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Sample records for atrp macroinitiator approach

  1. Fluorinated bio-acceptable polymers via an ATRP macroinitiator approach

    DEFF Research Database (Denmark)

    Hansen, Natanya Majbritt Louie; Haddletion, D.M.; Hvilsted, Søren

    2007-01-01

    Polymers derived from bio-acceptable poly(methyl methacrylate) (PMMA), poly(2-methoxyethyl acrylate) (PMEA), and poly(oligo(ethylene glycol) methyl ether methacrylate) (PPEGMA) have been prepared via atom transfer radical polymerization (ATRP) utilizing an initiator prepared from a fluoroalkoxy......-bromoisobutyrate. The initiator generally also serves as an internal plasticizer lowering the glass transition temperature from the parent polymers. The surface characteristics of the fluoroinitiator containing polymers are altered compared with the nonfluorinated analogues. This is reflected in a significant...

  2. Synthesis of α-Bromine- Terminated Polystyrene Macroinitiator and Its Initiation of MMA Polymerization by ATRP

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In the present paper the synthesis of block copolymers via the transformation from living anionic polymerization (LAP) to atom transfer radical polymerization (ATRP) was described. Α-Bromine-terminated polystyrenes(PStBr) in the LAP step was prepared by using n-BuLi as initiator, tetrahydrofuran (THF) as the activator, α-methylstyrene (α-MeSt) as the capping group and liquid bromine (Br2) as the bromating agent. The effects of reaction conditions such as the amounts of α-MeSt, THF, and Br2 as well as molecular weight of polystyrene on the bromating efficiency (BE) and coupling extent (CE) were examined. The present results show that the yield of PStBr obtained was more than 93.8% and the coupling reaction was substantially absent. PStBr was further used as the macroinitiator in the polymerization of methyl-methacrylate(MMA) in the presence of copper(Ⅰ) halogen and 2,2-bipyridine(bpy) complexes. It was found that the molecular weight of the resulted PSt-b-PMMA increased linearly with the increase of the conversion of MMA and the polydispersity was 1.2-1.6. The structures of PStBr and P(St-b-MMA) were characterized by 1H NMR spectra.

  3. Amplification of surface-initiated ring-opening metathesis polymerization of 5-(perfluoro-n-alkyl)norbornenes by macroinitiation.

    Science.gov (United States)

    Escobar, Carlos A; Harl, Robert R; Maxwell, Kathryn E; Mahfuz, Nur N; Rogers, Bridget R; Jennings, G Kane

    2013-10-01

    This article reports the enhanced rate of the surface-initiated polymerization (SIP) of 5-(perfluoro-n-alkyl)norbornenes (NBFn) by combining two SIP techniques, namely surface-initiated atom-transfer polymerization (SI-ATRP) to grow a macroinitiator and surface-initiated ring-opening metathesis polymerization (SI-ROMP) to produce the final coating. This polymerization approach promotes the rapid growth of dense partially fluorinated coatings that are highly hydrophobic and oleophobic and yield thicknesses from 4-12 μm. Specifically, the growth rate and the limiting thickness of pNBFn with different side chain lengths (n = 4, 6, 8, and 10) at various monomer concentrations and temperatures are evaluated through two approaches: growing the polymer from an initiator-terminated monolayer (control) or from a modified poly(2-hydroxyethyl methacrylate) (PHEMA) macroinitiator. X-ray photoelectron spectroscopy (XPS) analysis shows that 38% of the hydroxyl termini in the macroinitiator react with a norbornenyl diacid chloride (NBDAC) molecule, and 7% of such anchored norbornenyl groups react with a catalyst molecule. The kinetic data have been modeled to determine the propagation velocity and the termination rate constant. The PHEMA macroinitiator provides thicker films and faster growth as compared to the monolayer, achieving a 12 μm thick coating of pNBF8 in 15 min. Increasing the monomer side chain length, n, from 4 to 10 improves the growth rate and the limiting polymer thickness. Performing the polymerization process at higher temperature increases the growth rate and the limiting thickness as evidenced by an increase in the film growth rate constant. Arrhenius plots show that the reactions involved in the macroinitiation process exhibit lower activation energies than those formed from a monolayer. Electrochemical impedance spectroscopy reveals that the films exhibit resistance against ion transport in excess of 1 × 10(10) Ω·cm(2). PMID:24024903

  4. Preparation of well-defined polystyrene/silica hybrid nanoparticles by ATRP

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Immobilization of the atom transfer radical polymerization (ATRP) macroinitiators at the silica nanoparticle surfaces was achieved through surface modification with excess toluene-2,4-diisocynate (TDI), after which the residual isocyanate groups were converted into ATRP macroinitiators. Structurally well-defined polystyrene chains were grown from the nanoparticle surfaces to yield individual particles composed of a silica core and a well-defined, densely grafted outer polystyrene by ATRP, which was initiated by the as-synthesized silica-based macroinitiator. FTIR, NMR and gel permeation chro-matography (GPC) were used to characterize the polystyrene/silica hybrid particles.

  5. Preparation of well-defined polystyrene/silica hybrid nanoparticles by ATRP

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Immobilization of the atom transfer radical polymerization(ATRP)macroinitiators at the silica nanoparticle surfaces was achieved through surface modification with excess toluene-2,4-diisocynate(TDI),after which the residual isocyanate groups were converted into ATRP macroinitiators.Structurally well-defined polystyrene chains were grown from the nanoparticle surfaces to yield individual particles composed of a silica core and a well-defined,densely grafted outer polystyrene by ATRP,which was initiated by the as-synthesized silica-based macroinitiator.FTIR,NMR and gel permeation chromatography(GPC)were used to characterize the polystyrene/silica hybrid particles.

  6. AGET ATRP of acrylonitrile with ionic liquids as reaction medium without any additional ligand

    International Nuclear Information System (INIS)

    Atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) was carried out for the first time in 1-methylimidazolium acetate ([mim][AT]), 1-methylimidazolium propionate([mim][PT]), and 1-methylimidazolium butyrate ([mim][BT]), respectively. The polymerization was approached by using ascorbic acid (VC) as a reducing agent, ethyl 2-bromoisobutyrate (EBiB) as initiator, only FeBr3 as catalyst without any additional ligand. Kinetic studies showed that both AGET ATRP of AN in the absence of oxygen and in the presence of air proceeded in a well-controlled manner. Under the same conditions, the polymerization in the presence of air provided rather slower reaction rate and showed better control of molecular weight and its distribution than in the absence of oxygen. The sequence of the apparent polymerization rate constants of AGET ATRP of AN in three ionic liquids was kapp([mim][AT]) > kapp([mim][PT]) > kapp([mim][BT]). The living nature of the polymerization was confirmed by chain end analysis and block copolymerization of methyl methacrylate with polyacrylonitrile as macroinitiator. All the three ionic liquids and FeBr3 could be recycled and reused and had no effect on the living nature of polymerization.

  7. AGET ATRP of acrylonitrile with ionic liquids as reaction medium without any additional ligand

    Energy Technology Data Exchange (ETDEWEB)

    Chen Hou, E-mail: lduchenhou@hotmail.com [School of Chemistry and Materials Science, Ludong University, Yantai 264025 (China); Liang Ying; Liu Delong; Tan Zhi; Zhang Shaohong; Zheng Meiling; Qu Rongjun [School of Chemistry and Materials Science, Ludong University, Yantai 264025 (China)

    2010-05-10

    Atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) was carried out for the first time in 1-methylimidazolium acetate ([mim][AT]), 1-methylimidazolium propionate([mim][PT]), and 1-methylimidazolium butyrate ([mim][BT]), respectively. The polymerization was approached by using ascorbic acid (VC) as a reducing agent, ethyl 2-bromoisobutyrate (EBiB) as initiator, only FeBr{sub 3} as catalyst without any additional ligand. Kinetic studies showed that both AGET ATRP of AN in the absence of oxygen and in the presence of air proceeded in a well-controlled manner. Under the same conditions, the polymerization in the presence of air provided rather slower reaction rate and showed better control of molecular weight and its distribution than in the absence of oxygen. The sequence of the apparent polymerization rate constants of AGET ATRP of AN in three ionic liquids was k{sub app}([mim][AT]) > k{sub app}([mim][PT]) > k{sub app}([mim][BT]). The living nature of the polymerization was confirmed by chain end analysis and block copolymerization of methyl methacrylate with polyacrylonitrile as macroinitiator. All the three ionic liquids and FeBr{sub 3} could be recycled and reused and had no effect on the living nature of polymerization.

  8. Synthesis of novel glycopolymer brushes via a combination of RAFT-mediated polymerisation and ATRP

    Directory of Open Access Journals (Sweden)

    Eric T.A. van den Dungen

    2011-03-01

    Full Text Available Glycopolymers (synthetic sugar-containing polymers have become increasingly attractive to polymer chemists because of their role as biomimetic analogues and their potential for commercial applications. Glycopolymers of different structures confer high hydrophilicity and water solubility and can therefore be used for specialised applications, such as artificial materials for a number of biological, pharmaceutical and biomedical uses. The synthesis and characterisation of a series of novel glycopolymer brushes, namely poly(2-(2-bromoisobutyryloxy ethyl methacrylate-g-poly(methyl 6-O-methacryloyl-α-D-glucoside (P(BIEM-g-P(6-O-MMAGIc, poly(2-(2-bromoisobutyryloxy ethyl methacrylate-co-methyl methacrylate-g-poly(methyl 6-O-methacryloyl-α-D-glucoside P(BIEM-co-MMA-g-P(6-O-MMAGIc, poly(2-(2-bromoisobutyryloxy ethyl methacrylate-b-methyl methacrylate-g-poly(methyl 6-O-methacryloyl-α-D-glucoside P(BIEM-b-MMA-g-P(6-O-MMAGIc and poly(4-vinylbenzyl chloride-alt-maleic anhydride-g-poly(methyl 6-O-methacryloyl-α-D-glucoside (P(Sd-alt-MAnh-g-P(6-O-MMAGIc are described in this paper. Reversible addition-fragmentation chain transfer (RAFT-mediated polymerisation was used to synthesise four well-defined atom transfer radical polymerisation (ATRP macroinitiators (the backbone of the glycopolymer brushes. These ATRP macroinitiators were subsequently used in the ‘grafting from’ approach (in which side chains are grown from the backbone to prepare high molar mass and low polydispersity index glycopolymer brushes with different grafting densities along the backbone. The number average molar mass of the glycopolymer brushes was determined using size exclusion chromatography with a multi-angle laser light

  9. Star polymers by ATRP of styrene and acrylates employing multifunctional initiators

    DEFF Research Database (Denmark)

    Jankova, Katja Atanassova; Bednarek, Melania; Hvilsted, Søren

    2005-01-01

    Multifunctional initiators for atom transfer radical polymerization (ATRP) are prepared by converting ditrimethylolpropane with four hydroxyl groups, dipentaerythritol with six hydroxyl groups, and poly(3-ethyl-3-hydroxymethyl-oxetane) with similar to 11 hydroxyl groups to the corresponding 2......-bromoisobutyrates or 2-bromopropionates as obtained by reaction with acid bromides. Star polystyrene (PS) is produced by using these macroinitiators and neat styrene in a controlled manner by ATRP at 110 degrees C, employing the catalytic system CuBr and bipyridine. M. up to 51,000 associated with narrow molecular...

  10. Grafting polyacrylates from carbohydrates by ATRP and formation of nanoparticles for advanced drug delivery

    OpenAIRE

    Hirosue, Masayuki

    2010-01-01

    The present thesis describes synthesis and characterization of graft copolymers from carbohydrates and formulation of nanoparticles(NP)s for drug carrier application. Side chains were produced grafting from carbohydrate based macroinitiators via Atom Transfer Radical Polymerization (ATRP). Firstly, hydrophobic homo-, random- and block-copolymer side chains were grafted from a beta-Cyclodextrin core, followed by starch as a core. Monomer conversions up to 80% were achieved in most cases and we...

  11. Synthesis and characterization of a novel water-soluble cationic diblock copolymer with star conformation by ATRP

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shuzhao [Department of Chemical Engineering, University of New Brunswick, Fredericton, NB E3B 5A3 (Canada); School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Xiao, Miaomiao [Department of Chemical Engineering, University of New Brunswick, Fredericton, NB E3B 5A3 (Canada); Zheng, Anna [School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Xiao, Huining, E-mail: hxiao@unb.ca [Department of Chemical Engineering, University of New Brunswick, Fredericton, NB E3B 5A3 (Canada)

    2014-10-01

    A water-soluble cationic diblock copolymer, CD-PAM-b-PMeDMA, was synthesized through atom transfer radical polymerization (ATRP) from a β-cyclodextrin (CD) macroinitiator with 10-active sites (10Br-β-CD). In order to reduce the cytotoxicity of the CD-PAM-b-PMeDMA, biocompatible polyacrylamide (PAM) was first introduced onto the surface of β-CD as a scaffold structure by ATRP using the 10Br-β-CD as a macroinitiator. The reaction conditions of AM were explored and optimized. The ATRP of [2-(methacryloyloxy)ethyl] trimethyl ammonium chloride (MeDMA) was also performed to synthesize the second cationic block using the resulting CD-PAM as a macroinitiator. The resulting diblock copolymer shows an increased hydrodynamic radius in aqueous solution with a pretty low concentration compared with β-CD. In addition, it appears a near-uniform coniform after being deposited on mica ascribed to the presence of an asymmetric 10-arm structure. - Highlights: • A 10-arm diblock polymer was prepared by ATRP for the potential use as a non-viral gene delivery. • PAM was first synthesized in a controlled manner considering its biocompatibility. • The hydrodynamic radius of the copolymer in aqueous solution increase to 130 nm from 7.5 nm of CD. • The copolymer appears coniform after deposited on mica surface due to the charge attraction.

  12. Synthesis of Fluorinated Amphiphilic Block Copolymers Based on PEGMA, HEMA, and MMA via ATRP and CuAAC Click Chemistry

    OpenAIRE

    Fatime Eren Erol; Deniz Sinirlioglu; Sedat Cosgun; Ali Ekrem Muftuoglu

    2014-01-01

    Synthesis of fluorinated amphiphilic block copolymers via atom transfer radical polymerization (ATRP) and Cu(I) catalyzed Huisgen 1,3-dipolar cycloaddition (CuAAC) was demonstrated. First, a PEGMA and MMA based block copolymer carrying multiple side-chain acetylene moieties on the hydrophobic segment for postfunctionalization was carried out. This involves the synthesis of a series of P(HEMA-co-MMA) random copolymers to be employed as macroinitiators in the controlled synthesis of P(HEMA-co-M...

  13. New highly fluorinated styrene-based materials with low surface energy prepared by ATRP

    DEFF Research Database (Denmark)

    Borkar, Sachin; Jankova Atanasova, Katja; Siesler, Heinz W; Hvilsted, Søren

    2004-01-01

    radical polymerization (ATRP) at 110 degreesC to high conversions in relatively short times, 10-120 min; TF(F-5)S is additionally polymerized at 70 and 90 degreesC. Block copolymers with styrene are prepared by the macroinitiator approach. All polymers, in the number-average molecular weight range from...... 6000 to 35 000, have polydispersity indexes between 1.08 and 1.37. The homopolymers show glass transitions from 16 to 62 degreesC depending on molecular weight, whereas the block copolymers exhibit phase separation mirrored in two T(g)s, which could be observed when the smallest block constitutes more...... than 10 mol %. The fluorinated side chains of P(TF(F-5)S) and P(TF(F-15)S) enrich the surface of thin films, which results in an advancing water contact angle of 117degrees and 122degrees, respectively. Both XPS analyses and contact angle measurements strongly imply that the fluorinated parts of the...

  14. Synthesis by ATRP of poly(ethylene-co-butylene)-block-polystyrene, poly(ethylene-co-butylene)-block-poly(4-acetoxystyrene) and its hydrolysis product poly(ethylene-co-butylene)-block-poly(hydroxystyrene)

    DEFF Research Database (Denmark)

    Jankova, Katja; Kops, Jørgen; Chen, Xianyi;

    1999-01-01

    Diblock copolymers of poly(ethylene-co-butylene) and polystyrene or poly(4-acetoxystyrene) are synthesized by atom transfer radical polymerization (ATRP) using a 2-bromopropionic ester macroinitiator prepared from commercial monohydroxyl functional narrow dispersity hydrogenated polybutadiene...... copolymer with poly(4-acetoxystyrene) was hydrolyzed to the corresponding poly(4-hydroxystyrene) sequence....

  15. PNIPAAm-grafted thermoresponsive microcarriers: Surface-initiated ATRP synthesis and characterization

    International Nuclear Information System (INIS)

    In this study, we developed novel thermoresponsive microcarriers as a powerful tool for cell culture and tissue engineering applications. For this purpose, two types of commercially available spherical microparticles (approximately 100 μm in diameter), dextran-based Sephadex® and vinyl acetate-based VA-OH (Biosynth®), were used and themoresponsive poly(N-isopropylacrylamide) (PNIPAAm) was grafted to the beads' surfaces by surface-initiated atom transfer radical polymerization (SI-ATRP). Initially, hydroxyl groups of microbeads were reacted with 2-bromopropionyl bromide to form ATRP macroinitiator. Then, NIPAAm was successfully polymerized from the initiator attached microbeads by ATRP with CuBr/2,2′-dipyridyl, catalyst complex. Furthermore, grafted and ungrafted microbeads were characterized by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, scanning electron microscope (SEM), atomic force microscopy (AFM) and electron spectroscopy for chemical analysis (ESCA). The results of characterization studies confirmed that PNIPAAm was successfully grafted onto both dextran and vinyl acetate-based beads by means of ATRP reaction and thus, grafted microbeads gained thermoresponsive characteristics which will be evaluated for cell harvesting in further studies. Highlights: • PNIPAAm was grafted to the hydroxyl group carrying polymer beads by SI-ATRP. • Dex-g-PNIPAAm and VA-OH-g-PNIPAAm beads exhibited thermoresponsive characteristics. They are appropriate candidates for microcarrier-facilitated cell cultures

  16. PNIPAAm-grafted thermoresponsive microcarriers: Surface-initiated ATRP synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Çakmak, Soner [Nanotechnology and Nanomedicine Department, Hacettepe University, 06800, Beytepe, Ankara (Turkey); Çakmak, Anıl S. [Bioengineering Department, Hacettepe University, 06800, Beytepe, Ankara (Turkey); Gümüşderelioğlu, Menemşe, E-mail: menemse@hacettepe.edu.tr [Nanotechnology and Nanomedicine Department, Hacettepe University, 06800, Beytepe, Ankara (Turkey); Bioengineering Department, Hacettepe University, 06800, Beytepe, Ankara (Turkey); Chemical Engineering Department, Hacettepe University, 06800, Beytepe, Ankara (Turkey)

    2013-07-01

    In this study, we developed novel thermoresponsive microcarriers as a powerful tool for cell culture and tissue engineering applications. For this purpose, two types of commercially available spherical microparticles (approximately 100 μm in diameter), dextran-based Sephadex® and vinyl acetate-based VA-OH (Biosynth®), were used and themoresponsive poly(N-isopropylacrylamide) (PNIPAAm) was grafted to the beads' surfaces by surface-initiated atom transfer radical polymerization (SI-ATRP). Initially, hydroxyl groups of microbeads were reacted with 2-bromopropionyl bromide to form ATRP macroinitiator. Then, NIPAAm was successfully polymerized from the initiator attached microbeads by ATRP with CuBr/2,2′-dipyridyl, catalyst complex. Furthermore, grafted and ungrafted microbeads were characterized by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, scanning electron microscope (SEM), atomic force microscopy (AFM) and electron spectroscopy for chemical analysis (ESCA). The results of characterization studies confirmed that PNIPAAm was successfully grafted onto both dextran and vinyl acetate-based beads by means of ATRP reaction and thus, grafted microbeads gained thermoresponsive characteristics which will be evaluated for cell harvesting in further studies. Highlights: • PNIPAAm was grafted to the hydroxyl group carrying polymer beads by SI-ATRP. • Dex-g-PNIPAAm and VA-OH-g-PNIPAAm beads exhibited thermoresponsive characteristics. • They are appropriate candidates for microcarrier-facilitated cell cultures.

  17. Gradient Poly(styrene-co-polyglycidol) Grafts via Silicon Surface-Initiated AGET ATRP.

    Science.gov (United States)

    Gosecka, Monika; Pietrasik, Joanna; Decorse, Philippe; Glebocki, Bartosz; Chehimi, Mohamed M; Slomkowski, Stanislaw; Basinska, Teresa

    2015-05-01

    Gradient copolymer grafts of styrene and α-tert-butoxy-ω-vinylbenzyl-poly(glycidol ethoxyethyl ether) (PGLet), a precursor of α-tert-butoxy-ω-vinylbenzyl-polyglycidol macromonomer (PGL), were prepared on silicon wafers via a surface-initiated activator generated by electron transfer radical polymerization (AGET ATRP). Silicon plates with previously attached 2-bromoisobutyrate served as a macroinitiator for the AGET ATRP (activator generated by electron transfer) of styrene and PGLet. The copolymers' gradient P(S-co-PPGL) of composition and thickness was obtained by a simple method where the plates were slowly removed from reaction mixture using a step motor. PGLet was added continuously (dropwise) into the reactor during withdrawal of the plates from solution in order to increase the relative concentration of PGLet in polymerization mixture. A range of strategies of making grafts was tested. The plates with copolymers grafts were analyzed by various techniques, like XPS, ellipsometry, and FTIR spectroscopy. The results indicate that the AGET ATRP process is dependent on the styrene/PGLet macromonomer ratio in the polymerization mixture. Under optimal conditions, the addition of PGLet during polymerization and subsequent deprotection of hydroxyl groups of PGLet permit to obtain plates with a novel copolymer layer with composition, thickness, and wettability gradient. Plates with chemical composition of copolymer grafts gradient served as versatile supports with controlled hydrophilic/hydrophobic area and were suitable for tailored deposition of particles. PMID:25871942

  18. Nafion-Initiated ATRP of 1-Vinylimidazole for Preparation of Proton Exchange Membranes.

    Science.gov (United States)

    Feng, Kai; Liu, Lei; Tang, Beibei; Li, Nanwen; Wu, Peiyi

    2016-05-11

    Nafion is one of the most widely investigated materials applied in proton exchange membranes. Interestingly, it was found that Nafion could serve as a macroinitiator to induce atom transfer radical polymerization (ATRP) on its C-F sites. In this study, poly(1-vinylimidazole) was selectively bonded on the side chains of Nafion via the Nafion-initiated ATRP process, which was confirmed by the measurements of (1)H/(19)F nuclear magnetic resonance spectra, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, differential scanning calorimeter and matrix-assisted laser desorption ionization-time-of-flight/time-of-flight mass spectrometry. The as-prepared Nafion-co-poly(1-vinylimidazole) (Nafion-PVIm) membranes, with tunable loading amount of imidazole rings, presented greatly enhanced proton conductivity and methanol resistivity due to their well-controlled chemical structures. Especially, chemically bonding PVIm with Nafion chains endowed the Nafion-PVIm membranes with high stability in proton conductivity. For the first time, we revealed the great potentials of the Nafion-initiated ATRP process in developing high-performance proton exchange membranes. PMID:27077232

  19. Cationic quaternization of cellulose with methacryloyloxy ethyl trimethyl ammonium chloride via ATRP method

    Energy Technology Data Exchange (ETDEWEB)

    Supeno [Cenderawasih University, Jayapura, Papua, Indonesia and School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Daik, Rusli, E-mail: rusli@ukm.edu.my [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); El-Sheikh, Said M. [Nano-Structured Materials Division, Advanced Materials Department, Central Metallurgical Research and Development Institute, Cairo (Egypt)

    2014-09-03

    The synthesis of a cationic cellulose copolymer from cellulose macro-initiator (MCC-BiB) and quaternary compound monomer (METMA) via atom transfer radical polymerization (ATRP) was studied. By using dimethylformamide (DMF), the optimum condition for successful synthesis was at the mole ratio of MCC-BIB:Catalyst:METMA = 1:1:26. The highest copolymer recovery was 93.2 % for 6 h and at 40°C. The copolymer was insoluble in weak polar solvents such as THF and DMF but soluble in methanol and water. The chemistry of cellulose copolymer was confirmed by the FTIR and TGA in which the METMA monomer was used as a reference. The absence of CC bond in the CiB-g-METMA spectrum indicated that graft copolymerization occurred.

  20. Synthesis and characterization of triblock copolymer by combining enzymatic condensation polymerization and ATRP

    Institute of Scientific and Technical Information of China (English)

    LI Dongshuang; SHA Ke; LI Yapeng; WANG Shuwei; WANG Jingyuan

    2006-01-01

    The polyester poly(1,10-decanediol /1,10-sebacate) (PSD) was synthesized by means of Novozyme 435 catalyzed condensation polymerization of 1,10-decanediol and 1,10-sebacic acid. Both hydroxyl chain ends of the resulting PSD were modified by esterification with α-bromopropionyl bromide to obtain difunctional macroinitiator, which was subsequently used in the ATRP of St using CuCl/2, 2′-bipyridine (bpy) as the catalyst system to afford the triblock copolymer, polystyrene-block-poly(1,10-decanediol/1,10-sebacate)-block-polystyrene (PS t-b-PSDb-PSt). Molecular weight distribution and structure of the resulting triblock copolymer was confirmed by Waters 410 Gel permeation chromatography (GPC)and measurements of nuclear magnetic resonance (NMR) analysis.

  1. Prediction and experimental characterization of the molecular architecture of FRP and ATRP synthesized polyacrylate networks

    OpenAIRE

    Gonçalves, Miguel; Dias, Rolando; Costa, Mário Rui

    2010-01-01

    This work reports experimental and modeling studies concerning the conventional (FRP) and atom transfer radical polymerization (ATRP) of acrylate/diacrylate monomers. In the framework of a recently developed general approach, kinetic models including crosslinking reactions and branching by chain transfer to polymer are discussed for FRP and ATRP polymerization systems. Besides molecular weight distribution (MWD), fairly good predictions of the z-average radius of gyration could be obtained fo...

  2. Surface Initiated Polymerizations via e-ATRP in Pure Water

    Directory of Open Access Journals (Sweden)

    Seyed Schwan Hosseiny

    2013-10-01

    Full Text Available Here we describe the combined process of surface modification with electrochemical atom transfer radical polymerization (e-ATRP initiated from the surface of a modified gold-electrode in a pure aqueous solution without any additional supporting electrolyte. This approach allows for a very controlled growth of the polymer chains leading towards a steady increase in film thickness. Electrochemical quartz crystal microbalance displayed a highly regular increase in surface confined mass only after the addition of the pre-copper catalyst which is reduced in situ and transformed into the catalyst. Even after isolation and washing of the modified electrode surface, reinitiation was achieved with retention of the controlled electrochemical ATRP reaction. This reinitiation after isolation proves the livingness of the polymerization. This approach has interesting potential for smart thin film materials and offers also the possibility of post-modification via additional electrochemical induced reactions.

  3. Synthesis of PMMA-b-PU-b-PMMA tri-block copolymers through ARGET ATRP in the presence of air

    Directory of Open Access Journals (Sweden)

    P. Krol

    2013-03-01

    Full Text Available ARGET (activators regenerated by electron transfer ATRP (atom transfer radical polymerization has been successfully performed (in flasks fitted with rubber septa without the need for use of Schlenk line in the presence of limited amount of air and with a very small (370 ppm amount of copper catalyst together with an appropriate reducing agent Cu(0. Novelty of this work is that the poly(methyl methacrylate-block-polyurethane-block-poly(methyl methacrylate triblock copolymers were synthesized for the first time through ARGET ATRP, by using tertiary bromine-terminated polyurethane as a macroinitiator (MBP-PU-MBP, CuBr2 or CuCl2 as a catalyst and N,N,N',N",N"-pentamethyldiethylenetriamine (PMDETA or 2,2'-bipyridine (Bpy as a complexing agent. As the polymerization time increases, both the monomer conversion and ln([M]0/[M] increased and the molecular weight of copolymer increases linearly with increasing conversion. Theoretical number-average molecular weight (Mn, th of the tri-block copolymers was found to be comparable with number-average molecular weight determined by GPC analyses (Mn, GPC. These results indicate that the formation of the tri-block copolymers was through atom transfer radical polymerization mechanism. 1H and 13C NMR spectral methods were employed to confirm chemical structures of synthesized macroinitiator and tri-block copolymers. Mole percentage of PMMA in the tri-block copolymers was calculated using 1H NMR spectroscopy and was found to be comparable with the GPC results. Additionally, the studies of surface properties (confocal microscopy and SFE of tri-block copolymer coatings confirmed the presence of MMA segments.

  4. Simultaneous Photoinduced ATRP and CuAAC Reactions for the Synthesis of Block Copolymers.

    Science.gov (United States)

    Murtezi, Eljesa; Yagci, Yusuf

    2014-09-01

    Atom transfer radical polymerization (ATRP) and copper-catalyzed azide-alkyne cycloaddition (CuAAC) reactions, both utilizing copper(I) (Cu(I)) complexes, make a tremendous progress in synthetic polymer chemistry. Independently or in combination with other polymerization processes, they give access to the synthesis of polymers with well-defined structures, desired molecular architectures, and a wide variety of functionalities. Here, a novel in situ photoinduced formation of block copolymers is described by simultaneous ATRP and CuAAC processes. This approach relies on the direct reduction of initially charged copper(II) complexes to Cu(I) complexes to trigger both ATRP and CuAAC reactions coinciding under UV light at ambient temperature in one pot. Its synthetic utility is demonstrated on a model block copolymerization process by photoinduced ATRP of methyl methacrylate (MMA) using an initiator possessing acetylene functionality and concomitant click reaction between thus formed α-acetylene-poly(methyl methacrylate) (Ac-PMMA) and independently prepared azide functional polystyrene (PS-N3 ). Successful formation of PS-b-PMMA block copolymer is confirmed by FT-IR and (1) H NMR spectral analysis and gel permeation chromatography (GPC) measurements. PMID:25200624

  5. Synthesis of multi-functional nanocapsules via interfacial AGET ATRP in miniemulsion for tumor micro-environment responsive drug delivery.

    Science.gov (United States)

    Tian, Kun; Zeng, Jin; Zhao, Xubo; Liu, Lei; Jia, Xu; Liu, Peng

    2015-10-01

    Novel multi-functional polymeric hollow nanocapsules (PHN) based on the crosslinked poly(tert-butyl acrylate) (PtBA) shells were synthesized in a miniemulsion interfacial polymerization via activator generated electron transfer atom transfer radical polymerization (AGET ATRP) technique with N,N'-bis(acryloyl) cystamine (BACy) as cross-linking agent, CuBr₂ as catalyst, ascorbic acid (VC) as reducing agent and hexadecane as inert solvent. In the AGET ATRP, a folate-conjugated block copolymer, folate-poly(ethylene glycol)-b-poly(tert-butyl acrylate) (FA-PEG-tBA-Br), was used as macroinitiator/stabilizer, and the specific amphiphilic nature of the copolymer led the extending inward of polymer chains. The DLS analysis directly showed the PHN with an average diameter of 150 nm was obtained. After the PtBA shells were transformed into poly(acrylic acid) (PAA) by hydrolysis, doxorubicin (DOX), as a model drug, was loaded efficiently into the hydrolyzed polymeric hollow nanocapsules (HPHN), then the in vitro release of drug was carried out in phosphate buffer solution (PBS, pH 7.4 or 5.0, with or without DTT or GSH of different concentrations). It showed that the existence of folate group significantly improved pH stimuli-responsive and DOX-loading capacity of the polymeric nanocapsules. An acidic pH (5.0) and presence of GSH would accelerate the DOX release behavior. Thus, these multi-functional polymeric nanocapsules have excellent available properties in the field of targeted and controlled drug delivery for cancer therapy. PMID:26196091

  6. Functional lignocellulosic materials prepared by ATRP from a wood scaffold

    Science.gov (United States)

    Cabane, Etienne; Keplinger, Tobias; Künniger, Tina; Merk, Vivian; Burgert, Ingo

    2016-08-01

    Wood, a natural and abundant source of organic polymers, has been used as a scaffold to develop novel wood-polymer hybrid materials. Through a two-step surface-initiated Atom Transfer Radical Polymerization (ATRP), the porous wood structure can be effectively modified with polymer chains of various nature. In the present study, polystyrene and poly(N-isopropylacrylamide) were used. As shown with various characterization techniques including confocal Raman microscopy, FTIR, and SEM/EDX, the native wood ultrastructure and features are retained and the polymer chains can be introduced deep within the wood, i.e. inside the wood cell walls. The physical properties of the new materials have been studied, and results indicate that the insertion of polymer chains inside the wood cell wall alters the intrinsic properties of wood to yield a hybrid composite material with new functionalities. This approach to the functionalization of wood could lead to the fabrication of a new class of interesting functional materials and promote innovative utilizations of the renewable resource wood.

  7. Polymers and block copolymers of fluorostyrenes by ATRP

    DEFF Research Database (Denmark)

    Hvilsted, Søren; Borkar, Sachin; Abildgaard, Lillian; Georgieva, V.; Siesler, H.W.; Jankova, Katja Atanassova

    2002-01-01

    Fully or partly fluorinated polymers have many desirable and intriguing properties. In the framework of a larger program on design and control of new functional block copolymers we recently employed the Atom Transfer Radical Polymerization (ATRP) protocol on 2,3,4,5,6-pentafluorostyrene (FS). We...... materials based on 2,3,5,6-tetrafiuoro-4-methoxy-styrene (TFMS). TFMS homopolymers as well as diblock copolymers with FS are produced by ATRP. Both types of novel polymers were subsequently demethylated and different side chains introduced on the resulting hydroxy sites....

  8. Synthesis of cationic star polymers by simplified electrochemically mediated ATRP

    Directory of Open Access Journals (Sweden)

    P. Chmielarz

    2016-10-01

    Full Text Available Cyclodextrin-based cationic star polymers were synthesized using β-cyclodextrin (β-CD core, and 2-(dimethylamino ethyl methacrylate (DMAEMA as hydrophilic arms. Star-shaped polymers were prepared via a simplified electrochemically mediated ATRP (seATRP under potentiostatic and galvanostatic conditions. The polymerization results showed molecular weight (MW evolution close to theoretical values, and maintained narrow molecular weight distribution (MWD of obtained stars. The rate of the polymerizations was controlled by applying more positive potential values thereby suppressing star-star coupling reactions. Successful chain extension of the ω-functional arms with a hydrophobic n-butyl acrylate (BA formed star block copolymers and confirmed the living nature of the β-CD-PDMAEMA star polymers prepared by seATRP. Novelty of this work is that the β-CD-PDMAEMA-b-PBA cationic star block copolymers were synthesized for the first time via seATRP procedure, utilizing only 40 ppm of catalyst complex. The results from 1H NMR spectral studies support the formation of cationic star (copolymers.

  9. Preparation and characterization of poly(glycidyl methacrylate) grafted from magnesium hydroxide particles via SI-ATRP

    International Nuclear Information System (INIS)

    In order to improve the compatibility of magnesium hydroxide particles [Mg(OH)2] and polymer matrix, poly(glycidyl methacrylate) (PGMA) grafted from magnesium hydroxide particles were synthesized via surface-initiated atom transfer radical polymerization (SI-ATRP). In this work, two approaches for the immobilization of ATRP initiator on the magnesium hydroxide particles surface were compared and selected. The density of initiator was significantly increased by the method of introducing more hydroxyl groups via ATRP of 2-hydroxyethyl methacrylate (HEMA) on the surface. The percentage of bromine atom for the initiator-functionalized magnesium hydroxide particles [Mg(OH)2-g-PHEMA-Br] reached to 1.75%, compared to 0.48% for Mg(OH)2-Br determined by XPS analysis. The surface-initiated ATRP of glycidyl methacrylate (GMA) can be conducted in a controlled manner, as revealed by the linear kinetic plot, linear increase of number average molecular weight (Mn) with monomer conversions, and the relatively narrow molecular weight distributions (Mw/Mn ∼ 1.4) of PGMA chains. The percentage of grafting PG (%) and the thickness of the grafted polymer layer increased with the increasing of polymerization time and reached to 116.6% and 197.6 nm after 300 min respectively. As for the polymerization with different initial monomer concentration, the number average molecular weights (Mn) and weight average molecular weights (Mw) of PGMA increased with the increasing of initial monomer concentration. TGA indicated that the initial decomposition temperature of Mg(OH)2-g-PHEMA-PGMA composite particles (253 °C) was much lower than that of unmodified magnesium hydroxide particles (337 °C).

  10. Preparation and characterization of poly(glycidyl methacrylate) grafted from magnesium hydroxide particles via SI-ATRP

    Science.gov (United States)

    Liu, Jianhui; Feng, Na; Chang, Suqin; Kang, Hongliang

    2012-06-01

    In order to improve the compatibility of magnesium hydroxide particles [Mg(OH)2] and polymer matrix, poly(glycidyl methacrylate) (PGMA) grafted from magnesium hydroxide particles were synthesized via surface-initiated atom transfer radical polymerization (SI-ATRP). In this work, two approaches for the immobilization of ATRP initiator on the magnesium hydroxide particles surface were compared and selected. The density of initiator was significantly increased by the method of introducing more hydroxyl groups via ATRP of 2-hydroxyethyl methacrylate (HEMA) on the surface. The percentage of bromine atom for the initiator-functionalized magnesium hydroxide particles [Mg(OH)2-g-PHEMA-Br] reached to 1.75%, compared to 0.48% for Mg(OH)2-Br determined by XPS analysis. The surface-initiated ATRP of glycidyl methacrylate (GMA) can be conducted in a controlled manner, as revealed by the linear kinetic plot, linear increase of number average molecular weight (Mn) with monomer conversions, and the relatively narrow molecular weight distributions (Mw/Mn ˜ 1.4) of PGMA chains. The percentage of grafting PG (%) and the thickness of the grafted polymer layer increased with the increasing of polymerization time and reached to 116.6% and 197.6 nm after 300 min respectively. As for the polymerization with different initial monomer concentration, the number average molecular weights (Mn) and weight average molecular weights (Mw) of PGMA increased with the increasing of initial monomer concentration. TGA indicated that the initial decomposition temperature of Mg(OH)2-g-PHEMA-PGMA composite particles (253 °C) was much lower than that of unmodified magnesium hydroxide particles (337 °C).

  11. Preparation and characterization of poly(glycidyl methacrylate) grafted from magnesium hydroxide particles via SI-ATRP

    Energy Technology Data Exchange (ETDEWEB)

    Liu Jianhui [School of Textile and Materials Engineering, Dalian Polytechnic University, Dalian 116034 (China); Feng Na, E-mail: fengna12@163.com [School of Textile and Materials Engineering, Dalian Polytechnic University, Dalian 116034 (China); Chang Suqin [China Leather and Footwear Industry Research Institute, Beijing 100015 (China); Kang Hongliang [State Key Laboratory of Polymer Physics and Chemistry, Joint Laboratory of Polymer Science and Material, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China)

    2012-06-01

    In order to improve the compatibility of magnesium hydroxide particles [Mg(OH){sub 2}] and polymer matrix, poly(glycidyl methacrylate) (PGMA) grafted from magnesium hydroxide particles were synthesized via surface-initiated atom transfer radical polymerization (SI-ATRP). In this work, two approaches for the immobilization of ATRP initiator on the magnesium hydroxide particles surface were compared and selected. The density of initiator was significantly increased by the method of introducing more hydroxyl groups via ATRP of 2-hydroxyethyl methacrylate (HEMA) on the surface. The percentage of bromine atom for the initiator-functionalized magnesium hydroxide particles [Mg(OH){sub 2}-g-PHEMA-Br] reached to 1.75%, compared to 0.48% for Mg(OH){sub 2}-Br determined by XPS analysis. The surface-initiated ATRP of glycidyl methacrylate (GMA) can be conducted in a controlled manner, as revealed by the linear kinetic plot, linear increase of number average molecular weight (M{sub n}) with monomer conversions, and the relatively narrow molecular weight distributions (M{sub w}/M{sub n} {approx} 1.4) of PGMA chains. The percentage of grafting PG (%) and the thickness of the grafted polymer layer increased with the increasing of polymerization time and reached to 116.6% and 197.6 nm after 300 min respectively. As for the polymerization with different initial monomer concentration, the number average molecular weights (M{sub n}) and weight average molecular weights (M{sub w}) of PGMA increased with the increasing of initial monomer concentration. TGA indicated that the initial decomposition temperature of Mg(OH){sub 2}-g-PHEMA-PGMA composite particles (253 Degree-Sign C) was much lower than that of unmodified magnesium hydroxide particles (337 Degree-Sign C).

  12. Synthesis of polyacrylonitrile using AGET-ATRP in emulsion

    International Nuclear Information System (INIS)

    The technique of activators generated by electron transfer for atom transfer radical polymerization (AGET-ATRP) of acrylonitrile (AN) has been first attempted in emulsion using the procedure of “one-pot”, “two-step” with polyethylene glycol monooleyl ether (Brij 35) as surfactant, cupric chloride (CuCl2) as catalyst, hexamethylenetetramine (HMTA) as ligand, carbon tetrachloride (CCl4) as initiator and ascorbic acid (VC) as reducing agent. The polymerization proceeds in controlled/living manner as indicated by first-order kinetics of the polymerization rate with respect to the monomer concentration, linear increase of the molecular weight of polyacrylonitrile (PAN) with monomer conversion and narrow polydispersity. Monomer conversion increases initially with the increase of ligand HMTA and then decreases. The ratio of [AN1] to [AN2] at 1:3 not only gives better control on the molecular weight and the molecular weight distribution, but also provides a more rapid polymerization rate. The rate of polymerization shows a trend of increase along with CCl4 content. The apparent activation energy of the polymerization is calculated to be 46.6 kJ/mol. Chain extension of PAN with AN was also carried out and the chain extended PAN with 20520 molecular weight and 1.36 polydispersity was successfully obtained. - Graphical abstract: Kinetic plot for AGET ATRP of AN in emulsion AGET-ATRP of AN has first investigated in emulsion with HMTA as ligand, CCl4 as initiator and VC as reducing agent. The polymerizations have been successfully conducted in a controlled manner in the presence of air as evidenced by a linear first-order kinetic plot and linear increase of molecular weight with monomer conversion. Highlights: ► AGET-ATRP of AN is first investigated in emulsion. ► HMTA is used as ligand. ► Chain extension of PAN with AN verifies the living nature of the polymerization system.

  13. Hemocompatible surface of electrospun nanofibrous scaffolds by ATRP modification

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Wenjie [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Feng, Yakai, E-mail: yakaifeng@hotmail.com [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Weijin Road 92, 300072 Tianjin (China); Wang, Heyun [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832002 (China); Yang, Dazhi [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); An, Bo [Department of Orthopedics, Affiliated Hospital of Logistics University of Chinese People' s Armed Police Force, Tianjin 300162 (China); Zhang, Wencheng [Department of Physiology and Pathophysiology, Logistics University of Chinese People' s Armed Police Force, Tianjin 300162 (China); Khan, Musammir [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Guo, Jintang [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Weijin Road 92, 300072 Tianjin (China)

    2013-10-15

    The electrospun scaffolds are potential application in vascular tissue engineering since they can mimic the nano-sized dimension of natural extracellular matrix (ECM). We prepared a fibrous scaffold from polycarbonateurethane (PCU) by electrospinning technology. In order to improve the hydrophilicity and hemocompatibility of the fibrous scaffold, poly(ethylene glycol) methacrylate (PEGMA) was grafted onto the fiber surface by surface-initiated atom transfer radical polymerization (SI-ATRP) method. Although SI-ATRP has been developed and used for surface modification for many years, there are only few studies about the modification of electrospun fiber by this method. The modified fibrous scaffolds were characterized by SEM, Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS). The scaffold morphology showed no significant difference when PEGMA was grafted onto the scaffold surface. Based on the water contact angle measurement, the surface hydrophilicity of the scaffold surface was improved significantly after grafting hydrophilic PEGMA (P = 0.0012). The modified surface showed effective resistance for platelet adhesion compared with the unmodified surface. Activated partial thromboplastin time (APTT) of the PCU-g-PEGMA scaffold was much longer than that of the unmodified PCU scaffold. The cyto-compatibility of electrospun nanofibrous scaffolds was tested by human umbilical vein endothelial cells (HUVECs). The images of 7-day cultured cells on the scaffold surface were observed by SEM. The modified scaffolds showed high tendency to induce cell adhesion. Moreover, the cells reached out pseudopodia along the fibrous direction and formed a continuous monolayer. Hemolysis test showed that the grafted chains of PEGMA reduced blood coagulation. These results indicated that the modified electrospun nanofibrous scaffolds were potential application as artificial blood vessels. Highlights: • Electrospun nanofibrous scaffolds were successfully

  14. Hemocompatible surface of electrospun nanofibrous scaffolds by ATRP modification

    International Nuclear Information System (INIS)

    The electrospun scaffolds are potential application in vascular tissue engineering since they can mimic the nano-sized dimension of natural extracellular matrix (ECM). We prepared a fibrous scaffold from polycarbonateurethane (PCU) by electrospinning technology. In order to improve the hydrophilicity and hemocompatibility of the fibrous scaffold, poly(ethylene glycol) methacrylate (PEGMA) was grafted onto the fiber surface by surface-initiated atom transfer radical polymerization (SI-ATRP) method. Although SI-ATRP has been developed and used for surface modification for many years, there are only few studies about the modification of electrospun fiber by this method. The modified fibrous scaffolds were characterized by SEM, Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS). The scaffold morphology showed no significant difference when PEGMA was grafted onto the scaffold surface. Based on the water contact angle measurement, the surface hydrophilicity of the scaffold surface was improved significantly after grafting hydrophilic PEGMA (P = 0.0012). The modified surface showed effective resistance for platelet adhesion compared with the unmodified surface. Activated partial thromboplastin time (APTT) of the PCU-g-PEGMA scaffold was much longer than that of the unmodified PCU scaffold. The cyto-compatibility of electrospun nanofibrous scaffolds was tested by human umbilical vein endothelial cells (HUVECs). The images of 7-day cultured cells on the scaffold surface were observed by SEM. The modified scaffolds showed high tendency to induce cell adhesion. Moreover, the cells reached out pseudopodia along the fibrous direction and formed a continuous monolayer. Hemolysis test showed that the grafted chains of PEGMA reduced blood coagulation. These results indicated that the modified electrospun nanofibrous scaffolds were potential application as artificial blood vessels. Highlights: • Electrospun nanofibrous scaffolds were successfully

  15. Functionalization of PEDOT by Click Chemistry and ATRP

    DEFF Research Database (Denmark)

    Hoffmann, Christian; Daugaard, Anders Egede

    Poly(3,4‐ethylenedioxythiophene) (PEDOT) is a conductive polymer which has received increasing attention and many developments have been investigated. PEDOT has been applied in many different areas such as biosensors or polymer solar cells. This work presents a modification of PEDOT films through...... Click Chemistry with alkynes followed by activator regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP) to develop PEDOT films with anti‐fouling properties through application of a model system based on a crosslinked surface of polystyrene PS‐N3....

  16. Synthesis of Reactive Polymers for Acrolein Capture Using AGET ATRP.

    Science.gov (United States)

    Beringer, Laura T; Li, Shaohua; Gilmore, Gary; Lister, John; Averick, Saadyah

    2015-10-01

    Acrolein is a toxic metabolite of the anticancer agent cyclophosphamide (CP). Current strategies to mitigate acrolein toxicity are insufficient, and in this brief article, we report the synthesis of well-defined low molecular weight block copolymers using activators generated by electron transfer atom transfer radical polymerization (AGET ATRP) capable of reacting with the cytotoxic small molecule acrolein. Acrolein reactivity was introduced into the block copolymers via incorporation of either (a) aminooxy or (b) sulfhydryl groups. The cytoprotective effect of the polymers was compared to sodium 2-sulfanylethanesulfonate (mesna) the current gold standard for protection from CP urotoxicity, and we found that the polymers bearing sulfhydryl moieties demonstrated superior cytoprotective activity. PMID:26355438

  17. ATRP-derived functional polymers for electronic applications

    Science.gov (United States)

    Bucholz, Tracy; Eun Yoo, Joung; Li, Sally Peng; Loo, Yueh-Lin

    2007-03-01

    Traditionally, the controlled synthesis of functional polymers has been challenging due to the incompatibility of chemical functional groups with the propagating active centers during polymerizations. This barrier, however, has been overcome with the development of atom transfer radical polymerization (ATRP). Using this technique, in combination with ring-opening polymerization, we have successfully synthesized well-defined block copolymers containing polypentafluorostyrene (PPFS) and polylactide (PLA). Acid-catalyzed degradation of the PLA block yields PPFS films with nanoscale pores whose size and spacing are tunable through control of the diblock copolymer molecular weight and composition. The introduction of porosity to PPFS films lowers the dielectric constant, useful as isolation for interconnects. In addition, we used ATRP to synthesize well-defined homopolymers of and block copolymers containing poly(2-acrylamido-2-methyl-1-propanosulfonic acid). We used these polymers as templates for the subsequent polymerization of aniline (PANI) to create water-dispersible, directly patternable polymer conductors for thin film electronics. We can tune the conductivity of PANI through control over the molecular characteristics of the polymer acid template.

  18. Stable Poly(methacrylic acid Brush Decorated Silica Nano-Particles by ARGET ATRP for Bioconjugation

    Directory of Open Access Journals (Sweden)

    Marcello Iacono

    2015-08-01

    Full Text Available The synthesis of polymer brush decorated silica nano-particles is demonstrated by activator regeneration by electron transfer atom transfer radical polymerization (ARGET ATRP grafting of poly(tert-butyl methacrylate. ATRP initiator decorated silica nano-particles were obtained using a novel trimethylsiloxane derivatised ATRP initiator obtained by click chemistry. Comparison of de-grafted polymers with polymer obtained from a sacrificial initiator demonstrated good agreement up to 55% monomer conversion. Subsequent mild deprotection of the tert-butyl ester groups using phosphoric acid yielded highly colloidal and pH stable hydrophilic nano-particles comprising approximately 50% methacrylic acid groups. The successful bio-conjugation was achieved by immobilization of Horseradish Peroxidase to the polymer brush decorated nano-particles and the enzyme activity demonstrated in a conversion of o-phenylene diamine dihydrochloride assay.

  19. SYNTHESIS AND CHARACTERIZATION OF STRUCTURALLY WELL-DEFINED POLYMER-INORGANIC HYBRID NANOPARTICLES VIA ATRP

    Institute of Scientific and Technical Information of China (English)

    Jie Bai; Jie-bin Pang; Kun-yuan Qiu; Yen Wei

    2002-01-01

    Atom transfer radical polymerization (ATRP) using cuprous chloride/2,2'-bipyridine (bipy) was applied to graft polymerization of styrene on the surface of silica nanoparticles to synthesize polymer-inorganic hybrid nanoparticles. 2-(4-Chloromethylphenyl) ethyltriethoxysilane (CTES) was immobilized on the surface of silica nanoparticles through condensation reaction of the silanol groups on silica with triethoxysilane group of CTES. Then ATRP of St was initiated by this surface-modified silica nanoparticles bearing benzyl chloride groups, and formed PSt graft chains on the surface of silica nanoparticles. The thickness of the graft chains increased with reaction time. End group analysis confirmed the occurrence of ATRP. Thermal analysis indicated that thermal stabilization of these resulting hybrid nanoparticles also increases with polymerization conversion. The results above show that this "grafting from" reaction could be used for the preparation of polymer-inorganic hybrid nanoparticles with controlled structure of the polymer's end groups.

  20. FTIR-ATR Monitoring and SEC/RI/MALLS characterization of ATRP synthesized hyperbranched polyacrylates

    OpenAIRE

    Gonçalves, Miguel; Costa, Mário Rui; Dias, Rolando

    2009-01-01

    This work reports the synthesis at 1 L scale of hyperbranched polyacrylates based upon acrylate/diacrylate monomers such as n-butyl acrylate (nBA)/1,6-hexanediol diacrylate (HDDA) and using atom transfer radical polymerization (ATRP). A FTIR-ATR immersion probe was used to monitor the polymerization reaction. FCT

  1. New Star-Branched Poly(acrylonitrile) Architectures : ATRP Synthesis and Solution Properties

    NARCIS (Netherlands)

    Pitto, Valentina; Voit, Brigitte I.; Loontjens, Ton J.A.; Benthem, Rolf A.T.M. van

    2004-01-01

    Atom transfer radical polymerization (ATRP) has been chosen as ‘‘living’’/controlled free radical polymerization system to synthesize a number of novel poly(acrylonitrile) (PAN) architectures. The reaction conditions for the synthesis of linear samples with control over molar mass and molar mass dis

  2. Synthesis, characterization and use of ATRP bifunctional initiator with trichloromethyl end-groups

    Czech Academy of Sciences Publication Activity Database

    Toman, Luděk; Janata, Miroslav; Spěváček, Jiří; Masař, Bohumil; Vlček, Petr; Látalová, Petra

    2002-01-01

    Roč. 43, č. 2 (2002), s. 18-19. ISSN 0032-3934 R&D Projects: GA ČR GA203/01/0513 Institutional research plan: CEZ:AV0Z4050913 Keywords : bifunctional initiator * ATRP polymerization * trichloromethyl end-groups Subject RIV: CD - Macromolecular Chemistry

  3. ATRP of POSS monomers revisited: toward high-molecular weight methacrylate–POSS (co)polymers

    Czech Academy of Sciences Publication Activity Database

    Raus, Vladimír; Čadová, Eva; Starovoytova, Larisa; Janata, Miroslav

    2014-01-01

    Roč. 47, č. 21 (2014), s. 7311-7320. ISSN 0024-9297 R&D Projects: GA ČR GAP106/12/0844 Institutional support: RVO:61389013 Keywords : POSS * iBuPOSSMA * ATRP Subject RIV: CD - Macromolecular Chemistry Impact factor: 5.800, year: 2014

  4. Improved Permeate Flux of PVDF Ultrafiltration Membrane Containing PVDF-g-PHEA Synthesized via ATRP

    OpenAIRE

    Kwang-Mo Kim; Sahng Hyuck Woo; Ju Sung Lee; Hyun Sic Park; Jinwon Park; Byoung Ryul Min

    2015-01-01

    Polyvinylidene fluoride (PVDF) ultrafiltration (UF) membrane combined with polyvinylidene fluoride-graft-2-hydroxyethyl acrylate (PVDF-g-PHEA) was fabricated via non-solvent induced phase separation (NIPS). In this study, PVDF-g-PHEA was synthesized via atom transfer radical polymerization (ATRP) method, and then synthesized graft copolymer was characterized using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and thermogravimetry analysis (TGA). Moreover, PV...

  5. Controlled release of cortisone drugs from block copolymers synthetized by ATRP

    Science.gov (United States)

    Valenti, G.; La Carta, S.; Mazzotti, G.; Rapisarda, M.; Perna, S.; Di Gesù, R.; Giorgini, L.; Carbone, D.; Recca, G.; Rizzarelli, P.

    2016-05-01

    Diseases affecting posterior eye segment, like macular edema, infection and neovascularization, may cause visual impairment. Traditional treatments, such as steroidal-drugs intravitreal injections, involve chronic course of therapy usually over a period of years. Moreover, they can require frequent administrations of drug in order to have an adequately disease control. This dramatically reduce patient's compliance. Efforts have been made to develop implantable devices that offer an alternative therapeutic approach to bypass many challenges of conventional type of therapy. Implantable drug delivery systems (DDS) have been developed to optimize therapeutic properties of drugs and ensure their slow release in the specific site. Polymeric materials can play an essential role in modulating drug delivery and their use in such field has become indispensable. During last decades, acrylic polymers have obtained growing interest. Biocompatibility and chemical properties make them extremely versatile, allowing their use in many field such as biomedical. In particular, block methacrylate copolymer with a balance of hydrophilic and hydrophobic properties can be suitable for prolonged DDS in biomedical devices. In this work, we focused on the realization of a system for controlled and long term release of betamethasone 17,21-dipropionate (BDP), a cortisone drug, from methacrylic block copolymers, to be tested in the treatment of the posterior eye's diseases. Different series of methyl methacrylate/hydroxyethyl methacrylate (MMA/HEMA) block and random copolymers, with different monomer compositions (10-60% HEMA), were synthetized by Atom Transfer Radical Polymerization (ATRP) to find the best hydrophilic/hydrophobic ratio, able to ensure optimal kinetic release. Copolymer samples were characterized by NMR spectroscopy (1H-NMR, 13C-NMR, CosY), SEC, TGA and DSC. Monitoring of drug release from films loaded with BDP was carried out by HPLC analysis. Evaluation of different kinetic

  6. Use of Yb-based catalyst for AGET ATRP of acrylonitrile to simultaneously control molecular mass distribution and tacticity

    International Nuclear Information System (INIS)

    Yb-based catalyst was used for the first time for atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) with 2-bromopropionitrile (BPN) as initiator, 2, 2′-bipyridine (bipy) as ligand, and tisn(II) bis(2-ethylhexanoate) (Sn(EH)2) as reducing agent in the presence of air. With respect to AGET ATRP of AN catalyzed by CuBr2, an evident increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr3 content. The block copolymer PAN-b-PMMA with molecular weight at 60,000 and polydispersity at 1.36 was successfully prepared. - Graphical abstract: Yb-based catalyst was used for the first time for AGET ATRP of AN with BPN as the initiator, bipy as the ligand, and Sn(EH)2 as the reducing agent in the presence of air. With respect to AGET ATRP with CuBr2 as catalyst, an obvious increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr3 content. The block copolymer PAN-b-PMMA with molecular weight at 60000 and polydispersity at 1.36 was successfully prepared. Highlights: ► Yb-based catalyst was used for the first time for AGET ATRP of AN. ► The reaction simultaneously controls polydispersity and tacticity of PAN. ► Well-defined block copolymer PAN-b-PMMA was successfully prepared.

  7. Use of Yb-based catalyst for AGET ATRP of acrylonitrile to simultaneously control molecular mass distribution and tacticity

    Energy Technology Data Exchange (ETDEWEB)

    Ma Jing; Chen Hou, E-mail: lduchenhou@hotmail.com; Zhang Min; Wang Chunhua; Zhang Ying; Qu Rongjun

    2012-08-01

    Yb-based catalyst was used for the first time for atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) with 2-bromopropionitrile (BPN) as initiator, 2, 2 Prime -bipyridine (bipy) as ligand, and tisn(II) bis(2-ethylhexanoate) (Sn(EH){sub 2}) as reducing agent in the presence of air. With respect to AGET ATRP of AN catalyzed by CuBr{sub 2}, an evident increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr{sub 3} content. The block copolymer PAN-b-PMMA with molecular weight at 60,000 and polydispersity at 1.36 was successfully prepared. - Graphical abstract: Yb-based catalyst was used for the first time for AGET ATRP of AN with BPN as the initiator, bipy as the ligand, and Sn(EH){sub 2} as the reducing agent in the presence of air. With respect to AGET ATRP with CuBr{sub 2} as catalyst, an obvious increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr{sub 3} content. The block copolymer PAN-b-PMMA with molecular weight at 60000 and polydispersity at 1.36 was successfully prepared. Highlights: Black-Right-Pointing-Pointer Yb-based catalyst was used for the first time for AGET ATRP of AN. Black-Right-Pointing-Pointer The reaction simultaneously controls polydispersity and tacticity of PAN. Black-Right-Pointing-Pointer Well-defined block copolymer PAN-b-PMMA was successfully prepared.

  8. Strategies towards Novel Carbon Fiber Precursors: the Research Results on the Synthesis of PAN Copolymers via AGET ATRP and on Lignin as a Precursor

    Directory of Open Access Journals (Sweden)

    Spyridon Soulis

    2015-11-01

    Full Text Available The aim of this work is the presentation of two different approximations for improving the production of carbon fibers through the introduction of alternative precursors. The first approach concerns the development of novel polyacrylonitrile block copolymers through activators’ generated by electron transfer-atom transfer radical polymerization (AGET-ATRP reaction mechanism in microemulsion; the novel polymers are envisaged to contain a structure that will be more efficiently oxidatively stabilized and/or carbonized, with the ultimate target of CFs with improved properties. The second approximation aims at the introduction of lignin as efficient CFs precursor; this approach aims at reducing the cost of the process and increasing the production yield. Pyrolysis together with oxidative stabilization of lignin were investigated, as well as the effects on structure and thermal behavior of blending with thermoplastics. Thus far, both these methodologies exhibited significant potential and will be further developed towards full scale industrial application.

  9. FTIR-ATR monitoring and SEC/RI/MALLS characterization of ATRP synthesized hyperbranched polyacrylates

    OpenAIRE

    Gonçalves, Miguel; Pinto, Virgínia; Dias, Rolando; Costa, Mário Rui

    2010-01-01

    This work reports the synthesis at 1 L scale of hyperbranched polyacrylates based upon acrylate/diacrylate monomers such as n-butyl acrylate (nBA)/1,6-hexanediol diacrylate (HDDA) and using atom transfer radical polymerization (ATRP). A FTIR-ATR immersion probe was used to monitor the polymerization reaction. The dynamics of the build-up of polymer structure was studied by off-line analysis of samples at different reaction times by size exclusion chromatography (SEC) with detection of refract...

  10. Immobilization of α-amylase onto poly(glycidyl methacrylate) grafted electrospun fibers by ATRP

    International Nuclear Information System (INIS)

    In this study, novel α-amylase immobilized poly(vinyl alcohol) (PVA) nanofibers were prepared. The PVA nanofiber surfaces were functionalized with 2-bromoisobutyryl bromide (BiBBr) and followed by surface initiated atom transfer radical polymerization (SI-ATRP) of glycidyl methacrylate (GMA). The morphology of the poly(glycidyl methacrylate) (PGMA) grafted PVA nanofibers was characterized by scanning electron microscopy (SEM). Also PGMA brushes were confirmed by X-ray photo electron microscopy (XPS). α-Amylase was immobilized in a one step process onto the PGMA grafted PVA nanofiber. The characteristic properties of the immobilized and free enzymes were examined. The thermal stability of the enzyme was improved and showed maximum activity at 37 °C by immobilization. pH values of the maximum activity of the free and immobilized enzymes were also found at 6.0 and 6.5, respectively. Free enzyme lost its activity completely within 15 days. The immobilized enzyme lost only 23.8% of its activity within 30 days. - Highlights: • Electrospun photocrosslinkable PVA nanofiber was prepared. • PGMA brushes were conducted on PVA nanofiber via SI-ATRP. • The immobilized enzyme showed maximum activity at pH 6.0 and at 37 °C. • Functionalized nanofibers may be used as promising supports for enzyme immobilization

  11. Copolyacrylates with phenylalanine and anthracene entities prepared by ATRP and microwave irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Buruiana, E.C., E-mail: emilbur@icmpp.r [Romanian Academy, Petru Poni Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley 41A, 700487 Iasi (Romania); Murariu, Mioara; Buruiana, Tinca [Romanian Academy, Petru Poni Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley 41A, 700487 Iasi (Romania)

    2010-10-15

    In this study, two amino acid copolymers containing anthracene incorporated either on the one end, poly(N-acryloyl-L-phenylalanine-co-methyl methacrylate)-1 or as pendant groups, poly-(N-acryloyl-L-phenylalanine-co-methyl methacrylate)-2 were prepared directly from N-acryloyl-L-phenylalanine (APhe) and methyl methacrylate (MMA) through atom transfer radical polymerization (ATRP) and microwave-assisted synthesis. In the first case, 9-(chloromethyl)anthracene was used as an ATRP-initiator to obtain a copolymer that contains amino acid sequences and anthracene end-capped units (0.03 molar fraction). Rapid synthesis of copolymer under microwave irradiation (250 W) in the presence of 1,1'-azobis(cyclohexanecarbonitrile) used as an initiator was followed of a functionalization of the formed copolymer with an anthracene derivative yielding copolyacrylate with pendant anthracene (0.02 molar fraction). The structure of the copolymers was verified by {sup 1}H NMR, UV-Vis and FTIR spectroscopy, gel permeation chromatography (GPC), and fluorescence spectroscopy. The fluorescence quenching process of anthracene which exists in copolymers by FeCl{sub 3}, cobalt acetate, nitrobenzene, maleic anhydride, diethylaniline and nitromethane in DMF solutions shows that this involves an electron transfer between the excited state anthracene and the present transitional metal cations, more efficiently being FeCl{sub 3} for poly-(APhe-co-MMA)-1 and cobalt acetate for the latter copolymer.

  12. Immobilization of α-amylase onto poly(glycidyl methacrylate) grafted electrospun fibers by ATRP

    Energy Technology Data Exchange (ETDEWEB)

    Oktay, Burcu; Demir, Serap; Kayaman-Apohan, Nilhan, E-mail: napohan@marmara.edu.tr

    2015-05-01

    In this study, novel α-amylase immobilized poly(vinyl alcohol) (PVA) nanofibers were prepared. The PVA nanofiber surfaces were functionalized with 2-bromoisobutyryl bromide (BiBBr) and followed by surface initiated atom transfer radical polymerization (SI-ATRP) of glycidyl methacrylate (GMA). The morphology of the poly(glycidyl methacrylate) (PGMA) grafted PVA nanofibers was characterized by scanning electron microscopy (SEM). Also PGMA brushes were confirmed by X-ray photo electron microscopy (XPS). α-Amylase was immobilized in a one step process onto the PGMA grafted PVA nanofiber. The characteristic properties of the immobilized and free enzymes were examined. The thermal stability of the enzyme was improved and showed maximum activity at 37 °C by immobilization. pH values of the maximum activity of the free and immobilized enzymes were also found at 6.0 and 6.5, respectively. Free enzyme lost its activity completely within 15 days. The immobilized enzyme lost only 23.8% of its activity within 30 days. - Highlights: • Electrospun photocrosslinkable PVA nanofiber was prepared. • PGMA brushes were conducted on PVA nanofiber via SI-ATRP. • The immobilized enzyme showed maximum activity at pH 6.0 and at 37 °C. • Functionalized nanofibers may be used as promising supports for enzyme immobilization.

  13. Bottlebrush-shaped copolymers with cellulose diacetate backbone by a combination of ring opening polymerization and ATRP

    Czech Academy of Sciences Publication Activity Database

    Vlček, Petr; Janata, Miroslav; Látalová, Petra; Dybal, Jiří; Špírková, Milena; Toman, Luděk

    2008-01-01

    Roč. 46, č. 2 (2008), s. 564-573. ISSN 0887-624X R&D Projects: GA AV ČR IAA410820601 Institutional research plan: CEZ:AV0Z40500505 Keywords : ATRP * bottlebrush copolymers * butyl acrylate Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.821, year: 2008

  14. A Facile Strategy for Catalyst Separation and Recycling Suitable for ATRP of Hydrophilic Monomers Using a Macroligand.

    Science.gov (United States)

    Jiang, Xiaowu; Wu, Jian; Zhang, Lifen; Cheng, Zhenping; Zhu, Xiulin

    2016-01-01

    How to simply and efficiently separate and recycle catalyst has still been a constraint for the wide application of atom transfer radical polymerization (ATRP), especially for the polymerization systems with hydrophilic monomers because the polar functional groups may coordinate with transition metal salts, resulting in abundant catalyst residual in the resultant water-soluble polymers. In order to overcome this problem, a latent-biphasic system is developed, which can be successfully used for ATRP catalyst separation and recycling in situ for various kinds of hydrophilic monomers for the first time, such as poly(ethylene glycol) monomethyl ether methacrylate (PEGMA), 2-hydroxyethyl methacrylate (HEMA), 2-(dimethylamino)ethyl methacrylate (DMAEMA), N,N-dimethyl acrylamide (DMA), and N-isopropylacrylamide (NIPAM). Herein, random copolymer of octadecyl acrylate (OA), MA-Ln (2-(bis(pyridin-2-ylmethyl)amino)ethyl acrylate), and POA-ran-P(MA-Ln) is designed as the macroligand, and heptane/ethanol is selected as the biphasic solvent. Copper(II) bromide (CuBr2 ) is employed as the catalyst, PEG-bound 2-bromo-2-methylpropanoate (PEG350 -Br) as the water-soluble ATRP initiator and 2,2'-azobis(isobutyronitrile) (AIBN) as the azo-initiator to establish an ICAR (initiators for continuous activator regeneration) ATRP system. Importantly, well-defined water-soluble polymers are obtained even though the recyclable catalyst is used for sixth times. PMID:26506506

  15. Photoresponsive Azopolyester–PMMA Block Copolymers Obtained by Combination of ATRP, Polycondensation, and “Click” Chemistry

    DEFF Research Database (Denmark)

    Berges, Cristina; Javakhishvili, Irakli; Hvilsted, Søren; Sánchez, Carlos; Alcalá, Rafael

    2012-01-01

    Novel azobenzene‐containing block copolymers (BCs) with a polyester block bearing azobenzene moieties in the side chain and a poly (methyl methacrylate) (PMMA) block have been synthesized by the combination of atom transfer radical polymerization (ATRP), polycondensation, and “click” chemistry. Two...

  16. Iron-Mediated Homogeneous ICAR ATRP of Methyl Methacrylate under ppm Level Organometallic Catalyst Iron(III Acetylacetonate

    Directory of Open Access Journals (Sweden)

    Jian Wu

    2016-01-01

    Full Text Available Atom Transfer Radical Polymerization (ATRP is an important polymerization process in polymer synthesis. However, a typical ATRP system has some drawbacks. For example, it needs a large amount of transition metal catalyst, and it is difficult or expensive to remove the metal catalyst residue in products. In order to reduce the amount of catalyst and considering good biocompatibility and low toxicity of the iron catalyst, in this work, we developed a homogeneous polymerization system of initiators for continuous activator regeneration ATRP (ICAR ATRP with just a ppm level of iron catalyst. Herein, we used oil-soluble iron (III acetylacetonate (Fe(acac3 as the organometallic catalyst, 1,1′-azobis (cyclohexanecarbonitrile (ACHN with longer half-life period as the thermal initiator, ethyl 2-bromophenylacetate (EBPA as the initiator, triphenylphosphine (PPh3 as the ligand, toluene as the solvent and methyl methacrylate (MMA as the model monomer. The factors related with the polymerization system, such as concentration of Fe(acac3 and ACHN and polymerization kinetics, were investigated in detail at 90 °C. It was found that a polymer with an acceptable molecular weight distribution (Mw/Mn = 1.43 at 45.9% of monomer conversion could be obtained even with 1 ppm of Fe(acac3, making it needless to remove the residual metal in the resultant polymers, which makes such an ICAR ATRP process much more industrially attractive. The “living” features of this polymerization system were further confirmed by chain-extension experiment.

  17. Pentafluorostyrene: A valuable and flexible material design tool when mastered by ATRP

    DEFF Research Database (Denmark)

    Hvilsted, Søren

    Pentafluorostyrene is an intriguing monomer and has turned out to be an indispensable tool in the architecture of various functional materials. The ATRP merits with pentafluorostyrene was revealed a decade ago and since then especially the lability of the para-fluorine of pentafluorostyrene has...... scaffold for phophonates for polymer electrolyte membranes. This design idea was executed by use of CuAAC, where clickable azides were fabricated on the PSU (7 mol%) through lithiation chemistry at low temperature introducing first chloromethyl followed by conventional conversion of chloro groups to azides...... by sodium azide treatment. After clicking the two components together the poly(pentafluorostyrene) grafts were phosphonated. Graft copolymer (PSU-g-PhPFS) membranes could be cast that showed high thermal stability and proton conductivity. Soft silicone elastomers are materials in demand for actuators...

  18. Controlled radical polymerization of an acrylamide containing L-alanine moiety via ATRP.

    Science.gov (United States)

    Rafiee, Zahra

    2016-02-01

    Homopolymerization of an optically active acrylamide having an amino acid moiety in the side chain, N-acryloyl-L-alanine (AAla) was carried out via atom transfer radical polymerization (ATRP) at room temperature using 2-hydroxyethyl-2'-methyl-2'-bromopropionate (HMB) or sodium-4-(bromomethyl)benzoate (SBB) as initiator in pure water, methanol/water mixture and pure methanol solvents. The polymerization reaction resulted in the optically active biocompatible amino acid-based homopolymer in good yield with narrow molecular weight distribution. The number average molecular weight increased with conversion and polydispersity was low. The structure and molecular weight of synthesized polymer were characterized by (1)H NMR, FT-IR spectroscopic techniques and size-exclusion chromatography. PMID:26385362

  19. Improved Permeate Flux of PVDF Ultrafiltration Membrane Containing PVDF-g-PHEA Synthesized via ATRP

    Directory of Open Access Journals (Sweden)

    Kwang-Mo Kim

    2015-12-01

    Full Text Available Polyvinylidene fluoride (PVDF ultrafiltration (UF membrane combined with polyvinylidene fluoride-graft-2-hydroxyethyl acrylate (PVDF-g-PHEA was fabricated via non-solvent induced phase separation (NIPS. In this study, PVDF-g-PHEA was synthesized via atom transfer radical polymerization (ATRP method, and then synthesized graft copolymer was characterized using Fourier transform infrared spectroscopy (FTIR, nuclear magnetic resonance (NMR and thermogravimetry analysis (TGA. Moreover, PVDF membranes containing graft copolymer (PVDF-g-PHEA showed lower water contact angle value than pristine PVDF membranes. Macrovoid holes were also observed in cross sectional scanning electron microscope (SEM image of PVDF membrane containing PVDF-g-PHEA. Accordingly, it was confirmed that these characteristics led PVDF membrane blended with graft copolymer has high final permeate flux and normalized flux compared to pristine PVDF membrane.

  20. Optimizing conditions of preparation of thermoresponsive SiO{sub 2}-POEGMA particles via AGET-ATRP

    Energy Technology Data Exchange (ETDEWEB)

    Du, Zhiping, E-mail: duzhiping@sxu.edu.cn [Institute of Resources and Environment Engineering, Shanxi University, No. 92 Wucheng Road, Taiyuan 030006 (China); China Research Institute of Daily Chemical Industry, No.34 Wenyuan Road, Taiyuan 030001 (China); Sun, Xiaofeng; Tai, Xiumei; Wang, Guoyong; Liu, Xiaoying [China Research Institute of Daily Chemical Industry, No.34 Wenyuan Road, Taiyuan 030001 (China)

    2015-02-28

    Graphical abstract: - Highlights: • Thermosensitive SiO{sub 2} nanoparticles were prepared with POEGMA via AGET-ATRP. • Reaction conditions were optimized. • Thermosensitive properties of SiO{sub 2}-POEGMA particles were pronounced. - Abstract: Thermosensitive poly(ethylene glycol) methyl ether methacrylate (POEGMA) was grafted on SiO{sub 2} nanoparticles using activators generated by electron transfer atom transfer radical polymerization (AGET-ATRP) technique. The effects of the amount of ligand, catalyst, ascorbic acid and monomer, as well as the reaction temperature and time were systematically investigated and optimized to get a high grafting density. The structure of the hybrid materials was characterized by Fourier transform infrared (FTIR) spectroscopy, and the morphology was characterized by transmission electron microscopy (TEM) observations. Thermosensitive properties of SiO{sub 2}-POEGMA particles were investigated at different grafting densities by turbidity measurements.

  1. Controlled in situ formation of polyacrylamide hydrogel on PET surface via SI-ARGET-ATRP for wound dressings

    Energy Technology Data Exchange (ETDEWEB)

    Nazari Pour, Sedigheh [Department of Chemistry, Faculty of Science, University of Manitoba, Winnipeg, Canada R3T 2N2 (Canada); Ghugare, Shivkumar V. [Department of Textile Science, Faculty of Human Ecology, University of Manitoba, Winnipeg, Canada R3T 2N2 (Canada); Wiens, Richard; Gough, Kathleen [Department of Chemistry, Faculty of Science, University of Manitoba, Winnipeg, Canada R3T 2N2 (Canada); Liu, Song, E-mail: Song.Liu@umanitoba.ca [Department of Chemistry, Faculty of Science, University of Manitoba, Winnipeg, Canada R3T 2N2 (Canada); Department of Textile Science, Faculty of Human Ecology, University of Manitoba, Winnipeg, Canada R3T 2N2 (Canada); Department of Biosystems Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, Canada R3T 2N2 (Canada)

    2015-09-15

    Graphical abstract: - Highlights: • We grow poly(acrylamide) (PAM) hydrgol from a polymer surface in a controlled way. • Divinyl crosslinker doesn't compromise the control chain growth feature of ARGET-ATRP. • ATR-FTIR-FPA images (spatial resolution 220 nm) reveal a uniform grafting of PAM. • PAM grafted wound dressing can be dual functional: low-adherent and antibacterial. - Abstract: Well-defined polyacrylamide (PAM) hydrogel was synthesized on the surface of poly(ethylene terephthalate) (PET) film via surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET-ATRP). Following the deposition of an ATRP initiator (2-bromoisobutyrylbromide) on PET film, PAM hydrogel was grafted from the functionalized PET surface via ARGET-ATRP. XPS and FTIR-ATR confirmed that PAM hydrogel was successfully grafted on the PET surface. Results from AFM, SEM, and FTIR-FPA microscopic investigations showed that PAM hydrogel uniformly covers the surface of PET film. The grafting yield increases linearly with increasing reaction time, indicating that the growth of PAM hydrogel on the surface of PET is well controlled. In a cell adhesion assay, PAM hydrogel grafted PET films (PAM hydrogel-g-PET) showed low adhesion to keratinocyte cells. To impart PAM hydrogel-g-PET with antibacterial function, AgNPs were self-assembled along the amide side chains of PAM hydrogel. AgNPs loaded-PAM hydrogel-g-PET shows 99% reduction in the number of multidrug-resistant Pseudomonas aeruginosa within 3 h contact.

  2. Controlled in situ formation of polyacrylamide hydrogel on PET surface via SI-ARGET-ATRP for wound dressings

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • We grow poly(acrylamide) (PAM) hydrgol from a polymer surface in a controlled way. • Divinyl crosslinker doesn't compromise the control chain growth feature of ARGET-ATRP. • ATR-FTIR-FPA images (spatial resolution 220 nm) reveal a uniform grafting of PAM. • PAM grafted wound dressing can be dual functional: low-adherent and antibacterial. - Abstract: Well-defined polyacrylamide (PAM) hydrogel was synthesized on the surface of poly(ethylene terephthalate) (PET) film via surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET-ATRP). Following the deposition of an ATRP initiator (2-bromoisobutyrylbromide) on PET film, PAM hydrogel was grafted from the functionalized PET surface via ARGET-ATRP. XPS and FTIR-ATR confirmed that PAM hydrogel was successfully grafted on the PET surface. Results from AFM, SEM, and FTIR-FPA microscopic investigations showed that PAM hydrogel uniformly covers the surface of PET film. The grafting yield increases linearly with increasing reaction time, indicating that the growth of PAM hydrogel on the surface of PET is well controlled. In a cell adhesion assay, PAM hydrogel grafted PET films (PAM hydrogel-g-PET) showed low adhesion to keratinocyte cells. To impart PAM hydrogel-g-PET with antibacterial function, AgNPs were self-assembled along the amide side chains of PAM hydrogel. AgNPs loaded-PAM hydrogel-g-PET shows 99% reduction in the number of multidrug-resistant Pseudomonas aeruginosa within 3 h contact

  3. Preparation, structure and properties of multi-functional silk via ATRP method

    International Nuclear Information System (INIS)

    In order to develop multi-functional silk materials, silk was grafted using the first flame retardant monomer, dimethyl methacryloyloxyethyl phosphate (DMMEP), and the second antibacterial monomer, dimethylaminoethyl methacrylate (DMAEMA), via atom transfer radical polymerization (ATRP) method. The result of attenuated total reflection-Fourier transformed infrared spectroscopy (ATR-FTIR) indicated that two monomers were successfully grafted onto silk surface. X-ray diffraction (XRD) curves showed that grafting mainly occurred at the amorphous region of silk fibers. Thermal gravimetric analysis (TGA) and flame retardance measurements indicated that the Silk-grafted-poly(DMMEP) (Silk-g-PDMMEP) and Silk-grafted-poly(DMMEP)-blocked-poly(DMAEMA) (Silk-g-PDMMEP-b-PDMAEMA) both had good flame retardance. The LOI value could reach 31.2% and the char length was less than 6 cm for the Silk-g-PDMMEP sample with 22.21% of grafting percentage, and the LOI value was still over 28% after 50 times of washing. And the second grafts of DMAEMA monomer had no distinct effect on the flame retardance of Silk-g-PDMMEP. The inhibition rates of quaternized grafted silk to Staphylococcus aureu and Escherichia coli were both over 88%, and had excellent washing fastness. Multi-functional silk fabric with good flame retardance and anti-bacterial property could be obtained by properly controlling the grafting percentage, which had little effect on the intrinsic properties of silk fabric.

  4. A method to modify PVDF microfiltration membrane via ATRP with low-temperature plasma pretreatment

    Science.gov (United States)

    Han, Yu; Song, Shuijun; Lu, Yin; Zhu, Dongfa

    2016-08-01

    The hydrophilic modification of a polyvinylidene fluoride (PVDF) microfiltration membrane via pretreatment with argon plasma and direct surface-initiated atom transfer radical polymerization (ATRP) was studied. Both modified and unmodified PVDF membranes were characterized by Fourier transform infrared spectroscopy (FTIR), water contact angle, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and pore size distribution measurements. FTIR and XPS spectra confirmed that sulfobetaine methacrylate (SBMA) had been grafted onto the membrane surface. The initial contact angle decreased from 87.0° to 29.8° and a water drop penetrated into the modified membrane completely in 8 s. The pore size distribution of the modified membrane exhibited a smaller mean value than that of the original membrane. The antifouling properties of the modified PVDF membrane were evaluated by a filtration test using bovine serum albumin (BSA) solution. The results showed that the initial flux of the modified membrane increased from 2140.1 L/m2 h to 2812.7 L/m2 h and the equilibrium flux of BSA solution increased from 31 L/m2 h to 53 L/m2 h.

  5. Facile surface glycosylation of PVDF microporous membrane via direct surface-initiated AGET ATRP and improvement of antifouling property and biocompatibility

    International Nuclear Information System (INIS)

    This paper describes a facile and novel approach for the surface glycosylation of poly(vinylidene difluoride) (PVDF) microporous membrane. A glycopolymer poly(D-gluconamidoethyl methacrylate) (PGAMA) was tethered onto the membrane surface via activators generated by electron transfer atom transfer radical polymerization (AGET ATRP) directly initiated from the PVDF surface. Chemical changes of membrane surface were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). It was revealed that PGAMA was successfully grafted onto the membrane surface and its grafting density can be modulated in a wide range up to 2.4 μmol/cm2. The effects of glycosylation on membrane morphology, flux and surface hydrophilicity were investigated. Field emission scanning electron microscopy (FESEM) results indicated shrinkage of the surface pore diameters and the growth of the glycopolymer layer on the membrane surface. The static water contact angle (WCA) of the membrane surface decreased from 110° to 30.4° with the increase of grafting density, indicating that the PGAMA grafts dramatically improved the surface hydrophilicity. The protein adsorption and platelets adhesion experiments indicated that the grafted PGAMA could effectively improve the membrane antifouling property and biocompatibility.

  6. A versatile method for the preparation of end-functional polymers onto SiO2 nanoparticles by a combination of surface-initiated ATRP and Huisgen [3 + 2] cycloaddition

    International Nuclear Information System (INIS)

    A versatile method was developed for the chain-end functionalization of the grafted polymer chains for surface modification of nanoparticles with functionalized groups through a combination of surface-initiated atom-transfer radical polymerization (ATRP) and Huisgen [3 + 2] cycloaddition. First, the surface of SiO2 nanoparticles was modified with poly(methyl methacrylate) (PMMA) brushes via the 'grafting from' approach. The terminal bromides of PMMA-grafted SiO2 nanoparticles were then transformed into an azide function by nucleophilic substitution. These azido-terminated PMMA brushes on the nanoparticle surface were reacted with alkyne-terminated functional end group via Huisgen [3 + 2] cycloaddition. FTIR and 1H NMR spectra indicated quantitative transformation of the chain ends of PMMA brushes onto SiO2 nanoparticles into the desired functional group. And, the dispersibility of the end-functional polymer-grafted SiO2 nanoparticles was investigated with a transmission electron microscope (TEM).

  7. The Effect of Covalently-Attached ATRP-Synthesized Polymers on Membrane Stability and Cytoprotection in Human Erythrocytes

    Science.gov (United States)

    Clafshenkel, William P.; Murata, Hironobu; Andersen, Jill; Creeger, Yehuda; Russell, Alan J.

    2016-01-01

    Erythrocytes have been described as advantageous drug delivery vehicles. In order to ensure an adequate circulation half-life, erythrocytes may benefit from protective enhancements that maintain membrane integrity and neutralize oxidative damage of membrane proteins that otherwise facilitate their premature clearance from circulation. Surface modification of erythrocytes using rationally designed polymers, synthesized via atom-transfer radical polymerization (ATRP), may further expand the field of membrane-engineered red blood cells. This study describes the fate of ATRP-synthesized polymers that were covalently attached to human erythrocytes as well as the effect of membrane engineering on cell stability under physiological and oxidative conditions in vitro. The biocompatible, membrane-reactive polymers were homogenously retained on the periphery of modified erythrocytes for at least 24 hours. Membrane engineering stabilized the erythrocyte membrane and effectively neutralized oxidative species, even in the absence of free-radical scavenger-containing polymers. The targeted functionalization of Band 3 protein by NHS-pDMAA-Cy3 polymers stabilized its monomeric form preventing aggregation in the presence of the crosslinking reagent, bis(sulfosuccinimidyl)suberate (BS3). A free radical scavenging polymer, NHS-pDMAA-TEMPO˙, provided additional protection of surface modified erythrocytes in an in vitro model of oxidative stress. Preserving or augmenting cytoprotective mechanisms that extend circulation half-life is an important consideration for the use of red blood cells for drug delivery in various pathologies, as they are likely to encounter areas of imbalanced oxidative stress as they circuit the vascular system. PMID:27331401

  8. Synthesis by self-condensing AGET ATRP and solution properties of arborescent poly(sodium 2-acrylamido-2-methyl-N-propane sulfonate)

    Czech Academy of Sciences Publication Activity Database

    Gromadzki, Daniel; Tereshchenko, A.; Makuška, R.

    2010-01-01

    Roč. 51, č. 24 (2010), s. 5680-5687. ISSN 0032-3861 Grant ostatní: Europan Commission - Marie Curie Research Training Network SOCON(XE) MRTN-CT-2004-512331 Source of funding: R - rámcový projekt EK Keywords : arborescent polyelectrolytes * self condensing AGET ATRP * conformation Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.829, year: 2010

  9. Fabrication and evaluation of temperature responsive molecularly imprinted sorbents based on surface of yeast via surface-initiated AGET ATRP

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Jianming, E-mail: pjm@ujs.edu.cn; Hang, Hui; Li, Xiuxiu; Zhu, Wenjing; Meng, Minjia; Dai, Xiaohui; Dai, Jiangdong; Yan, Yongsheng

    2013-12-15

    Temperature responsive molecularly imprinted polymers (T-MIPs) were prepared based on the surface of yeast by electron transfer atom transfer radical polymerization (AGET ATRP). The as-prepared T-MIPs were charcterized by FT-IR, SEM, TGA and elemental analysis, which indicated that T-MIPs exhibited thermal stability and composed of temperature responsive imprinted layer. Then T-MIPs were evaluated as sorbents to selectively recognise and release cefalexin (CFX) molecules. The results suggested binding properties of T-MIPs were related to the testing temperature. The maximum adsorption capacity of T-MIPs at 303 K was 59.4 mg g{sup −1}, and the maximum release proportion for T-MIPs at 293 K in water for 24 h was 71.08%. The selective recognition experiments demonstrated high affinity and selectivity of T-MIPs towards CFX over competitive compounds, and the specific recognition of binding sites may be based on the distinct size, structure and functional group to the template molecules.

  10. Fabrication and evaluation of temperature responsive molecularly imprinted sorbents based on surface of yeast via surface-initiated AGET ATRP

    Science.gov (United States)

    Pan, Jianming; Hang, Hui; Li, Xiuxiu; Zhu, Wenjing; Meng, Minjia; Dai, Xiaohui; Dai, Jiangdong; Yan, Yongsheng

    2013-12-01

    Temperature responsive molecularly imprinted polymers (T-MIPs) were prepared based on the surface of yeast by electron transfer atom transfer radical polymerization (AGET ATRP). The as-prepared T-MIPs were charcterized by FT-IR, SEM, TGA and elemental analysis, which indicated that T-MIPs exhibited thermal stability and composed of temperature responsive imprinted layer. Then T-MIPs were evaluated as sorbents to selectively recognise and release cefalexin (CFX) molecules. The results suggested binding properties of T-MIPs were related to the testing temperature. The maximum adsorption capacity of T-MIPs at 303 K was 59.4 mg g-1, and the maximum release proportion for T-MIPs at 293 K in water for 24 h was 71.08%. The selective recognition experiments demonstrated high affinity and selectivity of T-MIPs towards CFX over competitive compounds, and the specific recognition of binding sites may be based on the distinct size, structure and functional group to the template molecules.

  11. Synthesis of well-defined functional PE graft copolymers via ATRP process

    Institute of Scientific and Technical Information of China (English)

    CAO Chengang; DONG Jinyong; HU Youliang

    2005-01-01

    @@ Polyethylene (PE) is one of the most important polymeric materials. It has excellent physical mechanical properties and thus a widespread range of applications. However, due to the lack of polar functional groups on its polymer chain, PE usually suffers from poor adhesion to and incompatibility with other polymers or materials, which has significantly limited many of its end uses. To resolve this problem, one of the established approaches is to introduce a second functional polymeric component as side chains to synthesize PE graft copolymers that not only provide a large quantity of functional groups to impart polarity to PE but also preserve the original desired PE properties, such as crystallinity, melting point, and hydrophobicity[1].

  12. Amphiphilic star block copolymers as gene carrier Part I: Synthesis via ATRP using calix[4]resorcinarene-based initiators and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Anna; Xue, Yan; Wei, Dafu [Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Guan, Yong, E-mail: yguan@ecust.edu.cn [Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Xiao, Huining [Department of Chemical Engineering, University of New Brunswick, Fredericton, New Brunswick, Canada E3B 5A3 (Canada)

    2013-01-01

    In this work, a cationic star polymer [poly(2-dimethylamino)ethyl methacrylate (PDMAEMA)] was prepared via atom transfer radical polymerization (ATRP), using brominated calix[4]resorcinarene as an initiator. Hydrophobic moieties, methyl methacrylate (MMA) and butyl acrylate (BA), were further incorporated via 'one-pot' method. Well-defined eight-armed star block copolymers bearing hydrophilic blocks inside and hydrophobic blocks outside were synthesized. The molecular weight, particle size, electrophoretic mobility and apparent charge density were determined by gel permeation chromatography (GPC), dynamic light scattering (DLS), phase analysis light scattering (PALS) and colloidal titration, respectively. The zeta potentials and apparent charge densities of the products exhibited the characteristics of polyelectrolyte. The incorporation of hydrophobic moieties generated electrostatic screening effect. The as-synthesized amphiphilic star copolymer is promising as a thermo-sensitive gene carrier for gene therapy. Highlights: Black-Right-Pointing-Pointer Amphiphilic cationic star block copolymers with well-controlled structures were prepared via ATRP. Black-Right-Pointing-Pointer The molecular structures and properties of the initiator and copolymers were systematically characterized. Black-Right-Pointing-Pointer The products exhibited the positive charged character, and hydrophobic moieties generated electrostatic screening effect.

  13. SYNTHESIS OF AN AMPHIPHILIC PPESK-g-P(PEGMA) GRAFT COPOLYMER VIA ATRP AND ITS USE IN BLEND MODIFICATION OF PPESK MEMBRANES

    Institute of Scientific and Technical Information of China (English)

    Han-bang Dong; You-yi Xu; Zhuan Yi

    2009-01-01

    Preparation of an amphiphilic graft copolymer having poly(phthalazinone ether sulfone ketone) (PPESK) as main chains was carried out by atom transfer radical polymerization (ATRP). The precursor, chloromethylated PPESK (CMPPESK), was prepared by using chloromethylether as chloromethylation agent. Then, poly(ethylene glycol) methyl ether methacrylate (PEGMA) was used as monomer to synthesize PPESK-g-P(PEGMA) by ATRP method under the catalysis of a cuprous chloride/2,2’-bipyridyl system. PPESK/PPESK-g-P(PEGMA) blend membranes were prepared and characterized. Chemical structures of the products were confirmed by FT-IR spectroscopy and ~1H-NMR analysis. The thermal properties of PPESK-g-P(PEGMA) were analyzed by thermal gravity analysis (TGA). XPS method was used to analyze the composition of the blend membrane. FESEM was employed to investigate the morphology of the membranes. The hydrophilicity of blend membranes was measured by water contact angle test. It turns out that the hydrophilicity and surface wettability were enhanced after modification. However, the thermal properties were negatively affected.

  14. Synthesis and characterization of brush-like multigraft copolymers PnBA-g-PMMA by a combination of emulsion AGET ATRP and emulsion polymerization.

    Science.gov (United States)

    Li, Hui; Wang, Wenwen; Li, Chunmei; Tan, Jiaojun; Yin, Dezhong; Zhang, Hepeng; Zhang, Baoliang; Yin, Changjie; Zhang, Qiuyu

    2015-09-01

    In this paper, poly(n-butyl acrylate)-g-poly(methyl methacrylate) multigraft copolymers were synthesized by macromonomer technique and miniemulsion copolymerization. The PMMA macromonomers were obtained by an activator generated by electron transfer atom transfer radical polymerization (AGET ATRP) in emulsion system and subsequent allylation. Then the copolymerization of different macromonomers with nBA was carried out in miniemulsion system, obtaining multigraft copolymers with high molecular weight. The latex particles and distribution of emulsion AGET ATRP and miniemulsion copolymerization were characterized using laser light scattering. The molecular weight and polydispersity indices of macromonomers and multigraft copolymers were analyzed by gel permeation chromatography, and the number-average molecular weight range is 187,600-554,800 g/mol for PnBA-g-PMMA copolymers. In addition, the structural characteristics of macromonomer and brush-like copolymers were determined by infrared spectra and (1)H nuclear magnetic resonance spectroscopy. The thermal performance of brush-like copolymers were characterized by differential scanning calorimetry and thermogravimetric analysis. Atomic force microscopy results showed that the degree of microphase separation was varying with increasing PMMA content in PnBA-g-PMMA. The dynamic rheometer analysis revealed that multigraft copolymer with PMMA content of 31.4% exhibited good elastomeric properties to function as a TPE. These multigraft copolymers show a promising low cost and environmental friendly thermoplastic elastomer. PMID:25988487

  15. Immobilization of poly(acrylamide) brushes onto poly(caprolactone) surface by combining ATRP and “click” chemistry: Synthesis, characterization and evaluation of protein adhesion

    International Nuclear Information System (INIS)

    Highlights: • Poly(caprolacone) (PCL) film surface was chemically modified by a novel method through combining ATRP and “click” chemistry. • Poly(acrylamide) (PAAm) of tailored chain length were synthesized and “clicked” onto PCL surface. • The modified PCL surface showed reduced BSA and Fg adsorption, and the protein resist ability in terms of chain length through its impact on grafting reaction and modified surface was investigated. - Abstract: Developments of poly(caprolactone) in blood-contacting applications are often restricted due to its intrinsic hydrophobicity. One common way to improve its hemocompatibility is to attach hydrophilic polymers. Here we developed a non-destructive method to graft hydrophilic poly(acrylamide) (PAAm) onto poly(caprolactone) (PCL) surface. In this strategy, azido-ended PCL with low molecular weights was synthesized and blended with PCL to create a surface with “clickable” property. Alkyne-ended poly(acrylamide)s with controlled chain lengths were then synthesized by atom transfer radical polymerization (ATRP), and finally were immobilized onto PCL surface by “click” reaction. The occurrence of immobilization was verified qualitatively by water contact angle measurement and quantitatively by X-ray photoelectron spectroscopy (XPS). The PAAm grafted surface exhibited fouling resistant properties, as demonstrated by reduced bovine serum albumin (BSA) and fibrinogen (Fg) adhesion

  16. Immobilization of poly(acrylamide) brushes onto poly(caprolactone) surface by combining ATRP and “click” chemistry: Synthesis, characterization and evaluation of protein adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yuhao; Bian, Xinxiu; He, Liu; Cai, Mengtan; Xie, Xiaoxiong [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China); Luo, Xianglin, E-mail: luoxl@scu.edu.cn [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China); State Key Laboratory of Polymer Material and Engineering, Sichuan University, Chengdu 610065 (China)

    2015-02-28

    Highlights: • Poly(caprolacone) (PCL) film surface was chemically modified by a novel method through combining ATRP and “click” chemistry. • Poly(acrylamide) (PAAm) of tailored chain length were synthesized and “clicked” onto PCL surface. • The modified PCL surface showed reduced BSA and Fg adsorption, and the protein resist ability in terms of chain length through its impact on grafting reaction and modified surface was investigated. - Abstract: Developments of poly(caprolactone) in blood-contacting applications are often restricted due to its intrinsic hydrophobicity. One common way to improve its hemocompatibility is to attach hydrophilic polymers. Here we developed a non-destructive method to graft hydrophilic poly(acrylamide) (PAAm) onto poly(caprolactone) (PCL) surface. In this strategy, azido-ended PCL with low molecular weights was synthesized and blended with PCL to create a surface with “clickable” property. Alkyne-ended poly(acrylamide)s with controlled chain lengths were then synthesized by atom transfer radical polymerization (ATRP), and finally were immobilized onto PCL surface by “click” reaction. The occurrence of immobilization was verified qualitatively by water contact angle measurement and quantitatively by X-ray photoelectron spectroscopy (XPS). The PAAm grafted surface exhibited fouling resistant properties, as demonstrated by reduced bovine serum albumin (BSA) and fibrinogen (Fg) adhesion.

  17. Synthetic approaches towards new polymer systems by the combination of living carbocationic and anionic polymerizations

    DEFF Research Database (Denmark)

    Feldthusen, Jesper; Ivan, Bela; Muller, Axel. H.E.; Kops, Jørgen

    1996-01-01

    Recent efforts to obtain block copolymers by combination of living carbocationic and anionic polymerizations are presented.When tolyl-ended polyisobutylene was used as macroinitiator of anionic polymerization of methacrylate derivatives mixtures of homopolymers and block copolymers were formed due...... to incomplete lithiation of this chain end.In another approach a new functionalization method was developed by end-quenching living polyisobutylene with 1,1-diphenylethylene. After transformation of the groups into 2,2-diphenylvinyl end groups and lithiation polymers were synthesized from protected...

  18. Immobilization of poly(MPC) brushes onto titanium surface by combining dopamine self-polymerization and ATRP: Preparation, characterization and evaluation of hemocompatibility in vitro

    International Nuclear Information System (INIS)

    Graphical abstract: The functional surface containing rich amino and hydroxyl groups was obtained by simple and easily dopamine self-polymerization. Poly (MPC) brushes were successfully immobilized on titanium surface by combining acylation reaction and ATRP. This chemical and biomimetic modified titanium surface effectively inhibits platelet adhesion and activation. - Highlights: • Polydopamine coating provides amino and hydroxyl groups for second reactivity. • Poly(MPC) brushes covalently immobilized on coating by surface initiated ATRP. • In vitro hemocompatibility of biomimetic modified Ti was better than unmodified. - Abstract: Poly(2-methacryloyloxyethyl phosphorylcholine(MPC)) has been studied in many biomedical fields because of good biocompatibility, such as hemocompatibility, inhibiting protein adhesion, antifouling, and so on. To achieve good hemocompatibility of titanium (Ti) surface, bio-inspired poly(MPC) brushes were grafted from Ti substrate covalently. In this work, the surface of Ti was first coated with polydopamine, and got a surface bearing −NH2 and −OH groups which could be bridged with poly(MPC) via atom transfer radical polymerization. Water contact angle decreased to 51.3° when titanium grafted with poly(MPC) brushes. The data of Infrared Spectroscopy and X-ray photoelectron spectroscopy (XPS) indicated that poly(MPC) was successfully grafted onto the surface of titanium. Platelet-rich plasma (PRP) adhesion test and lactate dehydrogenase (LDH) assay showed that the number of platelets adhered on the surface of modified-titanium was much less than that of unmodified titanium and platelets did not aggregate and distort. Thus, the simple and chemical method of immobilization of poly(MPC) brushes has potential application for improving hemocompatibility for cardiovascular stent and some other biomaterials

  19. Immobilization of poly(MPC) brushes onto titanium surface by combining dopamine self-polymerization and ATRP: Preparation, characterization and evaluation of hemocompatibility in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Wenyong; Yang, Ping; Li, Jingan; Li, Shiqi; Li, Peichuang; Zhao, Yuancong, E-mail: Zhaoyc7320@163.com; Huang, Nan

    2015-09-15

    Graphical abstract: The functional surface containing rich amino and hydroxyl groups was obtained by simple and easily dopamine self-polymerization. Poly (MPC) brushes were successfully immobilized on titanium surface by combining acylation reaction and ATRP. This chemical and biomimetic modified titanium surface effectively inhibits platelet adhesion and activation. - Highlights: • Polydopamine coating provides amino and hydroxyl groups for second reactivity. • Poly(MPC) brushes covalently immobilized on coating by surface initiated ATRP. • In vitro hemocompatibility of biomimetic modified Ti was better than unmodified. - Abstract: Poly(2-methacryloyloxyethyl phosphorylcholine(MPC)) has been studied in many biomedical fields because of good biocompatibility, such as hemocompatibility, inhibiting protein adhesion, antifouling, and so on. To achieve good hemocompatibility of titanium (Ti) surface, bio-inspired poly(MPC) brushes were grafted from Ti substrate covalently. In this work, the surface of Ti was first coated with polydopamine, and got a surface bearing −NH{sub 2} and −OH groups which could be bridged with poly(MPC) via atom transfer radical polymerization. Water contact angle decreased to 51.3° when titanium grafted with poly(MPC) brushes. The data of Infrared Spectroscopy and X-ray photoelectron spectroscopy (XPS) indicated that poly(MPC) was successfully grafted onto the surface of titanium. Platelet-rich plasma (PRP) adhesion test and lactate dehydrogenase (LDH) assay showed that the number of platelets adhered on the surface of modified-titanium was much less than that of unmodified titanium and platelets did not aggregate and distort. Thus, the simple and chemical method of immobilization of poly(MPC) brushes has potential application for improving hemocompatibility for cardiovascular stent and some other biomaterials.

  20. Controlled/living surface-initiated ATRP of antifouling polymer brushes from gold in PBS and blood sera as a model study for polymer modifications in complex biological media

    Czech Academy of Sciences Publication Activity Database

    Rodriguez-Emmenegger, Cesar; Hasan, E.; Pop-Georgievski, Ognen; Houska, Milan; Brynda, Eduard; Bologna Alles, A.

    2012-01-01

    Roč. 12, č. 4 (2012), s. 525-532. ISSN 1616-5187 R&D Projects: GA AV ČR KAN200670701; GA ČR GAP503/10/0664 Institutional research plan: CEZ:AV0Z40500505 Keywords : antifouling surfaces * atom-transfer radical polymerization (ATRP) * biocompatibility Subject RIV: EE - Microbiology, Virology Impact factor: 3.742, year: 2012

  1. AS1411 aptamer and folic acid functionalized pH-responsive ATRP fabricated pPEGMA-PCL-pPEGMA polymeric nanoparticles for targeted drug delivery in cancer therapy.

    Science.gov (United States)

    Lale, Shantanu V; R G, Aswathy; Aravind, Athulya; Kumar, D Sakthi; Koul, Veena

    2014-05-12

    Nonspecificity and cardiotoxicity are the primary limitations of current doxorubicin chemotherapy. To minimize side effects and to enhance bioavailability of doxorubicin to cancer cells, a dual-targeted pH-sensitive biocompatible polymeric nanosystem was designed and developed. An ATRP-based biodegradable triblock copolymer, poly(poly(ethylene glycol) methacrylate)-poly(caprolactone)-poly(poly(ethylene glycol) methacrylate) (pPEGMA-PCL-pPEGMA), conjugated with doxorubicin via an acid-labile hydrazone bond was synthesized and characterized. Dual targeting was achieved by attaching folic acid and the AS1411 aptamer through EDC-NHS coupling. Nanoparticles of the functionalized triblock copolymer were prepared using the nanoprecipitation method, resulting in an average particle size of ∼140 nm. The biocompatibility of the nanoparticles was evaluated using MTT cytotoxicity assays, blood compatibility studies, and protein adsorption studies. In vitro drug release studies showed a higher cumulative doxorubicin release at pH 5.0 (∼70%) compared to pH 7.4 (∼25%) owing to the presence of the acid-sensitive hydrazone linkage. Dual targeting with folate and the AS1411 aptamer increased the cancer-targeting efficiency of the nanoparticles, resulting in enhanced cellular uptake (10- and 100-fold increase in uptake compared to single-targeted NPs and non-targeted NPs, respectively) and a higher payload of doxorubicin in epithelial cancer cell lines (MCF-7 and PANC-1), with subsequent higher apoptosis, whereas a normal (noncancerous) cell line (L929) was spared from the adverse effects of doxorubicin. The results indicate that the dual-targeted pH-sensitive biocompatible polymeric nanosystem can act as a potential drug delivery vehicle against various epithelial cancers such as those of the breast, ovary, pancreas, lung, and others. PMID:24689987

  2. Synthesis and characterization of a novel acryl amide-based yttrium imprinted sorbent via the ATRP approach for the preparation of medical-grade {sup 90}Y

    Energy Technology Data Exchange (ETDEWEB)

    Abedi, Mahvash [Nuclear Schience and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of); Shahid Beheshti Univ., Tehran (Iran, Islamic Republic of). Dept. of Chemistry; Shirvani-Arani, Simindokht; Bahrami-Samani, Ali [Nuclear Schience and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of); Nabid, Mohammad Reza [Shahid Beheshti Univ., Tehran (Iran, Islamic Republic of). Dept. of Chemistry

    2016-05-01

    Because of its favorable radionuclidic properties (pure beta emitter, E{sub βmax} = 2.28 MeV, T{sub 1/2} = 64.1 h), the preparation of carrier free {sup 90}Y is of a great importance in radiopharmacy. Herein, we report the synthesis, characterization, and application of a novel yttrium sorbent prepared on the basis of the ion-imprinting concept. The ion-imprinted polymer (IIP) was prepared by atom transfer radical copolymerization of acryl amide (AAm, functional monomer) and N,N'-methylenebisacrylamide (MBAAm) crosslinking agent in the presence of a complex of yttrium ions (template ions) with a homemade chelator, i.e., 2,2-bis(2-bromo-2-methylpropanoate)propane-1,3-disuccinate (also as initiator). For elimination of yttrium ions, which act as the template, the prepared particles were treated with 50% v:v HCl: H{sub 2}O to produce yttrium-imprinted polymeric sorbent. To control the imprinting effect, corresponding non-imprinted particles (NIP) were prepared in a similar manner except that yttrium ions were not used. The synthesized chemicals for the preparation of the chelator-initiator compound and the product itself were assessed in every step using {sup 1}H-NMR analysis. NIP and YIP were subjected to X-ray diffraction (XRD), infra-red spectroscopy (IR) and BET surface area analysis for characterization studies. Sorption/desorption studies were conducted, and the effects of potentially interfering ions, such as Sr{sup 2+} (α = 119.69) and Zr{sup 4+} (α = 73.01) in presence of radio-yttrium, were investigated (particle size: 50-100 μm, resultant recovery of > 99% within 60 min and a capacity of 33.33 mg Y(III) per gram of sorbent). The results showed that amounts of radio-yttrium as low as 250 μg could be extracted effectively with high radionuclidic and radiochemical purity from macro-gram amounts of strontium.

  3. Synthesis and characterization of a novel acryl amide-based yttrium imprinted sorbent via the ATRP approach for the preparation of medical-grade 90Y

    International Nuclear Information System (INIS)

    Because of its favorable radionuclidic properties (pure beta emitter, Eβmax = 2.28 MeV, T1/2 = 64.1 h), the preparation of carrier free 90Y is of a great importance in radiopharmacy. Herein, we report the synthesis, characterization, and application of a novel yttrium sorbent prepared on the basis of the ion-imprinting concept. The ion-imprinted polymer (IIP) was prepared by atom transfer radical copolymerization of acryl amide (AAm, functional monomer) and N,N'-methylenebisacrylamide (MBAAm) crosslinking agent in the presence of a complex of yttrium ions (template ions) with a homemade chelator, i.e., 2,2-bis(2-bromo-2-methylpropanoate)propane-1,3-disuccinate (also as initiator). For elimination of yttrium ions, which act as the template, the prepared particles were treated with 50% v:v HCl: H2O to produce yttrium-imprinted polymeric sorbent. To control the imprinting effect, corresponding non-imprinted particles (NIP) were prepared in a similar manner except that yttrium ions were not used. The synthesized chemicals for the preparation of the chelator-initiator compound and the product itself were assessed in every step using 1H-NMR analysis. NIP and YIP were subjected to X-ray diffraction (XRD), infra-red spectroscopy (IR) and BET surface area analysis for characterization studies. Sorption/desorption studies were conducted, and the effects of potentially interfering ions, such as Sr2+ (α = 119.69) and Zr4+ (α = 73.01) in presence of radio-yttrium, were investigated (particle size: 50-100 μm, resultant recovery of > 99% within 60 min and a capacity of 33.33 mg Y(III) per gram of sorbent). The results showed that amounts of radio-yttrium as low as 250 μg could be extracted effectively with high radionuclidic and radiochemical purity from macro-gram amounts of strontium.

  4. “活”的α-甲基苯乙烯共聚物:聚合反应新化学和材料工程新技术%A Novel Macroinitiator Based on the Copolymer of α-Methylstyrene Synthesis and Its Application in Preparing Block and Graft Polymers

    Institute of Scientific and Technical Information of China (English)

    马育红; 张冰; 赵长稳; 刘莲英; 蒋姗; 梁淑君; 杨万泰

    2013-01-01

    Due to the steric hindrance effects in combination with stability of the tertiary benzylic a-methylstyryl radical, there is a dynamic equilibrium between the monomer a-methylstyrene (AMS) and its polymer (PAMS) when the temperature is greater than 61 ℃ (the ceiling polymerization temperature). Based on this unique feature, a novel strategy to prepare co-polymers of AMS having liable bonds as potential macromolecular free radical initiators for synthesizing block and graft copolymers has been successfully developed in our laboratory. By conventional free radical polymerization, a series of AMS copolymers, including copolymers with (meth)acrylate, acrylic acid, styrene and maleic anhydride were synthesized. Typically, with the increasing of AMS fraction in monomer feed, the rate of copolymerization was significantly retarded and the molecular weight of the copolymers was reduced. However, the copolymer yield could be as high as 90% (w) with the increased addition of initiator, up to 4% (w), and the molar fraction of AMS structural unit in AMS copolymers could be up to 25% (mol%). It has been demonstrated that the copolymers containing AMS structural units are efficient free radical initiators when the temperature is greater than 80 ℃ (much better higher than 90 ℃). These copolymers could be exploited as macroinitiator in preparing block copolymers and core-shell polymer particles by bulk, solution and emulsion polymerization processes. In addition, the experimental results demonstrated that the molecular weight of copolymer products prepared with AMS copolymers as macromolecular initiators increased steadily with the monomer conversion. Though the polymerization initiated by AMS copolymers was not a well-controlled living system yet, it showed some characteristics of living polymerization. The ESR spectrum presented direct evidence of the generation of carbon centered radicals in the products of copolymer of AMS with glycidyl methacrylate (PAG) heated with j

  5. Well-Defined Triblock Copolymer Containing Perfluoro- cyclobutyl Aryl Ether and Poly(acrylic acid) Segments

    Institute of Scientific and Technical Information of China (English)

    陆国林; 张森; 李永军; 黄晓宇

    2011-01-01

    A novel well-defined triblock copolymer containing perfluorocyclobutyl group was prepared by the combination of mechanism transformation strategy, thermal cycloaddition [2π+2π] polymerization and atom transfer radical polymerization (ATRP). Firstly, a macroinitiator with two ATRP initiating end groups was synthesized by thermal polymerization of 4,4'-bis-(trifluorovinyloxy)biphenyl (BTFVBP) and sequential end-capping with a difunctional compound containing trifluorovinyl and ATRP initiation group. Secondly, this macroinitiator initiated ATRP of t-butyl acrylate to synthesize PtBA-b-PBTFVBP-b-PtBA triblock copolymer. This copolymer was hydrolyzed to afford PAA-b-PBTFVBP-b-PAA amphiphilic triblock copolymer. This kind of fluorine-containing well-defined structure should benefit the study of self-assembly behaviors.

  6. Synthesis of densely grafted copolymers with tert-butyl methacrylate/2-(dimethylamino ethyl) methacrylate side chains as precursors for brush polyelectrolytes and polyampholytes

    Energy Technology Data Exchange (ETDEWEB)

    Gromadzki, Daniel, E-mail: d_grom@interia.pl [Department of Polymer Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania); Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague (Czech Republic); Stepanek, Petr [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague (Czech Republic); Makuska, Ricardas [Department of Polymer Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania)

    2013-01-15

    Methacrylate-based densely grafted copolymers were synthesized by atom transfer radical polymerization (ATRP) and activators generated by electron transfer for atom transfer radical polymerization (AGET ATRP) techniques. The linear poly(2-(2-bromoisobutyryloxy)ethyl methacrylate) PBIEM prepared by ATRP served as a macroinitiator backbone. The 'grafting from' strategy was used to initiate polymerization of tert-butyl methacrylate (tBuMA) from PBIEM under ATRP and/or AGET ATRP conditions yielding densely grafted copolymers PBIEM-graft-P(tBuMA). The low polydispersity indices (PDI) of the synthesized brushes evidenced by SEC analysis were consistent with a controlled/living radical polymerization (CLRP) mechanism. The chlorine-terminated PBIEM-graft-P(tBuMA)-Cl macroinitiators were subsequently employed for chain extension with 2-(dimethylamino ethyl) methacrylate (DMAEMA) yielding densely grafted copolymers with diblock copolymer side chains PBIEM-graft-P(tBuMA)-block-PDMAEMA. Further, PBIEM macroinitiator was used to initiate the copolymerization of a binary mixture of tBuMA and DMAEMA through both ATRP and AGET ATRP initiating systems, yielding densely grafted copolymers with statistical distribution of the side chains. The reactivity ratios for random graft copolymerization of tBuMA and DMAEMA from PBIEM backbone established by three different methods (Finemann-Ross, Kelen-Tuedoes and Error-in-Variable) did not substantially differ from literature values for conventional free-radical copolymerization of the same monomers. Polyampholyte brushes with PMAA-stat-PDMAEMA side chains were eventually synthesized by hydrolysis of the shielding tert-butyl groups. -- Graphical abstract: Synthesis of dense polyampholyte brushes by ATRP. A: synthesis of macroinitiator PBIEM; B: graft copolymerization of tBuMA and DMAEMA from PBIEM and hydrolysis of tBuMA units. Highlights: Black-Right-Pointing-Pointer tBuMA/DMAEMA based densely grafted brushes were prepared by ATRP

  7. Synthesis of poly(vinyl chloride)-butyl acrylate graft copolymer by ARGET ATRP method%ARGET ATRP法合成聚氯乙烯接枝丙烯酸丁酯共聚物

    Institute of Scientific and Technical Information of China (English)

    刘克勇; 包永忠

    2014-01-01

    以不稳定氯含量高的聚氯乙烯(U-PVC)和氯乙烯-溴代异丁酸烯丙酯共聚物(PVC-co-ABrMP)为大分子引发剂,使用电子转移催化再生原子转移自由基聚合(ARGET ATRP)进行丙烯酸丁酯(BA)的溶液接枝共聚。在固定CuCl2:三(2-吡啶甲基)胺:辛酸亚锡(摩尔比)时,当CuCl2用量(相对于氯乙烯链节数)小于0.1%时,BA转化率随CuCl2用量增加而明显增加;辛酸亚锡与CuCl2摩尔比大于50时,辛酸亚锡用量对聚合速率的影响较小;相同催化体系用量下,采用PVC-co-ABrMP为引发剂,可获得更高的BA转化率。通过PVC-co-ABrMP酯基水解得到PBA支链,其分子量分布指数为1.29,符合“活性”自由基聚合的特征。接枝PBA对PVC有明显的内增塑效果,PBA摩尔分数为32.75%的PVC-g-BA的玻璃化温度为8.34℃。%The grafting copolymerization of butyl acrylate (BA) onto poly(vinyl chloride) (PVC) was conducted through the method of activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP), using PVC with higher labile chlorine content (U-PVC) and vinyl chloride/allyl 2-bromo-2-methylpropionate random copolymer (PVC-co-ABrMP) as an initiator. The polymerization conversion of BA was obviously increased as CuCl2 concentration (based on number of vinyl chloride unit) increased when CuCl2 concentration was lower than 0.1%. The increase of BA polymerization rate was not obvious when Sn(EH)2/CuCl2 molar ratio exceeded 50. The greater BA polymerization rate and PBA grafting degree were achieved when PVC-co-ABrMP was used as the initiator with the same catalyst. The side PBA chains were cleaved from the ester group of PVC-co-ABrMP and the molecular weight distribution index of PBA was 1.29, verifying the “living”nature of this graft copolymerization. The grafted PBA showed good internal plasticization effect on PVC, and the glass temperature of PVC-g-BA copolymer with 32.75%(mol) PBA was reduced to 8.34℃.

  8. Controlled Synthesis of Fluorinated Copolymers with Pendant Sulfonates

    DEFF Research Database (Denmark)

    Dimitrov, Ivaylo; Jankova Atanasova, Katja; Hvilsted, Søren

    2008-01-01

    Novel fluorinated copolymers of different architectures and bearing sulfopropyl groups were synthesized by atom transfer radical polymerization (ATRP) of aromatic fluorinated monomers and two modification reactions performed on the polymer chain - demethylation followed by sulfopropylation. As a....... The second type copolymers have diblock architecture with one.of the blocks being sulfopropyl~ed. They were synthesized via ATRP of 2,3,4,5,6pentafluorostyrene (FS) initiated by PTFMS-macroinitiator followed by demethylation and sulfopropylation performed on the TFMS-block (Scheme 1). The) copolymers...

  9. Synthesis of Graft Copolymers Based on Poly(2‐Methoxyethyl Acrylate) and Investigation of the Associated Water Structure

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Tanaka, Masaru; Ogura, Keiko; Jankova Atanasova, Katja; Hvilsted, Søren

    2012-01-01

    Graft copolymers composed of poly(2‐methoxyethyl acrylate) are prepared employing controlled radical polymerization techniques. Linear backbones bearing atom transfer radical polymerization (ATRP) initiating sites are obtained by reversible addition–fragmentation chain transfer copolymerization of...... 2‐methoxyethyl acrylate (MEA) and 2‐(bromoisobutyryloxy)ethyl methacrylate (BriBuEMA) as well as 2‐hydroxyethyl methacrylate and BriBuEMA in a controlled manner . MEA is then grafted from the linear macroinitiators by Cu (I)‐mediated ATRP. Fairly high molecular weights (>120 000 Da) and low...

  10. SYNTHESIS OF POLY(METHYL METHACRYLATE)-graft-POLYSTYRENE BY ATOM TRANSFER RADICAL POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Sheng-min Gong; Qun-sheng Li; Yan Shi; Zhi-feng Fu; Shu-ke Jiao; Wan-tai Yang

    2003-01-01

    The radical copolymerization of methyl methacrylate and 2-hydroxyethyl methacrylate was carried out via atom complex. This polymerization proceeds in a living fashion with controlled molecular weight and low polydispersity. The obtained copolymer was esterified with 2-bromoisobutylryl bromide yielding a macroinitiator, poly(methyl methacrylate-co-2-hydroxyethyl methacrylate-co-2-(2-bromoisobutyryloxy)ethyl methacrylate), and its structure was characterized by 1HNMR. This macroinitiator was used for ATRP of styrene to synthesize poly(methyl methacrylate)-grafi-polystyrene. The molecular weight of graft copolymer increased with the monomer conversion, and the polydispersity remained relatively low.The individual grafted polystyrene chains were cleaved from the macroinitiator backbone by hydrolysis and the hydrolyzed product was characterized by 1H-NMR and GPC.

  11. Functional Virus-Based Polymer-Protein Nanoparticles by Atom Transfer Radical Polymerization

    OpenAIRE

    Pokorski, Jonathan K.; Breitenkamp, Kurt; Finn, M. G.

    2011-01-01

    Viruses and virus-like particles (VLPs) are useful tools in biomedical research. Their defined structural attributes make them attractive platforms for engineered interactions over large molecular surface areas. In this report, we describe the use of VLPs as multivalent macroinitiators for atom transfer radical polymerization (ATRP). The introduction of chemically reactive monomers during polymerization provides a robust platform for post-synthetic modification via the copper-catalyzed azide-...

  12. Comparative study of the catalytic activity of the complexes Cp{sup *}RuCl(PAr{sub 3}){sub 2} [Ar = -C{sub 6H}5 and 4-CF{sub 3}-C{sub 6}H{sub 4}] in the ATRP of styrene

    Energy Technology Data Exchange (ETDEWEB)

    Villa-Hernandez, Alejandro M.; Rosales-Velazquez, Claudia P.; Torres-Lubian, Jose R., E-mail: rtorres@ciqa.mx [Departamento de Sintesis de Polimeros, Centro de Investigacion en Quimica Aplicada, Coah. (Mexico); Saldivar-Guerra, Enrique [Departamento de Procesos de Polimerizacion, Centro de Investigacion en Quimica Aplicada, Coah. (Mexico)

    2011-09-15

    Styrene polymerization by ATRP was conducted independently using the complexes Cp{sup *}RuCl(PPh{sub 3}){sub 2}, and Cp{sup *}RuCl[P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}]{sub 2} as catalysts, in order to evaluate the influence of the electronic properties of the phosphine ligands on the rate and control of the polymerization. The kinetic data for polymerizations carried out with Cp{sup *}RuCl(PPh{sub 3}){sub 2}, show that molecular weights increase linearly with conversion with an average initiation efficiency of 0.77. The molecular weights obtained in the kinetic study with Cp{sup *}RuCl[P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}]{sub 2} also increase with conversion but show a marked deviation below the theoretical molecular weights. This behavior was explained by the gradual, irreversible, oxidation of catalyst Cp{sup *}RuCl[P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}]{sub 2} as confirmed by {sup 31}P-NMR spectroscopy. Catalyst Cp{sup *}RuCl(PPh{sub 3}){sub 2} promotes the polymerization with a rate of polymerization higher than that obtained using Cp{sup *}RuCl[P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}]{sub 2}; this is consistent with the better electron donating properties of PPh{sub 3} versus P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}. Preliminary studies of styrene polymerization by ATRP in supercritical CO{sub 2}, shows that only catalyst Cp{sup *}RuCl[P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}]{sub 2}, with fluorinated ligands, was active. (author)

  13. Chain extension of nitroxide-terminated polymer macroinitiators with 2-(dimethylamino)ethyl methacrylate

    Czech Academy of Sciences Publication Activity Database

    Lokaj, Jan; Poláková, Lenka; Holler, Petr; Štěpánek, Petr; Diat, O.

    Prague: Institute of Macromolecular Chemistry AS CR, 2006. s. 100. ISBN 80-85009-52-8. [Microsymposium on Structure and Dynamics of Self-organized Macromolecular Systems /45./. 09.07.2006-13.07.2006, Prague] R&D Projects: GA ČR GESON/03/E001 Institutional research plan: CEZ:AV0Z40500505 Keywords : block copolymers * 2-(dimethylamino)ethyl methacrylate Subject RIV: CD - Macromolecular Chemistry

  14. Synthesis of Several Chiral Atom Transfer Radical Polymerization Initiators and Its Helix-sense-selective Initiating Function for ATRP%几种手性原子转移自由基聚合引发剂的合成及其在螺旋选择性聚合中的应用

    Institute of Scientific and Technical Information of China (English)

    王世海; 阳年发; 杨利文; 龚行

    2012-01-01

    Five optically active alkyl bromides were synthesized and were used as chiral atom transfer radical polymeriza- tion (ATRP) initiators for the helically selective polymerization of 1-phenyldibenzosuberyl methacrylate (PDBSMA). In order to avoid the racemization of the primary free radical formed in initiating step, the optically active alkyl bromide initia- tors were designed as such a structure in which the bromine atom did not connect to the chiral center. The chiral ATRP ini- tiators tested here are (S)-2,2'-di(bromomethyl)-l,l'-binaphthyl, (S)-2-bromomethyl-2-methyl-l,l'-binaphthyl, menthyl a-bromophenylacetate, N-menthyl a-bromophenylacetamide and (3fl,5a)-cholestan-3-yl a-bromo phenylacetate. (S)-2,2'- Di(bromomethyl)-l,l'-binaphthyl, (S)-2-bromomethyl-2-methyl-l,l'-binaphthyl and menthyl a-bromophenylacetate were synthesized following the method reported by literatures. N-menthyl a-bromophenylacetamide was synthesized by adding dropwise the solution of α-bromophenylacetyl chloride in tetrahydrofuran (THF) into the mixture of menthylamine, triethyl- amine and THF with stirring at room temperature within 3 h and stirring at room temperature for another 8 h after the addi- tion. (3β,5α)-Cholestan-3-yl α-bromo phenylacetate was synthesized using the method for the synthesis of menthyl a-bromophenylacetate except using (3β,5α)-cholestanol instead of menthol. The poly-PDBSMA obtained from the ATRP initiated by the optically active alkyl bromides was fractionated into THF-soluble part and THF-insoluble part. THF-soluble part was optically active. By studying the chiroptical properties of the THF-soluble part of the poly-PDBSMA and by com- paring the optical rotation of the THF-soluble part of the poly-PDBSMA with that of the poly(methyl methacrylate) (poly-MMA) obtained under the same polymerization condition, we concluded that the ATRP initiated by the optically active alkyl bromides was

  15. Solution-Stable Colloidal Gold Nanoparticles via Surfactant-Free, Hyperbranched Polyglycerol-b-polystyrene Unimolecular Templates.

    Science.gov (United States)

    Iocozzia, James; Lin, Zhiqun

    2016-07-19

    Hyperbranched polyglycerol-block-polystyrene copolymers, denoted HPG-b-PS, are synthesized and employed as a new and effective unimolecular template for synthesizing colloidal gold (Au) nanoparticles. The coordination of noble metal precursors with polyether within the inner HPG core and subsequent in situ reduction enables the formation of well-dispersed and stable PS-capped Au nanoparticles. The inner HPG core is produced via ring opening multibranching polymerization (ROMBP) and subsequently converted into atom transfer radical polymerization (ATRP) macroinitiators for the controlled growth of polystyrene (PS) arms possessing low polydispersity (PDI numbers (98 and 117) and different PS chain lengths (i.e., molecular weight = 3500-13400 g/mol). It was found that the PS chain length and solvent conditions affect the quality of the resulting PS-capped colloidal Au nanoparticles. This work demonstrates, for the first time, a simple, lower-cost approach for templating nonpolar solvent-soluble PS-capped Au nanoparticles on the order of 10-30 nm in diameter. PMID:27357478

  16. Smart Polymeric Nanocarriers of Met-enkephalin.

    Science.gov (United States)

    Szweda, Roza; Trzebicka, Barbara; Dworak, Andrzej; Otulakowski, Lukasz; Kosowski, Dominik; Hertlein, Justyna; Haladjova, Emi; Rangelov, Stanislav; Szweda, Dawid

    2016-08-01

    This study describes a novel approach to polymeric nanocarriers of the therapeutic peptide met-enkephalin based on the aggregation of thermoresponsive polymers. Thermoresponsive bioconjugate poly((di(ethylene glycol) monomethyl ether methacrylate)-ran-(oligo(ethylene glycol) monomethyl ether methacrylate) is synthesized by AGET ATRP using modified met-enkephalin as a macroinitiator. The abrupt heating of bioconjugate water solution leads to the self-assembly of bioconjugate chains and the formation of mesoglobules of controlled sizes. Mesoglobules formed by bioconjugates are stabilized by coating with cross-linked two-layer shell via nucleated radical polymerization of N-isopropylacrylamide using a degradable cross-linker. The targeting peptide RGD, containing the fluorescence marker carboxyfluorescein, is linked to a nanocarrier during the formation of the outer shell layer. In the presence of glutathione, the whole shell is completely degradable and the met-enkephalin conjugate is released. It is anticipated that precisely engineered nanoparticles protecting their cargo will emerge as the next-generation platform for cancer therapy and many other biomedical applications. PMID:27409457

  17. Synthesis and Phase Behavior of Poly(N-isopropylacrylamide-b- Poly(L-Lysine Hydrochloride and Poly(N-Isopropylacrylamide- co-Acrylamide-b-Poly(L-Lysine Hydrochloride

    Directory of Open Access Journals (Sweden)

    Milica Spasojević

    2014-07-01

    Full Text Available The synthesis of poly(N-isopropylacrylamide-b-poly(L-lysine and poly(N- isopropylacrylamide-co-acrylamide-b-poly(L-lysine copolymers was accomplished by combining atom transfer radical polymerization (ATRP and ring opening polymerization (ROP. For this purpose, a di-functional initiator with protected amino group was successfully synthetized. The ATRP of N-isopropylacrylamide yielded narrowly dispersed polymers with consistent high yields (~80%. Lower yields (~50% were observed when narrowly dispersed random copolymers of N-isopropylacrylamide and acrylamide where synthesized. Amino-terminated poly(N-isopropylacrylamide and poly(N-isopropylacrylamide- co-acrylamide were successfully used as macroinitiators for ROP of N6-carbobenzoxy-L- lysine N-carboxyanhydride. The thermal behavior of the homopolymers and copolymers in aqueous solutions was studied by turbidimetry, dynamic light scattering (DLS and proton nuclear magnetic resonance spectroscopy (1H-NMR.

  18. Synthesis of graft copolymers based on poly(2-methoxyethyl acrylate) and investigation of the associated water structure.

    Science.gov (United States)

    Javakhishvili, Irakli; Tanaka, Masaru; Ogura, Keiko; Jankova, Katja; Hvilsted, Søren

    2012-02-27

    Graft copolymers composed of poly(2-methoxyethyl acrylate) are prepared employing controlled radical polymerization techniques. Linear backbones bearing atom transfer radical polymerization (ATRP) initiating sites are obtained by reversible addition-fragmentation chain transfer copolymerization of 2-methoxyethyl acrylate (MEA) and 2-(bromoisobutyryloxy)ethyl methacrylate (Br(i) BuEMA) as well as 2-hydroxyethyl methacrylate and Br(i) BuEMA in a controlled manner . MEA is then grafted from the linear macroinitiators by Cu (I)-mediated ATRP. Fairly high molecular weights (>120 000 Da) and low polydispersity indices (1.17-1.38) are attained. Thermal investigations of the graft copolymers indicate the presence of the freezing bound water, and imply that the materials may exhibit blood compatibility. PMID:22271568

  19. Synthesis and quaternization of nitroxide-terminated poly(4-vinylpyridine-co-acrylonitrile) macroinitiators and related diblock copolymers

    Czech Academy of Sciences Publication Activity Database

    Poláková, Lenka; Lokaj, Jan; Holler, Petr; Starovoytova, Larisa; Pekárek, Michal; Štěpánek, Petr

    -, 065 (2010), s. 1-10. ISSN 1618-7229 R&D Projects: GA ČR GESON/06/E005; GA ČR GA203/07/0659 Institutional research plan: CEZ:AV0Z40500505 Keywords : 4-vinylpyridine-acrylonitrile copolymers * block copolymers * nitroxide-mediated radical polymerization Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.574, year: 2010 http://www.e-polymers.org/journal/papers/lpolakova_240710.pdf

  20. Synthesis of 1-chloro-1-phenylethyl-telechelic polyisobutylene, a new potential macroinitiator by living cationic polymerization

    DEFF Research Database (Denmark)

    Ivan, Bela; Chen, Xianyi; Kops, Jørgen;

    1998-01-01

    1-Chloro-1-phenylethyl-telechelic polyisobutylene (PIB) was synthesized by living carbocationic polymerization (LCCP). LCCP of isobutylene was induced by a difunctional initiator in conjunction with TiCl4 as coinitiator in the presence of N,N-dimethylacetamide in CH2Cl2/hexane (40:60 v/v) solvent...

  1. Fast and Convenient Synthesis of Amine-Terminated Polylactide as a Macroinitiator for ω-Benzyloxycarbonyl-L-Lysine-N-Carboxyanhydrides

    Directory of Open Access Journals (Sweden)

    Mingjie Ju

    2011-01-01

    Full Text Available Amine-terminated poly (L-lactide (NH2-PLLA with various chain lengths were successfully synthesized by sequential tert-butyl-N-(3-hydroxypropyl carbamate initiated bulk ring-opening polymerization (ROP of L-lactide (L-LA in the presence of Stannous(II 2-ethylhexanoate (Sn(Oct2 and deprotection of the N-tert-butoxycarbonyl (Boc group at the end of the polymer chain. The polymers obtained were characterized by FT-IR, 1H NMR, and GPC method. NH2-PLLA thus prepared was used to initiate the polymerization of ω-benzyloxycarbonyl-L-lysine-N-carboxyanhydride (Lys (Z-NCA, and the result confirmed the high nucleophilicity of the terminal amine group. This method was not only suitable for the preparation of low molecular weight NH2-PLLA, but also quite efficient in the synthesis of high molecular weight samples.

  2. Synthesis of 1-chloro-1-phenylethyl-telechelic polyisobutylene, a new potential macroinitiator by living cationic polymerization

    DEFF Research Database (Denmark)

    Ivan, Bela; Chen, Xianyi; Kops, Jørgen; Batsberg, Walther

    1998-01-01

    1-Chloro-1-phenylethyl-telechelic polyisobutylene (PIB) was synthesized by living carbocationic polymerization (LCCP). LCCP of isobutylene was induced by a difunctional initiator in conjunction with TiCl4 as coinitiator in the presence of N,N-dimethylacetamide in CH2Cl2/hexane (40:60 v/v) solvent...... mixture at -78 degrees C. After complete isobutylene conversion a small amount of styrene was added leading to a rapid crossover reaction and thus to the attachment of short outer polystyrene (PSt) blocks to the PIB segment. Quenching the living polymerization of styrene yielded 1-chloro-1-phenylethyl...

  3. Magnetite nanoparticle coated with amphiphilic bilayer surfactant of polysiloxane and poly(poly(ethylene glycol) methacrylate)

    International Nuclear Information System (INIS)

    We are here reporting the surface modification of magnetite nanoparticle (MNP) with amphiphilic steric stabilizer of polydimethylsiloxane (PDMS) and poly(poly(ethylene glycol) methacrylate) (PPEGMA). The main purpose of this work is to obtain the polymeric bilayer surfactant of hydrophobic PDMS inner shell and hydrophilic PPEGMA brush corona on MNP core. Functionalized PDMS was first synthesized and then covalently grafted on the functionalized MNP surface. The PDMS-coated MNP served as a reactive macroinitiator for atom transfer radical polymerization (ATRP) of PPEGMA. Kinetics studies indicated the constant consumption of PEGMA during first 7 h of the ATRP. Transmission electron microscopy showed the average particle size of 7 nm in diameter. Fourier transform infrared spectrophotometry, thermogravimetric analysis, and vibrating sample magnetometry indicated the increase of the percentage of the copolymer in the complex when the ATRP was prolonged. The decrease in its hydrodynamic size from 446 to 162 nm when the ATRP was extended indicated the improvement in its dispersibility in water. In addition, it was found that percent entrapment efficiency and loading efficiency of indomethacin model drug in the PPEGMA-coated MNP was 62 and 27%, respectively.

  4. Comprehensive Approach

    OpenAIRE

    Vaz, Norberto

    2010-01-01

    Dada a complexidade dos conflitos e crises, muitos governos e organizações estão, actualmente, num processo de desenvolvimento de conceitos e abordagens à gestão de crises. Não há nenhuma definição comummente aceite para a Comprehensive Approach. O presente trabalho faz uma abordagem ao desenvolvimento do termo, descrevendo e analisando a adopção da Comprehensive Approach a nível multilateral. Actores multinacionais como a ONU, a OTAN e a UE estão a desenvolver novos conceitos para uma apr...

  5. Capability approach

    DEFF Research Database (Denmark)

    Jensen, Niels Rosendal; Kjeldsen, Christian Christrup

    Lærebogen er den første samlede danske præsentation af den af Amartya Sen og Martha Nussbaum udviklede Capability Approach. Bogen indeholder en præsentation og diskussion af Sen og Nussbaums teoretiske platform. I bogen indgår eksempler fra såvel uddannelse/uddannelsespolitik, pædagogik og omsorg....

  6. Narrative approaches

    DEFF Research Database (Denmark)

    Stelter, Reinhard

    -creation between coach and coachee. The conceptual framework will be tested by presenting central results of a research project. The ideas discussed in this chapter expand upon earlier concepts of the narrative approach (mainly formulated by White in 2007) by integrating ideas from phenomenology and experiential...

  7. Synthesis of thermoresponsive polystyrene-based comb-type grafted poly(N-isopropylacrylamide)

    Institute of Scientific and Technical Information of China (English)

    XU; YaXin; LI; HongTu; ZHANG; Kai; ZHANG; Bao; AI; Peng; WANG; JingYuan

    2007-01-01

    Narrowly distributed polystyrene-g-p(N-isopropylacrylamide) (PSt-g-PNIPAM) was prepared by atom transfer radical polymerization (ATRP) of N-isopropylacrylamide using the brominated polystyrene as macroinitiator and CuCl combined with hexamethyltriethylenetetramine as catalyst. Fourier transform infrared (FT-IR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy confirmed the structure of PSt-g-PNIPAM. The gel permeation chromatography (GPC) showed that the graft copolymer had a single distribution peak with molecular weight, Mn (g/mol) of 19815 g/mol (using polystyrene as the standard). Differential scanning calorimetry (DSC) revealed that due to both effects of hydrophobic isopropyl groups and hydrogen bonds in the amide group, the glass transition temperature (Tg) of PSt-g-PNIPAM enhanced 16.0℃ compared to the Tg of the polystyrene.

  8. Novel fluorescent amphiphilic block copolymers: photophysics behavior and interactions with DNA

    Directory of Open Access Journals (Sweden)

    2007-06-01

    Full Text Available In this study, novel amphiphilic fluorescent copolymers poly(N-vinylpyrrolidone-b-poly(N-methacryloyl-N'-(α-naphthylthiourea (PVP-b-PNT were synthesized via ATRP with poly(N-vinylpyrrolidone-Cl as macroinitiator and N-methacryloyl-N'-α-naphthylthiourea (NT as hydrophobic segment. PVP-b-PNT copolymers were characterized by 1H NMR, GPC-MALLS and fluorescence measurements. The aggregation behavior of PVP-b-PNT in water was investigated by transmission electron microscope (TEM and dynamic light scattering (DLS measurement. The photophysics behavior of PVP-b-PNT showed that block copolymer formed strong excimer. The interaction of DNA with the block copolymer made the excimer of block copolymer quench. The cytotoxicity result of PVP-b-PNT in cell culture in vitro indicated that this copolymer PVP-b-PNT had good biocompatibility.

  9. Pedagogical approaches

    DEFF Research Database (Denmark)

    Lund Larsen, Lea

    particular needs, which teachers must be aware of and deal with. Secondly, I propose a combination of adult learners’ characteristics with ‘teaching orientations’, as a basis for further research on teachers of adults’ professional development. Some of the competencies that teachers need can be taught in......This paper is a part of an on-going qualitative empirical research project: “Teachers of adults as learners. A study on teachers’ experiences in practice”. Data is collected at a Danish Adult Education Centre. The aim of the study is to understand teachers’ learning experiences. The research...... questions are: How (much) and what do teachers learn from experience? And how do teachers of adults develop their pedagogical approach? I examine the field of adult learners from the teachers’ perspective. Firstly, I identify some of the commonly described characteristics of adults as learners and their...

  10. POLYCHLOROALKANES AS ATRP INITIATORS. APPLICATION TO THE SYNTHESIS OF BLOCK COPOLYMERS FROM THE COMBINATION OF CONVENTIONAL RADICAL POLYMERIZATION AND ATRP. (R826735)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  11. Modification of polysulfone membranes via surface-initiated atom transfer radical polymerization

    International Nuclear Information System (INIS)

    Hydrophilic poly((poly(ethylene glycol) methyl ether methacrylate) (P(PEGMA)) and poly(glycidylmethacrylate) (PGMA) brushes were grafted from chloromethylated polysulfone (CMPSF) membrane surfaces via surface-initiated atom transfer radical polymerization (ATRP). Prior to ATRP, chloromethylation of PSF was performed beforehand and the obtained CMPSF was prepared into porous membranes by phase inversion process. It was demonstrated that the benzyl chloride groups on the CMPSF membrane surface afforded effective macroinitiators to graft the well-defined polymer brushes. 1H NMR was employed to confirm the structure of CMPSF. The grafting yield of P(PEGMA) and PGMA was determined by weight gain measurement. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed the grafting of P(PEGMA) and PGMA chains. Water contact angle measurements indicated that the introduction of P(PEGMA) and PGMA graft chains promoted remarkably the surface hydrophilicity of PSF membranes. The effects of P(PEGMA) and PGMA immobilization on membrane morphology, permeability and fouling resistance were investigated. It was found that P(PEGMA) and PGMA grafts brought higher pure water flux, improved hydrophilic surface and better anti-protein absorption ability to PSF membranes after modification. And evidently, macromonomer P(PEGMA) brought much better properties to the PSF membranes than PGMA macromonomer.

  12. PEGylated Fluorescent Nanoparticles from One-Pot Atom Transfer Radical Polymerization and “Click Chemistry”

    Directory of Open Access Journals (Sweden)

    Li Qun Xu

    2015-10-01

    Full Text Available The preparation of PEGylated fluorescent nanoparticles (NPs based on atom transfer radical polymerization (ATRP and “click chemistry” in one-pot synthesis is presented. First, poly(p-chloromethyl styrene-alt-N-propargylmaleimide (P(CMS-alt-NPM copolymer was prepared via reversible addition-fragmentation chain transfer (RAFT polymerization. Subsequently, the azido-containing fluorene-based polymer, poly[(9,9-dihexylfluorene-alt-(9,9-bis-(6-azidohexylfluorene] (PFC6N3, was synthesized via Suzuki coupling polymerization, followed by azidation. Finally, the PEGylated fluorescent NPs were prepared via simultaneous intermolecular “click” cross-linking between P(CMS-alt-NPM and PFC6N3 and the ATRP of poly(ethylene glycol methyl ether methacrylate (PEGMMA using P(CMS-alt-NPM as the macroinitiator. The low cytotoxicity of the PEGylated fluorescent NPs was revealed by incubation with KB cells, a cell line derived from carcinoma of the nasopharynx, in an in vitro experiment. The biocompatible PEGylated fluorescent NPs were further used as a labeling agent for KB cells.

  13. Superhydrophobic surfaces of electrospun block copolymer fibers with low content of fluorosilicones

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Xiaoping [Key Laboratory of Advanced Textile Materials and Manufacturing Technology, Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Engineering Research Center for Eco-Dyeing and Finishing of Textiles, Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Yi, Lingmin, E-mail: lmyi@zstu.edu.cn [Key Laboratory of Advanced Textile Materials and Manufacturing Technology, Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Engineering Research Center for Eco-Dyeing and Finishing of Textiles, Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, NJ 07030 (United States); Meng, Xiaomei; Xu, Kai [Key Laboratory of Advanced Textile Materials and Manufacturing Technology, Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Engineering Research Center for Eco-Dyeing and Finishing of Textiles, Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Jiang, Tengteng; Lai, Dongzhi [Key Laboratory of Advanced Textile Materials and Manufacturing Technology, Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018 (China)

    2014-07-01

    A series of well-defined poly[methyl(3,3,3-trifluoropropyl)siloxane]-b-poly(methyl methacrylate) (PMTFPS-b-PMMA) diblock copolymers with low content of PMTFPS were synthesized by atom transfer radical polymerization (ATRP) of MMA from PMTFPS macroinitiators (PMTFPS-Br). The polymerization result reveals that the ATRP of MMA from PMTFPS-Br is fist-order with respect to MMA under different polymerization conditions, demonstrating a typical characteristic of living polymerization. The results also show that PMTFPS-b-PMMA diblock copolymers can exhibit a total surface tension (γ{sub S}) varying from 25.28 mN/m to 21.87 mN/m with the change of PMTFPS contents from 2.6 wt% to 22.2 wt%. Moreover, the water contact angles of electrospun PMTFPS-b-PMMA surfaces could be higher than 150° with water roll-off angles less than 10°, which denotes a superhydrophobic property. However, the electronspinning conditions, especially the concentration of spinning solution, would have important effect on the surface morphology, surface composition and wetting behavior of electrospun films. It was found that bead-free fibers with uniform diameter as well as good superhydrophobic property could be prepared on condition that the polymer concentration of spinning solution was as high as 32 wt% in the mixed solvent of DMF and THF.

  14. In situ preparation and fluorescence quenching properties of polythiophene/ZnO nanocrystals hybrids through atom-transfer radical polymerization and hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Peng Xiaoming; Zhang Lin [Department of Chemistry, Nanchang University, Xuefu Road 999, Nanchang 330031 (China); Institute of Polymers/Institute for Advanced study, Nanchang University, Xuefu Road 999, Nanchang 330031 (China); Chen Yiwang, E-mail: ywchen@ncu.edu.cn [Department of Chemistry, Nanchang University, Xuefu Road 999, Nanchang 330031 (China); Institute of Polymers/Institute for Advanced study, Nanchang University, Xuefu Road 999, Nanchang 330031 (China); Li Fan, E-mail: lfan@ncu.edu.cn [Institute of Polymers/Institute for Advanced study, Nanchang University, Xuefu Road 999, Nanchang 330031 (China); Zhou Weihua [Institute of Polymers/Institute for Advanced study, Nanchang University, Xuefu Road 999, Nanchang 330031 (China)

    2010-02-15

    In this paper, a new approach for in situ preparing nanocomposites of conjugated polymers (CPs) and semiconductor nanocrystals was developed. Polythiophene grafted poly(zinc methacrylate) (PTh-g-PZMA) copolymer was synthesized by atom-transfer radical polymerization (ATRP) of zinc methacrylate (ZMA) initiated from the macroinitiator poly(2,5-(3-(bromoisopropyl-carbonyl-oxymethylene) thiophene)) (PTh-Br) with pendant initiator groups. Subsequently, the polythiophene grafted poly(methacrylate)/ZnO (PTh-g-PMA/ZnO) hybrid heterojunction nanocomposites were successfully prepared by in situ hydrolysis of PTh-g-PZMA casting films in alkaline aqueous solution. The structures of PTh-Br, PTh-g-PZMA and PTh-g-PMA/ZnO were confirmed by the proton nuclear magnetic resonance ({sup 1}H NMR) spectra, Fourier transform infrared (FTIR) spectra and X-ray photoelectron spectroscopy (XPS). The morphologies of PTh-g-PMA/ZnO films prepared for different hydrolysis time were observed in the cross-sections by scanning electron microscope (SEM). The SEM images revealed that ZnO nanocrystals were uniformly dispersed in polymers without any aggregation and the appearances of ZnO nanocrystals changed from nanoparticles to nanorods with the hydrolysis treatment time increasing. The optical properties of these nanocomposites were studied by ultraviolet-visible (UV-vis) absorption and fluorescence spectroscopy. UV-vis absorption spectroscopy showed that the adsorption band of PTh-g-PMA/ZnO hybrids was broader than that of PTh-Br, implying that the existence of ZnO nanocrystals increased the optical absorption region of hybrids. The photoluminescence (PL) spectra of the hybrids showed that fluorescence quenching occurred in PTh-g-PMA/ZnO blends and a maximum of 85% of the fluorescence intensity quenched in the PTh-g-PMA/ZnO obtained from treatment in NaOH aqueous solution for 2 h, which revealed the existence of photo-induced charge transfer between the polythiophene chains and ZnO. These results

  15. Nitroxide mediated and atom transfer radical graft polymerization of atactic polymers onto syndiotactic polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, M. [Department of Basic Science, Payame Noor University, Tehran (Iran, Islamic Republic of); Shoja, S. Esmaeily [Lab. of Materials, Faculty of Engineering, Islamic Azad University, Bonab (Iran, Islamic Republic of)

    2012-04-15

    'Living' radical graft polymerization was employed to prepare graft copolymers with nitroxide mediated arylated syndiotactic polystyrene as the backbone and polystyrene (PS), poly(p-methylstyrene) (PMS) and poly(methylmethacrylate) (PMMA) as branches. A two-stage process has been developed to synthesize the macroinitiator. First, syndiotactic polystyrene (sPS) was modified by the Friedel-Crafts reaction to introduce chlorine; second, the chlorine groups were converted to nitroxide mediated groups by coupling with 1-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO-OH). The resulting macroinitiator (sPSTEMPO) for 'living' free radical polymerization was then heated in the presence of styrene and pmethylstyrene to form graft and block copolymers. We used the obtained copolymer and N-bromosuccinimide as brominating agent to achieve polymers with bromine groups. This brominated copolymer was used as a macroinitiator for polymerizing methyl methacrylate in the presence of the CuBr/bpy catalyst system. The formation of the graft and block copolymers was confirmed by DSC, {sup 1}H NMR and FTIR spectroscopy. This approach using macroinitiators is an effective method for the preparation of new materials. (author)

  16. Modification of Jute Fibers with Polystyrene via Atom Transfer Radical Polymerization

    DEFF Research Database (Denmark)

    Plackett, David; Jankova, Katja Atanassova; Egsgaard, Helge;

    2005-01-01

    Atom transfer radical polymerization (ATRP) was investigated as a method of covalently bonding polystyrene to jute (Corchorus capsularis) and as a possible approach to fiber composites with enhanced properties. Jute fibers were modified with a brominated initiator and subsequently ATRP modified to...... attach polystyrene and then examined using SEM, DSC, TGA, FTIR, XPS, elemental analysis, and Py-GC-MS. These techniques confirmed that polystyrene had been covalently bound to the fibers and consequently ATRP-modified jute fiber mats were used to prepare hot-pressed polystyrene composites. Composite...... applications, we conclude that further optimization of the ATRP method is required, possibly targeting higher and more uniform loading of polystyrene on the fibers....

  17. APPROACHES TO SOCIAL ANXIETY

    OpenAIRE

    ÖZTÜRK, Abdülkadir

    2014-01-01

    The communication process that influences human lives is negatively affected by social anxiety. There have been many studies conducted and perspectives introduced about social anxiety. The purpose of this study is to explain social anxiety through examining approaches regarding social anxiety and investigate the sufficiency of those approaches. In this study, approaches about social anxiety are categorized in five groups. These categories are biological approach, psychological approach, cult...

  18. Grafting of graphene oxide with stimuli-responsive polymers by using ATRP for drug release

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Shenmin, E-mail: smzhu@sjtu.edu.cn; Li Jingbo; Chen Yuhang [Shanghai Jiao Tong University, State Key Laboratory of Metal Matrix Composites, School of Electronic, Information and Electrical Engineering (China); Chen Zhixin [University of Wollongong, Faculty of Engineering (Australia); Chen Chenxin; Li Yao; Cui Zhaowen; Zhang Di, E-mail: zhangdi@sjtu.edu.cn [Shanghai Jiao Tong University, State Key Laboratory of Metal Matrix Composites, School of Electronic, Information and Electrical Engineering (China)

    2012-09-15

    A thermo-responsive drug delivery system was reported based on grafting of stimuli-responsive poly(N-isopropylacrylamide) (PNIPA) on the surface of graphene oxide (GO) via atom transfer radical polymerization. The successful synthesis of PNIPA attached on GO (GO-PNIPA) was confirmed by X-ray photoelectron spectrum, X-ray diffraction, atomic force microscope, field-emission scanning electron microscopy, and transmission electron microscopy measurements. Control of drug release through the composite GO-PNIPA was performed by measuring the uptake and release of ibuprofen (IBU). It was found the delivery system demonstrated a much high IBU storage of 280 wt%, attributing to the formation of the hydrogen bonding between the polymers on the GO surface and IBU as well as the large number of internal cavities of the PNIPA chains. In vitro test of IBU release exhibited a narrow pronounced transition at around 22 Degree-Sign C, indicating an attractive thermo-sensitive release property of this delivery system. The strategy may pave the way for the use of GO in numerous applications, from drug delivery to thermally responsive micro- and nano-devices.

  19. RAFT vs. ATRP polymerization of N-(Tris(hydroxymethyl)methyl)-acrylamide for new nonfouling polymer brushes

    Czech Academy of Sciences Publication Activity Database

    Surman, František; Rodriguez-Emmenegger, Cesar; de los Santos Pereira, Andres; Šubr, Vladimír; Houska, Milan; Kaňková, Dana; Sedláková, Zdeňka

    Pisa : European Polymer Federation, 2013. O3-84. [European Polymer Congress - EPF 2013. 16.06.2013-21.06.2013, Pisa] R&D Projects: GA ČR GAP106/12/1451; GA ČR GAP205/12/1702 Institutional support: RVO:61389013 Keywords : non-fouling polymer brushe * RAFT polymerization Subject RIV: CD - Macromolecular Chemistry

  20. Synthesis of defined POSS-containing diblock and triblock methacrylate copolymers by ATRP

    Czech Academy of Sciences Publication Activity Database

    Janata, Miroslav; Raus, Vladimír; Sikora, Antonín; Čadová, Eva; Látalová, Petra

    Pisa : European Polymer Federation, 2013. P1-41. [European Polymer Congress - EPF 2013. 16.06.2013-21.06.2013, Pisa] R&D Projects: GA ČR GAP106/12/0844 Institutional support: RVO:61389013 Keywords : atom transfer radical polymerization * block copolymers * polyhedral oligosilsesquioxanes Subject RIV: CD - Macromolecular Chemistry

  1. Graphene oxide modified with PMMA via ATRP as a reinforcement filler

    OpenAIRE

    Gonçalves, Gil; Paula A. A. P. Marques; Barros-Timmons, Ana; Bdikin, Igor; Singh, Manoj K; Emami, Nazanin; Grácio, José

    2010-01-01

    Graphene is a two-dimensional new allotrope of carbon, which is stimulating great curiosity due to its superior mechanical, electrical, thermal and optical properties. Particularly attractive is the availability of bulk quantities of graphene (G) which can be easily processed by chemical exfoliation, yielding graphene oxide (GO). The resultant oxygenated graphene sheets covered with hydroxyl, epoxy and carboxyl groups offer tremendous opportunities for further functionalization opening plenty...

  2. Self-assembled Block Copolymers with Various Architectures Designed by ATRP

    DEFF Research Database (Denmark)

    Jankova Atanasova, Katja

    networks and demonstrate good Li+ complexation and conductivity. These make the materials a potential for solid electrolyte applications in Li+ ion batteries (4, 6). iii. Amphiphilic water soluble star block copolymers with a polyacrylic acid core form hydrogels at room temperature above concentration 22g...

  3. DEACTIVATION EFFICIENCY OF AND DEGREE OF CONTROL OVER POLYMERIZATION IN ATRP IN PROTIC SOLVENTS. (R829580)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  4. Grafting of graphene oxide with stimuli-responsive polymers by using ATRP for drug release

    International Nuclear Information System (INIS)

    A thermo-responsive drug delivery system was reported based on grafting of stimuli-responsive poly(N-isopropylacrylamide) (PNIPA) on the surface of graphene oxide (GO) via atom transfer radical polymerization. The successful synthesis of PNIPA attached on GO (GO–PNIPA) was confirmed by X-ray photoelectron spectrum, X-ray diffraction, atomic force microscope, field-emission scanning electron microscopy, and transmission electron microscopy measurements. Control of drug release through the composite GO–PNIPA was performed by measuring the uptake and release of ibuprofen (IBU). It was found the delivery system demonstrated a much high IBU storage of 280 wt%, attributing to the formation of the hydrogen bonding between the polymers on the GO surface and IBU as well as the large number of internal cavities of the PNIPA chains. In vitro test of IBU release exhibited a narrow pronounced transition at around 22 °C, indicating an attractive thermo-sensitive release property of this delivery system. The strategy may pave the way for the use of GO in numerous applications, from drug delivery to thermally responsive micro- and nano-devices.

  5. Synthesis and ATRP of novel fluorinated aromatic monomer with pendant sulfonate group

    DEFF Research Database (Denmark)

    Dimitrov, Ivaylo; Jankova Atanasova, Katja; Hvilsted, Søren

    2013-01-01

    Novel, fluorinated monomer with pendant sulfonate group was synthesized utilizing a two-step derivatization of 2,3,4,5,6-pentafluorostyrene (FS). The first step was a nucleophilic substitution of the fluorine atom in para position by hydroxyl group followed by sulfopropylation. The monomer was po...

  6. Life Span Developmental Approach

    OpenAIRE

    Eryılmaz, Ali

    2011-01-01

    The Life Span Developmental Approach examines development of individuals which occurs from birth to death. Life span developmental approach is a multi-disciplinary approach related with disciplines like psychology, psychiatry, sociology, anthropology and geriatrics that indicates the fact that development is not completed in adulthood, it continues during the life course. Development is a complex process that consists of dying and death. This approach carefully investigates the development of...

  7. Holistic Approaches to Health.

    Science.gov (United States)

    Dinkmeyer, Don; Dinkmeyer, Don, Jr.

    1979-01-01

    The holistic approach to health includes a spectrum of concepts that have an important influence on our health. Elementary school counselors must recognize this previously neglected need for a holistic approach. Stress, relaxation response, biofeedback, and the orthomolecular approach are discussed. (Author/BEF)

  8. Evaluating six soft approaches

    Directory of Open Access Journals (Sweden)

    Lene Sørensen

    2008-09-01

    Full Text Available The paper introduces and evaluates six soft approaches used in strategy development and planning. We take a planner’s perspective on discussing the concepts of strategy development and planning. This means that we see strategy development and planning as learning processes based on Ackoff’s interactive planning principles to be supported by soft approaches in carrying out the principles in action. These six soft approaches are suitable for supporting various steps of the strategy development and planning process. These are the SWOT analysis, the Future Workshop, the Scenario methodology, Strategic Option Development and Analysis, Strategic Choice Approach and Soft Systems Methodology. Evaluations of each methodology are carried out using a conceptual framework in which the organisation, the result, the process and the technology of the specific approach are taken into consideration. Using such a conceptual framework for evaluations of soft approaches increases the understanding of them, their transparency, and their usability in practice.

  9. RESEARCH APPROACH: AN OVERVIEW

    OpenAIRE

    Vijay Kumar Grover

    2015-01-01

    The paper attempts to explain different possible research approaches to pursue a research project. It starts with three important components of a research approach amelyphilosophical world view, research design, and research methods. Research approaches are classified on the basis of work of Guba (1990), which puts it in to the categories of post positivism, constructivism, transformative and pragmatism. Further paper explains salient features and principals of these four world views. ...

  10. The sustainable livelihoods approach

    DEFF Research Database (Denmark)

    Oelofse, Myles; Jensen, Henning Høgh

    2008-01-01

    food chain has on producers and their families, an analysis was conducted of the use of the Sustainable Livelihoods Approach (SLA). The SLA provides a holistic and integrative approach which researchers can use as the overriding frame for their research. The application of the approach is recommended...... as it enables us to maintain important elements of the sustainability vision, yet emphasises that a number of assets influence farmers' livelihoods and it maintains the focus on salience, legitimacy, and credibility in the research....

  11. Evaluating six soft approaches

    DEFF Research Database (Denmark)

    Sørensen, Lene Tolstrup; Vidal, Rene Victor Valqui

    2008-01-01

    The paper introduces and evaluates six soft approaches used in strategy development and planning. We take a planner's perspective on discussing the concepts of strategy development and planning. This means that we see strategy development and planning as learning processes based on Ackoff......, Strategic Option Development and Analysis, Strategic Choice Approach and Soft Systems Methodology. Evaluations of each methodology are carried out using a conceptual framework in which the organisation, the result, the process and the technology of the specific approach are taken into consideration. Using...... such a conceptual framework for evaluations of soft approaches increases the understanding of them, their transparency, and their usability in practice....

  12. Evaluating six soft approaches

    DEFF Research Database (Denmark)

    Sørensen, Lene Tolstrup; Vidal, Rene Victor Valqui

    2008-01-01

    's interactive planning principles to be supported by soft approaches in carrying out the principles in action. These six soft approaches are suitable forsupporting various steps of the strategy development and planning process. These are the SWOT analysis, the Future Workshop, the Scenario methodology......, Strategic Option Development and Analysis, Strategic Choice Approach and Soft Systems Methodology. Evaluations of each methodology are carried out using a conceptual framework in which the organisation, the result, the process and the technology of the specific approach are taken into consideration. Using...

  13. Evaluating Six Soft Approaches

    DEFF Research Database (Denmark)

    Sørensen, Lene Tolstrup; Valqui Vidal, René Victor

    2008-01-01

    's interactive planning principles to be supported by soft approaches in carrying out the principles in action. These six soft approaches are suitable forsupporting various steps of the strategy development and planning process. These are the SWOT analysis, the Future Workshop, the Scenario methodology......, Strategic Option Development and Analysis, Strategic Choice Approach and Soft Systems Methodology. Evaluations of each methodology are carried out using a conceptual framework in which the organisation, the result, the process and the technology of the specific approach are taken into consideration. Using...

  14. Evaluating six soft approaches

    DEFF Research Database (Denmark)

    Sørensen, Lene; Vidal, Rene Victor Valqui

    2006-01-01

    ’s interactive planning principles to be supported by soft approaches in carrying out the principles in action. These six soft approaches are suitable for supporting various steps of the strategy development and planning process. These are the SWOT analysis, the Future Workshop, the Scenario methodology......, Strategic Option Development and Analysis, Strategic Choice Approach and Soft Systems Methodology. Evaluations of each methodology are carried out using a conceptual framework in which the organisation, the result, the process and the technology of the specific approach are taken into consideration. Using...

  15. A Comparison on the Audiolingual Approach and the Communicative Approach

    Institute of Scientific and Technical Information of China (English)

    代海娜

    2015-01-01

    Audiolingual approach and communicative approach are two important approaches in language teaching.In this paper,some differences and both advantages and diadvantages will be discussed.Thus,to conduct the important usage of approachs in language teaching.

  16. Modular Approach for Ethics

    Science.gov (United States)

    Wyne, Mudasser F.

    2010-01-01

    It is hard to define a single set of ethics that will cover an entire computer users community. In this paper, the issue is addressed in reference to code of ethics implemented by various professionals, institutes and organizations. The paper presents a higher level model using hierarchical approach. The code developed using this approach could be…

  17. INTERDISCIPLINARY APPROACH TO TEACHING

    OpenAIRE

    N.A. Sevryuk

    2014-01-01

    Educational transformation in Russia allows using new methods in teaching and learning. One of which is the interdisciplinary approach. The article describes the definition of the interdisciplinary approach, shows the reasons why to teach with it, and explains the advantages of using it and how it helps students advance their thinking, cognitive development and other abilities. It also gives some interdisciplinary examples.

  18. The Strategies Instructional Approach.

    Science.gov (United States)

    Deshler, Donald D.; Lenz, B. Keith

    1989-01-01

    The strategies instructional approach developed at the University of Kansas Institute for Research in Learning Disabilities is described. The approach teaches students strategies in the academic, social, motivational, and executive functioning areas that will enable students to meet content learning demands and modifies instructional environments…

  19. Complementary Health Approaches

    Science.gov (United States)

    ... back pain, neck pain, and joint pain or stiffness. NIH Research and Information on Complementary Health Approaches The lead agency at NIH for scientific research on complementary health approaches is the National Center for Complementary and Integrative Health (NCCIH). You can ...

  20. The Geodynamic Approach

    DEFF Research Database (Denmark)

    Steenfelt, Jørgen S.; Ibsen, Lars Bo

    1996-01-01

    The Danish National lecture: The Geodynamic approach - problem or possibility? - mirrors the authors involvement in projects and research focusing on the impact of the geodynamic approach. The lecture discusses the why and how of some of the geotechnical anomalies and the differences in traditional...

  1. The TLC Approach.

    Science.gov (United States)

    Welker, William A.

    2002-01-01

    Notes how the author has developed the Teaching and Learning Cues (TLC) approach, an offspring of textbook organizational patterns instruction that stresses the significance of certain words and phrases in reading. Concludes that with the TLC approach, students learn to appreciate the important role cue words and phrases play in understanding…

  2. Approaches to understand culture

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard; Rauner, Felix

    1996-01-01

    Different approaches to understand the concept ofculture are presented and evaluated. The author'sconcept of culture is defined. Different aspectsof the concept are discussed.......Different approaches to understand the concept ofculture are presented and evaluated. The author'sconcept of culture is defined. Different aspectsof the concept are discussed....

  3. Life Span Developmental Approach

    Directory of Open Access Journals (Sweden)

    Ali Eryilmaz

    2011-03-01

    Full Text Available The Life Span Developmental Approach examines development of individuals which occurs from birth to death. Life span developmental approach is a multi-disciplinary approach related with disciplines like psychology, psychiatry, sociology, anthropology and geriatrics that indicates the fact that development is not completed in adulthood, it continues during the life course. Development is a complex process that consists of dying and death. This approach carefully investigates the development of individuals with respect to developmental stages. This developmental approach suggests that scientific disciplines should not explain developmental facts only with age changes. Along with aging, cognitive, biological, and socioemotional development throughout life should also be considered to provide a reasonable and acceptable context, guideposts, and reasonable expectations for the person. There are three important subjects whom life span developmental approach deals with. These are nature vs nurture, continuity vs discontinuity, and change vs stability. Researchers using life span developmental approach gather and produce knowledge on these three most important domains of individual development with their unique scientific methodology.

  4. Revitalizing the setting approach

    DEFF Research Database (Denmark)

    Bloch, Paul; Toft, Ulla; Reinbach, Helene Christine;

    2014-01-01

    BackgroundThe concept of health promotion rests on aspirations aiming at enabling people to increase control over and improve their health. Health promotion action is facilitated in settings such as schools, homes and work places. As a contribution to the promotion of healthy lifestyles, we have.......DiscussionThe supersetting approach is a further development of the setting approach in which the significance of integrated and coordinated actions together with a participatory approach are emphasised and important principles are specified, all of which contribute to the attainment of synergistic effects and sustainable.......SummaryThe supersetting approach is a relevant and useful conceptual framework for developing intervention-based initiatives for sustainable impact in community health promotion. It strives to attain synergistic effects from activities that are carried out in multiple settings in a coordinated manner. The supersetting...

  5. Stakeholders: main approaches

    OpenAIRE

    Patrícia Mattos de Barros Schiavoni; Mário César Barreto Moraes; Alice Carneiro de Castro; Jair Nascimento Santos

    2013-01-01

    Every time organizations need adaptations to stay alive. We consider the analysis of their external environment an essential tool in this adaptive process, in particular, know your stakeholders. This article aims to present different approaches to organizational stakeholders, contributing concurrently with academia and companies who choose to analyze and act on its stakeholders, and possibly have a prominent market. We highlight the approach of stakeholder management, Edward Freeman, the mode...

  6. APPROACHES TO CORPORATE GOVERNANCE

    OpenAIRE

    Hines, Christine A.

    2009-01-01

    This paper explores the question ?what is corporate governance?? It examines dominant theoretical approaches to the subject, and reviews influential legislative attempts to address the area in the United States as well as the United Kingdom. Inconsistencies between theoretical approaches to the subject and practical frameworks will be discussed, along with the implications of current frameworks in the US and UK. It will be concluded that legislative reform ought to address the dynamic nature ...

  7. Sustainable fashion: New approaches

    OpenAIRE

    Niinimäki, Kirsi (editor)

    2013-01-01

    This publication is intended to be used as a source of inspiration for designers and companies, and all stakeholders whose interest lies in the area of sustainable fashion. While the strategies for sustainability are complex and approaches are many, this publication presents only a few ways to approach sustainable fashion. I hope the publication offers inspiration on how to make positive change in current practices and how to effect new mindsets, creating transformative fashion. Theoretica...

  8. Theoretical Approaches to Coping

    Directory of Open Access Journals (Sweden)

    Sofia Zyga

    2013-01-01

    Full Text Available Introduction: Dealing with stress requires conscious effort, it cannot be perceived as equal to individual's spontaneous reactions. The intentional management of stress must not be confused withdefense mechanisms. Coping differs from adjustment in that the latter is more general, has a broader meaning and includes diverse ways of facing a difficulty.Aim: An exploration of the definition of the term "coping", the function of the coping process as well as its differentiation from other similar meanings through a literature review.Methodology: Three theoretical approaches of coping are introduced; the psychoanalytic approach; approaching by characteristics; and the Lazarus and Folkman interactive model.Results: The strategic methods of the coping approaches are described and the article ends with a review of the approaches including the functioning of the stress-coping process , the classificationtypes of coping strategies in stress-inducing situations and with a criticism of coping approaches.Conclusions: The comparison of coping in different situations is difficult, if not impossible. The coping process is a slow process, so an individual may select one method of coping under one set ofcircumstances and a different strategy at some other time. Such selection of strategies takes place as the situation changes.

  9. Personal Approaches to Career Planning.

    Science.gov (United States)

    DeMont, Billie; DeMont, Roger

    1983-01-01

    Identifies four approaches to career planning based on situational leadership theory: the network approach, self-help approach, engineering approach, and mentor approach. Guidelines for the selection of a planning method based on the nature of the work environment and personal preference are discussed. (JAC)

  10. Technical approach document

    Energy Technology Data Exchange (ETDEWEB)

    1989-12-01

    The Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, Public Law 95-604 (PL95-604), grants the Secretary of Energy the authority and responsibility to perform such actions as are necessary to minimize radiation health hazards and other environmental hazards caused by inactive uranium mill sites. This Technical Approach Document (TAD) describes the general technical approaches and design criteria adopted by the US Department of Energy (DOE) in order to implement remedial action plans (RAPS) and final designs that comply with EPA standards. It does not address the technical approaches necessary for aquifer restoration at processing sites; a guidance document, currently in preparation, will describe aquifer restoration concerns and technical protocols. This document is a second revision to the original document issued in May 1986; the revision has been made in response to changes to the groundwater standards of 40 CFR 192, Subparts A--C, proposed by EPA as draft standards. New sections were added to define the design approaches and designs necessary to comply with the groundwater standards. These new sections are in addition to changes made throughout the document to reflect current procedures, especially in cover design, water resources protection, and alternate site selection; only minor revisions were made to some of the sections. Sections 3.0 is a new section defining the approach taken in the design of disposal cells; Section 4.0 has been revised to include design of vegetated covers; Section 8.0 discusses design approaches necessary for compliance with the groundwater standards; and Section 9.0 is a new section dealing with nonradiological hazardous constituents. 203 refs., 18 figs., 26 tabs.

  11. Technical approach document

    International Nuclear Information System (INIS)

    The Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, Public Law 95-604 (PL95-604), grants the Secretary of Energy the authority and responsibility to perform such actions as are necessary to minimize radiation health hazards and other environmental hazards caused by inactive uranium mill sites. This Technical Approach Document (TAD) describes the general technical approaches and design criteria adopted by the US Department of Energy (DOE) in order to implement remedial action plans (RAPS) and final designs that comply with EPA standards. It does not address the technical approaches necessary for aquifer restoration at processing sites; a guidance document, currently in preparation, will describe aquifer restoration concerns and technical protocols. This document is a second revision to the original document issued in May 1986; the revision has been made in response to changes to the groundwater standards of 40 CFR 192, Subparts A--C, proposed by EPA as draft standards. New sections were added to define the design approaches and designs necessary to comply with the groundwater standards. These new sections are in addition to changes made throughout the document to reflect current procedures, especially in cover design, water resources protection, and alternate site selection; only minor revisions were made to some of the sections. Sections 3.0 is a new section defining the approach taken in the design of disposal cells; Section 4.0 has been revised to include design of vegetated covers; Section 8.0 discusses design approaches necessary for compliance with the groundwater standards; and Section 9.0 is a new section dealing with nonradiological hazardous constituents. 203 refs., 18 figs., 26 tabs

  12. Homogenization approach in engineering

    International Nuclear Information System (INIS)

    Homogenization is an approach which studies the macrobehavior of a medium by its microproperties. Problems with a microstructure play an essential role in such fields as mechanics, chemistry, physics, and reactor engineering. Attention is concentrated on a simple specific model problem to illustrate results and problems typical of the homogenization approach. Only the diffusion problem is treated here, but some statements are made about the elasticity of composite materials. The differential equation is solved for linear cases with and without boundaries and for the nonlinear case. 3 figures, 1 table

  13. Approaching electrical tomography

    Directory of Open Access Journals (Sweden)

    P. L. Cosentino

    2000-06-01

    Full Text Available A general approach to electrical tomography is here described, based on the distribution of the experimental data to the set of voxels in which the subsoil has been divided. This approach utilizes the sensitivity coefficients as factors of the convolution procedure to execute the back projection of the data, to obtain the 3D pictures of the subsoil. A subsequent probabilistic filtering technique is described to improve the pictures in view of sharp boundary models. Some models are finally presented, mostly regarding cubic buried anomalies as well as pipe-shaped and L-shaped anomalies.

  14. Financial Management: An Organic Approach

    Science.gov (United States)

    Laux, Judy

    2013-01-01

    Although textbooks present corporate finance using a topical approach, good financial management requires an organic approach that integrates the various assignments financial managers confront every day. Breaking the tasks into meaningful subcategories, the current article offers one approach.

  15. Approaches to acceptable risk

    International Nuclear Information System (INIS)

    Several alternative approaches to address the question open-quotes How safe is safe enough?close quotes are reviewed and an attempt is made to apply the reasoning behind these approaches to the issue of acceptability of radiation exposures received in space. The approaches to the issue of the acceptability of technological risk described here are primarily analytical, and are drawn from examples in the management of environmental health risks. These include risk-based approaches, in which specific quantitative risk targets determine the acceptability of an activity, and cost-benefit and decision analysis, which generally focus on the estimation and evaluation of risks, benefits and costs, in a framework that balances these factors against each other. These analytical methods tend by their quantitative nature to emphasize the magnitude of risks, costs and alternatives, and to downplay other factors, especially those that are not easily expressed in quantitative terms, that affect acceptance or rejection of risk. Such other factors include the issues of risk perceptions and how and by whom risk decisions are made

  16. Approaches to acceptable risk

    Energy Technology Data Exchange (ETDEWEB)

    Whipple, C.

    1997-04-30

    Several alternative approaches to address the question {open_quotes}How safe is safe enough?{close_quotes} are reviewed and an attempt is made to apply the reasoning behind these approaches to the issue of acceptability of radiation exposures received in space. The approaches to the issue of the acceptability of technological risk described here are primarily analytical, and are drawn from examples in the management of environmental health risks. These include risk-based approaches, in which specific quantitative risk targets determine the acceptability of an activity, and cost-benefit and decision analysis, which generally focus on the estimation and evaluation of risks, benefits and costs, in a framework that balances these factors against each other. These analytical methods tend by their quantitative nature to emphasize the magnitude of risks, costs and alternatives, and to downplay other factors, especially those that are not easily expressed in quantitative terms, that affect acceptance or rejection of risk. Such other factors include the issues of risk perceptions and how and by whom risk decisions are made.

  17. Salt repository design approach

    International Nuclear Information System (INIS)

    This paper presents a summary discussion of the approaches that have been and will be taken in design of repository facilities for use with disposal of radioactive wastes in salt formations. Since specific sites have yet to be identified, the discussion is at a general level, supplemented with illustrative examples where appropriate. 5 references, 1 figure

  18. 12th CIFIT Approaches

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    CIFIT, standing for China International Fair for Investment and Trade, approved by the State Council of the People’s Republic of China, hold on September 8-11 every year in the city of Xiamen, China. In the year of 2008, the days for the 12th CIFIT approaches closely, a series of preparation have been on the way.

  19. RFID: Dynamic Surveillance Approach

    Directory of Open Access Journals (Sweden)

    Indraveer Singh

    2010-05-01

    Full Text Available Most of the modern security and monitoring domain is based upon Camera based Surveillance Architecture. Prison cells, corporate offices, government buildings, stock market, supermarkets etc all the seats utilize this structure in core. Most CCTV systems are used for surveillance which can include security monitoring, spying or for safety monitoring purposes. Although this system has been quite popular being affordable and visually administrable, it is no exception to improvements and up gradation. Thus in this paper we have come up with efficient proposals to upgrade the approach for Camera based Surveillance Architecture for security and Administration. This renewed approach is essentially based upon RFID technology where we are utilizing RFID tags and their readers as basic components. Unlike Camera-based surveillance, RFID-based approach can monitor and administer a quarter not only within some region of visibility but can efficiently do the same for locating the individuality (through Dynamic Surveillance as explained further. This approach emphasizes not only on overcoming the demerits of observation-based supervision, but it presents easier and effective monitoring methodologies using radio waves and their usable features in security and administration for areas with consumer pour out.

  20. Adopting a Pluricentric Approach

    Science.gov (United States)

    van Kerckvoorde, Colette

    2012-01-01

    This article argues for a "D-A-CH" approach, which stands for Germany (D), Austria (A), and Switzerland (CH), in language classes from the introductory level on. I begin by tracing the emergence and development of distinct Standard Swiss and Austrian German varieties. I then discuss marketing efforts for Swiss and Austrian German, and…

  1. Functionalized polymer film surfaces via surface-initiated atom transfer radical polymerization

    International Nuclear Information System (INIS)

    The ability to manipulate and control the surface properties of polymer films, without altering the substrate properties, is crucial to their wide-spread applications. In this work, a simple one-step method for the direct immobilization of benzyl chloride groups (as the effective atom transfer radical polymerization (ATRP) initiators) on the polymer films was developed via benzophenone-induced coupling of 4-vinylbenzyl chloride (VBC). Polyethylene (PE) and nylon films were selected as examples of polymer films to illustrate the functionalization of film surfaces via surface-initiated ATRP. Functional polymer brushes of (2-dimethylamino)ethyl methacrylate, sodium 4-styrenesulfonate, 2-hydroxyethyl methacrylate and glycidyl methacrylate, as well as their block copolymer brushes, have been prepared via surface-initiated ATRP from the VBC-coupled PE or nylon film surfaces. With the development of a simple approach to the covalent immobilization of ATRP initiators on polymer film surfaces and the inherent versatility of surface-initiated ATRP, the surface functionality of polymer films can be precisely tailored. - Highlights: ► Atom transfer radical polymerization initiators were simply immobilized. ► Different functional polymer brushes were readily prepared. ► Their block copolymer brushes were also readily prepared

  2. Domain Approach: An Alternative Approach in Moral Education

    Science.gov (United States)

    Vengadasalam, Chander; Mamat, Wan Hasmah Wan; Mail, Fauziah; Sudramanian, Munimah

    2014-01-01

    This paper discusses the use of the domain approach in moral education in an upper secondary school in Malaysia. Moral Education needs a creative and an innovative approach. Therefore, a few forms of approaches are used in the teaching-learning of Moral Education. This research describes the use of domain approach which comprises the moral domain…

  3. Preparation of (Ba,Sr)TiO{sub 3}-polystrene core-shell nanoparticles by solvent-free surface-initiated atom transfer radical polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Yang Xiaowei [State Key Laboratory of Materials-Oriented Chemical Engineering, School of Materials Science and Engineering, Nanjing University of Technology, 5 New model Road, Nanjing 210009 (China); Zeng Yanwei, E-mail: zengyanwei@tom.com [State Key Laboratory of Materials-Oriented Chemical Engineering, School of Materials Science and Engineering, Nanjing University of Technology, 5 New model Road, Nanjing 210009 (China); Cai Tongxiang; Hu Zhenxing [State Key Laboratory of Materials-Oriented Chemical Engineering, School of Materials Science and Engineering, Nanjing University of Technology, 5 New model Road, Nanjing 210009 (China)

    2012-07-15

    The polystyrene shells have been successfully grown on the barium strontium titanate (BST) nanocrystals, which were synthesized by microwave-activated glycothermal method, via a solvent-free surface-initiated atom transfer radical polymerization (SI-ATRP) after the 2-bromo-2-methylpropionic acid molecules (Br-MPA) were anchored at the surface of BST nanocrystals through ligand exchange with hydroxyl groups on their surfaces. These surface modified BST nanocrystals can then be perfectly dispersed in styrene monomer and act as macroinitiators for ATRP to yield BST-PS core-shell structured nanoparticles, which endow the BST nanocrystals with exceptionally good dispersibility and stability in hydrophobic solvents. The BST-PS core-shell structures were characterized by X-ray diffraction (XRD) technique and transmission electron microscopy (TEM). Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (Raman), differential scanning calorimetry (DSC) and gel permeation chromatography were also employed to probe the Br-MPA and PS on the BST nanocrystals. It has been shown that after the BST nanocrystals are surface-modified with Br-MPA, the polymerization of styrene can steadily occur at the surface of BST nanocrystals to form a uniform polystyrene shell and its thickness can reach {approx}10 nm when the polymerization reaction is extended to 36 h, while no changes are found to take place with the BST nanocrystals. Compared with typical high molecular weight PS (M{sub n} = 6700), the as-obtained PS possess a relatively low molecular weight (M{sub n} = 5473) and a lower glass transition temperature (T{sub g} {approx} 93 Degree-Sign C). The research results demonstrate a viable strategy for the preparation of polymer-coated functional metal oxides nanocrystals, potentially useful in biological and nanoelectronic applications.

  4. Preparation of (Ba,Sr)TiO3-polystrene core-shell nanoparticles by solvent-free surface-initiated atom transfer radical polymerization

    International Nuclear Information System (INIS)

    The polystyrene shells have been successfully grown on the barium strontium titanate (BST) nanocrystals, which were synthesized by microwave-activated glycothermal method, via a solvent-free surface-initiated atom transfer radical polymerization (SI-ATRP) after the 2-bromo-2-methylpropionic acid molecules (Br-MPA) were anchored at the surface of BST nanocrystals through ligand exchange with hydroxyl groups on their surfaces. These surface modified BST nanocrystals can then be perfectly dispersed in styrene monomer and act as macroinitiators for ATRP to yield BST-PS core-shell structured nanoparticles, which endow the BST nanocrystals with exceptionally good dispersibility and stability in hydrophobic solvents. The BST-PS core-shell structures were characterized by X-ray diffraction (XRD) technique and transmission electron microscopy (TEM). Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (Raman), differential scanning calorimetry (DSC) and gel permeation chromatography were also employed to probe the Br-MPA and PS on the BST nanocrystals. It has been shown that after the BST nanocrystals are surface-modified with Br-MPA, the polymerization of styrene can steadily occur at the surface of BST nanocrystals to form a uniform polystyrene shell and its thickness can reach ∼10 nm when the polymerization reaction is extended to 36 h, while no changes are found to take place with the BST nanocrystals. Compared with typical high molecular weight PS (Mn = 6700), the as-obtained PS possess a relatively low molecular weight (Mn = 5473) and a lower glass transition temperature (Tg ∼ 93 °C). The research results demonstrate a viable strategy for the preparation of polymer-coated functional metal oxides nanocrystals, potentially useful in biological and nanoelectronic applications.

  5. Facile Synthesis of Well-Defined MDMO-PPV Containing (TriBlock—Copolymers via Controlled Radical Polymerization and CuAAC Conjugation

    Directory of Open Access Journals (Sweden)

    Neomy Zaquen

    2015-02-01

    Full Text Available A systematic investigation into the chain transfer polymerization of the so-called radical precursor polymerization of poly(p-phenylene vinylene (PPV materials is presented. Polymerizations are characterized by systematic variation of chain transfer agent (CTA concentration and reaction temperature. For the chain transfer constant, a negative activation energy of −12.8 kJ·mol−1 was deduced. Good control over molecular weight is achieved for both the sulfinyl and the dithiocarbamate route (DTC. PPVs with molecular weights ranging from thousands to ten thousands g·mol−1 were obtained. To allow for a meaningful analysis of the CTA influence, Mark–Houwink–Kuhn–Sakurada (MHKS parameters were determined for conjugated MDMO-PPV ([2-methoxy-5-(3',7'-dimethyloctyloxy]-1,4-phenylenevinylene to α = 0.809 and k = 0.00002 mL·g−1. Further, high-endgroup fidelity of the CBr4-derived PPVs was proven via chain extension experiments. MDMO-PPV-Br was successfully used as macroinitiator in atom transfer radical polymerization (ATRP with acrylates and styrene. A more polar PPV counterpart was chain extended by an acrylate in single-electron transfer living radical polymerization (SET-LRP. In a last step, copper-catalyzed azide alkyne cycloaddition (CuAAC was used to synthesize block copolymer structures. Direct azidation followed by macromolecular conjugation showed only partial success, while the successive chain extension via ATRP followed by CuAAC afforded triblock copolymers of the poly(p-phenylene vinylene-block-poly(tert-butyl acrylate-block-poly(ethylene glycol (PPV-b-PtBuA-b-PEG.

  6. Sociocultural approach to textbook

    Directory of Open Access Journals (Sweden)

    Pešić Jelena M.

    2005-01-01

    Full Text Available The aim of this paper is to present an overview of textbook research at the Institute of psychology, intended to postulate socio-cultural approach to textbook. Shifting the textbook from classical pedagogical-psychological context into the broader and more inspiring cultural context, has led to the conceptualization of textbook as a cultural-supportive system of individual development. We consider firstly, the theoretical background of this conception, founded in Vygotskian idea of cultural mediation of development and then, its operationalization through the concept of cultural-supportive tools. The transfer from theory to practice is presented through the most important practical implications, such as defining the genre specificities of textbook and principles of educational design of textbooks. As a distinctive issue, we also consider the way this approach to textbook (theoretical articulation, analytical concepts, and practical implications contributes to development of socio-cultural paradigm in psychology.

  7. Radiolab - three different approaches

    DEFF Research Database (Denmark)

    Lønstrup, Ansa

    2012-01-01

    Radiolab – three different approaches The three papers in this ‘suite’ have a special background and context. At the 2010 conference SoundActs in Aarhus the three panellists were each given the task to provide a paper with an analysis of the same sound object, thus exhibiting and contrasting...... contextual investigation. This object was chosen for several reasons. First of all, it is brief (less than 17 seconds), which meant that it was possible to make a detailed analysis; at the same time, though, it is relatively complex, which means that it can accommodate three different analyses. It is a sound...... object with a global audience, taken from one of the most popular podcasts worldwide, accessible on the internet. Finally, it is a piece of functional sound design, rather than a work of art, which raises the question of context more clearly. The result is three rather different approaches: 1) a process...

  8. Dimensional Approach in Psychiatry

    Directory of Open Access Journals (Sweden)

    Osman Ozdemir

    2012-09-01

    Full Text Available In psychiatry there is a traditional categorical conception stating that several disorders like schizophrenia and bipolar disorder have distinct etiologies. On the other hand, dimensional approach claims that these entities are actually the same disorder reflecting different clinical aspects of same mental disorder in the course of time. ICD and DSM classifications are based on separate categories of different mental disorders. Howewer, it is quite difficult to consider a mental disorder as a discrete entity that has absolute boundaries from other disorders. There are patients manifesting symptoms of two or more categories but do not fulfill all diagnostic criteria for any mental disorder. Dimensional approach handles the psychopathology as a continuing process and establish the patients to the different ongoing points. According to this view, in fact, multiple diagnosis reflect dimensions of the same disease.

  9. Approaches to nuclear friction

    International Nuclear Information System (INIS)

    This review summarises the present knowledge of experimental information on friction effects in nuclear reactions and describes the theoretical approaches in detail. The experimental evidence for nuclear friction stems from reactions where large-scale collective motion is involved, that is fission, deep inelastic heavy-ion scattering and giant excitations. The various theories and models employed are based on the concept that friction, damping and viscosity in nuclei are due to an irreversible flow of energy (and/or linear or angular momentum) from collective to intrinsic motion. They cover the range from classical mechanics with frictional forces and its formal quantisations over viscous fluid dynamics to microscopic models of intrinsic excitations and statistical descriptions of collisions between nucleons or between nucleons with nuclear boundary. Other approaches are mentioned and a few unresolved questions are put forward at the end in order to stimulate further research in this new and interesting subject. 203 references. (author)

  10. Thermodynamics an engineering approach

    CERN Document Server

    Cengel, Yunus A

    2014-01-01

    Thermodynamics, An Engineering Approach, eighth edition, covers the basic principles of thermodynamics while presenting a wealth of real-world engineering examples so students get a feel for how thermodynamics is applied in engineering practice. This text helps students develop an intuitive understanding by emphasizing the physics and physical arguments. Cengel and Boles explore the various facets of thermodynamics through careful explanations of concepts and use of numerous practical examples and figures, having students develop necessary skills to bridge the gap between knowledge and the confidence to properly apply their knowledge. McGraw-Hill is proud to offer Connect with the eighth edition of Cengel/Boles, Thermodynamics, An Engineering Approach. This innovative and powerful new system helps your students learn more efficiently and gives you the ability to assign homework problems simply and easily. Problems are graded automatically, and the results are recorded immediately. Track individual stude...

  11. Towards a Tectonic Approach

    DEFF Research Database (Denmark)

    Hvejsel, Marie Frier; Kirkegaard, Poul Henning; Mortensen, Sophie Bondgaard

    2015-01-01

    Given the increasing environmental and legislative demands to reduce energy consumption, not only new constructions but also the existing urban fabric is about to change radically in the coming decades. Existing buildings cannot simply be restored but must undergo a transformation to comply with ...... the building envelope as an aesthetic ‘gesture’, this paper discusses the architectural challenges related to energy renovation in a Danish context and tectonic design method as an approach to these challenges in everyday practice....

  12. Sociocultural approach to textbook

    OpenAIRE

    Pešić Jelena M.

    2005-01-01

    The aim of this paper is to present an overview of textbook research at the Institute of psychology, intended to postulate socio-cultural approach to textbook. Shifting the textbook from classical pedagogical-psychological context into the broader and more inspiring cultural context, has led to the conceptualization of textbook as a cultural-supportive system of individual development. We consider firstly, the theoretical background of this conception, founded in Vygotskian idea of cultural m...

  13. Cultural Approaches to Parenting

    OpenAIRE

    Bornstein, Marc H.

    2012-01-01

    This article first introduces some main ideas behind culture and parenting and next addresses philosophical rationales and methodological considerations central to cultural approaches to parenting, including a brief account of a cross-cultural study of parenting. It then focuses on universals, specifics, and distinctions between form (behavior) and function (meaning) in parenting as embedded in culture. The article concludes by pointing to social policy implications as well as future directio...

  14. Breakfast: a multidisciplinary approach

    OpenAIRE

    Affinita, Antonio; Catalani, Loredana; Cecchetto, Giovanna; De Lorenzo, Gianfranco; Dilillo, Dario; Donegani, Giorgio; Fransos, Lucia; Lucidi, Fabio; Mameli, Chiara; Manna, Elisa; Marconi, Paolo; Mele, Giuseppe; Minestroni, Laura; Montanari, Massimo; Morcellini, Mario

    2013-01-01

    Background The role of breakfast as an essential part of an healthy diet has been only recently promoted even if breakfast practices were known since the Middle Age. The growing scientific evidences on this topic are extremely sector-based nevertheless breakfast could be regarded from different point of views and from different expertises. This approach, that take into account history, sociology, anthropology, medicine, psychology and pedagogy, is useful to better understand the value of this...

  15. The Branding Management Approaches

    Institute of Scientific and Technical Information of China (English)

    YAKOUBI; Mohamed Lamine

    2014-01-01

    [Abstract]We wil try to present,through the display of the various branding concepts and theories, the different branding management approaches.This wil present the different visions of the discipline depending on the author to try and demonstrate their differences,at first, and their complementarities at last to help the different branding management practitioners (brand managers,marketing managers,advertisers,media-planners……) apprehend the right brand positioning strategy to engage.

  16. Grounded Theory approach

    OpenAIRE

    Ali Rabbani Khorasghani; Mohammad Abbaszadeh

    2010-01-01

    AbstractAccording to social changes in global level, social scientist introduced new theories to explanation of socialphenomena. According to appearance new theories, research methods have changed. The Idea is that,Simultaneity with Appearance post positivist theories, research approaches such a grounded theory hasestablished. This method, acts in the base of qualitative methods and use systematic complex of multipleProcedures to gathering data for theory development upon induction. This meth...

  17. Approaching Service Innovation Patterns

    OpenAIRE

    Nagy, Andrea

    2013-01-01

    The present paper aims at analyzing the types of innovation in the field of services. First, the concept of innovation is defined and second, field literature is reviewed from the perspective of service innovation. The main types of innovation are identified based on several attempts at defining innovation, the most notable being Schumpeter’s. Thus, it is possible to approach concepts such as product and process innovation, incremental and radical innovation. Another aim has been to regard se...

  18. Multiple correlation function approach

    OpenAIRE

    Grebenkov, Denis S.

    2016-01-01

    The multiple correlation function approach is briefly presented and applied to investigate spin-echo signal attenuation due to restricted diffusion in simple geometries (slab, cylinder, and sphere) in the presence of surface relaxation. Exact and explicit representations for the zeroth and second moments of the total phase accumulated by diffusing spins are derived by using the Laplace transform summation technique. Within the Gaussian phrase approximation, these two moments determine the ...

  19. The Knowledge Governance Approach

    OpenAIRE

    Nicolai J. Foss

    2005-01-01

    An attempt is made to characterize a "knowledge governance approach" as a distinctive, emerging field that cuts across the fields of knowledge management, organisation studies, strategy and human resource management. Knowledge governance is taken up with how the deployment of administrative apparatus influences knowledge processes, such as sharing, retaining and creating knowledge. It insists on clear behavioural foundations, adopts an economizing perspective and examines efficient alignment ...

  20. Communicative Approach: Some Misapprehensions

    Directory of Open Access Journals (Sweden)

    Mohammad Nurul Islam

    2012-01-01

    Full Text Available Though Communicative Language Teaching (CLT is acknowledged by the National Curriculum & Textbook Board (NCTB and many English teachers as one of the most effective approaches in English language teaching in Bangladesh, there are still a number of misapprehensions about it. By comparing Johnstone; Sato and Kleinsasser and Thompson as well as Spada, this article focuses on four of the main misapprehensions, which are usually held by the language teachers and researchers.

  1. Case Base Maintenance Approach.

    OpenAIRE

    Haouchine, Mohamed-Karim; Chebel-Morello, Brigitte; Zerhouni, Noureddine

    2007-01-01

    Case base Maintenance is an active Case Based Reasoning research area. The main stream focuses on the method for reducing the size of the case-base while maintaining case-base competence. This paper gives an overview of these works, and proposes a case deletion strategy based on competence criteria using a novel approach. The proposed method, even if inspired from existing literature, combines an algorithm with a Competence Metric (CM). A series of tests are conducted using two standards data...

  2. Parsec's astrometry direct approaches .

    Science.gov (United States)

    Andrei, A. H.

    Parallaxes - and hence the fundamental establishment of stellar distances - rank among the oldest, keyest, and hardest of astronomical determinations. Arguably amongst the most essential too. The direct approach to obtain trigonometric parallaxes, using a constrained set of equations to derive positions, proper motions, and parallaxes, has been labeled as risky. Properly so, because the axis of the parallactic apparent ellipse is smaller than one arcsec even for the nearest stars, and just a fraction of its perimeter can be followed. Thus the classical approach is of linearizing the description by locking the solution to a set of precise positions of the Earth at the instants of observation, rather than to the dynamics of its orbit, and of adopting a close examination of the never many points available. In the PARSEC program the parallaxes of 143 brown dwarfs were aimed at. Five years of observation of the fields were taken with the WIFI camera at the ESO 2.2m telescope, in Chile. The goal is to provide a statistically significant number of trigonometric parallaxes to BD sub-classes from L0 to T7. Taking advantage of the large, regularly spaced, quantity of observations, here we take the risky approach to fit an ellipse in ecliptical observed coordinates and derive the parallaxes. We also combine the solutions from different centroiding methods, widely proven in prior astrometric investigations. As each of those methods assess diverse properties of the PSFs, they are taken as independent measurements, and combined into a weighted least-square general solution.

  3. APPROACHES FOR SUSTAINABLE MANUFACTURING

    Institute of Scientific and Technical Information of China (English)

    G(U)NTHER Seliger; SEBASTIAN Kernbaum; MARCO Zettl

    2007-01-01

    Sustainable development is a holistic approach harmonizing ecological, economical and socio-political needs with respect to the superior objective of enhancing human living standards. Thereby the availability of natural resources and the conservation of the ecosystems have to be considered that future generations have the possibility to meet their own needs. A long-term economical development demands the transition from a source-sink economy to a cycle economy as a result of limited resources, limited environmental capacities to absorb waste and emissions as well as increasing needs of a growing population. A reference model for sustainability in manufacturing is presented and used to illustrate sustainable approaches with respect to management, technology, process and product. Adaptation of products and components is a vital element for supporting efficient reuse of products and components. Consequently adaptation contributes to the ambitious goals of sustainability. Technological enablers for adaptation as modularity, information and communication technology are exemplarily introduced. Moreover, approaches for disseminating knowledge in sustainability are given.

  4. Enteral approaches in malabsorption.

    Science.gov (United States)

    Avitzur, Yaron; Courtney-Martin, Glenda

    2016-04-01

    Enteral autonomy and freedom from parenteral nutrition dependency is the ultimate therapeutic goal in children with intestinal failure. This can be achieved following attainment of bowel adaptation in conditions such as short bowel syndrome. Enteral nutrition is a major therapeutic cornerstone in the management of children with intestinal failure. It promotes physiological development, bowel adaptation and enhances weaning from parenteral nutrition. The optimal method of delivery, type of nutrients, timing of initiation, promotion of feeds and transition to solid food in children with short bowel syndrome are debated. Lack of high quality human data hampers evidence based conclusions and impacts daily practices in the field. Clinical approaches and therapeutic decisions are regularly influenced by expert opinion and center practices. This review summarizes the physiological principles, medical evidence and practice recommendations on enteral nutrition approaches in short bowel syndrome and provides a practical framework for daily treatment of this unique group of patients. Oral and tube feeding, bolus and continuous feeding, type of nutrients, formulas, trace elements and solid food options are reviewed. Future collaborative multicenter, high quality clinical trials are needed to support enteral nutrition approaches in intestinal failure. PMID:27086892

  5. [Approaches to radial shaft].

    Science.gov (United States)

    Bartoníček, J; Naňka, O; Tuček, M

    2015-10-01

    In the clinical practice, radial shaft may be exposed via two approaches, namely the posterolateral Thompson and volar (anterior) Henry approaches. A feared complication of both of them is the injury to the deep branch of the radial nerve. No consensus has been reached, yet, as to which of the two approaches is more beneficial for the proximal half of radius. According to our anatomical studies and clinical experience, Thompson approach is safe only in fractures of the middle and distal thirds of the radial shaft, but highly risky in fractures of its proximal third. Henry approach may be used in any fracture of the radial shaft and provides a safe exposure of the entire lateral and anterior surfaces of the radius.The Henry approach has three phases. In the first phase, incision is made along the line connecting the biceps brachii tendon and the styloid process of radius. Care must be taken not to damage the lateral cutaneous nerve of forearm.In the second phase, fascia is incised and the brachioradialis identified by the typical transition from the muscle belly to tendon and the shape of the tendon. On the lateral side, the brachioradialis lines the space with the radial artery and veins and the superficial branch of the radial nerve running at its bottom. On the medial side, the space is defined by the pronator teres in the proximal part and the flexor carpi radialis in the distal part. The superficial branch of the radial nerve is retracted together with the brachioradialis laterally, and the radial artery medially.In the third phase, the attachment of the pronator teres is identified by its typical tendon in the middle of convexity of the lateral surface of the radial shaft. The proximal half of the radius must be exposed very carefully in order not to damage the deep branch of the radial nerve. Dissection starts at the insertion of the pronator teres and proceeds proximally along its lateral border in interval between this muscle and insertion of the supinator

  6. Peritonitis: laparoscopic approach

    Directory of Open Access Journals (Sweden)

    Agresta Ferdinando

    2006-03-01

    Full Text Available Abstract Background Laparoscopy has became as the preferred surgical approach to a number of different diseases because it allows a correct diagnosis and treatment at the same time. In abdominal emergencies, both components of treatment – exploration to identify the causative pathology and performance of an appropriate operation – can often be accomplished via laparoscopy. There is still a debate of peritonitis as a contraindication to this kind of approach. Aim of the present work is to illustrate retrospectively the results of a case-control experience of laparoscopic vs. open surgery for abdominal peritonitis emergencies carried out at our institution. Methods From January 1992 and January 2002 a total of 935 patients (mean age 42.3 ± 17.2 years underwent emergent and/or urgent surgery. Among them, 602 (64.3% were operated on laparoscopically (of whom 112 -18.7% – with peritonitis, according to the presence of a surgical team trained in laparoscopy. Patients with a history of malignancy, more than two previous major abdominal surgeries or massive bowel distension were not treated Laparoscopically. Peritonitis was not considered contraindication to Laparoscopy. Results The conversion rate was 23.2% in patients with peritonitis and was mainly due to the presence of dense intra-abdominal adhesions. Major complications ranged as high as 5.3% with a postoperative mortality of 1.7%. A definitive diagnosis was accomplished in 85.7% (96 pat. of cases, and 90.6% (87 of these patients were treated successfully by Laparoscopy. Conclusion Even if limited by its retrospective feature, the present experience let us to consider the Laparoscopic approach to abdominal peritonitis emergencies a safe and effective as conventional surgery, with a higher diagnostic yield and allows for lesser trauma and a more rapid postoperative recovery. Such features make Laparoscopy a challenging alternative to open surgery in the management algorithm for abdominal

  7. Approaches to Quantum Gravity

    Science.gov (United States)

    Oriti, Daniele

    2009-03-01

    Preface; Part I. Fundamental Ideas and General Formalisms: 1. Unfinished revolution C. Rovelli; 2. The fundamental nature of space and time G. 't Hooft; 3. Does locality fail at intermediate length scales R. Sorkin; 4. Prolegomena to any future quantum gravity J. Stachel; 5. Spacetime symmetries in histories canonical gravity N. Savvidou; 6. Categorical geometry and the mathematical foundations of quantum gravity L. Crane; 7. Emergent relativity O. Dreyer; 8. Asymptotic safety R. Percacci; 9. New directions in background independent quantum gravity F. Markopoulou; Questions and answers; Part II: 10. Gauge/gravity duality G. Horowitz and J. Polchinski; 11. String theory, holography and quantum gravity T. Banks; 12. String field theory W. Taylor; Questions and answers; Part III: 13. Loop Quantum Gravity T. Thiemann; 14. Covariant loop quantum gravity? E. LIvine; 15. The spin foam representation of loop quantum gravity A. Perez; 16. 3-dimensional spin foam quantum gravity L. Freidel; 17. The group field theory approach to quantum gravity D. Oriti; Questions and answers; Part IV. Discrete Quantum Gravity: 18. Quantum gravity: the art of building spacetime J. Ambjørn, J. Jurkiewicz and R. Loll; 19. Quantum Regge calculations R. Williams; 20. Consistent discretizations as a road to quantum gravity R. Gambini and J. Pullin; 21. The causal set approach to quantum gravity J. Henson; Questions and answers; Part V. Effective Models and Quantum Gravity Phenomenology: 22. Quantum gravity phenomenology G. Amelino-Camelia; 23. Quantum gravity and precision tests C. Burgess; 24. Algebraic approach to quantum gravity II: non-commutative spacetime F. Girelli; 25. Doubly special relativity J. Kowalski-Glikman; 26. From quantum reference frames to deformed special relativity F. Girelli; 27. Lorentz invariance violation and its role in quantum gravity phenomenology J. Collins, A. Perez and D. Sudarsky; 28. Generic predictions of quantum theories of gravity L. Smolin; Questions and

  8. Repository program licensing approach

    International Nuclear Information System (INIS)

    Yucca Mountain, Nevada is currently being studied by the US Department of Energy (DOE) as a potential site for a mined geologic repository for high-level nuclear waste. DOE has the responsibility to determine the suitability of the site and to develop a license application (LA) for authorization to construct the potential repository. If the site is suitable, the license application would be submitted to the US Nuclear Regulatory Commission (NRC). The repository program licensing approach is focused on the timely acquisition of information needed in licensing and the resolution of potential licensing issues with the NRC staff. Licensing involves an iterative process requiring refinements as data are acquired, analyzed, and evaluated. The repository licensing approach presented in this paper ensures that the information is available when needed to facilitate the licensing process. Identifying the information needed to evaluate compliance with the performance objectives in 10 CFR 60, monitoring the acquisition of such information, and developing a successful license application are integral elements of DOE's repository program licensing approach. Activities to characterize the site are being systematically conducted as planned in the Site Characterization Plan (SCP). In addition, DOE is implementing the issue resolution initiative, the license application annotated outline (LAAO) process, and interim licensability evaluations to update the early planning in the SCP and to focus site characterization, design, and performance assessment activities on the acquisition of information needed for a site suitability determination and licensing. Collectively, the issue resolution initiative, LAAO process, and interim licensability evaluations are key elements of a transition to the iterative process to answer the question: open-quotes When do we have enough data to support licensing?close quotes

  9. The collaboratory approach

    International Nuclear Information System (INIS)

    A open-quotes collaboratoryclose quotes has been defined as a center without walls, in which researchers can perform their work without regard to geographical location. To an increasing degree, engineering design and development is also taking the form of far-flung collaborations among divisions of a plant, subcontractors, university consultants and customers. It has long been recognized that quality engineering education presents the student with an environment that duplicates as much as possible that which the graduate will encounter in industry. To that end, it is important that engineering schools begin to introduce the collaboratory approach in its preparation, and even use it in delivery of subject matter to students

  10. Experimental approaches and applications

    CERN Document Server

    Crasemann, Bernd

    2013-01-01

    Atomic Inner-Shell Processes, Volume II: Experimental Approaches and Applications focuses on the physics of atomic inner shells, with emphasis on experimental aspects including the use of radioactive atoms for studies of atomic transition probabilities. Surveys of modern techniques of electron and photon spectrometry are also presented, and selected practical applications of inner-shell processes are outlined. Comprised of six chapters, this volume begins with an overview of the general principles underlying the experimental techniques that make use of radioactive isotopes for inner-sh

  11. URBAN POLITICS: KEY APPROACHES

    Directory of Open Access Journals (Sweden)

    Ledyaeva Ol'ga Mikhaylovna

    2012-10-01

    Full Text Available Several approaches that underlie urban politics are discussed in the paper. They include neo-liberalism, political economy discourse, elitist/pluralist debates, and postmodernism. The neoliberal approach focuses on the limited role of the state and individual responsibility. The legal framework protects both the rights and responsibilities of individuals and regulates the operation of the market. It is the market that fosters individual choices and provides goods and services by virtue of the processes which are flexible, efficient and transparent. The political economy approaches (regulation theory, public choice theory, neo-Marxism explain urban politics via the analysis of national and international economic processes and changes in contemporary capitalism. Changes in national and international economies determine what solutions are possible. The discourse has been influenced by the debate on globalization of capital and labour markets. Modern elitism and neopluralism are represented by theories of "growth machines" and "urban regimes". The former focuses on bargaining alliances between political and business leaders in order to manage the urban system and to promote its growth. The latter develops neopluralist explanations of power within local communities with an emphasis on the fragmented nature of the government where local authorities lack comprehensive governing powers. Postmodernism views the city as the site of the crisis of late capitalism which leads to segregation of neighbourhoods onto prosperous areas and ghettoes. In contrast to the modern city, the postmodern city is not defined by its industrial base; rather, it is determined by its consumerist environment of malls and museums, characterized by revivalist architecture. At the same time, the suburban shopping mall and a motorway network make nonsense of the idea of the city as a unique and well-defined space. These and other approaches encompass a wide spectrum of possibilities

  12. The Knowledge Governance Approach

    DEFF Research Database (Denmark)

    Foss, Nicolai

    2005-01-01

    apparatus influences knowledge processes, such as sharing, retaining and creating knowledge. It insists on clear behavioural foundations, adopts an economizing perspective and examines efficient alignment between knowledge transactions with diverse characteristics and governance structures and mechanisms...... with diverse capabilities of handling these transactions. Various open research issues that a knowledge governance approach may illuminate are sketched. Although knowledge governance draws clear inspiration from organizational economics and `rational' organization theory, it recognizes that knowledge...... represents various challenges to more `closed' social science disciplines, notably economics....

  13. Cognitive approaches to emotions.

    Science.gov (United States)

    Oatley, Keith; Johnson-Laird, P N

    2014-03-01

    Cognitive approaches offer clear links between how emotions are thought about in everyday life and how they are investigated psychologically. Cognitive researchers have focused on how emotions are caused when events or other people affect concerns and on how emotions influence processes such as reasoning, memory, and attention. Three representative cognitive theories of emotion continue to develop productively: the action-readiness theory, the core-affect theory, and the communicative theory. Some principles are common to them and divergences can be resolved by future research. Recent explanations have included how emotions structure social relationships, how they function in psychological illnesses, and how they are central to music and fiction. PMID:24389368

  14. An Approach to Cosmeceuticals.

    Science.gov (United States)

    Milam, Emily C; Rieder, Evan A

    2016-04-01

    The cosmeceutical industry is a multi-billion dollar, consumer-driven market. Products promise highly desirable anti-aging benefits, but are not subject to regulation. We present an introduction to cosmeceuticals for the general and cosmetic dermatologist, including definitions and explanations of key terms, an approach to the evidence base, a dissection of chamomile and green tea, two paradigmatic cosmeceutical products, and a window into the underlying psychology of this vast marketplace. J Drugs Dermatol. 2016;15(4):452-456. PMID:27050700

  15. Genetic approaches to somatosensation.

    OpenAIRE

    Abrahamsen, B.

    2008-01-01

    Three approaches to understanding peripheral pain pathways are described in this thesis. Cre-loxP technology has been used to delete genes specifically in specialised sensory neurons that respond to tissue damage (nociceptors). The sodium channel selective Nav1.8 promoter is used to drive Cre expression. I used a mouse expressing diphtheria toxin A-chain downstream of a floxed stop signal, crossed with the Nayl.8Cre mouse to delete all cells expressing this channel. This lead to massive cell ...

  16. Grounded Theory approach

    Directory of Open Access Journals (Sweden)

    Ali Rabbani Khorasghani

    2010-01-01

    Full Text Available AbstractAccording to social changes in global level, social scientist introduced new theories to explanation of socialphenomena. According to appearance new theories, research methods have changed. The Idea is that,Simultaneity with Appearance post positivist theories, research approaches such a grounded theory hasestablished. This method, acts in the base of qualitative methods and use systematic complex of multipleProcedures to gathering data for theory development upon induction. This method with characteristics as ifflexibility, reflexivity, has caused many of researchers used it. In the present article, we paid to introductionof grounded theory and its critics.

  17. Radiolab - three different approaches

    OpenAIRE

    Ola Stockfelt; Ansa Lønstrup; Torben Sangild

    2012-01-01

    The three papers in this ‘suite’ have a special background and context. At the 2010 conference SoundActs in Aarhus the three panellists were each given the task to provide a paper with an analysis of the same sound object, thus exhibiting and contrasting different scholarly approaches to sound studies. The object was selected by Torben Sangild, who was familiar with the chosen context: the signature of the US radio programme and podcast Radiolab. The two other participants did not know the co...

  18. HEDR modeling approach

    International Nuclear Information System (INIS)

    This report details the conceptual approaches to be used in calculating radiation doses to individuals throughout the various periods of operations at the Hanford Site. The report considers the major environmental transport pathways--atmospheric, surface water, and ground water--and projects and appropriate modeling technique for each. The modeling sequence chosen for each pathway depends on the available data on doses, the degree of confidence justified by such existing data, and the level of sophistication deemed appropriate for the particular pathway and time period being considered

  19. Approaching Service Innovation Patterns

    Directory of Open Access Journals (Sweden)

    Andrea NAGY

    2013-06-01

    Full Text Available The present paper aims at analyzing the types of innovation in the field of services. First, the concept of innovation is defined and second, field literature is reviewed from the perspective of service innovation. The main types of innovation are identified based on several attempts at defining innovation, the most notable being Schumpeter’s. Thus, it is possible to approach concepts such as product and process innovation, incremental and radical innovation. Another aim has been to regard service innovation as a standout type of innovation.

  20. The collaboratory approach

    Energy Technology Data Exchange (ETDEWEB)

    Peskin, A.M.

    1997-04-01

    A {open_quotes}collaboratory{close_quotes} has been defined as a center without walls, in which researchers can perform their work without regard to geographical location. To an increasing degree, engineering design and development is also taking the form of far-flung collaborations among divisions of a plant, subcontractors, university consultants and customers. It has long been recognized that quality engineering education presents the student with an environment that duplicates as much as possible that which the graduate will encounter in industry. To that end, it is important that engineering schools begin to introduce the collaboratory approach in its preparation, and even use it in delivery of subject matter to students.

  1. Approaches for Stereo Matching

    Directory of Open Access Journals (Sweden)

    Takouhi Ozanian

    1995-04-01

    Full Text Available This review focuses on the last decade's development of the computational stereopsis for recovering three-dimensional information. The main components of the stereo analysis are exposed: image acquisition and camera modeling, feature selection, feature matching and disparity interpretation. A brief survey is given of the well known feature selection approaches and the estimation parameters for this selection are mentioned. The difficulties in identifying correspondent locations in the two images are explained. Methods as to how effectively to constrain the search for correct solution of the correspondence problem are discussed, as are strategies for the whole matching process. Reasons for the occurrence of matching errors are considered. Some recently proposed approaches, employing new ideas in the modeling of stereo matching in terms of energy minimization, are described. Acknowledging the importance of computation time for real-time applications, special attention is paid to parallelism as a way to achieve the required level of performance. The development of trinocular stereo analysis as an alternative to the conventional binocular one, is described. Finally a classification based on the test images for verification of the stereo matching algorithms, is supplied.

  2. Diagnostic approaches for cholangiocarcinoma

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Cholangiocarcinomas arise from the epithelial cells of the bile ducts and are associated with poor prognosis. Despite new diagnostic approaches, the definite diagnosis of this malignancy continues to be challenging. Cholangiocarcinomas often grow longitudinally along the bile duct rather than in a radial direction. Thus, large tumor masses are frequently absent and imaging techniques, including ultrasound, CT, and MRI have only limited sensitivity. Tissue collection during endoscopic (ERCP) and/or percutaneous transhepatic (PTC) procedures are usually used to confirm a definitive diagnosis of cholangiocarcinoma. However, forceps biopsy and brush cytology provide positive results for malignancy in about only 50% of patients. Percutaneous and peroral cholangioscopy using fiber-optic techniques were therefore developed for direct visualization of the biliary tree, yielding additional information about endoscopic appearance and tumor extension, as well as a guided biopsy acquistion. Finally, endoscopic ultrasonography (EUS) complements endoscopic and percutaneous approaches and may provide a tissue diagnosis of tumors in the biliary region through fine- needle aspiration. In the future, new techniques allowing for early detection, including molecular markers, should be developed to improve the diagnostic sensitivity in this increasing tumor entity.

  3. Systemic approach to recreology

    Directory of Open Access Journals (Sweden)

    Tomáš Dohnal

    2010-03-01

    Full Text Available Man's life style undergoes in today's world significant changes within political systems, economy and social life. But changes concern also the content of leisure time and the way it is spent. European Union and, further to it, the Czech Republic have been creating legislative frame as well as economic and personal conditions in order to enable changes in the field of leisure time. A growing number of colleges and universities have lately been introducing curricula in the field of recreology (recreation and leisure time. Recreology (the Latin recreare + logos is conceived as a theoretical discipline exploring general recreation-related problems and, more precisely, problems related to the renewal of human energy. Our approach is based on the presumption that development and improvement is sought on one side and effort to prevent losses is strived for on the other. This work talks about systemic approach to recreology in frame of socio-cultural kin anthropology. Within its hierarchy, we conceive recreology as a subsystem of socio-cultural kin anthropology, the organization of which is, however, independent (it is a science field, curriculum and a subject of study.

  4. Engineering approaches to immunotherapy.

    Science.gov (United States)

    Swartz, Melody A; Hirosue, Sachiko; Hubbell, Jeffrey A

    2012-08-22

    As the science of immunology grows increasingly mechanistic, motivation for developing quantitative, design-based engineering approaches has also evolved, both for therapeutic interventions and for elucidating immunological pathways in human disease. This has seeded the nascent field of "immunoengineering," which seeks to apply engineering analyses and design approaches to problems in translational immunology. For example, cell engineers are creating ways to tailor and use immune cells as living therapeutics; protein engineers are devising new methods of rapid antibody discovery; biomaterials scientists are guiding vaccine delivery and immune-cell activation with novel constructs; and systems immunologists are deciphering the evolution and maintenance of T and B cell receptor repertoires, which could help guide vaccine design. The field is multidisciplinary and collaborative, with engineers and immunologists working together to better understand and treat disease. We discuss the scientific progress in this young, yet rapidly evolving research area, which has yielded numerous start-up companies that are betting on impact in clinical and commercial translation in the near future. PMID:22914624

  5. Advanced intelligence and mechanism approach

    Institute of Scientific and Technical Information of China (English)

    ZHONG Yixin

    2007-01-01

    Advanced intelligence will feature the intelligence research in next 50 years.An understanding of the concept of advanced intelligence as well as its importance will be provided first,and detailed analysis on an approach,the mechanism approach.suitable to the advanced intelligence research will then be flolowed.And the mutual relationship among mechanism approach,traditional approaches existed in artificial intelligence research,and the cognitive informatics will be discussed.It is interesting to discover that mechanism approach is a good one to the Advanced Intelligence research and a tmified form of the existed approaches to artificial intelligence.

  6. The Point Approach and the Phrase Approach to Vocabulary Learning

    Institute of Scientific and Technical Information of China (English)

    刘梦媛

    2013-01-01

      As is known to all, vocabulary acquisition plays an essential role in English learning. However, it was supposed very dif⁃ficult to many Chinese learners. For the reason that so many kinds of approaches exists in the real life, English learners are always do not know which one is suitable and more effective. To solve this problem, the paper will analyze two approaches (point approach and phrase approach) for you.

  7. Proteomics - new analytical approaches

    International Nuclear Information System (INIS)

    Full text: Recent developments in the sequencing of the human genome have indicated that the number of coding gene sequences may be as few as 30,000. It is clear, however, that the complexity of the human species is dependent on the much greater diversity of the corresponding protein complement. Estimates of the diversity (discrete protein species) of the human proteome range from 200,000 to 300,000 at the lower end to 2,000,000 to 3,000,000 at the high end. In addition, proteomics (the study of the protein complement to the genome) has been subdivided into two main approaches. Global proteomics refers to a high throughput examination of the full protein set present in a cell under a given environmental condition. Focused proteomics refers to a more detailed study of a restricted set of proteins that are related to a specified biochemical pathway or subcellular structure. While many of the advances in proteomics will be based on the sequencing of the human genome, de novo characterization of protein microheterogeneity (glycosylation, phosphorylation and sulfation as well as the incorporation of lipid components) will be required in disease studies. To characterize these modifications it is necessary to digest the protein mixture with an enzyme to produce the corresponding mixture of peptides. In a process analogous to sequencing of the genome, shot-gun sequencing of the proteome is based on the characterization of the key fragments produced by such a digest. Thus, a glycopeptide and hence a specific glycosylation motif will be identified by a unique mass and then a diagnostic MS/MS spectrum. Mass spectrometry will be the preferred detector in these applications because of the unparalleled information content provided by one or more dimensions of mass measurement. In addition, highly efficient separation processes are an absolute requirement for advanced proteomic studies. For example, a combination of the orthogonal approaches, HPLC and HPCE, can be very powerful

  8. Microscopic approach to polaritons

    DEFF Research Database (Denmark)

    Skettrup, Torben

    1981-01-01

    contrary to experimental experience. In order to remove this absurdity the semiclassical approach must be abandoned and the electromagnetic field quantized. A simple microscopic polariton model is then derived. From this the wave function for the interacting exciton-photon complex is obtained. It is...... of light of the crystal. The introduction of damping smears out the excitonic spectra. The wave function of the polariton, however, turns out to be very independent of damping up to large damping values. Finally, this simplified microscopic polariton model is compared with the exact solutions...... obtained for the macroscopic polariton model by Hopfield. It is seen that standing photon and exciton waves must be included in an exact microscopic polariton model. However, it is concluded that for practical purposes, only the propagating waves are of importance and the simple microscopic polariton wave...

  9. Modelling approaches for angiogenesis.

    Science.gov (United States)

    Taraboletti, G; Giavazzi, R

    2004-04-01

    The development of a functional vasculature within a tumour is a requisite for its growth and progression. This fact has led to the design of therapies directed toward the tumour vasculature, aiming either to prevent the formation of new vessels (anti-angiogenic) or to damage existing vessels (vascular targeting). The development of agents with different mechanisms of action requires powerful preclinical models for the analysis and optimization of these therapies. This review concerns 'classical' assays of angiogenesis in vitro and in vivo, recent approaches to target identification (analysis of gene and protein expression), and the study of morphological and functional changes in the vasculature in vivo (imaging techniques). It mainly describes assays designed for anti-angiogenic compounds, indicating, where possible, their application to the study of vascular-targeting agents. PMID:15120043

  10. Slurry pipeline design approach

    Energy Technology Data Exchange (ETDEWEB)

    Betinol, Roy; Navarro R, Luis [Brass Chile S.A., Santiago (Chile)

    2009-12-19

    Compared to other engineering technologies, the design of a commercial long distance Slurry Pipeline design is a relatively new engineering concept which gained more recognition in the mid 1960 's. Slurry pipeline was first introduced to reduce cost in transporting coal to power generating units. Since then this technology has caught-up worldwide to transport other minerals such as limestone, copper, zinc and iron. In South America, the use of pipeline is commonly practiced in the transport of Copper (Chile, Peru and Argentina), Iron (Chile and Brazil), Zinc (Peru) and Bauxite (Brazil). As more mining operations expand and new mine facilities are opened, the design of the long distance slurry pipeline will continuously present a commercially viable option. The intent of this paper is to present the design process and discuss any new techniques and approach used today to ensure a better, safer and economical slurry pipeline. (author)

  11. Management practice: phenomenological approach

    Directory of Open Access Journals (Sweden)

    Myriam Siqueira da Cunha

    2005-01-01

    Full Text Available This work has the aim of understanding the lived experiences by managers in relation to organizational changes in an enterprise in the food area, located in the State of Rio Grande do Sul, Brazil. The role of managers has been constantly evaluated and their capacity of continuous learning and also the ability of transforming the learning in good organizational results is reacquired every instant. In this work, my intention is to show, using an interpretative analysis, real and practical situations, from lived experiences. The methodological way followed was the hermeneutic phenomenological approach, trying to give a global and a contextual treatment to the theme. The results achieved offer subsides for a new look over the management practice and point out the importance of the study of what is lived, as an inspiration source for the strategic decisions in the enterprises.

  12. Integration a functional approach

    CERN Document Server

    Bichteler, Klaus

    1998-01-01

    This book covers Lebesgue integration and its generalizations from Daniell's point of view, modified by the use of seminorms. Integrating functions rather than measuring sets is posited as the main purpose of measure theory. From this point of view Lebesgue's integral can be had as a rather straightforward, even simplistic, extension of Riemann's integral; and its aims, definitions, and procedures can be motivated at an elementary level. The notion of measurability, for example, is suggested by Littlewood's observations rather than being conveyed authoritatively through definitions of (sigma)-algebras and good-cut-conditions, the latter of which are hard to justify and thus appear mysterious, even nettlesome, to the beginner. The approach taken provides the additional benefit of cutting the labor in half. The use of seminorms, ubiquitous in modern analysis, speeds things up even further. The book is intended for the reader who has some experience with proofs, a beginning graduate student for example. It might...

  13. Editorial: Approaching 125.

    Science.gov (United States)

    Goodman, Sherryl

    2012-02-01

    With this issue, beginning Volume 121, the editorial team shifts from the strong leadership of David Watson to a team under my direction. Approaching 125 years of publication, the Journal of Abnormal Psychology has earned its place as the preeminent outlet for research in psychopathology. With gratitude to the newly assembled team of associate editors (AEs), consulting editors, and ad hoc reviewers, I look forward to guiding the journal through this next term. Nine well-respected scholars have agreed to serve as AEs: Timothy Brown, Laurie Chassin, Jeff Epstein, Jutta Joormann, Pamela Keel, Kate Keenan, Scott Lilienfeld, Angus MacDonald, and Michael Young. The new team is dedicated to working tirelessly to maintain and enhance the journal's esteemed tradition of excellence. Given the well-established strengths of the journal, I will not suggest any fundamental changes. PMID:22329705

  14. The Tripod Approach

    DEFF Research Database (Denmark)

    Bang, Anne Louise

    2012-01-01

    The term ‘next to my skin’ is frequently used as a way to describe the close bonds between human beings and textiles. It is also widely accepted within the broad field of textile professionals that textile attributes related to emotional value – for example hand, look and drape – can be a make......-and-break decision for a company. However textile design research has shown that experience of emotional value is closely connected to fabric perception, and much literature suggests that textiles are experienced by a combination of sensory evaluation and memory associations. This paper introduces the Tripod...... Approach as a framework that can support designing the stimuli, which can lead to personal experiences of emotional value in relation to applied textiles. It can be used to access the relevant level of entry in the textile design process focusing on appropriate design parameters, and support designing the...

  15. Engineering students' sustainability approaches

    Science.gov (United States)

    Haase, S.

    2014-05-01

    Sustainability issues are increasingly important in engineering work all over the world. This article explores systematic differences in self-assessed competencies, interests, importance, engagement and practices of newly enrolled engineering students in Denmark in relation to environmental and non-environmental sustainability issues. The empirical base of the article is a nation-wide, web-based survey sent to all newly enrolled engineering students in Denmark commencing their education in the fall term 2010. The response rate was 46%. The survey focused on a variety of different aspects of what can be conceived as sustainability. By means of cluster analysis, three engineering student approaches to sustainability are identified and described. The article provides knowledge on the different prerequisites of engineering students in relation to the role of sustainability in engineering. This information is important input to educators trying to target new engineering students and contribute to the provision of engineers equipped to meet sustainability challenges.

  16. Bioengineering a conceptual approach

    CERN Document Server

    Pavlovic, Mirjana

    2015-01-01

    This book explores critical principles and new concepts in bioengineering, integrating the biological, physical and chemical laws and principles that provide a foundation for the field. Both biological and engineering perspectives are included, with key topics such as the physical-chemical properties of cells, tissues and organs; principles of molecules; composition and interplay in physiological scenarios; and the complex physiological functions of heart, neuronal cells, muscle cells and tissues. Chapters evaluate the emerging fields of nanotechnology, drug delivery concepts, biomaterials, and regenerative therapy. The leading individuals and events are introduced along with their critical research. Bioengineering: A Conceptual Approach is a valuable resource for professionals or researchers interested in understanding the central elements of bioengineering. Advanced-level students in biomedical engineering and computer science will also find this book valuable as a secondary textbook or reference.

  17. Proteomics approaches to fibrotic disorders

    OpenAIRE

    Gucek Marjan

    2012-01-01

    Abstract This review provides an introduction to mass spectrometry based proteomics and discusses several proteomics approaches that are relevant in understanding the pathophysiology of fibrotic disorders and the approaches that are frequently used in biomarker discovery.

  18. Endoscopic approach to achalasia

    Directory of Open Access Journals (Sweden)

    Michaela Müller

    2013-01-01

    Full Text Available Achalasia is a primary esophageal motor disorder. The etiology is still unknown and therefore all treatment options are strictly palliative with the intention to weaken the lower esophageal sphincter (LES. Current established endoscopic therapeutic options include pneumatic dilation (PD or botulinum toxin injection. Both treatment approaches have an excellent symptomatic short term effect, and lead to a reduction of LES pressure. However, the long term success of botulinum toxin (BT injection is poor with symptom recurrence in more than 50% of the patients after 12 mo and in nearly 100% of the patients after 24 mo, which commonly requires repeat injections. In contrast, after a single PD 40%-60% of the patients remain asymptomatic for ≥ 10 years. Repeated on demand PD might become necessary and long term remission can be achieved with this approach in up to 90% of these patients. The main positive predictors for a symptomatic response to PD are an age > 40 years, a LES-pressure reduction to 40 years, was nearly equivalent to surgery. A new promising technique might be peroral endoscopic myotomy, although long term results are needed and practicability as well as safety issues must be considered. Treatment with a temporary self expanding stent has been reported with favorable outcomes, but the data are all from one study group and must be confirmed by others before definite recommendations can be made. In addition to its use as a therapeutic tool, endoscopy also plays an important role in the diagnosis and surveillance of patients with achalasia.

  19. Neptune - closest approach

    Science.gov (United States)

    1989-01-01

    The Voyager spacecraft took this picture after closest approach to Neptune on Aug. 25 1989, using the clear filter of the wide-angle camera with an exposure time of 255 seconds. The view back towards Neptune at a phase angle of 135 degrees found the two known rings to be five to 10 times brighter than seen in backscattering during Voyager approach at much lower phase angle. This brightness increase implies a large percentage of microscopic particles within the rings. Although the dominant arc-like clump of the outer ring is not seen here, the inner ring appears brighter than the outer ring at the longitudes seen in this image. A faint sheet of material is also revealed that extends from the faint ring at a radius of 53,200 kilometers(33,000 miles). A new and even fainter ring was discovered in this image at about 41,000 kilometers (25,400 miles), seen running from the lower left corner to about one-third the way across the top of the frame. This ring is quite broad, about 2,500 kilometers (1,550 miles) in radial width. In contrast to the two previously discovered rings, this feature is quite diffuse and has no well defined radial boundaries. The Voyager imaging experiment has now detected ring material in all of the radial regions in which it has been detected by groundbased stellar occultation experiments. The Voyager spacecraft was 720,000 kilometers (446,400 miles) from Neptune at the time of this exposure. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications.

  20. SOME REFLECTIONS ON STRUCTURAL APPROACH

    Institute of Scientific and Technical Information of China (English)

    GuiQingyang

    1997-01-01

    The present paper is intended to expound the advantages and disadvantages of the trathtional Structural Approach in the Chinese context and discuss the necessity and feasibility of implementing the Communicative Approach and the Self--service Approach,both of which evaluate highly the position of subjective activity in learning and bring the obligation of professional development back to learners themselves,KEY WORD approach structural communicative self service critique adaptadopt

  1. The high risk location approach.

    NARCIS (Netherlands)

    2010-01-01

    The high risk location approach is one of the most traditional ways of improving road safety. This reactive approach tackles unsafe situations at locations with the most crashes. On average, this approach results in an 18% reduction in casualties at such locations. However, in the Netherlands this a

  2. An Institutional Approach to Technology

    OpenAIRE

    Werle, R

    1998-01-01

    Introduces Actor-Centered-Institutionalism (ACI), a variant of the institutionalist approach, to demonstrate the analytic power of conventional social theory in the field of Science, Technology and Society studies. History of the Social Construction of Technology approach; Illustration of the ACI approach; Examples from the process of organized international standardization in telecommunications and information technology.

  3. First multi-reactive dextran-based inisurf for atom transfer radical polymerization in miniemulsion.

    Science.gov (United States)

    Wu, Man; Forero Ramirez, Laura M; Rodriguez Lozano, Ana; Quémener, Damien; Babin, Jérôme; Durand, Alain; Marie, Emmanuelle; Six, Jean-Luc; Nouvel, Cécile

    2015-10-01

    A multi-reactive polysaccharide-based inisurf (acting both as initiator and stabilizer) has been designed for the first time from dextran with the aim of preparing dextran-covered nanoparticles with covalent linkage between core and coverage. This inisurf was used for polymerizing butyl acrylate in miniemulsion by AGET-ATRP. Both hydrophobic phenoxy groups and initiator groups (bromoisobutyryl ester) were introduced within hydrophilic dextran chain, conferring it amphiphilic and macroinitiator characters. Amphiphilic properties of dextran inisurfs have been evidenced as well as their ability to stabilize the direct miniemulsion of n-butyl acrylate. After optimization of polymerization conditions with model studies, assays were successfully realized with dextran-based inisurfs. Because of their amphiphilic character, inisurfs migrated at oil/water interface and initiated polymerization from bromoisobutyryl ester groups. Therefore graft copolymers were produced at oil/water interface, due to the multifunctional character of these inisurfs and constituted the particle inner core with covalent links to the dextran coverage. PMID:26076610

  4. New poly(dimethylsiloxane)/poly(perfluorooctylethyl acrylate) block copolymers: structure and order across multiple length scales in thin films

    KAUST Repository

    Martinelli, Elisa

    2011-01-01

    Three sets of a new class of low surface tension block copolymers were synthesized consisting of a poly(dimethylsiloxane) (PDMS) block and a poly(perfluorooctylethyl acrylate) (AF8) block. The polymers were prepared using a bromo-terminated PDMS macroinitiator, to which was attached an AF8 block grown using atom transfer radical polymerization (ATRP) in such a designed way that the molecular weight and composition of the two polymer blocks were regularly varied. The interplay of both the phase separated microstructure and the mesomorphic character of the fluorinated domains with their effect on surface structure was evaluated using a suite of analytical tools. Surfaces of spin-coated and thermally annealed films were assessed using a combination of X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) studies. Both atomic force microscopy (AFM) measurements and grazing incidence small angle X-ray scattering (GISAXS) studies were carried out to evaluate the microstructure of the thin films. Even in block copolymers in which the PDMS block was the majority component, a significant presence of the lower surface energy AF8 block was detected at the film surface. Moreover, the perfluorooctyl helices of the AF8 repeat units were highly oriented at the surface in an ordered, tilted smectic structure, which was compared with those of the bulk powder samples using wide-angle X-ray powder diffraction (WAXD) studies. © 2011 The Royal Society of Chemistry.

  5. Approach focused on people

    Directory of Open Access Journals (Sweden)

    Roa Ruben

    2010-11-01

    Full Text Available Family and community medicine assumes a new epistemological landmark that also provides the use of instruments and tools related to it. This care model permits carrying out a visit where all categories which the health-disease process is expressed are present. Family Medicine intends to combine both visions and, for such, it gifts elements to incorporate disease as an essential part of our patient's approach systematic being the main focus the approach by problems, which is nothing but that which concerns the individual, his family or the physician, or all of them, and at times there will be nuisances while at other times, there will be diseases, and mil in other instances, all of them will co-exist. It is known that the impact of a health problem on an individual affects not only himself, but also his surroundings. In turn, the environment around this individual can act as the origin or perpetuator of the crisis, or else serve to help in solving the conflict. Distinct tools serve the purpose of knowing the context in which health crisis is developed, such as: genogram, individual and family vital cycle. Every time two people communicate, the agreement or disagreement generate possible variables. In the physician-patient relationship, this is no exception. Values, beliefs, feelings, and information of each individual different and physicians not necessarily in agreement in several issues during a visit. The objective is the need to achieve a minimum of agreements so that this visit has therapeutic effectiveness, thus being if/rpm -taw to find a common territory. Relations in general involve power; care, feelings, trust and goals. The objective in this type of relationship must be obviously shared ly both and cannot be any other than that of achieving, the highest level of health to our patient. So, our specialty, considered of low complexity, becomes a highly cognitive complexity, special and there is no doubt that it is a lot easier to handle

  6. APPROACH TO ORGANIC ACIDEMIA

    Directory of Open Access Journals (Sweden)

    Gholamreza ZAMANI

    2012-03-01

    Full Text Available Organic acidemias, also known as organic acidurias, are a group of disorders characterized by increased excretion of organic acids in urine. They result primarily from deficiencies of specific enzymes in the breakdown pathways of amino acids or from enzyme deficiencies in beta oxidation of fatty acids or carbohydrate metabolism. Organic acids also are found in the urine of some patients with mitochondrial disease.Most organic acidemias become clinically apparent during the newborn period or early infancy. After an initial period of well-being, affected children develop a life-threatening episode of metabolic acidosis characterized by an increased anion gap. This presenting episode may be mistaken for sepsis, and if unrecognized, is associated with significant mortality.Children with an organic acidemia are susceptible to metabolic decompensation during episodes of increased catabolism, such as intercurrent illness, trauma, or surgery. Parents and clinicians must be well informed about the initial signs of decompensation and trained in applying an emergency regimen . Surgeons and anesthesiologists should be aware of potential complications and their prevention during anesthesia and surgery.Diagnosis has been facilitated through the use of gas chromatograph-mass spectrometry (GC-MS and tandem mass spectrometry .Prenatal diagnosis is available for most disorders by detection of diagnostic compounds in amniotic fluid; by analysis of enzyme activities in amniocytes or chorionic villi; by molecular analysis; or by a combination of the three . Diagnosis also may be made through newborn screening by tandem mass spectrometry .Laboratory findings are an essential part of the diagnostic approach to organic acidemias. In most organic acidemias, metabolism of glucose, ketone bodies, and ammonia is deranged primarily or secondarily, in addition to derangement of the acid-base balance. Hypoglycemia, lactic and/or ketoacidosis, and hyperammonemia of varying

  7. Approach to team skills training

    International Nuclear Information System (INIS)

    The US commercial nuclear power industry has recognized the importance of team skills in control room operation. The desire to combine training of team interaction skills, like communications, with technical knowledge of reactor operations requires a unique approach to training. An NRC-sponsored study identified a five-phase approach to team skills training designed to be consistent with the systems approach to training currently endorsed by the NRC Policy Statement on Training and Qualification. This paper describes an approach to team skills training with emphasis on the nuclear power plant control room crew. An approach to team skills training

  8. Text Steganographic Approaches: A Comparison

    Directory of Open Access Journals (Sweden)

    Monika Agarwal

    2013-02-01

    Full Text Available This paper presents three novel approaches of text steganography. The first approach uses the theme ofmissing letter puzzle where each character of message is hidden by missing one or more letters in a wordof cover. The average Jaro score was found to be 0.95 indicating closer similarity between cover andstego file. The second approach hides a message in a wordlist where ASCII value of embedded characterdetermines length and starting letter of a word. The third approach conceals a message, withoutdegrading cover, by using start and end letter of words of the cover. For enhancing the security of secretmessage, the message is scrambled using one-time pad scheme before being concealed and cipher text isthen concealed in cover. We also present an empirical comparison of the proposed approaches with someof the popular text steganographic approaches and show that our approaches outperform the existingapproaches.

  9. Light cone approach

    International Nuclear Information System (INIS)

    One of the most challenging problems in theoretical high energy physics is to compute the bound state structure of the proton and other hadrons from quantum chromodynamics (QCD), the field theory of quarks and gluons. The goal is not only to calculate the spectrum of hadrons masses from first principles, but also to derive the momentum and spin distributions of the quarks and gluons which control high energy hadron interactions. One approach to these difficult calculations is to simulate QCD on an artificial lattice. Recently, several new methods based on ''light-cone'' quantization have been proposed as alternatives to lattice theory for solving non-perturbative problems in QCD and other field theories. The basic idea is a generalization of Heisenberg's pioneer matrix formulation of quantum mechanics: if one could numerically diagonalize the matrix of the Hamiltonian representing the underlying QCD interaction, then the resulting eigenvalues would give the hadron spectrum, while the corresponding eigenstates would describe each hadron in terms of its quark and gluon degrees of freedom

  10. Combined approach for gynecomastia

    Science.gov (United States)

    El-Sabbagh, Ahmed Hassan

    2016-01-01

    Background: Gynecomastia is a deformity of male chest. Treatment of gynecomastia varied from direct surgical excision to other techniques (mainly liposuction) to a combination of both. Skin excision is done according to the grade. In this study, experience of using liposuction adjuvant to surgical excision was described. Patients and methods: Between September 2012 and April 2015, a total of 14 patients were treated with liposuction and surgical excision through a periareolar incision. Preoperative evaluation was done in all cases to exclude any underlying cause of gynecomastia. Results: All fourteen patients were treated bilaterally (28 breast tissues). Their ages ranged between 13 and 33 years. Two patients were classified as grade I, and four as grade IIa, IIb or III, respectively. The first 3 patients showed seroma. Partial superficial epidermolysis of areola occurred in 2 cases. Superficial infection of incision occurred in one case and was treated conservatively. Conclusion: All grades of gynecomastia were managed by the same approach. Skin excision was added to a patient that had severe skin excess with limited activity and bad skin complexion. No cases required another setting or asked for 2nd opinion. PMID:26955509

  11. Approaches to refractory epilepsy

    Directory of Open Access Journals (Sweden)

    Jerome Engel

    2014-01-01

    Full Text Available Epilepsy is one of the most common serious neurological conditions, and 30 to 40% of people with epilepsy have seizures that are not controlled by medication. Patients are considered to have refractory epilepsy if disabling seizures continue despite appropriate trials of two antiseizure drugs, either alone or in combination. At this point, patients should be referred to multidisciplinary epilepsy centers that perform specialized diagnostic testing to first determine whether they are, in fact, pharmacoresistant, and then, if so, offer alternative treatments. Apparent pharmacoresistance can result from a variety of situations, including noncompliance, seizures that are not epileptic, misdiagnosis of the seizure type or epilepsy syndrome, inappropriate use of medication, and lifestyle issues. For patients who are pharmacoresistant, surgical treatment offers the best opportunity for complete freedom from seizures. Surgically remediable epilepsy syndromes have been identified, but patients with more complicated epilepsy can also benefit from surgical treatment and require more specialized evaluation, including intracranial EEG monitoring. For patients who are not surgical candidates, or who are unwilling to consider surgery, a variety of other alternative treatments can be considered, including peripheral or central neurostimulation, ketogenic diet, and complementary and alternative approaches. When such alternative treatments are not appropriate or effective, quality of life can still be greatly improved by the psychological and social support services offered by multidisciplinary epilepsy centers. A major obstacle remains the fact that only a small proportion of patients with refractory epilepsy are referred for expert evaluation and treatment.

  12. APPROACHES TO PUBLIC INTEGRITY

    Directory of Open Access Journals (Sweden)

    Simona-Roxana ULMAN

    2015-08-01

    Full Text Available Both concepts, integrity and public integrity, are always asked qualities in the social and economic environment, but they are never well defined. In this context, finding precise definitions and offering an ample explanation of the concepts are desired and useful for both economic theoretical and practical levels and become the aim of the present paper. Without a good understanding of a concept, no one is capable to attain it. In this context, it is impossible to ask for a public sector of integrity if both public actors and the citizens do not know what it really means. Therefore, the public actors first have to understand what integrity really supposes, and, then, to be capable to respect its principles. Taking into consideration the effects of public integrity or, on its opposite, of the divergence from it, especially represented by the phenomenon of corruption, on the economy at the macro, but also, on the micro level, public integrity in itself becomes a real economic problem that is aimed to be extensively analyzed through our interdisciplinary approach.

  13. Aquatic environmental remediation approaches

    International Nuclear Information System (INIS)

    The 2011 Fukushima Daiichi Nuclear Plant's nuclear accident contaminated a significant portion of Fukushima Prefecture, and environmental remediation activities have been performed. To reduce the human exposure to the radiation induced by the nuclear contamination, one can reduce the radiation level in the environment, and/or eliminate radionuclide pathways to humans. This paper presents some case studies that are relevant to the Fukushima case. These examples include the Chernobyl nuclear accident's environmental and remediation assessments, U.S. Hanford environmental remediation activities, and the pesticide remediation assessment for the James River Estuary, Virginia, U.S.A. 1-D TODAM, 2-D FETRA and 3-D FLESCOT codes have been applied to the surface waters. TODAM code is currently being applied to the Ukedo and Takase rivers in Fukushima to predict cesium-137 migration in these rivers. A lesson learned from these experiences is that to achieve the effective clean-up, remediation decision makers must include knowledgeable scientists and competent engineers, so that environmental remediation activities are based on a scientifically-valid approach for a given contaminated location. Local participation to the remediation decision making is critically important. (author)

  14. Complex Macromolecular Architectures by Living Cationic Polymerization

    KAUST Repository

    Alghamdi, Reem D.

    2015-05-01

    Poly (vinyl ether)-based graft polymers have been synthesized by the combination of living cationic polymerization of vinyl ethers with other living or controlled/ living polymerization techniques (anionic and ATRP). The process involves the synthesis of well-defined homopolymers (PnBVE) and co/terpolymers [PnBVE-b-PCEVE-b-PSiDEGVE (ABC type) and PSiDEGVE-b-PnBVE-b-PSiDEGVE (CAC type)] by sequential living cationic polymerization of n-butyl vinyl ether (nBVE), 2-chloroethyl vinyl ether (CEVE) and tert-butyldimethylsilyl ethylene glycol vinyl ether (SiDEGVE), using mono-functional {[n-butoxyethyl acetate (nBEA)], [1-(2-chloroethoxy) ethyl acetate (CEEA)], [1-(2-(2-(t-butyldimethylsilyloxy)ethoxy) ethoxy) ethyl acetate (SiDEGEA)]} or di-functional [1,4-cyclohexanedimethanol di(1-ethyl acetate) (cHMDEA), (VEMOA)] initiators. The living cationic polymerizations of those monomers were conducted in hexane at -20 0C using Et3Al2Cl3 (catalyst) in the presence of 1 M AcOEt base.[1] The PCEVE segments of the synthesized block terpolymers were then used to react with living macroanions (PS-DPE-Li; poly styrene diphenyl ethylene lithium) to afford graft polymers. The quantitative desilylation of PSiDEGVE segments by n-Bu4N+F- in THF at 0 °C led to graft co- and terpolymers in which the polyalcohol is the outer block. These co-/terpolymers were subsequently subjected to “grafting-from” reactions by atom transfer radical polymerization (ATRP) of styrene to afford more complex macromolecular architectures. The base assisted living cationic polymerization of vinyl ethers were also used to synthesize well-defined α-hydroxyl polyvinylether (PnBVE-OH). The resulting polymers were then modified into an ATRP macro-initiator for the synthesis of well-defined block copolymers (PnBVE-b-PS). Bifunctional PnBVE with terminal malonate groups was also synthesized and used as a precursor for more complex architectures such as H-shaped block copolymer by “grafting-from” or

  15. Radiolab - three different approaches

    Directory of Open Access Journals (Sweden)

    Ola Stockfelt

    2012-04-01

    Full Text Available The three papers in this ‘suite’ have a special background and context. At the 2010 conference SoundActs in Aarhus the three panellists were each given the task to provide a paper with an analysis of the same sound object, thus exhibiting and contrasting different scholarly approaches to sound studies. The object was selected by Torben Sangild, who was familiar with the chosen context: the signature of the US radio programme and podcast Radiolab. The two other participants did not know the context and chose to analyse the sound object without further contextual investigation. This object was chosen for several reasons. First of all, it is brief (less than 17 seconds, which meant that it was possible to make a detailed analysis; at the same time, though, it is relatively complex, which means that it can accommodate three different analyses. It is a sound object with a global audience, taken from one of the most popular podcasts worldwide, accessible on the internet. Finally, it is a piece of functional sound design, rather than a work of art, which raises the question of context more clearly. The result is three rather different approaches: 1 a process analysis, observing analytical listening strategies towards the constructed object, 2 a vocal analysis, regarding the sound object as a polyphony of voices, and 3 a contextual analysis, framing the sound object as a radio signature. Ola Stockfelt analyses the sound object as something that is constructed via his own repeated listening process – as a scholarly-analytical analysis of the subjective act of creating meaning. He draws on presumptions and prejudices, demonstrating the impossibility of a purely structural listening. The analysis relates these hermeneutical reflections to formal musicological observations of harmony, timbre, space and rhythm in some detail. Ansa Lønstrup’s paper analyses the sound object as a polyphony of voices. Her analysis is inspired by two phenomenologists

  16. Morgagni hernia - laparoscopic approach

    Directory of Open Access Journals (Sweden)

    Şt.O. Georgescu

    2013-09-01

    Full Text Available INTRODUCTION: Morgagni hernia is due to a diaphragmatic defect, retrosternal congenital hernia being a rare form of hernie. The diagnosis is usually in childhood but there are cases that are found in adult or as a intraoperative surprise. The condition is asymptomatic or has nonspecific clinical manifestations or clinical dressing of often occlusive complications. The diagnosis is established by Rx thoracic imaging, barium enema or computed tomography (CT eso-gastro-duodenal passage. Treatment consists of reducing the hernia with or without dissection and resection of the hernia sac and diaphragmatic defect closure by suture the fascia endotoracica retrosternal and retrocostala or rectus abdominis sheath or plastic bag. CASE PRESENTATION: We present a case of a 49 years old woman admitted in our department for an insidious onset, several months ago, with postprandial upper abdominal pain, flatulence and nausea. CT scan revealed a mass of 95 / 130 / 80 mm, narrowly defined with homogeneous structure and negative densities (fat in the lower and middle mediastinum, outlining opacity described in cardiofrenic sinus radiography. The aspect was characteristic for a Morgagni hiatus hernia. Exploratory laparoscopy was performed using a 30º laparoscope inserted through a 10 mm supraombilical trocar; it revealed the parietal defect (Morgagni hernia and the herniation of greater omentum. Two additional 5 mm trocars are then inserted; the escaped great omentum was reintegrated and the parietal defect was laparoscopically sutured. To note, the peritoneal hernia sac was abandoned. Postoperative course was uneventful. A review of the literature data was also performed. CONCLUSION: Minimally invasive surgery is feasible, safe and tends to become “gold standard” therapeutic approach for the treatment of Morgagni hernia.

  17. The Activity-Based Approach

    OpenAIRE

    McNally, Michael G.; Rindt, Craig

    2008-01-01

    What is the activity-based approach (ABA) and how does it differ from the conventional trip-based model of travel behavior? From where has the activity approach evolved, what is its current status, and what are its potential applications in transportation forecasting and policy analysis. What have been the contributions of activity-based approaches to understanding travel behavior? The conventional trip-based model of travel demand forecasting (see Chapters 2 and 3) has always lacked...

  18. Approaches to variable pay systems

    OpenAIRE

    García-Hernández, Rosa

    2016-01-01

    The general goal of this thesis is to analyze, in some European countries, the connections of Variable Pay Systems with company behaviour, collective bargaining, wage determination and wage inequality. We introduce three different approaches to Variable Pay Systems. First, a company-industry approach in the case of Spain, using a qualitative methodology and analyzing competitiveness, productivity, unit labor cost and collective agreements. Second, a country-collective bargaining approach in t...

  19. New Approaches to Final Cooling

    CERN Document Server

    Neuffer, David

    2015-01-01

    A high-energy muon collider scenario requires a "final cooling" system that reduces transverse emittance by a factor of ~10 while allowing longitudinal emittance increase. The baseline approach has low-energy transverse cooling within high-field solenoids, with strong longitudinal heating. This approach and its recent simulation are discussed. Alternative approaches which more explicitly include emittance exchange are also presented. Round-to-flat beam transform, transverse slicing, and longitudinal bunch coalescence are possible components of the alternative approach. A more explicit understanding of solenoidal cooling beam dynamics is introduced.

  20. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... and E-poly antioxidant-infused technology during a hip replacement through the anterior supine intramuscular approach. “OR- ... Dr. Keith Berend perform an anterior approach total hip replacement with the patient on a regular OR ...

  1. ADOPT COMMUNICATIVE APPROACHES IN CET

    Institute of Scientific and Technical Information of China (English)

    LinSitan

    2004-01-01

    How to make CET tailored to the requirements of thesociety is a topic of great significance. This paper is meant toexplore the advantages of adopting communicative approaches inCET( College English Teaching ) by comparing communicativeapproaches with traditional ones and presenting our practice ofemploying communicative approaches as well as the result.

  2. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... during a hip replacement through the anterior supine intramuscular approach. “OR-Live,” the vision of improving health. ... the approach are operating through an internervous and intramuscular anatomic interval. It’s not necessary to detach any ...

  3. Approaches to Sequence Similarity Representation

    OpenAIRE

    Sokolov, Artem; Rachkovskij, Dmitri

    2006-01-01

    We discuss several approaches to similarity preserving coding of symbol sequences and possible connections of their distributed versions to metric embeddings. Interpreting sequence representation methods with embeddings can help develop an approach to their analysis and may lead to discovering useful properties.

  4. Extending Cosmology: The Metric Approach

    OpenAIRE

    Mendoza, Sergio

    2012-01-01

    Comment: 2012, Extending Cosmology: The Metric Approach, Open Questions in Cosmology; Review article for an Intech "Open questions in cosmology" book chapter (19 pages, 3 figures). Available from: http://www.intechopen.com/books/open-questions-in-cosmology/extending-cosmology-the-metric-approach

  5. The CAPM approach to materiality

    OpenAIRE

    Hadjieftychiou, Aristarchos

    1993-01-01

    Materiality is a pervasive accounting concept that has defied a precise quantitative definition. The Capital Asset Pricing Model (CAPM) approach to materiality provides a means for determining the limits that bound materiality. Also, the approach makes it possible to locate the point estimate within these limits based on certain assumptions.

  6. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... got coming out in “JBJS,” the early six-week recovery is dramatically different between a direct lateral abductor splitting approach and this anterior supine approach. Let me get this head on. My experience, these patients have full leg control in about 24 hours. Yeah. They can get out of bed and ...

  7. Mitochondrial biogenesis: pharmacological approaches.

    Science.gov (United States)

    Valero, Teresa

    2014-01-01

    Organelle biogenesis is concomitant to organelle inheritance during cell division. It is necessary that organelles double their size and divide to give rise to two identical daughter cells. Mitochondrial biogenesis occurs by growth and division of pre-existing organelles and is temporally coordinated with cell cycle events [1]. However, mitochondrial biogenesis is not only produced in association with cell division. It can be produced in response to an oxidative stimulus, to an increase in the energy requirements of the cells, to exercise training, to electrical stimulation, to hormones, during development, in certain mitochondrial diseases, etc. [2]. Mitochondrial biogenesis is therefore defined as the process via which cells increase their individual mitochondrial mass [3]. Recent discoveries have raised attention to mitochondrial biogenesis as a potential target to treat diseases which up to date do not have an efficient cure. Mitochondria, as the major ROS producer and the major antioxidant producer exert a crucial role within the cell mediating processes such as apoptosis, detoxification, Ca2+ buffering, etc. This pivotal role makes mitochondria a potential target to treat a great variety of diseases. Mitochondrial biogenesis can be pharmacologically manipulated. This issue tries to cover a number of approaches to treat several diseases through triggering mitochondrial biogenesis. It contains recent discoveries in this novel field, focusing on advanced mitochondrial therapies to chronic and degenerative diseases, mitochondrial diseases, lifespan extension, mitohormesis, intracellular signaling, new pharmacological targets and natural therapies. It contributes to the field by covering and gathering the scarcely reported pharmacological approaches in the novel and promising field of mitochondrial biogenesis. There are several diseases that have a mitochondrial origin such as chronic progressive external ophthalmoplegia (CPEO) and the Kearns- Sayre syndrome (KSS

  8. Surgical approaches to the elbow.

    Science.gov (United States)

    Cheung, Emilie V; Steinmann, Scott P

    2009-05-01

    Surgical exposures for complex injuries about the elbow are technically demanding because of the high density of neurologic, vascular, and ligamentous elements around the elbow. The posterior approaches (ie, olecranon osteotomy, triceps-reflecting, triceps-splitting, triceps-reflecting anconeus pedicle flap, paratricipital) include techniques used to navigate the area around the triceps tendon and anconeus muscle. These approaches may be extended to gain access to the entire joint. The ulnar nerve, the anterior and posterior capsules, and the coronoid process are addressed by means of a medial approach. Lateral approaches are useful in addressing pathology at the radial head, capitellum, coronoid process, and anterior and posterior capsules. These approaches may be combined to address complex pathology in the setting of fracture fixation, arthroplasty, and capsular release. PMID:19411644

  9. The biogenic approach to cognition.

    Science.gov (United States)

    Lyon, Pamela

    2006-03-01

    After half a century of cognitive revolution we remain far from agreement about what cognition is and what cognition does. It was once thought that these questions could wait until the data were in. Today there is a mountain of data, but no way of making sense of it. The time for tackling the fundamental issues has arrived. The biogenic approach to cognition is introduced not as a solution but as a means of approaching the issues. The traditional, and still predominant, methodological stance in cognitive inquiry is what I call the anthropogenic approach: assume human cognition as the paradigm and work 'down' to a more general explanatory concept. The biogenic approach, on the other hand, starts with the facts of biology as the basis for theorizing and works 'up' to the human case by asking psychological questions as if they were biological questions. Biogenic explanations of cognition are currently clustered around two main frameworks for understanding biology: self-organizing complex systems and autopoiesis. The paper describes the frameworks and infers from them ten empirical principles--the biogenic 'family traits'--that constitute constraints on biogenic theorizing. Because the anthropogenic approach to cognition is not constrained empirically to the same degree, I argue that the biogenic approach is superior for approaching a general theory of cognition as a natural phenomenon. PMID:16628463

  10. Vanpooling: the three major approaches

    Energy Technology Data Exchange (ETDEWEB)

    Sears, P.M.

    1979-08-01

    The manual provides technical assistance to existing or prospective vanpool sponsors. It is designed to help them promote vanpooling in its three major approaches: employer sponsored, third party sponsored, and driver owned and operated. The first chapter is an overview of vanpooling and a second chapter, on vanpool marketing, is addressed to ridesharing coordinators and others whose responsibilities include the promotion of vanpooling. Some fact sheets on the three approaches provide convenient summaries of the needs and opportunities of each approach and suggest solutions to practical problems likely to be encountered in starting new vanpool programs.

  11. A Biosemiotic Approach to Health

    DEFF Research Database (Denmark)

    Hoffmeyer, Jesper

    approaches are invaluable. The aim is to find a common platform that serves in treating human persons as undivided wholes. Since semiosis (viz. the meaningful interpretation of cues, signals, events or states) is vital to communication at both levels, the resulting sign-process is a viable choice as the......By replacing the traditional chemical approach to the understanding of body function by a sign-theoretic or semiotic approach, biosemiotics enters a no-man’s-land between biological and social domains of human life. The aim is not to subsume the social under the biological or vice versa; both...

  12. Approaches to Scandinavian Crime Fiction

    DEFF Research Database (Denmark)

    Agger, Gunhild

    2010-01-01

    The working paper discusses some of the major approaches to Scandinavian crime fiction in the light of the dominant features of crime culture, e.g. the broad exposure of crime fiction via different platforms and media. In this connection, the concept of mediatization is considered as well as the...... approach of genre typology and the concept of evil – seemingly disparate concepts and approaches, but all related to the complex processes in the borderlands between crime fiction and society. Using examples from Scandinavian crime fiction, I discuss whether the growing proximity to international genres......, ways of production and standards increasingly removes Scandinavian crime fiction from its original attractions or not....

  13. Lexical Approach to English Teaching

    Institute of Scientific and Technical Information of China (English)

    刘朝彦

    2001-01-01

    @@ 0. Introduction Advances in computer analysis of the English language have shown that lexical patterns are widespread in language use. Some researchers call them "lexical phrases" (Nattinger and DeCarrico,1992) or "lexical chunks" (Lewis, 1993); others use the term "multi-word chunks" or just "chunks"of language. Whatever the terms are, they are characteristic of language use and language acquisition and present advantages for language teaching and learning. The lexical approach to English teaching has received interest in recent years as an alternative to grammar-based approaches. The lexical approach concentrates on developing learners' skills in understanding and using words and word combinations.

  14. Treatment Approaches for Drug Addiction

    Science.gov (United States)

    ... for Drug Addiction DrugFacts: Treatment Approaches for Drug Addiction Email Facebook Twitter Revised July 2016 NOTE: This ... treatment options in your state. What is drug addiction? Drug addiction is a chronic disease characterized by ...

  15. Gloss Characterization: a Cyclic Approach

    OpenAIRE

    Viénot, Françoise

    2012-01-01

    In this paper, an approach to gloss characterization is described. We examine how information is transferred from the physical domain to the visual domain and how material properties are inferred from a cognitive interpretation, completing the characterization cycle.

  16. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... Taperloc Microplasty stem and E-poly antioxidant-infused technology during a hip replacement through the anterior supine ... renewed interest at this time due to several advantages that it brings. The approach that is performed ...

  17. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... an anterior approach total hip replacement with the patient on a regular OR table supine. My name ... less invasive without being small incision surgery. Obese patients can be easier due to less distribution of ...

  18. New approach to mass formulas

    International Nuclear Information System (INIS)

    The Regge approach to mass formulas is grounded. The main types of interrelations between meson masses are picked out and analysed. The spectrum of vector mesons with the fifth flavour is also evaluated

  19. Team Approach to Pain Relief

    Science.gov (United States)

    ... Navigation Bar Home Current Issue Past Issues The Team Approach to Pain Relief Past Issues / Fall 2007 ... Roberts is seen here with some of the team members, (left to right) Dr. Berger, Jacques Bolle, ...

  20. Abstract Cauchy problems three approaches

    CERN Document Server

    Melnikova, Irina V

    2001-01-01

    Although the theory of well-posed Cauchy problems is reasonably understood, ill-posed problems-involved in a numerous mathematical models in physics, engineering, and finance- can be approached in a variety of ways. Historically, there have been three major strategies for dealing with such problems: semigroup, abstract distribution, and regularization methods. Semigroup and distribution methods restore well-posedness, in a modern weak sense. Regularization methods provide approximate solutions to ill-posed problems. Although these approaches were extensively developed over the last decades by many researchers, nowhere could one find a comprehensive treatment of all three approaches.Abstract Cauchy Problems: Three Approaches provides an innovative, self-contained account of these methods and, furthermore, demonstrates and studies some of the profound connections between them. The authors discuss the application of different methods not only to the Cauchy problem that is not well-posed in the classical sense, b...

  1. System approach to chemistry course

    OpenAIRE

    Lorina E. Kruglova; Valentina G. Derendyaeva

    2010-01-01

    The article considers the raise of chemistry profile for engineers and constructors training, discloses the system approach to chemistry course and singles out the most important modules from the course of general chemistry for construction industry.

  2. The Dirac-Brueckner Approach

    OpenAIRE

    Brockmann, R.; Machleidt, R.

    1996-01-01

    In this review, we give a thorough introduction into the Dirac-Brueckner approach including the mathematical details of the formalism involved. Furthermore, we present results for nuclear matter, NN scattering in the nuclear medium, and finite nuclei.

  3. Nonlinear Approaches in Engineering Applications

    CERN Document Server

    Jazar, Reza

    2012-01-01

    Nonlinear Approaches in Engineering Applications focuses on nonlinear phenomena that are common in the engineering field. The nonlinear approaches described in this book provide a sound theoretical base and practical tools to design and analyze engineering systems with high efficiency and accuracy and with less energy and downtime. Presented here are nonlinear approaches in areas such as dynamic systems, optimal control and approaches in nonlinear dynamics and acoustics. Coverage encompasses a wide range of applications and fields including mathematical modeling and nonlinear behavior as applied to microresonators, nanotechnologies, nonlinear behavior in soil erosion,nonlinear population dynamics, and optimization in reducing vibration and noise as well as vibration in triple-walled carbon nanotubes. This book also: Provides a complete introduction to nonlinear behavior of systems and the advantages of nonlinearity as a tool for solving engineering problems Includes applications and examples drawn from the el...

  4. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... Dr. Eric Dewitt, from Belgium, who helped me learn this surgical approach. This is a previously described ... capsule. Okay. What do you think on the learning curve? 4 No, I think that’s good. I ...

  5. Anterior approach for knee arthrography

    International Nuclear Information System (INIS)

    Objective. To develop a new method of magnetic resonance arthrography (MRA) of the knee using an anterior approach analogous to the portals used for knee arthroscopy.Design. An anterior approach to the knee joint was devised mimicking anterior portals used for knee arthroscopy. Seven patients scheduled for routine knee MRA were placed in a decubitus position and under fluoroscopic guidance a needle was advanced from a position adjacent to the patellar tendon into the knee joint. After confirmation of the needle tip location, a dilute gadolinium solution was injected.Results and conclusion. All the arthrograms were technically successful. The anterior approach to knee MRA has greater technical ease than the traditional approach with little patient discomfort. (orig.)

  6. An Approach to Interface Synthesis

    DEFF Research Database (Denmark)

    Madsen, Jan; Hald, Bjarne

    1995-01-01

    Presents a novel interface synthesis approach based on a one-sided interface description. Whereas most other approaches consider interface synthesis as optimizing a channel to existing client/server modules, we consider the interface synthesis as part of the client/server module synthesis (which...... may contain the re-use of existing modules). The interface synthesis approach describes the basic transformations needed to transform the server interface description into an interface description on the client side of the communication medium. The synthesis approach is illustrated through a point......-to-point communication, but is applicable to synthesis of a multiple client/server environment. The interface description is based on a formalization of communication events....

  7. Approaches to Teaching Organizational Communication.

    Science.gov (United States)

    Applebaum, Ronald L.

    1998-01-01

    Discusses fundamental problems in selecting an approach to organizational communications; the purpose of an organizational communication course; the structure and content of organizational communication coursework; and teaching strategies used in the basic course in organizational communication. (RS)

  8. Theoretical Approaches to HERA Physics

    OpenAIRE

    Merino, C.

    2002-01-01

    A review is presented of the different theoretical models proposed to approach consistently the interplay between soft and hard physics, that can now be studied experimentally at HERA for the first time.

  9. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... intramuscular approach. “OR-Live,” the vision of improving health. Good evening and welcome to tonight’s webcast. We ... Biomet Orthopedics. “OR-Live,” the vision of improving health. 25

  10. Theoretical approaches to elections defining

    OpenAIRE

    Natalya V. Lebedeva

    2011-01-01

    Theoretical approaches to elections defining develop the nature, essence and content of elections, help to determine their place and a role as one of the major national law institutions in democratic system.

  11. Diakoptical Approach in Telecommunication Engineering

    OpenAIRE

    Yevsyeyeva, Oksana

    2010-01-01

    A diakoptical approach to tensor methods of telecommunications networks engineering, including design, traffic control and maintenance of QoS, is offered. The using of it increases scalability of tensor methods.

  12. Decomposition Approaches for Optimization Problems

    OpenAIRE

    Kinable, Joris

    2014-01-01

    This dissertation encompasses the development of decomposition approaches for a variety of both real-world and fundamental optimization problems. Many optimization problems comprise of multiple interconnected subproblems, often rendering them too large or too complicated to solve as a single integral problem. Decomposition approaches are required to deal with these problems efficiently. By decomposing a problem into multiple subproblems, efficient dedicated procedures can be employed to solve...

  13. The Database State Machine Approach

    OpenAIRE

    Pedone, Fernando; Guerraoui, Rachid; Schiper, Andre

    1999-01-01

    Database replication protocols have historically been built on top of distributed database systems, and have consequently been designed and implemented using distributed transactional mechanisms, such as atomic commitment. We present the Database State Machine approach, a new way to deal with database replication in a cluster of servers. This approach relies on a powerful atomic broadcast primitive to propagate transactions between database servers, and alleviates the need for atomic comm...

  14. Bounding approaches to system identification

    CERN Document Server

    Norton, John; Piet-Lahanier, Hélène; Walter, Éric

    1996-01-01

    In response to the growing interest in bounding error approaches, the editors of this volume offer the first collection of papers to describe advances in techniques and applications of bounding of the parameters, or state variables, of uncertain dynamical systems. Contributors explore the application of the bounding approach as an alternative to the probabilistic analysis of such systems, relating its importance to robust control-system design.

  15. Synergistic approach to patient dialysate

    OpenAIRE

    Dragotoiu, A; Checheriţă, AI; Ciocâlteu, A; Rizeanu, S

    2015-01-01

    The stress a patient is subjected to during dialysis treatment can be reduced by using a synergetic approach by the medical team. The integration into therapy of the positive psychical resources such as: active positive coping mechanisms, individual or family mental resilience, improvement of the image and self-esteem, better tolerance to frustration can represent an important part in the improvement of the patient’s quality of life, determination of a positive approach of the situations both...

  16. What is a Systems Approach?

    OpenAIRE

    Ryan, Alex J.

    2008-01-01

    What is a systems approach? The first step towards answering this question is an understanding of the history of the systems movement, which includes a survey of contemporary systems discourse. In particular, I examine how systems researchers differentiated their contribution from mechanistic science - but also from holistic doctrines; and identify the similarities and sharpest differences between complex systems and other systems approaches. Having set the scene, the second step involves dev...

  17. Universal Design, A Methodological Approach

    OpenAIRE

    Ielegems, Elke; Froyen, Hubert

    2014-01-01

    We gradually notice a shift from the partially superseded micro approach to accessibility (or barrier free design) to the new macro approach in Design for All or Universal Design. This UD concept gradually acquires global significance in the social, in the academic, and in the political field. Strong motivating factors for the new design paradigm are the challenge of an ageing population in Europe and in other parts of the world, and the crucial role of physical accessibility in securing Huma...

  18. Enactive metaphoric approaches to randomness

    OpenAIRE

    Díaz-Rojas, Daniela; Soto-Andrade, Jorge

    2015-01-01

    Our work aims at developing means to facilitating the access to stochastic thinking, especially for non-mathematically oriented learners. To this end, we draw on metaphoric and enactive approaches to the teaching and learning of randomness. More precisely, we report on a challenging didactical situation implemented in various classrooms, with students and prospective and practicing teachers, concerning problem posing and solving in the context of randomness that is approached through enactive...

  19. The information-processing approach.

    Science.gov (United States)

    van der Heijden, A H; Stebbins, S

    1990-01-01

    The information-processing (IP) approach to perception and cognition arose as a reaction to behaviourism. This reaction mainly concerned the nature of explanation in scientific psychology. The "standard" account of behaviour, phrased in strictly external terms, was replaced by a "realist" account, phrased in terms of internal entities and processes. An analysis of the theoretical language used in IP psychology shows an undisciplined state of affairs. A great number of languages is simultaneously in use; no level of analysis is unambiguously referred to; and basic concepts such as information and processing remain largely undefined. Nevertheless, over the past 25 years the IP approach has developed into a disciplined and sophisticated experimental science. A look at actual practice hints at the basic reason for its success. The approach is not so much concerned with absolute or intrinsic properties of the human information processor, but with what can be called its relative or differential properties. A further analysis of this feature of the IP approach in terms of the formal language of a logical system makes explicit the basis of its success. The IP approach can be regarded as developing an empirical difference calculus on an unspecified class of objects, phrased in terms of a simulated "theory-neutral" observation language, and with operators that are structurally analogous to logical operators. This reinterpretation of what the IP approach is about brings a number of advantages. It strengthens its position as an independent science, clarifies its relation with other approaches within psychology and other sciences within the cognitive science group, and makes it independent of philosophical subtleties. PMID:2281128

  20. Toward predicate approaches to modality

    CERN Document Server

    Stern, Johannes

    2016-01-01

    In this volume, the author investigates and argues for, a particular answer to the question: What is the right way to logically analyze modalities from natural language within formal languages? The answer is: by formalizing modal expressions in terms of predicates. But, as in the case of truth, the most intuitive modal principles lead to paradox once the modal notions are conceived as predicates. The book discusses the philosophical interpretation of these modal paradoxes and argues that any satisfactory approach to modality will have to face the paradoxes independently of the grammatical category of the modal notion. By systematizing modal principles with respect to their joint consistency and inconsistency, Stern provides an overview of the options and limitations of the predicate approach to modality that may serve as a useful starting point for future work on predicate approaches to modality. Stern also develops a general strategy for constructing philosophically attractive theories of modal notions conce...

  1. Understanding SARS with Wolfram Approach

    Institute of Scientific and Technical Information of China (English)

    Da-WeiLI; Yu-XiPAN; YunDUAN; Zhen-DeHUNG; Ming-QingXU; LinHE

    2004-01-01

    Stepping acquired immunodeficiency syndrome (AIDS), severe acute respiratory syndrome (SARS) as another type of disease has been threatening mankind since late last year. Many scientists worldwide are making great efforts to study the etiology of this disease with different approaches. 13 species of SARS virus have been sequenced. However, most people still largely rely on the traditional methods with some disadvantages. In this work, we used Wolfram approach to study the relationship among SARS viruses and between SARS viruses and other types of viruses, the effect of variations on the whole genome and the advantages in the analysis of SARS based on this novel approach. As a result, the similarities between SARS viruses and other coronaviruses are not really higher than those between SARS viruses and non-coronaviruses.

  2. Solid mechanics a variational approach

    CERN Document Server

    Dym, Clive L

    2013-01-01

    Solid Mechanics: A Variational Approach, Augmented Edition presents a lucid and thoroughly developed approach to solid mechanics for students engaged in the study of elastic structures not seen in other texts currently on the market. This work offers a clear and carefully prepared exposition of variational techniques as they are applied to solid mechanics. Unlike other books in this field, Dym and Shames treat all the necessary theory needed for the study of solid mechanics and include extensive applications. Of particular note is the variational approach used in developing consistent structural theories and in obtaining exact and approximate solutions for many problems.  Based on both semester and year-long courses taught to undergraduate seniors and graduate students, this text is geared for programs in aeronautical, civil, and mechanical engineering, and in engineering science. The authors’ objective is two-fold: first, to introduce the student to the theory of structures (one- and two-dimensional) as ...

  3. Thermodynamic approach to biomass gasification

    International Nuclear Information System (INIS)

    The document presents an approach of biomass transformation in presence of steam, hydrogen or oxygen. Calculation results based on thermodynamic equilibrium are discussed. The objective of gasification techniques is to increase the gas content in CO and H2. The maximum content in these gases is obtained when thermodynamic equilibrium is approached. Any optimisation action of a process. will, thus, tend to approach thermodynamic equilibrium conditions. On the other hand, such calculations can be used to determine the conditions which lead to an increase in the production of CO and H2. An objective is also to determine transformation enthalpies that are an important input for process calculations. Various existing processes are assessed, and associated thermodynamic limitations are evidenced. (author)

  4. A general approach to bosonization

    Indian Academy of Sciences (India)

    Girish S Setulur; V Meera

    2007-10-01

    We summarize recent developments in the field of higher dimensional bosonization made by Setlur and collaborators and propose a general formula for the field operator in terms of currents and densities in one dimension using a new ingredient known as a `singular complex number'. Using this formalism, we compute the Green function of the homogeneous electron gas in one spatial dimension with short-range interaction leading to the Luttinger liquid and also with long-range interactions that lead to a Wigner crystal whose momentum distribution computed recently exhibits essential singularities. We generalize the formalism to finite temperature by combining with the author's hydrodynamic approach. The one-particle Green function of this system with essential singularities cannot be easily computed using the traditional approach to bosonization which involves the introduction of momentum cutoffs, hence the more general approach of the present formalism is proposed as a suitable alternative.

  5. City evacuations an interdisciplinary approach

    CERN Document Server

    Binner, Jane; Branicki, Layla; Galla, Tobias; Jones, Nick; King, James; Kolokitha, Magdalini; Smyrnakis, Michalis

    2015-01-01

    Evacuating a city is a complex problem that involves issues of governance, preparedness education, warning, information sharing, population dynamics, resilience and recovery. As natural and anthropogenic threats to cities grow, it is an increasingly pressing problem for policy makers and practitioners.   The book is the result of a unique interdisciplinary collaboration between researchers in the physical and social sciences to consider how an interdisciplinary approach can help plan for large scale evacuations.  It draws on perspectives from physics, mathematics, organisation theory, economics, sociology and education.  Importantly it goes beyond disciplinary boundaries and considers how interdisciplinary methods are necessary to approach a complex problem involving human actors and increasingly complex communications and transportation infrastructures.   Using real world case studies and modelling the book considers new approaches to evacuation dynamics.  It addresses questions of complexity, not only ...

  6. The narrative approach in Bioethics

    Directory of Open Access Journals (Sweden)

    Mario Picozzi

    2015-04-01

    Full Text Available Nowadays, the narrative approach in Bioethics is more and more considered and used. In our paper we would like to explain why – when we need to take a decision – it is essential and crucial that the patient tells his own history; we also indicate the main consequences that this approach has with reference to the choices at the bed of the patient. Selected Papers of the Congress “Narrative Based Medicine and Communication in Clinical Practice” · Cagliari, Italy · April 14th, 2014 Guest Editors: Massimiliano Zonza, Vassilios Fanos, Gian Paolo Donzelli

  7. A practical approach to TQI.

    Science.gov (United States)

    Perras, S T; Mattern, M

    1994-04-01

    Total quality improvement (TQI) is a refreshing new approach to leadership that can be applied to a dialysis setting. The team approach to prospective data analysis is used for problem solution and reevaluation. Adapting theory to daily practical application can be successfully done using time, energy, and full senior management commitment. Staff education and involvement are essential to successful program implementation. Evaluation tools are easily adapted to analyze common dialysis problems. The initial time invested in education and data collection can be great but results in a streamlined process. PMID:8080313

  8. Probabilistic approach to EMP assessment

    International Nuclear Information System (INIS)

    The development of nuclear EMP hardness requirements must account for uncertainties in the environment, in interaction and coupling, and in the susceptibility of subsystems and components. Typical uncertainties of the last two kinds are briefly summarized, and an assessment methodology is outlined, based on a probabilistic approach that encompasses the basic concepts of reliability. It is suggested that statements of survivability be made compatible with system reliability. Validation of the approach taken for simple antenna/circuit systems is performed with experiments and calculations that involve a Transient Electromagnetic Range, numerical antenna modeling, separate device failure data, and a failure analysis computer program

  9. Real analysis a constructive approach

    CERN Document Server

    Bridger, Mark

    2012-01-01

    A unique approach to analysis that lets you apply mathematics across a range of subjects This innovative text sets forth a thoroughly rigorous modern account of the theoretical underpinnings of calculus: continuity, differentiability, and convergence. Using a constructive approach, every proof of every result is direct and ultimately computationally verifiable. In particular, existence is never established by showing that the assumption of non-existence leads to a contradiction. The ultimate consequence of this method is that it makes sense-not just to math majors but also to students from a

  10. Elementary calculus an infinitesimal approach

    CERN Document Server

    Keisler, H Jerome

    2012-01-01

    This first-year calculus book is centered around the use of infinitesimals, an approach largely neglected until recently for reasons of mathematical rigor. It exposes students to the intuition that originally led to the calculus, simplifying their grasp of the central concepts of derivatives and integrals. The author also teaches the traditional approach, giving students the benefits of both methods.Chapters 1 through 4 employ infinitesimals to quickly develop the basic concepts of derivatives, continuity, and integrals. Chapter 5 introduces the traditional limit concept, using approximation p

  11. Analytic approaches to kaon physics

    Science.gov (United States)

    de Rafael, Eduardo

    2003-05-01

    Most of the: analytic approaches which are used at present to understand the low energy hadronic interactions in Particle Physics, get their inspiration from QCD in the limit of a large number of colors N c. I first, illustrate this with tire example of the left-right correlation function which is an excellent theoretical laboratory. Next, 1 present the list, of observabtes which have been computed using a large- N c QCD approach. Finally, I discuss ill some detail examples which are relevant to lattice QCD, in the sense that we can make comparisons.

  12. Systems biology approach to bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Romy; Wu, Cindy H.; Hazen, Terry C.

    2012-06-01

    Bioremediation has historically been approached as a ‘black box’ in terms of our fundamental understanding. Thus it succeeds and fails, seldom without a complete understanding of why. Systems biology is an integrated research approach to study complex biological systems, by investigating interactions and networks at the molecular, cellular, community, and ecosystem level. The knowledge of these interactions within individual components is fundamental to understanding the dynamics of the ecosystem under investigation. Finally, understanding and modeling functional microbial community structure and stress responses in environments at all levels have tremendous implications for our fundamental understanding of hydrobiogeochemical processes and the potential for making bioremediation breakthroughs and illuminating the ‘black box’.

  13. Multidisciplinary Approaches in Evolutionary Linguistics

    Science.gov (United States)

    Gong, Tao; Shuai, Lan; Wu, Yicheng

    2013-01-01

    Studying language evolution has become resurgent in modern scientific research. In this revival field, approaches from a number of disciplines other than linguistics, including (paleo)anthropology and archaeology, animal behaviors, genetics, neuroscience, computer simulation, and psychological experimentation, have been adopted, and a wide scope…

  14. Thoracoscopy: a collaborative surgical approach.

    Science.gov (United States)

    Brand, A F

    1995-07-01

    Perioperative nurses, surgeons, anesthesiologists, certified registered nurse anesthetists, and pharmacists are meeting the challenge of decreasing thoracic surgical patients' length of hospital stay with thoracoscopy. This innovative alternative to traditional thoracotomy procedures has been achieved through an attentive team approach using the fundamental perioperative skills of assessment, positioning, safety, and sharing of knowledge. PMID:7647761

  15. Coordinate Geometric Approach to Spherometer

    CERN Document Server

    Khan, Sameen Ahmed

    2013-01-01

    The spherometer used for measuring radius of curvature of spherical surfaces is explicitly based on a geometric relation unique to circles and spheres. We present an alternate approach using coordinate geometry, which reproduces the well-known result for the spherometer and also leads to a scheme to study aspherical surfaces. We shall also briefly describe some of the modified spherometers.

  16. Oncoplastic Approaches to Breast Conservation

    Directory of Open Access Journals (Sweden)

    Dennis R. Holmes

    2011-01-01

    Full Text Available When a woman is diagnosed with breast cancer many aspects of her physical, emotional, and sexual wholeness are threatened. The quickly expanding field of oncoplastic breast surgery aims to enhance the physician commitment to restore the patient's image and self-assurance. By combining a multidisciplinary approach to diagnosis and treatment with oncoplastic surgery, successful results in the eyes of the patient and physician are significantly more likely to occur. As a way to aid oncoplastic teams in determining which approach is most suitable for their patient's tumor size, tumor location, body habitus, and desired cosmetic outcome we present a review of several oncoplastic surgical approaches. For resections located anywhere in the breast, the radial ellipse segmentectomy incision and circumareolar approach for segmental resection are discussed. For resections in the upper or central breast, crescent mastopexy, the batwing incision, the hemibatwing incision, donut mastopexy, B-flap resection, and the central quadrantectomy are reviewed. For lesions of the lower breast, the triangle incision, inframammary incision, and reduction mastopexy are discussed. Surgeons who are interested in adding oncoplastic breast conserving therapies to their skill sets are encouraged to implement these surgical techniques where applicable and to seek out breast fellowships or enhanced training when appropriate.

  17. THE ECONOMIC APPROACH TO EDUCATION

    OpenAIRE

    Marinela GEAMANU

    2009-01-01

    Economics education is circumscribe a multiplicative feedback through expansion, diversification, intensive interaction between the economy and education, as being in an economic perspective on education, along with sociological, psychological, technological, religious, family, public, etc. pespective, in other words, an application of economic theories, paradigms and approaches to economic education act, act deeply human, spiritual nature. In practice perspective, the economy has education a...

  18. Budgeting Approaches in Community Colleges

    Science.gov (United States)

    Palmer, James C.

    2014-01-01

    Several budgeting approaches have been initiated as alternatives to the traditional, incremental process. These include formula budgeting; zero-base budgeting; planning, programming, and budgeting systems; and responsibility center budgeting. Each is premised on assumptions about how organizations might best make resource allocation decisions.…

  19. International Approaches to Clinical Costing

    DEFF Research Database (Denmark)

    Chapman, Christopher; Kern, Anja; Laguecir, Aziza;

    This report has been commissioned by both HFMA and Monitor and the work has been led by Imperial College Business School’s Health Management Group. The report compares current approaches to costing, primarily across Europe. The findings reveal wide-ranging practices and uses for costing data, and...

  20. Probabilistic approach to reptation theory

    Czech Academy of Sciences Publication Activity Database

    Kharlamov, Alexander; Švrčinová, Petra; Filip, Petr

    Cardiff : Cardiff University, 2009. s. 1-1. [Annual European Rheology Conference /5./. 15.04.2009-17.04.2009, Cardiff] R&D Projects: GA ČR GA103/09/2066 Institutional research plan: CEZ:AV0Z20600510 Keywords : tube model * reptation theory * probabilistic approach Subject RIV: BK - Fluid Dynamics

  1. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... have these vessels. And in our experience thus far with this approach, Roger, I would completely agree. ... had to, because it doesn’t retract very far, it’s been my experience. That’s a good view. ...

  2. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... this view, I mean this is the traditional Smith Meet Jeu De view of the acetabulum,. I ... re using only part of what’s called the “Smith-Peterson approach.” The true Smith- Peterson, you would ...

  3. Approaching Bose-Einstein Condensation

    Science.gov (United States)

    Ferrari, Loris

    2011-01-01

    Bose-Einstein condensation (BEC) is discussed at the level of an advanced course of statistical thermodynamics, clarifying some formal and physical aspects that are usually not covered by the standard pedagogical literature. The non-conventional approach adopted starts by showing that the continuum limit, in certain cases, cancels out the crucial…

  4. A Psychoanalytic Approach to Fieldwork

    Science.gov (United States)

    Ramvi, Ellen

    2012-01-01

    This article focuses on what both psychoanalysis and anthropology have in common: the emphasis on the researcher's own experience. An ethnographic fieldwork will be used to illustrate how a psychoanalytical approach unfolds the material when studying conditions for learning from experience among teachers in two Norwegian junior high schools, and…

  5. Planning approaches for rurban areas

    DEFF Research Database (Denmark)

    Busck, Anne Gravsholt; Hidding, Marjan; Kristensen, Søren Bech Pilgaard;

    2009-01-01

    encroachment, and how resilient green landscapes are ensured. The results reveal significant differences in approaches, reflecting variations in the public involvement in rurban areas development, the role of different administrative levels and the use of zonation. Variation in the use of zonation encapsulates...

  6. Oncoplastic Approaches to Breast Conservation

    International Nuclear Information System (INIS)

    When a woman is diagnosed with breast cancer many aspects of her physical, emotional, and sexual wholeness are threatened. The quickly expanding field of oncoplastic breast surgery aims to enhance the physician commitment to restore the patient's image and self-assurance. By combining a multidisciplinary approach to diagnosis and treatment with oncoplastic surgery, successful results in the eyes of the patient and physician are significantly more likely to occur. As a way to aid oncoplastic teams in determining which approach is most suitable for their patient's tumor size, tumor location, body habitus, and desired cosmetic outcome we present a review of several oncoplastic surgical approaches. For resections located anywhere in the breast, the radial ellipse segmentectomy incision and circumareolar approach for segmental resection are discussed. For resections in the upper or central breast, crescent mastopexy, the batwing incision, the hemi batwing incision, donut mastopexy, B-flap resection, and the central quadrantectomy are reviewed. For lesions of the lower breast, the triangle incision, infra mammary incision, and reduction mastopexy are discussed. Surgeons who are interested in adding oncoplastic breast conserving therapies to their skill sets are encouraged to implement these surgical techniques where applicable and to seek out breast fellowships or enhanced training when appropriate

  7. Teacher Training: A Personal Approach.

    Science.gov (United States)

    Henson, Kenneth T.

    Indiana State University has developed an experimental program to develop a personal approach to teacher training. The ultimate intention of the program is to produce educators who are personally committed to the development of the young people often collectively labeled "students." Devices used in the program include the use of student names,…

  8. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... is Dr. Roger Emerson from Plano, Texas, and I will be moderating this webcast. I will ask Dr. Berend questions, and we can ... webcast, you have an interest in this procedure. I have used this approach myself since 2005, and ...

  9. Animal timing: a synthetic approach.

    Science.gov (United States)

    de Carvalho, Marilia Pinheiro; Machado, Armando; Vasconcelos, Marco

    2016-07-01

    Inspired by Spence's seminal work on transposition, we propose a synthetic approach to understanding the temporal control of operant behavior. The approach takes as primitives the temporal generalization gradients obtained in prototypical concurrent and retrospective timing tasks and then combines them to synthetize more complex temporal performances. The approach is instantiated by the learning-to-time (LeT) model. The article is divided into three parts. In the first part, we review the basic findings concerning the generalization gradients observed in fixed-interval schedules, the peak procedure, and the temporal generalization procedure and then describe how LeT explains them. In the second part, we use LeT to derive by gradient combination the typical performances observed in mixed fixed-interval schedules, the free-operant psychophysical procedure, the temporal bisection task, and the double temporal bisection task. We also show how the model plays the role of a useful null hypothesis to examine whether temporal control in the bisection task is relative or absolute. In the third part, we identify a set of issues that must be solved to advance our understanding of temporal control, including the shape of the generalization gradients outside the range of trained stimulus durations, the nature of temporal memories, the influence of context on temporal learning, whether temporal control can be inhibitory, and whether temporal control is also relational. These issues attest to the heuristic value of a Spencean approach to temporal control. PMID:27000781

  10. Adolescent Obesity: Rethinking Traditional Approaches.

    Science.gov (United States)

    Morrill, Correen M.; And Others

    1991-01-01

    Describes traditional approaches to working with obese students (weight loss programs, nutrition programs, self-esteem groups). Suggests system-based alternative. Suggests providing in-service workshops for staff; developing team to work with large students; providing individual counseling; assisting students in locating peer support groups; and…

  11. Cleft Palate; A Multidiscipline Approach.

    Science.gov (United States)

    Stark, Richard B., Ed.

    Nineteen articles present a multidisciplinary approach to the management of facial clefts. The following subjects are discussed: the history of cleft lip and cleft palate surgery; cogenital defects; classification; the operation of a cleft palate clinic; physical examination of newborns with cleft lip and/or palate; nursing care; anesthesia;…

  12. Bilingual Approaches to Language Learning

    Institute of Scientific and Technical Information of China (English)

    MaryMcgroarty; NorthernArizonaUniversity

    2003-01-01

    “Billingual Approaches to Language Learning” describes the various bilingual models found at different levels(elementary,secondary,post-secondary,and adult education),identifying key instructional features and emphasizing the drive for quality instruction.The paper makes reference to consideration of the political contexts as well as pedagogical factors affecting the choices and outcomes related to bilingual instruction.

  13. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... box. That’s right. Or in this case the computer. Yeah. Exactly. We’ll make some comments later ... of the ilium. Yeah. We’re using only part of what’s called the “Smith-Peterson approach.” The ...

  14. Guitar Class: A Multifaceted Approach.

    Science.gov (United States)

    Bartel, Lee R.

    1990-01-01

    Suggests that the bias linking guitars to popular culture has needlessly limited approaches to teaching guitar. Examines how each of five current programs develops different music skills. Advocates a comprehensive, multifaceted program capable of emphasizing student skills in melody, harmony, perception, creativity, and performance over six years…

  15. Approaching Environmental Issues in Architecture

    DEFF Research Database (Denmark)

    Petersen, Mads Dines; Knudstrup, Mary-Ann

    2013-01-01

    The research presented here takes its point of departure in the design process with a specific focus on how it is approached when designing energy efficient architecture. This is done through a case-study of a design process in a Danish architectural office. This study shows the importance of...

  16. Teaching Persuasion: A Positive Approach.

    Science.gov (United States)

    Fenton, Mary C.

    The synthesis of four instructional models for argumentative writing--the Toulmin, Hiduke, Winder, and Crebbe-Debate approaches--with basic discourse theory produces a practical and positive method of teaching college students to write effective persuasive essays. A battery of questions based on a modified communication triangle--subject…

  17. Nuclear regulation - the Canadian approach

    International Nuclear Information System (INIS)

    Although the Atomic Energy Control Board was established 35 years ago the basic philosophy of nuclear regulation in Canada and the underlying principles of the regulatory process remain essentially unchanged. This paper outlines the Canadian approach to nuclear regulation and explains in practical terms how the principles of regulation are applied. (author)

  18. Orthodontic–periodontics interdisciplinary approach

    OpenAIRE

    Vinod, K.; Reddy, Y. Giridhar; Reddy, Vinay P.; Nandan, Hemant; Sharma, Meenakshi

    2012-01-01

    In this present era, when a significant number of patients seeking orthodontic treatment are adults, importance of multidisciplinary treatment approach cannot be overemphasized. Higher susceptibility of plaque accumulation in patients undergoing orthodontic treatment makes involvement of periodontist almost unavoidable. Also, orthodontic treatment frequently results in undesirable periodontal changes which require immediate attention. More recently, orthodontics has been used as an adjunct to...

  19. A Freudian Approach to Education.

    Science.gov (United States)

    Gartner, Sandra L.

    This document offers the point of view that Bruno Bettelheim's writings, based on Sigmund Freud's approach to education, suggest the most practical applications for achieving positive results within the classroom. The overall result of a student being taught all through school by the Freudian method would be an extremely positive one. Such a…

  20. Algorithmic approach to diagram techniques

    International Nuclear Information System (INIS)

    An algorithmic approach to diagram techniques of elementary particles is proposed. The definition and axiomatics of the theory of algorithms are presented, followed by the list of instructions of an algorithm formalizing the construction of graphs and the assignment of mathematical objects to them. (T.A.)

  1. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... the anterior supine intramuscular approach. “OR-Live,” the vision of improving health. Good evening and welcome to ... should know that this is done under direct vision. Yeah. You are seeing everything you’re doing. ...

  2. A Complexity Approach for Steganalysis

    CERN Document Server

    Bahi, Jacques M; Heam, Pierre-Cyrille

    2011-01-01

    In this proposal for the Journ\\`ees Codes et St\\'eganographie 2012, we define a new rigorous approach for steganalysis based on the complexity theory. It is similar to the definitions of security that can be found for hash functions, PRNG, and so on. We propose here a notion of \\emph{secure hiding} and we give a first secure hiding scheme.

  3. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... is at the bottom of your screen where it says, “Ask a question.” Since you have tuned ... this approach myself since 2005, and currently use it for most of my primary and even some ...

  4. Novel Approaches to Surfactant Administration

    OpenAIRE

    Samir Gupta; Donn, Steven M.

    2012-01-01

    Surfactant replacement therapy has been the mainstay of treatment for preterm infants with respiratory distress syndrome for more than twenty years. For the most part, surfactant is administered intratracheally, followed by mechanical ventilation. In recent years, the growing interest in noninvasive ventilation has led to novel approaches of administration. This paper will review these techniques and the associated clinical evidence.

  5. New Approach for Image Fusion Based on Curvelet Approach

    Directory of Open Access Journals (Sweden)

    Gehad Mohamed Taher

    2014-08-01

    Full Text Available Most of the image fusion work has been limited to monochrome images. Algorithms which utilize human colour perception are attracting the image fusion community with great interest. It is mainly due to the reason that the use of colour greatly expands the amount of information to be conveyed in an image. Since, the human visual system is very much sensitive to colours; research was undertaken in mapping three individual monochrome multispectral images to the respective channels of an RGB image to produce a false colour fused image. Producing a fused colour output image which maintains the original chromaticity of the input visual image is highly tricky. The focus of this paper is developing a new approach to fuse a color image (visual image and a corresponding grayscale one (Infrared image – IR using the curvelet approach using different fusion rules in new fields. The fused image obtained by the proposed approach maintain the high resolution of the colored image (visual image, incorporate any hidden object given by the IR sensor as an example, or complements the two input images and keep the natural color of the visual image.

  6. Bayesian approach to rough set

    CERN Document Server

    Marwala, Tshilidzi

    2007-01-01

    This paper proposes an approach to training rough set models using Bayesian framework trained using Markov Chain Monte Carlo (MCMC) method. The prior probabilities are constructed from the prior knowledge that good rough set models have fewer rules. Markov Chain Monte Carlo sampling is conducted through sampling in the rough set granule space and Metropolis algorithm is used as an acceptance criteria. The proposed method is tested to estimate the risk of HIV given demographic data. The results obtained shows that the proposed approach is able to achieve an average accuracy of 58% with the accuracy varying up to 66%. In addition the Bayesian rough set give the probabilities of the estimated HIV status as well as the linguistic rules describing how the demographic parameters drive the risk of HIV.

  7. A Psychoanalytic Approach to Fieldwork

    Directory of Open Access Journals (Sweden)

    Ellen Ramvi

    2012-12-01

    Full Text Available This article focuses on what both psychoanalysis and anthropology have in common: the emphasis on the researcher’s own experience. An ethnographic fieldwork will be used to illustrate how a psychoanalytical approach unfolds the material when studying conditions for learning from experience among teachers in two Norwegian junior high schools, and also the strong methodological implications of this approach. The researcher’s struggle to remain open is elaborated. Here “openness” is regarded as something more than a principle for research practice. It is a way to relate both to oneself and the other, to emotions as well as actions, to the inner as well as the external world.

  8. Temperature Dependent Nuclear Matter Approach

    International Nuclear Information System (INIS)

    Full text: The nuclear matter approach provides an effective interaction in the presence of a sea of nucleons. Especially it accounts for the Pauli principle which forbids scattering processes into the occupied states of the nucleonic see. It is well suited to describe the bulk properties of nuclei as well as optical potentials beyond 40 MeV incident energy. Difficulties in the description of nucleon-nucleus reactions beyond 70 MeV may indicate the importance of excited doorway states for reaction processes and therefore the optical potentials. In this contribution we consider the g-matrix approach for excited nuclear matter. The g-matrix is evaluated via the Bethe-Goldstone equation with an exact Pauli operator accounting for excitations with arbitrary occupation distributions. The features of the g-matrix with regard to changes in excitation are discussed. (author)

  9. An approach to risk assessment

    DEFF Research Database (Denmark)

    Simonsen, L.; Lund, S. P.; Hass, Ulla

    1998-01-01

    results indicate that numerous persons are exposed in the working as well as in the general environment to several chemicals, for which almost no data on the effect on subtle neurophysiological functions are available. Development of an approach to risk assessment dealing with this problem is a major...... challenge in the nineties. Different approaches to risk assessment are discussed, the quality of the databases available for hazard assessment are evaluated, and the needs for further research are identified. (C) 1996 Intox Press, Inc.......A strategy for delineating risk factors from use of neurotoxic chemicals was applied to the Danish working environment. An analysis using this strategy disclosed the need for internationally adopted criteria for neurotoxicity, and consequently a working group was established by the Nordic Council...

  10. Ecosystemic approaches to land degradation

    International Nuclear Information System (INIS)

    Land degradation is recognized as the main outcome of desertification. However available procedures for its assessment are still unsatisfactory because are often too costly for surveying large areas and rely on specific components of the degradation process without being able to integrate them in a unique process. One of the objectives of De Survey project is designing and implementing operational procedures for desertification surveillance, including land degradation. A strategic report was compiled and reproduced here for selecting the most appropriate approaches to the project conditions. The report focuses on using attributes of ecosystem maturity as a natural way to integrate the different drivers of land degradation in simple indices. The review surveys different families of attributes concerned with water and energy fluxes through the ecosystem, its capacity to sustain biomass and net primary productivity, and its capacity to structure the space. Finally, some conclusions are presented about the choice criteria of the different approaches in the framne of operational applications. (Author) 20 refs.

  11. BRST Approach to Hamiltonian Systems

    CERN Document Server

    Aringazin, A K; Kudusov, A S

    1998-01-01

    BRST formulation of cohomological Hamiltonian mechanics is presented. In the path integral approach, we use the BRST gauge fixing procedure for the partition function with trivial underlying Lagrangian to fix symplectic diffeomorphism invariance. Resulting Lagrangian is BRST and anti-BRST exact and the Liouvillian of classical mechanics is reproduced in the ghost-free sector. The theory can be thought of as a topological phase of Hamiltonian mechanics and is considered as one-dimensional cohomological field theory with the target space a symplectic manifold. Twisted (anti-)BRST symmetry is related to global N=2 supersymmetry, which is identified with an exterior algebra. Landau-Ginzburg formulation of the associated $d=1$, N=2 model is presented and Slavnov identity is analyzed. We study deformations and perturbations of the theory. Physical states of the theory and correlation functions of the BRST invariant observables are studied. This approach provides a powerful tool to investigate the properties of Hami...

  12. Nanorobotics current approaches and techniques

    CERN Document Server

    Ferreira, Antoine

    2013-01-01

    Nanorobot devices now perform a wide variety of tasks at the nanoscale in a wide variety of fields including but not limited to fields such as manufacturing, medicine, supply chain, biology, and outer space. Nanorobotics: Current Approaches and Techniques is a comprehensive overview of this interdisciplinary field with a wide ranging discussion that includes nano-manipulation and industrial nanorobotics, nanorobotics in biology and medicine, nanorobotic sensing, navigation and swarm behavior, and protein and DNA-based nanorobotics. Also included is the latest on topics such as bio-nano-actuators and propulsion and navigation of nanorobotic systems using magnetic fields. Nanorobotics: Current Approaches and Techniques is an ideal book for scientists, researchers, and engineers actively involved in applied and robotic research and development.

  13. Novel approaches in herbal cosmetics.

    Science.gov (United States)

    Chanchal, Deep; Swarnlata, Saraf

    2008-06-01

    Nutracosmetics are an emerging class of health and beauty aid products that combine the benefits of nutracosmetical ingredients with the elegance, skin feel, and delivery systems of cosmetics. Herbs and spices have been used in maintaining and enhancing human beauty because herbs have many beneficial properties, such as sunscreen, antiaging, moisturizing, antioxidant, anticellulite, and antimicrobial effects. As compared with synthetic cosmetic products, herbal products are mild, biodegradable, and have low toxicity profile. To enhance these properties, research is being done in the development of newer approaches, which could improve both the aesthetic appeal and performance of a cosmetic product. In this respect, the approaches studied and discussed include liposomes, phytosomes, transferosomes, nanoemulsions, nanoparticles, microemulsions, nanocrystals, and cubosomes. PMID:18482010

  14. Observability during planetary approach navigation

    Science.gov (United States)

    Bishop, Robert H.; Burkhart, P. Daniel; Thurman, Sam W.

    1993-01-01

    The objective of the research is to develop an analytic technique to predict the relative navigation capability of different Earth-based radio navigation measurements. In particular, the problem is to determine the relative ability of geocentric range and Doppler measurements to detect the effects of the target planet gravitational attraction on the spacecraft during the planetary approach and near-encounter mission phases. A complete solution to the two-dimensional problem has been developed. Relatively simple analytic formulas are obtained for range and Doppler measurements which describe the observability content of the measurement data along the approach trajectories. An observability measure is defined which is based on the observability matrix for nonlinear systems. The results show good agreement between the analytic observability analysis and the computational batch processing method.

  15. Communicative Approach and Educational Success

    Institute of Scientific and Technical Information of China (English)

    Wang Jianfang

    2001-01-01

    The quality and benefit of college English teaching is, to some extent, decided by what methodological approach it employs. The current teaching syllabus adopts the communicative approach, which is well established as the dominant theoretical model in college English teaching. This paper tries to discuss these characteristics and explain why the model, procedure and links of college English teaching in the classroom are so vital to improve the language and communicative abilities of students. The teaching methods cannot and should not be fixed. It is restricted by the English levels and learning strategies of students,and by the academic quality and teaching ideas of teachers. A good teacher is such and flexibly to help his students attain the goal that syllabus demands.

  16. Ecosystemic approaches to land degradation

    Energy Technology Data Exchange (ETDEWEB)

    Puigdefabregas, J.; Barrio, G. del; Hill, J.

    2009-07-01

    Land degradation is recognized as the main outcome of desertification. However available procedures for its assessment are still unsatisfactory because are often too costly for surveying large areas and rely on specific components of the degradation process without being able to integrate them in a unique process. One of the objectives of De Survey project is designing and implementing operational procedures for desertification surveillance, including land degradation. A strategic report was compiled and reproduced here for selecting the most appropriate approaches to the project conditions. The report focuses on using attributes of ecosystem maturity as a natural way to integrate the different drivers of land degradation in simple indices. The review surveys different families of attributes concerned with water and energy fluxes through the ecosystem, its capacity to sustain biomass and net primary productivity, and its capacity to structure the space. Finally, some conclusions are presented about the choice criteria of the different approaches in the framne of operational applications. (Author) 20 refs.

  17. Control theory: A practical approach

    International Nuclear Information System (INIS)

    Stability and frequency response enhancements can be made to custom manufactured and off-the-shelf power supplies. Combined power converter and magnet loads that result in poor transient response and marginal loop stability due to inadequate phase margin can be corrected with a systematic approach utilizing lead compensation techniques. Using a Venable Systems 350 Frequency Response Analyzer two actual case studies are documented demonstrating a practical approach to stabilizing and enhancing a power supply's performance. A description of the system and conventions are followed by a description of two power supplies with specific deficiencies. The first case study involves a power supply without a dominant pole output capacitor. The next case study involves a power supply driving a highly damped resonant load. The paper is concluded by a discussion of measurements pitfalls

  18. Different approaches to surgical pupilloplasty

    OpenAIRE

    Pina, S; Pedrosa, C; Azevedo, A.; Ramalho, M; Pêgo, P; Feijóo, B; Prieto, I

    2012-01-01

    Purpose: To describe three different minimal invasive surgical approaches for correction of traumatic and congenital pupil abnormalities. Setting/Venue: Ophthalmology Department, Prof Dr. Fernando Fonseca Hospital EPE. Amadora, Lisboa, Portugal Methods: We describe three clinical cases with pupil abnormalities from different ethiology, all submitted to pupiloplasty in order to improve visual and aesthetic outcome. First patient presented a traumatic aphakia and ectopic pupil in his righ...

  19. Energetic approach for ductile tearing

    International Nuclear Information System (INIS)

    This study focuses on ductile crack initiation and propagation. It aims to propose an approach for the engineer allowing the prediction of the evolution of cracks in large scale components, from parameters determined on laboratory specimens. A crack initiation criterion, defining a Ji tenacity related to crack tip blunting proposed in the literature is validated in the study. This criterion is shown to be transferable from laboratory specimens to structures. The literature review shows that an approach based on the dissipated energy in the fracture process during propagation offers an economical and simple solution to simulate large crack growth. A numerical method is proposed to estimate this fracture energy. The existence of an energy parameter Gfr is shown, by simulating the propagation by the simultaneous release of several elements and by the use of the Rice integral with an original integration path. This parameter represents the needed energy for a unit crack extension and appears to be intrinsic to the material. A global energy statement allows to relate this parameter to a variation of the plastic part of J integral. It offers a second numerical method to simulate the propagation just from stationary numerical calculations, as well as the elaboration of a simplified method. This approach, using two parameters Ji and Gfr, intrinsic to the material and experimentally measurable on specimens, is validated on many tests such as crack pipes subjected to four points bending and cracked rings in compression. For example, this approach allows to model up to 90 mm ductile tearing in a pipe with a circumferential through-wall crack in ferritic steel, or to anticipate the evolution of a semi-elliptical crack in an aged austenitic ferritic steel plate subjected to bending. (author)

  20. APPROACHES ON THE COMPETITIVE INTELLIGENCE

    OpenAIRE

    Ioan PETRIŞOR; Natalia Ana STRĂIN (SILAŞ)

    2013-01-01

    Within this study, we approached the concept of "competitive intelligence" (CI), which we consider a key element for the success of a business, especially in the current period, characterized by numerous economic and financial turbulence. According to Society of Competitive Intelligence (SCIP), competitive intelligence is defined as a method of ethical and moral collection, analysis and dissemination of information regarding the competitive environment, opportunities, vulnerabilities, and int...

  1. Energy mastery: context, stakes, approaches

    International Nuclear Information System (INIS)

    Any energy use has both an environmental and an economical impact. The environmental stakes linked with the energy use impose to adapt the policies and practices towards a more rational use of energy sources and towards the improvement of energy systems efficiency. This document deals with the national and international context, the economical, energetic and environmental stakes and with the political and technical approaches of energy mastery. It is illustrated with the mastery of power demand. (J.S.)

  2. New Approaches In Digestive Surgery

    OpenAIRE

    Martínez Ferré, Bernat

    2014-01-01

    Póster Oesophageal surgery has been associated with greater incisional dehiscence than surgery in other portions of the alimentary tract. Several factors may contribute to the high complication rate, including lack of serosa and omentum, the segmental nature of blood supply, the constant motion of swallowing and respiration and the tension at the surgical site. Regenerative medicine approaches facilitate the use of biological constructs to replace or regenerate normal tissue function. T...

  3. Interdisciplinary approach in translation didactics

    OpenAIRE

    Lee Jahnke, Hannelore

    2011-01-01

    The question why interdisciplinary research and approach in translation didactics has become essential and of interest to translation studies will be outlined prior to highlighting three to our thinking major disciplines of interest. Those are: 1. cognitive and affective sciences with a specific interest of evaluation methods and the implicit and explicit knowledge; 2. cognitive sciences and neurosciences leading to a more proficient structuring of a course; 3. research in comp...

  4. Oncoplastic Approaches to Breast Conservation

    OpenAIRE

    Holmes, Dennis R.; Wesley Schooler; Robina Smith

    2011-01-01

    When a woman is diagnosed with breast cancer many aspects of her physical, emotional, and sexual wholeness are threatened. The quickly expanding field of oncoplastic breast surgery aims to enhance the physician commitment to restore the patient's image and self-assurance. By combining a multidisciplinary approach to diagnosis and treatment with oncoplastic surgery, successful results in the eyes of the patient and physician are significantly more likely to occur. As a way to aid oncoplastic t...

  5. The Holographic Approach to Cosmology

    CERN Document Server

    Banks, T

    2004-01-01

    We review the successes and challenges of the holographic approach to cosmology. The model predicts an exactly scale invariant fluctuation spectrum with long and short distance cut-offs. It can account for the observed fluctuations in the CMB and might explain the low power at large scales. We outline various cosmological histories compatible with holographic initial conditions. This paper is based on talks given by the authors at Cosmo 04 in Toronto, and the 2004 Tamura Symposium in Austin

  6. Humanoid Introspection: A Practical Approach

    OpenAIRE

    Ignazio Infantino; Giovanni Pilato; Riccardo Rizzo; Filippo Vella

    2013-01-01

    We describe an approach to robot introspection based on self observation and communication. Self observation is what the robot should do in order to build, represent and understand its internal state. It is necessary to translate the state representation in order to build a suitable input to an ontology that supplies the meaning of the internal state. The ontology supports the linguistic level that is used to communicate information about the robot state to the human user.

  7. Money: A Market Microstructure Approach

    OpenAIRE

    Krueger, Malte

    2008-01-01

    The current discussion about the future of the financial system draws heavily on a set of theories known as the ‘New Monetary Economics’. The New Monetary Economics predicts that deregulation and financial innovation will lead to a moneyless world. This paper uses a market microstructure approach to show that a common medium of exchange that serves as unit of account will remain a necessary instrument to reduce transaction costs. This finding is supported by empirical evidence from foreign...

  8. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... Let’s save that image. Go to the other side. Now I’ll tell you one other thing about this approach, Roger, is that the stem size and stem position is right on every time, because if you look at this image, I feel like that’s a really good size there. Perfect. I like the way it’s ...

  9. New Approach to Resonance Crossing

    OpenAIRE

    Franchetti, G.; Zimmermann, F.

    2012-01-01

    Time varying nonlinear oscillatory systems produce phenomena of resonance crossing and trapping of particles in resonance islands. Traditionally such processes have been analyzed in terms of adiabatic conditions. Considering, as an example, a simplified 1-dimensional (1-D) model describing the “electron cloud pinch” during a bunch passage in a particle accelerator, here we present an approach to resonance trapping which does not require any adiabatic condition. Instead we introduce the concep...

  10. The enter-educate approach.

    Science.gov (United States)

    Piotrow, P T; Coleman, P L

    1992-03-01

    This article describes how the Population Communication Services (PCS) has seized on the "enter-educate" approach, the blending of popular entertainment with social messages, to change reproductive health behavior. The enter-educate approach spreads its message through songs, soap operas, variety shows, and other types of popular entertainment mediums. Because they entertain, enter-educate projects can capture the attention of an audience -- such as young people -- who would otherwise scorn social messages. And the use of population mediums makes it possible to reach a variety of audiences. Funded by USAID, PCS began its first enter-educate project in response to the increasing number of teenage pregnancies in Latin America. PCS developed 2 songs and videos, which featured popular teenage singers to serve as role models, to urge abstinence. The songs became instant hits. Since then, PCS has mounted more then 80 major projects in some 40 countries. Highlights of programs range from a successful multi-media family planning campaign in Turkey to humorous television ads in Brazil promoting vasectomy. Recently, PCS initiated projects to teach AIDS awareness. At the core of the enter-educate approach is the social learning theory which holds that much behavior is learned through the observation of role-models. Health professionals work alongside entertainers to produce works that have audience appeal and factual social messages. The enter-educate approach works because it is popular, pervasive, personal, persuasive, and profitable. PCS has found that enter-educate programs pay for themselves through cost sharing and cost recovery. PMID:12284960

  11. IMBALANCED DATA LEARNING APPROACHES REVIEW

    Directory of Open Access Journals (Sweden)

    Mohamed Bekkar

    2013-07-01

    Full Text Available The present work deals with a well-known problem in machine learning, that classes have generally skewed prior probabilities distribution. This situation of imbalanced data is a handicap when trying to identify the minority classes , usually more interesting one In real world applications. This paper is an attempt to list the different approachs proposed in scientific research to deal with the imbalanced data learning, as well a comparison between various applications cases performed on this subject.

  12. HEALTHCARE MARKETING - A RELATIONAL APPROACH

    OpenAIRE

    CAZACU Lavinia; OPRESCU, Alina Elena

    2015-01-01

    This paper aims to identify the unique characteristics of healthcare services, the challenges faced in the implementation of marketing principles into the healthcare services sector and also the behavior tendencies of the healthcare consumer. Taking into account the differences between healthcare services and other services and the importance of the doctor-patient relationship, a new marketing approach seems to be a solution for all problems and a response for all unanswered questions. A revi...

  13. Study of Chunks Input Approach

    Institute of Scientific and Technical Information of China (English)

    马静

    2003-01-01

    This paper is to describe and investigate Chunks (Lexical Phrases ) Input Approach in vocabulary learning strategies by means of achievement tests,questionnaire surveys and interviews. The study is to reveal how different learners combine different vocabulary learning strategies in their learning process. With the data collected, the author of this paper discusses and summarizes learners' individual differences in selecting vocabulary learning strategies with the hope of giving new insights into English teaching and learning.

  14. Interactive Approaches to Rural Development

    OpenAIRE

    Teilmann, Kasper Aalling

    2012-01-01

    The dissertation ‘Interactive Approaches to Rural Development’ gives new theoretical and empirical knowledge in the collaboration on development of rural areas and landscapes. From a perspective about the development and the challenges faced, the study analyses which functions that are demanded by the rural areas. Furthermore, the study makes an analysis of the collaboration in an EU financed rural development association; the Local Action Group (LAG). The overall objective ...

  15. Transcriptional approaches to riboswitch studies

    OpenAIRE

    Mironov, Alexander; Epshtein, Vitaly; Nudler, Evgeny

    2009-01-01

    Natural RNA sensors of small molecules (a.k.a. riboswitches) regulate numerous metabolic genes. In bacteria, these RNA elements control transcription termination and translation initiation by changing the folding pathway of nascent RNA upon direct binding of a metabolite. To identify and study riboswitches we used in vitro reconstituted solid-phase transcription elongation/termination system. This approach allows for direct monitoring ligand binding and riboswitch functioning, establishing th...

  16. Combined Approach for Image Segmentation

    OpenAIRE

    2014-01-01

    Many image segmentation techniques have been developed over the past two decades for segmenting the images, which help for object recognition, occlusion boundary estimation within motion or stereo systems, image compression, image editing. In this, there is a combined approach for segmenting the image. By using histogram equalization to the input image, from which it gives contrast enhancement output image .After that by applying median filtering,which will remove noise from contrast output i...

  17. Molecular approaches for bacterial azoreductases

    OpenAIRE

    Montira Leelakriangsak

    2013-01-01

    Azo dyes are the dominant types of synthetic dyes, widely used in textiles, foods, leather, printing, tattooing, cosmetics, and pharmaceutical industries. Many microorganisms are able to decolorize azo dyes, and there is increasing interest in biological waste treatment methods. Bacterial azoreductases can cleave azo linkages (-N=N-) in azo dyes, forming aromatic amines. This review mainly focuses on employing molecular approaches, including gene manipulation and recombinant strains, to study...

  18. Multidisciplinary approaches to solar hydrogen

    OpenAIRE

    Bren, Kara L.

    2015-01-01

    This review summarizes three different approaches to engineering systems for the solar-driven evolution of hydrogen fuel from water: molecular, nanomaterials and biomolecular. Molecular systems have the advantage of being highly amenable to modification and detailed study and have provided great insight into photophysics, electron transfer and catalytic mechanism. However, they tend to display poor stability. Systems based on nanomaterials are more robust but also are more difficult to synthe...

  19. A conceptual approach to immunodeficiency.

    Science.gov (United States)

    Bardana, E J

    1981-09-01

    Immunodeficiency represents a congenital or acquired aberration of immune function which is commonly associated with autoimmunity and neoplasia as a potential triad of biologic sequelae. Irrespective of the initial focal point in the triad, the natural evolution of the condition is frequently associated with the other two. This conceptualization should increase the clinician's ability in a more understanding approach to the evaluation and care of immunocompromised patients. PMID:7026918

  20. Approaches to folyl polyglutamate analysis

    OpenAIRE

    Yang, Yingying

    2013-01-01

    The literature review presented the effects of the polyglutamate chain on the biological and nutritional properties of folates and the main methods used for folate assays, with a special emphasis on the approaches to studying intact polyglutamates. A brief introduction regarding safety aspects of folate fortification was also given. The aim of this study was to develop a UPLC-FLR/PDA method for simultaneous determination of polyglutamyl folate vitamers. Chromatographic conditions were opt...

  1. Optimization approach to entanglement distillation

    OpenAIRE

    Opatrny, T.; Kurizki, G.

    1998-01-01

    We put forward a method for optimized distillation of partly entangled pairs of qubits into a smaller number of more entangled pairs by recurrent local unitary operations and projections. Optimized distillation is achieved by minimization of a cost function with up to 30 real parameters, which is chosen to be sensitive to the fidelity and the projection probability at each step. We show that in many cases this approach can significantly improve the distillation efficiency in comparison to the...

  2. Thermodynamic Approach to Generalized Continua

    CERN Document Server

    Ván, P; Papenfuss, C

    2013-01-01

    Governing equations of dissipative generalized solid mechanics are derived by thermodynamic methods in the Piola-Kirchhoff framework using the Liu procedure. The isotropic small strain case is investigated in more detail. The connection to the Ginzburg-Landau type evolution, dual internal variables, and a thermodynamic generalization of the standard linear solid model of rheology is demonstrated. Specific examples are chosen to emphasize experimental confirmations and predictions beyond less general approaches.

  3. BLM's ecosystem approach to management

    OpenAIRE

    Dombeck, Mike

    1995-01-01

    Ecosystem management is about maintaining the health, diversity, and productivity of the land, i.e., clean water, abundant native perennial grasses, sustainable fish populations, healthy watersheds. We will use the ecosystem approach to streamline administrative processes and improve fiscal and environmental accountability. It involves coordinated planning at the local level, forming partnerships, and using good information to manage the land Education is key. The principles of ecosystem mana...

  4. [Psychosomatic approach for chronic migraine].

    Science.gov (United States)

    Hashizume, Masahiro

    2011-11-01

    From psychosomatic view point, the psychological or social stresses and depressive or anxiety disorders are very important factors in the course and the maintenance for migraine patients. These factors are very complex, and often lead the migraine becoming chronic. In the psychosomatic approach, not only the physical assessment for chronic migraine but also the assessments for stress and mental states are done. As the psychosomatic therapies for chronic migraine, autogenic training, biofeedback therapy and cognitive therapy are effective. PMID:22277516

  5. OECD Approach to Interdisciplinary Studies

    OpenAIRE

    M. R. Dehshiri

    2010-01-01

    The present article endeavours to examine, through a descriptive and analytical methodology, the approach taken by the Organization for Economic Cooperation and Development (OECD), regarding interdisciplinary studies in the field of Higher Education. The research explains the programmes and policies of this organization in the area of Higher Education and discusses the process of the evolution of interdisciplinary towards transdisciplinarity in the surveys and researches conducted by the orga...

  6. The Entrepreneurial Approach in Marketing

    OpenAIRE

    Florin Foltean

    2007-01-01

    The marketing - entrepreneurship interface at corporate level has generated many debates and studies in the last two decades, both in marketing and entrepreneurship fields. Certain elements of marketing orientation and approach may be used in the development of entrepreneurial processes, while entrepreneurial orientation and behavior enhance the marketing performance of a company which operates in a dynamic environment. This paper presents the concept of entrepreneurial marketing, a proposed ...

  7. Combinatorial approaches to gene recognition.

    Science.gov (United States)

    Roytberg, M A; Astakhova, T V; Gelfand, M S

    1997-01-01

    Recognition of genes via exon assembly approaches leads naturally to the use of dynamic programming. We consider the general graph-theoretical formulation of the exon assembly problem and analyze in detail some specific variants: multicriterial optimization in the case of non-linear gene-scoring functions; context-dependent schemes for scoring exons and related procedures for exon filtering; and highly specific recognition of arbitrary gene segments, oligonucleotide probes and polymerase chain reaction (PCR) primers. PMID:9440930

  8. New Approaches to Percutaneous Gastrostomy

    OpenAIRE

    O'Dowd, Mariana; Given, M. Fredrick; Lee, Michael J.

    2004-01-01

    Novel approaches to percutaneous gastrostomy have evolved because of catheter clogging and displacement, which is commonly seen with currently available gastrostomy catheters. Low-profile button gastrostomy catheters, designed to be inserted into mature tracts, have recently been inserted into fresh gastrostomy tracts. Catheter clogging rarely occurs with these low-profile devices. Catheter displacement remains a problem but new buttons can be inserted at the patient's bedside without the nee...

  9. Integrated Approach to Competitive Advantage

    OpenAIRE

    Edita Ragelskaja; Renata Korsakienė

    2011-01-01

    Environmental changes and globalization of markets make an impact on intense competition in almost all business sectors. Evolutionary changes influence companies to learn, adequately react, adapt to environmental changes and to change themselves. Such a situation has revealed the problems of competitive advan­tage of industry companies. Therefore the focus to the factors impacting competitive advantage is seen as timely and relevant. The authors of the paper analyze approaches to competitive ...

  10. Data Integration: Contexts and Approaches

    International Nuclear Information System (INIS)

    The need to share and connect between the heterogeneous data sources is increasing more and more, especially with the growing number of data sources from the Web. For decades, research in the field of information systems have focused on the problem of data sharing in sevaral contexts: federated, mediator and more recently in peer-to-peer and Web data (or linked data sources). In this article, we review these approaches by focusing on data integration in the context of the Web

  11. Inspections - a cost effective approach

    International Nuclear Information System (INIS)

    This paper describes a cost effective approach for inspections of Computerized Nuclear Materials Control and Accounting Systems (CNMCAS). Highlighted is the capability to conduct an inspection program via portable telephone terminals from off-site locations. The program can be applied to various materials management functions including materials control, quality assurance, and materials accounting. The system is designed to facilitate inspections by both external and internal groups

  12. Accident management approach in Armenia

    International Nuclear Information System (INIS)

    In this lecture the accident management approach in Armenian NPP (ANPP) Unit 2 is described. List of BDBAs had been developed by OKB Gydropress in 1994. 13 accident sequences were included in this list. The relevant analyses had been performed in VNIIAES and the 'Guidelines on operator actions for beyond design basis accident (BDBA) management at ANPP Unit 2' had been prepared. These instructions are discussed

  13. Approach to lower back pain.

    Science.gov (United States)

    Moosajee, F; Kalla, A A

    2015-12-01

    Lower back pain is one of the most common symptoms–and the most common musculoskeletal problem–seen by general practitioners. Iti s also a common cause of disability and an expensive condition in terms of economic impact because of absenteeism. This article discusses an approach to this common symptom and how to distinguish the benign, mechanical type of back pain from the more sinister, but less frequently encountered, inflammatory back pain. PMID:26933725

  14. A rational approach to dementia.

    OpenAIRE

    Cole, M G

    1980-01-01

    Dementia is a common problem facing all medical practitioners and it frequently results in hospitalization and death. This review provides a framework for dealing with dementia in clinical practice that is based on both traditional concepts and recent advances in the understanding of the problem. Distinguishing at the bedside between dementia and other disorders of intellect is emphasized. The main causes of dementia and their clinical characteristics are reviewed and a rational approach to d...

  15. Distributed systems an algorithmic approach

    CERN Document Server

    Ghosh, Sukumar

    2006-01-01

    Most applications in distributed computing center around a set of common subproblems. Distributed Systems: An Algorithmic Approach presents the algorithmic issues and necessary background theory that are needed to properly understand these challenges.   Achieving a balance between theory and practice, this book bridges the gap between theoreticians and practitioners. With a set of exercises featured in each chapter, the book begins with background information that contains various interprocess communication techniques and middleware services, followed by foundational topics that cover system

  16. Minimally invasive medial hip approach.

    Science.gov (United States)

    Chiron, P; Murgier, J; Cavaignac, E; Pailhé, R; Reina, N

    2014-10-01

    The medial approach to the hip via the adductors, as described by Ludloff or Ferguson, provides restricted visualization and incurs a risk of neurovascular lesion. We describe a minimally invasive medial hip approach providing broader exposure of extra- and intra-articular elements in a space free of neurovascular structures. With the lower limb in a "frog-leg" position, the skin incision follows the adductor longus for 6cm and then the aponeurosis is incised. A slide plane between all the adductors and the aponeurosis is easily released by blunt dissection, with no interposed neurovascular elements. This gives access to the lesser trochanter, psoas tendon and inferior sides of the femoral neck and head, anterior wall of the acetabulum and labrum. We report a series of 56 cases, with no major complications: this approach allows treatment of iliopsoas muscle lesions and resection or filling of benign tumors of the cervical region and enables intra-articular surgery (arthrolysis, resection of osteophytes or foreign bodies, labral suture). PMID:25164350

  17. Security Management – Systems Approach

    Directory of Open Access Journals (Sweden)

    Milan Kný

    2015-12-01

    Full Text Available The aim of the contribution is the use of the systems approach to treat security management as a practical field and new scientific discipline. The philosophy of systems approach to the solution of problems generally is an adequate methodological basis even for the theory of management. The path to the real optimization of security situation leads only through the holistic and solid solution. Applications of systems analysis and synthesis back up the fact, that systems approach and systems thinking should not absent in security objects. The truthfulness of the claim, that security management is a well-established discipline, depends on ongoing discussion that represents useful process of development of new scientific discipline. At the same time the rationality of science and systematism works as a counterbalance to irrational fear of the whole society, too. Which questions of security remain open in relation to „our interests“? Current problems of Europe should be solved systematically. It is necessary to define the space of interest (territorially the border of the EU or the Schengen area, to implement the system to the object with respect to the borders of the space, to specify the structure and subjects of decision making and implementation.

  18. Manure management. A systems approach.

    Science.gov (United States)

    Grusenmeyer, D C; Cramer, T N

    1997-10-01

    Traditionally, the management of manure nutrients has focused primarily on the production, collection, storage, and field application of manure. By contrast, a total systems approach expands this focus to include concerns about human and animal health, odor and fly control, nutrient import and handling, ration balancing and feeding management to optimize dietary nutrient utilization, management of crop harvest and storage to maximize feed palatability and nutrient digestibility, manure processing for export, farm economics of nutrient management, and the broader economic impacts of environmental regulation and enforcement. In the future, the focus of manure and nutrient management must be to optimize nutrient flow and utilization at every point within the total dairy farm system. A total systems approach to nutrient management is vital to the future of the dairy industry. This approach requires a broad spectrum of scientific expertise that includes multidisciplinary teams involving agronomists, dairy scientists, economists, engineers, microbiologists, soil scientists, veterinarians, and regulators to deal successfully with the complex issues pertaining to dairy nutrient management. PMID:9361237

  19. Technical approach to groundwater restoration

    International Nuclear Information System (INIS)

    The Technical Approach to Groundwater Restoration (TAGR) provides general technical guidance to implement the groundwater restoration phase of the Uranium Mill Tailings Remedial Action (UMTRA) Project. The TAGR includes a brief overview of the surface remediation and groundwater restoration phases of the UMTRA Project and describes the regulatory requirements, the National Environmental Policy Act (NEPA) process, and regulatory compliance. A section on program strategy discusses program optimization, the role of risk assessment, the observational approach, strategies for meeting groundwater cleanup standards, and remedial action decision-making. A section on data requirements for groundwater restoration evaluates the data quality objectives (DQO) and minimum data required to implement the options and comply with the standards. A section on sits implementation explores the development of a conceptual site model, approaches to site characterization, development of remedial action alternatives, selection of the groundwater restoration method, and remedial design and implementation in the context of site-specific documentation in the site observational work plan (SOWP) and the remedial action plan (RAP). Finally, the TAGR elaborates on groundwater monitoring necessary to evaluate compliance with the groundwater cleanup standards and protection of human health and the environment, and outlines licensing procedures

  20. A possibilistic approach to clustering

    Science.gov (United States)

    Krishnapuram, Raghu; Keller, James M.

    1993-01-01

    Fuzzy clustering has been shown to be advantageous over crisp (or traditional) clustering methods in that total commitment of a vector to a given class is not required at each image pattern recognition iteration. Recently fuzzy clustering methods have shown spectacular ability to detect not only hypervolume clusters, but also clusters which are actually 'thin shells', i.e., curves and surfaces. Most analytic fuzzy clustering approaches are derived from the 'Fuzzy C-Means' (FCM) algorithm. The FCM uses the probabilistic constraint that the memberships of a data point across classes sum to one. This constraint was used to generate the membership update equations for an iterative algorithm. Recently, we cast the clustering problem into the framework of possibility theory using an approach in which the resulting partition of the data can be interpreted as a possibilistic partition, and the membership values may be interpreted as degrees of possibility of the points belonging to the classes. We show the ability of this approach to detect linear and quartic curves in the presence of considerable noise.

  1. A Novel Shape Parameterization Approach

    Science.gov (United States)

    Samareh, Jamshid A.

    1999-01-01

    This paper presents a novel parameterization approach for complex shapes suitable for a multidisciplinary design optimization application. The approach consists of two basic concepts: (1) parameterizing the shape perturbations rather than the geometry itself and (2) performing the shape deformation by means of the soft objects animation algorithms used in computer graphics. Because the formulation presented in this paper is independent of grid topology, we can treat computational fluid dynamics and finite element grids in a similar manner. The proposed approach is simple, compact, and efficient. Also, the analytical sensitivity derivatives are easily computed for use in a gradient-based optimization. This algorithm is suitable for low-fidelity (e.g., linear aerodynamics and equivalent laminated plate structures) and high-fidelity analysis tools (e.g., nonlinear computational fluid dynamics and detailed finite element modeling). This paper contains the implementation details of parameterizing for planform, twist, dihedral, thickness, and camber. The results are presented for a multidisciplinary design optimization application consisting of nonlinear computational fluid dynamics, detailed computational structural mechanics, performance, and a simple propulsion module.

  2. String approaches to hadron structure

    International Nuclear Information System (INIS)

    The two principal string approaches to a more realistic dual resonance model are discussed. Firstly, Nambu's proposal of 1974 identifying the Dirac magnetic-monopole string with the dual string, after spontaneous breakdown and the Higgs mechanism in a strong-coupling limit, is investigated. The mathematics underlying Nambu's rather intuitive derivation has been further investigated by Balachandran, Rupertsberger, and Schechter (who put in the vector mass by hand) and independently by Jevicki and Senjanovic (who fully exploit spontaneous breaking and the Higgs mechanism). Here we show that in a leading approximation to the Nambu monopole action the phenomenologically desirable linearity of the leading Regge trajectory seems to be badly violated. Secondly, alternative quantization procedures for the original 1970 Nambu relativistic string action (area of the world sheet) are treated; in particular, a timelike identification of the string time tau which has recently been advocated by Patrascioiu, by Rohrlich, and by Goddard, Hanson, and Ponzano. The most novel of these discussions seems to be that of Rohrlich, who uses a quite different representation for the canonical algebra and the Poincare group. Here we demonstrate, however, that the usual unphysical level spectrum with a massless first excited state emerges as a fully consistent solution even in this approach, and that probably no other solution exists. Finally, the various Nambu string approaches are compared to other attempts to discover the ''right'' model of strong interactions

  3. An abstract approach to music.

    Energy Technology Data Exchange (ETDEWEB)

    Kaper, H. G.; Tipei, S.

    1999-04-19

    In this article we have outlined a formal framework for an abstract approach to music and music composition. The model is formulated in terms of objects that have attributes, obey relationships, and are subject to certain well-defined operations. The motivation for this approach uses traditional terms and concepts of music theory, but the approach itself is formal and uses the language of mathematics. The universal object is an audio wave; partials, sounds, and compositions are special objects, which are placed in a hierarchical order based on time scales. The objects have both static and dynamic attributes. When we realize a composition, we assign values to each of its attributes: a (scalar) value to a static attribute, an envelope and a size to a dynamic attribute. A composition is then a trajectory in the space of aural events, and the complex audio wave is its formal representation. Sounds are fibers in the space of aural events, from which the composer weaves the trajectory of a composition. Each sound object in turn is made up of partials, which are the elementary building blocks of any music composition. The partials evolve on the fastest time scale in the hierarchy of partials, sounds, and compositions. The ideas outlined in this article are being implemented in a digital instrument for additive sound synthesis and in software for music composition. A demonstration of some preliminary results has been submitted by the authors for presentation at the conference.

  4. Proteomic approaches to bacterial differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Norbeck, Angela D.; Callister, Stephen J.; Monroe, Matthew E.; Jaitly, Navdeep; Elias, Dwayne A.; Lipton, Mary S.; Smith, Richard D.

    2006-12-01

    While genomic approaches have been applied for the detection and identification of individual bacteria within microbial communities, analogous proteomics approaches have been effectively precluded due to their inherent complexity. An in silico assessment of peptides that could potentially be present in the proteomes of artificial simple and complex communities was performed to evaluate the effect of proteome complexity on species detection. A mass spectrometry-based proteomics approach was employed to experimentally detect and validate the predicted tryptic peptides initially identified as distinctive within the simple community. An assessment of peptide distinctiveness and the potential for mapping to a particular bacterium within a community was made throughout each step of the study. A second in silico assessment of peptide distinctiveness for a complex community of 25 microorganisms was conducted to investigate the levels of instrumental performance that would be required to experimentally detect these peptides, as well as how performance varied with complexity (e.g., the number of different microorganisms). The experimental data for a simple community showed that it is feasible to predict, observe, and to quantify distinctive peptides from one organism in the presence of at least a 100-fold greater abundance of another, thus yielding putative markers for identifying a bacterium of interest. This work represents a first step towards quantitative proteomic characterization of complex microbial communities and the possible development of community wide markers of perturbations to such communities.

  5. Commercial dissemination approaches for solar home systems

    Energy Technology Data Exchange (ETDEWEB)

    Terrado, E.

    1997-12-01

    The author discusses the issue of providing solar home systems to primarily rural areas from the perspective of how to commercialize the process. He considers two different approaches, one an open market approach and the other an exclusive market approach. He describes examples of the exclusive market approach which are in process in Argentina and Brazil. Coming from a banking background, the business aspects are discussed in detail. He points out the strengths and weaknesses of both approaches toward developing such systems.

  6. Fuzzy multiple linear regression: A computational approach

    Science.gov (United States)

    Juang, C. H.; Huang, X. H.; Fleming, J. W.

    1992-01-01

    This paper presents a new computational approach for performing fuzzy regression. In contrast to Bardossy's approach, the new approach, while dealing with fuzzy variables, closely follows the conventional regression technique. In this approach, treatment of fuzzy input is more 'computational' than 'symbolic.' The following sections first outline the formulation of the new approach, then deal with the implementation and computational scheme, and this is followed by examples to illustrate the new procedure.

  7. Stochastic approach to quantum mechanics

    International Nuclear Information System (INIS)

    A critical review of the Copenhagen interpretation of quantum mechanics, both in its early and later versions, shows that, as a model for the individual system, it suffers from severe conceptual difficulties, particularly with regard to the problem of measurement. Nor are the most common hidden variable interpretations free from complications in providing a physical explanation for the properties of the quantum system. A promising alternative interpretation is the stochastic approach, which presumes that every physical system is continually interacting with a hidden thermostat. This thermostat has a randomizing effect on the position variable and necessitates a probabilistic description of the path of the system. If the concepts of both backward and forward diffusion are utilized, it is possible to construct a straightforward stochastic rule for computing the mean value of any observable which has a classical operational definition. Estimates based upon this rule agree with standard quantum predictions up to second order in momentum but disagree in higher order terms. The rule also predicts the average measurement results for observables which cannot, in general, be estimated by the usual operator formalism. The Schroedinger equation is derivable by the stochastic approach if Newton's Second Law is assumed. Also, quantization of energy and the Heisenberg uncertainty principle are readily explained through the stochastic model, but spatial quantization is not predicted by this method. If the magnitude of the free velocity of the relativistic stochastic particle is assumed to be the speed of light, as in Dirac's relativistic theory of the electron, it is possible to provide a relativistic extension of the stochastic approach and to derive (from this extension) the Klein-Gordon equation

  8. SYNTHETIC APPROACHES TO POLIFUNCTIONALIZED PERHYDRINDANES

    Directory of Open Access Journals (Sweden)

    Veaceslav Kulciţki

    2011-12-01

    Full Text Available The current communication represents an extended abstract of the presentation delivered on the joint Moldo-Italian seminar “New frontiers in natural product chemistry”, held in the Institute of Chemistry, Academy of Sciences of Moldova on 31 September. An overview of the synthetic methods oriented to the synthesis of functionalized terpenic perhydrindanes is provided. Different synthetic strategies are considered, including those based on biomimetic approach. The array of obtained new structures can serve as leads in structure-activity studies as well as useful building blocks towards other perhydrindanes.

  9. Approach to Mars Field Geology

    Science.gov (United States)

    Muehlberger, William; Rice, James W.; Parker, Timothy; Lipps, Jere H.; Hoffman, Paul; Burchfiel, Clark; Brasier, Martin

    1998-01-01

    The goals of field study on Mars are nothing less than to understand the processes and history of the planet at whatever level of detail is necessary. A manned mission gives us an unprecedented opportunity to use the immense power of the human mind to comprehend Mars in extraordinary detail. To take advantage of this opportunity, it is important to examine how we should approach the field study of Mars. In this effort, we are guided by over 200 years of field exploration experience on Earth as well as six manned missions exploring the Moon.

  10. Experimental design a chemometric approach

    CERN Document Server

    Deming, SN

    1987-01-01

    Now available in a paperback edition is a book which has been described as ``...an exceptionally lucid, easy-to-read presentation... would be an excellent addition to the collection of every analytical chemist. I recommend it with great enthusiasm.'' (Analytical Chemistry). Unlike most current textbooks, it approaches experimental design from the point of view of the experimenter, rather than that of the statistician. As the reviewer in `Analytical Chemistry' went on to say: ``Deming and Morgan should be given high praise for bringing the principles of experimental design to the level of the p

  11. Nanothermodynamics: a subdivision potential approach

    Directory of Open Access Journals (Sweden)

    R. Moussavi

    2005-12-01

    Full Text Available  Classical thermodynamic laws and relations have been developed for macroscopic systems that satisfy the thermodynamic limit. These relations are challenged as the system size decreases to the scale of nano-systems, in which thermodynamic properties are overshadowed by system size, and the usual classical concepts of extensivity and intensivity are no longer valid. The challenges to the classical thermodynamics in relation to small systems are demonstrated, and via the approach introduced by Hill, the concept of sub-division potential is clarified in details. The fundamental thermodynamic relations are obtained using a rational-based method.

  12. Computer Networks A Systems Approach

    CERN Document Server

    Peterson, Larry L

    2011-01-01

    This best-selling and classic book teaches you the key principles of computer networks with examples drawn from the real world of network and protocol design. Using the Internet as the primary example, the authors explain various protocols and networking technologies. Their systems-oriented approach encourages you to think about how individual network components fit into a larger, complex system of interactions. Whatever your perspective, whether it be that of an application developer, network administrator, or a designer of network equipment or protocols, you will come away with a "big pictur

  13. Multivariate approaches in plant science

    DEFF Research Database (Denmark)

    Gottlieb, D.M.; Schultz, j.; Bruun, Susanne Wrang;

    2004-01-01

    amount of data. We present a multivariate approach to the handling of data in proteomics with the advantage that protein patterns can be spotted at an early stage and consequently the proteins selected for sequencing can be selected intelligently. These methods can also be applied to other data....... Traditionally statistical methods are not suitable for analysis of the huge amounts of data, where the number of variables exceed the number of objects. Multivariate data analysis, on the other hand, may uncover the hidden structures present in these data. This study takes its starting point in the field...

  14. Waste Characterization: Approaches and Methods

    DEFF Research Database (Denmark)

    Lagerkvist, A.; Ecke, H.; Christensen, Thomas Højlund

    2011-01-01

    is often narrowly defined to meet specific needs for information. This may however limit the general usefulness of the information gained, for example, if the specific purpose limited the characterization to a subset of variables. In general, data available in the solid waste area are limited and often...... with limited representation. This chapter describes common approaches and methods in waste characterization including common terms, sampling, characterization methods and data evaluation. The focus is on the characterization of waste as it is generated or collected, while specific issues on characterization...

  15. HEDR modeling approach: Revision 1

    International Nuclear Information System (INIS)

    This report is a revision of the previous Hanford Environmental Dose Reconstruction (HEDR) Project modeling approach report. This revised report describes the methods used in performing scoping studies and estimating final radiation doses to real and representative individuals who lived in the vicinity of the Hanford Site. The scoping studies and dose estimates pertain to various environmental pathways during various periods of time. The original report discussed the concepts under consideration in 1991. The methods for estimating dose have been refined as understanding of existing data, the scope of pathways, and the magnitudes of dose estimates were evaluated through scoping studies

  16. New Approach to Resonance Crossing

    CERN Document Server

    Franchetti, G

    2012-01-01

    Time varying nonlinear oscillatory systems produce phenomena of resonance crossing and trapping of particles in resonance islands. Traditionally such processes have been analyzed in terms of adiabatic conditions. Considering, as an example, a simplified 1-dimensional (1-D) model describing the “electron cloud pinch” during a bunch passage in a particle accelerator, here we present an approach to resonance trapping which does not require any adiabatic condition. Instead we introduce the concept of attraction point and investigate invariance and scaling properties of motion close to the attraction point, considering a single resonance crossing.

  17. Specialist approaches to managing lipoedema.

    Science.gov (United States)

    Fetzer, Amy

    2016-04-01

    While there is no proven cure for lipoedema, early detection is key as specialist treatments, complemented by self-management techniques, can improve symptoms and prevent progression. There is no universal approach as the correct treatment or treatments will depend on each patient's particular circumstances; however, when chosen early and appropriately, interventions can provide huge benefits. The most common treatments in the management of lipoedema include compression, manual lymphatic drainage (MLD), tumescent liposuction, intermittent pneumatic compression therapy (IPC), kinesio taping, deep oscillation therapy, and cognitive behavioural therapy (CBT). PMID:27046426

  18. Fission approach to cluster radioactivity

    Indian Academy of Sciences (India)

    D N Poenaru; R A Gherghescu

    2015-09-01

    Fission theory is used to explain decay. Also, the analytical superasymmetric fission (ASAF) model is successfully employed to make a systematic search and to predict, with other models, cluster radioactivity. The macroscopic–microscopic method is illustrated for the superheavy nucleus 286Fl. Then a few results of the theoretical approach of decay (ASAF, UNIV and semFIS models), cluster decay (ASAF and UNIV) and spontaneous fission dynamics are described with Werner–Wheeler and cranking inertia. UNIV denotes universal curve and semFIS the fission-based semiempirical formula.

  19. Dental approach to craniofacial syndromes

    DEFF Research Database (Denmark)

    Kjær, Inger

    2012-01-01

    The paper consists of three parts. Part 1: Definition of Syndromes. Focus is given to craniofacial syndromes in which abnormal traits in the dentition are associated symptoms. In the last decade, research has concentrated on phenotype, genotype, growth, development, function, and treatment. Part 2...... distinction is essential for insight into craniofacial syndromes. The dentition, thus, becomes central in diagnostics and evaluation of the pathogenesis. Developmental fields can explore and advance the concept of dental approaches to craniofacial syndromes. Discussion. As deviations in teeth persist and do...

  20. Computational approaches to energy materials

    CERN Document Server

    Catlow, Richard; Walsh, Aron

    2013-01-01

    The development of materials for clean and efficient energy generation and storage is one of the most rapidly developing, multi-disciplinary areas of contemporary science, driven primarily by concerns over global warming, diminishing fossil-fuel reserves, the need for energy security, and increasing consumer demand for portable electronics. Computational methods are now an integral and indispensable part of the materials characterisation and development process.   Computational Approaches to Energy Materials presents a detailed survey of current computational techniques for the

  1. Location theory a unified approach

    CERN Document Server

    Nickel, Stefan

    2006-01-01

    Although modern location theory is now more than 90 years old, the focus of researchers in this area has been mainly problem oriented. However, a common theory, which keeps the essential characteristics of classical location models, is still missing.This monograph addresses this issue. A flexible location problem called the Ordered Median Problem (OMP) is introduced. For all three main subareas of location theory (continuous, network and discrete location) structural properties of the OMP are presented and solution approaches provided. Numerous illustrations and examples help the reader to bec

  2. Operational gaming an international approach

    CERN Document Server

    Ståhl, Ingolf

    1983-01-01

    Operational Gaming: An International Approach focuses on various research on this method of systems analysis. The text points out the value of this method in decision making, planning, and in the implementation of policies. The book presents a survey that highlights the connection of experimental gaming, game theory, and operational gaming. The value of gaming as a balancing method in assessing multifaceted computer models, most notably about their assumptions on human behavior, is noted. The book also offers an overview of gaming in other countries, such as Bulgaria, Soviet Union, and Japan,

  3. A Psycho-Societal Approach

    DEFF Research Database (Denmark)

    Mellon, Karsten

    This is a project about Danish vocational bachelor students admitted on the basis of an Individual Competency Assessment (VPL/IKV) in light of a Psycho-Societal Approach. The core idea of this paper is to present a PhD project which aims to contribute findings regarding students enrolled in a...... Danish vocational Bachelor’s education program (teachers program under the frame of University College) through Validation of Prior Learning by the use of an Individual Competencies Assessment (VPL/IKV)....

  4. Cognitive reasoning a formal approach

    CERN Document Server

    Anshakov, Oleg M

    2010-01-01

    Dealing with uncertainty, moving from ignorance to knowledge, is the focus of cognitive processes. Understanding these processes and modelling, designing, and building artificial cognitive systems have long been challenging research problems. This book describes the theory and methodology of a new, scientifically well-founded general approach, and its realization in the form of intelligent systems applicable in disciplines ranging from social sciences, such as cognitive science and sociology, through natural sciences, such as life sciences and chemistry, to applied sciences, such as medicine,

  5. Fundamental approach to discrete mathematics

    CERN Document Server

    Acharjya, DP

    2009-01-01

    About the Book: The book `Fundamental Approach to Discrete Mathematics` is a required part of pursuing a computer science degree at most universities. It provides in-depth knowledge to the subject for beginners and stimulates further interest in the topic. The salient features of this book include: Strong coverage of key topics involving recurrence relation, combinatorics, Boolean algebra, graph theory and fuzzy set theory. Algorithms and examples integrated throughout the book to bring clarity to the fundamental concepts. Each concept and definition is followed by thoughtful examples.

  6. Review og pattern matching approaches

    DEFF Research Database (Denmark)

    Manfaat, D.; Duffy, Alex; Lee, B. S.

    1996-01-01

    This paper presents a review of pattern matching techniques. The application areas for pattern matching are extensive, ranging from CAD systems to chemical analysis and from manufacturing to image processing. Published techniques and methods are classified and assessed within the context of three...... key issues: pattern classes, similiarity types and mathing methods. It has been shown that the techniques and approaches are as diverse and varied as the applications.......This paper presents a review of pattern matching techniques. The application areas for pattern matching are extensive, ranging from CAD systems to chemical analysis and from manufacturing to image processing. Published techniques and methods are classified and assessed within the context of three...

  7. Software testing a craftsman's approach

    CERN Document Server

    Jorgensen, Paul C

    2011-01-01

    Since the last publication of this international bestseller, software testing has seen a renaissance of renewed interest and technology. The biggest change comes in the growing prominence and acceptance of Agile Programming. Software Testing: A Craftsman's Approach, Third Edition extends the combination of theory and practicality of the first two editions to include agile programming development and discusses the serious effect this emerging area is having on software testing. The third edition of the widely adopted text and reference book is comprised of six parts. It begins by providing the

  8. Adaptive approaches to biosecurity governance.

    Science.gov (United States)

    Cook, David C; Liu, Shuang; Murphy, Brendan; Lonsdale, W Mark

    2010-09-01

    This article discusses institutional changes that may facilitate an adaptive approach to biosecurity risk management where governance is viewed as a multidisciplinary, interactive experiment acknowledging uncertainty. Using the principles of adaptive governance, evolved from institutional theory, we explore how the concepts of lateral information flows, incentive alignment, and policy experimentation might shape Australia's invasive species defense mechanisms. We suggest design principles for biosecurity policies emphasizing overlapping complementary response capabilities and the sharing of invasive species risks via a polycentric system of governance. PMID:20561262

  9. Chemoselective approaches to glycoprotein assembly

    International Nuclear Information System (INIS)

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

  10. The calculus a genetic approach

    CERN Document Server

    Toeplitz, Otto

    2007-01-01

    When first published posthumously in 1963, this book presented a radically different approach to the teaching of calculus.  In sharp contrast to the methods of his time, Otto Toeplitz did not teach calculus as a static system of techniques and facts to be memorized. Instead, he drew on his knowledge of the history of mathematics and presented calculus as an organic evolution of ideas beginning with the discoveries of Greek scholars, such as Archimedes, Pythagoras, and Euclid, and developing through the centuries in the work of Kepler, Galileo, Fermat, Newton, and Leibniz. Through this unique a

  11. Real Analysis A Historical Approach

    CERN Document Server

    Stahl, Saul

    2011-01-01

    A provocative look at the tools and history of real analysis This new edition of Real Analysis: A Historical Approach continues to serve as an interesting read for students of analysis. Combining historical coverage with a superb introductory treatment, this book helps readers easily make the transition from concrete to abstract ideas. The book begins with an exciting sampling of classic and famous problems first posed by some of the greatest mathematicians of all time. Archimedes, Fermat, Newton, and Euler are each summoned in turn, illuminating the utility of infinite, power, and trigonome

  12. Shore approach of Camarupim pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Bernardi, Tiaraju P.; Oliveira Neto, Vasco A. de; Siqueira, Jakson [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    Camarupim Field is located in the northern portion of Espirito Santo Basin and was discovered from the drilling of the well 1-ESS-164 in 2006. It is a gas field which start of the production is in mid of 2009. The production unit will be a FPSO (Floating Production, Storage and Offloading) and the gas will flow through a pipeline with diameter ranging from 12 inches and 24 inches with approximately 60 km long, from the FPSO Cidade de Sao Mateus to UTGC (Unit for Treatment of Gas Cacimbas-Linhares-ES). The FPSO will have processing capacity of 10MMm3/day of gas. Due to the approach of the pipeline in the continental portion, located in an environmental protection area and place of spawning of sea turtles, the connection between the stretch of sea and land pipeline running through a shore approach, known and proven technique of horizontal directional drilling about 950m in length. This paper will be shown the assumptions adopted, the technique employed, the challenges faced by the team and the lessons learned to build the directional hole. (author)

  13. Systematic approach to thermal leptogenesis

    International Nuclear Information System (INIS)

    In this work we study thermal leptogenesis using non-equilibrium quantum field theory. Starting from fundamental equations for correlators of the quantum fields we describe the steps necessary to obtain quantum kinetic equations for quasiparticles. These can easily be compared to conventional results and overcome conceptional problems inherent in the canonical approach. Beyond CP-violating decays we include also those scattering processes which are tightly related to the decays in a consistent approximation of fourth order in the Yukawa couplings. It is demonstrated explicitly how the S-matrix elements for the scattering processes in the conventional approach are related to two- and three-loop contributions to the effective action. We derive effective decay and scattering amplitudes taking medium corrections and thermal masses into account. In this context we also investigate CP-violating Higgs decay within the same formalism. From the kinetic equations we derive rate equations for the lepton asymmetry improved in that they include quantum-statistical effects and medium corrections to the quasiparticle properties.

  14. Interdisciplinary Approach in Engineering Education

    Directory of Open Access Journals (Sweden)

    Anda Zeidmane

    2011-04-01

    Full Text Available The analysis of the scientific literature available on the types of general competences and their classification caused the authors to conclude that it is necessary to implement interdisciplinary approach in engineering education to develop competences necessary for engineers to make them competitive in the labour market. The attention should be paid to a professional foreign language, computer literacy and educational psychology recommendations. To improve professional foreign language skills, CLIL (Content and Language Integrated Learning method should be integrated in the study process of engineering education. In order to develop information literacy competence, it is important to create a single e-study environment. The academic staff, developing study subjects for engineering programmes, should focus on the study content and study methods. As regards the content, the compromise should be sought between fundamental acquisition of the knowledge of the subject matter, the know-how of the application of this knowledge as well as the use of brand new software in the calculations. The paper presents the examples of the application of the interdisciplinary approach in the universities, where the authors of the paper are affiliated: the LUA (Latvia University of Agriculture and the RTU (Riga Technical University, respectively.

  15. Environmental education and indigenous approach

    International Nuclear Information System (INIS)

    Environmental pollution control is the most important and highly discussed issue at the international level. Our and our's next generation survival highly depends on environment. Environmental security is not less important than territorial security. Living in the Competitive trade, Business and Commerce era. WTO threats of globalization to countries like Pakistan require sharp and immediate actions. SOS(Save our Sole) steps should be taken in Environmental Education in order to reorganizing values and clarifying Concepts to develop the necessary skills and attitude necessary to understand and appreciate the interrelatidness among masses, the Cultures and Ecosystem. Historical backgrounds along with different approaches were discussed particularly reference to Pakistan. In this presentation a new but indigenous idea is flashed to improve the environment education system in poor third world countries including Pakistan. Instead of imported ideas, previous implemented as such, indigenous approach highly Perfumed with Islamic, Ideological and cultural blends will do the right job in right direction if employed with true sense of commitment. (author)

  16. Spinal trauma. An imaging approach

    International Nuclear Information System (INIS)

    The diagnosis of trauma to the spine - where the slightest oversight may have catastrophic results - requires a thorough grasp of the spectrum of resultant pathology as well as the imaging modalities used in making an accurate diagnosis. In Spinal Trauma, the internationally renowned team of experts provides a comprehensive, cutting-edge exposition of the current vital role of imaging in the diagnosis and treatment of injuries to the axial skeleton. Beginning with a valuable clinical perspective of spinal trauma, the book offers the reader a unique overview of the biomechanics underlying the pathology of cervical trauma. Acute trauma topics include: - Optimization of imaging modalities - Malalignment - signs and significance - Vertebral fractures - detection and implications - Classification of thoraco-lumbar fractures - rationale and relevance - Neurovascular injury. Distilling decades of clinical and teaching expertise, the contributors further discuss the current role of imaging in special focus topics, which include: - The pediatric spine - Sports injuries - The rigid spine - Trauma in the elderly - Vertebral collapse, benign and malignant - Spinal trauma therapy - Vertebral fractures and osteoporosis - Neuropathic spine. All throughout the book, the focus is on understanding the injury, and its implications and complications, through 'an imaging approach'. Lavishly illustrated with hundreds of superb MR images and CT scans, and clear full-color drawings, the authors conclude with a look into the future, defining clinical trends and research directions. Spinal Trauma - with its broad scope, practical imaging approach, and current focus - is designed to enhance confidence and accuracy, making it essential reading for clinicians and radiologists at all levels. (orig.)

  17. Systematic approach to thermal leptogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Frossard, T.; Kartavtsev, A. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Garny, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hohenegger, A. [Ecole Polytechnique Federale de Lausanne, LPPC, BSP (Switzerland); Mitrouskas, D. [Muenchen Univ. (Germany)

    2012-11-15

    In this work we study thermal leptogenesis using non-equilibrium quantum field theory. Starting from fundamental equations for correlators of the quantum fields we describe the steps necessary to obtain quantum kinetic equations for quasiparticles. These can easily be compared to conventional results and overcome conceptional problems inherent in the canonical approach. Beyond CP-violating decays we include also those scattering processes which are tightly related to the decays in a consistent approximation of fourth order in the Yukawa couplings. It is demonstrated explicitly how the S-matrix elements for the scattering processes in the conventional approach are related to two- and three-loop contributions to the effective action. We derive effective decay and scattering amplitudes taking medium corrections and thermal masses into account. In this context we also investigate CP-violating Higgs decay within the same formalism. From the kinetic equations we derive rate equations for the lepton asymmetry improved in that they include quantum-statistical effects and medium corrections to the quasiparticle properties.

  18. Cardiac imaging. A multimodality approach

    International Nuclear Information System (INIS)

    An excellent atlas on modern diagnostic imaging of the heart Written by an interdisciplinary team of experts, Cardiac Imaging: A Multimodality Approach features an in-depth introduction to all current imaging modalities for the diagnostic assessment of the heart as well as a clinical overview of cardiac diseases and main indications for cardiac imaging. With a particular emphasis on CT and MRI, the first part of the atlas also covers conventional radiography, echocardiography, angiography and nuclear medicine imaging. Leading specialists demonstrate the latest advances in the field, and compare the strengths and weaknesses of each modality. The book's second part features clinical chapters on heart defects, endocarditis, coronary heart disease, cardiomyopathies, myocarditis, cardiac tumors, pericardial diseases, pulmonary vascular diseases, and diseases of the thoracic aorta. The authors address anatomy, pathophysiology, and clinical features, and evaluate the various diagnostic options. Key features: - Highly regarded experts in cardiology and radiology off er image-based teaching of the latest techniques - Readers learn how to decide which modality to use for which indication - Visually highlighted tables and essential points allow for easy navigation through the text - More than 600 outstanding images show up-to-date technology and current imaging protocols Cardiac Imaging: A Multimodality Approach is a must-have desk reference for cardiologists and radiologists in practice, as well as a study guide for residents in both fields. It will also appeal to cardiac surgeons, general practitioners, and medical physicists with a special interest in imaging of the heart. (orig.)

  19. Theoretical approaches to superionic conductivity

    Indian Academy of Sciences (India)

    C S Sunandana; P Senthil Kumar

    2004-02-01

    Recent theoretical approaches to the understanding of superionic conductivity in polycrystalline, glassy and polymeric materials are briefly reviewed. Phase transitions to the superionic conducting state in the AgI family are apparently triggered by cluster formation and strong mobile ion interaction within the clusters. Anomalous conductivity and related physical properties are explained in the cluster induced distortion model. Ionic composites such as AgX : Al2O3 ( = Cl, Br and I) involve conducting and non-conducting phases and the all-important interface between the two whose space charge enhances the conductivity and also trigger phase transitions to exotic polymorphic phases, for which the mechanisms are yet to be explored. Ion hopping dynamics controls the conductivity of superionic glasses. Mode coupling and jump relaxation theories account for the non-Debye relaxation observed in a.c. conductivity of these glasses. The theory of conductivity in polymer electrolytes-still in its infancy-involves their complex structure and glass transition behaviour. Preparative and thermal history, composition and crystallinity control ionic conductivity. New approaches to the synthesis of optimal polymer electrolytes such as rubbery electrolytes, crystalline polymers and nanocomposites must be considered before achieving a comprehensive theoretical understanding.

  20. A new approach to magic

    Directory of Open Access Journals (Sweden)

    Čvorović Jelena

    2006-01-01

    Full Text Available This paper uses the example of traditional practices of magic to suggest ways to incorporate cultural behaviors within the evolutionary paradigm. The first suggestion is to restrict hypotheses to only identifiable variables. This means avoiding the temptation of following the nonevolutionary social sciences in the practice of basing explanations on unverifiable guesses about what beliefs (or memes in evolutionary jargon may or may not inhabit people's brains. In contrast with previous explanations that magical practices result from beliefs and memes whose primarily purpose is to reduce anxiety, we propose that magic is a form of communication that promotes cooperation and often avoids anti-social behavior. This effect of increased cooperation could explain why traditional forms of magic have probably existed and had significant positive consequences for the participants. To be effective as a means of communication, magical rituals must specify both the content of the message and the receiver of the message. Although the content of the communicative message differs with different types of magic, all magical acts serve a purpose to influence the behavior of the party involved and that is the most significant identifiable effect of such behavior. An advantage of this approach over many previous explanations of magic is that because it focuses on identifiable phenomena, the definitions and explanations used in this approach can be falsified.

  1. Immunotherapeutic Approaches to Alzheimer's Disease

    Science.gov (United States)

    Monsonego, Alon; Weiner, Howard L.

    2003-10-01

    Although neurodegenerative diseases such as Alzheimer's disease are not classically considered mediated by inflammation or the immune system, in some instances the immune system may play an important role in the degenerative process. Furthermore, it has become clear that the immune system itself may have beneficial effects in nervous system diseases considered neurodegenerative. Immunotherapeutic approaches designed to induce a humoral immune response have recently been developed for the treatment of Alzheimer's disease. These studies have led to human trials that resulted in both beneficial and adverse effects. In animal models, it has also been shown that immunotherapy designed to induce a cellular immune response may be of benefit in central nervous system injury, although T cells may have either a beneficial or detrimental effect depending on the type of T cell response induced. These areas provide a new avenue for exploring immune system-based therapy of neurodegenerative diseases and will be discussed here with a primary focus on Alzheimer's disease. We will also discuss how these approaches affect microglia activation, which plays a key role in therapy of such diseases.

  2. Phonetic Ambiguity Approaches, Touchstones, Pitfalls and New Approaches

    CERN Document Server

    Juola, P

    1996-01-01

    Phonetic ambiguity and confusibility are bugbears for any form of bottom-up or data-driven approach to language processing. The question of when an input is ``close enough'' to a target word pervades the entire problem spaces of speech recognition, synthesis, language acquisition, speech compression, and language representation, but the variety of representations that have been applied are demonstrably inadequate to at least some aspects of the problem. This paper reviews this inadequacy by examining several touchstone models in phonetic ambiguity and relating them to the problems they were designed to solve. An good solution would be, among other things, efficient, accurate, precise, and universally applicable to representation of words, ideally usable as a ``phonetic distance'' metric for direct measurement of the ``distance'' between word or utterance pairs. None of the proposed models can provide a complete solution to the problem; in general, there is no algorithmic theory of phonetic distance. It is unc...

  3. Environmental management: A system approach

    Science.gov (United States)

    Petak, William J.

    1981-05-01

    This paper presents a system framework whose purpose is to improve understanding of environmental management. By analyzing the links between elements of the environmental management system, it is possible to construct a model that aids thinking systematically about the decision-making subsystem, and other subsystems, of the entire environmental management system. Through a multidisciplinary environmental approach, each of the individual subsystems is able to adapt to threats and opportunities. The fields of government, market economics, social responsibility and ecology, for example, are so complex that it is extremely difficult to develop a framework that gives full consideration to all aspects. This paper, through the application of a highly idealized system framework, attempts to show the general relationships that exist between complex system elements.

  4. A stochastic approach to microphysics

    International Nuclear Information System (INIS)

    The presently widespread idea of ''vacuum population'', together with the quantum concept of vacuum fluctuations leads to assume a random level below that of matter. This stochastic approach starts by a reminder of the author's previous work, first on the relation of diffusion laws with the foundations of microphysics, and then on hadron spectrum. Following the latter, a random quark model is advanced; it gives to quark pairs properties similar to those of a harmonic oscillator or an elastic string, imagined as an explanation to their asymptotic freedom and their confinement. The stochastic study of such interactions as electron-nucleon, jets in e+e- collisions, or pp → π0 + X, gives form factors closely consistent with experiment. The conclusion is an epistemological comment (complementarity between stochastic and quantum domains, E.P.R. paradox, etc...)

  5. A Hamiltonian approach to Thermodynamics

    CERN Document Server

    Baldiotti, M C; Molina, C

    2016-01-01

    In the present work we develop a strictly Hamiltonian approach to Thermodynamics. A thermodynamic description based on symplectic geometry is introduced, where all thermodynamic processes can be described within the framework of Analytic Mechanics. Our proposal is constructed ontop of a usual symplectic manifold, where phase space is even dimensional and one has well-defined Poisson brackets. The main idea is the introduction of an extended phase space where thermodynamic equations of state are realized as constraints. We are then able to apply the canonical transformation toolkit to thermodynamic problems. Throughout this development, Dirac's theory of constrained systems is extensively used. To illustrate the formalism, we consider paradigmatic examples, namely, the ideal, van der Waals and Clausius gases.

  6. A programming approach to computability

    CERN Document Server

    Kfoury, A J; Arbib, Michael A

    1982-01-01

    Computability theory is at the heart of theoretical computer science. Yet, ironically, many of its basic results were discovered by mathematical logicians prior to the development of the first stored-program computer. As a result, many texts on computability theory strike today's computer science students as far removed from their concerns. To remedy this, we base our approach to computability on the language of while-programs, a lean subset of PASCAL, and postpone consideration of such classic models as Turing machines, string-rewriting systems, and p. -recursive functions till the final chapter. Moreover, we balance the presentation of un solvability results such as the unsolvability of the Halting Problem with a presentation of the positive results of modern programming methodology, including the use of proof rules, and the denotational semantics of programs. Computer science seeks to provide a scientific basis for the study of information processing, the solution of problems by algorithms, and the design ...

  7. Topological approach of Jungian psychology.

    Science.gov (United States)

    Viret, Jacques

    2010-09-01

    In this work, we compare two global approaches which are usually considered as completely unconnected one with the other. The former is Thom's topology and the latter is Jung's psychology. More precisely, it seemed to us interesting to adapt some morphologies of Thom's catastrophe theory to some Jung's notions. Thus, we showed that the swallowtail, which is one of these morphologies, was able to describe geometrically the structural organisation of the psyche according to Jung, with its collective unconscious, personal unconscious and conscious. Moreover, we have correlated this morphology with Jung's evolutive processes like individualization and individuation. These comparisons incited us to think that some morphologies of Thom's catastrophe theory are the geometrical dealing of Jung's archetypes. PMID:20658172

  8. Carious dentine removal: current approach

    Directory of Open Access Journals (Sweden)

    Germana Coeli de Farias Sales

    2008-01-01

    Full Text Available Dentistry is renewed day after day through the results of qualified researches. The approach as regards carious dentin removal is goingthrough questioning and innovation. The scope of this study was to perform a literature review in the sense of elucidating questions pertaining to the problem of whether or not it is necessary to completely remove carious dentin, and the possibility of performing restoration in a single session, in addition to a discussion about which type of material should be applied in this type of substrate. After analyzing the referenced articles, it was concluded that the stepwise treatment controls caries progression; there is a trend in the literature to partially remove the carious dentin in deep lesions and perform definitive restoration; Calcium hydroxide cement is a classical liner in these situations, while glass ionomer cement and resinous materials are other possibilities of materials that can be in close contact with the remaining dentin.

  9. Entropy: The Markov Ordering Approach

    CERN Document Server

    Gorban, A N; Judge, G

    2010-01-01

    The focus of this article is on entropy and Markov processes. We study the properties of functionals which are invariant with respect to monotonic transformations and analyze two invariant "additivity" properties: (i) existence of a monotonic transformation which makes the functional additive with respect to the joining of independent systems and (ii) existence of a monotonic transformation which makes the functional additive with respect to the partitioning of the space of states. All Lyapunov functionals for Markov chains which have properties (i) and (ii) are derived. We describe the most general ordering of the distribution space, with respect to which all continuous-time Markov processes are monotonic (the {\\em Markov order}). The solution differs significantly from the ordering given by the inequality of entropy growth. For inference, this approach results in a convex compact set of conditionally "most random" distributions.

  10. Gaze disorders: A clinical approach

    Directory of Open Access Journals (Sweden)

    Pulikottil Wilson Vinny

    2016-01-01

    Full Text Available A single clear binocular vision is made possible by the nature through the oculomotor system along with inputs from the cortical areas as well their descending pathways to the brainstem. Six systems of supranuclear control mechanisms play a crucial role in this regard. These are the saccadic system, the smooth pursuit system, the vestibular system, the optokinetic system, the fixation system, and the vergence system. In gaze disorders, lesions at different levels of the brain spare some of the eye movement systems while affecting others. The resulting pattern of eye movements helps clinicians to localize lesions accurately in the central nervous system. Common lesions causing gaze palsies include cerebral infarcts, demyelinating lesions, multiple sclerosis, tumors, Wernicke's encephalopathy, metabolic disorders, and neurodegenerative disorders such as progressive supranuclear palsy. Evaluation of the different gaze disorders is a bane of most budding neurologists and neurosurgeons. However, a simple and systematic clinical approach to this problem can make their early diagnosis rather easy.

  11. Computational approach to Riemann surfaces

    CERN Document Server

    Klein, Christian

    2011-01-01

    This volume offers a well-structured overview of existent computational approaches to Riemann surfaces and those currently in development. The authors of the contributions represent the groups providing publically available numerical codes in this field. Thus this volume illustrates which software tools are available and how they can be used in practice. In addition examples for solutions to partial differential equations and in surface theory are presented. The intended audience of this book is twofold. It can be used as a textbook for a graduate course in numerics of Riemann surfaces, in which case the standard undergraduate background, i.e., calculus and linear algebra, is required. In particular, no knowledge of the theory of Riemann surfaces is expected; the necessary background in this theory is contained in the Introduction chapter. At the same time, this book is also intended for specialists in geometry and mathematical physics applying the theory of Riemann surfaces in their research. It is the first...

  12. Episodic memory: A comparative approach

    Directory of Open Access Journals (Sweden)

    GemaMartin-Ordas

    1900-01-01

    Full Text Available Historically, episodic memory has been described as autonoetic, personally relevant, complex, context-rich, and allowing mental time travel. In contrast, semantic memory, which is theorized to be free of context and personal relevance, is noetic and consists of general knowledge of facts about the world. The field of comparative psychology has certainly adopted this distinction in order to study episodic memory in non-human animals. Our aim in this article is not only to reflect on the concept of episodic memory and the experimental approaches used in comparative psychology to study this phenomenon, but also to provide a critical analysis of these paradigms. We conclude the article by providing new avenues for future research.

  13. Semiclassical approaches to nuclear dynamics

    CERN Document Server

    Magner, A G; Bartel, J

    2016-01-01

    The extended Gutzwiller trajectory approach is presented for the semiclassical description of nuclear collective dynamics, in line with the main topics of the fruitful activity of V.G. Solovjov. Within the Fermi-liquid droplet model, the leptodermous effective surface approximation was applied to calculations of energies, sum rules and transition densities for the neutron-proton asymmetry of the isovector giant-dipole resonance and found to be in good agreement with the experimental data. By using the Strutinsky shell correction method, the semiclassical collective transport coefficients such as nuclear inertia, friction, stiffness, and moments of inertia can be derived beyond the quantum perturbation approximation of the response function theory and the cranking model.The averaged particle-number dependence of the low-lying collective vibrational states are described in good agreement with basic experimental data, mainly due to an enhancement of the collective inertia as compared to its irrotational flow val...

  14. Lignin Sulfonation - A different Approach

    DEFF Research Database (Denmark)

    Bjørkmann, Anders

    2001-01-01

    The research on sulfite pulping has been characterized by the attempts to explain its chemistry. The. different approach presented is incited by perceptions about the (still) unsolved problem of the ultrastructural features of lignin in wood. A simple kinetic model has been chosen to describe the...... lignin and MWL dissolved (after extraction of the "immediate" lignin) at higher rates than W lignin. For MWL, the rate difference between pH 1.5 and 6 was moderate, compared to W lignin. Borohydride reduction did not affect the lignin dissolution from W, but gave a large decrease of sulfonation rate for...... MWL. Methylation had also a small rate effect for W, but again a large decrease for MWL....

  15. Pharmacotherapy of Schizophrenia: Ploypharmacy Approaches

    Directory of Open Access Journals (Sweden)

    Fatemeh Rahiminejad

    2010-07-01

    Full Text Available "nSchizophrenia is a debilitating illness, rating as one of the leading causes of lost years of quality of life. The illness imposes a disproportionate burden on patients and their families, healthcare systems and society. Pharmacological management is the cornerstone of treatment of schizophrenia, and antipsychotics, both first generation of antipsychotics and second generation of antipsychotics, are efficacious in reducing levels of psychopathology in acute episodes of schizophrenia. Clearly a need for innovative treatment strategies in schizophrenia that will ensure increased effectiveness against negative symptoms and cognitive dysfunction dysfunction. Therefore, in majority of cases polypharmacy is one of the effective approaches. This review focused on polypharmacy in the treatment of schizophrenia and in particular negative symptoms.

  16. Synthetic approaches to multifunctional indenes

    Science.gov (United States)

    López-Pérez, Sara; Dinarès, Immaculada

    2011-01-01

    Summary The synthesis of multifunctional indenes with at least two different functional groups has not yet been extensively explored. Among the plausible synthetic routes to 3,5-disubstituted indenes bearing two different functional groups, such as the [3-(aminoethyl)inden-5-yl)]amines, a reasonable pathway involves the (5-nitro-3-indenyl)acetamides as key intermediates. Although several multistep synthetic approaches can be applied to obtain these advanced intermediates, we describe herein their preparation by an aldol-type reaction between 5-nitroindan-1-ones and the lithium salt of N,N-disubstituted acetamides, followed immediately by dehydration with acid. This classical condensation process, which is neither simple nor trivial despite its apparent directness, permits an efficient entry to a variety of indene-based molecular modules, which could be adapted to a range of functionalized indanones. PMID:22238553

  17. Synthetic approaches to multifunctional indenes

    Directory of Open Access Journals (Sweden)

    Neus Mesquida

    2011-12-01

    Full Text Available The synthesis of multifunctional indenes with at least two different functional groups has not yet been extensively explored. Among the plausible synthetic routes to 3,5-disubstituted indenes bearing two different functional groups, such as the [3-(aminoethylinden-5-yl]amines, a reasonable pathway involves the (5-nitro-3-indenylacetamides as key intermediates. Although several multistep synthetic approaches can be applied to obtain these advanced intermediates, we describe herein their preparation by an aldol-type reaction between 5-nitroindan-1-ones and the lithium salt of N,N-disubstituted acetamides, followed immediately by dehydration with acid. This classical condensation process, which is neither simple nor trivial despite its apparent directness, permits an efficient entry to a variety of indene-based molecular modules, which could be adapted to a range of functionalized indanones.

  18. Lignin Sulfonation - A different Approach

    DEFF Research Database (Denmark)

    Bjørkmann, Anders

    2001-01-01

    The research on sulfite pulping has been characterized by the attempts to explain its chemistry. The. different approach presented is incited by perceptions about the (still) unsolved problem of the ultrastructural features of lignin in wood. A simple kinetic model has been chosen to describe the...... reaction order of lignin as "concentration" (weight) in the dissolution kinetics, the cooking liquor being used in substantial excess. Three states of lignin were used: in wood as sawdust (W), in milled. wood (MW) and as milled wood lignin (MWL). Cooks were performed at pH 1.5, and 6. (measured at room...... temperature). The lignin was also modified chemically in two ways: alkaline borohydride reduction and diazomethane methylation. The reaction order (with the kinetics used) was found to be about 2/3, which is the value to be expected for particles of equal size reacting, at the particle surface. The cooks were...

  19. Queueing networks a fundamental approach

    CERN Document Server

    Dijk, Nico

    2011-01-01

    This handbook aims to highlight fundamental, methodological and computational aspects of networks of queues to provide insights and to unify results that can be applied in a more general manner.  The handbook is organized into five parts: Part 1 considers exact analytical results such as of product form type. Topics include characterization of product forms by physical balance concepts and simple traffic flow equations, classes of service and queue disciplines that allow a product form, a unified description of product forms for discrete time queueing networks, insights for insensitivity, and aggregation and decomposition results that allow subnetworks to be aggregated into single nodes to reduce computational burden. Part 2 looks at monotonicity and comparison results such as for computational simplification by either of two approaches: stochastic monotonicity and ordering results based on the ordering of the proces generators, and comparison results and explicit error bounds based on an underlying Markov r...

  20. Inverse approach to design magnets

    International Nuclear Information System (INIS)

    An inverse approach is always better to design an optimised magnet, where the field profile is known, rather than tuning the geometry of the magnet till the desired profile is achieved. We have developed an optimizer based on standard multi dimensional Newton-Raphson technique. The optimum geometry of a magnet is obtained by a combination of analytical and numerical methods. This code is versatile and can be used to design various magnets used in different applications. Here we present two different cases to show the efficiency of the code. First, we present the design of a solenoid magnet for a.c. susceptibility set up. Second, we describe the design of two pairs of Helmholtz coils for ion beam deflection. (author)

  1. New approaches to hydrogen storage.

    Science.gov (United States)

    Graetz, Jason

    2009-01-01

    The emergence of a Hydrogen Economy will require the development of new media capable of safely storing hydrogen in a compact and light weight package. Metal hydrides and complex hydrides, where hydrogen is chemically bonded to the metal atoms in the bulk, offer some hope of overcoming the challenges associated with hydrogen storage. The objective is to find a material with a high volumetric and gravimetric hydrogen density that can also meet the unique demands of a low temperature automotive fuel cell. Currently, there is considerable effort to develop new materials with tunable thermodynamic and kinetic properties. This tutorial review provides an overview of the different types of metal hydrides and complex hydrides being investigated for on-board (reversible) and off-board (non-reversible) hydrogen storage along with a few new approaches to improving the hydrogenation-dehydrogenation properties. PMID:19088966

  2. RBE from a microdosimetric approach

    International Nuclear Information System (INIS)

    This report reviews the current status of microdosimetry and knowledge regarding the response of biological systems to radiation fields of differing linear energy transfer (LET). The primary objective is to investigate the potential application to radon daughter lung dosimetry. The concept of track structure and its statistical behaviour is discussed and applied to estimate the yield of double strand breaks (DSBs). The general microdosimetric approach to modelling radiation response is presented in terms of the hit-size effectiveness function and the behaviour for specific proposed functions is examined. Radiobiological investigations of the DSB, chromosome aberration and oncogenic transformation end points are reviewed with emphasis on recent developments. A simplified model system is developed illustrating the potential for analysis of the risk from radon daughter inhalation and published research directed towards this goal is discussed. (author). 66 refs., 3 tabs., 17 figs

  3. Steganography and Steganalysis: Different Approaches

    CERN Document Server

    Das, Soumyendu; Bandyopadhyay, Bijoy; Sanyal, Sugata

    2011-01-01

    Steganography is the technique of hiding confidential information within any media. Steganography is often confused with cryptography because the two are similar in the way that they both are used to protect confidential information. The difference between the two is in the appearance in the processed output; the output of steganography operation is not apparently visible but in cryptography the output is scrambled so that it can draw attention. Steganlysis is process to detect of presence of steganography. In this article we have tried to elucidate the different approaches towards implementation of steganography using 'multimedia' file (text, static image, audio and video) and Network IP datagram as cover. Also some methods of steganalysis will be discussed.

  4. Statistical Physics Approaches to Seismicity

    CERN Document Server

    Sornette, D

    2008-01-01

    This entry in the Encyclopedia of Complexity and Systems Science, Springer present a summary of some of the concepts and calculational tools that have been developed in attempts to apply statistical physics approaches to seismology. We summarize the leading theoretical physical models of the space-time organization of earthquakes. We present a general discussion and several examples of the new metrics proposed by statistical physicists, underlining their strengths and weaknesses. The entry concludes by briefly outlining future directions. The presentation is organized as follows. I Glossary II Definition and Importance of the Subject III Introduction IV Concepts and Calculational Tools IV.1 Renormalization, Scaling and the Role of Small Earthquakes in Models of Triggered Seismicity IV.2 Universality IV.3 Intermittent Periodicity and Chaos IV.4 Turbulence IV.5 Self-Organized Criticality V Competing mechanisms and models V.1 Roots of complexity in seismicity: dynamics or heterogeneity? V.2 Critical earthquakes ...

  5. Molecular approaches for bacterial azoreductases

    Directory of Open Access Journals (Sweden)

    Montira Leelakriangsak

    2013-12-01

    Full Text Available Azo dyes are the dominant types of synthetic dyes, widely used in textiles, foods, leather, printing, tattooing, cosmetics, and pharmaceutical industries. Many microorganisms are able to decolorize azo dyes, and there is increasing interest in biological waste treatment methods. Bacterial azoreductases can cleave azo linkages (-N=N- in azo dyes, forming aromatic amines. This review mainly focuses on employing molecular approaches, including gene manipulation and recombinant strains, to study bacterial azoreductases. The construction of the recombinant protein by cloning and the overexpression of azoreductase is described. The mechanisms and function of bacterial azoreductases can be studied by other molecular techniques discussed in this review, such as RT-PCR, southern blot analysis, western blot analysis, zymography, and muta-genesis in order to understand bacterial azoreductase properties, function and application. In addition, understanding the regulation of azoreductase gene expression will lead to the systematic use of gene manipulation in bacterial strains for new strategies in future waste remediation technologies.

  6. Elliptic curves a computational approach

    CERN Document Server

    Schmitt, Susanne; Pethö, Attila

    2003-01-01

    The basics of the theory of elliptic curves should be known to everybody, be he (or she) a mathematician or a computer scientist. Especially everybody concerned with cryptography should know the elements of this theory. The purpose of the present textbook is to give an elementary introduction to elliptic curves. Since this branch of number theory is particularly accessible to computer-assisted calculations, the authors make use of it by approaching the theory under a computational point of view. Specifically, the computer-algebra package SIMATH can be applied on several occasions. However, the book can be read also by those not interested in any computations. Of course, the theory of elliptic curves is very comprehensive and becomes correspondingly sophisticated. That is why the authors made a choice of the topics treated. Topics covered include the determination of torsion groups, computations regarding the Mordell-Weil group, height calculations, S-integral points. The contents is kept as elementary as poss...

  7. Diffraction operators in paraxial approach

    Science.gov (United States)

    Lasso, William; Navas, Marianela; Añez, Liz; Urdaneta, Romer; Díaz, Leonardo; Torres, César O.

    2014-07-01

    Nowadays, research in the field of science education points to the creation of alternative ways of teaching contents encouraging the development of more elaborate reasoning, where a high degree of abstraction and generalization of scientific knowledge prevails. On that subject, this research shows a didactic alternative proposal for the construction of Fresnel and Fraunhoffer diffraction concepts applying the Fourier transform technique in the study of electromagnetic waves propagation in free space. Curvature transparency and Fourier sphere operators in paraxial approximation are used in order to make the usual laborious mathematical approach easier. The main result shows that the composition of optic metaxial operators results in the discovery of a simpler way out of the standard electromagnetic wave propagation in free space between a transmitter and a receptor separated from a given distance. This allows to state that the didactic proposal shown encourages the construction of Fresnel and Fraunhoffer diffraction concepts in a more effective and easier way than the traditional teaching.

  8. Percutaneous approach and transseptal catheterization

    International Nuclear Information System (INIS)

    In contrast, with the direct brachial technique, the percutaneous approach to left and right heart catheterizaiton involves achieving vascular access via needle puncture, obviating surgical isolation of the vessel during either the introduction or subsequent withdrawal of the cardiac catheter. With appropriate skill and knowledge of regional anatomy, the percutaneous technique can be adapted to catheter insertion from a variety of entry sites. Venous catheterization can be performed via the femoral, internal jugular, subclavian, or median antecubital vein, whereas arterial catheterization can be performed via the femoral, brachial, or axillary artery. At the termination of the procedure, the catheters and introducing sheaths are withdrawn, and bleeding from the puncture sites is controlled by the application of direct pressure

  9. An Environmentalist Approach: Green Design

    Directory of Open Access Journals (Sweden)

    Gulay Coskun Kasap

    2011-04-01

    Full Text Available A product interacts with the environment throughout the entire life cycle- from the design phase to disposal phase- and every product makes different environmental impacts in different life cycle stages. Thus, reducing the environmental impact of a product by just focusing on the waste that is produced after the production process, is not possible. For this, a holistic and proactive approach adoption is required which considers the entire life of a product from raw materials that will be used in production to wastes occurred in production process, from packages to recovery of end of life products. This will be possible by “Green Design” which integrates the product and process design with environmental issues.

  10. Approaches to resolving trade disputes.

    Science.gov (United States)

    Wilson, D W; Thiermann, A B

    2003-08-01

    The authors discuss the various approaches to resolving trade disputes available to Member Countries of the OIE (World organisation for animal health). The paper first describes the rights and obligations of Member Countries in setting health measures for the importation of animals and animal products, according to the provisions of the World Trade Organization (WTO) Agreement on the Application of Sanitary and Phytosanitary Measures (the SPS Agreement). The authors indicate how OIE standards may be used to set import measures and introduce issues such as equivalence and the use of provisional measures, which are both areas of potential conflict. The authors then describe the options available for resolving disputes--bilateral discussions, mediation through the OIE, the use of the WTO SPS Committee and the formal WTO dispute settlement process, discussing the advantages and disadvantages of each. PMID:15884603

  11. Ontology Partitioning: Clustering Based Approach

    Directory of Open Access Journals (Sweden)

    Soraya Setti Ahmed

    2015-05-01

    Full Text Available The semantic web goal is to share and integrate data across different domains and organizations. The knowledge representations of semantic data are made possible by ontology. As the usage of semantic web increases, construction of the semantic web ontologies is also increased. Moreover, due to the monolithic nature of the ontology various semantic web operations like query answering, data sharing, data matching, data reuse and data integration become more complicated as the size of ontology increases. Partitioning the ontology is the key solution to handle this scalability issue. In this work, we propose a revision and an enhancement of K-means clustering algorithm based on a new semantic similarity measure for partitioning given ontology into high quality modules. The results show that our approach produces meaningful clusters than the traditional algorithm of K-means.

  12. Crohn's disease: current imaging approach

    International Nuclear Information System (INIS)

    Purpose: This paper discusses the role of different imaging modalities in the diagnostic work-up of Crohn's disease (CD). Methods: We present a concept, which emphasizes different diagnostic aspects with regard to primary diagnosis, follow-up and assessment of complications of CD. The most effective imaging approach to various diagnostic problems of CD is discussed in detail. Discussion: With regard to the primary diagnosis barium studies should contribute to differentiate between CD and ulcerative colitis. Beyond that, these studies should evaluate location and extent of disease. During the follow-up bowel sonography provides staging of disease and enables the detection of complications at an early stage. CT is a valuable tool in the preoperative assessment of complications, such as fistuale and abscesses. (orig.)

  13. Managerial Leadership - A Theoretical Approach

    Directory of Open Access Journals (Sweden)

    Felicia Cornelia MACARIE

    2007-06-01

    Full Text Available The paper endeavors to offer an overview of the major theories on leadership and the way in which it influences the management of contemporary organizations. Numerous scholars highlight that there are numerous overlaps between the concepts of management and leadership. This is the reason why the first section of the paper focuses on providing an extensive overview of the literature regarding the meaning of the two aforementioned concepts. The second section addresses more in depth the concept of leadership and managerial leadership and focuses on the ideal profile of the leader. The last section of the paper critically discusses various types of leadership and more specifically modern approaches to the concept and practices of leadership.

  14. IAEA safeguards approaches and goals

    International Nuclear Information System (INIS)

    IAEA safeguards provide a technical means of verifying that political obligations undertaken by States party to international agreements relating to the peaceful uses of nuclear energy are being honored. The Agency assures the international community that States party to Safeguards Agreements are complying with their undertaking not to use facilities and divert nuclear materials from peaceful uses to the manufacture of nuclear explosive devices. The task of IAEA safeguards can be summed up as to detect diversion of nuclear materials committed to peaceful uses of nuclear energy, or the misuse of equipment or facilities subject to certain safeguards agreements, and to deter such diversion or misuse through the risk of early detection. This lecture concentrates on the factors the Agency takes into account in designing and implementing safeguards approaches at facilities. (author)

  15. Gaze disorders: A clinical approach.

    Science.gov (United States)

    Vinny, Pulikottil Wilson; Lal, Vivek

    2016-01-01

    A single clear binocular vision is made possible by the nature through the oculomotor system along with inputs from the cortical areas as well their descending pathways to the brainstem. Six systems of supranuclear control mechanisms play a crucial role in this regard. These are the saccadic system, the smooth pursuit system, the vestibular system, the optokinetic system, the fixation system, and the vergence system. In gaze disorders, lesions at different levels of the brain spare some of the eye movement systems while affecting others. The resulting pattern of eye movements helps clinicians to localize lesions accurately in the central nervous system. Common lesions causing gaze palsies include cerebral infarcts, demyelinating lesions, multiple sclerosis, tumors, Wernicke's encephalopathy, metabolic disorders, and neurodegenerative disorders such as progressive supranuclear palsy. Evaluation of the different gaze disorders is a bane of most budding neurologists and neurosurgeons. However, a simple and systematic clinical approach to this problem can make their early diagnosis rather easy. PMID:26755003

  16. An Effective Approach to Teaching Electrochemistry.

    Science.gov (United States)

    Birss, Viola I.; Truax, D. Rodney

    1990-01-01

    An approach which may be useful for teaching electrochemistry in freshman college chemistry courses is presented. Discussed are the potential problems with teaching this subject and solutions provided by this approach. (CW)

  17. My Approaches to Promote Teaching Efficiency

    Institute of Scientific and Technical Information of China (English)

    李娟维

    2014-01-01

    Promoting teaching efficiency is a matter of the utmost concern of all teachers. This paper focuses on the different approaches that the author adopts in her teaching. These approaches include creating learning situations,using humor in teaching.

  18. Symbolic Tensor Calculus -- Functional and Dynamic Approach

    CERN Document Server

    Woszczyna, A; Czaja, W; Golda, Z A

    2016-01-01

    In this paper, we briefly discuss the dynamic and functional approach to computer symbolic tensor analysis. The ccgrg package for Wolfram Language/Mathematica is used to illustrate this approach. Some examples of applications are attached.

  19. A Zen Approach to Volunteer Management.

    Science.gov (United States)

    Barnett, Michael L.; Cahill, Gloria

    2002-01-01

    New York University's Zen approach to community service focuses on the principles of mindfulness, awareness, compassion, and engagement in the present moment. It enables a more holistic approach to the measurement of volunteer management objectives. (SK)

  20. A STRATEGIC APPROACH OF MANAGEMENT ACCOUNTING

    OpenAIRE

    Grosu Corina; Almasan Alina Carmen

    2009-01-01

    For a long time, management accounting has been used based on a predominantly technical approach which strictly aimed at computing the costs. Gradually, to the management accounting it has been added a decisional approach aimed at influencing the behaviou

  1. A Brief Overview of Communicative Approach

    Institute of Scientific and Technical Information of China (English)

    任永东

    2013-01-01

    Communicative Approach has become a popular teaching strategy.This essay mainly reviews and introduces the development and the features of Communicative Approach in order to apply this teaching methodology in English teaching for students’better learning results.

  2. A New Approach for Calculating Vacuum Susceptibility

    Institute of Scientific and Technical Information of China (English)

    宗红石; 平加伦; 顾建中

    2004-01-01

    Based on the Dyson-Schwinger approach, we propose a new method for calculating vacuum susceptibilities. As an example, the vector vacuum susceptibility is calculated. A comparison with the results of the previous approaches is presented.

  3. Computational Approaches to Vestibular Research

    Science.gov (United States)

    Ross, Muriel D.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    The Biocomputation Center at NASA Ames Research Center is dedicated to a union between computational, experimental and theoretical approaches to the study of neuroscience and of life sciences in general. The current emphasis is on computer reconstruction and visualization of vestibular macular architecture in three-dimensions (3-D), and on mathematical modeling and computer simulation of neural activity in the functioning system. Our methods are being used to interpret the influence of spaceflight on mammalian vestibular maculas in a model system, that of the adult Sprague-Dawley rat. More than twenty 3-D reconstructions of type I and type II hair cells and their afferents have been completed by digitization of contours traced from serial sections photographed in a transmission electron microscope. This labor-intensive method has now been replace d by a semiautomated method developed in the Biocomputation Center in which conventional photography is eliminated. All viewing, storage and manipulation of original data is done using Silicon Graphics workstations. Recent improvements to the software include a new mesh generation method for connecting contours. This method will permit the investigator to describe any surface, regardless of complexity, including highly branched structures such as are routinely found in neurons. This same mesh can be used for 3-D, finite volume simulation of synapse activation and voltage spread on neuronal surfaces visualized via the reconstruction process. These simulations help the investigator interpret the relationship between neuroarchitecture and physiology, and are of assistance in determining which experiments will best test theoretical interpretations. Data are also used to develop abstract, 3-D models that dynamically display neuronal activity ongoing in the system. Finally, the same data can be used to visualize the neural tissue in a virtual environment. Our exhibit will depict capabilities of our computational approaches and

  4. Synthesis and Characterization of Hydrophilic Tri-block Polylactide Copolymer%亲水性聚乳酸嵌段共聚物制备及表征

    Institute of Scientific and Technical Information of China (English)

    强涛; 陈卫星; 石玉; 李朝

    2009-01-01

    为改善聚乳酸的亲水性,采用自制的OH-PLA-OH和CAC为原料,制备Cl-PLA-Cl,以此作为大分子引发剂、以CuBr/2,2'-联吡啶为催化体系进行NVP的ATRP,制备三嵌段共聚物PVP-b-PLA-b-PVP.研究了制备PVP-b-PLA-b-PVP的最佳反应物用量及共聚物的亲水性与降解性能.结果表明,反应物料的最佳用量为Cl-PLA-Cl 4.17 g,NVP 11.12 g,CuBr 0.29 g,2,2'-联吡啶0.62 g,环己酮30 mL.PVP-b-PLA-b-PVP的亲水性较PLA有明显提高.共聚物在NaOH溶液中的降解速率最快,磷酸盐缓冲液中最慢.该方法是改善聚乳酸亲水性的一条较好的途径.%Novel hydrophilic tri-block copolymers of poly-N-vinylpyrrolidone and polylactide were synthesized by ATRP using N-vinylpyrrolidone as the monomer and polylactide-terminated with chlorides as the functional macroinitiator, which was prepared by reacting the hydroxyls-terminated polylactide oligomer with chloroacetic chloride in the presence of CuBr/2, 2'-bipyridine as catalyst. The hydrophilicity and the degradability of the copolymer films were investigated. The results showed that the hydrophilicity of the copolymer was much higher than that of PLA homo-polymer. The target copolymers PVP-b-PLA-b-PVP was degraded more rapidly than PLA. The degradation of copolymer in NaOH solution was more rapidly than in HCI solution, H2O and phosphate buffer solution. This method was a good way to improve PLA's hydrophilicity.

  5. Valuing Public Goods: The Life Satisfaction Approach

    OpenAIRE

    Luechinger, Bruno S Frey, Simon; Stutzer, Alois

    2004-01-01

    "This paper discusses a novel approach to elicit people’s preferences fornpublic goods, namely the life satisfaction approach. Reported subjective well-beingndata are used to directly evaluate utility consequences of public goods. The strengthsnof this approach are compared to traditional approaches and identification issues arenaddressed. Moreover, it is applied to estimate utility losses caused by terroristnactivities in France, the UK and the Republic of Ireland. Terrorism in these co...

  6. Valuing Public Goods: The Life Satisfaction Approach

    OpenAIRE

    Frey, Bruno S.; Luechinger, Simon; Stutzer, Alois

    2004-01-01

    This paper discusses a novel approach to elicit people�s preferences for public goods, namely the life satisfaction approach. Reported subjective well-being data are used to directly evaluate utility consequences of public goods. The strengths of this approach are compared to traditional approaches and identification issues are addressed. Moreover, it is applied to estimate utility losses caused by terrorist activities in France, the UK and the Republic of Ireland. Terrorism in these countr...

  7. A systems approach to traditional oriental medicine

    DEFF Research Database (Denmark)

    Kim, Hyun Uk; Ryu, Jae Yong; Lee, Jong Ok;

    2015-01-01

    Analyzing structural similarities between compounds derived from traditional oriental medicine and human metabolites is a systems-based approach that can help identify mechanisms of action and suggest approaches to reduce toxicity.......Analyzing structural similarities between compounds derived from traditional oriental medicine and human metabolites is a systems-based approach that can help identify mechanisms of action and suggest approaches to reduce toxicity....

  8. Sustainability economics, ontology and the capability approach

    OpenAIRE

    Martins, Nuno O.

    2011-01-01

    Copyright © 2011 Elsevier B.V. All rights reserved. The relationship between sustainability economics and the capability approach has recently been explored. Here I shall discuss this relationship, and argue that a study of the ontology underlying the capability approach can help us to see more clearly the interconnections between sustainability economics and the capability approach. In particular, the interpretations of the capability approach as an ontological exercise, which have recent...

  9. A comprehensive approach to nuclear arms control

    International Nuclear Information System (INIS)

    Cold war nuclear arms control was characterized by American Soviet hostility and the limits of verification; the end of the cold war allowed for a more cooperative approach. From this new situation emerged the idea of a new agenda for arms control and of exploring a more comprehensive approach to nuclear arms control. The author posits eight elements for such a comprehensive approach. Though such an approach seems unrealistic today, recent history teaches us to look beyond today's constraints. (author)

  10. Anterior approach v. posterior approach - ultrasound-guided shoulder arthrogram injection

    OpenAIRE

    Merle Neethling-du Toit; Richard de villiers

    2008-01-01

    Anterior approach ultrasound guided arthrogram injections are a quick reliable way of injecting contrast prior to MRI scan. We did a retrospective study on patients, previously injected and scanned at our clinic, to compare the more manifested posterior approach with the anterior approach. The success rate for successful intra-articular injections for the anterior approach far outweighs the posterior approach. Also the anterior approach is more tolerable for patients as the injections are muc...

  11. The Large Context Problem (LCP) Approach

    Science.gov (United States)

    Stinner, Arthur

    2006-01-01

    This article traces the development of a contextual approach to the teaching of science (physics) subsequently called the Large Context Problem (LCP) approach. This approach is based on the general observation that learning could be well motivated by a context with one unifying central idea capable of capturing the imagination of the students. The…

  12. A Nonviolent Approach to Social Justice Education

    Science.gov (United States)

    Wang, Hongyu

    2013-01-01

    This article advocates a nonviolent approach to social justice education. First, social justice education literature is reviewed, and two contrasting and influential approaches--critical theory and poststructural theory--are the focus of critical analysis. A nonviolent approach is proposed as an alternative. Second, the notion of social justice is…

  13. An Attributional Approach to Counselor Attractiveness.

    Science.gov (United States)

    Hackman, Hollis W.; Claiborn, Charles D.

    1982-01-01

    Examined two components of counselor attractiveness--perceived similarity and liking--in a comparison of two theoretical approaches to attractiveness and influence in counseling--the referent power hypothesis and an attributional approach. Results generally support the attributional approach over the reference power hypothesis. (Author)

  14. About Radiation Reaction with Force Approach

    CERN Document Server

    Velazquez, Gustavo Lopez

    2015-01-01

    The difficulty of usual approach to radiation reaction is pointed out , and a possible approach based on the force acting to the charged particle which produces the acceleration itself, is presented. This approach brings about an expression such that acceleration is zero whenever the external force is zero.

  15. Nonlinear approaches in engineering applications 2

    CERN Document Server

    Jazar, Reza N

    2013-01-01

    Provides updated principles and applications of the nonlinear approaches in solving engineering and physics problems Demonstrates how nonlinear approaches may open avenues to better, safer, cheaper systems with less energy consumption Has a strong emphasis on the application, physical meaning, and methodologies of nonlinear approaches in different engineering and science problems

  16. Materiality in a Practice-Based Approach

    Science.gov (United States)

    Svabo, Connie

    2009-01-01

    Purpose: The paper aims to provide an overview of the vocabulary for materiality which is used by practice-based approaches to organizational knowing. Design/methodology/approach: The overview is theoretically generated and is based on the anthology Knowing in Organizations: A Practice-based Approach edited by Nicolini, Gherardi and Yanow. The…

  17. Anterior approach v. posterior approach - ultrasound-guided shoulder arthrogram injection

    Directory of Open Access Journals (Sweden)

    Merle Neethling-du Toit

    2008-11-01

    Full Text Available Anterior approach ultrasound guided arthrogram injections are a quick reliable way of injecting contrast prior to MRI scan. We did a retrospective study on patients, previously injected and scanned at our clinic, to compare the more manifested posterior approach with the anterior approach. The success rate for successful intra-articular injections for the anterior approach far outweighs the posterior approach. Also the anterior approach is more tolerable for patients as the injections are much quicker and seemingly less painful. In our knowledge it is thus far better to perform anterior approach shoulder arthrogram injections than posterior approach injections

  18. An intelligent approach to nanotechnology

    Science.gov (United States)

    Demming, Anna

    2013-11-01

    Control counts for little without a guiding principle. Whether manipulating atoms with a scanning probe or controlling carrier concentration in thin film deposition, intelligent intervention is required to steer the process from aimless precision towards a finely optimized design. In this issue G M Sacha and P Varona describe how artificial intelligence approaches can help towards modelling and simulating nanosystems, increasing our grasp of the nuances of these systems and how to optimize them for specific applications [1]. More than a labour-saving technique their review also suggests how genetic algorithms and artificial neural networks can supersede existing capabilities to tackle some of the challenges in moving a range of nanotechnologies forward. Research has made giant strides in determining not just what system parameters enhance performance but how. Nanoparticle synthesis is a typical example, where the field has shifted from simple synthesis and observation to unearthing insights as to dominating factors that can be identified and enlisted to control the morphological and chemical properties of synthesized products. One example is the neat study on reaction media viscosity for silver nanocrystal synthesis, where Park, Im and Park in Korea demonstrated a level of size control that had previously proved hard to achieve [2]. Silver nanoparticles have many potential applications including catalysis [3], sensing [4] and surface enhanced Raman scattering [5]. In their study, Park and colleagues obtain size-controlled 30 nm silver nanocrystals in a viscosity controlled medium of 1,5-pentanediol and demonstrate their use as sacrificial cores for the fabrication of a low-refractive filler. Another nanomaterial that has barely seen an ebb in research activity over the past two decades is ZnO, with a legion of reports detailing how to produce ZnO in different nanoscale forms from rods [6], belts [7] and flowers [8] to highly ordered arrays of vertically aligned

  19. Two approaches to physics tutoring

    Science.gov (United States)

    Solomaniuck, Tania

    One in two first-year students at science or biomedical faculties fail in basic subjects such as mathematics, chemistry or physics. Course-specific tutoring is one of the available means for improving their performance. In the present research, two tutoring models are developed. Both incorporate independent learning, but from different perspectives and priorities. A pragmatic tutoring approach. The first part of the thesis describes the search process for an optimal course-specific tutoring strategy for a standard first-year physics course in life sciences curricula. After a number of empirical research rounds, a pragmatic compromise emerged as the most suitable form of tutoring. The approach is characterised by: (1) priority to questions from students; (2) a high degree of interactivity with the tutor and among students; (3) due consideration to the number of questions to be dealt with and the depth in which they should be discussed. Most students participating in the tutoring sessions expressed their satisfaction and performed sufficiently well in their exams. However, there was still a problem: the students' insight into the course material was restricted to first-order processing of the syllabus. While this would be satisfactory in non-scientific study programmes, it is deemed insufficient in programmes where deeper insight is required in order that students be able to deal adequately with new conceptual questions or problems. In-depth tutoring. In science programmes, the core objective is for students to acquire in-depth knowledge. Therefore, science educators are designing and studying teaching methods that are geared not only to the acquisition of in-depth knowledge as such, but also to the motivation of students to take a more in-depth approach to learning. Some of the crucial notions in their research are: the extent to which the course content ties in with students' prior knowledge, problem-setting strategies and concept-context linking. 'In

  20. Computational Approaches to Vestibular Research

    Science.gov (United States)

    Ross, Muriel D.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    The Biocomputation Center at NASA Ames Research Center is dedicated to a union between computational, experimental and theoretical approaches to the study of neuroscience and of life sciences in general. The current emphasis is on computer reconstruction and visualization of vestibular macular architecture in three-dimensions (3-D), and on mathematical modeling and computer simulation of neural activity in the functioning system. Our methods are being used to interpret the influence of spaceflight on mammalian vestibular maculas in a model system, that of the adult Sprague-Dawley rat. More than twenty 3-D reconstructions of type I and type II hair cells and their afferents have been completed by digitization of contours traced from serial sections photographed in a transmission electron microscope. This labor-intensive method has now been replace d by a semiautomated method developed in the Biocomputation Center in which conventional photography is eliminated. All viewing, storage and manipulation of original data is done using Silicon Graphics workstations. Recent improvements to the software include a new mesh generation method for connecting contours. This method will permit the investigator to describe any surface, regardless of complexity, including highly branched structures such as are routinely found in neurons. This same mesh can be used for 3-D, finite volume simulation of synapse activation and voltage spread on neuronal surfaces visualized via the reconstruction process. These simulations help the investigator interpret the relationship between neuroarchitecture and physiology, and are of assistance in determining which experiments will best test theoretical interpretations. Data are also used to develop abstract, 3-D models that dynamically display neuronal activity ongoing in the system. Finally, the same data can be used to visualize the neural tissue in a virtual environment. Our exhibit will depict capabilities of our computational approaches and

  1. Computational Approaches to Vestibular Research

    Science.gov (United States)

    Ross, Muriel D.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    The Biocomputation Center at NASA Ames Research Center is dedicated to a union between computational, experimental and theoretical approaches to the study of neuroscience and of life sciences in general. The current emphasis is on computer reconstruction and visualization of vestibular macular architecture in three-dimensions (3-D), and on mathematical modeling and computer simulation of neural activity in the functioning system. Our methods are being used to interpret the influence of spaceflight on mammalian vestibular maculas in a model system, that of the adult Sprague-Dawley rat. More than twenty 3-D reconstructions of type I and type II hair cells and their afferents have been completed by digitization of contours traced from serial sections photographed in a transmission electron microscope. This labor-intensive method has now been replace d by a semiautomated method developed in the Biocomputation Center in which conventional photography is eliminated. All viewing, storage and manipulation of original data is done using Silicon Graphics workstations. Recent improvements to the software include a new mesh generation method for connecting contours. This method will permit the investigator to describe any surface, regardless of complexity, including highly branched structures such as are routinely found in neurons. This same mesh can be used for 3-D, finite volume simulation of synapse activation and voltage spread on neuronal surfaces visualized via the reconstruction process. These simulations help the investigator interpret the relationship between neuroarchitecture and physiology, and are of assistance in determining which experiments will best test theoretical interpretations. Data are also used to develop abstract, 3-D models that dynamically display neuronal activity ongoing in the system. Finally, the same data can be used to visualize the neural tissue in a virtual environment. Our exhibit will depict capabilities of our computational approaches and

  2. Computational Approaches to Vestibular Research

    Science.gov (United States)

    Ross, Muriel D.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    The Biocomputation Center at NASA Ames Research Center is dedicated to a union between computational, experimental and theoretical approaches to the study of neuroscience and of life sciences in general. The current emphasis is on computer reconstruction and visualization of vestibular macular architecture in three-dimensions (3-D), and on mathematical modeling and computer simulation of neural activity in the functioning system. Our methods are being used to interpret the influence of spaceflight on mammalian vestibular maculas in a model system, that of the adult Sprague-Dawley rat. More than twenty 3-D reconstructions of type I and type II hair cells and their afferents have been completed by digitization of contours traced from serial sections photographed in a transmission electron microscope. This labor-intensive method has now been replace d by a semiautomated method developed in the Biocomputation Center in which conventional photography is eliminated. All viewing, storage and manipulation of original data is done using Silicon Graphics workstations. Recent improvements to the software include a new mesh generation method for connecting contours. This method will permit the investigator to describe any surface, regardless of complexity, including highly branched structures such as are routinely found in neurons. This same mesh can be used for 3-D, finite volume simulation of synapse activation and voltage spread on neuronal surfaces visualized via the reconstruction process. These simulations help the investigator interpret the relationship between neuroarchitecture and physiology, and are of assistance in determining which experiments will best test theoretical interpretations. Data are also used to develop abstract, 3-D models that dynamically display neuronal activity ongoing in the system. Finally, the same data can be used to visualize the neural tissue in a virtual environment. Our exhibit will depict capabilities of our computational approaches and

  3. A Novel Approach for Solving Semidefinite Programs

    Directory of Open Access Journals (Sweden)

    Hong-Wei Jiao

    2014-01-01

    Full Text Available A novel linearizing alternating direction augmented Lagrangian approach is proposed for effectively solving semidefinite programs (SDP. For every iteration, by fixing the other variables, the proposed approach alternatively optimizes the dual variables and the dual slack variables; then the primal variables, that is, Lagrange multipliers, are updated. In addition, the proposed approach renews all the variables in closed forms without solving any system of linear equations. Global convergence of the proposed approach is proved under mild conditions, and two numerical problems are given to demonstrate the effectiveness of the presented approach.

  4. Logical and epistemological approach to critical thinking

    Directory of Open Access Journals (Sweden)

    Pešić Jelena

    2007-01-01

    Full Text Available Two main approaches in the conceptualization of critical thinking, logical and epistemological, are presented and analyzed in this paper. The review of logical approach begins with defining its general framework (relationship between critical thinking and informal logic and afterwards we analyze abilities and skills which are seen as basic constituents of critical thinking. In the review of epistemological approach we analyze four conceptions that present the main directions in criticizing logical approach, and also in developing the broader perspective on critical thinking that includes specific view of knowledge and its development, noncognitive dispositions and the role of subject based knowledge. At the end, we discuss the relationship between logical and epistemological approach. We claim and justify that they should be understood as complementary approaches, and we consider specific contribution of each approach to comprehensive definition of critical thinking. .

  5. Hybrid Multiprocessor Real-Time Scheduling Approach

    Directory of Open Access Journals (Sweden)

    Ali A Safaei

    2011-03-01

    Full Text Available Real-time scheduling is one of the most important aspects of a real-time system design. To achieve a real-time system's requirement, especially to be fast, multiprocessor systems are used. Generally, multiprocessor real-time scheduling algorithms fall into one the two well-known approaches: Partitioning or Global. The partitioning approach has acceptable overhead for underlying system but can NOT guarantee to provide an optimal schedule. The global approach can provide this guarantee by holding some preconditions and considerable overheads. In this paper, an intermediate hybrid multiprocessor real-time scheduling approach is proposed in which optimality will be reached via the minimum overheads for underlying system. Presenting and analyzing different feasible paradigms for combination of the two existing approaches, the proposed hybrid approach satisfies the two major goals of this combination: optimality and lightweightness. Experimental results show that the hybrid approach outperforms the two existing ones.

  6. Natural approach to quantum dissipation

    Science.gov (United States)

    Taj, David; Öttinger, Hans Christian

    2015-12-01

    The dissipative dynamics of a quantum system weakly coupled to one or several reservoirs is usually described in terms of a Lindblad generator. The popularity of this approach is certainly due to the linear character of the latter. However, while such linearity finds justification from an underlying Hamiltonian evolution in some scaling limit, it does not rely on solid physical motivations at small but finite values of the coupling constants, where the generator is typically used for applications. The Markovian quantum master equations we propose are instead supported by very natural thermodynamic arguments. They themselves arise from Markovian master equations for the system and the environment which preserve factorized states and mean energy and generate entropy at a non-negative rate. The dissipative structure is driven by an entropic map, called modular, which introduces nonlinearity. The generated modular dynamical semigroup (MDS) guarantees for the positivity of the time evolved state the correct steady state properties, the positivity of the entropy production, and a positive Onsager matrix with symmetry relations arising from Green-Kubo formulas. We show that the celebrated Davies Lindblad generator, obtained through the Born and the secular approximations, generates a MDS. In doing so we also provide a nonlinear MDS which is supported by a weak coupling argument and is free from the limitations of the Davies generator.

  7. Australia: Approaching an energy crossroads

    International Nuclear Information System (INIS)

    This paper considers energy policy in Australia in the context of its considerable energy resources, climate change and a recent change in government. It examines the possible paths that future energy use and policy in Australia could take, including published projections based largely on a 'business as usual' approach and projections based on a dramatic shift towards more efficient use of energy and renewable energy technologies. It also considers the various factors affecting future policy direction, including energy security, the advocacy in Australia for establishing nuclear electricity generation and other parts of the nuclear fuel-cycle, responses to climate change, and carbon sequestration. It concludes that while the Australian Government is currently reluctant to move away from a dependence on coal, and unlikely to adopt nuclear energy generation, a low-emissions future without waiting for the deployment of carbon capture and storage and without resorting to nuclear power is within reach. However, in the face of strong pressure from interest groups associated with energy intensive industry, making the necessary innovations will require further growth of community concern about climate change, and the development of greater understanding of the feasibility of employing low carbon-emissions options.

  8. New Approaches to Social Economy

    Directory of Open Access Journals (Sweden)

    Daniela VÎRJAN

    2012-06-01

    Full Text Available Social economy is a relatively new phenomenon, having started just a few decades ago, and due to this reason it has yet to reach great scale. Due to the phenomenon of global crisis propagation, the economies of all countries have been affected and have gone into an economical cycle recession phase, some economical agents hitting the climax of the crisis, practically shutting down their activities. Starting from this, some social problems started to accentuate: the number of unemployed people has risen, the poverty rate went up, the marginalization and social exclusion rates went up, the aging of the population has increased, the discrepancy between the rich and poor has widened and so on, and in this context social economy has gained a greater importance not only at an European level but also at an international level. As such, social economy may become one of the innovative and creative solutions which can contribute to a more human approach to economical problems, combining freedom of market with social responsibility to the benefit of the whole community.

  9. Current Approach to Child Rights

    Directory of Open Access Journals (Sweden)

    Huseyin Dag

    2015-03-01

    Full Text Available Rights of children, legally or morally all over the world that children are born with; education, health, life, shelter; physical, psychological or sexual exploitation protection of such rights is universal concept used to describethemall. Rights of children is an issue that should be addressed in the concept of human rights. Today, there are many parts of the world that human rights violations, child-size and grew broader, more difficult to intervene in a way that is situated. The idea that children than in adults of different physical, physiological, behavioral and psychological characteristics that continuous growth and improve dawareness that the establishment of thecare of children a society where the problem is and scientific approach everyone with this responsibility should be installed is shaped in Geneva Declaration of Childrens Rights. Today, the international document related to childrens rights is the United Nations Convention on the Rights of the Child adoptedand approved by 193 countries. Child policy in Turkey where 25 million children live is an issue that should be seriously considered. Thus, childrens rights, children working in coordination with the contract on the basis of a policy should be implemented fully. [Cukurova Med J 2015; 40(1.000: 1-5

  10. Understanding Progress: A Heterodox Approach

    Directory of Open Access Journals (Sweden)

    Blanca Lemus

    2013-01-01

    Full Text Available This paper examines the possibility of understanding and measuring well-being as a result of “progress” on the basis of today’s dominant epistemological framework. Market criteria distort social values by allowing purchasing power to define priorities, likening luxury goods to basic needs; in the process they reinforce patterns of discrimination against disadvantaged social groups and women, introducing fatal distortions into the analysis. Similarly, because there are no appropriate mechanisms to price natural resources adequately, the market overlooks the consequences of the abuse of natural resources, degrading the quality of life, individually and collectively, or—in the framework of Latin American indigenous groups—foreclosing the possibility of “living well”. We critique the common vision of the official development discourse that places its faith on technological innovations to resolve these problems. The analysis points to the need for new models of social and environmental governance to promote progress, approaches like those suggested in the paper that are inconsistent with public policies currently in place. At present, the social groups forging institutions to assure their own well-being and ecological balance are involved in local processes, often in opposition to the proposals of the political leaders in their countries.

  11. Stepwise approach for view synthesis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper presents some techniques for synthesizing novel view for a virtual viewpoint from two given views captured at different viewpoints to achieve both high quality and high efficiency. The whole process consists of three passes. The first pass recovers depth map. We formulate it as pixel labelling and propose a bisection approach to solve it. It is accomplished in log2n (n is the number of depth levels) steps, each of which involves a single graph cut computation. The second pass detects occluded pixels and reasons about their depth. It fits a foreground depth curve and a background depth curve using depth of nearby foreground and background pixels, and then distinguishes foreground and background pixels by minimizing a global energy, which involves only one graph cut computation. The third pass finds for each pixel in the novel view the corresponding pixels in the input views and computes its color. The whole process involves only a small number of graph cut computations, therefore it is efficient.And, visual artifacts in the synthesized view can be removed successfully by correcting depth of the occluded pixels. Experimental results demonstrate that both high quality and high efficiency are achieved by the proposed techniques.

  12. Fulfillment Request Management (The approach

    Directory of Open Access Journals (Sweden)

    Stylianos Gkoutzioupas

    2014-02-01

    Full Text Available In this paper we introduce the term FRM (Fulfillment Request Management. According to the FRM in a BSS / OSS environment we can use a unified approach to implement a SOA in order to integrate BSS with OSS and handle 1. Orders 2. Events 3. Processes. So in a way that systems like ESB, Order Management, and Business Process Management can be implemented under a unified architecture and a unified implementation. We assume that all the above mentioned are 'requests' and according to the system we want to implement, the request can be an event, an order, a process etc. So instead of having N systems we have 1 system that covers all the above (ESB, Order Management, BPM etc With the FRM we can have certain advantages such as: 1. adaptation 2. Interoperability. 3. Re-usability 4. Fast implementation 5. Easy reporting. In this paper we present a set of the main principles in order to build an FRM System.

  13. Diagnostic approach to peripheral neuropathy

    Directory of Open Access Journals (Sweden)

    Misra Usha

    2008-01-01

    Full Text Available Peripheral neuropathy refers to disorders of the peripheral nervous system. They have numerous causes and diverse presentations; hence, a systematic and logical approach is needed for cost-effective diagnosis, especially of treatable neuropathies. A detailed history of symptoms, family and occupational history should be obtained. General and systemic examinations provide valuable clues. Neurological examinations investigating sensory, motor and autonomic signs help to define the topography and nature of neuropathy. Large fiber neuropathy manifests with the loss of joint position and vibration sense and sensory ataxia, whereas small fiber neuropathy manifests with the impairment of pain, temperature and autonomic functions. Electrodiagnostic (EDx tests include sensory, motor nerve conduction, F response, H reflex and needle electromyography (EMG. EDx helps in documenting the extent of sensory motor deficits, categorizing demyelinating (prolonged terminal latency, slowing of nerve conduction velocity, dispersion and conduction block and axonal (marginal slowing of nerve conduction and small compound muscle or sensory action potential and dennervation on EMG. Uniform demyelinating features are suggestive of hereditary demyelination, whereas difference between nerves and segments of the same nerve favor acquired demyelination. Finally, neuropathy is classified into mononeuropathy commonly due to entrapment or trauma; mononeuropathy multiplex commonly due to leprosy and vasculitis; and polyneuropathy due to systemic, metabolic or toxic etiology. Laboratory investigations are carried out as indicated and specialized tests such as biochemical, immunological, genetic studies, cerebrospinal fluid (CSF examination and nerve biopsy are carried out in selected patients. Approximately 20% patients with neuropathy remain undiagnosed but the prognosis is not bad in them.

  14. Reactor Protection Systems. Diverse Approaches

    International Nuclear Information System (INIS)

    Defence in depth design criteria applied to nuclear instrumentation, in particular, to reactor protection systems (RPS), include redundancy, diversity and fail-safe behaviour. Typically, two out of three ('2oo3'), majority-voting systems meet redundancy criteria. A careful analysis of signal levels and polarity and the use of several techniques, such as lives zeros, bias toward safe state, etc. guarantee the same degree of fail-safe behaviour. Diversity criteria, in general, are met by the whole system using more than one method to protect the integrity of reactor (i.e. rod drop plus boron injection), but not for the single instrumentation chain. Moreover, the increasing information needs of supervision systems encourage the use of digital instrumentation in RPS; if the digital instrumentation has software based implementation, the diversity requirement will be mandatory for the instrumentation of each system. In the paper, three possible configurations of the first protection system (rod drop) are analysed. The first one is the traditional hardware approach, the second one is a software based system, and the last one is a proposed mix system. For all configurations, a redundant system two out of four ('2oo4') is assumed. Availability and reliability points of view are taken into account. The proposed mix system is explained in full detail. A discussion about programmable logic and its considerations are introduced. A CPLD based system in a research reactor (RA1) and its functionality are explained. (author)

  15. Dosimetric approaches: pregnancy and lactation

    International Nuclear Information System (INIS)

    The female nuclear medicine patient is of special concern to the evaluation of radiation dose since radiation protection point of view: a)- The females overall body size and organ sizes are generally smaller than those of her male counterpart (thus her radiation doses will be higher, given the same amounts of administered activity and similar biokinetics), the effective doses could be 25 per cent higher than a man; b)- Female gonads are inside the body instead of outside and are near several organs often important as source organs in internal dosimetry; female gonads doses could be up to 10 or 30 higher than male gonads (usually 3 order); c)- Risk of breast cancer is significantly higher among females than males; d)- During the pregnancy due to placental transfer of radiopharmaceuticals or radiation exposure from the urinary bladder the embryo/fetus could receive doses that must be avoid; e)- In the case of nursing infant is of special concern in such an analysis to determine the interruption period to avoid doses in the nursing infant. The dosimetric approaches to take account to assess internal doses in the pregnant woman and during the breast feeding are discussed. (author)

  16. Repository Closure and Sealing Approach

    International Nuclear Information System (INIS)

    The scope of this analysis will be to develop the conceptual design of the closure seals and their locations in the Subsurface Facilities. The design will be based on the recently established program requirements for transitioning to the Site Recommendation (SR) design as outlined by ''Approach to Implementing the Site Recommendation Baseline'' (Stroupe 2000) and the ''Monitored Geologic Repository Project Description Document'' (CRWMS M andO 1999b). The objective of this analysis will be to assist in providing a description for the Subsurface Facilities System Description Document, Section 2 and finally to document any conclusions reached in order to contribute and provide support to the SR. This analysis is at a conceptual level and is considered adequate to support the SR design. The final closure barriers and seals for the ventilation shafts, and the north and south ramps will require these openings to be permanently sealed to limit excessive air and water inflows and prevent human intrusion. The major tasks identified with closure in this analysis are: (1) Developing the overall subsurface seal layout and identifying design and operational interfaces for the Subsurface Facilities. (2) Summarizing the general site conditions and general rock characteristic with respect to seal location and describing the seal selected. (3) Identify seal construction materials, methodology of construction and strategic locations including design of the seal and plugs. (4) Discussing methods to prevent human intrusion

  17. The wonder approach to learning

    Directory of Open Access Journals (Sweden)

    Catherine L'Ecuyer

    2014-10-01

    Full Text Available Wonder, innate in the child, is an inner desire to learn that awaits reality in order to be awakened. Wonder is at the origin of reality-based consciousness, thus of learning. The scope of wonder, which occurs at a metaphysical level, is greater than that of curiosity. Unfortunate misinterpretations of neuroscience have led to false brain-based ideas in the field of education, all of these based on the scientifically wrong assumption that children’s learning depends on an enriched environment. These beliefs have re-enforced the Behaviorist Approach to education and to parenting and have contributed to deadening our children’s sense of wonder. We suggest wonder as the center of all motivation and action in the child. Wonder is what makes life genuinely personal. Beauty is what triggers wonder. Wonder attunes to beauty through sensitivity and is unfolded by attachment. When wonder, beauty, sensitivity and secure attachment are present, learning is meaningful. On the contrary, when there is no volitional dimension involved (no wonder, no end or meaning (no beauty and no trusting predisposition (secure attachment, the rigid and limiting mechanical process of so-called learning through mere repetition become a deadening and alienating routine. This could be described as training, not as learning, because it does not contemplate the human being as a whole.

  18. The Wonder Approach to learning.

    Science.gov (United States)

    L'Ecuyer, Catherine

    2014-01-01

    Wonder, innate in the child, is an inner desire to learn that awaits reality in order to be awakened. Wonder is at the origin of reality-based consciousness, thus of learning. The scope of wonder, which occurs at a metaphysical level, is greater than that of curiosity. Unfortunate misinterpretations of neuroscience have led to false brain-based ideas in the field of education, all of these based on the scientifically wrong assumption that children's learning depends on an enriched environment. These beliefs have re-enforced the Behaviorist Approach to education and to parenting and have contributed to deadening our children's sense of wonder. We suggest wonder as the center of all motivation and action in the child. Wonder is what makes life genuinely personal. Beauty is what triggers wonder. Wonder attunes to beauty through sensitivity and is unfolded by secure attachment. When wonder, beauty, sensitivity and secure attachment are present, learning is meaningful. On the contrary, when there is no volitional dimension involved (no wonder), no end or meaning (no beauty) and no trusting predisposition (secure attachment), the rigid and limiting mechanical process of so-called learning through mere repetition become a deadening and alienating routine. This could be described as training, not as learning, because it does not contemplate the human being as a whole. PMID:25339882

  19. Innovative approach towards understanding optics

    Science.gov (United States)

    Garg, Amit; Bharadwaj, Sadashiv Raj; Kumar, Raj; Shudhanshu, Avinash Kumar; Verma, Deepak Kumar

    2016-01-01

    Over the last few years, there has been a decline in the students’ interest towards Science and Optics. Use of technology in the form of various types of sensors and data acquisition systems has come as a saviour. Till date, manual routine tools and techniques are used to perform various experimental procedures in most of the science/optics laboratories in our country. The manual tools are cumbersome whereas the automated ones are costly. It does not enthuse young researchers towards the science laboratories. There is a need to develop applications which can be easily integrated, tailored at school and undergraduate level laboratories and are economical at the same time. Equipments with advanced technologies are available but they are uneconomical and have complicated working principle with a black box approach. The present work describes development of portable tools and applications which are user-friendly. This is being implemented using open-source physical computing platform based on a simple low cost microcontroller board and a development environment for writing software. The present paper reports the development of an automated spectrometer, an instrument used in almost all optics experiments at undergraduate level, and students’ response to this innovation. These tools will inspire young researchers towards science and facilitate development of advance low cost equipments making life easier for Indian as well as developing nations.

  20. Batch Scheduling a Fresh Approach

    Science.gov (United States)

    Cardo, Nicholas P.; Woodrow, Thomas (Technical Monitor)

    1994-01-01

    The Network Queueing System (NQS) was designed to schedule jobs based on limits within queues. As systems obtain more memory, the number of queues increased to take advantage of the added memory resource. The problem now becomes too many queues. Having a large number of queues provides users with the capability to gain an unfair advantage over other users by tailoring their job to fit in an empty queue. Additionally, the large number of queues becomes confusing to the user community. The High Speed Processors group at the Numerical Aerodynamics Simulation (NAS) Facility at NASA Ames Research Center developed a new approach to batch job scheduling. This new method reduces the number of queues required by eliminating the need for queues based on resource limits. The scheduler examines each request for necessary resources before initiating the job. Also additional user limits at the complex level were added to provide a fairness to all users. Additional tools which include user job reordering are under development to work with the new scheduler. This paper discusses the objectives, design and implementation results of this new scheduler