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Sample records for regioregular polythiophene derivatives

  1. Hybrid solar cells from regioregular polythiophene and ZnO nanoparticles

    NARCIS (Netherlands)

    Beek, W.J.E.; Wienk, M.M.; Janssen, R.A.J.

    2006-01-01

    Blends of nanocryst. zinc oxide nanoparticles (nc-ZnO) and regioregular poly(3-hexylthiophene) (P3HT) processed from soln. have been used to construct hybrid polymer-metal oxide bulk-heterojunction solar cells. Thermal annealing of the spin-cast films significantly improves the solar-energy

  2. Impact of charge-transfer excitons in regioregular polythiophene on the charge separation at polythiophene-fullerene heterojunctions

    Science.gov (United States)

    Polkehn, M.; Tamura, H.; Burghardt, I.

    2018-01-01

    This study addresses the mechanism of ultrafast charge separation in regioregular oligothiophene-fullerene assemblies representative of poly-3-hexylthiophene (P3HT)-[6,6]-phenyl-C61 butyric acid methyl ester (PCBM) heterojunctions, with special emphasis on the inclusion of charge transfer excitons in the oligothiophene phase. The formation of polaronic inter-chain charge separated species in highly ordered oligothiophene has been demonstrated in recent experiments and could have a significant impact on the net charge transfer to the fullerene acceptor. The present approach combines a first-principles parametrized multi-site Hamiltonian, based on time-dependent density functional theory calculations, with accurate quantum dynamics simulations using the multi-layer multi-configuration time-dependent Hartree method. Quantum dynamical studies are carried out for up to 182 electronic states and 112 phonon modes. The present analysis follows up on our previous study of (Huix-Rotllant et al 2015 J. Phys. Chem. Lett. 6 1702) and significantly expands the scope of this analysis by including the dynamical role of charge transfer excitons. Our investigation highlights the pronounced mixing of photogenerated Frenkel excitons with charge transfer excitons in the oligothiophene domain, and the opening of new transfer channels due the creation of such charge-separated species. As a result, it turns out that the interfacial donor/acceptor charge transfer state can be largely circumvented due to the presence of charge transfer excitons. However, the latter states in turn act as a trap, such that the free carrier yield observed on ultrafast time scales is tangibly reduced. The present analysis underscores the complexity of the transfer pathways at P3HT-PCBM type junctions.

  3. Understanding defect distributions in polythiophenes via comparison of regioregular and regiorandom species

    Energy Technology Data Exchange (ETDEWEB)

    Muntasir, Tanvir, E-mail: tanvir@iastate.edu, E-mail: sumitc@iastate.edu [Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States); Chaudhary, Sumit, E-mail: tanvir@iastate.edu, E-mail: sumitc@iastate.edu [Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States); Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011 (United States)

    2015-11-28

    Organic photovoltaics (OPVs) are regarded as promising for solar-electric conversion with steadily improving power conversion efficiencies. For further progress, it is crucial to understand and mitigate defect states (traps) residing in the band-gap of OPV materials. In this work, using capacitance measurements, we analyzed two major bands in the density of states (DOS) energy spectra of defects in poly(3-hexylthiophene) (P3HT); regio-regular and regio-random species of P3HT were compared to elucidate the role of morphological disorder. To accurately interpret the obtained DOS profile, trap emission prefactors and activation energy were extracted from temperature dependent capacitance-frequency measurements, while doping, Fermi energy, built-in voltage, and energy levels of the defects were extracted from capacitance-voltage measurements. We identified that the lower energy band—misinterpreted in literature as a defect distribution—stems from free carrier response. The higher energy defect distribution band for regio-random P3HT was an order of magnitude higher than region-regular P3HT, thus stemming from morphological disorder. Impedance spectroscopy was also employed for further comparison of the two P3HT species.

  4. Understanding defect distributions in polythiophenes via comparison of regioregular and regiorandom species

    International Nuclear Information System (INIS)

    Muntasir, Tanvir; Chaudhary, Sumit

    2015-01-01

    Organic photovoltaics (OPVs) are regarded as promising for solar-electric conversion with steadily improving power conversion efficiencies. For further progress, it is crucial to understand and mitigate defect states (traps) residing in the band-gap of OPV materials. In this work, using capacitance measurements, we analyzed two major bands in the density of states (DOS) energy spectra of defects in poly(3-hexylthiophene) (P3HT); regio-regular and regio-random species of P3HT were compared to elucidate the role of morphological disorder. To accurately interpret the obtained DOS profile, trap emission prefactors and activation energy were extracted from temperature dependent capacitance-frequency measurements, while doping, Fermi energy, built-in voltage, and energy levels of the defects were extracted from capacitance-voltage measurements. We identified that the lower energy band—misinterpreted in literature as a defect distribution—stems from free carrier response. The higher energy defect distribution band for regio-random P3HT was an order of magnitude higher than region-regular P3HT, thus stemming from morphological disorder. Impedance spectroscopy was also employed for further comparison of the two P3HT species

  5. Development of Low Energy Gap and Fully Regioregular Polythienylenevinylene Derivative

    Directory of Open Access Journals (Sweden)

    Tanya M. S. David

    2014-01-01

    Full Text Available Low energy gap and fully regioregular conjugated polymers find its wide use in solar energy conversion applications. This paper will first briefly review this type of polymers and also report synthesis and characterization of a specific example new polymer, a low energy gap, fully regioregular, terminal functionalized, and processable conjugated polymer poly-(3-dodecyloxy-2,5-thienylene vinylene or PDDTV. The polymer exhibited an optical energy gap of 1.46 eV based on the UV-vis-NIR absorption spectrum. The electrochemically measured highest occupied molecular orbital (HOMO level is −4.79 eV, resulting in the lowest unoccupied molecular orbital (LUMO level of −3.33 eV based on optical energy gap. The polymer was synthesized via Horner-Emmons condensation and is fairly soluble in common organic solvents such as tetrahydrofuran and chloroform with gentle heating. DSC showed two endothermic peaks at 67°C and 227°C that can be attributed to transitions between crystalline and liquid states. The polymer is thermally stable up to about 300°C. This polymer appears very promising for cost-effective solar cell applications.

  6. Polythiophenes and fullerene derivatives based donor-acceptor system: topography by atomic force microscopy

    International Nuclear Information System (INIS)

    Marcakova, M. L.; Repovsky, D.; Cik, G.; Velic, D.

    2017-01-01

    The goal of this work is to examine the surface of a polythiophene/fullerene film in order to understand the structure. In this work polythiophene is used as electron donor and fullerene-derivative is used as electron acceptor. Atomic force microscopy (AFM), is an ideal method to study surfaces and nanostructures. Surfaces of fullerene C60 , fullerene-derivates PCBM, polythiophene P12 and a mixture of P12 and PCBM are characterized. In all samples, the average roughness, the arithmetical value of divergence from the high of the surface, is determined concluding that P12 and PCBM mix together well and form a film with specific topography. (authors)

  7. Colloidal systems of silver nanoparticles and high-regioregular cationic polythiophene with ionic-liquid-like pendant groups: Optical properties and SERS

    Czech Academy of Sciences Publication Activity Database

    Kazim, Samrana; Pfleger, Jiří; Procházka, M.; Bondarev, D.; Vohlídal, J.

    2011-01-01

    Roč. 354, č. 2 (2011), s. 611-619 ISSN 0021-9797 R&D Projects: GA AV ČR KAN100500652; GA ČR GA203/07/0717 Institutional research plan: CEZ:AV0Z40500505 Keywords : ionic conjugated polymer * polythiophene polyelectrolyte * plasmonic nanoparticle Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.070, year: 2011

  8. Colloidal systems of silver nanoparticles and high-regioregular cationic polythiophene with ionic-liquid-like pendant groups: Optical properties and SERS.

    Science.gov (United States)

    Kazim, Samrana; Pfleger, Jiří; Procházka, Marek; Bondarev, Dmitrij; Vohlídal, Jiří

    2011-02-15

    We report tuning of structure dependent optical properties of colloidal systems of borate-stabilized silver nanoparticles (Ag NPs) and polythiophene-based cationic polyelectrolyte with ionic-liquid like side groups: poly{3-[6-(1-methylimidazolium-3-yl)hexyl]thiophene-2,5-diyl bromide} (PMHT-Br) towards obtaining local electromagnetic field enhancement effects. Surface-enhanced Raman scattering (SERS) studies showed that the strong electromagnetic field enhancement is related to the formation of aggregates of Ag NPs achieved at the components ratio providing the charge balance between Ag NPs and cationic polythiophene, at which Ag NPs are nearly single-polymer-layer coated, their zeta potential is close to zero and they easily form aggregates in which the mean inter-particle distance enables the occurrence of desired plasmonic effects. Fluorescence quenching is efficient only in the systems with low concentrations of PMHT-Br, in which almost all polymer chains directly interact with the Ag NPs surface. Copyright © 2010 Elsevier Inc. All rights reserved.

  9. Synthesis, characterization and nano-structuration of poly-thiophene derivatives for organic photovoltaic solar cells

    International Nuclear Information System (INIS)

    Berson, S.

    2007-10-01

    This work is devoted to the synthesis of poly-thiophene derivatives with low bandgap and preserving high oxidation potential. Disubstituted thiophenes and 'Donor-Acceptor' bi-thiophenes were synthesized and then polymerized. The side chains of these polymers, donor or acceptor, were modified in order to tune the properties of material as well from the optical point of view as electrochemical. These polymers were also tested in blend with PCBM in bulk-heterojunction photovoltaic cells. Voc delivered by the devices showed a linear dependence according to the potential of oxidation of the polymers. Copolymers containing cyano-thiophene and alkyl- or alkoxy-thiophene showed values of 0.8 V. However, in spite of power conversion efficiency of 1 %, these performances remain lower than the one obtained with the P3HT. Optimizations in terms of morphology are certainly necessary. Indeed, the morphology of the active layer plays a key role in obtaining high power conversion efficiency. An original technique of nano-structuration of the polymer on a nano-metric scale was developed during this work, leading to the development of fibrillar P3HT. These nano-structures, presenting an important degree of order, are formed spontaneously in solution. Their rate compared to amorphous material is perfectly controllable and adjustable in solution and in solid state. Measurements of mobilities show a strong improvement of the transport of load within these fibrillar layers compared to a traditional film of P3HT obtained without annealing. Power conversion efficiencies of 3.6% on glass and 3.3 % on plastic were reached without annealing. (author)

  10. Synthesis, characterization and nano-structuration of poly-thiophene derivatives for organic photovoltaic solar cells

    International Nuclear Information System (INIS)

    Berson, S.

    2007-10-01

    This work is devoted to the synthesis of poly-thiophene derivatives with low bandgap and preserving high oxidation potential. Di-substituted thiophenes and 'Donor-Acceptor' bi-thiophenes were synthesized and then polymerized. The side chains of these polymers, donor or acceptor, were modified in order to tune the properties of material as well from the optical point of view as electrochemical. These polymers were also tested in blend with PCBM in bulk-heterojunction photovoltaic cells. Voc delivered by the devices showed a linear dependence according to the potential of oxidation of the polymers. Copolymers containing cyano-thiophene and alkyl- or alkoxy-thiophene showed values of 0.8 V. However, in spite of power conversion efficiency of 1 %, these performances remain lower than the one obtained with the P3HT. Optimizations in terms of morphology are certainly necessary. Indeed, the morphology of the active layer plays a key role in obtaining high power conversion efficiency. An original technique of nano-structuration of the polymer on a nano-metric scale was developed during this work, leading to the development of fibrillary P3HT. These nano-structures, presenting an important degree of order, are formed spontaneously in solution. Their rate compared to amorphous material is perfectly controllable and adjustable in solution and in solid state. Measurements of mobilities show a strong improvement of the transport of load within these fibrillary layers compared to a traditional film of P3HT obtained without annealing. Power conversion efficiencies of 3.6 % on glass and 3.3 % on plastic were reached without annealing. (author)

  11. Highly Regioregular Polythiophenes for Magneto-Optical Applications

    Science.gov (United States)

    2010-07-01

    magnetic moment of a nanoring of silver – with (arbitrary chosen) dimensions of the nano-doughnuts observed in P3DT film. Using the current in the ring as...be addressed now is: can we consider such a nanoring (nanostructure) as a macro-spin giving rise to magnetic properties in organic materials ? A

  12. Synthesis, characterization and nano-structuration of poly-thiophene derivatives for organic photovoltaic solar cells; Synthese, caracterisation et nanostructuration de derives du polythiophene pour des applications en cellules photovoltaiques organiques

    Energy Technology Data Exchange (ETDEWEB)

    Berson, S

    2007-10-15

    This work is devoted to the synthesis of poly-thiophene derivatives with low bandgap and preserving high oxidation potential. Disubstituted thiophenes and 'Donor-Acceptor' bi-thiophenes were synthesized and then polymerized. The side chains of these polymers, donor or acceptor, were modified in order to tune the properties of material as well from the optical point of view as electrochemical. These polymers were also tested in blend with PCBM in bulk-heterojunction photovoltaic cells. Voc delivered by the devices showed a linear dependence according to the potential of oxidation of the polymers. Copolymers containing cyano-thiophene and alkyl- or alkoxy-thiophene showed values of 0.8 V. However, in spite of power conversion efficiency of 1 %, these performances remain lower than the one obtained with the P3HT. Optimizations in terms of morphology are certainly necessary. Indeed, the morphology of the active layer plays a key role in obtaining high power conversion efficiency. An original technique of nano-structuration of the polymer on a nano-metric scale was developed during this work, leading to the development of fibrillar P3HT. These nano-structures, presenting an important degree of order, are formed spontaneously in solution. Their rate compared to amorphous material is perfectly controllable and adjustable in solution and in solid state. Measurements of mobilities show a strong improvement of the transport of load within these fibrillar layers compared to a traditional film of P3HT obtained without annealing. Power conversion efficiencies of 3.6% on glass and 3.3 % on plastic were reached without annealing. (author)

  13. Investigation on Electrochemical Properties of Polythiophene Nanocomposite with Graphite Derivatives as Supercapacitor Material on Breath Figure-Decorated PMMA Electrode

    Science.gov (United States)

    Azimi, Mona; Abbaspour, Mohsen; Fazli, Ali; Setoodeh, Hamideh; Pourabbas, Behzad

    2018-03-01

    Breath figures have been formed by the direct breath figure method on polymethyl methacrylate electrode sand hexagonal oriented holes with 0.5- to 10- μm2 surface area have been created. Deposition of materials on the electrodes has been performed by the spray-coating method. polythiophene (PTh) nanoparticles, polythiophene-graphene oxide (PTh-GO) and polythiophene-reduced graphene oxide (PTh-G) nanocomposites were synthesized by emulsion polymerization, while characterization of synthetic materials have been carried out by Fourier transform infrared, Χ-ray diffraction, transmission electron microscopy, UV-Vis spectroscopy and field emission scanning electron microscopy techniques. Also, the electrochemical properties of the designed electrodes were investigated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy techniques. Specific capacitance of porous electrodes coated by PTh nanoparticles, PTh-GO and PTh-G nanocomposites were calculated from cyclic voltammetry curves at 5 mV/s scan rate, andthe values are 3.5 F/g, 16.39 F/g, and 28.68 F/g, respectively. Also, the energy density of each electrode at 5 mV/s scan rate has been calculated and the results show that incorporation of GO and G nanolayers with PTh nanoparticles enhances the electrochemical properties of electrodes.

  14. Morphology and kinetics of aggregation of silver nanoparticles induced with regioregular cationic polythiophene

    Czech Academy of Sciences Publication Activity Database

    Kazim, Samrana; Jäger, Alessandro; Steinhart, Miloš; Pfleger, Jiří; Vohlídal, J.; Bondarev, D.; Štěpánek, Petr

    2016-01-01

    Roč. 32, č. 1 (2016), s. 2-11 ISSN 0743-7463 R&D Projects: GA ČR(CZ) GAP108/12/1143 Institutional support: RVO:61389013 Keywords : conjugated polyelectrolyte * silver nanoparticles * dynamic light scattering Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.833, year: 2016

  15. Chain ordering of regioregular polythiophene films through blending with a nickel bisdithiolene complex

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Maldonado, D. [CNRS, LCC (Laboratoire de Chimie de Coordination), 205 Route de Narbonne, F-31077 Toulouse Cedex 4 (France); Université de Toulouse, UPS, INPT, LCC, F-31077 Toulouse (France); Ramos, B.; Bedel-Pereira, E.; Séguy, I. [LAAS-CNRS, 7 Avenue du Colonel Roche, F-31077 Toulouse Cedex 4 (France); Université de Toulouse, UPS, INPT, LCC, F-31077 Toulouse (France); Villeneuve-Faure, C. [LAPLACE, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse (France); Sournia-Saquet, A.; Moineau-Chane Ching, K. I., E-mail: kathleen.chane@lcc-toulouse.fr [CNRS, LCC (Laboratoire de Chimie de Coordination), 205 Route de Narbonne, F-31077 Toulouse Cedex 4 (France); LAAS-CNRS, 7 Avenue du Colonel Roche, F-31077 Toulouse Cedex 4 (France); Alary, F.; Heully, J. L. [LCPQ-IRSAMC, 118 Route de Narbonne, F-31077 Toulouse Cedex 4 (France)

    2014-03-10

    An “annealing-free” strategy consisting of using a planar nickel bisdithiolene complex nickel bis[1,2-di(3′,4′-di-n-decyloxyphenyl)ethene-1,2-dithiolene] ([Ni(4dopedt){sub 2}]) is proposed for structuring poly(3-hexyl-thiophene) (P3HT). Photoluminescence (PL) and Raman spectroscopies, in conjunction with electronic absorption, have been used for evidencing P3HT changes due to blending. PL and absorption observations are consistent and show a correlation between polymer chain organization and increasing amounts of [Ni(4dopedt){sub 2}]. Blending with [Ni(4dopedt){sub 2}] do not modify the Raman ring-breathing modes energies indicating that blending does not induce strongly disorder in P3HT chains. Atomic force microscopic measurements show that blends nanoscale morphology presents a homogeneous matrix and small fibrils related to [Ni(4dopedt){sub 2}] concentration, especially for blends with a [Ni(4dopedt){sub 2}] weight ratio lower than 50%.

  16. Synthesis of regioregular pentacene-containing conjugated polymers

    KAUST Repository

    Okamoto, Toshihiro; Jiang, Ying; Becerril, Hector A.; Hong, Sanghyun; Senatore, Michelle L.; Tang, Ming L.; Toney, Michael F.; Siegrist, Theo; Bao, Zhenan

    2011-01-01

    We report the synthesis and characterization of a new class of regioregular pentacene-containing conjugated polymers via our synthetic routes reported previously. We found that our regioregular pentacene polymers showed improved ordering than their regiorandom counterpart as well as ambipolar OFET performance. © 2011 The Royal Society of Chemistry.

  17. Regioregular narrow-bandgap-conjugated polymers for plastic electronics

    Science.gov (United States)

    Ying, Lei; Huang, Fei; Bazan, Guillermo C.

    2017-03-01

    Progress in the molecular design and processing protocols of semiconducting polymers has opened significant opportunities for the fabrication of low-cost plastic electronic devices. Recent studies indicate that field-effect transistors and organic solar cells fabricated using narrow-bandgap regioregular polymers with translational symmetries in the direction of the backbone vector often outperform those containing analogous regiorandom polymers. This review addresses the cutting edge of regioregularity chemistry, in particular how to control the spatial distribution in the molecular structures and how this order translates to more ordered bulk morphologies. The effect of regioregularity on charge transport and photovoltaic properties is also outlined.

  18. Synthesis, characterization and comparison of polythiophene ...

    Indian Academy of Sciences (India)

    38

    Synthesis, characterization and comparison of polythiophene-carbon ... b Nanotechnology Research Institute, School of Chemical Engineering, Babol University of Technology, Babol, ..... The scan range was from −0.24 to 1.2 V in reference to.

  19. Electrical conductivity study on polythiophenes films

    International Nuclear Information System (INIS)

    Youm, I.; Cadene, M.

    1994-10-01

    The electrical conduction mechanism of two classes of polythiophenes: polythiophene (PT) and poly(3-methylthiophene) (PMT) films containing various levels of doping counter-ions was investigated. The temperature dependence of electrical conductivity obeys the Mott equation based on variable range hopping. The dimension of the variable range hopping is correlated with the structure of the conducting polymer. It seems for these polymers that carrier transport via mobile conjugational defects does not play a detectable role. (author). 17 refs, 3 figs, 1 tab

  20. Pentafluorobenzene end-group as a versatile handle for para fluoro "click" functionalization of polythiophenes.

    Science.gov (United States)

    Boufflet, Pierre; Casey, Abby; Xia, Yiren; Stavrinou, Paul N; Heeney, Martin

    2017-03-01

    A convenient method of introducing pentafluorobenzene (PFB) as a single end-group in polythiophene derivatives is reported via in situ quenching of the polymerization. We demonstrate that the PFB-group is a particularly useful end-group due to its ability to undergo fast nucleophilic aromatic substitutions. Using this molecular handle, we are able to quantitatively tether a variety of common nucleophiles to the polythiophene backbone. The mild conditions required for the reaction allows sensitive functional moieties, such as biotin or a cross-linkable trimethoxysilane, to be introduced as end-groups. The high yield enabled the formation of a diblock rod-coil polymer from equimolar reactants under transition metal-free conditions at room temperature. We further demonstrate that water soluble polythiophenes end-capped with PFB can be prepared via the hydrolysis of an ester precursor, and that such polymers are amenable to functionalization under aqueous conditions.

  1. Investigation on structural, optical and electrical properties of polythiophene-Al2O3 composites

    Science.gov (United States)

    Vijeth, H.; Yesappa, L.; Niranjana, M.; Ashokkumar, S. P.; Devendrappa, H.

    2018-05-01

    The polythiophene (PTH) and polythiophene-Al2O3 composites prepared by in situ chemical polymerisation in the presence of anionic surfactant camphor sulfonic acid (CSA). The formation of composite is confirmed by X-ray Diffraction (XRD) and Energy Dispersive X-ray spectroscopy (EDX) analysis. The surface morphology was studied using Field Emission Electron Microscopy (FESEM). Optical properties was studied using UV-visible spectroscopy, it observed decrease in the band gap reveals material has potential application in optical devices. The dielectric constant and AC conductivity of composite have been studied for different temperature in the frequency range 1 kHz -1 MHz.

  2. Structure–property relationships of electroluminescent polythiophenes

    Indian Academy of Sciences (India)

    A series of conjugated polythiophenes containing nitrogen-containing heterocycles as side chain, with differing substituent nature and linkage have been studied using quantum-chemical calculations. The optical properties of synthesized polymers were compared with that of model compounds with intricate structural ...

  3. Polythiophenes containing in-chain cobaltabisdicarbollide centers.

    Science.gov (United States)

    Fabre, Bruno; Hao, Erhong; Lejeune, Zorabel M; Amuhaya, Edith K; Barrière, Frédéric; Garno, Jayne C; Vicente, M Graça H

    2010-03-01

    New cobalt(III) bis(dicarbollide) complexes covalently linked to two 2-oligothienyl units have been synthesized and electropolymerized in acetonitrile electrolyte in order to produce the corresponding polythiophene films containing in-chain metallic centers. The polymer films electrogenerated from the bithienyl (4b) and terthienyl (4c) derivatives display redox processes attributed to the Co(III)/Co(II) couple at ca. -1.1 V vs SCE and to the p-doping/undoping of the expected quaterthienyl and sexithienyl segments at ca. 0.8 V vs SCE. In contrast, the anodic oxidation of the thienyl (4a) derivative leads to passivation of the electrode surface. As the length of the oligothiophene substituents increases, the metallic and dicarbollide cage carbon atoms contributions in the HOMO decrease dramatically so that the highest occupied frontier orbitals of 4b and 4c can be considered as almost purely oligothiophene-based. From further UV-vis spectroscopy analysis, it is demonstrated that the polymer incorporating the sexithienyl segments is more conjugated than that with the quaterthienyl segments as the absorption maximum for the interband pi-pi* transition was observed at 410 and 448 nm for poly(4b) and poly(4c) respectively. Furthermore, these polymers display a more extended degree of conjugation than the parent oligothiophenes. Such features indicate a significant electronic delocalization through the cobaltabisdicarbollide moiety. Their conducting probe atomic force microscopy characterization indicates that poly(4b) and poly(4c) behave like heavily doped semiconductors rather than pure semiconductors. Mean conductivity values extracted from the current-voltage profiles are 1.4 x 10(-4) and 7.5 x 10(-4) S cm(-1) for poly(4b) and poly(4c), respectively. Such materials are found to be efficient for the electrocatalytic reduction of protons to dihydrogen, as exemplified for poly(4b). The overpotential for hydrogen evolution is significantly decreased by ca. 230 mV with

  4. Use of Polythiophene as a Temperature Sensor

    Directory of Open Access Journals (Sweden)

    D. S. KELKAR

    2011-06-01

    Full Text Available The polythiophene was chemically synthesized using 2,5–dibromothiophene by debromination with magnesium, catalyzed by nickel chloride. The synthesized polymer was undoped using liquid ammonia and then doped again using 5 % aqueous FeCl3 for 2.5 and 5 hour duration. Characterization of undoped as well as doped samples using elemental analysis has been carried out. Elemental analysis shows that concentration of Fe+ ions increases as the duration of doping increases. All samples were pressed into pellets of about 1cm in diameter and were coated, on both sides, by aluminum using vacuum deposition technique. I – V measurements of undoped and FeCl3 doped samples, after coating have been carried out using two probe method. I – V measurements were carried out by applying +ve potential on one side from 0 V to 1 V in steps of 0.1 V and then from 1 V to 10 V in steps of 1 V. The measurements were again carried out after interchanging the polarity of the applied voltage. I – V measurements were also carried out at room temperature as well as at various temperatures in the range from 301 K to 331 K in steps of 5K. These characteristics are just similar to the characteristics of conventional p – n junction diode. The effect of doping is to reduce the knee voltage. I – V characteristics of undoped polythiophene after interchanging the polarity (like reverse bias condition in p–n junction diode at various temperature are plotted. From the graphs it is observed that the magnitude of current increases as temperature is increased. A straight line graph of temperature versus current for an applied voltage of 3 V indicates that undoped polythiophene can be used as temperature sensor in the temperature range from 301 K to 331 K.

  5. Influence of the side chain and substrate on polythiophene thin film surface, bulk, and buried interfacial structures.

    Science.gov (United States)

    Xiao, Minyu; Jasensky, Joshua; Zhang, Xiaoxian; Li, Yaoxin; Pichan, Cayla; Lu, Xiaolin; Chen, Zhan

    2016-08-10

    The molecular structures of organic semiconducting thin films mediate the performance of various devices composed of such materials. To fully understand how the structures of organic semiconductors alter on substrates due to different polymer side chains and different interfacial interactions, thin films of two kinds of polythiophene derivatives with different side-chains, poly(3-hexylthiophene) (P3HT) and poly(3-potassium-6-hexanoate thiophene) (P3KHT), were deposited and compared on various surfaces. A combination of analytical tools was applied in this research: contact angle goniometry and X-ray photoelectron spectroscopy (XPS) were used to characterize substrate dielectric surfaces with varied hydrophobicity for polymer film deposition; X-ray diffraction and UV-vis spectroscopy were used to examine the polythiophene film bulk structure; sum frequency generation (SFG) vibrational spectroscopy was utilized to probe the molecular structures of polymer film surfaces in air and buried solid/solid interfaces. Both side-chain hydrophobicity and substrate hydrophobicity were found to mediate the crystallinity of the polythiophene film, as well as the orientation of the thiophene ring within the polymer backbone at the buried polymer/substrate interface and the polymer thin film surface in air. For the same type of polythiophene film deposited on different substrates, a more hydrophobic substrate surface induced thiophene ring alignment with the surface normal at both the buried interface and on the surface in air. For different films (P3HT vs. P3KHT) deposited on the same dielectric substrate, a more hydrophobic polythiophene side chain caused the thiophene ring to align more towards the surface at the buried polymer/substrate interface and on the surface in air. We believe that the polythiophene surface, bulk, and buried interfacial molecular structures all influence the hole mobility within the polythiophene film. Successful characterization of an organic conducting

  6. Relation between Microstructure and Charge Transport in Polymers of Different Regioregularity

    KAUST Repository

    McMahon, David P.; Cheung, David L.; Goris, Ludwig; Dacuña, Javier; Salleo, Alberto; Troisi, Alessandro

    2011-01-01

    A methodology to link an atomistic description of a polymeric semiconductor with the experimental electrical characteristics of real devices is proposed. Microscopic models of poly(3-hexylthiophene) (P3HT) of different regioregularity are generated using molecular dynamics and their electronic structure determined via an approximate quantum chemistry scheme. The resulting density of trap states and distribution of localized and delocalized states is then compared with that obtained from thin film transistor measurements of P3HT at different regioregularities. The two complementary methodologies provide a converging description of the electron transport in semicrystalline P3HT and the role of regioregularity. States at the valence band edge are localized, but delocalized "band-like" states are thermally accessible and quantitatively characterized. Both theory and experiment agree that contrary to a commonly held belief the trap density and the DOS shape are little affected by the presence of regioregularity defects. © 2011 American Chemical Society.

  7. Relation between Microstructure and Charge Transport in Polymers of Different Regioregularity

    KAUST Repository

    McMahon, David P.

    2011-10-06

    A methodology to link an atomistic description of a polymeric semiconductor with the experimental electrical characteristics of real devices is proposed. Microscopic models of poly(3-hexylthiophene) (P3HT) of different regioregularity are generated using molecular dynamics and their electronic structure determined via an approximate quantum chemistry scheme. The resulting density of trap states and distribution of localized and delocalized states is then compared with that obtained from thin film transistor measurements of P3HT at different regioregularities. The two complementary methodologies provide a converging description of the electron transport in semicrystalline P3HT and the role of regioregularity. States at the valence band edge are localized, but delocalized "band-like" states are thermally accessible and quantitatively characterized. Both theory and experiment agree that contrary to a commonly held belief the trap density and the DOS shape are little affected by the presence of regioregularity defects. © 2011 American Chemical Society.

  8. Effect of regioregularity on recombination dynamics in inverted bulk heterojunction organic solar cells

    Science.gov (United States)

    Chandrasekaran, Naresh; Liu, Amelia C. Y.; Kumar, Anil; McNeill, Christopher R.; Kabra, Dinesh

    2018-01-01

    The effect of polymer regioregularity on the charge transport properties and bimolecular recombination rates of polymer-based solar cells is studied in detail using transient photovoltaic techniques. We compare organic solar cells fabricated with an ITO/ZnO/PEIE/P3HT:PCBM/MoO3/Ag structure using either 100% regioregular poly(3-hexylthiophene) (DF-P3HT) yielding an average power conversion efficiency (PCE) of 3.8  ±  0.3% or 92% regioregular P3HT (rr-P3HT) that yields an average PCE of 3.28  ±  0.4%. Transient photocurrent measurements reveal the presence of less mobile photoinduced charges in rr-P3HT:PCBM cells when compared to DF-P3HT:PCBM solar cells. Transient photovoltage measurements are used to establish the relationship between regioregularity and bimolecular recombination rate constant (k) finding that under 1 Sun, devices with high regioregularity have a longer τ despite having a higher k. The high value of k for the DF-P3HT:PCBM system as compared to the rr-P3HT:PCBM system is attributed to enhanced mobility and better charge transport of mobile charges in the DF-P3HT:PCBM system, consistent with enhanced fibrillar order in DF-P3HT films observed with transmission electron microscopy. We also note a slight decrease in cell open circuit voltage with increase in polymer regioregularity, which is due to the increase in k. Other recombination mechanisms such as trap-assisted recombination are found to be important in the lower regioregular P3HT device compounded by the reduced mobility and poor inter-chain ordering.

  9. Ultrathin regioregular poly(3-hexyl thiophene) field-effect transistors

    DEFF Research Database (Denmark)

    Sandberg, H.G.O.; Frey, G.L.; Shkunov, M.N.

    2002-01-01

    Ultrathin films of regioregular poly(3-hexyl thiophene) (RR-P3HT) were deposited through a dip-coating technique and utilized as the semiconducting film in field-effect transistors (FETs). Proper selection of the substrate and solution concentration enabled the growth of a monolayer-thick RR-P3HT...... film. Atomic force microscopy (AFM), U-V-vis absorption spectroscopy, X-ray reflectivity, and grazing incidence diffraction were used to study the growth mechanism, thickness and orientation of self-organized monolayer thick RR-P3HT films on SiO2 surfaces. Films were found to adopt a Stranski......-Krastanov-type growth mode with formation of a very stable first monolayer. X-ray measurements show that the direction of pi-stacking in the films (the (010) direction) is parallel to the substrate, which is the preferred orientation for high field-effect carrier mobilities. The field-effect mobilities in all ultrathin...

  10. Structural and electrochemical properties of polythiophene

    Energy Technology Data Exchange (ETDEWEB)

    Senthilkumar, B.; Thenamirtham, P. [Solid State Ionics and Energy Devices Laboratory, Department of Physics, Bharathiar University, Coimbatore 641 046 (India); Kalai Selvan, R., E-mail: selvankram@buc.edu.in [Solid State Ionics and Energy Devices Laboratory, Department of Physics, Bharathiar University, Coimbatore 641 046 (India)

    2011-08-15

    Polythiophenes (PTs) were prepared by chemical oxidative polymerization method in presence and absence of three different (cationic - CTAB, anionic - SDS and non-ionic - Triton X-100) surfactants using FeCl{sub 3} as oxidant. The prepared PTs were characterized by FT-IR, UV-Vis, XRD, SEM and cyclic voltammetry studies. The FT-IR spectra inferred the polymerization of thiophene and elucidate the corresponding functional groups of PTs. Our results on the UV-Vis spectra demonstrate the n-{pi}* electronic transition of the conjugated molecules. Further the red shift in the absorption peak confirms the longer conjugation length of PTs. The amorphous nature of the PTs was inferred from the XRD pattern. The PTs prepared with surfactant exhibited different morphology compared to PT prepared without surfactant. The specific capacitances (SC) of the prepared PTs were calculated using cyclic voltammetry technique, the PT prepared with TRITRON X-100 exhibited higher SC of 117 F/g compared to SC of surfactant free PT (78 F/g). Hence, the PTs prepared with surfactants were found to be suitable electrode materials for redox supercapacitors.

  11. Langmuir film of regioregular poly(4-dodecyl-2,2'-bithiophene)

    NARCIS (Netherlands)

    Greve, D.R.; Dynarowicz-Latka, P.; Dhanabalan, A.; Janssen, R.A.J.

    2002-01-01

    Regioregular poly(4-dodecyl-2,2'-bithiophene) (P4DBT) is synthesized via the McCullough polymerization route using Ni(dppp)Cl2 as a catalyst and characterized by UV–visible and nuclear magnetic resonance spectroscopy. The film-forming properties of P4DBT at the air–water interface are investigated

  12. Nanocomposites based on titanium dioxide and polythiophene: structure and properties

    Czech Academy of Sciences Publication Activity Database

    Vu, Q. T.; Pavlík, Martin; Hebestreit, N.; Rammelt, U.; Plieth, W.; Pfleger, Jiří

    2005-01-01

    Roč. 65, 1-2 (2005), s. 69-77 ISSN 1381-5148. [International Conference on Polymers and Organic Chemistry /11./. Prague, 18.06.2004-23.06.2004] R&D Projects: GA AV ČR IAA4050406 Grant - others:European Graduate School: Advanced Polymeric Materials(XE) IGK720 Institutional research plan: CEZ:AV0Z40500505 Keywords : polythiophene * titanium dioxide * nanocomposites Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.565, year: 2005

  13. Photochemical half-cells using mixture films of fullerene-ethylenediamine adduct microparticles and polythiophene

    International Nuclear Information System (INIS)

    Akiyama, Tsuyoshi; Oku, Takeo; Matsumura, Satoshi; Matsuoka, Ken-ichi; Yamada, Sunao

    2013-01-01

    In this study, C 60 fullerene–ethylenediamine adduct microparticles were prepared. Mixture films of these microparticles and polythiophene were fabricated on indium–tin-oxide transparent electrodes by spin-coating. Incorporation of C 60 –ethylenediamine microparticles was verified by scanning electron microscopy (SEM) measurements. The coverage values of these microparticles were approximately 3–17%, which were calculated from SEM images of modified electrodes. Fluorescence spectra of modified electrodes indicated that the emission intensity of polythiophene in these mixture films was apparently quenched by these C 60 –ethylenediamine microparticles as compared with a polythiophene film without these microparticles. In the presence of methylviologen, these modified electrodes generated stable photocurrent. The photoexciting species was polythiophene, which was verified by profiles of photocurrent action spectra. The C 60 –ethylenediamine microparticles substantially enhanced the photocurrent signals generated by the polythiophene-modified electrode.

  14. Conformation-related exciton localization and charge-pair formation in polythiophenes: ensemble and single-molecule study.

    Science.gov (United States)

    Sugimoto, Toshikazu; Habuchi, Satoshi; Ogino, Kenji; Vacha, Martin

    2009-09-10

    We study conformation-dependent photophysical properties of polythiophene (PT) by molecular dynamics simulations and by ensemble and single-molecule optical experiments. We use a graft copolymer consisting of a polythiophene backbone and long polystyrene branches and compare its properties with those obtained on the same polythiophene derivative without the side chains. Coarse-grain molecular dynamics simulations show that in a poor solvent, the PT without the side chains (PT-R) forms a globulelike conformation in which distances between any two conjugated segments on the chain are within the Forster radius for efficient energy transfer. In the PT with the polystyrene branches (PT-PS), the polymer main PT chain retains an extended coillike conformation, even in a poor solvent, and the calculated distances between conjugated segments favor energy transfer only between a few neighboring chromophores. The theoretical predictions are confirmed by measurements of fluorescence anisotropy and fluorescence blinking of the polymers' single chains. High anisotropy ratios and two-state blinking in PT-R are due to localization of the exciton on a single conjugated segment. These signatures of exciton localization are absent in single chains of PT-PS. Electric-field-induced quenching measured as a function of concentration of PT dispersed in an inert matrix showed that in well-isolated chains of PT-PS, the exciton dissociation is an intrachain process and that aggregation of the PT-R chains causes an increase in quenching due to the onset of interchain interactions. Measurements of the field-induced quenching on single chains indicate that in PT-R, the exciton dissociation is a slower process that takes place only after the exciton is localized on one conjugated segment.

  15. Polythiophene nanocomposites as high performance electrode material for supercapacitor application

    Science.gov (United States)

    Vijeth, H.; Niranjana, M.; Yesappa, L.; Ashokkumar, S. P.; Devendrappa, H.

    2018-04-01

    A polythiophene-aluminium oxide nanocomposite is prepared by in situ chemical polymerisation in presence of anionic surfactant camphor sulfonic acid (CSA). The characterisation of nano composite was done by X-ray Diffraction (XRD), surface morphology was studied using Atomic Force Microscopy (AFM). The electrochemical performance is evaluated using cyclic voltammetry in 1M H2SO4. As an electroactive material, it exhibits high specific capacitance of 654.5 and 757 F/g for PTH and PTHA nanocomposites at scan rate of 30mV s-1 respectively.

  16. Structural and thermal properties of carboxylic acid functionalized polythiophenes

    Directory of Open Access Journals (Sweden)

    Ariane de França Mescoloto

    2014-01-01

    Full Text Available Polythiophenes functionalized with polar groups at the end of side-chain have emerged as an alternative method to obtain good compatibility between this class of conjugated polymers and electron acceptor compounds. The aim is to prevent phase segregation and to improve the efficiency of the polythiophene technological devices. However, homopolymers synthesized from thiophene rings with high polar groups at the end of the side-chain, such as hydroxyl and carboxylic acid groups, are poorly soluble in common volatile organic solvents. We report on a systematic preparation of copolymers of 3-hexylthiophene (HT and thiophene-3-acetic acid (TAA, using different feed ratios. The chemical structures of the copolymers were confirmed by FTIR and ¹H-NMR. The TAA content in these copolymers were 33, 38 and 54 mol %. HPSEC results did not show any remarkable correlation with TAA contents in the copolymers. In contrast, the thermal analyses showed a decrease in the thermal stability and an increase in rigidity of their backbones, for the copolymers with high amounts of TAA. The solubility and optical property of copolymers were also related to the TAA contents. Thus, the properties of these copolymers can be modulated by a simple control of feed ratio of TAA in the copolymerization.

  17. Polythiophene films obtained by polymerization under atmospheric pressure plasma conditions

    Energy Technology Data Exchange (ETDEWEB)

    Teslaru, T.; Topala, I., E-mail: ionut.topala@uaic.ro; Dobromir, M.; Pohoata, V.; Curecheriu, L.; Dumitrascu, N.

    2016-02-01

    The present work describes the experimental arrangement used to initiate polymerization reactions of thiophene monomer based on a dielectric barrier discharge with plane – parallel geometry, working at atmospheric pressure in argon, in turn to obtain conductive polymeric films for different applications. The resulting plasma polymerized polythiophene (pPTh) film was characterized by FT-IR, UV–Vis, XPS spectroscopy, AFM and contact angle measurements. Characterization of pPTh films showed a higher hydrophobic character and roughness, as compared with films obtained by chemical methods, and the thickness is depending on polymerization duration. Also it can conclude that our samples represent oxidised state of pPTh. As a possible application, it analysed in situ the iodine absorption phenomenon in the pPTh matrix and its time evolution by UV–Vis spectroscopy. The presence of iodine 3d{sub 5/2} and 3d{sub 3/2} peaks in the pPTh sample after absorption was identified by XPS spectroscopy. The hydrophobic pPTh film is transformed in a super hydrophilic film after absorption of iodine vapors. - Highlights: • We obtained polythiophene films (pPTh) by atmospheric pressure plasma technique. • The pPTh films showed a hydrophobic character and conducting properties. • The pPTh films were used as sensor for iodine vapors in biological environment.

  18. Photoelectrochemical Cell of Hybrid Regioregular POLY(3-HEXYLTHIOPHENE-2,5-DIYL) and Molybdenum Disulfide Film

    Science.gov (United States)

    Abdelmola, Fatmaelzahraa M.; Ram, Manoj K.; Takshi, Arash; Stafanakos, Elias; Kumar, Ashok; Goswami, D. Yogi

    The photoelectrochemical cell attracts attention worldwide due to conversion of optical energy into electricity, production of hydrogen through water splitting and use in photodetector and photo-sensor applications. We have been working on the photochemical cell based on regioregular polyhexylthiophenes hybrid-structured films for photoelectrochemical and photovoltaic applications. This paper discusses the hybrid film studies on regioregular poly(3-hexylthiophene-2,5-diyl) (P3HT) with 2D molybdenum disulfide (MoS2) for photoelectrochemical cell. The hybrid P3HT/MoS2 films deposited over indium tin oxide (ITO)-coated glass plate or n-type silicon substrates were characterized using FTIR, UV/vis, electrochemical and scanning electron microscopy (SEM) techniques. The optical measurements showed a higher absorption magnitude with low reflection properties of P3HT/MoS2 hybrid films revealing a superior photocurrent compared to both P3HT and MoS2 films. The P3HT/MoS2 hybrid-based photoelectrochemical cell yielded a short-circuit current (Isc) of 183.16μAṡcm-2, open-circuit voltage (Voc) of 0.92V, fill factor (FF) of 25% and power conversion efficiency (η) of 0.18% under the light intensity of 242Wṡm-2. The estimated power conversion efficiency and fill factor are comparable to organic-based photovoltaic devices.

  19. Impact of regioregularity on thin-film transistor and photovoltaic cell performances of pentacene-containing polymers

    KAUST Repository

    Jiang, Ying; Hong, Sanghyun; Oh, Joon Hak; Mondal, Rajib; Okamoto, Toshihiro; Verploegen, Eric; Toney, Michael F.; McGehee, Michael D.; Bao, Zhenan

    2012-01-01

    Regioregular pentacene-containing polymers were synthesized with alkylated bithiophene (BT) and cyclopentadithiophene (CPDT) as comonomers. Among them, 2,9-conjugated polymers PnBT-2,9 and PnCPDT-2,9 achieved the best performance in transistor

  20. Polythiophenes Comprising Conjugated Pendants for Polymer Solar Cells: A Review

    Directory of Open Access Journals (Sweden)

    Hsing-Ju Wang

    2014-03-01

    Full Text Available Polythiophene (PT is one of the widely used donor materials for solution-processable polymer solar cells (PSCs. Much progress in PT-based PSCs can be attributed to the design of novel PTs exhibiting intense and broad visible absorption with high charge carrier mobility to increase short-circuit current density (Jsc, along with low-lying highest occupied molecular orbital (HOMO levels to achieve large open circuit voltage (Voc values. A promising strategy to tailor the photophysical properties and energy levels via covalently attaching electron donor and acceptor pendants on PTs backbone has attracted much attention recently. The geometry, electron-donating capacity, and composition of conjugated pendants are supposed to be the crucial factors in adjusting the conformation, energy levels, and photovoltaic performance of PTs. This review will go over the most recent approaches that enable researchers to obtain in-depth information in the development of PTs comprising conjugated pendants for PSCs.

  1. Synthesis and properties of cationic polyelectrolyte with regioregular polyalkylthiophene backbone and ionic-liquid like side groups

    Czech Academy of Sciences Publication Activity Database

    Bondarev, D.; Zedník, J.; Šloufová, I.; Sharf, Ahmed; Procházka, M.; Pfleger, Jiří; Vohlídal, J.

    2010-01-01

    Roč. 48, č. 14 (2010), s. 3073-3081 ISSN 0887-624X R&D Projects: GA AV ČR KAN100500652 Institutional research plan: CEZ:AV0Z40500505 Keywords : conjugated polymers * ionic polythiophene * optical properties Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.894, year: 2010

  2. Impact of regioregularity on thin-film transistor and photovoltaic cell performances of pentacene-containing polymers

    KAUST Repository

    Jiang, Ying

    2012-01-01

    Regioregular pentacene-containing polymers were synthesized with alkylated bithiophene (BT) and cyclopentadithiophene (CPDT) as comonomers. Among them, 2,9-conjugated polymers PnBT-2,9 and PnCPDT-2,9 achieved the best performance in transistor and photovoltaic devices respectively. The former achieved the most highly ordered structures in thin films, yielding ambipolar transistor behavior with hole and electron mobilities up to 0.03 and 0.02 cm 2 V -1 s -1 on octadecylsilane-treated substrates. The latter achieved photovoltaic power conversion efficiencies up to 0.33%. The impact of regioregularity and direction of conjugation-extension (2,9 vs. 2,10), on thin-film order and device performance has been demonstrated for the pentacene-containing polymers for the first time, providing insight towards future functional material design. © 2012 The Royal Society of Chemistry.

  3. Synthesis and characterization of polythiophene-modified TiO2 ...

    Indian Academy of Sciences (India)

    prospects and has attracted much attention for its many advantages such as ... the ground state of the polymer located in the semiconduc- tor energy gap into an .... in figure 1(c) that the polythiophene modified TiO2 nanotube arrays still keep ...

  4. Replacing Nitrogen by Sulfur: From Structurally Disordered Eumelanins to Regioregular Thiomelanin Polymers

    Directory of Open Access Journals (Sweden)

    Mariagrazia Iacomino

    2017-10-01

    Full Text Available The oxidative polymerization of 5,6-dihydroxybenzothiophene (DHBT, the sulfur analog of the key eumelanin building block 5,6-dihydroxyindole (DHI, was investigated to probe the role of nitrogen in eumelanin build-up and properties. Unlike DHI, which gives a typical black insoluble eumelanin polymer on oxidation, DHBT is converted to a grayish amorphous solid (referred to as thiomelanin with visible absorption and electron paramagnetic resonance properties different from those of DHI melanin. Mass spectrometry experiments revealed gradational mixtures of oligomers up to the decamer level. Quite unexpectedly, nuclear magnetic resonance (NMR analysis of the early oligomer fractions indicated linear, 4-, and 7-linked structures in marked contrast with DHI, which gives highly complex mixtures of partially degraded oligomers. Density functional theory (DFT calculations supported the tendency of DHBT to couple via the 4- and 7-positions. These results uncover the role of nitrogen as a major determinant of the structural diversity generated by the polymerization of DHI, and point to replacement by sulfur as a viable entry to regioregular eumelanin-type materials for potential applications for surface functionalization by dip coating.

  5. Influence of Backbone Fluorination in Regioregular Poly(3-alkyl-4-fluoro)thiophenes

    KAUST Repository

    Fei, Zhuping

    2015-06-03

    © 2015 American Chemical Society. We report two strategies toward the synthesis of 3-alkyl-4-fluorothiophenes containing straight (hexyl and octyl) and branched (2-ethylhexyl) alkyl groups. We demonstrate that treatment of the dibrominated monomer with 1 equiv of alkyl Grignard reagent leads to the formation of a single regioisomer as a result of the pronounced directing effect of the fluorine group. Polymerization of the resulting species affords highly regioregular poly(3-alkyl-4-fluoro)thiophenes. Comparison of their properties to those of the analogous non-fluorinated polymers shows that backbone fluorination leads to an increase in the polymer ionization potential without a significant change in optical band gap. Fluorination also results in an enhanced tendency to aggregate in solution, which is ascribed to a more co-planar backbone on the basis of Raman and DFT calculations. Average charge carrier mobilities in field-effect transistors are found to increase by up to a factor of 5 for the fluorinated polymers.

  6. The impact of inverse photoemission spectroscopy measurements on regioregular poly(3-hexylthiophene) films

    International Nuclear Information System (INIS)

    Li, Zhi; Schlaf, Rudy; Sun, Siqi; Li, Xiao

    2014-01-01

    Inverse photoemission spectroscopy (IPES) enables the characterization of the density of states of unoccupied energy states above the Fermi level. However, due to the relatively high electron currents required to achieve useful signal to noise ratios, sample damage is a concern. Regioregular poly(3-hexylthiophene) (rr-P3HT) was used to systematically study the influence of electron radiation during IPES measurements on a prototypical conductive polymer. A series of IPES measurements exposing the samples to a range of electron fluxes was performed. An analysis of the electronic structure and the morphology showed that significant changes occurred in the investigated samples depending on the electron flux. X-ray diffraction results revealed that the root cause of the spectral changes is most likely related to crystallization of the film in an edge-on orientation. This was confirmed by Raman spectroscopy where both the C-C and C=C stretch modes shifted to lower frequencies after 5 IPES scans indicating a more ordered molecular structure. The observation of these stretch modes even after exposure to higher electron flux indicates that the main chemical structure of the P3HT molecules remains mostly intact during the IPES measurements. The absence of significant changes in C 1s and S 2p photoemission core level lines also confirmed this conclusion

  7. Carbon nanotube-templated assembly of regioregular poly(3-alkylthiophene) in solution

    Science.gov (United States)

    Zhu, Jiahua; Stevens, Eric; He, Youjun; Hong, Kunlun; Ivanov, Ilia

    2016-09-01

    Control of structural heterogeneity by rationally encoding of the molecular assemblies is a key enabling design of hierarchical, multifunctional materials of the future. Here we report the strategies to gain such control using solution- based assembly to construct a hybrid nano-assembly and a network hybrid structure of regioregular poly(3- alkylthiophene) - carbon nanotube (P3AT-CNT). The opto-electronic performance of conjugated polymer (P3AT) is defined by the structure of the aggregate in solution and in the solid film. Control of P3AT aggregation would allow formation of broad range of morphologies with very distinct electro-optical. We utilize interactive templating to confine the assembly behavior of conjugated polymers, replacing poorly controlled solution processing approach. Perfect crystalline surface of the single-walled and multi-walled carbon nanotube (SWCNT/MWCNT) acts as a template, seeding P3AT aggregation of the surface of the nanotube. The seed continues directional growth through pi-pi stacking leading to the formation of to well-defined P3AT-CNT morphologies, including comb-like nano-assemblies, super- structures and gel networks. Interconnected, highly-branched network structure of P3AT-CNT hybrids is of particular interest to enable efficient, long-range, balanced charge carrier transport. The structure and opto-electionic function of the intermediate assemblies and networks of P3AT/CNT hybrids are characterized by transmission election microscopy and UV-vis absorption.

  8. Influence of processing and intrinsic polymer parameters on photochemical stability of polythiophene thin films

    DEFF Research Database (Denmark)

    Vesterager Madsen, Morten; Tromholt, Thomas; Böttiger, Arvid P.L.

    2012-01-01

    shielding effects were shown to have a negligible effect on the photochemical degradation rate. The results obtained in this work advance the understanding of polymer stability and will help improve the design of materials used for polymer solar cells resulting in longer lifetimes, which will push......Intrinsic polymer parameters such as regio-regularity, molecular weight, and crystallinity play an important role when studying polymer stability. 18 different batches of poly-3-hexyl-thiophene (P3HT) were degraded in a solar simulator (AM1.5G, 1000 W/m2) and the degradation kinetics were monitored....... The results suggest that the radical reaction responsible for the photodegradation takes place at terminal thiophene rings exposed at points were the conjugation is broken. This proposed mechanism is supported by the fact that stability scales with regio-regularity following the ratio of head...

  9. Novel electrical transport properties in conducting polymers such as polythiophene and Poly(3-Methylthiophene)

    International Nuclear Information System (INIS)

    Kazama, Shigeo; Masubuchi, Shin-ichi; Matsuyama, Tomochika; Matsushita, Rokuji.

    1994-01-01

    Electric transport properties in most of the conducting organic polymers have provided a riddle that prevents a thorough physical understanding of the conduction mechanism. Major difficulties for approaching the most substantial aspect in the electrical transport properties underlie in complicated higher order structure inherent to polymeric materials consisting of crystalline regions entangled with disordered amorphous regions. In order to clearly understand the origin of the metallic nature of conducting polymers, we have to extract the proper transport properties characteristics of the ordered crystalline regions. We have made a series of experimental studies of the transport properties in conductive polythiophene and poly(3-methylthiophene) obtained with the electrochemical polymerization. For polythiophene, we have investigated both the as-grown samples and the ones that contain controlled amount of dopant species exchanged after the neutralization aiming to see the effect of dopant concentration on the transport properties. (author)

  10. Polythiophene-carbon nanotubes composites as energy storage materials for supercapacitor application

    International Nuclear Information System (INIS)

    Thakur, A. K.; Choudhary, R. B.; Sartale, S. D.; Desai, Mangesh

    2016-01-01

    Polythiophene incorporated carbon materials have sought huge attention due to various improved electrochemical properties including enhanced electrical conductivity. Our work includes the synthesis of polythiophene (PTP)-multi-wallcarbon nanotubes (MWCNTs) via in-situ polymerization method. The homogeneous distribution of MWCNT in PTP was confirmed by Field Emission Scanning Electron Microscope (FESEM). Examination of the specimen using X-Ray diffraction (XRD), Fourier Transform-Infrared (FTIR) and Raman spectroscopy confirmed the composite formation. Other electrochemical characterizations like electrochemical impendence spectroscopy (EIS) and cyclic voltammetry (CV)of the PTP-MWCNT composite affirmed that incorporation of MWCNT improves the electrochemical properties of neat PTP including a significant increase in the capacitance. Hence making PTP-MWCNT isa better material for supercapacitor application than neat PTP.

  11. Optical rotation and electron spin resonance of an electro-optically active polythiophene

    International Nuclear Information System (INIS)

    Goto, Hiromasa

    2010-01-01

    Graphical abstract: The electro-chiroptical polythiophene displays optical rotation at wavelengths corresponding to the doping band observable in the absorption spectra. The formation of polarons on the main-chain is confirmed by electron spin resonance measurements. - Abstract: A chiroptical polythiophene, is synthesized by electrolytic polymerization in a cholesteric liquid crystal electrolyte solution. The polymer displays a fingerprint texture similar to that of the cholesteric electrolyte solution. Upon electrochemical doping, the polymer displays optical rotation at wavelengths corresponding to the doping band observable in the absorption spectra. The formation of polarons on the main-chain is confirmed by electron spin resonance measurements. The results demonstrate the intermolecular chirality of polarons in this π-conjugated polymer, indicating continuum delocalized polarons are in a three-dimensional helical environment.

  12. Polythiophene-carbon nanotubes composites as energy storage materials for supercapacitor application

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, A. K., E-mail: anukulphyism@gmail.com; Choudhary, R. B. [CPESM-DR Laboratory, Department of Applied Physics, Indian school of mines Dhanbad-826004,India (India); Sartale, S. D.; Desai, Mangesh [Thin Films and Nanomaterials LaboratoryDepartment of Physics,Savitribai Phule Pune University, Pune-411007 (India)

    2016-05-06

    Polythiophene incorporated carbon materials have sought huge attention due to various improved electrochemical properties including enhanced electrical conductivity. Our work includes the synthesis of polythiophene (PTP)-multi-wallcarbon nanotubes (MWCNTs) via in-situ polymerization method. The homogeneous distribution of MWCNT in PTP was confirmed by Field Emission Scanning Electron Microscope (FESEM). Examination of the specimen using X-Ray diffraction (XRD), Fourier Transform-Infrared (FTIR) and Raman spectroscopy confirmed the composite formation. Other electrochemical characterizations like electrochemical impendence spectroscopy (EIS) and cyclic voltammetry (CV)of the PTP-MWCNT composite affirmed that incorporation of MWCNT improves the electrochemical properties of neat PTP including a significant increase in the capacitance. Hence making PTP-MWCNT isa better material for supercapacitor application than neat PTP.

  13. Enhanced visible-light photocatalysis and gas sensor properties of polythiophene supported tin doped titanium nanocomposite

    Science.gov (United States)

    Chandra, M. Ravi; Siva Prasada Reddy, P.; Rao, T. Siva; Pammi, S. V. N.; Siva Kumar, K.; Vijay Babu, K.; Kiran Kumar, Ch.; Hemalatha, K. P. J.

    2017-06-01

    The polythiophene supported tin doped titanium nanocomposites (PTh/Sn-TiO2) were synthesized by modified sol-gel process through oxidative polymerization of thiophene. The fourier transform infrared spectroscopy (FT-IR) and UV-Vis diffuse reflectance spectroscopy (UV-DRS) analysis confirms the existence of synergetic interaction between metal oxide and polymer along with extension of absorption edge to visible region. The composites are found to be in spherical form with core-shell structure, which is confirmed by scanning electron spectroscopy (SEM) and transmission electron microscopy (TEM) images, the presence of all respective elements of composite are proven by energy-dispersive X-ray spectroscopy (EDX) analysis. The importance of polythiophene on surface of metal oxide has been were studied as a function of photocatalytic activity for degradation of organic pollutant congo red and gas sensor behavior towards liquid petroleum gas (LPG). All the composites are photocatalytically active and the composite with 1.5 wt% thiophene degrades the pollutant congo red within 120 min when compared to remaining catalysts under visible light irradiation. On the other hand, same composite have shown potential gas sensor properties towards LPG at 300 °C. Considering all the results, it can be noted that polythiophene acts as good sensitizer towards LPG and supporter for the tin doped titania that improve the photocatalytic activity under visible light.

  14. Structural, photoconductivity, and dielectric studies of polythiophene-tin oxide nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Murugavel, S., E-mail: starin85@gmail.com; Malathi, M., E-mail: mmalathi@vit.ac.in

    2016-09-15

    Highlights: • Synthesis of polythiophene-tin oxide nanocomposites confirmed by FTIR and EDAX. • SEM shows SnO{sub 2} nanoparticles embedded within polythiophene matrix. • Stability and isoelectric point suggest nanoparticle–matrix interaction. • High dielectric constant due to high Maxwell–Wagner interfacial polarization. - Abstract: Polythiophene-tinoxide (PT-SnO{sub 2}) nanocomposites were prepared by in situ chemical oxidative polymerization, in the presence of various concentrations of SnO{sub 2} nanoparticles. Samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy and Zeta potential measurements. Morphologies and elemental compositions were investigated by transmission electron microscopy, field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. The photoconductivity of the nanocomposites was studied by field-dependent dark and photo conductivity measurements. Their dielectric properties were investigated using dielectric spectroscopy, in the frequency range of 1kHz–1 MHz. The results indicated that the SnO{sub 2} nanoparticles in the PT-SnO{sub 2} nanocomposite were responsible for its enhanced dielectric performance.

  15. Encapsulation of Polythiophene by Glycopolymer for Water Soluble Nano-wire

    Energy Technology Data Exchange (ETDEWEB)

    T Fukuda; Y Inoue; T Koga; M Matsuoka; Y Miura

    2011-12-31

    A water-soluble polythiophene (PT) was prepared by the self-assembling complex with a glycopolymer. The glycopolymer of poly(N-p-vinylbenzyl-D-lactonamide) (PVLA) formed self-assembling cylindrical structure based on the amphiphilicity even after the complexation with PT. We confirmed the improved optical functionality of PT due to the longer conjugated {pi}-orbital. It suggested that PT behaved like molecular nanowire with the self-assembled structure in the hydrophobic core of PVLA. PVLA-PT also showed specific biorecognition against corresponding lectin. These results suggested that the bioactive nanowire formation of PT with the glycopolymer was developed.

  16. Characteristics of Electro-Optic Device Using Conducting Polymers, Polythiophene and Polypyrrole Films

    Science.gov (United States)

    Kaneto, Keiichi; Yoshino, Katsumi; Inuishi, Yoshio

    1983-07-01

    Detailed characteristics of electro-optic elements (color switching and memory) utilizing the spectral change of conducting polymers by electrochemical doping and undoping are studied. The response time of color switching, for example, red≤ftrightarrowblue in polythiophene film in the electrolyte of LiBF4/acetonitrile is 30˜100 msec under the applied voltages of -2.0{≤ftrightarrow}+4.0 V vs. Li plate. More than 103 cycles of color switch are observed quite reproducibly. Three color states of yellow green, dark brown and blue are demonstrated for polypyrrole film.

  17. Printed biotin-functionalised polythiophene films as biorecognition layers in the development of paper-based biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Ihalainen, Petri, E-mail: petri.ihalainen@abo.fi [Laboratory of Physical Chemistry, Center for Functional Materials, Åbo Akademi University, Turku (Finland); Pesonen, Markus [Physics, Center for Functional Materials, Åbo Akademi University, Turku (Finland); Sund, Pernilla [Laboratory of Polymer Technology, Center for Functional Materials, Åbo Akademi University, Turku (Finland); Viitala, Tapani [Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Helsinki (Finland); Määttänen, Anni; Sarfraz, Jawad [Laboratory of Physical Chemistry, Center for Functional Materials, Åbo Akademi University, Turku (Finland); Wilén, Carl-Erik [Laboratory of Polymer Technology, Center for Functional Materials, Åbo Akademi University, Turku (Finland); Österbacka, Ronald [Physics, Center for Functional Materials, Åbo Akademi University, Turku (Finland); Peltonen, Jouko [Laboratory of Physical Chemistry, Center for Functional Materials, Åbo Akademi University, Turku (Finland)

    2016-02-28

    Highlights: • Inkjet-printed polythiophene films show good adhesion on ultrathin gold films. • Biotin-functionalisation of polythiophene enables specificity towards streptavidin. • Supramolecular biorecognition architectures can be prepared by printing. • The addition of each printed layer can be followed by a change in capacitance. - Abstract: The integration of flexible electronic sensors in clinical diagnostics is visioned to significantly reduce the cost of many diagnostic tests and ultimately make healthcare more accessible. This study concentrates on the characterisation of inkjet-printed bio-functionalised polythiophene films on paper-based ultrathin gold film (UTGF) electrodes and their possible application as biorecognition layers. Physicochemical surface properties (topography, chemistry, and wetting) and electrochemical characteristics of water-soluble regioirregular tetraethylene-glycol polythiophene (TEGPT) and biotin-functionalised TEGPT (b-TEGPT) films were examined and compared. In addition, their specificity towards streptavidin protein was tested. The results show that stable supramolecular biorecognition layers of insulating b-TEGPT and streptavidin were successfully fabricated on a paper-based UTGF by inkjet-printing. Good adhesion of thiophene to UTGF can be attributed to covalent linkage between sulphur and gold, whereas the stability of the streptavidin layer is due to the high affinity between biotin and streptavidin. The device introduced can be utilised in the development of biosensors for clinically relevant analytes e.g. for detecting complementary DNA oligomers or antibody–antigen complexes.

  18. Fabrication of molecular hybrid films of gold nanoparticle and polythiophene by covalent assembly

    Energy Technology Data Exchange (ETDEWEB)

    Sundaramurthy, Jayaraman, E-mail: jsu2@np.edu.sg [Department of Chemical & Biomolecular Engineering, National University of Singapore, Block E5, 4 Engineering Drive 4, 117576 (Singapore); Environmental & Water Technology Centre of Innovation, Ngee Ann Polytechnic, 599489 (Singapore); Dharmarajan, Rajarathnam [CERAR, University of South Australia, Mawson Lakes, SA 5095 (Australia); Srinivasan, M.P., E-mail: chesmp@nus.edu.sg [Department of Chemical & Biomolecular Engineering, National University of Singapore, Block E5, 4 Engineering Drive 4, 117576 (Singapore)

    2015-08-31

    This work demonstrates the fabrication of molecular hybrid films comprising gold nanoparticles (AuNPs) incorporated in covalently assembled, substituted polythiophene (poly(3-(2-bromoethoxy)ethoxymethylthiophene-2,5-diyl (PBrEEMT))) films by different surface chemistry routes. AuNPs are incorporated in the immobilized polythiophene matrix due to its affinity for amine and sulfur. The amount of AuNPs present depends on the nature of the incorporation, the extent of film coverage and interaction of thiophene and amine groups. PBrEEMT films functionalized with amine rich polyallylamine immobilize greater numbers of AuNPs due to more extensive gold–amine interactions. Covalent binding between AuNP and PBrEEMT films was accomplished by using pre-functionalised AuNPs (4-aminothiophenol functionalized AuNPs). Atomic force microscopy, field emission scanning electron microscopy and X-ray photoelectron spectroscopy were used to study the morphology and chemical constituents of assembled films. These approaches will pave the way for developing facile methods for nanoparticle incorporation and will also facilitate direct interaction of nanoparticles with the conducting polymer matrix and enhance the electrical properties of the films. - Highlights: • Covalent molecular assembly enabled the fabrication of molecular hybrid films. • Monomeric and polymeric species were employed as intermediate linkers. • Adopted approaches facilitated the direct interaction of gold nanoparticle in films. • The amount of nanoparticle incorporation depended on the extent of film coverage.

  19. Application of polythiophene to methanol vapor detection: an ab initio study.

    Science.gov (United States)

    Shokuhi Rad, Ali

    2015-11-01

    The interaction of methanol with terthiophene (3PT; a model of polythiophene) was investigated using density functional theory (DFT) at the BLYP-D3/6-31+G(d,p) level of theory. The computed density of states (DOS) pointed to considerable orbital hybridization upon the interaction of methanol with 3PT. Natural population analysis (NPA) was used to determine the charge distribution as well as the net charge transfer within the 3PT-methanol system, and thus to assess the sensing ability of terthiophene. The computed dipole moment revealed that the dielectric μ D changes upon the interaction of methanol with 3PT. Using calculated changes in the HOMO-LUMO energy gap, it was deduced that the electronic properties of 3PT are sensitive to the interaction of 3PT with methanol. After full energy relaxation, the interaction energy of methanol with 3PT in the most stable configuration was calculated to be -16.4 (counterpoise-corrected energy: -13.5) kJ mol(-1), providing proof that methanol is physisorbed by 3PT. Graphical Abstract Adsorption of methanol on polythiophene.

  20. A star-shaped polythiophene dendrimer coating for solid-phase microextraction of triazole agrochemicals.

    Science.gov (United States)

    Abolghasemi, Mir Mahdi; Habibiyan, Rahim; Jaymand, Mehdi; Piryaei, Marzieh

    2018-02-14

    A nanostructured star-shaped polythiophene dendrimer was prepared and used as a fiber coating for headspace solid phase microextraction of selected triazolic pesticides (tebuconazole, hexaconazole, penconazole, diniconazole, difenoconazole, triticonazole) from water samples. The dendrimer with its large surface area was characterized by thermogravimetric analysis, UV-Vis spectroscopy and field emission scanning electron microscopy. It was placed on a stainless steel wire for use in SPME. The experimental conditions for fiber coating, extraction, stirring rate, ionic strength, pH value, desorption temperature and time were optimized. Following thermal desorption, the pesticides were quantified by GC-MS. Under optimum conditions, the repeatability (RSD) for one fiber (for n = 3) ranges from 4.3 to 5.6%. The detection limits are between 8 and 12 pg mL -1 . The method is fast, inexpensive (in terms of equipment), and the fiber has high thermal stability. Graphical abstract Schematic presentation of a nanostructured star-shaped polythiophene dendrimer for use in headspace solid phase microextraction of the triazolic pesticides (tebuconazole, hexaconazole, penconazole, diniconazole, difenoconazole, triticonazole). They were then quantified by gas chromatography-mass spectrometry.

  1. Evolution of in situ conductivity of polythiophene deposits by potential cycling

    Energy Technology Data Exchange (ETDEWEB)

    Zotti, G.; Schiavon, G. (Ist. di Polarografia ed Elettrochimica Preparativa, Consiglio Nazionale delle Ricerche, Padua (Italy))

    1990-12-01

    In situ conductivity of polythiophene (PT) deposits from anodic coupling of thiophene (T), bithiophene (BT) and terthiophene (TT) increases with redox switching to an extent which depends on the monomer. Changes are considerable with TT, minor with BT and negligible with T, involving extra oxidative charges with the same trend, and are paralleled by evolution of electronic and infrared spectra and cyclic voltammograms. Results are explained by the occurrence of solid-state polymerization of oligomers leading ultimately to the same polymer with a conductivity of 1-3 S cm{sup -1}. PT from thiophene is much less conducting (0.06 S cm{sup -1}), because of oxidative degradation during deposition. (orig.).

  2. Low coercive field and conducting nanocomposite formed by Fe3O4 and poly(thiophene)

    International Nuclear Information System (INIS)

    Silva, R.A.; Santos, M.J.L.; Rinaldi, A.W.; Zarbin, A.J.G.; Oliveira, M.M.; Santos, I.A.; Cotica, L.F.; Coellho, A.A.; Rubira, A.F.; Girotto, E.M.

    2007-01-01

    Magnetite and poly(thiophene) composites have been produced by in situ monomer oxidation. Fourier transform infrared (FTIR) and X-ray diffraction (XRD) confirmed the presence of Fe 3 O 4 as particle agglomerates ranging from 15 to ca. 54 nm in size. Transmission electron micrographs (TEMs) revealed a face-to-face structure in both the pure magnetite and the nanocomposite. Typical superparamagnetic (ferrimagnetic) curves have been observed, whereas the relatively weak magnetic field employed in measurement, 200 Oe, was sufficient to split the curves completely. Zero field cooling (ZFC) and field cooling (FC) curves coincide only above room temperature, indicating that the characteristic blocking temperature (T B ) for superparamagnetic particles in this assembly is above room temperature. - Graphical abstract: TEM image of magnetite/poly(thiophene) nanocomposite

  3. Graphene-induced band gap renormalization in polythiophene: a many-body perturbation study

    Science.gov (United States)

    Marsusi, F.; Fedorov, I. A.; Gerivani, S.

    2018-01-01

    Density functional theory and many-body perturbation theory at the G0W0 level are employed to study the electronic properties of polythiophene (PT) adsorbed on the graphene surface. Analysis of the charge density difference shows that substrate-adsorbate interaction leads to a strong physisorption and interfacial electric dipole moment formation. The electrostatic potential displays a  -0.19 eV shift in the graphene work function from its initial value of 4.53 eV, as the result of the interaction. The LDA band gap of the polymer does not show any change. However, the band structure exhibits weak orbital hybridizations resulting from slight overlapping between the polymer and graphene states wave functions. The interfacial polarization effects on the band gap and levels alignment are investigated at the G0W0 level and show a notable reduction of PT band gap compared to that of the isolated chain.

  4. Conductivity study of thermally stabilized RuO2/polythiophene nanocomposites

    Science.gov (United States)

    Hebbar, Vidyashree; Bhajantri, R. F.

    2018-04-01

    The polymer nanocomposites of Ruthenium oxide (RuO2) filled polythiophene (PT) were synthesized by polymerization using chemical method. The purity of the synthesized polymer composite is verified using X-Ray diffraction (XRD). The structural discrepancies of the RuO2 filled PT composites are studied by Fourier transform infrared (FT-IR) spectroscopy. The phase transition and thermal stability of the prepared composite is revised by thermal characterization such as differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The DC conductivity of RuO2 filled PT composite in the form of pellets is calculated using current-voltage (I-V) characterization by two-probe method. The enhancement in conductivity with increased RuO2 content in PT matrix is examined, which is the required property for electrical and electronic applications in supercapacitors.

  5. Large thermoelectric efficiency of doped polythiophene junction: A density functional study

    Science.gov (United States)

    Golsanamlou, Zahra; Bagheri Tagani, Meysam; Rahimpour Soleimani, Hamid

    2018-06-01

    The thermoelectric properties of polythiophene (PT) coupled to the Au (111) electrodes are studied based on density functional theory with nonequilibrium Green function formalism. Specially, the effect of Li and Cl adsorbents on the thermoelectric efficiency of the PT junction is investigated in different concentrations of the dopants for two lengths of the PT. Results show that the presence of dopants can bring the structural changes in the oligomer and modify the arrangement of the molecular levels leading to the dramatic changes in the transmission spectra of the junction. Therefore, the large enhancement in thermopower and consequently figure of merit is obtained by dopants which makes the doped PT junction as a beneficial thermoelectric device.

  6. Phenyl vs Alkyl Polythiophene: A Solar Cell Comparison Using a Vinazene Derivative as Acceptor

    KAUST Repository

    Woo, Claire H.; Holcombe, Thomas W.; Unruh, David A.; Sellinger, Alan; Fréchet, Jean M. J.

    2010-01-01

    The solar cell performance of poly[3-(4-n-octyl)-phenylthiophene] (POPT) and poly(3hexylthiophene) (P3HT) are compared in devices using 4,7-bis(2-(l-(2-ethylhexyl)-4,5-dicyanoimidazol-2-yl)vinyi)benzo[c][l,2,5] -thiadiazole (EV-BT) as the electron acceptor. Despite their reduced light absorption, POPT:EV-BT devices generate higher photocurrents in both bilayer and bulk heterojunction (BHJ) architectures than analogous P3HT:EV-BT devices. Optimized POPT:EV-BT BHJ devices achieve 1.4% average efficiency, whereas the analogous P3HT devices only reach 1.1%. Morphology does not account for the large difference in performance as AFM studies of the active layer suggest, comparable levels of phase separation in the two systems. Reverse bias analysis demonstrates that P3HT devices have a higher maximum potential than POPT devices, but P3HT devices appear to be more severely limited by recombination losses under standard operating conditions. A possible explanation for the superior performance in POPT devices is that the pendant phenyl ring in POPT can twist out-of-plane and increase the separation distance with the acceptor molecule. A larger donor/acceptor separation distance can destabilize the geminate pair and lead to more efficient charge separation in POPT:EV-BT devices. Our results emphasize the importance of donor/acceptor pair interactions and its effect on charge separation, processes in polymer solar cells. © 2010 American Chemical Society.

  7. Polythiophene Derivative with a Side Chain Chromophore as Photovoltaic and Photorefractive Materials

    Science.gov (United States)

    1993-11-17

    the desired bulk property in the polymer such as water solubility,1 8 optical activity,19 ionic conductivity 20 or liquid crystalline properties. 2 1...photoexcitation, which is similar to photoinduced polarization observed in the Langmuir - Blodgett (L-B) films of donor-acceptor molecules. 23 But due to

  8. Phenyl vs Alkyl Polythiophene: A Solar Cell Comparison Using a Vinazene Derivative as Acceptor

    KAUST Repository

    Woo, Claire H.

    2010-03-09

    The solar cell performance of poly[3-(4-n-octyl)-phenylthiophene] (POPT) and poly(3hexylthiophene) (P3HT) are compared in devices using 4,7-bis(2-(l-(2-ethylhexyl)-4,5-dicyanoimidazol-2-yl)vinyi)benzo[c][l,2,5] -thiadiazole (EV-BT) as the electron acceptor. Despite their reduced light absorption, POPT:EV-BT devices generate higher photocurrents in both bilayer and bulk heterojunction (BHJ) architectures than analogous P3HT:EV-BT devices. Optimized POPT:EV-BT BHJ devices achieve 1.4% average efficiency, whereas the analogous P3HT devices only reach 1.1%. Morphology does not account for the large difference in performance as AFM studies of the active layer suggest, comparable levels of phase separation in the two systems. Reverse bias analysis demonstrates that P3HT devices have a higher maximum potential than POPT devices, but P3HT devices appear to be more severely limited by recombination losses under standard operating conditions. A possible explanation for the superior performance in POPT devices is that the pendant phenyl ring in POPT can twist out-of-plane and increase the separation distance with the acceptor molecule. A larger donor/acceptor separation distance can destabilize the geminate pair and lead to more efficient charge separation in POPT:EV-BT devices. Our results emphasize the importance of donor/acceptor pair interactions and its effect on charge separation, processes in polymer solar cells. © 2010 American Chemical Society.

  9. Electroluminescence of a polythiophene molecular wire suspended between a metallic surface and the tip of a scanning tunneling microscope.

    Science.gov (United States)

    Reecht, Gaël; Scheurer, Fabrice; Speisser, Virginie; Dappe, Yannick J; Mathevet, Fabrice; Schull, Guillaume

    2014-01-31

    The electroluminescence of a polythiophene wire suspended between a metallic surface and the tip of a scanning tunneling microscope is reported. Under positive sample voltage, the spectral and voltage dependencies of the emitted light are consistent with the fluorescence of the wire junction mediated by localized plasmons. This emission is strongly attenuated for the opposite polarity. Both emission mechanism and polarity dependence are similar to what occurs in organic light emitting diodes (OLED) but at the level of a single molecular wire.

  10. Ab-initio calculation of quasi-particle bandstructure, exciton binding energies and dielectric properties of polythiophene

    NARCIS (Netherlands)

    van der Horst, J.W.; Bobbert, P.A.; Bobbert, Peter A.; Michels, M.A.J.; Brocks, G.; Kelly, Paul J.

    1999-01-01

    We use the ab-initio many-body GW method to calculate the quasi-particle spectrum of polythiophene. For the isolated chain, we find a large increase of the gap compared to DFT-LDA calculations (1.2 eV). The result (4.1 eV) exceeds experimental values, due to the absence of long-range screening in

  11. Comparative study: The effects of solvent on the morphology, optical and structural features of regioregular poly(3-hexylthiophene):fullerene thin films

    CSIR Research Space (South Africa)

    Motaung, DE

    2010-01-01

    Full Text Available preparation Sample preparations were done according to the following procedure. All chemicals used in this experiment were purchased from Sigma Aldrich. Regioregular poly (3-hexylthiophene) (rr-P3HT) was used as a light absorption and electron... the percentage of stereo-regular head-to-tail (HT) attachments of the hexyl side chains to the 4 3-position of the thiophene rings [17]. These materials were used as received, without any further purification. Indium tin oxide (ITO) coated on a 1 mm glass...

  12. Self-assembly of regioregular poly (3,3‴-didodecylquarterthiophene) in chloroform and study of its junction properties

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Manish Kumar; Kumar, Ashish; Prakash, Rajiv, E-mail: rprakash.mst@iitbhu.ac.in

    2017-03-15

    Graphical abstract: rr-PQT-12 films formed by spin coating before and after ageing (at 25 °C) showing the effect of fiber growth and significant change in charge transfer property. - Highlights: • Self-assembly of rr-PQT-12 into fiber form in chloroform marginal solvent at RT. • As assembled dispersion is processed for the fabrication of organic devices. • Processed fiber shows improvement in charge transport over its pristine one. - Abstract: This article deals with the study of self-assembly of regioregular poly (3,3‴-didodecylquarterthiophene), rr-PQT-12 into fiber form in chloroform by ageing process. Time dependent fiber growth mechanism is monitored by UV–vis absorption and confirmed by atomic force microscopy technique. It is observed that isolated rr-PQT-12 undergoes self-assembled fibril growth along π-π interaction direction and 45 min is sufficient for such assemblies in case of 0.125% w/v of rr-PQT-12 polymer in chloroform. Further the self-assembled fibril polymer is used in fabrication of Schottky diode. It exhibits ten times enhancement in forward current density (with one-fold higher mobility) and high rectification ratio compared to the isolated rr-PQT-12 due to the segmental electronic traps filling within stacking region. Our study provides a facile method of ordering of PQT-12 isolated chains in chloroform solvent and an effective way for improvement of performance of organic polymers based devices through such self-assembly.

  13. Organic Photovoltaic Devices Based on Oriented n-Type Molecular Films Deposited on Oriented Polythiophene Films.

    Science.gov (United States)

    Mizokuro, Toshiko; Tanigaki, Nobutaka; Miyadera, Tetsuhiko; Shibata, Yousei; Koganezawa, Tomoyuki

    2018-04-01

    The molecular orientation of π-conjugated molecules has been reported to significantly affect the performance of organic photovoltaic devices (OPVs) based on molecular films. Hence, the control of molecular orientation is a key issue toward the improvement of OPV performance. In this research, oriented thin films of an n-type molecule, 3,4,9,10-Perylenetetracarboxylic Bisbenzimida-zole (PTCBI), were formed by deposition on in-plane oriented polythiophene (PT) films. Orientation of the PTCBI films was evaluated by polarized UV-vis spectroscopy and 2D-Grazing incidence X-ray diffraction. Results indicated that PTCBI molecules on PT film exhibit nearly edge-on and in-plane orientation (with molecular long axis along the substrate), whereas PTCBI molecules without PT film exhibit neither. OPVs composed of PTCBI molecular film with and without PT were fabricated and evaluated for correlation of orientation with performance. The OPVs composed of PTCBI film with PT showed higher power conversion efficiency (PCE) than that of film without PT. The experiment indicated that in-plane orientation of PTCBI molecules absorbs incident light more efficiently, leading to increase in PCE.

  14. Cost–effective Polythiophene Counter Electrodes for Dye Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Tolu Merve Celik

    2016-01-01

    Full Text Available Dye sensitized solar cells (DSSCs are most promising devices among third–generation solar cells because of low cost, easy production, environmental friendliness, and relatively high conversion efficiency. Counter electrode (CE, which is an important component in DSSCs, functions as an electron transfer agent as well as the regenerator of redox couple. Hitherto, various methods and materials were used to prepare different counter electrodes.Among these materials, conducting polymers have been widely investigated and employed in various applications such as sensors, supercapacitors, energy storage devices, DSSCs and others. In this study, Polythiophene (PTh conducting polymer was successfully synthesized by electrochemical deposition method, and employed as an alternative to expensive platinum (Pt CE for DSSC. Besides, PTh conducting polymer was electrochemically deposited via cyclic voltammetry method on FTO substrates. The morphology of the PTh film was characterized by SEM and AFM. Finally, the photovoltaic performance of PTh CE based DSSC was compared with PEDOT CE based device. This new concept—along with promising electrocatalytic activity and facile electron transfer—provides a new approach to enhance the photovoltaic performances of Pt–free DSSCs.

  15. Synthesis and Characterization of Novel Polythiophenes Containing Pyrene Chromophores: Thermal, Optical and Electrochemical Properties

    Directory of Open Access Journals (Sweden)

    Bianca X. Valderrama-García

    2016-01-01

    Full Text Available A novel series of pyrene containing thiophene monomers TPM1–5 were synthesized and fully characterized by FTIR, MS, 1H- and 13C-NMR spectroscopy; their thermal properties were determined by TGA and DSC. These monomers were chemically polymerized using FeCl3 as oxidizing agent to give the corresponding oligomers TPO1–5 and they were electrochemically polymerized to obtain the corresponding polymer films deposited onto ITO. All oligomers exhibited good thermal stability, with T10 values between 255 and 299 °C, and Tg values varying from 36 to 39 °C. The monomers showed an absorption band at 345 nm due to the S0 → S2 transition of the pyrene group, whereas the fluorescence spectra showed a broad emission band arising from the “monomer” emission at 375–420 nm. The obtained polymers exhibited two absorption bands at 244 and 354 nm, due to the polythiophene and the pyrene moieties, respectively. The fluorescence spectra of polymers showed a broad “monomer” emission at 380–420 nm followed by an intense excimer emission band at 570 nm, due to the presence of intramolecular pyrene-pyrene interactions in these compounds.

  16. A novel polythiophene – ionic liquid modified clay composite solid phase microextraction fiber: Preparation, characterization and application to pesticide analysis

    International Nuclear Information System (INIS)

    Pelit, Füsun Okçu; Pelit, Levent; Dizdaş, Tuğberk Nail; Aftafa, Can; Ertaş, Hasan; Yalçınkaya, E.E.; Türkmen, Hayati; Ertaş, F.N.

    2015-01-01

    Highlights: • A novel polythiophene – ionic liquid modified clay surface has been prepared. • Polymerization was performed electrochemically on a stainless steel wire. • This material was used as a SPME fiber in head space mode. • This new SPME fiber was applied for analysis of pesticides in juice samples. • Fiber adsorption properties were improved by modification of ionic liquids. - Abstract: This report comprises the novel usage of polythiophene – ionic liquid modified clay surfaces for solid phase microextraction (SPME) fiber production to improve the analysis of pesticides in fruit juice samples. Montmorillonite (Mmt) clay intercalated with ionic liquids (IL) was co-deposited with polythiophene (PTh) polymer coated electrochemically on an SPME fiber. The surface of the fibers were characterized by using scanning electron microscopy (SEM). Operational parameters effecting the extraction efficiency namely; the sample volume and pH, adsorption temperature and time, desorption temperature and time, stirring rate and salt amount were optimized. In order to reveal the major effects, these eight factors were selected and Plackett–Burman Design was constructed. The significant parameters detected; adsorption and temperature along with the stirring rate, were further investigated by Box–Behnken design. Under optimized conditions, calibration graphs were plotted and detection limits were calculated in the range of 0.002–0.667 ng mL −1 . Relative standard deviations were no higher than 18%. Overall results have indicated that this novel PTh-IL-Mmt SPME surface developed by the aid of electrochemical deposition could offer a selective and sensitive head space analysis for the selected pesticide residues

  17. A novel polythiophene – ionic liquid modified clay composite solid phase microextraction fiber: Preparation, characterization and application to pesticide analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pelit, Füsun Okçu, E-mail: fusun.okcu@ege.edu.tr; Pelit, Levent; Dizdaş, Tuğberk Nail; Aftafa, Can; Ertaş, Hasan; Yalçınkaya, E.E.; Türkmen, Hayati; Ertaş, F.N.

    2015-02-15

    Highlights: • A novel polythiophene – ionic liquid modified clay surface has been prepared. • Polymerization was performed electrochemically on a stainless steel wire. • This material was used as a SPME fiber in head space mode. • This new SPME fiber was applied for analysis of pesticides in juice samples. • Fiber adsorption properties were improved by modification of ionic liquids. - Abstract: This report comprises the novel usage of polythiophene – ionic liquid modified clay surfaces for solid phase microextraction (SPME) fiber production to improve the analysis of pesticides in fruit juice samples. Montmorillonite (Mmt) clay intercalated with ionic liquids (IL) was co-deposited with polythiophene (PTh) polymer coated electrochemically on an SPME fiber. The surface of the fibers were characterized by using scanning electron microscopy (SEM). Operational parameters effecting the extraction efficiency namely; the sample volume and pH, adsorption temperature and time, desorption temperature and time, stirring rate and salt amount were optimized. In order to reveal the major effects, these eight factors were selected and Plackett–Burman Design was constructed. The significant parameters detected; adsorption and temperature along with the stirring rate, were further investigated by Box–Behnken design. Under optimized conditions, calibration graphs were plotted and detection limits were calculated in the range of 0.002–0.667 ng mL{sup −1}. Relative standard deviations were no higher than 18%. Overall results have indicated that this novel PTh-IL-Mmt SPME surface developed by the aid of electrochemical deposition could offer a selective and sensitive head space analysis for the selected pesticide residues.

  18. Direct observation of backbone planarization via side-chain alignment in single bulky-substituted polythiophenes

    Science.gov (United States)

    Raithel, Dominic; Simine, Lena; Pickel, Sebastian; Schötz, Konstantin; Panzer, Fabian; Baderschneider, Sebastian; Schiefer, Daniel; Lohwasser, Ruth; Köhler, Jürgen; Thelakkat, Mukundan; Sommer, Michael; Köhler, Anna; Rossky, Peter J.; Hildner, Richard

    2018-03-01

    The backbone conformation of conjugated polymers affects, to a large extent, their optical and electronic properties. The usually flexible substituents provide solubility and influence the packing behavior of conjugated polymers in films or in bad solvents. However, the role of the side chains in determining and potentially controlling the backbone conformation, and thus the optical and electronic properties on the single polymer level, is currently under debate. Here, we investigate directly the impact of the side chains by studying the bulky-substituted poly(3-(2,5-dioctylphenyl)thiophene) (PDOPT) and the common poly(3-hexylthiophene) (P3HT), both with a defined molecular weight and high regioregularity, using low-temperature single-chain photoluminescence (PL) spectroscopy and quantum-classical simulations. Surprisingly, the optical transition energy of PDOPT is significantly (˜2,000 cm‑1 or 0.25 eV) red-shifted relative to P3HT despite a higher static and dynamic disorder in the former. We ascribe this red shift to a side-chain induced backbone planarization in PDOPT, supported by temperature-dependent ensemble PL spectroscopy. Our atomistic simulations reveal that the bulkier 2,5-dioctylphenyl side chains of PDOPT adopt a clear secondary helical structural motif and thus protect conjugation, i.e., enforce backbone planarity, whereas, for P3HT, this is not the case. These different degrees of planarity in both thiophenes do not result in different conjugation lengths, which we found to be similar. It is rather the stronger electronic coupling between the repeating units in the more planar PDOPT which gives rise to the observed spectral red shift as well as to a reduced calculated electron‑hole polarization.

  19. Raman imaging of carrier distribution in the channel of an ionic liquid-gated transistor fabricated with regioregular poly(3-hexylthiophene)

    Science.gov (United States)

    Wada, Y.; Enokida, I.; Yamamoto, J.; Furukawa, Y.

    2018-05-01

    Raman images of carriers (positive polarons) at the channel of an ionic liquid-gated transistor (ILGT) fabricated with regioregular poly(3-hexylthiophene) (P3HT) have been measured with excitation at 785 nm. The observed spectra indicate that carriers generated are positive polarons. The intensities of the 1415 cm-1 band attributed to polarons in the P3HT channel were plotted as Raman images; they showed the carrier density distribution. When the source-drain voltage VD is lower than the source-gate voltage VG (linear region), the carrier density was uniform. When VD is nearly equal to VG (saturation region), a negative carrier density gradient from the source electrode towards the drain electrode was observed. This carrier density distribution is associated with the observed current-voltage characteristics, which is not consistent with the "pinch-off" theory of inorganic semiconductor transistors.

  20. Preparation and characterization of porphyrin-polythiophene stacked films as prepared by electrochemical method under stirring condition

    International Nuclear Information System (INIS)

    Sugawa, Kosuke; Akiyama, Tsuyoshi; Yamada, Sunao

    2008-01-01

    Porphyrin-polythiophene (pTh) stacked films consisting of meso-tetrathienylporphyrin (TThP) and bithiophene (BiTh) were prepared on transparent indium-tin-oxide (ITO) electrodes by sequential electrochemical scanning of applied potential between 0 and + 2 V vs Ag wire in the electrolyte solution of BiTh and TThP under stirring condition. First, the pTh films were prepared by electrochemical polymerization and then TThP was incorporated into the as-prepared pTh film by subsequent electrochemical scanning as described above in the TThP solution. The operation of solution stirring during electrochemical scanning achieved the formation of robust stacked films. UV/Vis and fluorescence spectra confirmed that the amount of TThP moiety increased with increasing the number of electrochemical scanning cycles in the TThP solution. In order to evaluate the incorporation profile of TThP, surface analyses and depth profiles of stacked films were carried out by XPS spectroscopy. The results suggested that all films formed porphyrin-polythiophene stacked structure precisely, and that TThP was exclusively incorporated around the outermost region of the pTh film

  1. A molecular dynamic simulation study of mechanical properties of graphene–polythiophene composite with Reax force field

    International Nuclear Information System (INIS)

    Nayebi, Payman; Zaminpayma, Esmaeil

    2016-01-01

    In this paper, we performed molecular dynamic simulations by Reax force field to study the mechanical properties of graphene–polythiophene nanocomposite. By computing elastic constant, breaking stress, breaking strain and Young's modulus from the stress–strain curve for the nanocomposites, we investigated effects of tension orientation, graphene loading to the polymer, temperature of nanocomposite and defect of graphene on these mechanical characters. It is found that mechanical characters of tension along the zigzag orientation are higher than other directions. Also, by increasing the weight concentration of graphene in composite, the Young's modulus and breaking strain increase. Our results showed that the Young's modulus decreased with increasing temperature. Finally by applying defect on graphene structure, we found that one atom missing defect has lower Young's modulus. Also, by increasing the defects concentration, elastic modulus decreases gradually. - Highlights: • We studied mechanical properties of graphene–polythiophene nanocomposite. • Mechanical characters of tension along the zigzag are higher than other directions. • By increasing the weight concentration of graphene in composite, the Young's modulus increases. • Young's modulus decreased with increasing temperature. • By increasing the defects concentration, elastic modulus decreases gradually.

  2. Printed biotin-functionalised polythiophene films as biorecognition layers in the development of paper-based biosensors

    Science.gov (United States)

    Ihalainen, Petri; Pesonen, Markus; Sund, Pernilla; Viitala, Tapani; Määttänen, Anni; Sarfraz, Jawad; Wilén, Carl-Erik; Österbacka, Ronald; Peltonen, Jouko

    2016-02-01

    The integration of flexible electronic sensors in clinical diagnostics is visioned to significantly reduce the cost of many diagnostic tests and ultimately make healthcare more accessible. This study concentrates on the characterisation of inkjet-printed bio-functionalised polythiophene films on paper-based ultrathin gold film (UTGF) electrodes and their possible application as biorecognition layers. Physicochemical surface properties (topography, chemistry, and wetting) and electrochemical characteristics of water-soluble regioirregular tetraethylene-glycol polythiophene (TEGPT) and biotin-functionalised TEGPT (b-TEGPT) films were examined and compared. In addition, their specificity towards streptavidin protein was tested. The results show that stable supramolecular biorecognition layers of insulating b-TEGPT and streptavidin were successfully fabricated on a paper-based UTGF by inkjet-printing. Good adhesion of thiophene to UTGF can be attributed to covalent linkage between sulphur and gold, whereas the stability of the streptavidin layer is due to the high affinity between biotin and streptavidin. The device introduced can be utilised in the development of biosensors for clinically relevant analytes e.g. for detecting complementary DNA oligomers or antibody-antigen complexes.

  3. Incorporation of fused tetrathiafulvalenes (TTFs) into polythiophene architectures: varying the electroactive dominance of the TTF species in hybrid systems.

    Science.gov (United States)

    Berridge, Rory; Skabara, Peter J; Pozo-Gonzalo, Cristina; Kanibolotsky, Alexander; Lohr, Jan; McDouall, Joseph J W; McInnes, Eric J L; Wolowska, Joanna; Winder, Christoph; Sariciftci, N Serdar; Harrington, Ross W; Clegg, William

    2006-02-23

    A novel polythienylenevinylene (PTV) and two new polythiophenes (PTs), featuring fused tetrathiafulvalene (TTF) units, have been prepared and characterized by ultraviolet-visible (UV-vis) and electron paramagnetic resonance (EPR) spectroelectrochemistry. All polymers undergo two sequential, reversible oxidation processes in solution. Structures in which the TTF species is directly linked to the polymer backbone (2 and 4) display redox behavior which is dictated by the fulvalene system. Once the TTF is spatially removed from the polymer chain by a nonconjugated link (polymer 3), the electroactivity of both TTF and polythiophene moieties can be detected. Computational studies confirm the delocalization of charge over both electroactive centers (TTF and PT) and the existence of a triplet dication intermediate. PTV 4 has a low band gap (1.44 eV), is soluble in common organic solvents, and is stable under ambient conditions. Organic solar cells of polymer 4:[6,6]-phenyl-C(61) butyric acid methyl ester (PCBM) have been fabricated. Under illumination, a photovoltaic effect is observed with a power conversion efficiency of 0.13% under AM1.5 solar simulated light. The onset of photocurrent at 850 nm is consistent with the onset of the pi-pi absorption band of the polymer. Remarkably, UV-vis spectroelectrochemistry of polymer 4 reveals that the conjugated polymer chain remains unchanged during the oxidation of the polymer.

  4. Immunodetection of salivary biomarkers by an optical microfluidic biosensor with polyethylenimine-modified polythiophene-C70 organic photodetectors.

    Science.gov (United States)

    Dong, Tao; Pires, Nuno Miguel Matos

    2017-08-15

    This work reports a novel optical microfluidic biosensor with highly sensitive organic photodetectors (OPDs) for absorbance-based detection of salivary protein biomarkers at the point of care. The compact and miniaturized biosensor has comprised OPDs made of polythiophene-C 70 bulk heterojunction for the photoactive layer; whilst a calcium-free cathode interfacial layer, made of linear polyethylenimine, was incorporated to the photodetectors to enhance the low cost. The OPDs realized onto a glass chip were aligned to antibody-functionalized chambers of a poly(methyl methacrylate) microfluidic chip, in where immunogold-silver assays were conducted. The biosensor has detected IL-8, IL-1β and MMP-8 protein in spiked saliva with high detection specificity and short analysis time exhibiting detection limits between 80pgmL -1 and 120pgmL -1 . The result for IL-8 was below the clinical established cut-off of 600pgmL -1 , which revealed the potential of the biosensor to early detection of oral cancer. The detection limit was also comparable to other previously reported immunosensors performed with bulky instrumentation or using inorganic photodetectors. The optical detection sensitivity of the polythiophene-C 70 OPD was enhanced by optimizing the thickness of the photoactive layer and anode interfacial layer prior to the saliva immunoassays. Further, the biosensor was tested with unspiked human saliva samples, and the results of measuring IL-8 and IL-1β were in statistical agreement with those provided by two commercial assays of ELISA. The optical microfluidic biosensor reported hereby offers an attractive and cost-effective tool to diagnostics or screening purposes at the point of care. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Hybrid TiO2 Solar Cells Produced from Aerosolized Nanoparticles of Water-Soluble Polythiophene Electron Donor Layer

    Directory of Open Access Journals (Sweden)

    Marshall L. Sweet

    2014-01-01

    Full Text Available Hybrid solar cells (HSCs with water soluble polythiophene sodium poly[2-(3-thienyl-ethyloxy-4-butylsulfonate] (PTEBS thin films produced using electrospray deposition (ESD were fabricated, tested, and modeled and compared to devices produced using conventional spin coating. A single device structure of FTO/TiO2/PTEBS/Au was used to study the effects of ESD of the PTEBS layer on device performance. ESD was found to increase the short circuit current density (Jsc by a factor of 2 while decreasing the open circuit voltage (Voc by half compared to spin coated PTEBS films. Comparable efficiencies of 0.009% were achieved from both device construction types. Current-voltage curves were modeled using the characteristic solar cell equation and showed a similar increase in generated photocurrent with an increase by two orders of magnitude in the saturation current in devices from ESD films. Increases in Jsc are attributed to an increase in the interfacial contact area between the TiO2 and PTEBS layers, while decreases in Voc are attributed to incomplete film formation from ESD.

  6. Potentiometric and Conductometric Study of Aqueous Solutions of Lithium and Sodium Salts of Poly(thiophen-3-ylacetic acid).

    Science.gov (United States)

    Hostnik, Gregor; Vlachy, Vojko; Bondarev, Dmitrij; Jiří, Vohlídal; Cerar, Janez

    2012-09-01

    The title polymer, PTAA, practically free of ester groups was obtained by oxidative polymerization of methyl thiophen-3-ylacetate and subsequent basic hydrolysis of primary polymer. Poly(thiophen-3-ylacetic acid) has been thoroughly characterized by NMR, IR, Raman, and UV/Vis spectroscopy. The polyacid behavior during neutralization titrations with lithium and sodium hydroxides, carried out under nitrogen atmosphere, has been studied by conductometry and potentiometry. Henderson-Hasselbach plots of potentiometric titration curves show a break point at pH around 6, where the curve slope drops from 1.8 (at lower pH) to a value from 1.05 to 1.3 (at higher pH values). The UV/Vis spectra monitored during back titration show: (i) monotonous decrease of both λmax and εmax as pH decreases, (ii) the presence of the isosbestic point at 401 nm that can be ascribed to conformational transition of PTAA chains, and (iii) absence of the isosbestic point at 392 nm reported previously by other authors.

  7. Stable inverted polymer/fullerene solar cells using a cationic polythiophene modified PEDOT:PSS cathodic interface

    Energy Technology Data Exchange (ETDEWEB)

    Rider, David A.; Worfolk, Brian J.; Buriak, Jillian M. [Department of Chemistry, University of Alberta, Edmonton, Alberta (Canada); NRC National Institute for Nanotechnology, Edmonton, Alberta (Canada); Harris, Kenneth D.; Shahbazi, Kevin; Fleischauer, Michael D. [NRC National Institute for Nanotechnology, Edmonton, Alberta (Canada); Lalany, Abeed [Department of Electrical and Computer Engineering, University of Alberta, Edmonton (Canada); Brett, Michael J. [NRC National Institute for Nanotechnology, Edmonton, Alberta (Canada); Department of Electrical and Computer Engineering, University of Alberta, Edmonton (Canada)

    2010-08-09

    A cationic and water-soluble polythiophene [poly[3-(6-pyridiniumylhexyl)thiophene bromide](P3PHT{sup +}Br{sup -})] is synthesized and used in combination with anionic poly(3,4-ethylenedioxythiophene):poly(p-styrenesulfonate) (PEDOT:PSS){sup -} to produce hybrid coatings on indium tin oxide (ITO). Two coating strategies are established: i) electrostatic layer-by-layer assembly with colloidal suspensions of (PEDOT:PSS){sup -}, and ii) modification of an electrochemically prepared (PEDOT:PSS){sup -} film on ITO. The coatings are found to modify the work function of ITO such that it could act as a cathode in inverted 2,5-diyl-poly(3-hexylthiophene) (P3HT)/[6,6]-phenyl-C{sub 61}-butyric acid methyl ester (PCBM) polymer photovoltaic cells. The interfacial modifier created from the layer-by-layer assembly route is used to produce efficient inverted organic photovoltaic devices (power conversion efficiency {proportional_to}2%) with significant long-term stability in excess of 500 h. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  8. Vapor-phase deposition of regioregular and oriented poly(3-hexylthiophene) structures and novel nanostructured composites of interpenetrating poly(3-hexylthiophene) and polyaniline exhibiting full-color wavelength (400-1000 nm) photoluminescence

    Science.gov (United States)

    Biswas, A.; Bayer, I. S.; Karulkar, P. C.; Tripathi, A.; Avasthi, D. K.

    2007-10-01

    A promising solvent-free technique of electron-beam-assisted vapor-phase codeposition method is presented which allows uniform blending of different conjugated and nonconjugated polymers at the nanoscale. The technique allows direct incorporation of regioregular poly(3-hexylthiophene) (P3HT) polymer with different structural orientations into conventional and semiconducting polymers without fractionation or degradation of P3HT while maintaining the nanoscale morphology of deposited organic films. The results of fabricated novel nanostructured organic composites (˜100-200nm) comprising regioregular and oriented P3HT and different conjugated and nonconjugated polymers including selective assembly of P3HT nanonodules into a copolymer template are presented. We show a typical example of blending of P3HT and polyaniline (PANI) that formed a unique nanoscale morphology comprising interpenetrating networks of different shapes and sizes of nanospherulites (˜100nm) of P3HT in PANI. The so fabricated nanocomposites (˜200nm) exhibited remarkable broadband photoluminescence features covering the entire blue, green, and red wavelength regions between 400 and 1000nm. Such organic nanocomposites might be useful for flexible full-color screen flat panel displays and organic white-light solid-state lighting applications.

  9. Effects of single-walled carbon nanotubes on the optical and photo-conductive properties of their composite films with regio-regular poly(3-hexylthiophene)

    International Nuclear Information System (INIS)

    Bakour, Anass; Geschier, Frédéric; Baitoul, Mimouna; Mbarek, Mohamed; El-Hadj, Karim; Duvail, Jean-Luc; Lefrant, Serge; Faulques, Eric; Massuyeau, Florian; Wery-Venturini, Jany

    2014-01-01

    The effect of a small admixture of single-walled carbon nanotubes (SWNTs) HiPCO (high pressure carbon monoxide) (from 0.5 to 2 wt%) on the supramolecular structure in regio-regular poly(3-hexylthiophene) (RR-P3HT) thin films is studied and their optical and photoconductivity properties are investigated. It is demonstrated that the presence of such small amounts of nanotubes improves the structural organization in the films as evidenced by X-ray diffraction (XRD) studies. This is confirmed by UV–visible optical absorption investigations which clearly show a better conjugation of P3HT in the presence of nanotubes. In Raman spectra of composites, changes in intensities and frequencies of the radial breathing modes are observed upon addition of nanotubes. This can be rationalized by a modification of the resonance conditions caused by a selective dispersion and wrapping of SWNTs via π-interaction (π-stacking). As a consequence of these interactions, a dramatic photoluminescence (PL) quenching is observed which becomes more and more pronounced with increasing the nanotube content. This implies a fast photo-induced electron transfer favoured by a large area of the SWNTs/P3HT interface and strong interactions between these two components. An increase in the composite photocurrent by at least one-order of magnitude, as compared to the case of pure P3HT film, is the most pronounced effect of this electron transfer. These two effects are of crucial importance for the application of the investigated composites in bulk hetero-junction photovoltaic cells (BHJPCs) and organic photo-detectors (OPDs). - Highlights: • Optical properties of single-walled carbon nanotubes/P3HT films are investigated. • The insertion of SWNTs leads to an improvement of structural organization. • Composite films shows photoluminescence quenching at low SWNTs concentration. • Existence of a fast photo-induced electron transfer between SWNTs and P3HT. • These two effects are of crucial

  10. Effects of single-walled carbon nanotubes on the optical and photo-conductive properties of their composite films with regio-regular poly(3-hexylthiophene)

    Energy Technology Data Exchange (ETDEWEB)

    Bakour, Anass [University Sidi Mohammed Ben Abdellah, Faculty of Sciences, Dhar El Mahraz, Laboratory of Solid State Physics, Group Polymers and Nanomaterials, PO Box 1796, Atlas, Fes 30000 (Morocco); Geschier, Frédéric [Institut des Matériaux Jean Rouxel, Université de Nantes, CNRS, UMR 6502, 2 rue de la Houssinière, PO Box 3229, 44322 Nantes cedex (France); Baitoul, Mimouna, E-mail: baitoul@yahoo.fr [University Sidi Mohammed Ben Abdellah, Faculty of Sciences, Dhar El Mahraz, Laboratory of Solid State Physics, Group Polymers and Nanomaterials, PO Box 1796, Atlas, Fes 30000 (Morocco); Mbarek, Mohamed [Institut des Matériaux Jean Rouxel, Université de Nantes, CNRS, UMR 6502, 2 rue de la Houssinière, PO Box 3229, 44322 Nantes cedex (France); Unité de Recherche, Matériaux Nouveaux et Dispositifs Electroniques Organiques, Faculté des Sciences, Université de Monastir, 5000 Monastir (Tunisia); El-Hadj, Karim; Duvail, Jean-Luc; Lefrant, Serge; Faulques, Eric; Massuyeau, Florian; Wery-Venturini, Jany [Institut des Matériaux Jean Rouxel, Université de Nantes, CNRS, UMR 6502, 2 rue de la Houssinière, PO Box 3229, 44322 Nantes cedex (France)

    2014-02-14

    The effect of a small admixture of single-walled carbon nanotubes (SWNTs) HiPCO (high pressure carbon monoxide) (from 0.5 to 2 wt%) on the supramolecular structure in regio-regular poly(3-hexylthiophene) (RR-P3HT) thin films is studied and their optical and photoconductivity properties are investigated. It is demonstrated that the presence of such small amounts of nanotubes improves the structural organization in the films as evidenced by X-ray diffraction (XRD) studies. This is confirmed by UV–visible optical absorption investigations which clearly show a better conjugation of P3HT in the presence of nanotubes. In Raman spectra of composites, changes in intensities and frequencies of the radial breathing modes are observed upon addition of nanotubes. This can be rationalized by a modification of the resonance conditions caused by a selective dispersion and wrapping of SWNTs via π-interaction (π-stacking). As a consequence of these interactions, a dramatic photoluminescence (PL) quenching is observed which becomes more and more pronounced with increasing the nanotube content. This implies a fast photo-induced electron transfer favoured by a large area of the SWNTs/P3HT interface and strong interactions between these two components. An increase in the composite photocurrent by at least one-order of magnitude, as compared to the case of pure P3HT film, is the most pronounced effect of this electron transfer. These two effects are of crucial importance for the application of the investigated composites in bulk hetero-junction photovoltaic cells (BHJPCs) and organic photo-detectors (OPDs). - Highlights: • Optical properties of single-walled carbon nanotubes/P3HT films are investigated. • The insertion of SWNTs leads to an improvement of structural organization. • Composite films shows photoluminescence quenching at low SWNTs concentration. • Existence of a fast photo-induced electron transfer between SWNTs and P3HT. • These two effects are of crucial

  11. Polythiophene thin films electrochemically deposited on sol-gel based TiO2 for photovoltaic applications

    International Nuclear Information System (INIS)

    Valaski, R.; Yamamoto, N.A.D.; Canestraro, C.D.; Micaroni, L.; Mello, R.M.Q.; Quirino, W.G.; Legani, C.; Achete, C.A.; Roman, L.S.; Cremona, M.

    2010-01-01

    In this work, the influence of titanium dioxide (TiO 2 ) thin films on the efficiency of organic photovoltaic devices based on electrochemically synthesized polythiophene (PT) was investigated. TiO 2 films were produced by sol-gel methods with controlled thickness. The best TiO 2 annealing condition was determined through the investigation of the temperature influence on the electron charge mobility and resistivity in a range between 723 K and 923 K. The PT films were produced by chronoamperometric method in a 3-electrode cell under a controlled atmosphere. High quality PT films were produced onto 40 nm thick TiO 2 layer previously deposited onto fluorine doped tin oxide (FTO) substrate. The morphology of PT films grown on both substrates and its strong influence on the device performance and PT minimum thickness were also investigated. The maximum external quantum efficiency (IPCE) reached was 9% under monochromatic irradiation (λ = 610 nm; 1 W/m 2 ) that is three orders of magnitude higher than that presented by PT-homolayer devices with similar PT thickness. In addition, the open-circuit voltage (V oc ) was about 700 mV and the short-circuit current density (J sc ) was 0.03 A/m 2 (λ = 610 nm; 7 W/m 2 ). However, as for the PT-homolayer also the TiO 2 /PT based devices are characterized by antibatic response when illuminated through FTO. Finally, the Fill Factor (FF) of these devices is low (25%), indicating that the series resistance (R s ), which is strongly dependent of the PT thickness, is too large. This large R s value is compensated by TiO 2 /PT interface morphology and by FTO/TiO 2 and TiO 2 /PT interface phenomena producing preferential paths in which the internal electrical field is higher, improving the device efficiency.

  12. Ethylene glycol oxidation on Pt and Pt-Ru nanoparticle decorated polythiophene/multiwalled carbon nanotube composites for fuel cell applications

    International Nuclear Information System (INIS)

    Selvaraj, Vaithilingam; Alagar, Muthukaruppan

    2008-01-01

    A novel supporting material containing polythiophene (PTh) and multiwalled carbon nanotubes (MWCNTs) (PTh-CNTs) is prepared by in situ polymerization of thiophene on carbon nanotubes using FeCl 3 as oxidizing agent under sonication. The prepared polythiophene/CNT composites are further decorated with Pt and Pt-Ru nanoparticles by chemical reduction of the corresponding metal salts using HCHO as reducing agent at pH = 11 (Pt/PTh-CNT and Pt-Ru/PTh-CNT). The fabricated composite films decorated with nanoparticles were investigated towards the electrochemical oxidation of ethylene glycol (EG). The presence of carbon nanotubes in conjugation with a conducting polymer produces a good catalytic effect, which might be due to the higher electrochemically accessible surface areas, electronic conductivity and easier charge-transfer at polymer/electrolyte interfaces, which allows higher dispersion of Pt and Pt-Ru nanoparticles. Such nanoparticle modified PTh-CNT electrodes exhibit better catalytic behavior towards ethylene glycol oxidation. Results show that Pt/PTh-CNT and Pt-Ru/PTh-CNT modified electrodes show enhanced electrocatalytic activity and stability towards the electro-oxidation of ethylene glycol than the Pt/PTh electrodes, which shows that the composite film is more promising for applications in fuel cells

  13. Functional polythiophene nanoparticles: Size-controlled electropolymerization and ion selective response

    DEFF Research Database (Denmark)

    Si, P.C.; Chi, Qijin; Li, Z.S.

    2007-01-01

    polymerization to form polymer nanoparticles or clusters by which the size of the polymer nanoparticles can further be controlled electrochemically. The electropolymerization was monitored in situ by scanning tunneling microscopy to unravel the dynamics of the process and possible mechanisms. These are further......We have synthesized a thiophene derivative, (4-benzeno-15-crown-5 ether)-thiophene-3-methylene-amine (BTA), which was used as a monomer for electrochemical polymerization on metallic surfaces to prepare functional polymer films. Self-assembly of BTA monomers on Au(111) surfaces promotes ordered...

  14. Generation of native polythiophene/PCBM composite nanoparticles via the combination of ultrasonic micronization of droplets and thermocleaving from aqueous dispersion

    DEFF Research Database (Denmark)

    Nan, Yaxiong; Hu, Xiaolian; Larsen-Olsen, Thue Trofod

    2011-01-01

    -PT/PCBM nanoparticles were determined by atomic force microscopy (AFM), small-angle x-ray scattering (SAXS) and grazing incidence SAXS (GISAXS), giving an average size of ~ 140 nm. The GISAXS results reveal that n-PT/PCBM nanoparticles pack in an ordered structure as opposed to the P3MHOCT/PCBM nanoparticles......We report the preparation of native polythiophene (n-PT)/[6, 6]-phenyl-C61-butyric acid methyl ester (PCBM) composite nanoparticles from a poly[3-(2-methylhex-2-yl)oxy-carbonyldithiophene] (P3MHOCT)/PCBM aqueous dispersion prepared from an ultrasonically generated emulsion. The subsequent steps....... The successful vapour-phase preparation of phase-separated n-PT/PCBM nanoparticles provides a new route to all-aqueous processing of conjugated materials relevant to efficient polymer solar cells with long operational stability. The use of ultrasound was involved in both liquid and gas phases demonstrating...

  15. Quasi Solid-State Dye-Sensitized Solar Cell Incorporating Highly Conducting Polythiophene-Coated Carbon Nanotube Composites in Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Mohammad Rezaul Karim

    2011-01-01

    Full Text Available Conducting polythiophene (PTh composites with the host filler multiwalled carbon nanotube (MWNT have been used, for the first time, in the dye-sensitized solar cells (DSCs. A quasi solid-state DSCs with the hybrid MWNT-PTh composites, an ionic liquid of 1-methyl-3-propyl imidazolium iodide (PMII, was placed between the dye-sensitized porous TiO2 and the Pt counter electrode without adding iodine and higher cell efficiency (4.76% was achieved, as compared to that containing bare PMII (0.29%. The MWNT-PTh nanoparticles are exploited as the extended electron transfer materials and serve simultaneously as catalyst for the electrochemical reduction of I−3.

  16. Bio-Inspired Supramolecular Chemistry Provides Highly Concentrated Dispersions of Carbon Nanotubes in Polythiophene

    Directory of Open Access Journals (Sweden)

    Yen-Ting Lin

    2016-06-01

    Full Text Available In this paper we report the first observation, through X-ray diffraction, of noncovalent uracil–uracil (U–U dimeric π-stacking interactions in carbon nanotube (CNT–based supramolecular assemblies. The directionally oriented morphology determined using atomic force microscopy revealed highly organized behavior through π-stacking of U moieties in a U-functionalized CNT derivative (CNT–U. We developed a dispersion system to investigate the bio-inspired interactions between an adenine (A-terminated poly(3-adeninehexyl thiophene (PAT and CNT–U. These hybrid CNT–U/PAT materials interacted through π-stacking and multiple hydrogen bonding between the U moieties of CNT–U and the A moieties of PAT. Most importantly, the U···A multiple hydrogen bonding interactions between CNT–U and PAT enhanced the dispersion of CNT–U in a high-polarity solvent (DMSO. The morphology of these hybrids, determined using transmission electron microscopy, featured grape-like PAT bundles wrapped around the CNT–U surface; this tight connection was responsible for the enhanced dispersion of CNT–U in DMSO.

  17. Carbon Nanotube Web with Carboxylated Polythiophene "Assist" for High-Performance Battery Electrodes.

    Science.gov (United States)

    Kwon, Yo Han; Park, Jung Jin; Housel, Lisa M; Minnici, Krysten; Zhang, Guoyan; Lee, Sujin R; Lee, Seung Woo; Chen, Zhongming; Noda, Suguru; Takeuchi, Esther S; Takeuchi, Kenneth J; Marschilok, Amy C; Reichmanis, Elsa

    2018-04-24

    A carbon nanotube (CNT) web electrode comprising magnetite spheres and few-walled carbon nanotubes (FWNTs) linked by the carboxylated conjugated polymer, poly[3-(potassium-4-butanoate) thiophene] (PPBT), was designed to demonstrate benefits derived from the rational consideration of electron/ion transport coupled with the surface chemistry of the electrode materials components. To maximize transport properties, the approach introduces monodispersed spherical Fe 3 O 4 (sFe 3 O 4 ) for uniform Li + diffusion and a FWNT web electrode frame that affords characteristics of long-ranged electronic pathways and porous networks. The sFe 3 O 4 particles were used as a model high-capacity energy active material, owing to their well-defined chemistry with surface hydroxyl (-OH) functionalities that provide for facile detection of molecular interactions. PPBT, having a π-conjugated backbone and alkyl side chains substituted with carboxylate moieties, interacted with the FWNT π-electron-rich and hydroxylated sFe 3 O 4 surfaces, which enabled the formation of effective electrical bridges between the respective components, contributing to efficient electron transport and electrode stability. To further induce interactions between PPBT and the metal hydroxide surface, polyethylene glycol was coated onto the sFe 3 O 4 particles, allowing for facile materials dispersion and connectivity. Additionally, the introduction of carbon particles into the web electrode minimized sFe 3 O 4 aggregation and afforded more porous FWNT networks. As a consequence, the design of composite electrodes with rigorous consideration of specific molecular interactions induced by the surface chemistries favorably influenced electrochemical kinetics and electrode resistance, which afforded high-performance electrodes for battery applications.

  18. Polythiophene-coated Fe{sub 3}O{sub 4} superparamagnetic nanocomposite: Synthesis and application as a new sorbent for solid-phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Tahmasebi, Elham [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Yamini, Yadollah, E-mail: yyamini@modares.ac.ir [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Moradi, Morteza; Esrafili, Ali [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of)

    2013-04-03

    Graphical abstract: In the present work, polythiophene-coated Fe{sub 3}O{sub 4} nanoparticles (Fe{sub 3}O{sub 4}@PTh NPs) have been successfully synthesized. The synthesized Fe{sub 3}O{sub 4}@PTh NPs were applied as an efficient sorbent for extraction and pre-concentration of several typical plasticizer compounds from environmental water samples. Highlights: ► A novel polythiophene-coated Fe{sub 3}O{sub 4} nanoparticles (Fe{sub 3}O{sub 4}@PTh NPs) was synthesized. ► The synthesized Fe{sub 3}O{sub 4}@PTh NPs were characterized by using different instruments. ► The Fe{sub 3}O{sub 4}@PTh NPs were applied as a sorbent for extraction of several plasticizers. ► After extraction, separation of NPs from solution was achieved by a magnetic field. ► The proposed procedure was applied to analysis of the analytes in real water samples. -- Abstract: In the present work, a novel type of superparamagnetic nanosorbent, polythiophene-coated Fe{sub 3}O{sub 4} nanoparticles (Fe{sub 3}O{sub 4}@PTh NPs), have been successfully synthesized. The synthesized NPs were characterized by scanning electron microscopy (SEM), Fourier transform-infrared (FT-IR) spectroscopy, and thermal gravimetric analysis (TGA). The synthesized Fe{sub 3}O{sub 4}@PTh NPs were applied as an efficient sorbent for extraction and preconcentration of several typical plasticizer compounds (di-n-butyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP), and dioctyl adipate (DOA)) from environmental water samples. Separation of Fe{sub 3}O{sub 4}@PTh NPs from the aqueous solution was simply achieved by applying external magnetic field. Separation and determination of the extracted plasticizers was performed by gas chromatography–flame ionization detection (GC–FID). Several variables affecting the extraction efficiency of the analytes i.e., amount of NPs sorbent, salt concentration, extraction time, and desorption conditions were investigated and optimized. The best working conditions were as follows: amount

  19. Design of Amperometric Biosensors for the Detection of Glucose Prepared by Immobilization of Glucose Oxidase on Conducting (PolyThiophene Films

    Directory of Open Access Journals (Sweden)

    Maria Pilo

    2018-01-01

    Full Text Available Enzyme-based sensors have emerged as important analytical tools with application in diverse fields, and biosensors for the detection of glucose using the enzyme glucose oxidase have been widely investigated. In this work, the preparation of biosensors by electrochemical polymerization of (polythiophenes, namely 2,2′-bithiophene (2,2′-BT and 4,4′-bis(2-methyl-3-butyn-2-ol-2,2′-bithiophene (4,4′-bBT, followed by immobilization of glucose oxidase on the films, is described. N-cyclohexyl-N′-(2-morpholinoethylcarbodiimide metho-p-toluenesulfonate (CMC was used as a condensing agent, and p-benzoquinone (BQ was used as a redox mediator in solution. The glucose oxidase electrodes with films of 2,2′-BT and 4,4′-bBT were then tested for their ability in detecting glucose from synthetic and real samples (pear, apricot, and peach fruit juices.

  20. Electrochemistry of end-capped oligothienyls. New insights into the polymerization mechanism and the charge storage, conduction and capacitive properties of polythiophene

    Energy Technology Data Exchange (ETDEWEB)

    Zotti, G. (Ist. di Polarografia ed Elettrochimica Preparativa, Consiglio Nazionale delle Ricerche, Padua (Italy)); Schiavon, G. (Ist. di Polarografia ed Elettrochimica Preparativa, Consiglio Nazionale delle Ricerche, Padua (Italy)); Berlin, A. (Dipt. di Chimica Organica e Industriale dell' Univ. e Centro CNR, Speciali Sistemi Organici, Milan (Italy)); Pagani, G. (Dipt. di Chimica Organica e Industriale dell' Univ. e Centro CNR, Speciali Sistemi Organici, Milan (Italy))

    1993-11-23

    The kinetics of anodic coupling to dimers of thiophene oligomers (n=3-5), methyl protected at one [alpha]-terminal position, is second order in oligomer concentration and evidences high activation enthalpies and negative activation entropies. Activation free energies are linearly related to the inverse of the oligomer length n (the dimerization rate decreases as n is increased). Thin films of methyl end-capped thiophene oligomers (n=4, 6, 8 and 10) display reversible oxidations from a single one-electron step (tetramer) to a single two-electron step (octamer and decamer) through two separate one-electron steps (hexamer). ESR indicates strong magnetic dimerization for the one-electron-oxidized hexamer. The close resemblance of the electrochemical and ESR behaviour of the hexamer with that of polythiophene suggests that oxidation of the latter occurs via hexameric spin-dimerized polarons. The conductive and capacitive properties of the end-capped oligomers (n=6, 8 and 10) were investigated by in situ conductivity and chronopotentiometry. While conductivity of octamer and decamer is displayed at the two-electron (bipolaron) state, the hexamer, insulating at this state, is conducting at the mixed-valence polaron-bipolaron state; capacitive responses are evidenced at the bipolaron state for the octamer and decamer only. The difference of conductive and capacitive behaviour between the hexamer and the higher oligomers is explained by charge localization in hexameric segments. (orig.)

  1. Enhancement of the efficiency of dye-sensitized solar cell with multi-wall carbon nanotubes/polythiophene composite counter electrodes prepared by electrodeposition

    Science.gov (United States)

    Luo, Jun; Niu, Hai-jun; Wu, Wen-jun; Wang, Cheng; Bai, Xu-duo; Wang, Wen

    2012-01-01

    For the purpose of increasing the energy conversion efficiency of dye-sensitized solar cells (DSSCs), multi-wall carbon nanotube (MWCNT)/polythiophene (PTh) composite film counter electrode has been fabricated by electrophoresis and cyclic voltammetry (CV) in sequence. The morphology and chemical structure have been characterized by transmission electron microscopy (TEM), scanning electron microscope (SEM), and Raman spectroscopy respectively. The overall energy conversion efficiency of the DSSC employing the MWCNT/PTh composite film has reached 4.72%, which is close to that of the DSSC with a platinum (Pt) counter electrode (5.68%). Compared with a standard DSSC with MWCNT counter electrode whose efficiency is 2.68%, the energy conversion efficiency has been increased by 76.12% for the DSSC with MWCNT/PTh counter electrode. These results indicate that the composite film with high conductivity, high active surface area, and good catalytic properties for I 3- reduction can potentially be used as the counter electrode in a high-performance DSSC.

  2. Polythiophene derivative functionalized with disperse red 1 chromophore: Its third-order nonlinear optical properties through Z-scan technique under continuous and femtosecond irradiation

    Science.gov (United States)

    de la Garza-Rubí, R. M. A.; Güizado-Rodríguez, M.; Mayorga-Cruz, D.; Basurto-Pensado, M. A.; Guerrero-Álvarez, J. A.; Ramos-Ortiz, G.; Rodríguez, M.; Maldonado, J. L.

    2015-08-01

    A copolymer of 3-hexylthiophene and thiophene functionalized with disperse red 1, poly(3-HT-co-TDR1), was synthesized. Chemical structure, molecular weight distribution, optical and thermal properties of this copolymer were characterized by NMR, FT-IR, UV-vis, GPC and DSC-TGA. An optical nonlinear analysis by Z-scan method was also performed for both continuous wave (CW) and pulsed laser pumping. In the CW regime the nonlinearities were evaluated in solid films, and a negative nonlinear refractive index in the range 2.7-4.1 × 10-4 cm2/W was obtained. These values are notoriously high and allowed to observe self-defocusing effects at very low laser intensities: below 1 mW. Further, nonlinear self-phase modulation patterns, during laser irradiation, were also observed. In the pulsed excitation the nonlinear response was evaluated in solution resulting in large two-photon absorption cross section of 5725 GM for the whole copolymer chain and with a value of 232 GM per repeated monomeric unit.

  3. Fabrication of graphene/Fe3O4@polythiophene nanocomposite and its application in the magnetic solid-phase extraction of polycyclic aromatic hydrocarbons from environmental water samples.

    Science.gov (United States)

    Mehdinia, Ali; Khodaee, Nader; Jabbari, Ali

    2015-04-08

    Polythiophene (PT) was used as a surface modifier of graphene/Fe3O4 (G/Fe3O4) composite to increase merit of it, and also overcome some limitations and disadvantages of using G/Fe3O4 alone as solid phase extraction (SPE) sorbent. An in-situ chemical polymerization method was employed to prepare G/Fe3O4@PT nanocomposites. Application of this newly designed material in the magnetic SPE (MSPE) of polycyclic aromatic hydrocarbons (PAHs), as model analytes, in the environmental water samples was investigated. The characterization of the hybrid material was performed using transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray analysis, Fourier transform-infrared (FT-IR) spectroscopy and vibrating sample magnetometry. Seven important parameters, affecting the extraction efficiency of PAHs, including: amount of adsorbent, adsorption and desorption times, type and volume of the eluent solvent, initial sample volume and salt content of the sample were evaluated. The optimum extraction conditions were obtained as: 4 min for extraction time, 20 mg for sorbent amount, 100mL for initial sample volume, toluene as desorption solvent, 0.6 mL for desorption solvent volume, 6 min for desorption time and 30% (w/v) for NaCl concentration. Good performance data were obtained at the optimized conditions. Detection limits were in the range of 0.009-0.020 μg L(-1) in the real matrix. The calibration curves were linear over the concentration ranges from 0.03 to 80 μg L(-1) with correlation coefficients (R(2)) between 0.995 and 0.998 for all the analytes. Relative standard deviations were ranged from 4.3 to 6.3%. Appropriate recovery values, in the range of 83-107%, were also obtained for the real sample analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Hybrid bulk heterojunction solar cells based on poly(3-hexylthiophene) and ZnO nanoparticles modified by side-chain functional polythiophenes

    International Nuclear Information System (INIS)

    Li, Fan; Du, Yanhui; Chen, Yiwang

    2012-01-01

    We report the investigation of the hybrid bulk heterojunction solar cells based on the blend of poly(3-hexylthiophene) (P3HT) and ZnO nanoparticles modified by side-chain thiol functional poly(3-thiophenehexanethiol) (P3HT-SH). Grafting of P3HT-SH onto ZnO nanoparticles can promote the dispersion of ZnO nanoparticles within P3HT matrix and facilitate electron injection process into ZnO nanoparticles, resulting in a more efficient photoinduced charge transfer than that in simple physical mixture of P3HT and non-modified ZnO nanoparticles (P3HT/ZnO). Furthermore, the performance of hybrid photovoltaic device based on P3HT/P3HT-SH-modified ZnO blend exhibits an improved device efficiency compared with P3HT/ZnO even before thermal treatment. After being annealed at 80 °C, the P3HT/P3HT-SH-modified ZnO device shows the power conversion efficiency as high as 0.68%, with the short-circuit current density of 1.89 mA/cm 2 , the open-circuit voltage of 0.599 V and a fill factor of 60.5% under AM 1.5 G illumination with 100 mW/cm 2 light intensity. - Highlights: ► Hybrid solar cells based on poly(3-hexylthiophene) and modified ZnO nanoparticles ► ZnO nanoparticles modified by side-chain functional polythiophenes ► Uniform dispersion and intimate contact between polymers and nanoparticles ► Efficient charge transfer leading to the improvement of device efficiency

  5. Fabrication of graphene/Fe{sub 3}O{sub 4}@polythiophene nanocomposite and its application in the magnetic solid-phase extraction of polycyclic aromatic hydrocarbons from environmental water samples

    Energy Technology Data Exchange (ETDEWEB)

    Mehdinia, Ali, E-mail: mehdinia@inio.ac.ir [Department of Marine Science, Iranian National Institute for Oceanography and Atmospheric Science, Tehran (Iran, Islamic Republic of); Khodaee, Nader; Jabbari, Ali [Department of Chemistry, Faculty of Science, K. N. Toosi University of Technology, Tehran (Iran, Islamic Republic of)

    2015-04-08

    Highlights: • G/Fe{sub 3}O{sub 4}@polythiophene as a novel sorbent for MSPE of PAHs. • Polythiopheneas an efficient modifier of G/Fe{sub 3}O{sub 4}. • G sheets can act as a “support” for the growth of Fe{sub 3}O{sub 4} nanoparticles. • G sheets can act as a “spacer” for the inhibition of NPs aggregation. - Abstract: Polythiophene (PT) was used as a surface modifier of graphene/Fe{sub 3}O{sub 4} (G/Fe{sub 3}O{sub 4}) composite to increase merit of it, and also overcome some limitations and disadvantages of using G/Fe{sub 3}O{sub 4} alone as solid phase extraction (SPE) sorbent. An in-situ chemical polymerization method was employed to prepare G/Fe{sub 3}O{sub 4}@PT nanocomposites. Application of this newly designed material in the magnetic SPE (MSPE) of polycyclic aromatic hydrocarbons (PAHs), as model analytes, in the environmental water samples was investigated. The characterization of the hybrid material was performed using transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray analysis, Fourier transform-infrared (FT-IR) spectroscopy and vibrating sample magnetometry. Seven important parameters, affecting the extraction efficiency of PAHs, including: amount of adsorbent, adsorption and desorption times, type and volume of the eluent solvent, initial sample volume and salt content of the sample were evaluated. The optimum extraction conditions were obtained as: 4 min for extraction time, 20 mg for sorbent amount, 100 mL for initial sample volume, toluene as desorption solvent, 0.6 mL for desorption solvent volume, 6 min for desorption time and 30% (w/v) for NaCl concentration. Good performance data were obtained at the optimized conditions. Detection limits were in the range of 0.009–0.020 μg L{sup −1} in the real matrix. The calibration curves were linear over the concentration ranges from 0.03 to 80 μg L{sup −1} with correlation coefficients (R{sup 2}) between 0.995 and 0.998 for all the analytes

  6. Fast determination of Ziziphora tenuior L. essential oil by inorganic-organic hybrid material based on ZnO nanoparticles anchored to a composite made from polythiophene and hexagonally ordered silica.

    Science.gov (United States)

    Piryaei, Marzieh; Abolghasemi, Mir Mahdi; Nazemiyeh, Hossein

    2015-01-01

    In this paper, for the first time, an inorganic-organic hybrid material based on ZnO nanoparticles was anchored to a composite made from polythiophene and hexagonally ordered silica (ZnO/PT/SBA-15) for use in solid-phase fibre microextraction (SPME) of medicinal plants. A homemade SPME apparatus was used for the extraction of volatile components of Ziziphora tenuior L. A simplex method was used for optimisation of five different parameters affecting the efficiency of the extraction. The main constituents extracted by ZnO/PT/SBA-15 and PDMS fibres and hydrodistillation (HD) methods, respectively, included pulegone (51.25%, 53.64% and 56.68%), limonene (6.73%, 6.58% and 8.3%), caryophyllene oxide (5.33%, 4.31% and 4.53%) and 1,8-cineole (4.21%, 3.31% and 3.18%). In comparison with the HD method, the proposed technique could equally monitor almost all the components of the sample, in an easier way, in a shorter time and requiring a much lower amount of the sample.

  7. Global Derivatives

    DEFF Research Database (Denmark)

    Andersen, Torben Juul

    approaches to dealing in the global business environment." - Sharon Brown-Hruska, Commissioner, Commodity Futures Trading Commission, USA. "This comprehensive survey of modern risk management using derivative securities is a fine demonstration of the practical relevance of modern derivatives theory to risk......" provides comprehensive coverage of different types of derivatives, including exchange traded contracts and over-the-counter instruments as well as real options. There is an equal emphasis on the practical application of derivatives and their actual uses in business transactions and corporate risk...... management situations. Its key features include: derivatives are introduced in a global market perspective; describes major derivative pricing models for practical use, extending these principles to valuation of real options; practical applications of derivative instruments are richly illustrated...

  8. Financial Derivatives

    DEFF Research Database (Denmark)

    Wigan, Duncan

    2013-01-01

    Contemporary derivatives mark the development of capital and constitute a novel form of ownership. By reconfiguring the temporal, spatial and legal character of ownership derivatives present a substantive challenge to the tax collecting state. While fiscal systems are nationally bounded...... and inherently static, capital itself is unprecedentedly mobile, fluid and fungible. As such derivatives raise the specter of ‘financial weapons of mass destruction’....

  9. Financial Derivatives

    OpenAIRE

    Janečková, Alena

    2011-01-01

    1 Abstract/ Financial derivatives The purpose of this thesis is to provide an introduction to financial derivatives which has been, from the legal perspective, described in a not satisfactory manner as quite little literature that can be found about this topic. The main objectives of this thesis are to define the term "financial derivatives" and its particular types and to analyse legal nature of these financial instruments. The last objective is to try to draft future law regulation of finan...

  10. Novel electrochemical redox-active species: one-step synthesis of polyaniline derivative-Au/Pd and its application for multiplexed immunoassay

    Science.gov (United States)

    Wang, Liyuan; Feng, Feng; Ma, Zhanfang

    2015-11-01

    Electrochemical redox-active species play crucial role in electrochemically multiplexed immunoassays. A one-pot method for synthesizing four kinds of new electrochemical redox-active species was reported using HAuCl4 and Na2PdCl4 as dual oxidating agents and aniline derivatives as monomers. The synthesized polyaniline derivative-Au/Pd composites, namely poly(N-methyl-o-benzenediamine)-Au/Pd, poly(N-phenyl-o-phenylenediamine)-Au/Pd, poly(N-phenyl-p-phenylenediamine)-Au/Pd and poly(3,3’,5,5’-tetramethylbenzidine)-Au/Pd, exhibited electrochemical redox activity at -0.65 V, -0.3 V, 0.12 V, and 0.5 V, respectively. Meanwhile, these composites showed high H2O2 electrocatalytic activity because of the presence of Au/Pd. The as-prepared composites were used as electrochemical immunoprobes in simultaneous detection of four tumor biomarkers (carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA199), carbohydrate antigen 72-4 (CA724), and alpha fetoprotein (AFP)). This immunoassay shed light on potential applications in simultaneous gastric cancer (related biomarkers: CEA, CA199, CA724) and liver cancer diagnosis (related biomarkers: CEA, CA199, AFP). The present strategy to the synthesize redox species could be easily extended to other polymers such as polypyrrole derivatives and polythiophene derivatives. This would be of great significance in the electrochemical detection of more analytes.

  11. The Effect of Molecular Structure and Environment on the Miscibility and Diffusivity in Polythiophene-Methanofullerene Bulk Heterojunctions: Theory and Modeling with the RISM Approach

    Directory of Open Access Journals (Sweden)

    Alexander E. Kobryn

    2016-04-01

    Full Text Available Although better means to model the properties of bulk heterojunction molecular blends are much needed in the field of organic optoelectronics, only a small subset of methods based on molecular dynamics- and Monte Carlo-based approaches have been hitherto employed to guide or replace empirical characterization and testing. Here, we present the first use of the integral equation theory of molecular liquids in modelling the structural properties of blends of phenyl-C61-butyric acid methyl ester (PCBM with poly(3-hexylthiophene (P3HT and a carboxylated poly(3-butylthiophene (P3BT, respectively. For this, we use the Reference Interaction Site Model (RISM with the Universal Force Field (UFF to compute the microscopic structure of blends and obtain insight into the miscibility of its components. Input parameters for RISM, such as optimized molecular geometries and charge distribution of interaction sites, are derived by the Density Functional Theory (DFT methods. We also run Molecular Dynamics (MD simulation to compare the diffusivity of the PCBM in binary blends with P3HT and P3BT, respectively. A remarkably good agreement with available experimental data and results of alternative modelling/simulation is observed for PCBM in the P3HT system. We interpret this as a step in the validation of the use of our approach for organic photovoltaics and support of its results for new systems that do not have reference data for comparison or calibration. In particular, for the less-studied P3BT, our results show that expectations about its performance in binary blends with PCBM may be overestimated, as it does not demonstrate the required level of miscibility and short-range structural organization. In addition, the simulated mobility of PCBM in P3BT is somewhat higher than what is expected for polymer blends and falls into a range typical for fluids. The significance of our predictive multi-scale modelling lies in the insights it offers into nanoscale

  12. Derivative chameleons

    International Nuclear Information System (INIS)

    Noller, Johannes

    2012-01-01

    We consider generalized chameleon models where the conformal coupling between matter and gravitational geometries is not only a function of the chameleon field φ, but also of its derivatives via higher order co-ordinate invariants (such as ∂ μ φ∂ μ φ,□φ,...). Specifically we consider the first such non-trivial conformal factor A(φ,∂ μ φ∂ μ φ). The associated phenomenology is investigated and we show that such theories have a new generic mass-altering mechanism, potentially assisting the generation of a sufficiently large chameleon mass in dense environments. The most general effective potential is derived for such derivative chameleon setups and explicit examples are given. Interestingly this points us to the existence of a purely derivative chameleon protected by a shift symmetry for φ → φ+c. We also discuss potential ghost-like instabilities associated with mass-lifting mechanisms and find another, mass-lowering and instability-free, branch of solutions. This suggests that, barring fine-tuning, stable derivative models are in fact typically anti-chameleons that suppress the field's mass in dense environments. Furthermore we investigate modifications to the thin-shell regime and prove a no-go theorem for chameleon effects in non-conformal geometries of the disformal type

  13. Derivative chameleons

    Energy Technology Data Exchange (ETDEWEB)

    Noller, Johannes, E-mail: johannes.noller08@imperial.ac.uk [Theoretical Physics, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2BZ (United Kingdom)

    2012-07-01

    We consider generalized chameleon models where the conformal coupling between matter and gravitational geometries is not only a function of the chameleon field φ, but also of its derivatives via higher order co-ordinate invariants (such as ∂{sub μ}φ∂{sup μ}φ,□φ,...). Specifically we consider the first such non-trivial conformal factor A(φ,∂{sub μ}φ∂{sup μ}φ). The associated phenomenology is investigated and we show that such theories have a new generic mass-altering mechanism, potentially assisting the generation of a sufficiently large chameleon mass in dense environments. The most general effective potential is derived for such derivative chameleon setups and explicit examples are given. Interestingly this points us to the existence of a purely derivative chameleon protected by a shift symmetry for φ → φ+c. We also discuss potential ghost-like instabilities associated with mass-lifting mechanisms and find another, mass-lowering and instability-free, branch of solutions. This suggests that, barring fine-tuning, stable derivative models are in fact typically anti-chameleons that suppress the field's mass in dense environments. Furthermore we investigate modifications to the thin-shell regime and prove a no-go theorem for chameleon effects in non-conformal geometries of the disformal type.

  14. Electricity derivatives

    CERN Document Server

    Aïd, René

    2015-01-01

    Offering a concise but complete survey of the common features of the microstructure of electricity markets, this book describes the state of the art in the different proposed electricity price models for pricing derivatives and in the numerical methods used to price and hedge the most prominent derivatives in electricity markets, namely power plants and swings. The mathematical content of the book has intentionally been made light in order to concentrate on the main subject matter, avoiding fastidious computations. Wherever possible, the models are illustrated by diagrams. The book should allow prospective researchers in the field of electricity derivatives to focus on the actual difficulties associated with the subject. It should also offer a brief but exhaustive overview of the latest techniques used by financial engineers in energy utilities and energy trading desks.

  15. Studies of highly regioregular poly(3-hexylselenophene) for photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L.; Nelson, J.; Bradley, D.D.C. [Department of Physics, Imperial College London, London SW7 2AZ (United Kingdom); Astuti, Y.; Maurano, A.; Shuttle, C.G.; Durrant, J.R. [Department of Chemistry, Imperial College London, London SW7 2AZ (United Kingdom); Heeney, M.; Duffy, W.; McCulloch, I. [Merck Chemicals, Chilworth Science Park, University Parkway, Southampton SO16 7QD (United Kingdom); Ballantyne, A.M.

    2007-12-17

    A selenophene analogue (P3HS) of poly(3-hexylthiophene), P3HT, has been investigated as a replacement for P3HT in bulk heterojunction solar cells. Polymer:PCBM films and devices of both materials are directly compared by studying morphology, optical properties, and device performance. Preliminary optimisation of P3HS:PCBM devices gave promising results with a power conversion energy slightly lower than that of an optimised P3HT:PCBM device measured under identical conditions. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  16. Structure–property relationships of electroluminescent polythiophenes

    Indian Academy of Sciences (India)

    Administrator

    , India. MS received 27 ... Experimentally determined band gap and absorption maxima found to follow the predicted ... emissive material has proven very useful in improving balanced ..... 2.4a Fabrication and analysis of LEDs: Light emitting.

  17. NEW POLYTHIOPHENES WITH OLIGO(OXYETHYLENE) SIDE ...

    African Journals Online (AJOL)

    USER

    The total molecular energies with. Bull. Chem. Soc. Ethiop. 2006, 20(1) .... With respect to Table 2 and 4 this matter is especially seen in ribose ring. Bull. Chem. Soc. Ethiop. 2006 ..... Mitsuya, H.; Broder, S. Nature (London) 1987, 325, 773. 2.

  18. Synthesis, characterization and comparison of polythiophene ...

    Indian Academy of Sciences (India)

    2018-05-25

    May 25, 2018 ... egy is to develop suitable supports to achieve high catalyst dispersion, utilization ... fuel cell, low gas permeability and proton conductivity lead- ing to low ..... The dispersion state showed that the solubility of prepared PTh in ...

  19. 有机噻吩类衍生物作为光伏材料的研究进展%Research Progress of Organic Photovoltaic Materials Based on Thiophene Derivatives

    Institute of Scientific and Technical Information of China (English)

    陈卫星; 张苏艳; 邹敏; 米巧艳

    2012-01-01

    Polythiophene and its derivatives are a class of important organic conjugate polymer materials. They arc ideal polymer solar materials because they are stable in atmosphere and their gaps are very narrow. The development of organic thiophene derivatives in polymer solar cell is summarized. Although there's been a noticeable improvement , a lot of efforts should be put into increasing open-circuit voltage and short circuit current and effciency of energy transfer ,so polymer solar cell can be applied in our lives. Furthermore, the factors about cell performance are analyzed and the prospect of polymer solar cells is previewed.%聚噻吩及其衍生物是一类重要的有机共轭高分子材料,不仅具有良好的环境稳定性,而且带隙窄,是理想的聚合物光伏材料.分类介绍了有机噻吩类衍生物在聚合物太阳能电池中的研究进展及需要改进的地方,如开路电压、短路电流及能量转换效率仍需要大幅度提高才能应用到生活中.展望了聚合物太阳能电池的发展前景.

  20. Novel redox species polyaniline derivative-Au/Pt as sensing platform for label-free electrochemical immunoassay of carbohydrate antigen 199

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Liyuan; Shan, Jiao; Feng, Feng; Ma, Zhanfang, E-mail: mazhanfang@cnu.edu.cn

    2016-03-10

    A novel electrochemical redox-active nanocomposite was synthesized by a one-pot method using N,N′-diphenyl-p-phenylediamine as monomer, and HAuCl{sub 4} and K{sub 2}PtCl{sub 4} as co-oxidizing agents. The as-prepared poly(N,N′-diphenyl-p-phenylediamine)-Au/Pt exhibited admirable electrochemical redox activity at 0.15 V, excellent H{sub 2}O{sub 2} electrocatalytic ability and favorable electron transfer ability. Based on these, the evaluation of the composite as sensing substrate for label-free electrochemical immunosensing to the sensitive detection of carbohydrate antigen 199 was described. This technique proved to be a prospective detection tool with a wide liner range from 0.001 U mL{sup −1} to 40 U mL{sup −1}, and a low detection limit of 2.3 × 10{sup −4} U mL{sup −1} (S/N = 3). In addition, this method was used for the analysis of human serum sample, and good agreement was obtained between the values and those of enzyme-linked immunosorbent assay, implying the potential application in clinical research. Importantly, the strategy of the present substrate could be extended to other polymer-based nanocomposites such as polypyrrole derivatives or polythiophene derivatives, and this could be of great significance for the electrochemical immunoassay. - Highlights: • A novel electrochemical redox composite PPPD-Au/Pt was synthesized by one-pot method. • PPPD-Au/Pt was used as sensing substrate for label-free electrochemical immunosensor. • The immunosensor showed wide detection range and ultralow detection limit for the detection of CA199.

  1. Interest rate derivatives

    DEFF Research Database (Denmark)

    Svenstrup, Mikkel

    This Ph.D. thesis consists of four self-contained essays on valuation of interest rate derivatives. In particular derivatives related to management of interest rate risk care are considered.......This Ph.D. thesis consists of four self-contained essays on valuation of interest rate derivatives. In particular derivatives related to management of interest rate risk care are considered....

  2. Derivatives in emerging markets

    OpenAIRE

    Dubravko Mihaljek; Frank Packer

    2010-01-01

    Turnover of derivatives has grown more rapidly in emerging markets than in developed countries. Foreign exchange derivatives are the most commonly traded of all risk categories, with increasingly frequent turnover in emerging market currencies and a growing share of cross-border transactions. As the global reach of the financial centres in emerging Asia has expanded, the offshore trading of many emerging market currency derivatives has risen as well. Growth in derivatives turnover is positive...

  3. Global Derivatives Market

    Directory of Open Access Journals (Sweden)

    Stankovska Aleksandra

    2017-06-01

    Full Text Available Globalization of financial markets led to the enormous growth of volume and diversification of financial transactions. Financial derivatives were the basic elements of this growth. Derivatives play a useful and important role in hedging and risk management, but they also pose several dangers to the stability of financial markets and thereby the overall economy. Derivatives are used to hedge and speculate the risk associated with commerce and finance.

  4. Risk and Derivative Price

    OpenAIRE

    Yusuke Osaki

    2007-01-01

    We consider an asset market traded three types of assets: the risk–free asset, the market portfolio and derivatives written on the market portfolio return. We determine a sufficient condition to guarantee that noise risk monotonically changes their derivatives. The condition is that Arrow–Pratt absolute risk aversion is decreasing and convex.

  5. Financial Derivatives in China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Francis Repka sees bright prospects for the future development of the financial derivatives market in China. Repka,Vice President of the Asian Bond Finance Department of Societe Generale, says the situation in France just after the birth of derivatives was very similar to the situation in China today.

  6. Vitamin D derivatives

    International Nuclear Information System (INIS)

    Deluca, H.F.; Schnoes, H.K.; Napoli, J.L.; Fivizzani, M.A.

    1982-01-01

    The chemical preparation of 26,27-isotopically labelled vitamin D 3 derivatives of high specific activity is described. These labelled vitamin D derivatives are useful in the determination of vitamin D metabolite levels in the blood and tissues of man and animals. (U.K.)

  7. Taxation of Derivatives

    DEFF Research Database (Denmark)

    Dyppel, Katja Joo

    2013-01-01

    The main objective for this thesis is to analyse and systematise the Danish legislation on taxation of derivatives. According to financial terminology, a derivative is a financial instrument. Its value is derived from changes in the value of one or more underlying assets.The most common derivatives...... in the Danish tax legislation. However, contracts known as forwards (terminskontrakter) and options (aftaler om køberetter og salgsretter) are generally included in the term financials contracts covered by the Danish Act on Taxation of Gains and Losses on Claims and Debt. The main part of the analysis deals...... with the scope of sections 29-33 of the Danish Act on Taxation of Gains and Losses on Claims and Debt and the tax consequences for the covered financial contracts. In the analysis of taxation of derivatives, the fundamental issues of qualification and tax treatment of the instruments are dealt with....

  8. Superstability of Generalized Derivations

    Directory of Open Access Journals (Sweden)

    Ansari-Piri Esmaeil

    2010-01-01

    Full Text Available We investigate the superstability of the functional equation , where and are the mappings on Banach algebra . We have also proved the superstability of generalized derivations associated to the linear functional equation , where .

  9. Amphetamine derivative related deaths.

    Science.gov (United States)

    Lora-Tamayo, C; Tena, T; Rodríguez, A

    1997-02-28

    Amphetamine its methylendioxy (methylendioxyamphetamine methylenedioxymethylamphetamine, methylenedioxyethylamphetamine) and methoxy derivatives (p-methoxyamphetamine and p-methoxymethylamphetamine) are widely abused in Spanish society. We present here the results of a systematic study of all cases of deaths brought to the attention of the Madrid department of the Instituto Nacional de Toxicologia from 1993 to 1995 in which some of these drugs have been found in the cadaveric blood. The cases were divided into three categories: amphetamine and derivatives, amphetamines and alcohol, amphetamines and other drugs. Data on age, sex, clinical symptoms, morphological findings, circumstances of death, when known, and concentration of amphetamine derivatives, alcohol and other drugs in blood are given for each group. The information provided here may prove to be useful for the forensic interpretation of deaths which are directly or indirectly related to abuse of amphetamine derivatives.

  10. Investigation - Derived Waste Program

    International Nuclear Information System (INIS)

    Beardsley, C.; Anderson, R.

    1998-06-01

    The Investigation-Derived Waste Program is a software application that was developed to identify the groundwater monitoring wells at the Savannah River Site that require containerization and treatment for purge water generated during sampling

  11. Development of Derivatives Reporting

    OpenAIRE

    Pejčochová, Kristina

    2012-01-01

    This thesis aims to summarise the theoretical principles, concepts and considerations pertaining to accounting for and reporting of derivatives and to describe and analyse the development of major accounting standards dealing with related issues. Sections 1 and 2 provide a basic overview of derivative instruments'categorisation, mechanics, valuation and uses. Section 3 studies the principles that ensure the provision of useful financial information, with specific focus on financial instrument...

  12. On higher derivative gravity

    International Nuclear Information System (INIS)

    Accioly, A.J.

    1987-01-01

    A possible classical route conducting towards a general relativity theory with higher-derivatives starting, in a sense, from first principles, is analysed. A completely causal vacuum solution with the symmetries of the Goedel universe is obtained in the framework of this higher-derivative gravity. This very peculiar and rare result is the first known vcuum solution of the fourth-order gravity theory that is not a solution of the corresponding Einstein's equations.(Author) [pt

  13. Brain derived neurotrophic factor

    DEFF Research Database (Denmark)

    Mitchelmore, Cathy; Gede, Lene

    2014-01-01

    Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin with important functions in neuronal development and neuroplasticity. Accumulating evidence suggests that alterations in BDNF expression levels underlie a variety of psychiatric and neurological disorders. Indeed, BDNF therapies are curre......Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin with important functions in neuronal development and neuroplasticity. Accumulating evidence suggests that alterations in BDNF expression levels underlie a variety of psychiatric and neurological disorders. Indeed, BDNF therapies...

  14. Gorenstein derived functions

    DEFF Research Database (Denmark)

    Holm, Henrik Granau

    2004-01-01

    Over any associative ring R it is standard to derive HomR(􀀀;􀀀) using projective resolutions in the rst variable, or injective resolutions in the second variable, and doing this, one obtains Extn R(􀀀;􀀀) in both cases. We examine the situation where projective...... and injective modules are replaced by Gorenstein projective and Gorenstein injective ones, respectively. Furthermore, we derive the tensor product 􀀀 R 􀀀 using Gorenstein at modules....

  15. Asia Pacific energy derivatives

    International Nuclear Information System (INIS)

    Fusaro, P.C.

    1997-09-01

    Asia Pacific Energy Derivatives, from FT Energy, is the first report of its kind to examine the growth of energy derivatives within Asia Pacific and their increasing importance within this region. It provides a comprehensive overview of the subject, including analysis of: deregulation as a market driver; the impact of privatisation; the future for energy risk management tools; the unique characteristics of the Asia Pacific energy market; the role of futures exchanges in Asia; existing indexes and their performance; the differences between the Asia Pacific markets and their more mature counterparts in London and New York; non-oil derivatives, project finance and cross commodity arbitrage; the thriving Pacific Rim Over the Counter (OTC) markets. (author)

  16. 4-Aminoquinoline derivatives

    DEFF Research Database (Denmark)

    Singh, Shailja; Agarwal, Drishti; Sharma, Kumkum

    2016-01-01

    and found them to be effective against Plasmodium falciparum under in vitro conditions. Further, we selected four most active derivatives 1m, 1o, 2c and 2j and evaluated their antimalarial potential against Plasmodium berghei in vivo. These 4-aminoquinolines cured BALB/c mice infected with P. berghei......Synthetic quinoline derivatives continue to be considered as candidates for new drug discovery if they act against CQ-resistant strains of malaria even after the widespread emergence of resistance to CQ. In this study, we explored the activities of two series of new 4-aminoquinoline derivatives...... for structure activity relationship to find lead molecules for treating multidrug-resistant Plasmodium falciparum and Plasmodium vivax....

  17. Essays on Derivatives Pricing

    DEFF Research Database (Denmark)

    Kokholm, Thomas

    . With the existence of a liquid market for derivatives with variance as underlying, such as VIX options, VIX futures and a well-developed over-the-counter market for options on variance swaps, it is important to consider models that are able to fit these markets while consistently pricing vanilla options...... financial models, and most importantly, to be aware of their limitations. Following that belief, this thesis consists of three independent and self-contained papers, all dealing with topics in derivatives pricing. The first paper considers the pricing of traffic light options, which are appropriate...... the market for multivariate credit instruments, we take a step back and focus on single-name default modeling and introduce two new model classes for modeling of the default time of a company. Finally, in the third paper we propose a consistent pricing model for index and volatility derivatives...

  18. The combinatorial derivation

    Directory of Open Access Journals (Sweden)

    Igor V. Protasov

    2013-09-01

    $\\Delta(A=\\{g\\in G:|gA\\cap A|=\\infty\\}$. The mapping $\\Delta:\\mathcal{P}_G\\rightarrow\\mathcal{P}_G$, $A\\mapsto\\Delta(A$, is called a combinatorial derivation and can be considered as an analogue of the topological derivation $d:\\mathcal{P}_X\\rightarrow\\mathcal{P}_X$, $A\\mapsto A^d$, where $X$ is a topological space and $A^d$ is the set of all limit points of $A$. Content: elementary properties, thin and almost thin subsets, partitions, inverse construction and $\\Delta$-trajectories,  $\\Delta$ and $d$.

  19. new polythiophenes with oligo(oxyethylene) side chains

    African Journals Online (AJOL)

    USER

    Due to the industrial facilities, heavy metal contents in environmental samples increase ... High performance liquid chromatography (HPLC) ... environmental waters by atomic absorption spectrometry (AAS) is very difficult due to the low.

  20. new polythiophenes with oligo(oxyethylene) side chains

    African Journals Online (AJOL)

    USER

    The presence of this lysine lowers the pKa of CysH3[125]β from the normal value for sulfhydryl groups (between 8 and 8.5) to .... However, DTNB has one disadvantage, it contains a disulfide bond, and the .... The pKa of the reacting sulfhydryl group varies between 5.9 and 6.4, with a mean value of. 6.1±0.2. (c) Assignment ...

  1. new polythiophenes with oligo(oxyethylene) side chains

    African Journals Online (AJOL)

    USER

    In the last decade, a large number of copper(II) complexes have been prepared and ... of glacial acetic acid, was added dropwise a solution of o-vanillin (6.16 g, 40.50 mmol) in 30 .... maximum indicates clearly antiferromagnetic interactions.

  2. new polythiophenes with oligo(oxyethylene) side chains

    African Journals Online (AJOL)

    USER

    was added the metal chloride or nitrate solution while stirring. The reaction mixture ... few drops of dilute ethanolic ammonium hydroxide to obtain the respective solid metal-ligand complex. ... indicating formation of thermally stable species.

  3. new polythiophenes with oligo(oxyethylene) side chains

    African Journals Online (AJOL)

    USER

    1Egerton University, Department of Chemistry, P.O. Box 536, Njoro, Kenya. 2Egerton ... War [13]. However, there is little data available about the chemical characterization of the essentials of the Ocimum .... Institute for Capacity Development).

  4. new polythiophenes with oligo(oxyethylene) side chains

    African Journals Online (AJOL)

    USER

    DETERMINATION OF THE MINOR AND TRACE ELEMENTS IN BIRINIWA'S TIN. PYRITE ... Lead and tin, the major elements, respectively, of the lead/zinc ore and tin ... In Africa, particularly in Nigeria, prior to the advent of modem cosmetics, ...

  5. Development of Polythiophene/Acrylonitrile-Butadiene Rubbers for Artificial Muscle

    Science.gov (United States)

    Thipdech, Pacharavalee; Sirivat, Anuvat

    2007-03-01

    Electroactive polymers (EAPs) can respond to the applied electrical field by an extension or a retraction. In this work, we are interested in using an elastomeric blend for electroactive applications, acrylonitirle-butadiene rubber (NBR) containing a conductive polymer (Poly(3-thiopheneacetic acid, PTAA); the latter can be synthesized via oxidative polymerization. FT-IR, Thermogravimetric analysis (TGA), ^1H-NMR, UV-visible spectroscopy, and SEM are used to characterize the conductive polymer. Electrorheological properties are measured and investigated in terms of acrylonitrile content, blending ratio, doping level, and temperature. Experiments are carried out under oscillatory shear mode and with applied electric field strength varying from 0 to 2 kV/mm. Dielectric properties, conductivities are measured and correlated with the storage modulus responses. The storage modulus sensitivity, δG'G'0of the pure rubbers increases with increasing electric field strength. They attain the maximum values of about 30% and become constant at electric strength at and above 1000 V/mm.

  6. new polythiophenes with oligo(oxyethylene) side chains

    African Journals Online (AJOL)

    USER

    GAS. Laitao Luo*, Zhonghua Gu, Jianjun Guo. Department of Chemistry, Nangchang University, Nangchang, 330047, Jiangxi, P.R. China. (Received June 4 ... KEY WORDS: Purification of exhaust gas, Pt Rh Pd/γ-Al2O3 catalyst, Transition metals .... An ideal d% will result in a useful improvement in catalyst effectiveness.

  7. new polythiophenes with oligo(oxyethylene) side chains

    African Journals Online (AJOL)

    USER

    2Department of Chemistry, University of Port Elizabeth, P.O. Box 1600, 6000 Port ... applications of rhenium radiopharmaceuticals in nuclear medicine[5, 6]. ... This report deals with the synthesis of complexes II, and their reactions with 2-.

  8. new polythiophenes with oligo(oxyethylene) side chains

    African Journals Online (AJOL)

    USER

    above systems for environmental decontamination of organophosphates is discussed. ... and carbamates usually contain solvents such as petroleum distillates ... This kind of self-assembly, inherent to microemulsions, results in the .... applied to the soil depends largely on two of its properties: persistence and adsorption.

  9. The Photo-Physics of Polythiophene Nanoparticles for Biological Applications.

    Science.gov (United States)

    Bargigia, Ilaria; Zucchetti, Elena; Srimath Kandada, Ajay Ram; Moreira, Miguel; Bossio, Caterina; Wong, Walter; Miranda, Paulo; Decuzzi, Paolo; Soci, Cesare; D'Andrea, Cosimo; Lanzani, Guglielmo

    2018-05-01

    In this work the photo-physics of poly(3-hexyltiophene) nanoparticles (NPs) is investigated in the context of their biological applications. The NPs made as colloidal suspensions in aqueous buffers present a distinct absorption band in the low energy region. Based on systematic analysis of absorption and transient absorption spectra taken under different pH conditions, this band is associated to charge transfer states generated by the polarization of loosely bound polymer chains and originated from complexes formed with electron withdrawing species. Importantly, the ground state depletion of these states upon photo-excitation is active even in the microsecond timescales, suggesting that they act as precursor states for long-living polarons which could be beneficial for cellular stimulation. Preliminary results of transient absorption microscopy of NPs internalized within the cells reveal the presence of long-living species, further substantiating their relevance in bio-interfaces. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. new polythiophenes with oligo(oxyethylene) side chains

    African Journals Online (AJOL)

    USER

    aDepartment of Chemistry, Faculty of Science, University of Douala, P.O. Box 24157, Douala,. Cameroon. bLaboratoire de Chimie des Substances Naturelles, USM 0502 MNHN - UMR 5154 CNRS, 63 rue Buffon-75005 Paris, France. cDepartment of Organic Chemistry, Faculty of Science, University of Yaounde I, P.O. Box ...

  11. new polythiophenes with oligo(oxyethylene) side chains

    African Journals Online (AJOL)

    USER

    ORGANOSILICON CHEMISTRY I: CYCLOPROPANATION BY CARBENE OR. CARBENOID ... ammonium salt was highly hygroscopic. Related ... which stress the necessity of operating under anhydrous condition, due to rapid hydrolysis of.

  12. Quinazolin-4-one derivatives

    DEFF Research Database (Denmark)

    Mosley, Cara A; Acker, Timothy M; Hansen, Kasper Bø

    2010-01-01

    We describe a new class of subunit-selective antagonists of N-methyl D-aspartate (NMDA)-selective ionotropic glutamate receptors that contain the (E)-3-phenyl-2-styrylquinazolin-4(3H)-one backbone. The inhibition of recombinant NMDA receptor function induced by these quinazolin-4-one derivatives...

  13. Metal borohydrides and derivatives

    DEFF Research Database (Denmark)

    Paskevicius, Mark; Haarh Jepsen, Lars; Schouwink, Pascal

    2017-01-01

    major classes of metal borohydride derivatives have also been discovered: anion-substituted compounds where the complex borohydride anion, BH4 -, is replaced by another anion, i.e. a halide or amide ion; and metal borohydrides modified with neutral molecules, such as NH3, NH3BH3, N2H4, etc. Here, we...

  14. 78 FR 32191 - Derivatives

    Science.gov (United States)

    2013-05-29

    ... rate risk. This proposed rule applies to federal credit unions and any federally insured, state... risk to the National Credit Union Share Insurance Fund (NCUSIF). \\1\\ A derivative is an instrument... degrees of risk to a credit union. Accordingly, this risk calls for a more robust asset/ liability...

  15. Superstability of Generalized Derivations

    Directory of Open Access Journals (Sweden)

    Esmaeil Ansari-Piri

    2010-01-01

    Full Text Available We investigate the superstability of the functional equation f(xy=xf(y+g(xy, where f and g are the mappings on Banach algebra A. We have also proved the superstability of generalized derivations associated to the linear functional equation f(γx+βy=γf(x+βf(y, where γ,β∈ℂ.

  16. Approximate *-derivations and approximate quadratic *-derivations on C*-algebras

    Directory of Open Access Journals (Sweden)

    Park Choonkil

    2011-01-01

    Full Text Available Abstract In this paper, we prove the stability of *-derivations and of quadratic *-derivations on Banach *-algebras. We moreover prove the superstability of *-derivations and of quadratic *-derivations on C*-algebras. 2000 Mathematics Subject Classification: 39B52; 47B47; 46L05; 39B72.

  17. Derived enriched uranium market

    International Nuclear Information System (INIS)

    Rutkowski, E.

    1996-01-01

    The potential impact on the uranium market of highly enriched uranium from nuclear weapons dismantling in the Russian Federation and the USA is analyzed. Uranium supply, conversion, and enrichment factors are outlined for each country; inventories are also listed. The enrichment component and conversion components are expected to cause little disruption to uranium markets. The uranium component of Russian derived enriched uranium hexafluoride is unresolved; US legislation places constraints on its introduction into the US market

  18. Computation of Mie derivatives.

    Science.gov (United States)

    Li, Yang; Bowler, Nicola

    2013-07-10

    Analytical expressions are obtained for the derivatives of Mie scattering coefficients with respect to the electrical radius of the spherical scattering particle, and to the relative permittivity and permeability of both the particle and the surrounding medium. Their corresponding approximate expressions are developed to avoid numerical overflow based on the logarithmic derivative of Riccati-Bessel functions. The analytical expressions have been verified by comparing their results with those calculated by analytical expressions developed by Mathematica. Compared with the numerical derivative, the analytical expressions and approximate expressions show a higher accuracy and are 2.0 and 2.8 times, respectively, faster in the case of a single magnetodielectric sphere. Generally, for spheres with an electrical radius in a large range, the approximate expressions can yield acceptable accuracy and computation time up to a high order. This work can be used in the design of nonmetallic metamaterials, and in the retrieval of aerosol properties from remote sensing data. An example calculation is given for the design of an optical, all-dielectric, mu-negative metamaterial consisting of a simple cubic array of tellurium nanoparticles.

  19. Carnitine derivatives: clinical usefulness.

    Science.gov (United States)

    Malaguarnera, Mariano

    2012-03-01

    Carnitine and its derivatives are natural substances involved in both carbohydrate and lipid metabolism. This review summarizes the recent progress in the field in relation to the molecular mechanisms. The pool of different carnitine derivatives is formed by acetyl-L-carnitine (ALC), propionyl-L-carnitine (PLC), and isovaleryl-carnitine. ALC may have a preferential effect on the brain tissue. ALC represents a compound of great interest for its wide clinical application in various neurological disorders: it may be of benefit in treating Alzheimer's dementia, depression in the elderly, HIV infection, chronic fatigue syndrome, peripheral neuropathies, ischemia and reperfusion of the brain, and cognitive impairment associated with various conditions. PLC has been demonstrated to replenish the intermediates of the tricarboxylic acid cycle by the propionyl-CoA moiety, a greater affinity for the sarcolemmal carrier, peripheral vasodilator activity, a greater positive inotropism, and more rapid entry into myocytes. Most studies of the therapeutic use of PLC are focused on the prevention and treatment of ischemic heart disease, congestive heart failure, hypertrophic heart disease, and peripheral arterial disease. ALC and PLC are considered well tolerated without significant side-effects. A number of therapeutic effects possibly come from the interaction of carnitine and its derivatives with the elements of cellular membranes.

  20. Multifunctional Cinnamic Acid Derivatives

    Directory of Open Access Journals (Sweden)

    Aikaterini Peperidou

    2017-07-01

    Full Text Available Our research to discover potential new multitarget agents led to the synthesis of 10 novel derivatives of cinnamic acids and propranolol, atenolol, 1-adamantanol, naphth-1-ol, and (benzylamino ethan-1-ol. The synthesized molecules were evaluated as trypsin, lipoxygenase and lipid peroxidation inhibitors and for their cytotoxicity. Compound 2b derived from phenoxyphenyl cinnamic acid and propranolol showed the highest lipoxygenase (LOX inhibition (IC50 = 6 μΜ and antiproteolytic activity (IC50 = 0.425 μΜ. The conjugate 1a of simple cinnamic acid with propranolol showed the higher antiproteolytic activity (IC50 = 0.315 μΜ and good LOX inhibitory activity (IC50 = 66 μΜ. Compounds 3a and 3b, derived from methoxylated caffeic acid present a promising combination of in vitro inhibitory and antioxidative activities. The S isomer of 2b also presented an interesting multitarget biological profile in vitro. Molecular docking studies point to the fact that the theoretical results for LOX-inhibitor binding are identical to those from preliminary in vitro study.

  1. Credit derivatives and risk management

    OpenAIRE

    Michael S. Gibson

    2007-01-01

    The striking growth of credit derivatives suggests that market participants find them to be useful tools for risk management. I illustrate the value of credit derivatives with three examples. A commercial bank can use credit derivatives to manage the risk of its loan portfolio. An investment bank can use credit derivatives to manage the risks it incurs when underwriting securities. An investor, such as an insurance company, asset manager, or hedge fund, can use credit derivatives to align its...

  2. Credit derivatives in emerging markets

    OpenAIRE

    Romain Rancière

    2002-01-01

    Credit Derivatives are securities that offer protection against credit or default risk of bonds or loans. The credit derivatives emerging market has grown rapidly and credit derivatives are widely used. This paper describes the emerging credit derivatives market structure. The current market activity is analyzed through elementary pricing dynamics and the study of the term structure of default risk. Focusing on the performance of credit derivatives in stress situation, including legal and mar...

  3. In defense of derivations

    Science.gov (United States)

    Mungan, Carl E.

    2016-05-01

    At the 2015 AAPT Summer Meeting, I presented four derivations of the formula for motional emf. Such physics derivations involve the construction of explanatory frameworks involving diagrams and mathematical models. Although textbooks devote considerable space to such explanations, many teachers and students spend their time on worksheets, end-of-chapter problems, and the like. The book is reduced to a bank of solved (i.e., example) and unsolved (i.e., homework) questions, along with equations in colored boxes that presumably are to be used to answer those questions. Such an approach encourages fragmentation of knowledge, the view that there is only one right answer to a problem with the goal of physics being to find that answer (neatly boxed of course), and the inability to reason about even a slightly different (much less a novel) situation. If we are to develop scientific literacy, significant course time must be devoted to explaining the structure of and support for the models and equations we use.

  4. Conformation, molecular packing and field effect mobility of regioregular beta,beta'-dihexylsexithiophiophene

    DEFF Research Database (Denmark)

    Kiriy, N.; Kiriy, A.; Bocharova, V.

    2004-01-01

    by the pulse-radiolysis time-resolved microwave conductivity (PR-TRMC) technique was found to be Sigmamu(min) = 3.9 x 10(-3) cm(2) V-1 s(-1), which is comparable with the PR-TRMC mobility found for alpha,omega-DH6T. The field-effect mobility (FEM) of beta,beta'-DH6T was found to be on the order of 10(-5) cm(2......) V-1 s(-1), which is considerably less than the FEM of alpha,omega-DH6T. To understand the reason for such poor macroscopic electrical properties, the conformation and the molecular packing of beta,beta'-DH6T were systematically studied by means of UV-vis spectroscopy, scanning electron microscopy...... less dense crystalline packing than alpha,omega-DH6T. In contrast to the almost upright orientation of alpha,omega-DH6T molecules against the substrate (tilt angle about 68), the long axis of beta,beta'-DH6T molecules and the surface plane form an angle of similar to20degrees. Thus, the crystalline...

  5. 6-Bromocholesterol derivatives

    International Nuclear Information System (INIS)

    Flanagan, R.J.

    1984-01-01

    Novel 6-bromo derivatives of cholesterol have the formula 3-(R-O-),6-BR,17-((H3C-)2-HC-H2C-H2C-H2C-HC(-CH3)-)-ESTR-5-ENE Such compounds are prepared from the known 6-iodocholesterol by treatment with cuprous bromide. These compounds, labelled with radioisotopes of Br-82 or Br-77, are localized in the adrenal, mammary and ovary tissue of female mammals and in the adrenal or prostate tissue of males when administered to such individuals. This provides a method for imaging adrenal, ovary or prostate tissue which is superior to use of the prior art 6-iodo-cholesterol

  6. Algae Derived Biofuel

    Energy Technology Data Exchange (ETDEWEB)

    Jahan, Kauser [Rowan Univ., Glassboro, NJ (United States)

    2015-03-31

    One of the most promising fuel alternatives is algae biodiesel. Algae reproduce quickly, produce oils more efficiently than crop plants, and require relatively few nutrients for growth. These nutrients can potentially be derived from inexpensive waste sources such as flue gas and wastewater, providing a mutual benefit of helping to mitigate carbon dioxide waste. Algae can also be grown on land unsuitable for agricultural purposes, eliminating competition with food sources. This project focused on cultivating select algae species under various environmental conditions to optimize oil yield. Membrane studies were also conducted to transfer carbon di-oxide more efficiently. An LCA study was also conducted to investigate the energy intensive steps in algae cultivation.

  7. SEMANTIC DERIVATION OF BORROWINGS

    Directory of Open Access Journals (Sweden)

    Shigapova, F.F.

    2017-09-01

    Full Text Available The author carried out the contrastive analysis of the word спикер borrowed into Russian from English and the English word speaker. The findings of the analysis include confirm (1 different derivational abilities and functions of the borrowed word and the native word; (2 distinctive features in the definitions, i.e. semantic structures, registered in monolingual non-abridged dictionaries; (3 heterogeneous parameters of frequencies recorded in the National Corpus of the Russian language and the British National Corpus; (4 absence of bilingual equivalent collocations with words спикер and speaker. The collocations with words studied revealed new lexical and connotative senses in the meaning of the word. Relevance of the study conducted is justified by the new facts revealed about the semantic adaptation of the borrowed word in the system of the Russian language and its paradigmatic and syntagmatic connections in the system of the recipient language.

  8. Original and Derived Judgment

    DEFF Research Database (Denmark)

    Foss, Kirsten; Foss, Nicolai Juul; Klein, Peter G.

    2007-01-01

    Recent work links entrepreneurship to the economic theory of the firm, using the concept of entrepreneurship as judgment introduced by Frank Knight. When judgment is complementary to other assets, it makes sense for entrepreneurs to hire labour and to own assets. The entrepreneur's role, then...... to subordinates, who exercise derived judgment. We call these employees `proxy-entrepreneurs', and ask how the firm's organizational structure - its formal and informal systems of rewards and punishments, rules for settling disputes and renegotiating agreements, means of evaluating performance and so on - can...... be designed to encourage forms of proxy entrepreneurship that increase firm value while discouraging actions that destroy value. Building on key ideas from the entrepreneurship literature, Austrian economics and the economic theory of the firm, we develop a framework for analysing the trade-off between...

  9. H- and J-aggregate behavior in polymeric semiconductors.

    Science.gov (United States)

    Spano, Frank C; Silva, Carlos

    2014-01-01

    Aggregates of conjugated polymers exhibit two classes of fundamental electronic interactions: those occurring within a given chain and those occurring between chains. The impact of such excitonic interactions on the photophysics of polymer films can be understood using concepts of J- and H-aggregation originally developed by Kasha and coworkers to treat aggregates of small molecules. In polymer assemblies, intrachain through-bond interactions lead to J-aggregate behavior, whereas interchain Coulombic interactions lead to H-aggregate behavior. The photophysics of common emissive conjugated polymer films are determined by a competition between intrachain, J-favoring interactions and interchain, H-favoring interactions. We review formalisms describing absorption and photoluminescence lineshapes, based on intra- and intermolecular excitonic coupling, electron-vibrational coupling, and correlated energetic disorder. Examples include regioregular polythiophenes, pheneylene-vinylenes, and polydiacetylene.

  10. Piroxicam derivatives THz classification

    Science.gov (United States)

    Sterczewski, Lukasz A.; Grzelczak, Michal P.; Nowak, Kacper; Szlachetko, Bogusław; Plinska, Stanislawa; Szczesniak-Siega, Berenika; Malinka, Wieslaw; Plinski, Edward F.

    2016-02-01

    In this paper we report a new approach to linking the terahertz spectral shapes of drug candidates having a similar molecular structure to their chemical and physical parameters. We examined 27 newly-synthesized derivatives of a well-known nonsteroidal anti-inflammatory drug Piroxicam used for treatment of inflammatory arthritis and chemoprevention of colon cancer. The testing was carried out by means of terahertz pulsed spectroscopy (TPS). Using chemometric techniques we evaluated their spectral similarity in the terahertz range and attempted to link the position on the principal component analysis (PCA) score map to the similarity of molecular descriptors. A simplified spectral model preserved 75% and 85.1% of the variance in 2 and 3 dimensions respectively, compared to the input 1137. We have found that in 85% of the investigated samples a similarity of the physical and chemical parameters corresponds to a similarity in the terahertz spectra. The effects of data preprocessing on the generated maps are also discussed. The technique presented can support the choice of the most promising drug candidates for clinical trials in pharmacological research.

  11. Experts' understanding of partial derivatives using the Partial Derivative Machine

    OpenAIRE

    Roundy, David; Dorko, Allison; Dray, Tevian; Manogue, Corinne A.; Weber, Eric

    2014-01-01

    Partial derivatives are used in a variety of different ways within physics. Most notably, thermodynamics uses partial derivatives in ways that students often find confusing. As part of a collaboration with mathematics faculty, we are at the beginning of a study of the teaching of partial derivatives, a goal of better aligning the teaching of multivariable calculus with the needs of students in STEM disciplines. As a part of this project, we have performed a pilot study of expert understanding...

  12. Derivative spectrophotometry of cobalt alloys

    International Nuclear Information System (INIS)

    Spitsyn, P.K.

    1985-01-01

    The method of derivative spectrophotometry is briefly described, and derivative absorption spectra are presented for samarium, cobalt, and commercial Sm-Co alloys. It is shown that the use of derivative spectrophotometry not only improves the accuracy and selectivity of element determinations but also simplifies the analysis of alloys. Results of a statistical evaluation of the metrological characteristics of the analytical procedure described here are presented. 8 references

  13. Central Clearing of OTC Derivatives

    DEFF Research Database (Denmark)

    Cont, Rama; Kokholm, Thomas

    2014-01-01

    netting agreements. When a CCP exists for interest rate derivatives, adding a CCP for credit derivatives is shown to decrease overall exposures. These findings are shown to be robust to the statistical assumptions of the model as well as the choice of risk measure used to quantify exposures....

  14. Chemistry of aliphatic sulfurpentafluoride derivatives

    International Nuclear Information System (INIS)

    Bissell, E.R.

    1975-01-01

    This report summarizes the literature through 1974 on aliphatic sulfurpentafluoride compounds. Methods of preparation and methods of transforming one pentafluorothio compound into another are briefly discussed. The physical properties of all known derivatives are tabulated

  15. Higher derivatives in gauge transformations

    International Nuclear Information System (INIS)

    Gogilidze, S.A.; Sanadze, V.V.; Tkebuchava, F.G.

    1992-01-01

    The mechanism of appearance of highher derivatives of coordinates in the symmetry transformation law of the second Noether's theorem is established. It is shown that the corresponding transformations are canonical in the extended phase space. 15 refs

  16. Push-outs of derivations

    Indian Academy of Sciences (India)

    extension as a limit of operators b ↦→ D(ba) − b.D(a), a ∈ A in an appropriate operator topology, the main point in the proof being to show that the limit map is in fact a derivation. In this paper we make clear which part of this approach is analytic and which algebraic by presenting an algebraic scheme that gives derivations ...

  17. Elementary derivation of Kepler's laws

    International Nuclear Information System (INIS)

    Vogt, E.

    1995-02-01

    A simple derivation of all three so-called Kepler Laws is presented in which the orbits, bound and unbound, follow directly and immediately from conservation of energy and angular momentum. The intent is to make this crowning achievement of Newtonian Mechanics easily accessible to students in introductory physics courses. The method is also extended to simplify the derivation of the Rutherford Scattering Law. (author). 4 refs., 3 figs

  18. Derivatives Trading and Negative Voting

    OpenAIRE

    Spamann, Holger

    2012-01-01

    This paper exposits a model of parallel trading of corporate securities (shares, bonds) and derivatives in which a large trader can sometimes profitably acquire securities with their corporate control rights for the sole purpose of reducing the corporations value and gaining on a net short position created through off-setting derivatives. At other times, the large trader profitably takes a net long position. The large trader requires no private information beyond its own trades. The problem i...

  19. Quinazoline derivatives: synthesis and bioactivities

    OpenAIRE

    Wang, Dan; Gao, Feng

    2013-01-01

    Owing to the significant biological activities, quinazoline derivatives have drawn more and more attention in the synthesis and bioactivities research. This review summarizes the recent advances in the synthesis and biological activities investigations of quinazoline derivatives. According to the main method the authors adopted in their research design, those synthetic methods were divided into five main classifications, including Aza-reaction, Microwave-assisted reaction, Metal-mediated reac...

  20. Anisotropic inflation with derivative couplings

    Science.gov (United States)

    Holland, Jonathan; Kanno, Sugumi; Zavala, Ivonne

    2018-05-01

    We study anisotropic power-law inflationary solutions when the inflaton and its derivative couple to a vector field. This type of coupling is motivated by D-brane inflationary models, in which the inflaton, and a vector field living on the D-brane, couple disformally (derivatively). We start by studying a phenomenological model where we show the existence of anisotropic solutions and demonstrate their stability via a dynamical system analysis. Compared to the case without a derivative coupling, the anisotropy is reduced and thus can be made consistent with current limits, while the value of the slow-roll parameter remains almost unchanged. We also discuss solutions for more general cases, including D-brane-like couplings.

  1. Sol-gel derived sorbents

    Science.gov (United States)

    Sigman, Michael E.; Dindal, Amy B.

    2003-11-11

    Described is a method for producing copolymerized sol-gel derived sorbent particles for the production of copolymerized sol-gel derived sorbent material. The method for producing copolymerized sol-gel derived sorbent particles comprises adding a basic solution to an aqueous metal alkoxide mixture for a pH.ltoreq.8 to hydrolyze the metal alkoxides. Then, allowing the mixture to react at room temperature for a precalculated period of time for the mixture to undergo an increased in viscosity to obtain a desired pore size and surface area. The copolymerized mixture is then added to an immiscible, nonpolar solvent that has been heated to a sufficient temperature wherein the copolymerized mixture forms a solid upon the addition. The solid is recovered from the mixture, and is ready for use in an active sampling trap or activated for use in a passive sampling trap.

  2. Synthesis of 2-phosphaadamantane derivatives

    International Nuclear Information System (INIS)

    Zemlyanoi, V.N.; Aleksandrov, A.M.; Kukhar', V.P.

    1986-01-01

    The authors describe the synthesis and properties of 2-phosphadamantane derivatives. For the synthesis of 2-phosphaadamantane derivatives they decided to use the methodology of the synthesis of 2-thiaadamantane. The IR spectra were determined on CHCl 3 solutions with a Specord 711R spectrometer, the PMR spectra were determined on Tesla BS-467 (60 MHz) and Bruker WP-200 (200 MHz) spectrometers, external standard hexamethyldisiloxane, the 31 P NMR spectra were determined on Tesla BS-487 C (30 MHz) and Bruker WP-200 (81 MHz) spectrometers, external standard 85% phosphoric acid, and the mass spectra were determined on an MS-1302 spectrometer

  3. Bounded Densities and Their Derivatives

    DEFF Research Database (Denmark)

    Kozine, Igor; Krymsky, V.

    2009-01-01

    This paper describes how one can compute interval-valued statistical measures given limited information about the underlying distribution. The particular focus is on a bounded derivative of a probability density function and its combination with other available statistical evidence for computing ...... quantities of interest. To be able to utilise the evidence about the derivative it is suggested to adapt the ‘conventional’ problem statement to variational calculus and the way to do so is demonstrated. A number of examples are given throughout the paper....

  4. Risk Factors in Derivatives Markets

    Directory of Open Access Journals (Sweden)

    Raimonda Martinkutė-Kaulienė

    2015-02-01

    Full Text Available The objective of the article is to analyse and present the classification of risks actual to derivative securities. The analysis is based on classical and modern literature findings and analysis of newest statistical data. The analysis led to the conclusion, that the main risks typical for derivatives contracts and their traders are market risk, liquidity risk, credit and counterparty risk, legal risk and transactions risk. Pricing risk and systemic risk is also quite important. The analysis showed that market risk is the most important kind of risk that in many situations influences the level of remaining risks.

  5. Analytical application of derivative spectrophotometry

    Directory of Open Access Journals (Sweden)

    VIOLETA M. STEFANOVIC

    2000-07-01

    Full Text Available 1. Introduction 2. Basic characteristics of derivative spectrophotometry 2.1. Increase of spectra resolution 2.2. Elimination of the influence of baseline shift and matrix interferences 2.3. Enhancement of the detectability of minor spectral features 2.4. Precise determination of the positions of absorption maxima 2.5. Signal-to-noise ratio (SNR 2.6. Quantitative analysis 3. Analytical applications 3.1. Inorganic analysis 3.2. Organic and pharmaceutical analysis 3.3. Analysis of food and water 3.4. Application of derivative spectrophotometry for the determination of equilibrium constants

  6. Derived equivalences for group rings

    CERN Document Server

    König, Steffen

    1998-01-01

    A self-contained introduction is given to J. Rickard's Morita theory for derived module categories and its recent applications in representation theory of finite groups. In particular, Broué's conjecture is discussed, giving a structural explanation for relations between the p-modular character table of a finite group and that of its "p-local structure". The book is addressed to researchers or graduate students and can serve as material for a seminar. It surveys the current state of the field, and it also provides a "user's guide" to derived equivalences and tilting complexes. Results and proofs are presented in the generality needed for group theoretic applications.

  7. Doping kinetics of organic semiconductors investigated by field-effect transistors

    NARCIS (Netherlands)

    Maddalena, F.; Meijer, E.J.; Asadi, K.; Leeuw, D.M. de; Blom, P.W.M.

    2010-01-01

    The kinetics of acid doping of the semiconductor regioregular poly-3-hexylthiophene with vaporized chlorosilane have been investigated using field-effect transistors. The dopant density has been derived as a function of temperature and exposure time from the shift in the pinch-off voltage, being the

  8. derivatives: Synthesis and antimicrobial evaluation

    Indian Academy of Sciences (India)

    cal activity study revealed that all compounds showed promising activities and bis-(1H-2-benzopyran-1-one) derivatives (5) ...... A and Galvez J 2004 Planta Med. 70 315. 6. ... Ante N, Erik De C, Jan B and Mladen M 2011 Molecules. 16 6023.

  9. Second derivative spectrophotometric determination of ...

    African Journals Online (AJOL)

    A new, simple, rapid, wide applicable range and reliable second derivative spectrophotometric method has been developed for determination of cyclophosphamide (CP) in bulk and pharmaceutical dosage forms. Calibration graph is linear in the concentration range of 25 - 200 μg/ml of CP with 10 μg/ml of detection limit and ...

  10. Hypoxanthine Derivatives in Experimental Infections

    Directory of Open Access Journals (Sweden)

    Claudio De Simone

    1992-01-01

    ability of ST 789 to increase interleukin-6 production, suggest that monocyte/macrophages are likely to be the main cellular target of the immunomodulating activity of ST 789. Finally, in the presentln vivo study, hypoxanthine derivatives did not enhance the mean survival time of tumour-bearing immunosuppressed mice.

  11. Radiological protection optimization using derivatives

    International Nuclear Information System (INIS)

    Freitas Acosta Perez, C. de; Sordi, G.M.A.A.

    2006-01-01

    The aim of this paper is to provide a different approach related to the integral cost-benefit and extended cost-benefit analysis used in the decision-aiding techniques. In the ICRP publication 55 the annual protection cost is envisaged as a set of points, each of them representing an option, linked by a straight line. The detriment cost function is considered a linear function whose angular coefficient is determined by the alpha value. In this paper the uranium mine example considered in the ICRP publication 55 was used. But the potential curve was introduced both in the integral cost benefit analysis and in the extended cost-benefit analysis, which the individual dose distribution attribute is added. The result was obtained using derivatives. The detriment cost, Y, is not necessary because the alpha value is known. The Y derivative dS/dY is the alpha value itself and so, the attention is directed to the derivative -dX/dS on the points that, along with the alpha value, present the optimum option. The results makes clear that the prevailing factor in the optimum option selection is the alpha value imputed, and those a single alpha value, as suggested now, probably as little efficiency on the optimization process. Obtaining a curve for the alpha value and using the derivative technique introduced in this paper, the analytical solution is more convenient and reliable compared to the one used now. (authors)

  12. Alchemical derivatives of reaction energetics

    Science.gov (United States)

    Sheppard, Daniel; Henkelman, Graeme; von Lilienfeld, O. Anatole

    2010-08-01

    Based on molecular grand canonical ensemble density functional theory, we present a theoretical description of how reaction barriers and enthalpies change as atoms in the system are subjected to alchemical transformations, from one element into another. The change in the energy barrier for the umbrella inversion of ammonia is calculated along an alchemical path in which the molecule is transformed into water, and the change in the enthalpy of protonation for methane is calculated as the molecule is transformed into a neon atom via ammonia, water, and hydrogen fluoride. Alchemical derivatives are calculated analytically from the electrostatic potential in the unperturbed system, and compared to numerical derivatives calculated with finite difference interpolation of the pseudopotentials for the atoms being transformed. Good agreement is found between the analytical and numerical derivatives. Alchemical derivatives are also shown to be predictive for integer changes in atomic numbers for oxygen binding to a 79 atom palladium nanoparticle, illustrating their potential use in gradient-based optimization algorithms for the rational design of catalysts.

  13. Radiolabeled derivatives of folic acid

    International Nuclear Information System (INIS)

    1980-01-01

    Derivatives of folic acid are described, in which the α-carboxyl group is substituted with an amino compound having an aromatic or heterocyclic ring substituent which is capable of being radiolabelled. Particularly mentioned as a radiolabel is 125 I. (author)

  14. Second derivative spectrophotometric determination of ...

    African Journals Online (AJOL)

    Hemn

    2013-11-13

    Nov 13, 2013 ... olanzapine in pharmaceutical formulation.Int.J.ChemTech. Res.2(1):756-761. Stanisz B, Paszun S, Lesniak M (2009). Validation of UV derivative spectrophotometric method for determination of benazepril hydrochloride in tablets and evaluation of its stability.ActaPoloniaePharmaceutica-Drug Research.

  15. Novel bisstyryl derivatives of bakuchiol

    DEFF Research Database (Denmark)

    Reddy, Mallepally V; Thota, Niranjan; Sangwan, Payare L

    2010-01-01

    Novel bisstyryl derivatives of bakuchiol using Heck coupling reaction as the key step were synthesized and screened against a panel of six oral cavity pathogens for their antimicrobial activity. Four compounds (9-12) showed two to fourfold and four to eightfold better activity (MIC 0.25-16 microg...

  16. Push-outs of derivations

    DEFF Research Database (Denmark)

    Grønbæk, Niels

    2008-01-01

    Let A be a Banach algebra and let X be a Banach A-bimodule. In studying H¹(A,X) it is often useful to extend a given derivation D: A->X to a Banach algebra B containing A as an ideal, thereby exploiting (or establishing) hereditary properties. This is usually done using (bounded/unbounded) approx...

  17. Asymptotic aspect of derivations in Banach algebras

    Directory of Open Access Journals (Sweden)

    Jaiok Roh

    2017-02-01

    Full Text Available Abstract We prove that every approximate linear left derivation on a semisimple Banach algebra is continuous. Also, we consider linear derivations on Banach algebras and we first study the conditions for a linear derivation on a Banach algebra. Then we examine the functional inequalities related to a linear derivation and their stability. We finally take central linear derivations with radical ranges on semiprime Banach algebras and a continuous linear generalized left derivation on a semisimple Banach algebra.

  18. Higher-derivative generalization of conformal mechanics

    Science.gov (United States)

    Baranovsky, Oleg

    2017-08-01

    Higher-derivative analogs of multidimensional conformal particle and many-body conformal mechanics are constructed. Their Newton-Hooke counterparts are derived by applying appropriate coordinate transformations.

  19. Derivatives in energy project finance

    International Nuclear Information System (INIS)

    Spencer, Lloyd

    1999-01-01

    This chapter focuses on risk management of merchant power generation projects and describes project finance as balancing risk and reward over time. The historical background to risk management is traced, and the case for derivatives in energy project finance is put forward with the hedging of forward output, and forwards and power purchase agreements discussed. Current and prospective usage, and the implementation issues of market liquidity, margin calls, letters of credit, derivative counterparty credit risk, and accounting policy are considered. A detailed example of a gas-fired plant in the US is presented with details given of the distribution of project earnings before tax. Oil field operating cashflows are examined, with reserved flow models, leverage effects, and price hedging addressed

  20. Diagnostic radio labelled polysaccharide derivatives

    International Nuclear Information System (INIS)

    Milbrath, D.S.; Ferber, R.H.; Barnett, W.E.

    1982-01-01

    A radiopharmaceutical compound for diagnosing blood clots is claimed. It is the reaction product of a compound characterized by a water-soluble polysaccharide moiety having an average of at least 0.25 anionic group per monosaccharide unit, and at least one chelating group derived from the group consisting of amino acids, substituted cyclic acid anhydrides, and carbon disulfide; and a radioactive tracer metal compound selected from In-111, Tc-99m, Cr-51, Ga-68, and a reduced pertechnetate compound

  1. Derivation of Hamiltonians for accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Symon, K.R.

    1997-09-12

    In this report various forms of the Hamiltonian for particle motion in an accelerator will be derived. Except where noted, the treatment will apply generally to linear and circular accelerators, storage rings, and beamlines. The generic term accelerator will be used to refer to any of these devices. The author will use the usual accelerator coordinate system, which will be introduced first, along with a list of handy formulas. He then starts from the general Hamiltonian for a particle in an electromagnetic field, using the accelerator coordinate system, with time t as independent variable. He switches to a form more convenient for most purposes using the distance s along the reference orbit as independent variable. In section 2, formulas will be derived for the vector potentials that describe the various lattice components. In sections 3, 4, and 5, special forms of the Hamiltonian will be derived for transverse horizontal and vertical motion, for longitudinal motion, and for synchrobetatron coupling of horizontal and longitudinal motions. Hamiltonians will be expanded to fourth order in the variables.

  2. Financial Derivatives (Based on Two Supports Evaluation

    Directory of Open Access Journals (Sweden)

    Tiberiu Socaciu

    2016-07-01

    Full Text Available In this paper we build a PDE like Black-Scholes equation in hypothesis of a financial derivative that is dependent on two supports (usual is dependent only on one support, like amoption based on gold, when national currency has a great float.Keywords: Financial derivatives, derivatives evaluation, derivatives based on two supports, extended Itō like lemma.

  3. 12 CFR 403.4 - Derivative classification.

    Science.gov (United States)

    2010-01-01

    ... SAFEGUARDING OF NATIONAL SECURITY INFORMATION § 403.4 Derivative classification. (a) Use of derivative classification. (1) Unlike original classification which is an initial determination, derivative classification... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Derivative classification. 403.4 Section 403.4...

  4. Clearing and settlement of exchange traded derivatives

    OpenAIRE

    John McPartland

    2009-01-01

    Derivatives are a class of financial instruments that derive their value from some underlying commodity, security, index, or other asset. Futures and options are common forms of derivatives. This article explains how clearing and settlement systems for exchange traded derivatives work.

  5. Development trends of the international derivatives market

    OpenAIRE

    Motorniuk, U.; Terebukh, M.; Kharchuk, V.

    2016-01-01

    The factors forming international derivatives market trends are researched in this article. The history of the formation of the global derivatives market was analyzed, in particular, events which have led to the growth of the derivatives market. Global derivatives market has revealed major changes in its trends and witnessed the gradual transformation of its structure, observed in recent years. Global derivatives market has revealed major changes in its trends and witnessed the gradual transf...

  6. Iron and iron derived radicals

    International Nuclear Information System (INIS)

    Borg, D.C.; Schaich, K.M.

    1987-04-01

    We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fast! Think small! In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab

  7. Resorcinol derivatives from Ardisia maculosa.

    Science.gov (United States)

    Zheng, Ying; Wu, Feng-E

    2007-01-01

    Besides a series of known sterols and triterpenoids, a new resorcinol (1) and a known resorcinol (2) have been isolated from ethanol extract of Ardisia maculosa for the first time. The structures of these resorcinol derivatives were elucidated as 2-methyl-5-(Z-heptadec-8-enyl) resorcinol and 5-Z-heptadec-8-enyl) resorcinol by HRESI-MS, NMR ((1)H, (13)C, HSQC, HMBC) experiments. In our in vitro assay, compounds 1 and 2 showed no antimicrobial activities, however, compound 2 exhibited cytotoxity activity against human cancer cell line with GI(50) value of 2.14 x 10(- 4) mmol/ml.

  8. Pentafluorobenzene end-group as a versatile handle for para fluoro “click” functionalization of polythiophenes† †Electronic supplementary information (ESI) available: Experimental details, MALDI-TOF, 1H and 19F NMR, UV-visible spectroscopy, and photoluminescence spectroscopy results. See DOI: 10.1039/c6sc04427a Click here for additional data file.

    Science.gov (United States)

    Boufflet, Pierre; Casey, Abby; Xia, Yiren; Stavrinou, Paul N.

    2017-01-01

    A convenient method of introducing pentafluorobenzene (PFB) as a single end-group in polythiophene derivatives is reported via in situ quenching of the polymerization. We demonstrate that the PFB-group is a particularly useful end-group due to its ability to undergo fast nucleophilic aromatic substitutions. Using this molecular handle, we are able to quantitatively tether a variety of common nucleophiles to the polythiophene backbone. The mild conditions required for the reaction allows sensitive functional moieties, such as biotin or a cross-linkable trimethoxysilane, to be introduced as end-groups. The high yield enabled the formation of a diblock rod-coil polymer from equimolar reactants under transition metal-free conditions at room temperature. We further demonstrate that water soluble polythiophenes end-capped with PFB can be prepared via the hydrolysis of an ester precursor, and that such polymers are amenable to functionalization under aqueous conditions. PMID:28507677

  9. Topological Derivatives in Shape Optimization

    CERN Document Server

    Novotny, Antonio André

    2013-01-01

    The topological derivative is defined as the first term (correction) of the asymptotic expansion of a given shape functional with respect to a small parameter that measures the size of singular domain perturbations, such as holes, inclusions, defects, source-terms and cracks. Over the last decade, topological asymptotic analysis has become a broad, rich and fascinating research area from both theoretical and numerical standpoints. It has applications in many different fields such as shape and topology optimization, inverse problems, imaging processing and mechanical modeling including synthesis and/or optimal design of microstructures, sensitivity analysis in fracture mechanics and damage evolution modeling. Since there is no monograph on the subject at present, the authors provide here the first account of the theory which combines classical sensitivity analysis in shape optimization with asymptotic analysis by means of compound asymptotic expansions for elliptic boundary value problems. This book is intende...

  10. Antioxidant capacity of eugenol derivatives

    Directory of Open Access Journals (Sweden)

    María E. Hidalgo

    2009-01-01

    Full Text Available Toxicity and antioxidant capacity of eugenol derivatives (E2 = 2-Methoxy-4-[1-propenylphenyl]acetate, E3 = 4-Allyl-2-methoxyphenylacetate, E4 = 4-Allyl-2-methoxy-4-nitrophenol, E5 = 5-Allyl-3-nitrobenzene-1,2-diol, E6 = 4-Allyl-2-methoxy-5-nitrophenyl acetate were evaluated in order to determine the influence of the sustituents. E2-E6 were synthesized from eugenol (E1. E1 was extracted from cloves oil, and E2-E6 were obtained through acetylation and nitration reactions. Antioxidant capacity evaluated by DPPH (1, 1-Diphenyl-2-picrylhydrazil and ORAC fluorescein demonstrated that E1 and E5 have a higher capacity and the minor toxicity evaluated by red blood cells haemolysis and the Artemia saline test. In accordance with our results, the compound's (E1-E5 use in the pharmaceutical, cosmetic and or food industries could be suggested.

  11. Cytotoxicity study of pyrazole derivatives

    Directory of Open Access Journals (Sweden)

    Nusrat Binta Ahasan

    2007-06-01

    Full Text Available Pyrazolone heterocyclic compound, 3-methyl-1-phenyl-2-pyrazoline-5-one 2(a was synthesized by condensation reaction between ethyl acetoacetate and phenyl hydrazine and was converted into their corresponding heterocyclic derivatives 2(b to 2(f2 . Their cytotoxicity effects were measured by brine shrimp lethality bioassay. Among them the compounds 2(b , 2(f1 , and 2(f2 were highly active according to IC50 values 19.50, 19.50 and 20 ppm respectively. The rest of compounds 2(a , 2(c , 2(d1 , and 2(d2 having IC50 values 38, 33.50, 37.50, 36, 37.50 and 36 ppm in that order, were moderately active.

  12. Cytotoxicity study of pyrazole derivatives

    Directory of Open Access Journals (Sweden)

    Nusrat Binta Ahasan and Md. Rabiul Islam

    2007-12-01

    Full Text Available Pyrazolone heterocyclic compound, 3-methyl-1-phenyl-2-pyrazoline-5-one 2(a was synthesized by condensation reaction between ethyl acetoacetate and phenyl hydrazine and was converted into their corresponding heterocyclic derivatives 2(b to 2(f2. Their cytotoxicity effects were measured by brine shrimp lethality bioassay. Among them the compounds 2(b, 2(f1, and 2(f2 were highly active according to IC50 values 19.50, 19.50 and 20 ppm respectively. The rest of compounds 2(a, 2(c, 2(d1, and 2(d2 having IC50 values 38, 33.50, 37.50, 36, 37.50 and 36 ppm in that order, were moderately active.

  13. Silsesquioxane-derived ceramic fibres

    Science.gov (United States)

    Hurwitz, F. I.; Farmer, S. C.; Terepka, F. M.; Leonhardt, T. A.

    1991-01-01

    Fibers formed from blends of silsesquioxane polymers were characterized to study the pyrolytic conversion of these precursors to ceramics. The morphology of fibers pyrolyzed to 1400 C revealed primarily amorphous glasses whose conversion to beta-SiC is a function of both blend composition and pyrolysis conditions. Formation of beta-SiC crystallites within the glassy phase is favored by higher than stoichiometric C/Si ratios, while carbothermal reduction of Si-O bonds to form SiC with loss of SiO and CO occurs at higher methyl/phenylpropyl silsesquioxane (lower C/Si) ratios. As the carbothermal reduction is assumed to be diffusion controlled, the fibers can serve as model systems to gain understanding of the silsesquioxane pyrolysis behavior, and therefore are useful in the development of polysilsesquioxane-derived ceramic matrices and coatings as well.

  14. Radiation processing of polysaccharide derivatives

    International Nuclear Information System (INIS)

    Yoshii, Fumio

    2004-01-01

    Carboxymethylcellulose (CMC), carboxymethylstarch (CMS), carboxymethylchitin (CM-chitin) and carboxymethylchitosan (CM-chitosan) form gels when irradiated at paste-like condition. Bedsore prevention mat filled up CMC hydrogel crosslinked by irradiation at paste-like condition was practical applied as a health care products. It was found that CM-chitosan hydrogels have anti-microbial activity and effective as absorbents to remove metal ions. When crosslinked gel sheets of CM-chitin and CM-chitosan were immersed in copper (II) aqueous solution, absorption of Cu (II) were 161 mg/g and 172 mg/g, respectively. Radiation crosslinking of cellulose derivative such as hydroxypropyl methylcellulose phthalate, (HPMCP) kneaded with aqueous alkali solution and methanol was achieved with EB-irradiation at paste-like condition. The HPMCP gel absorbed organic solvents such as chloroform and pyridine. (author)

  15. Derived limits for surface contamination

    CERN Document Server

    Wrixon, A D; Linsley, G S; White, D F

    1979-01-01

    Derived limits (DLs) for surface contamination were first established for use in the nuclear energy industry where a wide variety of radionuclides is encountered. They were later used in factories, hospitals, and universities, where the radionuclides used are normally fewer in number, either known or readily identifiable, and often of low toxicity. In these situations the current limits are frequently over-restrictive. This report describes a reassessment of the values in the light of more recent information on the possible pathways of exposure and the dose equivalent limits given in ICRP Publication 26. The reassessment is prompted also by the introduction of SI units. The results of the reassessment are used to produce a classification of DLs for all radionuclides for active and inactive area surfaces and for skin.

  16. Derivation of the dipole map

    International Nuclear Information System (INIS)

    Ali, Halima; Punjabi, Alkesh; Boozer, Allen

    2004-01-01

    In our method of maps [Punjabi et al., Phy. Rev. Lett. 69, 3322 (1992), and Punjabi et al., J. Plasma Phys. 52, 91 (1994)], symplectic maps are used to calculate the trajectories of magnetic field lines in divertor tokamaks. Effects of the magnetic perturbations are calculated using the low MN map [Ali et al., Phys. Plasmas 11, 1908 (2004)] and the dipole map [Punjabi et al., Phys. Plasmas 10, 3992 (2003)]. The dipole map is used to calculate the effects of externally located current carrying coils on the trajectories of the field lines, the stochastic layer, the magnetic footprint, and the heat load distribution on the collector plates in divertor tokamaks [Punjabi et al., Phys. Plasmas 10, 3992 (2003)]. Symplectic maps are general, efficient, and preserve and respect the Hamiltonian nature of the dynamics. In this brief communication, a rigorous mathematical derivation of the dipole map is given

  17. Landslide in claystone derived soil

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, A M

    1979-07-01

    This article describes a landslide that occured in the Pittsburgh area in a soil deposit derived from the Pittsburgh Redbed Claystone when a cut was made at the toe. (The Pittsburgh Redbed Claystone is the parent of much of the soil material involved in the Pittsburgh area and occurs about mid way between the base of Pittsburgh Coal and the top of the Upper Freepost Coal). The topography before the slide was known and the geometry of the slide mass was established. Slope stability analysis indicated that the landslide could have been predicted using effective stress-shear-strength parameters of s of 12 to 13 and c is 0, where s is angle of shearing resistance and c is cohesion intercept in terms of effective stresses.

  18. THE SPECIFICITY OF KERATEINE DERIVATIVES.

    Science.gov (United States)

    Pillemer, L; Ecker, E E; Martiensen, E W

    1939-09-30

    Carboxymethyl, alpha-carboxyethyl-, alpha-carboxy-n-propyl-, alpha-carboxyisopropyl-, alpha-carboxy-n-butyl, alpha-carboxyisobutyl, alpha-carboxyamyl-, benzyl-, and beta-phenylethylkeratemes were prepared from the parent protein, reduced keratin or kerateine. Chemical analysis disclosed that the various compounds differed in their isoelectric points and solubilities depending on the nature of the substituent group introduced. In general, it was found that in so far as could be determined, nearly all of the available sulfhydryl groups were substituted, while no detectable substitution of the free amino groups of the proteins occurred. The results of the serologic studies revealed that the kerateine derivatives acquired a new immunologie character dependent on the nature of the introduced determinant group. Inhibition tests confirmed the results obtained. Evidence was also produced to show that the grouping See PDF for structure may play a rôle in some of the reactions observed.

  19. Penetratin and derivatives acting as antifungal agents

    NARCIS (Netherlands)

    Masman, Marcelo F.; Rodriguez, Ana M.; Raimondi, Marcela; Zacchino, Susana A.; Luiten, Paul G. M.; Somlai, Csaba; Kortvelyesi, Tamas; Penke, Botond; Enriz, Ricardo D.

    The synthesis, in vitro evaluation, and conformational study of RQIKTWFQNRRMKWKK-NH(2) (penetratin) and related derivatives acting as antifungal agents are reported. Penetratin and some of its derivatives displayed antifungal activity against the human opportunistic pathogenic standardized ATCC

  20. Nature of the basic financial derivatives

    OpenAIRE

    Kats, Svetlana

    2014-01-01

    The article reveals the essence of basic derivatives. Studied by various authors approaches to defining derivatives and their definitions in the legislation and proposed his own definition of the most appropriate for use in accounting practice.

  1. fq-Derivations of G-Algebra

    Directory of Open Access Journals (Sweden)

    Deena Al-Kadi

    2016-01-01

    Full Text Available We introduce the notion of fq-derivation as a new derivation of G-algebra. For an endomorphism map f of any G-algebra X, we show that at least one fq-derivation of X exists. Moreover, for such a map, we show that a self-map dqf of X is fq-derivation of X if X is an associative medial G-algebra. For a medial G-algebra X, dqf is fq-derivation of X if dqf is an outside fq-derivation of X. Finally, we show that if f is the identity endomorphism of X then the composition of two fq-derivations of X is a fq-derivation. Moreover, we give a condition to get a commutative composition.

  2. Polymer-Derived Ceramic Fibers

    Science.gov (United States)

    Ichikawa, Hiroshi

    2016-07-01

    SiC-based ceramic fibers are derived from polycarbosilane or polymetallocarbosilane precursors and are classified into three groups according to their chemical composition, oxygen content, and C/Si atomic ratio. The first-generation fibers are Si-C-O (Nicalon) fibers and Si-Ti-C-O (Tyranno Lox M) fibers. Both fibers contain more than 10-wt% oxygen owing to oxidation during curing and lead to degradation in strength at temperatures exceeding 1,300°C. The maximum use temperature is 1,100°C. The second-generation fibers are SiC (Hi-Nicalon) fibers and Si-Zr-C-O (Tyranno ZMI) fibers. The oxygen content of these fibers is reduced to less than 1 wt% by electron beam irradiation curing in He. The thermal stability of these fibers is improved (they are stable up to 1,500°C), but their creep resistance is limited to a maximum of 1,150°C because their C/Si atomic ratio results in excess carbon. The third-generation fibers are stoichiometric SiC fibers, i.e., Hi-Nicalon Type S (hereafter Type S), Tyranno SA, and Sylramic™ fibers. They exhibit improved thermal stability and creep resistance up to 1,400°C. Stoichiometric SiC fibers meet many of the requirements for the use of ceramic matrix composites for high-temperature structural application. SiBN3C fibers derived from polyborosilazane also show promise for structural applications, remain in the amorphous state up to 1,800°C, and have good high-temperature creep resistance.

  3. 40 CFR 721.1820 - Bisphenol derivative.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Bisphenol derivative. 721.1820 Section... Substances § 721.1820 Bisphenol derivative. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as bisphenol derivative (PMN No. P-92-509) is...

  4. 45 CFR 601.5 - Derivative classification.

    Science.gov (United States)

    2010-10-01

    ... CLASSIFICATION AND DECLASSIFICATION OF NATIONAL SECURITY INFORMATION § 601.5 Derivative classification. Distinct... 45 Public Welfare 3 2010-10-01 2010-10-01 false Derivative classification. 601.5 Section 601.5... classification guide, need not possess original classification authority. (a) If a person who applies derivative...

  5. 5 CFR 1312.7 - Derivative classification.

    Science.gov (United States)

    2010-01-01

    ..., DOWNGRADING, DECLASSIFICATION AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION Classification and Declassification of National Security Information § 1312.7 Derivative classification. A derivative classification... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Derivative classification. 1312.7 Section...

  6. 6 CFR 7.26 - Derivative classification.

    Science.gov (United States)

    2010-01-01

    ... 6 Domestic Security 1 2010-01-01 2010-01-01 false Derivative classification. 7.26 Section 7.26 Domestic Security DEPARTMENT OF HOMELAND SECURITY, OFFICE OF THE SECRETARY CLASSIFIED NATIONAL SECURITY INFORMATION Classified Information § 7.26 Derivative classification. (a) Derivative classification is defined...

  7. 22 CFR 9.6 - Derivative classification.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Derivative classification. 9.6 Section 9.6 Foreign Relations DEPARTMENT OF STATE GENERAL SECURITY INFORMATION REGULATIONS § 9.6 Derivative classification. (a) Definition. Derivative classification is the incorporating, paraphrasing, restating or...

  8. Quantum derivatives and the Schroedinger equation

    International Nuclear Information System (INIS)

    Ben Adda, Faycal; Cresson, Jacky

    2004-01-01

    We define a scale derivative for non-differentiable functions. It is constructed via quantum derivatives which take into account non-differentiability and the existence of a minimal resolution for mean representation. This justify heuristic computations made by Nottale in scale-relativity. In particular, the Schroedinger equation is derived via the scale-relativity principle and Newton's fundamental equation of dynamics

  9. 12 CFR 563.172 - Financial derivatives.

    Science.gov (United States)

    2010-01-01

    ... underlying assets, indices, or reference rates. The most common types of financial derivatives are futures, forward commitments, options, and swaps. A mortgage derivative security, such as a collateralized mortgage... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Financial derivatives. 563.172 Section 563.172...

  10. Regio-Regular Oligo and Poly(3-hexyl thiophene): Precise Structural Markers from the Vibrational Spectra of Oligomer Single Crystals.

    KAUST Repository

    Brambilla, Luigi; Tommasini, Matteo; Botiz, Ioan; Rahimi, Khosrow; Agumba, John O.; Stingelin, Natalie; Zerbi, Giuseppe

    2014-01-01

    , namely, amorphous, semicrystalline, polycrystalline and single crystal. We have based our analysis on the spectra of the (3HT)8 single crystal (whose structure has been determined by selected area electron diffraction) taken as reference

  11. Regio-Regular Oligo and Poly(3-hexyl thiophene): Precise Structural Markers from the Vibrational Spectra of Oligomer Single Crystals.

    KAUST Repository

    Brambilla, Luigi

    2014-10-14

    © 2014 American Chemical Society. In this work, we report a comparative analysis of the infrared and Raman spectra of octa(3-hexylthiophene) (3HT)8, trideca(3-hexylthiophene) (3HT)13, and poly(3-hexylthiophene) P3HT recorded in various phases, namely, amorphous, semicrystalline, polycrystalline and single crystal. We have based our analysis on the spectra of the (3HT)8 single crystal (whose structure has been determined by selected area electron diffraction) taken as reference and on the results of DFT calculations and molecular vibrational dynamics. New and precise spectroscopic markers of the molecular structures show the existence of three phases, namely: hairy (phase 1), ordered (phase 2), and disordered/amorphous (phase 3). Conceptually, the identified markers can be used for the molecular structure analysis of other similar systems.

  12. Deriving the bond pricing equation

    Directory of Open Access Journals (Sweden)

    Kožul Nataša

    2014-01-01

    Full Text Available Given the recent focus on Eurozone debt crisis and the credit rating downgrade not only of US debt, but that of other countries and many UK major banking institutions, this paper aims to explain the concept of bond yield, its different measures and bond pricing equation. Yields on capital market instruments are rarely quoted on the same basis, which makes direct comparison between different as investment choices impossible. Some debt instruments are quoted on discount basis, whilst coupon-bearing ones accrue interest differently, offer different compounding opportunities, have different coupon payment frequencies, and manage non-business day maturity dates differently. Moreover, rules governing debt vary across countries, markets and currencies, making yield calculation and comparison a rather complex issue. Thus, some fundamental concepts applicable to debt instrument yield measurement, with focus on bond equation, are presented here. In addition, bond equation expressed in annuity form and used to apply Newton-Raphson algorithm to derive true bond yield is also shown.

  13. Classical gravity with higher derivatives

    International Nuclear Information System (INIS)

    Stelle, K.S.

    1978-01-01

    Inclusion of the four-derivative terms ∫Rsub(μν) Rsup(μν)(-g)sup(1/2) and ∫R 2 (-g)sup(1/2) into the gravitational action gives a class of effectively multimass models of gravity. In addition to the usual massless excitations of the field, there are now, for general amounts of the two new terms, massive spin-two and massive scalar excitations, with a total of eight degrees of freedom. The massive spin-two part of the field has negative energy. Specific ration of the two new terms give models with either the massive tensor or the massive scalar missing, with correspondingly fewer degrees of freedom. The static, linearized solutions of the field equations are combinations of Newtonian and Yukawa potentials. Owing to the Yukawa form of the corrections, observational evidence sets only very weak restrictions on the new masses. The acceptable static metric solutions in the full nonlinear theory are regular at the origin. The dynamical content of the linearized field is analyzed by reducing the fourth-order field equations to separated second-order equations, related by coupling to external sources in a fixed ratio. This analysis is carried out into the various helicity components using the transverse-traceless decomposition of the metric. (author)

  14. The estimation of derived limits

    International Nuclear Information System (INIS)

    Harrison, N.T.; Bryant, P.M.; Clarke, R.H.; Morley, F.

    1979-08-01

    In practical radiation protection, it is often necessary to calculate limits of intake of radionuclides associated with various quantities; such limits are needed, for example, to assess the adequacy of the control of environmental contamination. In publication 26 of the International Commission on Radiological Protection (ICRP), these limits, when related to the basic limits of dose-equivalent by a defined model, are referred to as Derived Limits (DLs). In the present report the principles to be adopted by the Board in calculating DLs to be recommended for general application within the United Kingdom are outlined. DLs will be recommended for a wide range of radionuclides and for circumstances relevant to the workplace, and, more frequently, the general environment. The latter will include DLs in foodstuffs and associated environmental materials, such as soil and grass, and DLs for discharges from stacks. DLs will be related to dose equivalents for workers or members of the public for stochastic or non-stochastic effects as appropriate. Consideration will be given to relevant data on radiosensitivity, metabolism and dosimetry for children and to the physicochemical forms of radionuclides. (author)

  15. Option Derivatives in Electricity Hedging

    Directory of Open Access Journals (Sweden)

    P. Pavlátka

    2010-01-01

    Full Text Available Despite the high volatility of electricity prices, there is still little demand for electricity power options, and the liquidity on the power exchanges of these power derivatives is quite low. One of the reasons is the uncertainty about how to evaluate these electricity options and about finding the right fair value of this product. Hedging of electricity is associated mainly with products such as futures and forwards. However, due to new trends in electricity trading and hedging, it is also useful to think more about options and the principles for working with them in hedging various portfolio positions and counterparties. We can quite often encounter a situation when we need to have a perfect hedge for our customer’s (end user consuming electricity portfolio, or we have to evaluate the volumetric risk (inability of a customer to predict consumption, which is very similar to selling options. Now comes the moment to compare the effects of using options or futures to hedge these open positions. From a practical viewpoint, the Black-Scholes prices appear to be the best available and the simplest method for evaluating option premiums, but there are some limitations that we have to consider.

  16. 21 CFR 184.1685 - Rennet (animal-derived) and chymosin preparation (fermentation-derived).

    Science.gov (United States)

    2010-04-01

    ... (fermentation-derived). 184.1685 Section 184.1685 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... (animal-derived) and chymosin preparation (fermentation-derived). (a)(1) Rennet and bovine rennet are... clear solution containing the active enzyme chymosin (E.C. 3.4.23.4). It is derived, via fermentation...

  17. Drug Nanoparticle Formulation Using Ascorbic Acid Derivatives

    Directory of Open Access Journals (Sweden)

    Kunikazu Moribe

    2011-01-01

    Full Text Available Drug nanoparticle formulation using ascorbic acid derivatives and its therapeutic uses have recently been introduced. Hydrophilic ascorbic acid derivatives such as ascorbyl glycoside have been used not only as antioxidants but also as food and pharmaceutical excipients. In addition to drug solubilization, drug nanoparticle formation was observed using ascorbyl glycoside. Hydrophobic ascorbic acid derivatives such as ascorbyl mono- and di-n-alkyl fatty acid derivatives are used either as drugs or carrier components. Ascorbyl n-alkyl fatty acid derivatives have been formulated as antioxidants or anticancer drugs for nanoparticle formulations such as micelles, microemulsions, and liposomes. ASC-P vesicles called aspasomes are submicron-sized particles that can encapsulate hydrophilic drugs. Several transdermal and injectable formulations of ascorbyl n-alkyl fatty acid derivatives were used, including ascorbyl palmitate.

  18. Perturbative reduction of derivative order in EFT

    Science.gov (United States)

    Glavan, Dražen

    2018-02-01

    Higher derivative corrections are ubiquitous in effective field theories, which seemingly introduces new degrees of freedom at successive orders. This is actually an artefact of the implicit local derivative expansion defining effective field theories. We argue that higher derivative corrections that introduce additional degrees of freedom should be removed and their effects captured either by lower derivative corrections, or special combinations of higher derivative corrections not propagating extra degrees of freedom. Three methods adapted for this task are examined and field redefinitions are found to be most appropriate. First order higher derivative corrections in a scalar tensor theory are removed by field redefinition and it is found that their effects are captured by a subset of Horndeski theories. A case is made for restricting the effective field theory expansions in principle to only terms not introducing additional degrees of freedom.

  19. Weather Derivatives – Origin, Types and Application

    Directory of Open Access Journals (Sweden)

    Piotr Binkowski

    2008-01-01

    Full Text Available The number of companies that are exposed to the revenues loss risk caused by weather variability is still increasing. The businesses that are mostly exposed to weather risk are following: energy, agriculture, constructions and transport. That situation has initiated dynamic growth of weather derivatives markets as well as the awareness of the weather risk among the market participants. Presently, the weather derivatives markets evaluate rapidly in all the mature economies: USA, Asia and Europe. Constructing weather derivatives relies on qu- antifying climate factors in the form of indexes, what is quite simple task, more difficultly can be gathering precise historical data of required climate factors. Taking into consideration so far development of derivatives especially the financial derivatives based on different types of indexes financial market has at disposal wide range of different types of proved derivatives (futures, forward, options, swaps, which can be successfully utilised on the weather-driven markets both for hedging weather risk and speculating.

  20. Derivative pricing based on local utility maximization

    OpenAIRE

    Jan Kallsen

    2002-01-01

    This paper discusses a new approach to contingent claim valuation in general incomplete market models. We determine the neutral derivative price which occurs if investors maximize their local utility and if derivative demand and supply are balanced. We also introduce the sensitivity process of a contingent claim. This process quantifies the reliability of the neutral derivative price and it can be used to construct price bounds. Moreover, it allows to calibrate market models in order to be co...

  1. Chromatic Derivatives, Chromatic Expansions and Associated Spaces

    OpenAIRE

    Ignjatovic, Aleksandar

    2009-01-01

    This paper presents the basic properties of chromatic derivatives and chromatic expansions and provides an appropriate motivation for introducing these notions. Chromatic derivatives are special, numerically robust linear differential operators which correspond to certain families of orthogonal polynomials. Chromatic expansions are series of the corresponding special functions, which possess the best features of both the Taylor and the Shannon expansions. This makes chromatic derivatives and ...

  2. Quantile driven identification of structural derivatives

    OpenAIRE

    Andrew Chesher

    2001-01-01

    Conditions are derived under which there is local nonparametric identification of derivatives of structural equations in nonlinear triangular simultaneous equations systems. The attack on this problem is via conditional quantile functions and exploits local quantile independence conditions. The identification conditions include local analogues of the order and rank conditions familiar in the analysis of linear simultaneous equations models. The objects whose identification is sought are deriv...

  3. Isotope-labelled folic acid derivatives

    International Nuclear Information System (INIS)

    Lewin, N.; Wong, E.T.

    1976-01-01

    The suggestion deals with the production of folic acid derivatives suitable as indicators or tracers for analyses of serum folates. These folic acid derivatives contain folic acid which is bound by one or both carboxyl groups to the amino nitrogen of compounds such as, e.g., tyramine, glycyl tyrosine, tyrosine, or the methyl ester of tyrosine. The derivative obtained can be substituted by a gamma emitter, e.g. the iodine isotope I 125. The radioactive derivative is used in the method for the competitive protein bonding to determine endogenic folates in the serum. (UWI) [de

  4. Superstability for Generalized Module Left Derivations and Generalized Module Derivations on a Banach Module (I

    Directory of Open Access Journals (Sweden)

    Rassias JM

    2009-01-01

    Full Text Available We discuss the superstability of generalized module left derivations and generalized module derivations on a Banach module. Let be a Banach algebra and a Banach -module, and . The mappings , and are defined and it is proved that if (resp., is dominated by then is a generalized (resp., linear module- left derivation and is a (resp., linear module- left derivation. It is also shown that if (resp., is dominated by then is a generalized (resp., linear module- derivation and is a (resp., linear module- derivation.

  5. Derivative analyticity relations and asymptotic energies

    International Nuclear Information System (INIS)

    Fischer, J.

    1976-01-01

    On the basis of general principles of the S-matrix theory theorems are derived showing that derivative analyticity relations analogous to those of Bronzen, Kane and Sukhatme hold at asymptotic energies if the high-energy limits of certain physical quantities exist

  6. 28 CFR 17.26 - Derivative classification.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Derivative classification. 17.26 Section 17.26 Judicial Administration DEPARTMENT OF JUSTICE CLASSIFIED NATIONAL SECURITY INFORMATION AND ACCESS TO CLASSIFIED INFORMATION Classified Information § 17.26 Derivative classification. (a) Persons...

  7. 5 CFR 2500.5 - Derivative classification.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Derivative classification. 2500.5 Section 2500.5 Administrative Personnel OFFICE OF ADMINISTRATION, EXECUTIVE OFFICE OF THE PRESIDENT INFORMATION SECURITY REGULATION § 2500.5 Derivative classification. The Office of Administration serves only as the...

  8. Derivative Securities and Financial Crisis in Romania

    OpenAIRE

    Gogoncea Ramona

    2012-01-01

    This paper aims to investigate the impact of the global financial crisis on the young Romanian market of derivative securities. It also describes the recent developments within Romanian capital market, in general, with focus on innovation in the field of derivative products.

  9. 46 CFR 503.55 - Derivative classification.

    Science.gov (United States)

    2010-10-01

    ... Security Program § 503.55 Derivative classification. (a) In accordance with Part 2 of Executive Order 12958 and directives of the Information Security Oversight Office, the incorporation, paraphrasing... 46 Shipping 9 2010-10-01 2010-10-01 false Derivative classification. 503.55 Section 503.55...

  10. Synthesis and Cytotoxicity of Novel Hexahydrothienocycloheptapyridazinone Derivatives

    Directory of Open Access Journals (Sweden)

    Irene Marchesi

    2009-09-01

    Full Text Available Designed as a new group of tricyclic molecules containing the thienocycloheptapyridazinone ring system, a number of 2N-substituted-hexahydrothienocycloheptapyridazinone derivatives were synthesized and their biological activity evaluated. Among the synthesized compounds, derivatives 7d and 7h were found to possess cytotoxic activity against non-small cell lung cancer and central nervous system cancer cell lines, respectively.

  11. "Nonmorphological Derivations" and the Four Main English ...

    African Journals Online (AJOL)

    This article addresses the problem of "nonmorphological derivations" in English and its consequences for pedagogical lexicography, i.e. learner's dictionaries. The term "nonmorphological derivation" refers to cases such as sun — solar, moon — lunar, cat — feline, and in general to all cases where instead of, or in addition ...

  12. Mesogenic benzothiazole derivatives with methoxy substituents

    Indian Academy of Sciences (India)

    Unknown

    2003-10-11

    Oct 11, 2003 ... literature. Barbera et al14 have synthesized 2-pyr- azoline derivatives and also studied the optical,. NLO and mesogenic properties of such materials. Highly polar thiophene-based liquid crystals have also been reported15 in the literature. However, fused ring heterocyclic derivatives which are two conden-.

  13. Deriving force field parameters for coordination complexes

    DEFF Research Database (Denmark)

    Norrby, Per-Ola; Brandt, Peter

    2001-01-01

    The process of deriving molecular mechanics force fields for coordination complexes is outlined. Force field basics are introduced with an emphasis on special requirements for metal complexes. The review is then focused on how to set up the initial model, define the target, refine the parameters......, and validate the final force field, Alternatives to force field derivation are discussed briefly....

  14. Weyl and Marchaud Derivatives: A Forgotten History

    Directory of Open Access Journals (Sweden)

    Fausto Ferrari

    2018-01-01

    Full Text Available In this paper, we recall the contribution given by Hermann Weyl and André Marchaud to the notion of fractional derivative. In addition, we discuss some relationships between the fractional Laplace operator and Marchaud derivative in the perspective to generalize these objects to different fields of the mathematics.

  15. Weyl and Marchaud derivatives: a forgotten history

    OpenAIRE

    Ferrari, Fausto

    2017-01-01

    In this paper, we recall the contribution given by Hermann Weyl and André Marchaud to the notion of fractional derivative. In addition, we discuss some relationships between the fractional Laplace operator and Marchaud derivative in the perspective to generalize these objects to different fields of the mathematics.

  16. New uracil derivatives and their biological activity

    International Nuclear Information System (INIS)

    Hudecova, D.; Striganova, J.; Chovanec, P.; Uher, M.

    1998-01-01

    Present study is concentrated to the research of antimicrobial activity of some derivatives of the uracil and 1,3-dimethyluracyl. The antimicrobial effects of these compounds have been tested on various strains of bacteria, yeasts, and filamentous fungi. The highest antimicrobial effects were found with dithiocarbamato-derivatives, which were effective against pathogenic and non-pathogenic bacteria (IC 50 = 7-25 μg cm -3 ), yeasts (IC 50 = 9-60 μg cm -3 ) and filamentous fungi.The most sensitive fungus to dithiocarbamato-derivatives was Botritis cinerea. It seems to be apparent that the presence of the -NH-C(S)-S- group in molecules of derivatives of uracil and and 1,3-dimethyluracyl influencing the incorporation rate [ 14 ]-adenine and 14 ]-leucine into the biomolecules and also markedly inhibits oxygen consumption (IC 50 = 58 μg cm -3 ). The same derivative demonstrated no mutagenic activity. (authors)

  17. Generalized Fractional Derivative Anisotropic Viscoelastic Characterization

    Directory of Open Access Journals (Sweden)

    Harry H. Hilton

    2012-01-01

    Full Text Available Isotropic linear and nonlinear fractional derivative constitutive relations are formulated and examined in terms of many parameter generalized Kelvin models and are analytically extended to cover general anisotropic homogeneous or non-homogeneous as well as functionally graded viscoelastic material behavior. Equivalent integral constitutive relations, which are computationally more powerful, are derived from fractional differential ones and the associated anisotropic temperature-moisture-degree-of-cure shift functions and reduced times are established. Approximate Fourier transform inversions for fractional derivative relations are formulated and their accuracy is evaluated. The efficacy of integer and fractional derivative constitutive relations is compared and the preferential use of either characterization in analyzing isotropic and anisotropic real materials must be examined on a case-by-case basis. Approximate protocols for curve fitting analytical fractional derivative results to experimental data are formulated and evaluated.

  18. Risk management, derivatives and shariah compliance

    Science.gov (United States)

    Bacha, Obiyathulla Ismath

    2013-04-01

    Despite the impressive growth of Islamic Banking and Finance (IBF), a number of weaknesses remain. The most important of this is perhaps the lack of shariah compliant risk management tools. While the risk sharing philosophy of Islamic Finance requires the acceptance of risk to justify returns, the shariah also requires adherents to avoid unnecessary risk-maysir. The requirement to avoid maysir is in essence a call for the prudent management of risk. Contemporary risk management revolves around financial engineering, the building blocks of which are financial derivatives. Despite the proven efficacy of derivatives in the management of risk in the conventional space, shariah scholars appear to be suspicious and uneasy with their use in IBF. Some have imposed outright prohibition of their use. This paper re-examines the issue of contemporary derivative instruments and shariah compliance. The shariah compatibility of derivatives is shown in a number of ways. First, by way of qualitative evaluation of whether derivatives can be made to comply with the key prohibitions of the sharia. Second, by way of comparing the payoff profiles of derivatives with risk sharing finance and Bai Salam contracts. Finally, the equivalence between shariah compliant derivatives like the IPRS and Islamic FX Currency Forwards with conventional ones is presented.

  19. On derived groups of division rings II

    International Nuclear Information System (INIS)

    Mahdavi Hezavehi, M.; Akbari Feyzaabaadi, S.; Mehraabaadi, M.; Hajie Abolhassan, H.

    1995-05-01

    Let D be a division ring with centre F and denote by D' the derived group (commutator subgroup) of D * = D - {0}. It is shown that if each element of D' is algebraic over F, then D is algebraic over F. It is also proved that each finite separable extension of F in D is of the form F(c) for some element c in the derived group D'. Using these results, it is shown that if each element of the derived group D' is of bounded degree over F, then D is finite dimensional over F. (author). 5 refs

  20. Derivation of GFDM Based on OFDM Principles

    Energy Technology Data Exchange (ETDEWEB)

    Hussein Moradi; Behrouz Farhang-Boroujeny

    2015-06-01

    This paper starts with discussing the principle based on which the celebrated orthogonal frequency division multiplexing (OFDM) signals are constructed. It then extends the same principle to construct the newly introduced generalized frequency division multiplexing (GFDM) signals. This novel derivation sheds light on some interesting properties of GFDM. In particular, our derivation seamlessly leads to an implementation of GFDM transmitter which has significantly lower complexity than what has been reported so far. Our derivation also facilitates a trivial understanding of how GFDM (similar to OFDM) can be applied in MIMO channels.

  1. Mechanism of Platinum Derivatives Induced Kidney Injury

    Directory of Open Access Journals (Sweden)

    Feifei YAN

    2015-09-01

    Full Text Available Platinum derivatives are the most widely used chemotherapeutic agents to treat solid tumors including ovarian, head and neck, and testicular germ cell tumors, lung cancer, and colorectal cancer. Two major problems exist, however, in the clinic use of platinum derivatives. One is the development of tumor resistance to the drug during therapy, leading to treatment failure. The other is the drug’s toxicity such as the cisplatin’s nephrotoxicity, which limits the dose that can be administered. This paper describes the mechanism of platinum derivatives induced kidney injury.

  2. Bulk heterojunction organic photovoltaic based on polythiophene-polyelectrolyte carbon nanotube composites

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Reyes, M. [Instituto de Investigacion en Comunicacion Optica, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, San Luis Potosi (Mexico); Lopez-Sandoval, R. [Advanced Materials Department, IPICYT, Camino a la Presa San Jose 2055, Col. Lomas 4a. Seccion, San Luis Potosi 78216 (Mexico); Liu, J.; Carroll, D.L. [Center for Nanotechnology and Molecular Materials, Wake Forest University, Winston-Salem, NC (United States)

    2007-09-22

    It is shown that carbon nanotubes can be used to enhance carrier mobility for efficient removal of the charges in thin film polymer-conjugated/fullerene photovoltaic devices. The fabricated photovoltaic devices consist of poly(3-octylthiophene) (P3OT) polymer blended with undoped multiwalled carbon nanotubes (MWNTs) and carbon nanotubes doped with nitrogen (CNx-MWNTs). Nanophase formation and dispersion problems associated with the use of carbon nanotubes in polymer devices were addressed through the generation of functional groups and electrostatic attaching of the polyelectrolyte poly(dimethyldiallylamine) chloride (PDDA) in both MWNTs and CNx-MWNT systems. The resultant nanophase was highly dispersed allowing for excellent bulk heterojunction formation. Our results indicate that CNx-MWNTs enhance the efficiency of P3OT solar cells in comparison with MWNTs. (author)

  3. SERS active systems of water-soluble polythiophene and plasmonic nanoparticles: preparation and optical properties

    Czech Academy of Sciences Publication Activity Database

    Kazim, Samrana; Pfleger, Jiří; Halašová, Klára; Procházka, M.; Bondarev, D.; Vohlídal, J.

    2011-01-01

    Roč. 55, č. 2 (2011), 23905_1-23905_6 ISSN 1286-0042. [International Symposium on Flexible Organic Electronics /3./. Ouranoupolis, 06.07.2010-09.07.2010] R&D Projects: GA AV ČR KAN100500652; GA MŠk 7E10040; GA ČR GAP208/10/0941 Institutional research plan: CEZ:AV0Z40500505 Keywords : nanocomposite * SERS * .pi.-conjugated polymer s Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.771, year: 2011

  4. Polythiophene-based conjugated polyelectrolyte: Optical properties and association behavior in solution

    Czech Academy of Sciences Publication Activity Database

    Urbánek, P.; di Martino, A.; Gladyš, S.; Kuřitka, I.; Minařík, A.; Pavlova, Ewa; Bondarev, D.

    2015-01-01

    Roč. 202, April (2015), s. 16-24 ISSN 0379-6779 R&D Projects: GA TA ČR(CZ) TE01020118; GA ČR GAP108/12/1143 Institutional support: RVO:61389013 Keywords : polyelectrolyte * conjugated polymer * UV–vis spectroscopy Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.299, year: 2015

  5. The x-ray structure and MNDO calculations of a-terthienyl: a model for polythiophenes

    NARCIS (Netherlands)

    Bolhuis, van F.; Wynberg, H.; Havinga, E.E.; Meijer, E.W.; Staring, E.G.J.

    1989-01-01

    The x-ray structure of a-terthienyl reveals 2 identical, crystallog.-independent mols. in the unit cell. Neighboring thiophene moieties in a-terthienyl are placed antiparallel, while the mol. is almost planar, with torsional angles between the rings of about 6-9 Deg. MNDO calcns. of a-terthienyl

  6. Electrostimulated Release of Neutral Drugs from Polythiophene Nanoparticles: Smart Regulation of Drug-Polymer Interactions.

    Science.gov (United States)

    Puiggalí-Jou, Anna; Micheletti, Paolo; Estrany, Francesc; Del Valle, Luis J; Alemán, Carlos

    2017-09-01

    Poly(3,4-ethylenedioxythiophene) (PEDOT) nanoparticles are loaded with curcumin and piperine by in situ emulsion polymerization using dodecyl benzene sulfonic acid both as a stabilizer and a doping agent. The loaded drugs affect the morphology, size, and colloidal stability of the nanoparticles. Furthermore, kinetics studies of nonstimulated drug release have evidenced that polymer···drug interactions are stronger for curcumin than for piperine. This observation suggests that drug delivery systems based on combination of the former drug with PEDOT are much appropriated to show an externally tailored release profile. This is demonstrated by comparing the release profiles obtained in presence and absence of electrical stimulus. Results indicate that controlled and time-programmed release of curcumin is achieved in a physiological medium by applying a negative voltage of -1.25 V to loaded PEDOT nanoparticles. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Low-temperature side-chain cleavage and decarboxylation of polythiophene esters by acid catalysis

    DEFF Research Database (Denmark)

    Søndergaard, Roar; Norrman, Kion; Krebs, Frederik C

    2012-01-01

    Solubility switching of polymers is very useful in thin layer processing of conjugated polymers, as it allows for multilayer processing and increases the stability of the polymer. Acid catalyzed thermocleavage of ester groups from thiophene polymers carrying primary, secondary, and tertiary subst...

  8. Control of polythiophene film microstructure and charge carrier dynamics through crystallization temperature

    KAUST Repository

    Marsh, Hilary S.; Reid, Obadiah G.; Barnes, George; Heeney, Martin; Stingelin, Natalie; Rumbles, Garry

    2014-01-01

    The microstructure of neat conjugated polymers is crucial in determining the ultimate morphology and photovoltaic performance of polymer/fullerene blends, yet until recently, little work has focused on controlling the former. Here, we demonstrate that both the long-range order along the (100)-direction and the lamellar crystal thickness along the (001)-direction in neat poly(3-hexylthiophene) (P3HT) and poly[(3,3″-didecyl[2,2′:5′, 2″-terthiophene]-5,5″-diyl)] (PTTT-10) thin films can be manipulated by varying crystallization temperature. Changes in crystalline domain size impact the yield and dynamics of photogenerated charge carriers. Time-resolved microwave conductivity measurements show that neat polymer films composed of larger crystalline domains have longer photoconductance lifetimes and charge carrier yield decreases with increasing crystallite size for P3HT. Our results suggest that the classical polymer science description of temperature-dependent crystallization of polymers from solution can be used to understand thin-film formation in neat conjugated polymers, and hence, should be considered when discussing the structural evolution of organic bulk heterojunctions. © 2014 Wiley Periodicals, Inc.

  9. Exciton diffusion length in some thermocleavable polythiophenes by the surface photovoltage method

    DEFF Research Database (Denmark)

    Tousek, J.; Touskova, J.; Remes, Z.

    2012-01-01

    property is that P3MHOCT can serve as a precursor which, after thermal annealing, converts into more rigid and insoluble P3CT and further thermal treatment produces native unsubstituted PT. Ellipsometric measurement yielded data on the thickness of the spin coated layers; absorption coefficients were...... be ascribed to the increase of the crystalline fraction. The highest diffusion length was found in P3CT polymer but its large resistivity represents a disadvantage in application in solar cells. Taking into account just these parameters, relatively low resistivity together with quite high diffusion length (13...

  10. Control of polythiophene film microstructure and charge carrier dynamics through crystallization temperature

    KAUST Repository

    Marsh, Hilary S.

    2014-03-22

    The microstructure of neat conjugated polymers is crucial in determining the ultimate morphology and photovoltaic performance of polymer/fullerene blends, yet until recently, little work has focused on controlling the former. Here, we demonstrate that both the long-range order along the (100)-direction and the lamellar crystal thickness along the (001)-direction in neat poly(3-hexylthiophene) (P3HT) and poly[(3,3″-didecyl[2,2′:5′, 2″-terthiophene]-5,5″-diyl)] (PTTT-10) thin films can be manipulated by varying crystallization temperature. Changes in crystalline domain size impact the yield and dynamics of photogenerated charge carriers. Time-resolved microwave conductivity measurements show that neat polymer films composed of larger crystalline domains have longer photoconductance lifetimes and charge carrier yield decreases with increasing crystallite size for P3HT. Our results suggest that the classical polymer science description of temperature-dependent crystallization of polymers from solution can be used to understand thin-film formation in neat conjugated polymers, and hence, should be considered when discussing the structural evolution of organic bulk heterojunctions. © 2014 Wiley Periodicals, Inc.

  11. MANGROVE-DERIVED NUTRIENTS AND CORAL REEFS

    Science.gov (United States)

    Understanding the consequences of the declining global cover of mangroves due to anthropogenic disturbance necessitates consideration of how mangrove-derived nutrients contribute to threatened coral reef systems. We sampled potential sources of organic matter and a suite of sessi...

  12. Preparation of 7-substituted ginkgolide derivatives

    DEFF Research Database (Denmark)

    Vogensen, Stine Byskov; Strømgaard, Kristian; Shindou, Hideo

    2003-01-01

    alpha-fluoro ginkgolide B was equipotent to ginkgolide B underlining the critical importance of the 7-position of ginkgolides for PAF receptor activity. Herein we describe the synthesis of a series of ginkgolide B derivatives with modifications at the 7-position and the pharmacological evaluation...... of these derivatives as assayed by cloned PAF receptors. In two cases nucleophilic attack on a 7beta-O-triflate ginkgolide B did not lead to the expected products, but gave rise to two unprecedented ginkgolide derivatives, one with a novel rearranged skeleton. Furthermore, standard reduction of 7alpha-azido ginkgolide......-chloro ginkgolide B, the most potent nonaromatic ginkgolide derivative described to date with a K(i) value of 110 nM....

  13. Patient-Derived Antibody Targets Tumor Cells

    Science.gov (United States)

    An NCI Cancer Currents blog on an antibody derived from patients that killed tumor cells in cell lines of several cancer types and slowed tumor growth in mouse models of brain and lung cancer without evidence of side effects.

  14. Overtone spectroscopy of some benzaldehyde derivatives

    Indian Academy of Sciences (India)

    internuclear distances for the aryl CH bond in the different molecules. The small variation observed in these distances is ..... [6] D N Singh, Vibrational spectra and force fields for some benzaldehyde derivatives, Ph.D. Thesis. (Banaras Hindu ...

  15. SYNTHESIS OF SUBSTITUTED FLAVONE DERIVATIVES AS ...

    African Journals Online (AJOL)

    Preferred Customer

    Flavone (2-phenylchromone) derivatives are naturally occurring heterocyclic compound belongs to the flavanoid group. It showed significant role in pharmaceutical effects [1] including leishmanicidal activity, oviposter stimulant phytoalexins, anti-HIV, vasodilator, antiviral, anti- oxidants, bactericidal, DNA cleavage, ...

  16. Synthesis of Lipophilic Guanine N-9 Derivatives

    DEFF Research Database (Denmark)

    Wamberg, Michael C; Pedersen, Pernille L; Löffler, Philipp M G

    2017-01-01

    the synthesis of five new guanine-N9 derivatives bearing alkyl chains with different attachment chemistries, exploiting a synthesis pathway that allows a flexible choice of hydrophobic anchor moiety. In this study, these guanine derivatives were functionalized with C10 chains for insertion into decanoic acid...... bilayer structures, in which both alkyl chain length and attachment chemistry determined their interaction with the membrane. Incubation of these guanine conjugates, as solids, with a decanoic acid vesicle suspension, showed that ether- and triazole-linked C10 anchors yielded an increased partitioning...... of the guanine derivative into the membranous phase compared to directly N-9-linked saturated alkyl anchors. Decanoic acid vesicle membranes could be loaded with up to 5.5 mol % guanine derivative, a 6-fold increase over previous limits. Thus, anchor chemistries exhibiting favorable interactions with a bilayer...

  17. Particle production in higher derivative theory

    Indian Academy of Sciences (India)

    Lemaitre–Robertson–Walker cosmological model during the early stages of the universe is analysed in the framework of higher derivative theory. The universe has been considered as an open thermodynamic system where particle production ...

  18. Langmuir-Blodgett Films of Graphene Derivatives

    DEFF Research Database (Denmark)

    Petersen, Søren Vermehren

    The work presented in this PhD thesis can be divided into two main categories: 1) Syn-thesis and Langmuir-Blodgett assembly of graphene derivatives and 2) Application and characterization of graphene derivatives as an interface material in molecular electron-ics. While the first category could...... be divided further, the synthesis and Langmuir-Blodgett results are intertwined in such a way that it would be more confusing to pre-sent them separately. The Langmuir-Blodgett deposition also played a crucial, but more isolated, part in the investigation of graphene derivatives as interface material....... Solution processable graphene in the form of chemically derived graphene has been synthesized through the modified Hummers method with subsequent reduction into reduced graphene oxide with hydrazine. The completeness of oxidation, the effect of the refinement steps and the reduction of the graphene oxide...

  19. 76 FR 4751 - Position Limits for Derivatives

    Science.gov (United States)

    2011-01-26

    ... saleable by long traders at its market value in normal cash marketing channels at the derivative contract's... Association, Futures Industry Association, GDF Suez Energy, Morgan Stanley, and NextEra Energy Power Marketing...

  20. Second derivative parallel block backward differentiation type ...

    African Journals Online (AJOL)

    Second derivative parallel block backward differentiation type formulas for Stiff ODEs. ... Log in or Register to get access to full text downloads. ... and the methods are inherently parallel and can be distributed over parallel processors. They are ...

  1. Novel hydroquinone derivatives alleviate algesia, inflammation and ...

    African Journals Online (AJOL)

    derivatives were synthesized and their structures were confirmed by .... to water. The baseline rectal temperature of all mice was noted by inserting a lubricated digital thermometer ... (PDB) and the binding site residues of the receptors were ...

  2. Plant-derived nanostructures: types and applications

    Science.gov (United States)

    Plant-derived nanostructures and nanoparticles (NPs) have functional applications in numerous disciplines such as health care, food and feed, cosmetics, biomedical science, energy science, drug-gene delivery, environmental health, and so on. Consequently, it is imperative for res...

  3. Anodic selective functionalization of cyclic amine derivatives

    OpenAIRE

    Onomura, Osamu

    2012-01-01

    Anodic reactions are desirable methods from the viewpoint of Green Chemistry, since no toxic oxidants are necessary for the oxidation of organic molecules. This review introduces usefulness of anodic oxidation and successive reaction for selective functionalization of cyclic amine derivatives.

  4. Regional Ecological Corridors - MLCCS derived 2008

    Data.gov (United States)

    Minnesota Department of Natural Resources — Identification of potential ecological corridors between the MLCCS derived ecological patches (ear_eco08py3). This was generated using cost / distance analysis,...

  5. MEAN OF MEDIAN ABSOLUTE DERIVATION TECHNIQUE MEAN ...

    African Journals Online (AJOL)

    eobe

    development of mean of median absolute derivation technique based on the based on the based on .... of noise mean to estimate the speckle noise variance. Noise mean property ..... Foraging Optimization,” International Journal of. Advanced ...

  6. An alternative to the flutter derivatives

    DEFF Research Database (Denmark)

    Andersen, Michael Styrk; Brandt, Anders

    A new simplified framework to study flutter and assess the full scale flutter wind speed is suggested. The flutter instability problem is reduced from a problem involving 8 flutter derivatives to only 4 coefficients. With this method it is possible to estimate the self-excited forces with increased...... precision by using stability diagrams. Furthermore, the physical transparency of the aerodynamic damping and stiffness terms is increased because the development in vertical and torsional damping and stiffness is analysed instead of flutter derivatives....

  7. Higher-derivative Lee-Wick unification

    International Nuclear Information System (INIS)

    Carone, Christopher D.

    2009-01-01

    We consider gauge coupling unification in Lee-Wick extensions of the Standard Model that include higher-derivative quadratic terms beyond the minimally required set. We determine how the beta functions are modified when some Standard Model particles have two Lee-Wick partners. We show that gauge coupling unification can be achieved in such models without requiring the introduction of additional fields in the higher-derivative theory and we comment on possible ultraviolet completions.

  8. Financial derivatives in power marketing: The basics

    International Nuclear Information System (INIS)

    Ramesh, V.C.; Ghosh, K.

    1996-01-01

    With the ongoing changes in the power industry worldwide, electricity is beginning to be traded like other commodities. The use of financial derivative instruments in power markets is on the rise. The purpose of this paper is to explain the role of these derivatives in risk management which is vital for survival in the increasingly competitive industry. Starting with the familiar cash markets, the paper discusses the basics of futures, options, and swap markets as applied to electric energy trading

  9. Higher derivative regularization and chiral anomaly

    International Nuclear Information System (INIS)

    Nagahama, Yoshinori.

    1985-02-01

    A higher derivative regularization which automatically leads to the consistent chiral anomaly is analyzed in detail. It explicitly breaks all the local gauge symmetry but preserves global chiral symmetry and leads to the chirally symmetric consistent anomaly. This regularization thus clarifies the physics content contained in the consistent anomaly. We also briefly comment on the application of this higher derivative regularization to massless QED. (author)

  10. Complexes of salicylic acid and its derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Tel' zhenskaya, P N; Shvarts, E M [AN Latvijskoj SSR, Riga. Inst. Neorganicheskoj Khimii

    1977-01-01

    A generalization and systematization have been made of literature data on complexing of various elements, including beryllium, cadmium, boron, indium, rare-earth elements, actinides, and transition elements with salicylic acid and it derivatives (amino-, nitro- and halosalicylic acids). The effect of the position and nature of the substitute, in the case of salicylic acid derivatives, on the complexing process is discussed. Certain physicochemical properties of the complexes under consideration are described along with data indicative of their stability.

  11. On computing Laplace's coefficients and their derivatives.

    Science.gov (United States)

    Gerasimov, I. A.; Vinnikov, E. L.

    The algorithm of computing Laplace's coefficients and their derivatives is proposed with application of recurrent relations. The A.G.M.-method is used for the calculation of values L0(0), L0(1). The FORTRAN-program corresponding to the algorithm is given. The precision control was provided with numerical integrating by Simpsons method. The behavior of Laplace's coefficients and their third derivatives whith varying indices K, n for fixed values of the α-parameter is presented graphically.

  12. Weather Derivatives – Origin, Types and Application

    OpenAIRE

    Piotr Binkowski

    2008-01-01

    The number of companies that are exposed to the revenues loss risk caused by weather variability is still increasing. The businesses that are mostly exposed to weather risk are following: energy, agriculture, constructions and transport. That situation has initiated dynamic growth of weather derivatives markets as well as the awareness of the weather risk among the market participants. Presently, the weather derivatives markets evaluate rapidly in all the mature economies: USA, Asia and Europ...

  13. A note on derivations in semiprime rings

    Directory of Open Access Journals (Sweden)

    Joso Vukman

    2005-01-01

    Full Text Available We prove in this note the following result. Let n>1 be an integer and let R be an n!-torsion-free semiprime ring with identity element. Suppose that there exists an additive mapping D:R→R such that D(xn=∑j=1nxn−jD(xxj−1 is fulfilled for all x∈R. In this case, D is a derivation. This research is motivated by the work of Bridges and Bergen (1984. Throughout, R will represent an associative ring with center Z(R. Given an integer n>1, a ring R is said to be n-torsion-free if for x∈R, nx=0 implies that x=0. Recall that a ring R is prime if for a,b∈R, aRb=(0 implies that either a=0 or b=0, and is semiprime in case aRa=(0 implies that a=0. An additive mapping D:R→R is called a derivation if D(xy=D(xy+xD(y holds for all pairs x,y∈R and is called a Jordan derivation in case D(x2=D(xx+xD(x is fulfilled for all x∈R. Every derivation is a Jordan derivation. The converse is in general not true. A classical result of Herstein (1957 asserts that any Jordan derivation on a prime ring with characteristic different from two is a derivation. A brief proof of Herstein's result can be found in 1988 by Brešar and Vukman. Cusack (1975 generalized Herstein's result to 2-torsion-free semiprime rings (see also Brešar (1988 for an alternative proof. For some other results concerning derivations on prime and semiprime rings, we refer to Brešar (1989, Vukman (2005, Vukman and Kosi-Ulbl (2005.

  14. Introduction of Credit Derivatives and Valuation of Credit Default Swap

    OpenAIRE

    Han, Lu

    2006-01-01

    The credit derivative market was established at the beginning of the 1990s since the emergence of credit derivatives fits the rapid development of the whole derivatives market. However, compare to other derivative market, this market is still small and incomplete. As with other derivatives, credit derivatives can be used to either take more risk or hedge it, hence various credit derivatives instruments are accepted and widely used by market participants such as banks, insurance companies, etc...

  15. Multiscale analysis of the CMB temperature derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Marcos-Caballero, A.; Martínez-González, E.; Vielva, P., E-mail: marcos@ifca.unican.es, E-mail: martinez@ifca.unican.es, E-mail: vielva@ifca.unican.es [Instituto de Física de Cantabria, CSIC-Universidad de Cantabria, Avda. de los Castros s/n, 39005 Santander, Spain. (Spain)

    2017-02-01

    We study the Planck CMB temperature at different scales through its derivatives up to second order, which allows one to characterize the local shape and isotropy of the field. The problem of having an incomplete sky in the calculation and statistical characterization of the derivatives is addressed in the paper. The analysis confirms the existence of a low variance in the CMB at large scales, which is also noticeable in the derivatives. Moreover, deviations from the standard model in the gradient, curvature and the eccentricity tensor are studied in terms of extreme values on the data. As it is expected, the Cold Spot is detected as one of the most prominent peaks in terms of curvature, but additionally, when the information of the temperature and its Laplacian are combined, another feature with similar probability at the scale of 10{sup o} is also observed. However, the p -value of these two deviations increase above the 6% when they are referred to the variance calculated from the theoretical fiducial model, indicating that these deviations can be associated to the low variance anomaly. Finally, an estimator of the directional anisotropy for spinorial quantities is introduced, which is applied to the spinors derived from the field derivatives. An anisotropic direction whose probability is <1% is detected in the eccentricity tensor.

  16. Structure Activity Relationship of Brevenal Hydrazide Derivatives

    Directory of Open Access Journals (Sweden)

    Allan Goodman

    2014-03-01

    Full Text Available Brevenal is a ladder frame polyether produced by the dinoflagellate Karenia brevis. This organism is also responsible for the production of the neurotoxic compounds known as brevetoxins. Ingestion or inhalation of the brevetoxins leads to adverse effects such as gastrointestinal maladies and bronchoconstriction. Brevenal shows antagonistic behavior to the brevetoxins and shows beneficial attributes when administered alone. For example, in an asthmatic sheep model, brevenal has been shown to increase tracheal mucosal velocity, an attribute which has led to its development as a potential treatment for Cystic Fibrosis. The mechanism of action of brevenal is poorly understood and the exact binding site has not been elucidated. In an attempt to further understand the mechanism of action of brevenal and potentially develop a second generation drug candidate, a series of brevenal derivatives were prepared through modification of the aldehyde moiety. These derivatives include aliphatic, aromatic and heteroaromatic hydrazide derivatives. The brevenal derivatives were tested using in vitro synaptosome binding assays to determine the ability of the compounds to displace brevetoxin and brevenal from their native receptors. A sheep inhalation model was used to determine if instillation of the brevenal derivatives resulted in bronchoconstriction. Only small modifications were tolerated, with larger moieties leading to loss of affinity for the brevenal receptor and bronchoconstriction in the sheep model.

  17. PROCEDURES FOR THE DERIVATION OF EQUILIBRIUM ...

    Science.gov (United States)

    This equilibrium partitioning sediment benchmark (ESB) document describes procedures to derive concentrations for 32 nonionic organic chemicals in sediment which are protective of the presence of freshwater and marine benthic organisms. The equilibrium partitioning (EqP) approach was chosen because it accounts for the varying biological availability of chemicals in different sediments and allows for the incorporation of the appropriate biological effects concentration. This provides for the derivation of benchmarks that are causally linked to the specific chemical, applicable across sediments, and appropriately protective of benthic organisms. EqP can be used to calculate ESBs for any toxicity endpoint for which there are water-only toxicity data; it is not limited to any single effect endpoint. For the purposes of this document, ESBs for 32 nonionic organic chemicals, including several low molecular weight aliphatic and aromatic compounds, pesticides, and phthalates, were derived using Final Chronic Values (FCV) from Water Quality Criteria (WQC) or Secondary Chronic Values (SCV) derived from existing toxicological data using the Great Lakes Water Quality Initiative (GLI) or narcosis theory approaches. These values are intended to be the concentration of each chemical in water that is protective of the presence of aquatic life. For nonionic organic chemicals demonstrating a narcotic mode of action, ESBs derived using the GLI approach specifically for fres

  18. Studies on Synthesis of Some Novel Heterocyclic Azlactone Derivatives and Imidazolinone Derivatives and their Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    Rakesh N. Mistry

    2005-01-01

    Full Text Available p - Methyl benzoic acid on reaction with phosphorus pentachloride gives p - methyl benzoyl chloride derivative which on condensation with glycine gives p - methyl benzoyl glycine derivative. Now, this p - methyl benzoyl glycine derivative on condensation with various substituted aldehydes gives corresponding substituted 4 - [aryl methylidine] - 2 - [p - methyl phenyl] - oxazole - 5 - one derivatives [1(a-j]. Further, these derivatives [1(a-j] on condensation with 4 , 4’ - diamino diphenyl sulphone gives corresponding substituted imidazolinone - dibenzsulphone derivatives [2(a-j], on condensation with 4 , 4’ - diamino diphenyl methane gives corresponding substituted imidazolinone - dibenzmethane derivatives [3(a-j], on condensation with 4,4’- diamino benzanilide gives corresponding substituted imidazolinone - benzanilide derivatives [4(a-j] and on condensation with 2 - amino pyridine gives corresponding substituted imidazolinone - pyridine derivatives [5(a-j] respectively. Structure elucidation of synthesised compounds has been made on the basis of elemental analysis, I.R. spectral studies and 1H N.M.R. spectral studies. The antimicrobial activity of the synthesised compounds has been studied against the cultures “Staphylococcus aureus”, “Escherichia coli” and “Candela albicans”.

  19. Adaptive synchronization of the complex dynamical network with non-derivative and derivative coupling

    Energy Technology Data Exchange (ETDEWEB)

    Xu Yuhua, E-mail: yuhuaxu2004@163.co [College of Information Science and Technology, Donghua University, Shanghai 201620 (China) and Department of Maths, Yunyang Teachers' College, Hubei 442000 (China); Zhou Wuneng, E-mail: wnzhou@163.co [College of Information Science and Technology, Donghua University, Shanghai 201620 (China); Fang Jian' an [College of Information Science and Technology, Donghua University, Shanghai 201620 (China); Sun Wen [School of Mathematics and Information, Yangtze University, Hubei Jingzhou 434023 (China)

    2010-04-05

    This Letter investigates the synchronization of a general complex dynamical network with non-derivative and derivative coupling. Based on LaSalle's invariance principle, adaptive synchronization criteria are obtained. Analytical result shows that under the designed adaptive controllers, a general complex dynamical network with non-derivative and derivative coupling can asymptotically synchronize to a given trajectory, and several useful criteria for synchronization are given. What is more, the coupling matrix is not assumed to be symmetric or irreducible. Finally, simulations results show the method is effective.

  20. 32 CFR 2400.14 - Use of derivative classification.

    Science.gov (United States)

    2010-07-01

    ... SECURITY PROGRAM Derivative Classification § 2400.14 Use of derivative classification. (a) Derivative... 32 National Defense 6 2010-07-01 2010-07-01 false Use of derivative classification. 2400.14... person who applies derivative classification markings believes that the paraphrasing, restating, or...

  1. Contact allergy to isoeugenol and its derivatives

    DEFF Research Database (Denmark)

    Tanaka, Susumu; Royds, C; Buckley, Christopher D

    2004-01-01

    A total of 2261 (808 male, 1453 female) consecutive patients attending contact dermatitis clinics were patch tested to isoeugenol and its derivatives listed in the EU Inventory of Fragrance Ingredients. Positive reactions were found to isoeugenol in 40, transisoeugenol in 40, isoeugenyl acetate...... and 15/16 of those to isoeugenyl phenylacetate but in none of those 6 positive to isoeugenyl methyl ether and in neither of those 2 positive to benzyl isoeugenyl ether. Concomitant contact allergy between isoeugenol and its derivatives may occur through chemical cross-reactivity or local skin metabolism...... of the derivatives. It is more commonly observed with the esters rather than the ethers. Isoeugenyl acetate has been proposed as an alternative to isoeugenol, but there is a high degree of concomitant reactivity with isoeugenol....

  2. Funding climate adaptation strategies with climate derivatives

    Directory of Open Access Journals (Sweden)

    L. Richard Little

    2015-01-01

    Full Text Available Climate adaptation requires large capital investments that could be provided not only by traditional sources like governments and banks, but also by derivatives markets. Such markets would allow two parties with different tolerances and expectations about climate risks to transact for their mutual benefit and, in so doing, finance climate adaptation. Here we calculate the price of a derivative called a European put option, based on future sea surface temperature (SST in Tasmania, Australia, with an 18 °C strike threshold. This price represents a quantifiable indicator of climate risk, and forms the basis for aquaculture industries exposed to the risk of higher SST to finance adaptation strategies through the sale of derivative contracts. Such contracts provide a real incentive to parties with different climate outlooks, or risk exposure to take a market assessment of climate change.

  3. Structure-activity relationships of bumetanide derivatives

    DEFF Research Database (Denmark)

    Pedersen, Kasper Lykke; Töllner, Kathrin; Römermann, Kerstin

    2015-01-01

    of diuretics such as bumetanide. Bumetanide was discovered by screening ∼5000 3-amino-5-sulfamoylbenzoic acid derivatives, long before NKCC2 was identified in the kidney. Therefore, structure-activity studies on effects of bumetanide derivatives on NKCC2 are not available. EXPERIMENTAL APPROACH: In this study......, the effect of a series of diuretically active bumetanide derivatives was investigated on human NKCC2 variant A (hNKCC2A) expressed in Xenopus laevis oocytes. KEY RESULTS: Bumetanide blocked hNKCC2A transport with an IC50 of 4 μM. There was good correlation between the diuretic potency of bumetanide and its...... of the structural requirements that determine relative potency of loop diuretics on human NKCC2 splice variants, and may lead to the discovery of novel high-ceiling diuretics....

  4. FINANCIAL DERIVATIVES - MEANINGS BEYOND SUBPRIME CRISIS STIGMA

    Directory of Open Access Journals (Sweden)

    FELICIA RAMONA BIRĂU

    2012-12-01

    Full Text Available Derivatives are designed as complex financial instruments and their main aim is to manage the risk associated with the underlying asset, in order to ensure against fluctuations in value, or to profit from periods of inactivity, instability or decline. In recent years financial derivatives have experienced a fulminant development and also they have been perceived as an effective lever of the modern economy. The subprime crisis was triggered by a quite significant financial infrastructure glitch, which coalesced around certain factors influence, such as : highly permissive regulation of financial markets, speculative bubbles, underperforming risk management, liquidity injections and structural imbalances. Despite the fact that is a innovative segment and quite difficult affordable as understanding level of the operation mechanisms, financial derivatives were only the tool triggering this global dimension crisis.

  5. Deriving Trading Rules Using Gene Expression Programming

    Directory of Open Access Journals (Sweden)

    Adrian VISOIU

    2011-01-01

    Full Text Available This paper presents how buy and sell trading rules are generated using gene expression programming with special setup. Market concepts are presented and market analysis is discussed with emphasis on technical analysis and quantitative methods. The use of genetic algorithms in deriving trading rules is presented. Gene expression programming is applied in a form where multiple types of operators and operands are used. This gives birth to multiple gene contexts and references between genes in order to keep the linear structure of the gene expression programming chromosome. The setup of multiple gene contexts is presented. The case study shows how to use the proposed gene setup to derive trading rules encoded by Boolean expressions, using a dataset with the reference exchange rates between the Euro and the Romanian leu. The conclusions highlight the positive results obtained in deriving useful trading rules.

  6. Additive derivations on algebras of measurable operators

    International Nuclear Information System (INIS)

    Ayupov, Sh.A.; Kudaybergenov, K.K.

    2009-08-01

    Given a von Neumann algebra M we introduce the so-called central extension mix(M) of M. We show that mix(M) is a *-subalgebra in the algebra LS(M) of all locally measurable operators with respect to M, and this algebra coincides with LS(M) if and only if M does not admit type II direct summands. We prove that if M is a properly infinite von Neumann algebra then every additive derivation on the algebra mix(M) is inner. This implies that on the algebra LS(M), where M is a type I ∞ or a type III von Neumann algebra, all additive derivations are inner derivations. (author)

  7. 5-Nitroimidazole Derivatives and their Antimicrobial Activity

    International Nuclear Information System (INIS)

    Khan, K.M.; Salar, U.; Yousuf, S.; Naz, F.

    2016-01-01

    5-Nitroimidazole derivatives 2-8 were synthesized from secnidazole. The syntheses were accomplished in two steps which start from the oxidation of secnidazole to the secnidazolone 1. Secnidazolone 1 was converted into its hydrazone derivative 2-8 by treating with different substituted acid hydrazide. Compounds 2-8 were evaluated for their antimicrobial activity against Gram-positive and Gram-negative bacteria, compounds 3 and 4 showed the significant activity against Staphylococcus epidermidis, however, compound 2 showed good inhibitions against Corynebacterium diphtheria when compared with the standard. Compound 3 showed good inhibitory potential against tested Gram-negative bacterial strains i.e. Enterobacter aerogene, Escherichia coli, Salmonella typhi, Salmonella paratyphi A, Shigella flexeneri and Vibrio choleriae. All synthetic derivatives were also tested against eight fungal stains, however, they were weekly active against Aspergillus flavus and Candida albican. The synthesized compounds were characterized by different spectroscopy techniques. (author)

  8. Structural studies of 4-aminoantipyrine derivatives

    Science.gov (United States)

    Cunha, Silvio; Oliveira, Shana M.; Rodrigues, Manoel T.; Bastos, Rodrigo M.; Ferrari, Jailton; de Oliveira, Cecília M. A.; Kato, Lucília; Napolitano, Hamilton B.; Vencato, Ivo; Lariucci, Carlito

    2005-10-01

    Reaction of 4-aminoantipyrine with acetylacetone, ethyl acetoacetate, benzoyl isothiocyanate, phenyl isothiocyanate, maleic anhydride and methoxymethylene Meldrum's acid afforded a series of new antipyrine derivatives. The antibacterial activity of the synthesized compounds against Micrococcus luteus ATCC 9341, Staphilococcus aureus ATCC 29737, and Escherichia coli ATCC 8739 was evaluated and the minimal inhibitory concentration determined. Modest activity was found only to the maleamic acid obtained from the reaction of 4-aminoantipyrine and maleic anhydride. 1H NMR investigation of this maleamic acid showed that it is slowly converted to the corresponding toxic maleimide. The structures of three derivatives were determined by X-ray diffraction analysis.

  9. Ethanolamine derivatives of dysprosium and holmium

    International Nuclear Information System (INIS)

    Gharia, K.S.; Singh, M.; Mathur, S.; Sankhla, B.S.

    1981-01-01

    The preparation and properties of dysprosium and holmium derivatives of mono-, di- and tri-ethanolamine derivatives are described. Compounds of general formulae: Ln(OPrsup(i)) 2 (mea), Ln(OPrsup(i))(mea) 2 , Ln(mea) 3 , Ln(OPrsup(i))(dea), Ln 2 (dea) 3 , Ln(dea)(deaH) and Ln(tea) (where Ln = Dy or Ho and mea, dea and tea are the anions of respective ethanolamine) were obtained and characterized by elemental analysis and IR spectra. (author)

  10. Geometric derivation of the quantum speed limit

    International Nuclear Information System (INIS)

    Jones, Philip J.; Kok, Pieter

    2010-01-01

    The Mandelstam-Tamm and Margolus-Levitin inequalities play an important role in the study of quantum-mechanical processes in nature since they provide general limits on the speed of dynamical evolution. However, to date there has been only one derivation of the Margolus-Levitin inequality. In this paper, alternative geometric derivations for both inequalities are obtained from the statistical distance between quantum states. The inequalities are shown to hold for unitary evolution of pure and mixed states, and a counterexample to the inequalities is given for evolution described by completely positive trace-preserving maps. The counterexample shows that there is no quantum speed limit for nonunitary evolution.

  11. A 'simple' hybrid model for power derivatives

    International Nuclear Information System (INIS)

    Lyle, Matthew R.; Elliott, Robert J.

    2009-01-01

    This paper presents a method for valuing power derivatives using a supply-demand approach. Our method extends work in the field by incorporating randomness into the base load portion of the supply stack function and equating it with a noisy demand process. We obtain closed form solutions for European option prices written on average spot prices considering two different supply models: a mean-reverting model and a Markov chain model. The results are extensions of the classic Black-Scholes equation. The model provides a relatively simple approach to describe the complicated price behaviour observed in electricity spot markets and also allows for computationally efficient derivatives pricing. (author)

  12. Novel Aflatoxin Derivatives and Protein Conjugates

    Directory of Open Access Journals (Sweden)

    Reinhard Niessner

    2007-03-01

    Full Text Available Aflatoxins, a group of structurally related mycotoxins, are well known for their toxic and carcinogenic effects in humans and animals. Aflatoxin derivatives and protein conjugates are needed for diverse analytical applications. This work describes a reliable and fast synthesis of novel aflatoxin derivatives, purification by preparative HPLC and characterisation by ESI-MS and one- and two-dimensional NMR. Novel aflatoxin bovine serum albumin conjugates were prepared and characterised by UV absorption and MALDI-MS. These aflatoxin protein conjugates are potentially interesting as immunogens for the generation of aflatoxin selective antibodies with novel specificities.

  13. Derived limits and their practical applications

    International Nuclear Information System (INIS)

    Minarik, F.

    1982-01-01

    Attention is devoted to the approach and methodological procedure in determining derived limits for surface contamination with special regard to external exposure of hands, inhalation of resuspended activity, contamination of the skin and with regard to ingestion of radioactive material from the skin. In the practical part of the article, results are given of measuring contamination by radionuclides 134 Cs, 133 Cs and 60 Co, and the resulting annual equivalent dose rates and their comparison with derived air contamination in the sense of ICRP Publ. No. 30. (author)

  14. Development of chitosan derivatives with anhydride maleic

    International Nuclear Information System (INIS)

    Silva, Solranny C.C.C.; Braz, Elton Marks de A.; Brito, Carla Adriana R. de S.; Silva, Durcilene A. da; Junior, Luiz de S.S.; Silva Filho, Edson C. da

    2015-01-01

    Chitosan was chemically modified with maleic anhydride in ratios of 1/2, 1/5 and 1/10 in the absence of solvents. The obtained derivatives were characterized by elemental analysis, FTIR, thermal analysis (TGA / DTG) and XRD where it was possible to prove the chemical modification. Elemental analysis showed an increase of the relation C / N with the increasing of the proportion of anhydrides. The FTIR showed the incorporation of the anhydride in the biopolymer structure. The thermal stability of the derivatives was lower in comparison to the polysaccharide and by XRD the modified materials were less crystalline. (author)

  15. High ethanol producing derivatives of Thermoanaerobacter ethanolicus

    Science.gov (United States)

    Ljungdahl, L.G.; Carriera, L.H.

    1983-05-24

    Derivatives of the newly discovered microorganism Thermoanaerobacter ethanolicus which under anaerobic and thermophilic conditions continuously ferment substrates such as starch, cellobiose, glucose, xylose and other sugars to produce recoverable amounts of ethanol solving the problem of fermentations yielding low concentrations of ethanol using the parent strain of the microorganism Thermoanaerobacter ethanolicus are disclosed. These new derivatives are ethanol tolerant up to 10% (v/v) ethanol during fermentation. The process includes the use of an aqueous fermentation medium, containing the substrate at a substrate concentration greater than 1% (w/v).

  16. Derivation of Mayer Series from Canonical Ensemble

    International Nuclear Information System (INIS)

    Wang Xian-Zhi

    2016-01-01

    Mayer derived the Mayer series from both the canonical ensemble and the grand canonical ensemble by use of the cluster expansion method. In 2002, we conjectured a recursion formula of the canonical partition function of a fluid (X.Z. Wang, Phys. Rev. E 66 (2002) 056102). In this paper we give a proof for this formula by developing an appropriate expansion of the integrand of the canonical partition function. We further derive the Mayer series solely from the canonical ensemble by use of this recursion formula. (paper)

  17. Derivation of Mayer Series from Canonical Ensemble

    Science.gov (United States)

    Wang, Xian-Zhi

    2016-02-01

    Mayer derived the Mayer series from both the canonical ensemble and the grand canonical ensemble by use of the cluster expansion method. In 2002, we conjectured a recursion formula of the canonical partition function of a fluid (X.Z. Wang, Phys. Rev. E 66 (2002) 056102). In this paper we give a proof for this formula by developing an appropriate expansion of the integrand of the canonical partition function. We further derive the Mayer series solely from the canonical ensemble by use of this recursion formula.

  18. Special relativity derived from spacetime magma.

    Science.gov (United States)

    Greensite, Fred

    2014-01-01

    We present a derivation of relativistic spacetime largely untethered from specific physical considerations, in constrast to the many physically-based derivations that have appeared in the last few decades. The argument proceeds from the inherent magma (groupoid) existing on the union of spacetime frame components [Formula: see text] and Euclidean [Formula: see text] which is consistent with an "inversion symmetry" constraint from which the Minkowski norm results. In this context, the latter is also characterized as one member of a class of "inverse norms" which play major roles with respect to various unital [Formula: see text]-algebras more generally.

  19. Special relativity derived from spacetime magma.

    Directory of Open Access Journals (Sweden)

    Fred Greensite

    Full Text Available We present a derivation of relativistic spacetime largely untethered from specific physical considerations, in constrast to the many physically-based derivations that have appeared in the last few decades. The argument proceeds from the inherent magma (groupoid existing on the union of spacetime frame components [Formula: see text] and Euclidean [Formula: see text] which is consistent with an "inversion symmetry" constraint from which the Minkowski norm results. In this context, the latter is also characterized as one member of a class of "inverse norms" which play major roles with respect to various unital [Formula: see text]-algebras more generally.

  20. Scale up of proteoliposome derived Cochleate production.

    Science.gov (United States)

    Zayas, Caridad; Bracho, Gustavo; Lastre, Miriam; González, Domingo; Gil, Danay; Acevedo, Reinaldo; del Campo, Judith; Taboada, Carlos; Solís, Rosa L; Barberá, Ramón; Pérez, Oliver

    2006-04-12

    Cochleate are highly stable structures with promising immunological features. Cochleate structures are usually obtaining from commercial lipids. Proteoliposome derived Cochleate are derived from an outer membrane vesicles of Neisseria meningitidis B. Previously, we obtained Cochleates using dialysis procedures. In order to increase the production process, we used a crossflow system (CFS) that allows easy scale up to obtain large batches in an aseptic environment. The raw material and solutions used in the production process are already approved for human application. This work demonstrates that CFS is very efficient process to obtain Cochleate structures with a yield of more than 80% and the immunogenicity comparable to that obtained by dialysis membrane.

  1. Urinary Derivations: Radiological Anatomy and Complications

    International Nuclear Information System (INIS)

    Rodriguez, A.; Escartin, I.; Zapater, C.; Riazuelo, G.; Canon, R.; Solanas, S.; Garcia de Jalon, A.

    2003-01-01

    Cystectomy with urine derivation is a common procedure in the treatment of transition cell carcinoma of the bladder. We present radiological findings (ultrasound scan, computerized tomography (CT) and urography) from the surgical reconstruction techniques most often performed by the Urology staff of our hospital as well as some of the complications which occur. The above-mentioned techniques are basically divided into two types: incontinent derivations, of which we highlight the Bicker-Wallace technique and continent ones. The latter can either be ortho topic, with urethral anastomosis (Hauptmann's technique), or heterotopic, with urine excretion through the anus (Mains II technique) or employing a self-catheter (Mainz I technique). (Author) 7 refs

  2. Derivation and characterization of a pig embryonic stem cell-derived exocrine pancreatic cell line

    Science.gov (United States)

    The establishment and initial characterization of a pig embryonic stem cell-derived pancreatic cell line, PICM-31, and a colony-cloned derivative cell line, PICM-31A, is described. The cell lines were propagated for several months at split ratios of 1:3 or 1:5 at each passage on STO feeder cells af...

  3. A class of constitutive relations with internal variable derivatives. Derivation from homogenization and initial value problem

    International Nuclear Information System (INIS)

    Andrieux, S.; Joussemet, M.; Lorentz, E.

    1996-01-01

    A general framework for deriving and using a class of constitutive laws incorporating spatial gradients of internal variables is presented. It uses two basic ingredients: a derivation of such models by homogenization techniques and a reformulation of the evolution equation at the scale of the whole structure. (orig.)

  4. 18 CFR 367.2440 - Account 244, Derivative instrument liabilities.

    Science.gov (United States)

    2010-04-01

    ..., Derivative instrument liabilities. This account must include the change in the fair value of all derivative instrument liabilities not designated as cash flow or fair value hedges. Account 426.5, Other deductions... the fair value of the derivative instrument. ...

  5. Optimal economic order quantity for buyer-distributor-vendor supply chain with backlogging derived without derivatives

    Science.gov (United States)

    Teng, Jinn-Tsair; Cárdenas-Barrón, Leopoldo Eduardo; Lou, Kuo-Ren; Wee, Hui Ming

    2013-05-01

    In this article, we first complement an inappropriate mathematical error on the total cost in the previously published paper by Chung and Wee [2007, 'Optimal the Economic Lot Size of a Three-stage Supply Chain With Backlogging Derived Without Derivatives', European Journal of Operational Research, 183, 933-943] related to buyer-distributor-vendor three-stage supply chain with backlogging derived without derivatives. Then, an arithmetic-geometric inequality method is proposed not only to simplify the algebraic method of completing prefect squares, but also to complement their shortcomings. In addition, we provide a closed-form solution to integral number of deliveries for the distributor and the vendor without using complex derivatives. Furthermore, our method can solve many cases in which their method cannot, because they did not consider that a squared root of a negative number does not exist. Finally, we use some numerical examples to show that our proposed optimal solution is cheaper to operate than theirs.

  6. Energy derivatives, experiences in derivative trading from the natural gas industry : back to basics

    International Nuclear Information System (INIS)

    Dittmer, G.; Coyle, T.

    1998-01-01

    Some basic facts regarding derivatives in the electric power industry were discussed based on experiences in the natural gas industry. Derivatives were described as financial instruments that have no value of their own but derive their value from other assets, such as commodities. Futures and Options are the two forms of derivatives. Electricity as a commodity was characterized, and a historical parallel was drawn between deregulation in the natural gas and electric power industry. Short term and long term factors impacting the market and market dynamics impacting derivatives were identified. The latter include: (1) volatility, (2) liquidity, (3) correlations, and (4) price discovery. In contrast to the natural gas market, the electricity market is considered as lacking liquidity and in need of moving farther along the maturity timeline. The question of natural gas/ electricity convergence was also addressed refs., tabs., figs

  7. Deriving simulators for hybrid Chi models

    NARCIS (Netherlands)

    Beek, van D.A.; Man, K.L.; Reniers, M.A.; Rooda, J.E.; Schiffelers, R.R.H.

    2006-01-01

    The hybrid Chi language is formalism for modeling, simulation and verification of hybrid systems. The formal semantics of hybrid Chi allows the definition of provably correct implementations for simulation, verification and realtime control. This paper discusses the principles of deriving an

  8. Unedoside derivatives in Nuxia and their biosynthesis

    DEFF Research Database (Denmark)

    Jensen, Søren Rosendal; Ravnkilde, Lene; Schripsema, Jan

    1998-01-01

    An investigation of two species of Nuxia showed that this genus is characterized by the presence of the eight-carbon iridoid glucoside unedoside and/or its derivatives. From N. floribunda unedoside, nuxioside (6-O-alpha-L-rhamnopyranosyl-unedoside) and 2 "-acetyl-3 "-cinnamoyl-nuxioside were...

  9. Significant exposures to isoeugenol derivatives in perfumes

    DEFF Research Database (Denmark)

    Rastogi, S.C.; Johansen, Jeanne Duus

    2008-01-01

    Background: Isoeugenol, an important fragrance allergen in consumers, has been restricted to 200 p.p.m. since 1998 according to guidelines issued by the fragrance industry. However, no decline in contact allergy to isoeugnol has been detected. It has been speculated that isoeugenol derivatives...

  10. Structural Studies of Some Binaphthyl Derivatives

    DEFF Research Database (Denmark)

    Thorup, Niels; Bjørnholm, T.; Bechgaard, K.

    1996-01-01

    Crystal structures of several 1,1'-binaphthyl derivatives have been determined. In particular compounds which at the 2,2' positions have either identical ethoxy groups or a closed bridged ether and furthermore have identical substitution at the 6,6' positions. The latter groups may be Br, CHO, CN...

  11. Generalized Jackknife Estimators of Weighted Average Derivatives

    DEFF Research Database (Denmark)

    Cattaneo, Matias D.; Crump, Richard K.; Jansson, Michael

    With the aim of improving the quality of asymptotic distributional approximations for nonlinear functionals of nonparametric estimators, this paper revisits the large-sample properties of an important member of that class, namely a kernel-based weighted average derivative estimator. Asymptotic...

  12. Synthesis and characterization of novel sulfonamides derivatives

    African Journals Online (AJOL)

    3Department of Chemistry, Comsat Institute of Information & Technology Riawind road. Lahore ... Newer sulfonamides and their derivatives has obtained great attention in pharmaceutical field in ... MS data was recorded on Finnigan MAT 112 mass ..... potent and orally active sulfonamide ETB selective antagonists. Bioorg.

  13. 17 CFR 200.506 - Derivative classification.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Derivative classification. 200.506 Section 200.506 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National Security...

  14. Fundamentals of futures, options, basis and derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Jones, D. [TD Securities Inc., Toronto, ON (Canada)

    1997-08-01

    Characteristic features of futures and options contracts, basis differentials and derivatives were defined and explained. A futures contract refers to an exchange-traded supply contract between a buyer and a seller where the buyer is obligated to take delivery and the seller is obligated to provide delivery of a fixed amount of a commodity at a predetermined price at a specified location. In contrast, an option contract gives the purchaser the right, but not the obligation, to buy or sell the underlying commodity at a certain price on or before an agreed date. Basis differential refers to the discount between two distinct delivery points to reflect the relative value of a commodity, such as natural gas, at those points. Advantages and disadvantages of futures and options contacts, the factors affecting options pricing, and basis differentials, and the methods of calculating basis differentials were described. The nature and intricacies of derivatives, their benefits, in particular their use as a tool for the effective management of the volatilities associated with the oil and gas industry were explained. Their shortcomings such as the high liquidity risk, were also described. Examples of derivative transactions were provided to illustrate the interrelationships of futures/options/derivatives, and their role in financial risk management.

  15. 32 CFR 2001.22 - Derivative classification.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Derivative classification. 2001.22 Section 2001.22 National Defense Other Regulations Relating to National Defense INFORMATION SECURITY OVERSIGHT OFFICE, NATIONAL ARCHIVES AND RECORDS ADMINISTRATION CLASSIFIED NATIONAL SECURITY INFORMATION...

  16. Interest Rate Derivative Pricing with Stochastic Volatility

    NARCIS (Netherlands)

    Chen, B.

    2012-01-01

    One purpose of exotic derivative pricing models is to enable financial institutions to quantify and manage their financial risk, arising from large books of portfolios. These portfolios consist of many non-standard exotic financial products. Risk is managed by means of the evaluation of sensitivity

  17. Microscopically derived free energy of dislocations

    NARCIS (Netherlands)

    Kooiman, M.; Hütter, M.; Geers, M.G.D.

    2015-01-01

    The dynamics of large amounts of dislocations is the governing mechanism in metal plasticity. The free energy of a continuous dislocation density profile plays a crucial role in the description of the dynamics of dislocations, as free energy derivatives act as the driving forces of dislocation

  18. Econometric Analysis of Financial Derivatives : An overview

    NARCIS (Netherlands)

    C-L. Chang (Chia-Lin); M.J. McAleer (Michael)

    2014-01-01

    markdownabstract__Abstract__ One of the fastest growing areas in empirical finance, and also one of the least rigorously analyzed, especially from a financial econometrics perspective, is the econometric analysis of financial derivatives, which are typically complicated and difficult to analyze.

  19. Econometric Analysis of Financial Derivatives: An Overview

    NARCIS (Netherlands)

    C-L. Chang (Chia-Lin); M.J. McAleer (Michael)

    2014-01-01

    markdownabstract__Abstract__ One of the fastest growing areas in empirical finance, and also one of the least rigorously analyzed, especially from a financial econometrics perspective, is the econometric analysis of financial derivatives, which are typically complicated and difficult to analyze.

  20. Nitration of Thiacalix[4]arene Derivatives

    Czech Academy of Sciences Publication Activity Database

    Lhoták, P.; Svoboda, J.; Stibor, I.; Sýkora, Jan

    2002-01-01

    Roč. 43, č. 41 (2002), s. 7413-7417 ISSN 0040-4039 R&D Projects: GA ČR GA104/00/1722 Keywords : derivatives * nitation of thiacalix[4]arene Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.357, year: 2002

  1. Deriving GENERIC from a generalized fluctuation symmetry

    NARCIS (Netherlands)

    Kraaij, R.; Lazarescu, A.; Maes, C.; Peletier, M.A.

    2018-01-01

    Much of the structure of macroscopic evolution equations for relaxation to equilibrium can be derived from symmetries in the dynamical fluctuations around the most typical trajectory. For example, detailed balance as expressed in terms of the Lagrangian for the path-space action leads to gradient

  2. Enabling quaternion derivatives: the generalized HR calculus

    Science.gov (United States)

    Xu, Dongpo; Jahanchahi, Cyrus; Took, Clive C.; Mandic, Danilo P.

    2015-01-01

    Quaternion derivatives exist only for a very restricted class of analytic (regular) functions; however, in many applications, functions of interest are real-valued and hence not analytic, a typical case being the standard real mean square error objective function. The recent HR calculus is a step forward and provides a way to calculate derivatives and gradients of both analytic and non-analytic functions of quaternion variables; however, the HR calculus can become cumbersome in complex optimization problems due to the lack of rigorous product and chain rules, a consequence of the non-commutativity of quaternion algebra. To address this issue, we introduce the generalized HR (GHR) derivatives which employ quaternion rotations in a general orthogonal system and provide the left- and right-hand versions of the quaternion derivative of general functions. The GHR calculus also solves the long-standing problems of product and chain rules, mean-value theorem and Taylor's theorem in the quaternion field. At the core of the proposed GHR calculus is quaternion rotation, which makes it possible to extend the principle to other functional calculi in non-commutative settings. Examples in statistical learning theory and adaptive signal processing support the analysis. PMID:26361555

  3. Initial value formulation of higher derivative gravity

    International Nuclear Information System (INIS)

    Noakes, D.R.

    1983-01-01

    The initial value problem is considered for the conformally coupled scalar field and higher derivative gravity, by expressing the equations of each theory in harmonic coordinates. For each theory it is shown that the (vacuum) equations can take the form of a diagonal hyperbolic system with constraints on the initial data. Consequently these theories possess well-posed initial value formulations

  4. Orchard navigation using derivative free Kalman filtering

    DEFF Research Database (Denmark)

    Hansen, Søren; Bayramoglu, Enis; Andersen, Jens Christian

    2011-01-01

    This paper describes the use of derivative free filters for mobile robot localization and navigation in an orchard. The localization algorithm fuses odometry and gyro measurements with line features representing the surrounding fruit trees of the orchard. The line features are created on basis of 2...

  5. Curcumin derivatives as HIV-1 protease inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Z.; Li, J.; Craik, C.S.; Ortiz de Montellano, P.R. [Univ. of California, San Francisco, CA (United States)

    1993-12-31

    Curcumin, a non-toxic natural compound from Curcuma longa, has been found to be an HIV-1 protease inhibitor. Some of its derivatives were synthesized and their inhibitory activity against the HIV-1 protease was tested. Curcumin analogues containing boron enhanced the inhibitory activity. At least of the the synthesized compounds irreversibly inhibits the HIV-1 protease.

  6. Genetic enrichment of cardiomyocytes derived from mouse ...

    African Journals Online (AJOL)

    Genetic enrichment of cardiomyocytes derived from mouse embryonic stem cells. WJ He, SC Li, LL Ye, H Liu, QW Wang, WD Han, XB Fu, ZL Chen. Abstract. Pluripotent embryonic stem cells (ESC) have the ability to differentiate into a variety of cell lineages in vitro, including cardiomyocytes. Successful applications of ...

  7. Cocktail : a tool for deriving correct programs

    NARCIS (Netherlands)

    Franssen, M.G.J.; Swart, de H.C.M.

    2004-01-01

    Cocktail is a tool for deriving correct programs from their specifications. The present version is powerful enough for educational purposes. The tool yields support for many sorted first order predicate logic, formulated in a pure type system with parametric constants (CPTS), as the specification

  8. A new pyrrolidone derivative from Pistacia chinensis

    Institute of Scientific and Technical Information of China (English)

    Jian Jun Liu; Chang An Geng; Xi Kui Liu

    2008-01-01

    A new N-phenyl-pyrrolidone derivative had been isolated from Pistacia chinesis Bunge. Its structure was elucidated as4-hydroxy-5-(2-oxo-1-pyrrolidinyl)-benzoic acid, named pistaciamide on the basis of the 1D-NMR, DEPT, HMQC and HMBCspectroscopic techniques.

  9. Particle production in higher derivative theory

    Indian Academy of Sciences (India)

    Cosmological models; particle production; higher derivative theory of gravitation. PACS No. 98.80. 1. ... is of singular models where the cosmic expansion is driven by the big-bang impulse; all ... According to Gibbs integrability condition, one cannot independently specify an equa- .... [3] B Hartle and S W Hawking Phys. Rev.

  10. morphological characteristics and classification of soils derived

    African Journals Online (AJOL)

    Prof. Ekwueme

    MORPHOLOGICAL CHARACTERISTICS AND CLASSIFICATION OF. SOILS DERIVED FROM DIVERSE PARENT MATERIALS IN CENTRAL. CROSS RIVER STATE, NIGERIA. 271. M. E. NSOR and I. J. IBANGA. (Received 5 October 2007; Revision Accepted 5 December 2007). ABSTRACT. Variation in soil characteristics ...

  11. Novel hydroquinone derivatives alleviate algesia, inflammation and ...

    African Journals Online (AJOL)

    The in silico studies predicted high binding affinity of the hydroquinone derivatives to the active site of the cyclooxygenase 2 (COX-2) enzyme. Conclusion: The synthesized hydroquinone compounds possess analgesic, antipyretic and antiinflammatory properties with low gastric-ulcerogenic potential. This may be credited to ...

  12. OPINION Is the repo a derivative?

    African Journals Online (AJOL)

    Introduction. The literature on the derivative markets and the spot (cash) financial markets ... value of R9 450 000, and the interest factor for the period of the repo is R35 000 ... mathematics is simple and in the case of bonds a little less simple.

  13. Characterization of sugar beet pulp derived oligosaccharides

    NARCIS (Netherlands)

    Leijdekkers, M.

    2015-01-01

    Abstract

    This thesis aimed at characterizing complex mixtures of sugar beet pulp derived oligosaccharides, in order to be able to monitor and optimize the enzymatic saccharification of sugar beet pulp.

    Hydrophilic interaction chromatography with on-line evaporative

  14. Nanomaterials derived from metal-organic frameworks

    Science.gov (United States)

    Dang, Song; Zhu, Qi-Long; Xu, Qiang

    2018-01-01

    The thermal transformation of metal-organic frameworks (MOFs) generates a variety of nanostructured materials, including carbon-based materials, metal oxides, metal chalcogenides, metal phosphides and metal carbides. These derivatives of MOFs have characteristics such as high surface areas, permanent porosities and controllable functionalities that enable their good performance in sensing, gas storage, catalysis and energy-related applications. Although progress has been made to tune the morphologies of MOF-derived structures at the nanometre scale, it remains crucial to further our knowledge of the relationship between morphology and performance. In this Review, we summarize the synthetic strategies and optimized methods that enable control over the size, morphology, composition and structure of the derived nanomaterials. In addition, we compare the performance of materials prepared by the MOF-templated strategy and other synthetic methods. Our aim is to reveal the relationship between the morphology and the physico-chemical properties of MOF-derived nanostructures to optimize their performance for applications such as sensing, catalysis, and energy storage and conversion.

  15. Actuarial risk measures for financial derivative pricing

    NARCIS (Netherlands)

    Goovaerts, M.J.; Laeven, R.J.A.

    2008-01-01

    We present an axiomatic characterization of price measures that are superadditive and comonotonic additive for normally distributed random variables. The price representation derived involves a probability measure transform that is closely related to the Esscher transform, and we call it the

  16. Immunochemical analysis of apamin and its derivatives

    International Nuclear Information System (INIS)

    Vasilenko, S.V.; Kolesnikova, I.N.; Miroshnikov, A.I.; Komissarenko, S.V.

    1981-01-01

    The radioimmunologic analysis of apamin (neurotoxin of the venom of Apis mellifica honey bee) is carried out using its derivatives which have modifications of various aminoacidic remnants and antibodies against apamin. The curves of 125 J apamin binding with antiserum against apamin and the curves of inhibition with various nonlabelled binding effectors of 125 J-apamin with antiserum are obtained

  17. Derivation of the Ideal Gas Law

    Science.gov (United States)

    Laugier, Alexander; Garai, Jozsef

    2007-01-01

    Undergraduate and graduate physics and chemistry books usually state that combining the gas laws results in the ideal gas law. Leaving the derivation to the students implies that this should be a simple task, most likely a substitution. Boyle's law, Charles's law, and the Avogadro's principle are given under certain conditions; therefore, direct…

  18. Cinnamic Acid Derivatives as Antidiabetics Agents

    Directory of Open Access Journals (Sweden)

    Teni Ernawati

    2017-04-01

    Full Text Available Diabetes mellitus is a metabolic disorder of carbohydrate metabolism. Treatment of type II diabetes is usually done by prescribing diet and exercise for the patient however it can also be treated with antidiabetic drugs. The purpose of this paper is to illustrate some cinnamic acid derivative compounds which are either isolated from natural materials or the results of the chemical synthesis. In addition, their biological activities as an agent of α-glucosidase inhibitors have also been evaluated. Chemically, cinnamic acid has three main functional groups:  first is the substitution on the phenyl group, second is the additive reaction into the α-β unsaturated, and third is the chemical reaction with carboxylic acid functional groups. Chemical aspects of cinnamic acid derivative compounds have received much attention in the research and development of drugs, especially modifications within three functional groups are very influential. In the last 10 years, a lot of research and development of cinnamic acid derivatives as inhibitors of the α-glucosidase enzyme has been done. One example of the research done in this field is the modification of para position in the structure of cinnamic acid and addition of alkyl groups in the carboxylic group which would increase the activity of the α-glucosidase enzyme therefore the level of inhibition is 100 times higher than that of cinnamic acid compound itself. The novelty of this review article is to focus on the antidiabetic activity of cinnamic acid derivatives.

  19. On pricing of interest rate derivatives

    OpenAIRE

    Di Matteo, T.; Airoldi, M.; Scalas, E.

    2004-01-01

    At present, there is an explosion of practical interest in the pricing of interest rate (IR) derivatives. Textbook pricing methods do not take into account the leptokurticity of the underlying IR process. In this paper, such a leptokurtic behaviour is illustrated using LIBOR data, and a possible martingale pricing scheme is discussed.

  20. Antimutagenic activity of dextran gammaphos derivatives

    International Nuclear Information System (INIS)

    Bakhitova, L.M.; Pashin, O.V.; Drobchenko, S.N.; Bondarev, G.I.

    1991-01-01

    In experiments with V-79 Chinese hamster cell culture the influence of dextran gammaphos derivatives on the mutagenic effects of γ-radiation was studied by the number of cells with micronuclei and fragmented nuclei. Products of interaction between gammaphos and dialdehyde dextran were shown to a higher antimutagenic activity than gammaphos

  1. Sol-Gel Derived Hafnia Coatings

    Science.gov (United States)

    Feldman, Jay D.; Stackpoole, Mairead; Blum, Yigal; Sacks, Michael; Ellerby, Don; Johnson, Sylvia M.; Venkatapathy, Ethiras (Technical Monitor)

    2002-01-01

    Sol-gel derived hafnia coatings are being developed to provide an oxidation protection layer on ultra-high temperature ceramics for potential use in turbine engines (ultra-efficient engine technology being developed by NASA). Coatings using hafnia sol hafnia filler particles will be discussed along with sol synthesis and characterization.

  2. Undesired Plant-Derived Components in Food

    NARCIS (Netherlands)

    Dusemund, Birgit; Rietjens, Ivonne M.C.M.; Abraham, Klaus; Cartus, Alexander; Schrenk, Dieter

    2017-01-01

    Among the various chemical compounds, the class of natural plant-derived substances in the modern food chain is generating increasing concern. Adverse effects encountered may be various and pose risks of acute, subchronic, or chronic toxicity. The underlying mechanisms of toxicity may be

  3. Knot invariants derived from quandles and racks

    OpenAIRE

    Kamada, Seiichi

    2002-01-01

    The homology and cohomology of quandles and racks are used in knot theory: given a finite quandle and a cocycle, we can construct a knot invariant. This is a quick introductory survey to the invariants of knots derived from quandles and racks.

  4. Supersymmetric higher derivative couplings and their applications

    NARCIS (Netherlands)

    Lodato, I.

    2014-01-01

    After an elementary introduction on black hole physics, supersymmetry and effective theories, which motivates the importance of higher derivative couplings in supergravity, we give an exhaustive treatment of the covariant phase space formalism with many examples explicitly worked out. This sets the

  5. Synthesis of hydroxy derivatives of limonene

    International Nuclear Information System (INIS)

    Ardashov, O V; Volcho, K P; Salakhutdinov, N F

    2014-01-01

    Synthetic routes to mono-, di- and trihydroxy derivatives of limonene are presented. Emphasis is given to the problems of regio- and stereoselectivity of transformations. Data on the isolation from natural sources and on the biological activities of the title compounds are given. The bibliography includes 107 references

  6. Approximate methods for derivation of covariance data

    International Nuclear Information System (INIS)

    Tagesen, S.

    1992-01-01

    Several approaches for the derivation of covariance information for evaluated nuclear data files (EFF2 and ENDF/B-VI) have been developed and used at IRK and ORNL respectively. Considerations, governing the choice of a distinct method depending on the quantity and quality of available data are presented, advantages/disadvantages are discussed and examples of results are given

  7. Waste-wood-derived fillers for plastics

    Science.gov (United States)

    Brent English; Craig M. Clemons; Nicole Stark; James P. Schneider

    1996-01-01

    Filled thermoplastic composites are stiffer, stronger, and more dimensionally stable than their unfilled counterparts. Such thermoplastics are usually provided to the end-user as a precompounded, pelletized feedstock. Typical reinforcing fillers are inorganic materials like talc or fiberglass, but materials derived from waste wood, such as wood flour and recycled paper...

  8. Deriving Process Congruences from Reaction Rules

    DEFF Research Database (Denmark)

    Sobocinski, Pawel

    This thesis is concerned with the development of a theory which, given a formalism with a reduction semantics, allows the derivation of a canonical labelled transition system on which bisimilarity as well as other other equiv� alences are congruences; provided that the contexts of the formalism f...

  9. Formula-derived prostate volume determination

    NARCIS (Netherlands)

    Aarnink, R. G.; de la Rosette, J. J.; Debruyne, F. M.; Wijkstra, H.

    1996-01-01

    OBJECTIVES: Despite disadvantages such as time-consuming and tedious to the user, planimetric volumetry is considered to be the most accurate method for prostate volume determination. This study investigates the possibilities of formula-derived volume determination and reveals the best alternative

  10. Surface tree languages and parallel derivation trees

    NARCIS (Netherlands)

    Engelfriet, Joost

    1976-01-01

    The surface tree languages obtained by top-down finite state transformation of monadic trees are exactly the frontier-preserving homomorphic images of sets of derivation trees of ETOL systems. The corresponding class of tree transformation languages is therefore equal to the class of ETOL languages.

  11. Higher-Derivative Supergravity and Moduli Stabilization

    International Nuclear Information System (INIS)

    Ciupke, David; Westphal, Alexander; Louis, Jan; Hamburg Univ.

    2015-05-01

    We review the ghost-free four-derivative terms for chiral superfields in N=1 supersymmetry and supergravity. These terms induce cubic polynomial equations of motion for the chiral auxiliary fields and correct the scalar potential. We discuss the different solutions and argue that only one of them is consistent with the principles of effective field theory. Special attention is paid to the corrections along flat directions which can be stabilized or destabilized by the higher-derivative terms. We then compute these higher-derivative terms explicitly for the type IIB string compactified on a Calabi-Yau orientifold with fluxes via Kaluza-Klein reducing the (α') 3 R 4 corrections in ten dimensions for the respective N=1 Kaehler moduli sector. We prove that together with flux and the known (α') 3 -corrections the higher-derivative term stabilizes all Calabi-Yau manifolds with positive Euler number, provided the sign of the new correction is negative.

  12. INVESTIGATION OF ANTIFUNGAL ACTIVITY OF QUINOLINIUM DERIVATIVES

    Directory of Open Access Journals (Sweden)

    G. A. Alexandrova

    2013-01-01

    Full Text Available Abstract. Antifungal activity (Candida albicans, Candida krusei of some substituted quinolinium derivatives has been investigated. It was established that the most perspective compound for detail investigation of antifungal activity by labeled biomarkers method was N-phenylbenzoquinaldinium tetrafluoroborate.

  13. Ineffective higher derivative black hole hair

    Science.gov (United States)

    Goldstein, Kevin; Mashiyane, James Junior

    2018-01-01

    Inspired by the possibility that the Schwarzschild black hole may not be the unique spherically symmetric vacuum solution to generalizations of general relativity, we consider black holes in pure fourth order higher derivative gravity treated as an effective theory. Such solutions may be of interest in addressing the issue of higher derivative hair or during the later stages of black hole evaporation. Non-Schwarzschild solutions have been studied but we have put earlier results on a firmer footing by finding a systematic asymptotic expansion for the black holes and matching them with known numerical solutions obtained by integrating out from the near-horizon region. These asymptotic expansions can be cast in the form of trans-series expansions which we conjecture will be a generic feature of non-Schwarzschild higher derivative black holes. Excitingly we find a new branch of solutions with lower free energy than the Schwarzschild solution, but as found in earlier work, solutions only seem to exist for black holes with large curvatures, meaning that one should not generically neglect even higher derivative corrections. This suggests that one effectively recovers the nonhair theorems in this context.

  14. Simulation of chemical reactions using fractional derivatives

    International Nuclear Information System (INIS)

    Zabadal, J.; Vilhena, M.; Livotto, P.

    2001-01-01

    In this work a new approach to solve time-dependant Schroedinger equation for molecular systems is proposed. The method employs functional derivatives to describe the time evolution of the wave functions in reactive systems, in order to establish the mechanisms and products of the reaction. A numerical simulation is reported

  15. Inequalities for a Polynomial and its Derivative

    Indian Academy of Sciences (India)

    Annual Meetings · Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Proceedings – Mathematical Sciences; Volume 110; Issue 2. Inequalities for a Polynomial and its Derivative. V K Jain. Volume 110 Issue 2 May 2000 pp 137- ...

  16. Derivation of the fine-structure constant

    International Nuclear Information System (INIS)

    Samec, A.

    1980-01-01

    The fine-structure constant is derived as a dynamical property of quantum electrodynamics. Single-particle solutions of the coupled Maxwell and Dirac equations have a physical charge spectrum. The solutions are used to construct lepton-and quark-like particles. The strong, weak, electromagnetic, and gravitational forces are described as the interactions of complex charges in multiple combinations

  17. Fundamentals of futures, options, basis and derivatives

    International Nuclear Information System (INIS)

    Jones, D.

    1997-01-01

    Characteristic features of futures and options contracts, basis differentials and derivatives were defined and explained. A futures contract refers to an exchange-traded supply contract between a buyer and a seller where the buyer is obligated to take delivery and the seller is obligated to provide delivery of a fixed amount of a commodity at a predetermined price at a specified location. In contrast, an option contract gives the purchaser the right, but not the obligation, to buy or sell the underlying commodity at a certain price on or before an agreed date. Basis differential refers to the discount between two distinct delivery points to reflect the relative value of a commodity, such as natural gas, at those points. Advantages and disadvantages of futures and options contacts, the factors affecting options pricing, and basis differentials, and the methods of calculating basis differentials were described. The nature and intricacies of derivatives, their benefits, in particular their use as a tool for the effective management of the volatilities associated with the oil and gas industry were explained. Their shortcomings such as the high liquidity risk, were also described. Examples of derivative transactions were provided to illustrate the interrelationships of futures/options/derivatives, and their role in financial risk management

  18. Risk Management and Financial Derivatives: An Overview

    NARCIS (Netherlands)

    S.M. Hammoudeh (Shawkat); M.J. McAleer (Michael)

    2012-01-01

    textabstractRisk management is crucial for optimal portfolio management. One of the fastest growing areas in empirical finance is the expansion of financial derivatives. The purpose of this special issue on “Risk Management and Financial Derivatives” is to highlight some areas in which novel

  19. WEATHER INDEX- THE BASIS OF WEATHER DERIVATIVES

    Directory of Open Access Journals (Sweden)

    Botos Horia Mircea

    2011-07-01

    Full Text Available This paper approaches the subject of Weather Derivatives, more exactly their basic element the weather index. The weather index has two forms, the Heating Degree Day (HDD and the Cooling Degree Day (CDD. We will try to explain their origin, use and the relationship between the two forms of the index. In our research we started from the analysis of the weather derivatives and what they are based on. After finding out about weather index, we were interested in understanding exactly how they work and how they influence the value of the contract. On the national level the research in the field is scares, but foreign materials available. The study for this paper was based firstly on reading about Weather Derivative, and then going in the meteorogical field and determining the way by which the indices were determined. After this, we went to the field with interest in the indices, such as the energy and gas industries, and figured out how they determined the weather index. For the examples we obtained data from the weather index database, and calculated the value for the period. The study is made on a period of five years, in 8 cities of the European Union. The result of this research is that we can now understand better the importance of the way the indices work and how they influence the value of the Weather Derivatives. This research has an implication on the field of insurance, because of the fact that weather derivative are at the convergence point of the stock markets and the insurance market. The originality of the paper comes from the personal touch given to the theoretical aspect and through the analysis of the HDD and CDD index in order to show their general behaviour and relationship.

  20. Derivative based sensitivity analysis of gamma index

    Directory of Open Access Journals (Sweden)

    Biplab Sarkar

    2015-01-01

    Full Text Available Originally developed as a tool for patient-specific quality assurance in advanced treatment delivery methods to compare between measured and calculated dose distributions, the gamma index (γ concept was later extended to compare between any two dose distributions. It takes into effect both the dose difference (DD and distance-to-agreement (DTA measurements in the comparison. Its strength lies in its capability to give a quantitative value for the analysis, unlike other methods. For every point on the reference curve, if there is at least one point in the evaluated curve that satisfies the pass criteria (e.g., δDD = 1%, δDTA = 1 mm, the point is included in the quantitative score as "pass." Gamma analysis does not account for the gradient of the evaluated curve - it looks at only the minimum gamma value, and if it is <1, then the point passes, no matter what the gradient of evaluated curve is. In this work, an attempt has been made to present a derivative-based method for the identification of dose gradient. A mathematically derived reference profile (RP representing the penumbral region of 6 MV 10 cm × 10 cm field was generated from an error function. A general test profile (GTP was created from this RP by introducing 1 mm distance error and 1% dose error at each point. This was considered as the first of the two evaluated curves. By its nature, this curve is a smooth curve and would satisfy the pass criteria for all points in it. The second evaluated profile was generated as a sawtooth test profile (STTP which again would satisfy the pass criteria for every point on the RP. However, being a sawtooth curve, it is not a smooth one and would be obviously poor when compared with the smooth profile. Considering the smooth GTP as an acceptable profile when it passed the gamma pass criteria (1% DD and 1 mm DTA against the RP, the first and second order derivatives of the DDs (δD', δD" between these two curves were derived and used as the

  1. A New Grünwald-Letnikov Derivative Derived from a Second-Order Scheme

    Directory of Open Access Journals (Sweden)

    B. A. Jacobs

    2015-01-01

    Full Text Available A novel derivation of a second-order accurate Grünwald-Letnikov-type approximation to the fractional derivative of a function is presented. This scheme is shown to be second-order accurate under certain modifications to account for poor accuracy in approximating the asymptotic behavior near the lower limit of differentiation. Some example functions are chosen and numerical results are presented to illustrate the efficacy of this new method over some other popular choices for discretizing fractional derivatives.

  2. Arbitrage-free valuation of energy derivatives

    International Nuclear Information System (INIS)

    Amin, K.; Ng, V.; Pirrong, C.

    1999-01-01

    This chapter focuses on techniques available for valuing energy-contingent claims and develops an arbitrage-free framework to value energy derivatives. The relationship between the spot, forward and futures prices is explained. Option valuation with deterministic convenience yields is discussed using an extension of the Black (1976) framework, and details of the risk-neutral valuation of European options, and valuation of American and European-style options are given. Option valuations with stochastic convenience yields, the evolution of the term structure of convenience yield, and a tree approach to valuing American and other options are discussed. Applications and limitations of the models for pricing energy derivative products are considered. The stochastic differential equation for the futures prices when the convenience yields are stochastic is presented in an appendix

  3. Fundamentals and advanced techniques in derivatives hedging

    CERN Document Server

    Bouchard, Bruno

    2016-01-01

    This book covers the theory of derivatives pricing and hedging as well as techniques used in mathematical finance. The authors use a top-down approach, starting with fundamentals before moving to applications, and present theoretical developments alongside various exercises, providing many examples of practical interest. A large spectrum of concepts and mathematical tools that are usually found in separate monographs are presented here. In addition to the no-arbitrage theory in full generality, this book also explores models and practical hedging and pricing issues. Fundamentals and Advanced Techniques in Derivatives Hedging further introduces advanced methods in probability and analysis, including Malliavin calculus and the theory of viscosity solutions, as well as the recent theory of stochastic targets and its use in risk management, making it the first textbook covering this topic. Graduate students in applied mathematics with an understanding of probability theory and stochastic calculus will find this b...

  4. Higher derivatives and renormalization in quantum cosmology

    International Nuclear Information System (INIS)

    Mazzitelli, F.D.

    1991-10-01

    In the framework of the canonical quantization of general relativity, quantum field theory on a fixed background formally arises in an expansion in powers of the Planck length. In order to renormalize the theory, quadratic terms in the curvature must be included in the gravitational action from the beginning. These terms contain higher derivatives which change the Hamiltonian structure of the theory completely, making the relation between the renormalized-theory and the original one not clear. We show that it is possible to avoid this problem. We replace the higher derivative theory by a second order one. The classical solutions of the latter are also solutions of the former. We quantize the theory, renormalize the infinities and show that there is a smooth limit between the classical and the renormalized theories. We work in a Robertson Walker minisuperspace with a quantum scalar field. (author). 32 refs

  5. Renminbi Derivatives: Recent Development and Issues

    Institute of Scientific and Technical Information of China (English)

    Wensheng Peng; Chang Shu; Raymond Yip

    2007-01-01

    This study reviews the developments in the onshore and offshore renminbi derivatives markets. The onshore market has seen a rapid build-up in the market infrastructure and price discovery mechanism in the past year, with empirical evidence suggesting that its pricing is increasingly determined by financial fundamentals, such as the covered interest rate parity. However, the growth of the market has been restrained by restrictions on the participant base, limited variations in the RMB/US$ exchange rate, market participants'lack of technical capacity and experience, and inadequate supporting financial market infrastructure. The non-deliverable forward (NDF) market, concentrated in Hong Kong and Singapore, is more developed, but has the drawback that its pricing is not tied to financial fundamentals. The comparison between onshore and offshore markets suggests that two issues are of particular importance for future derivatives market development in China: the balance between regulation and development, and the relationship between onshore and offshore markets.

  6. Electrochemical Behavior of Biologically Important Indole Derivatives

    Directory of Open Access Journals (Sweden)

    Cigdem Karaaslan

    2011-01-01

    Full Text Available Voltammetric techniques are most suitable to investigate the redox properties of a new drug. Use of electrochemistry is an important approach in drug discovery and research as well as quality control, drug stability, and determination of physiological activity. The indole nucleus is an essential element of a number of natural and synthetic products with significant biological activity. Indole derivatives are the well-known electroactive compounds that are readily oxidized at carbon-based electrodes, and thus analytical procedures, such as electrochemical detection and voltammetry, have been developed for the determination of biologically important indoles. This paper explains some of the relevant and recent achievements in the electrochemistry processes and parameters mainly related to biologically important indole derivatives in view of drug discovery and analysis.

  7. Algebraic theory of locally nilpotent derivations

    CERN Document Server

    Freudenburg, Gene

    2017-01-01

    This book explores the theory and application of locally nilpotent derivations, a subject motivated by questions in affine algebraic geometry and having fundamental connections to areas such as commutative algebra, representation theory, Lie algebras and differential equations. The author provides a unified treatment of the subject, beginning with 16 First Principles on which the theory is based. These are used to establish classical results, such as Rentschler's Theorem for the plane and the Cancellation Theorem for Curves. More recent results, such as Makar-Limanov's theorem for locally nilpotent derivations of polynomial rings, are also discussed. Topics of special interest include progress in classifying additive actions on three-dimensional affine space, finiteness questions (Hilbert's 14th Problem), algorithms, the Makar-Limanov invariant, and connections to the Cancellation Problem and the Embedding Problem. A lot of new material is included in this expanded second edition, such as canonical factoriza...

  8. Feynman graph derivation of Einstein quadrupole formula

    International Nuclear Information System (INIS)

    Dass, N.D.H.; Soni, V.

    1980-11-01

    The one graviton transition operator, and consequently, the classical energy loss formula for gravitational radiation are derived from the Feynman graphs of helicity +- 2 theories of gravitation. The calculations are done both for the case of electromagnetic and gravitational scattering. The departure of the in and out states from plane waves owing to the long range nature of gravitation is taken into account to improve the Born approximation calculations. This also includes a long range modification of the graviton wave function which is shown to be equivalent to the classical problem of the true light cones deviating logarithmically at large distances from the flat space light cones. The transition from the S-matrix elements calculated graphically to the graviton transition operator is done by using complimentarity of space-time and momentum descriptions. The energy loss formula derived originally by Einstein is shown to be correct. (Auth.)

  9. Biodegradation of polyurethane derived from castor oil

    Directory of Open Access Journals (Sweden)

    José M. Cangemi

    2008-09-01

    Full Text Available The aim of this research was to study the biodegradation of a polymer derived from castor oil, which is a renewable, natural material that is a practical alternative for the replacement of traditional polyurethane foams. Due to its molecular structure, which contains polyester segments derived from vegetable oil, the polymeric surface is susceptible to microorganism attack. This study tested the biological degrading agent that was in contact with the microorganisms resulting from microbiological grease degrading agents, when foam was inoculated. Solid-media agar-plate tests were conducted for their potential to evaluate the biodegradation of polymeric particles by specific strains of microorganisms during 216 hours. The growth rate was defined. This technique provides a way of distinguishing the degradation abilities of microorganisms from the degradability of materials.

  10. Phloroglucinol derivatives and flavones from Helichrysum paronychioides

    Directory of Open Access Journals (Sweden)

    J. Mutanyatta-Comar

    2006-06-01

    Full Text Available Investigation of Helichrysum paronychioides afforded a total of nine compounds: 4 phloroglucinol derivatives, 2 of which are novel natural products, and 5 flavone derivatives. Structures were established by various spectroscopic techniques (NMR, MS, UV, IR, CD and by comparison with literature data for the known compounds. The four phloroglucinols, trans-(2R,3R-5,7-dihydroxy-2,3-dimethyl-4-chromanone (1, 2-butanoyl-4-prenyl-1-methoxy phloroglucinol (2, 2-(2-methylpropanoyl-4-prenylphloroglucinol (3 and 2-(2-methyl- butanoyl-4-prenylphloroglucinol (4 were screened for antioxidant activity against Cu-induced LDL oxidation. Compound 4 was found to be the most active inhibiting LDL oxidation at all concentrations (0.5-10 μM while the other three showed moderate to no activity.

  11. Inconsistency of Minkowski higher-derivative theories

    Energy Technology Data Exchange (ETDEWEB)

    Aglietti, Ugo G. [Universita di Roma ' ' La Sapienza' ' , Dipartimento di Fisica, Rome (Italy); Anselmi, Damiano [Universita di Pisa, Dipartimento di Fisica ' ' Enrico Fermi' ' , Pisa (Italy); INFN, Sezione di Pisa, Pisa (Italy)

    2017-02-15

    We show that Minkowski higher-derivative quantum field theories are generically inconsistent, because they generate nonlocal, non-hermitian ultraviolet divergences, which cannot be removed by means of standard renormalization procedures. By ''Minkowski theories'' we mean theories that are defined directly in Minkowski spacetime. The problems occur when the propagators have complex poles, so that the correlation functions cannot be obtained as the analytic continuations of their Euclidean versions. The usual power counting rules fail and are replaced by much weaker ones. Self-energies generate complex divergences proportional to inverse powers of D'Alembertians. Three-point functions give more involved nonlocal divergences, which couple to infrared effects. We illustrate the violations of the locality and hermiticity of counterterms in scalar models and higher-derivative gravity. (orig.)

  12. Evaluation of antiproliferative activity of pyrazolothiazolopyrimidine derivatives

    Directory of Open Access Journals (Sweden)

    N. S. Finiuk

    2018-04-01

    Full Text Available The research aim was to test cytotoxic effects in vitro of seven novel pyrazolothiazolopyrimidine derivatives in targeting several lines of tumor and pseudo-normal mammalian cells. We demonstrated that cytotoxic effects of these derivatives depended on the tissue origin of targeted cells. Leukemia cells were found to be the most sensitive to the action of compounds 2 and 7. Compound 2 demonstrated approximately two times higher toxicity towards the multidrug-resistant sub-line of HL-60/ADR cells compared to the Doxorubicin effect. Antiproliferative action of compounds 2 and 7 dropped in the order: leukemia > melanoma > hepatocarcinoma > glioblastoma > colon carcinoma > breast and ovarian carcinoma cells. These compounds were less toxic than Doxorubicin towards the non-tumor cells. The novel pyrazolothiazolopyrimidine, compound 2, demonstrated high toxicity towards human leukemia and, of special importance, towards multidrug-resistant leukemia cells, and low toxicity towards pseudo-normal cells.

  13. A generalization of the Lie derivative

    International Nuclear Information System (INIS)

    Dolan, P.

    1984-01-01

    If X=xisup(i)deltasub(i) and Y=etasup(i)deltasub(i) are vector fields then it is well-known that the Lie derivative Poundsub(X)Y equivalent to [X,Y] (xisup(s)deltasub(s) etasup(s)deltasub(s)xisup(i))deltasub(i) is also a vector field under general coordinate transformations. A generalization of this result, due to previous workers, allows a definition of Poundsub(F)G, where F,G are arbitrary contravariant tensor fields. The formulae are linear in the first partial derivatives of F and G. An application to the theory of Killing-Yano tensor fields on Riemannian manifolds is given. (author)

  14. Folic acid derivatives for use in radioimmunoassay

    International Nuclear Information System (INIS)

    Ali, A.

    1981-01-01

    The chemical preparation of two folic acid derivatives, labelled with 125 I or 131 I, is described for use in radioimmunoassay of folic acid and its metabolites in biological fluids such as blood serum. Labelled compounds of the present invention more closely resemble folic acid in that they have glutamic acid in the terminal position. Examples of the use of these compounds in three different assays are given. (U.K.)

  15. Parallel Aircraft Trajectory Optimization with Analytic Derivatives

    Science.gov (United States)

    Falck, Robert D.; Gray, Justin S.; Naylor, Bret

    2016-01-01

    Trajectory optimization is an integral component for the design of aerospace vehicles, but emerging aircraft technologies have introduced new demands on trajectory analysis that current tools are not well suited to address. Designing aircraft with technologies such as hybrid electric propulsion and morphing wings requires consideration of the operational behavior as well as the physical design characteristics of the aircraft. The addition of operational variables can dramatically increase the number of design variables which motivates the use of gradient based optimization with analytic derivatives to solve the larger optimization problems. In this work we develop an aircraft trajectory analysis tool using a Legendre-Gauss-Lobatto based collocation scheme, providing analytic derivatives via the OpenMDAO multidisciplinary optimization framework. This collocation method uses an implicit time integration scheme that provides a high degree of sparsity and thus several potential options for parallelization. The performance of the new implementation was investigated via a series of single and multi-trajectory optimizations using a combination of parallel computing and constraint aggregation. The computational performance results show that in order to take full advantage of the sparsity in the problem it is vital to parallelize both the non-linear analysis evaluations and the derivative computations themselves. The constraint aggregation results showed a significant numerical challenge due to difficulty in achieving tight convergence tolerances. Overall, the results demonstrate the value of applying analytic derivatives to trajectory optimization problems and lay the foundation for future application of this collocation based method to the design of aircraft with where operational scheduling of technologies is key to achieving good performance.

  16. Cholestane derivatives as antitumor and antiangiogenic drugs

    Czech Academy of Sciences Publication Activity Database

    Hoffmannová, L.; Steigerová, J.; Oklešťková, J.; Kohout, Ladislav; Chodounská, Hana; Hniličková, Jaroslava; Kasal, Alexander; Černý, Ivan; Kolář, Z.; Strnad, M.

    2010-01-01

    Roč. 35, SA (2010), s. 205-205 ISSN 0377-8282. [EFMC-ISMC 2010. International Symposium on Medicinal Chemistry /21./. 05.09.2010-09.09.2010, Brussels] R&D Projects: GA MŠk(CZ) LC06077; GA AV ČR KAN200200651 Institutional research plan: CEZ:AV0Z40550506 Keywords : cholestane derivatives * anticancer drugs Subject RIV: CC - Organic Chemistry

  17. On the Feasibility of Decentralized Derivatives Markets

    OpenAIRE

    Eskandari, Shayan; Clark, Jeremy; Sundaresan, Vignesh; Adham, Moe

    2018-01-01

    In this paper, we present Velocity, a decentralized market deployed on Ethereum for trading a custom type of derivative option. To enable the smart contract to work, we also implement a price fetching tool called PriceGeth. We present this as a case study, noting challenges in development of the system that might be of independent interest to whose working on smart contract implementations. We also apply recent academic results on the security of the Solidity smart contract language in valida...

  18. The Brain Derived Neurotrophic Factor and Personality

    OpenAIRE

    Christian Montag

    2014-01-01

    The study of the biological basis of personality is a timely research endeavor, with the aim of deepening our understanding of human nature. In recent years, a growing body of research has investigated the role of the brain derived neurotrophic factor (BDNF) in the context of individual differences across human beings, with a focus on personality traits. A large number of different approaches have been chosen to illuminate the role of BDNF for personality, ranging from the measurement of BDNF...

  19. Alkylation of Zwitterionic Thiooxalic Acid Derivatives

    Directory of Open Access Journals (Sweden)

    Manfred Michalik

    2001-05-01

    Full Text Available The new S-alkyl thiooxal-1-hydrazono-2-amidrazonium halides 2-4 were synthesized by reaction of the corresponding zwitterionic thiooxalic acid derivatives 1 with alkyl halides in methanol. The structures of compounds 4b and 4d were proven by X-ray structural analysis. Both compounds form an interesting intermolecular network of hydrogen bonds in the solid state.

  20. Coronary CT Angiography Derived Fractional Flow Reserve

    DEFF Research Database (Denmark)

    Nørgaard, Bjarne Linde; Jensen, Jesper Møller; Blanke, Philipp

    2017-01-01

    Purpose of Review: To summarize the scientific basis of CT derived fractional flow reserve (FFRCT) and present an updated review on the evidence from clinical trials and real-world observational data Recent Findings: In prospective multicenter studies of patients with stable coronary artery disea...... of patients with stable CAD. The optimal FFRCT testing interpretation strategy, as well as the relative cost-efficiency of FFRCT against standard noninvasive functional testing, need further investigation....

  1. Eisenhart lift for higher derivative systems

    Energy Technology Data Exchange (ETDEWEB)

    Galajinsky, Anton, E-mail: galajin@tpu.ru; Masterov, Ivan, E-mail: masterov@tpu.ru

    2017-02-10

    The Eisenhart lift provides an elegant geometric description of a dynamical system of second order in terms of null geodesics of the Brinkmann-type metric. In this work, we attempt to generalize the Eisenhart method so as to encompass higher derivative models. The analysis relies upon Ostrogradsky's Hamiltonian. A consistent geometric description seems feasible only for a particular class of potentials. The scheme is exemplified by the Pais–Uhlenbeck oscillator.

  2. Strong commutativity preserving generalized derivations on ...

    African Journals Online (AJOL)

    Let R be a non-commutative prime ring of characteristic different from 2, with right Utumi quotient ring U and extended centroid C and let F and G be generalized derivations of R such that F(x)G(y)-F(y)G(x) = [x; y], for all x; y ∈ S, where S is a subset of R. Here we will discuss the following cases: (a) S = [R;R];. b) S = L, where ...

  3. Covariant derivatives of the Berezin transform

    Czech Academy of Sciences Publication Activity Database

    Engliš, Miroslav; Otáhalová, R.

    2011-01-01

    Roč. 363, č. 10 (2011), s. 5111-5129 ISSN 0002-9947 R&D Projects: GA AV ČR IAA100190802 Keywords : Berezin transform * Berezin symbol * covariant derivative Subject RIV: BA - General Mathematics Impact factor: 1.093, year: 2011 http://www.ams.org/journals/tran/2011-363-10/S0002-9947-2011-05111-1/home.html

  4. Derivation of plutonium-239 materials disposition categories

    International Nuclear Information System (INIS)

    Brough, W.G.

    1995-01-01

    At this time, the Office of Fissile Materials Disposition within the DOE, is assessing alternatives for the disposition of excess fissile materials. To facilitate the assessment, the Plutonium-Bearing Materials Feed Report for the DOE Fissile Materials Disposition Program Alternatives report was written. The development of the material categories and the derivation of the inventory quantities associated with those categories is documented in this report

  5. On butterfly effect in higher derivative gravities

    Energy Technology Data Exchange (ETDEWEB)

    Alishahiha, Mohsen [School of Physics, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Davody, Ali; Naseh, Ali; Taghavi, Seyed Farid [School of Particles and Accelerators, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

    2016-11-07

    We study butterfly effect in D-dimensional gravitational theories containing terms quadratic in Ricci scalar and Ricci tensor. One observes that due to higher order derivatives in the corresponding equations of motion there are two butterfly velocities. The velocities are determined by the dimension of operators whose sources are provided by the metric. The three dimensional TMG model is also studied where we get two butterfly velocities at generic point of the moduli space of parameters. At critical point two velocities coincide.

  6. On butterfly effect in higher derivative gravities

    International Nuclear Information System (INIS)

    Alishahiha, Mohsen; Davody, Ali; Naseh, Ali; Taghavi, Seyed Farid

    2016-01-01

    We study butterfly effect in D-dimensional gravitational theories containing terms quadratic in Ricci scalar and Ricci tensor. One observes that due to higher order derivatives in the corresponding equations of motion there are two butterfly velocities. The velocities are determined by the dimension of operators whose sources are provided by the metric. The three dimensional TMG model is also studied where we get two butterfly velocities at generic point of the moduli space of parameters. At critical point two velocities coincide.

  7. Literature Review of Polymer Derived Ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Reuben James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-25

    Polymer Derived Ceramics (PDCs), also known as preceramic polymers, are valuable coating agents that are used to produce surface barriers on substrates such as stainless steel. These barriers protect against a multitude of environmental threats, and have been used since their research and development in 19772. This paper seeks to review and demonstrate the remarkable properties and versatility that PDCs have to offer, while also giving a brief overview of the processing techniques used today.

  8. Photoinactivation of HIV by benzoporphyrin derivative

    International Nuclear Information System (INIS)

    North, J.; Levy, J.; Coombs, R.

    1992-01-01

    Using both the feline leukemia virus and human immunodeficiency virus it is shown that the photosensitizer benzoporphyrin derivative when activated by narrow band red light is effective in eliminating both free virus and virally infected leukocytes from spiked blood products and whole blood drawn from either virally infected animals or humans, under conditions which appear to spare red cell and uninfected leukocytes. (author). 14 refs., 7 figs

  9. Derivatives of the Incomplete Beta Function

    Directory of Open Access Journals (Sweden)

    Robert J. Boik

    1998-03-01

    Full Text Available The incomplete beta function is defined as where Beta(p, q is the beta function. Dutka (1981 gave a history of the development and numerical evaluation of this function. In this article, an algorithm for computing first and second derivatives of Ix,p,q with respect to p and q is described. The algorithm is useful, for example, when fitting parameters to a censored beta, truncated beta, or a truncated beta-binomial model.

  10. Detectability in a derivative Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Yoshimura, Takeaki; Miyamoto, Masashi; Wakabayashi, Nobuo

    1978-01-01

    In Moessbauer spectrometry, a criterion for detecting a faint peak under the condition that the peak is superimposed onto a tail of a large and broad peak is discussed. By adopting a derivative method, it is found that the criterion is improved in comparison with a usual method, and that the condition for determining the modulation amplitude W/2 is 1.5 GAMMA 1 1 where GAMMA 1 is the spectral linewidth of the faint peak. (auth.)

  11. Bio-Detergent oil derivative used frying

    Directory of Open Access Journals (Sweden)

    Alfonso Jesús Torres Ortega

    2011-04-01

    Full Text Available Currently, the global trend towards sustainable development for environmental friendly products such as biosurfactants shows an excellent performance. Anionic surface active agents can be produced from renewable natural raw materials such as vegetable oils mainly derived from palm oil. Methyl ester sulfonate is an active component of highly biodegradable detergents, one advantage compared with detergents derived from petrochemicals which generate a high pollutant load. This paper proposes the study of sulfonation with sulfur trioxide of esters derived from waste cooking oil which main component is palm oil. The falling film reactor allows determining the conditions of the process at pilot scale. The experimentation allowed an enhancement of empirical equations in the equipment implemented for this purpose and to determine some physicochemical properties. The comparison obtained for this same process with petrochemicals compounds indicates that the model could be applied to any film sulfonation but adjusting the parameters and specific conditions, such as the physicochemical properties of the compounds used, since the sulfonation process described in this work is one of the more complicated cases. The technological development presented here seeks to contribute with the industrial needs to promote green chemical industry for the production of biosurfactant from waste frying oil.

  12. 7-oxygenated Derivatives of Dehydroepiandrosterone and Obesity

    Directory of Open Access Journals (Sweden)

    B. Sedláčková

    2012-01-01

    Full Text Available 7-hydroxy/oxo derivatives of dehydroepiandrosterone are potential regulators of the local cortisol activity due to their competition in the cortisolcortisone balance mediated by 11β-hydroxysteroid dehydrogenase. 7-hydroxydehydroepiandrosterone is marketed as anti-obesity medication, though no clinical study aimed at the benefit of administering 7-oxygenated derivatives of dehydroepiandrosterone has appeared until now. We tried to show whether there exist differences in levels of circulating 7-hydroxy/oxo-dehydroepiandrosterone derivatives between lean and obese boys and girls. From a cohort of adolescents investigated within the frame of anti-obesity programme 10 obese boys and 10 obese girls were compared with age-matched lean boys and girls in their anthropometric data, and concentrations of both epimers of 7-hydroxydehydroepiandrosterone and 7-oxo-dehydroepiandrosterone were determined by the RIA method. The basal levels of 7α-hydroxy-dehydroepiandrosterone were significantly higher in obese boys than in lean boys but not in girls. The association was found for anthropometric parameters and 7α-hydroxy-dehydroepiandrosterone, however again only in boys and not in girls. Higher levels of 7α-hydroxydehydroepiandrosterone its positive association with anthropometric data in obese boys may serve as a sign that, at least in boys, 7-oxygenated 5-ene-steroids may take part in regulating the hormonal signal for fat formation or distribution.

  13. Metal complex derivatives of hydrogen uranyl phosphate

    International Nuclear Information System (INIS)

    Grohol, D.; Blinn, E.L.

    1994-01-01

    Derivatives of hydrogen uranyl phosphate were prepared by incorporating transition metal complexes into the uranyl phosphate matrix. The transition metal complexes employed include bis(ethylenediamine)copper(II), bis(1,3-propanediamine)copper(II) chloride, (triethylenetetramine)copper(II), (1,4,8,11-tetraazacyclotetradecane)copper(II), (1,4,8,12-tetraazacyclopentadecane)copper(II), (1,4,8,11-tetraazacyclotetradecane)nickel(II) chloride, (triethylenetetramine)nickel(II) and others. The chemical analyses of these derivatives indicated that the incorporation of the transition metal complexes into the uranyl phosphate matrix via ion exchange was not stoichiometric. The extent of ion exchange is dependent on the size and structure of the transition metal complex. All complexes were characterized by X-ray powder diffractometry, electronic and infrared spectra, thermal analyses and chemical analysis. An attempt was made to correlate the degree of quenching of the luminescence of the uranyl ion to the spacing between the uranyl phosphate layers in the derivatives

  14. Price models for oil derivates in Slovenia

    International Nuclear Information System (INIS)

    Nemac, F.; Saver, A.

    1995-01-01

    In Slovenia, a law is currently applied according to which any change in the price of oil derivatives is subject to the Governmental approval. Following the target of getting closer to the European Union, the necessity has arisen of finding ways for the introduction of liberalization or automated approach to price modifications depending on oscillations of oil derivative prices on the world market and the rate of exchange of the American dollar. It is for this reason that at the Agency for Energy Restructuring we made a study for the Ministry of Economic Affairs and Development regarding this issue. We analysed the possible models for the formation of oil derivative prices for Slovenia. Based on the assessment of experiences of primarily the west European countries, we proposed three models for the price formation for Slovenia. In future, it is expected that the Government of the Republic of Slovenia will make a selection of one of the proposed models to be followed by enforcement of price liberalization. The paper presents two representative models for price formation as used in Austria and Portugal. In the continuation the authors analyse the application of three models that they find suitable for the use in Slovenia. (author)

  15. Surface spectral emissivity derived from MODIS data

    Science.gov (United States)

    Chen, Yan; Sun-Mack, Sunny; Minnis, Patrick; Smith, William L.; Young, David F.

    2003-04-01

    Surface emissivity is essential for many remote sensing applications including the retrieval of the surface skin temperature from satellite-based infrared measurements, determining thresholds for cloud detection and for estimating the emission of longwave radiation from the surface, an important component of the energy budget of the surface-atmosphere interface. In this paper, data from the Terra MODIS (MODerate-resolution Imaging Spectroradiometer) taken at 3.7, 8.5, 10.8, 12.0 micron are used to simultaneously derive the skin temperature and the surface emissivities at the same wavelengths. The methodology uses separate measurements of the clear-sky temperatures that are determined by the CERES (Clouds and Earth's Radiant Energy System) scene classification in each channel during the daytime and at night. The relationships between the various channels at night are used during the day when solar reflectance affects the 3.7 micron data. A set of simultaneous equations is then solved to derive the emissivities. Global results are derived from MODIS. Numerical weather analyses are used to provide soundings for correcting the observed radiances for atmospheric absorption. These results are verified and will be available for remote sensing applications.

  16. Modeling of heat conduction via fractional derivatives

    Science.gov (United States)

    Fabrizio, Mauro; Giorgi, Claudio; Morro, Angelo

    2017-09-01

    The modeling of heat conduction is considered by letting the time derivative, in the Cattaneo-Maxwell equation, be replaced by a derivative of fractional order. The purpose of this new approach is to overcome some drawbacks of the Cattaneo-Maxwell equation, for instance possible fluctuations which violate the non-negativity of the absolute temperature. Consistency with thermodynamics is shown to hold for a suitable free energy potential, that is in fact a functional of the summed history of the heat flux, subject to a suitable restriction on the set of admissible histories. Compatibility with wave propagation at a finite speed is investigated in connection with temperature-rate waves. It follows that though, as expected, this is the case for the Cattaneo-Maxwell equation, the model involving the fractional derivative does not allow the propagation at a finite speed. Nevertheless, this new model provides a good description of wave-like profiles in thermal propagation phenomena, whereas Fourier's law does not.

  17. FOREST AREA DERIVATION FROM SENTINEL-1 DATA

    Directory of Open Access Journals (Sweden)

    A. Dostálová

    2016-06-01

    Full Text Available The recently launched Sentinel-1A provides the high resolution Synthetic Aperture Radar (SAR data with very high temporal coverage over large parts of European continent. Short revisit time and dual polarization availability supports its usability for forestry applications. The following study presents an analysis of the potential of the multi-temporal dual-polarization Sentinel-1A data for the forest area derivation using the standard methods based on Otsu thresholding and K-means clustering. Sentinel-1 data collected in winter season 2014-2015 over a test area in eastern Austria were used to derive forest area mask with spatial resolution of 10m and minimum mapping unit of 500 m2. The validation with reference forest mask derived from airborne full-waveform laser scanning data revealed overall accuracy of 92 % and kappa statistics of 0.81. Even better results can be achieved when using external mask for urban areas, which might be misclassified as forests when using the introduced approach based on SAR data only. The Sentinel-1 data and the described methods are well suited for forest change detection between consecutive years.

  18. P-Splines Using Derivative Information

    KAUST Repository

    Calderon, Christopher P.

    2010-01-01

    Time series associated with single-molecule experiments and/or simulations contain a wealth of multiscale information about complex biomolecular systems. We demonstrate how a collection of Penalized-splines (P-splines) can be useful in quantitatively summarizing such data. In this work, functions estimated using P-splines are associated with stochastic differential equations (SDEs). It is shown how quantities estimated in a single SDE summarize fast-scale phenomena, whereas variation between curves associated with different SDEs partially reflects noise induced by motion evolving on a slower time scale. P-splines assist in "semiparametrically" estimating nonlinear SDEs in situations where a time-dependent external force is applied to a single-molecule system. The P-splines introduced simultaneously use function and derivative scatterplot information to refine curve estimates. We refer to the approach as the PuDI (P-splines using Derivative Information) method. It is shown how generalized least squares ideas fit seamlessly into the PuDI method. Applications demonstrating how utilizing uncertainty information/approximations along with generalized least squares techniques improve PuDI fits are presented. Although the primary application here is in estimating nonlinear SDEs, the PuDI method is applicable to situations where both unbiased function and derivative estimates are available.

  19. Generalised derived limits for radioisotopes of iodine

    International Nuclear Information System (INIS)

    Hughes, J.S.; Haywood, S.M.; Simmonds, J.R.

    1984-04-01

    Generalised Derived Limits (GDLs) are evaluated for iodine-125,129,131,132,133,134,135 in selected materials from the terrestrial and aquatic environments and for discharge to atmosphere. They are intended for use as convenient reference levels against which the results of environmental monitoring can be compared and atmospheric discharges assessed. GDLs are intended for use when the environmental contamination or discharge to atmosphere is less than about 5% of the GDL. If the level of environmental contamination or discharge to the atmosphere exceeds this percentage of the GDL it does not necessarily mean that the dose equivalents to members of the public are approaching the dose equivalent limit. It is rather an indication that it may be appropriate to obtain a more specific derived limit for the particular situation by reviewing the values of the parameters involved in the calculation. GDL values are specified for iodine radionuclides in water, soil, grass, sediments and various foodstuffs derived from the terrestrial and aquatic environments. GDLs are also given for iodine radionuclides on terrestrial surfaces and for their discharge to atmosphere. (author)

  20. Naturally Occurring Cinnamic Acid Sugar Ester Derivatives

    Directory of Open Access Journals (Sweden)

    Yuxin Tian

    2016-10-01

    Full Text Available Cinnamic acid sugar ester derivatives (CASEDs are a class of natural product with one or several phenylacrylic moieties linked with the non-anomeric carbon of a glycosyl skeleton part through ester bonds. Their notable anti-depressant and brains protective activities have made them a topic of great interest over the past several decades. In particular the compound 3′,6-disinapoylsucrose, the index component of Yuanzhi (a well-known Traditional Chinese Medicine or TCM, presents antidepressant effects at a molecular level, and has become a hotspot of research on new lead drug compounds. Several other similar cinnamic acid sugar ester derivatives are reported in traditional medicine as compounds to calm the nerves and display anti-depression and neuroprotective activity. Interestingly, more than one third of CASEDs are distributed in the family Polygalaceae. This overview discusses the isolation of cinnamic acid sugar ester derivatives from plants, together with a systematic discussion of their distribution, chemical structures and properties and pharmacological activities, with the hope of providing references for natural product researchers and draw attention to these interesting compounds.

  1. 32 CFR 2400.16 - Derivative classification markings.

    Science.gov (United States)

    2010-07-01

    ... SECURITY PROGRAM Derivative Classification § 2400.16 Derivative classification markings. (a) Documents... 32 National Defense 6 2010-07-01 2010-07-01 false Derivative classification markings. 2400.16..., as described in § 2400.12 of this part, the information may not be used as a basis for derivative...

  2. 17 CFR 240.16a-4 - Derivative securities.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Derivative securities. 240.16a....16a-4 Derivative securities. (a) For purposes of section 16 of the Act, both derivative securities and... securities, except that the acquisition or disposition of any derivative security shall be separately...

  3. 14 CFR 1203.501 - Applying derivative classification markings.

    Science.gov (United States)

    2010-01-01

    ... INFORMATION SECURITY PROGRAM Derivative Classification § 1203.501 Applying derivative classification markings. Persons who apply derivative classification markings shall: (a) Observe and respect original... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Applying derivative classification markings...

  4. On Functional Inequalities Originating from Module Jordan Left Derivations

    OpenAIRE

    Kang Sheon-Young; Chang Ick-Soon; Kim Hark-Mahn

    2008-01-01

    Abstract We first examine the generalized Hyers-Ulam stability of functional inequality associated with module Jordan left derivation (resp., module Jordan derivation). Secondly, we study the functional inequality with linear Jordan left derivation (resp., linear Jordan derivation) mapping into the Jacobson radical.

  5. On Functional Inequalities Originating from Module Jordan Left Derivations

    Directory of Open Access Journals (Sweden)

    Kang Sheon-Young

    2008-01-01

    Full Text Available Abstract We first examine the generalized Hyers-Ulam stability of functional inequality associated with module Jordan left derivation (resp., module Jordan derivation. Secondly, we study the functional inequality with linear Jordan left derivation (resp., linear Jordan derivation mapping into the Jacobson radical.

  6. Lie n-derivations on 7 -subspace lattice algebras

    Indian Academy of Sciences (India)

    all x ∈ K and all A ∈ Alg L. Based on this result, a complete characterization of linear n-Lie derivations on Alg L is obtained. Keywords. J -subspace lattice algebras; Lie derivations; Lie n-derivations; derivations. 2010 Mathematics Subject Classification. 47B47, 47L35. 1. Introduction. Let A be an algebra. Recall that a linear ...

  7. Haenamindole, an unusual diketopiperazine derivative from a marine-derived Penicillium sp. KCB12F005.

    Science.gov (United States)

    Kim, Jong Won; Ko, Sung-Kyun; Son, Sangkeun; Shin, Kee-Sun; Ryoo, In-Ja; Hong, Young-Soo; Oh, Hyuncheol; Hwang, Bang Yeon; Hirota, Hiroshi; Takahashi, Shunji; Kim, Bo Yeon; Osada, Hiroyuki; Jang, Jae-Hyuk; Ahn, Jong Seog

    2015-11-15

    During the chemical investigation of marine-derived fungus, an unusual diketopiperazine (DKP) alkaloid, haenamindole (1), was isolated from a culture of the marine-derived fungus Penicillium sp. KCB12F005. The structure of 1, which possesses benzyl-hydroxypiperazindione and phenyl-pyrimidoindole rings system in the molecule, was elucidated by analysis of NMR and MS data. The stereochemistry of 1 was determined by ROESY and advanced Marfey's method. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Performance of small-scale aero-derivative industrial gas turbines derived from helicopter engines

    Directory of Open Access Journals (Sweden)

    Barinyima Nkoi

    2013-12-01

    Full Text Available This paper considers comparative assessment of simple and advanced cycle small-scale aero-derivative industrial gas turbines derived from helicopter engines. More particularly, investigation was made of technical performance of the small-scale aero-derivative engine cycles based on existing and projected cycles for applications in industrial power generation, combined heat and power concept, rotating equipment driving, and/or allied processes. The investigation was done by carrying out preliminary design and performance simulation of a simple cycle (baseline two-spool small-scale aero-derivative turboshaft engine model, and some advanced counterpart aero-derivative configurations. The advanced configurations consist of recuperated and intercooled/recuperated engine cycles of same nominal power rating of 1.567 MW. The baseline model was derived from the conversion of an existing helicopter engine model. In doing so, design point and off-design point performances of the engine models were established. In comparing their performances, it was observed that to a large extent, the advanced engine cycles showed superior performance in terms of thermal efficiency, and specific fuel consumption. In numerical terms, thermal efficiencies of recuperated engine cycle, and intercooled/recuperated engine cycles, over the simple cycle at DP increased by 13.5%, and 14.5% respectively, whereas specific fuel consumption of these cycles over simple cycle at DP decreased by 12.5%, and 13% respectively. This research relied on open access public literature for data.

  9. Superstability for Generalized Module Left Derivations and Generalized Module Derivations on a Banach Module (I

    Directory of Open Access Journals (Sweden)

    Huai-Xin Cao

    2009-01-01

    Full Text Available We discuss the superstability of generalized module left derivations and generalized module derivations on a Banach module. Let 𝒜 be a Banach algebra and X a Banach 𝒜-module, f:X→X and g:𝒜→𝒜. The mappings Δf,g1, Δf,g2, Δf,g3, and Δf,g4 are defined and it is proved that if ∥Δf,g1(x,y,z,w∥ (resp., ∥Δf,g3(x,y,z,w,α,β∥ is dominated by φ(x,y,z,w, then f is a generalized (resp., linear module-𝒜 left derivation and g is a (resp., linear module-X left derivation. It is also shown that if ∥Δf,g2(x,y,z,w∥ (resp., ∥Δf,g4(x,y,z,w,α,β∥ is dominated by φ(x,y,z,w, then f is a generalized (resp., linear module-𝒜 derivation and g is a (resp., linear module-X derivation.

  10. MODERN TRENDS OF DEVELOPMENT OF INTERNATIONAL DERIVATIVES MARKET

    Directory of Open Access Journals (Sweden)

    V. Shelydko

    2014-09-01

    Full Text Available Article is devoted to analysis of structure and peculiarities of development of the international derivatives market. The history of formation of the international derivatives market is investigated. The nature, functions and advantages of use of derivatives, and also their role in the modern international securities market are defined. Classification of financial derivatives is considered. Product lines of financial derivatives are analyzed. The regional structure of the international derivatives market and dynamics of its development are investigated. The comparative characteristic of volumes and structure of exchange and over-the-counter segments of international derivatives market are carried out. Dynamics and structure of international markets of interest-bearing derivatives and currency derivatives are analyzed. The fundamental trends of development of the modern international derivatives market are defined.

  11. ON THE DERIVATIVE OF SMOOTH MEANINGFUL FUNCTIONS

    Directory of Open Access Journals (Sweden)

    Sanjo Zlobec

    2011-02-01

    Full Text Available The derivative of a function f in n variables at a point x* is one of the most important tools in mathematical modelling. If this object exists, it is represented by the row n-tuple f(x* = [∂f/∂xi(x*] called the gradient of f at x*, abbreviated: “the gradient”. The evaluation of f(x* is usually done in two stages, first by calculating the n partials and then their values at x = x*. In this talk we give an alternative approach. We show that one can characterize the gradient without differentiation! The idea is to fix an arbitrary row n-tuple G and answer the following question: What is a necessary and sufficient condition such that G is the gradient of a given f at a given x*? The answer is given after adjusting the quadratic envelope property introduced in [3]. We work with smooth, i.e., continuously differentiable, functions with a Lipschitz derivative on a compact convex set with a non-empty interior. Working with this class of functions is not a serious restriction. In fact, loosely speaking, “almost all” smooth meaningful functions used in modelling of real life situations are expected to have a bounded “acceleration” hence they belong to this class. In particular, the class contains all twice differentiable functions [1]. An important property of the functions from this class is that every f can be represented as the difference of some convex function and a convex quadratic function. This decomposition was used in [3] to characterize the zero derivative points. There we obtained reformulations and augmentations of some well known classic results on optimality such as Fermats extreme value theorem (known from high school and the Lagrange multiplier theorem from calculus [2, 3]. In this talk we extend the results on zero derivative points to characterize the relation G = f(x*, where G is an arbitrary n-tuple. Some special cases: If G = O, we recover the results on zero derivative points. For functions of a single

  12. Usefulness Of Derivative Instruments In Emerging Markets: Turkish Experience

    OpenAIRE

    Cem Saatcioglu; Iskender Karagul; Ara G. Volkan

    2011-01-01

    This article presents an overview of derivative markets, definitions of derivative investment instruments, development of global derivative markets and the applicability of derivative markets in Turkey, given their economic value added to the Turkish economy. Readers will acquire insight into investing in various investment instruments and hedging against risk. Turkish derivative markets will be described, supportive statistical data will be presented, and readers will be introduced to the de...

  13. Biologic rhythms derived from Siberian mammoths' hairs.

    Directory of Open Access Journals (Sweden)

    Mike Spilde

    Full Text Available Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was ∼31 cms/year and ∼16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios, which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.

  14. Studies in higher-derivative gravitation

    International Nuclear Information System (INIS)

    Dutt, S.K.

    1987-01-01

    In this work two formulations of gravitation in which the action includes the second-derivatives of the metric in a non-trivial fashion are investigated. In the first part, the gauge theory of gravitation proposed by Yang in 1974 is investigated. The implications of coupling the pure space equations to matter sources via the action principle proposed by Yang is studied. It is shown that this action principle does not couple to matter sources in a satisfactory fashion. An earlier study by Fairchild along similar lines is critically examined. It is argued that Fairchild's action functional, and his objections to Yang's gauge approach to gravitation, arise from a not very meaningful analogy with the case of a general gauge field. Also, a conjecture originated in that work is refuted. A modification of Yang's action functional is provided which leads to both the Einstein and Yang field-equations. This system is shown to have non-trivial solutions in the presence of matter. An additional advantage is that the unphysical solutions of the pure space equations can be ruled out. It is shown that the joint system of Einstein and Yang field-equations leads to a physically viable cosmological model based on the Robertson-Walker metric, which satisfies both sets of field-equations. In the second part of this work, the Hamiltonian for pure gravity in Einstein's theory is obtained directly from the Hilbert Lagrangian. Since the Lagrangian depends upon the second-derivatives of the metric tensor, first the Hamiltonian formulation for a Lagrangian which may, in general depend upon the Nth-order time derivatives of the dynamical variables is developed

  15. Hydration of urea and alkylated urea derivatives

    Science.gov (United States)

    Kaatze, Udo

    2018-01-01

    Compressibility data and broadband dielectric spectra of aqueous solutions of urea and some of its alkylated derivatives have been evaluated to yield their numbers Nh of hydration water molecules per molecule of solute. Nh values in a broad range of solute concentrations are discussed and are compared to hydration numbers of other relevant molecules and organic ions. Consistent with previous results, it is found that urea differs from other solutes in its unusually small hydration number, corresponding to just one third of the estimated number of nearest neighbor molecules. This remarkable hydration behavior is explained by the large density φH of hydrogen bonding abilities offered by the urea molecule. In terms of currently discussed models of reorientational motions and allied dynamics in water and related associating liquids, the large density φH causes a relaxation time close to that of undisturbed water with most parts of water encircling the solute. Therefore only a small part of disturbed ("hydration") water is left around each urea molecule. Adding alkyl groups to the basic molecule leads to Nh values which, within the series of n-alkylurea derivatives, progressively increase with the number of methyl groups per solute. With n-butylurea, Nh from dielectric spectra, in conformity with many other organic solutes, slightly exceeds the number of nearest neighbors. Compared to such Nh values, hydration numbers from compressibility data are substantially smaller, disclosing incorrect assumptions in the formula commonly used to interpret the experimental compressibilities. Similar to other series of organic solutes, effects of isomerization have been found with alkylated urea derivatives, indicating that factors other than the predominating density φH of hydrogen bond abilities contribute also to the hydration properties.

  16. Warm Inflation with Nonminimal Derivative Coupling

    International Nuclear Information System (INIS)

    Rashidi, N.; Nozari, Kourosh; Shoukrani, M.

    2014-01-01

    We study the effects of the nonminimal derivative coupling on the dissipative dynamics of the warm inflation where the scalar field is nonminimally coupled to gravity via its kinetic term. We present a detailed calculation of the cosmological perturbations in this setup. We use the recent observational data from the joint data set of WMAP9 + BAO + H 0 and also the Planck satellite data to constrain our model parameters for natural and chaotic inflation potentials. We study also the levels of non-Gaussianity in this warm inflation model and we confront the result with recent observational data from the Planck satellite

  17. Nonextensive entropies derived from Gauss' principle

    International Nuclear Information System (INIS)

    Wada, Tatsuaki

    2011-01-01

    Gauss' principle in statistical mechanics is generalized for a q-exponential distribution in nonextensive statistical mechanics. It determines the associated stochastic and statistical nonextensive entropies which satisfy Greene-Callen principle concerning on the equivalence between microcanonical and canonical ensembles. - Highlights: → Nonextensive entropies are derived from Gauss' principle and ensemble equivalence. → Gauss' principle is generalized for a q-exponential distribution. → I have found the condition for satisfying Greene-Callen principle. → The associated statistical q-entropy is found to be normalized Tsallis entropy.

  18. Deriving GENERIC from a Generalized Fluctuation Symmetry

    Science.gov (United States)

    Kraaij, Richard; Lazarescu, Alexandre; Maes, Christian; Peletier, Mark

    2018-02-01

    Much of the structure of macroscopic evolution equations for relaxation to equilibrium can be derived from symmetries in the dynamical fluctuations around the most typical trajectory. For example, detailed balance as expressed in terms of the Lagrangian for the path-space action leads to gradient zero-cost flow. We expose a new such fluctuation symmetry that implies GENERIC, an extension of gradient flow where a Hamiltonian part is added to the dissipative term in such a way as to retain the free energy as Lyapunov function.

  19. Superspace higher derivative terms in two dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Farakos, Fotis [Dipartimento di Fisica “Galileo Galilei”, Università di Padova,Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova,Via Marzolo 8, 35131 Padova (Italy); Kočí, Pavel; Unge, Rikard von [Institute for Theoretical Physics, Masaryk University,611 37 Brno (Czech Republic)

    2017-04-03

    We study (2,2) and (4,4) supersymmetric theories with superspace higher derivatives in two dimensions. A characteristic feature of these models is that they have several different vacua, some of which break supersymmetry. Depending on the vacuum, the equations of motion describe different propagating degrees of freedom. Various examples are presented which illustrate their generic properties. As a by-product we see that these new vacua give a dynamical way of generating non-linear realizations. In particular, our 2D (4,4) example is the dimensional reduction of a 4D N=2 model, and gives a new way for the spontaneous breaking of extended supersymmetry.

  20. Derivation of Batho's correction factor for heterogeneities

    International Nuclear Information System (INIS)

    Lulu, B.A.; Bjaerngard, B.E.

    1982-01-01

    Batho's correction factor for dose in a heterogeneous, layered medium is derived from the tissue--air ratio method (TARM). The reason why the Batho factor is superior to the TARM factor at low energy is ascribed to the fact that it accounts for the distribution of the scatter-generating matter along the centerline. The poor behavior of the Batho factor at high energies is explained as a consequence of the lack of electron equilibrium at appreciable depth below the surface. Key words: Batho factor, heterogeneity, inhomogeneity, tissue--air ratio method

  1. Derivative expansion and renormalisation group flows

    CERN Document Server

    Litim, Daniel F

    2001-01-01

    We study the convergence of the derivative expansion for flow equations. The convergence strongly depends on the choice for the infrared regularisation. Based on the structure of the flow, we explain why optimised regulators lead to better physical predictions. This is applied to O(N)-symmetric real scalar field theories in 3d, where critical exponents are computed for all N. In comparison to the sharp cut-off regulator, an optimised flow improves the leading order result up to 10%. An analogous reasoning is employed for a proper time renormalisation group. We compare our results with those obtained by other methods.

  2. [A new eremophilane derivative from Senecio dianthus].

    Science.gov (United States)

    Han, He-Dong; Hu, Hai-Qing; Li, Yan; Wang, Xiao-Ling

    2013-10-01

    A new eremophilane derivative, 4,5,11-trimethyl-9( 10), 7 ( 11) -eremophiladien-8-keto-12-carboxylic acid-beta-D-glucopyranoside( which named dianthuside A) 1 and four known compounds, 5,7,4'-trihydroxy-flavonone-3-0-beta-D-glucoside (2), quercetin-3-0-beta-D-glucoside(3) ,hyperin(4) and rutin(5) have been isolated from the aerial part of Senecio dianthus. Their structures were elucidated by physicochemical properties and spectroscopic data analysis. Compounds 2, 4 and 5 were isolated from this plant for the first time.

  3. Black holes in higher derivative gravity.

    Science.gov (United States)

    Lü, H; Perkins, A; Pope, C N; Stelle, K S

    2015-05-01

    Extensions of Einstein gravity with higher-order derivative terms arise in string theory and other effective theories, as well as being of interest in their own right. In this Letter we study static black-hole solutions in the example of Einstein gravity with additional quadratic curvature terms. A Lichnerowicz-type theorem simplifies the analysis by establishing that they must have vanishing Ricci scalar curvature. By numerical methods we then demonstrate the existence of further black-hole solutions over and above the Schwarzschild solution. We discuss some of their thermodynamic properties, and show that they obey the first law of thermodynamics.

  4. A microscopic derivation of stochastic differential equations

    International Nuclear Information System (INIS)

    Arimitsu, Toshihico

    1996-01-01

    With the help of the formulation of Non-Equilibrium Thermo Field Dynamics, a unified canonical operator formalism is constructed for the quantum stochastic differential equations. In the course of its construction, it is found that there are at least two formulations, i.e. one is non-hermitian and the other is hermitian. Having settled which framework should be satisfied by the quantum stochastic differential equations, a microscopic derivation is performed for these stochastic differential equations by extending the projector methods. This investigation may open a new field for quantum systems in order to understand the deeper meaning of dissipation

  5. Derivation of an applied nonlinear Schroedinger equation

    Energy Technology Data Exchange (ETDEWEB)

    Pitts, Todd Alan [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Laine, Mark Richard [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Schwarz, Jens [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Rambo, Patrick K. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Karelitz, David B. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

    We derive from first principles a mathematical physics model useful for understanding nonlinear optical propagation (including filamentation). All assumptions necessary for the development are clearly explained. We include the Kerr effect, Raman scattering, and ionization (as well as linear and nonlinear shock, diffraction and dispersion). We explain the phenomenological sub-models and each assumption required to arrive at a complete and consistent theoretical description. The development includes the relationship between shock and ionization and demonstrates why inclusion of Drude model impedance effects alters the nature of the shock operator. Unclassified Unlimited Release

  6. Radioprotective properties of sulpholane amidoalkyl derivatives

    International Nuclear Information System (INIS)

    Izmozherov, N.N.; Girshik, G.V.

    A series of sulpholane derivatives has been studied from the viewpoint of their possible anti-radiation efficiency. The highest activity at experiments in vitro has been manifested by compounds with dimethylamide radicals in a molecule. The estimate of anti-radiation action was provided by testing with the analysis of cytogenetic damages in the cell culture of the Chinese hamster. The compounds studied were introduced into the medium 20-30 min before irradiation, with the dose of 600 rad at the intensity of 27 rad/min. The percentage of aberrant metaphases and the number of chromosomal aberrations of various types decreased more than 2 times

  7. Molecular Recognition Studies on Naphthyridine Derivatives

    Directory of Open Access Journals (Sweden)

    José Carlos Iglesias-Sánchez

    2010-03-01

    Full Text Available The association constants Kb of three hosts I–III designed to have both enhanced hydrogen bonding donor strength and conformational preorganization with biotin analogues 1–5 are reported. 1H-NMR titrations under two different concentration conditions have been employed to determine the association constants Kb. A statistical analysis using a presence absence matrix has been applied to calculate the different contributions. Hydrogen bond interactions make naphthyridine derivatives II and III potent binders and effective receptors for (+-biotin methyl ester (1, due to the complex stabilization by additional hydrogen bonds.

  8. Biochemical activity of fullerenes and related derivatives

    International Nuclear Information System (INIS)

    Huczko, A.; Lange, H.; Calko, E.

    1999-01-01

    An astonishing scientific interest, embodied in over 15000 research articles so far, has been encountered since 1985 when fullerenes were discovered. From new superconductors to a rich electrochemistry and reaction chemistry, fullerene nanostructures continue to excite the scientific world, and new findings continue at record pace. This review presents many examples of the biochemical activities of fullerenes and derivatives, e. g. cytotoxic activity, selective DNA cleavage and antiviral activity against HIV. We also present some results of our testing which show that, despite its chemical and biochemical activity, fullerene matter does not present any health hazard directly related to skin irritation and allergic risks. (author)

  9. Pharmacokinetics of thiamine derivatives especially of benfotiamine.

    Science.gov (United States)

    Loew, D

    1996-02-01

    Pharmacokinetic data of orally administered lipid-soluble thiamine analogues like benfotiamine are reviewed and assessed. It is quite clear that benfotiamine is absorbed much more better than water-soluble thiamine salts: maximum plasma levels of thiamine are about 5 times higher after benfotiamine, the bioavailability is at maximum about 3.6 times as high as that of thiamine hydrochloride and better than other lipophilic thiamine derivates. The physiological activity (alphaETK) increased only after benfotiamine was given. Due to its excellent pharmacokinetic profile benfotiamine should be preferred in treatment of relevant indications.

  10. Superspace higher derivative terms in two dimensions

    International Nuclear Information System (INIS)

    Farakos, Fotis; Kočí, Pavel; Unge, Rikard von

    2017-01-01

    We study (2,2) and (4,4) supersymmetric theories with superspace higher derivatives in two dimensions. A characteristic feature of these models is that they have several different vacua, some of which break supersymmetry. Depending on the vacuum, the equations of motion describe different propagating degrees of freedom. Various examples are presented which illustrate their generic properties. As a by-product we see that these new vacua give a dynamical way of generating non-linear realizations. In particular, our 2D (4,4) example is the dimensional reduction of a 4D N=2 model, and gives a new way for the spontaneous breaking of extended supersymmetry.

  11. Bootstrapping Density-Weighted Average Derivatives

    DEFF Research Database (Denmark)

    Cattaneo, Matias D.; Crump, Richard K.; Jansson, Michael

    Employing the "small bandwidth" asymptotic framework of Cattaneo, Crump, and Jansson (2009), this paper studies the properties of a variety of bootstrap-based inference procedures associated with the kernel-based density-weighted averaged derivative estimator proposed by Powell, Stock, and Stoker...... (1989). In many cases validity of bootstrap-based inference procedures is found to depend crucially on whether the bandwidth sequence satisfies a particular (asymptotic linearity) condition. An exception to this rule occurs for inference procedures involving a studentized estimator employing a "robust...

  12. Valence electronic properties of porphyrin derivatives.

    Science.gov (United States)

    Stenuit, G; Castellarin-Cudia, C; Plekan, O; Feyer, V; Prince, K C; Goldoni, A; Umari, P

    2010-09-28

    We present a combined experimental and theoretical investigation of the valence electronic structure of porphyrin-derived molecules. The valence photoemission spectra of the free-base tetraphenylporphyrin and of the octaethylporphyrin molecule were measured using synchrotron radiation and compared with theoretical spectra calculated using the GW method and the density-functional method within the generalized gradient approximation. Only the GW results could reproduce the experimental data. We found that the contribution to the orbital energies due to electronic correlations has the same linear behavior in both molecules, with larger deviations in the vicinity of the HOMO level. This shows the importance of adequate treatment of electronic correlations in these organic systems.

  13. Selective Oxidation of Biomass-Derived Chemicals

    DEFF Research Database (Denmark)

    Modvig, Amalie Elise

    . These processes should be able to compete with the established processes based on fossil resources. Glycolaldehyde is an often-observed by-product formed from degradation of larger sugars. Due to competing ecological and economical aspects of the well-established processes for extraction and conversion....... The objective of this dissertation was to develop new, alternative and sustainable methods for oxidative catalytic upgrading of biomass-derived compounds, with focus on oxidation of glycolaldehyde and simple alcohols as model substrates for larger sugars. Supported gold nanoparticle were studied...

  14. Boundary layer heights derived from velocity spectra

    Energy Technology Data Exchange (ETDEWEB)

    Hoejstrup, J.; Barthelmie, R.J. [Risoe National Lab., Roskilde (Denmark); Kaellstrand, B. [Univ. of Uppsala, Uppsala (Sweden)

    1997-10-01

    It is a well-known fact that the height of the mixed layer determines the size of the largest and most energetic eddies that can be observed in the unstable boundary layer, and consequently a peak can be observed in the power spectra of the along-wind velocity component at scales comparable to the mixed layer depth. We will now show how the mixed layer depth can be derived from the u-specta and the results will be compared with direct measurements using pibal and tethersonde measurements. (au)

  15. History of myeloid-derived suppressor cells.

    Science.gov (United States)

    Talmadge, James E; Gabrilovich, Dmitry I

    2013-10-01

    Tumour-induced granulocytic hyperplasia is associated with tumour vasculogenesis and escape from immunity via T cell suppression. Initially, these myeloid cells were identified as granulocytes or monocytes; however, recent studies have revealed that this hyperplasia is associated with populations of multipotent progenitor cells that have been identified as myeloid-derived suppressor cells (MDSCs). The study of MDSCs has provided a wealth of information regarding tumour pathobiology, has extended our understanding of neoplastic progression and has modified our approaches to immune adjuvant therapy. In this Timeline article, we discuss the history of MDSCs, their influence on tumour progression and metastasis, and the crosstalk between tumour cells, MDSCs and the host macroenvironment.

  16. Measurements of brain-derived neurotrophic factor

    DEFF Research Database (Denmark)

    Trajkovska, Viktorija; Klein, Anders Bue; Vinberg, Maj

    2007-01-01

    Although numerous studies have dealt with changes in blood brain-derived neurotrophic factor (BDNF), methodological issues about BDNF measurements have only been incompletely resolved. We validated BDNF ELISA with respect to accuracy, reproducibility and the effect of storage and repeated freezing...... (18.6+/-1.3 ng/ml versus 16.5+/-1.4 ng/ml), and showed a right-skewed BDNF concentration distribution. No association between whole blood BDNF concentrations and thrombocyte count, age, or BDNF genotype was found. In conclusion, the BDNF ELISA assay determines whole blood BDNF accurately and with high...

  17. Statistical Analysis of Asian WeatherDerivatives

    OpenAIRE

    Jiao, Yue

    2009-01-01

    Since last decade, weather derivatives have been traded by Chicago Mercantile Exchange(CME) to hedge the weather risk. In addition to HDD,CDD and CAT, which are index written on the temperature in U.S. and Europe, Pacific Rim Index is newly developed and actively traded nowadays. In terms of the great value of research on this new instrument, we study the temperature dynamics of 4 cities in Asia: Tokyo, Osaka, Taipei and Beijing by a continuous-time autoregressive process. We further inferred...

  18. Residues in food derived from animals

    International Nuclear Information System (INIS)

    Grossklaus, D.

    1989-01-01

    The first chapter presents a survey of fundamentals and methods of the detection and analysis of residues in food derived from animals, also referring to the resulting health hazards to man, and to the relevant legal provisions. The subsequent chapters have been written by experts of the Federal Health Office, each dealing with particular types of residues such as those of veterinary drugs, additives to animal feeds, pesticide residues, and with environmental pollutants and the contamination of animal products with radionuclides. (MG) With 35 figs., 61 tabs [de

  19. Quinoxaline derivatives: a patent review (2006--present).

    Science.gov (United States)

    González, Mercedes; Cerecetto, Hugo

    2012-11-01

    Quinoxaline scaffold is included in a large number of therapeutic agents because of its physicochemical properties that make the difference between them and the carbono analogue, naphthalene. This review of patented products presents the quinoxaline heterocycle as part of the structural patent claims from a medicinal chemistry perspective. We centred our discussion in the various drug patent applications of the quinoxaline and its derivatives. The applications are based firstly in the specific enzyme target with very low development in the disease treatment. Only for cancer and antimicrobial agents they were specifically determined but little is mentioned in order to insight in the last development activities.

  20. Survey on the Use of Derivatives in Indonesia

    Directory of Open Access Journals (Sweden)

    I Wayan Nuka Lantara

    2010-09-01

    Full Text Available This paper provides survey evidence on the use of derivatives among firms listed on the Indonesian Stock Exchange. The finding shows that the participation rate in the use of derivatives is 28.8 percent, much lower than those found in developed countries. For the derivatives non-users, insignificant risk exposure is reported as the most important rationale for not using derivatives. Consumer goods industry constitutes the largest proportion of firms using derivatives. The majority of respondents utilize derivatives to hedge against financial risks rather than to speculate. Foreign currency risk and interest rate risk are the most important types of risks faced with by respondents. Using the Chi-square and the Fisher’s exact tests, the result corroborates the size effect hypothesis, where the use of derivatives is more popular among large firms than small firms. A SURVEY ON THE USE OF DERIVATIVES IN INDONESIA Keywords: derivatives; hedging; risk management

  1. SYNTHESIS OF FLAVANONE-6-CARBOXYLIC ACID DERIVATIVES FROM SALICYLIC ACID DERIVATIVE

    Directory of Open Access Journals (Sweden)

    Muhammad Idham Darussalam Mardjan

    2012-02-01

    Full Text Available Synthesis of flavanone-6-carboxylic acid derivatives had been conducted via the route of chalcone. The synthesis was carried out from salicylic acid derivative, i.e. 4-hydroxybenzoic acid, via esterification, Fries rearrangement, Claisen-Schmidt condensation and 1,4-nucleophilic addition reactions. Structure elucidation of products was performed using FT-IR, 1H-NMR, GC-MS and UV-Vis spectrometers. Reaction of 4-hydroxybenzoic acid with methanol catalyzed with sulfuric acid produced methyl 4-hydroxybenzoate in 87% yield. The acid-catalyzed-acetylation of the product using acetic anhydride gave methyl 4-acetoxybenzoate in 75% yield. Furthermore, solvent-free Fries rearrangement of methyl 4-acetoxybenzoate in the presence of AlCl3 produced 3-acetyl-4-hydroxybenzoic acid as the acetophenone derivatives in 67% yield. Then, Claisen-Schmidt condensation of the acetophenone and benzaldehyde derivatives of p-anisaldehyde and veratraldehyde in basic condition gave 2'-hydroxychalcone-5'-carboxylic acid derivatives  in 81 and 71 % yield, respectively. Finally, the ring closure reaction of the chalcone yielded the corresponding flavanone-6-carboxylic acids in 67 and 59% yield, respectively.

  2. Deriving inflation forecasts from government bond prices

    Directory of Open Access Journals (Sweden)

    Kožul Nataša

    2014-01-01

    Full Text Available In financial research and practice, it is widely accepted that nominal interest rates derived from the prices of various financial products of different maturities comprise of corresponding real interest rates and inflation. While extensive research has been conducted on the relationship between these three variables, estimation of their levels is still largely based on the industry surveys and market data. As this information only indicates the current expectations of interest rate and inflation movements over time, a number of caveats should be noted when interpreting such measures. In the US and the UK, where the government bond markets are the largest and most active, a comparative analysis between conventional government bonds and those whose yield is linked to inflation provides a measure of inflation expectations. However, as such analyses implicitly assume that investment in government bonds is virtually risk free, it is questionable whether the derived estimates are of any value in current economic conditions. Moreover, this approach cannot be generalized to other countries, where number of traded products from which any relationship between interest rates and inflation can be determined is limited and different economic conditions prevail. Thus, this paper aims to present an overview of the methodologies used to forecast inflation rates from government bond prices, drawing attention to the key assumptions and limitations of these approaches. The goal is to ascertain their accuracy, and thus their value in determining the real yields of various interest rate-linked products.

  3. Derivative Securities on Romanian Capital Market

    Directory of Open Access Journals (Sweden)

    Ramona Maria GOGONCEA

    2011-12-01

    Full Text Available This study aimed to investigate whether the world wide agreed models of valuation of derivates may be properly applied to the Romanian capital market, obtaining reliable results for decision makers. The most common valuation models take into account market data such as, interest and exchange rates, volatilities and the price of the underlying instrument. The procedures for valuation must clearly define the nature of the market data to be taken into consideration (for example the zero-coupon curve for the valuation of swaps and the independent reference base to be used (Reuters at a given time, bid/offer or mid price, broker. In order to be able to obtain the results, I based my study on a self-developed software which can calculate the price and characteristics for different types of derivatives securities once the primary data are filled in. I compared the results obatined usig the valuation models with the actual prices on the Romanian capital market. I expected that the results obtained to be more accurate as the parameters used in the calculation models properly reflect market data as at that date being as widely as possible.. These assumptions were only supported for certain value orientations. In conclusion, explanations for these results are given and limitations for this study are discussed. Also, suggestions for future research are presented in the final part of the article.

  4. Primer on electricity futures and other derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Stoft, S.; Belden, T.; Goldman, C.; Pickle, S.

    1998-01-01

    Increased competition in bulk power and retail electricity markets is likely to lower electricity prices, but will also result in greater price volatility as the industry moves away from administratively determined, cost-based rates and encourages market-driven prices. Price volatility introduces new risks for generators, consumers, and marketers. Electricity futures and other derivatives can help each of these market participants manage, or hedge, price risks in a competitive electricity market. Futures contracts are legally binding and negotiable contracts that call for the future delivery of a commodity. In most cases, physical delivery does not take place, and the futures contract is closed by buying or selling a futures contract on or near the delivery date. Other electric rate derivatives include options, price swaps, basis swaps, and forward contracts. This report is intended as a primer for public utility commissioners and their staff on futures and other financial instruments used to manage price risks. The report also explores some of the difficult choices facing regulators as they attempt to develop policies in this area.

  5. Platelet-Derived Microvesicles in Cardiovascular Diseases

    Directory of Open Access Journals (Sweden)

    Maria T. K. Zaldivia

    2017-11-01

    Full Text Available Microvesicles (MVs circulating in the blood are small vesicles (100–1,000 nm in diameter derived from membrane blebs of cells such as activated platelets, endothelial cells, and leukocytes. A growing body of evidence now supports the concept that platelet-derived microvesicles (PMVs, the most abundant MVs in the circulation, are important regulators of hemostasis, inflammation, and angiogenesis. Compared with healthy individuals, a large increase of circulating PMVs has been observed, particularly in patients with cardiovascular diseases. As observed in MVs from other parent cells, PMVs exert their biological effects in multiple ways, such as triggering various intercellular signaling cascades and by participating in transcellular communication by the transfer of their “cargo” of cytoplasmic components and surface receptors to other cell types. This review describes our current understanding of the potential role of PMVs in mediating hemostasis, inflammation, and angiogenesis and their consequences on the pathogenesis of cardiovascular diseases, such as atherosclerosis, myocardial infarction, and venous thrombosis. Furthermore, new developments of the therapeutic potential of PMVs for the treatment of cardiovascular diseases will be discussed.

  6. Assessment of satellite derived diffuse attenuation coefficients ...

    Science.gov (United States)

    Optical data collected in coastal waters off South Florida and in the Caribbean Sea between January 2009 and December 2010 were used to evaluate products derived with three bio-optical inversion algorithms applied to MOIDS/Aqua, MODIS/Terra, and SeaWiFS satellite observations. The products included the diffuse attenuation coefficient at 490 nm (Kd_490) and for the visible range (Kd_PAR), and euphotic depth (Zeu, corresponding to 1% of the surface incident photosynthetically available radiation or PAR). Above-water hyperspectral reflectance data collected over optically shallow waters of the Florida Keys between June 1997 and August 2011 were used to help understand algorithm performance over optically shallow waters. The in situ data covered a variety of water types in South Florida and the Caribbean Sea, ranging from deep clear waters, turbid coastal waters, and optically shallow waters (Kd_490 range of ~0.03 – 1.29m-1). An algorithm based on Inherent Optical Properties (IOPs) showed the best performance (RMSD turbidity or shallow bottom contamination. Similar results were obtained when only in situ data were used to evaluate algorithm performance. The excellent agreement between satellite-derived remote sensing reflectance (Rrs) and in situ Rrs suggested that

  7. Waste derived bioeconomy in India: A perspective.

    Science.gov (United States)

    S, Venkata Mohan; P, Chiranjeevi; Dahiya, Shikha; A, Naresh Kumar

    2018-01-25

    Environmental and climatic change issues, population explosion, rapid urbanisation, depletion of fossil reserves, need for energy security, huge waste generation, etc. are some of the inherent issues associated with the fossil based linear economy which need greater attention. In this context, the world is gradually transforming from fossil-based economy to a sustainable circular bio-economy. The biogenic waste which is generated in enormous quanties in India can be considered as potential feedstock for structuring the bio-based economy. This communication depicts the need for developing waste derived bioeconomy in the Indian perspective. Waste is now being perceived as a resource with value and believed to supplement petroleum feedstock to a great extent if properly utilized. The necessity to introduce waste as the core element for the future economic models which also allows sustainable development is discussed. The review also establishes drivers for the bioeconomy and structures the waste derived bioeconomy in a sustainable format to address the futuristic needs, scope and opportunities envisaged in the business and economic realm. The enabling technologies/processes that can be applied for biogenic wastes valorisation are elaborated. Circularizing the economy in a waste biorefinery model for the production of biobased products including bioenergy is discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Primer on electricity futures and other derivatives

    International Nuclear Information System (INIS)

    Stoft, S.; Belden, T.; Goldman, C.; Pickle, S.

    1998-01-01

    Increased competition in bulk power and retail electricity markets is likely to lower electricity prices, but will also result in greater price volatility as the industry moves away from administratively determined, cost-based rates and encourages market-driven prices. Price volatility introduces new risks for generators, consumers, and marketers. Electricity futures and other derivatives can help each of these market participants manage, or hedge, price risks in a competitive electricity market. Futures contracts are legally binding and negotiable contracts that call for the future delivery of a commodity. In most cases, physical delivery does not take place, and the futures contract is closed by buying or selling a futures contract on or near the delivery date. Other electric rate derivatives include options, price swaps, basis swaps, and forward contracts. This report is intended as a primer for public utility commissioners and their staff on futures and other financial instruments used to manage price risks. The report also explores some of the difficult choices facing regulators as they attempt to develop policies in this area

  9. Thermal electron heating rate: a derivation

    International Nuclear Information System (INIS)

    Hoegy, W.R.

    1983-11-01

    The thermal electron heating rate is an important heat source term in the ionospheric electron energy balance equation, representing heating by photoelectrons or by precipitating higher energy electrons. A formula for the thermal electron heating rate is derived from the kinetic equation using the electron-electron collision operator as given by the unified theory of Kihara and Aono. This collision operator includes collective interactions to produce a finite collision operator with an exact Coulomb logarithm term. The derived heating rate O(e) is the sum of three terms, O(e) O(p) + S + O(int), which are respectively: (1) primary electron production term giving the heating from newly created electrons that have not yet suffered collisions with the ambient electrons, (2) a heating term evaluated on the energy surface m(e)/2 E(T) at the transition between Maxwellian and tail electrons at E(T), and (3) the integral term representing heating of Maxwellian electrons by energetic tail electrons at energies ET. Published ionospheric electron temperature studies used only the integral term O(int) with differing lower integration limits. Use of the incomplete heating rate could lead to erroneous conclusions regarding electron heat balance, since O(e) is greater than O(int) by as much as a factor of two

  10. Sorption of uranium by cellulose derivatives

    International Nuclear Information System (INIS)

    Muroi, M.; Imai, S.; Hamaguchi, A.

    1985-01-01

    The sorption behaviour of uranium was investigated by batch and column methods using four cellulose derivatives, two having an amino group and two having an amino group plus a dithiocarboxylate group. All four derivatives showed maximum uranium sorption from pure water in the neutral region or from artificial sea water in the acidic region. In the batch method, quantitative removal of 100 μg of uranium from 50 ml of water at pH 5.0 was achieved by equilibration with 50 mg of any of the four sorbents. The percentage removal under these conditions decreased gradually with increasing concentration of uranium above 100 μg per 50 ml. A similar high percentage removal of uranium was achieved using artificial sea water. In the column method, quantitative removal of 5 μg of uranium from 1l of water at pH 6.7 was achieved with 200 mg of either of the two sorbents. Similar quantitative removal of uranium was achieved from 1l of artificial sea water at pH 5.4 with 500 mg of either of the two sorbents. (author)

  11. Fluoride removal performance of glass derived hydroxyapatite

    International Nuclear Information System (INIS)

    Liang, Wen; Zhan, Lei; Piao, Longhua; Russel, Christian

    2011-01-01

    Research highlights: → Novel sodium calcium borate glass derived hydroxyapatite (G-HAP) is prepared. → Micro-G-HAP adsorbs F - ions in solutions more effectively than commercial nano-HAP. → The adsorption kinetics and isotherms are well fitted by a second order kinetic model and Freundlich isotherm model. -- Abstract: A novel sodium calcium borate glass derived hydroxyapatite (G-HAP) with different ranges of particle size was prepared by immersion sodium calcium borate glass in 0.1 M K 2 HPO 4 solution by the ratio of 50 g L -1 for 7 days. The unique advantage of G-HAP for the adsorption of fluoride ions in solutions was studied. The effects of size and quantity of particles, pH value and adsorption time on adsorption performance were investigated. The maximum adsorption capacity was 17.34 mg g -1 if 5 g L -1 , - in solution more effectively than commercial nano-HAP, which makes potential application of the G-HAP in removing the fluoride ions from wastewater. The adsorption kinetics and isotherms for F - could be well fitted by a second order kinetic model and Freundlich isotherm model respectively, which could be used to describe the adsorption behavior. The mechanism of G-HAP in immobilizing F - from aqueous solutions was investigated by the X-ray diffraction (XRD), infrared spectra (IR) and scanning electron microscopy (SEM).

  12. Chromoionophoric Recognition of Alkylamines by Nitro Derivative

    International Nuclear Information System (INIS)

    Kim, Ju Hee; Hwang, Ah Ran; Choe, Jong In; Chang, Suk Kyu

    2004-01-01

    The molecular design of efficient and selective chromogenic and fluorogenic ionophore systems for the sensing of chemically and biologically important ionic guests has attracted much attention in the past decade. Many of the compounds are based on the well-known molecular framework of crown ethers, calixarenes, and other EDTA type efficient chelating compounds. Among them the calix[4]arenes are particularly attractive for their selective ionophoric properties toward many of interesting organic ammonium guests. Particularly, the calix[4]arene-crown ethers are known to have unique binding properties toward some of alkali, alkaline earth metal ions, and biogenic amines. Many of the chromogenic sensing materials are developed by conjugating molecular framework of calix[4]- arene-crown ethers with suitable signaling functions of azophenols, thiazoles, and indophenols. Quite unexpectedly, however, the ionophoric properties of simple nitro derivative of calix[4]arene-crown ethers were not reported, except for the closely related structure having ester-ether functions in crown moiety, in spite of their synthetically easy availability and expectedly efficient ionophoric properties toward organic amine guests. In this paper, we report the ionophoric properties of dinitro derivative of calix[4]arene-crown-5 ether 1 toward representative alkylammonium ions aiming for the development of efficient and selective chromogenic sensing material for the biologically important organic amine guests. The Ba 2+ -selective chromogenic behavior of 1 over the representative alkali and alkaline earth metal ions has been reported earlier.

  13. A One Line Derivation of EGARCH

    Directory of Open Access Journals (Sweden)

    Michael McAleer

    2014-06-01

    Full Text Available One of the most popular univariate asymmetric conditional volatility models is the exponential GARCH (or EGARCH specification. In addition to asymmetry, which captures the different effects on conditional volatility of positive and negative effects of equal magnitude, EGARCH can also accommodate leverage, which is the negative correlation between returns shocks and subsequent shocks to volatility. However, the statistical properties of the (quasi- maximum likelihood estimator of the EGARCH parameters are not available under general conditions, but rather only for special cases under highly restrictive and unverifiable conditions. It is often argued heuristically that the reason for the lack of general statistical properties arises from the presence in the model of an absolute value of a function of the parameters, which does not permit analytical derivatives, and hence does not permit (quasi- maximum likelihood estimation. It is shown in this paper for the non-leverage case that: (1 the EGARCH model can be derived from a random coefficient complex nonlinear moving average (RCCNMA process; and (2 the reason for the lack of statistical properties of the estimators of EGARCH under general conditions is that the stationarity and invertibility conditions for the RCCNMA process are not known.

  14. Automatic approach to deriving fuzzy slope positions

    Science.gov (United States)

    Zhu, Liang-Jun; Zhu, A.-Xing; Qin, Cheng-Zhi; Liu, Jun-Zhi

    2018-03-01

    Fuzzy characterization of slope positions is important for geographic modeling. Most of the existing fuzzy classification-based methods for fuzzy characterization require extensive user intervention in data preparation and parameter setting, which is tedious and time-consuming. This paper presents an automatic approach to overcoming these limitations in the prototype-based inference method for deriving fuzzy membership value (or similarity) to slope positions. The key contribution is a procedure for finding the typical locations and setting the fuzzy inference parameters for each slope position type. Instead of being determined totally by users in the prototype-based inference method, in the proposed approach the typical locations and fuzzy inference parameters for each slope position type are automatically determined by a rule set based on prior domain knowledge and the frequency distributions of topographic attributes. Furthermore, the preparation of topographic attributes (e.g., slope gradient, curvature, and relative position index) is automated, so the proposed automatic approach has only one necessary input, i.e., the gridded digital elevation model of the study area. All compute-intensive algorithms in the proposed approach were speeded up by parallel computing. Two study cases were provided to demonstrate that this approach can properly, conveniently and quickly derive the fuzzy slope positions.

  15. New arylsparteine derivatives as positive inotropic drugs.

    Science.gov (United States)

    Boido, Vito; Ercoli, Marcella; Tonelli, Michele; Novelli, Federica; Tasso, Bruno; Sparatore, Fabio; Cichero, Elena; Fossa, Paola; Dorigo, Paola; Froldi, Guglielmina

    2017-12-01

    Positive inotropic agents are fundamental in the treatment of heart failure; however, their arrhythmogenic liability and the increased myocardial oxygen demand strongly limit their therapeutic utility. Pursuing our study on cardiovascular activities of lupin alkaloid derivatives, several 2-(4-substituted-phenyl)-2-dehydrosparteines and 2-(4-substituted-phenyl)sparteines were prepared and tested for inotropic and chronotropic activities on isolated guinea pig atria. Four compounds (6b, 6e, 7b, and 7f) exhibited significant inotropism that, at the higher concentrations, was followed by negative inotropism or toxicity. Compound 7e (2-(4-tolyl)sparteine) exhibited a steep dose-depending inotropic activity up to the highest concentration tested (300 µM) with an E max of 116.5 ± 3.4% of basal force, proving less potent but much more active in comparison to the highest concentrations tested of digoxin and milrinone having E max of 87.5 ± 3.1% and 52.2 ± 1.1%, respectively. Finally, docking studies suggested that the relevant sparteine derivatives could target the sigma-1 receptor, whose involvement in cardiac activity is well documented.

  16. Derivative-free and blackbox optimization

    CERN Document Server

    Audet, Charles

    2017-01-01

    This book is designed as a textbook, suitable for self-learning or for teaching an upper-year university course on derivative-free and blackbox optimization.  The book is split into 5 parts and is designed to be modular; any individual part depends only on the material in Part I.  Part I of the book discusses what is meant by Derivative-Free and Blackbox Optimization, provides background material, and early basics while Part II focuses on heuristic methods (Genetic Algorithms and Nelder-Mead).  Part III presents direct search methods (Generalized Pattern Search and Mesh Adaptive Direct Search) and Part IV focuses on model-based methods (Simplex Gradient and Trust Region).  Part V discusses dealing with constraints, using surrogates, and bi-objective optimization. End of chapter exercises are included throughout as well as 15 end of chapter projects and over 40 figures.  Benchmarking techniques are also presented in the appendix.

  17. Antitumor Effect of Burchellin Derivatives Against Neuroblastoma.

    Science.gov (United States)

    Kurita, Masahiro; Takada, Tomomi; Wakabayashi, Noriko; Asami, Satoru; Ono, Shinichi; Uchiyama, Taketo; Suzuki, Takashi

    2018-02-01

    Neuroblastoma is one of the most commonly encountered malignant solid tumors in the pediatric age group. We examined the antitumor effects of five burchellin derivatives against human neuroblastoma cell lines. We evaluated cytotoxicity by the MTT assay for four human neuroblastoma and two normal cell lines. We also performed analysis of the apoptotic induction effect by flow cytometry, and examined the expression levels of apoptosis- and cell growth-related proteins by western blot analysis. We found that one of the burchellin derivatives (compound 4 ) exerted cytotoxicity against the neuroblastoma cell lines. Compound 4 induced caspase-dependent apoptosis via a mitochondrial pathway. The apoptosis mechanisms induced by compound 4 involved caspase-3, -7 and -9 activation and poly (ADP-ribose) polymerase cleavage. In addition, compound 4 induced cell death through inhibition of the cell growth pathway (via extracellular signal-regulated kinase 1 and 2, AKT8 virus oncogene cellular homolog, and signal transducer and activator of transcription 3). Compound 4 exerted cellular cytotoxicity against neuroblastoma cells via induction of caspase-dependent apoptosis, and may offer promise for further development as a useful drug for the treatment of advanced neuroblastoma. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  18. Simple derivation of magnetic space groups

    International Nuclear Information System (INIS)

    Bertaut, E.F.; CEA Centre d'Etudes Nucleaires de Grenoble, 38

    1975-01-01

    The magnetic translation lattices can be described by invariant wave vectors k. Advantages of the wave vector notation over the notations used by Belov et al. and Opechowski et al. are pointed out. In a one-dimensional real representation a space group element (α/tau(1)) has either the character +1 (symmetry element) or -1 (antisymmetry element). Thus the square of any space group operation must have the character +1 in a one-dimensional real representation. This simple ''square criterion'' is used to limit the admissible k-vectors and to derive the family of magnetic space groups, i.e. the set of all possible magnetic space groups, belonging to the same crystallographic space group. In the discussion some useful side results are obtained. Not only the real one-dimensional representations of point groups are connected to real one-dimensional representations of space groups, but a direct connection is shown to exist between one-dimensional complex representations of the point groups 3, 4 and 6 and one-dimensional real representations, belonging to P[001/2]=Psub(2c)(Psub(c))-lattices with screw axes 3 1 , 3 2 , 4 2 , 6 2 and 6 4 . Rules are derived for finding the Belov symbol when the Opechowski-Guccione symbol of the magnetic space group is known and this opportunity is used for correcting errors in the Opechowski-Guccione tables [fr

  19. Effects of titanium dioxide nanoparticles derived from ...

    Science.gov (United States)

    Increased manufacture of TiO2 nano-products has caused concern about the potential toxicity of these products to the environment and in public health. Identification and confirmation of the presence of TiO2 nanoparticles derived from consumer products as opposed to industrial TiO2 NPs warrants examination in exploring the significance of their release and resultant impacts on the environment. To this end we examined the significance of the release of these particles and their toxic effect on the marine diatom algae Thalassiosira pseudonana. Our results indicate that nano-TiO2 sunscreen and toothpaste exhibit more toxicity in comparison to industrial TiO2, and inhibited the growth of the marine diatom Thalassiosira pseudonana. This inhibition was proportional to the exposure time and concentrations of nano-TiO2. Our findings indicate a significant effect, and therefore further research is warranted in evaluation and assessment of the toxicity of modified nano-TiO2 derived from consumer products and their physicochemical properties. Submit to journal Environmental Science and Pollution Research.

  20. Kalman-predictive-proportional-integral-derivative (KPPID)

    International Nuclear Information System (INIS)

    Fluerasu, A.; Sutton, M.

    2004-01-01

    With third generation synchrotron X-ray sources, it is possible to acquire detailed structural information about the system under study with time resolution orders of magnitude faster than was possible a few years ago. These advances have generated many new challenges for changing and controlling the state of the system on very short time scales, in a uniform and controlled manner. For our particular X-ray experiments on crystallization or order-disorder phase transitions in metallic alloys, we need to change the sample temperature by hundreds of degrees as fast as possible while avoiding over or under shooting. To achieve this, we designed and implemented a computer-controlled temperature tracking system which combines standard Proportional-Integral-Derivative (PID) feedback, thermal modeling and finite difference thermal calculations (feedforward), and Kalman filtering of the temperature readings in order to reduce the noise. The resulting Kalman-Predictive-Proportional-Integral-Derivative (KPPID) algorithm allows us to obtain accurate control, to minimize the response time and to avoid over/under shooting, even in systems with inherently noisy temperature readings and time delays. The KPPID temperature controller was successfully implemented at the Advanced Photon Source at Argonne National Laboratories and was used to perform coherent and time-resolved X-ray diffraction experiments.

  1. Synthesis and anticancer evaluation of imidazolinone and benzoxazole derivatives

    Directory of Open Access Journals (Sweden)

    Heba A. El-Hady

    2017-05-01

    Full Text Available A series of imidazolinone and benzoxazole derivatives (3 and 5 have been synthesized by the condensation of oxazolinone derivatives (2a–c with aniline and 2-hydroxyaniline. Acetyl derivatives (4, 6 and 7 were prepared via acetylation of compounds 3 and 5 with acetic anhydride and chloroacetyl chloride. The results revealed that imidazolinone and benzoxazole derivatives are potent against the cancer cell lines MCF-7 and HePG2. In particular, benzoxazole derivatives are more potent than imidazolinone derivatives.

  2. Fractional derivatives. An introduction; Derivate frazionarie. Che cosa sono, a cosa servono

    Energy Technology Data Exchange (ETDEWEB)

    Dattoli, G. [ENEA, Div. Fisica Applicata, Centro Ricerche Frascati, Rome (Italy)

    2001-07-01

    In this item is presented a brief survey of fractional calculus and of the relevant applications. In the work are discussed different points of view of the operation of fractional derivative and present a unifying definition. The role played by fractional derivatives and integrals within the framework of integral transform is analyzed. [Italian] In questo articolo si traccia un profilo del cosidetto calcolo frazionario e delle relative applicazioni a problemi di matematica pura ed applicata. Si discutono varie definizioni dell'operazione di derivata frazionaria, non tutte coincidenti fra loro, e si mostra come sia possibile proporre una definizione univoca che inglobi tutte le altre. Si analizza infine il ruolo giocato dalle derivate e dagli integrali frazionari e, piu' in generale, quello degli operatori differenziali ad esponente frazionario, nell'ambito della teoria delle rappresentazioni integrali.

  3. Mass Spectrometric Characteristics of Prenylated Indole Derivatives from Marine-Derived Penicillium sp. NH-SL.

    Science.gov (United States)

    Ding, Hui; Ding, Wanjing; Ma, Zhongjun

    2017-03-22

    Two prenylated indole alkaloids were isolated from the ethyl acetate extracts of a marine-derived fungus Penicillium sp. NH-SL and one of them exhibited potent cytotoxic activity against mouse hepa 1c1c7 cells. In order to detect other bioactive analogs, we used liquid chromatogram tandem mass spectrometry (LC-MS/MS) to analyze the mass spectrometric characteristics of the isolated compounds as well as the crude extracts. As a result, three other analogs were detected, and their structures were deduced according to the similar fragmentation patterns. This is the first systematic report on the mass spectrometric characteristics of prenylated indole derivatives.

  4. Biologic Rhythms Derived from Siberian Mammoths Hairs

    Energy Technology Data Exchange (ETDEWEB)

    M Spilde; A Lanzirotti; C Qualls; G Phillips; A Ali; L Agenbroad; O Appenzeller

    2011-12-31

    Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was {approx}31 cms/year and {approx}16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.

  5. A conformational study of proline derivatives

    Directory of Open Access Journals (Sweden)

    M.E. Kamwaya

    2002-12-01

    Full Text Available From the study of the structures and molecular conformations of a number of proline derivatives, some conclusions were drawn. The widening effect of angle Cα-C'-N' is caused by steric repulsion between a hydrogen atom at Cα of the preceding prolyl residue with any other at either Cα or Cδ of the pyrrolidine ring cis to it. This effect is influenced by the distance between the said hydrogen atoms: the nearer this distance is, the greater is the steric repulsion and the wider is the angle of steric repulsion. The ratio of the angle of steric repulsion to the distance between Cα and the following Cα (or Cδ cis to it is approximately 40 and 41 for peptides with trans and cis configurations, respectively. The torsion angle ranges for χ1, χ3, χ 4, θ and φ in these derivatives are widened more than usual. The highest vibration, which more often takes place at either the Cβ or Cγ of the pyrrolidine ring, does so not necessarily at the one that is puckered. A Δ&psi -relationship is established, for the determination of α-helixity or collageneity, also in small peptides and amino acids that contain proline. The Δ&psi-relationship is versatile and gives about +180o and –180o for the two categories, respectively. The distance between the carbonyl and hydroxyl (or otherwise terminal end atoms is minimal (2.2 Å and constant, for all peptides. The ratios of the angles at the carbonyl carbons (O'-C'-N' or (O'-C'-O' to this distance is also constant: 56 and 57 for the cis and trans confirgurations, respectively; i.e. a proline O'-C'-N'- (or O'-C'-O'-test, hereinafter called the CT-test, has been established for the determination of cis and trans configurations. It is also established in these proline derivatives, that whereas puckering takes place at Cβ for the CS form, it does so at Cγ for the C2 form.

  6. Artemisinin derivatives for treating severe malaria.

    Science.gov (United States)

    McIntosh, H M; Olliaro, P

    2000-01-01

    Artemisinin derivatives may have advantages over quinoline drugs for treating severe malaria since they are fast acting and effective against quinine resistant malaria parasites. The objective of this review was to assess the effects of artemisinin drugs for severe and complicated falciparum malaria in adults and children. We searched the Cochrane Infectious Diseases Group trials register, Cochrane Controlled Trials Register, Medline, Embase, Science Citation Index, Lilacs, African Index Medicus, conference abstracts and reference lists of articles. We contacted organisations, researchers in the field and drug companies. Randomised and pseudo-randomised trials comparing artemisinin drugs (rectal, intramuscular or intravenous) with standard treatment, or comparisons between artemisinin derivatives in adults or children with severe or complicated falciparum malaria. Eligibility, trial quality assessment and data extraction were done independently by two reviewers. Study authors were contacted for additional information. Twenty three trials are included, allocation concealment was adequate in nine. Sixteen trials compared artemisinin drugs with quinine in 2653 patients. Artemisinin drugs were associated with better survival (mortality odds ratio 0.61, 95% confidence interval 0.46 to 0.82, random effects model). In trials where concealment of allocation was adequate (2261 patients), this was barely statistically significant (odds ratio 0.72, 95% CI 0.54 to 0.96, random effects model). In 1939 patients with cerebral malaria, mortality was also lower with artemisinin drugs overall (odds ratio 0.63, 95% CI 0.44 to 0.88, random effects model). The difference was not significant however when only trials reporting adequate concealment of allocation were analysed (odds ratio 0.78, 95% CI 0.55 to 1.10, random effects model) based on 1607 patients. No difference in neurological sequelae was shown. Compared with quinine, artemisinin drugs showed faster parasite clearance from

  7. Radon-Nikodym derivatives of quantum operations

    International Nuclear Information System (INIS)

    Raginsky, Maxim

    2003-01-01

    Given a completely positive (CP) map T, there is a theorem of the Radon-Nikodym type [W. B. Arveson, Acta Math. 123, 141 (1969); V. P. Belavkin and P. Staszewski, Rep. Math. Phys. 24, 49 (1986)] that completely characterizes all CP maps S such that T-S is also a CP map. This theorem is reviewed, and several alternative formulations are given along the way. We then use the Radon-Nikodym formalism to study the structure of order intervals of quantum operations, as well as a certain one-to-one correspondence between CP maps and positive operators, already fruitfully exploited in many quantum information-theoretic treatments. We also comment on how the Radon-Nikodym theorem can be used to derive norm estimates for differences of CP maps in general, and of quantum operations in particular

  8. Derivatives Trading, Climate Science and Human Rights

    DEFF Research Database (Denmark)

    Haigh, Matthew

    for capital flows associated with climate management. Media communications and decision making theories are used to interpret data drawn from participant observation and interviews with climate scientists, policy makers and institutional investors. Findings - The framework suggests a digital divide between...... the heaviest polluters as contributing to carbon-minimised investment portfolios. Assets owned by privately managed pension funds have remained materially exposed to risks posed by climate change. In public finance, a narrow range of financial instruments centred on derivatives trading has entrenched global...... between human rights, climate change, and the stability of private pensions provision. Originality/value - Provides policy sciences useful assessments of communication media and financial instruments used in climate management. Establishes bases for theoretical and applied communications research...

  9. A Shuttle Derived Vehicle launch system

    Science.gov (United States)

    Tewell, J. R.; Buell, D. N.; Ewing, E. S.

    1982-01-01

    This paper describes a Shuttle Derived Vehicle (SDV) launch system presently being studied for the NASA by Martin Marietta Aerospace which capitalizes on existing Shuttle hardware elements to provide increased accommodations for payload weight, payload volume, or both. The SDV configuration utilizes the existing solid rocket boosters, external tank and the Space Shuttle main engines but replaces the manned orbiter with an unmanned, remotely controlled cargo carrier. This cargo carrier substitution more than doubles the performance capability of the orbiter system and is realistically achievable for minimal cost. The advantages of the SDV are presented in terms of performance and economics. Based on these considerations, it is concluded that an unmanned SDV offers a most attractive complement to the present Space Transportation System.

  10. Chemical Sensors Based on Cyclodextrin Derivatives.

    Science.gov (United States)

    Ogoshi, Tomoki; Harada, Akira

    2008-08-25

    This review focuses on chemical sensors based on cyclodextrin (CD) derivatives. This has been a field of classical interest, and is now of current interest for numerous scientists. First, typical chemical sensors using chromophore appended CDs are mentioned. Various "turn-off" and "turn-on" fluorescent chemical sensors, in which fluorescence intensity was decreased or increased by complexation with guest molecules, respectively, were synthesized. Dye modified CDs and photoactive metal ion-ligand complex appended CDs, metallocyclodextrins, were also applied for chemical sensors. Furthermore, recent novel approaches to chemical sensing systems using supramolecular structures such as CD dimers, trimers and cooperative binding systems of CDs with the other macrocycle [2]rotaxane and supramolecular polymers consisting of CD units are mentioned. New chemical sensors using hybrids of CDs with p-conjugated polymers, peptides, DNA, nanocarbons and nanoparticles are also described in this review.

  11. Crown ether derivatives of EDTA: Pt. 6

    International Nuclear Information System (INIS)

    Liu Zhongqun; Qin Shengying; Chen Shaojin; Tan Lin

    1988-01-01

    EDTA-diaminodibenzo-18-crown-6 (cis- and trans-) condensation polymer is a new compound of crown ether derivatives of EDTA. In this paper the adsorption behaviors of U(IV) and U(VI) on this polymer from chloride solutions and effects of hydrochloric acid concentrations, salting-out agents and organic solvents on distribution coefficient (K d ) of uranium are investigated. Adsorption mechanism of uranyl ion (UO 2 2+ ) on this polymer was studied with IR spectra and by means of the adsorption behaviors of compounds of similar structure. Experimental results show that both polyether section and carboxyl groups in EDTA-diaminodibenzo-18-crown-6 take part in complexation with uranyl ion and synergistic effect appeared

  12. Autocrine Effects of Tumor-Derived Complement

    Directory of Open Access Journals (Sweden)

    Min Soon Cho

    2014-03-01

    Full Text Available We describe a role for the complement system in enhancing cancer growth. Cancer cells secrete complement proteins that stimulate tumor growth upon activation. Complement promotes tumor growth via a direct autocrine effect that is partially independent of tumor-infiltrating cytotoxic T cells. Activated C5aR and C3aR signal through the PI3K/AKT pathway in cancer cells, and silencing the PI3K or AKT gene in cancer cells eliminates the progrowth effects of C5aR and C3aR stimulation. In patients with ovarian or lung cancer, higher tumoral C3 or C5aR mRNA levels were associated with decreased overall survival. These data identify a role for tumor-derived complement proteins in promoting tumor growth, and they therefore have substantial clinical and therapeutic implications.

  13. Vowel quality alternation in Dinka verb derivation

    DEFF Research Database (Denmark)

    Andersen, Torben

    2017-01-01

    In Dinka, a predominantly monosyllabic and highly fusional Western Nilotic language, vowel quality alternation in the root plays a major and systematic role in the morphology of verbs, together with alternations in vowel length, voice quality, and tone. Earlier work has shown that in the inflecti...... modifications. These include a different distribution of the vowel grades and interaction with a shift in voice quality, to breathy voice.......In Dinka, a predominantly monosyllabic and highly fusional Western Nilotic language, vowel quality alternation in the root plays a major and systematic role in the morphology of verbs, together with alternations in vowel length, voice quality, and tone. Earlier work has shown that in the inflection...... of simple, i. e., underived, transitive verbs, the vowel quality alternation conforms to a vowel height gradation system with three vowel grades. The present article shows that this vowel gradation system is also operative in the morphology of derived verbs with a transitive root, but with certain...

  14. Reaction between chloromercurocobaltcarborane and undecaborate anion derivatives

    International Nuclear Information System (INIS)

    Lobanova, I.A.; Khitrova, O.M.; Petrovskij, P.V.; Bregadze, V.I.

    2004-01-01

    Interaction of Cs + C 2 B 9 H 12 - and exo-nido-5,6,10-[Cl(Ph 3 P) 2 RU]-5,6,10-(μ-H) 3 -10-H-7,8-C 2 B 9 H 8 with 9-chloromercurocobaltcarborane derivative - 3-(η 5 -Cp)-9-ClHg-3,1,2-CoC 2 B 9 H 10 (η 5 -Cp = cyclopentadiene) in mixed solvent tetrahydrofuran-water-ethanol at room temperature was studied using the methods of elementary analysis and 1 H, 31 P, 11 B NMR. Asymmetric metallocarborane cluster, in which exo-nido-ruthenacarborane and closo-cobalt- or dicarbo-nido-undecaborate fragments are bound via mercury atom, were prepared [ru

  15. A derivation of the beam equation

    International Nuclear Information System (INIS)

    Duque, Daniel

    2016-01-01

    The Euler–Bernoulli equation describing the deflection of a beam is a vital tool in structural and mechanical engineering. However, its derivation usually entails a number of intermediate steps that may confuse engineering or science students at the beginnig of their undergraduate studies. We explain how this equation may be deduced, beginning with an approximate expression for the energy, from which the forces and finally the equation itself may be obtained. The description is begun at the level of small ‘particles’, and the continuum level is taken later on. However, when a computational solution is sought, the description turns back to the discrete level again. We first consider the easier case of a string under tension, and then focus on the beam. Numerical solutions for several loads are obtained. (paper)

  16. A derivation of the beam equation

    Science.gov (United States)

    Duque, Daniel

    2016-01-01

    The Euler-Bernoulli equation describing the deflection of a beam is a vital tool in structural and mechanical engineering. However, its derivation usually entails a number of intermediate steps that may confuse engineering or science students at the beginnig of their undergraduate studies. We explain how this equation may be deduced, beginning with an approximate expression for the energy, from which the forces and finally the equation itself may be obtained. The description is begun at the level of small ‘particles’, and the continuum level is taken later on. However, when a computational solution is sought, the description turns back to the discrete level again. We first consider the easier case of a string under tension, and then focus on the beam. Numerical solutions for several loads are obtained.

  17. Isocorydine Derivatives and Their Anticancer Activities

    Directory of Open Access Journals (Sweden)

    Mei Zhong

    2014-08-01

    Full Text Available In order to improve the anticancer activity of isocorydine (ICD, ten isocorydine derivatives were prepared through chemical structure modifications, and their in vitro and in vivo activities were experimentally investigated. 8-Amino-isocorydine (8 and 6a,7-dihydrogen-isocorydione (10 could inhibit the growth of human lung (A549, gastric (SGC7901 and liver (HepG2 cancer cell lines in vitro. Isocorydione (2 could inhibit the tumor growth of murine sarcoma S180-bearing mice, and 8-acetamino-isocorydine (11, a pro-drug of 8-amino-isocorydine (8, which is instable in water solution at room temperature, had a good inhibitory effect on murine hepatoma H22-induced tumors. The results suggested that the isocorydine structural modifications at C-8 could significantly improve the biological activity of this alkaloid, indicating its suitability as a lead compound in the development of an effective anticancer agent.

  18. Proteoliposome derived cochleate as novel adjuvant.

    Science.gov (United States)

    Bracho, Gustavo; Lastre, Miriam; del Campo, Judith; Zayas, Caridad; González, Domingo; Gil, Danay; Acevedo, Reinaldo; Taboada, Carlos; Solís, Rosa L; Pérez, Oliver

    2006-04-12

    Cochleate structures (CS) consist in a highly stable lipid structures that have been reported to be a good antigen delivery system. The incorporation of pathogen associated molecular pattern (PAMP) from bacterial membranes into CS became in a promising approach to develop adjuvants, particularly mucosal adjuvants. Therefore, we prepare CS from proteoliposome (PL) obtained from Neisseria meningitidis B (PLCS) and evaluated it for its capability to stimulate the immune system as well as the adjuvant activity. The ability of PLCS to induce Thl polarization was also explored. The results and the easy capability for new antigen incorporation on CS support its use as adjuvant for immunization with a large variety of pathogen derived antigens and different routes of immunization.

  19. Current-induced forces: a simple derivation

    International Nuclear Information System (INIS)

    Todorov, Tchavdar N; Dundas, Daniel; Lü, Jing-Tao; Brandbyge, Mads; Hedegård, Per

    2014-01-01

    We revisit the problem of forces on atoms under current in nanoscale conductors. We derive and discuss the five principal kinds of force under steady-state conditions from a simple standpoint that—with the help of background literature—should be accessible to physics undergraduates. The discussion aims at combining methodology with an emphasis on the underlying physics through examples. We discuss and compare two forces present only under current—the non-conservative electron wind force and a Lorentz-like velocity-dependent force. It is shown that in metallic nanowires both display significant features at the wire surface, making it a candidate for the nucleation of current-driven structural transformations and failure. Finally we discuss the problem of force noise and the limitations of Ehrenfest dynamics. (paper)

  20. Higher derivative super Yang-Mills theories

    International Nuclear Information System (INIS)

    Bergshoeff, E.; Rakowski, M.; Sezgin, E.

    1986-11-01

    The most general higher derivative Yang-Mills actions of the type (F 2 +α2F 4 ) which are globally supersymmetric up to order α 2 in six and ten dimensional spacetimes are given. The F 4 -terms turn out to occur in the combination α 2 (tr F 4 - 1/4(tr F 2 ) 2 ), where the trace is over the Lorentz indices. This result agrees with the low energy limit of the open superstring in ten dimensions, where α is the string tension. Surprisingly, the transformation rules of the Yang-Mills multiplet receive order α 2 corrections even in the off-shell formulation. For the case of Abelian Yang-Mills group, the action is expressed in Born-Infeld form with a metric generically given by (1+α 2 F 2 +...). (author)