{m}$ is said to be a \\textit{maximal right smooth extension (MRSE) chains}of height $k$. In this paper, we show that \\textit{MRSE} chains of height $k$ constitutes a partition of smooth words of height $k$ and give the formula of the number of \\textit{MRSE} chains of height $k$ for each positive integer $k$. Moreover, since there exist the minimal height $h_1$ and maximal height $h_2$ of smooth words of length $n$ for each positive integer $n$, we find that \\textit{MRSE} chains of heights $h_1-1$ and $h_2+1$ are good candidates t...

  12. Towards biotracing in food chains

    DEFF Research Database (Denmark)

    Hoorfar, Jeffrey; Wagner, Martin; Jordan, Kieran

    2011-01-01

    , and 21 cross-disciplinary work packages that cover tracing and tracking of contamination in feed, meat and dairy chains, in addition to accidental and deliberate contamination of bottled water. The BIOTRACER Consortium consists of 46 partners, including Europe's largest food/feed industries, several SMEs...

  13. Supply Chain Simulation : A Survey

    NARCIS (Netherlands)

    Kleijnen, J.P.C.

    2003-01-01

    This paper provides a survey of simulation in supply chain management.It reviews four types of simulation, namely spreadsheet simulation, system dynamics, discreteevent simulation, and business games.Which simulation type should be applied, depends on the type of managerial question to be answered b

  14. Labour in Global Value Chains

    DEFF Research Database (Denmark)

    Lund-Thomsen, Peter; Nadvi, Khalid; Chan, Anita

    2012-01-01

    A critical challenge facing developing country producers is to meet international labour standards and codes of conduct in order to engage in global value chains. Evidence of gains for workers from compliance with such standards and codes remains limited and patchy. This article focuses on the gl......A critical challenge facing developing country producers is to meet international labour standards and codes of conduct in order to engage in global value chains. Evidence of gains for workers from compliance with such standards and codes remains limited and patchy. This article focuses...... on the global football industry, a sector dominated by leading global brands that manage dispersed global value chains. It assesses the working conditions for football stitchers engaged in different forms of work organization, factories, stitching centres and home-based settings in Pakistan, India and China...... production contexts that influence work conditions. In doing so, it argues that current debates on the role of labour in global value chains have to go beyond a narrow focus on labour standards and corporate social responsibility compliance and engage with economic, technological and social upgrading...

  15. A TCP/IP-based constant-bit-rate file transfer protocol and its extension to multipoint data delivery

    Energy Technology Data Exchange (ETDEWEB)

    Yamanaka, Kenjiro, E-mail: yamanaka@nii.ac.jp [National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo (Japan); Urushidani, Shigeo [National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo (Japan); Nakanishi, Hideya; Yamamoto, Takashi; Nagayama, Yoshio [National Institute of Fusion Science, 322-6 Orochi, Toki, Gifu (Japan)

    2014-05-15

    We present a new TCP/IP-based file transfer protocol which enables high-speed daisy-chain transfer. By using this protocol, we can send a file to a series of destination hosts simultaneously because intermediate hosts relay received file fragments to the next host. We achieved daisy-chain file transfer from Japan to Europe via USA at about 800 Mbps by using a prototype. The experimental result is also reported. A total link length of a data delivery network can be reduced by daisy chaining, so it enables cost-effective international data sharing.

  16. Fertilizer supply chain in Ethiopia: structure, performance and policy analysis

    Directory of Open Access Journals (Sweden)

    Johanes U.I. Agbahey

    2015-07-01

    Full Text Available In Ethiopia, less than 40% of farmers use fertilizer and those who do, apply rates significantly below those recommended. This low fertilizer use is primarily due to prices being two to three times higher than prices on the world markets. Reducing the price of fertilizer requires a sound understanding of the product´s supply chain. This study investigates whether fertilizer is delivered to farmers in an efficient way and at the lowest possible costs using an institutional economics framework. It was conducted in the Arsi zone and relied on secondary data as well as primary data collected through interviews. The findings point out the presence of several formal and informal institutions regulating the market. A market monopoly at each stage of the supply chain and a striking correspondence between the central organization of the chain and the rise in left-over stocks were observed. This pinpoints the imperfect structure of the chain and a misallocation of resources locked up in fertilizer stockholding. In order to improve the demand estimation procedure, this study suggests that incentives should be instituted to enhance the reliability of the information transferred along the process. Additionally, expert knowledge used in the process should be well documented, stock inventories should not be limited to central warehouses and stockholding needs to be reduced.

  17. Intercombination Effects in Resonant Energy Transfer

    CERN Document Server

    Vaillant, C L; Jones, M P A

    2015-01-01

    We investigate the effect of intercombination transitions in excitation hopping processes such as those found in F\\"orster resonance energy transfer. Taking strontium Rydberg states as our model system, the breakdown of $LS$-coupling leads to weakly allowed transitions between Rydberg states of different spin quantum number. We show that the long-range interactions between two Rydberg atoms can be affected by these weakly allowed spin transitions, and the effect is greatest when there is a near-degeneracy between the initial state and a state with a different spin quantum number. We also consider a case of four atoms in a spin chain, and show that a spin impurity can resonantly hop along the chain. By engineering the many-body energy levels of the spin-chain, the breakdown of $LS$ coupling due to inter-electronic effects in individual atoms can be mapped onto a spatial separation of the total spin and the total orbital angular momentum along the spin chain.

  18. Mechanism of Radical Transfer During Photoactivation of the flavoprotein DNA Photolyase

    Science.gov (United States)

    Lukacs, Andras; Vos, Marten H.; Eker, André P.; Byrdin, Martin; Brettel, Klaus

    Ultrafast transient absorption experiments on mutant DNA photolyase imply that radical transfer along a chain of tryptophan residues is substantially faster than the ˜30-ps photo-induced electron-transfer event initiated by excitation of the radical flavin FADH•.

  19. Calculating proper transfer prices

    Energy Technology Data Exchange (ETDEWEB)

    Dorkey, F.C. (Meliora Research Associates, Rochester, NY (United States)); Jarrell, G.A. (Univ. of Rochester, NY (United States))

    1991-01-01

    This article deals with developing a proper transfer pricing method. Decentralization is as American as baseball. While managers laud the widespread benefits of both decentralization and baseball, they often greet the term transfer price policy with a yawn. Since transfer prices are as critical to the success of decentralized firms as good pitchers are to baseball teams, this is quite a mistake on the part of our managers. A transfer price is the price charged to one division for a product or service that another division produced or provided. In many, perhaps most, decentralized organizations, the transfer pricing policies actually used are grossly inefficient and sacrifice the potential advantages of decentralization. Experience shows that far too many companies have transfer pricing policies that cost them significantly in foregone growth and profits.

  20. Waste Transfer Stations

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund

    2011-01-01

    tion and transport is usually the most costly part of any waste management system; and when waste is transported over a considerable distance or for a long time, transferring the waste from the collection vehicles to more efficient transportation may be economically beneficial. This involves...... a transfer station where the transfer takes place. These stations may also be accessible by private people, offering flexibility to the waste system, including facilities for bulky waste, household hazardous waste and recyclables. Waste transfer may also take place on the collection route from small...... satellite collection vehicles to large compacting vehicles that cannot effectively travel small streets and alleys within the inner city or in residential communities with narrow roads. However, mobile transfer is not dealt with in this chapter, which focuses on stationary transfer stations. This chapter...

  1. Supply chain challenges. building relationships.

    Science.gov (United States)

    Beth, Scott; Burt, David N; Copacino, William; Gopal, Chris; Lee, Hau L; Lynch, Robert Porter; Morris, Sandra

    2003-07-01

    Supply chain management is all about software and systems, right? Put in the best technology, sit back, and watch as your processes run smoothly and the savings roll in? Apparently not. When HBR convened a panel of leading thinkers in the field of supply chain management, technology was not top of mind. People and relationships were the dominant issues of the day. The opportunities and problems created by globalization, for example, are requiring companies to establish relationships with new types of suppliers. The ever-present pressure for speed and cost containment is making it even more important to break down stubbornly high internal barriers and establish more effective cross-functional relationships. The costs of failure have never been higher. The leading supply chain performers are applying new technology, new innovations, and process thinking to far greater advantage than the laggards, reaping tremendous gains in all the variables that affect shareholder value: cost, customer service, asset productivity, and revenue generation. And the gap between the leaders and the losers is growing in almost every industry. This roundtable gathered many of the leading thinkers and doers in the field of supply chain management, including practitioners Scott Beth of Intuit, Sandra Morris of Intel, and Chris Gopal of Unisys. David Burt of the University of San Diego and Stanford's Hau Lee bring the latest research from academia. Accenture's William Copacino and the Warren Company's Robert Porter Lynch offer the consultant's perspectives. Together, they take a wide-ranging view of such topics as developing talent, the role of the chief executive, and the latest technologies, exploring both the tactical and the strategic in the current state of supply chain management.

  2. Keypoint Transfer Segmentation

    OpenAIRE

    Wachinger, C.; Toews, M.; Langs, G.; Wells, W.; Golland, P.

    2015-01-01

    We present an image segmentation method that transfers label maps of entire organs from the training images to the novel image to be segmented. The transfer is based on sparse correspondences between keypoints that represent automatically identified distinctive image locations. Our segmentation algorithm consists of three steps: (i) keypoint matching, (ii) voting-based keypoint labeling, and (iii) keypoint-based probabilistic transfer of organ label maps. We introduce generative models for th...

  3. Wireless power transfer system

    OpenAIRE

    Arai, Hiroyuki

    2012-01-01

    This paper presents a survey of recent wireless power transfer systems. The issue of wireless power transfer is to achieve a highly efficient system with small positioning errors of the facilities setting. Several theories have been presented to obtain precise system design. This paper presents a summary of design theory for short range power transfer systems and detailed formulations based on a circuit model and an array of infinitesimal dipoles. In addition to these theories, this paper in...

  4. Strategic Transfer Pricing

    OpenAIRE

    Michael Alles; Srikant Datar

    1998-01-01

    Most research into cost systems has focused on their motivational implications. This paper takes a different approach, by developing a model where two oligopolistic firms strategically select their cost-based transfer prices. Duopoly models frequently assume that firms game on their choice of prices. Product prices, however, are ultimately based on the firms' transfer prices that communicate manufacturing costs to marketing departments. It is for this reason that transfer prices will have a s...

  5. Quench dynamics of two coupled zig-zag ion chains

    Science.gov (United States)

    Klumpp, Andrea; Liebchen, Benno; Schmelcher, Peter

    2016-08-01

    We explore the non-equilibrium dynamics of two coupled zig-zag chains of trapped ions in a double well potential. Following a quench of the potential barrier between both wells, the induced coupling between both chains due to the long-range interaction of the ions leads to the complete loss of order in the radial direction. The resulting dynamics is however not exclusively irregular but leads to phases of motion during which various ordered structures appear with ions arranged in arcs, lines and crosses. We quantify the emerging order by introducing a suitable measure and complement our analysis of the ion dynamics using a normal mode analysis showing a decisive population transfer between only a few distinguished modes.

  6. Technology transfers, foreign investment and productivity spillovers

    DEFF Research Database (Denmark)

    Newman, Carol; Rand, John; Talbot, Theodore Purdendu

    2015-01-01

    This paper explores the relationship between foreign direct investment (FDI) and the productivity of host country domestic firms. We rely on a specially designed survey of over 4000 manufacturing firms in Vietnam, and separate out productivity gains along the supply chain (obtained through direct...... transfers of knowledge/technology between linked firms) from productivity effects through indirect FDI spillovers. In addition to identifying indirect vertical productivity spillovers from FDI, our results show that there are productivity gains associated with direct linkages between foreign......-owned and domestic firms along the supply chain not captured by commonly used measures of spillovers. This includes evidence of productivity gains through forward linkages for domestic firms which receive inputs from foreign-owned firms....

  7. Basic heat transfer

    CERN Document Server

    Bacon, D H

    2013-01-01

    Basic Heat Transfer aims to help readers use a computer to solve heat transfer problems and to promote greater understanding by changing data values and observing the effects, which are necessary in design and optimization calculations.The book is concerned with applications including insulation and heating in buildings and pipes, temperature distributions in solids for steady state and transient conditions, the determination of surface heat transfer coefficients for convection in various situations, radiation heat transfer in grey body problems, the use of finned surfaces, and simple heat exc

  8. Supply Chain Management Practices in Toy Supply Chains

    DEFF Research Database (Denmark)

    Wong, Chee Yew; Arlbjørn, Jan Stentoft; Johansen, John

    2005-01-01

    qualitative semi-structured interviews and questionnaire with 11 main European toy retailers. Findings - The study concludes that there are three main SCM practices for toy retailers in terms of ordering behaviours (one-off, JIT, and mixed model), and one dominated SCM practice for toy manufacturers...... are required for such extreme volatility and seasonality are proposed. Originality/value - It reveals actual SCM practices in a volatile and seasonal supply chain, such that theoretical and practical gaps are identified. Also, it proposes a model to match manufacturing SCM-practices with retailer SCM-practices.......Purpose - Innovative products usually experience highly unpredictable and variable demand. This is especially valid for the volatile and seasonal toy industry, which produces high obsolete inventory, lost sales and markdown. In such a volatile industry, what supply chain management (SCM) practices...

  9. Supply Chain Management Performance in Tourism. Continental Hotels Chain Case

    OpenAIRE

    Gabriela Ţigu; Bogdan Călăreţu

    2013-01-01

    With its origins in logistics, Supply Chain Management (SCM) concept is covering all managerial aspects of the flow of materials and information from source to customer, across the entire range of materials handling and movement functions, and throughout an organization and its supply channels. In tourism, these issues relate to the whole process of providing tourism services from sourcing of raw materials, products or different services) to supply and distribution, and SCM performance can ul...

  10. chains

    Directory of Open Access Journals (Sweden)

    Gabriel Pérez-Salas

    2015-01-01

    Full Text Available Las barreras y aranceles al comercio exterior han disminuido significativamente gracias a los acuerdos multilaterales y los mecanismos de integración entre las naciones. Los costos logísticos representan una proporción significativa del precio final de los artículos, especialmente de los commodities. Por esta razón, minimizar los costos logísticos es un desafío importante para las naciones para fomentar la competitividad del comercio exterior y en particular para aprovechar la renta de los recursos naturales. En este artículo, proponemos un marco de referencia integral para la medición de costos logísticos, enfocado en determinar los extra-costos que resultan por procedimientos ineficientes y la falta de políticas públicas y regulaciones de las entidades públicas. Estos elementos no han sido considerados en la literatura, y este artículo aborda esta brecha. Como caso de estudio, presentamos la aplicación del marco de referencia para estimar los extra-costos en algunas cadenas logísticas de recursos naturales en Bolivia. Se presenta una discusión de los resultados encontrados, así como recomendaciones para trabajo futuro.

  11. Wave propagation in random granular chains.

    Science.gov (United States)

    Manjunath, Mohith; Awasthi, Amnaya P; Geubelle, Philippe H

    2012-03-01

    The influence of randomness on wave propagation in one-dimensional chains of spherical granular media is investigated. The interaction between the elastic spheres is modeled using the classical Hertzian contact law. Randomness is introduced in the discrete model using random distributions of particle mass, Young's modulus, or radius. Of particular interest in this study is the quantification of the attenuation in the amplitude of the impulse associated with various levels of randomness: two distinct regimes of decay are observed, characterized by an exponential or a power law, respectively. The responses are normalized to represent a vast array of material parameters and impact conditions. The virial theorem is applied to investigate the transfer from potential to kinetic energy components in the system for different levels of randomness. The level of attenuation in the two decay regimes is compared for the three different sources of randomness and it is found that randomness in radius leads to the maximum rate of decay in the exponential regime of wave propagation.

  12. Coupled transfers; Transferts couples

    Energy Technology Data Exchange (ETDEWEB)

    Nicolas, X.; Lauriat, G.; Jimenez-Rondan, J. [Universite de Marne-la-Vallee, Lab. d' Etudes des Transferts d' Energie et de Matiere (LETEM), 77 (France); Bouali, H.; Mezrhab, A. [Faculte des Sciences, Dept. de Physique, Lab. de Mecanique et Energetique, Oujda (Morocco); Abid, C. [Ecole Polytechnique Universitaire de Marseille, IUSTI UMR 6595, 13 Marseille (France); Stoian, M.; Rebay, M.; Lachi, M.; Padet, J. [Faculte des Sciences, Lab. de Thermomecanique, UTAP, 51 - Reims (France); Mladin, E.C. [Universitaire Polytechnique Bucarest, Faculte de Genie Mecanique, Bucarest (Romania); Mezrhab, A. [Faculte des Sciences, Lab. de Mecanique et Energetique, Dept. de Physique, Oujda (Morocco); Abid, C.; Papini, F. [Ecole Polytechnique, IUSTI, 13 - Marseille (France); Lorrette, C.; Goyheneche, J.M.; Boechat, C.; Pailler, R. [Laboratoire des Composites ThermoStructuraux, UMR 5801, 33 - Pessac (France); Ben Salah, M.; Askri, F.; Jemni, A.; Ben Nasrallah, S. [Ecole Nationale d' Ingenieurs de Monastir, Lab. d' Etudes des Systemes Thermiques et Energetiques (Tunisia); Grine, A.; Desmons, J.Y.; Harmand, S. [Laboratoire de Mecanique et d' Energetique, 59 - Valenciennes (France); Radenac, E.; Gressier, J.; Millan, P. [ONERA, 31 - Toulouse (France); Giovannini, A. [Institut de Mecanique des Fluides de Toulouse, 31 (France)

    2005-07-01

    This session about coupled transfers gathers 30 articles dealing with: numerical study of coupled heat transfers inside an alveolar wall; natural convection/radiant heat transfer coupling inside a plugged and ventilated chimney; finite-volume modeling of the convection-conduction coupling in non-stationary regime; numerical study of the natural convection/radiant heat transfer coupling inside a partitioned cavity; modeling of the thermal conductivity of textile reinforced composites: finite element homogenization on a full periodical pattern; application of the control volume method based on non-structured finite elements to the problems of axisymmetrical radiant heat transfers in any geometries; modeling of convective transfers in transient regime on a flat plate; a conservative method for the non-stationary coupling of aero-thermal engineering codes; measurement of coupled heat transfers (forced convection/radiant transfer) inside an horizontal duct; numerical simulation of the combustion of a water-oil emulsion droplet; numerical simulation study of heat and mass transfers inside a reactor for nano-powders synthesis; reduction of a combustion and heat transfer model of a direct injection diesel engine; modeling of heat transfers inside a knocking operated spark ignition engine; heat loss inside an internal combustion engine, thermodynamical and flamelet model, composition effects of CH{sub 4}H{sub 2} mixtures; experimental study and modeling of the evolution of a flame on a solid fuel; heat transfer for laminar subsonic jet of oxygen plasma impacting an obstacle; hydrogen transport through a A-Si:H layer submitted to an hydrogen plasma: temperature effects; thermal modeling of the CO{sub 2} laser welding of a magnesium alloy; radiant heat transfer inside a 3-D environment: application of the finite volume method in association with the CK model; optimization of the infrared baking of two types of powder paints; optimization of the emission power of an infrared

  13. Technology Transfer and Technology Transfer Intermediaries

    Science.gov (United States)

    Bauer, Stephen M.; Flagg, Jennifer L.

    2010-01-01

    A standard and comprehensive model is needed to evaluate and compare technology transfer systems and the stakeholders within these systems. The principle systems considered include federal laboratories, U.S. universities, the rehabilitation engineering research centers (RERCs), and large small business innovation research programs. An earlier…

  14. Q-operators for the open Heisenberg spin chain

    CERN Document Server

    Frassek, Rouven

    2015-01-01

    We construct Q-operators for the open spin-1/2 XXX Heisenberg spin chain with diagonal boundary matrices. The Q-operators are defined as traces over an infinite-dimensional auxiliary space involving novel types of reflection operators derived from the boundary Yang-Baxter equation. We argue that the Q-operators defined in this way are polynomials in the spectral parameter and show that they commute with transfer matrix. Finally, we prove that the Q-operators satisfy Baxter's TQ-equation.

  15. Q-operators for the open Heisenberg spin chain

    Directory of Open Access Journals (Sweden)

    Rouven Frassek

    2015-12-01

    Full Text Available We construct Q-operators for the open spin-12 XXX Heisenberg spin chain with diagonal boundary matrices. The Q-operators are defined as traces over an infinite-dimensional auxiliary space involving novel types of reflection operators derived from the boundary Yang–Baxter equation. We argue that the Q-operators defined in this way are polynomials in the spectral parameter and show that they commute with transfer matrix. Finally, we prove that the Q-operators satisfy Baxter's TQ-equation and derive the explicit form of their eigenvalues in terms of the Bethe roots.

  16. Automated polymerase chain reaction in capillary tubes with hot air.

    Science.gov (United States)

    Wittwer, C T; Fillmore, G C; Hillyard, D R

    1989-06-12

    We describe a simple, compact, inexpensive thermal cycler that can be used for the polymerase chain reaction. Based on heat transfer with air to samples in sealed capillary tubes, the apparatus resembles a recirculating hair dryer. The temperature is regulated via thermocouple input to a programmable set-point process controller that provides proportional output to a solid state relay controlling a heating coil. For efficient cooling after the denaturation step, the controller activates a solenoid that opens a door to vent hot air and allows cool air to enter. Temperature-time profiles and amplification results approximate those obtained using water baths and microfuge tubes.

  17. Q-operators for the open Heisenberg spin chain

    Science.gov (United States)

    Frassek, Rouven; Szécsényi, István M.

    2015-12-01

    We construct Q-operators for the open spin-1/2 XXX Heisenberg spin chain with diagonal boundary matrices. The Q-operators are defined as traces over an infinite-dimensional auxiliary space involving novel types of reflection operators derived from the boundary Yang-Baxter equation. We argue that the Q-operators defined in this way are polynomials in the spectral parameter and show that they commute with transfer matrix. Finally, we prove that the Q-operators satisfy Baxter's TQ-equation and derive the explicit form of their eigenvalues in terms of the Bethe roots.

  18. The fishing industry - toward supply chain modelling

    DEFF Research Database (Denmark)

    Jensen, Toke Koldborg; Nielsen, Jette; Larsen, Erling P.

    Mathematical models for simulating and optimizing supply chain aspects such as distribution planning and optimal use of raw materials are widely used. However, modelling based on a holistic chain view is less studied, and food-related aspects such as quality and shelf life issues enforce additional...... requirements onto the chains. In this paper, we consider the supply chain structure of the Danish fishing industry and illustrate the potential of using mathematical models to identify quality and value-adding activities. This is a first step toward innovative supply chain modelling aimed to identify benefits...... for actors along chains in the fishing industry....

  19. The chain relation in sofic subshifts

    CERN Document Server

    Kazda, Alexandr

    2009-01-01

    The paper gives a characterisation of the chain relation of a sofic subshift. Every sofic subshift $\\Sigma$ can be described by a labelled graph $G$. Factorising $G$ in a suitable way we obtain the graph $G/_\\approx$ that offers insight into some properties of the original subshift. Using $G/_\\approx$ we describe first the chain relation in $\\Sigma$, then characterise chain-transitive sofic subshifts, chain-mixing sofic subshifts and finally the attractors of the subshift dynamic system. At the end we present (straightforward) algorithms deciding chain-transitivity and chain-mixing properties of a sofic subshift and listing all the attractors of the subshift system.

  20. Quasilocal Conserved Operators in the Isotropic Heisenberg Spin-1/2 Chain.

    Science.gov (United States)

    Ilievski, Enej; Medenjak, Marko; Prosen, Tomaž

    2015-09-18

    Composing higher auxiliary-spin transfer matrices and their derivatives, we construct a family of quasilocal conserved operators of isotropic Heisenberg spin-1/2 chain and rigorously establish their linear independence from the well-known set of local conserved charges.

  1. Quasilocal Conserved Operators in the Isotropic Heisenberg Spin-1/2 Chain

    NARCIS (Netherlands)

    Ilievski, E.; Medenjak, M.; Prosen, T.

    2015-01-01

    Composing higher auxiliary-spin transfer matrices and their derivatives, we construct a family of quasilocal conserved operators of isotropic Heisenberg spin-1/2 chain and rigorously establish their linear independence from the well-known set of local conserved charges.

  2. Off-diagonal Bethe ansatz solution of the XXX spin-chain with arbitrary boundary conditions

    CERN Document Server

    Cao, Junpeng; Shi, Kangjie; Wang, Yupeng

    2013-01-01

    With the off-diagonal Bethe ansatz method proposed recently by the present authors, we exactly diagonalize the $XXX$ spin chain with arbitrary boundary fields. By constructing a functional relation between the eigenvalues of the transfer matrix and the quantum determinant, the associated $T-Q$ relation and the Bethe ansatz equations are derived.

  3. Off-diagonal Bethe ansatz solution of the XXX spin chain with arbitrary boundary conditions

    Science.gov (United States)

    Cao, Junpeng; Yang, Wen-Li; Shi, Kangjie; Wang, Yupeng

    2013-10-01

    Employing the off-diagonal Bethe ansatz method proposed recently by the present authors, we exactly diagonalize the XXX spin chain with arbitrary boundary fields. By constructing a functional relation between the eigenvalues of the transfer matrix and the quantum determinant, the associated T-Q relation and the Bethe ansatz equations are derived.

  4. VALUE CHAINS IN EMERGING MARKETS

    Directory of Open Access Journals (Sweden)

    Abdyramanova, Z.

    2016-11-01

    Full Text Available The textiles sector is one of the main industry sectors in Kyrgyzstan in terms of output, employment and increasingly exports. Textile clusters are developing and patterns in cluster formations are emerging that reflect the differing economic conditions of the regions, demonstrating particular influences on the value chain. These differences are both depicted in the two regions of Kyrgyzstan-south and north. In the north of the Republic the infrastructure is more developed, there is greater facility to access international markets (exports. In the south the infrastructure is less developed, and garment producers in the region serve mainly local niche and near-neighbour markets. The research objective is to assess the key drivers of the value chain and profitability in the textiles sector in Kyrgyzstan, by comparing the garment sewing sector in the two contrasting regions of south and north Kyrgyzstan.

  5. Formation of helical ion chains

    CERN Document Server

    Nigmatullin, Ramil; De Chiara, Gabriele; Morigi, Giovanna; Plenio, Martin B; Retzker, Alex

    2011-01-01

    We study the nonequilibrium dynamics of the linear to zigzag structural phase transition exhibited by an ion chain confined in a trap with periodic boundary conditions. The transition is driven by reducing the transverse confinement at a finite quench rate, which can be accurately controlled. This results in the formation of zigzag domains oriented along different transverse planes. The twists between different domains can be stabilized by the topology of the trap and under laser cooling the system relaxes to a helical chain with possibly nonzero winding number. Molecular dynamics simulations are used to obtain a large sample of possible trajectories for different quench rates. The scaling of the average winding number with different quench rates is compared to the prediction of the Kibble-Zurek theory, and a good quantitative agreement is found.

  6. Supply Chain Reorganization and Coordination

    Institute of Scientific and Technical Information of China (English)

    WANG Feng-bin

    2001-01-01

    Three generic forms of governance--hierarchy, hybrid and market are proposed in the newinstitutional economics, giving an abstract description of alternative coordination and control mechanisms forgeneral use. While this theory is known as far away from being operational and specified, a few researchersin the management and organization area are trying to extend Galbraith and/or Mintzberg's organizationaldesign theories into the application of logistical coordination for obtaining a smooth flow of products along thesupply chain within and without the focal organization. In this paper, we present an explorative case study onthe design of various organizational architectures of logistics activities and their relevant coordinationmechanisms, especially internal and external contracts as one new kind of hybrid mechanisms forcoordinating effective supply chains.

  7. Thermodynamic Model of Noise Information Transfer

    Science.gov (United States)

    Hejna, Bohdan

    2008-10-01

    In this paper we apply a certain unifying physical description of the results of Information Theory. Assuming that heat entropy is a thermodynamic realization of information entropy [2], we construct a cyclical, thermodynamic, average-value model of an information transfer chain [3] as a general heat engine, in particular a Carnot engine, reversible or irreversible. A working medium of the cycle (a thermodynamic system transforming input heat energy) can be considered as a thermodynamic, average-value model or, as such, as a realization of an information transfer channel. We show that in a model realized in this way the extended II. Principle of Thermodynamics is valid [2] and we formulate its information form.

  8. Technology transfer and learning

    NARCIS (Netherlands)

    Steenhuis, Harm-Jan; Bruijn, de Erik J.

    2002-01-01

    Despite the fact that international technology transfer has been widely studied its management still encounters many difficulties. To fully understand the issues that are relevant to the process of transferring production technology, it is necessary to determine the important factors that influence

  9. Mobilizing Sustainable Bioenergy Supply Chains

    OpenAIRE

    Baxter, David; Cowie, Annette; BERNDES Goran; Junginger, Martin; MCMILLAN James D; Saddler, J N; VAN REE Rene

    2015-01-01

    Analysis of the five globally significant supply chains conducted by IEA Bioenergy inter-Task teams – boreal and temperate forests, agricultural crop residues, biogas, lignocellulosic crops, and cultivated grasslands and pastures in Brazil – has confirmed that feedstocks produced using logistically efficient production systems can be mobilized to make significant contributions to achieving global targets for bioenergy. However, the very significant challenges identified in this report indi...

  10. China's Role in Purchasing Chain

    Institute of Scientific and Technical Information of China (English)

    Eva; Alice

    2007-01-01

    @@ In current world market,"Made-in-China"often means good price and competitive quality.In terms of China's trade pattern,more than half of Chinese exporting products belong to processing trade industry according to the demands and requirements of international orders.On the purchasing chain,China is learning from its international partners.Safety and quality always tops all issues.

  11. The dynamic chain event graph

    OpenAIRE

    2015-01-01

    In this paper we develop a formal dynamic version of Chain Event Graphs (CEGs), a particularly expressive family of discrete graphical models. We demonstrate how this class links to semi-Markov models and provides a convenient generalization of the Dynamic Bayesian Network (DBN). In particular we develop a repeating time-slice Dynamic CEG providing a useful and simpler model in this family. We demonstrate how the Dynamic CEG’s graphical formulation exhibits asymmetric conditional independence...

  12. On Markov Chains and Filtrations

    OpenAIRE

    1997-01-01

    In this paper we rederive some well known results for continuous time Markov processes that live on a finite state space.Martingale techniques are used throughout the paper. Special attention is paid to the construction of a continuous timeMarkov process, when we start from a discrete time Markov chain. The Markov property here holds with respect tofiltrations that need not be minimal.

  13. Modeling Continuous IED Supply Chains

    Science.gov (United States)

    2014-03-27

    criminals, pirates, drug traffickers and terrorists. Moreover, JIEDDO has pointed out the spread of IED use to places such as Thailand and Norway. U.S... human networks that place IEDs. Dekker categorizes two main human aspects of IED placement. The first is motivation which 8 affects the number of...methods provided in this thesis and apply them to combat other threats. For example, drug trafficking supply chains. IED and drug trafficking supply

  14. Supply-Chain Risk Analysis

    Science.gov (United States)

    2016-06-07

    Classic Buffer Overflow 1. http://cwe.mitre.org/top25/ SANS (SysAdmin, Audit, Network , Security ) Institute 23 Veracode: State of Software Security ...Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17...supply-chain risks. He participated in the design and development of the DHS Build- Security -In Web site and continues to contribute articles to it

  15. Synchronization Algorithms on Oriented Chains

    Directory of Open Access Journals (Sweden)

    D. Bein

    2008-01-01

    Full Text Available We present a space- and time-optimal self-stabilizing algorithm, SSDS, for a given synchronization problem on asynchronous oriented chains. SSDS is uniform and works under the unfair distributed daemon. From SSDS we derive solutions for the local mutual exclusion and distributed sorting. Algorithm SSDS can also be used to obtain optimal space solutions for other problems such as broadcasting, leader election, and mutual exclusion.

  16. Supply Chain Performance Evaluation: Trends and Challenges

    Directory of Open Access Journals (Sweden)

    Ezutah U. Olugu

    2009-01-01

    Full Text Available Problem statement: In today’s manufacturing world, globalization policies and rejuvenation have created a more intensive competition amongst manufacturers. On the other hand, manufacturers have turned to the option of adopting innovative technologies, process re-engineering and strategies such as efficient supply chain management to achieve a sustainable competitive advantage. Effective supply chain performance measurement has been identified as a key issue towards efficient supply chain management. To explore the extent of research in supply chain performance measurement and establish the gap in knowledge in supply chain performance measurement using fuzzy logic operation. Approach: Literatures in the area of supply chain performance measurement had been extensively reviewed. Both traditional and fuzzy logic approaches to supply chain performance measurement were scrutinized. Further scrutiny was carried out to establish potential research areas in the application of fuzzy logic operations in supply chain performance measurement. Results: The supply chain performance measurement using fuzzy logic operation was identified as a new direction in measuring the uncertainty and ambiguity surrounding supply chain performance measurement. Direction for further studies in the application of fuzzy logic operation in supply chain management and its performance measurement were also identified. Conclusion: Result of this study implied that there is still a gap in knowledge in the area of supply chain performance measurement. This new direction of studies involved extending the existing supply chains to incorporate product recovery after the useful life.

  17. Radiative heat transfer

    CERN Document Server

    Modest, Michael F

    2013-01-01

    The third edition of Radiative Heat Transfer describes the basic physics of radiation heat transfer. The book provides models, methodologies, and calculations essential in solving research problems in a variety of industries, including solar and nuclear energy, nanotechnology, biomedical, and environmental. Every chapter of Radiative Heat Transfer offers uncluttered nomenclature, numerous worked examples, and a large number of problems-many based on real world situations-making it ideal for classroom use as well as for self-study. The book's 24 chapters cover the four major areas in the field: surface properties; surface transport; properties of participating media; and transfer through participating media. Within each chapter, all analytical methods are developed in substantial detail, and a number of examples show how the developed relations may be applied to practical problems. It is an extensive solution manual for adopting instructors. Features: most complete text in the field of radiative heat transfer;...

  18. Engineering artificial redox chains by molecular 'Lego'.

    Science.gov (United States)

    Sadeghi, S J; Meharenna, Y T; Fantuzzi, A; Valetti, F; Gilardi, G

    2000-01-01

    This work reports on a novel approach for building artificial redox chains: the molecular 'Lego' approach. This exploits the scaffold of natural redox proteins by fusing together functional protein modules with the desired properties. The molecular 'Lego' mimics the natural molecular evolution that proceeded by modular assembly of genes/DNA segments. Non-physiological electron transfer partners, flavodoxin (fld) and cytochrome c553 (c553) from Desulfovibrio vulgaris and the haem domain of P450 BM3 (BMP) from Bacillus megaterium have been used as building blocks in different combinations to build artificial redox chains. The kinetic characterization of the electron transfer (ET) between the separate building blocks has been carried out. Under pseudo-first order conditions, a limiting ET rate, klim, of 0.48 +/- 0.05 s-1 and 43.77 +/- 2.18 s-1 and an apparent binding constant, Kapp, of 21 +/- 6 microM and 1.23 +/- 0.32 microM have been found for the fld/c553 and fld/BMP redox pairs, respectively. These results show that fld can be used as a module for transferring electrons to c553 and BMP. A 3D model of the fld/c553 and fld/BMP complexes was used to guide the construction of covalently linked assemblies via engineered disulfide bridges or by fusion of the relevant genes via an engineered loop. The first approach led to the construction, expression and characterization of the S35C and S64C mutants of fld and M23C and G51C mutants of c553. Although the redox potentials of the separate mutants were found to be the same as those of recombinant wild type proteins (-408 mV for the semiquinone/hydroquinone couple of fld and +32 mV for the c553), the c553 homo-dimers M23C-M23C and G51C-G51C were found to have redox potentials of +88 and +105 mV, respectively. These differences have been analysed in terms of exposure of the haem cofactors to the solvent, and these lead to some interesting questions on the redox potentials of the transient redox complexes in physiological

  19. ARCHITECTURAL CONCEPTS FOR VALUE CHAINS

    Directory of Open Access Journals (Sweden)

    A.C. Janse van Rensburg

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT:The Porter Value Chain has been widely adopted by the business community as a mechanism to understand and comprehend complexity in business environments, with the ultimate goal of structuring the business to maximize its competitive advantage. Implementing the Value Chain is not easy: a number of organizations can testify to their failure to derive any benefits at all from this concept. To overcome this problem, an approach is presented to assist the organization in creating a Value Chain reference model within the broader context of the organization’s enterprise architecture.

    AFRIKAANSE OPSOMMING: Die “Porter Waardeketting” is ’n algemene aanvaarde praktyk wat deur maatskappye gebruik word om die kompleksiteit van besigheidsomgewings mee te verstaan. Die uiteindelike doel hiervan is om die besigheid se mededings voordele te optimiseer. Om die Waardekettingkonsep te implementeer, is nie ’n maklike taak nie – verskeie organisasies kan getuig van mislukte implementeringspogings. Hierdie artikel beskryf ’n benadering beskryf wat gebruik kan word om die organisasie te help om ’n Waardekettingmodel te skep in die bree konteks van die organisasie se besigheidsargitektuur.

  20. Towards biotracing in food chains.

    Science.gov (United States)

    Hoorfar, Jeffrey; Wagner, Martin; Jordan, Kieran; Bouquin, Solveig Lind; Skiby, Jeffrey

    2011-03-01

    Biotracing is tracing (backward)/tracking (forward) biological contamination in the food/feed chain. Advances in detection technologies, improvements in molecular marker identification, clearer understanding of pathogenicity markers, improved modelling methodologies and, more importantly, the integration of these disciplines will lead to better capability in full-chain tracing and tracking biological contaminations (biotracing). The advantages of improved biotraceability are faster intervention, limited recalls and more targeted remedial action. The project is not dealing with risk assessments but developing tools that can be used in "second-generation" risk assessments involving quantitative microbiology. This concept is the core activity of BIOTRACER, which is an Integrated Project (2007-2011) funded by the EU 6th Framework Programme. The research in biotracing is organised into five Research Areas, and 21 cross-disciplinary work packages that cover tracing and tracking of contamination in feed, meat and dairy chains, in addition to accidental and deliberate contamination of bottled water. The BIOTRACER Consortium consists of 46 partners, including Europe's largest food/feed industries, several SMEs, and relevant International Cooperation (INCO) countries. The Consortium includes experts in predictive microbiology, database developers, software companies, risk assessors, risk managers, system biologists, food and molecular microbiologists, legislative officers, standardization and validation members and food retailers. The outcomes will ensure a more reliable and rapid response to a microbial contamination event.

  1. Technology Transfer Issues and a New Technology Transfer Model

    Science.gov (United States)

    Choi, Hee Jun

    2009-01-01

    The following are major issues that should be considered for efficient and effective technology transfer: conceptions of technology, technological activity and transfer, communication channels, factors affecting transfer, and models of transfer. In particular, a well-developed model of technology transfer could be used as a framework for…

  2. Cationic amphiphiles with fatty acyl chain asymmetry of coconut oil deliver genes selectively to mouse lung.

    Science.gov (United States)

    Chandrashekhar, Voshavar; Srujan, Marepally; Prabhakar, Rairala; Reddy, Rakesh C; Sreedhar, Bojja; Rentam, Kiran K R; Kanjilal, Sanjit; Chaudhuri, Arabinda

    2011-03-16

    Recent structure-activity studies have revealed a dramatic influence of hydrophobic chain asymmetry in enhancing gene delivery efficacies of synthetic cationic amphiphiles (Nantz, M. H. et al. Mol. Pharmaceutics2010, 7, 786-794; Koynova, R. et al. Mol. Pharmaceutics2009, 6, 951-958). The present findings demonstrate for the first time that such a transfection enhancing influence of asymmetric hydrocarbon chains observed in pure synthetic cationic amphiphiles also works for cationic amphiphiles designed with natural, asymmetric fatty acyl chains of a food-grade oil. Herein, we demonstrate that cationic amphiphiles designed with the natural fatty acyl chain asymmetry of food-grade coconut oil are less cytotoxic and deliver genes selectively to mouse lung. Despite lauroyl chains being the major fatty acyl chains of coconut oil, both the in vitro and In vivo gene transfer efficiencies of such cationic amphiphiles were found to be remarkably superior (>4-fold) to those of their pure dilauroyl analogue. Mechanistic studies involving the technique of fluorescence resonance energy transfer (FRET) revealed higher biomembrane fusibility of the cationic liposomes of the coconut amphiphiles than that of the symmetric dilauroyl analogue. AFM study revealed pronounced fusogenic nonlamellar structures of the liposomes of coconut amphiphiles. Findings in the FRET and cellular uptake study, taken together, support the notion that the higher cellular uptake resulting from the more fusogenic nature of the liposomes of coconut amphiphiles 1 are likely to play a dominant role in making the coconut amphiphiles transfection competent.

  3. Polymerization as a Model Chain Reaction

    Science.gov (United States)

    Morton, Maurice

    1973-01-01

    Describes the features of the free radical, anionic, and cationic mechanisms of chain addition polymerization. Indicates that the nature of chain reactions can be best taught through the study of macromolecules. (CC)

  4. Supply chain strategies, issues and models

    CERN Document Server

    Ramanathan, Ramakrishnan

    2014-01-01

    In the 21st century, supply chain operations and relationships among supply chain partners have become highly challenging, necessitating new approaches, e.g., the development of new models. Supply Chain Strategies, Issues and Models discusses supply chain issues and models with examples from actual industrial cases. Expert authors with a wide spectrum of knowledge working in various areas of supply chain management from various geographical locations offer refreshing, novel and insightful ideas and address possible solutions using established theories and models. Supply Chain Strategies, Issues and Models features studies that have used mathematical modeling, statistical analyses and also descriptive qualitative studies. The chapters cover many relevant themes related to supply chains and logistics including supply chain complexity, information sharing, quality (six sigma), electronic Kanbans, inventory models, scheduling, purchasing and contracts. To facilitate easy reading, the chapters that deal with suppl...

  5. SUPPLY CHAIN MANAGEMENT – KEY FACTORS

    Directory of Open Access Journals (Sweden)

    Magdalena Daniela DINU

    2014-06-01

    Full Text Available This paper exposes Supply Chain Management by its key factors. Briefly, where the Supply Chain Management is treated as strategic part of a company then maintaining both control and influence throughout the entire supply chain are key factors and critical to success. On the other hand, finding the right partner to manage the non-strategic Supply Chains would be another key factor too. To define the most important key factors within Supply Chain Management means a deeply understanding of both Supply Chain’ s components, procedures, workflow, processes and the importance of Supply Chain Management into maximizing company's value. SCORE model able to provide solid information about measuring performance and identifying priorities within Supply Chain Management will help us to understand the key factors by analyzing its elements: Plan, Source, Make, Deliver,Return, Enable. These elements covers all the challenging areas from first to third tier of Supply Chain Management.

  6. Information flow in the pharmaceutical supply chain.

    Science.gov (United States)

    Yousefi, Nazila; Alibabaei, Ahmad

    2015-01-01

    Managing the supply chain plays an important role in creating competitive advantages for companies. Adequate information flow in supply chain is one of the most important issues in SCM. Therefore, using certain Information Systems can have a significant role in managing and integrating data and information within the supply chain. Pharmaceutical supply chain is more complex than many other supply chains, in the sense that it can affect social and political perspectives. On the other hand, managing the pharmaceutical supply chain is difficult because of its complexity and also government regulations in this field. Although, Iran has progressed a lot in pharmaceutical manufacturing, still there are many unsolved issues in managing the information flow in the pharmaceutical supply chain. In this study, we reviewed the benefits of using different levels of an integrated information system in the supply chain and the possible challenges ahead.

  7. BUSINESS TENDENCIES IN SERVICES WITHIN SUPPLY CHAIN

    OpenAIRE

    Beata Skowron-Grabowska

    2008-01-01

    Supply chain management has been a major component of competitive strategy to enhance organizational productivity and profitability. Client satisfaction and improvement in profitability are two basic goals while organizing supply chain. In the paper author tried to prove that there is a correlation between organization of supply chain and subjective evaluation of economic situation by enterprises. Logistics integration helps enterprises to find their place in the supply chain.

  8. Supply Chain Integration: Challenges and Solutions

    OpenAIRE

    Sweeney, Edward

    2011-01-01

    Rapid changes in technological development are forcing businesses to continuously innovate to improve their competitiveness, which is particularly evident in logistics and supply chain management (SCM), where innovation impacts both the strategic and operational levels. Supply Chain Innovation for Competing in Highly Dynamic Markets: Challenges and Solutions investigates the role of innovation in the management of supply chains of today. This book focuses on supply chain integration from both...

  9. Australian Lamb Supply Chain: A Conceptual Framework

    OpenAIRE

    Jie, Ferry

    2011-01-01

    In the last decade, supply chain management has played an important role to lead agribusiness today to succeed in their business goals, to gain competitive advantages, and to improve business performance. As the result of that, there has been extensive studying in a popular topic of strategic supply chain management in order to improve business performance as well as along supply chain performance under the real situation. This is because in current business world, supply chain practices are ...

  10. Knowledge transfer isn’t simply transfer

    DEFF Research Database (Denmark)

    Dao, Li; Napier, Nancy

    2012-01-01

    This paper examines micro dynamic aspects of knowledge sharing and learning in international joint venture settings. Learning of expatriate and local managers appears far more complex and mutually dependent than conventionally speculated in existing literature. The paper proposes that the effect...... and outcome of knowledge transfer from joint venture parents and learning in IJVs are dependent on how individual managers (including both expatriate and local) learn, perceive their learning roles, and enact a learning agenda. Empirical evidence is drawn from two cases of international joint ventures between...... Danish and Vietnamese firms. The paper suggests that learning in IJVs, even in the context of one-way knowledge transfer from the foreign parent, should be managed in a mutual perspective and with thoughtful coordination of individual learning....

  11. Turbulent Characteristic of Liquid Around a Chain of Bubbles in Non-Newtonian Fluid

    Institute of Scientific and Technical Information of China (English)

    李少白; 马友光; 朱春英; 付涛涛; 李怀志

    2012-01-01

    The turbulence behavior of gas-liquid two-phase flow plays an important role in heat transfer and mass transfer in many chemical processes. In this work, a 2D particle image velocimetry (PIV) was used to investigate the turbulent characteristic of fluid induced by a chain of bubbles rising in Newtonian and non-Newtonian fluids. The instantaneous flow field, turbulent kinetic energy (TKE) and TKE dissipation rate were measured. The results demonstrated that the TKE profiles were almost symmetrical along the column center and showed higher values in the central region of the column. The TKE was enhanced with the increase of gas flow and decrease of liquid viscosity. The maximum TKE dissipation rate appeared on both sides of the bubble chain, and increased with the increase of gas flow rate or liquid viscosity. These results provide an understanding for gas-liquid mass transfer in non-Newtonian fluids.

  12. Open spin chains with generic integrable boundaries: Baxter equation and Bethe ansatz completeness from SOV

    CERN Document Server

    Kitanine, N; Niccoli, G

    2014-01-01

    We solve the longstanding problem to define a functional characterization of the spectrum of the transfer matrix associated to the most general spin-1/2 representations of the 6-vertex reflection algebra for general inhomogeneous chains. The corresponding homogeneous limit reproduces the spectrum of the Hamiltonian of the spin-1/2 open XXZ and XXX quantum chains with the most general integrable boundaries. The spectrum is characterized by a second order finite difference functional equation of Baxter type with an inhomogeneous term which vanishes only for some special but yet interesting non-diagonal boundary conditions. This functional equation is shown to be equivalent to the known separation of variable (SOV) representation hence proving that it defines a complete characterization of the transfer matrix spectrum. The polynomial character of the Q-function allows us then to show that a finite system of equations of generalized Bethe type can be similarly used to describe the complete transfer matrix spectru...

  13. Technology transfer 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-01-01

    This document, Technology Transfer 94, is intended to communicate that there are many opportunities available to US industry and academic institutions to work with DOE and its laboratories and facilities in the vital activity of improving technology transfer to meet national needs. It has seven major sections: Introduction, Technology Transfer Activities, Access to Laboratories and Facilities, Laboratories and Facilities, DOE Office, Technologies, and an Index. Technology Transfer Activities highlights DOE`s recent developments in technology transfer and describes plans for the future. Access to Laboratories and Facilities describes the many avenues for cooperative interaction between DOE laboratories or facilities and industry, academia, and other government agencies. Laboratories and Facilities profiles the DOE laboratories and facilities involved in technology transfer and presents information on their missions, programs, expertise, facilities, and equipment, along with data on whom to contact for additional information on technology transfer. DOE Offices summarizes the major research and development programs within DOE. It also contains information on how to access DOE scientific and technical information. Technologies provides descriptions of some of the new technologies developed at DOE laboratories and facilities.

  14. 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.

  15. Visualisation for System Learning in Supply Chains

    Science.gov (United States)

    Lindskog, Magnus; Abrahamsson, Mats; Aronsson, Hakan

    2007-01-01

    Contemporary supply chains are vastly complex, and decisions made by actors have system-wide consequences that these might not be able to foresee. There are gaps between "best practice"-founded theory and actual practice in supply chains. To remedy this, we argue, the supply chain actors need to enhance systems knowledge. There is a need to…

  16. Learning to Integrate: Supply Chains Reconceptualised

    Science.gov (United States)

    Sense, Andrew J.; Clements, Michael D. J.

    2007-01-01

    This paper introduces and explains a conception of supply chains from a situated learning perspective. This non-conventional supply chain perspective invites the reader to consider supply chain scenarios as "situated learning opportunities involving multiple communities of practice" interacting and participating together. It is argued that by…

  17. Cellular chain formation in Escherichia coli biofilms

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk; Klemm, Per

    2009-01-01

    In this study we report on a novel structural phenotype in Escherichia coli biofilms: cellular chain formation. Biofilm chaining in E. coli K-12 was found to occur primarily by clonal expansion, but was not due to filamentous growth. Rather, chain formation was the result of intercellular...

  18. A concept for collaborative supply chain planning

    DEFF Research Database (Denmark)

    Alfnes, E.; Dreyer, H.C.; Hvolby, Hans-Henrik

    2012-01-01

    vendors such as Oracle, SAP and I2 offer supply chain planning systems. This limits the ability for SMEs to exploit the supply chain planning options. This paper is part of a research project carried out to develop a new supply chain add-on for Microsoft AX, a very common system for SMEs. The paper...

  19. The Advancement Value Chain: An Exploratory Model

    Science.gov (United States)

    Leonard, Edward F., III

    2005-01-01

    Since the introduction of the value chain concept in 1985, several varying, yet virtually similar, value chains have been developed for the business enterprise. Shifting to higher education, can a value chain be found that links together the various activities of advancement so that an institution's leaders can actually look at the philanthropic…

  20. Secure Supply Chains: Design Restrictions & Organizational Boundaries

    NARCIS (Netherlands)

    Ludema, M.W.

    2009-01-01

    An important issue in the design of secure supply chains is the understanding of the relation between supply chains and the organizational responsibility of specific parts of these supply chains. Organizational boundaries change over time by means of vertical and/or horizontal (des)-integration and

  1. On a Result for Finite Markov Chains

    Science.gov (United States)

    Kulathinal, Sangita; Ghosh, Lagnojita

    2006-01-01

    In an undergraduate course on stochastic processes, Markov chains are discussed in great detail. Textbooks on stochastic processes provide interesting properties of finite Markov chains. This note discusses one such property regarding the number of steps in which a state is reachable or accessible from another state in a finite Markov chain with M…

  2. Compressing redundant information in Markov chains

    OpenAIRE

    2006-01-01

    Given a strongly stationary Markov chain and a finite set of stopping rules, we prove the existence of a polynomial algorithm which projects the Markov chain onto a minimal Markov chain without redundant information. Markov complexity is hence defined and tested on some classical problems.

  3. STATISTICS OF A CLASS OF MARKOV CHAINS

    Institute of Scientific and Technical Information of China (English)

    DENG Yingchun; CAO Xianbing

    2004-01-01

    In this paper we prove that the distributions of their sojourn time and hitting time at one special state for random walks which are allowed to be finite or infinite and Markov chains on star-graphs with discrete time can uniquely determine the probability distribution of the whole chains. This result also suggests a new statistical method for Markov chains.

  4. Consistency and Refinement for Interval Markov Chains

    DEFF Research Database (Denmark)

    Delahaye, Benoit; Larsen, Kim Guldstrand; Legay, Axel;

    2012-01-01

    Interval Markov Chains (IMC), or Markov Chains with probability intervals in the transition matrix, are the base of a classic specification theory for probabilistic systems [18]. The standard semantics of IMCs assigns to a specification the set of all Markov Chains that satisfy its interval...

  5. Chains versus Independents: Newspaper and Market Characteristics.

    Science.gov (United States)

    Hale, F. Dennis

    A study examined the marketing differences between large chain newspapers and small chain and independent newspapers by analyzing differences in characteristics of the newspapers, patterns of circulation, economic and social conditions of the market, and competition from other print media. The 200 newspapers studied--113 large chain and 87 small…

  6. Principles in Halal Supply Chain Management

    NARCIS (Netherlands)

    Tieman, H.; Vorst, van der J.G.A.J.; Maznah Che Ghazali,

    2012-01-01

    Purpose – The purpose of this paper is to introduce a new framework to optimise the design of halal food supply chains, called the “Halal Supply Chain Model”. In this research the main logistics business processes are defined, which are the determinants for the halal supply chain performance. Design

  7. Systematic Methodology of Integrated Supply Chain Management

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Supply chain management (SCM) is a strategy for global competition. Th e characteristics of SCM are integration, systematic and coordination. Using sys tematic, coordination thoughts and integration theory, a new model of enterprise integration based on supply chain management is put forward and an implementing paradigm for systematic methodology of supply chain management is developed.

  8. Experiences with the Mango Chain Game

    NARCIS (Netherlands)

    Meijer, S.A.; Zuñiga-Arias, G.; Sterrenburg, S.

    2005-01-01

    The mango chain game is a simulation game used for research purposes. It facilitated studying the bargaining power of Costa Rican mango producers in international supply chains of mango. The game simulates a simplified mango export chain in which real world local producers can play the role of produ

  9. Review of Published Chain Information System Research

    NARCIS (Netherlands)

    Storer, C.E.; Trienekens, J.H.; Beulens, A.J.M.; Quaddus, M.A.

    2006-01-01

    This paper provides a review of the literature on chains and networks that examine interorganisational information systems used to manage chains of organisations. Difficulty was found in finding out how organisations exchanged information to manage relationships with customers and suppliers in chain

  10. Transfer Matrix Method for Natural Vibration Analysis of Tree System

    Directory of Open Access Journals (Sweden)

    Bin He

    2012-01-01

    Full Text Available The application of Transfer matrix method (TMM ranges from linear/nonlinear vibration, composite structure, and multibody system to calculating static deformation, natural vibration, dynamical response, and damage identification. Generally TMM has two characteristics: (1 the TMM formulae share similarity to the chain mechanics model in terms of topology structure; then TMM often is selected as a powerful tool to analyze the chain system. (2 TMM is adopted to deal with the problems of the discrete system, continuous system, and especial discrete/continuous coupling system with the uniform matrix form. In this investigation, a novel TMM is proposed to analyze the natural vibration of the tree system. In order to make the TMM of the tree system have the two above advantages of the TMM of the chain system, the suitable state vectors and transfer matrices of the typical components of the tree system are constructed. Then the topology comparability between the mechanics model and its corresponding formulae of TMM can be adopted to assembling the transfer matrices and transfer equations of the global tree system. Two examples of natural vibration problems validating the method are given. The formulation of the proposed TMM is mathematically intuitive and can be held and applied by the engineers easily.

  11. A heat transfer textbook

    CERN Document Server

    Lienhard, John H

    2011-01-01

    This introduction to heat transfer offers advanced undergraduate and graduate engineering students a solid foundation in the subjects of conduction, convection, radiation, and phase-change, in addition to the related topic of mass transfer. A staple of engineering courses around the world for more than three decades, it has been revised and updated regularly by the authors, a pair of recognized experts in the field. The text addresses the implications, limitations, and meanings of many aspects of heat transfer, connecting the subject to its real-world applications and developing students' ins

  12. Effective Bayesian Transfer Learning

    Science.gov (United States)

    2010-03-01

    class •!Classes: llama , deer, horse, giraffe, elephant, anteater •!Transferred knowledge: •!Location of keypoints (landmarks) •!Variability of...keypoints TL7 Raw Curves for deer- llama One class to another class Transfer No Transfer TL7 Raw Curves for pairs One class to another class Deer...Elephant Deer-Horse Deer-Giraffe Deer- Llama Giraffe-Deer Elephant-Deer Llama -Deer Horse-Deer TL7 Average Curve for deer- llama One class to another

  13. Supply Chain Management Performance in Tourism. Continental Hotels Chain Case

    Directory of Open Access Journals (Sweden)

    Gabriela Ţigu

    2013-02-01

    Full Text Available With its origins in logistics, Supply Chain Management (SCM concept is covering all managerial aspects of the flow of materials and information from source to customer, across the entire range of materials handling and movement functions, and throughout an organization and its supply channels. In tourism, these issues relate to the whole process of providing tourism services from sourcing of raw materials, products or different services to supply and distribution, and SCM performance can ultimately be measured by customer satisfaction. Thus, an important component of tourism SCM is the demand management. Therefore, this study aims to highlight the features of the concept of SCM and demand management in tourism, with an emphasis on a hotel chain in Romania, based on research and analysis of tourist traffic indicators as well as assessment of customers satisfaction. The sources of information are the internal company statistics, as well as various hotels booking websites that offer customers’ feedback. The results of the study provide a snapshot of how the hotel demand management can influence SCM performance in tourism.

  14. Probabilistic accident consequence uncertainty analysis: Food chain uncertainty assessment. Volume 2: Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J. [National Radiological Protection Board (United Kingdom); Goossens, L.H.J.; Kraan, B.C.P. [Delft Univ. of Technology (Netherlands)] [and others

    1997-06-01

    This volume is the second of a two-volume document that summarizes a joint project by the US Nuclear Regulatory and the Commission of European Communities to assess uncertainties in the MACCS and COSYMA probabilistic accident consequence codes. These codes were developed primarily for estimating the risks presented by nuclear reactors based on postulated frequencies and magnitudes of potential accidents. This two-volume report, which examines mechanisms and uncertainties of transfer through the food chain, is the first in a series of five such reports. A panel of sixteen experts was formed to compile credible and traceable uncertainty distributions for food chain transfer that affect calculations of offsite radiological consequences. Seven of the experts reported on transfer into the food chain through soil and plants, nine reported on transfer via food products from animals, and two reported on both. The expert judgment elicitation procedure and its outcomes are described in these volumes. This volume contains seven appendices. Appendix A presents a brief discussion of the MAACS and COSYMA model codes. Appendix B is the structure document and elicitation questionnaire for the expert panel on soils and plants. Appendix C presents the rationales and responses of each of the members of the soils and plants expert panel. Appendix D is the structure document and elicitation questionnaire for the expert panel on animal transfer. The rationales and responses of each of the experts on animal transfer are given in Appendix E. Brief biographies of the food chain expert panel members are provided in Appendix F. Aggregated results of expert responses are presented in graph format in Appendix G.

  15. Transport Properties in a One-Dimensional Chain with Randomly Side-Coupled Impurities

    Institute of Scientific and Technical Information of China (English)

    胡冬生; 张桂平; 熊诗杰

    2002-01-01

    We investigate the transport properties of a one-dimensional (1D) chain with randomly side-coupled impurities.By using the transfer matrix technique, we present numerical results of the transmission coefficient as a function of the electron energy. It is found that an extended state will be shown in such a random 1D system if the impurities are side-coupled to the chain with not only the nearest-neighbour bonds but also the next-nearest-neighbour bonds. We present an analytical expression for the energy of this extended state, which is determined by the strength of the nearest and next-nearest couplings between the impurities and the chain. The obtained results can be used to explain the transport properties of DNA chains and other quasi-lD organic structures.

  16. The influence of power in supply chain innovation; a case study of the Dutch wheat chain

    NARCIS (Netherlands)

    Pol, Hanneke; Visscher, Klaasjan

    2010-01-01

    The purpose of this article is to clarify the relation between the power structure of a supply chain and the possibilities to realize supply chain innovations. In an in-depth case study of the faltering start of an innovation trajectory in the Dutch wheat supply chain, we show that supply chain inno

  17. Functional Bethe ansatz methods for the open XXX chain

    Energy Technology Data Exchange (ETDEWEB)

    Frahm, Holger; Grelik, Jan H; Seel, Alexander; Wirth, Tobias, E-mail: Holger.Frahm@itp.uni-hannover.d, E-mail: Jan.Grelik@itp.uni-hannover.d, E-mail: Alexander.Seel@itp.uni-hannover.d [Institut fuer Theoretische Physik, Leibniz Universitaet Hannover, Appelstr. 2, 30167 Hannover (Germany)

    2011-01-07

    We study the spectrum of the integrable open XXX Heisenberg spin chain subject to non-diagonal boundary magnetic fields. The spectral problem for this model can be formulated in terms of functional equations obtained by separation of variables or, equivalently, from the fusion of transfer matrices. For generic boundary conditions the eigenvalues cannot be obtained from the solution of finitely many algebraic Bethe equations. Based on careful finite size studies of the analytic properties of the underlying hierarchy of transfer matrices we devise two approaches to analyze the functional equations. First we introduce a truncation method leading to Bethe-type equations determining the energy spectrum of the spin chain. In a second approach, the hierarchy of functional equations is mapped to an infinite system of nonlinear integral equations of TBA type. The two schemes have complementary ranges of applicability and facilitate an efficient numerical analysis for a wide range of boundary parameters. Some data are presented on the finite-size corrections to the energy of the state which evolves into the antiferromagnetic ground state in the limit of parallel boundary fields.

  18. Supply chain management - safety aspects

    Directory of Open Access Journals (Sweden)

    2010-12-01

    Full Text Available Developing economy, growing customer requirements and competition make the service level higher. Delivery safety - as the highest priority - has to be maintained at the same time. Customers more and more often require transport to be very flexible, fast, and complex in terms of carrying every quantity of goods of different sizes, from and to different countries, through customs clearance, storing and distribution of shipments. Meeting these requirements depends on complex information on transport processes and their safety. The article presents safety foundations and institution Authorized Economic Operator - AEO in supply chains.

  19. TBA for the Toda chain

    Energy Technology Data Exchange (ETDEWEB)

    Kozlowski, K.K.; Teschner, J.

    2010-06-15

    We give a direct derivation of a proposal of Nekrasov-Shatashvili concerning the quantization conditions of the Toda chain. The quantization conditions are formulated in terms of solutions to a nonlinear integral equation similar to the ones coming from the thermodynamic Bethe ansatz. This is equivalent to extremizing a certain function called Yang's potential. It is shown that the Nekrasov-Shatashvili formulation of the quantization conditions follows from the solution theory of the Baxter equation, suggesting that this way of formulating the quantization conditions should indeed be applicable to large classes of quantized algebraically integrable models. (orig.)

  20. MODELING SUPPLY CHAIN WITH SIMULATION

    OpenAIRE

    János Benkõ

    2010-01-01

    Supply Chain Management faces a lot of challenging issues involving difficult decisions which can be company-oriented and customer-oriented issues. In this study we deal with customeroriented issues. For example, a customer’s demand may not be fully satisfied from stock on hand and the shortage may be backordered or the sale may be lost. Either way, it is desirable to balance the holding cost which depends on the magnitude of inventory against the cost of not fully satisfying customer demand....

  1. Heat transport in coupled inhomogeneous chains

    Institute of Scientific and Technical Information of China (English)

    Hu Tao; Bai Meng; Hu Ke; Tang Yi

    2011-01-01

    We first investigate the heat transport in a network model consisting of two coupled dimerized chains. Results indicate that the thermal resistance of each chain increases with the decrease of the mass ratio γ of the two types of atoms. Then, we find, when a light impurity or a heavy one is added in the two coupled homogeneous chains and coupled with a particle of another chain, the interface thermal resistances Rlint andRγint present different dependences on the mass ratio γ'. Finally, a persistent circulation of energy current is observed in coupled inhomogeneous chains with two pairs of interchain coupling.

  2. Integration of Forestry Industrial Chain in China

    Institute of Scientific and Technical Information of China (English)

    Zhanzhan; LAN; Liqun; WANG

    2013-01-01

    Based on the Smile Curve and Michael E. Porter’ value chain model,this paper points out that China’s forestry industry stays at the low end of the value chain for a long time. Raw materials are imported from foreign countries and also sold in foreign countries. Then,the authors analyze characteristics and existing problems of China’s forestry industrial chain. They put forward the development direction of China’s forestry industrial chain with reference to International Paper Company. Finally,they present their recommendations for integration of China’s forestry industrial chain.

  3. Uncertainty quantification for Markov chain models.

    Science.gov (United States)

    Meidani, Hadi; Ghanem, Roger

    2012-12-01

    Transition probabilities serve to parameterize Markov chains and control their evolution and associated decisions and controls. Uncertainties in these parameters can be associated with inherent fluctuations in the medium through which a chain evolves, or with insufficient data such that the inferential value of the chain is jeopardized. The behavior of Markov chains associated with such uncertainties is described using a probabilistic model for the transition matrices. The principle of maximum entropy is used to characterize the probability measure of the transition rates. The formalism is demonstrated on a Markov chain describing the spread of disease, and a number of quantities of interest, pertaining to different aspects of decision-making, are investigated.

  4. Mississippi Technology Transfer Center

    Science.gov (United States)

    1987-01-01

    The Mississippi Technology Transfer Center at the John C. Stennis Space Center in Hancock County, Miss., was officially dedicated in 1987. The center is home to several state agencies as well as the Center For Higher Learning.

  5. Condensation heat transfer

    Science.gov (United States)

    Rose, J. W.

    The paper gives a brief description of some of the better understood aspects of condensation heat transfer and includes discussion of the liquid-vapour interface, natural and forced convection laminar film condensation and dropwise condensation.

  6. Controlled Environment Specimen Transfer

    DEFF Research Database (Denmark)

    Damsgaard, Christian Danvad; Zandbergen, Henny W.; Hansen, Thomas Willum

    2014-01-01

    an environmental transmission electron microscope to an in situ X-ray diffractometer through a dedicated transmission electron microscope specimen transfer holder, capable of sealing the specimen in a gaseous environment at elevated temperatures. Two catalyst material systems have been investigated; Cu/ZnO/Al2O3...... transferred in a reactive environment to the environmental transmission electron microscope where further analysis on the local scale were conducted. The Co/Al2O3 catalyst was reduced in the environmental microscope and successfully kept reduced outside the microscope in a reactive environment. The in situ......Specimen transfer under controlled environment conditions, such as temperature, pressure, and gas composition, is necessary to conduct successive complementary in situ characterization of materials sensitive to ambient conditions. The in situ transfer concept is introduced by linking...

  7. Technology transfer for adaptation

    Science.gov (United States)

    Biagini, Bonizella; Kuhl, Laura; Gallagher, Kelly Sims; Ortiz, Claudia

    2014-09-01

    Technology alone will not be able to solve adaptation challenges, but it is likely to play an important role. As a result of the role of technology in adaptation and the importance of international collaboration for climate change, technology transfer for adaptation is a critical but understudied issue. Through an analysis of Global Environment Facility-managed adaptation projects, we find there is significantly more technology transfer occurring in adaptation projects than might be expected given the pessimistic rhetoric surrounding technology transfer for adaptation. Most projects focused on demonstration and early deployment/niche formation for existing technologies rather than earlier stages of innovation, which is understandable considering the pilot nature of the projects. Key challenges for the transfer process, including technology selection and appropriateness under climate change, markets and access to technology, and diffusion strategies are discussed in more detail.

  8. Digitized Heat Transfer

    Science.gov (United States)

    Mohseni, Kamran; Young, Patrick

    2007-11-01

    This presentation presents theoretical and numerical results describing digitized heat transfer (DHT), an active thermal management technique for high-power electronics and integrated micro systems. In digitized heat transfer discrete droplets are employed. The internal flow inside a discrete droplet is dominated by internal circulation imposed by the boundaries. This internal circulation imposes a new timescale for recirculating cold liquid from the middle of the droplet to the boundary. This internal circulation produces periodic oscillation in the overall convective heat transfer rate. Numerical simulations are presented for heat transfer in the droplet for both constant temperature and flux boundary conditions. The effectiveness of DHT for managing both localized temperature spikes and steady state cooling is demonstrated, identifying key parameters for optimization of the DHT method.

  9. Liquefied Natural Gas Transfer

    Science.gov (United States)

    1980-01-01

    Chicago Bridge & Iron Company's tanks and associated piping are parts of system for transferring liquefied natural gas from ship to shore and storing it. LNG is a "cryogenic" fluid meaning that it must be contained and transferred at very low temperatures, about 260 degrees below Fahrenheit. Before the LNG can be pumped from the ship to the storage tanks, the two foot diameter transfer pipes must be cooled in order to avoid difficulties associated with sharp differences of temperature between the supercold fluid and relatively warm pipes. Cooldown is accomplished by sending small steady flow of the cryogenic substance through the pipeline; the rate of flow must be precisely controlled or the transfer line will be subjected to undesirable thermal stress.

  10. Multiscale photosynthetic exciton transfer

    CERN Document Server

    Ringsmuth, A K; Stace, T M; 10.1038/nphys2332

    2012-01-01

    Photosynthetic light harvesting provides a natural blueprint for bioengineered and biomimetic solar energy and light detection technologies. Recent evidence suggests some individual light harvesting protein complexes (LHCs) and LHC subunits efficiently transfer excitons towards chemical reaction centers (RCs) via an interplay between excitonic quantum coherence, resonant protein vibrations, and thermal decoherence. The role of coherence in vivo is unclear however, where excitons are transferred through multi-LHC/RC aggregates over distances typically large compared with intra-LHC scales. Here we assess the possibility of long-range coherent transfer in a simple chromophore network with disordered site and transfer coupling energies. Through renormalization we find that, surprisingly, decoherence is diminished at larger scales, and long-range coherence is facilitated by chromophoric clustering. Conversely, static disorder in the site energies grows with length scale, forcing localization. Our results suggest s...

  11. Electron transfer in proteins

    DEFF Research Database (Denmark)

    Farver, O; Pecht, I

    1991-01-01

    Electron migration between and within proteins is one of the most prevalent forms of biological energy conversion processes. Electron transfer reactions take place between active centers such as transition metal ions or organic cofactors over considerable distances at fast rates and with remarkable...... specificity. The electron transfer is attained through weak electronic interaction between the active sites, so that considerable research efforts are centered on resolving the factors that control the rates of long-distance electron transfer reactions in proteins. These factors include (in addition......-containing proteins. These proteins serve almost exclusively in electron transfer reactions, and as it turns out, their metal coordination sites are endowed with properties uniquely optimized for their function....

  12. Theories Supporting Transfer of Training.

    Science.gov (United States)

    Yamnill, Siriporn; McLean, Gary N.

    2001-01-01

    Reviews theories about factors affecting the transfer of training, including theories on motivation (expectancy, equity, goal setting), training transfer design (identical elements, principle, near and far), and transfer climate (organizational). (Contains 36 references.) (SK)

  13. Convection heat transfer

    CERN Document Server

    Bejan, Adrian

    2013-01-01

    Written by an internationally recognized authority on heat transfer and thermodynamics, this second edition of Convection Heat Transfer contains new and updated problems and examples reflecting real-world research and applications, including heat exchanger design. Teaching not only structure but also technique, the book begins with the simplest problem solving method (scale analysis), and moves on to progressively more advanced and exact methods (integral method, self similarity, asymptotic behavior). A solutions manual is available for all problems and exercises.

  14. Principles of tendon transfers.

    Science.gov (United States)

    Coulet, B

    2016-04-01

    Tendon transfers are carried out to restore functional deficits by rerouting the remaining intact muscles. Transfers are highly attractive in the context of hand surgery because of the possibility of restoring the patient's ability to grip. In palsy cases, tendon transfers are only used when a neurological procedure is contraindicated or has failed. The strategy used to restore function follows a common set of principles, no matter the nature of the deficit. The first step is to clearly distinguish between deficient muscles and muscles that could be transferred. Next, the type of palsy will dictate the scope of the program and the complexity of the gripping movements that can be restored. Based on this reasoning, a surgical strategy that matches the means (transferable muscles) with the objectives (functions to restore) will be established and clearly explained to the patient. Every paralyzed hand can be described using three parameters. 1) Deficient segments: wrist, thumb and long fingers; 2) mechanical performance of muscles groups being revived: high energy-wrist extension and finger flexion that require strong transfers with long excursion; low energy-wrist flexion and finger extension movements that are less demanding mechanically, because they can be accomplished through gravity alone in some cases; 3) condition of the two primary motors in the hand: extrinsics (flexors and extensors) and intrinsics (facilitator). No matter the type of palsy, the transfer surgery follows the same technical principles: exposure, release, fixation, tensioning and rehabilitation. By performing an in-depth analysis of each case and by following strict technical principles, tendon transfer surgery leads to reproducible results; this allows the surgeon to establish clear objectives for the patient preoperatively.

  15. Insights into the Ecotoxicity of Silver Nanoparticles Transferred from Escherichia coli to Caenorhabditis elegans

    Science.gov (United States)

    Luo, Xun; Xu, Shengmin; Yang, Yaning; Li, Luzhi; Chen, Shaopeng; Xu, An; Wu, Lijun

    2016-11-01

    Previous studies have indicated that engineered nanomaterials can be transferred through the food chain. However, their potential ecotoxicity to the environment is not fully understood. Here, we systematically evaluated the physiological behavior and toxicity of polyvinylpyrrolidone (PVP)-coated silver nanoparticles (AgNPs) using a food chain model from Escherichia coli (E. coli) to Caenorhabditis elegans (C. elegans). Our results demonstrated that AgNPs accumulated in E. coli could be transferred to the C. elegans, and AgNPs were clearly distributed in the gut lumen, subcutaneous tissue and gonad. After being transferred to C. elegans through the food chain, the accumulated AgNPs caused serious toxicity to the higher trophic level (C. elegans), including effects on germ cell death, reproductive integrity and life span. Relative to larger particles (75 nm), small AgNPs (25 nm) more easily accumulated in the food chain and exhibited a stronger toxicity to the higher trophic level. More importantly, both the AgNPs that had accumulated in C. elegans through the food chain and the resulting impairment of germ cells could be transferred to the next generation, indicating that AgNP can cause genetic damage across generations. Our findings highlight that nanomaterials pose potential ecotoxicity to ecosystems via transport through the food chain.

  16. ALICE tests its digital chain

    CERN Multimedia

    2007-01-01

    During its 7th data challenge, ALICE successfully tested the infrastructure of its data acquisition, transfer and storage system. The ALICE experiment will need a rock-solid data acquisition, selection, transfer, storage and handling system to analyse the billions of bits of data that will be generated every second. The heavy ion collisions at the LHC will generate 10 times more data per second than proton collisions. The ALICE teams have therefore been hard at it for several years designing a cutting-edge informatics system, whose reliability is regularly put to the test in the annual data challenges. Last December, groups from the Collaboration and the IT Department joined forces, or rather cables, in the 7th of these challenges. The teams of ALICE DAQ (data acquisition), ALICE Offline (data handling), IT-CS-IO (network) and IT-FIO (CASTOR and data storage) all took part in testing the various components of the infrastructure, from data acquisition to transfer and storage. Working in close collaboration,...

  17. Elastic Energy Transfer in Turbulence of Dilute Polymer Solution

    Science.gov (United States)

    Xi, Heng-Dong; Bodenschatz, Eberhard; Xu, Haitao

    2012-11-01

    We present an experimental study of the energy transfer in the bulk of a turbulent flow with small amount long-chain polymer additives. By varying the Reynolds numbers Rλ, Wissenberg number Wi and polymer concentration φ. We test quantitively the elastic theory proposed by de Gennes and Tabor (Europhys. Lett., 1986; Physica A, 1986). The rate of energy transfer by polymer elasticity as inferred from the theory is consistent with that measured from the second order Eulerian structure functions. The unknown parameter n in the theory, which represents the flow topology of the stretching field, is found to be nearly 1. Based on energy transfer rate balance, We propose an elastic length scale, rɛ, which describes the effect of polymer elasticity on turbulence energy cascade and captures the scale dependence of the elastic energy transfer rate. We are grateful to the Max Planck Society, the Alexander von Humboldt Foundation and the Deutsche Forschungsgemeinschaft for their support.

  18. Synchronization of Synchrotrons for bunch-to-bucket Transfers

    CERN Document Server

    Ferrand, Thibault; Damerau, Heiko; CERN. Geneva. ATS Department

    2015-01-01

    To reach high particle energies with synchrotrons, a chain of several accelerators is required, as the ratio of extraction and injection energy is in the range of 10 to 20 per synchrotron. Hence the beam must be transfered from one accelerator to the next one. This document deals with the bunch-to-bucket transfer method to inject particle bunches composing the beam from a source synchrotron to a target synchrotron. After we highlight the theoretical concept of the bunch-to-bucket transfer, we determine physical limitations due to the beam dynamics and the adiabatic aspect of the particle bunches. A summary of the currently performed bunch-to-bucket transfer scenarios between the accelerators at CERN is given and set in relation with the mentioned theoretical concepts.

  19. Successful synchronization of the LHC's clockwise beam transfer system

    CERN Multimedia

    2008-01-01

    LHC synchronization test successful The synchronization of the LHC's clockwise beam transfer system and the rest of CERN's accelerator chain was successfully achieved last weekend. Tests began on Friday 8 August when a single bunch of a few particles was taken down the transfer line from the SPS accelerator to the LHC. After a period of optimization, one bunch was kicked up from the transfer line into the LHC beam pipe and steered about 3 kilometres around the LHC itself on the first attempt. On Saturday, the test was repeated several times to optimize the transfer before the operations group handed the machine back for hardware commissioning to resume on Sunday. The anti-clockwise synchronization systems will be tested over the weekend of 22 August.

  20. The fish industry - toward supply chain modelling

    DEFF Research Database (Denmark)

    Jensen, Toke Koldborg; Nielsen, Jette; Larsen, Erling

    2010-01-01

    Mathematical models for simulating and optimizing aspects of supply chains such as distribution, planning, and optimal handling of raw materials are widely used. However, modeling based on a holistic chain view including several or all supply chain agents is less studied, and food-related aspects...... such as quality and shelf-life issues enforce additional requirements onto the chains. In this article, we consider the supply chain structure of the fish industry. We discuss and illustrate the potential of using mathematical models to identify quality and value-adding activities. The article provides a first...... step toward innovative supply chain modeling aimed to identify benefits for all agents along chains in the fish industry....