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Sample records for abs terpolymer estudo

  1. Macromolecular metallurgy of binary mesocrystals via designed multiblock terpolymers.

    Science.gov (United States)

    Xie, Nan; Liu, Meijiao; Deng, Hanlin; Li, Weihua; Qiu, Feng; Shi, An-Chang

    2014-02-26

    Self-assembling block copolymers provide access to the fabrication of various ordered phases. In particular, the ordered spherical phases can be used to engineer soft mesocrystals with domain size at the 5-100 nm scales. Simple block copolymers, such as diblock copolymers, form a limited number of mesocrystals. However multiblock copolymers are capable to form more complex mesocrystals. We demonstrate that designed B1AB2CB3 multiblock terpolymers, in which the A- and C-blocks form spherical domains and the packing of these spheres can be controlled by changing the lengths of the middle and terminal B-blocks, self-assemble into various binary mesocrystals with space group symmetries of a large number of binary ionic crystals, including NaCl, CsCl, ZnS, α-BN, AlB2, CaF2, TiO2, ReO3, Li3Bi, Nb3Sn(A15), and α-Al2O3. This approach can be generalized to other terpolymers as well as to tetrapolymers to obtain ternary mesocrystals. Our study provides a new concept of macromolecular metallurgy for producing crystal phases in a mesoscale and thus makes multiblock copolymers a robust platform for the engineering of functional materials.

  2. Stability of the Frank-Kasper σ-phase in BABC linear tetrablock terpolymers.

    Science.gov (United States)

    Liu, Meijiao; Li, Weihua; Qiu, Feng; Shi, An-Chang

    2016-08-14

    The phase behavior of B1AB2C tetrablock terpolymer melts is systematically studied using the self-consistent field theory, focusing on the emergence and stability of the complex Frank-Kasper σ-phase. Our study starts with an investigation of the stability region of the σ phase for a generic model of B1AB2C terpolymers, in which the C-blocks form spherical domains immersed in the A/B matrix. Then, we examine the stability of the σ phase for a model system with a specific set of parameters mimicking poly(styrene-b-isoprene-b-styrene-b-ethylene oxide) (SISO) block copolymers which were examined in recent experiments. Our results reveal that the formation of the σ phase is mainly governed by two factors. The first factor is the conformational asymmetry between the A/B-blocks and the C-block, similar to that in conformationally asymmetric AB-type block copolymers. The second factor is the specific chain architecture of B1AB2C. The tetrablock architecture with a specific set of interaction parameters and compositions leads to the formation of large core-shell spherical domains, which amplifies the effect of interfacial energy and thereby stabilizes the σ phase. PMID:27396494

  3. 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.

  4. Rational design of ABC triblock terpolymer solution nanostructures with controlled patch morphology

    Science.gov (United States)

    Löbling, Tina I.; Borisov, Oleg; Haataja, Johannes S.; Ikkala, Olli; Gröschel, André H.; Müller, Axel H. E.

    2016-01-01

    Block copolymers self-assemble into a variety of nanostructures that are relevant for science and technology. While the assembly of diblock copolymers is largely understood, predicting the solution assembly of triblock terpolymers remains challenging due to complex interplay of block/block and block/solvent interactions. Here we provide guidelines for the self-assembly of linear ABC triblock terpolymers into a large variety of multicompartment nanostructures with C corona and A/B cores. The ratio of block lengths NC/NA thereby controls micelle geometry to spheres, cylinders, bilayer sheets and vesicles. The insoluble blocks then microphase separate to core A and surface patch B, where NB controls the patch morphology to spherical, cylindrical, bicontinuous and lamellar. The independent control over both parameters allows constructing combinatorial libraries of unprecedented solution nanostructures, including spheres-on-cylinders/sheets/vesicles, cylinders-on-sheets/vesicles, and sheets/vesicles with bicontinuous or lamellar membrane morphology (patchy polymersomes). The derived parameters provide a logical toolbox towards complex self-assemblies for soft matter nanotechnologies. PMID:27352897

  5. Rational design of ABC triblock terpolymer solution nanostructures with controlled patch morphology

    Science.gov (United States)

    Löbling, Tina I.; Borisov, Oleg; Haataja, Johannes S.; Ikkala, Olli; Gröschel, André H.; Müller, Axel H. E.

    2016-06-01

    Block copolymers self-assemble into a variety of nanostructures that are relevant for science and technology. While the assembly of diblock copolymers is largely understood, predicting the solution assembly of triblock terpolymers remains challenging due to complex interplay of block/block and block/solvent interactions. Here we provide guidelines for the self-assembly of linear ABC triblock terpolymers into a large variety of multicompartment nanostructures with C corona and A/B cores. The ratio of block lengths NC/NA thereby controls micelle geometry to spheres, cylinders, bilayer sheets and vesicles. The insoluble blocks then microphase separate to core A and surface patch B, where NB controls the patch morphology to spherical, cylindrical, bicontinuous and lamellar. The independent control over both parameters allows constructing combinatorial libraries of unprecedented solution nanostructures, including spheres-on-cylinders/sheets/vesicles, cylinders-on-sheets/vesicles, and sheets/vesicles with bicontinuous or lamellar membrane morphology (patchy polymersomes). The derived parameters provide a logical toolbox towards complex self-assemblies for soft matter nanotechnologies.

  6. 40 CFR 721.9640 - Salt of an acrylic acid - acrylamide terpolymer (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Salt of an acrylic acid - acrylamide... Specific Chemical Substances § 721.9640 Salt of an acrylic acid - acrylamide terpolymer (generic). (a... generically as salt of an acrylic acid - acrylamide terpolymer (PMN P-99-817) is subject to reporting...

  7. Electrostriction and Crystalline Phase Transformations in a Vinylidene Flouride Terpolymer

    Science.gov (United States)

    Roland, C. M.; Garrett, J. T.; Qadri, S. B.

    Substantial electrostrictive strains can be obtained from terpolymers of vinylidene fluoride, trifluoroethylene, and chlorotrifluoroethylene. The mechanism of the electromechanical response was investigated using x-ray diffraction and infrared absorption measurements on the polymer under an electric field. While application of the field is found to induce changes in the crystal phase structure, the phase transition that can effect dimensional changes is too small to account for the magnitude of the electrostriction. Thus, the origin of the exceptional electromechanical properties of this material remains to be fully elucidated.

  8. Non-isothermal Kinetic Study of p-Cresol-Dithiooxamide-Formaldehyde Terpolymer

    OpenAIRE

    Gurnule, W. B.; S. S. Katkamwar

    2010-01-01

    Terpolymer (p-CDF) has been prepared by using the monomer p-cresol, dithiooxanude and formaldehyde in 1:1:2 molar proportions. The structure of p-CDF terpolymer has been elucidated on the basis of elemental analysis and various physicochemical technique like UV-visible, FTIR, 1H NMR and TG analysis. Detailed thermal degradation curve is discussed which shows four steps decomposition. The activation energy (Ea) and thermal stability calculated by using the Sharp Wentworth, Frceman-Carroll meth...

  9. Polydispersity-Driven Morphological Transitions in ABC Triblock Terpolymers

    Science.gov (United States)

    Meuler, Adam J.; Ellison, Christopher J.; Evans, Christopher M.; Hillmyer, Marc A.; Bates, Frank S.

    2008-03-01

    The use of synthetic polymerization techniques (e.g., controlled radical polymerizations) that often yield polydispersity indices greater than 1.1 is becoming more widespread. Advances in these methodologies have increased the number of monomers amenable to incorporation in block copolymers and will potentially drive commercial costs down. Since many block copolymer properties are governed by the underlying mesostructure, understanding the influence of polydispersity on morphological behavior should prove vital to the success of block copolymer commercialization efforts. This presentation will focus on polydispersity-driven morphological transitions in poly(isoprene-b-styrene-b-ethylene oxide) (ISO) triblock terpolymers. ISO triblocks with polydisperse polystyrene blocks were prepared by anionic polymerization and their morphological behavior was characterized using small-angle x-ray scattering and dynamic mechanical spectroscopy. Only lamellar microstructures were identified along the fI = fS isopleth for polydisperse ISO triblocks, while an orthorhombic network (O^70) was previously identified in monodisperse ISO triblocks.

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

    Energy Technology Data Exchange (ETDEWEB)

    Barroso-Bujans, F. [Instituto de Ciencia y Tecnologia de Polimeros, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain)], E-mail: fbarroso@ictp.csic.es; Verdejo, R.; Lozano, A. [Instituto de Ciencia y Tecnologia de Polimeros, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain); Fierro, J.L.G. [Instituto de Catalisis y Petroleoquimica, CSIC, Marie Curie 2, Cantoblanco, 28049 Madrid (Spain); Lopez-Manchado, M.A. [Instituto de Ciencia y Tecnologia de Polimeros, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain)

    2008-10-15

    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.

  11. Synthesis and Demulsibility of the Terpolymer Demulsifier of Acryl Resin

    Institute of Scientific and Technical Information of China (English)

    KANG,Wan-Li; MENG,Ling-Wei; ZHANG,Hong-Yan; LIU,Shu-Ren

    2008-01-01

    Terpolymer demulsifier of acryl resin has been synthesized through solution polymerization with water as a dissolvent,potassium persulfate as an initiator and the monomers of methyl methacrylate,butyl acrylate and acrylic acid as starting materials.The effects of the reaction temperature,dripping time,the amount of monomers and initiator on the dehydration rate of the demulsifier were investigated by an orthogonal experiment.It shows that the stronger influence on the dehydration rate among six factors is reaction temperature,dripping time,and amount of catalyst,while monomer has weak influence.The performance of the demulsifier was evaluated under different demulsification time,temperatures and concentrations of the screened demulsifiers.The result shows that the dehydration rate of the demulsifier can reach over 67%,which is better than that by the emulsion polymerization way.

  12. 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.

  13. Synthesis and Characterization of the Terpolymer of Itaconic Acid with Acrylamide and 2-Acrylamido-2-methylpropanesulfonic Acid

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The terpolymer of itaconic acid,acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid was synthesized through the free-radical polymerization.The IR spectra confirmed that there was no olefinic band,while the TGA results revealed that the terpolymer was of high thermal stability.

  14. Development of new multifunctional terpolymer sorbent for proteomics applications.

    Science.gov (United States)

    Najam-ul-Haq, Muhammad; Saeed, Adeela; Jabeen, Fahmida; Hussain, Dilshad; Khan, Naseem; Shabir, Maryam; Raza, Nadeem; Ashiq, Muhammad Naeem; Malana, Muhammad Aslam; Zafar, Zafar Iqbal

    2015-07-01

    Determination of the availability of phases for specific separations is an important task achieved by a separation chemist. This becomes vital when the complex samples like biofluids are dealt with in proteome science. The work presented here involves the synthesis and application of terpolymeric sorbent with different functionalizations adopted for the selective enrichment of biomolecules of interest from biological fluids. Synthesis of terpolymer was carried out by the radical polymerization of monomers: methyl acrylate, acrylic acid and vinyl acetate with diethylene glycol dimethacrylate as cross-linking agent, benzoyl peroxide as initiator and chloroform as a porogenic solvent. Characterization was done through Fourier transform infrared spectroscopy, scanning electron microscopy and nitrogen adsorption porosimetry. The polymer was further modified to immobilized metal ion affinity chromatographic material, with immobilized Fe(3+)/La(3+) ions that allowed phosphopeptide enrichment from tryptic digests of standard proteins as well as milk, egg yolk and human serum. Sensitivity of enrichment down to 50 fmol was achieved in the presence of complex protein background as bovine serum albumin. Hydrophobicity was introduced through octadecyl amine, which provides comparable results to ZipTip C18/C4 for desalting of complex mixtures of all caseins. Analysis of the enriched content was performed by Matrix Assisted Laser Desorption Ionization Mass Spectrometry (MALDI-MS). PMID:25402016

  15. 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.

  16. Synthesis and application of terpolymer bearing cyclic carbonate and cinnamoyl groups

    Science.gov (United States)

    Park, S. Y.; Park, H. Y.; Lee, H. S.; Park, S. W.; Park, D. W.

    2003-01-01

    We propose the syntheses of photopolymer with pendant cinnamic ester and cyclic carbonate groups by the addition reaction of poly(glycidyl methacrylate- co-styrene) with CO 2 and then with cinnamoyl chloride. Quaternary ammonium salts showed good catalytic activity for this synthesis. Photochemical reaction experiments revealed that terpolymer having cinnamate and cyclic carbonate groups has good photosensitivity, even in the absence of sensitizer. In order to expand the application of the obtained terpolymer, polymer blends with poly(methyl methacrylate) were prepared. Differential scanning calorimetry and optical clarity tests showed that the blends were miscible over the whole composition ranges.

  17. 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.

  18. 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.

  19. Synthesis and characterization of CdS nanocrystals in Maleic anhydride-Octene-1-Vinylbutyl Ether terpolymer matrix

    Science.gov (United States)

    Akperov, Oktay H.; Muradov, Mustafa B.; Malikov, Elvin Y.; Akperov, Elchin O.; Mammadova, Rasmiyya E.; Eyvazova, Goncha M.; Kukovecz, Ákos; Kónya, Zoltán

    2016-07-01

    A Maleic anhydride-Octene-1-Vinylbutyl Ether terpolymer was synthesized via the radical terpolymerization method in order to prepare a new matrix for CdS nanocrystal synthesis. CdS nanocrystals were synthesized through the reaction of thiourea with cadmium chloride. The synthesized terpolymer/CdS nanocrystal composites were characterized by several methods. Energy Dispersive X-ray analysis, Raman spectroscopy and powder X-ray diffraction methods. The room temperature UV-visible absorption spectra show a shift of the absorption edge towards higher energies. The band gap of the CdS nanocomposite is bigger than that of bulk CdS. Raman spectrum exhibits characteristic peaks of CdS. Images of the nanocomposite obtained with Atomic Force Microscopy and Transmission Electron Microscopy are the evidences of CdS nanocrystal formation in the terpolymer. Thermal investigation shows that the nanocomposite is more thermostable than the terpolymer which could be useful for application in thermo aggressive medium.

  20. 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.

  1. Thermal Degradation Studies of Terpolymer Derived from 2-Aminothiophenol, Hexamethylenediamine, and Formaldehyde

    Directory of Open Access Journals (Sweden)

    P. U. Belsare

    2014-01-01

    Full Text Available Terpolymer (2-ATPHMDAF-I has been synthesized by the condensation of 2-aminothiophenol and hexamethylenediamine with formaldehyde in the presence of 2 M hydrochloric acid as a catalyst with 1 : 1 : 2 molar proportion of reacting monomers. The structure of newly synthesized terpolymer has been elucidated and confirmed on the basis of elemental analysis and various spectral techniques, that is, UV-visible, FT-IR, and 1H-NMR spectroscopy. Number average molecular weight (Mn¯ has been determined by conductometric titration in nonaqueous medium. The viscosity measurements in dimethyl sulfoxide (DMSO have been carried out to ascertain the characteristic functions and constants. The studies have been further extended to nonisothermal thermogravimetric analysis for determination of their mode of decomposition and relative thermal stability. Activation energy Ea, order of reaction (n, and frequency factor (z were calculated by Friedman, Chang, Sharp-Wentworth and Freeman-Carroll methods. Activation energy calculated by Friedman and Chang methods are in close agreement with each other while the results obtained from Freeman-Carroll and Sharp-Wentworth’s methods are found to be in a similar order.

  2. Fotfavoriten AB

    OpenAIRE

    Søilen, Klaus Solberg; HUBER, Stefan

    2004-01-01

    Fotfavoriten AB, a foot care company located in Sollefttå in Northern Sweden, is an example of how local government fires staff only to reengage them as entrepreneurs delivering similar service. The case is typical for the social sector and may mark a trend. The result is often felt to be positive both by the entrepreneur, who is now more directly in charge of her or his earnings, and the end consumer. The CEO of Fotfavoriten AB, Eva Wörmann, waited a long time before she dared to take the ne...

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

    KAUST Repository

    Bouchekif, Hassen

    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

  4. ABS 497 Complete Class

    OpenAIRE

    admin

    2015-01-01

    ABS 497 Complete Class   To purchase this material click below link   http://www.assignmentcloud.com/ABS-497/ABS-497-Complete-Class-Guide   For more classes visit   www.assignmentcloud.com   ABS 497 Week 1 Assignment Community Change ABS 497 Week 1 DQ 1 Fabian's Story ABS 497 Week 1 DQ 2 Doug's Story ABS 497 Week 2 DQ 1 Parenting Styles ABS 497 Week 2 DQ 2 Ethnicity and Learning Theory ABS 497 Week 3 ...

  5. Phase Behavior of SIS'O Tetrablock Terpolymers: A Self-consistent Field Theory Study

    Science.gov (United States)

    Arora, Akash; Morse, David C.; Bates, Frank S.; Dorfman, Kevin D.

    Block copolymers with three or more blocks show richer phase behavior than diblock copolymers. In this work, we use self-consistent field theory (SCFT) to study the phase behavior of ABA' C type tetrablock terpolymers. In particular, we are motivated by experimental studies on poly(styrene- b-isoprene- b-styrene- b-ethylene oxide) (SIS'O) that report interesting phases such as core-shell spheres and cylinders, the Frank-Kasper σ phase, and the dodecagonal quasicrystalline morphology. We compare SCFT predictions to experimental results for SIS'O copolymers using values of the Flory-Huggins interaction parameters that are estimated from analysis of literature data on related systems.

  6. 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.

  7. 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.

  8. Corrosion Inhibitive Evaluation of an Environmentally Friendly Water-Base Acrylic Terpolymer on Mild Steel in Hydrochloric Acid Media

    Science.gov (United States)

    Azghandi, Mojtaba Vakili; Davoodi, Ali; Farzi, Gholam Ali; Kosari, Ali

    2013-12-01

    The corrosion inhibitive performance of an environmentally friendly water-base acrylic terpolymer [methyl methacrylate/Butyl Acrylate/Acrylic acid (ATP)] on mild steel in 1 M HCl was investigated by alternating current and direct current electrochemical techniques and the quantum chemical method. An efficiency of more than 97 pct was obtained with 0.8 mmol/L ATP. The increase in inhibitor concentration and immersion time has a positive effect, while the temperature influence is negligible on the inhibitor efficiency. The present terpolymer obeys the Langmuir isotherm, and thermodynamic calculation reveals a chemisorption type on the surface. Density functional calculations showed that the lone pairs of electrons of oxygen in the structure of three monomers are suitable sites to adsorb onto the metal surface. Finally, in the presence of ATP, a decrease in surface roughness and corrosion attacks was demonstrated by atomic force microscopy and optical microscopy examinations, respectively.

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

    Science.gov (United States)

    Casar, G.; Li, X.; Malič, B.; Zhang, Q. M.; Bobnar, V.

    2015-03-01

    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.

  11. Enhanced permittivity and energy density in neat poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) terpolymer films through control of morphology.

    Science.gov (United States)

    Smith, O'Neil L; Kim, Yunsang; Kathaperumal, Mohanalingam; Gadinski, Matthew R; Pan, Ming-Jen; Wang, Qing; Perry, Joseph W

    2014-06-25

    Polymer materials with large dielectric constants are desirable for the development of high energy density capacitors. We show that the dielectric properties of poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) [P(VDF-TrFE-CTFE)] can be improved by the use of processing conditions that favor formation of a highly crystalline morphology of the nonpolar α-phase. Through the use of spin coating, thermal treatment above the melting temperature, and quenching, we were able to attain a highly crystalline, α-phase rich morphology that has a quite large dielectric constant of 77 ± 10 at 1 kHz. The final morphology and phase composition of the terpolymer films depend strongly on the postprocessing thermal treatment and the quality of the solvent. Evaluation of the polarization behavior of the terpolymer films as a function of electric field reveal that the polymer exhibits a relaxor-ferroelectric behavior and has a substantial energy density of 9.7 J/cm(3) at fields of up to approximately 470 V/μm. Under millisecond pulsed charge-discharge measurements a 3-fold increase in energy density (27 J/cm(3)) is obtained at high fields (∼600 V/μm). Our study demonstrates that the processing conditions and morphology of fluorinated terpolymer films are controlling factors for achievement of high dielectric permittivity and energy density that are critical for high performance capacitors. PMID:24873348

  12. 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.

  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. Research on the synthesis and scale inhibition performance of a new terpolymer scale inhibitor.

    Science.gov (United States)

    Bao, Yufei; Li, Meng; Zhang, Yanqing

    2016-01-01

    A new terpolymer named β-CD-MA-SSS was produced using free-radical polymerization of β-cyclodextrin (β-CD), maleic-anhydride (MA) and sodium-styrene-sulfonate (SSS) as monomers, with potassium persulfate (KPS) as initiator. Its performance as a scale inhibitor to prevent deposition of calcium carbonate (CaCO3) has been investigated. Experimental results demonstrated that β-CD-MA-SSS performed excellent scale inhibition and exhibited a high conversion rate under the following conditions: initiator consisting of 6%, molar ratio of reaction monomers SSS:MA = 0.8:1, MA:β-CD = 6:1, reaction temperature of 80 °C, reaction time of 6 h, and dropping time of 40 min when MA was dosed as a substrate, and SSS and KPS were dosed as dropping reactants simultaneously. Use of a Fourier transform infrared spectrometer for this inhibitor showed that the polymerization reaction had taken place with the reaction monomers under the above specified conditions. Scanning electron microscopy indicated that the β-CD-MA-SSS had a strong chelating ability for calcium (Ca(2+)) and a good dispersion ability for calcium carbonate (CaCO3). PMID:27054733

  16. 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; Yoncheva, K. (Krassimira); Mokreva, P. (Pavlina); Konstantinov, S.; J M Irache; 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 ...

  17. 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

  18. Optimization of tyrosine-derived polycarbonate terpolymers for bone regeneration scaffolds

    Science.gov (United States)

    Resurreccion-Magno, Maria Hanshella C.

    Tyrosine-derived polycarbonates (TyrPC) are a versatile class of polymers highly suitable for bone tissue engineering. Among the tyrosine-derived polycarbonates, poly(DTE carbonate) has an FDA masterfile that documents its biocompatibility and non-toxicity and has shown potential utility in orthopedics due to its osteoconductive properties and strength. DTE stands for desaminotyrosyl-tyrosine ethyl ester and is the most commonly used tyrosine-derived monomer. However, in vitro degradation studies showed that poly(DTE carbonate) did not completely resorb even after four years of incubation in phosphate buffered saline. Thus for bone regeneration, which only requires a temporary implant until the bone heals, poly(DTE carbonate) would not be the best choice. The goal of the present research was to optimize a scaffold composition for bone regeneration that is based on desaminotyrosyl-tyrosine alkyl ester (DTR), desaminotyrosyl-tyrosine (DT) and poly(ethylene glycol) (PEG). Five areas of research were presented: (1) synthesis and characterization of a focused library of TyrPC terpolymers; (2) evaluation of the effects of how small changes on the composition affected the mechanism and kinetics of polymer degradation and erosion; (3) fabrication of bioactive three-dimensional porous scaffold constructs for bone regeneration; (4) assessment of osteogenic properties in vitro using pre-osteoblasts; and (5) evaluation of bone regeneration potential, with or without recombinant human bone morphogenetic protein-2 (rhBMP-2), in vivo using a critical sized defect (CSD) rabbit calvaria (cranium) model. Small changes in the composition, such as changing the R group of DTR from ethyl to methyl, varying the mole percentages of DT and PEG, and using a different PEG block length, affected the overall properties of these polymers. Porous scaffolds were prepared by a combination of solvent casting, porogen leaching and phase separation techniques. Calcium phosphate was coated on the

  19. 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%.

  20. Amphiphilic Diblock Terpolymer PMAgala-b-P(MAA-co-MAChol)s with Attached Galactose and Cholesterol Grafts and Their Intracellular pH-Responsive Doxorubicin Delivery.

    Science.gov (United States)

    Wang, Zhao; Luo, Ting; Sheng, Ruilong; Li, Hui; Sun, Jingjing; Cao, Amin

    2016-01-11

    In this work, a series of diblock terpolymer poly(6-O-methacryloyl-D-galactopyranose)-b-poly(methacrylic acid-co-6-cholesteryloxy hexyl methacrylate) amphiphiles bearing attached galactose and cholesterol grafts denoted as the PMAgala-b-P(MAA-co-MAChol)s were designed and prepared, and these terpolymer amphiphiles were further exploited as a platform for intracellular doxorubicin (DOX) delivery. First, employing a sequential RAFT strategy with preliminarily synthesized poly(6-O-methacryloyl-1,2:3,4-di-O-isopropylidene-d-galactopyranose) (PMAIpGP) macro-RAFT initiator and a successive trifluoroacetic acid (TFA)-mediated deprotection, a series of amphiphilic diblock terpolymer PMAgala-b-P(MAA-co-MAChol)s were prepared, and were further characterized by NMR, Fourier transform infrared spectrometer (FTIR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and a dynamic contact angle testing instrument (DCAT). In aqueous media, spontaneous micellization of the synthesized diblock terpolymer amphiphiles were continuously examined by critical micellization concentration assay, dynamic light scattering (DLS), and transmission electron microscopy (TEM), and the efficacies of DOX loading by these copolymer micelles were investigated along with the complexed nanoparticle stability. Furthermore, in vitro DOX release of the drug-loaded terpolymer micelles were studied at 37 °C in buffer under various pH conditions, and cell toxicities of as-synthesized diblock amphiphiles were examined by MTT assay. Finally, with H1299 cells, intracellular DOX delivery and localization by the block amphiphile vectors were investigated by invert fluorescence microscopy. As a result, it was revealed that the random copolymerization of MAA and MAChol comonomers in the second block limited the formation of cholesterol liquid-crystal phase and enhanced DOX loading efficiency and complex nanoparticle stability, that ionic interactions between the DOX and MAA comonomer

  1. ABS 497 ASH Tutorial / Uoptutorial

    OpenAIRE

    Latifa Baka

    2015-01-01

    For more course tutorials visit www.uoptutorial.com   ABS 497 Week 1 Assignment Community Change ABS 497 Week 1 DQ 1 Fabian's Story ABS 497 Week 1 DQ 2 Doug's Story ABS 497 Week 2 DQ 1 Parenting Styles ABS 497 Week 2 DQ 2 Ethnicity and Learning Theory ABS 497 Week 3 DQ 1 Suicide ABS 497 Week 3 DQ 2 Development Theories ABS 497 Week 3 Assignment communication PowerPoint Presentation ABS 497 Week 4 DQ 1 Leadership Theories ABS 497 Week 4 ...

  2. ABS 497 ASH TUTORIAL / Uoptutorial

    OpenAIRE

    Remo

    2015-01-01

    For more course tutorials visit www.uoptutorial.com   ABS 497 Week 1 Assignment Community Change ABS 497 Week 1 DQ 1 Fabian's Story ABS 497 Week 1 DQ 2 Doug's Story ABS 497 Week 2 DQ 1 Parenting Styles ABS 497 Week 2 DQ 2 Ethnicity and Learning Theory ABS 497 Week 3 DQ 1 Suicide ABS 497 Week 3 DQ 2 Development Theories ABS 497 Week 3 Assignment communication PowerPoint Presentation ABS 497 Week 4 DQ 1 Leadership Theories ABS 497 Week 4...

  3. ABS 497 Courses/snaptutorial

    OpenAIRE

    charles

    2015-01-01

    For more classes visit www.snaptutorial.com   ABS 497 Week 1 Assignment Community Change ABS 497 Week 1 DQ 1 Fabian's Story ABS 497 Week 1 DQ 2 Doug's Story ABS 497 Week 2 DQ 1 Parenting Styles ABS 497 Week 2 DQ 2 Ethnicity and Learning Theory ABS 497 Week 3 DQ 1 Suicide ABS 497 Week 3 DQ 2 Development Theories ABS 497 Week 3 Assignment communication PowerPoint Presentation ABS 497 Week 4 DQ 1 Leadership Theories ABS 497 Week 4 DQ ...

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

    OpenAIRE

    Siti Nurul Ain Md Jamil; Rusli Daik; Ishak Ahmad

    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...

  5. 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.

  6. 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

  7. Verdivurdering av SAS AB

    OpenAIRE

    Gangås, Silje Garberg

    2013-01-01

    Formålet med denne mastergradsavhandlingen har vært å beregne den teoretiske verdien på det børsnoterte selskapet SAS AB og på bakgrunn av denne gi en handlingsanbefaling på selskapets aksje. Forskningsspørsmålet for oppgaven er utledet som følger: ”Hva er verdien av SAS AB?” SAS AB er inne i en fundamental omstillingsprosses hvor den nye strategien, 4XNG, ble presentert og påbegynt november 2012. Omstillingsprosessen innebærer blant annet en omfattende omstrukturering i organisasjonen ...

  8. Filled Ethylene-propylene Diene Terpolymer Elastomer as ThermalInsulator for Case-bonded Solid Rocket Motors

    Directory of Open Access Journals (Sweden)

    C. M. Bhuvaneswari

    2008-01-01

    Full Text Available Ethylene-propylene diene terpolymer (EPDM-based insulation system is being globallyused for case-bonded solid rocket motors. A study was undertaken using EPDM as base polymer,blended with hypalon and liquid EPDM and filled with fibrous and non-fibrous fillers. Theseformulations were evaluated as rocket motor insulation system. The basic objective of the studywas to develop an insulation system based on EPDM for case-bonded applications. A series ofrocket motor insulator compositions based on EPDM, filled with particulate and fibrous fillerslike precipitated silica, fumed silica, aramid, and carbon fibres have been studied for mechanical,rheological, thermal, and interface properties. Compositions based on particulate fillers wereoptimised for the filler content. Comparatively, fumed silica was found to be superior as fillerin terms of mechanical and interface properties. Addition of fibrous filler (5 parts improved thepeel strength, and reduced the thermal conductivity and erosion rate. All the compositions wereevaluated for sulphur and peroxide curing. Superior mechanical properties were achieved forsulphur-cured products, whereas peroxide-cured products exhibited an excellent ageing resistance.Rocket motors were insulated with optimised composition and propellant cast, and the motorswere evaluated by conducting static test in end-burning mode.Defence Science Journal, 2008, 58(1, pp.94-102, DOI : http://dx.doi.org/10.14429/dsj.58.1628

  9. 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.

  10. 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).

  11. 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.

  12. 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...

  13. ABS 497 ASH Tutorial/Uoptutorial

    OpenAIRE

    Kathi

    2015-01-01

    ABS 497 Week 1 Assignment Community Change ABS 497 Week 1 DQ 1 Fabian's Story ABS 497 Week 1 DQ 2 Doug's Story ABS 497 Week 2 DQ 1 Parenting Styles ABS 497 Week 2 DQ 2 Ethnicity and Learning Theory ABS 497 Week 3 DQ 1 Suicide ABS 497 Week 3 DQ 2 Development Theories ABS 497 Week 3 Assignment communication PowerPoint Presentation ABS 497 Week 4 DQ 1 Leadership Theories ABS 497 Week 4 DQ 2 Problems of Adolescence ABS 497 Week 5 DQ Macro Social Systems...

  14. The AB Staff Plan

    CERN Document Server

    Boillot, J; Delahaye, J P; Myers, S; CERN. Geneva. AB Department

    2003-01-01

    The present report summarises the staff plan of the newly created Accelerators and Beams (AB) Division following the restructuring of the Accelerator Sector and covering the period 2003 to 2010. It underlines the refocusing of the staff on priority work, especially the LHC Project and is coherent with the recently adopted CERN Long Term Plan (LTP). It compares the requested and available manpower (both staff and industrial support) for each Project, Programme and Activity (PPA) split in work packages and highlights the missing manpower for each category of personnel.

  15. 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.

  16. ABS 497 ASH Tutorial Course/Uoptutorial

    OpenAIRE

    thanu

    2015-01-01

    For More Course Tutorials Visit www.uoptutorial.com   ABS 497 Week 1 Assignment Community Change ABS 497 Week 1 DQ 1 Fabian's Story ABS 497 Week 1 DQ 2 Doug's Story ABS 497 Week 2 DQ 1 Parenting Styles ABS 497 Week 2 DQ 2 Ethnicity and Learning Theory ABS 497 Week 3 DQ 1 Suicide ABS 497 Week 3 DQ 2 Development Theories ABS 497 Week 3 Assignment communication PowerPoint Presentation ABS 497 Week 4 DQ 1 Leadership Theories ABS 497 Week 4 ...

  17. 高胶ABS胶乳凝聚工艺研究%Study on coagulation process of high rubber ABS latex

    Institute of Scientific and Technical Information of China (English)

    韩洪义; 李小军

    2011-01-01

    The influences of coagulant dosage, coagulation temperature and stirring rate on coagulation effect were studied through the analysis of coagulation mechanism of high rubber acrylonitrile-butadiene-styrene terpolymer(ABS) latex. The optimum process conditions were determined based on the practical production situation of the industrial plant as follows: coagulant dosage 35-45 kg/t, coagulation temperature 76 ℃and stirring rate 100 r/min. A suggestion was presented for improving the existing coagulation process.%通过分析高胶丙烯腈-丁二烯-苯乙烯三元共聚物(ABS)的胶乳凝聚机理,研究了凝聚剂用量、凝聚温度和搅拌器转速对凝聚效果的影响.结合装置实际生产情况得出最佳凝聚工艺条件:凝聚剂用量35-45 kg/t,凝聚温度为76℃,搅拌器转速为100 r/min.对现有凝聚工艺提出了改进建议.

  18. 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

  19. 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.

  20. abs417ashcoursesTutorial /uophelp

    OpenAIRE

    smith

    2015-01-01

    For more course tutorials visit www.uophelp.com     ABS 417 Week 1 DQ 1 ( The Power of Many )    ABS 417 Week 1 DQ 2 ( Social Change Model )    ABS 417 Week 2 DQ 1 ( Empowerment, Disempowerment and Social Change )   ABS 417 Week 2 DQ 2 ( Non-Profit vs. For-Profit Organizations )    ABS 417 Week 2 Assignment ( Reflection Paper )    ABS 417 Week 3 DQ 1 ( Social Problems )  &nb...

  1. Opstellen Aaltjes Beheersing Strategie (ABS)

    NARCIS (Netherlands)

    Beers, van T.G.

    2009-01-01

    Dit artikel gaat dieper in op het opstellen van een Aaltjes Beheersing Strategie (ABS): inventarisatie, preventie, vruchtwisseling en aanvullende maatregelen. Per onderdeel worden aandachtspunten genoemd en er worden tips gegeven.

  2. Thermal aging of interfacial polymer chains in ethylene-propylene-diene terpolymer/aluminum hydroxide composites: solid-state NMR study.

    Science.gov (United States)

    Gabrielle, Brice; Lorthioir, Cédric; Lauprêtre, Françoise

    2011-11-01

    The possible influence of micrometric-size filler particles on the thermo-oxidative degradation behavior of the polymer chains at polymer/filler interfaces is still an open question. In this study, a cross-linked ethylene-propylene-diene (EPDM) terpolymer filled by aluminum trihydrate (ATH) particles is investigated using (1)H solid-state NMR. The time evolution of the EPDM network microstructure under thermal aging at 80 °C is monitored as a function of the exposure time and compared to that of an unfilled EPDM network displaying a similar initial structure. While nearly no variations of the topology are observed on the neat EPDM network over 5 days at 80 °C, a significant amount of chain scission phenomena are evidenced in EPDM/ATH. A specific surface effect induced by ATH on the thermodegradative properties of the polymer chains located in their vicinity is thus pointed out. Close to the filler particles, a higher amount of chain scissions are detected, and the characteristic length scale related to these interfacial regions displaying a significant thermo-oxidation process is determined as a function of the aging time.

  3. Increasing the Mechanical Strength of Block Polymer Ion Gels Through the Stepwise Self-Assembly of a Thermoresponsive ABC Triblock Terpolymer

    Science.gov (United States)

    Hall, Cecilia; Zhou, Can; Danielsen, Scott; Lodge, Timothy

    Blends of network-forming block polymers and ionic liquids have remarkable potential for solid electrolytes, as they allow the combination of desirable mechanical and electrical properties. While ABA triblock copolymers have successfully been implemented as the network component of ion gels, these networks contain looped defects, where the endblocks of the polymer loop back into the same spherical core instead of forming a bridge between two cores. We demonstrate that the ABC triblock terpolymer poly(ethylene-alt-propylene)-block-poly(ethylene oxide)-block-poly(N-isopropylacrylamide) (PEP-b-PEO-b-PNIPAm) in the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide forms a thermoreversible gel network with negligible looping defects. PEP-core micelles exist at all temperatures, while cooling causes association of the PNIPAm micelle corona to form a bridging network. Small-angle x-ray scattering and dynamic light scattering were used to characterize the high-temperature micelles. These gels show enhanced mechanical properties and the ability to form gels at lower concentrations than the corresponding thermoresponsive ABA triblock copolymers.

  4. Controlling Solution Self-assembly and Non-Solvent Induced Microphase Separation of Triblock Terpolymers to Generate Nanofiltration Membranes with Chemically-Tailored Pore Walls

    Science.gov (United States)

    Boudouris, Bryan; Mulvenna, Ryan; Weidman, Jacob; Phillip, William

    2014-03-01

    Block polymer-based templates have been utilized in a number of membrane applications; however, there has yet to be a demonstration of a nanoporous block polymer thin film that can achieve high flux and high selectivity simultaneously while also allowing for the facile tuning of the pore wall chemistry. Here, we demonstrate that by synthesizing and controlling the solution self-assembly of a triblock terpolymer, polyisoprene- b-polystyrene- b-poly(N, N-dimethylacrylamide) (PI-PS-PDMA), and precisely inducing non-solvent induced phase separation during the self-assembly process allows for the creation of an asymmetric nanoporous membrane with PDMA-lined pore walls. This PDMA functionality is then converted to any number of side chain functionalities through simple chemistry in the solid state. In this way, we are able to show a highly selectivity membrane that can separate analytes of interest based both on size and chemical composition at a high solution flux. In fact, this high fidelity structure has a very narrow distribution of pore sizes (500 cm2) . This has allowed for the separation of particles with hydrodynamic radii as low as 0.8 nm, which is the smallest separation achieved using a block polymer-based membrane to date.

  5. POSO-MA-SAS 三元共聚物的制备及脱墨应用%Synthesis of terpolymer surfactant POSO-MA-SAS and its deinking performance

    Institute of Scientific and Technical Information of China (English)

    张昌辉; 李强; 李丹; 崔丽萍

    2014-01-01

    The terpolymer anionic surfactant POSO-MA-SAS was synthesized by copolymeri-zation reaction of potassium sorbate (POSO) ,methyl acrylate (MA) and sodium allyl sulfon-ate (SAS) .The better synthesis process and the application to waste paper deinking used washing method was studied ,and terpolymer compounded performance was compared with commercial deinking agent .It was found that the better synthesis condition was determined as follow s :the molar ratio of potassium sorbate (POSO ) to methyl acrylate (M A ) to sodi-um allyl sulfonate (SAS) was 1∶3∶1 at 90 ℃ for 5 h ,dosage of initiator is 6% of monomer mass fraction .The terpolymer has good deinking effect ;the deinking effect was further im-prove when terpolymer compound with AES as the ratio 1∶1 .Compound dosage was 0 .2% , the whiteness of the paper deinked can be increased by 3 .8% ISO compared with commercial-ly available deinking agent and the residual ink concentration was 49 .53 mm2 · m -2 .%以山梨酸钾(POSO)、丙烯酸甲酯(MA)和烯丙基磺酸钠(SAS)为单体通过共聚反应制得POSO-M A-SAS三元共聚物阴离子表面活性剂.研究了最佳合成工艺,考察了共聚物在洗涤法废纸脱墨中的应用,复配后与市售脱墨剂进行了对比.结果表明,当 n(POSO )∶ n (MA)∶ n(SAS)=1∶3∶1,聚合反应温度为90℃,聚合反应时间5 h ,引发剂用量为单体总质量6%时,共聚物具有较好洗涤脱墨效果;共聚物与A ES复配使用时洗涤脱墨效果进一步提高,当m(POSO-MA-SAS)∶ m(AES)=1∶1,用量为0.2%时,脱墨后成纸白度相比市售脱墨剂提高3.8% ISO ,残余油墨量仅为49.53 mm2· m -2.

  6. IA/MA/AMPS 三元共聚物阻垢剂的性能评价%Performance evaluation of IA/MA/AMPS terpolymer scale inhibitor

    Institute of Scientific and Technical Information of China (English)

    张凤华; 刘鹏宇; 李飞

    2016-01-01

    In view of the IA/MA/AMPS terpolymer scale inhibitors.The effect of mass concentration of cal-cium ion,water temperature and pH of medium on the scale inhibition performance for calcium carbonate were investigated.The thermal stability of the copolymer scale inhibitors were analyzed via TG.The com-parison experiments of copolymer scale inhibitor and commercial scale inhibitor were carried on the disper-sion performance of scale inhibitors for ferric oxide.Results show that the ternary copolymer scale inhibitor has good thermal stability.The dispersion performance of scale inhibitors for ferric oxide is superior to com-mercial copolymer scale inhibitors WD-700 and T-225.It is found that copolymer scale inhibitors are suit-able for weak alkaline (pH =7 ~9),high temperature and moderate hardness water system.%针对实验合成的 IA /MA /AMPS 三元共聚物阻垢剂,分别考察了钙离子质量浓度、水样温度、水样 pH 值对共聚物阻垢性能的影响,合成的共聚物与市售阻垢剂分散氧化铁的性能进行了对比实验,并对提纯后的 IA /MA /AMPS 三元共聚物阻垢剂作 TG 分析。结果表明,合成的三元共聚物阻垢剂具有良好的热稳定性,分散氧化铁性能优于市售阻垢剂,适用于弱碱性、高温、中等矿化度的工业循环冷却水。

  7. Poly(methyl methacrylate-acrylonitrile-ethyl acrylate) terpolymer based gel electrolyte for LiNi0.5Mn1.5O4 cathode of high voltage lithium ion battery

    Science.gov (United States)

    Sun, Ping; Liao, Youhao; Xie, Huili; Chen, Tingting; Rao, Mumin; Li, Weishan

    2014-12-01

    A novel gel polymer electrolyte (GPE), based on poly(methyl methacrylate-acrylonitrile-ethyl acrylate) (P(MMA-AN-EA)) terpolymer, is designed to match LiNi0.5Mn1.5O4 cathode of 5 V lithium ion battery. The performances of the synthesized P(MMA-AN-EA) terpolymer and the corresponding membrane and GPE are investigated by scanning electron microscope, energy dispersive spectroscopy, nuclear magnetic resonance spectra, Fourier transform infrared spectra, thermogravimetric analyzer, electrochemical impedance spectroscopy, linear sweep voltammetry, and charge/discharge test. It is found that the pore structure of P(MMA-AN-EA) membrane is affected by the dose of pore forming agent, polyethylene glycol (PEG400). The membrane with 3 wt% PEG400 presents the best pore structure, in which pores are dispersed uniformly and interconnected, and exhibits the largest electrolyte uptake, resulting in the highest ionic conductivity of 3.82 × 10-3 S cm-1 for the corresponding GPE at room temperature. The GPE has improved compatibility with lithium anode and is electrochemically stable up to 5.2 V (vs. Li/Li+). The high voltage LiNi0.5Mn1.5O4 cathode using the resulting GPE exhibits excellent cyclic stability, maintaining 97.9% of its initial discharge capacity after 100 cycles compared to that of 79.7% for the liquid electrolyte at 0.5 C.

  8. Equity valuation : Atlas Copco AB

    OpenAIRE

    Santos, Ricardo Manuel Castro Lopes Alba

    2016-01-01

    This Dissertation presents a literature review of some of the most appraised theories on equity valuation models. A thoughtful analysis is made, presenting the main advantages and restrictions of each model and setting the path for a discussion about improvements to be made on this field of study. A practical implementation follows, proposing a fair value estimation of Atlas Copco AB shares. Atlas Copco is a Swedish-based capital goods company, operating across four differen...

  9. Thermonuclear Reflect AB-Reactor

    CERN Document Server

    Bolonkin, Alexander

    2008-01-01

    The author offers a new kind of thermonuclear reflect reactor. The remarkable feature of this new reactor is a three net AB reflector, which confines the high temperature plasma. The plasma loses part of its energy when it contacts with the net but this loss can be compensated by an additional permanent plasma heating. When the plasma is rarefied (has a small density), the heat flow to the AB reflector is not large and the temperature in the triple reflector net is lower than 2000 - 3000 K. This offered AB-reactor has significantly less power then the currently contemplated power reactors with magnetic or inertial confinement (hundreds-thousands of kW, not millions of kW). But it is enough for many vehicles and ships and particularly valuable for tunnelers, subs and space apparatus, where air to burn chemical fuel is at a premium or simply not available. The author has made a number of innovations in this reactor, researched its theory, developed methods of computation, made a sample computation of typical pr...

  10. AB Levitator and Electricity Storage

    CERN Document Server

    Bolonkin, A

    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 weight ratio of this engine is 0.01 - 0.1 (from thrust). For some types of AB engine (toroidal form) the thrust easily may be changed in any direction without turning of engine. The author computed many projects using different versions of offered AB engine: small device for levitation-flight of a human (including flight from Earth to Outer Space), fly VTOL car (track), big VTOL aircrat, suspended low altitude stationary satellite, powerful Space Shuttle-like booster for travel to the Moon and Mars without spending energ...

  11. 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.

  12. 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.

  13. 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

  14. Microwave Study of Recycled ABS Resins

    Institute of Scientific and Technical Information of China (English)

    A; M; Hasna

    2002-01-01

    This article provides a review of the research unde rt aken in order to determine the suitability of utilizing microwave technology in the production of Recycled ABS Acrylonitrile Butadiene Styrene resin for mouldin gs. The experimental investigation determined the suitability of the existing re cycled ABS material, the mould material used with respect to performance and lon gevity, potential commercial plant and equipment, end mould compression. Introduction Frequency Characterization of ABS The first ...

  15. abs497ashcoursesTutorial /uophelp

    OpenAIRE

    davids

    2015-01-01

    For more course tutorials visit www.uophelp.com       I.        ABS 497 Week 1 Assignment Community Change   II.        ABS 497 Week 1 DQ 1 Fabian's Story III.        ABS 497 Week 1 DQ 2 Doug's Story IV.        ABS 497 Week 2 DQ 1 Parenting Styles   V.      &nb...

  16. 腈纶皂化制备电流变液悬浮粒子的研究%Studies on Saponification of Acrylonitrile Terpolymer for Suspending Particles of Electrorheological Fluids

    Institute of Scientific and Technical Information of China (English)

    吴孟强; 陈艾

    2001-01-01

    In order to prepare suspending particles for electrorheological fluids, hetergeneous hydrolysis of acrylonitrile terpolymer is conducted in presence of saponifying agent(sodium hydroxide) in this paper. The effects of the saponification conditions such as the amount of added sodium hydroxide, time duration and temperature on the degree of saponification are studied in detail. Meanwhile, the conversion of nitrile groups is discussed with the result that the saponification of nitrile groups of the terpolymer initially yields amide groups, then slows down to carboxylic groups. The research sets a way for the preparation of dispersing particles of water-free electrorheological fluids tentatively used for controlling light transmittance.%为了制备无水电流变液用悬浮粒子,研究了腈纶在碱性条件下的多相水解。详细考察了皂化试剂氢氧化钾的用量,皂化时间和温度等皂化条件对皂化程度的影响; 讨论了氰基转化过程。研究结果表明,在皂化初期,腈纶分子链上的氰基转化为酰胺基,然后缓慢转化为羧基。给出了一条制备无水电流变液用悬浮粒子的方法,并初步考察了该类电流变液的控光特性。

  17. ABS test equipment design%ABS 测试设备设计

    Institute of Scientific and Technical Information of China (English)

    王宇鹏

    2013-01-01

      This article simply introduces the structure and operating principle of ABS. and a new equipment for ABS signal testing is designed and put into use.%  简要介绍了 ABS 的组成及其工作原理,并结合自身情况,设计了测试 ABS 信号的设备,并投入使用。

  18. Ab-Initio Molecular Dynamics

    CERN Document Server

    Kühne, Thomas D

    2012-01-01

    Computer simulations and molecular dynamics in particular, is a very powerful method to provide detailed and essentially exact informations of classical many-body problems. With the advent of \\textit{ab-initio} molecular dynamics, where the forces are computed on-the-fly by accurate electronic structure calculations, the scope of either method has been greatly extended. This new approach, which unifies Newton's and Schr\\"odinger's equations, allows for complex simulations without relying on any adjustable parameter. This review is intended to outline the basic principles as well as a survey of the field. Beginning with the derivation of Born-Oppenheimer molecular dynamics, the Car-Parrinello method as well as novel hybrid scheme that unifies best of either approach are discussed. The predictive power is demonstrated by a series of applications ranging from insulators to semiconductors and even metals in condensed phases.

  19. Ultrasound Biomicroscopy Comparison of Ab Interno and Ab Externo Intraocular Lens Scleral Fixation.

    Science.gov (United States)

    Horiguchi, Lie; Garcia, Patricia Novita; Malavazzi, Gustavo Ricci; Allemann, Norma; Gomes, Rachel L R

    2016-01-01

    Purpose. To compare ab interno and ab externo scleral fixation of posterior chamber intraocular lenses (PCIOL) using ultrasound biomicroscopy (UBM). Methods. Randomized patients underwent ab externo or ab interno scleral fixation of a PCIOL. Ultrasound biomicroscopy was performed 3 to 6 months postoperatively, to determine PCIOL centration, IOL distance to the iris at 12, 3, 6, and 9 hours, and haptics placement in relation to the ciliary sulcus. Results. Fifteen patients were enrolled in the study. The ab externo technique was used in 7 eyes (46.6%) and the ab interno in 8 eyes (53.3%). In the ab externo technique, 14 haptics were located: 4 (28.57%) in the ciliary sulcus; 2 (14.28%) anterior to the sulcus; and 8 (57.14%) posterior to the sulcus, 6 in the ciliary body and 2 posterior to the ciliary body. In the ab interno group, 4 haptics (25.0%) were in the ciliary sulcus, 2 (12.50%) anterior to the sulcus, and 10 (75.0%) posterior to the sulcus, 4 in the ciliary body and 6 posterior to the ciliary body. Conclusions. Ab externo and ab interno scleral fixation techniques presented similar results in haptic placement. Ab externo technique presented higher vertical tilt when compared to the ab interno.

  20. Ultrasound Biomicroscopy Comparison of Ab Interno and Ab Externo Intraocular Lens Scleral Fixation

    Directory of Open Access Journals (Sweden)

    Lie Horiguchi

    2016-01-01

    Full Text Available Purpose. To compare ab interno and ab externo scleral fixation of posterior chamber intraocular lenses (PCIOL using ultrasound biomicroscopy (UBM. Methods. Randomized patients underwent ab externo or ab interno scleral fixation of a PCIOL. Ultrasound biomicroscopy was performed 3 to 6 months postoperatively, to determine PCIOL centration, IOL distance to the iris at 12, 3, 6, and 9 hours, and haptics placement in relation to the ciliary sulcus. Results. Fifteen patients were enrolled in the study. The ab externo technique was used in 7 eyes (46.6% and the ab interno in 8 eyes (53.3%. In the ab externo technique, 14 haptics were located: 4 (28.57% in the ciliary sulcus; 2 (14.28% anterior to the sulcus; and 8 (57.14% posterior to the sulcus, 6 in the ciliary body and 2 posterior to the ciliary body. In the ab interno group, 4 haptics (25.0% were in the ciliary sulcus, 2 (12.50% anterior to the sulcus, and 10 (75.0% posterior to the sulcus, 4 in the ciliary body and 6 posterior to the ciliary body. Conclusions. Ab externo and ab interno scleral fixation techniques presented similar results in haptic placement. Ab externo technique presented higher vertical tilt when compared to the ab interno.

  1. Ultrasound Biomicroscopy Comparison of Ab Interno and Ab Externo Intraocular Lens Scleral Fixation

    Science.gov (United States)

    Horiguchi, Lie; Garcia, Patricia Novita; Malavazzi, Gustavo Ricci; Allemann, Norma

    2016-01-01

    Purpose. To compare ab interno and ab externo scleral fixation of posterior chamber intraocular lenses (PCIOL) using ultrasound biomicroscopy (UBM). Methods. Randomized patients underwent ab externo or ab interno scleral fixation of a PCIOL. Ultrasound biomicroscopy was performed 3 to 6 months postoperatively, to determine PCIOL centration, IOL distance to the iris at 12, 3, 6, and 9 hours, and haptics placement in relation to the ciliary sulcus. Results. Fifteen patients were enrolled in the study. The ab externo technique was used in 7 eyes (46.6%) and the ab interno in 8 eyes (53.3%). In the ab externo technique, 14 haptics were located: 4 (28.57%) in the ciliary sulcus; 2 (14.28%) anterior to the sulcus; and 8 (57.14%) posterior to the sulcus, 6 in the ciliary body and 2 posterior to the ciliary body. In the ab interno group, 4 haptics (25.0%) were in the ciliary sulcus, 2 (12.50%) anterior to the sulcus, and 10 (75.0%) posterior to the sulcus, 4 in the ciliary body and 6 posterior to the ciliary body. Conclusions. Ab externo and ab interno scleral fixation techniques presented similar results in haptic placement. Ab externo technique presented higher vertical tilt when compared to the ab interno. PMID:27293878

  2. 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

  3. Multiwavelength Observations of AB Doradus

    CERN Document Server

    Slee, O B; Johnston-Hollitt, M; Budding, E

    2014-01-01

    We have observed the bright, magnetically active multiple star AB Doradus in a multiwavelength campaign centring around two large facility allocations in November 2006 and January, 2007. Our observations have covered at least three large flares. These flares were observed to produce significant hardening of the X-ray spectra during their very initial stages. We monitored flare-related effects using the Suzaku X-ray satellite and the Australia Telescope Compact Array at 3.6 and 6 cm. Observations at 11 and 21 cm were also included, but they were compromised by interference. From our multiwavelength coverage we find that the observed effects can be mainly associated with a large active region near longitude zero. The second major X-ray and microwave flare of Jan 8, 2007 was observed with a favourable geometry that allowed its initial high-energy impulsive phase to be observed in the higher frequency range of Suzaku's XIS detectors. The fractional circular polarisation was measured for the complete runs, for 25 ...

  4. GINGA Observations of AB Doradus

    Science.gov (United States)

    Vilhu, O.; Tsuru, T.; Collier Cameron, A.

    We report GINGA observations of the pre main sequence star AB Doradus (HD 36705), performed during 8 - 12 January, 1990. Some rotational modulation might be present. four X-ray flares were detected. Three of these events were similar to the EINSTEIN HRI-flare (Vilhu and Linsky, 1987), with decay times around 25 min. The last flare had long rise and decay times (100 min), resembling the EXOSAT flares observed by Collier Cameron et.al. (1988). The mean flare spectrum can be fitted by a thermal bremstrahlung with temperature 5.0 keV, or by a power-law model with photon index 2.2. The 3 upper limit of the Iron line equivalent width in the flare spectrum is 1 keV, weaker than predicted by thermal models. This Iron line anomaly was first discussed in the case of UX Ari by Tsuru et. al. (1989). However, normal equivalent widths can be derived from several EXOSAT spectra of active cool stars (Pallavicini and Tagliaferri, 1990). We discuss the possibility that the continuum from non-thermal electrons (producing also the microwave emission) could occasionally lower the apparent equivalent width. The mechanism works for reasonably low magnetic field strengths and electon power-law indexes. However, a large population of non-thermal electrons is needed (comparable to the thermal one). Stronger magnetic fields could explain the radio emission with less electrons, but then the non-thermal X-ray continuum remains small.

  5. Collective rotation from ab initio theory

    CERN Document Server

    Caprio, M A; 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 7-9Be 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.

  6. 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

  7. Main: DREDR1ATRD29AB [PLACE

    Lifescience Database Archive (English)

    Full Text Available DREDR1ATRD29AB S000152 23-June-2006 (last modified) kehi Related to responsiveness ...dependent in the ABA-responsive expression of the rd29A in Arabidopsis; DRE; drought; water stress; oxidativ

  8. Reference: DREDR1ATRD29AB [PLACE

    Lifescience Database Archive (English)

    Full Text Available ization and expression of two Arabidopsis DREB2 genes encoding DRE-binding proteins...DREDR1ATRD29AB Nakashima K, Shinwari ZK, Sakuma Y, Seki M, Miura S, Shinozaki K, Yamaguchi-Shinozaki K Organ

  9. Tumor estromal gastrointestinal: estudo de oito casos

    OpenAIRE

    Amico Enio Campos; Coimbra Cesar Wilson Bastos; Bugalho Luiz Antônio; Nai Gisele Alborghetti; Matos Ricardo Marcondes; Machado Cibele Chuery; Silva Fabrício Colacino

    2006-01-01

    OBJETIVO: O diagnóstico e tratamento dos tumores estromais gastrointestinais (TEGI) têm evoluído a partir de estudos recentes de genética e biologia molecular. Tais avanços têm refletido em melhor sobrevivência dos doentes. MÉTODOS: Foi realizado estudo retrospectivo no período de novembro/1998 a julho/2004, em instituição universitária e em clínica privada dos autores, que identificou portadores de TEGI a partir de positividade para c-kit (CD 117), ao exame imunoistoquímico. RESULTADOS: Dos ...

  10. Do buzz ao marketing viral : um estudo

    OpenAIRE

    Viveiros, Nuno Filipe Carvalho

    2015-01-01

    Dissertação de Mestrado em Gestão de Empresas/MBA. Com o crescente ênfase do marketing viral e das redes sociais na divulgação de produtos, serviços e marcas, o seu estudo torna-se pertinente para o desenvolvimento de campanhas mais eficazes e eficientes. Esta tese apresenta um estudo centralizado sobre o impacto que um país tem na criação de buzz de modo a tornar as campanhas de marketing, virais. Estudando e analisando três países (dois desenvolvidos e um em desenvolvimento), com o objet...

  11. 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

  12. MELCOR 1.8.2 assessment: Aerosol experiments ABCOVE AB5, AB6, AB7, and LACE LA2

    Energy Technology Data Exchange (ETDEWEB)

    Souto, F.J.; Haskin, F.E. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering; Kmetyk, L.N. [Sandia National Labs., Albuquerque, NM (United States)

    1994-10-01

    The MELCOR computer code has been used to model four of the large-scale aerosol behavior experiments conducted in the Containment System Test Facility (CSTF) vessel. Tests AB5, AB6 and AB7 of the ABCOVE program simulate the dry aerosol conditions during a hypothetical severe accident in an LMFBR. Test LA2 of the LACE program simulates aerosol behavior in a condensing steam environment during a postulated severe accident in an LWR with failure to isolate the containment. The comparison of code results to experimental data show that MELCOR is able to correctly predict most of the thermal-hydraulic results in the four tests. MELCOR predicts reasonably well the dry aerosol behavior of the ABCOVE tests, but significant disagreements are found in the aerosol behavior modelling for the LA2 experiment. These results tend to support some of the concerns about the MELCOR modelling of steam condensation onto aerosols expressed in previous works. During these analyses, a limitation in the MELCOR input was detected for the specification of the aerosol parameters for more than one component. A Latin Hypercube Sampling (LHS) sensitivity study of the aerosol dynamic constants is presented for test AB6. The study shows the importance of the aerosol shape factors in the aerosol deposition behavior, and reveals that MELCOR input/output processing is highly labor intensive for uncertainty and sensitivity analyses based on LHS.

  13. 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)

  14. Ab interno trabeculectomy: A comprehensive review

    Directory of Open Access Journals (Sweden)

    Ting Ting Liu

    2013-07-01

    Full Text Available PURPOSE To summarize the original literature on ab interno trabeculectomy with the Trabectome system and to review its efficacy and safety in the treatment of glaucoma. METHOD A literature search in PubMed was performed on ab interno trabeculectomy with the Trabectome system, and clinical relevant information was reviewed and summarized. RESULTS Ab interno trabeculectomy with the Trabectome system on average lowered intraocular pressure (IOP to the mid-teens, and decreased the number of required glaucoma medications. Greater preoperative IOP correlated to a greater percent reduction in IOP. The success rates varied among studies, and the definition of success differed by authors. Intraoperative blood reflux was found in nearly all cases. Incidences of early hypotony and IOP spikes were low. No cases of endophthalmitis, wound leak, aqueous misdirection, choroidal hemorrhage or effusions, and irreversible visual acuity decrease (≥2 Snellen lines have been reported. Available studies had a significant amount of data overlap. Only limited data on long-term results was available. There was no randomized controlled trial to date. CONCLUSIONS Ab interno trabeculectomy with the Trabectome system is an effective and safe surgical approach for patients with various types of open angle glaucoma. On average, the procedure at least in the short term lowers IOP to the mid teens regardless of preoperative IOP with or without the aid of topical medications.

  15. Reference: DREDR1ATRD29AB [PLACE

    Lifescience Database Archive (English)

    Full Text Available DREDR1ATRD29AB Narusaka Y, Nakashima K, Shinwari ZK, Sakuma Y, Furihata T, Abe H, N... ABA-dependent expression of Arabidopsis rd29A gene in response to dehydration and high-salinity stresses. Plant J. 34: 137-148 (2003) PubMed: 12694590; ...

  16. KINETIC ANALYSIS OF CO-CONDENSATION POLYMERIZATION OF AB2 AND AB MONOMERS

    Institute of Scientific and Technical Information of China (English)

    Min-qiang Yu; Zhi-ping Zhou; De-yue Yan

    2004-01-01

    This work deals with the kinetics of co-condensation polymerization of AB2 and AB monomers, giving expressions of the two-dimensional molecular weight distribution function and the number/weight average molecular weights of the resulting copolymers. The two-dimensional molecular weight distribution depends on two indices, n and l, which are the respective numbers of AB2 and AB units in a copolymer species. The evolution of the two-dimensional weight and z distributions during the co-condensation polymerization has been evaluated systematically. Finally, the two-dimensional distribution was transformed into a one-dimensional molecular weight distribution with only one variable (the molecular weight of the products instead of the degree of polymerization). The calculated results show that the highly branched copolymer has a very broad molecular weight distribution when the co-condensation polymerization approaches completion.

  17. On the Strain Rate Sensitivity of Abs and Abs Plus Fused Deposition Modeling Parts

    Science.gov (United States)

    Vairis, A.; Petousis, M.; Vidakis, N.; Savvakis, K.

    2016-06-01

    In this work the effect of strain rate on the tensile strength of fused deposition modeling parts built with Acrylonitrile-butadiene-styrene (ABS) and ABS plus material is presented. ASTM D638-02a specimens were built with ABS and ABS plus and they were tested on a Schenck Trebel Co. tensile test machine at three different test speeds, equal, lower, and higher to the test speed required by the ASTM D638-02a standard. The experimental tensile strength results were compared and evaluated. The fracture surfaces of selected specimens were examined with a scanning electron microscope, to determine failure mode of the filament strands. It was found that, as the test speed increases, specimens develop higher tensile strength and have higher elastic modulus. Specimens tested in the highest speed of the experiment had on average about 10% higher elastic modulus and developed on average about 11% higher tensile strength.

  18. Leaching behaviour of the Swedish KBS-glasses ABS 39 and ABS 41

    International Nuclear Information System (INIS)

    The planned Swedish KBS glass corrosion investigation program comprises experiments with inactive glasses containing simulated waste, prolonged in-situ tests, the characterization of corrosion products, immiscibility studies, and corrosion experiments with hot glass. This presentation gives a short description of the entire program. It focuses thereafter on some recent leaching results with the inactive KBS glass qualities ABS 39 and ABS 41, which were leached in a manner similar to the PNL MCC-1 test procedure. 5 figures, 9 tables

  19. Thermomechanical properties of ABS/PA AND ABS/PC blends

    OpenAIRE

    GUINAULT, Alain; Sollogoub, Cyrille

    2009-01-01

    International audience The significant increase of Waste Electric and Electronic Equipment (WEEE) has led to an important research in upgrading recycled engineering plastics by means of a blending technique. Classical twin-screw extrusion is compared to a new blending technique, where two polymers are combined together and then flow in several static mixers. This technique allows to obtain different morphologies of compatibilized ABS/PA or ABS/PC blends and the aim of this work is to evalu...

  20. 高耐热阻燃ABS材料制备及性能研究%Preparation and Properties of High Heat Resistant and Flame Retardant ABS

    Institute of Scientific and Technical Information of China (English)

    汪炉林; 焦蒨; 王林; 郑一泉; 麦堪成

    2013-01-01

    With acrylonitrile-butadiene-styrene(ABS) as substrate resins,by adding styrene-N-phenylmaleimide-maleic anhydride terpolymer (AS-MS-NB) as heat retardancy,high heat resistant ABS masterbatch was prepared with different content of heat retardancy at 240-270 ℃ in a twin-screw extruder. Meanwhile,by adding 1,2-bis(pentabromophenyl)ethane(DBDPE) to the masterbatch,high heat resistant and flame retardant ABS was fabricated by twin-screw extruder at 180-210 ℃. The results show that,the fabricated high heat resistant and flame retardant ABS material both features high heat resistance and flame retardancy, at the same time, the heat resistance and its content have a positive correlation by this two-step method. Meanwhile, with the DBDPE, the masterbatch heat distortion temperature does not decrease remarkably,bending strength,tensile strength and impact strength decrease slightly,but fluidity improves obviously. The fabricated high heat resistant and flame retardant ABS can be widely applied to the motor,blower,power box,microwave ovens,rice cookers,connectors and so on.%以丙烯腈-丁二烯-苯乙烯塑料(ABS)为基体,以苯乙烯-N-苯基马来酰亚胺-马来酸酐三元共聚物(AS-MS-NB)为耐热剂,在双螺杆挤出机中,于240~270℃制备出不同耐热剂含量的高耐热ABS母粒。以此母粒和十溴二苯乙烷(DBDPE)阻燃体系共混,于180~210℃通过双螺杆挤出机制备出高耐热阻燃ABS。结果表明,通过这种两步法制备的高耐热阻燃ABS材料兼具高耐热和阻燃特性,并且耐热剂含量和其制备的阻燃ABS材料的耐热性具有正相关性。同时加入DBDPE未使高耐热阻燃ABS的热变形温度明显降低,弯曲强度、拉伸强度及冲击强度稍有下降,而流动性明显改善,高耐热阻燃ABS可广泛应用于电机、吹风机、电源盒、微波炉、电饭煲、插排等领域。

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

    Science.gov (United States)

    ... of GM2-gangliosidosis, AB variant: Genetic Testing Registry: Tay-Sachs disease, variant AB These resources from MedlinePlus offer ... AB variant Activator Deficiency/GM2 Gangliosidosis Activator-deficient Tay-Sachs disease GM2 Activator Deficiency Disease GM2 gangliosidosis, type ...

  2. Investigation of high level of AsAb, EmAb in fertility female serum infected by chlamydia trachomatis

    International Nuclear Information System (INIS)

    Objective: To investigate the mechanism of chlamydia trachomatis. AsAb, EmAb in female fertility. Methods: LPS antigen of chlamydia in reproduction tract of fertility female was detected by monoclonal antibody and immunology chromatography; the content of AsAb, EmAb in serum of fertility female was detected by ELISA. Results: Infections rate of chlamydia trachomatis in fertility female was higher than that in the control AsAb, EmAb in serum of the fertility patients who were infected with chlamydia trachomatis showed a significant difference from that in the control group. Conclusion: The level of AsAb, EmAb increases in patients who have been infected with chlamydia trachomatis and these cytokines is involved in the course of female fertility

  3. Ab initio mass tensor molecular dynamics

    OpenAIRE

    Tsuchida, Eiji

    2010-01-01

    Mass tensor molecular dynamics was first introduced by Bennett [J. Comput. Phys. 19, 267 (1975)] for efficient sampling of phase space through the use of generalized atomic masses. Here, we show how to apply this method to ab initio molecular dynamics simulations with minimal computational overhead. Test calculations on liquid water show a threefold reduction in computational effort without making the fixed geometry approximation. We also present a simple recipe for estimating the optimal ato...

  4. Reciprocity Theorems for Ab Initio Force Calculations

    CERN Document Server

    Wei, C; Mele, E J; Rappe, A M; Lewis, Steven P.; Rappe, Andrew M.

    1996-01-01

    We present a method for calculating ab initio interatomic forces which scales quadratically with the size of the system and provides a physically transparent representation of the force in terms of the spatial variation of the electronic charge density. The method is based on a reciprocity theorem for evaluating an effective potential acting on a charged ion in the core of each atom. We illustrate the method with calculations for diatomic molecules.

  5. 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

  6. Highly scalable Ab initio genomic motif identification

    KAUST Repository

    Marchand, Benoît

    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.

  7. ESTUDO SOBRE O IMPACTO DOS PROCESSADORES HOSPEDEIROS

    Directory of Open Access Journals (Sweden)

    Alba S. B. Lopes

    2008-05-01

    Full Text Available Arquiteturas reconfiguráveis são dispositivos de hardware capazes de modificar sua estrutura de hardware de acordo com a aplicação a ser executada. Tais dispositivos surgiram como uma alternativa às soluções de hardware tradicionais na tentativa de equilibrar flexibilidade e desempenho. Uma das principais formas de utilização de arquiteturas reconfiguráveis corresponde a um bloco reconfigurável anexado a um processador hospedeiro. Esse processador é responsável por executar diversas tarefas críticas, incluindo o particionamento hardware/software e indicar o momento do bloco reconfigurável executar. Apesar de existirem diversas propostas de arquiteturas reconfiguráveis na literatura, pouco se estudou sobre o impacto do processador hospedeiro na arquitetura. Nesse contexto, esse artigo apresenta um estudo sobre o impacto do processador hospedeiro no desempenho da arquitetura reconfigurável híbrida. Como estudo de caso foi realizada uma avaliação sobre o uso dos processadores SPARC V8 da Sun Microsystems e Nios II da Altera como processadores hospedeiros da arquitetura reconfigurável híbrida RoSA. O objetivo deste estudo é realizar a comparação entre o desempenho desses processadores e identificar qual deles é o mais adequado para anexar a arquitetura em questão. Os resultados mostraram que foi possível alcançar até 47% de ganho de desempenho com o uso do processador Nios II em comparação ao SPARC V8, indicando o primeiro como mais adequado para a arquitetura RoSA. PALAVRAS-CHAVE: arquiteturas reconfiguráveis, processador hospedeiro, desempenho.

  8. Estudo retrospectivo de latrodectismo na Bahia, Brasil

    OpenAIRE

    Rejâne Maria Lira-da-Silva; Graciela Brige Matos; Roney Orismar Sampaio; Tania Brazil Nunes

    1995-01-01

    O trabalho apresenta um estudo retrospectivo de setenta e sete casos de latrodectismo no Estado da Bahia, Brasil, de agosto de 1980 a julho de 1990. Os dados foram levantados nos livros de registro e arquivo de fichas do CIAVE. O agente etiológico em 28% dos acidentes aracnídeos foi a espécie L. curacaviensis e a maior incidência foi registrada no meio urbano (57%), em indivíduos do sexo masculino (70%) e faixa etária de 10 a 29 anos (58%). Os principais sinais locais foram dor (56%), pápula ...

  9. Estudo comparativo de sistemas em aquecimento

    OpenAIRE

    Castro, Inês Marques Costa Borges de

    2013-01-01

    O presente estudo pretende avaliar o desempenho energético e rentabilidade do uso de equipamento de climatização para o aquecimento ambiente de uma casa sénior, através de sistemas tradicionais de produção de água aquecida, como a caldeira e a tradicional bomba de calor, e um sistema apoiado num equipamento de produção solar térmico. Perante uma determinada arquitectura, foram calculados os caudais de ar novo, de forma a garantir a qualidade do ar interior, cumprindo os requisitos da actua...

  10. 汽车ABS/ASR/ACC集成化系统%Integrated ABS/ASR/ACC System for the Car

    Institute of Scientific and Technical Information of China (English)

    刘昭度; 卢江; 时开斌; 安巍

    2001-01-01

    叙述了ACC系统和ABS/ASR系统在改善汽车高速行驶主动安全性方面的功用,阐述了ACC系统是ABS/ASR系统功能的延伸、逻辑的发展及它们之间的内在联系,指出了在ABS/ASR的基础上只需增加测距装置和添加巡航控制子程序,就可方便地实现ABS/ASR/ACC集成化系统,并给出了集成化系统的控制框图和控制方法,论述了ABS/ASR/ACC集成化系统比孤立的ABS/ASR和ACC系统的优越性.%The individual functions of ACC and ABS/ASR are described in the improvements of active safety while the road vehicles travel at a high speed. Being a logic extension of and many inherent connections with ABS/BSR, ACC is easily integrated with ABS/ASR to form an integrated system by adding the headway distance*$-detecting device to the existing ABS/ASR system and expanding the ABS/ASR software. The algorithm flowcharts and control methods of the ABS/ASR/ACC are given. The advantages of the ABS/ASR/ACC system compared with those using the stand alone systems ABS, ASR and ACC are mentioned in details.

  11. Ab Initio Molecular Dynamics: A Virtual Laboratory

    OpenAIRE

    Hobbi Mobarhan, Milad

    2014-01-01

    In this thesis, we perform ab initio molecular dynamics (MD) simulations at the Hartree-Fock level, where the forces are computed on-the-fly using the Born-Oppenheimer approximation. The theory behind the Hartree-Fock method is discussed in detail and an implementation of this method based on Gaussian basis functions is explained. We also demonstrate how to calculate the analytic energy derivatives needed for obtaining the forces acting on the nuclei. Hartree-Fock calculations on the ground s...

  12. Asiakassuhdehallinnan kehityssuunnitelma : Case: Oy Combi Cool Ab

    OpenAIRE

    Puikkonen, Touko

    2011-01-01

    Tässä insinöörityössä tutustuttiin Oy Combi Cool Ab:n asiakassuhdehallintaan ja siinä havaittuihin puutteisiin ja kehitystarpeisiin. Työn tarkoituksena oli luoda yritykselle ajan tasalla oleva asiakasrekisteri ja sen pohjalta kehittää asiakassuhdehallintaa etenkin myynnin, oston ja johdon henkilöstön tarpeita ajatellen muovaamalla siitä henkilöstön myynti- ja asiakaspalvelutyöskentelyä tehostava toimiva kokonaisuus. Combi Cool on vuonna 1985 perustettu kylmäalan tukkuliike, joka on vajaan 30 ...

  13. Ab Initio Study on Hypothetical Silver Nitride

    Institute of Scientific and Technical Information of China (English)

    DELIGOZ Engin; COLAKOGLU Kemal; CIFTCI Yasemin Oztekin

    2008-01-01

    We perform the ab initio calculations based on norm-conserving pseudopotentials and density functional theory to investigate the structural, elastic, and thermodynamical properties for silver nitride (AgN) compound that is a member of the 4d transition metal group and has not been synthesized yet. The obtained results are compared with the other available theoretical data, and the agreement is, generally, quite good. We also present the pressure-dependent behaviour of some mechanical and thermodynamical properties for the same compounds.

  14. Testing Distributed ABS System with Fault Injection

    Science.gov (United States)

    Trawczyński, Dawid; Sosnowski, Janusz; Gawkowski, Piotr

    The paper deals with the problem of adapting software implemented fault injection technique (SWIFI) to evaluate dependability of reactive microcontroller systems. We present an original methodology of disturbing controller operation and analyzing fault effects taking into account reactions of the controlled object and the impact of the system environment. Faults can be injected randomly (in space and time) or targeted at the most sensitive elements of the controller to check it at high stresses. This approach allows identifying rarely encountered problems, usually missed in classical approaches. The developed methodology has been used successfully to verify dependability of ABS system. Experimental results are commented in the paper.

  15. Quantum phases of AB 2 fermionic chains

    Science.gov (United States)

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

    2016-02-01

    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 2O5H2)4X] · 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.

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

    International Nuclear Information System (INIS)

    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

  17. Estudo do teor de alicina em alho

    OpenAIRE

    Mendes, Patrícia Alexandra Pinto

    2008-01-01

    A alicina (dialil-tiosulfinato) é o componente biológico mais activo no alho com inúmeras aplicações a nível da saúde, já conhecida desde décadas. Existem actualmente diversos métodos publicados para a determinação do teor de alicina no alho por HPLC e espectrofotometria. No entanto, os resultados mostram discordância no teor de alicina medido pelos vários métodos. Este estudo tem por objectivo a determinação do teor de alicina por métodos de HPLC e espectrofotometria; e com...

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

    International Nuclear Information System (INIS)

    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.)

  19. Bacillus thuringiensis Cry34Ab1/Cry35Ab1 interactions with western corn rootworm midgut membrane binding sites.

    Directory of Open Access Journals (Sweden)

    Huarong Li

    Full Text Available BACKGROUND: Bacillus thuringiensis (Bt Cry34Ab1/Cry35Ab1 are binary insecticidal proteins that are co-expressed in transgenic corn hybrids for control of western corn rootworm, Diabrotica virgifera virgifera LeConte. Bt crystal (Cry proteins with limited potential for field-relevant cross-resistance are used in combination, along with non-transgenic corn refuges, as a strategy to delay development of resistant rootworm populations. Differences in insect midgut membrane binding site interactions are one line of evidence that Bt protein mechanisms of action differ and that the probability of receptor-mediated cross-resistance is low. METHODOLOGY/PRINCIPAL FINDINGS: Binding site interactions were investigated between Cry34Ab1/Cry35Ab1 and coleopteran active insecticidal proteins Cry3Aa, Cry6Aa, and Cry8Ba on western corn rootworm midgut brush border membrane vesicles (BBMV. Competitive binding of radio-labeled proteins to western corn rootworm BBMV was used as a measure of shared binding sites. Our work shows that (125I-Cry35Ab1 binds to rootworm BBMV, Cry34Ab1 enhances (125I-Cry35Ab1 specific binding, and that (125I-Cry35Ab1 with or without unlabeled Cry34Ab1 does not share binding sites with Cry3Aa, Cry6Aa, or Cry8Ba. Two primary lines of evidence presented here support the lack of shared binding sites between Cry34Ab1/Cry35Ab1 and the aforementioned proteins: 1 No competitive binding to rootworm BBMV was observed for competitor proteins when used in excess with (125I-Cry35Ab1 alone or combined with unlabeled Cry34Ab1, and 2 No competitive binding to rootworm BBMV was observed for unlabeled Cry34Ab1 and Cry35Ab1, or a combination of the two, when used in excess with (125I-Cry3Aa, or (125I-Cry8Ba. CONCLUSIONS/SIGNIFICANCE: Combining two or more insecticidal proteins active against the same target pest is one tactic to delay the onset of resistance to either protein. We conclude that Cry34Ab1/Cry35Ab1 are compatible with Cry3Aa, Cry6Aa, or Cry8Ba

  20. Characterization of solution properties of poly(MMA-co-MBA-co-MA-POSS) terpolymer by inverse gas chromatograph%Poly(MMA-co-MBA-co-MA-POSS)三元共聚物溶液性质的反气相色谱表征

    Institute of Scientific and Technical Information of China (English)

    秦如浩; 郭胜男; 周晓慧; 柴仕淦; 张金枝; 邹其超

    2012-01-01

    The solution properties of poly (methyl methacrylate-co-n-butyl methacrylate-co-cy-clopentyl methacryloxy propyl-polyhedral oligomeric silsesquioxane) terpolymer, poly(MMA-co-MBA-co-MA-POSS) in short, were investigated by inverse gas chromatography (IGC) using 20 different kinds of solvents as the probes. The interactions between POSS-containing polymers and solvents and the solubility of the polymers in these solvents were analyzed by taking into account some thermodynamic parameters. It has been found that methyl acetate, ethyl acetate, aromatic hydrocarbons, dichoromethane, and chloroform are good solvents; n-propyl acetate, n-butyl acetate, n-pentyl acetate, and carbon tetrachloride are moderate solvents, while alkanes and alcohols are poor solvents for all POSS-containing polymers within the experimental temperature range. The solubility of the terpolymer in the probe solvents rises with increasing content of POSS therein, but incorporation of POSS has no obvious influence on the solubility parameter of the terpolymer.%以20种溶剂作为探针分子,采用反气相色谱技术表征了甲基丙烯酸甲酯甲基丙烯酸丁酯-甲基丙烯酰氧丙基七环戊基倍半硅氧烷三元共聚物[poly( MMA-co-MBA-co-MA-POSS)]的一系列物理化学性质,并分析了溶剂探针分子与共聚物分子间的相互作用以及共聚物在溶剂中的溶解性.结果表明:在实验温度范围内(343~393 K),乙酸甲酯、乙酸乙酯、芳烃、二氯甲烷、三氯甲烷是良溶剂,乙酸丙酯、乙酸丁酯、乙酸戊酯、四氯化碳是中等溶剂,烷烃类和醇类是劣溶剂;随着共聚物中POSS含量的增大,溶剂探针分子溶解聚合物的能力增强,但引入POSS对共聚物的溶度参数无明显影响.

  1. 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.

  2. Ab initio alpha-alpha scattering

    CERN Document Server

    Elhatisari, Serdar; Rupak, Gautam; Epelbaum, Evgeny; Krebs, Hermann; Lähde, Timo A; Luu, Thomas; Meißner, Ulf-G

    2015-01-01

    Processes involving alpha particles and alpha-like nuclei comprise a major part of stellar nucleosynthesis and hypothesized mechanisms for thermonuclear supernovae. In an effort towards understanding alpha processes from first principles, we describe in this letter the first ab initio calculation of alpha-alpha scattering. We use lattice effective field theory to describe the low-energy interactions of nucleons and apply a technique called the adiabatic projection method to reduce the eight-body system to an effective two-cluster system. We find good agreement between lattice results and experimental phase shifts for S-wave and D-wave scattering. The computational scaling with particle number suggests that alpha processes involving heavier nuclei are also within reach in the near future.

  3. Ab initio molar volumes and Gaussian radii.

    Science.gov (United States)

    Parsons, Drew F; Ninham, Barry W

    2009-02-12

    Ab initio molar volumes are calculated and used to derive radii for ions and neutral molecules using a spatially diffuse model of the electron distribution with Gaussian spread. The Gaussian radii obtained can be used for computation of nonelectrostatic ion-ion dispersion forces that underlie Hofmeister specific ion effects. Equivalent hard-sphere radii are also derived, and these are in reasonable agreement with crystalline ionic radii. The Born electrostatic self-energy is derived for a Gaussian model of the electronic charge distribution. It is shown that the ionic volumes used in electrostatic calculations of strongly hydrated cosmotropic ions ought best to include the first hydration shell. Ionic volumes for weakly hydrated chaotropic metal cations should exclude electron overlap (in electrostatic calculations). Spherical radii are calculated as well as nonisotropic ellipsoidal radii for nonspherical ions, via their nonisotropic static polarizability tensors. PMID:19140766

  4. Ab Initio Path to Heavy Nuclei

    CERN Document Server

    Binder, Sven; Calci, Angelo; Roth, Robert

    2014-01-01

    We present the first ab initio calculations of nuclear ground states up into the domain of heavy nuclei, spanning the range from 16-O to 132-Sn based on two- plus three-nucleon interactions derived within chiral effective field theory. We employ the similarity renormalization group for preparing the Hamiltonian and use coupled-cluster theory to solve the many-body problem for nuclei with closed sub-shells. Through an analysis of theoretical uncertainties resulting from various truncations in this framework, we identify and eliminate the technical hurdles that previously inhibited the step beyond medium-mass nuclei, allowing for reliable validations of nuclear Hamiltonians in the heavy regime. Following this path we show that chiral Hamiltonians qualitatively reproduce the systematics of nuclear ground-state energies up to the neutron-rich Sn isotopes.

  5. Ab initio alpha-alpha scattering

    Science.gov (United States)

    Elhatisari, Serdar; Lee, Dean; Rupak, Gautam; Epelbaum, Evgeny; Krebs, Hermann; Lähde, Timo A.; Luu, Thomas; Meißner, Ulf-G.

    2015-12-01

    Processes such as the scattering of alpha particles (4He), the triple-alpha reaction, and alpha capture play a major role in stellar nucleosynthesis. In particular, alpha capture on carbon determines the ratio of carbon to oxygen during helium burning, and affects subsequent carbon, neon, oxygen, and silicon burning stages. It also substantially affects models of thermonuclear type Ia supernovae, owing to carbon detonation in accreting carbon-oxygen white-dwarf stars. In these reactions, the accurate calculation of the elastic scattering of alpha particles and alpha-like nuclei—nuclei with even and equal numbers of protons and neutrons—is important for understanding background and resonant scattering contributions. First-principles calculations of processes involving alpha particles and alpha-like nuclei have so far been impractical, owing to the exponential growth of the number of computational operations with the number of particles. Here we describe an ab initio calculation of alpha-alpha scattering that uses lattice Monte Carlo simulations. We use lattice effective field theory to describe the low-energy interactions of protons and neutrons, and apply a technique called the ‘adiabatic projection method’ to reduce the eight-body system to a two-cluster system. We take advantage of the computational efficiency and the more favourable scaling with system size of auxiliary-field Monte Carlo simulations to compute an ab initio effective Hamiltonian for the two clusters. We find promising agreement between lattice results and experimental phase shifts for s-wave and d-wave scattering. The approximately quadratic scaling of computational operations with particle number suggests that it should be possible to compute alpha scattering and capture on carbon and oxygen in the near future. The methods described here can be applied to ultracold atomic few-body systems as well as to hadronic systems using lattice quantum chromodynamics to describe the interactions of

  6. Ablation dynamics in laser sclerotomy ab externo

    Science.gov (United States)

    Brinkmann, Ralf; Droege, Gerit; Mohrenstecher, Dirk; Scheu, M.; Birngruber, Reginald

    1996-01-01

    Laser sclerostomy ab externo with flashlamp excited mid-IR laser systems emitting in the 2-3 micrometer spectral range is in phase II clinical trials. Although acutely high success rates were achieved, the restenosis rate after several months is about 40%. Laser pulses of several hundreds of microseconds, known to induce thermo-mechanical explosive evaporation were used for this procedure. We investigated the ablation dynamics in tissue and the cavitation bubble dynamics in water by means of an Er:YAG laser system to estimate the extent of mechanical damage zones in the sclera and in the anterior chamber, which may contribute to the clinical failure. We found substantial mechanical tissue deformation during the ablation process caused by the cavitation effects. Stress waves up to several bar generated by explosive evaporization were measured. The fast mechanical stretching and collapsing of the scleral tissue induced by cavitation resulted in tissue dissection as could be proved by flash photography and histology. The observed high restenosis might be a result of a subsequent enhanced wound healing process. Early fistula occlusions due to iris adherences, observed in about 20% of the clinical cases may be attributed to intraocular trauma induced by vapor bubble expansion through the anterior chamber after scleral perforation. An automatic feedback system minimizing adverse effects by steering and terminating the laser process during scleral fistulization is demonstrated. Moreover, a new approach in laser sclerostomy ab externo is presented using a cw-IR laser diode system emitting at the 1.94 micrometer mid-IR water absorption peak. This system was used in vitro and showed smaller damage zones compared to the pulsed laser radiation.

  7. Ab initio alpha-alpha scattering.

    Science.gov (United States)

    Elhatisari, Serdar; Lee, Dean; Rupak, Gautam; Epelbaum, Evgeny; Krebs, Hermann; Lähde, Timo A; Luu, Thomas; Meißner, Ulf-G

    2015-12-01

    Processes such as the scattering of alpha particles ((4)He), the triple-alpha reaction, and alpha capture play a major role in stellar nucleosynthesis. In particular, alpha capture on carbon determines the ratio of carbon to oxygen during helium burning, and affects subsequent carbon, neon, oxygen, and silicon burning stages. It also substantially affects models of thermonuclear type Ia supernovae, owing to carbon detonation in accreting carbon-oxygen white-dwarf stars. In these reactions, the accurate calculation of the elastic scattering of alpha particles and alpha-like nuclei--nuclei with even and equal numbers of protons and neutrons--is important for understanding background and resonant scattering contributions. First-principles calculations of processes involving alpha particles and alpha-like nuclei have so far been impractical, owing to the exponential growth of the number of computational operations with the number of particles. Here we describe an ab initio calculation of alpha-alpha scattering that uses lattice Monte Carlo simulations. We use lattice effective field theory to describe the low-energy interactions of protons and neutrons, and apply a technique called the 'adiabatic projection method' to reduce the eight-body system to a two-cluster system. We take advantage of the computational efficiency and the more favourable scaling with system size of auxiliary-field Monte Carlo simulations to compute an ab initio effective Hamiltonian for the two clusters. We find promising agreement between lattice results and experimental phase shifts for s-wave and d-wave scattering. The approximately quadratic scaling of computational operations with particle number suggests that it should be possible to compute alpha scattering and capture on carbon and oxygen in the near future. The methods described here can be applied to ultracold atomic few-body systems as well as to hadronic systems using lattice quantum chromodynamics to describe the interactions of

  8. Dois estudos sobre o trabalho dos petroleiros

    Directory of Open Access Journals (Sweden)

    Leda Leal Ferreira

    1996-06-01

    Full Text Available O presente artigo traz um resumo de dois estudos realizados na área do petróleo, o primeiro feito em uma unidade de refino e o segundo abarcando o trabalho de operadores exercendo várias funções dentro de uma refinaria e de terminais marítimos de petróleo. Nos dois casos, o ponto central foi a análise da atividade dos trabalhadores, isto é, o que eles faziam e como o faziam para dai conta das exigências de produção que lhes eram atribuídas. No entanto, os métodos utilizados foram diferentes: no primeiro caso utilizou-se a Análise Ergonômica do Trabalho (AET e no segundo, a Análise Coletiva do Trabalho (ACT. Além de apresentar os principais resultados destes estudos, a autora faz considerações sobre as diferenças entre os dois métodos e um apelo à comunidade científica para que se preocupe mais em estudar a atividade real dos trabalhadores e assim contribuir para um melhor conhecimento do que se passa no interior das unidades produtivas, evitando que sofrimentos humanos inúteis e até catástrofes industriais continuem a ocorrer.This paper describes two studies about petroleum industry. The first was developed in a refinery and the second focuses on the work of operators in various jobs within a refinery and maritime petroleum units. In both cases, the focal point was the analyses of activities, that is, what the workers do and how they do it in order to meet production demandai put on them. However, two different methods were applied in the studies. Ergonomics Work Analyses (EWA was used on the first case and Collective Work Analyses (CWA, on the second. Besides showing the main results, the author compares the two methods. She also draws the scientific community attention to the importance of studding the workers actual activity in order to contribute to a better understanding of what is going on inside production units, avoiding useless human suffering, and the still ocurring undustrial disasters.

  9. Dicty_cDB: FCL-AB06 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available FCL (Link to library) FCL-AB06 (Link to dictyBase) - - - Contig-U15603-1 FCL-AB06P ...(Link to Original site) FCL-AB06F 694 FCL-AB06Z 573 FCL-AB06P 1267 - - Show FCL-AB06 Library FCL (Link to library) Clone ID FCL-...3-1 Original site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/FCL/FCL-AB/FCL-AB06Q....Seq.d/ Representative seq. ID FCL-AB06P (Link to Original site) Representative DNA sequence >FCL-AB06 (FCL-AB06Q) /CSM/FCL/FCL-...AB/FCL-AB06Q.Seq.d/ CAATTTTATCGGAACCATCAATTCATGCAGGTTCTGTATTTAGTATTAATTTAACCAAAT CTAGACA

  10. Kopplung von Dichtefunktional- und ab-initio-Methoden

    OpenAIRE

    Goll, Erich

    2008-01-01

    Im Rahmen der Doktorarbeit wurde untersucht, inwieweit die Kopplung von Dichtefunktionalmethoden und ab-initio-Korrelationsmethoden der Quantenchemie eine Verbesserung bezüglich beider Grenzmethoden erbringt. Die Kopplung erfolgt durch eine Aufspaltung des interelektronischen Hamiltonoperators (abstoßende Coulombwechselwirkung). Die kurzreichweitige Wechselwirkung wird mit Dichtefunktionaltheorie behandelt, die langreichweitige mit Hilfe von ab-initio-Methoden. Diese Aufteilung soll dazu dien...

  11. 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.

  12. 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 represen

  13. 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

  14. Estudo retrospectivo de latrodectismo na Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    Rejâne Maria Lira-da-Silva

    1995-09-01

    Full Text Available O trabalho apresenta um estudo retrospectivo de setenta e sete casos de latrodectismo no Estado da Bahia, Brasil, de agosto de 1980 a julho de 1990. Os dados foram levantados nos livros de registro e arquivo de fichas do CIAVE. O agente etiológico em 28% dos acidentes aracnídeos foi a espécie L. curacaviensis e a maior incidência foi registrada no meio urbano (57%, em indivíduos do sexo masculino (70% e faixa etária de 10 a 29 anos (58%. Os principais sinais locais foram dor (56%, pápula eritematosa (21% e edema discreto (17%, e os sistêmicos foram dor em membros inferiores (29%, tremores e contraturas (29%, sudorese (28% parestesia em membros (21% e dor abdominal (17%. O tratamento foi sintomático em 67% dos casos e específico em 21%. O tempo de permanência hospitalar após o uso do soro antilatrodectus foi menor que 24 horas em 64% dos casos.

  15. Preparation of grafted ABS and compatibilization of r-PET/ABS blends by the grafted ABS%ABS接枝物的制备及其对r-PET/ABS的增容作用

    Institute of Scientific and Technical Information of China (English)

    陈智军; 王益龙; 郑辰

    2012-01-01

    Two kinds of grafted acrylonitrile-butadiene-styrene copolymer(ABS), i.e. maleic anhydride (MAH) grafted ABS(ABS-g-MAH) and glycidyl methacrylate (GMA) grafted ABS (ABS-g-GMA), were prepared via reactive extrusion and were used as compatibilizer for recycled polyethylene glycol terephthalate (r-PET)/ABS blends. The results show that ABS-g-MAH and ABS-g-GMA can greatly improve the impact strength of the blends. ABS-g-MAH is superior to ABS-g-GMA in compatibilization effect. The optimal compatibilization effect is acquired when the grafting ratio of ABS-g-MAH is 1.35% and the mass content of the copolymer is 5%. Under such conditions, the notched and unnotched *Charpy impact strength of the r-PET/ABS/ABS-g--MAH blends rise by 42% and 23%, respectively, in comparison with those of r-PET/ ABS. The observation by scanning electron microscope(SEM) shows that adding grafted ABS can make ABS be dispersed more homogeneously in the r-PET continuous phase and make particle size more even.%通过反应挤出法制备马来酸酐(MAH)接枝丙烯腈-丁二烯-苯乙烯三元共聚物(ABS)(ABS-g-MAH)和甲基丙烯酸缩水甘油酯(GMA)接枝ABS(ABS-g-GMA),将其用于增容回收聚对苯二甲酸乙二酯(PET)瓶片(r-PET)/ABS共混物,发现能显著提高其混物的冲击强度.ABS-g-MAH的增容效果优于ABS-g-GMA;ABS-g-MAH的接枝率为1.35%,w(ABS-g-MAH)为5%时对r-PET/ABS的增容作用最佳,此时r-PET/ABS/ABS-g-MAH的简支梁缺口冲击强度和无缺口冲击强度比r-PET/ABS分别提高了42%和23%.扫描电子显微镜观察表明,加入ABS接枝物能使ABS在r-PET连续相中的分散更均匀,粒径尺寸更均一.

  16. Structural and biophysical characterization of Bacillus thuringiensis insecticidal proteins Cry34Ab1 and Cry35Ab1.

    Directory of Open Access Journals (Sweden)

    Matthew S Kelker

    Full Text Available Bacillus thuringiensis strains are well known for the production of insecticidal proteins upon sporulation and these proteins are deposited in parasporal crystalline inclusions. The majority of these insect-specific toxins exhibit three domains in the mature toxin sequence. However, other Cry toxins are structurally and evolutionarily unrelated to this three-domain family and little is known of their three dimensional structures, limiting our understanding of their mechanisms of action and our ability to engineer the proteins to enhance their function. Among the non-three domain Cry toxins, the Cry34Ab1 and Cry35Ab1 proteins from B. thuringiensis strain PS149B1 are required to act together to produce toxicity to the western corn rootworm (WCR Diabrotica virgifera virgifera Le Conte via a pore forming mechanism of action. Cry34Ab1 is a protein of ∼14 kDa with features of the aegerolysin family (Pfam06355 of proteins that have known membrane disrupting activity, while Cry35Ab1 is a ∼44 kDa member of the toxin_10 family (Pfam05431 that includes other insecticidal proteins such as the binary toxin BinA/BinB. The Cry34Ab1/Cry35Ab1 proteins represent an important seed trait technology having been developed as insect resistance traits in commercialized corn hybrids for control of WCR. The structures of Cry34Ab1 and Cry35Ab1 have been elucidated to 2.15 Å and 1.80 Å resolution, respectively. The solution structures of the toxins were further studied by small angle X-ray scattering and native electrospray ion mobility mass spectrometry. We present here the first published structure from the aegerolysin protein domain family and the structural comparisons of Cry34Ab1 and Cry35Ab1 with other pore forming toxins.

  17. 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.

  18. Ab initio calculation of the Hoyle state

    CERN Document Server

    Epelbaum, Evgeny; Lee, Dean; Meißner, Ulf-G

    2011-01-01

    The Hoyle state plays a crucial role in the hydrogen burning of stars heavier than our sun and in the production of carbon and other elements necessary for life. This excited state of the carbon-12 nucleus was postulated by Hoyle^{1} as a necessary ingredient for the fusion of three alpha particles to produce carbon at stellar temperatures. Although the Hoyle state was seen experimentally more than a half century ago^{2,3}, nuclear theorists have not yet uncovered the nature of this state from first principles. In this letter we report the first ab initio calculation of the low-lying states of carbon-12 using supercomputer lattice simulations and a theoretical framework known as effective field theory. In addition to the ground state and excited spin-2 state, we find a resonance at -85(3) MeV with all of properties of the Hoyle state and in agreement with the experimentally observed energy. These lattice simulations provide insight into the structure of this unique state and new clues as to the amount of fine...

  19. Estudo retrospectivo de latrodectismo na Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    Rejâne Maria Lira-da-Silva

    1995-09-01

    Full Text Available O trabalho apresenta um estudo retrospectivo de setenta e sete casos de latrodectismo no Estado da Bahia, Brasil, de agosto de 1980 a julho de 1990. Os dados foram levantados nos livros de registro e arquivo de fichas do CIAVE. O agente etiológico em 28% dos acidentes aracnídeos foi a espécie L. curacaviensis e a maior incidência foi registrada no meio urbano (57%, em indivíduos do sexo masculino (70% e faixa etária de 10 a 29 anos (58%. Os principais sinais locais foram dor (56%, pápula eritematosa (21% e edema discreto (17%, e os sistêmicos foram dor em membros inferiores (29%, tremores e contraturas (29%, sudorese (28% parestesia em membros (21% e dor abdominal (17%. O tratamento foi sintomático em 67% dos casos e específico em 21%. O tempo de permanência hospitalar após o uso do soro antilatrodectus foi menor que 24 horas em 64% dos casos.This work is a retrospective study of latrodectism in the State of Bahia, Brazil, from August 1980 to July 1990. The data concerning the accidents were obtained from file cards at the Antivenom Information Center of Bahia (AVICB. Latrodectus curacavienis was the ethiologic agent identified in 28% of the arachnid accidents. The major incidence was registered in urban area (57% affecting men (70% more than women, with 10 to 29year-old age group (58%. Local pain (56%, erythematous papula (29% and light oedema (17% were the principal local symptoms. Pain in the limbs (29%, tremor and rigidities (29%, sweating (28%, limbs and arms paresthesia (21% and abdominal pain (17% were systemic ones. The treatment was mainly symptomatic (67% and antivenin serum was used in 21% of the cases. After serotherapy, 64% of the patients left the hospital within less than 24 hours.

  20. 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

  1. Current techniques for AB0-incompatible living donor liver transplantation

    Science.gov (United States)

    Rummler, Silke; Bauschke, Astrid; Bärthel, Erik; Jütte, Heike; Maier, Katrin; Ziehm, Patrice; Malessa, Christina; Settmacher, Utz

    2016-01-01

    For a long time, it was considered medical malpractice to neglect the blood group system during transplantation. Because there are far more patients waiting for organs than organs available, a variety of attempts have been made to transplant AB0-incompatible (AB0i) grafts. Improvements in AB0i graft survival rates have been achieved with immunosuppression regimens and plasma treatment procedures. Nevertheless, some grafts are rejected early after AB0i living donor liver transplantation (LDLT) due to antibody mediated rejection or later biliary complications that affect the quality of life. Therefore, the AB0i LDLT is an option only for emergency situations, and it requires careful planning. This review compares the treatment possibilities and their effect on the patients’ graft outcome from 2010 to the present. We compared 11 transplant center regimens and their outcomes. The best improvement, next to plasma treatment procedures, has been reached with the prophylactic use of rituximab more than one week before AB0i LDLT. Unfortunately, no standardized treatment protocols are available. Each center treats its patients with its own scheme. Nevertheless, the transplant results are homogeneous. Due to refined treatment strategies, AB0i LDLT is a feasible option today and almost free of severe complications. PMID:27683633

  2. On the hierarchical parallelization of ab initio simulations

    CERN Document Server

    Ruiz-Barragan, Sergi; Shiga, Motoyuki

    2016-01-01

    A hierarchical parallelization has been implemented in a new unified code PIMD-SMASH for ab initio simulation where the replicas and the Born-Oppenheimer forces are parallelized. It is demonstrated that ab initio path integral molecular dynamics simulations can be carried out very efficiently for systems up to a few tens of water molecules. The code was then used to study a Diels-Alder reaction of cyclopentadiene and butenone by ab initio string method. A reduction in the reaction energy barrier is found in the presence of hydrogen-bonded water, in accordance with experiment.

  3. Ab initio derivation of model energy density functionals

    Science.gov (United States)

    Dobaczewski, Jacek

    2016-08-01

    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.

  4. Estudo de caso: disfonia psicogênica

    Directory of Open Access Journals (Sweden)

    Marcela Bergamini

    2015-02-01

    Full Text Available Disfonia funcional psicogênica possui relação com aspectos psicológicos. O tipo de voz, a articulação e a fluência são sensíveis às oscilações psicológicas. Uma voz em ajuste de falsete paralítico, caracterizada como uma voz de pitch extremamente agudo pode ser encontrada em casos de disfonias psicogênicas. Em qualquer quadro psicogênico é essencial um diagnóstico diferencial, a fim de viabilizar um tratamento fonoaudiológico e médico adequados e efetivos. O prognóstico de uma alteração psicogênica geralmente é bom. O quadro de disfonia psicogênica é mais comum no sexo feminino. O objetivo desse estudo é apresentar a evolução terapêutica de um indivíduo com disfonia psicogênica. A.J.O., 45 anos, sexo masculino, compareceu ao Ambulatório de Avaliação e Terapia de Voz encaminhado por médico otorrinolaringologista. Trouxe a queixa vocal "pela manhã a voz está perfeita, conforme o dia passa, a voz fica fina". Realizou avaliação fonoaudiológica em 18 de abril de 2013, com laudo médico de "mobilidade reduzida de prega vocal esquerda". Tratamento com técnica de sons disparadores, com modificação direta nos sintomas e evolução rápida. Demonstrou-se satisfeito com sua qualidade vocal. Em casos de suspeita de disfonias psicogênicas de conversão, devem-se descartar alterações orgânicas, sendo essencial uma avaliação fonoaudiológica que auxilie no diagnóstico diferencial e provas terapêuticas que incentivem o paciente.

  5. Eritema ab igne: relato de um caso Erythema ab igne: a case report

    Directory of Open Access Journals (Sweden)

    Magda Blessmann Weber

    2005-04-01

    Full Text Available A lesão cutânea do eritema ab igne é caracterizada por eritema reticulado, hiperpigmentação, descamação fina, atrofia epidérmica e telangiectasias. Atualmente, a região lombar é a mais atingida, devido ao uso de bolsas de água quente, para alívio de dores crônicas, e por constantes exposições a calor profundo em sessões de fisioterapia. Os autores alertam sobre uma dermatose pouco diagnosticada e que talvez seja mais prevalente pela alta freqüência com que são realizados tratamentos fisioterápicos.The cutaneous lesion of erythema ab igne is characterized by a reticulate erythema, hyperpigmentation, fine scaling, epidermal atrophy and telangiectasis. Currently the lumbar region is the most affected, due to the use of hot water bottles to relieve chronic pains, and by constant exposure to deep heat in physiotherapy sessions. The authors call attention to a dermatosis that is not often diagnosed, and that may be more prevalent, because of the high frequency with which such physiotherapeutic treatments are performed.

  6. 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.

  7. Tensile deformation mechanisms of ABS/PMMA/EMA blends

    Science.gov (United States)

    Wang, S. H.; Gao, J.; Lin, S. X.; Zhang, P.; Huang, J.; Xu, L. L.

    2014-08-01

    The tensile deformation mechanisms of acrylonitrile - butadiene - styrene (ABS) / polymethyl methacrylate (PMMA) blends toughened by ethylene methacrylate (EMA) copolymer was investigated by analysing the fracture morphology. ABS/PMMA was blended with EMA copolymer by melt mixing technique using co-rotating twin extruder. Tensile tests show that the elongation at break of ABS/PMMA blends can be efficiently improved with the increase in EMA content. Fracture morphology of ABS/PMMA/EMA blends reveals that the material yield induced by hollowing-out of EMA particles and its propagation into yield zone is the main toughening mechanism. Moreover, the appearance that EMA particles in the central area are given priority to hollowing-out may be related to the skin-core structure of the injection moulded parts caused by the different cooling rate between surface and inside in the process of injection moulding.

  8. 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.

  9. Evaluation of the Urotest AB antibacterial substance detection test.

    OpenAIRE

    Blondeau, J. M.; Yaschuk, Y; Galenzoski, D; Hrabok, D; Isaacson, M; Lee, L.(Department of Physics, Yale University, New Haven, CT, USA); Link, H; Walshaw, L

    1994-01-01

    The Urotest AB was used to detect antimicrobial substances in urine samples. Of 1022 urine specimens evaluated, Urotest AB detected inhibitors in 38.9%. Of 159 urine specimens from patients thought to be taking an antibiotic, inhibitors were detected in 80.5%. This test may help to explain culture negative urine samples from symptomatic patients, and could help elucidate treatment failures and the epidemiology of antibiotic resistance.

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

    OpenAIRE

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

    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. For the first time the modulus is evaluated ab initio (no bias from experimental data) with demonstrated basis set convergence.

  11. 基于ABS的ABS/ASR集成液压系统设计%ABS/ASR Integrated Hydraulic System Based on ABS

    Institute of Scientific and Technical Information of China (English)

    马岳峰; 刘昭度; 吴利军; 王国业

    2004-01-01

    介绍一种基于JETTA GTX轿车ABS液压系统的ABS/ASR集成液压系统改造方案,该ABS/ASR集成液压系统在原有ABS液压系统的基础上增加较少的液压元件实现全部ABS功能和ASR制动干预控制功能,改造后的集成系统工作可靠,不影响原有的常规制动和ABS制动过程.

  12. Ab Initio No-Core Shell Model

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, B R; Navratil, P; Vary, J P

    2011-04-11

    A long-standing goal of nuclear theory is to determine the properties of atomic nuclei based on the fundamental interactions among the protons and neutrons (i.e., nucleons). By adopting nucleon-nucleon (NN), three-nucleon (NNN) and higher-nucleon interactions determined from either meson-exchange theory or QCD, with couplings fixed by few-body systems, we preserve the predictive power of nuclear theory. This foundation enables tests of nature's fundamental symmetries and offers new vistas for the full range of complex nuclear phenomena. Basic questions that drive our quest for a microscopic predictive theory of nuclear phenomena include: (1) What controls nuclear saturation; (2) How the nuclear shell model emerges from the underlying theory; (3) What are the properties of nuclei with extreme neutron/proton ratios; (4) Can we predict useful cross sections that cannot be measured; (5) Can nuclei provide precision tests of the fundamental laws of nature; and (6) Under what conditions do we need QCD to describe nuclear structure, among others. Along with other ab initio nuclear theory groups, we have pursued these questions with meson-theoretical NN interactions, such as CD-Bonn and Argonne V18, that were tuned to provide high-quality descriptions of the NN scattering phase shifts and deuteron properties. We then add meson-theoretic NNN interactions such as the Tucson-Melbourne or Urbana IX interactions. More recently, we have adopted realistic NN and NNN interactions with ties to QCD. Chiral perturbation theory within effective field theory ({chi}EFT) provides us with a promising bridge between QCD and hadronic systems. In this approach one works consistently with systems of increasing nucleon number and makes use of the explicit and spontaneous breaking of chiral symmetry to expand the strong interaction in terms of a dimensionless constant, the ratio of a generic small momentum divided by the chiral symmetry breaking scale taken to be about 1 GeV/c. The

  13. Ab Initio No-Core Shell Model

    International Nuclear Information System (INIS)

    A long-standing goal of nuclear theory is to determine the properties of atomic nuclei based on the fundamental interactions among the protons and neutrons (i.e., nucleons). By adopting nucleon-nucleon (NN), three-nucleon (NNN) and higher-nucleon interactions determined from either meson-exchange theory or QCD, with couplings fixed by few-body systems, we preserve the predictive power of nuclear theory. This foundation enables tests of nature's fundamental symmetries and offers new vistas for the full range of complex nuclear phenomena. Basic questions that drive our quest for a microscopic predictive theory of nuclear phenomena include: (1) What controls nuclear saturation; (2) How the nuclear shell model emerges from the underlying theory; (3) What are the properties of nuclei with extreme neutron/proton ratios; (4) Can we predict useful cross sections that cannot be measured; (5) Can nuclei provide precision tests of the fundamental laws of nature; and (6) Under what conditions do we need QCD to describe nuclear structure, among others. Along with other ab initio nuclear theory groups, we have pursued these questions with meson-theoretical NN interactions, such as CD-Bonn and Argonne V18, that were tuned to provide high-quality descriptions of the NN scattering phase shifts and deuteron properties. We then add meson-theoretic NNN interactions such as the Tucson-Melbourne or Urbana IX interactions. More recently, we have adopted realistic NN and NNN interactions with ties to QCD. Chiral perturbation theory within effective field theory (χEFT) provides us with a promising bridge between QCD and hadronic systems. In this approach one works consistently with systems of increasing nucleon number and makes use of the explicit and spontaneous breaking of chiral symmetry to expand the strong interaction in terms of a dimensionless constant, the ratio of a generic small momentum divided by the chiral symmetry breaking scale taken to be about 1 GeV/c. The resulting NN

  14. Bacillus thuringiensis Cry34Ab1/Cry35Ab1 Interactions with Western Corn Rootworm Midgut Membrane Binding Sites

    OpenAIRE

    Huarong Li; Monica Olson; Gaofeng Lin; Timothy Hey; Sek Yee Tan; Narva, Kenneth E.

    2013-01-01

    BACKGROUND: Bacillus thuringiensis (Bt) Cry34Ab1/Cry35Ab1 are binary insecticidal proteins that are co-expressed in transgenic corn hybrids for control of western corn rootworm, Diabrotica virgifera virgifera LeConte. Bt crystal (Cry) proteins with limited potential for field-relevant cross-resistance are used in combination, along with non-transgenic corn refuges, as a strategy to delay development of resistant rootworm populations. Differences in insect midgut membrane binding site interact...

  15. Desenvolvimento da Tanatologia: estudos sobre a morte e o morrer

    Directory of Open Access Journals (Sweden)

    Maria Julia Kovács

    2008-12-01

    Full Text Available Este artigo discute os principais temas e pesquisas na área da Tanatologia, estudos sobre a morte e o morrer. São apresentados os autores pioneiros que escreveram as primeiras obras de sistematização da Tanatologia entre os quais: Herman Feifel, Robert Kastenbaum e Elizabeth Kübler-Ross, e os principais temas de estudo: luto, violência e guerra, a morte e a TV, cuidados a pacientes gravemente enfermos, além da formação de profissionais da área de saúde e educação para lidar com pessoas vivendo situações de perdas e morte. São feitas propostas de estudos para o futuro desenvolvimento da Tanatologia em nosso país.

  16. Voluntariado empresarial e a empresa : estudo do caso Unicer

    OpenAIRE

    Pavia, Bernardo Nuno Andrade Barreiros

    2014-01-01

    O voluntariado empresarial é hoje uma componente da responsabilidade social das empresas cada vez mais importante e determinante na estratégia de comunicação com os seus diferentes stakeholders. Este estudo procurou perceber de que forma o voluntariado empresarial é visto e entendido pelas empresas, pelos seus colaboradores e, que tipo de intervenções são prática na relação com a comunidade. O estudo procurou também analisar as motivações e os benefícios das ações de voluntariado empresari...

  17. Desenvolvimento da Tanatologia: estudos sobre a morte e o morrer

    OpenAIRE

    Maria Julia Kovács

    2008-01-01

    Este artigo discute os principais temas e pesquisas na área da Tanatologia, estudos sobre a morte e o morrer. São apresentados os autores pioneiros que escreveram as primeiras obras de sistematização da Tanatologia entre os quais: Herman Feifel, Robert Kastenbaum e Elizabeth Kübler-Ross, e os principais temas de estudo: luto, violência e guerra, a morte e a TV, cuidados a pacientes gravemente enfermos, além da formação de profissionais da área de saúde e educação para lidar com pessoas vivend...

  18. Dicty_cDB: FCL-AB19 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available FCL (Link to library) FCL-AB19 (Link to dictyBase) - - - Contig-U15232-1 FCL-AB19Z ...(Link to Original site) - - FCL-AB19Z 697 - - - - Show FCL-AB19 Library FCL (Link to library) Clone ID FCL-A... http://dictycdb.biol.tsukuba.ac.jp/CSM/FCL/FCL-AB/FCL-AB19Q.Seq.d/ Representative seq. ID FCL-...AB19Z (Link to Original site) Representative DNA sequence >FCL-AB19 (FCL-AB19Q) /CSM/FCL/FCL-AB/FCL-...KLINFSIFQ* Homology vs CSM-cDNA Score E Sequences producing significant alignments: (bits) Value FCL-

  19. Ab Initio Studies of Stratospheric Ozone Depletion Chemistry

    Science.gov (United States)

    Lee, Timothy J.; Head-Gordon, Martin; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    An overview of the current understanding of ozone depletion chemistry, particularly with regards the formation of the so-called Antarctic ozone hole, will be presented together with an outline as to how ab initio quantum chemistry can be used to further our understanding of stratospheric chemistry. The ability of modern state-of-the art ab initio quantum chemical techniques to characterize reliably the gas-phase molecular structure, vibrational spectrum, electronic spectrum, and thermal stability of fluorine, chlorine, bromine and nitrogen oxide species will be demonstrated by presentation of some example studies. The ab initio results will be shown to be in excellent agreement with the available experimental data, and where the experimental data are either not known or are inconclusive, the theoretical results are shown to fill in the gaps and to resolve experimental controversies. In addition, ab initio studies in which the electronic spectra and the characterization of excited electronic states of halogen oxide species will also be presented. Again where available, the ab initio results are compared to experimental observations, and are used to aid in the interpretation of experimental studies.

  20. The over-expression of two transcription factors, ABS5/bHLH30 and ABS7/MYB101, leads to upwardly curly leaves.

    Directory of Open Access Journals (Sweden)

    Rui An

    Full Text Available Proper leaf development is essential for plant growth and development, and leaf morphogenesis is under the control of intricate networks of genetic and environmental cues. We are interested in dissecting these regulatory circuits genetically and report here the isolation of two Arabidopsis dominant mutants, abnormal shoot5-1D (abs5-1D and abs7-1D identified through activation tagging screens. Both abs5-1D and abs7-1D display an intriguing upwardly curly leaf phenotype. Molecular cloning showed that the elevated expression of a bHLH transcription factor ABS5/T5L1/bHLH30 or a MYB transcription factor ABS7/MYB101 is the cause for the abnormal leaf phenotypes found in abs5-1D or abs7-1D, respectively. Protoplast transient expression assays confirmed that both ABS5/T5L1 and ABS7/MYB101 are targeted to the nucleus. Interestingly, the expression domains of auxin response reporter DR5::GUS were abnormal in leaves of abs5-1D and ABS5/T5L1 over-expression lines. Moreover, cotyledon venation analysis showed that more areoles and free-ending veins are formed in abs5-1D. We found that the epidermis-specific expressions of ABS5/T5L1 or ABS7/MYB101 driven by the Arabidopsis Meristem Layer 1 promoter (PAtML1 were sufficient to recapitulate the curly leaf phenotype of abs5-1D or abs7-1D. In addition, PAtML1::ABS5 lines exhibited similar changes in DR5::GUS expression patterns as those found in 35S-driven ABS5/T5L1 over-expression lines. Our work demonstrated that enhanced expressions of two transcription factors, ABS5/T5L1 and ABS7/MYB101, are able to alter leaf lamina development and reinforce the notion that leaf epidermis plays critical roles in regulating plant organ morphogenesis.

  1. Ab initio simulation of transport phenomena in rarefied gases.

    Science.gov (United States)

    Sharipov, Felix; Strapasson, José L

    2012-09-01

    Ab initio potentials are implemented into the direct simulation Monte Carlo (DSMC) method. Such an implementation allows us to model transport phenomena in rarefied gases without any fitting parameter of intermolecular collisions usually extracted from experimental data. Applying the method proposed by Sharipov and Strapasson [Phys. Fluids 24, 011703 (2012)], the use of ab initio potentials in the DSMC requires the same computational efforts as the widely used potentials such as hard spheres, variable hard sphere, variable soft spheres, etc. At the same time, the ab initio potentials provide more reliable results than any other one. As an example, the transport coefficients of a binary mixture He-Ar, viz., viscosity, thermal conductivity, and thermal diffusion factor, have been calculated for several values of the mole fraction. PMID:23030889

  2. Simplest AB-Thermonuclear Space Propulsion and Electric Generator

    CERN Document Server

    Bolonkin, A

    2007-01-01

    The author applies, develops and researches mini-sized Micro- AB Thermonuclear Reactors for space propulsion and space power systems. These small engines directly convert the high speed charged particles produced in the thermonuclear reactor into vehicle thrust or vehicle electricity with maximum efficiency. The simplest AB-thermonuclear propulsion offered allows spaceships to reach speeds of 20,000 50,000 km/s (1/6 of light speed) for fuel ratio 0.1 and produces a huge amount of useful electric energy. Offered propulsion system permits flight to any planet of our Solar system in short time and to the nearest non-Sun stars by E-being or intellectual robots during a single human life period. Key words: AB-propulsion, thermonuclear propulsion, space propulsion, thermonuclear power system.

  3. Surface Modification of AB2. and AB5 Hydrogen Storage Alloy Electrodes by the Hot-Charging Treatment

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effect of the hot-charging treatment on the performance ofAB2 and AB5 hydrogen storage alloy electrodes was investigated. The result showed that the treatment can markedly improve the voltage plateau ratio (VPR), the high rate discharge ability (HRDA), the diffusion coefficient of hydrogen DH and the discharge capacity of the AB2 hydrogen storage alloy electrode. The SEM analysis showed that the hot-charging treatment brings about a Ni-rich surface due to the dissolution of Zr oxides. It is also very helpful for the improvement of the kinetic properties of AB2 hydrogen storage alloy electrode because the microcracking o.f the surface results in fresh surface. This can be the basic modification treatment for NiMH battery used in electric vehicles (EVs) in the future. But for AB5 type alloys, the treatment has the disadvantage of impairing the comprehensive electrochemical properties, because the surface of the alloy may be corroded during the treatment. The mechanism of the surface modification of the electrode is also proposed.

  4. Stimulation of UvrD helicase by UvrAB.

    Science.gov (United States)

    Atkinson, John; Guy, Colin P; Cadman, Chris J; Moolenaar, Geri F; Goosen, Nora; McGlynn, Peter

    2009-04-01

    Helicases play critical roles in all aspects of nucleic acid metabolism by catalyzing the remodeling of DNA and RNA structures. UvrD is an abundant helicase in Escherichia coli with well characterized functions in mismatch and nucleotide excision repair and a possible role in displacement of proteins such as RecA from single-stranded DNA. The mismatch repair protein MutL is known to stimulate UvrD. Here we show that the nucleotide excision repair proteins UvrA and UvrB can together stimulate UvrD-catalyzed unwinding of a range of DNA substrates containing strand discontinuities, including forked DNA substrates. The stimulation is specific for UvrD, as UvrAB failed to stimulate Rep helicase, a UvrD homologue. Moreover, although UvrAB can promote limited strand displacement, stimulation of UvrD did not require the strand displacement function of UvrAB. We conclude that UvrAB, like MutL, modulate UvrD helicase activity. This stimulation likely plays a role in DNA strand and protein displacement by UvrD in nucleotide excision repair. Promotion of UvrD-catalyzed unwinding of nicked duplexes by UvrAB may also explain the need for UvrAB and UvrD in Okazaki fragment processing in cells lacking DNA polymerase I. More generally, these data support the idea that helicase activity is regulated in vivo, with helicases acting as part of multisubunit complexes rather than in isolation. PMID:19208629

  5. AB Levitrons and their Applications to Earth's Motionless Satellites

    CERN Document Server

    Bolonkin, Alexander

    2007-01-01

    Author offers the new and distinctly revolutionary method of levitation in artificial magnetic field. It is shown that a very big space station and small satellites may be suspended over the Earth's surface and used as motionless radio-TV translators, telecommunication boosters, absolute geographic position locators, personal and mass entertainment and as planet-observation platforms. Presented here is the theory of big AB artificial magnetic field and levitation in it is generally developed. Computation of three macro-projects: space station at altitude 100 km, TV-communication antenna at height 500 m, and multi-path magnetic highway. Key words: levitation, AB Levitrons, motionless space satellite.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  8. Intern kontroll : - En studie om Schroff Scandinavia ABs interna kontroll

    OpenAIRE

    Huldt, Martin; Björksved, Patrick

    2014-01-01

    Sammanfattning: ”Intern kontroll- En studie om Schroff Scandinavia ABs interna kontroll” Datum:  2014-06-11 Nivå: Kandidatuppsats i företagsekonomi, 15 ECTS Institution: Akademin för Ekonomi, Samhälle och Teknik, EST,                 Mälardalen Högskola Författare: Patrick Björksved, Martin Huldt Titel: Intern kontroll- En studie om Schroff Scandinavia ABs interna kontroll Handledare : Magnus Linderström Nyckelord: Intern kontroll, intern revision, intern styrning, COSO-modellen, Lean product...

  9. Utveckling av ergoterapitjänster vid Helsingfors ergoterapi Ab

    OpenAIRE

    Sandells, Linn

    2015-01-01

    Syftet med examensarbetet är att ta fram kvalitativa rekommendationer på ergoterapitjänster för barn i behov av särskilt stöd. Det har gjorts genom en processinriktad metod, rekommendationerna på ergoterapitjänster har tagits fram för Helsingfors ergoterapi Ab. Aktivitetsrättvisa är den teoretiska referensramen i arbetet. Den frågeställning som besvarats är vilka ergoterapitjänster kan rekommenderas till Helsingfors ergoterapi Ab. För att uppnå resultatet har materialinsamling och intervjuer ...

  10. Bruksmakt och maktbruk : Robertsfors AB 1897-1968

    OpenAIRE

    Holmström, Per

    1988-01-01

    This thesis studies seven strategic decisions made in the family-owned forestry company Robertsfors AB, in Northern Sweden. During the present century Ro­bertsfors AB has developed from a patriarchally concern controlled into a capi­talistic industrial company. This also meant a radical change in the decision­making process. Two factors were decisive in this process: the managing direc­tor's values, and altered power relationships both within the company and exter­nally in relation to e g sta...

  11. P-V Relation for Mercuric Calcogenides: Ab Initio Method

    Directory of Open Access Journals (Sweden)

    G. Misra

    2011-01-01

    Full Text Available Mercuric Calcogenides found many applications in electronic and optical devices as semiconducting materials. An equation of state provides useful information about the relationship between pressure (P, volume (V and temperature (T that helps to understand the behaviour of materials under the effect of high pressure and high temperature. The present paper sheds light on the electronic structure of Mercuric Calcogenides by simulating its electronic properties through ab initio method. This ab initio method is extended to derive the equation of state for Mercuric Calcogenides. The present equation of state has also been tested for the prediction of End Point. The computed results compare well with Quantum statistical data.

  12. Towards new horizons in ab initio nuclear structure theory

    International Nuclear Information System (INIS)

    We review recent advances in ab initio nuclear structure theory, which have changed the horizons of this field. Starting from chiral effective field theory to construct the nuclear Hamiltonian and the similarity renormalization group to further soften it, we address several many-body approaches that have seen major developments over the past few years. We show that the domain of ab initio nuclear structure theory has been pushed well beyond the p-shell and that quantitative QCD-based predictions are becoming possible all the way from the proton to the neutron drip line up into the medium-mass regime. (authors)

  13. Recent achievements in ab initio modelling of liquid water

    CERN Document Server

    Khaliullin, Rustam Z

    2013-01-01

    The application of newly developed first-principle modeling techniques to liquid water deepens our understanding of the microscopic origins of its unusual macroscopic properties and behaviour. Here, we review two novel ab initio computational methods: second-generation Car-Parrinello molecular dynamics and decomposition analysis based on absolutely localized molecular orbitals. We show that these two methods in combination not only enable ab initio molecular dynamics simulations on previously inaccessible time and length scales, but also provide unprecedented insights into the nature of hydrogen bonding between water molecules. We discuss recent applications of these methods to water clusters and bulk water.

  14. 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.

  15. ESTUDOS CULTURAIS E ESTUDOS DE GÊNERO: PROPOSIÇÕES E ENTRELACES ÀS PESQUISAS EDUCACIONAIS

    Directory of Open Access Journals (Sweden)

    Dinah Quesada Beck

    2013-09-01

    Full Text Available Este artigo tem o interesse de proporcionar ao/a leitor/a uma análise acerca da relação estabelecida entre dois distintos campos de estudos, os Estudos de Gênero e os Estudos Culturais, os quais têm fundamentado as pesquisas desenvolvidas no âmbito das temáticas que têm mobilizado nossos estudos e investigações, sejam elas infância, cultura, consumo, gênero, sexualidade, embelezamento, produção e política dos corpos. Para tanto, nos ocuparemos, nessa argumentação, com alguns movimentos discursivos: após situar a importância atribuída a esses campos nas pesquisas educacionais vinculadas a perspectiva pós-estruturalista de análise, bem como o modo como operamos com eles, interessa-nos discutir e problematizar algumas de suas características, demarcando sua profícua relação. Finalizamos essa narrativa ressaltando suas contribuições em nossas investigações que discutem a produção de identidades de gênero e culturais à infância contemporânea.

  16. 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.

  17. Study on the Mechanical and Friction Properties of Ethylene Propylene Diene Terpolymer/Vinyl Silicon Rubber Foam Materials%三元乙丙橡胶/乙烯基硅橡胶泡沫材料的力学性能与摩擦性能研究

    Institute of Scientific and Technical Information of China (English)

    雷卫华; 罗世凯; 花成; 王晓英

    2013-01-01

    The mechanical and friction properties of the foam materials of ethylene propylene diene terpolymer/ vinyl silicone rubber blend were studied. The results show that, while the vinyl silicone rubber content increasing, the hardness, tensile strength and compressive modulus at break of the rubber foams were decreased, the coefficient of friction (COF) was initially reduced, and then increased. While the testing temperature and pressure increasing, the COF of the foam materials reduced. The COF of the foam materials increased while the dosage of processing oil increasing and curative reducing.%研究了三元乙丙橡胶/乙烯基硅橡胶泡沫材料的力学性能,并表征了泡沫的摩擦性能.实验结果表明,随着乙烯基硅橡胶的含量增加,泡沫材料的硬度、拉伸强度和压缩模量呈下降的趋势,而静摩擦系数先下降后轻微上升;随着正压力和温度的升高,橡胶泡沫材料的静摩擦系数逐渐减小;随着硫化剂用量的减小和操作油用量的增加,橡胶泡沫的静摩擦系数上升.

  18. GJ 282 AB (WDS 07400-0336 AB = BGH 3 AB) and GICLAS 112-29: A Very Wide System in Process of Dissociation

    Science.gov (United States)

    Rica, F. M.; Benavides, R.

    2016-04-01

    Very wide binaries are interesting objects that shed light on the binary formation process and their dynamical evolution. Poveda et al. (2009) studied the possible physical relation of the near (14.2 pc) and wide (~58") binary star GJ 282 AB and the extremely wide (1.09º; ~55,000 AU) companion, NLTT 18149, and they concluded that this very wide system is in the process of dynamical disintegration. In this work, we confirm the same conclusion but using a different method. We first study dynamically GJ 282 AB, confirmed that it is a bound system and then we determine possible orbital solutions. Later, we calculate the relative velocity of NLTT 18149 with respect to the GJ 282 AB's center mass using their (U, V, W) galactocentric velocity. The relative velocity, Vrel = 1.98 ± 0.16 km s-1, is much larger than the escape velocity (0.25 ± 0.01 km s-1). Therefore, with a significance level of 11s, we also conclude that this very wide system is in a process of dynamical disintegration.

  19. Flocos desidratados de abóbora na prevenção da carência de vitamina A em pré-escolares de uma creche

    Directory of Open Access Journals (Sweden)

    Carmem Lygia Burgos Ambrósio

    2012-02-01

    Full Text Available OBJETIVO: Esta pesquisa teve como objetivo avaliar a eficácia de flocos desidratados de abóbora na elevação dos níveis séricos de retinol e a resposta relativa à dose em pré-escolares. MÉTODOS: A ingestão de vitamina A foi avaliada por meio de inquérito dietético. Os flocos foram analisados quanto às características microbiológicas e ao conteúdo de carotenoides. As crianças estudadas receberam diariamente 6g do produto no almoço, durante 90 dias. Elas foram submetidas ao teste de resposta relativa à dose no início e no final do estudo. Amostras de sangue foram colhidas em jejum, para análise do retinol sérico por espectro-fotometria, no início do estudo, aos 30 dias de consumo e aos 90 dias. RESULTADOS: Quanto às análises microbiológicas, os flocos encontravam-se adequados para consumo. O nível médio de retinol sérico nas crianças aumentou de M=1,438, DP=0,45µmol/L (tempo 0 para M=1,659, DP=0,51µmol/L (30 dias e M=1,928, DP=0,70µmol/L (90 dias. No início do estudo, 18,5% das crianças apresentavam níveis de retinol sérico abaixo do ponto de corte de 1,05µmol/L, proporção que caiu para 7,6% depois de 30 dias e para 0% após 90 dias. No final do período de estudo (90 dias nenhuma criança apresentou resposta relativa à dose positiva. CONCLUSÃO: Os flocos de abóbora são eficazes na elevação do retinol sérico e na reserva hepática da vitamina em pré-escolares.

  20. 7 CFR Exhibits A-B to Subpart G... - [Reserved

    Science.gov (United States)

    2010-01-01

    ... PRIMARILY FOR REAL ESTATE PURPOSES RURAL HOUSING LOANS AND GRANTS Rural Housing Site Loan Policies... 7 Agriculture 12 2010-01-01 2010-01-01 false A Exhibits A-B to Subpart G to Part 1822 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL...

  1. 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.

  2. 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 tr

  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. Discovery of New Substrates for LuxAB Bacterial Bioluminescence.

    Science.gov (United States)

    Jiang, Tianyu; Wang, Weishan; Wu, Xingkang; Wu, Wenxiao; Bai, Haixiu; Ma, Zhao; Shen, Yuemao; Yang, Keqian; Li, Minyong

    2016-08-01

    In this article, four novel substrates with long halftime have been designed and synthesized successfully for luxAB bacterial bioluminescence. After in vitro and in vivo biological evaluation, these molecules can emit obvious bioluminescence emission with known bacterial luciferase, thus indicating a new promising approach to developing the bacterial bioluminescent system. PMID:26896339

  5. 78 FR 33010 - Airworthiness Directives; Saab AB, Saab Aerosystems Airplanes

    Science.gov (United States)

    2013-06-03

    ... in an aircraft maintenance manual is incorrect for Saab 340B airplane. This proposed AD would require... information identified in this proposed AD, contact Saab AB, Saab Aeronautics, SE-581 88, Link ping, Sweden... Aircraft Maintenance Manual (AMM), which quotes an elevator position of 4 degrees trailing edge down...

  6. Discovery of New Substrates for LuxAB Bacterial Bioluminescence.

    Science.gov (United States)

    Jiang, Tianyu; Wang, Weishan; Wu, Xingkang; Wu, Wenxiao; Bai, Haixiu; Ma, Zhao; Shen, Yuemao; Yang, Keqian; Li, Minyong

    2016-08-01

    In this article, four novel substrates with long halftime have been designed and synthesized successfully for luxAB bacterial bioluminescence. After in vitro and in vivo biological evaluation, these molecules can emit obvious bioluminescence emission with known bacterial luciferase, thus indicating a new promising approach to developing the bacterial bioluminescent system.

  7. 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...

  8. 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 are fo...

  9. Relaxation of Small Molecules: an ab initio Study

    Institute of Scientific and Technical Information of China (English)

    CAO Yi-Gang; JIAO Zheng-Kuan; A. Antons; K. Schroeder; S. Blügel2

    2002-01-01

    Using an ab initio total energy and force method, we have relaxed several group IV and group V elementalclusters, in detail the arsenic and antimony dimers, silicon, phosphorus, arsenic and antimony tetramers. The obtainedbond lengths and cohesive energies are more accurate than other calculating methods, and in excellent agreement withthe experimental results.

  10. Relaxation of Small Molecules:an ab initio Study

    Institute of Scientific and Technical Information of China (English)

    CAOYi-Gang; A.Antons; 等

    2002-01-01

    Using an ab inito total energy and force method,we have relaxed several group IV and group V elemental clusters,in detail the arsenic and antimony dimers,silicon,phosphorus,arsenic and antimony tetraners,The obtained bond lengths and cohesive energies are more accurate than other calculating methods,and in excellent agreement with the experimental results.

  11. 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.

  12. AB 1725 Model Accountability System. California Community Colleges. Revised.

    Science.gov (United States)

    California Community Colleges, Sacramento. Board of Governors.

    This report proposes a model accountability system for the California community colleges to comply with the directives of Assembly Bill 1725 (AB 1725). The purpose of the accountability system is to provide colleges and districts, the board of governors, and the California legislature with information that will allow for the continued improvement…

  13. 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.

  14. Estudo sobre reciclagem de lâmpadas fluorescentes

    OpenAIRE

    Danniele Miranda Bacila; Klaus Fischer; Mônica Beatriz Kolicheski

    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...

  15. 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.

  16. ABORDAGENS PARADIGMÁTICAS ALTERNATIVAS: POSSIBILIDADES PARA ESTUDOS EM ADI

    Directory of Open Access Journals (Sweden)

    Christine da Silva Schröeder

    2012-12-01

    Full Text Available Nossa proposta é incentivar a apropriação de abordagens paradigmáticas alternativas para a pesquisa na área de Administração da Informação (ADI, a partir de perspectivas que se contrapõem à ontologia positivista-funcionalista – ou, de outro lado, podem complementá-la, oportunizando a realização de estudos reflexivos, não necessariamente performativos, e “desnaturalizados”. Adotamos os conceitos de reflexividade, não-performatividade e desnaturalização a partir de seu uso por Fournier e Grey (2007, ao referirem-se aos estudos críticos em Administração (ou Critical Management Studies - CMS. Atestamos que os três conceitos nos são valiosos porque nos auxiliam a definir condições pelas quais entendemos que se manifesta pensamento crítico – e, por assim dizer, inspiram a pesquisa multi e interparadigmática. Através das possibilidades deste tipo de pesquisa, podemos lançar olhares potencialmente ampliados sobre a teoria e a prática em Administração da Informação, que trazem implicações não apenas epistemológicas, mas, sobretudo, metodológicas para os estudos da área.

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

    OpenAIRE

    Rodrigo S. Mendes; Thyago A. Gurjão; Souza, Almir P.; Luciana de A. Lacerda; Rosangela M.N. Silva

    2013-01-01

    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 determin...

  18. 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.

  19. Understanding phonon transport in thermoelectric materials using ab initio approaches

    Science.gov (United States)

    Broido, David

    Good thermoelectric materials have low phonon thermal conductivity, kph. Accurate theories to describe kph are important components in developing predictive models of thermoelectric efficiency that can help guide synthesis and measurement efforts. We have developed ab initio approaches to calculate kph, in which phonon modes and phonon scattering rates are computed using interatomic force constants determined from density functional theory, and a full solution of the Boltzmann transport equation for phonons is implemented. A recent approach to calculate interatomic force constants using ab initio molecular dynamics has yielded a good description of the thermal properties of Bi2Te3. But, the complexity of new promising candidate thermoelectric materials introduces computational challenges in assessing their thermal properties. An example is germanane, a germanium based hydrogen-terminated layered semiconductor, which we will discuss in this talk.

  20. Chemical and Electrochemical Metallic Covering of ABS polymers

    Directory of Open Access Journals (Sweden)

    Florentina Cziple

    2009-10-01

    Full Text Available The aim of this paper is the deposition of metallic layers on the surface of ABS plastic material, by means of two consecutive procedures, namely: the first is represented by the conductibility through chemical or electro-chemical metallic covering of the polymeric support and the second procedure is the electrodeposition of the metal through galvanization. The chemical mehtod consists in the submission of ABS polymers to some conductibility operations of the plastic material surface through chemical copper plating (chemical roughing, degreasing with ultra-sounds, chemical sensitivation, activation and proper conductibility of the material surface. The electrochemical deposition of nickel was made on the plastic material activated in the mixture solution of graphite with potassium carbonate.

  1. The density matrix renormalization group for ab initio quantum chemistry

    CERN Document Server

    Wouters, Sebastian

    2014-01-01

    During the past 15 years, the density matrix renormalization group (DMRG) has become increasingly important for ab initio quantum chemistry. Its underlying wavefunction ansatz, the matrix product state (MPS), is a low-rank decomposition of the full configuration interaction tensor. The virtual dimension of the MPS, the rank of the decomposition, controls the size of the corner of the many-body Hilbert space that can be reached with the ansatz. This parameter can be systematically increased until numerical convergence is reached. The MPS ansatz naturally captures exponentially decaying correlation functions. Therefore DMRG works extremely well for noncritical one-dimensional systems. The active orbital spaces in quantum chemistry are however often far from one-dimensional, and relatively large virtual dimensions are required to use DMRG for ab initio quantum chemistry (QC-DMRG). The QC-DMRG algorithm, its computational cost, and its properties are discussed. Two important aspects to reduce the computational co...

  2. Toward the Ab-initio Description of Medium Mass Nuclei

    CERN Document Server

    Barbieri, C; Soma, V; Duguet, T; Navratil, P

    2012-01-01

    As ab-initio calculations of atomic nuclei enter the A=40-100 mass range, a great challenge is how to approach the vast majority of open-shell (degenerate) isotopes. We add realistic three-nucleon interactions to the state of the art many-body Green's function theory of closed-shells, and find that physics of neutron driplines is reproduced with very good quality. Further, we introduce the Gorkov formalism to extend ab-initio theory to semi-magic, fully open-shell, isotopes. Proof-of-principle calculations for Ca-44 and Ni-74 confirm that this approach is indeed feasible. Combining these two advances (open-shells and three-nucleon interactions) requires longer, technical, work but it is otherwise within reach.

  3. Ab-initio calculations on melting of thorium

    Science.gov (United States)

    Mukherjee, D.; Sahoo, B. D.; Joshi, K. D.; Kaushik, T. C.; Gupta, Satish C.

    2016-05-01

    Ab-initio molecular dynamics study has been performed on face centered cubic structured thorium to determine its melting temperature at room pressure. The ion-electron interaction potential energy calculated as a function of temperature for three volumes (a0)3 and (1.02a0)3 and (1.04a0)3 increases gradually with temperature and undergoes a sharp jump at ~2200 K, ~2100 K and ~1800 K, respectively. Here, a0 = 5.043 Å is the equilibrium lattice parameter at 0 K obtained from ab-initio calculations. These jumps in interaction energy are treated as due to the onset of melting and corresponding temperatures as melting point. The melting point of 2100 K is close to the experimental value of 2023K. Further, the same has been verified by plotting the atomic arrangement evolved at various temperatures and corresponding pair correlation functions.

  4. Serine Proteases an Ab Initio Molecular Dynamics Study

    CERN Document Server

    De Santis, L

    1999-01-01

    In serine proteases (SP's), the H-bond between His-57 and Asp-102, and that between Gly-193 and the transition state intermediate play a crucial role for enzymatic function. To shed light on the nature of these interactions, we have carried out ab initio molecular dynamics simulations on complexes representing adducts between the reaction intermediate and elastase (one protein belonging to the SP family). Our calculations indicate the presence of a low--barrier H-bond between His-57 and Asp-102, in complete agreement with NMR experiments on enzyme--transition state analog complexes. Comparison with an ab initio molecular dynamics simulation on a model of the substrate--enzyme adduct indicates that the Gly-193--induced strong stabilization of the intermediate is accomplished by charge/dipole interactions and not by H-bonding as previously suggested. Inclusion of the protein electric field in the calculations does not affect significantly the charge distribution.

  5. The density matrix renormalization group for ab initio quantum chemistry

    OpenAIRE

    Wouters, Sebastian

    2015-01-01

    During the past 15 years, the density matrix renormalization group (DMRG) has become increasingly important for ab initio quantum chemistry. It is used as a numerically exact solver for highly correlated regions in molecules. While the method works extremely well for one-dimensional systems, the correlated regions of interest are often far from one-dimensional. In this introductory talk, I will discuss the DMRG algorithm from a quantum information perspective, how quantum information theory h...

  6. Molexpl: a tool for ab initio data exploration and visualization

    OpenAIRE

    Wang, Xueying; Onofrio, Nicolas,; Strachan, Alejandro

    2015-01-01

    Density functional theory (DFT) based on ab initio theory, is a powerful method to resolve the electronic structure of atoms, molecules and solids. However, in practical, DFT is limited to few hundreds of atoms. To overcome this limitation, researchers have developed empirical interatomic potentials implemented in molecular dynamics (MD) simulations. MD ignores the movements of electrons and describes bonding and non-bonding interaction as a function of the distance between atoms called force...

  7. Ab initio calculation of tight-binding parameters

    Energy Technology Data Exchange (ETDEWEB)

    McMahan, A.K.; Klepeis, J.E.

    1997-12-01

    We calculate ab initio values of tight-binding parameters for the f- electron metal Ce and various phases of Si, from local-density functional one-electron Hamiltonian and overlap matrix elements. Our approach allows us to unambiguously test the validity of the common minimal basis and two-center approximations as well as to determine the degree of transferability of both nonorthogonal and orthogonal hopping parameters in the cases considered.

  8. 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...

  9. Integrated Design of Antibodies for Systems Biology Using Ab Designer

    OpenAIRE

    Pisitkun, Trairak; Dummer, Patrick; Somparn, Poorichaya; Hirankarn, Nattiya; Kopp, Jeffrey B.; Knepper, Mark A.

    2014-01-01

    In the current era of large-scale biology, systems biology has evolved as a powerful approach to identify complex interactions within biological systems. In addition to high throughput identification and quantification techniques, methods based on high-quality mono-specific antibodies remain an essential element of the approach. To assist the large-scale design and production of peptide-directed antibodies for systems biology studies, we developed a fully integrated online application, AbDesi...

  10. GAUSSIAN 76: an ab initio molecular orbital program

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-06-01

    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.

  11. P-V Relation for Mercuric Calcogenides: Ab Initio Method

    OpenAIRE

    G. Misra; S. Tenguria; Gautam, M.

    2011-01-01

    Mercuric Calcogenides found many applications in electronic and optical devices as semiconducting materials. An equation of state provides useful information about the relationship between pressure (P), volume (V) and temperature (T) that helps to understand the behaviour of materials under the effect of high pressure and high temperature. The present paper sheds light on the electronic structure of Mercuric Calcogenides by simulating its electronic properties through ab initio method. This a...

  12. Preparation of F(ab')2 fragments of immunoglobulin G.

    Science.gov (United States)

    Killion, J J; Holtgrewe, E M

    1983-11-01

    We describe a simple protocol for the preparation of F(ab')2 fragments of immunoglobulin G, based upon the known Fc- binding properties of protein A-Sepharose. The fragment preparations of xenogeneic and allogeneic anti-IgG were noncytotoxic to intact target cells, and were able to block the cytotoxicity of intact antibody. This method should therefore be useful for functional studies not requiring biochemical homogeneity.

  13. Ab-initio calculations for dilute magnetic semiconductors

    OpenAIRE

    Belhadji, Brahim

    2008-01-01

    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 approximatio...

  14. Thermochemical data for CVD modeling from ab initio calculations

    Energy Technology Data Exchange (ETDEWEB)

    Ho, P. [Sandia National Labs., Albuquerque, NM (United States); Melius, C.F. [Sandia National Labs., Livermore, CA (United States)

    1993-12-31

    Ab initio electronic-structure calculations are combined with empirical bond-additivity corrections to yield thermochemical properties of gas-phase molecules. A self-consistent set of heats of formation for molecules in the Si-H, Si-H-Cl, Si-H-F, Si-N-H and Si-N-H-F systems is presented, along with preliminary values for some Si-O-C-H species.

  15. Near Resonant Electronic and Rotational Energy Transfer AB(1П, J) + C(slj) → AB(1П, J') + C(slj')

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-Li; SONG Peng; SHEN Yang; MA Feng-Cai

    2005-01-01

    In our previous theoretical study, the theoretical model of the collision-induced electronic and rotational energy transfer of AB(1∑, J) + C(slj) → AB(1∑, J') + C(slj') was presented. To further study the collision-induced electronic and rotational energy transfer theoretically on AB(1∏,J)+C(slj)→AB(1∏,J1)+C(slj') a theoretical model is presented, based on the time-dependent first-order Born approximation, taking into account the anisotropic LennardJones interaction potential and "straight-line" trajectory approximation. The changing tendency of the transitional probabilities with the anisotropic parameter is discussed.

  16. 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.

  17. 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).

  18. A highly accurate ab initio potential energy surface for methane

    Science.gov (United States)

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

    2016-09-01

    A new nine-dimensional potential energy surface (PES) for methane has been generated using state-of-the-art ab initio theory. The PES is based on explicitly correlated coupled cluster calculations with extrapolation to the complete basis set limit and incorporates a range of higher-level additive energy corrections. These include core-valence electron correlation, higher-order coupled cluster terms beyond perturbative triples, scalar relativistic effects, and the diagonal Born-Oppenheimer correction. Sub-wavenumber accuracy is achieved for the majority of experimentally known vibrational energy levels with the four fundamentals of 12CH4 reproduced with a root-mean-square error of 0.70 cm-1. The computed ab initio equilibrium C-H bond length is in excellent agreement with previous values despite pure rotational energies displaying minor systematic errors as J (rotational excitation) increases. It is shown that these errors can be significantly reduced by adjusting the equilibrium geometry. The PES represents the most accurate ab initio surface to date and will serve as a good starting point for empirical refinement.

  19. Acceleration of the Convergence in ab initio Atomic Relaxations

    Science.gov (United States)

    Zhao, Zhengji; Wang, Lin-Wang; Meza, Juan

    2006-03-01

    Atomic relaxations is often required to accurately describe the properties of nanosystems. In ab initio calculations, a common practice is to use a standard search algorithm, such as BFGS (Broyden-Fletcher-Goldfarb-Shanno) or CG (conjugate gradient) method, which starts the atomic relaxations without any knowledge of the Hessian matrix of the system. For example, the initial Hessian in BFGS method is often set to identity, and there is no preconditioning to CG method. One way to accelerate the convergence of the atomic relaxations is to estimate an approximate Hessian matrix of the system and then use it as the initial Hessian in BFGS method or a preconditioner in CG method. Previous attempts to obtain the approximated Hessian were focused on the use of classical force field models which rely on the existence of good parameters. Here, we present an alternative method to estimate the Hessian matrix of a nanosystem. First, we decompose the system into motifs which consist of a few atoms, then calculate the Hessian matrix elements on different motif types from ab initio calculations for small prototype systems. Then we generate the Hessian Matrix of the whole system by putting together these motif Hessians. We have applied our motif-based Hessian matrix in ab initio atomic relaxations in several bulk (with/without impurity) and quantum dot systems, and have found a speed up factor of 2 to 4 depending on the system size.

  20. Studies on the runaway reaction of ABS polymerization process

    Energy Technology Data Exchange (ETDEWEB)

    Hu, K.-H. [Department of Occupational Safety and Health, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan (China); Kao, C.-S. [Department of Safety, Health and Environmental Engineering, National United University, Taiwan (China); Duh, Y.-S. [Department of Occupational Safety and Health, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan (China)], E-mail: yihshingduh@yahoo.com.tw

    2008-11-15

    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.

  1. Converting of Matter to Nuclear Energy by AB-Generator

    Directory of Open Access Journals (Sweden)

    Alexander Bolonkin

    2009-01-01

    Full Text Available Problem statement: Researcher offered a new nuclear generator which allowed to convert any matter to nuclear energy in accordance with Einstein equation E = mc2. The method was based upon tapping the energy potential of a Micro Black Hole (MBH and Hawking radiation created by this MBH. Researcher did not meet the idea and its research in literature to develop the method for getting a cheap energy. Approach: As is well-known, vacuum continuously produced virtual pairs of particles and antiparticles, in particular, photons and anti-photons. MBH event horizon allowed separating them. Anti-photons can be moved to MBH and be annihilated, decreasing mass of MBH, resulting photons leave the MBH neighborhood as Hawking radiation. The offered nuclear generator (named by Researcher as AB-generator utilized Hawking radiation and injected the matter into MBH and kept MBH in a stable state with near-constant mass. Results: AB-generator can be produced gigantic energy outputs and should be cheaper than a conventional electric station by a factor of hundreds of times. One also may be used in aerospace as a photon rocket or as a power source for many vehicles. Conclusion: Many scientists expect Large Hadron Collider at CERN may be produced one MBH every second. A technology to capture them may be developed; than they may be used for the AB-generator.

  2. 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...

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

    Science.gov (United States)

    Makhov, Dmitry V.; Glover, William J.; Martinez, Todd J.; Shalashilin, Dmitrii V.

    2014-08-01

    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.

  4. 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.

  5. A Complete and Accurate Ab Initio Repeat Finding Algorithm.

    Science.gov (United States)

    Lian, Shuaibin; Chen, Xinwu; Wang, Peng; Zhang, Xiaoli; Dai, Xianhua

    2016-03-01

    It has become clear that repetitive sequences have played multiple roles in eukaryotic genome evolution including increasing genetic diversity through mutation, changes in gene expression and facilitating generation of novel genes. However, identification of repetitive elements can be difficult in the ab initio manner. Currently, some classical ab initio tools of finding repeats have already presented and compared. The completeness and accuracy of detecting repeats of them are little pool. To this end, we proposed a new ab initio repeat finding tool, named HashRepeatFinder, which is based on hash index and word counting. Furthermore, we assessed the performances of HashRepeatFinder with other two famous tools, such as RepeatScout and Repeatfinder, in human genome data hg19. The results indicated the following three conclusions: (1) The completeness of HashRepeatFinder is the best one among these three compared tools in almost all chromosomes, especially in chr9 (8 times of RepeatScout, 10 times of Repeatfinder); (2) in terms of detecting large repeats, HashRepeatFinder also performed best in all chromosomes, especially in chr3 (24 times of RepeatScout and 250 times of Repeatfinder) and chr19 (12 times of RepeatScout and 60 times of Repeatfinder); (3) in terms of accuracy, HashRepeatFinder can merge the abundant repeats with high accuracy. PMID:26272474

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

    International Nuclear Information System (INIS)

    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 1010 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.

  7. A Influência da Responsabilidade Social Corporativa na Imagem de Marca: Um Estudo em Empresas Brasileiras do Setor de Cosméticos

    Directory of Open Access Journals (Sweden)

    Márcio Ribeiro da Fonseca

    2014-12-01

    Full Text Available 800x600 Este estudo tem como tema a influência da Responsabilidade Social Corporativa (RSC na imagem de marca (IM e na reputação corporativa (RC de empresas brasileiras do setor de cosméticos. O foco da pesquisa foi investigar a percepção dos consumidores universitários pertencentes às classes A/B sobre as ações de RSC de duas grandes empresas brasileiras de cosméticos. O objetivo foi comparar as percepções dos consumidores e apontar as diferenças entre as duas empresas. O desenvolvimento deste estudo ocorreu em duas etapas: a primeira etapa envolveu revisão bibliográfica, verificando as teorias e pesquisas publicadas sobre responsabilidade social corporativa, IM e RC. A segunda etapa envolveu a coleta de dados por meio de uma survey com consumidores de duas grandes empresas brasileiras de cosméticos que publicam relatórios sociais com metodologia GRI. Os resultados demonstraram que a RSC tem influência positiva na IM, porém tal influência demonstrou-se significativa apenas para uma das marcas estudadas, sendo moderada para a segunda. Entre as contribuições deste trabalho estão a revisão de literatura sobre o tema, os apontamentos da influência dos subconstrutos e variáveis da RSC na IM e RC e as diferenças da percepção do consumidor para cada uma das marcas estudadas, bem como as recomendações para estudos futuros. Normal 0 21 false false false PT-BR X-NONE X-NONE MicrosoftInternetExplorer4 TENDÊNCIAS DOS ESTUDOS COM PLANTAS MEDICINAIS NO BRASIL

    Directory of Open Access Journals (Sweden)

    Fernanda Melo Carneiro

    2014-12-01

    Full Text Available As plantas medicinais são utilizadas pelo homem desde o início da história e atualmente empregadas como recursos na medicina alternativa por grande parte da população mundial. Esse uso deve-se à facilidade de acesso às plantas em relação aos medicamentos alopáticos. O objetivo deste trabalho foi, primariamente, desenvolver uma análise cienciométrica sobre as tendências dos estudos com plantas medicinais no Brasil, investigando se o número de trabalhos cresceu ao longo dos anos. Além disso, foi identificamos as principais plantas que são estudadas pelo seu principio medicinal no Brasil. Para a pesquisa foi empregada a base de dados Scielo, com artigos de 1995 a 2011, utilizando a palavra “Planta Medicinal” como palavra-chave. Foram avaliados 329 artigos, mas somente 265 foram compatíveis à pesquisa. Artigos que não foram desenvolvidos no Brasil; que não utilizaram o termo planta medicinal; ou não citaram plantas foram excluídos das análises. Em cada artigo selecionado foram coletadas as seguintes informações: título do artigo, quantidade de autores, instituições responsáveis pelo estudo, local das instituições, ano de publicação, tipo de estudo (ex.: farmacológico, agropecuário e ecológico e as plantas que foram estudadas. Por meio de análises desses dados foi possível verificar as tendências dos estudos com plantas medicinais no Brasil. Conforme esperado, a maior parte dos artigos avaliados estão voltados para a Farmacologia, com aplicação em diversas áreas da saúde e em segundo lugar a Agropecuária, devido ao interesse em desenvolver produtos a partir de plantas para o controle de pragas. Entretanto, verificou-se o emprego em outras áreas, como a Bioquímica, Botânica, Ecologia, Genética/Molecular e Educação que apesar de serem menos frequentes, são essenciais, pois os estudos com plantas medicinais requerem profissionais de múltiplas áreas. Além da investigação da medicina popular

  8. 高吸水性树脂丙烯酰胺-丙烯酸-对苯乙烯磺酸钠三元共聚物的合成%Synthesis of super absorbent resin acrylamide - acrylic acid - sodium p - styrene sulfonate terpolymer

    Institute of Scientific and Technical Information of China (English)

    余巧玲; 杨燕; 张杰

    2012-01-01

    以丙烯酰胺(AM)、丙烯酸(AA)和对苯乙烯磺酸钠(SSS)为单体,过硫酸钾为引发剂,N,N'-亚甲基双丙烯酰胺为交联剂,采用溶液聚合法制备出AM - AA - SSS三元共聚物.结果表明,聚合最佳条件为:AA用量10 mL,AM用量3.3g,SSS用量0.5 g,引发剂用量0.040 g,交联剂用量0.010 g,反应温度60℃.在此条件下,试样的吸蒸馏水倍率为259g/g,吸盐水倍率为42 g/g.%Aciylamide (AM) - acrylic acid (AA) - sodium p - styrene sulfonate ( SSS) terpoly-mer was synthesized by solution polymerization with AM,AA and SSS as monomers,potassium persulfate as initiator, N, N' - methylene bisacrylamide as crosslinking agent. The results showed that the optimum synthetic conditions were AA 10 mL, AM 3.3 g, SSS 0.5 g, initiator 0.040 g, crosslinkingagent 0.010 g, reaction temperature 60 °C . Under these conditions, the water absorption rate of the polymer was 259 g/g,the salt water absorption rate of the polymer was 42 g/g.

  9. Tenacificação do poli(ácido lático pela adição do terpolímero (etileno/acrilato de metila/metacrilato de glicidila Toughening of polylactide by melt blending with an (ethylene/methyl acrylate/glycidyl methacrylate terpolymer

    Directory of Open Access Journals (Sweden)

    Gustavo F. Brito

    2012-01-01

    Full Text Available O poli(ácido lático é um polímero biodegradável proveniente de fontes renováveis com grande potencial para substituir polímeros não biodegradáveis provenientes do petróleo. Entretanto, seu uso em determinadas aplicações é restringido devido a sua elevada fragilidade e rigidez. Com o intuito de tornar o PLA mais tenaz, o terpolímero (etileno/acrilato de metila/metacrilato de glicidila -EMA-GMA foi adicionado ao PLA em diferentes concentrações. A adição do EMA-GMA tornou o PLA mais estável durante o processamento. Por FTIR comprovou-se a existência de reação química entre os grupos terminais do PLA e grupos do EMA-GMA. A partir dos ensaios mecânicos observou-se uma resistência ao impacto três vezes superior à do PLA puro.The Poly(lactic acid is a biodegradable polymer from renewable sources with potential to replace non-biodegradable polymers derived from petroleum. However its use is restricted in certain applications due to its high brittleness and rigidity. In order to make the PLA more tenacious, the terpolymer (ethylene/methyl acrylate/glycidyl methacrylate - EMA-GMA was added to PLA in different concentrations. The addition of EMA-GMA to PLA turned the blends more stable during processing. The FTIR data confirmed the chemical reaction between groups in PLA and the EMA-GMA. A three fold increase was observed in the impact strength compared to pure PLA.

  10. 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.

  11. A ProActive Backend for ABS: from Modelling to Deployment

    OpenAIRE

    Rochas, Justine; Henrio, Ludovic

    2014-01-01

    ABS is an object-oriented modeling language that is based on a concurrent object group model, derived itself from the active object model. Its goal is to describe distributed and concurrent applications in order to verify their properties and make them safer. Thanks to the ABS Tool Suite, ABS programs can be translated into the Java programming language (among others), and executed in the JVM. This paper presents a new ABS backend that translates ABS programs into ProActive programs. ProActiv...

  12. TENDÊNCIAS DOS ESTUDOS COM PLANTAS MEDICINAIS NO BRASIL

    OpenAIRE

    Fernanda Melo Carneiro; Maria José Pereira da Silva; Leonardo Luiz Borges; Lorena Carneiro Albernaz,; Joana Darc Pereira Costa

    2014-01-01

    As plantas medicinais são utilizadas pelo homem desde o início da história e atualmente empregadas como recursos na medicina alternativa por grande parte da população mundial. Esse uso deve-se à facilidade de acesso às plantas em relação aos medicamentos alopáticos. O objetivo deste trabalho foi, primariamente, desenvolver uma análise cienciométrica sobre as tendências dos estudos com plantas medicinais no Brasil, investigando se o número de trabalhos cresceu ao longo dos anos. Além disso, f...

  13. Eletrocardiografia computadorizada em cães: estudo comparativo

    OpenAIRE

    Lídia S. Oliveira; Roberto R.B. Santos; Melo, Marcos B; Daniela F. Larangeira; Stella Maria Barrouin-Melo

    2013-01-01

    O método de eletrocardiografia computadorizada (ECG-C) vem sendo crescentemente difundido na medicina veterinária, havendo atualmente diversas marcas e modelos de eletrocardiógrafos disponíveis no mercado. Diante da possibilidade de diferenças na sensibilidade e na reprodutibilidade das medidas obtidas nos traçados, o presente estudo teve como objetivo comparar os parâmetros eletrocardiográficos de cães, obtidos por dois sistemas. Foram avaliados dois diferentes softwares computadorizados, o ...

  14. Criatividade e gastronomia: Um estudo exploratório

    OpenAIRE

    Ferreira, Ana Catarina

    2012-01-01

    O presente trabalho é um estudo exploratório que aborda o tema da criatividade na gastronomia, sendo um tema pioneiro e pouco trabalhado. Na teoria, a gastronomia tem um grande significado afectivo e identitário (seja a nível cultural ou a nível individual) e é uma área que acompanha o desenvolvimento das sociedades. Por outro lado, a criatividade demonstra-se como sendo uma prática complexa de processos e dinâmicas mentais, também implicando muito da identidade e da personalidade do sujeito ...

  15. Estudo para uma mobilidade flutuante na Ria de Aveiro

    OpenAIRE

    Gaspar, Licínia

    2012-01-01

    O presente estudo desenvolve uma estratégia orientada à criação de um novo sistema de mobilidade fluvial que promove a Ria de Aveiro, no sentido de ampliar a mobilidade na Ria, bem como reafirmar a natureza desse território, proporcionando o conhecimento de uma vasta área lagunar. Numa análise à mobilidade fluvial em Aveiro, que foi suporte para o crescimento e desenvolvimento da cidade, constatou-se a ausência de uma mobilidade diversificada assente na oferta de um serviço ...

  16. Marketing digital : um estudo das empresas em Angola

    OpenAIRE

    Guerra, Dalva Marina Teixeira

    2013-01-01

    Dissertação de mestrado em Estudos de Gestão Com a introdução das novas tecnologias e da Internet, os mercados têm evoluído cada vez mais. Os consumidores tornam-se cada vez mais exigentes, por sentirem que mais facilmente podem comparar, comprar e reclamar através desta ferramenta. Por este motivo, as empresas procuram cada vez mais superar-se e oferecer produtos e serviços diferenciados ao cliente, de forma a ganhar vantagem competitiva num mercado cada vez mais competitiv...

  17. "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...

  18. Responsabilidade Social Corporativa: estudo comparativo das normas socioambientais

    OpenAIRE

    Francisco Roberto Pinto; Dorelland Ponte Lima; Marcelle Colares Oliveira; Leonel Gois Lima Oliveira

    2007-01-01

    A utilização de normas socioambientais visa dar maior credibilidade às práticas de Responsabilidade Social Corporativa (RSC). Neste estudo, levantaram-se os seguintes questionamentos: Quais as características das normas socioambientais existentes quanto à avaliação do processo produtivo, das relações com a comunidade, das relações com os empregados e dependentes? Quais os aspectos convergentes e divergentes dessas características no tocante à integração dos sistemas de gestão da RSC propugnad...

  19. COMPORTAMENTO DE CONSUMO ECOLOGICAMENTE CONSCIENTE: ESTUDO COMPARATIVO BRASIL X CHINA

    OpenAIRE

    Tatiana Azevedo Yeh; Jailer Aguiar Lage

    2015-01-01

    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 ...

  1. Compatibilização de blendas de poliamida 6/ABS usando os copolímeros acrílicos reativos MMA-GMA e MMA-MA. Parte 1: Comportamento reológico e propriedades mecânicas das blendas Compatibilization of polyamide 6/ABS blends using MMA-GMA and MMA-MA reactive acrylic copolymers. Part 1. Rheological and mechanical properties of blends

    Directory of Open Access Journals (Sweden)

    Edcleide M. Araújo

    2003-07-01

    Full Text Available A poliamida 6 (PA6 é um polímero semicristalino de grande aplicação na engenharia e que apresenta instabilidade no processamento e baixa resistência ao impacto sob entalhe. A incorporação do ABS (acrilonitrila-butadieno-estireno como modificador de impacto da PA6, pode melhorar estas propriedades. Entretanto, como esta mistura é imiscível e incompatível, torna-se necessária a incorporação de um terceiro componente que promova a interação destas duas fases imiscíveis. Este estudo analisa a influência dos copolímeros MMA-GMA (metacrilato de metila-metacrilato de glicidila e MMA-MA (metacrilato de metila-anidrido maléico como compatibilizantes de blendas PA6/ABS. Estes copolímeros apresentam miscibilidade com a fase SAN do ABS, devido à presença do PMMA, e têm também os grupos funcionais éster e anidrido capazes de reagir com os grupos terminais, presentes na PA6. As blendas PA6/ABS/MMA-MA apresentaram excelente desempenho sob impacto, permanecendo dúcteis em temperaturas subambiente e super-tenazes na temperatura ambiente.Polyamide 6 (PA6 is a semicrystalline polymer suitable to be used in engineering applications with a number of advantages, but its processing instability and relatively low impact strength are limiting aspects. The addition of acrylonitrile-butadiene-styrene (ABS as an impact modifier to PA6 can improve these properties. However, this blend is immiscible and incompatible, hence the use of an adhesion promoter is necessary to improve the interfacial interaction between the phases. This study focuses on the influence of poly(methyl methacrylate-co-glycidyl methacrylate (MMA-GMA and poly(methyl methacrylate-co-maleic anhydride (MMA-MA copolymers as compatibilizers for PA6/ABS blends. These copolymers are miscible with SAN phase of ABS due to the presence of PMMA and they have also the esther and anhydride functional groups capable of reacting with polyamide end groups. PA6/ABS/MMA-MA blends showed an

  2. Marketing, Propaganda e Publicidade - um estudo dos termos no Brasil

    Directory of Open Access Journals (Sweden)

    Miguel Arantes Normanha Filho

    2007-12-01

    Full Text Available Este estudo contribui para a verificação empírica das diversas interpretações e aplicabilidades dadas aos pares de termos marketing e propaganda, propaganda e publicidade, em especial pela forma e uso como se fossem sinônimos, num contexto de negócios que pode acarretar prejuízos às empresas. O estudo parte da observação de que utilizar marketing e propaganda como sinônimos não é uma questão semântica, mas conceitual, em que a aplicação de uma ferramenta [propaganda] específica, em detrimento de uma filosofia do negócio [marketing], leva empresários [decisores] a equívocos estratégicos, que influenciam e comprometem o capital de giro e, conseqüentemente, a saúde econômico-financeira da empresa.

  3. Paleoparasitologia. Estudo de parásitos em material arqueologico

    Directory of Open Access Journals (Sweden)

    Adauto de Araújo

    2005-12-01

    Full Text Available Os primeiros estudos sobre parasitos em material arqueológico datam do início do século XX, feitos por Sir. Marc Armand Ruffer, médico e microbiologista de origem francesa a serviço em um hospital do Cairo. Nas horas vagas, dedicou-se ao estudo de lesões patológicas em múmias egípcias, assim, pode descrever diversas doenças, entre elas a esquistossomíase hematóbica, pela evidência de ovos de Schistosoma haematobium em cortes histológicos de tecido renal de múmias datadas de até 5.200 anos. Coube a Ruffer a introdução da técnica de reidratação de tecidos mumificados, capaz de permitir o uso de exames histopatológicos, usada até a atualidade.

  4. Para um estudo psicológico das virtudes morais

    Directory of Open Access Journals (Sweden)

    La Taille Yves de

    2000-01-01

    Full Text Available O propósito deste artigo é defender a importância de estudos psicológicos das virtudes morais (como generosidade, coragem, humildade, fidelidade etc.. Tal defesa é realizada de várias formas. Do ponto de vista filosófico, o tema das virtudes não somente é clássico (Ver Aristóteles, por exemplo como tem sido rediscutido por autores contemporâneos descontentes com as limitações da ética moderna, em geral baseada no conceito de direito. Do ponto de vista psicológico, o autor defende a idéia segundo a qual as virtudes morais não somente participam da gênese da moralidade, como representam traços de caráter essenciais à coesão da personalidade moral. Tal perspectiva está, de certa forma, anunciada na obra de Piaget sobre o juízo moral, como em autores outros como Tugendhat. Ela está também presente nos estudos sobre a relação entre o sentimento de vergonha e a ética. Finalmente, aponta-se que, no que se refere à educação moral, as virtudes podem representar um tema rico e sugestivo para a reflexão das crianças e adolescentes.

  5. Responsabilidade Social Corporativa: estudo comparativo das normas socioambientais

    Directory of Open Access Journals (Sweden)

    Francisco Roberto Pinto

    2007-05-01

    Full Text Available A utilização de normas socioambientais visa dar maior credibilidade às práticas de Responsabilidade Social Corporativa (RSC. Neste estudo, levantaram-se os seguintes questionamentos: Quais as características das normas socioambientais existentes quanto à avaliação do processo produtivo, das relações com a comunidade, das relações com os empregados e dependentes? Quais os aspectos convergentes e divergentes dessas características no tocante à integração dos sistemas de gestão da RSC propugnados nas normas socioambientais? Trata-se de um estudo exploratório, com abordagem qualitativa, em que se realizou pesquisa bibliográfica e documental, e análise comparativa do conteúdo dos documentos pesquisados. As normas estudadas foram SA 8000, AA 1000, ISO 14001, NBR 16001 e ISO 26000, esta ainda em fase de elaboração. Concluiu-se que as normas apresentam semelhanças quanto ao processo produtivo, relação com a comunidade e integração dos sistemas de gestão, sendo recomendável a aplicação complementar das mesmas.

  6. 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.

  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...

  8. 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.

  9. GQ Lup Ab Visible & Near-Infrared Photometric Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Marois, C; Macintosh, B; Barman, T

    2006-08-07

    We have re-analyzed archival HST R and I band images and Subaru CH{sub 4}, H, Ks and L{prime} data of the recently discovered planetary mass companion (PMC) GQ Lup Ab. With these we produce the first R and I band photometry of the companion and fit a radius and effective temperature using detailed model atmospheres. We find an effective temperature of 2338 {+-} 100K, and a radius of 0.37 {+-} 0.05R{sub {circle_dot}} and luminosity of log(L/L{sub {circle_dot}}) = -2.43 {+-} 0.07 (at 140pc). Since we fit wavelengths that span most of the emitted radiation from GQ Lup this luminosity estimate is robust, with uncertainty dominated by the distance uncertainty. The radius obtained for 140pc (0.37R{sub {circle_dot}}) is significantly larger than the one originally derived. The mass of the object is much more model-dependent than the radiative properties, but for the GAIA dusty models we find a mass between 9-20 M{sub Jup}, in the range of the brown dwarf and PMC deuterium burning boundary. Assuming a distance of 140pc, observations fit to 1{sigma} the Baraffe evolution model for a {approx} 15 M{sub Jup} brown dwarf. Additionally, the F606W photometric band is significantly overluminous compared to model predictions. Such overluminosity could be explained by a bright H{alpha} emission from chromospheric activity, interaction with another undetected companion, or accretion. Assuming that GQ Lup Ab has a bright H{alpha} emission line, its H{alpha} emission strength is 10{sup -1.71 {+-} 0.10} L{sub bol}, significantly larger than field late-type dwarfs. GQ Lup Ab might be strongly accreting and still be in its formation phase.

  10. Ab initio structure determination via powder X-ray diffraction

    Indian Academy of Sciences (India)

    Digamber G Porob; T N Guru Row

    2001-10-01

    Structure determination by powder X-ray diffraction data has gone through a recent surge since it has become important to get to the structural information of materials which do not yield good quality single crystals. Although the method of structure completion when once the starting model is provided is facile through the Rietveld refinement technique, the structure solution ab initio os still not push-button technology. In this article a survey of the recent development in this area is provided with an illustration of the structure determination of -NaBi3V2O10.

  11. Electrostriction coefficient of ferroelectric materials from ab initio computation

    Directory of Open Access Journals (Sweden)

    Z. Jiang

    2016-06-01

    Full Text Available Electrostriction is an important material property that characterizes how strain changes with the development of polarization inside a material. We show that ab initio techniques developed in recent years can be exploited to compute and understand electrostriction of ferroelectric materials. Here, electrostriction coefficients of ferroelectric BaTiO3, PbTiO3, as well as dielectric BaZrO3, are obtained and analyzed. Possible causes of the difference between experimental and numerical results are discussed. We also identified that relative displacements between certain ions at a given polarization could be a good indicator of a material’s electrostriction property.

  12. 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.

  13. 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.

  14. Ab initio study of neutron drops with chiral Hamiltonians

    Directory of Open Access Journals (Sweden)

    H.D. Potter

    2014-12-01

    Full Text Available We report ab initio calculations for neutron drops in a 10 MeV external harmonic-oscillator trap using chiral nucleon–nucleon plus three-nucleon interactions. We present total binding energies, internal energies, radii and odd–even energy differences for neutron numbers N=2–18 using the no-core shell model with and without importance truncation. Furthermore, we present total binding energies for N=8,16,20,28,40,50 obtained in a coupled-cluster approach. Comparisons with quantum Monte Carlo results, where available, using Argonne v8′ with three-nucleon interactions reveal important dependences on the chosen Hamiltonian.

  15. Accelerating ab initio molecular dynamics simulations by linear prediction methods

    Science.gov (United States)

    Herr, Jonathan D.; Steele, Ryan P.

    2016-09-01

    Acceleration of ab initio molecular dynamics (AIMD) simulations can be reliably achieved by extrapolation of electronic data from previous timesteps. Existing techniques utilize polynomial least-squares regression to fit previous steps' Fock or density matrix elements. In this work, the recursive Burg 'linear prediction' technique is shown to be a viable alternative to polynomial regression, and the extrapolation-predicted Fock matrix elements were three orders of magnitude closer to converged elements. Accelerations of 1.8-3.4× were observed in test systems, and in all cases, linear prediction outperformed polynomial extrapolation. Importantly, these accelerations were achieved without reducing the MD integration timestep.

  16. Equations of state of heavy metals: ab initio approaches

    International Nuclear Information System (INIS)

    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)

  17. 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...... framework for modelling the fusion process of noble gas clusters is presented. We report the striking correspondence of the peaks in the experimentally measured abundance mass spectra with the peaks in the size-dependence of the second derivative of the binding energy per atom calculated for the chain...... of the noble gas clusters up to 150 atoms....

  18. Ab initio Study of He Stability in hcp-Ti

    Institute of Scientific and Technical Information of China (English)

    DAI Yun-Ya; YANG Li; PENG Shu-Ming; LONG Xing-Gui; GAO Fei; ZU Xiao-Tao

    2010-01-01

    @@ The stability of He in hcp-Ti is studied using the ab initio method based on the density functional theory.The results indicate that a single He atom prefers to occupy the tetrahedral site rather than the octahedral site.The interaction of He defects with Ti atoms is employed to explain the relative stabilities of He point defects in hcp-Ti.The relative stability of He defects in hcp-Ti is useful for He clustering and bubble nucleation in metal tritides,which provides the basis for development of improved atomistic models.

  19. Polymeric nitrogen in a graphene matrix: An ab initio study

    Science.gov (United States)

    Timoshevskii, V.; Ji, Wei; Abou-Rachid, Hakima; Lussier, Louis-Simon; Guo, H.

    2009-09-01

    A hybrid material where polymeric nitrogen chains are sandwiched between graphene sheets in the form of a three-dimensional crystal, is predicted by means of ab initio simulations. It is demonstrated that chainlike polymeric nitrogen phase becomes stable at ambient pressure when intercalated in a multilayer graphene matrix. The physical origin of this stabilization is identified by studying the electronic properties of the system. This approach of stabilizing polymeric nitrogen by means of external three-dimensional matrix constitutes a path toward synthesizing different types of nitrogen-based high-energy materials.

  20. Ab-initio study of transition metal hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Ramesh [Dept. of Physics, Feroze Gandhi Insititute of Engineering and Technology, Raebareli-229001 (India); Shukla, Seema, E-mail: sharma.yamini62@gmail.com; Dwivedi, Shalini, E-mail: sharma.yamini62@gmail.com; Sharma, Yamini, E-mail: sharma.yamini62@gmail.com [Theoretical Condensed Matter Physics Laboratory, Dept. of Physics Feroze Gandhi College, Raebareli-229001 (India)

    2014-04-24

    We have performed ab initio self consistent calculations based on Full potential linearized augmented plane wave (FP-LAPW) method to investigate the optical and thermal properties of yttrium hydrides. From the band structure and density of states, the optical absorption spectra and specific heats have been calculated. The band structure of Yttrium metal changes dramatically due to hybridization of Y sp orbitals with H s orbitals and there is a net charge transfer from metal to hydrogen site. The electrical resistivity and specific heats of yttrium hydrides are lowered but the thermal conductivity is slightly enhanced due to increase in scattering from hydrogen sites.

  1. 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......3C2, and Ti6C5) are found to be ground state configurations. Their stability has been verified by full-potential total energy calculations of the fully relaxed structures....

  2. Accelerating Ab Initio Nuclear Physics Calculations with GPUs

    CERN Document Server

    Potter, Hugh; Maris, Pieter; Sosonkina, Masha; Vary, James; Binder, Sven; Calci, Angelo; Langhammer, Joachim; Roth, Robert; Çatalyürek, Ümit; Saule, Erik

    2014-01-01

    This paper describes some applications of GPU acceleration in ab initio nuclear structure calculations. Specifically, we discuss GPU acceleration of the software package MFDn, a parallel nuclear structure eigensolver. We modify the matrix construction stage to run partly on the GPU. On the Titan supercomputer at the Oak Ridge Leadership Computing Facility, this produces a speedup of approximately 2.2x - 2.7x for the matrix construction stage and 1.2x - 1.4x for the entire run.

  3. Pharmacokinetics of radioimmunotherapeutic agent of direct labeling mAb 188Re-HAb18

    Institute of Scientific and Technical Information of China (English)

    Chao Lou; Zhi-Nan Chen; Hui-Jie Bian; Jie Li; Shou-Bo Zhou

    2002-01-01

    AIM: To labed Anti-hepatoma monoclonal antibody (mAb)fragment HAb18 F (ab')2 was labeled with 188 Re for thepharmacokinetic model of 188 Re-HAb18 F (ab')2 and toevaluate its pharmacokinetic parameters in hepatoma-bearing nude mice.METHODS: HAb18 F(ab')2 was directly labeled with 188Reusing 2-mercaptoethanol (2-ME) as reducing agents.Labeling efficiency and immunoreactivity of 188 Re-HAb18 F( ab')2 were evaluated by Whatman 3MM paperchromatography and live cell assay, respectively.Biodiatribution analysis was also conducted in nude micebearing human hepatoma in which animals were sacrificed atdifferent time points(1, 4, 18, 24 and 24h) after 188Re-HAb18F(ab' )2 was injected through tail-vein into hepatoma-bearingnude mice. The blood and radioactivity of organs and masswere measured. The concentrations of 188 Re-HAb18 F(ab')2were evaluated with a pharmacokinetic 3P97 software.RESULTS: The optimum labeling efficiency andimmunoreactive fraction were 91.7% and 0.78%,respectively. The parameters of 188Re-HAb18 F(ab')2 were:T1/2, 2.29h; Vd, 1.49 × 10-9L@ Bq- 1; AUC, 20.49 × 109Bq@ h@L-1 ;CL, 0.45 × 10-3L@ h- 1. 188Re- HAb18 F(ab')2 could locatespecially in hepatoma with high selective reactivity of HAb18F(ab')2. 188 Re-HAb18 F(ab')2 was mainly eliminated bykidney. The maximal tumor to blood ratio was at 48h, andmaximal tumor to liver ratio was at 18h.CONCLUTION: The pharmacokinetics of 188Re-HAb18 F(ab')2fit a I-compartment model. 188 Re-HAb18 F(ab')2 can beuptaken selectively at the hepatoma site.

  4. 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.

  5. 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

  6. Imagem organizacional: um estudo de caso sobre a PUC Minas.

    Directory of Open Access Journals (Sweden)

    Alexandre de Pádua Carrieri

    2008-06-01

    Full Text Available Esta pesquisa propôs conhecer a imagem corporativa, considerando sua importância para a administração das organizações no cenário atual de maior competitividade e de exigências por parte de segmentos do seu público. O estudo parte da formação da cultura e da identidade de uma organização, analisando estes itens como fundamentais na definição da imagem de uma instituição. Tomando a Pontifícia Universidade Católica de Minas Gerais - PUC Minas - 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

  7. Recensão de "Cadernos de estudos latino-americanos nº4"

    OpenAIRE

    Cardoso, João Casqueira

    2010-01-01

    Recensão - TOSCANO, Ana María da Costa, org. - Cadernos de estudos latino-americanos : publicação do CELA, Centro de Estudos Latino-Americanos. Porto: Edições Universidade Fernando Pessoa, 2008. p. 134. ISSN 1646-5164

  8. Electrocatalytic reduction of nitrate and selenate by NapAB.

    Science.gov (United States)

    Gates, Andrew J; Butler, Clive S; Richardson, David J; Butt, Julea N

    2011-01-01

    Bacterial cellular metabolism is renowned for its metabolic diversity and adaptability. However, certain environments present particular challenges. Aerobic metabolism of highly reduced carbon substrates by soil bacteria such as Paracoccus pantotrophus presents one such challenge since it may result in excessive electron delivery to the respiratory redox chain when compared with the availability of terminal oxidant, O2. The level of a periplasmic ubiquinol-dependent nitrate reductase, NAP, is up-regulated in the presence of highly reduced carbon substrates. NAP oxidizes ubiquinol at the periplasmic face of the cytoplasmic membrane and reduces nitrate in the periplasm. Thus its activity counteracts the accumulation of excess reducing equivalents in ubiquinol, thereby maintaining the redox poise of the ubiquinone/ubiquinol pool without contributing to the protonmotive force across the cytoplasmic membrane. Although P. pantotrophus NapAB shows a high level of substrate specificity towards nitrate, the enzyme has also been reported to reduce selenate in spectrophotometric solution assays. This transaction draws on our current knowledge concerning the bacterial respiratory nitrate reductases and extends the application of PFE (protein film electrochemistry) to resolve and quantify the selenate reductase activity of NapAB. PMID:21265780

  9. Ab Initio Protein Structure Prediction Using Pathway Models

    Directory of Open Access Journals (Sweden)

    Christopher Bystroff

    2006-04-01

    Full Text Available Ab initio prediction is the challenging attempt to predict protein structures based only on sequence information and without using templates. It is often divided into two distinct sub-problems: (a the scoring function that can distinguish native, or native-like structures, from non-native ones; and (b the method of searching the conformational space. Currently, there is no reliable scoring function that can always drive a search to the native fold, and there is no general search method that can guarantee a significant sampling of near-natives. Pathway models combine the scoring function and the search. In this short review, we explore some of the ways pathway models are used in folding, in published works since 2001, and present a new pathway model, HMMSTR-CM, that uses a fragment library and a set of nucleation/propagation-based rules. The new method was used for ab initio predictions as part of CASP5. This work was presented at the Winter School in Bioinformatics, Bologna, Italy, 10–14 February 2003.

  10. Ab initio dynamics of the cytochrome P450 hydroxylation reaction

    Energy Technology Data Exchange (ETDEWEB)

    Elenewski, Justin E.; Hackett, John C, E-mail: jchackett@vcu.edu [Department of Physiology and Biophysics and The Massey Cancer Center, School of Medicine, Virginia Commonwealth University, 401 College Street, Richmond, Virginia 23219-1540 (United States)

    2015-02-14

    The iron(IV)-oxo porphyrin π-cation radical known as Compound I is the primary oxidant within the cytochromes P450, allowing these enzymes to affect the substrate hydroxylation. In the course of this reaction, a hydrogen atom is abstracted from the substrate to generate hydroxyiron(IV) porphyrin and a substrate-centered radical. The hydroxy radical then rebounds from the iron to the substrate, yielding the hydroxylated product. While Compound I has succumbed to theoretical and spectroscopic characterization, the associated hydroxyiron species is elusive as a consequence of its very short lifetime, for which there are no quantitative estimates. To ascertain the physical mechanism underlying substrate hydroxylation and probe this timescale, ab initio molecular dynamics simulations and free energy calculations are performed for a model of Compound I catalysis. Semiclassical estimates based on these calculations reveal the hydrogen atom abstraction step to be extremely fast, kinetically comparable to enzymes such as carbonic anhydrase. Using an ensemble of ab initio simulations, the resultant hydroxyiron species is found to have a similarly short lifetime, ranging between 300 fs and 3600 fs, putatively depending on the enzyme active site architecture. The addition of tunneling corrections to these rates suggests a strong contribution from nuclear quantum effects, which should accelerate every step of substrate hydroxylation by an order of magnitude. These observations have strong implications for the detection of individual hydroxylation intermediates during P450 catalysis.

  11. Unified ab initio approaches to nuclear structure and reactions

    Science.gov (United States)

    Navrátil, Petr; Quaglioni, Sofia; Hupin, Guillaume; Romero-Redondo, Carolina; Calci, Angelo

    2016-05-01

    The description of nuclei starting from the constituent nucleons and the realistic interactions among them has been a long-standing goal in nuclear physics. In addition to the complex nature of the nuclear forces, with two-, three- and possibly higher many-nucleon components, 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. After a brief overview of the field, we focus on ab initio many-body approaches—built upon the no-core shell model—that are capable of simultaneously describing both bound and scattering nuclear states, and present results for resonances in light nuclei, reactions important for astrophysics and fusion research. In particular, we review recent calculations of resonances in the 6He halo nucleus, of five- and six-nucleon scattering, and an investigation of the role of chiral three-nucleon interactions in the structure of 9Be. Further, we discuss applications to the 7Be {({{p}},γ )}8{{B}} radiative capture. Finally, we highlight our efforts to describe transfer reactions including the 3H{({{d}},{{n}})}4He fusion.

  12. Three-cluster dynamics within an ab initio framework

    CERN Document Server

    Quaglioni, S; Navrátil, P

    2013-01-01

    We introduce a fully antisymmetrized treatment of three-cluster dynamics within the ab initio framework of the no-core shell model/resonating-group method (NCSM/RGM). Energy-independent non-local interactions among the three nuclear fragments are obtained from realistic nucleon-nucleon interactions and consistent ab initio many-body wave functions of the clusters. The three-cluster Schr\\"odinger equation is solved with bound-state boundary conditions by means of the hyperspherical-harmonic method on a Lagrange mesh. We discuss the formalism in detail and give algebraic expressions for systems of two single nucleons plus a nucleus. Using a soft similarity-renormalization-group evolved chiral nucleon-nucleon potential, we apply the method to an $^4$He+$n+n$ description of $^6$He and compare the results to experiment and to a six-body diagonalization of the Hamiltonian performed within the harmonic-oscillator expansions of the NCSM. Differences between the two calculations provide a measure of core ($^4$He) pola...

  13. AB INITIO SIMULATIONS FOR MATERIAL PROPERTIES ALONG THE JUPITER ADIABAT

    International Nuclear Information System (INIS)

    We determine basic thermodynamic and transport properties of hydrogen-helium-water mixtures for the extreme conditions along Jupiter's adiabat via ab initio simulations, which are compiled in an accurate and consistent data set. In particular, we calculate the electrical and thermal conductivity, the shear and longitudinal viscosity, and diffusion coefficients of the nuclei. We present results for associated quantities like the magnetic and thermal diffusivity and the kinematic shear viscosity along an adiabat that is taken from a state-of-the-art interior structure model. Furthermore, the heat capacities, the thermal expansion coefficient, the isothermal compressibility, the Grüneisen parameter, and the speed of sound are calculated. We find that the onset of dissociation and ionization of hydrogen at about 0.9 Jupiter radii marks a region where the material properties change drastically. In the deep interior, where the electrons are degenerate, many of the material properties remain relatively constant. Our ab initio data will serve as a robust foundation for applications that require accurate knowledge of the material properties in Jupiter's interior, e.g., models for the dynamo generation.

  14. 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 ...... as the fate of HOCO, determines the oxidation rate of formic acid. At lower temperatures HO2, formed from HOCO + O2, is an important chain carrier and modeling predictions become sensitive to the HOCHO + HO2 reaction. © 2014 The Combustion Institute.......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...... on calculations with the kinetic model. Formic acid is consumed mainly by reaction with OH, yielding OCHO, which dissociates rapidly to CO2 + H, and HOCO, which may dissociate to CO + OH or CO2 + H, or react with H, OH, or O2 to form more stable products. The branching fraction of the HOCHO + OH reaction, as well...

  15. Unified ab initio approaches to nuclear structure and reactions

    CERN Document Server

    Navratil, Petr; Hupin, Guillaume; Romero-Redondo, Carolina; Calci, Angelo

    2016-01-01

    The description of nuclei starting from the constituent nucleons and the realistic interactions among them has been a long-standing goal in nuclear physics. In addition to the complex nature of the nuclear forces, with two-, three- and possibly higher many-nucleon components, 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 {\\em ab initio} nuclear structure and reaction calculations based on input from QCD-employing Hamiltonians constructed within chiral effective field theory. After a brief overview of the field, we focus on ab initio many-body approaches - built upon the No-Core Shell Model - that are capable of simultaneously describing both bound and scattering nuclear states, and present results for resonances in light nuclei, reactions important for astrophysics and fusion research. In particular, we review recent calculations of resonances in the $^6$He halo nucleus, of five- and six...

  16. um estudo de caso no concelho de Ponta Delgada

    OpenAIRE

    Dias, Débora Pacheco de Medeiros

    2014-01-01

    Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências da Educação: Educação Especial, área de especialização em Domínio Cognitivo e Motor O estudo em presença centra-se na problemática das atitudes dos docentes do ensino pré-escolar e do 1º ciclo perante os comportamentos agressivos manifestados pelos seus alunos em contexto de sala de aula. Neste trabalho procede-se à descrição, avaliação e comparação das teor...

  17. estudo comparativo entre escolas públicas e privadas

    OpenAIRE

    Vieira, Fernanda Maria Mesquita

    2012-01-01

    Este estudo tem como objetivo averiguar se existe satisfação profissional e sócio-organizacional entre membros de Direções de Escolas do Básico e do Secundário, do ensino público e privado, nomeadamente porque a investigação, nos domínios da gestão e da psicologia do trabalho e das organizações, preconiza que a satisfação profissional e a sócio-organizacional, direta ou indiretamente, se encontram ligadas à produtividade e à realização pessoal, aspetos estes que não são alheios às atuais polí...

  18. Planeamento de uma estrada utilizando CCS Candy - Caso de estudo

    OpenAIRE

    Oliveira, Sara Maria de

    2013-01-01

    O tema desta dissertação foi escolhido tendo em consideração a crescente necessidade de planeamento de empreitadas de construção de estradas, sendo um dos objetivos desta dissertação o de oferecer uma visão global do processo de planeamento da construção de uma estrada, focado apenas no fator tempo, recorrendo a ferramentas informáticas e utilizando um caso de estudo de uma estrada real e já construída. Inicialmente, faz-se uma breve descrição dos métodos de planeamento mais aplicados em p...

  19. Abordagens psicológicas no estudo do trabalho

    OpenAIRE

    Marques, Carlos Alberto Alves

    1989-01-01

    O artigo apresenta duas categorias psicológicas do estudo do trabalho, técnica e metodologicamente distintas mas complementares na intervenção organizacional: a perspectiva ergonómica e a da representação das características das tarefas. Em relação a primeira, para além da sua apresentação, o autor discute níveis de intervenção ergonómica, destacando as áreas de acção da psicologia cognitiva e da Ergonomia dos Sistemas, borderline da psicologia das organizações. Em ...

  20. Estudos sobre a paz e cultura da paz

    OpenAIRE

    Pureza, José Manuel

    2000-01-01

    Segundo o autor, a cultura da paz implica uma mudança quer na forma como a “alta cultura” lida com a realidade quer no tipo de abordagem que o senso comum faz às relações sociais, sendo que a ruptura com a ideologia conservadora, ou seja, com o senso comum realista só é possível graças a estas alterações. O autor realça tanto a importância que os estudos sobre a paz têm para o surgimento de um conceito amplo de paz, desenvolvido por Johan Galtung, como o facto destes esta...

  1. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wu Dianxing E-mail: dxwu@zju.edu.cn; 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. Cry1Ab protein from Bacillus thuringiensis and MON810 cry1Ab-transgenic maize exerts no adjuvant effect after airway exposure.

    Science.gov (United States)

    Andreassen, M; Bøhn, T; Wikmark, O-G; Van den Berg, J; Løvik, M; Traavik, T; Nygaard, U C

    2015-03-01

    The genetically modified (GM) maize event MON810 has been inserted with a processed version of the transgene, cry1Ab, derived from the soil bacterium Bacillus thuringiensis (Bt) to express proteins with insecticidal properties. Such proteins may introduce new allergens and also act as adjuvants that promote allergic responses. While focus has been on safe consumption and hence the oral exposure to GM food and feed, little is known regarding inhalation of pollen and desiccated airborne plant material from GM crops. The aim of this study was to investigate whether plant material from the Cry1Ab-expressing maize variety MON810, or trypsin-activated Cry1Ab (trypCry1Ab) protein produced in recombinant bacteria, may act as adjuvants against the allergen ovalbumin (OVA) in a mouse model of airway allergy. A clear proallergic adjuvant effect of the mucosal adjuvant cholera toxin (CT) was demonstrated, determined as increased specific IgE, eosinophils and Th2 cytokines in MLN cell supernates, while no elevation in OVA-specific antibodies or cytokine release from MLN cells after stimulation with OVA were observed in mice receiving Cry1Ab-containing plant materials or the trypCry1Ab protein. Our data suggest that Cry1Ab proteins had no detectable systemic adjuvant effect in mice after airway exposure. Further experiments with purified plant proteins, as well as long-term exposures needs be conducted to further evaluate exposures experienced in real-life situations. PMID:25564738

  4. Estudos cronotópicos em narrativas audiovisuais

    Directory of Open Access Journals (Sweden)

    Egle Müller Spinelli

    2008-11-01

    Full Text Available O presente trabalho pretende aplicar o conceito de cronotopia de Bakhtin à análise de narrativas audiovisuais. Para tanto, será discutido o conceito de cronotopo bakhtiniano e sua relação com os estudos de Saussure, com o intuito de mostrar como os elementos cronotópicos podem estar ligados a contextos que vão além do enunciado, remetendo a mecanismos da enunciação. No estudo são analisados filmes que apresentam determinadas características semelhantes às dos principais tipos de cronotopia estabelecidos por Bakhtin: a da aventura, a do cotidiano e a autobiográfica, respectivamente correspondentes aos filmes Corra Lola, Corra (Tom Tykwer, 1998, Boca de Ouro (Nelson Pereira dos Santos, 1962 e Rashomon (Akira Kurosawa, 1950. Palavras-chave: cronotopia; enunciação; cinema; Bakhtin Abstract Chronotopic studies in audiovisual narratives - This paper proposes to apply Bakhtin's concept of chronotopia in an analysis of audiovisual discourse. To this end, it discusses the Bakhtin's postulation of the chronotope and its relation with the studies of Saussure in order to show how chronotopic elements may be connected to contexts that go beyond simple statements, suggesting mechanisms of enunciation. The films Run Lola, Run (Tom Tykwer, 1998, Boca de Ouro (Nelson Pereira dos Santos, 1962 and Rashomon (Akira Kurosawa, 1950 are used here to illustrate the principal chronotopic types established by Bakhtin, namely, adventure, everyday life and autobiography. Key words: chronotope; enunciation; cinema; Bakhtin

  5. VIDA COTIDIANA, AFETIVIDADE E ESQUIZOFRENIA: UM ESTUDO EM ADULTOS PORTUGUESES

    Directory of Open Access Journals (Sweden)

    Teresa Freire

    2014-12-01

    Full Text Available O presente estudo, realizado em Portugal, teve como objetivo analisar as experiências da vida diária de pessoas com diagnóstico de esquizofrenia, com particular ênfase na dimensão afetiva da experiência. Recorreu-se ao Experience Sampling Method (ESM para recolha de dados relativos à experiência diária ao longo de uma semana. Participaram neste estudo 14 pessoas com pelos menos três anos de diagnóstico de esquizofrenia, estáveis do ponto de vista médico, a viver em contexto extra-hospitalar e alvo de projetos de reabilitação profissional. Os resultados indicam que os participantes passam grande parte do tempo em casa, sozinhos ou com a família, a realizar atividades de tempo livre. Os aspectos afetivos positivos (emoções e sentimentos predominam na sua vida diária, porém esta situação se altera quando os indivíduos estão sozinhos, havendo um decréscimo acentuado da afetividade positiva e um aumento significativo da afetividade negativa. Estes resultados reforçam a perspectiva de integração comunitária e a necessidade de esta ser acompanhada da criação de estruturas comunitárias que promovam atividades integradas de reabilitação, estruturadas e promotoras do desenvolvimento e das interações sociais.

  6. 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.

  7. Coerência textual: um estudo com jovens e adultos

    Directory of Open Access Journals (Sweden)

    Gonçalves Fabíola

    2003-01-01

    Full Text Available A coerência é um fenômeno lingüístico responsável pela construção de sentido que garante a interpretabilidade de um texto. As investigações conduzidas pela psicologia cognitiva têm investido esforços no exame da coerência a partir da perspectiva daqueles que recebem o texto. Este estudo examinou se o estabelecimento da coerência textual está relacionado à aquisição da leitura e da escrita com jovens e adultos, em processo de alfabetização, em uma situação de produção de texto. Alunos entre 15 a 45 anos, matriculados no 1º e 2º ciclos da Educação Básica de Jovens e Adultos de uma escola pública, foram individualmente solicitados a produzir oralmente uma história original. As histórias foram analisadas em função de indicadores específicos, agrupados em um sistema de análise, o qual expressa níveis distintos acerca do estabelecimento da coerência. Comparações entre os ciclos foram realizadas. Os resultados obtidos corroboram estudo realizado com crianças. Há indicadores mais fáceis de serem estabelecidos do que outros. Pode-se argumentar que a escolaridade contribui para o estabelecimento da coerência na produção de história.

  8. Living with an imperfect cell wall: compensation of femAB inactivation in Staphylococcus aureus.

    OpenAIRE

    Bierbaum Gabriele; Harris Llinos G; Majcherczyk Paul A; Schäfer Juliane; Kotte Oliver; Jansen Andrea; Hübscher Judith; Heinemann Matthias; Berger-Bächi Brigitte

    2007-01-01

    Abstract Background Synthesis of the Staphylococcus aureus peptidoglycan pentaglycine interpeptide bridge is catalyzed by the nonribosomal peptidyl transferases FemX, FemA and FemB. Inactivation of the femAB operon reduces the interpeptide to a monoglycine, leading to a poorly crosslinked peptidoglycan. femAB mutants show a reduced growth rate and are hypersusceptible to virtually all antibiotics, including methicillin, making FemAB a potential target to restore β-lactam susceptibility in met...

  9. Performance of the Molecular Alere i Influenza A&B Test Compared to That of the Xpert Flu A/B Assay

    OpenAIRE

    Chapin, Kimberle C.; Flores-Cortez, Estefany J.

    2014-01-01

    Data on the performance of rapid molecular point-of-care use platforms for diagnosis of influenza are lacking. We validated nasopharyngeal (NP) flocked specimens in universal transport medium (UTM) and evaluated the clinical sensitivity and specificity of the Alere i influenza A&B test compared to those of the Xpert flu A/B assay. The Alere i influenza A&B test had an overall sensitivity and specificity of 93.8% and 62.5% for influenza A, respectively, and of 91.8% and 53.6% for influenza B, ...

  10. Effect of Rapid Quenching on Electrochemical Properties of AB5 and AB3.5-Type Hydrogen Storage Alloys

    Institute of Scientific and Technical Information of China (English)

    Li Ping; Zheng Xueping; An Fuqiang; Islam S. Humail; Qu Xuanhui

    2007-01-01

    Effect of rapid quenching on the electrochemical properties of AB5 and AB3.5-type hydrogen storage alloys was studied. The results indicated that the discharge capacities of the rapid quenching MmNi3.55 Co0.75 Mn0.4Al0.3 alloys decrease under 25 and -35℃ with the increase of the quenching rate. Comparatively, the decrease extent of the quenching alloys at -35℃ is lower than that at 25℃. The result on the study of the cycle life indicated that the quenching process was favorable to improve the cycle stabilities of the MmNi3.55Co0.75-Mn0.4Al0.3alloys under 25 and -35℃. Whereas, the effect of the quenching process on the La0.7Mg0.3(Ni0.85Co0.15)3.5 alloy was different at 25℃ from at -35℃. Under 25℃, the cycle life of the alloy was obviously improved by the quenching process, however, the quenching process did not improve but decreased slightly the cycle life at -35℃.

  11. Effect of Flame Retardant Containing Phosphorus and Silicone on Thermal Performance of PC/ABS

    Institute of Scientific and Technical Information of China (English)

    WEI Ping; WU Dan; ZHONG Hanfang; DU Jianxin

    2009-01-01

    A flame retardant (DPA-SiN) containing phosphorus, nitrogen and silicon elements was synthesized. The halogen free flame retardant was incorporated into PC/ABS to improve its flame retardancy. The flame-retardant properties of the PC/ABS/DPA-SiN blends were estimated bylimiting oxygen index (LOI) values and CONE Calorimeter, while thermal stabilities were investi-gated through thermo gravimetric analysis (TGA). The PC/ABS/DPA-SiN blends were thermally de-graded at 400 ℃ for different amounts of time and studied by Fourier transform infrared spectros-copy (FTIR) to better understand the degradation behavior of PC/ABS/DPA-SiN.

  12. Adsorption of insecticidal Cry1Ab protein to humic substances. 1. Experimental approach and mechanistic aspects.

    Science.gov (United States)

    Sander, Michael; Tomaszewski, Jeanne E; Madliger, Michael; Schwarzenbach, René P

    2012-09-18

    Adsorption is a key process affecting the fate of insecticidal Cry proteins (Bt toxins), produced by genetically modified Bt crops, in soils. However, the mechanisms of adsorption to soil organic matter (SOM) remain poorly understood. This work assesses the forces driving the adsorption of Cry1Ab to Leonardite humic acid (LHA), used as a model for SOM. We studied the effects of solution pH and ionic strength (I) on adsorption using a quartz crystal microbalance with dissipation monitoring and optical waveguide lightmode spectroscopy. Initial Cry1Ab adsorption rates were close to diffusion-limited and resulted in extensive adsorption, even at pH >6, at which LHA and Cry1Ab carry negative net charges. Adsorption increased with decreasing I at pH >6, indicating Cry1Ab-LHA patch-controlled electrostatic attraction via positively charged domains of Cry1Ab. Upon rinsing, only a fraction of Cry1Ab desorbed, suggesting a range of interaction energies of Cry1Ab with LHA. Different interaction energies likely resulted from nonuniformity in the LHA surface polarity, with higher Cry1Ab affinities to more apolar LHA regions due to the hydrophobic effect. Contributions from the hydrophobic effect were substantiated by comparison of the adsorption of Cry1Ab and the reference proteins albumin and lysozyme to LHA and to apolar and polar model surfaces. PMID:22862304

  13. 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.

  14. Effects of Ethylene/Vinyl Chloride/Vinyl Laurate Redispersible Terpolymer on Pore Structure and Properties of Cement Mortar%E/VC/VL三元共聚物对水泥砂浆孔结构和性能的影响

    Institute of Scientific and Technical Information of China (English)

    张国防; 王培铭

    2013-01-01

    Effects of ethylene/vinyl chloride/vinyl laurate redispersible terpolymer(E/VC/VL) on the pore structure of cement mortar were studied through mercury intrusion porosimeter(MIP) and environmental scanning electron microscopy(ESEM). The relationships between the pore structure and the properties of cement mortar were also discussed. The results show that E/VC/VL remarkably affects the pore structure of cement mortar. E/VC/VL definitely increases the total pore volume, porosity and the average pore radius. E/VC/VL significantly increases the content of large capillary pores of cement mortar, which distribute in the C-S-H gel. With the increase of its use level, the effect of E/VC/VL on the pore structure of cement mortar is enhanced. As the porosity and the total pore volume of cement mortar modified with E/VC/VL increases, the bulk density and the compressive strength of cement mortar decrease, but the water permeation resistance is greatly enhanced.%利用压汞法和环境扫描电子显微镜分析方法,研究了乙烯/氯乙烯/月桂酸乙烯酯(E/VC/VL)三元共聚物对水泥砂浆孔结构的影响规律,并探讨了其与水泥砂浆的体积密度、抗压强度、抗水渗性、吸水量和吸水率等宏观性能的关系.研究表明:E/VC/VL三元共聚物能显著影响水泥砂浆的孔结构,增大水泥砂浆的孔隙率、总孔体积和平均孔半径;导致大毛细孔显著增多,且密布在C-S-H凝胶之间.E/VC/VL三元共聚物掺量越大,对水泥砂浆孔结构的影响越显著.E/VC/VL三元共聚物改性水泥砂浆的孔隙率和孔体积与宏观性能之间存在密切关系:孔隙率和孔体积越大,水泥砂浆的体积密度和抗压强度越小,但其抗水分渗透性能则越好.

  15. SYSTHESIS AND PERFORMANCES OF ABS RESIN TOUGHENED BY SIBR VIA BULK POLYMERIZATION METHOD——STRUCTURE, PROPERTIES AND FRACTURE MECHNISM%SIBR增韧本体法ABS树脂的合成与性能——结构与性能及断裂机理

    Institute of Scientific and Technical Information of China (English)

    于志省; 杜晓旭; 李杨

    2012-01-01

    以活性负离子聚合法合成的不同分子量和单体配比的苯乙烯-异戊二烯-丁二烯三元共聚物橡胶(SIBR)为增韧剂,以双官能团引发剂引发,采用本体聚合方法合成了系列ABS树脂,利用经典相分离技术、SEC、TEM和力学试验对聚合试样的结构、分子量、形态及性能进行了表征,并以SEM对冲击后的断面形貌进行观察以探究其断裂机理.结果发现,随着SIBR分子量的增大,橡胶相尺寸增大,接枝率下降,相界面明显,但冲击强度有所提高;SIBR中St组分含量增加,粒子均匀,但刚性增大,对抗冲击性能不利.高Mn、低St组分含量SIBR抵抗裂纹形成和扩展的能力强,ABS呈韧件断裂方式,以丰富的银纹化、明显的剪切屈服和大量系联带的撕裂为主要断裂机理;低Mn、高St组分含量SIBR抵抗裂纹形成和扩展的能力较低,ABS以半韧性方式断裂,断裂机理以基体甥化、剥离和界面的应力白化现象为主.%The styrene-isoprene-butadiene terpolymer rubbers ( SIBRs) with different molecular weights and monomer ratios were first synthesized by living anionic polymerization method. A series of ABS resins were prepared via bulk polymerization method under the initiation of difunctional initiator modified by the foresaid SIBR tougheners. The molecular structure, morphology and performances of ABS were characterized by typical phase-separating method, SEC, TEM and mechanical testing, respectively. And SEM technique was used for observing the fractured surfaces of specimens after impact in order to study the fracture mechanism. The results show that with increasing the molecular weight of SIBR,the rubber phase size increases and the grafting degree decreases besides gradually obvious phase interface and improved impact properties. Moreover, increasing thestyrene content in SIBR could lead to relatively uniform particles, but goes against the impact resistance due to its rigidity. The SIBR with higher

  16. Internetmarknadsföring inom turismen : Case Esbo Turism Ab

    OpenAIRE

    Gothoni, Jenny

    2010-01-01

    I detta arbetet behandlas kundförnöjsamheten med Esbo Turism Abs hemsidor, och ifall dessa kan förbättras ytterligare. Teorin baserar sig mycket på marknadsföring samt kundens beteende och behov, internetsidor samt kvalitet och segmentering. Undersökningen har genomförts med hjälp av webbenkäter och litet djupare e-post intervjuer under våren 2010. I undersökningen deltog 30 personer i enkäterna och tre stycken i intervjuerna. Störst svarskvot bildades av 15-25 åringar från Helsingfors. ...

  17. 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.

  18. Ab initio study of the transition-metal carbene cations

    Institute of Scientific and Technical Information of China (English)

    李吉海; 冯大诚; 冯圣玉

    1999-01-01

    The geometries and bonding characteristics of the first-row transition-metal carbene cations MCH2+ were investigated by ab initio molecular orbital theory (HF/LANL2DZ). All of MCH2+ are coplanar. In the closed shell structures the C bonds to M with double bonds; while in the open shell structures the partial double bonds are formed, because one of the σ and π orbitals is singly occupied. It is mainly the π-type overlap between the 2px orbital of C and 4px, 3dxz, orbitals of M+ that forms the π orbitals. The dissociation energies of C—M bond appear in periodic trend from Sc to Cu. Most of the calculated bond dissociation energies are close to the experimental ones.

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

    Science.gov (United States)

    Wu, Henry; Mayeshiba, Tam; Morgan, Dane

    2016-01-01

    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. PMID:27434308

  20. Transport coefficients in diamond from ab-initio calculations

    Science.gov (United States)

    Löfâs, Henrik; Grigoriev, Anton; Isberg, Jan; Ahuja, Rajeev

    2013-03-01

    By combining the Boltzmann transport equation with ab-initio electronic structure calculations, we obtain transport coefficients for boron-doped diamond. We find the temperature dependence of the resistivity and the hall coefficients in good agreement with experimental measurements. Doping in the samples is treated via the rigid band approximation and scattering is treated in the relaxation time approximation. In contrast to previous results, the acoustic phonon scattering is the dominating scattering mechanism for the considered doping range. At room temperature, we find the thermopower, S, in the range 1-1.6 mV/K and the power factor, S2σ, in the range 0.004-0.16 μW /cm K2.

  1. Efficient Ab initio Modeling of Random Multicomponent Alloys.

    Science.gov (United States)

    Jiang, Chao; Uberuaga, Blas P

    2016-03-11

    We present in this Letter a novel small set of ordered structures (SSOS) method that allows extremely efficient ab initio modeling of random multicomponent alloys. Using inverse II-III spinel oxides and equiatomic quinary bcc (so-called high entropy) alloys as examples, we demonstrate that a SSOS can achieve the same accuracy as a large supercell or a well-converged cluster expansion, but with significantly reduced computational cost. In particular, because of this efficiency, a large number of quinary alloy compositions can be quickly screened, leading to the identification of several new possible high-entropy alloy chemistries. The SSOS method developed here can be broadly useful for the rapid computational design of multicomponent materials, especially those with a large number of alloying elements, a challenging problem for other approaches. PMID:27015491

  2. Efficient Ab initio Modeling of Random Multicomponent Alloys

    Science.gov (United States)

    Jiang, Chao; Uberuaga, Blas P.

    2016-03-01

    We present in this Letter a novel small set of ordered structures (SSOS) method that allows extremely efficient ab initio modeling of random multicomponent alloys. Using inverse II-III spinel oxides and equiatomic quinary bcc (so-called high entropy) alloys as examples, we demonstrate that a SSOS can achieve the same accuracy as a large supercell or a well-converged cluster expansion, but with significantly reduced computational cost. In particular, because of this efficiency, a large number of quinary alloy compositions can be quickly screened, leading to the identification of several new possible high-entropy alloy chemistries. The SSOS method developed here can be broadly useful for the rapid computational design of multicomponent materials, especially those with a large number of alloying elements, a challenging problem for other approaches.

  3. Ab initio electronic structure and optical conductivity of bismuth tellurohalides

    CERN Document Server

    Schwalbe, Sebastian; Starke, Ronald; Schober, Giulio A H; Kortus, Jens

    2016-01-01

    We investigate the electronic structure, dielectric and optical properties of bismuth tellurohalides BiTeX (X = I, Cl, Br) by means of all-electron density functional theory. In particular, we present the ab initio conductivities and dielectric tensors calculated over a wide frequency range, and compare our results with the recent measurements by Akrap et al. , Makhnev et al. , and Rusinov et al. . We show how the low-frequency branch of the optical conductivity can be used to identify characteristic intra- and interband transitions between the Rashba spin-split bands in all three bismuth tellurohalides. We further calculate the refractive indices and dielectric constants, which in turn are systematically compared to previous predictions and measurements. We expect that our quantitative analysis will contribute to the general assessment of bulk Rashba materials for their potential use in spintronics devices.

  4. Ab initio H2O in realistic hydrophilic confinement.

    Science.gov (United States)

    Allolio, Christoph; Klameth, Felix; Vogel, Michael; Sebastiani, Daniel

    2014-12-15

    A protocol for the ab initio construction of a realistic cylindrical pore in amorphous silica, serving as a geometric nanoscale confinement for liquids and solutions, is presented. Upon filling the pore with liquid water at different densities, the structure and dynamics of the liquid inside the confinement can be characterized. At high density, the pore introduces long-range oscillations into the water density profile, which makes the water structure unlike that of the bulk across the entire pore. The tetrahedral structure of water is also affected up to the second solvation shell of the pore wall. Furthermore, the effects of the confinement on hydrogen bonding and diffusion, resulting in a weakening and distortion of the water structure at the pore walls and a slowdown in diffusion, are characterized. PMID:25208765

  5. Quantum plasmonics: from jellium models to ab initio calculations

    Directory of Open Access Journals (Sweden)

    Varas Alejandro

    2016-08-01

    Full Text Available Light-matter interaction in plasmonic nanostructures is often treated within the realm of classical optics. However, recent experimental findings show the need to go beyond the classical models to explain and predict the plasmonic response at the nanoscale. A prototypical system is a nanoparticle dimer, extensively studied using both classical and quantum prescriptions. However, only very recently, fully ab initio time-dependent density functional theory (TDDFT calculations of the optical response of these dimers have been carried out. Here, we review the recent work on the impact of the atomic structure on the optical properties of such systems. We show that TDDFT can be an invaluable tool to simulate the time evolution of plasmonic modes, providing fundamental understanding into the underlying microscopical mechanisms.

  6. Highly anisotropic thermal conductivity of arsenene: An ab initio study

    Science.gov (United States)

    Zeraati, Majid; Vaez Allaei, S. Mehdi; Abdolhosseini Sarsari, I.; Pourfath, Mahdi; Donadio, Davide

    2016-02-01

    Elemental two-dimensional (2D) materials exhibit intriguing heat transport and phononic properties. Here we have investigated the lattice thermal conductivity of newly proposed arsenene, the 2D honeycomb structure of arsenic, using ab initio calculations. Solving the Boltzmann transport equation for phonons, we predict a highly anisotropic thermal conductivity of 30.4 and 7.8 W/mK along the zigzag and armchair directions, respectively, at room temperature. Our calculations reveal that phonons with mean free paths between 20 nm and 1 μ m provide the main contribution to the large thermal conductivity in the zigzag direction; mean free paths of phonons contributing to heat transport in the armchair directions range between 20 and 100 nm. The obtained anisotropic thermal conductivity and feasibility of synthesis, in addition to high electron mobility reported elsewhere, make arsenene a promising material for nanoelectronic applications and thermal management.

  7. Molecular ion LiHe+: ab initio study

    International Nuclear Information System (INIS)

    Highlights: ► Excited electronic states of LiHe+ are studied. ► Potential energy curves of thirteen states are calculated. ► Dipole moment and transition dipole moment functions are determined. ► Basic spectroscopic properties of the electronic states are derived. - Abstract: High level ab initio calculations are performed on the molecular ion LiHe+. Potential energy curves for the low-lying singlet and triplet electronic states are calculated using the multi-reference configuration interaction and single-reference coupled cluster methods with large basis sets. The corresponding dipole moments and transition dipole moments functions are also determined. The basic spectroscopic properties and excitation energies of the electronic states are derived from rovibrational bound state calculations.

  8. AB "DNB" banko įvaizdžio valdymas

    OpenAIRE

    Vaškelytė, Virginija

    2012-01-01

    Šio darbo tikslas - išnagrinėji AB „DNB“ banko įvaizdžio formavimą ir valdymą teoriniu bei praktiniu aspektu ir konstatavus įvaizdžio formavimo bei valdymo problemas sukurti banko įvaizdžio tobulinimo modelį. Teorinėje darbo dalyje analizuojama organizacijos įvaizdžio samprata, kūrimo lygiai, pagrindiniai veiksniai, formuojantys organizacijos įvaizdį. Taip pat teorinėje dalyje analizuojami, lyginami organizacijos įvaizdžio kūrimo modeliai bei banko įvaizdžio valdymas. Analitinėje baigiamojo d...

  9. Socialiai atsakingo verslo koncepcijos įgyvendinimas AB "Lietuvos draudimas"

    OpenAIRE

    Žukauskienė, Justina

    2010-01-01

    Bakalauro baigiamajame darbe nagrinėjama socialiai atsakingo verslo koncepcija, pateikiami socialinės atsakomybės modeliai, kuriais remiantis įmonės gali įgyvendinti socialinę atsakomybę. Apžvelgiama Lietuvos patirtis socialinės atsakomybės srityje. Pateikiama ne tik socialinės atsakomybės nauda įmonei ir visuomenei, bet ir kritiškas požiūris į socialinę atsakomybę. Darbe analizuojamas AB „Lietuvos draudimas“ įgyvendinamas socialinės atsakomybės modelis. Nustatyta, kad įmonė socialinę atsakom...

  10. Ab initio methods for electron-molecule collisions

    International Nuclear Information System (INIS)

    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

  11. An Efficient Approach to Ab Initio Monte Carlo Simulation

    CERN Document Server

    Leiding, Jeff

    2013-01-01

    We present a Nested Markov Chain Monte Carlo (NMC) scheme for building equilibrium averages based on accurate potentials such as density functional theory. Metropolis sampling of a reference system, defined by an inexpensive but approximate potential, is used to substantially decorrelate configurations at which the potential of interest is evaluated, thereby dramatically reducing the number needed to build ensemble averages at a given level of precision. The efficiency of this procedure is maximized on-the-fly through variation of the reference system thermodynamic state (characterized here by its inverse temperature \\beta^0), which is otherwise unconstrained. Local density approximation (LDA) results are presented for shocked states in argon at pressures from 4 to 60 GPa. Depending on the quality of the reference potential, the acceptance probability is enhanced by factors of 1.2-28 relative to unoptimized NMC sampling, and the procedure's efficiency is found to be competitive with that of standard ab initio...

  12. Ab-initio melting curve and principal Hugoniot of tantalum

    International Nuclear Information System (INIS)

    We report first principles calculations of the melting curve and principal Hugoniot (P - V curve) of body centered cubic (bcc) tantalum in the pressure range 0-300 GPa. A description of lattice dynamics and thermal properties of bcc Ta using finite temperature density functional theory (DFT) is presented. The approach works within the projector augmented wave (PAW) implementation of DFT and explicitly treats in valence the 5p, 6s and 5d electrons. The principal Hugoniot (P - V curve), obtained using the Rankine-Hugoniot equation, is investigated using the generalized gradient approximations (GGA). Very good agreement with the shock experiments is obtained with GGA in all the range of pressure. We also report the temperature-pressure relation on the shock Hugoniot and the full ab-initio melting curve of Ta

  13. Diode laser welding of ABS: Experiments and process modeling

    CERN Document Server

    Ilie, Mariana; Mattei, Simone; Cicala, Eugen; Stoica, Virgil; 10.1016/j.optlastec.2008.10.005

    2010-01-01

    The laser beam weldability of acrylonitrile/butadiene/styrene (ABS) plates is determined by combining both experimental and theoretical aspects. In modeling the process, an optical model is used to determine how the laser beam is attenuated by the first material and to obtain the laser beam profile at the interface. Using this information as the input data to a thermal model, the evolution of the temperature field within the two components can be estimated. The thermal model is based on the first principles of heat transfer and utilizes the temperature variation laws of material properties. Corroborating the numerical results with the experimental results, some important insights concerning the fundamental phenomena that govern the process could be extracted. This approach proved to be an efficient tool in determining the weldability of polimeric materials and assures a significant reduction of time and costs with the experimental exploration.

  14. Ab Initio Study of KCl and NaCl Clusters

    Science.gov (United States)

    Brownrigg, Clifton; Hira, Ajit; Pacheco, Jose; Salazar, Justin

    2013-03-01

    We continue our interest in the theoretical study of molecular clusters to examine the chemical properties of small KnCln and NanCln clusters (n = 2 - 15). The potentially important role of these molecular species in biochemical and medicinal processes is well known. This work applies the hybrid ab initio methods of quantum chemistry to derive the different alkali-halide (MnHn) geometries. Of particular interest is the competition between hexagonal ring geometries and rock salt structures. Electronic energies, rotational constants, dipole moments, and vibrational frequencies for these geometries are calculated. Magic numbers for cluster stability are identified and are related to the property of cluster compactness. Mapping of the singlet, triplet, and quintet, potential energy surfaces is performed. Calculations have been performed to examine the interactions of these clusters with some atoms and molecules of biological interest, including O, O2, and Fe. The potential for design of new medicinal drugs is explored.

  15. Ab initio electronic stopping power of protons in bulk materials

    Science.gov (United States)

    Shukri, Abdullah Atef; Bruneval, Fabien; Reining, Lucia

    2016-01-01

    The electronic stopping power is a crucial quantity for ion irradiation: it governs the deposited heat, the damage profile, and the implantation depth. Whereas experimental data are readily available for elemental solids, the data are much more scarce for compounds. Here we develop a fully ab initio computational scheme based on linear response time-dependent density-functional theory to predict the random electronic stopping power (RESP) of materials without any empirical fitting. We show that the calculated RESP compares well with experimental data, when at full convergence, with the inclusion of the core states and of the exchange correlation. We evaluate the unexpectedly limited magnitude of the nonlinear terms in the RESP by comparing with other approaches based on the time propagation of time-dependent density-functional theory. Finally, we check the validity of a few empirical rules of thumbs that are commonly used to estimate the electronic stopping power.

  16. Interatomic Coulombic decay widths of helium trimer: Ab initio calculations

    Energy Technology Data Exchange (ETDEWEB)

    Kolorenč, Přemysl, E-mail: kolorenc@mbox.troja.mff.cuni.cz [Charles University in Prague, Faculty of Mathematics and Physics, Institute of Theoretical Physics, V Holešovičkách 2, 180 00 Prague (Czech Republic); Sisourat, Nicolas [Sorbonne Universités, UPMC Univ Paris 06, UMR 7614, Laboratoire de Chimie Physique Matière et Rayonnement, F-75005 Paris (France); CNRS, UMR 7614, Laboratoire de Chimie Physique Matière et Rayonnement, F-75005 Paris (France)

    2015-12-14

    We report on an extensive study of interatomic Coulombic decay (ICD) widths in helium trimer computed using a fully ab initio method based on the Fano theory of resonances. Algebraic diagrammatic construction for one-particle Green’s function is utilized for the solution of the many-electron problem. An advanced and universal approach to partitioning of the configuration space into discrete states and continuum subspaces is described and employed. Total decay widths are presented for all ICD-active states of the trimer characterized by one-site ionization and additional excitation of an electron into the second shell. Selected partial decay widths are analyzed in detail, showing how three-body effects can qualitatively change the character of certain relaxation transitions. Previously unreported type of three-electron decay processes is identified in one class of the metastable states.

  17. OPTIMIZATION STUDY IN MANUFACTURING PROCESS FOR PC/ABS BLENDS

    Institute of Scientific and Technical Information of China (English)

    Huang Chenghung; Fung Chinping; Chang Shihhsing; Hwang Jiunren; Doong Jiliang

    2003-01-01

    The optimization of injection molding process for polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blends is studied using Taguchi method and principal component analysis (PCA). Four controllable process factors are studied at three levels each in the manufacturing process. The L9 orthogonal array is conducted to determine the optimum process factor/level combination for single quality of mechanical properties. In addition, the principal component analysis is employed to transform the correlated mechanical properties to a set of uncorrelated components and to evaluate a comprehensive index for multi-response cases. Then the optimum process factor/level combination for multiple qualities can be determined. Finally, the analysis of variance is used to find out the most influential injection molding parameter for single and multiple qualities problems.

  18. 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)

  19. Ab initio Potential Energy Surface for H-H2

    Science.gov (United States)

    Partridge, Harry; Bauschlicher, Charles W., Jr.; Stallcop, James R.; Levin, Eugene

    1993-01-01

    Ab initio calculations employing large basis sets are performed to determine an accurate potential energy surface for H-H2 interactions for a broad range of separation distances. At large distances, the spherically averaged potential determined from the calculated energies agrees well with the corresponding results determined from dispersion coefficients; the van der Waals well depth is predicted to be 75 +/- (mu)E(sub h). Large basis sets have also been applied to reexamine the accuracy of theoretical repulsive potential energy surfaces. Multipolar expansions of the computed H-H2 potential energy surface are reported for four internuclear separation distances (1.2, 1.401, 1.449, and 1.7a(sub 0) of the hydrogen molecule. The differential elastic scattering cross section calculated from the present results is compared with the measurements from a crossed beam experiment.

  20. Ab initio investigation of the mechanical properties of copper

    Institute of Scientific and Technical Information of China (English)

    Liu Yue-Lin; Gui Li-Jiang; Jin Shuo

    2012-01-01

    Employing the ab initio total energy method based on the density functional theory with the generalized gradient approximation,we have systematically investigated the theoretical mechanical properties of copper (Cu).The theoretical tensile strengths are calculated to be 25.3 GPa,5.9 GPa,and 37.6 GPa for the fcc Cu single crystal in the [001],[110],and [111] directions,respectively.Among the three directions,the [110] direction is the weakest one due to the occurrence of structure transition at the lower strain and the weakest interaction of atoms between the (110) planes,while the [111] direction is the strongest direction because of the strongest interaction of atoms between the (111) planes.In terms of the elastic constants of Cu single crystal,we also estimate some mechanical quantities of polycrystalline Cu,including bulk modulus B,shear modulus G,Young's modulus Ep,and Poisson's ratio v.

  1. Ab Initio Prediction of 29Si-NMR Chemical Shifts

    Institute of Scientific and Technical Information of China (English)

    CHU Shidong; LI Yingxia; SONG Ni; GUAN Huashi

    2002-01-01

    The ability of several ab initio models to predict experimental 29Si-NMR chemical shift is examined. The shielding values of trimethylsilyl chloride (A), t-butyldimethylsilyl chloride (B) and allyltrimethylsilane (C) are calculated by GIAO, CSGT and IGAIM methods, using HF/6-31G*, B3LYP/6-31G*, HF/6-311+G**, B3LYP/6-311+G** and MPWlPW91/6-311+G** models respectively. The 29Si chemical shifts calculated by GIAO method using HF/6-311+G**model are highly in agreement with those obtained experimentally. All of the models above reproduce the trends of chemical shifts in all cases studied, suggesting that the models are of practical value.

  2. A Review on Ab Initio Approaches for Multielectron Dynamics

    CERN Document Server

    Ishikawa, Kenichi L

    2015-01-01

    In parallel with the evolution of femtosecond and attosecond laser as well as free-electron laser technology, a variety of theoretical methods have been developed to describe the behavior of atoms, molecules, clusters, and solids under the action of those laser pulses. Here we review major ab initio wave-function-based numerical approaches to simulate multielectron dynamics in atoms and molecules driven by intense long-wavelength and/or ultrashort short-wavelength laser pulses. Direct solution of the time-dependent Schr\\"odinger equation (TDSE), though its applicability is limited to He, ${\\rm H}_2$, and Li, can provide an exact description and has been greatly contributing to the understanding of dynamical electron-electron correlation. Multiconfiguration self-consistent-field (MCSCF) approach offers a flexible framework from which a variety of methods can be derived to treat both atoms and molecules, with possibility to systematically control the accuracy. The equations of motion of configuration interactio...

  3. Ab initio quantum dynamics using coupled-cluster.

    Science.gov (United States)

    Kvaal, Simen

    2012-05-21

    The curse of dimensionality (COD) limits the current state-of-the-art ab initio propagation methods for non-relativistic quantum mechanics to relatively few particles. For stationary structure calculations, the coupled-cluster (CC) method overcomes the COD in the sense that the method scales polynomially with the number of particles while still being size-consistent and extensive. We generalize the CC method to the time domain while allowing the single-particle functions to vary in an adaptive fashion as well, thereby creating a highly flexible, polynomially scaling approximation to the time-dependent Schrödinger equation. The method inherits size-consistency and extensivity from the CC method. The method is dubbed orbital-adaptive time-dependent coupled-cluster, and is a hierarchy of approximations to the now standard multi-configurational time-dependent Hartree method for fermions. A numerical experiment is also given. PMID:22612082

  4. Energiutredning på Chips AB, Åland

    OpenAIRE

    Renström, Thom; Sundbäck, Henrik

    2013-01-01

    En energikartläggning har gjorts hos Chips AB för att undersöka hur energin fördelas över de olika produktionslinjerna. Energianvändningen från processer som är gemensamma för alla produktionslinjer har också undersökts. Energianvändningen för dessa har fördelats över pro- duktionslinjerna eftersom produkterna även ska bära upp dessa energikostnader. Där det vi- sade sig att chipslinjen använder överlägset mest energi under ett år, 13 200 MWh, men den linjen körs mest o...

  5. Ab initio engineering of materials with stacked hexagonal tin frameworks

    Science.gov (United States)

    Shao, Junping; Beaufils, Clément; Kolmogorov, Aleksey N.

    2016-01-01

    The group-IV tin has been hypothesized to possess intriguing electronic properties in an atom-thick hexagonal form. An attractive pathway of producing sizable 2D crystallites of tin is based on deintercalation of bulk compounds with suitable tin frameworks. Here, we have identified a new synthesizable metal distannide, NaSn2, with a 3D stacking of flat hexagonal layers and examined a known compound, BaSn2, with buckled hexagonal layers. Our ab initio results illustrate that despite being an exception to the 8-electron rule, NaSn2 should form under pressures easily achievable in multi-anvil cells and remain (meta)stable under ambient conditions. Based on calculated Z2 invariants, the predicted NaSn2 may display topologically non-trivial behavior and the known BaSn2 could be a strong topological insulator. PMID:27387140

  6. Ab initio Molecular Dynamics Study on Small Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    叶林晖; 刘邦贵; 王鼎盛

    2001-01-01

    Ab initio molecular dynamics simulations are performed on small single wall nanotubes. By structural relaxation,the equilibrium C-C bond lengths and bond angles are determined. Our result shows that for both zigzag and armchair nanotubes there are two nonequivalent bond lengths. One bond stretches from that of the graphene sheet, while the other shrinks. Small variations on bond angles are also shown. Energy bands are calculated for the optimized structures. It is found that the intrinsic curvature of the very small nanotube greatly modifies the energy band which can no longer be well described in the tight-binding zone-folding picture. In our calculation very small nanotubes are metallic. The energy per atom fits quite well with the relation of E(R) = E0 + f/R2 even for the extreme small radius. The implications of the results on the properties of small nanotubes are discussed.

  7. 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)

    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

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

    Science.gov (United States)

    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.

  9. 一种AB PLC与Profibus DP网络通信的方法%A Solution for Communication between AB PLC and Profibus DP Network

    Institute of Scientific and Technical Information of China (English)

    李学治

    2015-01-01

    Industrial automation communication network is variousness. This paper presents a solution for communication be-tween AB PLC and Profibus DP network, introduces an example that an AB PLC system communicates with Siemens S120 drives through Profibus DP network by using MVI56-PDPMV1 module.%工业自动化通信网络具有多样性的特点, wenz对AB PLC与Profibus DP网络通信的方法进行探究,用设计实例探讨AB PLC系统通过MVI56-PDPMV1通信模块与西门子S120驱动系统构建Profibus-DP通信网络的设计与编程设置。

  10. 弹性体对ABS/PVC合金性能的影响%Effect of Elastomer on ABS/PVC Alloy

    Institute of Scientific and Technical Information of China (English)

    洪重奎; 鲁建春; 韩秀山; 华幼卿

    2000-01-01

    研究了弹性体对ABS/PVC合金性能的影响,结果表明CPE和P83与ABS/PVC有较好的相容性,能使ABS/PVC合金在保持较高软化温度的同时,极大改进材料的韧性、冲击强度由8kJ/m2分别提高到约14kJ/m2和18kJ/m2.与CPE相比,P83作为ABS/PVC合金的增韧剂效果更好,最佳用量比14%.

  11. 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.

  12. Tuberculose e o estudo molecular da sua epidemiologia

    Directory of Open Access Journals (Sweden)

    J. R. Pandolfi

    2009-01-01

    Full Text Available

    A existência de sistemas que possam diferenciar cepas de Mycobacterium tuberculosis epidemiologicamente relacionadas daquelas não relacionadas, são ferramentas importantes. A tuberculose é uma doença infecciosa, na qual técnicas de biologia molecular permitem a obtenção de informações muito difíceis ou impossíveis de serem alcançadas pela epidemiologia clássica. Um método de tipagem discriminatório, baseado no DNA genômico bacteriano, denominado RFLP (polimorfismo de comprimento de fragmentos de restrição, é empregado no estudo epidemiológico da tuberculose. Entretanto esta técnica é trabalhosa e sua substituição é uma tendência. Assim, outras seqüências têm sido usadas como marcadores epidemiológicos, como na Spoligotyping, a qual é baseada na PCR, com hibridização diferencial subseqüente dos produtos amplificados. O polimorfismo observado nas diferentes amostras é provavelmente produto de recombinação homóloga. A técnica de MIRU (mycobacterial interspersed repetitive unit é um sistema rápido e reprodutível, onde ocorre a geração de genótipos baseados no estudo de 12 loci contendo VNTRs (número variável de repetições em seqüência do complexo M. tuberculosis. Ela compara as cepas de áreas geográficas diferentes e permite o rastreamento do movimento de linhagens individuais, como no RFLP. Este tipo de abordagem permite a análise de maior número de cepas e a identificação de um número maior de focos de contaminação dentro da população, propiciando melhores maneiras de frear a transmissão da doença. Palavras-chave: Mycobacterium tuberculosis; tuberculose; epidemiologia molecular; genotipagem.

  13. 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.

  14. ESTUDO DE CASO: PARCERIA COOXUPÉ/NESPRESSO NO CERRADO MINEIRO

    Directory of Open Access Journals (Sweden)

    KANESIRO, Lidiane Aparecida

    2010-04-01

    Full Text Available This study aimed to examine the partnership between the Swiss Company Nespresso and the Cooxupé Cooperative for the production of specialty coffee in the cerrado savannah, where the ones cooperatedCooxupé are the providers of these cafes. There were applied questionnaires for some producers with objectives question to evaluate to assess the difficulties in producing specialty coffee, to meet social demands, today almost mandatory when referring to products of high quality, is, generally know what you think of this partnership between the Cooperative Cooxupé and Nespresso. A search of bibliographic data was also used for reasons of this study. The results showed that the partnership was accepted by the producers, this partnership must be maintained and enhanced and that it should clarify the producers of the importance of investing in the environment. It can be verified that this work comes to be for the improvement of the partnership among the two companies involved in the study, and to conclude that the partnership was well accepts for the suppliers, could be perfected every year.Este trabalho teve por objetivo analisar a parceria firmada entre a Cooperativa Cooxupé e a Empresa suíça Nespresso para a produção de cafés especiais no cerrado mineiro, onde os próprios cooperados daCooxupé são os fornecedores destes cafés. Foram aplicados questionários com questões objetivas aos produtores da cooperativa com o intuito de avaliar as dificuldades em produzir cafés especiais, de cumprirem exigências sócio-ambientais, hoje praticamente obrigatórias quando se refere a produtos de qualidade, e saber o que acham desta parceria entre sua Cooperativa e a Nespresso. A pesquisa de dados bibliográficos também foi usada parafundamentação deste estudo. Os resultados obtidos mostraram que a parceria foi aceita pelos produtores; que tal parceria tem que ser mantida e aprimorada e que se deve esclarecer os produtores da importância em se

  15. Investimentos Socioambientais para Posicionamento de Marca: Um Estudo Sobre Imagem Organizacional

    OpenAIRE

    Aline Eggres de Castro; Flavia Luciane Scherer

    2012-01-01

    O presente estudo tem como objetivo investigar se os Investimentos Socioambientais e demais ações de Responsabilidade Social Corporativa das empresas impactam positivamente na imagem organizacional delas perante seus consumidores. A Natura Cosméticos S.A. foi escolhida como objeto de estudo devido a sua forte atuação nas áreas social, ambiental e cultural no país. Para atingir os objetivos do estudo, foi realizada pesquisa survey com as consultoras (revendedoras de produtos) da empresa, que ...

  16. ABS/PET合金的相容化研究%Study on the Compatibility of ABS/PET Alloy

    Institute of Scientific and Technical Information of China (English)

    刘辉辉; 杜一凡; 谷志杰; 许海燕

    2014-01-01

    以苯乙烯-丙烯腈-甲基丙烯酸缩水甘油酯(SAG)和苯乙烯-丙烯腈-马来酸酐(SMA)为相容剂对丙烯腈-丁二烯-苯乙烯(ABS)/聚对苯二甲酸乙二醇酯(PET)合金进行增容.并从拉伸性能、弯曲性能、冲击性能、熔体质量流动速率(MFR)等方面对SAG和SMA的增容效果进行了比较.结果表明,含有GMA基团的SAG比含有MAH基团的SAM的增容效果更好.

  17. 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…

  18. 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

    required to minimise mAb glycoform variability. Our results suggest that the availability of glycosylation machinery relative to cellular secretory capacity may play a crucial role in mAb glycosylation. In the future, the modelling framework presented here may aid in selecting and engineering cell lines...

  19. 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

  20. 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 MOSFET

  1. Towards a fair and equitable abs regime: is Nagoya leading us in the right direction?

    NARCIS (Netherlands)

    Jonge, de B.

    2013-01-01

    A historical overview of the concept of Access and Benefit Sharing (ABS) suggests that ABS is all about compensation, i.e. a benefit sharing mechanism that provides one with compensation for allowing access to one’s resources. The principles of entitlement (based on sovereign rights) and desert (bas

  2. Prediction on Antigenic Epitope Characteristics of Bt Cry2Ab Protein in Transgenic Crops

    Institute of Scientific and Technical Information of China (English)

    Jierong GAO; Ying HE; Zehong ZOU; Ailin TAO; Yuncan AI

    2012-01-01

    Abstract [Objective] This study aimed to predict the structural characteristics of Bt Cry2Ab protein in transgenic crops with bioinformatic analysis to provide the theoreti- cal clues for design of antibody Cry2Ab. [Method] The amino acid sequence of Cry2Ab protein was searched from NCBI database. The B cell epitopes were pre- dicted with DNAStar. The binding affinity between Cry2Ab protein and MHC-II molecules was analyzed with NetMHCII 2.2 Server to predict the T cell epitopes. [Result] Prediction result suggested the potential B cell epitope of Cry2Ab locating in the region of 208-215. Analysis of the binding affinity between Cry2Ab and MHC-II molecules suggested the regions of 177-185, 299-307 and 255-263 were the po- tential T cell epitopes. Human with HLA-DRB10101 alleles and HLA-DRB10701 al- leles were more sensitive to Cry2Ab protein. [Conclusion] This study facilitates to un- derstand the structural characteristics of Cry2Ab protein and provides a new clue to improve the assessment method for potential allergenicity of genetically modified food.

  3. Electronic Brake-Force Distribution Control Methods of ABS-Equipped Vehicles During Cornering Braking

    Institute of Scientific and Technical Information of China (English)

    WANG Guo-ye; LIU Zhao-du; MA Yue-feng; QI Zhi-quan

    2007-01-01

    Based on the dynamics of ABS-equipped vehicles during cornering braking,the electronic brakeforce distribution (EBD) control methods of ABS-equipped vehicles during cornering braking are proposed.According to the dynamics and the tire model under tire adhesion limit,the stability acceptance criteria of vehicles during cornering braking are proposed.According to the stability acceptance criteria and the ABS control,the EBD control methods of ABS-equipped vehicles during cornering braking are implemented by adjusting the threshold values of tires slip independently.The vehicle states during cornering braking at two typical initial velocities of the vehicle are analyzed by the EBD control methods,whose results indicate the EBD control methods can improve the braking performances of the vehicle during cornering braking comparing with the ABS control.

  4. 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.

  5. Estudo retrospectivo da peste humana no Nordeste oriental do Brasil

    Directory of Open Access Journals (Sweden)

    Dalva A. Mello

    1970-02-01

    Full Text Available Utilizando dados do Departamento Nacional de Endemias Rurais, o autor faz um estudo retrospectivo da peste humana no Nordeste Oriental do Brasil no período de 1935-1967. Os aspectos epidemiológicos abordados foram os seguintes: morbidade, mortalidade, letalidade, "point" epidêmicos, tendência secular e variações mensais. Os coeficientes de morbidade e mortalidade variaram muito. A letalidade apresentou-se bastante alta. Dez anos de "point" epidêmicos foram registrados no periodo estudado. A análise estatística dos casos distribuídos por mês mostrou que a peste humana atinge o pcnto máximo na estação sêca. Ficou demonstrada urna variação cíclica da doença, em que aumentos e decréscimos ocorrem em períodos que variam de 6 a 12 anos.

  6. A ESCRITA NA ESCOLA: UM ESTUDO SOBRE CONFLITOS E ENCONTROS

    Directory of Open Access Journals (Sweden)

    Mary Elizabeth Cerutti-Rizzatti

    2013-07-01

    Full Text Available Este estudo discute as práticas de letramento na escola, com foco em conflitos entre letramentos dominantes e letramentos vernaculares no ensino e na aprendizagem de língua materna em espaços de vulnerabilidade social. Trata-se de uma abordagem de natureza qualitativa interpretativista (MASON, 1996, que busca responder à seguinte questão: Como se caracteriza o encontro entre letramentos dominantes e letramentos vernaculares na ação do professor com seus alunos em aulas de língua materna em espaços de vulnerabilidade social? O referencial teórico vem de obras de Street (1988, 2003, Ponzio (2010; 2010a, Bakhtin (2013 [1929]; 1998 [1975]; 2010 [1920-24], Vigotski (1997 [1987]; 2000 [1978] e outros autores. Os resultados indicam a necessidade de uma efetiva sensibilidade para letramentos vernaculares na escola, bem como o compromisso com a educação para os letramentos dominantes, requerendo de professor e alunos o exercício do olhar para universos não familiares.

  7. Simulação de Escoamentos Atmosféricos para Estudo de Parques Eólicos: Estudo comparativo dos softwares OpenFOAM e Windie

    OpenAIRE

    Faria, Ricardo Jorge Agrela

    2014-01-01

    A presente tese tem como principal objetivo a comparação entre dois software de CFD (Computer Fluid Dynamics) na simulação de escoamentos atmosféricos com vista à sua aplicação ao estudo e caracterização de parques eólicos. O software em causa são o OpenFOAM (Open Field Operation and Manipulation) - freeware open source genérico - e o Windie, ferramenta especializada no estudo de parques eólicos. Para este estudo foi usada a topografia circundante a um parque eólico situado na Grécia, do qual...

  8. Hydrogenation of AB{sub 5} and AB{sub 2} metal hydride alloys studied by in situ X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Wang, L. [Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202 (United States); BASF – Battery Materials Ovonic, 2983 Waterview Drive, Rochester Hills, MI 48309 (United States); Young, K., E-mail: kwo.young@basf.com [BASF – Battery Materials Ovonic, 2983 Waterview Drive, Rochester Hills, MI 48309 (United States); Nei, J.; Pawlik, D. [BASF – Battery Materials Ovonic, 2983 Waterview Drive, Rochester Hills, MI 48309 (United States); Ng, K.Y.S. [Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202 (United States)

    2014-12-15

    Highlights: • Hydrogenation process of an AB{sub 5} alloy and two AB{sub 2} alloys were studied by quasi in-situ XRD. • In both AB{sub 5} and AB{sub 2} metal alloy, hydrogen occupation sites on the half-plane were taken first. • In the C14/C15 mixed alloy, C14 phase is the main hydrogen storage phase with a lower equilibrium pressure. • In the C14/C15 mixed alloy, C15 phase is the catalyst hydrogen storage phase with a higher equilibrium pressure. • Small amount of C15 was hydrided first but not completed until C14 phase was fully hydrided. - Abstract: The evolution of lattice constants and abundances of metal (α) and metal hydride (β) phases during the hydrogenation process of an AB{sub 5} alloy with a CaCu{sub 5} crystal structure, an AB{sub 2} alloy with a predominating C14 structure, and a C14/C15-mixed AB{sub 2} alloy were reported. The preferred hydrogen insertion sites at different states of charge in both the α and β phases were studied based on the lattice parameter changes during hydrogenation. During the hydrogenation of the AB{sub 5} alloy, the ratio between lattice parameters a and c (a/c ratio) in the α phase decreases, stabilizes, and then decreases again while that in the β phase decreases and then stabilizes. The trends in unit cell volume changes are increasing, plateauing, and increasing again in the α phase and increasing followed by plateauing in the β phase as the hydrogenation level increases. In the C14-predominant AB{sub 2} alloy, the a/c ratio in the α phase increases at the beginning and then stabilizes while that in the β phase remains about the same and then increases during the addition of hydrogen. Moreover, the unit cell volume in the α phase increases slightly during hydrogenation, comparing to the increasing, decreasing, and then increasing trend in the β phase. In the C14/C15 mixed AB{sub 2} alloy, hydrogenation of the C15 phase starts at the beginning and promotes the hydrogenation of the C14 phase. The C14

  9. Performance Study of ABS/Graphite/NBR Thermal Conductive Composites%ABS/石墨/NBR导热复合材料性能的研究

    Institute of Scientific and Technical Information of China (English)

    傅伟宁; 张云灿; 韦亚兵; 成敏

    2013-01-01

    采用熔融共混法制备丙烯腈-丁二烯-苯乙烯共聚物(ABS)/石墨/丁腈橡胶(NBR)导热复合材料,通过热常数分析仪、同步热分析仪、扫描电子显微镜、力学性能测试等手段研究了NBR、ABS高胶粉及石墨(G)的添加量对ABS复合材料导热性能及力学性能的影响.结果表明,ABS高胶粉和NBR均能明显提高ABS的热导率和缺口冲击强度,但是丁腈胶粉的改性效果优于高胶粉.以NBR作为ABS复合材料的增韧剂,随着石墨含量的增大,增韧效果下降,ABS复合材料的热导率提高到纯ABS的5倍,热分解温度提高40℃左右,热膨胀系数下降.当ABS/G/NBR复合材料的质量比为60/15/25时,其热导率为纯ABS的2倍,缺口冲击强度达21.8 kJ/m2,明显高于纯ABS(2.6 kJ/m2).%Thermally conductive ABS/graphite/nitrile butadiene rubber (NBR) composites were prepared by melt bleding method.The effects of NBR,ABS and graphite content on the thermal conductivity and mechanical property of the ABS composites were studied respectively by the thermal constant analyzer,synchronous thermal analysis,scanning electron microscopy and mechanical properties testing means.The results showed that ABS high glue powder and NBR could increase the thermal conductivity and Notched impact strength of ABS,but NBR was more suitable as a toughening agent for ABS composite.The toughening effect decreased as the graphite content increased.Meanwhile the thermal conductivity of the ABS composite was up to five times than that of the pure ABS.The thermal decomposition temperature of the composite increased by about 40 ℃ and the thermal expansion coefficient failed.When the mass ratio of ABS/G/NBR was 60/15/25,the thermal conductivity was two times than that of pure ABS and the impact strength was up to 21.8 kJ/m2 which was larger than that of pure ABS (2.6 kJ/m2).

  10. Estudo do impacto de sistemas enterprise resource planning nas empresas e na contabilidade de gestão: evidência a partir de um estudo de caso.

    OpenAIRE

    Ribeiro, Pedro Miguel da Ponte

    2009-01-01

    Mestrade em Contabilidade Os sistemas enterprise resource planning (ERP), como o systems applications products (SAP), têm sido muito utilizados em empresas de média e grande dimensão nos últimos anos. Há vários estudos sobre o impacto destes sistemas nas empresas, na contabilidade de gestão, bem como as dificuldades da sua implementação. Neste estudo são analisados os impactos da implementação do SAP numa empresa de grande dimensão nacional. A implementação foi bem sucedida ...

  11. AB-8大孔树脂对蓝莓花色苷的纯化研究%The purification study of blueberry anthocyanin on resin AB-8

    Institute of Scientific and Technical Information of China (English)

    黄月鹏; 黄翠贤

    2012-01-01

    花色苷是一种水溶性的安全的天然色素。本论文以蓝莓花色苷提取液为原料。使用AB-8树脂对蓝莓花色苷精制工艺进行了研究。结果表明:AB-8树脂吸附流速为10mL/min,用40%乙醇洗脱,解吸流速为5mL/min。AB-8树脂饱和吸附量1.25mg/mL,树脂量是蓝莓花色苷量的3BV。蓝莓花色苷的纯度为38.1%。%Anthocyanin was a water-soluble, safe and natural pigment. Extraction of blueberry anthocyanin was used as raw material in this paper.lt was studied that technology of purifing resin AB-8 to blueberry anthocyanin. The results showed that the absorption speed of resin AB-8 was 10ml/min,the anthocyanin from blueberry was eluted with 40% ethanol at the flow rate of 5mL/min.The absorption capacity of the resin AB-8 was determined to be 1.25mg/mL. It revealed that ratio of resinAB-8 to blueberry anthocyanin solvent were 3BV. The purification of blueberry anthocyanin was 38.1%.

  12. Estudos sobre Trabalho Global: A necessidade de uma perspetiva emancipatória

    Directory of Open Access Journals (Sweden)

    Peter Waterman

    2013-04-01

    Full Text Available O presente artigo faz uma avaliação crítica dos chamados “Novos Estudos sobre Trabalho Global” com base nos seus parâmetros socioliberais, concentrando‑se em espaços, locais ou aspetos supranacionais ou globais. Advoga a necessidade de uma perspetiva emancipatória nos “Estudos sobre Trabalho Global”, apontando para algumas das fontes teóricas em que se pode basear.

  13. The wonderful complexity of the Mira AB system

    CERN Document Server

    Ramstedt, S; Vlemmings, W H T; Maercker, M; Montez, R; Baudry, A; De Beck, E; Lindqvist, M; Olofsson, H; Humphreys, E M L; Jorissen, A; Kerschbaum, F; Mayer, A; Wittkowski, M; Cox, N L J; Lagadec, E; Leal-Ferreira, M L; Paladini, C; Pérez-Sánchez, A; Sacuto, S

    2014-01-01

    We have mapped the CO(3-2) line emission around the Mira AB system at 0.5 resolution using the Atacama Large Millimeter/submillimeter Array (ALMA). The CO map shows amazing complexity. The circumstellar gas has been shaped by different dynamical actors during the evolution of the system and several morphological components can be identified. The companion is marginally resolved in continuum emission and is currently at 0.487$\\pm$0.006 separation. In the main line component, centered on the stellar velocity, spiral arcs around Mira A are found. The spiral appears to be relatively flat and oriented in the orbital plane. An accretion wake behind the companion is clearly visible and the projected arc separation is of order 5''. In the blue wing of the line emission, offset from the main line, several large ($\\sim$5-10''), opposing arcs are found. We tentatively suggest that this structure is created by the wind of Mira B blowing a bubble in the expanding envelope of Mira A.

  14. Histopathological Study of Trabeculum after Excimer Laser Trabeculectomy ab Interno

    Institute of Scientific and Technical Information of China (English)

    Shengsong Huang; Minbin Yu; Guangqiang Feng; Ping Zhang; Changyu Qiu

    2001-01-01

    Purpose: To study the clinical manifestations and histopathologic changes of trabeculum after excimer laser trabeculectomy ab interno (ELT), and to investigate the mechanisms of ELT in reducing intraocular pressure. Methods : ELT was performed on ten rabbit eves and postoperative responses were documented. Comeoscleral tissue samples were harvested consecutively each week until the 5th postoperative week and these samples were examined under light and electrical microscopy. Results: Mild stimulation signs were present postoperatix'ely in nine of ten eyes, but no serious complications were experienced. Obvious inflammation was observed in one rabbit eye as a result of iris damage during the surgical manipulations. Local kactures on the trabecular meshwork and openings into Schlemm' s canal were detected in all tissue samples under light microscope. Mitochondria were found to be turgescent and dilated like vacuoles and endoplasmic reticula were found to be dilated under electrical microscope in the early postoperative period. Later, all trabecular cells returned normal and no fihroblast cells were ever detected. Conclusions: Permanent openings through trabecular meshwork into the inner wall of Schlemm's canal can be created with ELT. The outflow resistance of aqueous humor can be reduced with these openings and intraocular pressure can be controlled thereafter. Eye Science 2001; 17:11 ~ 15.

  15. Exploring the free energy surface using ab initio molecular dynamics.

    Science.gov (United States)

    Samanta, Amit; Morales, Miguel A; Schwegler, Eric

    2016-04-28

    Efficient exploration of configuration space and identification of metastable structures in condensed phase systems are challenging from both computational and algorithmic perspectives. In this regard, schemes that utilize a set of pre-defined order parameters to sample the relevant parts of the configuration space [L. Maragliano and E. Vanden-Eijnden, Chem. Phys. Lett. 426, 168 (2006); J. B. Abrams and M. E. Tuckerman, J. Phys. Chem. B 112, 15742 (2008)] have proved useful. Here, we demonstrate how these order-parameter aided temperature accelerated sampling schemes can be used within the Born-Oppenheimer and the Car-Parrinello frameworks of ab initio molecular dynamics to efficiently and systematically explore free energy surfaces, and search for metastable states and reaction pathways. We have used these methods to identify the metastable structures and reaction pathways in SiO2 and Ti. In addition, we have used the string method [W. E, W. Ren, and E. Vanden-Eijnden, Phys. Rev. B 66, 052301 (2002); L. Maragliano et al., J. Chem. Phys. 125, 024106 (2006)] within the density functional theory to study the melting pathways in the high pressure cotunnite phase of SiO2 and the hexagonal closed packed to face centered cubic phase transition in Ti. PMID:27131525

  16. Ab initio no-core solutions for $^6$Li

    CERN Document Server

    Shin, Ik Jae; Maris, Pieter; Vary, James P; Forssén, Christian; Rotureau, Jimmy; Michel, Nicolas

    2016-01-01

    We solve for properties of $^6$Li in the ab initio No-Core Full Configuration approach and we separately solve for its ground state and $J^{\\pi}=2_{2}^{+}$ resonance with the Gamow Shell Model in the Berggren basis. We employ both the JISP16 and chiral NNLO$_{opt}$ realistic nucleon-nucleon interactions and investigate the ground state energy, excitation energies, point proton root-mean-square radius and a suite of electroweak observables. We also extend and test methods to extrapolate the ground state energy, point proton root-mean-square radius, and electric quadrupole moment. We attain improved estimates of these observables in the No-Core Full Configuration approach by using basis spaces up through N$_{max}$=18 that enable more definitive comparisons with experiment. Using the Density Matrix Renormalization Group approach with the JISP16 interaction, we find that we can significantly improve the convergence of the Gamow Shell Model treatment of the $^6$Li ground state and $J^{\\pi}=2_{2}^{+}$ resonance by ...

  17. Ab initio evaluations of the He solubility in liquid Li

    Energy Technology Data Exchange (ETDEWEB)

    Sedano, Luis A. [EURATOM-CIEMAT Assoc., Materials for Fusion Program, Bd. 43 P0.04, Avda. Complutense 22, 28040 Madrid (Spain)]. E-mail: luis.sedano@ciemat.es; Hassanein, Ahmed [Argonne Nat. Lab, 9700 South Class Av., Argonne, IL (United States)]. E-mail: hassanein@anl.gov; Sanz, Javier [ETSII-UNED, c/Juan del Rosal, 12, 28040 Madrid (E) (Spain)]. E-mail: jsanz@ind.UNED.es

    2005-11-15

    Modified embedding atom methods (MEAM) are developed to have predictions of the partial molar heat of solution (-H{sub s}) by direct simulation of metal cohesion, He-metal and He-He interaction. Transitions from crystalline Li to configurations, having the liquid Li structure's factors (h-bar (q)), are simulated ab initio. Once h-bar (q) reproduced, He atoms are added, one by one, to the Li system. Parallel lines for each case, with slopes clearly independent on the number of He atoms in the system, are obtained for energy versus pressure at given temperatures. Average differences between two adjacent parallels at zero pressure, once kinetic energy of the system discounted, represents the energy gained by an He atom when added to the Li system, related to the solution energy -H{sub s}. The molar excess entropy of gas in solution (S-bar {sub l}{sup ex}) is previously evaluated following diverse fundamental approaches: a 'thermodynamic liquid-hole' (TL-H) model for alkali liquids and a statistical-mechanics (Neff and McQuarrie's) model (SMM). Between 600 and 900 deg. C, a typical range of interest for the use of Li in fusion technology, the computed values for the (He) Henry's constant in Li range from 8x10{sup -14} to 10{sup -13} at. fr. Pa{sup -1}.

  18. Ab initio simulations of pseudomorphic silicene and germanene bidimensional heterostructures

    Science.gov (United States)

    Debernardi, Alberto; Marchetti, Luigi

    2016-06-01

    Among the novel two-dimensional (2D) materials, silicene and germanene, which are two honeycomb crystal structures composed of a monolayer of Si and Ge, respectively, have attracted the attention of material scientists because they combine the advantages of the new 2D ultimate-scaled electronics with their compatibility with industrial processes presently based on Si and Ge. We envisage pseudomorphic lateral heterostructures based on ribbons of silicene and germanene, which are the 2D analogs of conventional 3D Si/Ge superlattices and quantum wells. In spite of the considerable lattice mismatch (˜4 % ) between free-standing silicene and germanene, our ab initio simulations predict that, considering striped 2D lateral heterostructures made by alternating silicene and germanene ribbons of constant width, the silicene/germanene junction remains pseudomorphic—i.e., it maintains lattice-matched edges—up to critical ribbon widths that can reach some tens of nanometers. Such critical widths are one order of magnitude larger than the critical thickness measured in 3D pseudomorphic Si/Ge heterostructures and the resolution of state-of-the-art lithography, thus enabling the possibility of lithography patterned silicene/germanene junctions. We computed how the strain produced by the pseudomorphic growth modifies the crystal structure and electronic bands of the ribbons, providing a mechanism for band-structure engineering. Our results pave the way for lithography patterned lateral heterostructures that can serve as the building blocks of novel 2D electronics.

  19. Ab initio studies of phoshorene island single electron transistor.

    Science.gov (United States)

    Ray, S J; Venkata Kamalakar, M; Chowdhury, R

    2016-05-18

    Phosphorene is a newly unveiled two-dimensional crystal with immense potential for nanoelectronic and optoelectronic applications. Its unique electronic structure and two dimensionality also present opportunities for single electron devices. Here we report the behaviour of a single electron transistor (SET) made of a phosphorene island, explored for the first time using ab initio calculations. We find that the band gap and the charging energy decrease monotonically with increasing layer numbers due to weak quantum confinement. When compared to two other novel 2D crystals such as graphene and MoS2, our investigation reveals larger adsorption energies of gas molecules on phosphorene, which indicates better a sensing ability. The calculated charge stability diagrams show distinct changes in the presence of an individual molecule which can be applied to detect the presence of different molecules with sensitivity at a single molecular level. The higher charging energies of the molecules within the SET display operational viability at room temperature, which is promising for possible ultra sensitive detection applications. PMID:27093536

  20. Ab initio studies of phosphorene island single electron transistor

    Science.gov (United States)

    Ray, S. J.; Venkata Kamalakar, M.; Chowdhury, R.

    2016-05-01

    Phosphorene is a newly unveiled two-dimensional crystal with immense potential for nanoelectronic and optoelectronic applications. Its unique electronic structure and two dimensionality also present opportunities for single electron devices. Here we report the behaviour of a single electron transistor (SET) made of a phosphorene island, explored for the first time using ab initio calculations. We find that the band gap and the charging energy decrease monotonically with increasing layer numbers due to weak quantum confinement. When compared to two other novel 2D crystals such as graphene and MoS2, our investigation reveals larger adsorption energies of gas molecules on phosphorene, which indicates better a sensing ability. The calculated charge stability diagrams show distinct changes in the presence of an individual molecule which can be applied to detect the presence of different molecules with sensitivity at a single molecular level. The higher charging energies of the molecules within the SET display operational viability at room temperature, which is promising for possible ultra sensitive detection applications.

  1. Ab initio calculation of double ionization of atoms

    Energy Technology Data Exchange (ETDEWEB)

    Serov, V. V., E-mail: vladislav.serov@mail.ru [Saratov State University, Department of Theoretical Physics (Russian Federation)

    2013-02-15

    The Solov'ev-Vinitsky method was used to perform an ab initio calculation of the triple-differential cross section for the double single-photon photoionization of helium for the case of equal emitted-electron energies. A Gaussian width {gamma} describing angular electron-electron correlations at the total electron energy E taking values in range between 0.1 and 100 eV was obtained for this cross section. The results agree with available experimental data, but they raise a doubt as to whether the well-known Wannier law {gamma} {proportional_to} E{sup 1/4} is applicable at experimentally accessible energies. The Gaussian width {gamma} was investigated as a function of the total emitted-electron energy for targets that have a strongly asymmetric configuration of the initial state-specifically, a negative atomic-hydrogen ion H{sup -} and heliumin the 1s2s{sup 1}S and 1s3s{sup 1}S excited states. It was found that this function, {gamma}(E), had a maximum at low energies. It was also shown that, at low energies, the dependence of the double-differential cross section on the angle between the emitted-electron momenta for the targets indicated above differed substantially from the Gaussian dependence, featuring maxima whose number was equal to the number of radial nodes in the initial state. This opens new possibilities for a qualitative analysis of the electron structure of targets.

  2. 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.

  3. Rational design of electrolyte components by ab initio calculations

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Patrik; Jacobsson, Per [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden)

    2006-02-28

    This paper is a small review of the use of computer simulations and especially the use of standard quantum-mechanical ab initio electronic structure calculations to rationally design and investigate different choices of chemicals/systems for lithium battery electrolytes. Covered systems and strategies to enhance the performance of electrolytes will range from assisting the interpretation of vibrational spectroscopy experiments over development of potentials for molecular dynamics simulations, to the design of new lithium salts and the lithium ion coordination in liquid, polymer, and gel polymer electrolytes. Examples of studied properties include the vibrational spectra of anions and ion pairs to characterize the nature and extent of the interactions present, the lithium ion affinities of anions, important for the salt solvation and the ability to provide a high concentration of charge carriers, the HOMO energies of the anions to estimate the stability versus oxidation, the anion volumes that correlate to the anion mobility, the lithium ion coordination and dynamics to reveal the limiting steps of lithium ion transport, etc. (author)

  4. Volumic omit maps in ab initio dual-space phasing.

    Science.gov (United States)

    Oszlányi, Gábor; Sütő, András

    2016-07-01

    Alternating-projection-type dual-space algorithms have a clear construction, but are susceptible to stagnation and, thus, inefficient for solving the phase problem ab initio. To improve this behaviour new omit maps are introduced, which are real-space perturbations applied periodically during the iteration process. The omit maps are called volumic, because they delete some predetermined subvolume of the unit cell without searching for atomic regions or analysing the electron density in any other way. The basic algorithms of positivity, histogram matching and low-density elimination are tested by their solution statistics. It is concluded that, while all these algorithms based on weak constraints are practically useless in their pure forms, appropriate volumic omit maps can transform them to practically useful methods. In addition, the efficiency of the already useful reflector-type charge-flipping algorithm can be further improved. It is important that these results are obtained by using non-sharpened structure factors and without any weighting scheme or reciprocal-space perturbation. The mathematical background of volumic omit maps and their expected applications are also discussed. PMID:27357850

  5. A coupled "AB" system: Rogue waves and modulation instabilities

    Science.gov (United States)

    Wu, C. F.; Grimshaw, R. H. J.; Chow, K. W.; Chan, H. N.

    2015-10-01

    Rogue waves are unexpectedly large and localized displacements from an equilibrium position or an otherwise calm background. For the nonlinear Schrödinger (NLS) model widely used in fluid mechanics and optics, these waves can occur only when dispersion and nonlinearity are of the same sign, a regime of modulation instability. For coupled NLS equations, rogue waves will arise even if dispersion and nonlinearity are of opposite signs in each component as new regimes of modulation instability will appear in the coupled system. The same phenomenon will be demonstrated here for a coupled "AB" system, a wave-current interaction model describing baroclinic instability processes in geophysical flows. Indeed, the onset of modulation instability correlates precisely with the existence criterion for rogue waves for this system. Transitions from "elevation" rogue waves to "depression" rogue waves are elucidated analytically. The dispersion relation as a polynomial of the fourth order may possess double pairs of complex roots, leading to multiple configurations of rogue waves for a given set of input parameters. For special parameter regimes, the dispersion relation reduces to a cubic polynomial, allowing the existence criterion for rogue waves to be computed explicitly. Numerical tests correlating modulation instability and evolution of rogue waves were conducted.

  6. Atmospheric Characterization of the Hot Jupiter Kepler-13Ab

    CERN Document Server

    Shporer, Avi; Knutson, Heather A; Szabo, Gyula M; Zhao, Ming; Burrows, Adam; Fortney, Jonathan; Agol, Eric; Cowan, Nicolas B; Desert, Jean-Michel; Howard, Andrew W; Isaacson, Howard; Lewis, Nikole A; Showman, Adam P; Todorov, Kamen O

    2014-01-01

    (abridged) Kepler-13Ab (= KOI-13.01) is one of very few known short-period (1.76 day) transiting planets orbiting a bright A-type star. The availability of Kepler data allows a measurement of the planet's occultation (secondary eclipse) and orbital phase curve, which we combine with occultations observed by Spitzer at 3.6 micron and 4.5 micron and a ground-based occultation observation in the $Ks$ band (2.1 micron). For the day-side hemisphere we derive a temperate of 2,750 $\\pm$ 160 K as the effective temperature of a black body that will show the same occultation depths, and a high geometric albedo $A_g$ = 0.33$^{+0.04}_{-0.06}$. Comparing the occultation depths with one-dimensional planetary atmosphere models suggests the presence of an atmospheric temperature inversion. The Kepler mid-occultation time measured here is 34.0 $\\pm$ 6.9 s earlier than expected based on the mid-transit time reported in the literature and the expected time delay due to light travel time. This could be due to a small orbital ecc...

  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. Engineering Room-temperature Superconductors Via ab-initio Calculations

    Science.gov (United States)

    Gulian, Mamikon; Melkonyan, Gurgen; Gulian, Armen

    The BCS, or bosonic model of superconductivity, as Little and Ginzburg have first argued, can bring in superconductivity at room temperatures in the case of high-enough frequency of bosonic mode. It was further elucidated by Kirzhnitset al., that the condition for existence of high-temperature superconductivity is closely related to negative values of the real part of the dielectric function at finite values of the reciprocal lattice vectors. In view of these findings, the task is to calculate the dielectric function for real materials. Then the poles of this function will indicate the existence of bosonic excitations which can serve as a "glue" for Cooper pairing, and if the frequency is high enough, and the dielectric matrix is simultaneously negative, this material is a good candidate for very high-Tc superconductivity. Thus, our approach is to elaborate a methodology of ab-initio calculation of the dielectric function of various materials, and then point out appropriate candidates. We used the powerful codes (TDDF with the DP package in conjunction with ABINIT) for computing dielectric responses at finite values of the wave vectors in the reciprocal lattice space. Though our report is concerned with the particular problem of superconductivity, the application range of the data processing methodology is much wider. The ability to compute the dielectric function of existing and still non-existing (though being predicted!) materials will have many more repercussions not only in fundamental sciences but also in technology and industry.

  10. The Solar-System-Scale Disk Around AB Aurigae

    CERN Document Server

    Oppenheimer, Ben R; Hinkley, Sasha; Zimmerman, Neil; Sivaramakrishnan, Anand; Soummer, Remi; Kuhn, Jeffrey; Graham, James R; Perrin, Marshall; Lloyd, James P; Roberts, Lewis C Jr; Harrington, David M

    2008-01-01

    The young star AB Aurigae is surrounded by a complex combination of gas-rich and dust dominated structures. The inner disk which has not been studied previously at sufficient resolution and imaging dynamic range seems to contain very little gas inside a radius of least 130 astronomical units (AU) from the star. Using adaptive-optics coronagraphy and polarimetry we have imaged the dust in an annulus between 43 and 302 AU from the star, a region never seen before. An azimuthal gap in an annulus of dust at a radius of 102 AU, along with a clearing at closer radii inside this annulus, suggests the formation of at least one small body at an orbital distance of about 100 AU. This structure seems consistent with crude models of mean motion resonances, or accumulation of material at two of the Lagrange points relative to the putative object and the star. We also report a low significance detection of a point source in this outer annulus of dust. This source may be an overdensity in the disk due to dust accreting onto...

  11. The Hydration Structure of Carbon Monoxide by Ab Initio Methods

    CERN Document Server

    Awoonor-Williams, Ernest

    2016-01-01

    The solvation of carbon monoxide (CO) in liquid water is important for understanding its toxicological effects and biochemical roles. In this paper, we use ab initio molecular dynamics (AIMD) and CCSD(T)-F12 calculations to assess the accuracy of the Straub and Karplus molecular mechanical (MM) model for CO(aq). The CCSD(T)-F12 CO--H2O potential energy surfaces show that the most stable structure corresponds to water donating a hydrogen bond to the C center. The MM-calculated surface it incorrectly predicts that the O atom is a stronger hydrogen bond acceptor than the C atom. The AIMD simulations indicate that CO is solvated like a hydrophobic solute, with very limited hydrogen bonding with water. The MM model tends to overestimate the degree of hydrogen bonding and overestimates the atomic radius of the C atom. The calculated Gibbs energy of hydration is in good agreement with experiment (9.3 kJ/mol calc. vs 10.7 kJ/mol exptl.). The calculated diffusivity of CO(aq) in TIP3P-model water was 5.19 x 10-5 cm2/s ...

  12. Proteolytic Activation of Bacillus thuringiensis Cry2Ab through a Belt-and-Braces Approach.

    Science.gov (United States)

    Xu, Lian; Pan, Zhi-Zhen; Zhang, Jing; Liu, Bo; Zhu, Yu-Jing; Chen, Qing-Xi

    2016-09-28

    Proteolytic processing of Bacillus thuringiensis (Bt) crystal toxins by insect midgut proteases plays an essential role in their insecticidal toxicities against target insects. In the present study, proteolysis of Bt crystal toxin Cry2Ab by Plutella xylostella L. midgut proteases (PxMJ) was evaluated. Both trypsin and chymotrypsin were identified involving the proteolytic activation of Cry2Ab and cleaving Cry2Ab at Arg(139) and Leu(144), respectively. Three Cry2Ab mutants (R139A, L144A, and R139A-L144A) were constructed by replacing residues Arg(139), Leu(144), and Arg(139)-Leu(144) with alanine. Proteolysis assays revealed that mutants R139A and L144A but not R139A-L144A could be cleaved into 50 kDa activated toxins by PxMJ. Bioassays showed that mutants R139A and L144A were highly toxic against P. xylostella larvae, while mutant R139A-L144A was almost non-insecticidal. Those results demonstrated that proteolysis by PxMJ was associated with the toxicity of Cry2Ab against P. xylostella. It also revealed that either trypsin or chymotrypsin was enough to activate Cry2Ab protoxin. This characteristic was regarded as a belt-and-braces approach and might contribute to the control of resistance development in target insects. Our studies characterized the proteolytic processing of Cry2Ab and provided new insight into the activation of this Bt toxin.

  13. A test of Automatic Blowing snow Station (ABS) in the French Alps

    Science.gov (United States)

    Ito, Yoichi; Naaim-Bouvet, Florence; Nishimura, Kouichi; Bellot, Hervé; Fontaine, Firmin

    2015-04-01

    Blowing snow is a significant factor to estimate snow distribution in alpine, Arctic and Antarctic regions. The Snow Particle Counter (SPC) is well used for mass flux measurement of the blowing snow, however, the SPC deployment is not always possible for automatic observation under harsh conditions. Recently Automatic Blowing snow Station (ABS), which is a simpler device than the SPC, have been developed in Japan. We installed the ABS system with the SPCs at the Lac Blanc Pass in the French Alps (2700 m a.s.l.) to examine the relationship between the ABS output and snow particle mass flux. The ABS worked well, without problems, for the entire 4-month period in the winter 2014. The ABS output was converted to mass flux using wind-dependent power function which obtained from calibration procedure in a cold wind-tunnel. The mass flux obtained from the ABS showed a good agreement with the SPC, particularly around the peak of blowing snow event. Based on tests under controlled (cold wind-tunnel) and field conditions, we conclude that the ABS is suitable for practical use.

  14. UM ESTUDO SOBRE CLIMA ORGANIZACIONAL NO AMBIENTE HOSPITALAR

    Directory of Open Access Journals (Sweden)

    VIGNERON, D. M. S.

    2015-09-01

    Full Text Available Toda organização é composta por recursos materiais e por capital humano, e ambos estão intimamente ligados. Para melhor aproveitamento dos colaboradores, torna-se imprescindível ter em mente os conceitos de gestão de pessoas, sabendo-se que colaboradores satisfeitos são mais produtivos e levam à empresa ao sucesso. Segundo Bispo (2006 a pesquisa de clima organizacional é a mais objetiva e segura dentre todas as diversas ferramentas que são criadas constantemente para avaliar o nível de relacionamento entre empresas e colaboradores, podendo identificar problemas reais na gestão de Recursos Humanos. Este estudo tem por objetivo geral avaliar o Clima Organizacional em um Hospital Público do município de Campos dos Goytacazes, RJ. De forma específica, além de realizar um diagnóstico do grau de motivação dos colaboradores dentro do hospital através de uma pesquisa de Clima Organizacional, busca-se também conhecer o comportamento dos entrevistados em relação às variáveis que interferem no clima. Portanto este estudo apresenta-se a seguinte problemática: Quais os fatores que influenciam no Clima Organizacional do Hospital Público X? Para desenvolver este trabalho foi realizada uma pesquisa do tipo exploratória por meio do levantamento bibliográfico e estudo de caso que proporcionou maior familiaridade com o problema e com o objetivo proposto. A pesquisa foi aplicada na emergência de um hospital público na cidade de Campos dos Goytacazes – RJ, referência em atendimentos de emergência. O questionário para avaliação do Clima Organizacional foi adaptado de Santos et al. (2012 e dividido em duas partes. A primeira parte com perguntas referentes ao perfil dos respondentes e a segunda com perguntas relacionadas ao trabalho. Foram avaliados 42 colaboradores da emergência, com idade entre 18 e 60 anos, de ambos os sexos. Quanto ao perfil dos colaboradores constatou que a maioria tem entre 06 e 18 anos de empresa, revelando

  15. On Maintenance of Electronic Anti-lock Braking System (ABS)%电控防抱死制动系统(ABS)的检修

    Institute of Scientific and Technical Information of China (English)

    吴继刚

    2015-01-01

    随着汽车制动系统技术的不断改进,电控防抱死ABS系统已逐渐成为汽车的标准配件,了解电控防抱死ABS系统的维修技术对汽车制动系统的维修和故障诊断工作十分重要.ABS主要部件的检修包括:ABS ECU的检修、轮速传感器的检修、液压控制装置的检修、制动压力调节器的检修.%With the continuous improvement of technology related to automobile braking system,electronic anti-lock ABS system has gradually become one of the standard fittings of automobile,to learn maintenance technology related to electronic anti-lock ABS system is of great importance to maintain and fault diagnosing of automobile braking system.The maintenance for main components of ABS includes the maintenance for ABS ECU,wheel speed sensor,hydraulic controlled devices,braking pressure regulator,etc.

  16. 基于弛豫型铁电三元共聚物聚(偏氟乙烯-三氟乙烯-氯代偏氟乙烯)热释电性能的能量采集研究%Giant Energy Harvesting by Pyroelectric Effect in Relaxor Ferroelectric Terpolymer Poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene)

    Institute of Scientific and Technical Information of China (English)

    朱红英; 王相虎; 王致杰; 王珺; 郭群超

    2016-01-01

    研究了利用弛豫型铁电三元聚合物薄膜P( VDF-TrFE-CFE)的热释电性质,以温度波动作为初始能量形式进行热电能量的采集。由于该聚合物薄膜在发生由温度变化诱导的纳米极性区极化机制转换时,介电常数表现出明显的非线性变化,所以可以结合Ericsson循环实现热电能量采集。实验结果显示,最佳能量采集温度区间为20~-20℃,利用不同温度下的单极性电滞回线进行Ericsson循环模拟,两种模拟方式分别实现能量采集最大值和最小值,并从微观角度给出了两种模式的解释。同时研究了温度波动和外加电场对能量采集的影响。在外加电场100 kV·mm-1、温度波动为40℃的情况下,能量采集值达到3483 mJ·cm-3。与单晶材料相比,能量采集值提高了10倍。当工作温度降低至室温时,材料具有柔性,在能量采集方面具有应用潜力。%Energy harvesting was investigated in relaxor ferroelectric terpolymer P( VDF-TrFE-CFE) by pyroelectric effect. Original energy was the temperature fluctuations. Due to the non-linear die-lectric property in the vicinity of polarization mechanism transition of nanopolar regions, we can har-vest energy by operating Ericsson cycle. Experimental results show that the best energy harvesting temperature range is from 20 to -20 ℃. Ericssion cycle was simulated using the unipolar cycle at different temperatures. Two modes of energy harvesting were presented and analyzed:modeⅠmaxi-mizing and modeⅡminimizing harvested energy, modeⅠis idealized, by applying a low voltage, the harvested energy can reach nearly maximum. The explanation of the two modes was given from the view of microstructure. Temperature and electric field dependence was also given, at 100 kV· mm-1 , temperature from 20 to -20 ℃, giant energy can be harvested around 3 483 mJ · cm-3 . Compared with the single crystals, the advantages, such as the harvested energy increased by 10 times, working

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

    OpenAIRE

    Zhang, Lingli; Nguyen, Hoang Chuong; Chipot, Ludovic; Piotrowski, Emilie; Bertrand, Claire; Thibessard, Annabelle; Leblond, Pierre

    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 pu...

  18. AdnAB: a new DSB-resecting motor–nuclease from mycobacteria

    OpenAIRE

    Sinha, Krishna Murari; Unciuleac, Mihaela-Carmen; Glickman, Michael S.; Shuman, Stewart

    2009-01-01

    The resection of DNA double-strand breaks (DSBs) in bacteria is a motor-driven process performed by a multisubunit helicase–nuclease complex: either an Escherichia coli-type RecBCD enzyme or a Bacillus-type AddAB enzyme. Here we identify mycobacterial AdnAB as the founder of a new family of heterodimeric helicase–nucleases with distinctive properties. The AdnA and AdnB subunits are each composed of an N-terminal UvrD-like motor domain and a C-terminal nuclease module. The AdnAB ATPase is trig...

  19. Studies on Synthesis and Antitumor Activity of Phosphorylated Achyranthes bidentata Polysaccharide (P-AbPS)

    Institute of Scientific and Technical Information of China (English)

    CHEN,Xiao-Ming(陈晓明); ZHANG,Jian(张健); TIAN,Geng-Yuan(田庚元)

    2002-01-01

    The synthesis of phosphorylated Achyranthes bidentata polysaccharide (P-AbPS) was reported based on different strategies.The P-AbPS with high degree of substitution (D.S. >0.5) was obtained when phosphorus oxychloride (POCl3) was used as a phosphorylating agent and trimethyl phosphate-pyridine or dimethyl formamide was used as solvent. The influences of different solvents and reaction conditins were discussed. Thepharmacology assay shows that P-AbPS possesses antitumor activity against sarcoma 180 and Lewis lung carner in mice.

  20. 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...

  1. PirAB toxin from Photorhabdus asymbiotica as a larvicide against dengue vectors.

    Science.gov (United States)

    Ahantarig, Arunee; Chantawat, Nantarat; Waterfield, Nicholas R; ffrench-Constant, Richard; Kittayapong, Pattamaporn

    2009-07-01

    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 PirA plus PirB, has any impact on biological control efficacy needs further investigation.

  2. STUDIES ON FLAME-RETARDANT PC/ABS MULTIPLE-ELEMENT ALLOY

    Institute of Scientific and Technical Information of China (English)

    Ying Quan; Ming-shah Yang; Qing Yah

    2001-01-01

    The preparation technology of flame-retardant PC/ABS alloys was studied in this paper. Using a high-efficiency flame retardant system and by means of multiple-ingredient compatibilizing, PC/ABS alloys with excellent impact strength and flame retardant property were prepared. The experimental results showed that by using PS-g-MAH and SMA as synergistic compatibilizers, the notched Izod impact strength and flammability of PC/ABS alloy obtained in the present work can be up to 175 J/m and UL-94 V0, respectively.

  3. Emergence of rotational bands in ab initio no-core configuration interaction calculations

    CERN Document Server

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

    2015-01-01

    Rotational bands have been observed to emerge in ab initio no-core configuration interaction (NCCI) calculations for p-shell nuclei, as evidenced by rotational patterns for excitation energies, electromagnetic moments, and electromagnetic transitions. We investigate the ab initio emergence of nuclear rotation in the Be isotopes, focusing on 9Be for illustration, and make use of basis extrapolation methods to obtain ab initio predictions of rotational band parameters for comparison with experiment. We find robust signatures for rotational motion, which reproduce both qualitative and quantitative features of the experimentally observed bands.

  4. Performance of the molecular Alere I influenza A&B test compared to that of the xpert flu A/B assay.

    Science.gov (United States)

    Chapin, Kimberle C; Flores-Cortez, Estefany J

    2015-02-01

    Data on the performance of rapid molecular point-of-care use platforms for diagnosis of influenza are lacking. We validated nasopharyngeal (NP) flocked specimens in universal transport medium (UTM) and evaluated the clinical sensitivity and specificity of the Alere i influenza A&B test compared to those of the Xpert flu A/B assay. The Alere i influenza A&B test had an overall sensitivity and specificity of 93.8% and 62.5% for influenza A, respectively, and of 91.8% and 53.6% for influenza B, respectively. The poor specificity was due to influenza virus samples determined positive for both type A and B. PMID:25502527

  5. Performance of the Molecular Alere i Influenza A&B Test Compared to That of the Xpert Flu A/B Assay

    Science.gov (United States)

    Flores-Cortez, Estefany J.

    2014-01-01

    Data on the performance of rapid molecular point-of-care use platforms for diagnosis of influenza are lacking. We validated nasopharyngeal (NP) flocked specimens in universal transport medium (UTM) and evaluated the clinical sensitivity and specificity of the Alere i influenza A&B test compared to those of the Xpert flu A/B assay. The Alere i influenza A&B test had an overall sensitivity and specificity of 93.8% and 62.5% for influenza A, respectively, and of 91.8% and 53.6% for influenza B, respectively. The poor specificity was due to influenza virus samples determined positive for both type A and B. PMID:25502527

  6. Atmospheric characterization of the hot Jupiter Kepler-13Ab

    International Nuclear Information System (INIS)

    Kepler-13Ab (= KOI-13.01) is a unique transiting hot Jupiter. It is one of very few known short-period planets orbiting a hot A-type star, making it one of the hottest planets currently known. The availability of Kepler data allows us to measure the planet's occultation (secondary eclipse) and phase curve in the optical, which we combine with occultations observed by warm Spitzer at 4.5 μm and 3.6 μm and a ground-based occultation observation in the Ks band (2.1 μm). We derive a day-side hemisphere temperature of 2750 ± 160 K as the effective temperature of a black body showing the same occultation depths. Comparing the occultation depths with one-dimensional planetary atmosphere models suggests the presence of an atmospheric temperature inversion. Our analysis shows evidence for a relatively high geometric albedo, A g = 0.33−0.06+0.04. While measured with a simplistic method, a high A g is supported also by the fact that the one-dimensional atmosphere models underestimate the occultation depth in the optical. We use stellar spectra to determine the dilution, in the four wide bands where occultation was measured, due to the visual stellar binary companion 1.''15 ± 0.''05 away. The revised stellar parameters measured using these spectra are combined with other measurements, leading to revised planetary mass and radius estimates of Mp = 4.94-8.09 M J and Rp = 1.406 ± 0.038 R J. Finally, we measure a Kepler midoccultation time that is 34.0 ± 6.9 s earlier than expected based on the midtransit time and the delay due to light-travel time and discuss possible scenarios.

  7. Atmospheric Characterization of the Hot Jupiter Kepler-13Ab

    Science.gov (United States)

    Shporer, Avi; O'Rourke, Joseph G.; Knutson, Heather A.; Szabó, Gyula M.; Zhao, Ming; Burrows, Adam; Fortney, Jonathan; Agol, Eric; Cowan, Nicolas B.; Desert, Jean-Michel; Howard, Andrew W.; Isaacson, Howard; Lewis, Nikole K.; Showman, Adam P.; Todorov, Kamen O.

    2014-06-01

    Kepler-13Ab (= KOI-13.01) is a unique transiting hot Jupiter. It is one of very few known short-period planets orbiting a hot A-type star, making it one of the hottest planets currently known. The availability of Kepler data allows us to measure the planet's occultation (secondary eclipse) and phase curve in the optical, which we combine with occultations observed by warm Spitzer at 4.5 μm and 3.6 μm and a ground-based occultation observation in the Ks band (2.1 μm). We derive a day-side hemisphere temperature of 2750 ± 160 K as the effective temperature of a black body showing the same occultation depths. Comparing the occultation depths with one-dimensional planetary atmosphere models suggests the presence of an atmospheric temperature inversion. Our analysis shows evidence for a relatively high geometric albedo, A g = 0.33^{+0.04}_{-0.06}. While measured with a simplistic method, a high A g is supported also by the fact that the one-dimensional atmosphere models underestimate the occultation depth in the optical. We use stellar spectra to determine the dilution, in the four wide bands where occultation was measured, due to the visual stellar binary companion 1.''15 ± 0.''05 away. The revised stellar parameters measured using these spectra are combined with other measurements, leading to revised planetary mass and radius estimates of Mp = 4.94-8.09 M J and Rp = 1.406 ± 0.038 R J. Finally, we measure a Kepler midoccultation time that is 34.0 ± 6.9 s earlier than expected based on the midtransit time and the delay due to light-travel time and discuss possible scenarios.

  8. Ab initio no-core shell model with continuum

    Science.gov (United States)

    Navratil, Petr

    2008-04-01

    The ab initio no-core shell model (NCSM) is a many-body approach to nuclear structure of light nuclei. The NCSM adopts an effective interaction theory to transform fundamental inter-nucleon interactions into effective interactions for a specified nucleus in a selected harmonic oscillator basis space [1]. The method is capable of predicting nuclear structure from inter-nucleon forces derived from quantum chromodynamics by means of chiral effective field theory [2]. NCSM extensions to the microscopic description of nuclear reactions are now under development. In my talk, I will first discuss our recent calculations of the ^4He total photo-absorption cross section using two- and three-nucleon interactions from chiral effective field theory [3]. I will then outline our effort to augment the NCSM by the resonating group method (RGM) technique to develop a new method capable of describing simultaneously both bound states and nuclear reactions on light nuclei [4]. This approach, which preserves translational symmetry and the Pauli principle, will allow us to calculate cross sections of reactions important for astrophysics and describe weakly-bound systems from first principles. I will present our first phase shift results for neutron scattering off ^3H, ^4He and ^7Li and proton scattering off ^3He, ^4He and ^7Be using realistic nucleon-nucleon potentials. 3mm [1] P. Navr'atil, J. P. Vary and B. R. Barrett, Phys. Rev. C 62, 054311 (2000). [2] P. Navr'atil and V. G. Gueorguiev and J. P. Vary, W. E. Ormand and A. Nogga, Phys. Rev. Lett. 99, 042501 (2007). [3] S. Quaglioni and P. Navr'atil, Phys. Lett. B 652, 370 (2007). [4] S. Quaglioni and P. Navr'atil, arXiv:0712.0855.

  9. Atmospheric characterization of the hot Jupiter Kepler-13Ab

    Energy Technology Data Exchange (ETDEWEB)

    Shporer, Avi; O' Rourke, Joseph G.; Knutson, Heather A. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Szabó, Gyula M. [ELTE Gothard Astrophysical Observatory, H-9704 Szombathely, Szent Imre herceg út 112 (Hungary); Zhao, Ming [Department of Astronomy and Astrophysics, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802 (United States); Burrows, Adam [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Fortney, Jonathan [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Agol, Eric [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Cowan, Nicolas B. [Center for Interdisciplinary Exploration and Research in Astrophysics and Department of Physics and Astronomy, Northwestern University, 2131 Tech Drive, Evanston, IL 60208 (United States); Desert, Jean-Michel [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Howard, Andrew W. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Isaacson, Howard [University of California, Berkeley, CA 94720 (United States); Lewis, Nikole K.; Showman, Adam P. [Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States); Todorov, Kamen O. [Institute for Astronomy, ETH Zürich, Wolfgang-Pauli-Strasse 27, 8093 Zürich (Switzerland)

    2014-06-10

    Kepler-13Ab (= KOI-13.01) is a unique transiting hot Jupiter. It is one of very few known short-period planets orbiting a hot A-type star, making it one of the hottest planets currently known. The availability of Kepler data allows us to measure the planet's occultation (secondary eclipse) and phase curve in the optical, which we combine with occultations observed by warm Spitzer at 4.5 μm and 3.6 μm and a ground-based occultation observation in the K{sub s} band (2.1 μm). We derive a day-side hemisphere temperature of 2750 ± 160 K as the effective temperature of a black body showing the same occultation depths. Comparing the occultation depths with one-dimensional planetary atmosphere models suggests the presence of an atmospheric temperature inversion. Our analysis shows evidence for a relatively high geometric albedo, A {sub g} = 0.33{sub −0.06}{sup +0.04}. While measured with a simplistic method, a high A {sub g} is supported also by the fact that the one-dimensional atmosphere models underestimate the occultation depth in the optical. We use stellar spectra to determine the dilution, in the four wide bands where occultation was measured, due to the visual stellar binary companion 1.''15 ± 0.''05 away. The revised stellar parameters measured using these spectra are combined with other measurements, leading to revised planetary mass and radius estimates of M{sub p} = 4.94-8.09 M {sub J} and R{sub p} = 1.406 ± 0.038 R {sub J}. Finally, we measure a Kepler midoccultation time that is 34.0 ± 6.9 s earlier than expected based on the midtransit time and the delay due to light-travel time and discuss possible scenarios.

  10. 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.

  11. 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

  12. 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

  13. ABS/PVC合金的热稳定性分析%Analysis on the Heat Stability of ABS&PVC Blends

    Institute of Scientific and Technical Information of China (English)

    马玫; 故行俊; 雷祖碧; 唐金桂

    2005-01-01

    通过热烘变色试验,对ABS/PVC合金的热稳定性进行分析.结果表明,所试验的三种PVC专用热稳定剂会加速ABS树指的热老化;当ABS/PVC合金比例为60/40时,其热稳定性较佳;CPE对合金的热烘变色有利;有机锡热稳定剂的效果最好.

  14. Resistance to Bacillus thuringiensis Toxin Cry2Ab in Trichoplusia ni Is Conferred by a Novel Genetic Mechanism

    OpenAIRE

    Song, Xiaozhao; Kain, Wendy; Cassidy, Douglas; Wang, Ping

    2015-01-01

    The resistance to the Bacillus thuringiensis (Bt) toxin Cry2Ab in a greenhouse-originated Trichoplusia ni strain resistant to both Bt toxins Cry1Ac and Cry2Ab was characterized. Biological assays determined that the Cry2Ab resistance in the T. ni strain was a monogenic recessive trait independent of Cry1Ac resistance, and there existed no significant cross-resistance between Cry1Ac and Cry2Ab in T. ni. From the dual-toxin-resistant T. ni strain, a strain resistant to Cry2Ab only was isolated,...

  15. Eletrocardiografia computadorizada em cães: estudo comparativo

    Directory of Open Access Journals (Sweden)

    Lídia S. Oliveira

    2013-07-01

    Full Text Available O método de eletrocardiografia computadorizada (ECG-C vem sendo crescentemente difundido na medicina veterinária, havendo atualmente diversas marcas e modelos de eletrocardiógrafos disponíveis no mercado. Diante da possibilidade de diferenças na sensibilidade e na reprodutibilidade das medidas obtidas nos traçados, o presente estudo teve como objetivo comparar os parâmetros eletrocardiográficos de cães, obtidos por dois sistemas. Foram avaliados dois diferentes softwares computadorizados, o Wincardio Micromed® (WIN e o modelo TEB ECGPC® (TEB. Quarenta e dois cães hígidos, de diferentes raças (Cocker Spaniel, Daschund, Labrador, Pinscher, Pit Bull Terrier Poodle, Schnauzer, Shit Tzu, Yorkshire e sem raça definida, machos e fêmeas e com idade entre 4 meses e 16 anos foram agrupados segundo o peso e examinados pelos dois sistemas. As medidas eletrocardiográficas dos diferentes traçados foram analisadas na derivação DII. Os resultados indicaram que o sistema TEB apresentou maior sensibilidade na obtenção das medidas de duração da onda P e do complexo QRS, enquanto o sistema WIN foi mais sensível para determinar as medidas de amplitude dos mesmos parâmetros. Os animais de maior porte (26-37kg apresentaram maior variância nas medidas de duração e amplitude de onda P e duração do complexo QRS em comparação aos cães de médio (14-25kg e pequeno (1-13kg porte. O achado de diferenças entre os sistemas testados deve ser levado em consideração ao se empregar os diversos equipamentos para diagnóstico por meio de ECG-C na rotina clínica, de modo a evitarem-se divergências na interpretação dos exames entre diferentes prestadores de serviços veterinários.

  16. The end of a myth—Bt (Cry1Ab) maize does not harm green lacewings

    Science.gov (United States)

    Romeis, Jörg; Meissle, Michael; Naranjo, Steven E.; Li, Yunhe; Bigler, Franz

    2014-01-01

    A concern with Bt-transgenic insect-resistant plants is their potential to harm non-target organisms. Early studies reported that Cry1Ab-producing Bt maize and purified Cry1Ab harmed larvae of the green lacewing, Chrysoperla carnea. Although these effects could not be confirmed in subsequent studies, some authors still refer to them as evidence that Bt maize harms beneficial species. We provide a comprehensive review of the studies evaluating the effects of Bt (Cry1Ab) maize on C. carnea. The evidence indicates that this important predator is not affected by Bt maize or by the produced Cry1Ab protein. We discuss how conceptual models can assist environmental risk assessments, and we emphasize the importance of robust and reproducible studies. PMID:25161661

  17. The end of a myth-Bt (Cry1Ab) maize does not harm green lacewings.

    Science.gov (United States)

    Romeis, Jörg; Meissle, Michael; Naranjo, Steven E; Li, Yunhe; Bigler, Franz

    2014-01-01

    A concern with Bt-transgenic insect-resistant plants is their potential to harm non-target organisms. Early studies reported that Cry1Ab-producing Bt maize and purified Cry1Ab harmed larvae of the green lacewing, Chrysoperla carnea. Although these effects could not be confirmed in subsequent studies, some authors still refer to them as evidence that Bt maize harms beneficial species. We provide a comprehensive review of the studies evaluating the effects of Bt (Cry1Ab) maize on C. carnea. The evidence indicates that this important predator is not affected by Bt maize or by the produced Cry1Ab protein. We discuss how conceptual models can assist environmental risk assessments, and we emphasize the importance of robust and reproducible studies.

  18. 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...

  19. Effects of alloying side B on Ti-based AB2 hydrogen storage alloys

    Institute of Scientific and Technical Information of China (English)

    王家淳; 于荣海; 刘庆

    2004-01-01

    Ti-based AB2-type hydrogen storage alloys are a group of promising materials, which will probably replace the prevalent rare earth-based AB5-type alloys and be adopted as the main cathode materials of nickelmetal hydride (Ni-MH) batteries in the near future. Alloying in side B is a major way to improve the performance of Ti-based AB2-type alloys. Based on recent studies, the effects of alloying elements in side B upon the performance of Ti-based AB2 -type hydrogen storage alloys are systematically reviewed here. These performances are divided into two categories, namely PCI characteristics, including hydrogen storage capacity (HSC), plateau pressure (PP), pressure hysteresis (PH) and pressure plateau sloping (PPS) , and electrochemical properties, including discharge capacity (DC), activation property (AP), cycling stability (CS) and high-rate dischargeability (HRD). Furthermore, the existing problems in these investigations and some suggestions for future research are proposed.

  20. Hydrogen adsorption on boron doped graphene: an {\\it ab initio} study

    OpenAIRE

    Miwa, R. H.; Martins, T B; Fazzio, A.

    2007-01-01

    The electronic and structural properties of (i) boron doped graphene sheets, and (ii) the chemisorption processes of hydrogen adatoms on the boron doped graphene sheets have been examined by {\\it ab initio} total energy calculations.

  1. 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...... in a wide temperature range.. The conductivity of the acid doped ab-PBI membranes was studied in a temperature range of 80oC to 200oC under different relative humidity and with different acid doping levels. PEMFC test results indicated that the fuel cell could be operated at temperatures up to 200o......C with phosphoric acid doped ab-PBI as the electrolyte under atmospheric pressure at 200°C without humidification....

  2. 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....

  3. Data of evolutionary structure change: 1D3AB-1LLDA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1D3AB-1LLDA 1D3A 1LLD B A -TKVSVVGAAGTVGAAAGYNIALRDIADEVVFVDIPDKE...PNAIYMLITNPVDIATHVAQKLTGLPENQIFGSGTNLDSARLRFLIAQQTGVNVKNVHAYIAGEHGDSEVPLWESATIGGVPMSDWTPLPGHDPLDADKREEIHQEVK... 1LLD A 1LLDA...> 1 1LLD A 1LLDA

  4. 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

  5. AdnAB: a new DSB-resecting motor-nuclease from mycobacteria.

    Science.gov (United States)

    Sinha, Krishna Murari; Unciuleac, Mihaela-Carmen; Glickman, Michael S; Shuman, Stewart

    2009-06-15

    The resection of DNA double-strand breaks (DSBs) in bacteria is a motor-driven process performed by a multisubunit helicase-nuclease complex: either an Escherichia coli-type RecBCD enzyme or a Bacillus-type AddAB enzyme. Here we identify mycobacterial AdnAB as the founder of a new family of heterodimeric helicase-nucleases with distinctive properties. The AdnA and AdnB subunits are each composed of an N-terminal UvrD-like motor domain and a C-terminal nuclease module. The AdnAB ATPase is triggered by dsDNA with free ends and the energy of ATP hydrolysis is coupled to DSB end resection by the AdnAB nuclease. The mycobacterial nonhomologous end-joining (NHEJ) protein Ku protects DSBs from resection by AdnAB. We find that AdnAB incises ssDNA by measuring the distance from the free 5' end to dictate the sites of cleavage, which are predominantly 5 or 6 nucleotides (nt) from the 5' end. The "molecular ruler" of AdnAB is regulated by ATP, which elicits an increase in ssDNA cleavage rate and a distal displacement of the cleavage sites 16-17 nt from the 5' terminus. AdnAB is a dual nuclease with a clear division of labor between the subunits. Mutations in the nuclease active site of the AdnB subunit ablate the ATP-inducible cleavages; the corresponding changes in AdnA abolish ATP-independent cleavage. Complete suppression of DSB end resection requires simultaneous mutation of both subunit nucleases. The nuclease-null AdnAB is a helicase that unwinds linear plasmid DNA without degrading the displaced single strands. Mutations of the phosphohydrolase active site of the AdnB subunit ablate DNA-dependent ATPase activity, DSB end resection, and ATP-inducible ssDNA cleavage; the equivalent mutations of the AdnA subunit have comparatively little effect. AdnAB is a novel signature of the Actinomycetales taxon. Mycobacteria are exceptional in that they encode both AdnAB and RecBCD, suggesting the existence of alternative end-resecting motor-nuclease complexes. PMID:19470566

  6. Improving the control of work-in-process at VSM Group AB

    OpenAIRE

    Karlsson, Per-Johan; Porto, Mariana

    2008-01-01

    Today many companies face problems with inventory management. The importance of adequate inventory management has become more evident, while organizations try to reduce their costs and increase their service level. This master thesis was conducted at VSM Group AB in Huskvarna, which is a manufacturer that produces and delivers sewing machines to a worldwide market. VSM Group AB has problems with the management and the refilling of the work-in-process (WIP) inventories and also with lack of in...

  7. An ab initio Non-Equilibrium Green Function Approach to Charge Transport: Dithiolethine

    Institute of Scientific and Technical Information of China (English)

    Alexander Schnurpfeil; SONG Bo; Martin Albrecht

    2006-01-01

    @@ We present a novel ab initio non-equilibrium approach to calculate the current across a molecular junction. The method rests on a wavefunction-based full ab initio description of the central region of the junction combined with a tight binding approximation for the electrodes in the frame of the Keldysh Green function formalism. Our procedure is demonstrated for a dithiolethine molecule located between silver electrodes. The main conducting channel is identified and the full current-voltage characteristic is calculated.

  8. Effects of POSS nanoparticles on ABS-g-Ma thermo oxidation resistance

    OpenAIRE

    Vilà Ramirez, N.; Sánchez Soto, Miguel

    2012-01-01

    Thermo oxidative degradation at and beyond process- ing temperatures has been carried out on ABS copoly- mer grafted with Maleic Anhydride (ABS- g -Ma) and three nanocomposites with the above material melt-blended with different types of POSS, being amino-propyl isobutyl (APOSS), glycidyl (GPOSS), and trisilanol (TPOSS). The incorporation adequacy of the nanofillers into the matrix has been assessed with scanning electron microscopy (SEM) and differential scan...

  9. MANAGING CUSTOMER LIFE-CYCLE : Case company: OY GOLDEN CROP AB

    OpenAIRE

    He, Yao

    2016-01-01

    Oy Golden Crop Ab has been founded in 2012 February and is food trading company in Finland which supplies the Asian restaurants all over the Finland. For example, Chinese restaurants, Sushi restaurants, Thai restaurants, Indian restaurants and Vietnamese restaurants. Due to the high competition in the Helsinki region, the company needs to improve its system from customer perspective The aim of this thesis is to generate models to manage customer life-cycle for Oy Golden Crop Ab. Therefor...

  10. Enantioselective synthesis of the predominant AB ring system of the Schisandra nortriterpenoid natural products.

    Science.gov (United States)

    Gockel, Birgit; Goh, Shermin S; Puttock, Emma J; Baars, Hannah; Chaubet, Guilhem; Anderson, Edward A

    2014-09-01

    An enantioselective synthesis of the AB ring system common to the majority of the Schisandra nortriterpenoid natural products is reported. Key steps include a stereospecific ring opening of a trisubstituted epoxide and the use of a β-lactone to enable installation of the gem-dimethyl functionality of the B ring. An acetalization strategy played a key role in a late-stage biomimetic AB ring bicyclization.

  11. AbCD: arbitrary coverage design for sequencing-based genetic studies

    OpenAIRE

    Kang, Jian; Huang, Kuan-Chieh; Xu, Zheng; Wang, Yunfei; Abecasis, Gonçalo R.; Li, Yun

    2013-01-01

    Summary: Recent advances in sequencing technologies have revolutionized genetic studies. Although high-coverage sequencing can uncover most variants present in the sequenced sample, low-coverage sequencing is appealing for its cost effectiveness. Here, we present AbCD (arbitrary coverage design) to aid the design of sequencing-based studies. AbCD is a user-friendly interface providing pre-estimated effective sample sizes, specific to each minor allele frequency category, for designs with arbi...

  12. Immunoglobulin fragments, F(ab')2, that are cytotoxic to enzyme-treated cells.

    Science.gov (United States)

    Holtgrewe, E M; Killion, J J

    1984-07-01

    Bivalent immunoglobulin fragments of IgG, F(ab')2, prepared from normal murine sera were found to be cytotoxic to neuraminidase-treated cells. The fragments were cytotoxic to both allogenic and syngeneic targets (with respect to the source of the sera), suggesting that the antigen bound by the F(ab')2 is not related to the major histocompatibility locus of mice (H-2).

  13. Plasmid-Mediated OqxAB Is an Important Mechanism for Nitrofurantoin Resistance in Escherichia coli.

    Science.gov (United States)

    Ho, Pak-Leung; Ng, Ka-Ying; Lo, Wai-U; Law, Pierra Y; Lai, Eileen Ling-Yi; Wang, Ya; Chow, Kin-Hung

    2015-11-09

    Increasing consumption of nitrofurantoin (NIT) for treatment of acute uncomplicated urinary tract infections (UTI) highlights the need to monitor emerging NIT resistance mechanisms. This study investigated the molecular epidemiology of the multidrug-resistant efflux gene oqxAB and its contribution to nitrofurantoin resistance by using Escherichia coli isolates originating from patients with UTI (n = 205; collected in 2004 to 2013) and food-producing animals (n = 136; collected in 2012 to 2013) in Hong Kong. The oqxAB gene was highly prevalent among NIT-intermediate (11.5% to 45.5%) and -resistant (39.2% to 65.5%) isolates but rare (0% to 1.7%) among NIT-susceptible (NIT-S) isolates. In our isolates, the oqxAB gene was associated with IS26 and was carried by plasmids of diverse replicon types. Multilocus sequence typing revealed that the clones of oqxAB-positive E. coli were diverse. The combination of oqxAB and nfsA mutations was found to be sufficient for high-level NIT resistance. Curing of oqxAB-carrying plasmids from 20 NIT-intermediate/resistant UTI isolates markedly reduced the geometric mean MIC of NIT from 168.9 μg/ml to 34.3 μg/ml. In the plasmid-cured variants, 20% (1/5) of isolates with nfsA mutations were NIT-S, while 80% (12/15) of isolates without nfsA mutations were NIT-S (P = 0.015). The presence of plasmid-based oqxAB increased the mutation prevention concentration of NIT from 128 μg/ml to 256 μg/ml and facilitated the development of clinically important levels of nitrofurantoin resistance. In conclusion, plasmid-mediated oqxAB is an important nitrofurantoin resistance mechanism. There is a great need to monitor the dissemination of this transferable multidrug-resistant efflux pump.

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

    OpenAIRE

    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...

  15. Composition of the Putative Prepore Complex of Bacillus thuringiensis Cry1Ab Toxin

    OpenAIRE

    Nair, Manoj S; Dean, Donald H.

    2015-01-01

    Prepore formation is hypothesized to be an obligate step in the insertion of Cry1Ab toxin into insect brush border membrane vesicles. We examined the architecture of the putative prepore when isolated using the published protocols [1] [2]. Our results demonstrate that the putative prepore form of Cry1Ab is a combination of receptor proteins attached to the toxin, when purified. The results also suggest that this prepore form as prepared by the methods published is different from other membran...

  16. Hidroponik Tanaman Sayuran Sawi Beda Varietas Dengan Formulasi Nurtisi Ab Mix Dan Formulasi Racikan

    OpenAIRE

    Siagian, Vyvian W.

    2016-01-01

    Vyvian W Siagian, research “Hydroponics of Mustard Vegetable Crops Different Varieties with AB Mix Nutrient and Self-made Nutrient Formulation”, supervised by Ir. Bintang, MP and Ir. Fauzi, MP. This research is aimed to find a differences production from hydroponics of mustard vegetable crops which is have a different varity within AB Mix nutrient and self-made nutrient formulation. It was located at Kompleks Citra Arkadia Jl. Bunga Wijaya Padang Bulan, Medan on June 2015 until September 2015...

  17. 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...

  18. Offering Students a Selection of Multiple Class B/AB Power Amplifiers as a Remote Laboratory

    Directory of Open Access Journals (Sweden)

    Dag Andreas Hals Samuelsen

    2011-09-01

    Full Text Available In this paper a remote laboratory setup for conducting experiments on a class B/AB power amplifier is presented, addressing the problems related to running experiments requiring temperature matching between transistors and bias diodes, in order to avoid thermal runaway in the transistors. In addition there is an option for the student to quickly examine a range of different transistors in both class B and class AB setups.

  19. A Novel Variant in CMAH Is Associated with Blood Type AB in Ragdoll Cats

    Science.gov (United States)

    Gandolfi, Barbara; Grahn, Robert A.; Gustafson, Nicholas A.; Proverbio, Daniela; Spada, Eva; Adhikari, Badri; Cheng, Janling; Andrews, Gordon; Lyons, Leslie A.; Helps, Chris R.

    2016-01-01

    The enzyme cytidine monophospho-N-acetylneuraminic acid hydroxylase is associated with the production of sialic acids on cat red blood cells. The cat has one major blood group with three serotypes; the most common blood type A being dominant to type B. A third rare blood type is known as AB and has an unclear mode of inheritance. Cat blood type antigens are defined, with N-glycolylneuraminic acid being associated with type A and N-acetylneuraminic acid with type B. Blood type AB is serologically characterized by agglutination using typing reagents directed against both A and B epitopes. While a genetic characterization of blood type B has been achieved, the rare type AB serotype remains genetically uncharacterized. A genome-wide association study in Ragdoll cats (22 cases and 15 controls) detected a significant association between blood type AB and SNPs on cat chromosome B2, with the most highly associated SNP being at position 4,487,432 near the candidate gene cytidine monophospho-N-acetylneuraminic acid hydroxylase. A novel variant, c.364C>T, was identified that is highly associated with blood type AB in Ragdoll cats and, to a lesser degree, with type AB in random bred cats. The newly identified variant is probably linked with blood type AB in Ragdoll cats, and is associated with the expression of both antigens (N-glycolylneuraminic acid and N-acetylneuraminic acid) on the red blood cell membrane. Other variants, not identified by this work, are likely to be associated with blood type AB in other breeds of cat. PMID:27171395

  20. Estudos sôbre índice de siclemia

    Directory of Open Access Journals (Sweden)

    Ernani Martins da Silva

    1945-04-01

    Full Text Available O índice de sinclêmicos encontrado foi de 10%, examinando-se uma amostra heterógenea de 1130 indivíduos de grupo étnico negróide e mestiços desta etnia. Foi negativa a pesquisa em 120 indivíduos caucasóides e 30 mongolóides. O "índice familiar de siclêmicos" - a percentagem desses indivíduos em um grupo de famílias - fornece um resultado mais proximo do verdadeiro número de siclêmicos em uma amostra de população. O método clássico fornece um número inferior ao existente na amostra estudada. A aplicação do teste de siclemia em Jurisprudência, Antropologia e Etnografia, poderá contribuir, na qualidade de método auxiliar, no estudo de vários problemas. São indicados como métodos de escolha: o de Emmel e o de maceração de tecidos conservados em solução de formol ou alcool. Êste último permite estudos retrospectivos. A estase circulatória parece não ser fator suficiente para a passagem da condição de siclêmico para anemico. O parasitismo da hemátia pelo Plasmodium vivax não impede o fenômeno da siclisação. Infecção por plasmodídeos (P. falciparum e P. vivax não é fator suficiente para desencadear a doença. A importância da descoberta de Emmel (descoberta do fenômeno da siclisação reside no conhecimento em doença heredofamiliar de fato novo de máxima significação: a possibilidade de identificar os indivíduos ainda na fase de latência, ou seja, no período que medeia entre o nascimento e a instalação dos primeiros sintomas da doença. A relação entre casos de anemia falciforme ocorridos em gerações por vêzes muito afastadas (fenômeno denominado "skipping" - salto - pelos autores de lingua inglêsa é mantida através dos siclêmicos. Êsses indivíduos podem ser comparados aos portadores de germe no sentido empregado na profilaxia das doenças infectuosas. Exames periódicos dos siclêmicos poderiam contribuir para esclarecimento da patogenia e forneceriam dados úteis para a

  1. 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)

  2. Hepatoma-Targeted Radionuclide Immune Albumin Nanospheres: (131)I-antiAFPMcAb-GCV-BSA-NPs.

    Science.gov (United States)

    Lin, Mei; Huang, Junxing; Zhang, Dongsheng; Jiang, Xingmao; Zhang, Jia; Yu, Hong; Xiao, Yanhong; Shi, Yujuan; Guo, Ting

    2016-01-01

    An effective strategy has been developed for synthesis of radionuclide immune albumin nanospheres ((131)I-antiAFPMcAb-GCV-BSA-NPs). In vitro as well as in vivo targeting of (131)I-antiAFPMcAb-GCV-BSA-NPs to AFP-positive hepatoma was examined. In cultured HepG2 cells, the uptake and retention rates of (131)I-antiAFPMcAb-GCV-BSA-NPs were remarkably higher than those of (131)I alone. As well, the uptake rate and retention ratios of (131)I-antiAFPMcAb-GCV-BSA-NPs in AFP-positive HepG2 cells were also significantly higher than those in AFP-negative HEK293 cells. Compared to (131)I alone, (131)I-antiAFPMcAb-GCV-BSA-NPs were much more easily taken in and retained by hepatoma tissue, with a much higher T/NT. Due to good drug-loading, high encapsulation ratio, and highly selective affinity for AFP-positive tumors, the (131)I-antiAFPMcAb-GCV-BSA-NPs are promising for further effective radiation-gene therapy of hepatoma.

  3. Treatment with Anti-EGF Ab Ameliorates Experimental Autoimmune Encephalomyelitis via Induction of Neurogenesis and Oligodendrogenesis

    Directory of Open Access Journals (Sweden)

    Yifat Amir-Levy

    2014-01-01

    Full Text Available Background. The neural stem cells (NSCs migrate to the damaged sites in multiple sclerosis (MS and in experimental autoimmune encephalomyelitis (EAE. However, the differentiation into neurons or oligodendrocytes is blocked. Epidermal growth factor (EGF stimulates NSC proliferation and mobilization to demyelinated lesions but also induces astrogenesis and glial scar. Objective. To examine the clinical and histopathological effects of EGF neutralization on EAE. Methods. EAE-induced SJL mice were intravenously treated with either anti-EGF neutralizing antibody (Ab or isotype control or PBS. On day 9 after immunization, 3 mice of each group were daily treated for 9 days with BrdU and then sacrificed for immunohistochemical analysis. Results. Treatment with anti-EGF Ab significantly ameliorated EAE symptoms during the second relapse. Anti-EGF Ab induced a shift from BrdU+GFAP+ NSCs to BrdU+DCX+ neuroblasts in the subventricular zone (SVZ, increased BrdU+NeuN+ neurons in the granular cell layer of the dentate gyrus, and increased BrdU+O4+ oligodendrocytes in the SVZ. There was no change in the inflammatory infiltrates in response to anti-EGF Ab. Conclusions. Therapy with anti-EGF Ab ameliorates EAE via induction of neurogenesis and oligodendrogenesis. No immunosuppressive effect was found. Further investigation is needed to support these notions of beneficial effect of anti-EGF Ab in MS.

  4. 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.

  5. Transcriptional silencing and developmental reactivation of cry1Ab gene in transgenic rice

    Institute of Scientific and Technical Information of China (English)

    WU; Gang(吴刚); CUI; Hairui(崔海瑞); SHU; Qingyao(舒庆尧); YE; Gongyin(叶恭银); XIA; Yingwu(夏英武); GAO; Mingwei(高明蔚); Illimar; Altosaar; LI; Yi(李毅)

    2002-01-01

    One transgenic rice line lacking Cry1Ab expression product was screened in the progenies of Agrobacterium-transformed transgenic rice variety Zhong 8215 with a cry1Ab gene under field releasing conditions by using GUS histochemical assay and Western blot. Molecular hybridization results revealed that the cry1Ab gene was silenced in the transgenic rice variety Zhong 8215 and two copies of ubiquitin promoter were integrated into the rice genome. The silencing of cry1Ab gene in transgenic rice was found to be due to the methylation of the ubiquitin promoter as revealed by methylation analysis. Meanwhile, different concentrations of demethylation reagent 5-azacytidine combining with different treatment time were employed to treat the silenced transgenic rice seeds. The results indicated that 5-azacytidine could reactivate 8%-30% of the silenced transgenic rice plants and the expression level of the reactivated cry1Ab transgene could reach as high as 0.147% of the total soluble protein. Treatment with low concentration of 5-azacytidine(45 mg/L for 1 d and 2 d) could lead to the highest reactivation ratio and the highest expression level of the cry1Ab gene.

  6. Cry1Ab protein from Bt transgenic rice does not residue in rhizosphere soil

    International Nuclear Information System (INIS)

    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

  7. Yeast killer toxin-like candidacidal Ab6 antibodies elicited through the manipulation of the idiotypic cascade.

    Science.gov (United States)

    Polonelli, Luciano; Beninati, Concetta; Teti, Giuseppe; Felici, Franco; Ciociola, Tecla; Giovati, Laura; Sperindè, Martina; Lo Passo, Carla; Pernice, Ida; Domina, Maria; Arigò, Milena; Papasergi, Salvatore; Mancuso, Giuseppe; Conti, Stefania; Magliani, Walter

    2014-01-01

    A mouse anti-anti-anti-idiotypic (Id) IgM monoclonal antibody (mAb K20, Ab4), functionally mimicking a Wyckerhamomyces anomalus (Pichia anomala) killer toxin (KT) characterized by fungicidal activity against yeasts presenting specific cell wall receptors (KTR) mainly constituted by β-1,3-glucan, was produced from animals presenting anti-KT Abs (Ab3) following immunization with a rat IgM anti-Id KT-like mAb (mAb K10, Ab2). MAb K10 was produced by immunization with a KT-neutralizing mAb (mAb KT4, Ab1) bearing the internal image of KTR. MAb K20, likewise mAb K10, proved to be fungicidal in vitro against KT-sensitive Candida albicans cells, an activity neutralized by mAb KT4, and was capable of binding to β-1,3-glucan. MAb K20 and mAb K10 competed with each other and with KT for binding to C. albicans KTR. MAb K20 was used to identify peptide mimics of KTR by the selection of phage clones from random peptide phage display libraries. Using this strategy, four peptides (TK 1-4) were selected and used as immunogen in mice in the form of either keyhole limpet hemocyanin (KLH) conjugates or peptide-encoding minigenes. Peptide and DNA immunization could induce serum Abs characterized by candidacidal activity, which was inhibited by laminarin, a soluble β-1,3-glucan, but not by pustulan, a β-1,6-glucan. These findings show that the idiotypic cascade can not only overcome the barrier of animal species but also the nature of immunogens and the type of technology adopted. PMID:25162681

  8. Yeast killer toxin-like candidacidal Ab6 antibodies elicited through the manipulation of the idiotypic cascade.

    Directory of Open Access Journals (Sweden)

    Luciano Polonelli

    Full Text Available A mouse anti-anti-anti-idiotypic (Id IgM monoclonal antibody (mAb K20, Ab4, functionally mimicking a Wyckerhamomyces anomalus (Pichia anomala killer toxin (KT characterized by fungicidal activity against yeasts presenting specific cell wall receptors (KTR mainly constituted by β-1,3-glucan, was produced from animals presenting anti-KT Abs (Ab3 following immunization with a rat IgM anti-Id KT-like mAb (mAb K10, Ab2. MAb K10 was produced by immunization with a KT-neutralizing mAb (mAb KT4, Ab1 bearing the internal image of KTR. MAb K20, likewise mAb K10, proved to be fungicidal in vitro against KT-sensitive Candida albicans cells, an activity neutralized by mAb KT4, and was capable of binding to β-1,3-glucan. MAb K20 and mAb K10 competed with each other and with KT for binding to C. albicans KTR. MAb K20 was used to identify peptide mimics of KTR by the selection of phage clones from random peptide phage display libraries. Using this strategy, four peptides (TK 1-4 were selected and used as immunogen in mice in the form of either keyhole limpet hemocyanin (KLH conjugates or peptide-encoding minigenes. Peptide and DNA immunization could induce serum Abs characterized by candidacidal activity, which was inhibited by laminarin, a soluble β-1,3-glucan, but not by pustulan, a β-1,6-glucan. These findings show that the idiotypic cascade can not only overcome the barrier of animal species but also the nature of immunogens and the type of technology adopted.

  9. Estudo de caso: neuropatia auditiva Auditory neuropathy: a study case

    Directory of Open Access Journals (Sweden)

    Viviane M. Parra

    2003-03-01

    Full Text Available Atualmente, podemos complementar os resultados encontrados na audiometria convencional com os obtidos nos exames eletrofisiológicos, o que nos permite diagnosticar não apenas uma perda auditiva periférica, mas também diferenciar uma perda auditiva coclear da neural, ou central. Isto nos conduziu a um grupo novo de pacientes que apresentava alteração na sincronia neural com função normal das células ciliadas externas. Esta patologia é conhecida como Neuropatia Auditiva. O objetivo deste estudo é descrever as características audiológicas de um paciente com Neuropatia Auditiva atendido no Centro de Docência e Pesquisa em Fonoaudiologia da Faculdade de Medicina da Universidade de São Paulo (FMUSP, correlacionando os achados com os encontrados na literatura. O caso descrito é de um indivíduo de 24 anos de idade, com o diagnóstico de Neuropatia Auditiva, atendido no ano de 2001 no Centro de Docência e Pesquisa em Fonoaudiologia da FMUSP. Foram realizados anamnese, audiometria tonal e vocal, medidas de imitância acústica, Emissões Otoacústicas (EOAs e Audiometria de Tronco Encefálico (ABR. Observamos no caso estudado a incompatibilidade de resultados entre audiometria tonal e testes de inteligibilidade de fala, com os exames objetivos, EOAs e ABR, onde observou-se perda auditiva com importante alteração nos testes de inteligibilidade de fala, EOAs presentes e ABR anormal. Estes dados sugerem função coclear normal e alteração da sincronia neural.Nowadays, in our clinic, we can complement the conventional audiometry results with electrophysiologic exams. Not only does allow us to diagnose a peripheral hearing loss but also to differentiate cochlear, neural or central hearing loss. It led us to a new group of patients that presented changes in neural synchrony, with normal functions of the outer ear hair cells. This pathology is known as Auditory Neuropathy. Our study purpose is describe the audiologist characteristic of a

  10. Impacto da plataforma Moodle nas escolas de Famalicão: um estudo de caso

    OpenAIRE

    Pimentel, Paulo Carlos Fernandes

    2009-01-01

    Dissertação de mestrado em Educação (área de especialização em Tecnologia Educativa) Com a proliferação, por todas as escolas do país, da utilização da plataforma Moodle, urge estudar a forma como está a ser utilizada no apoio ao ensino presencial. No âmbito da presente dissertação de mestrado, desenvolveu-se um estudo com o objectivo de analisar o impacto da plataforma Moodle no Agrupamento de Escolas Júlio Brandão, em Vila Nova de Famalicão. O estudo realizado foi um estudo de caso...

  11. Uso do conceito de aprendizagem em estudos relacionados ao trabalho e organizações

    Directory of Open Access Journals (Sweden)

    Francisco Antonio Coelho Junior

    2008-01-01

    Full Text Available A literatura em comportamento organizacional apresenta diversos estudos referenciando o conceito aprendizagem aplicado no âmbito das organizações. Porém, verifica-se o uso pouco crítico ou sistemático deste conceito. O objetivo do presente artigo consiste em realizar uma análise conceitual do termo aprendizagem, justificando sua transposição para estudos organizacionais. Aplicaram-se técnicas de análise conceitual propostas por Ryle. Como resultado, verificou-se que a natureza multifacetada do conceito de aprendizagem favorece o advento das diversas definições associadas a ele. Espera-se que haja maior sistematicidade acerca do uso do termo aprendizagem aplicado em estudos organizacionais, considerando seus níveis de análise e as dimensões presentemente discutidas.

  12. Caso de estudo: a entrada do azeite Gallo no mercado chinês

    OpenAIRE

    Costa, Miguel Maria Portugal Martins

    2014-01-01

    Mestrado em Gestão 7 Classificação JEL: M16; F23 A elaboração desta dissertação consiste na criação de um caso de estudo pedagógico com o objectivo de tirar ilações sobre a entrada da marca “Azeite Gallo” no mercado Chinês. Optamos por desenvolver este caso de estudo através de um estudo qualitativo, suportado por um referencial teórico. O intuito do projecto é de documentar um exemplo paradigmático de um produto consumível de marca portuguesa que sucedeu em ultrapassar as barreiras ...

  13. Characterization of the mechanism of action of the genetically modified Cry1AbMod toxin that is active against Cry1Ab-resistant insects.

    Science.gov (United States)

    Muñóz-Garay, Carlos; Portugal, Leivi; Pardo-López, Liliana; Jiménez-Juárez, Nuria; Arenas, Ivan; Gómez, Isabel; Sánchez-López, Rosana; Arroyo, Raquel; Holzenburg, Andreas; Savva, Christos G; Soberón, Mario; Bravo, Alejandra

    2009-10-01

    Bacillus thuringiensis Cry toxins are used in the control of insect pests. They are pore-forming toxins with a complex mechanism that involves the sequential interaction with receptors. They are produced as protoxins, which are activated by midgut proteases. Activated toxin binds to cadherin receptor, inducing an extra cleavage including helix alpha-1, facilitating the formation of a pre-pore oligomer. The toxin oligomer binds to secondary receptors such as aminopeptidase and inserts into lipid rafts forming pores and causing larval death. The primary threat to efficacy of Bt-toxins is the evolution of insect resistance. Engineered Cry1AMod toxins, devoid of helix alpha-1, could be used for the control of resistance in lepidopterans by bypassing the altered cadherin receptor, killing resistant insects affected in this receptor. Here we analyzed the mechanism of action of Cry1AbMod. We found that alkaline pH and the presence of membrane lipids facilitates the oligomerization of Cry1AbMod. In addition, tryptophan fluorescence emission spectra, ELISA binding to pure aminopeptidase receptor, calcein release assay and analysis of ionic-conductance in planar lipid bilayers, indicated that the secondary steps in mode of action that take place after interaction with cadherin receptor such as oligomerization, receptor binding and pore formation are similar in the Cry1AbMod and in the wild type Cry1Ab. Finally, the membrane-associated structure of Cry1AbMod oligomer was analyzed by electron crystallography showing that it forms a complex with a trimeric organization. PMID:19559004

  14. Factores de competitividade do sector cerâmico : um estudo de caso

    OpenAIRE

    Coelho, Liliana Carla Tavares

    2009-01-01

    O presente estudo pretende analisar os factores de competitividade do sector cerâmico. Para isso, é feita uma revisão da bibliografia existente nesta área, seguida pela caracterização do sector, sendo depois utilizada uma metodologia de estudo de caso aplicada a uma empresa do subsector de pavimentos e revestimentos cerâmicos de Portugal. São analisados diversos factores, entre os quais, a fusão, tecnologia e inovação, qualidade e ambiente, recursos humanos, marketing, marca...

  15. Dificuldades de aprendizagem específicas: estudo de caso sobre dislexia

    OpenAIRE

    Costa, Florismundo Augusto da Silva

    2013-01-01

    Neste estudo abordamos aspectos relacionados com as dificuldades de aprendizagem específicas designadamente a dislexia, debruçando-nos sobre a questão conceptual, sua tipificação, etiologia e processos de avaliação e intervenção. A dislexia é uma dificuldade da aprendizagem da leitura que não se pode explicar por um défice cognitivo nem sensorial, nem por um ambiente social ou familiar desfavorável, nem por métodos de ensino desajustados. O estudo empírico que desenvolvemos, consiste na...

  16. Viver com dislexia: Estudo de um modelo empírico e da sua aplicabilidade

    OpenAIRE

    Pinto, Mónica Grasiela da Silva

    2013-01-01

    O presente trabalho incide na problemática da Dislexia, uma das Dificuldades de Aprendizagem Específicas e a mais prevalente no meio escolar. Tem com objeto de estudo um indivíduo adulto, escolarizado, cujo diagnóstico de Dislexia lhe foi conferido apenas em idade adulta, não tendo beneficiado de quaisquer adequações avaliativas ou estratégias diferenciadas de acordo com a sua problemática ao longo do seu percurso escolar. O propósito deste estudo é, pois, analisar a sua per...

  17. Perfil psicomotor em crianças com e sem autismo: um estudo comparativo

    OpenAIRE

    Coelho, Ana Paula Mendes Augusto

    2011-01-01

    O presente artigo “Perfil Psicomotor em Crianças com e sem Autismo - Um estudo comparativo” pretende diferenciar os perfis psicomotores de duas crianças: uma com autismo e outra com um desenvolvimento normativo e verificar a importância do conceito de psicomotricidade na avaliação da progressão das suas aprendizagens. A metodologia utilizada para a elaboração deste trabalho é o estudo de caso comparativo (Yin, 2001). Os instrumentos utilizados para a recolha de dados foram a BPM, (Fonseca, 20...

  18. Estudo Aerodinâmico do Transporte de Pinhas (Pinus halepensis)

    OpenAIRE

    Oliveira, Paulo Alexandre Malva

    2011-01-01

    Os incêndios florestais são uma das principais causas de devastação de grande área florestal que ocorre todos os anos. O estudo do comportamento do fogo e das suas formas de propagação, nomeadamente a ocorrência de focos secundários (spotfires), constitui-se como uma tarefa de auxílio nas estratégias de combate aos incêndios, que poderá amenizar os efeitos deste flagelo. O objectivo geral desta dissertação consiste no estudo das características aerodinâmicas das pinha...

  19. Estudo do uso de midazolam em crianças com estado de mal epileptico

    OpenAIRE

    Lohr Junior, Alfredo

    2013-01-01

    Resumo: O presente estudo teve o propósito de reavaliar o uso do midazolam em crianças com estado de mal epiléptico refratário. Foram avaliadas 50 crianças com estado de mal epiléptico, internadas na unidade de terapia intensiva do Hospital Infantil Pequeno Príncipe - Curitiba, Paraná, Brasil. O estudo foi caracterizado por dois grupos de pacientes, Grupo A - Midazolam (n=24) prospectivo, e o Grupo B - Thiopental (n=26) histórico. O Grupo Midazolam compôs-se por crianças com o diagnostico cli...

  20. GEOSSISTEMAS E CLIMATOLOGIA GEOGRÁFICA: ESTUDOS INTEGRADOS DO CLIMA EM BACIAS HIDROGRÁFICAS

    OpenAIRE

    Wesley da Silva Belizário

    2014-01-01

    Os estudos do ambiente têm sido cada vez mais frequentes, sobretudo aqueles relacionados aos impactos negativos ao ambiente natural, seja no espaço rural ou urbano. Várias contribuições teóricas têm surgido para dar sentido e embasamento para tais análises, principalmente aquelas que tentam relacionar todas as possibilidades presentes no meio, a fim de que se efetive o chamado estudo integrado do ambiente, sendo uma dessas contribuições a teoria dos geossistemas. O presente trabalho tem como ...

  1. Comite de publicacoes em estudo multicentrico e sistema informatizado de apoio - publiELSA

    OpenAIRE

    Marilia Sa Carvalho; Mauricio Lima Barreto; Claudia Medina Coeli; Rafael Monteiro Raposo; Eduardo Luiz Andrade Mota; Bruce Bartholow Duncan

    2013-01-01

    O comitê de publicações de um estudo multicêntrico visa organizar as propostas de artigos, garantindo: amplo acesso aos dados, qualidade e precedência. Foi desenvolvido um sistema online de informação e gerenciamento de propostas de estudos - o publiELSA - , composto por três módulos: (i) submissão e aprovação da proposta; (ii) acompanhamento da proposta aprovada; e (iii) relatórios consolidados. O primeiro permite a qualquer interessado buscar e conhecer artigos já publicados e em andamento,...

  2. Uso do conceito de aprendizagem em estudos relacionados ao trabalho e organizações

    OpenAIRE

    Francisco Antonio Coelho Junior; Jairo Eduardo Borges-Andrade

    2008-01-01

    A literatura em comportamento organizacional apresenta diversos estudos referenciando o conceito aprendizagem aplicado no âmbito das organizações. Porém, verifica-se o uso pouco crítico ou sistemático deste conceito. O objetivo do presente artigo consiste em realizar uma análise conceitual do termo aprendizagem, justificando sua transposição para estudos organizacionais. Aplicaram-se técnicas de análise conceitual propostas por Ryle. Como resultado, verificou-se que a natureza multifacetada d...

  3. Marketing na imprensa : os jornais na era digital : estudo de caso do Jornal I

    OpenAIRE

    Casanova, Steffany da Forte

    2014-01-01

    O presente relatório trata o estudo de caso do Jornal i, um jornal generalista, diário, português, relativamente ao marketing na imprensa e adaptação da mesma ao meio digital online. Este tema ganha importância no contexto atual da imprensa portuguesa, nomeadamente no que concerne à presença digital dos diferentes meios e ao impacto dessa mesma presença no seu sucesso. A relevância deste tema ganha maior destaque considerando o seu objeto de estudo: o Jornal i. Um jornal português, nascido si...

  4. Liderança transformacional na escola : estudo de caso sobre o Presidente de um agrupamento

    OpenAIRE

    Barreto, Ângela Teresa Dias Vasconcelos

    2009-01-01

    O presente estudo focaliza-se no estudo da liderança no caso específico de um Agrupamento Vertical de Escolas. Pretende-se compreender a forma como os docentes do Agrupamento percepcionam a liderança protagonizada pelo Presidente do Conselho Executivo, bem como o modo como essa mesma liderança é percepcionada pelo próprio. Optámos por uma investigação de carácter quantitativo. O instrumento de recolha de dados seleccionado foi o Multifactor Leadership Questionnaire (MLQ), da autoria de Bru...

  5. estudo exploratório com estudantes do 1º ciclo do ensino superior

    OpenAIRE

    Rodrigues, Maria do Rosário Queirós

    2012-01-01

    Dissertação apresentada à Universidade Fernando Pessoa, como parte dos requisitos para a obtenção do grau de Mestre em Psicologia, especialização em Psicologia do Trabalho e das Organizações Este trabalho apresenta um estudo exploratório sobre as atividades de aprendizagem e as perceções de literacia no ensino superior, tendo sido concretizado com estudantes universitários do 1º ciclo de estudos (Licenciatura) em três instituições de ensino superior, públicas e privadas, do norte do país. ...

  6. OS SISTEMAS AGROFLORESTAIS COMO ALTERNATIVA ECONÔMICA EM PEQUENAS PROPRIEDADES RURAIS: ESTUDO DE CASO

    OpenAIRE

    Mário Jorge Campos dos Santos; Samantha Nazaré de Paiva

    2002-01-01

    Os Sistemas Agroflorestais (SAFs) constituem-se em uma alternativa de uso da terra para aliar a estabilidade do ecossistema visando à eficiência e otimização de recursos naturais na produção de forma integrada e sustentada. O objetivo deste estudo de caso foi avaliar a viabilidade econômica de um sistema agroflorestal localizado na região do Pontal do Paranapanema. O SAF em estudo é formada por espécies agrícolas: milho (Zea maiz), feijão guandu (Cajanus cajan), carioquinha, (Vigna unguiculat...

  7. MARCAS DE ORALIDADE NO CADERNO KZUKA – UM OLHAR SOB A PERSPECTIVA DOS ESTUDOS CULTURAIS

    Directory of Open Access Journals (Sweden)

    Angela Dillmann Nunes Bicca

    2016-04-01

    Full Text Available Neste estudo, buscamos compreender como as marcas de oralidade presentes no jornalismo estão implicadas na constituição de identidades culturais juvenis. Sob a perspectiva dos Estudos Culturais, discutimos, a partir da abordagem discursiva da Representação Cultural, os modos como o Caderno Kzuka – periódico semanal do jornal gaúcho Zero Hora – promove uma forma de Pedagogia Cultural, ao incorporar expressões e elementos tipicamente juvenis ao texto escrito no semanário.

  8. Fitoterápicos na odontologia: estudo etnobotânico na cidade de Manaus

    OpenAIRE

    S. S. Evangelista; F.C. Sampaio; R. C. Parente; M. F. C. L. Bandeira

    2013-01-01

    O reconhecimento oficial da fitoterapia na odontologia no Brasil veio acompanhado de diversas lacunas na pesquisa científica e na utilização de plantas medicinais, especificamente para espécies vegetais com aplicação nas doenças da cavidade oral. O estado do Amazonas, especificamente a cidade de Manaus, não possui um diagnóstico da aplicabilidade de plantas medicinais nos serviços de atenção Odontológica. Esse estudo propôs realizar um estudo do tipo quali-quantitativo, descritivo e explorató...

  9. Causas de (in) sucesso escolar: Estudo de Caso de uma Escola do Concelho de Vila Real

    OpenAIRE

    Monteiro, Diana Raquel Bernardo

    2010-01-01

    Dissertação de Mestrado em Ensino da Educação Física nos Ensinos Básico e Secundário Nesta dissertação foi desenvolvido um estudo teórico baseado na problemática do (In) Sucesso Escolar, de forma a identificar os factores que influenciam o Rendimento escolar dos nossos alunos. Por este motivo procuramos clarificar o conceito de (In) sucesso Escolar baseado em estudos empíricos desenvolvidos por inúmeros autores onde pudemos constatar quais as manifestações e as causas do (In) Sucesso Esc...

  10. Generation of Monoclonal Antibodies against Non-structural Protein 3AB of Foot-and-Mouth Disease Virus

    Institute of Scientific and Technical Information of China (English)

    Tong Lin; Junjun Shao; Huiyun Chang; Shandian Gao; Guozheng Cong; Junzheng Du

    2012-01-01

    To identify linear epitopes on the non-structural protein 3AB of foot-and-mouth disease virus (FMDV),BABL/c mice were immunized with the 3AB protein and splenocytes of BALB/c mice were fused with myeloma Sp2/0 cells.Two hybridoma monoclonal antibodies (mAbs) cell lines against the 3AB protein of foot-and-mouth disease virus (FMDV) were obtained,named C6 and E7 respectively.The microneutralization titer was 1∶1024 for mAb C6,and 1∶512 for E7.Both mAbs contain kappa light chains,and were of subclass IgG2b.In order to define the mAbs binding epitopes,the reactivity of these mAbs against FMDV were examined by indirect ELISA.The results showed that both mAbs can react with FMDV,but had no cross-reactivity with Swine Vesicular Disease (SVD) antigens.The titers in abdomen liquor were 1∶5×106 for C6 and 1∶2×106 for E7.In conclusion,the mAbs obtained from this study are specific for the detection of FMDV,can be used for etiological and immunological researches on FMDV,and have potential use in diagnosis and future vaccine designs.

  11. Debates críticos: os Estudos de Segurança e o futuro dos Estudos da Paz e dos Conflitos 10.5102/uri.v11i2.2526

    Directory of Open Access Journals (Sweden)

    André Barrinha

    2013-11-01

    Full Text Available Irremediavelmente ligados pela proximidade dos respetivos objetos de estudo, Estudos de Segurança e Estudos da Paz e dos Conflitos constituíram-se e evoluíram ao longo da Guerra Fria como disciplinas antagónicas. Essa divisão operou-se sobretudo na Europa, onde Galtung e seus discípulos encaminharam o estudo das questões da guerra e da paz para uma agenda claramente normativa e crítica, enquanto o estudo das questões de segurança se centrava numa abordagem orientada para o policy-making. Como é defendido neste artigo, o final do conflito bipolar correspondeu, até certo ponto, a uma inversão de papéis, com os Estudos da Paz e dos Conflitos acomodados a um empirismo desprovido de normatividade e os Estudos de Segurança, pelo menos na Europa, a abrirem-se a novas abordagens de cariz mais crítico. É aqui sugerido que esta inversão contém, em si, importantes lições para os Estudos da Paz e da Segurança, nomeadamente sobre a centralidade da teoria na definição de uma nova agenda crítica que permita uma aproximação entre as duas disciplinas.

  12. Proteolytic Activation of Bacillus thuringiensis Cry2Ab through a Belt-and-Braces Approach.

    Science.gov (United States)

    Xu, Lian; Pan, Zhi-Zhen; Zhang, Jing; Liu, Bo; Zhu, Yu-Jing; Chen, Qing-Xi

    2016-09-28

    Proteolytic processing of Bacillus thuringiensis (Bt) crystal toxins by insect midgut proteases plays an essential role in their insecticidal toxicities against target insects. In the present study, proteolysis of Bt crystal toxin Cry2Ab by Plutella xylostella L. midgut proteases (PxMJ) was evaluated. Both trypsin and chymotrypsin were identified involving the proteolytic activation of Cry2Ab and cleaving Cry2Ab at Arg(139) and Leu(144), respectively. Three Cry2Ab mutants (R139A, L144A, and R139A-L144A) were constructed by replacing residues Arg(139), Leu(144), and Arg(139)-Leu(144) with alanine. Proteolysis assays revealed that mutants R139A and L144A but not R139A-L144A could be cleaved into 50 kDa activated toxins by PxMJ. Bioassays showed that mutants R139A and L144A were highly toxic against P. xylostella larvae, while mutant R139A-L144A was almost non-insecticidal. Those results demonstrated that proteolysis by PxMJ was associated with the toxicity of Cry2Ab against P. xylostella. It also revealed that either trypsin or chymotrypsin was enough to activate Cry2Ab protoxin. This characteristic was regarded as a belt-and-braces approach and might contribute to the control of resistance development in target insects. Our studies characterized the proteolytic processing of Cry2Ab and provided new insight into the activation of this Bt toxin. PMID:27598769

  13. HEK293 cells express dystrophin Dp71 with nucleus-specific localization of Dp71ab.

    Science.gov (United States)

    Nishida, Atsushi; Yasuno, Sato; Takeuchi, Atsuko; Awano, Hiroyuki; Lee, Tomoko; Niba, Emma Tabe Eko; Fujimoto, Takahiro; Itoh, Kyoko; Takeshima, Yasuhiro; Nishio, Hisahide; Matsuo, Masafumi

    2016-09-01

    The dystrophin gene consists of 79 exons and encodes tissue-specific isoforms. Mutations in the dystrophin gene cause Duchenne muscular dystrophy, of which a substantial proportion of cases are complicated by non-progressive mental retardation. Abnormalities of Dp71, an isoform transcribed from a promoter in intron 62, are a suspected cause of mental retardation. However, the roles of Dp71 in human brain have not been fully elucidated. Here, we characterized dystrophin in human HEK293 cells with the neuronal lineage. Reverse transcription-PCR amplification of the full-length dystrophin transcript revealed the absence of fragments covering the 5' part of the dystrophin cDNA. In contrast, fragments covering exons 64-79 were present. The Dp71 promoter-specific exon G1 was shown spliced to exon 63. We demonstrated that the Dp71 transcript comprised two subisoforms: one lacking exon 78 (Dp71b) and the other lacking both exons 71 and 78 (Dp71ab). Western blotting of cell lysates using an antibody against the dystrophin C-terminal region revealed two bands, corresponding to Dp71b and Dp71ab. Immunohistochemical examination with the dystrophin antibody revealed scattered punctate signals in the cytoplasm and the nucleus. Western blotting revealed one band corresponding to Dp71b in the cytoplasm and two bands corresponding to Dp71b and Dp71ab in the nucleus, with Dp71b being predominant. These results indicated that Dp71ab is a nucleus-specific subisoform. We concluded that Dp71, comprising Dp71b and Dp71ab, was expressed exclusively in HEK293 cells and that Dp71ab was specifically localized to the nucleus. Our findings suggest that Dp71ab in the nucleus contributes to the diverse functions of HEK293 cells.

  14. Islet biology, the CDKN2A/B locus and type 2 diabetes risk.

    Science.gov (United States)

    Kong, Yahui; Sharma, Rohit B; Nwosu, Benjamin U; Alonso, Laura C

    2016-08-01

    Type 2 diabetes, fuelled by the obesity epidemic, is an escalating worldwide cause of personal hardship and public cost. Diabetes incidence increases with age, and many studies link the classic senescence and ageing protein p16(INK4A) to diabetes pathophysiology via pancreatic islet biology. Genome-wide association studies (GWASs) have unequivocally linked the CDKN2A/B locus, which encodes p16 inhibitor of cyclin-dependent kinase (p16(INK4A)) and three other gene products, p14 alternate reading frame (p14(ARF)), p15(INK4B) and antisense non-coding RNA in the INK4 locus (ANRIL), with human diabetes risk. However, the mechanism by which the CDKN2A/B locus influences diabetes risk remains uncertain. Here, we weigh the evidence that CDKN2A/B polymorphisms impact metabolic health via islet biology vs effects in other tissues. Structured in a bedside-to-bench-to-bedside approach, we begin with a summary of the evidence that the CDKN2A/B locus impacts diabetes risk and a brief review of the basic biology of CDKN2A/B gene products. The main emphasis of this work is an in-depth look at the nuanced roles that CDKN2A/B gene products and related proteins play in the regulation of beta cell mass, proliferation and insulin secretory function, as well as roles in other metabolic tissues. We finish with a synthesis of basic biology and clinical observations, incorporating human physiology data. We conclude that it is likely that the CDKN2A/B locus influences diabetes risk through both islet and non-islet mechanisms. PMID:27155872

  15. THE EFFECT OF BLENDING SEQUENCE ON PHASE MORPHOLOGY OF NYLON 6/ABS/SMA BLENDS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The preparation process-dependent phase morphology of blends composed of nylon 6 and acryionitrile-butadienestyrene(ABS)over a composition range of 30-70 wt% using a styrene-maleic anhydride(SMA)copolymer as the compatibilizing agent with a constant content(5phr)was investigated.The results of the scanning electron microscope (SEM)observation revealed that compared with the binary blends of nylon 6 and ABS,the existence of SMA caused a composition shift of phase inversion to a higher weight fraction of nylon 6 when ABS was blended with the preblended nylon 6/SMA blend,while the co-continuous structures could be observed over a considerably narrower composition range when nylon 6 was blended with the pre-blended ABS/SMA blend.An examination through dynamic mechanical analysis (DMA)tests confirmed the results obtained with SEM.It is found that near the phase inversion region a remarkable change in the dynamic storage modulus(G')and the loss tangent(tanδ)appears.Moreover,the influence of blending sequence on the size of dispersed particles has been probed for uncompatibilized and compatibilized blends of nylon 6 and ABS over a wide range of compositions below or beyond the phase inversion points.For the blends of ABS dispersed in a nylon 6 matrix,little discernible effects of blending sequence on particle size could be observed.Furthermore,there exists a significant difference in morphologies of the blends prepared by nylon 6 particles dispersing in a ABS matrix in cases of different blending sequences used.Some possible factors responsible for the above asymmetric behaviors have been proposed.

  16. Living with an imperfect cell wall: compensation of femAB inactivation in Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Bierbaum Gabriele

    2007-09-01

    Full Text Available Abstract Background Synthesis of the Staphylococcus aureus peptidoglycan pentaglycine interpeptide bridge is catalyzed by the nonribosomal peptidyl transferases FemX, FemA and FemB. Inactivation of the femAB operon reduces the interpeptide to a monoglycine, leading to a poorly crosslinked peptidoglycan. femAB mutants show a reduced growth rate and are hypersusceptible to virtually all antibiotics, including methicillin, making FemAB a potential target to restore β-lactam susceptibility in methicillin-resistant S. aureus (MRSA. Cis-complementation with wild type femAB only restores synthesis of the pentaglycine interpeptide and methicillin resistance, but the growth rate remains low. This study characterizes the adaptations that ensured survival of the cells after femAB inactivation. Results In addition to slow growth, the cis-complemented femAB mutant showed temperature sensitivity and a higher methicillin resistance than the wild type. Transcriptional profiling paired with reporter metabolite analysis revealed multiple changes in the global transcriptome. A number of transporters for sugars, glycerol, and glycine betaine, some of which could serve as osmoprotectants, were upregulated. Striking differences were found in the transcription of several genes involved in nitrogen metabolism and the arginine-deiminase pathway, an alternative for ATP production. In addition, microarray data indicated enhanced expression of virulence factors that correlated with premature expression of the global regulators sae, sarA, and agr. Conclusion Survival under conditions preventing normal cell wall formation triggered complex adaptations that incurred a fitness cost, showing the remarkable flexibility of S. aureus to circumvent cell wall damage. Potential FemAB inhibitors would have to be used in combination with other antibiotics to prevent selection of resistant survivors.

  17. An investigation of ab initio shell-model interactions derived by no-core shell model

    Science.gov (United States)

    Wang, XiaoBao; Dong, GuoXiang; Li, QingFeng; Shen, CaiWan; Yu, ShaoYing

    2016-09-01

    The microscopic shell-model effective interactions are mainly based on the many-body perturbation theory (MBPT), the first work of which can be traced to Brown and Kuo's first attempt in 1966, derived from the Hamada-Johnston nucleon-nucleon potential. However, the convergence of the MBPT is still unclear. On the other hand, ab initio theories, such as Green's function Monte Carlo (GFMC), no-core shell model (NCSM), and coupled-cluster theory with single and double excitations (CCSD), have made many progress in recent years. However, due to the increasing demanding of computing resources, these ab initio applications are usually limited to nuclei with mass up to A = 16. Recently, people have realized the ab initio construction of valence-space effective interactions, which is obtained through a second-time renormalization, or to be more exactly, projecting the full-manybody Hamiltonian into core, one-body, and two-body cluster parts. In this paper, we present the investigation of such ab initio shell-model interactions, by the recent derived sd-shell effective interactions based on effective J-matrix Inverse Scattering Potential (JISP) and chiral effective-field theory (EFT) through NCSM. In this work, we have seen the similarity between the ab initio shellmodel interactions and the interactions obtained by MBPT or by empirical fitting. Without the inclusion of three-body (3-bd) force, the ab initio shell-model interactions still share similar defects with the microscopic interactions by MBPT, i.e., T = 1 channel is more attractive while T = 0 channel is more repulsive than empirical interactions. The progress to include more many-body correlations and 3-bd force is still badly needed, to see whether such efforts of ab initio shell-model interactions can reach similar precision as the interactions fitted to experimental data.

  18. Characterization of molecular mechanisms controlling fabAB transcription in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Herbert P Schweizer

    Full Text Available BACKGROUND: The FabAB pathway is one of the unsaturated fatty acid (UFA synthesis pathways for Pseudomonas aeruginosa. It was previously noted that this operon was upregulated in biofilms and repressed by exogenous UFAs. Deletion of a 30 nt fabA upstream sequence, which is conserved in P. aeruginosa, P. putida, and P. syringae, led to a significant decrease in fabA transcription, suggesting positive regulation by an unknown positive regulatory mechanism. METHODS/PRINCIPAL FINDINGS: Here, genetic and biochemical approaches were employed to identify a potential fabAB activator. Deletion of candidate genes such as PA1611 or PA1627 was performed to determine if any of these gene products act as a fabAB activator. However, none of these genes were involved in the regulation of fabAB transcription. Use of mariner-based random mutagenesis to screen for fabA activator(s showed that several genes encoding unknown functions, rpoN and DesA may be involved in fabA regulation, but probably via indirect mechanisms. Biochemical attempts performed did fail to isolate an activator of fabAB operon. CONCLUSION/SIGNIFICANCE: The data suggest that fabA expression might not be regulated by protein-binding, but by a distinct mechanism such as a regulatory RNA-based mechanism.

  19. 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.

  20. 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.

  1. AB Blanket for Cities (for continual pleasant weather and protection from chemical, biological and radioactive weapons)

    CERN Document Server

    Bolonkin, Alexander

    2009-01-01

    In a series of previous articles (see references) the author offered to cover a city or other important large installations or subregions by a transparent thin film supported by a small additional air overpressure under the form of an AB Dome. The building of a gigantic inflatable AB Dome over an empty flat surface is not difficult. However, if we want to cover a city, garden, forest or other obstacle course we cannot easily deploy the thin film over building or trees. In this article is suggested a new method which solves this problem. The idea is to design a double film blanket filled by light gas (for example, methane, hydrogen, or helium). Sections of this AB Blanket are lighter then air and fly in atmosphere. They can be made on a flat area (serving as an assembly area) and delivered by dirigible or helicopter to station at altitude over the city. Here they connect to the already assembled AB Blanket subassemblies, cover the city in an AB Dome and protect it from bad weather, chemical, biological and rad...

  2. 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.

  3. Electrochemical hydrogen storage performance of AB_5-CoB composites synthesized by a simple mixing method

    Institute of Scientific and Technical Information of China (English)

    SONG Dawei; WANG Yijing; WANG Yaping; JIAO Lifang; YUAN Huatang

    2009-01-01

    AB5 (MINi_(4.0)Al_(0.3)Cu_(0.5)Zn_(0.2)) alloy and CoB alloy were prepared by arc melting. AB_5-CoB composites were synthesized by simple mixing of AB_5 alloy powders and CoB alloy powders, and their electrochemical hydrogen storage properties were studied as negative electrodes in KOH aqueous solution. The maximum discharge capacity of the AB_5-CoB(50%) composite (the content of CoB in the composite is 50 wt.%) reached 365.3 mAh·g~(-1). After 100 charge-discharge cycles, the discharge capacity of the AB_5-CoB(50%) composite was still much higher than that of the AB5 alloy. The high rate discharge capability (HRD) and potentiodynamic polarzafion were also tested.

  4. 汽车ABS/ASR性能检测试验台的初步设计%A Preliminary Design for Test-bed for the Detection of Automobile ABS/ASR Performance

    Institute of Scientific and Technical Information of China (English)

    陆森兴

    2015-01-01

    Automobile ABS/ASR performance test-bed (performance test-bed for automotive anti-lock braking system/acceleration slip regulation system ), aimed at solving the problem that there is no corresponding automobile ABS/ASR performance testing equipment in respect to current technology.%汽车ABS/ASR性能检测试验台(汽车防抱死制动系统/驱动防滑控制系统性能检测试验台),旨在解决现有技术中没有相应汽车ABS/ASR性能检测设备的问题。

  5. Investimentos Socioambientais para Posicionamento de Marca: Um Estudo Sobre Imagem Organizacional

    Directory of Open Access Journals (Sweden)

    Aline Eggres de Castro

    2012-12-01

    Full Text Available O presente estudo tem como objetivo investigar se os Investimentos Socioambientais e demais ações de Responsabilidade Social Corporativa das empresas impactam positivamente na imagem organizacional delas perante seus consumidores. A Natura Cosméticos S.A. foi escolhida como objeto de estudo devido a sua forte atuação nas áreas social, ambiental e cultural no país. Para atingir os objetivos do estudo, foi realizada pesquisa survey com as consultoras (revendedoras de produtos da empresa, que se deu por meio da aplicação de questionário, elaborado a partir do modelo hipotético de pesquisa criado para o estudo. Os resultados indicam que as ações mais conhecidas pelas respondentes são as de cunho ecológico, que estão diretamente relacionadas com a identidade ligada a produtos naturais, que não agridem o meio ambiente que a empresa transmite (ou seja, são bem comunicadas e o programa “Crer para Ver”.

  6. OS SISTEMAS AGROFLORESTAIS COMO ALTERNATIVA ECONÔMICA EM PEQUENAS PROPRIEDADES RURAIS: ESTUDO DE CASO

    Directory of Open Access Journals (Sweden)

    Mário Jorge Campos dos Santos

    2002-05-01

    Full Text Available Os Sistemas Agroflorestais (SAFs constituem-se em uma alternativa de uso da terra para aliar a estabilidade do ecossistema visando à eficiência e otimização de recursos naturais na produção de forma integrada e sustentada. O objetivo deste estudo de caso foi avaliar a viabilidade econômica de um sistema agroflorestal localizado na região do Pontal do Paranapanema. O SAF em estudo é formada por espécies agrícolas: milho (Zea maiz, feijão guandu (Cajanus cajan, carioquinha, (Vigna unguiculata, preto (Phaseolus vulgaris e mandioca (Manihot esculenta com espécies florestais: Eucalyptus citriodora e Eucalyptus camaldulensis. A rentabilidade econômica do sistema foi mensurada, utilizando Valor Presente Líquido (VPL, Razão Benefício/Custo (RB/C para as culturas agrícolas anuais e Valor Esperado da terra (VET para os componentes madeireiros. Para tais cálculos foi escolhida uma taxa de desconto de 6%. O estudo demonstrou que o sistema agroflorestal apresentou rentabilidade econômica positiva, e que podem ser adotados por pequenos produtores. Assim, pode-se concluir que os sistemas agroflorestais são economicamente viáveis para pequenos produtores rurais trabalhando nas mesmas condições apresentadas neste estudo.

  7. Os sistemas agroflorestais como alternativa econômica em pequenas propriedades rurais: estudo de caso.

    Directory of Open Access Journals (Sweden)

    Mário Jorge Campos dos Santos

    2010-08-01

    Full Text Available Os Sistemas Agroflorestais (SAFs constituem-se em uma alternativa de uso da terra para aliar a estabilidade do ecossistema visando à eficiência e otimização de recursos naturais na produção de forma integrada e sustentada. O objetivo deste estudo de caso foi avaliar a viabilidade econômica de um sistema agroflorestal localizado na região do Pontal do Paranapanema. O SAF em estudo é formada por espécies agrícolas: milho (Zea maiz, feijão guandu (Cajanus cajan, carioquinha, (Vigna unguiculata, preto (Phaseolus vulgaris e mandioca (Manihot esculenta com espécies florestais: Eucalyptus citriodora e Eucalyptus camaldulensis. A rentabilidade econômica do sistema foi mensurada, utilizando Valor Presente Líquido (VPL, Razão Benefício/Custo (RB/C para as culturas agrícolas anuais e Valor Esperado da terra (VET para os componentes madeireiros. Para tais cálculos foi escolhida uma taxa de desconto de 6%. O estudo demonstrou que o sistema agroflorestal apresentou rentabilidade econômica positiva, e que podem ser adotados por pequenos produtores. Assim, pode-se concluir que os sistemas agroflorestais são economicamente viáveis para pequenos produtores rurais trabalhando nas mesmas condições apresentadas neste estudo.

  8. Estudo comparativo de planeamentos dosimétricos em carcinoma de canal anal

    OpenAIRE

    Sá, Ana Cravo; Santos, João; Gaspar, João; Monsanto, Fátima; Faria, Jorge; Coelho, Carina Marques; Cortina, Juan

    2010-01-01

    O estudo pretende avaliar, sob o ponto de vista dosimétrico, a eficácia da técnica da estrela na redução da dose nos órgãos de risco face à técnica convencional, sem comprometer a dose tumoricida nos volumes alvo, em carcinoma de canal anal.

  9. GEOSSISTEMAS E CLIMATOLOGIA GEOGRÁFICA: ESTUDOS INTEGRADOS DO CLIMA EM BACIAS HIDROGRÁFICAS

    Directory of Open Access Journals (Sweden)

    Wesley da Silva Belizário

    2014-12-01

    Full Text Available Os estudos do ambiente têm sido cada vez mais frequentes, sobretudo aqueles relacionados aos impactos negativos ao ambiente natural, seja no espaço rural ou urbano. Várias contribuições teóricas têm surgido para dar sentido e embasamento para tais análises, principalmente aquelas que tentam relacionar todas as possibilidades presentes no meio, a fim de que se efetive o chamado estudo integrado do ambiente, sendo uma dessas contribuições a teoria dos geossistemas. O presente trabalho tem como objetivos refletir sobre a teoria geossitêmica, seu surgimento, seus referenciais, suas bases, e suas contribuições para a análise e gestão de bacias hidrográficas. Da mesma forma, conceituar climatologia geográfica, relacionar com a abordagem geossitêmica e conflitar esses conceitos no sentido de seguir para a determinação das bacias hidrográficas como áreas propícias aos estudos em climatologia, tendo em vista que as bacias são unidades que englobam todos os fenômenos possíveis, espaciais, temporais, físicos, naturais, sociais, territoriais e econômicos. Nesse aspecto, as bacias hidrográficas são ambientes completos, do ponto de vista físico e social para estudos climatológicos.

  10. O uso de integradores numéricos no estudo de encontros próximos

    Directory of Open Access Journals (Sweden)

    Érica Cristina Nogueira

    2015-07-01

    Full Text Available O estudo da dinâmica do Sistema Solar necessita de integradores numéricos que reproduzam muito bem suas características dinâmicas durante um intervalo muito grande de tempo. Para o estudo de muitos problemas da dinâmica do Sistema Solar são usados integradores simpléticos, por serem muito mais rápidos do que outros integradores comuns. No entanto, estes integradores não são adequados para estudos de encontros próximos por não conseguirem manter sua precisão durante o cálculo desses encontros. Uma solução alternativa para este tipo de problema são os integradores híbridos pois eles podem resolver a questão dos encontros próximos sem perder muito da velocidade de integração. Neste trabalho, será feito uma revisão sobre a teoria dos integradores híbridos, destacando o uso do integrador MERCURY no estudo de problemas que envolvam encontros próximos.

  11. APLICAÇÃO DA FERRAMENTA FMEA: ESTUDO DE CASO EM UMA EMPRESA DO SETOR DE

    Directory of Open Access Journals (Sweden)

    Leandro Cantorski da Rosa

    2007-06-01

    Full Text Available Este trabalho apresenta um estudo de caso em que se implantou a ferramenta Failure Modes and Effects Analysis (FMEA emuma empresa atuante no segmento de transporte terrestre e aéreo de passageiros e cargas. O objetivo deste estudo de caso foideterminar, com a ferramenta FMEA, ações que minimizem ou eliminem modos de falha em potencial em um dos desdobramentos deserviços prestados pela empresa. O ponto específico onde se implantou a ferramenta foi na gestão dos pneus dos veículos de transporteterrestre de passageiros, pois falhas relacionadas a este componente aumentam os custos de manutenção da empresa e tendem a gerarinsatisfações aos clientes. Também foram utilizadas, incorporadas à ferramenta FMEA, outras ferramentas da qualidade como oBrainstorming, Diagrama de Ishikawa e Gráfico de Pareto. Os resultados do trabalho foram alcançados ao se determinar ações quetrazem consigo o objetivo principal deste estudo, isto é, o aumento de confiabilidade e qualidade do serviço prestado. Deste modo, arealização do presente estudo de caso proporcionou um maior entendimento acerca da temática proposta, além de mostrar aimportância da gestão da qualidade nos dias atuais e frente as crescentes exigências dos clientes.

  12. Transport and optical properties of warm dense aluminum in the two-temperature regime: Ab initio calculation and semiempirical approximation

    OpenAIRE

    Knyazev, D. V.; Levashov, P. R.

    2014-01-01

    This work is devoted to the investigation of transport and optical properties of liquid aluminum in the two-temperature case. At first optical properties, static electrical and thermal conductivities were obtained in the \\textit{ab initio} calculation. The \\textit{ab initio} calculation is based on the quantum molecular dynamics, density functional theory and the Kubo-Greenwood formula. The semiempirical approximation was constructed based on the results of the \\textit{ab initio} caculation. ...

  13. Electrical resistivity of NaPb compound-forming liquid alloy using ab initio pseudopotentials

    Indian Academy of Sciences (India)

    Anil Thakur; N S Negi; P K Ahluwalla

    2005-08-01

    The study of electrical resistivity of compound-forming liquid alloy, NaPb, is presented as a function of concentration. Hard sphere diameters of Na and Pb are obtained through the interionic pair potentials evaluated using Troullier and Martins ab initio pseudopotential, which have been used to calculate the partial structure factors (). Considering the liquid alloy to be a ternary mixture, Ziman formula, modified for complex formation has been used for calculating resistivity of binary liquid alloys. Form factors are calculated using ab initio pseudopotentials. The results suggest that Ziman formalism, when used with ab initio pseudopotentials, are quite successful in explaining the electrical resistivity data of compound-forming binary liquid alloys.

  14. Ab initio calculations of phosphorus and arsenic clustering parameters for the improvement of process simulation models

    Energy Technology Data Exchange (ETDEWEB)

    Sahli, Beat [Integrated Systems Laboratory, ETH Zurich, Gloriastrasse 35, 8092 Zurich (Switzerland)], E-mail: sahli@iis.ee.ethz.ch; Vollenweider, Kilian [Integrated Systems Laboratory, ETH Zurich, Gloriastrasse 35, 8092 Zurich (Switzerland); Zographos, Nikolas; Zechner, Christoph [Synopsys Switzerland LLC, Affolternstrasse 52, 8050 Zurich (Switzerland)

    2008-12-05

    We present the results of extensive ab initio simulations for phosphorus clusters, arsenic clusters and mixed phosphorus/arsenic clusters in silicon. The specific defects and the parameters that are investigated are selected according to the needs of state-of-the-art diffusion and activation models, taking into account the availability of experimental data, the capabilities of current ab initio methods and the requirements for advanced technology development. The calculated binding energies are used to determine a good starting point for the calibration of a new clustering model implemented in an atomistic process simulator. The defect species V, I, P, PV, PI, As, AsV, AsI and clusters containing up to four dopant atoms and up to one V or I are considered in all relevant charge states. The ab initio results are discussed as well as the challenges arising in the transfer of this information into the process simulation model.

  15. Adsorptive Thermodynamic Properties and Kinetics of trans-1,2- Cyclohexandiol onto AB-8 Resin

    Institute of Scientific and Technical Information of China (English)

    谢艳新; 侯丽丽; 杨倩; 蒋登高

    2012-01-01

    AB-8 resin was used as an adsorbent for the removal of trans-1,2-cyclohexandiol(CHD) from aqueous solutions.Batch experiments were carried out to investigate the effect of contact time and temperature on sorption efficiency.The adsorptive thermodynamic properties and kinetics of CHD from water onto AB-8 resin were studied.The Langmuir and Freundlich isotherm models were employed to discuss the adsorption behavior.Thermodynamic parameters such as G,H and S were calculated.The results indicate that the equilibrium data are perfectly represented by Langmuir isotherm model.Thermodynamic study reveals that it is an exothermic process in nature and mainly physical adsorption enhanced by chemisorption with a decrease of entropy process.The kinetics of CHD adsorption is well described by the pseudo second-order model.The adsorbed CHD can be eluted from AB-8 resin by 5% ethanol aqueous solution with 100% elution percentage.

  16. An Efficient Time-Stepping Scheme for Ab Initio Molecular Dynamics Simulations

    Science.gov (United States)

    Tsuchida, Eiji

    2016-08-01

    In ab initio molecular dynamics simulations of real-world problems, the simple Verlet method is still widely used for integrating the equations of motion, while more efficient algorithms are routinely used in classical molecular dynamics. We show that if the Verlet method is used in conjunction with pre- and postprocessing, the accuracy of the time integration is significantly improved with only a small computational overhead. We also propose several extensions of the algorithm required for use in ab initio molecular dynamics. The validity of the processed Verlet method is demonstrated in several examples including ab initio molecular dynamics simulations of liquid water. The structural properties obtained from the processed Verlet method are found to be sufficiently accurate even for large time steps close to the stability limit. This approach results in a 2× performance gain over the standard Verlet method for a given accuracy. We also show how to generate a canonical ensemble within this approach.

  17. 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.

  18. Hardware-in the-loop Simulator for ABS based on MATLAB/Simulink

    Institute of Scientific and Technical Information of China (English)

    Pan,Wei; Gao,jinghui; Zhou,Yafu; Song,Zhenhuan

    2003-01-01

    A method for building a Hardware-in the-loop Simulator of ABS base on MATLAB/Simulink is presented in this paper. In this method, the vehicle transmission model, the AT model and ABS algorithm is built in Simulink. This system can simulate a vehicle system in the Simulink environment. Further more, the Hardware-in the-loop Simulator system can be connected with the real ABS by I/O boards to observe the algorithm is reasonable or not. At the same time, user can simulate some different conditions by changing the parameter. The system help the user heightening the efficiency when developing the electronic device. Also, the system can be used as teaching demo software.

  19. Relativistic Two-Dimensional Harmonic Oscillator Plus Cornell Potentials in External Magnetic and AB Fields

    Directory of Open Access Journals (Sweden)

    Sameer M. Ikhdair

    2013-01-01

    Full Text Available The Klein-Gordon (KG equation for the two-dimensional scalar-vector harmonic oscillator plus Cornell potentials in the presence of external magnetic and Aharonov-Bohm (AB flux fields is solved using the wave function ansatz method. The exact energy eigenvalues and the wave functions are obtained in terms of potential parameters, magnetic field strength, AB flux field, and magnetic quantum number. The results obtained by using different Larmor frequencies are compared with the results in the absence of both magnetic field (ωL = 0 and AB flux field (ξ=0 cases. Effect of external fields on the nonrelativistic energy eigenvalues and wave function solutions is also precisely presented. Some special cases like harmonic oscillator and Coulombic fields are also studied.

  20. Semirational solutions and baseband modulational instability of the AB system in fluid mechanics

    Science.gov (United States)

    Wang, Lei; Wang, Zi-Zhe; Jiang, Dong-Yang; Qi, Feng-Hua; Guo, Rui

    2015-10-01

    Under investigation in this paper is the AB system describing marginally unstable baroclinic wave packets in geophysical fluids. By means of the n -fold modified Darboux transformation, the semirational solutions in terms of the determinants of the AB system are derived. These solutions, which are a combination of rational and exponential functions, can be used to model the nonlinear superposition of the Akhmediev breathers (or the Kuznetsov-Ma breathers) and the rogue waves. The k -order rogue wave of the AB system is produced by the interaction between the l-order rogue wave with 1/2(k-l)(k+l+1) neighboring elements in the (k-l)-order breathers (0

  1. Measurement of Ab at the Z0 resonance using a jet-charge technique

    International Nuclear Information System (INIS)

    The authors present a new preliminary measurement of the parity-violation parameter Ab using a self-calibrating jet-charge technique. In the SLD experiment they observe hadronic decays of Z0 bosons produced in collisions between longitudinally polarized electrons and unpolarized positrons a the SLAC Linear Collider. A sample of b anti b events is selected using the topologically reconstructed mass of B hadrons. From the 1997--1998 data sample of approximately 200,000 hadronic Z0 decays, they obtain Ab = 0.824 ± 0.031(stat) ± 0.032(syst). Together with the previous 1993--1995 result, it yields a preliminary combined SLD jet-charge measurement of: Ab = 0.849 ± 0.026(stat) ± 0.031(syst)

  2. Matrix Product Operators, Matrix Product States, and ab initio Density Matrix Renormalization Group algorithms

    CERN Document Server

    Chan, Garnet Kin-Lic; Nakatani, Naoki; Li, Zhendong; White, Steven R

    2016-01-01

    Current descriptions of the ab initio DMRG algorithm use two superficially different languages: an older language of the renormalization group and renormalized operators, and a more recent language of matrix product states and matrix product operators. The same algorithm can appear dramatically different when written in the two different vocabularies. In this work, we carefully describe the translation between the two languages in several contexts. First, we describe how to efficiently implement the ab-initio DMRG sweep using a matrix product operator based code, and the equivalence to the original renormalized operator implementation. Next we describe how to implement the general matrix product operator/matrix product state algebra within a pure renormalized operator-based DMRG code. Finally, we discuss two improvements of the ab initio DMRG sweep algorithm motivated by matrix product operator language: Hamiltonian compression, and a sum over operators representation that allows for perfect computational par...

  3. Crystallization of BMP receptor type IA bound to the antibody Fab fragment AbD1556

    International Nuclear Information System (INIS)

    The crystallization of BMP receptor type IA bound to the neutralizing antibody Fab fragment AbD1556 obtained by phage-display selection is reported. An antibody Fab fragment, AbD1556, was selected against the extracellular domain of BMP receptor type IA, which blocks the binding of BMP-2 to BMPR-IA and thereby neutralizes BMP-2 activity. To study the mechanism by which BMPR-IA is recognized and bound by the Fab fragment, the complex of AbD1556 bound to BMPR-IA was prepared and crystallized. Crystals of this binary complex belonged to the monoclinic space group P21, with unit-cell parameters a = 89.32, b = 129.25, c = 100.24 Å, β = 92.27°

  4. Zebrafish Rab5 proteins and a role for Rab5ab in nodal signalling.

    Science.gov (United States)

    Kenyon, Emma J; Campos, Isabel; Bull, James C; Williams, P Huw; Stemple, Derek L; Clark, Matthew D

    2015-01-15

    The RAB5 gene family is the best characterised of all human RAB families and is essential for in vitro homotypic fusion of early endosomes. In recent years, the disruption or activation of Rab5 family proteins has been used as a tool to understand growth factor signal transduction in whole animal systems such as Drosophila melanogaster and zebrafish. In this study we have examined the functions for four rab5 genes in zebrafish. Disruption of rab5ab expression by antisense morpholino oligonucleotide (MO) knockdown abolishes nodal signalling in early zebrafish embryos, whereas overexpression of rab5ab mRNA leads to ectopic expression of markers that are normally downstream of nodal signalling. By contrast MO disruption of other zebrafish rab5 genes shows little or no effect on expression of markers of dorsal organiser development. We conclude that rab5ab is essential for nodal signalling and organizer specification in the developing zebrafish embryo.

  5. 马自达626ABS/TCS系统故障自诊断与测试

    Institute of Scientific and Technical Information of China (English)

    韩双庆

    2003-01-01

    @@ 1.预诊断检查 马自达626轿车制动防抱死系统(Anti-Lock Braking System,简称ABS)和牵引力控制系统(Traction Control System,简称TCS)的控制模块是集成于一体的,记为ABS/TCS控制模块.直观检查ABS/TCS系统部件有助于识别出简单故障的原因,确保ABS/TCS警告指示灯工作正常.

  6. 基于CAN的城市客车ABS/ASR/ECB集中控制系统%ABS/ASR/ECB Integrated Control System Based on CAN for City Bus

    Institute of Scientific and Technical Information of China (English)

    匡珑; 李刚炎; 胡剑

    2008-01-01

    在分析基于CAN的ABS(Anti-Lock Braking System,防抱死制动系统)、ASR(Anti-Slide Retractor,驱动防滑控制)和ECB(Eddy Current Brake,电涡流缓速器)集中控制系统CAN总线接口的基础上,实现了基于CAN的ABS、ASR和ECB集中控制.

  7. Estudos transcriptômicos no contexto da conectividade perturbada em esquizofrenia

    Directory of Open Access Journals (Sweden)

    Andrea Schmitt

    2013-01-01

    Full Text Available Esquizofrenia é uma severa doença neurobiológica com fatores genéticos e ambientais desempenhando um papel na fisiopatologia. Diversas regiões cerebrais têm sido implicadas no processo da doença e estão conectadas em complexos circuitos neuronais. Nos níveis molecular e celular, a conectividade afetada entre essas regiões, envolvendo mielinização disfuncional dos axônios neuronais, bem como as alterações no nível sináptico e metabolismo energético levando a distúrbios na plasticidade sináptica, são os maiores achados em estudos post-mortem. Estudos de microarranjos investigando a expressão gênica contribuíram para os achados de alterações em vias complexas em regiões cerebrais relevantes na esquizofrenia. Além disso, estudos utilizando microdissecção e captura a laser permitiram a investigação da expressão gênica em grupos específicos de neurônios. Entretanto, deve ser mantido em mente que em estudos post-mortem, confusos efeitos de medicação, qualidade de RNAm, bem como capacidade de mecanismos regenerativos neuroplásticos do cérebro em indivíduos com história de vida de esquizofrenia, podem influenciar o complexo padrão de alterações no nível molecular. Apesar dessas limitações, estudos transcriptômicos livres de hipóteses em tecido cerebral de pacientes esquizofrênicos oferecem uma possibilidade única para aprender mais sobre os mecanismos subjacentes, levando a novas ópticas da fisiopatologia da doença.

  8. ORBITAL AND PHYSICAL PROPERTIES OF THE σ Ori Aa, Ab, B TRIPLE SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Simón-Díaz, S. [Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain); Caballero, J. A.; Apellániz, J. Maíz [Centro de Astrobiología (CSIC-INTA), ESAC Campus, P.O. Box 78, E-28691 Villanueva de la Cañada, Madrid (Spain); Lorenzo, J.; Negueruela, I.; Dorda, R.; Marco, A. [Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Escuela Politécnica Superior, University of Alicante, Apdo. 99, E-03080 Alicante (Spain); Schneider, F. R. N. [Argelander-Institut für Astronomie der Universität Bonn, Auf dem Hügel 71, D-53121 Bonn (Germany); Barbá, R. H. [Departamento de Física, Universidad de La Serena, Benavente 980, La Serena (Chile); Montes, D. [Departamento Astrofísica, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Pellerin, A. [Department of Physics and Astronomy, State University of New York at Geneseo, 1 College Circle, Geneseo, NY 14454 (United States); Sanchez-Bermudez, J.; Sota, A. [Instituto de Astrofísica de Andalucía (CSIC), Glorieta de la Astronomía s/n, E-18008 Granada (Spain); Sódor, Á., E-mail: ssimon@iac.es [Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, H-01121 Budapest (Hungary)

    2015-02-01

    We provide a complete characterization of the astrophysical properties of the σ Ori Aa, Ab, B hierarchical triple system and an improved set of orbital parameters for the highly eccentric σ Ori Aa, Ab spectroscopic binary. We compiled a spectroscopic data set comprising 90 high-resolution spectra covering a total time span of 1963 days. We applied the Lehman-Filhés method for a detailed orbital analysis of the radial velocity curves and performed a combined quantitative spectroscopic analysis of the σ Ori Aa, Ab, B system by means of the stellar atmosphere code FASTWIND. We used our own plus other available information on photometry and distance to the system for measuring the radii, luminosities, and spectroscopic masses of the three components. We also inferred evolutionary masses and stellar ages using the Bayesian code BONNSAI. The orbital analysis of the new radial velocity curves led to a very accurate orbital solution of the σ Ori Aa, Ab pair. We provided indirect arguments indicating that σ Ori B is a fast-rotating early B dwarf. The FASTWIND+BONNSAI analysis showed that the Aa, Ab pair contains the hottest and most massive components of the triple system while σ Ori B is a bit cooler and less massive. The derived stellar ages of the inner pair are intriguingly younger than the one widely accepted for the σ Orionis cluster, at 3 ± 1 Ma. The outcome of this study will be of key importance for a precise determination of the distance to the σ Orionis cluster, the interpretation of the strong X-ray emission detected for σ Ori Aa, Ab, B, and the investigation of the formation and evolution of multiple massive stellar systems and substellar objects.

  9. Some effects of multiple injection moulding on selected properties of ABS

    Directory of Open Access Journals (Sweden)

    M. Żenkiewicz

    2009-12-01

    Full Text Available Purpose: The purpose of this work was to investigate the influence of multiple (up to 10 times injection moulding of acrylonitrile butadiene styrene (ABS on some properties of the obtained moulded pieces.Design/methodology/approach: The investigated samples were obtained during the industrial injection moulding. There were determined the sample mechanical properties (by a tensile test, melt flow rate, temperatures of phase transitions (by differential scanning calorimetry, DSC, temperatures of thermal degradation (by thermogravimetric analysis, TGA, as well as storage modulus and damping coefficient (both by dynamic mechanical analysis, DMA.Findings: After the first injection mouldings, minor decreases (ca. 2.0 % in the tensile strength were observed. After the next injection mouldings, this quantity did not change much. The melt flow rate increased along with the number of injection mouldings. The glass transition temperatures (from DSC of butadiene and acrylonitrile styrene fractions don’t vary with the number of injection mouldings and are ca. 61 and +104ºC, respectively.Research limitations/implications: In order to confirm that degradation process occurs in ABS during injection mouldings, further investigation is necessary, mostly that on variations in the mean molecular weight of ABS.Practical implications: The studies carried out by now indicate that there are no arguments not to subject the ABS technological waste to the management by material recycling.Originality/value: It has been observed that the largest changes in the tensile strength and melt flow rate of ABS occur during its first injection moulding and a melt flow rate increases slightly with the number of injection mouldings. The temperatures of phase transitions and thermal as well as the storage modulus and damping coefficient of ABS do not essentially change after repeated injection mouldings.

  10. Antigen-Antibody Interaction Database (AgAbDb): a compendium of antigen-antibody interactions.

    Science.gov (United States)

    Kulkarni-Kale, Urmila; Raskar-Renuse, Snehal; Natekar-Kalantre, Girija; Saxena, Smita A

    2014-01-01

    Antigen-Antibody Interaction Database (AgAbDb) is an immunoinformatics resource developed at the Bioinformatics Centre, University of Pune, and is available online at http://bioinfo.net.in/AgAbDb.htm. Antigen-antibody interactions are a special class of protein-protein interactions that are characterized by high affinity and strict specificity of antibodies towards their antigens. Several co-crystal structures of antigen-antibody complexes have been solved and are available in the Protein Data Bank (PDB). AgAbDb is a derived knowledgebase developed with an objective to compile, curate, and analyze determinants of interactions between the respective antigen-antibody molecules. AgAbDb lists not only the residues of binding sites of antigens and antibodies, but also interacting residue pairs. It also helps in the identification of interacting residues and buried residues that constitute antibody-binding sites of protein and peptide antigens. The Antigen-Antibody Interaction Finder (AAIF), a program developed in-house, is used to compile the molecular interactions, viz. van der Waals interactions, salt bridges, and hydrogen bonds. A module for curating water-mediated interactions has also been developed. In addition, various residue-level features, viz. accessible surface area, data on epitope segment, and secondary structural state of binding site residues, are also compiled. Apart from the PDB numbering, Wu-Kabat numbering and explicit definitions of complementarity-determining regions are provided for residues of antibodies. The molecular interactions can be visualized using the program Jmol. AgAbDb can be used as a benchmark dataset to validate algorithms for prediction of B-cell epitopes. It can as well be used to improve accuracy of existing algorithms and to design new algorithms. AgAbDb can also be used to design mimotopes representing antigens as well as aid in designing processes leading to humanization of antibodies. PMID:25048123

  11. 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)

  12. Ab initio calculations versus polarized neutron diffraction for the spin density of free radicals

    International Nuclear Information System (INIS)

    The determination of the magnetization distribution using polarized neutron diffraction has played a key role during the last twenty years in the field of molecular magnetism. This distribution can also be obtained by first principle ab initio calculations. Such calculations always rely on approximations and the question that arises is to know whether the obtained results are reliable enough to represent accurately the properties of these molecules. The comparison between polarized neutron experimental results and ab initio calculations has turned to provide stringent tests for these methods. In the resent article a comparison between experimental and theoretical results is made and is illustrated by examples based on magnetic free radicals. (author)

  13. Attenuation coefficient determination of printed ABS and PLA samples in diagnostic radiology standard beams

    Science.gov (United States)

    Veneziani, G. R.; Corrêa, E. L.; Potiens, M. P. A.; Campos, L. L.

    2016-07-01

    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 samples 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.

  14. Exploring the ab initio/classical free energy perturbation method: The hydration free energy of water

    Science.gov (United States)

    Sakane, Shinichi; Yezdimer, Eric M.; Liu, Wenbin; Barriocanal, Jose A.; Doren, Douglas J.; Wood, Robert H.

    2000-08-01

    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

  15. Exploring the speed and performance of molecular replacement with AMPLE using QUARK ab initio protein models.

    Science.gov (United States)

    Keegan, Ronan M; Bibby, Jaclyn; Thomas, Jens; Xu, Dong; Zhang, Yang; Mayans, Olga; Winn, Martyn D; Rigden, Daniel J

    2015-02-01

    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.

  16. Attenuation coefficient determination of printed ABS and PLA samples in diagnostic radiology standard beams

    Energy Technology Data Exchange (ETDEWEB)

    Veneziani, G.R.; Correa, E.L.; Potiens, M.P.A.; Campos, L.L., E-mail: venezianigr@gmail.com [Instituto de Pesquisas Energeticas e Nucleres (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    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)

  17. An ab initio study on single electron transfer between ClO2 and phenol

    Institute of Scientific and Technical Information of China (English)

    崔崇威; 黄君礼

    2004-01-01

    The SET mechanism between chlorine dioxide (ClO2 ) and phenol was studied by using ab initio method at 4-31G* level. Geometries of the reactants, intermediate and products of the reaction were optimized and the single point energy calculations of the species were performed. The relative structure data of the reactants, intermediate and products are given. The SET mechanism between ClO2 and phenol was confirmed by ab initio calculations. The reaction is exothermic about 200. 88 k J/mol.

  18. A novel variant in CMAH is associated with blood type AB in Ragdoll cats

    OpenAIRE

    Barbara Gandolfi; Grahn, Robert A.; Gustafson, Nicholas A.; Daniela Proverbio; Eva Spada; Badri Adhikari; Janling Cheng; Gordon Andrews; Lyons, Leslie A.; Helps, Chris R.

    2016-01-01

    The enzyme cytidine monophospho-N-acetylneuraminic acid hydroxylase is associated with the production of sialic acids on cat red blood cells. The cat has one major blood group with three serotypes; the most common blood type A being dominant to type B. A third rare blood type is known as AB and has an unclear mode of inheritance. Cat blood type antigens are defined, with N-glycolylneuraminic acid being associated with type A and N-acetylneuraminic acid with type B. Blood type AB is serologica...

  19. Design of Zr-based AB2 type hydrogen storage alloys

    Institute of Scientific and Technical Information of China (English)

    文明芬; 王秋萍; 王兴海; 翟玉春; 陈廉

    2003-01-01

    The influences of the ratio of the radius of atom A(rA)to radius of atom B(rB),electronegativity and electron number were discussed on the Laves phase formation and the characteristics of Zr-based AB2 type hydrogen storage alloy.An enthalpy model of Zr-based AB2 alloy was obtained from known data and twelve Zr-based alloys were designed to test the model.The results show that the predicted values are in good agreement with the experimental values.The model can be used for predicting enthalpy values of Zr-based hydrogen storage alloys and settles a foundation for experiments.

  20. Ab Initio Calculations of Deuterium Isotope Effects on Chemical Shifts of Salt-Bridged Lysines

    DEFF Research Database (Denmark)

    Ullah, Saif; Ishimoto, Takayoshi; Williamson, Mike P.;

    2011-01-01

    Deuterium isotope effects measure the change in chemical shift on substitution of a proton by deuterium. They have been calculated by direct treatment of the H/D nuclear quantum effect using a multicomponent ab initio molecular orbital method based on a non-Born−Oppenheimer approximation. This me......Deuterium isotope effects measure the change in chemical shift on substitution of a proton by deuterium. They have been calculated by direct treatment of the H/D nuclear quantum effect using a multicomponent ab initio molecular orbital method based on a non-Born−Oppenheimer approximation...