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Sample records for abs terpolymer estudo

  1. Terpolymers

    Directory of Open Access Journals (Sweden)

    M.A. Semsarzadeh

    2009-12-01

    Full Text Available The microstructure and thermal properties of the synthesized block copolymers and terpolymers via atom transfer radical polymerization (ATRP were studied. The mole fraction of the blocks and chain length of the PVAc-b-PMA block copolymers were estimated with 1H NMR spectroscopy.Differential scanning calorimety measurement shows two different transitions at 36°C and 8°C assigned to PVAc and PMA blocks. Thermogravimetric analysis demonstrated the similar thermal degradation behavior of the block copolymers and a three-step degradation around 238, 295 and 345°C were attributed to dechlorination step and decomposition of the PVAc and PMA blocks. Study of thermal properties of PVAc-b-Poly(MA-co-MMA copolymers indicated that glass transition temperature of second block increased from 49°C to 91°C with increase in MMA mole fraction from 0.358 to 0.733. The losses in the thermal degradation of block terpolymers were similar, and the higher thermal degredation temperature of MA unit has delayed the thermal degredation temperature of MMA in copolymer.

  2. Ionizing radiation effect study by electron beam on acrylonitrile butadiene styrene - ABS terpolymer

    International Nuclear Information System (INIS)

    Landi, Tania Regina Lourenco

    2003-01-01

    The great advantage in the researches involving development has as objective to increase significantly the quality of the products. The ABS (acrylonitrile, butadiene, styrene) resins are terpolymers formed by an elastomer and two thermoplastics amorphous components. The three different monomeric units from the terpolymer ABS contribute separately to the material characteristics exhibited. The molecular stiffness originating from polystyrene and the benzene ring hanging on the chain is responsible for the flexion module ABS. The acrylonitrile and the styrene incorporated butadiene exercises strong influence in the resistance to the impact because it reduces the bonding among them. The engineering use of this terpolymer became important due their mechanical properties and mainly, for the responses of this to tensions or deformations applied. The polymeric materials, when submitted to the ionizing radiation are modified by the transference of energy to these materials, introducing excitation and ionization of the molecules, generating chemical reactions that can produce permanent modifications in the polymeric physicochemical structure. The induced modifications can result in the polymeric material degradation or crosslinking, which can result in the improvement of some properties. This work has, as objective, to study the electron beam ionizing radiation effect, at different doses, in the properties of the polymer ABS. The studied properties were: tensile strength at break, elongation at break, Izod impact strength, flexural strength, melt flow index, Vicat softening temperature and the thermic distortion temperature. Also researches on Differential Scanning Calorimetry (DSC) and Thermogravimetric Analyses (TGA) were accomplished. From the experimental results, it was showed that for doses until 500 kGy, at 22.6 kGy/s dose rate, in the presence of air, the crosslinking process of ABS prevails. (author)

  3. Estudo ab-initio da a-alanina em meio aquoso

    Directory of Open Access Journals (Sweden)

    Sambrano Júlio Ricardo

    1999-01-01

    Full Text Available Ab initio Hartree-Fock (HF, Density Functional (B3LYP and electron correlation (MP2 methods have been used to caracterize the aqueous medium intramolecular hydrogen bond in a-alanine. The 6-31G* and 6-31++G** were taken from Gaussian94 library. We were concerned on the structure of three conformers of a-alanine, in their neutral form plus on the structure of the zwitterionic form (Z. The Z structure is a stationary point at the HF/6-31G* level but it is not when diffuse functions and electron correlation are included. This results shows that the Z form does not exist in the gas phase. The inclusion of solvent effects changed significantly the results obtained in gas phase, therefore this inclusion make the Z form a stationary point within all level of theory, and the relative energy depends dramatically on the level of calculation.

  4. Notch sensitivity of aliphatic polyketone terpolymers

    NARCIS (Netherlands)

    Zuiderduin, W.C.J.; Huetink, Han; Gaymans, R.J.

    2004-01-01

    The notch sensitivity of aliphatic polyketone (PK) terpolymers was investigated in this article. The notch-tip radius was varied between the size of an actual propagating crack tip of 1-2 m and the largest notch tip of 1000 m radius. The larger notch-tip radii (1000-15 m) were milled into the

  5. Dinâmica molecular ab initio:aplicações ao estudo de propriedades electrónicas de sistemas moleculares

    OpenAIRE

    Martiniano, Hugo Filipe de Mesquita Costa, 1978-

    2013-01-01

    Tese de doutoramento, Química (Química-Física), Universidade de Lisboa, Faculdade de Ciências, 2013 O método da dinâmica molecular ab initio exibe vantagens significativas para o estudo da estrutura e propriedades electrónicas de sistemas moleculares complexos. No entanto, uma das suas desvantagens é o elevado custo computacional, quando comparado com os métodos de dinâmica molecular clássicos. Um dos modos de resolver este problema é adoptar uma abordagem sequencial, na qual a dinâmica é ...

  6. Synthesis of Well-Defined Polyethylene-Based 3-Miktoarm Star Copolymers and Terpolymers

    KAUST Repository

    Zhang, Zhen

    2016-03-25

    Novel polyethylene (PE)-based 3-miktoarm star copolymers A2B, (AB)2B and terpolymers (AC)2(BC) [A: PE; B, C: polystyrene (PS) or poly(methyl methacrylate) (PMMA)] were synthesized by combining boron chemistry, polyhomologation, and atom transfer radical polymerization (ATRP). 1,4-Pentadiene-3-yl 2-bromo-2-methylpropanoate was first synthesized followed by hydroboration with thexylborane to afford B-thexylboracyclanes, a multi-heterofunctional initiator with two initiating sites for polyhomologation and one for ATRP. After polyhomologation of dimethylsulfoxonium methylide the α,ω-dihydroxyl polyethylene (PE-OH)2-Br produced served as macroinitiator for the ATRP of styrene to afford (PE-OH)2-(PS-Br). Both (PE-OH)2-Br and (PE-OH)2-(PS-Br) were transformed to two new trifunctional macroinitiators (PE-Br)2-Br and (PE-Br)2-(PS-Br) through esterification reactions and used for the synthesis of (AB)2B and (AC)2(BC) 3-miktoarm star co/terpolymers. All intermediates and final products were characterized by 1H NMR, high temperature gel permeation chromatography (HT-GPC), and differential scanning calorimetry (DSC). The synthetic method is a general one and can be used for the synthesis of complex PE-based architectures by combination with other living/living-controlled polymerization techniques. © 2016 American Chemical Society.

  7. Well-Defined Cyclic Triblock Terpolymers: A Missing Piece of the Morphology Puzzle

    KAUST Repository

    Polymeropoulos, George; Bilalis, Panayiotis; Hadjichristidis, Nikolaos

    2016-01-01

    Two well-defined cyclic triblock terpolymers, missing pieces of the terpolymer morphology puzzle, consisting of poly(isoprene), polystyrene, and poly(2-vinylpyridine), were synthesized by combining the Glaser coupling reaction with anionic

  8. Well-Defined Cyclic Triblock Terpolymers: A Missing Piece of the Morphology Puzzle

    KAUST Repository

    Polymeropoulos, George

    2016-10-27

    Two well-defined cyclic triblock terpolymers, missing pieces of the terpolymer morphology puzzle, consisting of poly(isoprene), polystyrene, and poly(2-vinylpyridine), were synthesized by combining the Glaser coupling reaction with anionic polymerization. An α,ω-dihydroxy linear triblock terpolymer (OH-PI1,4-b-PS-b-P2VP-OH) was first synthesized followed by transformation of the OH to alkyne groups by esterification with pentynoic acid and cyclization by Glaser coupling. The size exclusion chromatography (SEC) trace of the linear terpolymer precursor was shifted to lower elution time after cyclization, indicating the successful synthesis of the cyclic terpolymer. Additionally, the SEC trace of the cyclic terpolymer produced, after cleavage of the ester groups, shifted again practically to the position corresponding to the linear precursor. The first exploratory results on morphology showed the tremendous influence of the cyclic structure on the morphology of terpolymers. © 2016 American Chemical Society.

  9. Free radical and thermal curing of terpyridine-modified terpolymers

    NARCIS (Netherlands)

    Hofmeier, H.; El-Ghayoury, A.; Schubert, U.S.

    2004-01-01

    Terpolymers bearing terpyridine as well as (meth)acrylates as free radical curable groups (UV-curing) or hydroxyl groups (thermal curing with bis-isocyanates) were synthesized and characterized using 1H NMR, IR and UV-vis spectroscopy as well as GPC. Subsequently, the ability of covalent

  10. Mechanical properties of polyketone terpolymer/rubber blends

    NARCIS (Netherlands)

    Zuiderduin, W.C.J.; Vlasveld, D.P.N.; Huetink, Han; Gaymans, R.J.

    2004-01-01

    Blends of aliphatic polyketone terpolymer and a core-shell rubber (CSR) were melt processed with varying CSR concentration of 0– 40 wt%. The obtained morphology was of finely dispersed CSR particles in the polyketone matrix. The thermal properties of the matrix polymer remained unaffected by the

  11. Superhydrophobic terpolymer nanofibers containing perfluoroethyl alkyl methacrylate by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Cengiz, Ugur, E-mail: ucengiz@gyte.edu.tr [Department of Chemical Engineering, Gebze Institute of Technology, Cayirova, 41400 Kocaeli (Turkey); Avci, Merih Z. [Polymer Science and Technology, Deparment of Chemistry, Istanbul Technical University, Maslak 34469, Istanbul (Turkey); Erbil, H. Yildirim [Department of Chemical Engineering, Gebze Institute of Technology, Cayirova, 41400 Kocaeli (Turkey); Sarac, A. Sezai [Polymer Science and Technology, Deparment of Chemistry, Istanbul Technical University, Maslak 34469, Istanbul (Turkey)

    2012-05-15

    A new statistical terpolymer containing perfluoroethyl alkyl methacrylate (Zonyl-TM), methyl methacrylate and butyl acrylate, poly(Zonyl-TM-ran-MMA-ran-BA) was synthesized in supercritical carbon dioxide at 200 bar and 80 Degree-Sign C using AIBN as an initiator by heterogeneous free radical copolymerization. Nanofibers of this terpolymer were produced by electrospinning from its DMF solution. The structural and thermal properties of terpolymers and electrospun poly(Zonyl-TM-MMA-BA) nanofibers were analyzed using Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and differential scanning calorimetry. Nanofiber morphology was investigated by scanning electron microscopy. Electrospun nanofiber layer was found to be superhydrophobic with a water contact angle of 172 {+-} 1 Degree-Sign and highly oleophobic with hexadecane, glycerol and ethylene glycol contact angles of 70 {+-} 1 Degree-Sign , 167 {+-} 1 Degree-Sign and 163 {+-} 1 Degree-Sign respectively. The change of the contact angle results on the electrospun fiber layer and flat terpolymer surfaces by varying feed monomer composition were compared and discussed in the text.

  12. Trilayered Morphology of an ABC Triple Crystalline Triblock Terpolymer

    KAUST Repository

    Palacios, Jordana K.

    2017-09-07

    Triple crystalline triblock terpolymers are materials with remarkable semicrystalline superstructures. In this work, we report for first time the alternating triple lamellar morphology that self-assembles inside spherulites of a triblock terpolymer composed of poly(ethylene oxide) (PEO), poly(ε-caprolactone) (PCL), and poly(l-lactide) (PLLA). The morphology of the PEO-b-PCL-b-PLLA triblock terpolymer is compared to an analogous PCL-b-PLLA diblock copolymer. Both diblock and triblock form a single phase in the melt. Two crystallization protocols were employed to create particular crystalline morphologies. In both cases, the isothermal crystallization of the PLA block is induced first (at 81 °C, a temperature above the melting points of both PCL and PEO blocks) and PLLA spherulites form a template, whereupon cooling the other two blocks can crystallize within the PLLA interlamellar spaces. WAXS analysis demonstrated the double crystalline and triple crystalline nature of the materials. The lamellar structure was evaluated by AFM observations and SAXS measurements. Moreover, theoretical SAXS curves of one-dimensional structural models were calculated. AFM micrographs of the triblock terpolymer evidenced the three different lamellae of PLLA, PCL and PEO that coexist together within the same spherulite. Three different lamellar thickness were determined, and their dimensions suggested that all blocks crystallized in chain-folded conformations. The evolution of the triple lamellar morphology during heating of tricrystalline samples was followed by in situ synchrotron SAXS measurements. The theoretical analysis of the SAXS curves of the triblock terpolymer allowed us to propose a stacking morphological model, in which a particular trilayer structure exists, where one lamella of PCL or one lamella of PEO is inserted randomly between two adjacent PLLA lamellae.

  13. Compatibilization of acrylonitrile-butadiene-styrene terpolymer/poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) blend: effect on morphology, interface, mechanical properties and hydrophilicity

    Science.gov (United States)

    Chen, Tingting; Zhang, Jun

    2018-04-01

    The compatibilization of acrylonitrile-butadiene-styrene terpolymer (ABS) and poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) (PETG) blends was first investigated. Styrene-acrylonitrile-glycidyl methacrylate terpolymer (SAG) and ABS grafted with maleic anhydride (ABS-g-MAH) were selected as reactive compatibilizers for the ABS/PETG blends. The compatibilization effect was assessed by scanning electron microscope (SEM), differential scanning calorimetry (DSC) and mechanical properties. And the effect of compatibilizers on the hydrophilicity of the blends was evaluated as well. SEM observation and DSC analysis confirmed that both SAG and ABS-g-MAH compatibilizers could improve the compatibility between ABS and PETG, leading to an improvement in toughness of the blend. The possible cause for the improvement of compatibility was the reaction between compatibilizers and PETG, which could in situ turn out compatibilizers that acted as interfacial agents to enhance the interfacial interaction in the blend. Especially, the addition of SAG significantly decreased the dispersion phase size and the interface voids almost disappeared. Since the in situ reactions between the epoxy groups of SAG and the end groups (sbnd COOH or sbnd OH) of PETG generated PETG-co-SAG copolymer at the blend interface, and the cross-linking reactions proposed to take place between SAG and the PETG-co-SAG copolymer, acting as compatibilizer, could significantly increase the interfacial interaction. The addition of SAG also enhanced the stiffness of the blends. Moreover, the addition of SAG made the blend more hydrophilic, whereas the addition of ABS-g-MAH made the blend more hydrophobic. Therefore, SAG was a good compatibilizer for the ABS/PETG blends and could simultaneously provide the blends with toughening, stiffening and hydrophilic effects.

  14. Microstructure study of ethylene, propylene and 1-decene terpolymers by 13C-NMR

    International Nuclear Information System (INIS)

    Ferreira, Marcio; Escher, Fernanda Nunes; Galland, Griselda Barrera

    2001-01-01

    Terpolymers of ethylene-propylene-1-decene with different composition of monomers were obtained using the metallocenes catalyst rac-EtInd 2 ZrCl 2 . The complete 13 C-NMR characterization of these terpolymers was done qualitatively and quantitatively. Chemical shifts, carbon assignments and corresponding integrals for each triad sequence are presented. (author)

  15. Studies Of Urea Geometry By Means Of Ab Initio Methods And Computer Simulations Of Liquids [estudo Da Geometria Da Uréia Por Métodos Ab Initio E Simulaição Computacional De Líquidos

    OpenAIRE

    Cirino J.J.V.; Bertran C.A.

    2002-01-01

    A study was carried out on the urea geometries using ab initio calculation and Monte Carlo computational simulation of liquids. The ab initio calculated results showed that urea has a non-planar conformation in the gas phase in which the hydrogen atoms are out of the plane formed by the heavy atoms. Free energies associated to the rotation of the amino groups of urea in water were obtained using the Monte Carlo method in which the thermodynamic perturbation theory is implemented. The magnitud...

  16. Synthesis and thermal studies of acrylonitrile terpolymers as carbon fiber precursor

    International Nuclear Information System (INIS)

    Hakeem, W.A.; Rusli Daik; Ahmad, I.

    2010-01-01

    Acrylonitrile (AN) and 2-dimethylaminoethyl methacrylate (DMAEM) terpolymers with fumaronitrile (FN) or itaconic acid (IA) as the termonomer have been synthesized. The solvent-water suspension polymerization was carried out at 65 degree Celsius, using α, α-azobisisobutyronitrile (AIBN) as the initiator in a mixture of dimethylformamide (DMF) and deionized water. Composition of AN and DMAEM was fixed at 98:2 in all the terpolymers, while the amount of FN and IA was carried out on the terpolymers by means of Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). The glass transition temperature (T g ), initial temperature of cyclization (T i ), heat evolved (ΔH), and the char yield of the terpolymers are compared with that of the copolymer of AN and DMAEM. (author)

  17. Estudo da geometria da uréia por métodos ab initio e simulação computacional de líquidos

    Directory of Open Access Journals (Sweden)

    Cirino José Jair Vianna

    2002-01-01

    Full Text Available A study was carried out on the urea geometries using ab initio calculation and Monte Carlo computational simulation of liquids. The ab initio calculated results showed that urea has a non-planar conformation in the gas phase in which the hydrogen atoms are out of the plane formed by the heavy atoms. Free energies associated to the rotation of the amino groups of urea in water were obtained using the Monte Carlo method in which the thermodynamic perturbation theory is implemented. The magnitude of the free energy obtained from this simulation did not permit us to conclude that urea is non-planar in water.

  18. Estudo da geometria da uréia por métodos ab initio e simulação computacional de líquidos

    OpenAIRE

    Cirino,José Jair Vianna; Bertran,Celso Aparecido

    2002-01-01

    A study was carried out on the urea geometries using ab initio calculation and Monte Carlo computational simulation of liquids. The ab initio calculated results showed that urea has a non-planar conformation in the gas phase in which the hydrogen atoms are out of the plane formed by the heavy atoms. Free energies associated to the rotation of the amino groups of urea in water were obtained using the Monte Carlo method in which the thermodynamic perturbation theory is implemented. The magnitud...

  19. Sulfonation of vulcanized ethylene-propylene-diene terpolymer membranes

    International Nuclear Information System (INIS)

    Barroso-Bujans, F.; Verdejo, R.; Lozano, A.; Fierro, J.L.G.; Lopez-Manchado, M.A.

    2008-01-01

    In the present work, sulfonation of previously vulcanized ethylene propylene diene terpolymer (EPDM) membranes was developed in a swelling solvent with acetyl sulfate. This procedure avoids the need to pre-dissolve the raw polymer. The reaction conditions were optimized in terms of solvent type, reaction time, acetyl sulfate concentration and film thickness to obtain the maximum degree of sulfonation of the polymer. The sulfonation procedure presented in this study yields a degree of sulfonation comparable to the chlorosulfonic acid procedure. Sulfonic acid groups were detected by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy, and quantified by titrations. Proton conductivity and water uptake were measured by means of impedance spectroscopy and swelling measurements, respectively, and were correlated with the degree of sulfonation. Tensile strength and Young's modulus of sulfonated EPDM increased with the degree of sulfonation, while elongation at break remained constant. Thermal stability of the sulfonated EPDM was studied by simultaneous thermogravimetry-mass spectroscopy

  20. Radiochemical oxidation of an ethylene-propylene-hexadiene terpolymer

    International Nuclear Information System (INIS)

    Verdu, J.; Pinel, B.; Gueguen, V.; Audouin, L.

    1996-01-01

    The γ ray initiated oxidation of an ethylene-propylene-hexadiene terpolymer (molar ratios 87/12/1) was studied by IR spectrophotometry in the 40-90 deg C temperature range, with dose rates varying from 10 to 2500 Gy h -1 and integrated doses up to 100 kGy. Bulk (∼ 8 mm) and thin (∼ 0.1 mm) samples were studied. It appears that the oxidation is diffusion controlled in the bulk samples and non diffusion controlled in thin films. A kinetic study of IR spectral changes in these latter reveals that vinylene groups of the hexadiene monomer unit disappear in the early period of exposure, presumably by addition reactions with peroxy radicals. A very simplified mechanistic scheme allows a satisfying modelling of this process whose rate is almost proportional to the dose rate (irradiation intensity). (authors)

  1. Chemical modification of glass surface with a monolayer of nonchromophoric and chromophoric methacrylate terpolymer

    Energy Technology Data Exchange (ETDEWEB)

    Janik, Ryszard [Department of Polymer Engineering and Technology, Wroclaw University of Technology, 50-370 Wroclaw (Poland); Kucharski, Stanislaw, E-mail: stanislaw.kucharski@pwr.wroc.pl [Department of Polymer Engineering and Technology, Wroclaw University of Technology, 50-370 Wroclaw (Poland); Sobolewska, Anna [Institute of Physical and Theoretical Chemistry, Wroclaw University of Technology, 50-370 Wroclaw (Poland); Barille, Regis [Institut des Sciences et Techniques Moleculaires d' Angers ' Moltech Anjou' , CNRS UMR 6200, 49045 Angers (France)

    2010-11-15

    The methacrylate terpolymers, a nonchromophoric and chromophoric one, containing 2-hydroxyethyl groups were reacted with 3-isocyanatopropyltriethoxysilane to obtain reactive polymers able to form covalent bonding with -SiOH groups of the glass surface via triethoxysilane group condensation. Chemical modification of the Corning 2949 glass plates treated in this way resulted in increase of wetting angle from 11{sup o} to ca. 70-73{sup o}. Determination of ellipsometric parameters revealed low value of the substrate refractive index as compared with that of bulk Corning 2949 glass suggesting roughness of the surface. The AFM image of the bare glass surface and that modified with terpolymer monolayer confirmed this phenomenon. Modification of the glass with the terpolymer monolayer made it possible to create the substrate surface well suited for deposition of familiar chromophore film by spin-coating. The chromophore polymer film deposited onto the modified glass surface was found to be resistant to come unstuck in aqueous solution.

  2. Sequential crystallization and morphology of triple crystalline biodegradable PEO-b-PCL-b-PLLA triblock terpolymers

    KAUST Repository

    Palacios, Jordana

    2016-01-05

    The sequential crystallization of poly(ethylene oxide)-b-poly(e-caprolactone)-b-poly(L-lactide) (PEO-b-PCL-b-PLLA) triblock terpolymers, in which the three blocks are able to crystallize separately and sequentially from the melt, is presented. Two terpolymers with identical PEO and PCL block lengths and two different PLLA block lengths were prepared, thus the effect of increasing PLLA content on the crystallization behavior and morphology was evaluated. Wide angle X-Ray scattering (WAXS) experiments performed on cooling from the melt confirmed the triple crystalline nature of these terpolymers and revealed that they crystallize in sequence: the PLLA block crystallizes first, then the PCL block, and finally the PEO block. Differential scanning calorimetry (DSC) analysis further demonstrated that the three blocks can crystallize from the melt when a low cooling rate is employed. The crystallization process takes place from a homogenous melt as indicated by small angle X-Ray scattering (SAXS) experiments. The crystallization and melting enthalpies and temperatures of both PEO and PCL blocks decrease as PLLA content in the terpolymer increases. Polarized light optical microscopy (PLOM) demonstrated that the PLLA block templates the morphology of the terpolymer, as it forms spherulites upon cooling from the melt. The subsequent crystallization of PCL and PEO blocks occurs inside the interlamellar regions of the previously formed PLLA block spherulites. In this way, unique triple crystalline mixed spherulitic superstructures have been observed for the first time. As the PLLA content in the terpolymer is reduced the superstructural morphology changes from spherulites to a more axialitic-like structure.

  3. PVDF-based copolymers, terpolymers and their multi-component material systems for capacitor applications

    Science.gov (United States)

    Chu, Baojin

    Miniature of power electronics, scaling-down of microelectronics and other electrical and electronic systems, and development of many technologies (such as hybrid vehicles or implantable heart defibrillators) require capacitors with high energy density to improve the weight and volume efficiency of the whole system. Various capacitor technologies are investigated to meet the requirements of developing future technologies. Among these technologies, polymer film capacitor technology is one of the most promising. Besides high energy density, polymer-based capacitors possess the merits of high power density, low loss, high reliability (self-healing), easy processing, and feasibility (in size, shape and energy level). Due to the ferroelectricity of polyvinylidene fluoride (PVDF)-based polymers, they exhibit much higher polarization response under an electric field, in comparison with other linear dielectric polymers for capacitor applications. The maximum polarization level of PVDF-based polymers can be as high as 0.1 C/m2 and the breakdown field can be higher than 600 MV/m. An estimated energy density of around 30 J/cm3 can be expected in this class of materials. However, this value is much higher than the energy density that can be achieved in the PVDF homopolymer and the poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) copolymers due to the polarization hysteresis in these polymers. Therefore, in this thesis, PVDF-based polymer materials were investigated and developed to approach this expected energy density by various strategies. An energy density of higher than 24 J/cm 3, which is close to the predicted value, was found in PVDF-based copolymers. Recently, the poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) terpolymer was developed in Prof. Qiming Zhang's group. Previous works have shown that incorporation of CTE into P(VDF-TrFE) copolymers, in which bulky CFE acts as a defect, could convert the copolymer into relaxor

  4. Surface hydrophilic modification of acrylonitrile-butadiene-styrene terpolymer by poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate): Preparation, characterization, and properties studies

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Tingting; Zhang, Jun, E-mail: zhangjun@njtech.edu.cn

    2016-12-01

    Highlights: • Surface hydrophilic modified ABS was prepared by melt blending with PETG. • O= C−O groups were enriched on the surface with increasing PETG content. • Hydrophilic property of the blends was enhanced with increasing PETG content. • Phase inversion behavior of the blends occurred around intermediate composition. • Tensile and flexural strength were enhanced with increasing PETG content. - Abstract: Surface hydrophilic modified acrylonitrile-butadiene-styrene (ABS) terpolymer was prepared by melt blending with poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) (PETG) random copolymer as the modifier. Attenuated total reflectance-Fourier transform-infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) were used for surface analysis. Through the contact angle measurement, the relationship between surface properties of the ABS/PETG blends and PETG content was investigated. Scanning electron microscope (SEM) and dynamical mechanical thermal analysis (DMTA) were used to characterize interface morphology and compatibility of the blends. The effect of PETG content on the mechanical and rheological properties was examined. The ATR-FTIR and XPS analysis suggested that the hydrophilic groups were enriched on the surface with increasing PETG content in the blend. The decrease of the water contact angle and the increase of the polarity for the blends with increasing PETG content indicated that the hydrophilic property of the blends was enhanced with increasing PETG content. The ABS/PETG blends were partially miscible. And the blends with ≤50 wt% PETG had better compatibility than the blends with above 50 wt% PETG. It was clear that below 50 wt% PETG, the PETG phase was dispersed in spherical form and the ABS phase was continuous. Above 50 wt% PETG, the PETG phase became continuous and the ABS phase was dispersed in irregular form. Moreover, the tensile strength and flexural strength of the blends were enhanced with

  5. Synthesis and Self-Assembly of Amphiphilic Triblock Terpolymers with Complex Macromolecular Architecture

    KAUST Repository

    Polymeropoulos, George; Zapsas, George; Hadjichristidis, Nikolaos; Avgeropoulos, Apostolos

    2015-01-01

    Two star triblock terpolymers (PS-b-P2VP-b-PEO)3 and one dendritic-like terpolymer [PS-b-P2VP-b-(PEO)2]3 of PS (polystyrene), P2VP (poly(2-vinylpyridine)), and PEO (poly(ethylene oxide)), never reported before, were synthesized by combining atom transfer radical and anionic polymerizations. The synthesis involves the transformation of the -Br groups of the previously reported Br-terminated 3-arm star diblock copolymers to one or two -OH groups, followed by anionic polymerization of ethylene oxide to afford the star or dendritic structure, respectively. The well-defined structure of the terpolymers was confirmed by static light scattering, size exclusion chromatography, and NMR spectroscopy. The self-assembly in solution and the morphology in bulk of the terpolymers, studied by dynamic light scattering and transmission electron microscopy, respectively, reveal new insights in the phase separation of these materials with complex macromolecular architecture. © 2015 American Chemical Society.

  6. Thermoanalytical Study and Kinetics of New 8-Hydroxyquinoline 5-sulphonic Acid-Oxamide-Formaldehyde Terpolymer Resins

    Directory of Open Access Journals (Sweden)

    Rajesh N. Singru

    2009-01-01

    Full Text Available The terpolymer resins (8-HQ5-SAOF have been synthesized by the condensation of 8-hydroxyquinoline 5-sulphonic acid (8-HQ5-SA and oxamide (O with formaldehyde (F in the presence of acid catalyst and using varied molar proportion of the reacting monomers. The synthesized terpolymer resins have been characterized by different physico-chemical techniques. Thermogravimetric analysis of all terpolymer resins in present study have been carried out by non-isothermal thermogravimetric analysis technique in which sample is subjected to condition of continuous increase in temperature at linear rate. Thermal study of the resins was carried out to determine their mode of decomposition and relative thermal stabilities. Thermal decomposition curves were studied carefully with minute details. The Freeman-Carroll and Sharp-Wentworth methods have been used in the present investigation to calculate thermal activation energy and different kinetic parameter of the terpolymer resins. Thermal activation energy (Ea calculated with above two mentioned methods are in close agreement. The advantage of Freeman-Carroll method is to calculate both the order of reaction (n and energy of activation in one single stage by keeping heating rate constant. By using data of thermogravimetric analysis, various thermodynamic parameters like frequency factor (Z, entropy change (Δ S, free energy change (Δ F and apparent entropy (S* have been determined using Freeman-Carroll method.

  7. Morphologies of ABC triblock terpolymer melts containing poly(Cyclohexadiene): Effects of conformational asymmetry

    KAUST Repository

    Kumar, Rajeev Senthil

    2013-02-12

    We have synthesized linear ABC triblock terpolymers containing poly(1,3-cyclohexadiene), PCHD, as an end block and characterized their morphologies in the melt. Specifically, we have studied terpolymers containing polystyrene (PS), polybutadiene (PB), and polyisoprene (PI) as the other blocks. Systematically varying the ratio of 1,2- /1,4-microstructures of poly(1,3-cyclohexadiene), we have studied the effects of conformational asymmetry among the three blocks on the morphologies using transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), and self-consistent field theory (SCFT) performed with PolySwift++. Our work reveals that the triblock terpolymer melts containing a high percentage of 1,2-microstructures in the PCHD block are disordered at 110 C for all the samples, independent of sequence and volume fraction of the blocks. In contrast, the triblock terpolymer melts containing a high percentage of 1,4-microstructure form regular morphologies known from the literature. The accuracy of the SCFT calculations depends on calculating the χ parameters that quantify the repulsive interactions between different monomers. Simulations using χ values obtained from solubility parameters and group contribution methods are unable to reproduce the morphologies as seen in the experiments. However, SCFT calculations accounting for the enhancement of the χ parameter with an increase in the conformational asymmetry lead to an excellent agreement between theory and experiments. These results highlight the importance of conformational asymmetry in tuning the χ parameter and, in turn, morphologies in block copolymers. © 2012 American Chemical Society.

  8. Sequential crystallization and morphology of triple crystalline biodegradable PEO-b-PCL-b-PLLA triblock terpolymers

    KAUST Repository

    Palacios, Jordana; Mugica, Agurtzane; Zubitur, Manuela; Iturrospe, Amaia; Arbe, A.; Liu, Guoming; Wang, Dujin; Zhao, Junpeng; Hadjichristidis, Nikolaos; Muller, Alejandro

    2016-01-01

    The sequential crystallization of poly(ethylene oxide)-b-poly(e-caprolactone)-b-poly(L-lactide) (PEO-b-PCL-b-PLLA) triblock terpolymers, in which the three blocks are able to crystallize separately and sequentially from the melt, is presented. Two

  9. Combining covalent and noncovalent cross-linking: a novel terpolymer for two-step curing applications

    NARCIS (Netherlands)

    El-Ghayoury, A.; Hofmeier, H.; Ruiter, de B.; Schubert, U.S.

    2003-01-01

    A terpolymer of poly(butyl acrylate) bearing terpyridine as well as oxetane units was synthesized by free radical polymerization and characterized using NMR, UV-vis, and GPC. Subsequently, UV-vis experiments indicated clearly a noncovalent cross-linking of the terpyridine moieties by addition of

  10. Synthesis and Self-Assembly of Amphiphilic Triblock Terpolymers with Complex Macromolecular Architecture

    KAUST Repository

    Polymeropoulos, George

    2015-11-25

    Two star triblock terpolymers (PS-b-P2VP-b-PEO)3 and one dendritic-like terpolymer [PS-b-P2VP-b-(PEO)2]3 of PS (polystyrene), P2VP (poly(2-vinylpyridine)), and PEO (poly(ethylene oxide)), never reported before, were synthesized by combining atom transfer radical and anionic polymerizations. The synthesis involves the transformation of the -Br groups of the previously reported Br-terminated 3-arm star diblock copolymers to one or two -OH groups, followed by anionic polymerization of ethylene oxide to afford the star or dendritic structure, respectively. The well-defined structure of the terpolymers was confirmed by static light scattering, size exclusion chromatography, and NMR spectroscopy. The self-assembly in solution and the morphology in bulk of the terpolymers, studied by dynamic light scattering and transmission electron microscopy, respectively, reveal new insights in the phase separation of these materials with complex macromolecular architecture. © 2015 American Chemical Society.

  11. Well-defined Polymethylene-Based Co/Terpolymers by Combining Anthracene/Maleimide Diels-Alder Reaction with Polyhomologation

    KAUST Repository

    Hadjichristidis, Nikolaos; Alkayal, Nazeeha

    2015-01-01

    A novel strategy towards well-defined polymethylene-based co/terpolymers, by combining anthracene/maleimide Diels-Alder reaction with polyhomologation, is presented. For the synthesis of diblock copolymers the following approach was applied: a

  12. Formation of integral asymmetric membranes of AB diblock and ABC triblock copolymers by phase inversion.

    Science.gov (United States)

    Jung, Adina; Filiz, Volkan; Rangou, Sofia; Buhr, Kristian; Merten, Petra; Hahn, Janina; Clodt, Juliana; Abetz, Clarissa; Abetz, Volker

    2013-04-12

    The formation of integral asymmetric membranes from ABC triblock terpolymers by non-solvent-induced phase separation is shown. They are compared with the AB diblock copolymer precursors. Triblock terpolymers of polystyrene-block-poly(2-vinylpyridine)-block-poly(ethylene oxide) (PS-b-P2VP-b-PEO) with two compositions are investigated. The third block supports the formation of a membrane in a case, where the corresponding diblock copolymer does not form a good membrane. In addition, the hydrophilicity is increased by the third block and due to the hydroxyl group the possibility of post-functionalization is given. The morphologies are imaged by scanning electron microscopy. The influence of the PEO on the membrane properties is analyzed by water flux, retention, and dynamic contact angle measurements. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Ion Exchange Properties of a Terpolymer Resin Derived from 2, 4-Dihydroxybenzaldehyde, Oxamide and Formaldehyde

    Directory of Open Access Journals (Sweden)

    M. V. Tarase

    2009-01-01

    Full Text Available Terpolymer resins (2,4-DHBOF were synthesized by the condensation of 2,4-dihydroxybenzaldehyde and oxamide with formaldehyde in the presence of hydrochloric acid as catalyst, proved to be selective chelation ion exchange terpolymer resins for certain metals. Chelation ion exchange properties of these polymers were studied for Fe+3, Cu+2, Hg+2, Cd+2, Co+2, Zn+2, Ni+2 and Pb+2 ions. A batch equilibrium method was employed in the study of the selectivity of the distribution of a given metal ions between the polymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in a media of various ionic strengths. The polymer showed a higher selectivity for Fe+3, Cd+2 and Co+2 ions than for Cu+2, Hg+2, Zn+2, Ni+2 and Pb+2 ions.

  14. A Comprehensive Systematic Study on Thermoresponsive Gels: Beyond the Common Architectures of Linear Terpolymers

    Directory of Open Access Journals (Sweden)

    Anna P. Constantinou

    2017-01-01

    Full Text Available In this study, seven thermoresponsive methacrylate terpolymers with the same molar mass (MM and composition but various architectures were successfully synthesized using group transfer polymerization (GTP. These terpolymers were based on tri(ethylene glycol methyl ether methacrylate (TEGMA, A unit, n-butyl methacrylate (BuMA, B unit, and 2-(dimethylaminoethyl methacrylate (DMAEMA, C unit. Along with the more common ABC, ACB, BAC, and statistical architectures, three diblock terpolymers were also synthesized and investigated for the first time, namely (ABC, A(BC, and B(AC; where the units in the brackets are randomly copolymerized. Two BC diblock copolymers were also synthesized for comparison. Their hydrodynamic diameters and their effective pKas were determined by dynamic light scattering (DLS and hydrogen ion titrations, respectively. The self-assembly behavior of the copolymers was also visualized by transmission electron microscopy (TEM. Both dilute and concentrated aqueous copolymer solutions were extensively studied by visual tests and their cloud points (CP and gel points were determined. It is proven that the aqueous solution properties of the copolymers, with specific interest in their thermoresponsive properties, are influenced by the architecture, with the ABC and A(BC ones to show clear sol-gel transition.

  15. Synthesis and characterisation of sulphonated poly(arylene sulphone) terpolymers with triphenylphosphine oxide moieties for proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Titvinidze, G.; Kaltbeitzel, A.; Manhart, A.; Meyer, W.H. [Max Planck Institute for Polymer Research, Mainz (Germany)

    2010-06-15

    For application in fuel cells, a series of sulphonated poly(phenylene sulphone) terpolymers with triphenylphosphine oxide moieties as constitutional units in the polymer backbone have been prepared. The synthesis of the terpolymers represents a two-step process including: (i) an aromatic nucleophilic substitution polycondensation of three difluoro monomers with varying ratios, i.e. 3,3'-disulphonate-4,4'-difluorodiphenylsulphone, 4,4'-difluorodiphenylsulphone and bis(4-fluorophenyl)phenyl phosphine oxide (BFPPO), with 4,4'-thiobisbenzenethiol yielding sulphonated poly(phenylene sulphide) terpolymers (sPPSPO) and (ii) their following oxidation with hydrogen peroxide in acidic solution to yield sulphonated poly(phenylene sulphone) terpolymers (sPPSO2PO). The structures and molecular compositions were confirmed by {sup 1}H and {sup 13}C NMR spectroscopy. The ion exchange capacity (IEC) was adjusted at will choosing the appropriate ratio of sulphonated and unsulphonated monomers. Terpolymers with 1.72 {<=} IEC {<=} 2.32 have been obtained. Sulphonated poly(arylene) ionomers containing only sulphone (-SO{sub 2}-) linkages and phosphine oxide (-PO-) units rather than ether or sulphide in the backbone reveal a high thermal and oxidative stability. Membranes were cast either from dimethylformamide (DMF) or from dimethyl sulphoxide (DMSO) solutions. For all terpolymers some general characteristic trends were observed, such as an increase of the proton conductivity with increasing IEC, water uptake and temperature. The series of sPPSO2PO membranes offered high conductivities at high humidification, however, their performance strongly depends on the relative humidity. The mechanical properties of sulphonated poly(phenylene sulphone)s have been considerably improved by means of terpolymerisation with phenylene oxide moieties. Even under high humidification the terpolymers form clear, flexible membranes the stress at break of some membranes exceeds that of

  16. Estudo da tenacidade à fratura por meio do método do trabalho essencial de fratura (EWF) da blenda PBT/ABS, reforçada com fibra de vidro

    OpenAIRE

    Carlos do Amaral Razzino

    2008-01-01

    O terpolímero acrilonitrila-butadieno-estireno (ABS) com alto teor de borracha tem sido utilizado para tenacificar PBT. Como resultados, são obtidas blendas de PBT/ABS super tenazes sob impacto Izod entalhado. No entanto, ocorre uma redução significativa no módulo elástico. O desenvolvimento de um balanço de rigidez-tenacidade em blendas de PBT/ABS pode ser alcançado pela adição de fibras curtas de vidro. O desempenho dos compósitos é fortemente dependente da interface matriz-fibra e conseque...

  17. Synthesis and characterization of a push-pull terpolymer based on anthracene, fluorene and benzothiadiazole

    Energy Technology Data Exchange (ETDEWEB)

    Floriano, Ana Carolina; Silveira, Daiana Santos; Cristovan, Fernando Henrique, E-mail: carolina.floriano@unifesp.br [Universidade Federal de Sao Paulo (UNIFESP), Sao Jose dos Campos, SP (Brazil); Rosa, Gabriel Marques; Liao, Luciano Morais [Universidade Federal de Goias (UFG), Goiania, GO (Brazil); Piovessan, Erick [Universidade Federal de Uberlandia (UFU), MG (Brazil)

    2016-07-01

    Full text: The development of organic optoelectronic devices with higher efficiency required new forms of polymers with strong donor-acceptor character (D-A), called a push-pull polymers. Most studies of organic polymers used in optoelectronic applications are centered on poly(3-hexylthiophene) with high regioregularity. However, there are other polymers synthesized with monomers that enables the possibility to adapt its electrical and optical properties. Polyfluorene derivatives show interesting chemical and physical properties due to a rigid planar biphenyl unit that are easily substituted at the remote C-9 position, improving the its processability in relation to polyfluorene, so it can be can be processed by spin-coating and many others deposition techniques. Fluorene derivatives copolymers prepared with anthracene unit improve electrochemical properties and present good photo and electroluminescence properties, due to an enhancement of the system conjugation. The benzothiadiazole, known by their environmental stability, planarity and electron-withdrawing nature, are a promising molecule in push−pull type semiconducting polymers. In this study proceed with the terpolymer synthesis containing 9,9-Dihexylfluorene and anthracene as pushing unit and benzothiadiazole as pushing unit. Also we synthesized the poly(9,9-dihexylfluorene)-co-(anthracene) and poly(9,9- dihexylfluorene)-co-(benzothiadiazole) copolymers. The polymers were synthesized using Suzuki coupling and characterized by FT-IR spectroscopy that shows the characteristic monomer bands and the polymer formation were confirmed by {sup 1}H-NMR. Polymerization yield of three polymers were about 50-70%. Polymers present good solubility in common organic solvent such as chloroform. Terpolymer UV-Vis spectra revealed broadband absorbance from 300 to 680nm and absorption maximum at 441 nm. Finally, the preliminary results indicate that the push-pull terpolymer is a promising broadband absorbing polymer for

  18. Synthesis and characterization of a push-pull terpolymer based on anthracene, fluorene and benzothiadiazole

    International Nuclear Information System (INIS)

    Floriano, Ana Carolina; Silveira, Daiana Santos; Cristovan, Fernando Henrique; Rosa, Gabriel Marques; Liao, Luciano Morais; Piovessan, Erick

    2016-01-01

    Full text: The development of organic optoelectronic devices with higher efficiency required new forms of polymers with strong donor-acceptor character (D-A), called a push-pull polymers. Most studies of organic polymers used in optoelectronic applications are centered on poly(3-hexylthiophene) with high regioregularity. However, there are other polymers synthesized with monomers that enables the possibility to adapt its electrical and optical properties. Polyfluorene derivatives show interesting chemical and physical properties due to a rigid planar biphenyl unit that are easily substituted at the remote C-9 position, improving the its processability in relation to polyfluorene, so it can be can be processed by spin-coating and many others deposition techniques. Fluorene derivatives copolymers prepared with anthracene unit improve electrochemical properties and present good photo and electroluminescence properties, due to an enhancement of the system conjugation. The benzothiadiazole, known by their environmental stability, planarity and electron-withdrawing nature, are a promising molecule in push−pull type semiconducting polymers. In this study proceed with the terpolymer synthesis containing 9,9-Dihexylfluorene and anthracene as pushing unit and benzothiadiazole as pushing unit. Also we synthesized the poly(9,9-dihexylfluorene)-co-(anthracene) and poly(9,9- dihexylfluorene)-co-(benzothiadiazole) copolymers. The polymers were synthesized using Suzuki coupling and characterized by FT-IR spectroscopy that shows the characteristic monomer bands and the polymer formation were confirmed by 1 H-NMR. Polymerization yield of three polymers were about 50-70%. Polymers present good solubility in common organic solvent such as chloroform. Terpolymer UV-Vis spectra revealed broadband absorbance from 300 to 680nm and absorption maximum at 441 nm. Finally, the preliminary results indicate that the push-pull terpolymer is a promising broadband absorbing polymer for

  19. Redox polymerization of acrylonitrile-methyl acrylate-fumaronitrile terpolymer as precursor for carbon fiber

    International Nuclear Information System (INIS)

    Jamil, S.N.A.M.; Rusli Daik; Ahmad, I.

    2010-01-01

    Synthesis of acrylonitrile (AN) with methyl acrylate and fumaronitrile as comonomer and termonomer respectively, were carried out by redox polymerization using sodium bisulfite (SBS) and potassium persulphate (KPS) as initiator at 40 degree Celsius. The effect of methyl acrylate (MA) and fumaronitrile (FN) on the glass transition temperature (T g ) and stabilization temperature has been studied by Differential Scanning Calorimetry (DSC). The degradation behavior and char yield were obtained by Thermogravimetric Analysis. The T g of poly (AN/ MA) copolymers were found to be lower (∼70 degree Celsius) as compared with polyacrylonitrile (PAN) (210 degree Celsius). However, by incorporating MA into PAN system, the char yield reduced significantly. It was found that FN reduced the initial cyclization temperature of poly (AN/ MA/ FN) terpolymer to ∼230 degree Celsius as compared with poly(AN/ MA) copolymer (∼260 degree Celsius). In addition, FN reduced the heat liberation per unit time during the stabilization process that consequently reduced the emission of volatile group during this process. Thereby, the char yield of poly(AN/ MA/ FN) 90/ 4/ 6 terpolymer is higher at 51 % as compared with poly(AN/ MA) 90/ 10 copolymer (45 %). (author)

  20. Core-Shell Double Gyroid Structure Formed by Linear ABC Terpolymer Thin Films.

    Science.gov (United States)

    Antoine, Ségolène; Aissou, Karim; Mumtaz, Muhammad; Telitel, Siham; Pécastaings, Gilles; Wirotius, Anne-Laure; Brochon, Cyril; Cloutet, Eric; Fleury, Guillaume; Hadziioannou, Georges

    2018-05-01

    The synthesis and self-assembly in thin-film configuration of linear ABC triblock terpolymer chains consisting of polystyrene (PS), poly(2-vinylpyridine) (P2VP), and polyisoprene (PI) are described. For that purpose, a hydroxyl-terminated PS-b-P2VP (45 kg mol -1 ) building block and a carboxyl-terminated PI (9 kg mol -1 ) are first separately prepared by anionic polymerization, and then are coupled via a Steglich esterification reaction. This quantitative and metal-free catalyst synthesis route reveals to be very interesting since functionalization and purification steps are straightforward, and well-defined terpolymers are produced. A solvent vapor annealing (SVA) process is used to promote the self-assembly of frustrated PS-b-P2VP-b-PI chains into a thin-film core-shell double gyroid (Q 230 , space group: Ia3¯d) structure. As terraces are formed within PS-b-P2VP-b-PI thin films during the SVA process under a CHCl 3 vapor, different plane orientations of the Q 230 structure ((211), (110), (111), and (100)) are observed at the polymer-air interface depending on the film thickness. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Tuning Structure and Properties of Graded Triblock Terpolymer-Based Mesoporous and Hybrid Films

    KAUST Repository

    Phillip, William A.

    2011-07-13

    Despite considerable efforts toward fabricating ordered, water-permeable, mesoporous films from block copolymers, fine control over pore dimensions, structural characteristics, and mechanical behavior of graded structures remains a major challenge. To this end, we describe the fabrication and performance characteristics of graded mesoporous and hybrid films derived from the newly synthesized triblock terpolymer, poly(isoprene-b-styrene-b-4-vinylpyridine). A unique morphology, unachievable in diblock copolymer systems, with enhanced mechanical integrity is evidenced. The film structure comprises a thin selective layer containing vertically aligned and nearly monodisperse mesopores at a density of more than 1014 per m2 above a graded macroporous layer. Hybridization via homopolymer blending enables tuning of pore size within the range of 16 to 30 nm. Solvent flow and solute separation experiments demonstrate that the terpolymer films have permeabilities comparable to commercial membranes, are stimuli-responsive, and contain pores with a nearly monodisperse diameter. These results suggest that moving to multiblock polymers and their hybrids may open new paths to produce high-performance graded membranes for filtration, separations, nanofluidics, catalysis, and drug delivery. © 2011 American Chemical Society.

  2. Chelation Ion Exchange Properties of 2, 4-Dihydroxyacetophenone-Biuret-Formaldehyde Terpolymer Resin

    Directory of Open Access Journals (Sweden)

    Sanjiokumar S. Rahangdale

    2009-01-01

    Full Text Available The terpolymer resin 2, 4-HABF has been synthesized by the condensation of 2, 4-dihydroxyacetophenone (2, 4-HA and biuret (B with formaldehyde (F in 1:1:2 molar ratios in presence of 2 M hydrochloric acid as catalyst. UV-Visible, IR and proton NMR spectral studies have been carried out to elucidate the structure of the resin. A terpolymer (2, 4-HABF proved to be a selective chelating ion exchange polymer for certain metals. Chelating ion-exchange properties of this polymer were studied for Fe3+, Cu2+, Ni2+, Co2+, Zn2+, Cd2+ and Pb2+ ions. A batch equilibrium method was employed in the study of the selectivity of metal ion uptake involving the measurement of the distribution of a given metal ion between the polymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in media of various ionic strengths. The polymer showed highest selectivity for Fe3+, Cu2+ ions than for Ni2+, Co2+, Zn2+, Cd2+, and Pb2+ ions. Study of distribution ratio as a formation of pH indicates that the amount of metal ion taken by resin is increases with the increasing pH of the medium.

  3. A Novel Terpolymer as Fluid Loss Additive for Oil Well Cement

    Directory of Open Access Journals (Sweden)

    Ming Li

    2017-01-01

    Full Text Available A terpolymer comprised of sodium styrene sulfonate (SSS, fumaric acid (FA, and acrylamide (AM was synthesized by aqueous free radical copolymerization and evaluated as fluid loss additive for oil well cement. The chemical structure and performance of the terpolymer were characterized by Fourier transform infrared (FTIR spectroscopy and thermal gravimetric analysis (TGA; the molecular weight and its distribution were determined by gel permeation chromatography (GPC. The optimum reaction conditions of polymerization were obtained: a reaction temperature of 50°C, a mass ratio of SSS/FA/AM 4 : 2 : 14, initiator 0.1%, and reaction time of 4 h; characterization indicated that the SSS/FA/AM had a certain molecular weight and excellent temperature-resistant and salt-resistant properties. The results show that SSS/FA/AM has a good fluid loss performance, in which the API fluid loss of the oil cement slurry could be controlled within 100 mL at 160°C. In addition, it had little effect on the cement compressive strength. The results of scanning electron microscopy (SEM of the filter cake showed that SSS/FA/AM could be adsorbed on the surface of the cement particles and produce a hydrated layer to prevent fluid loss from the oil well cement.

  4. Synthesis, characterization, and property of biodegradable PEG-PCL-PLA terpolymers with miktoarm star and triblock architectures as drug carriers.

    Science.gov (United States)

    Zhang, Yixin; Luo, Song; Liang, Yan; Zhang, Hai; Peng, Xinyu; He, Bin; Li, Sai

    2018-03-01

    A series of amphiphilic terpolymers with miktoarm star and triblock architectures of poly(ethylene glycol) (PEG), poly(ε-caprolactone) (PCL) and poly(l-lactide acid) (PLLA) or poly(DL-lactide acid) (PDLLA) terpolymers were synthesized as carriers for drug delivery. The architecture, molecular weight and crystallization behavior of the terpolymers were characterized. Anticancer drug doxorubicin was encapsulated in the micelles to investigate their drug loading properties. The miktoarm star terpolymers exhibited stronger crystallization capability, smaller size and better stability than that of triblock polymeric micelle, owing to the lower CMC values of miktoarm star polymeric micelle. Furthermore, the drug-loaded miktoarm star polymeric micelles showed the cumulative DOX release account of the micelles with PDLLA blocks was 65.3% while the release account of the corresponding micelles containing PLLA blocks was 45.2%. The IC 50 values of drug-loaded miktoarm star polymeric micelle were lower than triblock polymeric micelle. Meanwhile, Confocal laser scanning microscopy (CLSM) and Flow Cytometry results demonstrated that the miktoarm star micelles were more favorable for cellular internalization. The miktoarm star micelles with PDLLA blocks were promising carriers for anticancer drug delivery.

  5. Triblock and pentablock terpolymers by sequential base-assisted living cationic copolymerization of functionalized vinyl ethers

    KAUST Repository

    Bouchekif, Hassen; Sulhami, A. I.; AlGhamdi, Rayed D.; Gnanou, Yves; Hadjichristidis, Nikolaos

    2015-01-01

    A series of novel, well-defined triblock (PnBVE-b-PCEVE-b-PSiDEGVE) and pentablock (PSiDEGVE-b-PCEVE-b-PnBVE-b-PCEVE-b-PSiDEGVE) terpolymers of n-butyl vinyl ether (nBVE), 2-chloroethyl vinyl ether (CEVE) and tert-butyldimethylsilyl ethylene glycol vinyl ether (SiEGVE) were synthesized by sequential base-assisted living cationic polymerization. The living character of the homopolymerization of the three VE monomers and the crossover reaction resulting in the formation of well-defined block copolymers were investigated in various solvents (toluene, dichloromethane and n-hexane) using either a monofunctional [nBVE-acetic acid adduct (nBEA), CEVE-acetic acid adduct (CEEA) and SiDEGVE-acetic acid adduct (SiDEGEA)] or a difunctional [1,4-cyclohexane-1,4-diyl bis(2-methoxyethyl acetate) (cHDMEA)] initiator. All initiators are structurally equivalent to the dormant species of the corresponding monomers in order to achieve fast initiation. The optimal conditions of polymerization were achieved in n-hexane at -20 °C, in the presence of 1 M AcOEt (base). Good control over the number average molecular weight (Mn) and the polydispersity index (PDI) was obtained only at [Et3Al2Cl3]0 = [Chain-end]0 ≤ 10 mM. 2,6-Di-tert-butylpyridine (DtBP) was used as a non-nucleophilic proton trap to suppress any protonic initiation from moisture (i.e., Et3Al2Cl3·H2O). Well-defined PnBVEn-b-PCEVEp-b-PSiDEGVEq and PSiDEGVEq-b-PCEVEp-b-PnBVEn-b-PCEVEp-b-PSiDEGVEq terpolymers with a high crossover efficiency, no PCEVE-induced physical gelation, and predictable Mn and PDI < 1.15 were synthesized successfully provided that the targeted DPCEVE/DPnBVE ratio (i.e., p/n) did not exceed 2 and 0.2, respectively. The quantitative desilylation of the PSiEGVE by n-Bu4N+F- in THF at 0 °C led to triblock and pentablock terpolymers in which the PCEVE is the central block and the polyalcohol is the outer block. The thermal properties of the synthesized materials were examined by differential scanning

  6. Elastocaloric effect in poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) terpolymer

    Science.gov (United States)

    Yoshida, Yukihiro; Yuse, Kaori; Guyomar, Daniel; Capsal, Jean-Fabien; Sebald, Gael

    2016-06-01

    The elastocaloric properties of poly (vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) [P(VDF-TrFE-CTFE)] terpolymer were directly characterized using an infrared imaging camera. At a strain of 12%, a reversible adiabatic temperature variation of 2.15 °C was measured, corresponding to an isothermal entropy variation of 21.5 kJ m-3 K-1 or 11 J kg-1 K-1. In comparison with other elastocaloric materials, P(VDF-TrFE-CTFE) appears to represent a trade-off between the large required stresses in shape memory alloys and the large required strains in natural rubber. The internal energy of the P(VDF-TrFE-CTFE) polymer was found to be independent of the strain, resulting in complete conversion of the mechanical work into heat, as for pure elastomeric materials. The elastocaloric effect therefore originates from a pure entropic elasticity, which is likely to be related to the amorphous phase of the polymer only.

  7. Linking experiment and theory for three-dimensional networked binary metal nanoparticle–triblock terpolymer superstructures

    KAUST Repository

    Li, Zihui

    2014-02-21

    © 2014 Macmillan Publishers Limited. Controlling superstructure of binary nanoparticle mixtures in three dimensions from self-assembly opens enormous opportunities for the design of materials with unique properties. Here we report on how the intimate coupling of synthesis, in-depth electron tomographic characterization and theory enables exquisite control of superstructure in highly ordered porous three-dimensional continuous networks from single and binary mixtures of metal nanoparticles with a triblock terpolymer. Poly(isoprene-block-styrene-block-(N,N-dimethylamino)ethyl methacrylate) is synthesized and used as structure-directing agent for ligand-stabilized platinum and gold nanoparticles. Quantitative analysis provides insights into short-and long-range nanoparticle-nanoparticle correlations, and local and global contributions to structural chirality in the networks. Results provide synthesis criteria for next-generation mesoporous network superstructures from binary nanoparticle mixtures for potential applications in areas including catalysis.

  8. Well-defined Polymethylene-Based Co/Terpolymers by Combining Anthracene/Maleimide Diels-Alder Reaction with Polyhomologation

    KAUST Repository

    Hadjichristidis, Nikolaos

    2015-05-26

    A novel strategy towards well-defined polymethylene-based co/terpolymers, by combining anthracene/maleimide Diels-Alder reaction with polyhomologation, is presented. For the synthesis of diblock copolymers the following approach was applied: a) synthesis of α-anthracene-ω-hydroxy- polymethylene by polyhomologation using tri (9-anthracene-methyl propyl ether) borane as initiator, b) synthesis of furan-protected-maleimide-terminated poly (ε-caprolactone) or polyethylene glycol and c). Diels-Alder reaction between the anthracene and maleimide-terminated polymers. In the case of triblock terpolymers the α-anthracene-ω-hydroxy-polymethylene was used as macroinitiator for the ring-opening polymerization of D, L-lactide to afford an anthracene-terminated PM-b-PLA copolymer, followed by Diels-Alder reaction with furan-protected maleimide-terminated poly (ε-caprolactone) or polyethylene glycol to give the triblock terpolymers. All intermediate and final products were characterized by SEC, 1H NMR, UV-VIS spectroscopy and DSC.

  9. Impact of structural changes on dielectric and thermal properties of vinylidene fluoride–trifluoroethylene-based terpolymer/copolymer blends

    Energy Technology Data Exchange (ETDEWEB)

    Casar, G. [Jožef Stefan Institute and Jožef Stefan International Postgraduate School, Jamova 39, SI-1000 Ljubljana (Slovenia); Li, X. [Department of Electrical Engineering and Materials Research Institute, The Pennsylvania State University, University Park, PA 16802 (United States); Malič, B. [Jožef Stefan Institute and Jožef Stefan International Postgraduate School, Jamova 39, SI-1000 Ljubljana (Slovenia); Zhang, Q.M. [Department of Electrical Engineering and Materials Research Institute, The Pennsylvania State University, University Park, PA 16802 (United States); Bobnar, V., E-mail: vid.bobnar@ijs.si [Jožef Stefan Institute and Jožef Stefan International Postgraduate School, Jamova 39, SI-1000 Ljubljana (Slovenia)

    2015-03-15

    We report dielectric and thermal properties of the poly(vinylidene fluoride–trifluoroethylene–chlorofluoroethylene) terpolymer [P(VDF–TrFE–CFE), a member of the relaxor polymer family that exhibits fast response speeds, giant electrostriction, high electric energy density, and large electrocaloric effect] blended with the ferroelectric poly(vinylidene fluoride–trifluoroethylene) copolymer, P(VDF–TrFE). Although the differential scanning calorimetry (DSC) clearly reveals that both components form separate crystalline phases, at low copolymer content blends entirely exhibit a relaxorlike linear dielectric response, since the interfacial couplings to the bulky defects in the terpolymer convert the normal ferroelectric copolymer into a relaxor. On the other hand, dielectric experiments evidence that in blends with 20–50 wt% of P(VDF–TrFE) the ferroelectric and relaxor states coexist. This coexistence is confirmed by DSC results, which further reveal the influence of blending on the terpolymer crystallinity and melting point. At last, the crystallinity data appropriately explain the variation of the dielectric constant in P(VDF–TrFE–CFE)/P(VDF–TrFE) blends.

  10. estudo comparativo

    OpenAIRE

    Álvaro, Rocha

    2005-01-01

    O sítio web é um importante meio de comunicação e competitividade das universidades. Há diferentes razões para acreditar que os sítios possam variar entre universidades, mas contudo há certeza da existência de requisitos de qualidade comuns e transversais a todas. Este estudo visou avaliar, de forma quantitativa e objectiva, o cumprimento de requisitos de qualidade pelos sítios web das Universidades Portuguesas, com base nas características de alto nível da norma ISO 9126-1 que interessam aos...

  11. Understanding the structure and performance of self-assembled triblock terpolymer membranes

    KAUST Repository

    Pendergast, MaryTheresa M.; Mika Dorin, Rachel; Phillip, William A.; Wiesner, Ulrich; Hoek, Eric M.V.

    2013-01-01

    Nanoporous membranes represent a possible route towards more precise particle and macromolecular separations, which are of interest across many industries. Here, we explored membranes with vertically-aligned nanopores formed from a poly(isoprene-. b-styrene-. b-4 vinyl pyridine) (ISV) triblock terpolymer via a hybrid self-assembly/nonsolvent induced phase separation process (S-NIPS). ISV concentration, solvent composition, and evaporation time in the S-NIPS process were varied to tailor ordering of the selective layer and produce enhanced water permeability. Here, water permeability was doubled over previous versions of ISV membranes. This was achieved by increasing volatile solvent concentration, thereby decreasing the evaporation period required for self-assembly. Fine-tuning was required, however, since overly-rapid evaporation did not yield the desired pore structure. Transport models, used to relate the in-. situ structure to the performance of these materials, revealed narrowing of pores and blocking by the dense region below. It was shown that these vertically aligned nanoporous membranes compare favorably with commercial ultrafiltration membranes formed by NIPS and track-etching processes, which suggests that there is practical value in further developing and optimizing these materials for specific industrial separations. © 2013 Elsevier B.V.

  12. Self-assembly of Polystyrene- b -poly(2-vinylpyridine)- b -poly(ethylene oxide) Triblock Terpolymers

    KAUST Repository

    Musteata, Valentina-Elena; Sutisna, Burhannudin; Polymeropoulos, Georgios; Avgeropoulos, Apostolos; Meneau, Florian; Peinemann, Klaus-Viktor; Hadjichristidis, Nikolaos; Nunes, Suzana Pereira

    2017-01-01

    Polystyrene-b-poly(2-vinylpyridine)-b-poly(ethylene oxide) (PS-b-P2VP-b-PEO) terpolymer is a versatile polymer to form isoporous films and membranes, due to the possibility of self-assembly control and the properties of the different blocks, such as the P2VP ability of complexation, and H-bond formation, and the PEO biocompatibility. Copolymers with different block ratios and sizes were synthesized. The correlation between their equilibrium bulk morphology, the self-assembly in dilute and semi-dilute solutions and the non-equilibrium porous structures of membranes, obtained by non-solvent induced phase separation, was investigated and discussed in detail. The characterization was performed by small-angle X-ray scattering (SAXS), scanning (SEM) and transmission electron microscopy (TEM). Hexagonal, cubic and lamellar arrangements were observed. The preparation conditions were optimized and a regular, isoporous morphology, suitable for membrane application, was successfully obtained with PS80.5k-b-P2VP64.4k-b-PEO16.1k.

  13. Understanding the structure and performance of self-assembled triblock terpolymer membranes

    KAUST Repository

    Pendergast, MaryTheresa M.

    2013-10-01

    Nanoporous membranes represent a possible route towards more precise particle and macromolecular separations, which are of interest across many industries. Here, we explored membranes with vertically-aligned nanopores formed from a poly(isoprene-. b-styrene-. b-4 vinyl pyridine) (ISV) triblock terpolymer via a hybrid self-assembly/nonsolvent induced phase separation process (S-NIPS). ISV concentration, solvent composition, and evaporation time in the S-NIPS process were varied to tailor ordering of the selective layer and produce enhanced water permeability. Here, water permeability was doubled over previous versions of ISV membranes. This was achieved by increasing volatile solvent concentration, thereby decreasing the evaporation period required for self-assembly. Fine-tuning was required, however, since overly-rapid evaporation did not yield the desired pore structure. Transport models, used to relate the in-. situ structure to the performance of these materials, revealed narrowing of pores and blocking by the dense region below. It was shown that these vertically aligned nanoporous membranes compare favorably with commercial ultrafiltration membranes formed by NIPS and track-etching processes, which suggests that there is practical value in further developing and optimizing these materials for specific industrial separations. © 2013 Elsevier B.V.

  14. Preparation and Characterization of Amphiphilic Triblock Terpolymer-Based Nanofibers as Antifouling Biomaterials

    KAUST Repository

    Cho, Youngjin

    2012-05-14

    Antifouling surfaces are critical for the good performance of functional materials in various applications including water filtration, medical implants, and biosensors. In this study, we synthesized amphiphilic triblock terpolymers (tri-BCPs, coded as KB) and fabricated amphiphilic nanofibers by electrospinning of solutions prepared by mixing the KB with poly(lactic acid) (PLA) polymer. The resulting fibers with amphiphilic polymer groups exhibited superior antifouling performance to the fibers without such groups. The adsorption of bovine serum albumin (BSA) on the amphiphilic fibers was about 10-fold less than that on the control surfaces from PLA and PET fibers. With the increase of the KB content in the amphiphilic fibers, the resistance to adsorption of BSA was increased. BSA was released more easily from the surface of the amphiphilic fibers than from the surface of hydrophobic PLA or PET fibers. We have also investigated the structural conformation of KB in fibers before and after annealing by contact angle measurements, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and coarse-grained molecular dynamics (CGMD) simulation to probe the effect of amphiphilic chain conformation on antifouling. The results reveal that the amphiphilic KB was evenly distributed within as-spun hybrid fibers, while migrated toward the core from the fiber surface during thermal treatment, leading to the reduction in antifouling. This suggests that the antifouling effect of the amphiphilic fibers is greatly influenced by the arrangement of amphiphilic groups in the fibers. © 2012 American Chemical Society.

  15. Self-assembly of Polystyrene- b -poly(2-vinylpyridine)- b -poly(ethylene oxide) Triblock Terpolymers

    KAUST Repository

    Musteata, Valentina-Elena

    2017-11-08

    Polystyrene-b-poly(2-vinylpyridine)-b-poly(ethylene oxide) (PS-b-P2VP-b-PEO) terpolymer is a versatile polymer to form isoporous films and membranes, due to the possibility of self-assembly control and the properties of the different blocks, such as the P2VP ability of complexation, and H-bond formation, and the PEO biocompatibility. Copolymers with different block ratios and sizes were synthesized. The correlation between their equilibrium bulk morphology, the self-assembly in dilute and semi-dilute solutions and the non-equilibrium porous structures of membranes, obtained by non-solvent induced phase separation, was investigated and discussed in detail. The characterization was performed by small-angle X-ray scattering (SAXS), scanning (SEM) and transmission electron microscopy (TEM). Hexagonal, cubic and lamellar arrangements were observed. The preparation conditions were optimized and a regular, isoporous morphology, suitable for membrane application, was successfully obtained with PS80.5k-b-P2VP64.4k-b-PEO16.1k.

  16. A fed-batch strategy to produce high poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-4-hydroxybutyrate) terpolymer yield with enhanced mechanical properties in bioreactor.

    Science.gov (United States)

    Aziz, Nursolehah Abd; Huong, Kai-Hee; Sipaut, Coswald Stephen; Amirul, A A

    2017-11-01

    This study reports an efficient fed-batch strategy to improve poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-4-hydroxybutyrate) [P(3HB-co-3HV-co-4HB)] terpolymer production by Cupriavidus sp. USMAA2-4 with enhanced mechanical properties in bioreactor. The cultivations have been performed by combining oleic acid with γ-butyrolactone at different concentration ratios with 1-pentanol at a fixed concentration. The batch and fed-batch fermentations have resulted in P(3HB-co-3HV-co-4HB) with compositions of 9-35 mol% 3HV and 4-24 mol% 4HB monomers. The DO-stat fed-batch fermentation strategies have significantly improved the production with a maximum 4.4-fold increment of cell dry weight (CDW). Besides, appropriate feeding of the substrates has resulted in an increment of terpolymer productivity from 0.086-0.347 g/L/h, with a significantly shortened cultivation time. The bacterial growth and terpolymer formation have been found to be affected by the concentration of carbon sources supplied. Characterization of P(3HB-co-3HV-co-4HB) has demonstrated that incorporation of 3HV and 4HB monomer has significantly improved the physical and thermodynamic properties of the polymers, by reducing the polymer's crystallinity. The tensile strength, Young's modulus of the terpolymer has been discovered to increase with the increase of M w . The fed-batch fermentation strategies employed in this study have resulted in terpolymers with a range of flexible materials having improved tensile strength and Young's modulus as compared to the terpolymer produced from batch fermentation. Possession of lower melting temperature indicates an enhanced thermal stability which broadens the polymer processing window.

  17. Poly (ethylene oxide)-block-poly (n-butyl acrylate)-blockpoly (acrylic acid) triblock terpolymers with highly asymmetric hydrophilic blocks: synthesis and aqueous solution properties

    OpenAIRE

    Petrov, P. (Petar); Yoncheva, K. (Krassimira); Mokreva, P. (Pavlina); Konstantinov, S. (Spiro); Irache, J.M. (Juan Manuel); Müller, A.H.E. (Axel H.E.)

    2013-01-01

    The synthesis and aggregation behaviour in aqueous media of novel amphiphilic poly(ethylene oxide)- block-poly(n-butyl acrylate)-block-poly(acrylic acid) (PEO–PnBA–PAA) triblock terpolymers were studied. Terpolymers composed of two highly asymmetric hydrophilic PEO (113 monomer units) and PAA (10–17 units) blocks, and a longer soft hydrophobic PnBA block (163 or 223 units) were synthesized by atom transfer radical polymerisation (ATRP) of n-butyl acrylate and tert-butyl acrylate ...

  18. Diblock Terpolymers Are Tunable and pH Responsive Vehicles To Increase Hydrophobic Drug Solubility for Oral Administration.

    Science.gov (United States)

    Tale, Swapnil; Purchel, Anatolii A; Dalsin, Molly C; Reineke, Theresa M

    2017-11-06

    Synthetic polymers offer tunable platforms to create new oral drug delivery vehicles (excipients) to increase solubility, supersaturation maintenance, and bioavailability of poorly aqueous soluble pharmaceutical candidates. Five well-defined diblock terpolymers were synthesized via reversible addition-fragmentation chain transfer polymerization (RAFT) and consist of a first block of either poly(ethylene-alt-propylene) (PEP), poly(N-isopropylacrylamide) (PNIPAm), or poly(N,N-diethylaminoethyl methacrylate) (PDEAEMA) and a second hydrophilic block consisting of a gradient copolymer of N,N-dimethylacrylamide (DMA) and 2-methacrylamidotrehalose (MAT). This family of diblock terpolymers offers hydrophobic, hydrophilic, or H-bonding functionalities to serve as noncovalent sites of drug binding. Drug-polymer spray dried dispersions (SDDs) were created with a model drug, probucol, and characterized by differential scanning calorimetry (DSC). These studies revealed that probucol crystallinity decreased with increasing H-bonding sites available in the polymer. The PNIPAm-b-P(DMA-grad-MAT) systems revealed the best performance at pH 6.5, where immediate probucol release and effective maintenance of 100% supersaturation was found, which is important for facilitating drug solubility in more neutral conditions (intestinal environment). However, the PDEAEMA-b-P(DMA-grad-MAT) system revealed poor probucol dissolution at pH 6.5 and 5.1. Alternatively, at an acidic pH of 3.1, a rapid and high dissolution profile and effective supersaturation maintenance of up to 90% of the drug was found, which could be useful for triggering drug release in acidic environments (stomach). The PEP-b-P(DMA-grad-MAT) system showed poor performance (only ∼20% of drug solubility at pH 6.5), which was attributed to the low solubility of the polymers in the dissolution media. This work demonstrates the utility of diblock terpolymers as a potential new excipient platform to optimize design parameters for

  19. Injectable hydrogel as stem cell scaffolds from the thermosensitive terpolymer of NIPAAm/AAc/HEMAPCL

    Directory of Open Access Journals (Sweden)

    Lian S

    2012-09-01

    Full Text Available Sheng Lian,1Yan Xiao,1 Qingqing Bian,1Yu Xia,2 Changfa Guo,2 Shenguo Wang,2 Meidong Lang11Shanghai 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, People's Republic of China; 2Department of Cardiac Surgery, Zhongshan Hospital, Fudan University and Shanghai Institute of Cardiovascular Diseases, Shanghai, People's Republic of ChinaAbstract: A series of biodegradable thermosensitive copolymers was synthesized by free radical polymerization with N-isopropylacrylamide (NIPAAm, acrylic acid (AAc and macromer 2-hydroxylethyl methacrylate-poly(ε-caprolactone (HEMAPCL. The structure and composition of the obtained terpolymers were confirmed by proton nuclear magnetic resonance spectroscopy, while their molecular weight was measured using gel permeation chromatography. The copolymers were dissolved in phosphate-buffered saline (PBS solution (pH = 7.4 with different concentrations to prepare hydrogels. The lower critical solution temperature (LCST, cloud point, and rheological property of the hydrogels were determined by differential scanning calorimetry, ultraviolet-visible spectrometry, and rotational rheometry, respectively. It was found that LCST of the hydrogel increased significantly with the increasing NIPAAm content, and hydrogel with higher AAc/HEMAPCL ratio exhibited better storage modulus, water content, and injectability. The hydrogels were formed by maintaining the copolymer solution at 37°C. The degradation experiment on the formed hydrogels was conducted in PBS solution for 2 weeks and demonstrated a less than 20% weight loss. Scanning electron microscopy was also used to study the morphology of the hydrogel. The copolymer with NIPAAm/AAc/HEMAPCL ratio of 88:9.6:2.4 was bioconjugated with type I collagen for the purpose of biocompatibility enhancement. In-vitro cytotoxicity

  20. Histopathological Evaluation of a Hydrophobic Terpolymer (PTFE-PVD-PP) as an Implant Material for Nonpenetrating Very Deep Sclerectomy.

    Science.gov (United States)

    Leszczynski, Rafal; Gumula, Teresa; Stodolak-Zych, Ewa; Pawlicki, Krzysztof; Wieczorek, Jaroslaw; Kajor, Maciej; Blazewicz, Stanislaw

    2015-08-01

    The purpose of the study was to assess the biocompatibility of porous terpolymer (polytetrafluoroethylene-co-polyvinylidene fluoride-co-polypropylene, PTFE-PVDF-PP) membranes as an implant material to be placed during nonpenetrating very deep sclerectomy (NPVDS). Another study objective was to determine whether the polymer membrane under investigation could be used to manufacture a new-generation implant, which would actively delay the process of fistula closure and facilitate aqueous humor drainage. Histological response and tissue tolerance of the implant material were assessed. The study was performed on 38 eyeballs of 19 New Zealand white rabbits (19 implanted, 19 control). Histological assessment was carried out between 2 and 52 weeks after surgery. We routinely assessed inflammatory infiltrate, neovascularization, hemorrhage, and stromal edema as well as connective tissue attachment to the implant and adjacent tissues. At 52 weeks of observation, a statistically significant difference was revealed between the study and control groups in terms of resorptive granulation, tissue, and the inflammatory infiltrate. No features of acute inflammatory response to the implant were observed, and there was an absence of histological features of acute inflammatory infiltrates and subsidence of chronic inflammatory infiltrates and resorptive granulation over time. Slight fibrotic response and insignificant changes in neighboring eye tissues all indicate good tolerance to bioimplant materials. This allows for some optimism regarding the use of hydrophobic terpolymer in the construction of new intrascleral implants. However, the ultimate decision regarding its usefulness and safety in the treatment of glaucoma requires further investigation.

  1. How the Complex Interplay between Different Blocks Determines the Isothermal Crystallization Kinetics of Triple-Crystalline PEO-b-PCL-b-PLLA Triblock Terpolymers

    KAUST Repository

    Palacios, Jordana K.; Zhao, Junpeng; Hadjichristidis, Nikolaos; Mü ller, Alejandro J.

    2017-01-01

    PEO-b-PCL-b-PLLA triblock terpolymers are fascinating triple-crystalline materials. In this work, the isothermal crystallization kinetics of these terpolymers evaluated by differential scanning calorimetry (DSC) is presented for the first time and compared to analogous PCL-b-PLLA diblock copolymers and to PLLA, PCL, and PEO homopolymers. The results are complemented by in situ SAXS/WAXS synchrotron experiments. One-, two-, and three-step crystallization protocols were employed to study the crystallization kinetics of the blocks. At PLLA block crystallization temperatures, both PCL and PEO molten chains caused a strong plasticizing effect on the PLLA block crystallization, and the overall crystallization rate of the PLLA block in the terpolymers was higher than that in the PLLA-b-PCL diblock copolymers. In the case of the PCL block, the crystallization was followed after PLLA was fully crystallized (two-step crystallization). A nucleating effect induced by the previously formed PLLA crystals was observed. However, an antiplasticizing effect on PCL crystallization was detected if the sample is quenched directly from the melt to the PCL crystallization temperature (one-step crystallization). Finally, the crystallization of the PEO block was followed after PLLA and PCL had fully crystallized (three-step crystallization). The PEO crystallization rate highly decreased due to the confinement imposed by the previously formed PLLA and PCL crystals. Complex competitive effects such as plasticization, nucleation, antiplasticization, and confinement occurred during the isothermal crystallization of tricrystalline PEO-b-PCL-b-PLLA triblock terpolymers.

  2. How the Complex Interplay between Different Blocks Determines the Isothermal Crystallization Kinetics of Triple-Crystalline PEO-b-PCL-b-PLLA Triblock Terpolymers

    KAUST Repository

    Palacios, Jordana K.

    2017-12-05

    PEO-b-PCL-b-PLLA triblock terpolymers are fascinating triple-crystalline materials. In this work, the isothermal crystallization kinetics of these terpolymers evaluated by differential scanning calorimetry (DSC) is presented for the first time and compared to analogous PCL-b-PLLA diblock copolymers and to PLLA, PCL, and PEO homopolymers. The results are complemented by in situ SAXS/WAXS synchrotron experiments. One-, two-, and three-step crystallization protocols were employed to study the crystallization kinetics of the blocks. At PLLA block crystallization temperatures, both PCL and PEO molten chains caused a strong plasticizing effect on the PLLA block crystallization, and the overall crystallization rate of the PLLA block in the terpolymers was higher than that in the PLLA-b-PCL diblock copolymers. In the case of the PCL block, the crystallization was followed after PLLA was fully crystallized (two-step crystallization). A nucleating effect induced by the previously formed PLLA crystals was observed. However, an antiplasticizing effect on PCL crystallization was detected if the sample is quenched directly from the melt to the PCL crystallization temperature (one-step crystallization). Finally, the crystallization of the PEO block was followed after PLLA and PCL had fully crystallized (three-step crystallization). The PEO crystallization rate highly decreased due to the confinement imposed by the previously formed PLLA and PCL crystals. Complex competitive effects such as plasticization, nucleation, antiplasticization, and confinement occurred during the isothermal crystallization of tricrystalline PEO-b-PCL-b-PLLA triblock terpolymers.

  3. Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber

    Directory of Open Access Journals (Sweden)

    Siti Nurul Ain Md Jamil

    2014-09-01

    Full Text Available A synthesis of acrylonitrile (AN/butyl acrylate (BA/fumaronitrile (FN and AN/EHA (ethyl hexyl acrylate/FN terpolymers was carried out by redox polymerization using sodium bisulfite (SBS and potassium persulphate (KPS as initiator at 40 °C. The effect of comonomers, BA and EHA and termonomer, FN on the glass transition temperature (Tg and stabilization temperature was studied using Differential Scanning Calorimetry (DSC. The degradation behavior and char yield were obtained by Thermogravimetric Analysis. The conversions of AN, comonomers (BA and EHA and FN were 55%–71%, 85%–91% and 76%–79%, respectively. It was found that with the same comonomer feed (10%, the Tg of AN/EHA copolymer was lower at 63 °C compared to AN/BA copolymer (70 °C. AN/EHA/FN terpolymer also exhibited a lower Tg at 63 °C when compared to that of the AN/BA/FN terpolymer (67 °C. By incorporating BA and EHA into a PAN system, the char yield was reduced to ~38.0% compared to that of AN (~47.7%. It was found that FN reduced the initial cyclization temperature of AN/BA/FN and AN/EHA/FN terpolymers to 228 and 221 °C, respectively, in comparison to that of AN/BA and AN/EHA copolymers (~260 °C. In addition, FN reduced the heat liberation per unit time during the stabilization process that consequently reduced the emission of volatile group during this process. As a result, the char yields of AN/BA/FN and AN/EHA/FN terpolymers are higher at ~45.1% and ~43.9%, respectively, as compared to those of AN/BA copolymer (37.1% and AN/EHA copolymer (38.0%.

  4. Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber.

    Science.gov (United States)

    Jamil, Siti Nurul Ain Md; Daik, Rusli; Ahmad, Ishak

    2014-09-01

    A synthesis of acrylonitrile (AN)/butyl acrylate (BA)/fumaronitrile (FN) and AN/EHA (ethyl hexyl acrylate)/FN terpolymers was carried out by redox polymerization using sodium bisulfite (SBS) and potassium persulphate (KPS) as initiator at 40 °C. The effect of comonomers, BA and EHA and termonomer, FN on the glass transition temperature (T g ) and stabilization temperature was studied using Differential Scanning Calorimetry (DSC). The degradation behavior and char yield were obtained by Thermogravimetric Analysis. The conversions of AN, comonomers (BA and EHA) and FN were 55%-71%, 85%-91% and 76%-79%, respectively. It was found that with the same comonomer feed (10%), the T g of AN/EHA copolymer was lower at 63 °C compared to AN/BA copolymer (70 °C). AN/EHA/FN terpolymer also exhibited a lower T g at 63 °C when compared to that of the AN/BA/FN terpolymer (67 °C). By incorporating BA and EHA into a PAN system, the char yield was reduced to ~38.0% compared to that of AN (~47.7%). It was found that FN reduced the initial cyclization temperature of AN/BA/FN and AN/EHA/FN terpolymers to 228 and 221 °C, respectively, in comparison to that of AN/BA and AN/EHA copolymers (~260 °C). In addition, FN reduced the heat liberation per unit time during the stabilization process that consequently reduced the emission of volatile group during this process. As a result, the char yields of AN/BA/FN and AN/EHA/FN terpolymers are higher at ~45.1% and ~43.9%, respectively, as compared to those of AN/BA copolymer (37.1%) and AN/EHA copolymer (38.0%).

  5. Ab initio pseudopotential theory

    International Nuclear Information System (INIS)

    Yin, M.T.; Cohen, M.L.

    1982-01-01

    The ab initio norm-conserving pseudopotential is generated from a reference atomic configuration in which the pseudoatomic eigenvalues and wave functions outside the core region agree with the corresponding ab initio all-electron results within the density-functional formalism. This paper explains why such pseudopotentials accurately reproduce the all-electron results in both atoms and in multiatomic systems. In particular, a theorem is derived to demonstrate the energy- and perturbation-independent properties of ab initio pseudopotentials

  6. Thermal oxidation of epdm terpolymer and vulcanizate; Oxydation thermique d`un polymere epdm et d`un vulcanisat

    Energy Technology Data Exchange (ETDEWEB)

    Pinel, B.; Verdu, J. [Electricite de France (EDF), 92 - Clamart (France). Direction des Etudes et Recherches; Gueguen, V.; Audouin, L.

    1996-12-31

    Thermal ageing tests were made in the range 110-160 deg. C., on an ethylene-propylene-hexadiene terpolymer and with a filled, stabilised and vulcanized industrial rubber based on it. Carbonyl build-up, weight loss, density, chemiluminescence and removable fraction kinetic curves reveal an induction period whose duration is almost independent of the measurement method. These results suggest that the hypothesis of spatially heterogeneous (at small scale) oxidation is to be rejected in this case. They reveal the interest of density measurement for the detection of the end of the induction period, and the fact that variations of the soluble fraction are due to changes of the solubility parameter rather than to changes of the molecular weight/crosslink density. (authors). 11 refs.

  7. Redução e substituição do ácido crômico na etapa de condicionamento de ABS para metalização Reduction and replacement of chromic acid in step-conditioning of ABS for metallization

    Directory of Open Access Journals (Sweden)

    Ana Paula Kurek

    2009-01-01

    Full Text Available Na etapa de condicionamento de peças em acrilonitrila-butadieno-estireno (ABS, geralmente, são empregadas soluções sulfocrômicas, resultando na geração de efluentes altamente tóxicos e ambientalmente poluentes. Este trabalho apresenta resultados do estudo do emprego de soluções condicionantes visando à redução e substituição do ácido crômico. O condicionamento das amostras foi realizado em banhos contendo soluções de ácido crômico e ácido sulfúrico, permanganato de potássio e ácido fosfórico, e ácido sulfúrico, ácido fosfórico e dicromato de potássio, variando-se concentração, tempo de imersão e temperatura. A morfologia e estrutura da superfície das amostras foram analisadas por microscopia eletrônica de varredura (MEV, rugosidade e espectroscopia no infravermelho (FITR/ATR e a qualidade da adesão metálica após cromagem foi avaliada por inspeção visual, testes de adesão e de corrosão por exposição à névoa salina. Os resultados mostraram que o condicionamento químico ocasionou remoção dos componentes do ABS na superfície das amostras, provocando modificações como rugosidade e formação de poros, cavidades e reentrâncias, que influenciaram na adesão e foram dependentes da solução e das condições empregadas. O ácido crômico pode ser empregado em concentrações menores que a solução padrão (400 g.L-1 e soluções isentas deste foram eficientes na modificação da superfície e adesão metálica.In step-conditioning (etching of acrylonitrile-butadiene-styrene (ABS terpolymer, use is generally made of sulfuric/chromic acid solutions resulting in the generation of highly toxic, environmentally polluting waste. The present work reports the results of a study of reduction and replacement of chromic acid from the etching solution. The samples conditioning was carried out in baths containing solutions of chromic and sulfuric acids, potassium permanganate and phosphoric acid, and sulfuric

  8. One-pot synthesis of well-defined polyether/polyester block copolymers and terpolymers by a highly efficient catalyst switch approach

    KAUST Repository

    Alamri, Haleema

    2016-04-20

    A highly efficient methodology, based on a novel catalyst switch approach with rapid crossover characteristics, was developed for the one-pot synthesis of block co/terpolymers of cyclic ethers and esters. This new approach, which takes advantage of one of the best catalysts for epoxide (t-BuP4) and cyclic ester (t-BuP2) polymerization, opens new horizons toward the synthesis of cyclic ether/ester complex macromolecular architectures. © The Royal Society of Chemistry 2016.

  9. Sequential polymerization of ethylene oxide, ε-caprolactone and l-lactide: A one-pot metal-free route to tri- and pentablock terpolymers

    KAUST Repository

    Zhao, Junpeng

    2014-01-01

    Metal-free polymerization of ethylene oxide (EO) catalyzed by a relatively mild phosphazene base (t-BuP2) was proven feasible, which enabled the one-pot sequential polymerization of EO, ε-caprolactone, and l-lactide. Using either 3-phenyl-1-propanol or water as an initiator, the corresponding triblock or pentablock terpolymers were easily prepared. © 2014 the Partner Organisations.

  10. Novel thermo-responsive double-hydrophilic and hydrophobic MPEO-b-PEtOx-b-PCL triblock terpolymers: synthesis, characterization and self-assembly studies

    Czech Academy of Sciences Publication Activity Database

    Petrova, Svetlana; Venturini, Cristina Garcia; Jäger, Alessandro; Jäger, Eliezer; Černoch, Peter; Kereiche, S.; Kováčik, L.; Raška, I.; Štěpánek, Petr

    2015-01-01

    Roč. 59, 24 February (2015), s. 215-225 ISSN 0032-3861 R&D Projects: GA ČR GAP208/10/1600; GA MŠk(CZ) 7F14009 Institutional support: RVO:61389013 Keywords : MPEO-b-PEtOx-b-PCL triblock terpolymers * light-scattering * thermo-responsive nanoparticles Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.586, year: 2015

  11. Supramolecular self-assembly of novel thermo-responsive double-hydrophilic and hydrophobic Y-shaped [MPEO-b-PEtOx-b-(PCL)2] terpolymers

    Czech Academy of Sciences Publication Activity Database

    Petrova, Svetlana; Venturini, Cristina Garcia; Jäger, Alessandro; Jäger, Eliezer; Hrubý, Martin; Pavlova, Ewa; Štěpánek, Petr

    2015-01-01

    Roč. 5, č. 77 (2015), s. 62844-62854 ISSN 2046-2069 R&D Projects: GA MŠk(CZ) LH14079; GA MŠk(CZ) 7F14009 Institutional support: RVO:61389013 Keywords : Y-shaped [PEO-b-PEtOx-b-(PCL)2] terpolymers * light scattering * nanoparticles Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.289, year: 2015

  12. Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber

    OpenAIRE

    Jamil, Siti Nurul Ain Md; Daik, Rusli; Ahmad, Ishak

    2014-01-01

    A synthesis of acrylonitrile (AN)/butyl acrylate (BA)/fumaronitrile (FN) and AN/EHA (ethyl hexyl acrylate)/FN terpolymers was carried out by redox polymerization using sodium bisulfite (SBS) and potassium persulphate (KPS) as initiator at 40 °C. The effect of comonomers, BA and EHA and termonomer, FN on the glass transition temperature (Tg) and stabilization temperature was studied using Differential Scanning Calorimetry (DSC). The degradation behavior and char yield were obtained by Thermog...

  13. One-pot synthesis of well-defined polyether/polyester block copolymers and terpolymers by a highly efficient catalyst switch approach

    KAUST Repository

    Alamri, Haleema; Hadjichristidis, Nikolaos

    2016-01-01

    A highly efficient methodology, based on a novel catalyst switch approach with rapid crossover characteristics, was developed for the one-pot synthesis of block co/terpolymers of cyclic ethers and esters. This new approach, which takes advantage of one of the best catalysts for epoxide (t-BuP4) and cyclic ester (t-BuP2) polymerization, opens new horizons toward the synthesis of cyclic ether/ester complex macromolecular architectures. © The Royal Society of Chemistry 2016.

  14. Synthesis and thermal characterization of CdS nano crystals in previously formed template of maleic anhydride-octene 1-vinyl butyl terpolymer

    International Nuclear Information System (INIS)

    Akbarov, O.H; Mammadova, R.E; Malikov, E.Y.

    2008-01-01

    Full text: Nano crystals have dimensions in the range 10100 nm. Crystals in this size range possess unique properties, which enable scientists to manufacture materials and devices capable of performing unimaginable tasks. For that reason synthesis of this semiconductor nano crystals is expedient. Many useful methods have been used for preparing sulphide semiconductor nano crystals, such as colloidal chemistry method, sol-gel method, inverse micelle method, in situ synthesis and assemble on polymer template. The most significant method is in situ synthesis and assemble of sulphide semiconductor nano crystals on polymer. Compared with other methods, the stability of nanoparticles is improved by the protection and confinement of the copolymer. Because of confinement and protection effects of template environmental risk is prevented in this method. On the base of this principles in situ synthesis of CdS nano crystals in maleic anhydride-octene 1-vinyl butyl terpolymer was realized in this scientific work. First of all in specific condition maleic anhydride, octene 1, and vinyl butyl ether were polymerized to form a terpolymer as the result of radical ter polymerization. In second step CdS nano crystals were synthesized in N,N-dimethylformamide solution of maleic anhydride-octene 1-vinyl butyl terpolymer through the reaction of thiourea with cadmium chloride. In this process CdCI 2 x 2.5H 2 O was dissolved in N,N-dimethylformamide solution of previously formed terpolymer and was heated in 90 0 C temperature for 4 hours with vigorous stirring. Then desired amount of thiourea in N,N-dimethylformamide was quickly injected into the reaction flask using a syringe. The reaction continued for another 1 hour, and a yellow clear solution was obtained, which indicated the formation of CdS nano crystals

  15. Thermoresponsive behaviour of terpolymers containing poly(ethylene oxide), poly(2-ethyl-2-oxazoline) and poly(.epsilon.-caprolactone) blocks in aqueous solutions: an NMR study

    Czech Academy of Sciences Publication Activity Database

    Konefal, Rafal; Spěváček, Jiří; Jäger, Eliezer; Petrova, Svetlana

    2016-01-01

    Roč. 294, č. 11 (2016), s. 1717-1726 ISSN 0303-402X R&D Projects: GA ČR(CZ) GA15-13853S; GA MŠk(CZ) 7F14009 Institutional support: RVO:61389013 Keywords : thermoresponsive polymer * terpolymer containing poly(ethylene oxide), poly(2-ethyl-2-oxazoline) and poly(epsilon-caprolactone) blocks * nanoparticles Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.723, year: 2016

  16. An ab initio molecular

    Indian Academy of Sciences (India)

    mechanisms of two molecular crystals: An ab initio molecular dynamics ... for Computation in Molecular and Materials Science and Department of Chemistry, School of ..... NSAF Foundation of National Natural Science Foun- ... Matter 14 2717.

  17. Radiation processed polychloroprene-co-ethylene-propene diene terpolymer blends: Effect of radiation vulcanization on solvent transport kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, K.A. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Room No. S-1, HIRUP Building, Trombay, Mumbai 400 085 (India); Bhardwaj, Y.K. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Room No. S-1, HIRUP Building, Trombay, Mumbai 400 085 (India)], E-mail: ykbhard@barc.gov.in; Chaudhari, C.V.; Kumar, Virendra; Goel, N.K.; Sabharwal, S. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Room No. S-1, HIRUP Building, Trombay, Mumbai 400 085 (India)

    2009-03-15

    Blends of polychloroprene rubber (PCR) and ethylene propylene diene terpolymer rubber (EPDM) of different compositions were made and exposed to different gamma radiation doses. The radiation sensitivity and radiation vulcanization efficiency of blends was estimated by gel-content analysis, Charlesby-Pinner parameter determination and crosslinking density measurements. Gamma radiation induced crosslinking was most efficient for EPDM (p{sub 0}/q{sub 0} {approx} 0.08), whereas it was the lowest for blends containing 40% PCR (p{sub 0}/q{sub 0} {approx} 0.34). The vulcanized blends were characterized for solvent diffusion characteristics by following the swelling dynamics. Blends with higher PCR content showed anomalous swelling. The sorption and permeability of the solvent were not strictly in accordance with each other and the extent of variation in two parameters was found to be a function of blend composition. The {delta}G values for solvent diffusion were in the range -2.97 to -9.58 kJ/mol and indicated thermodynamically favorable sorption for all blends. These results were corroborated by dynamic swelling, experimental as well as simulated profiles and have been explained on the basis of correlation between crosslinking density, diffusion kinetics, thermodynamic parameters and polymer-polymer interaction parameter.

  18. Dynamically formed hydrous zirconium (IV) oxide-polyelectrolyte membranes. III: Poly(acrylic acid) and substituted poly(acrylic acid) homo, co and terpolymer membranes

    International Nuclear Information System (INIS)

    Van Reenen, A.J.; Sanderson, R.D.

    1989-01-01

    A series of acrylic acid and substituted acrylic acid homo, co and terpolymers was synthesised. These polymers were used as polyelectrolytes in dynamically formed hydrous zirconium (iv) oxide-polyelectrolyte membranes. Substitution of the acrylic acid α-hydrogen was done to increase the number of carboxylic acid groups per monomer unit and to change the acid strength of acrylic acid carboxylic acid group. None of these changes improved the salt rejection of these membranes over that of commercially used poly(acrylic acid). Improvement in rejection was found when a hydrophobic comonomer, vinyl acetate, was used in conjunction with acrylic acid in a copolymer dynamic membrane. 16 refs., 6 figs., 1 tab

  19. Studies on preparing and adsorption property of grafting terpolymer microbeads of PEI-GMA/AM/MBA for bilirubin.

    Science.gov (United States)

    Gao, Baojiao; Lei, Haibo; Jiang, Liding; Zhu, Yong

    2007-06-15

    Crosslinking copolymer microbeads with a diameter range of 100-150 microm were synthesized by suspension copolymerization of glycidyl methacrylate (GMA), acrylamide (AM) and N,N'-methylene bisacrylamide (MBA). Subsequently, polyethyleneimine (PEI) was grafted on the surfaces of the terpolymer microbeads GMA/AM/MBA via the ring-opening reaction of the epoxy groups, and the grafting microbeads PEI-GMA/AM/MBA were prepared. In this paper, the adsorption property of the grafting microbeads for bilirubin was mainly investigated, and the effects of various factors, such as pH value, ionic strength and grafting degree of PEI on the surface of grafting microbeads and the adsorption capacity of the grafting microbeads for bilirubin were examined. The batch adsorption experiment results show that by right of the action of grafted polyamine macromolecules PEI, the grafting microbeads PEI-GMA/AM/MBA have quite strong adsorption ability for bilirubin; the isotherm adsorption conforms to Freundlich equation. The pH value of the medium affects the adsorption capacity greatly, As in the nearly neutral solutions with pH 6, the grafting microbeads have the strongest adsorption ability for bilirubin, whereas in acidic and basic solutions their adsorption ability is weak. The ionic strength hardly affects the adsorption ability of the grafting microbeads. The grafting degree of PEI on the surfaces of the grafting microbeads also has a great effect on the adsorption capacity, and higher the grafting degree of PEI on the surface of the microbead PEI-GMA/AM/MBA, the stronger is the adsorption ability of the microbeads.

  20. Synthesis of Terpolymers with Homogeneous Composition by Free Radical Copolymerization of Maleic Anhydride, Perfluorooctyl and Butyl or Dodecyl Methacrylates: Application of the Continuous Flow Monomer Addition Technique

    Directory of Open Access Journals (Sweden)

    Marian Szkudlarek

    2017-11-01

    Full Text Available Terpolymers of homogeneous composition were prepared by free radical copolymerization of butyl or dodecyl methacrylate, 1H,1H,2H,2H-perfluorodecyl methacrylate and maleic anhydride using the continuous monomer addition technique. The copolymerization reactions were performed at 65 °C in the presence of azobisisobutyronitrile as an initiator in a mixture of methyl ethyl ketone and 1,3-bis (trifluoromethylbenzene. The monomers and initiator are added to the reaction mixture with the same rate they are consumed in 5- and 10-fold excess compared to the initial monomer stock. The obtained terpolymers with molecular weights Mn = 50,000–70,000 are of uniform composition, close to the composition determined in low conversion experiments, proving the principle of the chosen concept. The kinetic data necessary for the design of the continuous addition experiment were obtained from binary copolymerization experiments at low monomer conversion (to avoid compositional drift. In addition, the so-called terpolymerization parameter was determined from ternary copolymerization experiments.

  1. Triblock-Terpolymer-Directed Self-Assembly of Mesoporous TiO2: High-Performance Photoanodes for Solid-State Dye-Sensitized Solar Cells

    KAUST Repository

    Docampo, Pablo

    2012-04-30

    A new self-assembly platform for the fast and straightforward synthesis of bicontinuous, mesoporous TiO 2 films is presented, based on the triblock terpolymer poly(isoprene - b - styrene - b - ethylene oxide). This new materials route allows the co-assembly of the metal oxide as a fully interconnected minority phase, which results in a highly porous photoanode with strong advantages over the state-of-the-art nanoparticle-based photoanodes employed in solidstate dye-sensitized solar cells. Devices fabricated through this triblock terpolymer route exhibit a high availability of sub-bandgap states distributed in a narrow and low enough energy band, which maximizes photoinduced charge generation from a state-of-the-art organic dye, C220. As a consequence, the co-assembled mesoporous metal oxide system outperformed the conventional nanoparticle-based electrodes fabricated and tested under the same conditions, exhibiting solar power-conversion efficiencies of over 5%. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Triblock-Terpolymer-Directed Self-Assembly of Mesoporous TiO2: High-Performance Photoanodes for Solid-State Dye-Sensitized Solar Cells

    KAUST Repository

    Docampo, Pablo; Stefik, Morgan; Guldin, Stefan; Gunning, Robert; Yufa, Nataliya A.; Cai, Ning; Wang, Peng; Steiner, Ullrich; Wiesner, Ulrich; Snaith, Henry J.

    2012-01-01

    A new self-assembly platform for the fast and straightforward synthesis of bicontinuous, mesoporous TiO 2 films is presented, based on the triblock terpolymer poly(isoprene - b - styrene - b - ethylene oxide). This new materials route allows the co-assembly of the metal oxide as a fully interconnected minority phase, which results in a highly porous photoanode with strong advantages over the state-of-the-art nanoparticle-based photoanodes employed in solidstate dye-sensitized solar cells. Devices fabricated through this triblock terpolymer route exhibit a high availability of sub-bandgap states distributed in a narrow and low enough energy band, which maximizes photoinduced charge generation from a state-of-the-art organic dye, C220. As a consequence, the co-assembled mesoporous metal oxide system outperformed the conventional nanoparticle-based electrodes fabricated and tested under the same conditions, exhibiting solar power-conversion efficiencies of over 5%. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Viscometric investigation of compatibilization of the poly(vinyl chloride)/poly(ethylene-co-vinyl acetate) blends by terpolymer of maleic anhydride styrene vinyl acetate

    Science.gov (United States)

    İmren, Dilek; Boztuğ, Ali; Yılmaz, Ersen; Zengin, H. Bayram

    2008-11-01

    In this study, a blend of poly(vinyl chloride) (PVC)/ethylene-co-vinyl acetate (EVA) was compatibilized by terpolymer of maleic anhydride-styrene-vinyl acetate (MAStVA) used as a compatibilizer. It was prepared the blends of 50/50 PVC/EVA containing 2-10% of the terpolymer. The compatibility experiences of these blends were investigated by using viscometric method in the range of concentrations (0.5-2.0 g dL -1) where tetrahydrofuran (THF) is the solvent. The interaction parameter (Δ b) was used to study the miscibility and compatibility of polymer blend in solution, obtained from the modified Krigbaum and Wall theory. Turbidity and FTIR measurements were also used to investigate the miscibility of this pair of polymers. The values of the relative viscosities of the each polymer solution and their blends were measured by a Cannon-Fenske type viscometer. In consequence of the study, it was observed that a considerable improvement was achieved in the miscibility of PVC/EVA blends by adding among 5 and 10 wt% of compatibilizer.

  4. Well-defined polyethylene-based graft terpolymers by combining nitroxide-mediated radical polymerization, polyhomologation and azide/alkyne “click” chemistry†

    KAUST Repository

    Alkayal, Nazeeha

    2016-03-30

    Novel well–defined polyethylene–based graft terpolymers were synthesized via the “grafting onto” strategy by combining nitroxide-mediated radical polymerization (NMP), polyhomologation and copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC) “click” chemistry. Three steps were involved in this approach: (i) synthesis of alkyne-terminated polyethylene-b-poly(ε-caprolactone) (PE-b-PCL-alkyne) block copolymers (branches) by esterification of PE-b-PCL-OH with 4-pentynoic acid; the PE-b-PCL-OH was obtained by polyhomologation of dimethylsulfoxonium methylide to afford PE-OH, followed by ring opening polymerization of ε-caprolactone using the PE-OH as macroinitiator, (ii) synthesis of random copolymers of styrene (St) and 4-chloromethylstyrene (4-CMS) with various CMS contents, by nitroxide-mediated radical copolymerization (NMP), and conversion of chloride to azide groups by reaction with sodium azide (NaN3) (backbone) and (iii) “click” linking reaction to afford the PE-based graft terpolymers. All intermediates and final products were characterized by high-temperature size exclusion chromatography (HT-SEC), Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1H NMR) and differential scanning calorimetry (DSC).

  5. Triblock-terpolymer-directed self-assembly of mesoporous TiO{sub 2}: High-performance photoanodes for solid-state dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Docampo, Pablo; Gunning, Robert; Snaith, Henry J. [Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Stefik, Morgan; Wiesner, Ulrich [Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853 (United States); Guldin, Stefan; Yufa, Nataliya A.; Steiner, Ullrich [Department of Physics, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Cai, Ning; Wang, Peng [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2012-06-15

    A new self-assembly platform for the fast and straightforward synthesis of bicontinuous, mesoporous TiO{sub 2} films is presented, based on the triblock terpolymer poly(isoprene-b-styrene-b-ethylene oxide). This new materials route allows the co-assembly of the metal oxide as a fully interconnected minority phase, which results in a highly porous photoanode with strong advantages over the state-of-the-art nanoparticle-based photoanodes employed in solid-state dye-sensitized solar cells. Devices fabricated through this triblock terpolymer route exhibit a high availability of sub-bandgap states distributed in a narrow and low enough energy band, which maximizes photoinduced charge generation from a state-of-the-art organic dye, C220. As a consequence, the co-assembled mesoporous metal oxide system outperformed the conventional nanoparticle-based electrodes fabricated and tested under the same conditions, exhibiting solar power-conversion efficiencies of over 5%. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. AB Manpower Plan 2007

    CERN Document Server

    Myers, Stephen

    2007-01-01

    The present exercise is not as such a "manpower plan" but a purely budgetary comparison of known plus requested resources with the known commitments over the period 2007-2012. From a purely budgetary point of view, AB will have the capacity to maintain all those recently hired staff who fulfill the criteria for long term employment at CERN. Following this budgetary exercise, AB proposes to perform a CERN-wide staff work plan so as to compare the manpower available to the quantity of work to be done in the totality of the work-packages. If there is a significant mismatch between these two quantities then we propose the following measures which would create personnel economies and allow us to redress the mismatch by increased recruitment: a new job severance scheme; CERN restructuring; use of the new CERN-ITER agreement; more flexibility in transfers from Materials to Personnel budgets. Failing this a re-examination of possible closure of lower priority facilities may be needed.

  7. Estudos de atmosfera

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Riccioppo

    2016-11-01

    Full Text Available Joker e Estudos de balística possuíam formas distintas dos cadernos ou livros quando foram exibidos pela primeira vez, na mostra Dual Overdrive. De algum modo, o flagrante das imagens dos cartazes da campanha política parisiense e daquelas cusparadas sobre o asfalto era preservado no modo como eram mostrados os trabalhos, que repunham não apenas a orientação espacial dos objetos fotografados, mas, igualmente, sua escala: Joker apresentava-se na parede, em dimensões relativamente próximas às dos cartazes lambe-lambe que retratavam; e Estudos de balística, no chão da galeria, também com ampliação suficiente para que se tivesse a impressão de que se tratava de imagens “em tamanho real”.

  8. Outburst in Mira AB?

    Science.gov (United States)

    Karovska, Margarita

    2003-09-01

    The nearby system Mira AB composed of an aging AGB star (Mira A) and a WD companion (Mira B) offers a unique laboratory for studying wind accretion processes, a poorly understood phenomenon in many sources. Recent Chandra ACIS-S Obs.(70ks on 12/6/03; PI.M.Karovska) resolved for the first time the components (~0.6") in X-rays, and detected a new bright soft source (A. This is the first detection of X-rays from an AGB star. This source was not detected by ROSAT in 1993 or recently by XMM 8/03 (AAS/03,J.Kastner), and could be a transient phenomenon. Model fitting shows that the soft X-ray emission is likely several emission lines, rather then a continuum; with ACIS spectral resolution we cannot resolve or identify these lines. We propose a 40ks LETG+HRC-S obs. to identify the lines and determine the emission mechanism.

  9. Estudos de atmosfera

    OpenAIRE

    Carlos Eduardo Riccioppo

    2016-01-01

    Joker e Estudos de balística possuíam formas distintas dos cadernos ou livros quando foram exibidos pela primeira vez, na mostra Dual Overdrive. De algum modo, o flagrante das imagens dos cartazes da campanha política parisiense e daquelas cusparadas sobre o asfalto era preservado no modo como eram mostrados os trabalhos, que repunham não apenas a orientação espacial dos objetos fotografados, mas, igualmente, sua escala: Joker apresentava-se na parede, em dimensões relativamente próximas às d...

  10. um estudo de caso

    OpenAIRE

    Costa, Cátia Filipa Pereira da

    2011-01-01

    Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Psicologia Jurídica As situações de abuso sexual de crianças nas quais o perpetrador pertence ao sexo feminino obtiveram ao longo dos últimos anos um acrescido reconhecimento por parte da comunidade científica, evidenciado pelo significativo incremento das investigações no âmbito desta temática consistindo na sua maioria estudos de caso. Um conjunto de particularidades encont...

  11. Estudo da adsorção de hidrogênio e sulfeto na superfície de paládio: aspectos experimentais (eletroquímica e teóricos (ab initio e Teoria do Funcional da Densidade

    Directory of Open Access Journals (Sweden)

    Ângelo Antônio Carlos D.

    2001-01-01

    Full Text Available The adsorption of H and S2- species on Pd (100 has been studied with ab initio, density-functional calculations and electrochemical methods. A cluster of five Pd atoms with a frozen geometry described the surface. The computational calculations were performed through the GAUSSIAN94 program, and the basis functions adapted to a pseudo-potential obtained by using the Generator Coordinate Method adapted to the this program. Using the cyclic voltammetry technique through a Model 283 Potentiostat/Galvanostat E.G.&G-PAR obtained the electrochemical results. The calculated chemisorption geometry has a Pd-H distance of 1.55Å, and the potential energy surface was calculated using the Becke3P86//(GCM/DFT/SBK methodology. The adsorption of S2- ions on Pd surface obtained both through comparison between the experimental and theoretical results, at MP2 level, suggest a S2- absorption into the metallic cluster. The produced Pd-(S2- system was show to be very stable under the employed experimental conditions. The paper has shows the powerful aid of computational methods to interpret adsorption experimental data.

  12. Clinical significance of combined detection of multiple serum antibodies (AsAb, EmAb, AcAb, AoAb, ToxAb) in infertile women

    International Nuclear Information System (INIS)

    Chen Jing; Jiang Li; Lu Ya

    2005-01-01

    Objective: To determine the clinical significance of combined detection of multiple serum antibodies in infertile women. Methods; Serum multiple antibodies were examined in 120 infertile women, including 88 failed to get pregnancy and 32 with repeated spontaneous abortion. The antibodies tested were: (1) anti-sperm antibody (AsAb) (2) endometrial antibody (EmAb) (3) anti-cardiophospholipid antibody (AcAb) (4) Anti-ovarian antibody (AoAb) and Toxoplasmosis antibody (ToxAb). Results: In 48 of the infertile women, none of the five antibodies were positive (40% of 120). The rest were: one antibody positive--38/120 or 31.6%; two antibodies positive--31/120 or 25.83%, three and four antibodies positive--4/120 or 3.33%. None of the women were positive with all five antibodies. Conclusion: Immune factor was the chief cause of infertility in women. (authors)

  13. Ab initio vel ex eventu

    Science.gov (United States)

    Thiessen, P. A.; Treder, H.-J.

    Der gegenwärtige Stand der physikalischen Erkenntnis, in Sonderheit die Atomistik und die Quantentheorie, ermöglicht (in wohldefinierten Energie-Bereichen) eine ab initio-Berechnung aller physikalischen und chemischen Prozesse und Strukturen. Die Schrödinger-Gleichung erlaubt zusammen mit den Prinzipien der Quantenstatistik (Pauli-Prinzip) aus dem Planckschen Wirkungsquantum h und den atomischen Konstanten die Berechnung aller Energieumsätze, Zeitabläufe etc., die insbesondere die chemische Physik bestimmen. Die Rechenresultate gelten auch quantitativ bis auf die unvermeidliche Stochastik.Die ab initio-Berechnungen korrespondieren einerseits und sind andererseits komplementär zu den auf den Methoden der theoretischen Chemie und der klassischen Thermodynamik beruhenden Ergebnissen ex eventu. Die theoretische Behandlung ab initio führt zu mathematischen Experimenten, die die Laboratoriums-Experimente ergänzen oder auch substituieren.Translated AbstractAb initio vel ex eventuThe present state of physical knowledge, in peculiar atomistic and quantum theory, makes an ab initio calculation of all physical and chemical processes and structures possible (in well defined reaches of energy). The Schrödinger equation together with the principles of quantum statistics (Pauli principle) permits from the Planck and atomistic constants to calculate all exchanges of energy, courses of time, etc. which govern chemical physics. The calculated results are valid even quantitatively apart from the unavoidable stochastics.These ab initio calculations on the one hand correspond and are on the other complimentary to results ex eventu based on the methods of theoretical chemistry and classical thermodynamics. Theoretical treatment ab initio leads to mathematical experiments which add to or even substitute experiments in the laboratory.

  14. Macromolecular Engineering: New Routes Towards the Synthesis of Well-??Defined Polyethers/Polyesters Co/Terpolymers with Different Architectures

    KAUST Repository

    Alamri, Haleema

    2016-05-18

    The primary objective of this research was to develop a new and efficient pathway for well-defined multicomponent homo/co/terpolymers of cyclic esters/ethers using an organocatalytic approach with an emphasis on the macromolecular engineering aspects of the overall synthesis. Macromolecular engineering (as discussed in the first chapter) of homo/copolymers refers to the specific tailoring of these materials for achieving an easy and reproducible synthesis that results in precise molecular characteristics, i.e. molecular weight and polydispersity, as well as specific structure and end?group choices. Precise control of these molecular characteristics will provide access to new materials that can be used for pre-targeted purposes such as biomedical applications. Among the most commonly used engineering materials are polyesters (biocompatible and biodegradable) and polyethers (biocompatible), either as homopolymers or when or copolymers with linear structures. The ability to create non-linear structures, for example stars, will open new horizons in the applications of these important polymeric materials. The second part of this thesis describes the synthesis of aliphatic polyesters, particularly polycaprolactone and polylactide, using a metal-free initiator/catalyst system. A phosphazene base (t?BuP2) was used as the catalyst for the ring-opening copolymerization of ?-aprolactone (??CL) and L,Lactide (LLA) at room temperature with a variety of protic initiators in different solvents. These studies provided important information for the design of a metal-free route toward the synthesis of polyester?based (bio) materials. The third part of the thesis describes a novel route for the one?pot synthesis of polyether-b polyester block copolymers with either a linear or a specific macromolecular architecture. Poly (styrene oxide)?b?poly(caprolactone)?b?poly(L,lactide) was prepared using this method with the goal of synthesizing poly(styrene oxide)-based materials since this

  15. Fine Tuning of Open-Circuit Voltage by Chlorination in Thieno[3,4- b ]thiophene–Benzodithiophene Terpolymers toward Enhanced Solar Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Shiwei; Wang, Huan; Mo, Daize; Chao, Pengjie; Yang, Zhen; Li, Longji; Tian, Leilei; Chen, Wei [Materials; Institute; He, Feng

    2017-06-22

    A new family of thieno[3,4-b]thiophene benzodithiophene terpolymers (PBTClx) have been designed and synthesized, in which the chlorine/fluorine content has been adjusted and optimized. As the content of chlorine is increased in polymers, the twist angle between the donor and acceptor is increased, which leads to a diminishment in the planarity and conjugation. As a result, the UV vis absorption is continuous blue-shifted, and the band gap increases from 1.57 to 2.04 eV when the chlorinated moieties increased from 0 to 100%. The highest occupied molecular orbital (HOMO) levels of those polymers are decreased by increasing the content of chlorinated moiety, which opens a window to constantly modify the V-oc values and eventually meets a balance point for optimized solar energy conversion. The highest power conversion efficiency of 8.31% is obtained by using PBTCl25 as the donor and PC71BM as the acceptor in polymer solar cells (PSCs), in which the Voc increased from 0.79 to 0.82 V after 25% chlorinated monomer involved in copolymerization. Herein, the chlorine replacement could be a good method to further pump the solar conversion by increasing the open circuit voltage without reducing other factors of the polymer solar cells.

  16. Water-base acrylic terpolymer as a corrosion inhibitor for SAE1018 in simulated sour petroleum solution in stagnant and hydrodynamic conditions

    International Nuclear Information System (INIS)

    Vakili Azghandi, M.; Davoodi, A.; Farzi, G.A.; Kosari, A.

    2012-01-01

    Highlights: ► Corrosion inhibition of a water-base copolymer, ATP, was studied. ► Efficiency more than 90% was obtained with 0.8 mmol/L ATP in 2000 rpm. ► ATP obeys Langmuir isotherm in static and hydrodynamic conditions. ► With the presence of ATP, OM images showed a decrease in surface attack. - Abstract: The effect of static and hydrodynamic conditions (0–2000 rpm) on corrosion inhibition of a water-base acrylic terpolymer (ATP), methyl methacrylate/butyl acrylate/acrylic acid, for SAE1018 steel in simulated sour petroleum corrosive solution (NACE 1D196) were investigated by AC/DC electrochemical tests. Increase in rotation speed accelerates the corrosion rate; however the corrosion inhibitor efficiency increases. This was attributed to the enhanced mass transport of inhibitor molecules to the metal surface. OM examinations also demonstrate that in presence of ATP, a decrease in corrosion attacks is observed. Thermodynamic calculations also showed that ATP obeys Langmuir adsorption isotherm and adsorbs chemically into the surface.

  17. pH-Dependent doxorubicin release from terpolymer of starch, polymethacrylic acid and polysorbate 80 nanoparticles for overcoming multi-drug resistance in human breast cancer cells.

    Science.gov (United States)

    Shalviri, Alireza; Raval, Gaurav; Prasad, Preethy; Chan, Carol; Liu, Qiang; Heerklotz, Heiko; Rauth, Andrew Michael; Wu, Xiao Yu

    2012-11-01

    This work investigated the capability of a new nanoparticulate system, based on terpolymer of starch, polymethacrylic acid and polysorbate 80, to load and release doxorubicin (Dox) as a function of pH and to evaluate the anticancer activity of Dox-loaded nanoparticles (Dox-NPs) to overcome multidrug resistance (MDR) in human breast cancer cells in vitro. The Dox-NPs were characterized by Fourier transform infrared spectroscopy (FTIR), isothermal titration calorimetry (ITC), transmission electron microscopy (TEM), and dynamic light scattering (DLS). The cellular uptake and cytotoxicity of the Dox-loaded nanoparticles were investigated using fluorescence microscopy, flow cytometry, and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay. The nanoparticles were able to load up to 49.7±0.3% of Dox with a high loading efficiency of 99.9±0.1%, while maintaining good colloidal stability. The nanoparticles released Dox at a higher rate at acidic pH attributable to weaker Dox-polymer molecular interactions evidenced by ITC. The Dox-NPs were taken up by the cancer cells in vitro and significantly enhanced the cytotoxicity of Dox against human MDR1 cells with up to a 20-fold decrease in the IC50 values. The results suggest that the new terpolymeric nanoparticles are a promising vehicle for the controlled delivery of Dox for treatment of drug resistant breast cancer. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Hydrophobic surface modification of TiO2 nanoparticles for production of acrylonitrile-styrene-acrylate terpolymer/TiO2 composited cool materials

    Science.gov (United States)

    Qi, Yanli; Xiang, Bo; Tan, Wubin; Zhang, Jun

    2017-10-01

    Hydrophobic surface modification of TiO2 was conducted for production of acrylonitrile-styrene-acrylate (ASA) terpolymer/titanium dioxide (TiO2) composited cool materials. Different amount of 3-methacryloxypropyl-trimethoxysilane (MPS) was employed to change hydrophilic surface of TiO2 into hydrophobic surface. The hydrophobic organosilane chains were successfully grafted onto TiO2 through Sisbnd Osbnd Ti bonds, which were verified by Fourier transformed infrared spectra and X-ray photoelectron spectroscopy. The water contact angle of the sample added with TiO2 modified by 5 wt% MPS increased from 86° to 113°. Besides, all the ASA/TiO2 composites showed significant improvement in both solar reflectance and cooling property. The reflectance of the composites throughout the near infrared (NIR) region and the whole solar wavelength is increased by 113.92% and 43.35% compared with pristine ASA resin. Simultaneously, significant drop in temperature demonstrates excellent cooling property. A maximum decrease approach to 27 °C was observed in indoor temperature test, while a decrease around 9 °C tested outdoors is achieved.

  19. A facile method of hydrophobic surface modification for acrylonitrile-styrene-acrylate terpolymer based on the out-migration property of metallic soaps

    Science.gov (United States)

    Qi, Yanli; Chen, Tingting; Zhang, Jun

    2018-03-01

    Hydrophobic surface modification is conducted in this study by using additives with long alkyl chains. Several kinds of metallic soaps, such as calcium stearate (CaSt), zinc stearate (ZnSt), magnesium stearate (MgSt) and barium stearate (BaSt) were employed. Polymer matrix is acrylonitrile-styrene-acrylate (ASA) terpolymer due to its wonderful weather resistance property. The surface chemical characterization was studied by Fourier transformed infrared (FTIR) technology and X-ray photoelectron spectroscopy (XPS). Carboxylate (Osbnd Csbnd O-) indexes of composites in both transmittance and reflection modes were calculated according to FTIR results. As to the ratio of carboxylate index in reflection mode to that in transmittance mode, the sample added with 5 wt% ZnSt shows a higher value of 8.77, and a much higher value of 14.47 for the sample added with 10 wt% ZnSt. The corresponding Csbnd C/ Csbnd H /Cdbnd C peak areas of the samples added with 5 wt% or 10 wt% ZnSt are 75.4% and 77.3% respectively, much higher than other samples. This indicates ZnSt is much easier to out-migrate to material surface and therefore is more suitable for hydrophobic surface modification. In particular, the water contact angle of the ASA/ZnSt composite added with 10 wt% ZnSt significantly increased to 127o (40o increase in comparison with pure ASA), successfully converting the surface wettability from hydrophilic to hydrophobic.

  20. Extraction of Proteins with ABS

    NARCIS (Netherlands)

    Desai, R.K.; Streefland, M.; Wijffels, R.H.; Eppink, M.H.M.

    2016-01-01

    Over the past years, there has been an increasing trend in research on the extraction and purification of proteins using aqueous biphasic systems (ABS) formed by polymers, e.g., polyethylene glycol (PEG). In general, when dealing with protein purification processes, it is essential to maintain their

  1. Ab initio potential for solids

    DEFF Research Database (Denmark)

    Chetty, N.; Stokbro, Kurt; Jacobsen, Karsten Wedel

    1992-01-01

    . At the most approximate level, the theory is equivalent to the usual effective-medium theory. At all levels of approximation, every term in the total-energy expression is calculated ab initio, that is, without any fitting to experiment or to other calculations. Every step in the approximation procedure can...

  2. Ab-initio ZORA calculations

    NARCIS (Netherlands)

    Faas, S.; Snijders, Jaap; van Lenthe, J.H.; HernandezLaguna, A; Maruani, J; McWeeny, R; Wilson, S

    2000-01-01

    In this paper we present the first application of the ZORA (Zeroth Order Regular Approximation of the Dirac Fock equation) formalism in Ab Initio electronic structure calculations. The ZORA method, which has been tested previously in the context of Density Functional Theory, has been implemented in

  3. Tuberculose infantil: estudo retrospectivo

    Directory of Open Access Journals (Sweden)

    Boaventura Antonio dos Santos

    2011-10-01

    Full Text Available Introdução: A tuberculose (TB infantil permanece como uma das doenças mais prevalentes e preocupantes no mundo, sobretudo em nações em desenvolvimento, onde as taxas são ainda mais elevadas e os casos descritos subestimados pela dificuldade em se estabelecer um diagnóstico definitivo. Dessa forma, este estudo tem como objetivo descrever o perfil clínico e epidemiológico dos pacientes com TB infantil pulmonar e extrapulmonar. Métodos: Foram avaliados retrospectivamente, através de questionário, pacientes com idade de até 15 anos, internados no Serviço de Pediatria do HCPA, no período de janeiro de 2002 a setembro de 2007.   Resultados: Dos 52 pacientes incluídos, 63% apresentavam TB pulmonar. Das formas extra-pulmonares, a meningoencefalite foi a mais prevalente (22%. Comorbidades foram dectadas em 31 (60% pacientes, dos quais 15 (29% apresentavam desnutrição grave, 9 (18% HIV positivo e 7 (13% pneumopatia crônica. Das manifestações clínicas, febre e tosse estavam presentes na maioria dos pacientes. O padrão radiológico predominante foi o de consolidação pulmonar (51%. A maioria dos pacientes referia história de contato com paciente bacilífero (64%. Conclusão: A TB pulmonar representa a principal forma de apresentação clínica da TB, sendo o diagnóstico feito de forma presuntiva na maioria dos casos. O diagnóstico baseado na comprovação bacteriológica foi obtido numa minoria de pacientes, demonstrando a importância dos achados clínico-laboratoriais, história epidemiológica e vacinal para o diagnóstico. Nesse sentido, a criação de escores tem se tornado uma ferramenta de fácil acesso e com razoável acurácia para auxiliar o diagnóstico de TB em serviços de baixa complexidade, especialmente o ambulatorial.

  4. Modeling of truck's braking dynamics with ABS

    Directory of Open Access Journals (Sweden)

    Maxym DYACHUK

    2014-09-01

    Full Text Available In the article some questions of ABS simulation on the basis of plane vehicle's dynamics and automatic modeling are considered. The author's algorithm of ABS modulators control is presented.

  5. Six years of experience in connection with the performance of ethylene-propylene-diene terpolymer Rubber (EPDM) geo membranes used in waterproofing reservoirs; Sesis anos de experiencia en el empleo de geomembranas de etileno-propileno-monomero dienico (EPDM) en la impermeabilizacion de balsas

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, M.; Aguiar, E.; Cea, J. C. de; Soriano, J.; Castillo, F.; Garcia, F.; Crespo, M. A.

    2008-07-01

    This paper provides to show the performance of synthetic geo membranes based on ethylene-propylene-diene terpolymer rubber (EPDM). Results after six years one applied are presented. The samples of geo membranes came from eight Spanish reservoirs: Bigastro, Bullas, La Casa de las Chumberas, el Boqueron, El Golfo, Los Dos Pinos, Los Pozos (La Torrecilla) and El Saltadero (experimental field). Characteristics of ethylene-propylene-diene terpolymer rubber were evaluated: tensile properties, impact resistance, static perforation, low temperature folding, joint strength (shear and peeling test), optic microscopy and electron microscopy scanner. (Author) 13 refs.

  6. AB Levitator and Electricity Storage

    OpenAIRE

    Bolonkin, Alexander

    2007-01-01

    The author researched this new idea - support of flight by any aerial vehicles at significant altitude solely by the magnetic field of the planet. It is shown that current technology allows humans to create a light propulsion (AB engine) which does not depend on air, water or ground terrain. Simultaniosly, this revolutionary thruster is a device for the storage of electricity which is extracted and is replenished (during braking) from/into the storage with 100 percent efficiency. The relative...

  7. Reação de genótipos de abóbora e morangas a Phytophthora capsici

    OpenAIRE

    Pereira, Ricardo B; Aguiar, Frederick M; Torres, Tiago B; Amaro, Geovani Bernardo; Lucas, Gilvaine C; Pinheiro, Jadir B

    2017-01-01

    RESUMO Phytophthora capsici causa prejuízos significativos em cultivos de abóbora (Cucurbita moschata) e morangas (Cucurbita maxima), incluindo a podridão de raízes e coroa, o crestamento foliar e a podridão de frutos, o que pode resultar em até 100% de perdas na produção. O objetivo deste estudo foi avaliar a reação de genótipos de abóboras e morangas a P. capsici. Inicialmente um experimento foi realizado para avaliar a agressividade de isolados de P. capsici de diferentes regiões. Posterio...

  8. ABS: Sequence alignment by scanning

    KAUST Repository

    Bonny, Mohamed Talal

    2011-08-01

    Sequence alignment is an essential tool in almost any computational biology research. It processes large database sequences and considered to be high consumers of computation time. Heuristic algorithms are used to get approximate but fast results. We introduce fast alignment algorithm, called Alignment By Scanning (ABS), to provide an approximate alignment of two DNA sequences. We compare our algorithm with the well-known alignment algorithms, the FASTA (which is heuristic) and the \\'Needleman-Wunsch\\' (which is optimal). The proposed algorithm achieves up to 76% enhancement in alignment score when it is compared with the FASTA Algorithm. The evaluations are conducted using different lengths of DNA sequences. © 2011 IEEE.

  9. ABS: Sequence alignment by scanning

    KAUST Repository

    Bonny, Mohamed Talal; Salama, Khaled N.

    2011-01-01

    Sequence alignment is an essential tool in almost any computational biology research. It processes large database sequences and considered to be high consumers of computation time. Heuristic algorithms are used to get approximate but fast results. We introduce fast alignment algorithm, called Alignment By Scanning (ABS), to provide an approximate alignment of two DNA sequences. We compare our algorithm with the well-known alignment algorithms, the FASTA (which is heuristic) and the 'Needleman-Wunsch' (which is optimal). The proposed algorithm achieves up to 76% enhancement in alignment score when it is compared with the FASTA Algorithm. The evaluations are conducted using different lengths of DNA sequences. © 2011 IEEE.

  10. AP calculus AB/BC

    CERN Document Server

    Schwartz, Stu

    2013-01-01

    All Access for the AP® Calculus AB & BC Exams Book + Web + Mobile Everything you need to prepare for the Advanced Placement® exam, in a study system built around you! There are many different ways to prepare for an Advanced Placement® exam. What's best for you depends on how much time you have to study and how comfortable you are with the subject matter. To score your highest, you need a system that can be customized to fit you: your schedule, your learning style, and your current level of knowledge. This book, and the free online tools that come with it, will help you personalize your AP® Cal

  11. Homology of ab1 and ab3 monoclonal antibodies that neutralize Semliki Forest virus

    NARCIS (Netherlands)

    Fernandez, IM; Bos, NA; Harmsen, M; Verheul, AFM; Snippe, H; Kraaijeveld, CA

    2001-01-01

    A noninternal image monoclonal antiidiotypic antibody (ab2 mAb), designated 1,13A321, that had proved its efficacy as vaccine against infection with Semliki Forest virus (SFV) in BALB/c mice, was used as immunogen to generate a panel of SFV-neutralizing monoclonal anti-anti-idiotypic antibodies (ab3

  12. Solvent (acetone-butanol: ab) production

    Science.gov (United States)

    This article describes production of butanol [acetone-butanol-ethanol, (also called AB or ABE or solvent)] by fermentation using both traditional and current technologies. AB production from agricultural commodities, such as corn and molasses, was an important historical fermentation. Unfortunately,...

  13. Avaliação da degradação térmica e fotooxidativa do ABS para fins de reciclagem Evaluation of thermal and photo-oxidative ABS degradation with recycling purposes

    Directory of Open Access Journals (Sweden)

    Elisabete Maria Saraiva Sanchez

    2003-07-01

    Full Text Available Este trabalho tem como objetivo avaliar a degradação térmica e fotooxidativa do terpolímero poli (acrilonitrila-butadieno-estireno, ABS, utilizado em componentes internos de automóveis. Corpos de prova de ABS moldados por injeção foram submetidos ao envelhecimento térmico, segundo a norma ASTM D794, e ao envelhecimento fotooxidativo segundo as normas ASTM G24 e G53. As amostras envelhecidas foram submetidas às análises dinâmico-mecânica, e microscópicas por microscopia de força atômica no modo não contato. Os resultados mostraram que as transições, tanto da fase vítrea quanto da fase elastomérica na superfície do ABS, são afetadas pela degradação. As áreas dos picos das curvas de módulo de perda em função da temperatura relativos às transições vítreas do ABS foram correlacionadas ao alongamento na ruptura, em função do tempo e tipo de envelhecimento. As propriedades mecânicas são influenciadas de forma mais acentuada pela extensão da degradação da matriz. O método de envelhecimento ASTM G24 mostrou-se mais agressivo que o G53, seja para a fase BR ou para a fase SAN. As imagens microscópicas mostraram que os diferentes envelhecimentos provocaram diferentes variações na rugosidade das superfícies. Amostras fotooxidadas, com perda de alongamento maior que 50%, foram reprocessadas e mostraram uma recuperação superior a 90% nessa propriedade.The aim of this work is the evaluation of thermal and photo-oxidative degradation of the terpolymer acrylonitrile-butadiene-styrene, ABS, used in internal automotive components. Injection molded specimens were aged by ASTM D794, ASTM G24 and ASTM G53 standards. The aged test specimens were studied by means of dynamic mechanical analysis and non-contact atomic force microscopy. The results revealed that the transitions of the glass and rubber phases were affected by the degradation. The area under linear loss modulus-temperature curves was related to tensile properties

  14. Estudo multicasos sobre atividades inovativas

    Directory of Open Access Journals (Sweden)

    Sonia Regina Hierro Parolin

    2013-09-01

    Full Text Available Em estudos sobre competitividade argumenta-se que as empresas necessitam de estratégias baseadas em inovações e de capacidades internas em constantes e intensas transformações, não somente nos padrões tecnológicos, mas também no encadeamento do processo de gestão das atividades inovativas, como processos dinâmicos, não lineares e diversificados, em função de múltiplos fatores dos ambientes interno e externo. Para contribuir com essas discussões, neste artigo apresenta-se um estudo multicasos em quatro indústrias de médio e grande portes, de segmentos, densidades tecnológicas e históricos com inovações diferentes entre si. Como principais resultados, salientam-se o encadeamento das atividades inovativas como parte de uma estratégia organizacional para obter resultados com inovação e a afluência de todas as pessoas, e não somente as alocadas em pesquisa e desenvolvimento, para o cumprimento dessa estratégia.

  15. Collective rotation from ab initio theory

    International Nuclear Information System (INIS)

    Caprio, M.A.; Maris, P.; Vary, J.P.; Smith, R.

    2015-01-01

    Through ab initio approaches in nuclear theory, we may now seek to quantitatively understand the wealth of nuclear collective phenomena starting from the underlying internucleon interactions. No-core configuration interaction (NCCI) calculations for p-shell nuclei give rise to rotational bands, as evidenced by rotational patterns for excitation energies, electromagnetic moments and electromagnetic transitions. In this review, NCCI calculations of 7–9 Be are used to illustrate and explore ab initio rotational structure, and the resulting predictions for rotational band properties are compared with experiment. We highlight the robustness of ab initio rotational predictions across different choices for the internucleon interaction. (author)

  16. AP calculus AB & BC crash course

    CERN Document Server

    Rosebush, J

    2012-01-01

    AP Calculus AB & BC Crash Course - Gets You a Higher Advanced Placement Score in Less Time Crash Course is perfect for the time-crunched student, the last-minute studier, or anyone who wants a refresher on the subject. AP Calculus AB & BC Crash Course gives you: Targeted, Focused Review - Study Only What You Need to Know Crash Course is based on an in-depth analysis of the AP Calculus AB & BC course description outline and actual AP test questions. It covers only the information tested on the exams, so you can make the most of your valuable study time. Written by experienced math teachers, our

  17. Spectral monitoring of AB Aur

    Science.gov (United States)

    Rodríguez Díaz, L. F.; Oostra, B.

    2017-07-01

    The Astronomical Observatory of the Universidad de los Andes in Bogotá, Colombia, did a spectral monitoring during 2014 and 2015 to AB Aurigae, the brightest Herbig Ae/be star in the northern hemisphere. The aim of this project is applying spectral techniques, in order to identify specific features that could help us not only to understand how this star is forming, but also to establish a pattern to explain general star formation processes. We have recorded 19 legible spectra with a resolving power of R = 11,0000, using a 40 cm Meade telescope with an eShel spectrograph, coupled by a 50-micron optical fiber. We looked for the prominent absorption lines, the Sodium doublet at 5890Å and 5896Å, respectively and Magnesium II at 4481Å; to measure radial velocities of the star, but, we did not find a constant value. Instead, it ranges from 15 km/s to 32 km/s. This variability could be explained by means of an oscillation or pulsation of the external layers of the star. Other variabilities are observed in some emission lines: Hα, Hβ, He I at 5876Å and Fe II at 5018Å. It seems this phenomenon could be typical in stars that are forming and have a circumstellar disk around themselves. This variability is associated with the nonhomogeneous surface of the star and the interaction that it has with its disk. Results of this interaction could be seen also in the stellar wind ejected by the star. More data are required in order to look for a possible period in the changes of radial velocity of the star, the same for the variability of He I and Fe II, and phenomena present in Hα. We plan to take new data in January of 2017.

  18. Colestase neonatal prolongada: estudo prospectivo

    Directory of Open Access Journals (Sweden)

    PRADO Elizabeth Teixeira Mendes Livramento

    1999-01-01

    Full Text Available Em razão da urgência de se decidir por um tratamento clínico ou por uma intervenção cirúrgica imediata, o estudo da colestase neonatal prolongada envolve dois objetivos básicos: o diagnóstico diferencial entre atresia biliar e hepatite neonatal e a pesquisa dos agentes etiológicos associados. Desta maneira, através de estudo prospectivo desenvolvido na década de 1970, foram avaliadas 77 crianças portadoras de colestase neonatal prolongada para estabelecer o diagnóstico diferencial entre atresia biliar e hepatite neonatal e, numa segunda fase, 108 crianças, visando esclarecer a etiopatogenia da colestase neonatal prolongada. Os resultados do diagnóstico diferencial revelaram que, dos 18 atributos avaliados, apenas oito mostraram-se bons indicadores de atresia biliar, em ordem decrescente: ductos proliferados (espaço-porta, fibrose (espaço-porta, colestase (espaço-porta, cor das fezes -- acolia, hepatomegalia, colestase canalicular (lóbulo, infiltrado (espaço-porta, células gigantes (lóbulo. Estes oito atributos foram então compostos, mediante uma ponderação, em um único indicador de grande poder discriminativo, capaz de decidir o diagnóstico diferencial em 99% dos casos. Quanto à etiopatogenia, registrou-se: vírus rubéola 0%, vírus herpes simples 0%, listeriose 0%, citomegalovirose 2,2%, vírus hepatite B 2,4%, toxoplasmose 2,8%, deficiência de alfa-1-antitripsina 13,1%, sífilis 21,1 %, auto-anticorpos hepáticos 58,4%. O trabalho desenvolvido mostra que as 8 variáveis mais decisivas, como indicadoras diferenciais entre atresia biliar e hepatite neonatal, permanecem como índices fundamentais, auxiliando, em conjunto com novos métodos diagnósticos, na composição de uma estratégia multifatorial cada vez menos invasiva e mais precisa. O estudo da etiopatogenia, dependente das condições epidemiológicas locais e da época, com a introdução de novos métodos diagnósticos, torna-se atualmente cada vez mais

  19. Clinical significance of determination of serum leptin and AsAb, EmAb levels in infertile women

    International Nuclear Information System (INIS)

    Luo Jian; Zhou Minglian; Sun Gang; He Haoming

    2010-01-01

    Objective: To study the clinical significance of determination of serum leptin, AsAb, and EmAb levels in infertile women. Methods: Serum leptin (with RIA) and AsAb, EmAb (with ELISA) levels were detected in 32 infertile women and 35 controls. Results: Serum leptin levels in infertile women were significantly lower than those in controls (P<0.01). Serum AsAb and EmAb were both positive in 25 of the 32 infertile women (78.1%) and EmAb (one of two Abs) was positive in the rest 7 women (21.9%). These positive rates were also significantly higher than the respective ones in the controls (both P<0.01). Conclusion: Lower serum leptin level with highly positive AsAb and EmAb might be the chief cause of infertility in women. (authors)

  20. Ab initio model of porous periclase

    International Nuclear Information System (INIS)

    Drummond, Neil D.; Swift, Damian C.; Ackland, Graeme J.

    2004-01-01

    A two-phase equilibrium equation of state (EOS) for periclase (MgO) was constructed using ab initio quantum mechanics, including a rigorous calculation of quasiharmonic phonon modes. Much of the shock wave data reported for periclase is on porous material. We compared the theoretical EOS with porous data using a simple 'snowplough' treatment and also a model using finite equilibration rates suitable for continuum mechanics simulations. (This model has been applied previously to various heterogeneous explosives as well as other porous materials.) The results were consistent and matched the data well at pressures above the regime affected by strength - and ramp-wave formation - during compaction. Ab initio predictions of the response of porous material have been cited recently as a novel and advanced capability; we feel that this is a fairly routine extension to established ab initio techniques

  1. Ab initio valence calculations in chemistry

    CERN Document Server

    Cook, D B

    1974-01-01

    Ab Initio Valence Calculations in Chemistry describes the theory and practice of ab initio valence calculations in chemistry and applies the ideas to a specific example, linear BeH2. Topics covered include the Schrödinger equation and the orbital approximation to atomic orbitals; molecular orbital and valence bond methods; practical molecular wave functions; and molecular integrals. Open shell systems, molecular symmetry, and localized descriptions of electronic structure are also discussed. This book is comprised of 13 chapters and begins by introducing the reader to the use of the Schrödinge

  2. Disturbios da olfacao: estudo retrospectivo

    Directory of Open Access Journals (Sweden)

    Luciano Lobato Gregorio

    2014-01-01

    Full Text Available Introdução: O olfato, fenômeno subjetivo de grande importância, é pouco compreendido e estudado no ser humano. Médicos com maior conhecimento sobre os distúrbios desse sentido tendem a considerar a doença mais importante e manejar melhor o diagnóstico e o tratamento. Objetivo: Descrever a amostra dos pacientes com queixa principal de distúrbios do olfato e mostrar a experiência do serviço no manejo e tratamento. Delineamento: Estudo retrospectivo de coorte histórica com corte transversal. Materiais e métodos: Descrição da amostra e avaliação de resposta ao tratamento de pacientes com queixa principal de hiposmia ou anosmia atendidos no ambulatório de Rinologia no período de janeiro de 2005 a outubro de 2011. Resultados: Dos 38 pacientes com distúrbio da olfação, 68,4% dos pacientes apresentaram queixa de hiposmia e 31,5% de anosmia, com duração média de 30,8 meses. Os diagnósticos etiológicos principais foram idiopática (31,5%, rinopatia alérgica (28,9% e RSC com pólipos (10,5%. As respostas ao tratamento com corticosteroide tópico e ácido alfa-lipoico foram variáveis, assim como na literatura. Conclusão: Maior importância deve ser dada aos distúrbios do olfato na prática do otorrinolaringologista, uma vez que o diagnóstico diferencial é amplo e pode trazer grande morbidade ao paciente, com impacto na sua qualidade de vida.

  3. Diode laser surgery. Ab interno and ab externo versus conventional surgery in rabbits.

    Science.gov (United States)

    Karp, C L; Higginbotham, E J; Edward, D P; Musch, D C

    1993-10-01

    Fibroblastic proliferation of subconjunctival tissues remains a primary mechanism of failure in filtration surgery. Minimizing the surgical manipulation of episcleral tissues may reduce scarring. Laser sclerostomy surgery involves minimal tissue dissection, and is gaining attention as a method of potentially improving filter duration in high-risk cases. Twenty-five New Zealand rabbits underwent filtration surgery in one eye, and the fellow eye remained as the unoperated control. Ten rabbits underwent ab externo diode laser sclerostomy surgery, ten underwent ab interno diode sclerostomy surgery, and five had posterior sclerostomy procedures. Filtration failure was defined as a less-than-4-mmHg intraocular pressure (IOP) difference between the operative and control eyes. The mean time to failure for the ab externo, ab interno, and conventional posterior sclerostomy techniques measured 17.4 +/- 11.5, 13.1 +/- 6.7, and 6.0 +/- 3.1 days, respectively. In a comparison of the laser-treated groups with the conventional procedure, the time to failure was significantly longer (P = 0.02) for the ab externo filter. The mean ab interno sclerostomy duration was longer than the posterior lip procedure, but this difference was not statistically significant (P = 0.15). The overall level of IOP reduction was similar in the three groups. These data suggest that diode laser sclerostomy is a feasible technique in rabbits, and the ab externo approach resulted in longer filter duration than the conventional posterior lip procedure in this model.

  4. Training in AB Department 2004/2005

    CERN Document Server

    Schinzel, Josi; CERN. Geneva. AB Department

    2006-01-01

    This note provides an overview of the training attended by members of the AB Department during the years 2004 and 2005, giving a break-down of the different courses and costs as well as training directions. It describes the organisation of training in the department, and evolution in training directions and planning.

  5. Ab Initio molecular dynamics with excited electrons

    NARCIS (Netherlands)

    Alavi, A.; Kohanoff, J.; Parrinello, M.; Frenkel, D.

    1994-01-01

    A method to do ab initio molecular dynamics suitable for metallic and electronically hot systems is described. It is based on a density functional which is costationary with the finite-temperature functional of Mermin, with state being included with possibly fractional occupation numbers.

  6. An ab initio and TD DFT

    Indian Academy of Sciences (India)

    The photophysical behaviour of N-(2-hydroxy benzylidene) aniline or most commonly known as salicylideneaniline (SA) has been investigated using the ab initio and DFT levels of theory. The quantum chemical calculations show that the optimized non planar enol (1) form of the SA molecule is the most stable conformer ...

  7. Study of processing conditions on properties of ABS and clay organically modified nanocomposites; Estudo das condicoes de processamento nas propriedades de nanocompositos de ABS e argilas organofilicas

    Energy Technology Data Exchange (ETDEWEB)

    Galvan, Danieli; Massucato, Felipe; Bartoli, Julio R., E-mail: bartoli@feq.unicamp.br [Fac. de Engenharia Quimica/Universidade Estadual de Campinas - DTP/FEQ/UNICAMP, Campinas, SP (Brazil); D' Avila, Marcos A. [Fac. de Engenharia Mecanica/Universidade Estadual de Campinas - DEMA/FEM/UNICAMP, Campinas, SP (Brazil); Fernandes, Elizabeth G. [Tezca P and D Celulas Solares, Campinas, SP (Brazil)

    2011-07-01

    Nanocomposites of poly(acrylonitrile-butadiene-styrene) and organically modified montmorillonite clay were prepared by melt intercalation on a co-rotating twin-screw extruder. The independent variables studied were the kind of organoclay (Cloisite 20A and Cloisite 30B) and the screw torque at levels of 45 and 70%. The effect of these variables on the intercalation/exfoliation were accessed by means of the morphological characteristics using X-ray diffraction and the mechanical properties of uniaxial tensile test. The experimental results showed that the incorporation of clay in the polymeric matrix improved the mechanical properties of elastic modulus, yield stress and tensile strength of nanocomposites, being more significant for that containing Cloisite 30B. Torque was also a significant variable for the responses studied. (author)

  8. Genetics Home Reference: GM2-gangliosidosis, AB variant

    Science.gov (United States)

    ... Resources Genetic Testing (1 link) Genetic Testing Registry: Tay-Sachs disease, variant AB General Information from MedlinePlus (5 links) ... AB variant Activator Deficiency/GM2 Gangliosidosis Activator-deficient Tay-Sachs disease GM2 Activator Deficiency Disease GM2 gangliosidosis, type AB ...

  9. ESTUDOS ESTILÍSTICOS NO BRASIL

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Falcão Uchôa

    2013-06-01

    Full Text Available Este artigo objetiva mostrar os inícios e a progressão dos estudos estilísticos no Brasil. Após uma introdução sobre o surgimento, na Europa, da Estilística como disciplina de pesquisa no campo da linguagem, detém-se, sucessivamente, nas contribuições de filólogos, linguistas, teóricos da literatura e gramáticos para o estudo dos mais variados recursos estilísticos ocorrentes sobretudo em autores brasileiros.

  10. Towards hydrogen metallization: an Ab initio approach

    International Nuclear Information System (INIS)

    Bernard, St.

    1998-01-01

    The quest for metallic hydrogen is a major goal for both theoretical and experimental condensed matter physics. Hydrogen and deuterium have been compressed up to 200 GPa in diamond anvil cells, without any clear evidence for a metallic behaviour. Loubeyere has recently suggested that hydrogen could metallize, at pressures within experimental range, in a new Van der Waals compound: Ar(H 2 ) 2 which is characterized at ambient pressure by an open and anisotropic sublattice of hydrogen molecules, stabilized by an argon skeleton. This thesis deals with a detailed ab initio investigation, by Car-Parrinello molecular dynamics methods, of the evolution under pressure of this compound. In a last chapter, we go to much higher pressures and temperatures, in order to compare orbital and orbital free ab initio methods for the dense hydrogen plasma. (author)

  11. Estudo teórico das interações Mg2+ e bases nucleotídicas

    OpenAIRE

    Prado, Maria Aparecida da Silva

    2006-01-01

    Neste trabalho, estudamos as formas de interação e as energias de complexação em sistemas compostos de bases nucleotídicas, íons Mg2+ e H2O, utilizando-se cálculos ab initio. A partir dos resultados obtidos, fizemos uma avaliação da aplicabilidade de campos de força e métodos semi-empíricos para estudar estes sistemas. Os cálculos ab initio de alto nível foram realizados com o objetivo de indicar, em primeiro lugar, os efeitos importantes e que devem ser considerados no estudo de tais sistema...

  12. Highly scalable Ab initio genomic motif identification

    KAUST Repository

    Marchand, Benoit; Bajic, Vladimir B.; Kaushik, Dinesh

    2011-01-01

    We present results of scaling an ab initio motif family identification system, Dragon Motif Finder (DMF), to 65,536 processor cores of IBM Blue Gene/P. DMF seeks groups of mutually similar polynucleotide patterns within a set of genomic sequences and builds various motif families from them. Such information is of relevance to many problems in life sciences. Prior attempts to scale such ab initio motif-finding algorithms achieved limited success. We solve the scalability issues using a combination of mixed-mode MPI-OpenMP parallel programming, master-slave work assignment, multi-level workload distribution, multi-level MPI collectives, and serial optimizations. While the scalability of our algorithm was excellent (94% parallel efficiency on 65,536 cores relative to 256 cores on a modest-size problem), the final speedup with respect to the original serial code exceeded 250,000 when serial optimizations are included. This enabled us to carry out many large-scale ab initio motiffinding simulations in a few hours while the original serial code would have needed decades of execution time. Copyright 2011 ACM.

  13. Ab interno trabeculectomy: patient selection and perspectives

    Science.gov (United States)

    Vinod, Kateki; Gedde, Steven J

    2016-01-01

    Ab interno trabeculectomy is one among several recently introduced minimally invasive glaucoma surgeries that avoid a conjunctival incision and full-thickness sclerostomy involved in traditional glaucoma surgery. Ablation of the trabecular meshwork and inner wall of Schlemm’s canal is performed in an arcuate fashion via a clear corneal incision, alone or in combination with phacoemulsification cataract surgery. Intraocular pressure reduction following ab interno trabeculectomy is limited by resistance in distal outflow pathways and generally stabilizes in the mid-to-high teens. Relief of medication burden has been demonstrated by some studies. A very low rate of complications, most commonly transient hyphema and intraocular pressure elevations in the immediate postoperative period, have been reported. However, available data are derived from small retrospective and prospective case series. Randomized, controlled trials are needed to better elucidate the potential merits of ab interno trabeculectomy in the combined setting versus phacoemulsification cataract surgery alone and to compare it with other minimally invasive glaucoma surgeries. PMID:27574396

  14. O desamparo aprendido revisitado: estudos com animais

    Directory of Open Access Journals (Sweden)

    Maria Helena Leite Hunziker

    Full Text Available O desamparo aprendido tem sido definido como a dificuldade de aprendizagem apresentada por indivíduos que tiveram experiência prévia com estímulos aversivos incontroláveis. O objetivo deste trabalho é fazer uma revisão crítica dos estudos sobre o desamparo aprendido, com animais. Nessa análise, são considerados aspectos conceituais e metodológicos dos estudos em questão e as interpretações teóricas sobre esse efeito comportamental. Aborda-se a evolução histórica desses estudos, bem como alguns aspectos controversos das publicações que se acumularam ao longo de quatro décadas de pesquisa. A associação do desamparo aprendido com a depressão clínica é analisada criticamente, destacando-se a necessidade de maior rigor metodológico e conceitual nos estudos da área.

  15. Ab initio study of isomerism in molecular ions Li2AB+ with 10 valence electrons

    International Nuclear Information System (INIS)

    Charkin, O.P.; Mak-Ki, M.L.; Shlojer, P.R.

    1997-01-01

    Ab initio calculations of surfaces of Li 2 AB + molecular ion potential energy with biatomic anions AB - with 10 valence electrons have been made in the framework of approximations MP2/6-31G 1 /HF/6-31G*+ZPE(HF/6-31G*) and MP4SDTQ/631G*//MP2/6-31G*+ZPE(MP2/6-31G*). Influence of electron correlation on the accuracy of calculations of their structural and vibrational characteristics is studied. The following most favourable structures have been found: linear for Li 2 BO + , Li 2 CN + , and bent one for Li 2 BS + , with cations coordinated at different anion atoms; onium one for AlOLi 2 + , AlSLi 2 + , SiNLi 2 + and SiPLi 2 + with both cations at electronegative atom of anion

  16. Undoing Gender Through Legislation and Schooling: the Case of AB 537 and AB 394 IN California, USA

    Science.gov (United States)

    Knotts, Greg

    2009-11-01

    This article investigates California laws AB 537: The Student Safety and Violence Prevention Act of 2000, and the recently enacted AB 394: Safe Place to Learn Act. Both demand that gender identity and sexual orientation be added to the lexicon of anti-harassment protection in public education. However, despite these progressive measures, schools have an unconscious acceptance of heteronormativity and gendered norms, which undermines both the spirit and language of these laws. This paper examines how California schools can both change standard practices and realise the transformative social change that laws like AB 537 and AB 394 can instigate. I assert that the systemic implementation of these laws, through the adoption, enforcement and evaluation of existing AB 537 Task Force Recommendations, is necessary for their success. My second assertion is that AB 537 and AB 394 have the potential to change and reconstitute gender-based and heteronormative standards at school sites.

  17. Simulation and Robust Contol of Antilock Braking System ABS

    Directory of Open Access Journals (Sweden)

    David Jordan DELICHRISTOV

    2009-06-01

    Full Text Available This paper deals with simulation and robust control of Antilock Braking System ABS. The briefly are described the main parts of ABS hydraulic system and control algorithm of ABS. Hydraulic system described here is BOSCH ABS 5.x series. The goal of ABS system is vehicle stability and vehicle steering response when braking. If during the braking occurred slip at one or more wheels from any reason, ABS evaluates this by “brake slip” controller. At this moment ABS is trying to use maximal limits of adhesion between tire and road. It means that is necessary control the differences between braking torque and friction torque , which reacts to the wheel via friction reaction tire-road surface. This is realized through the solenoid valves, which are controls (triggered by on the base of PID controller described further in chapter 4. Presented concept is more or less standard for most of the existing ABS systems. The issue should be applied concept of robust ABS control algorithm, which is specific for every type of ABS.

  18. Effect of unlabelled monoclonal antibody (MoAb) on biodistribution of /sup 111/Indium labelled (MoAb)

    Energy Technology Data Exchange (ETDEWEB)

    Lamki, L M; Murray, J L; Rosenblum, M G; Patt, Y Z; Babaian, Richard; Unger, M W

    1988-08-01

    We have evaluated immunoscintigraphy in cancer patients using four /sup 111/In-labelled murine monoclonal antibodies (MoAb): 96.5 (anti-P97 of melanoma), ZME-018 (anti-high molecular weight antibody of melanoma), ZCE-025 (anti-CEA for colon cancer) and PAY-276 (anti-prostatic acid phosphatase for prostatic cancer). The effect of increasing the doses of unlabelled MoAb (co-infused with 1 mg labelled MoAb) on the relative body distribution of each labelled MoAb was assessed. Localization in the liver decreased significantly in all cases, with increasing MoAb dose, except for ZME-018. Localization in other organs increased significantly as the liver activity decreased. The spleen activity, however, fell in the case of MoAb ZME-018. Blood-pool activity increased with MoAb dose in all four MoAbs. These findings correlated with the rise in the detection rate of metastases, the plasma half-life, and other pharmacokinetic parameters. However, the dose level at which this correlation occurred varied with each antibody. These data demonstrate the co-infusion of unlabelled MoAb with /sup 111/In-labelled MoAb could alter the organ distribution, pharmacokinetics and tumour uptake in a favourable manner, though the degree to which this occurs depends on the antibody in question.

  19. Biosorption of Acid Blue 290 (AB 290) and Acid Blue 324 (AB 324) dyes on Spirogyra rhizopus

    International Nuclear Information System (INIS)

    Ozer, Ayla; Akkaya, Goenuel; Turabik, Meral

    2006-01-01

    In this study, the biosorption of Acid Blue 290 and Acid Blue 324 on Spirogyra rhizopus, a green algae growing on fresh water, was studied with respect to initial pH, temperature, initial dye concentration and biosorbent concentration. The optimum initial pH and temperature values for AB 290 and AB 324 biosorption were found to be 2.0, 30 deg. C and 3.0, 25 deg. C, respectively. It was observed that the adsorbed AB 290 and AB 324 amounts increased with increasing the initial dye concentration up to 1500 and 750 mg/L, respectively. The Langmuir, Freundlich, Redlich-Peterson and Koble-Corrigan isotherm models were applied to the experimental equilibrium data and the isotherm constants were determined by using Polymath 4.1 software. The monolayer coverage capacities of S. rhizopus for AB 290 and AB 324 dyes were found as 1356.6 mg/g and 367.0 mg/g, respectively. The intraparticle diffusion model and the pseudo-second order kinetic model were applied to the experimental data in order to describe the removal mechanism of these acidic dyes by S. rhizopus. The pseudo-second order kinetic model described very well the biosorption kinetics of AB 290 and AB 324 dyes. Thermodynamic studies showed that the biosorption of AB 290 and AB 324 on S. rhizopus was exothermic in nature

  20. Popular Herbig AE star AB Aur

    International Nuclear Information System (INIS)

    Shevchenko, V.S.

    1987-01-01

    The variability of AB Aur emission line H α , H β , H γ profiles, equivalent widths (EW λ ) and relative intensity have been observed on the photoelectric scanner. During the 20 d observation period EW λ H α ranged from 23.20 to 35.35 A. Mean EW λ H α is 27.25 A, daily average deviation is 3.60 ± 0.07 A. The minimum time of variability is 1 h . The chromospheric lines near-infrared triplet Ca II and KCaII and emission lines H β -H13, P12-P20, 0I 8446.5 A and the variability of other lines have been studied on the photographic and image-tube spectra. The intensity of these lines and EW λ changed 2-4 times during an interval from 1 h to several years. The AB Aur variability nature of emission lines made it possible to assume that the ''deep chromosphere'' is not a centre-symmetrical or axisymmetrical formation but is a conglomerate of different density and speed gas condensations

  1. Ab initio lattice dynamics of metal surfaces

    International Nuclear Information System (INIS)

    Heid, R.; Bohnen, K.-P.

    2003-01-01

    Dynamical properties of atoms on surfaces depend sensitively on their bonding environment and thus provide valuable insight into the local geometry and chemical binding at the boundary of a solid. Density-functional theory provides a unified approach to the calculation of structural and dynamical properties from first principles. Its high accuracy and predictive power for lattice dynamical properties of semiconductor surfaces has been demonstrated in a previous article by Fritsch and Schroeder (Phys. Rep. 309 (1999) 209). In this report, we review the state-of-the-art of these ab initio approaches to surface dynamical properties of metal surfaces. We give a brief introduction to the conceptual framework with focus on recent advances in computational procedures for the ab initio linear-response approach, which have been a prerequisite for an efficient treatment of surface dynamics of noble and transition metals. The discussed applications to clean and adsorbate-covered surfaces demonstrate the high accuracy and reliability of this approach in predicting detailed microscopic properties of the phonon dynamics for a wide range of metallic surfaces

  2. Focused Wind Mass Accretion in Mira AB

    Science.gov (United States)

    Karovska, Margarita; de Val-Borro, M.; Hack, W.; Raymond, J.; Sasselov, D.; Lee, N. P.

    2011-05-01

    At a distance of about only 100pc, Mira AB is the nearest symbiotic system containing an Asymptotic Giant Branch (AGB) star (Mira A), and a compact accreting companion (Mira B) at about 0.5" from Mira A. Symbiotic systems are interacting binaries with a key evolutionary importance as potential progenitors of a fraction of asymmetric Planetary Nebulae, and SN type Ia, cosmological distance indicators. The region of interaction has been studied using high-angular resolution, multiwavelength observations ranging from radio to X-ray wavelengths. Our results, including high-angular resolution Chandra imaging, show a "bridge" between Mira A and Mira B, indicating gravitational focusing of the Mira A wind, whereby components exchange matter directly in addition to the wind accretion. We carried out a study using 2-D hydrodynamical models of focused wind mass accretion to determine the region of wind acceleration and the characteristics of the accretion in Mira AB. We highlight some of our results and discuss the impact on our understanding of accretion processes in symbiotic systems and other detached and semidetached interacting systems.

  3. Quantum phases of AB2 fermionic chains

    International Nuclear Information System (INIS)

    Murcia-Correa, L S; Franco, R; Silva-Valencia, J

    2016-01-01

    A fermionic chain is a one-dimensional system with fermions that interact locally and can jump between sites in the lattice, in particular an AB n chain type, where A and B are sites that exhibit a difference in energy level of Δ and site B is repeated n-times, such that the unit cell has n +1 sites. A limit case of this model, called the ionic Hubbard model (n = 1), has been widely studied due to its interesting physics and applications. In this paper, we study the ground state of an AB 2 chain, which describes the material R 4 [Pt 2 (P 2 O 5 H 2 ) 4 X] · nH 2 O. Specifically, we consider a filling with two electrons per unit cell, and using the density matrix renormalization group method we found that the system exhibits the band insulator and Mott correlated insulator phases, as well as an intermediate phase between them. For couplings of Δ = 2,10 and 20, we estimate the critical points that separate these phases through the structure factor and the energy gap in the sector of charge and spin, finding that the position of the critical point rises as a function of Δ. (paper)

  4. Workshop on automated beam steering and shaping (ABS). Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Lindroos, M [ed.

    1999-09-10

    A workshop on Automated Beam Steering and Shaping (ABS) was held at CERN in December 1998. This was the first workshop dedicated to this subject. The workshop had two major goals: to review the present status of ABS algorithms and systems around the world and to create a worldwide ABS community. These proceedings contain summary reports from all sessions, contributions from several presentations held at the workshop, and a complete set of abstracts for all presentations. (orig.)

  5. Workshop on automated beam steering and shaping (ABS). Proceedings

    International Nuclear Information System (INIS)

    Lindroos, M.

    1999-01-01

    A workshop on Automated Beam Steering and Shaping (ABS) was held at CERN in December 1998. This was the first workshop dedicated to this subject. The workshop had two major goals: to review the present status of ABS algorithms and systems around the world and to create a worldwide ABS community. These proceedings contain summary reports from all sessions, contributions from several presentations held at the workshop, and a complete set of abstracts for all presentations. (orig.)

  6. Ab initio electronic stopping power in materials

    International Nuclear Information System (INIS)

    Shukri, Abdullah-Atef

    2015-01-01

    The average energy loss of an ion per unit path length when it is moving through the matter is named the stopping power. The knowledge of the stopping power is essential for a variety of contemporary applications which depend on the transport of ions in matter, especially ion beam analysis techniques and ion implantation. Most noticeably, the use of proton or heavier ion beams in radiotherapy requires the knowledge of the stopping power. Whereas experimental data are readily available for elemental solids, the data are much more scarce for compounds. The linear response dielectric formalism has been widely used in the past to study the electronic stopping power. In particular, the famous pioneering calculations due to Lindhard evaluate the electronic stopping power of a free electron gas. In this thesis, we develop a fully ab initio scheme based on linear response time-dependent density functional theory to predict the impact parameter averaged quantity named the random electronic stopping power (RESP) of materials without any empirical fitting. The purpose is to be capable of predicting the outcome of experiments without any knowledge of target material besides its crystallographic structure. Our developments have been done within the open source ab initio code named ABINIT, where two approximations are now available: the Random-Phase Approximation (RPA) and the Adiabatic Local Density Approximation (ALDA). Furthermore, a new method named 'extrapolation scheme' have been introduced to overcome the stringent convergence issues we have encountered. These convergence issues have prevented the previous studies in literature from offering a direct comparison to experiment. First of all, we demonstrate the importance of describing the realistic ab initio electronic structure by comparing with the historical Lindhard stopping power evaluation. Whereas the Lindhard stopping power provides a first order description that captures the general features of the

  7. Singularities of Type-Q ABS Equations

    Directory of Open Access Journals (Sweden)

    James Atkinson

    2011-07-01

    Full Text Available The type-Q equations lie on the top level of the hierarchy introduced by Adler, Bobenko and Suris (ABS in their classification of discrete counterparts of KdV-type integrable partial differential equations. We ask what singularities are possible in the solutions of these equations, and examine the relationship between the singularities and the principal integrability feature of multidimensional consistency. These questions are considered in the global setting and therefore extend previous considerations of singularities which have been local. What emerges are some simple geometric criteria that determine the allowed singularities, and the interesting discovery that generically the presence of singularities leads to a breakdown in the global consistency of such systems despite their local consistency property. This failure to be globally consistent is quantified by introducing a natural notion of monodromy for isolated singularities.

  8. ABS, MBS and CDO compared : An empirical analysis

    NARCIS (Netherlands)

    Vink, D.; Thibeault, A.

    2008-01-01

    The capital market in which the asset-backed securities are issued and traded is composed of three main categories: ABS, MBS and CDOs. We were able to examine a total number of 3,951 loans (worth €730.25 billion) of which 1,129 (worth €208.94 billion) have been classified as ABS. MBS issues

  9. ABS, MBS and CDO pricing comparisons : An empirical analysis

    NARCIS (Netherlands)

    Vink, D.; Thibeault, A.

    2008-01-01

    The capital market in which asset-backed securities are issued and traded is composed of three main categories: ABS, MBS and CDOs. The authors examined a total of 3,466 loans (worth €548.51 billion) of which 1,102 (worth €163.90 billion) have been classified as ABS. MBS issues represent 1,782 issues

  10. Polyvalent horse F(Ab`) 2 snake antivenom: Development of ...

    African Journals Online (AJOL)

    F(ab´)2 fragments were further purified by Q-Fast Flow chromatography, concentrated by molecular ultrafiltration and sterilized by filtration through 0.22 m membranes. The resulting F(ab´)2 preparations were rich in intact L and in pieces of H IgG(T) chains, as demonstrated by electrophoresis and Western blot and exhibited ...

  11. 12 CFR Appendixes A-B to Part 41 - [Reserved

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false [Reserved] A Appendixes A-B to Part 41 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY FAIR CREDIT REPORTING Appendixes A-B to Part 41 [Reserved] ...

  12. Report on enrichment work at AB Atomenergi, 1965-1978

    International Nuclear Information System (INIS)

    Maartensson, M.

    1978-11-01

    A review of the Rand D performed at AB Atomenergi (now Studsvik Energiteknik AB) in the field of enrichment during the period 1965-1978. The report also describes the international development, and discusses the possibilities for continued Swedish efforts in this area. (L.E.)

  13. A Case of Laptop Computer-Induced Erythema Ab Igne

    Directory of Open Access Journals (Sweden)

    Nurettin Özgür Doğan

    2014-12-01

    Full Text Available Erythema ab igne, also known as toasted skin syndrome, is a skin reaction characterized by reticulate erythema, brown pigmentation, and telangiectasia. In some cases, epidermal atrophy and scaling are also identified. The condition is usually caused by prolonged exposure to a source of heat or infrared radiation. Here, we report a case of erythema ab igne associated with laptop computer use.

  14. CRY 1AB trangenic cowpea obtained by nodal electroporation ...

    African Journals Online (AJOL)

    Electroporation-mediated genetic transformation was used to introduce Cry 1 Ab insecticidal gene into cowpea. Nodal buds were electroporated in planta with a plasmid carrying the Cry 1Ab and antibiotic resistance npt II genes driven by a 35S CaMV promoter. T1 seeds derived from electroporated branches were selected ...

  15. Pensamento, Teoria e Estudos Latino-americanos

    Directory of Open Access Journals (Sweden)

    Jacques de Novion

    2014-12-01

    Full Text Available RESUMO O presente trabalho configura como artigo inicial do Dossiê Especial – Pensamento, Teoria e Estudos Latino-americanos, organizado conjuntamente por nós, a pedido da Revista de Estudos e Pesquisas sobre as Américas (CEPPAC, do Instituto de Ciências Sociais (ICS, da Universidade de Brasília (UnB. De forma breve, este artigo apresenta a importância alcançada pelo Pensamento, pela Teoria, e, sobre tudo, pelos Estudos Latino-americanos nas últimas décadas. Em seguida, o artigo apresenta os quatorze trabalhos e uma resenha que compõem este Dossiê, resultado da contribuição de diferentes pesquisadores de distintas localidades da região, organizados em três blocos: Ciências Sociais Latino-americanas, Pensamento e Estudos. PALAVRAS CHAVE: Ciências Sociais Latino-americanas; Pensamento Latino-americanos; Teoria Latino-americana; Estudos Latino-americanos. --- RESUMEN El presente trabajo configura como articulo inicial del Dossier Especial – Pensamiento Teoría y Estudios Latinoamericanos, organizado conjuntamente por nosotros, a pedido de la Revista de Estudos e Pesquisas sobre as Américas (CEPPAC, del Instituto de Ciências Sociais (ICS, de la Universidade de Brasília (UnB. De forma breve, este articulo presenta la importancia alcanzada por el Pensamiento, por la Teoría, y, sobre todo, por los Estudios Latinoamericanos en las últimas décadas. En seguida, el articulo presenta los catorce trabajos e una reseña que componen este Dossier, resultado de la contribución de diferentes investigadores de distintas localidades de la región, organizados en tres bloques: Ciencias Sociales Latinoamericanas, Pensamiento y Estudios. PALABRAS CLAVE: Ciencias Sociales Latinoamericanas; Pensamiento Latinoamericano; Teoría Latinoamericana; Estudios Latinoamericanos. --- ABSTRACT This paper is set up as the initial article of this Special Dossier - Thought, Theory and Latin American Studies, which we organized collectively, at the request

  16. EMPREENDEDORISMO E VALORES HUMANOS: UM ESTUDO CONCEITUAL

    Directory of Open Access Journals (Sweden)

    Luciano Vignochi

    2013-09-01

    Full Text Available O objetivo principal deste artigo foi identificar conceitos de valores humanos em publicações científicas sobre empreendedorismo. Não há um único conceito de valores humanos, gerando diversas abordagens e aplicações do termo em estudos sobre empreendedorismo. Para identificar diferenças conceituais e aplicações práticas, optou-se por realizar uma análise de conteúdo em um portfólio de artigos selecionados em bases de dados. O principal critério de seleção das publicações foi aderência ao tema. Os resultados mostram que valores podem ser definidos como: critérios de julgamento da realidade; aspectos abstratos, cognitivos e afetivos ou características determinantes da personalidade e do comportamento de empreendedores. Valores influenciam a sobrevivência do indivíduo, o crescimento do empreendimento e podem nivelar a congruência do empreendedor e seu propósito de empreendimento com os critérios de convivência social. Ainda foram discriminados resultados de estudos aplicados com vistas a destacar evidências de contribuições práticas de pesquisas sobre valores humanos em empreendedorismo. Futuras investigações para aprofundar e replicar as análises realizadas neste estudo podem contribuir com a formação de empreendedores, a realização de diagnóstico empresarial e com avanços para a consolidação um modelo de desenvolvimento de empresas baseado em valores humanos.

  17. Antecedentes do Conflito Intragrupal: Um Estudo Comparativo

    OpenAIRE

    XAVIER, Tércio Antonio de Souza

    2002-01-01

    No campo do comportamento organizacional vem crescendo a importância dos grupos para as organizações, também têm crescido os problemas relacionados à motivação, à coordenação e aos conflitos. Nesse sentido, este estudo visa estudar e entender o conflito intragrupal em situações de trabalho e seus antecedentes na ótica dos funcionários. Buscam-se os prováveis determinantes das diferenças significativas nos graus de conflito de unidades organizacionais, a fim de subsidiar program...

  18. Habilidades auditivas e afasia: um estudo comparativo

    OpenAIRE

    Nascimento, Maria da Soledade Rolim do

    2012-01-01

    A compreensão da informação recebida pela modalidade auditiva é um requisito importante para a efetividade da comunicação, especialmente na linguagem expressiva. Este trabalho teve como objetivo avaliar a relação das habilidades auditivas com o processo de compreensão da linguagem em pacientes com afasia. Trata-se de um estudo descritivo, transversal, comparativo, com 32 sujeitos, distribuídos em dois grupos: Grupo com afasia (n=16) e Grupo controle (n=16). Os indivíduos foram ...

  19. Undoing Gender through Legislation and Schooling: The Case of AB 537 and AB 394 in California, USA

    Science.gov (United States)

    Knotts, Greg

    2009-01-01

    This article investigates California laws AB 537: The Student Safety and Violence Prevention Act of 2000, and the recently enacted AB 394: Safe Place to Learn Act. Both demand that gender identity and sexual orientation be added to the lexicon of anti-harassment protection in public education. However, despite these progressive measures, schools…

  20. Os estudos brasileiros e os 'brazilianists'

    Directory of Open Access Journals (Sweden)

    José Honório Rodrigues

    1976-09-01

    Full Text Available (primeiro parágrafo do artigo Quando, em 1943-1944, estive nos Estados Unidos, estudando e pesquisando, conheci muitas bibliotecas públicas e universitárias, e o grande Arquivo Nacional dos Estados Unidos. Nas Universidades já se ofereciam cursos de estudos latino-americanos, centralizados sobretudo no estudo da língua espanhola, portuguesa em menor escala, estenografía em espanhol, e raras propunham o ensino da literatura comparativa, antropologia, economia, geografia, política e história latino-americana, sempre em conjunto; raríssimas, como a Columbia, ofereciam aulas de história social e econômica do Brasil, e tambem do México e da América Central, e ainda da Argentina, Uruguai e Paraguai. Havia pouca especialização por paises e áreas, e se via predominantemente a América Latina como um bloco uno e uniforme.

  1. Novas tecnologias no estudo de ondas sonoras

    Directory of Open Access Journals (Sweden)

    Marisa Almeida Cavalcante

    2013-10-01

    Full Text Available http://dx.doi.org/10.5007/2175-7941.2013v30n3p579 O presente trabalho propõe a construção de um Tubo de Kundt adaptado às novas tecnologias disponíveis para o ensino de física. Tem como principal objetivo utilizar a placa Arduino em experimentos didáticos envolvendo o estudo de ondas sonoras. O Arduino é uma placa de controle I/O baseada no micro-controlador Atmega (Atmel e foi projetado inicialmente para fins didáticos. O fato da linguagem de programação utilizada e hardware serem do tipo open source (código aberto possibilitou sua ampla difusão em diversas áreas. Uma das intenções deste projeto é difundir o uso deste recurso para fins educacionais e particularmente no estudo de ondas sonoras estacionarias em tubos, contribuindo com a melhora na abordagem deste conteúdo no ensino e aprendizagem de Física.

  2. SdAb heterodimer formation using leucine zippers

    Science.gov (United States)

    Goldman, Ellen R.; Anderson, George P.; Brozozog-Lee, P. Audrey; Zabetakis, Dan

    2013-05-01

    Single domain antibodies (sdAb) are variable domains cloned from camel, llama, or shark heavy chain only antibodies, and are among the smallest known naturally derived antigen binding fragments. SdAb derived from immunized llamas are able to bind antigens with high affinity, and most are capable of refolding after heat or chemical denaturation to bind antigen again. We hypothesized that the ability to produce heterodimeric sdAb would enable reagents with the robust characteristics of component sdAb, but with dramatically improved overall affinity through increased avidity. Previously we had constructed multimeric sdAb by genetically linking sdAb that bind non-overlapping epitopes on the toxin, ricin. In this work we explored a more flexible approach; the construction of multivalent binding reagents using multimerization domains. We expressed anti-ricin sdAb that recognize different epitopes on the toxin as fusions with differently charged leucine zippers. When the initially produced homodimers are mixed the leucine zipper domains will pair to produce heterodimers. We used fluorescence resonance energy transfer to confirm heterodimer formation. Surface plasmon resonance, circular dichroism, enzyme linked immunosorbent assays, and fluid array assays were used to characterize the multimer constructs, and evaluate their utility in toxin detection.

  3. Ab interno trabeculectomy in the adult patient.

    Science.gov (United States)

    SooHoo, Jeffrey R; Seibold, Leonard K; Kahook, Malik Y

    2015-01-01

    Glaucoma is a potentially blinding disease that affects millions of people worldwide. The mainstay of treatment is lowering of intraocular pressure (IOP) through the use of medications, laser and/or incisional surgery. The trabecular meshwork (TM) is thought to be the site of significant resistance to aqueous outflow in open angle glaucoma. Theoretically, an incision through TM or TM removal should decrease this resistance and lead to a significant reduction in IOP. This approach, commonly referred to as goniotomy or trabeculotomy, has been validated in the pediatric population and has been associated with long-term IOP control. In adults, however, removal of TM tissue has been historically associated with more limited and short-lived success. More recent evidence, reveals that even adult patients may benefit significantly from removal of diseased TM tissue and can lead to a significant reduction in IOP that is long-lasting and safe. In this review, we discuss current evidence and techniques for ab interno trabeculectomy using various devices in the adult patient.

  4. Phonocatalysis. An ab initio simulation experiment

    Directory of Open Access Journals (Sweden)

    Kwangnam Kim

    2016-06-01

    Full Text Available Using simulations, we postulate and show that heterocatalysis on large-bandgap semiconductors can be controlled by substrate phonons, i.e., phonocatalysis. With ab initio calculations, including molecular dynamic simulations, the chemisorbed dissociation of XeF6 on h-BN surface leads to formation of XeF4 and two surface F/h-BN bonds. The reaction pathway and energies are evaluated, and the sorption and reaction emitted/absorbed phonons are identified through spectral analysis of the surface atomic motion. Due to large bandgap, the atomic vibration (phonon energy transfer channels dominate and among them is the match between the F/h-BN covalent bond stretching and the optical phonons. We show that the chemisorbed dissociation (the pathway activation ascent requires absorption of large-energy optical phonons. Then using progressively heavier isotopes of B and N atoms, we show that limiting these high-energy optical phonons inhibits the chemisorbed dissociation, i.e., controllable phonocatalysis.

  5. Ab initio derivation of model energy density functionals

    International Nuclear Information System (INIS)

    Dobaczewski, Jacek

    2016-01-01

    I propose a simple and manageable method that allows for deriving coupling constants of model energy density functionals (EDFs) directly from ab initio calculations performed for finite fermion systems. A proof-of-principle application allows for linking properties of finite nuclei, determined by using the nuclear nonlocal Gogny functional, to the coupling constants of the quasilocal Skyrme functional. The method does not rely on properties of infinite fermion systems but on the ab initio calculations in finite systems. It also allows for quantifying merits of different model EDFs in describing the ab initio results. (letter)

  6. [Kidney allotransplantation from the AB0-incompatible donors].

    Science.gov (United States)

    Goriaĭnov, V A; Kaabak, M M; Babenko, N N; Shishlo, L A; Morozova, M M; Ragimov, A A; Dazhkova, N G; Salimov, E L

    2013-01-01

    The experience of 28 kidney allotransplantations from the AB0-incompatible donors was analyzed. The comparative group consisted of 38 patients, who received the AB0-compatible organ. The results were assessed using the following parameters: renal function, morphology of the biopsy samples of the transplanted kidney and actuary survival of the recipients with functioning transplants in both groups. The comparative analysis showed no significant difference between the two groups, giving the right to consider the kidney allotransplantation from the AB0-incompatible donors safe and effective.

  7. Revealing strategies of quorum sensing in Azospirillum brasilense strains Ab-V5 and Ab-V6.

    Science.gov (United States)

    Fukami, Josiane; Abrantes, Julia Laura Fernandes; Del Cerro, Pablo; Nogueira, Marco Antonio; Ollero, Francisco Javier; Megías, Manuel; Hungria, Mariangela

    2018-01-01

    Azospirillum brasilense is an important plant-growth promoting bacterium (PGPB) that requires several critical steps for root colonization, including biofilm and exopolysaccharide (EPS) synthesis and cell motility. In several bacteria these mechanisms are mediated by quorum sensing (QS) systems that regulate the expression of specific genes mediated by the autoinducers N-acyl-homoserine lactones (AHLs). We investigated QS mechanisms in strains Ab-V5 and Ab-V6 of A. brasilense, which are broadly used in commercial inoculants in Brazil. Neither of these strains carries a luxI gene, but there are several luxR solos that might perceive AHL molecules. By adding external AHLs we verified that biofilm and EPS production and cell motility (swimming and swarming) were regulated via QS in Ab-V5, but not in Ab-V6. Differences were observed not only between strains, but also in the specificity of LuxR-type receptors to AHL molecules. However, Ab-V6 was outstanding in indole acetic acid (IAA) synthesis and this molecule might mimic AHL signals. We also applied the quorum quenching (QQ) strategy, obtaining transconjugants of Ab-V5 and Ab-V6 carrying a plasmid with acyl-homoserine lactonase. When maize (Zea mays L.) was inoculated with the wild-type and transconjugant strains, plant growth was decreased with the transconjugant of Ab-V5-confirming the importance of an AHL-mediated QS system-but did not affect plant growth promotion by Ab-V6.

  8. Cutaneous horn and thermal keratosis in erythema AB igne

    Directory of Open Access Journals (Sweden)

    Sood Apra

    2002-01-01

    Full Text Available A 46 - year - old Kashmiri lady developed erythema ab igne on both legs. She subsequently developed multiple keratoses and a cutaneous horn in the involved skin. An uncommon association of these three clinical conditions is being presented.

  9. Energy conservation campaign at Sandvik AB in Sandviken

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Rune

    1979-07-01

    Sandvik AB's performed an analysis showing oil consumption for steam production was increasing considerably. Energy conservation measures were implemented to decrease the oil consumption and to make lasting changes.

  10. Realization of prediction of materials properties by ab initio ...

    Indian Academy of Sciences (India)

    Unknown

    alization of the results of ab initio molecular dynamics simulation on atom insertion process to C60 and to carbon nanotube ... micro-clusters to estimate absolute highest occupied mo- .... To analyse the observed properties theoretically,.

  11. Ab Initio Predictions of Structures and Densities of Energetic Solids

    National Research Council Canada - National Science Library

    Rice, Betsy M; Sorescu, Dan C

    2004-01-01

    We have applied a powerful simulation methodology known as ab initio crystal prediction to assess the ability of a generalized model of CHNO intermolecular interactions to predict accurately crystal...

  12. Ab Initio Atomistic Thermodynamics for Surfaces: A Primer

    National Research Council Canada - National Science Library

    Rogal, Jutta; Reuter, Karsten

    2006-01-01

    .... These techniques are referred to as first-principles (or in latin: ab initio) to indicate that they do not rely on empirical or fitted parameters, which then makes them applicable for a wide range of realistic conditions...

  13. AB toxins: a paradigm switch from deadly to desirable.

    Science.gov (United States)

    Odumosu, Oludare; Nicholas, Dequina; Yano, Hiroshi; Langridge, William

    2010-07-01

    To ensure their survival, a number of bacterial and plant species have evolved a common strategy to capture energy from other biological systems. Being imperfect pathogens, organisms synthesizing multi-subunit AB toxins are responsible for the mortality of millions of people and animals annually. Vaccination against these organisms and their toxins has proved rather ineffective in providing long-term protection from disease. In response to the debilitating effects of AB toxins on epithelial cells of the digestive mucosa, mechanisms underlying toxin immunomodulation of immune responses have become the focus of increasing experimentation. The results of these studies reveal that AB toxins may have a beneficial application as adjuvants for the enhancement of immune protection against infection and autoimmunity. Here, we examine similarities and differences in the structure and function of bacterial and plant AB toxins that underlie their toxicity and their exceptional properties as immunomodulators for stimulating immune responses against infectious disease and for immune suppression of organ-specific autoimmunity.

  14. Diffusion of hydrogen interstitials in Zr based AB2 and mischmetal based AB5 alloys

    International Nuclear Information System (INIS)

    Mani, N; Ravi, N; Ramaprabhu, S

    2005-01-01

    The Zr based AB 2 alloys ZrMnFe 0.5 Ni 0.5 , ZrMnFe 0.5 Co 0.5 and mischmetal (Mm) based AB 5 alloy MmNi 3.5 Al 0.5 Fe 0.5 Co 0.5 have been prepared and characterized by means of powder x-ray diffractograms. The hydrogen absorption kinetics of these alloys have been studied in the temperature and pressure ranges 450-650 0 C and 10-100 mbar respectively with a maximum H to host alloy formula unit ratio of 0.01, using a pressure reduction technique. The diffusion coefficient of the hydrogen interstitials has been determined from hydrogen absorption kinetics experiments. The dependence of the diffusion coefficient on the alloy content has been discussed. For Mm based MmNi 3.5 Al 0.5 Fe 0.5 Co 0.5 alloy, the diffusion coefficient is about an order of magnitude higher than that of the Zr based alloys

  15. Report on the Personnel Dosimetry at AB Atomenergi during 1965

    International Nuclear Information System (INIS)

    Edvardsson, K.A.

    1966-10-01

    This report presents the results of the personnel dosimetry at AB Atomenergi during 1965. No doses exceeding the recommendations of ICRP were reported. For AB Atomenergi the average external total body dose during the year was 60 mrem which corresponds to 89.4 manrem. 31200 gamma films and 5850 neutron films were evaluated. 2067 urine analyses and 692 measurements of body activity were made

  16. Rescue of failed filtering blebs with ab interno trephination.

    Science.gov (United States)

    Shihadeh, Wisam A; Ritch, Robert; Liebmann, Jeffrey M

    2006-06-01

    We evaluated the effectiveness of ab interno automated trephination as a technique for rescuing failed mature filtering blebs. A retrospective chart review of 40 failed blebs of 38 patients who had a posttrephination follow-up period of at least 3 months was done. With success defined as intraocular pressure (IOP) control with other modalities of management. Complications were few. We believe that ab interno trephination is an excellent option for rescuing selected failed filtering blebs.

  17. The 2-alkyl-2H-indazole regioisomers of synthetic cannabinoids AB-CHMINACA, AB-FUBINACA, AB-PINACA, and 5F-AB-PINACA are possible manufacturing impurities with cannabimimetic activities

    OpenAIRE

    Longworth, Mitchell; Banister, Samuel D.; Mack, James B. C.; Glass, Michelle; Connor, Mark; Kassiou, Michael

    2016-01-01

    Indazole-derived synthetic cannabinoids (SCs) featuring an alkyl substituent at the 1-position and l-valinamide at the 3-carboxamide position (e.g., AB-CHMINACA) have been identified by forensic chemists around the world, and are associated with serious adverse health effects. Regioisomerism is possible for indazole SCs, with the 2-alkyl-2H-indazole regioisomer of AB-CHMINACA recently identified in SC products in Japan. It is unknown whether this regiosiomer represents a manufacturing impurit...

  18. Report on the Personnel Dosimetry at AB Atomenergi during 1965

    Energy Technology Data Exchange (ETDEWEB)

    Edvardsson, K A

    1966-10-15

    This report presents the results of the personnel dosimetry at AB Atomenergi during 1965. No doses exceeding the recommendations of ICRP were reported. For AB Atomenergi the average external total body dose during the year was 60 mrem which corresponds to 89.4 manrem. 31200 gamma films and 5850 neutron films were evaluated. 2067 urine analyses and 692 measurements of body activity were made.

  19. AB/sub 5/-catalyzed hydrogen evolution cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Hall, D E; Sawada, T; Shepard, V R; Tsujikawa, Y

    1984-01-01

    The AB/sub 5/ metal compounds are highly efficient hydrogen evolution electrocatalysts in alkaline electrolyte. Three types of AB/sub 5/-catalyzed cathode structures were made, using the hydride-forming AB/sub 5/ compounds in particulate form. Plastic-bonded cathodes containing >90 w/o AB/sub 5/ (finished-weight basis) were the most efficient, giving hydrogen evolution overpotentials (/eta/ /SUB H2/ ) of about 0.05 V at 200 mA cm/sup -2/. However, they tended to swell and shed material during electrolysis. Pressed, sintered cathodes containing 40-70 w/o catalyst in a nickel binder gave /eta/ /SUB H2/ about0.08 V; catalyst retention was excellent. Porous, sintered cathode coatings were made with 30-70 w/o AB/sub 5/ catalyst loadings. Their overpotentials were similar to those of the pressed, sintered cathodes. However, at catalyst loadings below about 40 w/o, high overpotentials characteristic of the nickel binder were observed. The structural and electrochemical properties of the three AB/sub 5/-catalyzed cathodes are discussed.

  20. Ab-initio calculation of electronic structure and optical properties of AB-stacked bilayer α-graphyne

    Science.gov (United States)

    Behzad, Somayeh

    2016-09-01

    Monolayer α-graphyne is a new two-dimensional carbon allotrope with many special features. In this work the electronic properties of AA- and AB-stacked bilayers of this material and then the optical properties are studied, using first principle plane wave method. The electronic spectrum has two Dirac cones for AA stacked bilayer α-graphyne. For AB-stacked bilayer, the interlayer interaction changes the linear bands into parabolic bands. The optical spectra of the most stable AB-stacked bilayer closely resemble to that of the monolayer, except for small shifts of peak positions and increasing of their intensity. For AB-stacked bilayer, a pronounced peak has been found at low energies under the perpendicular polarization. This peak can be clearly ascribed to the transitions at the Dirac point as a result of the small degeneracy lift in the band structure.

  1. Study on Exothermic Oxidation of Acrylonitrile-butadiene-styrene (ABS Resin Powder with Application to ABS Processing Safety

    Directory of Open Access Journals (Sweden)

    Jenq-Renn Chen

    2010-08-01

    Full Text Available Oxidative degradation of commercial grade ABS (Acrylonitrile-butadiene-styrene resin powders was studied by thermal analysis. The instabilities of ABS containing different polybutadiene (PB contents with respect to temperature were studied by Differential Scanning Calorimeter (DSC. Thermograms of isothermal test and dynamic scanning were performed. Three exothermic peaks were observed and related to auto-oxidation, degradation and oxidative decomposition, respectively. Onset temperature of the auto-oxidation was determined to be around 193 °C. However, threshold temperature of oxidation was found to be as low as 140 °C by DSC isothermal testing. Another scan of the powder after degeneration in air showed an onset temperature of 127 °C. Reactive hazards of ABS powders were verified to be the exothermic oxidation of unsaturated PB domains, not the SAN (poly(styrene-acrylonitrile matrix. Heat of oxidation was first determined to be 2,800 ± 40 J per gram of ABS or 4,720 ± 20 J per gram of PB. Thermal hazards of processing ABS powder are assessed by adiabatic temperature rise at process conditions. IR spectroscopy associated with heat of oxidation verified the oxidative mechanism, and these evidences excluded the heat source from the degradation of SAN. A specially prepared powder of ABS without adding anti-oxidant was analyzed by DSC for comparing the exothermic behaviors. Exothermic onset temperatures were determined to be 120 °C and 80 °C by dynamic scanning and isothermal test, respectively. The assessment successfully explained fires and explosions in an ABS powder dryer and an ABS extruder.

  2. ESTUDO PROSPECTIVO SOBRE ENCAPSULAMENTO DE COMPOSTOS BIOATIVOS

    Directory of Open Access Journals (Sweden)

    Larissa Assunção

    2014-12-01

    Full Text Available Com o advento da nanotecnologia, houve o desenvolvimento de técnicas envolvendo processamento, fabricação e aplicação de estruturas, com forma e tamanho controlados, sendo que na indústria de alimentos, estas formulações, tanto na faixa micrométrica como nanométrica, vêm sendo utilizadas com o objetivo de favorecer o produto final. Tendo em vista a importância tecnológica dessa técnica e do grande interesse nacional e internacional, principalmente no ramo da indústria alimentícia, sobre os benefícios do encapsulamento, o presente estudo prospectivo teve como objetivo avaliar o panorama mundial relativo ao tema em questão, correlacionando-o com os documentos de patentes depositados. Para tanto, realizou-se uma pesquisa das patentes na base de dados europeia Espacenet®, utilizando os descritores do tema em estudo associados aos códigos de classificação. As informações encontradas foram compiladas em gráficos e discutidas. Pôde-se observar que o maior número de patentes referiu-se ao código A23L1/00 - alimentos ou produtos alimentícios: a sua preparação ou tratamento e houve um crescimento exponencial em relação ao depósito de patentes nos últimos 10 anos, sendo os Estados Unidos o país líder em número de patentes depositadas (60%. A Firmenich e CIE lidera o ranking com mais patentes depositadas. Em relação à área de atuação, predomina a indústria alimentícia (69%. No que diz respeito ao Brasil, o país aparece com apenas 1 patente detentora desta tecnologia, sendo um número bastante reduzido o que mostra a falta de incentivo neste setor. Diante dos resultados obtidos, concluiu-se que, apesar de ser uma tecnologia recente, observa-se uma tendência ao crescimento de depósito de patentes.

  3. Ab initio study of the isomerism of (LiAB)2 salt dimers with 24 valence electrons (AB- = NO-, PO-, NS-, PS-)

    International Nuclear Information System (INIS)

    Charkin, O.P.; Klimenko, N.M.; MakKi, M.L.

    2000-01-01

    The nonempiric calculations of the potential energies surfaces in the vicinity of the key structures of the loose dimer molecules of the (LiNO) 2 , (LiPO) 2 , (LiNS) 2 and (LiPS) 2 lithium salts with 24 valence electrons are accomplished within the frames of the MP2/6-31G * //HF/6-31g * + ZPE(HF/6-31G * and MP4SDTQ/6-31G * //MP2/6-31G * + ZPE(MP2/6-31G * ) approximation. The equilibrium geometrical parameters, relative energies and isomer decay energies, frequencies and IR-intensities of normal vibrations are determined. The geometrical deformations and shifts of vibrational frequencies of the cis- and trans-dianions under the effect of cations by different ways of their coordination as well as tendencies of the molecular properties behaviour in various series of dimers (LiAB) 2 are analyzed. The results obtained are compared with the data of previous calculations of the LiAB salts monomeric molecules, the Li 2 AB + ions with 12 valence electrons and the (LiAB) 2 dimers with 20 valence electrons [ru

  4. Marketing do mercado de luxo: Estudo de caso Victoria's Secret

    OpenAIRE

    Ana Francisca Giuliani

    2013-01-01

    Este artigo teve por objetivo identificar quais são as estratégias de marketing utilizadas pela empresa varejista Victoria’s Secret para a fidelização do consumidor de luxo em nível global. O estudo caracterizou-se como uma pesquisa qualitativa, utilizando-se como estratégia de campo o estudo de caso de caráter ilustrativo. Para o alcance do objetivo proposto, dividiu-se o estudo em duas fases. Na primeira, denominada exploratória, buscou-se em dados secundários o embasamento para a construçã...

  5. Bibliotecas domiciliares: um estudo de caso

    Directory of Open Access Journals (Sweden)

    Adalberto Rego Maciel Filho

    Full Text Available Pesquisa empírica sobre o papel da biblioteca domiciliar e do hábito de leitura dos pais dos professores da Universidade de Pernambuco, na escolaridade dos educadores. 107 professores foram entrevistados (24 especialistas, 60 mestres, 25 doutores. Constatou-se que a residência na infância dos professores da UPE, na média, teria uma biblioteca domiciliar de 119,7 volumes (no Fundamental I; e seus pais, na maioria, liam e tinham quase 11,1 anos de estudo. Simulações também foram realizadas, analisando as relações entre o tamanho das bibliotecas domiciliares e desempenho escolar com dados do PISA, referentes a 27 países e, no caso do Brasil, com 2000 alunos. Os resultados acompanham as conclusões apresentadas na revisão da literatura, que apontam uma correlação positiva entre as duas variáveis. São sugeridas políticas que poderiam influenciar programas já existentes e novos projetos, ou, ainda, incentivar novas pesquisas na área de bibliotecas domiciliares e públicas.

  6. TITRATION METHOD OF AB0 ANTIBODIES WITH THE USE OF MODERN GEL TECHNOLOGY IN AB0-INCOMPATIBLE TRANSPLANTATION

    Directory of Open Access Journals (Sweden)

    A. K. Porunova

    2014-01-01

    Full Text Available It is shown that developed method of titrating AB0 antibodies allows defi ning the titer of the investigational antibodies more precisely on 1–3 dilution of serum compared to the prototype method (titration method of antibodiesin saline medium on the plane. It is more obvious as it excludes hardly interpretable results due to the possibility of conducting visual assessment of agglutination reaction in the gel card thick column and requires less time foranalysis. The results can be saved for comparison with the results of further research. That is not possible under prototype titration method. Aim: our aim is to create a laboratory technique that can accurately, reliably and clearly produce titration of AB0 system antibodies, including in patients with low initial concentration of agglutinins in the blood; a technique more economical in terms of spending serum and that takes less time.Materials and methods: those modes were empirically chosen which allow titration of AB0 system agglutinins using gel technology based micro typing; to titer group antibodies 1640 serum assays of recipients in AB0-incompatibletransplantation were analyzed.The result of the use of specially developed method in organ transplantation from incompatible blood donors consists in enhancing accuracy, sensitivity of natural, complete and incomplete AB0 system immune antibodies titration, in its clarity, using of blood micro-doses for earlier detection of sensitizing of the patient, which is especially important in Pediatrics. Conclusion: the developed procedure of AB0-antibodies’ titration using modern gel technology makes possible a more precise monitoring of the titer of antibodies that is necessary to predict the graft rejection risk, to select the Protocol of preoperative preparation and postoperative management of patients, to assess the effectiveness of therapy in patients for whom it is diffi cult to fi nd a compatible blood type donor, and for whom today AB

  7. Report on the Personnel Dosimetry at AB Atomenergi during 1964

    International Nuclear Information System (INIS)

    Edvardsson, K.A.; Hagsgaard, S.

    1966-01-01

    This report presents the results of the personnel dosimetry at AB Atomenergi during 1964. No doses exceeding the recommendations of ICRP were reported. The sum of the reported external total body doses during the year was for AB Atomenergi 51.5 manrem which, distributed over the whole company personnel, corresponds to an average dose of about 35 mrem per year and person or less than 1 % of the maximum permissible dose. 31,400 gamma films and 5,800 neutron films were evaluated. The films were changed every month. Urine analyses numbered 2,731 and whole body measurements 485. A comparison is made between dose distributions at AB Atomenergi and at institutions in other countries. The fraction of all personnel carrying dosimeters and exposed to more than a nominal dose seems generally to have been less than 10-20 %

  8. ABS 3D printed solutions for cryogenic applications

    Science.gov (United States)

    Bartolomé, E.; Bozzo, B.; Sevilla, P.; Martínez-Pasarell, O.; Puig, T.; Granados, X.

    2017-03-01

    3D printing has become a common, inexpensive and rapid prototyping technique, enabling the ad hoc fabrication of complex shapes. In this paper, we demonstrate that 3D printed objects in ABS can be used at cryogenic temperatures, offering flexible solutions in different fields. Firstly, a thermo-mechanical characterization of ABS 3D printed specimens at 77 K is reported, which allowed us to delimit the type of cryogenic uses where 3D printed pieces may be implemented. Secondly, we present three different examples where ABS 3D printed objects working at low temperatures have provided specific solutions: (i) SQUID inserts for angular magnetometry (low temperature material characterization field); (ii) a cage support for a metamaterial ;magnetic concentrator; (superconductivity application), and (iii) dedicated tools for cryopreservation in assisted reproductive techniques (medicine field).

  9. Report on the Personnel Dosimetry at AB Atomenergi during 1964

    Energy Technology Data Exchange (ETDEWEB)

    Edvardsson, K A; Hagsgaard, S

    1966-01-15

    This report presents the results of the personnel dosimetry at AB Atomenergi during 1964. No doses exceeding the recommendations of ICRP were reported. The sum of the reported external total body doses during the year was for AB Atomenergi 51.5 manrem which, distributed over the whole company personnel, corresponds to an average dose of about 35 mrem per year and person or less than 1 % of the maximum permissible dose. 31,400 gamma films and 5,800 neutron films were evaluated. The films were changed every month. Urine analyses numbered 2,731 and whole body measurements 485. A comparison is made between dose distributions at AB Atomenergi and at institutions in other countries. The fraction of all personnel carrying dosimeters and exposed to more than a nominal dose seems generally to have been less than 10-20 %.

  10. Valor do estudo citogenetico no transexualismo

    Directory of Open Access Journals (Sweden)

    P. H. Saldanha

    1976-09-01

    Full Text Available O transexualismo é caracterizado como uma entidade psiquiátrica, distinta do homossexualismo e travestismo, revendo-se suas manifestações sindrômicas. Discutem-se as duas principais causas etiológicas plausíveis do transexualismo, a saber: a hipótese psicoanalítica fundamentada na regressão psicossexual com estampagem da figura materna e o modelo neuro-endócrino que pressupõe alterações nos centros de identidade sexual do hipotámo. Com base nesta última explicação propõe-se, a exemplo do que parece ocorrer na síndrome de Morris, cujas células (XY não respondem ao efeito masculinizante da testosterona plasmática, que os transexuais devem possuir mosaicismo detectável ou críptico, quanto aos cromossomos sexuais, nos centros hipotalâmicos de identidade sexual que não respondem à secreção androgênica produzida pela gônada primitiva. Esta possibilidade explicaria a excessiva prevalência da síndrome entre homens, bem como a sua manifestação com feições típicas no sexo masculino e ainda a ocorrência esporádica da síndrome. O estudo citogenético revelou que a frequência (32% de mosaicismo quanto aos cromossomos sexuais em 25 transexuais é estatisticamente superior aos valores observados em 14 homossexuais e 40 controles normais, nos quais a proporção de mosaicismo é praticamente nula. Considera-se a possibilidade do critério cariotípico constituir valioso subsídio na diagnose da síndrome.

  11. Estudos sobre a Esquistosomose em Pernambuco, Brasil

    Directory of Open Access Journals (Sweden)

    Aggeu Magalhães

    1940-01-01

    Full Text Available Os autores referem os resultados dos estudos sobre esquistosomose realisados, em Pernambuco, de Novembro de 1938 a Dezembro de 1939. Não se extendem em discussão, nem comentarios, tampouco, relacionam suas verificações com o que já foi relatado sobre o assunto em trabalhos nacionais e estrangeiros, pelo fato de que, não se trata de um resultado definitivo e sim de atividades que irão proseguir. Os estudos sistematicos em torno da endemia esquistosomica foram executados em duas localidades diversas pela população e pela situação geografica e ecologica. Pontezinha é uma povoação de 1200 habitantes localizada proximo a um conjunto de charcos e lagõas de agua dôce onde pululam caramujos do tipo olivaceus de Spix, e apresenta uma taxa de infestação de 21,4% para individuos do sexo masculino, e de 14,7% para os do sexo feminino. A distribuição por grupos de idade mostra que a incidencia cresce até o grupo de 16 a 20 anos de idade, quando atinge a percentagem de 37,8%, para decrescer em seguida. Em Vitoria a incidencia foi maior nos indivíduos do sexo feminino, atingindo a taxa de 41,4%, dando o sexo masculino a taxa de 36,9%. Por idade a percentagem maxima é atingida pelo grupo de 11 a 15 anos. Vitoria é uma cidade de 1500 habitantes, construida á margem do rio Tapacurá, onde se encontram numerosos caramujos do tipo centimetralis Lutz. A divergencia de incidencia corre por conta dos habitos da população e pela utilização que ela faz do rio, sendo maior em Vitoria porque a proximidade do rio facilita o uso de suas aguas para banho e serviços domesticos, condicionando este ultimo fato, a maior infestação das mulheres. O estudo da frequencia da infestação dos caramujos por cercarias de diversos trematodios, permite suspeitar uma relação inversa entre a taxa de infestação e o diametro maximo atingido pelos caramujos, parecendo este fato confirmar os trabalhos de Vianna Martins sobre a identidade dos hospedeiros

  12. Student Measurements of STFA 10AB (Theta Tauri)

    Science.gov (United States)

    Gillette, Sean; Estrada, Chris; Estrada, Reed; Aguilera, Sophia; Chavez, Valerie; Givens, Jalynn; Lindorfer, Sarah; Michels, Kaylie; Mobley, Makenzie; Reder, Gabriel; Renteria, Kayla; Shattles, Jenna; Wilkin, Aiden; Woodbury, Maisy; Rhoades, Breauna; Rhoades, Mark

    2017-04-01

    Eighth grade students at Vanguard Preparatory School measured the double star STFA 10AB using a 22-inch Newtonian Alt/Az telescope and a Celestron Micro Guide eyepiece. Bellatrix was used as the calibration star. The calculated means of multiple observations of STFA 10AB resulted in a separation of 45.18,” a scale constant of 7.88 arcseconds per division, and position angle of 257.9°. These measurements were compared to the most recent values in the Washington Double Star Catalog.

  13. Report on the Personnel Dosimetry at AB Atomenergi during 1962

    International Nuclear Information System (INIS)

    Edvardsson, K.A.; Hagsgaard, S.

    1963-12-01

    This report presents the results of the personnel dosimetry at AB Atomenergi during 1962. No doses exceeding the recommendations of ICRP have been reported. The sum of the reported external total body doses (≥ 100 mrem/quarter) is for the whole of AB Atomenergi during this year 74. 2 manrem corresponding to about 50 mrem/year and person or 1 % of the maximum permissible dose. 32500 gamma films and 6200 neutron films have been evaluated. The total number of urine analyses is 2700 and of whole body measurements 10

  14. Report on the Personnel Dosimetry at AB Atomenergi during 1962

    Energy Technology Data Exchange (ETDEWEB)

    Edvardsson, K A; Hagsgaard, S

    1964-07-15

    This report presents the results of the personnel dosimetry at AB Atomenergi during 1963. No doses exceeding the recommendations of ICRP have been reported. The sum of the reported external total body doses during the year is for AB Atomenergi 64.2 manrem which, distributed over the whole company personnel, corresponds to about 40 mrem per year and person or about 1 % of the maximum permissible dose. 37800 gamma films and 6700 neutron films have been evaluated. The total number of urine analyses is 3603 and of whole body measurements 211.

  15. Report on the Personnel Dosimetry at AB Atomenergi during 1962

    Energy Technology Data Exchange (ETDEWEB)

    Edvardsson, K A; Hagsgaard, S

    1963-12-15

    This report presents the results of the personnel dosimetry at AB Atomenergi during 1962. No doses exceeding the recommendations of ICRP have been reported. The sum of the reported external total body doses ({>=} 100 mrem/quarter) is for the whole of AB Atomenergi during this year 74. 2 manrem corresponding to about 50 mrem/year and person or 1 % of the maximum permissible dose. 32500 gamma films and 6200 neutron films have been evaluated. The total number of urine analyses is 2700 and of whole body measurements 10.

  16. Use of ab initio quantum chemical methods in battery technology

    Energy Technology Data Exchange (ETDEWEB)

    Deiss, E [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Ab initio quantum chemistry can nowadays predict physical and chemical properties of molecules and solids. An attempt should be made to use this tool more widely for predicting technologically favourable materials. To demonstrate the use of ab initio quantum chemistry in battery technology, the theoretical energy density (energy per volume of active electrode material) and specific energy (energy per mass of active electrode material) of a rechargeable lithium-ion battery consisting of a graphite electrode and a nickel oxide electrode has been calculated with this method. (author) 1 fig., 1 tab., 7 refs.

  17. Ab initio study of isomerism of Li2AB2 molecules and Li2AB2+ ions with 16 valent electrons

    International Nuclear Information System (INIS)

    Charkin, O.P.; Klimenko, N.M.; MakKi, M.L.

    2000-01-01

    In the framework of MP2(6-31*//HF/6-31G + ZPE(HF/6-31G*) and MP4SDTQ/6-31G*//MP2/6-31G* + ZPE(MP2/6-31G*) approximations ab initio calculations of surfaces of potential energy of molecules of lithium salts of Li 2 AB 2 (Li 2 BeO 2 , L 2 MgO 2 , Li 2 BeS 2 , Li 2 MgS 2 , Li 2 CN 2 , Li 2 SiN 2 , Li 2 CP 2 ) type and ions of Li 2 AB 2 + (Li 2 BO 2 + , Li 2 AlO 2 + , Li 2 BS 2 + , Li 2 AlS 2 + , Li 2 N 3 + , Li 2 PN 2 + , Li 2 P 3 + ) type with 16 valent electrons are done. For oxide and nitride systems global minimum corresponds to symmetric linear structure D ∞h and for their sulfide and phosphorus analogues curved plane or unplane (C 2 ) structure with bond angle φ(LBA)=90-110 Deg are preferable. Equilibrium geometric parameters, relative energies and energies of isomer decomposition, frequencies and IR-intensities of normal vibrations are determined [ru

  18. Electronic brakes. From ABS to brake-by-wire. 2. ed.; Elektronische Bremssysteme. Vom ABS zum Brake-by-Wire

    Energy Technology Data Exchange (ETDEWEB)

    Reichel, H.R.

    2003-07-01

    The book reports trends in vehicle brakes from 1968 to 1998. This was the age of the electronic revolution. The book presents conventional brakes, antiblocking systems (ABS), antislip systems (ASS), brake assistants (BAS), dynamic control systems, and brake-by-wire systems. [German] Das Buch berichtet ueber Entwicklungen an Fahrzeugbremsanlagen in der Zeitspanne von 1968 bis etwa 1998. Diese Zeit war gepraegt vom Vordringen der Elektronik in die Bremsen, was fuer Hersteller und Kunden eine Revolution bedeutete. Behandelt sind: (a) Konventionelle Bremsanlagen, (b) Antiblockiersysteme (ABS), (c) Anti-Schlupf-regelungen (ASR), (d) Bremsassistenten (BAS), (e) Fahrdynamikregelungen (FDR, ESP), (f) Brake-by-Wire (orig.)

  19. Estudos organizacionais, (descolonialidade e estudos da dependência: as contribuições da Cepal

    Directory of Open Access Journals (Sweden)

    Sergio Wanderley

    Full Text Available O objetivo deste artigo é (revisitar o conceito de dependência como categoria de investigação da (e a partir da América Latina, por meio de uma perspectiva histórica crítica descolonial, a fim de ampliar o espaço de debates em estudos organizacionais e promover alternativas à ordem neoliberal. Este ensaio terá como foco os estudos da dependência realizados pela Comissão Econômica para a América Latina e o Caribe (Cepal durante a década de 1950 e o início dos anos 1960. A perspectiva descolonial é um constructo teórico de autores latino-americanos que se consideram herdeiros da longa tradição do pensamento social crítico da região, na qual a teoria da dependência está inserida. As propostas dos autores da dependência confrontaram as principais teorias ortodoxas do Norte produzidas à época. A partir do conceito de centro-periferia, da denúncia de assimetrias nas relações entre essas regiões, do reconhecimento da interdependência entre desenvolvimento e subdesenvolvimento, o conceito de dependência foi sendo (reelaborado nas décadas de 1950 e 1960 por diversos autores latino-americanos como uma categoria de investigação da realidade da (e a partir da região. Essas investigações tinham por objetivo não somente elaborar constructos teóricos, mas, também, transformar a realidade por meio da criação de diversas organizações e instituições que deveriam servir ao propósito de superar o subdesenvolvimento. A denúncia da historicidade da situação de subdesenvolvimento desnudou o caráter de neutralidade do economicismo das teorias produzidas no Norte e promoveu um encontro teórico entre economia e política que muito tem a contribuir com a área dos estudos organizacionais.

  20. AB INITIO calculations of magneto-optical effects

    Czech Academy of Sciences Publication Activity Database

    Kuneš, Jan; Oppeneer, P. M.

    2002-01-01

    Roč. 2, - (2002), s. 141-146 ISSN 1346-7948 R&D Projects: GA AV ČR IAA1010214 Institutional research plan: CEZ:AV0Z1010914 Keywords : electronic structure * ab initio calculation * polar magneto-optical Kerr effect * transitiom metal * uranium intermetallics * CrO 2 Subject RIV: BM - Solid Matter Physics ; Magnetism

  1. Monte Carlo simulation of AB-copolymers with saturating bonds

    DEFF Research Database (Denmark)

    Chertovich, A.C.; Ivanov, V.A.; Khokhlov, A.R.

    2003-01-01

    Structural transitions in a single AB-copolymer chain where saturating bonds can be formed between A- and B-units are studied by means of Monte Carlo computer simulations using the bond fluctuation model. Three transitions are found, coil-globule, coil-hairpin and globule-hairpin, depending...

  2. Early stage precipitation in aluminum alloys : An ab initio study

    NARCIS (Netherlands)

    Zhang, X.

    2017-01-01

    Multiscale computational materials science has reached a stage where many complicated phenomena or properties that are of great importance to manufacturing can be predicted or explained. The word “ab initio study” becomes commonplace as the development of density functional theory has enabled the

  3. Ab initio molecular dynamics simulation of laser melting of silicon

    NARCIS (Netherlands)

    Silvestrelli, P.-L.; Alavi, A.; Parrinello, M.; Frenkel, D.

    1996-01-01

    The method of ab initio molecular dynamics, based on finite temperature density functional theory, is used to simulate laser heating of crystal silicon. We have found that a high concentration of excited electrons dramatically weakens the covalent bond. As a result, the system undergoes a melting

  4. STATE OF WORKS ON CREATION ABS FOR PASSENGER CARS

    Directory of Open Access Journals (Sweden)

    E. Getsovich

    2009-01-01

    Full Text Available Numerical modeling of vehicle braking process with ABS are presented. The applicability estimation of control process improvement in dual adaptive control systems is executed. Laboratory experiment results of determining pressure actuator characteristics are published. Piston diameter optimization is provided.

  5. Multiple time step integrators in ab initio molecular dynamics

    International Nuclear Information System (INIS)

    Luehr, Nathan; Martínez, Todd J.; Markland, Thomas E.

    2014-01-01

    Multiple time-scale algorithms exploit the natural separation of time-scales in chemical systems to greatly accelerate the efficiency of molecular dynamics simulations. Although the utility of these methods in systems where the interactions are described by empirical potentials is now well established, their application to ab initio molecular dynamics calculations has been limited by difficulties associated with splitting the ab initio potential into fast and slowly varying components. Here we present two schemes that enable efficient time-scale separation in ab initio calculations: one based on fragment decomposition and the other on range separation of the Coulomb operator in the electronic Hamiltonian. We demonstrate for both water clusters and a solvated hydroxide ion that multiple time-scale molecular dynamics allows for outer time steps of 2.5 fs, which are as large as those obtained when such schemes are applied to empirical potentials, while still allowing for bonds to be broken and reformed throughout the dynamics. This permits computational speedups of up to 4.4x, compared to standard Born-Oppenheimer ab initio molecular dynamics with a 0.5 fs time step, while maintaining the same energy conservation and accuracy

  6. Cyanogen Azide. Ionization Potentials and Ab Initio SCF MO Calculation

    DEFF Research Database (Denmark)

    Bak, Börge; Jansen, Peter; Stafast, Herbert

    1975-01-01

    The Ne(I) and He(I) photoelectron(PE) spectra of cyanogen azide, NCN3, have been recorded at high resolution. Their interpretation is achieved by comparison with the PE spectrum of HN3 and an ab initio LCGO SCF MO calculation. Deviations from Koopmans' theorem of quite different magnitudes...

  7. Ab initio study of alanine polypeptide chain twisting

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Yakubovich, Alexander V.; Solov'yov, Andrey V.

    2006-01-01

    chains. These particular degrees of freedom are essential for the characterization of the proteins folding process. Calculations have been carried out within the ab initio theoretical framework based on the density functional theory and accounting for all the electrons in the system. We have determined...

  8. Ab initio simulation of dislocation cores in metals

    International Nuclear Information System (INIS)

    Ventelon, L.

    2008-01-01

    In the framework of the multi scale simulation of metals and alloys plasticity, the aim of this study is to develop a methodology of ab initio dislocations study and to apply it to the [111] screw dislocation in the bc iron. (A.L.B.)

  9. Young Modulus of Crystalline Polyethylene from ab Initio Molecular Dynamics

    NARCIS (Netherlands)

    Hageman, J.C.L.; Meier, Robert J.; Heinemann, M.; Groot, R.A. de

    1997-01-01

    The Young modulus for crystalline polyethylene is calculated using ab initio molecular dynamics based on density functional theory in the local density approximation (DFT-LDA). This modulus, which can be seen as the ultimate value for the Young modulus of polyethylene fibers, is found to be 334 GPa.

  10. Ab initio electronic properties of dual phosphorus monolayers in silicon

    DEFF Research Database (Denmark)

    Drumm, Daniel W.; Per, Manolo C.; Budi, Akin

    2014-01-01

    In the midst of the epitaxial circuitry revolution in silicon technology, we look ahead to the next paradigm shift: effective use of the third dimension - in particular, its combination with epitaxial technology. We perform ab initio calculations of atomically thin epitaxial bilayers in silicon...

  11. Quantifying transition voltage spectroscopy of molecular junctions: Ab initio calculations

    DEFF Research Database (Denmark)

    Chen, Jingzhe; Markussen, Troels; Thygesen, Kristian Sommer

    2010-01-01

    Transition voltage spectroscopy (TVS) has recently been introduced as a spectroscopic tool for molecular junctions where it offers the possibility to probe molecular level energies at relatively low bias voltages. In this work we perform extensive ab initio calculations of the nonlinear current...

  12. Ab initio study of phase equilibria in TiCx

    DEFF Research Database (Denmark)

    Korzhavyi, P.A.; Pourovskii, L.V.; Hugosson, H.W.

    2002-01-01

    The phase diagram for the vacancy-ordered structures in the substoichiometric TiCx (x = 0.5-1.0) has been established from Monte Carlo simulations with the long-range pair and multisite effective interactions obtained from ab initio calculations. Three ordered superstructures of vacancies (Ti2C, Ti...

  13. Ab initio and kinetic modeling studies of formic acid oxidation

    DEFF Research Database (Denmark)

    Marshall, Paul; Glarborg, Peter

    2015-01-01

    A detailed chemical kinetic model for oxidation of formic acid (HOCHO) in flames has been developed, based on theoretical work and data from literature. Ab initio calculations were used to obtain rate coefficients for reactions of HOCHO with H, O, and HO2. Modeling predictions with the mechanism...

  14. Ab initio calculations and modelling of atomic cluster structure

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Lyalin, Andrey G.; Solov'yov, Andrey V.

    2004-01-01

    The optimized structure and electronic properties of small sodium and magnesium clusters have been investigated using it ab initio theoretical methods based on density-functional theory and post-Hartree-Fock many-body perturbation theory accounting for all electrons in the system. A new theoretical...

  15. AB Toxins: A Paradigm Switch from Deadly to Desirable

    Directory of Open Access Journals (Sweden)

    Oludare Odumosu

    2010-06-01

    Full Text Available To ensure their survival, a number of bacterial and plant species have evolved a common strategy to capture energy from other biological systems. Being imperfect pathogens, organisms synthesizing multi-subunit AB toxins are responsible for the mortality of millions of people and animals annually. Vaccination against these organisms and their toxins has proved rather ineffective in providing long-term protection from disease. In response to the debilitating effects of AB toxins on epithelial cells of the digestive mucosa, mechanisms underlying toxin immunomodulation of immune responses have become the focus of increasing experimentation. The results of these studies reveal that AB toxins may have a beneficial application as adjuvants for the enhancement of immune protection against infection and autoimmunity. Here, we examine similarities and differences in the structure and function of bacterial and plant AB toxins that underlie their toxicity and their exceptional properties as immunomodulators for stimulating immune responses against infectious disease and for immune suppression of organ-specific autoimmunity.

  16. Move of Purchasing Offices TS – AB* – AT*

    CERN Multimedia

    FI Department

    2008-01-01

    The TS – AB* - AT* Purchasing Offices and the Purchasing Pool have moved to Building 5 – 2nd and *3rd floors. The phone and fax numbers are unchanged. We apologize for any inconvenience caused by the move. Thank you for your understanding. Finance Department – Purchasing Service.

  17. EST Table: AB046365 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available 1073 aa FBpp0259641|DyakGE14631-PA 10/08/27 47 %/329 aa W03F8.5#CE34386#WBGene00002247#locus:lam- 1#laminin#...AB046365 10/09/29 97 %/1069 aa dbj|BAB21565.1| laminin [Bombyx mori] 10/08/27 40 %/

  18. Information Manual: Procedures, Planning Concepts, Subsystems. ABS Publication No. 3.

    Science.gov (United States)

    California Univ., Berkeley.

    This report, the third in a series which presents the results of a systems analysis of the problem of providing science and engineering buildings at the university level, is a technical manual for using the Academic Building Systems (ABS) approach in programing, designing, and constructing such facilities. The document presents (1) planning…

  19. Bicanonical ab Initio Molecular Dynamics for Open Systems.

    Science.gov (United States)

    Frenzel, Johannes; Meyer, Bernd; Marx, Dominik

    2017-08-08

    Performing ab initio molecular dynamics simulations of open systems, where the chemical potential rather than the number of both nuclei and electrons is fixed, still is a challenge. Here, drawing on bicanonical sampling ideas introduced two decades ago by Swope and Andersen [ J. Chem. Phys. 1995 , 102 , 2851 - 2863 ] to calculate chemical potentials of liquids and solids, an ab initio simulation technique is devised, which introduces a fictitious dynamics of two superimposed but otherwise independent periodic systems including full electronic structure, such that either the chemical potential or the average fractional particle number of a specific chemical species can be kept constant. As proof of concept, we demonstrate that solvation free energies can be computed from these bicanonical ab initio simulations upon directly superimposing pure bulk water and the respective aqueous solution being the two limiting systems. The method is useful in many circumstances, for instance for studying heterogeneous catalytic processes taking place on surfaces where the chemical potential of reactants rather than their number is controlled and opens a pathway toward ab initio simulations at constant electrochemical potential.

  20. Ab initio calculations of mechanical properties: Methods and applications

    Czech Academy of Sciences Publication Activity Database

    Pokluda, J.; Černý, Miroslav; Šob, Mojmír; Umeno, Y.

    2015-01-01

    Roč. 73, AUG (2015), s. 127-158 ISSN 0079-6425 R&D Projects: GA ČR(CZ) GAP108/12/0311 Institutional support: RVO:68081723 Keywords : Ab initio methods * Elastic moduli * Intrinsic hardness * Stability analysis * Theoretical strength * Intrinsic brittleness/ductility Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 31.083, year: 2015

  1. Further Food for Thought on the "ABS Guide"

    Science.gov (United States)

    Hussain, Simon

    2012-01-01

    This paper replies to points raised by the editors of the "ABS Guide", Huw Morris, Charles Harvey, Aidan Kelly and Michael Rowlinson (2011) "Accounting Education: an international journal", 20(6), pp. 561-573) in response to a paper published in a previous issue of "Accounting Education" (Hussain, S. (2011)…

  2. The Properties of Some Simple Covalent Hydrides: An Ab Initio ...

    African Journals Online (AJOL)

    Some properties of the monomeric binary hydrides of the elements of the first two rows of the periodic table have been determined using ab initio molecular orbital theory. The properties in question are the energetic, structural, electronic, topological and vibrational characteristics. In general, a gradual convergence towards ...

  3. Food for Thought on the "ABS Academic Journal Quality Guide"

    Science.gov (United States)

    Hussain, Simon

    2011-01-01

    This paper discusses issues relating to the use of the Association of Business Schools' (ABS) "Academic Journal Quality Guide" within UK business schools. It also looks at several specific issues raised by the Chair of the British Accounting Association/British Accounting and Finance Association regarding the ratings for top…

  4. Hydrogen Bond Dynamics in Aqueous Solutions: Ab initio Molecular ...

    Indian Academy of Sciences (India)

    Rate equation for the decay of CHB(t) · Definition of Hydrogen Bonds · Results of Molecular Dynamics · Dynamics of anion-water and water-water hydrogen bonds · Structural relaxation of anion-water & water-water H-bonds · Ab initio Molecular Dynamics : · Slide 14 · Dynamics of hydrogen bonds : CPMD results · Slide 16.

  5. Ab initio transport across bismuth selenide surface barriers

    KAUST Repository

    Narayan, Awadhesh; Rungger, Ivan; Droghetti, Andrea; Sanvito, Stefano

    2014-01-01

    © 2014 American Physical Society. We investigate the effect of potential barriers in the form of step edges on the scattering properties of Bi2Se3(111) topological surface states by means of large-scale ab initio transport simulations. Our results

  6. Aceitabilidade de flocos desidratados de abóbora Dehydrated pumpkin flakes acceptability

    Directory of Open Access Journals (Sweden)

    Carmem Lygia Burgos Ambrósio

    2006-02-01

    Full Text Available OBJETIVO: Avaliar a aceitabilidade de flocos desidratados de abóbora, uma vez que tal produto pode constituir uma alternativa no combate à hipovitaminose A. MÉTODOS: Os flocos foram avaliados quanto às características microbiológicas, por meio das análises de coliformes a 45ºC, Escherichia coli, Staphylococcus aureus, Salmonela sp, contagem de bolores e leveduras, e características físico-químicas, por meio da análise de umidade, proteínas, lipídios, cinzas, fibra alimentar, carboidratos, carotenóides, estabilidade ao longo do tempo de armazenamento e aceitabilidade dos flocos adicionados ao feijão e ao pirão de 188 adultos e 67 crianças, respectivamente. RESULTADOS: Os flocos estavam adequados quanto às características microbiológicas e físico-químicas e os percentuais de aceitação de 95,21% para os adultos e 95,52% para as crianças. CONCLUSÃO: Os flocos desidratados de abóbora podem ser utilizados em larga escala para o estudo do efeito deste produto no combate à hipovitaminose A.OBJECTIVE: The objective of this study was to evaluate the acceptability of flakes since this product can be an alternative in the fight against hypovitaminosis A. METHODS: The flakes were evaluated through analyses of coliforms at 45ºC, Escherichia coli, Staphylococcus aureus, Salmonela sp; counting of yeasts and molds; analysis of moisture, proteins, lipids, ash, dietary fibers, carbohydrates and carotenoids; storage stability; and acceptability of flakes added to beans and "pirão" (a widely consumed Brazilian dish consisting of meat and vegetable broth and cassava flour by 188 adults and 67 children. RESULTS: The microbiological and physical-chemical characteristics of the flakes were adequate and the acceptability percentages were 95.21% for adults and 95.52% for children. CONCLUSION: Dehydrated pumpkin flakes can be used in large scale to determine its effectiveness in the fight against hypovitaminosis A.

  7. Unidade de Estudos de Mastites em Pequenos Ruminantes - estudos em ovinos de regime extensivo

    OpenAIRE

    Queiroga, Cristina; Potes, Maria Eduarda; Duarte, Elsa Maria; Marinho, Artur; Bettencourt, Carlos Manuel; Matos, Claudino; Belo, Carlos Carmona; Ribeiro, José Manuel; Vilela, Cristina Lobo

    2007-01-01

    A “Unidade de Estudo de Mastites em Pequenos Ruminantes”, formalmente constituída no âmbito do Programa Nacional de Re-equipamento Científico, da Fundação para a Ciência e a Tecnologia, vem dar corpo ao trabalho de colaboração de diversas equipas de investigação que se têm debruçado sobre a problemática das infecções intramamárias em pequenos ruminantes, nos seus aspectos de saúde animal, saúde pública veterinária e qualidade e segurança alimentar. Tem como principal objectivo criar condições...

  8. Kinesin-2 KIF3AB exhibits novel ATPase characteristics.

    Science.gov (United States)

    Albracht, Clayton D; Rank, Katherine C; Obrzut, Steven; Rayment, Ivan; Gilbert, Susan P

    2014-10-03

    KIF3AB is an N-terminal processive kinesin-2 family member best known for its role in intraflagellar transport. There has been significant interest in KIF3AB in defining the key principles that underlie the processivity of KIF3AB in comparison with homodimeric processive kinesins. To define the ATPase mechanism and coordination of KIF3A and KIF3B stepping, a presteady-state kinetic analysis was pursued. For these studies, a truncated murine KIF3AB was generated. The results presented show that microtubule association was fast at 5.7 μm(-1) s(-1), followed by rate-limiting ADP release at 12.8 s(-1). ATP binding at 7.5 μm(-1) s(-1) was followed by an ATP-promoted isomerization at 84 s(-1) to form the intermediate poised for ATP hydrolysis, which then occurred at 33 s(-1). ATP hydrolysis was required for dissociation of the microtubule·KIF3AB complex, which was observed at 22 s(-1). The dissociation step showed an apparent affinity for ATP that was very weak (K½,ATP at 133 μm). Moreover, the linear fit of the initial ATP concentration dependence of the dissociation kinetics revealed an apparent second-order rate constant at 0.09 μm(-1) s(-1), which is inconsistent with fast ATP binding at 7.5 μm(-1) s(-1) and a Kd ,ATP at 6.1 μm. These results suggest that ATP binding per se cannot account for the apparent weak K½,ATP at 133 μm. The steady-state ATPase Km ,ATP, as well as the dissociation kinetics, reveal an unusual property of KIF3AB that is not yet well understood and also suggests that the mechanochemistry of KIF3AB is tuned somewhat differently from homodimeric processive kinesins. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Perspective: Ab initio force field methods derived from quantum mechanics

    Science.gov (United States)

    Xu, Peng; Guidez, Emilie B.; Bertoni, Colleen; Gordon, Mark S.

    2018-03-01

    It is often desirable to accurately and efficiently model the behavior of large molecular systems in the condensed phase (thousands to tens of thousands of atoms) over long time scales (from nanoseconds to milliseconds). In these cases, ab initio methods are difficult due to the increasing computational cost with the number of electrons. A more computationally attractive alternative is to perform the simulations at the atomic level using a parameterized function to model the electronic energy. Many empirical force fields have been developed for this purpose. However, the functions that are used to model interatomic and intermolecular interactions contain many fitted parameters obtained from selected model systems, and such classical force fields cannot properly simulate important electronic effects. Furthermore, while such force fields are computationally affordable, they are not reliable when applied to systems that differ significantly from those used in their parameterization. They also cannot provide the information necessary to analyze the interactions that occur in the system, making the systematic improvement of the functional forms that are used difficult. Ab initio force field methods aim to combine the merits of both types of methods. The ideal ab initio force fields are built on first principles and require no fitted parameters. Ab initio force field methods surveyed in this perspective are based on fragmentation approaches and intermolecular perturbation theory. This perspective summarizes their theoretical foundation, key components in their formulation, and discusses key aspects of these methods such as accuracy and formal computational cost. The ab initio force fields considered here were developed for different targets, and this perspective also aims to provide a balanced presentation of their strengths and shortcomings. Finally, this perspective suggests some future directions for this actively developing area.

  10. Uma ferramenta para planejamento de estudos para concursos

    Directory of Open Access Journals (Sweden)

    Leonardo Pimentel

    2015-11-01

    Full Text Available De acordo com a constituição brasileira, a única forma de se tornar um empregado do governo é passar em um concurso público. O exame de conhecimento do cargo é um dos componentes mais importantes de um concurso. Estudar para esse exame é uma tarefa que requer planejamento. Um meio de obter um bom planejamento é construir uma grade de horários que relacione as matérias a serem estudadas com os respectivos horários disponíveis para o estudo. Esse tipo de problema se assemelha bastante à gerência de projetos, em que se procura estabelecer a distribuição das atividades ao longo do tempo disponível. Assim, torna-se interessante explorar a dinâmica de estudos para concursos como um projeto. O presente trabalho apresenta a ferramenta de apoio ao estudos - Passe-me, baseada no ciclo PDCA (do inglês, Plan-Do-Check-Act. Por se tratar de uma ferramenta web, o tempo de resposta para produzir uma grade de estudos é fundamental. A ferramenta faz uso de algoritmo genético para calcular a grade de horários priorizando a velocidade de resposta. A ferramenta foi avaliada em diferentes cenários de uso e obteve desempenho satisfatório durante a produção da grade de estudos.

  11. Effect of monoclonal antibodies (MoAb) to class I and class II HLA antigens on lectin- and MoAb OKT3-induced lymphocyte proliferation.

    Science.gov (United States)

    Akiyama, Y; Zicht, R; Ferrone, S; Bonnard, G D; Herberman, R B

    1985-04-01

    We have examined the effect of several monoclonal antibodies (MoAb) to monomorphic determinants of class II HLA antigens, and MoAb to monomorphic determinants of class I HLA antigens and to beta-2-microglobulin (beta 2-mu) on lectin- and MoAb OKT3-induced proliferation of human peripheral blood mononuclear cells (PBMNC) and cultured T cells (CTC). Some, but not all, anti-class II HLA MoAb inhibited the proliferative response of PBMNC to MoAb OKT3 and pokeweed mitogen (PWM). The degree of inhibitory effect varied considerably. This effect was not limited to anti-class II HLA MoAb since anti-class I HLA MoAb and anti-beta 2-mu MoAb also inhibited MoAb OKT3- or PWM-induced proliferative responses. In contrast, the response of PBMNC to phytohemagglutinin (PHA) and concanavalin A (Con A) was not blocked by any anti-class II HLA MoAb. However, some anti-class II HLA MoAb also inhibited the proliferative response of CTC plus allogeneic peripheral blood adherent accessory cells (AC) to PHA or Con A as well as to MoAb OKT3 or PWM. This may be attributable to the substantially greater class II HLA antigen expression by CTC than by fresh lymphocytes. Pretreatment of either CTC or AC with anti-class II HLA MoAb inhibited OKT3-induced proliferation. In contrast, pretreatment of CTC, but not AC, with anti-class I HLA MoAb inhibited the proliferative response of CTC to OKT3. Pretreatment of CTC with anti-class I HLA MoAb inhibited PHA-, Con A and PWM-induced proliferation, to a greater degree than the anti-class II HLA MoAb. It appears as if lymphocyte activation by different mitogens exhibits variable requirements for the presence of cells expressing major histocompatibility determinants. Binding of Ab to membrane markers may interfere with lymphocyte-AC cooperation, perhaps by inhibiting binding of mitogens to their receptors or by interfering with lymphocyte and AC function. We also have examined the role of class II HLA antigens on CTC by depleting class II HLA-positive cells

  12. The melt rheological behavior of AB, ABA, BAB, and (AB)n block copolymers with monodisperse aramide segments

    NARCIS (Netherlands)

    Araichimani, A.; Dullaert, Konraad; Gaymans, R.J.

    2009-01-01

    The melt rheological behavior of segmented block copolymers with high melting diamide (A) hard segments (HS) and polyether (B) soft segments was studied. The block copolymers can be classified as B (monoblock), AB (diblock), ABA (triblock, diamide end segment), BAB (triblock, diamide mid-segment)

  13. Protective mAbs and Cross-Reactive mAbs Raised by Immunization with Engineered Marburg Virus GPs.

    Directory of Open Access Journals (Sweden)

    Marnie L Fusco

    2015-06-01

    Full Text Available The filoviruses, which include the marburg- and ebolaviruses, have caused multiple outbreaks among humans this decade. Antibodies against the filovirus surface glycoprotein (GP have been shown to provide life-saving therapy in nonhuman primates, but such antibodies are generally virus-specific. Many monoclonal antibodies (mAbs have been described against Ebola virus. In contrast, relatively few have been described against Marburg virus. Here we present ten mAbs elicited by immunization of mice using recombinant mucin-deleted GPs from different Marburg virus (MARV strains. Surprisingly, two of the mAbs raised against MARV GP also cross-react with the mucin-deleted GP cores of all tested ebolaviruses (Ebola, Sudan, Bundibugyo, Reston, but these epitopes are masked differently by the mucin-like domains themselves. The most efficacious mAbs in this panel were found to recognize a novel "wing" feature on the GP2 subunit that is unique to Marburg and does not exist in Ebola. Two of these anti-wing antibodies confer 90 and 100% protection, respectively, one hour post-exposure in mice challenged with MARV.

  14. Preparation, biodistribution, and dosimetry of 188Re-Labeled MoAb ior cea1 and its f(ab')2 fragments by avidin-biotin strategy

    International Nuclear Information System (INIS)

    Ferro-Flores, Guillermina; Pimentel-Gonzalez, Gilmara; Gonzalez-Zavala, Maria Antonia; Murphy, Consuelo Arteaga de; Melendez-Alafort, Laura; Tendilla, Jose I.; Croft, Barbara Y.

    1999-01-01

    The biotinylated monoclonal antibody (MoAb) ior cea1 and its F(ab') 2 fragments were labeled with Re-188 by combination of avidin-biotin strategy. 188 Re-MoAb, 188 Re-MoAb-biotin, 188 Re-F(ab') 2 , and 188 Re-F(ab') 2 -biotin preparations were produced for these studies with specific activities of 1.30±0.18 GBq/mg and from instant freeze-dried kit formulations using ethane-1-hydroxy-1,1-diphosphonic acid (EHDP) as a weak competing ligand. There were no significant differences (p>0.05) between the biodistribution in mice of biotinylated and unbiotinylated 188 Re-labeled immunoconjugates. When avidin was injected as a chase after injection of 188 Re-MoAb-biotin or 188 Re-F(ab') 2 -biotin, the blood radioactivity level decreased approximately 75% (cumulated activity) and the effective dose decreased almost 25% with respect to that of the radioimmunoconjugates in which the chase effect was not used. Our results suggest that 188 Re-labeled biotinylated MoAb ior cea1 and its F(ab') 2 fragments prepared by this method are stable complexes in vivo

  15. Development of Anti-lock Braking System (ABS) for Vehicles Braking

    OpenAIRE

    Minh Vu Trieu; Oamen Godwin; Vassiljeva Kristina; Teder Leo

    2016-01-01

    This paper develops a real laboratory of anti-lock braking system (ABS) for vehicle and conducts real experiments to verify the ability of this ABS to prevent the vehicle wheel from being locked while braking. Two controllers of PID and fuzzy logic are tested for analysis and comparison. This ABS laboratory is designed for bachelor and master students to simulate and analyze performances of ABS with different control techniques on various roads and load conditions. Thi...

  16. Speed-up of ab initio hybrid Monte Carlo and ab initio path integral hybrid Monte Carlo simulations by using an auxiliary potential energy surface

    International Nuclear Information System (INIS)

    Nakayama, Akira; Taketsugu, Tetsuya; Shiga, Motoyuki

    2009-01-01

    Efficiency of the ab initio hybrid Monte Carlo and ab initio path integral hybrid Monte Carlo methods is enhanced by employing an auxiliary potential energy surface that is used to update the system configuration via molecular dynamics scheme. As a simple illustration of this method, a dual-level approach is introduced where potential energy gradients are evaluated by computationally less expensive ab initio electronic structure methods. (author)

  17. Standardiserat arbete i produktionssystemet hos Inission Munkfors AB

    OpenAIRE

    Jonas, Arnesson

    2014-01-01

    Sammanfattning Denna rapport behandlar införandet av standardiserat arbete i produktionssystemet hos företaget Inission Munkfors AB. Arbetet har utförts i kursen Examensarbete för högskoleingenjörsexamen i maskinteknik (MSGC17), som ges vid Fakulteten för hälsa, natur & teknikvetenskap på Karlstads universitet.Företaget Inission Munkfors AB har som mål att från år 2012 till år 2017 kunna fördubbla omsättningen och halvera ledtiden, med samma personalstyrka som år 2012 (75st anställda). De...

  18. Computational methods for ab initio detection of microRNAs

    Directory of Open Access Journals (Sweden)

    Malik eYousef

    2012-10-01

    Full Text Available MicroRNAs are small RNA sequences of 18-24 nucleotides in length, which serve as templates to drive post transcriptional gene silencing. The canonical microRNA pathway starts with transcription from DNA and is followed by processing via the Microprocessor complex, yielding a hairpin structure. Which is then exported into the cytosol where it is processed by Dicer and then incorporated into the RNA induced silencing complex. All of these biogenesis steps add to the overall specificity of miRNA production and effect. Unfortunately, their modes of action are just beginning to be elucidated and therefore computational prediction algorithms cannot model the process but are usually forced to employ machine learning approaches. This work focuses on ab initio prediction methods throughout; and therefore homology-based miRNA detection methods are not discussed. Current ab initio prediction algorithms, their ties to data mining, and their prediction accuracy are detailed.

  19. Augmented wave ab initio EFG calculations: some methodological warnings

    International Nuclear Information System (INIS)

    Errico, Leonardo A.; Renteria, Mario; Petrilli, Helena M.

    2007-01-01

    We discuss some accuracy aspects inherent to ab initio electronic structure calculations in the understanding of nuclear quadrupole interactions. We use the projector augmented wave method to study the electric-field gradient (EFG) at both Sn and O sites in the prototype cases SnO and SnO 2 . The term ab initio is used in the standard context of the also called first principles methods in the framework of the Density Functional Theory. As the main contributions of EFG calculations to problems in condensed matter physics are related to structural characterizations on the atomic scale, we discuss the 'state of the art' on theoretical EFG calculations and make a brief critical review on the subject, calling attention to some fundamental theoretical aspects

  20. Augmented wave ab initio EFG calculations: some methodological warnings

    Energy Technology Data Exchange (ETDEWEB)

    Errico, Leonardo A. [Departamento de Fisica-IFLP (CONICET), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC67 (1900) La Plata (Argentina); Renteria, Mario [Departamento de Fisica-IFLP (CONICET), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC67 (1900) La Plata (Argentina); Petrilli, Helena M. [Instituto de Fisica-DFMT, Universidade de Sao Paulo, C.P. 66318, 05315-970 Sao Paulo, SP (Brazil)]. E-mail: hmpetril@macbeth.if.usp.br

    2007-02-01

    We discuss some accuracy aspects inherent to ab initio electronic structure calculations in the understanding of nuclear quadrupole interactions. We use the projector augmented wave method to study the electric-field gradient (EFG) at both Sn and O sites in the prototype cases SnO and SnO{sub 2}. The term ab initio is used in the standard context of the also called first principles methods in the framework of the Density Functional Theory. As the main contributions of EFG calculations to problems in condensed matter physics are related to structural characterizations on the atomic scale, we discuss the 'state of the art' on theoretical EFG calculations and make a brief critical review on the subject, calling attention to some fundamental theoretical aspects.

  1. Preparation and characterization of ABS/anhydrous cobalt chloride composites

    Science.gov (United States)

    Shao, Chengli; Shang, Peng; Mao, Yapeng; Li, Qiuying; Wu, Chifei

    2018-01-01

    Anhydrous cobalt chloride (CoCl2) particles filled acrylonitrile-butadiene-styrene (ABS) composites were successfully prepared and investigated. A strong interfacial interaction between CoCl2 particles and ABS matrix was generated by heat pressing at 190 °C for 15 min. SEM results demonstrated that the particles were dispersed uniformly in the matrix. Fourier transform infrared, x-ray photoelectron spectroscopy and electron spin resonance were used for the investigation of the coordination reaction. The interfacial interaction resulted from a solid-state coordination reaction between nitrile groups (-CN) and cobalt ions (Co2+), leading to an increase in mechanical properties and glass transition temperature. Moreover, heat deflection temperatures were measured and proved to achieve an improvement of 30.6 °C when the CoCl2 content was 7 wt%.

  2. Ultra-Low Voltage Class AB Switched Current Memory Cell

    DEFF Research Database (Denmark)

    Igor, Mucha

    1996-01-01

    This paper presents the theoretical basis for the design of class AB switched current memory cells employing floating-gate MOS transistors, suitable for ultra-low-voltage applications. To support the theoretical assumptions circuits based on these cells were designed using a CMOS process with thr......This paper presents the theoretical basis for the design of class AB switched current memory cells employing floating-gate MOS transistors, suitable for ultra-low-voltage applications. To support the theoretical assumptions circuits based on these cells were designed using a CMOS process...... with threshold voltages of 0.9V. Both hand calculations and PSPICE simulations showed that the cells designed allowed a maximum signal range better than +/-13 micoamp, with a supply voltage down to 1V and a quiescent bias current of 1 microamp, resulting in a very high current efficiency and effective power...

  3. Soliton solutions for ABS lattice equations: I. Cauchy matrix approach

    Science.gov (United States)

    Nijhoff, Frank; Atkinson, James; Hietarinta, Jarmo

    2009-10-01

    In recent years there have been new insights into the integrability of quadrilateral lattice equations, i.e. partial difference equations which are the natural discrete analogues of integrable partial differential equations in 1+1 dimensions. In the scalar (i.e. single-field) case, there now exist classification results by Adler, Bobenko and Suris (ABS) leading to some new examples in addition to the lattice equations 'of KdV type' that were known since the late 1970s and early 1980s. In this paper, we review the construction of soliton solutions for the KdV-type lattice equations and use those results to construct N-soliton solutions for all lattice equations in the ABS list except for the elliptic case of Q4, which is left to a separate treatment.

  4. Ab Initio Calculations Of Light-Ion Reactions

    International Nuclear Information System (INIS)

    Navratil, P.; Quaglioni, S.; Roth, R.; Horiuchi, W.

    2012-01-01

    The exact treatment of nuclei starting from the constituent nucleons and the fundamental interactions among them has been a long-standing goal in nuclear physics. In addition to the complex nature of nuclear forces, one faces the quantum-mechanical many-nucleon problem governed by an interplay between bound and continuum states. In recent years, significant progress has been made in ab initio nuclear structure and reaction calculations based on input from QCD employing Hamiltonians constructed within chiral effective field theory. In this contribution, we present one of such promising techniques capable of describing simultaneously both bound and scattering states in light nuclei. By combining the resonating-group method (RGM) with the ab initio no-core shell model (NCSM), we complement a microscopic cluster approach with the use of realistic interactions and a microscopic and consistent description of the clusters. We discuss applications to light nuclei scattering, radiative capture and fusion reactions.

  5. Social Media Marketing : CASE: OY SUOMEN LYYRA AB

    OpenAIRE

    Eriksson, Irene

    2012-01-01

    This bachelor thesis was commissioned by Oy Suomen Lyyra Ab, the largest student online media and student card producer for higher education students in Finland. The the-sis objective was to understanding the current social media situation and activity among the students of higher education in Finland, the social media networks that the case company currently uses as well as understanding how to use these networks for successful marketing activities. The quantitative research was conducted in...

  6. Report on the Personnel Dosimetry at AB Atomenergi during 1969

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, J; Wahlberg, T

    1971-05-15

    This report presents the results of personnel dosimetry at AB Atomenergi during 1969. 24,200 gamma films and 3,300 neutron films were evaluated. 770 urine analyses and 1,150 measurements of body activity were made. The external total body gamma dose for all employees (quarterly doses < 100 mrem are not reported) corresponds to 136 manrem. The highest external total body gamma dose during 1969 to one person was 4,800 mrem

  7. Report on the Personnel Dosimetry at AB Atomenergi during 1968

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, J; Wahlberg, T

    1969-08-15

    This report presents the results of personnel dosimetry at AB Atomenergi during 1968. 25600 gamma films and 3900 neutron films were evaluated. 1737 urine analyses and 1066 measurements of body activity were made. The external total body gamma dose for all employees (quarterly doses {<=} 100 mrem are not reported) corresponds to 136 manrem. The highest external total body gamma dose during 1968 to one person was 4,500 mrem.

  8. GAUSSIAN 76: an ab initio molecular orbital program

    International Nuclear Information System (INIS)

    Binkley, J.S.; Whiteside, R.; Hariharan, P.C.; Seeger, R.; Hehre, W.J.; Lathan, W.A.; Newton, M.D.; Ditchfield, R.; Pople, J.A.

    Gaussian 76 is a general-purpose computer program for ab initio Hartree-Fock molecular orbital calculations. It can handle basis sets involving s, p and d-type gaussian functions. Certain standard sets (STO-3G, 4-31G, 6-31G*, etc.) are stored internally for easy use. Closed shell (RHF) or unrestricted open shell (UHF) wave functions can be obtained. Facilities are provided for geometry optimization to potential minima and for limited potential surface scans

  9. Report on the Personnel Dosimetry at AB Atomenergi during 1967

    International Nuclear Information System (INIS)

    Carlsson, J.; Wahlberg, T.

    1968-12-01

    This report presents the results of personnel dosimetry at AB Atomenergi during 1967. The external total body gamma dose for all employees (quarterly doses ≤ 100 mrem are not reported) corresponds to 140 manrem. The highest external total body gamma dose during 1967 to one person was 5700 mrem. 24700 gamma films and 3900 neutron films were evaluated. 1988 urine analyses and 989 measurements of body activity were made

  10. Report on the Personnel Dosimetry at AB Atomenergi during 1967

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, J; Wahlberg, T

    1968-12-15

    This report presents the results of personnel dosimetry at AB Atomenergi during 1967. The external total body gamma dose for all employees (quarterly doses {<=} 100 mrem are not reported) corresponds to 140 manrem. The highest external total body gamma dose during 1967 to one person was 5700 mrem. 24700 gamma films and 3900 neutron films were evaluated. 1988 urine analyses and 989 measurements of body activity were made.

  11. Personality at Work: A Study of Type A-B

    Directory of Open Access Journals (Sweden)

    Amber Raza

    2007-10-01

    Full Text Available The objective of this study was to measure the impact of stressors on personality types in Call Centers. Based on literature survey five potential workplace stressors were identified, namely (1 Task Demands, (2 Role Demands, (3 Interpersonal Demands, (4 Organizational Structure and (5 Organizational Leadership. Based on the literature survey, a relationship model was developed that was inclusive of the above stressors, and three personality types, which were Type A, Type AB and Type B.The sample size for the study was 100. The subjects were supervisors and agents drawn non-randomly from various Call Centers of Karachi. All the subjects completed a questionnaire comprised of 27 questions based on occupational stress index (Srivasta and Singh 1981 and AB Personality Continuum (National Institute of Safety and Health 1975. The three personality types A, B & AB all go through stress, however it is the Type A, which thrives on stress. The sources of stress measured in the study were Task Demand, Role Demand, Interpersonal Demands, Organizational Structure and Organizational Leadership.The stressor that most contributed to the Personality type A’s stress in the study was Interpersonal Demand (0.38, which is justified by the literature review as Personality type A are not team players and prefer to work alone.Whereas Personality type B was stressed because of Role Demand (0.38 which is also proved by the literature review as personality type B are laid back and do not take there roles seriously. Hence it can be concluded that it type A tends to cope well with stress as compared to type AB and type B. The performance of the respondents can be made better if the supervisors are aware of the personality types and thereby motivate them according.

  12. Ab initio study of hot electrons in GaAs

    OpenAIRE

    Bernardi, Marco; Vigil-Fowler, Derek; Ong, Chin Shen; Neaton, Jeffrey B.; Louie, Steven G.

    2015-01-01

    Hot carrier dynamics critically impacts the performance of electronic, optoelectronic, photovoltaic, and plasmonic devices. Hot carriers lose energy over nanometer lengths and picosecond timescales and thus are challenging to study experimentally, whereas calculations of hot carrier dynamics are cumbersome and dominated by empirical approaches. In this work, we present ab initio calculations of hot electrons in gallium arsenide (GaAs) using density functional theory and many-body perturbation...

  13. Ab Initio Nuclear Structure and Reaction Calculations for Rare Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Draayer, Jerry P. [Louisiana State Univ., Baton Rouge, LA (United States)

    2014-09-28

    We have developed a novel ab initio symmetry-adapted no-core shell model (SA-NCSM), which has opened the intermediate-mass region for ab initio investigations, thereby providing an opportunity for first-principle symmetry-guided applications to nuclear structure and reactions for nuclear isotopes from the lightest p-shell systems to intermediate-mass nuclei. This includes short-lived proton-rich nuclei on the path of X-ray burst nucleosynthesis and rare neutron-rich isotopes to be produced by the Facility for Rare Isotope Beams (FRIB). We have provided ab initio descriptions of high accuracy for low-lying (including collectivity-driven) states of isotopes of Li, He, Be, C, O, Ne, Mg, Al, and Si, and studied related strong- and weak-interaction driven reactions that are important, in astrophysics, for further understanding stellar evolution, X-ray bursts and triggering of s, p, and rp processes, and in applied physics, for electron and neutrino-nucleus scattering experiments as well as for fusion ignition at the National Ignition Facility (NIF).

  14. Monte Carlo simulation of AB-copolymers with saturating bonds

    CERN Document Server

    Chertovich, A V; Khokhlov, A R; Bohr, J

    2003-01-01

    Structural transitions in a single AB-copolymer chain where saturating bonds can be formed between A-and B-units are studied by means of Monte Carlo computer simulations using the bond fluctuation model. Three transitions are found, coil-globule, coil-hairpin and globule-hairpin, depending on the nature of a particular AB-sequence: statistical random sequence, diblock sequence and 'random-complementary' sequence (one-half of such an AB-sequence is random with Bernoulli statistics while the other half is complementary to the first one). The properties of random-complementary sequences are closer to those of diblock sequences than to the properties of random sequences. The model (although quite rough) is expected to represent some basic features of real RNA molecules, i.e. the formation of secondary structure of RNA due to hydrogen bonding of corresponding bases and stacking interactions of the base pairs in helixes. We introduce the notation of RNA-like copolymers and discuss in what sense the sequences studie...

  15. Ab initio nuclear structure - the large sparse matrix eigenvalue problem

    Energy Technology Data Exchange (ETDEWEB)

    Vary, James P; Maris, Pieter [Department of Physics, Iowa State University, Ames, IA, 50011 (United States); Ng, Esmond; Yang, Chao [Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Sosonkina, Masha, E-mail: jvary@iastate.ed [Scalable Computing Laboratory, Ames Laboratory, Iowa State University, Ames, IA, 50011 (United States)

    2009-07-01

    The structure and reactions of light nuclei represent fundamental and formidable challenges for microscopic theory based on realistic strong interaction potentials. Several ab initio methods have now emerged that provide nearly exact solutions for some nuclear properties. The ab initio no core shell model (NCSM) and the no core full configuration (NCFC) method, frame this quantum many-particle problem as a large sparse matrix eigenvalue problem where one evaluates the Hamiltonian matrix in a basis space consisting of many-fermion Slater determinants and then solves for a set of the lowest eigenvalues and their associated eigenvectors. The resulting eigenvectors are employed to evaluate a set of experimental quantities to test the underlying potential. For fundamental problems of interest, the matrix dimension often exceeds 10{sup 10} and the number of nonzero matrix elements may saturate available storage on present-day leadership class facilities. We survey recent results and advances in solving this large sparse matrix eigenvalue problem. We also outline the challenges that lie ahead for achieving further breakthroughs in fundamental nuclear theory using these ab initio approaches.

  16. Ab initio nuclear structure - the large sparse matrix eigenvalue problem

    International Nuclear Information System (INIS)

    Vary, James P; Maris, Pieter; Ng, Esmond; Yang, Chao; Sosonkina, Masha

    2009-01-01

    The structure and reactions of light nuclei represent fundamental and formidable challenges for microscopic theory based on realistic strong interaction potentials. Several ab initio methods have now emerged that provide nearly exact solutions for some nuclear properties. The ab initio no core shell model (NCSM) and the no core full configuration (NCFC) method, frame this quantum many-particle problem as a large sparse matrix eigenvalue problem where one evaluates the Hamiltonian matrix in a basis space consisting of many-fermion Slater determinants and then solves for a set of the lowest eigenvalues and their associated eigenvectors. The resulting eigenvectors are employed to evaluate a set of experimental quantities to test the underlying potential. For fundamental problems of interest, the matrix dimension often exceeds 10 10 and the number of nonzero matrix elements may saturate available storage on present-day leadership class facilities. We survey recent results and advances in solving this large sparse matrix eigenvalue problem. We also outline the challenges that lie ahead for achieving further breakthroughs in fundamental nuclear theory using these ab initio approaches.

  17. Ab Initio Nuclear Structure and Reaction Calculations for Rare Isotopes

    International Nuclear Information System (INIS)

    Draayer, Jerry P.

    2014-01-01

    We have developed a novel ab initio symmetry-adapted no-core shell model (SA-NCSM), which has opened the intermediate-mass region for ab initio investigations, thereby providing an opportunity for first-principle symmetry-guided applications to nuclear structure and reactions for nuclear isotopes from the lightest p-shell systems to intermediate-mass nuclei. This includes short-lived proton-rich nuclei on the path of X-ray burst nucleosynthesis and rare neutron-rich isotopes to be produced by the Facility for Rare Isotope Beams (FRIB). We have provided ab initio descriptions of high accuracy for low-lying (including collectivity-driven) states of isotopes of Li, He, Be, C, O, Ne, Mg, Al, and Si, and studied related strong- and weak-interaction driven reactions that are important, in astrophysics, for further understanding stellar evolution, X-ray bursts and triggering of s, p, and rp processes, and in applied physics, for electron and neutrino-nucleus scattering experiments as well as for fusion ignition at the National Ignition Facility (NIF).

  18. Ab Initio Calculations of Transport in Titanium and Aluminum Mixtures

    Science.gov (United States)

    Walker, Nicholas; Novak, Brian; Tam, Ka Ming; Moldovan, Dorel; Jarrell, Mark

    In classical molecular dynamics simulations, the self-diffusion and shear viscosity of titanium about the melting point have fallen within the ranges provided by experimental data. However, the experimental data is difficult to collect and has been rather scattered, making it of limited value for the validation of these calculations. By using ab initio molecular dynamics simulations within the density functional theory framework, the classical molecular dynamics data can be validated. The dynamical data from the ab initio molecular dynamics can also be used to calculate new potentials for use in classical molecular dynamics, allowing for more accurate classical dynamics simulations for the liquid phase. For metallic materials such as titanium and aluminum alloys, these calculations are very valuable due to an increasing demand for the knowledge of their thermophysical properties that drive the development of new materials. For example, alongside knowledge of the surface tension, viscosity is an important input for modeling the additive manufacturing process at the continuum level. We are developing calculations of the viscosity along with the self-diffusion for aluminum, titanium, and titanium-aluminum alloys with ab initio molecular dynamics. Supported by the National Science Foundation through cooperative agreement OIA-1541079 and the Louisiana Board of Regents.

  19. Pressure tracking control of vehicle ABS using piezo valve modulator

    Science.gov (United States)

    Jeon, Juncheol; Choi, Seung-Bok

    2011-03-01

    This paper presents a wheel slip control for the ABS(anti-lock brake system) of a passenger vehicle using a controllable piezo valve modulator. The ABS is designed to optimize for braking effectiveness and good steerability. As a first step, the principal design parameters of the piezo valve and pressure modulator are appropriately determined by considering the braking pressure variation during the ABS operation. The proposed piezo valve consists of a flapper, pneumatic circuit and a piezostack actuator. In order to get wide control range of the pressure, the pressure modulator is desired. The modulator consists of a dual-type cylinder filled with different substances (fluid and gas) and a piston rod moving vertical axis to transmit the force. Subsequently, a quarter car wheel slip model is formulated and integrated with the governing equation of the piezo valve modulator. A sliding mode controller to achieve the desired slip rate is then designed and implemented. Braking control performances such as brake pressure and slip rate are evaluated via computer simulations.

  20. Ab initio multiple cloning algorithm for quantum nonadiabatic molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Makhov, Dmitry V.; Shalashilin, Dmitrii V. [Department of Chemistry, University of Leeds, Leeds LS2 9JT (United Kingdom); Glover, William J.; Martinez, Todd J. [Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA and SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States)

    2014-08-07

    We present a new algorithm for ab initio quantum nonadiabatic molecular dynamics that combines the best features of ab initio Multiple Spawning (AIMS) and Multiconfigurational Ehrenfest (MCE) methods. In this new method, ab initio multiple cloning (AIMC), the individual trajectory basis functions (TBFs) follow Ehrenfest equations of motion (as in MCE). However, the basis set is expanded (as in AIMS) when these TBFs become sufficiently mixed, preventing prolonged evolution on an averaged potential energy surface. We refer to the expansion of the basis set as “cloning,” in analogy to the “spawning” procedure in AIMS. This synthesis of AIMS and MCE allows us to leverage the benefits of mean-field evolution during periods of strong nonadiabatic coupling while simultaneously avoiding mean-field artifacts in Ehrenfest dynamics. We explore the use of time-displaced basis sets, “trains,” as a means of expanding the basis set for little cost. We also introduce a new bra-ket averaged Taylor expansion (BAT) to approximate the necessary potential energy and nonadiabatic coupling matrix elements. The BAT approximation avoids the necessity of computing electronic structure information at intermediate points between TBFs, as is usually done in saddle-point approximations used in AIMS. The efficiency of AIMC is demonstrated on the nonradiative decay of the first excited state of ethylene. The AIMC method has been implemented within the AIMS-MOLPRO package, which was extended to include Ehrenfest basis functions.

  1. Studies on the runaway reaction of ABS polymerization process

    International Nuclear Information System (INIS)

    Hu, K.-H.; Kao, C.-S.; Duh, Y.-S.

    2008-01-01

    Taiwan has the largest acrylonitrile-butadiene-styrene (ABS) copolymer production in the world. Preventing on unexpected exothermic reactions and related emergency relief hazard is essential in the safety control of ABS emulsion polymerization. A VSP2 (Vent Sizing Package 2) apparatus is capable of studying both normal and abnormal conditions (e.g., cooling failure, mischarge, etc.) of industrial process. In this study, the scenarios were verified from the following abnormal conditions: loss of cooling, double charge of initiator, overcharge of monomer, without charge of solvent, and external fire. An external fire with constant heating will promote higher self-heat rate and this is recommended as the worst case scenario of emulsion polymerization on butadiene. Cooling failure coupled with bulk system of reactant was determined to be the credible worst case in ABS emulsion polymerization. Finally, the emergency vent sizing based on thermokinetics from VSP associated with DIERS methodology were used for evaluating the vent sizing and compared to that of the industrial plants

  2. Pragmatismo e os pragmáticos nos estudos organizacionais

    Directory of Open Access Journals (Sweden)

    Francis Kanashiro Meneghetti

    Full Text Available O objetivo central deste ensaio teórico é avaliar as contribuições do pragmatismo nos Estudos Organizacionais e, os específicos, avaliar se as contribuições teóricas de Charles Peirce e John Dewey possibilitam afirmar o pragmatismo como senso comum, ciência ou teoria do conhecimento; analisar as contribuições - possibilidadese limites - do pragmatismo como conhecimento científico; compreender os percursos do pragmatismo nos Estudos Organizacionais. Chaga-se a conclusão de que ser pragmático é diferente de conceber estudos articulados no campo epistemológico do pragmatismo. O sujeito pragmático vê na sua utilidade e na necessidade deação, o ponto de tensão que coloca em dúvida a veracidade dos pressupostos do pragmatismo como ciência. O que ocorre nos Estudos Organizacionais éa conversão do pragmatismo como conhecimento científico emsubordinação irracional à utilidade e à ação prática, sobretudo, no campo da economia, da política, da ciência, da cultura, da educação, e assim por diante.

  3. ACREDITAÇÃO HOSPITALAR: UM ESTUDO DE CASO

    Directory of Open Access Journals (Sweden)

    Felipe Antunes

    2005-06-01

    Full Text Available Este artigo aborda a qualidade e acreditação hospitalar através do Manual das Organizações Prestadoras de Serviços Hospitalares, desenvolvido pela Organização Nacional de Acreditação (ONA. O objetivo geral deste trabalho é avaliar o processo de acreditação, identificando dificuldades e benefícios advindos da implantação deste  Manual. Após a realização de uma revisão bibliográfica sobre qualidade em hospitais e normas da qualidade aplicáveis a hospitais, é feita uma análise crítica teórica do Manual das Organizações Prestadoras de Serviços Hospitalares. Tal análise crítica inclui um estudo comparativo entre os requisitos do Manual e da norma NBR ISO 9001/2000. A seguir, a análise teórica é complementada através de um estudo de caso contemplando a implantação do Manual junto a um hospital de grande porte. Finalmente, são apresentadas as conclusões, baseadas tanto no estudo teórico como no estudo prático.

  4. Towards hydrogen metallization: an Ab initio approach; Vers la metallisation de l`hydrogene: approche AB initio

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, St

    1999-12-31

    The quest for metallic hydrogen is a major goal for both theoretical and experimental condensed matter physics. Hydrogen and deuterium have been compressed up to 200 GPa in diamond anvil cells, without any clear evidence for a metallic behaviour. Loubeyere has recently suggested that hydrogen could metallize, at pressures within experimental range, in a new Van der Waals compound: Ar(H{sub 2}){sub 2} which is characterized at ambient pressure by an open and anisotropic sublattice of hydrogen molecules, stabilized by an argon skeleton. This thesis deals with a detailed ab initio investigation, by Car-Parrinello molecular dynamics methods, of the evolution under pressure of this compound. In a last chapter, we go to much higher pressures and temperatures, in order to compare orbital and orbital free ab initio methods for the dense hydrogen plasma. (author) 109 refs.

  5. Towards hydrogen metallization: an Ab initio approach; Vers la metallisation de l`hydrogene: approche AB initio

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, St

    1998-12-31

    The quest for metallic hydrogen is a major goal for both theoretical and experimental condensed matter physics. Hydrogen and deuterium have been compressed up to 200 GPa in diamond anvil cells, without any clear evidence for a metallic behaviour. Loubeyere has recently suggested that hydrogen could metallize, at pressures within experimental range, in a new Van der Waals compound: Ar(H{sub 2}){sub 2} which is characterized at ambient pressure by an open and anisotropic sublattice of hydrogen molecules, stabilized by an argon skeleton. This thesis deals with a detailed ab initio investigation, by Car-Parrinello molecular dynamics methods, of the evolution under pressure of this compound. In a last chapter, we go to much higher pressures and temperatures, in order to compare orbital and orbital free ab initio methods for the dense hydrogen plasma. (author) 109 refs.

  6. Ab initio study of isomerism in molecular Li2AB+ ions with 12 and 14 valence electrons

    International Nuclear Information System (INIS)

    Charkin, O.P.; Klimenko, N.M.; Mak-Ki, M.L.; Shlojer, P.R.

    1997-01-01

    Ab initio calculations of potential energy surfaces (PES) of molecular ions Li 2 AB + with 12 and 14 valence electrons have been made in the framework of approximations MP2/6-31G*//HF/6-31G*+ZPE(HF/6-31G*) and MP4SDTQ/6-31*//MP2/6-31G*+ZPE(MP2/6-31G*). The following most favourable structures have been found: a double-terminal linear for LiNO + (a triplet); a plane bicyclic one for Li 2 OF + , Li 2 SCl + , Li 2 NO + (a singlet) and Li 2 PS + (a singlet), where both cations are coordinated to A-B bond; rectangular (T-shaped) for Li 2 OCl + and SFLi + , as well as for LiNS + and POLi 2 + ions in singlet and triplet states; in the form of a half-opened butterfly for Li 2 PS + (a triplet) and Li 2 SCl +

  7. 40 CFR 174.506 - Bacillus thuringiensis Cry34Ab1 and Cry35Ab1 proteins in corn; exemption from the requirement of...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry34Ab1 and Cry35Ab1 proteins in corn; exemption from the requirement of a tolerance. 174.506 Section 174.506 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS...

  8. HHV-6A/B Integration and the Pathogenesis Associated with the Reactivation of Chromosomally Integrated HHV-6A/B.

    Science.gov (United States)

    Collin, Vanessa; Flamand, Louis

    2017-06-26

    Unlike other human herpesviruses, human herpesvirus 6A and 6B (HHV-6A/B) infection can lead to integration of the viral genome in human chromosomes. When integration occurs in germinal cells, the integrated HHV-6A/B genome can be transmitted to 50% of descendants. Such individuals, carrying one copy of the HHV-6A/B genome in every cell, are referred to as having inherited chromosomally-integrated HHV-6A/B (iciHHV-6) and represent approximately 1% of the world's population. Interestingly, HHV-6A/B integrate their genomes in a specific region of the chromosomes known as telomeres. Telomeres are located at chromosomes' ends and play essential roles in chromosomal stability and the long-term proliferative potential of cells. Considering that the integrated HHV-6A/B genome is mostly intact without any gross rearrangements or deletions, integration is likely used for viral maintenance into host cells. Knowing the roles played by telomeres in cellular homeostasis, viral integration in such structure is not likely to be without consequences. At present, the mechanisms and factors involved in HHV-6A/B integration remain poorly defined. In this review, we detail the potential biological and medical impacts of HHV-6A/B integration as well as the possible chromosomal integration and viral excision processes.

  9. Cooperative effects in spherical spasers: Ab initio analytical model

    Science.gov (United States)

    Bordo, V. G.

    2017-06-01

    A fully analytical semiclassical theory of cooperative optical processes which occur in an ensemble of molecules embedded in a spherical core-shell nanoparticle is developed from first principles. Both the plasmonic Dicke effect and spaser generation are investigated for the designs in which a shell/core contains an arbitrarily large number of active molecules in the vicinity of a metallic core/shell. An essential aspect of the theory is an ab initio account of the feedback from the core/shell boundaries which significantly modifies the molecular dynamics. The theory provides rigorous, albeit simple and physically transparent, criteria for both plasmonic superradiance and surface plasmon generation.

  10. Tailoring magnetoresistance at the atomic level: An ab initio study

    KAUST Repository

    Tao, Kun

    2012-01-05

    The possibility of manipulating the tunneling magnetoresistance (TMR) of antiferromagnetic nanostructures is predicted in the framework of ab initio calculations. By the example of a junction composed of an antiferromagnetic dimer and a spin-polarized scanning tunneling microscopy tip we show that the TMR can be tuned and even reversed in sign by lateral and vertical movements of the tip. Moreover, our finite-bias calculations demonstrate that the magnitude and the sign of the TMR can also be tuned by an external voltage. © 2012 American Physical Society.

  11. Tailoring magnetoresistance at the atomic level: An ab initio study

    KAUST Repository

    Tao, Kun; Stepanyuk, V. S.; Rungger, I.; Sanvito, S.

    2012-01-01

    The possibility of manipulating the tunneling magnetoresistance (TMR) of antiferromagnetic nanostructures is predicted in the framework of ab initio calculations. By the example of a junction composed of an antiferromagnetic dimer and a spin-polarized scanning tunneling microscopy tip we show that the TMR can be tuned and even reversed in sign by lateral and vertical movements of the tip. Moreover, our finite-bias calculations demonstrate that the magnitude and the sign of the TMR can also be tuned by an external voltage. © 2012 American Physical Society.

  12. Computer integrated construction at AB building in reprocessing plant

    International Nuclear Information System (INIS)

    Takami, Masahiro; Azuchi, Takehiro; Sekiguchi, Kenji

    1999-01-01

    JNFL (Japan Nuclear Fuel Limited) is now processing with construction of the spent nuclear fuel reprocessing plant at Rokkasho Village in Aomori Prefecture, which is coming near to the busiest period of construction. Now we are trying to complete the civil work of AB Building and KA Building in a very short construction term by applying CIC (Computer Integrated Construction) concept, in spite of its hard construction conditions, such as the massive and complicated building structure, interferences with M and E (Mechanical and Electrical) work, severe winter weather, remote site location, etc. The key technologies of CIC are three-dimensional CAD, information network, and prefabrication and mechanization of site work. (author)

  13. Ab initio calculations on hydrogen storage in porous carbons

    International Nuclear Information System (INIS)

    Maresca, O.; Marinelli, F.; Pellenq, R.J.M.; Duclaux, L.; Azais, Ph.; Conard, J.

    2005-01-01

    We have investigated through ab initio computations the possible ways to achieve efficient hydrogen storage on carbons. Firstly, we have considered how the curvature of a carbon surface could affect the chemisorption of atomic H 0 Secondly, we show that electron donor elements such as Li and K, used as dopants for the carbon substrate, strongly enhance the physi-sorption energy of H 2 , allowing in principle its storage in this type of material at room temperature under mild conditions of pressure. (authors)

  14. Routine calculation of ab initio melting curves: application to aluminum

    OpenAIRE

    Robert, Grégory; Legrand, Philippe; Arnault, Philippe; Desbiens, Nicolas; Clérouin, Jean

    2014-01-01

    We present a simple, fast, and reliable method to compute the melting curves of materials with ab initio molecular dynamics. It is based on the two-phase thermodynamic model of [Lin et al., J. Chem. Phys. 119, 11792 (2003)] and its improved version given by [Desjarlais, Phys. Rev. E, 88, 062145 (2013)]. In this model, the velocity autocorrelation function is utilized to calculate the contribution of the nuclei motion to the entropy of the solid and liquid phases. It is then possible to find t...

  15. TiAl doping by vanadium: ab initio study

    International Nuclear Information System (INIS)

    Smirnova, E.A.; Isaev, Eh.I.; Vekilov, Yu.Kh.

    2004-01-01

    Tetragonality degree in TiAl and vanadium doping effect on it were studied using the methods of calculation based on approximation of coherent potential and ab initio pseudopotentials. It is shown that vanadium substitution for Ti sublattice atoms entails increase in tetragonality degree but with substitution of the atoms in aluminium sublattice the tetragonality of the TiAl:V alloy decreases and at the content of vanadium about 8 at. % the lattice becomes actually cubical. In its turn, it may result in increase in TiAl ductility, the alloy being brittle at low temperatures [ru

  16. Ab initio calculation of tensile strength in iron

    Czech Academy of Sciences Publication Activity Database

    Friák, Martin; Šob, Mojmír; Vitek, V.

    2003-01-01

    Roč. 83, 31-34 (2003), s. 3529-3537 ISSN 1478-6435. [Multiscale Materials Modelling: Working Theory for Industry /1./. London, 17.06.2002-20.06.2002] R&D Projects: GA AV ČR IAA1041302; GA ČR GA202/03/1351; GA MŠk OC 523.90 Institutional research plan: CEZ:AV0Z2041904 Keywords : ab initio calculations * electronic structure * theoretical tensile strength Subject RIV: BM - Solid Matter Physics ; Magnetism

  17. Ab initio molecular dynamics in a finite homogeneous electric field.

    Science.gov (United States)

    Umari, P; Pasquarello, Alfredo

    2002-10-07

    We treat homogeneous electric fields within density functional calculations with periodic boundary conditions. A nonlocal energy functional depending on the applied field is used within an ab initio molecular dynamics scheme. The reliability of the method is demonstrated in the case of bulk MgO for the Born effective charges, and the high- and low-frequency dielectric constants. We evaluate the static dielectric constant by performing a damped molecular dynamics in an electric field and avoiding the calculation of the dynamical matrix. Application of this method to vitreous silica shows good agreement with experiment and illustrates its potential for systems of large size.

  18. Magnetoband structures of AB-stacked zigzag nanographite ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.P.; Chiu, C.W.; Shyu, F.L.; Chen, R.B.; Lin, M.F

    2002-12-30

    Magnetoband structures of AB-stacked zigzag nanographite ribbons are studied by the tight-binding model. The magnetic field changes band width, energy space, and energy dispersions (the produce of Landau subbands and Landau levels). It causes many zero energy points. Such points and corresponding localized states are studied in detail. There are certain important differences between localized states and edge states. Oscillation period of Landau subbands are determined by these points. The interribbon interactions also affect magnetoband structures, such as energy dispersions, band width, oscillation period of Landau subbands, and flux dependence of Hofstadter butterflies.

  19. Estudo sobre reciclagem de lâmpadas fluorescentes

    OpenAIRE

    Bacila,Danniele Miranda; Fischer,Klaus; Kolicheski,Mônica Beatriz

    2014-01-01

    Lâmpadas fluorescentes (LF) contêm mercúrio em sua composição, um metal pesado que pode causar danos à saúde e ao meio ambiente. As LF são amplamente consumidas no Brasil, porém o descarte correto de LF usadas não é amplamente divulgado e os índices de reciclagem são baixos. O objetivo deste estudo foi demonstrar a relevância do descarte adequado, avaliar as tecnologias de reciclagem e a destinação dos materiais, por meio de estudo comparativo entre Brasil e Alemanha. Através de visitas a rec...

  20. Enfermeiros e clientela com bulimia e anorexia: estudo de caso

    Directory of Open Access Journals (Sweden)

    Claudia Regina Carvalho Martins

    2012-06-01

    Full Text Available Investigação que objetivou identificar a interação de enfermeiros e clientes portadores de bulimia e anorexia. Utilizamos o estudo de caso como recurso, para o qual coletamos dados de prontuários e fizemos entrevistas com oito de quatorze enfermeiros, que foram nossos sujeitos-objeto. De acordo com os enfermeiros, os clientes se isolavam do mundo, vivendo num mundo sem fome e de espelhos que refletiam um corpo sempre acima do "peso ideal"; eram pessoas solitárias, que perderam o brilho pessoal, emitindo sinais de que podiam extinguir a vida deles a qualquer momento. Com o estudo, foi possível identificar a maneira pela qual os enfermeiros interagiam e percebiam os clientes e, em decorrência disso, explicitamos uma prática de cuidar peculiar na enfermagem.

  1. Ana Carolina Escosteguy: Cenários dos estudos culturais

    Directory of Open Access Journals (Sweden)

    Thaisa Cristina Bueno

    2015-12-01

    Full Text Available Autora do livro “Cartografia dos Estudos Culturais”, “Comunicação e recepção” (em coautoria com Nilda Jacks, “Leituras em comunicação, cultura e tecnologia”, além de coautora e organizadora em outras obras de referência sobre o tema cultura e comunicação no Brasil, Ana Carolina Escosteguy é hoje um dos nomes mais importantes quando se pensa em Estudos Culturais no país. Doutora em Ciências da Comunicação pela Universidade de São Paulo (2000, com pós-doutorado no CAMRI (Communication and Media Research Institute, associado ao Department of Journalism and Mass Communication da School of Media, Art and Design da University of Westminster (UK, Ana Carolina Escosteguy é professora titular da Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS e bolsista produtividade em pesquisa do CNPq, desde março 2001. Nesta entrevista ela discute pontos sensíveis da área, entre eles o pouco destaque das pesquisas desse campo têm tido no Jornalismo, o fato de a base teórica ser bem mais ampla que os tradicionais estudos de recepção a que são comumente aproximados, não se nega a tratar das confusões com a folkcomunicação, bem como as próprios limites e intersecções desse campo de estudos. Durante esta conversa, aproveita para apontar as obras que considera essenciais para adentrar na área e mostra coragem e segurança para se colocar como uma pesquisadora que busca entender o tempo atual, as tecnologias e as rupturas a partir da perspectiva do usuário. Confiram:

  2. Frequência dos antígenos eritrocitários do sistema AB em felinos domésticos no estado da Paraíba

    Directory of Open Access Journals (Sweden)

    Rodrigo de S. Mendes

    2013-06-01

    Full Text Available Objetivou-se com este estudo determinar a frequência de antígenos eritrocitários do sistema AB em felinos domésticos da Paraíba, Brasil. Foram selecionados aleatoriamente 178 gatos, clinicamente saudáveis, sem pré-requisitos quanto a sexo ou raça, com peso corporal acima de 1,5 kg e faixa etária acima de um ano de idade, abordados no ato da consulta ambulatorial em clínicas médicas de pequenos animais distribuídas entre três cidades da Paraíba (João Pessoa, Campina Grande e Patos. A determinação dos tipos sanguíneos foi realizada através do teste de hemaglutinação em tubo de ensaio e, a tipagem reversa foi realizada para as amostras tipos B e AB para confirmação e evidenciação de aloanticorpos naturais. Neste estudo a frequência relativa de antígenos eritrocitários A, B e AB em sua totalidade para felinos sem raça foram 98,1%, 1,21% e 0,69%, respectivamente. Todos os felinos com definição racial foram do tipo sanguíneo A. Diante destes, a probabilidade de ocorrência de reações transfusionais aleatórias obtidas foi de 2,78%, sendo cerca 40% (1,11% potencialmente fatais. Desta forma, dado o conhecimento da frequência dos diferentes tipos sanguíneos em felinos, de uma determinada região, conclui-se que a tipagem sanguínea e o teste de compatibilidade, são importantes ferramentas que permitem ao médico veterinário tomar medidas preventivas que minimizem riscos de ocorrência de reações transfusionais e isoeletrólise neonatal e, estabelece pré-requisitos a respeito dos riscos de procedimentos hemoterápicos em felinos que circunstancialmente necessitem serem conduzidos de forma aleatória.

  3. Marketing do mercado de luxo: Estudo de caso Victoria's Secret

    Directory of Open Access Journals (Sweden)

    Ana Francisca Giuliani

    2013-12-01

    Full Text Available Este artigo teve por objetivo identificar quais são as estratégias de marketing utilizadas pela empresa varejista Victoria’s Secret para a fidelização do consumidor de luxo em nível global. O estudo caracterizou-se como uma pesquisa qualitativa, utilizando-se como estratégia de campo o estudo de caso de caráter ilustrativo. Para o alcance do objetivo proposto, dividiu-se o estudo em duas fases. Na primeira, denominada exploratória, buscou-se em dados secundários o embasamento para a construção do referencial teórico. Na segunda, adotou-se a técnica de pesquisa por observação, utilizando-se os sites da Victoria’s Secret, e analisou-se o composto de marketing aplicado ao mercado de luxo com base no modelo proposto por Nahás (2009. Concluiu-se que as estratégias da referida empresa se baseiam no luxo acessível, de modo que, além de conquistar o consumidor, a Victoria’s Secret consegue manter sua fidelidade por apresentar estratégias de forte apelo emocional.

  4. A sociologia funcionalista nos estudos organizacionais: foco em Durkheim

    Directory of Open Access Journals (Sweden)

    Augusto Cabral

    Full Text Available O tema que estrutura este ensaio é o da sociologia funcionalista, particularmente em termos de sua influência nos estudos organizacionais. O seu foco de análise é duplo. Em um primeiro momento, as obras de Durkheim. Em um segundo momento, o impacto e a supremacia dos enfoques funcionalistas nos estudos organizacionais. Embora seus segmentos estejam inter-relacionados, ele é composto de quatro partes. Na primeira, é feita uma análise histórica da emergência e sistematização das ciências sociais, de modo a traçar sua evolução até o surgimento dos trabalhos de Durkheim. Na segunda, tomando como referencial a obra de Burrell e Morgan (1979, é estudado o paradigma funcionalista em termos de sua origem e expoentes, com destaque para Comte e Spencer, visando chegar a uma compreensão inicial do pensamento de Durkheim e de sua sociologia. Na terceira, a vida e as principais obras de Durkheim são sumariadas e discutidas. Por fim, o status atual dos estudos organizacionais -vistos como um conjunto impreciso, elástico e eclético de teorias e pesquisas sociais voltados para os problemas das organizações -é analisado em termos de seus pressupostos epistemológicos e ontológicos subjacentes, como meio de explicitar a supremacia dos enfoques positivistas-funcionalistas.

  5. Equations of state of heavy metals: ab initio approaches; Equations d'etat des metaux lourds: approches ab initio

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, S.; Jollet, F.; Jomard, G.; Siberchicot, B.; Torrent, M.; Zerah, G.; Amadon, B.; Bouchet, J.; Richard, N.; Robert, G. [CEA Bruyeres-le-Chatel, 91 (France)

    2005-07-01

    The determination of equations of states of heavy metals through ab initio calculation, i.e. without any adjustable parameter, allows to access to pressure and temperature thermodynamic conditions sometimes inaccessible to experiment. To perform such calculations, density functional theory (DFT) is a good starting point: when electronic densities are homogeneous enough, the local density approximation (LDA) remarkably accounts for thermodynamic properties of heavy metals, such as tantalum, or the light actinides, as well for static properties - equilibrium volume, elastic constants - as for dynamical quantities like phonon spectra. For heavier elements, like neptunium or plutonium, relativistic effects and strong electronic interactions must be taken into account, which requires more sophisticated theoretical approaches. (authors)

  6. Improved radioimaging and tumor localization with monoclonal F(ab')2

    International Nuclear Information System (INIS)

    Wahl, R.L.; Parker, C.W.; Philpott, G.W.

    1983-01-01

    Monoclonal anti-tumor antibodies have great promise for radioimmunodetection and localization of tumors. Fab and F(ab')2 fragments, which lack the Fc fragment of antibody (Ab), are cleared more rapidly from the circulation and may have less nonspecific tissue binding than intact Ab. In radioimaging studies using a murine monoclonal antibody to carcinoembryonic antigen in a human colon carcinoma xenografted into hamsters, F(ab')2 fragments were shown superior to Fab fragments and intact antibody for scintiscanning. In double-label experiments with anti-CEA antibody and control monoclonal IgG, F(ab')2 fragments were found to give better and more rapid specific tumor localization than intact antibody or Fab fragments. F(ab')2 fragments offer significant promise for tumor imaging and possibly therapy

  7. Pengaruh bahan pengisi serat kaca terhadap sifat fisik dan kristalinitas polipaduan PC/ABS

    Directory of Open Access Journals (Sweden)

    Dwi Wahini Nurhajati

    2017-06-01

    Full Text Available This research aimed to determine the effects of the addition of glass fibers on the physical and crystallinity properties of PC/ABS polyblends. The ratio of PC/ABS used in this research was 75/25, while the addition of glass fibers ranged from 0; 5; 10; to 15 phr (based on the weight of PC/ABS. Polyblends of PC/ABS/glass fibers were prepared in a twin screw extruder. The test results showed that density and tensile strength of PC/ABS polyblends increased with an increase in the glass fiber content. The presence of glass fibers decreased MFI and impact strength of these PC/ABS polyblends. The functional groups were determined by the fourier transform infrared (FTIR spectrophotometer while crystallinity was examined using X-ray diffractometer (XRD.

  8. Microhook ab interno trabeculotomy, a novel minimally invasive glaucoma surgery

    Directory of Open Access Journals (Sweden)

    Tanito M

    2017-12-01

    Full Text Available Masaki Tanito Division of Ophthalmology, Matsue Red Cross Hospital, Matsue, Japan Abstract: Trabeculotomy (LOT is performed to reduce the intraocular pressure in patients with glaucoma, both in children and adults. It relieves the resistance to aqueous flow by cleaving the trabecular meshwork and the inner walls of Schlemm’s canal. Microhook ab interno LOT (µLOT, a novel minimally invasive glaucoma surgery, incises trabecular meshwork using small hooks that are inserted through corneal side ports. An initial case series reported that both µLOT alone and combination of µLOT and cataract surgery normalize the intraocular pressure during the early postoperative period in Japanese patients with glaucoma. Microhook can incise the inner wall of Schlemm’s canal without damaging its outer wall easier than the regular straight knife that is used during goniotomy. Advantages of µLOT include: a wider extent of LOT (two-thirds of the circumference, a simpler surgical technique, being less invasiveness to the ocular surface, a shorter surgical time than traditional ab externo LOT, and no requirement for expensive devices. In this paper, the surgical technique of µLOT and tips of the technique are introduced. Keywords: trabecular meshwork, Schlemm’s canal, intraocular pressure, surgical procedure, glaucoma

  9. Ab initio theory and calculations of X-ray spectra

    International Nuclear Information System (INIS)

    Rehr, J.J.; Kas, J.J.; Prange, M.P.; Sorini, A.P.; Takimoto, Y.; Vila, F.

    2009-01-01

    There has been dramatic progress in recent years both in the calculation and interpretation of various x-ray spectroscopies. However, current theoretical calculations often use a number of simplified models to account for many-body effects, in lieu of first principles calculations. In an effort to overcome these limitations we describe in this article a number of recent advances in theory and in theoretical codes which offer the prospect of parameter free calculations that include the dominant many-body effects. These advances are based on ab initio calculations of the dielectric and vibrational response of a system. Calculations of the dielectric function over a broad spectrum yield system dependent self-energies and mean-free paths, as well as intrinsic losses due to multielectron excitations. Calculations of the dynamical matrix yield vibrational damping in terms of multiple-scattering Debye-Waller factors. Our ab initio methods for determining these many-body effects have led to new, improved, and broadly applicable x-ray and electron spectroscopy codes. (authors)

  10. Step growth of an AB2 monomer, with cycle formation

    DEFF Research Database (Denmark)

    Cameron, Colin; Fawcett, Allan H.; Hetherington, Cecil R.

    1998-01-01

    A computer-based lattice model of the step growth reaction of an AB2 monomer, the next elaborate system after an AB monomer, has been devised that allows the simultaneous and explicit occurrence of inter- and intramolecular reactions of A and B groups of the flexible and moving molecules according...... with fractal characteristics. Growth stops when each molecule contains a cycle. For the model explored, in which six lattice sites are used for each monomer, the limiting value of the number average degree of polymerization, 〈x〉n,∞, is 14.6(±0.3) (after infinite time). The occurrence within the system of rings...... of m residues (m=1,2,3,...) is found to depend upon m and the extent of reaction of the A groups, pa, according to Rm=C0pm am-2.71, the constant C0 reflecting the structure of the lattice and the monomer, and being shown to determine the final degree of polymerization. The exponent of the integers m...

  11. (4)He Thermophysical Properties: New Ab Initio Calculations.

    Science.gov (United States)

    Hurly, John J; Mehl, James B

    2007-01-01

    Since 2000, atomic physicists have reduced the uncertainty of the helium-helium "ab initio" potential; for example, from approximately 0.6 % to 0.1 % at 4 bohr, and from 0.8 % to 0.1 % at 5.6 bohr. These results led us to: (1) construct a new inter-atomic potential ϕ 07, (2) recalculate values of the second virial coefficient, the viscosity, and the thermal conductivity of (4)He from 1 K to 10,000 K, and (3), analyze the uncertainties of the thermophysical properties that propagate from the uncertainty of ϕ 07 and from the Born-Oppenheimer approximation of the electron-nucleon quantum mechanical system. We correct minor errors in a previous publication [J. J. Hurly and M. R. Moldover, J. Res. Nat. Inst. Standards Technol. 105, 667 (2000)] and compare our results with selected data published after 2000. The ab initio results tabulated here can serve as standards for the measurement of thermophysical properties.

  12. 4He Thermophysical Properties: New Ab Initio Calculations

    Science.gov (United States)

    Hurly, John J.; Mehl, James B.

    2007-01-01

    Since 2000, atomic physicists have reduced the uncertainty of the helium-helium “ab initio” potential; for example, from approximately 0.6 % to 0.1 % at 4 bohr, and from 0.8 % to 0.1 % at 5.6 bohr. These results led us to: (1) construct a new inter-atomic potential ϕ07, (2) recalculate values of the second virial coefficient, the viscosity, and the thermal conductivity of 4He from 1 K to 10,000 K, and (3), analyze the uncertainties of the thermophysical properties that propagate from the uncertainty of ϕ07 and from the Born-Oppenheimer approximation of the electron-nucleon quantum mechanical system. We correct minor errors in a previous publication [J. J. Hurly and M. R. Moldover, J. Res. Nat. Inst. Standards Technol. 105, 667 (2000)] and compare our results with selected data published after 2000. The ab initio results tabulated here can serve as standards for the measurement of thermophysical properties. PMID:27110456

  13. Ab initio thermodynamic model for magnesium carbonates and hydrates.

    Science.gov (United States)

    Chaka, Anne M; Felmy, Andrew R

    2014-09-04

    An ab initio thermodynamic framework for predicting properties of hydrated magnesium carbonate minerals has been developed using density-functional theory linked to macroscopic thermodynamics through the experimental chemical potentials for MgO, water, and CO2. Including semiempirical dispersion via the Grimme method and small corrections to the generalized gradient approximation of Perdew, Burke, and Ernzerhof for the heat of formation yields a model with quantitative agreement for the benchmark minerals brucite, magnesite, nesquehonite, and hydromagnesite. The model shows how small differences in experimental conditions determine whether nesquehonite, hydromagnesite, or magnesite is the result of laboratory synthesis from carbonation of brucite, and what transformations are expected to occur on geological time scales. Because of the reliance on parameter-free first-principles methods, the model is reliably extensible to experimental conditions not readily accessible to experiment and to any mineral composition for which the structure is known or can be hypothesized, including structures containing defects, substitutions, or transitional structures during solid state transformations induced by temperature changes or processes such as water, CO2, or O2 diffusion. Demonstrated applications of the ab initio thermodynamic framework include an independent means to evaluate differences in thermodynamic data for lansfordite, predicting the properties of Mg analogues of Ca-based hydrated carbonates monohydrocalcite and ikaite, which have not been observed in nature, and an estimation of the thermodynamics of barringtonite from the stoichiometry and a single experimental observation.

  14. The combined benefits of motorcycle antilock braking systems (ABS) in preventing crashes and reducing crash severity.

    Science.gov (United States)

    Rizzi, Matteo; Kullgren, Anders; Tingvall, Claes

    2016-01-01

    Several studies have reported the benefits of motorcycle antilock braking systems (ABS) in reducing injury crashes, due to improved stability and braking performance. Both aspects may prevent crashes but may also reduce the crash severity when a collision occurs. However, it is still unknown to what extent the reductions in injury crashes with ABS may be due to a combination of these mechanisms. Swedish hospital and police reports (2003-2012) were used. The risk for permanent medical impairment (RPMI) was calculated, showing the risk of at least 1 or 10% permanent medical impairment. In total, 165 crashes involving ABS-equipped motorcycles were compared with 500 crashes with similar motorcycles without ABS. The analysis was performed in 3 steps. First, the reduction in emergency care visits with ABS was calculated using an induced exposure approach. Secondly, the injury mitigating effects of ABS were investigated. The mean RPMI 1+ and RPMI 10+ were analyzed for different crash types. The distributions of impairing injuries (PMI 1+) and severely impairing injuries (PMI 10+) were also analyzed. In the third step, the total reduction of PMI 1+ and PMI 10+ injured motorcyclists was calculated by combining the reductions found in the previous steps. An additional analysis of combined braking systems (CBS) together with ABS was also performed. The results showed that emergency care visits were reduced by 47% with ABS. In the second step, it was found that the mean RPMI 1+ and RPMI 10+ with ABS were 15 and 37% lower, respectively. Finally, the third step showed that the total reductions in terms of crash avoidance and mitigation of PMI 1+ and PMI 10+ injured motorcyclists with ABS were 67 and 55%, respectively. However, PMI 1+ and PMI 10+ leg injuries were not reduced by ABS to the same extent. Indications were found suggesting that the benefits of ABS together with CBS may be greater than ABS alone. This article indicated that motorcycle ABS reduced impairing injuries

  15. Identification of Bacillus thuringiensis Cry1AbMod binding-proteins from Spodoptera frugiperda.

    Science.gov (United States)

    Martínez de Castro, Diana L; García-Gómez, Blanca I; Gómez, Isabel; Bravo, Alejandra; Soberón, Mario

    2017-12-01

    Bacillus thuringiensis Cry toxins are currently used for pest control in transgenic crops but evolution of resistance by the insect pests threatens the use of this technology. The Cry1AbMod toxin was engineered to lack the alpha helix-1 of the parental Cry1Ab toxin and was shown to counter resistance to Cry1Ab and Cry1Ac toxins in different insect species including the fall armyworm Spodoptera frugiperda. In addition, Cry1AbMod showed enhanced toxicity to Cry1Ab-susceptible S. frugiperda populations. To gain insights into the mechanisms of this Cry1AbMod-enhanced toxicity, we isolated the Cry1AbMod toxin binding proteins from S. frugiperda brush border membrane vesicles (BBMV), which were identified by pull-down assay and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The LC-MS/MS results indicated that Cry1AbMod toxin could bind to four classes of aminopeptidase (N1, N3, N4 y N5) and actin, with the highest amino acid sequence coverage acquired for APN 1 and APN4. In addition to these proteins, we found other proteins not previously described as Cry toxin binding proteins. This is the first report that suggests the interaction between Cry1AbMod and APN in S. frugiperda. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Comparative Study of Electroless Copper Film on Different Self-Assembled Monolayers Modified ABS Substrate

    Directory of Open Access Journals (Sweden)

    Jiushuai Xu

    2014-04-01

    Full Text Available Copper films were grown on (3-Mercaptopropyltrimethoxysilane (MPTMS, (3-Aminopropyltriethoxysilane (APTES and 6-(3-(triethoxysilylpropylamino-1,3,5- triazine-2,4-dithiol monosodium (TES self-assembled monolayers (SAMs modified acrylonitrile-butadiene-styrene (ABS substrate via electroless copper plating. The copper films were examined using scanning electron microscopy (SEM and X-ray diffraction (XRD. Their individual deposition rate and contact angle were also investigated to compare the properties of SAMs and electroless copper films. The results indicated that the formation of copper nuclei on the TES-SAMs modified ABS substrate was faster than those on the MPTMS-SAMs and APTES-SAMs modified ABS substrate. SEM images revealed that the copper film on TES-SAM modified ABS substrate was smooth and uniform, and the density of copper nuclei was much higher. Compared with that of TES-SAMs modified resin, the coverage of copper nuclei on MPTMS and APTES modified ABS substrate was very limited and the copper particle size was too big. The adhesion property test demonstrated that all the SAMs enhanced the interfacial interaction between copper plating and ABS substrate. XRD analysis showed that the copper film deposited on SAM-modified ABS substrate had a structure with Cu(111 preferred orientation, and the copper film deposited on TES-SAMs modified ABS substrate is better than that deposited on MPTMS-SAMs or APTES-SAMs modified ABS resins in electromigrtion resistance.

  17. Development of Anti-lock Braking System (ABS) for Vehicles Braking

    Science.gov (United States)

    Minh, Vu Trieu; Oamen, Godwin; Vassiljeva, Kristina; Teder, Leo

    2016-11-01

    This paper develops a real laboratory of anti-lock braking system (ABS) for vehicle and conducts real experiments to verify the ability of this ABS to prevent the vehicle wheel from being locked while braking. Two controllers of PID and fuzzy logic are tested for analysis and comparison. This ABS laboratory is designed for bachelor and master students to simulate and analyze performances of ABS with different control techniques on various roads and load conditions. This paper provides educational theories and practices on the design of control for system dynamics.

  18. Initial Chemical Events in CL-20 Under Extreme Conditions: An Ab Initio Molecular Dynamics Study

    National Research Council Canada - National Science Library

    Isaev, Olexandr; Kholod, Yana; Gorb, Leonid; Qasim, Mohammad; Fredrickson, Herb; Leszczynski, Jerzy

    2006-01-01

    .... In the present study molecular structure, electrostatic potential, vibrational spectrum and dynamics of thermal decomposition of CL-20 have been investigated by static and dynamic methods of ab...

  19. Effects of 4WD and ABS of safe driving on slippery roads; Tei {mu} ji ni okeru 4WD to ABS no koka to unten sosa hoho

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, Y [National Research Inst. of Police Science, Tokyo (Japan); Takigami, K; Asano, K [Japan Safe Driving Center, Tokyo (Japan); Nagai, M [Tokyo University of Agriculture and Technology, Tokyo (Japan)

    1997-10-01

    Effects of 4WD and ABS on safe driving were examined by brake, obstacle avoidance, acceleration, cornering and lane-changing tests on slippery road. The braking operations, used in these tests, are full, intermitted and modulated brakings. As the results of discussion, the major findings are (1) ABS is effective to shorten the stopping distance and to increase the ability of obstacle avoidance in many cases, (2) `Modulated Braking (without wheel locks)` has the same function as ABS, and (3) 4WD is effective to increase the stability while accelerating, cornering and lane-changing. 5 refs., 6 figs.

  20. Cyclodialysis ab interno as a surgical approach to intractable glaucoma.

    Science.gov (United States)

    Jordan, Jens F; Dietlein, Thomas S; Dinslage, Sven; Lüke, Christoph; Konen, Walter; Krieglstein, Günter K

    2007-08-01

    In glaucoma filtration surgery, the problem of subconjunctival scarring has still not been satisfactorily solved. Suprachoroidal drainage of aqueous humour offers a promising, alternative option for intractable glaucoma. We here present a clinical study on the surgical approach of gonioscopic cyclodialysis ab interno. Twenty-eight eyes of 20 patients with intractable glaucoma were included in this prospective, consecutive, case-control study. The eyes had had a mean of 4.4 +/- 2.4 previous antiglaucomatous interventions. Baseline intraocular pressure (IOP) was 34.3 +/- 10.5 mmHg despite maximum therapy. Under gonioscopic control, cyclodialysis ab interno was performed over two clock times to gain access to the suprachoroidal space. No additional trabecular meshwork surgery was performed. Success was defined as a lowering of IOP to below 21 mmHg without the need for further medication or intervention. Mean postoperative IOP was 14.6 +/- 12.4 mmHg. Mean follow-up (FU) for all eyes was 121.8 days. After a mean of 60 days, 21 eyes (75%) needed further surgical intervention. Qualified success was seen in four eyes (14.3%), with a mean FU of 383.6 days. Three eyes (10.7%) showed absolute success after a mean FU period of 202.7 days. In our series, we obtained the best results for phakic eyes, followed by pseudophakic and aphakic eyes. The results of this study do not provide convincing evidence of the functional efficacy of cyclodialysis ab interno. Nevertheless, the technique is easy to perform and offers safe and atraumatic access to the resorptive capability of the choroid. Conjunctival manipulation is avoided. Contrary to reports in the current literature, in our series, the best results were obtained for phakic eyes, though the small number of eyes included does not allow reliable statistics. Further studies will need to focus on the use of different space-retaining substances or a widening of the cyclodialysis cleft to improve surgical outcome.

  1. Cell Culture Systems To Study Human Herpesvirus 6A/B Chromosomal Integration.

    Science.gov (United States)

    Gravel, Annie; Dubuc, Isabelle; Wallaschek, Nina; Gilbert-Girard, Shella; Collin, Vanessa; Hall-Sedlak, Ruth; Jerome, Keith R; Mori, Yasuko; Carbonneau, Julie; Boivin, Guy; Kaufer, Benedikt B; Flamand, Louis

    2017-07-15

    Human herpesviruses 6A/B (HHV-6A/B) can integrate their viral genomes in the telomeres of human chromosomes. The viral and cellular factors contributing to HHV-6A/B integration remain largely unknown, mostly due to the lack of efficient and reproducible cell culture models to study HHV-6A/B integration. In this study, we characterized the HHV-6A/B integration efficiencies in several human cell lines using two different approaches. First, after a short-term infection (5 h), cells were processed for single-cell cloning and analyzed for chromosomally integrated HHV-6A/B (ciHHV-6A/B). Second, cells were infected with HHV-6A/B and allowed to grow in bulk for 4 weeks or longer and then analyzed for the presence of ciHHV-6. Using quantitative PCR (qPCR), droplet digital PCR, and fluorescent in situ hybridization, we could demonstrate that HHV-6A/B integrated in most human cell lines tested, including telomerase-positive (HeLa, MCF-7, HCT-116, and HEK293T) and telomerase-negative cell lines (U2OS and GM847). Our results also indicate that inhibition of DNA replication, using phosphonoacetic acid, did not affect HHV-6A/B integration. Certain clones harboring ciHHV-6A/B spontaneously express viral genes and proteins. Treatment of cells with phorbol ester or histone deacetylase inhibitors triggered the expression of many viral genes, including U39 , U90 , and U100 , without the production of infectious virus, suggesting that the tested stimuli were not sufficient to trigger full reactivation. In summary, both integration models yielded comparable results and should enable the identification of viral and cellular factors contributing to HHV-6A/B integration and the screening of drugs influencing viral gene expression, as well as the release of infectious HHV-6A/B from the integrated state. IMPORTANCE The analysis and understanding of HHV-6A/B genome integration into host DNA is currently limited due to the lack of reproducible and efficient viral integration systems. In the

  2. Effect of gamma irradiation on nutritional components and Cry1Ab protein in the transgenic rice with a synthetic cry1Ab gene from Bacillus thuringiensis

    International Nuclear Information System (INIS)

    Wu Dianxing; Ye Qingfu; Wang Zhonghua; Xia Yingwu

    2004-01-01

    The effects of gamma irradiation on the transgenic rice containing a synthetic cry1Ab gene from Bacillus thuringiensis were investigated. There was almost no difference in the content of the major nutritional components, i.e. crude protein, crude lipid, eight essential amino acids and total ash between the irradiated grains and the non-irradiated transgenic rice. However, the amounts of Cry1Ab protein and apparent amylose in the irradiated transgenic rice were reduced significantly by the doses higher than 200 Gy. In vivo observation showed that Cry1Ab protein contents also decreased in the fresh leaf tissues of survival seedlings after irradiation with 200 Gy or higher doses and showed inhibition of seedling growth. The results indicate that gamma irradiation might improve the quality of transgenic rice due to removal of the toxic Cry1Ab protein

  3. Erythema Ab igne after footbath with Chinese herbal remedies

    Directory of Open Access Journals (Sweden)

    Jeng-Feng Chen

    2011-01-01

    Full Text Available Erythema ab igne (EAI is a reticulated, telangiectatic, and hyperpigmented skin eruption resulting from chronic exposure to long-term moderate heat. The incidence has decreased substantially today because of the advent of modern central heating systems. Recently, we encountered a patient who developed EAI after 2 weeks of footbaths with Chinese herbal remedies, which she used to treat her acute ankle sprain. Alternative Chinese medicine, such as herbal footbath, is a prevalent medical practice to treat acute pains as well as many chronic musculoskeletal ailments among Chinese and Asian populations. It has also become increasingly popular in Western countries in the past decade. Herein, we would like to report an uncommon case of iatrogenic EAI caused by footbath and raise the attention of clinicians to such rare, potentially malignant-transforming, dermatosis.

  4. Simple calculation of ab initio melting curves: Application to aluminum.

    Science.gov (United States)

    Robert, Grégory; Legrand, Philippe; Arnault, Philippe; Desbiens, Nicolas; Clérouin, Jean

    2015-03-01

    We present a simple, fast, and promising method to compute the melting curves of materials with ab initio molecular dynamics. It is based on the two-phase thermodynamic model of Lin et al [J. Chem. Phys. 119, 11792 (2003)] and its improved version given by Desjarlais [Phys. Rev. E 88, 062145 (2013)]. In this model, the velocity autocorrelation function is utilized to calculate the contribution of the nuclei motion to the entropy of the solid and liquid phases. It is then possible to find the thermodynamic conditions of equal Gibbs free energy between these phases, defining the melting curve. The first benchmark on the face-centered cubic melting curve of aluminum from 0 to 300 GPa demonstrates how to obtain an accuracy of 5%-10%, comparable to the most sophisticated methods, for a much lower computational cost.

  5. Ab initio study of II-(VI){sub 2} dichalcogenides

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, P; Vidal, J; Lincot, D, E-mail: polsson@kth.se [Institut de R and D sur l' energie photovoltaique (IRDEP), UMR 7174-EDF-CNRS-ENSCP, 6 quai Watier, 78401 Chatou Cedex (France)

    2011-10-12

    The structural stabilities of the (Zn,Cd)(S,Se,Te){sub 2} dichalcogenides have been determined ab initio. These compounds are shown to be stable in the pyrite phase, in agreement with available experiments. Structural parameters for the ZnTe{sub 2} pyrite semiconductor compound proposed here are presented. The opto-electronic properties of these dichalcogenide compounds have been calculated using quasiparticle GW theory. Bandgaps, band structures and effective masses are proposed as well as absorption coefficients and refraction indices. The compounds are all indirect semiconductors with very flat conduction band dispersion and high absorption coefficients. The work functions and surface properties are predicted. The Te and Se based compounds could be of interest as absorber materials in photovoltaic applications. (paper)

  6. A hydronitrogen solid: high pressure ab initio evolutionary structure searches

    International Nuclear Information System (INIS)

    Hu Anguang; Zhang Fan

    2011-01-01

    High pressure ab initio evolutionary structure searches resulted in a hydronitrogen solid with a composition of (NH) 4 . The structure searches also provided two molecular isomers, ammonium azide (AA) and trans-tetrazene (TTZ) which were previously discovered experimentally and can be taken as molecular precursors for high pressure synthesis of the hydronitrogen solid. The computed pressure versus enthalpy diagram showed that the transformation pressure to the hydronitrogen solid is 36 GPa from AA and 75 GPa from TTZ. Its metastability was analyzed by the phonon dispersion spectrum and room-temperature vibrational density of state together with the transformation energy barrier back to molecular phases at 298 K. The predicted energy barrier of 0.21 eV/atom means that the proposed hydronitrogen solid should be very stable at ambient conditions. (fast track communication)

  7. High-throughput ab-initio dilute solute diffusion database.

    Science.gov (United States)

    Wu, Henry; Mayeshiba, Tam; Morgan, Dane

    2016-07-19

    We demonstrate automated generation of diffusion databases from high-throughput density functional theory (DFT) calculations. A total of more than 230 dilute solute diffusion systems in Mg, Al, Cu, Ni, Pd, and Pt host lattices have been determined using multi-frequency diffusion models. We apply a correction method for solute diffusion in alloys using experimental and simulated values of host self-diffusivity. We find good agreement with experimental solute diffusion data, obtaining a weighted activation barrier RMS error of 0.176 eV when excluding magnetic solutes in non-magnetic alloys. The compiled database is the largest collection of consistently calculated ab-initio solute diffusion data in the world.

  8. The ab-initio density matrix renormalization group in practice.

    Science.gov (United States)

    Olivares-Amaya, Roberto; Hu, Weifeng; Nakatani, Naoki; Sharma, Sandeep; Yang, Jun; Chan, Garnet Kin-Lic

    2015-01-21

    The ab-initio density matrix renormalization group (DMRG) is a tool that can be applied to a wide variety of interesting problems in quantum chemistry. Here, we examine the density matrix renormalization group from the vantage point of the quantum chemistry user. What kinds of problems is the DMRG well-suited to? What are the largest systems that can be treated at practical cost? What sort of accuracies can be obtained, and how do we reason about the computational difficulty in different molecules? By examining a diverse benchmark set of molecules: π-electron systems, benchmark main-group and transition metal dimers, and the Mn-oxo-salen and Fe-porphine organometallic compounds, we provide some answers to these questions, and show how the density matrix renormalization group is used in practice.

  9. Superfluid 3He A-B surface tension

    International Nuclear Information System (INIS)

    Bartkowiak, M.; Haley, R.P.; Fisher, S.N.; Guenault, A.M.; Pickett, G.R.; Skyba, P.

    2003-01-01

    We have made two different measurements of interfacial energies below 300 μK, at zero pressure and in magnetic fields up to 400 mT. A variable magnetic field profile allows us to stabilize and precisely manipulate the position of the A-B interface. First, we can derive the difference in wall wetting energies from the behaviour of the phase boundary as it enters and exits a stack of glass capillary tubes. Secondly, we can measure the surface tension from the level of over- or under-magnetization needed to force the interface through an aperture. These are the first surface energy measurements in high magnetic fields in the zero-temperature limit. Our results are in surprising agreement with earlier measurements at high pressure close to T c

  10. The ab-initio density matrix renormalization group in practice

    Energy Technology Data Exchange (ETDEWEB)

    Olivares-Amaya, Roberto; Hu, Weifeng; Sharma, Sandeep; Yang, Jun; Chan, Garnet Kin-Lic [Department of Chemistry, Princeton University, Princeton, New Jersey 08544 (United States); Nakatani, Naoki [Department of Chemistry, Princeton University, Princeton, New Jersey 08544 (United States); Catalysis Research Center, Hokkaido University, Kita 21 Nishi 10, Sapporo, Hokkaido 001-0021 (Japan)

    2015-01-21

    The ab-initio density matrix renormalization group (DMRG) is a tool that can be applied to a wide variety of interesting problems in quantum chemistry. Here, we examine the density matrix renormalization group from the vantage point of the quantum chemistry user. What kinds of problems is the DMRG well-suited to? What are the largest systems that can be treated at practical cost? What sort of accuracies can be obtained, and how do we reason about the computational difficulty in different molecules? By examining a diverse benchmark set of molecules: π-electron systems, benchmark main-group and transition metal dimers, and the Mn-oxo-salen and Fe-porphine organometallic compounds, we provide some answers to these questions, and show how the density matrix renormalization group is used in practice.

  11. Quantitative verification of ab initio self-consistent laser theory.

    Science.gov (United States)

    Ge, Li; Tandy, Robert J; Stone, A D; Türeci, Hakan E

    2008-10-13

    We generalize and test the recent "ab initio" self-consistent (AISC) time-independent semiclassical laser theory. This self-consistent formalism generates all the stationary lasing properties in the multimode regime (frequencies, thresholds, internal and external fields, output power and emission pattern) from simple inputs: the dielectric function of the passive cavity, the atomic transition frequency, and the transverse relaxation time of the lasing transition.We find that the theory gives excellent quantitative agreement with full time-dependent simulations of the Maxwell-Bloch equations after it has been generalized to drop the slowly-varying envelope approximation. The theory is infinite order in the non-linear hole-burning interaction; the widely used third order approximation is shown to fail badly.

  12. Ab initio elastic properties and tensile strength of crystalline hydroxyapatite.

    Science.gov (United States)

    Ching, W Y; Rulis, Paul; Misra, A

    2009-10-01

    We report elastic constant calculation and a "theoretical" tensile experiment on stoichiometric hydroxyapatite (HAP) crystal using an ab initio technique. These results compare favorably with a variety of measured data. Theoretical tensile experiments are performed on the orthorhombic cell of HAP for both uniaxial and biaxial loading. The results show considerable anisotropy in the stress-strain behavior. It is shown that the failure behavior of the perfect HAP crystal is brittle for tension along the z-axis with a maximum stress of 9.6 GPa at 10% strain. Biaxial failure envelopes from six "theoretical" loading tests show a highly anisotropic pattern. Structural analysis of the crystal under various stages of tensile strain reveals that the deformation behavior manifests itself mainly in the rotation of the PO(4) tetrahedron with concomitant movements of both the columnar and axial Ca ions. These results are discussed in the context of mechanical properties of bioceramic composites relevant to mineralized tissues.

  13. Ab initio methods for electron-molecule collisions

    International Nuclear Information System (INIS)

    Collins, L.A.; Schneider, B.I.

    1987-01-01

    This review concentrates on the recent advances in treating the electronic aspect of the electron-molecule interaction and leaves to other articles the description of the rotational and vibrational motions. Those methods which give the most complete treatment of the direct, exchange, and correlation effects are focused on. Such full treatments are generally necessary at energies below a few Rydbergs (≅ 60 eV). This choice unfortunately necessitates omission of those active and vital areas devoted to the development of model potentials and approximate scattering formulations. The ab initio and model approaches complement each other and are both extremely important to the full explication of the electron-scattering process. Due to the rapid developments of recent years, the approaches that provide the fullest treatment are concentrated on. 81 refs

  14. Ab initio Eliashberg Theory: Making Genuine Predictions of Superconducting Features

    Science.gov (United States)

    Sanna, Antonio; Flores-Livas, José A.; Davydov, Arkadiy; Profeta, Gianni; Dewhurst, Kay; Sharma, Sangeeta; Gross, E. K. U.

    2018-04-01

    We present an application of Eliashberg theory of superconductivity to study a set of novel superconducting systems with a wide range of structural and chemical properties. The set includes three intercalated group-IV honeycomb layered structures, SH3 at 200 GPa (the superconductor with the highest measured critical temperature), the similar system SeH3 at 150 GPa, and a lithium doped mono-layer of black phosphorus. The theoretical approach we adopt is a recently developed, fully ab initio Eliashberg approach that takes into account the Coulomb interaction in a full energy-resolved fashion avoiding any free parameters like μ*. This method provides reasonable estimations of superconducting properties, including TC and the excitation spectra of superconductors.

  15. Ab Initio Symmetry-Adapted No-Core Shell Model

    International Nuclear Information System (INIS)

    Draayer, J P; Dytrych, T; Launey, K D

    2011-01-01

    A multi-shell extension of the Elliott SU(3) model, the SU(3) symmetry-adapted version of the no-core shell model (SA-NCSM), is described. The significance of this SA-NCSM emerges from the physical relevance of its SU(3)-coupled basis, which – while it naturally manages center-of-mass spuriosity – provides a microscopic description of nuclei in terms of mixed shape configurations. Since typically configurations of maximum spatial deformation dominate, only a small part of the model space suffices to reproduce the low-energy nuclear dynamics and hence, offers an effective symmetry-guided framework for winnowing of model space. This is based on our recent findings of low-spin and high-deformation dominance in realistic NCSM results and, in turn, holds promise to significantly enhance the reach of ab initio shell models.

  16. Ab Initio Analysis of Auger-Assisted Electron Transfer.

    Science.gov (United States)

    Hyeon-Deuk, Kim; Kim, Joonghan; Prezhdo, Oleg V

    2015-01-15

    Quantum confinement in nanoscale materials allows Auger-type electron-hole energy exchange. We show by direct time-domain atomistic simulation and analytic theory that Auger processes give rise to a new mechanism of charge transfer (CT) on the nanoscale. Auger-assisted CT eliminates the renown Marcus inverted regime, rationalizing recent experiments on CT from quantum dots to molecular adsorbates. The ab initio simulation reveals a complex interplay of the electron-hole and charge-phonon channels of energy exchange, demonstrating a variety of CT scenarios. The developed Marcus rate theory for Auger-assisted CT describes, without adjustable parameters, the experimental plateau of the CT rate in the region of large donor-acceptor energy gap. The analytic theory and atomistic insights apply broadly to charge and energy transfer in nanoscale systems.

  17. American brachytherapy society (ABS) guidelines for brachytherapy of esophageal cancer

    International Nuclear Information System (INIS)

    Nag, Subir; Gaspar, Laurie; Herskovic, Arnold; Mantravadi, Prasad; Speiser, Burton

    1996-01-01

    Introduction: There is wide variation in the indications, techniques, treatment regimens and dosimetry being used to treat cancer of the esophagus and no guidelines exist for optimal therapy. Methods: The Clinical Research Committee of the ABS met to formulate consensus guidelines for brachytherapy in esophageal cancer. Results: Good candidates for brachytherapy include patients with unifocal disease, with thoracic tumor 10 cm primary regional lymph adenopathy or tumor located in the gastro-esophageal junction or cervical esophagus. Contraindications include tracheo-esophageal fistula or stenosis that cannot be by-passed. The esophageal or nasogastric tube inserted should have a diameter of 6-10 mm whenever possible. If 5FU-based chemotherapy and 50 Gy external beam (EBRT) are used, it is suggested that the low dose rate brachytherapy (LDR) dose be 20 Gy at 0.4-1 Gy/hr, prescribed at 1 cm from the source. If high dose rate (HDR) is used, the dose recommended is 10 Gy in 2 weekly fractions of 5 Gy each, given after EBRT. Chemotherapy is not usually given concurrently with brachytherapy, and when it is, the brachytherapy dose is reduced. The length of esophagus treated by brachytherapy includes the post-EBRT involved area and a 1-2 cm margin proximally and distally. Supportive care, given during EBRT includes an antifungal agent (e.g., diflucan) and carafate. Gradual dilatation of the esophagus is required post-treatment for esophageal strictures. Conclusion: Guidelines were developed for brachytherapy in esophageal cancer. As more clinical data becomes available, these guidelines will be updated by the ABS

  18. H3+: Ab initio calculation of the vibration spectrum

    International Nuclear Information System (INIS)

    Carney, G.D.; Porter, R.N.

    1976-01-01

    The vibration spectrum of H 3 + is calculated from the representation of a previously reported [J. Chem Phys. 60, 4251 (1974)] ab initio potential-energy surface in a fifth degree Simons--Parr--Finlan (SPF) expansion. Morse- and harmonic-oscillator basis functions are used to describe the motions of the three oscillators and the Harris--Engerholm--Gwinn quadrature technique is used to obtain matrix elements of the Hamiltonian in the basis of vibrational configurations. Our variational method is thus analogous to configuration--interaction calculations for electronic states. The ground state is found to have a zero-point energy of 4345 cm -1 and a vibrationally averaged geometry of R 1 =R 2 =0.91396 A, theta=60.0012degree, where theta is the angle between the two equivalent bonds. The transition frequencies for the E and A 1 fundamentals are nu-bar/sub E/=2516 cm -1 and nu-bar/sub A/=3185 cm -1 and those for the corresponding first overtones of the bending mode are 2nu-bar/sub E/=5004 +- 4 cm -1 and 2nu-bar/sub A/=4799 cm -1 . The first overtone of the breathing mode is 6264 cm -1 . The first-excited A 1 vibration state is metastable with a dipole--radiation lifetime of 3 sec. Transition frequencies, Einstein coefficients, and lifetimes are reported for a total of 21 transitions. Analysis of results for Dunham number and normal-coordinate expansions in comparison with those for SPF expansion show the latter to be superior for ab initio vibrational calculations. A scheme for possible direct measurement of the fundamental A 1 and E vibrational bands is suggested

  19. CULTURA ORGANIZACIONAL: UM ESTUDO DE CASO NA EMPRESA MGO

    Directory of Open Access Journals (Sweden)

    Vagner Luís Wentz

    2012-07-01

    Full Text Available O tema cultura tem sido objeto de estudo há muitos anos, e as literaturas existentes apontam uma grande diversidade de conceitos, o que torna as organizações grandes fontes de pesquisa. A MGO, uma multinacional fabricante de produtos agrícolas, convive constantemente com mudanças de seus procedimentos, de suas tarefas do cotidiano e de comportamentos por parte de seus colaboradores, uma relação entre “novatos” e “veteranos” que, em alguns casos, é geradora de conflitos, o que pode vir a prejudicar a imagem da companhia. Diante disso, este estudo tem como objetivo geral analisar a cultura organizacional a partir da percepção das lideranças de uma unidade da empresa MGO situada em Montenegro/RS. Esta pesquisa se classifica, quanto aos procedimentos, como bibliográfica e estudo de caso; quanto aos objetivos, como descritiva; e quanto ao problema, esta pesquisa é classificada como qualitativa. A partir da análise dos dados coletados através de entrevistas semiestruturadas com as lideranças de departamentos diferentes, análise de documentos, observação participante e aplicação do teste para identificação da tipologia de cultura, pode-se identificar a cultura da organização e sugerir algumas melhorias que podem ajudar na harmonia do clima da organização. Palavras-chave: Cultura. Clima. Organização.

  20. Expression of Cry1Ab and Cry2Ab by a polycistronic transgene with a self-cleavage peptide in rice.

    Directory of Open Access Journals (Sweden)

    Qichao Zhao

    Full Text Available Insect resistance to Bacillus thuringiensis (Bt crystal protein is a major threat to the long-term use of transgenic Bt crops. Gene stacking is a readily deployable strategy to delay the development of insect resistance while it may also broaden insecticidal spectrum. Here, we report the creation of transgenic rice expressing discrete Cry1Ab and Cry2Ab simultaneously from a single expression cassette using 2A self-cleaving peptides, which are autonomous elements from virus guiding the polycistronic viral gene expression in eukaryotes. The synthetic coding sequences of Cry1Ab and Cry2Ab, linked by the coding sequence of a 2A peptide from either foot and mouth disease virus or porcine teschovirus-1, regardless of order, were all expressed as discrete Cry1Ab and Cry2Ab at high levels in the transgenic rice. Insect bioassays demonstrated that the transgenic plants were highly resistant to lepidopteran pests. This study suggested that 2A peptide can be utilized to express multiple Bt genes at high levels in transgenic crops.

  1. Craniostenose em gêmeos: estudo genético

    Directory of Open Access Journals (Sweden)

    Walter Carlos Pereira

    1968-09-01

    Full Text Available É relatada a ocorrência de formas clínicas diversas de craniostenose em gêmeos de sexo diferente. A menina apresentava obliteração completa da sutura coronaria e dos dois terços anteriores da sutura sagital; no menino a sutura sagital era a única afetada. O estudo genético mostrou que a craniostenose independe de aberrações cromossômicas, indicando ser transmitida por gens recessivos raros de natureza autossômica.

  2. Marketing educacional: um estudo comparativo das atividades de marketing

    OpenAIRE

    Marta Maria Cunha Carneiro

    2015-01-01

    A revisão teórica apontou uma visão geral dos temas de marketing e educação por meio da cronologia histórica, da discussão conceitual, da relevância teórica e prática de cada assunto, dos principais desafios para pesquisa e o desenvolvimento do tema marketing educacional. Identificou-se e discutiu-se as atividades de marketing desenvolvidas nas instituições de ensino superior à luz dos fundamentos teóricos. A metodologia abordou os aspectos relacionados ao protocolo do estudo de caso e uma pe...

  3. Encefalopatia hepática: estudo de 50 casos

    Directory of Open Access Journals (Sweden)

    Luiz Antonio de Lima Resende

    1984-12-01

    Full Text Available Os autores apresentam estudo retrospectivo de 50 pacientes com encefalopatia hepática atendidos no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto a partir de 1959 e discutem os aspectos clínicos, laboratoriais e anátomo-patológicos. Expõem os diagnósticos das hepatopatias, os fatores precipitantes dos episódios de coma e pré-coma hepático e enfatizam o papel da gasometria arterial no estabelecimento do diagnóstico.

  4. Estudo dos problemas do carteiro chines e do caixeiro viajante

    OpenAIRE

    Denise Helena Lombardo

    1986-01-01

    Resumo: Esta dissertação envolve o estudo de dois problemas de otimização combinatória: O Problema do Caixeiro Viajante (PCV) e o Problema do Carteiro Chinês (PCC). Dada uma rede (ou grafo), primeiro problema consiste em determinar uma rota circular mínima que passa em cada nó e o segundo em determinar uma rota circular mínima que passa em cada linha da rede. Embora ambos problemas sejam da classe NP-"árduo" (NP- hard ), o problema do Carteiro Chinês é apresentado na literatura como um proble...

  5. Literacia fiscal : um estudo empírico

    OpenAIRE

    Pereira, Ana Isabel Teixeira Duarte

    2014-01-01

    O objetivo desta dissertação prende-se com o estudo da literacia fiscal numa zona rural de Portugal. Aqui se aborda a importância da perceção fiscal que o contribuinte deveria possuir para uma melhor atuação perante situações fiscais com que se depara no seu quotidiano, em seu benefício. O presente trabalho versa também sobre fatores que influenciam o (in)cumprimento fiscal por parte do cidadão contribuinte. A educação fiscal tem impacto no cumprimento fiscal no sentido de que transmite o ...

  6. Estradas de ferro e ensino industrial: um estudo de caso

    OpenAIRE

    Medeiros, Marluce

    1980-01-01

    O objeto deste estudo e o Centro Ferroviário de Ensino e Seleção Profissional de são Paulo , criado em 1934 , conjuntamente pelas ferrovias paulistas e o governo estadual. A criação deste centro em S~ o Paulo deveu-se ao desenvolvimento das ferrovias no estado , por força das necessidades de expansão da economia cafeeira, a exigi r transportes rápidos, baratos , a longa distância. Concorreu igualmente para o surgimento desta instituição , a difusão em são Paulo da doutrina d...

  7. Inteligência emocional: estudo exploratório

    OpenAIRE

    Seabra, Diana Catarina Lopes

    2013-01-01

    A presente dissertação tem como objetivo esclarecer e refletir sobre a inteligência emocional e explorar se existe uma influência entre a atividade que o grupo exerce, o tempo de pertença e o tempo de vida do mesmo, ao nível da inteligência emocional grupal e das suas dimensões. Para tal, foi desenvolvido um estudo exploratório. A recolha dos dados realizou-se através do Questionário de Inteligência Emocional Grupal traduzido e adaptado por Correia (2010) do Group Emotional Intelligence Quest...

  8. Estudo de estabilidade do antibiótico meropenem

    OpenAIRE

    Andreas Sebastian Loureiro Mendez

    2007-01-01

    A estabilidade de medicamentos constitui um tema atual e de grande importância no meio científico. Tem sido constantemente abordada em estudos direcionados à avaliação da qualidade das preparações farmacêuticas. O meropenem, um antibiótico carbapenêmico de amplo espectro de ação, é utilizado como um importante recurso terapêutico para o tratamento de infecções graves. Por ser um agente antimicrobiano ativo e eficaz, de uso clínico em muitos países, tornase necessária a pesquisa mais aprofunda...

  9. Estudo da auditoria de contas em um hospital de ensino

    OpenAIRE

    Guerrer, Gabriela Favaro Faria; Lima, Antônio Fernandes Costa; Castilho, Valéria

    2015-01-01

    RESUMOObjetivos:verificar os itens componentes das contas hospitalares, conferidos por enfermeiros auditores, que mais recebem ajustes no momento da pré-análise; identificar o impacto dos ajustes no faturamento das contas analisadas por enfermeiros e médicos auditores e identificar as glosas relacionadas aos itens conferidos pela equipe de auditoria.Método:pesquisa quantitativa exploratória, descritiva, do tipo estudo de caso único.Resultados:após a análise de 2.613 contas constatou-se que o ...

  10. Miopatia miotubular: estudo clinico, eletrofisiologico e histologico de um caso

    Directory of Open Access Journals (Sweden)

    José L. Alonso

    1981-12-01

    Full Text Available São apresentados os resultados dos exames clínicos, eletrofisiológicos e do estudo do ponto motor, da imunofluorescência, da histoquímica e da ultrami-croscopia da biópsia muscular de um caso de miopatia miotubular. São discutidos estes resultados em relação aos achados de 56 casos desta moléstia consignados na literatura até 1978, sendo dada enfase à etiopatogenia.

  11. Bruxas da Serra: Estudo numa comunidade beirã

    OpenAIRE

    Carvalho, Clara

    1984-01-01

    O tema deste trabalho é o estudo das manifestações do discurso da bruxaria numa pequena comunidade beirã situada nas faldas da serra do Caramulo. Nesta aldeia trabalham como "bruxas" cinco dos seus habitantes. Com este trabalho pretendi descrever os métodos utilizados por essas cinco pessoas e os mecanismos que levam a restante população a utilizar esse discurso. Não se trata aqui de um levantamento e análise das diversas figuras designadas pelo termo "bruxa" , tal como foi realizado por Lisó...

  12. "Buzz marketing" : estudo de caso da marca Red Bull

    OpenAIRE

    Conceição, Miguel David

    2012-01-01

    Este relatório é baseado no estágio efetuado na agência de publicidade Ogilvy & Mather e é dedicado à temática do Buzz Marketing. De modo a poder explorar a fundo as dinâmicas deste tema foi feita uma análise à estratégia de marketing da marca Red Bull, considerada como um dos principais estudos de caso no âmbito do Buzz Marketing. Este tema pode ser definido como uma estratégia de marketing inovadora cujo objetivo principal é a criação de conversas entre os consumidores, colocando-os a falar...

  13. Leonid Apananski müüs AB Grupi maa oma firmale / Silva Männik

    Index Scriptorium Estoniae

    Männik, Silva, 1974-

    1999-01-01

    Ilmunud ka: Den za Dnjom Nov/26 lk. 8. Apananski müüs AB Kindlustuse Grupile kuulunud Maakri tänava kinnistu. Skeem: AB Grupist on välja viidud ligikaudu 70 milj. krooni. Ilmunud ka: Den za Dnjom 23. nov. lk. 3

  14. Ab interno trabeculectomy: ultrastructural evidence and early tissue response in a human eye.

    Science.gov (United States)

    Ferrari, Ettore; Ortolani, Fulvia; Petrelli, Lucia; Contin, Magali; Pognuz, Derri Roman; Marchini, Maurizio; Bandello, Francesco

    2007-10-01

    To report the results of ultrastructural analysis of the postoperative effects of ab interno trabeculectomy in a human eye. Department of Ophthalmology, Palmanova Hospital, Palmanova, Udine, Italy. A 60-year-old woman with cataract and glaucoma had enucleation for a choroidal melanoma 10 days after ab interno trabeculectomy combined with phacoemulsification. A second ab interno trabeculectomy was performed after enucleation to evaluate the outcomes of the previous trabeculectomy. Light and transmission electron microscopy analyses were performed on samples excised from areas (1) not subjected to a procedure (control samples), (2) that had ab interno trabeculectomy before enucleation, and (3) that had ab interno trabeculectomy immediately after enucleation. Control samples showed normal trabecular features. Semithin sections of all ab interno trabeculectomy samples showed full-thickness removal of trabeculum segments, with Schlemm's canal lumen opening into the anterior chamber and apparent preservation of the adjacent structures. On ultrathin sections of samples that had ab interno trabeculectomy before enucleation, the endothelium lining the outer wall of Schlemm's canal and other angle components showed intact ultrastructural features. In trabecular beams that were not removed, the extracellular matrix appeared to have maintained its fine texture and was free of activated fibroblasts or leucocyte infiltrates. Observations confirm that ab interno trabeculectomy causes direct communication between Schlemm's canal lumen and the anterior chamber in vivo and immediately after enucleation during the early postoperative period. The absence of an evident inflammatory reaction in the examined case should be considered with caution because of possible tumor-induced immune suppression.

  15. Inhibition of cholera toxin and other AB toxins by polyphenolic compounds

    Science.gov (United States)

    All AB-type protein toxins have intracellular targets despite an initial extracellular location. These toxins use different methods to reach the cytosol and have different effects on the target cell. Broad-spectrum inhibitors against AB toxins are therefore hard to develop because the toxins use dif...

  16. Ab initio and Gordon--Kim intermolecular potentials for two nitrogen molecules

    International Nuclear Information System (INIS)

    Ree, F.H.; Winter, N.W.

    1980-01-01

    Both ab initio MO--LCAO--SCF and the electron-gas (or Gordon--Kim) methods have been used to compute the intermolecular potential (Phi) of N 2 molecules for seven different N 2 --N 2 orientations. The ab initio calculations were carried out using a [4s3p] contracted Gaussian basis set with and without 3d polarization functions. The larger basis set provides adequate results for Phi>0.002 hartree or intermolecular separations less than 6.5--7 bohr. We use a convenient analytic expression to represent the ab initio data in terms of the intermolecular distance and three angles defining the orientations of the two N 2 molecules. The Gordon--Kim method with Rae's self-exchange correction yields Phi, which agrees reasonably well over a large repulsive range. However, a detailed comparison of the electron kinetic energy contributions shows a large difference between the ab initio and the Gordon--Kim calculations. Using the ab initio data we derive an atom--atom potential of the two N 2 molecules. Although this expression does not accurately fit the data at some orientations, its spherical average agrees with the corresponding average of the ab initio Phi remarkably well. The spherically averaged ab initio Phi is also compared with the corresponding quantities derived from experimental considerations. The approach of the ab initio Phi to the classical quadrupole--quadrupole interaction at large intermolecular separation is also discussed

  17. Modeling Disordered Materials with a High Throughput ab-initio Approach

    Science.gov (United States)

    2015-11-13

    Modeling Disordered Materials with a High Throughput ab - initio Approach Kesong Yang,1 Corey Oses,2 and Stefano Curtarolo3, 4 1Department of...J. Furthmüller, Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set, Phys. Rev. B 54, 11169–11186 (1996

  18. Explicit and Implicit Subject Bias in the "ABS Journal Quality Guide"

    Science.gov (United States)

    Hoepner, Andreas G. F.; Unerman, Jeffrey

    2012-01-01

    This paper addresses issues raised in two recent papers published in this journal about the UK "Association of Business Schools' Journal Quality Guide (ABS Guide)". While much of the debate about journal rankings in general, and the "ABS Guide" in particular, has focused on the construction, power and (mis)use of these…

  19. The adnAB Locus, Encoding a Putative Helicase-Nuclease Activity, Is Essential in Streptomyces

    Science.gov (United States)

    Zhang, Lingli; Nguyen, Hoang Chuong; Chipot, Ludovic; Piotrowski, Emilie; Bertrand, Claire

    2014-01-01

    Homologous recombination is a crucial mechanism that repairs a wide range of DNA lesions, including the most deleterious ones, double-strand breaks (DSBs). This multistep process is initiated by the resection of the broken DNA ends by a multisubunit helicase-nuclease complex exemplified by Escherichia coli RecBCD, Bacillus subtilis AddAB, and newly discovered Mycobacterium tuberculosis AdnAB. Here we show that in Streptomyces, neither recBCD nor addAB homologues could be detected. The only putative helicase-nuclease-encoding genes identified were homologous to M. tuberculosis adnAB genes. These genes are conserved as a single copy in all sequenced genomes of Streptomyces. The disruption of adnAB in Streptomyces ambofaciens and Streptomyces coelicolor could not be achieved unless an ectopic copy was provided, indicating that adnAB is essential for growth. Both adnA and adnB genes were shown to be inducible in response to DNA damage (mitomycin C) and to be independently transcribed. Introduction of S. ambofaciens adnAB genes in an E. coli recB mutant restored viability and resistance to UV light, suggesting that Streptomyces AdnAB could be a functional homologue of RecBCD and be involved in DNA damage resistance. PMID:24837284

  20. Embedded atom approach for gold–silicon system from ab initio

    Indian Academy of Sciences (India)

    In the present paper, an empirical embedded atom method (EAM) potential for gold–silicon (Au–Si) is developed by fitting to ab initio force (the 'force matching' method) and experimental data. The force database is generated within ab initio molecular dynamics (AIMD). The database includes liquid phase at various ...

  1. Ultra-low-power, class-AB, CMOS four-quadrant current multiplier

    NARCIS (Netherlands)

    Sawigun, C.; Serdijn, W.A.

    2009-01-01

    A class-AB four-quadrant current multiplier constituted by a class-AB current amplifier and a current splitter which can handle input signals in excess of ten times the bias current is presented. The proposed circuit operation is based on the exponential characteristic of BJTs or subthreshold

  2. Phosphoric acid doped AB-PBI membranes and its applications in high temperature PEMFC

    DEFF Research Database (Denmark)

    He, Ronghuan; Qingfeng, Li; Bjerrum, Niels

    2005-01-01

    Poly(2,5-benzimidazole) (ab-PBI) was prepared from 3,4-diaminobenzoic acid via a polymerisation reaction. The obtained polymer exhibits excellent thermal stability in a temperature range ….. The membrane of ab-PBI when doped with phosphoric acid at room temperaturepresents high proton conductivity...

  3. Radiator-induced erythema ab igne in 8-year-old girl.

    Science.gov (United States)

    Brzezinski, Piotr; Ismail, Samir; Chiriac, Anca

    2014-04-01

    The cutaneous lesion of erythema ab Igne are characterized by a reticulate erythema, hyperpigmentation, fine scaling, epidermal atrophy and telangiectasias, and reticulated erythema. We report a case of erythema ab igne on the hands of a 8-year-old girl, induced by classic homemade radiator.

  4. Preparation of a pure 99mTc-F(ab')2 radioimmunoconjugate by direct labeling methods

    International Nuclear Information System (INIS)

    Griffiths, G.L.; Jones, A.L.; Hansen, H.J.; Goldenberg, D.M.

    1994-01-01

    Intact IgG and Fab' can be labeled directly with 99m Tc to give quantitative incorporation of radioactivity into the protein. With F(ab') 2 the reductive conditions yield a mixture of 99m Tc-F(ab') 2 and 99m Tc-Fab'. We now report a direct labeling method to produce only 99m Tc-F(ab') 2 in quantitative yield and contaminated with 99m Tc-Fab'. The properties, stability and biodistribution of the 99m Tc-F(ab') 2 have been compared to 99m Tc-Fab'. This new technology will allow us to compare technetium direct-labeled IgG, F(ab') 2 and Fab' derivatives of the same antibody for radioimmunodetection. (author)

  5. Summation of Parquet diagrams as an ab initio method in nuclear structure calculations

    International Nuclear Information System (INIS)

    Bergli, Elise; Hjorth-Jensen, Morten

    2011-01-01

    Research highlights: → We present a Green's function based approach for doing ab initio nuclear structure calculations. → In particular the sum the subset of so-called Parquet diagrams. → Applying the theory to a simple but realistic model, results in good agreement with other ab initio methods. → This opens up for ab initio calculations for medium-heavy nuclei. - Abstract: In this work we discuss the summation of the Parquet class of diagrams within Green's function theory as a possible framework for ab initio nuclear structure calculations. The theory is presented and some numerical details are discussed, in particular the approximations employed. We apply the Parquet method to a simple model, and compare our results with those from an exact solution. The main conclusion is that even at the level of approximation presented here, the results shows good agreement with other comparable ab initio approaches.

  6. Influence of Cellulose on the Mechanical and Thermal Stability of ABS Plastic Composites

    Directory of Open Access Journals (Sweden)

    K. Crews

    2016-01-01

    Full Text Available Microcrystalline cellulose was explored as possible biodegradable fillers in the fabrication of ABS plastic composites. TGA indicates that upon inclusion of cellulose microcrystals the thermal stability of the ABS plastics was improved significantly when compared to the neat ABS plastic counterparts. Furthermore, inclusion of extracted cellulose from plant biomass showed a higher thermal stability with maximum decomposition temperatures around 131.95°C and 124.19°C for cellulose from cotton and Hibiscus sabdariffa, respectively, when compared to that of the purchased cellulose. In addition, TMA revealed that the average CTE value for the neat ABS and 1 : 1 ratio of cellulose to ABS fabricated in this study was significantly lower than the reported CTE (ca. 73.8 μm/m°C.

  7. Susceptibility of different subsets of immature thymocytes to apoptosis induced by anti-TCRmAb

    International Nuclear Information System (INIS)

    Li Hongmei; Zhong Renqian; Yu Jiaping; Kong Xiantao; Chen Weifeng

    2003-01-01

    To analysis the susceptibility of different subsets of immature mice thymocytes to apoptosis induced by anti-TCRmAbs in vitro apoptosis was induced in unfractionated mice thymocytes by anti-TCRmAb. In Vivo apoptosis was induced in BALB/c mice by anti-TCR mAb, and thymocytes were examined by FACS. Results showed that CD4 + CD8 + DP thymocytes and CD4 - CD8 + CD3 - thymocytes were equally sensitive to apoptosis after treatment with the anti-TCR mAb. In sharp contrast, the early migrants or precursor containing thymocytes which are CD4 - CD8 - CD3 - TN have a lower spontaneous apoptosis rate and were relatively resistant to the anti-TCR mAb. The findings showed a breakpoint in thymocyte sensitivity to apoptosis which occurs after the onset of CD4 - CD8 + CD3 expression, suggesting that susceptibility of thymocytes to apoptosis is developmentally regulated

  8. Sintomas depressivos em crianças: estudos com duas versões do CDI

    Directory of Open Access Journals (Sweden)

    Miriam Cruvinel

    Full Text Available O objetivo deste estudo foi identificar o número de crianças com sintomas depressivos em duas amostras de estudantes da cidade de campinas. Utilizou-se, no estudo 1, a versão brasileira do Inventário de Depressão Infantil (CDI e, no estudo 2, a versão original. Do estudo 1, realizado em 2001, participaram 169 estudantes de 3ª, 4ª e 5ª séries, e, do estudo 2, conduzido em 2005, 157 alunos de 3ª e 4ª séries. A prevalência de sintomatologia depressiva no estudo 1 foi de 3,55%, e, no estudo 2, de 17%. Em ambos os estudos, não foram encontradas diferenças significativas entre a média no CDI em relação às variáveis demográficas. conclui-se pela necessidade de mais estudos nacionais de prevalência no ensino fundamental e de esforços direcionados não só para a identificação dos fatores de risco, de proteção e das variáveis associadas mas também do refinamento dos instrumentos de medidas da depressão infantil.

  9. Radioimmunoimaging using F(ab')2 fragment of monoclonal antibodies against human alpha-fetoprotein

    International Nuclear Information System (INIS)

    Sakahara, Harumi; Endo, Keigo; Nakashima, Tetsuo; Koizumi, Mitsuru; Ohta, Hitoya; Torizuka, Kanji; Okada, Kenichiro; Yoshida, Osamu; Nishi, Shinzo.

    1985-01-01

    Using monoclonal antibodies against human α-fetoprotein (AFP), radioiodinated F(ab') 2 fragments were compared with whole IgG as a radiotracer for radioimmunoimaging of cancer. F(ab') 2 fragments were obtained by pepsin digestion of whole IgG (IgGl). IgG and F(ab') 2 were labeled with 125 I or 131 I by the chloramine-T method with almost full retention of antibody activity. F(ab') 2 fragments were cleared more rapidly from the circulation in normal mice with a half life of 6.3 hours than whole IgG with a half life of 5.5 days. Radioactivity of F(ab') 2 in various organs also decreased faster than IgG. In nude mice transplanted with AFP-producing human testicular tumor, F(ab') 2 fragments demonstrated superior scintigrams to whole IgG at 2 days after the injection, because of the fast disappearance of background radioactivity. Although absolute accumulation of 131 I labeled F(ab') 2 in the tumor was less than that of 131 I labeled IgG, tumor to other organ ratios were much higher with F(ab') 2 than those of IgG. The tumor to blood ratio of 131 I labeled F(ab') 2 was 1.04 at day 2, whereas tumor to blood ratio of 131 I labeled IgG was 0.55 at day 2 and 0.92 at day 4, respectively. These results indicated that for the radiolabeling of monoclonal antibodies, F(ab') 2 fragments would be superior to whole IgG in the radioimmunoimaging of cancer. (author)

  10. Perspectivas psicossociais para o estudo do cotidiano de trabalho

    Directory of Open Access Journals (Sweden)

    Fábio de Oliveira

    2014-04-01

    Full Text Available Este estudo teve por objetivo analisar o debate e o aprofundamento teórico e metodológico desenvolvido nos estudos sobre a vida cotidiana no trabalho. A investigação partiu do diálogo interdisciplinar entre a antropologia do trabalho, a ergologia e a psicologia social do trabalho e sistematizou as contribuições mútuas entre esses campos científicos, suas aproximações e seus afastamentos da tematização e da apropriação da atividade humana no trabalho sob a perspectiva do cotidiano. A análise comparativa destacou eixos que diferenciam as formas de aproximação ao objeto, que se referem às relações estabelecidas entre saberes práticos e técnico-científicos e aos modos de intervenção sobre as situações de trabalho. As abordagens comparativas compartilham o interesse em conhecer o trabalho real, o valor conferido aos conhecimentos dos trabalhadores e a sensibilidade às dimensões micropolíticas do cotidiano. Conclui-se que a localização em cada um desses eixos depende da maior ou menor filiação às tradições da antropologia ou da ergonomia.

  11. ABORDAGENS SOCIOTÉCNICAS E OS ESTUDOS EM TECNOLOGIA SOCIAL

    Directory of Open Access Journals (Sweden)

    José de Arimatéia Dias Valadão

    2014-05-01

    Full Text Available Este ensaio procura discutir as perspectivas sociotécnicas como base para o desenvolvimento teórico em tecnologia social (TS. Para subsidiar essa discussão foram analisadas a abordagem dos sistemas sociotécnicos elaborada inicialmente por Trist, Emery e colaboradores do Instituto Tavistock; a abordagem da adequação sociotécnica oriunda da perspectiva construtivista da tecnologia e a abordagem dos híbridos sociotécnicos proposta por Latour. O argumento central é que o desenvolvimento de TS deve considerar as tramas de relações, em que tanto os aspectos sociais como técnicos estão imbricados nas organizações, evitando as ênfases de cada corrente e considerando a mediação sociotécnica como principal unidade de análise nos estudos em TS. A motivação dessa discussão é que a aplicação das abordagens sociotécnicas, sem o equilíbrio aparente das mediações sociotécnicas, parece fazer das TS somente mais uma dentre muitas outras abordagens “alternativas”, como os próprios estudos na área têm criticado.

  12. GESTÃO DE MARCAS: UM ESTUDO SOBRE A UNIMED

    Directory of Open Access Journals (Sweden)

    Hellen Taís Zanóbio

    2018-03-01

    Full Text Available O crescimento da demanda por serviços de saúde suplementar somado às mudanças da relação marca versus consumidor tornam esse mercado cada vez mais competitivo. Esses fatores implicam na movimentação das prestadoras deste tipo de serviço em relação à necessidade de identificar e implantar a melhor forma de gestão de marca, com o objetivo de torná-la conhecida e diferenciada. A empresa estudada foi a Unimed, a maior Cooperativa de Trabalho Médico do Brasil, onde se aplica o seguinte problema de pesquisa: quais as estratégias utilizadas pela Unimed na gestão de sua marca? Este estudo tem o objetivo de estudar as estratégias aplicadas pela Unimed em estudos que as exploram utilizando a metodologia de pesquisa de Revisão Bibliográfica. Os resultados obtidos foram o destaque da importância dada pela Unimed à gestão de sua marca onde a centraliza como diferencial competitivo, e o sucesso do uso das estratégias de gestão de marca como a identidade, imagem, personalidade, arquitetura e valor, tornando-a uma marca forte e consolidada no mercado.

  13. Many-body perturbation theory for ab initio nuclear structure

    International Nuclear Information System (INIS)

    Tichai, Alexander

    2017-01-01

    The solution of the quantum many-body problem for medium-mass nuclei using realistic nuclear interactions poses a superbe challenge for nuclear structure research. Because an exact solution can only be provided for the lightest nuclei, one has to rely on approximate solutions when proceeding to heavier systems. Over the past years, tremendous progress has been made in the development and application of systematically improvable expansion methods and an accurate description of nuclear observables has become viable up to mass number A ∼ 100. While closed-shell systems are consistently described via a plethora of different many-body methods, the extension to genuine open-shell systems still remains a major challenge and up to now there is no ab initio many-body method which applies equally well to systems with even and odd mass numbers. The goal of this thesis is the development and implementation of innovative perturbative approaches with genuine open-shell capabilities. This requires the extension of well-known single-reference approaches to more general vacua. In this work we choose two complementary routes for the usage of generalized reference states. First, we derive a new ab initio approach based on multi-configurational reference states that are conveniently derived from a prior no-core shell model calculation. Perturbative corrections are derived via second-order many-body perturbation theory, thus, merging configuration interaction and many-body perturbation theory. The generality of this ansatz enables for a treatment of medium-mass systems with arbitrary mass number, as well as the extension to low-lying excited states such that ground and excited states are treated on an equal footing. In a complementary approach, we use reference states that break a symmetry of the underlying Hamiltonian. In the simplest case this corresponds to the expansion around a particle-number-broken Hartree-Fock-Bogolyubov vacuum which is obtained from a mean-field calculation

  14. Ab initio molecular crystal structures, spectra, and phase diagrams.

    Science.gov (United States)

    Hirata, So; Gilliard, Kandis; He, Xiao; Li, Jinjin; Sode, Olaseni

    2014-09-16

    Conspectus Molecular crystals are chemists' solids in the sense that their structures and properties can be understood in terms of those of the constituent molecules merely perturbed by a crystalline environment. They form a large and important class of solids including ices of atmospheric species, drugs, explosives, and even some organic optoelectronic materials and supramolecular assemblies. Recently, surprisingly simple yet extremely efficient, versatile, easily implemented, and systematically accurate electronic structure methods for molecular crystals have been developed. The methods, collectively referred to as the embedded-fragment scheme, divide a crystal into monomers and overlapping dimers and apply modern molecular electronic structure methods and software to these fragments of the crystal that are embedded in a self-consistently determined crystalline electrostatic field. They enable facile applications of accurate but otherwise prohibitively expensive ab initio molecular orbital theories such as Møller-Plesset perturbation and coupled-cluster theories to a broad range of properties of solids such as internal energies, enthalpies, structures, equation of state, phonon dispersion curves and density of states, infrared and Raman spectra (including band intensities and sometimes anharmonic effects), inelastic neutron scattering spectra, heat capacities, Gibbs energies, and phase diagrams, while accounting for many-body electrostatic (namely, induction or polarization) effects as well as two-body exchange and dispersion interactions from first principles. They can fundamentally alter the role of computing in the studies of molecular crystals in the same way ab initio molecular orbital theories have transformed research practices in gas-phase physical chemistry and synthetic chemistry in the last half century. In this Account, after a brief summary of formalisms and algorithms, we discuss applications of these methods performed in our group as compelling

  15. High Yield Chemical Vapor Deposition Growth of High Quality Large-Area AB Stacked Bilayer Graphene

    Science.gov (United States)

    Liu, Lixin; Zhou, Hailong; Cheng, Rui; Yu, Woo Jong; Liu, Yuan; Chen, Yu; Shaw, Jonathan; Zhong, Xing; Huang, Yu; Duan, Xiangfeng

    2012-01-01

    Bernal stacked (AB stacked) bilayer graphene is of significant interest for functional electronic and photonic devices due to the feasibility to continuously tune its band gap with a vertical electrical field. Mechanical exfoliation can be used to produce AB stacked bilayer graphene flakes but typically with the sizes limited to a few micrometers. Chemical vapor deposition (CVD) has been recently explored for the synthesis of bilayer graphene but usually with limited coverage and a mixture of AB and randomly stacked structures. Herein we report a rational approach to produce large-area high quality AB stacked bilayer graphene. We show that the self-limiting effect of graphene growth on Cu foil can be broken by using a high H2/CH4 ratio in a low pressure CVD process to enable the continued growth of bilayer graphene. A high temperature and low pressure nucleation step is found to be critical for the formation of bilayer graphene nuclei with high AB stacking ratio. A rational design of a two-step CVD process is developed for the growth of bilayer graphene with high AB stacking ratio (up to 90 %) and high coverage (up to 99 %). The electrical transport studies demonstrated that devices made of the as-grown bilayer graphene exhibit typical characteristics of AB stacked bilayer graphene with the highest carrier mobility exceeding 4,000 cm2/V·s at room temperature, comparable to that of the exfoliated bilayer graphene. PMID:22906199

  16. [VDRL and FTA-ABS reactivity in cerebrospinal fluid: our experience].

    Science.gov (United States)

    García-Rodríguez, J A; Martín-Sánchez, A M; Canut, A; García-García, L; Cacho, J

    1990-01-01

    The reactivity of 194 samples of CSF against VDRL and FTA-ABS was studied in patients attending the Clinical Hospital in Salamanca over a five years period. This laboratory was asked to rule out an etiology of syphilis. Twelve samples of CSF proved to be reactive (6.2%) against VDRL and/or FTA-ABS. Seven of these corresponded to six adults diagnosed as suffering from neurosyphilis and one to an infant with early congenital syphilis without neurological alterations; these had in common the presence of active syphilis and a reactive FTA-ABS in serum. In the CSF of the six cases of neurosyphilis, VDRL was reactive in two patients (33.3%) and FTA-ABS in five (83.3%). One minimally reactive VDRL and four FTA-ABS were detected in the remaining five patients, with no known previous history of syphilis, that were suffering from different neurological alterations and that had a nonreactive FTA-ABS in serum. The results obtained in this study point to inappropriate use in CSF of VDRL and FTA-ABS to exclude neurosyphilis in our hospital since only 3.6% of the CSF studied corresponded to patients diagnosed as suffering from neurosyphilis and also to the need for improving the criteria for patient selection.

  17. Numerical evaluation of ABS parts fabricated by fused deposition modeling and vapor smoothing

    Directory of Open Access Journals (Sweden)

    Sung-Uk Zhang

    2017-12-01

    Full Text Available The automotive industry has focused to use polymer materials in order to increase energy efficiency. So, the industry pays attention to use 3D printing technologies using several polymers. Among several 3D printer technologies, fused deposition modeling (FDM is one of the popular 3D printing technologies due to an inexpensive extrusion machine and multi-material printing. FDM could use thermoplastics such as ABS, PLA, ULTEM so on. However, it has a problem related to the post-processing because FDM has relatively poor layer resolution. In this study, the mechanical properties of ABS parts fabricated by FDM were measured. The ABS parts were divided into one with vapor smoothing process and the other without the vapor smoothing process which is one of the post-processing methods. Using dynamic mechanical analysis (DMA and dilatometer, temperature-dependent storage modulus and CTE for ABS specimens were measured. Based on the measured thermo-mechanical properties of ABS parts, finite element analysis was performed for an automotive bumper made of ABS. Moreover, response surface methodology was applied to study relationships among design parameters of thickness of the bumper, ambient temperature, and application of the vapor smoothing process. In result, a design guideline for a ABS product could be provided without time-consuming experiments

  18. Zirconium - ab initio modelling of point defects diffusion

    International Nuclear Information System (INIS)

    Gasca, Petrica

    2010-01-01

    Zirconium is the main element of the cladding found in pressurized water reactors, under an alloy form. Under irradiation, the cladding elongate significantly, phenomena attributed to the vacancy dislocation loops growth in the basal planes of the hexagonal compact structure. The understanding of the atomic scale mechanisms originating this process motivated this work. Using the ab initio atomic modeling technique we studied the structure and mobility of point defects in Zirconium. This led us to find four interstitial point defects with formation energies in an interval of 0.11 eV. The migration paths study allowed the discovery of activation energies, used as entry parameters for a kinetic Monte Carlo code. This code was developed for calculating the diffusion coefficient of the interstitial point defect. Our results suggest a migration parallel to the basal plane twice as fast as one parallel to the c direction, with an activation energy of 0.08 eV, independent of the direction. The vacancy diffusion coefficient, estimated with a two-jump model, is also anisotropic, with a faster process in the basal planes than perpendicular to them. Hydrogen influence on the vacancy dislocation loops nucleation was also studied, due to recent experimental observations of cladding growth acceleration in the presence of this element [fr

  19. Thermal, spectroscopic, and ab initio structural characterization of carprofen polymorphs.

    Science.gov (United States)

    Bruni, Giovanna; Gozzo, Fabia; Capsoni, Doretta; Bini, Marcella; Macchi, Piero; Simoncic, Petra; Berbenni, Vittorio; Milanese, Chiara; Girella, Alessandro; Ferrari, Stefania; Marini, Amedeo

    2011-06-01

    Commercial and recrystallized polycrystalline samples of carprofen, a nonsteroidal anti-inflammatory drug, were studied by thermal, spectroscopic, and structural techniques. Our investigations demonstrated that recrystallized sample, stable at room temperature (RT), is a single polymorphic form of carprofen (polymorph I) that undergoes an isostructural polymorphic transformation by heating (polymorph II). Polymorph II remains then metastable at ambient conditions. Commercial sample is instead a mixture of polymorphs I and II. The thermodynamic relationships between the two polymorphs were determined through the construction of an energy/temperature diagram. The ab initio structural determination performed on synchrotron X-Ray powder diffraction patterns recorded at RT on both polymorphs allowed us to elucidate, for the first time, their crystal structure. Both crystallize in the monoclinic space group type P2(1) /c, and the unit cell similarity index and the volumetric isostructurality index indicate that the temperature-induced polymorphic transformation I → II is isostructural. Polymorphs I and II are conformational polymorphs, sharing a very similar hydrogen bond network, but with different conformation of the propanoic skeleton, which produces two different packing. The small conformational change agrees with the low value of transition enthalpy obtained by differential scanning calorimetry measurements and the small internal energy computed with density functional methods. Copyright © 2011 Wiley-Liss, Inc.

  20. Ab Initio Liquid Water Dynamics in Aqueous TMAO Solution.

    Science.gov (United States)

    Usui, Kota; Hunger, Johannes; Sulpizi, Marialore; Ohto, Tatsuhiko; Bonn, Mischa; Nagata, Yuki

    2015-08-20

    Ab initio molecular dynamics (AIMD) simulations in trimethylamine N-oxide (TMAO)-D2O solution are employed to elucidate the effects of TMAO on the reorientational dynamics of D2O molecules. By decomposing the O-D groups of the D2O molecules into specific subensembles, we reveal that water reorientational dynamics are retarded considerably in the vicinity of the hydrophilic TMAO oxygen (O(TMAO)) atom, due to the O-D···O(TMAO) hydrogen-bond. We find that this reorientational motion is governed by two distinct mechanisms: The O-D group rotates (1) after breaking the O-D···O(TMAO) hydrogen-bond, or (2) together with the TMAO molecule while keeping this hydrogen-bond intact. While the orientational slow-down is prominent in the AIMD simulation, simulations based on force field models exhibit much faster dynamics. The simulated angle-resolved radial distribution functions illustrate that the O-D···O(TMAO) hydrogen-bond has a strong directionality through the sp(3) orbital configuration in the AIMD simulation, and this directionality is not properly accounted for in the force field simulation. These results imply that care must be taken when modeling negatively charged oxygen atoms as single point charges; force field models may not adequately describe the hydration configuration and dynamics.

  1. Ab initio modeling of the motional Stark effect on MAST

    International Nuclear Information System (INIS)

    De Bock, M. F. M.; Conway, N. J.; Walsh, M. J.; Carolan, P. G.; Hawkes, N. C.

    2008-01-01

    A multichord motional Stark effect (MSE) system has recently been built on the MAST tokamak. In MAST the π and σ lines of the MSE spectrum overlap due to the low magnetic field typical for present day spherical tokamaks. Also, the field curvature results in a large change in the pitch angle over the observation volume. The measured polarization angle does not relate to one local pitch angle but to an integration over all pitch angles in the observation volume. The velocity distribution of the neutral beam further complicates the measurement. To take into account volume effects and velocity distribution, an ab initio code was written that simulates the MSE spectrum on MAST. The code is modular and can easily be adjusted for other tokamaks. The code returns the intensity, polarized fraction, and polarization angle as a function of wavelength. Results of the code are presented, showing the effect on depolarization and wavelength dependence of the polarization angle. The code is used to optimize the design and calibration of the MSE diagnostic.

  2. Ab initio modelling of transition metals in diamond

    International Nuclear Information System (INIS)

    Watkins, M; Mainwood, A

    2003-01-01

    Transition metals (TM) from the first transition series are commonly used as solvent catalysts in the synthesis of diamond by high pressure, high temperature processes. Ab initio calculations on these metals, in finite clusters of tetrahedrally coordinated carbon, enable us to investigate trends in their stability and properties. By carrying out systematic studies of interstitial, substitutional and semi-vacancy TM defects, we show that the electronic structure of the TMs is complicated by the presence of 'dangling bonds' when the TM disrupts the crystal lattice: interstitial defects conform to the Ludwig-Woodbury (LW) model, whilst substitutional and semi-vacancy defects move from approximating the LW model early in the transition series to approaching the vacancy model for the heavier metals. Multi-configurational self-consistent field methods allow genuine many-electron states to be modelled; for neutral interstitial, and all substitutional TMs, the crystal fields are found to exceed the exchange energies in strength. Consequently, low spin states are found for these defects. We find substitutional defects to be the most stable, but that semi-vacancy TMs are very similar in energy to the substitutional defects late in the transition series; interstitial defects are only metastable in diamond. Given appropriate charge compensators neutral and positively charged interstitial TM defects were stable, while negatively charged species appeared to be strongly disfavoured

  3. Predicting lattice thermal conductivity with help from ab initio methods

    Science.gov (United States)

    Broido, David

    2015-03-01

    The lattice thermal conductivity is a fundamental transport parameter that determines the utility a material for specific thermal management applications. Materials with low thermal conductivity find applicability in thermoelectric cooling and energy harvesting. High thermal conductivity materials are urgently needed to help address the ever-growing heat dissipation problem in microelectronic devices. Predictive computational approaches can provide critical guidance in the search and development of new materials for such applications. Ab initio methods for calculating lattice thermal conductivity have demonstrated predictive capability, but while they are becoming increasingly efficient, they are still computationally expensive particularly for complex crystals with large unit cells . In this talk, I will review our work on first principles phonon transport for which the intrinsic lattice thermal conductivity is limited only by phonon-phonon scattering arising from anharmonicity. I will examine use of the phase space for anharmonic phonon scattering and the Grüneisen parameters as measures of the thermal conductivities for a range of materials and compare these to the widely used guidelines stemming from the theory of Liebfried and Schölmann. This research was supported primarily by the NSF under Grant CBET-1402949, and by the S3TEC, an Energy Frontier Research Center funded by the US DOE, office of Basic Energy Sciences under Award No. DE-SC0001299.

  4. Physical properties of molybdenum monoboride: Ab-initio study

    Science.gov (United States)

    Rajpoot, Priyanka; Rastogi, Anugya; Verma, U. P.

    2018-02-01

    The Ab initio investigations on structural, electronic, optical and thermal properties of MoB have been reported using full potential linearised-augmented plane wave method within the framework of density functional theory. The exchange and correlation potentials were calculated using the Perdew-Burke-Ernzerhof-Sol generalised gradient approximation. The calculated equilibrium lattice constants and cell volume are in excellent agreement with the experimental results as compared to the available theoretical data. Electronic band structure shows that MoB is metallic in nature. From the partial densities of states of MoB it has been found that major contribution on the Fermi level is due to Mo-4d states. Among the reported optical parameters the large value of reflectivity at low energy shows that MoB can be used as a coating material in IR region. Maximum absorption in extreme UV region shows that it can be used in production of electricity through solar power in space vehicles. Various thermal properties have been calculated in a wide temperature range at high pressures. Change in thermal expansion coefficient with respect to temperature shows that anharmonic effect in MoB is very weak at high temperature. The optical and thermal properties of MoB are presented for the first time in this work.

  5. Development of materials science by Ab initio powder diffraction analysis

    International Nuclear Information System (INIS)

    Fujii, Kotaro

    2015-01-01

    Crystal structure is most important information to understand properties and behavior of target materials. Technique to analyze unknown crystal structures from powder diffraction data (ab initio powder diffraction analysis) enables us to reveal crystal structures of target materials even we cannot obtain a single crystal. In the present article, three examples are introduced to show the power of this technique in the field of materials sciences. The first example is dehydration/hydration of the pharmaceutically relevant material erythrocycin A. In this example, crystal structures of two anhydrous phases were determined from synchrotron X-ray powder diffraction data and their different dehydration/hydration properties were understood from the crystal structures. In the second example, a crystal structure of a three dimensional metal-organic-framework prepared by a mechanochemical reaction was determined from laboratory X-ray powder diffraction data and the reaction scheme has been revealed. In the third example, a crystal structure of a novel oxide-ion conductor of a new structure family was determined from synchrotron X-ray and neutron powder diffraction data which gave an important information to understand the mechanism of the oxide-ion conduction. (author)

  6. Fatigue Characteristics of 3D Printed Acrylonitrile Butadiene Styrene (ABS)

    Science.gov (United States)

    Padzi, M. M.; Bazin, M. M.; Muhamad, W. M. W.

    2017-11-01

    Recently, the use of 3D printer technology has become significant to industries, especially when involving the new product development. 3D printing is a technology, which produces the 3D product or prototype using a layer-by-layer technique. However, there becomes less research on the mechanical performance of the 3D printed component. In the present work, fatigue characteristics of 3D printed specimen have been studied. Acrylonitrile butadiene styrene (ABS) has been chosen as a material research due to its wide applications. Two types of specimen used, which is the 3D printing and moulding specimens. Fused deposition modelling (FDM) technique was used to produce the specimens. The dog bone shape part was produced based on ASTM D638 standard and the tensile test has been carried out to get the mechanical properties. Fatigue test was carried out at 40%, 60% and 80% of the tensile strength. The moulded part shows higher fatigue cycles compared to 3D printed part for all loading percentages. Fatigue lives for 40%, 60% and 80%, were 911, 2645 and 26948 cycles, respectively. The results indicated that 3D printed part has a lower fatigue life, which may not suitable for industrial applications. However, the 3D printed part could be improved by using various parameters and may be introduced in low strength application.

  7. Ab-initio calculations for dilute magnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Belhadji, Brahim

    2008-03-03

    This thesis focusses on ab-initio calculations for the electronic structure and the magnetic properties of dilute magnetic semiconductors (DMS). In particular we aim at the understanding of the complex exchange interactions in these systems. Our calculations are based on density functional theory, being ideally suited for a description of the material specific properties of the considered DMS. Moreover we use the KKR Green function method in connection with the coherent potential approximation (CPA), which allows to include the random substitutional disorder in a mean field-like approximation for the electronic structure. Finally we calculate the exchange coupling constants J{sub ij} between two impurities in a CPA medium by using the Lichtenstein formula and from this calculate the Curie temperature by a numerically exact Monte Carlo method. Based on this analysis we found and investigated four different exchange mechanisms being of importance in DMS systems: Double exchange, p-d exchange, antiferromagnetic superexchanges, and ferromagnetic superexchange. A second topic we have investigated in this thesis is the pressure dependence of the exchange interactions and the Curie temperatures in (Ga,Mn)As and (In,Mn)As, using the LDA and the LDA+U approximations. Exact calculations of T{sub C} by Monte Carlo simulations show a somehow different behavior. (orig.)

  8. Ab initio transport across bismuth selenide surface barriers

    KAUST Repository

    Narayan, Awadhesh

    2014-11-24

    © 2014 American Physical Society. We investigate the effect of potential barriers in the form of step edges on the scattering properties of Bi2Se3(111) topological surface states by means of large-scale ab initio transport simulations. Our results demonstrate the suppression of perfect backscattering, while all other scattering processes, which do not entail a complete spin and momentum reversal, are allowed. Furthermore, we find that the spin of the surface state develops an out-of-plane component as it traverses the barrier. Our calculations reveal the existence of quasibound states in the vicinity of the surface barriers, which appear in the form of an enhanced density of states in the energy window corresponding to the topological state. For double barriers we demonstrate the formation of quantum well states. To complement our first-principles results we construct a two-dimensional low-energy effective model and illustrate its shortcomings. Our findings are discussed in the context of a number of recent experimental works.

  9. Ab initio study of MgH2 formation

    International Nuclear Information System (INIS)

    Novakovic, Nikola; Matovic, Ljiljana; Novakovic, Jasmina Grbovic; Manasijevic, Miodrag; Ivanovic, Nenad

    2009-01-01

    Even if there is considerable literature dealing with structure and properties of MgH 2 compound there are still some uncertain details about nature of bonding governing its formation and decomposition. In order to better understand the processes essential for absorption and desorption of MgH 2 , ab initio DFT based calculations of rutile MgH 2 compound, elemental hcp-Mg, and three different hypothetical hcp-Mg-derived hydrides are performed. Our findings show that all structures are unstable, and that MgH (Wurtzite) is a closest possible candidate for intermediate phase between the hcp-Mg and MgH 2 at 1:1 stoichiometry. An alternative hydration pathway is suggested, including promotion of hcp-Mg to bcc-Mg and consecutive transformation to rutile MgH 2 by means of hydrogen incorporation into Mg matrix. Rutile MgH 2 calculations with various hydrogen vacancies concentration are performed. Calculation shows that at high hydrogen concentration close to 1:2, stable substoichiometric hydride is possible. Calculation also shows that high vacancy (low hydrogen) concentration favors bcc-Mg 2 H over rutile Mg 2 H structure.

  10. Double-walled silicon nanotubes: an ab initio investigation

    Science.gov (United States)

    Lima, Matheus P.

    2018-02-01

    The synthesis of silicon nanotubes realized in the last decade demonstrates multi-walled tubular structures consisting of Si atoms in {{sp}}2 and the {{sp}}3 hybridizations. However, most of the theoretical models were elaborated taking as the starting point {{sp}}2 structures analogous to carbon nanotubes. These structures are unfavorable due to the natural tendency of the Si atoms to undergo {{sp}}3. In this work, through ab initio simulations based on density functional theory, we investigated double-walled silicon nanotubes proposing layered tubes possessing most of the Si atoms in an {{sp}}3 hybridization, and with few {{sp}}2 atoms localized at the outer wall. The lowest-energy structures have metallic behavior. Furthermore, the possibility to tune the band structure with the application of a strain was demonstrated, inducing a metal-semiconductor transition. Thus, the behavior of silicon nanotubes differs significantly from carbon nanotubes, and the main source of the differences is the distortions in the lattice associated with the tendency of Si to make four chemical bonds.

  11. Domain Wall Formation in Ferromagnetic Layers: An Ab Initio Study

    Science.gov (United States)

    Herper, Heike C.

    Domain walls are an inherent feature of ferromagnetic (FM) films consisting of layers with different magnetic orientations. Since FM films are used in electrical devices the question of the influence of domain walls on, e.g., the magnetoresistance has attracted much interest. Besides discussing the resistance contribution of domain walls, it is appropriate to study different types of domain walls and their energy of formation. The behaviour of domain walls is usually discussed within model calculations. In the present paper it is done within an ab initio Green's function technique for layered systems, i.e., the fully relativistic, spin-polarized screened Korringa-Kohn Rostoker method. Results are presented for fcc Co layers covered by two semi-infinite fcc Pt(001) bulk systems or by bulk fcc Co(001), respectively. The resistance, which is caused by the different types of domain walls is discussed within a Kubo-Greenwood approach considering Co(001)/Co24/Co(001) as an example.

  12. Ab initio study of point defects in magnesium oxide

    International Nuclear Information System (INIS)

    Gilbert, C. A.; Kenny, S. D.; Smith, R.; Sanville, E.

    2007-01-01

    Energetics of a variety of point defects in MgO have been considered from an ab initio perspective using density functional theory. The considered defects are isolated Schottky and Frenkel defects and interstitial pairs, along with a number of Schottky defects and di-interstitials. Comparisons were made between the density functional theory results and results obtained from empirical potential simulations and these generally showed good agreement. Both methodologies predicted the first nearest neighbor Schottky defects to be the most energetically favorable of the considered Schottky defects and that the first, second, and fifth nearest neighbor di-interstitials were of similar energy and were favored over the other di-interstitial configurations. Relaxed structures of the defects were analyzed, which showed that empirical potential simulations were accurately predicting the displacements of atoms surrounding di-interstitials, but were overestimating O atom displacement for Schottky defects. Transition barriers were computed for the defects using the nudged elastic band method. Vacancies and Schottky defects were found to have relatively high energy barriers, the majority of which were over 2 eV, in agreement with conclusions reached using empirical potentials. The lowest barriers for di-interstitial transitions were found to be for migration into a first nearest neighbor configuration. Charges were calculated using a Bader analysis and this found negligible charge transfer during the defect transitions and only small changes in the charges on atoms surrounding defects, indicating why fixed charge models work as well as they do

  13. Ab initio modelling of methane hydrate thermophysical properties.

    Science.gov (United States)

    Jendi, Z M; Servio, P; Rey, A D

    2016-04-21

    The key thermophysical properties of methane hydrate were determined using ab initio modelling. Using density functional theory, the second-order elastic constants, heat capacity, compressibility, and thermal expansion coefficient were calculated. A wide and relevant range of pressure-temperature conditions were considered, and the structures were assessed for stability using the mean square displacement and radial distribution functions. Methane hydrate was found to be elastically isotropic with a linear dependence of the bulk modulus on pressure. Equally significant, multi-body interactions were found to be important in hydrates, and water-water interactions appear to strongly influence compressibility like in ice Ih. While the heat capacity of hydrate was found to be higher than that of ice, the thermal expansion coefficient was significantly lower, most likely due to the lower rigidity of hydrates. The mean square displacement gave important insight into stability, heat capacity, and elastic moduli, and the radial distribution functions further confirmed stability. The presented results provide a much needed atomistic thermoelastic characterization of methane hydrates and are essential input for the large-scale applications of hydrate detection and production.

  14. Accurate ab initio vibrational energies of methyl chloride

    International Nuclear Information System (INIS)

    Owens, Alec; Yurchenko, Sergei N.; Yachmenev, Andrey; Tennyson, Jonathan; Thiel, Walter

    2015-01-01

    Two new nine-dimensional potential energy surfaces (PESs) have been generated using high-level ab initio theory for the two main isotopologues of methyl chloride, CH 3 35 Cl and CH 3 37 Cl. The respective PESs, CBS-35  HL , and CBS-37  HL , are based on explicitly correlated coupled cluster calculations with extrapolation to the complete basis set (CBS) limit, and incorporate a range of higher-level (HL) additive energy corrections to account for core-valence electron correlation, higher-order coupled cluster terms, scalar relativistic effects, and diagonal Born-Oppenheimer corrections. Variational calculations of the vibrational energy levels were performed using the computer program TROVE, whose functionality has been extended to handle molecules of the form XY 3 Z. Fully converged energies were obtained by means of a complete vibrational basis set extrapolation. The CBS-35  HL and CBS-37  HL PESs reproduce the fundamental term values with root-mean-square errors of 0.75 and 1.00 cm −1 , respectively. An analysis of the combined effect of the HL corrections and CBS extrapolation on the vibrational wavenumbers indicates that both are needed to compute accurate theoretical results for methyl chloride. We believe that it would be extremely challenging to go beyond the accuracy currently achieved for CH 3 Cl without empirical refinement of the respective PESs

  15. Accurate ab initio vibrational energies of methyl chloride

    Energy Technology Data Exchange (ETDEWEB)

    Owens, Alec, E-mail: owens@mpi-muelheim.mpg.de [Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr (Germany); Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London (United Kingdom); Yurchenko, Sergei N.; Yachmenev, Andrey; Tennyson, Jonathan [Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London (United Kingdom); Thiel, Walter [Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr (Germany)

    2015-06-28

    Two new nine-dimensional potential energy surfaces (PESs) have been generated using high-level ab initio theory for the two main isotopologues of methyl chloride, CH{sub 3}{sup 35}Cl and CH{sub 3}{sup 37}Cl. The respective PESs, CBS-35{sup  HL}, and CBS-37{sup  HL}, are based on explicitly correlated coupled cluster calculations with extrapolation to the complete basis set (CBS) limit, and incorporate a range of higher-level (HL) additive energy corrections to account for core-valence electron correlation, higher-order coupled cluster terms, scalar relativistic effects, and diagonal Born-Oppenheimer corrections. Variational calculations of the vibrational energy levels were performed using the computer program TROVE, whose functionality has been extended to handle molecules of the form XY {sub 3}Z. Fully converged energies were obtained by means of a complete vibrational basis set extrapolation. The CBS-35{sup  HL} and CBS-37{sup  HL} PESs reproduce the fundamental term values with root-mean-square errors of 0.75 and 1.00 cm{sup −1}, respectively. An analysis of the combined effect of the HL corrections and CBS extrapolation on the vibrational wavenumbers indicates that both are needed to compute accurate theoretical results for methyl chloride. We believe that it would be extremely challenging to go beyond the accuracy currently achieved for CH{sub 3}Cl without empirical refinement of the respective PESs.

  16. Otomycosis: a retrospective study Otomicoses: um estudo retrospectivo

    Directory of Open Access Journals (Sweden)

    Zélia Braz Vieira da Silva Pontes

    2009-06-01

    Full Text Available Otomycosis is a fungal infection of the external ear canal with only a few studies about its real frequence in Brazil. AIM: to evaluate otomycosis frequence and characteristics in patients with clinical suspicion of external otitis. STUDY DESIGN: Retrospective study with transversal cohort (2000-2006. MATERIALS AND METHODS:103 patients were assigned to mycological diagnosis (direct microscopic examination and culture. RESULTS: Otomycosis was diagnosed in 19.4% of the patients. Patient age varied from 2 to 66 years (an average of 23.5 years of age, and 60% of otomycosis cases were seen in women between 2 to 20 years of age. Chronic otitis, previous antibiotic therapy and the lack of cerumen were predisposing factors; itching, otalgia, otorrhea and hypoacusis were the symptoms reported by the patients. The most frequently isolated species were C. albicans (30%, C. parapsilosis (20%, A. niger (20%, A. flavus (10%, A. fumigatus (5%, C. tropicalis (5%, Trichosporon asahii (5% and Scedosporium apiospermum (5%. CONCLUSIONS: Otomycosis is endemic in João Pessoa-PB. Clinical exam and mycological studies are important for diagnostic purposes because otomycosis symptoms are not specific.Otomicose é uma infecção fúngica do conduto auditivo externo com poucos estudos sobre sua real frequência no Brasil. OBJETIVO: Avaliar a frequência e características das otomicoses em pacientes com suspeita clínica de otite externa. DESENHO DO ESTUDO: Estudo retrospectivo com corte transversal (2000-2006. MATERIAL E MÉTODOS: 103 pacientes foram atendidos para diagnóstico micológico (exame microscópico direto e cultivo. RESULTADOS: Otomicoses foram diagnosticadas em 19,4% dos pacientes. A idade desses pacientes variou de 2 a 66 anos (média de 23,5 anos e 60% das otomicoses foram observadas em mulheres entre 2 a 20 anos de idade. Otite crônica, antibioticoterapia prévia e ausência de cerume foram os fatores predisponentes e prurido otológico, otalgia

  17. Estudos de Comunidade e ciências sociais no Brasil

    Directory of Open Access Journals (Sweden)

    Nemuel da Silva Oliveira

    2011-12-01

    Full Text Available O objetivo deste artigo é fazer um balanço da literatura sobre os Estudos de Comunidade (EC no Brasil, destacando o contexto intelectual em que foram produzidos e os debates que suscitaram, especialmente entre as décadas de 1940 e 1960. Método de pesquisa em comunidades, oriundo da Antropologia, em investigações sobre o processo de mudança social, os EC estiveram em voga nos Estados Unidos entre os anos 1920 e 1950, tendo papel fundamental na institucionalização das Ciências Sociais no Brasil. Destacamos três aspectos na produção desses estudos no país, iniciando com uma abordagem conceitual: definições, origem e sua relação com temáticas marcantes nos anos 1950. Em seguida, privilegiamos os aspectos relacionados ao papel dos EC na história das Ciências Sociais no Brasil, com destaque para o processo de institucionalização das Ciências Sociais. Por fim, revisitamos os debates que tais estudos geraram entre os cientistas sociais quanto ao padrão de trabalho sociológico a ser desenvolvido naquele momento.The purpose of this article is to examine the literature about Community Studies(CS in Brazil, highlighting their intellectual context of production and the debates evoked by them, especially between the 1940's and 1960's. As a research method arising from Anthropology on communities in social change process, CS was used in United States between 1920's and 1950's, and played a fundamental role in the institutionalization of Social Sciences in Brazil. Three aspects are highlighted on CS production: first, in a conceptual approach, we discuss their definitions, origins and relation to main topics in the 1950's. The second aspect is related to the role of CS in the history of Social Sciences, especially their institutionalization process. By the end, we revisit the debates between social scientists about the sociological work standard to be developed at that time.

  18. História e oralidade nos estudos comunicacionais

    Directory of Open Access Journals (Sweden)

    Juniele Rabêlo Almeida

    2016-05-01

    Full Text Available Concepções, métodos e formas do conhecimento histórico são expressos em diversos estudos na área de comunicação social. Buscamos analisar, na interface história e narrativa oral, aspectos da chamada mediação cultural, na qual a comunicação está para além da condição de canal. Acreditamos que os estudos comunicacionais não recaem, necessariamente, sobre especificidades técnicas, mas sobre a posição que a comunicação assume no campo histórico-cultural. Interações, expressas nos trabalhos de história oral, se configuram (e resultam em processos comunicacionais que indicam construções sócio históricas e diferentes referenciais de pertencimento. Palavras-chave: Estudos comunicacionais, História, Narrativas Orais.   Abstract: Conceptions, methods and historical knowledge forms are expressed in several studies in the area of social communication. We analyze, history and oral narrative interface, called aspects of cultural mediation, in which the communication is in addition to the channel condition. We believe that communication studies do not fall necessarily on technicalities, but on the position that the communication is in the historical-cultural field. Interactions, expressed in the works of oral history, are configured (and result in communication processes that indicate historical social constructions and different frames of belonging. Keywords: communication Studies, History, Oral Narratives.   Resumen: Conceptos, métodos y formas de conocimiento histórico se expresan en varios estudios en el área de la comunicación social. Analizamos, la historia y la interfaz de la narrativa oral, llamados aspectos de mediación cultural, en el que la comunicación es, además de la condición de canal. Creemos que los estudios de comunicación no caen necesariamente en técnicos, sino a la posición de que la comunicación es en el campo histórico-cultural. Interacciones, expresados en las obras de la historia oral, est

  19. Estudos sobre a toxicologia da ε-caprolactama

    Directory of Open Access Journals (Sweden)

    Marcus Vinicius Justo Bomfim

    2009-03-01

    Full Text Available A ε-caprolactama (CAP é um monômero precursor de polímeros denominados nylon 6. Esses polímeros destinam-se à produção de tapetes, vestuário e materiais plásticos tais como equipamentos, sistemas e componentes automotivos, conectores, além de embalagens plásticas. Resíduos de CAP podem migrar de embalagens plásticas de nylon 6 para os alimentos. Diante disso, foi de interesse realizar uma revisão dos efeitos relativos à exposição à CAP e o seu impacto sobre a saúde humana. Estudos epidemiológicos indicam a possibilidade da CAP causar inflamações oculares e cutâneas, além de irritações no sistema respiratório. Pode ocorrer ainda hipotensão, taquicardia, palpitações, rinorréia, ressecamento nasal, efeitos geniturinários e sobre a reprodução como distúrbios nas funções menstrual e ovariana, e complicações no parto; além de problemas neurológicos e hematológicos. Estudos com animais são consistentes com tais relatos. Os estudos de genotoxicidade in vitro e in vivo por via oral e intraperitoneal mostram em sua grande maioria, resultados negativos, bem como ausência de efeitos carcinogênicos em ratos e camundongos e sobre o desenvolvimento e reprodução em ratos e coelhos.ε -Caprolactam (CAP is a precursor monomer of nylon 6 polymers. Nylon 6 is used in the manufacture of carpets, clothes and plastic materials, such as equipment, systems and automotive components, connectors and plastic packaging. CAP residues can migrate from nylon 6 plastic packaging to foods. Given this fact, this review was realized concerning the effects of CAP exposure and its impact on human health. Epidemiological studies indicate that CAP could cause ocular, cutaneous and respiratory irritations, as well as hypotension, tachycardia, palpitations, rhinorrhea, nose dryness, neurological and blood problems, and genitourinary and reproductive effects, such as alterations in ovarian-menstrual functions and pregnancy

  20. Neutron Reflection Study of Surface Adsorption of Fc, Fab, and the Whole mAb.

    Science.gov (United States)

    Li, Zongyi; Li, Ruiheng; Smith, Charles; Pan, Fang; Campana, Mario; Webster, John R P; van der Walle, Christopher F; Uddin, Shahid; Bishop, Steve M; Narwal, Rojaramani; Warwicker, Jim; Lu, Jian Ren

    2017-07-12

    Characterizing the influence of fragment crystallization (Fc) and antigen-binding fragment (Fab) on monoclonal antibody (mAb) adsorption at the air/water interface is an important step to understanding liquid mAb drug product stability during manufacture, shipping, and storage. Here, neutron reflection is used to study the air/water adsorption of a mAb and its Fc and Fab fragments. By varying the isotopic contrast, the adsorbed amount, thickness, orientation, and immersion of the adsorbed layers could be determined unambiguously. While Fc adsorption reached saturation within the hour, its surface adsorbed amount showed little variation with bulk concentration. In contrast, Fab adsorption was slower and the adsorbed amount was concentration dependent. The much higher Fc adsorption, as compared to Fab, was linked to its lower surface charge. Time and concentration dependence of mAb adsorption was dominated by Fab behavior, although both Fab and Fc behaviors contributed to the amount of mAb adsorbed. Changing the pH from 5.5 to 8.8 did not much perturb the adsorbed amount of Fc, Fab, or mAb. However, a small decrease in adsorption was observed for the Fc over pH 8-8.8 and vice versa for the Fab and mAb, consistent with a dominant Fab behavior. As bulk concentration increased from 5 to 50 ppm, the thicknesses of the Fc layers were almost constant at 40 Å, while Fab and mAb layers increased from 45 to 50 Å. These results imply that the adsorbed mAb, Fc, and Fab all retained their globular structures and were oriented with their short axial lengths perpendicular to the interface.

  1. A/B Testing in Improving Conversion on a Website : Case: Sanoma Entertainment Oy

    OpenAIRE

    Arento, Thomas

    2010-01-01

    The purpose of this thesis is to study marketing possibilities of improved conversion rates on websites. The study was made for Sanoma Entertainment Oy’s Gaming & Online unit. The main objective was to explore A/B testing as a tool to improve conversion rates by increasing click-through rates. The secondary objective was to test Google Website Optimizer as an A/B testing tool in comparison to current methods of A/B testing in Sanoma Entertainment Oy. The results of this study will be used as ...

  2. Cationization increases brain distribution of an amyloid-beta protofibril selective F(ab')2 fragment

    OpenAIRE

    Syvänen, Stina; Edén, Desireé; Sehlin, Dag

    2017-01-01

    Antibodies and fragments thereof are, because of high selectivity for their targets, considered as potential therapeutics and biomarkers for several neurological disorders. However, due to their large molecular size, antibodies/fragments do not easily penetrate into the brain. The aim of the present study was to improve the brain distribution via adsorptive-mediated transcytosis of an amyloid-beta (A beta) protofibril selective F(ab')2 fragment (F(ab')2-h158). F(ab')2-h158 was cationized to d...

  3. Ab Initio Calculation of Hyperfine Interaction Parameters: Recent Evolutions, Recent Examples

    International Nuclear Information System (INIS)

    Cottenier, Stefaan; Vanhoof, Veerle; Torumba, Doru; Bellini, Valerio; Cakmak, Mehmet; Rots, Michel

    2004-01-01

    For some years already, ab initio calculations based on Density Functional Theory (DFT) belong to the toolbox of the field of hyperfine interaction studies. In this paper, the standard ab initio approach is schematically sketched. New features, methods and possibilities that broke through during the past few years are listed, and their relation to the standard approach is explained. All this is illustrated by some highlights of recent ab initio work done by the Nuclear Condensed Matter Group at the K.U.Leuven.

  4. PirAB Toxin from Photorhabdus asymbiotica as a Larvicide against Dengue Vectors▿

    OpenAIRE

    Ahantarig, Arunee; Chantawat, Nantarat; Waterfield, Nicholas R.; ffrench-Constant, Richard; Kittayapong, Pattamaporn

    2009-01-01

    We have evaluated Photorhabdus insect-related protein (Pir) from Photorhabdus asymbiotica against dengue vectors. PirAB shows larvicidal activity against both Aedes aegypti and Aedes albopictus larvae but did not affect the Mesocyclops thermocyclopoides predator. PirAB expressed the strongest toxicity compared to PirA, PirB, or the mixture of PirA plus PirB. Whether the presence of an enterobacterial repetitive intergenic consensus sequence in PirAB, but not in PirA, PirB, or the mixture of P...

  5. COMPORTAMENTO DE CONSUMO ECOLOGICAMENTE CONSCIENTE: ESTUDO COMPARATIVO BRASIL X CHINA

    Directory of Open Access Journals (Sweden)

    Tatiana Azevedo Yeh

    2015-12-01

    Full Text Available Esse estudo buscou identificar os fatores que afetam o comportamento de consumo ecologicamente consciente (CCEC. Foram utilizadas duas amostras, uma com chineses e outra com brasileiros. Para análise dos dados utilizou-se técnica estatística descritiva, Teste t e regressão linear multivariada. Demonstrou-se, nas duas amostras, dois construtos comumente significativos para o CCEC: o próprio comportamento verde em si para realização de outros CCEC e os moderadores externos. Identificou-se que a baixa disponibilidade de produtos verdes entre os brasileiros é barreira à ser considerada para o fomento do CCEC no Brasil, que encontra-se na primeira fase de comportamento verde que é a compra. E que os chineses realizam todos os tipos de comportamento: compra, uso e reciclagem.

  6. Estudo FitoquÃmico de Pilocarpus sulcatus Skorupa (Rutaceae)

    OpenAIRE

    AntÃnio HonÃrio de Sousa

    2009-01-01

    O presente trabalho descreve o estudo fitoquÃmico de Pilocarpus sulcatus Skorupa e o levantamento acerca dos metabÃlitos secundÃrios jà isolados do tÃxon Pilocarpus. O trabalho envolveu a extraÃÃo e identificaÃÃo dos constituintes volÃteis das folhas, casca do caule, lenho do caule, cascas das raÃzes e lenho das raÃzes alÃm do isolamento e determinaÃÃo estrutural dos constituintes fixos das folhas e lenho do caule de P. sulcatus. Trata-se de uma espÃcie com descriÃÃo botÃnica recente, ainda s...

  7. Estudo da fonoforese de ciclofenaco dietilamonio em voluntarios sadios

    OpenAIRE

    Claudio Fusaro

    2006-01-01

    Resumo: O transporte transdérmico de substâncias com o ultra-som terapêutico, método denominado fonoforese, oferece muitas vantagens quando comparado as outras vias de administração de drogas. O objetivo deste estudo foi verificar a influência do ultra-som na absorção de diclofenaco dietilamônio (Cataflam Emulgel®, Novartis) após fonoforese em voluntários sadios. Doze voluntários sadios foram submetidos à aplicação tópica de Cataflam Emulgel® em uma área de 150cm2 na região do dorso. No grupo...

  8. Estudo sociocultural alimentício dos alunos da UNILA

    OpenAIRE

    Arcain, Beatriz Mitidiero Stachissini; Reyes, Patricio David; Perez, Cecilio Luis Correa; Campos, Sandra Regina Carneiro de; Brito, Gleisson Alisson Pereira de; Furtado, Danúbia Frasson

    2015-01-01

    Anais do IV Encontro de Iniciação Científica da Unila - “UNILA 5 anos: Integração em Ciência, Tecnologia e Cultura na Tríplice Fronteira” - 05 e 06 de novembro de 2015 – Sessão Ciências Biológicas e Saúde Coletiva : Alterações ambientais e comportamentais podem causar interferências no peso através de alterações da massa adiposa, ocasionadas por modificações dos hábitos alimentares. As modificações do ambiente geram um estresse no indivíduo sendo que, segundo estudos, há diferente...

  9. Estudo das ausências da equipe de enfermagem

    Directory of Open Access Journals (Sweden)

    Janaina Haidê Rodrigues Belem

    1998-12-01

    Full Text Available As ausências dos elementos da equipe de enfermagem comprometem a organização do trabalho causando sobrecarga dessa equipe, e queda na qualidade da assistência de enfermagem. O presente estudo caracteriza o tipo e distribuição das ausências da equipe de enfermagem em um hospital geral de grande porte, propondo um índice de Segurança Técnica para cobertura das ausências a partir da realidade investigada. Foram estudadas 8 tipos de ausências entre previstas e não previstas. O maior número de tipos de ausências encontradas foram aquelas referentes à ausências previstas, em seqüência encontramos licença maternidade representando o maior número de ausências não previstas.

  10. (Sem saber e (com poder nos estudos organizacionais

    Directory of Open Access Journals (Sweden)

    José Henrique de Faria

    Full Text Available Bacon afirma que saber é poder. Tragtenberg contesta. Essa discussão, na contemporaneidade, faz-se mais importante do que se possa imaginar. Por isso, o objetivo central deste artigo é verificar as relações entre saber e poder, na atualidade, levando em consideração o papel da ciência e dos elementos imediatos a ela relacionados. Quanto aos objetivos específicos deste estudo, destacam-se: · compreender o sentido da filosofia e da ciência e suas relações com a ideologia; · verificar como o discurso da neutralidade axiológica da ciência se apresenta como mito da modernidade e como se dá a presença da "fé" na filosofia e na ciência, na contemporaneidade; · refletir sobre a consolidação da ciência como força produtiva e/ou como mercadoria no atual sistema econômico; · destacar a importância do complexo industrial militar como financiador de grande parte dos atuais estudos científicos; · entender o processo de racionalização, avaliando a importância do pragmatismo e da burocracia universitária como afirmação da ciência na atualidade. O texto conclui que tanto é possível a existência de saber como poder (Bacon como a de não saber, mas com poder (Tragtenberg para compreendermos a relação entre saber e poder.

  11. Estudo sobre reciclagem de lâmpadas fluorescentes

    Directory of Open Access Journals (Sweden)

    Danniele Miranda Bacila

    2014-01-01

    Full Text Available Lâmpadas fluorescentes (LF contêm mercúrio em sua composição, um metal pesado que pode causar danos à saúde e ao meio ambiente. As LF são amplamente consumidas no Brasil, porém o descarte correto de LF usadas não é amplamente divulgado e os índices de reciclagem são baixos. O objetivo deste estudo foi demonstrar a relevância do descarte adequado, avaliar as tecnologias de reciclagem e a destinação dos materiais, por meio de estudo comparativo entre Brasil e Alemanha. Através de visitas a recicladoras e análise das tecnologias adotadas nos dois países, foi verificado que no Brasil o vidro é destinado à indústria de cerâmica, enquanto que na Alemanha é destinado à fabricação de tubos para LF. Além disso, foi observado que o mercúrio apresenta diversas possibilidades de uso. Um ponto a ser explorado nos dois países, e de grande potencial para reciclagem, é a recuperação de terras raras do pó fosfórico presente nas LF. Tanto Brasil como Alemanha possuem oportunidades de melhoria na logística reversa de LF, por meio da qual se torna possível elevar os índices de reciclagem e reduzir os impactos ambientais causados pelo descarte inadequado de LF usadas.

  12. Estudo bacteriológico de lesões periapicais

    Directory of Open Access Journals (Sweden)

    ROCHA Márcia Maria de Negreiros Pinto

    1998-01-01

    Full Text Available O tecido perirradicular de 30 casos cirúrgicos foi submetido a exame microbiológico e histopatológico. Foram isoladas 137 cepas bacterianas das 30 lesões periapicais estudadas. Do total de bactérias isoladas, 90 (65,7% foram caracterizadas como anaeróbias estritas, 40 (29,2% como anaeróbias facultativas e 7 (5,1% como aeróbias estritas. Fusobacterium nucleatum, bacilos Gram-negativos pigmentados anaeróbios estritos, Peptostreptococcus sp, Streptococcus mitis e bacilos Gram-positivos não esporulados anaeróbios estritos foram, em ordem decrescente de freqüência, as bactérias mais comumente isoladas das lesões periapicais. A análise histopatológica demonstrou prevalência de granuloma periapical. O estudo de sensibilidade a antimicrobianos foi realizado em 16 cepas de Fusobacterium nucleatum. Os antimicrobianos utilizados foram penicilina, cefoxitina, eritromicina, metronidazol e tetraciclina. Todas as amostras apresentaram suscetibilidade à cefoxitina, tetraciclina e metronidazol; os percentuais de resistência à penicilina e à eritromicina foram 12,5 e 68,8, respectivamente. Os percentuais de resistência de Fusobacterium nucleatum, uma espécie bacteriana importante na patogênese das lesões periapicais, à penicilina e à eritromicina, enfatizam a necessidade de outros estudos de resistência a antimicrobianos de bactérias isoladas em infecções odontogênicas.

  13. Aspectos históricos dos estudos caso-controle

    Directory of Open Access Journals (Sweden)

    Rêgo Marco Antônio Vasconcelos

    2001-01-01

    Full Text Available Este texto apresenta um relato da evolução dos estudos de caso-controle (ECC até o final dos anos 80. A comparação de dois grupos quanto à exposição a um fator de risco é verificada desde o século XVII. A segunda metade do século XIX significou o declínio da Epidemiologia das "populações", e os primeiros ECC só foram realizados na década de 20. O avanço do método ocorreu na segunda metade do século, com destaque para as investigações sobre câncer de pulmão e hábito de fumar. As principais contribuições dos estudiosos do método foram o uso da odds ratio como estimativa do risco relativo; a definição dos aspectos estatísticos da análise de dados de estudos retrospectivos; o cálculo do risco atribuível e da fração etiológica para ECC; e a discussão da essência dos ECC. Os críticos referiam as fragilidades do método e a susceptibilidade aos bias. Conclui-se que os ECC tiveram aplicação crescente nas últimas décadas, sendo utilizados em diversas áreas da epidemiologia, constituindo-se em um importante instrumento para as ações de Saúde Pública.

  14. AN AB INITIO MODEL FOR COSMIC-RAY MODULATION

    Energy Technology Data Exchange (ETDEWEB)

    Engelbrecht, N. E.; Burger, R. A. [Center for Space Research, North-West University, Potchefstroom 2520 (South Africa)

    2013-07-20

    A proper understanding of the effects of turbulence on the diffusion and drift of cosmic rays (CRs) is of vital importance for a better understanding of CR modulation in the heliosphere. This study presents an ab initio model for CR modulation, incorporating for the first time the results yielded by a two-component turbulence transport model. This model is solved for solar minimum heliospheric conditions, utilizing boundary values chosen so that model results are in reasonable agreement with spacecraft observations of turbulence quantities in the solar ecliptic plane and along the out-of-ecliptic trajectory of the Ulysses spacecraft. These results are employed as inputs for modeled slab and two-dimensional (2D) turbulence energy spectra. The modeled 2D spectrum is chosen based on physical considerations, with a drop-off at the very lowest wavenumbers. There currently exist no models or observations for the wavenumber where this drop-off occurs, and it is considered to be the only free parameter in this study. The modeled spectra are used as inputs for parallel mean free path expressions based on those derived from quasi-linear theory and perpendicular mean free paths from extended nonlinear guiding center theory. Furthermore, the effects of turbulence on CR drifts are modeled in a self-consistent way, also employing a recently developed model for wavy current sheet drift. The resulting diffusion and drift coefficients are applied to the study of galactic CR protons and antiprotons using a 3D, steady-state CR modulation code, and sample solutions in fair to good agreement with multiple spacecraft observations are presented.

  15. Adjuvant Ab Interno Tumor Treatment After Proton Beam Irradiation.

    Science.gov (United States)

    Seibel, Ira; Riechardt, Aline I; Heufelder, Jens; Cordini, Dino; Joussen, Antonia M

    2017-06-01

    This study was performed to show long-term outcomes concerning globe preservation in uveal melanoma patients after proton beam therapy with the main focus on outcomes according to different adjuvant ab interno surgical procedures. Retrospective cohort study. All patients treated with primary proton beam therapy for choroidal or ciliary body melanoma between June 1998 and June 2015 were included. A total of 2499 patients underwent primary proton beam therapy, with local tumor control and globe preservation rates of 95.9% and 94.8% after 5 years, respectively. A total of 110 (4.4%) patients required secondary enucleation. Unresponsive neovascular glaucoma was the leading cause of secondary enucleation in 78 of the 2499 patients (3.1%). The 5-year enucleation-free survival rate was 94.8% in the endoresection group, 94.3% in the endodrainage group, and 93.5% in the comparator group. The log-rank test showed P = .014 (comparator group vs endoresection group) and P = .06 (comparator group vs endodrainage-vitrectomy group). Patients treated with endoresection or endodrainage-vitrectomy developed less radiation retinopathy (30.5% and 37.4% after 5 years, P = .001 and P = .048 [Kaplan-Meier], respectively) and less neovascular glaucoma (11.6% and 21.3% after 5 years, P = .001 and P = .01 [Kaplan-Meier], respectively) compared with the comparator group (52.3% radiation retinopathy and 57.8% neovascular glaucoma after 5 years). This study suggests that in larger tumors the enucleation and neovascular glaucoma rates might be reduced by adjuvant surgical procedures. Although endoresection is the most promising adjuvant treatment option, the endodrainage-vitrectomy is recommended in patients who are ineligible for endoresection. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. TH-AB-BRB-02: ET-Reloaded

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Q. [Duke University Medical Center (United States)

    2016-06-15

    CA183390, NIH R01CA188300, Varian Medical Systems V. Yu, Varian Medical Systems, AAPM Summer Undergraduate Fellowship, NSF graduate fellowship S. Nill, Elekta AB. Cancer Research UK under Programme C33589/A19727, NIHR Biomedical Research Centre at The Royal Marsden and The Institute of Cancer Research.

  17. The research of radioimmunoassay using double abs for bradykinin

    International Nuclear Information System (INIS)

    Cheng Jinxuan; Wang Li; Duan Jinhong; Han Fengyun; Liu Jinsheng; Wang Zhengang; Ren Minfeng

    1996-01-01

    Bradykinin (BK) is a potent vasodilative substance, and plays great physiological and pathological roles in animals and human beings. To measure the quantity of BK, the radioimmunoassay (RIA) has been devised, but the traditional RIA method has certain defects, such as presence of numerous interfering factors and errors and time consuming. Now, we produce anti-BK serum in rabbits by using BK-ovalbumin conjugate as an immunogen, and the 125 I labeled Tyr 8 -BK by using a modified chloramine-T method. High specific activity has been obtained after purification with DEAE-Sephadex A-25 column chromatography. We use the donkey anti-rabbit Ab and PEG 6000 to separate the bound from the free 125 I-tyr 8 -BK. The limitation range of standard curve is from 25 to 1600 pg, NSB is 3.1%, affinity constant (K) is 0.8 x 10 10 L/mol, and there is no significant interference with other biological BK analogues. The blood samples are treated by adding Polybrene (inhibitor) and PEG 6000 to deposit the big serum proteins in order to reduce the disturbing substances. This method has been shown to be a sensitive, specific, reliable, simple and convenient measure of the serum BK level. By this method, the serum BK quantities in men, women and rats are respectively 1584 +- 347 pg/ml, 1642 +- 302 pg/ml and 1805 +- 225 pg/ml, and recycling rate is 95%, the inter-group CV is 5.0% and outer-group CV = 9.2%

  18. TH-AB-BRB-02: ET-Reloaded

    International Nuclear Information System (INIS)

    Wu, Q.

    2016-01-01

    CA183390, NIH R01CA188300, Varian Medical Systems V. Yu, Varian Medical Systems, AAPM Summer Undergraduate Fellowship, NSF graduate fellowship S. Nill, Elekta AB. Cancer Research UK under Programme C33589/A19727, NIHR Biomedical Research Centre at The Royal Marsden and The Institute of Cancer Research.

  19. TH-AB-BRB-03: 4n Radiotherapy

    International Nuclear Information System (INIS)

    Sheng, K.

    2016-01-01

    CA183390, NIH R01CA188300, Varian Medical Systems V. Yu, Varian Medical Systems, AAPM Summer Undergraduate Fellowship, NSF graduate fellowship S. Nill, Elekta AB. Cancer Research UK under Programme C33589/A19727, NIHR Biomedical Research Centre at The Royal Marsden and The Institute of Cancer Research.

  20. Cosmic-ray modulation: an ab initio approach

    Energy Technology Data Exchange (ETDEWEB)

    Engelbrecht, N.E.; Burger, R.A., E-mail: 12580996@nwu.ac.za [Center for Space Research, North-West University, Potchefstroom (South Africa)

    2014-07-01

    A better understanding of cosmic-ray modulation in the heliosphere can only be gained through a proper understanding of the effects of turbulence on the diffusion and drift of cosmic rays. We present an ab initio model for cosmic-ray modulation, incorporating for the first time the results yielded by a two-component turbulence transport model. This model is solved for periods of minimum solar activity, utilizing boundary values chosen so that model results are in fair to good agreement with spacecraft observations of turbulence quantities, not only in the solar ecliptic plane but also along the out-of-ecliptic trajectory of the Ulysses spacecraft. These results are employed as inputs for modelled slab and 2D turbulence energy spectra. The latter spectrum is chosen based on physical considerations, with a drop-off at the very lowest wavenumbers commencing at the 2D outerscale. There currently exist no models or observations for this quantity, and it is the only free parameter in this study. The modelled turbulence spectra are used as inputs for parallel mean free path expressions based on those derived from quasi-linear theory and perpendicular mean free paths from extended nonlinear guiding center theory. Furthermore, the effects of turbulence on cosmic-ray drifts are modelled in a self-consistent way, employing a recently developed model for drift along the wavy current sheet. The resulting diffusion coefficients and drift expressions are applied to the study of galactic cosmic-ray protons and antiprotons using a three dimensional, steady-state cosmic-ray modulation code, and sample solutions in fair agreement with multiple spacecraft observations are presented. (author)

  1. Cosmic-ray modulation: an ab initio approach

    International Nuclear Information System (INIS)

    Engelbrecht, N.E.; Burger, R.A.

    2014-01-01

    A better understanding of cosmic-ray modulation in the heliosphere can only be gained through a proper understanding of the effects of turbulence on the diffusion and drift of cosmic rays. We present an ab initio model for cosmic-ray modulation, incorporating for the first time the results yielded by a two-component turbulence transport model. This model is solved for periods of minimum solar activity, utilizing boundary values chosen so that model results are in fair to good agreement with spacecraft observations of turbulence quantities, not only in the solar ecliptic plane but also along the out-of-ecliptic trajectory of the Ulysses spacecraft. These results are employed as inputs for modelled slab and 2D turbulence energy spectra. The latter spectrum is chosen based on physical considerations, with a drop-off at the very lowest wavenumbers commencing at the 2D outerscale. There currently exist no models or observations for this quantity, and it is the only free parameter in this study. The modelled turbulence spectra are used as inputs for parallel mean free path expressions based on those derived from quasi-linear theory and perpendicular mean free paths from extended nonlinear guiding center theory. Furthermore, the effects of turbulence on cosmic-ray drifts are modelled in a self-consistent way, employing a recently developed model for drift along the wavy current sheet. The resulting diffusion coefficients and drift expressions are applied to the study of galactic cosmic-ray protons and antiprotons using a three dimensional, steady-state cosmic-ray modulation code, and sample solutions in fair agreement with multiple spacecraft observations are presented. (author)

  2. Lithium Insertion In Silicon Nanowires: An ab Initio Study

    KAUST Repository

    Zhang, Qianfan

    2010-09-08

    The ultrahigh specific lithium ion storage capacity of Si nanowires (SiNWs) has been demonstrated recently and has opened up exciting opportunities for energy storage. However, a systematic theoretical study on lithium insertion in SiNWs remains a challenge, and as a result, understanding of the fundamental interaction and microscopic dynamics during lithium insertion is still lacking. This paper focuses on the study of single Li atom insertion into SiNWs with different sizes and axis orientations by using full ab initio calculations. We show that the binding energy of interstitial Li increases as the SiNW diameter grows. The binding energies at different insertion sites, which can be classified as surface, intermediate, and core sites, are quite different. We find that surface sites are energetically the most favorable insertion positions and that intermediate sites are the most unfavorable insertion positions. Compared with the other growth directions, the [110] SiNWs with different diameters always present the highest binding energies on various insertion locations, which indicates that [110] SiNWs are more favorable by Li doping. Furthermore, we study Li diffusion inside SiNWs. The results show that the Li surface diffusion has a much higher chance to occur than the surface to core diffusion, which is consistent with the experimental observation that the Li insertion in SiNWs is layer by layer from surface to inner region. After overcoming a large barrier crossing surface-to-intermediate region, the diffusion toward center has a higher possibility to occur than the inverse process. © 2010 American Chemical Society.

  3. TH-AB-BRB-03: 4n Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, K. [UCLA School of Medicine (United States)

    2016-06-15

    CA183390, NIH R01CA188300, Varian Medical Systems V. Yu, Varian Medical Systems, AAPM Summer Undergraduate Fellowship, NSF graduate fellowship S. Nill, Elekta AB. Cancer Research UK under Programme C33589/A19727, NIHR Biomedical Research Centre at The Royal Marsden and The Institute of Cancer Research.

  4. An ab initio study of plutonium oxides surfaces

    International Nuclear Information System (INIS)

    Jomard, G.; Bottin, F.; Amadon, B.

    2007-01-01

    By means of first-principles calculations, we have studied the atomic structure as well as the thermodynamic stability of various plutonium dioxide surfaces in function of their environment (in terms of oxygen partial pressure and temperature). All these simulations have been performed with the ABINIT code. It is well known that DFT fails to describe correctly plutonium-based materials since 5f electrons in such systems are strongly correlated. In order to go beyond DFT, we have treated PuO 2 and β-Pu 2 O 3 in a DFT+U framework. We show that the couple of parameters (U,J) that works well for pure Pu is also well designed for describing ground state (GS) properties of these two oxides. The major improvement with respect with DFT is that we are able to predict an insulating GS in agreement with experiments. The presence of a gap in the DOS (Density of States) of plutonium oxides should play a significant role in the predicted surface reactivity. However, performing DFT+U calculations on surfaces of plutonium oxide from scratch was too ambitious. That is why we decided, as a first step, to study the stability of the (100), (110) and (111) surfaces of PuO 2 in a DFT-GGA framework. For each of these orientations, we considered various terminations. These ab initio results have been introduced in a thermodynamic model which allows us to predict the relative stability of the different terminations as a function of temperature and oxygen partial pressure (p O 2 ). We conclude that at room temperature and for p O 2 ∼10 atm., the polar O 2 -(100) termination is favoured. The stabilization of such a polar stoichiometric surface is surprising and should be confirmed by DFT+U calculations before any final conclusion. (authors)

  5. Rapid Solidification of AB{sub 5} Hydrogen Storage Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gulbrandsen-Dahl, Sverre

    2002-01-01

    This doctoral thesis is concerned with rapid solidification of AB{sub 5} materials suitable for electrochemical hydrogen storage. The primary objective of the work has been to characterise the microstructure and crystal structure of the produced AB{sub 5} materials as a function of the process parameters, e.g. the cooling rate during rapid solidification, the determination of which has been paid special attention to. The thesis is divided into 6 parts, of which Part I is a literature review, starting with a short presentation of energy storage alternatives. Then a general review of metal hydrides and their utilisation as energy carriers is presented. This part also includes more detailed descriptions of the crystal structure, the chemical composition and the hydrogen storage properties of AB{sub 5} materials. Furthermore, a description of the chill-block melt spinning process and the gas atomisation process is given. In Part II of the thesis a digital photo calorimetric technique has been developed and applied for obtaining in situ temperature measurements during chill-block melt spinning of a Mm(NiCoMnA1){sub 5} hydride forming alloy (Mm = Mischmetal of rare earths). Compared with conventional colour transmission temperature measurements, this technique offers a special advantage in terms of a high temperature resolutional and positional accuracy, which under the prevailing experimental conditions were found to be {+-}29 K and {+-} 0.1 mm, respectively. Moreover, it is shown that the cooling rate in solid state is approximately 2.5 times higher than that observed during solidification, indicating that the solid ribbon stayed in intimate contact with the wheel surface down to very low metal temperatures before the bond was broken. During this contact period the cooling regime shifted from near ideal in the melt puddle to near Newtonian towards the end, when the heat transfer from the solid ribbon to the wheel became the rate controlling step. In Part III of the

  6. A cross-metathesis approach to the stereocontrolled synthesis of the AB ring segment of ciguatoxin

    OpenAIRE

    Kadota, Isao; Abe, Takashi; Uni, Miyuki; Takamura, Hiroyoshi; Yamamoto, Yoshinori

    2008-01-01

    Synthesis of the AB ring segments of ciguatoxin is described. The present synthesis includes a Lewis acid mediated cyclization of allylstannane with aldehyde, cross-metathesis reaction introducing the side chain, and Grieco-Nishizawa dehydration on the A ring.

  7. Domino Wittig Diels-Alder reaction: An expeditious entry into the AB ring system of furanosesquiterpenes

    Digital Repository Service at National Institute of Oceanography (India)

    Patre, R.E.; Gawas, S.; Sen, S.; Parameswaran, P.S.; Tilve, S.G.

    A domino Wittig Diels - Alder reaction has been employed in delineating a short and flexible synthetic stratagem for ready access to the AB ring system and the tricyclic framework of furanosesquiterpenes, such as the bioactive natural products...

  8. Transconjunctival orbital decompression in Graves' ophthalmopathy: lateral wall approach ab interno

    NARCIS (Netherlands)

    A.D.A. Paridaens (Dion); K. Verhoeff; D. Bouwens; W.A. van den Bosch (Willem)

    2000-01-01

    textabstractAIMS: A modified surgical technique is described to perform a one, two, or three wall orbital decompression in patients with Graves' ophthalmopathy. METHODS: The lateral wall was approached ab interno through a "swinging eyelid" approach (lateral canthotomy

  9. Isolation and Characterization of a Virulent Bacteriophage AB1 of Acinetobacter baumannii

    Directory of Open Access Journals (Sweden)

    Jia Shiru

    2010-04-01

    Full Text Available Abstract Background Acinetobacter baumannii is an emerging nosocomial pathogen worldwide with increasing prevalence of multi-drug and pan-drug resistance. A. baumannii exists widely in natural environment, especially in health care settings, and has been shown difficult to be eradicated. Bacteriophages are often considered alternative agent for controlling bacterial infection and contamination. In this study, we described the isolation and characterization of one virulent bacteriophage AB1 capable of specifically infecting A. baumannii. Results A virulent bacteriophage AB1, specific for infecting a clinical strain A. baumannii KD311, was first isolated from marine sediment sample. Restriction analysis indicated that phage AB1 was a dsDNA virus with an approximate genome size of 45.2 kb to 46.9 kb. Transmission electron microscopy showed that phage AB1 had an icosahedral head with a non-contractile tail and collar or whisker structures, and might be tentatively classified as a member of the Siphoviridae family. Proteomic pattern of phage AB1, generated by SDS-PAGE using purified phage particles, revealed five major bands and six minor bands with molecular weight ranging from 14 to 80 kilo-dalton. Also determined was the adsorption rate of phage AB1 to the host bacterium, which was significantly enhanced by addition of 10 mM CaCl2. In a single step growth test, phage AB1 was shown having a latent period of 18 minutes and a burst size of 409. Moreover, pH and thermal stability of phage AB1 were also investigated. At the optimal pH 6.0, 73.2% of phages survived after 60 min incubation at 50°C. When phage AB1 was used to infect four additional clinical isolates of A. baumannii, one clinical isolate of Stenotrophomonas maltophilia, and Pseudomonas aeruginosa lab strains PAK and PAO1, none of the tested strains was found susceptible, indicating a relatively narrow host range for phage AB1. Conclusion Phage AB1 was capable of eliciting efficient lysis

  10. A Kine-chemical Investigation of the AB Dor Moving Group "Stream"

    Science.gov (United States)

    Barenfeld, Scott A.; Bubar, Eric J.; Mamajek, Eric E.; Young, Patrick A.

    2013-03-01

    The AB Dor Moving Group consists of a "nucleus" of ~10 stars at d ~= 20 pc, along with dozens of purported "stream" members distributed across the sky. We perform a chemical and kinematic analysis of a subsample of AB Dor stream stars to test whether they constitute a physical stellar group. We use the NEMO Galactic kinematic code to investigate the orbits of the stream members, and perform a chemical abundance analysis using high resolution spectra taken with the Magellan Clay 6.5 m telescope. Using a χ2 test with the measured abundances for 10 different elements, we find that only half of the purported AB Dor stream members could possibly constitute a statistically chemically homogeneous sample. Some stream members with three-dimensional velocities were hundreds of parsecs from the AB Dor nucleus ~108 yr ago, and hence were unlikely to share a common origin. We conclude that the published lists of AB Dor moving group stream members are unlikely to represent the dispersed remnant of a single star formation episode. A subsample of the stream stars appears to be both statistically chemically homogeneous and in the vicinity of the AB Dor nucleus at birth. Their mean metallicity is [Fe/H] = 0.02 ± 0.02 dex, which we consider representative for the AB Dor group. Finally, we report a strong lower limit on the age of the AB Dor nucleus of >110 Myr based on the pre-main sequence contraction times for K-type members which have reached the main sequence.

  11. Time-resolved photoelectron spectroscopy and ab initio multiple spawning studies of hexamethylcyclopentadiene

    DEFF Research Database (Denmark)

    Wolf, T. J. A.; Kuhlman, Thomas Scheby; Schalk, O.

    2014-01-01

    Time-resolved photoelectron spectroscopy and ab initio multiple spawning were applied to the ultrafast non-adiabatic dynamics of hexamethylcyclopentadiene. The high level of agreement between experiment and theory associates wavepacket motion with a distinct degree of freedom.......Time-resolved photoelectron spectroscopy and ab initio multiple spawning were applied to the ultrafast non-adiabatic dynamics of hexamethylcyclopentadiene. The high level of agreement between experiment and theory associates wavepacket motion with a distinct degree of freedom....

  12. Permanent and induced dipole requirements in ab initio calculations of electron affinities of polar molecules

    International Nuclear Information System (INIS)

    Garrett, W.R.

    1979-01-01

    Through the use of a molecular pseudopotential method, we determine the a approximate magnitudes of errors that result when electron affinity determinations of polar negative ions are made through ab initio calculations in which the use of a given basis set yields inappropriate values for permanent and induced dipole moments of the neutral molecule. These results should prove useful in assessing the adequacy of basis sets in ab initio calculations of molecular electron affinities for simple linear polar molecules

  13. MODELLING AND VALIDATION OF A TESTING TRAILER FOR ABS AND TYRE INTERACTION ON ROUGH TERRAIN

    OpenAIRE

    Žuraulis, Vidas; van der Merwe, Nico A.; Scholtz, Odette; Els, P. Schalk

    2017-01-01

    The main purpose of a vehicle anti-lock braking system (ABS) is to prevent the tyres from locking-up in order to brake efficiently whilst maintaining steering control and stability. Sport utility vehicles (SUV) are designed to drive on various roads under different driving conditions, making it challenging to identify optimal operating conditions for ABS algorithms to be implemented. This paper describes the development and modelling of a testing trailer that is designed to benefit the res...

  14. Ab Initio Molecular Dynamics Simulations of Furfural at the Liquid-Solid Interface

    OpenAIRE

    Sanwu Wang; Hongli Dang; Wenhua Xue; Darwin Shields; Xin Liu; Friederike C. Jentoft; Daniel E. Resasco

    2013-01-01

    The bonding configuration and the heat of adsorption of a furfural molecule on the Pd(111) surface were determined by ab initio density-functional-theory calculations. The dynamics of pure liquid water, the liquid-solid interface formed by liquid water and the Pd(111) surface, as well as furfural at the water-Pd interface, were investigated by ab initio molecular dynamics simulations at finite temperatures. Calculations and simulations suggest that the bonding configurati...

  15. Comparison between the harris and ab expressions for the description of nuclear superdeformed rotational bands

    International Nuclear Information System (INIS)

    Hu Zuoxian; Zeng Jinyan

    1998-01-01

    The superdeformed rotational bands in the A ≅3D 190 region are systematically analyzed using the Harris two-parameter formula and the ab expression, respectively. Similar to the situations in normally deformed nuclei, there exist obvious and systematic deviation of Harris formula from the experiments. In contrast, the prediction of ab formula is very close to experiments, and can be conveniently used for the description of nuclear superdeformed bands

  16. URHEILUN SPONSOROINTI JA LUMILAUTAILU : FOREX Bank Ab:n mahdollisuudet lumilautailun sponsorointiin

    OpenAIRE

    Autio, Suvi

    2011-01-01

    FOREX Bank Ab on Pohjoismaiden suurin valuutanvaihtoon erikoistunut yritys. FOREXin liikeideana on tarjota maasta lähteville ja maahan saapuville matkailijoille valuuttaa joustaviin kellonaikoihin, keskeisillä paikoilla, sekä kilpailukykyisillä kursseilla ja toimitusmaksuilla. Opinnäytetyön aiheena oli urheilun sponsorointi ja lumilautailu. Opinnäytetyön tarkoituksena oli selvittää FOREX Bank Ab:n sponsoroinnin nykytilaa ja lumilautailun sopivuutta FOREXin sponsorointikohteeksi. Teoriaosu...

  17. Dynamics of immature mAb glycoform secretion during CHO cell culture

    DEFF Research Database (Denmark)

    Jimenez del Val, Ioscani; Fan, Yuzhou; Weilguny, Dietmar

    2016-01-01

    Ensuring consistent glycosylation-associated quality of therapeutic monoclonal antibodies (mAbs) has become a priority in pharmaceutical bioprocessing given that the distribution and composition of the carbohydrates (glycans) bound to these molecules determines their therapeutic efficacy and immu......Ensuring consistent glycosylation-associated quality of therapeutic monoclonal antibodies (mAbs) has become a priority in pharmaceutical bioprocessing given that the distribution and composition of the carbohydrates (glycans) bound to these molecules determines their therapeutic efficacy...

  18. Production and characterization of anti-human IgG F(ab')2 antibody fragment.

    Science.gov (United States)

    Valedkarimi, Zahra; Nasiri, Hadi; Aghebati-Maleki, Leili; Abdolalizadeh, Jalal; Esparvarinha, Mojghan; Majidi, Jafar

    2018-04-10

    In present study an optimized protocol for the separation of antibodies into antigen-binding fragments F(ab')2 using pepsin digestion was investigated. The production of these fragments is a consequential step in the development of medical research, treatment and diagnosis. For production of polyclonal antibody rabbit received antigen in four steps. The rabbit serum at 1/128000 dilution showed high absorbance in reaction with human IgG at the designed ELISA method. Rabbit IgG was purified by Ion-Exchange Chromatography (IEC) method. Purity was assessed by SDS-PAGE method. In non-reduced condition only one band was seen in about 150 kDa MW position and in reduced form, two bands were seen in 50 and 25 kDa MW positions. Rabbit IgG was digested by pepsin enzyme. The antibody fragments solution was applied to Gel filtration column to isolate the F(ab')2. Non-reduced SDS-PAGE for determining the purity of F(ab')2 fragment resulted in one band in 100 kDa corresponds to F(ab')2 fragment and a band in 150 kDa MW position corresponds to undigested IgG antibodies. The activities of FITC conjugated F(ab')2 fragment and commercial ones were compared using flowcytometry method. The activity results implied that the FITC conjugated- anti human F(ab')2 fragment worked as efficiently as the commercial one.

  19. Unique synergism in flame retardancy in ABS based composites through blending PVDF and halloysite nanotubes

    Science.gov (United States)

    Remanan, Sanjay; Sharma, Maya; Jayashree, Priyadarshini; Parameswaranpillai, Jyotishkumar; Fabian, Thomas; Shih, Julie; Shankarappa, Prasad; Nuggehalli, Bharath; Bose, Suryasarathi

    2017-06-01

    This study demonstrates flame retardant materials designed using bi-phasic polymer blends of acrylonitrile butadiene styrene (ABS) and polyvinylidene fluoride (PVDF) containing halloysite nanotubes (HNTs) and Cloisite 30B nanoclay. The prepared blends with and without nanoparticles were extensively characterized. The nanoparticles were added in different weight concentrations to improve the flame retardancy. It was observed that prepared ABS/PVDF blends showed better flame retardancy than ABS based composites. The flame resistance was further improved by the addition of nanoparticles in the blends. The microscale combustion calorimetry (MCC) test showed better flame resistance in ABS/PVDF blends filled with 5 wt% HNTs than other composites. The total heat release of ABS/PVDF blend filled with 5 wt% HNTs decreased by 31% and also the heat of combustion decreased by 26% as compared to neat ABS. When compared with nanoparticles, the addition of PVDF reduced the peak heat release rate (PHRR) and increased the char residue more effectively. A synergistic improvement was observed from both PVDF and HNTs on the flame resistance properties.

  20. Evaluation of tumor targeting with radiolabeled F(ab2 fragment of a humanized monoclonal antibody

    Directory of Open Access Journals (Sweden)

    "Babaei MH

    2002-08-01

    Full Text Available Humanized monoclonal antibody U36 and its F(ab'2 fragment, radio labeled with 125I, were tested for tumor localization in nude mice bearing a squamous cell carcinoma xenograft line derived from a head and neck carcinoma. Monoclonal antibody IgG or F(ab'2 fragment were injected in parallel and at days 1, 2 and 3, mice were dissected for determination of isotope biodistribution. IgG as well as F(ab'2 showed highly specific localization in tumor tissue. The mean tumor uptake (n=3 is expressed as the percentage of the injected dose per gram of tumor tissue (%ID/g. %ID/g of IgG was 11.7% at day 1 and decreased to 10.9% at day 3 whereas %ID/g of F(ab'2 was 2.9% at day 1 and decreased on following days. Tumor to blood ratios (T/B at day 1 were 0.86 for IgG and 1.32 for F(ab'2 and reached a maximum at day 3 with values of 4.41 and 1.84 respectively. These findings suggest that the superior tumor to non-tumor ratios in the day of 1 render the F(ab'2 fragment more qualified for specific targeting radioisotopes to tumor xenografts in this exprimental setting.

  1. Studies of the distribution of intrathecally injected 125I-tetanus antitoxin-F(ab')2

    International Nuclear Information System (INIS)

    Hanauske, A.R.

    1981-01-01

    Overall F(ab') 2 and antitetanus-f(ab') 2 - fragments were labelled with 125 I and injected i.th. into normal juvenile cats and adult rats. One group of rats was normal; in the other, unilateral local tetanus had been induced by injection of tetanus toxin into a M. gastrocnemius. The animals were sacrificed 24 h after the i.th. injection, and tissue samples were taken for histoautoradiography. 125 I-antitetanus-F(ab') 2 permeated into the extracellular space of the spinal cord, roots, and ganglia but not into the neuronal intracellular space. 125 I-overall-F(ab') showed identical permeation behaviour. 125 I-antitetanus-F(ab') 2 reacted with tetanus toxin issuing from the motoneurons after i.th. injection, forming an immunocomplex around the motorneurons. The immunocomplex was not formed around pseudo-unipolar ganglian cells in the spinal ganglia even though some of the ganglian cells contained tetanus toxin, and 125 I-antitetanus-F(ab') 2 was present in the extracellular space. As an explanation, it was suggested that tetanus toxin does not permeate into the extracellular space through the membrane of the pseudo-unipolar ganglian cells so that immune reactions will not occur. These findings help to explain the widely divergent results of tetanus therapy by means of i.th. injection of tetanus antitoxin. Recommendations for future therapy measures are derived from the findings. (orig./MG) [de

  2. Clinical significance of detection of GAD-Ab, ICA and IAA in patients with diabetes mellitus

    International Nuclear Information System (INIS)

    Zhou Jinhong; Liu Zhenzong; Wang Huimin

    2006-01-01

    To explore value of combined detection of glutamic acid decarboxylase antibody(GAD-Ab), islet cell antibody (ICA) and insulin autoantibody (IAA) in patients with diabetes mellitus (DM). Serum GAD-Ab, ICA and IAA were detected by chemiluminescent immunoassay and RIA in 46 of type 1 diabetes mellitus (1 DM), 78 of 2 DM respectively, and in 50 nondiabetic subjects as control group, and analysed according to the positive rates of different groups. Results showed that the positive rate of GAD-Ab was 67.39%, ICA 39.73%, IAA 23.91% in 1 DM,and that of GAD-Ab was 8.97%, ICA 15.39%, IAA 10.26% in 2 DM respectively. The positive rate of combined detection of GAD-Ab, ICA and IAA was 91.30% in patients with 1 DM, and 29.49% which was higher than that in control group (P<0.01). The detection of serum GAD-Ab,ICA and IAA might be regarded as clinical significance for classification, treatment and predict prognosis of DM. (authors)

  3. Formation of reflective and conductive silver film on ABS surface via covalent grafting and solution spray

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Dexin; Zhang, Yan [School of Mechanical and Automotive Engineering, South China University of Technology, 381 Wushan, Guangzhou 510640 (China); Bessho, Takeshi [Higashifuji Technical Center, Toyota Motor Corporation, 1200 Mishuku, Susono, Shizuoka 410-1193 (Japan); Kudo, Takahiro; Sang, Jing; Hirahara, Hidetoshi; Mori, Kunio [Faculty of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Kang, Zhixin, E-mail: zxkang@scut.edu.cn [School of Mechanical and Automotive Engineering, South China University of Technology, 381 Wushan, Guangzhou 510640 (China)

    2015-09-15

    Highlights: • A pure and homogenous silver film was deposited by spray-style plating technique. • The mechanism of covalent bonding between coating and substrate was studied. • The silver coating is highly reflective and conductive. • UV light was used to activate the ABS surface with triazine azide derivative. - Abstract: Conductive and reflective silver layers on acrylonitrile butadiene styrene (ABS) plastics have been prepared by photo grafting of triazine azides upon ultraviolet activation, self-assembling of triazine dithiols and silver electroless plating by solution spray based on silver mirror reaction. The as-prepared silver film exhibited excellent adhesion with ABS owing to covalent bonds between coating and substrate, and the detailed bonding mechanism have been investigated by X-ray photoelectron spectroscopy (XPS). X-ray diffraction (XRD) result revealed that silver film on ABS was pure and with a nanocrystalline structure. Atomic force microscope (AFM) analysis demonstrated that massive silver particles with sizes varying from 80 to 120 nm were deposited on ABS and formed a homogenous and smooth coating, resulting in highly reflective surface. Furthermore, silver maintained its unique conductivity even as film on ABS surface in term of four-point probe method.

  4. Formation of reflective and conductive silver film on ABS surface via covalent grafting and solution spray

    International Nuclear Information System (INIS)

    Chen, Dexin; Zhang, Yan; Bessho, Takeshi; Kudo, Takahiro; Sang, Jing; Hirahara, Hidetoshi; Mori, Kunio; Kang, Zhixin

    2015-01-01

    Highlights: • A pure and homogenous silver film was deposited by spray-style plating technique. • The mechanism of covalent bonding between coating and substrate was studied. • The silver coating is highly reflective and conductive. • UV light was used to activate the ABS surface with triazine azide derivative. - Abstract: Conductive and reflective silver layers on acrylonitrile butadiene styrene (ABS) plastics have been prepared by photo grafting of triazine azides upon ultraviolet activation, self-assembling of triazine dithiols and silver electroless plating by solution spray based on silver mirror reaction. The as-prepared silver film exhibited excellent adhesion with ABS owing to covalent bonds between coating and substrate, and the detailed bonding mechanism have been investigated by X-ray photoelectron spectroscopy (XPS). X-ray diffraction (XRD) result revealed that silver film on ABS was pure and with a nanocrystalline structure. Atomic force microscope (AFM) analysis demonstrated that massive silver particles with sizes varying from 80 to 120 nm were deposited on ABS and formed a homogenous and smooth coating, resulting in highly reflective surface. Furthermore, silver maintained its unique conductivity even as film on ABS surface in term of four-point probe method

  5. Cry1Ab protein from Bt transgenic rice does not residue in rhizosphere soil

    International Nuclear Information System (INIS)

    Wang Haiyan; Ye Qingfu; Wang Wei; Wu Licheng; Wu Weixiang

    2006-01-01

    Expression of Cry1Ab protein in Bt transgenic rice (KMD) and its residue in the rhizosphere soil during the whole growth in field, as well as degradation of the protein from KMD straw in five soils under laboratory incubation were studied. The residue of Cry1Ab protein in KMD rhizosphere soil was undetectable (below the limit of 0.5 ng/g air-dried soil). The Cry1Ab protein contents in the shoot and root of KMD were 3.23-8.22 and 0.68-0.89 μg/g (fresh weight), respectively. The half-lives of the Cry1Ab protein in the soils amended with KMD straw (4%, w/w) ranged from 11.5 to 34.3 d. The residence time of the protein varied significantly in a Fluvio-marine yellow loamy soil amended with KMD straw at the rate of 3, 4 and 7%, with half-lives of 9.9, 13.8 and 18 d, respectively. In addition, an extraction method for Cry1Ab protein in soil was developed, with extraction efficiencies of 46.4-82.3%. - Cry1Ab protein was not detected in the rhizosphere soil of field-grown Bt transgenic rice

  6. Stacking stability of MoS2 bilayer: An ab initio study

    International Nuclear Information System (INIS)

    Tao Peng; Guo Huai-Hong; Yang Teng; Zhang Zhi-Dong

    2014-01-01

    The study of the stacking stability of bilayer MoS 2 is essential since a bilayer has exhibited advantages over single layer MoS 2 in many aspects for nanoelectronic applications. We explored the relative stability, optimal sliding path between different stacking orders of bilayer MoS 2 , and (especially) the effect of inter-layer stress, by combining first-principles density functional total energy calculations and the climbing-image nudge-elastic-band (CI-NEB) method. Among five typical stacking orders, which can be categorized into two kinds (I: AA, AB and II: AA', AB', A'B), we found that stacking orders with Mo and S superposing from both layers, such as AA' and AB, is more stable than the others. With smaller computational efforts than potential energy profile searching, we can study the effect of inter-layer stress on the stacking stability. Under isobaric condition, the sliding barrier increases by a few eV/(ucGPa) from AA' to AB', compared to 0.1 eV/(ucGPa) from AB to [AB]. Moreover, we found that interlayer compressive stress can help enhance the transport properties of AA'. This study can help understand why inter-layer stress by dielectric gating materials can be an effective means to improving MoS 2 on nanoelectronic applications. (condensed matter: structural, mechanical, and thermal properties)

  7. An ab initio study of plutonium oxides surfaces; Etude ab initio des surfaces d'oxydes de Pu

    Energy Technology Data Exchange (ETDEWEB)

    Jomard, G.; Bottin, F.; Amadon, B

    2007-07-01

    By means of first-principles calculations, we have studied the atomic structure as well as the thermodynamic stability of various plutonium dioxide surfaces in function of their environment (in terms of oxygen partial pressure and temperature). All these simulations have been performed with the ABINIT code. It is well known that DFT fails to describe correctly plutonium-based materials since 5f electrons in such systems are strongly correlated. In order to go beyond DFT, we have treated PuO{sub 2} and {beta}-Pu{sub 2}O{sub 3} in a DFT+U framework. We show that the couple of parameters (U,J) that works well for pure Pu is also well designed for describing ground state (GS) properties of these two oxides. The major improvement with respect with DFT is that we are able to predict an insulating GS in agreement with experiments. The presence of a gap in the DOS (Density of States) of plutonium oxides should play a significant role in the predicted surface reactivity. However, performing DFT+U calculations on surfaces of plutonium oxide from scratch was too ambitious. That is why we decided, as a first step, to study the stability of the (100), (110) and (111) surfaces of PuO{sub 2} in a DFT-GGA framework. For each of these orientations, we considered various terminations. These ab initio results have been introduced in a thermodynamic model which allows us to predict the relative stability of the different terminations as a function of temperature and oxygen partial pressure (p{sub O{sub 2}}). We conclude that at room temperature and for p{sub O{sub 2}}{approx}10 atm., the polar O{sub 2}-(100) termination is favoured. The stabilization of such a polar stoichiometric surface is surprising and should be confirmed by DFT+U calculations before any final conclusion. (authors)

  8. Tomografia computadorizada aplicada a estudos de um Planossolo

    Directory of Open Access Journals (Sweden)

    Pedrotti Alceu

    2003-01-01

    Full Text Available Na busca de técnicas mais apuradas para a determinação e avaliação de parâmetros físicos do solo com aplicabilidade em várzeas, vem se destacando a tomografia computadorizada, por medir a densidade e a umidade com boa sensibilidade e alta resolução espacial. O presente trabalho teve como objetivo descrever aspectos e procedimentos da calibração de um minitomógrafo de raios-X e gama para estudo da densidade e umidade de um Planossolo no Rio Grande do Sul, bem como estabelecer parâmetros estatísticos para sua adequada utilização. A calibração do minitomógrafo foi obtida pela regressão linear entre as unidades tomográficas (UT, apresentadas pelo programa de reconstrução de imagem, e os coeficientes de atenuação linear (µl, cm-1, medidos por transmissão direta de raios gama, em amostras dos horizontes A e B do Planossolo, água destilada, benzina e alumínio. Para as medidas de transmissão direta de radiação utilizaram-se recipientes com água destilada, benzina, solo e Al, obtendo-se as seguintes fórmulas para o cálculo da densidade do solo no horizonte A: Ds = [(UT/986,16-(0,200xteta]/0,267; e no horizonte B: Ds = [(UT/986,16-(0,200xteta]/0,297, em que UT é o valor médio de UT em cada linha e teta é a umidade volumétrica da amostra de solo, em m³ m-3. Com as configurações obtidas, verificou-se variabilidade média de 2,74% e 0,73%, respectivamente, em termos de homogeneidade e repetibilidade. Os erros atribuídos ao equipamento são de 0,051 e 0,046 Mg m-3, respectivamente, nos horizontes A e B, revelando precisão e adaptabilidade no emprego da técnica em estudos do Planossolo.

  9. Imagem organizacional: um estudo de caso sobre a PUC Minas.

    Directory of Open Access Journals (Sweden)

    Alexandre de Pádua Carrieri

    2008-06-01

    enquanto objeto de estudo, utilizou-se como estratégia metodológica a pesquisa qualitativa, com a análise de conteúdo. O trabalho foi realizado em duas etapas: entrevistas com os gestores da Universidade e pesquisa de campo com segmentos de públicos de interesse tais como: professores e alunos de escolas de segundo grau, alunos de graduação e profissionais de recursos humanos. Observou-se que novas formas de relacionamento entre a organização e seus públicos de interesse foram criadas. Foram também implantados novos meios de comunicação – mais modernos, ágeis e editorialmente trabalhados – e estruturados novos processos de comunicação e interlocução, oportunizando melhor controle para a alta administração, da imagem da sua Universidade. Palavras-chave: Estudos organizacionais; imagem organizacional; universidade Abstract This research has purpose know a little more about corporative image, considering its importance to management of organizations in current context of higher competition and greater demand. This study came from the configuration of the culture and identity of organization, foreseeing those items as fundamentals to definition of any institution’s image. Taking the Pontifícia Universidade Católica de Minas Gerais - PUC Minas – as object of study, the content analysis was carried out through a qualitative research - the employed methodological strategy. The work was conducted in two stages: (I interviews with managers, and (II field research with public segments, such as professors and high school students, undergraduate students, and HR professionals. By way of installing innovative, modern, agile and skillfully edited communication channels, new means of relationship were created among the organization and its stakeholders. Those original processes of communication and dialogue further enhanced the control of the university’s public image by its higher administration. Keywords: Organizational studies, organizational

  10. Importance of radioimmunoassays (HBsAg, HBsAb and HBcAb) for reducing the risk of hepatitis B transfer by blood

    International Nuclear Information System (INIS)

    Novak, J.; Kselikova, M.

    1979-01-01

    The principles are reported of the radioimmunoanalytical assay of the hepatitis B surface antigen, antibodies against this antigen which constitute immunologically indirect evidence, and antibodies against the nucleus of Dane's particles, which is circumstantial immunological evidence. The results obtained by radioimmunoassay are compared with those obtained by enzyme immunoassay. The results are presented obtained during the investigations of a total of 79 individuals, blood donors, health workers, and haemodialytic patients. In the whole group the hepatitis B surface antigen was proved by radioimmunoassay in 54%, by enzyme immunoassay in 47%; the antibody against the hepatitis B surface antigen in 19%; the antibody against the nucleus of the hepatitis B virus showed the largest proportion 75%. In 6.3% radioimmunoassay showed symptoms all three of hepatitis B, i.e., the surface antigen, the antibody against it, and the antibody against the hepatitis B virus nucleus; the correlation of the three symptoms is shown. The presence of HBsAg, HBsAb, and HBcAb is believed to be a contraindication of blood taking for routine purposes; the disappearance of HBsAg for a longer time may justify the re-inclusion among blood donors; the presence of HBsAb and HBcAb does not preclude the preparation of the plasma from such blood for the production of a specific anti-HBs immunoglobulin. (author)

  11. Ab initio calculation of molecular energies including parity violating interactions

    International Nuclear Information System (INIS)

    Bakasov, A.; Ha Taekyu; Quack, M.

    1995-01-01

    A new approach, RHF-CIS, based on the perturbation of the ground state RHF wave function by the CIS excitations, has been implemented for evaluation of energy of parity violating interaction in molecules, E pv . The earlier approach, RHF-SDE, was based on the perturbation of the RHF ground states by the single-determinant ''excitations'' (SDE). The results obtained show the dramatic difference between E pv values in the RHF-CIS framework and those in the RHF-SDE framework: the E pv values of the RHF-CIS formalism are more than one order of magnitude greater compared to the RHF-SDE formalism as well as the corresponding tensor components. The maximal total value obtained for hydrogen peroxide in the RHF-CIS framework is 3.661 X 10 -19 E H (DZ ** basis set) while the maximal E pv value for the RHF-SDE formalism is just 3.635 X 10 -20 E H (TZ basis set). It is remarkable that both in the RFH-CIS and in the RHF-SDE approaches the diagonal tensor components of E pv strictly follow the geometry of a molecule and are always different from zero at chiral conformations. The zeros of the total E pv at chiral geometries are now found to be the results of the interplay between the diagonal tensor components values. We have carried out exhaustive analysis of the RHF-SDE formalism and found that it is not sufficiently accurate for studies of E pv . To this end, we have completely reproduced the previous work, which has been done in the RHF-SDE frame-work, and developed it further, studying how the RHF-SDE results vary when changing size and quality of basis sets. This last resource does not save the RHF-SDE formalism for evaluations of E pv from the general failure. Packages of FORTRAN routines called ENWEAK/RHFSDE-93 and ENWEAK/RHFCIS-94 have been developed which run on top of an ab initio MO package. We used 6-31G and 6-31G**, DZ and DZ**, TZ and TZ**, and (10s, 6p,**) basis sets. We will discuss the importance of the present results for possible measurement of the parity

  12. Tritium Management In HCLL-PPCS Model AB Blanket

    International Nuclear Information System (INIS)

    Ricapito, I.; Aiello, A.; Benamati, G.; Utili, M.; Ciampichetti, A.; Zucchetti, M.

    2006-01-01

    One the main issues in the HCLL blanket development for a prototype fusion reactor is the technical feasibility of the bred tritium processing system. The basis of such concern lies in the very low tritium-Pb17Li Sieverts' constant, as measured by different scientists in the past years. In the PPCS reactor 650 g/d of tritium must be generated in the breeding blanket while less than 1 g/y of tritium has to be released to the environment through the secondary cooling circuit. As a consequence, CPS (Coolant Purification System) plays a fundamental role because it has to keep at an acceptable level the tritium partial pressure in the primary HCS (Helium Cooling Circuit) limiting, therefore, the tritium environmental release through leakage and permeation into the secondary cooling circuit. On the other hand, the He mass flow-rate to be processed by CPS is linear with the tritium permeation rate from the breeder into HCS. Therefore, with the above mentioned low Sieverts' constant values and the consequent high tritium partial pressure in the liquid metal, the possibility to keep acceptable the CPS capacity depends on a highly efficient and stable performance of tritium permeation barriers, to be applied not only on the blanket cooling plates but also on the steam generator walls. However, the experimental results on the tritium permeation barriers under relevant operative conditions were so far quite disappointing. The new data on the Sieverts' constant achieved at ENEA CR Brasimone, one order of magnitude higher than those founding the past, have a big impact in relaxing the above mentioned requirements for the tritium management in PPCS model AB reactor. Besides presenting and discussing these recent experimental results, an updated assessment of the tritium permeation rate from the liquid breeder into HCS through the cooling plates and from HCS into the environment through the steam generators is given in this paper. The consequent new constraints in terms of tritium

  13. Desafios dos Estudos Gays, Lésbicos e Transgêneros

    Directory of Open Access Journals (Sweden)

    Denilson Lopes

    2008-09-01

    Full Text Available Resumo: Este ensaio introduz algumas questões relativas aos estudos feministas, gays, lésbicos, transgênecos e teoria queer na busca de contribuições teórico-metodológicas na análise da cultura contemporânea. Palavras-chave: Estudos gays e lésbicos, estudos transgêneros, teoria queer, cultura. Abstrat: This essay introduces some issues related tofeminist studies, gay and lesbian studies, transgender studies and queer theory in the search of theoretical and methodological contributions in the analysis of contemporary culture. Key-words: Gay and Lesbian Studies, transgender studies, queer theory, culture

  14. Auditoria interna de sistema de gestão ambiental: estudo de caso no Verdegreen Hotel

    OpenAIRE

    Adriano Lucena da Silva; Isaiane Vieira de Melo; Diego Rodrigues de Lucena

    2017-01-01

    Esta pesquisa analisa as contribuições e os desafios associados às auditorias internas no Verdegreen Hotel, empreendimento hoteleiro de grande destaque na cidade de João Pessoa-PB, selecionado como unidade de estudo por dispor de um Sistema de Gestão Ambiental (SGA) ISO 14001 implantado e certificado. Este estudo trata de uma pesquisa descritiva, baseada em um estudo de caso qualitativo. As técnicas utilizadas na metodologia foram: levantamento bibliográfico sobre as normas ISO que abordam as...

  15. Aprendizagem Organizacional, Teoria Ator-Rede e Estudos Foucaultianos: Tempo, Espaço e Poder

    OpenAIRE

    Bruno Luiz Américo

    2016-01-01

    Esse trabalho baseia-se no mapeamento de lacunas encontradas nos desenvolvimentos dos estudos organizacionais de conhecimento e aprendizagem, e busca contribuir para a consolidação da aprendizagem organizacional como uma teoria do movimento organizacional/social. Para isso, propõe diálogo entre a Perspectiva Social-Política da Aprendizagem social, a Teoria Ator-Rede e os estudos foucaultianos. O trabalho conclui destacando o potencial da teoria ator-rede e dos estudos foucaultianos para anali...

  16. Field Trial Performance of Herculex XTRA (Cry34Ab1/Cry35Ab1) and SmartStax (Cry34Ab1/Cry35Ab1 + Cry3Bb1) Hybrids and Soil Insecticides Against Western and Northern Corn Rootworms (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Johnson, K D; Campbell, L A; Lepping, M D; Rule, D M

    2017-06-01

    Western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), and northern corn rootworm, Diabrotica barberi Smith and Lawrence (Coleoptera: Chrysomelidae), are important insect pests in corn, Zea mays L. For more than a decade, growers have been using transgenic plants expressing proteins from the bacterium Bacillus thuringiensis (Bt) to protect corn roots from feeding. In 2011, western corn rootworm populations were reported to have developed resistance to Bt hybrids expressing Cry3Bb1 and later found to be cross-resistant to hybrids expressing mCry3A and eCry3.1Ab. The identification of resistance to Cry3 (Cry3Bb1, mCry3A, and eCry3.1Ab) hybrids led to concerns about durability and efficacy of products with single traits and of products containing a pyramid of a Cry3 protein and the binary Bt proteins Cry34Ab1 and Cry35Ab1. From 2012 to 2014, 43 field trials were conducted across the central United States to estimate root protection provided by plants expressing Cry34Ab1/Cry35Ab1 alone (Herculex RW) or pyramided with Cry3Bb1 (SmartStax). These technologies were evaluated with and without soil-applied insecticides to determine if additional management measures provided benefit where Cry3 performance was reduced. Trials were categorized for analysis based on rootworm damage levels on Cry3-expressing hybrids and rootworm feeding pressure within each trial. Across scenarios, Cry34Ab1/Cry35Ab1 hybrids provided excellent root protection. Pyramided traits provided greater root and yield protection than non-Bt plus a soil-applied insecticide, and only in trials where larval feeding pressure exceeded two nodes of damage did Cry34Ab1/Cry35Ab1 single-trait hybrids and pyramided hybrids show greater root protection from the addition of soil-applied insecticides. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Effectiveness of motorcycle antilock braking systems (ABS) in reducing crashes, the first cross-national study.

    Science.gov (United States)

    Rizzi, Matteo; Strandroth, Johan; Kullgren, Anders; Tingvall, Claes; Fildes, Brian

    2015-01-01

    This study set out to evaluate the effectiveness of motorcycle antilock braking systems (ABS) in reducing real-life crashes. Since the European Parliament has voted on legislation making ABS mandatory on all new motorcycles over 125 cc from 2016, the fitment rate in Europe is likely to increase in the coming years. Though previous research has focused on mostly large displacement motorcycles, this study used police reports from Spain (2006-2009), Italy (2009), and Sweden (2003-2012) in order to analyze a wide range of motorcycles, including scooters, and compare countries with different motorcycling habits. The statistical analysis used odds ratio calculations with an induced exposure approach. Previous research found that head-on crashes were the least ABS-affected crash type and was therefore used as the nonsensitive crash type for ABS in these calculations. The same motorcycle models, with and without ABS, were compared and the calculations were carried out for each country separately. Crashes involving only scooters were further analyzed. The effectiveness of motorcycle ABS in reducing injury crashes ranged from 24% (95% confidence interval [CI], 12-36) in Italy to 29% (95% CI, 20-38) in Spain, and 34% (95% CI, 16-52) in Sweden. The reductions in severe and fatal crashes were even greater, at 34% (95% CI, 24-44) in Spain and 42% (95% CI, 23-61) in Sweden. The overall reductions of crashes involving ABS-equipped scooters (at least 250 cc) were 27% (95% CI, 12-42) in Italy and 22% (95% CI, 2-42) in Spain. ABS on scooters with at least a 250 cc engine reduced severe and fatal crashes by 31% (95% CI, 12-50), based on Spanish data alone. At this stage, there is more than sufficient scientific-based evidence to support the implementation of ABS on all motorcycles, even light ones. Further research should aim at understanding the injury mitigating effects of motorcycle ABS, possibly in combination with combined braking systems.

  18. Estudo da auditoria de contas em um hospital de ensino

    Directory of Open Access Journals (Sweden)

    Gabriela Favaro Faria Guerrer

    2015-06-01

    Full Text Available RESUMOObjetivos:verificar os itens componentes das contas hospitalares, conferidos por enfermeiros auditores, que mais recebem ajustes no momento da pré-análise; identificar o impacto dos ajustes no faturamento das contas analisadas por enfermeiros e médicos auditores e identificar as glosas relacionadas aos itens conferidos pela equipe de auditoria.Método:pesquisa quantitativa exploratória, descritiva, do tipo estudo de caso único.Resultados:após a análise de 2.613 contas constatou-se que o item mais incluído por enfermeiros foram gases (90,5% e o mais excluído medicamentos de internação (41,2%. Materiais de hemodinâmica; gases e equipamentos foram os que mais impactaram nos ajustes positivos. Os ajustes negativos decorreram de lançamentos indevidos nas contas e não geraram prejuízos de faturamento. Do total de glosas 52,24% referiu-se à pré-análise dos enfermeiros e 47,76% a dos médicos.Conclusão:a presente investigação do processo de pré-análise fornece subsídios que contribuem para o avanço no conhecimento sobre a auditoria de contas hospitalares.

  19. Desordens alimentares e perfeccionismo: um estudo com atletas portugueses

    Directory of Open Access Journals (Sweden)

    Rui Gomes

    2010-12-01

    Full Text Available Este trabalho analisa a relação entre desordens alimentares e tendência para o perfeccionismo no desporto. Participaram no estudo 299 atletas a competirem nas principais divisões de diferentes modalidades. Foi aplicado um protocolo de avaliação com o Questionário de Avaliação das Desordens Alimentares (Fairburn & Beglin, 1994 e a Escala Multidimensional de Perfeccionismo no Desporto (Dunn et alii, 2006. Aplicaram-se procedimentos de análise de variância multivariada (Manovas e análises de regressão hierárquica no tratamento dos dados. Dois resultados devem ser salientados: i atletas mais novos e atletas com maior tendência para as desordens alimentares evidenciaram maior perfeccionismo; ii a dimensão de preocupação com os erros foi a principal variável preditora das desordens alimentares. Concluindo, observou-se uma relação entre a tendência para as desordens alimentares e a orientação para a exigência pessoal e preocupação com os erros por parte dos atletas

  20. Do Antissocialismo ao Anticapitalismo: um estudo sobre a Rerum Novarum

    Directory of Open Access Journals (Sweden)

    Claudinei Magno Magre Mendes

    2016-05-01

    Full Text Available O objetivo deste artigo é examinar o processo de constituição do anticapitalismo por meio da análise da Rerum Novarum, a primeira encíclica social. Comparando esta com as encíclicas anteriores do século XIX, pudemos estabelecer o que ela trouxe de novidade no que diz respeito ao combate que a Igreja travava contra o socialismo. Com essa comparação, foi possível caracterizar a postura anticapitalista, confrontando a nossa maneira de concebê-la com as demais. Para o exame da Rerum Novarum foi igualmente importante analisar alguns estudos referentes a ela, tanto os que apareceram logo após a sua publicação como os que foram realizados em décadas mais recentes. Como conclusão, definimos o anticapitalismo como uma atitude que somente poderia ter surgido em condições sociais e políticas bastante particulares e que apenas apareceram em fins do século XIX.

  1. ESTUDO DA MATURIDADE DE PROCESSOS COBIT NA ELETROBRÁS

    Directory of Open Access Journals (Sweden)

    Fernando Cesar Almeida Silva

    2017-09-01

    Full Text Available Este artigo tem como objetivo descrever como foi realizado um estudo da maturidade dos processos CobiT em uma empresa do setor de energia elétrica do Brasil. Foi feita uma pesquisa onde os integrantes do Comitê de Tecnologia de Informação desta empresa informam sua percepção do nível de maturidade dos diversos processos existentes no CobiT. É realizada uma análise dos resultados onde é considerado o contexto no qual a empresa se insere. Para finalizar é proposto um sistema baseado no PDCA com o objetivo de aprimorar os processos que receberam classificação de avaliação mais baixa. A priorização de quais processos devem ser aprimorados primeiro, é baseada em critérios que levam em consideração os principais controles de ambiente do PCAOB, uma vez que esta empresa é auditada regularmente devido às obrigatoriedades da lei Sarbanes-Oxley.

  2. Trabalho e riscos de adoecimento: um estudo entre policiais civis

    Directory of Open Access Journals (Sweden)

    Vânia Cristine Cavalcante Anchieta

    Full Text Available Este estudo teve como objetivo avaliar a percepção que os policiais civis do DF têm sobre o seu contexto de trabalho, suas exigências, assim como as vivências e os problemas físicos, psicológicos e sociais causados pelo trabalho, procurando fazer inferências sobre as estratégias de mediação utilizadas para evitar o sofrimento e os riscos de adoecimento. Foi aplicado o Inventário do Trabalho e Riscos de Adoecimento (ITRA em 160 policiais civis, homens e mulheres, recém empossados na Instituição (tempo médio de oito meses de ingresso na Instituição. Os resultados indicaram que, apesar de não ficarem evidentes danos graves à saúde do policial novato, há riscos de acontecerem falhas nas estratégias de mediação em relação a fatores que levam ao adoecimento.

  3. Transplante de bexiga: estudo piloto Bladder transplant: pilot study

    Directory of Open Access Journals (Sweden)

    Frederico Teixeira Brandt

    2004-08-01

    Full Text Available OBJETIVO: Desenvolver um modelo biológico que seja viável para o estudo sistemático do transplante de bexiga. MÉTODOS: Cães mestiços vivos são usados como doadores e receptores do segmento supra-trigonal da bexiga. RESULTADOS: Os pacientes tansplantados só fizeram uso de imunossupressão por 15 dias, estão vivos e sadios com 18 meses de transplante. Desde o primeiro mês de transplante os cães apresentam controle funcional da micção, inclusive sem urina residual importante. CONCLUSÃO: Transplante de bexiga em cães é um modelo viável, fisiológico e simples.PURPOSE: Our aim was to study the feasible of bladder transplants. METHODS: Alive mongrel dogs are being used as trigone bladder segment donators and receptors RESULTS: The transplanted patients had 15 days of immunosuppression and so far an 18-months satisfactory post-operative outcome. Since a month after surgery, the dogs have been presenting full functional control of micturition and the evaluations have been showing normal bladder storage and contraction capacities. CONCLUSION: bladder transplants in dogs its a possible, physiological and simple model.

  4. Raiva humana: estudo neuropatológico de trinta casos

    Directory of Open Access Journals (Sweden)

    R. V. C. Assis

    1984-12-01

    Full Text Available O estudo epidemiológico e neuropatológico concernente a trinta autópsias de encefalite rábica foi realizado, tendo sido os dados obtidos comparados com aqueles da literatura. Não houve relação estatística entre a topografia lesional e o local da mordida, entre o período de incubação ou a duração da doença e a presença ou ausência de inclusões virais (IV assim como entre a intensidade do processo inflamatorio (PI e a presença de IV. A dispersão do PI e das IV através o SNC foi diretamente proporcional à sua intensidade. A estrutura mais freqüentemente comprometida pelo PI foi o mesencéfalo, seguido pelo bulbo, ponte e medula espinhal. A estrutura mais intensamente afetada foi o bulbo. As IV foram particularmente proeminentes no hipocampo e cerebelo.

  5. Cuidados paliativos e luto: um estudo bibliométrico

    Directory of Open Access Journals (Sweden)

    Maria Andréa Fernandes

    Full Text Available RESUMO Analisar a produção científica, publicada em periódicos online, sobre os cuidados paliativos e luto. Trata-se de um estudo bibliométrico, realizado com 48 artigos, publicados entre 2005 e 2014, selecionados nas bases de dados LILACS, MEDLINE, IBECS, PubMed, SciELO e DOAJ. Os anos de 2012 e 2013 apresentaram um quantitativo maior de publicações. Foram identificados 37 veículos de divulgação, dos quais o periódico Medicina Paliativa Journal foi o que mais publicou sobre a temática, e o American Journal of Psychiatry apresentou o maior fator de impacto. A maioria das publicações foi produzida por pesquisadores da área de Medicina e predominaram autores com o título de doutor. Espera-se ter contribuído para estimular as produções científicas nessa temática e subsidiar na difusão desse conhecimento específico e auxiliar na preparação e formação dos profissionais para cuidado ao paciente sob cuidados paliativos no enfrentamento do luto.

  6. Síndrome de Sotos: Um Estudo de Caso

    Directory of Open Access Journals (Sweden)

    Juliana Alves Cunha

    2015-01-01

    Full Text Available Este estudo destina-se a apresentar um caso de Síndrome de Sotos. Buscou-se relatar a resposta desta criança ao tratamento cinesiológico funcional, considerando as principais características como deficiência mental, hipotonia, distúrbios ortopédicos, estatura elevada, macrocefalia, incoordenação motora e déficit de marcha. Após 11 meses de acompanhamento, observou-se, com o tratamento cinesiológico funcional, melhora do equilíbrio, das habilidades motoras (coordenação, da marcha e da postura. Espera-se com este trabalho, além de apresentar as características da síndrome de Sotos juntamente com seu diagnóstico diferencial, relatar a importância da intervenção fisioterapêutica e do trabalho multidisciplinar envolvendo a psicologia e a fonoaudiologia.

  7. DIFICULDADES DE APRENDIZAGEM E RETARDO MENTAL: ESTUDO DE CASO

    Directory of Open Access Journals (Sweden)

    Teresa Helena Schoen-Ferreira

    2010-06-01

    Full Text Available O diagnóstico precoce é sempre um forte aliado na terapêutica de qualquer patologia, inclusive em casos de retardo mental. Assim, pode-se planejar uma intervenção mais adequada e efetiva, viabilizando a inserção social do indivíduo. O objetivo deste estudo é observar o quadro de Dificuldades de Aprendizagem como manifestação de Retardo Mental em dois irmãos gêmeos de 5 anos e 7 meses, cursando o Estágio II (série que antecede o Ensino Fundamental em dois anos de uma escola de rede pública de ensino de São Paulo. Para a sua elaboração foram aplicados, nas crianças, testes do desenvolvimento em várias áreas e um teste de inteligência, e realizadas entrevistas dirigidas com sua mãe e suas professoras. Desta forma, dispusemos de informações acerca do desenvolvimento motor, psicológico e social dos gêmeos, as quais possibilitarão o acompanhamento dos quadros de maneira mais próxima do ideal.

  8. YaxAB, a Yersinia enterocolitica Pore-Forming Toxin Regulated by RovA

    Science.gov (United States)

    Wagner, Nikki J.; Lin, Carolina P.; Borst, Luke B.

    2013-01-01

    The transcriptional regulator RovA positively regulates transcription of the Yersinia enterocolitica virulence gene inv. Invasin, encoded by inv, is important for establishment of Y. enterocolitica infection. However, a rovA mutant is more attenuated for virulence than an inv mutant, implying that RovA regulates additional virulence genes. When the Y. enterocolitica RovA regulon was defined by microarray analysis, YE1984 and YE1985 were among the genes identified as being upregulated by RovA. Since these genes are homologous to Xenorhabdus nematophila cytotoxin genes xaxA and xaxB, we named them yaxA and yaxB, respectively. In this work, we demonstrate the effects of YaxAB on the course of infection in the murine model. While a yaxAB mutant (ΔyaxAB) is capable of colonizing mice at the same level as the wild type, it slightly delays the course of infection and results in differing pathology in the spleen. Further, we found that yaxAB encode a probable cytotoxin capable of lysing mammalian cells, that both YaxA and YaxB are required for cytotoxic activity, and that the two proteins associate. YaxAB-mediated cell death occurs via osmotic lysis through the formation of distinct membrane pores. In silico tertiary structural analysis identified predicted structural homology between YaxA and proteins in pore-forming toxin complexes from Bacillus cereus (HBL-B) and Escherichia coli (HlyE). Thus, it appears that YaxAB function as virulence factors by inducing cell lysis through the formation of pores in the host cell membrane. This characterization of YaxAB supports the hypothesis that RovA regulates expression of multiple virulence factors in Y. enterocolitica. PMID:24002058

  9. Synthesis of an A'B' Precursor to Angelmicin B: Product Diversification in the Suárez Lactol Fragmentation.

    Science.gov (United States)

    Li, Jialiang; Todaro, Louis; Mootoo, David R

    2011-11-01

    We describe a synthetic strategy for the angelimicin family of anthraquinoid natural products that involves converting a central highly oxygenated decalin intermediate to the AB and A'B' subunits. Herein, we report the synthesis of the bicyclic A'B' subunit that complements our earlier route to the tricyclic AB framework. The differentiating tact in the two syntheses focused on controlling the Suárez radical fragmentation of lactol precursors by modulating the substrate's structural rigidity. A more flexible lactol gave the tricyclic AB framework, whereas a more rigid substrate led to the bicyclic A'B' precursor, presumably through divergent pathways from the radical produced in the initial fragmentation step. These results establish a versatile advanced synthetic precursor for the angelimicins, and on a more general note, illustrate strategies for applying the Suárez fragmentation to diverse and complex molecular frameworks.

  10. Use of an anti-platelet monoclonal antibody F (ab')2 fragment for imaging thrombus

    International Nuclear Information System (INIS)

    Loutfi, I.; Stuttle, A.W.J.; Peters, A.M.; George, P.; Lavender, J.P.; Lumley, P.

    1990-01-01

    Ten patients with suspected thrombus have been studied using 111 In-labelled F (ab')2 fragments of P256, a monoclonal antibody which recognizes an epitope on the platelet membrane glycoprotein IIb/IIIa complex. The F (ab')2 fragment was radiolabelled with 111 In via diethylenetri-aminepentamacetic acid to give a specific activity of up to 190 MBq (5mCi) mg - 1 without impairment of immunoreactivity. In vitro platelet aggregation studies showed that the F (ab')2 fragment caused less platelet aggregation than the whole antibody on a molar ratio and was without significant effect upon the sensitivity of platelets to a range of aggregating agents. Platalets were labelled in ten patients by intravenous injection of approximately 100 μg P256 F (ab')2. Of the ten patients studies, six showed localization of activity consistent with platelet accumulation. Localization was clearly seen when associated with thrombus of the lower limbs (three patients: deep vein thrombosis; one patient: aortofemoral graft), and was apparent although less marked in two other cases, one of aortic aneurysm and one of carotid stenosis. Use of radiolabelled P256 F (ab')2 offers a means of non-invasive detection of thrombus which, from in vitro studies, would appear to have less direct effect of platelet behaviour than the whole antibody. (author). 9 refs. 8 figs. 1 tab

  11. The preparation of F(ab')2 fragment and it's application in tumor radioimmunoimaging

    International Nuclear Information System (INIS)

    Yang Ziyi

    1991-01-01

    Monoclonal antibody against lung cancer was digested into F(ab') 2 fragment by pepsin and papain digestion. The yields of pure F(ab') 2 were 32.3 ± 5.5% and 52.3 ± 12.0% respectively. The immunoreactivity of F(ab') 2 was based on the ELISA assay and the cell binding studies was retained well. In the localization experiments, radioiodinated F(ab') 2 was injected intraperitoneally into the nude mice bearing human xenografts of lung cancer. The highest radioactivity in tumors, 1.37% of injected dose per gram, was reached on the first day after injection; its T/NT ratios were higher than those of the intact IgG in all tissues except kidney. The localization index (LI) in tumors was 4.95, while the average LI value of normal tissues was 1.25. After the injection of 131 I-F(ab') 2 intraperitoneally into lung tumor-bearing nude mice, photo scintigraphy was performed at intervals of 12 hrs. The xenografts were visualized distinctly during 36 ∼ 48 hr, and the nonspecific background was very low at 48 hr

  12. Remodeling of the AB site of rat parvalbumin and oncomodulin into a canonical EF-hand

    DEFF Research Database (Denmark)

    Cox, J A; Durussel, I; Scott, D J

    1999-01-01

    -residue canonical loop. To create an optical conformational probe we also expressed the homologs with a F102W replacement. Unexpectedly, in none of the proteins did the mutation reactivate the AB site. The AB-remodeled parvalbumins bind two Ca2+ ions with strong positive cooperativity (nH = 2......Parvalbumin (PV) and the homologous protein oncomodulin (OM) contain three EF-hand motifs, but the first site (AB) cannot bind Ca2+. Here we aimed to recreate the putative ancestral proteins [D19-28E]PV and [D19-28E]OM by replacing the 10-residue-long nonfunctional loop in the AB site by a 12...... conformations. The AB-remodeled oncomodulins also bind two Ca2+ with [Ca2+]0.5 = 43 microM and nH = 1.45. Mg2+ does not affect Ca2+ binding. Again the Ca2+ forms display two-thirds of the alpha-helical content in the wild-type, while their core is still strongly hydrophobic as monitored by Trp and Tyr...

  13. Gas atomization of Cu-modified AB5 metal hydride alloys

    International Nuclear Information System (INIS)

    Young, K.; Ouchi, T.; Banik, A.; Koch, J.; Fetcenko, M.A.; Bendersky, L.A.; Wang, K.; Vaudin, M.

    2011-01-01

    Research highlights: → The gas atomization process together with a hydrogen annealing process was demonstrated on AB5 alloys. → The method was found to be effective in restoring the original cycle life sacrificed by the incorporation of copper in the alloy formula as a means of improving the low temperature performance of AB 5 alloys. → The new process also improves high rate, low temperature, and charge retention performances for both Cu-free and Cu-containing AB 5 alloys. - Abstract: Gas atomization together with a hydrogen annealing process has been proposed as a method to achieve improved low-temperature performance of AB 5 alloy electrodes in Ni/MH batteries and restore the original cycle life which was sacrificed by the incorporation of copper in the alloy formula. While the gas atomization process reduces the lattice constant aspect ratio c/a of the Cu-containing alloys, the addition of a hydrogen annealing step recovers this property, although it is still inferior to the conventionally prepared annealed Cu-free alloy. This observation correlates very well with the cycle life performance. In addition to extending the cycle life of the Cu-containing metal hydride electrode, processing by gas atomization with additional hydrogen annealing improves high-rate, low-temperature, and charge retention performances for both Cu-free and Cu-containing AB 5 alloys. The degradation mechanisms of alloys made by different processes through cycling are also discussed.

  14. Physical and Mechanical Characteristics of Kevlar Fiber-Reinforced PC/ABS Composites

    Directory of Open Access Journals (Sweden)

    Kuljira Sujirote

    2012-01-01

    Full Text Available In this research, the composites between polycarbonate (PC and acrylonitrile-butadiene-styrene (ABS alloy and Kevlar fiber were prepared. The flexural and tensile properties of PC/ABS alloy and its composites were determined using a universal testing machine. The synergistic behavior of flexural modulus was observed for all regions of PC contents, while the synergism of flexural strength and tensile strength were found in some PC contents. It was found that the optimum weight ratio of PC:ABS was 60:40. In the Kevlar Fiber-reinforced PC/ABS composite system at PC:ABS of 60:40, both flexural modulus and strength were increased with matrix contents. Additionally, the flexural strength drastically increased with the matrix content and then reached the maximum value of 167 MPa at the matrix content of 33.4 wt%. The results from peel test, water contact measurement, and scanning electron microscopy (SEM reveal that the interfacial adhesion between the Kevlar fiber and the polymer matrix could be improved by increasing the PC content in the matrix.

  15. Differential screening of phage-ab libraries by oligonucleotide microarray technology.

    Directory of Open Access Journals (Sweden)

    Paolo Monaci

    Full Text Available A novel and efficient tagArray technology was developed that allows rapid identification of antibodies which bind to receptors with a specific expression profile, in the absence of biological information. This method is based on the cloning of a specific, short nucleotide sequence (tag in the phagemid coding for each phage-displayed antibody fragment (phage-Ab present in a library. In order to set up and validate the method we identified about 10,000 different phage-Abs binding to receptors expressed in their native form on the cell surface (10 k Membranome collection and tagged each individual phage-Ab. The frequency of each phage-Ab in a given population can at this point be inferred by measuring the frequency of its associated tag sequence through standard DNA hybridization methods. Using tiny amounts of biological samples we identified phage-Abs binding to receptors preferentially expressed on primary tumor cells rather than on cells obtained from matched normal tissues. These antibodies inhibited cell proliferation in vitro and tumor development in vivo, thus representing therapeutic lead candidates.

  16. The NISTmAb Reference Material 8671 lifecycle management and quality plan.

    Science.gov (United States)

    Schiel, John E; Turner, Abigail

    2018-03-01

    Comprehensive analysis of monoclonal antibody therapeutics involves an ever expanding cadre of technologies. Lifecycle-appropriate application of current and emerging techniques requires rigorous testing followed by discussion between industry and regulators in a pre-competitive space, an effort that may be facilitated by a widely available test metric. Biopharmaceutical quality materials, however, are often difficult to access and/or are protected by intellectual property rights. The NISTmAb, humanized IgG1κ Reference Material 8671 (RM 8671), has been established with the intent of filling that void. The NISTmAb embodies the quality and characteristics of a typical biopharmaceutical product, is widely available to the biopharmaceutical community, and is an open innovation tool for development and dissemination of results. The NISTmAb lifecyle management plan described herein provides a hierarchical strategy for maintenance of quality over time through rigorous method qualification detailed in additional submissions in the current publication series. The NISTmAb RM 8671 is a representative monoclonal antibody material and provides a means to continually evaluate current best practices, promote innovative approaches, and inform regulatory paradigms as technology advances. Graphical abstract The NISTmAb Reference Material (RM) 8671 is intended to be an industry standard monoclonal antibody for pre-competitive harmonization of best practices and designing next generation characterization technologies for identity, quality, and stability testing.

  17. A Force Balanced Fragmentation Method for ab Initio Molecular Dynamic Simulation of Protein

    Directory of Open Access Journals (Sweden)

    Mingyuan Xu

    2018-05-01

    Full Text Available A force balanced generalized molecular fractionation with conjugate caps (FB-GMFCC method is proposed for ab initio molecular dynamic simulation of proteins. In this approach, the energy of the protein is computed by a linear combination of the QM energies of individual residues and molecular fragments that account for the two-body interaction of hydrogen bond between backbone peptides. The atomic forces on the caped H atoms were corrected to conserve the total force of the protein. Using this approach, ab initio molecular dynamic simulation of an Ace-(ALA9-NME linear peptide showed the conservation of the total energy of the system throughout the simulation. Further a more robust 110 ps ab initio molecular dynamic simulation was performed for a protein with 56 residues and 862 atoms in explicit water. Compared with the classical force field, the ab initio molecular dynamic simulations gave better description of the geometry of peptide bonds. Although further development is still needed, the current approach is highly efficient, trivially parallel, and can be applied to ab initio molecular dynamic simulation study of large proteins.

  18. Helicase properties of the Escherichia coli UvrAb protein complex

    International Nuclear Information System (INIS)

    Oh, E.Y.; Grossman, L.

    1987-01-01

    The Escherichia coli UvrA protein has an associated ATPase activity with a turnover number affected by the presence of UvrB protein as well as by DNA. Specifically, the structure of DNA significantly influences the turnover rate of the UvrAB ATPase activity. Double-stranded DNA maximally activates the turnover rate 10-fold whereas single-stranded DNA maximally activates the turnover rate 20-fold, suggesting that the mode of interaction of UvrAB protein with different DNAs is distinctive. We have previously shown that the UvrAB protein complex, driven by the binding energy of ATP, can locally unwind supercoiled DNA. The nature of the DNA unwinding activity and single-stranded DNA activation of ATPase activity suggest potential helicase activity. In the presence of a number of helicase substrates, the UvrAB complex, indeed, manifests a strand-displacement activity-unwinding short duplexes and D-loop DNA, thereby generating component DNA structures. The energy for the activity is derived from ATP or dATP hydrolysis. Unlike the E. coli DnaB, the UvrAB helicase is sensitive to UV-induced photoproducts

  19. Bioinformatic analysis of phage AB3, a phiKMV-like virus infecting Acinetobacter baumannii.

    Science.gov (United States)

    Zhang, J; Liu, X; Li, X-J

    2015-01-16

    The phages of Acinetobacter baumannii has drawn increasing attention because of the multi-drug resistance of A. baumanni. The aim of this study was to sequence Acinetobacter baumannii phage AB3 and conduct bioinformatic analysis to lay a foundation for genome remodeling and phage therapy. We isolated and sequenced A. baumannii phage AB3 and attempted to annotate and analyze its genome. The results showed that the genome is a double-stranded DNA with a total length of 31,185 base pairs (bp) and 97 open reading frames greater than 100 bp. The genome includes 28 predicted genes, of which 24 are homologous to phage AB1. The entire coding sequence is located on the negative strand, representing 90.8% of the total length. The G+C mol% was 39.18%, without areas of high G+C content over 200 bp in length. No GC island, tRNA gene, or repeated sequence was identified. Gene lengths were 120-3099 bp, with an average of 1011 bp. Six genes were found to be greater than 2000 bp in length. Genomic alignment and phylogenetic analysis of the RNA polymerase gene showed that similar to phage AB1, phage AB3 is a phiKMV-like virus in the T7 phage family.

  20. Field evidence for the exposure of ground beetles to Cry1Ab from transgenic corn.

    Science.gov (United States)

    Zwahlen, Claudia; Andow, David A

    2005-01-01

    Non-target organisms associated with the soil might be adversely affected by exposure to the CrylAb protein from Bacillus thuringiensis (Bt) in transgenic corn (Zea mays L.). To check for such exposure, we used ELISA to test for Cry1Ab in ground beetles collected live from fields with Bt corn residues and Bt corn (Bt/Bt), Bt corn residues and non-Bt crops (Bt/non-Bt), or non-Bt corn residues and non-Bt crops (non-Bt/non-Bt). In fields with Bt corn residues (Bt/Bt and Bt/non-Bt), Cry1Ab was present in all seven species of ground beetles examined (Agonum placidum, Bembidion rupicola, Clivina impressefrons, Cyclotrachelus iowensis, Harpalus pensylvanicus, Poecilus chalcites, and Poecilus lucublandus). For the two most abundant species, P. chalcites and P. lucublandus, the proportion of beetles with Cry1Ab was significantly higher in Bt/Bt fields (0.50-1.0) and Bt/non-Bt fields (0.41-0.50) than in non-Bt/non-Bt fields (0.0). This is the first field evidence that some ground beetle species are exposed to Cry1Ab. The implications of exposure on the performance of these non-target organisms are unclear.

  1. Artesanato na terceira idade: um estudo na cidade de Sinop

    Directory of Open Access Journals (Sweden)

    Rosane Marlene Weber

    2012-06-01

    Full Text Available O presente artigo sobre o artesanato e a Terceira Idade, pesquisa realizada em 2011, teve como metodologia o Estudo de Caso do tipo etnográfico. A metodologia de investigação ocorreu por meio de entrevistas semiestruturadas, orais e transcritas, observação e fotografias dos artesanatos em locais de venda e nas residências dos artesãos. Os sujeitos da pesquisa foram: a presidente da Associação da Casa do Artesão de Sinop-MT e oito artesãos. O objetivo foi mostrar a importância do artesanato como atividade educacional e como produtora de autonomia e autoria para os artesãos da Terceira Idade, motivados em realizar este trabalho nesta fase da vida. Para o embasamento teórico utilizou-se obras de Paulo Freire, Moacir Gadotti e sobre a Terceira Idade a coleção de Vivaidade com a organizadora Anita Liberalesso Neri. A análise das entrevistas mostrou que o artesanato traz autonomia educacional quando o idoso busca sozinho aprender sobre o objeto a ser realizado, assim como autonomia financeira, uma vez que a venda do artesanato proporciona certa independência econômica. Em relação ao sentimento de autoria das peças criadas constatou-se muita satisfação e realização, o que motiva a continuar sendo úteis e produtivos na Terceira Idade com muita criatividade. Palavras-chave: educação; terceira idade; artesanato; autonomia; autoria.

  2. Atitude religiosa e sentido da vida: um estudo correlacional

    Directory of Open Access Journals (Sweden)

    Thiago Antônio Avellar de Aquino

    Full Text Available A presente pesquisa abordou o sentido da vida (Viktor Frankl e a atitude religiosa. Para a logoterapia, a religiosidade não significa necessariamente a opção por uma crença religiosa, mas pode ser uma das possíveis maneiras de o homem encontrar sentido para a vida. O objetivo deste estudo foi investigar a relação entre o sentido de vida e a atitude religiosa de forma transversal e correlacional. A amostra foi composta por 300 sujeitos de ambos os sexos, 37% homens e 63% mulheres, com idade média de 42 anos. Os instrumentos utilizados foram o Teste Propósito de Vida (PIL-Test, de James C. Crumbauch e Leonard T. Maholick, e a Escala de Atitude Religiosa/Espiritualidade, de Aquino. Os resultados apontam correlações positivas entre a atitude religiosa e a realização existencial, a atitude religiosa e a idade, o desespero existencial e o vazio existencial e a realização existencial e a idade, havendo também correlações negativas entre a atitude religiosa e o desespero existencial, a atitude religiosa e o vazio existencial, o desespero existencial e a realização existencial e o vazio existencial e a realização existencial. Concluiu-se que a atitude religiosa é uma forma de encontro de sentido de vida bem como um elemento de prevenção do vazio existencial e do desespero existencial.

  3. Toxoplasmose em primatas neotropicais: estudo retrospectivo de sete casos

    Directory of Open Access Journals (Sweden)

    Renata A. Casagrande

    2013-01-01

    Full Text Available A toxoplasmose é considerada uma doença parasitária fatal em primatas neotropicais. O objetivo deste trabalho foi descrever, através de um estudo retrospectivo, os casos de toxoplasmose em primatas neotropicais. No período de 1999-2009 foram realizados 86 exames anatomopatológicos em primatas e a toxoplasmose foi a enfermidade mais comum (7/86, relatando-se um caso em sagui-do-tufo-preto (Callithrix penicillata e seis em bugio-ruivo (Alouatta guariba. Dois animais foram encontrados mortos e cinco morreram em poucos dias. Os sinais clínicos mais frequentes foram apatia e anorexia (5/7, distensão abdominal (4/7 e febre (3/7. Na necropsia observou-se esplenomegalia (4/7, hemorragia do trato digestório, linfonodos e bexiga (4/7, pulmões avermelhados (3/7 e hepatomegalia (2/7. No exame histopatológico evidenciou-se hepatite (7/7, esplenite (3/7, miocardite (2/7, enterite (2/7, linfadenite (1/7 e sialite (1/7 necróticas e, pneumonia intersticial (4/7. Em fígado, pulmões, baço, coração, linfonodos e glândula salivar havia taquizoítos de Toxoplasma gondii que foram também detectados pelo exame de imuno-histoquímica anti-T. gondii em fígado, baço e pulmões (5/7. A toxoplasmose pode causar alta mortalidade em colônias de primatas neotropicais e representar mais uma ameaça à conversação dessas espécies em cativeiro. Sendo assim, medidas preventivas devem ser tomadas para evitar a contaminação desses animais.

  4. Estudos de cestóides de peixes do Brasil

    Directory of Open Access Journals (Sweden)

    A. Arandas Rego

    1974-01-01

    Full Text Available Os autores iniciam com este trabalho um estudo sistemático de determinação dos cestóides de peixes depositados na Coleção helmintológica do Instituto Oswaldo Cruz. São referidas ou descritas as seguintes espécies e seus hospedeiros: Schizochoerus liguloideus (Diesing, 1850 e Nesolecithus janicki Posche, 1922, ambas de Arapaima gigas (Cuvier, (piracuru; Gyrocotyle meandrica Herrera, 1946, de Callorhynchus callorhynchus (L., (quimera; Acanthobothrium dasybati Yamaguti, 1934 e Pterobothriidae não identificado, de uma arraia não determinada; três tipos larvares de trypanorrhyncha e um de Proteocephalidea, de Cynoscion striatus (Cuv. e C. leiarchus (pescadinha; Proteocephalus jandia Woodland, 1934, de um bagre não determinado. Monticellia siluri (Fuhrmann, 1916 e Amphoteromorphus praeputialis sp. n. de Cetopsis caecutiens e Nomimoscolex magna sp. n. de Pimelodus clarias (mandi.The authors start, with this note, a systematic study for determination of cestodes of fishes of the Helminthological Collection of the Instituto Oswaldo Cruz. The following species and hosts are refered and described: Schizochoerus liguloideus (Diesing, 1850 and Nesolecithus janicki poche, 1922 both of Arapaima gigas (Cuvier; Gyrocotyle meandrica Herrera, 1946 of Callorhynchus callorhynchus (L.,Acanthobothrium dasybati Yamaguti, 1934 and Pterobothriidae unidentified, of an indeterminate ray; three types of larvae of Trypanorrhyncha and type of Proteocephalidea, of Cynoscion striatus (Cuv. and C. leiarchus; Proteocephalus jandia Woodland, 1934 of an indeterminate catfish; Monticellia siluri (Furhrmann, 1916 and Amphoteromorphus praeputialis sp. n. of Cetopsis caecutiens and Nomimoscolex magna sp. n. of Pimelodus clarias.

  5. Apoio Matricial: um estudo bibliográfico

    Directory of Open Access Journals (Sweden)

    Alexandra Iglesias

    2014-09-01

    Full Text Available Este artigo constitui-se de um estudo de revisão bibliográfica a respeito do apoio matricial em saúde mental. Foi realizada uma busca nas bases de dados da Biblioteca Virtual da Saúde - Lilacs e SciELO - e do Google acadêmico, com as palavras-chave "apoio matricial em saúde mental" e/ou "matriciamento em saúde mental". Foram encontrados 14 artigos com as características desejadas, o que evidencia o número restrito de publicações sobre o tema. Os artigos foram analisados quanto a sua parte estrutural e metodológica, destacando a predominância absoluta do uso do método qualitativo e dos profissionais de saúde como população alvo das pesquisas. Em seguida, estes mesmos artigos foram analisados quanto a suas discussões teóricas. Ressalta-se, dentre outras questões, a importância do apoio matricial para potencialização das equipes da atenção básica no cuidado às pessoas em sofrimento psíquico. Contudo, ainda são muitas as confusões quanto à proposta do apoio matricial e as responsabilidades compartilhadas entre equipes de Referências e profissionais de saúde mental, o que apontam para a necessidade de capacitação destes profissionais, além de uma melhor articulação e organização da rede de cuidado em saúde mental.

  6. Comparison of F(ab')2 versus Fab antivenom for pit viper envenomation: a prospective, blinded, multicenter, randomized clinical trial.

    Science.gov (United States)

    Bush, Sean P; Ruha, Anne-Michelle; Seifert, Steven A; Morgan, David L; Lewis, Brandon J; Arnold, Thomas C; Clark, Richard F; Meggs, William J; Toschlog, Eric A; Borron, Stephen W; Figge, Gary R; Sollee, Dawn R; Shirazi, Farshad M; Wolk, Robert; de Chazal, Ives; Quan, Dan; García-Ubbelohde, Walter; Alagón, Alejandro; Gerkin, Richard D; Boyer, Leslie V

    2015-01-01

    Crotalidae Polyvalent Immune Fab (Ovine) has been the only antivenom commercially available in the US since 2007 for treatment of Crotalinae envenomation. Late coagulopathy can occur or recur after clearance of Fab antivenom, often after hospital discharge, lasting in some cases more than 2 weeks. There have been serious, even fatal, bleeding complications associated with recurrence phenomena. Frequent follow-up is required, and additional intervention or hospitalization is often necessary. F(ab')2 immunoglobulin derivatives have longer plasma half life than do Fab. We hypothesized that F(ab')2 antivenom would be superior to Fab in the prevention of late coagulopathy following treatment of patients with Crotalinae envenomation. We conducted a prospective, double-blind, randomized clinical trial, comparing late coagulopathy in snakebitten patients treated with F(ab')2 with maintenance doses [F(ab')2/F(ab')2], or F(ab')2 with placebo maintenance doses [F(ab')2/placebo], versus Fab with maintenance doses [Fab/Fab]. The primary efficacy endpoint was coagulopathy (platelet count Fab/Fab cohort experienced late coagulopathy versus 4/39 (10.3%, p < 0.05) in the F(ab')2/F(ab')2 cohort and 2/38 (5.3%, p < 0.05) in the F(ab')2/placebo cohort. The lowest heterologous protein exposure was with F(ab')2/placebo. No serious adverse events were related to study drug. In each study arm, one patient experienced an acute serum reaction and one experienced serum sickness. In this study, management of coagulopathic Crotalinae envenomation with longer-half-life F(ab')2 antivenom, with or without maintenance dosing, reduced the risk of subacute coagulopathy and bleeding following treatment of envenomation.

  7. Single-ion 4f element magnetism: an ab-initio look at Ln(COT)2(-).

    Science.gov (United States)

    Gendron, Frédéric; Pritchard, Benjamin; Bolvin, Hélène; Autschbach, Jochen

    2015-12-14

    The electron densities associated with the Ln 4f shell, and spin and orbital magnetizations ('magnetic moment densities'), are investigated for the Ln(COT)2(-) series. The densities are obtained from ab-initio calculations including spin-orbit coupling. For Ln = Ce, Pr the magnetizations are also derived from crystal field models and shown to agree with the ab-initio results. Analysis of magnetizations from ab-initio calculations may be useful in assisting research on single molecule magnets.

  8. Radiolabeled F(ab')2-cetuximab for theranostic purposes in colorectal and skin tumor-bearing mice models.

    Science.gov (United States)

    Bellaye, P-S; Moreau, M; Raguin, O; Oudot, A; Bernhard, C; Vrigneaud, J-M; Dumont, L; Vandroux, D; Denat, F; Cochet, A; Brunotte, F; Collin, B

    2018-05-17

    This study aimed to investigate theranostic strategies in colorectal and skin cancer based on fragments of cetuximab, an anti-EGFR mAb, labeled with radionuclide with imaging and therapeutic properties, 111 In and 177 Lu, respectively. We designed F(ab') 2 -fragments of cetuximab radiolabeled with 111 In and 177 Lu. 111 In-F(ab') 2 -cetuximab tumor targeting and biodistribution were evaluated by SPECT in BalbC nude mice bearing primary colorectal tumors. The efficacy of 111 In-F(ab') 2 -cetuximab to assess therapy efficacy was performed on BalbC nude mice bearing colorectal tumors receiving 17-DMAG, an HSP90 inhibitor. Therapeutic efficacy of the radioimmunotherapy based on 177 Lu-F(ab') 2 -cetuximab was evaluated in SWISS nude mice bearing A431 tumors. Radiolabeling procedure did not change F(ab') 2 -cetuximab and cetuximab immunoreactivity nor affinity for HER1 in vitro. 111 In-DOTAGA-F(ab') 2 -cetuximab exhibited a peak tumor uptake at 24 h post-injection and showed a high tumor specificity determined by a significant decrease in tumor uptake after the addition of an excess of unlabeled-DOTAGA-F(ab') 2 -cetuximab. SPECT imaging of 111 In-DOTAGA-F(ab') 2 -cetuximab allowed an accurate evaluation of tumor growth and successfully predicted the decrease in tumor growth induced by 17-DMAG. Finally, 177 Lu-DOTAGA-F(ab') 2 -cetuximab radioimmunotherapy showed a significant reduction of tumor growth at 4 and 8 MBq doses. 111 In-DOTAGA-F(ab') 2 -cetuximab is a reliable and stable tool for specific in vivo tumor targeting and is suitable for therapy efficacy assessment. 177 Lu-DOTAGA-F(ab') 2 -cetuximab is an interesting theranostic tool allowing therapy and imaging.

  9. Trilayered Morphology of an ABC Triple Crystalline Triblock Terpolymer

    KAUST Repository

    Palacios, Jordana K.; Tercjak, Agnieszka; Liu, Guoming; Wang, Dujin; Zhao, Junpeng; Hadjichristidis, Nikolaos; Mü ller, Alejandro J.

    2017-01-01

    phase in the melt. Two crystallization protocols were employed to create particular crystalline morphologies. In both cases, the isothermal crystallization of the PLA block is induced first (at 81 °C, a temperature above the melting points of both PCL

  10. The development of the brake system of the BMW 850i including ABS and ASC. Entwicklung des Bremssystems des BMW 850i einschliesslich ABS und ASC

    Energy Technology Data Exchange (ETDEWEB)

    Kraft, H.J.; Leffler, H.

    1990-02-01

    The brake system of the new BMW 850i is described in the following. The brake actuation takes place via an hydraulic brake booster. The disc brakes at front and rear axle are arranged in diagnonal brake split. The 4-channel ABS is fitted as standard equipment. The ABS control unit also incorporates the algorithm for the Automatic Stability Control System ASC or ASC+T. The ASC+T shows improved traction compared with the pure stability system ASC and is standard in the BMW 850i with manual gear box. The automatic gear box equipped BMW 850i are supplied with ASC, the ASC+T is available as an option. Both systems, the ASC and the ASC+T are described with special view on the electronical and hydraulical network in the car. A performance comparison of the ASC-systems completes the description. (orig.).

  11. Many-body optimization using an ab initio monte carlo method.

    Science.gov (United States)

    Haubein, Ned C; McMillan, Scott A; Broadbelt, Linda J

    2003-01-01

    Advances in computing power have made it possible to study solvated molecules using ab initio quantum chemistry. Inclusion of discrete solvent molecules is required to determine geometric information about solute/solvent clusters. Monte Carlo methods are well suited to finding minima in many-body systems, and ab initio methods are applicable to the widest range of systems. A first principles Monte Carlo (FPMC) method was developed to find minima in many-body systems, and emphasis was placed on implementing moves that increase the likelihood of finding minimum energy structures. Partial optimization and molecular interchange moves aid in finding minima and overcome the incomplete sampling that is unavoidable when using ab initio methods. FPMC was validated by studying the boron trifluoride-water system, and then the method was used to examine the methyl carbenium ion in water to demonstrate its application to solvation problems.

  12. Ab-initio calculations of superconducting properties of YBa2Cu3O7

    International Nuclear Information System (INIS)

    Zhao, G.L.; Bagayoko, D.

    1999-01-01

    The authors present ab-initio calculations for the electronic structure and superconducting properties of YBa 2 Cu 3 O 7 (YBCO). The electronic structure was calculated using a self-consistent ab-initio LCAO method. They solved the anisotropic Eliashberg gap equation numerically. The strong coupling of the high energy optical phonons around 60--73 meV, with the electrons at the Fermi surface, leads to a high Tc in YBCO. The calculated Tc is about 89 K for μ* = 0.1. The good agreement of the calculated results with experimental measurements and the ab-initio nature of the calculations support the scenario of an anisotropic s-wave superconductor for YBCO

  13. Inelastic neutron scattering an ab-initio calculation of negative thermal expansion in Ag2O

    International Nuclear Information System (INIS)

    Gupta, M.K.; Mittal, R.; Rols, S.; Chaplot, S.L.

    2012-01-01

    The compound Ag 2 O undergoes large and isotropic negative thermal expansion over 0-500 K. We report temperature dependent inelastic neutron scattering measurements and ab-initio calculations of the phonon spectrum. The temperature dependence of the experimental phonon spectrum shows strong anharmonic nature of phonon modes of energy around 2.4 meV. The ab-initio calculations reveal that the maximum negative Grüneisen parameter, which is a measure of the relevant anharmonicity, occurs for the transverse phonon modes that involve bending motions of the Ag 4 O tetrahedra. The thermal expansion is evaluated from the ab-initio calculation of the pressure dependence of the phonon modes, and found in good agreement with available experimental data.

  14. Ab initio calculations of 3H(d,n)4He fusion

    International Nuclear Information System (INIS)

    Navratil, Petr; Quaglioni, Sofia

    2012-01-01

    We build a new ab initio many-body approach capable of describing simultaneously both bound and scattering states in light nuclei, by combining the resonating-group method with the ab initio no-core shell model. In this way, we complement a microscopic-cluster technique with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters. We will present the first results of the d- 3 H and d- 3 He fusion calculation obtained within our ab initio approach. We will also discuss our d- 4 He, 3 H- 4 He and 3 H- 3 H scattering calculations and the outline of the extension of the formalism to include three-cluster final states with the goal to calculate the 3 H( 3 H,2n) 4 He cross section

  15. Shear stiffness in nanolaminar Ti3SiC2 challenges ab initio calculations

    International Nuclear Information System (INIS)

    Kisi, E H; Zhang, J F; Kirstein, O; Riley, D P; Styles, M J; Paradowska, A M

    2010-01-01

    Nanolaminates such as the M n+1 AX n (MAX) phases are a material class with ab initio derived elasticity tensors published for over 250 compounds. We have for the first time experimentally determined the full elasticity tensor of the archetype MAX phase, Ti 3 SiC 2 , using polycrystalline samples and in situ neutron diffraction. The experimental elastic constants show extreme shear stiffness, with c 44 more than five times greater than expected for an isotropic material. Such shear stiffness is quite rare in hexagonal materials and strongly contradicts the predictions of all published MAX phase elastic constants derived from ab initio calculations. It is concluded that second order properties such as elastic moduli derived from ab initio calculations require careful experimental verification. The diffraction technique used currently provides the only method of verification for the elasticity tensor for the majority of new materials where single crystals are not available. (fast track communication)

  16. Ab initio/interpolated quantum dynamics on coupled electronic states with full configuration interaction wave functions

    International Nuclear Information System (INIS)

    Thompson, K.; Martinez, T.J.

    1999-01-01

    We present a new approach to first-principles molecular dynamics that combines a general and flexible interpolation method with ab initio evaluation of the potential energy surface. This hybrid approach extends significantly the domain of applicability of ab initio molecular dynamics. Use of interpolation significantly reduces the computational effort associated with the dynamics over most of the time scale of interest, while regions where potential energy surfaces are difficult to interpolate, for example near conical intersections, are treated by direct solution of the electronic Schroedinger equation during the dynamics. We demonstrate the concept through application to the nonadiabatic dynamics of collisional electronic quenching of Li(2p). Full configuration interaction is used to describe the wave functions of the ground and excited electronic states. The hybrid approach agrees well with full ab initio multiple spawning dynamics, while being more than an order of magnitude faster. copyright 1999 American Institute of Physics

  17. Sustainability of Recycled ABS and PA6 by Banana Fiber Reinforcement: Thermal, Mechanical and Morphological Properties

    Science.gov (United States)

    Singh, Rupinder; Kumar, Ranvijay; Ranjan, Nishant

    2018-01-01

    In the present study efforts have been made to prepare functional prototypes with improved thermal, mechanical and morphological properties from polymeric waste for sustainability. The primary recycled acrylonitrile butadiene styrene (ABS) and polyamide 6 (PA6) has been selected as matrix material with bio-degradable and bio-compatible banana fibers (BF) as reinforcement. The blend (in form of feed stock filament wire) of ABS/PA6 and BF was prepared in house by conventional twin screw extrusion (TSE) process. Finally feed stock filament of ABS/PA6 reinforced with BF was put to run on open source fused deposition modelling based three dimensional printer (without any change in hardware/software of the system) for printing of functional prototypes with improved thermal/mechanical/morphological properties. The results are supported by photomicrographs, thermographs and mechanical testing.

  18. Equine Immunoglobulin and Equine Neutralizing F(ab')₂ Protect Mice from West Nile Virus Infection.

    Science.gov (United States)

    Cui, Jiannan; Zhao, Yongkun; Wang, Hualei; Qiu, Boning; Cao, Zengguo; Li, Qian; Zhang, Yanbo; Yan, Feihu; Jin, Hongli; Wang, Tiecheng; Sun, Weiyang; Feng, Na; Gao, Yuwei; Sun, Jing; Wang, Yanqun; Perlman, Stanley; Zhao, Jincun; Yang, Songtao; Xia, Xianzhu

    2016-12-18

    West Nile virus (WNV) is prevalent in Africa, Europe, the Middle East, West Asia, and North America, and causes epidemic encephalitis. To date, no effective therapy for WNV infection has been developed; therefore, there is urgent need to find an efficient method to prevent WNV disease. In this study, we prepared and evaluated the protective efficacy of immune serum IgG and pepsin-digested F(ab')₂ fragments from horses immunized with the WNV virus-like particles (VLP) expressing the WNV M and E proteins. Immune equine F(ab')₂ fragments and immune horse sera efficiently neutralized WNV infection in tissue culture. The passive transfer of equine immune antibodies significantly accelerated the virus clearance in the spleens and brains of WNV infected mice, and reduced mortality. Thus, equine immunoglobulin or equine neutralizing F(ab')₂ passive immunotherapy is a potential strategy for the prophylactic or therapeutic treatment of patients infected with WNV.

  19. Exploring the speed and performance of molecular replacement with AMPLE using QUARK ab initio protein models

    Energy Technology Data Exchange (ETDEWEB)

    Keegan, Ronan M. [STFC Rutherford Appleton Laboratory, Didcot OX11 0FA (United Kingdom); Bibby, Jaclyn; Thomas, Jens [University of Liverpool, Liverpool L69 7ZB (United Kingdom); Xu, Dong [Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037 (United States); Zhang, Yang [University of Michigan, Ann Arbor, MI 48109 (United States); Mayans, Olga [University of Liverpool, Liverpool L69 7ZB (United Kingdom); Winn, Martyn D. [Science and Technology Facilities Council Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Rigden, Daniel J., E-mail: drigden@liv.ac.uk [University of Liverpool, Liverpool L69 7ZB (United Kingdom); STFC Rutherford Appleton Laboratory, Didcot OX11 0FA (United Kingdom)

    2015-02-01

    Two ab initio modelling programs solve complementary sets of targets, enhancing the success of AMPLE with small proteins. AMPLE clusters and truncates ab initio protein structure predictions, producing search models for molecular replacement. Here, an interesting degree of complementarity is shown between targets solved using the different ab initio modelling programs QUARK and ROSETTA. Search models derived from either program collectively solve almost all of the all-helical targets in the test set. Initial solutions produced by Phaser after only 5 min perform surprisingly well, improving the prospects for in situ structure solution by AMPLE during synchrotron visits. Taken together, the results show the potential for AMPLE to run more quickly and successfully solve more targets than previously suspected.

  20. Virtual synthesis of crystals using ab initio MD: Case study on LiFePO4

    Science.gov (United States)

    Mishra, S. B.; Nanda, B. R. K.

    2017-05-01

    Molecular dynamics simulation technique is fairly successful in studying the structural aspects and dynamics of fluids. Here we study the ability of ab initio molecular dynamics (ab initio MD) to carry out virtual experiments to synthesize new crystalline materials and to predict their structures. For this purpose the olivine phosphate LiFePO4 (LFPO) is used as an example. As transition metal oxides in general are stabilized with layered geometry, we carried out ab initio MD simulations over a hypothetical layered configuration consisting of alternate LiPO2 and FeO2 layers. With intermittent steps of electron minimization, the resulted equilibrium lattice consist of PO4 tetrahedra and distorted Fe-O complexes similar to the one observed in the experimental lattice.

  1. Comparison of Directigen Flu A+B with Real Time PCR in the Diagnosis of Influenza.

    Science.gov (United States)

    Bosevska, Golubinka; Panovski, Nikola; Janceska, Elizabeta; Mikik, Vladimir; Topuzovska, Irena Kondova; Milenkovik, Zvonko

    2015-01-01

    Early diagnosis and treatment of patients with influenza is the reason why physicians need rapid high-sensitivity influenza diagnostic tests that require no complex lab equipment and can be performed and interpreted within 15 min. The Aim of this study was to compare the rapid Directigen Flu A+B test with real time PCR for detection of influenza viruses in the Republic of Macedonia. One-hundred-eight respiratory samples (combined nose and throat swabs) were routinely collected for detection of influenza virus during influenza seasons. Forty-one patients were pediatric cases and 59 were adult. Their mean age was 23 years. The patients were allocated into 6 age groups: 0-4 yrs, 5-9 yrs, 10-14 yrs, 15-19 yrs, 20-64 yrs and > 65 yrs. Each sample was tested with Directigen Flu A+B and CDC real time PCR kit for detection and typisation/subtypisation of influenza according to the lab diagnostic protocol. Directigen Flu A+B identified influenza A virus in 20 (18.5%) samples and influenza B virus in two 2 (1.9%) samples. The high specificity (100%) and PPV of Directigen Flu A+B we found in our study shows that the positive results do not need to be confirmed. The overall sensitivity of Directigen Flu A+B is 35.1% for influenza A virus and 33.0% for influenza B virus. The sensitivity for influenza A is higher among children hospitalized (45.0%) and outpatients (40.0%) versus adults. Directigen Flu A+B has relatively low sensitivity for detection of influenza viruses in combined nose and throat swabs. Negative results must be confirmed.

  2. Field-evolved resistance to Cry1Ab maize by Spodoptera frugiperda in Brazil.

    Science.gov (United States)

    Omoto, Celso; Bernardi, Oderlei; Salmeron, Eloisa; Sorgatto, Rodrigo J; Dourado, Patrick M; Crivellari, Augusto; Carvalho, Renato A; Willse, Alan; Martinelli, Samuel; Head, Graham P

    2016-09-01

    The first Bt maize in Brazil was launched in 2008 and contained the MON 810 event, which expresses Cry1Ab protein. Although the Cry1Ab dose in MON 810 is not high against fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), MON 810 provided commercial levels of control. To support insect resistance management in Brazil, the baseline and ongoing susceptibility of FAW was examined using protein bioassays, and the level of control and life history parameters of FAW were evaluated on MON 810 maize. Baseline diet overlay assays with Cry1Ab (16 µg cm(-2) ) caused 76.3% mortality to field FAW populations sampled in 2009. Moderate mortality (48.8%) and significant growth inhibition (88.4%) were verified in leaf-disc bioassays. In greenhouse trials, MON 810 had significantly less damage than non-Bt maize. The surviving FAW larvae on MON 810 (22.4%) had a 5.5 day increase in life cycle time and a 24% reduction in population growth rate. Resistance monitoring (2010-2015) showed a significant reduction in Cry1Ab susceptibility of FAW over time. Additionally, a significant reduction in the field efficacy of MON 810 maize against FAW was observed in different regions from crop season 2009 to 2013. The decrease in susceptibility to Cry1Ab was expected, but the specific contributions to this resistance by MON 810 maize cannot be distinguished from cross-resistance to Cry1Ab caused by exposure to Cry1F maize. Technologies combining multiple novel insecticidal traits with no cross-resistance to the current Cry1 proteins and high activity against the same target pests should be pursued in Brazil and similar environments. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  3. Combined glaucoma and cataract surgery: Comparison of viscocanalostomy, endocyclophotocoagulation, and ab interno trabeculectomy.

    Science.gov (United States)

    Moghimi, Sasan; Hamzeh, Nikoo; Mohammadi, Massood; Khatibi, Nassim; Bowd, Christopher; Weinreb, Robert N

    2018-05-01

    To compare outcomes of phacoemulsification combined with viscocanalostomy, endocyclophotocoagulation (ECP), or ab interno trabulectomy for intraocular pressure (IOP) control and safety in eyes with open-angle glaucoma and visually significant cataract. Farabi Eye Hospital, Tehran, Iran. Retrospective case series. Medical records of patients who had combined surgery and were followed for at least 1 year were reviewed. Complete success, postoperative IOP, number of medications at each visit, and complications were evaluated and compared before and after adjustments for confounders. Forty-six eyes had combined phacoviscocanalostomy, 35 had phaco-ECP, and 28 eyes phaco-ab interno trabulectomy. The groups were matched for baseline IOP (P = .24). At the final follow-up (mean 17.2 months ± 5.5 [SD]), the phacoviscocanalostomy group had the lowest mean IOP (13.5 ± 4.7 mm Hg, 29% decrease) (P = .01). There was no significant difference in the final IOP between phaco-ECP and phaco-ab interno trabulectomy (16.4 ± 3.9 mm Hg, 20% decrease versus 15.8 ± 4.2 mm Hg, 15% decrease) (P = .88). The reduction in the number of medications was greater with phacoviscocanalostomy (77%) than with phaco-ECP (40%) and phaco-ab interno trabulectomy (44%) (P = .01). Phacoemulsification-ab interno trabulectomy had the fewest complications. Intraocular pressure spikes were more frequent in the phaco-ECP group (20%) than in the other groups (4%) (P = .05). All procedures significantly lowered IOP. Phacoemulsification-ab interno trabulectomy resulted in fewest complications and phacoviscocanalostomy led to the largest IOP drop and largest reduction of medications. Copyright © 2018 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  4. The mechanochemical cycle of mammalian kinesin-2 KIF3A/B under load

    Science.gov (United States)

    Andreasson, Johan O.L.; Shastry, Shankar; Hancock, William O.; Block, Steven M.

    2015-01-01

    Summary The response of motor proteins to external loads underlies their ability to work in teams and determines the net speed and directionality of cargo transport. The mammalian kinesin-2, KIF3A/B, is a heterotrimeric motor involved in intraflagellar transport and vesicle motility in neurons. Bidirectional cargo transport is known to result from the opposing activities of KIF3A/B and dynein bound to the same cargo, but the load-dependent properties of kinesin-2 are poorly understood. We used a feedback-controlled optical trap to probe the velocity, run length and unbinding kinetics of mouse KIF3A/B under various loads and nucleotide conditions. The kinesin-2 motor velocity is less sensitive than kinesin-1 to external forces, but its processivity diminishes steeply with load, and the motor was observed occasionally to slip and reattach. Each motor domain was characterized by studying homodimeric constructs, and a global fit to the data resulted in a comprehensive pathway that quantifies the principal force-dependent kinetic transitions. The properties of the KIF3A/B heterodimer are intermediate between the two homodimers, and the distinct load-dependent behavior is attributable to the properties of the motor domains, and not to the neck-linkers or the coiled-coil stalk. We conclude that the force-dependent movement of KIF3A/B differs significantly from conventional kinesin-1. Against opposing dynein forces, KIF3A/B motors are predicted to rapidly unbind and rebind, resulting in qualitatively different transport behavior from kinesin-1. PMID:25866395

  5. Modelling of nuclear glasses by classical and ab initio molecular dynamics; Modelisation de verres intervenant dans le conditionnement des dechets radioactifs par dynamiques moleculaires classique et ab initio

    Energy Technology Data Exchange (ETDEWEB)

    Ganster, P

    2004-10-15

    A calcium aluminosilicate glass of molar composition 67 % SiO{sub 2} - 12 % Al{sub 2}O{sub 3} - 21 % CaO was modelled by classical and ab initio molecular dynamics. The size effect study in classical MD shows that the systems of 100 atoms are more ordered than the larger ones. These effects are mainly due to the 3-body terms in the empirical potentials. Nevertheless, these effects are small and the structures generated are in agreement with experimental data. In such kind of glass, we denote an aluminium avoidance and an excess of non bridging oxygens which can be compensated by tri coordinated oxygens. When the dynamics of systems of 100 and 200 atoms is followed by ab initio MD, some local arrangements occurs (bond length, angular distributions). Thus, more realistic vibrational properties are obtained in ab initio MD. The modelling of thin films shows that aluminium atoms extend to the most external part of the surface and they are all tri-coordinated. Calcium atoms are set in the sub layer part of the surface and they produce a depolymerization of the network. In classical MD, tri-coordinated aluminium atoms produce an important electric field above the surface. With non bridging oxygens, they constitute attractive sites for single water molecules. (author)

  6. Pilot study of 68Ga-DOTA-F(ab?)2-trastuzumab in patients with breast cancer

    OpenAIRE

    Beylergil, Volkan; Morris, Patrick G.; Smith-Jones, Peter M.; Modi, Shanu; Solit, David; Hudis, Clifford A.; Lu, Yang; O?Donoghue, Joseph; Lyashchenko, Serge K.; Carrasquillo, Jorge A.; Larson, Steven M.; Akhurst, Timothy J.

    2013-01-01

    Objective 68Ga-1,4,7,10-Tetraazacyclododecane-N,N?,N??,N???-tetraacetic acid (DOTA)-F(ab?)2-trastuzumab [68Ga-DOTA-F(ab?)2-trastuzumab] has been developed at our institution as a positron imaging reagent for assessing human epidermal growth factor receptor 2 (HER2) expression status by in-vivo imaging. Initial studies on animals demonstrated promising results in the monitoring of treatment response to heat shock protein 90-targeted drugs that inhibit the client protein HER2. We report here ou...

  7. Ab Initio Calculations and Raman and SERS Spectral Analyses of Amphetamine Species

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Nørbygaard, Thomas; White, Peter C.

    2011-01-01

    For the first time, the differences between the spectra of amphetamine and amphetamine-H+ and between different conformers are thoroughly studied by ab initio model calculations, and Raman and surface-enhanced Raman spectroscopy (SERS) spectra are measured for different species of amphetamine....... The spectra of amphetamine and amphetamine-H+ sampleswere obtained and assigned according to a comparison of the experimental spectra and the ab initio MO calculations, performed using the Gaussian 03W program (Gaussian, Inc., Pittsburgh, PA). The analyses were based on complete geometry minimization...

  8. Exploring the ab initio/classical free energy perturbation method: The hydration free energy of water

    International Nuclear Information System (INIS)

    Sakane, Shinichi; Yezdimer, Eric M.; Liu, Wenbin; Barriocanal, Jose A.; Doren, Douglas J.; Wood, Robert H.

    2000-01-01

    The ab initio/classical free energy perturbation (ABC-FEP) method proposed previously by Wood et al. [J. Chem. Phys. 110, 1329 (1999)] uses classical simulations to calculate solvation free energies within an empirical potential model, then applies free energy perturbation theory to determine the effect of changing the empirical solute-solvent interactions to corresponding interactions calculated from ab initio methods. This approach allows accurate calculation of solvation free energies using an atomistic description of the solvent and solute, with interactions calculated from first principles. Results can be obtained at a feasible computational cost without making use of approximations such as a continuum solvent or an empirical cavity formation energy. As such, the method can be used far from ambient conditions, where the empirical parameters needed for approximate theories of solvation may not be available. The sources of error in the ABC-FEP method are the approximations in the ab initio method, the finite sample of configurations, and the classical solvent model. This article explores the accuracy of various approximations used in the ABC-FEP method by comparing to the experimentally well-known free energy of hydration of water at two state points (ambient conditions, and 973.15 K and 600 kg/m3). The TIP4P-FQ model [J. Chem. Phys. 101, 6141 (1994)] is found to be a reliable solvent model for use with this method, even at supercritical conditions. Results depend strongly on the ab initio method used: a gradient-corrected density functional theory is not adequate, but a localized MP2 method yields excellent agreement with experiment. Computational costs are reduced by using a cluster approximation, in which ab initio pair interaction energies are calculated between the solute and up to 60 solvent molecules, while multi-body interactions are calculated with only a small cluster (5 to 12 solvent molecules). Sampling errors for the ab initio contribution to

  9. Atomic carbon chains as spin-transmitters: An ab initio transport study

    DEFF Research Database (Denmark)

    Fürst, Joachim Alexander; Brandbyge, Mads; Jauho, Antti-Pekka

    2010-01-01

    An atomic carbon chain joining two graphene flakes was recently realized in a ground-breaking experiment by Jin et al. (Phys. Rev. Lett., 102 (2009) 205501). We present ab initio results for the electron transport properties of such chains and demonstrate complete spin-polarization of the transmi......An atomic carbon chain joining two graphene flakes was recently realized in a ground-breaking experiment by Jin et al. (Phys. Rev. Lett., 102 (2009) 205501). We present ab initio results for the electron transport properties of such chains and demonstrate complete spin...

  10. The coherent interlayer resistance of a single, rotated interface between two stacks of AB graphite

    Energy Technology Data Exchange (ETDEWEB)

    Habib, K. M. Masum, E-mail: khabib@ee.ucr.edu; Sylvia, Somaia S.; Neupane, Mahesh; Lake, Roger K., E-mail: rlake@ee.ucr.edu [Department of Electrical Engineering, University of California, Riverside, California 92521-0204 (United States); Ge, Supeng [Department of Physics and Astronomy, University of California, Riverside, California 92521-0204 (United States)

    2013-12-09

    The coherent, interlayer resistance of a misoriented, rotated interface between two stacks of AB graphite is determined for a variety of misorientation angles. The quantum-resistance of the ideal AB stack is on the order of 1 to 10 mΩ μm{sup 2}. For small rotation angles, the coherent interlayer resistance exponentially approaches the ideal quantum resistance at energies away from the charge neutrality point. Over a range of intermediate angles, the resistance increases exponentially with cell size for minimum size unit cells. Larger cell sizes, of similar angles, may not follow this trend. The energy dependence of the interlayer transmission is described.

  11. The coherent interlayer resistance of a single, rotated interface between two stacks of AB graphite

    International Nuclear Information System (INIS)

    Habib, K. M. Masum; Sylvia, Somaia S.; Neupane, Mahesh; Lake, Roger K.; Ge, Supeng

    2013-01-01

    The coherent, interlayer resistance of a misoriented, rotated interface between two stacks of AB graphite is determined for a variety of misorientation angles. The quantum-resistance of the ideal AB stack is on the order of 1 to 10 mΩ μm 2 . For small rotation angles, the coherent interlayer resistance exponentially approaches the ideal quantum resistance at energies away from the charge neutrality point. Over a range of intermediate angles, the resistance increases exponentially with cell size for minimum size unit cells. Larger cell sizes, of similar angles, may not follow this trend. The energy dependence of the interlayer transmission is described

  12. Metode Abû Dâwud Dalam Menulis Al-Sunan

    OpenAIRE

    Ma'sum, Ma'sum

    2011-01-01

    In this paper the author will reveal one of the prominent figures who have long been through the mill of hadith more over the quality of his knowledge in this field does not need to worry about, Abû Dâwud made a large contribution which includes hadith of the prophet in the his book. This study on the book of hadith methodology writing is owned by Abû Dâwud hadith have found some result of hadîth da‘îf that contained therein. the indication of hadîth da‘îf loading (also mawdû‘ according to Ib...

  13. Metode Abû Dâwud dalam Menulis al-Sunan

    OpenAIRE

    Ma'sum Ma'sum

    2015-01-01

    In this paper the author will reveal one of the prominent figures who have long been through the mill of hadith more over the quality of his knowledge in this field does not need to worry about, Abû Dâwud made a large contribution which includes hadith of the prophet in the his book. This study on the book of hadith methodology writing is owned by Abû Dâwud hadith have found some result of hadîth da‘îf that contained therein. the indication of hadîth da‘îf loading (also mawdû‘ according to Ib...

  14. Studies of urea geometry by means of ab initio methods and computer simulations of liquids

    OpenAIRE

    Cirino, José Jair Vianna; Bertran, Celso Aparecido

    2002-01-01

    A study was carried out on the urea geometries using ab initio calculation and Monte Carlo computational simulation of liquids. The ab initio calculated results showed that urea has a non-planar conformation in the gas phase in which the hydrogen atoms are out of the plane formed by the heavy atoms. Free energies associated to the rotation of the amino groups of urea in water were obtained using the Monte Carlo method in which the thermodynamic perturbation theory is implemented. The magnitud...

  15. Radioimmunoassay of antibody e against hepatitis-B virus (HBeAb, anti-HBe)

    International Nuclear Information System (INIS)

    Kselikova, M.; Novak, J.; Urbankova, J.

    1981-01-01

    The Abbott-HBe kit renders possible a radioimmunoassay of antibody e against antigen e of the hepatitis-B virus. This detection proceeds in 2 phases: the higher the antibody-e titer in the examined serum the lower the number of pulses measured. HBeAb occurred in 87 test persons. The antibody was most frequently detected in symptom-free carriers of the surface antigen (80%), furthermore in the medical staff of the departments of infectious hepatitides (39%), in hospitalized patients with infectious hepatitis (36%), and in employees of the first-aid service (25%). In blood donors as control group HBeAb was not detected. (author)

  16. Ab initio study of H + + H 2 collisions: Elastic/inelastic and charge transfer processes

    Science.gov (United States)

    Saieswari, A.; Kumar, Sanjay

    2007-12-01

    An ab initio full configuration interaction study has been undertaken to obtain the global potential energy surfaces for the ground and the first excited electronic state of the H + + H 2 system employing Dunning's cc-pVQZ basis set. Using the ab initio approach the corresponding quasi-diabatic potential energy surfaces and coupling potentials have been obtained. A time-independent quantum mechanical study has been also undertaken for both the inelastic and charge transfer processes at the experimental collision energy Ec.m. = 20.0 eV and the preliminary results show better agreement with the experimental data as compared to the earlier available theoretical studies.

  17. New tool for spreading proteins to the environment: Cry1Ab toxin immobilized to bioplastics.

    Science.gov (United States)

    Moldes, Cristina; Farinós, Gema P; de Eugenio, Laura I; García, Pedro; García, José L; Ortego, Félix; Hernández-Crespo, Pedro; Castañera, Pedro; Prieto, María A

    2006-08-01

    A new tool to provide an environmentally friendly way to deliver active proteins to the environment has been developed, based on the use of polyhydroxyalkanoate (PHA, bioplastic) granules. To illustrate this novel approach, a derived Cry1Ab insect-specific toxin protein was in vivo immobilized into PHA granules through the polypeptide tag BioF. The new toxin, named Fk-Bt1, was shown to be active against Sesamia nonagrioides (Lepidoptera: Noctuidae). The dose-mortality responses of the new toxin granule formulation (PFk-Bt1) and purified Cry1Ab have been compared, demonstrating the effectiveness of PFk-Bt1 and suggesting a common mode of action.

  18. Attenuation coefficient determination of printed ABS and PLA samples in diagnostic radiology standard beams

    International Nuclear Information System (INIS)

    Veneziani, G.R.; Correa, E.L.; Potiens, M.P.A.; Campos, L.L.

    2015-01-01

    IAEA code of practice TRS-457 states that standard phantoms should offer the same primary attenuation and scatter production as relevant body section of a representative patient. Material cost, availability and dimensional stability must also be considered. The goal of this study is to determine the attenuation coefficient of printed ABS and PLA in standard X-ray beams, verifying if phantoms printed with these materials could be an easier-handle substitute for PMMA, enabling the creation of different designs in an easier and cheaper way. Results show that PMMA presents higher attenuation coefficient, followed by PLA and ABS, which means that thinner PMMA layer creates higher radiation attenuation. (author)

  19. A case study to estimate thermal conductivity of ABS in Cold Climate Chamber

    OpenAIRE

    Mughal, Umair Najeeb; Makarova, Marina; Virk, Muhammad Shakeel; Polanco Pinerez, Geanette

    2015-01-01

    Open Access (Romeo Green journal), publishers version / PDF may be used http://www.scirp.org/journal/wjet/ Non steady state thermal conductivity of ABS was estimated using an analytical approach in a Cold Climate Chamber at ?10?C and ?14?C. Two hollow cylinders of ABS of varying thickness were used to estimate the conductivity. The material was porous but the porosity was unknown. This paper is a case study to understand, if it is reasonable to estimate the thermal conductivity using th...

  20. Post-exilic conflict as “possible” historical background to Psalm 69:10ab

    OpenAIRE

    Alphonso Groenewald

    2005-01-01

    As is the case with Psalm 8a, Psalm 69:10a, also commences with the emphatic particle kî. 10a and 10b are syndetically bound together by means of the conjunction “and”. What has already been stated in cola 8ab, is repeated and even expressed in clearer terms in these cola (10ab). The supplicant does not believe that he deserves his present distress. Actually, the distress and insult he is enduring come as a direct result of his devotion to God and God’s service. Even his fasting and mourning ...